A 3D gravity and thermal model for the Barents Sea and Kara Sea
NASA Astrophysics Data System (ADS)
Klitzke, Peter; Sippel, Judith; Faleide, Jan Inge; Scheck-Wenderoth, Magdalena
2016-08-01
In the frame of this study, we investigate the lithosphere-scale 3D physical state of the Barents Sea and Kara Sea region. Therefore, we test an existing 3D structural model against the gravitational field by considering the heterogeneous upper mantle to further assess the structural and density configuration of the continental crystalline crust. The resulting 3D density configuration of the crust is discussed in terms of its relationships with the spatial distribution of tectonically different domains. In addition, it provides the base for a lithology-controlled parameterisation of the crust with thermal properties to calculate the 3D conductive thermal field. The deeper thermal field is controlled by the depth configuration of the lithosphere-asthenosphere boundary. Accordingly, deeper isotherms such as the 450 °C isotherm deepen from below the rifted SW Barents Sea towards the intracratonic basins of the eastern Barents Sea and Kara Sea, indicating an increase of the lithospheric strength in the same direction. Temperature measurements of the upper 800 m below the SW Barents Sea reveal an increased thermal gradient which cannot be reproduced by a steady-state 3D conductive model alone. Beside fault-induced fluid flow to be active there, an alternative scenario could involve a phase of subsidence long enough to increase the temperature of the upper 800 m, followed by an uplift and erosion phase that prevented the positive thermal anomaly to propagate towards larger depths. The final lithosphere-scale 3D model is the first to integrate the geological, density and thermal configuration of the entire Barents Sea and Kara Sea region and hence provides an ideal base for future thermomechanical studies addressing, for instance, questions on the present-day, past and future relationships between lithospheric strength and deformation.
Thermal analysis modeling and simulation of spent nuclear fuel canister using CFDS-FLOW3D
Lee, S.Y.
1995-04-01
The computational fluid dynamics (CFD) code CFDS-FLOW3D (version 3.3) has been utilized to model a three-dimensional thermal analysis of the spent nuclear fuel dry storage mockup test. The Experimental Thermal-Fluids (ETF) group obtained experimental data to benchmark computer codes for verifying the dry storage of aluminum-clad spent nu clear fuel. This report provides CFDS-FLOW3D detailed predictions and benchmark, against the test data. Close comparison of the computational results with the experimental data provide verification that the code can be used to predict reasonably accurate convective flow and thermal behavior of a typical foreign research reactor fuel, such as the Material and Testing Reactor (MTR) design tested, while stored in a dry storage facility.
3D thermal modeling of TRISO fuel coupled with neutronic simulation
Hu, Jianwei; Uddin, Rizwan
2010-01-01
The Very High Temperature Gas Reactor (VHTR) is widely considered as one of the top candidates identified in the Next Generation Nuclear Power-plant (NGNP) Technology Roadmap under the U.S . Depanment of Energy's Generation IV program. TRlSO particle is a common element among different VHTR designs and its performance is critical to the safety and reliability of the whole reactor. A TRISO particle experiences complex thermo-mechanical changes during reactor operation in high temperature and high burnup conditions. TRISO fuel performance analysis requires evaluation of these changes on micro scale. Since most of these changes are temperature dependent, 3D thermal modeling of TRISO fuel is a crucial step of the whole analysis package. In this paper, a 3D numerical thermal model was developed to calculate temperature distribution inside TRISO and pebble under different scenarios. 3D simulation is required because pebbles or TRISOs are always subjected to asymmetric thermal conditions since they are randomly packed together. The numerical model was developed using finite difference method and it was benchmarked against ID analytical results and also results reported from literature. Monte-Carlo models were set up to calculate radial power density profile. Complex convective boundary condition was applied on the pebble outer surface. Three reactors were simulated using this model to calculate temperature distribution under different power levels. Two asymmetric boundary conditions were applied to the pebble to test the 3D capabilities. A gas bubble was hypothesized inside the TRISO kernel and 3D simulation was also carried out under this scenario. Intuition-coherent results were obtained and reported in this paper.
Modeling thermally driven energetic response of high explosives in ALE3D
Aro, C.; McCallen, R.C.; Neely, R.; Nichols, A.L. III; Sharp, R.
1998-10-01
The authors have improved their ability to model the response of energetic materials to thermal stimuli and the processes involved in the energetic response. Traditionally, the analyses of energetic materials have involved coupled thermal transport/chemical reaction codes. This provides only a reasonable estimate of the time and location of ensuing rapid reaction. To predict the violence of the reaction, the mechanical motion must be included in the wide range of time scales associated with the thermal hazard. The ALE3D code has been modified to assess the hazards associated with heating energetic materials in weapons by coupling to thermal transport model and chemistry models. They have developed an implicit time step option to efficiently and accurately compute the hours of heating to reaction of the energetic material. Since, on these longer time scales materials can be expected to have significant motion, it is even more important to provide high-order advection for all components, including the chemical species. They show two examples of coupled thermal/mechanical/chemical models of energetic materials in thermal environments.
NASA Astrophysics Data System (ADS)
Wada, I.; Wang, K.; He, J.
2013-12-01
In this study, we revisit the effects of along-strike variation in slab geometry and oblique subduction on subduction zone thermal structures. Along-strike variations in slab dip cause changes in the descending rate of the slab and generate trench-parallel pressure gradients that drive trench-parallel mantle flow (e.g., Kneller and van Keken, 2007). Oblique subduction also drives trench-parallel mantle flow. In this study, we use a finite element code PGCtherm3D and examine a range of generic subduction geometries and parameters to investigate the effects of the above two factors. This exercise is part of foundational work towards developing detailed 3-D thermal models for NE Japan, Nankai, and Cascadia to better constrain their 3-D thermal structures and to understand the role of temperature in controlling metamorphic, seismogenic, and volcanic processes. The 3-D geometry of the subducting slabs in the forearc and arc regions are well delineated at these three subduction zones. Further, relatively large compilations of surface heat flow data at these subduction zones make them excellent candidates for this study. At NE Japan, a megathrust earthquake occurred on March 11, 2011; at Nankai and Cascadia, there has been a great effort to constrain the scale of the next subduction thrust earthquake for the purpose of disaster prevention. Temperature influences the slip behavior of subduction faults by (1) affecting the rheology of the interface material and (2) controlling dehydration reactions, which can lead to elevated pore fluid pressure. Beyond the depths of subduction thrust earthquakes, the thermal structure is affected strongly by the pattern of mantle wedge flow. This flow is driven by viscous coupling between the subducting slab and the overriding mantle, and it brings in hot flowing mantle into the wedge. The trench-ward (up-dip) extent of the slab-mantle coupling is thus a key factor that controls the thermal structure. Slab-mantle decoupling at shallow
NASA Astrophysics Data System (ADS)
Fauchez, Thomas; Davis, Anthony B.; Cornet, Céline; Szczap, Fredéric; Platnick, Steven; Dubuisson, Philippe; Thieuleux, François
2017-01-01
We investigate the impact of cirrus cloud heterogeneity on the direct emission by cloud or surface and on the scattering by ice particles in the thermal infrared (TIR). Realistic 3-D cirri are modeled with the 3DCLOUD code, and top-of-atmosphere radiances are simulated by the 3-D Monte Carlo radiative transfer (RT) algorithm 3DMCPOL for two (8.65 μm and 12.05 μm) channels of the Imaging Infrared Radiometer on CALIPSO. At nadir, comparisons of 1-D and 3-D RT show that 3-D radiances are larger than their 1-D counterparts for direct emission but smaller for scattered radiation. For our cirrus cases, 99% of the 3-D total radiance is computed by the third scattering order, which corresponds to 90% of the total computational effort, but larger optical thicknesses need more scattering orders. To radically accelerate the 3-D RT computations (using only few percent of 3-D RT time with a Monte Carlo code), even in the presence of large optical depths, we develop a hybrid model based on exact 3-D direct emission, the first scattering order from 1-D in each homogenized column, and an empirical adjustment linearly dependent on the optical thickness to account for higher scattering orders. Good agreement is found between the hybrid model and the exact 3-D radiances for two very different cirrus models without changing the empirical parameters. We anticipate that a future deterministic implementation of the hybrid model will be fast enough to process multiangle thermal imagery in a practical tomographic reconstruction of 3-D cirrus fields.
NASA Technical Reports Server (NTRS)
Fauchez, Thomas; Davis, Anthony B.; Cornet, Celine; Szczap, Frederic; Platnick, Steven; Dubuisson, Philippe; Thieuleux, Francois
2017-01-01
We investigate the impact of cirrus cloud heterogeneity on the direct emission by cloud or surface and on the scattering by ice particles in the thermal infrared (TIR). Realistic 3-D cirri are modeled with the 3DCLOUD code, and top-of-atmosphere radiances are simulated by the 3-D Monte Carlo radiative transfer (RT) algorithm 3DMCPOL for two (8.65 micrometers and 12.05 micrometers) channels of the Imaging Infrared Radiometer on CALIPSO. At nadir, comparisons of 1-D and 3-D RT show that 3-D radiances are larger than their 1-D counterparts for direct emission but smaller for scattered radiation. For our cirrus cases, 99% of the 3-D total radiance is computed by the third scattering order, which corresponds to 90% of the total computational effort, but larger optical thicknesses need more scattering orders. To radically accelerate the 3-D RT computations (using only few percent of 3-D RT time with a Monte Carlo code), even in the presence of large optical depths, we develop a hybrid model based on exact 3-D direct emission, the first scattering order from 1-D in each homogenized column, and an empirical adjustment linearly dependent on the optical thickness to account for higher scattering orders. Good agreement is found between the hybrid model and the exact 3-D radiances for two very different cirrus models without changing the empirical parameters. We anticipate that a future deterministic implementation of the hybrid model will be fast enough to process multiangle thermal imagery in a practical tomographic reconstruction of 3-D cirrus fields.
Pannala, S; D'Azevedo, E; Zacharia, T
2002-02-26
The goal of the radiation modeling effort was to develop and implement a radiation algorithm that is fast and accurate for the underhood environment. As part of this CRADA, a net-radiation model was chosen to simulate radiative heat transfer in an underhood of a car. The assumptions (diffuse-gray and uniform radiative properties in each element) reduce the problem tremendously and all the view factors for radiation thermal calculations can be calculated once and for all at the beginning of the simulation. The cost for online integration of heat exchanges due to radiation is found to be less than 15% of the baseline CHAD code and thus very manageable. The off-line view factor calculation is constructed to be very modular and has been completely integrated to read CHAD grid files and the output from this code can be read into the latest version of CHAD. Further integration has to be performed to accomplish the same with STAR-CD. The main outcome of this effort is to obtain a highly scalable and portable simulation capability to model view factors for underhood environment (for e.g. a view factor calculation which took 14 hours on a single processor only took 14 minutes on 64 processors). The code has also been validated using a simple test case where analytical solutions are available. This simulation capability gives underhood designers in the automotive companies the ability to account for thermal radiation - which usually is critical in the underhood environment and also turns out to be one of the most computationally expensive components of underhood simulations. This report starts off with the original work plan as elucidated in the proposal in section B. This is followed by Technical work plan to accomplish the goals of the project in section C. In section D, background to the current work is provided with references to the previous efforts this project leverages on. The results are discussed in section 1E. This report ends with conclusions and future scope of
3D thermal history and maturity modelling of the Levant Basin and Margin
NASA Astrophysics Data System (ADS)
Daher, Samer Bou; Ducros, Mathieu; Michel, Pauline; Nader, Fadi H.; Littke, Ralf
2015-04-01
The gas discoveries recorded in the Levant Basin in the last decade have redirected the industrial and academic communities' interest to this frontier basin and its surroundings. The reported gas in Miocene reservoirs has been assumed to be derived from biogenic sources, although little data has been published so far. The thickness of the sedimentary column and the presence of direct hydrocarbon indicators (DHI) observed in the seismic data suggest the presence of promising prospective thermogenic petroleum systems in deeper intervals in the Levant Basin and along its Margin. In this study we present a large scale 3D thermal history and maturity model of the Levant Basin and Margin, integrating all available calibration data, source rock information collected from onshore Lebanon, and published data. In the first part we will present the main input and assumptions that were made in terms of thicknesses, lithologies, and boundary conditions. In the second part we will discuss the analysed source rocks, their petroleum generation potential and their kinetics. In the third part we will present modelling results including depth maps for key isotherms in addition to transformation ratio and vitrinite reflectance maps for proven and speculative source rocks at different time steps. This will provide a comprehensive assessment of the potential thermogenic petroleum systems in the study area, and allow us to illustrate and discuss the differences between the basinal, marginal, and onshore part of the study area as well as the potential of the northern vis a vis the southern offshore Levant Basin. This model will also allow us to analyse the sensitivity of the system to the various poorly constrained parameters in frontier basins (e.g. crustal thickness, rifting phases, lithologies) and thus identify the most critical data to be collected for future exploration and de-risking strategies.
Development of a 3-D Tree Thermal Response Model for Energy Budget and Scene Simulation Studies.
1991-03-15
from a leaf occurs as a process of water vapor dif- fusion from the saturated inner cells through the leaf stomata and across the leaf boundary layer...trees is being developed to understand the thermal properties of trees. The model is being developed for leafed (deciduous) and leafless conditions...thermal response model for individual trees. The model can be used for leafed and leafless trees. The thermal balance for woody material is
A 3-D thermal regime model suitable for cold accumulation zones of polythermal mountain glaciers
NASA Astrophysics Data System (ADS)
Gilbert, A.; Gagliardini, O.; Vincent, C.; Wagnon, P.
2014-09-01
Analysis of the thermal and mechanical response of high altitude glaciers to climate change is crucial to assess future glacier hazards associated with thermal regime changes. This paper presents a new fully thermo-mechanically coupled transient thermal regime model including enthalpy transport, firn densification, full-Stokes porous flow, free surface evolution, strain heating, surface meltwater percolation, and refreezing. The model is forced by daily air temperature data and can therefore be used to perform prognostic simulations for different future climate scenarios. The set of equations is solved using the finite element ice sheet/ice flow model Elmer/Ice. This model is applied to the Col du Dôme glacier (Mont Blanc area, 4250 m a.s.l., France) where a comprehensive data set is available. The results show that the model is capable of reproducing observed density and velocity fields as well as borehole temperature evolution. The strong spatial variability of englacial temperature change observed at Col du Dôme is well reproduced. This spatial variability is mainly a result of the variability of the slope aspect of the glacier surface and snow accumulation. Results support the use of this model to study the influence of climate change on cold accumulation zones, in particular to estimate where and under what conditions glaciers will become temperate in the future.
NASA Astrophysics Data System (ADS)
Sippel, Judith; Meeßen, Christian; Cacace, Mauro; Mechie, James; Fishwick, Stewart; Heine, Christian; Scheck-Wenderoth, Magdalena; Strecker, Manfred R.
2017-01-01
We present three-dimensional (3-D) models that describe the present-day thermal and rheological state of the lithosphere of the greater Kenya rift region aiming at a better understanding of the rift evolution, with a particular focus on plume-lithosphere interactions. The key methodology applied is the 3-D integration of diverse geological and geophysical observations using gravity modelling. Accordingly, the resulting lithospheric-scale 3-D density model is consistent with (i) reviewed descriptions of lithological variations in the sedimentary and volcanic cover, (ii) known trends in crust and mantle seismic velocities as revealed by seismic and seismological data and (iii) the observed gravity field. This data-based model is the first to image a 3-D density configuration of the crystalline crust for the entire region of Kenya and northern Tanzania. An upper and a basal crustal layer are differentiated, each composed of several domains of different average densities. We interpret these domains to trace back to the Precambrian terrane amalgamation associated with the East African Orogeny and to magmatic processes during Mesozoic and Cenozoic rifting phases. In combination with seismic velocities, the densities of these crustal domains indicate compositional differences. The derived lithological trends have been used to parameterise steady-state thermal and rheological models. These models indicate that crustal and mantle temperatures decrease from the Kenya rift in the west to eastern Kenya, while the integrated strength of the lithosphere increases. Thereby, the detailed strength configuration appears strongly controlled by the complex inherited crustal structure, which may have been decisive for the onset, localisation and propagation of rifting.
Simulating HFIR Core Thermal Hydraulics Using 3D-2D Model Coupling
Travis, Adam R; Freels, James D; Ekici, Kivanc
2013-01-01
A model utilizing interdimensional variable coupling is presented for simulating the thermal hydraulic interactions of the High Flux Isotope Reactor (HFIR) core at Oak Ridge National Laboratory (ORNL). The model s domain consists of a single, explicitly represented three-dimensional fuel plate and a simplified two-dimensional coolant channel slice. In simplifying the coolant channel, and thus the number of mesh points in which the Navier-Stokes equations must be solved, the computational cost and solution time are both greatly reduced. In order for the reduced-dimension coolant channel to interact with the explicitly represented fuel plate, however, interdimensional variable coupling must be enacted along all shared boundaries. The primary focus of this paper is in detailing the collection, storage, passage, and application of variables across this interdimensional interface. Comparisons are made showing the general speed-up associated with this simplified coupled model.
Processes of Equatorial Thermal Structure: An Analysis of Galileo Temperature Profile with 3-D Model
NASA Technical Reports Server (NTRS)
Majeed, T.; Waite, J. H., Jr.; Bougher, S. W.; Gladstone, G. R.
2005-01-01
The Jupiter Thermosphere General Circulation Model (JTGCM) calculates the global dynamical structure of Jupiter's thermosphere self-consistently with its global thermal structure and composition. The main heat source that drives the thermospheric flow is high-latitude Joule heating. A secondary source of heating is the auroral process of particle precipitation. Global simulations of Jovian thermospheric dynamics indicate strong neutral outflows from the auroral ovals with velocities up to approximately 2 kilometers per second and subsequent convergence and downwelling at the Jovian equator. Such circulation is shown to be an important process for transporting significant amounts of auroral energy to equatorial latitudes and for regulating the global heat budget in a manner consistent with the high thermospheric temperatures observed by the Galileo probe. Adiabatic compression of the neutral atmosphere resulting from downward motion is an important source of equatorial heating (less than 0.06 microbar). The adiabatic heating continues to dominate between 0.06 and 0.2 microbar, but with an addition of comparable heating due to horizontal advection induced by the meridional flow. Thermal conduction plays an important role in transporting heat down to lower altitudes (greater than 0.2microbar) where it is balanced by the cooling associated with the wind transport processes. Interestingly, we find that radiative cooling caused by H3(+), CH4, and C2H2 emissions does not play a significant role in interpreting the Galileo temperature profile.
A 3-D mathematical model to identify organ-specific risks in rats during thermal stress.
Rakesh, Vineet; Stallings, Jonathan D; Helwig, Bryan G; Leon, Lisa R; Jackson, David A; Reifman, Jaques
2013-12-01
Early prediction of the adverse outcomes associated with heat stress is critical for effective management and mitigation of injury, which may sometimes lead to extreme undesirable clinical conditions, such as multiorgan dysfunction syndrome and death. Here, we developed a computational model to predict the spatiotemporal temperature distribution in a rat exposed to heat stress in an attempt to understand the correlation between heat load and differential organ dysfunction. The model includes a three-dimensional representation of the rat anatomy obtained from medical imaging and incorporates the key mechanisms of heat transfer during thermoregulation. We formulated a novel approach to estimate blood temperature by accounting for blood mixing from the different organs and to estimate the effects of the circadian rhythm in body temperature by considering day-night variations in metabolic heat generation and blood perfusion. We validated the model using in vivo core temperature measurements in control and heat-stressed rats and other published experimental data. The model predictions were within 1 SD of the measured data. The liver demonstrated the greatest susceptibility to heat stress, with the maximum temperature reaching 2°C higher than the measured core temperature and 95% of its volume exceeding the targeted experimental core temperature. Other organs also attained temperatures greater than the core temperature, illustrating the need to monitor multiple organs during heat stress. The model facilitates the identification of organ-specific risks during heat stress and has the potential to aid in the development of improved clinical strategies for thermal-injury prevention and management.
A 3-D Mathematical Model to Identify Organ-Specific Risks in Rats During Thermal Stress
2013-01-01
organs. Heat is lost by convection, radiation, and evaporation of sweat or saliva (in animals that do not have sweat glands) from the skin surface at...vasodilate to accommodate blood redis- tributed from the core to the body surface by the cardiovascular system (6). The increases in skin blood flow and...heat transfer by cardiovascular blood flow and other mechanisms, such as thermal conduction, thermal responses in the various organs are interdependent
NASA Astrophysics Data System (ADS)
Liang, Guozhou; Zhang, Yiming; Han, Qi; Liu, Zhaoping; Jiang, Zhen; Tian, Shuang
2017-02-01
The safety is one of the persisting concerns related with Lithium-ion (Li-ion) batteries, among which the internal short-circuit is the most dangerous abusive situation and has always been the root cause for several catastrophic accidents in recent years. In this work, a 3D-layered electrochemical-thermal coupled model is employed to investigate the nail-penetration process in a Li-ion cell. The model is based on multilayer construction of a cell, and an effective strategy to evaluate the short-circuit area equivalent resistance (i.e. the equivalent resistance of short-circuit area that is caused by nail-penetration) during the penetration process is proposed. The developed model is proved to have capability of estimating the thermal runaway time, as well as the temperature distribution during nail-penetration process. It is also found that the active material loss during the nail-penetration process can be reconstructed by utilizing the developed model, which could provide understandings about the side reactions inside the cell during the nail-penetration process. The present study provides some insights about the nail-penetration process, and can be treated as a useful tool that helps the design of Li-ion cells for improving safety.
NASA Astrophysics Data System (ADS)
Barbera, E.; Orlando, S.; Peres, G.
2017-04-01
Context. Intermediate polar cataclysmic variables (IPCV) contain a magnetic, rotating white dwarf surrounded by a magnetically truncated accretion disk. To explain their strong flickering X-ray emission, accretion has been successfully taken into account. Nevertheless, observations suggest that accretion phenomena might not be the only process behind it. An intense flaring activity occurring on the surface of the disk may generate a corona, contribute to the thermal X-ray emission, and influence the system stability. Aims: Our purposes are: investigating the formation of an extended corona above the accretion disk, due to an intense flaring activity occurring on the disk surface; studying the effects of flares on the disk and stellar magnetosphere; assessing its contribution to the observed thermal X-ray flux. Methods: We have developed a 3D magnetohydrodynamic (MHD) model of a IPCV system. The model takes into account gravity, disk viscosity, thermal conduction, radiative losses, and coronal flare heating through heat injection at randomly chosen locations on the disk surface. To perform a parameter space exploration, several system conditions have been considered, with different magnetic field intensity and disk density values. From the results of the evolution of the model, we have synthesized the thermal X-ray emission. Results: The simulations show the formation of an extended corona, linking disk and star. The flaring activity is capable of strongly influencing the disk configuration and possibly its stability, effectively deforming the magnetic field lines. Hot plasma evaporation phenomena occur in the layer immediately above the disk. The flaring activity gives rise to a thermal X-ray emission in both the [ 0.1-2.0 ] keV and the [ 2.0-10 ] keV X-ray bands. Conclusions: An intense coronal activity occurring on the disk surface of an IPCV can affect the structure of the disk depending noticeably on the density of the disk and the magnetic field of the central
Lee, K. J.; Kim, G. H.; Smith, K.
2010-10-14
In many commercial cells, long tabs at both cell sides, leading to uniform potentials along the spiral direction of wound jelly rolls, are rarely seen because of their high manufacturing cost. More often, several metal strips are welded at discrete locations along both current collector foils. With this design, the difference of electrical potentials is easily built up along current collectors in the spiral direction. Hence, the design features of the tabs, such as number, location and size, can be crucial factors for spiral-shaped battery cells. This paper presents a Li-ion battery cell model having a 3-dimensional spiral mesh involving a wound jellyroll structure. Further results and analysis will be given regarding impacts of tab location, number, and size.
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…
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.
3D Multifunctional Ablative Thermal Protection System
NASA Technical Reports Server (NTRS)
Feldman, Jay; Venkatapathy, Ethiraj; Wilkinson, Curt; Mercer, Ken
2015-01-01
NASA is developing the Orion spacecraft to carry astronauts farther into the solar system than ever before, with human exploration of Mars as its ultimate goal. One of the technologies required to enable this advanced, Apollo-shaped capsule is a 3-dimensional quartz fiber composite for the vehicle's compression pad. During its mission, the compression pad serves first as a structural component and later as an ablative heat shield, partially consumed on Earth re-entry. This presentation will summarize the development of a new 3D quartz cyanate ester composite material, 3-Dimensional Multifunctional Ablative Thermal Protection System (3D-MAT), designed to meet the mission requirements for the Orion compression pad. Manufacturing development, aerothermal (arc-jet) testing, structural performance, and the overall status of material development for the 2018 EM-1 flight test will be discussed.
Dynamics of 3D isolated thermal filaments
NASA Astrophysics Data System (ADS)
Walkden, N. R.; Easy, L.; Militello, F.; Omotani, J. T.
2016-11-01
Simulations have been carried out to establish how electron thermal physics, introduced in the form of a dynamic electron temperature, affects isolated filament motion and dynamics in 3D. It is found that thermal effects impact filament motion in two major ways when the pressure perturbation within the filament is supported primarily through a temperature increase as opposed to density: they lead to a strong increase in filament propagation in the bi-normal direction and a significant decrease in net radial propagation. Both effects arise from the temperature dependence of the sheath current which leads to a non-uniform floating potential, with the latter effect supplemented by faster pressure loss. The reduction in radial velocity can only occur when the filament cross-section loses angular symmetry. The behaviour is observed across different filament sizes and suggests that filaments with much larger temperature perturbations than density perturbations are more strongly confined to the near SOL region.
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.
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.
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,…
NASA Astrophysics Data System (ADS)
Titarenko, S.; McCaig, A. M.
2014-12-01
A perennial problem in near-ridge hydrothermal circulation is that the only directly measurable data to test models is often vent fluid temperature. Surface heat flow measurements may be available but without the underlying thermal structure it is not known if they are transient and affected by local hydrothermal flow, or conductive. The Atlantis Massif oceanic core complex at 30 °N on the mid-Atlantic Ridge, offers a unique opportunity to better constrain hydrothermal circulation models. The temperature profile in gabbroic rocks of IODP Hole 1309D was measured in IODPExpedition 340T, and found to be near-conductive, but with a slight inflexion at ~750 mbsf indicating downward advection of fluid above that level. The lack of deep convection is especially remarkable given that the long-lived Lost City Hydrothermal Field (LCHF) is located only 5km to the south. We have modelled hydrothermal circulation in the Massif using Comsol Multiphysics, comparing 2-D and 3-D topographic models and using temperature-dependent conductivity to give the best estimate of heatflow into the Massif. We can constrain maximum permeability in gabbro below 750 mbsf to 5e-17 m2. The thermal gradient in the upper part of the borehole can be matched with a permeability of 3e-14 m2 in a 750 m thick layer parallel to the surface of the massif, with upflow occurring in areas of high topography and downflow at the location of the borehole. However in 3-D the precise flow pattern is quite model dependent, and the thermal structure can be matched either by downflow centred on the borehole at lower permeability or centred a few hundred metres from the borehole at higher permeability. The borehole gradient is compatible with the longevity (>120 kyr) and outflow temperature (40-90 °C) of the LCHF either with a deep more permeable (1e-14 m2 to 1e-15 m2) domain beneath the vent site in 2-D or a permeable fault slot 500 to 1000m wide and parallel to the transform fault in 3-D. In both cases topography
Regional geothermal 3D modelling in Denmark
NASA Astrophysics Data System (ADS)
Poulsen, S. E.; Balling, N.; Bording, T. S.; Nielsen, S. B.
2012-04-01
In the pursuit of sustainable and low carbon emission energy sources, increased global attention has been given to the exploration and exploitation of geothermal resources within recent decades. In 2009 a national multi-disciplinary geothermal research project was established. As a significant part of this project, 3D temperature modelling is to be carried out, with special emphasis on temperatures of potential geothermal reservoirs in the Danish area. The Danish subsurface encompasses low enthalpy geothermal reservoirs of mainly Triassic and Jurassic age. Geothermal plants at Amager (Copenhagen) and Thisted (Northern Jutland) have the capacity of supplying the district heating network with up to 14 MW and 7 MW, respectively, by withdrawing warm pore water from the Gassum (Lower Jurassic/Upper Triassic) and Bunter (Lower Triassic) sandstone reservoirs, respectively. Explorative studies of the subsurface temperature regime typically are based on a combination of observations and modelling. In this study, the open-source groundwater modelling code MODFLOW is modified to simulate the subsurface temperature distribution in three dimensions by taking advantage of the mathematical similarity between saturated groundwater flow (Darcy flow) and heat conduction. A numerical model of the subsurface geology in Denmark is built and parameterized from lithological information derived from joint interpretation of seismic surveys and borehole information. Boundary conditions are constructed from knowledge about the heat flow from the Earth's interior and the shallow ground temperature. Matrix thermal conductivities have been estimated from analysis of high-resolution temperature logs measured in deep wells and porosity-depth relations are included using interpreted main lithologies. The model takes into account the dependency of temperature and pressure on thermal conductivity. Moreover, a transient model based correction of the paleoclimatic thermal disturbance caused by the
NASA Astrophysics Data System (ADS)
Mather, B.; Moresi, L. N.; Cruden, A. R.
2014-12-01
Uncertainty of the lithospheric thermal regime greatly increases with depth. Measurements of temperature gradient and crustal rheology are concentrated in the upper crust, whereas the majority of the lithospheric measurements are approximated using empirical depth-dependent functions. We have applied a Monte Carlo approach to test the variation of crustal heat flow with temperature-dependent conductivity and the redistribution of heat-producing elements. The dense population of precision heat flow data in Victoria, Southeast Australia offers the ideal environment to test the variation of heat flow. A stochastically consistent anomalous zone of impossibly high Moho temperatures in the 3D model (> 900°C) correlates well with a zone of low teleseismic velocity and high electrical conductivity. This indicates that transient heat transfer has perturbed the thermal gradient and therefore a steady-state approach to 3D modelling is inappropriate in this zone. A spatial correlation between recent intraplate volcanic eruption points (< 5 Ma) and elevated Moho temperatures is a potential origin for additional latent heat in the crust.
3D Microperfusion Model of ADPKD
2015-10-01
Stratasys 3D printer . PDMS was cast in the negative molds in order to create permanent biocompatible plastic masters (SmoothCast 310). All goals of task...1 AWARD NUMBER: W81XWH-14-1-0304 TITLE: 3D Microperfusion Model of ADPKD PRINCIPAL INVESTIGATOR: David L. Kaplan CONTRACTING ORGANIZATION...ADDRESS. 1. REPORT DATE October 2015 2. REPORT TYPE Annual Report 3. DATES COVERED 15 Sep 2014 - 14 Sep 2015 4. TITLE AND SUBTITLE 3D
NASA Astrophysics Data System (ADS)
Xu, Bo; Li, Lin; Zhu, Ying
2014-11-01
Researches on hypersonic vehicles have been a hotspot in the field of aerospace because of the pursuits for higher speed by human being. Infrared imaging guidance is playing a very important role in modern warfare. When an Infrared Ray(IR) imaging guided missile is flying in the air at high speed, its optical dome suffers from serious aero-optic effects because of air flow. The turbulence around the dome and the thermal effects of the optical window would cause disturbance to the wavefront from the target. Therefore, detected images will be biased, dithered and blurred, and the capabilities of the seeker for detecting, tracking and recognizing are weakened. In this paper, methods for thermal and structural analysis with Heat Transfer and Elastic Mechanics are introduced. By studying the aero-thermal effects and aero-thermal radiation effects of the optical window, a 3D analysis model of the optical window is established by using finite element method. The direct coupling analysis is employed as a solving strategy. The variation regularity of the temperature field is obtained. For light with different incident angles, the influence on the ray propagation caused by window deformation is analyzed with theoretical calculation and optical/thermal/structural integrated analysis method respectively.
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.
Modeling cellular processes in 3D.
Mogilner, Alex; Odde, David
2011-12-01
Recent advances in photonic imaging and fluorescent protein technology offer unprecedented views of molecular space-time dynamics in living cells. At the same time, advances in computing hardware and software enable modeling of ever more complex systems, from global climate to cell division. As modeling and experiment become more closely integrated we must address the issue of modeling cellular processes in 3D. Here, we highlight recent advances related to 3D modeling in cell biology. While some processes require full 3D analysis, we suggest that others are more naturally described in 2D or 1D. Keeping the dimensionality as low as possible reduces computational time and makes models more intuitively comprehensible; however, the ability to test full 3D models will build greater confidence in models generally and remains an important emerging area of cell biological modeling.
NASA Astrophysics Data System (ADS)
Klinger, Carolin; Mayer, Bernhard
2016-01-01
Due to computational costs, radiation is usually neglected or solved in plane parallel 1D approximation in today's numerical weather forecast and cloud resolving models. We present a fast and accurate method to calculate 3D heating and cooling rates in the thermal spectral range that can be used in cloud resolving models. The parameterization considers net fluxes across horizontal box boundaries in addition to the top and bottom boundaries. Since the largest heating and cooling rates occur inside the cloud, close to the cloud edge, the method needs in first approximation only the information if a grid box is at the edge of a cloud or not. Therefore, in order to calculate the heating or cooling rates of a specific grid box, only the directly neighboring columns are used. Our so-called Neighboring Column Approximation (NCA) is an analytical consideration of cloud side effects which can be considered a convolution of a 1D radiative transfer result with a kernel or radius of 1 grid-box (5 pt stencil) and which does usually not break the parallelization of a cloud resolving model. The NCA can be easily applied to any cloud resolving model that includes a 1D radiation scheme. Due to the neglect of horizontal transport of radiation further away than one model column, the NCA works best for model resolutions of about 100 m or lager. In this paper we describe the method and show a set of applications of LES cloud field snap shots. Correction terms, gains and restrictions of the NCA are described. Comprehensive comparisons to the 3D Monte Carlo Model MYSTIC and a 1D solution are shown. In realistic cloud fields, the full 3D simulation with MYSTIC shows cooling rates up to -150 K/d (100 m resolution) while the 1D solution shows maximum coolings of only -100 K/d. The NCA is capable of reproducing the larger 3D cooling rates. The spatial distribution of the heating and cooling is improved considerably. Computational costs are only a factor of 1.5-2 higher compared to a 1D
RHOCUBE: 3D density distributions modeling code
NASA Astrophysics Data System (ADS)
Nikutta, Robert; Agliozzo, Claudia
2016-11-01
RHOCUBE models 3D density distributions on a discrete Cartesian grid and their integrated 2D maps. It can be used for a range of applications, including modeling the electron number density in LBV shells and computing the emission measure. The RHOCUBE Python package provides several 3D density distributions, including a powerlaw shell, truncated Gaussian shell, constant-density torus, dual cones, and spiralling helical tubes, and can accept additional distributions. RHOCUBE provides convenient methods for shifts and rotations in 3D, and if necessary, an arbitrary number of density distributions can be combined into the same model cube and the integration ∫ dz performed through the joint density field.
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
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.
A Hybrid 3D Indoor Space Model
NASA Astrophysics Data System (ADS)
Jamali, Ali; Rahman, Alias Abdul; Boguslawski, Pawel
2016-10-01
GIS integrates spatial information and spatial analysis. An important example of such integration is for emergency response which requires route planning inside and outside of a building. Route planning requires detailed information related to indoor and outdoor environment. Indoor navigation network models including Geometric Network Model (GNM), Navigable Space Model, sub-division model and regular-grid model lack indoor data sources and abstraction methods. In this paper, a hybrid indoor space model is proposed. In the proposed method, 3D modeling of indoor navigation network is based on surveying control points and it is less dependent on the 3D geometrical building model. This research proposes a method of indoor space modeling for the buildings which do not have proper 2D/3D geometrical models or they lack semantic or topological information. The proposed hybrid model consists of topological, geometrical and semantical space.
NASA Astrophysics Data System (ADS)
Fuchsluger, Martin; Götzl, Gregor
2014-05-01
flow has been realized. In addition the effects of the basement of the building to the groundwater flow have been analyzed. The results of the 2D model show an underestimation of more than 10 % of the performance of the groundwater utilization facility and a considerable smaller groundwater table drawdown compared to the 3D simulations. This is due to the possibility of 3D modeling to consider (i) the heat distribution and storage in the adjacent layers, (ii) the climatic surface effect and (iii) vertical groundwater flow.
3D Modeling Engine Representation Summary Report
Steven Prescott; Ramprasad Sampath; Curtis Smith; Timothy Yang
2014-09-01
Computers have been used for 3D modeling and simulation, but only recently have computational resources been able to give realistic results in a reasonable time frame for large complex models. This summary report addressed the methods, techniques, and resources used to develop a 3D modeling engine to represent risk analysis simulation for advanced small modular reactor structures and components. The simulations done for this evaluation were focused on external events, specifically tsunami floods, for a hypothetical nuclear power facility on a coastline.
BEAMS3D Neutral Beam Injection Model
NASA Astrophysics Data System (ADS)
McMillan, Matthew; Lazerson, Samuel A.
2014-09-01
With the advent of applied 3D fields in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous slowing down, and pitch angle scattering are modeled with the ADAS atomic physics database. Elementary benchmark calculations are presented to verify the collisionless particle orbits, NBI model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields. Notice: this manuscript has been authored by Princeton University under Contract Number DE-AC02-09CH11466 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.
ERIC Educational Resources Information Center
Bradley, Joan; Farland-Smith, Donna
2010-01-01
Allowing a student to "see" through touch what other students see through a microscope can be a challenging task. Therefore, author Joan Bradley created three-dimensional (3-D) models with one student's visual impairment in mind. They are meant to benefit all students and can be used to teach common high school biology topics, including the…
Constructing Arguments with 3-D Printed Models
ERIC Educational Resources Information Center
McConnell, William; Dickerson, Daniel
2017-01-01
In this article, the authors describe a fourth-grade lesson where 3-D printing technologies were not only a stimulus for engagement but also served as a modeling tool providing meaningful learning opportunities. Specifically, fourth-grade students construct an argument that animals' external structures function to support survival in a particular…
Model-based 3D SAR reconstruction
NASA Astrophysics Data System (ADS)
Knight, Chad; Gunther, Jake; Moon, Todd
2014-06-01
Three dimensional scene reconstruction with synthetic aperture radar (SAR) is desirable for target recognition and improved scene interpretability. The vertical aperture, which is critical to reconstruct 3D SAR scenes, is almost always sparsely sampled due to practical limitations, which creates an underdetermined problem. This papers explores 3D scene reconstruction using a convex model-based approach. The approach developed is demonstrated on 3D scenes, but can be extended to SAR reconstruction of sparsely sampled signals in the spatial and, or, frequency domains. The model-based approach enables knowledge-aided image formation (KAIF) by incorporating spatial, aspect, and sparsity magnitude terms into the image reconstruction. The incorporation of these terms, which are based on prior scene knowledge, will demonstrate improved results compared to traditional image formation algorithms. The SAR image formation problem is formulated as a second order cone program (SOCP) and the results are demonstrated on 3D scenes using simulated data and data from the GOTCHA data collect.1 The model-based results are contrasted against traditional backprojected images.
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…
Debris Dispersion Model Using Java 3D
NASA Technical Reports Server (NTRS)
Thirumalainambi, Rajkumar; Bardina, Jorge
2004-01-01
This paper describes web based simulation of Shuttle launch operations and debris dispersion. Java 3D graphics provides geometric and visual content with suitable mathematical model and behaviors of Shuttle launch. Because the model is so heterogeneous and interrelated with various factors, 3D graphics combined with physical models provides mechanisms to understand the complexity of launch and range operations. The main focus in the modeling and simulation covers orbital dynamics and range safety. Range safety areas include destruct limit lines, telemetry and tracking and population risk near range. If there is an explosion of Shuttle during launch, debris dispersion is explained. The shuttle launch and range operations in this paper are discussed based on the operations from Kennedy Space Center, Florida, USA.
Illustrative visualization of 3D city models
NASA Astrophysics Data System (ADS)
Doellner, Juergen; Buchholz, Henrik; Nienhaus, Marc; Kirsch, Florian
2005-03-01
This paper presents an illustrative visualization technique that provides expressive representations of large-scale 3D city models, inspired by the tradition of artistic and cartographic visualizations typically found in bird"s-eye view and panoramic maps. We define a collection of city model components and a real-time multi-pass rendering algorithm that achieves comprehensible, abstract 3D city model depictions based on edge enhancement, color-based and shadow-based depth cues, and procedural facade texturing. Illustrative visualization provides an effective visual interface to urban spatial information and associated thematic information complementing visual interfaces based on the Virtual Reality paradigm, offering a huge potential for graphics design. Primary application areas include city and landscape planning, cartoon worlds in computer games, and tourist information systems.
NASA Astrophysics Data System (ADS)
Bermudez, M. A.; Baldwin, S.; Fitzgerald, P. G.; Braun, J.
2012-12-01
The world's youngest eclogites, exhumed from depths of ca. 90 km since 8 Ma, are located in the D'Entrecasteaux Islands in the active Woodlark rift of southeastern Papua New Guinea. These (U)HP rocks formed during/following subduction of Australian margin-derived volcaniclastic sediments, and were exhumed during rifting within the larger, obliquely convergent Australian-Pacific plate boundary zone. Several (U)HP exhumation mechanisms have been proposed including diapiric rise of buoyant crust from mantle to crustal depths, and rifting of heterogeneous crust ahead of the east-to-west propagating Woodlark seafloor spreading center. In order to constrain the relative importance of different exhumation mechanisms through time (i.e., timing and rates of diapirism vs crustal faulting), we apply 3D thermo-kinematic modeling (Pecube) to constrain cooling and exhumation histories derived from thermochronologic data from Goodenough Island, the western-most of the D'Entrecasteaux Islands. More than 500,000 Pecube inverse models were run to evaluate scenarios involving vertical exhumation velocities (i.e., simulating simple buoyancy due to diapirism), low-angle normal faulting and combinations of both processes. These preliminary models assume steady-state topography. Preliminary models (starting at 8 Ma) include: (i) continuous exhumation, (ii) two exhumation phases with different exhumation rates (increasing and/or decreasing), and (iii) three exhumation phases with variable exhumation rates. For buoyancy-only models, the first two scenarios (i and ii) result in poor fits between model-derived and observed (experimental) data. Notably, scenarios (i) and (ii) produce indistinguishable ages for all thermochronologic systems, uniformly long apatite fission-track (AFT) lengths, excessive temperatures at the Moho and geological starting parameters (depth, T) that are not consistent with other data. Scenario (iii) with three exhumation phases has the least misfit between model
3-D model-based vehicle tracking.
Lou, Jianguang; Tan, Tieniu; Hu, Weiming; Yang, Hao; Maybank, Steven J
2005-10-01
This paper aims at tracking vehicles from monocular intensity image sequences and presents an efficient and robust approach to three-dimensional (3-D) model-based vehicle tracking. Under the weak perspective assumption and the ground-plane constraint, the movements of model projection in the two-dimensional image plane can be decomposed into two motions: translation and rotation. They are the results of the corresponding movements of 3-D translation on the ground plane (GP) and rotation around the normal of the GP, which can be determined separately. A new metric based on point-to-line segment distance is proposed to evaluate the similarity between an image region and an instantiation of a 3-D vehicle model under a given pose. Based on this, we provide an efficient pose refinement method to refine the vehicle's pose parameters. An improved EKF is also proposed to track and to predict vehicle motion with a precise kinematics model. Experimental results with both indoor and outdoor data show that the algorithm obtains desirable performance even under severe occlusion and clutter.
Sensing and compressing 3-D models
Krumm, J.
1998-02-01
The goal of this research project was to create a passive and robust computer vision system for producing 3-D computer models of arbitrary scenes. Although the authors were unsuccessful in achieving the overall goal, several components of this research have shown significant potential. Of particular interest is the application of parametric eigenspace methods for planar pose measurement of partially occluded objects in gray-level images. The techniques presented provide a simple, accurate, and robust solution to the planar pose measurement problem. In addition, the representational efficiency of eigenspace methods used with gray-level features were successfully extended to binary features, which are less sensitive to illumination changes. The results of this research are presented in two papers that were written during the course of this project. The papers are included in sections 2 and 3. The first section of this report summarizes the 3-D modeling efforts.
3D shape measurement with thermal pattern projection
NASA Astrophysics Data System (ADS)
Brahm, Anika; Reetz, Edgar; Schindwolf, Simon; Correns, Martin; Kühmstedt, Peter; Notni, Gunther
2016-12-01
Structured light projection techniques are well-established optical methods for contactless and nondestructive three-dimensional (3D) measurements. Most systems operate in the visible wavelength range (VIS) due to commercially available projection and detection technology. For example, the 3D reconstruction can be done with a stereo-vision setup by finding corresponding pixels in both cameras followed by triangulation. Problems occur, if the properties of object materials disturb the measurements, which are based on the measurement of diffuse light reflections. For example, there are existing materials in the VIS range that are too transparent, translucent, high absorbent, or reflective and cannot be recorded properly. To overcome these challenges, we present an alternative thermal approach that operates in the infrared (IR) region of the electromagnetic spectrum. For this purpose, we used two cooled mid-wave (MWIR) cameras (3-5 μm) to detect emitted heat patterns, which were introduced by a CO2 laser. We present a thermal 3D system based on a GOBO (GOes Before Optics) wheel projection unit and first 3D analyses for different system parameters and samples. We also show a second alternative approach based on an incoherent (heat) source, to overcome typical disadvantages of high-power laser-based systems, such as industrial health and safety considerations, as well as high investment costs. Thus, materials like glass or fiber-reinforced composites can be measured contactless and without the need of additional paintings.
NASA Astrophysics Data System (ADS)
Mitra, Sunanda
1992-11-01
Different approaches to computational stereo to represent human stereo vision have been developed over the past two decades. The Marr-Poggio theory of human stereo vision is probably the most widely accepted model of the human stereo vision. However, recently developed motion stereo models which use a sequence of images taken by either a moving camera or a moving object provide an alternative method of achieving multi-resolution matching without the use of Laplacian of Gaussian operators. While using image sequences, the baseline between two camera positions for a image pair is changed for the subsequent image pair so as to achieve different resolution for each image pair. Having different baselines also avoids the inherent occlusion problem in stereo vision models. The advantage of using multi-resolution images acquired by camera positioned at different baselines over those acquired by LOG operators is that one does not have to encounter spurious edges often created by zero-crossings in the LOG operated images. Therefore in designing a computer vision system, a motion stereo model is more appropriate than a stereo vision model. However, in some applications where only a stereo pair of images are available, recovery of 3D surfaces of natural scenes are possible in a computationally efficient manner by using cepstrum matching and regularization techniques. Section 2 of this paper describes a motion stereo model using multi-scale cepstrum matching for the detection of disparity between image pairs in a sequence of images and subsequent recovery of 3D surfaces from depth-map obtained by a non convergent triangulation technique. Section 3 presents a 3D surface recovery technique from a stereo pair using cepstrum matching for disparity detection and cubic B-splines for surface smoothing. Section 4 contains the results of 3D surface recovery using both of the techniques mentioned above. Section 5 discusses the merit of 2D cepstrum matching and cubic B
3-D HYDRODYNAMIC MODELING IN A GEOSPATIAL FRAMEWORK
Bollinger, J; Alfred Garrett, A; Larry Koffman, L; David Hayes, D
2006-08-24
3-D hydrodynamic models are used by the Savannah River National Laboratory (SRNL) to simulate the transport of thermal and radionuclide discharges in coastal estuary systems. Development of such models requires accurate bathymetry, coastline, and boundary condition data in conjunction with the ability to rapidly discretize model domains and interpolate the required geospatial data onto the domain. To facilitate rapid and accurate hydrodynamic model development, SRNL has developed a pre- and post-processor application in a geospatial framework to automate the creation of models using existing data. This automated capability allows development of very detailed models to maximize exploitation of available surface water radionuclide sample data and thermal imagery.
NASA Astrophysics Data System (ADS)
Berchtold, Waldemar; Schäfer, Marcel; Rettig, Michael; Steinebach, Martin
2014-02-01
3D models and applications are of utmost interest in both science and industry. With the increment of their usage, their number and thereby the challenge to correctly identify them increases. Content identification is commonly done by cryptographic hashes. However, they fail as a solution in application scenarios such as computer aided design (CAD), scientific visualization or video games, because even the smallest alteration of the 3D model, e.g. conversion or compression operations, massively changes the cryptographic hash as well. Therefore, this work presents a robust hashing algorithm for 3D mesh data. The algorithm applies several different bit extraction methods. They are built to resist desired alterations of the model as well as malicious attacks intending to prevent correct allocation. The different bit extraction methods are tested against each other and, as far as possible, the hashing algorithm is compared to the state of the art. The parameters tested are robustness, security and runtime performance as well as False Acceptance Rate (FAR) and False Rejection Rate (FRR), also the probability calculation of hash collision is included. The introduced hashing algorithm is kept adaptive e.g. in hash length, to serve as a proper tool for all applications in practice.
Fallon FORGE 3D Geologic Model
Doug Blankenship
2016-03-01
An x,y,z scattered data file for the 3D geologic model of the Fallon FORGE site. Model created in Earthvision by Dynamic Graphic Inc. The model was constructed with a grid spacing of 100 m. Geologic surfaces were extrapolated from the input data using a minimum tension gridding algorithm. The data file is tabular data in a text file, with lithology data associated with X,Y,Z grid points. All the relevant information is in the file header (the spatial reference, the projection etc.) In addition all the fields in the data file are identified in the header.
Inferential modeling of 3D chromatin structure.
Wang, Siyu; Xu, Jinbo; Zeng, Jianyang
2015-04-30
For eukaryotic cells, the biological processes involving regulatory DNA elements play an important role in cell cycle. Understanding 3D spatial arrangements of chromosomes and revealing long-range chromatin interactions are critical to decipher these biological processes. In recent years, chromosome conformation capture (3C) related techniques have been developed to measure the interaction frequencies between long-range genome loci, which have provided a great opportunity to decode the 3D organization of the genome. In this paper, we develop a new Bayesian framework to derive the 3D architecture of a chromosome from 3C-based data. By modeling each chromosome as a polymer chain, we define the conformational energy based on our current knowledge on polymer physics and use it as prior information in the Bayesian framework. We also propose an expectation-maximization (EM) based algorithm to estimate the unknown parameters of the Bayesian model and infer an ensemble of chromatin structures based on interaction frequency data. We have validated our Bayesian inference approach through cross-validation and verified the computed chromatin conformations using the geometric constraints derived from fluorescence in situ hybridization (FISH) experiments. We have further confirmed the inferred chromatin structures using the known genetic interactions derived from other studies in the literature. Our test results have indicated that our Bayesian framework can compute an accurate ensemble of 3D chromatin conformations that best interpret the distance constraints derived from 3C-based data and also agree with other sources of geometric constraints derived from experimental evidence in the previous studies. The source code of our approach can be found in https://github.com/wangsy11/InfMod3DGen.
Gis-Based Smart Cartography Using 3d Modeling
NASA Astrophysics Data System (ADS)
Malinverni, E. S.; Tassetti, A. N.
2013-08-01
3D City Models have evolved to be important tools for urban decision processes and information systems, especially in planning, simulation, analysis, documentation and heritage management. On the other hand existing and in use numerical cartography is often not suitable to be used in GIS because not geometrically and topologically correctly structured. The research aim is to 3D structure and organize a numeric cartography for GIS and turn it into CityGML standardized features. The work is framed around a first phase of methodological analysis aimed to underline which existing standard (like ISO and OGC rules) can be used to improve the quality requirement of a cartographic structure. Subsequently, from this technical specifics, it has been investigated the translation in formal contents, using an owner interchange software (SketchUp), to support some guide lines implementations to generate a GIS3D structured in GML3. It has been therefore predisposed a test three-dimensional numerical cartography (scale 1:500, generated from range data captured by 3D laser scanner), tested on its quality according to the previous standard and edited when and where necessary. Cad files and shapefiles are converted into a final 3D model (Google SketchUp model) and then exported into a 3D city model (CityGML LoD1/LoD2). The GIS3D structure has been managed in a GIS environment to run further spatial analysis and energy performance estimate, not achievable in a 2D environment. In particular geometrical building parameters (footprint, volume etc.) are computed and building envelop thermal characteristics are derived from. Lastly, a simulation is carried out to deal with asbestos and home renovating charges and show how the built 3D city model can support municipal managers with risk diagnosis of the present situation and development of strategies for a sustainable redevelop.
3D Model of Surfactant Replacement Therapy
NASA Astrophysics Data System (ADS)
Grotberg, James; Tai, Cheng-Feng; Filoche, Marcel
2015-11-01
Surfactant Replacement Therapy (SRT) involves instillation of a liquid-surfactant mixture directly into the lung airway tree. Though successful in neonatal applications, its use in adults had early success followed by failure. We present the first mathematical model of 3D SRT where a liquid plug propagates through the tree from forced inspiration. In two separate modeling steps, the plug first deposits a coating film on the airway wall which subtracts from its volume, a ``coating cost''. Then the plug splits unevenly at the airway bifurcation due to gravity. The steps are repeated until a plug ruptures or reaches the tree endpoint alveoli/acinus. The model generates 3D images of the resulting acinar distribution and calculates two global indexes, efficiency and homogeneity. Simulating published literature, the earlier successful adult SRT studies show comparatively good index values, while the later failed studies do not. Those unsuccessful studies used smaller dose volumes with higher concentration mixtures, apparently assuming a well mixed compartment. The model shows that adult lungs are not well mixed in SRT due to the coating cost and gravity effects. Returning to the higher dose volume protocols could save many thousands of lives annually in the US. Supported by NIH Grants HL85156, HL84370 and Agence Nationale de la Recherche, ANR no. 2010-BLAN-1119-05.
MOSSFRAC: An anisotropic 3D fracture model
Moss, W C; Levatin, J L
2006-08-14
Despite the intense effort for nearly half a century to construct detailed numerical models of plastic flow and plastic damage accumulation, models for describing fracture, an equally important damage mechanism still cannot describe basic fracture phenomena. Typical fracture models set the stress tensor to zero for tensile fracture and set the deviatoric stress tensor to zero for compressive fracture. One consequence is that the simple case of the tensile fracture of a cylinder under combined compressive radial and tensile axial loads is not modeled correctly. The experimental result is a cylinder that can support compressive radial loads, but no axial load, whereas, the typical numerical result is a cylinder with all stresses equal to zero. This incorrect modeling of fracture locally also has a global effect, because material that is fracturing produces stress release waves, which propagate from the fracture and influence the surrounding material. Consequently, it would be useful to have a model that can describe the stress relief and the resulting anisotropy due to fracture. MOSSFRAC is a material model that simulates three-dimensional tensile and shear fracture in initially isotropic elastic-plastic materials, although its framework is also amenable to initially anisotropic materials. It differs from other models by accounting for the effects of cracks on the constitutive response of the material, so that the previously described experiment, as well as complicated fracture scenarios are simulated more accurately. The model is implemented currently in the LLNL hydrocodes DYNA3D, PARADYN, and ALE3D. The purpose of this technical note is to present a complete qualitative description of the model and quantitative descriptions of salient features.
3D Stratigraphic Modeling of Central Aachen
NASA Astrophysics Data System (ADS)
Dong, M.; Neukum, C.; Azzam, R.; Hu, H.
2010-05-01
Since 1980s, advanced computer hardware and software technologies, as well as multidisciplinary research have provided possibilities to develop advanced three dimensional (3D) simulation software for geosciences application. Some countries, such as USA1) and Canada2) 3), have built up regional 3D geological models based on archival geological data. Such models have played huge roles in engineering geology2), hydrogeology2) 3), geothermal industry1) and so on. In cooperating with the Municipality of Aachen, the Department of Engineering Geology of RWTH Aachen University have built up a computer-based 3D stratigraphic model of 50 meter' depth for the center of Aachen, which is a 5 km by 7 km geologically complex area. The uncorrelated data from multi-resources, discontinuous nature and unconformable connection of the units are main challenges for geological modeling in this area. The reliability of 3D geological models largely depends on the quality and quantity of data. Existing 1D and 2D geological data were collected, including 1) approximately 6970 borehole data of different depth compiled in Microsoft Access database and MapInfo database; 2) a Digital Elevation Model (DEM); 3) geological cross sections; and 4) stratigraphic maps in 1m, 2m and 5m depth. Since acquired data are of variable origins, they were managed step by step. The main processes are described below: 1) Typing errors of borehole data were identified and the corrected data were exported to Variowin2.2 to distinguish duplicate points; 2) The surface elevation of borehole data was compared to the DEM, and differences larger than 3m were eliminated. Moreover, where elevation data missed, it was read from the DEM; 3) Considerable data were collected from municipal constructions, such as residential buildings, factories, and roads. Therefore, many boreholes are spatially clustered, and only one or two representative points were picked out in such areas; After above procedures, 5839 boreholes with -x
SB3D User Manual, Santa Barbara 3D Radiative Transfer Model
O'Hirok, William
1999-01-01
SB3D is a three-dimensional atmospheric and oceanic radiative transfer model for the Solar spectrum. The microphysics employed in the model are the same as used in the model SBDART. It is assumed that the user of SB3D is familiar with SBDART and IDL. SB3D differs from SBDART in that computations are conducted on media in three-dimensions rather than a single column (i.e. plane-parallel), and a stochastic method (Monte Carlo) is employed instead of a numerical approach (Discrete Ordinates) for estimating a solution to the radiative transfer equation. Because of these two differences between SB3D and SBDART, the input and running of SB3D is more unwieldy and requires compromises between model performance and computational expense. Hence, there is no one correct method for running the model and the user must develop a sense to the proper input and configuration of the model.
Reservoir geology using 3D modelling tools
Dubrule, O.; Samson, P.; Segonds, D.
1996-12-31
The last decade has seen tremendous developments in the area of quantitative geological modelling. These developments have a significant impact on the current practice of constructing reservoir models. A structural model can first be constructed on the basis of depth-converted structural interpretations produced on a seismic interpretation workstation. Surfaces and faults can be represented as geological objects, and interactively modified. Once the tectonic framework has been obtained, intermediate stratigraphic surfaces can be constructed between the main structural surfaces. Within each layer, reservoir attributes can be represented using various techniques. Examples show how the distribution of different facies (i.e. from fine to coarse grain) can be represented, or how various depositional units (for instance channels, crevasses and lobes in a turbidite setting) can be modelled as geological {open_quotes}objects{close_quotes} with complex geometries. Elf Aquitaine, in close co-operation with the GOCAD project in Nancy (France) is investigating how geological models can be made more realistic by developing interactive functionalities. Examples show that, contrary to standard deterministic or geostatistical modelling techniques (which tend to be difficult to control) the use of new 3D tools allows the geologist to interactively modify geological surfaces (including faults) or volumetric properties. Thus, the sensitivity of various economic parameters (oil in place, connected volumes, reserves) to major geological uncertainties can be evaluated. It is argued that future breakthroughs in geological modelling techniques are likely to happen in the development of interactive approaches rather than in the research of new mathematical algorithms.
Reservoir geology using 3D modelling tools
Dubrule, O. ); Samson, P. ); Segonds, D. )
1996-01-01
The last decade has seen tremendous developments in the area of quantitative geological modelling. These developments have a significant impact on the current practice of constructing reservoir models. A structural model can first be constructed on the basis of depth-converted structural interpretations produced on a seismic interpretation workstation. Surfaces and faults can be represented as geological objects, and interactively modified. Once the tectonic framework has been obtained, intermediate stratigraphic surfaces can be constructed between the main structural surfaces. Within each layer, reservoir attributes can be represented using various techniques. Examples show how the distribution of different facies (i.e. from fine to coarse grain) can be represented, or how various depositional units (for instance channels, crevasses and lobes in a turbidite setting) can be modelled as geological [open quotes]objects[close quotes] with complex geometries. Elf Aquitaine, in close co-operation with the GOCAD project in Nancy (France) is investigating how geological models can be made more realistic by developing interactive functionalities. Examples show that, contrary to standard deterministic or geostatistical modelling techniques (which tend to be difficult to control) the use of new 3D tools allows the geologist to interactively modify geological surfaces (including faults) or volumetric properties. Thus, the sensitivity of various economic parameters (oil in place, connected volumes, reserves) to major geological uncertainties can be evaluated. It is argued that future breakthroughs in geological modelling techniques are likely to happen in the development of interactive approaches rather than in the research of new mathematical algorithms.
Scalable 3D GIS environment managed by 3D-XML-based modeling
NASA Astrophysics Data System (ADS)
Shi, Beiqi; Rui, Jianxun; Chen, Neng
2008-10-01
Nowadays, the namely 3D GIS technologies become a key factor in establishing and maintaining large-scale 3D geoinformation services. However, with the rapidly increasing size and complexity of the 3D models being acquired, a pressing needed for suitable data management solutions has become apparent. This paper outlines that storage and exchange of geospatial data between databases and different front ends like 3D models, GIS or internet browsers require a standardized format which is capable to represent instances of 3D GIS models, to minimize loss of information during data transfer and to reduce interface development efforts. After a review of previous methods for spatial 3D data management, a universal lightweight XML-based format for quick and easy sharing of 3D GIS data is presented. 3D data management based on XML is a solution meeting the requirements as stated, which can provide an efficient means for opening a new standard way to create an arbitrary data structure and share it over the Internet. To manage reality-based 3D models, this paper uses 3DXML produced by Dassault Systemes. 3DXML uses opening XML schemas to communicate product geometry, structure and graphical display properties. It can be read, written and enriched by standard tools; and allows users to add extensions based on their own specific requirements. The paper concludes with the presentation of projects from application areas which will benefit from the functionality presented above.
Automated modeling of RNA 3D structure.
Rother, Kristian; Rother, Magdalena; Skiba, Pawel; Bujnicki, Janusz M
2014-01-01
This chapter gives an overview over the current methods for automated modeling of RNA structures, with emphasis on template-based methods. The currently used approaches to RNA modeling are presented with a side view on the protein world, where many similar ideas have been used. Two main programs for automated template-based modeling are presented: ModeRNA assembling structures from fragments and MacroMoleculeBuilder performing a simulation to satisfy spatial restraints. Both approaches have in common that they require an alignment of the target sequence to a known RNA structure that is used as a modeling template. As a way to find promising template structures and to align the target and template sequences, we propose a pipeline combining the ParAlign and Infernal programs on RNA family data from Rfam. We also briefly summarize template-free methods for RNA 3D structure prediction. Typically, RNA structures generated by automated modeling methods require local or global optimization. Thus, we also discuss methods that can be used for local or global refinement of RNA structures.
3D Modelling of Kizildag Monument
NASA Astrophysics Data System (ADS)
Karauguz, Güngör; Kalayci, İbrahim; Öğütcü, Sermet
2016-10-01
The most important cultural property that the nations possess is their historical accumulation, and bringing these to light, taking measures to preserve them or at least maintain the continuity of transferring them to next generations by means of recent technic and technology, ought to be the business of present generations. Although, nowadays, intensive documentation and archiving studies are done by means of classical techniques, besides studies towards preserving historical objects, modelling one-to-one or scaled modelling were not possible until recently. Computing devices and the on-going reflection of this, which is acknowledged as digital technology, is widely used in many areas and makes it possible to document and archive historical works. Even virtual forms in quantitative environments can be transferred to next generations in a scaled and one-to-one modelled way. Within this scope, every single artefact categorization belonging to any era or civilization present in our country can be considered in separate study areas. Furthermore, any work or likewise can be evaluated in separate categories. Also, it is possible to construct travelable virtual 3D museums that make it possible to visit these artefacts. Under the auspices of these technologies, it is quite possible to construct single virtual indoor museums or also, at the final stage, a 3D travelable open-air museum, a platform or more precisely, to establish a data system that spreads all over the country on a broad spectrum. With a long-termed, significant and extensive study and a substantial organization, such a data system can be established, which also serves as a serious infrastructure for alternative tourism possibilities. Located beside a stepped altar and right above the Kizildag IV inscription, the offering pot is destructed and rolled away a few meters to the south slope of the mould. Every time visiting these artefacts with our undergraduate students, unfortunately, we observe more
Wear Analysis of Thermal Spray Coatings on 3D Surfaces
NASA Astrophysics Data System (ADS)
Tillmann, W.; Luo, W.; Selvadurai, U.
2014-01-01
Even though the application of thermal spray coatings on complex geometries gained a greater interest in the last decade, the effect of different geometrical features on the wear behavior is still ill-defined. In this study, the wear resistance of FTC-FeCSiMn coated 3D surfaces was investigated. The wear test was carried out by means of two innovative testing procedures. The first test is a Pin-on-Tubes test where the rotating motion is realized by a lathe chuck. The specimens in the second test were fixed on the table and a robot arm operated the pin. This wear test was applied on specimens with concave or convex surfaces. The residual stresses, which were determined by means of an incremental hole-drilling method, show a dependency on the substrate geometry. The obtained stresses were put in relation to the different radii. After the wear test, a 3D-profilometer determined the wear volume and the sections of the coatings were characterized by a scanning electron microscope. The results indicate that the wear resistance is strongly influenced by the geometry of the substrate.
3D Geological Model for "LUSI" - a Deep Geothermal System
NASA Astrophysics Data System (ADS)
Sohrabi, Reza; Jansen, Gunnar; Mazzini, Adriano; Galvan, Boris; Miller, Stephen A.
2016-04-01
Geothermal applications require the correct simulation of flow and heat transport processes in porous media, and many of these media, like deep volcanic hydrothermal systems, host a certain degree of fracturing. This work aims to understand the heat and fluid transport within a new-born sedimentary hosted geothermal system, termed Lusi, that began erupting in 2006 in East Java, Indonesia. Our goal is to develop conceptual and numerical models capable of simulating multiphase flow within large-scale fractured reservoirs such as the Lusi region, with fractures of arbitrary size, orientation and shape. Additionally, these models can also address a number of other applications, including Enhanced Geothermal Systems (EGS), CO2 sequestration (Carbon Capture and Storage CCS), and nuclear waste isolation. Fractured systems are ubiquitous, with a wide-range of lengths and scales, making difficult the development of a general model that can easily handle this complexity. We are developing a flexible continuum approach with an efficient, accurate numerical simulator based on an appropriate 3D geological model representing the structure of the deep geothermal reservoir. Using previous studies, borehole information and seismic data obtained in the framework of the Lusi Lab project (ERC grant n°308126), we present here the first 3D geological model of Lusi. This model is calculated using implicit 3D potential field or multi-potential fields, depending on the geological context and complexity. This method is based on geological pile containing the geological history of the area and relationship between geological bodies allowing automatic computation of intersections and volume reconstruction. Based on the 3D geological model, we developed a new mesh algorithm to create hexahedral octree meshes to transfer the structural geological information for 3D numerical simulations to quantify Thermal-Hydraulic-Mechanical-Chemical (THMC) physical processes.
Three-dimensional (3D) shadowgraph technique visualizes thermal convection
NASA Astrophysics Data System (ADS)
Huang, Jinzi; Zhang, Jun; Physics; Maths Research Institutes, NYU Shanghai Team; Applied Maths Lab, NYU Team
2016-11-01
Shadowgraph technique has been widely used in thermal convection, and in other types of convection and advection processes in fluids. The technique reveals minute density differences in the fluid, which is otherwise transparent to the eyes and to light-sensitive devices. However, such technique normally integrates the fluid information along the depth of view and collapses the 3D density field onto a 2D plane. In this work, we introduce a stereoscopic shadowgraph technique that preserves the information of the fluid depth by using two cross-field shadowgraphs. The two shadowgraphs are coded with different and complementary colors, and each is seen by only one eye of the viewer. The two shadowgraphs can also be temporally modulated to achieve the same stereoscopic vision of the convective fluid. We further discuss ways to make use of this technique in order to extract useful information for research in fluids.
3-D physical models of amitosis (cytokinesis).
Cheng, Kang; Zou, Changhua
2005-01-01
Based on Newton's laws, extended Coulomb's law and published biological data, we develop our 3-D physical models of natural and normal amitosis (cytokinesis), for prokaryotes (bacterial cells) in M phase. We propose following hypotheses: Chromosome rings exclusion: No normally and naturally replicated chromosome rings (RCR) can occupy the same prokaryote, a bacterial cell. The RCR produce spontaneous and strong electromagnetic fields (EMF), that can be alternated environmentally, in protoplasm and cortex. The EMF is approximately a repulsive quasi-static electric (slowly variant and mostly electric) field (EF). The EF forces between the RCR are strong enough, and orderly accumulate contractile proteins that divide the procaryotes in the cell cortex of division plane or directly split the cell compartment envelope longitudinally. The radial component of the EF forces could also make furrows or cleavages of procaryotes. The EF distribution controls the protoplasm partition and completes the amitosis (cytokinesis). After the cytokinesis, the spontaneous and strong EF disappear because the net charge accumulation becomes weak, in the protoplasm. The exclusion is because the two sets of informative objects (RCR) have identical DNA codes information and they are electro magnetically identical, therefore they repulse from each other. We also compare divisions among eukaryotes, prokaryotes, mitochondria and chloroplasts and propose our hypothesis: The principles of our models are applied to divisions of mitochondria and chloroplasts of eucaryotes too because these division mechanisms are closer than others in a view of physics. Though we develop our model using 1 division plane (i.e., 1 cell is divided into 2 cells) as an example, the principle of our model is applied to the cases with multiple division planes (i.e., 1 cell is divided into multiple cells) too.
Estimation of the thermal conductivity of hemp based insulation material from 3D tomographic images
NASA Astrophysics Data System (ADS)
El-Sawalhi, R.; Lux, J.; Salagnac, P.
2016-08-01
In this work, we are interested in the structural and thermal characterization of natural fiber insulation materials. The thermal performance of these materials depends on the arrangement of fibers, which is the consequence of the manufacturing process. In order to optimize these materials, thermal conductivity models can be used to correlate some relevant structural parameters with the effective thermal conductivity. However, only a few models are able to take into account the anisotropy of such material related to the fibers orientation, and these models still need realistic input data (fiber orientation distribution, porosity, etc.). The structural characteristics are here directly measured on a 3D tomographic image using advanced image analysis techniques. Critical structural parameters like porosity, pore and fiber size distribution as well as local fiber orientation distribution are measured. The results of the tested conductivity models are then compared with the conductivity tensor obtained by numerical simulation on the discretized 3D microstructure, as well as available experimental measurements. We show that 1D analytical models are generally not suitable for assessing the thermal conductivity of such anisotropic media. Yet, a few anisotropic models can still be of interest to relate some structural parameters, like the fiber orientation distribution, to the thermal properties. Finally, our results emphasize that numerical simulations on 3D realistic microstructure is a very interesting alternative to experimental measurements.
Multi-view and 3D deformable part models.
Pepik, Bojan; Stark, Michael; Gehler, Peter; Schiele, Bernt
2015-11-01
As objects are inherently 3D, they have been modeled in 3D in the early days of computer vision. Due to the ambiguities arising from mapping 2D features to 3D models, 3D object representations have been neglected and 2D feature-based models are the predominant paradigm in object detection nowadays. While such models have achieved outstanding bounding box detection performance, they come with limited expressiveness, as they are clearly limited in their capability of reasoning about 3D shape or viewpoints. In this work, we bring the worlds of 3D and 2D object representations closer, by building an object detector which leverages the expressive power of 3D object representations while at the same time can be robustly matched to image evidence. To that end, we gradually extend the successful deformable part model [1] to include viewpoint information and part-level 3D geometry information, resulting in several different models with different level of expressiveness. We end up with a 3D object model, consisting of multiple object parts represented in 3D and a continuous appearance model. We experimentally verify that our models, while providing richer object hypotheses than the 2D object models, provide consistently better joint object localization and viewpoint estimation than the state-of-the-art multi-view and 3D object detectors on various benchmarks (KITTI [2] , 3D object classes [3] , Pascal3D+ [4] , Pascal VOC 2007 [5] , EPFL multi-view cars[6] ).
3D-GNOME: an integrated web service for structural modeling of the 3D genome.
Szalaj, Przemyslaw; Michalski, Paul J; Wróblewski, Przemysław; Tang, Zhonghui; Kadlof, Michal; Mazzocco, Giovanni; Ruan, Yijun; Plewczynski, Dariusz
2016-07-08
Recent advances in high-throughput chromosome conformation capture (3C) technology, such as Hi-C and ChIA-PET, have demonstrated the importance of 3D genome organization in development, cell differentiation and transcriptional regulation. There is now a widespread need for computational tools to generate and analyze 3D structural models from 3C data. Here we introduce our 3D GeNOme Modeling Engine (3D-GNOME), a web service which generates 3D structures from 3C data and provides tools to visually inspect and annotate the resulting structures, in addition to a variety of statistical plots and heatmaps which characterize the selected genomic region. Users submit a bedpe (paired-end BED format) file containing the locations and strengths of long range contact points, and 3D-GNOME simulates the structure and provides a convenient user interface for further analysis. Alternatively, a user may generate structures using published ChIA-PET data for the GM12878 cell line by simply specifying a genomic region of interest. 3D-GNOME is freely available at http://3dgnome.cent.uw.edu.pl/.
3D-GNOME: an integrated web service for structural modeling of the 3D genome
Szalaj, Przemyslaw; Michalski, Paul J.; Wróblewski, Przemysław; Tang, Zhonghui; Kadlof, Michal; Mazzocco, Giovanni; Ruan, Yijun; Plewczynski, Dariusz
2016-01-01
Recent advances in high-throughput chromosome conformation capture (3C) technology, such as Hi-C and ChIA-PET, have demonstrated the importance of 3D genome organization in development, cell differentiation and transcriptional regulation. There is now a widespread need for computational tools to generate and analyze 3D structural models from 3C data. Here we introduce our 3D GeNOme Modeling Engine (3D-GNOME), a web service which generates 3D structures from 3C data and provides tools to visually inspect and annotate the resulting structures, in addition to a variety of statistical plots and heatmaps which characterize the selected genomic region. Users submit a bedpe (paired-end BED format) file containing the locations and strengths of long range contact points, and 3D-GNOME simulates the structure and provides a convenient user interface for further analysis. Alternatively, a user may generate structures using published ChIA-PET data for the GM12878 cell line by simply specifying a genomic region of interest. 3D-GNOME is freely available at http://3dgnome.cent.uw.edu.pl/. PMID:27185892
3D fast wavelet network model-assisted 3D face recognition
NASA Astrophysics Data System (ADS)
Said, Salwa; Jemai, Olfa; Zaied, Mourad; Ben Amar, Chokri
2015-12-01
In last years, the emergence of 3D shape in face recognition is due to its robustness to pose and illumination changes. These attractive benefits are not all the challenges to achieve satisfactory recognition rate. Other challenges such as facial expressions and computing time of matching algorithms remain to be explored. In this context, we propose our 3D face recognition approach using 3D wavelet networks. Our approach contains two stages: learning stage and recognition stage. For the training we propose a novel algorithm based on 3D fast wavelet transform. From 3D coordinates of the face (x,y,z), we proceed to voxelization to get a 3D volume which will be decomposed by 3D fast wavelet transform and modeled after that with a wavelet network, then their associated weights are considered as vector features to represent each training face . For the recognition stage, an unknown identity face is projected on all the training WN to obtain a new vector features after every projection. A similarity score is computed between the old and the obtained vector features. To show the efficiency of our approach, experimental results were performed on all the FRGC v.2 benchmark.
A 3-D shape model of Interamnia
NASA Astrophysics Data System (ADS)
Sato, Isao
2015-08-01
A 3-D shape model of the sixth largest of the main belt asteroids, (704) Interamnia, is presented. The model is reproduced from its two stellar occultation observations and six lightcurves between 1969 and 2011. The first stellar occultation was the occultation of TYC 234500183 on 1996 December 17 observed from 13 sites in the USA. An elliptical cross section of (344.6±9.6km)×(306.2±9.1km), for position angle P=73.4±12.5 was fitted. The lightcurve around the occultation shows that the peak-to-peak amplitude was 0.04 mag. and the occultation phase was just before the minimum. The second stellar occultation was the occultation of HIP 036189 on 2003 March 23 observed from 39 sites in Japan and Hawaii. An elliptical cross section of (349.8±0.9km)×(303.7±1.7km), for position angle P=86.0±1.1 was fitted. A companion of 8.5 mag. of the occulted star was discovered whose separation is 12±2 mas (milli-arcseconds), P=148±11 . A combined analysis of rotational lightcurves and occultation chords can return more information than can be obtained with either technique alone. From follow-up photometric observations of the asteroid between 2003 and 2011, its rotation period is determined to be 8.728967167±0.00000007 hours, which is accurate enough to fix the rotation phases at other occultation events. The derived north pole is λ2000=259±8, β2000=-50±5 (retrograde rotation); the lengths of the three principal axes are 2a=361.8±2.8km, 2b=324.4±5.0km, 2c=297.3±3.5km, and the mean diameter is D=326.8±3.0km. Supposing the mass of Interamnia as (3.5±0.9)×10-11 solar masses, the density is then ρ=3.8±1.0 g cm-3.
Anatomy-based 3D skeleton extraction from femur model.
Gharenazifam, Mina; Arbabi, Ehsan
2014-11-01
Using 3D models of bones can highly improve accuracy and reliability of orthopaedic evaluation. However, it may impose excessive computational load. This article proposes a fully automatic method for extracting a compact model of the femur from its 3D model. The proposed method works by extracting a 3D skeleton based on the clinical parameters of the femur. Therefore, in addition to summarizing a 3D model of the bone, the extracted skeleton would preserve important clinical and anatomical information. The proposed method has been applied on 3D models of 10 femurs and the results have been evaluated for different resolutions of data.
3D structure and conductive thermal field of the Upper Rhine Graben
NASA Astrophysics Data System (ADS)
Freymark, Jessica; Sippel, Judith; Scheck-Wenderoth, Magdalena; Bär, Kristian; Stiller, Manfred; Fritsche, Johann-Gerhard; Kracht, Matthias
2016-04-01
The Upper Rhine Graben (URG) was formed as part of the European Cenozoic Rift System in a complex extensional setting. At present-day, it has a large socioeconomic relevance as it provides a great potential for geothermal energy production in Germany and France. For the utilisation of this energy resource it is crucial to understand the structure and the observed temperature anomalies in the rift basin. In the framework of the EU-funded "IMAGE" project (Integrated Methods for Advanced Geothermal Exploration), we apply a data-driven numerical modelling approach to quantify the processes and properties controlling the spatial distribution of subsurface temperatures. Typically, reservoir-scale numerical models are developed for predictions on the subsurface hydrothermal conditions and for reducing the risk of drilling non-productive geothermal wells. One major problem related to such models is setting appropriate boundary conditions that define, for instance, how much heat enters the reservoir from greater depths. Therefore, we first build a regional lithospheric-scale 3D structural model, which covers not only the entire URG but also adjacent geological features like the Black Forest and the Vosges Mountains. In particular, we use a multidisciplinary dataset (e.g. well data, seismic reflection data, existing structural models, gravity) to construct the geometries of the sediments, the crust and the lithospheric mantle that control the spatial distribution of thermal conductivity and radiogenic heat production and hence temperatures. By applying a data-based and lithology-dependent parameterisation of this lithospheric-scale 3D structural model and a 3D finite element method, we calculate the steady-state conductive thermal field for the entire region. Available measured temperatures (down to depths of up to 5 km) are considered to validate the 3D thermal model. We present major characteristics of the lithospheric-scale 3D structural model and results of the 3D
Towards a 3d Spatial Urban Energy Modelling Approach
NASA Astrophysics Data System (ADS)
Bahu, J.-M.; Koch, A.; Kremers, E.; Murshed, S. M.
2013-09-01
Today's needs to reduce the environmental impact of energy use impose dramatic changes for energy infrastructure and existing demand patterns (e.g. buildings) corresponding to their specific context. In addition, future energy systems are expected to integrate a considerable share of fluctuating power sources and equally a high share of distributed generation of electricity. Energy system models capable of describing such future systems and allowing the simulation of the impact of these developments thus require a spatial representation in order to reflect the local context and the boundary conditions. This paper describes two recent research approaches developed at EIFER in the fields of (a) geo-localised simulation of heat energy demand in cities based on 3D morphological data and (b) spatially explicit Agent-Based Models (ABM) for the simulation of smart grids. 3D city models were used to assess solar potential and heat energy demand of residential buildings which enable cities to target the building refurbishment potentials. Distributed energy systems require innovative modelling techniques where individual components are represented and can interact. With this approach, several smart grid demonstrators were simulated, where heterogeneous models are spatially represented. Coupling 3D geodata with energy system ABMs holds different advantages for both approaches. On one hand, energy system models can be enhanced with high resolution data from 3D city models and their semantic relations. Furthermore, they allow for spatial analysis and visualisation of the results, with emphasis on spatially and structurally correlations among the different layers (e.g. infrastructure, buildings, administrative zones) to provide an integrated approach. On the other hand, 3D models can benefit from more detailed system description of energy infrastructure, representing dynamic phenomena and high resolution models for energy use at component level. The proposed modelling strategies
3D Modeling Techniques for Print and Digital Media
NASA Astrophysics Data System (ADS)
Stephens, Megan Ashley
In developing my thesis, I looked to gain skills using ZBrush to create 3D models, 3D scanning, and 3D printing. The models created compared the hearts of several vertebrates and were intended for students attending Comparative Vertebrate Anatomy. I used several resources to create a model of the human heart and was able to work from life while creating heart models from other vertebrates. I successfully learned ZBrush and 3D scanning, and successfully printed 3D heart models. ZBrush allowed me to create several intricate models for use in both animation and print media. The 3D scanning technique did not fit my needs for the project, but may be of use for later projects. I was able to 3D print using two different techniques as well.
Cookoff Response of PBXN-109: Material Characterization and ALE3D Thermal Predictions
McClelland, M A; Tran, T D; Cunningham, B J; Weese, R K; Maienschein, J L
2001-08-21
Materials properties measurements are made for the RDX-based explosive, PBXN-109, and initial ALE3D model predictions are given for the cookoff temperature in a U.S. Navy test. This work is part of an effort in the U.S. Navy and Department of Energy (DOE) laboratories to understand the thermal explosion behavior of this material. Benchmark cookoff experiments are being performed by the U.S. Navy to validate DOE materials models and computer codes. The ALE3D computer code can model the coupled thermal, mechanical, and chemical behavior of heating, ignition, and explosion in cookoff tests. In our application, a standard three-step step model is selected for the chemical kinetics. The strength behavior of the solid constituents is represented by a Steinberg-Guinan model while polynomial and gamma-law expressions are used for the Equation Of State (EOS) for the solid and gas species, respectively. Materials characterization measurements are given for thermal expansion, heat capacity, shear modulus, bulk modulus, and One-Dimensional-Time-to-Explosion (ODTX). These measurements and those of the other project participants are used to determine parameters in the ALE3D chemical, mechanical, and thermal models. Time-dependent, two-dimensional results are given for the temperature and material expansion. The results show predicted cookoff temperatures slightly higher than the measured values.
Cookoff Response of PBXN-109: Material Characterization and ALE3D Thermal Predictions
McClelland, M A; Tran, T D; Cunningham, B J; Weese, R K; Maienschein, J L
2001-05-29
Materials properties measurements are made for the RDX-based explosive, PBXN-109, and initial ALE3D model predictions are given for the cookoff temperature in a U.S. Navy test. This work is part of an effort in the U.S. Navy and Department of Energy (DOE) laboratories to understand the thermal explosion behavior of this material. Benchmark cookoff experiments are being performed by the U.S. Navy to validate DOE materials models and computer codes. The ALE3D computer code can model the coupled thermal, mechanical, and chemical behavior of heating, ignition, and explosion in cookoff tests. In our application, a standard three-step step model is selected for the chemical kinetics. The strength behavior of the solid constituents is represented by a Steinberg-Guinan model while polynomial and gamma-law expressions are used for the Equation Of State (EOS) for the solid and gas species, respectively. Materials characterization measurements are given for thermal expansion, heat capacity, shear modulus, bulk modulus, and One-Dimensional-Time-to-Explosion (ODTX). These measurements and those of the other project participants are used to determine parameters in the ALE3D chemical, mechanical, and thermal models. Time-dependent, two-dimensional results are given for the temperature and material expansion. The results show predicted cookoff temperatures slightly higher than the measured values.
Elastic wave modelling in 3D heterogeneous media: 3D grid method
NASA Astrophysics Data System (ADS)
Jianfeng, Zhang; Tielin, Liu
2002-09-01
We present a new numerical technique for elastic wave modelling in 3D heterogeneous media with surface topography, which is called the 3D grid method in this paper. This work is an extension of the 2D grid method that models P-SV wave propagation in 2D heterogeneous media. Similar to the finite-element method in the discretization of a numerical mesh, the proposed scheme is flexible in incorporating surface topography and curved interfaces; moreover it satisfies the free-surface boundary conditions of 3D topography naturally. The algorithm, developed from a parsimonious staggered-grid scheme, solves the problem using integral equilibrium around each node, instead of satisfying elastodynamic differential equations at each node as in the conventional finite-difference method. The computational cost and memory requirements for the proposed scheme are approximately the same as those used by the same order finite-difference method. In this paper, a mixed tetrahedral and parallelepiped grid method is presented; and the numerical dispersion and stability criteria on the tetrahedral grid method and parallelepiped grid method are discussed in detail. The proposed scheme is successfully tested against an analytical solution for the 3D Lamb problem and a solution of the boundary method for the diffraction of a hemispherical crater. Moreover, examples of surface-wave propagation in an elastic half-space with a semi-cylindrical trench on the surface and 3D plane-layered model are presented.
The 3D rocket combustor acoustics model
NASA Technical Reports Server (NTRS)
Priem, Richard J.; Breisacher, Kevin J.
1992-01-01
The theory and procedures for determining the characteristics of pressure oscillations in rocket engines with prescribed burning rate oscillations are presented. Analyses including radial and hub baffles and absorbers can be performed in one, two, and three dimensions. Pressure and velocity oscillations calculated using this procedure are presented for the SSME to show the influence of baffles and absorbers on the burning rate oscillations required to achieve neutral stability. Comparisons are made between the results obtained utilizing 1-D, 2-D, and 3-D assumptions with regards to capturing the physical phenomena of interest and computational requirements.
3D modeling based on CityEngine
NASA Astrophysics Data System (ADS)
Jia, Guangyin; Liao, Kaiju
2017-03-01
Currently, there are many 3D modeling softwares, like 3DMAX, AUTOCAD, and more populous BIM softwares represented by REVIT. CityEngine modeling software introduced in this paper can fully utilize the existing GIS data and combine other built models to make 3D modeling on internal and external part of buildings in a rapid and batch manner, so as to improve the 3D modeling efficiency.
Single-Tooth Modeling for 3D Dental Model
Yuan, Tianran; Liao, Wenhe; Dai, Ning; Cheng, Xiaosheng; Yu, Qing
2010-01-01
An integrated single-tooth modeling scheme is proposed for the 3D dental model acquired by optical digitizers. The cores of the modeling scheme are fusion regions extraction, single tooth shape restoration, and single tooth separation. According to the “valley” shape-like characters of the fusion regions between two adjoining teeth, the regions of the 3D dental model are analyzed and classified based on the minimum curvatures of the surface. The single tooth shape is restored according to the bioinformation along the hole boundary, which is generated after the fusion region being removed. By using the extracted boundary from the blending regions between the teeth and soft tissues as reference, the teeth can be separated from the 3D dental model one by one correctly. Experimental results show that the proposed method can achieve satisfying modeling results with high-degree approximation of the real tooth and meet the requirements of clinical oral medicine. PMID:20689718
3D tumor models: history, advances and future perspectives.
Benien, Parul; Swami, Archana
2014-05-01
Evaluation of cancer therapeutics by utilizing 3D tumor models, before clinical studies, could be more advantageous than conventional 2D tumor models (monolayer cultures). The 3D systems mimic the tumor microenvironment more closely than 2D systems. The following review discusses the various 3D tumor models present today with the advantages and limitations of each. 3D tumor models replicate the elements of a tumor microenvironment such as hypoxia, necrosis, angiogenesis and cell adhesion. The review introduces application of techniques such as microfluidics, imaging and tissue engineering to improve the 3D tumor models. Despite their tremendous potential to better screen chemotherapeutics, 3D tumor models still have a long way to go before they are used commonly as in vitro tumor models in pharmaceutical industrial research.
NASA Astrophysics Data System (ADS)
Min, M.; Dullemond, C. P.; Kama, M.; Dominik, C.
2011-03-01
The precise location of the water ice condensation front (‘snow line’) in the protosolar nebula has been a debate for a long time. Its importance stems from the expected substantial jump in the abundance of solids beyond the snow line, which is conducive to planet formation, and from the higher ‘stickiness’ in collisions of ice-coated dust grains, which may help the process of coagulation of dust and the formation of planetesimals. In an optically thin nebula, the location of the snow line is easily calculated to be around 3 AU, subject to brightness variations of the young Sun. However, in its first 5-10 myr, the solar nebula was optically thick, implying a smaller snowline radius due to shielding from direct sunlight, but also a larger radius because of viscous heating. Several models have attempted to treat these opposing effects. However, until recently treatments beyond an approximate 1 + 1D radiative transfer were unfeasible. We revisit the problem with a fully self-consistent 3D treatment in an axisymmetric disk model, including a density-dependent treatment of the dust and ice sublimation. We find that the location of the snow line is very sensitive to the opacities of the dust grains and the mass accretion rate of the disk. We show that previous approximate treatments are quite efficient at determining the location of the snow line if the energy budget is locally dominated by viscous accretion. Using this result we derive an analytic estimate of the location of the snow line that compares very well with results from this and previous studies. Using solar abundances of the elements we compute the abundance of dust and ice and find that the expected jump in solid surface density at the snow line is smaller than previously assumed. We further show that in the inner few AU the refractory species are also partly evaporated, leading to a significantly smaller solid state surface density in the regions where the rocky planets were formed.
Investigation of surface wave amplitudes in 3-D velocity and 3-D Q models
NASA Astrophysics Data System (ADS)
Ruan, Y.; Zhou, Y.
2010-12-01
It has been long recognized that seismic amplitudes depend on both wave speed structures and anelasticity (Q) structures. However, the effects of lateral heterogeneities in wave speed and Q structures on seismic amplitudes has not been well understood. We investigate the effects of 3-D wave speed and 3-D anelasticity (Q) structures on surface-wave amplitudes based upon wave propagation simulations of twelve globally-distributed earthquakes and 801 stations in Earth models with and without lateral heterogeneities in wave speed and anelasticity using a Spectral Element Method (SEM). Our tomographic-like 3-D Q models are converted from a velocity model S20RTS using a set of reasonable mineralogical parameters, assuming lateral perturbations in both velocity and Q are due to temperature perturbations. Surface-wave amplitude variations of SEM seismograms are measured in the period range of 50--200 s using boxcar taper, cosine taper and Slepian multi-tapers. We calculate ray-theoretical predictions of surface-wave amplitude perturbations due to elastic focusing, attenuation, and anelastic focusing which respectively depend upon the second spatial derivative (''roughness'') of perturbations in phase velocity, 1/Q, and the roughness of perturbations in 1/Q. Both numerical experiments and theoretical calculations show that (1) for short-period (~ 50 s) surface waves, the effects of amplitude attenuation due to 3-D Q structures are comparable with elastic focusing effects due to 3-D wave speed structures; and (2) for long-period (> 100 s) surface waves, the effects of attenuation become much weaker than elastic focusing; and (3) elastic focusing effects are correlated with anelastic focusing at all periods due to the correlation between velocity and Q models; and (4) amplitude perturbations are depend on measurement techniques and therefore cannot be directly compared with ray-theoretical predictions because ray theory does not account for the effects of measurement
DYNA3D Material Model 71 - Solid Element Test Problem
Zywicz, E
2008-01-24
A general phenomenological-based elasto-plastic nonlinear isotropic strain hardening material model was implemented in DYNA3D for use in solid, beam, truss, and shell elements. The constitutive model, Model 71, is based upon conventional J2 plasticity and affords optional temperature and rate dependence (visco-plasticity). The expressions for strain hardening, temperature dependence, and rate dependence allow it to represent a wide variety of material responses. Options to capture temperature changes due to adiabatic heating and thermal straining are incorporated into the constitutive framework as well. The verification problem developed for this constitutive model consists of four uni-axial right cylinders subject to constant true strain-rate boundary conditions. Three of the specimens have different constant strain rates imposed, while the fourth specimen is subjected to several strain rate jumps. The material parameters developed by Fehlmann (2005) for 21-6-9 Nitronic steel are utilized. As demonstrated below, the finite element (FE) simulations are in excellent agreement with the theoretical responses and indicated the model is functioning as desired. Consequently, this problem serves as both a verification problem and regression test problem for DYNA3D.
3D Face modeling using the multi-deformable method.
Hwang, Jinkyu; Yu, Sunjin; Kim, Joongrock; Lee, Sangyoun
2012-09-25
In this paper, we focus on the problem of the accuracy performance of 3D face modeling techniques using corresponding features in multiple views, which is quite sensitive to feature extraction errors. To solve the problem, we adopt a statistical model-based 3D face modeling approach in a mirror system consisting of two mirrors and a camera. The overall procedure of our 3D facial modeling method has two primary steps: 3D facial shape estimation using a multiple 3D face deformable model and texture mapping using seamless cloning that is a type of gradient-domain blending. To evaluate our method's performance, we generate 3D faces of 30 individuals and then carry out two tests: accuracy test and robustness test. Our method shows not only highly accurate 3D face shape results when compared with the ground truth, but also robustness to feature extraction errors. Moreover, 3D face rendering results intuitively show that our method is more robust to feature extraction errors than other 3D face modeling methods. An additional contribution of our method is that a wide range of face textures can be acquired by the mirror system. By using this texture map, we generate realistic 3D face for individuals at the end of the paper.
Ui, Atsushi; Miyaji, Takamasa
2004-10-15
The best-estimate coupled three-dimensional (3-D) core and thermal-hydraulic code system TRAC-BF1/COS3D has been developed. COS3D, based on a modified one-group neutronic model, is a 3-D core simulator used for licensing analyses and core management of commercial boiling water reactor (BWR) plants in Japan. TRAC-BF1 is a plant simulator based on a two-fluid model. TRAC-BF1/COS3D is a coupled system of both codes, which are connected using a parallel computing tool. This code system was applied to the OECD/NRC BWR Turbine Trip Benchmark. Since the two-group cross-section tables are provided by the benchmark team, COS3D was modified to apply to this specification. Three best-estimate scenarios and four hypothetical scenarios were calculated using this code system. In the best-estimate scenario, the predicted core power with TRAC-BF1/COS3D is slightly underestimated compared with the measured data. The reason seems to be a slight difference in the core boundary conditions, that is, pressure changes and the core inlet flow distribution, because the peak in this analysis is sensitive to them. However, the results of this benchmark analysis show that TRAC-BF1/COS3D gives good precision for the prediction of the actual BWR transient behavior on the whole. Furthermore, the results with the modified one-group model and the two-group model were compared to verify the application of the modified one-group model to this benchmark. This comparison shows that the results of the modified one-group model are appropriate and sufficiently precise.
NASA Astrophysics Data System (ADS)
Maesano, Francesco E.; D'Ambrogi, Chiara
2017-02-01
We present Vel-IO 3D, a tool for 3D velocity model creation and time-depth conversion, as part of a workflow for 3D model building. The workflow addresses the management of large subsurface dataset, mainly seismic lines and well logs, and the construction of a 3D velocity model able to describe the variation of the velocity parameters related to strong facies and thickness variability and to high structural complexity. Although it is applicable in many geological contexts (e.g. foreland basins, large intermountain basins), it is particularly suitable in wide flat regions, where subsurface structures have no surface expression. The Vel-IO 3D tool is composed by three scripts, written in Python 2.7.11, that automate i) the 3D instantaneous velocity model building, ii) the velocity model optimization, iii) the time-depth conversion. They determine a 3D geological model that is consistent with the primary geological constraints (e.g. depth of the markers on wells). The proposed workflow and the Vel-IO 3D tool have been tested, during the EU funded Project GeoMol, by the construction of the 3D geological model of a flat region, 5700 km2 in area, located in the central part of the Po Plain. The final 3D model showed the efficiency of the workflow and Vel-IO 3D tool in the management of large amount of data both in time and depth domain. A 4 layer-cake velocity model has been applied to a several thousand (5000-13,000 m) thick succession, with 15 horizons from Triassic up to Pleistocene, complicated by a Mesozoic extensional tectonics and by buried thrusts related to Southern Alps and Northern Apennines.
NASA Astrophysics Data System (ADS)
Ciardi, A.; Chittenden, J. P.; Lebedev, S. V.; Bland, S. N.; Jennings, C. A.
2003-10-01
X-pinch produced plasmas are an intense source of soft x-rays generated by passing a large, fast rising current through two or more thin metallic wires crossed in the shape of <93>an "X". During the current pulse, the plasma is pinched at the crossing point where a dense Z-pinch plasma column develops. Further compression produces micron sized x-ray hot spots with energy densities in excess of ˜10^24 eV cm-3. We present 3D resistive magnetohydrodynamic simulations of two- and four-wire X-pinches for a variety of wire materials. The simulations naturally follow the evolution of the X-pinch: jet-like structures on axis, formation of a Z-pinch and its subsequent rapid evolution and production of x-ray hot spots. The effects of wire material and wire number are studied with particular consideration to the relationship between the magnetic confinement and radiative cooling mechanisms, which ultimately determine the complex behaviour of the X-pinch.
Modeling moving systems with RELAP5-3D
Mesina, G. L.; Aumiller, David L.; Buschman, Francis X.; Kyle, Matt R.
2015-12-04
RELAP5-3D is typically used to model stationary, land-based reactors. However, it can also model reactors in other inertial and accelerating frames of reference. By changing the magnitude of the gravitational vector through user input, RELAP5-3D can model reactors on a space station or the moon. The field equations have also been modified to model reactors in a non-inertial frame, such as occur in land-based reactors during earthquakes or onboard spacecraft. Transient body forces affect fluid flow in thermal-fluid machinery aboard accelerating crafts during rotational and translational accelerations. It is useful to express the equations of fluid motion in the accelerating frame of reference attached to the moving craft. However, careful treatment of the rotational and translational kinematics is required to accurately capture the physics of the fluid motion. Correlations for flow at angles between horizontal and vertical are generated via interpolation where no experimental studies or data exist. The equations for three-dimensional fluid motion in a non-inertial frame of reference are developed. As a result, two different systems for describing rotational motion are presented, user input is discussed, and an example is given.
Modeling moving systems with RELAP5-3D
Mesina, G. L.; Aumiller, David L.; Buschman, Francis X.; ...
2015-12-04
RELAP5-3D is typically used to model stationary, land-based reactors. However, it can also model reactors in other inertial and accelerating frames of reference. By changing the magnitude of the gravitational vector through user input, RELAP5-3D can model reactors on a space station or the moon. The field equations have also been modified to model reactors in a non-inertial frame, such as occur in land-based reactors during earthquakes or onboard spacecraft. Transient body forces affect fluid flow in thermal-fluid machinery aboard accelerating crafts during rotational and translational accelerations. It is useful to express the equations of fluid motion in the acceleratingmore » frame of reference attached to the moving craft. However, careful treatment of the rotational and translational kinematics is required to accurately capture the physics of the fluid motion. Correlations for flow at angles between horizontal and vertical are generated via interpolation where no experimental studies or data exist. The equations for three-dimensional fluid motion in a non-inertial frame of reference are developed. As a result, two different systems for describing rotational motion are presented, user input is discussed, and an example is given.« less
Comparing a quasi-3D to a full 3D nearshore circulation model: SHORECIRC and ROMS
Haas, K.A.; Warner, J.C.
2009-01-01
Predictions of nearshore and surf zone processes are important for determining coastal circulation, impacts of storms, navigation, and recreational safety. Numerical modeling of these systems facilitates advancements in our understanding of coastal changes and can provide predictive capabilities for resource managers. There exists many nearshore coastal circulation models, however they are mostly limited or typically only applied as depth integrated models. SHORECIRC is an established surf zone circulation model that is quasi-3D to allow the effect of the variability in the vertical structure of the currents while maintaining the computational advantage of a 2DH model. Here we compare SHORECIRC to ROMS, a fully 3D ocean circulation model which now includes a three dimensional formulation for the wave-driven flows. We compare the models with three different test applications for: (i) spectral waves approaching a plane beach with an oblique angle of incidence; (ii) monochromatic waves driving longshore currents in a laboratory basin; and (iii) monochromatic waves on a barred beach with rip channels in a laboratory basin. Results identify that the models are very similar for the depth integrated flows and qualitatively consistent for the vertically varying components. The differences are primarily the result of the vertically varying radiation stress utilized by ROMS and the utilization of long wave theory for the radiation stress formulation in vertical varying momentum balance by SHORECIRC. The quasi-3D model is faster, however the applicability of the fully 3D model allows it to extend over a broader range of processes, temporal, and spatial scales. ?? 2008 Elsevier Ltd.
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.
Visualization of 3D Geological Models on Google Earth
NASA Astrophysics Data System (ADS)
Choi, Y.; Um, J.; Park, M.
2013-05-01
Google Earth combines satellite imagery, aerial photography, thematic maps and various data sets to make a three-dimensional (3D) interactive image of the world. Currently, Google Earth is a popular visualization tool in a variety of fields and plays an increasingly important role not only for private users in daily life, but also for scientists, practitioners, policymakers and stakeholders in research and application. In this study, a method to visualize 3D geological models on Google Earth is presented. COLLAborative Design Activity (COLLADA, an open standard XML schema for establishing interactive 3D applications) was used to represent different 3D geological models such as borehole, fence section, surface-based 3D volume and 3D grid by triangle meshes (a set of triangles connected by their common edges or corners). In addition, we designed Keyhole Markup Language (KML, the XML-based scripting language of Google Earth) codes to import the COLLADA files into the 3D render window of Google Earth. The method was applied to the Grosmont formation in Alberta, Canada. The application showed that the combination of COLLADA and KML enables Google Earth to effectively visualize 3D geological structures and properties.; Visualization of the (a) boreholes, (b) fence sections, (c) 3D volume model and (d) 3D grid model of Grossmont formation on Google Earth
A 3D Geometry Model Search Engine to Support Learning
ERIC Educational Resources Information Center
Tam, Gary K. L.; Lau, Rynson W. H.; Zhao, Jianmin
2009-01-01
Due to the popularity of 3D graphics in animation and games, usage of 3D geometry deformable models increases dramatically. Despite their growing importance, these models are difficult and time consuming to build. A distance learning system for the construction of these models could greatly facilitate students to learn and practice at different…
[Potentials of 3D-modeling in reconstructive orbital surgery].
Butsan, S B; Khokhlachev, S B; Ĭigitaliev, Sh N; Zaiakin, Ia A
2012-01-01
A technique of bone reconstructive surgery of orbitofrontonasomalar region using 3D-modeling based on multispiral computer tomography data is presented. The efficacy of intraoperative templates created using 3D-modeling was showed for harvesting and modeling of bone calvarial autografts. The steps of reconstructive procedure are explained in details for repair of medial and inferior orbital fractures.
Measurement of Laser Weld Temperatures for 3D Model Input
Dagel, Daryl; Grossetete, Grant; Maccallum, Danny O.
2016-10-01
Laser welding is a key joining process used extensively in the manufacture and assembly of critical components for several weapons systems. Sandia National Laboratories advances the understanding of the laser welding process through coupled experimentation and modeling. This report summarizes the experimental portion of the research program, which focused on measuring temperatures and thermal history of laser welds on steel plates. To increase confidence in measurement accuracy, researchers utilized multiple complementary techniques to acquire temperatures during laser welding. This data serves as input to and validation of 3D laser welding models aimed at predicting microstructure and the formation of defects and their impact on weld-joint reliability, a crucial step in rapid prototyping of weapons components.
3D neutronic/thermal-hydraulic coupled analysis of MYRRHA
Vazquez, M.; Martin-Fuertes, F.
2012-07-01
The current tendency in multiphysics calculations applied to reactor physics is the use of already validated computer codes, coupled by means of an iterative approach. In this paper such an approach is explained concerning neutronics and thermal-hydraulics coupled analysis with MCNPX and COBRA-IV codes using a driver program and file exchange between codes. MCNPX provides the neutronic analysis of heterogeneous nuclear systems, both in critical and subcritical states, while COBRA-IV is a subchannel code that can be used for rod bundles or core thermal-hydraulics analysis. In our model, the MCNP temperature dependence of nuclear data is handled via pseudo-material approach, mixing pre-generated cross section data set to obtain the material with the desired cross section temperature. On the other hand, COBRA-IV has been updated to allow for the simulation of liquid metal cooled reactors. The coupled computational tool can be applied to any geometry and coolant, as it is the case of single fuel assembly, at pin-by-pin level, or full core simulation with the average pin of each fuel-assembly. The coupling tool has been applied to the critical core layout of the SCK-CEN MYRRHA concept, an experimental LBE cooled fast reactor presently in engineering design stage. (authors)
Computational modeling of RNA 3D structures and interactions.
Dawson, Wayne K; Bujnicki, Janusz M
2016-04-01
RNA molecules have key functions in cellular processes beyond being carriers of protein-coding information. These functions are often dependent on the ability to form complex three-dimensional (3D) structures. However, experimental determination of RNA 3D structures is difficult, which has prompted the development of computational methods for structure prediction from sequence. Recent progress in 3D structure modeling of RNA and emerging approaches for predicting RNA interactions with ions, ligands and proteins have been stimulated by successes in protein 3D structure modeling.
San Francisco Bay test case for 3-D model verification
Smith, Peter E.
1994-01-01
This paper describes a field test case for 3-D hydrodynamic model verification using data from Carquinez Strait in San Francisco Bay, California. It will be disseminated by the ASCE Computational Hydraulics task committee on 3-D Free-Surface Hydrodynamic Model Verifications during late 1994.
An Automatic Registration Algorithm for 3D Maxillofacial Model
NASA Astrophysics Data System (ADS)
Qiu, Luwen; Zhou, Zhongwei; Guo, Jixiang; Lv, Jiancheng
2016-09-01
3D image registration aims at aligning two 3D data sets in a common coordinate system, which has been widely used in computer vision, pattern recognition and computer assisted surgery. One challenging problem in 3D registration is that point-wise correspondences between two point sets are often unknown apriori. In this work, we develop an automatic algorithm for 3D maxillofacial models registration including facial surface model and skull model. Our proposed registration algorithm can achieve a good alignment result between partial and whole maxillofacial model in spite of ambiguous matching, which has a potential application in the oral and maxillofacial reparative and reconstructive surgery. The proposed algorithm includes three steps: (1) 3D-SIFT features extraction and FPFH descriptors construction; (2) feature matching using SAC-IA; (3) coarse rigid alignment and refinement by ICP. Experiments on facial surfaces and mandible skull models demonstrate the efficiency and robustness of our algorithm.
Interactive mapping on 3-D terrain models
NASA Astrophysics Data System (ADS)
Bernardin, T.; Cowgill, E.; Gold, R.; Hamann, B.; Kreylos, O.; Schmitt, A.
2006-10-01
We present an interactive, real-time mapping system for use with digital elevation models and remotely sensed multispectral imagery that aids geoscientists in the creation and interpretation of geologic/neotectonic maps at length scales of 10 m to 1000 km. Our system provides a terrain visualization of the surface of the Earth or other terrestrial planets by displaying a virtual terrain model generated from a digital elevation model overlain by a color texture generated from orthophotos or satellite imagery. We use a quadtree-based, multiresolution display method to render in real time high-resolution virtual terrain models that span large spatial regions. The system allows users to measure the orientations of geologic surfaces and record their observations by drawing lines directly on the virtual terrain model. In addition, interpretive surfaces can be generated from these drawings and displayed to facilitate understanding of the three-dimensional geometry of geologic surfaces. The main strength of our system is the combination of real-time rendering and interactive mapping performed directly on the virtual terrain model with the ability to navigate the scene while changing viewpoints arbitrarily during mapping. User studies and comparisons with commercially available mapping software show that our system improves mapping accuracy and efficiency and also yields observations that cannot be made with existing systems.
NASA Astrophysics Data System (ADS)
Malinauskas, Mangirdas; Lukoševičius, Laurynas; MackevičiÅ«tÄ--, DovilÄ--; BalčiÅ«nas, Evaldas; RekštytÄ--, Sima; Paipulas, Domas
2014-05-01
A novel approach for efficient manufacturing of three-dimensional (3D) microstructured scaffolds designed for cell studies and tissue engineering applications is presented. A thermal extrusion (fused filament fabrication) 3D printer is employed as a simple and low-cost tabletop device enabling rapid materialization of CAD models out of biocompatible and biodegradable polylactic acid (PLA). Here it was used to produce cm- scale microporous (pore size varying from 100 to 400 µm) scaffolds. The fabricated objects were further laser processed in a direct laser writing (DLW) subtractive (ablation) and additive (lithography) manners. The first approach enables precise surface modification by creating micro-craters, holes and grooves thus increasing the surface roughness. An alternative way is to immerse the 3D PLA scaffold in a monomer solution and use the same DLW setup to refine its inner structure by fabricating dots, lines or a fine mesh on top as well as inside the pores of previously produced scaffolds. The DLW technique is empowered by ultrafast lasers - it allows 3D structuring with high spatial resolution in a great variety of photosensitive materials. Structure geometry on macro- to micro- scales could be finely tuned by combining these two fabrication techniques. Such artificial 3D substrates could be used for cell growth or as biocompatible-biodegradable implants. This combination of distinct material processing techniques enables rapid fabrication of diverse functional micro- featured and integrated devices. Hopefully, the proposed approach will find numerous applications in the field of ms, microfluidics, microoptics and many others.
3-D model-based Bayesian classification
Soenneland, L.; Tenneboe, P.; Gehrmann, T.; Yrke, O.
1994-12-31
The challenging task of the interpreter is to integrate different pieces of information and combine them into an earth model. The sophistication level of this earth model might vary from the simplest geometrical description to the most complex set of reservoir parameters related to the geometrical description. Obviously the sophistication level also depend on the completeness of the available information. The authors describe the interpreter`s task as a mapping between the observation space and the model space. The information available to the interpreter exists in observation space and the task is to infer a model in model-space. It is well-known that this inversion problem is non-unique. Therefore any attempt to find a solution depend son constraints being added in some manner. The solution will obviously depend on which constraints are introduced and it would be desirable to allow the interpreter to modify the constraints in a problem-dependent manner. They will present a probabilistic framework that gives the interpreter the tools to integrate the different types of information and produce constrained solutions. The constraints can be adapted to the problem at hand.
Extending 3D city models with legal information
NASA Astrophysics Data System (ADS)
Frank, A. U.; Fuhrmann, T.; Navratil, G.
2012-10-01
3D city models represent existing physical objects and their topological and functional relations. In everyday life the rights and responsibilities connected to these objects, primarily legally defined rights and obligations but also other socially and culturally established rights, are of importance. The rights and obligations are defined in various laws and it is often difficult to identify the rules applicable for a certain case. The existing 2D cadastres show civil law rights and obligations and plans to extend them to provide information about public law restrictions for land use are in several countries under way. It is tempting to design extensions to the 3D city models to provide information about legal rights in 3D. The paper analyses the different types of information that are needed to reduce conflicts and to facilitate decisions about land use. We identify the role 3D city models augmented with planning information in 3D can play, but do not advocate a general conversion from 2D to 3D for the legal cadastre. Space is not anisotropic and the up/down dimension is practically very different from the two dimensional plane - this difference must be respected when designing spatial information systems. The conclusions are: (1) continue the current regime for ownership of apartments, which is not ownership of a 3D volume, but co-ownership of a building with exclusive use of some rooms; such exclusive use rights could be shown in a 3D city model; (2) ownership of 3D volumes for complex and unusual building situations can be reported in a 3D city model, but are not required everywhere; (3) indicate restrictions for land use and building in 3D city models, with links to the legal sources.
Opportunity Landing Spot Panorama (3-D Model)
NASA Technical Reports Server (NTRS)
2004-01-01
The rocky outcrop traversed by the Mars Exploration Rover Opportunity is visible in this three-dimensional model of the rover's landing site. Opportunity has acquired close-up images along the way, and scientists are using the rover's instruments to closely examine portions of interest. The white fragments that look crumpled near the center of the image are portions of the airbags. Distant scenery is displayed on a spherical backdrop or 'billboard' for context. Artifacts near the top rim of the crater are a result of the transition between the three-dimensional model and the billboard. Portions of the terrain model lacking sufficient data appear as blank spaces or gaps, colored reddish-brown for better viewing. This image was generated using special software from NASA's Ames Research Center and a mosaic of images taken by the rover's panoramic camera.
[figure removed for brevity, see original site] Click on image for larger view
The rocky outcrop traversed by the Mars Exploration Rover Opportunity is visible in this zoomed-in portion of a three-dimensional model of the rover's landing site. Opportunity has acquired close-up images along the way, and scientists are using the rover's instruments to closely examine portions of interest. The white fragments that look crumpled near the center of the image are portions of the airbags. Distant scenery is displayed on a spherical backdrop or 'billboard' for context. Artifacts near the top rim of the crater are a result of the transition between the three-dimensional model and the billboard. Portions of the terrain model lacking sufficient data appear as blank spaces or gaps, colored reddish-brown for better viewing. This image was generated using special software from NASA's Ames Research Center and a mosaic of images taken by the rover's panoramic camera.
3-D Eutrophication Modeling for Lake Simcoe, Canada
NASA Astrophysics Data System (ADS)
Lu, Q.; Duckett, F.; Nairn, R.; Brunton, A.
2006-12-01
The Lake Simcoe Region Conservation Authority (LSRCA) and the Province of Ontario are undertaking a series of studies to facilitate management of the pressures of population growth in the Lake Simcoe watershed. With rapid population growth and urban development comes additional land clearing, storm water runoff and the discharge of treated sewage, all of which are sources of increased phosphorus loading to Lake Simcoe. Depressed oxygen levels were linked to phosphorous enrichment of the lake, with the resultant stimulation of algal growth in the sunlit upper waters of the lake, and its subsequent senescence and settling into the hypolimnion where bacterial decomposition consumes oxygen from the stratified waters. This poster describes a 3-D hydrodynamic, thermal and water quality model of Lake Simcoe developed using the Danish Hydraulics Institute (DHI) MIKE3 model. The hydrodynamic module includes wind-driven circulation, temperature variation, development of the thermocline and thermal stratification, and hydraulic forcing from inflowing tributaries. This is linked to the water quality module which simulates the eutrophication processes in the response of the lake to loadings of phosphorus, such as algal growth, the growth of aquatic plants and subsequent oxygen consumption. The model has been calibrated against Acoustic Doppler Current Profiler velocity data, plus measured temperature and water quality data at MOE stations in the lake and water intakes. The model is an important assessment tool for the management of the lake and its watersheds, allowing assessment of the impacts of the urban growth and land use change on the water quality in Lake Simcoe.
Venusian Applications of 3D Convection Modeling
NASA Technical Reports Server (NTRS)
Bonaccorso, Timary Annie
2011-01-01
This study models mantle convection on Venus using the 'cubed sphere' code OEDIPUS, which models one-sixth of the planet in spherical geometry. We are attempting to balance internal heating, bottom mantle viscosity, and temperature difference across Venus' mantle, in order to create a realistic model that matches with current planetary observations. We also have begun to run both lower and upper mantle simulations to determine whether layered (as opposed to whole-mantle) convection might produce more efficient heat transfer, as well as to model coronae formation in the upper mantle. Upper mantle simulations are completed using OEDIPUS' Cartesian counterpart, JOCASTA. This summer's central question has been how to define a mantle plume. Traditionally, we have defined a hot plume the region with temperature at or above 40% of the difference between the maximum and horizontally averaged temperature, and a cold plume as the region with 40% of the difference between the minimum and average temperature. For less viscous cases (1020 Pa?s), the plumes generated by that definition lacked vigor, displaying buoyancies 1/100th of those found in previous, higher viscosity simulations (1021 Pa?s). As the mantle plumes with large buoyancy flux are most likely to produce topographic uplift and volcanism, the low viscosity cases' plumes may not produce observable deformation. In an effort to eliminate the smallest plumes, we experimented with different lower bound parameters and temperature percentages.
James E. Fisher; Cliff B. Davis; Walter L. Weaver
2005-06-01
A compressor model has been implemented in the RELAP5-3D© code. The model is similar to that of the existing pump model, and performs the same function on a gas as the pump performs on a single-phase or two-phase fluid. The compressor component consists of an inlet junction and a control volume, and optionally, an outlet junction. This feature permits cascading compressor components in series. The equations describing the physics of the compressor are derived from first principles. These equations are used to obtain the head, the torque, and the energy dissipation. Compressor performance is specified using a map, specific to the design of the machine, in terms of the ratio of outlet-to-inlet total (or stagnation) pressure and adiabatic efficiency as functions of rotational velocity and flow rate. The input quantities are specified in terms of dimensionless variables, which are corrected to stagnation density and stagnation sound speed. A small correction was formulated for the input of efficiency to account for the error introduced by assumption of constant density when integrating the momentum equation. Comparison of the results of steady-state operation of the compressor model to those of the MIT design calculation showed excellent agreement for both pressure ratio and power.
Global Magnetospheric Modeling of 3D Reconnection
NASA Technical Reports Server (NTRS)
Spicer, Daniel S.
1999-01-01
A review of approaches to the global modeling of the terrestrial magnetosphere, how these approaches are utilized to interpret satellite data, and how these approaches have been successful at predicting magnetospheric phenomena will be presented. In addition, the importance of the ionospheric boundary and its effect on the globally topology of the magnetospheric magnetic field will be reviewed. In particular, numerical results that are rapidly changing our view of magnetospheric reconnection within the magnetospheric magnetic field will be discussed.
Modeling 3D facial shape from DNA.
Claes, Peter; Liberton, Denise K; Daniels, Katleen; Rosana, Kerri Matthes; Quillen, Ellen E; Pearson, Laurel N; McEvoy, Brian; Bauchet, Marc; Zaidi, Arslan A; Yao, Wei; Tang, Hua; Barsh, Gregory S; Absher, Devin M; Puts, David A; Rocha, Jorge; Beleza, Sandra; Pereira, Rinaldo W; Baynam, Gareth; Suetens, Paul; Vandermeulen, Dirk; Wagner, Jennifer K; Boster, James S; Shriver, Mark D
2014-03-01
Human facial diversity is substantial, complex, and largely scientifically unexplained. We used spatially dense quasi-landmarks to measure face shape in population samples with mixed West African and European ancestry from three locations (United States, Brazil, and Cape Verde). Using bootstrapped response-based imputation modeling (BRIM), we uncover the relationships between facial variation and the effects of sex, genomic ancestry, and a subset of craniofacial candidate genes. The facial effects of these variables are summarized as response-based imputed predictor (RIP) variables, which are validated using self-reported sex, genomic ancestry, and observer-based facial ratings (femininity and proportional ancestry) and judgments (sex and population group). By jointly modeling sex, genomic ancestry, and genotype, the independent effects of particular alleles on facial features can be uncovered. Results on a set of 20 genes showing significant effects on facial features provide support for this approach as a novel means to identify genes affecting normal-range facial features and for approximating the appearance of a face from genetic markers.
Modeling 3D Facial Shape from DNA
Claes, Peter; Liberton, Denise K.; Daniels, Katleen; Rosana, Kerri Matthes; Quillen, Ellen E.; Pearson, Laurel N.; McEvoy, Brian; Bauchet, Marc; Zaidi, Arslan A.; Yao, Wei; Tang, Hua; Barsh, Gregory S.; Absher, Devin M.; Puts, David A.; Rocha, Jorge; Beleza, Sandra; Pereira, Rinaldo W.; Baynam, Gareth; Suetens, Paul; Vandermeulen, Dirk; Wagner, Jennifer K.; Boster, James S.; Shriver, Mark D.
2014-01-01
Human facial diversity is substantial, complex, and largely scientifically unexplained. We used spatially dense quasi-landmarks to measure face shape in population samples with mixed West African and European ancestry from three locations (United States, Brazil, and Cape Verde). Using bootstrapped response-based imputation modeling (BRIM), we uncover the relationships between facial variation and the effects of sex, genomic ancestry, and a subset of craniofacial candidate genes. The facial effects of these variables are summarized as response-based imputed predictor (RIP) variables, which are validated using self-reported sex, genomic ancestry, and observer-based facial ratings (femininity and proportional ancestry) and judgments (sex and population group). By jointly modeling sex, genomic ancestry, and genotype, the independent effects of particular alleles on facial features can be uncovered. Results on a set of 20 genes showing significant effects on facial features provide support for this approach as a novel means to identify genes affecting normal-range facial features and for approximating the appearance of a face from genetic markers. PMID:24651127
Modelling Polymer Deformation during 3D Printing
NASA Astrophysics Data System (ADS)
McIlroy, Claire; Olmsted, Peter
Three-dimensional printing has the potential to transform manufacturing processes, yet improving the strength of printed parts, to equal that of traditionally-manufactured parts, remains an underlying issue. The fused deposition modelling technique involves melting a thermoplastic, followed by layer-by-layer extrusion to fabricate an object. The key to ensuring strength at the weld between layers is successful inter-diffusion. However, prior to welding, both the extrusion process and the cooling temperature profile can significantly deform the polymer micro-structure and, consequently, how well the polymers are able to ``re-entangle'' across the weld. In particular, polymer alignment in the flow can cause de-bonding of the layers and create defects. We have developed a simple model of the non-isothermal extrusion process to explore the effects that typical printing conditions and material rheology have on the conformation of a polymer melt. In particular, we incorporate both stretch and orientation using the Rolie-Poly constitutive equation to examine the melt structure as it flows through the nozzle, the subsequent alignment with the build plate and the resulting deformation due to the fixed nozzle height, which is typically less than the nozzle radius.
Image based 3D city modeling : Comparative study
NASA Astrophysics Data System (ADS)
Singh, S. P.; Jain, K.; Mandla, V. R.
2014-06-01
3D city model is a digital representation of the Earth's surface and it's related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing rapidly for various engineering and non-engineering applications. Generally four main image based approaches were used for virtual 3D city models generation. In first approach, researchers were used Sketch based modeling, second method is Procedural grammar based modeling, third approach is Close range photogrammetry based modeling and fourth approach is mainly based on Computer Vision techniques. SketchUp, CityEngine, Photomodeler and Agisoft Photoscan are the main softwares to represent these approaches respectively. These softwares have different approaches & methods suitable for image based 3D city modeling. Literature study shows that till date, there is no complete such type of comparative study available to create complete 3D city model by using images. This paper gives a comparative assessment of these four image based 3D modeling approaches. This comparative study is mainly based on data acquisition methods, data processing techniques and output 3D model products. For this research work, study area is the campus of civil engineering department, Indian Institute of Technology, Roorkee (India). This 3D campus acts as a prototype for city. This study also explains various governing parameters, factors and work experiences. This research work also gives a brief introduction, strengths and weakness of these four image based techniques. Some personal comment is also given as what can do or what can't do from these softwares. At the last, this study shows; it concluded that, each and every software has some advantages and limitations. Choice of software depends on user requirements of 3D project. For normal visualization project, SketchUp software is a good option. For 3D documentation record, Photomodeler gives good result. For Large city
NoSQL Based 3D City Model Management System
NASA Astrophysics Data System (ADS)
Mao, B.; Harrie, L.; Cao, J.; Wu, Z.; Shen, J.
2014-04-01
To manage increasingly complicated 3D city models, a framework based on NoSQL database is proposed in this paper. The framework supports import and export of 3D city model according to international standards such as CityGML, KML/COLLADA and X3D. We also suggest and implement 3D model analysis and visualization in the framework. For city model analysis, 3D geometry data and semantic information (such as name, height, area, price and so on) are stored and processed separately. We use a Map-Reduce method to deal with the 3D geometry data since it is more complex, while the semantic analysis is mainly based on database query operation. For visualization, a multiple 3D city representation structure CityTree is implemented within the framework to support dynamic LODs based on user viewpoint. Also, the proposed framework is easily extensible and supports geoindexes to speed up the querying. Our experimental results show that the proposed 3D city management system can efficiently fulfil the analysis and visualization requirements.
3D thermal analysis of rectangular microscale inorganic light-emitting diodes in a pulsed operation
NASA Astrophysics Data System (ADS)
Cui, Y.; Bian, Z.; Li, Y.; Xing, Y.; Song, J.
2016-10-01
Microscale inorganic light-emitting diodes (µ-ILEDs) have attracted much attention due to their excellent performance in biointegrated applications such as optogenetics. The thermal behaviors of µ-ILEDs are critically important since a certain temperature increase may degrade the LED performance and cause tissue lesion. The µ-ILEDs in a pulsed operation offer an advantage in thermal management. In this paper, a 3D analytic model, as validated by finite element analysis, is developed to study the thermal response of rectangular µ-ILEDs in a pulsed operation. A scaling law for the maximum normalized temperature increase of rectangular µ-ILEDs in terms of non-dimensional parameters is established. The influences of geometric (i.e. shape factor) and loading parameters (e.g. duty cycle and period) on the temperature increase are systematically investigated. These results are very helpful in designing µ-ILEDs by providing guidelines to avoid adverse thermal effects.
Modeling cell migration in 3D: Status and challenges.
Rangarajan, Rajagopal; Zaman, Muhammad H
2008-01-01
Cell migration is a multi-scale process that integrates signaling, mechanics and biochemical reaction kinetics. Various mathematical models accurately predict cell migration on 2D surfaces, but are unable to capture the complexities of 3D migration. Additionally, quantitative 3D cell migration models have been few and far between. In this review we look and characterize various mathematical models available in literature to predict cell migration in 3D matrices and analyze their strengths and possible changes to these models that could improve their predictive capabilities.
3D PIC Modeling of Microcavity Discharge
NASA Astrophysics Data System (ADS)
Hopkins, Matthew; Manginell, Ronald; Moore, Christopher; Yee, Benjamin; Moorman, Matthew
2015-09-01
We present a number of techniques and challenges in simulating the transient behavior of a microcavity discharge. Our microcavities are typically cylindrical with diameters approximately 50 - 100 μm, heights of 50 - 200 μm, pressure near atmospheric, and operate at a few hundred volts. We employ a fully kinetic simulation methodology, the Particle-in-Cell (PIC) method, with interparticle collisions handled via methods based on direct simulation Monte Carlo (DSMC). In particular, we explicitly include kinetic electrons. Some of the challenges we encounter include variations in number densities, external circuit coupling, and time step resolution constraints. By employing dynamic particle weighting (particle weights vary over time by species and location) we can mitigate some of the challenges modeling systems with 107 variations in number densities. Smoothing mechanisms have been used to attempt to mitigate external circuit response. We perform our simulations on hundreds or thousands of processing cores to accommodate the computational work inherent in using relatively small time step sizes (e.g., 50 fs for a 100 ns calculation). In addition, particle weighting issues inherent to three-dimensional low temperature plasma systems will be mentioned. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's NNSA under Contract DE-AC04-94AL85000.
NASA Astrophysics Data System (ADS)
Przyborska, Anna; Kosecki, Szymon; Jakacki, Jaromir
2014-05-01
Kongsfjorden is a West Svalbard fjord with a surface area of about 210 km2. It is obvious that the depths of the outer and central basins are influenced by the open sea, under influence of West Spitsbergen Current (WSC), which curry out warm Atlantic water and cold East Spitsbergen Current, while the shallower, inner basin has a large glacial outflow and its maximum depths do not exceed 100 m. Freshwater stored in Spitsbergen glaciers have strong influence on local hydrology and physical fjord conditions. Both, local and shelf conditions have impact on state of the fjord. External forces like tides, velocities at the boundary and atmospheric forces together with sources of cold and dens fresh water in the fjords will give reliable representation of physical conditions in Kongsfjorden. Modeling could help to solve this problem and we have hope that we find answer which one is the most important for local conditions in fjord. Calculations of balances between cold fresh water and warm and salt will provide additional information that could help to answer the main question of the GAME (Growing of the Arctic Marine Ecosystem) project - what is the reaction of physically controlled Arctic marine ecosystem to temperature rise.
3D model retrieval method based on mesh segmentation
NASA Astrophysics Data System (ADS)
Gan, Yuanchao; Tang, Yan; Zhang, Qingchen
2012-04-01
In the process of feature description and extraction, current 3D model retrieval algorithms focus on the global features of 3D models but ignore the combination of global and local features of the model. For this reason, they show less effective performance to the models with similar global shape and different local shape. This paper proposes a novel algorithm for 3D model retrieval based on mesh segmentation. The key idea is to exact the structure feature and the local shape feature of 3D models, and then to compares the similarities of the two characteristics and the total similarity between the models. A system that realizes this approach was built and tested on a database of 200 objects and achieves expected results. The results show that the proposed algorithm improves the precision and the recall rate effectively.
3-D numerical modeling of plume-induced subduction initiation
NASA Astrophysics Data System (ADS)
Baes, Marzieh; Gerya, taras; Sobolev, Stephan
2016-04-01
Investigation of mechanisms involved in formation of a new subduction zone can help us to better understand plate tectonics. Despite numerous previous studies, it is still unclear how and where an old oceanic plate starts to subduct beneath the other plate. One of the proposed scenarios for nucleation of subduction is plume-induced subduction initiation, which was investigated in detail, using 2-D models, by Ueda et al. (2008). Recently. Gerya et al. (2015), using 3D numerical models, proposed that plume-lithosphere interaction in the Archean led to the subduction initiation and onset of plate tectonic. In this study, we aim to pursue work of Ueda et al. (2008) by incorporation of 3-D thermo-mechanical models to investigate conditions leading to oceanic subduction initiation as a result of thermal-chemical mantle plume-lithosphere interaction in the modern earth. Results of our experiments show four different deformation regimes in response to plume-lithosphere interaction, that are a) self-sustaining subduction initiation where subduction becomes self-sustained, b) freezing subduction initiation where subduction stops at shallow depths, c) slab break-off where subducting circular slab breaks off soon after formation and d) plume underplating where plume does not pass through the lithosphere but spreads beneath it (failed subduction initiation). These different regimes depend on several parameters such as plume's size, composition and temperature, lithospheric brittle/plastic strength, age of the oceanic lithosphere and presence/absence of lithospheric heterogeneities. Results show that subduction initiates and becomes self-sustained when lithosphere is older than 10 Myr and non-dimensional ratio of the plume buoyancy force and lithospheric strength above the plume is higher than 2.
Tawfik, Abdelrazak M; El-Ghamry, Mosad A; Abu-El-Wafa, Samy M; Ahmed, Naglaa M
2012-11-01
New series of Schiff base ligand H(2)L and their Cu(II) and Mn(II) complexes derived from azosulfapyrimidine were synthesized and characterized by elemental and thermal studies conductance measurements IR, electronic and EPR spectra. 3D modeling of the ligand indicate that azo group does not participate in complex formation and surface potential on one of the ligand under study indicate that electron density around azomethine groups are much higher than the azo group therefore coordination takes place around azomethine groups. The variety in the geometrical structures depends on the nature of both the metal ions and the Schiff base ligands. The thermo kinetic parameters are calculated and discussed. The biological activities of the ligands and complexes have been screened in vitro against some bacteria and fungi to study their capacity to inhibit their growth and to study the toxicity of the compounds.
NASA Astrophysics Data System (ADS)
Tawfik, Abdelrazak M.; El-ghamry, Mosad A.; Abu-El-Wafa, Samy M.; Ahmed, Naglaa M.
2012-11-01
New series of Schiff base ligand H2L and their Cu(II) and Mn(II) complexes derived from azosulfapyrimidine were synthesized and characterized by elemental and thermal studies conductance measurements IR, electronic and EPR spectra. 3D modeling of the ligand indicate that azo group does not participate in complex formation and surface potential on one of the ligand under study indicate that electron density around azomethine groups are much higher than the azo group therefore coordination takes place around azomethine groups. The variety in the geometrical structures depends on the nature of both the metal ions and the Schiff base ligands. The thermo kinetic parameters are calculated and discussed. The biological activities of the ligands and complexes have been screened in vitro against some bacteria and fungi to study their capacity to inhibit their growth and to study the toxicity of the compounds.
High Resolution 3d Modeling of the Behaim Globe
NASA Astrophysics Data System (ADS)
Menna, F.; Rizzi, A.; Nocerino, E.; Remondino, F.; Gruen, A.
2012-07-01
The article describes the 3D surveying and modeling of the Behaim globe, the oldest still existing and intact globe of the earth, preserved at the German National Museum of Nuremberg, Germany. The work is primarily performed using high-resolution digital images and automatic photogrammetric techniques. Triangulation-based laser scanning is also employed to fill some gaps in the derived image-based 3D geometry and perform geometric comparisons. Major problems are encountered in texture mapping. The 3D modeling project and the creation of high-resolution map-projections is performed for scientific, conservation, visualization and education purposes.
3D-model building of the jaw impression
NASA Astrophysics Data System (ADS)
Ahmed, Moumen T.; Yamany, Sameh M.; Hemayed, Elsayed E.; Farag, Aly A.
1997-03-01
A novel approach is proposed to obtain a record of the patient's occlusion using computer vision. Data acquisition is obtained using intra-oral video cameras. The technique utilizes shape from shading to extract 3D information from 2D views of the jaw, and a novel technique for 3D data registration using genetic algorithms. The resulting 3D model can be used for diagnosis, treatment planning, and implant purposes. The overall purpose of this research is to develop a model-based vision system for orthodontics to replace traditional approaches. This system will be flexible, accurate, and will reduce the cost of orthodontic treatments.
Summary on several key techniques in 3D geological modeling.
Mei, Gang
2014-01-01
Several key techniques in 3D geological modeling including planar mesh generation, spatial interpolation, and surface intersection are summarized in this paper. Note that these techniques are generic and widely used in various applications but play a key role in 3D geological modeling. There are two essential procedures in 3D geological modeling: the first is the simulation of geological interfaces using geometric surfaces and the second is the building of geological objects by means of various geometric computations such as the intersection of surfaces. Discrete geometric surfaces that represent geological interfaces can be generated by creating planar meshes first and then spatially interpolating; those surfaces intersect and then form volumes that represent three-dimensional geological objects such as rock bodies. In this paper, the most commonly used algorithms of the key techniques in 3D geological modeling are summarized.
Summary on Several Key Techniques in 3D Geological Modeling
2014-01-01
Several key techniques in 3D geological modeling including planar mesh generation, spatial interpolation, and surface intersection are summarized in this paper. Note that these techniques are generic and widely used in various applications but play a key role in 3D geological modeling. There are two essential procedures in 3D geological modeling: the first is the simulation of geological interfaces using geometric surfaces and the second is the building of geological objects by means of various geometric computations such as the intersection of surfaces. Discrete geometric surfaces that represent geological interfaces can be generated by creating planar meshes first and then spatially interpolating; those surfaces intersect and then form volumes that represent three-dimensional geological objects such as rock bodies. In this paper, the most commonly used algorithms of the key techniques in 3D geological modeling are summarized. PMID:24772029
Formal representation of 3D structural geological models
NASA Astrophysics Data System (ADS)
Wang, Zhangang; Qu, Honggang; Wu, Zixing; Yang, Hongjun; Du, Qunle
2016-05-01
The development and widespread application of geological modeling methods has increased demands for the integration and sharing services of three dimensional (3D) geological data. However, theoretical research in the field of geological information sciences is limited despite the widespread use of Geographic Information Systems (GIS) in geology. In particular, fundamental research on the formal representations and standardized spatial descriptions of 3D structural models is required. This is necessary for accurate understanding and further applications of geological data in 3D space. In this paper, we propose a formal representation method for 3D structural models using the theory of point set topology, which produces a mathematical definition for the major types of geological objects. The spatial relationships between geologic boundaries, structures, and units are explained in detail using the 9-intersection model. Reasonable conditions for describing the topological space of 3D structural models are also provided. The results from this study can be used as potential support for the standardized representation and spatial quality evaluation of 3D structural models, as well as for specific needs related to model-based management, query, and analysis.
First 3D thermal mapping of an active volcano using an advanced photogrammetric method
NASA Astrophysics Data System (ADS)
Antoine, Raphael; Baratoux, David; Lacogne, Julien; Lopez, Teodolina; Fauchard, Cyrille; Bretar, Frédéric; Arab-Sedze, Mélanie; Staudacher, Thomas; Jacquemoud, Stéphane; Pierrot-Deseilligny, Marc
2014-05-01
to extract 3D informations from thermal images taken from different positions. This paper presents the first 3D thermal map of an active volcano (Piton de la Fournaise, La Réunion Island) directly generated from 70 thermal images (so-called "stereothermogrammetric" DEM). The data were obtained above Dolomieu caldera by helicopter just before sunrise, during a clear weather in 2008. They were obtained before the eruptive events occurring within the Dolomieu caldera. We used a 28 mm focal FLIR Thermacam PM695 lent by the Piton de la Fournaise Observatory. The thermal images were acquired automatically every 30 seconds with the helicopter flying around the caldera at low altitude (less than 100 m height above the caldera). This survey led to the acquisition of images with a ground pixel size in the range of 1-3 m. A particular attention has been brought to the obtaining of a high overlap percentage (80 percents) for the localization of the maximum tie points on the image. Finally, the acquisition of 70 images allowed the generation of a 3D thermal model of the caldera containing more than 500000 points. i.e. 1 point each 2 m², considering a surface of 106 m² for the Dolomieu caldera. This model is then compared with a DEM recently obtained with the LIDAR method after the eruptive events occurring within Dolomieu. The comparison of these independent methods leads to the validation of the stereothermogrammetric method. It allows the quantification of the thickness of the lava flows within the Dolomieu collapse in 2008 and 2009, i.e. approximately 80 meters, as estimated by previous studies from field observations.
Alignment of 3D Building Models and TIR Video Sequences with Line Tracking
NASA Astrophysics Data System (ADS)
Iwaszczuk, D.; Stilla, U.
2014-11-01
Thermal infrared imagery of urban areas became interesting for urban climate investigations and thermal building inspections. Using a flying platform such as UAV or a helicopter for the acquisition and combining the thermal data with the 3D building models via texturing delivers a valuable groundwork for large-area building inspections. However, such thermal textures are useful for further analysis if they are geometrically correctly extracted. This can be achieved with a good coregistrations between the 3D building models and thermal images, which cannot be achieved by direct georeferencing. Hence, this paper presents methodology for alignment of 3D building models and oblique TIR image sequences taken from a flying platform. In a single image line correspondences between model edges and image line segments are found using accumulator approach and based on these correspondences an optimal camera pose is calculated to ensure the best match between the projected model and the image structures. Among the sequence the linear features are tracked based on visibility prediction. The results of the proposed methodology are presented using a TIR image sequence taken from helicopter in a densely built-up urban area. The novelty of this work is given by employing the uncertainty of the 3D building models and by innovative tracking strategy based on a priori knowledge from the 3D building model and the visibility checking.
Vehicle Surveillance with a Generic, Adaptive, 3D Vehicle Model.
Leotta, Matthew J; Mundy, Joseph L
2011-07-01
In automated surveillance, one is often interested in tracking road vehicles, measuring their shape in 3D world space, and determining vehicle classification. To address these tasks simultaneously, an effective approach is the constrained alignment of a prior model of 3D vehicle shape to images. Previous 3D vehicle models are either generic but overly simple or rigid and overly complex. Rigid models represent exactly one vehicle design, so a large collection is needed. A single generic model can deform to a wide variety of shapes, but those shapes have been far too primitive. This paper uses a generic 3D vehicle model that deforms to match a wide variety of passenger vehicles. It is adjustable in complexity between the two extremes. The model is aligned to images by predicting and matching image intensity edges. Novel algorithms are presented for fitting models to multiple still images and simultaneous tracking while estimating shape in video. Experiments compare the proposed model to simple generic models in accuracy and reliability of 3D shape recovery from images and tracking in video. Standard techniques for classification are also used to compare the models. The proposed model outperforms the existing simple models at each task.
Langerman, M.A.
1990-09-01
Steady-state modeling considerations for simulating the in situ vitrification (ISV) process are documented based upon the finite element numerical approach. Recommendations regarding boundary condition specifications and mesh discretization are presented. The effects of several parameters on the ISV process response are calculated and the results discussed. The parameters investigated include: (1) electrode depth, (2) ambient temperature, (3) supplied current, (4) electrical conductivity, (5) electrode separation, and (6) soil/waste characterization. 13 refs., 29 figs., 1 tab.
3D Modeling from Photos Given Topological Information.
Kim, Young Min; Cho, Junghyun; Ahn, Sang Chul
2016-09-01
Reconstructing 3D models given a single-view 2D information is inherently an ill-posed problem and requires additional information such as shape prior or user input.We introduce a method to generate multiple 3D models of a particular category given corresponding photographs when the topological information is known. While there is a wide range of shapes for an object of a particular category, the basic topology usually remains constant.In consequence, the topological prior needs to be provided only once for each category and can be easily acquired by consulting an existing database of 3D models or by user input. The input of topological description is only connectivity information between parts; this is in contrast to previous approaches that have required users to interactively mark individual parts. Given the silhouette of an object and the topology, our system automatically finds a skeleton and generates a textured 3D model by jointly fitting multiple parts. The proposed method, therefore, opens the possibility of generating a large number of 3D models by consulting a massive number of photographs. We demonstrate examples of the topological prior and reconstructed 3D models using photos.
Performance Evaluation of 3d Modeling Software for Uav Photogrammetry
NASA Astrophysics Data System (ADS)
Yanagi, H.; Chikatsu, H.
2016-06-01
UAV (Unmanned Aerial Vehicle) photogrammetry, which combines UAV and freely available internet-based 3D modeling software, is widely used as a low-cost and user-friendly photogrammetry technique in the fields such as remote sensing and geosciences. In UAV photogrammetry, only the platform used in conventional aerial photogrammetry is changed. Consequently, 3D modeling software contributes significantly to its expansion. However, the algorithms of the 3D modelling software are black box algorithms. As a result, only a few studies have been able to evaluate their accuracy using 3D coordinate check points. With this motive, Smart3DCapture and Pix4Dmapper were downloaded from the Internet and commercial software PhotoScan was also employed; investigations were performed in this paper using check points and images obtained from UAV.
Automated 3D Damaged Cavity Model Builder for Lower Surface Acreage Tile on Orbiter
NASA Technical Reports Server (NTRS)
Belknap, Shannon; Zhang, Michael
2013-01-01
The 3D Automated Thermal Tool for Damaged Acreage Tile Math Model builder was developed to perform quickly and accurately 3D thermal analyses on damaged lower surface acreage tiles and structures beneath the damaged locations on a Space Shuttle Orbiter. The 3D model builder created both TRASYS geometric math models (GMMs) and SINDA thermal math models (TMMs) to simulate an idealized damaged cavity in the damaged tile(s). The GMMs are processed in TRASYS to generate radiation conductors between the surfaces in the cavity. The radiation conductors are inserted into the TMMs, which are processed in SINDA to generate temperature histories for all of the nodes on each layer of the TMM. The invention allows a thermal analyst to create quickly and accurately a 3D model of a damaged lower surface tile on the orbiter. The 3D model builder can generate a GMM and the correspond ing TMM in one or two minutes, with the damaged cavity included in the tile material. A separate program creates a configuration file, which would take a couple of minutes to edit. This configuration file is read by the model builder program to determine the location of the damage, the correct tile type, tile thickness, structure thickness, and SIP thickness of the damage, so that the model builder program can build an accurate model at the specified location. Once the models are built, they are processed by the TRASYS and SINDA.
Automatic Texture Mapping of Architectural and Archaeological 3d Models
NASA Astrophysics Data System (ADS)
Kersten, T. P.; Stallmann, D.
2012-07-01
Today, detailed, complete and exact 3D models with photo-realistic textures are increasingly demanded for numerous applications in architecture and archaeology. Manual texture mapping of 3D models by digital photographs with software packages, such as Maxon Cinema 4D, Autodesk 3Ds Max or Maya, still requires a complex and time-consuming workflow. So, procedures for automatic texture mapping of 3D models are in demand. In this paper two automatic procedures are presented. The first procedure generates 3D surface models with textures by web services, while the second procedure textures already existing 3D models with the software tmapper. The program tmapper is based on the Multi Layer 3D image (ML3DImage) algorithm and developed in the programming language C++. The studies showing that the visibility analysis using the ML3DImage algorithm is not sufficient to obtain acceptable results of automatic texture mapping. To overcome the visibility problem the Point Cloud Painter algorithm in combination with the Z-buffer-procedure will be applied in the future.
Quasi-3D Algorithm in Multi-scale Modeling Framework
NASA Astrophysics Data System (ADS)
Jung, J.; Arakawa, A.
2008-12-01
As discussed in the companion paper by Arakawa and Jung, the Quasi-3D (Q3D) Multi-scale Modeling Framework (MMF) is a 4D estimation/prediction framework that combines a GCM with a 3D anelastic vector vorticity equation model (VVM) applied to a Q3D network of horizontal grid points. This paper presents an outline of the recently revised Q3D algorithm and a highlight of the results obtained by application of the algorithm to an idealized model setting. The Q3D network of grid points consists of two sets of grid-point arrays perpendicular to each other. For a scalar variable, for example, each set consists of three parallel rows of grid points. Principal and supplementary predictions are made on the central and the two adjacent rows, respectively. The supplementary prediction is to allow the principal prediction be three-dimensional at least to the second-order accuracy. To accommodate a higher-order accuracy and to make the supplementary predictions formally three-dimensional, a few rows of ghost points are added at each side of the array. Values at these ghost points are diagnostically determined by a combination of statistical estimation and extrapolation. The basic structure of the estimation algorithm is determined in view of the global stability of Q3D advection. The algorithm is calibrated using the statistics of past data at and near the intersections of the two sets of grid- point arrays. Since the CRM in the Q3D MMF extends beyond individual GCM boxes, the CRM can be a GCM by itself. However, it is better to couple the CRM with the GCM because (1) the CRM is a Q3D CRM based on a highly anisotropic network of grid points and (2) coupling with a GCM makes it more straightforward to inherit our experience with the conventional GCMs. In the coupled system we have selected, prediction of thermdynamic variables is almost entirely done by the Q3D CRM with no direct forcing by the GCM. The coupling of the dynamics between the two components is through mutual
Combined registration of 3D tibia and femur implant models in 3D magnetic resonance images
NASA Astrophysics Data System (ADS)
Englmeier, Karl-Hans; Siebert, Markus; von Eisenhart-Rothe, Ruediger; Graichen, Heiko
2008-03-01
The most frequent reasons for revision of total knee arthroplasty are loosening and abnormal axial alignment leading to an unphysiological kinematic of the knee implant. To get an idea about the postoperative kinematic of the implant, it is essential to determine the position and orientation of the tibial and femoral prosthesis. Therefore we developed a registration method for fitting 3D CAD-models of knee joint prostheses into an 3D MR image. This rigid registration is the basis for a quantitative analysis of the kinematics of knee implants. Firstly the surface data of the prostheses models are converted into a voxel representation; a recursive algorithm determines all boundary voxels of the original triangular surface data. Secondly an initial preconfiguration of the implants by the user is still necessary for the following step: The user has to perform a rough preconfiguration of both remaining prostheses models, so that the fine matching process gets a reasonable starting point. After that an automated gradient-based fine matching process determines the best absolute position and orientation: This iterative process changes all 6 parameters (3 rotational- and 3 translational parameters) of a model by a minimal amount until a maximum value of the matching function is reached. To examine the spread of the final solutions of the registration, the interobserver variability was measured in a group of testers. This variability, calculated by the relative standard deviation, improved from about 50% (pure manual registration) to 0.5% (rough manual preconfiguration and subsequent fine registration with the automatic fine matching process).
NASA Astrophysics Data System (ADS)
Junk, S.
2016-08-01
Today the methods of numerical simulation of sheet metal forming offer a great diversity of possibilities for optimization in product development and in process design. However, the results from simulation are only available as virtual models. Because there are any forming tools available during the early stages of product development, physical models that could serve to represent the virtual results are therefore lacking. Physical 3D-models can be created using 3D-printing and serve as an illustration and present a better understanding of the simulation results. In this way, the results from the simulation can be made more “comprehensible” within a development team. This paper presents the possibilities of 3D-colour printing with particular consideration of the requirements regarding the implementation of sheet metal forming simulation. Using concrete examples of sheet metal forming, the manufacturing of 3D colour models will be expounded upon on the basis of simulation results.
Cookoff response of PBXN-109: material characterization and ALE3D model
McClelland, M A; Tran, T D; Cunningham, B J; Weese, R K; Maienschein, J L
2000-10-24
Materials properties measurements are made for the RDX-based explosive, PBXN-109, and an initial ALE3D model for cookoff is discussed. A significant effort is underway in the U.S. Navy and Department of Energy (DOE) laboratories to understand the thermal explosion behavior of this material. Benchmark cookoff experiments are being performed by the U.S. Navy to validate DOE materials models and computer codes. The ALE3D computer code can model the coupled thermal, mechanical, and chemical behavior of heating and ignition in cookoff tests. In order to provide a predictive capability, materials characterization measurements are being performed to specify parameters in these models. We report on progress in the development of these ALE3D materials models and present measurements as a function of temperature for thermal expansion, heat capacity, shear modulus, bulk modulus, and One-Dimensional-Time-to-Explosion (ODTX).
3D Bioprinting of Tissue/Organ Models.
Pati, Falguni; Gantelius, Jesper; Svahn, Helene Andersson
2016-04-04
In vitro tissue/organ models are useful platforms that can facilitate systematic, repetitive, and quantitative investigations of drugs/chemicals. The primary objective when developing tissue/organ models is to reproduce physiologically relevant functions that typically require complex culture systems. Bioprinting offers exciting prospects for constructing 3D tissue/organ models, as it enables the reproducible, automated production of complex living tissues. Bioprinted tissues/organs may prove useful for screening novel compounds or predicting toxicity, as the spatial and chemical complexity inherent to native tissues/organs can be recreated. In this Review, we highlight the importance of developing 3D in vitro tissue/organ models by 3D bioprinting techniques, characterization of these models for evaluating their resemblance to native tissue, and their application in the prioritization of lead candidates, toxicity testing, and as disease/tumor models.
3D WHOLE-PROMINENCE FINE STRUCTURE MODELING
Gunár, Stanislav; Mackay, Duncan H.
2015-04-20
We present the first 3D whole-prominence fine structure model. The model combines a 3D magnetic field configuration of an entire prominence obtained from nonlinear force-free field simulations, with a detailed description of the prominence plasma. The plasma is located in magnetic dips in hydrostatic equilibrium and is distributed along multiple fine structures within the 3D magnetic model. Through the use of a novel radiative transfer visualization technique for the Hα line such plasma-loaded magnetic field model produces synthetic images of the modeled prominence comparable with high-resolution observations. This allows us for the first time to use a single technique to consistently study, in both emission on the limb and absorption against the solar disk, the fine structures of prominences/filaments produced by a magnetic field model.
3D web visualization of huge CityGML models
NASA Astrophysics Data System (ADS)
Prandi, F.; Devigili, F.; Soave, M.; Di Staso, U.; De Amicis, R.
2015-08-01
Nowadays, rapid technological development into acquiring geo-spatial information; joined to the capabilities to process these data in a relative short period of time, allows the generation of detailed 3D textured city models that will become an essential part of the modern city information infrastructure (Spatial Data Infrastructure) and, can be used to integrate various data from different sources for public accessible visualisation and many other applications. One of the main bottlenecks, which at the moment limit the use of these datasets to few experts, is a lack on efficient visualization systems through the web and interoperable frameworks that allow standardising the access to the city models. The work presented in this paper tries to satisfy these two requirements developing a 3D web-based visualization system based on OGC standards and effective visualization concepts. The architectural framework, based on Services Oriented Architecture (SOA) concepts, provides the 3D city data to a web client designed to support the view process in a very effective way. The first part of the work is to design a framework compliant to the 3D Portrayal Service drafted by the of the Open Geospatial Consortium (OGC) 3D standardization working group. The latter is related to the development of an effective web client able to render in an efficient way the 3D city models.
3D microstructure modeling of compressed fiber-based materials
NASA Astrophysics Data System (ADS)
Gaiselmann, Gerd; Tötzke, Christian; Manke, Ingo; Lehnert, Werner; Schmidt, Volker
2014-07-01
A novel parametrized model that describes the 3D microstructure of compressed fiber-based materials is introduced. It allows to virtually generate the microstructure of realistically compressed gas-diffusion layers (GDL). Given the input of a 3D microstructure of some fiber-based material, the model compresses the system of fibers in a uniaxial direction for arbitrary compression rates. The basic idea is to translate the fibers in the direction of compression according to a vector field which depends on the rate of compression and on the locations of fibers within the material. In order to apply the model to experimental 3D image data of fiber-based materials given for several compression states, an optimal vector field is estimated by simulated annealing. The model is applied to 3D image data of non-woven GDL in PEMFC gained by synchrotron tomography for different compression rates. The compression model is validated by comparing structural characteristics computed for experimentally compressed and virtually compressed microstructures, where two kinds of compression - using a flat stamp and a stamp with a flow-field profile - are applied. For both stamps types, a good agreement is found. Furthermore, the compression model is combined with a stochastic 3D microstructure model for uncompressed fiber-based materials. This allows to efficiently generate compressed fiber-based microstructures in arbitrary volumes.
Perception-based shape retrieval for 3D building models
NASA Astrophysics Data System (ADS)
Zhang, Man; Zhang, Liqiang; Takis Mathiopoulos, P.; Ding, Yusi; Wang, Hao
2013-01-01
With the help of 3D search engines, a large number of 3D building models can be retrieved freely online. A serious disadvantage of most rotation-insensitive shape descriptors is their inability to distinguish between two 3D building models which are different at their main axes, but appear similar when one of them is rotated. To resolve this problem, we present a novel upright-based normalization method which not only correctly rotates such building models, but also greatly simplifies and accelerates the abstraction and the matching of building models' shape descriptors. Moreover, the abundance of architectural styles significantly hinders the effective shape retrieval of building models. Our research has shown that buildings with different designs are not well distinguished by the widely recognized shape descriptors for general 3D models. Motivated by this observation and to further improve the shape retrieval quality, a new building matching method is introduced and analyzed based on concepts found in the field of perception theory and the well-known Light Field descriptor. The resulting normalized building models are first classified using the qualitative shape descriptors of Shell and Unevenness which outline integral geometrical and topological information. These models are then put in on orderly fashion with the help of an improved quantitative shape descriptor which we will term as Horizontal Light Field Descriptor, since it assembles detailed shape characteristics. To accurately evaluate the proposed methodology, an enlarged building shape database which extends previous well-known shape benchmarks was implemented as well as a model retrieval system supporting inputs from 2D sketches and 3D models. Various experimental performance evaluation results have shown that, as compared to previous methods, retrievals employing the proposed matching methodology are faster and more consistent with human recognition of spatial objects. In addition these performance
Shape: A 3D Modeling Tool for Astrophysics.
Steffen, Wolfgang; Koning, Nicholas; Wenger, Stephan; Morisset, Christophe; Magnor, Marcus
2011-04-01
We present a flexible interactive 3D morpho-kinematical modeling application for astrophysics. Compared to other systems, our application reduces the restrictions on the physical assumptions, data type, and amount that is required for a reconstruction of an object's morphology. It is one of the first publicly available tools to apply interactive graphics to astrophysical modeling. The tool allows astrophysicists to provide a priori knowledge about the object by interactively defining 3D structural elements. By direct comparison of model prediction with observational data, model parameters can then be automatically optimized to fit the observation. The tool has already been successfully used in a number of astrophysical research projects.
Study of the thermal properties of filaments for 3D printing
NASA Astrophysics Data System (ADS)
Trhlíková, Lucie; Zmeskal, Oldrich; Psencik, Petr; Florian, Pavel
2016-07-01
Various materials are used for 3D printing, most commonly Acrylonitrile butadiene styrene (ABS), Polylactic acid (PLA), Polyethylene (PET) and Polypropylene (PP). These materials differ mainly in their melting point, which significantly influences the properties of the final products. Filaments are melted in the print head during the printing process. The temperature range is from 150 °C to 250 °C depending on the technology used. The optimum temperature for the cooling substrate on which printing is carried out is chosen so as to ensure uniform cooling and deformation. It generally varies between (40 - 100) °C. From the above it is clear that both temperatures can significantly affect the properties of the printed 3D object. It is therefore important to determine the thermal parameters (thermal conductivity, specific heat and thermal diffusivity) of the materials used across the entire range of temperatures. For evaluating the properties of different types of PLA materials, the step transient method was used, which allows determination of all required parameters using a fractal heat transfer model.
Eck, Simon; Wörz, Stefan; Müller-Ott, Katharina; Hahn, Matthias; Biesdorf, Andreas; Schotta, Gunnar; Rippe, Karsten; Rohr, Karl
2016-08-01
The genome is partitioned into regions of euchromatin and heterochromatin. The organization of heterochromatin is important for the regulation of cellular processes such as chromosome segregation and gene silencing, and their misregulation is linked to cancer and other diseases. We present a model-based approach for automatic 3D segmentation and 3D shape analysis of heterochromatin foci from 3D confocal light microscopy images. Our approach employs a novel 3D intensity model based on spherical harmonics, which analytically describes the shape and intensities of the foci. The model parameters are determined by fitting the model to the image intensities using least-squares minimization. To characterize the 3D shape of the foci, we exploit the computed spherical harmonics coefficients and determine a shape descriptor. We applied our approach to 3D synthetic image data as well as real 3D static and real 3D time-lapse microscopy images, and compared the performance with that of previous approaches. It turned out that our approach yields accurate 3D segmentation results and performs better than previous approaches. We also show that our approach can be used for quantifying 3D shape differences of heterochromatin foci.
3D Printing of Biomolecular Models for Research and Pedagogy.
Da Veiga Beltrame, Eduardo; Tyrwhitt-Drake, James; Roy, Ian; Shalaby, Raed; Suckale, Jakob; Pomeranz Krummel, Daniel
2017-03-13
The construction of physical three-dimensional (3D) models of biomolecules can uniquely contribute to the study of the structure-function relationship. 3D structures are most often perceived using the two-dimensional and exclusively visual medium of the computer screen. Converting digital 3D molecular data into real objects enables information to be perceived through an expanded range of human senses, including direct stereoscopic vision, touch, and interaction. Such tangible models facilitate new insights, enable hypothesis testing, and serve as psychological or sensory anchors for conceptual information about the functions of biomolecules. Recent advances in consumer 3D printing technology enable, for the first time, the cost-effective fabrication of high-quality and scientifically accurate models of biomolecules in a variety of molecular representations. However, the optimization of the virtual model and its printing parameters is difficult and time consuming without detailed guidance. Here, we provide a guide on the digital design and physical fabrication of biomolecule models for research and pedagogy using open source or low-cost software and low-cost 3D printers that use fused filament fabrication technology.
NASA Astrophysics Data System (ADS)
Burtnyk, Mathieu; Chopra, Rajiv; Bronskill, Michael
2010-03-01
Previous numerical simulations have shown that MRI-guided transurethral ultrasound therapy can generate highly accurate volumes of thermal coagulation conforming to 3-D human prostate geometries. The goal of this work is to simulate, quantify and evaluate the thermal impact of these treatments on the rectum, pelvic bone, neurovascular bundles (NVB) and urinary sphincters. This study used twenty 3-D anatomical models of prostate cancer patients and detailed bio-acoustic simulations incorporating an active feedback algorithm which controlled a rotating, planar ultrasound transducer (17-4×3 mm elements, 4.7/9.7 MHz, 10 Wac/cm2). Heating of the adjacent surrounding anatomy was evaluated using thermal tolerances reported in the literature. Heating of the rectum poses the most important safety concern and is influenced largely by the water temperature flowing through an endorectal cooling device; temperatures of 7-37° C are required to limit potential damage to less than 10 mm3 on the outer 1 mm layer of rectum. Significant heating of the pelvic bone was predicted in 30% of the patient models with an ultrasound frequency of 4.7 MHz; setting the frequency to 9.7 MHz when the bone is less than 10 mm away from the prostate reduced heating in all cases below the threshold for irreversible damage. Heating of the NVB was significant in 75% of the patient models in the absence of treatment planning; this proportion was reduced to 5% by using treatment margins of up to 4 mm. To avoid damaging the urinary sphincters, margins from the transducer of 2-4 mm should be used, depending on the transurethral cooling temperature. Simulations show that MRI-guided transurethral therapy can treat the entire prostate accurately. Strategies have been developed which, along with careful treatment planning, can be used to avoid causing thermal injury to the rectum, pelvic bone, NVB and urinary sphincters.
Potential of 3D City Models to assess flood vulnerability
NASA Astrophysics Data System (ADS)
Schröter, Kai; Bochow, Mathias; Schüttig, Martin; Nagel, Claus; Ross, Lutz; Kreibich, Heidi
2016-04-01
Vulnerability, as the product of exposure and susceptibility, is a key factor of the flood risk equation. Furthermore, the estimation of flood loss is very sensitive to the choice of the vulnerability model. Still, in contrast to elaborate hazard simulations, vulnerability is often considered in a simplified manner concerning the spatial resolution and geo-location of exposed objects as well as the susceptibility of these objects at risk. Usually, area specific potential flood loss is quantified on the level of aggregated land-use classes, and both hazard intensity and resistance characteristics of affected objects are represented in highly simplified terms. We investigate the potential of 3D City Models and spatial features derived from remote sensing data to improve the differentiation of vulnerability in flood risk assessment. 3D City Models are based on CityGML, an application scheme of the Geography Markup Language (GML), which represents the 3D geometry, 3D topology, semantics and appearance of objects on different levels of detail. As such, 3D City Models offer detailed spatial information which is useful to describe the exposure and to characterize the susceptibility of residential buildings at risk. This information is further consolidated with spatial features of the building stock derived from remote sensing data. Using this database a spatially detailed flood vulnerability model is developed by means of data-mining. Empirical flood damage data are used to derive and to validate flood susceptibility models for individual objects. We present first results from a prototype application in the city of Dresden, Germany. The vulnerability modeling based on 3D City Models and remote sensing data is compared i) to the generally accepted good engineering practice based on area specific loss potential and ii) to a highly detailed representation of flood vulnerability based on a building typology using urban structure types. Comparisons are drawn in terms of
3D head model classification using optimized EGI
NASA Astrophysics Data System (ADS)
Tong, Xin; Wong, Hau-san; Ma, Bo
2006-02-01
With the general availability of 3D digitizers and scanners, 3D graphical models have been used widely in a variety of applications. This has led to the development of search engines for 3D models. Especially, 3D head model classification and retrieval have received more and more attention in view of their many potential applications in criminal identifications, computer animation, movie industry and medical industry. This paper addresses the 3D head model classification problem using 2D subspace analysis methods such as 2D principal component analysis (2D PCA[3]) and 2D fisher discriminant analysis (2DLDA[5]). It takes advantage of the fact that the histogram is a 2D image, and we can extract the most useful information from these 2D images to get a good result accordingingly. As a result, there are two main advantages: First, we can perform less calculation to obtain the same rate of classification; second, we can reduce the dimensionality more than PCA to obtain a higher efficiency.
3D MHD Models of Active Region Loops
NASA Technical Reports Server (NTRS)
Ofman, Leon
2004-01-01
Present imaging and spectroscopic observations of active region loops allow to determine many physical parameters of the coronal loops, such as the density, temperature, velocity of flows in loops, and the magnetic field. However, due to projection effects many of these parameters remain ambiguous. Three dimensional imaging in EUV by the STEREO spacecraft will help to resolve the projection ambiguities, and the observations could be used to setup 3D MHD models of active region loops to study the dynamics and stability of active regions. Here the results of 3D MHD models of active region loops are presented, and the progress towards more realistic 3D MHD models of active regions. In particular the effects of impulsive events on the excitation of active region loop oscillations, and the generation, propagations and reflection of EIT waves are shown. It is shown how 3D MHD models together with 3D EUV observations can be used as a diagnostic tool for active region loop physical parameters, and to advance the science of the sources of solar coronal activity.
3D model of amphioxus steroid receptor complexed with estradiol
Baker, Michael E.; Chang, David J.
2009-08-28
The origins of signaling by vertebrate steroids are not fully understood. An important advance was the report that an estrogen-binding steroid receptor [SR] is present in amphioxus, a basal chordate with a similar body plan as vertebrates. To investigate the evolution of estrogen-binding to steroid receptors, we constructed a 3D model of amphioxus SR complexed with estradiol. This 3D model indicates that although the SR is activated by estradiol, some interactions between estradiol and human ER{alpha} are not conserved in the SR, which can explain the low affinity of estradiol for the SR. These differences between the SR and ER{alpha} in the steroid-binding domain are sufficient to suggest that another steroid is the physiological regulator of the SR. The 3D model predicts that mutation of Glu-346 to Gln will increase the affinity of testosterone for amphioxus SR and elucidate the evolution of steroid-binding to nuclear receptors.
ALE3D Model Predictions and Materials Characterization for the Cookoff Response of PBXN-109
McClelland, M A; Maienschein, J L; Nichols, A L; Wardell, J F; Atwood, A I; Curran, P O
2002-03-19
ALE3D simulations are presented for the thermal explosion of PBXN-109 (RDX, AI, HTPB, DOA) in support of an effort by the U. S. Navy and Department of Energy (DOE) to validate computational models. The U.S. Navy is performing benchmark tests for the slow cookoff of PBXN-109 in a sealed tube. Candidate models are being tested using the ALE3D code, which can simulate the coupled thermal, mechanical, and chemical behavior during heating, ignition, and explosion. The strength behavior of the solid constituents is represented by a Steinberg-Guinan model while polynomial and gamma-law expressions are used for the Equation Of State (EOS) for the solid and gas species, respectively. A void model is employed to represent the air in gaps. ALE3D model 'parameters are specified using measurements of thermal and mechanical properties including thermal expansion, heat capacity, shear modulus, and bulk modulus. A standard three-step chemical kinetics model is used during the thermal ramp, and a pressure-dependent burn front model is employed during the rapid expansion. Parameters for the three-step kinetics model are specified using measurements of the One-Dimensional-Time-to-Explosion (ODTX), while measurements for burn rate of pristine and thermally damaged material are employed to determine parameters in the burn front model. Results are given for calculations in which heating, ignition, and explosion are modeled in a single simulation. We compare model results to measurements for the cookoff temperature and tube wall strain.
Air Pollution Modeling Using A 3-d Hemispheric Nested Model
NASA Astrophysics Data System (ADS)
Frohn, L. M.; Christensen, J. H.; Brandt, J.; Hertel, O.
A 3-D Eulerian transport-chemistry model based on modules and parameterisations from models developed over the last decade at the National Environmental Research Institute (DREAM, DEHM, ACDEP and DEOM) has been developed. The model is hemispheric with currently two nests implemented. The horizontal resolution in the mother domain is 150 km x 150 km. First nest covers the European area wit,h a 50 km x 50 km resolution, second covers the Scandinavian area with a resolution of 16.67 km x 16.67 km. The model employs a chemical scheme (originally 53 species) which has been modified to include a detailed description of the nitrogen chemistry. The concentration of air pollutants, such as sulfur and nitrogen in various forms, has been calculated with the model, applying no nesting as well as one and two nests. The calculated values have been validated by comparison to measurements from more than 200 EMEP monitoring stations. Furthermore deposition of nitrogen to marine waters has been estimated with the model. The goal is to obtain an improved description of spatial and temporal variations in the nutrient deposition to the marine environment. In the presentation the physics and chemistry of the model will be shortly described. Validations of the model calculations by comparison to EMEP measurements will be shown and discussed together with the results of the deposition calculations.
Parallel Optimization of 3D Cardiac Electrophysiological Model Using GPU.
Xia, Yong; Wang, Kuanquan; Zhang, Henggui
2015-01-01
Large-scale 3D virtual heart model simulations are highly demanding in computational resources. This imposes a big challenge to the traditional computation resources based on CPU environment, which already cannot meet the requirement of the whole computation demands or are not easily available due to expensive costs. GPU as a parallel computing environment therefore provides an alternative to solve the large-scale computational problems of whole heart modeling. In this study, using a 3D sheep atrial model as a test bed, we developed a GPU-based simulation algorithm to simulate the conduction of electrical excitation waves in the 3D atria. In the GPU algorithm, a multicellular tissue model was split into two components: one is the single cell model (ordinary differential equation) and the other is the diffusion term of the monodomain model (partial differential equation). Such a decoupling enabled realization of the GPU parallel algorithm. Furthermore, several optimization strategies were proposed based on the features of the virtual heart model, which enabled a 200-fold speedup as compared to a CPU implementation. In conclusion, an optimized GPU algorithm has been developed that provides an economic and powerful platform for 3D whole heart simulations.
Parallel Optimization of 3D Cardiac Electrophysiological Model Using GPU
Xia, Yong; Wang, Kuanquan; Zhang, Henggui
2015-01-01
Large-scale 3D virtual heart model simulations are highly demanding in computational resources. This imposes a big challenge to the traditional computation resources based on CPU environment, which already cannot meet the requirement of the whole computation demands or are not easily available due to expensive costs. GPU as a parallel computing environment therefore provides an alternative to solve the large-scale computational problems of whole heart modeling. In this study, using a 3D sheep atrial model as a test bed, we developed a GPU-based simulation algorithm to simulate the conduction of electrical excitation waves in the 3D atria. In the GPU algorithm, a multicellular tissue model was split into two components: one is the single cell model (ordinary differential equation) and the other is the diffusion term of the monodomain model (partial differential equation). Such a decoupling enabled realization of the GPU parallel algorithm. Furthermore, several optimization strategies were proposed based on the features of the virtual heart model, which enabled a 200-fold speedup as compared to a CPU implementation. In conclusion, an optimized GPU algorithm has been developed that provides an economic and powerful platform for 3D whole heart simulations. PMID:26581957
Geospatial Modelling Approach for 3d Urban Densification Developments
NASA Astrophysics Data System (ADS)
Koziatek, O.; Dragićević, S.; Li, S.
2016-06-01
With growing populations, economic pressures, and the need for sustainable practices, many urban regions are rapidly densifying developments in the vertical built dimension with mid- and high-rise buildings. The location of these buildings can be projected based on key factors that are attractive to urban planners, developers, and potential buyers. Current research in this area includes various modelling approaches, such as cellular automata and agent-based modelling, but the results are mostly linked to raster grids as the smallest spatial units that operate in two spatial dimensions. Therefore, the objective of this research is to develop a geospatial model that operates on irregular spatial tessellations to model mid- and high-rise buildings in three spatial dimensions (3D). The proposed model is based on the integration of GIS, fuzzy multi-criteria evaluation (MCE), and 3D GIS-based procedural modelling. Part of the City of Surrey, within the Metro Vancouver Region, Canada, has been used to present the simulations of the generated 3D building objects. The proposed 3D modelling approach was developed using ESRI's CityEngine software and the Computer Generated Architecture (CGA) language.
3D Model Generation From the Engineering Drawing
NASA Astrophysics Data System (ADS)
Vaský, Jozef; Eliáš, Michal; Bezák, Pavol; Červeňanská, Zuzana; Izakovič, Ladislav
2010-01-01
The contribution deals with the transformation of engineering drawings in a paper form into a 3D computer representation. A 3D computer model can be further processed in CAD/CAM system, it can be modified, archived, and a technical drawing can be then generated from it as well. The transformation process from paper form to the data one is a complex and difficult one, particularly owing to the different types of drawings, forms of displayed objects and encountered errors and deviations from technical standards. The algorithm for 3D model generating from an orthogonal vector input representing a simplified technical drawing of the rotational part is described in this contribution. The algorithm was experimentally implemented as ObjectARX application in the AutoCAD system and the test sample as the representation of the rotational part was used for verificaton.
Space Partitioning for Privacy Enabled 3D City Models
NASA Astrophysics Data System (ADS)
Filippovska, Y.; Wichmann, A.; Kada, M.
2016-10-01
Due to recent technological progress, data capturing and processing of highly detailed (3D) data has become extensive. And despite all prospects of potential uses, data that includes personal living spaces and public buildings can also be considered as a serious intrusion into people's privacy and a threat to security. It becomes especially critical if data is visible by the general public. Thus, a compromise is needed between open access to data and privacy requirements which can be very different for each application. As privacy is a complex and versatile topic, the focus of this work particularly lies on the visualization of 3D urban data sets. For the purpose of privacy enabled visualizations of 3D city models, we propose to partition the (living) spaces into privacy regions, each featuring its own level of anonymity. Within each region, the depicted 2D and 3D geometry and imagery is anonymized with cartographic generalization techniques. The underlying spatial partitioning is realized as a 2D map generated as a straight skeleton of the open space between buildings. The resulting privacy cells are then merged according to the privacy requirements associated with each building to form larger regions, their borderlines smoothed, and transition zones established between privacy regions to have a harmonious visual appearance. It is exemplarily demonstrated how the proposed method generates privacy enabled 3D city models.
3-D world modeling for an autonomous robot
Goldstein, M.; Pin, F.G.; Weisbin, C.R.
1987-08-01
This paper presents a methodology for a concise representation of the 3-D world model for a mobile robot, using range data. The process starts with the segmentation of the scene into ''objects'' that are given a unique label, based on principles of range continuity. Then the external surface of each object is partitioned into homogeneous surface patches. Contours of surface patches in 3-D space are identified by estimating the normal and curvature associated with each pixel. The resulting surface patches are then classified as planar, convex or concave. Since the world model uses a volumetric representation for the 3-D environment, planar surfaces are represented by thin volumetric polyhedra. Spherical and cylindrical surfaces are extracted and represented by appropriate volumetric primitives. All other surfaces are represented using the boolean union of spherical volumes (as described in a separate paper by the same authors). The result is a general, concise representation of the external 3-D world, which allows for efficient and robust 3-D object recognition. 20 refs., 14 figs.
Coronal roots of solar wind streams: 3-D MHD modeling
NASA Technical Reports Server (NTRS)
Pisanko, Yu. V.
1995-01-01
Weak (discontinuous) solutions of the 3-D MHD equations look like a promising tool to model the transonic solar wind with structural elements: current sheets, coronal plumes etc. Using the observational information about various coronal emissions one can include these structural elements into the 3-D MHD solar wind model by embedding the discontinuities of given type. Such 3-D MHD structured solar wind is calculated self-consistently: variants are examined via numerical experiments. In particular, the behavior of coronal plumes in the transonic solar wind flow, is modeled. The input information for numerical modeling (for example, the magnetic field map at the very base of the solar corona) can be adjusted so that fast stream arises over the center of the coronal hole, over the coronal hole boundaries and, even, over the region with closed magnetic topology. 3-D MHD equations have the analytical solution which can serve as a model of supersonic trans-alfvenic solar wind in the (5-20) solar radii heliocentric distance interval. The transverse, nonradial total (gas + magnetic field) pressure balance in the flow is the corner-stone of this solution. The solution describes the filamentation (ray-like structure of the solar corona) and streaming (formation of high-speed streams with velocities up to 800 km/sec) as a consequence of the magnetic field spatial inhomogeneous structure and trans-alfvenic character of the flow. The magnetic field works in the model as a 'controller' for the solar wind streaming and filamentation.
3D modeling of dual-gate FinFET.
Mil'shtein, Samson; Devarakonda, Lalitha; Zanchi, Brian; Palma, John
2012-11-13
The tendency to have better control of the flow of electrons in a channel of field-effect transistors (FETs) did lead to the design of two gates in junction field-effect transistors, field plates in a variety of metal semiconductor field-effect transistors and high electron mobility transistors, and finally a gate wrapping around three sides of a narrow fin-shaped channel in a FinFET. With the enhanced control, performance trends of all FETs are still challenged by carrier mobility dependence on the strengths of the electrical field along the channel. However, in cases when the ratio of FinFET volume to its surface dramatically decreases, one should carefully consider the surface boundary conditions of the device. Moreover, the inherent non-planar nature of a FinFET demands 3D modeling for accurate analysis of the device performance. Using the Silvaco modeling tool with quantization effects, we modeled a physical FinFET described in the work of Hisamoto et al. (IEEE Tran. Elec. Devices 47:12, 2000) in 3D. We compared it with a 2D model of the same device. We demonstrated that 3D modeling produces more accurate results. As 3D modeling results came close to experimental measurements, we made the next step of the study by designing a dual-gate FinFET biased at Vg1 >Vg2. It is shown that the dual-gate FinFET carries higher transconductance than the single-gate device.
3D shape decomposition and comparison for gallbladder modeling
NASA Astrophysics Data System (ADS)
Huang, Weimin; Zhou, Jiayin; Liu, Jiang; Zhang, Jing; Yang, Tao; Su, Yi; Law, Gim Han; Chui, Chee Kong; Chang, Stephen
2011-03-01
This paper presents an approach to gallbladder shape comparison by using 3D shape modeling and decomposition. The gallbladder models can be used for shape anomaly analysis and model comparison and selection in image guided robotic surgical training, especially for laparoscopic cholecystectomy simulation. The 3D shape of a gallbladder is first represented as a surface model, reconstructed from the contours segmented in CT data by a scheme of propagation based voxel learning and classification. To better extract the shape feature, the surface mesh is further down-sampled by a decimation filter and smoothed by a Taubin algorithm, followed by applying an advancing front algorithm to further enhance the regularity of the mesh. Multi-scale curvatures are then computed on the regularized mesh for the robust saliency landmark localization on the surface. The shape decomposition is proposed based on the saliency landmarks and the concavity, measured by the distance from the surface point to the convex hull. With a given tolerance the 3D shape can be decomposed and represented as 3D ellipsoids, which reveal the shape topology and anomaly of a gallbladder. The features based on the decomposed shape model are proposed for gallbladder shape comparison, which can be used for new model selection. We have collected 19 sets of abdominal CT scan data with gallbladders, some shown in normal shape and some in abnormal shapes. The experiments have shown that the decomposed shapes reveal important topology features.
Enhanced visualization of angiograms using 3D models
NASA Astrophysics Data System (ADS)
Marovic, Branko S.; Duckwiler, Gary R.; Villablanca, Pablo; Valentino, Daniel J.
1999-05-01
The 3D visualization of intracranial vasculature can facilitate the planning of endovascular therapy and the evaluation of interventional result. To create 3D visualizations, volumetric datasets from x-ray computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are commonly rendered using maximum intensity projection (MIP), volume rendering, or surface rendering techniques. However, small aneurysms and mild stenoses are very difficult to detect using these methods. Furthermore, the instruments used during endovascular embolization or surgical treatment produce artifacts that typically make post-intervention CTA inapplicable, and the presence of magnetic material prohibits the use of MRA. Therefore, standard digital angiography is typically used. In order to address these problems, we developed a visualization and modeling system that displays 2D and 3D angiographic images using a simple Web-based interface. Polygonal models of vasculature were generated from CT and MR data using 3D segmentation of bones and vessels and polygonal surface extraction and simplification. A web-based 3D environment was developed for interactive examination of reconstructed surface models, creation of oblique cross- sections and maximum intensity projections, and distance measurements and annotations. This environment uses a multi- tier client/server approach employing VRML and Java. The 3D surface model and angiographic images can be aligned and displayed simultaneously to permit better perception of complex vasculature and to determine optical viewing positions and angles before starting an angiographic sessions. Polygonal surface reconstruction allows interactive display of complex spatial structures on inexpensive platforms such as personal computers as well as graphic workstations. The aneurysm assessment procedure demonstrated the utility of web-based technology for clinical visualization. The resulting system facilitated the treatment of serious vascular
Induction Heating Process: 3D Modeling and Optimisation
NASA Astrophysics Data System (ADS)
Naar, R.; Bay, F.
2011-05-01
An increasing number of problems in mechanics and physics involves multiphysics coupled problems. Among these problems, we can often find electromagnetic coupled problems. Electromagnetic couplings may be involved through the use of direct or induced currents for thermal purposes—in order to generate heat inside a work piece in order to get either a prescribed temperature field or some given mechanical or metallurgical properties through an accurate control of temperature evolution with respect to time-, or for solid or fluid mechanics purposes—in order to create magnetic forces such as in fluid mechanics (electromagnetic stirring,…) or solid mechanics (magnetoforming,…). Induction heat treatment processes is therefore quite difficult to control; trying for instance to minimize distortions generated by such a process is not easy. In order to achieve these objectives, we have developed a computational tool which includes an optimsation stage. A 3D finite element modeling tool for local quenching after induction heating processes has already been developed in our laboratory. The modeling of such a multiphysics coupled process needs taking into account electromagnetic, thermal, mechanical and metallurgical phenomenon—as well as their mutual interactions during the whole process: heating and quenching. The model developed is based on Maxwell equations, heat transfer equation, mechanical equilibrium computations, Johnson-Mehl-Avrami and Koistinen-Marburger laws. All these equations and laws may be coupled but some coupling may be neglected. In our study, we will also focus on induction heating process aiming at optimising the Heat Affected Zone (HAZ). Thus problem is formalized as an optimization problem—minimizing a cost function which measures the difference between computed and optimal temperatures—along with some constraints on process parameters. The optimization algorithms may be of two kinds—either zero-order or first-order algorithms. First
3-D QSAutogrid/R: an alternative procedure to build 3-D QSAR models. Methodologies and applications.
Ballante, Flavio; Ragno, Rino
2012-06-25
Since it first appeared in 1988 3-D QSAR has proved its potential in the field of drug design and activity prediction. Although thousands of citations now exist in 3-D QSAR, its development was rather slow with the majority of new 3-D QSAR applications just extensions of CoMFA. An alternative way to build 3-D QSAR models, based on an evolution of software, has been named 3-D QSAutogrid/R and has been developed to use only software freely available to academics. 3-D QSAutogrid/R covers all the main features of CoMFA and GRID/GOLPE with implementation by multiprobe/multiregion variable selection (MPGRS) that improves the simplification of interpretation of the 3-D QSAR map. The methodology is based on the integration of the molecular interaction fields as calculated by AutoGrid and the R statistical environment that can be easily coupled with many free graphical molecular interfaces such as UCSF-Chimera, AutoDock Tools, JMol, and others. The description of each R package is reported in detail, and, to assess its validity, 3-D QSAutogrid/R has been applied to three molecular data sets of which either CoMFA or GRID/GOLPE models were reported in order to compare the results. 3-D QSAutogrid/R has been used as the core engine to prepare more that 240 3-D QSAR models forming the very first 3-D QSAR server ( www.3d-qsar.com ) with its code freely available through R-Cran distribution.
NASA Astrophysics Data System (ADS)
Sharkawi, K.-H.; Abdul-Rahman, A.
2013-09-01
Cities and urban areas entities such as building structures are becoming more complex as the modern human civilizations continue to evolve. The ability to plan and manage every territory especially the urban areas is very important to every government in the world. Planning and managing cities and urban areas based on printed maps and 2D data are getting insufficient and inefficient to cope with the complexity of the new developments in big cities. The emergence of 3D city models have boosted the efficiency in analysing and managing urban areas as the 3D data are proven to represent the real world object more accurately. It has since been adopted as the new trend in buildings and urban management and planning applications. Nowadays, many countries around the world have been generating virtual 3D representation of their major cities. The growing interest in improving the usability of 3D city models has resulted in the development of various tools for analysis based on the 3D city models. Today, 3D city models are generated for various purposes such as for tourism, location-based services, disaster management and urban planning. Meanwhile, modelling 3D objects are getting easier with the emergence of the user-friendly tools for 3D modelling available in the market. Generating 3D buildings with high accuracy also has become easier with the availability of airborne Lidar and terrestrial laser scanning equipments. The availability and accessibility to this technology makes it more sensible to analyse buildings in urban areas using 3D data as it accurately represent the real world objects. The Open Geospatial Consortium (OGC) has accepted CityGML specifications as one of the international standards for representing and exchanging spatial data, making it easier to visualize, store and manage 3D city models data efficiently. CityGML able to represents the semantics, geometry, topology and appearance of 3D city models in five well-defined Level-of-Details (LoD), namely LoD0
Understanding thermal Marangoni flow in water sessile evaporating drops via 3D-PTV
NASA Astrophysics Data System (ADS)
Rossi, Massimiliano; Marin, Alvaro; Kaehler, Christian J.
2016-11-01
Understanding the flow inside sessile evaporating drops is of great interest both from a fundamental and technological point of view. Despite strong research efforts in the recent years, a complete picture on the phenomena involved in this process and a way to control them is still far to be reached. This is due to a lack of reliable experimental data on the internal flow but more dramatically on the interfacial flow. A relevant open debate concerns the role played by the Marangoni flow induced by thermal gradients. We recently show how 3D particle tracking techniques are suitable to measure the internal flow of drops and to derive quantities such as surface shear and surface tension differences. Such experiments also indicated an increase of the thermal Marangoni flow as the droplet becomes thinner, in disagreement with current theoretical models and simulations. A possible reason for that could be a discrepancy of the imposed boundary conditions in the simulations and the experimental ones. This work follows up these observations with fully 3D time-resolved measurements of the flow inside drops evaporating on a quartz substrate, which temperature is controlled using a feedback temperature control and a microscope incubator system. Supported by DFG, Grant No. KA 1808/22.
Enhanced LOD Concepts for Virtual 3d City Models
NASA Astrophysics Data System (ADS)
Benner, J.; Geiger, A.; Gröger, G.; Häfele, K.-H.; Löwner, M.-O.
2013-09-01
Virtual 3D city models contain digital three dimensional representations of city objects like buildings, streets or technical infrastructure. Because size and complexity of these models continuously grow, a Level of Detail (LoD) concept effectively supporting the partitioning of a complete model into alternative models of different complexity and providing metadata, addressing informational content, complexity and quality of each alternative model is indispensable. After a short overview on various LoD concepts, this paper discusses the existing LoD concept of the CityGML standard for 3D city models and identifies a number of deficits. Based on this analysis, an alternative concept is developed and illustrated with several examples. It differentiates between first, a Geometric Level of Detail (GLoD) and a Semantic Level of Detail (SLoD), and second between the interior building and its exterior shell. Finally, a possible implementation of the new concept is demonstrated by means of an UML model.
Teaching the geological subsurface with 3D models
NASA Astrophysics Data System (ADS)
Thorpe, Steve; Ward, Emma
2014-05-01
3D geological models have great potential as a resource when teaching geological concepts as it allows the student to visualise and interrogate UK geology. They are especially useful when dealing with the conversion of 2D field, map and GIS outputs into three dimensional geological units, which is a common problem for many students. Today's earth science students use a variety of skills and processes during their learning experience including spatial thinking, image construction, detecting patterns, making predictions and deducing the orientation of themselves. 3D geological models can reinforce spatial thinking strategies and encourage students to think about processes and properties, in turn helping the student to recognise pre-learnt geological principles in the field and to convert what they see at the surface into a picture of what is going on at depth. The British Geological Survey (BGS) has been producing digital 3D geological models for over 10 years. The models produced are revolutionising the working practices, data standards and products of the BGS. Sharing our geoscience information with academia is highlighted throughout the BGS strategy as is instilling practical skills in future geoscience professionals, such as model building and interpretation. In 2009 a project was launched to investigate the potential of the models as a teaching resource. The study included justifying if and how the models help students to learn, how models have been used historically, and how other forms of modelling are being used today. BGS now produce 3D geological models for use by anyone teaching or learning geoscience. They incorporate educational strategies that will develop geospatial skills and alleviate potential problems that some students experience. They are contained within contemporary case studies and show standard geological concepts, structures, sedimentary rocks, cross sections and field techniques. 3D geological models of the Isle of Wight and Ingleborough
Modeling the Properties of 3D Woven Composites
NASA Technical Reports Server (NTRS)
Cox, Brian N.
1995-01-01
An extensive study has been completed of the internal geometry, the mechanisms of failure, and the micromechanics of local failure events in graphite/epoxy composites with three dimensional (3D) woven reinforcement. This work has led to the development of models for predicting elastic constants, strength, notch sensitivity, and fatigue life. A summary is presented here.
Performance and Cognitive Assessment in 3-D Modeling
ERIC Educational Resources Information Center
Fahrer, Nolan E.; Ernst, Jeremy V.; Branoff, Theodore J.; Clark, Aaron C.
2011-01-01
The purpose of this study was to investigate identifiable differences between performance and cognitive assessment scores in a 3-D modeling unit of an engineering drafting course curriculum. The study aimed to provide further investigation of the need of skill-based assessments in engineering/technical graphics courses to potentially increase…
Coarse-grained modeling of RNA 3D structure.
Dawson, Wayne K; Maciejczyk, Maciej; Jankowska, Elzbieta J; Bujnicki, Janusz M
2016-07-01
Functional RNA molecules depend on three-dimensional (3D) structures to carry out their tasks within the cell. Understanding how these molecules interact to carry out their biological roles requires a detailed knowledge of RNA 3D structure and dynamics as well as thermodynamics, which strongly governs the folding of RNA and RNA-RNA interactions as well as a host of other interactions within the cellular environment. Experimental determination of these properties is difficult, and various computational methods have been developed to model the folding of RNA 3D structures and their interactions with other molecules. However, computational methods also have their limitations, especially when the biological effects demand computation of the dynamics beyond a few hundred nanoseconds. For the researcher confronted with such challenges, a more amenable approach is to resort to coarse-grained modeling to reduce the number of data points and computational demand to a more tractable size, while sacrificing as little critical information as possible. This review presents an introduction to the topic of coarse-grained modeling of RNA 3D structures and dynamics, covering both high- and low-resolution strategies. We discuss how physics-based approaches compare with knowledge based methods that rely on databases of information. In the course of this review, we discuss important aspects in the reasoning process behind building different models and the goals and pitfalls that can result.
Assessment of 3D Models Used in Contours Studies
ERIC Educational Resources Information Center
Alvarez, F. J. Ayala; Parra, E. B. Blazquez; Tubio, F. Montes
2015-01-01
This paper presents an experimental research focusing on the view of first year students. The aim is to check the quality of implementing 3D models integrated in the curriculum. We search to determine students' preference between the various means facilitated in order to understand the given subject. Students have been respondents to prove the…
Tracking people and cars using 3D modeling and CCTV.
Edelman, Gerda; Bijhold, Jurrien
2010-10-10
The aim of this study was to find a method for the reconstruction of movements of people and cars using CCTV footage and a 3D model of the environment. A procedure is proposed, in which video streams are synchronized and displayed in a 3D model, by using virtual cameras. People and cars are represented by cylinders and boxes, which are moved in the 3D model, according to their movements as shown in the video streams. The procedure was developed and tested in an experimental setup with test persons who logged their GPS coordinates as a recording of the ground truth. Results showed that it is possible to implement this procedure and to reconstruct movements of people and cars from video recordings. The procedure was also applied to a forensic case. In this work we experienced that more situational awareness was created by the 3D model, which made it easier to track people on multiple video streams. Based on all experiences from the experimental set up and the case, recommendations are formulated for use in practice.
Robust 3D reconstruction system for human jaw modeling
NASA Astrophysics Data System (ADS)
Yamany, Sameh M.; Farag, Aly A.; Tazman, David; Farman, Allan G.
1999-03-01
This paper presents a model-based vision system for dentistry that will replace traditional approaches used in diagnosis, treatment planning and surgical simulation. Dentistry requires accurate 3D representation of the teeth and jaws for many diagnostic and treatment purposes. For example orthodontic treatment involves the application of force systems to teeth over time to correct malocclusion. In order to evaluate tooth movement progress, the orthodontists monitors this movement by means of visual inspection, intraoral measurements, fabrication of plastic models, photographs and radiographs, a process which is both costly and time consuming. In this paper an integrate system has been developed to record the patient's occlusion using computer vision. Data is acquired with an intraoral video camera. A modified shape from shading (SFS) technique, using perspective projection and camera calibration, is used to extract accurate 3D information from a sequence of 2D images of the jaw. A new technique for 3D data registration, using a Grid Closest Point transform and genetic algorithms, is used to register the SFS output. Triangulization is then performed, and a solid 3D model is obtained via a rapid prototype machine.
High Rayleigh Number 3d Spherical Mantle Convection Models
NASA Astrophysics Data System (ADS)
Davies, J. H.
2003-04-01
The geochemical and geophysical evidence related to the mantle can potentially be reconciled by a hypothesis of whole mantle convection where the heterogeneity stems from the continuous recycling of oceanic crust, depleted lithospheric mantle and sediments. The mantle is expected to be well but not perfectly stirred, sampled differently in different tectonic settings, and with components having wide-ranging residence times. We might for example expect very long residence times for some buoyant or dense components that can reside in either the upper (lithosphere) or lower boundary (D''). We have started testing whether such a whole mantle convection hypothesis can satisfy wide ranging first order geophysical observations, such as plate velocities, stability of upwellings, geometry of downwellings, etc. The model parameters, including the mantle's viscosity structure, are guided by extensive earlier community work. We use TERRA to model compressible convection in a 3D spherical mantle shell with a depth dependent viscosity structure, where the lower mantle is 40 times more viscous than the upper mantle. A chondritic rate of internal heating of 6 x 10^-12 W/Kg was assumed, leading to Ra(H) = 3.4x10^8. A realistic depth dependent thermal expansivity and Murnaghan equation of state was assumed, with free slip b.c.. The evolution of the system was followed for 2 Billion years. The RMS surface velocity varied from around 4 - 7cm/yr, very similar to recent plate velocities. The structures in the lower mantle are relatively stable and larger length scale in comparison to the upper mantle features. The downwellings and upwellings are linear in planform but the upwellings are dominated by stronger upflow at the columns formed at their intersection. The upwelling features embedded in the lower mantle are very stable, and it is reasonable to expect (though yet to be demonstrated) that with temperature-dependent viscosity the upwellings will be dominated by the cylindrical
3D Geological modelling - towards a European level infrastructure
NASA Astrophysics Data System (ADS)
Lee, Kathryn A.; van der Krogt, Rob; Busschers, Freek S.
2013-04-01
The joint European Geological Surveys are preparing the ground for a "European Geological Data Infrastructure" (EGDI), under the framework of the FP7-project EGDI-Scope. This scoping study, started in June 2012, for a pan-European e-Infrastructure is based on the successes of earlier joint projects including 'OneGeology-Europe' and aims to provide the backbone for serving interoperable, geological data currently held by European Geological Surveys. Also data from past, ongoing and future European projects will be incorporated. The scope will include an investigation of the functional and technical requirements for serving 3D geological models and will look to research the potential for providing a framework to integrate models at different scales, and form a structure for enabling the development of new and innovative model delivery mechanisms. The EGDI-scope project encourages pan-European inter-disciplinary collaboration between all European Geological Surveys. It aims to enhance emerging web based technologies that will facilitate the delivery of geological data to user communities involved in European policy making and international industry, but also to geoscientific research communities and the general public. Therefore, stakeholder input and communication is imperative to the success, as is the collaboration with all the Geological Surveys of Europe. The most important functional and technical requirements for delivery of such information at pan-European level will be derived from exchanges with relevant European stakeholder representatives and providers of geological data. For handling and delivering 3D geological model data the project will need to address a number of strategic issues: • Which are the most important issues and queries for the relevant stakeholders, requiring 3D geological models? How can this be translated to functional requirements for development and design of an integrated European application? • How to handle the very large
Quasi-3D Multi-scale Modeling Framework Development
NASA Astrophysics Data System (ADS)
Arakawa, A.; Jung, J.
2008-12-01
When models are truncated in or near an energetically active range of the spectrum, model physics must be changed as the resolution changes. The model physics of GCMs and that of CRMs are, however, quite different from each other and at present there is no unified formulation of model physics that automatically provides transition between these model physics. The Quasi-3D (Q3D) Multi-scale Modeling Framework (MMF) is an attempt to bridge this gap. Like the recently proposed Heterogeneous Multiscale Method (HMM) (E and Engquist 2003), MMF combines a macroscopic model, GCM, and a microscopic model, CRM. Unlike the traditional multiscale methods such as the multi-grid and adapted mesh refinement techniques, HMM and MMF are for solving multi-physics problems. They share the common objective "to design combined macroscopic-microscopic computational methods that are much more efficient than solving the full microscopic model and at the same time give the information we need" (E et al. 2008). The question is then how to meet this objective in practice, which can be highly problem dependent. In HHM, the efficiency is gained typically by localization of the microscale problem. Following the pioneering work by Grabowski and Smolarkiewicz (1999) and Grabowski (2001), MMF takes advantage of the fact that 2D CRMs are reasonably successful in simulating deep clouds. In this approach, the efficiency is gained by sacrificing the three-dimensionality of cloud-scale motion. It also "localizes" the algorithm through embedding a CRM in each GCM grid box using cyclic boundary condition. The Q3D MMF is an attempt to reduce the expense due to these constraints by partially including the cloud-scale 3D effects and extending the CRM beyond individual GCM grid boxes. As currently formulated, the Q3D MMF is a 4D estimation/prediction framework that combines a GCM with a 3D anelastic cloud-resolving vector vorticity equation model (VVM) applied to a network of horizontal grids. The network
High-Density 3D-Boron Nitride and 3D-Graphene for High-Performance Nano-Thermal Interface Material.
Loeblein, Manuela; Tsang, Siu Hon; Pawlik, Matthieu; Phua, Eric Jian Rong; Yong, Han; Zhang, Xiao Wu; Gan, Chee Lip; Teo, Edwin Hang Tong
2017-02-28
Compression studies on three-dimensional foam-like graphene and h-BN (3D-C and 3D-BN) revealed their high cross-plane thermal conductivity (62-86 W m(-1) K(-1)) and excellent surface conformity, characteristics essential for thermal management needs. Comparative studies to state-of-the-art materials and other materials currently under research for heat dissipation revealed 3D-foam's improved performance (20-30% improved cooling, temperature decrease by ΔT of 44-24 °C).
NASA Astrophysics Data System (ADS)
Di Renzo, Valeria; Wohletz, Kenneth; Civetta, Lucia; Moretti, Roberto; Orsi, Giovanni; Gasparini, Paolo
2016-12-01
We illustrate a quantitative conductive/convective thermal model incorporating a wide range of geophysical, petrological, geological, geochemical and isotopical observations that constrain the thermal evolution and present state of the Campi Flegrei caldera (CFc) magmatic system. The proposed model has been computed on the basis of the current knowledge of: (1) the volcanic and magmatic history of the volcano over the last 44 ka, (2) its underlying crustal structure, and (3) the physical properties of the erupted magmas. 3D numerical simulations of heat conduction and convection within heterogeneous rock/magma materials with evolving heat sources and boundary conditions that simulate magma rise from a deep (≥ 8 km depth) to shallow (2-6 km) reservoirs, magma chamber formation, magma extrusion, caldera collapse, and intra-caldera hydrothermal convection, have been carried out. The evolution of the CFc magmatic system through time has been simulated through different steps related to its changes in terms of depth, location and size of magma reservoirs and their replenishment. The thermal modeling results show that both heat conduction and convection have played an important role in the CFc thermal evolution, although with different timing. The simulated present heat distribution is in agreement with the measured geothermal profiles (Agip, 1987), reproduces the thermal gradient peaks at the CFc margins in correspondence to the anomalies in surface gradients (Corrado et al., 1998), and suggests temperatures of 700 °C at depth of 4 km in the central portion of the caldera, in agreement with the estimated temperature for the brittle-ductile transition (Hill, 1992).
Grid cells in 3-D: Reconciling data and models.
Horiuchi, Timothy K; Moss, Cynthia F
2015-12-01
It is well documented that place cells and grid cells in echolocating bats show properties similar to those described in rodents, and yet, continuous theta-frequency oscillations, proposed to play a central role in grid/place cell formation, are not present in bat recordings. These comparative neurophysiological data have raised many questions about the role of theta-frequency oscillations in spatial memory and navigation. Additionally, spatial navigation in three-dimensions poses new challenges for the representation of space in neural models. Inspired by the literature on space representation in the echolocating bat, we have developed a nonoscillatory model of 3-D grid cell creation that shares many of the features of existing oscillatory-interference models. We discuss the model in the context of current knowledge of 3-D space representation and highlight directions for future research.
RNA and protein 3D structure modeling: similarities and differences.
Rother, Kristian; Rother, Magdalena; Boniecki, Michał; Puton, Tomasz; Bujnicki, Janusz M
2011-09-01
In analogy to proteins, the function of RNA depends on its structure and dynamics, which are encoded in the linear sequence. While there are numerous methods for computational prediction of protein 3D structure from sequence, there have been very few such methods for RNA. This review discusses template-based and template-free approaches for macromolecular structure prediction, with special emphasis on comparison between the already tried-and-tested methods for protein structure modeling and the very recently developed "protein-like" modeling methods for RNA. We highlight analogies between many successful methods for modeling of these two types of biological macromolecules and argue that RNA 3D structure can be modeled using "protein-like" methodology. We also highlight the areas where the differences between RNA and proteins require the development of RNA-specific solutions.
Stereoscopic display of 3D models for design visualization
NASA Astrophysics Data System (ADS)
Gilson, Kevin J.
2006-02-01
Advances in display technology and 3D design visualization applications have made real-time stereoscopic visualization of architectural and engineering projects a reality. Parsons Brinkerhoff (PB) is a transportation consulting firm that has used digital visualization tools from their inception and has helped pioneer the application of those tools to large scale infrastructure projects. PB is one of the first Architecture/Engineering/Construction (AEC) firms to implement a CAVE- an immersive presentation environment that includes stereoscopic rear-projection capability. The firm also employs a portable stereoscopic front-projection system, and shutter-glass systems for smaller groups. PB is using commercial real-time 3D applications in combination with traditional 3D modeling programs to visualize and present large AEC projects to planners, clients and decision makers in stereo. These presentations create more immersive and spatially realistic presentations of the proposed designs. This paper will present the basic display tools and applications, and the 3D modeling techniques PB is using to produce interactive stereoscopic content. The paper will discuss several architectural and engineering design visualizations we have produced.
Parallel 3-D viscoelastic finite difference seismic modelling
NASA Astrophysics Data System (ADS)
Bohlen, Thomas
2002-10-01
Computational power has advanced to a state where we can begin to perform wavefield simulations for realistic (complex) 3-D earth models at frequencies of interest to both seismologists and engineers. On serial platforms, however, 3-D calculations are still limited to small grid sizes and short seismic wave traveltimes. To make use of the efficiency of network computers a parallel 3-D viscoelastic finite difference (FD) code is implemented which allows to distribute the work on several PCs or workstations connected via standard ethernet in an in-house network. By using the portable message passing interface standard (MPI) for the communication between processors, running times can be reduced and grid sizes can be increased significantly. Furthermore, the code shows good performance on massive parallel supercomputers which makes the computation of very large grids feasible. This implementation greatly expands the applicability of the 3-D elastic/viscoelastic finite-difference modelling technique by providing an efficient, portable and practical C-program.
Development of 3D Woven Ablative Thermal Protection Systems (TPS) for NASA Spacecraft
NASA Technical Reports Server (NTRS)
Feldman, Jay D.; Ellerby, Don; Stackpoole, Mairead; Peterson, Keith; Venkatapathy, Ethiraj
2015-01-01
The development of a new class of thermal protection system (TPS) materials known as 3D Woven TPS led by the Entry Systems and Technology Division of NASA Ames Research Center (ARC) will be discussed. This effort utilizes 3D weaving and resin infusion technologies to produce heat shield materials that are engineered and optimized for specific missions and requirements. A wide range of architectures and compositions have been produced and preliminarily tested to prove the viability and tailorability of the 3D weaving approach to TPS.
Modeling of 3D Woven Composites Containing Multiple Delaminations
2012-08-20
researchers 3D woven composites shows better damage tolerance than laminated textile composites without z-yarns such as plain woven composites even...modeling of quasi-static short beam shear test of plain woven laminated composites. Cohesive elements were used in regions where transverse cracks and...Title ABSTRACT In this paper we present FE modeling of quasi-static short beam shear test of plain woven laminated composites. Cohesive elements were
3D coexisting modes of thermal convection in the faulted Lower Yarmouk Gorge
NASA Astrophysics Data System (ADS)
Magri, Fabien; Inbar, Nimrod; Möller, Peter; Raggad, Marwan; Rödiger, Tino; Rosenthal, Eliyahu; Siebert, Christian
2016-04-01
Numerical investigations of 3D modes of large-scale convection in faulted aquifers are presented with the aim to infer possible transport mechanisms supporting the formation of thermal springs in the Lower Yarmouk Gorge (LYG), at the border between Israel and Jordan. The transient finite elements models are based on a geological model of the LYG that introduces more realistic structural features of the basin, compared to previous existing models of the area (Magri et al., submitted). The sensitivity analysis of the fault permeability showed that faults cross-cutting the main regional flow direction allow groundwater to be driven laterally by convective forces within the fault planes. Therein thermal waters can either discharge along the fault traces or exit the fault through adjacent permeable aquifers. The location of springs can migrate with time, is not strictly constrained to the damage zones and reflects the interplay between the wavelength of the multicellular regime in the fault zone and the regional flow toward discharge areas in the lowlands. The results presented here suggest that in the LYG case, crossing flow paths result from the coexistence of fault convection, that can develop for example along NE-SW oriented faults within the Gorge, and additional flow fields that can be induced either by topography N-S gradients, e.g. perpendicular to the major axe of the Gorge, or by local thermal convection in permeable aquifers below Eocene aquiclude. The sensitivity analysis is consistent with the analytical solutions based on viscous-dependent Rayleigh theory. It indicates that in the LYG coexisting transport processes likely occur at fault hydraulic conductivity ranging between 2.3e-7 m/s and 9.3e- 7 m/s (i.e. 7 m/yr and 30 m/yr). The LYG numerical example and the associated Rayleigh analysis can be applied to study the onset of thermal convection and resulting flow patterns of any fractured hydrothermal basin. References Magri F, Möller S, Inbar N, M
Anisotropic thermal expansion of a 3D metal–organic framework with hydrophilic and hydrophobic pores
Kondo, Atsushi Maeda, Kazuyuki
2015-01-15
A 3D flexible metal–organic framework (MOF) with 1D hydrophilic and hydrophobic pores shows anisotropic thermal expansion with relatively large thermal expansion coefficient (α{sub a}=−21×10{sup −6} K{sup −1} and α{sub c}=79×10{sup −6} K{sup −1}) between 133 K and 383 K. Temperature change gives deformation of both pores, which expand in diameter and elongate in length on cooling and vice versa. The thermally induced structural change should be derived from a unique framework topology like “lattice fence”. Silica accommodation changes not only the nature of the MOF but also thermal responsiveness of the MOF. Since the hydrophobic pores in the material are selectively blocked by the silica, the MOF with the silica is considered as a hydrophilic microporous material. Furthermore, inclusion of silica resulted in a drastic pore contraction in diameter and anisotropically changed the thermal responsiveness of the MOF. - Graphical abstract: A 3D metal–organic framework with hydrophilic and hydrophobic pores shows anisotropic thermal expansion behavior. The influence of silica filler in the hydrophobic pore was investigated. - Highlights: • Thermally induced structural change of a 3D MOF with a lattice fence topology was investigated. • The structural change was analyzed by synchrotron X-ray diffraction patterns. • Temperature change induces anisotropic thermal expansion/contraction of the MOF. • Silica inclusion anisotropically changes the thermal responsiveness of the MOF.
Geometric and Colour Data Fusion for Outdoor 3D Models
Merchán, Pilar; Adán, Antonio; Salamanca, Santiago; Domínguez, Vicente; Chacón, Ricardo
2012-01-01
This paper deals with the generation of accurate, dense and coloured 3D models of outdoor scenarios from scanners. This is a challenging research field in which several problems still remain unsolved. In particular, the process of 3D model creation in outdoor scenes may be inefficient if the scene is digitalized under unsuitable technical (specific scanner on-board camera) and environmental (rain, dampness, changing illumination) conditions. We address our research towards the integration of images and range data to produce photorealistic models. Our proposal is based on decoupling the colour integration and geometry reconstruction stages, making them independent and controlled processes. This issue is approached from two different viewpoints. On the one hand, given a complete model (geometry plus texture), we propose a method to modify the original texture provided by the scanner on-board camera with the colour information extracted from external images taken at given moments and under specific environmental conditions. On the other hand, we propose an algorithm to directly assign external images onto the complete geometric model, thus avoiding tedious on-line calibration processes. We present the work conducted on two large Roman archaeological sites dating from the first century A.D., namely, the Theatre of Segobriga and the Fori Porticus of Emerita Augusta, both in Spain. The results obtained demonstrate that our approach could be useful in the digitalization and 3D modelling fields. PMID:22969327
A method for building 3D models of barchan dunes
NASA Astrophysics Data System (ADS)
Nai, Yang; Li-lan, Su; Lin, Wan; Jie, Yang; Shi-yi, Chen; Wei-lu, Hu
2016-01-01
The distributions of barchan dunes are usually represented by digital terrain models (DTMs) overlaid with digital orthophoto maps. Given that most regions with barchan dues have low relief, a 3D map obtained from a DTM may ineffectively show the stereoscopic shape of each dune. The method of building 3D models of barchan dunes using existing modeling software seldom considers the geographical environment. As a result, barchan dune models are often inconsistent with actual DTMs and incompletely express the morphological characteristics of dunes. Manual construction of barchan dune models is also costly and time consuming. Considering these problems, the morphological characteristics of barchan dunes and the mathematical relationships between the morphological parameters of the dunes, such as length, height, and width, are analyzed in this study. The methods of extracting the morphological feature points of barchan dunes, calculating their morphological parameters and building dune outlines and skeleton lines based on the medial axes, are also presented. The dune outlines, skeleton lines, and part of the medial axes of dunes are used to construct a constrained triangulated irregular network. C# and ArcEngine are employed to build 3D models of barchan dunes automatically. Experimental results of a study conducted in Tengger Desert show that the method can be used to approximate the morphological characteristics of barchan dunes and is less time consuming than manual methods.
Geometric and colour data fusion for outdoor 3D models.
Merchán, Pilar; Adán, Antonio; Salamanca, Santiago; Domínguez, Vicente; Chacón, Ricardo
2012-01-01
This paper deals with the generation of accurate, dense and coloured 3D models of outdoor scenarios from scanners. This is a challenging research field in which several problems still remain unsolved. In particular, the process of 3D model creation in outdoor scenes may be inefficient if the scene is digitalized under unsuitable technical (specific scanner on-board camera) and environmental (rain, dampness, changing illumination) conditions. We address our research towards the integration of images and range data to produce photorealistic models. Our proposal is based on decoupling the colour integration and geometry reconstruction stages, making them independent and controlled processes. This issue is approached from two different viewpoints. On the one hand, given a complete model (geometry plus texture), we propose a method to modify the original texture provided by the scanner on-board camera with the colour information extracted from external images taken at given moments and under specific environmental conditions. On the other hand, we propose an algorithm to directly assign external images onto the complete geometric model, thus avoiding tedious on-line calibration processes. We present the work conducted on two large Roman archaeological sites dating from the first century A.D., namely, the Theatre of Segobriga and the Fori Porticus of Emerita Augusta, both in Spain. The results obtained demonstrate that our approach could be useful in the digitalization and 3D modelling fields.
Zig-Zag Thermal-Chemical 3-D Instabilities in the Mantle Wedge: Numerical Study
NASA Astrophysics Data System (ADS)
Zhu, G.; Gerya, T. V.; Arcay, D.; Yuen, D. A.
2008-12-01
To understand the plume initiation and propagation it is important to understand whether small-scale convection is occurring under the back-arc in the Low Viscosity Wedge(LVW) and its implication on the island-arc volcanism. Honda et al. [Honda and Saito, 2003; Honda, et al., 2007]) already deployed small- scale convection in the Low Viscosity Wedge (LVW) above a subducting slab with kinematically imposed velocity boundary condition. They have suggested that a roll (finger)-like pattern of hot and cold anomalies emerges in the mantle wedge above the subducting slab. Here, we perform three-dimensional coupled petrological-thermomechanical numerical simulations of intraoceanic one-sided subduction with spontaneously bending retreating slab characterized by weak hydrated upper interface by using multigrid approach combined with characteristics-based marker-in-cell method with conservative finite difference schemes[Gerya and Yuen, 2003a], to investigate the 3D instabilities above the slab and lateral variation along the arc. Our results show that water released from subducting slab through dehydration reactions may lower the viscosity of the mantle. It allows the existence of wave-like small-scale convection in the LVW, which is shown as roll-like structure in 2D petrological-thermomechanical numerical experiments [Gorczyk et al., 2006] using in-situ rock properties computed on the basis of Gibbs free energy minimization. However, in our 3D cases, the rolls aligning with the arc mainly occur earlier , while zig-zag small-scale thermal-chemical instabilities may episodically form above the slab at later stages, which is different from the aligning finger-like pattern in purely thermal models (Honda et al,2003;2007). Also in contrast to thermal convection chemically buoyant hydrated plumes rising from the slab in our models are actually colder then the mantle wedge [Gerya and Yuen 2003b] which also strongly modify both the convection pattern and the seismic structure in
3-D model-based tracking for UAV indoor localization.
Teulière, Céline; Marchand, Eric; Eck, Laurent
2015-05-01
This paper proposes a novel model-based tracking approach for 3-D localization. One main difficulty of standard model-based approach lies in the presence of low-level ambiguities between different edges. In this paper, given a 3-D model of the edges of the environment, we derive a multiple hypotheses tracker which retrieves the potential poses of the camera from the observations in the image. We also show how these candidate poses can be integrated into a particle filtering framework to guide the particle set toward the peaks of the distribution. Motivated by the UAV indoor localization problem where GPS signal is not available, we validate the algorithm on real image sequences from UAV flights.
Parallel tempering and 3D spin glass models
NASA Astrophysics Data System (ADS)
Papakonstantinou, T.; Malakis, A.
2014-03-01
We review parallel tempering schemes and examine their main ingredients for accuracy and efficiency. We discuss two selection methods of temperatures and some alternatives for the exchange of replicas, including all-pair exchange methods. We measure specific heat errors and round-trip efficiency using the two-dimensional (2D) Ising model, and also test the efficiency for the ground state production in 3D spin glass models. We find that the optimization of the GS problem is highly influenced by the choice of the temperature range of the PT process. Finally, we present numerical evidence concerning the universality aspects of an anisotropic case of the 3D spin-glass model.
3D Multispectral Light Propagation Model For Subcutaneous Veins Imaging
Paquit, Vincent C; Price, Jeffery R; Meriaudeau, Fabrice; Tobin Jr, Kenneth William
2008-01-01
In this paper, we describe a new 3D light propagation model aimed at understanding the effects of various physiological properties on subcutaneous vein imaging. In particular, we build upon the well known MCML (Monte Carlo Multi Layer) code and present a tissue model that improves upon the current state-of-the-art by: incorporating physiological variation, such as melanin concentration, fat content, and layer thickness; including veins of varying depth and diameter; using curved surfaces from real arm shapes; and modeling the vessel wall interface. We describe our model, present results from the Monte Carlo modeling, and compare these results with those obtained with other Monte Carlo methods.
Generation and use of human 3D-CAD models
NASA Astrophysics Data System (ADS)
Grotepass, Juergen; Speyer, Hartmut; Kaiser, Ralf
2002-05-01
Individualized Products are one of the ten mega trends of the 21st Century with human modeling as the key issue for tomorrow's design and product development. The use of human modeling software for computer based ergonomic simulations within the production process increases quality while reducing costs by 30- 50 percent and shortening production time. This presentation focuses on the use of human 3D-CAD models for both, the ergonomic design of working environments and made to measure garment production. Today, the entire production chain can be designed, individualized models generated and analyzed in 3D computer environments. Anthropometric design for ergonomics is matched to human needs, thus preserving health. Ergonomic simulation includes topics as human vision, reachability, kinematics, force and comfort analysis and international design capabilities. In German more than 17 billions of Mark are moved to other industries, because clothes do not fit. Individual clothing tailored to the customer's preference means surplus value, pleasure and perfect fit. The body scanning technology is the key to generation and use of human 3D-CAD models for both, the ergonomic design of working environments and made to measure garment production.
Method for modeling post-mortem biometric 3D fingerprints
NASA Astrophysics Data System (ADS)
Rajeev, Srijith; Shreyas, Kamath K. M.; Agaian, Sos S.
2016-05-01
Despite the advancements of fingerprint recognition in 2-D and 3-D domain, authenticating deformed/post-mortem fingerprints continue to be an important challenge. Prior cleansing and reconditioning of the deceased finger is required before acquisition of the fingerprint. The victim's finger needs to be precisely and carefully operated by a medium to record the fingerprint impression. This process may damage the structure of the finger, which subsequently leads to higher false rejection rates. This paper proposes a non-invasive method to perform 3-D deformed/post-mortem finger modeling, which produces a 2-D rolled equivalent fingerprint for automated verification. The presented novel modeling method involves masking, filtering, and unrolling. Computer simulations were conducted on finger models with different depth variations obtained from Flashscan3D LLC. Results illustrate that the modeling scheme provides a viable 2-D fingerprint of deformed models for automated verification. The quality and adaptability of the obtained unrolled 2-D fingerprints were analyzed using NIST fingerprint software. Eventually, the presented method could be extended to other biometric traits such as palm, foot, tongue etc. for security and administrative applications.
3D cartographic modeling of the Alpine arc
NASA Astrophysics Data System (ADS)
Vouillamoz, Naomi; Sue, Christian; Champagnac, Jean-Daniel; Calcagno, Philippe
2012-12-01
We built a 3D cartography of the Alpine arc, a highly non-cylindrical mountain belt, using the 3D GeoModeller of the BRGM (French geological survey). The model allows to handle the large-scale 3D structure of seventeen major crustal units of the belt (from the lower crust to the sedimentary cover nappes), and two main discontinuities (the Insubric Line and the Crustal Penninic Front). It provides a unique document to better understand their structural relationships and to produce new sections. The study area comprises the western Alpine arc, from the Jura to the Northwest, up to the Bergell granite intrusion and the Lepontine Dome to the East, and is limited to the South by the Ligurian basin. The model is limited vertically 10 km above sea level at the top, and the moho interface at the bottom. We discarded the structural relationships between the Alps sensus stricto and the surrounding geodynamic systems such as the Rhine graben or the connection with the Apennines. The 3D-model is based on the global integration of various data such as the DEM of the Alps, the moho isobaths, the simplified geological and tectonic maps of the belt, the crustal cross-sections ECORS-CROP and NFP-20, and complementary cross-sections specifically built to precise local complexities. The database has first been integrated in a GIS-project to prepare their implementation in the GeoModeller, by homogenizing the different spatial referencing systems. The global model is finally interpolated from all these data, using the potential field method. The final document is a new tri-dimensional cartography that would be used as input for further alpine studies.
Geometric and Textural Blending for 3D Model Stylization.
Huang, YiJheng; Lin, Wen-Chieh; Yeh, I-Cheng; Lee, Tong-Yee
2017-01-25
Stylizing a 3D model with characteristic shapes or appearances is common in product design, particularly in the design of 3D model merchandise, such as souvenirs, toys, furniture, and stylized items. A model stylization approach is proposed in this study. The approach combines base and style models while preserving user-specified shape features of the base model and the attractive features of the style model with limited assistance from a user. The two models are first combined at the topological level. A tree-growing technique is utilized to search for all possible combinations of the two models. Second, the models are combined at textural and geometric levels by employing a morphing technique. Results show that the proposed approach generates various appealing models and allows users to control the diversity of the output models and adjust the blending degree between the base and style models. The results of this work are also experimentally compared with those of a recent work through a user study. The comparison indicates that our results are more appealing, feature-preserving, and reasonable than those of the compared previous study. The proposed system allows product designers to easily explore design possibilities and assists novice users in creating their own stylized models.
CityGML - Interoperable semantic 3D city models
NASA Astrophysics Data System (ADS)
Gröger, Gerhard; Plümer, Lutz
2012-07-01
CityGML is the international standard of the Open Geospatial Consortium (OGC) for the representation and exchange of 3D city models. It defines the three-dimensional geometry, topology, semantics and appearance of the most relevant topographic objects in urban or regional contexts. These definitions are provided in different, well-defined Levels-of-Detail (multiresolution model). The focus of CityGML is on the semantical aspects of 3D city models, its structures, taxonomies and aggregations, allowing users to employ virtual 3D city models for advanced analysis and visualization tasks in a variety of application domains such as urban planning, indoor/outdoor pedestrian navigation, environmental simulations, cultural heritage, or facility management. This is in contrast to purely geometrical/graphical models such as KML, VRML, or X3D, which do not provide sufficient semantics. CityGML is based on the Geography Markup Language (GML), which provides a standardized geometry model. Due to this model and its well-defined semantics and structures, CityGML facilitates interoperable data exchange in the context of geo web services and spatial data infrastructures. Since its standardization in 2008, CityGML has become used on a worldwide scale: tools from notable companies in the geospatial field provide CityGML interfaces. Many applications and projects use this standard. CityGML is also having a strong impact on science: numerous approaches use CityGML, particularly its semantics, for disaster management, emergency responses, or energy-related applications as well as for visualizations, or they contribute to CityGML, improving its consistency and validity, or use CityGML, particularly its different Levels-of-Detail, as a source or target for generalizations. This paper gives an overview of CityGML, its underlying concepts, its Levels-of-Detail, how to extend it, its applications, its likely future development, and the role it plays in scientific research. Furthermore, its
Lattice percolation approach to 3D modeling of tissue aging
NASA Astrophysics Data System (ADS)
Gorshkov, Vyacheslav; Privman, Vladimir; Libert, Sergiy
2016-11-01
We describe a 3D percolation-type approach to modeling of the processes of aging and certain other properties of tissues analyzed as systems consisting of interacting cells. Lattice sites are designated as regular (healthy) cells, senescent cells, or vacancies left by dead (apoptotic) cells. The system is then studied dynamically with the ongoing processes including regular cell dividing to fill vacant sites, healthy cells becoming senescent or dying, and senescent cells dying. Statistical-mechanics description can provide patterns of time dependence and snapshots of morphological system properties. The developed theoretical modeling approach is found not only to corroborate recent experimental findings that inhibition of senescence can lead to extended lifespan, but also to confirm that, unlike 2D, in 3D senescent cells can contribute to tissue's connectivity/mechanical stability. The latter effect occurs by senescent cells forming the second infinite cluster in the regime when the regular (healthy) cell's infinite cluster still exists.
The 3D model control of image processing
NASA Technical Reports Server (NTRS)
Nguyen, An H.; Stark, Lawrence
1989-01-01
Telerobotics studies remote control of distant robots by a human operator using supervisory or direct control. Even if the robot manipulators has vision or other senses, problems arise involving control, communications, and delay. The communication delays that may be expected with telerobots working in space stations while being controlled from an Earth lab have led to a number of experiments attempting to circumvent the problem. This delay in communication is a main motivating factor in moving from well understood instantaneous hands-on manual control to less well understood supervisory control; the ultimate step would be the realization of a fully autonomous robot. The 3-D model control plays a crucial role in resolving many conflicting image processing problems that are inherent in resolving in the bottom-up approach of most current machine vision processes. The 3-D model control approach is also capable of providing the necessary visual feedback information for both the control algorithms and for the human operator.
Modeling 3D faces from samplings via compressive sensing
NASA Astrophysics Data System (ADS)
Sun, Qi; Tang, Yanlong; Hu, Ping
2013-07-01
3D data is easier to acquire for family entertainment purpose today because of the mass-production, cheapness and portability of domestic RGBD sensors, e.g., Microsoft Kinect. However, the accuracy of facial modeling is affected by the roughness and instability of the raw input data from such sensors. To overcome this problem, we introduce compressive sensing (CS) method to build a novel 3D super-resolution scheme to reconstruct high-resolution facial models from rough samples captured by Kinect. Unlike the simple frame fusion super-resolution method, this approach aims to acquire compressed samples for storage before a high-resolution image is produced. In this scheme, depth frames are firstly captured and then each of them is measured into compressed samples using sparse coding. Next, the samples are fused to produce an optimal one and finally a high-resolution image is recovered from the fused sample. This framework is able to recover 3D facial model of a given user from compressed simples and this can reducing storage space as well as measurement cost in future devices e.g., single-pixel depth cameras. Hence, this work can potentially be applied into future applications, such as access control system using face recognition, and smart phones with depth cameras, which need high resolution and little measure time.
3D modelling of the Black Sea ecosystem
NASA Astrophysics Data System (ADS)
Capet, A.; Gregoire, M.; Beckers, J.-M.; Joassin, P.; Naithani, J.; Soetart, K.
2009-04-01
A coupled physical-biogeochemical model has been developed to simulate the ecosystem of the Black Sea at the end of the 80's when eutrophication and invasion by gelatinous organisms seriously affected the stability and dynamics of the system. The biogeochemical model describes the cycle of carbon, nitrogen, silicate, oxygen and phosphorus through the foodweb from bacteria to gelatinous carnivores and explicitly represents processes in the anoxic layer down to the bottom. For calibration and analyses purposes, the coupled model has first been run in 1D at several places in the Black Sea. The biogeochemical model involves some hundred parameters which have been first calibrated by hand using published values. Then, an identifiability analysis has been performed in order to determine a subset of 15 identifiable parameters. An automatic calibration subroutine has been used to fine tune these parameters. In 1D, the model solution exhibits a complex dynamics with several years of transient adjustment. This complexity is imparted by the explicit modelling of top predators. The model has been calibrated and validated using a large set of data available in the Black Sea TU Ocean Base. The calibrated biogeochemical model is implemented in a 3D hydrodynamical model of the Black Sea. Results of these 3D simulations will be presented and compared with maps of in-situ data reconstructed from available data base using the software DIVA (Data Interpolation and Variational analysis).
West Flank Coso, CA FORGE 3D geologic model
Doug Blankenship
2016-03-01
This is an x,y,z file of the West Flank FORGE 3D geologic model. Model created in Earthvision by Dynamic Graphic Inc. The model was constructed with a grid spacing of 100 m. Geologic surfaces were extrapolated from the input data using a minimum tension gridding algorithm. The data file is tabular data in a text file, with lithology data associated with X,Y,Z grid points. All the relevant information is in the file header (the spatial reference, the projection etc.) In addition all the fields in the data file are identified in the header.
3D-printer visualization of neuron models.
McDougal, Robert A; Shepherd, Gordon M
2015-01-01
Neurons come in a wide variety of shapes and sizes. In a quest to understand this neuronal diversity, researchers have three-dimensionally traced tens of thousands of neurons; many of these tracings are freely available through online repositories like NeuroMorpho.Org and ModelDB. Tracings can be visualized on the computer screen, used for statistical analysis of the properties of different cell types, used to simulate neuronal behavior, and more. We introduce the use of 3D printing as a technique for visualizing traced morphologies. Our method for generating printable versions of a cell or group of cells is to expand dendrite and axon diameters and then to transform the tracing into a 3D object with a neuronal surface generating algorithm like Constructive Tessellated Neuronal Geometry (CTNG). We show that 3D printed cells can be readily examined, manipulated, and compared with other neurons to gain insight into both the biology and the reconstruction process. We share our printable models in a new database, 3DModelDB, and encourage others to do the same with cells that they generate using our code or other methods. To provide additional context, 3DModelDB provides a simulatable version of each cell, links to papers that use or describe it, and links to associated entries in other databases.
3D-printer visualization of neuron models
McDougal, Robert A.; Shepherd, Gordon M.
2015-01-01
Neurons come in a wide variety of shapes and sizes. In a quest to understand this neuronal diversity, researchers have three-dimensionally traced tens of thousands of neurons; many of these tracings are freely available through online repositories like NeuroMorpho.Org and ModelDB. Tracings can be visualized on the computer screen, used for statistical analysis of the properties of different cell types, used to simulate neuronal behavior, and more. We introduce the use of 3D printing as a technique for visualizing traced morphologies. Our method for generating printable versions of a cell or group of cells is to expand dendrite and axon diameters and then to transform the tracing into a 3D object with a neuronal surface generating algorithm like Constructive Tessellated Neuronal Geometry (CTNG). We show that 3D printed cells can be readily examined, manipulated, and compared with other neurons to gain insight into both the biology and the reconstruction process. We share our printable models in a new database, 3DModelDB, and encourage others to do the same with cells that they generate using our code or other methods. To provide additional context, 3DModelDB provides a simulatable version of each cell, links to papers that use or describe it, and links to associated entries in other databases. PMID:26175684
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.
Right approach to 3D modeling using CAD tools
NASA Astrophysics Data System (ADS)
Baddam, Mounica Reddy
The thesis provides a step-by-step methodology to enable an instructor dealing with CAD tools to optimally guide his/her students through an understandable 3D modeling approach which will not only enhance their knowledge about the tool's usage but also enable them to achieve their desired result in comparatively lesser time. In the known practical field, there is particularly very little information available to apply CAD skills to formal beginners' training sessions. Additionally, advent of new software in 3D domain cumulates updating into a more difficult task. Keeping up to the industry's advanced requirements emphasizes the importance of more skilled hands in the field of CAD development, rather than just prioritizing manufacturing in terms of complex software features. The thesis analyses different 3D modeling approaches specified to the varieties of CAD tools currently available in the market. Utilizing performance-time databases, learning curves have been generated to measure their performance time, feature count etc. Based on the results, improvement parameters have also been provided for (Asperl, 2005).
Effective 3-D surface modeling for geographic information systems
NASA Astrophysics Data System (ADS)
Yüksek, K.; Alparslan, M.; Mendi, E.
2016-01-01
In this work, we propose a dynamic, flexible and interactive urban digital terrain platform with spatial data and query processing capabilities of geographic information systems, multimedia database functionality and graphical modeling infrastructure. A new data element, called Geo-Node, which stores image, spatial data and 3-D CAD objects is developed using an efficient data structure. The system effectively handles data transfer of Geo-Nodes between main memory and secondary storage with an optimized directional replacement policy (DRP) based buffer management scheme. Polyhedron structures are used in digital surface modeling and smoothing process is performed by interpolation. The experimental results show that our framework achieves high performance and works effectively with urban scenes independent from the amount of spatial data and image size. The proposed platform may contribute to the development of various applications such as Web GIS systems based on 3-D graphics standards (e.g., X3-D and VRML) and services which integrate multi-dimensional spatial information and satellite/aerial imagery.
The mantle wedge's transient 3-D flow regime and thermal structure
NASA Astrophysics Data System (ADS)
Davies, D. R.; Le Voci, G.; Goes, S.; Kramer, S. C.; Wilson, C. R.
2016-01-01
Arc volcanism, volatile cycling, mineralization, and continental crust formation are likely regulated by the mantle wedge's flow regime and thermal structure. Wedge flow is often assumed to follow a regular corner-flow pattern. However, studies that incorporate a hydrated rheology and thermal buoyancy predict internal small-scale-convection (SSC). Here, we systematically explore mantle-wedge dynamics in 3-D simulations. We find that longitudinal "Richter-rolls" of SSC (with trench-perpendicular axes) commonly occur if wedge hydration reduces viscosities to Pa s, although transient transverse rolls (with trench-parallel axes) can dominate at viscosities of Pa s. Rolls below the arc and back arc differ. Subarc rolls have similar trench-parallel and trench-perpendicular dimensions of 100-150 km and evolve on a 1-5 Myr time-scale. Subback-arc instabilities, on the other hand, coalesce into elongated sheets, usually with a preferential trench-perpendicular alignment, display a wavelength of 150-400 km and vary on a 5-10 Myr time scale. The modulating influence of subback-arc ridges on the subarc system increases with stronger wedge hydration, higher subduction velocity, and thicker upper plates. We find that trench-parallel averages of wedge velocities and temperature are consistent with those predicted in 2-D models. However, lithospheric thinning through SSC is somewhat enhanced in 3-D, thus expanding hydrous melting regions and shifting dehydration boundaries. Subarc Richter-rolls generate time-dependent trench-parallel temperature variations of up to K, which exceed the transient 50-100 K variations predicted in 2-D and may contribute to arc-volcano spacing and the variable seismic velocity structures imaged beneath some arcs.
Underwater 3d Modeling: Image Enhancement and Point Cloud Filtering
NASA Astrophysics Data System (ADS)
Sarakinou, I.; Papadimitriou, K.; Georgoula, O.; Patias, P.
2016-06-01
This paper examines the results of image enhancement and point cloud filtering on the visual and geometric quality of 3D models for the representation of underwater features. Specifically it evaluates the combination of effects from the manual editing of images' radiometry (captured at shallow depths) and the selection of parameters for point cloud definition and mesh building (processed in 3D modeling software). Such datasets, are usually collected by divers, handled by scientists and used for geovisualization purposes. In the presented study, have been created 3D models from three sets of images (seafloor, part of a wreck and a small boat's wreck) captured at three different depths (3.5m, 10m and 14m respectively). Four models have been created from the first dataset (seafloor) in order to evaluate the results from the application of image enhancement techniques and point cloud filtering. The main process for this preliminary study included a) the definition of parameters for the point cloud filtering and the creation of a reference model, b) the radiometric editing of images, followed by the creation of three improved models and c) the assessment of results by comparing the visual and the geometric quality of improved models versus the reference one. Finally, the selected technique is tested on two other data sets in order to examine its appropriateness for different depths (at 10m and 14m) and different objects (part of a wreck and a small boat's wreck) in the context of an ongoing research in the Laboratory of Photogrammetry and Remote Sensing.
Modeling and Processing of Continuous 3D Elastic Wavefield Data
NASA Astrophysics Data System (ADS)
Milkereit, B.; Bohlen, T.
2001-12-01
Continuous seismic wavefields are excited by earthquake clustering, induced seismicity in reservoirs, and mining. In hydrocarbon reservoirs, for example, pore pressure changes and fluid flow (mass transfer) will cause incremental deviatoric stresses sufficient to trigger and sustain seismic activity. Here we address three aspects of seismic wavefields in three-dimensional heterogeneous media triggered by distributed sources in space and time: forward modeling, multichannel data processing, and source location imaging. A power law distribution of seismic sources (such as the Gutenberg-Richter law) is used for the modeling of viscoelastic/elastic wave propagation through a realistic earth model. 3D modeling provides new insight in the interaction of multi-source wavefields and the role of scale-dependend elastic model parameters on transmitted and reflected/back-scattered wavefields. There exists a strong correlation between the spatial properties of the compressional, shear wave and density perturbations and the lateral correlation length of the resulting reflected or transmitted seismic wavefields. Modeling is based on the implementation of 3D elastic/viscoelastic FD codes on massive parallel and/or distributed computing resources using MPI (message passing interface). For parallelization, large grid 3D earth models are decomposed into subvolume processing elements whereby each processing element is updating the wavefield within its portion of the grid. Processing of continuous seismic wavefields excited by multiple distributed sources is based on a combination of crosscorrelated or slowness-transformed array data and Kirchhoff or reverse time migration for source location or source volume imaging. The appearance of slowness in both migration and array data processing suggests the possibility of combining them into a single process. In order to place further constraints on the migration, the directivity properties of 3-component receiver arrays can be included in
3D Geologic Model of the San Diego Area
NASA Astrophysics Data System (ADS)
Danskin, W. R.; Cromwell, G.; Glockhoff, C.; Martin, D.
2015-12-01
Prior geologic studies of the San Diego area, including northern Baja California, Mexico, focused on site investigations, characterization of rock formations, or earthquake hazards. No comprehensive, quantitative model characterizing the three-dimensional (3D) geology of the entire area has been developed. The lack of such a model limits understanding of large-scale processes, such as development of ancient landforms, and groundwater movement and availability. To evaluate these regional processes, the United States Geological Survey (USGS) conducted a study to better understand the geologic structure of the San Diego area. A cornerstone of this study is the installation and analysis of 77 wells at 12 multiple-depth monitoring-well sites. Geologic information from these wells was combined with lithologic data from 81 oil exploration wells and municipal and private water wells, gravity and seismic interpretations, and paleontological interpretations. These data were analyzed in conjunction with geologic maps and digital elevation models to develop a 3D geologic model of the San Diego area, in particular of the San Diego embayment. Existing interpretations of regional surficial geology, faulting, and tectonic history provided the framework for this model, which was refined by independent evaluation of subsurface geology. Geologic formations were simplified into five sedimentary units (Quaternary, Plio-Pleistocene, Oligocene, Eocene and Cretaceous ages), and one basal crystalline unit (primarily Cretaceous and Jurassic). Complex fault systems are represented in the model by ten fault strands that maintain overall displacement. The 3D geologic model corroborates existing geologic concepts of the San Diego area, refines the extent of subsurface geology, and allows users to holistically evaluate subsurface structures and regional hydrogeology.
3D flare particle model for ShipIR/NTCS
NASA Astrophysics Data System (ADS)
Ramaswamy, Srinivasan; Vaitekunas, David A.
2016-05-01
A key component in any soft-kill response to an incoming guided missile is the flare /chaff decoy used to distract or seduce the seeker homing system away from the naval platform. This paper describes a new 3D flare particle model in the naval threat countermeasure simulator (NTCS) of the NATO-standard ship signature model (ShipIR), which provides independent control over the size and radial distribution of its signature. The 3D particles of each flare sub-munition are modelled stochastically and rendered using OpenGL z-buffering, 2D projection, and alpha-blending to produce a unique and time varying signature. A sensitivity analysis on each input parameter provides the data and methods needed to synthesize a model from an IR measurement of a decoy. The new model also eliminated artifacts and deficiencies in our previous model which prevented reliable tracks from the adaptive track gate algorithm already presented by Ramaswamy and Vaitekunas (2015). A sequence of scenarios are used to test and demonstrate the new flare model during a missile engagement.
Modeling Extracellular Matrix Reorganization in 3D Environments
Harjanto, Dewi; Zaman, Muhammad H.
2013-01-01
Extracellular matrix (ECM) remodeling is a key physiological process that occurs in a number of contexts, including cell migration, and is especially important for cellular form and function in three-dimensional (3D) matrices. However, there have been few attempts to computationally model how cells modify their environment in a manner that accounts for both cellular properties and the architecture of the surrounding ECM. To this end, we have developed and validated a novel model to simulate matrix remodeling that explicitly defines cells in a 3D collagenous matrix. In our simulation, cells can degrade, deposit, or pull on local fibers, depending on the fiber density around each cell. The cells can also move within the 3D matrix. Different cell phenotypes can be modeled by varying key cellular parameters. Using the model we have studied how two model cancer cell lines, of differing invasiveness, modify matrices with varying fiber density in their vicinity by tracking the metric of fraction of matrix occupied by fibers. Our results quantitatively demonstrate that in low density environments, cells deposit more collagen to uniformly increase fibril fraction. On the other hand, in higher density environments, the less invasive model cell line reduced the fibril fraction as compared to the highly invasive phenotype. These results show good qualitative and quantitative agreement with existing experimental literature. Our simulation is therefore able to function as a novel platform to provide new insights into the clinically relevant and physiologically critical process of matrix remodeling by helping identify critical parameters that dictate cellular behavior in complex native-like environments. PMID:23341900
NASA Astrophysics Data System (ADS)
Norajitra, Tobias; Meinzer, Hans-Peter; Maier-Hein, Klaus H.
2015-03-01
During image segmentation, 3D Statistical Shape Models (SSM) usually conduct a limited search for target landmarks within one-dimensional search profiles perpendicular to the model surface. In addition, landmark appearance is modeled only locally based on linear profiles and weak learners, altogether leading to segmentation errors from landmark ambiguities and limited search coverage. We present a new method for 3D SSM segmentation based on 3D Random Forest Regression Voting. For each surface landmark, a Random Regression Forest is trained that learns a 3D spatial displacement function between the according reference landmark and a set of surrounding sample points, based on an infinite set of non-local randomized 3D Haar-like features. Landmark search is then conducted omni-directionally within 3D search spaces, where voxelwise forest predictions on landmark position contribute to a common voting map which reflects the overall position estimate. Segmentation experiments were conducted on a set of 45 CT volumes of the human liver, of which 40 images were randomly chosen for training and 5 for testing. Without parameter optimization, using a simple candidate selection and a single resolution approach, excellent results were achieved, while faster convergence and better concavity segmentation were observed, altogether underlining the potential of our approach in terms of increased robustness from distinct landmark detection and from better search coverage.
Digital 3D Borobudur - Integration of 3D surveying and modeling techniques
NASA Astrophysics Data System (ADS)
Suwardhi, D.; Menna, F.; Remondino, F.; Hanke, K.; Akmalia, R.
2015-08-01
The Borobudur temple (Indonesia) is one of the greatest Buddhist monuments in the world, now listed as an UNESCO World Heritage Site. The present state of the temple is the result of restorations after being exposed to natural disasters several times. Today there is still a growing rate of deterioration of the building stones whose causes need further researches. Monitoring programs, supported at institutional level, have been effectively executed to observe the problem. The paper presents the latest efforts to digitally document the Borobudur Temple and its surrounding area in 3D with photogrammetric techniques. UAV and terrestrial images were acquired to completely digitize the temple, produce DEM, orthoimages and maps at 1:100 and 1:1000 scale. The results of the project are now employed by the local government organizations to manage the heritage area and plan new policies for the conservation and preservation of the UNESCO site. In order to help data management and policy makers, a web-based information system of the heritage area was also built to visualize and easily access all the data and achieved 3D results.
3-D modelling of seamount topography from satellite altimetry
Baudry, N. ); Calmant, S. )
1991-06-01
The authors develop a complete set of algorithms to perform 3D modelling of seamount bathymetry from satellite altimetry. The first stage of the data processing consists in gridding the geoid: to account for the long wavelength errors geoid heights are first bias-adjusted at cross-overs. Then a collocation on a regular grid is performed, accounting for the altimeter errors. In a second stage, geoid heights are converted into bathymetry. No simplifying assumption on the shape and location of the bathymetry highs is necessary. Bathymetric uncertainties due to the data sampling and the parameters of the mechanical and crustal models are evaluated.
3D Numerical Simulations of the Breakout Model
NASA Astrophysics Data System (ADS)
Choe, G. S.; Cheng, C. Z.; Lee, J.; Lynch, B. J.; Antiochos, S. K.; DeVore, C. R.; Zurbuchen, T. H.
2005-05-01
We present the continuing progress of the numerical simulations of the breakout model for coronal mass ejection initiation. To validate the 3D spherical ARMS code we have run the 2.5D breakout problem and compare the eruption to the published 2D results. The ARMS 2.5D CME also forms a large magnetic island ahead of the erupting plasmoid due to the code's excellent maintenance of equatorial symmetry. Progress on the fully 3D breakout problem is also discussed. To build up enough magnetic free energy for an eruption the active region field must be strong with a steep gradient near the polarity inversion line and the shear must be highly concentrated there. This requires adaptive griding techniques. In the current simulation, the active region to background field ratio is 20-to-1 and the neutral line is long compared to the active region width. We present the evolution of this topology under Br-conserving shearing flow and discuss implications for a 3D eruption. This work is supported by NASA and ONR. BJL is supported by NASA GSRP grant NGT5-50453.
Discrete Method of Images for 3D Radio Propagation Modeling
NASA Astrophysics Data System (ADS)
Novak, Roman
2016-09-01
Discretization by rasterization is introduced into the method of images (MI) in the context of 3D deterministic radio propagation modeling as a way to exploit spatial coherence of electromagnetic propagation for fine-grained parallelism. Traditional algebraic treatment of bounding regions and surfaces is replaced by computer graphics rendering of 3D reflections and double refractions while building the image tree. The visibility of reception points and surfaces is also resolved by shader programs. The proposed rasterization is shown to be of comparable run time to that of the fundamentally parallel shooting and bouncing rays. The rasterization does not affect the signal evaluation backtracking step, thus preserving its advantage over the brute force ray-tracing methods in terms of accuracy. Moreover, the rendering resolution may be scaled back for a given level of scenario detail with only marginal impact on the image tree size. This allows selection of scene optimized execution parameters for faster execution, giving the method a competitive edge. The proposed variant of MI can be run on any GPU that supports real-time 3D graphics.
Modeling the GFR with RELAP5-3D
Cliff B. Davis; Theron D. Marshall; K. D. Weaver
2005-09-01
Significant improvements have been made to the RELAP5-3D computer code for analysis of the Gas Fast Reactor (GFR). These improvements consisted of adding carbon dioxide as a working fluid, improving the turbine component, developing a compressor model, and adding the Gnielinski heat transfer correlation. The code improvements were validated, generally through comparisons with independent design calculations. A model of the power conversion unit of the GFR was developed. The model of the power conversion unit was coupled to a reactor model to develop a complete model of the GFR system. The RELAP5 model of the GFR was used to simulate two transients, one initiated by a reactor trip and the other initiated by a loss of load.
Testing Mercury Porosimetry with 3D Printed Porosity Models
NASA Astrophysics Data System (ADS)
Hasiuk, F.; Ewing, R. P.; Hu, Q.
2014-12-01
Mercury intrusion porosimetry is one of the most widely used techniques to study the porous nature of a geological and man-made materials. In the geosciences, it is commonly used to describe petroleum reservoir and seal rocks as well as to grade aggregates for the design of asphalt and portland cement concretes. It's wide utility stems from its ability to characterize a wide range of pore throat sizes (from nanometers to around a millimeter). The fundamental physical model underlying mercury intrusion porosimetry, the Washburn Equation, is based on the assumption that rock porosity can be described as a bundle of cylindrical tubes. 3D printing technology, also known as rapid prototyping, allows the construction of intricate and accurate models, exactly what is required to build models of rock porosity. We evaluate the applicability of the Washburn Equation by comparing properties (like porosity, pore and pore throat size distribution, and surface area) computed on digital porosity models (built from CT data, CAD designs, or periodic geometries) to properties measured via mercury intrusion porosimetry on 3D printed versions of the same digital porosity models.
Modeling radiative transfer in heterogeneous 3D vegetation canopies
NASA Astrophysics Data System (ADS)
Gastellu-Etchegorry, J. P.; Demarez, V.; Pinel, Veronique; Zagolski, Francis
1995-01-01
The DART (discrete anisotropic radiative transfer) model simulates radiative transfer in heterogeneous 3-D scenes; here, a forest plantation. Similarly to Kimes model, the scene is divided into a rectangular cell matrix, i.e., a building block for simulating larger scenes. Cells are parallelipipedic. The scene encompasses different landscape features (i.e., trees with leaves and trunks, grass, water, and soil) with specific optical (reflectance, transmittance) and structural (LAI, LAD) characteristics. Radiation directions are subdivided into contiguous sectors with possibly uneven spacing. Topography, hot spot, and multiple interactions (scattering, attenuation) within cells are modeled. Two major steps are distinguished: (1) Illumination of cells by direct sun radiation. Actual locations of within cell scattering are determined for optimizing scattering computation. (2) Interception and scattering of previously scattered radiation. Diffuse atmospheric radiation is input at this level. Multiple scattering is represented with a spherical harmonic decomposition, for reducing data volume. The model iterates on step 2 for all cells, and stops with the energetic equilibrium. This model predicts the bi-directional reflectance factors of 3D canopies, with each scene component contribution; it was successfully tested with homogeneous covers. It gives also the radiation regime with canopies, and consequently some information about volume distribution of photosynthesis rates and primary production.
Complex tephra dispersion from 3D plume modeling using ATHAM
NASA Astrophysics Data System (ADS)
Nicholson, B. C.; Kobs-Nawotniak, S. E.
2014-12-01
Most volcanic hazard assessments are based on a classic inversion tool for tephra deposits that relies on a simple integral model to explain the eruption plume. While this tool is adequate for first-order predictions of tephra deposition under no-wind conditions, the simplifying assumptions make it unreliable for ambient winds >10 m/s. Advances in computational power now make it possible to improve the inversion tool using 3D fluid dynamics. We do this with the physics-based Active Tracer High-resolution Atmospheric Model (ATHAM) to model tephra dispersion and deposition from volcanic eruption columns. The model, when run in 3D, is able to capture the complex morphology of bent plumes. Tephra distributions produced by these morphologies differ significantly from distributions created by idealized advection solutions, reflecting the effects of counter-rotating vortex pairs, puffing modes, or plume bifurcation. The modeled tephra deposition better captures the complex effects of wind-plume interaction, allowing us to update classic inversion tools with more realistic weak plume conditions consistent with typical historical explosive eruptions.
3-D physical modeling of a complex salt canopy
Wiley, R.W.; Sekharan, K.K.
1996-12-31
Recent drilling has confirmed both significant reservoir potential and the presence of commercial hydrocarbons below salt structures in the Gulf of Mexico. Obtaining definitive seismic images with standard processing schemes beneath these salt structures is very difficult if not impossible. Because of the complicated seismic behavior of these structures, full volume 3-D prestack depth migration is required. Unfortunately, carrying out the multitude of calculations needed to create a proper image requires the largest and fastest supercomputers and rather complex numerical algorithms. Furthermore, developing and testing the imaging algorithms is quite involved and requires appropriate test data sets. To better understand the problems and issues of subsalt imaging, Marathon Oil Company and Louisiana Land and Exploration Company contracted with the University of Houston`s Allied Geophysical Laboratories (AGL) to construct a salt canopy physical model. The model is patterned after the SEG/EAEG Salt Model and is made from synthetic materials. It is a full three-dimensional model with an irregularly shaped, lateral salt structure embedded in five distinct sedimentary layers. The model was used to acquire a multi-offset 3-D marine-style survey. These data are being used to address problems of subsalt imaging. In addition to standard processing techniques, the authors investigate algorithms for multiple removal and prestack depth migration.
Exploiting Textured 3D Models for Developing Serious Games
NASA Astrophysics Data System (ADS)
Kontogianni, G.; Georgopoulos, A.
2015-08-01
Digital technologies have affected significantly many fields of computer graphics such as Games and especially the field of the Serious Games. These games are usually used for educational proposes in many fields such as Health Care, Military applications, Education, Government etc. Especially Digital Cultural Heritage is a scientific area that Serious Games are applied and lately many applications appear in the related literature. Realistic 3D textured models which have been produced using different photogrammetric methods could be a useful tool for the creation of Serious Game applications in order to make the final result more realistic and close to the reality. The basic goal of this paper is how 3D textured models which are produced by photogrammetric methods can be useful for developing a more realistic environment of a Serious Game. The application of this project aims at the creation of an educational game for the Ancient Agora of Athens. The 3D models used vary not only as far as their production methods (i.e. Time of Flight laser scanner, Structure from Motion, Virtual historical reconstruction etc.) is concerned, but also as far as their era as some of them illustrated according to their existing situation and some others according to how these monuments looked like in the past. The Unity 3D® game developing environment was used for creating this application, in which all these models were inserted in the same file format. For the application two diachronic virtual tours of the Athenian Agora were produced. The first one illustrates the Agora as it is today and the second one at the 2nd century A.D. Finally the future perspective for the evolution of this game is presented which includes the addition of some questions that the user will be able to answer. Finally an evaluation is scheduled to be performed at the end of the project.
3D model tools for architecture and archaeology reconstruction
NASA Astrophysics Data System (ADS)
Vlad, Ioan; Herban, Ioan Sorin; Stoian, Mircea; Vilceanu, Clara-Beatrice
2016-06-01
The main objective of architectural and patrimonial survey is to provide a precise documentation of the status quo of the surveyed objects (monuments, buildings, archaeological object and sites) for preservation and protection, for scientific studies and restoration purposes, for the presentation to the general public. Cultural heritage documentation includes an interdisciplinary approach having as purpose an overall understanding of the object itself and an integration of the information which characterize it. The accuracy and the precision of the model are directly influenced by the quality of the measurements realized on field and by the quality of the software. The software is in the process of continuous development, which brings many improvements. On the other side, compared to aerial photogrammetry, close range photogrammetry and particularly architectural photogrammetry is not limited to vertical photographs with special cameras. The methodology of terrestrial photogrammetry has changed significantly and various photographic acquisitions are widely in use. In this context, the present paper brings forward a comparative study of TLS (Terrestrial Laser Scanner) and digital photogrammetry for 3D modeling. The authors take into account the accuracy of the 3D models obtained, the overall costs involved for each technology and method and the 4th dimension - time. The paper proves its applicability as photogrammetric technologies are nowadays used at a large scale for obtaining the 3D model of cultural heritage objects, efficacious in their assessment and monitoring, thus contributing to historic conservation. Its importance also lies in highlighting the advantages and disadvantages of each method used - very important issue for both the industrial and scientific segment when facing decisions such as in which technology to invest more research and funds.
The Engelbourg's ruins: from 3D TLS point cloud acquisition to 3D virtual and historic models
NASA Astrophysics Data System (ADS)
Koehl, Mathieu; Berger, Solveig; Nobile, Sylvain
2014-05-01
The Castle of Engelbourg was built at the beginning of the 13th century, at the top of the Schlossberg. It is situated on the territory of the municipality of Thann (France), at the crossroads of Alsace and Lorraine, and dominates the outlet of the valley of Thur. Its strategic position was one of the causes of its systematic destructions during the 17th century, and Louis XIV finished his fate by ordering his demolition in 1673. Today only few vestiges remain, of which a section of the main tower from about 7m of diameter and 4m of wide laying on its slice, unique characteristic in the regional castral landscape. It is visible since the valley, was named "the Eye of the witch", and became a key attraction of the region. The site, which extends over approximately one hectare, is for several years the object of numerous archaeological studies and is at the heart of a project of valuation of the vestiges today. It was indeed a key objective, among the numerous planned works, to realize a 3D model of the site in its current state, in other words, a virtual model "such as seized", exploitable as well from a cultural and tourist point of view as by scientists and in archaeological researches. The team of the ICube/INSA lab had in responsibility the realization of this model, the acquisition of the data until the delivery of the virtual model, thanks to 3D TLS and topographic surveying methods. It was also planned to integrate into this 3D model, data of 2D archives, stemming from series of former excavations. The objectives of this project were the following ones: • Acquisition of 3D digital data of the site and 3D modelling • Digitization of the 2D archaeological data and integration in the 3D model • Implementation of a database connected to the 3D model • Virtual Visit of the site The obtained results allowed us to visualize every 3D object individually, under several forms (point clouds, 3D meshed objects and models, etc.) and at several levels of detail
Fisheye Lenses for 3d Modeling: Evaluations and Considerations
NASA Astrophysics Data System (ADS)
Barazzetti, L.; Previtali, M.; Roncoroni, F.
2017-02-01
Fisheye lenses are becoming more popular in complete image-based modelling projects of small and narrow spaces. The growing interest in fisheye lenses is confirmed by the availability of different commercial software incorporating a fisheye camera model. Such software are now able to carry out the steps of the image processing pipeline in a fully automated way, from camera calibration and orientation to dense matching, surface generation, and orthophoto production. This paper highlights the advantages (and disadvantages) of fisheye lenses when used for 3D modelling projects through different commercial software. The goal is not only a comparison of commercial software, but also an analysis of the additional issues that arise when a fisheye lens is used for 3D modelling. Results confirm that a fisheye lens is suitable for accurate metric documentation, especially when limited space is available. On the other hand, additional issues where found during the camera calibration/image orientation step as well as the texture generation and orthophoto production phases, for which particular attention is required.
3-d Periodic Packaging: Sodalite, a Model System
1992-05-15
to 05-31-92 4. TITLE AND SUBTITLE S. FUNDING NUMBERS 3-d Periodic Packaging: N00014-90-J-1159 Sodalite , A Model System 6. AUTHOR(S) G.D. Stucky, V.I...assembly of confined atomic and molecular arrays. Sodalite , one of the simplest zeolite analogue structures with a 60 atom cage can be synthesized with...structure of both the frameworks and the clusters within the cages of sodalite structural analogues can be precisely determined. In addition to new
3-D Periodic Packaging: Sodalite, a Model System
1992-05-15
hfww 05-15-92 Technical 06-1-91 o 05-31-92 ,mA AMU SUBSTIl SI. FUNDING NUMBUS 3-d Periodic Packaging: Sodalite , A Model System N00014-81-K-0598 AUTNO(S...considerable latitude in the assembly of confined atomic and molecular arrays. Sodalite , one of the simplest zeolite analogue structures with a 60 atom...framework electric field. The structure of both the fiameworks and the clusters within the cages of sodalite structural analogues can be precisely
NASA Astrophysics Data System (ADS)
Bournez, E.; Landes, T.; Saudreau, M.; Kastendeuch, P.; Najjar, G.
2017-02-01
3D models of tree geometry are important for numerous studies, such as for urban planning or agricultural studies. In climatology, tree models can be necessary for simulating the cooling effect of trees by estimating their evapotranspiration. The literature shows that the more accurate the 3D structure of a tree is, the more accurate microclimate models are. This is the reason why, since 2013, we have been developing an algorithm for the reconstruction of trees from terrestrial laser scanner (TLS) data, which we call TreeArchitecture. Meanwhile, new promising algorithms dedicated to tree reconstruction have emerged in the literature. In this paper, we assess the capacity of our algorithm and of two others -PlantScan3D and SimpleTree- to reconstruct the 3D structure of trees. The aim of this reconstruction is to be able to characterize the geometric complexity of trees, with different heights, sizes and shapes of branches. Based on a specific surveying workflow with a TLS, we have acquired dense point clouds of six different urban trees, with specific architectures, before reconstructing them with each algorithm. Finally, qualitative and quantitative assessments of the models are performed using reference tree reconstructions and field measurements. Based on this assessment, the advantages and the limits of every reconstruction algorithm are highlighted. Anyway, very satisfying results can be reached for 3D reconstructions of tree topology as well as of tree volume.
3D-FEM electrical-thermal-mechanical analysis and experiment of Si-based MEMS infrared emitters
NASA Astrophysics Data System (ADS)
Wang, Xiang; Wang, Na; Chen, Ran-Bin; San, Hai-Sheng; Chen, Xu-Yuan
2016-11-01
Designs, simulations, and fabrications of silicon-based MEMS infrared (IR) emitters for gas sensing application are presented. A 3D finite element method (3D-FEM) was used to analyze the coupled electrical-thermal-mechanical properties of a bridge hotplate structure (BHS) IR emitter and closed hotplate structure (CHS) IR emitter using Joule heating and thermal expansion models of COMSOL™. The IR absorptions of n- and p-silicon were calculated for the design of self-heating structure. The BHS and CHS IR emitters were fabricated synchronously using micro-electromechanical systems technology for a direct performance comparison. Both types of IR emitters were characterized by electrical and optical measurements. The experimental results show that BHS IR emitters have higher radiation density, lower power consumption, and faster frequency-response than CHS IR emitters due to the use of a thermal isolation structure and self-heating structure. Meanwhile, the simulated results agree well with the corresponding measured results, which indicate that the 3D-FEM-model is effective and can be used in the optimal design of electro-thermal devices.
Computational model of mesenchymal migration in 3D under chemotaxis
Ribeiro, F. O.; Gómez-Benito, M. J.; Folgado, J.; Fernandes, P. R.; García-Aznar, J. M.
2017-01-01
Abstract Cell chemotaxis is an important characteristic of cellular migration, which takes part in crucial aspects of life and development. In this work, we propose a novel in silico model of mesenchymal 3D migration with competing protrusions under a chemotactic gradient. Based on recent experimental observations, we identify three main stages that can regulate mesenchymal chemotaxis: chemosensing, dendritic protrusion dynamics and cell–matrix interactions. Therefore, each of these features is considered as a different module of the main regulatory computational algorithm. The numerical model was particularized for the case of fibroblast chemotaxis under a PDGF-bb gradient. Fibroblasts migration was simulated embedded in two different 3D matrices – collagen and fibrin – and under several PDGF-bb concentrations. Validation of the model results was provided through qualitative and quantitative comparison with in vitro studies. Our numerical predictions of cell trajectories and speeds were within the measured in vitro ranges in both collagen and fibrin matrices. Although in fibrin, the migration speed of fibroblasts is very low, because fibrin is a stiffer and more entangling matrix. Testing PDGF-bb concentrations, we noticed that an increment of this factor produces a speed increment. At 1 ng mL−1 a speed peak is reached after which the migration speed diminishes again. Moreover, we observed that fibrin exerts a dampening behavior on migration, significantly affecting the migration efficiency. PMID:27336322
Computational model of mesenchymal migration in 3D under chemotaxis.
Ribeiro, F O; Gómez-Benito, M J; Folgado, J; Fernandes, P R; García-Aznar, J M
2017-01-01
Cell chemotaxis is an important characteristic of cellular migration, which takes part in crucial aspects of life and development. In this work, we propose a novel in silico model of mesenchymal 3D migration with competing protrusions under a chemotactic gradient. Based on recent experimental observations, we identify three main stages that can regulate mesenchymal chemotaxis: chemosensing, dendritic protrusion dynamics and cell-matrix interactions. Therefore, each of these features is considered as a different module of the main regulatory computational algorithm. The numerical model was particularized for the case of fibroblast chemotaxis under a PDGF-bb gradient. Fibroblasts migration was simulated embedded in two different 3D matrices - collagen and fibrin - and under several PDGF-bb concentrations. Validation of the model results was provided through qualitative and quantitative comparison with in vitro studies. Our numerical predictions of cell trajectories and speeds were within the measured in vitro ranges in both collagen and fibrin matrices. Although in fibrin, the migration speed of fibroblasts is very low, because fibrin is a stiffer and more entangling matrix. Testing PDGF-bb concentrations, we noticed that an increment of this factor produces a speed increment. At 1 ng mL(-1) a speed peak is reached after which the migration speed diminishes again. Moreover, we observed that fibrin exerts a dampening behavior on migration, significantly affecting the migration efficiency.
Simulation of 3D Global Wave Propagation Through Geodynamic Models
NASA Astrophysics Data System (ADS)
Schuberth, B.; Piazzoni, A.; Bunge, H.; Igel, H.; Steinle-Neumann, G.
2005-12-01
This project aims at a better understanding of the forward problem of global 3D wave propagation. We use the spectral element program "SPECFEM3D" (Komatitsch and Tromp, 2002a,b) with varying input models of seismic velocities derived from mantle convection simulations (Bunge et al., 2002). The purpose of this approach is to obtain seismic velocity models independently from seismological studies. In this way one can test the effects of varying parameters of the mantle convection models on the seismic wave field. In order to obtain the seismic velocities from the temperature field of the geodynamical simulations we follow a mineral physics approach. Assuming a certain mantle composition (e.g. pyrolite with CMASF composition) we compute the stable phases for each depth (i.e. pressure) and temperature by system Gibbs free energy minimization. Elastic moduli and density are calculated from the equations of state of the stable mineral phases. For this we use a mineral physics database derived from calorimetric experiments (enthalphy and entropy of formation, heat capacity) and EOS parameters.
Image sequence coding using 3D scene models
NASA Astrophysics Data System (ADS)
Girod, Bernd
1994-09-01
The implicit and explicit use of 3D models for image sequence coding is discussed. For implicit use, a 3D model can be incorporated into motion compensating prediction. A scheme that estimates the displacement vector field with a rigid body motion constraint by recovering epipolar lines from an unconstrained displacement estimate and then repeating block matching along the epipolar line is proposed. Experimental results show that an improved displacement vector field can be obtained with a rigid body motion constraint. As an example for explicit use, various results with a facial animation model for videotelephony are discussed. A 13 X 16 B-spline mask can be adapted automatically to individual faces and is used to generate facial expressions based on FACS. A depth-from-defocus range camera suitable for real-time facial motion tracking is described. Finally, the real-time facial animation system `Traugott' is presented that has been used to generate several hours of broadcast video. Experiments suggest that a videophone system based on facial animation might require a transmission bitrate of 1 kbit/s or below.
Pose invariant face recognition: 3D model from single photo
NASA Astrophysics Data System (ADS)
Napoléon, Thibault; Alfalou, Ayman
2017-02-01
Face recognition is widely studied in the literature for its possibilities in surveillance and security. In this paper, we report a novel algorithm for the identification task. This technique is based on an optimized 3D modeling allowing to reconstruct faces in different poses from a limited number of references (i.e. one image by class/person). Particularly, we propose to use an active shape model to detect a set of keypoints on the face necessary to deform our synthetic model with our optimized finite element method. Indeed, in order to improve our deformation, we propose a regularization by distances on graph. To perform the identification we use the VanderLugt correlator well know to effectively address this task. On the other hand we add a difference of Gaussian filtering step to highlight the edges and a description step based on the local binary patterns. The experiments are performed on the PHPID database enhanced with our 3D reconstructed faces of each person with an azimuth and an elevation ranging from -30° to +30°. The obtained results prove the robustness of our new method with 88.76% of good identification when the classic 2D approach (based on the VLC) obtains just 44.97%.
Heralding a new paradigm in 3D tumor modeling.
Fong, Eliza L S; Harrington, Daniel A; Farach-Carson, Mary C; Yu, Hanry
2016-11-01
Numerous studies to date have contributed to a paradigm shift in modeling cancer, moving from the traditional two-dimensional culture system to three-dimensional (3D) culture systems for cancer cell culture. This led to the inception of tumor engineering, which has undergone rapid advances over the years. In line with the recognition that tumors are not merely masses of proliferating cancer cells but rather, highly complex tissues consisting of a dynamic extracellular matrix together with stromal, immune and endothelial cells, significant efforts have been made to better recapitulate the tumor microenvironment in 3D. These approaches include the development of engineered matrices and co-cultures to replicate the complexity of tumor-stroma interactions in vitro. However, the tumor engineering and cancer biology fields have traditionally relied heavily on the use of cancer cell lines as a cell source in tumor modeling. While cancer cell lines have contributed to a wealth of knowledge in cancer biology, the use of this cell source is increasingly perceived as a major contributing factor to the dismal failure rate of oncology drugs in drug development. Backing this notion is the increasing evidence that tumors possess intrinsic heterogeneity, which predominantly homogeneous cancer cell lines poorly reflect. Tumor heterogeneity contributes to therapeutic resistance in patients. To overcome this limitation, cancer cell lines are beginning to be replaced by primary tumor cell sources, in the form of patient-derived xenografts and organoids cultures. Moving forward, we propose that further advances in tumor engineering would require that tumor heterogeneity (tumor variants) be taken into consideration together with tumor complexity (tumor-stroma interactions). In this review, we provide a comprehensive overview of what has been achieved in recapitulating tumor complexity, and discuss the importance of incorporating tumor heterogeneity into 3D in vitro tumor models. This
Conformal cooling and rapid thermal cycling in injection molding with 3D printed tools
NASA Astrophysics Data System (ADS)
Xu, Xiaorong
Solid Freeform Fabrication processes such as 3D Printing have demonstrated the potential to produce tools with complex internal geometry. This work explores the application of this capability to improved thermal management for injection molding tooling through: (i)cooling lines which are conformal to the mold surface which provide improved uniformity and stability of mold temperature and (ii)tools with low thermal inertia which, in combination with conformal fluid channels allow for rapid heating and cooling of tooling, thereby facilitating isothermal filling of the mold cavity. This work presents a systematic, modular, approach to the design of conformal cooling channels. Recognizing that the cooling is local to the surface of the tool, the tool is divided up into geometric regions and a channel system is designed for each region. Each channel system is itself modeled as composed of cooling elements, typically the region spanned by two channels. Six criteria are applied including; a transient heat transfer condition which dictates a maximum distance from mold surface to cooling channel, considerations of pressure and temperature drop along the flow channel and considerations of strength of the mold. These criteria are treated as constraints and successful designs are sought which define windows bounded by these constraints. The methodology is demonstrated in application to a complex core and cavity for injection molding. In the area of rapid thermal cycling, this work utilizes the design methods for conformal channels for the heating phases and adds analysis of the packing and cooling phases. A design is created which provides thermal isolation and accommodation of cyclic thermal stresses though an array of bendable support columns which support the molding portion of the tool where the heating/cooling channels are contained. Designed elasticity of the tool is used to aid in packing of the polymer during the cooling phase. Methodology for the design of this
ERIC Educational Resources Information Center
Rowe, Jeremy; Razdan, Anshuman
The Partnership for Research in Spatial Modeling (PRISM) project at Arizona State University (ASU) developed modeling and analytic tools to respond to the limitations of two-dimensional (2D) data representations perceived by affiliated discipline scientists, and to take advantage of the enhanced capabilities of three-dimensional (3D) data that…
Canada in 3D - Toward a Sustainable 3D Model for Canadian Geology from Diverse Data Sources
NASA Astrophysics Data System (ADS)
Brodaric, B.; Pilkington, M.; Snyder, D. B.; St-Onge, M. R.; Russell, H.
2015-12-01
Many big science issues span large areas and require data from multiple heterogeneous sources, for example climate change, resource management, and hazard mitigation. Solutions to these issues can significantly benefit from access to a consistent and integrated geological model that would serve as a framework. However, such a model is absent for most large countries including Canada, due to the size of the landmass and the fragmentation of the source data into institutional and disciplinary silos. To overcome these barriers, the "Canada in 3D" (C3D) pilot project was recently launched by the Geological Survey of Canada. C3D is designed to be evergreen, multi-resolution, and inter-disciplinary: (a) it is to be updated regularly upon acquisition of new data; (b) portions vary in resolution and will initially consist of four layers (surficial, sedimentary, crystalline, and mantle) with intermediary patches of higher-resolution fill; and (c) a variety of independently managed data sources are providing inputs, such as geophysical, 3D and 2D geological models, drill logs, and others. Notably, scalability concerns dictate a decentralized and interoperable approach, such that only key control objects, denoting anchors for the modeling process, are imported into the C3D database while retaining provenance links to original sources. The resultant model is managed in the database, contains full modeling provenance as well as links to detailed information on rock units, and is to be visualized in desktop and online environments. It is anticipated that C3D will become the authoritative state of knowledge for the geology of Canada at a national scale.
RELAP5-3D Code Includes Athena Features and Models
Richard A. Riemke; Cliff B. Davis; Richard R. Schultz
2006-07-01
Version 2.3 of the RELAP5-3D computer program includes all features and models previously available only in the ATHENA version of the code. These include the addition of new working fluids (i.e., ammonia, blood, carbon dioxide, glycerol, helium, hydrogen, lead-bismuth, lithium, lithium-lead, nitrogen, potassium, sodium, and sodium-potassium) and a magnetohydrodynamic model that expands the capability of the code to model many more thermal-hydraulic systems. In addition to the new working fluids along with the standard working fluid water, one or more noncondensable gases (e.g., air, argon, carbon dioxide, carbon monoxide, helium, hydrogen, krypton, nitrogen, oxygen, sf6, xenon) can be specified as part of the vapor/gas phase of the working fluid. These noncondensable gases were in previous versions of RELAP5- 3D. Recently four molten salts have been added as working fluids to RELAP5-3D Version 2.4, which has had limited release. These molten salts will be in RELAP5-3D Version 2.5, which will have a general release like RELAP5-3D Version 2.3. Applications that use these new features and models are discussed in this paper.
Thermal characterization of a liquid resin for 3D printing using photothermal techniques
NASA Astrophysics Data System (ADS)
Jiménez-Pérez, José L.; Pincel, Pavel Vieyra; Cruz-Orea, Alfredo; Correa-Pacheco, Zormy N.
2016-05-01
Thermal properties of a liquid resin were studied by thermal lens spectrometry (TLS) and open photoacoustic cell (OPC), respectively. In the case of the TLS technique, the two mismatched mode experimental configuration was used with a He-Ne laser, as a probe beam and an Argon laser was used as the excitation source. The characteristic time constant of the transient thermal lens was obtained by fitting the theoretical expression to the experimental data in order to obtain the thermal diffusivity ( α) of the resin. On the other hand, the sample thermal effusivity ( e) was obtained by using the OPC technique. In this technique, an Argon laser was used as the excitation source and was operated at 514 nm with an output power of 30 mW. From the obtained thermal diffusivity ( α) and thermal effusivity ( e) values, the thermal conductivity ( k) and specific heat capacity per unit volume ( ρc) of resin were calculated through the relationships k = e( α)1/2 and ρc = e/( α)1/2. The obtained thermal parameters were compared with the thermal parameters of the literature. To our knowledge, the thermal characterization of resin has not been reported until now. The present study has applications in laser stereo-lithography to manufacture 3D printing pieces.
3-D physical models of mitosis (with asters) and cytokinesis.
Cheng, Kang; Zou, Changhua
2004-01-01
First, we define new concepts of Life Objects, Informative Objects and Virtual Objects, Discrete Chromosome Rings (DCR); we introduce a mathematical concept of meridian plane (MP) in a three dimensional (3-D) cylindrical coordinate system (CCS). Based on these concepts, classic mechanics, classic electromagnetism and published biological data, we develop our 3-D physical models of natural and normal mitosis (with asters) and cytokinesis, for animal cells in M phase. We propose following hypotheses: Chromosomes Exclusion: No normally and naturally replicated chromosomes can occupy the same nucleus without growing sizes of the nucleus and the cell. Spontaneous and strong electromagnetic fields (EMF) forces among chromosomes, centrosomes and microtubules split the nucleus and separate the two sets of sister chromatids when they are strong enough. Nuclei Exclusion: No normally and naturally doubled nuclei can occupy the same cell if the doubled size of nuclei is not far smaller than size of the cell. The spontaneous and strong EMF forces in protoplasm (or cortex), separate two sets of chromosomes, spindles and poles, drive contractile proteins to the equator in cell cortex, and continue to guide and to transport free charged objects until complete the cytokinesis. Centrioles Exclusion: No naturally and normally doubled centrioles can occupy the same centrosome. The spontaneous and strong repulsive EMF forces are the primary cause for the exclusions. The principles of our models are also applied to mitosis and cytokinesis for lower plant cells, to that of multiple nuclei or mutant chromosomes, and to meiosis, for both animal cells and lower plant cells.
High-resolution 3D digital models of artworks
NASA Astrophysics Data System (ADS)
Fontana, Raffaella; Gambino, Maria Chiara; Greco, Marinella; Pampaloni, Enrico; Pezzati, Luca; Scopigno, Roberto
2003-10-01
The measurement of the shape of an artwork usually requires a high-resolution instrumentation, in order to catch small details such as chisel marks, sculptural relieves, surface cracks, etc. 3D scanning techniques, together with new modeling software tools, allow a high fidelity reproduction of an artwork: these can be applied either to support and document its repair or for the realization of 3D archives and virtual museums. Starting from a high-resolution digital model of an object, a further step could be its reproduction by means of fast-prototyping techniques like stereo-lithography or electro-erosion. This work is aimed at showing the performance of a high-resolution laser scanner devoted to Cultural Heritage applications. The device is portable and very versatile, in order to allow in situ applications, accurate and reliable, so to capture intricate details. This laser profilometer has been used in a few surveys, the most significant of which are the monitoring the various phases of the restoration process of an ellenistic bronze (the Minerva of Arezzo, Florence), the cataloguing of some archaeological findings (from the Grotta della Poesia, Lecce) and the documenting of wooden panels surface conditions (the "Madonna del Cardellino" by Raffaello and "La Tebaide" by Beato Angelico).
In Silico 3D Modeling of Binding Activities.
Moro, Stefano; Sturlese, Mattia; Ciancetta, Antonella; Floris, Matteo
2016-01-01
In silico three-dimensional (3D) molecular modeling tools based upon the receptor/enzyme-ligand docking simulation in protein crystal structures and/or homology modeling of receptors have been reliably used in pharmacological research and development for decades. Molecular docking methodologies are helpful for revealing facets of activation and inactivation, thus improving mechanistic understanding and predicting molecular ligand binding activity, and they can have a high level of accuracy, and have also been explored and applied in chemical risk assessment. This computational approach is, however, only applicable for chemical hazard identification situations where the specific target receptor for a given chemical is known and the crystal structure/homology model of the receptor is available.
Dynamic deformable models for 3D MRI heart segmentation
NASA Astrophysics Data System (ADS)
Zhukov, Leonid; Bao, Zhaosheng; Gusikov, Igor; Wood, John; Breen, David E.
2002-05-01
Automated or semiautomated segmentation of medical images decreases interstudy variation, observer bias, and postprocessing time as well as providing clincally-relevant quantitative data. In this paper we present a new dynamic deformable modeling approach to 3D segmentation. It utilizes recently developed dynamic remeshing techniques and curvature estimation methods to produce high-quality meshes. The approach has been implemented in an interactive environment that allows a user to specify an initial model and identify key features in the data. These features act as hard constraints that the model must not pass through as it deforms. We have employed the method to perform semi-automatic segmentation of heart structures from cine MRI data.
Stochastic Modeling of Calcium in 3D Geometry
Mazel, Tomáš; Raymond, Rebecca; Raymond-Stintz, Mary; Jett, Stephen; Wilson, Bridget S.
2009-01-01
Release of inflammatory mediators by mast cells in type 1 immediate-hypersensitivity allergic reactions relies on antigen-dependent increases in cytosolic calcium. Here, we used a series of electron microscopy images to build a 3D reconstruction representing a slice through a rat tumor mast cell, which then served as a basis for stochastic modeling of inositol-trisphosphate-mediated calcium responses. The stochastic approach was verified by reaction-diffusion modeling within the same geometry. Local proximity of the endoplasmic reticulum to either the plasma membrane or mitochondria is predicted to differentially impact local inositol trisphosphate receptor transport. The explicit consideration of organelle spatial relationships represents an important step toward building a comprehensive, realistic model of cellular calcium dynamics. PMID:19254531
Development of an aquifer management model AQMAN3D
Puig, Juan Carlos; Rolon-Collazo, L. I.; Pagan-Trinidad, Ishmael; Krishna, J.H.; Quinones-Aponte, Vicente; Gomez-Gomez, Fernando; Morris, G.L.
1990-01-01
A computer code that enables the use of the USGS Modular groundwater flow model for aquifermanagement modeling has been developed. Aquifermanagement techniques integrate groundwater flow modeling with linear quadratic optimization methods for the solution of various aquifer management problems. The model AQMAN3D, is a modified version of a previously developed two-dimensional AQMAN model. The idea of coupling the AQMAN model with the MODULAR model arose because actual groundwater flow systems behave in a three dimensional manner, therefore requiring treatment as such, and due to the widespread use of MODULAR. The use of the AQMAN3D model permits the implementation of the technique known as aquifer managementmodeling. A generalized approach to obtain an optimal solution to an aquifer management problem is proposed, and a sample test problem is presented to illustrate the use of the model. Even though the model provides the hydrologist with a new and powerful investigative tool, its applicability is limited to confined or quasiconfined systems.
Extreme low thermal conductivity in nanoscale 3D Si phononic crystal with spherical pores.
Yang, Lina; Yang, Nuo; Li, Baowen
2014-01-01
In this work, we propose a nanoscale three-dimensional (3D) Si phononic crystal (PnC) with spherical pores, which can reduce the thermal conductivity of bulk Si by a factor up to 10,000 times at room temperature. Thermal conductivity of Si PnCs depends on the porosity, for example, the thermal conductivity of Si PnCs with porosity 50% is 300 times smaller than that of bulk Si. The phonon participation ratio spectra demonstrate that more phonons are localized as the porosity increases. The thermal conductivity is insensitive to the temperature changes from room temperature to 1100 K. The extreme-low thermal conductivity could lead to a larger value of ZT than unity as the periodic structure affects very little the electric conductivity.
Geomorphological maps and 3d models in cave research
NASA Astrophysics Data System (ADS)
Ballesteros, Daniel; Jiménez-Sánchez, Montserrat; José Domínguez-Cuesta, María
2013-04-01
Cave geomorphological processes and features can be studied by geomorphological maps although topographic maps, aerial photos and GPS are not available. Methods in cave geomorphological mapping are conditioned by cave environment configuration, the need of using speleological techniques, and limitations arising from the projection of the 3D data from the cave to a 2D plan. Some of our previous works in the Cantabrian Mountains and Cantabrian Coast (NW Spain) established the approach of the design of cave geomorphological maps and its legend. Today we are improving the display of cave process combining geomorphological maps and 3d models based on the experience obtained from the research of one cave from the Cantabrian Coast and four caves in the Picos de Europa National Park (funded by GEOCAVE project, Spanish National Parks Agency). The five caves are developed in Carboniferous limestone affected by faults and thrusts. The method of work includes: 1) the elaboration of the cave survey at 1:50 to 1:500 scale; 2) the check of the cave survey of three caves by closed loops; 3) the mapping of cave features based on the performed survey; 4) the 3d modeling of the caves approximating each survey shoot by an octagonal prism; and 5) the implementation and management of the survey and geomorphological map in a Geographic Information System. Based on the survey, the cavities are small caves to deep alpine shafts with 281 to 4,438 m length and up to 738 m deep. The precision of the cave maps only could be estimated in two caves at a cavity scale, displaying both of them a 2.49 % error. The prisms of the 3d model was classified into four groups according to the morphology of the cave passage: 1) canyons, 2) phreatic and epiphreatic tubes, 3) soutirage conduits, 4) mixed forms composed by phreatic and epiphreatic tubes modified by fluvial incision, 5) pitches and 6) irregular passages enlarged strongly by gravity process. According to our previous works geomorphological
Geographic Video 3d Data Model And Retrieval
NASA Astrophysics Data System (ADS)
Han, Z.; Cui, C.; Kong, Y.; Wu, H.
2014-04-01
Geographic video includes both spatial and temporal geographic features acquired through ground-based or non-ground-based cameras. With the popularity of video capture devices such as smartphones, the volume of user-generated geographic video clips has grown significantly and the trend of this growth is quickly accelerating. Such a massive and increasing volume poses a major challenge to efficient video management and query. Most of the today's video management and query techniques are based on signal level content extraction. They are not able to fully utilize the geographic information of the videos. This paper aimed to introduce a geographic video 3D data model based on spatial information. The main idea of the model is to utilize the location, trajectory and azimuth information acquired by sensors such as GPS receivers and 3D electronic compasses in conjunction with video contents. The raw spatial information is synthesized to point, line, polygon and solid according to the camcorder parameters such as focal length and angle of view. With the video segment and video frame, we defined the three categories geometry object using the geometry model of OGC Simple Features Specification for SQL. We can query video through computing the spatial relation between query objects and three categories geometry object such as VFLocation, VSTrajectory, VSFOView and VFFovCone etc. We designed the query methods using the structured query language (SQL) in detail. The experiment indicate that the model is a multiple objective, integration, loosely coupled, flexible and extensible data model for the management of geographic stereo video.
Zhang, Qiangqiang; Hao, Menglong; Xu, Xiang; Xiong, Guoping; Li, Hui; Fisher, Timothy S
2017-04-14
In this article, flyweight three-dimensional (3D) graphene scaffolds (GSs) have been demonstrated with a microinterface barrier-derived thermal insulation and flame retardancy characteristics. Such 3D GSs were fabricated by a modified hydrothermal method and a unidirectional freeze-casting process with hierarchical porous microstructures. Because of high porosity (99.9%), significant phonon scattering, and strong π-π interaction at the interface barriers of multilayer graphene cellular walls, the GSs demonstrate a sequence of multifunctional properties simultaneously, such as lightweight density, thermal insulating characteristics, and outstanding mechanical robustness. At 100 °C, oxidized GSs exhibit a thermal conductivity of 0.0126 ± 0.0010 W/(m K) in vacuum. The thermal conductivity of oxidized GSs remains relatively unaffected despite large-scale deformation-induced densification of the microstructures, as compared to the behavior of reduced GSs (rGSs) whose thermal conductivity increases dramatically under compression. The contrasting behavior of oxidized GSs and rGSs appears to derive from large differences in the intersheet contact resistance and varying intrinsic thermal conductivity between reduced and oxidized graphene sheets. The oxidized GSs also exhibit excellent flame retardant behavior and mechanical robustness, with only 2% strength decay after flame treatment. In a broader context, this work demonstrates a useful strategy to design porous nanomaterials with a tunable heat conduction behavior through interface engineering at the nanoscale.
3D modeling of satellite spectral images, radiation budget and energy budget of urban landscapes
NASA Astrophysics Data System (ADS)
Gastellu-Etchegorry, J. P.
2008-12-01
DART EB is a model that is being developed for simulating the 3D (3 dimensional) energy budget of urban and natural scenes, possibly with topography and atmosphere. It simulates all non radiative energy mechanisms (heat conduction, turbulent momentum and heat fluxes, water reservoir evolution, etc.). It uses DART model (Discrete Anisotropic Radiative Transfer) for simulating radiative mechanisms: 3D radiative budget of 3D scenes and their remote sensing images expressed in terms of reflectance or brightness temperature values, for any atmosphere, wavelength, sun/view direction, altitude and spatial resolution. It uses an innovative multispectral approach (ray tracing, exact kernel, discrete ordinate techniques) over the whole optical domain. This paper presents two major and recent improvements of DART for adapting it to urban canopies. (1) Simulation of the geometry and optical characteristics of urban elements (houses, etc.). (2) Modeling of thermal infrared emission by vegetation and urban elements. The new DART version was used in the context of the CAPITOUL project. For that, districts of the Toulouse urban data base (Autocad format) were translated into DART scenes. This allowed us to simulate visible, near infrared and thermal infrared satellite images of Toulouse districts. Moreover, the 3D radiation budget was used by DARTEB for simulating the time evolution of a number of geophysical quantities of various surface elements (roads, walls, roofs). Results were successfully compared with ground measurements of the CAPITOUL project.
Modeling tree crown dynamics with 3D partial differential equations
Beyer, Robert; Letort, Véronique; Cournède, Paul-Henry
2014-01-01
We characterize a tree's spatial foliage distribution by the local leaf area density. Considering this spatially continuous variable allows to describe the spatiotemporal evolution of the tree crown by means of 3D partial differential equations. These offer a framework to rigorously take locally and adaptively acting effects into account, notably the growth toward light. Biomass production through photosynthesis and the allocation to foliage and wood are readily included in this model framework. The system of equations stands out due to its inherent dynamic property of self-organization and spontaneous adaptation, generating complex behavior from even only a few parameters. The density-based approach yields spatially structured tree crowns without relying on detailed geometry. We present the methodological fundamentals of such a modeling approach and discuss further prospects and applications. PMID:25101095
3D Tissue-Engineered Model of Ewing Sarcoma
Lamhamedi-Cherradi, Salah-Eddine; Santoro, Marco; Ramammoorthy, Vandhana; Menegaz, Brian A.; Bartholomeusz, Geoffrey; Iles, Lakesla R.; Amin, Hesham M.; Livingston, Andrew J.; Mikos, Antonios G.; Ludwig, Joseph A.
2015-01-01
Despite longstanding reliance upon monolayer culture for studying cancer cells, and numerous advantages from both a practical and experimental standpoint, a growing body of evidence suggests more complex three-dimensional (3D) models are necessary to properly mimic many of the critical hallmarks associated with the oncogenesis, maintenance and spread of Ewing sarcoma (ES), the second most common pediatric bone tumor. And as clinicians increasingly turn to biologically-targeted therapies that exert their effects not only on the tumor cells themselves, but also on the surrounding extracellular matrix, it is especially important that preclinical models evolve in parallel to reliably measure antineoplastic effects and possible mechanisms of de novo and acquired drug resistance. Herein, we highlight a number of innovative methods used to fabricate biomimetic ES tumors, encompassing both the surrounding cellular milieu and extracellular matrix (ECM), and suggest potential applications to advance our understanding of ES biology, preclinical drug testing, and personalized medicine. PMID:25109853
3D Model of the Eta Carinae Little Homunculus Nebula
NASA Astrophysics Data System (ADS)
Steffen, Wolfgang; Teodoro, Mairan; Madura, Thomas; Groh, Jose H.; Gull, Theodore R.; Corcoran, Michael F.; Damineli, Augusto; Hamaguchi, Kenji
2015-01-01
We extend our morpho-kinematic 3D modeling of the Homunculus nebula (Steffen et al., 2014) to the interior nested Little Homunculus. The model is based on spectroscopic observations from HST/STIS. We find that the structure of the interior Little Homunculus is rather flat in the polar regions and interacts with the main Homunculus nebula only on one side, towards the periastron direction of the binary orbit. Furthermore, the two lobes of the LH are misaligned, also towards the periastron direction. As an explanation for the misalignment we propose that, in both cases, shortly after the eruptions that created the bipolar nebulae from the primary star, the off-center wind of the secondary has pushed the ejecta towards the periastron directions, since the secondary is most of the time near the apastron. Future hydrodynamic simulations are warranted to confirm this scenario.
Plasticized protein for 3D printing by fused deposition modeling
NASA Astrophysics Data System (ADS)
Chaunier, Laurent; Leroy, Eric; Della Valle, Guy; Lourdin, Denis
2016-10-01
The developments of Additive Manufacturing (AM) by Fused Deposition Modeling (FDM) now target new 3D printable materials, leading to novel properties like those given by biopolymers such as proteins: degradability, biocompatibility and edibility. Plasticized materials from zein, a storage protein issued from corn, present interesting thermomechanical and rheological properties, possibly matching with AM-FDM specifications. Thus commercial zein plasticized with 20% glycerol has a glass transition temperature (Tg) at about 42°C, after storage at intermediate relative humidity (RH=59%). Its principal mechanical relaxation at Tα ≈ 50°C leads to a drop of the elastic modulus from about 1.1 GPa, at ambient temperature, to 0.6 MPa at Tα+100°C. These values are in the same range as values obtained in the case of standard polymers for AM-FDM processing, as PLA and ABS, although relaxation mechanisms are likely different in these materials. Such results lead to the setting up of zein-based compositions printable by AM-FDM and allow processing bioresorbable printed parts, with designed 3D geometry and structure.
Gene3D: modelling protein structure, function and evolution.
Yeats, Corin; Maibaum, Michael; Marsden, Russell; Dibley, Mark; Lee, David; Addou, Sarah; Orengo, Christine A
2006-01-01
The Gene3D release 4 database and web portal (http://cathwww.biochem.ucl.ac.uk:8080/Gene3D) provide a combined structural, functional and evolutionary view of the protein world. It is focussed on providing structural annotation for protein sequences without structural representatives--including the complete proteome sets of over 240 different species. The protein sequences have also been clustered into whole-chain families so as to aid functional prediction. The structural annotation is generated using HMM models based on the CATH domain families; CATH is a repository for manually deduced protein domains. Amongst the changes from the last publication are: the addition of over 100 genomes and the UniProt sequence database, domain data from Pfam, metabolic pathway and functional data from COGs, KEGG and GO, and protein-protein interaction data from MINT and BIND. The website has been rebuilt to allow more sophisticated querying and the data returned is presented in a clearer format with greater functionality. Furthermore, all data can be downloaded in a simple XML format, allowing users to carry out complex investigations at their own computers.
3D in vitro modeling of the central nervous system
Hopkins, Amy M.; DeSimone, Elise; Chwalek, Karolina; Kaplan, David L.
2015-01-01
There are currently more than 600 diseases characterized as affecting the central nervous system (CNS) which inflict neural damage. Unfortunately, few of these conditions have effective treatments available. Although significant efforts have been put into developing new therapeutics, drugs which were promising in the developmental phase have high attrition rates in late stage clinical trials. These failures could be circumvented if current 2D in vitro and in vivo models were improved. 3D, tissue-engineered in vitro systems can address this need and enhance clinical translation through two approaches: (1) bottom-up, and (2) top-down (developmental/regenerative) strategies to reproduce the structure and function of human tissues. Critical challenges remain including biomaterials capable of matching the mechanical properties and extracellular matrix (ECM) composition of neural tissues, compartmentalized scaffolds that support heterogeneous tissue architectures reflective of brain organization and structure, and robust functional assays for in vitro tissue validation. The unique design parameters defined by the complex physiology of the CNS for construction and validation of 3D in vitro neural systems are reviewed here. PMID:25461688
3D in vitro modeling of the central nervous system.
Hopkins, Amy M; DeSimone, Elise; Chwalek, Karolina; Kaplan, David L
2015-02-01
There are currently more than 600 diseases characterized as affecting the central nervous system (CNS) which inflict neural damage. Unfortunately, few of these conditions have effective treatments available. Although significant efforts have been put into developing new therapeutics, drugs which were promising in the developmental phase have high attrition rates in late stage clinical trials. These failures could be circumvented if current 2D in vitro and in vivo models were improved. 3D, tissue-engineered in vitro systems can address this need and enhance clinical translation through two approaches: (1) bottom-up, and (2) top-down (developmental/regenerative) strategies to reproduce the structure and function of human tissues. Critical challenges remain including biomaterials capable of matching the mechanical properties and extracellular matrix (ECM) composition of neural tissues, compartmentalized scaffolds that support heterogeneous tissue architectures reflective of brain organization and structure, and robust functional assays for in vitro tissue validation. The unique design parameters defined by the complex physiology of the CNS for construction and validation of 3D in vitro neural systems are reviewed here.
Modeling approaches for ligand-based 3D similarity.
Tresadern, Gary; Bemporad, Daniele
2010-10-01
3D ligand-based similarity approaches are widely used in the early phases of drug discovery for tasks such as hit finding by virtual screening or compound design with quantitative structure-activity relationships. Here in we review widely used software for performing such tasks. Some techniques are based on relatively mature technology, shape-based similarity for instance. Typically, these methods remained in the realm of the expert user, the experienced modeler. However, advances in implementation and speed have improved usability and allow these methods to be applied to databases comprising millions of compounds. There are now many reports of such methods impacting drug-discovery projects. As such, the medicinal chemistry community has become the intended market for some of these new tools, yet they may consider the wide array and choice of approaches somewhat disconcerting. Each method has subtle differences and is better suited to certain tasks than others. In this article we review some of the widely used computational methods via application, provide straightforward background on the underlying theory and provide examples for the interested reader to pursue in more detail. In the new era of preclinical drug discovery there will be ever more pressure to move faster and more efficiently, and computational approaches based on 3D ligand similarity will play an increasing role in in this process.
Polygonal Shapes Detection in 3d Models of Complex Architectures
NASA Astrophysics Data System (ADS)
Benciolini, G. B.; Vitti, A.
2015-02-01
A sequential application of two global models defined on a variational framework is proposed for the detection of polygonal shapes in 3D models of complex architectures. As a first step, the procedure involves the use of the Mumford and Shah (1989) 1st-order variational model in dimension two (gridded height data are processed). In the Mumford-Shah model an auxiliary function detects the sharp changes, i.e., the discontinuities, of a piecewise smooth approximation of the data. The Mumford-Shah model requires the global minimization of a specific functional to simultaneously produce both the smooth approximation and its discontinuities. In the proposed procedure, the edges of the smooth approximation derived by a specific processing of the auxiliary function are then processed using the Blake and Zisserman (1987) 2nd-order variational model in dimension one (edges are processed in the plane). This second step permits to describe the edges of an object by means of piecewise almost-linear approximation of the input edges themselves and to detects sharp changes of the first-derivative of the edges so to detect corners. The Mumford-Shah variational model is used in two dimensions accepting the original data as primary input. The Blake-Zisserman variational model is used in one dimension for the refinement of the description of the edges. The selection among all the boundaries detected by the Mumford-Shah model of those that present a shape close to a polygon is performed by considering only those boundaries for which the Blake-Zisserman model identified discontinuities in their first derivative. The output of the procedure are hence shapes, coming from 3D geometric data, that can be considered as polygons. The application of the procedure is suitable for, but not limited to, the detection of objects such as foot-print of polygonal buildings, building facade boundaries or windows contours. v The procedure is applied to a height model of the building of the Engineering
Advanced prior modeling for 3D bright field electron tomography
NASA Astrophysics Data System (ADS)
Sreehari, Suhas; Venkatakrishnan, S. V.; Drummy, Lawrence F.; Simmons, Jeffrey P.; Bouman, Charles A.
2015-03-01
Many important imaging problems in material science involve reconstruction of images containing repetitive non-local structures. Model-based iterative reconstruction (MBIR) could in principle exploit such redundancies through the selection of a log prior probability term. However, in practice, determining such a log prior term that accounts for the similarity between distant structures in the image is quite challenging. Much progress has been made in the development of denoising algorithms like non-local means and BM3D, and these are known to successfully capture non-local redundancies in images. But the fact that these denoising operations are not explicitly formulated as cost functions makes it unclear as to how to incorporate them in the MBIR framework. In this paper, we formulate a solution to bright field electron tomography by augmenting the existing bright field MBIR method to incorporate any non-local denoising operator as a prior model. We accomplish this using a framework we call plug-and-play priors that decouples the log likelihood and the log prior probability terms in the MBIR cost function. We specifically use 3D non-local means (NLM) as the prior model in the plug-and-play framework, and showcase high quality tomographic reconstructions of a simulated aluminum spheres dataset, and two real datasets of aluminum spheres and ferritin structures. We observe that streak and smear artifacts are visibly suppressed, and that edges are preserved. Also, we report lower RMSE values compared to the conventional MBIR reconstruction using qGGMRF as the prior model.
NASA Astrophysics Data System (ADS)
Weiss, K.-P.; Bagrets, N.; Lange, C.; Goldacker, W.; Wohlgemuth, J.
2015-12-01
Insulating materials for use in cryogenic boundary conditions are still limited to a proved selection as Polyamid, Glasfiber reinforced resins, PEEK, Vespel etc. These materials are usually formed to parts by mechanical machining or sometimes by cast methods. Shaping complex geometries in one piece is limited. Innovative 3D printing is now an upcoming revolutionary technology to construct functional parts from a couple of thermoplastic materials as ABS, Nylon and others which possess quite good mechanical stability and allow realizing very complex shapes with very subtle details. Even a wide range of material mixtures is an option and thermal treatments can be used to finish the material structure for higher performance. The use of such materials in cryogenic environment is very attractive but so far poor experience exists. In this paper, first investigations of the thermal conductivity, expansion and mechanical strength are presented for a few selected commercial 3D material samples to evaluate their application prospects in the cryogenic temperature regime.
NASA Astrophysics Data System (ADS)
Kerschke, Dorit; Schilling, Maik; Simon, Andreas; Wächter, Joachim
2014-05-01
The Energiewende and the increasing scarcity of raw materials will lead to an intensified utilization of the subsurface in Germany. Within this context, geological 3D modeling is a fundamental approach for integrated decision and planning processes. Initiated by the development of the European Geospatial Infrastructure INSPIRE, the German State Geological Offices started digitizing their predominantly analog archive inventory. Until now, a comprehensive 3D subsurface model of Brandenburg did not exist. Therefore the project B3D strived to develop a new 3D model as well as a subsequent infrastructure node to integrate all geological and spatial data within the Geodaten-Infrastruktur Brandenburg (Geospatial Infrastructure, GDI-BB) and provide it to the public through an interactive 2D/3D web application. The functionality of the web application is based on a client-server architecture. Server-sided, all available spatial data is published through GeoServer. GeoServer is designed for interoperability and acts as the reference implementation of the Open Geospatial Consortium (OGC) Web Feature Service (WFS) standard that provides the interface that allows requests for geographical features. In addition, GeoServer implements, among others, the high performance certified compliant Web Map Service (WMS) that serves geo-referenced map images. For publishing 3D data, the OGC Web 3D Service (W3DS), a portrayal service for three-dimensional geo-data, is used. The W3DS displays elements representing the geometry, appearance, and behavior of geographic objects. On the client side, the web application is solely based on Free and Open Source Software and leans on the JavaScript API WebGL that allows the interactive rendering of 2D and 3D graphics by means of GPU accelerated usage of physics and image processing as part of the web page canvas without the use of plug-ins. WebGL is supported by most web browsers (e.g., Google Chrome, Mozilla Firefox, Safari, and Opera). The web
Faceless identification: a model for person identification using the 3D shape and 3D motion as cues
NASA Astrophysics Data System (ADS)
Klasen, Lena M.; Li, Haibo
1999-02-01
Person identification by using biometric methods based on image sequences, or still images, often requires a controllable and cooperative environment during the image capturing stage. In the forensic case the situation is more likely to be the opposite. In this work we propose a method that makes use of the anthropometry of the human body and human actions as cues for identification. Image sequences from surveillance systems are used, which can be seen as monocular image sequences. A 3D deformable wireframe body model is used as a platform to handle the non-rigid information of the 3D shape and 3D motion of the human body from the image sequence. A recursive method for estimating global motion and local shape variations is presented, using two recursive feedback systems.
The USGS 3D Seismic Velocity Model for Northern California
NASA Astrophysics Data System (ADS)
Brocher, T. M.; Aagaard, B.; Simpson, R. W.; Jachens, R. C.
2006-12-01
We present a new regional 3D seismic velocity model for Northern California for use in strong motion simulations of the 1906 San Francisco and other earthquakes. The model includes compressional-wave velocity (Vp), shear-wave velocity (Vs), density, and intrinsic attenuation (Qp, Qs). These properties were assigned for each rock type in a 3D geologic model derived from surface outcrops, boreholes, gravity and magnetic data, and seismic reflection, refraction, and tomography studies. A detailed description of the model, USGS Bay Area Velocity Model 05.1.0, is available online [http://www.sf06simulation.org/geology/velocitymodel]. For ground motion simulations Vs and Qs are more important parameters than Vp and Qp because the strongest ground motions are generated chiefly by shear and surface wave arrivals. Because Vp data are more common than Vs data, however, we first developed Vp versus depth relations for each rock type and then converted these to Vs versus depth relations. For the most important rock types in Northern California we compiled measurements of Vp versus depth using borehole logs, laboratory measurements on hand samples, seismic refraction profiles, and tomography models. These rock types include Salinian and Sierran granitic rocks, metagraywackes and greenstones of the Franciscan Complex, Tertiary and Mesozoic sedimentary and volcanic rocks, and Quaternary and Holocene deposits (Brocher, USGS OFR 05-1317, 2005). Vp versus depth curves were converted to Vs versus depth curves using new empirical nonlinear relations between Vs and Vp (Brocher, BSSA, 2005). These relations, showing that Poisson's ratio is a nonlinear function of Vp, were similarly based on compilations of diverse Vs and Vp measurements on a large suite of rock types, mainly from California and the Pacific Northwest. The model is distributed in a discretized form with routines to query the model using C++, C, and Fortran 77 programming languages. The geologic model was discretized at
A 3D Bubble Merger Model for RTI Mixing
NASA Astrophysics Data System (ADS)
Cheng, Baolian
2015-11-01
In this work we present a model for the merger processes of bubbles at the edge of an unstable acceleration driven mixing layer. Steady acceleration defines a self-similar mixing process, with a time-dependent inverse cascade of structures of increasing size. The time evolution is itself a renormalization group evolution. The model predicts the growth rate of a Rayleigh-Taylor chaotic fluid-mixing layer. The 3-D model differs from the 2-D merger model in several important ways. Beyond the extension of the model to three dimensions, the model contains one phenomenological parameter, the variance of the bubble radii at fixed time. The model also predicts several experimental numbers: the bubble mixing rate, the mean bubble radius, and the bubble height separation at the time of merger. From these we also obtain the bubble height to the radius aspect ratio, which is in good agreement with experiments. Applications to recent NIF and Omega experiments will be discussed. This work was performed under the auspices of the U.S. Department of Energy by the Los Alamos National Laboratory under Contract No. W-7405-ENG-36.
Quality assessment of watermarked 3D polygonal models
NASA Astrophysics Data System (ADS)
Funk, Wolfgang; Prasiswa, Jennifer
2006-02-01
In this paper, we present the design and results of subjective tests for evaluating the perceptibility of digital watermarks in 3D polygonal models. Based on the results we investigate different types of metrics with respect to their usefulness as predictors for the perceived visual quality of models that have been modified using a specific watermarking algorithm. We describe two experiments with models that have been watermarked using controlled free form deformations. The first experiment was conducted in supervised mode with still images of rendered models as stimuli and used the Two Alternative Forced Choice (2AFC) method. The second experiment was based on animated sequences and run in 2AFC mode with additional ratings of the perceived differences, but without assistance by the experimenter. We present a transparency analysis of the results and investigate the ability of image-based and geometry-based metrics to predict the perceived quality of the watermarked models. Our results show that the effectiveness of prediction depends on the type of model and in particular on the feature positions selected by the watermarking algorithm. The results of previous experiments with simplified polygonal models are confirmed, in that geometric measures are good predictors of quality ratings. We found that the symmetric Haussdorf distance is a promising candidate to evaluate the visual impact of the watermarking algorithm used in our experiments.
Handheld camera 3D modeling system using multiple reference panels
NASA Astrophysics Data System (ADS)
Fujimura, Kouta; Oue, Yasuhiro; Terauchi, Tomoya; Emi, Tetsuichi
2002-03-01
A novel 3D modeling system in which a target object is easily captured and modeled by using a hand-held camera with several reference panels is presented in this paper. The reference panels are designed to be able to obtain the camera position and discriminate between each other. A conventional 3D modeling system using a reference panel has several restrictions regarding the target object, specifically the size and its location. Our system uses multiple reference panels, which are set around the target object to remove these restrictions. The main features of this system are as follows: 1) The whole shape and photo-realistic textures of the target object can be digitized based on several still images or a movie captured by using a hand-held camera; as well as each location of the camera that can be calculated using the reference panels. 2) Our system can be provided as a software product only. That means there are no special requirements for hardware; even the reference panels , because they can be printed from image files or software. 3) This system can be applied to digitize a larger object. In the experiments, we developed and used an interactive region selection tool to detect the silhouette on each image instead of using the chroma -keying method. We have tested our system with a toy object. The calculation time is about 10 minutes (except for the capturing the images and extracting the silhouette by using our tool) on a personal computer with a Pentium-III processor (600MHz) and 320MB memory. However, it depends on how complex the images are and how many images you use. Our future plan is to evaluate the system with various kind of objects, specifically, large ones in outdoor environments.
3D model generation using an airborne swarm
NASA Astrophysics Data System (ADS)
Clark, R. A.; Punzo, G.; Dobie, G.; MacLeod, C. N.; Summan, R.; Pierce, G.; Macdonald, M.; Bolton, G.
2015-03-01
Using an artificial kinematic field to provide co-ordination between multiple inspection UAVs, the authors herein demonstrate full 3D modelling capability based on a photogrammetric system. The operation of the system is demonstrated by generating a full 3D surface model of an intermediate level nuclear waste storage drum. Such drums require periodic inspection to ensure that drum distortion or corrosion is carefully monitored. Performing this inspection with multiple airborne platforms enables rapid inspection of structures that are inaccessible to on-surface remote vehicles and are in human-hazardous environments. A three-dimensional surface-meshed model of the target can then be constructed in post-processing through photogrammetry analysis of the visual inspection data. The inspection environment uses a tracking system to precisely monitor the position of each aerial vehicle within the enclosure. The vehicles used are commercially available Parrot AR. Drone quadcopters, controlled through a computer interface connected over an IEEE 802.11n (WiFi) network, implementing a distributed controller for each vehicle. This enables the autonomous and distributed elements of the control scheme to be retained, while alleviating the vehicles of the control algorithm's computational load. The control scheme relies on a kinematic field defined with the target at its centre. This field defines the trajectory for all the drones in the volume relative to the central target, enabling the drones to circle the target at a set radius while avoiding drone collisions. This function enables complete coverage along the height of the object, which is assured by transitioning to another inspection band only after completing circumferential coverage. Using a swarm of vehicles, the time until complete coverage can be significantly reduced.
3D model generation using an airborne swarm
Clark, R. A.; Punzo, G.; Macdonald, M.; Dobie, G.; MacLeod, C. N.; Summan, R.; Pierce, G.; Bolton, G.
2015-03-31
Using an artificial kinematic field to provide co-ordination between multiple inspection UAVs, the authors herein demonstrate full 3D modelling capability based on a photogrammetric system. The operation of the system is demonstrated by generating a full 3D surface model of an intermediate level nuclear waste storage drum. Such drums require periodic inspection to ensure that drum distortion or corrosion is carefully monitored. Performing this inspection with multiple airborne platforms enables rapid inspection of structures that are inaccessible to on-surface remote vehicles and are in human-hazardous environments. A three-dimensional surface-meshed model of the target can then be constructed in post-processing through photogrammetry analysis of the visual inspection data. The inspection environment uses a tracking system to precisely monitor the position of each aerial vehicle within the enclosure. The vehicles used are commercially available Parrot AR. Drone quadcopters, controlled through a computer interface connected over an IEEE 802.11n (WiFi) network, implementing a distributed controller for each vehicle. This enables the autonomous and distributed elements of the control scheme to be retained, while alleviating the vehicles of the control algorithm’s computational load. The control scheme relies on a kinematic field defined with the target at its centre. This field defines the trajectory for all the drones in the volume relative to the central target, enabling the drones to circle the target at a set radius while avoiding drone collisions. This function enables complete coverage along the height of the object, which is assured by transitioning to another inspection band only after completing circumferential coverage. Using a swarm of vehicles, the time until complete coverage can be significantly reduced.
NASA Astrophysics Data System (ADS)
Balčiūnas, Evaldas; Lukoševičius, Laurynas; Mackevičiūtė, Dovilė; Rekštytė, Sima; Rutkūnas, Vygandas; Paipulas, Domas; Stankevičiūtė, Karolina; Baltriukienė, Daiva; Bukelskienė, Virginija; Piskarskas, Algis P.; Malinauskas, Mangirdas
2014-03-01
We present a novel approach to manufacturing 3D microstructured composite scaffolds for tissue engineering applications. A thermal extrusion 3D printer - a simple, low-cost tabletop device enabling rapid materialization of CAD models in plastics - was used to produce cm-scale microporous scaffolds out of polylactic acid (PLA). The fabricated objects were subsequently immersed in a photosensitive monomer solution and direct laser writing technique (DLW) was used to refine its inner structure by fabricating a fine mesh inside the previously produced scaffold. In addition, a composite material structure out of four different materials fabricated via DLW is presented. This technique, empowered by ultrafast lasers allows 3D structuring with high spatial resolution in a great variety of photosensitive materials. A composite scaffold made of distinct materials and periodicities is acquired after the development process used to wash out non-linked monomers. Another way to modify the 3D printed PLA surfaces was also demonstrated - ablation with femtosecond laser beam. Structure geometry on macro- to micro- scales could be finely tuned by combining these fabrication techniques. Such artificial 3D substrates could be used for cell growth or as biocompatible-biodegradable implants. To our best knowledge, this is the first experimental demonstration showing the creation of composite 3D scaffolds using convenient 3D printing combined with DLW. This combination of distinct material processing techniques enables rapid fabrication of diverse functional micro-featured and integrated devices. Hopefully, the proposed approach will find numerous applications in the field of tissue engineering, as well as in microelectromechanical systems, microfluidics, microoptics and others.
Crashworthiness analysis using advanced material models in DYNA3D
Logan, R.W.; Burger, M.J.; McMichael, L.D.; Parkinson, R.D.
1993-10-22
As part of an electric vehicle consortium, LLNL and Kaiser Aluminum are conducting experimental and numerical studies on crashworthy aluminum spaceframe designs. They have jointly explored the effect of heat treat on crush behavior and duplicated the experimental behavior with finite-element simulations. The major technical contributions to the state of the art in numerical simulation arise from the development and use of advanced material model descriptions for LLNL`s DYNA3D code. Constitutive model enhancements in both flow and failure have been employed for conventional materials such as low-carbon steels, and also for lighter weight materials such as aluminum and fiber composites being considered for future vehicles. The constitutive model enhancements are developed as extensions from LLNL`s work in anisotropic flow and multiaxial failure modeling. Analysis quality as a function of level of simplification of material behavior and mesh is explored, as well as the penalty in computation cost that must be paid for using more complex models and meshes. The lightweight material modeling technology is being used at the vehicle component level to explore the safety implications of small neighborhood electric vehicles manufactured almost exclusively from these materials.
Energy flow in passive and active 3D cochlear model
Wang, Yanli; Steele, Charles; Puria, Sunil
2015-12-31
Energy flow in the cochlea is an important characteristic of the cochlear traveling wave, and many investigators, such as von Békésy and Lighthill, have discussed this phenomenon. Particularly after the discovery of the motility of the outer hair cells (OHCs), the nature of the power gain of the cochlea has been a fundamental research question. In the present work, direct three-dimensional (3D) calculations of the power on cross sections of the cochlea and on the basilar membrane are performed based on a box model of the mouse cochlea. The distributions of the fluid pressure and fluid velocity in the scala vestibuli are presented. The power output from the OHCs and the power loss due to fluid viscous damping are calculated along the length of the cochlea. This work provides a basis for theoretical calculations of the power gain of the OHCs from mechanical considerations.
Energy flow in passive and active 3D cochlear model
NASA Astrophysics Data System (ADS)
Wang, Yanli; Puria, Sunil; Steele, Charles
2015-12-01
Energy flow in the cochlea is an important characteristic of the cochlear traveling wave, and many investigators, such as von Békésy and Lighthill, have discussed this phenomenon. Particularly after the discovery of the motility of the outer hair cells (OHCs), the nature of the power gain of the cochlea has been a fundamental research question. In the present work, direct three-dimensional (3D) calculations of the power on cross sections of the cochlea and on the basilar membrane are performed based on a box model of the mouse cochlea. The distributions of the fluid pressure and fluid velocity in the scala vestibuli are presented. The power output from the OHCs and the power loss due to fluid viscous damping are calculated along the length of the cochlea. This work provides a basis for theoretical calculations of the power gain of the OHCs from mechanical considerations.
Appearance-based color face recognition with 3D model
NASA Astrophysics Data System (ADS)
Wang, Chengzhang; Bai, Xiaoming
2013-03-01
Appearance-based face recognition approaches explore color cues of face images, i.e. grey or color information for recognition task. They first encode color face images, and then extract facial features for classification. Similar to conventional singular value decomposition, hypercomplex matrix also exists singular value decomposition on hypercomplex field. In this paper, a novel color face recognition approach based on hypercomplex singular value decomposition is proposed. The approach employs hypercomplex to encode color face information of different channels simultaneously. Hypercomplex singular value decomposition is utilized then to compute the basis vectors of the color face subspace. To improve learning efficiency of the algorithm, 3D active deformable model is exploited to generate virtual face images. Color face samples are projected onto the subspace and projection coefficients are utilized as facial features. Experimental results on CMU PIE face database verify the effectiveness of the proposed approach.
3D Model of the San Emidio Geothermal Area
James E. Faulds
2013-12-31
The San Emidio geothermal system is characterized by a left-step in a west-dipping normal fault system that bounds the western side of the Lake Range. The 3D geologic model consists of 5 geologic units and 55 faults. Overlying Jurrassic-Triassic metasedimentary basement is a ~500 m-1000 m thick section of the Miocene lower Pyramid sequence, pre- syn-extensional Quaternary sedimentary rocks and post-extensional Quaternary rocks. 15-30º eastward dip of the stratigraphy is controlled by the predominant west-dipping fault set. Both geothermal production and injection are concentrated north of the step over in an area of closely spaced west dipping normal faults.
3D Model of the Neal Hot Springs Geothermal Area
Faulds, James E.
2013-12-31
The Neal Hot Springs geothermal system lies in a left-step in a north-striking, west-dipping normal fault system, consisting of the Neal Fault to the south and the Sugarloaf Butte Fault to the north (Edwards, 2013). The Neal Hot Springs 3D geologic model consists of 104 faults and 13 stratigraphic units. The stratigraphy is sub-horizontal to dipping <10 degrees and there is no predominant dip-direction. Geothermal production is exclusively from the Neal Fault south of, and within the step-over, while geothermal injection is into both the Neal Fault to the south of the step-over and faults within the step-over.
3D model atmospheres and the solar photospheric oxygen abundance
NASA Astrophysics Data System (ADS)
Caffau, E.; Ludwig, H.-G.
2008-10-01
In recent years the photospheric solar oxygen abundance experienced a significant downward revision. However, a low photospheric abundance is incompatible with the value in the solar interior inferred from helioseismology. For contributing to the dispute whether the solar oxygen abundance is “high” or “low”, we re-derived its photospheric abundance independently of previous analyses. We applied 3D (CO5BOLD) as well as 1D model atmospheres. We considered standard disc-centre and disc-integrated spectral atlases, as well as newly acquired solar intensity spectra at different heliocentric angles. We determined the oxygen abundances from equivalent width and/or line profile fitting of a number of atomic lines. As preliminary result, we find an oxygen abundance in the range 8.73 8.79, encompassing the value obtained by Holweger (2001), and somewhat higher than the value obtained by Asplund et al. (2005).
NASA Technical Reports Server (NTRS)
Wilson, Brad; Galatzer, Yishai
2008-01-01
The Space Shuttle is protected by a Thermal Protection System (TPS) made of tens of thousands of individually shaped heat protection tile. With every flight, tiles are damaged on take-off and return to earth. After each mission, the heat tiles must be fixed or replaced depending on the level of damage. As part of the return to flight mission, the TPS requirements are more stringent, leading to a significant increase in heat tile replacements. The replacement operation requires scanning tile cavities, and in some cases the actual tiles. The 3D scan data is used to reverse engineer each tile into a precise CAD model, which in turn, is exported to a CAM system for the manufacture of the heat protection tile. Scanning is performed while other activities are going on in the shuttle processing facility. Many technicians work simultaneously on the space shuttle structure, which results in structural movements and vibrations. This paper will cover a portable, ultra-fast data acquisition approach used to scan surfaces in this unstable environment.
Towards Automatic Semantic Labelling of 3D City Models
NASA Astrophysics Data System (ADS)
Rook, M.; Biljecki, F.; Diakité, A. A.
2016-10-01
The lack of semantic information in many 3D city models is a considerable limiting factor in their use, as a lot of applications rely on semantics. Such information is not always available, since it is not collected at all times, it might be lost due to data transformation, or its lack may be caused by non-interoperability in data integration from other sources. This research is a first step in creating an automatic workflow that semantically labels plain 3D city model represented by a soup of polygons, with semantic and thematic information, as defined in the CityGML standard. The first step involves the reconstruction of the topology, which is used in a region growing algorithm that clusters upward facing adjacent triangles. Heuristic rules, embedded in a decision tree, are used to compute a likeliness score for these regions that either represent the ground (terrain) or a RoofSurface. Regions with a high likeliness score, to one of the two classes, are used to create a decision space, which is used in a support vector machine (SVM). Next, topological relations are utilised to select seeds that function as a start in a region growing algorithm, to create regions of triangles of other semantic classes. The topological relationships of the regions are used in the aggregation of the thematic building features. Finally, the level of detail is detected to generate the correct output in CityGML. The results show an accuracy between 85 % and 99 % in the automatic semantic labelling on four different test datasets. The paper is concluded by indicating problems and difficulties implying the next steps in the research.
3D Model of the Tuscarora Geothermal Area
Faulds, James E.
2013-12-31
The Tuscarora geothermal system sits within a ~15 km wide left-step in a major west-dipping range-bounding normal fault system. The step over is defined by the Independence Mountains fault zone and the Bull Runs Mountains fault zone which overlap along strike. Strain is transferred between these major fault segments via and array of northerly striking normal faults with offsets of 10s to 100s of meters and strike lengths of less than 5 km. These faults within the step over are one to two orders of magnitude smaller than the range-bounding fault zones between which they reside. Faults within the broad step define an anticlinal accommodation zone wherein east-dipping faults mainly occupy western half of the accommodation zone and west-dipping faults lie in the eastern half of the accommodation zone. The 3D model of Tuscarora encompasses 70 small-offset normal faults that define the accommodation zone and a portion of the Independence Mountains fault zone, which dips beneath the geothermal field. The geothermal system resides in the axial part of the accommodation, straddling the two fault dip domains. The Tuscarora 3D geologic model consists of 10 stratigraphic units. Unconsolidated Quaternary alluvium has eroded down into bedrock units, the youngest and stratigraphically highest bedrock units are middle Miocene rhyolite and dacite flows regionally correlated with the Jarbidge Rhyolite and modeled with uniform cumulative thickness of ~350 m. Underlying these lava flows are Eocene volcanic rocks of the Big Cottonwood Canyon caldera. These units are modeled as intracaldera deposits, including domes, flows, and thick ash deposits that change in thickness and locally pinch out. The Paleozoic basement of consists metasedimenary and metavolcanic rocks, dominated by argillite, siltstone, limestone, quartzite, and metabasalt of the Schoonover and Snow Canyon Formations. Paleozoic formations are lumped in a single basement unit in the model. Fault blocks in the eastern
A new 3D dynamical biomechanical tongue model
NASA Astrophysics Data System (ADS)
Gerard, Jean-Michel; Perrier, Pascal; Payan, Yohan; Wilhelms-Tricarico, Reiner
2004-05-01
A new dynamical biomechanical tongue model is being developed to study speech motor control. In spite of its computational complexity, a 3D representation was chosen in order to account for various contacts between tongue and external structures such as teeth, palate, and vocal tract walls. A fair representation of tongue muscle anatomy is provided, by designing the finite element mesh from the visible human data set (female subject). Model geometry was then matched to a human speaker, so that simulations can be quantitatively compared to experimental MRI data. A set of 11 muscles is modeled, whose role in speech gestures is well established. Each muscle is defined by a set of elements whose elastic properties change with muscle activation. Muscles forces are applied to the tongue model via macrofibers defined within the mesh by muscle specific sets of nodes. These forces are currently specified as step functions. Boundary conditions are set using zero-displacement nodes simulating attachments of tongue on bony structures. The nonlinear mechanical properties of tongue soft tissues are modeled using a hyperelastic material. Three-dimensional tongue deformations generated by each muscle, using FEM software ANSYS for computation, will be presented. Implications for speech motor control will be proposed.
A new 3D dynamical biomechanical tongue model
NASA Astrophysics Data System (ADS)
Gerard, Jean-Michel; Perrier, Pascal; Payan, Yohan; Wilhelms-Tricarico, Reiner
2001-05-01
A new dynamical biomechanical tongue model is being developed to study speech motor control. In spite of its computational complexity, a 3D representation was chosen in order to account for various contacts between tongue and external structures such as teeth, palate, and vocal tract walls. A fair representation of tongue muscle anatomy is provided, by designing the finite element mesh from the visible human data set (female subject). Model geometry was then matched to a human speaker, so that simulations can be quantitatively compared to experimental MRI data. A set of 11 muscles is modeled, whose role in speech gestures is well established. Each muscle is defined by a set of elements whose elastic properties change with muscle activation. Muscles forces are applied to the tongue model via macrofibers defined within the mesh by muscle specific sets of nodes. These forces are currently specified as step functions. Boundary conditions are set using zero-displacement nodes simulating attachments of tongue on bony structures. The nonlinear mechanical properties of tongue soft tissues are modeled using a hyperelastic material. Three-dimensional tongue deformations generated by each muscle, using FEM software ANSYS for computation, will be presented. Implications for speech motor control will be proposed.
3D Printed Molecules and Extended Solid Models for Teaching Symmetry and Point Groups
ERIC Educational Resources Information Center
Scalfani, Vincent F.; Vaid, Thomas P.
2014-01-01
Tangible models help students and researchers visualize chemical structures in three dimensions (3D). 3D printing offers a unique and straightforward approach to fabricate plastic 3D models of molecules and extended solids. In this article, we prepared a series of digital 3D design files of molecular structures that will be useful for teaching…
Towards more realistic 2D & 3D numerical models of Earth's mantle
NASA Astrophysics Data System (ADS)
Ghias, Sanaz
2011-12-01
There are a number of simplifying assumptions in modeling Earth's deep interior. These are mostly simplifying assumptions that make the mathematics simpler either for less complicated modeling or for numerical efficiency purposes. The aim of this study is to investigate the effects of some of these simplifying assumptions on 2D and 3D mantle convection models. In particular, the cases with variable coefficients of thermal expansion, alpha, and the inclusion of mineral phase transitions and viscosity stratification have been studied. The coefficient of thermal expansion is temperature- and depth-dependent in Earth. But for simplicity, it has been considered as constant in most mantle convection models and only depth-dependent in others. 2D mantle convection models (2D Cartesian and 2D cylindrical) have been created based on an existing model from Jarvis [1992] to investigate the effects of temperature- and depth-dependent alpha on mantle convection compared with the simplified cases. Also an existing version of a 3D parallel mantle convection model, MC3D, from Lowman et al. [2001] have been modified to include the temperature- and depth-dependent alpha. In the 3D study it has also been investigated that how the effects of temperature- and depth-dependent alpha vary with or without lithospheric plates. There are at least two mineral phase transitions in Earth. There is an exothermic phase boundary at 410km below the surface and an endothermic phase boundary at 660km below the surface. For simplicity, most mantle convection models do not consider any of the phase boundaries. Some consider only the endothermic phase boundary. A 2D cylindrical model from Shahnas and Jarvas [2005] has been employed to investigate the effects of considering both phase boundaries compared to models with either no, or one, phase boundary. Different viscosity stratifications have been used in addition to the phase boundaries.
ALE3D Model Predictions and Experimental Analysis of the Cookoff Response of Comp B*
Maienschein, J L; McClelland, M A; Wardell, J F; Reaugh, J E; Nichols, A L; Tran, T D
2003-11-24
ALE3D simulations are presented for the thermal explosion of Comp B (RDX,TNT) in a Scaled Thermal Explosion Experiment (STEX). Candidate models and numerical strategies are being tested using the ALE3D code which simulates the coupled thermal, mechanical, and chemical behavior during heating, ignition, and explosion. The mechanical behavior of the solid constituents is represented by a Steinberg-Guinan model while polynomial and gamma-law expressions are used for the equation of state of the solid and gas species, respectively. A gamma-law model is employed for the air in gaps, and a mixed material model is used for the interface between air and explosive. A three-step chemical kinetics model is used for each of the RDX and TNT reaction sequences during the heating and ignition phases, and a pressure-dependent deflagration model is employed during the rapid expansion. Parameters for the three-step kinetics model are specified using measurements of the One-Dimensional-Time-to-Explosion (ODTX), while measurements for burn rate are employed to determine parameters in the burn front model. We compare model predictions to measurements for temperature fields, ignition temperature, and tube wall strain during the heating, ignition, and explosive phases.
A multipurpose 3-D grid of stellar models
NASA Astrophysics Data System (ADS)
Maíz Apellániz, J.
2013-05-01
The last two decades have produced a proliferation of stellar atmosphere grids, evolutionary tracks, and isochrones which are available to the astronomical community from different internet services. However, it is not straightforward (at least for an inexperienced user) to manipulate those models to answer questions of the type: What is the spectral energy distribution of a 9000 K giant? What about its J-band magnitude for different metallicities? What can I tell about the mass of a star if I know that its unreddened B-V color is -0.05 and its luminosity in solar units is 10^5? The answers to those questions are indeed in the models but a series of transformations and combinations involving different variables and models are required to obtain them. To make the available knowledge more user friendly, I have combined a number of state-of-the-art sources to create a 3-D (effective temperature, luminosity, and metallicity) grid of stellar models for which I provide calibrated SEDs and magnitudes as well as auxiliary variables such as mass and age. Furthermore, I have generated a grid of extinguished magnitudes using the recent Maíz Apellániz et al. (2012) extinction laws and incorporated them into the Bayesian code CHORIZOS (Maíz Apellániz 2004).
3-D GRACE gravity model for the 2011 Japan earthquake
NASA Astrophysics Data System (ADS)
Sastry, Rambhatla G.; Sonker, Mahendra K.
2017-02-01
The GRACE mission has contributed to the seismic characterization of major earthquakes in offshore regions of the world. Here, we isolate satellite gravity signal (μGal range) for the Japan Earthquake of 2011 using a difference method. Contrary to the existing gravity models, we propose a unit vertical pyramid based five-layer 3-D thrust fault model, which extends to the hypocenter and honors the ocean water layer and sea floor upheaval also. Our model partly uses existing seismological information (hypocenter depth of 32 km, rupture length of 300 km and vertical slip of 4 m), provides a snapshot of episodic subduction of the Pacific Plate below the Atlantic Plate and its gravity response closely matches the observed gravity (RMS error of 3.4012×10-13μGal), fully accounting for co-seismic mass redistribution including sea surface deformation. Our inferred rupture length, rupture velocity, average seismic moment magnitude and momentum, respectively, are 300 km, 4.49 km/s, 1.152×1021-1.8816×1021 N m and 2.319×106 GNs, which fairly agree with the literature. Further, our model inferred momentum at the sea floor corresponds to an area pulse that led to Tsunami generation.
Automatic paper sliceform design from 3D solid models.
Le-Nguyen, Tuong-Vu; Low, Kok-Lim; Ruiz, Conrado; Le, Sang N
2013-11-01
A paper sliceform or lattice-style pop-up is a form of papercraft that uses two sets of parallel paper patches slotted together to make a foldable structure. The structure can be folded flat, as well as fully opened (popped-up) to make the two sets of patches orthogonal to each other. Automatic design of paper sliceforms is still not supported by existing computational models and remains a challenge. We propose novel geometric formulations of valid paper sliceform designs that consider the stability, flat-foldability and physical realizability of the designs. Based on a set of sufficient construction conditions, we also present an automatic algorithm for generating valid sliceform designs that closely depict the given 3D solid models. By approximating the input models using a set of generalized cylinders, our method significantly reduces the search space for stable and flat-foldable sliceforms. To ensure the physical realizability of the designs, the algorithm automatically generates slots or slits on the patches such that no two cycles embedded in two different patches are interlocking each other. This guarantees local pairwise assembility between patches, which is empirically shown to lead to global assembility. Our method has been demonstrated on a number of example models, and the output designs have been successfully made into real paper sliceforms.
3D numerical modeling of India-Asia-like collision
NASA Astrophysics Data System (ADS)
-Erika Püsök, Adina; Kaus, Boris; Popov, Anton
2013-04-01
above a strong mantle lithosphere - the jelly sandwich model (Burov and Watts, 2006). 3D models are thus needed to investigate these hypotheses. However, fully 3D models of the dynamics of continent collision zones have only been developed very recently, and presently most research groups have relied on certain explicit assumptions for their codes. Here, we employ the parallel 3D code LaMEM (Lithosphere and Mantle Evolution Model), with a finite difference staggered grid solver, which is capable of simulating lithospheric deformation while simultaneously taking mantle flow and a free surface into account. We here report on first lithospheric and upper-mantle scale simulations in which the Indian lithosphere is indented into Asia. Acknowledgements. Funding was provided by the European Research Council under the European Community's Seventh Framework Program (FP7/2007-2013) / ERC Grant agreement #258830. Numerical computations have been performed on JUQUEEN of the Jülich high-performance computing center. • Beaumont, C., Jamieson, R.A., Nguyen, M.H., Medvedev, S.E., 2004. Crustal channel flows: 1. Numerical models with applications to the tectonics of the Himalayan-Tibetan orogeny. J. Geophys. Res. 109, B06406. • Burov, E. & Watts, W.S., 2006. The long-term strength of continental lithosphere: "jelly sandwich" or "crème brûlée"?. GSA Today, 16, doi: 10.1130/1052-5173(2006)1016<1134:TLTSOC>1132.1130.CO;1132. • England P., Houseman, G., 1986. Finite strain calculations of continental deformation. 2. Comparison with the India-Asia collision zone. J. Geophys. Res.- Solid Earth and Planets 91 (B3), 3664-3676. • Jackson, J., 2002. Strength of the continental lithosphere: time to abandon the jelly sandwich?. GSA Today, September, 4-10. • Lechmann, S.M., May, D.A., Kaus, B.J.P., Schmalholz, S.M., 2011. Comparing thin-sheet models with 3D multilayer models for continental collision. Geophy. Int. J. doi: 10.1111/j.1365-246X.2011.05164.x • Royden, L.H., Burchfiel, B
3D Printing of Molecular Potential Energy Surface Models
ERIC Educational Resources Information Center
Lolur, Phalgun; Dawes, Richard
2014-01-01
Additive manufacturing, commonly known as 3D printing, is gaining popularity in a variety of applications and has recently become routinely available. Today, 3D printing services are not only found in engineering design labs and through online companies, but also in university libraries offering student access. In addition, affordable options for…
NASA Astrophysics Data System (ADS)
Naghshine, Babak. B.; Kiani, Amirkianoosh
2017-02-01
Laser processing is one of the most popular small-scale patterning methods and has many applications in semiconductor device fabrication and biomedical engineering. Numerical modelling of this process can be used for better understanding of the process, optimization, and predicting the quality of the final product. An accurate 3D model is presented here for short laser pulses that can predict the ablation depth and temperature distribution on any section of the material in a minimal amount of time. In this transient model, variations of thermal properties, plasma shielding, and phase change are considered. Ablation depth was measured using a 3D optical profiler. Calculated depths are in good agreement with measured values on laser treated titanium surfaces. The proposed model can be applied to a wide range of materials and laser systems.
3D-Digital soil property mapping by geoadditive models
NASA Astrophysics Data System (ADS)
Papritz, Andreas
2016-04-01
In many digital soil mapping (DSM) applications, soil properties must be predicted not only for a single but for multiple soil depth intervals. In the GlobalSoilMap project, as an example, predictions are computed for the 0-5 cm, 5-15 cm, 15-30 cm, 30-60 cm, 60-100 cm, 100-200 cm depth intervals (Arrouays et al., 2014). Legacy soil data are often used for DSM. It is common for such datasets that soil properties were measured for soil horizons or for layers at varying soil depth and with non-constant thickness (support). This poses problems for DSM: One strategy is to harmonize the soil data to common depth prior to the analyses (e.g. Bishop et al., 1999) and conduct the statistical analyses for each depth interval independently. The disadvantage of this approach is that the predictions for different depths are computed independently from each other so that the predicted depth profiles may be unrealistic. Furthermore, the error induced by the harmonization to common depth is ignored in this approach (Orton et al. 2016). A better strategy is therefore to process all soil data jointly without prior harmonization by a 3D-analysis that takes soil depth and geographical position explicitly into account. Usually, the non-constant support of the data is then ignored, but Orton et al. (2016) presented recently a geostatistical approach that accounts for non-constant support of soil data and relies on restricted maximum likelihood estimation (REML) of a linear geostatistical model with a separable, heteroscedastic, zonal anisotropic auto-covariance function and area-to-point kriging (Kyriakidis, 2004.) Although this model is theoretically coherent and elegant, estimating its many parameters by REML and selecting covariates for the spatial mean function is a formidable task. A simpler approach might be to use geoadditive models (Kammann and Wand, 2003; Wand, 2003) for 3D-analyses of soil data. geoAM extend the scope of the linear model with spatially correlated errors to
3D Finite Difference Modelling of Basaltic Region
NASA Astrophysics Data System (ADS)
Engell-Sørensen, L.
2003-04-01
The main purpose of the work was to generate realistic data to be applied for testing of processing and migration tools for basaltic regions. The project is based on the three - dimensional finite difference code (FD), TIGER, made by Sintef. The FD code was optimized (parallelized) by the author, to run on parallel computers. The parallel code enables us to model large-scale realistic geological models and to apply traditional seismic and micro seismic sources. The parallel code uses multiple processors in order to manipulate subsets of large amounts of data simultaneously. The general anisotropic code uses 21 elastic coefficients. Eight independent coefficients are needed as input parameters for the general TI medium. In the FD code, the elastic wave field computation is implemented by a higher order FD solution to the elastic wave equation and the wave fields are computed on a staggered grid, shifted half a node in one or two directions. The geological model is a gridded basalt model, which covers from 24 km to 37 km of a real shot line in horizontal direction and from the water surface to the depth of 3.5 km. The 2frac {1}{2}D model has been constructed using the compound modeling software from Norsk Hydro. The vertical parameter distribution is obtained from observations in two wells. At The depth of between 1100 m to 1500 m, a basalt horizon covers the whole sub surface layers. We have shown that it is possible to simulate a line survey in realistic (3D) geological models in reasonable time by using high performance computers. The author would like to thank Norsk Hydro, Statoil, GEUS, and SINTEF for very helpful discussions and Parallab for being helpful with the new IBM, p690 Regatta system.
Predicted 3D Model of the Rabies Virus Glycoprotein Trimer.
Fernando, Bastida-González; Yersin, Celaya-Trejo; José, Correa-Basurto; Paola, Zárate-Segura
2016-01-01
The RABVG ectodomain is a homotrimer, and trimers are often called spikes. They are responsible for the attachment of the virus through the interaction with nicotinic acetylcholine receptors, neural cell adhesion molecule (NCAM), and the p75 neurotrophin receptor (p75NTR). This makes them relevant in viral pathogenesis. The antigenic structure differs significantly between the trimers and monomers. Surfaces rich in hydrophobic amino acids are important for trimer stabilization in which the C-terminal of the ectodomain plays an important role; to understand these interactions between the G proteins, a mechanistic study of their functions was performed with a molecular model of G protein in its trimeric form. This verified its 3D conformation. The molecular modeling of G protein was performed by a I-TASSER server and was evaluated via a Rachamandran plot and ERRAT program obtained 84.64% and 89.9% of the residues in the favorable regions and overall quality factor, respectively. The molecular dynamics simulations were carried out on RABVG trimer at 310 K. From these theoretical studies, we retrieved the RMSD values from Cα atoms to assess stability. Preliminary model of G protein of rabies virus stable at 12 ns with molecular dynamics was obtained.
3D finite element modeling of sliding wear
NASA Astrophysics Data System (ADS)
Buentello Hernandez, Rodolfo G.
Wear is defined as "the removal of material volume through some mechanical process between two surfaces". There are many mechanical situations that can induce wear and each can involve many wear mechanisms. This research focuses on the mechanical wear due to dry sliding between two surfaces. Currently there is a need to identify and compare materials that would endure sliding wear under severe conditions such as high velocities. The high costs associated with the field experimentation of systems subject to high-speed sliding, has prevented the collection of the necessary data required to fully characterize this phenomena. Simulating wear through Finite Elements (FE) would enable its prediction under different scenarios and would reduce experimentation costs. In the aerospace, automotive and weapon industries such a model can aid in material selection, design and/or testing of systems subjected to wear in bearings, gears, brakes, gun barrels, slippers, locomotive wheels, or even rocket test tracks. The 3D wear model presented in this dissertation allows one to reasonably predict high-speed sliding mechanical wear between two materials. The model predictions are reasonable, when compared against those measured on a sled slipper traveling over the Holloman High Speed Tests Track. This slipper traveled a distance of 5,816 meters in 8.14 seconds and reached a maximum velocity of 1,530 m/s.
Predicted 3D Model of the Rabies Virus Glycoprotein Trimer
Fernando, Bastida-González; Yersin, Celaya-Trejo; José, Correa-Basurto; Paola, Zárate-Segura
2016-01-01
The RABVG ectodomain is a homotrimer, and trimers are often called spikes. They are responsible for the attachment of the virus through the interaction with nicotinic acetylcholine receptors, neural cell adhesion molecule (NCAM), and the p75 neurotrophin receptor (p75NTR). This makes them relevant in viral pathogenesis. The antigenic structure differs significantly between the trimers and monomers. Surfaces rich in hydrophobic amino acids are important for trimer stabilization in which the C-terminal of the ectodomain plays an important role; to understand these interactions between the G proteins, a mechanistic study of their functions was performed with a molecular model of G protein in its trimeric form. This verified its 3D conformation. The molecular modeling of G protein was performed by a I-TASSER server and was evaluated via a Rachamandran plot and ERRAT program obtained 84.64% and 89.9% of the residues in the favorable regions and overall quality factor, respectively. The molecular dynamics simulations were carried out on RABVG trimer at 310 K. From these theoretical studies, we retrieved the RMSD values from Cα atoms to assess stability. Preliminary model of G protein of rabies virus stable at 12 ns with molecular dynamics was obtained. PMID:27294109
NASA Astrophysics Data System (ADS)
Gallagher, A. J.; Caffau, E.; Bonifacio, P.; Ludwig, H.-G.; Steffen, M.; Homeier, D.; Plez, B.
2017-02-01
Context. Tighter constraints on metal-poor stars we observe are needed to better understand the chemical processes of the early Universe. Computing a stellar spectrum in 3D allows one to model complex stellar behaviours, which cannot be replicated in 1D. Aims: We examine the effect that the intrinsic CNO abundances have on a 3D model structure and the resulting 3D spectrum synthesis. Methods: Model atmospheres were computed in 3D for three distinct CNO chemical compositions using the CO5BOLD model atmosphere code, and their internal structures were examined. Synthetic spectra were computed from these models using Linfor3D and they were compared. New 3D abundance corrections for the G-band and a selection of UV OH lines were also computed. Results: The varying CNO abundances change the metal content of the 3D models. This had an effect on the model structure and the resulting synthesis. However, it was found that the C/O ratio had a larger effect than the overall metal content of a model. Conclusions: Our results suggest that varying the C/O ratio has a substantial impact on the internal structure of the 3D model, even in the hot turn-off star models explored here. This suggests that bespoke 3D models, for specific CNO abundances should be sought. Such effects are not seen in 1D at these temperature regimes.
Jain, Prashant K; Freels, James D; Cook, David Howard
2012-08-01
Three dimensional simulation capabilities are currently being developed at Oak Ridge National Laboratory using COMSOL Multiphysics, a finite element modeling software, to investigate thermal expansion of High Flux Isotope Reactor (HFIR) s low enriched uranium fuel plates. To validate simulations, 3D models have also been developed for the experimental setup used by Cheverton and Kelley in 1968 to investigate the buckling and thermal deflections of HFIR s highly enriched uranium fuel plates. Results for several simulations are presented in this report, and comparisons with the experimental data are provided when data are available. A close agreement between the simulation results and experimental findings demonstrates that the COMSOL simulations are able to capture the thermal expansion physics accurately and that COMSOL could be deployed as a predictive tool for more advanced computations at realistic HFIR conditions to study temperature-induced fuel plate deflection behavior.
Detailed 3D representations for object recognition and modeling.
Zia, M Zeeshan; Stark, Michael; Schiele, Bernt; Schindler, Konrad
2013-11-01
Geometric 3D reasoning at the level of objects has received renewed attention recently in the context of visual scene understanding. The level of geometric detail, however, is typically limited to qualitative representations or coarse boxes. This is linked to the fact that today's object class detectors are tuned toward robust 2D matching rather than accurate 3D geometry, encouraged by bounding-box-based benchmarks such as Pascal VOC. In this paper, we revisit ideas from the early days of computer vision, namely, detailed, 3D geometric object class representations for recognition. These representations can recover geometrically far more accurate object hypotheses than just bounding boxes, including continuous estimates of object pose and 3D wireframes with relative 3D positions of object parts. In combination with robust techniques for shape description and inference, we outperform state-of-the-art results in monocular 3D pose estimation. In a series of experiments, we analyze our approach in detail and demonstrate novel applications enabled by such an object class representation, such as fine-grained categorization of cars and bicycles, according to their 3D geometry, and ultrawide baseline matching.
3D electro-thermal Monte Carlo study of transport in confined silicon devices
NASA Astrophysics Data System (ADS)
Mohamed, Mohamed Y.
The simultaneous explosion of portable microelectronics devices and the rapid shrinking of microprocessor size have provided a tremendous motivation to scientists and engineers to continue the down-scaling of these devices. For several decades, innovations have allowed components such as transistors to be physically reduced in size, allowing the famous Moore's law to hold true. As these transistors approach the atomic scale, however, further reduction becomes less probable and practical. As new technologies overcome these limitations, they face new, unexpected problems, including the ability to accurately simulate and predict the behavior of these devices, and to manage the heat they generate. This work uses a 3D Monte Carlo (MC) simulator to investigate the electro-thermal behavior of quasi-one-dimensional electron gas (1DEG) multigate MOSFETs. In order to study these highly confined architectures, the inclusion of quantum correction becomes essential. To better capture the influence of carrier confinement, the electrostatically quantum-corrected full-band MC model has the added feature of being able to incorporate subband scattering. The scattering rate selection introduces quantum correction into carrier movement. In addition to the quantum effects, scaling introduces thermal management issues due to the surge in power dissipation. Solving these problems will continue to bring improvements in battery life, performance, and size constraints of future devices. We have coupled our electron transport Monte Carlo simulation to Aksamija's phonon transport so that we may accurately and efficiently study carrier transport, heat generation, and other effects at the transistor level. This coupling utilizes anharmonic phonon decay and temperature dependent scattering rates. One immediate advantage of our coupled electro-thermal Monte Carlo simulator is its ability to provide an accurate description of the spatial variation of self-heating and its effect on non
Pros and Cons of ID vs. 3D Modeling
NASA Technical Reports Server (NTRS)
Klimchuk, James A.
2012-01-01
Advances in computing capability have led to tremendous improvements in 3D modeling. Entire active regions are being simulated in what might be described as a first principles way, in which plasma heating is treated self consistently rather than through the specification of heating functions. There are limitations to this approach, however, as actual heating mechanisms on the Sun involve spatial scales orders of magnitude smaller than what these simulations can resolve. Other simulations begin to resolve these scales, but they only treat a tiny volume and do not include the all important coupling with larger scales or with other parts of the atmosphere, and so cannot be readily compared with observations. Finally, ID hydrodynamic models capture the field-aligned evolution of the plasma extremely well and are ideally suited for data comparison, but they treat the heating in a totally ad hoc manner. All of these approaches have important contributions to make, but we must be aware of their limitations. I will highlight some of the strengths. and weaknesses of each.
A 3D world model builder with a mobile robot
Zhang, Z.; Faugeras, O. )
1992-08-01
This article describes a system to incrementally build a world model with a mobile robot in an unknown environment. The model is, for the moment, segment based. A trinocular stereo system is used to build a local map about the environment. A global map is obtained by integrating a sequence of stereo frames taken when the robot navigates in the environment. The emphasis of this article is on the representation of the uncertainty of 3D segments from stereo and on the integration of segments from multiple views. The proposed representation is simple and very convenient to characterize the uncertainty of segment. A Kalman filter is used to merge matched line segments. An important characteristic of this integration strategy is that a segment observed by the stereo system corresponds only to one part of the segment in space, so the union of the different observations gives a better estimate on the segment in space. The authors have succeeded in integrating 35 stereo frames taken in their robot room.
Modelling Polymer Deformation and Welding Behaviour during 3D Printing
NASA Astrophysics Data System (ADS)
McIlroy, Claire; Olmsted, Peter
2016-11-01
3D printing has the potential to transform manufacturing processes, yet improving the strength of printed parts, to equal that of traditionally-manufactured parts, remains an underlying issue. The most common method, fused deposition modelling, involves melting a thermoplastic, followed by layer-by-layer extrusion of the material to fabricate a three-dimensional object. The key to the ensuring strength at the weld between these layers is successful inter-diffusion. However, as the printed layer cools towards the glass transition temperature, the time available for diffusion is limited. In addition, the extrusion process significantly deforms the polymer micro-structure prior to welding and consequently affects how the polymers "re-entangle" across the weld. We have developed a simple model of the non-isothermal printing process to explore the effects that typical printing conditions and amorphous polymer rheology have on the ultimate weld structure. In particular, we incorporate both the stretch and orientation of the polymer using the Rolie-Poly constitutive equation to examine how the melt flows through the nozzle and is deposited onto the build plate. We then address how this deformation relaxes and contributes to the thickness and structure of the weld. National Institute for Standards and Technology (NIST) and Georgetown University.
A novel mechanotactic 3D modeling of cell morphology
NASA Astrophysics Data System (ADS)
Jamaleddin Mousavi, Seyed; Hamdy Doweidar, Mohamed
2014-08-01
Cell morphology plays a critical role in many biological processes, such as cell migration, tissue development, wound healing and tumor growth. Recent investigations demonstrate that, among other stimuli, cells adapt their shapes according to their substrate stiffness. Until now, the development of this process has not been clear. Therefore, in this work, a new three-dimensional (3D) computational model for cell morphology has been developed. This model is based on a previous cell migration model presented by the same authors. The new model considers that during cell-substrate interaction, cell shape is governed by internal cell deformation, which leads to an accurate prediction of the cell shape according to the mechanical characteristic of its surrounding micro-environment. To study this phenomenon, the model has been applied to different numerical cases. The obtained results, which are qualitatively consistent with well-known related experimental works, indicate that cell morphology not only depends on substrate stiffness but also on the substrate boundary conditions. A cell located within an unconstrained soft substrate (several kPa) with uniform stiffness is unable to adhere to its substrate or to send out pseudopodia. When the substrate stiffness increases to tens of kPa (intermediate and rigid substrates), the cell can adequately adhere to its substrate. Subsequently, as the traction forces exerted by the cell increase, the cell elongates and its shape changes. Within very stiff (hard) substrates, the cell cannot penetrate into its substrate or send out pseudopodia. On the other hand, a cell is found to be more elongated within substrates with a constrained surface. However, this elongation decreases when the cell approaches it. It can be concluded that the higher the net traction force, the greater the cell elongation, the larger the cell membrane area, and the less random the cell alignment.
Numerical model of sonic boom in 3D kinematic turbulence
NASA Astrophysics Data System (ADS)
Coulouvrat, François; Luquet, David; Marchiano, Régis
2015-10-01
stratified wind superimposed to a 3D random turbulent realization. Propagation is performed either in the case of a shadow zone or of an atmospheric waveguide. To model the turbulent ABL, the mean flow and the fluctuations are handled separately. The wind fluctuations are generated using the Random Fluctuations Generation method assuming a von Kármán spectrum and a homogeneous and isotropic turbulence. The mean stratified wind is modeled based on the Monin-Obhukov Similarity Theory (MOST). To illustrate the method, the typical case of a sunny day with a strong wind has been chosen. Statistics are obtained on several parameters. It shows the importance of turbulence, which leads to an increase of the mean maximum peak pressure in the shadow zone and to its decrease in the waveguide. Moreover, the formation of random caustics that can lead to an increase of the noise perceived locally is outlined.
Methods for Geometric Data Validation of 3d City Models
NASA Astrophysics Data System (ADS)
Wagner, D.; Alam, N.; Wewetzer, M.; Pries, M.; Coors, V.
2015-12-01
Geometric quality of 3D city models is crucial for data analysis and simulation tasks, which are part of modern applications of the data (e.g. potential heating energy consumption of city quarters, solar potential, etc.). Geometric quality in these contexts is however a different concept as it is for 2D maps. In the latter case, aspects such as positional or temporal accuracy and correctness represent typical quality metrics of the data. They are defined in ISO 19157 and should be mentioned as part of the metadata. 3D data has a far wider range of aspects which influence their quality, plus the idea of quality itself is application dependent. Thus, concepts for definition of quality are needed, including methods to validate these definitions. Quality on this sense means internal validation and detection of inconsistent or wrong geometry according to a predefined set of rules. A useful starting point would be to have correct geometry in accordance with ISO 19107. A valid solid should consist of planar faces which touch their neighbours exclusively in defined corner points and edges. No gaps between them are allowed, and the whole feature must be 2-manifold. In this paper, we present methods to validate common geometric requirements for building geometry. Different checks based on several algorithms have been implemented to validate a set of rules derived from the solid definition mentioned above (e.g. water tightness of the solid or planarity of its polygons), as they were developed for the software tool CityDoctor. The method of each check is specified, with a special focus on the discussion of tolerance values where they are necessary. The checks include polygon level checks to validate the correctness of each polygon, i.e. closeness of the bounding linear ring and planarity. On the solid level, which is only validated if the polygons have passed validation, correct polygon orientation is checked, after self-intersections outside of defined corner points and edges
Object-oriented urban 3D spatial data model organization method
NASA Astrophysics Data System (ADS)
Li, Jing-wen; Li, Wen-qing; Lv, Nan; Su, Tao
2015-12-01
This paper combined the 3d data model with object-oriented organization method, put forward the model of 3d data based on object-oriented method, implemented the city 3d model to quickly build logical semantic expression and model, solved the city 3d spatial information representation problem of the same location with multiple property and the same property with multiple locations, designed the space object structure of point, line, polygon, body for city of 3d spatial database, and provided a new thought and method for the city 3d GIS model and organization management.
NASA Astrophysics Data System (ADS)
Simmons, Gary G.; Howett, Carly J. A.; Young, Leslie A.; Spencer, John R.
2015-11-01
In the last few decades, thermal data from the Galileo and Cassini spacecraft have detected various anomalies on Jovian and Saturnian satellites, including the thermally anomalous “PacMan” regions on Mimas and Tethys and the Pwyll anomaly on Europa (Howett et al. 2011, Howett et al. 2012, Spencer et al. 1999). Yet, the peculiarities of some of these anomalies, like the weak detection of the “PacMan” anomalies on Rhea and Dione and the low thermal inertia values of the widespread anomalies on equatorial Europa, are subjects for on-going research (Howett et al. 2014, Rathbun et al. 2010). Further, analysis and review of all the data both Galileo and Cassini took of these worlds will provide information of the thermal inertia and albedos of their surfaces, perhaps highlighting potential targets of interest for future Jovian and Saturnian system missions. Many previous works have used a thermophysical model for airless planets developed by Spencer (1990). However, the Three Dimensional Volatile-Transport (VT3D) model proposed by Young (2012) is able to predict surface temperatures in significantly faster computation time, incorporating seasonal and diurnal insolation variations. This work is the first step in an ongoing investigation, which will use VT3D’s capabilities to reanalyze Galileo and Cassini data. VT3D, which has already been used to analyze volatile transport on Pluto, is validated by comparing its results to that of the Spencer thermal model. We will also present our initial results using VT3D to reanalyze the thermophysical properties of the PacMan anomaly previous discovered on Mimas by Howett et al. (2011), using temperature constraints of diurnal data from Cassini/CIRS. VT3D is expected to be an efficient tool in identifying new thermal anomalies in future Saturnian and Jovian missions.Bibliography:C.J.A. Howett et al. (2011), Icarus 216, 221.C.J.A. Howett et al. (2012), Icarus 221, 1084.C.J.A. Howett et al. (2014), Icarus 241, 239.J
3D Loop Models and the CPn-1 Sigma Model
NASA Astrophysics Data System (ADS)
Nahum, Adam; Chalker, J. T.; Serna, P.; Ortuño, M.; Somoza, A. M.
2011-09-01
Many statistical mechanics problems can be framed in terms of random curves; we consider a class of three-dimensional loop models that are prototypes for such ensembles. The models show transitions between phases with infinite loops and short-loop phases. We map them to CPn-1 sigma models, where n is the loop fugacity. Using Monte Carlo simulations, we find continuous transitions for n=1, 2, 3, and first order transitions for n≥5. The results are relevant to line defects in random media, as well as to Anderson localization and (2+1)-dimensional quantum magnets.
EM modeling for GPIR using 3D FDTD modeling codes
Nelson, S.D.
1994-10-01
An analysis of the one-, two-, and three-dimensional electrical characteristics of structural cement and concrete is presented. This work connects experimental efforts in characterizing cement and concrete in the frequency and time domains with the Finite Difference Time Domain (FDTD) modeling efforts of these substances. These efforts include Electromagnetic (EM) modeling of simple lossless homogeneous materials with aggregate and targets and the modeling dispersive and lossy materials with aggregate and complex target geometries for Ground Penetrating Imaging Radar (GPIR). Two- and three-dimensional FDTD codes (developed at LLNL) where used for the modeling efforts. Purpose of the experimental and modeling efforts is to gain knowledge about the electrical properties of concrete typically used in the construction industry for bridges and other load bearing structures. The goal is to optimize the performance of a high-sample-rate impulse radar and data acquisition system and to design an antenna system to match the characteristics of this material. Results show agreement to within 2 dB of the amplitudes of the experimental and modeled data while the frequency peaks correlate to within 10% the differences being due to the unknown exact nature of the aggregate placement.
West Flank Coso, CA FORGE 3D temperature model
Doug Blankenship
2016-03-01
x,y,z data of the 3D temperature model for the West Flank Coso FORGE site. Model grid spacing is 250m. The temperature model for the Coso geothermal field used over 100 geothermal production sized wells and intermediate-depth temperature holes. At the near surface of this model, two boundary temperatures were assumed: (1) areas with surface manifestations, including fumaroles along the northeast striking normal faults and northwest striking dextral faults with the hydrothermal field, a temperature of ~104ËšC was applied to datum at +1066 meters above sea level elevation, and (2) a near-surface temperature at about 10 meters depth, of 20ËšC was applied below the diurnal and annual conductive temperature perturbations. These assumptions were based on heat flow studies conducted at the CVF and for the Mojave Desert. On the edges of the hydrothermal system, a 73ËšC/km (4ËšF/100â€™) temperature gradient contour was established using conductive gradient data from shallow and intermediate-depth temperature holes. This contour was continued to all elevation datums between the 20ËšC surface and -1520 meters below mean sea level. Because the West Flank is outside of the geothermal field footprint, during Phase 1, the three wells inside the FORGE site were incorporated into the preexisting temperature model. To ensure a complete model was built based on all the available data sets, measured bottom-hole temperature gradients in certain wells were downward extrapolated to the next deepest elevation datum (or a maximum of about 25% of the well depth where conductive gradients are evident in the lower portions of the wells). After assuring that the margins of the geothermal field were going to be adequately modelled, the data was contoured using the Kriging method algorithm. Although the extrapolated temperatures and boundary conditions are not rigorous, the calculated temperatures are anticipated to be within ~6ËšC (20ËšF), or one contour interval, of the
Prediction models from CAD models of 3D objects
NASA Astrophysics Data System (ADS)
Camps, Octavia I.
1992-11-01
In this paper we present a probabilistic prediction based approach for CAD-based object recognition. Given a CAD model of an object, the PREMIO system combines techniques of analytic graphics and physical models of lights and sensors to predict how features of the object will appear in images. In nearly 4,000 experiments on analytically-generated and real images, we show that in a semi-controlled environment, predicting the detectability of features of the image can successfully guide a search procedure to make informed choices of model and image features in its search for correspondences that can be used to hypothesize the pose of the object. Furthermore, we provide a rigorous experimental protocol that can be used to determine the optimal number of correspondences to seek so that the probability of failing to find a pose and of finding an inaccurate pose are minimized.
3D Simulation Modeling of the Tooth Wear Process.
Dai, Ning; Hu, Jian; Liu, Hao
2015-01-01
Severe tooth wear is the most common non-caries dental disease, and it can seriously affect oral health. Studying the tooth wear process is time-consuming and difficult, and technological tools are frequently lacking. This paper presents a novel method of digital simulation modeling that represents a new way to study tooth wear. First, a feature extraction algorithm is used to obtain anatomical feature points of the tooth without attrition. Second, after the alignment of non-attrition areas, the initial homogeneous surface is generated by means of the RBF (Radial Basic Function) implicit surface and then deformed to the final homogeneous by the contraction and bounding algorithm. Finally, the method of bilinear interpolation based on Laplacian coordinates between tooth with attrition and without attrition is used to inversely reconstruct the sequence of changes of the 3D tooth morphology during gradual tooth wear process. This method can also be used to generate a process simulation of nonlinear tooth wear by means of fitting an attrition curve to the statistical data of attrition index in a certain region. The effectiveness and efficiency of the attrition simulation algorithm are verified through experimental simulation.
3D Simulation Modeling of the Tooth Wear Process
Dai, Ning; Hu, Jian; Liu, Hao
2015-01-01
Severe tooth wear is the most common non-caries dental disease, and it can seriously affect oral health. Studying the tooth wear process is time-consuming and difficult, and technological tools are frequently lacking. This paper presents a novel method of digital simulation modeling that represents a new way to study tooth wear. First, a feature extraction algorithm is used to obtain anatomical feature points of the tooth without attrition. Second, after the alignment of non-attrition areas, the initial homogeneous surface is generated by means of the RBF (Radial Basic Function) implicit surface and then deformed to the final homogeneous by the contraction and bounding algorithm. Finally, the method of bilinear interpolation based on Laplacian coordinates between tooth with attrition and without attrition is used to inversely reconstruct the sequence of changes of the 3D tooth morphology during gradual tooth wear process. This method can also be used to generate a process simulation of nonlinear tooth wear by means of fitting an attrition curve to the statistical data of attrition index in a certain region. The effectiveness and efficiency of the attrition simulation algorithm are verified through experimental simulation. PMID:26241942
Hsu, S Y; Chen, H Y; Chen, K N
2012-03-01
Diffusion behaviors of co-sputtered metals during thermal treatments were investigated, where these co-sputtered metals can be used as bonding materials for 3D Interconnects. In this paper, we report the diffusion behaviors and discuss the diffusion mechanisms of co-sputtered metals before and after annealing. Atom and vacancy volume, vacancy formation energy, and activation energy are proposed to explain the diffusion direction and diffusion rate among different co-sputtered metals. Based on the excellent bonding performance of this method, Cu/metal co-sputtering bonding is considered as a potential candidate for advanced bonding technology.
3D numerical thermal stress analysis of the high power target for the SLC Positron Source
Reuter, E.M.; Hodgson, J.A.
1991-05-01
The volumetrically nonuniform power deposition of the incident 33 GeV electron beam in the SLC Positron Source Target is hypothesized to be the most likely cause target failure. The resultant pulsed temperature distributions are known to generate complicated stress fields with no known closed-form analytical solution. 3D finite element analyses of these temperature distributions and associated thermal stress fields in the new High Power Target are described here. Operational guidelines based on the results of these analyses combined with assumptions made about the fatigue characteristics of the exotic target material are proposed. 6 refs., 4 figs.
Brien, Dianne L.; Reid, Mark E.
2007-01-01
Landslides are a common problem on coastal bluffs throughout the world. Along the coastal bluffs of the Puget Sound in Seattle, Washington, landslides range from small, shallow failures to large, deep-seated landslides. Landslides of all types can pose hazards to human lives and property, but deep-seated landslides are of significant concern because their large areal extent can cause extensive property damage. Although many geomorphic processes shape the coastal bluffs of Seattle, we focus on large (greater than 3,000 m3), deepseated, rotational landslides that occur on the steep bluffs along Puget Sound. Many of these larger failures occur in advance outwash deposits of the Vashon Drift (Qva); some failures extend into the underlying Lawton Clay Member of the Vashon Drift (Qvlc). The slope stability of coastal bluffs is controlled by the interplay of three-dimensional (3-D) variations in gravitational stress, strength, and pore-water pressure. We assess 3-D slope-stability using SCOOPS (Reid and others, 2000), a computer program that allows us to search a high-resolution digital-elevation model (DEM) to quantify the relative stability of all parts of the landscape by computing the stability and volume of thousands of potential spherical failures. SCOOPS incorporates topography, 3-D strength variations, and 3-D pore pressures. Initially, we use our 3-D analysis methods to examine the effects of topography and geology by using heterogeneous material properties, as defined by stratigraphy, without pore pressures. In this scenario, the least-stable areas are located on the steepest slopes, commonly in Qva or Qvlc. However, these locations do not agree well with observations of deep-seated landslides. Historically, both shallow colluvial landslides and deep-seated landslides have been observed near the contact between Qva and Qvlc, and commonly occur in Qva. The low hydraulic conductivity of Qvlc impedes ground-water flow, resulting in elevated pore pressures at the
Verification and Validation of the k-kL Turbulence Model in FUN3D and CFL3D Codes
NASA Technical Reports Server (NTRS)
Abdol-Hamid, Khaled S.; Carlson, Jan-Renee; Rumsey, Christopher L.
2015-01-01
The implementation of the k-kL turbulence model using multiple computational uid dy- namics (CFD) codes is reported herein. The k-kL model is a two-equation turbulence model based on Abdol-Hamid's closure and Menter's modi cation to Rotta's two-equation model. Rotta shows that a reliable transport equation can be formed from the turbulent length scale L, and the turbulent kinetic energy k. Rotta's equation is well suited for term-by-term mod- eling and displays useful features compared to other two-equation models. An important di erence is that this formulation leads to the inclusion of higher-order velocity derivatives in the source terms of the scale equations. This can enhance the ability of the Reynolds- averaged Navier-Stokes (RANS) solvers to simulate unsteady ows. The present report documents the formulation of the model as implemented in the CFD codes Fun3D and CFL3D. Methodology, veri cation and validation examples are shown. Attached and sepa- rated ow cases are documented and compared with experimental data. The results show generally very good comparisons with canonical and experimental data, as well as matching results code-to-code. The results from this formulation are similar or better than results using the SST turbulence model.
A Numerical Study on the Thermal Conductivity of 3D Woven C/C Composites at High Temperature
NASA Astrophysics Data System (ADS)
Shigang, Ai; Rujie, He; Yongmao, Pei
2015-12-01
Experimental data for Carbon/Carbon (C/C) constituent materials are combined with a three dimensional steady state heat transfer finite element analysis to demonstrate the average in-plane and out-of-plane thermal conductivities (TCs) of C/C composites. The finite element analysis is carried out at two distinct length scales: (a) a micro scale comparable with the diameter of carbon fibres and (b) a meso scale comparable with the carbon fibre yarns. Micro-scale model calculate the TCs at the fibre yarn scale in the three orthogonal directions ( x, y and z). The output results from the micro-scale model are then incorporated in the meso-scale model to obtain the global TCs of the 3D C/C composite. The simulation results are quite consistent with the theoretical and experimental counterparts reported in references. Based on the numerical approach, TCs of the 3D C/C composite are calculated from 300 to 2500 K. Particular attention is given in elucidating the variations of the TCs with temperature. The multi-scale models provide an efficient approach to predict the TCs of 3D textile materials, which is helpful for the thermodynamic property analysis and structure design of the C/C composites.
Explicit 3D continuum fracture modeling with smooth particle hydrodynamics
NASA Technical Reports Server (NTRS)
Benz, W.; Asphaug, E.
1993-01-01
Impact phenomena shaped our solar system. As usual for most solar system processes, the scales are far different than we can address directly in the laboratory. Impact velocities are often much higher than we can achieve, sizes are often vastly larger, and most impacts take place in an environment where the only gravitational force is the mutual pull of the impactors. The Smooth Particle Hydrodynamics (SPH) technique has been applied in the past to the simulations of giant impacts. In these simulations, the colliding objects were so massive (at least a sizeable fraction of the Earth's mass) that material strength was negligible compared to gravity. This assumption can no longer be made when the bodies are much smaller. To this end, we have developed a 3D SPH code that includes a strength model to which we have added a von Mises yielding relation for stresses beyond the Hugoniot Elastic Limit. At the lower stresses associated with brittle failure, we use a rate-dependent strength based on the nucleation of incipient flaws whose number density is given by a Weibull distribution. Following Grady and Kipp and Melosh et al., we introduce a state variable D ('damage'), 0 less than D less than 1, which expresses the local reduction in strength due to crack growth under tensile loading. Unfortunately for the hydrodynamics, Grady and Kipp's model predicts which fragments are the most probable ones and not the ones that are really formed. This means, for example, that if a given laboratory experiment is modeled, the fragment distribution obtained from the Grady-Kipp theory would be equivalent to a ensemble average over many realizations of the experiment. On the other hand, the hydrodynamics itself is explicit and evolves not an ensemble average but very specific fragments. Hence, there is a clear incompatibility with the deterministic nature of the hydrodynamics equations and the statistical approach of the Grady-Kipp dynamical fracture model. We remedy these shortcomings
Lee, Hyungseok; Yoo, James J; Kang, Hyun-Wook; Cho, Dong-Woo
2016-02-04
Recently, numerous three-dimensional (3D) bioprinting systems have been introduced for the artificial regeneration of tissues. Among them, the extrusion-based dispensing module is the most widely used because of the processability it gives various biomaterials. The module uses high forces and temperature to dispense materials through a micro-nozzle. Generally, the harsh conditions induce thermal degradation of the material in the dispensing procedure. The thermal degradation affects the properties of the materials, and the change of the properties should be carefully controlled, because it severely affects the regeneration of tissues. Therefore, in this research, the relationship between the dispensing module and the thermal degradation of material was investigated. Extrusion-based dispensing modules can be divided into the syringe type (ST) and filament type (FT) based on working principles. We prepared a poly lactic-co-glycolic acid (PLGA) scaffold with the two methods at various time points. Then, the characteristics of the printed scaffolds were assessed by measuring molecular weight (M w), glass transition temperature (T g), in vitro degradation, compressive modulus, and cytocompatibility. The results showed that the PLGA scaffold with the FT dispensing module maintained its properties regardless of printing time points. In contrast, severe thermal degradation was observed in the scaffold group prepared by the ST dispensing module. Consequentially, it was obvious that the FT dispensing module was more suitable for producing scaffolds without severe thermal degradation.
Numerical Results of 3-D Modeling of Moon Accumulation
NASA Astrophysics Data System (ADS)
Khachay, Yurie; Anfilogov, Vsevolod; Antipin, Alexandr
2014-05-01
For the last time for the model of the Moon usually had been used the model of mega impact in which the forming of the Earth and its sputnik had been the consequence of the Earth's collision with the body of Mercurial mass. But all dynamical models of the Earth's accumulation and the estimations after the Pb-Pb system, lead to the conclusion that the duration of the planet accumulation was about 1 milliard years. But isotopic results after the W-Hf system testify about a very early (5-10) million years, dividing of the geochemical reservoirs of the core and mantle. In [1,2] it is shown, that the account of energy dissipating by the decay of short living radioactive elements and first of all Al26,it is sufficient for heating even small bodies with dimensions about (50-100) km up to the iron melting temperature and can be realized a principal new differentiation mechanism. The inner parts of the melted preplanets can join and they are mainly of iron content, but the cold silicate fragments return to the supply zone and additionally change the content of Moon forming to silicates. Only after the increasing of the gravitational radius of the Earth, the growing area of the future Earth's core can save also the silicate envelope fragments [3]. For understanding the further system Earth-Moon evolution it is significant to trace the origin and evolution of heterogeneities, which occur on its accumulation stage.In that paper we are modeling the changing of temperature,pressure,velocity of matter flowing in a block of 3d spherical body with a growing radius. The boundary problem is solved by the finite-difference method for the system of equations, which include equations which describe the process of accumulation, the Safronov equation, the equation of impulse balance, equation Navier-Stocks, equation for above litho static pressure and heat conductivity in velocity-pressure variables using the Businesque approach.The numerical algorithm of the problem solution in velocity
Orbiter/External Tank Mate 3-D Solid Modeling
NASA Technical Reports Server (NTRS)
Godfrey, G. S.; Brandt, B.; Rorden, D.; Kapr, F.
2004-01-01
This research and development project presents an overview of the work completed while attending a summer 2004 American Society of Engineering Education/National Aeronautics and Space Administration (ASEE/NASA) Faculty Fellowship. This fellowship was completed at the Kennedy Space Center, Florida. The scope of the project was to complete parts, assemblies, and drawings that could be used by Ground Support Equipment (GSE) personnel to simulate situations and scenarios commonplace to the space shuttle Orbiter/External Tank (ET) Mate (50004). This mate takes place in the Vehicle Assembly Building (VAB). These simulations could then be used by NASA engineers as decision-making tools. During the summer of 2004, parts were created that defined the Orbiter/ET structural interfaces. Emphasis was placed upon assemblies that included the Orbiter/ET forward attachment (EO-1), aft left thrust strut (EO-2), aft right tripod support structure (EO-3), and crossbeam and aft feedline/umbilical supports. These assemblies are used to attach the Orbiter to the ET. The Orbiter/ET Mate assembly was then used to compare and analyze clearance distances using different Orbiter hang angles. It was found that a 30-minute arc angle change in Orbiter hang angle affected distance at the bipod strut to Orbiter yoke fitting 8.11 inches. A 3-D solid model library was established as a result of this project. This library contains parts, assemblies, and drawings translated into several formats. This library contains a collection of the following files: sti for sterolithography, stp for neutral file work, shrinkwrap for compression. tiff for photoshop work, jpeg for Internet use, and prt and asm for Pro/Engineer use. This library was made available to NASA engineers so that they could access its contents to make angle, load, and clearance analysis studies. These decision-making tools may be used by Pro/Engineer users and non-users.
Automated robust generation of compact 3D statistical shape models
NASA Astrophysics Data System (ADS)
Vrtovec, Tomaz; Likar, Bostjan; Tomazevic, Dejan; Pernus, Franjo
2004-05-01
Ascertaining the detailed shape and spatial arrangement of anatomical structures is important not only within diagnostic settings but also in the areas of planning, simulation, intraoperative navigation, and tracking of pathology. Robust, accurate and efficient automated segmentation of anatomical structures is difficult because of their complexity and inter-patient variability. Furthermore, the position of the patient during image acquisition, the imaging device and protocol, image resolution, and other factors induce additional variations in shape and appearance. Statistical shape models (SSMs) have proven quite successful in capturing structural variability. A possible approach to obtain a 3D SSM is to extract reference voxels by precisely segmenting the structure in one, reference image. The corresponding voxels in other images are determined by registering the reference image to each other image. The SSM obtained in this way describes statistically plausible shape variations over the given population as well as variations due to imperfect registration. In this paper, we present a completely automated method that significantly reduces shape variations induced by imperfect registration, thus allowing a more accurate description of variations. At each iteration, the derived SSM is used for coarse registration, which is further improved by describing finer variations of the structure. The method was tested on 64 lumbar spinal column CT scans, from which 23, 38, 45, 46 and 42 volumes of interest containing vertebra L1, L2, L3, L4 and L5, respectively, were extracted. Separate SSMs were generated for each vertebra. The results show that the method is capable of reducing the variations induced by registration errors.
3D Geological Model of Nihe ore deposit Constrained by Gravity and Magnetic Modeling
NASA Astrophysics Data System (ADS)
Qi, Guang; Yan, Jiayong; Lv, Qingtan; Zhao, Jinhua
2016-04-01
We present a case study on using integrated geologic model in mineral exploration at depth. Nihe ore deposit in Anhui Province, is deep hidden ore deposit which was discovered in recent years, this finding is the major driving force of deep mineral exploration work in Luzong. Building 3D elaborate geological model has the important significance for prospecting to deep or surround in this area, and can help us better understand the metallogenic law and ore-controlling regularity. A 3D geological model, extending a depth from +200m to -1500m in Nihe ore deposit, has been compiled from surface geological map, cross-section, borehole logs and amounts of geological inference. And then the 3D geological models have been given physical property parameter for calculating the potential field. Modelling the potential response is proposed as means of evaluating the viability of the 3D geological models, and the evidence of making small changes to the uncertain parts of the original 3D geological models. It is expected that the final models not only reproduce supplied prior geological knowledge, but also explain the observed geophysical data. The workflow used to develop the 3D geologic model in this study includes the three major steps, as follows: (1) Determine the basic information of Model: Defining the 3D limits of the model area, the basic geological and structural unit, and the tectonic contact relations and the sedimentary sequences between these units. (2) 3D model construction: Firstly, a series of 2D geological cross sections over the model area are built by using all kinds of prior information, including surface geology, borehole data, seismic sections, and local geologists' knowledge and intuition. Lastly, we put these sections into a 3D environment according to their profile locations to build a 3D model by using geostatistics method. (3) 3D gravity and magnetic modeling: we calculate the potential field responses of the 3D model, and compare the predicted and
Modeling Computer Communication Networks in a Realistic 3D Environment
2010-03-01
visualization in OPNET . . . . . . . . . . . . 13 6. Sample NetViz visualization . . . . . . . . . . . . . . . . . . . 15 7. Realistic 3D terrains...scenario in OPNET . . . 19 10. OPNET 3DNV only displays connectivity . . . . . . . . . . . . 29 11. The digitally connected battlefield...confirmation tool 12 OPNET Optimized Network Evaluation Tool . . . . . . . . . . . . 13 NetViz Network Visualization
3D genome structure modeling by Lorentzian objective function.
Trieu, Tuan; Cheng, Jianlin
2016-11-29
The 3D structure of the genome plays a vital role in biological processes such as gene interaction, gene regulation, DNA replication and genome methylation. Advanced chromosomal conformation capture techniques, such as Hi-C and tethered conformation capture, can generate chromosomal contact data that can be used to computationally reconstruct 3D structures of the genome. We developed a novel restraint-based method that is capable of reconstructing 3D genome structures utilizing both intra-and inter-chromosomal contact data. Our method was robust to noise and performed well in comparison with a panel of existing methods on a controlled simulated data set. On a real Hi-C data set of the human genome, our method produced chromosome and genome structures that are consistent with 3D FISH data and known knowledge about the human chromosome and genome, such as, chromosome territories and the cluster of small chromosomes in the nucleus center with the exception of the chromosome 18. The tool and experimental data are available at https://missouri.box.com/v/LorDG.
Using 3D Geometric Models to Teach Spatial Geometry Concepts.
ERIC Educational Resources Information Center
Bertoline, Gary R.
1991-01-01
An explanation of 3-D Computer Aided Design (CAD) usage to teach spatial geometry concepts using nontraditional techniques is presented. The software packages CADKEY and AutoCAD are described as well as their usefulness in solving space geometry problems. (KR)
Geological, isothermal, and isobaric 3-D model construction in early stage of geothermal exploration
NASA Astrophysics Data System (ADS)
Saputra, M. P.; Suryantini; Catigtig, D.; Regandara, R.; Asnin, S. N.; Pratama, A. B.
2016-09-01
Construction of geology, thermal anomaly and pressure distribution of a geothermal system in the early stage of exploration where data is limited is described using a 3-D software, Leapfrog Geothermal. The geological 3-D model was developed from a topographic map (derived from DEM data), geological map and literature studies reported in an early geological survey. The isothermal 3-D model was constructed using reservoir temperature estimation from geothermometry calculated from chemical analyses on surface manifestations, available shallow gradient temperature hole data and the normal gradient temperature (3°C/100m) for a nonthermal area. The isobaric 3-D model was built using hydrostatic pressure where the hydrostatic pressure is determined by the product of the fluid density, acceleration due to gravity, and depth. Fluid density is given by saturated liquid density as a function of temperature. There are some constraints on the modelling result such as (1) within the predicted reservoir, the geothermal gradient is not constant but continues to increase, thus, creating an anomalously high temperature at depth, and (2) the lithology model is made by interpolating and extrapolating cross-sections whereas usually only two to three geology sections were available for this study. Hence, the modeller must understand the geology. An additional cross section was developed by the modeller which may not be as suitable as the geologist constructed sections. The results of this study can be combined with geophysical data such as gravity, geomagnetic, micro-tremor and resistivity data. The combination of geological, geochemical, isothermal, isobaric and geophysical data could be used in (1) estimating the geometry and size of the geothermal reservoir, (2) predicting the depth of top reservoir, and (3) creating well prognosis for exploration and production wells.
Examination of 1D Solar Cell Model Limitations Using 3D SPICE Modeling: Preprint
McMahon, W. E.; Olson, J. M.; Geisz, J. F.; Friedman, D. J.
2012-06-01
To examine the limitations of one-dimensional (1D) solar cell modeling, 3D SPICE-based modeling is used to examine in detail the validity of the 1D assumptions as a function of sheet resistance for a model cell. The internal voltages and current densities produced by this modeling give additional insight into the differences between the 1D and 3D models.
Kang, Da-Young; Kim, Cheolho; Park, Gyurim; Moon, Jun Hyuk
2015-01-01
The direct pyrolytic carbonisation of polymer patterns has attracted interest for its use in obtaining carbon materials. In the case of carbonisation of nanopatterned polymers, the polymer flow and subsequent pattern change may occur in order to relieve their high surface energies. Here, we demonstrated that liquid immersion thermal crosslinking of polymer nanopatterns effectively enhanced the thermal resistance and maintained the structure integrity during the heat treatment. We employed the liquid immersion thermal crosslinking for 3D porous SU8 photoresist nanopatterns and successfully converted them to carbon nanopatterns while maintaining their porous features. The thermal crosslinking reaction and carbonisation of SU8 nanopatterns were characterised. The micro-crystallinity of the SU8-derived carbon nanopatterns was also characterised. The liquid immersion heat treatment can be extended to the carbonisation of various polymer or photoresist nanopatterns and also provide a facile way to control the surface energy of polymer nanopatterns for various purposes, for example, to block copolymer or surfactant self-assemblies. PMID:26677949
Quasi-Facial Communication for Online Learning Using 3D Modeling Techniques
ERIC Educational Resources Information Center
Wang, Yushun; Zhuang, Yueting
2008-01-01
Online interaction with 3D facial animation is an alternative way of face-to-face communication for distance education. 3D facial modeling is essential for virtual educational environments establishment. This article presents a novel 3D facial modeling solution that facilitates quasi-facial communication for online learning. Our algorithm builds…
NASA Astrophysics Data System (ADS)
Martínez, José M.; Jarosz, Boguslaw J.
2015-03-01
Thermal therapy has emerged as an independent modality of treating some tumors. In many clinics the hyperthermia, one of the thermal therapy modalities, has been used adjuvant to radio- or chemotherapy to substantially improve the clinical treatment outcomes. In this work, a methodology for building a realistic brain phantom for interstitial ultrasound low dose-rate thermal therapy of the brain is proposed. A 3D brain phantom made of the tissue mimicking material (TMM) had the acoustic and thermal properties in the 20-32 °C range, which is similar to that of a brain at 37 °C. The phantom had 10-11% by mass of bovine gelatin powder dissolved in ethylene glycol. The TMM sonicated at 1 MHz, 1.6 MHz and 2.5 MHz yielded the amplitude attenuation coefficients of 62 ± 1 dB m-1, 115 ± 4 dB m-1 and 175 ± 9 dB m-1, respectively. The density and acoustic speed determination at room temperature (~24 °C) gave 1040 ± 40 kg m-3 and 1545 ± 44 m s-1, respectively. The average thermal conductivity was 0.532 W m-1 K-1. The T1 and T2 values of the TMM were 207 ± 4 and 36.2 ± 0.4 ms, respectively. We envisage the use of our phantom for treatment planning and for quality assurance in MRI based temperature determination. Our phantom preparation methodology may be readily extended to other thermal therapy technologies.
Martínez, José M; Jarosz, Boguslaw J
2015-03-07
Thermal therapy has emerged as an independent modality of treating some tumors. In many clinics the hyperthermia, one of the thermal therapy modalities, has been used adjuvant to radio- or chemotherapy to substantially improve the clinical treatment outcomes. In this work, a methodology for building a realistic brain phantom for interstitial ultrasound low dose-rate thermal therapy of the brain is proposed. A 3D brain phantom made of the tissue mimicking material (TMM) had the acoustic and thermal properties in the 20-32 °C range, which is similar to that of a brain at 37 °C. The phantom had 10-11% by mass of bovine gelatin powder dissolved in ethylene glycol. The TMM sonicated at 1 MHz, 1.6 MHz and 2.5 MHz yielded the amplitude attenuation coefficients of 62 ± 1 dB m(-1), 115 ± 4 dB m(-1) and 175 ± 9 dB m(-1), respectively. The density and acoustic speed determination at room temperature (~24 °C) gave 1040 ± 40 kg m(-3) and 1545 ± 44 m s(-1), respectively. The average thermal conductivity was 0.532 W m(-1) K(-1). The T1 and T2 values of the TMM were 207 ± 4 and 36.2 ± 0.4 ms, respectively. We envisage the use of our phantom for treatment planning and for quality assurance in MRI based temperature determination. Our phantom preparation methodology may be readily extended to other thermal therapy technologies.
Numerical Results of Earth's Core Accumulation 3-D Modelling
NASA Astrophysics Data System (ADS)
Khachay, Yurie; Anfilogov, Vsevolod
2013-04-01
For a long time as a most convenient had been the model of mega impact in which the early forming of the Earth's core and mantle had been the consequence of formed protoplanet collision with the body of Mercurial mass. But all dynamical models of the Earth's accumulation and the estimations after the Pb-Pb system, lead to the conclusion that the duration of the planet accumulation was about 1 milliard years. But isotopic results after the W-Hf system testify about a very early (5-10) million years, dividing of the geochemical reservoirs of the core and mantle. In [1,3] it is shown, that the account of energy dissipating by the decay of short living radioactive elements and first of all Al,it is sufficient for heating even small bodies with dimensions about (50-100) km up to the iron melting temperature and can be realized a principal new differentiation mechanism. The inner parts of the melted preplanets can join and they are mainly of iron content, but the cold silicate fragments return to the supply zone. Only after the increasing of the gravitational radius, the growing area of the future core can save also the silicate envelope fragments. All existing dynamical accumulation models are constructed by using a spherical-symmetrical model. Hence for understanding the further planet evolution it is significant to trace the origin and evolution of heterogeneities, which occur on the planet accumulation stage. In that paper we are modeling distributions of temperature, pressure, velocity of matter flowing in a block of 3D- spherical body with a growing radius. The boundary problem is solved by the finite-difference method for the system of equations, which include equations which describe the process of accumulation, the Safronov equation, the equation of impulse balance, equation Navier-Stocks, equation for above litho static pressure and heat conductivity in velocity-pressure variables using the Businesque approach. The numerical algorithm of the problem solution in
Howard Barker; Jason Cole
2012-05-17
Utilization of cloud-resolving models and multi-dimensional radiative transfer models to investigate the importance of 3D radiation effects on the numerical simulation of cloud fields and their properties.
Dynamic Characteristics of a Model and Prototype for 3D-RC Structure
NASA Astrophysics Data System (ADS)
Moniuddin, Md. Khaja; Vasanthalakshmi, G.; Chethan, K.; Babu, R. Ramesh
2016-06-01
Infill walls provide durable and economical partitions that have relatively excellent thermal and sound insulation with high fire resistance. Monolithic infilled walls are provided within RC structures without being analyzed as a combination of concrete and brick elements, although in reality they act as a single unit during earthquakes. The performance of such structures during earthquakes has proved to be superior in comparison to bare frames in terms of stiffness, strength and energy dissipation. To know the dynamic characteristics of monolithic infill wall panels and masonry infill, modal, response spectrum and time history analyses have been carried out on a model and prototype of a 3D RC structure for a comparative study.
3D neutronic codes coupled with thermal-hydraulic system codes for PWR, and BWR and VVER reactors
Langenbuch, S.; Velkov, K.; Lizorkin, M.
1997-07-01
This paper describes the objectives of code development for coupling 3D neutronics codes with thermal-hydraulic system codes. The present status of coupling ATHLET with three 3D neutronics codes for VVER- and LWR-reactors is presented. After describing the basic features of the 3D neutronic codes BIPR-8 from Kurchatov-Institute, DYN3D from Research Center Rossendorf and QUABOX/CUBBOX from GRS, first applications of coupled codes for different transient and accident scenarios are presented. The need of further investigations is discussed.
Fast, Automated, 3D Modeling of Building Interiors
2012-10-30
of thermographies with laser scanning point clouds [6]. Given the heterogeneous nature of the two modalities, we propose a feature-based approach...extract 2D lines from thermographies , and 3D lines are extracted through segmentation of the point cloud. Feature- matching and the relative pose between... thermographies and point cloud are obtained from an iterative procedure applied to detect and reject outliers; this includes rotation matrix and
Naik, Dinesh N; Ezawa, Takahiro; Singh, Rakesh Kumar; Miyamoto, Yoko; Takeda, Mitsuo
2012-08-27
We propose a new technique for achromatic 3-D field correlation that makes use of the characteristics of both axial and lateral magnifications of imaging through a common-path Sagnac shearing interferometer. With this technique, we experimentally demonstrate, for the first time to our knowledge, 3-D image reconstruction of coherence holography with generic thermal light. By virtue of the achromatic axial shearing implemented by the difference in axial magnifications in imaging, the technique enables coherence holography to reconstruct a 3-D object with an axial depth beyond the short coherence length of the thermal light.
NASA Astrophysics Data System (ADS)
Autin, J.; Scheck-Wenderoth, M.; Götze, H.-J.; Reichert, C.; Marchal, D.
2016-04-01
Following previous work on the Colorado Basin using a 3D crustal structural model, we now investigate the presence of lower crustal bodies at the base of the crust using 3D lithospheric gravity modelling and calculations of the conductive thermal field. Our first study highlighted two fault directions and depocentres associated with thinned crust (NW-SE in the West and NE-SW at the distal margin). Fault relative chronology argues for two periods of extension: (1) NW-SE faulting and thinning in the western Colorado Basin and (2) NE-SW faulting and thinning related to the continental breakup and formation of the NE-SW-striking volcanic margins of the Atlantic Ocean. In this study, the geometry of modelled high-density Lower Crustal Bodies (LCBs) enables the reproduction of the gravimetric field as well as of the temperature measured in wells down to 4500 m. The modelled LCBs correlate with geological observations: (1) NW-SE LCBs below the deepest depocentres in the West, (2) NE-SW LCBs below the distal margin faults and the seaward dipping reflectors. Thus the proposed poly-phased evolution of the margin could as well correspond to two emplacement phases of the LCBs. The calculated conductive thermal field fits the measured temperatures best if the thermal properties (thermal conductivity and radiogenic heat production) assigned to the LCBs correspond to either high-grade metamorphic rocks or to mafic magmatic intrusions. To explain the possible lithology of the LCBs, we propose that the two successive phases of extension are accompanied by magma supply, emplaced (1) in the thinnest crust below the older NW-SE depocentres, then (2) along the NE-SW continentward boundary of the distal margin and below the volcanic seaward dipping reflectors. The South African conjugate margin records only the second NE-SW event and we discuss hypotheses which could explain these differences between the conjugate margins.
Numerical modelling of gravel unconstrained flow experiments with the DAN3D and RASH3D codes
NASA Astrophysics Data System (ADS)
Sauthier, Claire; Pirulli, Marina; Pisani, Gabriele; Scavia, Claudio; Labiouse, Vincent
2015-12-01
Landslide continuum dynamic models have improved considerably in the last years, but a consensus on the best method of calibrating the input resistance parameter values for predictive analyses has not yet emerged. In the present paper, numerical simulations of a series of laboratory experiments performed at the Laboratory for Rock Mechanics of the EPF Lausanne were undertaken with the RASH3D and DAN3D numerical codes. They aimed at analysing the possibility to use calibrated ranges of parameters (1) in a code different from that they were obtained from and (2) to simulate potential-events made of a material with the same characteristics as back-analysed past-events, but involving a different volume and propagation path. For this purpose, one of the four benchmark laboratory tests was used as past-event to calibrate the dynamic basal friction angle assuming a Coulomb-type behaviour of the sliding mass, and this back-analysed value was then used to simulate the three other experiments, assumed as potential-events. The computational findings show good correspondence with experimental results in terms of characteristics of the final deposits (i.e., runout, length and width). Furthermore, the obtained best fit values of the dynamic basal friction angle for the two codes turn out to be close to each other and within the range of values measured with pseudo-dynamic tilting tests.
Virtual and Printed 3D Models for Teaching Crystal Symmetry and Point Groups
ERIC Educational Resources Information Center
Casas, Lluís; Estop, Euge`nia
2015-01-01
Both, virtual and printed 3D crystal models can help students and teachers deal with chemical education topics such as symmetry and point groups. In the present paper, two freely downloadable tools (interactive PDF files and a mobile app) are presented as examples of the application of 3D design to study point-symmetry. The use of 3D printing to…
Analysis of 3D Modeling Software Usage Patterns for K-12 Students
ERIC Educational Resources Information Center
Wu, Yi-Chieh; Liao, Wen-Hung; Chi, Ming-Te; Li, Tsai-Yen
2016-01-01
In response to the recent trend in maker movement, teachers are learning 3D techniques actively and bringing 3D printing into the classroom to enhance variety and creativity in designing lectures. This study investigates the usage pattern of a 3D modeling software, Qmodel Creator, which is targeted at K-12 students. User logs containing…
ODTLES : a model for 3D turbulent flow based on one-dimensional turbulence modeling concepts.
McDermott, Randy; Kerstein, Alan R.; Schmidt, Rodney Cannon
2005-01-01
This report describes an approach for extending the one-dimensional turbulence (ODT) model of Kerstein [6] to treat turbulent flow in three-dimensional (3D) domains. This model, here called ODTLES, can also be viewed as a new LES model. In ODTLES, 3D aspects of the flow are captured by embedding three, mutually orthogonal, one-dimensional ODT domain arrays within a coarser 3D mesh. The ODTLES model is obtained by developing a consistent approach for dynamically coupling the different ODT line sets to each other and to the large scale processes that are resolved on the 3D mesh. The model is implemented computationally and its performance is tested and evaluated by performing simulations of decaying isotropic turbulence, a standard turbulent flow benchmarking problem.
Cloud-resolving component in the quasi-3D multi-scale modeling framework
NASA Astrophysics Data System (ADS)
Jung, Joon-Hee; Arakawa, Akio
2010-05-01
A quasi-3D multi-scale modeling framework (Q3D MMF), which combines a GCM with a Q3D CRM, is an attempt to include three dimensional cloud effects in a GCM without necessarily using a global cloud-resolving model. The horizontal domain of the Q3D CRM consists of two perpendicular sets of channels crossing at the center of a GCM grid box, each of which includes two grid-point arrays. Through coupling this structure with a GCM, the whole system of the Q3D MMF can converge to a fully 3D global CRM as the GCM's resolution is refined. Consequently, the horizontal resolution of the GCM can be freely chosen depending on the objective of application. However, due to the use of very narrow channels for the cloud-resolving component, its prediction algorithm must be specially designed. As a step in developing a Q3D MMF, we have first constructed a prediction algorithm for the Q3D CRM applying a 3D anelastic vector vorticity equation model to the Q3D network of grid points. Preliminary tests of the Q3D CRM have been performed for an idealized small domain. Comparing the results with those of the straightforward application of a 3D CRM, it is concluded that the Q3D CRM can reproduce most of the important statistics of the 3D solutions and the MMF based on the Q3D CRM will be a useful framework for climate modeling. This paper presents an outline of the Q3D algorithm and highlights of the results.
TOPICAL REVIEW: Computational approaches to 3D modeling of RNA
NASA Astrophysics Data System (ADS)
Laing, Christian; Schlick, Tamar
2010-07-01
Many exciting discoveries have recently revealed the versatility of RNA and its importance in a variety of functions within the cell. Since the structural features of RNA are of major importance to their biological function, there is much interest in predicting RNA structure, either in free form or in interaction with various ligands, including proteins, metabolites and other molecules. In recent years, an increasing number of researchers have developed novel RNA algorithms for predicting RNA secondary and tertiary structures. In this review, we describe current experimental and computational advances and discuss recent ideas that are transforming the traditional view of RNA folding. To evaluate the performance of the most recent RNA 3D folding algorithms, we provide a comparative study in order to test the performance of available 3D structure prediction algorithms for an RNA data set of 43 structures of various lengths and motifs. We find that the algorithms vary widely in terms of prediction quality across different RNA lengths and topologies; most predictions have very large root mean square deviations from the experimental structure. We conclude by outlining some suggestions for future RNA folding research.
Interpretation and mapping of geological features using mobile devices for 3D outcrop modelling
NASA Astrophysics Data System (ADS)
Buckley, Simon J.; Kehl, Christian; Mullins, James R.; Howell, John A.
2016-04-01
Advances in 3D digital geometric characterisation have resulted in widespread adoption in recent years, with photorealistic models utilised for interpretation, quantitative and qualitative analysis, as well as education, in an increasingly diverse range of geoscience applications. Topographic models created using lidar and photogrammetry, optionally combined with imagery from sensors such as hyperspectral and thermal cameras, are now becoming commonplace in geoscientific research. Mobile devices (tablets and smartphones) are maturing rapidly to become powerful field computers capable of displaying and interpreting 3D models directly in the field. With increasingly high-quality digital image capture, combined with on-board sensor pose estimation, mobile devices are, in addition, a source of primary data, which can be employed to enhance existing geological models. Adding supplementary image textures and 2D annotations to photorealistic models is therefore a desirable next step to complement conventional field geoscience. This contribution reports on research into field-based interpretation and conceptual sketching on images and photorealistic models on mobile devices, motivated by the desire to utilise digital outcrop models to generate high quality training images (TIs) for multipoint statistics (MPS) property modelling. Representative training images define sedimentological concepts and spatial relationships between elements in the system, which are subsequently modelled using artificial learning to populate geocellular models. Photorealistic outcrop models are underused sources of quantitative and qualitative information for generating TIs, explored further in this research by linking field and office workflows through the mobile device. Existing textured models are loaded to the mobile device, allowing rendering in a 3D environment. Because interpretation in 2D is more familiar and comfortable for users, the developed application allows new images to be captured
Closed-loop high-speed 3D thermal probe nanolithography
NASA Astrophysics Data System (ADS)
Knoll, A. W.; Zientek, M.; Cheong, L. L.; Rawlings, C.; Paul, P.; Holzner, F.; Hedrick, J. L.; Coady, D. J.; Allen, R.; Dürig, U.
2014-03-01
Thermal Scanning Probe Lithography (tSPL) is an AFM based patterning technique, which uses heated tips to locally evaporate organic resists such as molecular glasses [1] or thermally sensitive polymers.[2][3] Organic resists offer the versatility of the lithography process known from the CMOS environment and simultaneously ensure a highly stable and low wear tip-sample contact due to the soft nature of the resists. Patterning quality is excellent up to a resolution of sub 15 nm,[1] at linear speeds of up to 20 mm/s and pixel rates of up to 500 kHz.[4] The patterning depth is proportional to the applied force which allows for the creation of 3-D profiles in a single patterning run.[2] In addition, non-destructive imaging can be done at pixel rates of more than 500 kHz.[4] If the thermal stimulus for writing the pattern is switched off the same tip can be used to record the written topography with Angstrom depth resolution. We utilize this unique feature of SPL to implement an efficient control system for reliable patterning at high speed and high resolution. We combine the writing and imaging process in a single raster scan of the surface. In this closed loop lithography (CLL) approach, we use the acquired data to optimize the writing parameters on the fly. Excellent control is in particular important for an accurate reproduction of complex 3D patterns. These novel patterning capabilities are equally important for a high quality transfer of two-dimensional patterns into the underlying substrate. We utilize an only 3-4 nm thick SiOx hardmask to amplify the 8±0.5 nm deep patterns created by tSPL into a 50 nm thick transfer polymer. The structures in the transfer polymer can be used to create metallic lines by a lift-off process or to further process the pattern into the substrate. Here we demonstrate the fabrication of 27 nm wide lines and trenches 60 nm deep into the Silicon substrate.[5] In addition, the combined read and write approach ensures that the lateral
Procedural 3d Modelling for Traditional Settlements. The Case Study of Central Zagori
NASA Astrophysics Data System (ADS)
Kitsakis, D.; Tsiliakou, E.; Labropoulos, T.; Dimopoulou, E.
2017-02-01
Over the last decades 3D modelling has been a fast growing field in Geographic Information Science, extensively applied in various domains including reconstruction and visualization of cultural heritage, especially monuments and traditional settlements. Technological advances in computer graphics, allow for modelling of complex 3D objects achieving high precision and accuracy. Procedural modelling is an effective tool and a relatively novel method, based on algorithmic modelling concept. It is utilized for the generation of accurate 3D models and composite facade textures from sets of rules which are called Computer Generated Architecture grammars (CGA grammars), defining the objects' detailed geometry, rather than altering or editing the model manually. In this paper, procedural modelling tools have been exploited to generate the 3D model of a traditional settlement in the region of Central Zagori in Greece. The detailed geometries of 3D models derived from the application of shape grammars on selected footprints, and the process resulted in a final 3D model, optimally describing the built environment of Central Zagori, in three levels of Detail (LoD). The final 3D scene was exported and published as 3D web-scene which can be viewed with 3D CityEngine viewer, giving a walkthrough the whole model, same as in virtual reality or game environments. This research work addresses issues regarding textures' precision, LoD for 3D objects and interactive visualization within one 3D scene, as well as the effectiveness of large scale modelling, along with the benefits and drawbacks that derive from procedural modelling techniques in the field of cultural heritage and more specifically on 3D modelling of traditional settlements.
A Deformable Generic 3D Model of Haptoral Anchor of Monogenean
Teo, Bee Guan; Dhillon, Sarinder Kaur; Lim, Lee Hong Susan
2013-01-01
In this paper, a digital 3D model which allows for visualisation in three dimensions and interactive manipulation is explored as a tool to help us understand the structural morphology and elucidate the functions of morphological structures of fragile microorganisms which defy live studies. We developed a deformable generic 3D model of haptoral anchor of dactylogyridean monogeneans that can subsequently be deformed into different desired anchor shapes by using direct manipulation deformation technique. We used point primitives to construct the rectangular building blocks to develop our deformable 3D model. Point primitives are manually marked on a 2D illustration of an anchor on a Cartesian graph paper and a set of Cartesian coordinates for each point primitive is manually extracted from the graph paper. A Python script is then written in Blender to construct 3D rectangular building blocks based on the Cartesian coordinates. The rectangular building blocks are stacked on top or by the side of each other following their respective Cartesian coordinates of point primitive. More point primitives are added at the sites in the 3D model where more structural variations are likely to occur, in order to generate complex anchor structures. We used Catmull-Clark subdivision surface modifier to smoothen the surface and edge of the generic 3D model to obtain a smoother and more natural 3D shape and antialiasing option to reduce the jagged edges of the 3D model. This deformable generic 3D model can be deformed into different desired 3D anchor shapes through direct manipulation deformation technique by aligning the vertices (pilot points) of the newly developed deformable generic 3D model onto the 2D illustrations of the desired shapes and moving the vertices until the desire 3D shapes are formed. In this generic 3D model all the vertices present are deployed for displacement during deformation. PMID:24204903
A deformable generic 3D model of haptoral anchor of Monogenean.
Teo, Bee Guan; Dhillon, Sarinder Kaur; Lim, Lee Hong Susan
2013-01-01
In this paper, a digital 3D model which allows for visualisation in three dimensions and interactive manipulation is explored as a tool to help us understand the structural morphology and elucidate the functions of morphological structures of fragile microorganisms which defy live studies. We developed a deformable generic 3D model of haptoral anchor of dactylogyridean monogeneans that can subsequently be deformed into different desired anchor shapes by using direct manipulation deformation technique. We used point primitives to construct the rectangular building blocks to develop our deformable 3D model. Point primitives are manually marked on a 2D illustration of an anchor on a Cartesian graph paper and a set of Cartesian coordinates for each point primitive is manually extracted from the graph paper. A Python script is then written in Blender to construct 3D rectangular building blocks based on the Cartesian coordinates. The rectangular building blocks are stacked on top or by the side of each other following their respective Cartesian coordinates of point primitive. More point primitives are added at the sites in the 3D model where more structural variations are likely to occur, in order to generate complex anchor structures. We used Catmull-Clark subdivision surface modifier to smoothen the surface and edge of the generic 3D model to obtain a smoother and more natural 3D shape and antialiasing option to reduce the jagged edges of the 3D model. This deformable generic 3D model can be deformed into different desired 3D anchor shapes through direct manipulation deformation technique by aligning the vertices (pilot points) of the newly developed deformable generic 3D model onto the 2D illustrations of the desired shapes and moving the vertices until the desire 3D shapes are formed. In this generic 3D model all the vertices present are deployed for displacement during deformation.
Large scale 3-D modeling by integration of resistivity models and borehole data through inversion
NASA Astrophysics Data System (ADS)
Foged, N.; Marker, P. A.; Christansen, A. V.; Bauer-Gottwein, P.; Jørgensen, F.; Høyer, A.-S.; Auken, E.
2014-02-01
We present an automatic method for parameterization of a 3-D model of the subsurface, integrating lithological information from boreholes with resistivity models through an inverse optimization, with the objective of further detailing for geological models or as direct input to groundwater models. The parameter of interest is the clay fraction, expressed as the relative length of clay-units in a depth interval. The clay fraction is obtained from lithological logs and the clay fraction from the resistivity is obtained by establishing a simple petrophysical relationship, a translator function, between resistivity and the clay fraction. Through inversion we use the lithological data and the resistivity data to determine the optimum spatially distributed translator function. Applying the translator function we get a 3-D clay fraction model, which holds information from the resistivity dataset and the borehole dataset in one variable. Finally, we use k means clustering to generate a 3-D model of the subsurface structures. We apply the concept to the Norsminde survey in Denmark integrating approximately 700 boreholes and more than 100 000 resistivity models from an airborne survey in the parameterization of the 3-D model covering 156 km2. The final five-cluster 3-D model differentiates between clay materials and different high resistive materials from information held in resistivity model and borehole observations respectively.
Large-scale 3-D modeling by integration of resistivity models and borehole data through inversion
NASA Astrophysics Data System (ADS)
Foged, N.; Marker, P. A.; Christansen, A. V.; Bauer-Gottwein, P.; Jørgensen, F.; Høyer, A.-S.; Auken, E.
2014-11-01
We present an automatic method for parameterization of a 3-D model of the subsurface, integrating lithological information from boreholes with resistivity models through an inverse optimization, with the objective of further detailing of geological models, or as direct input into groundwater models. The parameter of interest is the clay fraction, expressed as the relative length of clay units in a depth interval. The clay fraction is obtained from lithological logs and the clay fraction from the resistivity is obtained by establishing a simple petrophysical relationship, a translator function, between resistivity and the clay fraction. Through inversion we use the lithological data and the resistivity data to determine the optimum spatially distributed translator function. Applying the translator function we get a 3-D clay fraction model, which holds information from the resistivity data set and the borehole data set in one variable. Finally, we use k-means clustering to generate a 3-D model of the subsurface structures. We apply the procedure to the Norsminde survey in Denmark, integrating approximately 700 boreholes and more than 100 000 resistivity models from an airborne survey in the parameterization of the 3-D model covering 156 km2. The final five-cluster 3-D model differentiates between clay materials and different high-resistivity materials from information held in the resistivity model and borehole observations, respectively.
A Quantification of the 3D Modeling Capabilities of the Kinectfusion Algorithm
2014-03-27
A QUANTIFICATION OF THE 3D MODELING CAPABILITIES OF THE KINECTFUSTION ALGORITHM THESIS Jeremy M. Higbee, Captain, USAF AFIT-ENG-14-M-40 DEPARTMENT OF...subject to copyright protection in the United States. AFIT-ENG-14-M-40 A QUANTIFICATION OF THE 3D MODELING CAPABILITIES OF THE KINECTFUSTION ALGORITHM...M-40 A QUANTIFICATION OF THE 3D MODELING CAPABILITIES OF THE KINECTFUSTION ALGORITHM Jeremy M. Higbee, BS Captain, USAF Approved: /signed/ Maj Brian
Implementation of algebraic stress models in a general 3-D Navier-Stokes method (PAB3D)
NASA Technical Reports Server (NTRS)
Abdol-Hamid, Khaled S.
1995-01-01
A three-dimensional multiblock Navier-Stokes code, PAB3D, which was developed for propulsion integration and general aerodynamic analysis, has been used extensively by NASA Langley and other organizations to perform both internal (exhaust) and external flow analysis of complex aircraft configurations. This code was designed to solve the simplified Reynolds Averaged Navier-Stokes equations. A two-equation k-epsilon turbulence model has been used with considerable success, especially for attached flows. Accurate predicting of transonic shock wave location and pressure recovery in separated flow regions has been more difficult. Two algebraic Reynolds stress models (ASM) have been recently implemented in the code that greatly improved the code's ability to predict these difficult flow conditions. Good agreement with Direct Numerical Simulation (DNS) for a subsonic flat plate was achieved with ASM's developed by Shih, Zhu, and Lumley and Gatski and Speziale. Good predictions were also achieved at subsonic and transonic Mach numbers for shock location and trailing edge boattail pressure recovery on a single-engine afterbody/nozzle model.
Determination of Experimental Fuel Rod Parameters using 3D Modelling of PCMI with MPS Defect
Casagranda, Albert; Spencer, Benjamin Whiting; Pastore, Giovanni; Novascone, Stephen Rhead; Hales, Jason Dean; Williamson, Richard L; Martineau, Richard Charles
2016-05-01
An in-reactor experiment is being designed in order to validate the pellet-cladding mechanical interaction (PCMI) behavior of the BISON fuel performance code. The experimental parameters for the test rod being placed in the Halden Research Reactor are being determined using BISON simulations. The 3D model includes a missing pellet surface (MPS) defect to generate large local cladding deformations, which should be measureable after typical burnup times. The BISON fuel performance code is being developed at Idaho National Laboratory (INL) and is built on the Multiphysics Object-Oriented Simulation Environment (MOOSE) framework. BISON supports both 2D and 3D finite elements and solves the fully coupled equations for solid mechanics, heat conduction and species diffusion. A number of fuel performance effects are included using models for swelling, densification, creep, relocation and fission gas production & release. In addition, the mechanical and thermal contact between the fuel and cladding is explicitly modelled using a master-slave based contact algorithm. In order to accurately predict PCMI effects, the BISON code includes the relevant physics involved and provides a scalable and robust solution procedure. The depth of the proposed MPS defect is being varied in the BISON model to establish an optimum value for the experiment. The experiment will be interrupted approximately every 6 months to measure cladding radial deformation and provide data to validate BISON. The complete rodlet (~20 discrete pellets) is being simulated using a 180° half symmetry 3D model with MPS defects at two axial locations. In addition, annular pellets will be used at the top and bottom of the pellet stack to allow thermocouples within the rod to measure the fuel centerline temperature. Simulation results will be presented to illustrate the expected PCMI behavior and support the chosen experimental design parameters.
Analysis of Experimental Fuel Rod Parameters using 3D Modelling of PCMI with MPS Defect
Casagranda, Albert; Spencer, Benjamin Whiting; Pastore, Giovanni; Novascone, Stephen Rhead; Hales, Jason Dean; Williamson, Richard L; Martineau, Richard Charles
2016-06-01
An in-reactor experiment is being designed in order to validate the pellet-cladding mechanical interaction (PCMI) behavior of the BISON fuel performance code. The experimental parameters for the test rod being placed in the Halden Research Reactor are being determined using BISON simulations. The 3D model includes a missing pellet surface (MPS) defect to generate large local cladding deformations, which should be measureable after typical burnup times. The BISON fuel performance code is being developed at Idaho National Laboratory (INL) and is built on the Multiphysics Object-Oriented Simulation Environment (MOOSE) framework. BISON supports both 2D and 3D finite elements and solves the fully coupled equations for solid mechanics, heat conduction and species diffusion. A number of fuel performance effects are included using models for swelling, densification, creep, relocation and fission gas production & release. In addition, the mechanical and thermal contact between the fuel and cladding is explicitly modelled using a master-slave based contact algorithm. In order to accurately predict PCMI effects, the BISON code includes the relevant physics involved and provides a scalable and robust solution procedure. The depth of the proposed MPS defect is being varied in the BISON model to establish an optimum value for the experiment. The experiment will be interrupted approximately every 6 months to measure cladding radial deformation and provide data to validate BISON. The complete rodlet (~20 discrete pellets) is being simulated using a 180° half symmetry 3D model with MPS defects at two axial locations. In addition, annular pellets will be used at the top and bottom of the pellet stack to allow thermocouples within the rod to measure the fuel centerline temperature. Simulation results will be presented to illustrate the expected PCMI behavior and support the chosen experimental design parameters.
Developing and Testing a 3d Cadastral Data Model a Case Study in Australia
NASA Astrophysics Data System (ADS)
Aien, A.; Kalantari, M.; Rajabifard, A.; Williamson, I. P.; Shojaei, D.
2012-07-01
Population growth, urbanization and industrialization place more pressure on land use with the need for increased space. To extend the use and functionality of the land, complex infrastructures are being built, both vertically and horizontally, layered and stacked. These three-dimensional (3D) developments affect the interests (Rights, Restrictions, and Responsibilities (RRRs)) attached to the underlying land. A 3D cadastre will assist in managing the effects of 3D development on a particular extent of land. There are many elements that contribute to developing a 3D cadastre, such as existing of 3D property legislations, 3D DBMS, 3D visualization. However, data modelling is one of the most important elements of a successful 3D cadastre. As architectural models of houses and high rise buildings help their users visualize the final product, 3D cadastre data model supports 3D cadastre users to understand the structure or behavior of the system and has a template that guides them to construct and implement the 3D cadastre. Many jurisdictions, organizations and software developers have built their own cadastral data model. Land Administration Domain Model (DIS-ISO 19152, The Netherlands) and ePlan (Intergovernmental Committee on Surveying and Mapping, Australia) are examples of existing data models. The variation between these data models is the result of different attitudes towards cadastres. However, there is a basic common thread among them all. Current cadastral data models use a 2D land-parcel concept and extend it to support 3D requirements. These data models cannot adequately manage and represent the spatial extent of 3D RRRs. Most of the current cadastral data models have been influenced by a very broad understanding of 3D cadastral concepts because better clarity in what needs to be represented and analysed in the cadastre needs to be established. This paper presents the first version of a 3D Cadastral Data Model (3DCDM_Version 1.0). 3DCDM models both the legal
Detection of Disease Symptoms on Hyperspectral 3d Plant Models
NASA Astrophysics Data System (ADS)
Roscher, Ribana; Behmann, Jan; Mahlein, Anne-Katrin; Dupuis, Jan; Kuhlmann, Heiner; Plümer, Lutz
2016-06-01
We analyze the benefit of combining hyperspectral images information with 3D geometry information for the detection of Cercospora leaf spot disease symptoms on sugar beet plants. Besides commonly used one-class Support Vector Machines, we utilize an unsupervised sparse representation-based approach with group sparsity prior. Geometry information is incorporated by representing each sample of interest with an inclination-sorted dictionary, which can be seen as an 1D topographic dictionary. We compare this approach with a sparse representation based approach without geometry information and One-Class Support Vector Machines. One-Class Support Vector Machines are applied to hyperspectral data without geometry information as well as to hyperspectral images with additional pixelwise inclination information. Our results show a gain in accuracy when using geometry information beside spectral information regardless of the used approach. However, both methods have different demands on the data when applied to new test data sets. One-Class Support Vector Machines require full inclination information on test and training data whereas the topographic dictionary approach only need spectral information for reconstruction of test data once the dictionary is build by spectra with inclination.
A new approach towards image based virtual 3D city modeling by using close range photogrammetry
NASA Astrophysics Data System (ADS)
Singh, S. P.; Jain, K.; Mandla, V. R.
2014-05-01
3D city model is a digital representation of the Earth's surface and it's related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing day to day for various engineering and non-engineering applications. Generally three main image based approaches are using for virtual 3D city models generation. In first approach, researchers used Sketch based modeling, second method is Procedural grammar based modeling and third approach is Close range photogrammetry based modeling. Literature study shows that till date, there is no complete solution available to create complete 3D city model by using images. These image based methods also have limitations This paper gives a new approach towards image based virtual 3D city modeling by using close range photogrammetry. This approach is divided into three sections. First, data acquisition process, second is 3D data processing, and third is data combination process. In data acquisition process, a multi-camera setup developed and used for video recording of an area. Image frames created from video data. Minimum required and suitable video image frame selected for 3D processing. In second section, based on close range photogrammetric principles and computer vision techniques, 3D model of area created. In third section, this 3D model exported to adding and merging of other pieces of large area. Scaling and alignment of 3D model was done. After applying the texturing and rendering on this model, a final photo-realistic textured 3D model created. This 3D model transferred into walk-through model or in movie form. Most of the processing steps are automatic. So this method is cost effective and less laborious. Accuracy of this model is good. For this research work, study area is the campus of department of civil engineering, Indian Institute of Technology, Roorkee. This campus acts as a prototype for city. Aerial photography is restricted in many country
NASA Astrophysics Data System (ADS)
Afonso, J. C.; Fullea, J.; Yang, Y.; Griffin, W. L.; Jones, A. G.; Connolly, J.; Lebedev, S.; O'Reilly, S. Y.
2011-12-01
High-resolution imaging and characterization of the thermal and compositional structure of the lithospheric and sublithospheric upper mantle are the basis for understanding the formation and evolution of the lithosphere and the interaction between the crust-mantle and lithosphere-asthenosphere systems. Unfortunately, such imaging and characterization using available geophysical-geochemical methods still present unsolved and technically challenging problems. In this contribution we present a new full-3D multi-observable inversion method particularly designed for high-resolution (regional) thermal and compositional mapping of the lithosphere and sublithospheric upper mantle. Ambient noise tomography, multiple plane wave earthquake tomography, magnetotelluric, thermal, thermodynamic, and potential field modelling are all combined in a single thermodynamic-geophysical framework and appraised within a general probabilistic (Bayesian) formulation. This circumvents the problems of strong non-linearity involved in traditional inversions, provides highly refined seismic information, minimizes the problem of trade-off between temperature and composition in wave speeds, offers critical insights into incompatibilities between traditional stand-alone methods, and takes advantage of a priori local geochemical information. Both synthetic models and preliminary results in real-case examples will be used to discuss the benefits, robustness, and limitations of this method.
A crust-scale 3D structural model of the Beaufort-Mackenzie Basin (Arctic Canada)
NASA Astrophysics Data System (ADS)
Sippel, Judith; Scheck-Wenderoth, Magdalena; Lewerenz, Björn; Kroeger, Karsten Friedrich
2013-04-01
thicknesses of Mesozoic-Cenozoic sediments (almost 17 km) are not found in the north where the sub-sedimentary crust is thinnest, but farther south where the crust is thicker and the Moho quite deep. We causally relate the huge amounts of foredeep deposits overlying a Moho depression to a flexural response of the lithosphere to orogenic loading induced by the Brooks Range orogen in the south. Our 3D model provides an ideal base and reference for future numerical studies including reconstructions of the development from a passive margin to a foreland basin and simulations of the present-day thermal field of the basin.
NASA Astrophysics Data System (ADS)
Zhuang, Xiao; Zhou, Yongcun; Liu, Feng
2017-01-01
We explored a novel 3D sandwich structure of fillers in the polymer matrix to enhance thermal conductivity. A variety of fillers in the polymer matrix play a significant role in the physical properties of the composite. Fillers containing particle and line structures are popular, and enhance the thermal and electrical conductivities. Therefore, filler-based matrix network improves conductivity. We propose a sandwich structure consisting of hybrid graphite nanosheets (two dimensions), and silver nanowires (AgNWs) (one dimension), to create a 3D sandwich structure of polyimide matrix with improved thermal conductivity. Surface treatment of graphite and silver nanowires were conducted to reduce the dielectric constant of the composite. We designed the filler of 20 wt% resulting in a high thermal conductivity of 3.21 W m‑1 K‑1 with 15% C@SiO2 and 5% AgNWs@SiO2 filler loading. The novel combination and structure markedly enhanced the thermal conductivity of the composite.
Temperature distributions in the laser-heated diamond anvil cell from 3-D numerical modeling
Rainey, E. S. G.; Kavner, A.; Hernlund, J. W.
2013-11-28
We present TempDAC, a 3-D numerical model for calculating the steady-state temperature distribution for continuous wave laser-heated experiments in the diamond anvil cell. TempDAC solves the steady heat conduction equation in three dimensions over the sample chamber, gasket, and diamond anvils and includes material-, temperature-, and direction-dependent thermal conductivity, while allowing for flexible sample geometries, laser beam intensity profile, and laser absorption properties. The model has been validated against an axisymmetric analytic solution for the temperature distribution within a laser-heated sample. Example calculations illustrate the importance of considering heat flow in three dimensions for the laser-heated diamond anvil cell. In particular, we show that a “flat top” input laser beam profile does not lead to a more uniform temperature distribution or flatter temperature gradients than a wide Gaussian laser beam.
Slab detachment in laterally varying subduction zones: 3-D numerical modeling
NASA Astrophysics Data System (ADS)
Duretz, T.; Gerya, T. V.; Spakman, W.
2014-03-01
Understanding the three-dimensional (3-D) dynamics of subduction-collision systems is a longstanding challenge in geodynamics. We investigate the impact of slab detachment in collision systems that are subjected to along-trench variations. High-resolution thermomechanical numerical models, encompassing experimentally derived flow laws and a pseudo free surface, are employed to unravel lithospheric and topographic evolutions. First, we consider coeval subduction of adjacent continental and oceanic lithospheres (SCO). This configuration yields to two-stage slab detachment during collision, topographic buildup and extrusion, variable along-trench convergence rates, and associated trench deformation. The second setting considers a convergent margin, which is laterally limited by a transform boundary (STB). Such collisional system is affected by a single slab detachment, little trench deformation, and moderately confined upper plate topography. The effect of initial thermal slab age on SCO and STB models are explored. Similarities with natural analogs along the Arabia-Eurasia collision are discussed.
3D Building Models Segmentation Based on K-Means++ Cluster Analysis
NASA Astrophysics Data System (ADS)
Zhang, C.; Mao, B.
2016-10-01
3D mesh model segmentation is drawing increasing attentions from digital geometry processing field in recent years. The original 3D mesh model need to be divided into separate meaningful parts or surface patches based on certain standards to support reconstruction, compressing, texture mapping, model retrieval and etc. Therefore, segmentation is a key problem for 3D mesh model segmentation. In this paper, we propose a method to segment Collada (a type of mesh model) 3D building models into meaningful parts using cluster analysis. Common clustering methods segment 3D mesh models by K-means, whose performance heavily depends on randomized initial seed points (i.e., centroid) and different randomized centroid can get quite different results. Therefore, we improved the existing method and used K-means++ clustering algorithm to solve this problem. Our experiments show that K-means++ improves both the speed and the accuracy of K-means, and achieve good and meaningful results.
NASA Astrophysics Data System (ADS)
Ebrahimi, Farzad; Barati, Mohammad Reza
2016-09-01
This article examines the application of nonlocal strain gradient elasticity theory to wave dispersion behavior of a size-dependent functionally graded (FG) nanobeam in thermal environment. The theory contains two scale parameters corresponding to both nonlocal and strain gradient effects. A quasi-3D sinusoidal beam theory considering shear and normal deformations is employed to present the formulation. Mori-Tanaka micromechanical model is used to describe functionally graded material properties. Hamilton's principle is employed to obtain the governing equations of nanobeam accounting for thickness stretching effect. These equations are solved analytically to find the wave frequencies and phase velocities of the FG nanobeam. It is indicated that wave dispersion behavior of FG nanobeams is significantly affected by temperature rise, nonlocality, length scale parameter and material composition.
NASA Astrophysics Data System (ADS)
Koehl, M.; Brigand, N.
2012-08-01
The site of the Engelbourg ruined castle in Thann, Alsace, France, has been for some years the object of all the attention of the city, which is the owner, and also of partners like historians and archaeologists who are in charge of its study. The valuation of the site is one of the main objective, as well as its conservation and its knowledge. The aim of this project is to use the environment of the virtual tour viewer as new base for an Archaeological Knowledge and Information System (AKIS). With available development tools we add functionalities in particular through diverse scripts that convert the viewer into a real 3D interface. By beginning with a first virtual tour that contains about fifteen panoramic images, the site of about 150 times 150 meters can be completely documented by offering the user a real interactivity and that makes visualization very concrete, almost lively. After the choice of pertinent points of view, panoramic images were realized. For the documentation, other sets of images were acquired at various seasons and climate conditions, which allow documenting the site in different environments and states of vegetation. The final virtual tour was deducted from them. The initial 3D model of the castle, which is virtual too, was also joined in the form of panoramic images for completing the understanding of the site. A variety of types of hotspots were used to connect the whole digital documentation to the site, including videos (as reports during the acquisition phases, during the restoration works, during the excavations, etc.), digital georeferenced documents (archaeological reports on the various constituent elements of the castle, interpretation of the excavations and the searches, description of the sets of collected objects, etc.). The completely personalized interface of the system allows either to switch from a panoramic image to another one, which is the classic case of the virtual tours, or to go from a panoramic photographic image
NASA Astrophysics Data System (ADS)
Qu, Jingyuan; Kadic, Muamer; Naber, Andreas; Wegener, Martin
2017-01-01
Controlling the thermal expansion of materials is of great technological importance. Uncontrolled thermal expansion can lead to failure or irreversible destruction of structures and devices. In ordinary crystals, thermal expansion is governed by the asymmetry of the microscopic binding potential, which cannot be adjusted easily. In artificial crystals called metamaterials, thermal expansion can be controlled by structure. Here, following previous theoretical work, we fabricate three-dimensional (3D) two-component polymer micro-lattices by using gray-tone laser lithography. We perform cross-correlation analysis of optical microscopy images taken at different sample temperatures. The derived displacement-vector field reveals that the thermal expansion and resulting bending of the bi-material beams leads to a rotation of the 3D chiral crosses arranged onto a 3D checkerboard pattern within one metamaterial unit cell. These rotations can compensate the expansion of the all positive constituents, leading to an effectively near-zero thermal length-expansion coefficient, or over-compensate the expansion, leading to an effectively negative thermal length-expansion coefficient. This evidences a striking level of thermal-expansion control.
Qu, Jingyuan; Kadic, Muamer; Naber, Andreas; Wegener, Martin
2017-01-01
Controlling the thermal expansion of materials is of great technological importance. Uncontrolled thermal expansion can lead to failure or irreversible destruction of structures and devices. In ordinary crystals, thermal expansion is governed by the asymmetry of the microscopic binding potential, which cannot be adjusted easily. In artificial crystals called metamaterials, thermal expansion can be controlled by structure. Here, following previous theoretical work, we fabricate three-dimensional (3D) two-component polymer micro-lattices by using gray-tone laser lithography. We perform cross-correlation analysis of optical microscopy images taken at different sample temperatures. The derived displacement-vector field reveals that the thermal expansion and resulting bending of the bi-material beams leads to a rotation of the 3D chiral crosses arranged onto a 3D checkerboard pattern within one metamaterial unit cell. These rotations can compensate the expansion of the all positive constituents, leading to an effectively near-zero thermal length-expansion coefficient, or over-compensate the expansion, leading to an effectively negative thermal length-expansion coefficient. This evidences a striking level of thermal-expansion control. PMID:28079161
Qu, Jingyuan; Kadic, Muamer; Naber, Andreas; Wegener, Martin
2017-01-12
Controlling the thermal expansion of materials is of great technological importance. Uncontrolled thermal expansion can lead to failure or irreversible destruction of structures and devices. In ordinary crystals, thermal expansion is governed by the asymmetry of the microscopic binding potential, which cannot be adjusted easily. In artificial crystals called metamaterials, thermal expansion can be controlled by structure. Here, following previous theoretical work, we fabricate three-dimensional (3D) two-component polymer micro-lattices by using gray-tone laser lithography. We perform cross-correlation analysis of optical microscopy images taken at different sample temperatures. The derived displacement-vector field reveals that the thermal expansion and resulting bending of the bi-material beams leads to a rotation of the 3D chiral crosses arranged onto a 3D checkerboard pattern within one metamaterial unit cell. These rotations can compensate the expansion of the all positive constituents, leading to an effectively near-zero thermal length-expansion coefficient, or over-compensate the expansion, leading to an effectively negative thermal length-expansion coefficient. This evidences a striking level of thermal-expansion control.
Interface requirements to couple thermal-hydraulic codes to 3D neutronic codes
Langenbuch, S.; Austregesilo, H.; Velkov, K.
1997-07-01
The present situation of thermalhydraulics codes and 3D neutronics codes is briefly described and general considerations for coupling of these codes are discussed. Two different basic approaches of coupling are identified and their relative advantages and disadvantages are discussed. The implementation of the coupling for 3D neutronics codes in the system ATHLET is presented. Meanwhile, this interface is used for coupling three different 3D neutronics codes.
Comparing thin-sheet models with 3-D multilayer models for continental collision
NASA Astrophysics Data System (ADS)
Lechmann, S. M.; May, D. A.; Kaus, B. J. P.; Schmalholz, S. M.
2011-10-01
Various models have been proposed to explain tectonic deformations during continent collision. A frequently applied model is the thin viscous sheet model which is however not fully 3-D and assumes a priori diffuse thickening as the dominant deformation style. We compare a fully 3-D multilayer numerical model with a corresponding thin viscous sheet numerical model for the scenario of continent indentation. In our comparison we focus on the three basic viscous deformation styles thickening, buckling (folding) and lateral crustal flow. Both numerical models are based on the finite element method (FEM) and employ either a linear or power-law viscous rheology. The 3-D model consists of four layers representing a simplified continental lithosphere: strong upper crust, weak lower crust, strong upper mantle and weak lower mantle. The effective viscosity depth-profile in the 3-D model is used to calculate the depth-averaged effective viscosity used in the thin-sheet model allowing a direct comparison of both models. We quantify the differences in the strain rate and velocity fields, and investigate the evolution of crustal thickening, buckling and crustal flow resulting from the two models for two different phases of deformation: (1) indentation with a constant velocity and (2) gravitational collapse after a decrease of the indenting velocity by a factor of 5. The results indicate that thin-sheet models approximate well the overall large-scale lithospheric deformation, especially during indentation and for a linear viscous rheology. However, in the 3-D model, additional processes such as multilayer buckling and lower crustal flow emerge, which are ignored in the thin-sheet model but dominate the deformation style in the 3-D model within a range of a few hundreds of kilometres around the collision zone and indenter corner. Differences between the 3-D and thin-sheet model are considerably larger for a power-law viscous than for a linear viscous rheology. Buckling and lower
Integration of 3D photogrammetric outcrop models in the reservoir modelling workflow
NASA Astrophysics Data System (ADS)
Deschamps, Remy; Joseph, Philippe; Lerat, Olivier; Schmitz, Julien; Doligez, Brigitte; Jardin, Anne
2014-05-01
3D technologies are now widely used in geosciences to reconstruct outcrops in 3D. The technology used for the 3D reconstruction is usually based on Lidar, which provides very precise models. Such datasets offer the possibility to build well-constrained outcrop analogue models for reservoir study purposes. The photogrammetry is an alternate methodology which principles are based in determining the geometric properties of an object from photographic pictures taken from different angles. Outcrop data acquisition is easy, and this methodology allows constructing 3D outcrop models with many advantages such as: - light and fast acquisition, - moderate processing time (depending on the size of the area of interest), - integration of field data and 3D outcrops into the reservoir modelling tools. Whatever the method, the advantages of digital outcrop model are numerous as already highlighted by Hodgetts (2013), McCaffrey et al. (2005) and Pringle et al. (2006): collection of data from otherwise inaccessible areas, access to different angles of view, increase of the possible measurements, attributes analysis, fast rate of data collection, and of course training and communication. This paper proposes a workflow where 3D geocellular models are built by integrating all sources of information from outcrops (surface picking, sedimentological sections, structural and sedimentary dips…). The 3D geomodels that are reconstructed can be used at the reservoir scale, in order to compare the outcrop information with subsurface models: the detailed facies models of the outcrops are transferred into petrophysical and acoustic models, which are used to test different scenarios of seismic and fluid flow modelling. The detailed 3D models are also used to test new techniques of static reservoir modelling, based either on geostatistical approaches or on deterministic (process-based) simulation techniques. A modelling workflow has been designed to model reservoir geometries and properties from
3D time dependent thermo-fluid dynamic model of ground deformation at Campi Flegrei caldera
NASA Astrophysics Data System (ADS)
Castaldo, R.; Tizzani, P.; Manconi, A.; Manzo, M.; Pepe, S.; Pepe, A.; Lanari, R.
2012-04-01
In active volcanic areas deformation signals are generally characterized by non-linear spatial and temporal variations [Tizzani P. et al., 2007]. This behaviour has been revealed in the last two decades by the so-called advanced DInSAR processing algorithms, developed to analyze surface deformation phenomena [Berardino P. et al., 2002; Ferretti C. et al., 2001]. Notwithstanding, most of the inverse modelling attempts to characterize the evolution of the volcanic sources are based on the assumption that the Earth's crust behaves as a homogeneous linear elastic material. However, the behaviour of the upper lithosphere in thermally anomalous regions (as active volcanoes are) might be well described as a non-Newtonian fluid, where some of the material proprieties of the rocks (i.e., apparent viscosities) can change over time [Pinkerton H. et al., 1995]. In this context, we considered the thermal proprieties and mechanical heterogeneities of the upper crust in order to develop a new 3D time dependent thermo-fluid dynamic model of Campi Flegrei (CF) caldera, Southern Italy. More specifically, according to Tizzani P. et al. (2010), we integrated in a FEM environment geophysical information (gravimetric, seismic, and borehole data) available for the considered area and performed two FEM optimization procedures to constrain the 3D distribution of unknown physical parameters (temperature and viscosity distributions) that might help explaining the data observed at surface (geothermal wells and DInSAR measurements). First, we searched for the heat production, the volume source distribution and surface emissivity parameters providing the best-fit of the geothermal profiles data measured at six boreholes [Agip ESGE, 1986], by solving the Fourier heat equation over time (about 40 kys). The 3D thermal field resulting from this optimization was used to calculate the 3D brittle-ductile transition. This analysis revealed the presence of a ductile region, located beneath the centre of
Intriligator, Devrie S.; Detman, Thomas; Fry, Craig D.; Sun Wei; Deehr, Charles; Intriligator, James
2005-08-01
A first-generation 3D kinematic, space weather forecasting solar wind model (HAFv2) has been used to show the importance of solar generated disturbances in Voyager 1 and Voyager 2 observations in the outer heliosphere. We extend this work by using a 3D MHD model (HHMS) that, like HAFv2, incorporates a global, pre-event, inhomogeneous, background solar wind plasma and interplanetary magnetic field. Initial comparisons are made between the two models of the solar wind out to 6 AU and with in-situ observations at the ACE spacecraft before and after the October/November 2003 solar events.
[3-D endocardial surface modelling based on the convex hull algorithm].
Lu, Ying; Xi, Ri-hui; Shen, Hai-dong; Ye, You-li; Zhang, Yong
2006-11-01
In this paper, a method based on the convex hull algorithm is presented for extracting modelling data from the locations of catheter electrodes within a cardiac chamber, so as to create a 3-D model of the heart chamber during diastole and to obtain a good result in the 3-D reconstruction of the chamber based on VTK.
Rethinking Design Process: Using 3D Digital Models as an Interface in Collaborative Session
ERIC Educational Resources Information Center
Ding, Suining
2008-01-01
This paper describes a pilot study for an alternative design process by integrating a designer-user collaborative session with digital models. The collaborative session took place in a 3D AutoCAD class for a real world project. The 3D models served as an interface for designer-user collaboration during the design process. Students not only learned…
3D Modeling from Multi-views Images for Cultural Heritage in Wat-Pho, Thailand
NASA Astrophysics Data System (ADS)
Soontranon, N.; Srestasathiern, P.; Lawawirojwong, S.
2015-08-01
In Thailand, there are several types of (tangible) cultural heritages. This work focuses on 3D modeling of the heritage objects from multi-views images. The images are acquired by using a DSLR camera which costs around 1,500 (camera and lens). Comparing with a 3D laser scanner, the camera is cheaper and lighter than the 3D scanner. Hence, the camera is available for public users and convenient for accessing narrow areas. The acquired images consist of various sculptures and architectures in Wat-Pho which is a Buddhist temple located behind the Grand Palace (Bangkok, Thailand). Wat-Pho is known as temple of the reclining Buddha and the birthplace of traditional Thai massage. To compute the 3D models, a diagram is separated into following steps; Data acquisition, Image matching, Image calibration and orientation, Dense matching and Point cloud processing. For the initial work, small heritages less than 3 meters height are considered for the experimental results. A set of multi-views images of an interested object is used as input data for 3D modeling. In our experiments, 3D models are obtained from MICMAC (open source) software developed by IGN, France. The output of 3D models will be represented by using standard formats of 3D point clouds and triangulated surfaces such as .ply, .off, .obj, etc. To compute for the efficient 3D models, post-processing techniques are required for the final results e.g. noise reduction, surface simplification and reconstruction. The reconstructed 3D models can be provided for public access such as website, DVD, printed materials. The high accurate 3D models can also be used as reference data of the heritage objects that must be restored due to deterioration of a lifetime, natural disasters, etc.
3-D Geometric Modeling for the 21st Century.
ERIC Educational Resources Information Center
Ault, Holly K.
1999-01-01
Describes new geometric computer models used in contemporary computer-aided design (CAD) software including wire frame, surface, solid, and parametric models. Reviews their use in engineering design and discusses the impact of these new technologies on the engineering design graphics curriculum. (Author/CCM)
Computational 3-D Model of the Human Respiratory System
We are developing a comprehensive, morphologically-realistic computational model of the human respiratory system that can be used to study the inhalation, deposition, and clearance of contaminants, while being adaptable for age, race, gender, and health/disease status. The model ...
A topological framework for interactive queries on 3D models in the Web.
Figueiredo, Mauro; Rodrigues, José I; Silvestre, Ivo; Veiga-Pires, Cristina
2014-01-01
Several technologies exist to create 3D content for the web. With X3D, WebGL, and X3DOM, it is possible to visualize and interact with 3D models in a web browser. Frequently, three-dimensional objects are stored using the X3D file format for the web. However, there is no explicit topological information, which makes it difficult to design fast algorithms for applications that require adjacency and incidence data. This paper presents a new open source toolkit TopTri (Topological model for Triangle meshes) for Web3D servers that builds the topological model for triangular meshes of manifold or nonmanifold models. Web3D client applications using this toolkit make queries to the web server to get adjacent and incidence information of vertices, edges, and faces. This paper shows the application of the topological information to get minimal local points and iso-lines in a 3D mesh in a web browser. As an application, we present also the interactive identification of stalactites in a cave chamber in a 3D web browser. Several tests show that even for large triangular meshes with millions of triangles, the adjacency and incidence information is returned in real time making the presented toolkit appropriate for interactive Web3D applications.
Modeling resistive wall modes and disruptive instabilities with M3D-C1
NASA Astrophysics Data System (ADS)
Ferraro, Nm; Jardin, Sc; Pfefferle, D.
2016-10-01
Disruptive instabilities pose a significant challenge to the tokamak approach to magnetic fusion energy, and must be reliably avoided in a successful reactor. These instabilities generally involve rapid, global changes to the magnetic field, and electromagnetic interaction with surrounding conducting structures. Here we apply the extended-MHD code M3D-C1 to calculate the stability and evolution of disruptive modes, including their interaction with external conducting structures. The M3D-C1 model includes the effects of resistivity, equilibrium rotation, and resistive walls of arbitrary thickness, each of which may play important roles in the stability and evolution of disruptive modes. The strong stabilizing effect of rotation on resistive wall modes is explored and compared with analytic theory. The nonlinear evolution of vertical displacement events is also considered, including the evolution of non-axisymmetric instabilities that may arise during the current-quench phase of the disruption. It is found that the non-axisymmetric stability of the plasma during a VDE depends strongly on the thermal history of the plasma. This work is supported by US DOE Grant DE-AC02-09CH11466 and the SciDAC Center for Extended MHD Modeling.
ERIC Educational Resources Information Center
Lim, Kah Heng Alexander; Loo, Zhou Yaw; Goldie, Stephen J.; Adams, Justin W.; McMenamin, Paul G.
2016-01-01
Three-dimensional (3D) printing is an emerging technology capable of readily producing accurate anatomical models, however, evidence for the use of 3D prints in medical education remains limited. A study was performed to assess their effectiveness against cadaveric materials for learning external cardiac anatomy. A double blind randomized…
NASA Astrophysics Data System (ADS)
Docchio, F.; Sansoni, G.; Trebeschi, M.
2005-06-01
This paper presents the activity carried out to perform the three-dimensional acquisition of the "Vittoria Alata", a 2m-high, bronze statue, symbol of our City, located at the Civici Musei di Arte e Storia (S. Giulia) of Brescia. The acquisition of the statue has been performed by using a three-dimensional vision system based on active triangulation and on the projection of non-coherent light. This system, called OPL-3D, represents one of the research products of our Laboratory, which has been active for years in the development of techniques and systems for the contactless acquisition of free-form, complex shapes. The study, originally motivated by the need to explore a new hypothesis on the origin of the "Vittoria Alata", led to its complete digitization and description in terms of both polygonal and NURBS-based models. A suite of copies of the whole statue has been obtained in the framework of the collaboration between the City Museum and the EOS Electro Optical Systems GmbH, located in Munich, Germany. As a first step, one 30 cm-high replica of the whole statue has been produced using a low-resolution triangle model of the statue (3.5 millions of triangles). As a second step, two 1:1 scale copies of the statue have been produced. For them, the Laboratory has provided the high resolution STL file (16 millions of triangles). The paper discusses in detail the hardware and the software facilities used to implement the whole process, and gives a comprehensive description of the results.
Assessing a 3D smoothed seismicity model of induced earthquakes
NASA Astrophysics Data System (ADS)
Zechar, Jeremy; Király, Eszter; Gischig, Valentin; Wiemer, Stefan
2016-04-01
As more energy exploration and extraction efforts cause earthquakes, it becomes increasingly important to control induced seismicity. Risk management schemes must be improved and should ultimately be based on near-real-time forecasting systems. With this goal in mind, we propose a test bench to evaluate models of induced seismicity based on metrics developed by the CSEP community. To illustrate the test bench, we consider a model based on the so-called seismogenic index and a rate decay; to produce three-dimensional forecasts, we smooth past earthquakes in space and time. We explore four variants of this model using the Basel 2006 and Soultz-sous-Forêts 2004 datasets to make short-term forecasts, test their consistency, and rank the model variants. Our results suggest that such a smoothed seismicity model is useful for forecasting induced seismicity within three days, and giving more weight to recent events improves forecast performance. Moreover, the location of the largest induced earthquake is forecast well by this model. Despite the good spatial performance, the model does not estimate the seismicity rate well: it frequently overestimates during stimulation and during the early post-stimulation period, and it systematically underestimates around shut-in. In this presentation, we also describe a robust estimate of information gain, a modification that can also benefit forecast experiments involving tectonic earthquakes.
Constructing stable 3D hydrodynamical models of giant stars
NASA Astrophysics Data System (ADS)
Ohlmann, Sebastian T.; Röpke, Friedrich K.; Pakmor, Rüdiger; Springel, Volker
2017-02-01
Hydrodynamical simulations of stellar interactions require stable models of stars as initial conditions. Such initial models, however, are difficult to construct for giant stars because of the wide range in spatial scales of the hydrostatic equilibrium and in dynamical timescales between the core and the envelope of the giant. They are needed for, e.g., modeling the common envelope phase where a giant envelope encompasses both the giant core and a companion star. Here, we present a new method of approximating and reconstructing giant profiles from a stellar evolution code to produce stable models for multi-dimensional hydrodynamical simulations. We determine typical stellar stratification profiles with the one-dimensional stellar evolution code mesa. After an appropriate mapping, hydrodynamical simulations are conducted using the moving-mesh code arepo. The giant profiles are approximated by replacing the core of the giant with a point mass and by constructing a suitable continuation of the profile to the center. Different reconstruction methods are tested that can specifically control the convective behaviour of the model. After mapping to a grid, a relaxation procedure that includes damping of spurious velocities yields stable models in three-dimensional hydrodynamical simulations. Initially convectively stable configurations lead to stable hydrodynamical models while for stratifications that are convectively unstable in the stellar evolution code, simulations recover the convective behaviour of the initial model and show large convective plumes with Mach numbers up to 0.8. Examples are shown for a 2 M⊙ red giant and a 0.67 M⊙ asymptotic giant branch star. A detailed analysis shows that the improved method reliably provides stable models of giant envelopes that can be used as initial conditions for subsequent hydrodynamical simulations of stellar interactions involving giant stars.
Nonlinear Multiscale Modeling of 3D Woven Fiber Composites under Ballistic Loading
2013-07-11
advanced composites like 3D -OWC. On the other hand, a microscale simulation with resolution of individual fiber filament is impractical due to enormous...REPORT Nonlinear Multiscale Modeling of 3D Woven Fiber Composites under Ballistic Loading 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: The objective of...analysis of 3D woven fiber composites under ballistic loading. Since material behavior is determined by its microstructure, it is essential to
Services Oriented Smart City Platform Based On 3d City Model Visualization
NASA Astrophysics Data System (ADS)
Prandi, F.; Soave, M.; Devigili, F.; Andreolli, M.; De Amicis, R.
2014-04-01
The rapid technological evolution, which is characterizing all the disciplines involved within the wide concept of smart cities, is becoming a key factor to trigger true user-driven innovation. However to fully develop the Smart City concept to a wide geographical target, it is required an infrastructure that allows the integration of heterogeneous geographical information and sensor networks into a common technological ground. In this context 3D city models will play an increasingly important role in our daily lives and become an essential part of the modern city information infrastructure (Spatial Data Infrastructure). The work presented in this paper describes an innovative Services Oriented Architecture software platform aimed at providing smartcities services on top of 3D urban models. 3D city models are the basis of many applications and can became the platform for integrating city information within the Smart-Cites context. In particular the paper will investigate how the efficient visualisation of 3D city models using different levels of detail (LODs) is one of the pivotal technological challenge to support Smart-Cities applications. The goal is to provide to the final user realistic and abstract 3D representations of the urban environment and the possibility to interact with a massive amounts of semantic information contained into the geospatial 3D city model. The proposed solution, using OCG standards and a custom service to provide 3D city models, lets the users to consume the services and interact with the 3D model via Web in a more effective way.
Synthesis of image sequences for Korean sign language using 3D shape model
NASA Astrophysics Data System (ADS)
Hong, Mun-Ho; Choi, Chang-Seok; Kim, Chang-Seok; Jeon, Joon-Hyeon
1995-05-01
This paper proposes a method for offering information and realizing communication to the deaf-mute. The deaf-mute communicates with another person by means of sign language, but most people are unfamiliar with it. This method enables to convert text data into the corresponding image sequences for Korean sign language (KSL). Using a general 3D shape model of the upper body leads to generating the 3D motions of KSL. It is necessary to construct the general 3D shape model considering the anatomical structure of the human body. To obtain a personal 3D shape model, this general model is to adjust to the personal base images. Image synthesis for KSL consists of deforming a personal 3D shape model and texture-mapping the personal images onto the deformed model. The 3D motions for KSL have the facial expressions and the 3D movements of the head, trunk, arms and hands and are parameterized for easily deforming the model. These motion parameters of the upper body are extracted from a skilled signer's motion for each KSL and are stored to the database. Editing the parameters according to the inputs of text data yields to generate the image sequences of 3D motions.
3-D Constraint-Based Modeling: Finding Common Themes.
ERIC Educational Resources Information Center
Wiebe, Eric N.
1999-01-01
Uses Shneiderman's Object-Action Interface model along with the engineering design process as a framework for understanding software interface elements. Provides an educational framework from which instructional materials can be developed. (Author/CCM)
Automated mask creation from a 3D model using Faethm.
Schiek, Richard Louis; Schmidt, Rodney Cannon
2007-11-01
We have developed and implemented a method which given a three-dimensional object can infer from topology the two-dimensional masks needed to produce that object with surface micro-machining. The masks produced by this design tool can be generic, process independent masks, or if given process constraints, specific for a target process. This design tool calculates the two-dimensional mask set required to produce a given three-dimensional model by investigating the vertical topology of the model.
Pluto: Modeling of 3-D Atmosphere-Surface Interactions
NASA Astrophysics Data System (ADS)
Michaels, Timothy I.
2015-11-01
Atmosphere-surface interactions on Pluto are of great importance to creating and maintaining the atmospheric variations and heterogeneous surface that have been observed by New Horizons and two decades' prior work. Publicly released images/data from New Horizons contain numerous fascinating surface features and constrasts. Insights into their origin, maintenance, and/or evolution may be gleaned through multidisciplinary climate modeling. Some results from such modeling will be presented, with an emphasis on shorter-timescale interactions.
Computational ocean acoustics: Advances in 3D ocean acoustic modeling
NASA Astrophysics Data System (ADS)
Schmidt, Henrik; Jensen, Finn B.
2012-11-01
The numerical model of ocean acoustic propagation developed in the 1980's are still in widespread use today, and the field of computational ocean acoustics is often considered a mature field. However, the explosive increase in computational power available to the community has created opportunities for modeling phenomena that earlier were beyond reach. Most notably, three-dimensional propagation and scattering problems have been prohibitive computationally, but are now addressed routinely using brute force numerical approaches such as the Finite Element Method, in particular for target scattering problems, where they are being combined with the traditional wave theory propagation models in hybrid modeling frameworks. Also, recent years has seen the development of hybrid approaches coupling oceanographic circulation models with acoustic propagation models, enabling the forecasting of sonar performance uncertainty in dynamic ocean environments. These and other advances made over the last couple of decades support the notion that the field of computational ocean acoustics is far from being mature. [Work supported by the Office of Naval Research, Code 321OA].
3D shape modeling by integration visual and tactile cues
NASA Astrophysics Data System (ADS)
Xiong, Hanwei; Xu, Jun; Xu, Chenxi; Pan, Ming
2015-10-01
With the progress in CAD (Computer Aided Design) systems, many mechanical components can be designed efficiently with high precision. But, such a system is unfit for some organic shapes, for example, a toy. In this paper, an easy way to dealing with such shapes is presented, combing visual perception with tangible interaction. The method is divided into three phases: two tangible interaction phases and one visual reconstruction. In the first tangible phase, a clay model is used to represent the raw shape, and the designer can change the shape intuitively with his hands. Then the raw shape is scanned into a digital volume model through a low cost vision system. In the last tangible phase, a desktop haptic device from SensAble is used to refine the scanned volume model and convert it into a surface model. A physical clay model and a virtual clay mode are all used in this method to deal with the main shape and the details respectively, and the vision system is used to bridge the two tangible phases. The vision reconstruction system is only made of a camera to acquire raw shape through shape from silhouettes method. All of the systems are installed on a single desktop, make it convenient for designers. The vision system details and a design example are presented in the papers.
Ozone Measurements and a 3D Chemical Transport Model
NASA Technical Reports Server (NTRS)
Stolarski, Richard S.; Douglass, Anne R.; Frith, Stacey; Steenrod, Steven; Polansky, Brian
2004-01-01
We have used our three-dimensional chemical transport model (CTM) to calculate the expected reponse of stratospheric composition over the past 30 years to forcing by chlorine and bromine compounds, solar ultraviolet, and volcanic aerosols. The CTM uses off-line winds and temperatures fiom a 50-year run of the finite volume general circulation model (FVGCM). We compare the total column ozone and the ozone profile fiom the CTM output to a variety of data sources. These include a merged total ozone data set from TOMS and SBUV using the new version 8 algorithm. Total ozone fiom the CTM are compared to ground-station measurements of total ozone at specific locations. Ozone profiles are compared to satellite meausrements fiom SBUV, SAGE, and HALOE. Profiles are also compared to ozonesondes over several locations. The results of the comparisons are quantified by using a time-series statistical analysis to determine trends, solar cycle, and volcanic reponse in both the model and in the data. Initial results indicate that the model responds to forcings in a way that is similar to the observed atmospheric response. The model does seem to be more sensitive to the chlorine and bromine perturbation ihan is the data. Further details and comparisons wiii be discussed.
A Cartesian scheme for compressible multimaterial models in 3D
NASA Astrophysics Data System (ADS)
de Brauer, Alexia; Iollo, Angelo; Milcent, Thomas
2016-05-01
We model the three-dimensional interaction of compressible materials separated by sharp interfaces. We simulate fluid and hyperelastic solid flows in a fully Eulerian framework. The scheme is the same for all materials and can handle large deformations and frictionless contacts. Necessary conditions for hyperbolicity of the hyperelastic neohookean model in three dimensions are proved thanks to an explicit computation of the characteristic speeds. We present stiff multimaterial interactions including air-helium and water-air shock interactions, projectile-shield impacts in air and rebounds.
Synthetic 3D modeling of active regions and simulation of their multi-wavelength emission
NASA Astrophysics Data System (ADS)
Nita, Gelu M.; Fleishman, Gregory; Kuznetsov, Alexey A.; Loukitcheva, Maria A.; Viall, Nicholeen M.; Klimchuk, James A.; Gary, Dale E.
2015-04-01
To facilitate the study of solar active regions, we have created a synthetic modeling framework that combines 3D magnetic structures obtained from magnetic extrapolations with simplified 1D thermal models of the chromosphere, transition region, and corona. To handle, visualize, and use such synthetic data cubes to compute multi-wavelength emission maps and compare them with observations, we have undertaken a major enhancement of our simulation tools, GX_Simulator (ftp://sohoftp.nascom.nasa.gov/solarsoft/packages/gx_simulator/), developed earlier for modeling emission from flaring loops. The greatly enhanced, object-based architecture, which now runs on Windows, Mac, and UNIX platform, offers important new capabilities that include the ability to either import 3D density and temperature distribution models, or to assign to each individual voxel numerically defined coronal or chromospheric temperature and densities, or coronal Differential Emission Measure distributions. Due to these new capabilities, the GX_Simulator can now apply parametric heating models involving average properties of the magnetic field lines crossing a given voxel volume, as well as compute and investigate the spatial and spectral properties of radio (to be compared with VLA or EOVSA data), (sub-)millimeter (ALMA), EUV (AIA/SDO), and X-ray (RHESSI) emission calculated from the model. The application integrates shared-object libraries containing fast free-free, gyrosynchrotron, and gyroresonance emission codes developed in FORTRAN and C++, and soft and hard X-ray and EUV codes developed in IDL. We use this tool to model and analyze an active region and compare the synthetic emission maps obtained in different wavelengths with observations.This work was partially supported by NSF grants AGS-1250374, AGS-1262772, NASA grant NNX14AC87G, the Marie Curie International Research Staff Exchange Scheme "Radiosun" (PEOPLE-2011-IRSES-295272), RFBR grants 14-02-91157, 15-02-01089, 15-02-03717, 15
Thermomechanical effects on permeability for a 3-D model of YM rock
Berge, P A; Blair, S C; Wang, H F
1999-01-12
The authors estimate how thermomechanical processes affect the spatial variability of fracture permeability for a 3-D model representing Topopah Spring tuff at the nuclear-waste repository horizon in Yucca Mountain, Nevada. Using a finite-difference code, they compute thermal stress changes. They evaluate possible permeability enhancement resulting from shear slip along various mapped fracture sets after 50 years of heating, for rock in the near-field environment of the proposed repository. The results indicate permeability enhancement of a factor of 2 for regions about 10 to 30 m above drifts, for north-south striking vertical fractures. Shear slip and permeability increases of a factor of 4 can occur in regions just above drifts, for east-west striking vertical fractures. Information on how permeability may change over the lifetime of a geologic repository is important to the prediction and evaluation of repository performance.
3D modelling of stellar auroral radio emission
NASA Astrophysics Data System (ADS)
Leto, P.; Trigilio, C.; Buemi, C. S.; Umana, G.; Ingallinera, A.; Cerrigone, L.
2016-06-01
The electron cyclotron maser is the coherent emission process that gives rise to the radio lighthouse effect observed in the hot magnetic chemically peculiar star CU Virginis. It has also been proposed to explain the highly circularly polarized radio pulses observed in some ultracool dwarfs with spectral type earlier than M7. Coherent events of this kind resemble auroral radio emission from the magnetized planets of the Solar system. In this article, we present a three-dimensional model able to simulate the timing and profile of the pulses emitted by those stars characterized by a dipolar magnetic field by following the hypothesis of the laminar source model, used to explain the beaming of terrestrial auroral kilometric radiation. This model proves to be a powerful tool with which to understand the auroral radio emission phenomenon, allowing us to derive some general conclusions about the effects of the model's free parameters on the features of coherent pulses and to learn more about the detectability of such pulsed radio emission.
3-D modelling of glacier calving processes (Invited)
NASA Astrophysics Data System (ADS)
Navarro, F. J.
2010-12-01
Calving from tidewater glacier tongues and ice shelves is an important mass loss mechanism for many mid- and high-latitude tidewater glaciers, ice caps and ice sheets, yet an adequate representation of calving is still missing from prognostic models of ice dynamics. Benn and others (2007) proposed a calving criterion appropriate for both grounded and floating glacier tongues or ice shelves. This criterion assumes that the calving is triggered by the downward propagation of transverse surface crevasses, near the calving front, as a result of the extensional stress regime. The crevasse depth is calculated following Nye (1957), assuming that the base of a field of closely spaced crevasses lies at a depth where the longitudinal tensile strain rate tending to open the crevasse equals the creep closure resulting from the ice overburden pressure. Crevasses partially or totally filled with water will penetrate deeper, because of the contribution of water pressure to the opening of the crevasse. This criterion is readily incorporated into glacier and ice sheet models, but has not been fully validated with observations. We apply a three-dimensional extension of Benn and others’ (2007) criterion, incorporated into a full-Stokes model of glacier dynamics, to estimate the current position of the calving front of Johnsons Glacier, Antarctica. The record of the front positions of Johnsons Glacier spans only a few years during the last decade, and during this observation period the front has remained at a nearly constant position, so a full modelling exercise of time evolution to follow the front-position changes of the glacier has not been possible. Instead, our modelling experiment is a diagnostic one, aimed at establishing whether the model adequately reproduces the current front position of Johnsons Glacier (Otero et al., 2010). We develop four experiments: (i) an straightforward three-dimensional extension of Benn and other’s (2007) model; (ii) an improvement to the
Construction of 3-D Terrain Models from BIG Data Sets
2014-05-14
support for dynamically updating the model using the submitted corrections, and using periodic re- computations though an automated system for managing the...NUMBER Pankaj Agarwal Pankaj K. Agarwal, Thomas Moelhave 665502 c. THIS PAGE The public reporting burden for this collection of information is estimated...needed, and completing and reviewing the collection of information . Send comments regarding this burden estimate or any other aspect of this collection
Multiple-Relaxation-Time Lattice Boltzmann Models in 3D
NASA Technical Reports Server (NTRS)
dHumieres, Dominique; Ginzburg, Irina; Krafczyk, Manfred; Lallemand, Pierre; Luo, Li-Shi; Bushnell, Dennis M. (Technical Monitor)
2002-01-01
This article provides a concise exposition of the multiple-relaxation-time lattice Boltzmann equation, with examples of fifteen-velocity and nineteen-velocity models in three dimensions. Simulation of a diagonally lid-driven cavity flow in three dimensions at Re=500 and 2000 is performed. The results clearly demonstrate the superior numerical stability of the multiple-relaxation-time lattice Boltzmann equation over the popular lattice Bhatnagar-Gross-Krook equation.
Some results on hyperscaling in the 3D Ising model
Baker, G.A. Jr.; Kawashima, Naoki
1995-09-01
The authors review exact studies on finite-sized 2 dimensional Ising models and show that the point for an infinite-sized model at the critical temperature is a point of nonuniform approach in the temperature-size plane. They also illuminate some strong effects of finite-size on quantities which do not diverge at the critical point. They then review Monte Carlo studies for 3 dimensional Ising models of various sizes (L = 2--100) at various temperatures. From these results they find that the data for the renormalized coupling constant collapses nicely when plotted against the correlation length, determined in a system of edge length L, divided by L. They also find that {zeta}{sub L}/L {ge} 0.26 is definitely too large for reliable studies of the critical value, g*, of the renormalized coupling constant. They have reasonable evidence that {zeta}{sub L}/L {approx} 0.1 is adequate for results that are within one percent of those for the infinite system size. On this basis, they have conducted a series of Monte Carlo calculations with this condition imposed. These calculations were made practical by the development of improved estimators for use in the Swendsen-Wang cluster method. The authors found from these results, coupled with a reversed limit computation (size increases with the temperature fixed at the critical temperature), that g* > 0, although there may well be a sharp downward drop in g as the critical temperature is approached in accord with the predictions of series analysis. The results support the validity of hyperscaling in the 3 dimensional Ising model.
Kinetic modeling of 3D equilibria in a tokamak
NASA Astrophysics Data System (ADS)
Albert, C. G.; Heyn, M. F.; Kasilov, S. V.; Kernbichler, W.; Martitsch, A. F.; Runov, A. M.
2016-11-01
External resonant magnetic perturbations (RMPs) can modify the magnetic topology in a tokamak. In this case the magnetic field cannot generally be described by ideal MHD equilibrium equations in the vicinity of resonant magnetic surfaces where parallel and perpendicular relaxation timescales are comparable. Usually, resistive MHD models are used to describe these regions. In the present work, a kinetic model is used for this purpose. Within this model, plasma response, current and charge density are computed with help of a Monte Carlo method, where guiding center orbit equations are solved using a semianalytical geometrical integrator. Besides its higher efficiency in comparison to usual integrators this method is not sensitive to noise in field quantities. The computed charges and currents are used to calculate the electromagnetic field with help of a finite element solver. A preconditioned iterative scheme is applied to search for a self-consistent solution. The discussed method is aimed at the nonlinear kinetic description of RMPs in experiments on Edge Localized Mode (ELM) mitigation by external perturbation coil systems without simplification of the device geometry.
3-D model of ICME in the interplanetary medium
NASA Astrophysics Data System (ADS)
Borgazzi, A.; Lara, A.; Niembro, T.
2011-12-01
We developed a method that describes with simply geometry the coordinates of intersection between the leading edge of an ICME and the position of an arbitrary satellite. When a fast CME is ejected from the Sun to the interplanetary space in most of the cases drives a shock. As the CME moves in the corona and later in the interplanetary space more material is stacking in the front and edges of the ejecta. In a first approximation, it is possible to assume the shape of these structures, the CME and the stacked material as a cone of revolution, (the ice-cream model [Schwenn et al., (2005)]). The interface may change due to the interaction of the structure and the non-shocked material in front of the ICME but the original shape of a cone of revolution is preserved. We assume, in a three dimensional geometry, an ice-cream cone shape for the ICME and apply an analytical model for its transport in the interplanetary medium. The goal of the present method is to give the time and the intersection coordinates between the leading edge of the ICME and any satellite that may be in the path of the ICME. With this information we can modelate the travel of the ICME in the interplanetary space using STEREO data.
Introducing a New 3D Dynamical Model for Barred Galaxies
NASA Astrophysics Data System (ADS)
Jung, Christof; Zotos, Euaggelos E.
2015-11-01
The regular or chaotic dynamics of an analytical realistic three dimensional model composed of a spherically symmetric central nucleus, a bar and a flat disk is investigated. For describing the properties of the bar, we introduce a new simple dynamical model and we explore the influence on the character of orbits of all the involved parameters of it, such as the mass and the scale length of the bar, the major semi-axis and the angular velocity of the bar, as well as the energy. Regions of phase space with ordered and chaotic motion are identified in dependence on these parameters and for breaking the rotational symmetry. First, we study in detail the dynamics in the invariant plane z = pz = 0 using the Poincaré map as a basic tool and then study the full three-dimensional case using the Smaller Alignment index method as principal tool for distinguishing between order and chaos. We also present strong evidence obtained through the numerical simulations that our new bar model can realistically describe the formation and the evolution of the observed twin spiral structure in barred galaxies.
The Martian Water Cycle Based on 3-D Modeling
NASA Technical Reports Server (NTRS)
Houben, H.; Haberle, R. M.; Joshi, M. M.
1999-01-01
Understanding the distribution of Martian water is a major goal of the Mars Surveyor program. However, until the bulk of the data from the nominal missions of TES, PMIRR, GRS, MVACS, and the DS2 probes are available, we are bound to be in a state where much of our knowledge of the seasonal behavior of water is based on theoretical modeling. We therefore summarize the results of this modeling at the present time. The most complete calculations come from a somewhat simplified treatment of the Martian climate system which is capable of simulating many decades of weather. More elaborate meteorological models are now being applied to study of the problem. The results show a high degree of consistency with observations of aspects of the Martian water cycle made by Viking MAWD, a large number of ground-based measurements of atmospheric column water vapor, studies of Martian frosts, and the widespread occurrence of water ice clouds. Additional information is contained in the original extended abstract.
3D modeling of geological anomalies based on segmentation of multiattribute fusion
NASA Astrophysics Data System (ADS)
Liu, Zhi-Ning; Song, Cheng-Yun; Li, Zhi-Yong; Cai, Han-Peng; Yao, Xing-Miao; Hu, Guang-Min
2016-09-01
3D modeling of geological bodies based on 3D seismic data is used to define the shape and volume of the bodies, which then can be directly applied to reservoir prediction, reserve estimation, and exploration. However, multiattributes are not effectively used in 3D modeling. To solve this problem, we propose a novel method for building of 3D model of geological anomalies based on the segmentation of multiattribute fusion. First, we divide the seismic attributes into edge- and region-based seismic attributes. Then, the segmentation model incorporating the edge- and region-based models is constructed within the levelset-based framework. Finally, the marching cubes algorithm is adopted to extract the zero level set based on the segmentation results and build the 3D model of the geological anomaly. Combining the edge-and region-based attributes to build the segmentation model, we satisfy the independence requirement and avoid the problem of insufficient data of single seismic attribute in capturing the boundaries of geological anomalies. We apply the proposed method to seismic data from the Sichuan Basin in southwestern China and obtain 3D models of caves and channels. Compared with 3D models obtained based on single seismic attributes, the results are better agreement with reality.
3D Monte Carlo radiation transfer modelling of photodynamic therapy
NASA Astrophysics Data System (ADS)
Campbell, C. Louise; Christison, Craig; Brown, C. Tom A.; Wood, Kenneth; Valentine, Ronan M.; Moseley, Harry
2015-06-01
The effects of ageing and skin type on Photodynamic Therapy (PDT) for different treatment methods have been theoretically investigated. A multilayered Monte Carlo Radiation Transfer model is presented where both daylight activated PDT and conventional PDT are compared. It was found that light penetrates deeper through older skin with a lighter complexion, which translates into a deeper effective treatment depth. The effect of ageing was found to be larger for darker skin types. The investigation further strengthens the usage of daylight as a potential light source for PDT where effective treatment depths of about 2 mm can be achieved.
A 3D Orthotropic Elastic Continuum Damage Material Model
English, Shawn Allen; Brown, Arthur A.
2013-08-01
A three dimensional orthotropic elastic constitutive model with continuum damage is implemented for polymer matrix composite lamina. Damage evolves based on a quadratic homogeneous function of thermodynamic forces in the orthotropic planes. A small strain formulation is used to assess damage. In order to account for large deformations, a Kirchhoff material formulation is implemented and coded for numerical simulation in Sandia’s Sierra Finite Element code suite. The theoretical formulation is described in detail. An example of material parameter determination is given and an example is presented.
Modeling of 3-D Woven Ceramic Matrix Composites
NASA Technical Reports Server (NTRS)
Murthy, Pappu L. N.; Sullivan, Roy M.; Mital, Subodh K.
2003-01-01
Three different approaches are being pursued at the NASA Glenn Research Center to predict the nanostructural behavior of three-dimensional woven ceramic matrix composites. These are: a micromechanics-based approach using W-CEMCAN (Woven Ceramic Matrix Composite Analyzer), a laminate analogy method and a structural frame approach (based on the finite element method). All three techniques are applied to predict the thermomechanical properties of a three-dimensional woven angle interlock C/SiC composite. The properties are predicted for room temperature and 1100 C and the predicted properties are compared to measurements. General observations regarding the three approaches for three-dimensional composite modeling are discussed.
3D Weight Matrices in Modeling Real Estate Prices
NASA Astrophysics Data System (ADS)
Mimis, A.
2016-10-01
Central role in spatial econometric models of real estate data has the definition of the weight matrix by which we capture the spatial dependence between the observations. The weight matrices presented in literature so far, treats space in a two dimensional manner leaving out the effect of the third dimension or in our case the difference in height where the property resides. To overcome this, we propose a new definition of the weight matrix including the third dimensional effect by using the Hadamard product. The results illustrated that the level effect can be absorbed into the new weight matrix.
A 3D Hydrodynamic Model for Cytokinesis of Eukaryotic Cells
2014-08-01
remark that more features can be added to the model by augmenting the corresponding free energy . 2.2 Transport equations for biomass Given the...density for component i, i = 1, 2, 3. For incompress- ible materials, we enforce ϕ1 + ϕ2 + ϕ3 = 1. (2) 2.1 Thermodynamic free energy We denote the domain...in which the cell resides together with the buffer fluid as Ω. The free energy of this mixture system is proposed as follows, F = ∫ Ω fdx, (3) where f
Modeling the diffusion of phosphorus in silicon in 3-D
Baker, K.R.
1994-12-31
The use of matrix preconditioning in semiconductor process simulation is examined. The simplified nonlinear single-species model for the diffusion of phosphorus into silicon is considered. The experimental three-dimensional simulator, PEPPER3, which uses finite differences and the numerical method of lines to implement the reaction-diffusion equation is modified to allow NSPCG to be called to solve the linear system in the inner Newton loop. Use of NSPCG allowed various accelerators such as Generalized Minimal Residual (GMRES) and Conjugate Gradient (CG) to be used in conjunction with preconditioners such as Richardson, Jacobi, and Incomplete Cholesky.
Evaluation of field development plans using 3-D reservoir modelling
Seifert, D.; Lewis, J.J.M.; Newbery, J.D.H.
1997-08-01
Three-dimensional reservoir modelling has become an accepted tool in reservoir description and is used for various purposes, such as reservoir performance prediction or integration and visualisation of data. In this case study, a small Northern North Sea turbiditic reservoir was to be developed with a line drive strategy utilising a series of horizontal producer and injector pairs, oriented north-south. This development plan was to be evaluated and the expected outcome of the wells was to be assessed and risked. Detailed analyses of core, well log and analogue data has led to the development of two geological {open_quotes}end member{close_quotes} scenarios. Both scenarios have been stochastically modelled using the Sequential Indicator Simulation method. The resulting equiprobable realisations have been subjected to detailed statistical well placement optimisation techniques. Based upon bivariate statistical evaluation of more than 1000 numerical well trajectories for each of the two scenarios, it was found that the wells inclinations and lengths had a great impact on the wells success, whereas the azimuth was found to have only a minor impact. After integration of the above results, the actual well paths were redesigned to meet external drilling constraints, resulting in substantial reductions in drilling time and costs.
Lightning Modelling: From 3D to Circuit Approach
NASA Astrophysics Data System (ADS)
Moussa, H.; Abdi, M.; Issac, F.; Prost, D.
2012-05-01
The topic of this study is electromagnetic environment and electromagnetic interferences (EMI) effects, specifically the modelling of lightning indirect effects [1] on aircraft electrical systems present on deported and highly exposed equipments, such as nose landing gear (NLG) and nacelle, through a circuit approach. The main goal of the presented work, funded by a French national project: PREFACE, is to propose a simple equivalent electrical circuit to represent a geometrical structure, taking into account mutual, self inductances, and resistances, which play a fundamental role in the lightning current distribution. Then this model is intended to be coupled to a functional one, describing a power train chain composed of: a converter, a shielded power harness and a motor or a set of resistors used as a load for the converter. The novelty here, is to provide a pre-sizing qualitative approach allowing playing on integration in pre-design phases. This tool intends to offer a user-friendly way for replying rapidly to calls for tender, taking into account the lightning constraints. Two cases are analysed: first, a NLG that is composed of tubular pieces that can be easily approximated by equivalent cylindrical straight conductors. Therefore, passive R, L, M elements of the structure can be extracted through analytical engineer formulas such as those implemented in the partial element equivalent circuit (PEEC) [2] technique. Second, the same approach is intended to be applied on an electrical de-icing nacelle sub-system.
A 3D Current Loop Model of Magnetic Clouds
NASA Astrophysics Data System (ADS)
Chen, James
1992-05-01
A magnetohydrodynamic (MHD) model is developed to study magnetic clouds (Burlaga et al. 1981). In this model, magnetic clouds observed near 1 AU are treated as a consequence of eruptive solar current loops. It is shown that current loops intially in MHD equilibrium can be triggered to rise rapidly, propelling material of up to 10(16) g at up to ~ 1000 km s(-1) and dissipating ~ 10(32) erg of magnetic energy in tens of minutes. The initial rise profile is consistent with observed height-time profiles of erupting filaments (Kahler et al. 1988). Two triggering mechanisms for eruption are suggested: (1)subphotospheric energy storage and trigger and (2) in situ (coronal) energy storage and trigger. In the former, eruption occurs as a result of changes in the subphotospheric magnetic topology and subsequent relaxation to a new equilibrium. In the latter, the current loop can evolve to exceed a local maximum in the magnetic potential associated with the ambient magnetic fields. The former scenario leads to more energetic and longer-lasting eruption than the latter. Burlaga, L. F., Sittler, E., Mariani, F., and Schwenn, R. 1981, J. Geophys. Res., 86, 6673. Kahler, S. W., Moore, R. L., Kane, S. R., and Zirin, H. 1988, Ap. J., 328, 824.
3D modeling and optimization of the ITER ICRH antenna
NASA Astrophysics Data System (ADS)
Louche, F.; Dumortier, P.; Durodié, F.; Messiaen, A.; Maggiora, R.; Milanesio, D.
2011-12-01
The prediction of the coupling properties of the ITER ICRH antenna necessitates the accurate evaluation of the resistance and reactance matrices. The latter are mostly dependent on the geometry of the array and therefore a model as accurate as possible is needed to precisely compute these matrices. Furthermore simulations have so far neglected the poloidal and toroidal profile of the plasma, and it is expected that the loading by individual straps will vary significantly due to varying strap-plasma distance. To take this curvature into account, some modifications of the alignment of the straps with respect to the toroidal direction are proposed. It is shown with CST Microwave Studio® [1] that considering two segments in the toroidal direction, i.e. a "V-shaped" toroidal antenna, is sufficient. A new CATIA model including this segmentation has been drawn and imported into both MWS and TOPICA [2] codes. Simulations show a good agreement of the impedance matrices in vacuum. Various modifications of the geometry are proposed in order to further optimize the coupling. In particular we study the effect of the strap box parameters and the recess of the vertical septa.
Synthetic benchmark for modeling flow in 3D fractured media
NASA Astrophysics Data System (ADS)
de Dreuzy, Jean-Raynald; Pichot, Géraldine; Poirriez, Baptiste; Erhel, Jocelyne
2013-01-01
Intensity and localization of flows in fractured media have promoted the development of a large range of different modeling approaches including Discrete Fracture Networks, pipe networks and equivalent continuous media. While benchmarked usually within site studies, we propose an alternative numerical benchmark based on highly-resolved Discrete Fracture Networks (DFNs) and on a stochastic approach. Test cases are built on fractures of different lengths, orientations, aspect ratios and hydraulic apertures, issuing the broad ranges of topological structures and hydraulic properties classically observed. We present 18 DFN cases, with 10 random simulations by case. These 180 DFN structures are provided and fully documented. They display a representative variety of the configurations that challenge the numerical methods at the different stages of discretization, mesh generation and system solving. Using a previously assessed mixed hybrid finite element method (Erhel et al., 2009a), we systematically provide reference flow and head solutions. Because CPU and memory requirements stem mainly from system solving, we study direct and iterative sparse linear solvers. We show that the most cpu-time efficient method is a direct multifrontal method for small systems, while conjugate gradient preconditioned by algebraic multrigrid is more relevant at larger sizes. Available results can be used further as references for building up alternative numerical and physical models in both directions of improving accuracy and efficiency.
Possibility of reconstruction of dental plaster cast from 3D digital study models
2013-01-01
Objectives To compare traditional plaster casts, digital models and 3D printed copies of dental plaster casts based on various criteria. To determine whether 3D printed copies obtained using open source system RepRap can replace traditional plaster casts in dental practice. To compare and contrast the qualities of two possible 3D printing options – open source system RepRap and commercially available 3D printing. Design and settings A method comparison study on 10 dental plaster casts from the Orthodontic department, Department of Stomatology, 2nd medical Faulty, Charles University Prague, Czech Republic. Material and methods Each of 10 plaster casts were scanned by inEos Blue scanner and the printed on 3D printer RepRap [10 models] and ProJet HD3000 3D printer [1 model]. Linear measurements between selected points on the dental arches of upper and lower jaws on plaster casts and its 3D copy were recorded and statistically analyzed. Results 3D printed copies have many advantages over traditional plaster casts. The precision and accuracy of the RepRap 3D printed copies of plaster casts were confirmed based on the statistical analysis. Although the commercially available 3D printing enables to print more details than the RepRap system, it is expensive and for the purpose of clinical use can be replaced by the cheaper prints obtained from RepRap printed copies. Conclusions Scanning of the traditional plaster casts to obtain a digital model offers a pragmatic approach. The scans can subsequently be used as a template to print the plaster casts as required. Using 3D printers can replace traditional plaster casts primarily due to their accuracy and price. PMID:23721330
Impact of the 3-D model strategy on science learning of the solar system
NASA Astrophysics Data System (ADS)
Alharbi, Mohammed
The purpose of this mixed method study, quantitative and descriptive, was to determine whether the first-middle grade (seventh grade) students at Saudi schools are able to learn and use the Autodesk Maya software to interact and create their own 3-D models and animations and whether their use of the software influences their study habits and their understanding of the school subject matter. The study revealed that there is value to the science students regarding the use of 3-D software to create 3-D models to complete science assignments. Also, this study aimed to address the middle-school students' ability to learn 3-D software in art class, and then ultimately use it in their science class. The success of this study may open the way to consider the impact of 3-D modeling on other school subjects, such as mathematics, art, and geography. When the students start using graphic design, including 3-D software, at a young age, they tend to develop personal creativity and skills. The success of this study, if applied in schools, will provide the community with skillful young designers and increase awareness of graphic design and the new 3-D technology. Experimental method was used to answer the quantitative research question, are there significant differences applying the learning method using 3-D models (no 3-D, premade 3-D, and create 3-D) in a science class being taught about the solar system and its impact on the students' science achievement scores? Descriptive method was used to answer the qualitative research questions that are about the difficulty of learning and using Autodesk Maya software, time that students take to use the basic levels of Polygon and Animation parts of the Autodesk Maya software, and level of students' work quality.
Evolution of 3-D geologic framework modeling and its application to groundwater flow studies
Blome, Charles D.; Smith, David V.
2012-01-01
In this Fact Sheet, the authors discuss the evolution of project 3-D subsurface framework modeling, research in hydrostratigraphy and airborne geophysics, and methodologies used to link geologic and groundwater flow models.
Extracting Feature Points of the Human Body Using the Model of a 3D Human Body
NASA Astrophysics Data System (ADS)
Shin, Jeongeun; Ozawa, Shinji
The purpose of this research is to recognize 3D shape features of a human body automatically using a 3D laser-scanning machine. In order to recognize the 3D shape features, we selected the 23 feature points of a body and modeled its 3D features. The set of 23 feature points consists of the motion axis of a joint, the main point for the bone structure of a human body. For extracting feature points of object model, we made 2.5D templates neighbor for each feature points were extracted according to the feature points of the standard model of human body. And the feature points were extracted by the template matching. The extracted feature points can be applied as body measurement, the 3D virtual fitting system for apparel etc.
Modeling electromagnetic rail launchers at speed using 3D finite elements
Rodger, D.; Leonard, P.J.; Eastham, J.F. )
1991-01-01
In this paper a new finite element technique for modelling 3D transient eddy currents in moving conductors is described. This has been implemented in the MEGA software package for 2 and 3D electromagnetic field analysis. The application of the technique to railgun launchers is illustrated.
RETRAN-3D MOD003 Peach Bottom Turbine Trip 2 Multidimensional Kinetics Analysis Models and Results
Mori, Michitsugu; Ogura, Katsunori; Gose, Garry C.; Wu, J.-Y
2003-04-15
An analysis of the Peach Bottom Unit 2 Turbine Trip Test 2 (PB2/TT2) has been performed using RETRAN-3D MOD003. The purpose of the analysis was to investigate the PB2/TT2 overpressurization transient using the RETRAN-3D multidimensional kinetics model.
Modeling and analysis of 3-D elongated shapes with applications to long bone morphometry
Burdin, V.; Roux, C.; Lefevre, C.; Stindel, E.
1996-02-01
This paper presents a geometric model to be used as a framework for the description and analysis of three-dimensional (3-D) elongated shapes. Elongated shapes can be decomposed into two different parts: a 3-D curve (the central axis) and a 3-D surface (the straight surface). The central axis is described in terms of curvature and torsion. A novel concept of torsion image is introduced which allows the user to study the torsion of some relevant 3-D structures such as the medulla of long bones, without computing the third derivative. The description of the straight surface is based on an ordered set of Fourier Descriptors (FD`s), each set representing a 2-D slice of the structure. These descriptors possess completeness, continuity, and stability properties, and some geometrical invariancies. A polar diagram is built which contains the anatomical information of the straight surface and can be used as a tool for the analysis and discrimination of 3-D structures. A technique for the reconstruction of the 3-D surface from the model`s two components is presented. Various applications to the analysis of long bone structures, such as the ulna and radius, are derived from the model, namely, data compression, comparison of 3-D shapes, segmentation into 3-D primitives, and torsion and curvature analysis. The relevance of the method to morphometry and to clinical applications is discussed.
Development of 3D electromagnetic modeling tools for airborne vehicles
NASA Technical Reports Server (NTRS)
Volakis, John L.
1992-01-01
The main goal of this project is to develop methodologies for scattering by airborne composite vehicles. Although our primary focus continues to be the development of a general purpose code for analyzing the entire structure as a single unit, a number of other tasks are also pursued in parallel with this effort. These tasks are important in testing the overall approach and in developing suitable models for materials coatings, junctions and, more generally, in assessing the effectiveness of the various parts comprising the final code. Here, we briefly discuss our progress on the five different tasks which were pursued during this period. Our progress on each of these tasks is described in the detailed reports (listed at the end of this report) and the memoranda included. The first task described below is, of course, the core of this project and deals with the development of the overall code. Undoubtedly, it is the outcome of the research which was funded by NASA-Ames and the Navy over the past three years. During this year we developed the first finite element code for scattering by structures of arbitrary shape and composition. The code employs a new absorbing boundary condition which allows termination of the finite element mesh only 0.3 lambda from the outer surface of the target. This leads to a remarkable reduction of the mesh size and is a unique feature of the code. Other unique features of this code include capabilities to model resistive sheets, impedance sheets and anisotropic materials. This last capability is the latest feature of the code and is still under development. The code has been extensively validated for a number of composite geometries and some examples are given. The validation of the code is still in progress for anisotropic and larger non-metallic geometries and cavities. The developed finite element code is based on a Galerkin's formulation and employs edge-based tetrahedral elements for discretizing the dielectric sections and the region
Virtual 3D Modeling of Airways in Congenital Heart Defects.
Speggiorin, Simone; Durairaj, Saravanan; Mimic, Branko; Corno, Antonio F
2016-01-01
The involvement of the airway is not uncommon in the presence of complex cardiovascular malformations. In these cases, a careful inspection of the relationship between the airway and the vasculature is paramount to plan the surgical procedure. Three-dimensional printing enhanced the visualization of the cardiovascular structure. Unfortunately, IT does not allow to remove selected anatomy to improve the visualization of the surrounding ones. Computerized modeling has the potential to fill this gap by allowing a dynamic handling of different anatomies, increasing the exposure of vessels or bronchi to show their relationship. We started to use this technique to plan the surgical repair in these complex cases where the airway is affected. This technique is routinely used in our Institution as an additional tool in the presurgical assessment. We report four cases in which the airways were compressed by vascular structures - ascending aorta in one, left pulmonary artery sling in one, patent ductus arteriosus in one, and major aorto-pulmonary collateral artery in one. We believe this technique can enhance the understanding of the causes of airway involvement and facilitate the creation of an appropriate surgical plan.
Virtual 3D Modeling of Airways in Congenital Heart Defects
Speggiorin, Simone; Durairaj, Saravanan; Mimic, Branko; Corno, Antonio F.
2016-01-01
The involvement of the airway is not uncommon in the presence of complex cardiovascular malformations. In these cases, a careful inspection of the relationship between the airway and the vasculature is paramount to plan the surgical procedure. Three-dimensional printing enhanced the visualization of the cardiovascular structure. Unfortunately, IT does not allow to remove selected anatomy to improve the visualization of the surrounding ones. Computerized modeling has the potential to fill this gap by allowing a dynamic handling of different anatomies, increasing the exposure of vessels or bronchi to show their relationship. We started to use this technique to plan the surgical repair in these complex cases where the airway is affected. This technique is routinely used in our Institution as an additional tool in the presurgical assessment. We report four cases in which the airways were compressed by vascular structures – ascending aorta in one, left pulmonary artery sling in one, patent ductus arteriosus in one, and major aorto-pulmonary collateral artery in one. We believe this technique can enhance the understanding of the causes of airway involvement and facilitate the creation of an appropriate surgical plan. PMID:27833903
Modeling of Localized Neutral Particle Sources in 3D Edge Plasmas
Umansky, M V; Rognlien, T D; Fenstermacher, M E; Borchardt, M; Mutzke, A; Riemann, J; Schneider, R; Owen, L W
2002-05-23
A new edge plasma code BoRiS [1] has a fully 3D fluid plasma model. We supplement BoRiS with a 3D fluid neutral model including equations for parallel momentum and collisional perpendicular diffusion. This makes BoRiS an integrated plasma-neutral model suitable for a variety of applications. We present modeling results for a localized gas source in the geometry of the NCSX stellarator.
3D Integrated geophysical-petrological modelling of the Iranian lithosphere
NASA Astrophysics Data System (ADS)
Mousavi, Naeim; Ardestani, Vahid E.; Ebbing, Jörg; Fullea, Javier
2016-04-01
The present-day Iranian Plateau is the result of complex tectonic processes associated with the Arabia-Eurasia Plate convergence at a lithospheric scale. In spite of previous mostly 2D geophysical studies, fundamental questions regarding the deep lithospheric and sub-lithospheric structure beneath Iran remain open. A robust 3D model of the thermochemical lithospheric structure in Iran is an important step toward a better understanding of the geological history and tectonic events in the area. Here, we apply a combined geophysical-petrological methodology (LitMod3D) to investigate the present-day thermal and compositional structure in the crust and upper mantle beneath the Arabia-Eurasia collision zone using a comprehensive variety of constraining data: elevation, surface heat flow, gravity potential fields, satellite gravity gradients, xenoliths and seismic tomography. Different mantle compositions were tested in our model based on local xenolith samples and global data base averages for different tectonothermal ages. A uniform mantle composition fails to explain the observed gravity field, gravity gradients and surface topography. A tectonically regionalized lithospheric mantle compositional model is able to explain all data sets including seismic tomography models. Our preliminary thermochemical lithospheric study constrains the depth to Moho discontinuity and intra crustal geometries including depth to sediments. We also determine the depth to Curie isotherm which is known as the base of magnetized crustal/uppermost mantle bodies. Discrepancies with respect to previous studies include mantle composition and the geometry of Moho and Lithosphere-Asthenosphere Boundary (LAB). Synthetic seismic Vs and Vp velocities match existing seismic tomography models in the area. In this study, depleted mantle compositions are modelled beneath cold and thick lithosphere in Arabian and Turan platforms. A more fertile mantle composition is found in collision zones. Based on our 3
On Fundamental Evaluation Using Uav Imagery and 3d Modeling Software
NASA Astrophysics Data System (ADS)
Nakano, K.; Suzuki, H.; Tamino, T.; Chikatsu, H.
2016-06-01
Unmanned aerial vehicles (UAVs), which have been widely used in recent years, can acquire high-resolution images with resolutions in millimeters; such images cannot be acquired with manned aircrafts. Moreover, it has become possible to obtain a surface reconstruction of a realistic 3D model using high-overlap images and 3D modeling software such as Context capture, Pix4Dmapper, Photoscan based on computer vision technology such as structure from motion and multi-view stereo. 3D modeling software has many applications. However, most of them seem to not have obtained appropriate accuracy control in accordance with the knowledge of photogrammetry and/or computer vision. Therefore, we performed flight tests in a test field using an UAV equipped with a gimbal stabilizer and consumer grade digital camera. Our UAV is a hexacopter and can fly according to the waypoints for autonomous flight and can record flight logs. We acquired images from different altitudes such as 10 m, 20 m, and 30 m. We obtained 3D reconstruction results of orthoimages, point clouds, and textured TIN models for accuracy evaluation in some cases with different image scale conditions using 3D modeling software. Moreover, the accuracy aspect was evaluated for different units of input image—course unit and flight unit. This paper describes the fundamental accuracy evaluation for 3D modeling using UAV imagery and 3D modeling software from the viewpoint of close-range photogrammetry.
Investigating the Paleoproterozoic glaciations with 3-D climate modeling
NASA Astrophysics Data System (ADS)
Teitler, Yoram; Le Hir, Guillaume; Fluteau, Frédéric; Philippot, Pascal; Donnadieu, Yannick
2014-06-01
It is generally assumed that the Earth's surface was warm during most of its early history but that significant cooling occurred between 2.45 and 2.22 Ga leading to the first global and cyclical glacial epoch. This onset of snowball Earth conditions was coeval with a large pulse of oxygenation that permanently oxygenated the atmosphere and shallow oceans (Great Oxygenation Event, GOE), though it is not known whether one influenced the other or if they were independent events. Hereafter we used a General Circulation climate Model (GCM) to estimate the partial pressures of atmospheric CO2 (pCO2) and CH4 (pCH4) required to account for the onset of snowball Earth conditions during the Paleoproterozoic. We show that Earth's surface can be maintained in an ice-free state under atmospheric CO2 concentrations lower than 2.6×10-2 bar without invoking the need of high CH4 concentrations. Assuming that the cooling of the Earth's surface is related to the collapse of atmospheric greenhouse gases, we tested the relevance of different scenarios including (i) the collapse of pCH4 in response to the GOE and (ii) the drawdown of pCO2 due to both a decrease in volcanic outgassing rate and an increase in global weathering efficiency. We show that the cyclical character of Paleoproterozoic glaciations is best explained by a long-lasted decrease of pCO2. To support this scenario, we examine how the long-term carbon cycle and the equilibrium pCO2 respond to the emplacement of large subaerial basaltic provinces (LIPs) and to a temporary shutdown of volcanism as supported by geologic data. We show that the sink of pCO2 through silicate weathering is limited by the absence of terrestrial higher plants. In such conditions, the equilibrium pCO2 remains high enough to preclude the onset of snowball conditions regardless the intensity of the pCH4 collapse. The combination of an increase in weathering efficiency and a decrease in volcanic outgassing rate can significantly reduce the
3D MODEL ATMOSPHERES FOR EXTREMELY LOW-MASS WHITE DWARFS
Tremblay, P.-E.; Gianninas, A.; Kilic, M.; Ludwig, H.-G.; Steffen, M.; Freytag, B.; Hermes, J. J.
2015-08-20
We present an extended grid of mean three-dimensional (3D) spectra for low-mass, pure-hydrogen atmosphere DA white dwarfs (WDs). We use CO5BOLD radiation-hydrodynamics 3D simulations covering T{sub eff} = 6000–11,500 K and log g = 5–6.5 (g in cm s{sup −2}) to derive analytical functions to convert spectroscopically determined 1D temperatures and surface gravities to 3D atmospheric parameters. Along with the previously published 3D models, the 1D to 3D corrections are now available for essentially all known convective DA WDs (i.e., log g = 5–9). For low-mass WDs, the correction in temperature is relatively small (a few percent at the most), but the surface gravities measured from the 3D models are lower by as much as 0.35 dex. We revisit the spectroscopic analysis of the extremely low-mass (ELM) WDs, and demonstrate that the 3D models largely resolve the discrepancies seen in the radius and mass measurements for relatively cool ELM WDs in eclipsing double WD and WD + millisecond pulsar binary systems. We also use the 3D corrections to revise the boundaries of the ZZ Ceti instability strip, including the recently found ELM pulsators.
NASA Astrophysics Data System (ADS)
Samian, R. S.; Abbassi, A.; Ghazanfarian, J.
2013-09-01
The thermal performance of two-dimensional (2D) field-effect transistors (FET) is investigated frequently by solving the Fourier heat diffusion law and the Boltzmann transport equation (BTE). With the introduction of the new generation of 3D FETs in which their thickness is less than the phonon mean-free-path it is necessary to carefully simulate the thermal performance of such devices. This paper numerically integrates the BTE in common 2D transistors including planar single layer and Silicon-On-Insulator (SOI) transistor, and the new generation of 3D transistors including FinFET and Tri-Gate devices. In order to decrease the directional dependency of results in 3D simulations; the Legendre equal-weight (PN-EW) quadrature set has been employed. It is found that if similar switching time is assumed for 3D and 2D FETs while the new generation of 3D FETs has less net energy consumption, they have higher hot-spot temperature. The results show continuous heat flux distribution normal to the silicon/oxide interface while the temperature jump is seen at the interface in double layer transistors.
Extraction of the 3D Free Space from Building Models for Indoor Navigation
NASA Astrophysics Data System (ADS)
Diakité, A. A.; Zlatanova, S.
2016-10-01
For several decades, indoor navigation has been exclusively investigated in a 2D perspective, based on floor plans, projection and other 2D representations of buildings. Nevertheless, 3D representations are closer to our reality and offer a more intuitive description of the space configuration. Thanks to recent advances in 3D modelling, 3D navigation is timidly but increasingly gaining in interest through the indoor applications. But, because the structure of indoor environment is often more complex than outdoor, very simplified models are used and obstacles are not considered for indoor navigation leading to limited possibilities in complex buildings. In this paper we consider the entire configuration of the indoor environment in 3D and introduce a method to extract from it the actual navigable space as a network of connected 3D spaces (volumes). We describe how to construct such 3D free spaces from semantically rich and furnished IFC models. The approach combines the geometric, the topological and the semantic information available in a 3D model to isolate the free space from the rest of the components. Furthermore, the extraction of such navigable spaces in building models lacking of semantic information is also considered. A data structure named combinatorial maps is used to support the operations required by the process while preserving the topological and semantic information of the input models.
A Shell/3D Modeling Technique for the Analysis of Delaminated Composite Laminates
NASA Technical Reports Server (NTRS)
Krueger, Ronald; OBrien, T. Kevin
2000-01-01
A shell/3D modeling technique was developed for which a local solid finite element model is used only in the immediate vicinity of the delamination front. The goal was to combine the accuracy of the full three-dimensional solution with the computational efficiency of a shell finite element model. Multi-point constraints provided a kinematically compatible interface between the local 3D model and the global structural model which has been meshed with shell finite elements. Double Cantilever Beam, End Notched Flexure, and Single Leg Bending specimens were analyzed first using full 3D finite element models to obtain reference solutions. Mixed mode strain energy release rate distributions were computed using the virtual crack closure technique. The analyses were repeated using the shell/3D technique to study the feasibility for pure mode I, mode II and mixed mode I/II cases. Specimens with a unidirectional layup and with a multidirectional layup were simulated. For a local 3D model, extending to a minimum of about three specimen thicknesses on either side of the delamination front, the results were in good agreement with mixed mode strain energy release rates obtained from computations where the entire specimen had been modeled with solid elements. For large built-up composite structures the shell/3D modeling technique offers a great potential for reducing the model size, since only a relatively small section in the vicinity of the delamination front needs to be modeled with solid elements.
Wu, Ai-Min; Wang, Sheng; Weng, Wan-Qing; Shao, Zhen-Xuan; Yang, Xin-Dong; Wang, Jian-Shun; Xu, Hua-Zi; Chi, Yong-Long
2014-12-01
Anterior occiput-to-axis screw fixation is more suitable than a posterior approach for some patients with a history of posterior surgery. The complex osseous anatomy between the occiput and the axis causes a high risk of injury to neurological and vascular structures, and it is important to have an accurate screw trajectory to guide anterior occiput-to-axis screw fixation. Thirty computed tomography (CT) scans of upper cervical spines were obtained for three-dimensional (3D) reconstruction. Cylinders (1.75 mm radius) were drawn to simulate the trajectory of an anterior occiput-to-axis screw. The imitation screw was adjusted to 4 different angles and measured, as were the values of the maximized anteroposterior width and the left-right width of the occiput (C0) to the C1 and C1 to C2 joints. Then, the 3D models were printed, and an angle guide device was used to introduce the screws into the 3