Science.gov

Sample records for 3d spatial distribution

  1. Scalable Multi-Platform Distribution of Spatial 3d Contents

    NASA Astrophysics Data System (ADS)

    Klimke, J.; Hagedorn, B.; Döllner, J.

    2013-09-01

    Virtual 3D city models provide powerful user interfaces for communication of 2D and 3D geoinformation. Providing high quality visualization of massive 3D geoinformation in a scalable, fast, and cost efficient manner is still a challenging task. Especially for mobile and web-based system environments, software and hardware configurations of target systems differ significantly. This makes it hard to provide fast, visually appealing renderings of 3D data throughout a variety of platforms and devices. Current mobile or web-based solutions for 3D visualization usually require raw 3D scene data such as triangle meshes together with textures delivered from server to client, what makes them strongly limited in terms of size and complexity of the models they can handle. In this paper, we introduce a new approach for provisioning of massive, virtual 3D city models on different platforms namely web browsers, smartphones or tablets, by means of an interactive map assembled from artificial oblique image tiles. The key concept is to synthesize such images of a virtual 3D city model by a 3D rendering service in a preprocessing step. This service encapsulates model handling and 3D rendering techniques for high quality visualization of massive 3D models. By generating image tiles using this service, the 3D rendering process is shifted from the client side, which provides major advantages: (a) The complexity of the 3D city model data is decoupled from data transfer complexity (b) the implementation of client applications is simplified significantly as 3D rendering is encapsulated on server side (c) 3D city models can be easily deployed for and used by a large number of concurrent users, leading to a high degree of scalability of the overall approach. All core 3D rendering techniques are performed on a dedicated 3D rendering server, and thin-client applications can be compactly implemented for various devices and platforms.

  2. Quantifying the Effect of 3D Spatial Resolution on the Accuracy of Microstructural Distributions (PREPRINT)

    DTIC Science & Technology

    2012-08-01

    Michael D. Uchic and Michael Groeber Metals Branch Structural Materials Division Megna Shah UES, Inc. Gregory Loughnane, Raghavan Srinivasan...AUTHOR(S) Michael D. Uchic and Michael Groeber (AFRL/RXCM) Megna Shah (UES, Inc.) Gregory Loughnane, Raghavan Srinivasan, and Ramana Grandhi (Wright...effect of 3D spatial resolution on the accuracy of microstructural distributions Gregory Loughnane 1 , Michael Groeber 2 , Michael Uchic 2 , Matthew

  3. Spatial Distribution of Yarns and Mechanical Properties in 3D Braided Tubular Composites

    NASA Astrophysics Data System (ADS)

    Wang, Y. Q.; Wang, A. S. D.

    1997-03-01

    This paper outlines a method which links the following analytically simulated events in sequence: (1) braiding of a 3D preform of tubular cross-section characterized by a set of braiding parameters defining the braiding setup and braiding steps; (2) geometric description of the yarn topology in the braided preform in explicit terms of a set of topological parameters defined by the preform shape and the braiding parameters; (3) description of the exact yarn distribution after preform consolidation with a binding matrix the values of the topological parameters are related to the exterior dimensions and surface features of the consolidated preform; and (4) forecasting the mechanical properties in the final composite via a suitable micromechanics model that takes into account the spatial yarn distribution in the composite and properties of the constituents.

  4. Modeling spatial distribution of oxygen in 3d culture of islet beta-cells.

    PubMed

    McReynolds, John; Wen, Yu; Li, Xiaofei; Guan, Jianjun; Jin, Sha

    2017-01-01

    Three-dimensional (3D) scaffold culture of pancreatic β-cell has been proven to be able to better mimic physiological conditions in the body. However, one critical issue with culturing pancreatic β-cells is that β-cells consume large amounts of oxygen, and hence insufficient oxygen supply in the culture leads to loss of β-cell mass and functions. This becomes more significant when cells are cultured in a 3D scaffold. In this study, in order to understand the effect of oxygen tension inside a cell-laden collagen culture on β-cell proliferation, a culture model with encapsulation of an oxygen-generator was established. The oxygen-generator was made by embedding hydrogen peroxide into nontoxic polydimethylsiloxane to avoid the toxicity of a chemical reaction in the β-cell culture. To examine the effectiveness of the oxygenation enabled 3D culture, the spatial-temporal distribution of oxygen tension inside a scaffold was evaluated by a mathematical modeling approach. Our simulation results indicated that an oxygenation-aided 3D culture would augment the oxygen supply required for the β-cells. Furthermore, we identified that cell seeding density and the capacity of the oxygenator are two critical parameters in the optimization of the culture. Notably, cell-laden scaffold cultures with an in situ oxygen supply significantly improved the β-cells' biological function. These β-cells possess high insulin secretion capacity. The results obtained in this work would provide valuable information for optimizing and encouraging functional β-cell cultures. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:221-228, 2017.

  5. Spatial 3D distribution of soil organic carbon under different land use types.

    PubMed

    Amirian Chakan, A; Taghizadeh-Mehrjardi, R; Kerry, R; Kumar, S; Khordehbin, S; Yusefi Khanghah, S

    2017-03-01

    Soil organic carbon (SOC) has been assessed in three dimension (3D) in several studies, but little is known about the combined effects of land use and soil depth on SOC stocks in semi-arid areas. This paper investigates the 3D distribution of SOC to a depth of 1 m in a 4600-ha area in southeastern Iran with different land uses under the irrigated farming (IF), dry farming (DF), orchards (Or), range plants on the Gachsaran formation (RaG), and range plants on a quaternary formation (RaQ). Predictions were made using the artificial neural networks (ANNs), regression trees (RTs), and spline functions with auxiliary covariates derived from a digital elevation model (DEM), the Landsat 8 imagery, and land use types. Correlation analysis showed that the main predictors for SOC in the topsoil were covariates derived from the imagery; however, for the lower depths, covariates derived from both the DEM and imagery were important. ANNs showed more efficiency than did RTs in predicting SOC. The results showed that 3D distribution of SOC was significantly affected by land use types. SOC stocks of soils under Or and IF were significantly higher than those under DF, RaG, and RaQ. The SOC below 30 cm accounted for about 59% of the total soil stock. Results showed that depth functions combined with digital soil mapping techniques provide a promising approach to evaluate 3D SOC distribution under different land uses in semi-arid regions and could be used to assess changes in time to determine appropriate management strategies.

  6. Integration of GIS, Geostatistics, and 3-D Technology to Assess the Spatial Distribution of Soil Moisture

    NASA Technical Reports Server (NTRS)

    Betts, M.; Tsegaye, T.; Tadesse, W.; Coleman, T. L.; Fahsi, A.

    1998-01-01

    The spatial and temporal distribution of near surface soil moisture is of fundamental importance to many physical, biological, biogeochemical, and hydrological processes. However, knowledge of these space-time dynamics and the processes which control them remains unclear. The integration of geographic information systems (GIS) and geostatistics together promise a simple mechanism to evaluate and display the spatial and temporal distribution of this vital hydrologic and physical variable. Therefore, this research demonstrates the use of geostatistics and GIS to predict and display soil moisture distribution under vegetated and non-vegetated plots. The research was conducted at the Winfred Thomas Agricultural Experiment Station (WTAES), Hazel Green, Alabama. Soil moisture measurement were done on a 10 by 10 m grid from tall fescue grass (GR), alfalfa (AA), bare rough (BR), and bare smooth (BS) plots. Results indicated that variance associated with soil moisture was higher for vegetated plots than non-vegetated plots. The presence of vegetation in general contributed to the spatial variability of soil moisture. Integration of geostatistics and GIS can improve the productivity of farm lands and the precision of farming.

  7. 3D Spatial Distribution of the Intergalactic Medium: The ESO Blues?

    NASA Astrophysics Data System (ADS)

    Rollinde, Emmanuel; Petitjean, Patrick; Pichon, Christophe; Colombi, Stéphane; Aracil, Bastien

    The numerous absorption lines seen in the spectra of distant quasars (the so-called Lyman-α forest) reveal the intergalactic medium (IGM) up to redshifts larger than 5. It is believed that the space distribution of the gas traces the potential wells of the dark matter. Indeed, recent numerical N-body simulations have been successful at reproducing the observed characteristics of the Lyman-α forest (e.g. [1][12][5]). The IGM is therefore seen as a smooth pervasive medium which can be used to study the spatial distribution of the mass on scales larger than the Jeans' length. This idea is reinforced by observations of multiple lines of sight. It is observed that the Lyman-α forest is fairly homogeneous on scale smaller than 100 kpc (e.g. [11]) and highly correlated on scale up to one megaparsec (e.g. [13][3]). The number of suitable multiple lines of sight is small however and the sample need to be significantly enlarged before any firm conclusion can be drawn (see Section 3.3).

  8. On the spatial distribution of seismicity and the 3D tectonic stress field in western Greece

    NASA Astrophysics Data System (ADS)

    Kassaras, Ioannis; Kapetanidis, Vasilis; Karakonstantis, Andreas

    2016-10-01

    We analyzed a large number of focal mechanisms and relocated earthquake hypocenters to investigate the geodynamics of western Greece, the most seismically active part of the Aegean plate-boundary zone. This region was seismically activated multiple times during the last decade, providing a large amount of enhanced quality new information that was obtained by the Hellenic Unified Seismological Network (HUSN). Relocated seismicity using a double-difference method appears to be concentrated above ∼35 km depth, exhibiting spatial continuity along the convergence boundary and being clustered elsewhere. Earthquakes are confined within the accreted sediments escarpment of the down-going African plate against the un-deformed Eurasian hinterland. The data arrangement shows that Pindos constitutes a seismic boundary along which large stress heterogeneities occur. In Cephalonia no seismicity is found to be related with the offshore Cephalonia Transform Fault (CTF). Onshore, Nsbnd S crustal extension dominates, while in central and south Peloponnesus the stress field appears rotated by 90°. Shearing-stress obliquity by 30° is indicated along the major strike-slip faults, consistent with clockwise crustal rotation. Within the lower crust, the stress field appears affected by plate kinematics and distributed deformation of the lower crust and upper mantle, which guide the regional geodynamics.

  9. Nitric oxide spatial distribution in single cultured hippocampus neurons: investigation by projection of reconstructed 3-D image and visualization technique.

    PubMed

    Yang, Yong; Ning, Gang-Min; Kutor, John; Hong, Di-Hui; Zhang, Mu; Zheng, Xiao-Xiang

    2004-01-01

    Recent studies have revealed a non-homogeneous distribution of nitric oxide synthase (NOS) in neurons. However, it is not yet clear whether the intracellular distribution of NOS represents the intracellular nitric oxide (NO) distribution. In the present study, software developed in our laboratory was applied to the reconstructed image obtained from confocal slice images in order to project the 3-D reconstructed images in any direction and to cut the neuron in different sections. This enabled the spatial distribution of NO to be visualized in any direction and section. In single neurons, NO distribution was seen to be heterogeneous. After stimulation with glutamate, the spatial changes in different areas of the neuron were different. These findings are consistent with immunocytochemical data on the intracellular localization of nNOS in hippocampus neurons, and will help to elucidate the specificity of nitric oxide signaling. Finally, the administration of SNAP and L-NAME was used to examine DAF-2 distribution in the neurons. The results showed this distribution to be homogenous; therefore, it did not account for the NO distribution results.

  10. Modeling the crystal distribution of lead-sulfate in lead-acid batteries with 3D spatial resolution

    NASA Astrophysics Data System (ADS)

    Huck, Moritz; Badeda, Julia; Sauer, Dirk Uwe

    2015-04-01

    For the reliability of lead-acid batteries it is important to have an accurate prediction of its response to load profiles. A model for the lead-sulfate growth is presented, which is embedded in a physical-chemical model with 3D spatial resolution is presented which is used for analyzing the different mechanism influencing the cell response. One import factor is the chemical dissolution and precipitation of lead-sulfate, since its dissolution speed limits the charging reaction and the accumulation of indissolvable of lead-sulfate leads to capacity degradation. The cell performance/behavior is not only determined by the amount of the sulfate but also by the radii and distribution of the crystals. The presented model can be used to for an improved understanding of the interaction of the different mechanisms.

  11. 3D-printing spatially varying BRDFs.

    PubMed

    Rouiller, Olivier; Bickel, Bernd; Kautz, Jan; Matusik, Wojciech; Alexa, Marc

    2013-01-01

    A new method fabricates custom surface reflectance and spatially varying bidirectional reflectance distribution functions (svBRDFs). Researchers optimize a microgeometry for a range of normal distribution functions and simulate the resulting surface's effective reflectance. Using the simulation's results, they reproduce an input svBRDF's appearance by distributing the microgeometry on the printed material's surface. This method lets people print svBRDFs on planar samples with current 3D printing technology, even with a limited set of printing materials. It extends naturally to printing svBRDFs on arbitrary shapes.

  12. In-situ 3D high-spatial resolution aquifer characterization with hydraulic parameter distribution at decameter scale

    NASA Astrophysics Data System (ADS)

    Hu, R.; Brauchler, R.; Hu, L.; Qiu, P.

    2015-12-01

    Currently, a major challenge in aquifer characterization is the determination of hydraulic parameters with high-spatial resolution. Since the mid-90's, various working groups have developed numerical evaluation approaches for hydraulic tomography: the inversion of hydraulic tests that have been recorded using tomographic arrangements. The practical application is often associated with long test times, complex evaluations, and prolonged computation times. In our study, a hydraulic tomographical data set consisted of 450 drawdown curves produced by a series of short term pumping tests conducted over 4 working days. Data was collected by two scientists without a technical staff. The tests were performed at the test site "Stegemühle", Göttingen, Germany in a confined sand and gravel aquifer with a thickness of 2-3 m. For the inversion, an approach has been used, which is based on the transformation of the groundwater flow equation into a form of Eikonal equation (Vasco et al., 2000). Utilizing this approach, the hydraulic data can be inverted using an Eikonal solver e.g. SIRT. This Eikonal solver is considerably computationally efficient and allows hundreds of draw down curves to be inverted on a standard laptop within minutes. Following the methodology described in Brauchler et al. 2013, 3D distribution of diffusivity and specific storage were directly reconstructed, and subsequently their product: the hydraulic conductivity. This study exemplifies that the required data can be recorded and analyzed efficiently in the field, which is a vital precondition for the in-situ field aquifer characterization with hydraulic tomography. Literature Vasco, D.W., Keers, H., Karasaki, K. (2000) Estimation of reservoir properties using transient pressure data: An asymptotic approach. Water Resour. Res. 36(12), 3447-3465 Brauchler, R., Hu, R., Hu, L., Jimenéz, S., Bayer, P., Ptak, T. (2013) Rapid field application of hydraulic tomography for resolving aquifer heterogeneity in

  13. A sediment structure model for describing the 3D spatial distribution of soil hydraulic properties of an artificial catchment using pedotransfer functions

    NASA Astrophysics Data System (ADS)

    Maurer, T.; Bartsch, R.; Schneider, A.; Gerke, H. H.

    2012-04-01

    Modelling the spatial heterogeneity of catchments is a prerequisite for the understanding of flow processes and the application of hydrological models. The initial structure represents also the starting point for catchment and ecosystem development. The quality of hydrologic modeling is often limited due to a lack of data or an oversimplification of aquifer properties. Predictions can be significantly improved by using spatial models that reproduce specific structural characteristics. Current geostatistical methods are unable the capture spatially complex conditions, e.g. abrupt changes in structures. More deterministic structure generator approaches are currently been discussed in hydrogeology for exploration. Process-based structure generators deduce structural characteristics e.g. from the known formation processes of the aquifer. The objective was to describe the spatial distribution of soil hydraulic properties in a catchment based on generated 3D sediments distributions. The approach was tested for the artificially constructed "Hühnerwasser" ("Chicken Creek") catchment. The catchment is located in the post-lignite mining area of Welzow-Süd in Lower Lusatia, Brandenburg, Germany. Here, the initial sediment distribution was governed primarily by dumping processes of the large-scale mining technology and the geological conditions at the excavation site. For the initially organic matter-free sandy sediments, the structure model generated the distributions of soil texture and soil bulk density within dumping spoil cones. These were represented by 2D cross sections with compacted central parts and particle-segregated flanks. The 3D geometry of the catchment was generated by sequencing of these basic structural elements along identified stacker trajectories, finally yielding a discretized 3D volume model using the GOCAD software. Based on these data, spatial distributions of hydraulic properties were calculated using well-established pedotransfer functions

  14. Spatial Visualization by Realistic 3D Views

    ERIC Educational Resources Information Center

    Yue, Jianping

    2008-01-01

    In this study, the popular Purdue Spatial Visualization Test-Visualization by Rotations (PSVT-R) in isometric drawings was recreated with CAD software that allows 3D solid modeling and rendering to provide more realistic pictorial views. Both the original and the modified PSVT-R tests were given to students and their scores on the two tests were…

  15. Spatial distribution of hydrocarbon reservoirs in the West Korea Bay Basin in the northern part of the Yellow Sea, estimated by 3-D gravity forward modelling

    NASA Astrophysics Data System (ADS)

    Choi, Sungchan; Ryu, In-Chang; Götze, H.-J.; Chae, Y.

    2017-01-01

    Although an amount of hydrocarbon has been discovered in the West Korea Bay Basin (WKBB), located in the North Korean offshore area, geophysical investigations associated with these hydrocarbon reservoirs are not permitted because of the current geopolitical situation. Interpretation of satellite-derived potential field data can be alternatively used to image the 3-D density distribution in the sedimentary basin associated with hydrocarbon deposits. We interpreted the TRIDENT satellite-derived gravity field data to provide detailed insights into the spatial distribution of sedimentary density structures in the WKBB. We used 3-D forward density modelling for the interpretation that incorporated constraints from existing geological and geophysical information. The gravity data interpretation and the 3-D forward modelling showed that there are two modelled areas in the central subbasin that are characterized by very low density structures, with a maximum density of about 2000 kg m-3, indicating some type of hydrocarbon reservoir. One of the anticipated hydrocarbon reservoirs is located in the southern part of the central subbasin with a volume of about 250 km3 at a depth of about 3000 m in the Cretaceous/Jurassic layer. The other hydrocarbon reservoir should exist in the northern part of the central subbasin, with an average volume of about 300 km3 at a depth of about 2500 m.

  16. Spatial distribution of Hydrocarbon Reservoirs in the West Korea Bay Basin in the northern part of the Yellow Sea, estimated by 3D gravity forward modeling

    NASA Astrophysics Data System (ADS)

    Choi, Sungchan; Ryu, In-Chang; Götze, H.-J.; Chae, Y.

    2016-10-01

    Although an amount of hydrocarbon has been discovered in the West Korea Bay Basin (WKBB), located in the North Korean offshore area, geophysical investigations associated with these hydrocarbon reservoirs are not permitted because of the current geopolitical situation. Interpretation of satellite- derived potential field data can be alternatively used to image the three-dimensional (3D) density distribution in the sedimentary basin associated with hydrocarbon deposits. We interpreted the TRIDENT satellite-derived gravity field data to provide detailed insights into the spatial distribution of sedimentary density structures in the WKBB. We used 3D forward density modeling for the interpretation that incorporated constraints from existing geological and geophysical information. The gravity data interpretation and the 3D forward modeling showed that there are two modeled areas in the central subbasin that are characterized by very low density structures, with a maximum density of about 2000 kg/m3, indicating some type of hydrocarbon reservoir. One of the anticipated hydrocarbon reservoirs is located in the southern part of the central subbasin with a volume of about 250 km3 at a depth of about 3000 m in the Cretaceous/Jurassic layer. The other hydrocarbon reservoir should exist in the northern part of the central subbasin, with an average volume of about 300 km3 at a depth of about 2500 m.

  17. Spatial synchronization of an insole pressure distribution system with a 3D motion analysis system for center of pressure measurements.

    PubMed

    Fradet, Laetitia; Siegel, Johannes; Dahl, Marieke; Alimusaj, Merkur; Wolf, Sebastian I

    2009-01-01

    Insole pressure systems are often more appropriate than force platforms for analysing center of pressure (CoP) as they are more flexible in use and indicate the position of the CoP that characterizes the contact foot/shoe during gait with shoes. However, these systems are typically not synchronized with 3D motion analysis systems. The present paper proposes a direct method that does not require a force platform for synchronizing an insole pressure system with a 3D motion analysis system. The distance separating 24 different CoPs measured optically and their equivalents measured by the insoles and transformed in the global coordinate system did not exceed 2 mm, confirming the suitability of the method proposed. Additionally, during static single limb stance, distances smaller than 7 mm and correlations higher than 0.94 were found between CoP trajectories measured with insoles and force platforms. Similar measurements were performed during gait to illustrate the characteristics of the CoP measured with each system. The distance separating the two CoPs was below 19 mm and the coefficient of correlation above 0.86. The proposed method offers the possibility to conduct new experiments, such as the investigation of proprioception in climbing stairs or in the presence of obstacles.

  18. 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.

  19. 3D Tomography of Accretionary Lapilli From The Island of Stromboli (Aeolian Archipelago, Italy): Spatial Arrangement, Internal Structure, Grain Size Distribution and Chemical Characterization

    NASA Astrophysics Data System (ADS)

    Morgavi, D.; Ielpo, M.; Valentini, L.; Laeger, K.; Paredes, J.; Petrelli, M.; Costa, A.; Perugini, D.

    2015-12-01

    The Secche di Lazzaro formation (7 Ka) is a phreatomagmatic deposit in the south-western part of the island of Stromboli (Aeolian Archipelago, Italy). The volcanic sequence is constituted by three main sub-units. In two of them abundant accretionary lapilli are present. We performed granulometric analysis to describe the spatial arrangement and the grain-size distribution of the lapilli inside the deposit. Lapilli were characterized by SEM investigations (BSE images). EMPA and LA-ICP-MS analyses of major and trace elements on glasses and minerals were performed. Although BSE images provide accurate morphological information, they do not allow the real 3D microstructure to be accessed. Therefore, non-invasive 3D imaging of the lapilli was performed by X-ray micro-tomography (X-mCT). The results of the X-mCT measurements provided a set of 2D cross-sectional slices stacked along the vertical axis, with a voxel size varying between 2.7 and 4.1 mm, depending on the size of the sample. The X-mCT images represent a mapping of X-ray attenuation, which in turn depends on the density of the phases distributed within the sample. This technique helped us to better constrain the particle and crystal distribution inside the accretionary lapilli. The recognized phases are: glass, clinopyroxene, plagioclase and Ti-Fe minerals. We discover also a high concentration of Na, Cl and SO3 in the ash matrix. This evidence is ubiquitous in all the accretionary lapilli. The work presented here could define a new route for future studies in the field of physical volcanology as X-ray micro-tomography could be a useful, non destructive technique to better characterize the internal structure of accretionary lapilli helping us to describe grain-size distribution of component particles and their spatial distribution within aggregates.

  20. The Spatial Extent and Distribution of Star Formation in 3D-HST Mergers at z is approximately 1.5

    NASA Technical Reports Server (NTRS)

    Schmidt, Kasper B.; Rix, Hans-Walter; da Cunha, Elisabete; Brammer, Gabriel B.; Cox, Thomas J.; Van Dokkum, Pieter; Foerster Schreiber, Natascha M.; Franx, Marijn; Fumagalli, Mattia; Jonsson, Patrik; Lundgren, Britt; Maseda, Michael V.; Momcheva, Ivelina; Nelson, Erica J.; Skelton, Rosalind E.; van der Wel, Arjen; Whitaker, Katherine E.

    2013-01-01

    We present an analysis of the spatial distribution of star formation in a sample of 60 visually identified galaxy merger candidates at z greater than 1. Our sample, drawn from the 3D-HST survey, is flux-limited and was selected to have high star formation rates based on fits of their broad-band, low spatial resolution spectral energy distributions. It includes plausible pre-merger (close pairs) and post-merger (single objects with tidal features) systems,with total stellar masses and star formation rates derived from multi-wavelength photometry. Here we use near-infrared slitless spectra from 3D-HST which produce H or [OIII] emission line maps as proxies for star-formation maps. This provides a first comprehensive high-resolution, empirical picture of where star formation occurred in galaxy mergers at the epoch of peak cosmic star formation rate. We find that detectable star formation can occur in one or both galaxy centres, or in tidal tails. The most common case (58%) is that star formation is largely concentrated in a single, compact region, coincident with the centre of (one of) the merger components. No correlations between star formation morphology and redshift, total stellar mass, or star formation rate are found. A restricted set of hydrodynamical merger simulationsbetween similarly massive and gas-rich objects implies that star formation should be detectable in both merger components, when the gas fractions of the individual components are the same. This suggests that z is approximately 1.5 mergers typically occur between galaxies whose gas fractions, masses, andor star formation rates are distinctly different from one another.

  1. 3D Spray Droplet Distributions in Sneezes

    NASA Astrophysics Data System (ADS)

    Techet, Alexandra; Scharfman, Barry; Bourouiba, Lydia

    2015-11-01

    3D spray droplet clouds generated during human sneezing are investigated using the Synthetic Aperture Feature Extraction (SAFE) method, which relies on light field imaging (LFI) and synthetic aperture (SA) refocusing computational photographic techniques. An array of nine high-speed cameras are used to image sneeze droplets and tracked the droplets in 3D space and time (3D + T). An additional high-speed camera is utilized to track the motion of the head during sneezing. In the SAFE method, the raw images recorded by each camera in the array are preprocessed and binarized, simplifying post processing after image refocusing and enabling the extraction of feature sizes and positions in 3D + T. These binary images are refocused using either additive or multiplicative methods, combined with thresholding. Sneeze droplet centroids, radii, distributions and trajectories are determined and compared with existing data. The reconstructed 3D droplet centroids and radii enable a more complete understanding of the physical extent and fluid dynamics of sneeze ejecta. These measurements are important for understanding the infectious disease transmission potential of sneezes in various indoor environments.

  2. Urbanisation and 3d Spatial - a Geometric Approach

    NASA Astrophysics Data System (ADS)

    Duncan, E. E.; Rahman, A. Abdul

    2013-09-01

    Urbanisation creates immense competition for space, this may be attributed to an increase in population owing to domestic and external tourism. Most cities are constantly exploring all avenues in maximising its limited space. Hence, urban or city authorities need to plan, expand and use such three dimensional (3D) space above, on and below the city space. Thus, difficulties in property ownership and the geometric representation of the 3D city space is a major challenge. This research, investigates the concept of representing a geometric topological 3D spatial model capable of representing 3D volume parcels for man-made constructions above and below the 3D surface volume parcel. A review of spatial data models suggests that the 3D TIN (TEN) model is significant and can be used as a unified model. The concepts, logical and physical models of 3D TIN for 3D volumes using tetrahedrons as the base geometry is presented and implemented to show man-made constructions above and below the surface parcel within a user friendly graphical interface. Concepts for 3D topology and 3D analysis are discussed. Simulations of this model for 3D cadastre are implemented. This model can be adopted by most countries to enhance and streamline geometric 3D property ownership for urban centres. 3D TIN concept for spatial modelling can be adopted for the LA_Spatial part of the Land Administration Domain Model (LADM) (ISO/TC211, 2012), this satisfies the concept of 3D volumes.

  3. 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

  4. Three-Dimensional (3D) Distribution

    DTIC Science & Technology

    2009-03-11

    witnessed by ongoing efforts in both Afghanistan and Iraq , must turn distribution challenges into opportunities by mastering Three-Dimensional (3D...sustainment. 5 Joint Logistics Functions •Supply •Services •Maintenance •Transportation • Health Service Support •General Engineering Joint Personnel...Maintenance •Transportation • Health Service Support •Explosive Ordinance Disposal •Human Resource Support •Legal Support •Religious Support •Financial

  5. Think3d!: Improving mathematics learning through embodied spatial training.

    PubMed

    Burte, Heather; Gardony, Aaron L; Hutton, Allyson; Taylor, Holly A

    2017-01-01

    Spatial thinking skills positively relate to Science, Technology, Engineering, and Math (STEM) outcomes, but spatial training is largely absent in elementary school. Elementary school is a time when children develop foundational cognitive skills that will support STEM learning throughout their education. Spatial thinking should be considered a foundational cognitive skill. The present research examined the impact of an embodied spatial training program on elementary students' spatial and mathematical thinking. Students in rural elementary schools completed spatial and math assessments prior to and after participating in an origami and pop-up paper engineering-based program, called Think3d!. Think3d! uses embodied tasks, such as folding and cutting paper, to train two-dimensional to three-dimensional spatial thinking. Analyses explored spatial thinking gains, mathematics gains - specifically for problem types expected to show gains from spatial training - and factors predicting mathematics gains. Results showed spatial thinking gains in two assessments. Using a math categorization to target problems more and less likely to be impacted by spatial training, we found that all students improved on real-world math problems and older students improved on visual and spatial math problems. Further, the results are suggestive of developmental time points for implementing embodied spatial training related to applying spatial thinking to math. Finally, the spatial thinking assessment that was most highly related to training activities also predicted math performance gains. Future research should explore developmental issues related to how embodied spatial training might support STEM learning and outcomes.

  6. Improving Nearest Neighbour Search in 3d Spatial Access Method

    NASA Astrophysics Data System (ADS)

    Suhaibaha, A.; Rahman, A. A.; Uznir, U.; Anton, F.; Mioc, D.

    2016-10-01

    Nearest Neighbour (NN) is one of the important queries and analyses for spatial application. In normal practice, spatial access method structure is used during the Nearest Neighbour query execution to retrieve information from the database. However, most of the spatial access method structures are still facing with unresolved issues such as overlapping among nodes and repetitive data entry. This situation will perform an excessive Input/Output (IO) operation which is inefficient for data retrieval. The situation will become more crucial while dealing with 3D data. The size of 3D data is usually large due to its detail geometry and other attached information. In this research, a clustered 3D hierarchical structure is introduced as a 3D spatial access method structure. The structure is expected to improve the retrieval of Nearest Neighbour information for 3D objects. Several tests are performed in answering Single Nearest Neighbour search and k Nearest Neighbour (kNN) search. The tests indicate that clustered hierarchical structure is efficient in handling Nearest Neighbour query compared to its competitor. From the results, clustered hierarchical structure reduced the repetitive data entry and the accessed page. The proposed structure also produced minimal Input/Output operation. The query response time is also outperformed compared to the other competitor. For future outlook of this research several possible applications are discussed and summarized.

  7. 3D Hail Size Distribution Interpolation/Extrapolation Algorithm

    NASA Technical Reports Server (NTRS)

    Lane, John

    2013-01-01

    Radar data can usually detect hail; however, it is difficult for present day radar to accurately discriminate between hail and rain. Local ground-based hail sensors are much better at detecting hail against a rain background, and when incorporated with radar data, provide a much better local picture of a severe rain or hail event. The previous disdrometer interpolation/ extrapolation algorithm described a method to interpolate horizontally between multiple ground sensors (a minimum of three) and extrapolate vertically. This work is a modification to that approach that generates a purely extrapolated 3D spatial distribution when using a single sensor.

  8. 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)

  9. Comprehending 3D Diagrams: Sketching to Support Spatial Reasoning.

    PubMed

    Gagnier, Kristin M; Atit, Kinnari; Ormand, Carol J; Shipley, Thomas F

    2016-11-25

    Science, technology, engineering, and mathematics (STEM) disciplines commonly illustrate 3D relationships in diagrams, yet these are often challenging for students. Failing to understand diagrams can hinder success in STEM because scientific practice requires understanding and creating diagrammatic representations. We explore a new approach to improving student understanding of diagrams that convey 3D relations that is based on students generating their own predictive diagrams. Participants' comprehension of 3D spatial diagrams was measured in a pre- and post-design where students selected the correct 2D slice through 3D geologic block diagrams. Generating sketches that predicated the internal structure of a model led to greater improvement in diagram understanding than visualizing the interior of the model without sketching, or sketching the model without attempting to predict unseen spatial relations. In addition, we found a positive correlation between sketched diagram accuracy and improvement on the diagram comprehension measure. Results suggest that generating a predictive diagram facilitates students' abilities to make inferences about spatial relationships in diagrams. Implications for use of sketching in supporting STEM learning are discussed.

  10. Deformation above mobile substrates, salt rheology and spatial distribution of salt structures: A 3D seismic study of the Permian southern North Sea

    NASA Astrophysics Data System (ADS)

    Hernandez, Karina; Mitchell, Neil; Huuse, Mads

    2016-04-01

    At ~255 Ma, cycles of evaporation of seawater led to deposition of evaporites including halite (rock salt) in the North Sea Basin. After later burial by denser sediments, the salt beds rose as pillows and diapirs. Assuming mobilization is due to Rayleigh-Taylor gravitational instability of heavy fluid (sediments) overlying light fluid (salts), theory suggests that the spacing between diapirs should be proportional to the original thickness of the salt layer. For example, a description of the theory in Turcotte and Schubert (1982) predicts structure wavelength to be 2.6 times the salt thickness. Previous research has explored mobilization of salt deposits assuming they have uniform rheology. However, this is not justified as halite rheology varies with temperature, grain size and pore brine content. Furthermore, evaporitic sequences contain various minerals besides halite (e.g., anhydrite, gypsum), which have different rheological properties. 3D seismic and well data reveal the internal structure of salt beds. The data have allowed characterization of structure wavelengths and salt thickness, so that the impact of internal composition and other properties on halokinetic behaviour can be assessed.

  11. StreamFlow 1.0: an extension to the spatially distributed snow model Alpine3D for hydrological modelling and deterministic stream temperature prediction

    NASA Astrophysics Data System (ADS)

    Gallice, Aurélien; Bavay, Mathias; Brauchli, Tristan; Comola, Francesco; Lehning, Michael; Huwald, Hendrik

    2016-12-01

    Climate change is expected to strongly impact the hydrological and thermal regimes of Alpine rivers within the coming decades. In this context, the development of hydrological models accounting for the specific dynamics of Alpine catchments appears as one of the promising approaches to reduce our uncertainty of future mountain hydrology. This paper describes the improvements brought to StreamFlow, an existing model for hydrological and stream temperature prediction built as an external extension to the physically based snow model Alpine3D. StreamFlow's source code has been entirely written anew, taking advantage of object-oriented programming to significantly improve its structure and ease the implementation of future developments. The source code is now publicly available online, along with a complete documentation. A special emphasis has been put on modularity during the re-implementation of StreamFlow, so that many model aspects can be represented using different alternatives. For example, several options are now available to model the advection of water within the stream. This allows for an easy and fast comparison between different approaches and helps in defining more reliable uncertainty estimates of the model forecasts. In particular, a case study in a Swiss Alpine catchment reveals that the stream temperature predictions are particularly sensitive to the approach used to model the temperature of subsurface flow, a fact which has been poorly reported in the literature to date. Based on the case study, StreamFlow is shown to reproduce hourly mean discharge with a Nash-Sutcliffe efficiency (NSE) of 0.82 and hourly mean temperature with a NSE of 0.78.

  12. Maximizing Modern Distribution of Complex Anatomical Spatial Information: 3D Reconstruction and Rapid Prototype Production of Anatomical Corrosion Casts of Human Specimens

    ERIC Educational Resources Information Center

    Li, Jianyi; Nie, Lanying; Li, Zeyu; Lin, Lijun; Tang, Lei; Ouyang, Jun

    2012-01-01

    Anatomical corrosion casts of human specimens are useful teaching aids. However, their use is limited due to ethical dilemmas associated with their production, their lack of perfect reproducibility, and their consumption of original specimens in the process of casting. In this study, new approaches with modern distribution of complex anatomical…

  13. Automated spatial alignment of 3D torso images.

    PubMed

    Bose, Arijit; Shah, Shishir K; Reece, Gregory P; Crosby, Melissa A; Beahm, Elisabeth K; Fingeret, Michelle C; Markey, Mia K; Merchant, Fatima A

    2011-01-01

    This paper describes an algorithm for automated spatial alignment of three-dimensional (3D) surface images in order to achieve a pre-defined orientation. Surface images of the torso are acquired from breast cancer patients undergoing reconstructive surgery to facilitate objective evaluation of breast morphology pre-operatively (for treatment planning) and/or post-operatively (for outcome assessment). Based on the viewing angle of the multiple cameras used for stereophotography, the orientation of the acquired torso in the images may vary from the normal upright position. Consequently, when translating this data into a standard 3D framework for visualization and analysis, the co-ordinate geometry differs from the upright position making robust and standardized comparison of images impractical. Moreover, manual manipulation and navigation of images to the desired upright position is subject to user bias. Automating the process of alignment and orientation removes operator bias and permits robust and repeatable adjustment of surface images to a pre-defined or desired spatial geometry.

  14. Ultrafast laser inscription of 3D components for spatial multiplexing

    NASA Astrophysics Data System (ADS)

    Thomson, Robert R.

    2016-02-01

    The thirst for bandwidth in telecommunications networks is becoming ever larger due to bandwidth hungry applications such as video-on-demand. To further increase the bandwidth capacity, engineers are now seeking to imprint information on the last remaining degree of freedom of the lightwave carrier - space. This has given rise to the field of Space Division Multiplexing (SDM). In essence, the concept of SDM simple; we aim to use the different spatial modes of an optical fibre as multiplexed data transmission channels. These modes could either be in the form of separate singlemodes in a multicore optical fibre, individual spatial modes of a multimode fibre, or indeed the individual spatial modes of a multimode multicore optical fibre. Regardless of the particular "flavour" of SDM in question, it is clear that significant interfacing issues exist between the optical fibres used in SDM and the conventional single-mode planar lightwave circuits that are essential to process the light (e.g. arrayed waveguide gratings and splitters), and efficient interconnect technologies will be required. One fabrication technology that has emerged as a possible route to solve these interconnection issues is ultrafast laser inscription (ULI), which relies on the use of focused ultrashort laser pulses to directly inscribe three-dimensional waveguide structures inside a bulk dielectric. In this paper, I describe some of the work that has been conducted around the world to apply the unique waveguide fabrication capabilities of ULI to the development of 3D photonic components for applications in SDM.

  15. Recovering 3D particle size distributions from 2D sections

    NASA Astrophysics Data System (ADS)

    Cuzzi, Jeffrey N.; Olson, Daniel M.

    2017-03-01

    We discuss different ways to convert observed, apparent particle size distributions from 2D sections (thin sections, SEM maps on planar surfaces, etc.) into true 3D particle size distributions. We give a simple, flexible, and practical method to do this; show which of these techniques gives the most faithful conversions; and provide (online) short computer codes to calculate both 2D-3D recoveries and simulations of 2D observations by random sectioning. The most important systematic bias of 2D sectioning, from the standpoint of most chondrite studies, is an overestimate of the abundance of the larger particles. We show that fairly good recoveries can be achieved from observed size distributions containing 100-300 individual measurements of apparent particle diameter.

  16. Visual search is influenced by 3D spatial layout.

    PubMed

    Finlayson, Nonie J; Grove, Philip M

    2015-10-01

    Many activities necessitate the deployment of attention to specific distances and directions in our three-dimensional (3D) environment. However, most research on how attention is deployed is conducted with two dimensional (2D) computer displays, leaving a large gap in our understanding about the deployment of attention in 3D space. We report how each of four parameters of 3D visual space influence visual search: 3D display volume, distance in depth, number of depth planes, and relative target position in depth. Using a search task, we find that visual search performance depends on 3D volume, relative target position in depth, and number of depth planes. Our results demonstrate an asymmetrical preference for targets in the front of a display unique to 3D search and show that arranging items into more depth planes reduces search efficiency. Consistent with research using 2D displays, we found slower response times to find targets in displays with larger 3D volumes compared with smaller 3D volumes. Finally, in contrast to the importance of target depth relative to other distractors, target depth relative to the fixation point did not affect response times or search efficiency.

  17. CARd-3D: Carbon Distribution in 3D Structure Program for Globular Proteins.

    PubMed

    Ekambaram, Rajasekaran; Kannaiyan, Akila; Marimuthu, Vijayasarathy; Swaminathan, Vinobha Chinnaiah; Renganathan, Senthil; Perumal, Ananda Gopu

    2014-01-01

    Spatial arrangement of carbon in protein structure is analyzed here. Particularly, the carbon fractions around individual atoms are compared. It is hoped that it follows the principle of 31.45% carbon around individual atoms. The results reveal that globular protein's atoms follow this principle. A comparative study on monomer versus dimer reveal that carbon is better distributed in dimeric form than in its monomeric form. Similar study on solid versus liquid structures reveals that the liquid (NMR) structure has better carbon distribution over the corresponding solid (X-Ray) structure. The carbon fraction distributions in fiber and toxin protein are compared. Fiber proteins follow the principle of carbon fraction distribution. At the same time it has another broad spectrum of carbon distribution than in globular proteins. The toxin protein follows an abnormal carbon fraction distribution. The carbon fraction distribution plays an important role in deciding the structure and shape of proteins. It is hoped to help in understanding the protein folding and function.

  18. 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.

  19. Think3d!: Training Spatial Thinking Fundamental to STEM Education

    ERIC Educational Resources Information Center

    Taylor, Holly A.; Hutton, Allyson

    2013-01-01

    This article describes the initial implementation of an innovative program for elementary-age children involving origami and pop-up paper engineering to promote visuospatial thinking. While spatial ability measures correlate with science, technology, engineering, and math (STEM) success, a focus on spatial thinking is all but missing in elementary…

  20. Multi-scale modelling of strongly heterogeneous 3D composite structures using spatial Voronoi tessellation

    NASA Astrophysics Data System (ADS)

    El Said, Bassam; Ivanov, Dmitry; Long, Andrew C.; Hallett, Stephen R.

    2016-03-01

    3D composite materials are characterized by complex internal yarn architectures, leading to complex deformation and failure development mechanisms. Net-shaped preforms, which are originally periodic in nature, lose their periodicity when the fabric is draped, deformed on a tool, and consolidated to create geometrically complex composite components. As a result, the internal yarn architecture, which dominates the mechanical behaviour, becomes dependent on the structural geometry. Hence, predicting the mechanical behaviour of 3D composites requires an accurate representation of the yarn architecture within structural scale models. When applied to 3D composites, conventional finite element modelling techniques are limited to either homogenised properties at the structural scale, or the unit cell scale for a more detailed material property definition. Consequently, these models fail to capture the complex phenomena occurring across multiple length scales and their effects on a 3D composite's mechanical response. Here a multi-scale modelling approach based on a 3D spatial Voronoi tessellation is proposed. The model creates an intermediate length scale suitable for homogenisation to deal with the non-periodic nature of the final material. Information is passed between the different length scales to allow for the effect of the structural geometry to be taken into account on the smaller scales. The stiffness and surface strain predictions from the proposed model have been found to be in good agreement with experimental results. The proposed modelling framework has been used to gain important insight into the behaviour of this category of materials. It has been observed that the strain and stress distributions are strongly dependent on the internal yarn architecture and consequently on the final component geometry. Even for simple coupon tests, the internal architecture and geometric effects dominate the mechanical response. Consequently, the behaviour of 3D woven

  1. 3D-CAD Effects on Creative Design Performance of Different Spatial Abilities Students

    ERIC Educational Resources Information Center

    Chang, Y.

    2014-01-01

    Students' creativity is an important focus globally and is interrelated with students' spatial abilities. Additionally, three-dimensional computer-assisted drawing (3D-CAD) overcomes barriers to spatial expression during the creative design process. Does 3D-CAD affect students' creative abilities? The purpose of this study was to explore the…

  2. Experiment for Integrating Dutch 3d Spatial Planning and Bim for Checking Building Permits

    NASA Astrophysics Data System (ADS)

    van Berlo, L.; Dijkmans, T.; Stoter, J.

    2013-09-01

    This paper presents a research project in The Netherlands in which several SMEs collaborated to create a 3D model of the National spatial planning information. This 2D information system described in the IMRO data standard holds implicit 3D information that can be used to generate an explicit 3D model. The project realized a proof of concept to generate a 3D spatial planning model. The team used the model to integrate it with several 3D Building Information Models (BIMs) described in the open data standard Industry Foundation Classes (IFC). Goal of the project was (1) to generate a 3D BIM model from spatial planning information to be used by the architect during the early design phase, and (2) allow 3D checking of building permits. The team used several technologies like CityGML, BIM clash detection and GeoBIM to explore the potential of this innovation. Within the project a showcase was created with a part of the spatial plan from the city of The Hague. Several BIM models were integrated in the 3D spatial plan of this area. A workflow has been described that demonstrates the benefits of collaboration between the spatial domain and the AEC industry in 3D. The research results in a showcase with conclusions and considerations for both national and international practice.

  3. Elemental concentration distribution in human fingernails - A 3D study

    NASA Astrophysics Data System (ADS)

    Pineda-Vargas, C. A.; Mars, J. A.; Gihwala, D.

    2012-02-01

    The verification of pathologies has normally been based on analysis of blood (serum and plasma), and physiological tissue. Recently, nails and in particular human fingernails have become an important medium for pathological studies, especially those of environmental origin. The analytical technique of PIXE has been used extensively in the analysis of industrial samples and human tissue specimens. The application of the analytical technique to nails has been mainly to bulk samples. In this study we use micro-PIXE and -RBS, as both complementary and supplementary, to determine the elemental concentration distribution of human fingernails of individuals. We report on the 3D quantitative elemental concentration distributions (QECDs) of various elements that include C, N and O as major elements (10-20%), P, S, Cl, K and Ca as minor elements (1-10%) and Fe, Mn, Zn, Ti, Na, Mg, Cu, Ni, Cr, Rb, Br, Sr and Se as trace elements (less than 1%). For PIXE and RBS the specimens were bombarded with a 3 MeV proton beam. To ascertain any correlations in the quantitative elemental concentration distributions, a linear traverse analysis was performed across the width of the nail. Elemental distribution correlations were also obtained.

  4. Distributed deformation and block rotation in 3D

    NASA Technical Reports Server (NTRS)

    Scotti, Oona; Nur, Amos; Estevez, Raul

    1990-01-01

    The authors address how block rotation and complex distributed deformation in the Earth's shallow crust may be explained within a stationary regional stress field. Distributed deformation is characterized by domains of sub-parallel fault-bounded blocks. In response to the contemporaneous activity of neighboring domains some domains rotate, as suggested by both structural and paleomagnetic evidence. Rotations within domains are achieved through the contemporaneous slip and rotation of the faults and of the blocks they bound. Thus, in regions of distributed deformation, faults must remain active in spite of their poor orientation in the stress field. The authors developed a model that tracks the orientation of blocks and their bounding faults during rotation in a 3D stress field. In the model, the effective stress magnitudes of the principal stresses (sigma sub 1, sigma sub 2, and sigma sub 3) are controlled by the orientation of fault sets in each domain. Therefore, adjacent fault sets with differing orientations may be active and may display differing faulting styles, and a given set of faults may change its style of motion as it rotates within a stationary stress regime. The style of faulting predicted by the model depends on a dimensionless parameter phi = (sigma sub 2 - sigma sub 3)/(sigma sub 1 - sigma sub 3). Thus, the authors present a model for complex distributed deformation and complex offset history requiring neither geographical nor temporal changes in the stress regime. They apply the model to the Western Transverse Range domain of southern California. There, it is mechanically feasible for blocks and faults to have experienced up to 75 degrees of clockwise rotation in a phi = 0.1 strike-slip stress regime. The results of the model suggest that this domain may first have accommodated deformation along preexisting NNE-SSW faults, reactivated as normal faults. After rotation, these same faults became strike-slip in nature.

  5. 3D concentration distributions of ion implants in amorphous solids

    NASA Astrophysics Data System (ADS)

    Günzler, R.; Weiser, M.; Kalbitz, S.

    1992-01-01

    Spatial distributions of implanted ions have been derived from depth profiles of implants at varied incidence angle by applying tomographic techniques. To this end we have developed a new version of an algorithm known as simultaneous iterative reconstruction technique (SIRT), which covers the experimental concentration range of about three decades. In addition, the finite depth resolution of the nuclear reaction analysis (NRA) is accounted for in our computer program. In this way, we have reconstructed the three-dimensional implantation distributions of 0.15 MeV 1H, 1.5 and 6 MeV 15N, and 4 MeV 30Si in amorphized Ge layers. The agreement with TRIM calculations is reasonable: 10% ± 0.5% for the first and 10% ± 5% for the second range moments. Consequences of the longitudinal and lateral tailing for ion beam applications to large scale integration problems are discussed.

  6. User Control and Task Authenticity for Spatial Learning in 3D Environments

    ERIC Educational Resources Information Center

    Dalgarno, Barney; Harper, Barry

    2004-01-01

    This paper describes two empirical studies which investigated the importance for spatial learning of view control and object manipulation within 3D environments. A 3D virtual chemistry laboratory was used as the research instrument. Subjects, who were university undergraduate students (34 in the first study and 80 in the second study), undertook…

  7. Types of Reasoning in 3D Geometry Thinking and Their Relation with Spatial Ability

    ERIC Educational Resources Information Center

    Pittalis, Marios; Christou, Constantinos

    2010-01-01

    The aim of this study is to describe and analyse the structure of 3D geometry thinking by identifying different types of reasoning and to examine their relation with spatial ability. To achieve this goal, two tests were administered to students in grades 5 to 9. The results of the study showed that 3D geometry thinking could be described by four…

  8. Stereoscopic 3D display technique using spatiotemporal interlacing has improved spatial and temporal properties.

    PubMed

    Johnson, Paul V; Kim, Joohwan; Banks, Martin S

    2015-04-06

    Stereoscopic 3D (S3D) displays use spatial or temporal interlacing to send different images to the two eyes. Temporal interlacing delivers images to the left and right eyes alternately in time; it has high effective spatial resolution but is prone to temporal artifacts. Spatial interlacing delivers even pixel rows to one eye and odd rows to the other eye simultaneously; it is subject to spatial limitations such as reduced spatial resolution. We propose a spatiotemporal-interlacing protocol that interlaces the left- and right-eye views spatially, but with the rows being delivered to each eye alternating with each frame. We performed psychophysical experiments and found that flicker, motion artifacts, and depth distortion are substantially reduced relative to the temporal-interlacing protocol, and spatial resolution is better than in the spatial-interlacing protocol. Thus, the spatiotemporal-interlacing protocol retains the benefits of spatial and temporal interlacing while minimizing or even eliminating the drawbacks.

  9. Stereoscopic 3D display technique using spatiotemporal interlacing has improved spatial and temporal properties

    PubMed Central

    Johnson, Paul V.; Kim, Joohwan; Banks, Martin S.

    2015-01-01

    Stereoscopic 3D (S3D) displays use spatial or temporal interlacing to send different images to the two eyes. Temporal interlacing delivers images to the left and right eyes alternately in time; it has high effective spatial resolution but is prone to temporal artifacts. Spatial interlacing delivers even pixel rows to one eye and odd rows to the other eye simultaneously; it is subject to spatial limitations such as reduced spatial resolution. We propose a spatiotemporal-interlacing protocol that interlaces the left- and right-eye views spatially, but with the rows being delivered to each eye alternating with each frame. We performed psychophysical experiments and found that flicker, motion artifacts, and depth distortion are substantially reduced relative to the temporal-interlacing protocol, and spatial resolution is better than in the spatial-interlacing protocol. Thus, the spatiotemporal-interlacing protocol retains the benefits of spatial and temporal interlacing while minimizing or even eliminating the drawbacks. PMID:25968758

  10. Layout consistent segmentation of 3-D meshes via conditional random fields and spatial ordering constraints.

    PubMed

    Zouhar, Alexander; Baloch, Sajjad; Tsin, Yanghai; Fang, Tong; Fuchs, Siegfried

    2010-01-01

    We address the problem of 3-D Mesh segmentation for categories of objects with known part structure. Part labels are derived from a semantic interpretation of non-overlapping subsurfaces. Our approach models the label distribution using a Conditional Random Field (CRF) that imposes constraints on the relative spatial arrangement of neighboring labels, thereby ensuring semantic consistency. To this end, each label variable is associated with a rich shape descriptor that is intrinsic to the surface. Randomized decision trees and cross validation are employed for learning the model, which is eventually applied using graph cuts. The method is flexible enough for segmenting even geometrically less structured regions and is robust to local and global shape variations.

  11. How spatial abilities and dynamic visualizations interplay when learning functional anatomy with 3D anatomical models.

    PubMed

    Berney, Sandra; Bétrancourt, Mireille; Molinari, Gaëlle; Hoyek, Nady

    2015-01-01

    The emergence of dynamic visualizations of three-dimensional (3D) models in anatomy curricula may be an adequate solution for spatial difficulties encountered with traditional static learning, as they provide direct visualization of change throughout the viewpoints. However, little research has explored the interplay between learning material presentation formats, spatial abilities, and anatomical tasks. First, to understand the cognitive challenges a novice learner would be faced with when first exposed to 3D anatomical content, a six-step cognitive task analysis was developed. Following this, an experimental study was conducted to explore how presentation formats (dynamic vs. static visualizations) support learning of functional anatomy, and affect subsequent anatomical tasks derived from the cognitive task analysis. A second aim was to investigate the interplay between spatial abilities (spatial visualization and spatial relation) and presentation formats when the functional anatomy of a 3D scapula and the associated shoulder flexion movement are learned. Findings showed no main effect of the presentation formats on performances, but revealed the predictive influence of spatial visualization and spatial relation abilities on performance. However, an interesting interaction between presentation formats and spatial relation ability for a specific anatomical task was found. This result highlighted the influence of presentation formats when spatial abilities are involved as well as the differentiated influence of spatial abilities on anatomical tasks.

  12. Estimating Fiber Orientation Distribution Functions in 3D-Polarized Light Imaging

    PubMed Central

    Axer, Markus; Strohmer, Sven; Gräßel, David; Bücker, Oliver; Dohmen, Melanie; Reckfort, Julia; Zilles, Karl; Amunts, Katrin

    2016-01-01

    Research of the human brain connectome requires multiscale approaches derived from independent imaging methods ideally applied to the same object. Hence, comprehensible strategies for data integration across modalities and across scales are essential. We have successfully established a concept to bridge the spatial scales from microscopic fiber orientation measurements based on 3D-Polarized Light Imaging (3D-PLI) to meso- or macroscopic dimensions. By creating orientation distribution functions (pliODFs) from high-resolution vector data via series expansion with spherical harmonics utilizing high performance computing and supercomputing technologies, data fusion with Diffusion Magnetic Resonance Imaging has become feasible, even for a large-scale dataset such as the human brain. Validation of our approach was done effectively by means of two types of datasets that were transferred from fiber orientation maps into pliODFs: simulated 3D-PLI data showing artificial, but clearly defined fiber patterns and real 3D-PLI data derived from sections through the human brain and the brain of a hooded seal. PMID:27147981

  13. A hybrid 3D spatial access method based on quadtrees and R-trees for globe data

    NASA Astrophysics Data System (ADS)

    Gong, Jun; Ke, Shengnan; Li, Xiaomin; Qi, Shuhua

    2009-10-01

    3D spatial access method for globe data is very crucial technique for virtual earth. This paper presents a brand-new maintenance method to index 3d objects distributed on the whole surface of the earth, which integrates the 1:1,000,000- scale topographic map tiles, Quad-tree and R-tree. Furthermore, when traditional methods are extended into 3d space, the performance of spatial index deteriorates badly, for example 3D R-tree. In order to effectively solve this difficult problem, a new algorithm of dynamic R-tree is put forward, which includes two sub-procedures, namely node-choosing and node-split. In the node-choosing algorithm, a new strategy is adopted, not like the traditional mode which is from top to bottom, but firstly from bottom to top then from top to bottom. This strategy can effectively solve the negative influence of node overlap. In the node-split algorithm, 2-to-3 split mode substitutes the traditional 1-to-2 mode, which can better concern the shape and size of nodes. Because of the rational tree shape, this R-tree method can easily integrate the concept of LOD. Therefore, it will be later implemented in commercial DBMS and adopted in time-crucial 3d GIS system.

  14. Fast Bayesian whole-brain fMRI analysis with spatial 3D priors.

    PubMed

    Sidén, Per; Eklund, Anders; Bolin, David; Villani, Mattias

    2017-02-01

    Spatial whole-brain Bayesian modeling of task-related functional magnetic resonance imaging (fMRI) is a great computational challenge. Most of the currently proposed methods therefore do inference in subregions of the brain separately or do approximate inference without comparison to the true posterior distribution. A popular such method, which is now the standard method for Bayesian single subject analysis in the SPM software, is introduced in Penny et al. (2005b). The method processes the data slice-by-slice and uses an approximate variational Bayes (VB) estimation algorithm that enforces posterior independence between activity coefficients in different voxels. We introduce a fast and practical Markov chain Monte Carlo (MCMC) scheme for exact inference in the same model, both slice-wise and for the whole brain using a 3D prior on activity coefficients. The algorithm exploits sparsity and uses modern techniques for efficient sampling from high-dimensional Gaussian distributions, leading to speed-ups without which MCMC would not be a practical option. Using MCMC, we are for the first time able to evaluate the approximate VB posterior against the exact MCMC posterior, and show that VB can lead to spurious activation. In addition, we develop an improved VB method that drops the assumption of independent voxels a posteriori. This algorithm is shown to be much faster than both MCMC and the original VB for large datasets, with negligible error compared to the MCMC posterior.

  15. Who Benefits from Learning with 3D Models?: The Case of Spatial Ability

    ERIC Educational Resources Information Center

    Huk, T.

    2006-01-01

    Empirical studies that focus on the impact of three-dimensional (3D) visualizations on learning are to date rare and inconsistent. According to the ability-as-enhancer hypothesis, high spatial ability learners should benefit particularly as they have enough cognitive capacity left for mental model construction. In contrast, the…

  16. How Spatial Abilities and Dynamic Visualizations Interplay When Learning Functional Anatomy with 3D Anatomical Models

    ERIC Educational Resources Information Center

    Berney, Sandra; Bétrancourt, Mireille; Molinari, Gaëlle; Hoyek, Nady

    2015-01-01

    The emergence of dynamic visualizations of three-dimensional (3D) models in anatomy curricula may be an adequate solution for spatial difficulties encountered with traditional static learning, as they provide direct visualization of change throughout the viewpoints. However, little research has explored the interplay between learning material…

  17. The Abilities of Understanding Spatial Relations, Spatial Orientation, and Spatial Visualization Affect 3D Product Design Performance: Using Carton Box Design as an Example

    ERIC Educational Resources Information Center

    Liao, Kun-Hsi

    2017-01-01

    Three-dimensional (3D) product design is an essential ability that students of subjects related to product design must acquire. The factors that affect designers' performance in 3D design are numerous, one of which is spatial abilities. Studies have reported that spatial abilities can be used to effectively predict people's performance in…

  18. 3D reconstruction of light flux distribution on arbitrary surfaces from 2D multi-photographic images.

    PubMed

    Chen, Xueli; Gao, Xinbo; Chen, Duofang; Ma, Xiaopeng; Zhao, Xiaohui; Shen, Man; Li, Xiangsi; Qu, Xiaochao; Liang, Jimin; Ripoll, Jorge; Tian, Jie

    2010-09-13

    Optical tomography can demonstrate accurate three-dimensional (3D) imaging that recovers the 3D spatial distribution and concentration of the luminescent probes in biological tissues, compared with planar imaging. However, the tomographic approach is extremely difficult to implement due to the complexity in the reconstruction of 3D surface flux distribution from multi-view two dimensional (2D) measurements on the subject surface. To handle this problem, a novel and effective method is proposed in this paper to determine the surface flux distribution from multi-view 2D photographic images acquired by a set of non-contact detectors. The method is validated with comparison experiments involving both regular and irregular surfaces. Reconstruction of the inside probes based on the reconstructed surface flux distribution further demonstrates the potential of the proposed method in its application in optical tomography.

  19. A coordinate transformation method for calculating the 3D light intensity distribution in ICF hohlraum

    NASA Astrophysics Data System (ADS)

    Lin, Zhili; Li, Xiaoyan; Zhao, Kuixia; Chen, Xudong; Chen, Mingyu; Pu, Jixiong

    2016-06-01

    For an inertial confinement fusion (ICF) system, the light intensity distribution in the hohlraum is key to the initial plasma excitation and later laser-plasma interaction process. Based on the concept of coordinate transformation of spatial points and vector, we present a robust method with a detailed procedure that makes the calculation of the three dimensional (3D) light intensity distribution in hohlraum easily. The method is intuitive but powerful enough to solve the complex cases of random number of laser beams with arbitrary polarization states and incidence angles. Its application is exemplified in the Shenguang III Facility (SG-III) that verifies its effectiveness and it is useful for guiding the design of hohlraum structure parameter.

  20. Spatial orientation in 3-D desktop displays: using rooms for organizing information.

    PubMed

    Colle, Herbert A; Reid, Gary B

    2003-01-01

    Understanding how spatial knowledge is acquired is important for spatial navigation and for improving the design of 3-D perspective interfaces. Configural spatial knowledge of object locations inside rooms is learned rapidly and easily (Colle & Reid, 1998), possibly because rooms afford local viewing in which objects are directly viewed or, alternatively, because of their structural features. The local viewing hypothesis predicts that the layout of objects outside of rooms also should be rapidly acquired when walls are removed and rooms are sufficiently close that participants can directly view and identify objects. It was evaluated using pointing and sketch map measures of configural knowledge with and without walls by varying distance, lighting levels, and observation instructions. Although within-room spatial knowledge was uniformly good, local viewing was not sufficient for improving spatial knowledge of objects in different rooms. Implications for navigation and 3-D interface design are discussed. Actual or potential applications of this research include the design of user interfaces, especially interfaces with 3-D displays.

  1. An impedance method for spatial sensing of 3D cell constructs--towards applications in tissue engineering.

    PubMed

    Canali, C; Mazzoni, C; Larsen, L B; Heiskanen, A; Martinsen, Ø G; Wolff, A; Dufva, M; Emnéus, J

    2015-09-07

    We present the characterisation and validation of multiplexed 4-terminal (4T) impedance measurements as a method for sensing the spatial location of cell aggregates within large three-dimensional (3D) gelatin scaffolds. The measurements were performed using an array of four rectangular chambers, each having eight platinum needle electrodes for parallel analysis. The electrode positions for current injection and voltage measurements were optimised by means of finite element simulations to maximise the sensitivity field distribution and spatial resolution. Eight different 4T combinations were experimentally tested in terms of the spatial sensitivity. The simulated sensitivity fields were validated using objects (phantoms) with different conductivity and size placed in different positions inside the chamber. This provided the detection limit (volume sensitivity) of 16.5%, i.e. the smallest detectable volume with respect to the size of the measurement chamber. Furthermore, the possibility for quick single frequency analysis was demonstrated by finding a common frequency of 250 kHz for all the presented electrode combinations. As final proof of concept, a high density of human hepatoblastoma (HepG2) cells were encapsulated in gelatin to form artificial 3D cell constructs and detected when placed in different positions inside large gelatin scaffolds. Taken together, these results open new perspectives for impedance-based sensing technologies for non-invasive monitoring in tissue engineering applications providing spatial information of constructs within biologically relevant 3D environments.

  2. Spatial and temporal analysis of DIII-D 3D magnetic diagnostic data

    NASA Astrophysics Data System (ADS)

    Strait, E. J.; King, J. D.; Hanson, J. M.; Logan, N. C.

    2016-11-01

    An extensive set of magnetic diagnostics in DIII-D is aimed at measuring non-axisymmetric "3D" features of tokamak plasmas, with typical amplitudes ˜10-3 to 10-5 of the total magnetic field. We describe hardware and software techniques used at DIII-D to condition the individual signals and analysis to estimate the spatial structure from an ensemble of discrete measurements. Applications of the analysis include detection of non-rotating MHD instabilities, plasma control, and validation of MHD stability and 3D equilibrium models.

  3. Spatial and temporal analysis of DIII-D 3D magnetic diagnostic data.

    PubMed

    Strait, E J; King, J D; Hanson, J M; Logan, N C

    2016-11-01

    An extensive set of magnetic diagnostics in DIII-D is aimed at measuring non-axisymmetric "3D" features of tokamak plasmas, with typical amplitudes ∼10(-3) to 10(-5) of the total magnetic field. We describe hardware and software techniques used at DIII-D to condition the individual signals and analysis to estimate the spatial structure from an ensemble of discrete measurements. Applications of the analysis include detection of non-rotating MHD instabilities, plasma control, and validation of MHD stability and 3D equilibrium models.

  4. Spatial and temporal analysis of DIII-D 3D magnetic diagnostic data

    DOE PAGES

    Strait, E. J.; King, J. D.; Hanson, J. M.; ...

    2016-08-11

    An extensive set of magnetic diagnostics in DIII-D is aimed at measuring non-axisymmetric "3D" features of tokamak plasmas, with typical amplitudes ~10-3 to 10-5 of the total magnetic field. We describe hardware and software techniques used at DIII-D to condition the individual signals and analysis to estimate the spatial structure from an ensemble of discrete measurements. Lastly, applications of the analysis include detection of non-rotating MHD instabilities, plasma control, and validation of MHD stability and 3D equilibrium models.

  5. A 3D analysis of spatial relationship between geological structure and groundwater profile around Kobe City, Japan: based on ARCGIS 3D Analyst.

    NASA Astrophysics Data System (ADS)

    Shibahara, A.; Tsukamoto, H.; Kazahaya, K.; Morikawa, N.; Takahashi, M.; Takahashi, H.; Yasuhara, M.; Ohwada, M.; Oyama, Y.; Inamura, A.; Handa, H.; Nakama, J.

    2008-12-01

    Kobe city is located on the northern side of Osaka sedimentary basin, Japan, containing 1,000-2,000 m thick Quaternary sediments. After the Hanshin-Awaji Earthquake (January 17, 1995), a number of geological and geophysical surveys were conducted in this region. Then high-temperature anomaly of groundwater accompanied with high Cl concentration was detected along fault systems in this area. In addition, dissolved He in groundwater showed nearly upper mantle-like 3He/4He ratio, although there were no Quaternary volcanic activities in this region. Some recent studies have assumed that these groundwater profiles are related with geological structure because some faults and joints can function as pathways for groundwater flow, and mantle-derived water can upwell through the fault system to the ground surface. To verify these hypotheses, we established 3D geological and hydrological model around Osaka sedimentary basin. Our primary goal is to analyze spatial relationship between geological structure and groundwater profile. In the study region, a number of geological and hydrological datasets, such as boring log data, seismic profiling data, groundwater chemical profile, were reported. We converted these datasets to meshed data on the GIS, and plotted in the three dimensional space to visualize spatial distribution. Furthermore, we projected seismic profiling data into three dimensional space and calculated distance between faults and sampling points, using Visual Basic for Applications (VBA) scripts. All 3D models are converted into VRML format, and can be used as a versatile dataset on personal computer. This research project has been conducted under the research contract with the Japan Nuclear Energy Safety Organization (JNES).

  6. Spatial resolution limits for the isotropic-3D PET detector X’tal cube

    NASA Astrophysics Data System (ADS)

    Yoshida, Eiji; Tashima, Hideaki; Hirano, Yoshiyuki; Inadama, Naoko; Nishikido, Fumihiko; Murayama, Hideo; Yamaya, Taiga

    2013-11-01

    Positron emission tomography (PET) has become a popular imaging method in metabolism, neuroscience, and molecular imaging. For dedicated human brain and small animal PET scanners, high spatial resolution is needed to visualize small objects. To improve the spatial resolution, we are developing the X’tal cube, which is our new PET detector to achieve isotropic 3D positioning detectability. We have shown that the X’tal cube can achieve 1 mm3 uniform crystal identification performance with the Anger-type calculation even at the block edges. We plan to develop the X’tal cube with even smaller 3D grids for sub-millimeter crystal identification. In this work, we investigate spatial resolution of a PET scanner based on the X’tal cube using Monte Carlo simulations for predicting resolution performance in smaller 3D grids. For spatial resolution evaluation, a point source emitting 511 keV photons was simulated by GATE for all physical processes involved in emission and interaction of positrons. We simulated two types of animal PET scanners. The first PET scanner had a detector ring 14.6 cm in diameter composed of 18 detectors. The second PET scanner had a detector ring 7.8 cm in diameter composed of 12 detectors. After the GATE simulations, we converted the interacting 3D position information to digitalized positions for realistic segmented crystals. We simulated several X’tal cubes with cubic crystals from (0.5 mm)3 to (2 mm)3 in size. Also, for evaluating the effect of DOI resolution, we simulated several X’tal cubes with crystal thickness from (0.5 mm)3 to (9 mm)3. We showed that sub-millimeter spatial resolution was possible using cubic crystals smaller than (1.0 mm)3 even with the assumed physical processes. Also, the weighted average spatial resolutions of both PET scanners with (0.5 mm)3 cubic crystals were 0.53 mm (14.6 cm ring diameter) and 0.48 mm (7.8 cm ring diameter). For the 7.8 cm ring diameter, spatial resolution with 0.5×0.5×1.0 mm3 crystals

  7. “Taller and Shorter”: Human 3-D Spatial Memory Distorts Familiar Multilevel Buildings

    PubMed Central

    Brandt, Thomas; Huber, Markus; Schramm, Hannah; Kugler, Günter; Dieterich, Marianne; Glasauer, Stefan

    2015-01-01

    Animal experiments report contradictory findings on the presence of a behavioural and neuronal anisotropy exhibited in vertical and horizontal capabilities of spatial orientation and navigation. We performed a pointing experiment in humans on the imagined 3-D direction of the location of various invisible goals that were distributed horizontally and vertically in a familiar multilevel hospital building. The 21 participants were employees who had worked for years in this building. The hypothesis was that comparison of the experimentally determined directions and the true directions would reveal systematic inaccuracy or dimensional anisotropy of the localizations. The study provides first evidence that the internal representation of a familiar multilevel building was distorted compared to the dimensions of the true building: vertically 215% taller and horizontally 51% shorter. This was not only demonstrated in the mathematical reconstruction of the mental model based on the analysis of the pointing experiments but also by the participants’ drawings of the front view and the ground plan of the building. Thus, in the mental model both planes were altered in different directions: compressed for the horizontal floor plane and stretched for the vertical column plane. This could be related to human anisotropic behavioural performance of horizontal and vertical navigation in such buildings. PMID:26509927

  8. 3D Drop Size Distribution Extrapolation Algorithm Using a Single Disdrometer

    NASA Technical Reports Server (NTRS)

    Lane, John

    2012-01-01

    Determining the Z-R relationship (where Z is the radar reflectivity factor and R is rainfall rate) from disdrometer data has been and is a common goal of cloud physicists and radar meteorology researchers. The usefulness of this quantity has traditionally been limited since radar represents a volume measurement, while a disdrometer corresponds to a point measurement. To solve that problem, a 3D-DSD (drop-size distribution) method of determining an equivalent 3D Z-R was developed at the University of Central Florida and tested at the Kennedy Space Center, FL. Unfortunately, that method required a minimum of three disdrometers clustered together within a microscale network (.1-km separation). Since most commercial disdrometers used by the radar meteorology/cloud physics community are high-cost instruments, three disdrometers located within a microscale area is generally not a practical strategy due to the limitations of these kinds of research budgets. A relatively simple modification to the 3D-DSD algorithm provides an estimate of the 3D-DSD and therefore, a 3D Z-R measurement using a single disdrometer. The basis of the horizontal extrapolation is mass conservation of a drop size increment, employing the mass conservation equation. For vertical extrapolation, convolution of a drop size increment using raindrop terminal velocity is used. Together, these two independent extrapolation techniques provide a complete 3DDSD estimate in a volume around and above a single disdrometer. The estimation error is lowest along a vertical plane intersecting the disdrometer position in the direction of wind advection. This work demonstrates that multiple sensors are not required for successful implementation of the 3D interpolation/extrapolation algorithm. This is a great benefit since it is seldom that multiple sensors in the required spatial arrangement are available for this type of analysis. The original software (developed at the University of Central Florida, 1998.- 2000) has

  9. Distributed snow and rock temperature modelling in steep rock walls using Alpine3D

    NASA Astrophysics Data System (ADS)

    Haberkorn, Anna; Wever, Nander; Hoelzle, Martin; Phillips, Marcia; Kenner, Robert; Bavay, Mathias; Lehning, Michael

    2017-02-01

    In this study we modelled the influence of the spatially and temporally heterogeneous snow cover on the surface energy balance and thus on rock temperatures in two rugged, steep rock walls on the Gemsstock ridge in the central Swiss Alps. The heterogeneous snow depth distribution in the rock walls was introduced to the distributed, process-based energy balance model Alpine3D with a precipitation scaling method based on snow depth data measured by terrestrial laser scanning. The influence of the snow cover on rock temperatures was investigated by comparing a snow-covered model scenario (precipitation input provided by precipitation scaling) with a snow-free (zero precipitation input) one. Model uncertainties are discussed and evaluated at both the point and spatial scales against 22 near-surface rock temperature measurements and high-resolution snow depth data from winter terrestrial laser scans.In the rough rock walls, the heterogeneously distributed snow cover was moderately well reproduced by Alpine3D with mean absolute errors ranging between 0.31 and 0.81 m. However, snow cover duration was reproduced well and, consequently, near-surface rock temperatures were modelled convincingly. Uncertainties in rock temperature modelling were found to be around 1.6 °C. Errors in snow cover modelling and hence in rock temperature simulations are explained by inadequate snow settlement due to linear precipitation scaling, missing lateral heat fluxes in the rock, and by errors caused by interpolation of shortwave radiation, wind and air temperature into the rock walls.Mean annual near-surface rock temperature increases were both measured and modelled in the steep rock walls as a consequence of a thick, long-lasting snow cover. Rock temperatures were 1.3-2.5 °C higher in the shaded and sunny rock walls, while comparing snow-covered to snow-free simulations. This helps to assess the potential error made in ground temperature modelling when neglecting snow in steep bedrock.

  10. Interactive Theater Experience with 3D Live Captured Actors and Spatial Sound

    NASA Astrophysics Data System (ADS)

    Cheok, Adrian David

    This chapter introduces a new reality interactive theater that combines the 3D Live human capturing system, spatial sound, augmented reality, human-oriented interaction, and ambient intelligence technologies. Actors/Dancers at different places remotely are captured by the 3D Live system and transmitted to the theater place in real time and rendered in 3D form and real size, thus they can play/dance with the local actors/dancers and virtual characters at the same place in real time. Audience interaction is allowed and handled by an Ambient Intelligence (AI) agent to generate new actions for virtual characters and send meaningful interactions to real actors. The spatial sound system provides the real 3D sound and at the same time generates special sound effects such as controlling the sound direction that only allows people in a certain direction to heard it. All these features combined together bring a totally new theater experience to both actors/dancers and audiences, and extend the grammar of the traditional theater.

  11. 3-D Distribution of Retained Colloids in Unsaturated Porous Media

    NASA Astrophysics Data System (ADS)

    Morales, V. L.; Perez-Reche, F. J.; Holzner, M.; Kinzelbach, W. K.; Otten, W.

    2013-12-01

    It is well accepted that colloid transport processes in porous media differ substantially between water saturated and unsaturated conditions. Differences are frequently ascribed to colloid immobilization by association with interfaces with the gas, as well as to restrictions of the liquid medium through which colloids are transported. Such factors depend on interfacial conditions provided by the water saturation of the porous medium. Yet, the current understanding of the importance of colloid retention at gas interfaces is based on observations of single pores or two-dimensional pore network representations, leaving open the question of their statistical significance when all pores in the medium are considered. In order to address this question, column experiments were performed using a model porous medium of glass beads through which colloidal silver particles were transported for conditions of varying water content. X-ray microtomography was subsequently employed as a non-destructive imaging technique to obtain pore-scale information of the entire column regarding: i) the presence and distribution of the four main locations where colloids can become retained (interfaces with the liquid-solid, gas-liquid and gas-solid, and the bulk liquid), ii) deposition profiles of colloids along the column classified by the available retention location, iii) morphological characteristics of the deposited colloidal aggregates, and iv) channel widths of 3-dimensional pore-water network representations. The results presented provide, for the first time, a direct statistical evaluation on the significance of colloid retention by attachment to the liquid-solid, gas-liquid, gas-solid interfaces, and by straining in the bulk liquid. Additionally, an effective-pore structure characteristic is proposed to improve predictions of mass removal by straining under various water saturations. A) Unsaturated conditions. B) Saturated conditions. Left: Tomograph slice illustrating with false

  12. Modeling 3-D permeability distribution in alluvial fans using facies architecture and geophysical acquisitions

    NASA Astrophysics Data System (ADS)

    Zhu, Lin; Gong, Huili; Dai, Zhenxue; Guo, Gaoxuan; Teatini, Pietro

    2017-02-01

    Alluvial fans are highly heterogeneous in hydraulic properties due to complex depositional processes, which make it difficult to characterize the spatial distribution of the hydraulic conductivity (K). An original methodology is developed to identify the spatial statistical parameters (mean, variance, correlation range) of the hydraulic conductivity in a three-dimensional (3-D) setting by using geological and geophysical data. More specifically, a large number of inexpensive vertical electric soundings are integrated with a facies model developed from borehole lithologic data to simulate the log10(K) continuous distributions in multiple-zone heterogeneous alluvial megafans. The Chaobai River alluvial fan in the Beijing Plain, China, is used as an example to test the proposed approach. Due to the non-stationary property of the K distribution in the alluvial fan, a multiple-zone parameterization approach is applied to analyze the conductivity statistical properties of different hydrofacies in the various zones. The composite variance in each zone is computed to describe the evolution of the conductivity along the flow direction. Consistently with the scales of the sedimentary transport energy, the results show that conductivity variances of fine sand, medium-coarse sand, and gravel decrease from the upper (zone 1) to the lower (zone 3) portion along the flow direction. In zone 1, sediments were moved by higher-energy flooding, which induces poor sorting and larger conductivity variances. The composite variance confirms this feature with statistically different facies from zone 1 to zone 3. The results of this study provide insights to improve our understanding on conductivity heterogeneity and a method for characterizing the spatial distribution of K in alluvial fans.

  13. Analysis of the 3D distribution of stacked self-assembled quantum dots by electron tomography

    PubMed Central

    2012-01-01

    The 3D distribution of self-assembled stacked quantum dots (QDs) is a key parameter to obtain the highest performance in a variety of optoelectronic devices. In this work, we have measured this distribution in 3D using a combined procedure of needle-shaped specimen preparation and electron tomography. We show that conventional 2D measurements of the distribution of QDs are not reliable, and only 3D analysis allows an accurate correlation between the growth design and the structural characteristics. PMID:23249477

  14. 3-D imaging mass spectrometry of protein distributions in mouse Neurofibromatosis 1 (NF1)-associated optic glioma.

    PubMed

    Anderson, David M G; Van de Plas, Raf; Rose, Kristie L; Hill, Salisha; Schey, Kevin L; Solga, Anne C; Gutmann, David H; Caprioli, Richard M

    2016-10-21

    Neurofibromatosis type 1 (NF1) is a common neurogenetic disorder, in which affected individuals develop tumors of the nervous system. Children with NF1 are particularly prone to brain tumors (gliomas) involving the optic pathway that can result in impaired vision. Since tumor formation and expansion requires a cooperative tumor microenvironment, it is important to identify the cellular and acellular components associated with glioma development and growth. In this study, we used 3-D matrix assisted laser desorption ionization imaging mass spectrometry (MALDI IMS) to measure the distributions of multiple molecular species throughout optic nerve tissue in mice with and without glioma, and to explore their spatial relationships within the 3-D volume of the optic nerve and chiasm. 3-D IMS studies often involve extensive workflows due to the high volume of sections required to generate high quality 3-D images. Herein, we present a workflow for 3-D data acquisition and volume reconstruction using mouse optic nerve tissue. The resulting 3-D IMS data yield both molecular similarities and differences between glioma-bearing and wild-type (WT) tissues, including protein distributions localizing to different anatomical subregions.

  15. Migration of bone marrow stromal cells in 3D: 4 color methodology reveals spatially and temporally coordinated events.

    PubMed

    Thibault, Marc M; Buschmann, Michael D

    2006-12-01

    The cytoskeleton plays a central role in many cell processes including directed cell migration. Since most previous work has investigated cell migration in two dimensions (2D), new methods are required to study movement in three dimensions (3D) while preserving 3D structure of the cytoskeleton. Most previous studies have labeled two cytoskeletal networks simultaneously, impeding an appreciation of their complex and dynamic interconnections. Here we report the development of a 4 color method to simultaneously image vimentin, actin, tubulin and the nucleus for high-resolution confocal microscopy of bone-marrow stromal cells (BMSCs) migrating through a porous membrane. Several methods were tested for structural preservation and labeling intensity resulting in identification of an optimized simultaneous fixation and permeabilization method using glutaraldehyde, paraformaldehyde and Triton X-100 followed by a quadruple fluorescent labeling method. This procedure was then applied at a sequence of time points to migrating cells, allowing temporal progression of migration to be assessed by visualizing all three networks plus the nucleus, providing new insights into 3D directed cell migration including processes such as leading edge structure, cytoskeletal distribution and nucleokinesis. Colocalization of actin and microtubules with distinct spatial arrangements at the cellular leading edge during migration, together with microtubule axial polarization supports recent reports indicating the pivotal role of microtubules in directed cell migration. This study also provides a foundation for 3D migration studies versus 2D studies, providing precise and robust methods to attain new insights into the cellular mechanisms of motility.

  16. Assessing spatial and temporal variability of phytoplankton communities' composition in the Iroise Sea ecosystem (Brittany, France): A 3D modeling approach. Part 1: Biophysical control over plankton functional types succession and distribution

    NASA Astrophysics Data System (ADS)

    Cadier, Mathilde; Gorgues, Thomas; Sourisseau, Marc; Edwards, Christopher A.; Aumont, Olivier; Marié, Louis; Memery, Laurent

    2017-01-01

    Understanding the dynamic interplay between physical, biogeochemical and biological processes represents a key challenge in oceanography, particularly in shelf seas where complex hydrodynamics are likely to drive nutrient distribution and niche partitioning of phytoplankton communities. The Iroise Sea includes a tidal front called the 'Ushant Front' that undergoes a pronounced seasonal cycle, with a marked signal during the summer. These characteristics as well as relatively good observational sampling make it a region of choice to study processes impacting phytoplankton dynamics. This innovative modeling study employs a phytoplankton-diversity model, coupled to a regional circulation model to explore mechanisms that alter biogeography of phytoplankton in this highly dynamic environment. Phytoplankton assemblages are mainly influenced by the depth of the mixed layer on a seasonal time scale. Indeed, solar incident irradiance is a limiting resource for phototrophic growth and small phytoplankton cells are advantaged over larger cells. This phenomenon is particularly relevant when vertical mixing is intense, such as during winter and early spring. Relaxation of wind-induced mixing in April causes an improvement of irradiance experienced by cells across the whole study area. This leads, in late spring, to a competitive advantage of larger functional groups such as diatoms as long as the nutrient supply is sufficient. This dominance of large, fast-growing autotrophic cells is also maintained during summer in the productive tidally-mixed shelf waters. In the oligotrophic surface layer of the western part of the Iroise Sea, small cells coexist in a greater proportion with large, nutrient limited cells. The productive Ushant tidal front's region (1800 mgC·m- 2·d- 1 between August and September) is also characterized by a high degree of coexistence between three functional groups (diatoms, micro/nano-flagellates and small eukaryotes/cyanobacteria). Consistent with

  17. GRID3D-v2: An updated version of the GRID2D/3D computer program for generating grid systems in complex-shaped three-dimensional spatial domains

    NASA Technical Reports Server (NTRS)

    Steinthorsson, E.; Shih, T. I-P.; Roelke, R. J.

    1991-01-01

    In order to generate good quality systems for complicated three-dimensional spatial domains, the grid-generation method used must be able to exert rather precise controls over grid-point distributions. Several techniques are presented that enhance control of grid-point distribution for a class of algebraic grid-generation methods known as the two-, four-, and six-boundary methods. These techniques include variable stretching functions from bilinear interpolation, interpolating functions based on tension splines, and normalized K-factors. The techniques developed in this study were incorporated into a new version of GRID3D called GRID3D-v2. The usefulness of GRID3D-v2 was demonstrated by using it to generate a three-dimensional grid system in the coolent passage of a radial turbine blade with serpentine channels and pin fins.

  18. Assessing soil water storage distribution under sprinkler irrigation by coupling 3D simulations and field observations

    NASA Astrophysics Data System (ADS)

    Taha, Uday; Shabeeb, Ahmed; dragonetti, giovanna; Lamaddalena, Nicola; Coppola, Antonio

    2016-04-01

    This work analyzed the variability of sprinkler irrigation application over a bare soil, both in terms of water application efficiency and uniformity, by integrating and comparing the information on the irrigation depth data (ID), as measured by catch cans, soil water storage in the upper root zone, as measured by TDR probes, and a 3D simulations of water flow in soils. Three irrigation tests were performed at three different pressures (2, 3 and 4 bar). A lateral water redistribution was observed and simulated after each irrigation event by comparing spatial distributions of site-specific water application efficiency (AEs), as well as ratios of site-specific actual water storage increase (SWEs) and irrigation depth (IDs) to the water content before irrigation. Because of soil water redistribution processes, distribution uniformity based on soil storages was systematically higher than the catch can uniformity. The obvious consequence of lateral water redistribution processes was that the soil smoothing action on non-uniformity observed at the surface increased both with depth and over time. At a given depth the uniformity of soil water storages always attained the same value, whatever the pressure considered and the catch can-based uniformity coefficient. It was concluded that, for the case of random distribution of ID, the uniformity of water storages is driven by the soil behavior rather than by the irrigation system.

  19. 3D beam shape estimation based on distributed coaxial cable interferometric sensor

    NASA Astrophysics Data System (ADS)

    Cheng, Baokai; Zhu, Wenge; Liu, Jie; Yuan, Lei; Xiao, Hai

    2017-03-01

    We present a coaxial cable interferometer based distributed sensing system for 3D beam shape estimation. By making a series of reflectors on a coaxial cable, multiple Fabry–Perot cavities are created on it. Two cables are mounted on the beam at proper locations, and a vector network analyzer (VNA) is connected to them to obtain the complex reflection signal, which is used to calculate the strain distribution of the beam in horizontal and vertical planes. With 6 GHz swept bandwidth on the VNA, the spatial resolution for distributed strain measurement is 0.1 m, and the sensitivity is 3.768 MHz mε ‑1 at the interferogram dip near 3.3 GHz. Using displacement-strain transformation, the shape of the beam is reconstructed. With only two modified cables and a VNA, this system is easy to implement and manage. Comparing to optical fiber based sensor systems, the coaxial cable sensors have the advantage of large strain and robustness, making this system suitable for structure health monitoring applications.

  20. 3D Kidney Segmentation from Abdominal Images Using Spatial-Appearance Models

    PubMed Central

    Khalifa, Fahmi; Soliman, Ahmed; Gimel'farb, Georgy

    2017-01-01

    Kidney segmentation is an essential step in developing any noninvasive computer-assisted diagnostic system for renal function assessment. This paper introduces an automated framework for 3D kidney segmentation from dynamic computed tomography (CT) images that integrates discriminative features from the current and prior CT appearances into a random forest classification approach. To account for CT images' inhomogeneities, we employ discriminate features that are extracted from a higher-order spatial model and an adaptive shape model in addition to the first-order CT appearance. To model the interactions between CT data voxels, we employed a higher-order spatial model, which adds the triple and quad clique families to the traditional pairwise clique family. The kidney shape prior model is built using a set of training CT data and is updated during segmentation using not only region labels but also voxels' appearances in neighboring spatial voxel locations. Our framework performance has been evaluated on in vivo dynamic CT data collected from 20 subjects and comprises multiple 3D scans acquired before and after contrast medium administration. Quantitative evaluation between manually and automatically segmented kidney contours using Dice similarity, percentage volume differences, and 95th-percentile bidirectional Hausdorff distances confirms the high accuracy of our approach. PMID:28280519

  1. A pathway-centric view of spatial proximity in the 3D nucleome across cell lines

    PubMed Central

    Karathia, Hiren; Kingsford, Carl; Girvan, Michelle; Hannenhalli, Sridhar

    2016-01-01

    In various contexts, spatially proximal genes have been shown to be functionally related. However, the extent to which spatial proximity of genes in a pathway contributes to the pathway’s context-specific activity is not known. Leveraging Hi-C data in six human cell-lines, we show that spatial proximity of genes in a pathway is highly correlated with the pathway’s context-specific expression and function. Furthermore, spatial proximity of pathway genes correlates with interactions of their protein products, and the specific pathway genes that are proximal to one another tend to occupy higher levels in the regulatory hierarchy. In addition to intra-pathway proximity, related pathways are spatially proximal to one another and housekeeping-genes tend to be proximal to several other pathways suggesting their coordinating role. Substantially extending previous works, our study reveals a pathway-centric organization of 3D-nucleome, whereby, functionally related interacting driver genes tend to be in spatial-proximity in a context-specific manner. PMID:27976707

  2. 3D Self-Potential Inversion for Monitoring DNAPL Contaminant Distributions

    NASA Astrophysics Data System (ADS)

    Minsley, B. J.; Sogade, J.; Vichabian, Y.; Morgan, F. D.

    2005-05-01

    Self-potential (SP) data are collected over an area known to be contaminated with Dense Non-Aqueous Phase Liquids (DNAPLs) at the Savannah River Site in South Carolina. The field experiment consists of approximately 100 SP measurements on a surface grid and in four boreholes, and is repeated after one year. DNAPLs are known to undergo redox reactions during their degradation in the environment, which is often biologically mediated. Self-potential geophysics is employed in this study because of its sensitivity to the in-situ biochemical processes that degrade the contaminants. These reactions provide an electrochemical source that is manifested as an SP signature at the measurement locations remote from the contaminated areas. 3D inversion of the SP data is therefore needed to spatially locate the distribution of sources, which is related to contaminant presence. The inversion incorporates the 3D resistivity structure collected at the same site, and is better constrained in depth by using borehole data and regularization. Ground truth information taken after the first field experiment provides concentration data with depth for several DNAPL species in five boreholes. There is a good correlation between the ground truth data and SP source inversion, though this comparison is limited by several factors: the difference in resolution of the ground truth and inverted data, and the dependence of the redox processes on other constituents that were not measured during the ground truthing, such as oxygen content or microbial presence. Inversion of the second year's dataset provides information on the changes in the contaminant distribution, either due to natural degradation or ongoing remediation.

  3. Zooplankton mortality in 3D ecosystem modelling considering variable spatial-temporal fish consumptions in the North Sea

    NASA Astrophysics Data System (ADS)

    Maar, Marie; Rindorf, Anna; Møller, Eva Friis; Christensen, Asbjørn; Madsen, Kristine S.; van Deurs, Mikael

    2014-05-01

    We tested the feasibility of imposing mesozooplankton mortality into a 3D model based on estimated consumption rates of the dominant planktivorous fish in the North Sea-Kattegat area. The spatial biomass distribution of Atlantic herring (Clupea harengus), horse mackerel (Trachurus trachurus), Atlantic mackerel (Scomber scombrus), sandeel (Ammodytidae) and European sprat (Sprattus sprattus) was derived from quarterly scientific trawl surveys and Danish commercial catches. Spatio-temporal indices of mortality were created based on the estimated biomasses and ingestion rates from the literature. The fish larvae grazing pressure was obtained from a spatial, size-based larval community model. In this model, larvae, herring and sandeel were the most important fish predators on mesozooplankton, but these groups had different spatial and temporal (seasonal) distributions. Fish larvae were particularly dominant in the eastern and southern areas in early summer. Herring and sandeel had the highest consumption in the central and north-western areas and were more important in late summer. The fish index changed the perceived annual, seasonal and spatial patterns in modelled mesozooplankton biomass, production and mortality. In the present study, the index was kept relatively simple and can be further developed with respect to the description of fish as well carnivorous zooplankton ingestion rates. The data input required to create the fish index is (i) planktivorous fish stock biomasses and (ii) relative fish spawning distribution information and (iii) physics (ocean currents and temperatures) for the region and situation of interest. The fish index seems promising as a realistic mortality term for lower trophic levels in 3D ecosystem models in areas with available data on fish stocks to improve management of marine resources.

  4. Sensor Spatial Distortion, Visual Latency, and Update Rate Effects on 3D Tracking in Virtual Environments

    NASA Technical Reports Server (NTRS)

    Ellis, S. R.; Adelstein, B. D.; Baumeler, S.; Jense, G. J.; Jacoby, R. H.; Trejo, Leonard (Technical Monitor)

    1998-01-01

    Several common defects that we have sought to minimize in immersing virtual environments are: static sensor spatial distortion, visual latency, and low update rates. Human performance within our environments during large amplitude 3D tracking was assessed by objective and subjective methods in the presence and absence of these defects. Results show that 1) removal of our relatively small spatial sensor distortion had minor effects on the tracking activity, 2) an Adapted Cooper-Harper controllability scale proved the most sensitive subjective indicator of the degradation of dynamic fidelity caused by increasing latency and decreasing frame rates, and 3) performance, as measured by normalized RMS tracking error or subjective impressions, was more markedly influenced by changing visual latency than by update rate.

  5. Gray and multigroup radiation transport through 3D binary stochastic media with different sphere radii distributions

    NASA Astrophysics Data System (ADS)

    Olson, Gordon L.

    2017-03-01

    Gray and multigroup radiation is transported through 3D media consisting of spheres randomly placed in a uniform background. Comparisons are made between using constant radii spheres and three different distributions of sphere radii. Because of the computational cost of 3D calculations, only the lowest angle order, n=1, is tested. If the mean chord length is held constant, using different radii distributions makes little difference. This is true for both gray and multigroup solutions. 3D transport solutions are compared to 2D and 1D solutions with the same mean chord lengths. 2D disk and 3D sphere media give solutions that are nearly identical while 1D slab solutions are fundamentally different.

  6. Gray and multigroup radiation transport through 3D binary stochastic media with different sphere radii distributions

    DOE PAGES

    Olson, Gordon Lee

    2016-12-06

    Here, gray and multigroup radiation is transported through 3D media consisting of spheres randomly placed in a uniform background. Comparisons are made between using constant radii spheres and three different distributions of sphere radii. Because of the computational cost of 3D calculations, only the lowest angle order, n=1, is tested. If the mean chord length is held constant, using different radii distributions makes little difference. This is true for both gray and multigroup solutions. 3D transport solutions are compared to 2D and 1D solutions with the same mean chord lengths. 2D disk and 3D sphere media give solutions that aremore » nearly identical while 1D slab solutions are fundamentally different.« less

  7. Gray and multigroup radiation transport through 3D binary stochastic media with different sphere radii distributions

    SciTech Connect

    Olson, Gordon Lee

    2016-12-06

    Here, gray and multigroup radiation is transported through 3D media consisting of spheres randomly placed in a uniform background. Comparisons are made between using constant radii spheres and three different distributions of sphere radii. Because of the computational cost of 3D calculations, only the lowest angle order, n=1, is tested. If the mean chord length is held constant, using different radii distributions makes little difference. This is true for both gray and multigroup solutions. 3D transport solutions are compared to 2D and 1D solutions with the same mean chord lengths. 2D disk and 3D sphere media give solutions that are nearly identical while 1D slab solutions are fundamentally different.

  8. 3D detection of obstacle distribution in walking guide system for the blind

    NASA Astrophysics Data System (ADS)

    Yoon, Myoung-Jong; Yu, Kee-Ho

    2007-12-01

    In this paper, the concept of a walking guide system with tactile display is introduced, and experiments of 3-D obstacle detection and tactile perception are carried out and analyzed. The algorithm of 3-D obstacle detection and the method of mapping the generated obstacle map and the tactile display device for the walking guide system are proposed. The experiment of the 3-D detection for the obstacle position using ultrasonic sensors is performed and estimated. Some design guidelines for a tactile display device that can display obstacle distribution is discussed.

  9. Three-Axis Distributed Fiber Optic Strain Measurement in 3D Woven Composite Structures

    NASA Technical Reports Server (NTRS)

    Castellucci, Matt; Klute, Sandra; Lally, Evan M.; Froggatt, Mark E.; Lowry, David

    2013-01-01

    Recent advancements in composite materials technologies have broken further from traditional designs and require advanced instrumentation and analysis capabilities. Success or failure is highly dependent on design analysis and manufacturing processes. By monitoring smart structures throughout manufacturing and service life, residual and operational stresses can be assessed and structural integrity maintained. Composite smart structures can be manufactured by integrating fiber optic sensors into existing composite materials processes such as ply layup, filament winding and three-dimensional weaving. In this work optical fiber was integrated into 3D woven composite parts at a commercial woven products manufacturing facility. The fiber was then used to monitor the structures during a VARTM manufacturing process, and subsequent static and dynamic testing. Low cost telecommunications-grade optical fiber acts as the sensor using a high resolution commercial Optical Frequency Domain Reflectometer (OFDR) system providing distributed strain measurement at spatial resolutions as low as 2mm. Strain measurements using the optical fiber sensors are correlated to resistive strain gage measurements during static structural loading. Keywords: fiber optic, distributed strain sensing, Rayleigh scatter, optical frequency domain reflectometry

  10. Sculpting 3D spatial selectivity with pairs of 2D pulses: A comparison of methods

    NASA Astrophysics Data System (ADS)

    Farkash, Gil; Dumez, Jean-Nicolas; Frydman, Lucio

    2016-12-01

    Enhancing the specificity of the spins' excitation can improve the capabilities of magnetic resonance. Exciting voxels with tailored 3D shapes reduces partial volume effects and enhances contrast, particularly in cases where cubic voxels or other simple geometries do not provide an optimal localization. Spatial excitation profiles of arbitrary shapes can be implemented using so-called multidimensional RF pulses, which are often limited in practice to 2D implementations owing to their sensitivity to field inhomogeneities. Recent work has shown the potential of spatio-temporally encoded (SPEN) pulses towards alleviating these constraints. In particular, 2D pulses operating in a so-called hybrid scheme where the "low-bandwidth" spatial dimension is sculpted by a SPEN strategy while an orthogonal axis is shaped by regular k-space encoding, have been shown resilient to chemical shift and B0 field inhomogeneities. In this work we explore the use of pairs of 2D pulses, with one of these addressing geometries in the x-y plane and the other in the x-z dimension, to sculpt complex 3D volumes in phantoms and in vivo. To overcome limitations caused by the RF discretization demanded by these 2D pulses, a number of "unfolding" techniques yielding images from the centerband RF excitation while deleting sideband contributions - even in cases where center- and side-bands severely overlap - were developed. Thus it was possible to increase the gradient strengths applied along the low bandwidth dimensions, significantly improving the robustness of this kind of 3D sculpting pulses. Comparisons against conventional pulses designed on the basis of pure k-space trajectories, are presented.

  11. A Spatially Periodic Solute Boundary for MT3DMS and PHT3D.

    PubMed

    Laattoe, Tariq; Post, Vincent E A; Werner, Adrian D

    2016-12-14

    The assumption of spatial repetition is commonly made when producing bedform scale models of the hyporheic zone. Two popular solute transport codes, MT3DMS and PHT3D, do not currently provide the necessary boundary condition required to simulate spatial periodicity in hyporheic zone transport problems. In this study, we develop a spatially periodic boundary (SPB) for solutes that is compatible with a SPB that was previously developed for MODFLOW to simulate the flow component of spatially periodic problems. The approach is ideal for simulating groundwater flow and transport patterns under repeating surface features, such as ripples or dunes on the bottom of a lake or stream. The appropriate block-centered finite-difference approach to implement the boundary is presented and the necessary source code modifications are discussed. The performance of the solute SPB, operating in conjunction with the groundwater flow SPB, is explored through comparison of a multi-bedform hyporheic-zone model with a single bedform variant. The new boundary conditions perform well in situations where both dispersive effects and lateral seepage flux in the underflow regime beneath the hyporheic zone are minimal.

  12. The Effect of 3D-Modeling Training on Students' Spatial Reasoning Relative to Gender and Grade

    ERIC Educational Resources Information Center

    Šafhalter, Andrej; Vukman, Karin Bakracevic; Glodež, Srecko

    2016-01-01

    The aim of this research was to establish whether gender and age have an impact on spatial reasoning and its development through the use of 3D modeling. The study was conducted on a sample of 196 children from sixth to ninth grade, of whom 95 represented the experimental group and 101 the control group. The experimental group received 3D modeling…

  13. Using Computer-Aided Design Software and 3D Printers to Improve Spatial Visualization

    ERIC Educational Resources Information Center

    Katsio-Loudis, Petros; Jones, Millie

    2015-01-01

    Many articles have been published on the use of 3D printing technology. From prefabricated homes and outdoor structures to human organs, 3D printing technology has found a niche in many fields, but especially education. With the introduction of AutoCAD technical drawing programs and now 3D printing, learners can use 3D printed models to develop…

  14. Angular distribution of Auger electrons due to 3d-shell impact ionization of krypton

    NASA Technical Reports Server (NTRS)

    Omidvar, K.

    1977-01-01

    Cross sections for electron impact ionization of krypton due to ejection of a 3d-shell electron have been calculated using screened hydrogenic and Hartree-Slater wavefunctions for the target atom. While the total ionization cross sections in the two approximations are within 10% of each other, the Auger electron angular distribution, related to cross sections for specific magnetic quantum numbers of the 3d electrons, are widely different in the two approximations. The angular distribution due to the Hartree-Slater approximation is in excellent agreement with measurement. The physical reason for the discrepancies in the two approximations is explained.

  15. GRID2D/3D: A computer program for generating grid systems in complex-shaped two- and three-dimensional spatial domains. Part 1: Theory and method

    NASA Technical Reports Server (NTRS)

    Shih, T. I.-P.; Bailey, R. T.; Nguyen, H. L.; Roelke, R. J.

    1990-01-01

    An efficient computer program, called GRID2D/3D was developed to generate single and composite grid systems within geometrically complex two- and three-dimensional (2- and 3-D) spatial domains that can deform with time. GRID2D/3D generates single grid systems by using algebraic grid generation methods based on transfinite interpolation in which the distribution of grid points within the spatial domain is controlled by stretching functions. All single grid systems generated by GRID2D/3D can have grid lines that are continuous and differentiable everywhere up to the second-order. Also, grid lines can intersect boundaries of the spatial domain orthogonally. GRID2D/3D generates composite grid systems by patching together two or more single grid systems. The patching can be discontinuous or continuous. For continuous composite grid systems, the grid lines are continuous and differentiable everywhere up to the second-order except at interfaces where different single grid systems meet. At interfaces where different single grid systems meet, the grid lines are only differentiable up to the first-order. For 2-D spatial domains, the boundary curves are described by using either cubic or tension spline interpolation. For 3-D spatial domains, the boundary surfaces are described by using either linear Coon's interpolation, bi-hyperbolic spline interpolation, or a new technique referred to as 3-D bi-directional Hermite interpolation. Since grid systems generated by algebraic methods can have grid lines that overlap one another, GRID2D/3D contains a graphics package for evaluating the grid systems generated. With the graphics package, the user can generate grid systems in an interactive manner with the grid generation part of GRID2D/3D. GRID2D/3D is written in FORTRAN 77 and can be run on any IBM PC, XT, or AT compatible computer. In order to use GRID2D/3D on workstations or mainframe computers, some minor modifications must be made in the graphics part of the program; no

  16. Three-axis distributed fiber optic strain measurement in 3D woven composite structures

    NASA Astrophysics Data System (ADS)

    Castellucci, Matt; Klute, Sandra; Lally, Evan M.; Froggatt, Mark E.; Lowry, David

    2013-03-01

    Recent advancements in composite materials technologies have broken further from traditional designs and require advanced instrumentation and analysis capabilities. Success or failure is highly dependent on design analysis and manufacturing processes. By monitoring smart structures throughout manufacturing and service life, residual and operational stresses can be assessed and structural integrity maintained. Composite smart structures can be manufactured by integrating fiber optic sensors into existing composite materials processes such as ply layup, filament winding and three-dimensional weaving. In this work optical fiber was integrated into 3D woven composite parts at a commercial woven products manufacturing facility. The fiber was then used to monitor the structures during a VARTM manufacturing process, and subsequent static and dynamic testing. Low cost telecommunications-grade optical fiber acts as the sensor using a high resolution commercial Optical Frequency Domain Reflectometer (OFDR) system providing distributed strain measurement at spatial resolutions as low as 2mm. Strain measurements using the optical fiber sensors are correlated to resistive strain gage measurements during static structural loading.

  17. Robust and Blind 3D Mesh Watermarking in Spatial Domain Based on Faces Categorization and Sorting

    NASA Astrophysics Data System (ADS)

    Molaei, Amir Masoud; Ebrahimnezhad, Hossein; Sedaaghi, Mohammad Hossein

    2016-06-01

    In this paper, a 3D watermarking algorithm in spatial domain is presented with blind detection. In the proposed method, a negligible visual distortion is observed in host model. Initially, a preprocessing is applied on the 3D model to make it robust against geometric transformation attacks. Then, a number of triangle faces are determined as mark triangles using a novel systematic approach in which faces are categorized and sorted robustly. In order to enhance the capability of information retrieval by attacks, block watermarks are encoded using Reed-Solomon block error-correcting code before embedding into the mark triangles. Next, the encoded watermarks are embedded in spherical coordinates. The proposed method is robust against additive noise, mesh smoothing and quantization attacks. Also, it is stout next to geometric transformation, vertices and faces reordering attacks. Moreover, the proposed algorithm is designed so that it is robust against the cropping attack. Simulation results confirm that the watermarked models confront very low distortion if the control parameters are selected properly. Comparison with other methods demonstrates that the proposed method has good performance against the mesh smoothing attacks.

  18. Optical lens-shift design for increasing spatial resolution of 3D ToF cameras

    NASA Astrophysics Data System (ADS)

    Lietz, Henrik; Hassan, M. Muneeb; Eberhardt, Jörg

    2017-02-01

    Sensor resolution of 3D time-of-flight (ToF) outdoor-capable cameras is strongly limited because of its large pixel dimensions. Computational imaging permits enhancement of the optical system's resolving power without changing physical sensor properties. Super-resolution (SR) algorithms superimpose several sub-pixel-shifted low-resolution (LR) images to overcome the system's limited spatial sampling rate. In this paper, we propose a novel opto-mechanical system to implement sub-pixel shifts by moving an optical lens. This method is more flexible in terms of implementing SR techniques than current sensor-shift approaches. In addition, we describe a SR observation model that has been optimized for the use of LR 3D ToF cameras. A state-of-the-art iteratively reweighted minimization algorithm executes the SR process. It is proven that our method achieves nearly the same resolution increase as if the pixel area would be halved physically. Resolution enhancement is measured objectively for amplitude images of a static object scene.

  19. A ‘fitness-wheel-shaped’ MEMS vector hydrophone for 3D spatial acoustic orientation

    NASA Astrophysics Data System (ADS)

    Wang, Renxin; Liu, Yuan; Xu, Wei; Bai, Bing; Zhang, Guojun; Liu, Jun; Xiong, Jijun; Zhang, Wendong; Xue, Chenyang; Zhang, Binzhen

    2017-04-01

    For the purpose of acquiring precise underwater 3D spatial orientation, a ‘fitness-wheel-shaped’ MEMS vector hydrophone (FWVH) is developed, which achieves monitoring of a tri-axial acoustic pressure differential via appropriate constructional design and strain readout. Compared to the previously reported T-structure-combined vector hydrophone (TSVH) which has a nonlinear relationship between output and external force, using the FWVH it is feasible in principle to achieve a tri-axial match, which make it promising in accurate acoustic orientation. A theoretic model for sensitivity is developed, where torque moment is taken into consideration to match the simulation and practical results. Superior to 3D force sensors, bandwidth is taken as the key index for the FWVH and is designed in detail with a compromise of sensitivity. In view of the bandwidth, the parameters are determined for detecting the signal in the range 20–300 Hz. A vibration test demonstrates tri-axial resonance frequencies. Finally, the frequency response curve of the FWVH shows that tri-axial sensitivities are consistent, agreeing with the analysis and simulation results, which reach  ‑174 dB (0 dB referring to 1 V µPa‑1) at 300 Hz.

  20. Spatial Sense and Perspective: A 3-D Model of the Orion Constellation

    NASA Astrophysics Data System (ADS)

    Heyer, I.; Slater, T. F.; Slater, S. J.

    2012-08-01

    Building a scale model of the Orion constellation provides spatial perspective for students studying astronomy. For this activity, students read a passage from literature that refers to stars being strange when seen from a different point of view. From a data set of the seven major stars of Orion they construct a 3-D distance scale model. This involves the subject areas of astronomy, mathematics, literature and art, as well as the skill areas of perspective, relative distances, line-of-sight, and basic algebra. This model will appear from one side exactly the way we see it from Earth. But when looking at it from any other angle the familiar constellation will look very alien. Students are encouraged to come up with their own names and stories to go with these new constellations. This activity has been used for K-12 teacher professional development classes, and would be most suitable for grades 6-12.

  1. Amoeboid migration mode adaption in quasi-3D spatial density gradients of varying lattice geometry

    NASA Astrophysics Data System (ADS)

    Gorelashvili, Mari; Emmert, Martin; Hodeck, Kai F.; Heinrich, Doris

    2014-07-01

    Cell migration processes are controlled by sensitive interaction with external cues such as topographic structures of the cell’s environment. Here, we present systematically controlled assays to investigate the specific effects of spatial density and local geometry of topographic structure on amoeboid migration of Dictyostelium discoideum cells. This is realized by well-controlled fabrication of quasi-3D pillar fields exhibiting a systematic variation of inter-pillar distance and pillar lattice geometry. By time-resolved local mean-squared displacement analysis of amoeboid migration, we can extract motility parameters in order to elucidate the details of amoeboid migration mechanisms and consolidate them in a two-state contact-controlled motility model, distinguishing directed and random phases. Specifically, we find that directed pillar-to-pillar runs are found preferably in high pillar density regions, and cells in directed motion states sense pillars as attractive topographic stimuli. In contrast, cell motion in random probing states is inhibited by high pillar density, where pillars act as obstacles for cell motion. In a gradient spatial density, these mechanisms lead to topographic guidance of cells, with a general trend towards a regime of inter-pillar spacing close to the cell diameter. In locally anisotropic pillar environments, cell migration is often found to be damped due to competing attraction by different pillars in close proximity and due to lack of other potential stimuli in the vicinity of the cell. Further, we demonstrate topographic cell guidance reflecting the lattice geometry of the quasi-3D environment by distinct preferences in migration direction. Our findings allow to specifically control amoeboid cell migration by purely topographic effects and thus, to induce active cell guidance. These tools hold prospects for medical applications like improved wound treatment, or invasion assays for immune cells.

  2. Analytical 3D views and virtual globes — scientific results in a familiar spatial context

    NASA Astrophysics Data System (ADS)

    Tiede, Dirk; Lang, Stefan

    In this paper we introduce analytical three-dimensional (3D) views as a means for effective and comprehensible information delivery, using virtual globes and the third dimension as an additional information carrier. Four case studies are presented, in which information extraction results from very high spatial resolution (VHSR) satellite images were conditioned and aggregated or disaggregated to regular spatial units. The case studies were embedded in the context of: (1) urban life quality assessment (Salzburg/Austria); (2) post-disaster assessment (Harare/Zimbabwe); (3) emergency response (Lukole/Tanzania); and (4) contingency planning (faked crisis scenario/Germany). The results are made available in different virtual globe environments, using the implemented contextual data (such as satellite imagery, aerial photographs, and auxiliary geodata) as valuable additional context information. Both day-to-day users and high-level decision makers are addressees of this tailored information product. The degree of abstraction required for understanding a complex analytical content is balanced with the ease and appeal by which the context is conveyed.

  3. Spatially monitoring oxygen level in 3D microfabricated cell culture systems using optical oxygen sensing beads.

    PubMed

    Wang, Lin; Acosta, Miguel A; Leach, Jennie B; Carrier, Rebecca L

    2013-04-21

    Capability of measuring and monitoring local oxygen concentration at the single cell level (tens of microns scale) is often desirable but difficult to achieve in cell culture. In this study, biocompatible oxygen sensing beads were prepared and tested for their potential for real-time monitoring and mapping of local oxygen concentration in 3D micro-patterned cell culture systems. Each oxygen sensing bead is composed of a silica core loaded with both an oxygen sensitive Ru(Ph2phen3)Cl2 dye and oxygen insensitive Nile blue reference dye, and a poly-dimethylsiloxane (PDMS) shell rendering biocompatibility. Human intestinal epithelial Caco-2 cells were cultivated on a series of PDMS and type I collagen based substrates patterned with micro-well arrays for 3 or 7 days, and then brought into contact with oxygen sensing beads. Using an image analysis algorithm to convert florescence intensity of beads to partial oxygen pressure in the culture system, tens of microns-size oxygen sensing beads enabled the spatial measurement of local oxygen concentration in the microfabricated system. Results generally indicated lower oxygen level inside wells than on top of wells, and local oxygen level dependence on structural features of cell culture surfaces. Interestingly, chemical composition of cell culture substrates also appeared to affect oxygen level, with type-I collagen based cell culture systems having lower oxygen concentration compared to PDMS based cell culture systems. In general, results suggest that oxygen sensing beads can be utilized to achieve real-time and local monitoring of micro-environment oxygen level in 3D microfabricated cell culture systems.

  4. 3D micro profile measurement with the method of spatial frequency domain analysis

    NASA Astrophysics Data System (ADS)

    Xu, Yongxiang

    2015-10-01

    3D micro profiles are often needed for measurement in many fields, e.g., binary optics, electronic industry, mechanical manufacturing, aeronautic and space industry, etc. In the case where height difference between two neighboring points of a test profile is equal to or greater than λ / 4, microscopic interferometry based on laser source will no longer be applicable because of the uncertainty in phase unwrapping. As white light possesses the characteristic of interference length approximate to zero, applying it for micro profilometry can avoid the trouble and can yield accurate results. Using self-developed Mirau-type scanning interference microscope, a step-like sample was tested twice, with 128 scanning interferograms recorded for each test. To process each set of the interferograms, the method of spatial frequency domain analysis was adopted. That is, for each point, by use of Furrier transform, white-light interference intensities were decomposed in spatial frequency domain, thus obtaining phase values corresponding to different wavenumbers; by using least square fitting on phases and wave numbers, a group-velocity OPD was gained for the very point; and finally in terms of the relation between relative height and the group-velocity OPD, the profile of the test sample was obtained. Two tests yielded same profile result for the sample, and step heights obtained were 50.88 nm and 50.94 nm, respectively. Meantime, the sample was also measured with a Zygo Newview 7200 topography instrument, with same profile result obtained and step height differing by 0.9 nm. In addition, data processing results indicate that chromatic dispersion equal to and higher than 2nd order is negligible when applying spatial frequency domain analysis method.

  5. Progressive Shape-Distribution-Encoder for Learning 3D Shape Representation.

    PubMed

    Xie, Jin; Zhu, Fan; Dai, Guoxian; Shao, Ling; Fang, Yi

    2017-03-01

    Since there are complex geometric variations with 3D shapes, extracting efficient 3D shape features is one of the most challenging tasks in shape matching and retrieval. In this paper, we propose a deep shape descriptor by learning shape distributions at different diffusion time via a progressive shape-distribution-encoder (PSDE). First, we develop a shape distribution representation with the kernel density estimator to characterize the intrinsic geometry structures of 3D shapes. Then, we propose to learn a deep shape feature through an unsupervised PSDE. Specially, the unsupervised PSDE aims at modeling the complex non-linear transform of the estimated shape distributions between consecutive diffusion time. In order to characterize the intrinsic structures of 3D shapes more efficiently, we stack multiple PSDEs to form a network structure. Finally, we concatenate all neurons in the middle hidden layers of the unsupervised PSDE network to form an unsupervised shape descriptor for retrieval. Furthermore, by imposing an additional constraint on the outputs of all hidden layers, we propose a supervised PSDE to form a supervised shape descriptor. For each hidden layer, the similarity between a pair of outputs from the same class is as large as possible and the similarity between a pair of outputs from different classes is as small as possible. The proposed method is evaluated on three benchmark 3D shape data sets with large geometric variations, i.e., McGill, SHREC'10 ShapeGoogle, and SHREC'14 Human data sets, and the experimental results demonstrate the superiority of the proposed method to the existing approaches.

  6. Population-based 3D genome structure analysis reveals driving forces in spatial genome organization

    PubMed Central

    Li, Wenyuan; Kalhor, Reza; Dai, Chao; Hao, Shengli; Gong, Ke; Zhou, Yonggang; Li, Haochen; Zhou, Xianghong Jasmine; Le Gros, Mark A.; Larabell, Carolyn A.; Chen, Lin; Alber, Frank

    2016-01-01

    Conformation capture technologies (e.g., Hi-C) chart physical interactions between chromatin regions on a genome-wide scale. However, the structural variability of the genome between cells poses a great challenge to interpreting ensemble-averaged Hi-C data, particularly for long-range and interchromosomal interactions. Here, we present a probabilistic approach for deconvoluting Hi-C data into a model population of distinct diploid 3D genome structures, which facilitates the detection of chromatin interactions likely to co-occur in individual cells. Our approach incorporates the stochastic nature of chromosome conformations and allows a detailed analysis of alternative chromatin structure states. For example, we predict and experimentally confirm the presence of large centromere clusters with distinct chromosome compositions varying between individual cells. The stability of these clusters varies greatly with their chromosome identities. We show that these chromosome-specific clusters can play a key role in the overall chromosome positioning in the nucleus and stabilizing specific chromatin interactions. By explicitly considering genome structural variability, our population-based method provides an important tool for revealing novel insights into the key factors shaping the spatial genome organization. PMID:26951677

  7. The impact of stereo 3D sports TV broadcasts on user's depth perception and spatial presence experience

    NASA Astrophysics Data System (ADS)

    Weigelt, K.; Wiemeyer, J.

    2014-03-01

    This work examines the impact of content and presentation parameters in 2D versus 3D on depth perception and spatial presence, and provides guidelines for stereoscopic content development for 3D sports TV broadcasts and cognate subjects. Under consideration of depth perception and spatial presence experience, a preliminary study with 8 participants (sports: soccer and boxing) and a main study with 31 participants (sports: soccer and BMX-Miniramp) were performed. The dimension (2D vs. 3D) and camera position (near vs. far) were manipulated for soccer and boxing. In addition for soccer, the field of view (small vs. large) was examined. Moreover, the direction of motion (horizontal vs. depth) was considered for BMX-Miniramp. Subjective assessments, behavioural tests and qualitative interviews were implemented. The results confirm a strong effect of 3D on both depth perception and spatial presence experience as well as selective influences of camera distance and field of view. The results can improve understanding of the perception and experience of 3D TV as a medium. Finally, recommendations are derived on how to use various 3D sports ideally as content for TV broadcasts.

  8. Spatial 3D infrastructure: display-independent software framework, high-speed rendering electronics, and several new displays

    NASA Astrophysics Data System (ADS)

    Chun, Won-Suk; Napoli, Joshua; Cossairt, Oliver S.; Dorval, Rick K.; Hall, Deirdre M.; Purtell, Thomas J., II; Schooler, James F.; Banker, Yigal; Favalora, Gregg E.

    2005-03-01

    We present a software and hardware foundation to enable the rapid adoption of 3-D displays. Different 3-D displays - such as multiplanar, multiview, and electroholographic displays - naturally require different rendering methods. The adoption of these displays in the marketplace will be accelerated by a common software framework. The authors designed the SpatialGL API, a new rendering framework that unifies these display methods under one interface. SpatialGL enables complementary visualization assets to coexist through a uniform infrastructure. Also, SpatialGL supports legacy interfaces such as the OpenGL API. The authors" first implementation of SpatialGL uses multiview and multislice rendering algorithms to exploit the performance of modern graphics processing units (GPUs) to enable real-time visualization of 3-D graphics from medical imaging, oil & gas exploration, and homeland security. At the time of writing, SpatialGL runs on COTS workstations (both Windows and Linux) and on Actuality"s high-performance embedded computational engine that couples an NVIDIA GeForce 6800 Ultra GPU, an AMD Athlon 64 processor, and a proprietary, high-speed, programmable volumetric frame buffer that interfaces to a 1024 x 768 x 3 digital projector. Progress is illustrated using an off-the-shelf multiview display, Actuality"s multiplanar Perspecta Spatial 3D System, and an experimental multiview display. The experimental display is a quasi-holographic view-sequential system that generates aerial imagery measuring 30 mm x 25 mm x 25 mm, providing 198 horizontal views.

  9. The research of 3D visualization techniques for the test of laser energy distribution

    NASA Astrophysics Data System (ADS)

    Liu, Lixin; Wang, Bo

    2013-07-01

    In the process of laser transmission in the atmosphere, the complexity and instability of the atmospheric composition that seriously interfere with, even change, the performance of the laser beam. The image of laser energy distribution can be captured and analyzed through infrared CCD and digital image processing technology. The basic features of laser energy density distribution, such as the location and power of the peak point and other basic parameters could be acquired; laser energy density distribution can display in real time continuous multi-frame; the 3D visualization of pseudo-color for laser energy density distribution could be displayed, that reflect the relative size and position of the energy distribution in the different regions of the laser spot, using the VC++, windows APIs and OpenGL programming. The laser energy density distribution can be observed from all angles.

  10. Assessment of averaging spatially correlated noise for 3-D radial imaging.

    PubMed

    Stobbe, Robert W; Beaulieu, Christian

    2011-07-01

    Any measurement of signal intensity obtained from an image will be corrupted by noise. If the measurement is from one voxel, an error bound associated with noise can be assigned if the standard deviation of noise in the image is known. If voxels are averaged together within a region of interest (ROI) and the image noise is uncorrelated, the error bound associated with noise will be reduced in proportion to the square root of the number of voxels in the ROI. However, when 3-D-radial images are created the image noise will be spatially correlated. In this paper, an equation is derived and verified with simulated noise for the computation of noise averaging when image noise is correlated, facilitating the assessment of noise characteristics for different 3-D-radial imaging methodologies. It is already known that if the radial evolution of projections are altered such that constant sampling density is produced in k-space, the signal-to-noise ratio (SNR) inefficiency of standard radial imaging (SR) can effectively be eliminated (assuming a uniform transfer function is desired). However, it is shown in this paper that the low-frequency noise power reduction of SR will produce beneficial (anti-) correlation of noise and enhanced noise averaging characteristics. If an ROI contains only one voxel a radial evolution altered uniform k-space sampling technique such as twisted projection imaging (TPI) will produce an error bound ~35% less with respect to noise than SR, however, for an ROI containing 16 voxels the SR methodology will facilitate an error bound ~20% less than TPI. If a filtering transfer function is desired, it is shown that designing sampling density to create the filter shape has both SNR and noise correlation advantages over sampling k-space uniformly. In this context SR is also beneficial. Two sets of 48 images produced from a saline phantom with sodium MRI at 4.7T are used to experimentally measure noise averaging characteristics of radial imaging and good

  11. Electromagnetic Response Inversion for a 3D Distribution of Conductivity/Dielect

    SciTech Connect

    Newman, Gregory

    2001-10-24

    NLCGCS inverts electromagnetic responses for a 3D distribution of electrical conductivity and dielectric permittivity within the earth for geophysical applications using single processor computers. The software comes bundled with a graphical user interface to aid in model construction and analysis and viewing of earth images. The solution employs both dipole and finite size source configurations for harmonic oscillatory sources. A new nonlinear preconditioner is included in the solution to speed up solution convergence.

  12. A Gaussian Distribution for Refined DT Invariants and 3D Partitions

    NASA Astrophysics Data System (ADS)

    Morrison, Andrew

    2014-11-01

    We show that the refined Donaldson-Thomas invariants of , suitably normalized, have a Gaussian distribution as limit law. Combinatorially, these numbers are given by weighted counts of 3D partitions. Our technique is to use the Hardy-Littlewood circle method to analyze the bivariate asymptotics of a q-deformation of MacMahon's function. The proof is based on that of E.M. Wright, who explored the single variable case.

  13. 3D Mass Spectrometry Imaging Reveals a Very Heterogeneous Drug Distribution in Tumors

    PubMed Central

    Giordano, S.; Morosi, L.; Veglianese, P.; Licandro, S. A.; Frapolli, R.; Zucchetti, M.; Cappelletti, G.; Falciola, L.; Pifferi, V.; Visentin, S.; D’Incalci, M.; Davoli, E.

    2016-01-01

    Mass Spectrometry Imaging (MSI) is a widespread technique used to qualitatively describe in two dimensions the distribution of endogenous or exogenous compounds within tissue sections. Absolute quantification of drugs using MSI is a recent challenge that just in the last years has started to be addressed. Starting from a two dimensional MSI protocol, we developed a three-dimensional pipeline to study drug penetration in tumors and to develop a new drug quantification method by MALDI MSI. Paclitaxel distribution and concentration in different tumors were measured in a 3D model of Malignant Pleural Mesothelioma (MPM), which is known to be a very heterogeneous neoplasm, highly resistant to different drugs. The 3D computational reconstruction allows an accurate description of tumor PTX penetration, adding information about the heterogeneity of tumor drug distribution due to the complex microenvironment. The use of an internal standard, homogenously sprayed on tissue slices, ensures quantitative results that are similar to those obtained using HPLC. The 3D model gives important information about the drug concentration in different tumor sub-volumes and shows that the great part of each tumor is not reached by the drug, suggesting the concept of pseudo-resistance as a further explanation for ineffective therapies and tumors relapse. PMID:27841316

  14. The three-dimensional elemental distribution based on the surface topography by confocal 3D-XRF analysis

    NASA Astrophysics Data System (ADS)

    Yi, Longtao; Qin, Min; Wang, Kai; Lin, Xue; Peng, Shiqi; Sun, Tianxi; Liu, Zhiguo

    2016-09-01

    Confocal three-dimensional micro-X-ray fluorescence (3D-XRF) is a good surface analysis technology widely used to analyse elements and elemental distributions. However, it has rarely been applied to analyse surface topography and 3D elemental mapping in surface morphology. In this study, a surface adaptive algorithm using the progressive approximation method was designed to obtain surface topography. A series of 3D elemental mapping analyses in surface morphology were performed in laboratories to analyse painted pottery fragments from the Majiayao Culture (3300-2900 BC). To the best of our knowledge, for the first time, sample surface topography and 3D elemental mapping were simultaneously obtained. Besides, component and depth analyses were also performed using synchrotron radiation confocal 3D-XRF and tabletop confocal 3D-XRF, respectively. The depth profiles showed that the sample has a layered structure. The 3D elemental mapping showed that the red pigment, black pigment, and pottery coat contain a large amount of Fe, Mn, and Ca, respectively. From the 3D elemental mapping analyses at different depths, a 3D rendering was obtained, clearly showing the 3D distributions of the red pigment, black pigment, and pottery coat. Compared with conventional 3D scanning, this method is time-efficient for analysing 3D elemental distributions and hence especially suitable for samples with non-flat surfaces.

  15. 3D high spectral and spatial resolution imaging of ex vivo mouse brain

    SciTech Connect

    Foxley, Sean Karczmar, Gregory S.; Domowicz, Miriam; Schwartz, Nancy

    2015-03-15

    Purpose: Widely used MRI methods show brain morphology both in vivo and ex vivo at very high resolution. Many of these methods (e.g., T{sub 2}{sup *}-weighted imaging, phase-sensitive imaging, or susceptibility-weighted imaging) are sensitive to local magnetic susceptibility gradients produced by subtle variations in tissue composition. However, the spectral resolution of commonly used methods is limited to maintain reasonable run-time combined with very high spatial resolution. Here, the authors report on data acquisition at increased spectral resolution, with 3-dimensional high spectral and spatial resolution MRI, in order to analyze subtle variations in water proton resonance frequency and lineshape that reflect local anatomy. The resulting information compliments previous studies based on T{sub 2}{sup *} and resonance frequency. Methods: The proton free induction decay was sampled at high resolution and Fourier transformed to produce a high-resolution water spectrum for each image voxel in a 3D volume. Data were acquired using a multigradient echo pulse sequence (i.e., echo-planar spectroscopic imaging) with a spatial resolution of 50 × 50 × 70 μm{sup 3} and spectral resolution of 3.5 Hz. Data were analyzed in the spectral domain, and images were produced from the various Fourier components of the water resonance. This allowed precise measurement of local variations in water resonance frequency and lineshape, at the expense of significantly increased run time (16–24 h). Results: High contrast T{sub 2}{sup *}-weighted images were produced from the peak of the water resonance (peak height image), revealing a high degree of anatomical detail, specifically in the hippocampus and cerebellum. In images produced from Fourier components of the water resonance at −7.0 Hz from the peak, the contrast between deep white matter tracts and the surrounding tissue is the reverse of the contrast in water peak height images. This indicates the presence of a shoulder in

  16. Quantum key distribution for security guarantees over QoS-driven 3D satellite networks

    NASA Astrophysics Data System (ADS)

    Wang, Ping; Zhang, Xi; Chen, Genshe; Pham, Khanh; Blasch, Erik

    2014-06-01

    In recent years, quantum-based communication is emerging as a new technique for ensuring secured communications because it can guarantee absolute security between two different remote entities. Quantum communication performs the transmission and exchange of quantum information among distant nodes within a network. Quantum key distribution (QKD) is a methodology for generating and distributing random encryption keys using the principles of quantum physics. In this paper, we investigate the techniques on how to efficiently use QKD in 3D satellite networks and propose an effective method to overcome its communications-distance limitations. In order to implement secured and reliable communications over wireless satellite links, we develop a free-space quantum channel model in satellite communication networks. To enlarge the communications distances over 3D satellite networks, we propose to employ the intermediate nodes to relay the unconditional keys and guarantee the Quantum Bit Error Rate (QBER) for security requirement over 3D satellite networks. We also propose the communication model for QKD security-Quality of Service (QoS) guarantee and an adaptive cooperative routing selection scheme to optimize the throughput performance of QKD-based satellite communications networks. The obtained simulation results verify our proposed schemes.

  17. Accurate Automatic Detection of Densely Distributed Cell Nuclei in 3D Space

    PubMed Central

    Tokunaga, Terumasa; Kanamori, Manami; Teramoto, Takayuki; Jang, Moon Sun; Kuge, Sayuri; Ishihara, Takeshi; Yoshida, Ryo; Iino, Yuichi

    2016-01-01

    To measure the activity of neurons using whole-brain activity imaging, precise detection of each neuron or its nucleus is required. In the head region of the nematode C. elegans, the neuronal cell bodies are distributed densely in three-dimensional (3D) space. However, no existing computational methods of image analysis can separate them with sufficient accuracy. Here we propose a highly accurate segmentation method based on the curvatures of the iso-intensity surfaces. To obtain accurate positions of nuclei, we also developed a new procedure for least squares fitting with a Gaussian mixture model. Combining these methods enables accurate detection of densely distributed cell nuclei in a 3D space. The proposed method was implemented as a graphical user interface program that allows visualization and correction of the results of automatic detection. Additionally, the proposed method was applied to time-lapse 3D calcium imaging data, and most of the nuclei in the images were successfully tracked and measured. PMID:27271939

  18. Efficient 3-D medical image registration using a distributed blackboard architecture.

    PubMed

    Tait, Roger J; Schaefer, Gerald; Hopgood, Adrian A; Zhu, Shao Ying

    2006-01-01

    A major drawback of 3-D medical image registration techniques is the performance bottleneck associated with re-sampling and similarity computation. Such bottlenecks limit registration applications in clinical situations where fast execution times are required and become particularly apparent in the case of registering 3-D data sets. In this paper a novel framework for high performance intensity-based volume registration is presented. Geometric alignment of both reference and sensed volume sets is achieved through a combination of scaling, translation, and rotation. Crucially, resampling and similarity computation is performed intelligently by a set of knowledge sources. The knowledge sources work in parallel and communicate with each other by means of a distributed blackboard architecture. Partitioning of the blackboard is used to balance communication and processing workloads. Large-scale registrations with substantial speedups, when compared with a conventional implementation, have been demonstrated.

  19. Comparison of 3D Orientation Distribution Functions Measured with Confocal Microscopy and Diffusion MRI

    PubMed Central

    Schilling, Kurt; Janve, Vaibhav; Gao, Yurui; Stepniewska, Iwona; Landman, Bennett A; Anderson, Adam W

    2016-01-01

    The ability of diffusion MRI (dMRI) fiber tractography to non-invasively map three-dimensional (3D) anatomical networks in the human brain has made it a valuable tool in both clinical and research settings. However, there are many assumptions inherent to any tractography algorithm that can limit the accuracy of the reconstructed fiber tracts. Among them is the assumption that the diffusion-weighted images accurately reflect the underlying fiber orientation distribution (FOD) in the MRI voxel. Consequently, validating dMRI’s ability to assess the underlying fiber orientation in each voxel is critical for its use as a biomedical tool. Here, using post-mortem histology and confocal microscopy, we present a method to perform histological validation of orientation functions in 3D, which has previously been limited to two-dimensional analysis of tissue sections. We demonstrate the ability to extract the 3D FOD from confocal z-stacks, and quantify the agreement between the MRI estimates of orientation information obtained using constrained spherical deconvolution (CSD) and the true geometry of the fibers. We find an orientation error of approximately 6° in voxels containing nearly parallel fibers, and 10-11° in crossing fiber regions, and note that CSD was unable to resolve fibers crossing at angles below 60° in our dataset. This is the first time the 3D white matter orientation distribution is calculated from histology and compared to dMRI. Thus, this technique serves as a gold standard for dMRI validation studies - providing the ability to determine the extent to which the dMRI signal is consistent with the histological FOD, and to establish how well different dMRI models can predict the ground truth FOD. PMID:26804781

  20. Designing Spatial Visualisation Tasks for Middle School Students with a 3D Modelling Software: An Instrumental Approach

    ERIC Educational Resources Information Center

    Turgut, Melih; Uygan, Candas

    2015-01-01

    In this work, certain task designs to enhance middle school students' spatial visualisation ability, in the context of an instrumental approach, have been developed. 3D modelling software, SketchUp®, was used. In the design process, software tools were focused on and, thereafter, the aim was to interpret the instrumental genesis and spatial…

  1. 3D Simulation Technology as an Effective Instructional Tool for Enhancing Spatial Visualization Skills in Apparel Design

    ERIC Educational Resources Information Center

    Park, Juyeon; Kim, Dong-Eun; Sohn, MyungHee

    2011-01-01

    The purpose of this study is to explore the effectiveness of 3D simulation technology for enhancing spatial visualization skills in apparel design education and further to suggest an innovative teaching approach using the technology. Apparel design majors in an introductory patternmaking course, at a large Midwestern University in the United…

  2. Simulation of the impact of 3-D porosity distribution in metallic U-10Zr fuels

    NASA Astrophysics Data System (ADS)

    Yun, Di; Yacout, Abdellatif M.; Stan, Marius; Bauer, Theodore H.; Wright, Arthur E.

    2014-05-01

    Evolution of porosity generated in metallic U-Zr fuel irradiated in fast spectrum reactors leads to changes in fuel properties and impacts important phenomena such as heat transport and constituent redistribution. The porosity is generated as a result of the accumulation of fission gases and is affected by the possible bond sodium infiltration into the fuel. Typically, the impact of porosity development on properties, such as thermal conductivity, is accounted for through empirical correlations that are dependent on porosity and infiltrated sodium fractions. Currently available simulation tools make it possible to take into account fuel 3-D porosity distributions, potentially eliminating the need for such correlations. This development allows for a more realistic representation of the porosity evolution in metallic fuel and creates a framework for truly mechanistic fuel development models. In this work, COMSOL multi-physics simulation platform is used to model 3-D porosity distributions and simulate heat transport in metallic U-10Zr fuel. Available experimental data regarding microstructural evolution of fuel that was irradiated in EBR-II and associated phase stability information are used to guide the simulation. The impact of changes in porosity characteristics on material properties is estimated and the results are compared with calculated temperature distributions. The simulations demonstrate the developed capability and importance of accounting for detailed porosity distribution features for accurate fuel performance evaluation.

  3. Correlation between spatial (3D) structure of pea and bean thylakoid membranes and arrangement of chlorophyll-protein complexes

    PubMed Central

    2012-01-01

    Background The thylakoid system in plant chloroplasts is organized into two distinct domains: grana arranged in stacks of appressed membranes and non-appressed membranes consisting of stroma thylakoids and margins of granal stacks. It is argued that the reason for the development of appressed membranes in plants is that their photosynthetic apparatus need to cope with and survive ever-changing environmental conditions. It is not known however, why different plant species have different arrangements of grana within their chloroplasts. It is important to elucidate whether a different arrangement and distribution of appressed and non-appressed thylakoids in chloroplasts are linked with different qualitative and/or quantitative organization of chlorophyll-protein (CP) complexes in the thylakoid membranes and whether this arrangement influences the photosynthetic efficiency. Results Our results from TEM and in situ CLSM strongly indicate the existence of different arrangements of pea and bean thylakoid membranes. In pea, larger appressed thylakoids are regularly arranged within chloroplasts as uniformly distributed red fluorescent bodies, while irregular appressed thylakoid membranes within bean chloroplasts correspond to smaller and less distinguished fluorescent areas in CLSM images. 3D models of pea chloroplasts show a distinct spatial separation of stacked thylakoids from stromal spaces whereas spatial division of stroma and thylakoid areas in bean chloroplasts are more complex. Structural differences influenced the PSII photochemistry, however without significant changes in photosynthetic efficiency. Qualitative and quantitative analysis of chlorophyll-protein complexes as well as spectroscopic investigations indicated a similar proportion between PSI and PSII core complexes in pea and bean thylakoids, but higher abundance of LHCII antenna in pea ones. Furthermore, distinct differences in size and arrangements of LHCII-PSII and LHCI-PSI supercomplexes between

  4. Characterization of gas hydrate distribution using conventional 3D seismic data in the Pearl River Mouth Basin, South China Sea

    USGS Publications Warehouse

    Wang, Xiujuan; Qiang, Jin; Collett, Timothy S.; Shi, Hesheng; Yang, Shengxiong; Yan, Chengzhi; Li, Yuanping; Wang, Zhenzhen; Chen, Duanxin

    2016-01-01

    A new 3D seismic reflection data volume acquired in 2012 has allowed for the detailed mapping and characterization of gas hydrate distribution in the Pearl River Mouth Basin in the South China Sea. Previous studies of core and logging data showed that gas hydrate occurrence at high concentrations is controlled by the presence of relatively coarse-grained sediment and the upward migration of thermogenic gas from the deeper sediment section into the overlying gas hydrate stability zone (BGHSZ); however, the spatial distribution of the gas hydrate remains poorly defined. We used a constrained sparse spike inversion technique to generate acoustic-impedance images of the hydrate-bearing sedimentary section from the newly acquired 3D seismic data volume. High-amplitude reflections just above the bottom-simulating reflectors (BSRs) were interpreted to be associated with the accumulation of gas hydrate with elevated saturations. Enhanced seismic reflections below the BSRs were interpreted to indicate the presence of free gas. The base of the BGHSZ was established using the occurrence of BSRs. In areas absent of well-developed BSRs, the BGHSZ was calculated from a model using the inverted P-wave velocity and subsurface temperature data. Seismic attributes were also extracted along the BGHSZ that indicate variations reservoir properties and inferred hydrocarbon accumulations at each site. Gas hydrate saturations estimated from the inversion of acoustic impedance of conventional 3D seismic data, along with well-log-derived rock-physics models were also used to estimate gas hydrate saturations. Our analysis determined that the gas hydrate petroleum system varies significantly across the Pearl River Mouth Basin and that variability in sedimentary properties as a product of depositional processes and the upward migration of gas from deeper thermogenic sources control the distribution of gas hydrates in this basin.

  5. An extension of the Saltykov method to quantify 3D grain size distributions in mylonites

    NASA Astrophysics Data System (ADS)

    Lopez-Sanchez, Marco A.; Llana-Fúnez, Sergio

    2016-12-01

    The estimation of 3D grain size distributions (GSDs) in mylonites is key to understanding the rheological properties of crystalline aggregates and to constraining dynamic recrystallization models. This paper investigates whether a common stereological method, the Saltykov method, is appropriate for the study of GSDs in mylonites. In addition, we present a new stereological method, named the two-step method, which estimates a lognormal probability density function describing the 3D GSD. Both methods are tested for reproducibility and accuracy using natural and synthetic data sets. The main conclusion is that both methods are accurate and simple enough to be systematically used in recrystallized aggregates with near-equant grains. The Saltykov method is particularly suitable for estimating the volume percentage of particular grain-size fractions with an absolute uncertainty of ±5 in the estimates. The two-step method is suitable for quantifying the shape of the actual 3D GSD in recrystallized rocks using a single value, the multiplicative standard deviation (MSD) parameter, and providing a precision in the estimate typically better than 5%. The novel method provides a MSD value in recrystallized quartz that differs from previous estimates based on apparent 2D GSDs, highlighting the inconvenience of using apparent GSDs for such tasks.

  6. Stress distribution in a premolar 3D model with anisotropic and isotropic enamel.

    PubMed

    Munari, Laís S; Cornacchia, Tulimar P M; Moreira, Allyson N; Gonçalves, Jason B; De Las Casas, Estevam B; Magalhães, Cláudia S

    2015-08-01

    The aim of this study was to compare the areas of stress concentration in a three-dimensional (3D) premolar tooth model with anisotropic or isotropic enamel using the finite element method. A computed tomography was imported to an image processing program to create the tooth model which was exported to a 3D modeling program. The mechanical properties and loading conditions were prescribed in Abaqus. In order to evaluate stresses, axial and oblique loads were applied simulating realistic conditions. Compression stress was observed on the side of load application, and tensile stress was observed on the opposite side. Tensile stress was concentrated mainly in the cervical region and in the alveolar insertion bone. Although stress concentration analyses of the isotropic 3D models produced similar stress distribution results when compared to the anisotropic models, tensile stress values shown by anisotropic models were smaller than the isotropic models. Oblique loads resulted in higher values of tensile stresses, which concentrate mainly in the cervical area of the tooth and in the alveolar bone insertion. Anisotropic properties must be utilized in enamel stress evaluation in non-carious cervical lesions.

  7. Distributed network, wireless and cloud computing enabled 3-D ultrasound; a new medical technology paradigm.

    PubMed

    Meir, Arie; Rubinsky, Boris

    2009-11-19

    Medical technologies are indispensable to modern medicine. However, they have become exceedingly expensive and complex and are not available to the economically disadvantaged majority of the world population in underdeveloped as well as developed parts of the world. For example, according to the World Health Organization about two thirds of the world population does not have access to medical imaging. In this paper we introduce a new medical technology paradigm centered on wireless technology and cloud computing that was designed to overcome the problems of increasing health technology costs. We demonstrate the value of the concept with an example; the design of a wireless, distributed network and central (cloud) computing enabled three-dimensional (3-D) ultrasound system. Specifically, we demonstrate the feasibility of producing a 3-D high end ultrasound scan at a central computing facility using the raw data acquired at the remote patient site with an inexpensive low end ultrasound transducer designed for 2-D, through a mobile device and wireless connection link between them. Producing high-end 3D ultrasound images with simple low-end transducers reduces the cost of imaging by orders of magnitude. It also removes the requirement of having a highly trained imaging expert at the patient site, since the need for hand-eye coordination and the ability to reconstruct a 3-D mental image from 2-D scans, which is a necessity for high quality ultrasound imaging, is eliminated. This could enable relatively untrained medical workers in developing nations to administer imaging and a more accurate diagnosis, effectively saving the lives of people.

  8. The 3D heat flux density distribution on a novel parabolic trough wavy absorber

    NASA Astrophysics Data System (ADS)

    Demagh, Yassine; Kabar, Yassine; Bordja, Lyes; Noui, Samira

    2016-05-01

    The non-uniform concentrated solar flux distribution on the outer surface of the absorber pipe can lead to large circumferential gradient temperature and high concentrated temperature of the absorber pipe wall, which is one of the primary causes of parabolic trough solar receiver breakdown. In this study, a novel shape of the parabolic trough absorber pipe is proposed as a solution to well homogenize the solar flux distribution, as well as, the temperature in the absorber wall. The conventional straight absorber located along the focal line of the parabola is replaced by wavy one (invention patent by Y. Demagh [1]) for which the heat flux density distribution on the outer surface varies in both axial and azimuthal directions (3D) while it varies only in the azimuthal direction on the former (2D). As far as we know, there is not previous study which has used a longitudinally wavy pipe as an absorber into the parabolic trough collector unit.

  9. Temperature distributions in the laser-heated diamond anvil cell from 3-D numerical modeling

    SciTech Connect

    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.

  10. A statistical approach to estimate the 3D size distribution of spheres from 2D size distributions

    USGS Publications Warehouse

    Kong, M.; Bhattacharya, R.N.; James, C.; Basu, A.

    2005-01-01

    Size distribution of rigidly embedded spheres in a groundmass is usually determined from measurements of the radii of the two-dimensional (2D) circular cross sections of the spheres in random flat planes of a sample, such as in thin sections or polished slabs. Several methods have been devised to find a simple factor to convert the mean of such 2D size distributions to the actual 3D mean size of the spheres without a consensus. We derive an entirely theoretical solution based on well-established probability laws and not constrained by limitations of absolute size, which indicates that the ratio of the means of measured 2D and estimated 3D grain size distribution should be r/4 (=.785). Actual 2D size distribution of the radii of submicron sized, pure Fe0 globules in lunar agglutinitic glass, determined from backscattered electron images, is tested to fit the gamma size distribution model better than the log-normal model. Numerical analysis of 2D size distributions of Fe0 globules in 9 lunar soils shows that the average mean of 2D/3D ratio is 0.84, which is very close to the theoretical value. These results converge with the ratio 0.8 that Hughes (1978) determined for millimeter-sized chondrules from empirical measurements. We recommend that a factor of 1.273 (reciprocal of 0.785) be used to convert the determined 2D mean size (radius or diameter) of a population of spheres to estimate their actual 3D size. ?? 2005 Geological Society of America.

  11. Spatial distribution visualization of PWM continuous variable-rate spray

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemical application is a dynamic spatial distribution process, during which spray liquid covers the targets with certain thickness and uniformity. Therefore, it is important to study the 2-D and 3-D (dimensional) spray distribution to evaluate spraying quality. The curve-surface generation methods ...

  12. Does spatial variation in environmental conditions affect recruitment? A study using a 3-D model of Peruvian anchovy

    NASA Astrophysics Data System (ADS)

    Xu, Yi; Rose, Kenneth A.; Chai, Fei; Chavez, Francisco P.; Ayón, Patricia

    2015-11-01

    We used a 3-dimensional individual-based model (3-D IBM) of Peruvian anchovy to examine how spatial variation in environmental conditions affects larval and juvenile growth and survival, and recruitment. Temperature, velocity, and phytoplankton and zooplankton concentrations generated from a coupled hydrodynamic Nutrients-Phytoplankton-Zooplankton-Detritus (NPZD) model, mapped to a three dimensional rectangular grid, were used to simulate anchovy populations. The IBM simulated individuals as they progressed from eggs to recruitment at 10 cm. Eggs and yolk-sac larvae were followed hourly through the processes of development, mortality, and movement (advection), and larvae and juveniles were followed daily through the processes of growth, mortality, and movement (advection plus behavior). A bioenergetics model was used to grow larvae and juveniles. The NPZD model provided prey fields which influence both food consumption rate as well as behavior mediated movement with individuals going to grids cells having optimal growth conditions. We compared predicted recruitment for monthly cohorts for 1990 through 2004 between the full 3-D IBM and a point (0-D) model that used spatially-averaged environmental conditions. The 3-D and 0-D versions generated similar interannual patterns in monthly recruitment for 1991-2004, with the 3-D results yielding consistently higher survivorship. Both versions successfully captured the very poor recruitment during the 1997-1998 El Niño event. Higher recruitment in the 3-D simulations was due to higher survival during the larval stage resulting from individuals searching for more favorable temperatures that lead to faster growth rates. The strong effect of temperature was because both model versions provided saturating food conditions for larval and juvenile anchovies. We conclude with a discussion of how explicit treatment of spatial variation affected simulated recruitment, other examples of fisheries modeling analyses that have used a

  13. Prototype Development Capabilities of 3D Spatial Interactions and Failures During Scenario Simulation

    SciTech Connect

    Steven Prescott; Ramprasad Sampath; Curtis Smith; Tony Koonce

    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 report addressed the methods, techniques, and resources used to develop a prototype for using 3D modeling and simulation engine to improve risk analysis and evaluate reactor structures and components for a given scenario. The simulations done for this evaluation were focused on external events, specifically tsunami floods, for a hypothetical nuclear power facility on a coastline.

  14. 3-D Visualisation: Using Internet-based Activities to Enhance Student Understanding of 3-dimensional Spatial Relationships

    NASA Astrophysics Data System (ADS)

    Boyle, A. P.; Williams, M.; Williams, P.

    2011-12-01

    Spatial ability forms its own category separate from verbal ability. Various spatial abilities have been identified over the last three decades and classified into three types: mental rotation, spatial rotation and spatial visualization, which have been linked to high performance in STEM subjects. Geoscience demands spatial thinking from learners and practitioners, and spatial literacy has been seen as a fundamental skill in Geography, Earth & Environmental Sciences (GEES disciplines) essential for progression. First year GEES students not only have to cope with new learning and teaching environments (Maguire et al., 2008), but, arriving with different science backgrounds, are faced with the challenge of developing essential skills that may be novel for them. These essential skills are subject-specific, as well as transferable, and require an understanding of 3-dimensional spatial relationships. However, spatial skills can be troublesome for some students to master. Not only do many students find difficulty in acquiring spatial skills, facing a succession of hurdles that need to be overcome in developing their understanding, but also educators, often strong spatial thinkers themselves and unaware of the degree to which some students are spatially-challenged, may find it difficult to help. Recent studies have suggested that performance on abstract and applied spatial tasks may be enhanced through instruction and practice and spatially-intensive geoscience courses may strengthen performance on spatial tasks. At Liverpool, many first year geoscience modules require understanding of 3-D spatial relationships, often from initial 2-D observations (e.g. mineralogy, petrography, vulcanology, sedimentology, palaeontology, geological map work, structural geology and fieldwork). In this paper we outline work, supported by the UK Subject Centre for Geography, Earth and Environmental Sciences (GEES), involving first year geosciences students at Liverpool, in which we explored

  15. Intensity distribution angular shaping - Practical approach for 3D optical beamforming

    NASA Astrophysics Data System (ADS)

    Wojtanowski, Jacek; Traczyk, Maciej; Zygmunt, Marek; Mierczyk, Zygmunt; Knysak, Piotr; Drozd, Tadeusz

    2014-12-01

    We present approach of optical design which enables to obtain aspheric lens shape optimized for providing the specific light power density distribution in space. Proposed method is based on the evaluation of corresponding angular intensity distribution which can be obtained by the decomposition of the desired spatial distribution into virtual light cones set and collapsing it to the equivalent angular fingerprint. Rigorous formulas have been derived to relate refractive aspheric shape and the corresponding intensity distribution which is used for lens optimization. Algorithms of modeling and optimization were implemented in Matlab© and the calculated designs were successfully tested in Zemax environment.

  16. 3D granulometry: grain-scale shape and size distribution from point cloud dataset of river environments

    NASA Astrophysics Data System (ADS)

    Steer, Philippe; Lague, Dimitri; Gourdon, Aurélie; Croissant, Thomas; Crave, Alain

    2016-04-01

    The grain-scale morphology of river sediments and their size distribution are important factors controlling the efficiency of fluvial erosion and transport. In turn, constraining the spatial evolution of these two metrics offer deep insights on the dynamics of river erosion and sediment transport from hillslopes to the sea. However, the size distribution of river sediments is generally assessed using statistically-biased field measurements and determining the grain-scale shape of river sediments remains a real challenge in geomorphology. Here we determine, with new methodological approaches based on the segmentation and geomorphological fitting of 3D point cloud dataset, the size distribution and grain-scale shape of sediments located in river environments. Point cloud segmentation is performed using either machine-learning algorithms or geometrical criterion, such as local plan fitting or curvature analysis. Once the grains are individualized into several sub-clouds, each grain-scale morphology is determined using a 3D geometrical fitting algorithm applied on the sub-cloud. If different geometrical models can be conceived and tested, only ellipsoidal models were used in this study. A phase of results checking is then performed to remove grains showing a best-fitting model with a low level of confidence. The main benefits of this automatic method are that it provides 1) an un-biased estimate of grain-size distribution on a large range of scales, from centimeter to tens of meters; 2) access to a very large number of data, only limited by the number of grains in the point-cloud dataset; 3) access to the 3D morphology of grains, in turn allowing to develop new metrics characterizing the size and shape of grains. The main limit of this method is that it is only able to detect grains with a characteristic size greater than the resolution of the point cloud. This new 3D granulometric method is then applied to river terraces both in the Poerua catchment in New-Zealand and

  17. 3D imaging of soil apparent electrical conductivity from VERIS data using a 1D spatially constrained inversion algorithm

    NASA Astrophysics Data System (ADS)

    Jesús Moral García, Francisco; Rebollo Castillo, Francisco Javier; Monteiro Santos, Fernando

    2016-04-01

    Maps of apparent electrical conductivity of the soil are commonly used in precision agriculture to indirectly characterize some important properties like salinity, water, and clay content. Traditionally, these studies are made through an empirical relationship between apparent electrical conductivity and properties measured in soil samples collected at a few locations in the experimental area and at a few selected depths. Recently, some authors have used not the apparent conductivity values but the soil bulk conductivity (in 2D or 3D) calculated from measured apparent electrical conductivity through the application of an inversion method. All the published works used data collected with electromagnetic (EM) instruments. We present a new software to invert the apparent electrical conductivity data collected with VERIS 3100 and 3150 (or the more recent version with three pairs of electrodes) using the 1D spatially constrained inversion method (1D SCI). The software allows the calculation of the distribution of the bulk electrical conductivity in the survey area till a depth of 1 m. The algorithm is applied to experimental data and correlations with clay and water content have been established using soil samples collected at some boreholes. Keywords: Digital soil mapping; inversion modelling; VERIS; soil apparent electrical conductivity.

  18. 3D geostatistical modeling of fracture system in a granitic massif to characterize hydraulic properties and fracture distribution

    NASA Astrophysics Data System (ADS)

    Koike, Katsuaki; Kubo, Taiki; Liu, Chunxue; Masoud, Alaa; Amano, Kenji; Kurihara, Arata; Matsuoka, Toshiyuki; Lanyon, Bill

    2015-10-01

    This study integrates 3D models of rock fractures from different sources and hydraulic properties aimed at identifying relationships between fractures and permeability. The Tono area in central Japan, chiefly overlain by Cretaceous granite, was examined because of the availability of a unique dataset from deep borehole data at 26 sites. A geostatistical method (GEOFRAC) that can incorporate orientations of sampled data was applied to 50,900 borehole fractures for spatial modeling of fractures over a 12 km by 8 km area, to a depth of 1.5 km. GEOFRAC produced a plausible 3D fracture model, in that the orientations of simulated fractures correspond to those of the sample data and the continuous fractures appeared near a known fault. Small-scale fracture distributions with dominant orientations were also characterized around the two shafts using fracture data from the shaft walls. By integrating the 3D model of hydraulic conductivity using sequential Gaussian simulation with the GEOFRAC fractures from the borehole data, the fracture sizes and directions that strongly affect permeable features were identified. Four fracture-related elements: lineaments from a shaded 10-m DEM, GEOFRAC fractures using the borehole and shaft data, and microcracks from SEM images, were used for correlating fracture attributes at different scales. The consistency of the semivariogram models of distribution densities was identified. Using an experimental relationship between hydraulic conductivity and fracture length, the fractures that typically affect the hydraulic properties at the drift scale were surmised to be in the range 100-200 m. These results are useful for a comprehensive understanding of rock fracture systems and their hydraulic characteristics at multiple scales in a target area.

  19. Exploring 3-D Virtual Reality Technology for Spatial Ability and Chemistry Achievement

    ERIC Educational Resources Information Center

    Merchant, Z.; Goetz, E. T.; Keeney-Kennicutt, W.; Cifuentes, L.; Kwok, O.; Davis, T. J.

    2013-01-01

    We investigated the potential of Second Life® (SL), a three-dimensional (3-D) virtual world, to enhance undergraduate students' learning of a vital chemistry concept. A quasi-experimental pre-posttest control group design was used to conduct the study. A total of 387 participants completed three assignment activities either in SL or using…

  20. Does spatial arrangement of 3D plants affect light transmission and extinction coefficient within maize crops?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Row spacing effects on light interception and extinction coefficient have been inconsistent for maize (Zea mays L.) when calculated with field measurements. To avoid inconsistencies due to variable light conditions and variable leaf canopies, we used a model to describe three-dimensional (3D) shoot ...

  1. Evaluation of potential human health effects associated with the agricultural uses of 1,3-D: Spatial and temporal stochastic risk analysis.

    PubMed

    Driver, Jeffrey H; Price, Paul S; Van Wesenbeeck, Ian; Ross, John H; Gehen, Sean; Holden, Larry R; Landenberger, Bryce; Hastings, Kerry; Yan, Zhongyu June; Rasoulpour, Reza

    2016-11-15

    Dow AgroSciences (DAS) markets and sells 1,3-Dichloropropene (1,3-D), the active ingredient in Telone®, which is used as a pre-plant soil fumigant nematicide in economically important crops in California. 1,3-D has been regulated as a "probable human carcinogen" and the California Department of Pesticide Regulation limits use of 1,3-D based on human health risk assessments for bystanders. This paper presents a risk characterization for bystanders based on advances in the assessment of both exposure and hazard. The revised bystander risk assessment incorporates significant advances: 1) new data on residency duration and mobility in communities where 1,3-D is in high demand; 2) new information on spatial and temporal concentrations of 1,3-D in air based on multi-year modeling using a validated model; and 3) a new stochastic spatial and temporal model of long-term exposures. Predicted distributions of long-term, chronic exposures indicate that current, and anticipated uses of 1,3-D would result in lifetime average daily doses lower than 0.002mg/kg/d, a dose associated with theoretical lifetime excess cancer risk of <10(-5) to >95% of the local population based on a non-threshold risk assessment approach. Additionally, examination of 1,3-D toxicity studies including new chronic toxicity data and mechanism of action supports the use of a non-linear, threshold based risk assessment approach. The estimated maximum annual average daily dose of <0.0016mg/kg/d derived from the updated exposure assessment was then compared with a threshold point of departure. The calculated margin of exposure is >1000-fold, a clear indication of acceptable risk for human health. In summary, the best available science supports 1,3-D's threshold nature of hazard and the revised exposure assessment supports that current agricultural uses of 1,3-D are associated with reasonable certainty of no harm, i.e., estimated long-term exposures pose insignificant health risks to bystanders even when the

  2. The lithospheric-scale 3D structural configuration of the North Alpine Foreland Basin constrained by gravity modelling and the calculation of the 3D load distribution

    NASA Astrophysics Data System (ADS)

    Przybycin, Anna M.; Scheck-Wenderoth, Magdalena; Schneider, Michael

    2014-05-01

    The North Alpine Foreland Basin is situated in the northern front of the European Alps and extends over parts of France, Switzerland, Germany and Austria. It formed as a wedge shaped depression since the Tertiary in consequence of the Euro - Adriatic continental collision and the Alpine orogeny. The basin is filled with clastic sediments, the Molasse, originating from erosional processes of the Alps and underlain by Mesozoic sedimentary successions and a Paleozoic crystalline crust. For our study we have focused on the German part of the basin. To investigate the deep structure, the isostatic state and the load distribution of this region we have constructed a 3D structural model of the basin and the Alpine area using available depth and thickness maps, regional scale 3D structural models as well as seismic and well data for the sedimentary part. The crust (from the top Paleozoic down to the Moho (Grad et al. 2008)) has been considered as two-parted with a lighter upper crust and a denser lower crust; the partition has been calculated following the approach of isostatic equilibrium of Pratt (1855). By implementing a seismic Lithosphere-Asthenosphere-Boundary (LAB) (Tesauro 2009) the crustal scale model has been extended to the lithospheric-scale. The layer geometry and the assigned bulk densities of this starting model have been constrained by means of 3D gravity modelling (BGI, 2012). Afterwards the 3D load distribution has been calculated using a 3D finite element method. Our results show that the North Alpine Foreland Basin is not isostatically balanced and that the configuration of the crystalline crust strongly controls the gravity field in this area. Furthermore, our results show that the basin area is influenced by varying lateral load differences down to a depth of more than 150 km what allows a first order statement of the required compensating horizontal stress needed to prevent gravitational collapse of the system. BGI (2012). The International

  3. 3D reconstruction and spatial auralization of the "Painted Dolmen" of Antelas

    NASA Astrophysics Data System (ADS)

    Dias, Paulo; Campos, Guilherme; Santos, Vítor; Casaleiro, Ricardo; Seco, Ricardo; Sousa Santos, Beatriz

    2008-02-01

    This paper presents preliminary results on the development of a 3D audiovisual model of the Anta Pintada (painted dolmen) of Antelas, a Neolithic chamber tomb located in Oliveira de Frades and listed as Portuguese national monument. The final aim of the project is to create a highly accurate Virtual Reality (VR) model of this unique archaeological site, capable of providing not only visual but also acoustic immersion based on its actual geometry and physical properties. The project started in May 2006 with in situ data acquisition. The 3D geometry of the chamber was captured using a Laser Range Finder. In order to combine the different scans into a complete 3D visual model, reconstruction software based on the Iterative Closest Point (ICP) algorithm was developed using the Visualization Toolkit (VTK). This software computes the boundaries of the room on a 3D uniform grid and populates its interior with "free-space nodes", through an iterative algorithm operating like a torchlight illuminating a dark room. The envelope of the resulting set of "free-space nodes" is used to generate a 3D iso-surface approximating the interior shape of the chamber. Each polygon of this surface is then assigned the acoustic absorption coefficient of the corresponding boundary material. A 3D audiovisual model operating in real-time was developed for a VR Environment comprising head-mounted display (HMD) I-glasses SVGAPro, an orientation sensor (tracker) InterTrax 2 with 3 Degrees Of Freedom (3DOF) and stereo headphones. The auralisation software is based on a geometric model. This constitutes a first approach, since geometric acoustics have well-known limitations in rooms with irregular surfaces. The immediate advantage lies in their inherent computational efficiency, which allows real-time operation. The program computes the early reflections forming the initial part of the chamber's impulse response (IR), which carry the most significant cues for source localisation. These early

  4. Probability distribution functions for cover used in 3-D model simulating concrete deterioration in port assets.

    NASA Astrophysics Data System (ADS)

    Homer, Rachel M.; Law, David W.; Molyneaux, Thomas C. K.

    2015-07-01

    In previous studies, a 1-D numerical predictive tool to simulate the salt induced corrosion of port assets in Australia has been developed into a 2-D and 3-D model based on current predictive probabilistic models. These studies use a probability distribution function based on the mean and standard deviation of the parameters for a structure incorporating surface chloride concentration, diffusion coefficient and cover. In this paper, this previous work is extended through an investigation of the distribution of actual cover by specified cover, element type and method of construction. Significant differences are found for the measured cover within structures, by method of construction, element type and specified cover. The data are not normally distributed and extreme values, usually low, are found in a number of locations. Elements cast insitu are less likely to meet the specified cover and the measured cover is more dispersed than those in elements which are precast. Individual probability distribution functions are available and are tested against the original function. Methods of combining results so that one distribution is available for a structure are formulated and evaluated. The ability to utilise the model for structures where no measurement have been taken is achieved by transposing results based on the specified cover.

  5. Dose distribution and mapping with 3D imaging presentation in intraoral and panoramic examinations

    NASA Astrophysics Data System (ADS)

    Chen, Hsiu-Ling; Huang, Yung-Hui; Wu, Tung-Hsin; Wang, Shih-Yuan; Lee, Jason J. S.

    2011-10-01

    In current medical imaging applications, high quality images not only provide more diagnostic value for anatomic delineation but also offer functional information for treatment direction. However, this approach would potentially subscribe higher radiation dose in dental radiographies, which has been putatively associated with low-birth-weight during pregnancy, which affects the hypothalamus-pituitary-thyroid axis or thereby directly affects the reproductive organs. The aim of this study was to apply the high resolution 3-D image mapping technique to evaluate radiation doses from the following aspects: (1) verifying operating parameters of dental X-ray units, (2) measuring the leakage radiations and (3) mapping dose with 3-D radiographic imaging to evaluate dose distribution in head and neck regions. From the study results, we found that (1) leakage radiation from X-ray units was about 21.31±15.24 mR/h (<100 mR/h), (2) error of actual tube voltage for 60 kVp setting was from 0.2% to 6.5%, with an average of 2.5% (<7%) and (3) the error of exposure time for a 0.5-1.5 s setting was within 0.7-8.5%, with an average of 7.3% (<10%) error as well. Our 3-D dose mapping demonstrated that dose values were relatively lower in soft tissues and higher in bone surfaces compared with other investigations. Multiple causes could contribute to these variations, including irradiation geometry, image equipment and type of technique applied, etc. From the results, we also observed that larger accumulated doses were presented in certain critical organs, such as salivary gland, thyroid gland and bone marrow. Potential biological affects associated with these findings warrant further investigation.

  6. Pseudo-3D PIC modeling of drift-induced spatial inhomogeneities in planar magnetron plasmas

    NASA Astrophysics Data System (ADS)

    Revel, A.; Minea, T.; Tsikata, S.

    2016-10-01

    A pseudo-3D modeling approach, based on a particle-in-cell (PIC)-Monte Carlo collisions algorithm, has been developed for the study of large- and short-scale organization of the plasma in a planar magnetron. This extension of conventional PIC modeling permits the observation of spontaneous organization of the magnetron plasma, under the influence of crossed electric and magnetic fields, into the well-known, large-scale regions of enhanced ionization and density known as spokes. The nature of complex three-dimensional electron trajectories around such structures, and non-uniform ionization within them, is revealed. This modeling provides direct numerical evidence for the existence of high-amplitude internal spoke electric fields, proposed in earlier works. A 3D phenomenological model, consistent with numerical results, is proposed. Electron density fluctuations in the megahertz range, with characteristics similar to the electron cyclotron drift instability experimentally identified in a recent Letter, are also found.

  7. A graphical user interface for calculation of 3D dose distribution using Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Chow, J. C. L.; Leung, M. K. K.

    2008-02-01

    A software graphical user interface (GUI) for calculation of 3D dose distribution using Monte Carlo (MC) simulation is developed using MATLAB. This GUI (DOSCTP) provides a user-friendly platform for DICOM CT-based dose calculation using EGSnrcMP-based DOSXYZnrc code. It offers numerous features not found in DOSXYZnrc, such as the ability to use multiple beams from different phase-space files, and has built-in dose analysis and visualization tools. DOSCTP is written completely in MATLAB, with integrated access to DOSXYZnrc and CTCREATE. The program function may be divided into four subgroups, namely, beam placement, MC simulation with DOSXYZnrc, dose visualization, and export. Each is controlled by separate routines. The verification of DOSCTP was carried out by comparing plans with different beam arrangements (multi-beam/photon arc) on an inhomogeneous phantom as well as patient CT between the GUI and Pinnacle3. DOSCTP was developed and verified with the following features: (1) a built-in voxel editor to modify CT-based DOSXYZnrc phantoms for research purposes; (2) multi-beam placement is possible, which cannot be achieved using the current DOSXYZnrc code; (3) the treatment plan, including the dose distributions, contours and image set can be exported to a commercial treatment planning system such as Pinnacle3 or to CERR using RTOG format for plan evaluation and comparison; (4) a built-in RTOG-compatible dose reviewer for dose visualization and analysis such as finding the volume of hot/cold spots in the 3D dose distributions based on a user threshold. DOSCTP greatly simplifies the use of DOSXYZnrc and CTCREATE, and offers numerous features that not found in the original user-code. Moreover, since phase-space beams can be defined and generated by the user, it is a particularly useful tool to carry out plans using specifically designed irradiators/accelerators that cannot be found in the Linac library of commercial treatment planning systems.

  8. Local ISM 3D Distribution and Soft X-ray Background Inferences for Nearby Hot Gas

    NASA Technical Reports Server (NTRS)

    Puspitarini, L.; Lallement, R.; Snowden, Steven L.; Vergely, J.-L.; Snowden, S.

    2014-01-01

    Three-dimensional (3D) interstellar medium (ISM) maps can be used to locate not only interstellar (IS) clouds, but also IS bubbles between the clouds that are blown by stellar winds and supernovae, and are filled by hot gas. To demonstrate this, and to derive a clearer picture of the local ISM, we compare our recent 3D IS dust distribution maps to the ROSAT diffuse Xray background maps after removal of heliospheric emission. In the Galactic plane, there is a good correspondence between the locations and extents of the mapped nearby cavities and the soft (0.25 keV) background emission distribution, showing that most of these nearby cavities contribute to this soft X-ray emission. Assuming a constant dust to gas ratio and homogeneous 106 K hot gas filling the cavities, we modeled in a simple way the 0.25 keV surface brightness along the Galactic plane as seen from the Sun, taking into account the absorption by the mapped clouds. The data-model comparison favors the existence of hot gas in the solar neighborhood, the so-called Local Bubble (LB). The inferred mean pressure in the local cavities is found to be approx.9,400/cu cm K, in agreement with previous studies, providing a validation test for the method. On the other hand, the model overestimates the emission from the huge cavities located in the third quadrant. Using CaII absorption data, we show that the dust to CaII ratio is very small in those regions, implying the presence of a large quantity of lower temperature (non-X-ray emitting) ionized gas and as a consequence a reduction of the volume filled by hot gas, explaining at least part of the discrepancy. In the meridian plane, the two main brightness enhancements coincide well with the LB's most elongated parts and chimneys connecting the LB to the halo, but no particular nearby cavity is found towards the enhancement in the direction of the bright North Polar Spur (NPS) at high latitude. We searched in the 3D maps for the source regions of the higher energy

  9. The variants of an LOD of a 3D building model and their influence on spatial analyses

    NASA Astrophysics Data System (ADS)

    Biljecki, Filip; Ledoux, Hugo; Stoter, Jantien; Vosselman, George

    2016-06-01

    The level of detail (LOD) of a 3D city model indicates the model's grade and usability. However, there exist multiple valid variants of each LOD. As a consequence, the LOD concept is inconclusive as an instruction for the acquisition of 3D city models. For instance, the top surface of an LOD1 block model may be modelled at the eaves of a building or at its ridge height. Such variants, which we term geometric references, are often overlooked and are usually not documented in the metadata. Furthermore, the influence of a particular geometric reference on the performance of a spatial analysis is not known. In response to this research gap, we investigate a variety of LOD1 and LOD2 geometric references that are commonly employed, and perform numerical experiments to investigate their relative difference when used as input for different spatial analyses. We consider three use cases (estimation of the area of the building envelope, building volume, and shadows cast by buildings), and compute the deviations in a Monte Carlo simulation. The experiments, carried out with procedurally generated models, indicate that two 3D models representing the same building at the same LOD, but modelled according to different geometric references, may yield substantially different results when used in a spatial analysis. The outcome of our experiments also suggests that the geometric reference may have a bigger influence than the LOD, since an LOD1 with a specific geometric reference may yield a more accurate result than when using LOD2 models.

  10. The distribution of 3D superconductivity near the second critical field

    NASA Astrophysics Data System (ADS)

    Kachmar, Ayman; Nasrallah, Marwa

    2016-09-01

    We study the minimizers of the Ginzburg-Landau energy functional with a uniform magnetic field in a three dimensional bounded domain. The functional depends on two positive parameters, the Ginzburg-Landau parameter and the intensity of the applied magnetic field, and acts on complex-valued functions and vector fields. We establish a formula for the distribution of the L 2-norm of the minimizing complex-valued function (order parameter). The formula is valid in the regime where the Ginzburg-Landau parameter is large and the applied magnetic field is close to and strictly below the second critical field—the threshold value corresponding to the transition from the superconducting to the normal phase in the bulk of the sample. Earlier results are valid in 2D domains and for the L 4-norm in 3D domains.

  11. Measurement of carbon ion microdosimetric distributions with ultrathin 3D silicon diodes

    NASA Astrophysics Data System (ADS)

    Gómez, F.; Fleta, C.; Esteban, S.; Quirion, D.; Pellegrini, G.; Lozano, M.; Prezado, Y.; Dos Santos, M.; Guardiola, C.; Montarou, G.; Prieto-Pena, J.; Pardo-Montero, Juan

    2016-06-01

    The commissioning of an ion beam for hadrontherapy requires the evaluation of the biologically weighted effective dose that results from the microdosimetric properties of the therapy beam. The spectra of the energy imparted at cellular and sub-cellular scales are fundamental to the determination of the biological effect of the beam. These magnitudes are related to the microdosimetric distributions of the ion beam at different points along the beam path. This work is dedicated to the measurement of microdosimetric spectra at several depths in the central axis of a 12C beam with an energy of 94.98 AMeV using a novel 3D ultrathin silicon diode detector. Data is compared with Monte Carlo calculations providing an excellent agreement (deviations are less than 2% for the most probable lineal energy value) up to the Bragg peak. The results show the feasibility to determine with high precision the lineal energy transfer spectrum of a hadrontherapy beam with these silicon devices.

  12. Measurement of carbon ion microdosimetric distributions with ultrathin 3D silicon diodes.

    PubMed

    Gómez, F; Fleta, C; Esteban, S; Quirion, D; Pellegrini, G; Lozano, M; Prezado, Y; Dos Santos, M; Guardiola, C; Montarou, G; Prieto-Pena, J; Pardo-Montero, Juan

    2016-06-07

    The commissioning of an ion beam for hadrontherapy requires the evaluation of the biologically weighted effective dose that results from the microdosimetric properties of the therapy beam. The spectra of the energy imparted at cellular and sub-cellular scales are fundamental to the determination of the biological effect of the beam. These magnitudes are related to the microdosimetric distributions of the ion beam at different points along the beam path. This work is dedicated to the measurement of microdosimetric spectra at several depths in the central axis of a (12)C beam with an energy of 94.98 AMeV using a novel 3D ultrathin silicon diode detector. Data is compared with Monte Carlo calculations providing an excellent agreement (deviations are less than 2% for the most probable lineal energy value) up to the Bragg peak. The results show the feasibility to determine with high precision the lineal energy transfer spectrum of a hadrontherapy beam with these silicon devices.

  13. A novel time dependent gamma evaluation function for dynamic 2D and 3D dose distributions.

    PubMed

    Podesta, Mark; Persoon, Lucas C G G; Verhaegen, Frank

    2014-10-21

    Modern external beam radiotherapy requires detailed verification and quality assurance so that confidence can be placed on both the delivery of a single treatment fraction and on the consistency of delivery throughout the treatment course. To verify dose distributions, a comparison between prediction and measurement must be made. Comparisons between two dose distributions are commonly performed using a Gamma evaluation which is a calculation of two quantities on a pixel by pixel basis; the dose difference, and the distance to agreement. By providing acceptance criteria (e.g. 3%, 3 mm), the function will find the most appropriate match within its two degrees of freedom. For complex dynamic treatments such as IMRT or VMAT it is important to verify the dose delivery in a time dependent manner and so a gamma evaluation that includes a degree of freedom in the time domain via a third parameter, time to agreement, is presented here. A C++ (mex) based gamma function was created that could be run on either CPU and GPU computing platforms that would allow a degree of freedom in the time domain. Simple test cases were created in both 2D and 3D comprising of simple geometrical shapes with well-defined boundaries varying over time. Changes of varying magnitude in either space or time were introduced and repeated gamma analyses were performed varying the criteria. A clinical VMAT case was also included, artificial air bubbles of varying size were introduced to a patient geometry, along with shifts of varying magnitude in treatment time. For all test cases where errors in distance, dose or time were introduced, the time dependent gamma evaluation could accurately highlight the errors.The time dependent gamma function presented here allows time to be included as a degree of freedom in gamma evaluations. The function allows for 2D and 3D data sets which are varying over time to be compared using appropriate criteria without penalising minor offsets of subsequent radiation fields

  14. Inverse modeling of InSAR and ground leveling data for 3D volumetric strain distribution

    NASA Astrophysics Data System (ADS)

    Gallardo, L. A.; Glowacka, E.; Sarychikhina, O.

    2015-12-01

    Wide availability of modern Interferometric Synthetic aperture Radar (InSAR) data have made possible the extensive observation of differential surface displacements and are becoming an efficient tool for the detailed monitoring of terrain subsidence associated to reservoir dynamics, volcanic deformation and active tectonism. Unfortunately, this increasing popularity has not been matched by the availability of automated codes to estimate underground deformation, since many of them still rely on trial-error subsurface model building strategies. We posit that an efficient algorithm for the volumetric modeling of differential surface displacements should match the availability of current leveling and InSAR data and have developed an algorithm for the joint inversion of ground leveling and dInSAR data in 3D. We assume the ground displacements are originated by a stress free-volume strain distribution in a homogeneous elastic media and determined the displacement field associated to an ensemble of rectangular prisms. This formulation is then used to develop a 3D conjugate gradient inversion code that searches for the three-dimensional distribution of the volumetric strains that predict InSAR and leveling surface displacements simultaneously. The algorithm is regularized applying discontinuos first and zero order Thikonov constraints. For efficiency, the resulting computational code takes advantage of the resulting convolution integral associated to the deformation field and some basic tools for multithreading parallelization. We extensively test our algorithm on leveling and InSAR test and field data of the Northwest of Mexico and compare to some feasible geological scenarios of underground deformation.

  15. The ATLAS 3D project - XXIV. The intrinsic shape distribution of early-type galaxies

    NASA Astrophysics Data System (ADS)

    Weijmans, Anne-Marie; de Zeeuw, P. T.; Emsellem, Eric; Krajnović, Davor; Lablanche, Pierre-Yves; Alatalo, Katherine; Blitz, Leo; Bois, Maxime; Bournaud, Frédéric; Bureau, Martin; Cappellari, Michele; Crocker, Alison F.; Davies, Roger L.; Davis, Timothy A.; Duc, Pierre-Alain; Khochfar, Sadegh; Kuntschner, Harald; McDermid, Richard M.; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Sarzi, Marc; Scott, Nicholas; Serra, Paolo; Verdoes Kleijn, Gijs; Young, Lisa M.

    2014-11-01

    We use the ATLAS3D sample to perform a study of the intrinsic shapes of early-type galaxies, taking advantage of the available combined photometric and kinematic data. Based on our ellipticity measurements from the Sloan Digital Sky Survey Data Release 7, and additional imaging from the Isaac Newton Telescope, we first invert the shape distribution of fast and slow rotators under the assumption of axisymmetry. The so-obtained intrinsic shape distribution for the fast rotators can be described with a Gaussian with a mean flattening of q = 0.25 and standard deviation σq = 0.14, and an additional tail towards rounder shapes. The slow rotators are much rounder, and are well described with a Gaussian with mean q = 0.63 and σq = 0.09. We then checked that our results were consistent when applying a different and independent method to obtain intrinsic shape distributions, by fitting the observed ellipticity distributions directly using Gaussian parametrizations for the intrinsic axis ratios. Although both fast and slow rotators are identified as early-type galaxies in morphological studies, and in many previous shape studies are therefore grouped together, their shape distributions are significantly different, hinting at different formation scenarios. The intrinsic shape distribution of the fast rotators shows similarities with the spiral galaxy population. Including the observed kinematic misalignment in our intrinsic shape study shows that the fast rotators are predominantly axisymmetric, with only very little room for triaxiality. For the slow rotators though there are very strong indications that they are (mildly) triaxial.

  16. New insights in catchment processes via distributed soil moisture measurements and 3D hydrological modeling

    NASA Astrophysics Data System (ADS)

    Bogena, H. R.; Sciuto, G.; Rosenbaum, U.; Herbst, M.; Huisman, J. A.; Vereecken, H.; Diekkrueger, B.

    2010-12-01

    Hydrological analysis is often limited by the number of data available. Usually, discharge data and only little point information concerning soil moisture status are available. This might give a good representation of the temporal variability of runoff, but it does not provide insights into the spatial dynamics of soil moisture and water fluxes within the catchment. The small forested Wüstebach catchment (~27 ha) has been instrumented with a wireless sensor network consisting of 150 nodes and more than 1200 soil moisture sensors in the framework of the Transregio32 and the Helmholtz initiative TERENO (Terrestrial Environmental Observatories) [1]. This unique data set provides a consistent picture of the hydrological status of the catchment in a high spatial and temporal resolution. We present first results of a geostatistical analysis of the data and an application of the integrated surface/subsurface 3D finite element model HydroGeoSphere model to investigate the scale dependency of the temporal dynamics of soil moisture patterns. A variogram analysis showed that the sum of the sub-scale variability and the measurement error is close to time-invariant. Wet situations showed smaller spatial variability, which is attributed to saturated soil moisture, which poses an upper limit and is typically not strongly variable in headwater catchments with relatively homogeneous soil. The spatiotemporal variability in soil moisture at 50 cm depth was significantly lower than at 5 and 20 cm. This finding indicates that the considerable variability of the top soil is buffered deeper in the soil due to root water uptake, lateral and vertical water fluxes. Topographic features showed the strongest correlation with soil moisture during dry periods, indicating that the control of topography on the soil moisture pattern depends on the soil water status. The temporal patterns of runoff discharge were reproduced by the HydroGeoSphere model in a satisfying way. The observed soil

  17. The 3D distribution of cordierite and biotite in hornfels from the Bugaboo contact aureole (British Columbia, Canada)

    NASA Astrophysics Data System (ADS)

    Gaidies, Fred; Petley-Ragan, Arianne; Pattison, David

    2016-04-01

    The size, abundance, shape and spatial distribution of metamorphic minerals bears important information on the rates and mechanisms of fundamental processes that take place during metamorphic crystallization. X-ray computed tomography (XR-CT) has become the method of choice to study the three-dimensional (3D) disposition of minerals in rocks as it allows investigation of relatively large sample volumes at sufficiently high resolution required for statistically meaningful analyses, and as its non-destructive fashion permits further studies such as mineral chemical, isotopic or crystallographic analyses of select grains identified through XR-CT. We present results obtained through the quantification of the 3D disposition of cordierite and biotite crystals in a hornfels from the contact aureole of the Bugaboo Batholith (British Columbia, Canada) using XR-CT and global as well as scale-dependent pattern statistics (Petley-Ragan et al., 2016). The results demonstrate a random distribution of cordierite and biotite crystal sizes for all scales across the entire rock volume studied indicative of interface-controlled prograde metamorphic reaction kinetics. We show that the common approach to approximate the shape of crystals as spherical underestimates the influence of the Strauss hard-core process on rock texture which may be misinterpreted to reflect ordering of crystal sizes by inhibition of nucleation and growth commonly associated with diffusion-controlled reaction kinetics. According to our findings, Strauss hard-core ordering develops at length scales equal to and less than the average major axis of the crystal population. This is significantly larger than what is obtained if a spherical crystal geometry would be assumed, and increases with deviation from sphericity. For the cordierite and biotite populations investigated in this research, Strauss hard-core ordering developed at length scales of up to ˜2.2 and 1.25 mm, respectively, which is almost 1 mm longer than

  18. 3D dose and TCP distribution for radionuclide therapy in nuclear medicine

    NASA Astrophysics Data System (ADS)

    Valente, M.; Malano, F.; Pérez, P.

    2010-08-01

    A common feature to any radiant therapy is that lesion and health tissue dosimetry provides relevant information for treatment optimization along with dose-efficacy and dose-complication correlation studies. Nowadays, different radionuclide therapies are commonly available, assessing both systemic and loco-regional approach and using different alfa-, beta-and gamma-emitting isotopes and binding molecules. It is well established, that specific dosimetric approaches become necessary according to each therapy modality. Sometimes, observed activity distribution can be satisfactory represented by simple geometrical models. However, Monte Carlo techniques are capable of better approaches, therefore becoming sometimes the only way to get dosimetric data since the patient-specific situation can not be adequately represented by conventional dosimetry techniques. Therefore, due to strong limitations of traditional and standard methods, this work concentrates on the development of a dedicated and novel calculation system in order to assess the dose distribution within the irradiated patient. However, physical dose may not be enough information in order to establish real deterministic biological/metabolic effects; therefore complementary radiobiological models have been suitably introduced with the aim of performing realistic 3D dose as well as corresponding Tumor Control Probability distribution calculation.

  19. Stability and 3-D spatial dynamics analysis of a three cable crane

    NASA Technical Reports Server (NTRS)

    Yang, Li-Farn; Mikulas, Martin M., Jr.; Chiou, Jin-Chern

    1992-01-01

    A 3-cable crane mechanism has been designed for incorporation into a highly loaded Lunar crane for planetary construction. This 3-cable crane must maintain a positive stability margin in all phases of the loading/unloading, assembly, or installation operations. A 2D kinematic curvature theory is applied to: (1) derive a general stability criterion to prevent the 3-cable crane from instability; and (2) determine a simple equation of natural frequency for two planar models of 3-cable crane. Investigation of the 2D vibrational characteristics of the planar models provides valuable insight toward understanding of 3D dynamic behavior of the 3-cable crane. Also, precision in natural frequency from this simple kinematic equation due to the exclusion of the radius-of-gyration of a suspended article is discussed. Multibody dynamics of the 3D 3-cable crane is presented and simulated to study the resulting vibrational characteristics under external disturbances and to verify the feasibility of the stability criterion for the 3-cable crane.

  20. 3-D spatial chaos in the elastica and the spinning top: Kirchhoff analogy.

    PubMed

    Davies, M. A.; Moon, F. C.

    1993-01-01

    The existence of spatially chaotic deformations in an elastica and the analogous motions of a free spinning rigid body, an extension of the problem originally examined by Kirchhoff are investigated. It is shown that a spatially periodic variation in cross sectional area of the elastica results in spatially complex deformation patterns. The governing equations for the elastica were numerically integrated and Poincare maps were created for a number of different initial conditions. In addition, three dimensional computer images of the twisted elastica were generated to illustrate periodic, quasiperiodic, and stochastic deformation patterns in space. These pictures clearly show the existence of spatially chaotic deformations with stunning complexity. This finding is relevant to a wide variety of fields in which coiled structures are important, from the modeling of DNA chains to video and audio tape dynamics to the design of deployable space structures.

  1. Regularization Designs for Uniform Spatial Resolution and Noise Properties in Statistical Image Reconstruction for 3D X-ray CT

    PubMed Central

    Cho, Jang Hwan; Fessler, Jeffrey A.

    2014-01-01

    Statistical image reconstruction methods for X-ray computed tomography (CT) provide improved spatial resolution and noise properties over conventional filtered back-projection (FBP) reconstruction, along with other potential advantages such as reduced patient dose and artifacts. Conventional regularized image reconstruction leads to spatially variant spatial resolution and noise characteristics because of interactions between the system models and the regularization. Previous regularization design methods aiming to solve such issues mostly rely on circulant approximations of the Fisher information matrix that are very inaccurate for undersampled geometries like short-scan cone-beam CT. This paper extends the regularization method proposed in [1] to 3D cone-beam CT by introducing a hypothetical scanning geometry that helps address the sampling properties. The proposed regularization designs were compared with the original method in [1] with both phantom simulation and clinical reconstruction in 3D axial X-ray CT. The proposed regularization methods yield improved spatial resolution or noise uniformity in statistical image reconstruction for short-scan axial cone-beam CT. PMID:25361500

  2. Regularization designs for uniform spatial resolution and noise properties in statistical image reconstruction for 3-D X-ray CT.

    PubMed

    Cho, Jang Hwan; Fessler, Jeffrey A

    2015-02-01

    Statistical image reconstruction methods for X-ray computed tomography (CT) provide improved spatial resolution and noise properties over conventional filtered back-projection (FBP) reconstruction, along with other potential advantages such as reduced patient dose and artifacts. Conventional regularized image reconstruction leads to spatially variant spatial resolution and noise characteristics because of interactions between the system models and the regularization. Previous regularization design methods aiming to solve such issues mostly rely on circulant approximations of the Fisher information matrix that are very inaccurate for undersampled geometries like short-scan cone-beam CT. This paper extends the regularization method proposed in to 3-D cone-beam CT by introducing a hypothetical scanning geometry that helps address the sampling properties. The proposed regularization designs were compared with the original method in with both phantom simulation and clinical reconstruction in 3-D axial X-ray CT. The proposed regularization methods yield improved spatial resolution or noise uniformity in statistical image reconstruction for short-scan axial cone-beam CT.

  3. The Radial Distribution of Star Formation in Galaxies at Z approximately 1 from the 3D-HST Survey

    NASA Technical Reports Server (NTRS)

    Nelson, Erica June; vanDokkum, Pieter G.; Momcheva, Ivelina; Brammer, Gabriel; Lundgren, Britt; Skelton, Rosalind E.; Whitaker, Katherine E.; DaCunha, Elisabete; Schreiber, Natascha Foerster; Franx, Marijn; Fumagalli, Mattia; Kriek, Mariska; Labbe, Ivo; Leja, Joel; Patel, Shannon; Rix, Hans-Walter; Schmidt, Kasper B.; vanderWel, Argen; Wuyts, Stijn

    2013-01-01

    The assembly of galaxies can be described by the distribution of their star formation as a function of cosmic time. Thanks to the WFC3 grism on the Hubble Space Telescope (HST) it is now possible to measure this beyond the local Universe. Here we present the spatial distribution of H emission for a sample of 54 strongly star-forming galaxies at z 1 in the 3D-HST Treasury survey. By stacking the H emission, we find that star formation occurred in approximately exponential distributions at z approximately 1, with a median Sersic index of n = 1.0 +/- 0.2. The stacks are elongated with median axis ratios of b/a = 0.58 +/- 0.09 in H consistent with (possibly thick) disks at random orientation angles. Keck spectra obtained for a subset of eight of the galaxies show clear evidence for rotation, with inclination corrected velocities of 90.330 km s(exp 1-). The most straightforward interpretation of our results is that star formation in strongly star-forming galaxies at z approximately 1 generally occurred in disks. The disks appear to be scaled-up versions of nearby spiral galaxies: they have EW(H alpha) at approximately 100 A out to the solar orbit and they have star formation surface densities above the threshold for driving galactic scale winds.

  4. The Radial Distribution of Star Formation in Galaxies at z1 From The 3D-HST Survey

    NASA Technical Reports Server (NTRS)

    Nelson, Erica June; Dokkum, Pieter G. Van; Momcheva, Ivelina; Brammer, Gabriel; Lundgren, Britt; Skelton, Rosalind E.; Tease, Katherine Whitaker; Cunha, Elisabete Da; Schreiber, Natascha Forster; Franx, Marijn; Fumagalli, Mattia; Kriek, Mariska; Labbe, Ivo; Leja, Joel; Patel, Shannon; Rix, Hans-Walter; Schmidt, Kasper B.; Wel, Arjen Van Der; Wuyts, Stijn

    2013-01-01

    The assembly of galaxies can be described by the distribution of their star formation as a function of cosmic time.Thanks to the WFC3 grism on the Hubble Space Telescope (HST) it is now possible to measure this beyond thelocal Universe. Here we present the spatial distribution of H emission for a sample of 54 strongly star-forming-galaxies at z1 in the 3D-HST Treasury survey. By stacking the Halpha emission, we find that star formation occurredin approximately exponential distributions at z1, with a median Sersic index of n=1.0 plus or minus 0.2. The stacks areelongated with median axis ratios of b/a 0.58 plus or minus 0.09 in Halpha consistent with (possibly thick) disks at randomorientation angles. Keck spectra obtained for a subset of eight of the galaxies show clear evidence for rotation, withinclination corrected velocities of 90-330 km per second. The most straightforward interpretation of our results is that starformation in strongly star-forming galaxies at z1 generally occurred in disks. The disks appear to be scaled-upversions of nearby spiral galaxies: they have EW(Halpha)100 Angstroms out to the solar orbit and they have star formation surface densities above the threshold for driving galactic scale winds.

  5. THE RADIAL DISTRIBUTION OF STAR FORMATION IN GALAXIES AT z {approx} 1 FROM THE 3D-HST SURVEY

    SciTech Connect

    Nelson, Erica June; Van Dokkum, Pieter G.; Momcheva, Ivelina; Skelton, Rosalind E.; Leja, Joel; Brammer, Gabriel; Lundgren, Britt; Whitaker, Katherine E.; Da Cunha, Elisabete; Rix, Hans-Walter; Van der Wel, Arjen; Foerster Schreiber, Natascha; Wuyts, Stijn; Franx, Marijn; Fumagalli, Mattia; Labbe, Ivo; Patel, Shannon; Kriek, Mariska; Schmidt, Kasper B.

    2013-01-20

    The assembly of galaxies can be described by the distribution of their star formation as a function of cosmic time. Thanks to the WFC3 grism on the Hubble Space Telescope (HST) it is now possible to measure this beyond the local Universe. Here we present the spatial distribution of H{alpha} emission for a sample of 54 strongly star-forming galaxies at z {approx} 1 in the 3D-HST Treasury survey. By stacking the H{alpha} emission, we find that star formation occurred in approximately exponential distributions at z {approx} 1, with a median Sersic index of n = 1.0 {+-} 0.2. The stacks are elongated with median axis ratios of b/a = 0.58 {+-} 0.09 in H{alpha} consistent with (possibly thick) disks at random orientation angles. Keck spectra obtained for a subset of eight of the galaxies show clear evidence for rotation, with inclination corrected velocities of 90-330 km s{sup -1}. The most straightforward interpretation of our results is that star formation in strongly star-forming galaxies at z {approx} 1 generally occurred in disks. The disks appear to be 'scaled-up' versions of nearby spiral galaxies: they have EW(H{alpha}) {approx} 100 A out to the solar orbit and they have star formation surface densities above the threshold for driving galactic scale winds.

  6. Novel methods for estimating 3D distributions of radioactive isotopes in materials

    NASA Astrophysics Data System (ADS)

    Iwamoto, Y.; Kataoka, J.; Kishimoto, A.; Nishiyama, T.; Taya, T.; Okochi, H.; Ogata, H.; Yamamoto, S.

    2016-09-01

    In recent years, various gamma-ray visualization techniques, or gamma cameras, have been proposed. These techniques are extremely effective for identifying "hot spots" or regions where radioactive isotopes are accumulated. Examples of such would be nuclear-disaster-affected areas such as Fukushima or the vicinity of nuclear reactors. However, the images acquired with a gamma camera do not include distance information between radioactive isotopes and the camera, and hence are "degenerated" in the direction of the isotopes. Moreover, depth information in the images is lost when the isotopes are embedded in materials, such as water, sand, and concrete. Here, we propose two methods of obtaining depth information of radioactive isotopes embedded in materials by comparing (1) their spectra and (2) images of incident gamma rays scattered by the materials and direct gamma rays. In the first method, the spectra of radioactive isotopes and the ratios of scattered to direct gamma rays are obtained. We verify experimentally that the ratio increases with increasing depth, as predicted by simulations. Although the method using energy spectra has been studied for a long time, an advantage of our method is the use of low-energy (50-150 keV) photons as scattered gamma rays. In the second method, the spatial extent of images obtained for direct and scattered gamma rays is compared. By performing detailed Monte Carlo simulations using Geant4, we verify that the spatial extent of the position where gamma rays are scattered increases with increasing depth. To demonstrate this, we are developing various gamma cameras to compare low-energy (scattered) gamma-ray images with fully photo-absorbed gamma-ray images. We also demonstrate that the 3D reconstruction of isotopes/hotspots is possible with our proposed methods. These methods have potential applications in the medical fields, and in severe environments such as the nuclear-disaster-affected areas in Fukushima.

  7. Quantification of spatial structure of human proximal tibial bone biopsies using 3D measures of complexity

    NASA Astrophysics Data System (ADS)

    Saparin, Peter I.; Skovhus Thomsen, Jesper; Prohaska, Steffen; Zaikin, Alexei; Kurths, Jürgen; Hege, Hans-Christian; Gowin, Wolfgang

    2005-05-01

    Changes in trabecular bone composition during development of osteoporosis are used as a model for bone loss in microgravity conditions during a space flight. Symbolic dynamics and measures of complexity are proposed and applied to assess quantitatively the structural composition of bone tissue from 3D data sets of human tibia bone biopsies acquired by a micro-CT scanner. In order to justify the newly proposed approach, the measures of complexity of the bone architecture were compared with the results of traditional 2D bone histomorphometry. The proposed technique is able to quantify the structural loss of the bone tissue and may help to diagnose and to monitor changes in bone structure of patients on Earth as well as of the space-flying personnel.

  8. Enabling 3D-Liver Perfusion Mapping from MR-DCE Imaging Using Distributed Computing.

    PubMed

    Leporq, Benjamin; Camarasu-Pop, Sorina; Davila-Serrano, Eduardo E; Pilleul, Frank; Beuf, Olivier

    2013-01-01

    An MR acquisition protocol and a processing method using distributed computing on the European Grid Infrastructure (EGI) to allow 3D liver perfusion parametric mapping after Magnetic Resonance Dynamic Contrast Enhanced (MR-DCE) imaging are presented. Seven patients (one healthy control and six with chronic liver diseases) were prospectively enrolled after liver biopsy. MR-dynamic acquisition was continuously performed in free-breathing during two minutes after simultaneous intravascular contrast agent (MS-325 blood pool agent) injection. Hepatic capillary system was modeled by a 3-parameters one-compartment pharmacokinetic model. The processing step was parallelized and executed on the EGI. It was modeled and implemented as a grid workflow using the Gwendia language and the MOTEUR workflow engine. Results showed good reproducibility in repeated processing on the grid. The results obtained from the grid were well correlated with ROI-based reference method ran locally on a personal computer. The speed-up range was 71 to 242 with an average value of 126. In conclusion, distributed computing applied to perfusion mapping brings significant speed-up to quantification step to be used for further clinical studies in a research context. Accuracy would be improved with higher image SNR accessible on the latest 3T MR systems available today.

  9. Intensifying the response of distributed optical fibre sensors using 2D and 3D image restoration

    PubMed Central

    Soto, Marcelo A.; Ramírez, Jaime A.; Thévenaz, Luc

    2016-01-01

    Distributed optical fibre sensors possess the unique capability of measuring the spatial and temporal map of environmental quantities that can be of great interest for several field applications. Although existing methods for performance enhancement have enabled important progresses in the field, they do not take full advantage of all information present in the measured data, still giving room for substantial improvement over the state-of-the-art. Here we propose and experimentally demonstrate an approach for performance enhancement that exploits the high level of similitude and redundancy contained on the multidimensional information measured by distributed fibre sensors. Exploiting conventional image and video processing, an unprecedented boost in signal-to-noise ratio and measurement contrast is experimentally demonstrated. The method can be applied to any white-noise-limited distributed fibre sensor and can remarkably provide a 100-fold improvement in the sensor performance with no hardware modification. PMID:26927698

  10. Cardiac C-arm computed tomography using a 3D + time ROI reconstruction method with spatial and temporal regularization

    SciTech Connect

    Mory, Cyril; Auvray, Vincent; Zhang, Bo; Grass, Michael; Schäfer, Dirk; Chen, S. James; Carroll, John D.; Rit, Simon; Peyrin, Françoise; Douek, Philippe; Boussel, Loïc

    2014-02-15

    Purpose: Reconstruction of the beating heart in 3D + time in the catheter laboratory using only the available C-arm system would improve diagnosis, guidance, device sizing, and outcome control for intracardiac interventions, e.g., electrophysiology, valvular disease treatment, structural or congenital heart disease. To obtain such a reconstruction, the patient's electrocardiogram (ECG) must be recorded during the acquisition and used in the reconstruction. In this paper, the authors present a 4D reconstruction method aiming to reconstruct the heart from a single sweep 10 s acquisition. Methods: The authors introduce the 4D RecOnstructiOn using Spatial and TEmporal Regularization (short 4D ROOSTER) method, which reconstructs all cardiac phases at once, as a 3D + time volume. The algorithm alternates between a reconstruction step based on conjugate gradient and four regularization steps: enforcing positivity, averaging along time outside a motion mask that contains the heart and vessels, 3D spatial total variation minimization, and 1D temporal total variation minimization. Results: 4D ROOSTER recovers the different temporal representations of a moving Shepp and Logan phantom, and outperforms both ECG-gated simultaneous algebraic reconstruction technique and prior image constrained compressed sensing on a clinical case. It generates 3D + time reconstructions with sharp edges which can be used, for example, to estimate the patient's left ventricular ejection fraction. Conclusions: 4D ROOSTER can be applied for human cardiac C-arm CT, and potentially in other dynamic tomography areas. It can easily be adapted to other problems as regularization is decoupled from projection and back projection.

  11. MExLab Planetary Geoportal: 3D-access to planetary images and results of spatial data analysis

    NASA Astrophysics Data System (ADS)

    Karachevtseva, I.; Garov, A.

    2015-10-01

    MExLab Planetary Geoportal was developed as Geodesy and Cartography Node which provide access to results of study of celestial bodies such as DEM and orthoimages, as well as basemaps, crater catalogues and derivative products: slope, roughness, crater density (http://cartsrv.mexlab.ru/geoportal). The main feature of designed Geoportal is the ability of spatial queries and access to the contents selecting from the list of available data set (Phobos, Mercury, Moon, including Lunokhod's archive data). Prior version of Geoportal has been developed using Flash technology. Now we are developing new version which will use 3D-API (OpenGL, WebGL) based on shaders not only for standard 3D-functionality, but for 2D-mapping as well. Users can obtain quantitative and qualitative characteristics of the objects in graphical, tabular and 3D-forms. It will bring the advantages of unification of code and speed of processing and provide a number of functional advantages based on GIS-tools such as: - possibility of dynamic raster transform for needed map projection; - effective implementation of the co-registration of planetary images by combining spatial data geometries; - presentation in 3D-form different types of data, including planetary atmospheric measurements, subsurface radar data, ect. The system will be created with a new software architecture, which has a potential for development and flexibility in reconfiguration based on cross platform solution: - an application for the three types of platforms: desktop (Windows, Linux, OSX), web platform (any HTML5 browser), and mobile application (Android, iOS); - a single codebase shared between platforms (using cross compilation for Web); - a new telecommunication solution to connect between modules and external system like PROVIDE WebGIS (http://www.provide-space.eu/progis/). The research leading to these result was partly supported by the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement n

  12. Improving 8th Grades Spatial Thinking Abilities through a 3D Modeling Program

    ERIC Educational Resources Information Center

    Toptas, Veli; Celik, Serkan; Karaca, E. Tugce

    2012-01-01

    Implementation of emerging technology in sub disciplines of mathematics education provides a potential for educators to elaborate the capacity of digitized learning for human being. Spatial thinking is considered as a factor of scientific deduction from a multi disciplinary point of view. This paper reports a study aimed at exploring the effect of…

  13. Inferring Cross Sections of 3D Objects: A New Spatial Thinking Test

    ERIC Educational Resources Information Center

    Cohen, Cheryl A.; Hegarty, Mary

    2012-01-01

    A new spatial ability test was administered online to 223 undergraduate students enrolled in introductory science courses. The 30-item multiple choice test measures individual differences in ability to identify the two-dimensional cross section of a three-dimensional geometric solid, a skill that has been identified as important in science,…

  14. 3D replicon distributions arise from stochastic initiation and domino-like DNA replication progression

    PubMed Central

    Löb, D.; Lengert, N.; Chagin, V. O.; Reinhart, M.; Casas-Delucchi, C. S.; Cardoso, M. C.; Drossel, B.

    2016-01-01

    DNA replication dynamics in cells from higher eukaryotes follows very complex but highly efficient mechanisms. However, the principles behind initiation of potential replication origins and emergence of typical patterns of nuclear replication sites remain unclear. Here, we propose a comprehensive model of DNA replication in human cells that is based on stochastic, proximity-induced replication initiation. Critical model features are: spontaneous stochastic firing of individual origins in euchromatin and facultative heterochromatin, inhibition of firing at distances below the size of chromatin loops and a domino-like effect by which replication forks induce firing of nearby origins. The model reproduces the empirical temporal and chromatin-related properties of DNA replication in human cells. We advance the one-dimensional DNA replication model to a spatial model by taking into account chromatin folding in the nucleus, and we are able to reproduce the spatial and temporal characteristics of the replication foci distribution throughout S-phase. PMID:27052359

  15. 3D replicon distributions arise from stochastic initiation and domino-like DNA replication progression.

    PubMed

    Löb, D; Lengert, N; Chagin, V O; Reinhart, M; Casas-Delucchi, C S; Cardoso, M C; Drossel, B

    2016-04-07

    DNA replication dynamics in cells from higher eukaryotes follows very complex but highly efficient mechanisms. However, the principles behind initiation of potential replication origins and emergence of typical patterns of nuclear replication sites remain unclear. Here, we propose a comprehensive model of DNA replication in human cells that is based on stochastic, proximity-induced replication initiation. Critical model features are: spontaneous stochastic firing of individual origins in euchromatin and facultative heterochromatin, inhibition of firing at distances below the size of chromatin loops and a domino-like effect by which replication forks induce firing of nearby origins. The model reproduces the empirical temporal and chromatin-related properties of DNA replication in human cells. We advance the one-dimensional DNA replication model to a spatial model by taking into account chromatin folding in the nucleus, and we are able to reproduce the spatial and temporal characteristics of the replication foci distribution throughout S-phase.

  16. 3D Rheological Modeling of NW Intraplate Europe, Deciphering Spatial Integrated strength patterns, Mechanical Strong Layering and EET

    NASA Astrophysics Data System (ADS)

    Beekman, F.; Hardebol, N.; Cloetingh, S.; Tesauro, M.

    2006-12-01

    Better understanding of 3D rheological heterogeneity of the European Lithosphere provide the key to tie the recorded intraplate deformation pattern to stress fields transmitted into plate interior from plate boundary forces. The first order strain patterns result from stresses transmitted through the European lithosphere that is marked by a patchwork of high strength variability from inherited structural and compositional heterogeneities and upper mantle thermal perturbations. As the lithospheric rheology depends primarily on its spatial structure, composition and thermal estate, the 3D strength model for the European lithosphere relies on a 3D compositional model that yields the compositional heterogeneities and an iteratively calculated thermal cube using Fouriers law for heat conduction. The accurate appraisal of spatial strength variability results from proper mapping and integration of the geophysical compositional and thermal input parameters. Therefore, much attention has been paid to a proper description of first order structural and tectonic features that facilitate compilation of the compositional and thermal input models. As such, the 3D strength model reflects the thermo-mechanical structure inherited from the Europeans polyphase deformation history. Major 3D spatial mechanical strength variability has been revealed. The East-European and Fennoscandian Craton to the NE exhibit high strength (30-50 1012 N/m) from low mantle temperatures and surface heatflow of 35-60 mW/m2 while central and western Europe reflect a polyphase Phanerozoic thermo- tectonic history. Here, regions with high rigidity are formed primarily by patches of thermally stabilized Variscan Massifs (e.g. Rhenish, Armorican, Bohemian, and Iberian Massif) with low heatflow and lithospheric thickness values (50-65 mW/m2; 110-150 km) yielding strengths of ~15-25 1012 N/m. In contrast, major axis of weakened lithosphere coincides with Cenozoic Rift System (e.g. Upper and Lower Rhine Grabens

  17. Tracking and quantifying polymer therapeutic distribution on a cellular level using 3D dSTORM

    PubMed Central

    Hartley, Jonathan M.; Zhang, Rui; Gudheti, Manasa; Yang, Jiyuan; Kopeček, Jindřich

    2016-01-01

    We used a single-molecule localization technique called direct stochastic optical reconstruction microscopy (dSTORM) to quantify both colocalization and spatial distribution on a cellular level for two conceptually different N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer conjugates. Microscopy images were acquired of entire cells with resolutions as high as 25 nm revealing the nanoscale distribution of the fluorescently labeled therapeutic components. Drug-free macromolecular therapeutics consisting of two self-assembling nanoconjugates showed slight increase in nanoclusters on the cell surface with time. Additionally, dSTORM provided high resolution images of the nanoscale organization of the self-assembling conjugates at the interface between two cells. A conjugate designed for treating ovarian cancer showed that the model drug (Cy3) and polymer bound to Cy5 were colocalized at an early time point before the model drug was enzymatically cleaved from the polymer. Using spatial descriptive statistics it was found that the drug was randomly distributed after 24 h while the polymer bound dye remained in clusters. Four different fluorescent dyes were used and two different therapeutic systems were tested to demonstrate the versatility and possible general applicability of dSTORM for use in studying drug delivery systems. PMID:26855050

  18. The effects of age and workload on 3D spatial attention in dual-task driving

    PubMed Central

    Pierce, Russell S.; Andersen, George J.

    2014-01-01

    In the present study we assessed whether the limits in visual-spatial attention associated with aging affect the spatial extent of attention in depth during driving performance. Drivers in the present study performed a car-following and light-detection task. To assess the extent of visual-spatial attention, we compared reaction times and accuracy to light change targets that varied in horizontal position and depth location. In addition, because workload has been identified as a factor that can change the horizontal and vertical extent of attention, we tested whether variability of the lead car speed influenced the extent of spatial attention for younger or older drivers. For younger drivers, reaction time (RT) to light-change targets varied as a function of distance and horizontal position. For older drivers RT varied only as a function of distance. There was a distance by horizontal position interaction for younger drivers but not for older drivers. Specifically, there was no effect of horizontal position at any given level of depth for older drivers. However, for younger drivers there was an effect of horizontal position for targets further in depth but not for targets nearer in depth. With regards to workload, we found no statistically reliable evidence that variability of the lead car speed had an effect on the spatial extent of attention for younger or older drivers. In a control experiment, we examined the effects of depth on light detection when the projected size and position of the targets was constant. Consistent with our previous results, we found that drivers’ reaction time to light-change targets varied as a function of distance even when 2D position and size were controlled. Given that depth is an important dimension in driving performance, an important issue for assessing driving safety is to consider the limits of attention in the depth dimension. Therefore, we suggest that future research should consider the importance of depth as a dimension of

  19. A 3D engineered tumour for spatial snap-shot analysis of cell metabolism and phenotype in hypoxic gradients

    PubMed Central

    Rodenhizer, Darren; Gaude, Edoardo; Cojocari, Dan; Mahadevan, Radhakrishnan; Frezza, Christian; Wouters, Bradly G.; McGuigan, Alison P.

    2016-01-01

    The profound metabolic reprogramming that occurs in cancer cells has been investigated primarily in two-dimensional cell cultures, which fail to recapitulate spatial aspects of cell-to-cell interactions as well as tissue gradients present in three-dimensional (3D) tumours. Here, we describe an engineered model to assemble 3D tumours by rolling a scaffold-tumour composite strip. By unrolling the strip, the model can be rapidly disassembled for snap-shot analysis, allowing spatial mapping of cell metabolism in concert with cell phenotype. We also show that the establishment of oxygen gradients within samples are shaped by oxygen-dependent signalling pathways, as well as the consequential variations in cell growth, response to hypoxic gradients extending from normoxia to severe hypoxia, and therapy responsiveness, are consistent with tumours in vivo. Moreover, by using liquid chromatography tandem mass spectrometry, we mapped cellular metabolism and identified spatially defined metabolic signatures of cancer cells to reveal both known and novel metabolic responses to hypoxia. PMID:26595121

  20. 3D face recognition system using cylindrical hidden-layer neural network: spatial domain and its eigenspace domain

    NASA Astrophysics Data System (ADS)

    Kusumoputro, Benyamin; Pangabean, Martha Y.; Rachman, Leila F.

    2001-09-01

    In this paper, a 3-D face recognition system is developed using a modified neural network. This modified neural network is constructed by substituting each of neuron in its hidden layer of conventional multilayer perceptron with a circular-structure of neurons. This neural system is then called as cylindrical-structure of hidden layer neural network (CHL-NN). The neural system is then applied on a real 3-D face image database that consists of 5 Indonesian persons. The images are taken under four different expressions such as neutral, smile, laugh and free expression. The 2-D images is taken from the human face images by gradually changing visual points, which is done by successively varies the camera position from - 90 to +90 with an interval of 15 degree. The experimental result has shown that the average recognition rate of 60% could be achieved when we used the image in its spatial domain. Improvement of the system is then developed, by transforming the image in its spatial domain into its eigenspace domain. Karhunen Loeve transformation technique is used, and each image in the spatial domain is represented as a point in the eigenspace domain. Fisherface method is then utilized as a feature extraction on the eigenspace domain, and using the same database and experimental procedure, the recognition rate of the system could be increased into 84% in average.

  1. CCTV Coverage Index Based on Surveillance Resolution and Its Evaluation Using 3D Spatial Analysis

    PubMed Central

    Choi, Kyoungah; Lee, Impyeong

    2015-01-01

    We propose a novel approach to evaluating how effectively a closed circuit television (CCTV) system can monitor a targeted area. With 3D models of the target area and the camera parameters of the CCTV system, the approach produces surveillance coverage index, which is newly defined in this study as a quantitative measure for surveillance performance. This index indicates the proportion of the space being monitored with a sufficient resolution to the entire space of the target area. It is determined by computing surveillance resolution at every position and orientation, which indicates how closely a specific object can be monitored with a CCTV system. We present full mathematical derivation for the resolution, which depends on the location and orientation of the object as well as the geometric model of a camera. With the proposed approach, we quantitatively evaluated the surveillance coverage of a CCTV system in an underground parking area. Our evaluation process provided various quantitative-analysis results, compelling us to examine the design of the CCTV system prior to its installation and understand the surveillance capability of an existing CCTV system. PMID:26389909

  2. CCTV Coverage Index Based on Surveillance Resolution and Its Evaluation Using 3D Spatial Analysis.

    PubMed

    Choi, Kyoungah; Lee, Impyeong

    2015-09-16

    We propose a novel approach to evaluating how effectively a closed circuit television (CCTV) system can monitor a targeted area. With 3D models of the target area and the camera parameters of the CCTV system, the approach produces surveillance coverage index, which is newly defined in this study as a quantitative measure for surveillance performance. This index indicates the proportion of the space being monitored with a sufficient resolution to the entire space of the target area. It is determined by computing surveillance resolution at every position and orientation, which indicates how closely a specific object can be monitored with a CCTV system. We present full mathematical derivation for the resolution, which depends on the location and orientation of the object as well as the geometric model of a camera. With the proposed approach, we quantitatively evaluated the surveillance coverage of a CCTV system in an underground parking area. Our evaluation process provided various quantitative-analysis results, compelling us to examine the design of the CCTV system prior to its installation and understand the surveillance capability of an existing CCTV system.

  3. Simulation on an optimal combustion control strategy for 3-D temperature distributions in tangentially pc-fired utility boiler furnaces.

    PubMed

    Wang, Xi-fen; Zhou, Huai-chun

    2005-01-01

    The control of 3-D temperature distribution in a utility boiler furnace is essential for the safe, economic and clean operation of pc-fired furnace with multi-burner system. The development of the visualization of 3-D temperature distributions in pc-fired furnaces makes it possible for a new combustion control strategy directly with the furnace temperature as its goal to improve the control quality for the combustion processes. Studied in this paper is such a new strategy that the whole furnace is divided into several parts in the vertical direction, and the average temperature and its bias from the center in every cross section can be extracted from the visualization results of the 3-D temperature distributions. In the simulation stage, a computational fluid dynamics (CFD) code served to calculate the 3-D temperature distributions in a furnace, then a linear model was set up to relate the features of the temperature distributions with the input of the combustion processes, such as the flow rates of fuel and air fed into the furnaces through all the burners. The adaptive genetic algorithm was adopted to find the optimal combination of the whole input parameters which ensure to form an optimal 3-D temperature field in the furnace desired for the operation of boiler. Simulation results showed that the strategy could soon find the factors making the temperature distribution apart from the optimal state and give correct adjusting suggestions.

  4. 3D Ion and Electron Distribution Function Measurements from the Fast Plasma Investigation on the Magnetospheric Multiscale Mission

    NASA Astrophysics Data System (ADS)

    Giles, B. L.; Pollock, C. J.; Avanov, L. A.; Barrie, A. C.; Burch, J. L.; Chandler, M. O.; Clark, G. B.; Coffey, V. N.; Dickson, C.; Dorelli, J.; Ergun, R. E.; Fuselier, S. A.; Gershman, D. J.; Gliese, U.; Holland, M. P.; Jacques, A. D.; Kreisler, S.; Lavraud, B.; MacDonald, E.; Mauk, B.; Moore, T. E.; Mukai, T.; Nakamura, R.; Paterson, W. R.; Rager, A. C.; Saito, Y.; Salo, C.; Sauvaud, J. A.; Torbert, R. B.; Vinas, A. F.; Yokota, S.

    2015-12-01

    The primary focus of the Magnetospheric Multiscale (MMS) mission, launched in March 2015, is magnetic reconnection and associated processes. Understanding hinges critically on the kinetic physics that allows reconnection to take place. The Fast Plasma Investigation (FPI) provides electron and ion distribution functions at 4.5s cadence and, for select periods of time, at cadences of 30ms for electrons and 150ms for ions. These select time periods are chosen after in situ acquisition based on inspection of the low resolution data. Thus the FPI provides, independent of spacecraft spin rate, the time resolution needed to resolve the small, fast-moving reconnection diffusion regions. The first mission phase focuses on the dayside magnetopause and this presentation is intended to demonstrate the capabilities of FPI to resolve the important spatial scales relevant to the reconnection process. Magnetopause and other boundary crossings will be examined and the phase-space trajectories identified at the tetrahedral satellite locations through analysis of the 3D distribution functions.

  5. Nanoscale 3D distribution of low melt and fluid fractions in mantle rocks

    NASA Astrophysics Data System (ADS)

    Gardes, Emmanuel; Morales, Luiz; Heinrich, Wilhelm; Sifre, David; Hashim, Leila; Gaillard, Fabrice; Katharina, Marquardt

    2016-04-01

    The presence of melts or fluids in the intergranular medium of rocks strongly influences their bulk physico-chemical properties (e.g. mass transport and chemical reactivity, electrical conductivity, seismic wave velocity, etc). Actually, the effects can be so large that only small melt or fluid fractions must sometimes be involved for explaining mantle geophysical discontinuities and anomalies. The investigation of the distribution of such small fractions in the intergranular medium of mantle rocks is therefore crucial for relating them to bulk and large scale properties. However, it involves submicrometric structures which are hardly characterizable using conventional techniques. Here we present how the FIB-SEM-STEM microscope can be used to produce 3D imaging at unequalled resolution. We show that low melt and fluid fractions can form films as thin as 20 nm at olivine grain boundaries, and that they can modify the physico-chemical properties of mantle rocks by orders of magnitude. The fine relationships between films at grain boundaries, tubules at triple junctions and pockets at grain corners can be explored, and appear to be complex and to differ from usual visions.

  6. Calibration of an outdoor distributed camera network with a 3D point cloud.

    PubMed

    Ortega, Agustín; Silva, Manuel; Teniente, Ernesto H; Ferreira, Ricardo; Bernardino, Alexandre; Gaspar, José; Andrade-Cetto, Juan

    2014-07-29

    Outdoor camera networks are becoming ubiquitous in critical urban areas of the largest cities around the world. Although current applications of camera networks are mostly tailored to video surveillance, recent research projects are exploiting their use to aid robotic systems in people-assisting tasks. Such systems require precise calibration of the internal and external parameters of the distributed camera network. Despite the fact that camera calibration has been an extensively studied topic, the development of practical methods for user-assisted calibration that minimize user intervention time and maximize precision still pose significant challenges. These camera systems have non-overlapping fields of view, are subject to environmental stress, and are likely to suffer frequent recalibration. In this paper, we propose the use of a 3D map covering the area to support the calibration process and develop an automated method that allows quick and precise calibration of a large camera network. We present two cases of study of the proposed calibration method: one is the calibration of the Barcelona Robot Lab camera network, which also includes direct mappings (homographies) between image coordinates and world points in the ground plane (walking areas) to support person and robot detection and localization algorithms. The second case consist of improving the GPS positioning of geo-tagged images taken with a mobile device in the Facultat de Matemàtiques i Estadística (FME) patio at the Universitat Politècnica de Catalunya (UPC).

  7. Stress distribution on external hexagon implant system using 3d finite element analysis.

    PubMed

    Segundo, Regênio M H; Oshima, Hugo M S; Silva, Isaac N L; Júnior, Luis H B; Mota, Eduardo G; Coelho, Luiz F B

    2007-01-01

    The aim of this study was to compare and evaluate strain distribution on dental implant, abutment, screw and crown virtual models in the posterior region. The analysis was performed by means of a 3D virtual model developed by the PRO-ENGINEER System (PRO-ENGINEER, PTC, Needham, MA, USA ) with an external butt joint (3i Implant Innovations, Palm Beach, Florida), square headed Gold Tite abutment retainer screw (3i Implant Innovations, Palm Beach, Florida), STA abutment (3i Implant Innovations, Palm Beach, Florida), metal infrastructure of Ag-Pd alloy and feldspatic ceramic. The standard load was 382N at 15 degree angle to the implant axis, applied at 6 mm from the implant center at different observation points on the implant-screw set. The data showed that on the implant virtual model, the highest strain concentration was found at the interface between the implant platform and the abutment, and in the middle point of the 1st screw thread internal diameter on the load application side.

  8. Calibration of an Outdoor Distributed Camera Network with a 3D Point Cloud

    PubMed Central

    Ortega, Agustín; Silva, Manuel; Teniente, Ernesto H.; Ferreira, Ricardo; Bernardino, Alexandre; Gaspar, José; Andrade-Cetto, Juan

    2014-01-01

    Outdoor camera networks are becoming ubiquitous in critical urban areas of the largest cities around the world. Although current applications of camera networks are mostly tailored to video surveillance, recent research projects are exploiting their use to aid robotic systems in people-assisting tasks. Such systems require precise calibration of the internal and external parameters of the distributed camera network. Despite the fact that camera calibration has been an extensively studied topic, the development of practical methods for user-assisted calibration that minimize user intervention time and maximize precision still pose significant challenges. These camera systems have non-overlapping fields of view, are subject to environmental stress, and are likely to suffer frequent recalibration. In this paper, we propose the use of a 3D map covering the area to support the calibration process and develop an automated method that allows quick and precise calibration of a large camera network. We present two cases of study of the proposed calibration method: one is the calibration of the Barcelona Robot Lab camera network, which also includes direct mappings (homographies) between image coordinates and world points in the ground plane (walking areas) to support person and robot detection and localization algorithms. The second case consist of improving the GPS positioning of geo-tagged images taken with a mobile device in the Facultat de Matemàtiques i Estadística (FME) patio at the Universitat Politècnica de Catalunya (UPC). PMID:25076221

  9. 3D-Simulation Of Concentration Distributions Inside Large-Scale Circulating Fluidized Bed Combustors

    NASA Astrophysics Data System (ADS)

    Wischnewski, R.; Ratschow, L.; Hartge, E. U.; Werthe, J.

    With increasing size of modern CFB combustors the lateral mixing of fuels and secondary air gains more and more importance. Strong concentration gradients, which result from improper lateral mixing, can lead to operational problems, high flue gas emissions and lower boiler efficiencies. A 3D-model for the simulation of local gas and solids concentrations inside industrial-sized CFB boilers has been developed. The model is based on a macroscopic approach and considers all major mechanisms during fuel spreading and subsequent combustion of char and volatiles. Typical characteristics of modern boilers like staged combustion, a smaller cross-sectional area in the lower section of the combustion chamber and the co-combustion of additional fuels with coal can be considered. The 252 MWth combustor of Stadtwerke Duisburg AG is used for the validation of the model. A comprehensive picture of the local conditions inside the combustion chamber is achieved by the combination of local gas measurements and the three-dimensional simulation of concentration distributions.

  10. MR Elastography Studies of the 3D Force Chain Structure in Dense Granular Media: Distribution of Chain Lengths

    NASA Astrophysics Data System (ADS)

    Sanfratello, L.; Fukushima, E.

    2009-06-01

    We recently developed a novel extension of MR Elastograpy (MRE) to image the force chain structure within a dense 3D quasi-static granular assembly. Subsequently, computer codes and algorithms to determine the distribution of the force chain lengths, where a chain is taken to be a relatively straight section between branching points, were developed. Similar tools were used previously to analyze 2D photoelastic data and now have been expanded to analyze our most current 3D MRE force chain data. These investigations reveal that the distribution of the chain lengths in 3D decays exponentially, as was observed in 2D. The exponential decay of the length distribution is consistent with DEM simulation results of Peters, et al. We conclude that the decay length of this distribution is a meaningful quantitative measure that characterizes granular assemblies.

  11. Reconstructing the 3D fracture distribution model from core (10 cm) to outcrop (10 m) and lineament (10 km) scales

    NASA Astrophysics Data System (ADS)

    Darcel, C.; Davy, P.; Bour, O.; de Dreuzy, J.

    2006-12-01

    Considering the role of fractures in hydraulic flow, the knowledge of the 3D spatial distribution of fractures is a basic concern for any hydrogeology-related study (potential leakages in waste repository, aquifer management, ?). Unfortunately geophysical imagery is quite blind with regard to fractures, and only the largest ones are generally detected, if they are. Actually most of the information has to be derived from statistical models whose parameters are defined from a few sparse sampling areas, such as wells, outcrops, or lineament maps. How these observations obtained at different scales can be linked to each other is a critical point, which directly addresses the issue of fracture scaling. In this study, we use one of the most important datasets that have ever been collected for characterizing fracture networks. It was collected by the Swedish company SKB for their research program on deep repository for radioactive waste, and consists of large-scale lineament maps covering about 100 km2, several outcrops of several hundreds of m2 mapped with a fracture trace length resolution down to 0.50 m, and a series of 1000m-deep cored boreholes where both fracture orientations and fracture intensities were carefully recorded. Boreholes are an essential complement to surface outcrops as they allow the sampling of horizontal fracture planes that, generally, are severely undersampled in subhorizontal outcrops. Outcrops, on the other hand, provide information on fracture sizes which is not possible to address from core information alone. However linking outcrops and boreholes is not straightforward: the sampling scale is obviously different and some scaling rules have to be applied to relate both fracture distributions; outcrops are 2D planes while boreholes are mostly 1D records; outcrops can be affected by superficial fracturing processes that are not representative of the fracturing at depth. We present here the stereology methods for calculating the 3D distribution

  12. Visualizing Spatially Varying Distribution Data

    NASA Technical Reports Server (NTRS)

    Kao, David; Luo, Alison; Dungan, Jennifer L.; Pang, Alex; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    Box plot is a compact representation that encodes the minimum, maximum, mean, median, and quarters information of a distribution. In practice, a single box plot is drawn for each variable of interest. With the advent of more accessible computing power, we are now facing the problem of visual icing data where there is a distribution at each 2D spatial location. Simply extending the box plot technique to distributions over 2D domain is not straightforward. One challenge is reducing the visual clutter if a box plot is drawn over each grid location in the 2D domain. This paper presents and discusses two general approaches, using parametric statistics and shape descriptors, to present 2D distribution data sets. Both approaches provide additional insights compared to the traditional box plot technique

  13. High order spatial expansion for the method of characteristics applied to 3-D geometries

    SciTech Connect

    Naymeh, L.; Masiello, E.; Sanchez, R.

    2013-07-01

    The method of characteristics is an efficient and flexible technique to solve the neutron transport equation and has been extensively used in two-dimensional calculations because it permits to deal with complex geometries. However, because of a very fast increase in storage requirements and number of floating operations, its direct application to three-dimensional routine transport calculations it is not still possible. In this work we introduce and analyze several modifications aimed to reduce memory requirements and to diminish the computing burden. We explore high-order spatial approximation, the use of intermediary trajectory-dependent flux expansions and the possibility of dynamic trajectory reconstruction from local tracking for typed subdomains. (authors)

  14. Improved 2D/3D registration robustness using local spatial information

    NASA Astrophysics Data System (ADS)

    De Momi, Elena; Eckman, Kort; Jaramaz, Branislav; DiGioia, Anthony, III

    2006-03-01

    Xalign is a tool designed to measure implant orientation after joint arthroplasty by co-registering a projection of an implant model and a digitally reconstructed radiograph of the patient's anatomy with a post operative x-ray. A mutual information based registration method is used to automate alignment. When using basic mutual information, the presence of local maxima can result in misregistration. To increase robustness of registration, our research is aimed at improving the similarity function by modifying the information measure and incorporating local spatial information. A test dataset with known groundtruth parameters was created to evaluate the performance of this measure. A synthetic radiograph was generated first from a preoperative pelvic CT scan to act as the gold standard. The voxel weights used to generate the image were then modified and new images were generated with the CT rigidly transformed. The roll, pitch and yaw angles span a range of -10/+10 degrees, while x, y and z translations range from -10mm to +10mm. These images were compared with the reference image. The proposed cost function correctly identified the correct pose in all tests and did not exhibit any local maxima which would slow or prevent locating the global maximum.

  15. Spatial light modulator phase mask implementation of wavefront encoded 3D computational-optical microscopy.

    PubMed

    King, Sharon V; Doblas, Ana; Patwary, Nurmohammed; Saavedra, Genaro; Martínez-Corral, Manuel; Preza, Chrysanthe

    2015-10-10

    Spatial light modulator (SLM) implementation of wavefront encoding enables various types of engineered point-spread functions (PSFs), including the generalized-cubic and squared-cubic phase mask wavefront encoded (WFE) PSFs, shown to reduce the impact of sample-induced spherical aberration in fluorescence microscopy. This investigation validates dynamic experimental parameter variation of these WFE-PSFs. We find that particular design parameter bounds exist, within which the divergence of computed and experimental WFE-PSFs is of the same order of magnitude as that of computed and experimental conventional PSFs, such that model-based approaches for solving the inverse imaging problem can be applied to a wide range of SLM-WFE systems. Interferometric measurements were obtained to evaluate the SLM implementation of the numeric mask. Agreement between experiment and theory in terms of a wrapped phase, 0-2π, validates the phase mask implementation and allows characterization of the SLM response. These measurements substantiate experimental practice of computational-optical microscope imaging with an SLM-engineered PSF.

  16. The estimation of 3D SAR distributions in the human head from mobile phone compliance testing data for epidemiological studies.

    PubMed

    Wake, Kanako; Varsier, Nadège; Watanabe, Soichi; Taki, Masao; Wiart, Joe; Mann, Simon; Deltour, Isabelle; Cardis, Elisabeth

    2009-10-07

    A worldwide epidemiological study called 'INTERPHONE' has been conducted to estimate the hypothetical relationship between brain tumors and mobile phone use. In this study, we proposed a method to estimate 3D distribution of the specific absorption rate (SAR) in the human head due to mobile phone use to provide the exposure gradient for epidemiological studies. 3D SAR distributions due to exposure to an electromagnetic field from mobile phones are estimated from mobile phone compliance testing data for actual devices. The data for compliance testing are measured only on the surface in the region near the device and in a small 3D region around the maximum on the surface in a homogeneous phantom with a specific shape. The method includes an interpolation/extrapolation and a head shape conversion. With the interpolation/extrapolation, SAR distributions in the whole head are estimated from the limited measured data. 3D SAR distributions in the numerical head models, where the tumor location is identified in the epidemiological studies, are obtained from measured SAR data with the head shape conversion by projection. Validation of the proposed method was performed experimentally and numerically. It was confirmed that the proposed method provided good estimation of 3D SAR distribution in the head, especially in the brain, which is the tissue of major interest in epidemiological studies. We conclude that it is possible to estimate 3D SAR distributions in a realistic head model from the data obtained by compliance testing measurements to provide a measure for the exposure gradient in specific locations of the brain for the purpose of exposure assessment in epidemiological studies. The proposed method has been used in several studies in the INTERPHONE.

  17. Recording, Visualization and Documentation of 3D Spatial Data for Monitoring Topography in Areas of Cultural Heritage

    NASA Astrophysics Data System (ADS)

    Maravelakis, Emmanouel; Konstantaras, Antonios; Axaridou, Anastasia; Chrysakis, Ioannis; Xinogalos, Michalis

    2014-05-01

    . allowing them to interchange their knowledge, findings and observations at different time frames. Results outline the successful application of the above systems in certain Greek areas of important cultural heritage [3,11] were significant efforts are being made for their preservation through time. Acknowledgement The authors wish to thank the General Secretariat for Research and Technology of Ministry of Education and Religious Affairs, Culture and Sports in Greece for their financial support via program Cooperation: Partnership of Production and Research Institutions in Small and Medium Scale Projects, Project Title: "3D-SYSTEK - Development of a novel system for 3D Documentation, Promotion and Exploitation of Cultural Heritage Monuments via 3D data acquisition, 3D modeling and metadata recording". Keywords spatial data, land degradation monitoring, 3D modeling and visualization, terrestrial laser scanning, documentation and metadata repository, protection of cultural heritage References [1] Shalaby, A., and Tateishi, R.: Remote sensing and GIS for mapping and monitoring land cover and land-use changes in the northwestern coastal zone of egypt. Applied Geography, 27(1), 28-41, (2007) [2] Poesen, J. W. A., and Hooke, J. M.: Erosion, flooding and channel management in mediterranean environments of southern europe. Progress in Physical Geography, 21(2), 157-199, (1997) [3] Maravelakis, E., Bilalis, N., Mantzorou, I., Konstantaras, A., Antoniadis, A.: 3D modeling of the oldest olive tree of the world. IJCER 2(2), 340-347 (2012) [4] Manferdini, A.M., Remondino, F.: Reality-Based 3D Modeling, Segmentation and Web- Based Visualization. In: Ioannides, M., Fellner, D., Georgopoulos, A., Hadjimitsis, D.G. (eds.) EuroMed 2010. LNCS, vol. 6436, pp. 110-124. Springer, Heidelberg (2010) [5] Tapete, D., Casagli, N., Luzi, G., Fanti, R., Gigli, G., Leva, D.: Integrating radar and laserbased remote sensing techniques for monitoring structural deformation of archaeological monuments

  18. High-Performance Computation of Distributed-Memory Parallel 3D Voronoi and Delaunay Tessellation

    SciTech Connect

    Peterka, Tom; Morozov, Dmitriy; Phillips, Carolyn

    2014-11-14

    Computing a Voronoi or Delaunay tessellation from a set of points is a core part of the analysis of many simulated and measured datasets: N-body simulations, molecular dynamics codes, and LIDAR point clouds are just a few examples. Such computational geometry methods are common in data analysis and visualization; but as the scale of simulations and observations surpasses billions of particles, the existing serial and shared-memory algorithms no longer suffice. A distributed-memory scalable parallel algorithm is the only feasible approach. The primary contribution of this paper is a new parallel Delaunay and Voronoi tessellation algorithm that automatically determines which neighbor points need to be exchanged among the subdomains of a spatial decomposition. Other contributions include periodic and wall boundary conditions, comparison of our method using two popular serial libraries, and application to numerous science datasets.

  19. Localised vs distributed deformation: 3D modelling of the Dead Sea region

    NASA Astrophysics Data System (ADS)

    Devès, M. H.; King, G. C.; Klinger, Y.; Agnon, A.

    2012-12-01

    The lithosphere behaves as strain softening elasto-plastic materials. In the laboratory, such materials are known to deform in a brittle or a ductile manner depending on the applied geometric boundary conditions. In the lithosphere however, the importance of boundary conditions in controlling the deformation style has been largely ignored. Under general boundary conditions, both laboratory and field observations show that only part of the deformation can localise on through going faults while the rest must remain distributed in process zones where spatially varying shear directions inhibit localisation. Conventional modelling methods use rheologies deduced from laboratory experiments that are not constrained as a function of the geometry of the applied boundary conditions. We propose an alternative modelling method based on the use of an appropriate distribution of dislocation sources to create the deformation field. This approach, because it does not rely on integrating differential equations from more or less well-constrained boundary conditions, does not require making assumptions on the parameters controlling the level and distribution of stresses within the lithosphere. It only supposes that strain accumulates linearly away from the dislocation singularities satisfying the compatibility equations. We verify that this model explains important and hitherto unexplained features of the topography of the Dead Sea region. Following the idea that strain can only localise under specific conditions as inferred from laboratory and field scale observations, we use our model of deformation to predict where deformation can localise and where it has to remain distributed. We find that 65% of the deformation in the Dead Sea region can localise on kinematically stable through-going strike-slip faults while the remaining 35% must remain distributed. Observations suggest that distributed deformation occurs at stress levels that can be ten times greater than that associated with

  20. Spatial Distributions of Young Stars

    NASA Astrophysics Data System (ADS)

    Kraus, Adam L.; Hillenbrand, Lynne A.

    2008-10-01

    We analyze the spatial distribution of young stars in Taurus-Auriga and Upper Sco, as determined from the two-point correlation function (i.e., the mean surface density of neighbors). The corresponding power-law fits allow us to determine the fractal dimensions of each association's spatial distribution, measure the stellar velocity dispersions, and distinguish between the bound binary population and chance alignments of members. We find that the fractal dimension of Taurus is D ~ 1.05, consistent with its filamentary structure. The fractal dimension of Upper Sco may be even shallower (D ~ 0.7), but this fit is uncertain due to the limited area and possible spatially variable incompleteness. We also find that random stellar motions have erased all primordial structure on scales of lsim0.07° in Taurus and lsim1.7° in Upper Sco; given ages of ~1 and ~5 Myr, the corresponding internal velocity dispersions are ~0.2 and ~1.0 km s-1, respectively. Finally, we find that binaries can be distinguished from chance alignments at separations of lsim120'' (17,000 AU) in Taurus and lsim75'' (11,000 AU) in Upper Sco. The binary populations in these associations that we previously studied, spanning separations of 3''-30'', is dominated by binary systems. However, the few lowest mass pairs (Mprim <~ 0.3 M⊙) might be chance alignments.

  1. Reconstruction of the ionospheric 3D electron density distribution by assimilation of ionosonde measurements and operational TEC estimations

    NASA Astrophysics Data System (ADS)

    Gerzen, Tatjana; Wilken, Volker; Jakowski, Norbert; Hoque, Mainul M.

    2013-04-01

    tandem with a new approach of a DLR internal empirical 3D electron density model is used to reconstruct the actual spatial electron density distribution of the ionosphere.

  2. GRID2D/3D: A computer program for generating grid systems in complex-shaped two- and three-dimensional spatial domains. Part 2: User's manual and program listing

    NASA Technical Reports Server (NTRS)

    Bailey, R. T.; Shih, T. I.-P.; Nguyen, H. L.; Roelke, R. J.

    1990-01-01

    An efficient computer program, called GRID2D/3D, was developed to generate single and composite grid systems within geometrically complex two- and three-dimensional (2- and 3-D) spatial domains that can deform with time. GRID2D/3D generates single grid systems by using algebraic grid generation methods based on transfinite interpolation in which the distribution of grid points within the spatial domain is controlled by stretching functions. All single grid systems generated by GRID2D/3D can have grid lines that are continuous and differentiable everywhere up to the second-order. Also, grid lines can intersect boundaries of the spatial domain orthogonally. GRID2D/3D generates composite grid systems by patching together two or more single grid systems. The patching can be discontinuous or continuous. For continuous composite grid systems, the grid lines are continuous and differentiable everywhere up to the second-order except at interfaces where different single grid systems meet. At interfaces where different single grid systems meet, the grid lines are only differentiable up to the first-order. For 2-D spatial domains, the boundary curves are described by using either cubic or tension spline interpolation. For 3-D spatial domains, the boundary surfaces are described by using either linear Coon's interpolation, bi-hyperbolic spline interpolation, or a new technique referred to as 3-D bi-directional Hermite interpolation. Since grid systems generated by algebraic methods can have grid lines that overlap one another, GRID2D/3D contains a graphics package for evaluating the grid systems generated. With the graphics package, the user can generate grid systems in an interactive manner with the grid generation part of GRID2D/3D. GRID2D/3D is written in FORTRAN 77 and can be run on any IBM PC, XT, or AT compatible computer. In order to use GRID2D/3D on workstations or mainframe computers, some minor modifications must be made in the graphics part of the program; no

  3. Deformable segmentation of 3D MR prostate images via distributed discriminative dictionary and ensemble learning

    SciTech Connect

    Guo, Yanrong; Shao, Yeqin; Gao, Yaozong; Price, True; Oto, Aytekin; Shen, Dinggang

    2014-07-15

    patches of the prostate surface and trained to adaptively capture the appearance in different prostate zones, thus achieving better local tissue differentiation. For each local region, multiple classifiers are trained based on the randomly selected samples and finally assembled by a specific fusion method. In addition to this nonparametric appearance model, a prostate shape model is learned from the shape statistics using a novel approach, sparse shape composition, which can model nonGaussian distributions of shape variation and regularize the 3D mesh deformation by constraining it within the observed shape subspace. Results: The proposed method has been evaluated on two datasets consisting of T2-weighted MR prostate images. For the first (internal) dataset, the classification effectiveness of the authors' improved dictionary learning has been validated by comparing it with three other variants of traditional dictionary learning methods. The experimental results show that the authors' method yields a Dice Ratio of 89.1% compared to the manual segmentation, which is more accurate than the three state-of-the-art MR prostate segmentation methods under comparison. For the second dataset, the MICCAI 2012 challenge dataset, the authors' proposed method yields a Dice Ratio of 87.4%, which also achieves better segmentation accuracy than other methods under comparison. Conclusions: A new magnetic resonance image prostate segmentation method is proposed based on the combination of deformable model and dictionary learning methods, which achieves more accurate segmentation performance on prostate T2 MR images.

  4. Strength and Performance Enhancement of Bonded Joints by Spatial Tailoring of Adhesive Compliance via 3D Printing.

    PubMed

    Kumar, S; Wardle, Brian L; Arif, Muhamad F

    2017-01-11

    Adhesive bonding continues to emerge as a preferred route for joining materials with broad applications including advanced structures, microelectronics, biomedical systems, and consumer goods. Here, we study the mechanics of deformation and failure of tensile-loaded single-lap joints with a compliance-tailored adhesive. Tailoring of the adhesive compliance redistributes stresses and strains to reduce both shear and peel concentrations at the ends of the adhesive that determine failure of the joint. Utilizing 3D printing, the modulus of the adhesive is spatially varied along the bondlength. Experimental strength testing, including optical strain mapping, reveals that the strain redistribution results in a greater than 100% increase in strength and toughness concomitant with a 50% increase in strain-to-break while maintaining joint stiffness. The tailoring demonstrated here is immediately realizable in a broad array of 3D printing applications, and the level of performance enhancement suggests that compliance tailoring of the adhesive is a generalizable route for achieving superior performance of joints in other applications, such as advanced structural composites.

  5. 3D Quantitative Confocal Laser Microscopy of Ilmenite Volume Distribution in Alpe Arami Olivine

    NASA Astrophysics Data System (ADS)

    Bozhilov, K. N.

    2001-12-01

    The deep origin of the Alpe Arami garnet lherzolite massif in the Swiss Alps proposed by Dobrzhinetskaya et al. (Science, 1996) has been a focus of heated debate. One of the lines of evidence supporting an exhumation from more than 200 km depth includes the abundance, distribution, and orientation of magnesian ilmenite rods in the oldest generation of olivine. This argument has been disputed in terms of the abundance of ilmenite and consequently the maximum TiO2 content in the discussed olivine. In order to address this issue, we have directly measured the volume fraction of ilmenite of the oldest generation of olivine by applying confocal laser scanning microscopy (CLSM). CLSM is a method which allows for three-dimensional imaging and quantitative volume determination by optical sectioning of the objects. The images for 3D reconstruction and measurements were acquired from petrographic thin sections in reflected laser light with 488 nm wavelength. Measurements of more than 80 olivine grains in six thin sections of our material yielded an average volume fraction of 0.31% ilmenite in the oldest generation of olivine from Alpe Arami. This translates into 0.23 wt.% TiO2 in olivine with error in determination of ±0.097 wt.%, a value significantly different from that of 0.02 to 0.03 wt.% TiO2 determined by Hacker et al. (Science, 1997) by a broad-beam microanalysis technique. During the complex geological history of the Alpe Arami massif, several events of metamorphism are recorded which all could have caused increased mobility of the mineral components. Evidence for loss of TiO2 from olivine is the tendency for high densities of ilmenite to be restricted to cores of old grains, the complete absence of ilmenite inclusions from the younger, recrystallized, generation of olivine, and reduction in ilmenite size and abundance in more serpentinized specimens. These observations suggest that only olivine grains with the highest concentrations of ilmenite are close to the

  6. Properties of the prominence magnetic field and plasma distributions as obtained from 3D whole-prominence fine structure modeling

    NASA Astrophysics Data System (ADS)

    Gunár, S.; Mackay, D. H.

    2016-07-01

    Aims: We analyze distributions of the magnetic field strength and prominence plasma (temperature, pressure, plasma β, and mass) using the 3D whole-prominence fine structure model. Methods: The model combines a 3D magnetic field configuration of an entire prominence, obtained from non-linear force-free field simulations, with a detailed semi-empirically derived 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. Results: We show that in the modeled prominence, the variations of the magnetic field strength and its orientation are insignificant on scales comparable to the smallest dimensions of the observed prominence fine structures. We also show the ability of the 3D whole-prominence fine structure model to reveal the distribution of the prominence plasma with respect to its temperature within the prominence volume. This provides new insights into the composition of the prominence-corona transition region. We further demonstrate that the values of the plasma β are small throughout the majority of the modeled prominences when realistic photospheric magnetic flux distributions and prominence plasma parameters are assumed. While this is generally true, we also find that in the region with the deepest magnetic dips, the plasma β may increase towards unity. Finally, we show that the mass of the modeled prominence plasma is in good agreement with the mass of observed non-eruptive prominences.

  7. Supporting Distributed Team Working in 3D Virtual Worlds: A Case Study in Second Life

    ERIC Educational Resources Information Center

    Minocha, Shailey; Morse, David R.

    2010-01-01

    Purpose: The purpose of this paper is to report on a study into how a three-dimensional (3D) virtual world (Second Life) can facilitate socialisation and team working among students working on a team project at a distance. This models the situation in many commercial sectors where work is increasingly being conducted across time zones and between…

  8. A Portable 3D FFT Package for Distributed-Memory Parallel Architectures

    NASA Technical Reports Server (NTRS)

    Ding, H. Q.; Ferraro, R. D.; Gennery, D. B.

    1995-01-01

    A parallel algorithm for 3D FFTs is implemented as a series of local 1D FFTs combined with data transposes. This allows the use of vendor supplied (often fully optimized) sequential 1D FFTs. The FFTs are carried out in-place by using an in-place data transpose across the processors.

  9. Mapping molecular orientational distributions for biological sample in 3D (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    HE, Wei; Ferrand, Patrick; Richter, Benjamin; Bastmeyer, Martin; Brasselet, Sophie

    2016-04-01

    Measuring molecular orientation properties is very appealing for scientists in molecular and cell biology, as well as biomedical research. Orientational organization at the molecular scale is indeed an important brick to cells and tissues morphology, mechanics, functions and pathologies. Recent work has shown that polarized fluorescence imaging, based on excitation polarization tuning in the sample plane, is able to probe molecular orientational order in biological samples; however this applies only to information in 2D, projected in the sample plane. To surpass this limitation, we extended this approach to excitation polarization tuning in 3D. The principle is based on the decomposition of any arbitrary 3D linear excitation in a polarization along the longitudinal z-axis, and a polarization in the transverse xy-sample plane. We designed an interferometer with one arm generating radial polarization light (thus producing longitudinal polarization under high numerical aperture focusing), the other arm controlling a linear polarization in the transverse plane. The amplitude ratio between the two arms can vary so as to get any linear polarized excitation in 3D at the focus of a high NA objective. This technique has been characterized by polarimetry imaging at the back focal plane of the focusing objective, and modeled theoretically. 3D polarized fluorescence microscopy is demonstrated on actin stress fibers in non-flat cells suspended on synthetic polymer structures forming supporting pillars, for which heterogeneous actin orientational order could be identified. This technique shows a great potential in structural investigations in 3D biological systems, such as cell spheroids and tissues.

  10. 3D analysis of synaptic vesicle density and distribution after acute foot-shock stress by using serial section transmission electron microscopy.

    PubMed

    Khanmohammadi, M; Darkner, S; Nava, N; Nyengaard, J R; Wegener, G; Popoli, M; Sporring, J

    2017-01-01

    Behavioural stress has shown to strongly affect neurotransmission within the neocortex. In this study, we analysed the effect of an acute stress model on density and distribution of neurotransmitter-containing vesicles within medial prefrontal cortex. Serial section transmission electron microscopy was employed to compare two groups of male rats: (1) rats subjected to foot-shock stress and (2) rats with sham stress as control group. Two-dimensional (2D) density measures are common in microscopic images and are estimated by following a 2D path in-section. However, this method ignores the slant of the active zone and thickness of the section. In fact, the active zone is a surface in three-dimension (3D) and the 2D measures do not accurately reflect the geometric configuration unless the active zone is perpendicular to the sectioning angle. We investigated synaptic vesicle density as a function of distance from the active zone in 3D. We reconstructed a 3D dataset by estimating the thickness of all sections and by registering all the image sections into a common coordinate system. Finally, we estimated the density as the average number of vesicles per area and volume and modelled the synaptic vesicle distribution by fitting a one-dimensional parametrized distribution that took into account the location uncertainty due to section thickness. Our results showed a clear structural difference in synaptic vesicle density and distribution between stressed and control group with improved separation by 3D measures in comparison to the 2D measures. Our results showed that acute foot-shock stress exposure significantly affected both the spatial distribution and density of the synaptic vesicles within the presynaptic terminal.

  11. Confocal (micro)-XRF for 3D anlaysis of elements distribution in hot environmental particles

    SciTech Connect

    Bielewski, M; Eriksson, M; Himbert, J; Simon, R; Betti, M; Hamilton, T F

    2007-11-27

    calculations. In figure 1 the distributions of Pu, Fe and Ti obtained for one of the studied hot particles are presented. The strongest signal was recorded for plutonium; the signals from iron and titanium are respectively 14 and 38 times less. It means that Pu is the most abundant of the observed elements. However, since the light elements are not detectable with the applied measurement conditions, it cannot be definitely stated if plutonium is the main element present in the sample. The isosurfaces are calculated at 20 % of maximum intensity for each element. Please note that the isosurfaces on the drawing are transparent. Changes in the spatial distribution of Pu, Fe, and Ti within the particle are shown in Fig. 2a, 2b, and 2c. Distinct elemental patterns are clearly visible at the higher concentration levels. The distributions of Cr, Cu, and Pb were also reconstructed but the results are not presented here. As it is shown in Fig. 1, the correlation between elements is good at low concentrations but the maxima of concentrations are not strongly correlated (see Fig. 2.). In general, the particle is inhomogeneous in terms of its elemental composition. Similar inhomogeneities were found for other particles with Pu identified as a major element in three of the six particles examined.

  12. 3D Imaging of Nanoparticle Distribution in Biological Tissue by Laser-Induced Breakdown Spectroscopy

    NASA Astrophysics Data System (ADS)

    Gimenez, Y.; Busser, B.; Trichard, F.; Kulesza, A.; Laurent, J. M.; Zaun, V.; Lux, F.; Benoit, J. M.; Panczer, G.; Dugourd, P.; Tillement, O.; Pelascini, F.; Sancey, L.; Motto-Ros, V.

    2016-07-01

    Nanomaterials represent a rapidly expanding area of research with huge potential for future medical applications. Nanotechnology indeed promises to revolutionize diagnostics, drug delivery, gene therapy, and many other areas of research. For any biological investigation involving nanomaterials, it is crucial to study the behavior of such nano-objects within tissues to evaluate both their efficacy and their toxicity. Here, we provide the first account of 3D label-free nanoparticle imaging at the entire-organ scale. The technology used is known as laser-induced breakdown spectroscopy (LIBS) and possesses several advantages such as speed of operation, ease of use and full compatibility with optical microscopy. We then used two different but complementary approaches to achieve 3D elemental imaging with LIBS: a volume reconstruction of a sliced organ and in-depth analysis. This proof-of-concept study demonstrates the quantitative imaging of both endogenous and exogenous elements within entire organs and paves the way for innumerable applications.

  13. Regional salt distribution from 3D data across the South Additions, offshore Louisiana

    SciTech Connect

    Jamieson, G.A. )

    1996-01-01

    A contiguous 3D dataset comprising 20 surveys covering over 800 OCS blocks in the offshore Louisiana South Additions region formed the primary database for a regional interpretation of top and base salt surfaces. The interpretation was performed on a 800m by 800m grid of 3D time migrated lines extracted from each survey and loaded into a single project on a workstation. After completing the interpretation the top and base salt horizons were depth converted, incorporating representative well velocity information across the study area. The use of 3D data has significantly improved interpretation confidence, particularly of the base salt, compared to 2D data, which, to date, has been the most commonly utilized regional tool. However, 2D data suffers from out-of-plane effects which can lead to erroneous interpretations of the base of salt and deep welds. A number of significant regional salt-related features and trends have been identified from the top and base salt time and depth maps. Significant identified features on the base of salt and below include keels, welds, fault zones and possible ramps which, in places, display significantly differing trends to those of the suprasalt section. The 3D data allows the mapping of feeders associated with large counter-regional fault systems down to extreme depths, in places to over 7 kms, as well as the location of feeder stock and wall locations beneath salt canopies. This has shown that many large sheets comprise several salt masses which have coalesced along suture zones, for example in the Vermilion and Ship Shoal regions.

  14. Regional salt distribution from 3D data across the South Additions, offshore Louisiana

    SciTech Connect

    Jamieson, G.A.

    1996-12-31

    A contiguous 3D dataset comprising 20 surveys covering over 800 OCS blocks in the offshore Louisiana South Additions region formed the primary database for a regional interpretation of top and base salt surfaces. The interpretation was performed on a 800m by 800m grid of 3D time migrated lines extracted from each survey and loaded into a single project on a workstation. After completing the interpretation the top and base salt horizons were depth converted, incorporating representative well velocity information across the study area. The use of 3D data has significantly improved interpretation confidence, particularly of the base salt, compared to 2D data, which, to date, has been the most commonly utilized regional tool. However, 2D data suffers from out-of-plane effects which can lead to erroneous interpretations of the base of salt and deep welds. A number of significant regional salt-related features and trends have been identified from the top and base salt time and depth maps. Significant identified features on the base of salt and below include keels, welds, fault zones and possible ramps which, in places, display significantly differing trends to those of the suprasalt section. The 3D data allows the mapping of feeders associated with large counter-regional fault systems down to extreme depths, in places to over 7 kms, as well as the location of feeder stock and wall locations beneath salt canopies. This has shown that many large sheets comprise several salt masses which have coalesced along suture zones, for example in the Vermilion and Ship Shoal regions.

  15. The Relationship between Oxygen A-band Photon Pathlength Distributions and 3D Structures of Heating Rate Profiles

    NASA Astrophysics Data System (ADS)

    Song, L.; Min, Q.

    2012-12-01

    Broadband heating directly drives the global atmospheric and oceanic circulation and its vertical profiles strongly depend upon cloud three-dimensional (3D) structures. Due to the complexity of cloud 3D problems and the difficulties in observations of broadband heating rate profiles (BBHRP), there are still large uncertainties in the relationship of clouds, radiation and climate feedback. Oxygen A-band photon pathlength distributions (PPLD) contain rich information about the 3D structures of clouds and BBHRP and can be observed by both ground based and space based measurements. Therefore, it is meaningful to explore the possibility of connecting A-band PPLD and BBHRP and consequently to describe the internal relationship between them together with the cloud 3D effects on BBHRP. A 3D Monte Carlo radiative transfer model is applied to simulate solar broadband heating rate profiles and oxygen A-band photon pathlength distributions of several ideal cloud fields and two typical cloud fields generated by cloud resolving model (CRM). Principal components (PCs) and the first four moments are selected to represent the vertical structures of BBHRP and PPLD, respectively. In ideal cloud fields, the moments show clear constraint to PCs of BBHRP. The results demonstrate the feasibility to describe the vertical structures of BBHRP by PPLD. The relationship between moments and PCs turns complicated in CRM cloud fields due to the composition of various 3D effects. However, detailed analysis still show that the moments, the PCs and total cloud optical depth are effective factors in defining BBHRP, especially for the vertical structures of relative low clouds. Further, a statistical fitting between the PCs and the moments by a two-layer neural network is applied to provide a quantitative representation of the linkages.

  16. Role of surfactant during microemulsion photopolymerization for the creation of three-dimensional (3D) liquid crystal elastomer microsphere spatial cell scaffolds

    NASA Astrophysics Data System (ADS)

    Hegmann, Elda; Bera, Tanmay; Malcuit, Christopher; Clements, Robert

    2016-06-01

    Three-dimensional (3D) cell scaffolds based on connected nematic liquid crystal elastomer microsphere architectures support the attachment and proliferation of C2C12 myoblasts, neuroblastomas (SHSY5Y) and human dermal fibroblasts (hDF). The microsphere spatial cell scaffolds were prepared by an oil-in-water microemulsion photopolymerization of reactive nematic mesogens in the presence of various surfactants, and the as-prepared scaffold constructs are composed of smooth surface microspheres with diameter ranging from 10 to 30 μm. We here investigate how the nature and type of surfactant used during the microemulsion photopolymerization impacts both the size and size distribution of the resulting microspheres as well as their surface morphology, i.e. the surface roughness.

  17. Gamma Knife 3-D dose distribution near the area of tissue inhomogeneities by normoxic gel dosimetry

    SciTech Connect

    Isbakan, Fatih; Uelgen, Yekta; Bilge, Hatice; Ozen, Zeynep; Agus, Onur; Buyuksarac, Bora

    2007-05-15

    The accuracy of the Leksell GammaPlan registered , the dose planning system of the Gamma Knife Model-B, was evaluated near tissue inhomogeneities, using the gel dosimetry method. The lack of electronic equilibrium around the small-diameter gamma beams can cause dose calculation errors in the neighborhood of an air-tissue interface. An experiment was designed to investigate the effects of inhomogeneity near the paranosal sinuses cavities. The homogeneous phantom was a spherical glass balloon of 16 cm diameter, filled with MAGIC gel; i.e., the normoxic polymer gel. Two hollow PVC balls of 2 cm radius, filled with N{sub 2} gas, represented the air cavities inside the inhomogeneous phantom. For dose calibration purposes, 100 ml gel-containing vials were irradiated at predefined doses, and then scanned in a MR unit. Linearity was observed between the delivered dose and the reciprocal of the T2 relaxation time constant of the gel. Dose distributions are the results of a single shot of irradiation, obtained by collimating all 201 cobalt sources to a known target in the phantom. Both phantoms were irradiated at the same dose level at the same coordinates. Stereotactic frames and fiducial markers were attached to the phantoms prior to MR scanning. The dose distribution predicted by the Gamma Knife planning system was compared with that of the gel dosimetry. As expected, for the homogeneous phantom the isodose diameters measured by the gel dosimetry and the GammaPlan registered differed by 5% at most. However, with the inhomogeneous phantom, the dose maps in the axial, coronal and sagittal planes were spatially different. The diameters of the 50% isodose curves differed 43% in the X axis and 32% in the Y axis for the Z=90 mm axial plane; by 44% in the X axis and 24% in the Z axis for the Y=90 mm coronal plane; and by 32% in the Z axis and 42% in the Y axis for the X=92 mm sagittal plane. The lack of ability of the GammaPlan registered to predict the rapid dose fall off, due

  18. 3-D ion distribution and evolution in storm-time RC Retrieved from TWINS ENA by differential voxel CT technique

    NASA Astrophysics Data System (ADS)

    Ma, S.; Yan, W.; Xu, L.

    2013-12-01

    The quantitative retrieval of the 3-D spatial distribution of the parent energetic ions of ENA from a 2-D ENA image is a quite challenge task. The Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) mission of NASA is the first constellation to perform stereoscopic magnetospheric imaging of energetic neutral atoms (ENA) from a pair of spacecraft flying on two widely-separated Molniya orbits. TWINS provides a unique opportunity to retrieve the 3-D distribution of ions in the ring current (RC) by using a volumetric pixel (voxel) CT inversion method. In this study the voxel CT method is implemented for a series of differential ENA fluxes averaged over about 6 to 7 sweeps (corresponding to a time period of about 9 min.) at different energy levels ranging from 5 to 100 keV, obtained simultaneously by the two satellites during the main phase of a great magnetic storm with minimum Sym-H of -156 nT on 24-25 October 2011. The data were selected to span a period about 50 minutes during which a large substorm was undergoing its expansion phase first and then recovery. The ENA species of O and H are distinguished for some time-segments by analyzing the signals of pulse heights of second electrons emitted from the carbon foil and impacted on the MCP detector in the TWINS sensors. In order to eliminate the possible influence on retrieval induced by instrument bias error, a differential voxel CT technique is applied. The flux intensity of the ENAs' parent ions in the RC has been obtained as a function of energy, L value, MLT sector and latitude, along with their time evolution during the storm-time substorm expansion phase. Forward calculations proved the reliability of the retrieved results. It shows that the RC is highly asymmetric, with a major concentration in the midnight to dawn sector for equatorial latitudes. Halfway through the substorm expansion there occurred a large enhancement of equatorial ion flux at lower energy (5 keV) in the dusk sector, with narrow extent

  19. Linking microscopic spatial patterns of tissue destruction in emphysema to macroscopic decline in stiffness using a 3D computational model.

    PubMed

    Parameswaran, Harikrishnan; Majumdar, Arnab; Suki, Béla

    2011-04-01

    Pulmonary emphysema is a connective tissue disease characterized by the progressive destruction of alveolar walls leading to airspace enlargement and decreased elastic recoil of the lung. However, the relationship between microscopic tissue structure and decline in stiffness of the lung is not well understood. In this study, we developed a 3D computational model of lung tissue in which a pre-strained cuboidal block of tissue was represented by a tessellation of space filling polyhedra, with each polyhedral unit-cell representing an alveolus. Destruction of alveolar walls was mimicked by eliminating faces that separate two polyhedral either randomly or in a spatially correlated manner, in which the highest force bearing walls were removed at each step. Simulations were carried out to establish a link between the geometries that emerged and the rate of decline in bulk modulus of the tissue block. The spatially correlated process set up by the force-based destruction lead to a significantly faster rate of decline in bulk modulus accompanied by highly heterogeneous structures than the random destruction pattern. Using the Karhunen-Loève transformation, an estimator of the change in bulk modulus from the first four moments of airspace cell volumes was setup. Simulations were then obtained for tissue destruction with different idealized alveolar geometry, levels of pre-strain, linear and nonlinear elasticity assumptions for alveolar walls and also mixed destruction patterns where both random and force-based destruction occurs simultaneously. In all these cases, the change in bulk modulus from cell volumes was accurately estimated. We conclude that microscopic structural changes in emphysema and the associated decline in tissue stiffness are linked by the spatial pattern of the destruction process.

  20. SVR learning-based spatiotemporal fuzzy logic controller for nonlinear spatially distributed dynamic systems.

    PubMed

    Zhang, Xian-Xia; Jiang, Ye; Li, Han-Xiong; Li, Shao-Yuan

    2013-10-01

    A data-driven 3-D fuzzy-logic controller (3-D FLC) design methodology based on support vector regression (SVR) learning is developed for nonlinear spatially distributed dynamic systems. Initially, the spatial information expression and processing as well as the fuzzy linguistic expression and rule inference of a 3-D FLC are integrated into spatial fuzzy basis functions (SFBFs), and then the 3-D FLC can be depicted by a three-layer network structure. By relating SFBFs of the 3-D FLC directly to spatial kernel functions of an SVR, an equivalence relationship of the 3-D FLC and the SVR is established, which means that the 3-D FLC can be designed with the help of the SVR learning. Subsequently, for an easy implementation, a systematic SVR learning-based 3-D FLC design scheme is formulated. In addition, the universal approximation capability of the proposed 3-D FLC is presented. Finally, the control of a nonlinear catalytic packed-bed reactor is considered as an application to demonstrate the effectiveness of the proposed 3-D FLC.

  1. Salt distribution in the Louisiana South Additions area from 3D seismic data

    SciTech Connect

    Jamieson, G.A.

    1996-12-31

    This paper outlines some preliminary observations based on a large interpretation project that was carried out with a grid of 3D time migrated seismic data, covering over 7,500 mi{sup 2} of the South Additions region of offshore Louisiana. Depth migrated data, covering a smaller subset of the study area, was also utilized in the interpretation. Top and base of salt were interpreted and the resulting maps have identified patterns of salt and weld geometry that show some regional trends. Historically, 2D time migrated seismic has been the primary dataset of most of the published regional salt studies. This paper focuses on areas where 3D time migrated data potentially shows most improvement over 2D data, specifically in the subsalt regions. In particular, relationships between base-of-salt keels, welds, basins, regional faulting and basement architecture are investigated. A generalized model is outlined to help explain the current salt geometry in the study area and comparisons are made with recently published salt evolution models.

  2. 3D Imaging of Nanoparticle Distribution in Biological Tissue by Laser-Induced Breakdown Spectroscopy

    PubMed Central

    Gimenez, Y.; Busser, B.; Trichard, F.; Kulesza, A.; Laurent, J. M.; Zaun, V.; Lux, F.; Benoit, J. M.; Panczer, G.; Dugourd, P.; Tillement, O.; Pelascini, F.; Sancey, L.; Motto-Ros, V.

    2016-01-01

    Nanomaterials represent a rapidly expanding area of research with huge potential for future medical applications. Nanotechnology indeed promises to revolutionize diagnostics, drug delivery, gene therapy, and many other areas of research. For any biological investigation involving nanomaterials, it is crucial to study the behavior of such nano-objects within tissues to evaluate both their efficacy and their toxicity. Here, we provide the first account of 3D label-free nanoparticle imaging at the entire-organ scale. The technology used is known as laser-induced breakdown spectroscopy (LIBS) and possesses several advantages such as speed of operation, ease of use and full compatibility with optical microscopy. We then used two different but complementary approaches to achieve 3D elemental imaging with LIBS: a volume reconstruction of a sliced organ and in-depth analysis. This proof-of-concept study demonstrates the quantitative imaging of both endogenous and exogenous elements within entire organs and paves the way for innumerable applications. PMID:27435424

  3. Spatial variability and reproducibility of GABA-edited MEGA-LASER 3D-MRSI in the brain at 3 T.

    PubMed

    Hnilicová, Petra; Považan, Michal; Strasser, Bernhard; Andronesi, Ovidiu C; Gajdošík, Martin; Dydak, Ulrike; Ukropec, Jozef; Dobrota, Dušan; Trattnig, Siegfried; Bogner, Wolfgang

    2016-11-01

    The reproducibility of gamma-aminobutyric acid (GABA) quantification results, obtained with MRSI, was determined on a 3 T MR scanner in healthy adults. In this study, a spiral-encoded, GABA-edited, MEGA-LASER MRSI sequence with real-time motion-scanner-instability corrections was applied for robust 3D mapping of neurotransmitters in the brain. In particular, the GABA(+) (i.e. GABA plus macromolecule contamination) and Glx (i.e. glutamate plus glutamine contamination) signal was measured. This sequence enables 3D-MRSI with about 3 cm(3) nominal resolution in about 20 min. Since reliable quantification of GABA is challenging, the spatial distribution of the inter-subject and intra-subject variability of GABA(+) and Glx levels was studied via test-retest assessment in 14 healthy volunteers (seven men-seven women). For both inter-subject and intra-subject repeated measurement sessions a low coefficient of variation (CV) and a high intraclass correlation coefficient (ICC) were found for GABA(+) and Glx ratios across all evaluated voxels (intra-/inter-subject: GABA(+) ratios, CV ~ 8%-ICC > 0.75; Glx ratios, CV ~ 6%-ICC > 0.70). The same was found in selected brain regions for Glx ratios versus GABA(+) ratios (CV varied from about 5% versus about 8% in occipital and parietal regions, to about 8% versus about 10% in the frontal area, thalamus, and basal ganglia). These results provide evidence that 3D mapping of GABA(+) and Glx using the described methodology provides high reproducibility for application in clinical and neuroscientific studies.

  4. Low-cost real-time 3D PC distributed-interactive-simulation (DIS) application for C4I

    NASA Astrophysics Data System (ADS)

    Gonthier, David L.; Veron, Harry

    1998-04-01

    A 3D Distributed Interactive Simulation (DIS) application was developed and demonstrated in a PC environment. The application is capable of running in the stealth mode or as a player which includes battlefield simulations, such as ModSAF. PCs can be clustered together, but not necessarily collocated, to run a simulation or training exercise on their own. A 3D perspective view of the battlefield is displayed that includes terrain, trees, buildings and other objects supported by the DIS application. Screen update rates of 15 to 20 frames per second have been achieved with fully lit and textured scenes thus providing high quality and fast graphics. A complete PC system can be configured for under $2,500. The software runs under Windows95 and WindowsNT. It is written in C++ and uses a commercial API called RenderWare for 3D rendering. The software uses Microsoft Foundation classes and Microsoft DirectPlay for joystick input. The RenderWare libraries enhance the performance through optimization for MMX and the Pentium Pro processor. The RenderWare and the Righteous 3D graphics board from Orchid Technologies with an advertised rendering rate of up to 2 million texture mapped triangles per second. A low-cost PC DIS simulator that can partake in a real-time collaborative simulation with other platforms is thus achieved.

  5. SOLWEIG 1.0--modelling spatial variations of 3D radiant fluxes and mean radiant temperature in complex urban settings.

    PubMed

    Lindberg, Fredrik; Holmer, Björn; Thorsson, Sofia

    2008-09-01

    The mean radiant temperature, T(mrt), which sums up all shortwave and longwave radiation fluxes (both direct and reflected) to which the human body is exposed is one of the key meteorological parameters governing human energy balance and the thermal comfort of man. In this paper, a new radiation model (SOLWEIG 1.0), which simulates spatial variations of 3D radiation fluxes and T(mrt) in complex urban settings, is presented. The T(mrt) is derived by modelling shortwave and longwave radiation fluxes in six directions (upward, downward and from the four cardinal points) and angular factors. The model requires a limited number of inputs, such as direct, diffuse and global shortwave radiation, air temperature, relative humidity, urban geometry and geographical information (latitude, longitude and elevation). The model was evaluated using 7 days of integral radiation measurements at two sites with different building geometries--a large square and a small courtyard in Göteborg, Sweden (57 degrees N)--across different seasons and in various weather conditions. The evaluation reveals good agreement between modelled and measured values of T(mrt), with an overall good correspondence of R (2) = 0.94, (p < 0.01, RMSE = 4.8 K). SOLWEIG 1.0 is still under development. Future work will incorporate a vegetation scheme, as well as an improvement of the estimation of fluxes from the four cardinal points.

  6. Characterizing 3D grain size distributions from 2D sections in mylonites using a modified version of the Saltykov method

    NASA Astrophysics Data System (ADS)

    Lopez-Sanchez, Marco; Llana-Fúnez, Sergio

    2016-04-01

    The understanding of creep behaviour in rocks requires knowledge of 3D grain size distributions (GSD) that result from dynamic recrystallization processes during deformation. The methods to estimate directly the 3D grain size distribution -serial sectioning, synchrotron or X-ray-based tomography- are expensive, time-consuming and, in most cases and at best, challenging. This means that in practice grain size distributions are mostly derived from 2D sections. Although there are a number of methods in the literature to derive the actual 3D grain size distributions from 2D sections, the most popular in highly deformed rocks is the so-called Saltykov method. It has though two major drawbacks: the method assumes no interaction between grains, which is not true in the case of recrystallised mylonites; and uses histograms to describe distributions, which limits the quantification of the GSD. The first aim of this contribution is to test whether the interaction between grains in mylonites, i.e. random grain packing, affects significantly the GSDs estimated by the Saltykov method. We test this using the random resampling technique in a large data set (n = 12298). The full data set is built from several parallel thin sections that cut a completely dynamically recrystallized quartz aggregate in a rock sample from a Variscan shear zone in NW Spain. The results proved that the Saltykov method is reliable as long as the number of grains is large (n > 1000). Assuming that a lognormal distribution is an optimal approximation for the GSD in a completely dynamically recrystallized rock, we introduce an additional step to the Saltykov method, which allows estimating a continuous probability distribution function of the 3D grain size population. The additional step takes the midpoints of the classes obtained by the Saltykov method and fits a lognormal distribution with a trust region using a non-linear least squares algorithm. The new protocol is named the two-step method. The

  7. Detection of infarct lesions from single MRI modality using inconsistency between voxel intensity and spatial location--a 3-D automatic approach.

    PubMed

    Shen, Shan; Szameitat, André J; Sterr, Annette

    2008-07-01

    Detection of infarct lesions using traditional segmentation methods is always problematic due to intensity similarity between lesions and normal tissues, so that multispectral MRI modalities were often employed for this purpose. However, the high costs of MRI scan and the severity of patient conditions restrict the collection of multiple images. Therefore, in this paper, a new 3-D automatic lesion detection approach was proposed, which required only a single type of anatomical MRI scan. It was developed on a theory that, when lesions were present, the voxel-intensity-based segmentation and the spatial-location-based tissue distribution should be inconsistent in the regions of lesions. The degree of this inconsistency was calculated, which indicated the likelihood of tissue abnormality. Lesions were identified when the inconsistency exceeded a defined threshold. In this approach, the intensity-based segmentation was implemented by the conventional fuzzy c-mean (FCM) algorithm, while the spatial location of tissues was provided by prior tissue probability maps. The use of simulated MRI lesions allowed us to quantitatively evaluate the performance of the proposed method, as the size and location of lesions were prespecified. The results showed that our method effectively detected lesions with 40-80% signal reduction compared to normal tissues (similarity index > 0.7). The capability of the proposed method in practice was also demonstrated on real infarct lesions from 15 stroke patients, where the lesions detected were in broad agreement with true lesions. Furthermore, a comparison to a statistical segmentation approach presented in the literature suggested that our 3-D lesion detection approach was more reliable. Future work will focus on adapting the current method to multiple sclerosis lesion detection.

  8. Exterior 3D lamb problem: Harmonic load distributed over a surface

    NASA Astrophysics Data System (ADS)

    Il'yasov, Kh. Kh.; Kravtsov, A. V.; Kuznetsov, S. V.; Sekerzh-Zen'kovich, S. Ya.

    2016-06-01

    The solutions of the exterior Lamb problem with a distributed harmonic surface load acting on the boundary of an elastic half-space are studied. A load normal to the surface and distributed over the surface as the Poisson kernel is considered. The solution is constructed with the use of integral transforms and the finite-element method.

  9. A Novel 3D Multilateration Sensor Using Distributed Ultrasonic Beacons for Indoor Navigation

    PubMed Central

    Kapoor, Rohan; Ramasamy, Subramanian; Gardi, Alessandro; Bieber, Chad; Silverberg, Larry; Sabatini, Roberto

    2016-01-01

    Navigation and guidance systems are a critical part of any autonomous vehicle. In this paper, a novel sensor grid using 40 KHz ultrasonic transmitters is presented for adoption in indoor 3D positioning applications. In the proposed technique, a vehicle measures the arrival time of incoming ultrasonic signals and calculates the position without broadcasting to the grid. This system allows for conducting silent or covert operations and can also be used for the simultaneous navigation of a large number of vehicles. The transmitters and receivers employed are first described. Transmission lobe patterns and receiver directionality determine the geometry of transmitter clusters. Range and accuracy of measurements dictate the number of sensors required to navigate in a given volume. Laboratory experiments were performed in which a small array of transmitters was set up and the sensor system was tested for position accuracy. The prototype system is shown to have a 1-sigma position error of about 16 cm, with errors between 7 and 11 cm in the local horizontal coordinates. This research work provides foundations for the future development of ultrasonic navigation sensors for a variety of autonomous vehicle applications. PMID:27740604

  10. Differences in 3D dose distributions due to calculation method of voxel S-values and the influence of image blurring in SPECT

    NASA Astrophysics Data System (ADS)

    Pacilio, Massimiliano; Amato, Ernesto; Lanconelli, Nico; Basile, Chiara; Torres, Leonel Alberto; Botta, Francesca; Ferrari, Mahila; Cornejo Diaz, Nestor; Coca Perez, Marco; Fernández, María; Lassmann, Michael; Vergara Gil, Alex; Cremonesi, Marta

    2015-03-01

    This study compares 3D dose distributions obtained with voxel S values (VSVs) for soft tissue, calculated by several methods at their current state-of-the-art, varying the degree of image blurring. The methods were: 1) convolution of Dose Point Kernel (DPK) for water, using a scaling factor method; 2) an analytical model (AM), fitting the deposited energy as a function of the source-target distance; 3) a rescaling method (RSM) based on a set of high-resolution VSVs for each isotope; 4) local energy deposition (LED). VSVs calculated by direct Monte Carlo simulations were assumed as reference. Dose distributions were calculated considering spheroidal clusters with various sizes (251, 1237 and 4139 voxels of 3 mm size), uniformly filled with 131I, 177Lu, 188Re or 90Y. The activity distributions were blurred with Gaussian filters of various widths (6, 8 and 12 mm). Moreover, 3D-dosimetry was performed for 10 treatments with 90Y derivatives. Cumulative Dose Volume Histograms (cDVHs) were compared, studying the differences in D95%, D50% or Dmax (ΔD95%, ΔD50% and ΔDmax) and dose profiles. For unblurred spheroidal clusters, ΔD95%, ΔD50% and ΔDmax were mostly within some percents, slightly higher for 177Lu with DPK (8%) and RSM (12%) and considerably higher for LED (ΔD95% up to 59%). Increasing the blurring, differences decreased and also LED yielded very similar results, but D95% and D50% underestimations between 30-60% and 15-50%, respectively (with respect to 3D-dosimetry with unblurred distributions), were evidenced. Also for clinical images (affected by blurring as well), cDVHs differences for most methods were within few percents, except for slightly higher differences with LED, and almost systematic for dose profiles with DPK (-1.2%), AM (-3.0%) and RSM (4.5%), whereas showed an oscillating trend with LED. The major concern for 3D-dosimetry on clinical SPECT images is more strongly represented by image blurring than by differences among the VSVs

  11. Differences in 3D dose distributions due to calculation method of voxel S-values and the influence of image blurring in SPECT.

    PubMed

    Pacilio, Massimiliano; Amato, Ernesto; Lanconelli, Nico; Basile, Chiara; Torres, Leonel Alberto; Botta, Francesca; Ferrari, Mahila; Diaz, Nestor Cornejo; Perez, Marco Coca; Fernández, María; Lassmann, Michael; Gil, Alex Vergara; Cremonesi, Marta

    2015-03-07

    This study compares 3D dose distributions obtained with voxel S values (VSVs) for soft tissue, calculated by several methods at their current state-of-the-art, varying the degree of image blurring. The methods were: 1) convolution of Dose Point Kernel (DPK) for water, using a scaling factor method; 2) an analytical model (AM), fitting the deposited energy as a function of the source-target distance; 3) a rescaling method (RSM) based on a set of high-resolution VSVs for each isotope; 4) local energy deposition (LED). VSVs calculated by direct Monte Carlo simulations were assumed as reference. Dose distributions were calculated considering spheroidal clusters with various sizes (251, 1237 and 4139 voxels of 3 mm size), uniformly filled with (131)I, (177)Lu, (188)Re or (90)Y. The activity distributions were blurred with Gaussian filters of various widths (6, 8 and 12 mm). Moreover, 3D-dosimetry was performed for 10 treatments with (90)Y derivatives. Cumulative Dose Volume Histograms (cDVHs) were compared, studying the differences in D95%, D50% or Dmax (ΔD95%, ΔD50% and ΔDmax) and dose profiles.For unblurred spheroidal clusters, ΔD95%, ΔD50% and ΔDmax were mostly within some percents, slightly higher for (177)Lu with DPK (8%) and RSM (12%) and considerably higher for LED (ΔD95% up to 59%). Increasing the blurring, differences decreased and also LED yielded very similar results, but D95% and D50% underestimations between 30-60% and 15-50%, respectively (with respect to 3D-dosimetry with unblurred distributions), were evidenced. Also for clinical images (affected by blurring as well), cDVHs differences for most methods were within few percents, except for slightly higher differences with LED, and almost systematic for dose profiles with DPK (-1.2%), AM (-3.0%) and RSM (4.5%), whereas showed an oscillating trend with LED.The major concern for 3D-dosimetry on clinical SPECT images is more strongly represented by image blurring than by differences among the VSVs

  12. Modeling the spatial and temporal population dynamics of the copepod Centropages typicus in the northwestern Mediterranean Sea during the year 2001 using a 3D ecosystem model

    NASA Astrophysics Data System (ADS)

    Carlotti, F.; Eisenhauer, L.; Campbell, R.; Diaz, F.

    2014-07-01

    The spatio-temporal dynamics of a simulated Centropages typicus (Kröyer) population during the year 2001 at the regional scale of the northwestern Mediterranean Sea are addressed using a 3D coupled physical-biogeochemical model. The setup of the coupled biological model comprises a pelagic plankton ecosystem model and a stage-structured population model forced by the 3D velocity and temperature fields provided by an eddy-resolving regional circulation model. The population model for C. typicus (C. t. below) represents demographic processes through five groups of developmental stages, which depend on underlying individual growth and development processes and are forced by both biotic (prey and predator fields) and abiotic (temperature, advection) factors from the coupled physical-biogeochemical model. The objective is to characterize C. t. ontogenic habitats driven by physical and trophic processes. The annual dynamics are presented for two of the main oceanographic stations in the Gulf of Lions, which are representative of shelf and open sea conditions, while the spatial distributions over the whole area are presented for three dates during the year, in early and late spring and in winter. The simulated spatial patterns of C. t. developmental stages are closely related to mesoscale hydrodynamic features and circulation patterns. The seasonal and spatial distributions on the Gulf of Lions shelf depend on the seasonal interplay between the Rhône river plume, the mesoscale eddies on the shelf and the Northern Current acting as either as a dynamic barrier between the shelf and the open sea or allowing cross-shelf exchanges. In the central gyre of the northwestern Mediterranean Sea, the patchiness of plankton is tightly linked to mesoscale frontal systems, surface eddies and filaments and deep gradients. Due to its flexibility in terms of its diet, C. t. succeeds in maintaining its population in both coastal and offshore areas year round. The simulations suggest that

  13. Angular distribution of Auger electrons due to 3d-shell ionization of krypton

    NASA Technical Reports Server (NTRS)

    Omidvar, K.

    1977-01-01

    Cross sections for electron impact ionization of krypton due to ejection of a 3rd shell electron have been calculated using screened hydrogenic and Hartree-Slater wave functions for target atom. While the total ionization cross sections in the two approximations are within 10% of each other, the Auger electron angular distribution, related to cross sections for specific magnetic quantum numbers of the 3rd electrons, is widely different in the two approximations. The angular distribution due to Hartree-Slater approximation is in excellent agreement with measurement. The physical reason for the discrepancies in the two approximations is explained.

  14. Verification of 3D Dose Distributions of a Beta-Emitting Radionuclide Using PRESAGE^ Dosimeters

    NASA Astrophysics Data System (ADS)

    Crowder, Mandi; Grant, Ryan; Ibbott, Geoff; Wendt, Richard

    2010-11-01

    Liquid Brachytherapy involves the direct administration of a beta-emitting radioactive solution into the selected tissue. The solution does not migrate from the injection point and uses the limited range of beta particles to produce a three-dimensional dose distribution. We simulated distributions by beta-dose kernels and validated those estimates by irradiating PRESAGE^ polyurethane dosimeters that measure the three-dimensional dose distributions by a change in optical density that is proportional to dose. The dosimeters were injected with internal beta-emitting radionuclide yttrium-90, exposed for 5.75 days, imaged with optical tomography, and analyzed with radiotherapy software. Dosimeters irradiated with an electron beam to 2 or 3 Gy were used for calibration. The shapes and dose distributions in the PRESAGE^ dosimeters were consistent with the predicted dose kernels. Our experiments have laid the groundwork for future application to individualized patient therapy by ultimately designing a treatment plan that conforms to the shape of any appropriate tumor.

  15. 3-D parallel program for numerical calculation of gas dynamics problems with heat conductivity on distributed memory computational systems (CS)

    SciTech Connect

    Sofronov, I.D.; Voronin, B.L.; Butnev, O.I.

    1997-12-31

    The aim of the work performed is to develop a 3D parallel program for numerical calculation of gas dynamics problem with heat conductivity on distributed memory computational systems (CS), satisfying the condition of numerical result independence from the number of processors involved. Two basically different approaches to the structure of massive parallel computations have been developed. The first approach uses the 3D data matrix decomposition reconstructed at temporal cycle and is a development of parallelization algorithms for multiprocessor CS with shareable memory. The second approach is based on using a 3D data matrix decomposition not reconstructed during a temporal cycle. The program was developed on 8-processor CS MP-3 made in VNIIEF and was adapted to a massive parallel CS Meiko-2 in LLNL by joint efforts of VNIIEF and LLNL staffs. A large number of numerical experiments has been carried out with different number of processors up to 256 and the efficiency of parallelization has been evaluated in dependence on processor number and their parameters.

  16. Parallel computation of the SAR distribution in a 3D human head model

    NASA Astrophysics Data System (ADS)

    Walendziuk, Wojciech

    2008-01-01

    This work presents a way of parallel computation of the Specific Absorption Rate distribution. The parallel program used in the computation was based on the FDTD (Finite-Difference Time-Domain) method [1,2,3]. In order to establish communication among the computational nodes, the MPI (Message Passing Interface) standard was used [4,5,6]. The presented example of a human head numerical model was built with the use of MRI (Magnetic Resonance Image) pictures.

  17. In vivo 3D measurement of moxifloxacin and gatifloxacin distributions in the mouse cornea using multiphoton microscopy

    NASA Astrophysics Data System (ADS)

    Lee, Seunghun; Lee, Jun Ho; Park, Jin Hyoung; Yoon, Yeoreum; Chung, Wan Kyun; Tchah, Hungwon; Kim, Myoung Joon; Kim, Ki Hean

    2016-05-01

    Moxifloxacin and gatifloxacin are fourth-generation fluoroquinolone antibiotics used in the clinic to prevent or treat ocular infections. Their pharmacokinetics in the cornea is usually measured from extracted ocular fluids or tissues, and in vivo direct measurement is difficult. In this study multiphoton microscopy (MPM), which is a 3D optical microscopic technique based on multiphoton fluorescence, was applied to the measurement of moxifloxacin and gatifloxacin distribution in the cornea. Intrinsic multiphoton fluorescence properties of moxifloxacin and gatifloxacin were characterized, and their distributions in mouse cornea in vivo were measured by 3D MPM imaging. Both moxifloxacin and gatifloxacin had similar multiphoton spectra, while moxifloxacin had stronger fluorescence than gatifloxacin. MPM imaging of mouse cornea in vivo showed (1) moxifloxacin had good penetration through the superficial corneal epithelium, while gatifloxacin had relatively poor penetration, (2) both ophthalmic solutions had high intracellular distribution. In vivo MPM results were consistent with previous studies. This study demonstrates the feasibility of MPM as a method for in vivo direct measurement of moxifloxacin and gatifloxacin in the cornea.

  18. Observations of the 3-D distribution of interplanetary electrons and ions from solar wind plasma to low energy cosmic rays

    NASA Technical Reports Server (NTRS)

    Lin, R. P.; Anderson, K. A.; Ashford, S.; Carlson, C.; Curtis, D.; Ergun, R.; Larson, D.; McFadden, J.; McCarthy, M.; Parks, G. K.

    1995-01-01

    The 3-D Plasma and Energetic Particle instrument on the GGS Wind spacecraft (launched November 1, 1994) is designed to make measurements of the full three-dimensional distribution of suprathermal electrons and ions from solar wind plasma to low energy cosmic rays, with high sensitivity, wide dynamic range, good energy and angular resolution, and high time resolution. Three pairs of double-ended telescopes, each with two or three closely sandwiched passivated ion implanted silicon detectors measure electrons and ions from approximately 20 keV to greater than or equal to 300 keV. Four top-hat symmetrical spherical section electrostatic analyzers with microchannel plate detectors, a large and a small geometric factor analyzer for electrons and a similar pair for ions, cover from approximately 3 eV to 30 keV. We present preliminary observations of the electron and ion distributions in the absence of obvious solar impulsive events and upstream particles. The quiet time electron energy spectrum shows a smooth approximately power law fall-off extending from the halo population at a few hundred eV to well above approximately 100 keV The quiet time ion energy spectrum also shows significant fluxes over this energy range. Detailed 3-D distributions and their temporal variations will be presented.

  19. On Boundary Misorientation Distribution Functions and How to Incorporate them into 3D Models of Microstructural Evolution

    SciTech Connect

    Godfrey, A.W.; Holm, E.A.; Hughes, D.A.; Miodownik, M.

    1998-12-23

    The fundamental difficulties incorporating experimentally obtained-boundary disorientation distributions (BMD) into 3D microstructural models are discussed. An algorithm is described which overcomes these difficulties. The boundary misorientations are treated as a statistical ensemble which is evolved toward the desired BMD using a Monte Carlo method. The application of this algorithm to a number complex arbitrary BMDs shows that the approach is effective for both conserved and non-conserved textures. The algorithm is successfully used to create the BMDs observed in deformation microstructure containing both incidental dislocation boundaries (IDBs) and geometrically necessary boundaries (GNBs).

  20. Effects of Spatial Ability, Gender Differences, and Pictorial Training on Children Using 2-D and 3-D Environments to Recall Landmark Locations from Memory

    ERIC Educational Resources Information Center

    Kopcha, Theodore J.; Otumfuor, Beryl A.; Wang, Lu

    2015-01-01

    This study examines the effects of spatial ability, gender differences, and pictorial training on fourth grade students' ability to recall landmark locations from memory. Ninety-six students used Google Earth over a 3-week period to locate landmarks (3-D) and mark their location on a 2-D topographical map. Analysis of covariance on posttest scores…

  1. 3D and Education

    NASA Astrophysics Data System (ADS)

    Meulien Ohlmann, Odile

    2013-02-01

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

  2. Toward Measuring Galactic Dense Molecular Gas Properties and 3D Distribution with Hi-GAL

    NASA Astrophysics Data System (ADS)

    Zetterlund, Erika; Glenn, Jason; Maloney, Phil

    2016-01-01

    The Herschel Space Observatory's submillimeter dust continuum survey Hi-GAL provides a powerful new dataset for characterizing the structure of the dense interstellar medium of the Milky Way. Hi-GAL observed a 2° wide strip covering the entire 360° of the Galactic plane in broad bands centered at 70, 160, 250, 350, and 500 μm, with angular resolution ranging from 10 to 40 arcseconds. We are adapting a molecular cloud clump-finding algorithm and a distance probability density function distance-determination method developed for the Bolocam Galactic Plane Survey (BGPS) to the Hi-GAL data. Using these methods we expect to generate a database of 105 cloud clumps, derive distance information for roughly half the clumps, and derive precise distances for approximately 20% of them. With five-color photometry and distances, we will measure the cloud clump properties, such as luminosities, physical sizes, and masses, and construct a three-dimensional map of the Milky Way's dense molecular gas distribution.The cloud clump properties and the dense gas distribution will provide critical ground truths for comparison to theoretical models of molecular cloud structure formation and galaxy evolution models that seek to emulate spiral galaxies. For example, such models cannot resolve star formation and use prescriptive recipes, such as converting a fixed fraction of interstellar gas to stars at a specified interstellar medium density threshold. The models should be compared to observed dense molecular gas properties and galactic distributions.As a pilot survey to refine the clump-finding and distance measurement algorithms developed for BGPS, we have identified molecular cloud clumps in six 2° × 2° patches of the Galactic plane, including one in the inner Galaxy along the line of sight through the Molecular Ring and the termination of the Galactic bar and one toward the outer Galaxy. Distances have been derived for the inner Galaxy clumps and compared to Bolocam Galactic Plane

  3. Operator counting and eigenvalue distributions for 3D supersymmetric gauge theories

    NASA Astrophysics Data System (ADS)

    Gulotta, Daniel R.; Herzog, Christopher P.; Pufu, Silviu S.

    2011-11-01

    We give further support for our conjecture relating eigenvalue distributions of the Kapustin-Willett-Yaakov matrix model in the large N limit to numbers of operators in the chiral ring of the corresponding supersymmetric three-dimensional gauge theory. We show that the relation holds for non-critical R-charges and for examples with mathcal{N} = {2} instead of mathcal{N} = {3} supersymmetry where the bifundamental matter fields are nonchiral. We prove that, for non-critical R-charges, the conjecture is equivalent to a relation between the free energy of the gauge theory on a three sphere and the volume of a Sasaki manifold that is part of the moduli space of the gauge theory. We also investigate the consequences of our conjecture for chiral theories where the matrix model is not well understood.

  4. Fast Volumetric Spatial-Spectral MR Imaging of Hyperpolarized 13C-Labeled Compounds using Multiple Echo 3D bSSFP

    PubMed Central

    Perman, William H.; Bhattacharya, Pratip; Leupold, Jochen; Lin, Alexander P.; Harris, Kent C.; Norton, Valerie A.; Hovener, Jan B.; Ross, Brian D.

    2010-01-01

    PURPOSE The goal of this work was to develop a fast 3D chemical shift imaging technique for the non-invasive measurement of hyperpolarized 13C-labeled substrates and metabolic products at low concentration. MATERIALS AND METHODS Multiple echo 3D balanced steady state MR imaging (ME-3DbSSFP) was performed in vitro on a syringe containing hyperpolarized [1,3,3-2H3; 1-13C]2-hydroxyethylpropionate (HEP) adjacent to a 13C-enriched acetate phantom, and in vivo on a rat before and after IV injection of hyperpolarized HEP at 1.5 T. Chemical shift images of the hyperpolarized HEP were derived from the multiple echo data by Fourier transformation along the echoes on a voxel by voxel basis for each slice of the 3D data set. RESULTS ME-3DbSSFP imaging was able to provide chemical shift images of hyperpolarized HEP in vivo, and in a rat with isotropic 7 mm spatial resolution, 93 Hz spectral resolution and 16 second temporal resolution for a period greater than 45 seconds. CONCLUSION Multiple echo 3D bSSFP imaging can provide chemical shift images of hyperpolarized 13C-labeled compounds in vivo with relatively high spatial resolution and moderate spectral resolution. The increased signal-to-noise ratio (SNR) of this 3D technique will enable the detection of hyperpolarized 13C-labeled metabolites at lower concentrations as compared to a 2D technique. PMID:20171034

  5. Effect of 3D stall-cells on the pressure distribution of a laminar NACA64-418 wing

    NASA Astrophysics Data System (ADS)

    Ragni, Daniele; Ferreira, Carlos

    2016-08-01

    A 3D stall-cell flow-field has been studied in a 4.8 aspect-ratio wing obtained by linear extrusion of a laminar NACA64-418 airfoil profile. The span-wise change in the velocity and pressure distribution along the wing has been quantified with respect to the development of cellular structures from 8° to 20° angle of attack. Oil-flow visualizations help localizing the regular cellular pattern in function of the angle of attack. Multi-plane stereoscopic PIV measurements obtained by traversing the entire setup along the wing span show that the flow separation is not span-wise uniform. The combination of different stereoscopic fields into a 3D volume of velocity data allows studying the global effect of the stall-cell pattern on the wing flow. Integration of the experimentally computed pressure gradient from the Navier-Stokes equation is employed to compute the span-wise distribution of the mean surface pressure. Comparison of the results with the ones obtained from pressure taps installed in the wing evidences a span-wise periodic loading on the wing. The periodic loading has maxima confined in the stream-wise direction between the location of the highest airfoil curvature and the one of the airfoil flow separation. Estimation of the periodic loading is found within 2-6 % of the sectional wing lift.

  6. STRUCTURE IN THE 3D GALAXY DISTRIBUTION. II. VOIDS AND WATERSHEDS OF LOCAL MAXIMA AND MINIMA

    SciTech Connect

    Way, M. J.; Gazis, P. R.; Scargle, Jeffrey D. E-mail: PGazis@sbcglobal.net

    2015-01-20

    The major uncertainties in studies of the multi-scale structure of the universe arise not from observational errors but from the variety of legitimate definitions and detection methods for individual structures. To facilitate the study of these methodological dependencies, we have carried out 12 different analyses defining structures in various ways. This has been done in a purely geometrical way by utilizing the HOP algorithm as a unique parameter-free method of assigning groups of galaxies to local density maxima or minima. From three density estimation techniques (smoothing kernels, Bayesian blocks, and self-organizing maps) applied to three data sets (the Sloan Digital Sky Survey Data Release 7, the Millennium simulation, and randomly distributed points) we tabulate information that can be used to construct catalogs of structures connected to local density maxima and minima. We also introduce a void finder that utilizes a method to assemble Delaunay tetrahedra into connected structures and characterizes regions empty of galaxies in the source catalog.

  7. Simultaneous full-field 3-D vibrometry of the human eardrum using spatial-bandwidth multiplexed holography

    PubMed Central

    Khaleghi, Morteza; Guignard, Jérémie; Furlong, Cosme; Rosowski, John J.

    2015-01-01

    Abstract. Holographic interferometric methods typically require the use of three sensitivity vectors in order to obtain three-dimensional (3-D) information. Methods based on multiple directions of illumination have limited applications when studying biological tissues that have temporally varying responses such as the tympanic membrane (TM). Therefore, to measure 3-D displacements in such applications, the measurements along all the sensitivity vectors have to be done simultaneously. We propose a multiple-illumination directions approach to measure 3-D displacements from a single-shot hologram that contains displacement information from three sensitivity vectors. The hologram of an object of interest is simultaneously recorded with three incoherently superimposed pairs of reference and object beams. The incident off-axis angles of the reference beams are adjusted such that the frequency components of the multiplexed hologram are completely separate. Because of the differences in the directions and wavelengths of the reference beams, the positions of each reconstructed image corresponding to each sensitivity vector are different. We implemented a registration algorithm to accurately translate individual components of the hologram into a single global coordinate system to calculate 3-D displacements. The results include magnitudes and phases of 3-D sound-induced motions of a human cadaveric TM at several excitation frequencies showing modal and traveling wave motions on its surface. PMID:25984986

  8. The prediction of transmitted dose distributions using a 3D treatment planning system.

    PubMed

    Reich, P; Bezak, E; Mohammadi, M; Fog, L

    2006-03-01

    Patient dose verification is becoming increasingly important with the advent of new complex radiotherapy techniques such as conformal radiotherapy (CRT) and intensity-modulated radiotherapy (IMRT). An electronic portal imaging device (EPID) has potential application for in vivo dosimetry. In the current work, an EPID has been modelled using a treatment planning system (TPS) to predict transmitted dose maps. A thin slab of RW3 material used to initially represent the EPID. A homogeneous RW3 phantom and the thin RW3 slab placed at a clinical distance away from the phantom were scanned using a CT simulator. The resulting CT images were transferred via DICOM to the TPS and the density of the CT data corresponding to the thin RW3 slab was changed to 1 g/cm3. Transmitted dose maps (TDMs) in the modelled EPID were calculated by the TPS using the collapsed-cone (C-C) convolution superposition (C/S) algorithm. A 6 MV beam was used in the simulation to deliver 300 MU to the homogenous phantom using an isocentric and SSD (source-to-surface) technique. The phantom thickness was varied and the calculated TDMs in the modelled EPID were compared with corresponding measurements obtained from a calibrated scanning liquid-filled ionisation chamber (SLIC) EPID. The two TDMs were compared using the gamma evaluation technique of Low et al. The predicted and measured TDMs agree to within 2 % (averaged over all phantom thicknesses) on the central beam axis. More than 90 % of points in the dose maps (excluding field edges) produce a gamma index less than or equal to 1, for dose difference (averaged over all phantom thicknesses), and distance-to-agreement criteria of 4 %, 3.8 mm, respectively. In addition, the noise level on the central axis in the predicted dose maps is less than 0.1 %. We found that phantom thickness changes of approximately 1 mm, which correspond to dose changes on the central beam axis of less than 0.6 %, can be detected in the predicted transmitted dose distributions.

  9. The influence of the spatial resolution of topographic input data on the accuracy of 3-D UV actinic flux and irradiance calculations

    NASA Astrophysics Data System (ADS)

    Weihs, P.; Wagner, J. E.; Schreier, S. F.; Rieder, H. E.; Angelini, F.; Blumthaler, M.; Fitzka, M.; Gobbi, G. P.; Kift, R.; Kreuter, A.; Simic, S.; Webb, A. R.

    2011-10-01

    The aim of this study was to investigate the influence of the spatial resolution of a digital elevation map (DEM) on the three-dimensional (3-D) radiative transfer performance for both spectral ultraviolet (UV) irradiance and actinic flux at 305 nm. Model simulations were performed for clear sky conditions for three case studies: the first and second one using three sites in the Innsbruck area and the third one using three sites at the Sonnblick Observatory and surrounding area. It was found that DEM resolution may change the altitude at some locations by up to 500 m, resulting in changes in the sky obscured by the horizon of up to 15%. The geographical distribution of UV irradiance and actinic flux shows that with larger pixel size, uncertainties in UV irradiance and actinic flux determination of up to 100% are possible. These large changes in incident irradiance and actinic flux with changing pixel size are strongly connected to shading effects. The effect of DEM pixel size on irradiance and actinic flux was studied at the six locations, and it was found that significant increases in irradiance and actinic flux with increasing DEM pixel size occurred at one valley location at high solar zenith angles in the Innsbruck area as well as for one steep valley location in the Sonnblick area. This increase in irradiance and actinic flux with increasing DEM resolution is most likely to be connected to shading effects affecting the reflections from the surroundings.

  10. The influence of the spatial resolution of topographic input data on the accuracy of 3-D UV actinic flux and irradiance calculations

    NASA Astrophysics Data System (ADS)

    Weihs, P.; Wagner, J. E.; Schreier, S. F.; Rieder, H. E.; Angelini, F.; Blumthaler, M.; Fitzka, M.; Gobbi, G. P.; Kift, R.; Kreuter, A.; Simic, S.; Webb, A. R.

    2012-03-01

    The aim of this study is to investigate the influence of the spatial resolution of a digital elevation map (DEM) on the three-dimensional (3-D) radiative transfer performance for both spectral ultraviolet (UV) irradiance and actinic flux at 305 nm. Model simulations were performed for clear sky conditions for three case studies: the first and second one using three sites in the Innsbruck area and the third one using three sites at the Sonnblick observatory and surrounding area. It was found that the DEM resolution may change the altitude at some locations by up to 500 m, resulting in changes in the sky obscured by the horizon of up to 15%. The geographical distribution of UV irradiance and actinic flux shows that with larger pixel size, uncertainties in UV irradiance and actinic flux determination of up to 100% are possible. These large changes in incident irradiance and actinic flux with changing pixel size are strongly connected to shading effects. The effect of the DEM pixel size on irradiance and actinic flux was studied at the six locations, and it was found that significant increases in irradiance and actinic flux with increasing DEM pixel size occurred at one valley location at high solar zenith angles in the Innsbruck area as well as for one steep valley location in the Sonnblick area. This increase in irradiance and actinic flux with increasing DEM resolution is most likely to be connected to shading effects affecting the reflections from the surroundings.

  11. Comparison of the bubble size distribution in silicate foams using 2D images and 3D x-ray microtomography

    NASA Astrophysics Data System (ADS)

    Robert, Genevieve; Baker, Don R.; Rivers, Mark L.; Allard, Emilie; Larocque, Jeffery

    2004-10-01

    Three silicate glasses were hydrated at high pressure and then heated at atmospheric pressure to exsolve the water into bubbles and create foams. The bubble size distribution in these foams was measured by x-ray microtomography on the GSECARS BM-13 beamline at the Advanced Photon Source. The bubble area distributions were measured in two dimensions using the image slices produced from the microtomography and the software ImageJ. The bubble volume distributions were measured from the three-dimensional tomographic images with the BLOB3D software. We found that careful analysis of the microtomography data in both two and three dimensions was necessary to avoid the physically unrealistic, experimental artifact of identifying and counting many small bubbles whose surfaces were not defined by a septum of glass. When this artifact was avoided the foams demonstrated power-law distributions of bubble sizes in both two and three dimensions. Conversion of the power-law exponents for bubble areas measured in two dimensions to exponents for bubble volumes usually agreed with the measured three dimensional volume exponents. Furthermore, the power-law distributions for bubble volumes typically agree with multiple theories of bubble growth, all of which yield an exponent of 1 for the cumulative bubble volume distribution. The measured bubble volume distributions with exponents near 0.3 can be explained by diffusive growth as proposed by other authors, but distributions with exponents near 1.4 remain to be explained and are the subject of continuing research on the effects of water concentration and melt viscosity on foaming behavior.

  12. Anticipatory Spatial Representation of 3D Regions Explored by Sighted Observers and a Deaf-and-Blind-Observer

    ERIC Educational Resources Information Center

    Intraub, Helene

    2004-01-01

    Viewers who study photographs of scenes tend to remember having seen beyond the boundaries of the view ["boundary extension"; J. Exp. Psychol. Learn. Mem. Cogn. 15 (1989) 179]. Is this a fundamental aspect of scene representation? Forty undergraduates explored bounded regions of six common (3D) scenes, visually or haptically (while blindfolded)…

  13. Spatial distribution of thermal energy in equilibrium.

    PubMed

    Bar-Sinai, Yohai; Bouchbinder, Eran

    2015-06-01

    The equipartition theorem states that in equilibrium, thermal energy is equally distributed among uncoupled degrees of freedom that appear quadratically in the system's Hamiltonian. However, for spatially coupled degrees of freedom, such as interacting particles, one may speculate that the spatial distribution of thermal energy may differ from the value predicted by equipartition, possibly quite substantially in strongly inhomogeneous or disordered systems. Here we show that for systems undergoing simple Gaussian fluctuations around an equilibrium state, the spatial distribution is universally bounded from above by 1/2k(B)T. We further show that in one-dimensional systems with short-range interactions, the thermal energy is equally partitioned even for coupled degrees of freedom in the thermodynamic limit and that in higher dimensions nontrivial spatial distributions emerge. Some implications are discussed.

  14. The spatial distribution of coronae on Venus

    NASA Technical Reports Server (NTRS)

    Squyres, S. W.; Schubert, G.; Bindschadler, D. L.; Janes, D. M.; Moersch, J. E.; Moore, W.; Olson, P.; Ratcliff, J. T.; Stofan, E. R.; Turcotte, D. L.

    1992-01-01

    Coronae on Venus are large, generally circular surface features that have distinctive tectonic, volcanic, and topographic expressions. They range in diameter from less than 200 km to at least 1000 km. Data from the Magellan spacecraft have now allowed complete global mapping of the spatial distribution of coronae on the planet. Unlike impact craters, which show a random (i.e., Poisson) spatial distribution, the distribution of coronae appears to be nonrandom. We investigate the distribution here in detail, and explore its implications in terms of mantle convection and surface modification processes.

  15. Dengue Vectors and their Spatial Distribution

    PubMed Central

    Higa, Yukiko

    2011-01-01

    The distribution of dengue vectors, Ae. aegypti and Ae. albopictus, is affected by climatic factors. In addition, since their life cycles are well adapted to the human environment, environmental changes resulting from human activity such as urbanization exert a great impact on vector distribution. The different responses of Ae. aegypti and Ae albopictus to various environments result in a difference in spatial distribution along north-south and urban-rural gradients, and between the indoors and outdoors. In the north-south gradient, climate associated with survival is an important factor in spatial distribution. In the urban-rural gradient, different distribution reflects a difference in adult niches and is modified by geographic and human factors. The direct response of the two species to the environment around houses is related to different spatial distribution indoors and outdoors. Dengue viruses circulate mainly between human and vector mosquitoes, and the vector presence is a limiting factor of transmission. Therefore, spatial distribution of dengue vectors is a significant concern in the epidemiology of the disease. Current technologies such as GIS, satellite imagery and statistical models allow researchers to predict the spatial distribution of vectors in the changing environment. Although it is difficult to confirm the actual effect of environmental and climate changes on vector abundance and vector-borne diseases, environmental changes caused by humans and human behavioral changes due to climate change can be expected to exert an impact on dengue vectors. Longitudinal monitoring of dengue vectors and viruses is therefore necessary. PMID:22500133

  16. Isoparametric fitting: A method for approximating full-field experimental data distributed on any shaped 3D domain

    NASA Astrophysics Data System (ADS)

    Bruno, Luigi

    2016-12-01

    With the present paper, the author proposes a fitting method for approximating experimental data retrieved from any full-field technique. Unlike most of the fitting procedures, the method works on data distributed on a surface of any shape, and the mathematical model is able to take into account of both the 3D shape of the surface and of the experimental quantity to be fitted. The paper reports all the mathematical steps necessary for applying the method, which was tested on two sets of experimental data obtained by an out-of-plane speckle interferometer working in two different conditions of noise. Experimental results showed the capability of the method to work in presence of high level of noise.

  17. SU-E-T-419: Fabricating Cerrobend Grids with 3D Printing for Spatially Modulated Radiation Therapy: A Feasibility Study

    SciTech Connect

    Zhu, X; Driewer, J; Lei, Y; Zheng, D; Li, S; Zhang, Q; Zhang, M; Zhou, S; Cullip, T; Chang, S

    2015-06-15

    Purpose: Grid therapy has promising applications in the radiation treatment of bulky and large tumors. However, research and applications of grid therapy is limited by the accessibility of the specialized blocks that produce the grid of pencil-like radiation beams. In this study, a Cerrobend grid block was fabricated using a 3D printing technique. Methods: A grid block mold was designed with divergent tubes following beam central rays. The mold was printed using a resin with the working temperature below 230 °C. The melted Cerrobend liquid at 120°oC was cast into the resin mold to yield a block with a thickness of 7.4 cm. The grid had a hexagonal pattern, with each pencil beam diameter of 1.4 cm at the iso-center plane; the distance between the beam centers was 2 cm. The dosimetric properties of the grid block were studied using radiographic film and small field dosimeters. Results: the grid block was fabricated to be mounted at the third accessory mount of a Siemens Oncor linear accelerator. Fabricating a grid block using 3D printing is similar to making cutouts for traditional radiotherapy photon blocks, with the difference being that the mold was created by a 3D printer rather than foam. In this study, the valley-to-peak ratio for a 6MV photon grid beam was 20% at dmax, and 30% at 10 cm depth, respectively. Conclusion: We have demonstrated a novel process for implementing grid radiotherapy using 3D printing techniques. Compared to existing approaches, our technique combines reduced cost, accessibility, and flexibility in customization with efficient delivery. This lays the groundwork for future studies to improve our understanding of the efficacy of grid therapy and apply it to improve cancer treatment.

  18. Computing spatial information from Fourier coefficient distributions.

    PubMed

    Heinz, William F; Werbin, Jeffrey L; Lattman, Eaton; Hoh, Jan H

    2011-05-01

    The spatial relationships between molecules can be quantified in terms of information. In the case of membranes, the spatial organization of molecules in a bilayer is closely related to biophysically and biologically important properties. Here, we present an approach to computing spatial information based on Fourier coefficient distributions. The Fourier transform (FT) of an image contains a complete description of the image, and the values of the FT coefficients are uniquely associated with that image. For an image where the distribution of pixels is uncorrelated, the FT coefficients are normally distributed and uncorrelated. Further, the probability distribution for the FT coefficients of such an image can readily be obtained by Parseval's theorem. We take advantage of these properties to compute the spatial information in an image by determining the probability of each coefficient (both real and imaginary parts) in the FT, then using the Shannon formalism to calculate information. By using the probability distribution obtained from Parseval's theorem, an effective distance from the uncorrelated or most uncertain case is obtained. The resulting quantity is an information computed in k-space (kSI). This approach provides a robust, facile and highly flexible framework for quantifying spatial information in images and other types of data (of arbitrary dimensions). The kSI metric is tested on a 2D Ising model, frequently used as a model for lipid bilayer; and the temperature-dependent phase transition is accurately determined from the spatial information in configurations of the system.

  19. Spatially Distributed Social Complex Networks

    NASA Astrophysics Data System (ADS)

    Frasco, Gerald F.; Sun, Jie; Rozenfeld, Hernán D.; ben-Avraham, Daniel

    2014-01-01

    We propose a bare-bones stochastic model that takes into account both the geographical distribution of people within a country and their complex network of connections. The model, which is designed to give rise to a scale-free network of social connections and to visually resemble the geographical spread seen in satellite pictures of the Earth at night, gives rise to a power-law distribution for the ranking of cities by population size (but for the largest cities) and reflects the notion that highly connected individuals tend to live in highly populated areas. It also yields some interesting insights regarding Gibrat's law for the rates of city growth (by population size), in partial support of the findings in a recent analysis of real data [Rozenfeld et al., Proc. Natl. Acad. Sci. U.S.A. 105, 18702 (2008).]. The model produces a nontrivial relation between city population and city population density and a superlinear relationship between social connectivity and city population, both of which seem quite in line with real data.

  20. RT3D tutorials for GMS users

    SciTech Connect

    Clement, T.P.; Jones, N.L.

    1998-02-01

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

  1. The Relationship between Spatial Visualization Ability and Students' Ability to Model 3D Objects from Engineering Assembly Drawings

    ERIC Educational Resources Information Center

    Branoff, T. J.; Dobelis, M.

    2012-01-01

    Spatial abilities have been used as a predictor of success in several engineering and technology disciplines (Strong & Smith, 2001). In engineering graphics courses, scores on spatial tests have also been used to predict success (Adanez & Velasco, 2002; Leopold, Gorska, & Sorby, 2001). Other studies have shown that some type of…

  2. Reducing Uncertainty in the Distribution of Hydrogeologic Units within Volcanic Composite Units of Pahute Mesa Using High-Resolution 3-D Resistivity Methods, Nevada Test Site, Nevada

    USGS Publications Warehouse

    Rodriguez, Brian D.; Sweetkind, Don; Burton, Bethany L.

    2010-01-01

    The U.S. Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) at their Nevada Site Office (NSO) are addressing groundwater contamination resulting from historical underground nuclear testing through the Environmental Management program and, in particular, the Underground Test Area (UGTA) project. From 1951 to 1992, 828 underground nuclear tests were conducted at the Nevada Test Site (NTS) northwest of Las Vegas (DOE UGTA, 2003). Most of these tests were conducted hundreds of feet above the groundwater table; however, more than 200 of the tests were near, or within, the water table. This underground testing was limited to specific areas of the NTS including Pahute Mesa, Rainier Mesa/Shoshone Mountain, Frenchman Flat, and Yucca Flat. Volcanic composite units make up much of the area within the Pahute Mesa Corrective Action Unit (CAU) at the NTS, Nevada. The extent of many of these volcanic composite units extends throughout and south of the primary areas of past underground testing at Pahute and Rainier Mesas. As situated, these units likely influence the rate and direction of groundwater flow and radionuclide transport. Currently, these units are poorly resolved in terms of their hydrologic properties introducing large uncertainties into current CAU-scale flow and transport models. In 2007, the U.S. Geological Survey (USGS), in cooperation with DOE and NNSA-NSO acquired three-dimensional (3-D) tensor magnetotelluric data at the NTS in Area 20 of Pahute Mesa CAU. A total of 20 magnetotelluric recording stations were established at about 600-m spacing on a 3-D array and were tied to ER20-6 well and other nearby well control (fig. 1). The purpose of this survey was to determine if closely spaced 3-D resistivity measurements can be used to characterize the distribution of shallow (600- to 1,500-m-depth range) devitrified rhyolite lava-flow aquifers (LFA) and zeolitic tuff confining units (TCU) in areas of limited drill hole control on

  3. Intrinsic spatial resolution evaluation of the X'tal cube PET detector based on a 3D crystal block segmented by laser processing.

    PubMed

    Yoshida, Eiji; Tashima, Hideaki; Inadama, Naoko; Nishikido, Fumihiko; Moriya, Takahiro; Omura, Tomohide; Watanabe, Mitsuo; Murayama, Hideo; Yamaya, Taiga

    2013-01-01

    The X'tal cube is a depth-of-interaction (DOI)-PET detector which is aimed at obtaining isotropic resolution by effective readout of scintillation photons from the six sides of a crystal block. The X'tal cube is composed of the 3D crystal block with isotropic resolution and arrays of multi-pixel photon counters (MPPCs). In this study, to fabricate the 3D crystal block efficiently and precisely, we applied a sub-surface laser engraving (SSLE) technique to a monolithic crystal block instead of gluing segmented small crystals. The SSLE technique provided micro-crack walls which carve a groove into a monolithic scintillator block. Using the fabricated X'tal cube, we evaluated its intrinsic spatial resolution to show a proof of concept of isotropic resolution. The 3D grids of 2 mm pitch were fabricated into an 18 × 18 × 18 mm(3) monolithic lutetium yttrium orthosilicate (LYSO) crystal by the SSLE technique. 4 × 4 MPPCs were optically coupled to each surface of the crystal block. The X'tal cube was uniformly irradiated by (22)Na gamma rays, and all of the 3D grids on the 3D position histogram were separated clearly by an Anger-type calculation from the 96-channel MPPC signals. Response functions of the X'tal cube were measured by scanning with a (22)Na point source. The gamma-ray beam with a 1.0 mm slit was scanned in 0.25 mm steps by positioning of the X'tal cube at vertical and 45° incident angles. The average FWHM resolution at both incident angles was 2.1 mm. Therefore, we confirmed the isotropic spatial resolution performance of the X'tal cube.

  4. 3D finite element analysis of nutrient distributions and cell viability in the intervertebral disc: effects of deformation and degeneration.

    PubMed

    Jackson, Alicia R; Huang, Chun-Yuh C; Brown, Mark D; Gu, Wei Yong

    2011-09-01

    The intervertebral disc (IVD) receives important nutrients, such as glucose, from surrounding blood vessels. Poor nutritional supply is believed to play a key role in disc degeneration. Several investigators have presented finite element models of the IVD to investigate disc nutrition; however, none has predicted nutrient levels and cell viability in the disc with a realistic 3D geometry and tissue properties coupled to mechanical deformation. Understanding how degeneration and loading affect nutrition and cell viability is necessary for elucidating the mechanisms of disc degeneration and low back pain. The objective of this study was to analyze the effects of disc degeneration and static deformation on glucose distributions and cell viability in the IVD using finite element analysis. A realistic 3D finite element model of the IVD was developed based on mechano-electrochemical mixture theory. In the model, the cellular metabolic activities and viability were related to nutrient concentrations, and transport properties of nutrients were dependent on tissue deformation. The effects of disc degeneration and mechanical compression on glucose concentrations and cell density distributions in the IVD were investigated. To examine effects of disc degeneration, tissue properties were altered to reflect those of degenerated tissue, including reduced water content, fixed charge density, height, and endplate permeability. Two mechanical loading conditions were also investigated: a reference (undeformed) case and a 10% static deformation case. In general, nutrient levels decreased moving away from the nutritional supply at the disc periphery. Minimum glucose levels were at the interface between the nucleus and annulus regions of the disc. Deformation caused a 6.2% decrease in the minimum glucose concentration in the normal IVD, while degeneration resulted in an 80% decrease. Although cell density was not affected in the undeformed normal disc, there was a decrease in cell

  5. Solar Wind Heating as Revealed from the Variation of 3D Ion Velocity Distributions across the Magnetic Reconnection Exhaust Region

    NASA Astrophysics Data System (ADS)

    He, J.

    2015-12-01

    Magnetic reconnection within current sheet has been regarded as one of the crucial dissipation and heating processes of coherent structures in the solar wind turbulence. Counter-streaming of ions is an important phenomenon in the reconnection exhaust region ranged from the ion diffusion region to the extended outflow region. It has been suggested by theoretical and numerical models that the ions are going to be picked up by the ejecting magnetic field and show larger T_perpendicular than T_parallel, if the guide field is strong enough (in other word, the shear angle is relatively low). The pick-up behavior seems to favor the heating of heavy ions with high mass-to-charge ratio, since the high M/Q ions have larger gyro-period/transit-time and tend to be non-adiabatic more easily. The above statements from theoretical models have not been thoroughly testified in the solar wind observations, though the changes in total temperature and 1D reduced velocity distribution function had been studied. Until now, it remains unclear about the difference of full 3D velocity distribution for the proton and helium ions between the upstream and the exhaust regions. Here, we will analyze the plasma measurement data from WIND/3DP to explore and compare the parallel and perpendicular heating effect of different species of ions. As a preliminary result, the proton is found to show bi-directional streams in its velocity distribution in some reconnection exhaust regions. The thermalization of the counter-streaming protons will be presented. The relation between proton T_parallel/T_perpendicular and guide field strength (or shear angle) will be studied. The velocity distributions of helium ions will be illustrated, which shows the difference of heating effect between different M/Q ratios.

  6. 3D modeling of gas/water distribution in water-bearing carbonate gas reservoirs: the Longwangmiao gas field, China

    NASA Astrophysics Data System (ADS)

    Ou, Chenghua; Li, ChaoChun; Ma, Zhonggao

    2016-10-01

    A water-bearing carbonate gas reservoir is an important natural gas resource being developed worldwide. Due to the long-term water/rock/gas interaction during geological evolution, complex gas/water distribution has formed under the superposed effect of sedimentary facies, reservoir space facies and gravity difference of fluid facies. In view of these challenges, on the basis of the conventional three-stage modeling method, this paper presents a modelling method controlled by four-stage facies to develop 3D model of a water-bearing carbonate gas reservoir. Key to this method is the reservoir property modelling controlled by two-stage facies, and the fluid property modelling controlled by another two-stage facies. The prerequisite of this method is a reliable database obtained from solid geological investigation. On the basis of illustrating the principles of the modelling method controlled by four-stage facies, this paper further implements systematically modeling of the heterogeneous gas/water distribution of the Longwangmiao carbonate formation in the Moxi-Gaoshiti area, Sichuan basin, China.

  7. Comparison of NSTX FIDA, Charge Exchange, and Neutron Fluxes with Calculated Signals Based on CQL3D-FOW Distribution Functions

    NASA Astrophysics Data System (ADS)

    Harvey, R. W.; Petrov, Yu. V.; Kinsey, J. E.; Liu, D.; Heidbrink, W. W.; Taylor, G.; Bonoli, P. T.

    2014-10-01

    Ion distribution function calculations with CQL3D have been substantially advanced through implementation of guiding-center-orbit-based Fokker-Planck Coefficients. The resulting finite-orbit-width (FOW) calculations are carried out with a fast CQL3D-Hybrid-FOW option, and in a slower but neoclassically complete (except no Er yet) CQL3D-FOW option. Good comparison between time-dependent Fast Ion Diagnostic FIDA, NPA, and neutron signals resulting from neutral beaminjection(NBI) and high harmonic fast wave (HHFW) power injected into the NSTX spherical tokamak have been simulated with the CQL3D-Hybrid-FOW, using only the FOW effects on QL diffusion, and particle losses, direct and CX. Comparisons are also made with recent CQL3D-FOW results, as well as between the original FIDA calculation code and a recent fortran version. Supported by USDOE Grants SC0006614, ER54744, and ER44649.

  8. Reconstruction of 4D-CT from a Single Free-Breathing 3D-CT by Spatial-Temporal Image Registration

    PubMed Central

    Wu, Guorong; Wang, Qian; Lian, Jun; Shen, Dinggang

    2011-01-01

    In the radiation therapy of lung cancer, a free-breathing 3D-CT image is usually acquired in the treatment day for image-guided patient setup, by registering with the free-breathing 3D-CT image acquired in the planning day. In this way, the optimal dose plan computed in the planning day can be transferred onto the treatment day for cancer radiotherapy. However, patient setup based on the simple registration of the free-breathing 3D-CT images of the planning and the treatment days may mislead the radiotherapy, since the free-breathing 3D-CT is actually the mixed-phase image, with different slices often acquired from different respiratory phases. Moreover, a 4D-CT that is generally acquired in the planning day for improvement of dose planning is often ignored for guiding patient setup in the treatment day. To overcome these limitations, we present a novel two-step method to reconstruct the 4D-CT from a single free-breathing 3D-CT of the treatment day, by utilizing the 4D-CT model built in the planning day. Specifically, in the first step, we proposed a new spatial-temporal registration algorithm to align all phase images of the 4D-CT acquired in the planning day, for building a 4D-CT model with temporal correspondences established among all respiratory phases. In the second step, we first determine the optimal phase for each slice of the free-breathing (mixed-phase) 3D-CT of the treatment day by comparing with the 4D-CT of the planning day and thus obtain a sequence of partial 3D-CT images for the treatment day, each with only the incomplete image information in certain slices; and then we reconstruct a complete 4D-CT for the treatment day by warping the 4D-CT of the planning day (with complete information) to the sequence of partial 3D-CT images of the treatment day, under the guidance of the 4D-CT model built in the planning day. We have comprehensively evaluated our 4D-CT model building algorithm on a public lung image database, achieving the best registration

  9. Runaway electron distributions obtained with the CQL3D Fokker-Planck code under tokamak disruption conditions

    SciTech Connect

    Harvey, R.W.; Chan, V.S.

    1996-12-31

    Runaway of electrons to high energy during plasma disruptions occurs due to large induced toroidal electric fields which tend to maintain the toroidal plasma current, in accord with Lenz law. This has been observed in many tokamaks. Within the closed flux surfaces, the bounce-averaged CQL3D Fokker-Planck code is well suited to obtain the resulting electron distributions, nonthermal contributions to electrical conductivity, and runaway rates. The time-dependent 2D in momentum-space (p{sub {parallel}} and p{sub {perpendicular}}) distributions axe calculated on a radial array of noncircular flux surfaces, including bounce-averaging of the Fokker-Planck equation to account for toroidal trapping effects. In the steady state, the resulting distributions represent a balance between applied toroidal electric field, relativistic Coulomb collisions, and synchrotron radiation. The code can be run in a mode where the electrons are sourced at low velocity and run off the high velocity edge of the computational mesh, giving runaway rates at steady state. At small minor radius, the results closely match previous results reported by Kulsrud et al. It is found that the runaway rate has a strong dependence on inverse aspect ratio e, decreasing by a factor {approx} 5 as e increases from 0.0 to 0.3. The code can also be run with a radial diffusion and pinching term, simulating radial transport with plasma pinching to maintain a given density profile. Results show a transport reduction of runaways in the plasma center, and an enhancement towards the edge due to the electrons from the plasma center. Avalanching of runaways due to a knock-on electron source is being included.

  10. Development status of a CZT spectrometer prototype with 3D spatial resolution for hard x-ray astronomy

    NASA Astrophysics Data System (ADS)

    Auricchio, N.; Caroli, E.; Basili, A.; Benassi, G.; Budtz Jørgensen, C.; Curado da Silva, R. M.; Del Sordo, S.; Kuvvetli, I.; Milano, L.; Moscatelli, F.; Stephen, J. B.; Zanichelli, M.; Zappettini, A.

    2012-07-01

    The development of new focusing optics based on wide band Laue lenses operating from ~60 keV up to several hundred keV is particularly challenging. This type of hard X-ray or gamma ray optics requires a high performance focal plane detector in order to exploit to the best their intrinsic capabilities. We describe a three dimensional (3D) position sensitive detector prototype suitable as the basic module for a high efficiency Laue lens focal plane detector. This detector configuration is currently under study for use in a balloon payload dedicated to performing a high significance measurement of the polarization status of the Crab between 100 and 500 keV. The prototype is made by packing 8 linear modules, each composed of one basic sensitive unit bonded onto a thin supporting ceramic layer. Each unit is a drift strip detector based on a CZT crystal, irradiated transversally to the electric field direction. The anode is segmented into 8 detection cells, each comprising one collecting strip and 8 surrounding drift strips. The drift strips are biased by a voltage divider. The cathode is divided into 4 horizontal strips for the reconstruction of the Z interaction position. The detector readout electronics is based on RENA-3 ASIC and the data handling system uses a custom electronics based on FPGA to provide the ASIC setting, the event handling logic, and the data acquisition. This paper mainly describes the components and the status of the undergoing activities for the construction of the proposed 3D CZT prototype and shows the results of the electronics tests.

  11. Multicriteria optimization of the spatial dose distribution

    SciTech Connect

    Schlaefer, Alexander; Viulet, Tiberiu; Muacevic, Alexander; Fürweger, Christoph

    2013-12-15

    Purpose: Treatment planning for radiation therapy involves trade-offs with respect to different clinical goals. Typically, the dose distribution is evaluated based on few statistics and dose–volume histograms. Particularly for stereotactic treatments, the spatial dose distribution represents further criteria, e.g., when considering the gradient between subregions of volumes of interest. The authors have studied how to consider the spatial dose distribution using a multicriteria optimization approach.Methods: The authors have extended a stepwise multicriteria optimization approach to include criteria with respect to the local dose distribution. Based on a three-dimensional visualization of the dose the authors use a software tool allowing interaction with the dose distribution to map objectives with respect to its shape to a constrained optimization problem. Similarly, conflicting criteria are highlighted and the planner decides if and where to relax the shape of the dose distribution.Results: To demonstrate the potential of spatial multicriteria optimization, the tool was applied to a prostate and meningioma case. For the prostate case, local sparing of the rectal wall and shaping of a boost volume are achieved through local relaxations and while maintaining the remaining dose distribution. For the meningioma, target coverage is improved by compromising low dose conformality toward noncritical structures. A comparison of dose–volume histograms illustrates the importance of spatial information for achieving the trade-offs.Conclusions: The results show that it is possible to consider the location of conflicting criteria during treatment planning. Particularly, it is possible to conserve already achieved goals with respect to the dose distribution, to visualize potential trade-offs, and to relax constraints locally. Hence, the proposed approach facilitates a systematic exploration of the optimal shape of the dose distribution.

  12. Constraints on 3D fault and fracture distribution in layered volcanic- volcaniclastic sequences from terrestrial LIDAR datasets: Faroe Islands

    NASA Astrophysics Data System (ADS)

    Raithatha, Bansri; McCaffrey, Kenneth; Walker, Richard; Brown, Richard; Pickering, Giles

    2013-04-01

    Hydrocarbon reservoirs commonly contain an array of fine-scale structures that control fluid flow in the subsurface, such as polyphase fracture networks and small-scale fault zones. These structures are unresolvable using seismic imaging and therefore outcrop-based studies have been used as analogues to characterize fault and fracture networks and assess their impact on fluid flow in the subsurface. To maximize recovery and enhance production, it is essential to understand the geometry, physical properties, and distribution of these structures in 3D. Here we present field data and terrestrial LIDAR-derived 3D, photo-realistic virtual outcrops of fault zones at a range of displacement scales (0.001- 4.5 m) within a volcaniclastic sand- and basaltic lava unit sequence in the Faroe Islands. Detailed field observations were used to constrain the virtual outcrop dataset, and a workflow has been developed to build a discrete fracture network (DFN) models in GOCAD® from these datasets. Model construction involves three main stages: (1) Georeferencing and processing of LIDAR datasets; (2) Structural interpretation to discriminate between faults, fractures, veins, and joint planes using CAD software and RiSCAN Pro; and (3) Building a 3D DFN in GOCAD®. To test the validity of this workflow, we focus here on a 4.5 m displacement strike-slip fault zone that displays a complex polymodal fracture network in the inter-layered basalt-volcaniclastic sequence, which is well-constrained by field study. The DFN models support our initial field-based hypothesis that fault zone geometry varies with increasing displacement through volcaniclastic units. Fracture concentration appears to be greatest in the upper lava unit, decreases into the volcaniclastic sediments, and decreases further into the lower lava unit. This distribution of fractures appears to be related to the width of the fault zone and the amount of fault damage on the outcrop. For instance, the fault zone is thicker in

  13. 3D Visualization Development of SIUE Campus

    NASA Astrophysics Data System (ADS)

    Nellutla, Shravya

    Geographic Information Systems (GIS) has progressed from the traditional map-making to the modern technology where the information can be created, edited, managed and analyzed. Like any other models, maps are simplified representations of real world. Hence visualization plays an essential role in the applications of GIS. The use of sophisticated visualization tools and methods, especially three dimensional (3D) modeling, has been rising considerably due to the advancement of technology. There are currently many off-the-shelf technologies available in the market to build 3D GIS models. One of the objectives of this research was to examine the available ArcGIS and its extensions for 3D modeling and visualization and use them to depict a real world scenario. Furthermore, with the advent of the web, a platform for accessing and sharing spatial information on the Internet, it is possible to generate interactive online maps. Integrating Internet capacity with GIS functionality redefines the process of sharing and processing the spatial information. Enabling a 3D map online requires off-the-shelf GIS software, 3D model builders, web server, web applications and client server technologies. Such environments are either complicated or expensive because of the amount of hardware and software involved. Therefore, the second objective of this research was to investigate and develop simpler yet cost-effective 3D modeling approach that uses available ArcGIS suite products and the free 3D computer graphics software for designing 3D world scenes. Both ArcGIS Explorer and ArcGIS Online will be used to demonstrate the way of sharing and distributing 3D geographic information on the Internet. A case study of the development of 3D campus for the Southern Illinois University Edwardsville is demonstrated.

  14. Soil process-oriented modelling of within-field variability based on high-resolution 3D soil type distribution maps.

    NASA Astrophysics Data System (ADS)

    Bönecke, Eric; Lück, Erika; Gründling, Ralf; Rühlmann, Jörg; Franko, Uwe

    2016-04-01

    Today, the knowledge of within-field variability is essential for numerous purposes, including practical issues, such as precision and sustainable soil management. Therefore, process-oriented soil models have been applied for a considerable time to answer question of spatial soil nutrient and water dynamics, although, they can only be as consistent as their variation and resolution of soil input data. Traditional approaches, describe distribution of soil types, soil texture or other soil properties for greater soil units through generalised point information, e.g. from classical soil survey maps. Those simplifications are known to be afflicted with large uncertainties. Varying soil, crop or yield conditions are detected even within such homogenised soil units. However, recent advances of non-invasive soil survey and on-the-go monitoring techniques, made it possible to obtain vertical and horizontal dense information (3D) about various soil properties, particularly soil texture distribution which serves as an essential soil key variable affecting various other soil properties. Thus, in this study we based our simulations on detailed 3D soil type distribution (STD) maps (4x4 m) to adjacently built-up sufficient informative soil profiles including various soil physical and chemical properties. Our estimates of spatial STD are based on high-resolution lateral and vertical changes of electrical resistivity (ER), detected by a relatively new multi-sensor on-the-go ER monitoring device. We performed an algorithm including fuzzy-c-mean (FCM) logic and traditional soil classification to estimate STD from those inverted and layer-wise available ER data. STD is then used as key input parameter for our carbon, nitrogen and water transport model. We identified Pedological horizon depths and inferred hydrological soil variables (field capacity, permanent wilting point) from pedotransferfunctions (PTF) for each horizon. Furthermore, the spatial distribution of soil organic carbon

  15. Spheroid arrays for high-throughput single-cell analysis of spatial patterns and biomarker expression in 3D

    PubMed Central

    Ivanov, Delyan P.; Grabowska, Anna M.

    2017-01-01

    We describe and share a device, methodology and image analysis algorithms, which allow up to 66 spheroids to be arranged into a gel-based array directly from a culture plate for downstream processing and analysis. Compared to processing individual samples, the technique uses 11-fold less reagents, saves time and enables automated imaging. To illustrate the power of the technology, we showcase applications of the methodology for investigating 3D spheroid morphology and marker expression and for in vitro safety and efficacy screens. First, spheroid arrays of 11 cell-lines were rapidly assessed for differences in spheroid morphology. Second, highly-positive (SOX-2), moderately-positive (Ki-67) and weakly-positive (βIII-tubulin) protein targets were detected and quantified. Third, the arrays enabled screening of ten media compositions for inducing differentiation in human neurospheres. Last, the application of spheroid microarrays for spheroid-based drug screens was demonstrated by quantifying the dose-dependent drop in proliferation and increase in differentiation in etoposide-treated neurospheres. PMID:28134245

  16. [3D-TOF MR-angiography with high spatial resolution for surgical planning in insular lobe gliomas].

    PubMed

    Bykanov, A E; Pitskhelauri, D I; Pronin, I N; Tonoyan, A S; Kornienko, V N; Zakharova, N E; Turkin, A M; Sanikidze, A Z; Shkarubo, M A; Shkatova, A M; Shults, E I

    2015-01-01

    Цель — определение эффективности время-пролетной (3D-TOF) магнитно-резонансной ангиографии (МРА) с высоким разрешением в визуализации медиальных и латеральных лентикулостриарных артерий (ЛСА) и их соотношения с краем опухоли у пациентов с глиомами островковой доли. Материал и методы. Проведен анализ 3D-TOF МРА у 20 пациентов с первично выявленными глиомами головного мозга с вовлечением островковой доли. Всем больным выполнена 3D-TOF МРА без контрастного усиления, а в 6 наблюдениях — до и после него. Результаты. При 3D-TOF МРА до внутривенного контрастирования удавалось определить медиальные ЛСА у 19 (95%) пациентов и латеральные ЛСА — у 18 (90%). 3D-TOF МРА на фоне контрастного усиления позволяет лучше визуализировать как проксимальный, так и дистальный сегмент ЛСА. Выделено три варианта взаимоотношения опухоли и ЛСА: I — опухоль обрастала артерии без их смещения — 2 (10%) случая; II — опухоль смещала артерии медиально без признаков обрастания — 11 (55%); III — опухоль частично обрастала и смещала артерии — 2 (10%). У 5 (25%) пациентов опухоль плохо видна на 3D-TOF МРА из-за отсутствия различий сигнальных хар

  17. Evaluation of Time and Space Scales in a Spatially Developing 3D Turbulent Incompressible Mixing Layer by Using LES

    DTIC Science & Technology

    2001-08-01

    UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP013651 TITLE: Evaluation of Time and Space Scales in a Spatially...the following component part numbers comprise the compilation report: ADP013620 thru ADP013707 UNCLASSIFIED EVALUATION OF TIME AND SPACE SCALES IN A...Simulation (LES). The time and space fluctuations of velocity components lead to the energy spectra. We can then to highlight the characteristic scales in

  18. GPU-Accelerated Forward and Back-Projections with Spatially Varying Kernels for 3D DIRECT TOF PET Reconstruction.

    PubMed

    Ha, S; Matej, S; Ispiryan, M; Mueller, K

    2013-02-01

    We describe a GPU-accelerated framework that efficiently models spatially (shift) variant system response kernels and performs forward- and back-projection operations with these kernels for the DIRECT (Direct Image Reconstruction for TOF) iterative reconstruction approach. Inherent challenges arise from the poor memory cache performance at non-axis aligned TOF directions. Focusing on the GPU memory access patterns, we utilize different kinds of GPU memory according to these patterns in order to maximize the memory cache performance. We also exploit the GPU instruction-level parallelism to efficiently hide long latencies from the memory operations. Our experiments indicate that our GPU implementation of the projection operators has slightly faster or approximately comparable time performance than FFT-based approaches using state-of-the-art FFTW routines. However, most importantly, our GPU framework can also efficiently handle any generic system response kernels, such as spatially symmetric and shift-variant as well as spatially asymmetric and shift-variant, both of which an FFT-based approach cannot cope with.

  19. Temporal-spatial reach parameters derived from inertial sensors: Comparison to 3D marker-based motion capture.

    PubMed

    Cahill-Rowley, Katelyn; Rose, Jessica

    2017-02-08

    Reaching is a well-practiced functional task crucial to daily living activities, and temporal-spatial measures of reaching reflect function for both adult and pediatric populations with upper-extremity motor impairments. Inertial sensors offer a mobile and inexpensive tool for clinical assessment of movement. This research outlines a method for measuring temporal-spatial reach parameters using inertial sensors, and validates these measures with traditional marker-based motion capture. 140 reaches from 10 adults, and 30 reaches from nine children aged 18-20 months, were recorded and analyzed using both inertial-sensor and motion-capture methods. Inertial sensors contained three-axis accelerometers, gyroscopes, and magnetometers. Gravitational offset of accelerometer data was measured when the sensor was at rest, and removed using sensor orientation measured at rest and throughout the reach. Velocity was calculated by numeric integration of acceleration, using a null-velocity assumption at reach start. Sensor drift was neglected given the 1-2s required for a reach. Temporal-spatial reach parameters were calculated independently for each data acquisition method. Reach path length and distance, peak velocity magnitude and timing, and acceleration at contact demonstrated consistent agreement between sensor- and motion-capture-based methods, for both adult and toddler reaches, as evaluated by intraclass correlation coefficients from 0.61 to 1.00. Taken together with actual difference between method measures, results indicate that these functional reach parameters may be reliably measured with inertial sensors.

  20. GPU-Accelerated Forward and Back-Projections with Spatially Varying Kernels for 3D DIRECT TOF PET Reconstruction

    PubMed Central

    Ha, S.; Matej, S.; Ispiryan, M.; Mueller, K.

    2013-01-01

    We describe a GPU-accelerated framework that efficiently models spatially (shift) variant system response kernels and performs forward- and back-projection operations with these kernels for the DIRECT (Direct Image Reconstruction for TOF) iterative reconstruction approach. Inherent challenges arise from the poor memory cache performance at non-axis aligned TOF directions. Focusing on the GPU memory access patterns, we utilize different kinds of GPU memory according to these patterns in order to maximize the memory cache performance. We also exploit the GPU instruction-level parallelism to efficiently hide long latencies from the memory operations. Our experiments indicate that our GPU implementation of the projection operators has slightly faster or approximately comparable time performance than FFT-based approaches using state-of-the-art FFTW routines. However, most importantly, our GPU framework can also efficiently handle any generic system response kernels, such as spatially symmetric and shift-variant as well as spatially asymmetric and shift-variant, both of which an FFT-based approach cannot cope with. PMID:23531763

  1. Resonant structure of the 3d electron`s angular distribution in a free Mn{sup +}Ion

    SciTech Connect

    Amusia, M.Y.; Dolmatov, V.K.

    1995-08-01

    The 3d-electron angular anisotropy parameter of the free Mn{sup +} ion is calculated using the {open_quotes}spin-polarized{close_quotes} random-phase approximation with exchange. Strong resonance structure is discovered, which is due to interference with the powerful 3p {yields} 3d discrete excitation. The effect of the 3p {yields} 4s transition is also noticeable. The ordering of these respective resonances with phonon energy increase proved to be opposite in angular anisotropy parameter to that in 3d-photoionization cross section. A paper describing these results was published.

  2. Spatial Inference for Distributed Remote Sensing Data

    NASA Astrophysics Data System (ADS)

    Braverman, A. J.; Katzfuss, M.; Nguyen, H.

    2014-12-01

    Remote sensing data are inherently spatial, and a substantial portion of their value for scientific analyses derives from the information they can provide about spatially dependent processes. Geophysical variables such as atmopsheric temperature, cloud properties, humidity, aerosols and carbon dioxide all exhibit spatial patterns, and satellite observations can help us learn about the physical mechanisms driving them. However, remote sensing observations are often noisy and incomplete, so inferring properties of true geophysical fields from them requires some care. These data can also be massive, which is both a blessing and a curse: using more data drives uncertainties down, but also drives costs up, particularly when data are stored on different computers or in different physical locations. In this talk I will discuss a methodology for spatial inference on massive, distributed data sets that does not require moving large volumes of data. The idea is based on a combination of ideas including modeling spatial covariance structures with low-rank covariance matrices, and distributed estimation in sensor or wireless networks.

  3. Resonant X-ray scattering measurements of a spatial modulation of the Cu 3d and O 2p energies in stripe-ordered cuprate superconductors.

    PubMed

    Achkar, A J; He, F; Sutarto, R; Geck, J; Zhang, H; Kim, Y-J; Hawthorn, D G

    2013-01-04

    A prevailing description of the stripe phase in underdoped cuprate superconductors is that the charge carriers (holes) phase segregate on a microscopic scale into hole-rich and hole-poor regions. We report resonant elastic x-ray scattering measurements of stripe-ordered La(1.475)Nd(0.4)Sr(0.125)CuO(4) at the Cu L and O K absorption edges that identify an additional feature of stripe order. Analysis of the energy dependence of the scattering intensity reveals that the dominant signature of the stripe order is a spatial modulation in the energies of Cu 3d and O 2p states rather than the large modulation of the charge density (valence) envisioned in the common stripe paradigm. These energy shifts are interpreted as a spatial modulation of the electronic structure and may point to a valence-bond-solid interpretation of the stripe phase.

  4. Effective incorporation of spatial information in a mutual information based 3D-2D registration of a CT volume to X-ray images.

    PubMed

    Zheng, Guoyan

    2008-01-01

    This paper addresses the problem of estimating the 3D rigid pose of a CT volume of an object from its 2D X-ray projections. We use maximization of mutual information, an accurate similarity measure for multi-modal and mono-modal image registration tasks. However, it is known that the standard mutual information measure only takes intensity values into account without considering spatial information and its robustness is questionable. In this paper, instead of directly maximizing mutual information, we propose to use a variational approximation derived from the Kullback-Leibler bound. Spatial information is then incorporated into this variational approximation using a Markov random field model. The newly derived similarity measure has a least-squares form and can be effectively minimized by a multi-resolution Levenberg-Marquardt optimizer. Experimental results are presented on X-ray and CT datasets of a plastic phantom and a cadaveric spine segment.

  5. The use of gel dosimetry to measure the 3D dose distribution of a 90Sr/90Y intravascular brachytherapy seed.

    PubMed

    Massillon-Jl, G; Minniti, R; Mitch, M G; Maryanski, M J; Soares, C G

    2009-03-21

    Absorbed dose distributions in 3D imparted by a single (90)Sr/(90)Y beta particle seed source of the type used for intravascular brachytherapy were investigated. A polymer gel dosimetry medium was used as a dosemeter and phantom, while a special high-resolution laser CT scanner with a spatial resolution of 100 microm in all dimensions was used to quantify the data. We have measured the radial dose function, g(L)(r), observing that g(L)(r) increases to a maximum value and then decreases as the distance from the seed increases. This is in good agreement with previous data obtained with radiochromic film and thermoluminescent dosemeters (TLDs), even if the TLDs underestimate the dose at distances very close to the seed. Contrary to the measurements, g(L)(r) calculated through Monte Carlo simulations and reported previously steadily decreases without a local maximum as a function of the distance from the seed. At distances less than 1.5 mm, differences of more than 20% are observed between the measurements and the Monte Carlo calculations. This difference could be due to a possible underestimation of the energy absorbed into the seed core and encapsulation in the Monte Carlo simulation, as a consequence of the unknown precise chemical composition of the core and its respective density for this seed. The results suggest that g(L)(r) can be measured very close to the seed with a relative uncertainty of about 1% to 2%. The dose distribution is isotropic only at distances greater than or equal to 2 mm from the seed and is almost symmetric, independent of the depth. This study indicates that polymer gel coupled with the special small format laser CT scanner are valid and accurate methods for measuring the dose distribution at distances close to an intravascular brachytherapy seed.

  6. Evolution of a Directional Wave Spectrum in a 3D Marginal Ice Zone with Random Floe Size Distribution

    NASA Astrophysics Data System (ADS)

    Montiel, F.; Squire, V. A.

    2013-12-01

    A new ocean wave/sea-ice interaction model is proposed that simulates how a directional wave spectrum evolves as it travels through a realistic marginal ice zone (MIZ), where wave/ice dynamics are entirely governed by coherent conservative wave scattering effects. Field experiments conducted by Wadhams et al. (1986) in the Greenland Sea generated important data on wave attenuation in the MIZ and, particularly, on whether the wave spectrum spreads directionally or collimates with distance from the ice edge. The data suggest that angular isotropy, arising from multiple scattering by ice floes, occurs close to the edge and thenceforth dominates wave propagation throughout the MIZ. Although several attempts have been made to replicate this finding theoretically, including by the use of numerical models, none have confronted this problem in a 3D MIZ with fully randomised floe distribution properties. We construct such a model by subdividing the discontinuous ice cover into adjacent infinite slabs of finite width parallel to the ice edge. Each slab contains an arbitrary (but finite) number of circular ice floes with randomly distributed properties. Ice floes are modeled as thin elastic plates with uniform thickness and finite draught. We consider a directional wave spectrum with harmonic time dependence incident on the MIZ from the open ocean, defined as a continuous superposition of plane waves traveling at different angles. The scattering problem within each slab is then solved using Graf's interaction theory for an arbitrary incident directional plane wave spectrum. Using an appropriate integral representation of the Hankel function of the first kind (see Cincotti et al., 1993), we map the outgoing circular wave field from each floe on the slab boundaries into a directional spectrum of plane waves, which characterizes the slab reflected and transmitted fields. Discretizing the angular spectrum, we can obtain a scattering matrix for each slab. Standard recursive

  7. 3D-HST + CANDELS: the Evolution of the Galaxy Size-mass Distribution Since Z=3

    NASA Technical Reports Server (NTRS)

    VanDerWel, A.; Franx, M.; vanDokkum, P. G.; Skelton, R. E.; Momcheva, I. G.; Whitaker, K. E.; Brammer, G. B.; Bell, E. F.; Rix, H.-W.; Wuyts, S.; Ferguson, H. C.; Holden, B. P.; Barro, G.; Koekemoer, A. M.; Chang, Yu-Yen; McGrath, E. J.; Haussler, B.; Dekel, A.; Behroozi, P.; Fumagalli, M.; Leja, J.; Lundgren, B. F.; Maseda, M. V.; Nelson, E. J.; Wake, D. A.

    2014-01-01

    Spectroscopic and photometric redshifts, stellar mass estimates, and rest-frame colors from the 3D-HST survey are combined with structural parameter measurements from CANDELS imaging to determine the galaxy size-mass distribution over the redshift (z) range 0 < z < 3. Separating early- and late-type galaxies on the basis of star-formation activity, we confirm that early-type galaxies are on average smaller than late-type galaxies at all redshifts, and find a significantly different rate of average size evolution at fixed galaxy mass, with fast evolution for the early-type population, effective radius is in proportion to (1 + z) (sup -1.48), and moderate evolution for the late-type population, effective radius is in proportion to (1 + z) (sup -0.75). The large sample size and dynamic range in both galaxy mass and redshift, in combination with the high fidelity of our measurements due to the extensive use of spectroscopic data, not only fortify previous results, but also enable us to probe beyond simple average galaxy size measurements. At all redshifts the slope of the size-mass relation is shallow, effective radius in proportion to mass of a black hole (sup 0.22), for late-type galaxies with stellar mass > 3 x 10 (sup 9) solar masses, and steep, effective radius in proportion to mass of a black hole (sup 0.75), for early-type galaxies with stellar mass > 2 x 10 (sup 10) solar masses. The intrinsic scatter is approximately or less than 0.2 decimal exponents for all galaxy types and redshifts. For late-type galaxies, the logarithmic size distribution is not symmetric, but skewed toward small sizes: at all redshifts and masses a tail of small late-type galaxies exists that overlaps in size with the early-type galaxy population. The number density of massive (approximately 10 (sup 11) solar masses), compact (effective radius less than 2 kiloparsecs) early-type galaxies increases from z = 3 to z = 1.5 - 2 and then strongly decreases at later cosmic times.

  8. Flow distributions and spatial correlations in human brain capillary networks

    NASA Astrophysics Data System (ADS)

    Lorthois, Sylvie; Peyrounette, Myriam; Larue, Anne; Le Borgne, Tanguy

    2015-11-01

    The vascular system of the human brain cortex is composed of a space filling mesh-like capillary network connected upstream and downstream to branched quasi-fractal arterioles and venules. The distribution of blood flow rates in these networks may affect the efficiency of oxygen transfer processes. Here, we investigate the distribution and correlation properties of blood flow velocities from numerical simulations in large 3D human intra-cortical vascular network (10000 segments) obtained from an anatomical database. In each segment, flow is solved from a 1D non-linear model taking account of the complex rheological properties of blood flow in microcirculation to deduce blood pressure, blood flow and red blood cell volume fraction distributions throughout the network. The network structural complexity is found to impart broad and spatially correlated Lagrangian velocity distributions, leading to power law transit time distributions. The origins of this behavior (existence of velocity correlations in capillary networks, influence of the coupling with the feeding arterioles and draining veins, topological disorder, complex blood rheology) are studied by comparison with results obtained in various model capillary networks of controlled disorder. ERC BrainMicroFlow GA615102, ERC ReactiveFronts GA648377.

  9. Linear Response Equilibrium versus echo-planar encoding for fast high-spatial resolution 3D chemical shift imaging

    NASA Astrophysics Data System (ADS)

    Fischer, Rudolf Fritz; Baltes, Christof; Weiss, Kilian; Pazhenkottil, Aju; Rudin, Markus; Boesiger, Peter; Kozerke, Sebastian

    2011-07-01

    In this work Linear Response Equilibrium (LRE) and Echo-planar spectroscopic imaging (EPSI) are compared in terms of sensitivity per unit time and power deposition. In addition an extended dual repetition time scheme to generate broad stopbands for improved inherent water suppression in LRE is presented. The feasibility of LRE and EPSI for assessing cholesterol esters in human carotid plaques with high spatial resolution of 1.95 × 1.15 × 1.15 mm 3 on a clinical 3T MR system is demonstrated. In simulations and phantom experiments it is shown that LRE has comparable but lower sensitivity per unit time relative to EPSI despite stronger signal generated. This relates to the lower sampling efficiency in LRE relative to EPSI as a result of limited gradient performance on clinical MR systems. At the same time, power deposition of LRE is significantly reduced compared to EPSI making it an interesting niche application for in vivo high field spectroscopic imaging of metabolites within a limited bandwidth.

  10. spMC: an R-package for 3D lithological reconstructions based on spatial Markov chains

    NASA Astrophysics Data System (ADS)

    Sartore, Luca; Fabbri, Paolo; Gaetan, Carlo

    2016-09-01

    The paper presents the spatial Markov Chains (spMC) R-package and a case study of subsoil simulation/prediction located in a plain site of Northeastern Italy. spMC is a quite complete collection of advanced methods for data inspection, besides spMC implements Markov Chain models to estimate experimental transition probabilities of categorical lithological data. Furthermore, simulation methods based on most known prediction methods (as indicator Kriging and CoKriging) were implemented in spMC package. Moreover, other more advanced methods are available for simulations, e.g. path methods and Bayesian procedures, that exploit the maximum entropy. Since the spMC package was developed for intensive geostatistical computations, part of the code is implemented for parallel computations via the OpenMP constructs. A final analysis of this computational efficiency compares the simulation/prediction algorithms by using different numbers of CPU cores, and considering the example data set of the case study included in the package.

  11. 3-D Spatial Resolution of 350 μm Pitch Pixelated CdZnTe Detectors for Imaging Applications

    PubMed Central

    Yin, Yongzhi; Chen, Ximeng; Wu, Heyu; Komarov, Sergey; Garson, Alfred; Li, Qiang; Guo, Qingzhen; Krawczynski, Henric; Meng, Ling-Jian; Tai, Yuan-Chuan

    2016-01-01

    We are currently investigating the feasibility of using highly pixelated Cadmium Zinc Telluride (CdZnTe) detectors for sub-500 μm resolution PET imaging applications. A 20 mm × 20 mm × 5 mm CdZnTe substrate was fabricated with 350 μm pitch pixels (250 μm anode pixels with 100 μm gap) and coplanar cathode. Charge sharing among the pixels of a 350 μm pitch detector was studied using collimated 122 keV and 511 keV gamma ray sources. For a 350 μm pitch CdZnTe detector, scatter plots of the charge signal of two neighboring pixels clearly show more charge sharing when the collimated beam hits the gap between adjacent pixels. Using collimated Co-57 and Ge-68 sources, we measured the count profiles and estimated the intrinsic spatial resolution of 350 μm pitch detector biased at −1000 V. Depth of interaction was analyzed based on two methods, i.e., cathode/anode ratio and electron drift time, in both 122 keV and 511 keV measurements. For single-pixel photopeak events, a linear correlation between cathode/anode ratio and electron drift time was shown, which would be useful for estimating the DOI information and preserving image resolution in CdZnTe PET imaging applications. PMID:28250476

  12. Spatial Information in Support of 3D Flood Damage Assessment of Buildings at Micro Level: A Review

    NASA Astrophysics Data System (ADS)

    Amirebrahimi, S.; Rajabifard, A.; Sabri, S.; Mendis, P.

    2016-10-01

    Floods, as the most common and costliest natural disaster around the globe, have adverse impacts on buildings which are considered as major contributors to the overall economic damage. With emphasis on risk management methods for reducing the risks to structures and people, estimating damage from potential flood events becomes an important task for identifying and implementing the optimal flood risk-reduction solutions. While traditional Flood Damage Assessment (FDA) methods focus on simple representation of buildings for large-scale damage assessment purposes, recent emphasis on buildings' flood resilience resulted in development of a sophisticated method that allows for a detailed and effective damage evaluation at the scale of building and its components. In pursuit of finding the suitable spatial information model to satisfy the needs of implementing such frameworks, this article explores the technical developments for an effective representation of buildings, floods and other required information within the built environment. The search begins with the Geospatial domain and investigates the state-of-the-art and relevant developments from data point of view in this area. It is further extended to other relevant disciplines in the Architecture, Engineering and Construction domain (AEC/FM) and finally, even some overlapping areas between these domains are considered and explored.

  13. Studying the spatial distribution of interstellar dust

    NASA Technical Reports Server (NTRS)

    Walker, Helen J.; Werner, Michael W.; Allen, C.; Henry, R. C.; Kimble, R.; Wofford, J.; Murthy, Jayant

    1989-01-01

    The spacial distribution of interstellar dust reflects both interstellar dynamics and the processes which form and destroy dust in the interstellar medium (ISM). The IRAS survey, because of its high sensitivity to thermal emission from dust in the IR, provides new approaches to determining the spatial distribution of dust. The initial results are reported of an attempt to use the IRAS data to probe the spatial distribution of dust - by searching for thermal emission from dust in the vicinity of bright stars. These results show that this technique (which relies on finding IR emission associated with randomly selected stars) can ultimately be used to study the distribution of dust in the ISM. The density of the cloud producing the IR emission may be derived by assuming that the dust is at its projected distance from the star and that the heating is due to the star's (known) radiation field. The heating radiation is folded into a grain model, and the number of emitting grains adjusted to reproduce the observed energy distribution. It is noted that this technique is capable in principle of detecting dust densities much lower than those typical of the cirrus clouds.

  14. 3D spatially encoded and accelerated TE-averaged echo planar spectroscopic imaging in healthy human brain.

    PubMed

    Iqbal, Zohaib; Wilson, Neil E; Thomas, M Albert

    2016-03-01

    Several different pathologies, including many neurodegenerative disorders, affect the energy metabolism of the brain. Glutamate, a neurotransmitter in the brain, can be used as a biomarker to monitor these metabolic processes. One method that is capable of quantifying glutamate concentration reliably in several regions of the brain is TE-averaged (1) H spectroscopic imaging. However, this type of method requires the acquisition of multiple TE lines, resulting in long scan durations. The goal of this experiment was to use non-uniform sampling, compressed sensing reconstruction and an echo planar readout gradient to reduce the scan time by a factor of eight to acquire TE-averaged spectra in three spatial dimensions. Simulation of glutamate and glutamine showed that the 2.2-2.4 ppm spectral region contained 95% glutamate signal using the TE-averaged method. Peak integration of this spectral range and home-developed, prior-knowledge-based fitting were used for quantitation. Gray matter brain phantom measurements were acquired on a Siemens 3 T Trio scanner. Non-uniform sampling was applied retrospectively to these phantom measurements and quantitative results of glutamate with respect to creatine 3.0 (Glu/Cr) ratios showed a coefficient of variance of 16% for peak integration and 9% for peak fitting using eight-fold acceleration. In vivo scans of the human brain were acquired as well and five different brain regions were quantified using the prior-knowledge-based algorithm. Glu/Cr ratios from these regions agreed with previously reported results in the literature. The method described here, called accelerated TE-averaged echo planar spectroscopic imaging (TEA-EPSI), is a significant methodological advancement and may be a useful tool for categorizing glutamate changes in pathologies where affected brain regions are not known a priori. Copyright © 2016 John Wiley & Sons, Ltd.

  15. 3D bone mineral density distribution and shape reconstruction of the proximal femur from a single simulated DXA image: an in vitro study

    NASA Astrophysics Data System (ADS)

    Whitmarsh, Tristan; Humbert, Ludovic; De Craene, Mathieu; del Río Barquero, Luis M.; Fritscher, Karl; Schubert, Rainer; Eckstein, Felix; Link, Thomas; Frangi, Alejandro F.

    2010-03-01

    Area Bone Mineral Density (aBMD) measured by Dual-energy X-ray Absorptiometry (DXA) is an established criterion in the evaluation of hip fracture risk. The evaluation from these planar images, however, is limited to 2D while it has been shown that proper 3D assessment of both the shape and the Bone Mineral Density (BMD) distribution improves the fracture risk estimation. In this work we present a method to reconstruct both the 3D bone shape and 3D BMD distribution of the proximal femur from a single DXA image. A statistical model of shape and a separate statistical model of the BMD distribution were automatically constructed from a set of Quantitative Computed Tomography (QCT) scans. The reconstruction method incorporates a fully automatic intensity based 3D-2D registration process, maximizing the similarity between the DXA and a digitally reconstructed radiograph of the combined model. For the construction of the models, an in vitro dataset of QCT scans of 60 anatomical specimens was used. To evaluate the reconstruction accuracy, experiments were performed on simulated DXA images from the QCT scans of 30 anatomical specimens. Comparisons between the reconstructions and the same subject QCT scans showed a mean shape accuracy of 1.2mm, and a mean density error of 81mg/cm3. The results show that this method is capable of accurately reconstructing both the 3D shape and 3D BMD distribution of the proximal femur from DXA images used in clinical routine, potentially improving the diagnosis of osteoporosis and fracture risk assessments at a low radiation dose and low cost.

  16. The CU 2-D-MAX-DOAS instrument - Part 1: Retrieval of 3-D distributions of NO2 and azimuth-dependent OVOC ratios

    NASA Astrophysics Data System (ADS)

    Ortega, I.; Koenig, T.; Sinreich, R.; Thomson, D.; Volkamer, R.

    2015-06-01

    We present an innovative instrument telescope and describe a retrieval method to probe three-dimensional (3-D) distributions of atmospheric trace gases that are relevant to air pollution and tropospheric chemistry. The University of Colorado (CU) two-dimensional (2-D) multi-axis differential optical absorption spectroscopy (CU 2-D-MAX-DOAS) instrument measures nitrogen dioxide (NO2), formaldehyde (HCHO), glyoxal (CHOCHO), oxygen dimer (O2-O2, or O4), and water vapor (H2O); nitrous acid (HONO), bromine monoxide (BrO), and iodine monoxide (IO) are among other gases that can in principle be measured. Information about aerosols is derived through coupling with a radiative transfer model (RTM). The 2-D telescope has three modes of operation: mode 1 measures solar scattered photons from any pair of elevation angle (-20° < EA < +90° or zenith; zero is to the horizon) and azimuth angle (-180° < AA < +180°; zero being north); mode 2 measures any set of azimuth angles (AAs) at constant elevation angle (EA) (almucantar scans); and mode 3 tracks the direct solar beam via a separate view port. Vertical profiles of trace gases are measured and used to estimate mixing layer height (MLH). Horizontal distributions are then derived using MLH and parameterization of RTM (Sinreich et al., 2013). NO2 is evaluated at different wavelengths (350, 450, and 560 nm), exploiting the fact that the effective path length varies systematically with wavelength. The area probed is constrained by O4 observations at nearby wavelengths and has a diurnal mean effective radius of 7.0 to 25 km around the instrument location; i.e., up to 1960 km2 can be sampled with high time resolution. The instrument was deployed as part of the Multi-Axis DOAS Comparison campaign for Aerosols and Trace gases (MAD-CAT) in Mainz, Germany, from 7 June to 6 July 2013. We present first measurements (modes 1 and 2 only) and describe a four-step retrieval to derive (a) boundary layer vertical profiles and MLH of NO2; (b

  17. Invariant joint distribution of a stationary random field and its derivatives: Euler characteristic and critical point counts in 2 and 3D

    SciTech Connect

    Pogosyan, Dmitry; Gay, Christophe; Pichon, Christophe

    2009-10-15

    The full moments expansion of the joint probability distribution of an isotropic random field, its gradient, and invariants of the Hessian are presented in 2 and 3D. It allows for explicit expression for the Euler characteristic in ND and computation of extrema counts as functions of the excursion set threshold and the spectral parameter, as illustrated on model examples.

  18. The Distributed Lambda (?) Model (DLM): A 3-D, Finite-Element Muscle Model Based on Feldman's ? Model; Assessment of Orofacial Gestures

    ERIC Educational Resources Information Center

    Nazari, Mohammad Ali; Perrier, Pascal; Payan, Yohan

    2013-01-01

    Purpose: The authors aimed to design a distributed lambda model (DLM), which is well adapted to implement three-dimensional (3-D), finite-element descriptions of muscles. Method: A muscle element model was designed. Its stress-strain relationships included the active force-length characteristics of the ? model along the muscle fibers, together…

  19. A Distributed Fiber Optic Sensor Network for Online 3-D Temperature and Neutron Fluence Mapping in a VHTR Environment

    SciTech Connect

    Tsvetkov, Pavel; Dickerson, Bryan; French, Joseph; McEachern, Donald; Ougouag, Abderrafi

    2014-04-30

    Robust sensing technologies allowing for 3D in-core performance monitoring in real time are of paramount importance for already established LWRs to enhance their reliability and availability per year, and therefore, to further facilitate their economic competitiveness via predictive assessment of the in-core conditions.

  20. The effect of spatial micro-CT image resolution and surface complexity on the morphological 3D analysis of open porous structures

    SciTech Connect

    Pyka, Grzegorz; Kerckhofs, Greet

    2014-01-15

    In material science microfocus X-ray computed tomography (micro-CT) is one of the most popular non-destructive techniques to visualise and quantify the internal structure of materials in 3D. Despite constant system improvements, state-of-the-art micro-CT images can still hold several artefacts typical for X-ray CT imaging that hinder further image-based processing, structural and quantitative analysis. For example spatial resolution is crucial for an appropriate characterisation as the voxel size essentially influences the partial volume effect. However, defining the adequate image resolution is not a trivial aspect and understanding the correlation between scan parameters like voxel size and the structural properties is crucial for comprehensive material characterisation using micro-CT. Therefore, the objective of this study was to evaluate the influence of the spatial image resolution on the micro-CT based morphological analysis of three-dimensional (3D) open porous structures with a high surface complexity. In particular the correlation between the local surface properties and the accuracy of the micro-CT-based macro-morphology of 3D open porous Ti6Al4V structures produced by selective laser melting (SLM) was targeted and revealed for rough surfaces a strong dependence of the resulting structure characteristics on the scan resolution. Reducing the surface complexity by chemical etching decreased the sensitivity of the overall morphological analysis to the spatial image resolution and increased the detection limit. This study showed that scan settings and image processing parameters need to be customized to the material properties, morphological parameters under investigation and the desired final characteristics (in relation to the intended functional use). Customization of the scan resolution can increase the reliability of the micro-CT based analysis and at the same time reduce its operating costs. - Highlights: • We examine influence of the image resolution

  1. TU-F-17A-04: Respiratory Phase-Resolved 3D MRI with Isotropic High Spatial Resolution: Determination of the Average Breathing Motion Pattern for Abdominal Radiotherapy Planning

    SciTech Connect

    Deng, Z; Pang, J; Yang, W; Yue, Y; Tuli, R; Fraass, B; Li, D; Fan, Z

    2014-06-15

    Purpose: To develop a retrospective 4D-MRI technique (respiratory phase-resolved 3D-MRI) for providing an accurate assessment of tumor motion secondary to respiration. Methods: A 3D projection reconstruction (PR) sequence with self-gating (SG) was developed for 4D-MRI on a 3.0T MRI scanner. The respiration-induced shift of the imaging target was recorded by SG signals acquired in the superior-inferior direction every 15 radial projections (i.e. temporal resolution 98 ms). A total of 73000 radial projections obtained in 8-min were retrospectively sorted into 10 time-domain evenly distributed respiratory phases based on the SG information. Ten 3D image sets were then reconstructed offline. The technique was validated on a motion phantom (gadolinium-doped water-filled box, frequency of 10 and 18 cycles/min) and humans (4 healthy and 2 patients with liver tumors). Imaging protocol included 8-min 4D-MRI followed by 1-min 2D-realtime (498 ms/frame) MRI as a reference. Results: The multiphase 3D image sets with isotropic high spatial resolution (1.56 mm) permits flexible image reformatting and visualization. No intra-phase motion-induced blurring was observed. Comparing to 2D-realtime, 4D-MRI yielded similar motion range (phantom: 10.46 vs. 11.27 mm; healthy subject: 25.20 vs. 17.9 mm; patient: 11.38 vs. 9.30 mm), reasonable displacement difference averaged over the 10 phases (0.74mm; 3.63mm; 1.65mm), and excellent cross-correlation (0.98; 0.96; 0.94) between the two displacement series. Conclusion: Our preliminary study has demonstrated that the 4D-MRI technique can provide high-quality respiratory phase-resolved 3D images that feature: a) isotropic high spatial resolution, b) a fixed scan time of 8 minutes, c) an accurate estimate of average motion pattern, and d) minimal intra-phase motion artifact. This approach has the potential to become a viable alternative solution to assess the impact of breathing on tumor motion and determine appropriate treatment margins

  2. Revised spatially distributed global livestock emissions

    NASA Astrophysics Data System (ADS)

    Asrar, G.; Wolf, J.; West, T. O.

    2015-12-01

    Livestock play an important role in agricultural carbon cycling through consumption of biomass and emissions of methane. Quantification and spatial distribution of methane and carbon dioxide produced by livestock is needed to develop bottom-up estimates for carbon monitoring. These estimates serve as stand-alone international emissions estimates, as input to global emissions modeling, and as comparisons or constraints to flux estimates from atmospheric inversion models. Recent results for the US suggest that the 2006 IPCC default coefficients may underestimate livestock methane emissions. In this project, revised coefficients were calculated for cattle and swine in all global regions, based on reported changes in body mass, quality and quantity of feed, milk production, and management of living animals and manure for these regions. New estimates of livestock methane and carbon dioxide emissions were calculated using the revised coefficients and global livestock population data. Spatial distribution of population data and associated fluxes was conducted using the MODIS Land Cover Type 5, version 5.1 (i.e. MCD12Q1 data product), and a previously published downscaling algorithm for reconciling inventory and satellite-based land cover data at 0.05 degree resolution. Preliminary results for 2013 indicate greater emissions than those calculated using the IPCC 2006 coefficients. Global total enteric fermentation methane increased by 6%, while manure management methane increased by 38%, with variation among species and regions resulting in improved spatial distributions of livestock emissions. These new estimates of total livestock methane are comparable to other recently reported studies for the entire US and the State of California. These new regional/global estimates will improve the ability to reconcile top-down and bottom-up estimates of methane production as well as provide updated global estimates for use in development and evaluation of Earth system models.

  3. On the spatial distribution of fingerprint singularities.

    PubMed

    Cappelli, Raffaele; Maltoni, Davide

    2009-04-01

    Fingerprint singularities play an important role in several fingerprint recognition and classification systems. Although some general relationships and constraints about the location of singularities in the different fingerprint classes are well known, to the best of our knowledge no statistical models have been developed until now. This paper studies the spatial distributions of singularity locations in nature and derives, from a representative dataset of labelled samples, the probability density functions of the four main fingerprint classes. The results obtained can be directly exploited to improve the accuracy of many techniques relying on the position of singularities, as confirmed by the results of two experiments on fingerprint classification and synthesis.

  4. Vertical stratification in arthropod spatial distribution research.

    PubMed

    Marler, Thomas E

    2013-11-01

    Spatial heterogeneity within individual host trees is often overlooked in surveys of phytophagous arthropod abundance and distribution. The armored scale Aulacaspis yasumatsui is controlled by the predator Rhyzobius lophanthae to a greater degree on leaves at 75-cm height than on leaves at ground level within its host tree Cycas micronesica. The direct influence of elevation on the predator indirectly generates vertical heterogeneity of the scale insect. Arthropod sampling schemes that fail to include all strata within the vertical profile of the host tree species may generate misleading outcomes. Results indicate that sub-meter increments can reveal significant differences in vertical distribution of phytophagous insects, and that inclusion of observations on other organisms that interact with the target arthropod may illuminate determinants of vertical heterogeneity.

  5. Global magnetosphere-like 3D structure formation in kinetics by hot magnetized plasma flow characterized by shape of the particle distribution function

    NASA Astrophysics Data System (ADS)

    Gubchenko, Vladimir

    The task was to provide an analytical elementary magnetosphere-like model in kinetics for verification of the 3D EM PIC codes created for space/aerospace and HED plasmas applications. Kinetic approach versus cold MHD approach takes into account different behavior in the EM fields of resonant and non resonant particles in the velocity phase space, which appears via shape characteristics of the particle velocity distribution function (PVDF) and via the spatial dispersion effect forming the collisionless dissipation in the EM fields. The external flow is a hot collisionless plasma characterized by the particle velocity distribution function (PVDF) with different shapes: Maxwellian, kappa, etc. The flow is in a “hot regime”: it can be supersonic but its velocity remains less the thermal velocity of the electrons. The “internal” part of the magnetosphere formed by trapped particles is the prescribed 3D stationary magnetization considered as a spherical “quasiparticle” with internal magnetodipole and toroidal moments represented as a broadband EM driver. We obtain after the linearization of Vlasov/Maxwell equations a self-consistent 3D large scale kinetic solution of the classic problem. Namely, we: model the “outer” part of the magnetosphere formed by external hot plasma flow of the flyby particles. Solution of the Vlasov equation expressed via a tensor of dielectric permittivity of nonmagnetized and magnetized flowing plasma. Here, we obtain the direct kinetic dissipative effect of the magnetotail formation and the opposite diamagnetic effect of the magnetosphere “dipolization”. We get MHD wave cone in flow magnetized by external guiding magnetic (GM) field. Magnetosphere in our consideration is a 3D dissipative “wave” package structure of the skinned EM fields formed by the “waves” excited at frequency bands where we obtain negative values and singularities (resonances) of squared EM refractive index of the cold plasma. The hot regime

  6. Spatial distribution of precipitation extremes in Norway

    NASA Astrophysics Data System (ADS)

    Verpe Dyrrdal, Anita; Skaugen, Thomas; Lenkoski, Alex; Thorarinsdottir, Thordis; Stordal, Frode; Førland, Eirik J.

    2015-04-01

    Estimates of extreme precipitation, in terms of return levels, are crucial in planning and design of important infrastructure. Through two separate studies, we have examined the levels and spatial distribution of daily extreme precipitation over catchments in Norway, and hourly extreme precipitation in a point. The analyses were carried out through the development of two new methods for estimating extreme precipitation in Norway. For daily precipitation we fit the Generalized Extreme Value (GEV) distribution to areal time series from a gridded dataset, consisting of daily precipitation during the period 1957-today with a resolution of 1x1 km². This grid-based method is more objective and less manual and time-consuming compared to the existing method at MET Norway. In addition, estimates in ungauged catchments are easier to obtain, and the GEV approach includes a measure of uncertainty, which is a requirement in climate studies today. Further, we go into depth on the debated GEV shape parameter, which plays an important role for longer return periods. We show that it varies according to dominating precipitation types, having positive values in the southeast and negative values in the southwest. We also find indications that the degree of orographic enhancement might affect the shape parameter. For hourly precipitation, we estimate return levels on a 1x1 km² grid, by linking GEV distributions with latent Gaussian fields in a Bayesian hierarchical model (BHM). Generalized linear models on the GEV parameters, estimated from observations, are able to incorporate location-specific geographic and meteorological information and thereby accommodate these effects on extreme precipitation. Gaussian fields capture additional unexplained spatial heterogeneity and overcome the sparse grid on which observations are collected, while a Bayesian model averaging component directly assesses model uncertainty. We find that mean summer precipitation, mean summer temperature, latitude

  7. Development of a synthetic tissue engineered 3D printed bioceramic-based bone graft with homogenously distributed osteoblasts and mineralizing bone matrix in vitro.

    PubMed

    Adel-Khattab, Doaa; Giacomini, Francesca; Gildenhaar, Renate; Berger, Georg; Gomes, Cynthia; Linow, Ulf; Hardt, Martin; Peleska, Barbara; Günster, Jens; Stiller, Michael; Houshmand, Alireza; Abdel Ghaffar, Khaled; Gamal, Ahmed; El-Mofty, Mohamed; Knabe, Christine

    2016-11-15

    Over the last decade there have been increasing efforts to develop 3D scaffolds for bone tissue engineering from bioactive ceramics with 3D printing emerging as a promising technology. The overall objective of the present study was to generate a tissue engineered synthetic bone graft with homogenously distributed osteoblasts and mineralizing bone matrix in vitro, thereby mimicking the advantageous properties of autogenous bone grafts and facilitating usage for reconstructing segmental discontinuity defects in vivo. To this end, 3D scaffolds were developed from a silica containing calciumalkaliorthophosphate utilizing first a replica technique namely the Schwartzwalder Somers method (SSM), and second 3D printing, (i.e. rapid prototyping, RP). The mechanical and physical scaffold properties and their potential to facilitate homogenous colonization by osteogenic cells and extracellular bone matrix formation throughout the porous scaffold architecture were examined. To this end, osteoblastic cells were dynamically cultured for 7d on both scaffold types with two different concentrations of 1.5 and 3x10(6) cells/ml. The amount of cells and bone matrix formed and osteogenic marker expression were evaluated using hard tissue histology, immunohistochemical and histomorphometric analysis. 3D printed scaffolds (RPS) exhibited more micropores, greater compressive strength and silica release. RPS seeded with 3x10(6) cells/ml displayed greatest cell and extracellular matrix formation, mineralization and osteocalcin expression. In conclusion, RPS displayed superior mechanical and biological properties and facilitated generating a tissue engineered synthetic bone graft in vitro, which mimics the advantageous properties of autogenous bone grafts, by containing homogenously distributed terminally differentiated osteoblasts and mineralizing bone matrix and therefore is suitable for subsequent in vivo implantation for regenerating segmental discontinuity bone defects.

  8. The Spatial Distribution of Spectroscopically Selected Satellite Galaxies

    NASA Astrophysics Data System (ADS)

    Brainerd, Tereasa G.; Agustsson, Ingolfur

    2015-01-01

    We use a mock redshift survey of the first Millennium Run simulation to investigate the spatial locations of spectroscopically selected satellite galaxies. The host-satellite systems were selected using typical redshift space proximity criteria and, therefore, the satellite sample includes a large number of "interlopers" (i.e., false satellites). Fifty percent of the satellites are located outside the virial radii of their host galaxies and 34% are located more than 500 kpc from their host galaxy. The host galaxies reside in relatively isolated regions of space and have stellar masses that span the range 10.3 < log10[M*/Ms] < 11.5. The 3D locations of the satellites are well-fitted by a combination of a Navarro, Frenk & White (NFW) density profile and a power law. At fixed stellar mass, the NFW scale parameter, rs, for the satellites of red hosts exceeds that for the satellites of blue hosts, and in both cases the dependence of rs on host stellar mass is well-fitted by a power law. For the satellites of red hosts, rs ~ (M*/Ms)0.71, while for satellites of blue hosts rs ~ (M*/Ms)0.48. For hosts with large stellar masses (log10[M*/Ms] > 10.8), the satellites of the red hosts are significantly (4σ) less concentrated than is the halo dark matter, while the satellites of blue hosts are marginally (2σ) more concentrated than is the halo dark matter. We perform model fits to the projected locations of the satellites and find that, with the exception of the satellites of the most massive red hosts, the 2D analysis accurately recovers the values of rs that were found using the 3D analysis. Therefore, even in the limit of a large population of "interlopers" in the satellite sample, the 3D distribution of the satellites can be recovered using 2D information alone. However, since the concentration of the satellite distribution differs from that of the dark matter in the case of high mass host galaxies, this calls into question whether spectroscopically selected satellites

  9. Biomechanical influence of crown-to-implant ratio on stress distribution over internal hexagon short implant: 3-D finite element analysis with statistical test.

    PubMed

    Ramos Verri, Fellippo; Santiago Junior, Joel Ferreira; de Faria Almeida, Daniel Augusto; de Oliveira, Guilherme Bérgamo Brandão; de Souza Batista, Victor Eduardo; Marques Honório, Heitor; Noritomi, Pedro Yoshito; Pellizzer, Eduardo Piza

    2015-01-02

    The study of short implants is relevant to the biomechanics of dental implants, and research on crown increase has implications for the daily clinic. The aim of this study was to analyze the biomechanical interactions of a singular implant-supported prosthesis of different crown heights under vertical and oblique force, using the 3-D finite element method. Six 3-D models were designed with Invesalius 3.0, Rhinoceros 3D 4.0, and Solidworks 2010 software. Each model was constructed with a mandibular segment of bone block, including an implant supporting a screwed metal-ceramic crown. The crown height was set at 10, 12.5, and 15 mm. The applied force was 200 N (axial) and 100 N (oblique). We performed an ANOVA statistical test and Tukey tests; p<0.05 was considered statistically significant. The increase of crown height did not influence the stress distribution on screw prosthetic (p>0.05) under axial load. However, crown heights of 12.5 and 15 mm caused statistically significant damage to the stress distribution of screws and to the cortical bone (p<0.001) under oblique load. High crown to implant (C/I) ratio harmed microstrain distribution on bone tissue under axial and oblique loads (p<0.001). Crown increase was a possible deleterious factor to the screws and to the different regions of bone tissue.

  10. Spatial distribution of disease: three case studies.

    PubMed

    Selvin, S; Shaw, G; Schulman, J; Merrill, D W

    1987-09-01

    Maps transformed so as to have constant density of residential population were used to analyze the spatial distribution of disease in three specific areas. Each area had received recent attention because of suspected environmental pollution. The area adjacent to the Rocky Flats Facility (CO) was examined to identify any association between possible plutonium releases and increases in lung cancer or leukemia incidence. The industrial area of northern Contra Costa County (CA) was studied to explore a relationship between petrochemical industrial emissions and histologic-specific lung cancers. Finally, a suspected increase in the risk of congenital cardiac defects possibly related to pollution of the Santa Clara County (CA) water supply was investigated. No evidence of elevated risk of disease was found to be associated with either the Rocky Flats Facility or the polluted water of Santa Clara County. An increase in lung cancer, found by other investigators in earlier years, was shown to persist in association with industrial emissions in Contra Costa County.

  11. Spatial distribution of disease: three case studies

    SciTech Connect

    Selvin, S.; Shaw, G.; Schulman, J.; Merrill, D.W.

    1987-09-01

    Maps transformed so as to have constant density of residential population were used to analyze the spatial distribution of disease in three specific areas. Each area had received recent attention because of suspected environmental pollution. The area adjacent to the Rocky Flats Facility (CO) was examined to identify any association between possible plutonium releases and increases in lung cancer or leukemia incidence. The industrial area of northern Contra Costa County (CA) was studied to explore a relationship between petrochemical industrial emissions and histologic-specific lung cancers. Finally, a suspected increase in the risk of congenital cardiac defects possibly related to pollution of the Santa Clara County (CA) water supply was investigated. No evidence of elevated risk of disease was found to be associated with either the Rocky Flats Facility or the polluted water of Santa Clara County. An increase in lung cancer, found by other investigators in earlier years, was shown to persist in association with industrial emissions in Contra Costa County.

  12. Method for spatially distributing a population

    DOEpatents

    Bright, Edward A [Knoxville, TN; Bhaduri, Budhendra L [Knoxville, TN; Coleman, Phillip R [Knoxville, TN; Dobson, Jerome E [Lawrence, KS

    2007-07-24

    A process for spatially distributing a population count within a geographically defined area can include the steps of logically correlating land usages apparent from a geographically defined area to geospatial features in the geographically defined area and allocating portions of the population count to regions of the geographically defined area having the land usages, according to the logical correlation. The process can also include weighing the logical correlation for determining the allocation of portions of the population count and storing the allocated portions within a searchable data store. The logically correlating step can include the step of logically correlating time-based land usages to geospatial features of the geographically defined area. The process can also include obtaining a population count for the geographically defined area, organizing the geographically defined area into a plurality of sectors, and verifying the allocated portions according to direct observation.

  13. Optimal design of spatial distribution networks

    NASA Astrophysics Data System (ADS)

    Gastner, Michael T.; Newman, M. E. J.

    2006-07-01

    We consider the problem of constructing facilities such as hospitals, airports, or malls in a country with a nonuniform population density, such that the average distance from a person’s home to the nearest facility is minimized. We review some previous approximate treatments of this problem that indicate that the optimal distribution of facilities should have a density that increases with population density, but does so slower than linearly, as the two-thirds power. We confirm this result numerically for the particular case of the United States with recent population data using two independent methods, one a straightforward regression analysis, the other based on density-dependent map projections. We also consider strategies for linking the facilities to form a spatial network, such as a network of flights between airports, so that the combined cost of maintenance of and travel on the network is minimized. We show specific examples of such optimal networks for the case of the United States.

  14. Tracking earthquake source evolution in 3-D

    NASA Astrophysics Data System (ADS)

    Kennett, B. L. N.; Gorbatov, A.; Spiliopoulos, S.

    2014-08-01

    Starting from the hypocentre, the point of initiation of seismic energy, we seek to estimate the subsequent trajectory of the points of emission of high-frequency energy in 3-D, which we term the `evocentres'. We track these evocentres as a function of time by energy stacking for putative points on a 3-D grid around the hypocentre that is expanded as time progresses, selecting the location of maximum energy release as a function of time. The spatial resolution in the neighbourhood of a target point can be simply estimated by spatial mapping using the properties of isochrons from the stations. The mapping of a seismogram segment to space is by inverse slowness, and thus more distant stations have a broader spatial contribution. As in hypocentral estimation, the inclusion of a wide azimuthal distribution of stations significantly enhances 3-D capability. We illustrate this approach to tracking source evolution in 3-D by considering two major earthquakes, the 2007 Mw 8.1 Solomons islands event that ruptured across a plate boundary and the 2013 Mw 8.3 event 610 km beneath the Sea of Okhotsk. In each case we are able to provide estimates of the evolution of high-frequency energy that tally well with alternative schemes, but also to provide information on the 3-D characteristics that is not available from backprojection from distant networks. We are able to demonstrate that the major characteristics of event rupture can be captured using just a few azimuthally distributed stations, which opens the opportunity for the approach to be used in a rapid mode immediately after a major event to provide guidance for, for example tsunami warning for megathrust events.

  15. Spatial Distribution of Large Cloud Drops

    NASA Technical Reports Server (NTRS)

    Marshak, Alexander; Knyazikhin, Yuri; Larsen, Michael; Wiscombe, Warren

    2004-01-01

    The analysis of aircraft measurements of individual drop sizes in clouds suggests that for sufficiently small volumes the mean number of cloud drops with a given radius is proportional to volume powered by a drop-size dependent exponent. For abundant small drops present, the exponent is 1 as assumed in conventional approach. However, for rarer large drops, the exponents fall below unity. We show striking examples of the spatial distribution of large cloud drops using models that simulate the observed power laws. In contrast to currently used models that assume homogeneity and therefore a Poisson distribution of cloud drops, these models show strong drop clustering, the more so the larger the drops. The degree of clustering is determined by the observed exponents. The strong clustering of large drops arises naturally from the observed power-law statistics. This clustering has vital consequences for rain physics explaining how rain can form so fast and also helps explain why remotely sensed cloud drop size is generally biased.

  16. Spatial Distribution of Large Cloud Drops

    NASA Technical Reports Server (NTRS)

    Marshak, A.; Knyazikhin, Y.; Larsen, M.; Wiscombe, W.

    2004-01-01

    By analyzing aircraft measurements of individual drop sizes in clouds, we have shown in a companion paper (Knyazikhin et al., 2004) that the probability of finding a drop of radius r at a linear scale l decreases as l(sup D(r)) where 0 less than or equal to D(r) less than or equal to 1. This paper shows striking examples of the spatial distribution of large cloud drops using models that simulate the observed power laws. In contrast to currently used models that assume homogeneity and therefore a Poisson distribution of cloud drops, these models show strong drop clustering, the more so the larger the drops. The degree of clustering is determined by the observed exponents D(r). The strong clustering of large drops arises naturally from the observed power-law statistics. This clustering has vital consequences for rain physics explaining how rain can form so fast. It also helps explain why remotely sensed cloud drop size is generally biased and why clouds absorb more sunlight than conventional radiative transfer models predict.

  17. GIS characterization of spatially distributed lifeline damage

    USGS Publications Warehouse

    Toprak, Selcuk; O'Rourke, Thomas; Tutuncu, Ilker

    1999-01-01

    This paper describes the visualization of spatially distributed water pipeline damage following an earthquake using geographical information systems (GIS). Pipeline damage is expressed as a repair rate (RR). Repair rate contours are developed with GIS by dividing the study area into grid cells (n ?? n), determining the number of particular pipeline repairs in each grid cell, and dividing the number of repairs by the length of that pipeline in each cell area. The resulting contour plot is a two-dimensional visualization of point source damage. High damage zones are defined herein as areas with an RR value greater than the mean RR for the entire study area of interest. A hyperbolic relationship between visual display of high pipeline damage zones and grid size, n, was developed. The relationship is expressed in terms of two dimensionless parameters, threshold area coverage (TAC) and dimensionless grid size (DGS). The relationship is valid over a wide range of different map scales spanning approximately 1,200 km2 for the largest portion of the Los Angeles water distribution system to 1 km2 for the Marina in San Francisco. This relationship can aid GIS users to get sufficiently refined, but easily visualized, maps of damage patterns.

  18. Effective incorporating spatial information in a mutual information based 3D-2D registration of a CT volume to X-ray images.

    PubMed

    Zheng, Guoyan

    2010-10-01

    This paper addresses the problem of estimating the 3D rigid poses of a CT volume of an object from its 2D X-ray projection(s). We use maximization of mutual information, an accurate similarity measure for multi-modal and mono-modal image registration tasks. However, it is known that the standard mutual information measures only take intensity values into account without considering spatial information and their robustness is questionable. In this paper, instead of directly maximizing mutual information, we propose to use a variational approximation derived from the Kullback-Leibler bound. Spatial information is then incorporated into this variational approximation using a Markov random field model. The newly derived similarity measure has a least-squares form and can be effectively minimized by a multi-resolution Levenberg-Marquardt optimizer. Experiments were conducted on datasets from two applications: (a) intra-operative patient pose estimation from a limited number (e.g. 2) of calibrated fluoroscopic images, and (b) post-operative cup orientation estimation from a single standard X-ray radiograph with/without gonadal shielding. The experiment on intra-operative patient pose estimation showed a mean target registration accuracy of 0.8mm and a capture range of 11.5mm, while the experiment on estimating the post-operative cup orientation from a single X-ray radiograph showed a mean accuracy below 2 degrees for both anteversion and inclination. More importantly, results from both experiments demonstrated that the newly derived similarity measures were robust to occlusions in the X-ray image(s).

  19. Reconstructing the 3D shape and bone mineral density distribution of the proximal femur from dual-energy X-ray absorptiometry.

    PubMed

    Whitmarsh, Tristan; Humbert, Ludovic; De Craene, Mathieu; Del Rio Barquero, Luis M; Frangi, Alejandro F

    2011-12-01

    The accurate diagnosis of osteoporosis has gained increasing importance due to the aging of our society. Areal bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) is an established criterion in the diagnosis of osteoporosis. This measure, however, is limited by its two-dimensionality. This work presents a method to reconstruct both the 3D bone shape and 3D BMD distribution of the proximal femur from a single DXA image used in clinical routine. A statistical model of the combined shape and BMD distribution is presented, together with a method for its construction from a set of quantitative computed tomography (QCT) scans. A reconstruction is acquired in an intensity based 3D-2D registration process whereby an instance of the model is found that maximizes the similarity between its projection and the DXA image. Reconstruction experiments were performed on the DXA images of 30 subjects, with a model constructed from a database of QCT scans of 85 subjects. The accuracy was evaluated by comparing the reconstructions with the same subject QCT scans. The method presented here can potentially improve the diagnosis of osteoporosis and fracture risk assessment from the low radiation dose and low cost DXA devices currently used in clinical routine.

  20. Use of a 3-D dispersion model for calculation of distribution of horse allergen and odor around horse facilities.

    PubMed

    Haeger-Eugensson, Marie; Ferm, Martin; Elfman, Lena

    2014-03-31

    The interest in equestrian sports has increased substantially during the last decades, resulting in increased number of horse facilities around urban areas. In Sweden, new guidelines for safe distance have been decided based on the size of the horse facility (e.g., number of horses) and local conditions, such as topography and meteorology. There is therefore an increasing need to estimate dispersion of horse allergens to be used, for example, in the planning processes for new residential areas in the vicinity of horse facilities. The aim of this study was to develop a method for calculating short- and long-term emissions and dispersion of horse allergen and odor around horse facilities. First, a method was developed to estimate horse allergen and odor emissions at hourly resolution based on field measurements. Secondly, these emission factors were used to calculate concentrations of horse allergen and odor by using 3-D dispersion modeling. Results from these calculations showed that horse allergens spread up to about 200 m, after which concentration levels were very low (<2 U/m³). Approximately 10% of a study-group detected the smell of manure at 60m, while the majority--80%-90%--detected smell at 60 m or shorter distance from the manure heap. Modeling enabled horse allergen exposure concentrations to be determined with good time resolution.

  1. A 3D simulation of the early winter distribution of reactive chlorine in the north polar vortex

    NASA Technical Reports Server (NTRS)

    Douglass, A.; Rood, R.; Waters, J.; Froidevaux, L.; Read, W.; Elson, L.; Geller, M.; Chi, Y.; Cerniglia, M.; Steenrod, S.

    1993-01-01

    Early in December 1991, high values of ClO are seen by the Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite at latitudes south of areas of temperatures cold enough to form polar stratospheric clouds (PSCs). A 3D simulation shows that the heterogeneous conversion of chlorine reservoirs to reactive chlorine on the surfaces of PSCs (processing) takes place at high latitudes. Often the processed air must be transported to lower latitudes, where the reactive chlorine is photochemically converted to ClO, to be observed by MLS. In this simulation, one incidence of cold temperatures is associated with an anticyclone, and a second with a cyclone. The transport of processed air associated with the anticyclone is marked by shearing; a decrease in the maximum of the processed air is accompanied by growth of the area influenced by the processing. In contrast, the air processed in the cyclonic event spreads more slowly. This shows that transport and shearing is a crucial element to the evolution of reactive chlorine associated with a processing event. In particular, transport and shearing, as well as photochemical processes, can cause variations in observed ClO.

  2. The spatial distribution of Mustelidae in France.

    PubMed

    Calenge, Clément; Chadoeuf, Joël; Giraud, Christophe; Huet, Sylvie; Julliard, Romain; Monestiez, Pascal; Piffady, Jérémy; Pinaud, David; Ruette, Sandrine

    2015-01-01

    We estimated the spatial distribution of 6 Mustelidae species in France using the data collected by the French national hunting and wildlife agency under the "small carnivorous species logbooks" program. The 1500 national wildlife protection officers working for this agency spend 80% of their working time traveling in the spatial area in which they have authority. During their travels, they occasionally detect dead or living small and medium size carnivorous animals. Between 2002 and 2005, each car operated by this agency was equipped with a logbook in which officers recorded information about the detected animals (species, location, dead or alive, date). Thus, more than 30000 dead or living animals were detected during the study period. Because a large number of detected animals in a region could have been the result of a high sampling pressure there, we modeled the number of detected animals as a function of the sampling effort to allow for unbiased estimation of the species density. For dead animals -- mostly roadkill -- we supposed that the effort in a given region was proportional to the distance traveled by the officers. For living animals, we had no way to measure the sampling effort. We demonstrated that it was possible to use the whole dataset (dead and living animals) to estimate the following: (i) the relative density -- i.e., the density multiplied by an unknown constant -- of each species of interest across the different French agricultural regions, (ii) the sampling effort for living animals for each region, and (iii) the relative detection probability for various species of interest.

  3. Longevity of duct tape in residential air distribution systems: 1-D, 2-D, and 3-D joints

    SciTech Connect

    Abushakra, Bass

    2002-05-30

    The aging tests conducted so far showed that duct tape tends to degrade in its performance as the joint it is applied to requires a geometrical description of a higher number of space dimensions (1-D, 2-D, 3-D). One-dimensional joints are the easiest to seal with duct tape, and thus the least to experience failure. Two-dimensional joints, such as the flexible duct core-to-collar joints tested in this study, are less likely to fail than three-dimensional collar-to-plenum joints, as the shrinkage could have a positive effect in tightening the joint. Three-dimensional joints are the toughest to seal and the most likely to experience failure. The 2-D flexible duct core-to-collar joints passed the six-month period of the aging test in terms of leakage, but with the exception of the foil-butyl tape, showed degradation in terms hardening, brittleness, partial peeling, shrinkage, wrinkling, delamination of the tape layers, flaking, cracking, bubbling, oozing and discoloration. The baking test results showed that the failure in the duct tape joints could be attributed to the type of combination of the duct tape and the material it is applied to, as the duct tape behaves differently with different substrates. Overall, the foil-butyl tape (Tape 4) had the best results, while the film tape (Tape 3) showed the most deterioration. The conventional duct tapes tested (Tape 1 and Tape 2) were between these two extremes, with Tape 2 performing better than Tape 1. Lastly, we found that plastic straps became discolored and brittle during the tests, and a couple of straps broke completely. Therefore, we recommend that clamping the duct-taped flexible core-to-collar joints should be done with metallic adjustable straps.

  4. Multizone Paper Platform for 3D Cell Cultures

    PubMed Central

    Derda, Ratmir; Hong, Estrella; Mwangi, Martin; Mammoto, Akiko; Ingber, Donald E.; Whitesides, George M.

    2011-01-01

    In vitro 3D culture is an important model for tissues in vivo. Cells in different locations of 3D tissues are physiologically different, because they are exposed to different concentrations of oxygen, nutrients, and signaling molecules, and to other environmental factors (temperature, mechanical stress, etc). The majority of high-throughput assays based on 3D cultures, however, can only detect the average behavior of cells in the whole 3D construct. Isolation of cells from specific regions of 3D cultures is possible, but relies on low-throughput techniques such as tissue sectioning and micromanipulation. Based on a procedure reported previously (“cells-in-gels-in-paper” or CiGiP), this paper describes a simple method for culture of arrays of thin planar sections of tissues, either alone or stacked to create more complex 3D tissue structures. This procedure starts with sheets of paper patterned with hydrophobic regions that form 96 hydrophilic zones. Serial spotting of cells suspended in extracellular matrix (ECM) gel onto the patterned paper creates an array of 200 micron-thick slabs of ECM gel (supported mechanically by cellulose fibers) containing cells. Stacking the sheets with zones aligned on top of one another assembles 96 3D multilayer constructs. De-stacking the layers of the 3D culture, by peeling apart the sheets of paper, “sections” all 96 cultures at once. It is, thus, simple to isolate 200-micron-thick cell-containing slabs from each 3D culture in the 96-zone array. Because the 3D cultures are assembled from multiple layers, the number of cells plated initially in each layer determines the spatial distribution of cells in the stacked 3D cultures. This capability made it possible to compare the growth of 3D tumor models of different spatial composition, and to examine the migration of cells in these structures. PMID:21573103

  5. Feasibility of using sodium chloride as a tracer for the characterization of the distribution of matter in complex multi-compartment 3D bioreactors for stem cell culture.

    PubMed

    Gerlach, Jörg C; Witaschek, Tom; Strobel, Catrin; Brayfield, Candace A; Bornemann, Reinhard; Catapano, Gerardo; Zeilinger, Katrin

    2010-06-01

    The experimental characterization of the distribution of matter in complex multi-compartment three-dimensional membrane bioreactors for human cell culture is complicated by tracer interactions with the membranes and other bioreactor constituents. This is due to the fact that membranes with a high specific surface area often feature a hydrophobic chemical backbone that may adsorb tracers often used to this purpose, such as proteins and dyes. Membrane selectivity, and its worsening caused by protein adsorption, may also hinder tracer transfer across neighboring compartments, thus preventing effective characterization of the distribution of matter in the whole bioreactor. Tracer experiments with sodium chloride (NaCl) may overcome some of these limitations and be effectively used to characterize the distribution of matter in complex 3D multi-compartments membrane bioreactors for stem cell culture. NaCl freely permeates most used membranes, it does not adsorb on uncharged membranes, and its concentration may be accurately measured in terms of solution conductivity. In this preliminary study, the feasibility of complex multi-compartment membrane bioreactors was investigated with a NaCl concentration pulse challenge to characterize how their distribution of matter changes when they are operated under different conditions. In particular, bioreactors consisting of three different membrane types stacked on top of one another to form a 3D network were characterized under different feed conditions.

  6. [Spatial distribution of macroinvertebrates in Xiangxi River].

    PubMed

    Jiang, Wan-xiang; Cai, Qing-hua; Tang, Tao; Wu, Nai-cheng; Fu, Xiao-cheng; Li, Feng-qing; Liu, Rui-qiu

    2008-11-01

    An investigation was made from July 2005 to June 2006 to understand the spatial distribution of macroinvertebrates in Xiangxi River, the largest tributary in Hubei portion of Three Gorges Reservoir. The results showed that Ephemeroptera baetis spp., Ephemeroptera epeorus spp., and Plecoptera nemoura spp. were the dominant taxa. There existed greater differences in the habitat characters and in the community structure of macroinvertebrates among the major tributaries of Xiangxi River, and the relative abundance of functional feeding groups could reflect the characters of different habitats. A comparison of the diversity of dominant taxa and their tolerance towards pollution among the major tributaries showed that Jiuchong River had the best habitat, followed by the main stream of Xiangxi River, and Gaolan River and Gufu River. Canonical correspondence analysis showed that the NH4+ -N concentration in the main stream of Xiangxi River, the pH, turbidity, water depth, SiO2, conductance, and alkalinity in Jiuchong River, the turbidity in Gaolan River, and the NH4+ -N and NO3- -N concentrations in Gufu River had significant impact on the community structure of macroinvertebrates.

  7. Characterizing spatial variability in velocity and turbulence intensity using 3-D acoustic Doppler velocimeter data in a plane-bed reach of East St. Louis Creek, Colorado, USA

    NASA Astrophysics Data System (ADS)

    David, Gabrielle C. L.; Legleiter, Carl J.; Wohl, Ellen; Yochum, Steven E.

    2013-02-01

    We investigated the influence on flow resistance of flow structure and turbulence at the reach scale in a mountain channel using 3-D velocity measurements and geostatistical analysis to understand the complexity of the flow structure in a reach with limited bed irregularities. The increase in flow resistance at low flows in a plane-bed reach was not fully explained by grain resistance, therefore detailed 3-D velocity measurements were made to investigate spatial variability in velocity and turbulence components and potential controls on flow resistance. One plane-bed reach was surveyed over two stages in Fraser Experimental Forest, Colorado, using a combination of a total station, LiDAR (Light Detection and Ranging), and a SonTek Flowtracker handheld ADV (acoustic Doppler velocimeter). LiDAR was used to capture bank and channel geometry at low flows, whereas the water surface and bed data were collected with the total station at all flows. We used the standard deviation of bed elevation (σb) within a moving window as an index of roughness height (ks) and calculated the relative submergence of the bed at different stages as h/ks, where h is the local flow depth. ADV measurements were collected on a grid with a 0.3 m to 0.5 m spacing. Geostatistical analysis of the velocity data indicated that the flow was highly three-dimensional and varied based on stage, demonstrating that even small irregularities in the bed have a significant influence on the flow characteristics. The streamwise component was the largest at both low and high flow, but varied more throughout the reach at low flow. At high flow, the greatest streamwise velocities were located within the thalweg. Areas of upwelling and downwelling also varied based on stage, with this component being strongly influenced by small changes in the morphology at high flow, and by protuberant grains at low flows. The cross-stream velocity and turbulence components were controlled by the flow structure and less by the

  8. 3D ELECTRON DENSITY DISTRIBUTIONS IN THE SOLAR CORONA DURING SOLAR MINIMA: ASSESSMENT FOR MORE REALISTIC SOLAR WIND MODELING

    SciTech Connect

    Patoul, Judith de; Foullon, Claire; Riley, Pete E-mail: c.foullon@exeter.ac.uk

    2015-11-20

    Knowledge of the electron density distribution in the solar corona put constraints on the magnetic field configurations for coronal modeling and on initial conditions for solar wind modeling. We work with polarized SOHO/LASCO-C2 images from the last two recent minima of solar activity (1996–1997 and 2008–2010), devoid of coronal mass ejections. The goals are to derive the 4D electron density distributions in the corona by applying a newly developed time-dependent tomographic reconstruction method and to compare the results between the two solar minima and with two magnetohydrodynamic models. First, we confirm that the values of the density distribution in thermodynamic models are more realistic than in polytropic ones. The tomography provides more accurate distributions in the polar regions, and we find that the density in tomographic and thermodynamic solutions varies with the solar cycle in both polar and equatorial regions. Second, we find that the highest-density structures do not always correspond to the predicted large-scale heliospheric current sheet or its helmet streamer but can follow the locations of pseudo-streamers. We deduce that tomography offers reliable density distributions in the corona, reproducing the slow time evolution of coronal structures, without prior knowledge of the coronal magnetic field over a full rotation. Finally, we suggest that the highest-density structures show a differential rotation well above the surface depending on how they are magnetically connected to the surface. Such valuable information on the rotation of large-scale structures could help to connect the sources of the solar wind to their in situ counterparts in future missions such as Solar Orbiter and Solar Probe Plus.

  9. Effect of Hydrostatic Pressure on the 3D Porosity Distribution and Mechanical Behavior of a High Pressure Die Cast Mg AZ91 Alloy

    NASA Astrophysics Data System (ADS)

    Sket, Federico; Fernández, Ana; Jérusalem, Antoine; Molina-Aldareguía, Jon M.; Pérez-Prado, María Teresa

    2015-09-01

    A limiting factor of high pressure die cast (HPDC) Mg alloys is the presence of porosity, which has a detrimental effect on the mechanical strength and gives rise to a large variability in the ductility. The application of hydrostatic pressure after casting is known to be beneficial to improve the mechanical response of HPDC Mg alloys. In this study, a combined experimental and simulation approach has been developed in order to investigate the influence of pressurization on the 3D porosity distribution and on the mechanical behavior of an HPDC Mg AZ91 alloy. Examination of about 10,000 pores by X-ray computed microtomography allowed determining the effect of hydrostatic pressure on the bulk porosity volume fraction, as well as the change in volume and geometry of each individual pore. The evolution of the 3D porosity distribution and mechanical behavior of a sub-volume containing 200 pores was also simulated by finite element analysis. Both experiments and simulations consistently revealed a decrease in the bulk porosity fraction and a bimodal distribution of the individual volume changes after the application of the pressure. This observation is associated with pores containing internal pressure as a result of the HPDC process. Furthermore, a decrease in the complexity factor with increasing volume change is observed experimentally and predicted by simulations. The pressure-treated samples have consistently higher plastic flow strengths.

  10. A Smart Cage With Uniform Wireless Power Distribution in 3D for Enabling Long-Term Experiments With Freely Moving Animals.

    PubMed

    Mirbozorgi, S Abdollah; Bahrami, Hadi; Sawan, Mohamad; Gosselin, Benoit

    2016-04-01

    This paper presents a novel experimental chamber with uniform wireless power distribution in 3D for enabling long-term biomedical experiments with small freely moving animal subjects. The implemented power transmission chamber prototype is based on arrays of parallel resonators and multicoil inductive links, to form a novel and highly efficient wireless power transmission system. The power transmitter unit includes several identical resonators enclosed in a scalable array of overlapping square coils which are connected in parallel to provide uniform power distribution along x and y. Moreover, the proposed chamber uses two arrays of primary resonators, facing each other, and connected in parallel to achieve uniform power distribution along the z axis. Each surface includes 9 overlapped coils connected in parallel and implemented into two layers of FR4 printed circuit board. The chamber features a natural power localization mechanism, which simplifies its implementation and ease its operation by avoiding the need for active detection and control mechanisms. A single power surface based on the proposed approach can provide a power transfer efficiency (PTE) of 69% and a power delivered to the load (PDL) of 120 mW, for a separation distance of 4 cm, whereas the complete chamber prototype provides a uniform PTE of 59% and a PDL of 100 mW in 3D, everywhere inside the chamber with a size of 27×27×16 cm(3).

  11. Simulation of phytoplankton distribution and variation in the Bering-Chukchi Sea using a 3-D physical-biological model

    NASA Astrophysics Data System (ADS)

    Hu, Haoguo; Wang, Jia; Liu, Hui; Goes, Joaquim

    2016-06-01

    A three-dimensional physical-biological model has been used to simulate seasonal phytoplankton variations in the Bering and Chukchi Seas with a focus on understanding the physical and biogeochemical mechanisms involved in the formation of the Bering Sea Green Belt (GB) and the Subsurface Chlorophyll Maxima (SCM). Model results suggest that the horizontal distribution of the GB is controlled by a combination of light, temperature, and nutrients. Model results indicated that the SCM, frequently seen below the thermocline, exists because of a rich supply of nutrients and sufficient light. The seasonal onset of phytoplankton blooms is controlled by different factors at different locations in the Bering-Chukchi Sea. In the off-shelf central region of the Bering Sea, phytoplankton blooms are regulated by available light. On the Bering Sea shelf, sea ice through its influence on light and temperature plays a key role in the formation of blooms, whereas in the Chukchi Sea, bloom formation is largely controlled by ambient seawater temperatures. A numerical experiment conducted as part of this study revealed that plankton sinking is important for simulating the vertical distribution of phytoplankton and the seasonal formation of the SCM. An additional numerical experiment revealed that sea ice algae account for 14.3-36.9% of total phytoplankton production during the melting season, and it cannot be ignored when evaluating primary productivity in the Arctic Ocean.

  12. Spatial distribution of pingos in Northern Asia

    USGS Publications Warehouse

    Grosse, G.; Jones, Benjamin M.

    2010-01-01

    Pingos are prominent periglacial landforms in vast regions of the Arctic and Subarctic. They are indicators of modern and past conditions of permafrost, surface geology, hydrology and climate. A first version of a detailed spatial geodatabase of more than 6000 pingo locations in a 3.5 ?? 106 km2 region of Northern Asia was assembled from topographic maps. A first order analysis was carried out with respect to permafrost, landscape characteristics, surface geology, hydrology, climate, and elevation datasets using a Geographic Information System (GIS). Pingo heights in the dataset vary between 2 and 37 m, with a mean height of 4.8 m. About 64% of the pingos occur in continuous permafrost with high ice content and thick sediments; another 19% in continuous permafrost with moderate ice content and thick sediments. The majority of these pingos likely formed through closed system freezing, typical of those located in drained thermokarst lake basins of northern lowlands with continuous permafrost. About 82% of the pingos are located in the tundra bioclimatic zone. Most pingos in the dataset are located in regions with mean annual ground temperatures between -3 and -11 ??C and mean annual air temperatures between -7 and -18 ??C. The dataset confirms that surface geology and hydrology are key factors for pingo formation and occurrence. Based on model predictions for near-future permafrost distribution, hundreds of pingos along the southern margins of permafrost will be located in regions with thawing permafrost by 2100, which ultimately may lead to increased occurrence of pingo collapse. Based on our dataset and previously published estimates of pingo numbers from other regions, we conclude that there are more than 11 000 pingos on Earth. ?? 2010 Author(s).

  13. Spatial distribution of pingos in Northern Asia

    NASA Astrophysics Data System (ADS)

    Grosse, G.; Jones, B. M.

    2010-09-01

    Pingos are prominent periglacial landforms in vast regions of the Arctic and Subarctic. They are indicators of modern and past conditions of permafrost, surface geology, hydrology and climate. A first version of a detailed spatial geodatabase of more than 6000 pingo locations in a 3.5 × 106 km2 region of Northern Asia was assembled from topographic maps. A first order analysis was carried out with respect to permafrost, landscape characteristics, surface geology, hydrology, climate, and elevation datasets using a Geographic Information System (GIS). Pingo heights in the dataset vary between 2 and 37 m, with a mean height of 4.8 m. About 64% of the pingos occur in continuous permafrost with high ice content and thick sediments; another 19% in continuous permafrost with moderate ice content and thick sediments. The majority of these pingos likely formed through closed system freezing, typical of those located in drained thermokarst lake basins of northern lowlands with continuous permafrost. About 82% of the pingos are located in the tundra bioclimatic zone. Most pingos in the dataset are located in regions with mean annual ground temperatures between -3 and -11 °C and mean annual air temperatures between -7 and -18 °C. The dataset confirms that surface geology and hydrology are key factors for pingo formation and occurrence. Based on model predictions for near-future permafrost distribution, hundreds of pingos along the southern margins of permafrost will be located in regions with thawing permafrost by 2100, which ultimately may lead to increased occurrence of pingo collapse. Based on our dataset and previously published estimates of pingo numbers from other regions, we conclude that there are more than 11 000 pingos on Earth.

  14. Spatial distribution of pingos in northern Asia

    NASA Astrophysics Data System (ADS)

    Grosse, G.; Jones, B. M.

    2011-01-01

    Pingos are prominent periglacial landforms in vast regions of the Arctic and Subarctic. They are indicators of modern and past conditions of permafrost, surface geology, hydrology and climate. A first version of a detailed spatial geodatabase of 6059 pingo locations in a 3.5×106 km2 region of northern Asia was assembled from topographic maps. A first order analysis was carried out with respect to permafrost, landscape characteristics, surface geology, hydrology, climate, and elevation datasets using a Geographic Information System (GIS). Pingo heights in the dataset vary between 2 and 37 m, with a mean height of 4.8 m. About 64% of the pingos occur in continuous permafrost with high ice content and thick sediments; another 19% in continuous permafrost with moderate ice content and thick sediments. The majority of these pingos are likely hydrostatic pingos, which are typical of those located in drained thermokarst lake basins of northern lowlands with continuous permafrost. About 82% of the pingos are located in the tundra bioclimatic zone. Most pingos in the dataset are located in regions with mean annual ground temperatures between -3 and -11 °C and mean annual air temperatures between -7 and -18 °C. The dataset confirms that surface geology and hydrology are key factors for pingo formation and occurrence. Based on model predictions for near-future permafrost distribution, about 2073 pingos (34%) along the southern margins of permafrost will be located in regions with thawing permafrost by 2100, which ultimately may lead to increased occurrence of pingo collapse. Based on our dataset and previously published estimates of pingo numbers from other regions, we conclude that there are more than 11 000 pingos on Earth.

  15. SPECT Imaging of 2-D and 3-D Distributed Sources with Near-Field Coded Aperture Collimation: Computer Simulation and Real Data Validation.

    PubMed

    Mu, Zhiping; Dobrucki, Lawrence W; Liu, Yi-Hwa

    The imaging of distributed sources with near-field coded aperture (CA) remains extremely challenging and is broadly considered unsuitable for single-photon emission computerized tomography (SPECT). This study proposes a novel CA SPECT reconstruction approach and evaluates the feasibilities of imaging and reconstructing distributed hot sources and cold lesions using near-field CA collimation and iterative image reconstruction. Computer simulations were designed to compare CA and pinhole collimations in two-dimensional radionuclide imaging. Digital phantoms were created and CA images of the phantoms were reconstructed using maximum likelihood expectation maximization (MLEM). Errors and the contrast-to-noise ratio (CNR) were calculated and image resolution was evaluated. An ex vivo rat heart with myocardial infarction was imaged using a micro-SPECT system equipped with a custom-made CA module and a commercial 5-pinhole collimator. Rat CA images were reconstructed via the three-dimensional (3-D) MLEM algorithm developed for CA SPECT with and without correction for a large projection angle, and 5-pinhole images were reconstructed using the commercial software provided by the SPECT system. Phantom images of CA were markedly improved in terms of image quality, quantitative root-mean-squared error, and CNR, as compared to pinhole images. CA and pinhole images yielded similar image resolution, while CA collimation resulted in fewer noise artifacts. CA and pinhole images of the rat heart were well reconstructed and the myocardial perfusion defects could be clearly discerned from 3-D CA and 5-pinhole SPECT images, whereas 5-pinhole SPECT images suffered from severe noise artifacts. Image contrast of CA SPECT was further improved after correction for the large projection angle used in the rat heart imaging. The computer simulations and small-animal imaging study presented herein indicate that the proposed 3-D CA SPECT imaging and reconstruction approaches worked reasonably

  16. Euro3D Science Conference

    NASA Astrophysics Data System (ADS)

    Walsh, J. R.

    2004-02-01

    The Euro3D RTN is an EU funded Research Training Network to foster the exploitation of 3D spectroscopy in Europe. 3D spectroscopy is a general term for spectroscopy of an area of the sky and derives its name from its two spatial + one spectral dimensions. There are an increasing number of instruments which use integral field devices to achieve spectroscopy of an area of the sky, either using lens arrays, optical fibres or image slicers, to pack spectra of multiple pixels on the sky (``spaxels'') onto a 2D detector. On account of the large volume of data and the special methods required to reduce and analyse 3D data, there are only a few centres of expertise and these are mostly involved with instrument developments. There is a perceived lack of expertise in 3D spectroscopy spread though the astronomical community and its use in the armoury of the observational astronomer is viewed as being highly specialised. For precisely this reason the Euro3D RTN was proposed to train young researchers in this area and develop user tools to widen the experience with this particular type of data in Europe. The Euro3D RTN is coordinated by Martin M. Roth (Astrophysikalisches Institut Potsdam) and has been running since July 2002. The first Euro3D science conference was held in Cambridge, UK from 22 to 23 May 2003. The main emphasis of the conference was, in keeping with the RTN, to expose the work of the young post-docs who are funded by the RTN. In addition the team members from the eleven European institutes involved in Euro3D also presented instrumental and observational developments. The conference was organized by Andy Bunker and held at the Institute of Astronomy. There were over thirty participants and 26 talks covered the whole range of application of 3D techniques. The science ranged from Galactic planetary nebulae and globular clusters to kinematics of nearby galaxies out to objects at high redshift. Several talks were devoted to reporting recent observations with newly

  17. Time-Dependent Distribution Functions in C-Mod Calculated with the CQL3D-Hybrid-FOW, AORSA Full-Wave, and DC Lorentz Codes

    NASA Astrophysics Data System (ADS)

    Harvey, R. W. (Bob); Petrov, Yu. V.; Jaeger, E. F.; Berry, L. A.; Bonoli, P. T.; Bader, A.

    2015-11-01

    A time-dependent simulation of C-Mod pulsed ICRF power is made calculating minority hydrogen ion distribution functions with the CQL3D-Hybrid-FOW finite-orbit-width Fokker-Planck code. ICRF fields are calculated with the AORSA full wave code, and RF diffusion coefficients are obtained from these fields using the DC Lorentz gyro-orbit code. Prior results with a zero-banana-width simulation using the CQL3D/AORSA/DC time-cycles showed a pronounced enhancement of the H distribution in the perpendicular velocity direction compared to results obtained from Stix's quasilinear theory, in general agreement with experiment. The present study compares the new FOW results, including relevant gyro-radius effects, to determine the importance of these effects on the the NPA synthetic diagnostic time-dependence. The new NPA results give increased agreement with experiment, particularly in the ramp-down time after the ICRF pulse. Funded, through subcontract with Massachusetts Institute of Technology, by USDOE sponsored SciDAC Center for Simulation of Wave-Plasma Interactions.

  18. Europeana and 3D

    NASA Astrophysics Data System (ADS)

    Pletinckx, D.

    2011-09-01

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

  19. Impact of implant diameter and length on stress distribution in osseointegrated implants: A 3D FEA study

    PubMed Central

    Eazhil, R.; Swaminathan, Siva Vadivel; Gunaseelan, Madhan; Kannan, G. Vijay; Alagesan, Chandrapandian

    2016-01-01

    Aims and Objectives: Dimension of dental implant is an important parameter which has a considerable impact on the biomechanical load transfer characters and its prognosis. Excessive stress in the bone–implant interface may result in the failure of the implant. The aim of this study was to evaluate the impact of implant diameter and length on neighboring tissues around the implant. The results of the study will help in developing a scientific methodology to select appropriate implant diameter and length. Materials and Methods: In this study, tapered implants of different diameter and length were numerically analyzed using bone–implant models developed from computed tomography generated images of mandible with osseointegrated implants. The impact of various diameters on stress distribution was examined using implants with a length of 13 mm and diameters of 3.5 mm, 4.3 mm and 5.0 mm. Implants with a diameter of 4.3 mm and lengths of 10 mm, 13 mm, 16 mm was developed to examine the impact of various implant length. All materials were assumed to be linearly elastic and isotropic. Masticatory load was applied in a natural direction, oblique to the occlusal plane. The Statistical Package for the Social Sciences software package was used for statistical analysis. Results: Maximum von Mises stresses were located around the implant neck. It was demonstrated that there was statistically significant decrease in von Mises stress as the implant diameter increased. Conclusion: Within the limitations of this study there was statistically significant decrease in von Mises stress as the implant diameter increased. PMID:28032053

  20. Stress distribution in cylindrical and conical implants under rotational micromovement with different boundary conditions and bone properties: 3-D FEA.

    PubMed

    Dos Santos, Mateus Bertolini Fernandes; Meloto, Gabriel de Oliveira; Bacchi, Ataís; Correr-Sobrinho, Lourenço

    2017-03-28

    Factors related to micromovements at bone-implant interface have been studied because they are considered adverse to osseointegration. Simplifications are commonly observed in these FEA evaluations. The aim of this study was to clarify the influence of FEA parameters (boundary conditions and bone properties) on the stress distribution in peri-implant bone tissue when micromovements are simulated in implants with different geometries. Three-dimensional models of an anterior section of the jaw with cylindrical or conical titanium implants (4.1 mm in width and 11 mm in length) were created. Micromovement (50, 150, or 250 μm) was applied to the implant. The FEA parameters studied were linear vs. non-linear analyses, isotropic vs. orthogonal anisotropic bone, friction coefficient (0.3) vs. frictionless bone-implant contact. Data from von Mises, shear, maximum, and minimum principal stresses in the peri-implant bone tissue were compared. Linear analyses presented a relevant increase of the stress values, regardless of the bone properties. Frictionless contact reduced the stress values in non-linear analysis. Isotropic bone presented lower stress than orthogonal anisotropic. Conical implants behave better, in regard to compressive stresses (minimum principal), than cylindrical ones, except for nonlinear analyses when micromovement of 150 and 250 μm were simulated. The stress values raised as the micromovement amplitude increased. Non-linear analysis, presence of frictional contact and orthogonal anisotropic bone, evaluated through maximum and minimum principal stress should be used as FEA parameters for implant-micromovement studies.

  1. Imaging 3D strain field monitoring during hydraulic fracturing processes

    NASA Astrophysics Data System (ADS)

    Chen, Rongzhang; Zaghloul, Mohamed A. S.; Yan, Aidong; Li, Shuo; Lu, Guanyi; Ames, Brandon C.; Zolfaghari, Navid; Bunger, Andrew P.; Li, Ming-Jun; Chen, Kevin P.

    2016-05-01

    In this paper, we present a distributed fiber optic sensing scheme to study 3D strain fields inside concrete cubes during hydraulic fracturing process. Optical fibers embedded in concrete were used to monitor 3D strain field build-up with external hydraulic pressures. High spatial resolution strain fields were interrogated by the in-fiber Rayleigh backscattering with 1-cm spatial resolution using optical frequency domain reflectometry. The fiber optics sensor scheme presented in this paper provides scientists and engineers a unique laboratory tool to understand the hydraulic fracturing processes in various rock formations and its impacts to environments.

  2. Fast Gated EPR Imaging of the Beating Heart: Spatiotemporally-Resolved 3D Imaging of Free Radical Distribution during the Cardiac Cycle

    PubMed Central

    Chen, Zhiyu; Reyes, Levy A.; Johnson, David H.; Velayutham, Murugesan; Yang, Changjun; Samouilov, Alexandre; Zweier, Jay L.

    2012-01-01

    In vivo or ex vivo electron paramagnetic resonance imaging (EPRI) is a powerful technique for determining the spatial distribution of free radicals and other paramagnetic species in living organs and tissues. However, applications of EPRI have been limited by long projection acquisition times and the consequent fact that rapid gated EPRI was not possible. Hence in vivo EPRI typically provided only time-averaged information. In order to achieve direct gated EPRI, a fast EPR acquisition scheme was developed to decrease EPR projection acquisition time down to 10 – 20 ms, along with corresponding software and instrumentation to achieve fast gated EPRI of the isolated beating heart with submillimeter spatial resolution in as little as 2 to 3 minutes. Reconstructed images display temporal and spatial variations of the free radical distribution, anatomical structure, and contractile function within the rat heart during the cardiac cycle. PMID:22473660

  3. [Thoughts on the spatial distribution of population].

    PubMed

    Borisovna, L; Velez, F

    1991-12-01

    city in all age groups, especially in the 15-19 cohort. A large proportion of the migrants were more highly educated than the average city dweller. The average rate of growth of the working age population in the city was 6% from 1970-80, implying a need for 35,000 new jobs annually. But in 1980-90, only 10,000 new jobs were added each year. The relative importance of tertiary sector employment has increased significantly. A review of the population characteristics and spatial distribution of the city and state of Puebla strongly suggests that decentralization should be vigorously pursued as a means of improving the wellbeing of the population.

  4. Design, calibration and validation of a novel 3D printed instrumented spatial linkage that measures changes in the rotational axes of the tibiofemoral joint.

    PubMed

    Bonny, Daniel P; Hull, M L; Howell, S M

    2014-01-01

    An accurate axis-finding technique is required to measure any changes from normal caused by total knee arthroplasty in the flexion-extension (F-E) and longitudinal rotation (LR) axes of the tibiofemoral joint. In a previous paper, we computationally determined how best to design and use an instrumented spatial linkage (ISL) to locate the F-E and LR axes such that rotational and translational errors were minimized. However, the ISL was not built and consequently was not calibrated; thus the errors in locating these axes were not quantified on an actual ISL. Moreover, previous methods to calibrate an ISL used calibration devices with accuracies that were either undocumented or insufficient for the device to serve as a gold-standard. Accordingly, the objectives were to (1) construct an ISL using the previously established guidelines,(2) calibrate the ISL using an improved method, and (3) quantify the error in measuring changes in the F-E and LR axes. A 3D printed ISL was constructed and calibrated using a coordinate measuring machine, which served as a gold standard. Validation was performed using a fixture that represented the tibiofemoral joint with an adjustable F-E axis and the errors in measuring changes to the positions and orientations of the F-E and LR axes were quantified. The resulting root mean squared errors (RMSEs) of the calibration residuals using the new calibration method were 0.24, 0.33, and 0.15 mm for the anterior-posterior, medial-lateral, and proximal-distal positions, respectively, and 0.11, 0.10, and 0.09 deg for varus-valgus, flexion-extension, and internal-external orientations, respectively. All RMSEs were below 0.29% of the respective full-scale range. When measuring changes to the F-E or LR axes, each orientation error was below 0.5 deg; when measuring changes in the F-E axis, each position error was below 1.0 mm. The largest position RMSE was when measuring a medial-lateral change in the LR axis (1.2 mm). Despite the large size

  5. New image processing software for analyzing object size-frequency distributions, geometry, orientation, and spatial distribution

    NASA Astrophysics Data System (ADS)

    Beggan, Ciarán; Hamilton, Christopher W.

    2010-04-01

    Geological Image Analysis Software (GIAS) combines basic tools for calculating object area, abundance, radius, perimeter, eccentricity, orientation, and centroid location, with the first automated method for characterizing the aerial distribution of objects using sample-size-dependent nearest neighbor (NN) statistics. The NN analyses include tests for (1) Poisson, (2) Normalized Poisson, (3) Scavenged k=1, and (4) Scavenged k=2 NN distributions. GIAS is implemented in MATLAB with a Graphical User Interface (GUI) that is available as pre-parsed pseudocode for use with MATLAB, or as a stand-alone application that runs on Windows and Unix systems. GIAS can process raster data (e.g., satellite imagery, photomicrographs, etc.) and tables of object coordinates to characterize the size, geometry, orientation, and spatial organization of a wide range of geological features. This information expedites quantitative measurements of 2D object properties, provides criteria for validating the use of stereology to transform 2D object sections into 3D models, and establishes a standardized NN methodology that can be used to compare the results of different geospatial studies and identify objects using non-morphological parameters.

  6. 3D differential phase contrast microscopy

    PubMed Central

    Chen, Michael; Tian, Lei; Waller, Laura

    2016-01-01

    We demonstrate 3D phase and absorption recovery from partially coherent intensity images captured with a programmable LED array source. Images are captured through-focus with four different illumination patterns. Using first Born and weak object approximations (WOA), a linear 3D differential phase contrast (DPC) model is derived. The partially coherent transfer functions relate the sample’s complex refractive index distribution to intensity measurements at varying defocus. Volumetric reconstruction is achieved by a global FFT-based method, without an intermediate 2D phase retrieval step. Because the illumination is spatially partially coherent, the transverse resolution of the reconstructed field achieves twice the NA of coherent systems and improved axial resolution. PMID:27867705

  7. A computerized framework for monitoring four-dimensional dose distributions during stereotactic body radiation therapy using a portal dose image-based 2D/3D registration approach.

    PubMed

    Nakamoto, Takahiro; Arimura, Hidetaka; Nakamura, Katsumasa; Shioyama, Yoshiyuki; Mizoguchi, Asumi; Hirose, Taka-Aki; Honda, Hiroshi; Umezu, Yoshiyuki; Nakamura, Yasuhiko; Hirata, Hideki

    2015-03-01

    A computerized framework for monitoring four-dimensional (4D) dose distributions during stereotactic body radiation therapy based on a portal dose image (PDI)-based 2D/3D registration approach has been proposed in this study. Using the PDI-based registration approach, simulated 4D "treatment" CT images were derived from the deformation of 3D planning CT images so that a 2D planning PDI could be similar to a 2D dynamic clinical PDI at a breathing phase. The planning PDI was calculated by applying a dose calculation algorithm (a pencil beam convolution algorithm) to the geometry of the planning CT image and a virtual water equivalent phantom. The dynamic clinical PDIs were estimated from electronic portal imaging device (EPID) dynamic images including breathing phase data obtained during a treatment. The parameters of the affine transformation matrix were optimized based on an objective function and a gamma pass rate using a Levenberg-Marquardt (LM) algorithm. The proposed framework was applied to the EPID dynamic images of ten lung cancer patients, which included 183 frames (mean: 18.3 per patient). The 4D dose distributions during the treatment time were successfully obtained by applying the dose calculation algorithm to the simulated 4D "treatment" CT images. The mean±standard deviation (SD) of the percentage errors between the prescribed dose and the estimated dose at an isocenter for all cases was 3.25±4.43%. The maximum error for the ten cases was 14.67% (prescribed dose: 1.50Gy, estimated dose: 1.72Gy), and the minimum error was 0.00%. The proposed framework could be feasible for monitoring the 4D dose distribution and dose errors within a patient's body during treatment.

  8. Characterization of fracture reservoirs using static and dynamic data: From sonic and 3D seismic to permeability distribution. Annual report, March 1, 1996--February 28, 1997

    SciTech Connect

    Parra, J.O.; Collier, H.A.; Owen, T.E.

    1997-06-01

    In low porosity, low permeability zones, natural fractures are the primary source of permeability which affect both production and injection of fluids. The open fractures do not contribute much to porosity, but they provide an increased drainage network to any porosity. They also may connect the borehole to remote zones of better reservoir characteristics. An important approach to characterizing the fracture orientation and fracture permeability of reservoir formations is one based on the effects of such conditions on the propagation of acoustic and seismic waves in the rock. The project is a study directed toward the evaluation of acoustic logging and 3D-seismic measurement techniques as well as fluid flow and transport methods for mapping permeability anisotropy and other petrophysical parameters for the understanding of the reservoir fracture systems and associated fluid dynamics. The principal application of these measurement techniques and methods is to identify and investigate the propagation characteristics of acoustic and seismic waves in the Twin Creek hydrocarbon reservoir owned by Union Pacific Resources (UPR) and to characterize the fracture permeability distribution using production data. This site is located in the overthrust area of Utah and Wyoming. UPR drilled six horizontal wells, and presently UPR has two rigs running with many established drill hole locations. In addition, there are numerous vertical wells that exist in the area as well as 3D seismic surveys. Each horizontal well contains full FMS logs and MWD logs, gamma logs, etc.

  9. 3d-3d correspondence revisited

    DOE PAGES

    Chung, Hee -Joong; Dimofte, Tudor; Gukov, Sergei; ...

    2016-04-21

    In fivebrane compactifications on 3-manifolds, we point out the importance of all flat connections in the proper definition of the effective 3d N = 2 theory. The Lagrangians of some theories with the desired properties can be constructed with the help of homological knot invariants that categorify colored Jones polynomials. Higgsing the full 3d theories constructed this way recovers theories found previously by Dimofte-Gaiotto-Gukov. As a result, we also consider the cutting and gluing of 3-manifolds along smooth boundaries and the role played by all flat connections in this operation.

  10. Relationship Between the 3D Porosity and β-Phase Distributions and the Mechanical Properties of a High Pressure Die Cast AZ91 Mg Alloy

    NASA Astrophysics Data System (ADS)

    Biswas, Somjeet; Sket, Federico; Chiumenti, Michele; Gutiérrez-Urrutia, Iván; Molina-Aldareguía, Jon M.; Pérez-Prado, Maria Teresa

    2013-09-01

    Currently, most magnesium lightweight components are fabricated by casting as this process is cost effective and allows forming parts with complex geometries and weak textures. However, cast microstructures are known to be heterogeneous and contain unpredictable porosity distributions, which give rise to a large variability in the mechanical properties. This work constitutes an attempt to correlate the microstructure and the mechanical behavior of a high pressure die cast (HPDC) Mg AZ91 alloy, aimed at facilitating process optimization. We have built a stairway-shaped die to fabricate alloy sections with different thicknesses and, thus, with a range of microstructures. The grain size distributions and the content of β-phase (Mg17Al12) were characterized by optical and electron microscopy techniques as well as by electron backscatter diffraction (EBSD). The bulk porosity distribution was measured by 3D computed X-ray microtomography. It was found that the through-thickness microhardness distribution is mostly related to the local area fraction of the β-phase and to the local area fraction of the pores. We correlate the tensile yield strength to the average pore size and the fracture strength and elongation to the bulk porosity volume fraction. We propose that this empirical approach might be extended to the estimation of mechanical properties in other HPDC Mg alloys.

  11. Background and Pickup Ion Velocity Distribution Dynamics in Titan's Plasma Environment: 3D Hybrid Simulation and Comparison with CAPS T9 Observations

    NASA Technical Reports Server (NTRS)

    Lipatov, A. S.; Sittler, E. C., Jr.; Hartle, R. E.; Cooper, J. F.; Simpson, D. G.

    2011-01-01

    In this report we discuss the ion velocity distribution dynamics from the 3D hybrid simulation. In our model the background, pickup, and ionospheric ions are considered as a particles, whereas the electrons are described as a fluid. Inhomogeneous photoionization, electron-impact ionization and charge exchange are included in our model. We also take into account the collisions between the ions and neutrals. The current simulation shows that mass loading by pickup ions H(+); H2(+), CH4(+) and N2(+) is stronger than in the previous simulations when O+ ions are introduced into the background plasma. In our hybrid simulations we use Chamberlain profiles for the atmospheric components. We also include a simple ionosphere model with average mass M = 28 amu ions that were generated inside the ionosphere. The moon is considered as a weakly conducting body. Special attention will be paid to comparing the simulated pickup ion velocity distribution with CAPS T9 observations. Our simulation shows an asymmetry of the ion density distribution and the magnetic field, including the formation of the Alfve n wing-like structures. The simulation also shows that the ring-like velocity distribution for pickup ions relaxes to a Maxwellian core and a shell-like halo.

  12. Dynamics of pickup ion velocity distribution function in Titan's plasma environment (TA encounter): 3D hybrid kinetic modeling and comparison with CAPS observations

    NASA Astrophysics Data System (ADS)

    Simpson, D. G.; Lipatov, A. S.; Sittler, E. C.; Hartle, R. E.; Cooper, J. F.

    2013-12-01

    Wave-particle interactions play a very important role in the plasma dynamics near Titan: mass loading, excitation of the low-frequency waves and the formation of the particle velocity distribution function, e.g. ring/shell-like distributions, etc. The kinetic approach is important for estimation of the collision processes e.g. a charge exchange. The particle velocity distribution function also plays a key role for understanding the observed particle fluxes. In this report we discuss the ion velocity distribution function dynamics from 3D hybrid modeling. The modeling is based on recent analysis of the Cassini Plasma Spectrometer (CAPS) ion measurements during the TA flyby. In our model the background ions, all pickup ions, and ionospheric ions are considered as particles, whereas the electrons are described as a fluid. Inhomogeneous photoionization, electron-impact ionization and charge exchange are included in our model. The temperatures of the background electrons and pickup electrons were also included into the generalized Ohm's law. We also take into account the collisions between the ions and neutrals. We use Chamberlain profiles for the exosphere's components and include a simple ionosphere model with M=28 ions that were generated inside the ionosphere. The moon is considered as a weakly conducting body. Our modeling shows that interaction between background plasma and pickup ions H+, H2+, CH4+ and N2+ has a more complicated structure than was observed in the T9 flyby and modeling due to the large gyroradius of the background O+ ions [1,2,3,4]. Special attention will be paid to comparing the simulated pickup ion velocity distribution with CAPS TA observations. We also compare our kinetic modeling with other hybrid and MHD modeling of Titan's environment. References [1] Sittler, E.C., et al., Energy Deposition Processes in Titan's Upper Atmosphere and Its Induced Magnetosphere. In: Titan from Cassini-Huygens, Brown, R.H., Lebreton J.P., Waite, J.H., Eds

  13. PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITHOUT TURB3D)

    NASA Technical Reports Server (NTRS)

    Buning, P.

    1994-01-01

    Apollo's 3-dimensional graphics hardware, but does not take advantage of the shading and hidden line/surface removal capabilities of the Apollo DN10000. Although this implementation does not offer a capability for putting text on plots, it does support the use of a mouse to translate, rotate, or zoom in on views. The version 3.6b+ Apollo implementations of PLOT3D (ARC-12789) and PLOT3D/TURB3D (ARC-12785) were developed for use on Apollo computers running UNIX System V with BSD 4.3 extensions and the graphics library GMR3D Version 2.0. The standard distribution media for each of these programs is a 9-track, 6250 bpi magnetic tape in TAR format. Customers purchasing one implementation version of PLOT3D or PLOT3D/TURB3D will be given a $200 discount on each additional implementation version ordered at the same time. Version 3.6b+ of PLOT3D and PLOT3D/TURB3D are also supported for the following computers and graphics libraries: 1) generic UNIX Supercomputer and IRIS, suitable for CRAY 2/UNICOS, CONVEX, and Alliant with remote IRIS 2xxx/3xxx or IRIS 4D (ARC-12779, ARC-12784); 2) VAX computers running VMS Version 5.0 and DISSPLA Version 11.0 (ARC-12777, ARC-12781); 3) generic UNIX and DISSPLA Version 11.0 (ARC-12788, ARC-12778); and (4) Silicon Graphics IRIS 2xxx/3xxx or IRIS 4D workstations (ARC-12783, ARC-12782). Silicon Graphics Iris, IRIS 4D, and IRIS 2xxx/3xxx are trademarks of Silicon Graphics Incorporated. VAX and VMS are trademarks of Digital Electronics Corporation. DISSPLA is a trademark of Computer Associates. CRAY 2 and UNICOS are trademarks of CRAY Research, Incorporated. CONVEX is a trademark of Convex Computer Corporation. Alliant is a trademark of Alliant. Apollo and GMR3D are trademarks of Hewlett-Packard, Incorporated. UNIX is a registered trademark of AT&T.

  14. PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITH TURB3D)

    NASA Technical Reports Server (NTRS)

    Buning, P.

    1994-01-01

    Apollo's 3-dimensional graphics hardware, but does not take advantage of the shading and hidden line/surface removal capabilities of the Apollo DN10000. Although this implementation does not offer a capability for putting text on plots, it does support the use of a mouse to translate, rotate, or zoom in on views. The version 3.6b+ Apollo implementations of PLOT3D (ARC-12789) and PLOT3D/TURB3D (ARC-12785) were developed for use on Apollo computers running UNIX System V with BSD 4.3 extensions and the graphics library GMR3D Version 2.0. The standard distribution media for each of these programs is a 9-track, 6250 bpi magnetic tape in TAR format. Customers purchasing one implementation version of PLOT3D or PLOT3D/TURB3D will be given a $200 discount on each additional implementation version ordered at the same time. Version 3.6b+ of PLOT3D and PLOT3D/TURB3D are also supported for the following computers and graphics libraries: 1) generic UNIX Supercomputer and IRIS, suitable for CRAY 2/UNICOS, CONVEX, and Alliant with remote IRIS 2xxx/3xxx or IRIS 4D (ARC-12779, ARC-12784); 2) VAX computers running VMS Version 5.0 and DISSPLA Version 11.0 (ARC-12777, ARC-12781); 3) generic UNIX and DISSPLA Version 11.0 (ARC-12788, ARC-12778); and (4) Silicon Graphics IRIS 2xxx/3xxx or IRIS 4D workstations (ARC-12783, ARC-12782). Silicon Graphics Iris, IRIS 4D, and IRIS 2xxx/3xxx are trademarks of Silicon Graphics Incorporated. VAX and VMS are trademarks of Digital Electronics Corporation. DISSPLA is a trademark of Computer Associates. CRAY 2 and UNICOS are trademarks of CRAY Research, Incorporated. CONVEX is a trademark of Convex Computer Corporation. Alliant is a trademark of Alliant. Apollo and GMR3D are trademarks of Hewlett-Packard, Incorporated. UNIX is a registered trademark of AT&T.

  15. Use of a graphics processing unit (GPU) to facilitate real-time 3D graphic presentation of the patient skin-dose distribution during fluoroscopic interventional procedures

    NASA Astrophysics Data System (ADS)

    Rana, Vijay; Rudin, Stephen; Bednarek, Daniel R.

    2012-03-01

    We have developed a dose-tracking system (DTS) that calculates the radiation dose to the patient's skin in realtime by acquiring exposure parameters and imaging-system-geometry from the digital bus on a Toshiba Infinix C-arm unit. The cumulative dose values are then displayed as a color map on an OpenGL-based 3D graphic of the patient for immediate feedback to the interventionalist. Determination of those elements on the surface of the patient 3D-graphic that intersect the beam and calculation of the dose for these elements in real time demands fast computation. Reducing the size of the elements results in more computation load on the computer processor and therefore a tradeoff occurs between the resolution of the patient graphic and the real-time performance of the DTS. The speed of the DTS for calculating dose to the skin is limited by the central processing unit (CPU) and can be improved by using the parallel processing power of a graphics processing unit (GPU). Here, we compare the performance speed of GPU-based DTS software to that of the current CPU-based software as a function of the resolution of the patient graphics. Results show a tremendous improvement in speed using the GPU. While an increase in the spatial resolution of the patient graphics resulted in slowing down the computational speed of the DTS on the CPU, the speed of the GPU-based DTS was hardly affected. This GPU-based DTS can be a powerful tool for providing accurate, real-time feedback about patient skin-dose to physicians while performing interventional procedures.

  16. Use of a graphics processing unit (GPU) to facilitate real-time 3D graphic presentation of the patient skin-dose distribution during fluoroscopic interventional procedures.

    PubMed

    Rana, Vijay; Rudin, Stephen; Bednarek, Daniel R

    2012-02-23

    We have developed a dose-tracking system (DTS) that calculates the radiation dose to the patient's skin in real-time by acquiring exposure parameters and imaging-system-geometry from the digital bus on a Toshiba Infinix C-arm unit. The cumulative dose values are then displayed as a color map on an OpenGL-based 3D graphic of the patient for immediate feedback to the interventionalist. Determination of those elements on the surface of the patient 3D-graphic that intersect the beam and calculation of the dose for these elements in real time demands fast computation. Reducing the size of the elements results in more computation load on the computer processor and therefore a tradeoff occurs between the resolution of the patient graphic and the real-time performance of the DTS. The speed of the DTS for calculating dose to the skin is limited by the central processing unit (CPU) and can be improved by using the parallel processing power of a graphics processing unit (GPU). Here, we compare the performance speed of GPU-based DTS software to that of the current CPU-based software as a function of the resolution of the patient graphics. Results show a tremendous improvement in speed using the GPU. While an increase in the spatial resolution of the patient graphics resulted in slowing down the computational speed of the DTS on the CPU, the speed of the GPU-based DTS was hardly affected. This GPU-based DTS can be a powerful tool for providing accurate, real-time feedback about patient skin-dose to physicians while performing interventional procedures.

  17. Classification of lung nodules in diagnostic CT: an approach based on 3D vascular features, nodule density distribution, and shape features

    NASA Astrophysics Data System (ADS)

    Lo, Shih-Chung B.; Hsu, Li-Yueh; Freedman, Matthew T.; Lure, Yuan Ming F.; Zhao, Hui

    2003-05-01

    We have developed various segmentation and analysis methods for the quantification of lung nodules in thoracic CT. Our methods include the enhancement of lung structures followed by a series of segmentation methods to extract the nodule and to form 3D configuration at an area of interest. The vascular index, aspect ratio, circularity, irregularity, extent, compactness, and convexity were also computed as shape features for quantifying the nodule boundary. The density distribution of the nodule was modeled based on its internal homogeneity and/or heterogeneity. We also used several density related features including entropy, difference entropy as well as other first and second order moments. We have collected 48 cases of lung nodules scanned by thin-slice diagnostic CT. Of these cases, 24 are benign and 24 are malignant. A jackknife experiment was performed using a standard back-propagation neural network as the classifier. The LABROC result showed that the Az of this preliminary study is 0.89.

  18. Solar Wind Halo Formation by the Scattering of the Strahl via Direct Cluster/PEACE Observations of the 3D Velocity Distribution Function

    NASA Technical Reports Server (NTRS)

    Figueroa-Vinas, Adolfo; Gurgiolo, Chris A.; Nieves-Chinchilla, Teresa; Goldstein, Melvyn L.

    2010-01-01

    It has been suggested by a number of authors that the solar wind electron halo can be formed by the scattering of the strahl. On frequent occasions we have observed in electron angular skymaps (Phi/Theta-plots) of the electron 3D velocity distribution functions) a bursty-filament of particles connecting the strahl to the solar wind core-halo. These are seen over a very limited energy range. When the magnetic field is well off the nominal solar wind flow direction such filaments are inconsistent with any local forces and are probably the result of strong scattering. Furthermore, observations indicates that the strahl component is frequently and significantly anisotropic (Tper/Tpal approx.2). This provides a possible free energy source for the excitation of whistler waves as a possible scattering mechanism. The empirical observational evidence between the halo and the strahl suggests that the strahl population may be, at least in part, the source of the halo component.

  19. CROSS DRIVE: A New Interactive and Immersive Approach for Exploring 3D Time-Dependent Mars Atmospheric Data in Distributed Teams

    NASA Astrophysics Data System (ADS)

    Gerndt, Andreas M.; Engelke, Wito; Giuranna, Marco; Vandaele, Ann C.; Neary, Lori; Aoki, Shohei; Kasaba, Yasumasa; Garcia, Arturo; Fernando, Terrence; Roberts, David; CROSS DRIVE Team

    2016-10-01

    Atmospheric phenomena of Mars can be highly dynamic and have daily and seasonal variations. Planetary-scale wavelike disturbances, for example, are frequently observed in Mars' polar winter atmosphere. Possible sources of the wave activity were suggested to be dynamical instabilities and quasi-stationary planetary waves, i.e. waves that arise predominantly via zonally asymmetric surface properties. For a comprehensive understanding of these phenomena, single layers of altitude have to be analyzed carefully and relations between different atmospheric quantities and interaction with the surface of Mars have to be considered. The CROSS DRIVE project tries to address the presentation of those data with a global view by means of virtual reality techniques. Complex orbiter data from spectrometer and observation data from Earth are combined with global circulation models and high-resolution terrain data and images available from Mars Express or MRO instruments. Scientists can interactively extract features from those dataset and can change visualization parameters in real-time in order to emphasize findings. Stereoscopic views allow for perception of the actual 3D behavior of Mars's atmosphere. A very important feature of the visualization system is the possibility to connect distributed workspaces together. This enables discussions between distributed working groups. The workspace can scale from virtual reality systems to expert desktop applications to web-based project portals. If multiple virtual environments are connected, the 3D position of each individual user is captured and used to depict the scientist as an avatar in the virtual world. The appearance of the avatar can also scale from simple annotations to complex avatars using tele-presence technology to reconstruct the users in 3D. Any change of the feature set (annotations, cutplanes, volume rendering, etc.) within the VR is immediately exchanged between all connected users. This allows that everybody is always

  20. Geological interpretation and analysis of surface based, spatially referenced planetary imagery data using PRoGIS 2.0 and Pro3D.

    NASA Astrophysics Data System (ADS)

    Barnes, R.; Gupta, S.; Giordano, M.; Morley, J. G.; Muller, J. P.; Tao, Y.; Sprinks, J.; Traxler, C.; Hesina, G.; Ortner, T.; Sander, K.; Nauschnegg, B.; Paar, G.; Willner, K.; Pajdla, T.

    2015-10-01

    We apply the capabilities of the geospatial environment PRoGIS 2.0 and the real time rendering viewer PRo3D to geological analysis of NASA's Mars Exploration Rover-B (MER-B Opportunity rover) and Mars Science Laboratory (MSL Curiosity rover) datasets. Short baseline and serendipitous long baseline stereo Pancam rover imagery are used to create 3D point clouds which can be combined with super-resolution images derived from Mars Reconnaissance Orbiter HiRISE orbital data, andsuper-resolution outcrop images derived from MER Pancam, as well as hand-lens scale images for geology and outcrop characterization at all scales. Data within the PRoViDE database are presented and accessed through the PRoGIS interface. Simple geological measurement tools are implemented within the PRoGIS and PRo3D web software to accurately measure the dip and strike of bedding in outcrops, create detailed stratigraphic logs for correlation between the areas investigated, and to develop realistic 3D models for the characterization of planetary surface processes. Annotation tools are being developed to aid discussion and dissemination of the observations within the planetary science community.

  1. A spatial query scheduler in a distributed environment

    NASA Astrophysics Data System (ADS)

    Zhou, Chunhui; Zhu, Xinyan; Xia, Yu; Su, Kehua

    2008-10-01

    Geographic Information System (GIS) is moving towards distribution and sharing. Distributed Spatial Database Systems (DSDBS) has attracted the attention of many scholars. This paper introduces the prospects of Distributed GIS (DGIS), and describes the definition of DSDBS and the existing problems. The researches in related fields are analyzed, including the research results in the traditional distributed relational database fields, the distributed spatial database fields and the spatial query optimization aspect. Grid technologies are developing forward, and grid will be turned into the standard distributed computing platform, therefore the application of DSDBS will be much broader than ever. The present studies on distributed spatial query focus on spatial join optimization. Researches on query scheduling are rare. In the process of constructing our test system for distributed spatial query, we find there are some replication nodes after the step of data localization. These nodes cause redundant computing of query processing. This paper gives a method to solve it based on the Query Scheduling Tree Model (QSTM). It also gives a detailed scheduling algorithm, and analyzes the effectiveness of the model and the algorithm.

  2. Cometary atmospheres: Modeling the spatial distribution of observed neutral radicals

    NASA Technical Reports Server (NTRS)

    Combi, M. R.

    1985-01-01

    Progress on modeling the spatial distributions of cometary radicals is described. The Monte Carlo particle-trajectory model was generalized to include the full time dependencies of initial comet expansion velocities, nucleus vaporization rates, photochemical lifetimes and photon emission rates which enter the problem through the comet's changing heliocentric distance and velocity. The effect of multiple collisions in the transition zone from collisional coupling to true free flow were also included. Currently available observations of the spatial distributions of the neutral radicals, as well as the latest available photochemical data were re-evaluated. Preliminary exploratory model results testing the effects of various processes on observable spatial distributions are also discussed.

  3. Spatial Distribution of Cyanobacteria in Modern Stromatolites

    NASA Technical Reports Server (NTRS)

    Prufert-Bebout, Lee; Dacles-Mariani, Jennifer; Herbert, Alice; DeVincenzi, Donald (Technical Monitor)

    2001-01-01

    Living stromatolites consist of complex microbial communities with distinct distribution patterns for different microbial groups. The cyanobacterial populations of Highborne Cay Bahamas exemplify this phenomenon. Field observations reveal distinct distribution patterns for several of these cyanobacterial species. To date 10 different cyanobacterial cultures, including both filamentous and endolithic species, have been isolated from these stromatolites. We will present data on the growth and motility characteristics as well as on the nutritional requirements of these isolates. These data will then be correlated with the field observed distributions for these species. Lastly laboratory simulations of stromatolites grown under various conditions of irradiance, flow and cyanobacterial community composition will be presented. These experiments allow us to evaluate our predictions regarding controls on cyanobacterial distribution.

  4. An interactive multiview 3D display system

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

  5. Single-Step 3-D Image Reconstruction in Magnetic Induction Tomography: Theoretical Limits of Spatial Resolution and Contrast to Noise Ratio

    PubMed Central

    Hollaus, Karl; Rosell-Ferrer, Javier; Merwa, Robert

    2006-01-01

    Magnetic induction tomography (MIT) is a low-resolution imaging modality for reconstructing the changes of the complex conductivity in an object. MIT is based on determining the perturbation of an alternating magnetic field, which is coupled from several excitation coils to the object. The conductivity distribution is reconstructed from the corresponding voltage changes induced in several receiver coils. Potential medical applications comprise the continuous, non-invasive monitoring of tissue alterations which are reflected in the change of the conductivity, e.g. edema, ventilation disorders, wound healing and ischemic processes. MIT requires the solution of an ill-posed inverse eddy current problem. A linearized version of this problem was solved for 16 excitation coils and 32 receiver coils with a model of two spherical perturbations within a cylindrical phantom. The method was tested with simulated measurement data. Images were reconstructed with a regularized single-step Gauss–Newton approach. Theoretical limits for spatial resolution and contrast/noise ratio were calculated and compared with the empirical results from a Monte-Carlo study. The conductivity perturbations inside a homogeneous cylinder were localized for a SNR between 44 and 64 dB. The results prove the feasibility of difference imaging with MIT and give some quantitative data on the limitations of the method. PMID:17031597

  6. Inner membrane fusion mediates spatial distribution of axonal mitochondria

    PubMed Central

    Yu, Yiyi; Lee, Hao-Chih; Chen, Kuan-Chieh; Suhan, Joseph; Qiu, Minhua; Ba, Qinle; Yang, Ge

    2016-01-01

    In eukaryotic cells, mitochondria form a dynamic interconnected network to respond to changing needs at different subcellular locations. A fundamental yet unanswered question regarding this network is whether, and if so how, local fusion and fission of individual mitochondria affect their global distribution. To address this question, we developed high-resolution computational image analysis techniques to examine the relations between mitochondrial fusion/fission and spatial distribution within the axon of Drosophila larval neurons. We found that stationary and moving mitochondria underwent fusion and fission regularly but followed different spatial distribution patterns and exhibited different morphology. Disruption of inner membrane fusion by knockdown of dOpa1, Drosophila Optic Atrophy 1, not only increased the spatial density of stationary and moving mitochondria but also changed their spatial distributions and morphology differentially. Knockdown of dOpa1 also impaired axonal transport of mitochondria. But the changed spatial distributions of mitochondria resulted primarily from disruption of inner membrane fusion because knockdown of Milton, a mitochondrial kinesin-1 adapter, caused similar transport velocity impairment but different spatial distributions. Together, our data reveals that stationary mitochondria within the axon interconnect with moving mitochondria through fusion and fission and that local inner membrane fusion between individual mitochondria mediates their global distribution. PMID:26742817

  7. Inner membrane fusion mediates spatial distribution of axonal mitochondria.

    PubMed

    Yu, Yiyi; Lee, Hao-Chih; Chen, Kuan-Chieh; Suhan, Joseph; Qiu, Minhua; Ba, Qinle; Yang, Ge

    2016-01-08

    In eukaryotic cells, mitochondria form a dynamic interconnected network to respond to changing needs at different subcellular locations. A fundamental yet unanswered question regarding this network is whether, and if so how, local fusion and fission of individual mitochondria affect their global distribution. To address this question, we developed high-resolution computational image analysis techniques to examine the relations between mitochondrial fusion/fission and spatial distribution within the axon of Drosophila larval neurons. We found that stationary and moving mitochondria underwent fusion and fission regularly but followed different spatial distribution patterns and exhibited different morphology. Disruption of inner membrane fusion by knockdown of dOpa1, Drosophila Optic Atrophy 1, not only increased the spatial density of stationary and moving mitochondria but also changed their spatial distributions and morphology differentially. Knockdown of dOpa1 also impaired axonal transport of mitochondria. But the changed spatial distributions of mitochondria resulted primarily from disruption of inner membrane fusion because knockdown of Milton, a mitochondrial kinesin-1 adapter, caused similar transport velocity impairment but different spatial distributions. Together, our data reveals that stationary mitochondria within the axon interconnect with moving mitochondria through fusion and fission and that local inner membrane fusion between individual mitochondria mediates their global distribution.

  8. Inner membrane fusion mediates spatial distribution of axonal mitochondria

    NASA Astrophysics Data System (ADS)

    Yu, Yiyi; Lee, Hao-Chih; Chen, Kuan-Chieh; Suhan, Joseph; Qiu, Minhua; Ba, Qinle; Yang, Ge

    2016-01-01

    In eukaryotic cells, mitochondria form a dynamic interconnected network to respond to changing needs at different subcellular locations. A fundamental yet unanswered question regarding this network is whether, and if so how, local fusion and fission of individual mitochondria affect their global distribution. To address this question, we developed high-resolution computational image analysis techniques to examine the relations between mitochondrial fusion/fission and spatial distribution within the axon of Drosophila larval neurons. We found that stationary and moving mitochondria underwent fusion and fission regularly but followed different spatial distribution patterns and exhibited different morphology. Disruption of inner membrane fusion by knockdown of dOpa1, Drosophila Optic Atrophy 1, not only increased the spatial density of stationary and moving mitochondria but also changed their spatial distributions and morphology differentially. Knockdown of dOpa1 also impaired axonal transport of mitochondria. But the changed spatial distributions of mitochondria resulted primarily from disruption of inner membrane fusion because knockdown of Milton, a mitochondrial kinesin-1 adapter, caused similar transport velocity impairment but different spatial distributions. Together, our data reveals that stationary mitochondria within the axon interconnect with moving mitochondria through fusion and fission and that local inner membrane fusion between individual mitochondria mediates their global distribution.

  9. Volumetric 3D Display System with Static Screen

    NASA Technical Reports Server (NTRS)

    Geng, Jason

    2011-01-01

    Current display technology has relied on flat, 2D screens that cannot truly convey the third dimension of visual information: depth. In contrast to conventional visualization that is primarily based on 2D flat screens, the volumetric 3D display possesses a true 3D display volume, and places physically each 3D voxel in displayed 3D images at the true 3D (x,y,z) spatial position. Each voxel, analogous to a pixel in a 2D image, emits light from that position to form a real 3D image in the eyes of the viewers. Such true volumetric 3D display technology provides both physiological (accommodation, convergence, binocular disparity, and motion parallax) and psychological (image size, linear perspective, shading, brightness, etc.) depth cues to human visual systems to help in the perception of 3D objects. In a volumetric 3D display, viewers can watch the displayed 3D images from a completely 360 view without using any special eyewear. The volumetric 3D display techniques may lead to a quantum leap in information display technology and can dramatically change the ways humans interact with computers, which can lead to significant improvements in the efficiency of learning and knowledge management processes. Within a block of glass, a large amount of tiny dots of voxels are created by using a recently available machining technique called laser subsurface engraving (LSE). The LSE is able to produce tiny physical crack points (as small as 0.05 mm in diameter) at any (x,y,z) location within the cube of transparent material. The crack dots, when illuminated by a light source, scatter the light around and form visible voxels within the 3D volume. The locations of these tiny voxels are strategically determined such that each can be illuminated by a light ray from a high-resolution digital mirror device (DMD) light engine. The distribution of these voxels occupies the full display volume within the static 3D glass screen. This design eliminates any moving screen seen in previous

  10. Spatial Distribution of Small Water Body Types across Indiana Ecoregions

    EPA Science Inventory

    Due to their large numbers and biogeochemical activity, small water bodies (SWB), such as ponds and wetlands, can have substantial cumulative effects on hydrologic, biogeochemical, and biological processes; yet the spatial distributions of various SWB types are often unknown. Usi...

  11. Spatial Distribution of Small Water Body Types in Indiana Ecoregions

    EPA Science Inventory

    Due to their large numbers and biogeochemical activity, small water bodies (SWBs), such as ponds and wetlands, can have substantial cumulative effects on hydrologic and biogeochemical processes. Using updated National Wetland Inventory data, we describe the spatial distribution o...

  12. The Spatial Distribution of Attention within and across Objects

    ERIC Educational Resources Information Center

    Hollingworth, Andrew; Maxcey-Richard, Ashleigh M.; Vecera, Shaun P.

    2012-01-01

    Attention operates to select both spatial locations and perceptual objects. However, the specific mechanism by which attention is oriented to objects is not well understood. We examined the means by which object structure constrains the distribution of spatial attention (i.e., a "grouped array"). Using a modified version of the Egly et…

  13. Volumetric medical image compression using 3D listless embedded block partitioning.

    PubMed

    Senapati, Ranjan K; Prasad, P M K; Swain, Gandharba; Shankar, T N

    2016-01-01

    This paper presents a listless variant of a modified three-dimensional (3D)-block coding algorithm suitable for medical image compression. A higher degree of correlation is achieved by using a 3D hybrid transform. The 3D hybrid transform is performed by a wavelet transform in the spatial dimension and a Karhunen-Loueve transform in the spectral dimension. The 3D transformed coefficients are arranged in a one-dimensional (1D) fashion, as in the hierarchical nature of the wavelet-coefficient distribution strategy. A novel listless block coding algorithm is applied to the mapped 1D coefficients which encode in an ordered-bit-plane fashion. The algorithm originates from the most significant bit plane and terminates at the least significant bit plane to generate an embedded bit stream, as in 3D-SPIHT. The proposed algorithm is called 3D hierarchical listless block (3D-HLCK), which exhibits better compression performance than that exhibited by 3D-SPIHT. Further, it is highly competitive with some of the state-of-the-art 3D wavelet coders for a wide range of bit rates for magnetic resonance, digital imaging and communication in medicine and angiogram images. 3D-HLCK provides rate and resolution scalability similar to those provided by 3D-SPIHT and 3D-SPECK. In addition, a significant memory reduction is achieved owing to the listless nature of 3D-HLCK.

  14. Effect of Energetic Ion on Spatial Distribution of Recombining Plasma

    NASA Astrophysics Data System (ADS)

    Okamoto, A.; Daibo, A.; Kitajima, S.; Kumagai, T.; Takahashi, H.; Takahashi, T.; Tsubota, S.

    Spatial distribution of electron density is considered. By using a one-dimensional recombining plasma model, effects of transient energetic ion flux are investigated. The time response of the system against the transient flux is dominated by the recombination frequency. The magnitude of modification of the spatial distribution is determined by the ratio between the ionization due to the energetic ion and the recombination of the bulk plasma.

  15. SU-E-T-35: An Investigation of the Accuracy of Cervical IMRT Dose Distribution Using 2D/3D Ionization Chamber Arrays System and Monte Carlo Simulation

    SciTech Connect

    Zhang, Y; Yang, J; Liu, H; Liu, D

    2014-06-01

    Purpose: The purpose of this work is to compare the verification results of three solutions (2D/3D ionization chamber arrays measurement and Monte Carlo simulation), the results will help make a clinical decision as how to do our cervical IMRT verification. Methods: Seven cervical cases were planned with Pinnacle 8.0m to meet the clinical acceptance criteria. The plans were recalculated in the Matrixx and Delta4 phantom with the accurate plans parameters. The plans were also recalculated by Monte Carlo using leaf sequences and MUs for individual plans of every patient, Matrixx and Delta4 phantom. All plans of Matrixx and Delta4 phantom were delivered and measured. The dose distribution of iso slice, dose profiles, gamma maps of every beam were used to evaluate the agreement. Dose-volume histograms were also compared. Results: The dose distribution of iso slice and dose profiles from Pinnacle calculation were in agreement with the Monte Carlo simulation, Matrixx and Delta4 measurement. A 95.2%/91.3% gamma pass ratio was obtained between the Matrixx/Delta4 measurement and Pinnacle distributions within 3mm/3% gamma criteria. A 96.4%/95.6% gamma pass ratio was obtained between the Matrixx/Delta4 measurement and Monte Carlo simulation within 2mm/2% gamma criteria, almost 100% gamma pass ratio within 3mm/3% gamma criteria. The DVH plot have slightly differences between Pinnacle and Delta4 measurement as well as Pinnacle and Monte Carlo simulation, but have excellent agreement between Delta4 measurement and Monte Carlo simulation. Conclusion: It was shown that Matrixx/Delta4 and Monte Carlo simulation can be used very efficiently to verify cervical IMRT delivery. In terms of Gamma value the pass ratio of Matrixx was little higher, however, Delta4 showed more problem fields. The primary advantage of Delta4 is the fact it can measure true 3D dosimetry while Monte Carlo can simulate in patients CT images but not in phantom.

  16. Reconstructing Spatial Distributions from Anonymized Locations

    SciTech Connect

    Horey, James L; Forrest, Stephanie; Groat, Michael

    2012-01-01

    Devices such as mobile phones, tablets, and sensors are often equipped with GPS that accurately report a person's location. Combined with wireless communication, these devices enable a wide range of new social tools and applications. These same qualities, however, leave location-aware applications vulnerable to privacy violations. This paper introduces the Negative Quad Tree, a privacy protection method for location aware applications. The method is broadly applicable to applications that use spatial density information, such as social applications that measure the popularity of social venues. The method employs a simple anonymization algorithm running on mobile devices, and a more complex reconstruction algorithm on a central server. This strategy is well suited to low-powered mobile devices. The paper analyzes the accuracy of the reconstruction method in a variety of simulated and real-world settings and demonstrates that the method is accurate enough to be used in many real-world scenarios.

  17. Spatial distribution of Dermacentor reticulatus in Romania.

    PubMed

    Chitimia-Dobler, Lidia

    2015-11-30

    Dermacentor reticulatus (Fabricius, 1794), also known as the marsh tick or ornate dog tick is the second most significant vector (next to Ixodes ricinus) of protozoan, rickettsial and viral pathogens in Europe. Until now, only limited information on the distribution of D. reticulatus in Romania is available. A study was conducted on the distribution of D. reticulatus in Romania during 2012-2014. In this study, D. reticulatus was detected in 17 counties, in 14 of which the species was recorded for the first time. Tick activity was evident throughout the year, except during July and August. Additionally, D. reticulatus was recorded for the first time in Romania from wild boar, foxes and humans. These data suggest that this tick species has a broader geographic range and may have more veterinary and medical importance than previously known.

  18. 3D Imaging.

    ERIC Educational Resources Information Center

    Hastings, S. K.

    2002-01-01

    Discusses 3 D imaging as it relates to digital representations in virtual library collections. Highlights include X-ray computed tomography (X-ray CT); the National Science Foundation (NSF) Digital Library Initiatives; output peripherals; image retrieval systems, including metadata; and applications of 3 D imaging for libraries and museums. (LRW)

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

    NASA Astrophysics Data System (ADS)

    Schild, Jonas; Seele, Sven; Masuch, Maic

    2012-03-01

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

  20. Volumetric image display for complex 3D data visualization

    NASA Astrophysics Data System (ADS)

    Tsao, Che-Chih; Chen, Jyh Shing

    2000-05-01

    A volumetric image display is a new display technology capable of displaying computer generated 3D images in a volumetric space. Many viewers can walk around the display and see the image from omni-directions simultaneously without wearing any glasses. The image is real and possesses all major elements in both physiological and psychological depth cues. Due to the volumetric nature of its image, the VID can provide the most natural human-machine interface in operations involving 3D data manipulation and 3D targets monitoring. The technology creates volumetric 3D images by projecting a series of profiling images distributed in the space form a volumetric image because of the after-image effect of human eyes. Exemplary applications in biomedical image visualization were tested on a prototype display, using different methods to display a data set from Ct-scans. The features of this display technology make it most suitable for applications that require quick understanding of the 3D relations, need frequent spatial interactions with the 3D images, or involve time-varying 3D data. It can also be useful for group discussion and decision making.

  1. New ATCA, ALMA and VISIR observations of the candidate LBV SK -67 266 (S61): the nebular mass from modelling 3D density distributions

    NASA Astrophysics Data System (ADS)

    Agliozzo, C.; Nikutta, R.; Pignata, G.; Phillips, N. M.; Ingallinera, A.; Buemi, C.; Umana, G.; Leto, P.; Trigilio, C.; Noriega-Crespo, A.; Paladini, R.; Bufano, F.; Cavallaro, F.

    2017-04-01

    We present new observations of the nebula around the Magellanic candidate Luminous Blue Variable S61. These comprise high-resolution data acquired with the Australia Telescope Compact Array (ATCA), the Atacama Large Millimetre/Submillimetre Array (ALMA), and the VLT Imager and Spectrometer for mid Infrared (VISIR) at the Very Large Telescope. The nebula was detected only in the radio, up to 17 GHz. The 17 GHz ATCA map, with 0.8 arcsec resolution, allowed a morphological comparison with the Hα Hubble Space Telescope image. The radio nebula resembles a spherical shell, as in the optical. The spectral index map indicates that the radio emission is due to free-free transitions in the ionized, optically thin gas, but there are hints of inhomogeneities. We present our new public code RHOCUBE to model 3D density distributions and determine via Bayesian inference the nebula's geometric parameters. We applied the code to model the electron density distribution in the S61 nebula. We found that different distributions fit the data, but all of them converge to the same ionized mass, ∼ 0.1 M⊙, which is an order of magnitude smaller than previous estimates. We show how the nebula models can be used to derive the mass-loss history with high-temporal resolution. The nebula was probably formed through stellar winds, rather than eruptions. From the ALMA and VISIR non-detections, plus the derived extinction map, we deduce that the infrared emission observed by space telescopes must arise from extended, diffuse dust within the ionized region.

  2. Effect of type of luting agents on stress distribution in the bone surrounding implants supporting a three-unit fixed dental prosthesis: 3D finite element analysis

    PubMed Central

    Ghasemi, Ehsan; Abedian, Alireza; Iranmanesh, Pedram; Khazaei, Saber

    2015-01-01

    Background: Osseointegration of dental implants is influenced by many biomechanical factors that may be related to stress distribution. The aim of this study was to evaluate the effect of type of luting agent on stress distribution in the bone surrounding implants, which support a three-unit fixed dental prosthesis (FDP) using finite element (FE) analysis. Materials and Methods: A 3D FE model of a three-unit FDP was designed replacing the maxillary first molar with maxillary second premolar and second molar as the abutments using CATIA V5R18 software and analyzed with ABAQUS/CAE 6.6 version. The model was consisted of 465108 nodes and 86296 elements and the luting agent thickness was considered 25 μm. Three load conditions were applied on eight points in each functional cusp in horizontal (57.0 N), vertical (200.0 N) and oblique (400.0 N, θ = 120°) directions. Five different luting agents were evaluated. All materials were assumed to be linear elastic, homogeneous, time independent and isotropic. Results: For all luting agent types, the stress distribution pattern in the cortical bone, connectors, implant and abutment regions was almost uniform among the three loads. Furthermore, the maximum von Mises stress of the cortical bone was at the palatal side of second premolar. Likewise, the maximum von Mises stress in the connector region was in the top and bottom of this part. Conclusion: Luting agents transfer the load to cortical bone and different types of luting agents do not affect the pattern of load transfer. PMID:25709676

  3. Guaranteed spatial initialization of distributed spacecraft formations

    NASA Technical Reports Server (NTRS)

    Scharf, Daniel P.; Ploen, Scott R.; Hadaegh, Fred Y.; Sohl, Garett A.

    2004-01-01

    In a precious paper the authors developed a formation initialization (FI) algorithm for a deep space, N-spacecraft formation. It was demonstrated analytically that this FI contribution of this paper is to extend this planar guarantee to deep space formations with arbitrary initial conditions. As part of the guarantee of initialization, a bound on the time-to-initialize is obtained. The guaranteed FI algorithm is then demonstrated for a two-spacecraft formation with realistic deep space mission constraints (e.g. limited field-of-view relative sensors and attitude constraints). The two-spacecraft scenario is challenging in that it has the least relative sensor field-of-view overlap. Finally, for this scenario, the distribution of time-to-initialize is characterized through a 150,000-case Monte Carlo analysis.

  4. 3D Bioprinting for Organ Regeneration.

    PubMed

    Cui, Haitao; Nowicki, Margaret; Fisher, John P; Zhang, Lijie Grace

    2017-01-01

    Regenerative medicine holds the promise of engineering functional tissues or organs to heal or replace abnormal and necrotic tissues/organs, offering hope for filling the gap between organ shortage and transplantation needs. Three-dimensional (3D) bioprinting is evolving into an unparalleled biomanufacturing technology due to its high-integration potential for patient-specific designs, precise and rapid manufacturing capabilities with high resolution, and unprecedented versatility. It enables precise control over multiple compositions, spatial distributions, and architectural accuracy/complexity, therefore achieving effective recapitulation of microstructure, architecture, mechanical properties, and biological functions of target tissues and organs. Here we provide an overview of recent advances in 3D bioprinting technology, as well as design concepts of bioinks suitable for the bioprinting process. We focus on the applications of this technology for engineering living organs, focusing more specifically on vasculature, neural networks, the heart and liver. We conclude with current challenges and the technical perspective for further development of 3D organ bioprinting.

  5. The Effects of Realistic Synaptic Distribution and 3D Geometry on Signal Integration and Extracellular Field Generation of Hippocampal Pyramidal Cells and Inhibitory Neurons

    PubMed Central

    Gulyás, Attila I.; Freund, Tamás F.; Káli, Szabolcs

    2016-01-01

    In vivo and in vitro multichannel field and somatic intracellular recordings are frequently used to study mechanisms of network pattern generation. When interpreting these data, neurons are often implicitly considered as electrotonically compact cylinders with a homogeneous distribution of excitatory and inhibitory inputs. However, the actual distributions of dendritic length, diameter, and the densities of excitatory and inhibitory input are non-uniform and cell type-specific. We first review quantitative data on the dendritic structure and synaptic input and output distribution of pyramidal cells (PCs) and interneurons in the hippocampal CA1 area. Second, using multicompartmental passive models of four different types of neurons, we quantitatively explore the effect of differences in dendritic structure and synaptic distribution on the errors and biases of voltage clamp measurements of inhibitory and excitatory postsynaptic currents. Finally, using the 3-dimensional distribution of dendrites and synaptic inputs we calculate how different inhibitory and excitatory inputs contribute to the generation of local field potential in the hippocampus. We analyze these effects at different realistic background activity levels as synaptic bombardment influences neuronal conductance and thus the propagation of signals in the dendritic tree. We conclude that, since dendrites are electrotonically long and entangled in 3D, somatic intracellular and field potential recordings miss the majority of dendritic events in some cell types, and thus overemphasize the importance of perisomatic inhibitory inputs and belittle the importance of complex dendritic processing. Modeling results also suggest that PCs and inhibitory neurons probably use different input integration strategies. In PCs, second- and higher-order thin dendrites are relatively well-isolated from each other, which may support branch-specific local processing as suggested by studies of active dendritic integration. In

  6. The Effects of Realistic Synaptic Distribution and 3D Geometry on Signal Integration and Extracellular Field Generation of Hippocampal Pyramidal Cells and Inhibitory Neurons.

    PubMed

    Gulyás, Attila I; Freund, Tamás F; Káli, Szabolcs

    2016-01-01

    In vivo and in vitro multichannel field and somatic intracellular recordings are frequently used to study mechanisms of network pattern generation. When interpreting these data, neurons are often implicitly considered as electrotonically compact cylinders with a homogeneous distribution of excitatory and inhibitory inputs. However, the actual distributions of dendritic length, diameter, and the densities of excitatory and inhibitory input are non-uniform and cell type-specific. We first review quantitative data on the dendritic structure and synaptic input and output distribution of pyramidal cells (PCs) and interneurons in the hippocampal CA1 area. Second, using multicompartmental passive models of four different types of neurons, we quantitatively explore the effect of differences in dendritic structure and synaptic distribution on the errors and biases of voltage clamp measurements of inhibitory and excitatory postsynaptic currents. Finally, using the 3-dimensional distribution of dendrites and synaptic inputs we calculate how different inhibitory and excitatory inputs contribute to the generation of local field potential in the hippocampus. We analyze these effects at different realistic background activity levels as synaptic bombardment influences neuronal conductance and thus the propagation of signals in the dendritic tree. We conclude that, since dendrites are electrotonically long and entangled in 3D, somatic intracellular and field potential recordings miss the majority of dendritic events in some cell types, and thus overemphasize the importance of perisomatic inhibitory inputs and belittle the importance of complex dendritic processing. Modeling results also suggest that PCs and inhibitory neurons probably use different input integration strategies. In PCs, second- and higher-order thin dendrites are relatively well-isolated from each other, which may support branch-specific local processing as suggested by studies of active dendritic integration. In

  7. Characterization of flow pattern transitions for horizontal liquid-liquid pipe flows by using multi-scale distribution entropy in coupled 3D phase space

    NASA Astrophysics Data System (ADS)

    Zhai, Lu-Sheng; Zong, Yan-Bo; Wang, Hong-Mei; Yan, Cong; Gao, Zhong-Ke; Jin, Ning-De

    2017-03-01

    Horizontal oil-water two-phase flows often exist in many industrial processes. Uncovering the dynamic mechanism of the flow pattern transition is of great significance for modeling the flow parameters. In this study we propose a method called multi-scale distribution entropy (MSDE) in a coupled 3D phase space, and use it to characterize the flow pattern transitions in horizontal oil-water two-phase flows. Firstly, the proposed MSDE is validated with Lorenz system and ARFIMA processes. Interestingly, it is found that the MSDE is dramatically associated with the cross-correlations of the coupled time series. Then, through conducting the experiment of horizontal oil-water two-phase flows, the upstream and downstream flow information is collected using a conductance cross-correlation velocity probe. The coupled cross-correlated signals are investigated using the MSDE method, and the results indicate that the MSDE is an effective tool uncovering the complex dynamic behaviors of flow pattern transitions.

  8. Investigation of the 3D temperature distribution patterns above the Antarctic Peninsula using remote sensing data - A contribution for polar climate monitoring

    NASA Astrophysics Data System (ADS)

    Wachter, Paul; Höppner, Kathrin; Jacobeit, Jucundus; Diedrich, Erhard

    2015-04-01

    West Antarctica and the Antarctic Peninsula are in the focus of current studies on a changing environment and climate of the polar regions. A recently founded Junior Researchers Group at the German Aerospace Center (DLR) is studying changing processes in cryosphere and atmosphere above the Antarctic Peninsula. It is the aim of the group to make use of long-term remote sensing data sets of the land and ice surfaces and the atmosphere in order to characterize environmental changes in this highly sensitive region. One of the PhD projects focuses on the investigation of the 3D temperature distribution patterns above the Antarctic Peninsula. Temperature data sets ranging from MODIS land surface temperatures up to middle atmosphere data of AURA/MLS will be evaluated over the last approx. 12 years. This 3-dimensional view allows comprehensive investigations of the thermal structure and spatio-temporal characteristics of the southern polar atmosphere. Tropospheric data sets will be analyzed by multivariate statistical methods and will allow the identification of dominant atmospheric circulation patterns as well as their temporal variability. An overview of the data sets and first results will be presented.

  9. Solar Wind Halo Formation by the Scattering of the Strahl: Direct Cluster/PEACE Observations of the 3D Velocity Distribution Function

    NASA Astrophysics Data System (ADS)

    Vinas, A. F.; Gurgiolo, C. A.; Nieves-Chinchilla, T.; Wendel, D. E.; Goldstein, M. L.; Fazakerley, A. N.

    2010-12-01

    The current hypothesis of the formation of the solar wind halo electrons is that they are produced from scattering of the strahl. This hypothesis is strengthened by direct observations of the strahl electrons being scattered into the halo in an isolated event. On frequent occasions we have observed in electron angular skymaps (Phi/Theta-plots) of the electron 3D velocity distribution functions, a bursty-filament of particles connecting the strahl to the solar wind core-halo. These are seen over a limited energy range. The observation implies that the formation of the halo is not a continuous process but occurs in bursts in regions where conditions for wave growth providing the scattering are optimum. Sometimes, observations indicates that the strahl component is anisotropic (Tper/Tpal ~ 2). This provides a possible free energy source for the excitation of whistler waves as a possible scattering mechanism, however this condition is not always observed. The empirical observational evidence between the halo and the strahl suggests that the strahl population may be, at least in part, the source of the halo component.

  10. Stereo 3-D Vision in Teaching Physics

    ERIC Educational Resources Information Center

    Zabunov, Svetoslav

    2012-01-01

    Stereo 3-D vision is a technology used to present images on a flat surface (screen, paper, etc.) and at the same time to create the notion of three-dimensional spatial perception of the viewed scene. A great number of physical processes are much better understood when viewed in stereo 3-D vision compared to standard flat 2-D presentation. The…

  11. Monte Carlo simulations of GeoPET experiments: 3D images of tracer distributions (18F, 124I and 58Co) in Opalinus clay, anhydrite and quartz

    NASA Astrophysics Data System (ADS)

    Zakhnini, Abdelhamid; Kulenkampff, Johannes; Sauerzapf, Sophie; Pietrzyk, Uwe; Lippmann-Pipke, Johanna

    2013-08-01

    Understanding conservative fluid flow and reactive tracer transport in soils and rock formations requires quantitative transport visualization methods in 3D+t. After a decade of research and development we established the GeoPET as a non-destructive method with unrivalled sensitivity and selectivity, with due spatial and temporal resolution by applying Positron Emission Tomography (PET), a nuclear medicine imaging method, to dense rock material. Requirements for reaching the physical limit of image resolution of nearly 1 mm are (a) a high-resolution PET-camera, like our ClearPET scanner (Raytest), and (b) appropriate correction methods for scatter and attenuation of 511 keV—photons in the dense geological material. The latter are by far more significant in dense geological material than in human and small animal body tissue (water). Here we present data from Monte Carlo simulations (MCS) reflecting selected GeoPET experiments. The MCS consider all involved nuclear physical processes of the measurement with the ClearPET-system and allow us to quantify the sensitivity of the method and the scatter fractions in geological media as function of material (quartz, Opalinus clay and anhydrite compared to water), PET isotope (18F, 58Co and 124I), and geometric system parameters. The synthetic data sets obtained by MCS are the basis for detailed performance assessment studies allowing for image quality improvements. A scatter correction method is applied exemplarily by subtracting projections of simulated scattered coincidences from experimental data sets prior to image reconstruction with an iterative reconstruction process.

  12. Development of Spatial Distribution Patterns by Biofilm Cells

    PubMed Central

    Haagensen, Janus A. J.; Hansen, Susse K.; Christensen, Bjarke B.; Molin, Søren

    2015-01-01

    Confined spatial patterns of microbial distribution are prevalent in nature, such as in microbial mats, soil communities, and water stream biofilms. The symbiotic two-species consortium of Pseudomonas putida and Acinetobacter sp. strain C6, originally isolated from a creosote-polluted aquifer, has evolved a distinct spatial organization in the laboratory that is characterized by an increased fitness and productivity. In this consortium, P. putida is reliant on microcolonies formed by Acinetobacter sp. C6, to which it attaches. Here we describe the processes that lead to the microcolony pattern by Acinetobacter sp. C6. Ecological spatial pattern analyses revealed that the microcolonies were not entirely randomly distributed and instead were arranged in a uniform pattern. Detailed time-lapse confocal microscopy at the single-cell level demonstrated that the spatial pattern was the result of an intriguing self-organization: small multicellular clusters moved along the surface to fuse with one another to form microcolonies. This active distribution capability was dependent on environmental factors (carbon source and oxygen) and historical contingency (formation of phenotypic variants). The findings of this study are discussed in the context of species distribution patterns observed in macroecology, and we summarize observations about the processes involved in coadaptation between P. putida and Acinetobacter sp. C6. Our results contribute to an understanding of spatial species distribution patterns as they are observed in nature, as well as the ecology of engineered communities that have the potential for enhanced and sustainable bioprocessing capacity. PMID:26116674

  13. Analysis of the energy distribution of interface traps related to tunnel oxide degradation using charge pumping techniques for 3D NAND flash applications

    SciTech Connect

    An, Ho-Myoung; Kim, Hee-Dong; Kim, Tae Geun

    2013-12-15

    Graphical abstract: The degradation tendency extracted by CP technique was almost the same in both the bulk-type and TFT-type cells. - Highlights: • D{sub it} is directly investigated from bulk-type and TFT-type CTF memory. • Charge pumping technique was employed to analyze the D{sub it} information. • To apply the CP technique to monitor the reliability of the 3D NAND flash. - Abstract: The energy distribution and density of interface traps (D{sub it}) are directly investigated from bulk-type and thin-film transistor (TFT)-type charge trap flash memory cells with tunnel oxide degradation, under program/erase (P/E) cycling using a charge pumping (CP) technique, in view of application in a 3-demension stackable NAND flash memory cell. After P/E cycling in bulk-type devices, the interface trap density gradually increased from 1.55 × 10{sup 12} cm{sup −2} eV{sup −1} to 3.66 × 10{sup 13} cm{sup −2} eV{sup −1} due to tunnel oxide damage, which was consistent with the subthreshold swing and transconductance degradation after P/E cycling. Its distribution moved toward shallow energy levels with increasing cycling numbers, which coincided with the decay rate degradation with short-term retention time. The tendency extracted with the CP technique for D{sub it} of the TFT-type cells was similar to those of bulk-type cells.

  14. 3-D object-oriented image analysis of geophysical data

    NASA Astrophysics Data System (ADS)

    Fadel, I.; Kerle, N.; van der Meijde, M.

    2014-07-01

    Geophysical data are the main source of information about the subsurface. Geophysical techniques are, however, highly non-unique in determining specific physical parameters and boundaries of subsurface objects. To obtain actual physical information, an inversion process is often applied, in which measurements at or above the Earth surface are inverted into a 2- or 3-D subsurface spatial distribution of the physical property. Interpreting these models into structural objects, related to physical processes, requires a priori knowledge and expert analysis which is susceptible to subjective choices and is therefore often non-repeatable. In this research, we implemented a recently introduced object-based approach to interpret the 3-D inversion results of a single geophysical technique using the available a priori information and the physical and geometrical characteristics of the interpreted objects. The introduced methodology is semi-automatic and repeatable, and allows the extraction of subsurface structures using 3-D object-oriented image analysis (3-D OOA) in an objective knowledge-based classification scheme. The approach allows for a semi-objective setting of thresholds that can be tested and, if necessary, changed in a very fast and efficient way. These changes require only changing the thresholds used in a so-called ruleset, which is composed of algorithms that extract objects from a 3-D data cube. The approach is tested on a synthetic model, which is based on a priori knowledge on objects present in the study area (Tanzania). Object characteristics and thresholds were well defined in a 3-D histogram of velocity versus depth, and objects were fully retrieved. The real model results showed how 3-D OOA can deal with realistic 3-D subsurface conditions in which the boundaries become fuzzy, the object extensions become unclear and the model characteristics vary with depth due to the different physical conditions. As expected, the 3-D histogram of the real data was

  15. GPU-based, parallel-line, omni-directional integration of measured acceleration field to obtain the 3D pressure distribution

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Zhang, Cao; Katz, Joseph

    2016-11-01

    A PIV based method to reconstruct the volumetric pressure field by direct integration of the 3D material acceleration directions has been developed. Extending the 2D virtual-boundary omni-directional method (Omni2D, Liu & Katz, 2013), the new 3D parallel-line omni-directional method (Omni3D) integrates the material acceleration along parallel lines aligned in multiple directions. Their angles are set by a spherical virtual grid. The integration is parallelized on a Tesla K40c GPU, which reduced the computing time from three hours to one minute for a single realization. To validate its performance, this method is utilized to calculate the 3D pressure fields in isotropic turbulence and channel flow using the JHU DNS Databases (http://turbulence.pha.jhu.edu). Both integration of the DNS acceleration as well as acceleration from synthetic 3D particles are tested. Results are compared to other method, e.g. solution to the Pressure Poisson Equation (e.g. PPE, Ghaemi et al., 2012) with Bernoulli based Dirichlet boundary conditions, and the Omni2D method. The error in Omni3D prediction is uniformly low, and its sensitivity to acceleration errors is local. It agrees with the PPE/Bernoulli prediction away from the Dirichlet boundary. The Omni3D method is also applied to experimental data obtained using tomographic PIV, and results are correlated with deformation of a compliant wall. ONR.

  16. AE3D

    SciTech Connect

    Spong, Donald A

    2016-06-20

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

  17. [Real time 3D echocardiography

    NASA Technical Reports Server (NTRS)

    Bauer, F.; Shiota, T.; Thomas, J. D.

    2001-01-01

    Three-dimensional representation of the heart is an old concern. Usually, 3D reconstruction of the cardiac mass is made by successive acquisition of 2D sections, the spatial localisation and orientation of which require complex guiding systems. More recently, the concept of volumetric acquisition has been introduced. A matricial emitter-receiver probe complex with parallel data processing provides instantaneous of a pyramidal 64 degrees x 64 degrees volume. The image is restituted in real time and is composed of 3 planes (planes B and C) which can be displaced in all spatial directions at any time during acquisition. The flexibility of this system of acquisition allows volume and mass measurement with greater accuracy and reproducibility, limiting inter-observer variability. Free navigation of the planes of investigation allows reconstruction for qualitative and quantitative analysis of valvular heart disease and other pathologies. Although real time 3D echocardiography is ready for clinical usage, some improvements are still necessary to improve its conviviality. Then real time 3D echocardiography could be the essential tool for understanding, diagnosis and management of patients.

  18. 3D multiplexed immunoplasmonics microscopy

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

  19. Estimating and Modeling Gene Flow for a Spatially Distributed Species

    DTIC Science & Technology

    1991-01-01

    AD-A238 221/I1 Estimating and modeling gene flow for a spatially distributed species JUL1 7 1961T. Burr 1 and T. V. Kurien 2 Department of Statistics...modeling gene flow for a spatially distributed species. By T. Burr and T. V. Kurien Departmeii Of Statistics Florida State University Abstract This...chromosome (referred to as a locus) is a meaningful string of several hundred symbols called a gene . Typ- ically there are many loci on a chromosome. The

  20. Micro-CT observations of the 3D distribution of calcium oxalate crystals in cotyledons during maturation and germination in Lotus miyakojimae seeds.

    PubMed

    Yamauchi, Daisuke; Tamaoki, Daisuke; Hayami, Masato; Takeuchi, Miyuki; Karahara, Ichirou; Sato, Mayuko; Toyooka, Kiminori; Nishioka, Hiroshi; Terada, Yasuko; Uesugi, Kentaro; Takano, Hidekazu; Kagoshima, Yasushi; Mineyuki, Yoshinobu

    2013-06-01

    The cotyledon of legume seeds is a storage organ that provides nutrients for seed germination and seedling growth. The spatial and temporal control of the degradation processes within cotyledons has not been elucidated. Calcium oxalate (CaOx) crystals, a common calcium deposit in plants, have often been reported to be present in legume seeds. In this study, micro-computed tomography (micro-CT) was employed at the SPring-8 facility to examine the three-dimensional distribution of crystals inside cotyledons during seed maturation and germination of Lotus miyakojimae (previously Lotus japonicus accession Miyakojima MG-20). Using this technique, we could detect the outline of the embryo, void spaces in seeds and the cotyledon venation pattern. We found several sites that strongly inhibited X-ray transmission within the cotyledons. Light and polarizing microscopy confirmed that these areas corresponded to CaOx crystals. Three-dimensional observations of dry seeds indicated that the CaOx crystals in the L. miyakojimae cotyledons were distributed along lateral veins; however, their distribution was limited to the abaxial side of the procambium. The CaOx crystals appeared at stage II (seed-filling stage) of seed development, and their number increased in dry seeds. The number of crystals in cotyledons was high during germination, suggesting that CaOx crystals are not degraded for their calcium supply. Evidence for the conservation of CaOx crystals in cotyledons during the L. miyakojimae germination process was also supported by the biochemical measurement of oxalic acid levels.

  1. Spatial and temporal predictions of moose winter distribution.

    PubMed

    Månsson, J; Bunnefeld, N; Andrén, H; Ericsson, G

    2012-10-01

    Herbivores are usually distributed unevenly across the landscape often because of variation in resource availability. We used zero-inflated generalised additive models (to account for data with a high number of zeros) that include georeferences to predict winter distribution of a large herbivore (moose Alces alces). Moose distribution was analysed in relation to forage availability and distance to neighbouring sites. Our results showed that the ability to explain moose distribution indexed by pellet count data at a local scale increased when spatial information (longitude and latitude) was added to the model compared to the model only including food availability. By using the relationship between moose and forage distribution, and the spatial information, we predicted patch choice by moose reasonably well in 2 out of 4 years. However, the distribution of moose was also influenced by weather conditions, as it was most clumped in the year with most snow. In conclusion, our study lends support for a non-linear approach using georeferences for a comprehensive understanding of herbivore distribution at a small scale. This result also indicates that the use of a certain patch by moose not only depends on the selected patch itself but is also influenced by the neighbouring patch and factors at a larger spatial scale, such as moose management influencing the density above moose home range level. The relatively high proportion of unexplained variation suggests that the use of a certain patch is also influenced by other factors such as topography, predation, competition, weather conditions, and wildlife management strategies.

  2. Unleashing spatially distributed ecohydrology modeling using Big Data tools

    NASA Astrophysics Data System (ADS)

    Miles, B.; Idaszak, R.

    2015-12-01

    Physically based spatially distributed ecohydrology models are useful for answering science and management questions related to the hydrology and biogeochemistry of prairie, savanna, forested, as well as urbanized ecosystems. However, these models can produce hundreds of gigabytes of spatial output for a single model run over decadal time scales when run at regional spatial scales and moderate spatial resolutions (~100-km2+ at 30-m spatial resolution) or when run for small watersheds at high spatial resolutions (~1-km2 at 3-m spatial resolution). Numerical data formats such as HDF5 can store arbitrarily large datasets. However even in HPC environments, there are practical limits on the size of single files that can be stored and reliably backed up. Even when such large datasets can be stored, querying and analyzing these data can suffer from poor performance due to memory limitations and I/O bottlenecks, for example on single workstations where memory and bandwidth are limited, or in HPC environments where data are stored separately from computational nodes. The difficulty of storing and analyzing spatial data from ecohydrology models limits our ability to harness these powerful tools. Big Data tools such as distributed databases have the potential to surmount the data storage and analysis challenges inherent to large spatial datasets. Distributed databases solve these problems by storing data close to computational nodes while enabling horizontal scalability and fault tolerance. Here we present the architecture of and preliminary results from PatchDB, a distributed datastore for managing spatial output from the Regional Hydro-Ecological Simulation System (RHESSys). The initial version of PatchDB uses message queueing to asynchronously write RHESSys model output to an Apache Cassandra cluster. Once stored in the cluster, these data can be efficiently queried to quickly produce both spatial visualizations for a particular variable (e.g. maps and animations), as well

  3. 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

  4. 3D measurement for rapid prototyping

    NASA Astrophysics Data System (ADS)

    Albrecht, Peter; Lilienblum, Tilo; Sommerkorn, Gerd; Michaelis, Bernd

    1996-08-01

    Optical 3-D measurement is an interesting approach for rapid prototyping. On one hand it's necessary to get the 3-D data of an object and on the other hand it's necessary to check the manufactured object (quality checking). Optical 3-D measurement can realize both. Classical 3-D measurement procedures based on photogrammetry cause systematic errors at strongly curved surfaces or steps in surfaces. One possibility to reduce these errors is to calculate the 3-D coordinates from several successively taken images. Thus it's possible to get higher spatial resolution and to reduce the systematic errors at 'problem surfaces.' Another possibility is to process the measurement values by neural networks. A modified associative memory smoothes and corrects the calculated 3-D coordinates using a-priori knowledge about the measurement object.

  5. Unbiased estimators for spatial distribution functions of classical fluids.

    PubMed

    Adib, Artur B; Jarzynski, Christopher

    2005-01-01

    We use a statistical-mechanical identity closely related to the familiar virial theorem, to derive unbiased estimators for spatial distribution functions of classical fluids. In particular, we obtain estimators for both the fluid density rho(r) in the vicinity of a fixed solute and the pair correlation g(r) of a homogeneous classical fluid. We illustrate the utility of our estimators with numerical examples, which reveal advantages over traditional histogram-based methods of computing such distributions.

  6. 3-D Seismic Interpretation

    NASA Astrophysics Data System (ADS)

    Moore, Gregory F.

    2009-05-01

    This volume is a brief introduction aimed at those who wish to gain a basic and relatively quick understanding of the interpretation of three-dimensional (3-D) seismic reflection data. The book is well written, clearly illustrated, and easy to follow. Enough elementary mathematics are presented for a basic understanding of seismic methods, but more complex mathematical derivations are avoided. References are listed for readers interested in more advanced explanations. After a brief introduction, the book logically begins with a succinct chapter on modern 3-D seismic data acquisition and processing. Standard 3-D acquisition methods are presented, and an appendix expands on more recent acquisition techniques, such as multiple-azimuth and wide-azimuth acquisition. Although this chapter covers the basics of standard time processing quite well, there is only a single sentence about prestack depth imaging, and anisotropic processing is not mentioned at all, even though both techniques are now becoming standard.

  7. Radiochromic 3D Detectors

    NASA Astrophysics Data System (ADS)

    Oldham, Mark

    2015-01-01

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

  8. Validating a spatially distributed hydrological model with soil morphology data

    NASA Astrophysics Data System (ADS)

    Doppler, T.; Honti, M.; Zihlmann, U.; Weisskopf, P.; Stamm, C.

    2013-10-01

    Spatially distributed hydrological models are popular tools in hydrology and they are claimed to be useful to support management decisions. Despite the high spatial resolution of the computed variables, calibration and validation is often carried out only on discharge time-series at specific locations due to the lack of spatially distributed reference data. Because of this restriction, the predictive power of these models, with regard to predicted spatial patterns, can usually not be judged. An example of spatial predictions in hydrology is the prediction of saturated areas in agricultural catchments. These areas can be important source areas for the transport of agrochemicals to the stream. We set up a spatially distributed model to predict saturated areas in a 1.2 km2 catchment in Switzerland with moderate topography. Around 40% of the catchment area are artificially drained. We measured weather data, discharge and groundwater levels in 11 piezometers for 1.5 yr. For broadening the spatially distributed data sets that can be used for model calibration and validation, we translated soil morphological data available from soil maps into an estimate of the duration of soil saturation in the soil horizons. We used redox-morphology signs for these estimates. This resulted in a data set with high spatial coverage on which the model predictions were validated. In general, these saturation estimates corresponded well to the measured groundwater levels. We worked with a model that would be applicable for management decisions because of its fast calculation speed and rather low data requirements. We simultaneously calibrated the model to the groundwater levels in the piezometers and discharge. The model was able to reproduce the general hydrological behavior of the catchment in terms of discharge and absolute groundwater levels. However, the accuracy of the groundwater level predictions was not high enough to be used for the prediction of saturated areas. The groundwater

  9. Mechanical Motion Induced by Spatially Distributed Limit-Cycle Oscillators

    NASA Astrophysics Data System (ADS)

    Sakaguchi, Hidetsugu; Mukae, Yuuki

    2017-03-01

    Spatially distributed limited-cycle oscillators are seen in various physical and biological systems. In internal organs, mechanical motions are induced by the stimuli of spatially distributed limit-cycle oscillators. We study several mechanical motions by limit-cycle oscillators using simple model equations. One problem is deformation waves of radius oscillation induced by desynchronized limit-cycle oscillators, which is motivated by peristaltic motion of the small intestine. A resonance-like phenomenon is found in the deformation waves, and particles can be transported by the deformation waves. Another is the beating motion of the heart. The expansion and contraction motion is realized by a spatially synchronized limit-cycle oscillation; however, the strong beating disappears by spiral chaos, which is closely related to serious arrhythmia in the heart.

  10. TACO3D. 3-D Finite Element Heat Transfer Code

    SciTech Connect

    Mason, W.E.

    1992-03-04

    TACO3D is a three-dimensional, finite-element program for heat transfer analysis. An extension of the two-dimensional TACO program, it can perform linear and nonlinear analyses and can be used to solve either transient or steady-state problems. The program accepts time-dependent or temperature-dependent material properties, and materials may be isotropic or orthotropic. A variety of time-dependent and temperature-dependent boundary conditions and loadings are available including temperature, flux, convection, and radiation boundary conditions and internal heat generation. Additional specialized features treat enclosure radiation, bulk nodes, and master/slave internal surface conditions (e.g., contact resistance). Data input via a free-field format is provided. A user subprogram feature allows for any type of functional representation of any independent variable. A profile (bandwidth) minimization option is available. The code is limited to implicit time integration for transient solutions. TACO3D has no general mesh generation capability. Rows of evenly-spaced nodes and rows of sequential elements may be generated, but the program relies on separate mesh generators for complex zoning. TACO3D does not have the ability to calculate view factors internally. Graphical representation of data in the form of time history and spatial plots is provided through links to the POSTACO and GRAPE postprocessor codes.

  11. Bootstrapping 3D fermions

    DOE PAGES

    Iliesiu, Luca; Kos, Filip; Poland, David; ...

    2016-03-17

    We study the conformal bootstrap for a 4-point function of fermions <ψψψψ> in 3D. We first introduce an embedding formalism for 3D spinors and compute the conformal blocks appearing in fermion 4-point functions. Using these results, we find general bounds on the dimensions of operators appearing in the ψ × ψ OPE, and also on the central charge CT. We observe features in our bounds that coincide with scaling dimensions in the GrossNeveu models at large N. Finally, we also speculate that other features could coincide with a fermionic CFT containing no relevant scalar operators.

  12. Bootstrapping 3D fermions

    SciTech Connect

    Iliesiu, Luca; Kos, Filip; Poland, David; Pufu, Silviu S.; Simmons-Duffin, David; Yacoby, Ran

    2016-03-17

    We study the conformal bootstrap for a 4-point function of fermions <ψψψψ> in 3D. We first introduce an embedding formalism for 3D spinors and compute the conformal blocks appearing in fermion 4-point functions. Using these results, we find general bounds on the dimensions of operators appearing in the ψ × ψ OPE, and also on the central charge CT. We observe features in our bounds that coincide with scaling dimensions in the GrossNeveu models at large N. Finally, we also speculate that other features could coincide with a fermionic CFT containing no relevant scalar operators.

  13. Spatial distribution of pipe collapses in Goodwin Creek Watershed, Mississippi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Internal erosion of soil pipes can induce pipe collapses that affect soil erosion process and landform evolution. The objective of this study was to determine the spatial distribution of pipe collapses in agricultural fields of Goodwin Creek watershed. Ground survey was carried out to detect pipe co...

  14. Spatial distribution of glycerophospholipids in the ocular lens.

    PubMed

    Pól, Jaroslav; Vidová, Veronika; Hyötyläinen, Tuulia; Volný, Michael; Novák, Petr; Strohalm, Martin; Kostiainen, Risto; Havlíček, Vladimír; Wiedmer, Susanne K; Holopainen, Juha M

    2011-04-29

    Knowledge of the spatial distribution of lipids in the intraocular lens is important for understanding the physiology and biochemistry of this unique tissue and for gaining a better insight into the mechanisms underlying diseases of the lens. Following our previous study showing the spatial distribution of sphingolipids in the porcine lens, the current study used ultra performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOFMS) to provide the whole lipidome of porcine lens and these studies were supplemented by matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI MSI) of the lens using ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) to determine the spatial distribution of glycerophospholipids. Altogether 172 lipid species were identified with high confidence and their concentration was determined. Sphingomyelins, phosphatidylcholines, and phosphatidylethanolamines were the most abundant lipid classes. We then determined the spatial and concentration-dependent distributions of 20 phosphatidylcholines, 6 phosphatidylethanolamines, and 4 phosphatidic acids. Based on the planar molecular images of the lipids, we report the organization of fiber cell membranes within the ocular lens and suggest roles for these lipids in normal and diseased lenses.

  15. A crucial role for spatial distribution in bacterial quorum sensing

    PubMed Central

    Gao, Meng; Zheng, Huizhen; Ren, Ying; Lou, Ruyun; Wu, Fan; Yu, Weiting; Liu, Xiudong; Ma, Xiaojun

    2016-01-01

    Quorum sensing (QS) is a process that enables bacteria to communicate using secreted signaling molecules, and then makes a population of bacteria to regulate gene expression collectively and control behavior on a community-wide scale. Theoretical studies of efficiency sensing have suggested that both mass-transfer performance in the local environment and the spatial distribution of cells are key factors affecting QS. Here, an experimental model based on hydrogel microcapsules with a three-dimensional structure was established to investigate the influence of the spatial distribution of cells on bacterial QS. Vibrio harveyi cells formed different spatial distributions in the microcapsules, i.e., they formed cell aggregates with different structures and sizes. The cell aggregates displayed stronger QS than did unaggregated cells even when equal numbers of cells were present. Large aggregates (LA) of cells, with a size of approximately 25 μm, restricted many more autoinducers (AIs) than did small aggregates (SA), with a size of approximately 10 μm, thus demonstrating that aggregate size significantly affects QS. These findings provide a powerful demonstration of the fact that the spatial distribution of cells plays a crucial role in bacterial QS. PMID:27698391

  16. Dynamics of strongly coupled spatially distributed logistic equations with delay

    NASA Astrophysics Data System (ADS)

    Kashchenko, I. S.; Kashchenko, S. A.

    2015-04-01

    The dynamics of a system of two logistic delay equations with spatially distributed coupling is studied. The coupling coefficient is assumed to be sufficiently large. Special nonlinear systems of parabolic equations are constructed such that the behavior of their solutions is determined in the first approximation by the dynamical properties of the original system.

  17. Recording the spatial distribution of coherent-radiation intensity

    SciTech Connect

    Zaslavskii, V.Y.; Przhevskii, S.S.; Shalomeeva, N.V.

    1986-01-01

    This paper discusses the feasibility of recording the spatial distribution of laser-radiation intensity, which is proven theoretically and confirmed by experiment. The authors consider the influence of the inhomogeneity and the wave front of radiation within the confines of a focusing optical element on the character of the diffracted image of the element.

  18. Spatial distribution read-out system for thermoluminescence sheets

    NASA Technical Reports Server (NTRS)

    Yamamoto, I.; Tomiyama, T.; Imaeda, K.; Ninagawa, K.; Wada, T.; Yamashita, Y.; Misaki, A.

    1985-01-01

    A spatial distribution read-out system of thermoluminescence (TL) sheets is developed. This system consists of high gain image intensifier, a CCD-TV camera, a video image processor and a host computer. This system has been applied to artificial TL sheets (BaSO4:Eu doped) for detecting high energy electromagnetic shower and heavy nuclei tracks.

  19. Spatial Distribution of Glycerophospholipids in the Ocular Lens

    PubMed Central

    Pól, Jaroslav; Vidová, Veronika; Hyötyläinen, Tuulia; Volný, Michael; Novák, Petr; Strohalm, Martin; Kostiainen, Risto; Havlíček, Vladimír; Wiedmer, Susanne K.; Holopainen, Juha M.

    2011-01-01

    Knowledge of the spatial distribution of lipids in the intraocular lens is important for understanding the physiology and biochemistry of this unique tissue and for gaining a better insight into the mechanisms underlying diseases of the lens. Following our previous study showing the spatial distribution of sphingolipids in the porcine lens, the current study used ultra performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOFMS) to provide the whole lipidome of porcine lens and these studies were supplemented by matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI MSI) of the lens using ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) to determine the spatial distribution of glycerophospholipids. Altogether 172 lipid species were identified with high confidence and their concentration was determined. Sphingomyelins, phosphatidylcholines, and phosphatidylethanolamines were the most abundant lipid classes. We then determined the spatial and concentration-dependent distributions of 20 phosphatidylcholines, 6 phosphatidylethanolamines, and 4 phosphatidic acids. Based on the planar molecular images of the lipids, we report the organization of fiber cell membranes within the ocular lens and suggest roles for these lipids in normal and diseased lenses. PMID:21559377

  20. SNL3dFace

    SciTech Connect

    Russ, Trina; Koch, Mark; Koudelka, Melissa; Peters, Ralph; Little, Charles; Boehnen, Chris; Peters, Tanya

    2007-07-20

    This software distribution contains MATLAB and C++ code to enable identity verification using 3D images that may or may not contain a texture component. The code is organized to support system performance testing and system capability demonstration through the proper configuration of the available user interface. Using specific algorithm parameters the face recognition system has been demonstrated to achieve a 96.6% verification rate (Pd) at 0.001 false alarm rate. The system computes robust facial features of a 3D normalized face using Principal Component Analysis (PCA) and Fisher Linear Discriminant Analysis (FLDA). A 3D normalized face is obtained by alighning each face, represented by a set of XYZ coordinated, to a scaled reference face using the Iterative Closest Point (ICP) algorithm. The scaled reference face is then deformed to the input face using an iterative framework with parameters that control the deformed surface regulation an rate of deformation. A variety of options are available to control the information that is encoded by the PCA. Such options include the XYZ coordinates, the difference of each XYZ coordinates from the reference, the Z coordinate, the intensity/texture values, etc. In addition to PCA/FLDA feature projection this software supports feature matching to obtain similarity matrices for performance analysis. In addition, this software supports visualization of the STL, MRD, 2D normalized, and PCA synthetic representations in a 3D environment.

  1. Spatial distribution of metabolites in the human lens.

    PubMed

    Tamara, Semen O; Yanshole, Lyudmila V; Yanshole, Vadim V; Fursova, Anjella Zh; Stepakov, Denis A; Novoselov, Vladimir P; Tsentalovich, Yuri P

    2016-02-01

    Spatial distribution of 34 metabolites along the optical and equatorial axes of the human lens has been determined. For the majority of metabolites, the homogeneous distribution has been observed. That suggests that the rate of the metabolite transformation in the lens is low due to the general metabolic passivity of the lens fiber cells. However, the redox processes are active in the lens; as a result, some metabolites, including antioxidants, demonstrate the "nucleus-depleted" type of distribution, whereas secondary UV filters show the "nucleus-enriched" type. The metabolite concentrations at the lens poles and equator are similar for all metabolites under study. The concentric pattern of the "nucleus-depleted" and "nucleus-enriched" distributions testifies that the metabolite distribution inside the lens is mostly governed by a passive diffusion, relatively free along the fiber cells and retarded in the radial direction across the cells. No significant difference in the metabolite distribution between the normal and cataractous human lenses was found.

  2. Application of a 3D volumetric display for radiation therapy treatment planning I: quality assurance procedures.

    PubMed

    Gong, Xing; Kirk, Michael Collins; Napoli, Josh; Stutsman, Sandy; Zusag, Tom; Khelashvili, Gocha; Chu, James

    2009-07-17

    To design and implement a set of quality assurance tests for an innovative 3D volumetric display for radiation treatment planning applications. A genuine 3D display (Perspecta Spatial 3D, Actuality-Systems Inc., Bedford, MA) has been integrated with the Pinnacle TPS (Philips Medical Systems, Madison WI), for treatment planning. The Perspecta 3D display renders a 25 cm diameter volume that is viewable from any side, floating within a translucent dome. In addition to displaying all 3D data exported from Pinnacle, the system provides a 3D mouse to define beam angles and apertures and to measure distance. The focus of this work is the design and implementation of a quality assurance program for 3D displays and specific 3D planning issues as guided by AAPM Task Group Report 53. A series of acceptance and quality assurance tests have been designed to evaluate the accuracy of CT images, contours, beams, and dose distributions as displayed on Perspecta. Three-dimensional matrices, rulers and phantoms with known spatial dimensions were used to check Perspecta's absolute spatial accuracy. In addition, a system of tests was designed to confirm Perspecta's ability to import and display Pinnacle data consistently. CT scans of phantoms were used to confirm beam field size, divergence, and gantry and couch angular accuracy as displayed on Perspecta. Beam angles were verified through Cartesian coordinate system measurements and by CT scans of phantoms rotated at known angles. Beams designed on Perspecta were exported to Pinnacle and checked for accuracy. Dose at sampled points were checked for consistency with Pinnacle and agreed within 1% or 1 mm. All data exported from Pinnacle to Perspecta was displayed consistently. The 3D spatial display of images, contours, and dose distributions were consistent with Pinnacle display. When measured by the 3D ruler, the distances between any two points calculated using Perspecta agreed with Pinnacle within the measurement error.

  3. Fractal nature of hydrocarbon deposits. 2. Spatial distribution

    SciTech Connect

    Barton, C.C.; Schutter, T.A; Herring, P.R.; Thomas, W.J. ); Scholz, C.H. )

    1991-03-01

    Hydrocarbons are unevenly distributed within reservoirs and are found in patches whose size distribution is a fractal over a wide range of scales. The spatial distribution of the patches is also fractal and this can be used to constrain the design of drilling strategies also defined by a fractal dimension. Fractal distributions are scale independent and are characterized by a power-law scaling exponent termed the fractal dimension. The authors have performed fractal analyses on the spatial distribution of producing and showing wells combined and of dry wells in 1,600-mi{sup 2} portions of the Denver and Powder River basins that were nearly completely drilled on quarter-mile square-grid spacings. They have limited their analyses to wells drilled to single stratigraphic intervals so that the map pattern revealed by drilling is representative of the spatial patchiness of hydrocarbons at depth. The fractal dimensions for the spatial patchiness of hydrocarbons in the two basins are 1.5 and 1.4, respectively. The fractal dimension for the pattern of all wells drilled is 1.8 for both basins, which suggests a drilling strategy with a fractal dimension significantly higher than the dimensions 1.5 and 1.4 sufficient to efficiently and economically explore these reservoirs. In fact, the fractal analysis reveals that the drilling strategy used in these basins approaches a fractal dimension of 2.0, which is equivalent to random drilling with no geologic input. Knowledge of the fractal dimension of a reservoir prior to drilling would provide a basis for selecting and a criterion for halting a drilling strategy for exploration whose fractal dimension closely matches that of the spatial fractal dimension of the reservoir, such a strategy should prove more efficient and economical than current practice.

  4. Venus in 3D

    NASA Technical Reports Server (NTRS)

    Plaut, Jeffrey J.

    1993-01-01

    Stereographic images of the surface of Venus which enable geologists to reconstruct the details of the planet's evolution are discussed. The 120-meter resolution of these 3D images make it possible to construct digital topographic maps from which precise measurements can be made of the heights, depths, slopes, and volumes of geologic structures.

  5. 3D photoacoustic imaging

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

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

  6. Development of a Heterogenic Distributed Environment for Spatial Data Processing Using Cloud Technologies

    NASA Astrophysics Data System (ADS)

    Garov, A. S.; Karachevtseva, I. P.; Matveev, E. V.; Zubarev, A. E.; Florinsky, I. V.

    2016-06-01

    We are developing a unified distributed communication environment for processing of spatial data which integrates web-, desktop- and mobile platforms and combines volunteer computing model and public cloud possibilities. The main idea is to create a flexible working environment for research groups, which may be scaled according to required data volume and computing power, while keeping infrastructure costs at minimum. It is based upon the "single window" principle, which combines data access via geoportal functionality, processing possibilities and communication between researchers. Using an innovative software environment the recently developed planetary information system (http://cartsrv.mexlab.ru/geoportal) will be updated. The new system will provide spatial data processing, analysis and 3D-visualization and will be tested based on freely available Earth remote sensing data as well as Solar system planetary images from various missions. Based on this approach it will be possible to organize the research and representation of results on a new technology level, which provides more possibilities for immediate and direct reuse of research materials, including data, algorithms, methodology, and components. The new software environment is targeted at remote scientific teams, and will provide access to existing spatial distributed information for which we suggest implementation of a user interface as an advanced front-end, e.g., for virtual globe system.

  7. Impact of the spatial laser distribution on photocathode gun operation

    NASA Astrophysics Data System (ADS)

    Zhou, Feng; Brachmann, Axel; Emma, Paul; Gilevich, Sasha; Huang, Zhirong

    2012-09-01

    It is widely believed that a drive laser with uniform temporal and spatial laser profiles is required to generate the lowest emittance beam at the photoinjector. However, for a given 3 ps smooth-Gaussian laser temporal profile, our recent simulations indicate that a truncated-Gaussian laser spatial profile produces an electron beam with smaller emittance. The simulation results are qualitatively confirmed by later analytical calculation, and also confirmed by measurements: emittance reduction of ˜25% was observed at the linac coherent light source (LCLS) injector with a truncated-Gaussian laser spatial profile at the nominal operating bunch charge of 150 pC. There was a significant secondary benefit—laser transmission through the iris for the truncated-Gaussian profile was about twice that compared to the nearly uniform distribution, which significantly loosens the laser power and quantum efficiency requirements for drive laser system and photocathode. Since February 9, 2012, the drive laser with the truncated-Gaussian spatial distribution has been used for LCLS routine user operations and the corresponding free electron laser power is at least the same as the one when using the nearly uniform spatial profile.

  8. A new spatial snow distribution in hydrological models parameterized from observed spatial variability of precipitation.

    NASA Astrophysics Data System (ADS)

    Skaugen, Thomas; Weltzien, Ingunn

    2016-04-01

    The traditional catchment hydrological model with its many free calibration parameters is not a well suited tool for prediction under conditions for which is has not been calibrated. Important tasks for hydrological modelling such as prediction in ungauged basins and assessing hydrological effects of climate change are hence not solved satisfactory. In order to reduce the number of calibration parameters in hydrological models we have introduced a new model which uses a dynamic gamma distribution as the spatial frequency distribution of snow water equivalent (SWE). The parameters are estimated from observed spatial variability of precipitation and the magnitude of accumulation and melting events and are hence not subject to calibration. The relationship between spatial mean and variance of precipitation is found to follow a pattern where decreasing temporal correlation with increasing accumulation or duration of the event leads to a levelling off or even a decrease of the spatial variance. The new model for snow distribution is implemented in the, already parameter parsimonious, DDD (Distance Distribution Dynamics) hydrological model and was tested for 71 Norwegian catchments. We compared the new snow distribution model with the current operational snow distribution model where a fixed, calibrated coefficient of variation parameterizes a log-normal model for snow distribution. Results show that the precision of runoff simulations is equal, but that the new snow distribution model better simulates snow covered area (SCA) when compared with MODIS satellite derived snow cover. In addition, SWE is simulated more realistically in that seasonal snow is melted out and the building up of "snow towers" is prevented and hence spurious trends in SWE.

  9. SPATIALLY RESOLVED H{alpha} MAPS AND SIZES OF 57 STRONGLY STAR-FORMING GALAXIES AT z {approx} 1 FROM 3D-HST: EVIDENCE FOR RAPID INSIDE-OUT ASSEMBLY OF DISK GALAXIES

    SciTech Connect

    Nelson, Erica June; Van Dokkum, Pieter G.; Skelton, Rosalind E.; Bezanson, Rachel; Lundgren, Britt; Brammer, Gabriel; Foerster Schreiber, Natascha; Franx, Marijn; Fumagalli, Mattia; Patel, Shannon; Labbe, Ivo; Rix, Hans-Walter; Da Cunha, Elisabete; Schmidt, Kasper B.; Kriek, Mariska; Quadri, Ryan

    2012-03-10

    We investigate the buildup of galaxies at z {approx} 1 using maps of H{alpha} and stellar continuum emission for a sample of 57 galaxies with rest-frame H{alpha} equivalent widths >100 A in the 3D-HST grism survey. We find that the H{alpha} emission broadly follows the rest-frame R-band light but that it is typically somewhat more extended and clumpy. We quantify the spatial distribution with the half-light radius. The median H{alpha} effective radius r{sub e} (H{alpha}) is 4.2 {+-} 0.1 kpc but the sizes span a large range, from compact objects with r{sub e} (H{alpha}) {approx} 1.0 kpc to extended disks with r{sub e} (H{alpha}) {approx} 15 kpc. Comparing H{alpha} sizes to continuum sizes, we find =1.3 {+-} 0.1 for the full sample. That is, star formation, as traced by H{alpha}, typically occurs out to larger radii than the rest-frame R-band stellar continuum; galaxies are growing their radii and building up from the inside out. This effect appears to be somewhat more pronounced for the largest galaxies. Using the measured H{alpha} sizes, we derive star formation rate surface densities, {Sigma}{sub SFR}. We find that {Sigma}{sub SFR} ranges from {approx}0.05 M{sub Sun} yr{sup -1} kpc{sup -2} for the largest galaxies to {approx}5 M{sub Sun} yr{sup -1} kpc{sup -2} for the smallest galaxies, implying a large range in physical conditions in rapidly star-forming z {approx} 1 galaxies. Finally, we infer that all galaxies in the sample have very high gas mass fractions and stellar mass doubling times <500 Myr. Although other explanations are also possible, a straightforward interpretation is that we are simultaneously witnessing the rapid formation of compact bulges and large disks at z {approx} 1.

  10. 3D current source density imaging based on acoustoelectric effect: a simulation study using unipolar pulses

    PubMed Central

    Yang, Renhuan; Li, Xu; Liu, Jun; He, Bin

    2011-01-01

    It is of importance to image electrical activity and properties of biological tissues. Recently hybrid imaging modality combing ultrasound scanning and source imaging through the acousto-electric (AE) effect has generated considerable interest. Such modality has the potential to provide high spatial resolution current density imaging by utilizing the pressure induced AE resistivity change confined at the ultrasound focus. In this study, we investigate a novel 3-dimensional (3D) ultrasound current source density imaging (UCSDI) approach using unipolar ultrasound pulses. Utilizing specially designed unipolar ultrasound pulses and by combining AE signals associated to the local resistivity changes at the focusing point, we are able to reconstruct the 3D current density distribution with the boundary voltage measurements obtained while performing a 3D ultrasound scan. We have shown in computer simulation that using the present method, it is feasible to image with high spatial resolution an arbitrary 3D current density distribution in an inhomogeneous conductive media. PMID:21628774

  11. Spatial paradigms of lotic diatom distribution: A landscape ecology perspective

    USGS Publications Warehouse

    Passy, S.I.

    2001-01-01

    Spatial distributional patterns of benthic diatoms and their relation to current velocity were investigated in an unshaded cobble-bottom reach of White Creek (Washington County, NY). On 27 August 1999, diatoms were sampled and current velocity and depth were measured on a regular square sampling grid with a grain size of 0.01 m2, interval of 0.5 m, and extent of 16 m2. The relative abundance of the 18 common diatom species enumerated in the 81 samples was subjected to detrended correspondence analysis (DCA). The first axis (DCA1) explained 51% of the variance in diatom data and separated the samples according to current regimes. The spatial autocorrelation of DCA1 sample scores in deposition and erosion regions of White Creek was determined by Moran's I statistic to indicate patch size. In White Creek the patch length of all diatom communities was more than 3.1 m, whereas the patch width was 1 m in the deposition region and 0.5 m in the erosion region. There were 5 dominant diatom taxa, Achnanthes minutissima Ku??tz. et vars, Fragilaria capucina Dezmazie??res et vars, F. crotonensis Kitt., Diatoma vulgaris Bory, and Synedra ulna (Nitz.) Ehr. et vars. The patch length of the dominant species varied from 1 to more than 4.1 m, whereas the patch width, if defined, was 0.5 m. Achnanthes minutissima and F. capucina, the two diatom species with the highest relative abundance, displayed spatially structured patches of low abundance and comparatively random patches of high abundance, suggesting broad scale abiotic control of species performance in low abundance regions and finer scale biotic control of high abundance areas. Another objective of this study was to test the hypothesis that higher current velocities, which generally impede immigration, would increase randomness and complexity (i.e. homogeneity of diatom distributional patterns). The spatial complexity in low versus high velocity transects was determined by calculating the respective fractal dimension (D) of DCA

  12. Improving sample distribution homogeneity in Three-Dimensional Microfluidic Paper-Based Analytical Devices (3D-μPAD) by rational device design.

    PubMed

    Morbioli, Giorgio Gianini; Mazzu-Nascimento, Thiago; Milan, Luis Aparecido; Stockton, Amanda M; Carrilho, Emanuel

    2017-04-12

    Paper-based devices are a portable, user-friendly and affordable technology that is one of the best analytical tools for inexpensive diagnostic devices. Three-dimensional microfluidic paper-based analytical devices (3D-μPADs) are an evolution of single layer devices and they permit effective sample dispersion, individual layer treatment, and multiplex analytical assays. Here, we present the rational design of a wax-printed 3D-μPAD that enables more homogeneous permeation of fluids along the cellulose matrix than other existing designs in the literature. Moreover, we show the importance of the rational design of channels on these devices using glucose oxidase, peroxidase, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) reactions. We present an alternative method for layer stacking using a magnetic apparatus, which facilitates fluidic dispersion and improves the reproducibility of tests performed on 3D-μPADs. We also provide the optimized designs for printing, facilitating further studies using 3D-μPADs.

  13. Spatial Distribution of Flower Color Induced by Interspecific Sexual Interaction

    PubMed Central

    Takahashi, Yuma; Takakura, Koh-ichi; Kawata, Masakado

    2016-01-01

    Understanding the mechanisms shaping the spatiotemporal distribution of species has long been a central concern of ecology and evolutionary biology. Contemporary patterns of plant assemblies suggest that sexual interactions among species, i.e., reproductive interference, lead to the exclusive distributions of closely related species that share pollinators. However, the fitness consequences and the initial ecological/evolutionary responses to reproductive interference remain unclear in nature, since reproductive isolation or allopatric distribution has already been achieved in the natural community. In Japan, three species of blue-eyed grasses (Sisyrinchium) with incomplete reproductive isolation have recently colonized and occur sympatrically. Two of them are monomorphic with white flowers, whereas the other exhibits heritable color polymorphism (white and purple morphs). Here we investigated the effects of the presence of two monomorphic species on the distribution and reproductive success of color morphs. The frequency and reproductive success of white morphs decreased in area where monomorphic species were abundant, while those of purple morphs did not. The rate of hybridization between species was higher in white morphs than in the purple ones. Resource competition and habitat preference seemed not to contribute to the spatial distribution and reproductive success of two morphs. Our results supported that color-dependent reproductive interference determines the distribution of flower color polymorphism in a habitat, implying ecological sorting promoted by pollinator-mediated reproductive interference. Our study helps us to understand the evolution and spatial structure of flower color in a community. PMID:27723785

  14. Characterizing the spatial distribution of microhemorrhages resulting from Traumatic Brain Injury (TBI)

    NASA Astrophysics Data System (ADS)

    Li, Ningzhi; Chou, Yi-Yu; Shiee, Navid; Chan, Leighton; Pham, Dzung L.; Butman, John A.

    2014-03-01

    This study examines the spatial distribution of microhemorrhages defined using susceptibility weighted images (SWI) in 46 patients with Traumatic Brain Injury (TBI) and applying region of interest (ROI) analysis using a brain atlas. SWI and 3D T1-weighted images were acquired on a 3T clinical Siemens scanner. A neuroradiologist reviewed all SWI images and manually labeled all identified microhemorrhages. To characterize the spatial distribution of microhemorrhages in standard Montreal Neurological Institute (MNI) space, the T1-weighted images were nonlinearly registered to the MNI template. This transformation was then applied to the co-registered SWI images and to the microhemorrhage coordinates. The frequencies of microhemorrhages were determined in major structures from ROIs defined in the digital Talairach brain atlas and in white matter tracts defined using a diffusion tensor imaging atlas. A total of 629 microhemorrhages were found with an average of 22±42 (range=1-179) in the 24 positive TBI patients. Microhemorrhages mostly congregated around the periphery of the brain and were fairly symmetrically distributed, although a number were found in the corpus callosum. From Talairach ROI analysis, microhemorrhages were most prevalent in the frontal lobes (65.1%). Restricting the analysis to WM tracts, microhemorrhages were primarily found in the corpus callosum (56.9%).

  15. 3D structured illumination microscopy

    NASA Astrophysics Data System (ADS)

    Dougherty, William M.; Goodwin, Paul C.

    2011-03-01

    Three-dimensional structured illumination microscopy achieves double the lateral and axial resolution of wide-field microscopy, using conventional fluorescent dyes, proteins and sample preparation techniques. A three-dimensional interference-fringe pattern excites the fluorescence, filling in the "missing cone" of the wide field optical transfer function, thereby enabling axial (z) discrimination. The pattern acts as a spatial carrier frequency that mixes with the higher spatial frequency components of the image, which usually succumb to the diffraction limit. The fluorescence image encodes the high frequency content as a down-mixed, moiré-like pattern. A series of images is required, wherein the 3D pattern is shifted and rotated, providing down-mixed data for a system of linear equations. Super-resolution is obtained by solving these equations. The speed with which the image series can be obtained can be a problem for the microscopy of living cells. Challenges include pattern-switching speeds, optical efficiency, wavefront quality and fringe contrast, fringe pitch optimization, and polarization issues. We will review some recent developments in 3D-SIM hardware with the goal of super-resolved z-stacks of motile cells.

  16. Nanofabricated Neural Probes for Dense 3-D Recordings of Brain Activity

    PubMed Central

    2016-01-01

    Computations in brain circuits involve the coordinated activation of large populations of neurons distributed across brain areas. However, monitoring neuronal activity in the brain of intact animals with high temporal and spatial resolution has remained a technological challenge. Here we address this challenge by developing dense, three-dimensional (3-D) electrode arrays for electrophysiology. The 3-D arrays constitute the front-end of a modular and configurable system architecture that enables monitoring neuronal activity with unprecedented scale and resolution. PMID:27766885

  17. Validating a spatially distributed hydrological model with soil morphology data

    NASA Astrophysics Data System (ADS)

    Doppler, T.; Honti, M.; Zihlmann, U.; Weisskopf, P.; Stamm, C.

    2014-09-01

    Spatially distributed models are popular tools in hydrology claimed to be useful to support management decisions. Despite the high spatial resolution of the computed variables, calibration and validation is often carried out only on discharge time series at specific locations due to the lack of spatially distributed reference data. Because of this restriction, the predictive power of these models, with regard to predicted spatial patterns, can usually not be judged. An example of spatial predictions in hydrology is the prediction of saturated areas in agricultural catchments. These areas can be important source areas for inputs of agrochemicals to the stream. We set up a spatially distributed model to predict saturated areas in a 1.2 km2 catchment in Switzerland with moderate topography and artificial drainage. We translated soil morphological data available from soil maps into an estimate of the duration of soil saturation in the soil horizons. This resulted in a data set with high spatial coverage on which the model predictions were validated. In general, these saturation estimates corresponded well to the measured groundwater levels. We worked with a model that would be applicable for management decisions because of its fast calculation speed and rather low data requirements. We simultaneously calibrated the model to observed groundwater levels and discharge. The model was able to reproduce the general hydrological behavior of the catchment in terms of discharge and absolute groundwater levels. However, the the groundwater level predictions were not accurate enough to be used for the prediction of saturated areas. Groundwater level dynamics were not adequately reproduced and the predicted spatial saturation patterns did not correspond to those estimated from the soil map. Our results indicate that an accurate prediction of the groundwater level dynamics of the shallow groundwater in our catchment that is subject to artificial drainage would require a model that

  18. A software tool for 3D dose verification and analysis

    NASA Astrophysics Data System (ADS)

    Sa'd, M. Al; Graham, J.; Liney, G. P.

    2013-06-01

    The main recent developments in radiotherapy have focused on improved treatment techniques in order to generate further significant improvements in patient prognosis. There is now an internationally recognised need to improve 3D verification of highly conformal radiotherapy treatments. This is because of the very high dose gradients used in modern treatment techniques, which can result in a small error in the spatial dose distribution leading to a serious complication. In order to gain the full benefits of using 3D dosimetric technologies (such as gel dosimetry), it is vital to use 3D evaluation methods and algorithms. We present in this paper a software solution that provides a comprehensive 3D dose evaluation and analysis. The software is applied to gel dosimetry, which is based on magnetic resonance imaging (MRI) as a read-out method. The software can also be used to compare any two dose distributions, such as two distributions planned using different methods of treatment planning systems, or different dose calculation algorithms.

  19. Spatial distribution of enzyme activities in the rhizosphere

    NASA Astrophysics Data System (ADS)

    Razavi, Bahar S.; Zarebanadkouki, Mohsen; Blagodatskaya, Evgenia; Kuzyakov, Yakov

    2015-04-01

    The rhizosphere, the tiny zone of soil surrounding roots, certainly represents one of the most dynamic habitat and interfaces on Earth. Activities of enzymes produced by both plant roots and microbes are the primary biological drivers of organic matter decomposition and nutrient cycling. That is why there is an urgent need in spatially explicit methods for the determination of the rhizosphere extension and enzyme distribution. Recently, zymography as a new technique based on diffusion of enzymes through the 1 mm gel plate for analysis has been introduced (Spohn & Kuzyakov, 2013). We developed the zymography technique to visualize the enzyme activities with a higher spatial resolution. For the first time, we aimed at quantitative imaging of enzyme activities as a function of distance from the root tip and the root surface in the soil. We visualized the two dimensional distribution of the activity of three enzymes: β-glucosidase, phosphatase and leucine amino peptidase in the rhizosphere of maize using fluorogenically labelled substrates. Spatial-resolution of fluorescent images was improved by direct application of a substrate saturated membrane to the soil-root system. The newly-developed direct zymography visualized heterogeneity of enzyme activities along the roots. The activity of all enzymes was the highest at the apical parts of individual roots. Across the roots, the enzyme activities were higher at immediate vicinity of the roots (1.5 mm) and gradually decreased towards the bulk soil. Spatial patterns of enzyme activities as a function of distance from the root surface were enzyme specific, with highest extension for phosphatase. We conclude that improved zymography is promising in situ technique to analyze, visualize and quantify spatial distribution of enzyme activities in the rhizosphere hotspots. References Spohn, M., Kuzyakov, Y., 2013. Phosphorus mineralization can be driven by microbial need for carbon. Soil Biology & Biochemistry 61: 69-75

  20. [Spatial distribution of soil animals: a geostatistical approach].

    PubMed

    Gongal'skiĭ, K B; Zaĭtsev, A S; Savin, F A

    2009-01-01

    Spatial distribution is one of the main parameters of populations of soil animals. Spatial soil ecology having been developing during last decades bases animal distribution estimates on the geostatistic approach. A simple principle underlying the latter's methodology is that samples placed close to each other have more similarity than those distantly placed, it is usually called autocorrelation. The principles of basic statistics cannot be applied to autocorrelated data. Apiplying variograms, Mantel test, Moran index, and SADIE statistics enables to reveal the size of clusters of both soil parameters and soil animal aggregations. This direction of investigations quite popular in the western literature is just rarely employed by Russian soil ecologists. Statistically correct procedures allow developing field sampling methodology that is vital in applied studies of soil ecology, namely, in bioindication and ecotoxicology of soils, in the assessment of biological resources in terms of abundance and biomass of soil animals. This methodology has a decisive importance in the development of soil biogeography.

  1. Stellar bars and the spatial distribution of infrared luminosity

    NASA Technical Reports Server (NTRS)

    Devereux, Nicholas

    1987-01-01

    Ground-based 10 micron observations of the central region of over 100 infrared luminous galaxies are presented. A first order estimate of the spatial distribution of infrared emission in galaxies is obtained through a combination of ground-based and Infrared Astronomy Satellite (IRAS) data. The galaxies are nearby and primarily noninteracting, permitting an unbiased investigation of correlations with Hubble type. Approximately 40% of the early-type barred galaxies in this sample are associated with enhanced luminosity in the central (approximately 1 kpc diameter) region. The underlying luminosity source is attributed to both Seyfert and star formation activity. Late-type spirals are different in that the spatial distribution of infrared emission and the infrared luminoisty are not strongly dependent on barred morphology.

  2. Spread of pedigree versus genetic ancestry in spatially distributed populations.

    PubMed

    Kelleher, J; Etheridge, A M; Véber, A; Barton, N H

    2016-04-01

    Ancestral processes are fundamental to modern population genetics and spatial structure has been the subject of intense interest for many years. Despite this interest, almost nothing is known about the distribution of the locations of pedigree or genetic ancestors. Using both spatially continuous and stepping-stone models, we show that the distribution of pedigree ancestors approaches a travelling wave, for which we develop two alternative approximations. The speed and width of the wave are sensitive to the local details of the model. After a short time, genetic ancestors spread far more slowly than pedigree ancestors, ultimately diffusing out with radius ∼ t rather than spreading at constant speed. In contrast to the wave of pedigree ancestors, the spread of genetic ancestry is insensitive to the local details of the models.

  3. Spatially varying color distributions for interactive multilabel segmentation.

    PubMed

    Nieuwenhuis, Claudia; Cremers, Daniel

    2013-05-01

    We propose a method for interactive multilabel segmentation which explicitly takes into account the spatial variation of color distributions. To this end, we estimate a joint distribution over color and spatial location using a generalized Parzen density estimator applied to each user scribble. In this way, we obtain a likelihood for observing certain color values at a spatial coordinate. This likelihood is then incorporated in a Bayesian MAP estimation approach to multiregion segmentation which in turn is optimized using recently developed convex relaxation techniques. These guarantee global optimality for the two-region case (foreground/background) and solutions of bounded optimality for the multiregion case. We show results on the GrabCut benchmark, the recently published Graz benchmark, and on the Berkeley segmentation database which exceed previous approaches such as GrabCut, the Random Walker, Santner's approach, TV-Seg, and interactive graph cuts in accuracy. Our results demonstrate that taking into account the spatial variation of color models leads to drastic improvements for interactive image segmentation.

  4. Spatial and Temporal Patterns of Global Onshore Wind Speed Distribution

    SciTech Connect

    Zhou, Yuyu; Smith, Steven J.

    2013-09-09

    Wind power, a renewable energy source, can play an important role in electrical energy generation. Information regarding wind energy potential is important both for energy related modeling and for decision-making in the policy community. While wind speed datasets with high spatial and temporal resolution are often ultimately used for detailed planning, simpler assumptions are often used in analysis work. An accurate representation of the wind speed frequency distribution is needed in order to properly characterize wind energy potential. Using a power density method, this study estimated global variation in wind parameters as fitted to a Weibull density function using NCEP/CFSR reanalysis data. The estimated Weibull distribution performs well in fitting the time series wind speed data at the global level according to R2, root mean square error, and power density error. The spatial, decadal, and seasonal patterns of wind speed distribution were then evaluated. We also analyzed the potential error in wind power estimation when a commonly assumed Rayleigh distribution (Weibull k = 2) is used. We find that the assumption of the same Weibull parameter across large regions can result in substantial errors. While large-scale wind speed data is often presented in the form of average wind speeds, these results highlight the need to also provide information on the wind speed distribution.

  5. Nuclear signature effect on spatial distribution of molecular harmonic in the presence of spatial inhomogeneous field

    NASA Astrophysics Data System (ADS)

    Feng, Liqiang; Li, Wenliang

    2017-01-01

    Spatial distribution of the molecular harmonic spectra from \\text{H}\\text{2}+ in the presence of inhomogeneous field has been theoretically investigated. It shows that (i) the harmonic intensities from the negative-H nucleus play the dominating role in harmonic emission spectra. (ii) Through the investigations of the nuclear signature effect on the spatial distribution of the molecular harmonic spectra, the differences of the harmonic intensities between the negative-H nucleus and the positive-H nucleus can be enhanced and reduced with the introduction of the higher vibrational state and the heavy nucleus (i.e. \\text{D}2+ ), respectively. The time-frequency analyses of the harmonic spectra, the time-dependent wave function and the electron localization have been shown to explain the harmonic spatial distribution and the electron motion. (iii) Due to the plasmon-resonance-enhancement near the metallic nanostructure, the harmonic cutoff can be remarkably enhanced as the spatial position of the inhomogeneous field moving away from the gap center. The ionization probabilities have been shown to explain the harmonic cutoff extension.

  6. Sampling design for spatially distributed hydrogeologic and environmental processes

    USGS Publications Warehouse

    Christakos, G.; Olea, R.A.

    1992-01-01

    A methodology for the design of sampling networks over space is proposed. The methodology is based on spatial random field representations of nonhomogeneous natural processes, and on optimal spatial estimation techniques. One of the most important results of random field theory for physical sciences is its rationalization of correlations in spatial variability of natural processes. This correlation is extremely important both for interpreting spatially distributed observations and for predictive performance. The extent of site sampling and the types of data to be collected will depend on the relationship of subsurface variability to predictive uncertainty. While hypothesis formulation and initial identification of spatial variability characteristics are based on scientific understanding (such as knowledge of the physics of the underlying phenomena, geological interpretations, intuition and experience), the support offered by field data is statistically modelled. This model is not limited by the geometric nature of sampling and covers a wide range in subsurface uncertainties. A factorization scheme of the sampling error variance is derived, which possesses certain atttactive properties allowing significant savings in computations. By means of this scheme, a practical sampling design procedure providing suitable indices of the sampling error variance is established. These indices can be used by way of multiobjective decision criteria to obtain the best sampling strategy. Neither the actual implementation of the in-situ sampling nor the solution of the large spatial estimation systems of equations are necessary. The required values of the accuracy parameters involved in the network design are derived using reference charts (readily available for various combinations of data configurations and spatial variability parameters) and certain simple yet accurate analytical formulas. Insight is gained by applying the proposed sampling procedure to realistic examples related

  7. Spatial distribution of Serengeti wildebeest in relation to resources

    USGS Publications Warehouse

    Wilmshurst, J.F.; Fryxell, J.M.; Farm, Brian P.; Sinclair, A.R.E.; Henschel, C.P.

    1999-01-01

    We investigated the spatial distribution of radio-marked wildebeest (Connochaetes taurinus) in the Serengeti ecosystem in relation to the distribution of their food resources, comparing patterns in the wet and dry seasons and at local and landscape spatial scales. A mechanistic model of ruminant energy optimization predicted that wildebeest should maximize energy intake on swards 3 cm high and maintain energy balance on swards between 3 and 10 cm high. At the ecosystem scale, wildebeest preferred short and intermediate-height grass of moderate greenness during both the wet and dry seasons. This was consistent with the model prediction which suggests that large-scale movements by wildebeest are motivated, at least partially, by an energy-maximizing strategy. At the local scale, however, wildebeest showed spatial selectivity only on the basis of grass greenness, not on grass height. This differed from model expectations and may have resulted from wildebeest exploiting ephemeral green flushes of grass caused by localized rainfall in their movement radius. According to these results, the influence of other nutritional or behavioural factors on wildebeest distributions is not rejected, yet they suggest the potentially important role of an energy intake maximizing strategy on movement patterns. Our findings show that wildebeest movements are broadly similar to those of other large herbivores that migrate in response to resource gradients.

  8. Spatial uncertainty analysis: Propagation of interpolation errors in spatially distributed models

    USGS Publications Warehouse

    Phillips, D.L.; Marks, D.G.

    1996-01-01

    In simulation modelling, it is desirable to quantify model uncertainties and provide not only point estimates for output variables but confidence intervals as well. Spatially distributed physical and ecological process models are becoming widely used, with runs being made over a grid of points that represent the landscape. This requires input values at each grid point, which often have to be interpolated from irregularly scattered measurement sites, e.g., weather stations. Interpolation introduces spatially varying errors which propagate through the model We extended established uncertainty analysis methods to a spatial domain for quantifying spatial patterns of input variable interpolation errors and how they propagate through a model to affect the uncertainty of the model output. We applied this to a model of potential evapotranspiration (PET) as a demonstration. We modelled PET for three time periods in 1990 as a function of temperature, humidity, and wind on a 10-km grid across the U.S. portion of the Columbia River Basin. Temperature, humidity, and wind speed were interpolated using kriging from 700- 1000 supporting data points. Kriging standard deviations (SD) were used to quantify the spatially varying interpolation uncertainties. For each of 5693 grid points, 100 Monte Carlo simulations were done, using the kriged values of temperature, humidity, and wind, plus random error terms determined by the kriging SDs and the correlations of interpolation errors among the three variables. For the spring season example, kriging SDs averaged 2.6??C for temperature, 8.7% for relative humidity, and 0.38 m s-1 for wind. The resultant PET estimates had coefficients of variation (CVs) ranging from 14% to 27% for the 10-km grid cells. Maps of PET means and CVs showed the spatial patterns of PET with a measure of its uncertainty due to interpolation of the input variables. This methodology should be applicable to a variety of spatially distributed models using interpolated

  9. The impact of including spatially longitudinal heterogeneities of vessel oxygen content and vascular fraction in 3D tumor oxygenation models on predicted radiation sensitivity

    SciTech Connect

    Lagerlöf, Jakob H.; Kindblom, Jon; Bernhardt, Peter

    2014-04-15

    Purpose: Oxygen distribution models have been used to analyze the influences of oxygen tensions on tissue response after radiotherapy. These distributions are often generated assuming constant oxygen tension in the blood vessels. However, as red blood cells progress through the vessels, oxygen is continuously released into the plasma and the surrounding tissue, resulting in longitudinally varying oxygen levels in the blood vessels. In the present study, the authors investigated whether a tumor oxygenation model that incorporated longitudinally varying oxygen levels would provide different predictions of necrotic fractions and radiosensitivity compared to commonly used models with a constant oxygen pressure. Methods: Our models simulated oxygen diffusion based on a Green's function approach and oxygen consumption according to the Michaelis-Menten equation. The authors constructed tumor models with different vascular fractions (VFs), from which they generated depth oxygenation curves and a look-up table of oxygen pressure gradients. The authors evaluated models of spherical tumors of various sizes, from 1 to 10{sup 4} mg. The authors compared the results from a model with constant vessel oxygen (CVO) pressure to those from models with longitudinal variations in oxygen saturation and either a constant VF (CVF) or variable VF (VVF) within the tumor tissue. The authors monitored the necrotic fractions, defined as tumor regions with an oxygen pressure below 1 mmHg. Tumor radiation sensitivity was expressed as D{sub 99,} the homogeneous radiation dose required for a tumor control probability of 0.99. Results: In the CVO saturation model, no necrosis was observed, and decreasing the VF could only decrease the D{sub 99} by up to 10%. Furthermore, the D{sub 99} vs VF dependence was similar for different tumor masses. Compared to the CVO model, the extended CVF and VVF models provided clearly different results, including pronounced effects of VF and tumor size on the necrotic

  10. Effective classification of 3D image data using partitioning methods

    NASA Astrophysics Data System (ADS)

    Megalooikonomou, Vasileios; Pokrajac, Dragoljub; Lazarevic, Aleksandar; Obradovic, Zoran

    2002-03-01

    We propose partitioning-based methods to facilitate the classification of 3-D binary image data sets of regions of interest (ROIs) with highly non-uniform distributions. The first method is based on recursive dynamic partitioning of a 3-D volume into a number of 3-D hyper-rectangles. For each hyper-rectangle, we consider, as a potential attribute, the number of voxels (volume elements) that belong to ROIs. A hyper-rectangle is partitioned only if the corresponding attribute does not have high discriminative power, determined by statistical tests, but it is still sufficiently large for further splitting. The final discriminative hyper-rectangles form new attributes that are further employed in neural network classification models. The second method is based on maximum likelihood employing non-spatial (k-means) and spatial DBSCAN clustering algorithms to estimate the parameters of the underlying distributions. The proposed methods were experimentally evaluated on mixtures of Gaussian distributions, on realistic lesion-deficit data generated by a simulator conforming to a clinical study, and on synthetic fractal data. Both proposed methods have provided good classification on Gaussian mixtures and on realistic data. However, the experimental results on fractal data indicated that the clustering-based methods were only slightly better than random guess, while the recursive partitioning provided significantly better classification accuracy.

  11. 3D Immersive Visualization with Astrophysical Data

    NASA Astrophysics Data System (ADS)

    Kent, Brian R.

    2017-01-01

    We present the refinement of a new 3D immersion technique for astrophysical data visualization.Methodology to create 360 degree spherical panoramas is reviewed. The 3D software package Blender coupled with Python and the Google Spatial Media module are used together to create the final data products. Data can be viewed interactively with a mobile phone or tablet or in a web browser. The technique can apply to different kinds of astronomical data including 3D stellar and galaxy catalogs, images, and planetary maps.

  12. The Rossiter-McLaughlin effect reloaded: Probing the 3D spin-orbit geometry, differential stellar rotation, and the spatially-resolved stellar spectrum of star-planet systems