WorldWideScience

Sample records for 3d computational analysis

  1. Advanced computational tools for 3-D seismic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Barhen, J.; Glover, C.W.; Protopopescu, V.A. [Oak Ridge National Lab., TN (United States)] [and others

    1996-06-01

    The global objective of this effort is to develop advanced computational tools for 3-D seismic analysis, and test the products using a model dataset developed under the joint aegis of the United States` Society of Exploration Geophysicists (SEG) and the European Association of Exploration Geophysicists (EAEG). The goal is to enhance the value to the oil industry of the SEG/EAEG modeling project, carried out with US Department of Energy (DOE) funding in FY` 93-95. The primary objective of the ORNL Center for Engineering Systems Advanced Research (CESAR) is to spearhead the computational innovations techniques that would enable a revolutionary advance in 3-D seismic analysis. The CESAR effort is carried out in collaboration with world-class domain experts from leading universities, and in close coordination with other national laboratories and oil industry partners.

  2. Analysis of 3-D images of dental imprints using computer vision

    Science.gov (United States)

    Aubin, Michele; Cote, Jean; Laurendeau, Denis; Poussart, Denis

    1992-05-01

    This paper addressed two important aspects of dental analysis: (1) location and (2) identification of the types of teeth by means of 3-D image acquisition and segmentation. The 3-D images of both maxillaries are acquired using a wax wafer as support. The interstices between teeth are detected by non-linear filtering of the 3-D and grey-level data. Two operators are presented: one for the detection of the interstices between incisors, canines, and premolars and one for those between molars. Teeth are then identified by mapping the imprint under analysis on the computer model of an 'ideal' imprint. For the mapping to be valid, a set of three reference points is detected on the imprint. Then, the points are put in correspondence with similar points on the model. Two such points are chosen based on a least-squares fit of a second-order polynomial of the 3-D data in the area of canines. This area is of particular interest since the canines show a very characteristic shape and are easily detected on the imprint. The mapping technique is described in detail in the paper as well as pre-processing of the 3-D profiles. Experimental results are presented for different imprints.

  3. Analysis of bite marks in foodstuffs by computer tomography (cone beam CT)--3D reconstruction.

    Science.gov (United States)

    Marques, Jeidson; Musse, Jamilly; Caetano, Catarina; Corte-Real, Francisco; Corte-Real, Ana Teresa

    2013-12-01

    The use of three-dimensional (3D) analysis of forensic evidence is highlighted in comparison with traditional methods. This three-dimensional analysis is based on the registration of the surface from a bitten object. The authors propose to use Cone Beam Computed Tomography (CBCT), which is used in dental practice, in order to study the surface and interior of bitten objects and dental casts of suspects. In this study, CBCT is applied to the analysis of bite marks in foodstuffs, which may be found in a forensic case scenario. 6 different types of foodstuffs were used: chocolate, cheese, apple, chewing gum, pizza and tart (flaky pastry and custard). The food was bitten into and dental casts of the possible suspects were made. The dental casts and bitten objects were registered using an x-ray source and the CBCT equipment iCAT® (Pennsylvania, EUA). The software InVivo5® (Anatomage Inc, EUA) was used to visualize and analyze the tomographic slices and 3D reconstructions of the objects. For each material an estimate of its density was assessed by two methods: HU values and specific gravity. All the used materials were successfully reconstructed as good quality 3D images. The relative densities of the materials in study were compared. Amongst the foodstuffs, the chocolate had the highest density (median value 100.5 HU and 1,36 g/cm(3)), while the pizza showed to have the lowest (median value -775 HU and 0,39 g/cm(3)), on both scales. Through tomographic slices and three-dimensional reconstructions it was possible to perform the metric analysis of the bite marks in all the foodstuffs, except for the pizza. These measurements could also be obtained from the dental casts. The depth of the bite mark was also successfully determined in all the foodstuffs except for the pizza. Cone Beam Computed Tomography has the potential to become an important tool for forensic sciences, namely for the registration and analysis of bite marks in foodstuffs that may be found in a crime

  4. Computer-assisted 3D kinematic analysis of all leg joints in walking insects.

    Directory of Open Access Journals (Sweden)

    John A Bender

    Full Text Available High-speed video can provide fine-scaled analysis of animal behavior. However, extracting behavioral data from video sequences is a time-consuming, tedious, subjective task. These issues are exacerbated where accurate behavioral descriptions require analysis of multiple points in three dimensions. We describe a new computer program written to assist a user in simultaneously extracting three-dimensional kinematics of multiple points on each of an insect's six legs. Digital video of a walking cockroach was collected in grayscale at 500 fps from two synchronized, calibrated cameras. We improved the legs' visibility by painting white dots on the joints, similar to techniques used for digitizing human motion. Compared to manual digitization of 26 points on the legs over a single, 8-second bout of walking (or 106,496 individual 3D points, our software achieved approximately 90% of the accuracy with 10% of the labor. Our experimental design reduced the complexity of the tracking problem by tethering the insect and allowing it to walk in place on a lightly oiled glass surface, but in principle, the algorithms implemented are extensible to free walking. Our software is free and open-source, written in the free language Python and including a graphical user interface for configuration and control. We encourage collaborative enhancements to make this tool both better and widely utilized.

  5. Computer Modelling of 3D Geological Surface

    CERN Document Server

    Kodge, B G

    2011-01-01

    The geological surveying presently uses methods and tools for the computer modeling of 3D-structures of the geographical subsurface and geotechnical characterization as well as the application of geoinformation systems for management and analysis of spatial data, and their cartographic presentation. The objectives of this paper are to present a 3D geological surface model of Latur district in Maharashtra state of India. This study is undertaken through the several processes which are discussed in this paper to generate and visualize the automated 3D geological surface model of a projected area.

  6. Computational Analysis of the Transonic Dynamics Tunnel Using FUN3D

    Energy Technology Data Exchange (ETDEWEB)

    Chwalowski, Pawel; Quon, Eliot; Brynildsen, Scott E.

    2016-01-04

    This paper presents results from an explanatory two-year effort of applying Computational Fluid Dynamics (CFD) to analyze the empty-tunnel flow in the NASA Langley Research Center Transonic Dynamics Tunnel (TDT). The TDT is a continuous-flow, closed circuit, 16- x 16-foot slotted-test-section wind tunnel, with capabilities to use air or heavy gas as a working fluid. In this study, experimental data acquired in the empty tunnel using the R-134a test medium was used to calibrate the computational data. The experimental calibration data includes wall pressures, boundary-layer profiles, and the tunnel centerline Mach number profiles. Subsonic and supersonic flow regimes were considered, focusing on Mach 0.5, 0.7 and Mach 1.1 in the TDT test section. This study discusses the computational domain, boundary conditions, and initial conditions selected in the resulting steady-state analyses using NASA's FUN3D CFD software.

  7. 3-D finite element computation and dynamic modal analysis on ultrasonic vibration systems

    Institute of Scientific and Technical Information of China (English)

    倪金刚; 张学仁; 聂景旭(Department of Jet Propulsion 405; Beijing University of Aeronautics and Astronautics; Beijing 100083; China)

    1996-01-01

    Stress and modal analyses are performed on an ultrasonic vibration system by means of a 3-dimensional finite element computation and dynamic modal analysis code "Algor" The system consists of an edge-cracked specimen linked elastically with one or two amplifying horns which come into resonant longitudinal vibration at 20kHz.Operating principle of the ultrasonic fatigue machines and experimental procedures for ultrasonic fatigue crack growth studies are briefly presented.

  8. Fatigue of multiscale composites with secondary nanoplatelet reinforcement: 3D computational analysis

    DEFF Research Database (Denmark)

    Dai, Gaoming; Mishnaevsky, Leon, Jr.

    2014-01-01

    3D numerical simulations of fatigue damage of multiscale fiber reinforced polymer composites with secondary nanoclay reinforcement are carried out. Macro–micro FE models of the multiscale composites are generated automatically using Python based software. The effect of the nanoclay reinforcement...

  9. Modeling and Analysis of a Lunar Space Reactor with the Computer Code RELAP5-3D/ATHENA

    Energy Technology Data Exchange (ETDEWEB)

    Carbajo, Juan J [ORNL; Qualls, A L [ORNL

    2008-01-01

    The transient analysis 3-dimensional (3-D) computer code RELAP5-3D/ATHENA has been employed to model and analyze a space reactor of 180 kW(thermal), 40 kW (net, electrical) with eight Stirling engines (SEs). Each SE will generate over 6 kWe; the excess power will be needed for the pumps and other power management devices. The reactor will be cooled by NaK (a eutectic mixture of sodium and potassium which is liquid at ambient temperature). This space reactor is intended to be deployed over the surface of the Moon or Mars. The reactor operating life will be 8 to 10 years. The RELAP5-3D/ATHENA code is being developed and maintained by Idaho National Laboratory. The code can employ a variety of coolants in addition to water, the original coolant employed with early versions of the code. The code can also use 3-D volumes and 3-D junctions, thus allowing for more realistic representation of complex geometries. A combination of 3-D and 1-D volumes is employed in this study. The space reactor model consists of a primary loop and two secondary loops connected by two heat exchangers (HXs). Each secondary loop provides heat to four SEs. The primary loop includes the nuclear reactor with the lower and upper plena, the core with 85 fuel pins, and two vertical heat exchangers (HX). The maximum coolant temperature of the primary loop is 900 K. The secondary loops also employ NaK as a coolant at a maximum temperature of 877 K. The SEs heads are at a temperature of 800 K and the cold sinks are at a temperature of ~400 K. Two radiators will be employed to remove heat from the SEs. The SE HXs surrounding the SE heads are of annular design and have been modeled using 3-D volumes. These 3-D models have been used to improve the HX design by optimizing the flows of coolant and maximizing the heat transferred to the SE heads. The transients analyzed include failure of one or more Stirling engines, trip of the reactor pump, and trips of the secondary loop pumps feeding the HXs of the

  10. Parametrizable cameras for 3D computational steering

    NARCIS (Netherlands)

    Mulder, J.D.; Wijk, J.J. van

    1997-01-01

    We present a method for the definition of multiple views in 3D interfaces for computational steering. The method uses the concept of a point-based parametrizable camera object. This concept enables a user to create and configure multiple views on his custom 3D interface in an intuitive graphical man

  11. [Computer-assisted 3D phonetography].

    Science.gov (United States)

    Neuschaefer-Rube, C; Klajman, S

    1996-10-01

    Profiles of fundamental frequency sound pressure levels and voice duration are measured separately in clinical practice. It was the aim of the present study to combine the two examinations, in order to estimate the relationship between pitch, sound pressure level and voice duration and to develop a new computer-assisted graph. A three-dimensional (3D) wireframe phonogram was constructed based on SPL profiles to obtain a general view of the parameters recorded. We have termed this "phonetography". Variable further projections were selected for the analysis of different aspects of parametric relationships. The results in 21 healthy volunteers and 4 patients with hyperfunctional dysphonias demonstrated that there were three typical figures of the 3D phonograms produced, depending on the relationship between voice duration when soft ("piano") compared to loud ("forte"). In one-third of the healthy volunteers, the values of the piano voice duration were greater than those of forte for almost all pitches examined. In two-thirds of the healthy subjects the values of forte voice duration were partly greater, as were those of piano voice duration. All of the patients showed voice duration values greater for forte than for piano. The results of the study demonstrate that the 3D phonogram is a useful tool for obtaining new insights into various relationships of voice parameters.

  12. Analysis of 3D Prints by X-ray Computed Microtomography and Terahertz Pulsed Imaging

    DEFF Research Database (Denmark)

    Markl, Daniel; Zeitler, J Axel; Rasch, Cecilie

    2016-01-01

    PURPOSE: A 3D printer was used to realise compartmental dosage forms containing multiple active pharmaceutical ingredient (API) formulations. This work demonstrates the microstructural characterisation of 3D printed solid dosage forms using X-ray computed microtomography (XμCT) and terahertz pulsed...... imaging (TPI). METHODS: Printing was performed with either polyvinyl alcohol (PVA) or polylactic acid (PLA). The structures were examined by XμCT and TPI. Liquid self-nanoemulsifying drug delivery system (SNEDDS) formulations containing saquinavir and halofantrine were incorporated into the 3D printed...... was characterised by XμCT and TPI on the basis of the computer-aided design (CAD) models of the dosage form (compartmentalised PVA structures were 7.5 ± 0.75% larger than designed; n = 3). CONCLUSIONS: The 3D printer can reproduce specific structures very accurately, whereas the 3D prints can deviate from...

  13. 3D Computer Graphics and Nautical Charts

    OpenAIRE

    Porathe, Thomas

    2011-01-01

    This paper gives an overview of an ongoing project using real-time 3D visualization to display nautical charts in a way used by 3D computer games. By displaying the map in an egocentric perspective the need to make cognitively demanding mental rotations are suggested to be removed, leading to faster decision-making and less errors. Experimental results support this hypothesis. Practical tests with limited success have been performed this year.

  14. Personalized mitral valve closure computation and uncertainty analysis from 3D echocardiography.

    Science.gov (United States)

    Grbic, Sasa; Easley, Thomas F; Mansi, Tommaso; Bloodworth, Charles H; Pierce, Eric L; Voigt, Ingmar; Neumann, Dominik; Krebs, Julian; Yuh, David D; Jensen, Morten O; Comaniciu, Dorin; Yoganathan, Ajit P

    2017-01-01

    Intervention planning is essential for successful Mitral Valve (MV) repair procedures. Finite-element models (FEM) of the MV could be used to achieve this goal, but the translation to the clinical domain is challenging. Many input parameters for the FEM models, such as tissue properties, are not known. In addition, only simplified MV geometry models can be extracted from non-invasive modalities such as echocardiography imaging, lacking major anatomical details such as the complex chordae topology. A traditional approach for FEM computation is to use a simplified model (also known as parachute model) of the chordae topology, which connects the papillary muscle tips to the free-edges and select basal points. Building on the existing parachute model a new and comprehensive MV model was developed that utilizes a novel chordae representation capable of approximating regional connectivity. In addition, a fully automated personalization approach was developed for the chordae rest length, removing the need for tedious manual parameter selection. Based on the MV model extracted during mid-diastole (open MV) the MV geometric configuration at peak systole (closed MV) was computed according to the FEM model. In this work the focus was placed on validating MV closure computation. The method is evaluated on ten in vitro ovine cases, where in addition to echocardiography imaging, high-resolution μCT imaging is available for accurate validation.

  15. 3D face modeling, analysis and recognition

    CERN Document Server

    Daoudi, Mohamed; Veltkamp, Remco

    2013-01-01

    3D Face Modeling, Analysis and Recognition presents methodologies for analyzing shapes of facial surfaces, develops computational tools for analyzing 3D face data, and illustrates them using state-of-the-art applications. The methodologies chosen are based on efficient representations, metrics, comparisons, and classifications of features that are especially relevant in the context of 3D measurements of human faces. These frameworks have a long-term utility in face analysis, taking into account the anticipated improvements in data collection, data storage, processing speeds, and application s

  16. Petrophysical analysis of limestone rocks by nuclear logging and 3D high-resolution X-ray computed microtomography

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, M.F.S. [Nuclear Instrumentation Laboratory, COPPE-PEN, UFRJ, P.O. Box 68509, 21941-972 Rio de Janeiro, RJ (Brazil); Lima, I., E-mail: inaya@lin.ufrj.br [Nuclear Instrumentation Laboratory, COPPE-PEN, UFRJ, P.O. Box 68509, 21941-972 Rio de Janeiro, RJ (Brazil); Department of Mechanical Engineering and Energy, IPRJ-UERJ, Nova Friburgo, RJ (Brazil); Ferrucio, P.L.; Abreu, C.J.; Borghi, L. [Geology Department, Geosciences Institute, Rio de Janeiro Federal University, Rio de Janeiro, RJ (Brazil); Lopes, R.T. [Nuclear Instrumentation Laboratory, COPPE-PEN, UFRJ, P.O. Box 68509, 21941-972 Rio de Janeiro, RJ (Brazil)

    2011-10-01

    This study presents the pore-space system analysis of the 2-ITAB-1-RJ well cores, which were drilled in the Sao Jose do Itaborai Basin, in the state of Rio de Janeiro, Brasil. The analysis presented herein has been developed based on two techniques: nuclear logging and 3D high-resolution X-ray computed microtomography. Nuclear logging has been proven to be the technique that provides better quality and more quantitative information about the porosity using radioactive sources. The Density Gamma Probe and the Neutron Sonde used in this work provide qualitative information about bulk density variations and compensated porosity of the geological formation. The samples obtained from the well cores were analyzed by microtomography. The use of this technique in sedimentary rocks allows quantitative evaluation of pore system and generates high-resolution 3D images ({approx}microns order). The images and data obtained by microtomography were integrated with the response obtained by nuclear logging. The results obtained by these two techniques allow the understanding of the pore-size distribution and connectivity, as well as the porosity values. Both techniques are important and they complement each other.

  17. Quantification of arthritic bone degradation by analysis of 3D micro-computed tomography data

    Science.gov (United States)

    Svensson, Carl-Magnus; Hoffmann, Bianca; Irmler, Ingo M.; Straßburger, Maria; Figge, Marc Thilo; Saluz, Hans Peter

    2017-01-01

    The use of animal models of arthritis is a key component in the evaluation of therapeutic strategies against the human disease rheumatoid arthritis (RA). Here we present quantitative measurements of bone degradation characterised by the cortical bone profile using glucose-6-phosphate isomerase (G6PI) induced arthritis. We applied micro-computed tomography (μCT) during three arthritis experiments and one control experiment to image the metatarsals of the hind paws and to investigate the effect of experimental arthritis on their cortical bone profile. For measurements of the cortical profile we automatically identified slices that are orthogonal to individual metatarsals, thereby making the measurements independent of animal placement in the scanner. We measured the average cortical thickness index (CTI) of the metatarsals, as well as the thickness changes along the metatarsal. In this study we introduced the cortical thickness gradient (CTG) as a new measure and we investigated how arthritis affects this measure. We found that in general both CTI and CTG are able to quantify arthritic progression, whilst CTG was found to be the more sensitive measure. PMID:28290525

  18. Complex anatomy surrounding the left atrial posterior wall: analysis with 3D computed tomography.

    Science.gov (United States)

    Maeda, Shingo; Iesaka, Yoshito; Uno, Kikuya; Otomo, Kiyoshi; Nagata, Yasutoshi; Suzuki, Kenji; Hachiya, Hitoshi; Goya, Masahiko; Takahashi, Atsushi; Fujiwara, Hideomi; Hiraoka, Masayasu; Isobe, Mitsuaki

    2012-01-01

    Few studies have explored the topographic anatomy of the esophagus, posterior wall of the left atrium (LA), or fat pads using multidetector computed tomography (MDCT) to prevent the risk of esophageal injury during atrial fibrillation (AF) ablation. MDCT was performed in 110 consecutive patients with paroxysmal or persistent AF before the ablation procedure to understand the anatomic relationship of the esophagus. Two major types of esophagus routes were demonstrated. Leftward (type A) and rightward (type B) routes were found in 90 and 10% of the patients, respectively. A type A route had a larger mean size of the LA than type B. The fat pad was identifiable at the level of the inferior pulmonary vein in 91% of the patients without any predominance of either type. The thickness of the fat pad was thinner in the patients with a dilated LA (>42 mm) than in those with a normal LA size (≤42 mm) (p = 0.01). The results demonstrated that the majority of cases had a leftward route of the esophagus. There was a close association between the LA dilatation and fat pad thinning. With a dilated LA, the esophagus may become easily susceptible to direct thermal injury during AF ablation. Visualization of the anatomic relationship may contribute to the prevention of the potential risk of an esophageal injury.

  19. SURVEY AND ANALYSIS OF 3D STEGANOGRAPHY

    Directory of Open Access Journals (Sweden)

    K .LAKSHMI

    2011-01-01

    Full Text Available Steganography is the science that involves communicating secret data in an appropriate multimedia carrier, eg., images, audio, and video files. The remarkable growth in computational power, increase in current security approaches and techniques are often used together to ensures security of the secret message. Steganography’s ultimate objectives, which are capacity and invisibility, are the main factors that separate it from related techniques. In this paper we focus on 3D models of steganography and conclude with some review analysis of high capacity data hiding and low-distortion 3D models.

  20. CASTLE3D - A Computer Aided System for Labelling Archaeological Excavations in 3D

    Science.gov (United States)

    Houshiar, H.; Borrmann, D.; Elseberg, J.; Nüchter, A.; Näth, F.; Winkler, S.

    2015-08-01

    Documentation of archaeological excavation sites with conventional methods and tools such as hand drawings, measuring tape and archaeological notes is time consuming. This process is prone to human errors and the quality of the documentation depends on the qualification of the archaeologist on site. Use of modern technology and methods in 3D surveying and 3D robotics facilitate and improve this process. Computer-aided systems and databases improve the documentation quality and increase the speed of data acquisition. 3D laser scanning is the state of the art in modelling archaeological excavation sites, historical sites and even entire cities or landscapes. Modern laser scanners are capable of data acquisition of up to 1 million points per second. This provides a very detailed 3D point cloud of the environment. 3D point clouds and 3D models of an excavation site provide a better representation of the environment for the archaeologist and for documentation. The point cloud can be used both for further studies on the excavation and for the presentation of results. This paper introduces a Computer aided system for labelling archaeological excavations in 3D (CASTLE3D). Consisting of a set of tools for recording and georeferencing the 3D data from an excavation site, CASTLE3D is a novel documentation approach in industrial archaeology. It provides a 2D and 3D visualisation of the data and an easy-to-use interface that enables the archaeologist to select regions of interest and to interact with the data in both representations. The 2D visualisation and a 3D orthogonal view of the data provide cuts of the environment that resemble the traditional hand drawings. The 3D perspective view gives a realistic view of the environment. CASTLE3D is designed as an easy-to-use on-site semantic mapping tool for archaeologists. Each project contains a predefined set of semantic information that can be used to label findings in the data. Multiple regions of interest can be joined under

  1. Practical algorithms for 3D computer graphics

    CERN Document Server

    Ferguson, R Stuart

    2013-01-01

    ""A valuable book to accompany any course that mixes the theory and practice of 3D graphics. The book's web site has many useful programs and code samples.""-Karen Rafferty, Queen's University, Belfast""The topics covered by this book are backed by the OpenFX modeling and animation software. This is a big plus in that it provides a practical perspective and encourages experimentation. … [This] will offer students a more interesting and hands-on learning experience, especially for those wishing to pursue a career in computer game development.""-Naganand Madhavapeddy, GameDeveloper>

  2. Simulation of dynamic behaviour of a digital displacement motor using transient 3d computational fluid dynamics analysis

    DEFF Research Database (Denmark)

    Rømer, Daniel; Johansen, Per; Pedersen, Henrik C.

    2013-01-01

    A fast rotating 1500 rpm radial piston digital displacement motor connected to a 350 bar high pressure manifold is simulated by means of transient 3D CFD analysis of a single pressure chamber. The analysis includes dynamic piston and valve movement, influencing the boundaries of the fluid domain...... the simulation using layering zones as required by the moving fluid boundaries. The effect of cavitation at low pressures is included by implementing a pressure dependent density, based on an effective bulk modulus model. In addition, pressure dependent oil viscosity is included in the analysis. As a result...... of the CFD analysis, the dynamic response of the pressure chamber and valve movement of a digital displacement motor is presented, along with the total efficiency of a multi-chamber motor at full and partial displacement. Simulation predicts that pressure over- and undershoot may be reduced to a few percent...

  3. Reconstruction and analysis of shapes from 3D scans

    NARCIS (Netherlands)

    ter Haar, F.B.

    2009-01-01

    In this thesis we use 3D laser range scans for the acquisition, reconstruction, and analysis of 3D shapes. 3D laser range scanning has proven to be a fast and effective way to capture the surface of an object in a computer. Thousands of depth measurements represent a part of the surface geometry as

  4. Infra Red 3D Computer Mouse

    DEFF Research Database (Denmark)

    Harbo, Anders La-Cour; Stoustrup, Jakob

    2000-01-01

    of bandwidth, the signals are designed by means of the wavelet and the Rudin-Shapiro transforms. This also allows for easy separation of simultaneously made measurements. The measured intensities are converted to an 3D position by a neural net. The principle also applies to other applications, for instance...

  5. 3-D computational model of poly (lactic acid)/halloysite nanocomposites: Predicting elastic properties and stress analysis

    DEFF Research Database (Denmark)

    De Silva, R. T.; Pasbakhsh, Pooria; Goh, K. L.

    2014-01-01

    of nanotubes with fixed aspect ratio and the proposed alternative real-structure based model takes the experimentally observed variations of HNTs sizes, impurities and aspect ratios into account. The requirements of the 3-D HNTs nanocomposite models have been explored by testing idealized, real structure based...... and aspect ratios. Numerical studies were validated with experimental investigations and the developed real-structure based model gave more accurate results than idealized and analytical models. (C) 2014 Elsevier Ltd. All rights reserved....

  6. Computer animation for articulated 3D characters

    NARCIS (Netherlands)

    Kiss, S.

    2002-01-01

    We present a review of the computer animation literature, mainly concentrating on articulated characters and at least some degree of interactivity or real time simulation. Advances in dierent techniques such as key-frame, motion capture (also known as mocap), dynamics, inverse kinematics (IK), contr

  7. Hybrid 3-D rocket trajectory program. Part 1: Formulation and analysis. Part 2: Computer programming and user's instruction. [computerized simulation using three dimensional motion analysis

    Science.gov (United States)

    Huang, L. C. P.; Cook, R. A.

    1973-01-01

    Models utilizing various sub-sets of the six degrees of freedom are used in trajectory simulation. A 3-D model with only linear degrees of freedom is especially attractive, since the coefficients for the angular degrees of freedom are the most difficult to determine and the angular equations are the most time consuming for the computer to evaluate. A computer program is developed that uses three separate subsections to predict trajectories. A launch rail subsection is used until the rocket has left its launcher. The program then switches to a special 3-D section which computes motions in two linear and one angular degrees of freedom. When the rocket trims out, the program switches to the standard, three linear degrees of freedom model.

  8. Automated analysis of 3D echocardiography

    NARCIS (Netherlands)

    Stralen, Marijn van

    2009-01-01

    In this thesis we aim at automating the analysis of 3D echocardiography, mainly targeting the functional analysis of the left ventricle. Manual analysis of these data is cumbersome, time-consuming and is associated with inter-observer and inter-institutional variability. Methods for reconstruction o

  9. 3D finite element computational fracture analysis of an MCTS specimen%MCTS试件的三维有限元计算断裂分析

    Institute of Scientific and Technical Information of China (English)

    李庆芬; 齐桂营; 朱莉; 何水清

    2011-01-01

    为了探讨三维复合型断裂问题,采用ANSYS软件对一种带有倾斜裂纹面的修正紧凑拉剪(MCTS)试件进行了三维断裂有限元分析,并应用修正的虚拟裂纹闭合积分方法(MVCCI),对三维裂纹试件的应力强度因子进行了计算.研究结果表明:该MCTS试件在Ⅰ型、Ⅱ型及Ⅰ+Ⅱ复合型(加载角为45°)加载条件下均产生了Ⅰ+Ⅱ+Ⅲ复合型断裂,实验结果与有限元分析的结果吻合.%The 3D finite element computational fracture analysis of a modified compact tension shear ( MCTS) specimen with an inclined crack plane was presented in this paper by using ANSYS in order to further study a 3D mixed-mode fracture. The stress intensity factors of the 3 D-crack specimen were calculated by the modified virtual crack closure integral (MVCCI) method. Results show that the mixed-mode I + II + HI fracture occurred when the MCTS specimen was subject to mode I, mode II, and mixed-mode I + II loadings (loading angle is 45°). Results of the finite element analysis are in good agreement with the experimental results, suggesting that the numerical analysis in the presented work is reliable.

  10. Automotive Underhood Thermal Management Analysis Using 3-D Coupled Thermal-Hydrodynamic Computer Models: Thermal Radiation Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Pannala, S; D' Azevedo, E; Zacharia, T

    2002-02-26

    The goal of the radiation modeling effort was to develop and implement a radiation algorithm that is fast and accurate for the underhood environment. As part of this CRADA, a net-radiation model was chosen to simulate radiative heat transfer in an underhood of a car. The assumptions (diffuse-gray and uniform radiative properties in each element) reduce the problem tremendously and all the view factors for radiation thermal calculations can be calculated once and for all at the beginning of the simulation. The cost for online integration of heat exchanges due to radiation is found to be less than 15% of the baseline CHAD code and thus very manageable. The off-line view factor calculation is constructed to be very modular and has been completely integrated to read CHAD grid files and the output from this code can be read into the latest version of CHAD. Further integration has to be performed to accomplish the same with STAR-CD. The main outcome of this effort is to obtain a highly scalable and portable simulation capability to model view factors for underhood environment (for e.g. a view factor calculation which took 14 hours on a single processor only took 14 minutes on 64 processors). The code has also been validated using a simple test case where analytical solutions are available. This simulation capability gives underhood designers in the automotive companies the ability to account for thermal radiation - which usually is critical in the underhood environment and also turns out to be one of the most computationally expensive components of underhood simulations. This report starts off with the original work plan as elucidated in the proposal in section B. This is followed by Technical work plan to accomplish the goals of the project in section C. In section D, background to the current work is provided with references to the previous efforts this project leverages on. The results are discussed in section 1E. This report ends with conclusions and future scope of

  11. COMPUTER MODELING IN DEFORM-3D FOR ANALYSIS OF PLASTIC FLOW IN HIGH-SPEED HOT EXTRUSION OF BIMETALLIC FORMATIVE PARTS OF DIE TOOLING

    Directory of Open Access Journals (Sweden)

    I. V. Kachanov

    2015-01-01

    Full Text Available The modern development of industrial production is closely connected with the use of science-based and high technologies to ensure competitiveness of the manufactured products on the world market. There is also much tension around an energy- and resource saving problem which can be solved while introducing new technological processes and  creation of new materials that provide productivity increase through automation and improvement of tool life. Development and implementation of such technologies are rather often considered as time-consuming processes  which are connected with complex calculations and experimental investigations. Implementation of a simulation modelling for materials processing using modern software products serves an alternative to experimental and theoretical methods of research.The aim of this paper is to compare experimental results while obtaining bimetallic samples of a forming tool through the method of speed hot extrusion and the results obtained with the help of computer simulation using DEFORM-3D package and a finite element method. Comparative analysis of plastic flow of real and model samples has shown that the obtained models provide high-quality and reliable picture of plastic flow during high-speed hot extrusion. Modeling in DEFORM-3D make it possible to eliminate complex calculations and significantly reduce a number of experimental studies while developing new technological processes.

  12. 3D motion analysis via energy minimization

    Energy Technology Data Exchange (ETDEWEB)

    Wedel, Andreas

    2009-10-16

    This work deals with 3D motion analysis from stereo image sequences for driver assistance systems. It consists of two parts: the estimation of motion from the image data and the segmentation of moving objects in the input images. The content can be summarized with the technical term machine visual kinesthesia, the sensation or perception and cognition of motion. In the first three chapters, the importance of motion information is discussed for driver assistance systems, for machine vision in general, and for the estimation of ego motion. The next two chapters delineate on motion perception, analyzing the apparent movement of pixels in image sequences for both a monocular and binocular camera setup. Then, the obtained motion information is used to segment moving objects in the input video. Thus, one can clearly identify the thread from analyzing the input images to describing the input images by means of stationary and moving objects. Finally, I present possibilities for future applications based on the contents of this thesis. Previous work in each case is presented in the respective chapters. Although the overarching issue of motion estimation from image sequences is related to practice, there is nothing as practical as a good theory (Kurt Lewin). Several problems in computer vision are formulated as intricate energy minimization problems. In this thesis, motion analysis in image sequences is thoroughly investigated, showing that splitting an original complex problem into simplified sub-problems yields improved accuracy, increased robustness, and a clear and accessible approach to state-of-the-art motion estimation techniques. In Chapter 4, optical flow is considered. Optical flow is commonly estimated by minimizing the combined energy, consisting of a data term and a smoothness term. These two parts are decoupled, yielding a novel and iterative approach to optical flow. The derived Refinement Optical Flow framework is a clear and straight-forward approach to

  13. 3D computer modeling of sitting working place.

    Science.gov (United States)

    Mijović, B; Ujević, D; Skoko, M; Baksa, S

    2002-12-01

    Ergonomic contribution to designing and modeling of sitting working place by use of a computer and computer programs have been presented in this work. The influences of modeling working places on regular posture of a man/woman during work have been reconsidered, so that consumption of energy and fatigue are brought down to a minimum. For that purpose a computer program has been made which with input data on various kinds of work, sex and height of a worker determines the optimal ergonomic parameters during the modeling of a sitting working place. By computer visualisation the values of angle of spine curving have been calculated, the manipulation angle of arms and legs for three anthropometric heights of workers (160 cm, 175 cm and 190 cm). The dimensions of manipulative body space have been established by computerised 3D anthropometric analysis of movement as for example, reach of arms, legs, head, back etc positions. In this process the dimensions of machine and working space surrounding it in respect to optimal utilisation have been put in accordance with the anthropometric size of a man/woman.

  14. Axial stent strut angle influences wall shear stress after stent implantation: analysis using 3D computational fluid dynamics models of stent foreshortening

    Directory of Open Access Journals (Sweden)

    Warltier David C

    2005-10-01

    Full Text Available Abstract Introduction The success of vascular stents in the restoration of blood flow is limited by restenosis. Recent data generated from computational fluid dynamics (CFD models suggest that the vascular geometry created by an implanted stent causes local alterations in wall shear stress (WSS that are associated with neointimal hyperplasia (NH. Foreshortening is a potential limitation of stent design that may affect stent performance and the rate of restenosis. The angle created between axially aligned stent struts and the principal direction of blood flow varies with the degree to which the stent foreshortens after implantation. Methods In the current investigation, we tested the hypothesis that stent foreshortening adversely influences the distribution of WSS and WSS gradients using time-dependent 3D CFD simulations of normal arteries based on canine coronary artery measurements of diameter and blood flow. WSS and WSS gradients were calculated using conventional techniques in ideal (16 mm and progressively foreshortened (14 and 12 mm stented computational vessels. Results Stent foreshortening increased the intrastrut area of the luminal surface exposed to low WSS and elevated spatial WSS gradients. Progressive degrees of stent foreshortening were also associated with strut misalignment relative to the direction of blood flow as indicated by analysis of near-wall velocity vectors. Conclusion The current results suggest that foreshortening may predispose the stented vessel to a higher risk of neointimal hyperplasia.

  15. 3D object-oriented image analysis in 3D geophysical modelling

    DEFF Research Database (Denmark)

    Fadel, I.; van der Meijde, M.; Kerle, N.

    2015-01-01

    Non-uniqueness of satellite gravity interpretation has traditionally been reduced by using a priori information from seismic tomography models. This reduction in the non-uniqueness has been based on velocity-density conversion formulas or user interpretation of the 3D subsurface structures (objects......) based on the seismic tomography models and then forward modelling these objects. However, this form of object-based approach has been done without a standardized methodology on how to extract the subsurface structures from the 3D models. In this research, a 3D object-oriented image analysis (3D OOA......) approach was implemented to extract the 3D subsurface structures from geophysical data. The approach was applied on a 3D shear wave seismic tomography model of the central part of the East African Rift System. Subsequently, the extracted 3D objects from the tomography model were reconstructed in the 3D...

  16. Advanced 3-D analysis, client-server systems, and cloud computing-Integration of cardiovascular imaging data into clinical workflows of transcatheter aortic valve replacement.

    Science.gov (United States)

    Schoenhagen, Paul; Zimmermann, Mathis; Falkner, Juergen

    2013-06-01

    Degenerative aortic stenosis is highly prevalent in the aging populations of industrialized countries and is associated with poor prognosis. Surgical valve replacement has been the only established treatment with documented improvement of long-term outcome. However, many of the older patients with aortic stenosis (AS) are high-risk or ineligible for surgery. For these patients, transcatheter aortic valve replacement (TAVR) has emerged as a treatment alternative. The TAVR procedure is characterized by a lack of visualization of the operative field. Therefore, pre- and intra-procedural imaging is critical for patient selection, pre-procedural planning, and intra-operative decision-making. Incremental to conventional angiography and 2-D echocardiography, multidetector computed tomography (CT) has assumed an important role before TAVR. The analysis of 3-D CT data requires extensive post-processing during direct interaction with the dataset, using advance analysis software. Organization and storage of the data according to complex clinical workflows and sharing of image information have become a critical part of these novel treatment approaches. Optimally, the data are integrated into a comprehensive image data file accessible to multiple groups of practitioners across the hospital. This creates new challenges for data management requiring a complex IT infrastructure, spanning across multiple locations, but is increasingly achieved with client-server solutions and private cloud technology. This article describes the challenges and opportunities created by the increased amount of patient-specific imaging data in the context of TAVR.

  17. 3D measurement system based on computer-generated gratings

    Science.gov (United States)

    Zhu, Yongjian; Pan, Weiqing; Luo, Yanliang

    2010-08-01

    A new kind of 3D measurement system has been developed to achieve the 3D profile of complex object. The principle of measurement system is based on the triangular measurement of digital fringe projection, and the fringes are fully generated from computer. Thus the computer-generated four fringes form the data source of phase-shifting 3D profilometry. The hardware of system includes the computer, video camera, projector, image grabber, and VGA board with two ports (one port links to the screen, another to the projector). The software of system consists of grating projection module, image grabbing module, phase reconstructing module and 3D display module. A software-based synchronizing method between grating projection and image capture is proposed. As for the nonlinear error of captured fringes, a compensating method is introduced based on the pixel-to-pixel gray correction. At the same time, a least square phase unwrapping is used to solve the problem of phase reconstruction by using the combination of Log Modulation Amplitude and Phase Derivative Variance (LMAPDV) as weight. The system adopts an algorithm from Matlab Tool Box for camera calibration. The 3D measurement system has an accuracy of 0.05mm. The execution time of system is 3~5s for one-time measurement.

  18. A new computer program for topological, visual analysis of 3D particle configurations based on visual representation of radial distribution function peaks as bonds

    CERN Document Server

    Metere, Alfredo; Dzugutov, Mikhail

    2015-01-01

    We present a new program able to perform unique visual analysis on generic particle systems: PASYVAT (PArticle SYstem Visual Analysis Tool). More specifically, it can perform a selection of multiple interparticle distance ranges from a radial distribution function (RDF) plot and display them in 3D as bonds. This software can be used with any data set representing a system of particles in 3D. In this manuscript the reader will find a description of the program and its internal structure, with emphasis on its applicability in the study of certain particle configurations, obtained from classical molecular dynamics simulation in condensed matter physics.

  19. Reconstruction and Analysis of Shapes from 3D Scans

    NARCIS (Netherlands)

    Haar, F.B. ter

    2009-01-01

    In this thesis, we measure 3D shapes with the use of 3D laser technology, a recent technology that combines physics, mathematics, and computer science to acquire the surface geometry of 3D shapes in the computer. We use this surface geometry to fully reconstruct real world shapes as computer models,

  20. 3D Printing device adaptable to Computer Numerical Control (CNC)

    OpenAIRE

    Gardan, Julien; DANESI, Frédéric; Roucoules, Lionel; Schneider, A

    2014-01-01

    This article presents the development of a 3D printing device for the additive manufacturing adapted to a CNC machining. The application involves the integration of a specific printing head. Additive manufacturing technology is most commonly used for modeling, prototyping, tooling through an exclusive machine or 3D printer. A global review and analysis of technologies show the additive manufacturing presents little independent solutions [6][9]. The problem studied especially the additive manu...

  1. 3D artefact for concurrent scale calibration in Computed Tomography

    DEFF Research Database (Denmark)

    Stolfi, Alessandro; De Chiffre, Leonardo

    2016-01-01

    A novel artefact for calibration of the scale in 3D X-ray Computed Tomography (CT) is presented. The artefact comprises a carbon fibre tubular structure on which a number of reference ruby spheres are glued. The artefact is positioned and scanned together with the workpiece inside the CT scanner ...

  2. NASA's 3D Flight Computer for Space Applications

    Science.gov (United States)

    Alkalai, Leon

    2000-01-01

    The New Millennium Program (NMP) Integrated Product Development Team (IPDT) for Microelectronics Systems was planning to validate a newly developed 3D Flight Computer system on its first deep-space flight, DS1, launched in October 1998. This computer, developed in the 1995-97 time frame, contains many new computer technologies previously never used in deep-space systems. They include: advanced 3D packaging architecture for future low-mass and low-volume avionics systems; high-density 3D packaged chip-stacks for both volatile and non-volatile mass memory: 400 Mbytes of local DRAM memory, and 128 Mbytes of Flash memory; high-bandwidth Peripheral Component Interface (Per) local-bus with a bridge to VME; high-bandwidth (20 Mbps) fiber-optic serial bus; and other attributes, such as standard support for Design for Testability (DFT). Even though this computer system did not complete on time for delivery to the DS1 project, it was an important development along a technology roadmap towards highly integrated and highly miniaturized avionics systems for deep-space applications. This continued technology development is now being performed by NASA's Deep Space System Development Program (also known as X2000) and within JPL's Center for Integrated Space Microsystems (CISM).

  3. Computer Graphics Teaching Support using X3D: Extensible 3D Graphics for Web Authors

    OpenAIRE

    Brutzman, Don

    2008-01-01

    X3D is the ISO-standard scene-graph language for interactive 3D graphics on the Web. A new course is available for teaching the fundamentals of 3D graphics using Extensible 3D (X3D). Resources include a detailed textbook, an authoring tool, hundreds of example scenes, and detailed slidesets covering each chapter. The published book is commercially available, while all other course-module resources are provided online free under open-source licenses. Numerous other commercial and o...

  4. 3-D analysis of grain selection process

    Science.gov (United States)

    Arao, Tomoka; Esaka, Hisao; Shinozuka, Kei

    2012-07-01

    It is known that the grain selection plays an important role in the manufacturing process for turbine blades. There are some analytical or numerical models to treat the grain selection. However, the detailed mechanism of grain selection in 3-D is still uncertain. Therefore, an experimental research work using Al-Cu alloy has been carried out in order to understand the grain selection in 3-D.A mold made by Al2O3 was heated to 600 °C ( = liquids temperature of the alloy) and was set on a water-colded copper chill plate. Molten Al-20 wt%Cu alloy was cast into the mold and unidirectional solidified ingot was prepared. The size of ingot was approximately phi25×65H mm. To obtain the thermal history, 4 thermocouples were placed in the mold. It is confirmed that the alloy solidified unidirectionally from bottom to top. Solidified structure on a longitudinal cross section was observed and unidirectional solidification up to 40 mm was ensured. EBSD analysis has been performed on horizontal cross section at an interval of ca.200 μm. These observations were carried out 7-5 mm from the bottom surface. Crystallographic orientation of primary Al phase and size of solidified grains were characterized. A large solidified grain, the crystallographic orientation of which is approximately along heat flow direction, is observed near the lowest cross section. The area of grain decreased as solidification proceeded. On the other hand, it is found that the area of grain increased.

  5. SAMA: A Method for 3D Morphological Analysis.

    Science.gov (United States)

    Paulose, Tessie; Montévil, Maël; Speroni, Lucia; Cerruti, Florent; Sonnenschein, Carlos; Soto, Ana M

    2016-01-01

    Three-dimensional (3D) culture models are critical tools for understanding tissue morphogenesis. A key requirement for their analysis is the ability to reconstruct the tissue into computational models that allow quantitative evaluation of the formed structures. Here, we present Software for Automated Morphological Analysis (SAMA), a method by which epithelial structures grown in 3D cultures can be imaged, reconstructed and analyzed with minimum human intervention. SAMA allows quantitative analysis of key features of epithelial morphogenesis such as ductal elongation, branching and lumen formation that distinguish different hormonal treatments. SAMA is a user-friendly set of customized macros operated via FIJI (http://fiji.sc/Fiji), an open-source image analysis platform in combination with a set of functions in R (http://www.r-project.org/), an open-source program for statistical analysis. SAMA enables a rapid, exhaustive and quantitative 3D analysis of the shape of a population of structures in a 3D image. SAMA is cross-platform, licensed under the GPLv3 and available at http://montevil.theobio.org/content/sama.

  6. Descriptor Based Analysis of Digital 3D Shapes

    DEFF Research Database (Denmark)

    Welnicka, Katarzyna

    challenges. One such challenge, which is addressed in this thesis, is to develop computational methods for classifying shapes which are in agreement with the human way of understanding and classifying shapes. In this dissertation we first present a shape descriptor based on the process of diffusion......Analysis and processing of 3D digital shapes is a significant research area with numerous medical, industrial, and entertainment applications which has gained enormously in importance as optical scanning modalities have started to make acquired 3D geometry commonplace. The area holds many......, in conjunction with the method of Reeb graphs for skeletonization, it is an effective tool for generating scale dependent skeletons of shapes represented as 3D triangle meshes. The second part of the thesis aims at capturing the style phenomenon. The style of an object is easily recognized by humans...

  7. Skeleton-Sectional Structural Analysis for 3D Printing

    Institute of Scientific and Technical Information of China (English)

    Wen-Peng Xu; Wei Li; Li-Gang Liu

    2016-01-01

    3D printing has become popular and has been widely used in various applications in recent years. More and more home users have motivation to design their own models and then fabricate them using 3D printers. However, the printed objects may have some structural or stress defects as the users may be lack of knowledge on stress analysis on 3D models. In this paper, we present an approach to help users analyze a model’s structural strength while designing its shape. We adopt sectional structural analysis instead of conventional FEM (Finite Element Method) analysis which is computationally expensive. Based on sectional structural analysis, our approach imports skeletons to assist in integrating mesh designing, strength computing and mesh correction well. Skeletons can also guide sections building and load calculation for analysis. For weak regions with high stress over a threshold value in the model from analysis result, our system corrects them by scaling the corresponding bones of skeleton so as to make these regions stiff enough. A number of experiments have demonstrated the applicability and practicability of our approach.

  8. 3D analysis of craniofacial growth and tooth eruption

    DEFF Research Database (Denmark)

    Kreiborg, Sven

    The 9th International Congress on Cleft Palate and Related Craniofacial Anomalies, 3D analysis, craniofacial growth, tooth eruption......The 9th International Congress on Cleft Palate and Related Craniofacial Anomalies, 3D analysis, craniofacial growth, tooth eruption...

  9. Dynamic 3D computed tomography scanner for vascular imaging

    Science.gov (United States)

    Lee, Mark K.; Holdsworth, David W.; Fenster, Aaron

    2000-04-01

    A 3D dynamic computed-tomography (CT) scanner was developed for imaging objects undergoing periodic motion. The scanner system has high spatial and sufficient temporal resolution to produce quantitative tomographic/volume images of objects such as excised arterial samples perfused under physiological pressure conditions and enables the measurements of the local dynamic elastic modulus (Edyn) of the arteries in the axial and longitudinal directions. The system was comprised of a high resolution modified x-ray image intensifier (XRII) based computed tomographic system and a computer-controlled cardiac flow simulator. A standard NTSC CCD camera with a macro lens was coupled to the electro-optically zoomed XRII to acquire dynamic volumetric images. Through prospective cardiac gating and computer synchronized control, a time-resolved sequence of 20 mm thick high resolution volume images of porcine aortic specimens during one simulated cardiac cycle were obtained. Performance evaluation of the scanners illustrated that tomographic images can be obtained with resolution as high as 3.2 mm-1 with only a 9% decrease in the resolution for objects moving at velocities of 1 cm/s in 2D mode and static spatial resolution of 3.55 mm-1 with only a 14% decrease in the resolution in 3D mode for objects moving at a velocity of 10 cm/s. Application of the system for imaging of intact excised arterial specimens under simulated physiological flow/pressure conditions enabled measurements of the Edyn of the arteries with a precision of +/- kPa for the 3D scanner. Evaluation of the Edyn in the axial and longitudinal direction produced values of 428 +/- 35 kPa and 728 +/- 71 kPa, demonstrating the isotropic and homogeneous viscoelastic nature of the vascular specimens. These values obtained from the Dynamic CT systems were not statistically different (p less than 0.05) from the values obtained by standard uniaxial tensile testing and volumetric measurements.

  10. TECHNICAL ANALYSIS OF REMOTE 3D VISUALIZATION ON MOBILE DEVICES

    OpenAIRE

    Ms. U. S. Junghare; Dr.V.M.Thakare; Dharaskar, R. V.; S. S. Sherekar

    2012-01-01

    Considering the limitations of mobile devices like low bandwidth, less computation power, minimumstorage capacity etc it is not possible to store whole data for 3D visualization on mobile devices.Therefore to minimize the load of mobile devices there is use of server in case of remote 3D visualizationon mobile devices (clients). For 3D visualization on mobile devices various techniques are used at serverside as well as at mobile side for different purpose. Some techniques directly provides 3D...

  11. 3D face analysis for demographic biometrics

    Energy Technology Data Exchange (ETDEWEB)

    Tokola, Ryan A [ORNL; Mikkilineni, Aravind K [ORNL; Boehnen, Chris Bensing [ORNL

    2015-01-01

    Despite being increasingly easy to acquire, 3D data is rarely used for face-based biometrics applications beyond identification. Recent work in image-based demographic biometrics has enjoyed much success, but these approaches suffer from the well-known limitations of 2D representations, particularly variations in illumination, texture, and pose, as well as a fundamental inability to describe 3D shape. This paper shows that simple 3D shape features in a face-based coordinate system are capable of representing many biometric attributes without problem-specific models or specialized domain knowledge. The same feature vector achieves impressive results for problems as diverse as age estimation, gender classification, and race classification.

  12. Computing Radiative Transfer in a 3D Medium

    Science.gov (United States)

    Von Allmen, Paul; Lee, Seungwon

    2012-01-01

    A package of software computes the time-dependent propagation of a narrow laser beam in an arbitrary three- dimensional (3D) medium with absorption and scattering, using the transient-discrete-ordinates method and a direct integration method. Unlike prior software that utilizes a Monte Carlo method, this software enables simulation at very small signal-to-noise ratios. The ability to simulate propagation of a narrow laser beam in a 3D medium is an improvement over other discrete-ordinate software. Unlike other direct-integration software, this software is not limited to simulation of propagation of thermal radiation with broad angular spread in three dimensions or of a laser pulse with narrow angular spread in two dimensions. Uses for this software include (1) computing scattering of a pulsed laser beam on a material having given elastic scattering and absorption profiles, and (2) evaluating concepts for laser-based instruments for sensing oceanic turbulence and related measurements of oceanic mixed-layer depths. With suitable augmentation, this software could be used to compute radiative transfer in ultrasound imaging in biological tissues, radiative transfer in the upper Earth crust for oil exploration, and propagation of laser pulses in telecommunication applications.

  13. Extended gray level co-occurrence matrix computation for 3D image volume

    Science.gov (United States)

    Salih, Nurulazirah M.; Dewi, Dyah Ekashanti Octorina

    2017-02-01

    Gray Level Co-occurrence Matrix (GLCM) is one of the main techniques for texture analysis that has been widely used in many applications. Conventional GLCMs usually focus on two-dimensional (2D) image texture analysis only. However, a three-dimensional (3D) image volume requires specific texture analysis computation. In this paper, an extended 2D to 3D GLCM approach based on the concept of multiple 2D plane positions and pixel orientation directions in the 3D environment is proposed. The algorithm was implemented by breaking down the 3D image volume into 2D slices based on five different plane positions (coordinate axes and oblique axes) resulting in 13 independent directions, then calculating the GLCMs. The resulted GLCMs were averaged to obtain normalized values, then the 3D texture features were calculated. A preliminary examination was performed on a 3D image volume (64 x 64 x 64 voxels). Our analysis confirmed that the proposed technique is capable of extracting the 3D texture features from the extended GLCMs approach. It is a simple and comprehensive technique that can contribute to the 3D image analysis.

  14. Multifractal modelling and 3D lacunarity analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hanen, Akkari, E-mail: bettaieb.hanen@topnet.t [Laboratoire de biophysique, TIM, Faculte de Medecine (Tunisia); Imen, Bhouri, E-mail: bhouri_imen@yahoo.f [Unite de recherche ondelettes et multifractals, Faculte des sciences (Tunisia); Asma, Ben Abdallah, E-mail: asma.babdallah@cristal.rnu.t [Laboratoire de biophysique, TIM, Faculte de Medecine (Tunisia); Patrick, Dubois, E-mail: pdubois@chru-lille.f [INSERM, U 703, Lille (France); Hedi, Bedoui Mohamed, E-mail: medhedi.bedoui@fmm.rnu.t [Laboratoire de biophysique, TIM, Faculte de Medecine (Tunisia)

    2009-09-28

    This study presents a comparative evaluation of lacunarity of 3D grey level models with different types of inhomogeneity. A new method based on the 'Relative Differential Box Counting' was developed to estimate the lacunarity features of grey level volumes. To validate our method, we generated a set of 3D grey level multifractal models with random, anisotropic and hierarchical properties. Our method gives a lacunarity measurement correlated with the theoretical one and allows a better model classification compared with a classical approach.

  15. Effect of coordinate rotation on 3D molecular descriptors computed by DragonX

    CERN Document Server

    Hechinger, Manuel

    2012-01-01

    Quantitative structure-property relations (QSPR) employing descriptors derived from the 3D molecular structure are frequently applied for property prediction in various fields of research. In particular, DragonX is one of the most widely used software packages for descriptor calculation. The reliability of 3D molecular descriptors computed by DragonX has lately been investigated, thereby focusing on the effect of computational methods used for molecular structure optimization on the accuracy of the resulting molecular descriptors. The present contribution extends the analysis to a more intrinsic problem of DragonX descriptor evaluation resulting from the sensitivity of the computed 3D descriptors on the coordinate system used for molecule description. Evaluating several 3D descriptors for converged molecular structures rotated around all 3 spatial axes (affine coordinate transformations) yields systematically varying descriptor values. Since this unphysical behavior severely affects the descriptor reliability...

  16. 3D ultrasound computer tomography: update from a clinical study

    Science.gov (United States)

    Hopp, T.; Zapf, M.; Kretzek, E.; Henrich, J.; Tukalo, A.; Gemmeke, H.; Kaiser, C.; Knaudt, J.; Ruiter, N. V.

    2016-04-01

    Ultrasound Computer Tomography (USCT) is a promising new imaging method for breast cancer diagnosis. We developed a 3D USCT system and tested it in a pilot study with encouraging results: 3D USCT was able to depict two carcinomas, which were present in contrast enhanced MRI volumes serving as ground truth. To overcome severe differences in the breast shape, an image registration was applied. We analyzed the correlation between average sound speed in the breast and the breast density estimated from segmented MRIs and found a positive correlation with R=0.70. Based on the results of the pilot study we now carry out a successive clinical study with 200 patients. For this we integrated our reconstruction methods and image post-processing into a comprehensive workflow. It includes a dedicated DICOM viewer for interactive assessment of fused USCT images. A new preview mode now allows intuitive and faster patient positioning. We updated the USCT system to decrease the data acquisition time by approximately factor two and to increase the penetration depth of the breast into the USCT aperture by 1 cm. Furthermore the compute-intensive reflectivity reconstruction was considerably accelerated, now allowing a sub-millimeter volume reconstruction in approximately 16 minutes. The updates made it possible to successfully image first patients in our ongoing clinical study.

  17. Ground truth evaluation of computer vision based 3D reconstruction of synthesized and real plant images

    DEFF Research Database (Denmark)

    Nielsen, Michael; Andersen, Hans Jørgen; Slaughter, David

    2007-01-01

    There is an increasing interest in using 3D computer vision in precision agriculture. This calls for better quantitative evaluation and understanding of computer vision methods. This paper proposes a test framework using ray traced crop scenes that allows in-depth analysis of algorithm performance...

  18. Computational Modelling of Piston Ring Dynamics in 3D

    Directory of Open Access Journals (Sweden)

    Dlugoš Jozef

    2014-12-01

    Full Text Available Advanced computational models of a piston assembly based on the level of virtual prototypes require a detailed description of piston ring behaviour. Considering these requirements, the piston rings operate in regimes that cannot, in general, be simplified into an axisymmetric model. The piston and the cylinder liner do not have a perfect round shape, mainly due to machining tolerances and external thermo-mechanical loads. If the ring cannot follow the liner deformations, a local loss of contact occurs resulting in blow-by and increased consumption of lubricant oil in the engine. Current computational models are unable to implement such effects. The paper focuses on the development of a flexible 3D piston ring model based on the Timoshenko beam theory using the multibody system (MBS. The MBS model is compared to the finite element method (FEM solution.

  19. An Approach to Computer Modeling of Geological Faults in 3D and an Application

    Institute of Scientific and Technical Information of China (English)

    ZHU Liang-feng; HE Zheng; PAN Xin; WU Xin-cai

    2006-01-01

    3D geological modeling, one of the most important applications in geosciences of 3D GIS, forms the basis and is a prerequisite for visualized representation and analysis of 3D geological data. Computer modeling of geological faults in 3D is currently a topical research area. Structural modeling techniques of complex geological entities containing reverse faults are discussed and a series of approaches are proposed. The geological concepts involved in computer modeling and visualization of geological fault in 3D are explained, the type of data of geological faults based on geological exploration is analyzed, and a normative database format for geological faults is designed. Two kinds of modeling approaches for faults are compared: a modeling technique of faults based on stratum recovery and a modeling technique of faults based on interpolation in subareas. A novel approach, called the Unified Modeling Technique for stratum and fault, is presented to solve the puzzling problems of reverse faults, syn-sedimentary faults and faults terminated within geological models. A case study of a fault model of bed rock in the Beijing Olympic Green District is presented in order to show the practical result of this method. The principle and the process of computer modeling of geological faults in 3D are discussed and a series of applied technical proposals established. It strengthens our profound comprehension of geological phenomena and the modeling approach, and establishes the basic techniques of 3D geological modeling for practical applications in the field of geosciences.

  20. Computational approaches to 3D modeling of RNA

    Energy Technology Data Exchange (ETDEWEB)

    Laing, Christian; Schlick, Tamar, E-mail: schlick@nyu.ed [Department of Chemistry and Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, NY 10012 (United States)

    2010-07-21

    Many exciting discoveries have recently revealed the versatility of RNA and its importance in a variety of functions within the cell. Since the structural features of RNA are of major importance to their biological function, there is much interest in predicting RNA structure, either in free form or in interaction with various ligands, including proteins, metabolites and other molecules. In recent years, an increasing number of researchers have developed novel RNA algorithms for predicting RNA secondary and tertiary structures. In this review, we describe current experimental and computational advances and discuss recent ideas that are transforming the traditional view of RNA folding. To evaluate the performance of the most recent RNA 3D folding algorithms, we provide a comparative study in order to test the performance of available 3D structure prediction algorithms for an RNA data set of 43 structures of various lengths and motifs. We find that the algorithms vary widely in terms of prediction quality across different RNA lengths and topologies; most predictions have very large root mean square deviations from the experimental structure. We conclude by outlining some suggestions for future RNA folding research. (topical review)

  1. Computational model of mesenchymal migration in 3D under chemotaxis.

    Science.gov (United States)

    Ribeiro, F O; Gómez-Benito, M J; Folgado, J; Fernandes, P R; García-Aznar, J M

    2017-01-01

    Cell chemotaxis is an important characteristic of cellular migration, which takes part in crucial aspects of life and development. In this work, we propose a novel in silico model of mesenchymal 3D migration with competing protrusions under a chemotactic gradient. Based on recent experimental observations, we identify three main stages that can regulate mesenchymal chemotaxis: chemosensing, dendritic protrusion dynamics and cell-matrix interactions. Therefore, each of these features is considered as a different module of the main regulatory computational algorithm. The numerical model was particularized for the case of fibroblast chemotaxis under a PDGF-bb gradient. Fibroblasts migration was simulated embedded in two different 3D matrices - collagen and fibrin - and under several PDGF-bb concentrations. Validation of the model results was provided through qualitative and quantitative comparison with in vitro studies. Our numerical predictions of cell trajectories and speeds were within the measured in vitro ranges in both collagen and fibrin matrices. Although in fibrin, the migration speed of fibroblasts is very low, because fibrin is a stiffer and more entangling matrix. Testing PDGF-bb concentrations, we noticed that an increment of this factor produces a speed increment. At 1 ng mL(-1) a speed peak is reached after which the migration speed diminishes again. Moreover, we observed that fibrin exerts a dampening behavior on migration, significantly affecting the migration efficiency.

  2. Glasses for 3D ultrasound computer tomography: phase compensation

    Science.gov (United States)

    Zapf, M.; Hopp, T.; Ruiter, N. V.

    2016-03-01

    Ultrasound Computer Tomography (USCT), developed at KIT, is a promising new imaging system for breast cancer diagnosis, and was successfully tested in a pilot study. The 3D USCT II prototype consists of several hundreds of ultrasound (US) transducers on a semi-ellipsoidal aperture. Spherical waves are sequentially emitted by individual transducers and received in parallel by many transducers. Reflectivity volumes are reconstructed by synthetic aperture focusing (SAFT). However, straight forward SAFT imaging leads to blurred images due to system imperfections. We present an extension of a previously proposed approach to enhance the images. This approach includes additional a priori information and system characteristics. Now spatial phase compensation was included. The approach was evaluated with a simulation and clinical data sets. An increase in the image quality was observed and quantitatively measured by SNR and other metrics.

  3. Computational and methodological developments towards 3D full waveform inversion

    Science.gov (United States)

    Etienne, V.; Virieux, J.; Hu, G.; Jia, Y.; Operto, S.

    2010-12-01

    Full waveform inversion (FWI) is one of the most promising techniques for seismic imaging. It relies on a formalism taking into account every piece of information contained in the seismic data as opposed to more classical techniques such as travel time tomography. As a result, FWI is a high resolution imaging process able to reach a spatial accuracy equal to half a wavelength. FWI is based on a local optimization scheme and therefore the main limitation concerns the starting model which has to be closed enough to the real one in order to converge to the global minimum. Another counterpart of FWI is the required computational resources when considering models and frequencies of interest. The task becomes even more tremendous when one tends to perform the inversion using the elastic equation instead of using the acoustic approximation. This is the reason why until recently most studies were limited to 2D cases. In the last few years, due to the increase of the available computational power, FWI has focused a lot of interests and continuous efforts towards inversion of 3D models, leading to remarkable applications up to the continental scale. We investigate the computational burden induced by FWI in 3D elastic media and propose some strategic features leading to the reduction of the numerical cost while providing a great flexibility in the inversion parametrization. First, in order to release the memory requirements, we developed our FWI algorithm in the frequency domain and take benefit of the wave-number redundancy in the seismic data to process a quite reduced number of frequencies. To do so, we extract frequency solutions from time marching techniques which are efficient for 3D structures. Moreover, this frequency approach permits a multi-resolution strategy by proceeding from low to high frequencies: the final model at one frequency is used as the starting model for the next frequency. This procedure overcomes partially the non-linear behavior of the inversion

  4. Protein 3D structure computed from evolutionary sequence variation.

    Directory of Open Access Journals (Sweden)

    Debora S Marks

    Full Text Available The evolutionary trajectory of a protein through sequence space is constrained by its function. Collections of sequence homologs record the outcomes of millions of evolutionary experiments in which the protein evolves according to these constraints. Deciphering the evolutionary record held in these sequences and exploiting it for predictive and engineering purposes presents a formidable challenge. The potential benefit of solving this challenge is amplified by the advent of inexpensive high-throughput genomic sequencing.In this paper we ask whether we can infer evolutionary constraints from a set of sequence homologs of a protein. The challenge is to distinguish true co-evolution couplings from the noisy set of observed correlations. We address this challenge using a maximum entropy model of the protein sequence, constrained by the statistics of the multiple sequence alignment, to infer residue pair couplings. Surprisingly, we find that the strength of these inferred couplings is an excellent predictor of residue-residue proximity in folded structures. Indeed, the top-scoring residue couplings are sufficiently accurate and well-distributed to define the 3D protein fold with remarkable accuracy.We quantify this observation by computing, from sequence alone, all-atom 3D structures of fifteen test proteins from different fold classes, ranging in size from 50 to 260 residues, including a G-protein coupled receptor. These blinded inferences are de novo, i.e., they do not use homology modeling or sequence-similar fragments from known structures. The co-evolution signals provide sufficient information to determine accurate 3D protein structure to 2.7-4.8 Å C(α-RMSD error relative to the observed structure, over at least two-thirds of the protein (method called EVfold, details at http://EVfold.org. This discovery provides insight into essential interactions constraining protein evolution and will facilitate a comprehensive survey of the universe of

  5. Computational analysis for antimicrobial active pyrano[2,3-d]pyrimidine derivatives on the basis of theoretical and experimental ground

    Directory of Open Access Journals (Sweden)

    Ajmal R. Bhat

    2016-06-01

    Full Text Available Annulated pyrano[2,3-d]pyrimidine derivatives were synthesized with methoxy, hydroxyl, nitrile and bromine substituents in its skeleton and correlated by electronic effect of substituents on the magnitude of antimicrobial activity. The different electron donating and electron withdrawing substituents of the pyrano[2,3-d]pyrimidine derivatives exerted positive influence on its antimicrobial activity against some Gram positive and Gram negative bacteria such as, Bacillus cereus, Staphylococcus aureus, Klebsiella pneumonia, Pseudomonas aureus and Escherichia coli, respectively. Antibacterial screening revealed that the presence of heteroaryl, cyano and amino groups on pyrano[2,3-d]pyrimidine skeleton increases its penetrating power on bacterial cell wall and becomes more biologically active. All the pyrano[2,3-d]pyrimidine derivatives were characterized by IR, 1H NMR, 13C NMR and mass spectra.

  6. 3D Vectorial Time Domain Computational Integrated Photonics

    Energy Technology Data Exchange (ETDEWEB)

    Kallman, J S; Bond, T C; Koning, J M; Stowell, M L

    2007-02-16

    The design of integrated photonic structures poses considerable challenges. 3D-Time-Domain design tools are fundamental in enabling technologies such as all-optical logic, photonic bandgap sensors, THz imaging, and fast radiation diagnostics. Such technologies are essential to LLNL and WFO sponsors for a broad range of applications: encryption for communications and surveillance sensors (NSA, NAI and IDIV/PAT); high density optical interconnects for high-performance computing (ASCI); high-bandwidth instrumentation for NIF diagnostics; micro-sensor development for weapon miniaturization within the Stockpile Stewardship and DNT programs; and applications within HSO for CBNP detection devices. While there exist a number of photonics simulation tools on the market, they primarily model devices of interest to the communications industry. We saw the need to extend our previous software to match the Laboratory's unique emerging needs. These include modeling novel material effects (such as those of radiation induced carrier concentrations on refractive index) and device configurations (RadTracker bulk optics with radiation induced details, Optical Logic edge emitting lasers with lateral optical inputs). In addition we foresaw significant advantages to expanding our own internal simulation codes: parallel supercomputing could be incorporated from the start, and the simulation source code would be accessible for modification and extension. This work addressed Engineering's Simulation Technology Focus Area, specifically photonics. Problems addressed from the Engineering roadmap of the time included modeling the Auston switch (an important THz source/receiver), modeling Vertical Cavity Surface Emitting Lasers (VCSELs, which had been envisioned as part of fast radiation sensors), and multi-scale modeling of optical systems (for a variety of applications). We proposed to develop novel techniques to numerically solve the 3D multi-scale propagation problem for both the

  7. 3D Precision Analysis of Interactive Computer-guided Implantology%数字化导板用于牙种植的三维精度分析

    Institute of Scientific and Technical Information of China (English)

    何女; 钱江; 赵佳佳; 翁丽华; 泮海松

    2015-01-01

    Objective: The purpose of this study was to investigate the clinical value of computer-guided digital template in implantology. Methods: From 2011 July to 2012 June, twenty-four implants of five patients were selected to measure the deviation between planned implants and actual implants by pre- and post-operative CBCT images. Patients accepted the CBCT scanning before the operation. A recently developed interactive 3D CT software program was applied to use raw data (DICOM files) from the CT scan to display reformatted CT images for the inspection of the bony anatomy of the alveo-lar ridges. The CT scan data obtained from the software can be used to produce sterolithographic models for 3D visualiza-tion of planning complex implantology. All patients had the CBCT scanning again after operation to get the 3D data of the actual implants. Results:Twenty-four implants were all obtained in ideal physiological positions. The deviation of the site, the depth and the axial angle of the three-dimensional direction was (0.22±0.07) mm, (0.17±0.08) mm, and (0.65±0.19) ° respectively. Conclusion: The oral digital template can accurately transfer the preoperative design, and avoid to damage the important anatomical structure of jaw bones, and obtain the satisfactory denture restoration.%目的:评估应用以修复为导向的数字化导板进行种植牙手术后,种植体在颌骨内的实际位置与软件模拟位置的误差,探讨数字化导板的临床应用价值。方法:2011-07—2012-06期间于诸暨市人民医院口腔种植中心进行数字化导板种植牙手术者,患者术前拍摄口腔锥形束CT(CBCT),获取DICOM格式的CT数据后制作数字化种植导板,完成种植手术后再次拍摄CBCT,获取实际种植体在颌骨内的具体三维位置。选取其中5例患者24枚种植体进行术前、术后精度比较。根据手术前后2次数据,在医学牙种植设计软件中进行三维重建,比较种植体实际位置

  8. Weight prediction of broiler chickens using 3D computer vision

    DEFF Research Database (Denmark)

    Mortensen, Anders Krogh; Lisouski, Pavel; Ahrendt, Peter

    2016-01-01

    a platform weigher which may also include ill birds. In the current study, a fully-automatic 3D camera-based weighing system for broilers have been developed and evaluated in a commercial production environment. Specifically, a low-cost 3D camera (Kinect) that directly returned a depth image was employed...

  9. The development of a 3D risk analysis method.

    Science.gov (United States)

    I, Yet-Pole; Cheng, Te-Lung

    2008-05-01

    Much attention has been paid to the quantitative risk analysis (QRA) research in recent years due to more and more severe disasters that have happened in the process industries. Owing to its calculation complexity, very few software, such as SAFETI, can really make the risk presentation meet the practice requirements. However, the traditional risk presentation method, like the individual risk contour in SAFETI, is mainly based on the consequence analysis results of dispersion modeling, which usually assumes that the vapor cloud disperses over a constant ground roughness on a flat terrain with no obstructions and concentration fluctuations, which is quite different from the real situations of a chemical process plant. All these models usually over-predict the hazardous regions in order to maintain their conservativeness, which also increases the uncertainty of the simulation results. On the other hand, a more rigorous model such as the computational fluid dynamics (CFD) model can resolve the previous limitations; however, it cannot resolve the complexity of risk calculations. In this research, a conceptual three-dimensional (3D) risk calculation method was proposed via the combination of results of a series of CFD simulations with some post-processing procedures to obtain the 3D individual risk iso-surfaces. It is believed that such technique will not only be limited to risk analysis at ground level, but also be extended into aerial, submarine, or space risk analyses in the near future.

  10. Computer-aided diagnosis of mass-like lesion in breast MRI: differential analysis of the 3-D morphology between benign and malignant tumors.

    Science.gov (United States)

    Huang, Yan-Hao; Chang, Yeun-Chung; Huang, Chiun-Sheng; Wu, Tsung-Ju; Chen, Jeon-Hor; Chang, Ruey-Feng

    2013-12-01

    This study aimed to evaluate the value of using 3-D breast MRI morphologic features to differentiate benign and malignant breast lesions. The 3-D morphological features extracted from breast MRI were used to analyze the malignant likelihood of tumor from ninety-five solid breast masses (44 benign and 51 malignant) of 82 patients. Each mass-like lesion was examined with regards to three categories of morphologic features, including texture-based gray-level co-occurrence matrix (GLCM) feature, shape, and ellipsoid fitting features. For obtaining a robust combination of features from different categories, the biserial correlation coefficient (|r(pb)|)≧0.4 was used as the feature selection criterion. Receiver operating characteristic (ROC) curve was used to evaluate performance and Student's t-test to verify the classification accuracy. The combination of the selected 3-D morphological features, including conventional compactness, radius, spiculation, surface ratio, volume covering ratio, number of inside angular regions, sum of number of inside and outside angular regions, showed an accuracy of 88.42% (84/95), sensitivity of 88.24% (45/51), and specificity of 88.64% (39/44), respectively. The AZ value was 0.8926 for these seven combined morphological features. In conclusion, 3-D MR morphological features specified by GLCM, tumor shape and ellipsoid fitting were useful for differentiating benign and malignant breast masses.

  11. 3D joint dynamics analysis of healthy children's gait

    OpenAIRE

    SAMSON, William; DESROCHES, Guillaume; Cheze, Laurence; Dumas, Raphaël

    2009-01-01

    The 3D joint moments and 2D joint powers have been largely explored in the literature of healthy children's gait, in particular to compare them with pathologic subjects' gait. However, no study reported on 3D joint power in children which could be due to the difficulties in interpreting the results. Recently, the analysis of the 3D angle between the joint moment and the joint angular velocity vectors has been proposed in order to help 3D joint power interpretation. Our hypothesis is that this...

  12. Point Cluster Analysis Using a 3D Voronoi Diagram with Applications in Point Cloud Segmentation

    Directory of Open Access Journals (Sweden)

    Shen Ying

    2015-08-01

    Full Text Available Three-dimensional (3D point analysis and visualization is one of the most effective methods of point cluster detection and segmentation in geospatial datasets. However, serious scattering and clotting characteristics interfere with the visual detection of 3D point clusters. To overcome this problem, this study proposes the use of 3D Voronoi diagrams to analyze and visualize 3D points instead of the original data item. The proposed algorithm computes the cluster of 3D points by applying a set of 3D Voronoi cells to describe and quantify 3D points. The decompositions of point cloud of 3D models are guided by the 3D Voronoi cell parameters. The parameter values are mapped from the Voronoi cells to 3D points to show the spatial pattern and relationships; thus, a 3D point cluster pattern can be highlighted and easily recognized. To capture different cluster patterns, continuous progressive clusters and segmentations are tested. The 3D spatial relationship is shown to facilitate cluster detection. Furthermore, the generated segmentations of real 3D data cases are exploited to demonstrate the feasibility of our approach in detecting different spatial clusters for continuous point cloud segmentation.

  13. Design for scalability in 3D computer graphics architectures

    DEFF Research Database (Denmark)

    Holten-Lund, Hans Erik

    2002-01-01

    been developed. Hybris is a prototype rendering architeture which can be tailored to many specific 3D graphics applications and implemented in various ways. Parallel software implementations for both single and multi-processor Windows 2000 system have been demonstrated. Working hardware/software...... codesign implementations of Hybris for standard-cell based ASIC (simulated) and FPGA technologies have been demonstrated, using manual co-synthesis for translation of a Virtual Prototyping architecture specification written in C into both optimized C source for software and into to a synthesizable VHDL...... specification for hardware implementation. A flexible VRML 97 3D scene graph engine with a Java interface and C++ interface has been implemented to allow flexible integration of the rendering technology into Java and C++ applications. A 3D medical visualization workstation prototype (3D-Med) is examined...

  14. Uncertainty Analysis of RELAP5-3D

    Energy Technology Data Exchange (ETDEWEB)

    Alexandra E Gertman; Dr. George L Mesina

    2012-07-01

    As world-wide energy consumption continues to increase, so does the demand for the use of alternative energy sources, such as Nuclear Energy. Nuclear Power Plants currently supply over 370 gigawatts of electricity, and more than 60 new nuclear reactors have been commissioned by 15 different countries. The primary concern for Nuclear Power Plant operation and lisencing has been safety. The safety of the operation of Nuclear Power Plants is no simple matter- it involves the training of operators, design of the reactor, as well as equipment and design upgrades throughout the lifetime of the reactor, etc. To safely design, operate, and understand nuclear power plants, industry and government alike have relied upon the use of best-estimate simulation codes, which allow for an accurate model of any given plant to be created with well-defined margins of safety. The most widely used of these best-estimate simulation codes in the Nuclear Power industry is RELAP5-3D. Our project focused on improving the modeling capabilities of RELAP5-3D by developing uncertainty estimates for its calculations. This work involved analyzing high, medium, and low ranked phenomena from an INL PIRT on a small break Loss-Of-Coolant Accident as wall as an analysis of a large break Loss-Of- Coolant Accident. Statistical analyses were performed using correlation coefficients. To perform the studies, computer programs were written that modify a template RELAP5 input deck to produce one deck for each combination of key input parameters. Python scripting enabled the running of the generated input files with RELAP5-3D on INL’s massively parallel cluster system. Data from the studies was collected and analyzed with SAS. A summary of the results of our studies are presented.

  15. Software-based geometry operations for 3D computer graphics

    NARCIS (Netherlands)

    Sima, M.; Iancu, D.; Glossner, J.; Schulte, M.; Mamidi, S.

    2006-01-01

    In order to support a broad dynamic range and a high degree of precision, many of 3D renderings fundamental algorithms have been traditionally performed in floating-point. However, fixed-point data representation is preferable over floatingpoint representation in graphics applications on embedded de

  16. A Computer Vision Method for 3D Reconstruction of Curves-Marked Free-Form Surfaces

    Institute of Scientific and Technical Information of China (English)

    Xiong Hanwei; Zhang Xiangwei

    2001-01-01

    Visual method is now broadly used in reverse engineering for 3D reconstruction. Thetraditional computer vision methods are feature-based, i.e., they require that the objects must revealfeatures owing to geometry or textures. For textureless free-form surfaces, dense feature points areadded artificially. In this paper, a new method is put forward combining computer vision with CAGD.The surface is subdivided into N-side Gregory patches using marked curves, and a stereo algorithm isused to reconstruct the curves. Then, the cross boundary tangent vector is computed throughreflectance analysis. At last, the whole surface can be reconstructed by jointing these patches withG1 continuity.

  17. Generalized Method of Variational Analysis for 3-D Flow

    Institute of Scientific and Technical Information of China (English)

    兰伟仁; 黄思训; 项杰

    2004-01-01

    The generalized method of variational analysis (GMVA) suggested for 2-D wind observations by Huang et al. is extended to 3-D cases. Just as in 2-D cases, the regularization idea is applied. But due to the complexity of the 3-D cases, the vertical vorticity is taken as a stable functional. The results indicate that wind observations can be both variationally optimized and filtered. The efficiency of GMVA is also checked in a numerical test. Finally, 3-D wind observations with random disturbances are manipulated by GMVA after being filtered.

  18. The current status of the development of the technology on 3D computer simulation in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hee Reyoung; Park, Seung Kook; Chung, Un Soo; Jung, Ki Jung

    2002-05-01

    The development background and property of the COSIDA, which is the 3D computer simulation system for the analysis on the dismantling procedure of the nuclear facilities in Japan was reviewed. The function of the visualization on the work area, Kinematics analysis and dismantling scenario analysis, which are the sub systems of the COSIDA, has been investigated. The physical, geometrical and radiological properties were modelled in 2D or 3D in the sub system of the visualization of the work area. In the sub system of the kinematics analysis, the command set on the basic work procedure for the control of the motion of the models at a cyber space was driven. The suitability of the command set was estimated by the application of COSIDA to the programming on the motion of the remote dismantling tools for dismantling the components of the nuclear facilities at cyber space.

  19. Measurement of facial soft tissues thickness using 3D computed tomographic images

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Ho Gul; Kim, Kee Deog; Shin, Dong Won; Hu, Kyung Seok; Lee, Jae Bum; Park, Hyok; Park, Chang Seo [Yonsei Univ. Hospital, Seoul (Korea, Republic of); Han, Seung Ho [Catholic Univ. of Korea, Seoul (Korea, Republic of)

    2006-03-15

    To evaluate accuracy and reliability of program to measure facial soft tissue thickness using 3D computed tomographic images by comparing with direct measurement. One cadaver was scanned with a Helical CT with 3 mm slice thickness and 3 mm/sec table speed. The acquired data was reconstructed with 1.5 mm reconstruction interval and the images were transferred to a personal computer. The facial soft tissue thickness were measured using a program developed newly in 3D image. For direct measurement, the cadaver was cut with a bone cutter and then a ruler was placed above the cut side. The procedure was followed by taking pictures of the facial soft tissues with a high-resolution digital camera. Then the measurements were done in the photographic images and repeated for ten times. A repeated measure analysis of variance was adopted to compare and analyze the measurements resulting from the two different methods. Comparison according to the areas was analyzed by Mann-Whitney test. There were no statistically significant differences between the direct measurements and those using the 3D images(p>0.05). There were statistical differences in the measurements on 17 points but all the points except 2 points showed a mean difference of 0.5 mm or less. The developed software program to measure the facial soft tissue thickness using 3D images was so accurate that it allows to measure facial soft tissue thickness more easily in forensic science and anthropology.

  20. The computer simulation of 3d gas dynamics in a gas centrifuge

    Science.gov (United States)

    Borman, V. D.; Bogovalov, S. V.; Borisevich, V. D.; Tronin, I. V.; Tronin, V. N.

    2016-09-01

    We argue on the basis of the results of 2D analysis of the gas flow in gas centrifuges that a reliable calculation of the circulation of the gas and gas content in the gas centrifuge is possible only in frameworks of 3D numerical simulation of gas dynamics in the gas centrifuge (hereafter GC). The group from National research nuclear university, MEPhI, has created a computer code for 3D simulation of the gas flow in GC. The results of the computer simulations of the gas flows in GC are presented. A model Iguassu centrifuge is explored for the simulations. A nonaxisymmetric gas flow is produced due to interaction of the hypersonic rotating flow with the scoops for extraction of the product and waste flows from the GC. The scoops produce shock waves penetrating into a working camera of the GC and form spiral waves there.

  1. Analysis of temporal stability of autostereoscopic 3D displays

    Science.gov (United States)

    Rubiño, Manuel; Salas, Carlos; Pozo, Antonio M.; Castro, J. J.; Pérez-Ocón, Francisco

    2013-11-01

    An analysis has been made of the stability of the images generated by electronic autostereoscopic 3D displays, studying the time course of the photometric and colorimetric parameters. The measurements were made on the basis of the procedure recommended in the European guideline EN 61747-6 for the characterization of electronic liquid-crystal displays (LCD). The study uses 3 different models of autostereoscopic 3D displays of different sizes and numbers of pixels, taking the measurements with a spectroradiometer (model PR-670 SpectraScan of PhotoResearch). For each of the displays, the time course is shown for the tristimulus values and the chromaticity coordinates in the XYZ CIE 1931 system and values from the time periods required to reach stable values of these parameters are presented. For the analysis of how the procedure recommended in the guideline EN 61747-6 for 2D displays influenced the results, and for the adaption of the procedure to the characterization of 3D displays, the experimental conditions of the standard procedure were varied, making the stability analysis in the two ocular channels (RE and LE) of the 3D mode and comparing the results with those corresponding to the 2D. The results of our study show that the stabilization time of a autostereoscopic 3D display with parallax barrier technology depends on the tristimulus value analysed (X, Y, Z) as well as on the presentation mode (2D, 3D); furthermore, it was found that whether the 3D mode is used depends on the ocular channel evaluated (RE, LE).

  2. Accuracy of 3D Imaging Software in Cephalometric Analysis

    Science.gov (United States)

    2013-06-21

    orthodontic software program ( Dolphin 3D, mfg, city, state) used for measurement and analysis of craniofacial dimensions. Three-dimensional reconstructions...143(8), 899-902. Baik H, Jeon J, Lee H. (2007). Facial soft tissue analysis of Korean adults with normal occlusion using a 3-dimensional laser

  3. Interactive 3D computer model of the human corneolimbal region

    DEFF Research Database (Denmark)

    Molvaer, Rikke Kongshaug; Andreasen, Arne; Heegaard, Steffen;

    2013-01-01

    in the superior limbal region and one LEC, six LCs and 12 FSPs in the inferior limbal region. Only few LECs, LCs and FSPs were localized nasally and temporally. CONCLUSION: Interactive 3D models are a powerful tool that may help to shed more light on the existence and spatial localization of the different stem......PURPOSE: This study aims to clarify the existence of and to map the localization of different proposed stem cell niches in the corneal limbal region. MATERIALS AND METHODS: One human eye was cut into 2200 consecutive sections. Every other section was stained with haematoxylin and eosin, digitized...... in the limbal region: limbal epithelial crypts (LECs), limbal crypts (LCs) and focal stromal projections (FSPs). In all, eight LECs, 25 LCs and 105 FSPs were identified in the limbal region. The LECs, LCs and FSPs were predominantly located in the superior limbal region with seven LECs, 19 LCs and 93 FSPs...

  4. 3D computational steering with parametrized geometric objects

    NARCIS (Netherlands)

    Mulder, J.D.; Wijk, J.J. van

    1996-01-01

    Computational Steering is the ultimate goal of interactive simulation: researchers change parameters of their simulation and immediately receive feedback on the effect. We present a general and flexible graphics tool that is part of an environment for Computational Steering developed at CWI. It enab

  5. Efficient computation of steady, 3D water-wave patterns

    NARCIS (Netherlands)

    Lewis, M.R.; Koren, B.

    2003-01-01

    Numerical methods for the computation of stationary free surfaces is the subject of much current research in computational engineering. The present report is directed towards free surfaces in maritime engineering. Of interest here are the long steady waves generated by ships, the gravity waves. In t

  6. Computer-assisted three-dimensional surgical planning and simulation: 3D virtual osteotomy.

    Science.gov (United States)

    Xia, J; Ip, H H; Samman, N; Wang, D; Kot, C S; Yeung, R W; Tideman, H

    2000-02-01

    A computer-assisted three-dimensional virtual osteotomy system for orthognathic surgery (CAVOS) is presented. The virtual reality workbench is used for surgical planning. The surgeon immerses in a virtual reality environment with stereo eyewear, holds a virtual "scalpel" (3D Mouse) and operates on a "real" patient (3D visualization) to obtain pre-surgical prediction (3D bony segment movements). Virtual surgery on a computer-generated 3D head model is simulated and can be visualized from any arbitrary viewing point in a personal computer system.

  7. 3D Images of Materials Structures Processing and Analysis

    CERN Document Server

    Ohser, Joachim

    2009-01-01

    Taking and analyzing images of materials' microstructures is essential for quality control, choice and design of all kind of products. Today, the standard method still is to analyze 2D microscopy images. But, insight into the 3D geometry of the microstructure of materials and measuring its characteristics become more and more prerequisites in order to choose and design advanced materials according to desired product properties. This first book on processing and analysis of 3D images of materials structures describes how to develop and apply efficient and versatile tools for geometric analysis

  8. 3D Regression Heat Map Analysis of Population Study Data.

    Science.gov (United States)

    Klemm, Paul; Lawonn, Kai; Glaßer, Sylvia; Niemann, Uli; Hegenscheid, Katrin; Völzke, Henry; Preim, Bernhard

    2016-01-01

    Epidemiological studies comprise heterogeneous data about a subject group to define disease-specific risk factors. These data contain information (features) about a subject's lifestyle, medical status as well as medical image data. Statistical regression analysis is used to evaluate these features and to identify feature combinations indicating a disease (the target feature). We propose an analysis approach of epidemiological data sets by incorporating all features in an exhaustive regression-based analysis. This approach combines all independent features w.r.t. a target feature. It provides a visualization that reveals insights into the data by highlighting relationships. The 3D Regression Heat Map, a novel 3D visual encoding, acts as an overview of the whole data set. It shows all combinations of two to three independent features with a specific target disease. Slicing through the 3D Regression Heat Map allows for the detailed analysis of the underlying relationships. Expert knowledge about disease-specific hypotheses can be included into the analysis by adjusting the regression model formulas. Furthermore, the influences of features can be assessed using a difference view comparing different calculation results. We applied our 3D Regression Heat Map method to a hepatic steatosis data set to reproduce results from a data mining-driven analysis. A qualitative analysis was conducted on a breast density data set. We were able to derive new hypotheses about relations between breast density and breast lesions with breast cancer. With the 3D Regression Heat Map, we present a visual overview of epidemiological data that allows for the first time an interactive regression-based analysis of large feature sets with respect to a disease.

  9. 3D-Aided-Analysis Tool for Lunar Rover

    Institute of Scientific and Technical Information of China (English)

    ZHANG Peng; LI Guo-peng; REN Xin; LIU Jian-jun; GAO Xing-ye; ZOU Xiao-duan

    2013-01-01

    3D-Aided-Analysis Tool (3DAAT) which is a virtual reality system is built up in this paper. 3DAAT is integrated with kinematics and dynamics model of rover as well as real lunar surface terrain mode. Methods of modeling which are proposed in this paper include constructing lunar surface, constructing 3D model of lander and rover, building up kinematic model of rover body. Photogrammetry technique and the remote sensing information are used to generate the terrain model of lunar surface. According to the implementation result, 3DAAT is an effective assist system for making exploration plan and analyzing the status of rover.

  10. AN ANALYSIS OF 3D FINITE CRACKED BODIES

    Institute of Scientific and Technical Information of China (English)

    Tao Weiming; Guo Yimu; Cao Zhiyuan

    2001-01-01

    The new-type traction boundary integral equations developed by Hu and with no hyper singular integral are applied to analysis of 3D finite cracked bodies. A numerical algorithm for general 3D problems and a semi-analytical one for axisymmetric problems are presented. Some examples of thick plates and cylindrical columns including penny-shaped crack(s), and rectangular plates including an elliptical crack normal to the surface are analyzed. The comparison between present results and those in literature shows the high accuracy and effectiveness of the present method.

  11. 3D Network Analysis for Indoor Space Applications

    Science.gov (United States)

    Tsiliakou, E.; Dimopoulou, E.

    2016-10-01

    Indoor space differs from outdoor environments, since it is characterized by a higher level of structural complexity, geometry, as well as topological relations. Indoor space can be considered as the most important component in a building's conceptual modelling, on which applications such as indoor navigation, routing or analysis are performed. Therefore, the conceptual meaning of sub spaces or the activities taking place in physical building boundaries (e.g. walls), require the comprehension of the building's indoor hierarchical structure. The scope of this paper is to perform 3D network analysis in a building's interior and is structured as follows: In Section 1 the definition of indoor space is provided and indoor navigation requirements are analysed. Section 2 describes the processes of indoor space modeling, as well as routing applications. In Section 3, a case study is examined involving a 3D building model generated in CityEngine (exterior shell) and ArcScene (interior parts), in which the use of commercially available software tools (ArcGIS, ESRI), in terms of indoor routing and 3D network analysis, are explored. The fundamentals of performing 3D analysis with the ArcGIS Network Analyst extension were tested. Finally a geoprocessing model was presented, which was specifically designed to be used to interactively find the best route in ArcScene. The paper ends with discussion and concluding remarks on Section 4.

  12. Automatic procedure for realistic 3D finite element modelling of human brain for bioelectromagnetic computations

    Energy Technology Data Exchange (ETDEWEB)

    Aristovich, K Y; Khan, S H, E-mail: kirill.aristovich.1@city.ac.u [School of Engineering and Mathematical Sciences, City University London, Northampton Square, London EC1V 0HB (United Kingdom)

    2010-07-01

    Realistic computer modelling of biological objects requires building of very accurate and realistic computer models based on geometric and material data, type, and accuracy of numerical analyses. This paper presents some of the automatic tools and algorithms that were used to build accurate and realistic 3D finite element (FE) model of whole-brain. These models were used to solve the forward problem in magnetic field tomography (MFT) based on Magnetoencephalography (MEG). The forward problem involves modelling and computation of magnetic fields produced by human brain during cognitive processing. The geometric parameters of the model were obtained from accurate Magnetic Resonance Imaging (MRI) data and the material properties - from those obtained from Diffusion Tensor MRI (DTMRI). The 3D FE models of the brain built using this approach has been shown to be very accurate in terms of both geometric and material properties. The model is stored on the computer in Computer-Aided Parametrical Design (CAD) format. This allows the model to be used in a wide a range of methods of analysis, such as finite element method (FEM), Boundary Element Method (BEM), Monte-Carlo Simulations, etc. The generic model building approach presented here could be used for accurate and realistic modelling of human brain and many other biological objects.

  13. Computation of Edge-Edge-Edge Events Based on Conicoid Theory for 3-D Object Recognition

    Institute of Scientific and Technical Information of China (English)

    WU Chenye; MA Huimin

    2009-01-01

    The availability of a good viewpoint space partition is crucial in three dimensional (3-D) object rec-ognition on the approach of aspect graph. There are two important events depicted by the aspect graph ap-proach, edge-edge-edge (EEE) events and edge-vertex (EV) events. This paper presents an algorithm to compute EEE events by characteristic analysis based on conicoid theory, in contrast to current algorithms that focus too much on EV events and often overlook the importance of EEE events. Also, the paper provides a standard flowchart for the viewpoint space partitioning based on aspect graph theory that makes it suitable for perspective models. The partitioning result best demonstrates the algorithm's efficiency with more valu-able viewpoints found with the help of EEE events, which can definitely help to achieve high recognition rate for 3-D object recognition.

  14. 3-D Experimental Fracture Analysis at High Temperature

    Energy Technology Data Exchange (ETDEWEB)

    John H. Jackson; Albert S. Kobayashi

    2001-09-14

    T*e, which is an elastic-plastic fracture parameter based on incremental theory of plasticity, was determined numerically and experimentally. The T*e integral of a tunneling crack in 2024-T3 aluminum, three point bend specimen was obtained through a hybrid analysis of moire interferometry and 3-D elastic-plastic finite element analysis. The results were verified by the good agreement between the experimentally and numerically determined T*e on the specimen surface.

  15. Building a 3D Computed Tomography Scanner From Surplus Parts.

    Science.gov (United States)

    Haidekker, Mark A

    2014-01-01

    Computed tomography (CT) scanners are expensive imaging devices, often out of reach for small research groups. Designing and building a CT scanner from modular components is possible, and this article demonstrates that realization of a CT scanner from components is surprisingly easy. However, the high costs of a modular X-ray source and detector limit the overall cost savings. In this article, the possibility of building a CT scanner with available surplus X-ray parts is discussed, and a practical device is described that incurred costs of less than $16,000. The image quality of this device is comparable with commercial devices. The disadvantage is that design constraints imposed by the available components lead to slow scan speeds and a resolution of 0.5 mm. Despite these limitations, a device such as this is attractive for imaging studies in the biological and biomedical sciences, as well as for advancing CT technology itself.

  16. Automatic Plant Annotation Using 3D Computer Vision

    DEFF Research Database (Denmark)

    Nielsen, Michael

    -of-squared difference methods and energy-minimizing methods had this problem. Following the test a series of disparity estimation techniques were developed and tested in the test framework using a set of ray traced images and a hand-annotated set of real plants with similar plant shapes. Novel similarity measures were...... individual leaf had to be seperated using a simple labeling algorithm based on connected components analysis (based on Rosenfeld and Pfaltz union-find algorithm) where height information was also included, described as a NURBS surface and annotated with Number of leaves on plant, Area of plant and individual...... reconstruction and extracted features can be used to locate sample locations for multi-spectral reflection analysis. It can be employed during early growth stages in low cost crops or in high cost crops where the grown plants are placed separately. The image acquisition can be done from manually operated...

  17. Suspected feigned knee extensor weakness: usefulness of 3D gait analysis. Case report.

    Science.gov (United States)

    Chaler, Joaquim; Müller, Bertram; Maiques, Anna; Pujol, Eduard

    2010-07-01

    The purpose of the present case report is to show the potential for use of 3D gait analysis as an assessment method of feigned muscle weakness. We describe a patient complaining of right leg pain and weakness. Physical examination showed severe quadriceps muscle weakness in a highly abnormal gait pattern context. Conventional diagnostic workup did not show any relevant findings. Three-dimensional (3D) gait analysis was performed with a 3D motion capture system. Joint angles, internal moments and powers were computed from the motion data. Lower leg muscle surface-electromyography was also performed. During the late stance phase, flexor moment and negative power peaks (indicating eccentric knee extensor activity) were generated in the knee, together with relevant Rectus femoris activity. All findings were highly inconsistent with true quadriceps weakness and gave objective ground to suspect insincerity of patient complaints. 3D gait analysis might be a valuable clinical assessment tool in suspected feigned lower limb muscle weakness.

  18. 3D Guided Wave Motion Analysis on Laminated Composites

    Science.gov (United States)

    Tian, Zhenhua; Leckey, Cara; Yu, Lingyu

    2013-01-01

    Ultrasonic guided waves have proved useful for structural health monitoring (SHM) and nondestructive evaluation (NDE) due to their ability to propagate long distances with less energy loss compared to bulk waves and due to their sensitivity to small defects in the structure. Analysis of actively transmitted ultrasonic signals has long been used to detect and assess damage. However, there remain many challenging tasks for guided wave based SHM due to the complexity involved with propagating guided waves, especially in the case of composite materials. The multimodal nature of the ultrasonic guided waves complicates the related damage analysis. This paper presents results from parallel 3D elastodynamic finite integration technique (EFIT) simulations used to acquire 3D wave motion in the subject laminated carbon fiber reinforced polymer composites. The acquired 3D wave motion is then analyzed by frequency-wavenumber analysis to study the wave propagation and interaction in the composite laminate. The frequency-wavenumber analysis enables the study of individual modes and visualization of mode conversion. Delamination damage has been incorporated into the EFIT model to generate "damaged" data. The potential for damage detection in laminated composites is discussed in the end.

  19. Probabilistic View-based 3D Curve Skeleton Computation on the GPU

    NARCIS (Netherlands)

    Kustra, Jacek; Jalba, Andrei; Telea, Alexandru

    2013-01-01

    Computing curve skeletons of 3D shapes is a challenging task. Recently, a high-potential technique for this task was proposed, based on integrating medial information obtained from several 2D projections of a 3D shape. However effective, this technique is strongly influenced in terms of complexity b

  20. Efficacy of 3-D computed tomographic reconstruction in evaluating anatomical relationships of colovesical fistula.

    Science.gov (United States)

    Shinojima, Toshiaki; Nakajima, Fumio; Koizumi, Jun

    2002-04-01

    A case of colovesical fistula is reported. The anatomy of the pelvis was determined preoperatively with 3-D computed tomography (CT), and the fistula, including adjacent structures, could clearly be seen. Compared with conventional axial CT imaging, 3-D CT provided better and more complete visualization of the anatomical relationships, which facilitated the surgical procedure and provided a good outcome.

  1. CudaPre3D: An Alternative Preprocessing Algorithm for Accelerating 3D Convex Hull Computation on the GPU

    Directory of Open Access Journals (Sweden)

    MEI, G.

    2015-05-01

    Full Text Available In the calculating of convex hulls for point sets, a preprocessing procedure that is to filter the input points by discarding non-extreme points is commonly used to improve the computational efficiency. We previously proposed a quite straightforward preprocessing approach for accelerating 2D convex hull computation on the GPU. In this paper, we extend that algorithm to being used in 3D cases. The basic ideas behind these two preprocessing algorithms are similar: first, several groups of extreme points are found according to the original set of input points and several rotated versions of the input set; then, a convex polyhedron is created using the found extreme points; and finally those interior points locating inside the formed convex polyhedron are discarded. Experimental results show that: when employing the proposed preprocessing algorithm, it achieves the speedups of about 4x on average and 5x to 6x in the best cases over the cases where the proposed approach is not used. In addition, more than 95 percent of the input points can be discarded in most experimental tests.

  2. 3D Computational Simulation of Calcium Leaching in Cement Matrices

    Directory of Open Access Journals (Sweden)

    Gaitero, J. J.

    2014-12-01

    Full Text Available Calcium leaching is a degradation process consisting in progressive dissolution of the cement paste by migration of calcium atoms to the aggressive solution. It is therefore, a complex phenomenon involving several phases and dissolution and diffusion processes simultaneously. Along this work, a new computational scheme for the simulation of the degradation process in three dimensions was developed and tested. The toolkit was used to simulate accelerated calcium leaching by a 6M ammonium nitrate solution in cement matrices. The obtained outputs were the three dimensional representation of the matrix and the physicochemical properties of individual phases as a consequence of the degradation process. This not only makes it possible to study the evolution of such properties as a function of time but also as a function of the position within the matrix. The obtained results are in good agreement with experimental values of the elastic modulus in degraded and undegraded samples.El lixiviado de calcio es un proceso de degradación consistente en la disolución progresiva de la pasta de cemento por la migración de los átomos de calcio a la disolución agresiva. Se trata por tanto de un fenómeno complejo que involucra simultáneamente diferentes fases y procesos de disolución y difusión. En este trabajo se desarrolló y probó una nueva herramienta computacional para la simulación del proceso de degradación en tres dimensiones. Para ello se simuló el lixiviado de calcio acelerado provocado por una disolución de nitrato amónico 6M en matrices de cemento. Como resultado se obtuvieron la representación tridimensional de la matriz y las propiedades físico-químicas sus fases a lo largo del tiempo. Esto permitió estudiar la evolución de dichas propiedades a lo largo del proceso de degradación así como en función de su posición dentro de la matriz. Los resultados obtenidos coinciden con los valores experimentales del módulo elástico tanto

  3. 3D CFD analysis of a twin screw expander

    OpenAIRE

    Kovacevic, A.; S Rane

    2013-01-01

    Twin screw machines can be used as expanders for variety of applications. This paper describes how the performance of an oil free twin screw air expander of 3/5 lobe configuration was estimated by use of full 3D Computational Fluid Dynamics (CFD) applying a procedure similar to that used for screw compressors. The grid generator SCORG© was employed for pre-processing of the moving domains between the rotors while the stationary grids for the ports were derived from a commercial grid generator...

  4. Communicating long-span timber structures with 3D computer visualization

    OpenAIRE

    Janols, Henrik

    2005-01-01

    One of the reasons for the low amount of timber in construction is a general lack of knowledge about timber engineering and how timber can be used to its full advantage. In this thesis the focus is 3D computer visualisation (3D VIZ) of non-residential long-span timber structures, used for storage, industry and sports where 3D VIZ is defined as a process where a 3D-model is enhanced with environmental information e.g. texture maps and realistic light effects. An area of interest is the possibi...

  5. Practical limitations of cone-beam computed tomography in 3D cephalometry%Practical limitations of cone-beam computed tomography in3D cephalometry

    Institute of Scientific and Technical Information of China (English)

    Janalt Damstra; Zacharias Fourie; Yijin Ren

    2011-01-01

    3D cone beam computed tomography (CBCT) images offer a unique and new appreciation of the anatomical structures and underlying anomalies not possible with conventional radiographs.However,in almost all aspects of CBCT imaging,from utilization to application,inherent limitations and pitfalls exist.Importantly,these inherent limitations and pitfalls have practical implications which need to be addressed before the potential of this technology can be fully realized.The purpose of this review was to explore the current limitations and pitfalls associated with CBCT imaging to allow for better and more accurate understanding of the possibilities this imaging modality could offer,particularly pertaining to 3D cephalometry.

  6. Quantitative nanoscale analysis in 3D using electron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kuebel, Christian [Karlsruhe Institute of Technology, INT, 76344 Eggenstein-Leopoldshafen (Germany)

    2011-07-01

    State-of-the-art electron tomography has been established as a powerful tool to image complex structures with nanometer resolution in 3D. Especially STEM tomography is used extensively in materials science in such diverse areas as catalysis, semiconductor materials, and polymer composites mainly providing qualitative information on morphology, shape and distribution of materials. However, for an increasing number of studies quantitative information, e.g. surface area, fractal dimensions, particle distribution or porosity are needed. A quantitative analysis is typically performed after segmenting the tomographic data, which is one of the main sources of error for the quantification. In addition to noise, systematic errors due to the missing wedge and due to artifacts from the reconstruction algorithm itself are responsible for these segmentation errors and improved algorithms are needed. This presentation will provide an overview of the possibilities and limitations of quantitative nanoscale analysis by electron tomography. Using catalysts and nano composites as applications examples, intensities and intensity variations observed for the 3D volume reconstructed by WBP and SIRT will be quantitatively compared to alternative reconstruction algorithms; implications for quantification of electron (or X-ray) tomographic data will be discussed and illustrated for quantification of particle size distributions, particle correlations, surface area, and fractal dimensions in 3D.

  7. Static and dynamic stability analysis using 3D-DDA with incision body scheme

    Institute of Scientific and Technical Information of China (English)

    Wang Jianquan; Lin Gao; Liu Jun

    2006-01-01

    Discontinuous deformation analysis (DDA) provides a powerful numerical tool for the analysis of discontinuous media. This method has been widely applied to the 2D analysis of discontinuous deformation. However, it is hindered from analyzing 3D rock engineering problems mainly due to the lack of reliable 3D contact detection algorithms for polyhedra.Contact detection is a key in 3-D DDA analysis. The limitations and advantages of existing contact detection schemes are discussed in this paper, and a new approach, called the incision body (IB), is proposed, taking into account the advantages of the existing methods. A computer code 3DIB, which uses the IB scheme as a 3D contact detection algorithm, was programmed with Visual C++. Static and dynamic stability analysis for three realistic engineering problems has been carried out. Furthermore, the focus is on studying the stability of a gravity dam on jointed rock foundation and dynamic stability of a fractured gravity dam subject to earthquake shaking. The simulation results show that the program 3DIB and incision body scheme are capable of detecting 3D block contacts correctly and hence simulating the open-close and slide process of jointed block masses. In addition, the code 3DIB could provide an effective tool for evaluating the safety of 3D dam structures, which is quite important for engineering problems.

  8. Computational Approach to 3D Modeling of the Lymph Node Geometry

    Directory of Open Access Journals (Sweden)

    Alexey Kislitsyn

    2015-05-01

    Full Text Available In this study we present a computational approach to the generation of the major geometric structures of an idealized murine lymph node (LN. In this generation, we consider the major compartments such as the subcapsular sinus, B cell follicles, trabecular and medullar sinuses, blood vessels and the T cell zone with a primary focus on the fibroblastic reticular cell (FRC network. Confocal microscopy data of LN macroscopic structures and structural properties of the FRC network have been generated and utilized in the present model. The methodology sets a library of modules that can be used to assemble a solid geometric LN model and subsequently generate an adaptive mesh model capable of implementing transport phenomena. Overall, based on the use of high-resolution confocal microscopy and morphological analysis of cell 3D reconstructions, we have developed a computational model of the LN geometry, suitable for further investigation in studies of fluid transport and cell migration in this immunologically essential organ.

  9. Automated quantification and integrative analysis of 2D and 3D mitochondrial shape and network properties.

    Directory of Open Access Journals (Sweden)

    Julie Nikolaisen

    Full Text Available Mitochondrial morphology and function are coupled in healthy cells, during pathological conditions and (adaptation to endogenous and exogenous stress. In this sense mitochondrial shape can range from small globular compartments to complex filamentous networks, even within the same cell. Understanding how mitochondrial morphological changes (i.e. "mitochondrial dynamics" are linked to cellular (patho physiology is currently the subject of intense study and requires detailed quantitative information. During the last decade, various computational approaches have been developed for automated 2-dimensional (2D analysis of mitochondrial morphology and number in microscopy images. Although these strategies are well suited for analysis of adhering cells with a flat morphology they are not applicable for thicker cells, which require a three-dimensional (3D image acquisition and analysis procedure. Here we developed and validated an automated image analysis algorithm allowing simultaneous 3D quantification of mitochondrial morphology and network properties in human endothelial cells (HUVECs. Cells expressing a mitochondria-targeted green fluorescence protein (mitoGFP were visualized by 3D confocal microscopy and mitochondrial morphology was quantified using both the established 2D method and the new 3D strategy. We demonstrate that both analyses can be used to characterize and discriminate between various mitochondrial morphologies and network properties. However, the results from 2D and 3D analysis were not equivalent when filamentous mitochondria in normal HUVECs were compared with circular/spherical mitochondria in metabolically stressed HUVECs treated with rotenone (ROT. 2D quantification suggested that metabolic stress induced mitochondrial fragmentation and loss of biomass. In contrast, 3D analysis revealed that the mitochondrial network structure was dissolved without affecting the amount and size of the organelles. Thus, our results demonstrate

  10. Electro-holography display using computer generated hologram of 3D objects based on projection spectra

    Science.gov (United States)

    Huang, Sujuan; Wang, Duocheng; He, Chao

    2012-11-01

    A new method of synthesizing computer-generated hologram of three-dimensional (3D) objects is proposed from their projection images. A series of projection images of 3D objects are recorded with one-dimensional azimuth scanning. According to the principles of paraboloid of revolution in 3D Fourier space and 3D central slice theorem, spectra information of 3D objects can be gathered from their projection images. Considering quantization error of horizontal and vertical directions, the spectrum information from each projection image is efficiently extracted in double circle and four circles shape, to enhance the utilization of projection spectra. Then spectra information of 3D objects from all projection images is encoded into computer-generated hologram based on Fourier transform using conjugate-symmetric extension. The hologram includes 3D information of objects. Experimental results for numerical reconstruction of the CGH at different distance validate the proposed methods and show its good performance. Electro-holographic reconstruction can be realized by using an electronic addressing reflective liquid-crystal display (LCD) spatial light modulator. The CGH from the computer is loaded onto the LCD. By illuminating a reference light from a laser source to the LCD, the amplitude and phase information included in the CGH will be reconstructed due to the diffraction of the light modulated by the LCD.

  11. Clinical usefulness of facial soft tissues thickness measurement using 3D computed tomographic images

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Ho Gul; Kim, Kee Deog; Hu, Kyung Seok; Lee, Jae Bum; Park, Hyok [Maxtron Inc., Seoul (Korea, Republic of); Han, Seung Ho [Catholic Univ. of Korea, Seoul (Korea, Republic of); Choi, Seong Ho; Kim, Chong Kwan; Park, Chang Seo [Yonsei Univ., Seoul (Korea, Republic of)

    2006-06-15

    To evaluate clinical usefulness of facial soft tissue thickness measurement using 3D computed tomographic images. One cadaver that had sound facial soft tissues was chosen for the study. The cadaver was scanned with a Helical CT under following scanning protocols about slice thickness and table speed: 3 mm and 3 mm/sec, 5 mm and 5 mm/sec, 7 mm and 7 mm/sec. The acquired data were reconstructed 1.5, 2.5, 3.5 mm reconstruction interval respectively and the images were transferred to a personal computer. Using a program developed to measure facial soft tissue thickness in 3D image, the facial soft tissue thickness was measured. After the ten-time repeation of the measurement for ten times, repeated measure analysis of variance (ANOVA) was adopted to compare and analyze the measurements using the three scanning protocols. Comparison according to the areas was analysed by Mann-Whitney test. There were no statistically significant intraobserver differences in the measurements of the facial soft tissue thickness using the three scanning protocols (p>0.05). There were no statistically significant differences between measurements in the 3 mm slice thickness and those in the 5 mm, 7 mm slice thickness (p>0.05). There were statistical differences in the 14 of the total 30 measured points in the 5 mm slice thickness and 22 in the 7 mm slice thickness. The facial soft tissue thickness measurement using 3D images of 7 mm slice thickness is acceptable clinically, but those of 5 mm slice thickness is recommended for the more accurate measurement.

  12. Detection of Connective Tissue Disorders from 3D Aortic MR Images Using Independent Component Analysis

    DEFF Research Database (Denmark)

    Hansen, Michael Sass; Zhao, Fei; Zhang, Honghai

    2006-01-01

    A computer-aided diagnosis (CAD) method is reported that allows the objective identification of subjects with connective tissue disorders from 3D aortic MR images using segmentation and independent component analysis (ICA). The first step to extend the model to 4D (3D + time) has also been taken....... ICA is an effective tool for connective tissue disease detection in the presence of sparse data using prior knowledge to order the components, and the components can be inspected visually. 3D+time MR image data sets acquired from 31 normal and connective tissue disorder subjects at end-diastole (R......-wave peak) and at 45\\$\\backslash\\$% of the R-R interval were used to evaluate the performance of our method. The automated 3D segmentation result produced accurate aortic surfaces covering the aorta. The CAD method distinguished between normal and connective tissue disorder subjects with a classification...

  13. Computer-based image analysis in radiological diagnostics and image-guided therapy 3D-Reconstruction, contrast medium dynamics, surface analysis, radiation therapy and multi-modal image fusion

    CERN Document Server

    Beier, J

    2001-01-01

    This book deals with substantial subjects of postprocessing and analysis of radiological image data, a particular emphasis was put on pulmonary themes. For a multitude of purposes the developed methods and procedures can directly be transferred to other non-pulmonary applications. The work presented here is structured in 14 chapters, each describing a selected complex of research. The chapter order reflects the sequence of the processing steps starting from artefact reduction, segmentation, visualization, analysis, therapy planning and image fusion up to multimedia archiving. In particular, this includes virtual endoscopy with three different scene viewers (Chap. 6), visualizations of the lung disease bronchiectasis (Chap. 7), surface structure analysis of pulmonary tumors (Chap. 8), quantification of contrast medium dynamics from temporal 2D and 3D image sequences (Chap. 9) as well as multimodality image fusion of arbitrary tomographical data using several visualization techniques (Chap. 12). Thus, the softw...

  14. Advancements in 3D Structural Analysis of Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Siler, Drew L [Nevada Bureau of Mines and Geology, University of Nevada, Reno; Faulds, James E [Nevada Bureau of Mines and Geology, University of Nevada, Reno; Mayhew, Brett [Nevada Bureau of Mines and Geology, University of Nevada, Reno; McNamara, David [Department of Geothermal Science, GNS Science, NZ

    2013-06-23

    Robust geothermal activity in the Great Basin, USA is a product of both anomalously high regional heat flow and active fault-controlled extension. Elevated permeability associated with some fault systems provides pathways for circulation of geothermal fluids. Constraining the local-scale 3D geometry of these structures and their roles as fluid flow conduits is crucial in order to mitigate both the costs and risks of geothermal exploration and to identify blind (no surface expression) geothermal resources. Ongoing studies have indicated that much of the robust geothermal activity in the Great Basin is associated with high density faulting at structurally complex fault intersection/interaction areas, such as accommodation/transfer zones between discrete fault systems, step-overs or relay ramps in fault systems, intersection zones between faults with different strikes or different senses of slip, and horse-tailing fault terminations. These conceptualized models are crucial for locating and characterizing geothermal systems in a regional context. At the local scale, however, pinpointing drilling targets and characterizing resource potential within known or probable geothermal areas requires precise 3D characterization of the system. Employing a variety of surface and subsurface data sets, we have conducted detailed 3D geologic analyses of two Great Basin geothermal systems. Using EarthVision (Dynamic Graphics Inc., Alameda, CA) we constructed 3D geologic models of both the actively producing Brady’s geothermal system and a ‘greenfield’ geothermal prospect at Astor Pass, NV. These 3D models allow spatial comparison of disparate data sets in 3D and are the basis for quantitative structural analyses that can aid geothermal resource assessment and be used to pinpoint discrete drilling targets. The relatively abundant data set at Brady’s, ~80 km NE of Reno, NV, includes 24 wells with lithologies interpreted from careful analysis of cuttings and core, a 1

  15. Analysis of the of bones through 3D computerized tomography; Analise de estrutura ossea atraves de microtomografia computadorizada 3D

    Energy Technology Data Exchange (ETDEWEB)

    Lima, I.; Lopes, R.T. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear; Oliveira, L.F. [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Fisica. Dept. de Fisica Aplicada e Termodinamica; Alves, J.M. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Escola de Engenharia

    2009-03-15

    This work shows the analysis of the internal structure of the bones samples through 3D micro tomography technique (3D-{mu}TC). The comprehension of the bone structure is particularly important when related to osteoporosis diagnosis because this implies in a deterioration of the trabecular bone architecture, which increases the fragility and the possibility to have bone fractures. Two bone samples (human calcaneous and Wistar rat femur) were used, and the method was a radiographic system in real time with an X Ray microfocus tube. The quantifications parameters are based on stereological principles and they are five: a bone volume fraction, trabecular number, the ratio between surface and bone volume, the trabecular thickness and the trabecular separation. The quantifications were done with a program developed especially for this purpose in Nuclear Instrumentation Laboratory - COPPE/UFRJ. This program uses as input the 3D reconstructions images and generates a table with the quantifications. The results of the human calcaneous quantifications are presented in tables 1 and 2, and the 3D reconstructions are illustrated in Figure 5. The Figure 6 illustrate the 2D reconstructed image and the Figure 7 the 3D visualization respectively of the Wistar femur sample. The obtained results show that the 3D-{mu}TC is a powerful technique that can be used to analyze bone microstructures. (author)

  16. Somatotyping using 3D anthropometry: a cluster analysis.

    Science.gov (United States)

    Olds, Tim; Daniell, Nathan; Petkov, John; David Stewart, Arthur

    2013-01-01

    Somatotyping is the quantification of human body shape, independent of body size. Hitherto, somatotyping (including the most popular method, the Heath-Carter system) has been based on subjective visual ratings, sometimes supported by surface anthropometry. This study used data derived from three-dimensional (3D) whole-body scans as inputs for cluster analysis to objectively derive clusters of similar body shapes. Twenty-nine dimensions normalised for body size were measured on a purposive sample of 301 adults aged 17-56 years who had been scanned using a Vitus Smart laser scanner. K-means Cluster Analysis with v-fold cross-validation was used to determine shape clusters. Three male and three female clusters emerged, and were visualised using those scans closest to the cluster centroid and a caricature defined by doubling the difference between the average scan and the cluster centroid. The male clusters were decidedly endomorphic (high fatness), ectomorphic (high linearity), and endo-mesomorphic (a mixture of fatness and muscularity). The female clusters were clearly endomorphic, ectomorphic, and the ecto-mesomorphic (a mixture of linearity and muscularity). An objective shape quantification procedure combining 3D scanning and cluster analysis yielded shape clusters strikingly similar to traditional somatotyping.

  17. 3D texture analysis in renal cell carcinoma tissue image grading.

    Science.gov (United States)

    Kim, Tae-Yun; Cho, Nam-Hoon; Jeong, Goo-Bo; Bengtsson, Ewert; Choi, Heung-Kook

    2014-01-01

    One of the most significant processes in cancer cell and tissue image analysis is the efficient extraction of features for grading purposes. This research applied two types of three-dimensional texture analysis methods to the extraction of feature values from renal cell carcinoma tissue images, and then evaluated the validity of the methods statistically through grade classification. First, we used a confocal laser scanning microscope to obtain image slices of four grades of renal cell carcinoma, which were then reconstructed into 3D volumes. Next, we extracted quantitative values using a 3D gray level cooccurrence matrix (GLCM) and a 3D wavelet based on two types of basis functions. To evaluate their validity, we predefined 6 different statistical classifiers and applied these to the extracted feature sets. In the grade classification results, 3D Haar wavelet texture features combined with principal component analysis showed the best discrimination results. Classification using 3D wavelet texture features was significantly better than 3D GLCM, suggesting that the former has potential for use in a computer-based grading system.

  18. 3D Texture Analysis in Renal Cell Carcinoma Tissue Image Grading

    Directory of Open Access Journals (Sweden)

    Tae-Yun Kim

    2014-01-01

    Full Text Available One of the most significant processes in cancer cell and tissue image analysis is the efficient extraction of features for grading purposes. This research applied two types of three-dimensional texture analysis methods to the extraction of feature values from renal cell carcinoma tissue images, and then evaluated the validity of the methods statistically through grade classification. First, we used a confocal laser scanning microscope to obtain image slices of four grades of renal cell carcinoma, which were then reconstructed into 3D volumes. Next, we extracted quantitative values using a 3D gray level cooccurrence matrix (GLCM and a 3D wavelet based on two types of basis functions. To evaluate their validity, we predefined 6 different statistical classifiers and applied these to the extracted feature sets. In the grade classification results, 3D Haar wavelet texture features combined with principal component analysis showed the best discrimination results. Classification using 3D wavelet texture features was significantly better than 3D GLCM, suggesting that the former has potential for use in a computer-based grading system.

  19. Sensitivity Analysis of the Scattering-Based SARBM3D Despeckling Algorithm.

    Science.gov (United States)

    Di Simone, Alessio

    2016-06-25

    Synthetic Aperture Radar (SAR) imagery greatly suffers from multiplicative speckle noise, typical of coherent image acquisition sensors, such as SAR systems. Therefore, a proper and accurate despeckling preprocessing step is almost mandatory to aid the interpretation and processing of SAR data by human users and computer algorithms, respectively. Very recently, a scattering-oriented version of the popular SAR Block-Matching 3D (SARBM3D) despeckling filter, named Scattering-Based (SB)-SARBM3D, was proposed. The new filter is based on the a priori knowledge of the local topography of the scene. In this paper, an experimental sensitivity analysis of the above-mentioned despeckling algorithm is carried out, and the main results are shown and discussed. In particular, the role of both electromagnetic and geometrical parameters of the surface and the impact of its scattering behavior are investigated. Furthermore, a comprehensive sensitivity analysis of the SB-SARBM3D filter against the Digital Elevation Model (DEM) resolution and the SAR image-DEM coregistration step is also provided. The sensitivity analysis shows a significant robustness of the algorithm against most of the surface parameters, while the DEM resolution plays a key role in the despeckling process. Furthermore, the SB-SARBM3D algorithm outperforms the original SARBM3D in the presence of the most realistic scattering behaviors of the surface. An actual scenario is also presented to assess the DEM role in real-life conditions.

  20. Sensitivity Analysis of the Scattering-Based SARBM3D Despeckling Algorithm

    Directory of Open Access Journals (Sweden)

    Alessio Di Simone

    2016-06-01

    Full Text Available Synthetic Aperture Radar (SAR imagery greatly suffers from multiplicative speckle noise, typical of coherent image acquisition sensors, such as SAR systems. Therefore, a proper and accurate despeckling preprocessing step is almost mandatory to aid the interpretation and processing of SAR data by human users and computer algorithms, respectively. Very recently, a scattering-oriented version of the popular SAR Block-Matching 3D (SARBM3D despeckling filter, named Scattering-Based (SB-SARBM3D, was proposed. The new filter is based on the a priori knowledge of the local topography of the scene. In this paper, an experimental sensitivity analysis of the above-mentioned despeckling algorithm is carried out, and the main results are shown and discussed. In particular, the role of both electromagnetic and geometrical parameters of the surface and the impact of its scattering behavior are investigated. Furthermore, a comprehensive sensitivity analysis of the SB-SARBM3D filter against the Digital Elevation Model (DEM resolution and the SAR image-DEM coregistration step is also provided. The sensitivity analysis shows a significant robustness of the algorithm against most of the surface parameters, while the DEM resolution plays a key role in the despeckling process. Furthermore, the SB-SARBM3D algorithm outperforms the original SARBM3D in the presence of the most realistic scattering behaviors of the surface. An actual scenario is also presented to assess the DEM role in real-life conditions.

  1. Assembly of a 3D Cellular Computer Using Folded E-Blocks

    Directory of Open Access Journals (Sweden)

    Shivendra Pandey

    2016-04-01

    Full Text Available The assembly of integrated circuits in three dimensions (3D provides a possible solution to address the ever-increasing demands of modern day electronic devices. It has been suggested that by using the third dimension, devices with high density, defect tolerance, short interconnects and small overall form factors could be created. However, apart from pseudo 3D architecture, such as monolithic integration, die, or wafer stacking, the creation of paradigms to integrate electronic low-complexity cellular building blocks in architecture that has tile space in all three dimensions has remained elusive. Here, we present software and hardware foundations for a truly 3D cellular computational devices that could be realized in practice. The computing architecture relies on the scalable, self-configurable and defect-tolerant cell matrix. The hardware is based on a scalable and manufacturable approach for 3D assembly using folded polyhedral electronic blocks (E-blocks. We created monomers, dimers and 2 × 2 × 2 assemblies of polyhedral E-blocks and verified the computational capabilities by implementing simple logic functions. We further show that 63.2% more compact 3D circuits can be obtained with our design automation tools compared to a 2D architecture. Our results provide a proof-of-concept for a scalable and manufacture-ready process for constructing massive-scale 3D computational devices.

  2. Soft computing approach to 3D lung nodule segmentation in CT.

    Science.gov (United States)

    Badura, P; Pietka, E

    2014-10-01

    This paper presents a novel, multilevel approach to the segmentation of various types of pulmonary nodules in computed tomography studies. It is based on two branches of computational intelligence: the fuzzy connectedness (FC) and the evolutionary computation. First, the image and auxiliary data are prepared for the 3D FC analysis during the first stage of an algorithm - the masks generation. Its main goal is to process some specific types of nodules connected to the pleura or vessels. It consists of some basic image processing operations as well as dedicated routines for the specific cases of nodules. The evolutionary computation is performed on the image and seed points in order to shorten the FC analysis and improve its accuracy. After the FC application, the remaining vessels are removed during the postprocessing stage. The method has been validated using the first dataset of studies acquired and described by the Lung Image Database Consortium (LIDC) and by its latest release - the LIDC-IDRI (Image Database Resource Initiative) database.

  3. Computer-Designed Splints for Surgical Transfer of 3D Orthognathic Planning.

    Science.gov (United States)

    Zinser, Max; Zoeller, Joachim

    2015-10-01

    Advances in computers and imaging have permitted the adoption of three-dimensional (3D) planning protocols in orthognathic surgery, which may allow a paradigm shift when the computer-assisted planning can be transferred properly. The purpose of this investigation was to introduce an innovative clinical protocol using computer-aided designed and computer-aided manufactured (CAD/CAM) surgical splints for surgical transfer of 3D orthognathic planning compared with the classic technique using arbitrary occlusal splints. The clinical protocols consisted of computed tomography (CT) or cone-beam CT (CBCT) maxillofacial imaging, bone segmentation, 3D diagnosis, computer-assisted surgical treatment planning, and CAD/CAM surgical splints (group A) and manufacture of arbitrary occlusal splints (group B) for intraoperative surgical planning transfer. The observed patients underwent bimaxillary osteotomies and, if necessary, an additional genioplasty. Both techniques were evaluated by applying 13 hard tissue parameters to compare the 3D orthognathic planning (T0) with the postoperative result (T1) using 3D cephalometry. The CAD/CAM splints showed significant better precision for the maxilla (ΔT orthognathic planning, which is more precise compared with the conventional arbitrary occlusal splints.

  4. 3D numerical simulation and analysis of railgun gouging mechanism

    Institute of Scientific and Technical Information of China (English)

    Jin-guo WU; Bo TANG; Qing-hua LIN; Hai-yuan LI; Bao-ming LI

    2016-01-01

    A gouging phenomenon with a hypervelocity sliding electrical contact in railgun not only shortens the rail lifetime but also affects the interior ballistic performance. In this paper, a 3-D numerical model was introduced to simulate and analyze the generation mechanism and evolution of the rail gouging phenomenon. The results show that a rail surface bulge is an important factor to induce gouging. High density and high pressure material flow on the contact surface, obliquely extruded into the rail when accelerating the armature to a high velocity, can produce gouging. Both controlling the bulge size to a certain range and selecting suitable materials for rail surface coating will suppress the formation of gouging. The numerical simulation had a good agreement with experiments, which validated the computing model and methodology are reliable.

  5. 3D numerical simulation and analysis of railgun gouging mechanism

    Directory of Open Access Journals (Sweden)

    Jin-guo Wu

    2016-04-01

    Full Text Available A gouging phenomenon with a hypervelocity sliding electrical contact in railgun not only shortens the rail lifetime but also affects the interior ballistic performance. In this paper, a 3-D numerical model was introduced to simulate and analyze the generation mechanism and evolution of the rail gouging phenomenon. The results show that a rail surface bulge is an important factor to induce gouging. High density and high pressure material flow on the contact surface, obliquely extruded into the rail when accelerating the armature to a high velocity, can produce gouging. Both controlling the bulge size to a certain range and selecting suitable materials for rail surface coating will suppress the formation of gouging. The numerical simulation had a good agreement with experiments, which validated the computing model and methodology are reliable.

  6. Time- and Computation-Efficient Calibration of MEMS 3D Accelerometers and Gyroscopes

    Directory of Open Access Journals (Sweden)

    Sara Stančin

    2014-08-01

    Full Text Available We propose calibration methods for microelectromechanical system (MEMS 3D accelerometers and gyroscopes that are efficient in terms of time and computational complexity. The calibration process for both sensors is simple, does not require additional expensive equipment, and can be performed in the field before or between motion measurements. The methods rely on a small number of defined calibration measurements that are used to obtain the values of 12 calibration parameters. This process enables the static compensation of sensor inaccuracies. The values detected by the 3D sensor are interpreted using a generalized 3D sensor model. The model assumes that the values detected by the sensor are equal to the projections of the measured value on the sensor sensitivity axes. Although this finding is trivial for 3D accelerometers, its validity for 3D gyroscopes is not immediately apparent; thus, this paper elaborates on this latter topic. For an example sensor device, calibration parameters were established using calibration measurements of approximately 1.5 min in duration for the 3D accelerometer and 2.5 min in duration for the 3D gyroscope. Correction of each detected 3D value using the established calibration parameters in further measurements requires only nine addition and nine multiplication operations.

  7. Time- and computation-efficient calibration of MEMS 3D accelerometers and gyroscopes.

    Science.gov (United States)

    Stančin, Sara; Tomažič, Sašo

    2014-08-13

    We propose calibration methods for microelectromechanical system (MEMS) 3D accelerometers and gyroscopes that are efficient in terms of time and computational complexity. The calibration process for both sensors is simple, does not require additional expensive equipment, and can be performed in the field before or between motion measurements. The methods rely on a small number of defined calibration measurements that are used to obtain the values of 12 calibration parameters. This process enables the static compensation of sensor inaccuracies. The values detected by the 3D sensor are interpreted using a generalized 3D sensor model. The model assumes that the values detected by the sensor are equal to the projections of the measured value on the sensor sensitivity axes. Although this finding is trivial for 3D accelerometers, its validity for 3D gyroscopes is not immediately apparent; thus, this paper elaborates on this latter topic. For an example sensor device, calibration parameters were established using calibration measurements of approximately 1.5 min in duration for the 3D accelerometer and 2.5 min in duration for the 3D gyroscope. Correction of each detected 3D value using the established calibration parameters in further measurements requires only nine addition and nine multiplication operations.

  8. 3D computer-assisted assessment of complicated penetrating foreign bodies cases in ENT practice.

    Science.gov (United States)

    Vaiman, Michael; Bekerman, Inessa; Puterman, Max

    2009-10-01

    A retrospective research was performed in order to evaluate three-dimensional (3D) computer-assisted detection of penetrating foreign bodies (FB) in the ENT practice in order to assess its usefulness and to specify its application. FBs in the head and neck were detected using 3D CT imaging in order to assess the usefulness of 3D images in the ENT operative practice. Three blinded surgeons were involved in comparison between plain and 3D CT images in order to assess 3D usefulness for precise formulation of a surgical plan. The observed relationship of the FBs to anatomical structures of the ethmoidal sinuses, eye orbit, and neck tissues was found instrumental for surgeon's decision making in planning the approach to operative removal of the FB. It helps to understand the relationships between a FB and surrounding anatomical structures better then the plain X-rays or CT-scan. There was no significant difference in cost between plain CT and 3D images. 3D computer-assisted detection of FBs increase our diagnostic abilities and appears to be a valuable addition to our diagnostic technique. Its main importance, however, lies in its capacity to help a surgeon plan an operation much more carefully avoiding improvisation during the operation itself.

  9. 3D Massive MIMO Systems: Modeling and Performance Analysis

    KAUST Repository

    Nadeem, Qurrat-Ul-Ain

    2015-07-30

    Multiple-input-multiple-output (MIMO) systems of current LTE releases are capable of adaptation in the azimuth only. Recently, the trend is to enhance system performance by exploiting the channel’s degrees of freedom in the elevation, which necessitates the characterization of 3D channels. We present an information-theoretic channel model for MIMO systems that supports the elevation dimension. The model is based on the principle of maximum entropy, which enables us to determine the distribution of the channel matrix consistent with the prior information on the angles. Based on this model, we provide analytical expression for the cumulative density function (CDF) of the mutual information (MI) for systems with a single receive and finite number of transmit antennas in the general signalto- interference-plus-noise-ratio (SINR) regime. The result is extended to systems with finite receive antennas in the low SINR regime. A Gaussian approximation to the asymptotic behavior of MI distribution is derived for the large number of transmit antennas and paths regime. We corroborate our analysis with simulations that study the performance gains realizable through meticulous selection of the transmit antenna downtilt angles, confirming the potential of elevation beamforming to enhance system performance. The results are directly applicable to the analysis of 5G 3D-Massive MIMO-systems.

  10. Error propagation in the computation of volumes in 3D city models with the Monte Carlo method

    NARCIS (Netherlands)

    Biljecki, F.; Ledoux, H.; Stoter, J.

    2014-01-01

    This paper describes the analysis of the propagation of positional uncertainty in 3D city models to the uncertainty in the computation of their volumes. Current work related to error propagation in GIS is limited to 2D data and 2D GIS operations, especially of rasters. In this research we have (1) d

  11. 3D COMPUTER SIMULATION FOR LIGNIFICATION OF ANCIENT CHINESE TIMBER BUILDINGS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A pioneer research work was carried out by investigators engaged in surveying and mapping for describing ancient Chinese timber buildings by 3D frame graphs w ith a computer.Users can know the structural layers and the assembly process of the se buildings if the frame graphs are processed further with a computer model.Th is can be implemented by computer simulation technique.This technique display t he raw data on the screen of a computer and interactively manage them by combini ng technologies from computer graphics and image processing,multi-media technol ogy,artificial intelligence,highly parallel real-time computation technique an d human behavior science.This paper presents the implementing procedure of ligni fi cation simulation for large-sized wooden buildings as well as 3D dynamic assembl y of these buildings under the 3DS MAX environment.The results from computer sim ulation are also shown in the paper.

  12. 3D-SoftChip: A Novel Architecture for Next-Generation Adaptive Computing Systems

    Directory of Open Access Journals (Sweden)

    Lee Mike Myung-Ok

    2006-01-01

    Full Text Available This paper introduces a novel architecture for next-generation adaptive computing systems, which we term 3D-SoftChip. The 3D-SoftChip is a 3-dimensional (3D vertically integrated adaptive computing system combining state-of-the-art processing and 3D interconnection technology. It comprises the vertical integration of two chips (a configurable array processor and an intelligent configurable switch through an indium bump interconnection array (IBIA. The configurable array processor (CAP is an array of heterogeneous processing elements (PEs, while the intelligent configurable switch (ICS comprises a switch block, 32-bit dedicated RISC processor for control, on-chip program/data memory, data frame buffer, along with a direct memory access (DMA controller. This paper introduces the novel 3D-SoftChip architecture for real-time communication and multimedia signal processing as a next-generation computing system. The paper further describes the advanced HW/SW codesign and verification methodology, including high-level system modeling of the 3D-SoftChip using SystemC, being used to determine the optimum hardware specification in the early design stage.

  13. Integration of 3D anatomical data obtained by CT imaging and 3D optical scanning for computer aided implant surgery

    Directory of Open Access Journals (Sweden)

    Paoli Alessandro

    2011-02-01

    Full Text Available Abstract Background A precise placement of dental implants is a crucial step to optimize both prosthetic aspects and functional constraints. In this context, the use of virtual guiding systems has been recognized as a fundamental tool to control the ideal implant position. In particular, complex periodontal surgeries can be performed using preoperative planning based on CT data. The critical point of the procedure relies on the lack of accuracy in transferring CT planning information to surgical field through custom-made stereo-lithographic surgical guides. Methods In this work, a novel methodology is proposed for monitoring loss of accuracy in transferring CT dental information into periodontal surgical field. The methodology is based on integrating 3D data of anatomical (impression and cast and preoperative (radiographic template models, obtained by both CT and optical scanning processes. Results A clinical case, relative to a fully edentulous jaw patient, has been used as test case to assess the accuracy of the various steps concurring in manufacturing surgical guides. In particular, a surgical guide has been designed to place implants in the bone structure of the patient. The analysis of the results has allowed the clinician to monitor all the errors, which have been occurring step by step manufacturing the physical templates. Conclusions The use of an optical scanner, which has a higher resolution and accuracy than CT scanning, has demonstrated to be a valid support to control the precision of the various physical models adopted and to point out possible error sources. A case study regarding a fully edentulous patient has confirmed the feasibility of the proposed methodology.

  14. Comparative visual analysis of 3D urban wind simulations

    Science.gov (United States)

    Röber, Niklas; Salim, Mohamed; Grawe, David; Leitl, Bernd; Böttinger, Michael; Schlünzen, Heinke

    2016-04-01

    Climate simulations are conducted in large quantity for a variety of different applications. Many of these simulations focus on global developments and study the Earth's climate system using a coupled atmosphere ocean model. Other simulations are performed on much smaller regional scales, to study very small fine grained climatic effects. These microscale climate simulations pose similar, yet also different, challenges for the visualization and the analysis of the simulation data. Modern interactive visualization and data analysis techniques are very powerful tools to assist the researcher in answering and communicating complex research questions. This presentation discusses comparative visualization for several different wind simulations, which were created using the microscale climate model MITRAS. The simulations differ in wind direction and speed, but are all centered on the same simulation domain: An area of Hamburg-Wilhelmsburg that hosted the IGA/IBA exhibition in 2013. The experiments contain a scenario case to analyze the effects of single buildings, as well as examine the impact of the Coriolis force within the simulation. The scenario case is additionally compared with real measurements from a wind tunnel experiment to ascertain the accuracy of the simulation and the model itself. We also compare different approaches for tree modeling and evaluate the stability of the model. In this presentation, we describe not only our workflow to efficiently and effectively visualize microscale climate simulation data using common 3D visualization and data analysis techniques, but also discuss how to compare variations of a simulation and how to highlight the subtle differences in between them. For the visualizations we use a range of different 3D tools that feature techniques for statistical data analysis, data selection, as well as linking and brushing.

  15. Physically based analysis of deformations in 3D images

    Science.gov (United States)

    Nastar, Chahab; Ayache, Nicholas

    1993-06-01

    We present a physically based deformable model which can be used to track and to analyze the non-rigid motion of dynamic structures in time sequences of 2-D or 3-D medical images. The model considers an object undergoing an elastic deformation as a set of masses linked by springs, where the natural lengths of the springs is set equal to zero, and is replaced by a set of constant equilibrium forces, which characterize the shape of the elastic structure in the absence of external forces. This model has the extremely nice property of yielding dynamic equations which are linear and decoupled for each coordinate, whatever the amplitude of the deformation. It provides a reduced algorithmic complexity, and a sound framework for modal analysis, which allows a compact representation of a general deformation by a reduced number of parameters. The power of the approach to segment, track, and analyze 2-D and 3-D images is demonstrated by a set of experimental results on various complex medical images.

  16. 3D FEA Computation of the CLIC Machine Detector Interface Magnets

    CERN Document Server

    Bartalesi, A

    2012-01-01

    A critical aspect of the Compact Linear Collider (CLIC) design is represented by the Accelerator/Experiment interface (called Machine Detector Interface or MDI). In the 3 TeV CLIC layout, the final focus QD0 quadrupole will be located inside the end-cap of the detector itself. This complex MDI scenario required to be simulated with a full 3D-FE analysis. This study was critical to check and control the magnetic cross-talk between the detector solenoid and the final focus magnet and therefore to optimize the design of an “antisolenoids” system needed to shield the QD0 and the e-/e+ beams from the detector magnetic field. In this paper the development and evolution of the computational FE model is presented together with the results obtained and their implication on the CLIC MDI design.

  17. 3-D reconstruction of an ancient Egyptian mummy using X-ray computer tomography.

    Science.gov (United States)

    Baldock, C; Hughes, S W; Whittaker, D K; Taylor, J; Davis, R; Spencer, A J; Tonge, K; Sofat, A

    1994-12-01

    Computer tomography has been used to image and reconstruct in 3-D an Egyptian mummy from the collection of the British Museum. This study of Tjentmutengebtiu, a priestess from the 22nd dynasty (945-715 BC) revealed invaluable information of a scientific, Egyptological and palaeopathological nature without mutilation and destruction of the painted cartonnage case or linen wrappings. Precise details on the removal of the brain through the nasal cavity and the viscera from the abdominal cavity were obtained. The nature and composition of the false eyes were investigated. The detailed analysis of the teeth provided a much closer approximation of age at death. The identification of materials used for the various amulets including that of the figures placed in the viscera was graphically demonstrated using this technique.

  18. Dynamic Characteristic Analysis of Linear DC Motor by 3D EMCN Considering Input Voltage

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Kyung Ho; Yeom, Sang Bu [Changwon National University, Changwon(Korea); Hong, JUNG Pyo; Hur Jin; Kang Do Hyunc [Hanyang University(Seoul Campus), Seoul(Korea)

    2002-02-01

    In order to design the Linear DC Motor (LDM) With improved characteristics, transient and steady state analysis are required. Furthermore, 3D analysis is also needed to analyze the precise characteristics like thrust, time harmonics. This paper deals with the transient and dynamic characteristic analysis if LDM by coupling of external circuit and motion equation using 3D Equivalent Magnetic Circuit Network Method (EMCN). For the three dimensional analysis of electric machine, EMCN is very effective method that ensures high accuracy similar to FEM and short computation time. Also, The modeling by EMCN easily allows the mover to move with respect to the Sartre at each time Also, and the spatial moving step is determined by the solution of the mechanical motion equation and the computed electromagnetic thrust. The results are compared with experimental ones to clarify the usefulness and verify the accuracy of the proposed method. (author). 11 refs., 20 figs., 2 tabs.

  19. Meta!Blast computer game: a pipeline from science to 3D art to education

    Science.gov (United States)

    Schneller, William; Campbell, P. J.; Bassham, Diane; Wurtele, Eve Syrkin

    2012-03-01

    Meta!Blast (http://www.metablast.org) is designed to address the challenges students often encounter in understanding cell and metabolic biology. Developed by faculty and students in biology, biochemistry, computer science, game design, pedagogy, art and story, Meta!Blast is being created using Maya (http://usa.autodesk.com/maya/) and the Unity 3D (http://unity3d.com/) game engine, for Macs and PCs in classrooms; it has also been exhibited in an immersive environment. Here, we describe the pipeline from protein structural data and holographic information to art to the threedimensional (3D) environment to the game engine, by which we provide a publicly-available interactive 3D cellular world that mimics a photosynthetic plant cell.

  20. A 3-D Computational Study of a Variable Camber Continuous Trailing Edge Flap (VCCTEF) Spanwise Segment

    Science.gov (United States)

    Kaul, Upender K.; Nguyen, Nhan T.

    2015-01-01

    Results of a computational study carried out to explore the effects of various elastomer configurations joining spanwise contiguous Variable Camber Continuous Trailing Edge Flap (VCCTEF) segments are reported here. This research is carried out as a proof-of-concept study that will seek to push the flight envelope in cruise with drag optimization as the objective. The cruise conditions can be well off design such as caused by environmental conditions, maneuvering, etc. To handle these off-design conditions, flap deflection is used so when the flap is deflected in a given direction, the aircraft angle of attack changes accordingly to maintain a given lift. The angle of attack is also a design parameter along with the flap deflection. In a previous 2D study,1 the effect of camber was investigated and the results revealed some insight into the relative merit of various camber settings of the VCCTEF. The present state of the art has not advanced sufficiently to do a full 3-D viscous analysis of the whole NASA Generic Transport Model (GTM) wing with VCCTEF deployed with elastomers. Therefore, this study seeks to explore the local effects of three contiguous flap segments on lift and drag of a model devised here to determine possible trades among various flap deflections to achieve desired lift and drag results. Although this approach is an approximation, it provides new insights into the "local" effects of the relative deflections of the contiguous spanwise flap systems and various elastomer segment configurations. The present study is a natural extension of the 2-D study to assess these local 3-D effects. Design cruise condition at 36,000 feet at free stream Mach number of 0.797 and a mean aerodynamic chord (MAC) based Reynolds number of 30.734x10(exp 6) is simulated for an angle of attack (AoA) range of 0 to 6 deg. In the previous 2-D study, the calculations revealed that the parabolic arc camber (1x2x3) and circular arc camber (VCCTEF222) offered the best L

  1. 3D Finite Element Analysis of Particle-Reinforced Aluminum

    Science.gov (United States)

    Shen, H.; Lissenden, C. J.

    2002-01-01

    Deformation in particle-reinforced aluminum has been simulated using three distinct types of finite element model: a three-dimensional repeating unit cell, a three-dimensional multi-particle model, and two-dimensional multi-particle models. The repeating unit cell model represents a fictitious periodic cubic array of particles. The 3D multi-particle (3D-MP) model represents randomly placed and oriented particles. The 2D generalized plane strain multi-particle models were obtained from planar sections through the 3D-MP model. These models were used to study the tensile macroscopic stress-strain response and the associated stress and strain distributions in an elastoplastic matrix. The results indicate that the 2D model having a particle area fraction equal to the particle representative volume fraction of the 3D models predicted the same macroscopic stress-strain response as the 3D models. However, there are fluctuations in the particle area fraction in a representative volume element. As expected, predictions from 2D models having different particle area fractions do not agree with predictions from 3D models. More importantly, it was found that the microscopic stress and strain distributions from the 2D models do not agree with those from the 3D-MP model. Specifically, the plastic strain distribution predicted by the 2D model is banded along lines inclined at 45 deg from the loading axis while the 3D model prediction is not. Additionally, the triaxial stress and maximum principal stress distributions predicted by 2D and 3D models do not agree. Thus, it appears necessary to use a multi-particle 3D model to accurately predict material responses that depend on local effects, such as strain-to-failure, fracture toughness, and fatigue life.

  2. A Review of Failure Analysis Methods for Advanced 3D Microelectronic Packages

    Science.gov (United States)

    Li, Yan; Srinath, Purushotham Kaushik Muthur; Goyal, Deepak

    2016-01-01

    Advanced three dimensional (3D) packaging is a key enabler in driving form factor reduction, performance benefits, and package cost reduction, especially in the fast paced mobility and ultraportable consumer electronics segments. The high level of functional integration and the complex package architecture pose a significant challenge for conventional fault isolation (FI) and failure analysis (FA) methods. Innovative FI/FA tools and techniques are required to tackle the technical and throughput challenges. In this paper, the applications of FI and FA techniques such as Electro Optic Terahertz Pulse Reflectometry, 3D x-ray computed tomography, lock-in thermography, and novel physical sample preparation methods to 3D packages with package on package and stacked die with through silicon via configurations are reviewed, along with the key FI and FA challenges.

  3. 3D city models for CAAD-supported analysis and design of urban areas

    Science.gov (United States)

    Sinning-Meister, M.; Gruen, A.; Dan, H.

    A joint research project was conducted at ETH Zurich to develop a user-friendly software environment for the representation, visual manipulation, analysis and design of urban areas. Three groups were involved in the project: (1) the 'Architecture and Planning' group defined the requirements and expectations for the system; (2) the 'Photogrammetry' group acquired and processed raster and 3D vector data to form a 3D model of the urban area; and (3) the 'CAAD' (Computer Aided Architectural Design) group embedded the data into AutoCAD and implemented database functionality. Results of the photogrammetry group are presented, including the implementation of a 'topology builder' which automatically fits roof planes to manually or semi-automatically measured roof points in order to create AutoCAD-compatible 3D building models. Digital orthoimages and derived products such as perspective views, and the geometric correction of house roofs in digital orthoimages also were generated for test sites in Switzerland.

  4. Novel fully integrated computer system for custom footwear: from 3D digitization to manufacturing

    Science.gov (United States)

    Houle, Pascal-Simon; Beaulieu, Eric; Liu, Zhaoheng

    1998-03-01

    This paper presents a recently developed custom footwear system, which integrates 3D digitization technology, range image fusion techniques, a 3D graphical environment for corrective actions, parametric curved surface representation and computer numerical control (CNC) machining. In this system, a support designed with the help of biomechanics experts can stabilize the foot in a correct and neutral position. The foot surface is then captured by a 3D camera using active ranging techniques. A software using a library of documented foot pathologies suggests corrective actions on the orthosis. Three kinds of deformations can be achieved. The first method uses previously scanned pad surfaces by our 3D scanner, which can be easily mapped onto the foot surface to locally modify the surface shape. The second kind of deformation is construction of B-Spline surfaces by manipulating control points and modifying knot vectors in a 3D graphical environment to build desired deformation. The last one is a manual electronic 3D pen, which may be of different shapes and sizes, and has an adjustable 'pressure' information. All applied deformations should respect a G1 surface continuity, which ensure that the surface can accustom a foot. Once the surface modification process is completed, the resulting data is sent to manufacturing software for CNC machining.

  5. Optimisation of coronary vascular territorial 3D echocardiographic strain imaging using computed tomography

    DEFF Research Database (Denmark)

    de Knegt, Martina Chantal; Fuchs, A; Weeke, P;

    2016-01-01

    Current echocardiographic assessments of coronary vascular territories use the 17-segment model and are based on general assumptions of coronary vascular distribution. Fusion of 3D echocardiography (3DE) with multidetector computed tomography (MDCT) derived coronary anatomy may provide a more acc...

  6. Practical limitations of cone-beam computed tomography in 3D cephalometry

    NARCIS (Netherlands)

    Damstra, Janalt; Fourie, Zacharias; Ren, Yijin

    2011-01-01

    3D cone beam computed tomography (CBCT) images offer a unique and new appreciation of the anatomical structures and underlying anomalies not possible with conventional radiographs. However, in almost all aspects of CBCT imaging, from utilization to application, inherent limitations and pitfalls exis

  7. 3-D Image Analysis of Fluorescent Drug Binding

    Directory of Open Access Journals (Sweden)

    M. Raquel Miquel

    2005-01-01

    Full Text Available Fluorescent ligands provide the means of studying receptors in whole tissues using confocal laser scanning microscopy and have advantages over antibody- or non-fluorescence-based method. Confocal microscopy provides large volumes of images to be measured. Histogram analysis of 3-D image volumes is proposed as a method of graphically displaying large amounts of volumetric image data to be quickly analyzed and compared. The fluorescent ligand BODIPY FL-prazosin (QAPB was used in mouse aorta. Histogram analysis reports the amount of ligand-receptor binding under different conditions and the technique is sensitive enough to detect changes in receptor availability after antagonist incubation or genetic manipulations. QAPB binding was concentration dependent, causing concentration-related rightward shifts in the histogram. In the presence of 10 μM phenoxybenzamine (blocking agent, the QAPB (50 nM histogram overlaps the autofluorescence curve. The histogram obtained for the 1D knockout aorta lay to the left of that of control and 1B knockout aorta, indicating a reduction in 1D receptors. We have shown, for the first time, that it is possible to graphically display binding of a fluorescent drug to a biological tissue. Although our application is specific to adrenergic receptors, the general method could be applied to any volumetric, fluorescence-image-based assay.

  8. Analysis of User Requirements in Interactive 3D Video Systems

    Directory of Open Access Journals (Sweden)

    Haiyue Yuan

    2012-01-01

    Full Text Available The recent development of three dimensional (3D display technologies has resulted in a proliferation of 3D video production and broadcasting, attracting a lot of research into capture, compression and delivery of stereoscopic content. However, the predominant design practice of interactions with 3D video content has failed to address its differences and possibilities in comparison to the existing 2D video interactions. This paper presents a study of user requirements related to interaction with the stereoscopic 3D video. The study suggests that the change of view, zoom in/out, dynamic video browsing, and textual information are the most relevant interactions with stereoscopic 3D video. In addition, we identified a strong demand for object selection that resulted in a follow-up study of user preferences in 3D selection using virtual-hand and ray-casting metaphors. These results indicate that interaction modality affects users’ decision of object selection in terms of chosen location in 3D, while user attitudes do not have significant impact. Furthermore, the ray-casting-based interaction modality using Wiimote can outperform the volume-based interaction modality using mouse and keyboard for object positioning accuracy.

  9. Analysis of Alignment Influence on 3-D Anthropometric Statistics

    Institute of Scientific and Technical Information of China (English)

    CAI Xiuwen; LI Zhizhong; CHANG Chien-Chi; DEMPSEY Patrick

    2005-01-01

    Three-dimensional (3-D) surface anthropometry can provide much more useful information for many applications such as ergonomic product design than traditional individual body dimension measurements. However, the traditional definition of the percentile calculation is designed only for 1-D anthropometric data estimates. The same approach cannot be applied directly to 3-D anthropometric statistics otherwise it could lead to misinterpretations. In this paper, the influence of alignment references on 3-D anthropometric statistics is analyzed mathematically, which shows that different alignment reference points (for example, landmarks) for translation alignment could result in different object shapes if 3-D anthropometric data are processed for percentile values based on coordinates and that dimension percentile calculations based on coordinate statistics are incompatible with those traditionally based on individual dimensions.

  10. Quantitative analysis of autophagy using advanced 3D fluorescence microscopy.

    Science.gov (United States)

    Changou, Chun A; Wolfson, Deanna L; Ahluwalia, Balpreet Singh; Bold, Richard J; Kung, Hsing-Jien; Chuang, Frank Y S

    2013-05-03

    Prostate cancer is the leading form of malignancies among men in the U.S. While surgery carries a significant risk of impotence and incontinence, traditional chemotherapeutic approaches have been largely unsuccessful. Hormone therapy is effective at early stage, but often fails with the eventual development of hormone-refractory tumors. We have been interested in developing therapeutics targeting specific metabolic deficiency of tumor cells. We recently showed that prostate tumor cells specifically lack an enzyme (argininosuccinate synthase, or ASS) involved in the synthesis of the amino acid arginine(1). This condition causes the tumor cells to become dependent on exogenous arginine, and they undergo metabolic stress when free arginine is depleted by arginine deiminase (ADI)(1,10). Indeed, we have shown that human prostate cancer cells CWR22Rv1 are effectively killed by ADI with caspase-independent apoptosis and aggressive autophagy (or macroautophagy)(1,2,3). Autophagy is an evolutionarily-conserved process that allows cells to metabolize unwanted proteins by lysosomal breakdown during nutritional starvation(4,5). Although the essential components of this pathway are well-characterized(6,7,8,9), many aspects of the molecular mechanism are still unclear - in particular, what is the role of autophagy in the death-response of prostate cancer cells after ADI treatment? In order to address this question, we required an experimental method to measure the level and extent of autophagic response in cells - and since there are no known molecular markers that can accurately track this process, we chose to develop an imaging-based approach, using quantitative 3D fluorescence microscopy(11,12). Using CWR22Rv1 cells specifically-labeled with fluorescent probes for autophagosomes and lysosomes, we show that 3D image stacks acquired with either widefield deconvolution microscopy (and later, with super-resolution, structured-illumination microscopy) can clearly capture the early

  11. A 3D contact analysis approach for the visualization of the electrical contact asperities

    Science.gov (United States)

    Swingler, Jonathan

    2017-01-01

    The electrical contact is an important phenomenon that should be given into consideration to achieve better performance and long term reliability for the design of devices. Based upon this importance, the electrical contact interface has been visualized as a ‘‘3D Contact Map’’ and used in order to investigate the contact asperities. The contact asperities describe the structures above and below the contact spots (the contact spots define the 3D contact map) to the two conductors which make the contact system. The contact asperities require the discretization of the 3D microstructures of the contact system into voxels. A contact analysis approach has been developed and introduced in this paper which shows the way to the 3D visualization of the contact asperities of a given contact system. For the discretization of 3D microstructure of contact system into voxels, X-ray Computed Tomography (CT) method is used in order to collect the data of a 250 V, 16 A rated AC single pole rocker switch which is used as a contact system for investigation. PMID:28105383

  12. 3-D Printed Ultem 9085 Testing and Analysis

    Science.gov (United States)

    Aguilar, Daniel; Christensen, Sean; Fox, Emmet J.

    2015-01-01

    The purpose of this document is to analyze the mechanical properties of 3-D printed Ultem 9085. This document will focus on the capabilities, limitations, and complexities of 3D printing in general, and explain the methods by which this material is tested. Because 3-D printing is a relatively new process that offers an innovative means to produce hardware, it is important that the aerospace community understands its current advantages and limitations, so that future endeavors involving 3-D printing may be completely safe. This document encompasses three main sections: a Slosh damage assessment, a destructive test of 3-D printed Ultem 9085 samples, and a test to verify simulation for the 3-D printed SDP (SPHERES Docking Port). Described below, 'Slosh' and 'SDP' refer to two experiments that are built using Ultem 9085 for use with the SPHERES (Synchronized Position Hold, Engage, Reorient, Experimental Satellites) program onboard the International Space Station (ISS) [16]. The SPHERES Facility is managed out of the National Aeronautics and Space Administration (NASA) Ames Research Center in California.

  13. Organ printing: computer-aided jet-based 3D tissue engineering.

    Science.gov (United States)

    Mironov, Vladimir; Boland, Thomas; Trusk, Thomas; Forgacs, Gabor; Markwald, Roger R

    2003-04-01

    Tissue engineering technology promises to solve the organ transplantation crisis. However, assembly of vascularized 3D soft organs remains a big challenge. Organ printing, which we define as computer-aided, jet-based 3D tissue-engineering of living human organs, offers a possible solution. Organ printing involves three sequential steps: pre-processing or development of "blueprints" for organs; processing or actual organ printing; and postprocessing or organ conditioning and accelerated organ maturation. A cell printer that can print gels, single cells and cell aggregates has been developed. Layer-by-layer sequentially placed and solidified thin layers of a thermo-reversible gel could serve as "printing paper". Combination of an engineering approach with the developmental biology concept of embryonic tissue fluidity enables the creation of a new rapid prototyping 3D organ printing technology, which will dramatically accelerate and optimize tissue and organ assembly.

  14. 3D intrathoracic region definition and its application to PET-CT analysis

    Science.gov (United States)

    Cheirsilp, Ronnarit; Bascom, Rebecca; Allen, Thomas W.; Higgins, William E.

    2014-03-01

    Recently developed integrated PET-CT scanners give co-registered multimodal data sets that offer complementary three-dimensional (3D) digital images of the chest. PET (positron emission tomography) imaging gives highly specific functional information of suspect cancer sites, while CT (X-ray computed tomography) gives associated anatomical detail. Because the 3D CT and PET scans generally span the body from the eyes to the knees, accurate definition of the intrathoracic region is vital for focusing attention to the central-chest region. In this way, diagnostically important regions of interest (ROIs), such as central-chest lymph nodes and cancer nodules, can be more efficiently isolated. We propose a method for automatic segmentation of the intrathoracic region from a given co-registered 3D PET-CT study. Using the 3D CT scan as input, the method begins by finding an initial intrathoracic region boundary for a given 2D CT section. Next, active contour analysis, driven by a cost function depending on local image gradient, gradient-direction, and contour shape features, iteratively estimates the contours spanning the intrathoracic region on neighboring 2D CT sections. This process continues until the complete region is defined. We next present an interactive system that employs the segmentation method for focused 3D PET-CT chest image analysis. A validation study over a series of PET-CT studies reveals that the segmentation method gives a Dice index accuracy of less than 98%. In addition, further results demonstrate the utility of the method for focused 3D PET-CT chest image analysis, ROI definition, and visualization.

  15. Digital holography microscopy in 3D biologic samples analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ricardo, J O; Palacios, F; Palacios, G F; Sanchez, A [Department of Physics, University of Oriente (Cuba); Muramatsu, M [Department of General Physics, University of Sao Paulo - Sao Paulo (Brazil); Gesualdi, M [Engineering center, Models and Applied Social Science, UFABC - Sao Paulo (Brazil); Font, O [Department of Bio-ingeniering, University of Oriente - Santiago de Cuba (Cuba); Valin, J L [Mechanics Department, ISPJAE, Habana (Cuba); Escobedo, M; Herold, S [Department of Computation, University of Oriente (Cuba); Palacios, D F, E-mail: frpalaciosf@gmail.com [Department of Nuclear physics, University of Simon BolIva (Venezuela, Bolivarian Republic of)

    2011-01-01

    In this work it is used a setup for Digital Holography Microscopy (MHD) for 3D biologic samples reconstruction. The phase contrast image reconstruction is done by using the Double propagation Method. The system was calibrated and tested by using a micrometric scale and pure phase object respectively. It was simulated the human red blood cell (erythrocyte) and beginning from the simulated hologram the digital 3D phase image for erythrocytes it was calculated. Also there was obtained experimental holograms of human erythrocytes and its corresponding 3D phase images, being evident the correspondence qualitative and quantitative between these characteristics in the simulated erythrocyte and in the experimentally calculated by DHM in both cases.

  16. Novel 3D/VR interactive environment for MD simulations, visualization and analysis.

    Science.gov (United States)

    Doblack, Benjamin N; Allis, Tim; Dávila, Lilian P

    2014-12-18

    The increasing development of computing (hardware and software) in the last decades has impacted scientific research in many fields including materials science, biology, chemistry and physics among many others. A new computational system for the accurate and fast simulation and 3D/VR visualization of nanostructures is presented here, using the open-source molecular dynamics (MD) computer program LAMMPS. This alternative computational method uses modern graphics processors, NVIDIA CUDA technology and specialized scientific codes to overcome processing speed barriers common to traditional computing methods. In conjunction with a virtual reality system used to model materials, this enhancement allows the addition of accelerated MD simulation capability. The motivation is to provide a novel research environment which simultaneously allows visualization, simulation, modeling and analysis. The research goal is to investigate the structure and properties of inorganic nanostructures (e.g., silica glass nanosprings) under different conditions using this innovative computational system. The work presented outlines a description of the 3D/VR Visualization System and basic components, an overview of important considerations such as the physical environment, details on the setup and use of the novel system, a general procedure for the accelerated MD enhancement, technical information, and relevant remarks. The impact of this work is the creation of a unique computational system combining nanoscale materials simulation, visualization and interactivity in a virtual environment, which is both a research and teaching instrument at UC Merced.

  17. Computer-assisted diagnostic system for neurodegenerative dementia using brain SPECT and 3D-SSP

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Kazunari; Kanda, Tomonori; Uemura, Takafumi; Miyamoto, Naokazu; Yoshikawa, Toshiki [Hyogo Brain and Heart Center, Department of Radiology and Nuclear Medicine, Himeji, Hyogo (Japan); Shimada, Kenichi; Ohkawa, Shingo [Hyogo Brain and Heart Center, Institute for Aging Brain and Cognitive Disorders, Himeji, Hyogo (Japan); Minoshima, Satoshi [University of Washington, Radiology and Bioengineering, Department of Radiology, Seattle, WA (United States)

    2009-05-15

    To develop a computer-assisted automated diagnostic system to distinguish among Alzheimer disease (AD), dementia with Lewy bodies (DLB), and other degenerative disorders in patients with mild dementia. Single photon emission computed tomography (SPECT) images with injection of N-Isopropyl-p-[{sup 123}I]iodoamphetamine (IMP) were obtained from patients with mild degenerative dementia. First, datasets from 20 patients mild AD, 15 patients with dementia with DLB, and 17 healthy controls were used to develop an automated diagnosing system based on three-dimensional stereotactic surface projections (3D-SSP). AD- and DLB-specific regional templates were created using 3D-SSP, and critical Z scores in the templates were established. Datasets from 50 AD patients, 8 DLB patients, and 10 patients with non-AD/DLB type degenerative dementia (5 with frontotemporal dementia and 5 with progressive supranuclear palsy) were then used to test the diagnostic accuracy of the optimized automated system in comparison to the diagnostic interpretation of conventional IMP-SPECT images. These comparisons were performed to differentiate AD and DLB from non-AD/DLB and to distinguish AD from DLB. A receiver operating characteristic (ROC) analysis was performed. The area under the ROC curve (Az) and the accuracy of the automated diagnosis system were 0.89 and 82%, respectively, for AD/DLB vs. non-AD/DLB patients, and 0.70 and 65%, respectively, for AD vs. DLB patients. The mean Az and the accuracy of the visual inspection were 0.84 and 77%, respectively, for AD/DLB vs. non-AD/DLB patients, and 0.70 and 65%, respectively, for AD vs. DLB patients. The mean Az and the accuracy of the combination of visual inspection and this system were 0.96 and 91%, respectively, for AD/DLB vs. non-AD/DLB patients, and 0.70 and 66%, respectively, for AD vs. DLB patients. The system developed in the present study achieved as good discrimination of AD, DLB, and other degenerative disorders in patients with mild

  18. 3-D inelastic analysis methods for hot section components. Volume 2: Advanced special functions models

    Science.gov (United States)

    Wilson, R. B.; Banerjee, P. K.

    1987-01-01

    This Annual Status Report presents the results of work performed during the third year of the 3-D Inelastic Analysis Methods for Hot Sections Components program (NASA Contract NAS3-23697). The objective of the program is to produce a series of computer codes that permit more accurate and efficient three-dimensional analyses of selected hot section components, i.e., combustor liners, turbine blades, and turbine vanes. The computer codes embody a progression of mathematical models and are streamlined to take advantage of geometrical features, loading conditions, and forms of material response that distinguish each group of selected components.

  19. Evaluation of the Possibility of Applying Spatial 3D Imaging Using X-Ray Computed Tomography Reconstruction Methods for Quantitative Analysis of Multiphase Materials / Rentgenowska Analiza Ilościowa Materiałów Wielofazowych Z Wykorzystaniem Przestrzennego Obrazowania (3D Przy Użyciu Metod Rekonstrukcji Tomografii Komputerowej

    Directory of Open Access Journals (Sweden)

    Matysik P.

    2015-12-01

    Full Text Available In this paper the possibility of using X-ray computed tomography (CT in quantitative metallographic studies of homogeneous and composite materials is presented. Samples of spheroidal cast iron, Fe-Ti powder mixture compact and epoxy composite reinforced with glass fibers, were subjected to comparative structural tests. Volume fractions of each of the phase structure components were determined by conventional methods with the use of a scanning electron microscopy (SEM and X-ray diffraction (XRD quantitative analysis methods. These results were compared with those obtained by the method of spatial analysis of the reconstructed CT image. Based on the comparative analysis, taking into account the selectivity of data verification methods and the accuracy of the obtained results, the authors conclude that the method of computed tomography is suitable for quantitative analysis of several types of structural materials.

  20. Gust Acoustics Computation with a Space-Time CE/SE Parallel 3D Solver

    Science.gov (United States)

    Wang, X. Y.; Himansu, A.; Chang, S. C.; Jorgenson, P. C. E.; Reddy, D. R. (Technical Monitor)

    2002-01-01

    The benchmark Problem 2 in Category 3 of the Third Computational Aero-Acoustics (CAA) Workshop is solved using the space-time conservation element and solution element (CE/SE) method. This problem concerns the unsteady response of an isolated finite-span swept flat-plate airfoil bounded by two parallel walls to an incident gust. The acoustic field generated by the interaction of the gust with the flat-plate airfoil is computed by solving the 3D (three-dimensional) Euler equations in the time domain using a parallel version of a 3D CE/SE solver. The effect of the gust orientation on the far-field directivity is studied. Numerical solutions are presented and compared with analytical solutions, showing a reasonable agreement.

  1. Sand transverse dune aerodynamics: 3D Coherent Flow Structures from a computational study

    CERN Document Server

    Bruno, Luca

    2015-01-01

    The engineering interest about dune fields is dictated by the their interaction with a number of human infrastructures in arid environments. The aerodynamic behaviour of sand dunes in atmospheric boundary layer belongs to the class of bluff bodies. Because of their simple geometry and their frequent occurrence in desert area, transverse sand dunes are usually adopted in literature as a benchmark to investigate dune aerodynamics by means of both computational or experimental approach, usually in nominally 2D setups. The writers suspect the flow in the wake is characterised by 3D features and affected by wind tunnel setup - e.g. blockage effect, duct side wall boundary layer, incoming velocity profile - when experimental studies are carried out. The present study aims at evaluating the 3D flow features of an idealised transverse dune under different setup conditions by means of computational simulations and to compare the obtained results with experimental measurements.

  2. A 3-D aerodynamic method for the analysis of isolated horizontal-axis wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Ammara, I.; Masson, C.; Paraschivoiu, I. [Ecole Polytechnique, Montreal (Canada)

    1997-12-31

    In most existing performance-analysis methods, wind turbines are considered isolated so that interference effects caused by other rotors or by the site topography are neglected. The main objective of this paper is to propose a practical 3-D method suitable for the study of these effects, in order to optimize the arrangement and the positioning of Horizontal-Axis Wind Turbines (HAWTs) in a wind farm. In the proposed methodology, the flow field around isolated HAWTs is predicted by solving the 3-D, time-averaged, steady-state, incompressible, Navier-Stokes equations in which the turbines are represented by distributions of momentum sources. The resulting governing equations are solved using a Control-Volume Finite Element Method (CVFEM). The fundamental aspects related to the development of a practical 3-D method are discussed in this paper, with an emphasis on some of the challenges that arose during its implementation. The current implementation is limited to the analysis of isolated HAWTs. Preliminary results have indicated that, the proposed 3-D method reaches the same level of accuracy, in terms of performance predictions, that the previously developed 2-D axisymmetric model and the well-known momentum-strip theory, while still using reasonable computers resources. It can be considered as a useful tool for the design of HAWTs. Its main advantages, however, are its intrinsic capacity to predict the details of the flow in the wake, and its capabilities of modelling arbitrary wind-turbine arrangements and including ground effects.

  3. Confocal 3D DNA Cytometry: Assessment of Required Coefficient of Variation by Computer Simulation

    Directory of Open Access Journals (Sweden)

    Lennert S. Ploeger

    2004-01-01

    Full Text Available Background: Confocal Laser Scanning Microscopy (CLSM provides the opportunity to perform 3D DNA content measurements on intact cells in thick histological sections. So far, sample size has been limited by the time consuming nature of the technology. Since the power of DNA histograms to resolve different stemlines depends on both the sample size and the coefficient of variation (CV of histogram peaks, interpretation of 3D CLSM DNA histograms might be hampered by both a small sample size and a large CV. The aim of this study was to analyze the required CV for 3D CLSM DNA histograms given a realistic sample size. Methods: By computer simulation, virtual histograms were composed for sample sizes of 20000, 10000, 5000, 1000, and 273 cells and CVs of 30, 25, 20, 15, 10 and 5%. By visual inspection, the histogram quality with respect to resolution of G0/1 and G2/M peaks of a diploid stemline was assessed. Results: As expected, the interpretability of DNA histograms deteriorated with decreasing sample sizes and higher CVs. For CVs of 15% and lower, a clearly bimodal peak pattern with well distinguishable G0/1 and G2/M peaks were still seen at a sample size of 273 cells, which is our current average sample size with 3D CLSM DNA cytometry. Conclusions: For unambiguous interpretation of DNA histograms obtained using 3D CLSM, a CV of at most 15% is tolerable at currently achievable sample sizes. To resolve smaller near diploid stemlines, a CV of 10% or better should be aimed at. With currently available 3D imaging technology, this CV is achievable.

  4. GBM Volumetry using the 3D Slicer Medical Image Computing Platform

    Science.gov (United States)

    Egger, Jan; Kapur, Tina; Fedorov, Andriy; Pieper, Steve; Miller, James V.; Veeraraghavan, Harini; Freisleben, Bernd; Golby, Alexandra J.; Nimsky, Christopher; Kikinis, Ron

    2013-01-01

    Volumetric change in glioblastoma multiforme (GBM) over time is a critical factor in treatment decisions. Typically, the tumor volume is computed on a slice-by-slice basis using MRI scans obtained at regular intervals. (3D)Slicer – a free platform for biomedical research – provides an alternative to this manual slice-by-slice segmentation process, which is significantly faster and requires less user interaction. In this study, 4 physicians segmented GBMs in 10 patients, once using the competitive region-growing based GrowCut segmentation module of Slicer, and once purely by drawing boundaries completely manually on a slice-by-slice basis. Furthermore, we provide a variability analysis for three physicians for 12 GBMs. The time required for GrowCut segmentation was on an average 61% of the time required for a pure manual segmentation. A comparison of Slicer-based segmentation with manual slice-by-slice segmentation resulted in a Dice Similarity Coefficient of 88.43 ± 5.23% and a Hausdorff Distance of 2.32 ± 5.23 mm. PMID:23455483

  5. Reliability of 3D upper limb motion analysis in children with obstetric brachial plexus palsy.

    Science.gov (United States)

    Mahon, Judy; Malone, Ailish; Kiernan, Damien; Meldrum, Dara

    2017-03-01

    Kinematics, measured by 3D upper limb motion analysis (3D-ULMA), can potentially increase understanding of movement patterns by quantifying individual joint contributions. Reliability in children with obstetric brachial plexus palsy (OBPP) has not been established.

  6. Yield and Cost Analysis or 3D Stacked ICs

    NARCIS (Netherlands)

    Taouil, M.

    2014-01-01

    3D stacking is an emerging technology promising many benefits such as low latency between stacked dies, reduced power consumption, high bandwidth communication, improved form factor and package volume density, heterogeneous integration, and low-cost manufacturing. However, it requires modification o

  7. A Texture Analysis of 3D Radar Images

    NARCIS (Netherlands)

    Deiana, D.; Yarovoy, A.

    2009-01-01

    In this paper a texture feature coding method to be applied to high-resolution 3D radar images in order to improve target detection is developed. An automatic method for image segmentation based on texture features is proposed. The method has been able to automatically detect weak targets which fail

  8. Novel computer vision algorithm for the reliable analysis of organelle morphology in whole cell 3D images--A pilot study for the quantitative evaluation of mitochondrial fragmentation in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Lautenschläger, Janin; Lautenschläger, Christian; Tadic, Vedrana; Süße, Herbert; Ortmann, Wolfgang; Denzler, Joachim; Stallmach, Andreas; Witte, Otto W; Grosskreutz, Julian

    2015-11-01

    The function of intact organelles, whether mitochondria, Golgi apparatus or endoplasmic reticulum (ER), relies on their proper morphological organization. It is recognized that disturbances of organelle morphology are early events in disease manifestation, but reliable and quantitative detection of organelle morphology is difficult and time-consuming. Here we present a novel computer vision algorithm for the assessment of organelle morphology in whole cell 3D images. The algorithm allows the numerical and quantitative description of organelle structures, including total number and length of segments, cell and nucleus area/volume as well as novel texture parameters like lacunarity and fractal dimension. Applying the algorithm we performed a pilot study in cultured motor neurons from transgenic G93A hSOD1 mice, a model of human familial amyotrophic lateral sclerosis. In the presence of the mutated SOD1 and upon excitotoxic treatment with kainate we demonstrate a clear fragmentation of the mitochondrial network, with an increase in the number of mitochondrial segments and a reduction in the length of mitochondria. Histogram analyses show a reduced number of tubular mitochondria and an increased number of small mitochondrial segments. The computer vision algorithm for the evaluation of organelle morphology allows an objective assessment of disease-related organelle phenotypes with greatly reduced examiner bias and will aid the evaluation of novel therapeutic strategies on a cellular level.

  9. RF-TSV DESIGN, MODELING AND APPLICATION FOR 3D MULTI-CORE COMPUTER SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Yu Le; Yang Haigang; Xie Yuanlu

    2012-01-01

    The state-of-the-art multi-core computer systems are based on Very Large Scale three Dimensional (3D) Integrated circuits (VLSI).In order to provide high-speed vertical data transmission in such 3D systems,efficient Through-Silicon Via (TSV) technology is critically important.In this paper,various Radio Frequency (RF) TSV designs and models are proposed.Specifically,the Cu-plug TSV with surrounding ground TSVs is used as the baseline structure.For further improvement,the dielectric coaxial and novel air-gap coaxial TSVs are introduced.Using the empirical parameters of these coaxial TSVs,the simulation results are obtained demonstrating that these coaxial RF-TSVs can provide two-order higher of cut-off frequencies than the Cu-plug TSVs.Based on these new RF-TSV technologies,we propose a novel 3D multi-core computer system as well as new architectures for manipulating the interfaces between RF and baseband circuit.Taking into consideration the scaling down of IC manufacture technologies,predictions for the performance of future generations of circuits are made.With simulation results indicating energy per bit and area per bit being reduced by 7% and 11% respectively,we can conclude that the proposed method is a worthwhile guideline for the design of future multi-core computer ICs.

  10. A 3D learning playground for potential attention training in ADHD: A brain computer interface approach.

    Science.gov (United States)

    Ali, Abdulla; Puthusserypady, Sadasivan

    2015-01-01

    This paper presents a novel brain-computer-interface (BCI) system that could potentially be used for enhancing the attention ability of subjects with attention deficit hyperactivity disorder (ADHD). It employs the steady state visual evoked potential (SSVEP) paradigm. The developed system consists of a 3D classroom environment with active 3D distractions and 2D games executed on the blackboard. The system is concealed as a game (with stages of varying difficulty) with an underlying story to motivate the subjects. It was tested on eleven healthy subjects and the results undeniably establish that by moving to a higher stage in the game where the 2D environment is changed to 3D along with the added 3D distractions, the difficulty level in keeping attention on the main task increases for the subjects. Results also show a mean accuracy of 92.26 ± 7.97% and a mean average selection time of 3.07 ± 1.09 seconds.

  11. Computer-aided planning and reconstruction of cranial 3D implants.

    Science.gov (United States)

    Gall, Markus; Xing Li; Xiaojun Chen; Schmalstieg, Dieter; Egger, Jan

    2016-08-01

    In this contribution, a prototype for semiautomatic computer-aided planning and reconstruction of cranial 3D Implants is presented. The software prototype guides the user through the workflow, beginning with loading and mirroring the patient's head to obtain an initial curvature of the cranial implant. However, naïve mirroring is not sufficient for an implant, because human heads are in general too asymmetric. Thus, the user can perform Laplacian smoothing, followed by Delaunay triangulation, for generating an aesthetic looking and well-fitting implant. Finally, our software prototype allows to save the designed 3D model of the implant as a STL-file for 3D printing. The 3D printed implant can be used for further pre-interventional planning or even as the final implant for the patient. In summary, our findings show that a customized MeVisLab prototype can be an alternative to complex commercial planning software, which may not be available in a clinic.

  12. 3D animation of facial plastic surgery based on computer graphics

    Science.gov (United States)

    Zhang, Zonghua; Zhao, Yan

    2013-12-01

    More and more people, especial women, are getting desired to be more beautiful than ever. To some extent, it becomes true because the plastic surgery of face was capable in the early 20th and even earlier as doctors just dealing with war injures of face. However, the effect of post-operation is not always satisfying since no animation could be seen by the patients beforehand. In this paper, by combining plastic surgery of face and computer graphics, a novel method of simulated appearance of post-operation will be given to demonstrate the modified face from different viewpoints. The 3D human face data are obtained by using 3D fringe pattern imaging systems and CT imaging systems and then converted into STL (STereo Lithography) file format. STL file is made up of small 3D triangular primitives. The triangular mesh can be reconstructed by using hash function. Top triangular meshes in depth out of numbers of triangles must be picked up by ray-casting technique. Mesh deformation is based on the front triangular mesh in the process of simulation, which deforms interest area instead of control points. Experiments on face model show that the proposed 3D animation facial plastic surgery can effectively demonstrate the simulated appearance of post-operation.

  13. 3D fast adaptive correlation imaging for large-scale gravity data based on GPU computation

    Science.gov (United States)

    Chen, Z.; Meng, X.; Guo, L.; Liu, G.

    2011-12-01

    In recent years, large scale gravity data sets have been collected and employed to enhance gravity problem-solving abilities of tectonics studies in China. Aiming at the large scale data and the requirement of rapid interpretation, previous authors have carried out a lot of work, including the fast gradient module inversion and Euler deconvolution depth inversion ,3-D physical property inversion using stochastic subspaces and equivalent storage, fast inversion using wavelet transforms and a logarithmic barrier method. So it can be say that 3-D gravity inversion has been greatly improved in the last decade. Many authors added many different kinds of priori information and constraints to deal with nonuniqueness using models composed of a large number of contiguous cells of unknown property and obtained good results. However, due to long computation time, instability and other shortcomings, 3-D physical property inversion has not been widely applied to large-scale data yet. In order to achieve 3-D interpretation with high efficiency and precision for geological and ore bodies and obtain their subsurface distribution, there is an urgent need to find a fast and efficient inversion method for large scale gravity data. As an entirely new geophysical inversion method, 3D correlation has a rapid development thanks to the advantage of requiring no a priori information and demanding small amount of computer memory. This method was proposed to image the distribution of equivalent excess masses of anomalous geological bodies with high resolution both longitudinally and transversely. In order to tranform the equivalence excess masses into real density contrasts, we adopt the adaptive correlation imaging for gravity data. After each 3D correlation imaging, we change the equivalence into density contrasts according to the linear relationship, and then carry out forward gravity calculation for each rectangle cells. Next, we compare the forward gravity data with real data, and

  14. THERM3D -- A boundary element computer program for transient heat conduction problems

    Energy Technology Data Exchange (ETDEWEB)

    Ingber, M.S. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Mechanical Engineering

    1994-02-01

    The computer code THERM3D implements the direct boundary element method (BEM) to solve transient heat conduction problems in arbitrary three-dimensional domains. This particular implementation of the BEM avoids performing time-consuming domain integrations by approximating a ``generalized forcing function`` in the interior of the domain with the use of radial basis functions. An approximate particular solution is then constructed, and the original problem is transformed into a sequence of Laplace problems. The code is capable of handling a large variety of boundary conditions including isothermal, specified flux, convection, radiation, and combined convection and radiation conditions. The computer code is benchmarked by comparisons with analytic and finite element results.

  15. Analysis of 3-D Propagation Effects Due to Environmental Variability

    Science.gov (United States)

    2014-09-30

    presence of 3-D environmental variations, especially shelf break canyons . Work was also performed in support of 2-D propagation in shallow water to...propagation in the Monterey Bay Canyon . This was motivated by observations of highly variable directional features in measured acoustic vector data...Rev. 8-98) Prescribed by ANSI Std Z39-18 2 the Monterey Bay Canyon were used as inputs to the model, and broadband calculations were performed

  16. A hybrid method for the computation of quasi-3D seismograms.

    Science.gov (United States)

    Masson, Yder; Romanowicz, Barbara

    2013-04-01

    The development of powerful computer clusters and efficient numerical computation methods, such as the Spectral Element Method (SEM) made possible the computation of seismic wave propagation in a heterogeneous 3D earth. However, the cost of theses computations is still problematic for global scale tomography that requires hundreds of such simulations. Part of the ongoing research effort is dedicated to the development of faster modeling methods based on the spectral element method. Capdeville et al. (2002) proposed to couple SEM simulations with normal modes calculation (C-SEM). Nissen-Meyer et al. (2007) used 2D SEM simulations to compute 3D seismograms in a 1D earth model. Thanks to these developments, and for the first time, Lekic et al. (2011) developed a 3D global model of the upper mantle using SEM simulations. At the local and continental scale, adjoint tomography that is using a lot of SEM simulation can be implemented on current computers (Tape, Liu et al. 2009). Due to their smaller size, these models offer higher resolution. They provide us with images of the crust and the upper part of the mantle. In an attempt to teleport such local adjoint tomographic inversions into the deep earth, we are developing a hybrid method where SEM computation are limited to a region of interest within the earth. That region can have an arbitrary shape and size. Outside this region, the seismic wavefield is extrapolated to obtain synthetic data at the Earth's surface. A key feature of the method is the use of a time reversal mirror to inject the wavefield induced by distant seismic source into the region of interest (Robertsson and Chapman 2000). We compute synthetic seismograms as follow: Inside the region of interest, we are using regional spectral element software RegSEM to compute wave propagation in 3D. Outside this region, the wavefield is extrapolated to the surface by convolution with the Green's functions from the mirror to the seismic stations. For now, these

  17. Computer-aided diagnosis for osteoporosis using chest 3D CT images

    Science.gov (United States)

    Yoneda, K.; Matsuhiro, M.; Suzuki, H.; Kawata, Y.; Niki, N.; Nakano, Y.; Ohmatsu, H.; Kusumoto, M.; Tsuchida, T.; Eguchi, K.; Kaneko, M.

    2016-03-01

    The patients of osteoporosis comprised of about 13 million people in Japan and it is one of the problems the aging society has. In order to prevent the osteoporosis, it is necessary to do early detection and treatment. Multi-slice CT technology has been improving the three dimensional (3-D) image analysis with higher body axis resolution and shorter scan time. The 3-D image analysis using multi-slice CT images of thoracic vertebra can be used as a support to diagnose osteoporosis and at the same time can be used for lung cancer diagnosis which may lead to early detection. We develop automatic extraction and partitioning algorithm for spinal column by analyzing vertebral body structure, and the analysis algorithm of the vertebral body using shape analysis and a bone density measurement for the diagnosis of osteoporosis. Osteoporosis diagnosis support system obtained high extraction rate of the thoracic vertebral in both normal and low doses.

  18. 3D histomorphometric quantification of trabecular bones by computed microtomography using synchrotron radiation.

    Science.gov (United States)

    Nogueira, L P; Braz, D; Barroso, R C; Oliveira, L F; Pinheiro, C J G; Dreossi, D; Tromba, G

    2010-12-01

    Conventional bone histomorphometry is an important method for quantitative evaluation of bone microstructure. X-ray computed microtomography is a non-invasive technique, which can be used to evaluate histomorphometric indices in trabecular bones (BV/TV, BS/BV, Tb.N, Tb.Th, Tb.Sp). In this technique, 3D images are used to quantify the whole sample, differently from the conventional one, in which the quantification is performed in 2D slices and extrapolated for 3D case. In this work, histomorphometric quantification using synchrotron 3D X-ray computed microtomography was performed to quantify the bone structure at different skeletal sites as well as to investigate the effects of bone diseases on quantitative understanding of bone architecture. The images were obtained at Synchrotron Radiation for MEdical Physics (SYRMEP) beamline, at ELETTRA synchrotron radiation facility, Italy. Concerning the obtained results for normal and pathological bones from same skeletal sites and individuals, from our results, a certain declining bone volume fraction was achieved. The results obtained could be used in forming the basis for comparison of the bone microarchitecture and can be a valuable tool for predicting bone fragility.

  19. Comparative Analysis of Photogrammetric Methods for 3D Models for Museums

    DEFF Research Database (Denmark)

    Hafstað Ármannsdottir, Unnur Erla; Antón Castro, Francesc/François; Mioc, Darka

    2014-01-01

    to 3D models using Sketchup and Designing Reality. Finally, panoramic photography is discussed as a 2D alternative to 3D. Sketchup is a free-ware 3D drawing program and Designing Reality is a commercial program, which uses Structure from motion. For each program/method, the same comparative analysis...

  20. Computational fluid dynamics simulations of blood flow regularized by 3D phase contrast MRI

    DEFF Research Database (Denmark)

    Rispoli, Vinicius C; Nielsen, Jon; Nayak, Krishna S

    2015-01-01

    approach in regularizing 3D flow fields is evaluated. METHODS: The proposed algorithm incorporates both a Newtonian fluid physics model and a linear PC-MRI signal model. The model equations are solved numerically using a modified CFD algorithm. The numerical solution corresponds to the optimal solution......BACKGROUND: Phase contrast magnetic resonance imaging (PC-MRI) is used clinically for quantitative assessment of cardiovascular flow and function, as it is capable of providing directly-measured 3D velocity maps. Alternatively, vascular flow can be estimated from model-based computation fluid...... dynamics (CFD) calculations. CFD provides arbitrarily high resolution, but its accuracy hinges on model assumptions, while velocity fields measured with PC-MRI generally do not satisfy the equations of fluid dynamics, provide limited resolution, and suffer from partial volume effects. The purpose...

  1. Computer-assisted three-dimensional surgical planning: 3D virtual articulator: technical note.

    Science.gov (United States)

    Ghanai, S; Marmulla, R; Wiechnik, J; Mühling, J; Kotrikova, B

    2010-01-01

    This study presents a computer-assisted planning system for dysgnathia treatment. It describes the process of information gathering using a virtual articulator and how the splints are constructed for orthognathic surgery. The deviation of the virtually planned splints is shown in six cases on the basis of conventionally planned cases. In all cases the plaster models were prepared and scanned using a 3D laser scanner. Successive lateral and posterior-anterior cephalometric images were used for reconstruction before surgery. By identifying specific points on the X-rays and marking them on the virtual models, it was possible to enhance the 2D images to create a realistic 3D environment and to perform virtual repositioning of the jaw. A hexapod was used to transfer the virtual planning to the real splints. Preliminary results showed that conventional repositioning could be replicated using the virtual articulator.

  2. 3D Massive MIMO Systems: Channel Modeling and Performance Analysis

    KAUST Repository

    Nadeem, Qurrat-Ul-Ain

    2015-03-01

    Multiple-input-multiple-output (MIMO) systems of current LTE releases are capable of adaptation in the azimuth only. More recently, the trend is to enhance the system performance by exploiting the channel\\'s degrees of freedom in the elevation through the dynamic adaptation of the vertical antenna beam pattern. This necessitates the derivation and characterization of three-dimensional (3D) channels. Over the years, channel models have evolved to address the challenges of wireless communication technologies. In parallel to theoretical studies on channel modeling, many standardized channel models like COST-based models, 3GPP SCM, WINNER, ITU have emerged that act as references for industries and telecommunication companies to assess system-level and link-level performances of advanced signal processing techniques over real-like channels. Given the existing channels are only two dimensional (2D) in nature; a large effort in channel modeling is needed to study the impact of the channel component in the elevation direction. The first part of this work sheds light on the current 3GPP activity around 3D channel modeling and beamforming, an aspect that to our knowledge has not been extensively covered by a research publication. The standardized MIMO channel model is presented, that incorporates both the propagation effects of the environment and the radio effects of the antennas. In order to facilitate future studies on the use of 3D beamforming, the main features of the proposed 3D channel model are discussed. A brief overview of the future 3GPP 3D channel model being outlined for the next generation of wireless networks is also provided. In the subsequent part of this work, we present an information-theoretic channel model for MIMO systems that supports the elevation dimension. The model is based on the principle of maximum entropy, which enables us to determine the distribution of the channel matrix consistent with the prior information on the angles of departure and

  3. 3D Finite element analysis of functionally graded multilayered dental ceramic cores.

    Science.gov (United States)

    Al-Maqtari, Ali Abdullah; Razak, Abdul Aziz Abdul; Hamdi, Mohd

    2014-01-01

    This study aimed at investigating and establishing stress distributions in graded multilayered zirconia/alumina ceramic cores and at veneer-core-cement-dentin interfaces, using finite element analysis (FEA), to facilitate the structural design of ceramic cores through computer modeling. An intact maxillary premolar was digitized using CT scanning. An imaging software, Mimics, was used to reconstruct 3D models based on computed tomography (CT) data saved in DICOM format. Eight different 3D models were created for FEA, where each 3D model was meshed and its bottom boundaries constrained. A static load was applied in the oblique direction. The materials were assumed to be isotropic and homogeneous. Highest von Mises stress values were found in areas directly below the load application point, and stress gradually decreased in occlusal loading direction from the external surface toward the dentin. Stress levels occurring at veneer-ceramic core-cement-dentin interfaces were shown to be lower in multilayered ceramic cores than in single-layer models.

  4. Customisable 3D printed microfluidics for integrated analysis and optimisation.

    Science.gov (United States)

    Monaghan, T; Harding, M J; Harris, R A; Friel, R J; Christie, S D R

    2016-08-16

    The formation of smart Lab-on-a-Chip (LOC) devices featuring integrated sensing optics is currently hindered by convoluted and expensive manufacturing procedures. In this work, a series of 3D-printed LOC devices were designed and manufactured via stereolithography (SL) in a matter of hours. The spectroscopic performance of a variety of optical fibre combinations were tested, and the optimum path length for performing Ultraviolet-visible (UV-vis) spectroscopy determined. The information gained in these trials was then used in a reaction optimisation for the formation of carvone semicarbazone. The production of high resolution surface channels (100-500 μm) means that these devices were capable of handling a wide range of concentrations (9 μM-38 mM), and are ideally suited to both analyte detection and process optimisation. This ability to tailor the chip design and its integrated features as a direct result of the reaction being assessed, at such a low time and cost penalty greatly increases the user's ability to optimise both their device and reaction. As a result of the information gained in this investigation, we are able to report the first instance of a 3D-printed LOC device with fully integrated, in-line monitoring capabilities via the use of embedded optical fibres capable of performing UV-vis spectroscopy directly inside micro channels.

  5. Metrological analysis of the human foot: 3D multisensor exploration

    Science.gov (United States)

    Muñoz Potosi, A.; Meneses Fonseca, J.; León Téllez, J.

    2011-08-01

    In the podiatry field, many of the foot dysfunctions are mainly generated due to: Congenital malformations, accidents or misuse of footwear. For the treatment or prevention of foot disorders, the podiatrist diagnoses prosthesis or specific adapted footwear, according to the real dimension of foot. Therefore, it is necessary to acquire 3D information of foot with 360 degrees of observation. As alternative solution, it was developed and implemented an optical system of threedimensional reconstruction based in the principle of laser triangulation. The system is constituted by an illumination unit that project a laser plane into the foot surface, an acquisition unit with 4 CCD cameras placed around of axial foot axis, an axial moving unit that displaces the illumination and acquisition units in the axial axis direction and a processing and exploration unit. The exploration software allows the extraction of distances on three-dimensional image, taking into account the topography of foot. The optical system was tested and their metrological performances were evaluated in experimental conditions. The optical system was developed to acquire 3D information in order to design and make more appropriate footwear.

  6. Quantitative analysis of spinal curvature in 3D: application to CT images of normal spine

    Energy Technology Data Exchange (ETDEWEB)

    Vrtovec, Tomaz; Likar, Bostjan; Pernus, Franjo [University of Ljubljana, Faculty of Electrical Engineering, Trzaska 25, SI-1000 Ljubljana (Slovenia)], E-mail: tomaz.vrtovec@fe.uni-lj.si, E-mail: bostjan.likar@fe.uni-lj.si, E-mail: franjo.pernus@fe.uni-lj.si

    2008-04-07

    The purpose of this study is to present a framework for quantitative analysis of spinal curvature in 3D. In order to study the properties of such complex 3D structures, we propose two descriptors that capture the characteristics of spinal curvature in 3D. The descriptors are the geometric curvature (GC) and curvature angle (CA), which are independent of the orientation and size of spine anatomy. We demonstrate the two descriptors that characterize the spinal curvature in 3D on 30 computed tomography (CT) images of normal spine and on a scoliotic spine. The descriptors are determined from 3D vertebral body lines, which are obtained by two different methods. The first method is based on the least-squares technique that approximates the manually identified vertebra centroids, while the second method searches for vertebra centroids in an automated optimization scheme, based on computer-assisted image analysis. Polynomial functions of the fourth and fifth degree were used for the description of normal and scoliotic spinal curvature in 3D, respectively. The mean distance to vertebra centroids was 1.1 mm ({+-}0.6 mm) for the first and 2.1 mm ({+-}1.4 mm) for the second method. The distributions of GC and CA values were obtained along the 30 images of normal spine at each vertebral level and show that maximal thoracic kyphosis (TK), thoracolumbar junction (TJ) and maximal lumbar lordosis (LL) on average occur at T3/T4, T12/L1 and L4/L5, respectively. The main advantage of GC and CA is that the measurements are independent of the orientation and size of the spine, thus allowing objective intra- and inter-subject comparisons. The positions of maximal TK, TJ and maximal LL can be easily identified by observing the GC and CA distributions at different vertebral levels. The obtained courses of the GC and CA for the scoliotic spine were compared to the distributions of GC and CA for the normal spines. The significant difference in values indicates that the descriptors of GC and

  7. Quantitative analysis of spinal curvature in 3D: application to CT images of normal spine.

    Science.gov (United States)

    Vrtovec, Tomaz; Likar, Bostjan; Pernus, Franjo

    2008-04-07

    The purpose of this study is to present a framework for quantitative analysis of spinal curvature in 3D. In order to study the properties of such complex 3D structures, we propose two descriptors that capture the characteristics of spinal curvature in 3D. The descriptors are the geometric curvature (GC) and curvature angle (CA), which are independent of the orientation and size of spine anatomy. We demonstrate the two descriptors that characterize the spinal curvature in 3D on 30 computed tomography (CT) images of normal spine and on a scoliotic spine. The descriptors are determined from 3D vertebral body lines, which are obtained by two different methods. The first method is based on the least-squares technique that approximates the manually identified vertebra centroids, while the second method searches for vertebra centroids in an automated optimization scheme, based on computer-assisted image analysis. Polynomial functions of the fourth and fifth degree were used for the description of normal and scoliotic spinal curvature in 3D, respectively. The mean distance to vertebra centroids was 1.1 mm (+/-0.6 mm) for the first and 2.1 mm (+/-1.4 mm) for the second method. The distributions of GC and CA values were obtained along the 30 images of normal spine at each vertebral level and show that maximal thoracic kyphosis (TK), thoracolumbar junction (TJ) and maximal lumbar lordosis (LL) on average occur at T3/T4, T12/L1 and L4/L5, respectively. The main advantage of GC and CA is that the measurements are independent of the orientation and size of the spine, thus allowing objective intra- and inter-subject comparisons. The positions of maximal TK, TJ and maximal LL can be easily identified by observing the GC and CA distributions at different vertebral levels. The obtained courses of the GC and CA for the scoliotic spine were compared to the distributions of GC and CA for the normal spines. The significant difference in values indicates that the descriptors of GC and CA

  8. Importance of a 3D forward modeling tool for surface wave analysis methods

    Science.gov (United States)

    Pageot, Damien; Le Feuvre, Mathieu; Donatienne, Leparoux; Philippe, Côte; Yann, Capdeville

    2016-04-01

    Since a few years, seismic surface waves analysis methods (SWM) have been widely developed and tested in the context of subsurface characterization and have demonstrated their effectiveness for sounding and monitoring purposes, e.g., high-resolution tomography of the principal geological units of California or real time monitoring of the Piton de la Fournaise volcano. Historically, these methods are mostly developed under the assumption of semi-infinite 1D layered medium without topography. The forward modeling is generally based on Thomson-Haskell matrix based modeling algorithm and the inversion is driven by Monte-Carlo sampling. Given their efficiency, SWM have been transfered to several scale of which civil engineering structures in order to, e.g., determine the so-called V s30 parameter or assess other critical constructional parameters in pavement engineering. However, at this scale, many structures may often exhibit 3D surface variations which drastically limit the efficiency of SWM application. Indeed, even in the case of an homogeneous structure, 3D geometry can bias the dispersion diagram of Rayleigh waves up to obtain discontinuous phase velocity curves which drastically impact the 1D mean velocity model obtained from dispersion inversion. Taking advantages of high-performance computing center accessibility and wave propagation modeling algorithm development, it is now possible to consider the use of a 3D elastic forward modeling algorithm instead of Thomson-Haskell method in the SWM inversion process. We use a parallelized 3D elastic modeling code based on the spectral element method which allows to obtain accurate synthetic data with very low numerical dispersion and a reasonable numerical cost. In this study, we choose dike embankments as an illustrative example. We first show that their longitudinal geometry may have a significant effect on dispersion diagrams of Rayleigh waves. Then, we demonstrate the necessity of 3D elastic modeling as a forward

  9. Using 2D and 3D Computer Games to Detect Colorblindness – a Comparative Study

    Directory of Open Access Journals (Sweden)

    Laskowski Maciej

    2015-12-01

    Full Text Available Computer games have accompanied the development of computer technologies since the very beginning. Despite their basic, purely entertainment-targeted appliance, games can also be used for many other purposes. Medical applications are especially interesting, as games (especially different kinds of simulations are widely used for training personnel, e.g. to perform certain procedures or in learning to use equipment. This allows the trainees to gain knowledge and proper habits, as well as test themselves in different situations without any risk. Computer games can also be used as a diagnostic tool, although this topic is still insufficiently researched. This paper discusses the possibility of using serious games for diagnosing color vision disorders, focusing especially on two problems: differences in diagnosing colorblindness using 2D and 3D environments, and the influence of individual features, such as reflex or agility, on the diagnostic process.

  10. Generic camera model and its calibration for computational integral imaging and 3D reconstruction.

    Science.gov (United States)

    Li, Weiming; Li, Youfu

    2011-03-01

    Integral imaging (II) is an important 3D imaging technology. To reconstruct 3D information of the viewed objects, modeling and calibrating the optical pickup process of II are necessary. This work focuses on the modeling and calibration of an II system consisting of a lenslet array, an imaging lens, and a charge-coupled device camera. Most existing work on such systems assumes a pinhole array model (PAM). In this work, we explore a generic camera model that accommodates more generality. This model is an empirical model based on measurements, and we constructed a setup for its calibration. Experimental results show a significant difference between the generic camera model and the PAM. Images of planar patterns and 3D objects were computationally reconstructed with the generic camera model. Compared with the images reconstructed using the PAM, the images present higher fidelity and preserve more high spatial frequency components. To the best of our knowledge, this is the first attempt in applying a generic camera model to an II system.

  11. Fractographic classification in metallic materials by using 3D processing and computer vision techniques

    Directory of Open Access Journals (Sweden)

    Maria Ximena Bastidas-Rodríguez

    2016-09-01

    Full Text Available Failure analysis aims at collecting information about how and why a failure is produced. The first step in this process is a visual inspection on the flaw surface that will reveal the features, marks, and texture, which characterize each type of fracture. This is generally carried out by personnel with no experience that usually lack the knowledge to do it. This paper proposes a classification method for three kinds of fractures in crystalline materials: brittle, fatigue, and ductile. The method uses 3D vision, and it is expected to support failure analysis. The features used in this work were: i Haralick’s features and ii the fractal dimension. These features were applied to 3D images obtained from a confocal laser scanning microscopy Zeiss LSM 700. For the classification, we evaluated two classifiers: Artificial Neural Networks and Support Vector Machine. The performance evaluation was made by extracting four marginal relations from the confusion matrix: accuracy, sensitivity, specificity, and precision, plus three evaluation methods: Receiver Operating Characteristic space, the Individual Classification Success Index, and the Jaccard’s coefficient. Despite the classification percentage obtained by an expert is better than the one obtained with the algorithm, the algorithm achieves a classification percentage near or exceeding the 60 % accuracy for the analyzed failure modes. The results presented here provide a good approach to address future research on texture analysis using 3D data.

  12. Stiffness Analysis of 3-d.o.f. Overconstrained Translational Parallel Manipulators

    CERN Document Server

    Pashkevich, Anatoly; Wenger, Philippe

    2008-01-01

    The paper presents a new stiffness modelling method for overconstrained parallel manipulators, which is applied to 3-d.o.f. translational mechanisms. It is based on a multidimensional lumped-parameter model that replaces the link flexibility by localized 6-d.o.f. virtual springs. In contrast to other works, the method includes a FEA-based link stiffness evaluation and employs a new solution strategy of the kinetostatic equations, which allows computing the stiffness matrix for the overconstrained architectures and for the singular manipulator postures. The advantages of the developed technique are confirmed by application examples, which deal with comparative stiffness analysis of two translational parallel manipulators.

  13. The history of visual magic in computers how beautiful images are made in CAD, 3D, VR and AR

    CERN Document Server

    Peddie, Jon

    2013-01-01

    If you have ever looked at a fantastic adventure or science fiction movie, or an amazingly complex and rich computer game, or a TV commercial where cars or gas pumps or biscuits behaved liked people and wondered, ""How do they do that?"",  then you've experienced the magic of 3D worlds generated by a computer.3D in computers began as a way to represent automotive designs and illustrate the construction of molecules. 3D graphics use evolved to visualizations of simulated data and artistic representations of imaginary worlds. In order to overcome the processing limitations of the computer, graph

  14. A stabilized complementarity formulation for nonlinear analysis of 3D bimodular materials

    Science.gov (United States)

    Zhang, L.; Zhang, H. W.; Wu, J.; Yan, B.

    2016-06-01

    Bi-modulus materials with different mechanical responses in tension and compression are often found in civil, composite, and biological engineering. Numerical analysis of bimodular materials is strongly nonlinear and convergence is usually a problem for traditional iterative schemes. This paper aims to develop a stabilized computational method for nonlinear analysis of 3D bimodular materials. Based on the parametric variational principle, a unified constitutive equation of 3D bimodular materials is proposed, which allows the eight principal stress states to be indicated by three parametric variables introduced in the principal stress directions. The original problem is transformed into a standard linear complementarity problem (LCP) by the parametric virtual work principle and a quadratic programming algorithm is developed by solving the LCP with the classic Lemke's algorithm. Update of elasticity and stiffness matrices is avoided and, thus, the proposed algorithm shows an excellent convergence behavior compared with traditional iterative schemes. Numerical examples show that the proposed method is valid and can accurately analyze mechanical responses of 3D bimodular materials. Also, stability of the algorithm is greatly improved.

  15. 3D object-oriented image analysis in 3D geophysical modelling: Analysing the central part of the East African Rift System

    Science.gov (United States)

    Fadel, I.; van der Meijde, M.; Kerle, N.; Lauritsen, N.

    2015-03-01

    Non-uniqueness of satellite gravity interpretation has traditionally been reduced by using a priori information from seismic tomography models. This reduction in the non-uniqueness has been based on velocity-density conversion formulas or user interpretation of the 3D subsurface structures (objects) based on the seismic tomography models and then forward modelling these objects. However, this form of object-based approach has been done without a standardized methodology on how to extract the subsurface structures from the 3D models. In this research, a 3D object-oriented image analysis (3D OOA) approach was implemented to extract the 3D subsurface structures from geophysical data. The approach was applied on a 3D shear wave seismic tomography model of the central part of the East African Rift System. Subsequently, the extracted 3D objects from the tomography model were reconstructed in the 3D interactive modelling environment IGMAS+, and their density contrast values were calculated using an object-based inversion technique to calculate the forward signal of the objects and compare it with the measured satellite gravity. Thus, a new object-based approach was implemented to interpret and extract the 3D subsurface objects from 3D geophysical data. We also introduce a new approach to constrain the interpretation of the satellite gravity measurements that can be applied using any 3D geophysical model.

  16. Analysis of 3-D Frictional Contact Mechanics Problems by a Boundary Element Method

    Institute of Scientific and Technical Information of China (English)

    KEUM Bangyong; LIU Yijun

    2005-01-01

    The development of two boundary element algorithms for solving 3-D, frictional, and linear elastostatic contact problems is reported in this paper. The algorithms employ nonconforming discretizations for solving 3-D boundary element models, which provide much needed flexibility in the boundary element modeling for 3-D contact problems. These algorithms are implemented in a new 3-D boundary element code and verified using several examples. For the numerical examples studied, the results using the new boundary element algorithms match very well with the results using a commercial finite element code, and clearly demonstrate the feasibility of the new boundary element approach for 3-D contact analysis.

  17. An approximate 3D computational method for real-time computation of induction logging responses

    NARCIS (Netherlands)

    Bensdorp, S.; Petersen, S.A.; Van den Berg, P.M.; Fokkema, J.T.

    2014-01-01

    Over many years, induction logging systems have been used to create well formation logs. The major drawback for the utilization of these tools is the long simulation time for a single forward computation. We proposed an efficient computational method based on a contrast-type of integral-equation for

  18. 3D virtual human atria: A computational platform for studying clinical atrial fibrillation.

    Science.gov (United States)

    Aslanidi, Oleg V; Colman, Michael A; Stott, Jonathan; Dobrzynski, Halina; Boyett, Mark R; Holden, Arun V; Zhang, Henggui

    2011-10-01

    Despite a vast amount of experimental and clinical data on the underlying ionic, cellular and tissue substrates, the mechanisms of common atrial arrhythmias (such as atrial fibrillation, AF) arising from the functional interactions at the whole atria level remain unclear. Computational modelling provides a quantitative framework for integrating such multi-scale data and understanding the arrhythmogenic behaviour that emerges from the collective spatio-temporal dynamics in all parts of the heart. In this study, we have developed a multi-scale hierarchy of biophysically detailed computational models for the human atria--the 3D virtual human atria. Primarily, diffusion tensor MRI reconstruction of the tissue geometry and fibre orientation in the human sinoatrial node (SAN) and surrounding atrial muscle was integrated into the 3D model of the whole atria dissected from the Visible Human dataset. The anatomical models were combined with the heterogeneous atrial action potential (AP) models, and used to simulate the AP conduction in the human atria under various conditions: SAN pacemaking and atrial activation in the normal rhythm, break-down of regular AP wave-fronts during rapid atrial pacing, and the genesis of multiple re-entrant wavelets characteristic of AF. Contributions of different properties of the tissue to mechanisms of the normal rhythm and arrhythmogenesis were investigated. Primarily, the simulations showed that tissue heterogeneity caused the break-down of the normal AP wave-fronts at rapid pacing rates, which initiated a pair of re-entrant spiral waves; and tissue anisotropy resulted in a further break-down of the spiral waves into multiple meandering wavelets characteristic of AF. The 3D virtual atria model itself was incorporated into the torso model to simulate the body surface ECG patterns in the normal and arrhythmic conditions. Therefore, a state-of-the-art computational platform has been developed, which can be used for studying multi

  19. 3D TRANSIENT COUPLED THERMO-ELASTIC-PLASTIC CONTACT SEALING ANALYSIS OF REACTOR PRESSURE VESSEL

    Institute of Scientific and Technical Information of China (English)

    Du Xuesong; Li Runfang; Lin Tengjiao

    2005-01-01

    Sealing analysis of sealing system in reactor pressure vessels is relevant with multiple nonlinear coupled-field effects, so even large-scale commercial finite element software cannot finish the complicated analysis. A fmite element method of 3D transient coupled thermo-elastic-plastic contact sealing analysis for reactor pressure vessels is presented, in which the surface nonlinearity,material nonlinearity, transient heat transfer nonlinearity and multiple coupled effect are taken into account and the sealing equation is coupling solved in iterative procedure. At the same time, a computational analysis program is developed, which is applied in the sealing analysis of experimental reactor pressure vessel, and the numerical results are in good coincidence with the experimental results. This program is also successful in analyzing the practical problem in engineering.

  20. Quick, Accurate, Smart: 3D Computer Vision Technology Helps Assessing Confined Animals' Behaviour.

    Science.gov (United States)

    Barnard, Shanis; Calderara, Simone; Pistocchi, Simone; Cucchiara, Rita; Podaliri-Vulpiani, Michele; Messori, Stefano; Ferri, Nicola

    2016-01-01

    Mankind directly controls the environment and lifestyles of several domestic species for purposes ranging from production and research to conservation and companionship. These environments and lifestyles may not offer these animals the best quality of life. Behaviour is a direct reflection of how the animal is coping with its environment. Behavioural indicators are thus among the preferred parameters to assess welfare. However, behavioural recording (usually from video) can be very time consuming and the accuracy and reliability of the output rely on the experience and background of the observers. The outburst of new video technology and computer image processing gives the basis for promising solutions. In this pilot study, we present a new prototype software able to automatically infer the behaviour of dogs housed in kennels from 3D visual data and through structured machine learning frameworks. Depth information acquired through 3D features, body part detection and training are the key elements that allow the machine to recognise postures, trajectories inside the kennel and patterns of movement that can be later labelled at convenience. The main innovation of the software is its ability to automatically cluster frequently observed temporal patterns of movement without any pre-set ethogram. Conversely, when common patterns are defined through training, a deviation from normal behaviour in time or between individuals could be assessed. The software accuracy in correctly detecting the dogs' behaviour was checked through a validation process. An automatic behaviour recognition system, independent from human subjectivity, could add scientific knowledge on animals' quality of life in confinement as well as saving time and resources. This 3D framework was designed to be invariant to the dog's shape and size and could be extended to farm, laboratory and zoo quadrupeds in artificial housing. The computer vision technique applied to this software is innovative in non

  1. Quick, Accurate, Smart: 3D Computer Vision Technology Helps Assessing Confined Animals' Behaviour.

    Directory of Open Access Journals (Sweden)

    Shanis Barnard

    Full Text Available Mankind directly controls the environment and lifestyles of several domestic species for purposes ranging from production and research to conservation and companionship. These environments and lifestyles may not offer these animals the best quality of life. Behaviour is a direct reflection of how the animal is coping with its environment. Behavioural indicators are thus among the preferred parameters to assess welfare. However, behavioural recording (usually from video can be very time consuming and the accuracy and reliability of the output rely on the experience and background of the observers. The outburst of new video technology and computer image processing gives the basis for promising solutions. In this pilot study, we present a new prototype software able to automatically infer the behaviour of dogs housed in kennels from 3D visual data and through structured machine learning frameworks. Depth information acquired through 3D features, body part detection and training are the key elements that allow the machine to recognise postures, trajectories inside the kennel and patterns of movement that can be later labelled at convenience. The main innovation of the software is its ability to automatically cluster frequently observed temporal patterns of movement without any pre-set ethogram. Conversely, when common patterns are defined through training, a deviation from normal behaviour in time or between individuals could be assessed. The software accuracy in correctly detecting the dogs' behaviour was checked through a validation process. An automatic behaviour recognition system, independent from human subjectivity, could add scientific knowledge on animals' quality of life in confinement as well as saving time and resources. This 3D framework was designed to be invariant to the dog's shape and size and could be extended to farm, laboratory and zoo quadrupeds in artificial housing. The computer vision technique applied to this software is

  2. Quick, Accurate, Smart: 3D Computer Vision Technology Helps Assessing Confined Animals’ Behaviour

    Science.gov (United States)

    Calderara, Simone; Pistocchi, Simone; Cucchiara, Rita; Podaliri-Vulpiani, Michele; Messori, Stefano; Ferri, Nicola

    2016-01-01

    Mankind directly controls the environment and lifestyles of several domestic species for purposes ranging from production and research to conservation and companionship. These environments and lifestyles may not offer these animals the best quality of life. Behaviour is a direct reflection of how the animal is coping with its environment. Behavioural indicators are thus among the preferred parameters to assess welfare. However, behavioural recording (usually from video) can be very time consuming and the accuracy and reliability of the output rely on the experience and background of the observers. The outburst of new video technology and computer image processing gives the basis for promising solutions. In this pilot study, we present a new prototype software able to automatically infer the behaviour of dogs housed in kennels from 3D visual data and through structured machine learning frameworks. Depth information acquired through 3D features, body part detection and training are the key elements that allow the machine to recognise postures, trajectories inside the kennel and patterns of movement that can be later labelled at convenience. The main innovation of the software is its ability to automatically cluster frequently observed temporal patterns of movement without any pre-set ethogram. Conversely, when common patterns are defined through training, a deviation from normal behaviour in time or between individuals could be assessed. The software accuracy in correctly detecting the dogs’ behaviour was checked through a validation process. An automatic behaviour recognition system, independent from human subjectivity, could add scientific knowledge on animals’ quality of life in confinement as well as saving time and resources. This 3D framework was designed to be invariant to the dog’s shape and size and could be extended to farm, laboratory and zoo quadrupeds in artificial housing. The computer vision technique applied to this software is innovative in non

  3. 3D modeling method for computer animate based on modified weak structured light method

    Science.gov (United States)

    Xiong, Hanwei; Pan, Ming; Zhang, Xiangwei

    2010-11-01

    A simple and affordable 3D scanner is designed in this paper. Three-dimensional digital models are playing an increasingly important role in many fields, such as computer animate, industrial design, artistic design and heritage conservation. For many complex shapes, optical measurement systems are indispensable to acquiring the 3D information. In the field of computer animate, such an optical measurement device is too expensive to be widely adopted, and on the other hand, the precision is not as critical a factor in that situation. In this paper, a new cheap 3D measurement system is implemented based on modified weak structured light, using only a video camera, a light source and a straight stick rotating on a fixed axis. For an ordinary weak structured light configuration, one or two reference planes are required, and the shadows on these planes must be tracked in the scanning process, which destroy the convenience of this method. In the modified system, reference planes are unnecessary, and size range of the scanned objects is expanded widely. A new calibration procedure is also realized for the proposed method, and points cloud is obtained by analyzing the shadow strips on the object. A two-stage ICP algorithm is used to merge the points cloud from different viewpoints to get a full description of the object, and after a series of operations, a NURBS surface model is generated in the end. A complex toy bear is used to verify the efficiency of the method, and errors range from 0.7783mm to 1.4326mm comparing with the ground truth measurement.

  4. 3D thermo-chemical-mechanical analysis of the pultrusion process

    DEFF Research Database (Denmark)

    Baran, Ismet; Hattel, Jesper Henri; Tutum, Cem C.

    2013-01-01

    In the present study, a 3D Eulerian thermo-chemical analysis is sequentially coupled with a 3D Lagrangian quasi static mechanical analysis of the pultrusion process. The temperature and degree of cure profiles at the steady state are first calculated in the thermo-chemical analysis...

  5. 3D-Ultrasound probe calibration for computer-guided diagnosis and therapy

    CERN Document Server

    Baumann, Michael; Leroy, Antoine; Troccaz, Jocelyne

    2008-01-01

    With the emergence of swept-volume ultrasound (US) probes, precise and almost real-time US volume imaging has become available. This offers many new opportunities for computer guided diagnosis and therapy, 3-D images containing significantly more information than 2-D slices. However, computer guidance often requires knowledge about the exact position of US voxels relative to a tracking reference, which can only be achieved through probe calibration. In this paper we present a 3-D US probe calibration system based on a membrane phantom. The calibration matrix is retrieved by detection of a membrane plane in a dozen of US acquisitions of the phantom. Plane detection is robustly performed with the 2-D Hough transformation. The feature extraction process is fully automated, calibration requires about 20 minutes and the calibration system can be used in a clinical context. The precision of the system was evaluated to a root mean square (RMS) distance error of 1.15mm and to an RMS angular error of 0.61 degrees. The...

  6. Compute extremely low-frequency electromagnetic field exposure by 3-D impendance method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A 3-D impedance method has been introduced to compute the electric currents induced in a human body exposed to extremely low-frequency electromagnetic field.The 3-D impedance method has been deduced from Maxwell equations and is put into the computation and simulation effectively to the visible human body model, which has 196×114×626 cells and more than 40 types of tissues.As the result, two representative cases are investigated.One is exposure of the human body to 100 μT (1 000 mG), the limit recommended by the International Commission on Non-Ionizing Radiation Protection for the public and the other one is the exposure of human body to 0.4 μT (4 mG), the level at which a statistical link appears with a doubled risk of development of childhood leukaemia.The distribution of induced current density can be obtained and the maximum of induced current are found to be 16 mA/m2 and 0.07 mA/m2.

  7. FaceWarehouse: a 3D facial expression database for visual computing.

    Science.gov (United States)

    Cao, Chen; Weng, Yanlin; Zhou, Shun; Tong, Yiying; Zhou, Kun

    2014-03-01

    We present FaceWarehouse, a database of 3D facial expressions for visual computing applications. We use Kinect, an off-the-shelf RGBD camera, to capture 150 individuals aged 7-80 from various ethnic backgrounds. For each person, we captured the RGBD data of her different expressions, including the neutral expression and 19 other expressions such as mouth-opening, smile, kiss, etc. For every RGBD raw data record, a set of facial feature points on the color image such as eye corners, mouth contour, and the nose tip are automatically localized, and manually adjusted if better accuracy is required. We then deform a template facial mesh to fit the depth data as closely as possible while matching the feature points on the color image to their corresponding points on the mesh. Starting from these fitted face meshes, we construct a set of individual-specific expression blendshapes for each person. These meshes with consistent topology are assembled as a rank-3 tensor to build a bilinear face model with two attributes: identity and expression. Compared with previous 3D facial databases, for every person in our database, there is a much richer matching collection of expressions, enabling depiction of most human facial actions. We demonstrate the potential of FaceWarehouse for visual computing with four applications: facial image manipulation, face component transfer, real-time performance-based facial image animation, and facial animation retargeting from video to image.

  8. Fast computation of scattering from 3D complex structures by MLFMA

    Institute of Scientific and Technical Information of China (English)

    Hu Jun; Nie Zaiping; Que Xiaofeng; Meng Min

    2008-01-01

    This paper introduces the research work on the extension of multilevel fast multipole algorithm (MLFMA) to 3D complex structures including coating object,thin dielectric sheet,composite dielectric and conductor,cavity.The impedance boundary condition is used for scattering from the object coated by thin lossy material.Instead of volume integral equation,surface integral equation is applied in case of thin dielectric sheet through resistive sheet boundary condition.To realize the fast computation of scattering from composite homogeneous dielectric and conductor,the surface integral equation based on equivalence principle is used.Compared with the traditional volume integral equation,the surface integral equation reduces greatly the number of unknowns.To compute conducting cavity with electrically large aperture,an electric field integral equation is applied.Some numerical results are given to demonstrate the validity and accuracy of the present methods.

  9. Applying 3D measurements and computer matching algorithms to two firearm examination proficiency tests.

    Science.gov (United States)

    Ott, Daniel; Thompson, Robert; Song, Junfeng

    2017-02-01

    In order for a crime laboratory to assess a firearms examiner's training, skills, experience, and aptitude, it is necessary for the examiner to participate in proficiency testing. As computer algorithms for comparisons of pattern evidence become more prevalent, it is of interest to test algorithm performance as well, using these same proficiency examinations. This article demonstrates the use of the Congruent Matching Cell (CMC) algorithm to compare 3D topography measurements of breech face impressions and firing pin impressions from a previously distributed firearms proficiency test. In addition, the algorithm is used to analyze the distribution of many comparisons from a collection of cartridge cases used to construct another recent set of proficiency tests. These results are provided along with visualizations that help to relate the features used in optical comparisons by examiners to the features used by computer comparison algorithms.

  10. A review of automated image understanding within 3D baggage computed tomography security screening.

    Science.gov (United States)

    Mouton, Andre; Breckon, Toby P

    2015-01-01

    Baggage inspection is the principal safeguard against the transportation of prohibited and potentially dangerous materials at airport security checkpoints. Although traditionally performed by 2D X-ray based scanning, increasingly stringent security regulations have led to a growing demand for more advanced imaging technologies. The role of X-ray Computed Tomography is thus rapidly expanding beyond the traditional materials-based detection of explosives. The development of computer vision and image processing techniques for the automated understanding of 3D baggage-CT imagery is however, complicated by poor image resolutions, image clutter and high levels of noise and artefacts. We discuss the recent and most pertinent advancements and identify topics for future research within the challenging domain of automated image understanding for baggage security screening CT.

  11. DYNA3D analysis of the DT-20 shipping container

    Energy Technology Data Exchange (ETDEWEB)

    Logan, R.W.; Lovejoy, S.C.

    1991-08-22

    A DYNA3D model of the DT-20 shipping container was constructed. Impact onto a rigid steel surface at a velocity of 44 ft/sec (30 foot gravity drop) was studied. The orientation of most interest was a side-drop, but end and corner drops were also studied briefly. The assembly for the baseline side impact contained a 150 lb. payload. During this drop, the outer drum sustains plastic strains of up to 0.15, with most the deformation near the rim. The plywood/Celotex packing is crushed about 3 inches. The inner sealed can sees significant stresses, but barely reaches the onset of yielding in some local areas. Based on hand calculations, the bolts joining the can halves could see stresses near 50 ksi. It is felt that overall, the container should survive this drop. However, detailed modeling of the rim closure and the center bolted joint was not possible due to time constraints. Furthermore, better material models and properties are needed for the Celotex, plywood, and honeycomb in particular. 39 figs., 1 tab.

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

    Science.gov (United States)

    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…

  13. Modeling and validation of a 3D premolar for finite element analysis

    Directory of Open Access Journals (Sweden)

    Letícia Brandão DURAND

    Full Text Available Abstract Introduction The development and validation of mathematical models is an important step of the methodology of finite element studies. Objective This study aims to describe the development and validation of a three-dimensional numerical model of a maxillary premolar for finite element analysis. Material and method The 3D model was based on standardized photographs of sequential slices of an intact premolar and generated with the use of SolidWorks Software (Dassault, France. In order to validate the model, compression and numerical tests were performed. The load versus displacement graphs of both tests were visually compared, the percentage of error calculated and homogeneity of regression coefficients tested. Result An accurate 3D model was developed and validated since the graphs were visually similar, the percentage error was within acceptable limits, and the straight lines were considered parallel. Conclusion The modeling procedures and validation described allows the development of accurate 3D dental models with biomechanical behavior similar to natural teeth. The methods may be applied in development and validation of new models and computer-aided simulations using FEM.

  14. Reconstruction Accuracy Assessment of Surface and Underwater 3D Motion Analysis: A New Approach

    Directory of Open Access Journals (Sweden)

    Kelly de Jesus

    2015-01-01

    Full Text Available This study assessed accuracy of surface and underwater 3D reconstruction of a calibration volume with and without homography. A calibration volume (6000 × 2000 × 2500 mm with 236 markers (64 above and 88 underwater control points—with 8 common points at water surface—and 92 validation points was positioned on a 25 m swimming pool and recorded with two surface and four underwater cameras. Planar homography estimation for each calibration plane was computed to perform image rectification. Direct linear transformation algorithm for 3D reconstruction was applied, using 1600000 different combinations of 32 and 44 points out of the 64 and 88 control points for surface and underwater markers (resp.. Root Mean Square (RMS error with homography of control and validations points was lower than without it for surface and underwater cameras (P≤0.03. With homography, RMS errors of control and validation points were similar between surface and underwater cameras (P≥0.47. Without homography, RMS error of control points was greater for underwater than surface cameras (P≤0.04 and the opposite was observed for validation points (P≤0.04. It is recommended that future studies using 3D reconstruction should include homography to improve swimming movement analysis accuracy.

  15. 3D DIRECTIONAL MATHEMATICAL MORPHOLOGY FOR ANALYSIS OF FIBER ORIENTATIONS

    Directory of Open Access Journals (Sweden)

    Hellen Altendorf

    2011-05-01

    Full Text Available In this paper we present algorithms for measuring local characteristics of random fiber systems. The calculation of the local directions and radii is based on directional distance transforms and evaluation of the inertia moments and axes of the resulting extremities of the centralized, directed chords. The method provides continuous results while minimizing the runtime by using few sampled directions. Furthermore several steps of improvement for the computation of orientation and radius information are presented. The algorithms are evaluated using synthetic data and applied to images of realmicrostructures obtained by computer tomography.

  16. Simulation of engine cooling with coupled 1D and 3D flow computation; Simulation der Motorkuehlung mit Hilfe gekoppelter 1D- und 3D-Stroemungsberechnung

    Energy Technology Data Exchange (ETDEWEB)

    Grafenberger, P.; Klinner, P.; Nefischer, P. [BMW Motoren GmbH, Steyr (Austria); Klingebiel, F. [AMSTRAL Engineering fuer Stroemungsmechanik GmbH, Idstein (Germany)

    2000-04-01

    Shorting the development time for new engines and vehicles is leading to the increasing use of computational design and simulation methods in the automotive industry. For several years now, both one-dimensional and three-dimensional flow computation have been used successfully in the development of cooling systems. However, the fact that less hardware is used in the early development stages makes new demands on the quality and quantity of these simulation results. BMW's diesel development division has been able to improve the quality of the results and to reduce the processing time by improving the model quality and by coupling existing 1D and 3D computational fluid dynamic programmes. (orig.) [German] Die Verkuerzung der Entwicklungszeit neuer Motoren und Automobile fuehrt zu einem verstaerkten Einsatz von rechnergestuetzten Konstruktions- und Simulationsmethoden in der Fahrzeugindustrie. Sowohl eindimensionale als auch dreidimensionale Stroemungsberechnungen werden seit Jahren erfolgreich bei der Entwicklung von Kuehlsystemen eingesetzt. Der Entfall von Hardware-Baugruppen in der fruehen Entwicklungsphase stellt jedoch neue Anforderungen an die Qualitaet und Quantitaet dieser Simulationsergebnisse. Durch Verbesserung der Modellqualitaet und durch Kopplung vorhandener 1D- und 3D-Stroemungsberechnungsprogramme konnten in der Dieselmotorenentwicklung von BMW die Qualitaet der Ergebnisse und die Bearbeitungsgeschwindigkeit deutlich gesteigert werden. (orig.)

  17. "Let's get physical": advantages of a physical model over 3D computer models and textbooks in learning imaging anatomy.

    Science.gov (United States)

    Preece, Daniel; Williams, Sarah B; Lam, Richard; Weller, Renate

    2013-01-01

    Three-dimensional (3D) information plays an important part in medical and veterinary education. Appreciating complex 3D spatial relationships requires a strong foundational understanding of anatomy and mental 3D visualization skills. Novel learning resources have been introduced to anatomy training to achieve this. Objective evaluation of their comparative efficacies remains scarce in the literature. This study developed and evaluated the use of a physical model in demonstrating the complex spatial relationships of the equine foot. It was hypothesized that the newly developed physical model would be more effective for students to learn magnetic resonance imaging (MRI) anatomy of the foot than textbooks or computer-based 3D models. Third year veterinary medicine students were randomly assigned to one of three teaching aid groups (physical model; textbooks; 3D computer model). The comparative efficacies of the three teaching aids were assessed through students' abilities to identify anatomical structures on MR images. Overall mean MRI assessment scores were significantly higher in students utilizing the physical model (86.39%) compared with students using textbooks (62.61%) and the 3D computer model (63.68%) (P computer model groups (P = 0.685). Student feedback was also more positive in the physical model group compared with both the textbook and 3D computer model groups. Our results suggest that physical models may hold a significant advantage over alternative learning resources in enhancing visuospatial and 3D understanding of complex anatomical architecture, and that 3D computer models have significant limitations with regards to 3D learning.

  18. Segmentation process significantly influences the accuracy of 3D surface models derived from cone beam computed tomography

    NARCIS (Netherlands)

    Fourie, Zacharias; Damstra, Janalt; Schepers, Rutger H; Gerrits, Pieter; Ren, Yijin

    2012-01-01

    AIMS: To assess the accuracy of surface models derived from 3D cone beam computed tomography (CBCT) with two different segmentation protocols. MATERIALS AND METHODS: Seven fresh-frozen cadaver heads were used. There was no conflict of interests in this study. CBCT scans were made of the heads and 3D

  19. The influence of the segmentation process on 3D measurements from cone beam computed tomography-derived surface models

    NARCIS (Netherlands)

    Engelbrecht, Willem P.; Fourie, Zacharias; Damstra, Janalt; Gerrits, Peter O.; Ren, Yijin

    2013-01-01

    To compare the accuracy of linear and angular measurements between cephalometric and anatomic landmarks on surface models derived from 3D cone beam computed tomography (CBCT) with two different segmentation protocols was the aim of this study. CBCT scans were made of cadaver heads and 3D surface mod

  20. The Effects of 3D Computer Modelling on Conceptual Change about Seasons and Phases of the Moon

    Science.gov (United States)

    Kucukozer, Huseyin

    2008-01-01

    In this study, prospective science teachers' misconceptions about the seasons and the phases of the Moon were determined, and then the effects of 3D computer modelling on their conceptual changes were investigated. The topics were covered in two classes with a total of 76 students using a predict-observe-explain strategy supported by 3D computer…

  1. 3D thermal-hydraulic analysis of two irregular field joints for the ITER vacuum vessel

    Energy Technology Data Exchange (ETDEWEB)

    Savoldi, Laura, E-mail: laura.savoldi@polito.it [Dipartimento Energia, Politecnico di Torino, I-10129 Torino (Italy); Bonifetto, Roberto [Dipartimento Energia, Politecnico di Torino, I-10129 Torino (Italy); Izquierdo, Jesus [Fusion for Energy, ES-08019 Barcelona (Spain); Le Barbier, Robin; Utin, Yuri [ITER Organization, Route de Vinon sur Verdon, CS 90 046, 13067 Saint Paul Lez Durance Cedex (France); Zanino, Roberto [Dipartimento Energia, Politecnico di Torino, I-10129 Torino (Italy)

    2015-10-15

    Highlights: • ITER vacuum vessel irregular field joints analyzed with ANSYS-FLUENT. • Steady-state thermal-hydraulic performance evaluated with 3D analysis. • Pressure drop comparable to that of regular field joints. • Acceptable hot spots on the inner shell and ports. • Heat transfer coefficient above the target value of 500 W/m{sup 2} K on the inner shell. - Abstract: In ITER, so-called “Irregular” Field Joints (IFJs) are foreseen at the interface between irregular sectors of the Vacuum Vessel (VV), which is located inside the cryostat and houses the in-vessel components. In the IFJs, a peculiar design of the equatorial port, with respect to that adopted in the Regular Field Joints (RFJs), accommodates the irregularities of the adjacent VV sectors. The IFJs are subject to nuclear heating and actively cooled by sub-cooled pressurized water flowing in a dedicated hydraulic loop, which includes the space left open by the borated In-Wall Shielding (IWS). Here we perform the 3D steady state thermal-hydraulic analysis of two different IFJs using the Computational Fluid Dynamics (CFD) software ANSYS-FLUENT{sup ®}. The water flow field, the pressure drop and the temperature maps are computed. The thermal performance of the IFJs in nominal operation is compared to that of an RFJ and it is shown that also in this case enough cooling capability is available to avoid hot spots above the design limits, while the pressure drop remains acceptably low.

  2. 3-D acquisition geometry analysis: Incorporating information from multiples

    NARCIS (Netherlands)

    Kumar, A.; Blacquiere, G.; Verschuur, D.J.

    2014-01-01

    Recent advances in survey design have led to conventional common-midpoint-based analysis being replaced by the subsurface-based seismic acquisition analysis and design, with the emphasis on advance techniques of illumination analysis. Amongst them are wave-equation-based seismic illumination analyse

  3. DiAna, an ImageJ tool for object-based 3D co-localization and distance analysis

    OpenAIRE

    2016-01-01

    International audience; We present a new plugin for ImageJ called DiAna, for Distance Analysis, which comes with a user-friendly interface. DiAna proposes robust and accurate 3D segmentation for object extraction. The plugin performs automated object-based co-localization and distance analysis. DiAna offers an in-depth analysis of co-localization between objects and retrieves 3D measurements including co-localizing volumes and surfaces of contact. It also computes the distribution of distance...

  4. 3D CFD Analysis of a Vertical Axis Wind Turbine

    Directory of Open Access Journals (Sweden)

    Andrea Alaimo

    2015-04-01

    Full Text Available To analyze the complex and unsteady aerodynamic flow associated with wind turbine functioning, computational fluid dynamics (CFD is an attractive and powerful method. In this work, the influence of different numerical aspects on the accuracy of simulating a rotating wind turbine is studied. In particular, the effects of mesh size and structure, time step and rotational velocity have been taken into account for simulation of different wind turbine geometries. The applicative goal of this study is the comparison of the performance between a straight blade vertical axis wind turbine and a helical blade one. Analyses are carried out through the use of computational fluid dynamic ANSYS® Fluent® software, solving the Reynolds averaged Navier–Stokes (RANS equations. At first, two-dimensional simulations are used in a preliminary setup of the numerical procedure and to compute approximated performance parameters, namely the torque, power, lift and drag coefficients. Then, three-dimensional simulations are carried out with the aim of an accurate determination of the differences in the complex aerodynamic flow associated with the straight and the helical blade turbines. Static and dynamic results are then reported for different values of rotational speed.

  5. Performance analysis of high quality parallel preconditioners applied to 3D finite element structural analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kolotilina, L.; Nikishin, A.; Yeremin, A. [and others

    1994-12-31

    The solution of large systems of linear equations is a crucial bottleneck when performing 3D finite element analysis of structures. Also, in many cases the reliability and robustness of iterative solution strategies, and their efficiency when exploiting hardware resources, fully determine the scope of industrial applications which can be solved on a particular computer platform. This is especially true for modern vector/parallel supercomputers with large vector length and for modern massively parallel supercomputers. Preconditioned iterative methods have been successfully applied to industrial class finite element analysis of structures. The construction and application of high quality preconditioners constitutes a high percentage of the total solution time. Parallel implementation of high quality preconditioners on such architectures is a formidable challenge. Two common types of existing preconditioners are the implicit preconditioners and the explicit preconditioners. The implicit preconditioners (e.g. incomplete factorizations of several types) are generally high quality but require solution of lower and upper triangular systems of equations per iteration which are difficult to parallelize without deteriorating the convergence rate. The explicit type of preconditionings (e.g. polynomial preconditioners or Jacobi-like preconditioners) require sparse matrix-vector multiplications and can be parallelized but their preconditioning qualities are less than desirable. The authors present results of numerical experiments with Factorized Sparse Approximate Inverses (FSAI) for symmetric positive definite linear systems. These are high quality preconditioners that possess a large resource of parallelism by construction without increasing the serial complexity.

  6. Fatigue of hybrid glass/carbon composites: 3D computational studies

    DEFF Research Database (Denmark)

    Dai, Gaoming; Mishnaevsky, Leon

    2014-01-01

    3D computational simulations of fatigue of hybrid carbon/glass fiber reinforced composites is carried out using X-FEM and multifiber unit cell models. A new software code for the automatic generation of unit cell multifiber models of composites with randomly misaligned fibers of various properties...... and geometrical parameters is developed. With the use of this program code and the X-FEM method, systematic investigations of the effect of microstructure of hybrid composites (fraction of carbon versus glass fibers, misalignment, and interface strength) and the loading conditions (tensile versus compression...... cyclic loading effects) on fatigue behavior of the materials are carried out. It was demonstrated that the higher fraction of carbon fibers in hybrid composites is beneficial for the fatigue lifetime of the composites under tension-tension cyclic loading, but might have negative effect on the lifetime...

  7. ROLE OF COMPUTED TOMOGRAPHY AND 3D RECONSTRUCTIONS IN PELVIC RIM AND ACETABULAR FRACTURES

    Directory of Open Access Journals (Sweden)

    Somasekhar

    2015-03-01

    Full Text Available To determine the role of computed tomography and 3D Reconstructions in classification of pelvic rim and acetabular fractures and assessing possible changes in fracture classification . We collected retrospective information in a period of 18 months in our institution , of patients with pelvic injuries considering --- demographic data , radiological examination performed and the moment when it was performed , fracture classification and management . In 12 cases ( 54% there were isolated pelvic rim fr actures and 7 cases of isolated acetabular fractures ( 32% and 3 cases ( 14% involving both . After the CT scan was obtained , the initial classification was changed in five cases ( 22 . 7% . Tridimensional CT based modeling is very helpful in the classificati on of pelvic fractures and is a complement of the plain X - ray .

  8. Roughness receptivity studies in a 3-D boundary layer - Flight tests and computations

    Science.gov (United States)

    Carpenter, Andrew L.; Saric, William S.; Reed, Helen L.

    The receptivity of 3-D boundary layers to micron-sized, spanwise-periodic Discrete Roughness Elements (DREs) was studied. The DREs were applied to the leading edge of a 30-degree swept-wing at the wavelength of the most unstable disturbance. In this case, calibrated, multi-element hotfilm sensors were used to measure disturbance wall shear stress. The roughness height was varied from 0 to 50 microns. Thus, the disturbance-shear-stress amplitude variations were determined as a function of modulated DRE heights. The computational work was conducted parallel to the flight experiments. The complete viscous flowfield over the O-2 aircraft with the SWIFT model mounted on the port wing store pylon was successfully modeled and validated with the flight data. This highly accurate basic-state solution was incorporated into linear stability calculations and the wave growth associated with the crossflow instability was calculated.

  9. A New Energy-Based Method for 3-D Finite-Element Nonlinear Flux Linkage computation of Electrical Machines

    DEFF Research Database (Denmark)

    Lu, Kaiyuan; Rasmussen, Peter Omand; Ritchie, Ewen

    2011-01-01

    This paper presents a new method for computation of the nonlinear flux linkage in 3-D finite-element models (FEMs) of electrical machines. Accurate computation of the nonlinear flux linkage in 3-D FEM is not an easy task. Compared to the existing energy-perturbation method, the new technique......-perturbation method. The new method proposed is validated using experimental results on two different permanent magnet machines....

  10. Computation of a high-resolution MRI 3D stereotaxic atlas of the sheep brain.

    Science.gov (United States)

    Ella, Arsène; Delgadillo, José A; Chemineau, Philippe; Keller, Matthieu

    2017-02-15

    The sheep model was first used in the fields of animal reproduction and veterinary sciences and then was utilized in fundamental and preclinical studies. For more than a decade, magnetic resonance (MR) studies performed on this model have been increasingly reported, especially in the field of neuroscience. To contribute to MR translational neuroscience research, a brain template and an atlas are necessary. We have recently generated the first complete T1-weighted (T1W) and T2W MR population average images (or templates) of in vivo sheep brains. In this study, we 1) defined a 3D stereotaxic coordinate system for previously established in vivo population average templates; 2) used deformation fields obtained during optimized nonlinear registrations to compute nonlinear tissues or prior probability maps (nlTPMs) of cerebrospinal fluid (CSF), gray matter (GM), and white matter (WM) tissues; 3) delineated 25 external and 28 internal sheep brain structures by segmenting both templates and nlTPMs; and 4) annotated and labeled these structures using an existing histological atlas. We built a quality high-resolution 3D atlas of average in vivo sheep brains linked to a reference stereotaxic space. The atlas and nlTPMs, associated with previously computed T1W and T2W in vivo sheep brain templates and nlTPMs, provide a complete set of imaging space that are able to be imported into other imaging software programs and could be used as standardized tools for neuroimaging studies or other neuroscience methods, such as image registration, image segmentation, identification of brain structures, implementation of recording devices, or neuronavigation. J. Comp. Neurol. 525:676-692, 2017. © 2016 Wiley Periodicals, Inc.

  11. 3D Kinematics and Hydrodynamic Analysis of Freely Swimming Cetacean

    Science.gov (United States)

    Ren, Yan; Sheinberg, Dustin; Liu, Geng; Dong, Haibo; Fish, Frank; Javed, Joveria

    2015-11-01

    It's widely thought that flexibility and the ability to control flexibility are crucial elements in determining the performance of animal swimming. However, there is a lack of quantification of both span-wise and chord-wise deformation of Cetacean's flukes and associated hydrodynamic performance during actively swimming. To fill this gap, we examined the motion and flexure of both dolphin fluke and orca fluke in steady swimming using a combined experimental and computational approach. It is found that the fluke surface morphing can effectively modulate the flow structures and influence the propulsive performance. Findings from this work are fundamental for understanding key kinematic features of effective Cetacean propulsors, and for quantifying the hydrodynamic force production that naturally occurs during different types of swimming. This work is supported by ONR MURI N00014-14-1-0533 and NSF CBET-1313217.

  12. Real-time computer-generated integral imaging and 3D image calibration for augmented reality surgical navigation.

    Science.gov (United States)

    Wang, Junchen; Suenaga, Hideyuki; Liao, Hongen; Hoshi, Kazuto; Yang, Liangjing; Kobayashi, Etsuko; Sakuma, Ichiro

    2015-03-01

    Autostereoscopic 3D image overlay for augmented reality (AR) based surgical navigation has been studied and reported many times. For the purpose of surgical overlay, the 3D image is expected to have the same geometric shape as the original organ, and can be transformed to a specified location for image overlay. However, how to generate a 3D image with high geometric fidelity and quantitative evaluation of 3D image's geometric accuracy have not been addressed. This paper proposes a graphics processing unit (GPU) based computer-generated integral imaging pipeline for real-time autostereoscopic 3D display, and an automatic closed-loop 3D image calibration paradigm for displaying undistorted 3D images. Based on the proposed methods, a novel AR device for 3D image surgical overlay is presented, which mainly consists of a 3D display, an AR window, a stereo camera for 3D measurement, and a workstation for information processing. The evaluation on the 3D image rendering performance with 2560×1600 elemental image resolution shows the rendering speeds of 50-60 frames per second (fps) for surface models, and 5-8 fps for large medical volumes. The evaluation of the undistorted 3D image after the calibration yields sub-millimeter geometric accuracy. A phantom experiment simulating oral and maxillofacial surgery was also performed to evaluate the proposed AR overlay device in terms of the image registration accuracy, 3D image overlay accuracy, and the visual effects of the overlay. The experimental results show satisfactory image registration and image overlay accuracy, and confirm the system usability.

  13. Inverse Multifractal Analysis of Different Frame Types of Multiview 3D Video

    Directory of Open Access Journals (Sweden)

    A. Zeković

    2014-11-01

    Full Text Available In this paper, the results of multifractal characterization of multiview 3D video are presented. Analyses are performed for different views of multiview video and for different frame types of video. Multifractal analysis is performed by the histogram method. Due to the advantages of the selected method for determining the spectrum, the inverse multifractal analysis of multiview 3D video was also possible. A discussion of the results obtained by the inverse multifractal analysis of multiview 3D video is presented, taking into account the frame type and whether the original frames belong to the left or right view of multiview 3D video. In the analysis, publicly available multiview 3D video traces were used.

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

    Directory of Open Access Journals (Sweden)

    Benjamin Leporq

    2013-01-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  16. Depth migration and de-migration for 3-D migration velocity analysis; Migration profondeur et demigration pour l'analyse de vitesse de migration 3D

    Energy Technology Data Exchange (ETDEWEB)

    Assouline, F.

    2001-07-01

    for the application of migration velocity analysis. We are interested in particular in an important problem: the influence of irregularities in seismic acquisition on the quality of the depth migrated images. Indeed, 3-D seismic acquisitions show irregularities which are characterized by offset variations as well as a non uniform spatial sampling of the data. To overcome the first kind of irregularities, we propose to introduce the concept of migration by offset class in which are migrated all seismic traces that belong to a given offset class, and we show that such a migration relies on a sound theoretical basis whenever the offset varies smoothly with the midpoint coordinate. These theoretical considerations are validated experimentally: offset classes constructed so that the offset varies slowly with the midpoint coordinate allow to obtain the required imaging quality for migration velocity analysis. The influence, on the quality of the migrated images, of a non uniform spatial sampling of the data is, as for it, much more important than the one linked to offset variations: the computation of the superposition of migrated images associated with each midpoint requires the use of a genuine numerical integration formula. We study quadrature formulas based on polynomial interpolation procedures of the function to be integrated. We recommend to use the Hermite interpolation based numerical integration formula if we are primarily interested in amplitude variations in the case of gently dipping layers, and the Lagrange interpolation based numerical integration formula for the imaging of structures involving some complexity. Moreover, the implementation of these schemes of interpolation consists of a preprocessing of the data and does not really increase the CPU time required for running the migration itself. Of course, these approaches require that the distribution of midpoints is dense enough so as to take correctly into account the variations of the function to be

  17. 3D Quantification of Mandibular Asymmetry through Cone Beam Computed Tomography

    Science.gov (United States)

    Cevidanes, Lucia H.S.; Alhadidi, Abeer; Paniagua, Beatriz; Styner, Martin; Ludlow, John; Mol, Andre; Turvey, Timothy; Proffit, William R.; Rossouw, Paul Emile

    2011-01-01

    Objective To determine if 3D shape analysis precisely diagnoses right and left differences in asymmetry patients Study Design Cone-beam CT data was acquired pretreatment from 20 patients with mandibular asymmetry. 3D shape analysis was used to localize and quantify the extent of virtually simulated asymmetry. Two approaches were used: (1) mirroring on the midsagittal plane determined from landmarks and (2) mirroring on an arbitrary plane, then registering on the cranial base of the original image. The validation presented in this study used simulated data and has been applied to three clinical cases. Results For mirroring on the midsagittal plane there was a >99% probability that the difference between measured and simulated asymmetry was less than 0.5 mm. For mirroring with cranial base registration, there was a >84% probability of differences less than 0.5 mm. Conclusions Mandibular asymmetry can be precisely quantified with both mirroring methods. Cranial base registration has the potential to be used for patients with trauma situations or when key landmarks are unreliable or absent. PMID:21497527

  18. A 3D computer-aided design system applied to diagnosis and treatment planning in orthodontics and orthognathic surgery.

    Science.gov (United States)

    Motohashi, N; Kuroda, T

    1999-06-01

    The purpose of this article is to describe a newly developed 3D computer-aided design (CAD) system for the diagnostic set-up of casts in orthodontic diagnosis and treatment planning, and its preliminary clinical applications. The system comprises a measuring unit which obtains 3D information from the dental model using laser scanning, and a personal computer to generate the 3D graphics. When measuring the 3D shape of the model, to minimize blind sectors, the model is scanned from two different directions with the slit-ray laser beam by rotating the mounting angle of the model on the measuring device. For computed simulation of tooth movement, the representative planes, defined by the anatomical reference points, are formed for each individual tooth and are arranged along a guideline descriptive of the individual arch form. Subsequently, the 3D shape is imparted to each of the teeth arranged on the representative plane to form an arrangement of the 3D profile. When necessary, orthognathic surgery can be simulated by moving the mandibular dental arch three-dimensionally to establish the optimum occlusal relationship. Compared with hand-made set-up models, the computed diagnostic cast has advantages such as high-speed processing and quantitative evaluation on the amount of 3D movement of the individual tooth relative to the craniofacial plane. Trial clinical applications demonstrated that the use of this system facilitated the otherwise complicated and time-consuming mock surgery for treatment planning in orthognathic surgery.

  19. Limit Analysis of 3D Reinforced Concrete Beam Elements

    DEFF Research Database (Denmark)

    Larsen, Kasper P.; Nielsen, Leif Otto; Poulsen, Peter Noe

    2012-01-01

    A new finite-element framework for lower-bound limit analysis of reinforced concrete beams, subjected to loading in three dimensions, is presented. The method circumvents the need for a direct formulation of a complex section-force-based yield criterion by creating a discrete representation of th...

  20. Analysis of information for cerebrovascular disorders obtained by 3D MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Kohki [Tokyo Univ. (Japan). Inst. of Medical Science; Yoshioka, Naoki; Watanabe, Fumio; Shiono, Takahiro; Sugishita, Morihiro; Umino, Kazunori

    1995-12-01

    Recently, it becomes easy to analyze information obtained by 3D MR imaging due to remarkable progress of fast MR imaging technique and analysis tool. Six patients suffered from aphasia (4 cerebral infarctions and 2 bleedings) were performed 3D MR imaging (3D FLASH-TR/TE/flip angle; 20-50 msec/6-10 msec/20-30 degrees) and their volume information were analyzed by multiple projection reconstruction (MPR), surface rendering 3D reconstruction, and volume rendering 3D reconstruction using Volume Design PRO (Medical Design Co., Ltd.). Four of them were diagnosed as Broca`s aphasia clinically and their lesions could be detected around the cortices of the left inferior frontal gyrus. Another 2 patients were diagnosed as Wernicke`s aphasia and the lesions could be detected around the cortices of the left supramarginal gyrus. This technique for 3D volume analyses would provide quite exact locational information about cerebral cortical lesions. (author).

  1. A Computational Method for 3D Anisotropic Travel-time Tomography of Rocks in the Laboratory

    Science.gov (United States)

    Ghofranitabari, Mehdi; Young, R. Paul

    2013-04-01

    True triaxial loading in the laboratory applies three principal stresses on a cubic rock specimen. Elliptical anisotropy and distributed heterogeneities are introduced in the rock due to closure and opening of the pre-existing cracks and creation and growth of the new aligned cracks. The rock sample is tested in a Geophysical Imaging Cell that is armed with an Acoustic Emission monitoring system which can perform transducer to transducer velocity surveys to image velocity structure of the sample during the experiment. Ultrasonic travel-time tomography as a non-destructive method outfits a map of wave propagation velocity in the sample in order to detect the uniformly distributed or localised heterogeneities and provide the spatial variation and temporal evolution of induced damages in rocks at various stages of loading. The rock sample is partitioned into cubic grid cells as model space. Ray-based tomography method measuring body wave travel time along ray paths between pairs of emitting and receiving transducers is used to calculate isotropic ray-path segment matrix elements (Gij) which contain segment lengths of the ith ray in the jth cell in three dimensions. Synthetic P wave travel times are computed between pairs of transducers in a hypothetical isotropic heterogeneous cubic sample as data space along with an error due to precision of measurement. 3D strain of the squeezed rock and the consequent geometrical deformation is also included in computations for further accuracy. Singular Value Decomposition method is used for the inversion from data space to model space. In the next step, the anisotropic ray-path segment matrix and the corresponded data space are computed for hypothetical anisotropic heterogeneous samples based on the elliptical anisotropic model of velocity which is obtained from the real laboratory experimental data. The method is examined for several different synthetic heterogeneous models. An "Inaccuracy factor" is utilized to inquire the

  2. A Fast Full Tensor Gravity computation algorithm for High Resolution 3D Geologic Interpretations

    Science.gov (United States)

    Jayaram, V.; Crain, K.; Keller, G. R.

    2011-12-01

    We present an algorithm to rapidly calculate the vertical gravity and full tensor gravity (FTG) values due to a 3-D geologic model. This algorithm can be implemented on single, multi-core CPU and graphical processing units (GPU) architectures. Our technique is based on the line element approximation with a constant density within each grid cell. This type of parameterization is well suited for high-resolution elevation datasets with grid size typically in the range of 1m to 30m. The large high-resolution data grids in our studies employ a pre-filtered mipmap pyramid type representation for the grid data known as the Geometry clipmap. The clipmap was first introduced by Microsoft Research in 2004 to do fly-through terrain visualization. This method caches nested rectangular extents of down-sampled data layers in the pyramid to create view-dependent calculation scheme. Together with the simple grid structure, this allows the gravity to be computed conveniently on-the-fly, or stored in a highly compressed format. Neither of these capabilities has previously been available. Our approach can perform rapid calculations on large topographies including crustal-scale models derived from complex geologic interpretations. For example, we used a 1KM Sphere model consisting of 105000 cells at 10m resolution with 100000 gravity stations. The line element approach took less than 90 seconds to compute the FTG and vertical gravity on an Intel Core i7 CPU at 3.07 GHz utilizing just its single core. Also, unlike traditional gravity computational algorithms, the line-element approach can calculate gravity effects at locations interior or exterior to the model. The only condition that must be met is the observation point cannot be located directly above the line element. Therefore, we perform a location test and then apply appropriate formulation to those data points. We will present and compare the computational performance of the traditional prism method versus the line element

  3. CAD, 3D modeling, engineering analysis, and prototype experimentation industrial and research applications

    CERN Document Server

    Zheng Li, Jeremy

    2015-01-01

    This succinct book focuses on computer aided design (CAD), 3-D modeling, and engineering analysis and the ways they can be applied effectively in research and industrial sectors including aerospace, defense, automotive, and consumer products. These efficient tools, deployed for R&D in the laboratory and the field, perform efficiently three-dimensional modeling of finished products, render complex geometrical product designs, facilitate structural analysis and optimal product design, produce graphic and engineering drawings, and generate production documentation. Written with an eye toward green energy installations and novel manufacturing facilities, this concise volume enables scientific researchers and engineering professionals to learn design techniques, control existing and complex issues, proficiently use CAD tools, visualize technical fundamentals, and gain analytic and technical skills. This book also: ·       Equips practitioners and researchers to handle powerful tools for engineering desi...

  4. On the Parallel Design and Analysis for 3-D ADI Telegraph Problem with MPI

    Directory of Open Access Journals (Sweden)

    Simon Uzezi Ewedafe

    2014-05-01

    Full Text Available In this paper we describe the 3-D Telegraph Equation (3-DTEL with the use of Alternating Direction Implicit (ADI method on Geranium Cadcam Cluster (GCC with Message Passing Interface (MPI parallel software. The algorithm is presented by the use of Single Program Multiple Data (SPMD technique. The implementation is discussed by means of Parallel Design and Analysis with the use of Domain Decomposition (DD strategy. The 3-DTEL with ADI scheme is implemented on the GCC cluster, with an objective to evaluate the overhead it introduces, with ability to exploit the inherent parallelism of the computation. Results of the parallel experiments are presented. The Speedup and Efficiency from the experiments on different block sizes agree with the theoretical analysis.

  5. Stereo Scene Flow for 3D Motion Analysis

    CERN Document Server

    Wedel, Andreas

    2011-01-01

    This book presents methods for estimating optical flow and scene flow motion with high accuracy, focusing on the practical application of these methods in camera-based driver assistance systems. Clearly and logically structured, the book builds from basic themes to more advanced concepts, culminating in the development of a novel, accurate and robust optic flow method. Features: reviews the major advances in motion estimation and motion analysis, and the latest progress of dense optical flow algorithms; investigates the use of residual images for optical flow; examines methods for deriving mot

  6. High Resolution Krylov Space 3-D Wavenumber-Frequency Analysis

    Science.gov (United States)

    2007-04-01

    wavenumber-frequency distri- bution of signal modes. That is, PPER (k, f, t) = eH(k) R̂[f, t] e(k). (3) Different from eq.(2), here R̂[f, t] is a time... PPER (k, f, t) frequency f w av en um be r k Capon wavenumber frequency analysis 0.4 0.5 0.6 0.7 0.8 0.9 1 0.5 0.4 0.3 0.2 0.1 0 0.1 0.2 0.3 0.4 0.5 30

  7. Evaluation of stereoscopic 3D displays for image analysis tasks

    Science.gov (United States)

    Peinsipp-Byma, E.; Rehfeld, N.; Eck, R.

    2009-02-01

    In many application domains the analysis of aerial or satellite images plays an important role. The use of stereoscopic display technologies can enhance the image analyst's ability to detect or to identify certain objects of interest, which results in a higher performance. Changing image acquisition from analog to digital techniques entailed the change of stereoscopic visualisation techniques. Recently different kinds of digital stereoscopic display techniques with affordable prices have appeared on the market. At Fraunhofer IITB usability tests were carried out to find out (1) with which kind of these commercially available stereoscopic display techniques image analysts achieve the best performance and (2) which of these techniques achieve a high acceptance. First, image analysts were interviewed to define typical image analysis tasks which were expected to be solved with a higher performance using stereoscopic display techniques. Next, observer experiments were carried out whereby image analysts had to solve defined tasks with different visualization techniques. Based on the experimental results (performance parameters and qualitative subjective evaluations of the used display techniques) two of the examined stereoscopic display technologies were found to be very good and appropriate.

  8. Solar Burst Analysis with 3D Loop Models

    CERN Document Server

    Costa, Joaquim E R; Pinto, Tereza S N; Melnikov, Victor F

    2013-01-01

    A sample of Nobeyama flares was selected and analyzed using loop model for important flare parameters. The model for the flaring region consists of a three dimensional dipolar magnetic field, and spatial distributions of non-thermal electrons. We constructed a database by calculating the flare microwave emission for a wide range of these parameters. Out of this database with more than 5,000 cases we extracted general flare properties by comparing the observed and calculated microwave spectra. The analysis of NoRP data was mostly based in the center-to-limb variation of the flare properties with looptop and footpoint electron distributions and for NoRH maps on the resultant distribution of emission. One important aspect of this work is the comparison of the analysis of a flare using an inhomogeneous source model and a simplistic homogeneous source model. Our results show clearly that the homogeneous source hypothesis is not appropriate to describe the possible flare geometry and its use can easily produce misl...

  9. Sub aquatic 3D visualization and temporal analysis utilizing ArcGIS online and 3D applications

    Science.gov (United States)

    We used 3D Visualization tools to illustrate some complex water quality data we’ve been collecting in the Great Lakes. These data include continuous tow data collected from our research vessel the Lake Explorer II, and continuous water quality data collected from an autono...

  10. 3D Animation Essentials

    CERN Document Server

    Beane, Andy

    2012-01-01

    The essential fundamentals of 3D animation for aspiring 3D artists 3D is everywhere--video games, movie and television special effects, mobile devices, etc. Many aspiring artists and animators have grown up with 3D and computers, and naturally gravitate to this field as their area of interest. Bringing a blend of studio and classroom experience to offer you thorough coverage of the 3D animation industry, this must-have book shows you what it takes to create compelling and realistic 3D imagery. Serves as the first step to understanding the language of 3D and computer graphics (CG)Covers 3D anim

  11. Segmentation, Reconstruction, and Analysis of Blood Thrombus Formation in 3D 2-Photon Microscopy Images

    Directory of Open Access Journals (Sweden)

    Xu Zhiliang

    2010-01-01

    Full Text Available We study the problem of segmenting, reconstructing, and analyzing the structure growth of thrombi (clots in blood vessels in vivo based on 2-photon microscopic image data. First, we develop an algorithm for segmenting clots in 3D microscopic images based on density-based clustering and methods for dealing with imaging artifacts. Next, we apply the union-of-balls (or alpha-shape algorithm to reconstruct the boundary of clots in 3D. Finally, we perform experimental studies and analysis on the reconstructed clots and obtain quantitative data of thrombus growth and structures. We conduct experiments on laser-induced injuries in vessels of two types of mice (the wild type and the type with low levels of coagulation factor VII and analyze and compare the developing clot structures based on their reconstructed clots from image data. The results we obtain are of biomedical significance. Our quantitative analysis of the clot composition leads to better understanding of the thrombus development, and is valuable to the modeling and verification of computational simulation of thrombogenesis.

  12. 3D Reacting Flow Analysis of LANTR Nozzles

    Science.gov (United States)

    Stewart, Mark E. M.; Krivanek, Thomas M.; Hemminger, Joseph A.; Bulman, M. J.

    2006-01-01

    This paper presents performance predictions for LANTR nozzles and the system implications for their use in a manned Mars mission. The LANTR concept is rocket thrust augmentation by injecting Oxygen into the nozzle to combust the Hydrogen exhaust of a Nuclear Thermal Rocket. The performance predictions are based on three-dimensional reacting flow simulations using VULCAN. These simulations explore a range of O2/H2 mixture ratios, injector configurations, and concepts. These performance predictions are used for a trade analysis within a system study for a manned Mars mission. Results indicate that the greatest benefit of LANTR will occur with In-Situ Resource Utilization (ISRU). However, Hydrogen propellant volume reductions may allow greater margins for fitting tanks within the launch vehicle where packaging issues occur.

  13. Time-Domain Analysis for 3-D Moored Systems

    Institute of Scientific and Technical Information of China (English)

    肖越; 王言英

    2004-01-01

    In the paper, a comprehensive numerical study on the moored system is performed in time domain. The moored system, which is composed of the floating body sub-system and the mooring line sub-system, is calculated as a whole system by coupling. A time-domain method is applied to the analysis of the mooring line sub-system, and at the same time, an indirect time-domain method translated from frequency-domain to time-domain is developed to calculate the floating body sub-system. In the end, an FPSO vessel is calculated as a numerical example by the present method. A comparison of the result of the model test and that of the numerical method indicates that the present method is exact and effective.

  14. Detailed 3-D nuclear analysis of ITER blanket modules

    Energy Technology Data Exchange (ETDEWEB)

    Bohm, T.D., E-mail: tdbohm@wisc.edu [University of Wisconsin-Madison, Madison, WI (United States); Sawan, M.E.; Marriott, E.P.; Wilson, P.P.H. [University of Wisconsin-Madison, Madison, WI (United States); Ulrickson, M.; Bullock, J. [Sandia National Laboratories, Albuquerque, NM (United States)

    2014-10-15

    In ITER, the blanket modules (BM) are arranged around the plasma to provide thermal and nuclear shielding for the vacuum vessel (VV), magnets, and other components. As a part of the BM design process, nuclear analysis is required to determine the level of nuclear heating, helium production, and radiation damage in the BM. Additionally, nuclear heating in the VV is also important for assessing the BM design. We used the CAD based DAG-MCNP5 transport code to analyze detailed models inserted into a 40-degree partially homogenized ITER global model. The regions analyzed include BM01, the neutral beam injection (NB) region, and the upper port region. For BM01, the results show that He production meets the limit necessary for re-welding, and the VV heating behind BM01 is acceptable. For the NBI region, the VV nuclear heating behind the NB region exceeds the design limit by a factor of two. For the upper port region, the nuclear heating of the VV exceeds the design limit by up to 20%. The results presented in this work are being used to modify the BM design in the cases where limits are exceeded.

  15. Compatibility analysis of 3D printer resin for biological applications

    KAUST Repository

    Sivashankar, Shilpa

    2016-08-30

    The salient features of microfluidics such as reduced cost, handling small sample and reagent volumes and less time required to fabricate the devices has inspired the present work. The incompatibility of three-dimensional printer resins in their native form and the method to improve their compatibility to many biological processes via surface modification are reported. The compatibility of the material to build microfluidic devices was evaluated in three different ways: (i) determining if the ultraviolet (UV) cured resin inhibits the polymerase chain reaction (PCR), i.e. testing devices for PCR compatibility; (ii) observing agglutination complex formed on the surface of the UV cured resin when anti-C-reactive protein (CRP) antibodies and CRP proteins were allowed to agglutinate; and (iii) by culturing human embryonic kidney cell line cells and testing for its attachment and viability. It is shown that only a few among four in its native form could be used for fabrication of microchannels and that had the least effect on biological molecules that could be used for PCR and protein interactions and cells, whereas the others were used after treating the surface. Importance in building lab-on-chip/micrototal analysis systems and organ-on-chip devices is found.

  16. 3D nuclear track analysis by digital holographic microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, F. [Universidad de Oriente, Santiago de Cuba (Cuba); Palacios Fernandez, D., E-mail: danpalacios@cantv.ne [Universidad Simon Bolivar, P.O. 89000, Caracas 1080 (Venezuela, Bolivarian Republic of); Ricardo, J.; Palacios, G.F. [Universidad de Oriente, Santiago de Cuba (Cuba); Sajo-Bohus, L. [Universidad Simon Bolivar, P.O. 89000, Caracas 1080 (Venezuela, Bolivarian Republic of); Goncalves, E. [Polytechnical School, Sao Paulo University (USP) (Brazil); Valin, J.L. [Instituto Politecnico Superior ' Jose Antonio Echeverria' , Habana (Cuba); Monroy, F.A. [Universidad Nacional de Colombia, Sede Bogota (Colombia)

    2011-01-15

    A new method, based on Digital Holographic Microscopy (DHM), to visualize and to analyze etched tracks in SSNTD has been developed. The proposed method is based on the possibility of the digital holography to perform whole reconstruction of the recorded wave front, so that phase and intensity distribution at a plane located between the object and recording plane and along the reconstructed image of the object can be determined. In a DHM system, the back focal plane of the lens can be reconstructed so that complex amplitudes of the Fraunhofer diffraction of light distribution across the object can be known. With the knowledge and manipulation of the components of this plane is possible to design different methods of image analysis. In this paper, the DHM method was applied to determine the track parameters in CR-39 detectors, showing that most of studies carried out with Confocal Microscopy and Atomic Force Microscopy could be also done, with the sufficient exactitude and precision, but in a simpler and more economic way. The developed microholographic method provides a new alternative procedure that overcomes the current techniques at least in technological simplicity.

  17. Global stability analysis of turbulent 3D wakes

    Science.gov (United States)

    Rigas, Georgios; Sipp, Denis; Juniper, Matthew

    2015-11-01

    At low Reynolds numbers, corresponding to laminar and transitional regimes, hydrodynamic stability theory has aided the understanding of the dynamics of bluff body wake-flows and the application of effective control strategies. However, flows of fundamental importance to many industries, in particular the transport industry, involve high Reynolds numbers and turbulent wakes. Despite their turbulence, such wake flows exhibit organisation which is manifested as coherent structures. Recent work has shown that the turbulent coherent structures retain the shape of the symmetry-breaking laminar instabilities and only those manifest as large-scale structures in the near wake (Rigas et al., JFM vol. 750:R5 2014, JFM vol. 778:R2 2015). Based on the findings of the persistence of the laminar instabilities at high Reynolds numbers, we investigate the global stability characteristics of a turbulent wake generated behind a bluff three-dimensional axisymmetric body. We perform a linear global stability analysis on the experimentally obtained mean flow and we recover the dynamic characteristics and spatial structure of the coherent structures, which are linked to the transitional instabilities. A detailed comparison of the predictions with the experimental measurements will be provided.

  18. Multislice computed tomography angiography in the diagnosis of cardiovascular disease: 3D visualizations

    Institute of Scientific and Technical Information of China (English)

    Zhonghua Sun

    2011-01-01

    Multislice computed tomography (CT) has been widely used in clinical practice for the diagnosis of cardiovascular disease due to its reduced invasiveness and high spatial and temporal resolution.As a reliable alternative to conventional angiography,multislice CT angiography has been recognized as the method of choice for detecting and diagnosing head and neck vascular disease,abdominal aortic aneurysm,aortic dissection,and pulmonary embolism.In patients with suspected coronary artery disease,although invasive coronary angiography still remains as the gold standard technique,multislice CT angiography demonstrates high diagnostic accuracy; in selected patients,it is considered as the first-line technique.The imaging diagnosis of cardiovascular disease is based on a combination of two-dimensional (2D) and three-dimensional (3D) visualization tools to enhance the diagnostic value.This is facilitated by reconstructed visualizations which provide additional information about the extent of the disease,an accurate assessment of the spatial relationship between normal structures and pathological changes,and pre-operative planning and post-procedure follow-up.The aim of the present article is to present an overview of the diagnostic performance of various 2D and 3D CT visualizations in cardiovascular disease,including multiplanar reformation,maximum intensity projection,volume rendering,and virtual intravascular endoscopy.The recognition of the potential value of these visualizations will assist clinicians in efficiently using the muitislice CT imaging modality for the diagnostic management of patients with cardiovascular disease.

  19. Potential hazards of viewing 3-D stereoscopic television, cinema and computer games: a review.

    Science.gov (United States)

    Howarth, Peter A

    2011-03-01

    The visual stimulus provided by a 3-D stereoscopic display differs from that of the real world because the image provided to each eye is produced on a flat surface. The distance from the screen to the eye remains fixed, providing a single focal distance, but the introduction of disparity between the images allows objects to be located geometrically in front of, or behind, the screen. Unlike in the real world, the stimulus to accommodation and the stimulus to convergence do not match. Although this mismatch is used positively in some forms of Orthoptic treatment, a number of authors have suggested that it could negatively lead to the development of asthenopic symptoms. From knowledge of the zone of clear, comfortable, single binocular vision one can predict that, for people with normal binocular vision, adverse symptoms will not be present if the discrepancy is small, but are likely if it is large, and that what constitutes 'large' and 'small' are idiosyncratic to the individual. The accommodation-convergence mismatch is not, however, the only difference between the natural and the artificial stimuli. In the former case, an object located in front of, or behind, a fixated object will not only be perceived as double if the images fall outside Panum's fusional areas, but it will also be defocused and blurred. In the latter case, however, it is usual for the producers of cinema, TV or computer game content to provide an image that is in focus over the whole of the display, and as a consequence diplopic images will be sharply in focus. The size of Panum's fusional area is spatial frequency-dependent, and because of this the high spatial frequencies present in the diplopic 3-D image will provide a different stimulus to the fusion system from that found naturally.

  20. 3-D Computational Modelling of Oblique Continental Collision near South Island, New Zealand

    Science.gov (United States)

    Karatun, L.; Pysklywec, R. N.

    2015-12-01

    The research explores the highly oblique continental convergence at the South Island of New Zealand, considering the fundamental geodynamic mechanisms of sub-crustal lithospheric deformation during the orogenesis. In addition to the high velocity of along-strike plate motion, the oppositely verging subduction zones bounding the collision make the problem inherently three-dimensional. To study such factors during orogenesis, we conduct 3D computational modelling and present the results of a series of new experiments configured for the oblique South Island collision. The geodynamic modelling uses ASPECT - a robust highly-scalable and extendable geodynamic code featuring adaptive mesh refinement and complex rheologies. The model domain is defined by a box with prescribed velocities on the left and right faces with varied ratio of convergent versus strike-slip components, periodic boundary conditions for the front and back faces, free surface on top, and free slip at the bottom. Two different rheology types are used: brittle (pressure-, strain rate-, and material strength-dependent) for crust and visco-plastic (temperature-, pressure- and strain rate-dependent) for mantle. The obtained results provide insight into the behaviour of the lithosphere under the situation of young oblique convergence. We focus on the development of the mantle lithosphere, considering how the morphology of the sub-crustal orogenic root evolves during the convergent/strike-slip plate motions. The numerical experiments explore the dependence of this process on such factors as ratio of convergent versus strike-slip motion at the plate boundary, and rheological parameters of crust and mantle. The behaviour of the crust is also tracked to determine how the deep 3D tectonics may manifest at the surface.

  1. Computationally efficient perturbative forward modeling for 3D multispectral bioluminescence and fluorescence tomography

    Science.gov (United States)

    Dutta, Joyita; Ahn, Sangtae; Li, Changqing; Chaudhari, Abhijit J.; Cherry, Simon R.; Leahy, Richard M.

    2008-03-01

    The forward problem of optical bioluminescence and fluorescence tomography seeks to determine, for a given 3D source distribution, the photon density on the surface of an animal. Photon transport through tissues is commonly modeled by the diffusion equation. The challenge, then, is to accurately and efficiently solve the diffusion equation for a realistic animal geometry and heterogeneous tissue types. Fast analytical solvers are available that can be applied to arbitrary geometries but assume homogeneity of tissue optical properties and hence have limited accuracy. The finite element method (FEM) with volume tessellation allows reasonably accurate modeling of both animal geometry and tissue heterogeneity, but this approach is computationally intensive. The computational challenge is heightened when one is working with multispectral data to improve source localization and conditioning of the inverse problem. Here we present a fast forward model based on the Born approximation that falls in between these two approaches. Our model introduces tissue heterogeneity as perturbations in diffusion and absorption coefficients at rectangular grid points inside a mouse atlas. These reflect as a correction term added to the homogeneous forward model. We have tested our model by performing source localization studies first with a biolumnescence simulation setup and then with an experimental setup using a fluorescent source embedded in an inhomogeneous phantom that mimicks tissue optical properties.

  2. Parallel computing simulation of electrical excitation and conduction in the 3D human heart.

    Science.gov (United States)

    Di Yu; Dongping Du; Hui Yang; Yicheng Tu

    2014-01-01

    A correctly beating heart is important to ensure adequate circulation of blood throughout the body. Normal heart rhythm is produced by the orchestrated conduction of electrical signals throughout the heart. Cardiac electrical activity is the resulted function of a series of complex biochemical-mechanical reactions, which involves transportation and bio-distribution of ionic flows through a variety of biological ion channels. Cardiac arrhythmias are caused by the direct alteration of ion channel activity that results in changes in the AP waveform. In this work, we developed a whole-heart simulation model with the use of massive parallel computing with GPGPU and OpenGL. The simulation algorithm was implemented under several different versions for the purpose of comparisons, including one conventional CPU version and two GPU versions based on Nvidia CUDA platform. OpenGL was utilized for the visualization / interaction platform because it is open source, light weight and universally supported by various operating systems. The experimental results show that the GPU-based simulation outperforms the conventional CPU-based approach and significantly improves the speed of simulation. By adopting modern computer architecture, this present investigation enables real-time simulation and visualization of electrical excitation and conduction in the large and complicated 3D geometry of a real-world human heart.

  3. Detailed 3-D nuclear analysis of ITER outboard blanket modules

    Energy Technology Data Exchange (ETDEWEB)

    Bohm, Tim, E-mail: tdbohm@wisc.edu [Fusion Technology Institute, University of Wisconsin-Madison, Madison, WI (United States); Davis, Andrew; Sawan, Mohamed; Marriott, Edward; Wilson, Paul [Fusion Technology Institute, University of Wisconsin-Madison, Madison, WI (United States); Ulrickson, Michael; Bullock, James [Formerly, Fusion Technology, Sandia National Laboratories, Albuquerque, NM (United States)

    2015-10-15

    Highlights: • Nuclear analysis was performed on detailed CAD models placed in a 40 degree model of ITER. • The regions examined include BM09, the upper ELM coil region (BM11–13), the neutral beam (NB) region (BM13–16), and BM18. • The results show that VV nuclear heating exceeds limits in the NB and upper ELM coil regions. • The results also show that the level of He production in parts of BM18 exceeds limits. • These calculations are being used to modify the design of the ITER blanket modules. - Abstract: In the ITER design, the blanket modules (BM) provide thermal and nuclear shielding for the vacuum vessel (VV), magnets, and other components. We used the CAD based DAG-MCNP5 transport code to analyze detailed models inserted into a 40 degree partially homogenized ITER global model. The regions analyzed include BM09, BM16 near the heating neutral beam injection (HNB) region, BM11–13 near the upper ELM coil region, and BM18. For the BM16 HNB region, the VV nuclear heating behind the NB region exceeds the design limit by up to 80%. For the BM11–13 region, the nuclear heating of the VV exceeds the design limit by up to 45%. For BM18, the results show that He production does not meet the limit necessary for re-welding. The results presented in this work are being used by the ITER Organization Blanket and Tokamak Integration groups to modify the BM design in the cases where limits are exceeded.

  4. Depth migration and de-migration for 3-D migration velocity analysis; Migration profondeur et demigration pour l'analyse de vitesse de migration 3D

    Energy Technology Data Exchange (ETDEWEB)

    Assouline, F.

    2001-07-01

    for the application of migration velocity analysis. We are interested in particular in an important problem: the influence of irregularities in seismic acquisition on the quality of the depth migrated images. Indeed, 3-D seismic acquisitions show irregularities which are characterized by offset variations as well as a non uniform spatial sampling of the data. To overcome the first kind of irregularities, we propose to introduce the concept of migration by offset class in which are migrated all seismic traces that belong to a given offset class, and we show that such a migration relies on a sound theoretical basis whenever the offset varies smoothly with the midpoint coordinate. These theoretical considerations are validated experimentally: offset classes constructed so that the offset varies slowly with the midpoint coordinate allow to obtain the required imaging quality for migration velocity analysis. The influence, on the quality of the migrated images, of a non uniform spatial sampling of the data is, as for it, much more important than the one linked to offset variations: the computation of the superposition of migrated images associated with each midpoint requires the use of a genuine numerical integration formula. We study quadrature formulas based on polynomial interpolation procedures of the function to be integrated. We recommend to use the Hermite interpolation based numerical integration formula if we are primarily interested in amplitude variations in the case of gently dipping layers, and the Lagrange interpolation based numerical integration formula for the imaging of structures involving some complexity. Moreover, the implementation of these schemes of interpolation consists of a preprocessing of the data and does not really increase the CPU time required for running the migration itself. Of course, these approaches require that the distribution of midpoints is dense enough so as to take correctly into account the variations of the function to be

  5. Advanced Visualization and Analysis of Climate Data using DV3D and UV-CDAT

    Science.gov (United States)

    Maxwell, T. P.

    2012-12-01

    This paper describes DV3D, a Vistrails package of high-level modules for the Ultra-scale Visualization Climate Data Analysis Tools (UV-CDAT) interactive visual exploration system that enables exploratory analysis of diverse and rich data sets stored in the Earth System Grid Federation (ESGF). DV3D provides user-friendly workflow interfaces for advanced visualization and analysis of climate data at a level appropriate for scientists. The application builds on VTK, an open-source, object-oriented library, for visualization and analysis. DV3D provides the high-level interfaces, tools, and application integrations required to make the analysis and visualization power of VTK readily accessible to users without exposing burdensome details such as actors, cameras, renderers, and transfer functions. It can run as a desktop application or distributed over a set of nodes for hyperwall or distributed visualization applications. DV3D is structured as a set of modules which can be linked to create workflows in Vistrails. Figure 1 displays a typical DV3D workflow as it would appear in the Vistrails workflow builder interface of UV-CDAT and, on the right, the visualization spreadsheet output of the workflow. Each DV3D module encapsulates a complex VTK pipeline with numerous supporting objects. Each visualization module implements a unique interactive 3D display. The integrated Vistrails visualization spreadsheet offers multiple synchronized visualization displays for desktop or hyperwall. The currently available displays include volume renderers, volume slicers, 3D isosurfaces, 3D hovmoller, and various vector plots. The DV3D GUI offers a rich selection of interactive query, browse, navigate, and configure options for all displays. All configuration operations are saved as Vistrails provenance. DV3D's seamless integration with UV-CDAT's climate data management system (CDMS) and other climate data analysis tools provides a wide range of climate data analysis operations, e

  6. Computational Finite Element Software Assisted Development of a 3D Inductively Coupled Power Transfer System

    Directory of Open Access Journals (Sweden)

    Pratik Raval

    2014-02-01

    Full Text Available To date inductively coupled power transfer (ICPT systems have already found many practical applications including battery charging pads. In fact, current charging platforms tend to largely support only one- or two-dimensional planar movement in load. This paper proposes a new concept of extending the aspect ratios of the operating power transfer volume of ICPT systems to support arbitrary three dimensional load movements with respect to the primary coils. This is done by use of modern finite element method analysis software to propose the primary and secondary magnetic structures of such an ICPT system. Firstly, two primary magnetic structures are proposed based on contrasting modes of operation and different field directions. This includes a single-phase and multi-phase current model. Next, a secondary magnetic structure is customized to be compatible with both primary structures. The resulting system is shown to produce a 3D power transfer volume for battery cell charging applications.

  7. [Upper airway's 3D analysis of patients with obstructive sleep apnea using tomographic cone beam].

    Science.gov (United States)

    Bruwier, A; Poirrier, A L; Limme, M; Poirrier, R

    2014-12-01

    The progress of medical imaging over the last decades has led to a better understanding of the upper airway structure in sleep-disordered patients. The Obstructive Sleep Apnea Syndrome (OSA) is attributed to a functional narrowing of the upper airway, particularly of the oropharynx, during sleep. This narrowing is multifactorial. We have shown that in 60% cases, the maxilla (nasal pyramid) seems too narrow. A mandible retroposition may also play a dominant role in 30% of the cases. Both scenarios can be combined. Cone Beam Computed Tomography (CBCT) is a new medical imaging technique that permits to visualize the upper airway with less ionizing radiation than the conventional scanner. To date, only five authors have performed an upper airway's 3D analysis of sleep apnea patients with cone beam. A better understanding of the affected segment of the upper airway should help refine treatment options.

  8. Micromechanical analysis of nanocomposites using 3D voxel based material model

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon

    2012-01-01

    A computational study on the effect of nanocomposite structures on the elastic properties is carried out with the use of the 3D voxel based model of materials and the combined Voigt–Reuss method. A hierarchical voxel based model of a material reinforced by an array of exfoliated and intercalated...... nanoclay platelets surrounded by interphase layers is developed. With this model, the elastic properties of the interphase layer are estimated using the inverse analysis. The effects of aspect ratio, intercalation and orientation of nanoparticles on the elastic properties of the nanocomposites are analyzed....... For modeling the damage in nanocomposites with intercalated structures, “four phase” model is suggested, in which the strength of “intrastack interphase” is lower than that of “outer” interphase around the nanoplatelets. Analyzing the effect of nanoreinforcement in the matrix on the failure probability...

  9. 3D Finite Elements Modelling for Design and Performance Analysis of UO Pellets

    Directory of Open Access Journals (Sweden)

    Gustavo L. Demarco

    2011-01-01

    Full Text Available The geometry of a fuel pellet is a compromise among the intention to maximize UO2 content and minimize the temperature gradient taking into account the thermomechanical behaviour, the economy, and the safety of the fuel management during and after irradiation. “Dishings”, “shoulders”, “chamfers”, and/or “a central hole” on a cylinder with an improved l/d relation (length of the pellet/diameter are introduced in order to optimize the shape of the pellet. The MeCom tools coupled with the BaCo code constitutes a complete system for the 3D analysis of the stress strain state of the pellet under irradiation. CANDU and PHWR MOX fuel will be used to illustrate the excellent qualitative agreement between experimental data and calculations by using these computational tools.

  10. Multispectral polarization viewing angle analysis of circular polarized stereoscopic 3D displays

    Science.gov (United States)

    Boher, Pierre; Leroux, Thierry; Bignon, Thibault; Collomb-Patton, Véronique

    2010-02-01

    In this paper we propose a method to characterize polarization based stereoscopic 3D displays using multispectral Fourier optics viewing angle measurements. Full polarization analysis of the light emitted by the display in the full viewing cone is made at 31 wavelengths in the visible range. Vertical modulation of the polarization state is observed and explained by the position of the phase shift filter into the display structure. In addition, strong spectral dependence of the ellipticity and polarization degree is observed. These features come from the strong spectral dependence of the phase shift film and introduce some imperfections (color shifts and reduced contrast). Using the measured transmission properties of the two glasses filters, the resulting luminance across each filter is computed for left and right eye views. Monocular contrast for each eye and binocular contrasts are performed in the observer space, and Qualified Monocular and Binocular Viewing Spaces (QMVS and QBVS) can be deduced in the same way as auto-stereoscopic 3D displays allowing direct comparison of the performances.

  11. 3D printing meets computational astrophysics: deciphering the structure of η Carinae's inner colliding winds

    Science.gov (United States)

    Madura, T. I.; Clementel, N.; Gull, T. R.; Kruip, C. J. H.; Paardekooper, J.-P.

    2015-06-01

    We present the first 3D prints of output from a supercomputer simulation of a complex astrophysical system, the colliding stellar winds in the massive (≳120 M⊙), highly eccentric (e ˜ 0.9) binary star system η Carinae. We demonstrate the methodology used to incorporate 3D interactive figures into a PDF (Portable Document Format) journal publication and the benefits of using 3D visualization and 3D printing as tools to analyse data from multidimensional numerical simulations. Using a consumer-grade 3D printer (MakerBot Replicator 2X), we successfully printed 3D smoothed particle hydrodynamics simulations of η Carinae's inner (r ˜ 110 au) wind-wind collision interface at multiple orbital phases. The 3D prints and visualizations reveal important, previously unknown `finger-like' structures at orbital phases shortly after periastron (φ ˜ 1.045) that protrude radially outwards from the spiral wind-wind collision region. We speculate that these fingers are related to instabilities (e.g. thin-shell, Rayleigh-Taylor) that arise at the interface between the radiatively cooled layer of dense post-shock primary-star wind and the fast (3000 km s-1), adiabatic post-shock companion-star wind. The success of our work and easy identification of previously unrecognized physical features highlight the important role 3D printing and interactive graphics can play in the visualization and understanding of complex 3D time-dependent numerical simulations of astrophysical phenomena.

  12. A new approach of building 3D visualization framework for multimodal medical images display and computed assisted diagnosis

    Science.gov (United States)

    Li, Zhenwei; Sun, Jianyong; Zhang, Jianguo

    2012-02-01

    As more and more CT/MR studies are scanning with larger volume of data sets, more and more radiologists and clinician would like using PACS WS to display and manipulate these larger data sets of images with 3D rendering features. In this paper, we proposed a design method and implantation strategy to develop 3D image display component not only with normal 3D display functions but also with multi-modal medical image fusion as well as compute-assisted diagnosis of coronary heart diseases. The 3D component has been integrated into the PACS display workstation of Shanghai Huadong Hospital, and the clinical practice showed that it is easy for radiologists and physicians to use these 3D functions such as multi-modalities' (e.g. CT, MRI, PET, SPECT) visualization, registration and fusion, and the lesion quantitative measurements. The users were satisfying with the rendering speeds and quality of 3D reconstruction. The advantages of the component include low requirements for computer hardware, easy integration, reliable performance and comfortable application experience. With this system, the radiologists and the clinicians can manipulate with 3D images easily, and use the advanced visualization tools to facilitate their work with a PACS display workstation at any time.

  13. A Hierarchical Multiscale Particle Computational Method for Simulation of Nanoscale Flows on 3D Unstructured Grids

    Science.gov (United States)

    2009-08-14

    dimensional Electrostatic Particle-in-Cell Metho - dology on Unstructured Delaunay-Voronoi Grids", Journal of Computational Physics , Vo- lume 228, Issue 10...addresses mathematical and computational issues of par dimensional simulation of flows at the nanoscale. The research addre phenomena in nanoscale flows...sses also the multi-scale physical devices and processes. The DSMC) method are presented, the analysis of statistical es obtained from U3DSMC es

  14. Thoracic cavity definition for 3D PET/CT analysis and visualization.

    Science.gov (United States)

    Cheirsilp, Ronnarit; Bascom, Rebecca; Allen, Thomas W; Higgins, William E

    2015-07-01

    X-ray computed tomography (CT) and positron emission tomography (PET) serve as the standard imaging modalities for lung-cancer management. CT gives anatomical details on diagnostic regions of interest (ROIs), while PET gives highly specific functional information. During the lung-cancer management process, a patient receives a co-registered whole-body PET/CT scan pair and a dedicated high-resolution chest CT scan. With these data, multimodal PET/CT ROI information can be gleaned to facilitate disease management. Effective image segmentation of the thoracic cavity, however, is needed to focus attention on the central chest. We present an automatic method for thoracic cavity segmentation from 3D CT scans. We then demonstrate how the method facilitates 3D ROI localization and visualization in patient multimodal imaging studies. Our segmentation method draws upon digital topological and morphological operations, active-contour analysis, and key organ landmarks. Using a large patient database, the method showed high agreement to ground-truth regions, with a mean coverage=99.2% and leakage=0.52%. Furthermore, it enabled extremely fast computation. For PET/CT lesion analysis, the segmentation method reduced ROI search space by 97.7% for a whole-body scan, or nearly 3 times greater than that achieved by a lung mask. Despite this reduction, we achieved 100% true-positive ROI detection, while also reducing the false-positive (FP) detection rate by >5 times over that achieved with a lung mask. Finally, the method greatly improved PET/CT visualization by eliminating false PET-avid obscurations arising from the heart, bones, and liver. In particular, PET MIP views and fused PET/CT renderings depicted unprecedented clarity of the lesions and neighboring anatomical structures truly relevant to lung-cancer assessment.

  15. Principal component analysis in construction of 3D human knee joint models using a statistical shape model method.

    Science.gov (United States)

    Tsai, Tsung-Yuan; Li, Jing-Sheng; Wang, Shaobai; Li, Pingyue; Kwon, Young-Min; Li, Guoan

    2015-01-01

    The statistical shape model (SSM) method that uses 2D images of the knee joint to predict the three-dimensional (3D) joint surface model has been reported in the literature. In this study, we constructed a SSM database using 152 human computed tomography (CT) knee joint models, including the femur, tibia and patella and analysed the characteristics of each principal component of the SSM. The surface models of two in vivo knees were predicted using the SSM and their 2D bi-plane fluoroscopic images. The predicted models were compared to their CT joint models. The differences between the predicted 3D knee joint surfaces and the CT image-based surfaces were 0.30 ± 0.81 mm, 0.34 ± 0.79 mm and 0.36 ± 0.59 mm for the femur, tibia and patella, respectively (average ± standard deviation). The computational time for each bone of the knee joint was within 30 s using a personal computer. The analysis of this study indicated that the SSM method could be a useful tool to construct 3D surface models of the knee with sub-millimeter accuracy in real time. Thus, it may have a broad application in computer-assisted knee surgeries that require 3D surface models of the knee.

  16. 3D BUILDING MODELS SEGMENTATION BASED ON K-MEANS++ CLUSTER ANALYSIS

    Directory of Open Access Journals (Sweden)

    C. Zhang

    2016-10-01

    Full Text Available 3D mesh model segmentation is drawing increasing attentions from digital geometry processing field in recent years. The original 3D mesh model need to be divided into separate meaningful parts or surface patches based on certain standards to support reconstruction, compressing, texture mapping, model retrieval and etc. Therefore, segmentation is a key problem for 3D mesh model segmentation. In this paper, we propose a method to segment Collada (a type of mesh model 3D building models into meaningful parts using cluster analysis. Common clustering methods segment 3D mesh models by K-means, whose performance heavily depends on randomized initial seed points (i.e., centroid and different randomized centroid can get quite different results. Therefore, we improved the existing method and used K-means++ clustering algorithm to solve this problem. Our experiments show that K-means++ improves both the speed and the accuracy of K-means, and achieve good and meaningful results.

  17. Model and numerical analysis of 3D corrosion layer of reinforced concrete structure

    Institute of Scientific and Technical Information of China (English)

    李永和; 葛修润

    2003-01-01

    Under the assumption that the corrosion at the end of steel bolt or steel bar is shaped like the contour line of ellipsoid, a mathematic model and formulas of calculating the thickness of corrosion layer at arbitrary point are presented in this paper. Then regarding the arbitrary points of 3D corrosion layer as patch element model of fictitious displacement discontinuity, we propose the basic solution of 3D problem of the patch element acting on discontinuous displacement. With three basic assumptions of the corrosion layer, we set up the 3D numerical discreted model, and derive the stress boundary equation for fictitious corrosion layer of 3D numerical analysis. We also make the numerical stimulating calculation of the shotcrete structure at some lane using 3D finite element method. The results show that this method is effective and reasonable.

  18. Computed Tomography 3-D Imaging of the Metal Deformation Flow Path in Friction Stir Welding

    Science.gov (United States)

    Schneider, Judy; Beshears, Ronald; Nunes, Arthur C., Jr.

    2005-01-01

    In friction stir welding (FSW), a rotating threaded pin tool is inserted into a weld seam and literally stirs the edges of the seam together. To determine optimal processing parameters for producing a defect free weld, a better understanding of the resulting metal deformation flow path is required. Marker studies are the principal method of studying the metal deformation flow path around the FSW pin tool. In our study, we have used computed tomography (CT) scans to reveal the flow pattern of a lead wire embedded in a FSW weld seam. At the welding temperature of aluminum, the lead becomes molten and is carried with the macro-flow of the weld metal. By using CT images, a 3-dimensional (3D) image of the lead flow pattern can be reconstructed. CT imaging was found to be a convenient and comprehensive way of collecting and displaying tracer data. It marks an advance over previous more tedious and ambiguous radiographic/metallographic data collection methods.

  19. Real-time 3D computed tomographic reconstruction using commodity graphics hardware

    Science.gov (United States)

    Xu, Fang; Mueller, Klaus

    2007-07-01

    The recent emergence of various types of flat-panel x-ray detectors and C-arm gantries now enables the construction of novel imaging platforms for a wide variety of clinical applications. Many of these applications require interactive 3D image generation, which cannot be satisfied with inexpensive PC-based solutions using the CPU. We present a solution based on commodity graphics hardware (GPUs) to provide these capabilities. While GPUs have been employed for CT reconstruction before, our approach provides significant speedups by exploiting the various built-in hardwired graphics pipeline components for the most expensive CT reconstruction task, backprojection. We show that the timings so achieved are superior to those obtained when using the GPU merely as a multi-processor, without a drop in reconstruction quality. In addition, we also show how the data flow across the graphics pipeline can be optimized, by balancing the load among the pipeline components. The result is a novel streaming CT framework that conceptualizes the reconstruction process as a steady flow of data across a computing pipeline, updating the reconstruction result immediately after the projections have been acquired. Using a single PC equipped with a single high-end commodity graphics board (the Nvidia 8800 GTX), our system is able to process clinically-sized projection data at speeds meeting and exceeding the typical flat-panel detector data production rates, enabling throughput rates of 40-50 projections s-1 for the reconstruction of 5123 volumes.

  20. Real-time 3D computed tomographic reconstruction using commodity graphics hardware

    Energy Technology Data Exchange (ETDEWEB)

    Xu Fang; Mueller, Klaus [Center for Visual Computing, Computer Science Department, Stony Brook University, Stony Brook, NY 11794-4400 (United States)

    2007-07-21

    The recent emergence of various types of flat-panel x-ray detectors and C-arm gantries now enables the construction of novel imaging platforms for a wide variety of clinical applications. Many of these applications require interactive 3D image generation, which cannot be satisfied with inexpensive PC-based solutions using the CPU. We present a solution based on commodity graphics hardware (GPUs) to provide these capabilities. While GPUs have been employed for CT reconstruction before, our approach provides significant speedups by exploiting the various built-in hardwired graphics pipeline components for the most expensive CT reconstruction task, backprojection. We show that the timings so achieved are superior to those obtained when using the GPU merely as a multi-processor, without a drop in reconstruction quality. In addition, we also show how the data flow across the graphics pipeline can be optimized, by balancing the load among the pipeline components. The result is a novel streaming CT framework that conceptualizes the reconstruction process as a steady flow of data across a computing pipeline, updating the reconstruction result immediately after the projections have been acquired. Using a single PC equipped with a single high-end commodity graphics board (the Nvidia 8800 GTX), our system is able to process clinically-sized projection data at speeds meeting and exceeding the typical flat-panel detector data production rates, enabling throughput rates of 40-50 projections s{sup -1} for the reconstruction of 512{sup 3} volumes.

  1. Study of strength properties of ceramic composites with soft filler based on 3D computer simulation

    Science.gov (United States)

    Smolin, Alexey Yu.; Smolin, Igor Yu.; Smolina, Irina Yu.

    2016-11-01

    The movable cellular automaton method which is a computational method of particle mechanics is applied to simulating uniaxial compression of 3D specimens of a ceramic composite. Soft inclusions were considered explicitly by changing the sort (properties) of automata selected randomly from the original fcc packing. The distribution of inclusions in space, their size, and the total fraction were varied. For each value of inclusion fraction, there were generated several representative specimens with individual pore position in space. The resulting magnitudes of the elastic modulus and strength of the specimens were scattered and well described by the Weibull distribution. We showed that to reveal the dependence of the elastic and strength properties of the composite on the inclusion fraction it is much better to consider the mathematical expectation of the corresponding Weibull distribution, rather than the average of the values for the specimens of the same inclusion fraction. It is shown that the relation between the mechanical properties of material and its inclusion fraction depends significantly on the material structure. Namely, percolation transition from isolated inclusions to interconnected clusters of inclusions strongly manifests itself in the dependence of strength on the fraction of inclusions. Thus, the curve of strength versus inclusion fraction fits different equations for a different kind of structure.

  2. Superresolution of 3-D computational integral imaging based on moving least square method.

    Science.gov (United States)

    Kim, Hyein; Lee, Sukho; Ryu, Taekyung; Yoon, Jungho

    2014-11-17

    In this paper, we propose an edge directive moving least square (ED-MLS) based superresolution method for computational integral imaging reconstruction(CIIR). Due to the low resolution of the elemental images and the alignment error of the microlenses, it is not easy to obtain an accurate registration result in integral imaging, which makes it difficult to apply superresolution to the CIIR application. To overcome this problem, we propose the edge directive moving least square (ED-MLS) based superresolution method which utilizes the properties of the moving least square. The proposed ED-MLS based superresolution takes the direction of the edge into account in the moving least square reconstruction to deal with the abrupt brightness changes in the edge regions, and is less sensitive to the registration error. Furthermore, we propose a framework which shows how the data have to be collected for the superresolution problem in the CIIR application. Experimental results verify that the resolution of the elemental images is enhanced, and that a high resolution reconstructed 3-D image can be obtained with the proposed method.

  3. Performance Assessment of Three Rendering Engines in 3D Computer Graphics Software

    Directory of Open Access Journals (Sweden)

    Žan Vidmar

    2015-03-01

    Full Text Available The aim of the research was the determination of testing conditions and visual and numerical evaluation of renderings made with three different rendering engines in Maya software, which is widely used for educational and computer art purposes. In the theoretical part the overview of light phenomena and their simulation in virtual space is presented. This is followed by a detailed presentation of the main rendering methods and the results and limitations of their applications to 3D objects. At the end of the theoretical part the importance of a proper testing scene and especially the role of Cornell box are explained. In the experimental part the terms and conditions as well as hardware and software used for the research are presented. This is followed by a description of the procedures, where we focused on the rendering quality and time, which enabled the comparison of settings of different render engines and determination of conditions for further rendering of testing scenes. The experimental part continued with rendering a variety of simple virtual scenes including Cornell box and virtual object with different materials and colours. Apart from visual evaluation, which was the starting point for comparison of renderings, a procedure for numerical estimation and colour deviations of renderings using the selected regions of interest in the final images is presented.

  4. Detectability of hepatic tumors during 3D post-processed ultrafast cone-beam computed tomography

    Science.gov (United States)

    Paul, Jijo; Vogl, Thomas J.; Chacko, Annamma

    2015-10-01

    To evaluate hepatic tumor detection using ultrafast cone-beam computed tomography (UCBCT) cross-sectional and 3D post-processed image datasets. 657 patients were examined using UCBCT during hepatic transarterial chemoembolization (TACE), and data were collected retrospectively from January 2012 to September 2014. Tumor detectability, diagnostic ability, detection accuracy and sensitivity were examined for different hepatic tumors using UCBCT cross-sectional, perfusion blood volume (PBV) and UCBCT-MRI (magnetic resonance imaging) fused image datasets. Appropriate statistical tests were used to compare collected sample data. Fused image data showed the significantly higher (all P  color display. Fused image data produced 100% tumor sensitivity due to the simultaneous availability of MRI and UCBCT information during tumor diagnosis. Fused image data produced excellent hepatic tumor sensitivity, detectability and diagnostic ability compared to other datasets assessed. Fused image data is extremely reliable and useful compared to UCBCT cross-sectional or PBV image datasets to depict hepatic tumors during TACE. Partial anatomical visualization on cross-sectional images was compensated by fused image data during tumor diagnosis.

  5. Algorithms for Fast Computing of the 3D-DCT Transform

    Directory of Open Access Journals (Sweden)

    S. Hanus

    2003-04-01

    Full Text Available The algorithm for video compression based on the Three-DimensionalDiscrete Cosine Transform (3D-DCT is presented. The original algorithmof the 3D-DCT has high time complexity. We propose several enhancementsto the original algorithm and make the calculation of the DCT algorithmfeasible for future real-time video compression.

  6. 3D structure determination of protein using TEM single particle analysis.

    Science.gov (United States)

    Sato, Chikara; Mio, Kazuhiro; Kawata, Masaaki; Ogura, Toshihiko

    2014-11-01

    Proteins play important roles in cell functions such as enzymes, cell trafficking, neurotransmission, muscle contraction and hormone secretion. However, some proteins are very difficult to be crystallized and their structures are undetermined. Several techniques have been developed to elucidate the structure of macromolecules; X-ray or electron crystallography, nuclear magnetic resonance spectroscopy, and high-resolution electron microscopy. Among them, electron microscopy based single particle reconstruction (SPA) technique is a computer-aided structure determination method. This method reconstructs the 3D structure from projection images of dispersed protein. A large number of two-dimensional particle images are picked up from EM films, aligned and classified to generate 2D averages, and used to reconstruct the 3D structure by assigning the Euler angle of each 2D average. Due to the necessity of elaborate collaboration between the classical biology and the innovative information technology including parallel computing, scientists needed to break unseen barriers to get a start of this analysis. However, recent progresses in electron microscopes, mathematical algorithms, and computational abilities greatly reduced the height of barriers and expanded targets that are considered to be primarily addressable using single particle analysis. Membrane proteins are one of these targets to which the single particle analysis is successfully applied for the understanding of their 3D structures. For this purpose, we have developed various SPA methods [1-5] and applied them to different proteins [6-8].Here, we introduce reconstructed proteins, and discuss the availability of this technique. The intramembrane-cleaving proteases (I-CLiPs) that sever the transmembrane domains of their substrates have been identified in a range of organisms and play a variety of roles in biological conditions. I-CLiPs have been classified into three groups: serine-, aspartyl- and metalloprotease

  7. 3D Printing Meets Computational Astrophysics: Deciphering the Structure of Eta Carinae's Inner Colliding Winds

    CERN Document Server

    Madura, Thomas I; Gull, Theodore R; Kruip, Chael J H; Paardekooper, Jan-Pieter

    2015-01-01

    We present the first 3D prints of output from a supercomputer simulation of a complex astrophysical system, the colliding stellar winds in the massive (>120 M_Sun), highly eccentric (e ~ 0.9) binary star system Eta Carinae. We demonstrate the methodology used to incorporate 3D interactive figures into a PDF journal publication and the benefits of using 3D visualization and 3D printing as tools to analyze data from multidimensional numerical simulations. Using a consumer-grade 3D printer (MakerBot Replicator 2X), we successfully printed 3D smoothed particle hydrodynamics (SPH) simulations of Eta Carinae's inner (r ~ 110 au) wind-wind collision interface at multiple orbital phases. The 3D prints and visualizations reveal important, previously unknown 'finger-like' structures at orbital phases shortly after periastron (phi ~ 1.045) that protrude radially outward from the spiral wind-wind collision region. We speculate that these fingers are related to instabilities (e.g. thin-shell, Rayleigh-Taylor) that arise a...

  8. NUMERICAL SIMULATION OF 3-D TURBULENT FLOWS IN A CUT-OFF VALVE AND ANALYSIS OF FLOW CHARACTERISTICS IN PIPE

    Institute of Scientific and Technical Information of China (English)

    He Zhi-guo; Mao Gen-hai; Yuan Xing-ming

    2003-01-01

    The 3-D turbulent flows in a valve pipe were described by the incompressible Reynolds-averaged Navier-Stokes equations with an RNG k-ε turbulence model. With the finite volume method and a body-fitted coordinate system, the discretised equations were solved by the SIMPLEST algorithm. The numerical result of a cut-off valve with curved inlet shows the flow characteristics and the main cause of energy loss when fluid flows through a valve. And then, the boundaries of valve were modified in order to reduce the energy loss. The computational results of modified valve show that the numerical value of turbulent kinetic energy is lower, and that the modified design of the 3-D valve boundaries is much better. The analysis of the result also shows that RNG k-ε turbulence model can successfully be used to predict the 3-D turbulent separated flows and the secondary flow inside valve pipes.

  9. Laser Welding Analysis for 3D Printed Thermoplastic and Poly-acetate Polymers

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hae Woon; Yun, Sung Chul [Keimyung University, Daegu (Korea, Republic of)

    2015-07-15

    In this study, experimental and computer simulation results are compared and analyzed. Three-dimensional (3D) fabricated matrices from an MJM 3D printer were joined with poly-acetate thermoplastic polymers using a diode laser. A power range of 5-7 W was used to irradiate the boundary of two polymers. The heated polymers flowed into the matrices of the 3D fabricated structure, and reliable mechanical joining was achieved. Computer simulation showed the temperature distribution in the polymers, and flow direction was estimated based on the flux and temperature information. It was found that the more than the minimum energy threshold was required to effectively join the polymers and that two scans at low-speed were more effective than four scans at high speed.

  10. Lagrangian Finite Element Method for 3D Time-Dependent Viscoelastic Flow Computations using Integral Models

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz

    2000-01-01

    The 3D-LIM has as yet been used to simulate the following two three-dimensional problems. First, the method has been used to simulete for viscoelastic end-plate instability that occurs under certain conditions in the transient filament stretching apparatus for pressure sensitive adhesives...... (polymeric melts) and polymeric solutions. Secondly, the 3D-LIM has also been applied to calculate the inflation of a thick sheet of a polymer melt into an elliptic cylinder. These problems all include free surfaces. As the governing equations are solved for the particle positions, the motion of surfaces can...... be followed easily even in 3D viscoelastic flow....

  11. Mobile 3D quality of experience evaluation: a hybrid data collection and analysis approach

    Science.gov (United States)

    Utriainen, Timo; Häyrynen, Jyrki; Jumisko-Pyykkö, Satu; Boev, Atanas; Gotchev, Atanas; Hannuksela, Miska M.

    2011-02-01

    The paper presents a hybrid approach to study the user's experienced quality of 3D visual content on mobile autostereoscopic displays. It combines extensive subjective tests with collection and objective analysis of eye-tracked data. 3D cues which are significant for mobiles are simulated in the generated 3D test content. The methodology for conducting subjective quality evaluation includes hybrid data-collection of quantitative quality preferences, qualitative impressions, and binocular eye-tracking. We present early results of the subjective tests along with eye movement reaction times, areas of interest and heatmaps obtained from raw eye-tracked data after statistical analysis. The study contributes to the question what is important to be visualized on portable auto-stereoscopic displays and how to maintain and visually enhance the quality of 3D content for such displays.

  12. A 3D sparse motion field filtering for quantitative analysis of fascial layers mobility based on 3D ultrasound scans.

    Science.gov (United States)

    Turini, G; Condino, S; Stecco, A; Ferrari, V; Ferrari, M; Gesi, M

    2015-08-01

    In the last few years, there has been an increasing interest in the role of deep fascia mobility in musculoskeletal dynamics and chronic pain mechanisms. In a previous paper we presented an innovative semiautomatic approach to evaluate the 3D motion of the fascia using ultrasound (US) imaging, generating a sparse deformation vector field. This paper presents an improvement of our original method, focusing on the filtering of the sparse vector field and its validation. Moreover, in order to evaluate the performance of the algorithm, a method is proposed to generate synthetic deformation vector fields, including: expansion, rotation, horizontal shear, and oblique shear components. Preliminary tests on the final synthetic deformation vector fields showed promising results. Further experiments are required in order to optimize the tuning of the algorithm.

  13. Computer-Assisted 3D Structure Elucidation of Natural Products using Residual Dipolar Couplings.

    Science.gov (United States)

    Troche-Pesqueira, Eduardo; Anklin, Clemens; Gil, Roberto R; Navarro-Vázquez, Armando

    2017-03-20

    An enhanced computer-assisted procedure for the determination of the relative configuration of natural products, which starts from the molecular formula and uses a combination of conventional 1D and 2D NMR spectra, and residual dipolar couplings (RDCs), is reported. Having already the data acquired (1D/2D NMR and RDCs), the procedure begins with the determination of the molecular constitution using standard computer-assisted structure elucidation (CASE) and is followed by fully automated determination of relative configuration through RDC analysis. In the case of moderately flexible molecules the simplest data-explaining conformational model is selected by the use of the Akaike information criterion.

  14. Automated extraction and analysis of rock discontinuity characteristics from 3D point clouds

    Science.gov (United States)

    Bianchetti, Matteo; Villa, Alberto; Agliardi, Federico; Crosta, Giovanni B.

    2016-04-01

    A reliable characterization of fractured rock masses requires an exhaustive geometrical description of discontinuities, including orientation, spacing, and size. These are required to describe discontinuum rock mass structure, perform Discrete Fracture Network and DEM modelling, or provide input for rock mass classification or equivalent continuum estimate of rock mass properties. Although several advanced methodologies have been developed in the last decades, a complete characterization of discontinuity geometry in practice is still challenging, due to scale-dependent variability of fracture patterns and difficult accessibility to large outcrops. Recent advances in remote survey techniques, such as terrestrial laser scanning and digital photogrammetry, allow a fast and accurate acquisition of dense 3D point clouds, which promoted the development of several semi-automatic approaches to extract discontinuity features. Nevertheless, these often need user supervision on algorithm parameters which can be difficult to assess. To overcome this problem, we developed an original Matlab tool, allowing fast, fully automatic extraction and analysis of discontinuity features with no requirements on point cloud accuracy, density and homogeneity. The tool consists of a set of algorithms which: (i) process raw 3D point clouds, (ii) automatically characterize discontinuity sets, (iii) identify individual discontinuity surfaces, and (iv) analyse their spacing and persistence. The tool operates in either a supervised or unsupervised mode, starting from an automatic preliminary exploration data analysis. The identification and geometrical characterization of discontinuity features is divided in steps. First, coplanar surfaces are identified in the whole point cloud using K-Nearest Neighbor and Principal Component Analysis algorithms optimized on point cloud accuracy and specified typical facet size. Then, discontinuity set orientation is calculated using Kernel Density Estimation and

  15. Intelligent Autonomous Primary 3D Feature Extraction in Vehicle System Dynamics' Analysis: Theory and Application

    Directory of Open Access Journals (Sweden)

    Annamária R. Várkonyi-Kóczy

    2008-01-01

    Full Text Available 3D model reconstruction plays a very important role in computer vision as wellas in different engineering applications. The determination of the 3D model from multipleimages is of key importance. One of the most important difficulties in autonomous 3Dreconstruction is the (automatic selection of the ‘significant’ points which carryinformation about the shape of the 3D bodies i.e. are characteristic from the model point ofview. Another problem to be solved is the point correspondence matching in differentimages.In this paper a 3D reconstruction technique is introduced, which is capable to determinethe 3D model of a scene without any external (human intervention. The method is based onrecent results of image processing, epipolar geometry, and intelligent and soft techniques.Possible applications of the presented algorithm in vehicle system dynamics are alsopresented. The results can be applied advantageously at other engineering fields, like carcrashanalysis, robot guiding, object recognition, supervision of 3D scenes, etc,. as well.

  16. A new cone-beam computed tomography system for dental applications with innovative 3D software

    Energy Technology Data Exchange (ETDEWEB)

    Pasini, Alessandro; Bianconi, D.; Rossi, A. [University of Bologna, Department of Physics, Bologna (Italy); NECTAR Imaging srl Imola (Italy); Casali, F. [University of Bologna, Department of Physics, Bologna (Italy); Bontempi, M. [CEFLA Dental Group Imola (Italy)

    2007-02-15

    Objective Cone beam computed tomography (CBCT) is an important image technique for oral surgery (dentoalveolar surgery and dental implantology) and maxillofacial applications. This technique requires compact sized scanners with a relatively low radiation dosage, which makes them suitable for imaging of the craniofacial region. This article aims to present the concept and the preliminary findings obtained with the prototype of a new CBCT scanner with dedicated 3D software, specifically designed for dental imaging. Methods The prototype implements an X-ray tube with a nominal focal spot of 0.5 mm operating at 70-100 kVp and 1-4 mA. The detector is a 6 in. image intensifier coupled with a digital CCD camera. Dosimetry was performed on a RANDO anthropomorphic phantom using Beryllium Oxide thermo-luminescent dosimeters positioned in the phantom in the following site: eyes, thyroid, skin (lips, cheeks, back of the neck), brain, mandible, maxilla and parotid glands. Doses were measured using four configurations, changing the field-of-view (4'' and 6'') and acquisition time (10 and 20 s) of the CBCT. Acquisitions were performed with different parameters regarding the x-ray tube, pixel size and acquisition geometries to evaluate image quality in relation to modulation transfer function (MTF), noise and geometric accuracy. Results The prototype was able to acquire a complete maxillofacial scan in 10-15 s. The CT reconstruction algorithm delivered images that were judged to have high quality, allowing for precise volume rendering. The radiation dose was determined to be 1-1.5 times that of the dose applied during conventional dental panoramic studies. Conclusion Preliminary studies using the CBCT prototype indicate that this device provides images with acceptable diagnostic content at a relatively low radiation dosage, if compared to systems currently available on the market. (orig.)

  17. 3D printing of preclinical X-ray computed tomographic data sets.

    Science.gov (United States)

    Doney, Evan; Krumdick, Lauren A; Diener, Justin M; Wathen, Connor A; Chapman, Sarah E; Stamile, Brian; Scott, Jeremiah E; Ravosa, Matthew J; Van Avermaete, Tony; Leevy, W Matthew

    2013-03-22

    Three-dimensional printing allows for the production of highly detailed objects through a process known as additive manufacturing. Traditional, mold-injection methods to create models or parts have several limitations, the most important of which is a difficulty in making highly complex products in a timely, cost-effective manner.(1) However, gradual improvements in three-dimensional printing technology have resulted in both high-end and economy instruments that are now available for the facile production of customized models.(2) These printers have the ability to extrude high-resolution objects with enough detail to accurately represent in vivo images generated from a preclinical X-ray CT scanner. With proper data collection, surface rendering, and stereolithographic editing, it is now possible and inexpensive to rapidly produce detailed skeletal and soft tissue structures from X-ray CT data. Even in the early stages of development, the anatomical models produced by three-dimensional printing appeal to both educators and researchers who can utilize the technology to improve visualization proficiency. (3, 4) The real benefits of this method result from the tangible experience a researcher can have with data that cannot be adequately conveyed through a computer screen. The translation of pre-clinical 3D data to a physical object that is an exact copy of the test subject is a powerful tool for visualization and communication, especially for relating imaging research to students, or those in other fields. Here, we provide a detailed method for printing plastic models of bone and organ structures derived from X-ray CT scans utilizing an Albira X-ray CT system in conjunction with PMOD, ImageJ, Meshlab, Netfabb, and ReplicatorG software packages.

  18. Computer numerical control (CNC) lithography: light-motion synchronized UV-LED lithography for 3D microfabrication

    Science.gov (United States)

    Kim, Jungkwun; Yoon, Yong-Kyu; Allen, Mark G.

    2016-03-01

    This paper presents a computer-numerical-controlled ultraviolet light-emitting diode (CNC UV-LED) lithography scheme for three-dimensional (3D) microfabrication. The CNC lithography scheme utilizes sequential multi-angled UV light exposures along with a synchronized switchable UV light source to create arbitrary 3D light traces, which are transferred into the photosensitive resist. The system comprises a switchable, movable UV-LED array as a light source, a motorized tilt-rotational sample holder, and a computer-control unit. System operation is such that the tilt-rotational sample holder moves in a pre-programmed routine, and the UV-LED is illuminated only at desired positions of the sample holder during the desired time period, enabling the formation of complex 3D microstructures. This facilitates easy fabrication of complex 3D structures, which otherwise would have required multiple manual exposure steps as in the previous multidirectional 3D UV lithography approach. Since it is batch processed, processing time is far less than that of the 3D printing approach at the expense of some reduction in the degree of achievable 3D structure complexity. In order to produce uniform light intensity from the arrayed LED light source, the UV-LED array stage has been kept rotating during exposure. UV-LED 3D fabrication capability was demonstrated through a plurality of complex structures such as V-shaped micropillars, micropanels, a micro-‘hi’ structure, a micro-‘cat’s claw,’ a micro-‘horn,’ a micro-‘calla lily,’ a micro-‘cowboy’s hat,’ and a micro-‘table napkin’ array.

  19. A 3D multilevel model of damage and strength of wood: Analysis of microstructural effects

    DEFF Research Database (Denmark)

    Qing, Hai; Mishnaevsky, Leon

    2011-01-01

    A 3D hierarchical computational model of damage and strength of wood is developed. The model takes into account the four scale microstructures of wood, including the microfibril reinforced structure at nanoscale, multilayered cell walls at microscale, hexagon-shape-tube cellular structure at meso...

  20. A 3D Computational Study on the Air-Blast Atomization of a Planar Liquid Layer

    Science.gov (United States)

    Chiodi, Robert; Desjardins, Olivier

    2016-11-01

    The air-blast atomization of a planar liquid layer is a complex fluid phenomenon involving the destabilization of a low speed liquid layer by a high speed gas coflow. While progress has been made in recent years on understanding the instability of the liquid surface, it remains difficult to accurately predict using stability analysis and requires special expertise and equipment to perform thorough experiments. Simulations provide an excellent way to conduct parametric studies to determine the effect of splitter plate geometry and momentum flux ratio on the frequency and wavelengths of instability, however, they are extremely difficult due to the high density ratio and large range of length and time scales present in the flow. Using an accurate conservative level set method in conjunction with a newly reformulated reinitialization equation, we perform 3D simulations of the air-blast atomization of a planar liquid layer and compare them to experiments. We then go on to explore the role momentum flux ratio plays in the longitudinal and transverse wavelengths of instability.

  1. Computed tomography study of VAPEX process in laboratory 3D model

    Energy Technology Data Exchange (ETDEWEB)

    Wu, G.Q.; Kantzas, A. [Calgary Univ., AB (Canada). Tomographic Imaging and Porous Media Laboratory; Salama, D. [Nexen Inc., Calgary, AB (Canada)

    2008-07-01

    This paper provided details of a 3-D laboratory model of the VAPEX process that used computerized tomography (CT) to examine vapour chamber expansion behaviour in longitudinal and radial directions. The model was comprised of an aluminum cylinder with 2 slotted tubes installed inside to act as injection and production wells. Propane was used as a solvent with heavy oil. The results of experiments conducted with the model showed that the V shape vapour chamber expansion pattern predicted by the 2-D model was a localized phenomenon. The dominant characteristic of the vapour chamber was an overriding of the injected solvent at the top of the model. The overriding was attributed to gravity segregation. The study also showed that longitudinal expansion was more significant than upwards expansion during the early stages of the VAPEX process. Oil production performance was then examined using different solvent injection rates. An analysis of the CT images was conducted to obtain model porosity, density, and oil saturation profiles. The study demonstrated that pressure cycles caused oil to be produced intermittently. Oil swelling by solvent gas dissolution was an important recovery mechanism. It was concluded that solvent soaking can be used to recover additional residual oil during the VAPEX process. 19 refs., 1 tab., 24 figs.

  2. Development, Verification and Use of Gust Modeling in the NASA Computational Fluid Dynamics Code FUN3D

    Science.gov (United States)

    Bartels, Robert E.

    2012-01-01

    This paper presents the implementation of gust modeling capability in the CFD code FUN3D. The gust capability is verified by computing the response of an airfoil to a sharp edged gust. This result is compared with the theoretical result. The present simulations will be compared with other CFD gust simulations. This paper also serves as a users manual for FUN3D gust analyses using a variety of gust profiles. Finally, the development of an Auto-Regressive Moving-Average (ARMA) reduced order gust model using a gust with a Gaussian profile in the FUN3D code is presented. ARMA simulated results of a sequence of one-minus-cosine gusts is shown to compare well with the same gust profile computed with FUN3D. Proper Orthogonal Decomposition (POD) is combined with the ARMA modeling technique to predict the time varying pressure coefficient increment distribution due to a novel gust profile. The aeroelastic response of a pitch/plunge airfoil to a gust environment is computed with a reduced order model, and compared with a direct simulation of the system in the FUN3D code. The two results are found to agree very well.

  3. 2D vs 3D gamma analysis: Establishment of comparable clinical action limits

    Directory of Open Access Journals (Sweden)

    Kiley B Pulliam

    2014-03-01

    Full Text Available Purpose: As clinics begin to use 3D metrics for intensity-modulated radiation therapy (IMRT quality assurance; these metrics will often produce results different from those produced by their 2D counterparts. 3D and 2D gamma analyses would be expected to produce different values, because of the different search space available. We compared the results of 2D and 3D gamma analysis (where both datasets were generated the same way for clinical treatment plans.                    Methods: 50 IMRT plans were selected from our database and recalculated using Monte Carlo. Treatment planning system-calculated (“evaluated” and Monte Carlo-recalculated (“reference” dose distributions were compared using 2D and 3D gamma analysis. This analysis was performed using a variety of dose-difference (5%, 3%, 2%, and 1% and distance-to-agreement (5, 3, 2, and 1 mm acceptance criteria, low-dose thresholds (5%, 10%, and 15% of the prescription dose, and data grid sizes (1.0, 1.5, and 3.0 mm. Each comparison was evaluated to determine the average 2D and 3D gamma and percentage of pixels passing gamma.Results: Average gamma and percentage of passing pixels for each acceptance criterion demonstrated better agreement for 3D than for 2D analysis for every plan comparison. Average difference in the percentage of passing pixels between the 2D and 3D analyses with no low-dose threshold ranged from 0.9% to 2.1%. Similarly, using a low-dose threshold resulted in a differences ranging from 0.8% to 1.5%. No appreciable differences in gamma with changes in the data density (constant difference: 0.8% for 2D vs. 3D were observed.Conclusion: We found that 3D gamma analysis resulted in up to 2.9% more pixels passing than 2D analysis.  Factors such as inherent dosimeter differences may be an important additional consideration to the extra dimension of available data that was evaluated in this study.------------------------------------Cite this article as

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Linear-Elastic 2D and 3D Finite Element Contact Analysis of a Hole Containing a Circular Insert in a Fatigue Test Coupon

    Science.gov (United States)

    2015-07-01

    UNCLASSIFIED UNCLASSIFIED Linear-Elastic 2D and 3D Finite Element Contact Analysis of a Hole Containing a Circular Insert in a Fatigue Test...circular hole in an aluminium plate fitted with a titanium fastener that were computed using two-dimensional finite element contact analysis . By...UNCLASSIFIED Linear-Elastic 2D and 3D Finite Element Contact Analysis of a Hole Containing a Circular Insert in a Fatigue Test Coupon

  6. 3D video analysis of the novel object recognition test in rats.

    Science.gov (United States)

    Matsumoto, Jumpei; Uehara, Takashi; Urakawa, Susumu; Takamura, Yusaku; Sumiyoshi, Tomiki; Suzuki, Michio; Ono, Taketoshi; Nishijo, Hisao

    2014-10-01

    The novel object recognition (NOR) test has been widely used to test memory function. We developed a 3D computerized video analysis system that estimates nose contact with an object in Long Evans rats to analyze object exploration during NOR tests. The results indicate that the 3D system reproducibly and accurately scores the NOR test. Furthermore, the 3D system captures a 3D trajectory of the nose during object exploration, enabling detailed analyses of spatiotemporal patterns of object exploration. The 3D trajectory analysis revealed a specific pattern of object exploration in the sample phase of the NOR test: normal rats first explored the lower parts of objects and then gradually explored the upper parts. A systematic injection of MK-801 suppressed changes in these exploration patterns. The results, along with those of previous studies, suggest that the changes in the exploration patterns reflect neophobia to a novel object and/or changes from spatial learning to object learning. These results demonstrate that the 3D tracking system is useful not only for detailed scoring of animal behaviors but also for investigation of characteristic spatiotemporal patterns of object exploration. The system has the potential to facilitate future investigation of neural mechanisms underlying object exploration that result from dynamic and complex brain activity.

  7. CS651 Computer Systems Security Foundations 3d Imagination Cyber Security Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Roy S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-03-02

    3d Imagination is a new company that bases its business on selling and improving 3d open source related hardware. The devices that they sell include 3d imagers, 3d printers, pick and place machines and laser etchers. They have a fast company intranet for ease in sharing, storing and printing large, complex 3d designs. They have an employee set that requires a variety of operating systems including Windows, Mac and a variety of Linux both for running business services as well as design and test machines. There are a wide variety of private networks for testing transfer rates to and from the 3d devices, without interference with other network tra c. They do video conferencing conferencing with customers and other designers. One of their machines is based on the project found at delta.firepick.org(Krassenstein, 2014; Biggs, 2014), which in future, will perform most of those functions. Their devices all include embedded systems, that may have full blown operating systems. Most of their systems are designed to have swappable parts, so when a new technology is born, it can be quickly adopted by people with 3d Imagination hardware. This company is producing a fair number of systems and components, however to get the funding they need to mass produce quality parts, so they are preparing for an IPO to raise the funds they need. They would like to have a cyber-security audit performed so they can give their investors con dence that they are protecting their data, customers information and printers in a proactive manner.

  8. Braking Distance Prediction by Hydroplaning Analysis of 3-D Patterned Tire Model

    Science.gov (United States)

    Cho, Jin-Rae; Choi, Joo-Hyoung; Lee, Hong-Woo; Woo, Jong-Shik; Yoo, Wan-Suk

    In this paper, we present a wet-road braking distance estimate for the vehicles equipped with ABS (Anti-lock Brake System). In order to effectively compute the interval-wise braking times and the resulting total braking distance, we divide the entire speed interval at braking into finite number of uniform sub-intervals and apply the energy conservation law to individual sub-intervals. The proposed method is based on a numerical-analytical approach such that the frictional energy loss of the patterned tire is computed by 3-D hydroplaning analysis while the other at the disc pad is analytically derived. The hydroplaning simulation is performed by generally coupling an Eulerian finite volume method and an explicit Lagrangian finite element method. The operation of ABS is numerically implemented by controlling the tire angular velocity such that the preset tire slip ratio on the wet road is maintained. Numerical results are presented to illustrative and verify the the proposed numerical estimate.

  9. Filtered chorochronic interface as a capability for 3-D unsteady throughflow analysis of multistage turbomachinery

    Science.gov (United States)

    Gerolymos, G. A.

    2013-02-01

    This note reviews the widely used phased-lagged [Erdos, J. L., E. Alzner, and W. McNally. 1977. AIAA Journal 15: 1559-68.] approach and corresponding chorochronic interface relations [Gerolymos G. A., G. J. Michon, and J. Neubauer. 2002. Journal of Propulsion and Power 18: 1139-52.] and explores its potential extension to the approximate unsteady throughflow analysis of multistage turbomachinery. The basic relations pertaining to the binary blade-row interaction case, for which chorochronic periodicity is exact in a phase-averaged rans framework, are briefly formulated, and selected computational examples illustrate the application of the method. Then, the filtered chorochronic interface is defined as the unsteady counterpart of the well-known mixing-plane concept. This interface takes into account only those tθ-waves which are compatible with the interaction of the immediately upstream and downstream blade-rows. The concept, which is similar to the decomposition-and-superposition method [Li, H. D., and L. He. 2005. ASME J ournal of Turbomachinery 127: 589-98.], is illustrated by 3-D computations of a ½-stage transonic compressor.

  10. Large deformation inelastic analysis of impact for shipping casks. [DYNA3D Code

    Energy Technology Data Exchange (ETDEWEB)

    Charman, C.M.; Grenier, R.M. (General Atomic Co., San Diego, CA (USA)); Nickell, R.E. (Applied Science and Technology, Poway, CA (USA))

    1982-09-01

    This paper describes the use of two- and three-dimensional nonlinear finite element computer programs to design a radioative material transportation cask to withstand a drop of 30 feet onto an unyielding surface. Because of recent advancement in the area of non-linear finite element code development, the use of such codes for an iterative design process is becoming practicable. The paper begins with a section dealing with a two-dimensional side drop analysis and is followed by a discussion of the general capabilities of DYNA3D and a brief discussion of the implementation of the code on a computational mainframe unlike any for which the developer had intended. Then, a section on three-dimensional models of center-of-gravity over a corner impact follows, which introduces design features such as bolted closures, internal impact limiter, seals and shear rings. Figs. showing the deformed model grids are included. Stress and strain results are given in the subsequent section. Finally, we interpret these results in terms of possible rules being developed by the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code committees.

  11. 2D and 3D stability analysis of slurry trench in frictional/cohesive soil

    Institute of Scientific and Technical Information of China (English)

    Chang-yu HAN; Jin-jian CHEN; Jian-hua WANG; Xiao-he XIA

    2013-01-01

    A 2D and 3D kinematically admissible rotational failure mechanism is presented for homogeneous slurry trenches in frictional/cohesive soils.Analytical approaches are derived to obtain the upper bounds on slurry trench stability in the strict framework of limit analysis.It is shown that the factor of safety from a 3D analysis will be greater than that from a 2D analysis.Compared with the limit equilibrium method,the limit analysis method yields an unconservative estimate on the safety factors.A set of examples are presented in a wide range of parameters for 2D and 3D homogeneous slurry trenches.The factor of safety increases with increasing slurry and soil bulk density ratio,cohesion,friction angle,and with decreasing slurry level depth and trench depth ratio,trench width and depth ratio.It is convenient to assess the safety for the homogeneous slurry trenches in practical applications.

  12. 3D Nondestructive Visualization and Evaluation of TRISO Particles Distribution in HTGR Fuel Pebbles Using Cone-Beam Computed Tomography

    Directory of Open Access Journals (Sweden)

    Gongyi Yu

    2017-01-01

    Full Text Available A nonuniform distribution of tristructural isotropic (TRISO particles within a high-temperature gas-cooled reactor (HTGR pebble may lead to excessive thermal gradients and nonuniform thermal expansion during operation. If the particles are closely clustered, local hotspots may form, leading to excessive stresses on particle layers and an increased probability of particle failure. Although X-ray digital radiography (DR is currently used to evaluate the TRISO distributions in pebbles, X-ray DR projection images are two-dimensional in nature, which would potentially miss some details for 3D evaluation. This paper proposes a method of 3D visualization and evaluation of the TRISO distribution in HTGR pebbles using cone-beam computed tomography (CBCT: first, a pebble is scanned on our high-resolution CBCT, and 2D cross-sectional images are reconstructed; secondly, all cross-sectional images are restructured to form the 3D model of the pebble; then, volume rendering is applied to segment and display the TRISO particles in 3D for visualization and distribution evaluation. For method validation, several pebbles were scanned and the 3D distributions of the TRISO particles within the pebbles were produced. Experiment results show that the proposed method provides more 3D than DR, which will facilitate pebble fabrication research and production quality control.

  13. Molecular determinants of juvenile hormone action as revealed by 3D QSAR analysis in Drosophila.

    Directory of Open Access Journals (Sweden)

    Denisa Liszeková

    Full Text Available BACKGROUND: Postembryonic development, including metamorphosis, of many animals is under control of hormones. In Drosophila and other insects these developmental transitions are regulated by the coordinate action of two principal hormones, the steroid ecdysone and the sesquiterpenoid juvenile hormone (JH. While the mode of ecdysone action is relatively well understood, the molecular mode of JH action remains elusive. METHODOLOGY/PRINCIPAL FINDINGS: To gain more insights into the molecular mechanism of JH action, we have tested the biological activity of 86 structurally diverse JH agonists in Drosophila melanogaster. The results were evaluated using 3D QSAR analyses involving CoMFA and CoMSIA procedures. Using this approach we have generated both computer-aided and species-specific pharmacophore fingerprints of JH and its agonists, which revealed that the most active compounds must possess an electronegative atom (oxygen or nitrogen at both ends of the molecule. When either of these electronegative atoms are replaced by carbon or the distance between them is shorter than 11.5 A or longer than 13.5 A, their biological activity is dramatically decreased. The presence of an electron-deficient moiety in the middle of the JH agonist is also essential for high activity. CONCLUSIONS/SIGNIFICANCE: The information from 3D QSAR provides guidelines and mechanistic scope for identification of steric and electrostatic properties as well as donor and acceptor hydrogen-bonding that are important features of the ligand-binding cavity of a JH target protein. In order to refine the pharmacophore analysis and evaluate the outcomes of the CoMFA and CoMSIA study we used pseudoreceptor modeling software PrGen to generate a putative binding site surrogate that is composed of eight amino acid residues corresponding to the defined molecular interactions.

  14. 3D volume assessment techniques and computer-aided design and manufacturing for preoperative fabrication of implants in head and neck reconstruction.

    Science.gov (United States)

    Patel, Ashish; Otterburn, David; Saadeh, Pierre; Levine, Jamie; Hirsch, David L

    2011-11-01

    Cases in subdisciplines of craniomaxillofacial surgery--corrective jaw surgery, maxillofacial trauma, temporomandibular joint/skull base, jaw reconstruction, and postablative reconstruction-illustrate the ease of use, cost effectiveness, and superior results that can be achieved when using computer-assisted design and 3D volumetric analysis in preoperative surgical planning. This article discusses the materials and methods needed to plan cases, illustrates implementation of guides and implants, and describes postoperative analysis in relation to the virtually planned surgery.

  15. A collaborative computing framework of cloud network and WBSN applied to fall detection and 3-D motion reconstruction.

    Science.gov (United States)

    Lai, Chin-Feng; Chen, Min; Pan, Jeng-Shyang; Youn, Chan-Hyun; Chao, Han-Chieh

    2014-03-01

    As cloud computing and wireless body sensor network technologies become gradually developed, ubiquitous healthcare services prevent accidents instantly and effectively, as well as provides relevant information to reduce related processing time and cost. This study proposes a co-processing intermediary framework integrated cloud and wireless body sensor networks, which is mainly applied to fall detection and 3-D motion reconstruction. In this study, the main focuses includes distributed computing and resource allocation of processing sensing data over the computing architecture, network conditions and performance evaluation. Through this framework, the transmissions and computing time of sensing data are reduced to enhance overall performance for the services of fall events detection and 3-D motion reconstruction.

  16. FRICTIONAL CONTACT MULTIPOLE-BEM AND 3-D ANALYSIS OF SCREWPAIRS

    Institute of Scientific and Technical Information of China (English)

    Chen Xiumin; Shen Guangxian; Liu Deyi

    2004-01-01

    The 3-D traction field in the pressure screw-pair of a 3 500 heavy and medium plate mill press down system is successfully calculated by applying the 3-D frictional contact multipole-BEM and the corresponding program that has been developed. The computing results show the medium diameter orientation is unreliable, especially under the interference of an outer force couple. Under such working conditions, the circumferential traction distribution on the screw teeth is extremely uneven, which is the main reason for the destruction and short life time of screw-pairs. When utilizing the same precision (the relative tolerance is 10×10-5),the mltipole-BEM uses almost the CPU time as used by the FEM,but the needed computer menory size is only one eighieth of that needed by the FEM(10 MB vs.800 MB).The multipole-BEM is well suited for computing large-scale engineering problems.

  17. 3D Numerical Simulation Analysis of Passive Drag near Free Surface in Swimming

    Institute of Scientific and Technical Information of China (English)

    詹杰民; 李天赠; 陈学彬; 李毓湘; 韦永康

    2015-01-01

    The aim of this work is to build a 3D numerical model to study the characteristics of passive drag on competitive swimmers taking into account the impact of the free surface. This model solves the 3D incompressible Navier-Stokes equations using RNG k-εturbulence closure. The volume of fluid (VOF) method is used to locate the free surface. The 3D virtual model is created by Computer Aided Industrial Design (CAID) software, Rhinoceros. Firstly, a specific posture of swimming is studied. The simulation results are in good agreement with the data from mannequin towing experiments. The effects of a swimmer’s arms and legs positions on swimming performance are then studied. Finally, it is demonstrated that the present method is capable of simulating gliding near the free surface.

  18. 3D numerical simulation analysis of passive drag near free surface in swimming

    Science.gov (United States)

    Zhan, Jie-min; Li, Tian-zeng; Chen, Xue-bin; Li, Yok-sheung; Wai, Wing-hong Onyx

    2015-04-01

    The aim of this work is to build a 3D numerical model to study the characteristics of passive drag on competitive swimmers taking into account the impact of the free surface. This model solves the 3D incompressible Navier-Stokes equations using RNG k- ɛ turbulence closure. The volume of fluid (VOF) method is used to locate the free surface. The 3D virtual model is created by Computer Aided Industrial Design (CAID) software, Rhinoceros. Firstly, a specific posture of swimming is studied. The simulation results are in good agreement with the data from mannequin towing experiments. The effects of a swimmer's arms and legs positions on swimming performance are then studied. Finally, it is demonstrated that the present method is capable of simulating gliding near the free surface.

  19. Cardiac tissue structure. Electric field interactions in polarizing the heart: 3D computer models and applications

    Science.gov (United States)

    Entcheva, Emilia

    1998-11-01

    The goal of this research is to investigate the interactions between the cardiac tissue structure and applied electric fields in producing complex polarization patterns. It is hypothesized that the response of the heart in the conditions of strong electric shocks, as those applied in defibrillation, is dominated by mechanisms involving the cardiac muscle structure perceived as a continuum. Analysis is carried out in three-dimensional models of the heart with detailed fiber architecture. Shock-induced transmembrane potentials are calculated using the bidomain model in its finite element implementation. The major new findings of this study can be summarized as follows: (1) The mechanisms of polarization due to cardiac fiber curvature and fiber rotation are elucidated in three-dimensional ellipsoidal hearts of variable geometry; (2) Results are presented showing that the axis of stimulation and the polarization axis on a whole heart level might differ significantly due to geometric and anisotropic factors; (3) Virtual electrode patterns are demonstrated numerically inside the ventricular wall in internal defibrillation conditions. The role of the tissue-bath interface in shaping the shock-induced polarization is revealed; (4) The generation of 3D phase singularity scrolls by shock-induced intramural virtual electrode patterns is proposed as evidence for a possible new mechanism for the failure to defibrillate. The results of this study emphasize the role of unequal anisotropy in the intra- and extracellular domains, as well as the salient fiber architecture characteristics, such as curvature and transmural rotation, in polarizing the myocardium. Experimental support of the above findings was actively sought and found in recent optical mapping studies using voltage-sensitive dyes. If validated in vivo, these findings would significantly enrich the prevailing concepts about the mechanisms of stimulation and defibrillation of the heart.

  20. 3D finite element analysis of porous Ti-based alloy prostheses.

    Science.gov (United States)

    Mircheski, Ile; Gradišar, Marko

    2016-11-01

    In this paper, novel designs of porous acetabular cups are created and tested with 3D finite element analysis (FEA). The aim is to develop a porous acetabular cup with low effective radial stiffness of the structure, which will be near to the architectural and mechanical behavior of the natural bone. For the realization of this research, a 3D-scanner technology was used for obtaining a 3D-CAD model of the pelvis bone, a 3D-CAD software for creating a porous acetabular cup, and a 3D-FEA software for virtual testing of a novel design of the porous acetabular cup. The results obtained from this research reveal that a porous acetabular cup from Ti-based alloys with 60 ± 5% porosity has the mechanical behavior and effective radial stiffness (Young's modulus in radial direction) that meet and exceed the required properties of the natural bone. The virtual testing with 3D-FEA of a novel design with porous structure during the very early stage of the design and the development of orthopedic implants, enables obtaining a new or improved biomedical implant for a relatively short time and reduced price.

  1. Mathematical modeling and reliability analysis of a 3D Li-ion battery

    Directory of Open Access Journals (Sweden)

    RICHARD HONG PENG LIANG

    2014-02-01

    Full Text Available The three-dimensional (3D Li-ion battery presents an effective solution to issues affecting its two-dimensional counterparts, as it is able to attain high energy capacities for the same areal footprint without sacrificing power density. A 3D battery has key structural features extending in and fully utilizing 3D space, allowing it to achieve greater reliability and longevity. This study applies an electrochemical-thermal coupled model to a checkerboard array of alternating positive and negative electrodes in a 3D architecture with either square or circular electrodes. The mathematical model comprises the transient conservation of charge, species, and energy together with electroneutrality, constitutive relations and relevant initial and boundary conditions. A reliability analysis carried out to simulate malfunctioning of either a positive or negative electrode reveals that although there are deviations in electrochemical and thermal behavior for electrodes adjacent to the malfunctioning electrode as compared to that in a fully-functioning array, there is little effect on electrodes further away, demonstrating the redundancy that a 3D electrode array provides. The results demonstrate that implementation of 3D batteries allow it to reliably and safely deliver power even if a component malfunctions, a strong advantage over conventional 2D batteries.

  2. How computer science can help in understanding the 3D genome architecture.

    Science.gov (United States)

    Shavit, Yoli; Merelli, Ivan; Milanesi, Luciano; Lio', Pietro

    2016-09-01

    Chromosome conformation capture techniques are producing a huge amount of data about the architecture of our genome. These data can provide us with a better understanding of the events that induce critical regulations of the cellular function from small changes in the three-dimensional genome architecture. Generating a unified view of spatial, temporal, genetic and epigenetic properties poses various challenges of data analysis, visualization, integration and mining, as well as of high performance computing and big data management. Here, we describe the critical issues of this new branch of bioinformatics, oriented at the comprehension of the three-dimensional genome architecture, which we call 'Nucleome Bioinformatics', looking beyond the currently available tools and methods, and highlight yet unaddressed challenges and the potential approaches that could be applied for tackling them. Our review provides a map for researchers interested in using computer science for studying 'Nucleome Bioinformatics', to achieve a better understanding of the biological processes that occur inside the nucleus.

  3. Evaluation of the durability of 3D printed keys produced by computational processing of image data

    Science.gov (United States)

    Straub, Jeremy; Kerlin, Scott

    2016-05-01

    Possession of a working 3D printed key can, for most practical purposes, convince observers that an illicit attempt to gain premises access is authorized. This paper seeks to assess three things. First, work has been performed to determine how easily the data for making models of keys can be obtained through manual measurement. It then presents work done to create a model of the key and determine how easy key modeling could be (particularly after a first key of a given key `blank' has been made). Finally, it seeks to assess the durability of the keys produced using 3D printing.

  4. A detailed 3D finite element analysis of the peeling behaviour of a gecko spatula

    NARCIS (Netherlands)

    Sauer, R.A.; Holl, M.

    2013-01-01

    This paper presents a detailed finite element analysis of the adhesion of a gecko spatula. The gecko spatulae form the tips of the gecko foot hairs that transfer the adhesional and frictional forces between substrate and foot. The analysis is based on a parameterised description of the 3D geometry o

  5. 3D FACE RECOGNITION FROM RANGE IMAGES BASED ON CURVATURE ANALYSIS

    Directory of Open Access Journals (Sweden)

    Suranjan Ganguly

    2014-02-01

    Full Text Available In this paper, we present a novel approach for three-dimensional face recognition by extracting the curvature maps from range images. There are four types of curvature maps: Gaussian, Mean, Maximum and Minimum curvature maps. These curvature maps are used as a feature for 3D face recognition purpose. The dimension of these feature vectors is reduced using Singular Value Decomposition (SVD technique. Now from calculated three components of SVD, the non-negative values of ‘S’ part of SVD is ranked and used as feature vector. In this proposed method, two pair-wise curvature computations are done. One is Mean, and Maximum curvature pair and another is Gaussian and Mean curvature pair. These are used to compare the result for better recognition rate. This automated 3D face recognition system is focused in different directions like, frontal pose with expression and illumination variation, frontal face along with registered face, only registered face and registered face from different pose orientation across X, Y and Z axes. 3D face images used for this research work are taken from FRAV3D database. The pose variation of 3D facial image is being registered to frontal pose by applying one to all registration technique then curvature mapping is applied on registered face images along with remaining frontal face images. For the classification and recognition purpose five layer feed-forward back propagation neural network classifiers is used, and the corresponding result is discussed in section 4.

  6. Segmentation of vascular structures and hematopoietic cells in 3D microscopy images and quantitative analysis

    Science.gov (United States)

    Mu, Jian; Yang, Lin; Kamocka, Malgorzata M.; Zollman, Amy L.; Carlesso, Nadia; Chen, Danny Z.

    2015-03-01

    In this paper, we present image processing methods for quantitative study of how the bone marrow microenvironment changes (characterized by altered vascular structure and hematopoietic cell distribution) caused by diseases or various factors. We develop algorithms that automatically segment vascular structures and hematopoietic cells in 3-D microscopy images, perform quantitative analysis of the properties of the segmented vascular structures and cells, and examine how such properties change. In processing images, we apply local thresholding to segment vessels, and add post-processing steps to deal with imaging artifacts. We propose an improved watershed algorithm that relies on both intensity and shape information and can separate multiple overlapping cells better than common watershed methods. We then quantitatively compute various features of the vascular structures and hematopoietic cells, such as the branches and sizes of vessels and the distribution of cells. In analyzing vascular properties, we provide algorithms for pruning fake vessel segments and branches based on vessel skeletons. Our algorithms can segment vascular structures and hematopoietic cells with good quality. We use our methods to quantitatively examine the changes in the bone marrow microenvironment caused by the deletion of Notch pathway. Our quantitative analysis reveals property changes in samples with deleted Notch pathway. Our tool is useful for biologists to quantitatively measure changes in the bone marrow microenvironment, for developing possible therapeutic strategies to help the bone marrow microenvironment recovery.

  7. Advanced 3D textile composites reinforcements meso F.E analyses based on X-ray computed tomography

    Science.gov (United States)

    Naouar, Naim; Vidal-Salle, Emmanuelle; Boisse, Philippe

    2016-10-01

    Meso-FE modelling of 3D textile composites is a powerful tool, which can help determine mechanical properties and permeability of the reinforcements or composites. The quality of the meso FE analyses depends on the quality of the initial model. A direct method based on X-ray tomography imaging is introduced to determine finite element models based on the real geometry of 3D composite reinforcements. The method is particularly suitable regarding 3D textile reinforcements for which internal geometries are numerous and complex. The approach used for the separation of the yarns in different directions is specialized because the fibres flow in three-dimensional space. An analysis of the image's texture is performed. A hyperelastic model developed for fibre bundles is used for the simulation of the deformation of the 3D reinforcement.

  8. Visualization and analysis of 3D gene expression patterns in zebrafish using web services

    Science.gov (United States)

    Potikanond, D.; Verbeek, F. J.

    2012-01-01

    The analysis of patterns of gene expression patterns analysis plays an important role in developmental biology and molecular genetics. Visualizing both quantitative and spatio-temporal aspects of gene expression patterns together with referenced anatomical structures of a model-organism in 3D can help identifying how a group of genes are expressed at a certain location at a particular developmental stage of an organism. In this paper, we present an approach to provide an online visualization of gene expression data in zebrafish (Danio rerio) within 3D reconstruction model of zebrafish in different developmental stages. We developed web services that provide programmable access to the 3D reconstruction data and spatial-temporal gene expression data maintained in our local repositories. To demonstrate this work, we develop a web application that uses these web services to retrieve data from our local information systems. The web application also retrieve relevant analysis of microarray gene expression data from an external community resource; i.e. the ArrayExpress Atlas. All the relevant gene expression patterns data are subsequently integrated with the reconstruction data of the zebrafish atlas using ontology based mapping. The resulting visualization provides quantitative and spatial information on patterns of gene expression in a 3D graphical representation of the zebrafish atlas in a certain developmental stage. To deliver the visualization to the user, we developed a Java based 3D viewer client that can be integrated in a web interface allowing the user to visualize the integrated information over the Internet.

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

    Science.gov (United States)

    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.

  10. Statistical 2D and 3D shape analysis using Non-Euclidean Metrics

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Hilger, Klaus Baggesen; Wrobel, Mark Christoph

    2002-01-01

    We address the problem of extracting meaningful, uncorrelated biological modes of variation from tangent space shape coordinates in 2D and 3D using non-Euclidean metrics. We adapt the maximum autocorrelation factor analysis and the minimum noise fraction transform to shape decomposition. Furtherm......We address the problem of extracting meaningful, uncorrelated biological modes of variation from tangent space shape coordinates in 2D and 3D using non-Euclidean metrics. We adapt the maximum autocorrelation factor analysis and the minimum noise fraction transform to shape decomposition...

  11. Computational Graph Model for 3D Cells Tracking in Zebra Fish Datasets

    Science.gov (United States)

    Zhang, Lelin; Xiong, Hongkai; Zhao, Yang; Zhang, Kai; Zhou, Xiaobo

    2007-11-01

    This paper leads to a novel technique for tracking and identification of zebra-fish cells in 3D image sequences, extending graph-based multi-objects tracking algorithm to 3D applications. As raised in previous work of 2D graph-based method, separated cells are modeled as vertices that connected by edges. Then the tracking work is simplified to that of vertices matching between graphs generated from consecutive frames. Graph-based tracking is composed of three steps: graph generation, initial source vertices selection and graph saturation. To satisfy demands in this work separated cell records are segmented from original datasets using 3D level-set algorithms. Besides, advancements are achieved in each of the step including graph regulations, multi restrictions on source vertices and enhanced flow quantifications. Those strategies make a good compensation for graph-based multi-objects tracking method in 2D space. Experiments are carried out in 3D datasets sampled from zebra fish, results of which shows that this enhanced method could be potentially applied to tracking of objects with diverse features.

  12. 3D Printing Meets Computational Astrophysics: Deciphering the Structure of Eta Carinae’s Colliding Winds Using 3D Prints of Smoothed Particle Hydrodynamics Simulations

    Science.gov (United States)

    Madura, Thomas; Gull, Theodore R.; Clementel, Nicola; Paardekooper, Jan-Pieter; Kruip, Chael; Corcoran, Michael F.; Hamaguchi, Kenji; Teodoro, Mairan

    2015-01-01

    We present the first 3D prints of output from a supercomputer simulation of a complex astrophysical system, the colliding stellar winds in the massive (>120 MSun), highly eccentric (e ~ 0.9) binary Eta Carinae. Using a consumer-grade 3D printer (Makerbot Replicator 2X), we successfully printed 3D smoothed particle hydrodynamics simulations of Eta Carinae's inner (r ~110 AU) wind-wind collision interface at multiple orbital phases. These 3D prints reveal important, previously unknown 'finger-like' structures at orbital phases shortly after periastron (φ ~1.045) that protrude radially outward from the spiral wind-wind collision region. We speculate that these fingers are related to instabilities (e.g. Rayleigh-Taylor) that arise at the interface between the radiatively-cooled layer of dense post-shock primary-star wind and the hot, adiabatic post-shock companion-star wind. The success of our work and easy identification of previously unknown physical features highlight the important role 3D printing can play in the visualization and understanding of complex 3D time-dependent numerical simulations of astrophysical phenomena.

  13. Lung nodule detection performance in five observers on computed tomography (CT) with adaptive iterative dose reduction using three-dimensional processing (AIDR 3D) in a Japanese multicenter study: Comparison between ultra-low-dose CT and low-dose CT by receiver-operating characteristic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nagatani, Yukihiro, E-mail: yatsushi@belle.shiga-med.ac.jp [Department of Radiology, Shiga University of Medical Science, Otsu 520-2192, Shiga (Japan); Takahashi, Masashi; Murata, Kiyoshi [Department of Radiology, Shiga University of Medical Science, Otsu 520-2192, Shiga (Japan); Ikeda, Mitsuru [Department of Radiological and Medical Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya 461-8673, Aichi (Japan); Yamashiro, Tsuneo [Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara 903-0215, Okinawa (Japan); Miyara, Tetsuhiro [Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara 903-0215, Okinawa (Japan); Department of Radiology, Okinawa Prefectural Yaeyama Hospital, Ishigaki 907-0022, Okinawa (Japan); Koyama, Hisanobu [Department of Radiology, Kobe University Graduate School of Medicine, Kobe 650-0017, Hyogo (Japan); Koyama, Mitsuhiro [Department of Radiology, Osaka Medical College, Takatsuki 569-8686, Osaka (Japan); Sato, Yukihisa [Department of Radiology, Osaka University Graduate School of Medicine, Suita 565-0871, Osaka (Japan); Department of Radiology, Osaka Medical Center of Cancer and Cardiovascular Diseases, Osaka 537-8511, Osaka (Japan); Moriya, Hiroshi [Department of Radiology, Ohara General Hospital, Fukushima 960-8611 (Japan); Noma, Satoshi [Department of Radiology, Tenri Hospital, Tenri 632-8552, Nara (Japan); Tomiyama, Noriyuki [Department of Radiology, Osaka University Graduate School of Medicine, Suita 565-0871, Osaka (Japan); Ohno, Yoshiharu [Department of Radiology, Kobe University Graduate School of Medicine, Kobe 650-0017, Hyogo (Japan); Murayama, Sadayuki [Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara 903-0215, Okinawa (Japan)

    2015-07-15

    Highlights: • Using AIDR 3D, ULDCT showed comparable LND of solid nodules to LDCT. • Using AIDR 3D, LND of smaller GGN in ULDCT was inferior to that in LDCT. • Effective dose in ULDCT was about only twice of that in chest X-ray. • BMI values in study population were mostly in the normal range body habitus. - Abstract: Purpose: To compare lung nodule detection performance (LNDP) in computed tomography (CT) with adaptive iterative dose reduction using three dimensional processing (AIDR3D) between ultra-low dose CT (ULDCT) and low dose CT (LDCT). Materials and methods: This was part of the Area-detector Computed Tomography for the Investigation of Thoracic Diseases (ACTIve) Study, a multicenter research project being conducted in Japan. Institutional Review Board approved this study and informed consent was obtained. Eighty-three subjects (body mass index, 23.3 ± 3.2) underwent chest CT at 6 institutions using identical scanners and protocols. In a single visit, each subject was scanned using different tube currents: 240, 120 and 20 mA (3.52, 1.74 and 0.29 mSv, respectively). Axial CT images with 2-mm thickness/increment were reconstructed using AIDR3D. Standard of reference (SOR) was determined based on CT images at 240 mA by consensus reading of 2 board-certificated radiologists as to the presence of lung nodules with the longest diameter (LD) of more than 3 mm. Another 5 radiologists independently assessed and recorded presence/absence of lung nodules and their locations by continuously-distributed rating in CT images at 20 mA (ULDCT) and 120 mA (LDCT). Receiver-operating characteristic (ROC) analysis was used to evaluate LNDP of both methods in total and also in subgroups classified by LD (>4, 6 and 8 mm) and nodular characteristics (solid and ground glass nodules). Results: For SOR, 161 solid and 60 ground glass nodules were identified. No significant difference in LNDP for entire solid nodules was demonstrated between both methods, as area under ROC

  14. Computer system to manage information rigs by 3D electronic models; Sistema computacional para administrar la informacion de plataformas petroleras mediante modelos electronicos 3D

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez Bustos, Jesus; Segura Ozuna, Victor Octavio [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2012-06-22

    The evolution and incorporation of new hardware technologies, as well as recent advances in computer systems have enabled the development of applications of computer aided design of most complete scope, such as those used for the design of industrial process plants. This article describes a software system developed to complement the capabilities of one of these systems for the design of process plants. A 3D electronic model is generated through the user interface of the design system that at the same time gives the user the ability to generate, publish, review and control the engineering document that are generated during the entire life cycle of a marine oil platform, a very particular type of industrial process plant. This way, the user obtains not only a tool for the design of an industrial plant, but also a system for managing information and engineering documents that are developed. This allows the user to do a more efficient job by putting at his disposal and in the same system, all documents and information required to perform his duty. [Spanish] La evolucion e incorporacion de nuevas tecnologias de hardware, junto con los avances recientes en sistemas de computo ha permitido el desarrollo de aplicaciones de interesante diseno de computo de mayor alcance, tales como los que se emplean en las plantas de procesos industriales. Este articulo describe un sistema de software desarrollado para complementar las capacidades de uno de estos sistemas para el diseno de proceso. Un modelo electronico se genera por medio de la interfaz de usuario del sistema de diseno, que al mismo tiempo da al usuario la capacidad para crear, publicar, revisar y controlar los documentos de ingenieria que se producen durante el ciclo de vida completo de una plataforma marina petrolera, un tipo muy particular de planta de proceso industrial. De este modo, el usuario no solo obtiene una herramienta para el diseno de una planta industrial, sino tambien un sistema para manejar informacion y

  15. Open Plot Project: an open-source toolkit for 3-D structural data analysis

    Directory of Open Access Journals (Sweden)

    S. Tavani

    2010-12-01

    Full Text Available In this work we present the Open Plot Project, a software for structural data analysis including a 3-D environment. This first alpha release represents a stand-alone toolkit for structural data analysis and, due to many import/export facilities and to the presence of a 3-D environment, also candidates as a tool to be incorporated in workflows for 3-D geological modelling.

    The software (for both Windows and Linux O.S., the User Manual, a set of example movies, and the source code are provided as Supplement. It is our purpose that the publication of the source code sets the base for the development of a public and free software that, hopefully, the structural geologists community will use, modify, and implement. The creation of additional public controls/tools is strongly encouraged.

  16. Digital Curvatures Applied to 3D Object Analysis and Recognition: A Case Study

    CERN Document Server

    Chen, Li

    2009-01-01

    In this paper, we propose using curvatures in digital space for 3D object analysis and recognition. Since direct adjacency has only six types of digital surface points in local configurations, it is easy to determine and classify the discrete curvatures for every point on the boundary of a 3D object. Unlike the boundary simplicial decomposition (triangulation), the curvature can take any real value. It sometimes makes difficulties to find a right value for threshold. This paper focuses on the global properties of categorizing curvatures for small regions. We use both digital Gaussian curvatures and digital mean curvatures to 3D shapes. This paper proposes a multi-scale method for 3D object analysis and a vector method for 3D similarity classification. We use these methods for face recognition and shape classification. We have found that the Gaussian curvatures mainly describe the global features and average characteristics such as the five regions of a human face. However, mean curvatures can be used to find ...

  17. 3D texture analysis for classification of second harmonic generation images of human ovarian cancer

    Science.gov (United States)

    Wen, Bruce; Campbell, Kirby R.; Tilbury, Karissa; Nadiarnykh, Oleg; Brewer, Molly A.; Patankar, Manish; Singh, Vikas; Eliceiri, Kevin. W.; Campagnola, Paul J.

    2016-10-01

    Remodeling of the collagen architecture in the extracellular matrix (ECM) has been implicated in ovarian cancer. To quantify these alterations we implemented a form of 3D texture analysis to delineate the fibrillar morphology observed in 3D Second Harmonic Generation (SHG) microscopy image data of normal (1) and high risk (2) ovarian stroma, benign ovarian tumors (3), low grade (4) and high grade (5) serous tumors, and endometrioid tumors (6). We developed a tailored set of 3D filters which extract textural features in the 3D image sets to build (or learn) statistical models of each tissue class. By applying k-nearest neighbor classification using these learned models, we achieved 83-91% accuracies for the six classes. The 3D method outperformed the analogous 2D classification on the same tissues, where we suggest this is due the increased information content. This classification based on ECM structural changes will complement conventional classification based on genetic profiles and can serve as an additional biomarker. Moreover, the texture analysis algorithm is quite general, as it does not rely on single morphological metrics such as fiber alignment, length, and width but their combined convolution with a customizable basis set.

  18. Generating 3D anatomically detailed models of the retina from OCT data sets: implications for computational modelling

    Science.gov (United States)

    Shalbaf, Farzaneh; Dokos, Socrates; Lovell, Nigel H.; Turuwhenua, Jason; Vaghefi, Ehsan

    2015-12-01

    Retinal prosthesis has been proposed to restore vision for those suffering from the retinal pathologies that mainly affect the photoreceptors layer but keep the inner retina intact. Prior to costly risky experimental studies computational modelling of the retina will help to optimize the device parameters and enhance the outcomes. Here, we developed an anatomically detailed computational model of the retina based on OCT data sets. The consecutive OCT images of individual were subsequently segmented to provide a 3D representation of retina in the form of finite elements. Thereafter, the electrical properties of the retina were modelled by implementing partial differential equation on the 3D mesh. Different electrode configurations, that is bipolar and hexapolar configurations, were implemented and the results were compared with the previous computational and experimental studies. Furthermore, the possible effects of the curvature of retinal layers on the current steering through the retina were proposed and linked to the clinical observations.

  19. Semantic segmentation of 3D textured meshes for urban scene analysis

    Science.gov (United States)

    Rouhani, Mohammad; Lafarge, Florent; Alliez, Pierre

    2017-01-01

    Classifying 3D measurement data has become a core problem in photogrammetry and 3D computer vision, since the rise of modern multiview geometry techniques, combined with affordable range sensors. We introduce a Markov Random Field-based approach for segmenting textured meshes generated via multi-view stereo into urban classes of interest. The input mesh is first partitioned into small clusters, referred to as superfacets, from which geometric and photometric features are computed. A random forest is then trained to predict the class of each superfacet as well as its similarity with the neighboring superfacets. Similarity is used to assign the weights of the Markov Random Field pairwise-potential and to account for contextual information between the classes. The experimental results illustrate the efficacy and accuracy of the proposed framework.

  20. Computer-aided multiple-head 3D printing system for printing of heterogeneous organ/tissue constructs

    Science.gov (United States)

    Jung, Jin Woo; Lee, Jung-Seob; Cho, Dong-Woo

    2016-02-01

    Recently, much attention has focused on replacement or/and enhancement of biological tissues via the use of cell-laden hydrogel scaffolds with an architecture that mimics the tissue matrix, and with the desired three-dimensional (3D) external geometry. However, mimicking the heterogeneous tissues that most organs and tissues are formed of is challenging. Although multiple-head 3D printing systems have been proposed for fabricating heterogeneous cell-laden hydrogel scaffolds, to date only the simple exterior form has been realized. Here we describe a computer-aided design and manufacturing (CAD/CAM) system for this application. We aim to develop an algorithm to enable easy, intuitive design and fabrication of a heterogeneous cell-laden hydrogel scaffolds with a free-form 3D geometry. The printing paths of the scaffold are automatically generated from the 3D CAD model, and the scaffold is then printed by dispensing four materials; i.e., a frame, two kinds of cell-laden hydrogel and a support. We demonstrated printing of heterogeneous tissue models formed of hydrogel scaffolds using this approach, including the outer ear, kidney and tooth tissue. These results indicate that this approach is particularly promising for tissue engineering and 3D printing applications to regenerate heterogeneous organs and tissues with tailored geometries to treat specific defects or injuries.

  1. Computer-aided multiple-head 3D printing system for printing of heterogeneous organ/tissue constructs.

    Science.gov (United States)

    Jung, Jin Woo; Lee, Jung-Seob; Cho, Dong-Woo

    2016-02-22

    Recently, much attention has focused on replacement or/and enhancement of biological tissues via the use of cell-laden hydrogel scaffolds with an architecture that mimics the tissue matrix, and with the desired three-dimensional (3D) external geometry. However, mimicking the heterogeneous tissues that most organs and tissues are formed of is challenging. Although multiple-head 3D printing systems have been proposed for fabricating heterogeneous cell-laden hydrogel scaffolds, to date only the simple exterior form has been realized. Here we describe a computer-aided design and manufacturing (CAD/CAM) system for this application. We aim to develop an algorithm to enable easy, intuitive design and fabrication of a heterogeneous cell-laden hydrogel scaffolds with a free-form 3D geometry. The printing paths of the scaffold are automatically generated from the 3D CAD model, and the scaffold is then printed by dispensing four materials; i.e., a frame, two kinds of cell-laden hydrogel and a support. We demonstrated printing of heterogeneous tissue models formed of hydrogel scaffolds using this approach, including the outer ear, kidney and tooth tissue. These results indicate that this approach is particularly promising for tissue engineering and 3D printing applications to regenerate heterogeneous organs and tissues with tailored geometries to treat specific defects or injuries.

  2. Identification and classification in le fort type fractures by using 2D and 3D computed tomography

    Institute of Scientific and Technical Information of China (English)

    CHEN We-jian; YANG Yun-jun; FANG Yi-ming; XU Fang-hong; ZHANG Lin; CAO Guo-quan

    2006-01-01

    Objective:To evaluate the usefulness of twodimensional (2D) and three-dimensional (3D) computed tomography (CT) in the identification and classification of Le Fort type fractures.Methods: Sixty-two patients with different types of Le Fort fractures underwent CT scanning and 3D-CT reconstruction. The data were analyzed by multiplanar reconstruction (MPR), surface shaded display (SSD) and volume rendering (VR) respectively.Results: The patients with Le Fort Ⅰ , Le Fort Ⅱfracture and Le Fort Ⅲ fracture accounted for 16.1%,14.5 % and 12.9 % respectively. The compound fractures were the most common type and accounted for 56.5 % ( n =35, 18 cases with Le Fort Ⅰ + Ⅱ fracture, 10 cases with Le Fort Ⅱ + Ⅲ fracture and 7 cases with Le Fort Ⅰ + Ⅱ + Ⅲfracture). Fifty-five cases coexisted with other fractures in maxillofacial region. 2D-CT could be used to define the tiny fractures and the deep-structure fractures more accurately compared with 3D-CT, but the real impression of Le Fort type fractures could not be correctly evaluated on 2D-CT.3D-CT could clearly demonstrate the whole shape of Le Fort type fractures and identify the classification of Le Fort fractures.Conclusions: 3D-CT is the best imaging method for the diagnosis of Le Fort type fractures and can provide valuable information of space relationship, especially for the design of treatment plan before operation.

  3. Use of micro computed-tomography and 3D printing for reverse engineering of mouse embryo nasal capsule

    Science.gov (United States)

    Tesařová, M.; Zikmund, T.; Kaucká, M.; Adameyko, I.; Jaroš, J.; Paloušek, D.; Škaroupka, D.; Kaiser, J.

    2016-03-01

    Imaging of increasingly complex cartilage in vertebrate embryos is one of the key tasks of developmental biology. This is especially important to study shape-organizing processes during initial skeletal formation and growth. Advanced imaging techniques that are reflecting biological needs give a powerful impulse to push the boundaries of biological visualization. Recently, techniques for contrasting tissues and organs have improved considerably, extending traditional 2D imaging approaches to 3D . X-ray micro computed tomography (μCT), which allows 3D imaging of biological objects including their internal structures with a resolution in the micrometer range, in combination with contrasting techniques seems to be the most suitable approach for non-destructive imaging of embryonic developing cartilage. Despite there are many software-based ways for visualization of 3D data sets, having a real solid model of the studied object might give novel opportunities to fully understand the shape-organizing processes in the developing body. In this feasibility study we demonstrated the full procedure of creating a real 3D object of mouse embryo nasal capsule, i.e. the staining, the μCT scanning combined by the advanced data processing and the 3D printing.

  4. Application of multi-resolution 3D techniques in crime scene documentation with bloodstain pattern analysis.

    Science.gov (United States)

    Hołowko, Elwira; Januszkiewicz, Kamil; Bolewicki, Paweł; Sitnik, Robert; Michoński, Jakub

    2016-10-01

    In forensic documentation with bloodstain pattern analysis (BPA) it is highly desirable to obtain non-invasively overall documentation of a crime scene, but also register in high resolution single evidence objects, like bloodstains. In this study, we propose a hierarchical 3D scanning platform designed according to the top-down approach known from the traditional forensic photography. The overall 3D model of a scene is obtained via integration of laser scans registered from different positions. Some parts of a scene being particularly interesting are documented using midrange scanner, and the smallest details are added in the highest resolution as close-up scans. The scanning devices are controlled using developed software equipped with advanced algorithms for point cloud processing. To verify the feasibility and effectiveness of multi-resolution 3D scanning in crime scene documentation, our platform was applied to document a murder scene simulated by the BPA experts from the Central Forensic Laboratory of the Police R&D, Warsaw, Poland. Applying the 3D scanning platform proved beneficial in the documentation of a crime scene combined with BPA. The multi-resolution 3D model enables virtual exploration of a scene in a three-dimensional environment, distance measurement, and gives a more realistic preservation of the evidences together with their surroundings. Moreover, high-resolution close-up scans aligned in a 3D model can be used to analyze bloodstains revealed at the crime scene. The result of BPA such as trajectories, and the area of origin are visualized and analyzed in an accurate model of a scene. At this stage, a simplified approach considering the trajectory of blood drop as a straight line is applied. Although the 3D scanning platform offers a new quality of crime scene documentation with BPA, some of the limitations of the technique are also mentioned.

  5. A Real-Time Magnetoencephalography Brain-Computer Interface Using Interactive 3D Visualization and the Hadoop Ecosystem

    Science.gov (United States)

    McClay, Wilbert A.; Yadav, Nancy; Ozbek, Yusuf; Haas, Andy; Attias, Hagaii T.; Nagarajan, Srikantan S.

    2015-01-01

    Ecumenically, the fastest growing segment of Big Data is human biology-related data and the annual data creation is on the order of zetabytes. The implications are global across industries, of which the treatment of brain related illnesses and trauma could see the most significant and immediate effects. The next generation of health care IT and sensory devices are acquiring and storing massive amounts of patient related data. An innovative Brain-Computer Interface (BCI) for interactive 3D visualization is presented utilizing the Hadoop Ecosystem for data analysis and storage. The BCI is an implementation of Bayesian factor analysis algorithms that can distinguish distinct thought actions using magneto encephalographic (MEG) brain signals. We have collected data on five subjects yielding 90% positive performance in MEG mid- and post-movement activity. We describe a driver that substitutes the actions of the BCI as mouse button presses for real-time use in visual simulations. This process has been added into a flight visualization demonstration. By thinking left or right, the user experiences the aircraft turning in the chosen direction. The driver components of the BCI can be compiled into any software and substitute a user’s intent for specific keyboard strikes or mouse button presses. The BCI’s data analytics of a subject’s MEG brainwaves and flight visualization performance are stored and analyzed using the Hadoop Ecosystem as a quick retrieval data warehouse. PMID:26437432

  6. A Real-Time Magnetoencephalography Brain-Computer Interface Using Interactive 3D Visualization and the Hadoop Ecosystem.

    Science.gov (United States)

    McClay, Wilbert A; Yadav, Nancy; Ozbek, Yusuf; Haas, Andy; Attias, Hagaii T; Nagarajan, Srikantan S

    2015-09-30

    Ecumenically, the fastest growing segment of Big Data is human biology-related data and the annual data creation is on the order of zetabytes. The implications are global across industries, of which the treatment of brain related illnesses and trauma could see the most significant and immediate effects. The next generation of health care IT and sensory devices are acquiring and storing massive amounts of patient related data. An innovative Brain-Computer Interface (BCI) for interactive 3D visualization is presented utilizing the Hadoop Ecosystem for data analysis and storage. The BCI is an implementation of Bayesian factor analysis algorithms that can distinguish distinct thought actions using magneto encephalographic (MEG) brain signals. We have collected data on five subjects yielding 90% positive performance in MEG mid- and post-movement activity. We describe a driver that substitutes the actions of the BCI as mouse button presses for real-time use in visual simulations. This process has been added into a flight visualization demonstration. By thinking left or right, the user experiences the aircraft turning in the chosen direction. The driver components of the BCI can be compiled into any software and substitute a user's intent for specific keyboard strikes or mouse button presses. The BCI's data analytics OPEN ACCESS Brain. Sci. 2015, 5 420 of a subject's MEG brainwaves and flight visualization performance are stored and analyzed using the Hadoop Ecosystem as a quick retrieval data warehouse.

  7. A Real-Time Magnetoencephalography Brain-Computer Interface Using Interactive 3D Visualization and the Hadoop Ecosystem

    Directory of Open Access Journals (Sweden)

    Wilbert A. McClay

    2015-09-01

    Full Text Available Ecumenically, the fastest growing segment of Big Data is human biology-related data and the annual data creation is on the order of zetabytes. The implications are global across industries, of which the treatment of brain related illnesses and trauma could see the most significant and immediate effects. The next generation of health care IT and sensory devices are acquiring and storing massive amounts of patient related data. An innovative Brain-Computer Interface (BCI for interactive 3D visualization is presented utilizing the Hadoop Ecosystem for data analysis and storage. The BCI is an implementation of Bayesian factor analysis algorithms that can distinguish distinct thought actions using magneto encephalographic (MEG brain signals. We have collected data on five subjects yielding 90% positive performance in MEG mid- and post-movement activity. We describe a driver that substitutes the actions of the BCI as mouse button presses for real-time use in visual simulations. This process has been added into a flight visualization demonstration. By thinking left or right, the user experiences the aircraft turning in the chosen direction. The driver components of the BCI can be compiled into any software and substitute a user’s intent for specific keyboard strikes or mouse button presses. The BCI’s data analytics OPEN ACCESS Brain. Sci. 2015, 5 420 of a subject’s MEG brainwaves and flight visualization performance are stored and analyzed using the Hadoop Ecosystem as a quick retrieval data warehouse.

  8. Seepage-Based Factor of Safety Analysis Using 3D Groundwater Simulation Results

    Science.gov (United States)

    2014-08-01

    Hydraulics Engineering Technical Note (CHETN) is to document techniques for computing Factors of Safety (FoS) for seepage-related soil instability...topography, geology, sources or sinks , and boundary conditions along the length of the soil structure. If these conditions exist, a 3D model may be needed... hydraulic gradient, and iv is the exit gradient at the point of interest. The critical, stable, and unstable conditions are thus defined as FoS = 1, FoS

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

    Directory of Open Access Journals (Sweden)

    Kyoungah Choi

    2015-09-01

    Full Text Available 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.

  10. Development of 3D Chromatin Texture Analysis Using Confocal Laser Scanning Microscopy

    Directory of Open Access Journals (Sweden)

    André Huisman

    2005-01-01

    Full Text Available Introduction: Analysis of nuclear texture features as a measure of nuclear chromatin changes has been proven to be useful when measured on thin (5–6 μm tissue sections using conventional 2D bright field microscopy. The drawback of this approach is that most nuclei are not intact because of those thin sections. Confocal laser scanning microscopy (CLSM allows measurements of texture in 3D reconstructed nuclei. The aim of this study was to develop 3D texture features that quantitatively describe changes in chromatin architecture associated with malignancy using CLSM images. Methods: Thirty-five features thoughtfully chosen from 4 categories of 3D texture features (discrete texture features, Markovian features, fractal features, grey value distribution features were selected and tested for invariance properties (rotation and scaling using artificial images with a known grey value distribution. The discriminative power of the 3D texture features was tested on artificially constructed benign and malignant 3D nuclei with increasing nucleolar size and advancing chromatin margination towards the periphery of the nucleus. As a clinical proof of principle, the discriminative power of the texture features was assessed on 10 benign and 10 malignant human prostate nuclei, evaluating also whether there was more texture information in 3D whole nuclei compared to a single 2D plane from the middle of the nucleus. Results: All texture features showed the expected invariance properties. Almost all features were sensitive to variations in the nucleolar size and to the degree of margination of chromatin. Fourteen texture features from different categories had high discriminative power for separating the benign and malignant nuclei. The discrete texture features performed less than expected. There was more information on nuclear texture in 3D than in 2D. Conclusion: A set of 35 3D nuclear texture features was used successfully to assess nuclear chromatin patterns

  11. A Pipeline for 3D Multimodality Image Integration and Computer-assisted Planning in Epilepsy Surgery.

    Science.gov (United States)

    Nowell, Mark; Rodionov, Roman; Zombori, Gergely; Sparks, Rachel; Rizzi, Michele; Ourselin, Sebastien; Miserocchi, Anna; McEvoy, Andrew; Duncan, John

    2016-01-01

    Epilepsy surgery is challenging and the use of 3D multimodality image integration (3DMMI) to aid presurgical planning is well-established. Multimodality image integration can be technically demanding, and is underutilised in clinical practice. We have developed a single software platform for image integration, 3D visualization and surgical planning. Here, our pipeline is described in step-by-step fashion, starting with image acquisition, proceeding through image co-registration, manual segmentation, brain and vessel extraction, 3D visualization and manual planning of stereoEEG (SEEG) implantations. With dissemination of the software this pipeline can be reproduced in other centres, allowing other groups to benefit from 3DMMI. We also describe the use of an automated, multi-trajectory planner to generate stereoEEG implantation plans. Preliminary studies suggest this is a rapid, safe and efficacious adjunct for planning SEEG implantations. Finally, a simple solution for the export of plans and models to commercial neuronavigation systems for implementation of plans in the operating theater is described. This software is a valuable tool that can support clinical decision making throughout the epilepsy surgery pathway.

  12. 3D finite elements method (FEM Analysis of basic process parameters in rotary piercing mill

    Directory of Open Access Journals (Sweden)

    Z. Pater

    2012-10-01

    Full Text Available In this paper 3D FEM analysis of process parameters and its infl uence in rotary piercing mill is presented. The FEM analyze of the rotary piercing process was made under the conditions of 3D state of strain with taking into consideration the thermal phenomena. The calculations were made with application of different rolls’ skew angles and different plug designs. In the result, progression of shapes, temperature and distributions of stress and strain were characterized. The numerical results of calculations were compared with results of stand test with use of 100Cr6 steel. The comparisons of numerical and experimental tests confirm good agreement between obtained results.

  13. Open Plot Project: an open-source toolkit for 3-D structural data analysis

    Directory of Open Access Journals (Sweden)

    S. Tavani

    2011-05-01

    Full Text Available In this work we present the Open Plot Project, an open-source software for structural data analysis, including a 3-D environment. The software includes many classical functionalities of structural data analysis tools, like stereoplot, contouring, tensorial regression, scatterplots, histograms and transect analysis. In addition, efficient filtering tools are present allowing the selection of data according to their attributes, including spatial distribution and orientation. This first alpha release represents a stand-alone toolkit for structural data analysis.

    The presence of a 3-D environment with digitalising tools allows the integration of structural data with information extracted from georeferenced images to produce structurally validated dip domains. This, coupled with many import/export facilities, allows easy incorporation of structural analyses in workflows for 3-D geological modelling. Accordingly, Open Plot Project also candidates as a structural add-on for 3-D geological modelling software.

    The software (for both Windows and Linux O.S., the User Manual, a set of example movies (complementary to the User Manual, and the source code are provided as Supplement. We intend the publication of the source code to set the foundation for free, public software that, hopefully, the structural geologists' community will use, modify, and implement. The creation of additional public controls/tools is strongly encouraged.

  14. New technologies of 2-D and 3-D modeling for analysis and management of natural resources

    Science.gov (United States)

    Cheremisina, E. N.; Lyubimova, A. V.; Kirpicheva, E. Yu.

    2016-09-01

    For ensuring technological support of research and administrative activity in the sphere of environmental management a specialized modular program complex was developed. The special attention in developing a program complex is focused to creation of convenient and effective tools for creation and visualization 2d and 3D models providing the solution of tasks of the analysis and management of natural resources.

  15. Recent developments in computer-generated holography: toward a practical electroholography system for interactive 3D visualization

    Science.gov (United States)

    Slinger, Christopher W.; Cameron, Colin D.; Coomber, Stuart D.; Miller, Richard J.; Payne, Doug A.; Smith, Allan P.; Smith, Mark G.; Stanley, Maurice; Watson, Philip J.

    2004-06-01

    This paper will give an overview of some recent developments in electroholography for applications in interactive 3D visualisation. Arguably the ultimate technology for this task, it is the only approach having the potential to deliver full depth cue, 3D images, having resolutions beyond that which can be perceived by the human eye. Despite significant advances by many researchers, the high pixel counts required by the computer generated hologram (CGH) patterns in these systems remain daunting - in practice, systems able to calculate and display reconfigurable CGH having pixel counts of more than one billion may be required for 300 mm width, 3D images. Advances described include novel Fourier mode variants of diffraction specific algorithms and parallel binarisation techniques for design of the CGH patterns; computer architectures for effective implementation of these algorithms for interactive CGH calculation; the latest developments in the Active Tiling spatial light modulator technology and novel replay optics arrangements including folded mirror geometries, viewer tracking alternatives and new horizontal parallax configurations. Throughout, the emphasis is optimisation towards implementation as an interactive electroholography system having practical utility. Some recent results from demonstrations of aspects of the technology will be shown. These include monochrome and colour, static and dynamic, horizontal parallax only (HPO) and full parallax, 3D images, generated from true CGH systems with up to 24 billion pixels.

  16. Finite element analysis of 3D elastic-plastic frictional contact problem for Cosserat materials

    Science.gov (United States)

    Zhang, S.; Xie, Z. Q.; Chen, B. S.; Zhang, H. W.

    2013-06-01

    The objective of this paper is to develop a finite element model for 3D elastic-plastic frictional contact problem of Cosserat materials. Because 3D elastic-plastic frictional contact problems belong to the unspecified boundary problems with nonlinearities in both material and geometric forms, a large number of calculations are needed to obtain numerical results with high accuracy. Based on the parametric variational principle and the corresponding quadratic programming method for numerical simulation of frictional contact problems, a finite element model is developed for 3D elastic-plastic frictional contact analysis of Cosserat materials. The problems are finally reduced to linear complementarity problems (LCP). Numerical examples show the feasibility and importance of the developed model for analyzing the contact problems of structures with materials which have micro-polar characteristics.

  17. A 3-D model of superfluid helium suitable for numerical analysis

    CERN Document Server

    Darve, C; Van Sciver, S W

    2009-01-01

    The two-fluid description is a very successful phenomenological representation of the properties of Helium II. A 3-D model suitable for numerical analysis based on the Landau-Khalatnikov description of Helium II is proposed. In this paper we introduce a system of partial differential equations that is both complete and consistent as well as practical, to be used for a 3-D solution of the flow of Helium II. The development of a 3-D numerical model for Helium II is motivated by the need to validate experimental results obtained by observing the normal component velocity distribution in a Helium II thermal counter-flow using the Particle Image Velocimetry (PIV) technique.

  18. On a 3-D singularity element for computation of combined mode stress intensities

    Science.gov (United States)

    Atluri, S. N.; Kathiresan, K.

    1976-01-01

    A special three-dimensional singularity element is developed for the computation of combined modes 1, 2, and 3 stress intensity factors, which vary along an arbitrarily curved crack front in three dimensional linear elastic fracture problems. The finite element method is based on a displacement-hybrid finite element model, based on a modified variational principle of potential energy, with arbitrary element interior displacements, interelement boundary displacements, and element boundary tractions as variables. The special crack-front element used in this analysis contains the square root singularity in strains and stresses, where the stress-intensity factors K(1), K(2), and K(3) are quadratically variable along the crack front and are solved directly along with the unknown nodal displacements.

  19. Users manual for CAFE-3D : a computational fluid dynamics fire code.

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, Imane; Lopez, Carlos; Suo-Anttila, Ahti Jorma (Alion Science and Technology, Albuquerque, NM)

    2005-03-01

    The Container Analysis Fire Environment (CAFE) computer code has been developed to model all relevant fire physics for predicting the thermal response of massive objects engulfed in large fires. It provides realistic fire thermal boundary conditions for use in design of radioactive material packages and in risk-based transportation studies. The CAFE code can be coupled to commercial finite-element codes such as MSC PATRAN/THERMAL and ANSYS. This coupled system of codes can be used to determine the internal thermal response of finite element models of packages to a range of fire environments. This document is a user manual describing how to use the three-dimensional version of CAFE, as well as a description of CAFE input and output parameters. Since this is a user manual, only a brief theoretical description of the equations and physical models is included.

  20. 2D fluid model analysis for the effect of 3D gas flow on a capacitively coupled plasma deposition reactor

    Science.gov (United States)

    Kim, Ho Jun; Lee, Hae June

    2016-06-01

    The wide applicability of capacitively coupled plasma (CCP) deposition has increased the interest in developing comprehensive numerical models, but CCP imposes a tremendous computational cost when conducting a transient analysis in a three-dimensional (3D) model which reflects the real geometry of reactors. In particular, the detailed flow features of reactive gases induced by 3D geometric effects need to be considered for the precise calculation of radical distribution of reactive species. Thus, an alternative inclusive method for the numerical simulation of CCP deposition is proposed to simulate a two-dimensional (2D) CCP model based on the 3D gas flow results by simulating flow, temperature, and species fields in a 3D space at first without calculating the plasma chemistry. A numerical study of a cylindrical showerhead-electrode CCP reactor was conducted for particular cases of SiH4/NH3/N2/He gas mixture to deposit a hydrogenated silicon nitride (SiN x H y ) film. The proposed methodology produces numerical results for a 300 mm wafer deposition reactor which agree very well with the deposition rate profile measured experimentally along the wafer radius.

  1. Computation of thermal properties via 3D homogenization of multiphase materials using FFT-based accelerated scheme

    CERN Document Server

    Lemaitre, Sophie; Choi, Daniel; Karamian, Philippe

    2015-01-01

    In this paper we study the thermal effective behaviour for 3D multiphase composite material consisting of three isotropic phases which are the matrix, the inclusions and the coating media. For this purpose we use an accelerated FFT-based scheme initially proposed in Eyre and Milton (1999) to evaluate the thermal conductivity tensor. Matrix and spherical inclusions media are polymers with similar properties whereas the coating medium is metallic hence better conducting. Thus, the contrast between the coating and the others media is very large. For our study, we use RVEs (Representative volume elements) generated by RSA (Random Sequential Adsorption) method developed in our previous works, then, we compute effective thermal properties using an FFT-based homogenization technique validated by comparison with the direct finite elements method. We study the thermal behaviour of the 3D-multiphase composite material and we show what features should be taken into account to make the computational approach efficient.

  2. PROP3D: A Program for 3D Euler Unsteady Aerodynamic and Aeroelastic (Flutter and Forced Response) Analysis of Propellers. Version 1.0

    Science.gov (United States)

    Srivastava, R.; Reddy, T. S. R.

    1996-01-01

    This guide describes the input data required, for steady or unsteady aerodynamic and aeroelastic analysis of propellers and the output files generated, in using PROP3D. The aerodynamic forces are obtained by solving three dimensional unsteady, compressible Euler equations. A normal mode structural analysis is used to obtain the aeroelastic equations, which are solved using either time domain or frequency domain solution method. Sample input and output files are included in this guide for steady aerodynamic analysis of single and counter-rotation propellers, and aeroelastic analysis of single-rotation propeller.

  3. Implementation of Headtracking and 3D Stereo with Unity and VRPN for Computer Simulations

    Science.gov (United States)

    Noyes, Matthew A.

    2013-01-01

    This paper explores low-cost hardware and software methods to provide depth cues traditionally absent in monocular displays. The use of a VRPN server in conjunction with a Microsoft Kinect and/or Nintendo Wiimote to provide head tracking information to a Unity application, and NVIDIA 3D Vision for retinal disparity support, is discussed. Methods are suggested to implement this technology with NASA's EDGE simulation graphics package, along with potential caveats. Finally, future applications of this technology to astronaut crew training, particularly when combined with an omnidirectional treadmill for virtual locomotion and NASA's ARGOS system for reduced gravity simulation, are discussed.

  4. 3D game engine design a practical approach to real-time computer graphics

    CERN Document Server

    Eberly, David H

    2006-01-01

    A major revision of the international bestseller on game programming!Graphics hardware has evolved enormously in the last decade. Hardware can now be directly controlled through techniques such as shader programming, which requires an entirely new thought process of a programmer. 3D Game Engine Design, Second Edition shows step-by-step how to make a shader-based graphics engine and how to tame the new technology. Much new material has been added, including more than twice the coverage of the essential techniques of scene graph management, as well as new methods for manag

  5. 3-D gravity analysis of the Dniepr Donets Basin and Donbas Foldbelt, Ukraine

    Science.gov (United States)

    Yegorova, T. P.; Stephenson, R. A.; Kozlenko, V. G.; Starostenko, V. I.; Legostaeva, O. V.

    1999-11-01

    The Dniepr-Donets Basin (DDB) is a linear, NW-SE trending, late Palaeozoic and younger sedimentary basin on the East European Platform separating the Ukrainian Shield from the Voronezh Massif. Its northwestern (Dniepr) segment has the characteristics of a typical rift basin. To the southeast, through a transition zone of approximately 200 km length, the DDB is progressively uplifted and compressionally deformed into the correlatable Donbas Foldbelt (DF). Along the axis of the Dniepr segment a series of gravity highs has been previously explained by high-density crystalline crust beneath the axis of the basin caused by intrusion of mafic and ultramafic rocks. In this paper, the results of a 3-D gravity analysis, using a gravity backstripping technique, is described that investigates the crustal and upper mantle structure in the region of the DDB-DF transition zone and DF. A residual gravity field I, obtained by subtracting the gravity influence of the sedimentary succession of the DDB from the observed field, reveals a distinct positive anomaly along the axis of the rift basin increasing in amplitude to the southeast in concert with increasing sedimentary thickness. A residual gravity field II, derived by removing the gravity effects of a modelled homogeneous crystalline crust from residual field I, reaches 200 and 100 mGal amplitude in the DF for two respective Moho models based on different interpretations of the published crust and upper mantle seismic velocity models. The first of these (model A) assumes crustal thickening beneath the transition zone and DF (to a Moho depth up to 50 km) whereas the second (model B) assumes a Moho shallowing (to depths in the range 35-37 km) along the whole basin axis. For each residual anomaly II, the best-fitting 3-D distribution of average density in the crystalline crust has been computed. Both models indicate the existence of a high-density body in the crystalline crust along the DDB axis, increasing in density from the

  6. Quality Analysis on 3d Buidling Models Reconstructed from Uav Imagery

    Science.gov (United States)

    Jarzabek-Rychard, M.; Karpina, M.

    2016-06-01

    Recent developments in UAV technology and structure from motion techniques have effected that UAVs are becoming standard platforms for 3D data collection. Because of their flexibility and ability to reach inaccessible urban parts, drones appear as optimal solution for urban applications. Building reconstruction from the data collected with UAV has the important potential to reduce labour cost for fast update of already reconstructed 3D cities. However, especially for updating of existing scenes derived from different sensors (e.g. airborne laser scanning), a proper quality assessment is necessary. The objective of this paper is thus to evaluate the potential of UAV imagery as an information source for automatic 3D building modeling at LOD2. The investigation process is conducted threefold: (1) comparing generated SfM point cloud to ALS data; (2) computing internal consistency measures of the reconstruction process; (3) analysing the deviation of Check Points identified on building roofs and measured with a tacheometer. In order to gain deep insight in the modeling performance, various quality indicators are computed and analysed. The assessment performed according to the ground truth shows that the building models acquired with UAV-photogrammetry have the accuracy of less than 18 cm for the plannimetric position and about 15 cm for the height component.

  7. 3-D segmentation and quantitative analysis of inner and outer walls of thrombotic abdominal aortic aneurysms

    Science.gov (United States)

    Lee, Kyungmoo; Yin, Yin; Wahle, Andreas; Olszewski, Mark E.; Sonka, Milan

    2008-03-01

    An abdominal aortic aneurysm (AAA) is an area of a localized widening of the abdominal aorta, with a frequent presence of thrombus. A ruptured aneurysm can cause death due to severe internal bleeding. AAA thrombus segmentation and quantitative analysis are of paramount importance for diagnosis, risk assessment, and determination of treatment options. Until now, only a small number of methods for thrombus segmentation and analysis have been presented in the literature, either requiring substantial user interaction or exhibiting insufficient performance. We report a novel method offering minimal user interaction and high accuracy. Our thrombus segmentation method is composed of an initial automated luminal surface segmentation, followed by a cost function-based optimal segmentation of the inner and outer surfaces of the aortic wall. The approach utilizes the power and flexibility of the optimal triangle mesh-based 3-D graph search method, in which cost functions for thrombus inner and outer surfaces are based on gradient magnitudes. Sometimes local failures caused by image ambiguity occur, in which case several control points are used to guide the computer segmentation without the need to trace borders manually. Our method was tested in 9 MDCT image datasets (951 image slices). With the exception of a case in which the thrombus was highly eccentric, visually acceptable aortic lumen and thrombus segmentation results were achieved. No user interaction was used in 3 out of 8 datasets, and 7.80 +/- 2.71 mouse clicks per case / 0.083 +/- 0.035 mouse clicks per image slice were required in the remaining 5 datasets.

  8. The impacts of open-mouth breathing on upper airway space in obstructive sleep apnea: 3-D MDCT analysis.

    Science.gov (United States)

    Kim, Eun Joong; Choi, Ji Ho; Kim, Kang Woo; Kim, Tae Hoon; Lee, Sang Hag; Lee, Heung Man; Shin, Chol; Lee, Ki Yeol; Lee, Seung Hoon

    2011-04-01

    Open-mouth breathing during sleep is a risk factor for obstructive sleep apnea (OSA) and is associated with increased disease severity and upper airway collapsibility. The aim of this study was to investigate the effect of open-mouth breathing on the upper airway space in patients with OSA using three-dimensional multi-detector computed tomography (3-D MDCT). The study design included a case-control study with planned data collection. The study was performed at a tertiary medical center. 3-D MDCT analysis was conducted on 52 patients with OSA under two experimental conditions: mouth closed and mouth open. Under these conditions, we measured the minimal cross-sectional area of the retropalatal and retroglossal regions (mXSA-RP, mXSA-RG), as well as the upper airway length (UAL), defined as the vertical dimension from hard palate to hyoid. We also computed the volume of the upper airway space by 3-D reconstruction of both conditions. When the mouth was open, mXSA-RP and mXSA-RG significantly decreased and the UAL significantly increased, irrespective of the severity of OSA. However, between the closed- and open-mouth states, there was no significant change in upper airway volume at any severity of OSA. Results suggest that the more elongated and narrow upper airway during open-mouth breathing may aggravate the collapsibility of the upper airway and, thus, negatively affect OSA severity.

  9. Multivoxel pattern analysis reveals 3D place information in the human hippocampus.

    Science.gov (United States)

    Kim, Misun; Jeffery, Kate J; Maguire, Eleanor A

    2017-03-20

    The spatial world is three-dimensional (3D), and humans and other animals move both horizontally and vertically within it. Extant neuroscientific studies have typically investigated spatial navigation on a horizontal two-dimensional plane, leaving much unknown about how 3D spatial information is represented in the brain. Specifically, horizontal and vertical information may be encoded in the same or different neural structures with equal or unequal sensitivity. Here, we investigated these possibilities using functional MRI (fMRI) while participants were passively moved within a 3D lattice structure as if riding a rollercoaster. Multivoxel pattern analysis was used to test for the existence of information relating to where and in which direction participants were heading in this virtual environment. Behaviorally, participants had similarly accurate memory for vertical and horizontal locations, and the right anterior hippocampus expressed place information that was sensitive to changes along both horizontal and vertical axes. This is suggestive of isotropic 3D place encoding. By contrast, participants indicated their heading direction faster and more accurately when they were heading in a tilted-up or tilted-down direction. This direction information was expressed in the right retrosplenial cortex and posterior hippocampus, and was only sensitive to vertical pitch, which could reflect the importance of the vertical (gravity) axis as a reference frame. Overall, our findings extend previous knowledge of how we represent the spatial world and navigate within it, by taking into account the important third dimension.SIGNIFICANCE STATEMENTThe spatial world is three-dimensional (3D) -- we can move horizontally across surfaces, but also vertically, going up slopes or stairs. Little is known about how the brain supports representations of 3D space. A key question is whether or not horizontal and vertical information is equally well represented. Here we measured functional MRI

  10. Micro-computed tomography image-based evaluation of 3D anisotropy degree of polymer scaffolds.

    Science.gov (United States)

    Pérez-Ramírez, Ursula; López-Orive, Jesús Javier; Arana, Estanislao; Salmerón-Sánchez, Manuel; Moratal, David

    2015-01-01

    Anisotropy is one of the most meaningful determinants of biomechanical behaviour. This study employs micro-computed tomography (μCT) and image techniques for analysing the anisotropy of regenerative medicine polymer scaffolds. For this purpose, three three-dimensional anisotropy evaluation image methods were used: ellipsoid of inertia (EI), mean intercept length (MIL) and tensor scale (t-scale). These were applied to three patterns (a sphere, a cube and a right prism) and to two polymer scaffold topologies (cylindrical orthogonal pore mesh and spherical pores). For the patterns, the three methods provided good results. Regarding the scaffolds, EI mistook both topologies (0.0158, [-0.5683; 0.6001]; mean difference and 95% confidence interval), and MIL showed no significant differences (0.3509, [0.0656; 0.6362]). T-scale is the preferable method because it gave the best capability (0.3441, [0.1779; 0.5102]) to differentiate both topologies. This methodology results in the development of non-destructive tools to engineer biomimetic scaffolds, incorporating anisotropy as a fundamental property to be mimicked from the original tissue and permitting its assessment by means of μCT image analysis.

  11. 3-D computational method of wave loads on turret moored FPSO tankers

    Institute of Scientific and Technical Information of China (English)

    REN Hui-long; ZHANG Hai-bin; DAI Yu-zhi; SONG Jing-zheng

    2003-01-01

    A three-dimensional method of calculating wave loads of turret moored FPSO (Floating Production Storage and Offloading) tankers is presented. The linearized restoring forces acting on the ship hull by the mooring system are calculated according to the catenary theory, which are expressed as the function of linear stiffness coefficients and the displacements of the upper ends of mooring chains. The hydrodynamic coefficients of the ship are calculated by the three-dimensional potential flow theory of the linear hydrodynamic problem for ships with a low forward speed. The equations of ship motions are established with the effect of the restoring forces from the mooring system included as linear stiffness coefficients. The equations of motions are solved in frequency domain, and the responses of wave-induced motions and loads on the ship can be obtained. A computer program based on this method has been developed,and some calculation examples are illustrated. Analysis results show that the method can give satisfying prediction of wave loads.

  12. Leveraging performance of 3D finite difference schemes in large scientific computing simulations

    OpenAIRE

    De la Cruz, Raúl

    2015-01-01

    Gone are the days when engineers and scientists conducted most of their experiments empirically. During these decades, actual tests were carried out in order to assess the robustness and reliability of forthcoming product designs and prove theoretical models. With the advent of the computational era, scientific computing has definetely become a feasible solution compared with empirical methods, in terms of effort, cost and reliability. Large and massively parallel computational resources have...

  13. Casting directly from a computer model by using advanced simulation software FLOW-3D Cast ®

    Directory of Open Access Journals (Sweden)

    M. Sirviö

    2009-01-01

    Full Text Available ConiferRob - A patternless casting technique, originally conceived at VTT Technical Research Centre of Finland and furtherdeveloped at its spin-off company, Simtech Systems, offers up to 40% savings in product development costs, and up to two months shorterdevelopment times compared to conventional techniques. Savings of this order can be very valuable on today's highly competitivemarkets. Casting simulation is commonly used for designing of casting systems. However, most of the software are today old fashioned and predicting just shrinkage porosity. Flow Science, VTT and Simtech have developed new software called FLOW-3D Cast ® , whichcan simulate surface defects, air entrainment, filters, core gas problems and even a cavitation.

  14. A novel structured dictionary for fast processing of 3D medical images, with application to computed tomography restoration and denoising

    Science.gov (United States)

    Karimi, Davood; Ward, Rabab K.

    2016-03-01

    Sparse representation of signals in learned overcomplete dictionaries has proven to be a powerful tool with applications in denoising, restoration, compression, reconstruction, and more. Recent research has shown that learned overcomplete dictionaries can lead to better results than analytical dictionaries such as wavelets in almost all image processing applications. However, a major disadvantage of these dictionaries is that their learning and usage is very computationally intensive. In particular, finding the sparse representation of a signal in these dictionaries requires solving an optimization problem that leads to very long computational times, especially in 3D image processing. Moreover, the sparse representation found by greedy algorithms is usually sub-optimal. In this paper, we propose a novel two-level dictionary structure that improves the performance and the speed of standard greedy sparse coding methods. The first (i.e., the top) level in our dictionary is a fixed orthonormal basis, whereas the second level includes the atoms that are learned from the training data. We explain how such a dictionary can be learned from the training data and how the sparse representation of a new signal in this dictionary can be computed. As an application, we use the proposed dictionary structure for removing the noise and artifacts in 3D computed tomography (CT) images. Our experiments with real CT images show that the proposed method achieves results that are comparable with standard dictionary-based methods while substantially reducing the computational time.

  15. A cubic interpolation pipeline for fast computation of 3D deformation fields modeled using B-splines

    Science.gov (United States)

    Castro-Pareja, Carlos R.; Shekhar, Raj

    2006-02-01

    Fast computation of 3D deformation fields is critical to bringing the application of automated elastic image registration algorithms to routine clinical practice. However, it lies beyond the computational power of current microprocessors; therefore requiring implementations using either massively parallel computers or application-specific hardware accelerators. The use of massively parallel computers in a clinical setting is not practical or cost-effective, therefore making the use of hardware accelerators necessary. We present a hardware pipeline that allows accelerating the computation of 3D deformation fields to speeds up to two orders of magnitude faster than software implementations on current workstations and about 64 times faster than other previously reported architectures. The pipeline implements a version of the free-form deformation calculation algorithm, which is optimized to minimize the number of arithmetic operations required to calculate the transformation of a given set of neighboring voxels, thereby achieving an efficient and compact implementation in hardware which allows its use as part of a larger system.

  16. Multi-dimensional Seismic Response Analysis of Base-Isolated Frame Structure with 3D Isolator

    Institute of Scientific and Technical Information of China (English)

    Xiong Shishu; Huang Liting; Chen Jinfeng; Su Jingsu

    2005-01-01

    The three-dimensional lead-rubber dish-spring bearing (3DB) is proposed in this paper. The 3DB is composed of lead rubber bearing (LRB) and dish-spring bearing (DSB) with damper in series. The 3DB put forward in this paper is effective in the resolution of difficulties in strong vertical capacity and vertical damping of three-dimensional isolation bearings. It effectively suppresses rocking motions as well. The analytical model and motion equations of multi-dimensional seismic responses of 3D base-isolated frame structures are established. Taking a five-storey frame structure as an example, an extensive simulation analysis is carried out. The results show that the 3D base-isolated structure with the proposed 3DB is effective in 3D isolation; it can reduce seismic responses by 50 % compared to a non-isolated structure. Therefore, the 3D isolation problem in building can be solved easily and effectively with the 3DB proposed in this paper.

  17. Integrated 3D-printed reactionware for chemical synthesis and analysis

    Science.gov (United States)

    Symes, Mark D.; Kitson, Philip J.; Yan, Jun; Richmond, Craig J.; Cooper, Geoffrey J. T.; Bowman, Richard W.; Vilbrandt, Turlif; Cronin, Leroy

    2012-05-01

    Three-dimensional (3D) printing has the potential to transform science and technology by creating bespoke, low-cost appliances that previously required dedicated facilities to make. An attractive, but unexplored, application is to use a 3D printer to initiate chemical reactions by printing the reagents directly into a 3D reactionware matrix, and so put reactionware design, construction and operation under digital control. Here, using a low-cost 3D printer and open-source design software we produced reactionware for organic and inorganic synthesis, which included printed-in catalysts and other architectures with printed-in components for electrochemical and spectroscopic analysis. This enabled reactions to be monitored in situ so that different reactionware architectures could be screened for their efficacy for a given process, with a digital feedback mechanism for device optimization. Furthermore, solely by modifying reactionware architecture, reaction outcomes can be altered. Taken together, this approach constitutes a relatively cheap, automated and reconfigurable chemical discovery platform that makes techniques from chemical engineering accessible to typical synthetic laboratories.

  18. 3D analysis of vortical structures in an abdominal aortic aneurysm by stereoscopic PIV

    Science.gov (United States)

    Deplano, Valérie; Guivier-Curien, Carine; Bertrand, Eric

    2016-11-01

    The present work presents an experimental in vitro three-dimensional analysis of the flow dynamics in an abdominal aortic aneurysm (AAA) through stereoscopic particle image velocimetry (SPIV) measurements. The experimental set-up mimics the pathophysiological context involving a shear thinning blood analogue fluid, compliant AAA and aorto-iliac bifurcation walls and controlled inlet and outlet flow rate and pressure waveforms as well as working fluid temperature. SPIV was carefully calibrated and conducted to assess the three velocity components in the AAA volume. For the first time in the literature, the 3D vortex ring genesis, propagation, and vanishing in the AAA bulge are experimentally described and quantified. In comparison with classical 2-component PIV measurements (2C PIV), the third component of the velocity vector was shown to be of importance in such a geometry, especially, during the deceleration phase of the flow rate. The 3D velocity magnitude reached up more than 20 % of the 2D one showing that 2C PIV are definitively not accurate enough to provide a complete description of flow behaviour in an AAA. In addition to potential clinical implications of a full 3D vortex ring description in AAA evolution, the 3D in vitro experimental quantification of the flow dynamics carried out in the present study offers an interesting tool for the validation of fluid-structure interaction numerical studies dealing with AAA.

  19. 3D DIGITIZATION OF AN HERITAGE MASTERPIECE - A CRITICAL ANALYSIS ON QUALITY ASSESSMENT

    Directory of Open Access Journals (Sweden)

    F. Menna

    2016-06-01

    Full Text Available Despite being perceived as interchangeable when properly applied, close-range photogrammetry and range imaging have both their pros and limitations that can be overcome using suitable procedures. Even if the two techniques have been frequently cross-compared, critical analysis discussing all sub-phases of a complex digitization project are quite rare. Comparisons taking into account the digitization of a cultural masterpiece, such as the Etruscan Sarcophagus of the Spouses (Figure 1 discussed in this paper, are even less common. The final 3D model of the Sarcophagus shows impressive spatial and texture resolution, in the order of tenths of millimetre for both digitization techniques, making it a large 3D digital model even though the physical size of the artwork is quite limited. The paper presents the survey of the Sarcophagus, a late 6th century BC Etruscan anthropoid Sarcophagus. Photogrammetry and laser scanning were used for its 3D digitization in two different times only few days apart from each other. The very short time available for the digitization was a crucial constraint for the surveying operations (due to constraints imposed us by the museum curators. Despite very high-resolution and detailed 3D models have been produced, a metric comparison between the two models shows intrinsic limitations of each technique that should be overcome through suitable onsite metric verification procedures as well as a proper processing workflow.

  20. Efficient computation of steady, 3D water-wave patterns, application to hovercraft-type flows

    NARCIS (Netherlands)

    Lewis, M.R.; Koren, B.

    2002-01-01

    Numerical methods for the computation of stationary free surfaces is the subject of much current research in computational engineering. The present report is directed towards free surfaces in maritime engineering. Of interest here are the long steady waves generated by hovercraft and ships, the grav

  1. Error Analysis of Terrestrial Laser Scanning Data by Means of Spherical Statistics and 3D Graphs

    Directory of Open Access Journals (Sweden)

    Pedro Arias

    2010-11-01

    Full Text Available This paper presents a complete analysis of the positional errors of terrestrial laser scanning (TLS data based on spherical statistics and 3D graphs. Spherical statistics are preferred because of the 3D vectorial nature of the spatial error. Error vectors have three metric elements (one module and two angles that were analyzed by spherical statistics. A study case has been presented and discussed in detail. Errors were calculating using 53 check points (CP and CP coordinates were measured by a digitizer with submillimetre accuracy. The positional accuracy was analyzed by both the conventional method (modular errors analysis and the proposed method (angular errors analysis by 3D graphics and numerical spherical statistics. Two packages in R programming language were performed to obtain graphics automatically. The results indicated that the proposed method is advantageous as it offers a more complete analysis of the positional accuracy, such as angular error component, uniformity of the vector distribution, error isotropy, and error, in addition the modular error component by linear statistics.

  2. Examining the effect of pore size distribution and shape on flow through unsaturated peat using 3-D computed tomography

    Directory of Open Access Journals (Sweden)

    F. Rezanezhad

    2009-05-01

    Full Text Available The hydraulic conductivity of unsaturated peat soils is controlled by the peat structure which affects the air-filled porosity, pore size distribution and shape. This study investigates how the size and shape of pores affects the flow of water through peat soils. In this study we used X-ray Computed Tomography (CT, at 45 µm resolution under 5 specific soil-water pressure head levels to provide 3-D, high-resolution images that were used to detect the inner pore structure of peat samples under a changing water regime. Pore structure and configuration were found to be irregular, which affected the rate of water transmission through peat soils. The 3-D analysis suggested that pore distribution is dominated by a single large pore-space. At low pressure head, this single large air-filled pore imparted a more effective flowpath compared to smaller pores. Smaller pores were disconnected and the flowpath was more tortuous than in the single large air-filled pore, and their contribution to flow was negligible when the single large pore was active. We quantify the pore structure of peat soil that affects the hydraulic conductivity in the unsaturated condition, and demonstrate the validity of our estimation of peat unsaturated hydraulic conductivity by making a comparison with a standard permeameter-based method. Estimates of unsaturated hydraulic conductivities were made for the purpose of testing the sensitivity of pore shape and geometry parameters on the hydraulic properties of peats and how to evaluate the structure of the peat and its affects on parameterization. We also studied the ability to quantify these factors for different soil moisture contents in order to define how the factors controlling the shape coefficient vary with changes in soil water pressure head. The relation between measured and estimated unsaturated hydraulic conductivity at various heads shows that rapid initial drainage, that changes the air-filled pore properties, creates a

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

    Energy Technology Data Exchange (ETDEWEB)

    Sofronov, I.D.; Voronin, B.L.; Butnev, O.I. [VNIIEF (Russian Federation)] [and others

    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.

  4. Defining new dental phenotypes using 3-D image analysis to enhance discrimination and insights into biological processes

    Science.gov (United States)

    Smith, Richard; Zaitoun, Halla; Coxon, Tom; Karmo, Mayada; Kaur, Gurpreet; Townsend, Grant; Harris, Edward F.; Brook, Alan

    2009-01-01

    Aims In studying aetiological interactions of genetic, epigenetic and environmental factors in normal and abnormal developments of the dentition, methods of measurement have often been limited to maximum mesio-distal and bucco-lingual crown diameters, obtained with hand-held calipers. While this approach has led to many important findings, there are potentially many other informative measurements that can be made to describe dental crown morphology. Advances in digital imaging and computer technology now offer the opportunity to define and measure new dental phenotypes in 3-D that have the potential to provide better anatomical discrimination and clearer insights into the underlying biological processes in dental development. Over recent years, image analysis in 2-D has proved to be a valuable addition to hand-measurement methods but a reliable and rapid 3-D method would increase greatly the morphological information obtainable from natural teeth and dental models. Additional measurements such as crown heights, surface contours, actual surface perimeters and areas, and tooth volumes would maximise our ability to discriminate between samples and to explore more deeply genetic and environmental contributions to observed variation. The research objectives were to investigate the limitations of existing methodologies and to develop and validate new methods for obtaining true 3-D measurements, including curvatures and volumes, in order to enhance discrimination to allow increased differentiation in studies of dental morphology and development. The validity of a new methodology for the 3-D measurement of teeth is compared against an established 2-D system. The intra- and inter-observer reliability of some additional measurements, made possible with a 3-D approach, are also tested. Methods and results From each of 20 study models, the permanent upper right lateral and upper left central incisors were separated and imaged independently by two operators using 2-D image

  5. 3D analysis of condylar remodelling and skeletal relapse following bilateral sagittal split advancement osteotomies.

    Science.gov (United States)

    Xi, Tong; Schreurs, Ruud; van Loon, Bram; de Koning, Martien; Bergé, Stefaan; Hoppenreijs, Theo; Maal, Thomas

    2015-05-01

    A major concern in mandibular advancement surgery using bilateral sagittal split osteotomies (BSSO) is potential postoperative relapse. Although the role of postoperative changes in condylar morphology on skeletal relapse was reported in previous studies, no study so far has objectified the precise changes of the condylar volume. The aim of the present study was to quantify the postoperative volume changes of condyles and its role on skeletal stability following BSSO mandibular advancement surgery. A total of 56 patients with mandibular hypoplasia who underwent BSSO advancement surgery were prospectively enrolled into the study. A cone beam computed tomography (CBCT) scan was acquired preoperatively, at 1 week postoperatively and at 1 year postoperatively. After the segmentation of the facial skeleton and condyles, three-dimensional cephalometry and condylar volume analysis were performed. The mean mandibular advancement was 4.6 mm, and the mean postoperative relapse was 0.71 mm. Of 112 condyles, 55% showed a postoperative decrease in condylar volume, with a mean reduction of 105 mm(3) (6.1% of the original condylar volume). The magnitude of condylar remodelling (CR) was significantly correlated with skeletal relapse (p = 0.003). Patients with a CR greater than 17% of the original condylar volume exhibited relapse as seen in progressive condylar resorption. Female patients with a high mandibular angle who exhibited postoperative CR were particularly at risk for postoperative relapse. Gender, preoperative condylar volume, and downward displacement of pogonion at surgery were prognostic factors for CR (r(2) = 21%). It could be concluded that the condylar volume can be applied as a useful 3D radiographic parameter for the diagnosis and follow-up of postoperative skeletal relapse and progressive condylar resorption.

  6. Optical properties of 3d-ions in crystals spectroscopy and crystal field analysis

    CERN Document Server

    Brik, Mikhail

    2013-01-01

    "Optical Properties of 3d-Ions in Crystals: Spectroscopy and Crystal Field Analysis" discusses spectral, vibronic and magnetic properties of 3d-ions in a wide range of crystals, used as active media for solid state lasers and potential candidates for this role. Crystal field calculations (including first-principles calculations of energy levels and absorption spectra) and their comparison with experimental spectra, the Jahn-Teller effect, analysis of vibronic spectra, materials science applications are systematically presented. The book is intended for researchers and graduate students in crystal spectroscopy, materials science and optical applications. Dr. N.M. Avram is an Emeritus Professor at the Physics Department, West University of Timisoara, Romania; Dr. M.G. Brik is a Professor at the Institute of Physics, University of Tartu, Estonia.

  7. A Method for Sectioning and Immunohistochemical Analysis of Stem Cell-Derived 3-D Organoids.

    Science.gov (United States)

    Wiley, Luke A; Beebe, David C; Mullins, Robert F; Stone, Edwin M; Tucker, Budd A

    2016-05-12

    This unit describes a protocol for embedding, sectioning, and immunocytochemical analysis of pluripotent stem cell-derived 3-D organoids. Specifically, we describe a method to embed iPSC-derived retinal cups in low-melt agarose, acquire thick sections using a vibratome tissue slicer, and perform immunohistochemical analysis. This method includes an approach for antibody labeling that minimizes the amount of antibody needed for individual experiments and that utilizes large-volume washing to increase the signal-to-noise ratio, allowing for clean, high-resolution imaging of developing cell types. The universal methods described can be employed regardless of the type of pluripotent stem cell used and 3-D organoid generated. © 2016 by John Wiley & Sons, Inc.

  8. 3D hierarchical computational model of wood as a cellular material with fibril reinforced, heterogeneous multiple layers

    DEFF Research Database (Denmark)

    Qing, Hai; Mishnaevsky, Leon

    2009-01-01

    A 3D hierarchical computational model of deformation and stiffness of wood, which takes into account the structures of wood at several scale levels (cellularity, multilayered nature of cell walls, composite-like structures of the wall layers) is developed. At the mesoscale, the softwood cell...... is presented as a 3D hexagon-shape-tube with multilayered walls. The layers in the softwood cell are considered as considered as composite reinforced by microfibrils (celluloses). The elastic properties of the layers are determined with Halpin–Tsai equations, and introduced into mesoscale finite element...... cellular model. With the use of the developed hierarchical model, the influence of the microstructure, including microfibril angles (MFAs, which characterizes the orientation of the cellulose fibrils with respect to the cell axis), the thickness of the cell wall, the shape of the cell cross...

  9. Anthropological facial approximation in three dimensions (AFA3D): computer-assisted estimation of the facial morphology using geometric morphometrics.

    Science.gov (United States)

    Guyomarc'h, Pierre; Dutailly, Bruno; Charton, Jérôme; Santos, Frédéric; Desbarats, Pascal; Coqueugniot, Hélène

    2014-11-01

    This study presents Anthropological Facial Approximation in Three Dimensions (AFA3D), a new computerized method for estimating face shape based on computed tomography (CT) scans of 500 French individuals. Facial soft tissue depths are estimated based on age, sex, corpulence, and craniometrics, and projected using reference planes to obtain the global facial appearance. Position and shape of the eyes, nose, mouth, and ears are inferred from cranial landmarks through geometric morphometrics. The 100 estimated cutaneous landmarks are then used to warp a generic face to the target facial approximation. A validation by re-sampling on a subsample demonstrated an average accuracy of c. 4 mm for the overall face. The resulting approximation is an objective probable facial shape, but is also synthetic (i.e., without texture), and therefore needs to be enhanced artistically prior to its use in forensic cases. AFA3D, integrated in the TIVMI software, is available freely for further testing.

  10. 3D endobronchial ultrasound reconstruction and analysis for multimodal image-guided bronchoscopy

    Science.gov (United States)

    Zang, Xiaonan; Bascom, Rebecca; Gilbert, Christopher R.; Toth, Jennifer W.; Higgins, William E.

    2014-03-01

    State-of-the-art image-guided intervention (IGI) systems for lung-cancer management draw upon high-resolution three-dimensional multi-detector computed-tomography (MDCT) images and bronchoscopic video. An MDCT scan provides a high-resolution three-dimensional (3D) image of the chest that is used for preoperative procedure planning, while bronchoscopy gives live intraoperative video of the endobronchial airway tree structure. However, because neither source provides live extraluminal information on suspect nodules or lymph nodes, endobronchial ultrasound (EBUS) is often introduced during a procedure. Unfortunately, existing IGI systems provide no direct synergistic linkage between the MDCT/video data and EBUS data. Hence, EBUS proves difficult to use and can lead to inaccurate interpretations. To address this drawback, we present a prototype of a multimodal IGI system that brings together the various image sources. The system enables 3D reconstruction and visualization of structures depicted in the 2D EBUS video stream. It also provides a set of graphical tools that link the EBUS data directly to the 3D MDCT and bronchoscopic video. Results using phantom and human data indicate that the new system could potentially enable smooth natural incorporation of EBUS into the system-level work flow of bronchoscopy.

  11. GISAXS analysis of 3D nanoparticle assemblies--effect of vertical nanoparticle ordering.

    Science.gov (United States)

    Vegso, K; Siffalovic, P; Benkovicova, M; Jergel, M; Luby, S; Majkova, E; Capek, I; Kocsis, T; Perlich, J; Roth, S V

    2012-02-03

    We report on grazing-incidence small-angle x-ray scattering (GISAXS) study of 3D nanoparticle arrays prepared by two different methods from colloidal solutions-layer-by-layer Langmuir-Schaefer deposition and spontaneous self-assembling during the solvent evaporation. GISAXS results are evaluated within the distorted wave Born approximation (DWBA) considering the multiple scattering effects and employing a simplified multilayer model to reduce the computing time. In the model, particular layers are represented by nanoparticle chains where the positions of individual nanoparticles are generated following a model of cumulative disorder. The nanoparticle size dispersion is considered as well. Three model cases are distinguished-no shift between the neighboring chains (AA stacking), a shift equal to half of the mean interparticle distance (AB stacking) and random shift between the chains. The first two cases correspond to vertically correlated nanoparticle positions across different chains. A comparison of the experimental GISAXS patterns with the model cases enabled us to distinguish important differences between the 3D arrays prepared by the two methods. In particular, laterally ordered layers without vertical correlation of the nanoparticle positions were found in the nanoparticle multilayers prepared by the Langmuir-Schaefer method. On the other hand, the solvent evaporation under particular conditions produced highly ordered 3D nanoparticle assemblies where both laterally and vertically correlated nanoparticle positions were found.

  12. Optical parametric oscillators in isotropic photonic crystals and cavities: 3D time domain analysis

    OpenAIRE

    Conti, Claudio; Di Falco, Andrea; Assanto, Gaetano

    2004-01-01

    We investigate optical parametric oscillations through four-wave mixing in resonant cavities and photonic crystals. The theoretical analysis underlines the relevant features of the phenomenon and the role of the density of states. Using fully vectorial 3D time-domain simulations, including both dispersion and nonlinear polarization, for the first time we address this process in a face centered cubic lattice and in a photonic crystal slab. The results lead the way to the development of novel p...

  13. Analysis, Modeling and Dynamic Optimization of 3D Time-of-Flight Imaging Systems

    OpenAIRE

    Schmidt, Mirko

    2011-01-01

    The present thesis is concerned with the optimization of 3D Time-of-Flight (ToF) imaging systems. These novel cameras determine range images by actively illuminating a scene and measuring the time until the backscattered light is detected. Depth maps are constructed from multiple raw images. Usually two of such raw images are acquired simultaneously using special correlating sensors. This thesis covers four main contributions: A physical sensor model is presented which enables the analysis a...

  14. A 3D edge detection technique for surface extraction in computed tomography for dimensional metrology applications

    DEFF Research Database (Denmark)

    Yagüe-Fabra, J.A.; Ontiveros, S.; Jiménez, R.

    2013-01-01

    Many factors influence the measurement uncertainty when using computed tomography for dimensional metrology applications. One of the most critical steps is the surface extraction phase. An incorrect determination of the surface may significantly increase the measurement uncertainty. This paper pr...

  15. Strategy and software for the statistical spatial analysis of 3D intracellular distributions.

    Science.gov (United States)

    Biot, Eric; Crowell, Elizabeth; Burguet, Jasmine; Höfte, Herman; Vernhettes, Samantha; Andrey, Philippe

    2016-07-01

    The localization of proteins in specific domains or compartments in the 3D cellular space is essential for many fundamental processes in eukaryotic cells. Deciphering spatial organization principles within cells is a challenging task, in particular because of the large morphological variations between individual cells. We present here an approach for normalizing variations in cell morphology and for statistically analyzing spatial distributions of intracellular compartments from collections of 3D images. The method relies on the processing and analysis of 3D geometrical models that are generated from image stacks and that are used to build representations at progressively increasing levels of integration, ultimately revealing statistical significant traits of spatial distributions. To make this methodology widely available to end-users, we implemented our algorithmic pipeline into a user-friendly, multi-platform, and freely available software. To validate our approach, we generated 3D statistical maps of endomembrane compartments at subcellular resolution within an average epidermal root cell from collections of image stacks. This revealed unsuspected polar distribution patterns of organelles that were not detectable in individual images. By reversing the classical 'measure-then-average' paradigm, one major benefit of the proposed strategy is the production and display of statistical 3D representations of spatial organizations, thus fully preserving the spatial dimension of image data and at the same time allowing their integration over individual observations. The approach and software are generic and should be of general interest for experimental and modeling studies of spatial organizations at multiple scales (subcellular, cellular, tissular) in biological systems.

  16. 3D-analysis of the spay test 101 in the TOSQAN facility using GASFLOW II

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Un-Jang; Kim, Jong-Tae; Kim, Sang-Baik; Kim, Hee-Dong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Park, Goon-Cherl [Seoul National Univ., Seoul (Korea, Republic of)

    2006-07-01

    During the course of a hypothetical severe accident in a PWR, hydrogen can be produced by the reactor core oxidation and distributed into the reactor containment according to convection flows and water steam wall condensation. In order to prevent the over pressures in the event of a steam break, spray systems are used in the containment. However, the effect of a spray could even increase the risk of hydrogen explosion by condensing steam and therefore locally enriches hydrogen in gaseous mixtures. Thus, detailed understanding of the 3D thermal hydraulic conditions inside the containment is of high relevance for all aspects of accident management and mitigation. The computer code GASFLOW II has demonstrated its ability in the past to calculate the important thermal hydraulic processes during such severe accident sequences. GASFLOW gives a time dependent solution of the 3D Navier Stokes equations in cylindrical or cartesian coordinates. The validation of the code with scenario related 3D experimental data is required to use this code as a predictive tool for the simulation of such accidents in real reactor containments and for the design and verification of mitigation measures. Validation is therefore an essential part of code development.The validation of GASFLOW have focused on more recent experiments in the new containment test facilities ThAI, TOSQAN, and MISTRA. They have innovative 3D instrumentation for the validation of results from 3D CFD simulations. GASFLOW blindly predicted the pressure and temperature distribution for a MISTRA experiment and for the ThAI benchmark experiment TH7 quite well. The 3D experiment TH7 was performed without hydrogen release in a multi compartment geometry of the ThAI facility and involved a sequence of eccentric steam injections at high and low injection points followed by a heating phase. Also, the-state-of-art tests of the open TOSQAN benchmark (ISP 47) was analyzed with GASFLOW in a 2-D cylindrical geometry. Recently the

  17. Optimization of computations for adjoint field and Jacobian needed in 3D CSEM inversion

    Science.gov (United States)

    Dehiya, Rahul; Singh, Arun; Gupta, Pravin K.; Israil, M.

    2017-01-01

    We present the features and results of a newly developed code, based on Gauss-Newton optimization technique, for solving three-dimensional Controlled-Source Electromagnetic inverse problem. In this code a special emphasis has been put on representing the operations by block matrices for conjugate gradient iteration. We show how in the computation of Jacobian, the matrix formed by differentiation of system matrix can be made independent of frequency to optimize the operations at conjugate gradient step. The coarse level parallel computing, using OpenMP framework, is used primarily due to its simplicity in implementation and accessibility of shared memory multi-core computing machine to almost anyone. We demonstrate how the coarseness of modeling grid in comparison to source (comp`utational receivers) spacing can be exploited for efficient computing, without compromising the quality of the inverted model, by reducing the number of adjoint calls. It is also demonstrated that the adjoint field can even be computed on a grid coarser than the modeling grid without affecting the inversion outcome. These observations were reconfirmed using an experiment design where the deviation of source from straight tow line is considered. Finally, a real field data inversion experiment is presented to demonstrate robustness of the code.

  18. Patient-specific reconstruction utilizing computer assisted 3D modelling for partial bone flap defect in hybrid cranioplasty

    Science.gov (United States)

    Hueh, Low Peh; Abdullah, Johari Yap; Abdullah, Abdul Manaf; Yahya, Suzana; Idris, Zamzuri; Mohamad, Dasmawati

    2016-12-01

    Autologous cranioplasty using a patient's original bone flap remain the commonest practice nowadays. However, partial bone flap defect is commonly encountered. Replacing the bone flap with pre-moulded synthetic bone flap is costly and not affordable to many patients. Hence most of the small to medium size defect was topped up with alloplastic material on a free hand basis intra-operatively which often resulted in inaccurate implant approximation with unsatisfactory cosmetic result. This study aims to evaluate implant accuracy and cosmetic outcome of cranioplasty candidates who underwent partial bone flap reconstruction utilising computer assisted 3D modelling. 3D images of the skull were obtained from post-craniectomy axial 1-mm spiral computed tomography (CT) scans and a virtual 3D model was generated using the Materialise Mimics software. The Materialise 3-Matic was then utilised to design a patient-specific implant. Prefabrication of the implant was performed by the 3D Objet printer, and a negative gypsum mold was created with the prefabricated cranial implant. Intraoperatively, a hybrid polymethyl methacrylate (PMMA)-autologous cranial implant was produced using the gypsum mold, and fit into the cranial defect. This study is still ongoing at the moment. To date, two men has underwent partial bone flap reconstruction utilising this technique and both revealed satisfactory implant alignment with favourable cosmesis. Mean implant size was 12cm2, and the mean duration of intraoperative reconstruction for the partial bone flap defect was 40 minutes. No significant complication was reported. As a conclusion, this new technique and approach resulted in satisfactory implant alignment and favourable cosmetic outcome. However, more study samples are needed to increase the validity of the study results.

  19. Integrating Data Clustering and Visualization for the Analysis of 3D Gene Expression Data

    Energy Technology Data Exchange (ETDEWEB)

    Data Analysis and Visualization (IDAV) and the Department of Computer Science, University of California, Davis, One Shields Avenue, Davis CA 95616, USA,; nternational Research Training Group ``Visualization of Large and Unstructured Data Sets,' ' University of Kaiserslautern, Germany; Computational Research Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720, USA; Genomics Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley CA 94720, USA; Life Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley CA 94720, USA,; Computer Science Division,University of California, Berkeley, CA, USA,; Computer Science Department, University of California, Irvine, CA, USA,; All authors are with the Berkeley Drosophila Transcription Network Project, Lawrence Berkeley National Laboratory,; Rubel, Oliver; Weber, Gunther H.; Huang, Min-Yu; Bethel, E. Wes; Biggin, Mark D.; Fowlkes, Charless C.; Hendriks, Cris L. Luengo; Keranen, Soile V. E.; Eisen, Michael B.; Knowles, David W.; Malik, Jitendra; Hagen, Hans; Hamann, Bernd

    2008-05-12

    The recent development of methods for extracting precise measurements of spatial gene expression patterns from three-dimensional (3D) image data opens the way for new analyses of the complex gene regulatory networks controlling animal development. We present an integrated visualization and analysis framework that supports user-guided data clustering to aid exploration of these new complex datasets. The interplay of data visualization and clustering-based data classification leads to improved visualization and enables a more detailed analysis than previously possible. We discuss (i) integration of data clustering and visualization into one framework; (ii) application of data clustering to 3D gene expression data; (iii) evaluation of the number of clusters k in the context of 3D gene expression clustering; and (iv) improvement of overall analysis quality via dedicated post-processing of clustering results based on visualization. We discuss the use of this framework to objectively define spatial pattern boundaries and temporal profiles of genes and to analyze how mRNA patterns are controlled by their regulatory transcription factors.

  20. Application of 3D Spatio-Temporal Data Modeling, Management, and Analysis in DB4GEO

    Science.gov (United States)

    Kuper, P. V.; Breunig, M.; Al-Doori, M.; Thomsen, A.

    2016-10-01

    Many of todaýs world wide challenges such as climate change, water supply and transport systems in cities or movements of crowds need spatio-temporal data to be examined in detail. Thus the number of examinations in 3D space dealing with geospatial objects moving in space and time or even changing their shapes in time will rapidly increase in the future. Prominent spatio-temporal applications are subsurface reservoir modeling, water supply after seawater desalination and the development of transport systems in mega cities. All of these applications generate large spatio-temporal data sets. However, the modeling, management and analysis of 3D geo-objects with changing shape and attributes in time still is a challenge for geospatial database architectures. In this article we describe the application of concepts for the modeling, management and analysis of 2.5D and 3D spatial plus 1D temporal objects implemented in DB4GeO, our service-oriented geospatial database architecture. An example application with spatio-temporal data of a landfill, near the city of Osnabrück in Germany demonstrates the usage of the concepts. Finally, an outlook on our future research focusing on new applications with big data analysis in three spatial plus one temporal dimension in the United Arab Emirates, especially the Dubai area, is given.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Longtao; Qin, Min; Wang, Kai; Peng, Shiqi; Sun, Tianxi; Liu, Zhiguo [Beijing Normal University, College of Nuclear Science and Technology, Beijing (China); Lin, Xue [Northwest University, School of Cultural Heritage, Xi' an (China)

    2016-09-15

    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. (orig.)

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

    Science.gov (United States)

    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.

  3. Microstructure analysis of the secondary pulmonary lobules by 3D synchrotron radiation CT

    Science.gov (United States)

    Fukuoka, Y.; Kawata, Y.; Niki, N.; Umetani, K.; Nakano, Y.; Ohmatsu, H.; Moriyama, N.; Itoh, H.

    2014-03-01

    Recognition of abnormalities related to the lobular anatomy has become increasingly important in the diagnosis and differential diagnosis of lung abnormalities at clinical routines of CT examinations. This paper aims a 3-D microstructural analysis of the pulmonary acinus with isotropic spatial resolution in the range of several micrometers by using micro CT. Previously, we demonstrated the ability of synchrotron radiation micro CT (SRμCT) using offset scan mode in microstructural analysis of the whole part of the secondary pulmonary lobule. In this paper, we present a semiautomatic method to segment the acinar and subacinar airspaces from the secondary pulmonary lobule and to track small vessels running inside alveolar walls in human acinus imaged by the SRμCT. The method beains with and segmentation of the tissues such as pleural surface, interlobular septa, alveola wall, or vessel using a threshold technique and 3-D connected component analysis. 3-D air space are then conustructed separated by tissues and represented branching patterns of airways and airspaces distal to the terminal bronchiole. A graph-partitioning approach isolated acini whose stems are interactively defined as the terminal bronchiole in the secondary pulmonary lobule. Finally, we performed vessel tracking using a non-linear sate space which captures both smoothness of the trajectories and intensity coherence along vessel orientations. Results demonstrate that the proposed method can extract several acinar airspaces from the 3-D SRμCT image of secondary pulmonary lobule and that the extracted acinar airspace enable an accurate quantitative description of the anatomy of the human acinus for interpretation of the basic unit of pulmonary structure and function.

  4. Linearity of patient positioning detection. A phantom study of skin markers, cone beam computed tomography, and 3D ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Ballhausen, Hendrik; Hieber, Sheila; Li, Minglun; Belka, Claus; Reiner, Michael [University Hospital of LMU, Department of Radiation Oncology, Munich (Germany); Parodi, Katia [Ludwig-Maximilian-University, Department of Experimental Physics - Medical Physics, Munich (Germany)

    2015-05-01

    Three-dimensional ultrasound (3D-US) is a modality complementary to kilovoltage cone beam computed tomography (kV-CBCT) and skin markers for patient positioning detection. This study compares the linearity of evaluations based on measurements using a modern 3D-US system (Elekta Clarity {sup registered}; Elekta, Stockholm, Sweden), a kV-CBCT system (Elekta iView {sup registered}), and skin markers. An investigator deliberately displaced a multimodal phantom by up to ± 30 mm along different axes. The following data points were acquired: 27 along the lateral axis, 29 along the longitudinal axis, 27 along the vertical axis, and 27 along the space diagonal. At each of these 110 positions, the displacements according to skin' markers were recorded and scans were performed using both 3D-US and kV-CBCT. Shifts were detected by matching bony anatomy or soft tissue density to a reference planning CT in the case of kV-CBCT and for 3D-US, by matching ultrasound volume data to a reference planning volume. A consensus value was calculated from the average of the four modalities. With respect to this consensus value, the linearity (offset and regression coefficient, i.e., slope), average offset, systematic error, and random error of all four modalities were calculated for each axis. Linearity was similar for all four modalities, with regression coefficients between 0.994 and 1.012, and all offsets below 1 mm. The systematic errors of skin markers and 3D-US were higher than for kV-CBCT, but random errors were similar. In particular, 3D-US demonstrated an average offset of 0.36 mm to the right, 0.08 mm inferiorly, and 0.15 mm anteriorly; the systematic error was 0.36 mm laterally, 0.35 mm longitudinally, and 0.22 mm vertically; the random error was 0.15 mm laterally, 0.30 mm longitudinally, and 0.12 mm vertically. A total of 109 out of 110 (99 %) 3D-US measurements were within 1 mm of the consensus value on either axis. The linearity of 3D-US was no worse than that of skin

  5. Analysis of uncertainty and repeatability of a low-cost 3D laser scanner.

    Science.gov (United States)

    Polo, María-Eugenia; Felicísimo, Angel M

    2012-01-01

    Portable 3D laser scanners are a valuable tool for compiling elaborate digital collections of archaeological objects and analysing the shapes and dimensions of pieces. Although low-cost desktop 3D laser scanners have powerful capacities, it is important to know their limitations. This paper performs an analysis of the uncertainty and repeatability of the NextEngine™ portable low-cost 3D laser scanner by scanning an object 20 times in two different resolution modes-Macro and Wide. Some dimensions of the object were measured using a digital calliper, and these results were used as the "true" or control data. In comparing the true and the scanned data, we verified that the mean uncertainty in the Macro Mode is approximately half that of the Wide Mode, at ± 0.81 mm and ± 1.66 mm, respectively. These experimental results are significantly higher than the accuracy specifications provided by the manufacturer. An analysis of repeatability shows that the successive replicates do not match in the same position. The results are better in Macro Mode than in Wide Mode; it is observed that the repeatability factor is slightly larger than the corresponding mode accuracy, with ± 0.84 vs. ± 0.81 mm in Macro Mode and ± 1.82 vs. ± 1.66 mm in Wide Mode. We suggest several improvements, such as adding an external reference scale or providing a calibrated object to allow for a self-calibration operation of the scanner.

  6. 3D wind-induced response analysis of a cable-membrane structure

    Institute of Scientific and Technical Information of China (English)

    Jun-jie LUO; Da-jian HAN

    2009-01-01

    Wind loading is a dominant factor for design of a cable-membrane structure. Three orthogonal turbulent components, including the longitudinal, lateral and vertical wind velocities, should be taken into account for the wind loads. In this study, a stochastic 3D coupling wind field model is derived by the spectral representation theory, The coherence functions of the three orthognnal turbulent components are considered in this model. Then the model is applied to generate the three correlated wind turbulent components. After that, formulae are proposed to transform the velocities into wind loads, and to introduce the modified wind pressure force. Finally, a wind-induced time-history response analysis is conducted for a 3D cable-membrane structure. Analytical results indicate that responses induced by the proposed wind load model are 10%--25% larger than those by the con-ventionai uncorrelated model, and that the responses are not quite influenced by the modified wind pressure force. Therefore, we concluded that, in the time-history response analysis, the coherences of the three orthogonal turbulent components are necessary for a 3D cable-membrane structure, but the modified wind pressure force can be ignored.

  7. SHADOW EFFECT ON PHOTOVOLTAIC POTENTIALITY ANALYSIS USING 3D CITY MODELS

    Directory of Open Access Journals (Sweden)

    N. Alam

    2012-07-01

    Full Text Available Due to global warming, green-house effect and various other drawbacks of existing energy sources, renewable energy like Photovoltaic system is being popular for energy production. The result of photovoltaic potentiality analysis depends on data quality and parameters. Shadow rapidly decreases performance of the Photovoltaic system and it always changes due to the movement of the sun. Solar radiation incident on earth's atmosphere is relatively constant but the radiation at earth's surface varies due to absorption, scattering, reflection, change in spectral content, diffuse component, water vapor, clouds and pollution etc. In this research, it is being investigated that how efficiently real-time shadow can be detected for both direct and diffuse radiation considering reflection and other factors in contrast with the existing shadow detection methods using latest technologies and what is the minimum quality of data required for this purpose. Of course, geometric details of the building geometry and surroundings directly affect the calculation of shadows. In principle, 3D city models or point clouds, which contain roof structure, vegetation, thematically differentiated surface and texture, are suitable to simulate exact real-time shadow. This research would develop an automated procedure to measure exact shadow effect from the 3D city models and a long-term simulation model to determine the produced energy from the photovoltaic system. In this paper, a developed method for detecting shadow for direct radiation has been discussed with its result using a 3D city model to perform a solar energy potentiality analysis.

  8. Quasimodes instability analysis of uncertain asymmetric rotor system based on 3D solid element model

    Science.gov (United States)

    Zuo, Yanfei; Wang, Jianjun; Ma, Weimeng

    2017-03-01

    Uncertainties are considered in the equation of motion of an asymmetric rotor system. Based on Hill's determinant method, quasimodes stability analysis with uncertain parameters is used to get stochastic boundaries of unstable regions. Firstly, A 3D finite element rotor model was built in rotating frame with four parameterized coefficients, which is assumed as random parameters representing the uncertainties existing in the rotor system. Then the influences of uncertain coefficients on the distribution of the unstable region boundaries are analyzed. The results show that uncertain parameters have various influences on the size, boundary and number of unstable regions. At last, the statistic results of the minimum and maximum spin speeds of unstable regions were got by Monte Carlo simulation. The used method is suitable for real engineering rotor system, because arbitrary configuration of rotors can be modeled by 3D finite element.

  9. 3D-QSAR analysis of a new type of acetylcholinesterase inhibitors

    Institute of Scientific and Technical Information of China (English)

    LIU; AiLin; GUANG; HongMei; ZHU; LiYa; DU; GuanHua; LEE; Simon; M.; Y.; WANG; YiTao

    2007-01-01

    Acetylcholinesterase (AChE) inhibitors are an important class of medicinal agents used for the treatment of Alzheimer's disease. A screening model of AChE inhibitor was used to evaluate the inhibition of a series of phenyl pentenone derivatives. The assay result showed that some compounds displayed higher inhibitory effects. In order to study the relationship between the bioactivities and the structures, 26 compounds with phenyl pentenone scaffold were analyzed. A 3D-QSAR model was constructed using the method of comparative molecular field analysis (CoMFA). The results of cross-validated R2cv=0.629, non-cross-validated R2=0.972, SE=0.331, and F=72.41 indicate that the 3D-model possesses an ability to predict the activities of new inhibitors, and the CoMFA model would be useful for the future design of new AChE inhibitors.

  10. Experimental analysis of mechanical response of stabilized occipitocervical junction by 3D mark tracking technique

    Directory of Open Access Journals (Sweden)

    Brémand F.

    2010-06-01

    Full Text Available This study is about a biomechanical comparison of some stabilization solutions for the occipitocervical junction. Four kinds of occipito-cervical fixations are analysed in this work: lateral plates fixed by two kinds of screws, lateral plates fixed by hooks and median plate. To study mechanical rigidity of each one, tests have been performed on human skulls by applying loadings and by studying mechanical response of fixations and bone. For this experimental analysis, a specific setup has been developed to impose a load corresponding to the flexion-extension physiological movements. 3D mark tracking technique is employed to measure 3D displacement fields on the bone and on the fixations. Observations of displacement evolution on the bone according to the fixation show different rigidities given by each solution.

  11. Experimental analysis of mechanical response of stabilized occipitocervical junction by 3D mark tracking technique

    Science.gov (United States)

    Germaneau, A.; Doumalin, P.; Dupré, J. C.; Brèque, C.; Brémand, F.; D'Houtaud, S.; Rigoard, P.

    2010-06-01

    This study is about a biomechanical comparison of some stabilization solutions for the occipitocervical junction. Four kinds of occipito-cervical fixations are analysed in this work: lateral plates fixed by two kinds of screws, lateral plates fixed by hooks and median plate. To study mechanical rigidity of each one, tests have been performed on human skulls by applying loadings and by studying mechanical response of fixations and bone. For this experimental analysis, a specific setup has been developed to impose a load corresponding to the flexion-extension physiological movements. 3D mark tracking technique is employed to measure 3D displacement fields on the bone and on the fixations. Observations of displacement evolution on the bone according to the fixation show different rigidities given by each solution.

  12. Nonlinear analysis of chaotic flow in a 3D closed-loop pulsating heat pipe

    CERN Document Server

    Pouryoussefi, S M

    2016-01-01

    Numerical simulation has been conducted for the chaotic flow in a 3D closed-loop pulsating heat pipe (PHP). Heat flux and constant temperature boundary conditions were applied for evaporator and condenser sections, respectively. Water and ethanol were used as working fluids. Volume of Fluid (VOF) method has been employed for two-phase flow simulation. Spectral analysis of temperature time series was carried out using Power Spectrum Density (PSD) method. Existence of dominant peak in PSD diagram indicated periodic or quasi-periodic behavior in temperature oscillations at particular frequencies. Correlation dimension values for ethanol as working fluid was found to be higher than that for water under the same operating conditions. Similar range of Lyapunov exponent values for the PHP with water and ethanol as working fluids indicated strong dependency of Lyapunov exponent to the structure and dimensions of the PHP. An O-ring structure pattern was obtained for reconstructed 3D attractor at periodic or quasi-peri...

  13. ELASTIC BEHAVIOR ANALYSIS OF 3D ANGLE-INTERLOCK WOVEN CERAMIC COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Chang Yanjun; Jiao Guiqiong; Wang Bo; Liu Wei

    2006-01-01

    A micromechanical model for elastic behavior analysis of angle-interlock woven ceramic composites is proposed in this paper. This model takes into account the actual fabric structure by considering the fiber undulation and continuity in space, the cavities between adjacent yarns and the actual cross-section geometry of the yarn. Based on the laminate theory, the elastic properties of 3D angle-interlock woven ceramic composites are predicted. Different numbers of interlaced wefts have almost the same elastic moduli. The thickness of ceramic matrix has little effect on elastic moduli. When the undulation ratio increases longitudinal modulus decreases and the other Young's moduli increase. Good agreement between theoretical predictions and experimental results demonstrates the feasibility of the proposed model in analyzing the elastic properties of3D angle-interlock woven ceramic composites. The results of this paper verify the fact that the method of analyzing polyester matrix composites is suitable for woven ceramic composites.

  14. Speeding-up MADYMO 3D on serial and parallel computers using a portable coding environment

    NARCIS (Netherlands)

    Tsiandikos, T.; Rooijackers, H.F.L.; Asperen, F.G.J. van; Lupker, H.A.

    1996-01-01

    This paper outlines the strategy and methodology used to create a portable coding environment for the commercial package MADYMO. The objective is to design a global data structure that efficiently utilises the memory and cache of computers, so that one source code can be used for serial, vector and

  15. A computational model for estimating tumor margins in complementary tactile and 3D ultrasound images

    Science.gov (United States)

    Shamsil, Arefin; Escoto, Abelardo; Naish, Michael D.; Patel, Rajni V.

    2016-03-01

    Conventional surgical methods are effective for treating lung tumors; however, they impose high trauma and pain to patients. Minimally invasive surgery is a safer alternative as smaller incisions are required to reach the lung; however, it is challenging due to inadequate intraoperative tumor localization. To address this issue, a mechatronic palpation device was developed that incorporates tactile and ultrasound sensors capable of acquiring surface and cross-sectional images of palpated tissue. Initial work focused on tactile image segmentation and fusion of position-tracked tactile images, resulting in a reconstruction of the palpated surface to compute the spatial locations of underlying tumors. This paper presents a computational model capable of analyzing orthogonally-paired tactile and ultrasound images to compute the surface circumference and depth margins of a tumor. The framework also integrates an error compensation technique and an algebraic model to align all of the image pairs and to estimate the tumor depths within the tracked thickness of a palpated tissue. For validation, an ex vivo experimental study was conducted involving the complete palpation of 11 porcine liver tissues injected with iodine-agar tumors of varying sizes and shapes. The resulting tactile and ultrasound images were then processed using the proposed model to compute the tumor margins and compare them to fluoroscopy based physical measurements. The results show a good negative correlation (r = -0.783, p = 0.004) between the tumor surface margins and a good positive correlation (r = 0.743, p = 0.009) between the tumor depth margins.

  16. 3-D Computer Animation vs. Live-Action Video: Differences in Viewers' Response to Instructional Vignettes

    Science.gov (United States)

    Smith, Dennie; McLaughlin, Tim; Brown, Irving

    2012-01-01

    This study explored computer animation vignettes as a replacement for live-action video scenarios of classroom behavior situations previously used as an instructional resource in teacher education courses in classroom management strategies. The focus of the research was to determine if the embedded behavioral information perceived in a live-action…

  17. Computation of 3D steady Navier-Stokes flow with free-surface gravity waves

    NARCIS (Netherlands)

    Lewis, M.R.; Koren, B.; Raven, H.C.

    2003-01-01

    In this paper an iterative method for the computation of stationary gravity-wave solutions is investigated, using a novel formulation of the free-surface (FS) boundary-value problem. This method requires the solution of a sequence of stationary Reynolds-Averaged Navier-Stokes subproblems employing t

  18. Computation of 3D Steady Navier-Stokes Flow with Free-Surface Gravity Waves

    NARCIS (Netherlands)

    Lewis, M.R.; Koren, B.; Raven, H.C.

    2003-01-01

    In this paper an iterative method for the computation of stationary gravity-wave solutions is investigated, using a novel formulation of the free-surface (FS) boundary-value problem. This method requires the solution of a sequence of stationary Reynolds-Averaged Navier-Stokes subproblems employing t

  19. Computational 3D structures of drug-targeting proteins in the 2009-H1N1 influenza A virus

    Science.gov (United States)

    Du, Qi-Shi; Wang, Shu-Qing; Huang, Ri-Bo; Chou, Kuo-Chen

    2010-01-01

    The neuraminidase (NA) and M2 proton channel of influenza virus are the drug-targeting proteins, based on which several drugs were developed. However these once powerful drugs encountered drug-resistant problem to the H5N1 and H1N1 flu. To address this problem, the computational 3D structures of NA and M2 proteins of 2009-H1N1 influenza virus were built using the molecular modeling technique and computational chemistry method. Based on the models the structure features of NA and M2 proteins were analyzed, the docking structures of drug-protein complexes were computed, and the residue mutations were annotated. The results may help to solve the drug-resistant problem and stimulate designing more effective drugs against 2009-H1N1 influenza pandemic.

  20. Fixture-abutment connection surface and micro-gap measurements by 3D micro-tomographic technique analysis

    Directory of Open Access Journals (Sweden)

    Deborah Meleo

    2012-01-01

    Full Text Available X-ray micro-tomography (micro-CT is a miniaturized form of conventional computed axial tomography (CAT able to investigate small radio-opaque objects at a-few-microns high resolution, in a nondestructive, non-invasive, and tri-dimensional way. Compared to traditional optical and electron microscopy techniques, which provide two-dimensional images, this innovative investigation technology enables a sample tri-dimensional analysis without cutting, coating or exposing the object to any particular chemical treatment. X-ray micro-tomography matches ideal 3D microscopy features: the possibility of investigating an object in natural conditions and without any preparation or alteration; non-invasive, non-destructive, and sufficiently magnified 3D reconstruction; reliable measurement of numeric data of the internal structure (morphology, structure and ultra-structure. Hence, this technique has multi-fold applications in a wide range of fields, not only in medical and odontostomatologic areas, but also in biomedical engineering, materials science, biology, electronics, geology, archaeology, oil industry, and semi-conductors industry. This study shows possible applications of micro-CT in dental implantology to analyze 3D micro-features of dental implant to abutment interface. Indeed, implant-abutment misfit is known to increase mechanical stress on connection structures and surrounding bone tissue. This condition may cause not only screw preload loss or screw fracture, but also biological issues in peri-implant tissues.

  1. Panel Stiffener Debonding Analysis using a Shell/3D Modeling Technique

    Science.gov (United States)

    Krueger, Ronald; Ratcliffe, James G.; Minguet, Pierre J.

    2008-01-01

    A shear loaded, stringer reinforced composite panel is analyzed to evaluate the fidelity of computational fracture mechanics analyses of complex structures. Shear loading causes the panel to buckle. The resulting out -of-plane deformations initiate skin/stringer separation at the location of an embedded defect. The panel and surrounding load fixture were modeled with shell elements. A small section of the stringer foot, web and noodle as well as the panel skin near the delamination front were modeled with a local 3D solid model. Across the width of the stringer fo to, the mixed-mode strain energy release rates were calculated using the virtual crack closure technique. A failure index was calculated by correlating the results with a mixed-mode failure criterion of the graphite/epoxy material. The objective was to study the effect of the fidelity of the local 3D finite element model on the computed mixed-mode strain energy release rates and the failure index.

  2. 3D artificial bones for bone repair prepared by computed tomography-guided fused deposition modeling for bone repair.

    Science.gov (United States)

    Xu, Ning; Ye, Xiaojian; Wei, Daixu; Zhong, Jian; Chen, Yuyun; Xu, Guohua; He, Dannong

    2014-09-10

    The medical community has expressed significant interest in the development of new types of artificial bones that mimic natural bones. In this study, computed tomography (CT)-guided fused deposition modeling (FDM) was employed to fabricate polycaprolactone (PCL)/hydroxyapatite (HA) and PCL 3D artificial bones to mimic natural goat femurs. The in vitro mechanical properties, in vitro cell biocompatibility, and in vivo performance of the artificial bones in a long load-bearing goat femur bone segmental defect model were studied. All of the results indicate that CT-guided FDM is a simple, convenient, relatively low-cost method that is suitable for fabricating natural bonelike artificial bones. Moreover, PCL/HA 3D artificial bones prepared by CT-guided FDM have more close mechanics to natural bone, good in vitro cell biocompatibility, biodegradation ability, and appropriate in vivo new bone formation ability. Therefore, PCL/HA 3D artificial bones could be potentially be of use in the treatment of patients with clinical bone defects.

  3. Sentinel Lymph Node Detection by 3D Freehand Single-Photon Emission Computed Tomography in Early Stage Breast Cancer

    Directory of Open Access Journals (Sweden)

    Salih Sinan Gültekin

    2016-06-01

    Full Text Available We herein present our first experience obtained by 3D freehand single-photon emission computed tomography (SPECT (F-SPECT guidance for sentinel lymph node detection (SLND in two patients with early stage breast cancer. F-SPECT guidance was carried out using one-day protocol in one case and by the two-day protocol in the other one. SLND was performed successfully in both patients. Histopathologic evaluation showed that the excised nodes were tumor negative. Thus, patients underwent breast-conserving surgery alone.

  4. Accurate computation of Galerkin double surface integrals in the 3-D boundary element method

    CERN Document Server

    Adelman, Ross; Duraiswami, Ramani

    2015-01-01

    Many boundary element integral equation kernels are based on the Green's functions of the Laplace and Helmholtz equations in three dimensions. These include, for example, the Laplace, Helmholtz, elasticity, Stokes, and Maxwell's equations. Integral equation formulations lead to more compact, but dense linear systems. These dense systems are often solved iteratively via Krylov subspace methods, which may be accelerated via the fast multipole method. There are advantages to Galerkin formulations for such integral equations, as they treat problems associated with kernel singularity, and lead to symmetric and better conditioned matrices. However, the Galerkin method requires each entry in the system matrix to be created via the computation of a double surface integral over one or more pairs of triangles. There are a number of semi-analytical methods to treat these integrals, which all have some issues, and are discussed in this paper. We present novel methods to compute all the integrals that arise in Galerkin fo...

  5. Computer-aided determination of occlusal contact points for dental 3-D CAD.

    Science.gov (United States)

    Maruyama, Tomoaki; Nakamura, Yasuo; Hayashi, Toyohiko; Kato, Kazumasa

    2006-05-01

    Present dental CAD systems enable us to design functional occlusal tooth surfaces which harmonize with the patient's stomatognathic function. In order to avoid occlusal interferences during tooth excursions, currently available systems usually use the patient's functional occlusal impressions for the design of occlusal contact points. Previous interfere-free design, however, has been done on a trial-and-error basis by using visual inspection. To improve this time-consuming procedure, this paper proposes a computer-aided system for assisting in the determination of the occlusal contact points by visualizing the appropriate regions of the opposing surface. The system can designate such regions from data of the opposing occlusal surfaces and their relative movements can be simulated by using a virtual articulator. Experiments for designing the crown of a lower first molar demonstrated that all contact points selected within the designated regions completely satisfied the required contact or separation during tooth excursions, confirming the effectiveness of our computer-aided procedure.

  6. 3D strain map of axially loaded mouse tibia: a numerical analysis validated by experimental measurements.

    Science.gov (United States)

    Stadelmann, Vincent A; Hocke, Jean; Verhelle, Jensen; Forster, Vincent; Merlini, Francesco; Terrier, Alexandre; Pioletti, Dominique P

    2009-02-01

    A combined experimental/numerical study was performed to calculate the 3D octahedral shear strain map in a mouse tibia loaded axially. This study is motivated by the fact that the bone remodelling analysis, in this in vivo mouse model should be performed at the zone of highest mechanical stimulus to maximise the measured effects. Accordingly, it is proposed that quantification of bone remodelling should be performed at the tibial crest and at the distal diaphysis. The numerical model could also be used to furnish a more subtle analysis as a precise correlation between local strain and local biological response can be obtained with the experimentally validated numerical model.

  7. EVALUATION OF THE LIVER METASTASIS BY 3D-COMPUTED TOMOGRAPHY

    OpenAIRE

    Iuliana Eva; R.C. Tiutiuca

    2005-01-01

    Abdominal spiral computed tomography is the method of choice for the diagnosis of hepatic metastasis, evaluating lesions even under 10 mm. Treatment depends of the hepatic and extrahepatic spread of disease. Therapeutical options include surgical ablation (resection, enucleation, crioablation, radiofrequency, liver transplant) or non-surgical (embolization or chemoembolization, therapeutic aproach through the hepatic artery). Precise diagnostic and evaluation of the extension of the disease...

  8. Human factors flight trial analysis for 2D/3D SVS

    Science.gov (United States)

    Schiefele, Jens; Howland, Duncan; Maris, John; Wipplinger, Patrick

    2004-08-01

    The paper describes flight trials performed in Reno, NV. Flight trial were conducted with a Cheyenne 1 from Marinvent. Twelve pilots flew the Cheyenne in seventy-two approaches to the Reno airfield. All pilots flew completely andomized settings. Three different settings (standard displays, 2D moving map, and 2D/3D moving map) were evaluated. They included seamless evaluation for STAR, approach, and taxi operations. The flight trial goal was to evaluate the objective performance of pilots compared among the different settings. As dependent variables, positional and time accuracy were measured. Analysis was conducted by an ANOVA test. In parallel, all pilots answered subjective Cooper-Harper, situation awareness rating technique (SART), situational awareness probe (SAP), and questionnaires.This article describes the human factor analysis from flight trials performed in Reno, NV. Flight trials were conducted with a Cheyenne 1 from Marinvent. Thirteen pilots flew the Cheyenne in seventy-two approaches to the Reno airfield. All pilots flew completely randomized settings. Three different display configurations: Elec. Flight Information System (EFIS), EFIS and 2D moving map, and 3D SVS Primary Flight Display (PFD) and 2D moving map were evaluated. They included normal/abnormal procedure evaluation for: Steep turns and reversals, Unusual attitude recovery, Radar vector guidance towards terrain, Non-precision approaches, En-route alternate for non-IFR rated pilots encountering IMC, and Taxiing on complex taxi-routes. The flight trial goal was to evaluate the objective performance of pilots for the different display configurations. As dependent variables, positional and time data were measured. Analysis was performed by an ANOVA test. In parallel, all pilots answered subjective NASA Task Load Index, Cooper-Harper, Situation Awareness Rating Technique (SART), and questionnaires. The result shows that pilots flying 2D/3D SVS perform no worse than pilots with conventional

  9. Action Sport Cameras as an Instrument to Perform a 3D Underwater Motion Analysis.

    Science.gov (United States)

    Bernardina, Gustavo R D; Cerveri, Pietro; Barros, Ricardo M L; Marins, João C B; Silvatti, Amanda P

    2016-01-01

    Action sport cameras (ASC) are currently adopted mainly for entertainment purposes but their uninterrupted technical improvements, in correspondence of cost decreases, are going to disclose them for three-dimensional (3D) motion analysis in sport gesture study and athletic performance evaluation quantitatively. Extending this technology to sport analysis however still requires a methodologic step-forward to making ASC a metric system, encompassing ad-hoc camera setup, image processing, feature tracking, calibration and 3D reconstruction. Despite traditional laboratory analysis, such requirements become an issue when coping with both indoor and outdoor motion acquisitions of athletes. In swimming analysis for example, the camera setup and the calibration protocol are particularly demanding since land and underwater cameras are mandatory. In particular, the underwater camera calibration can be an issue affecting the reconstruction accuracy. In this paper, the aim is to evaluate the feasibility of ASC for 3D underwater analysis by focusing on camera setup and data acquisition protocols. Two GoPro Hero3+ Black (frequency: 60Hz; image resolutions: 1280×720/1920×1080 pixels) were located underwater into a swimming pool, surveying a working volume of about 6m3. A two-step custom calibration procedure, consisting in the acquisition of one static triad and one moving wand, carrying nine and one spherical passive markers, respectively, was implemented. After assessing camera parameters, a rigid bar, carrying two markers at known distance, was acquired in several positions within the working volume. The average error upon the reconstructed inter-marker distances was less than 2.5mm (1280×720) and 1.5mm (1920×1080). The results of this study demonstrate that the calibration of underwater ASC is feasible enabling quantitative kinematic measurements with accuracy comparable to traditional motion capture systems.

  10. Enhancement of REBUS-3/DIF3D for whole-core neutronic analysis of prismatic very high temperature reactor (VHTR).

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C. H.; Zhong, Z.; Taiwo, T.A.; Yang, W.S.; Khalil, H.S.; Smith, M.A.; Nuclear Engineering Division

    2006-10-13

    Enhancements have been made to the REBUS-3/DIF3D code suite to facilitate its use for the design and analysis of prismatic Very High Temperature Reactors (VHTRs). A new cross section structure, using table-lookup, has been incorporated to account for cross section changes with burnup and fuel and moderator temperatures. For representing these cross section dependencies, three new modules have been developed using FORTRAN 90/95 object-oriented data structures and implemented within the REBUS-3 code system. These modules provide a cross section storage procedure, construct microscopic cross section data for all isotopes, and contain a single block of banded scattering data for efficient data management. Fission products other than I, Xe, Pm, and Sm, can be merged into a single lumped fission product to save storage space, memory, and computing time without sacrificing the REBUS-3 solution accuracy. A simple thermal-hydraulic (thermal-fluid) feedback model has been developed for prismatic VHTR cores and implemented in REBUS-3 for temperature feedback calculations. Axial conduction was neglected in the formulation because of its small magnitude compared to radial (planar) conduction. With the simple model, the average fuel and graphite temperatures are accurately estimated compared to reference STAR-CD results. The feedback module is currently operational for the non-equilibrium fuel cycle analysis option of REBUS-3. Future work should include the extension of this capability to the equilibrium cycle option of the code and additional verification of the feedback module. For the simulation of control rods in VHTR cores, macroscopic cross section deviations (deltas) have been defined to account for the effect of control rod insertion. The REBUS-3 code has been modified to use the appropriately revised cross sections when control rods are inserted in a calculation node. In order to represent asymmetric core blocks (e.g., fuel blocks or reflector blocks containing

  11. Performance Analysis of 3D Massive MIMO Cellular Systems with Collaborative Base Station

    Directory of Open Access Journals (Sweden)

    Xingwang Li

    2014-01-01

    Full Text Available Massive MIMO have drawn considerable attention as they enable significant capacity and coverage improvement in wireless cellular network. However, pilot contamination is a great challenge in massive MIMO systems. Under this circumstance, cooperation and three-dimensional (3D MIMO are emerging technologies to eliminate the pilot contamination and to enhance the performance relative to the traditional interference-limited implementations. Motivated by this, we investigate the achievable sum rate performance of MIMO systems in the uplink employing cooperative base station (BS and 3D MIMO systems. In our model, we consider the effects of both large-scale and small-scale fading, as well as the spatial correlation and indoor-to-outdoor high-rise propagation environment. In particular, we investigate the cooperative communication model based on 3D MIMO and propose a closed-form lower bound on the sum rate. Utilizing this bound, we pursue a “large-system” analysis and provide the asymptotic expression when the number of antennas at the BS grows large, and when the numbers of antennas at transceiver grow large with a fixed ratio. We demonstrate that the lower bound is very tight and becomes exact in the massive MIMO system limits. Finally, under the sum rate maximization condition, we derive the optimal number of UTs to be served.

  12. Analysis of 3d Magnetotelluric Measurements Over the Coso Geothermal Field

    Science.gov (United States)

    Newman, G. A.; Gasperikova, E.; Hoversten, M.

    2007-12-01

    We have carried out an investigation of the Coso Geothermal field utilizing a dense grid of magnetotelluric (MT) stations plus a single line of contiguous bipole array profiling over the east flank of the field. Motivation for this study is that electrical resistivity/conductivity mapping can contribute to better understanding of enhanced geothermal systems (EGS) by imaging the geometry, bounds and controlling structures in existing production, and by monitoring changes in the underground resistivity properties in the vicinity of injection due to fracture porosity enhancement. Initial analysis of the Coso MT data was carried out using 2D MT imaging technology to construct a starting 3D resistivity model from a series of 2D resistivity images obtained using the inline electric field measurements (Zxy impedance elements) along different measurement transects. This model was then refined through a 3D inversion process. The 3D resisitivity model clearly showed the controlling geological structures influencing well production at Coso and shows correlations with mapped surface features such as faults and regional geoelectric strike. We have also correlated the model with an acoustic and shear velocity model of the field to show that the near-vertical high conductivity (low resistivity) structure on the eastern flank of the producing field is also a zone of increase acoustic velocity and increased Vp/Vs ratio.

  13. 3D Product authenticity model for online retail: An invariance analysis

    Directory of Open Access Journals (Sweden)

    Algharabat, R.

    2010-01-01

    Full Text Available This study investigates the effects of different levels of invariance analysis on three dimensional (3D product authenticity model (3DPAM constructs in the e- retailing context. A hypothetical retailer website presents a variety of laptops using 3D product visualisations. The proposed conceptual model achieves acceptable fit and the hypothesised paths are all valid. We empirically investigate the invariance across the subgroups to validate the results of our 3DPAM. We concluded that the 3D product authenticity model construct was invariant for our sample across different gender, level of education and study backgrounds. These findings suggested that all our subgroups conceptualised the 3DPAM similarly. Also the results show some non-invariance results for the structural and latent mean models. The gender group posits a non-invariance latent mean model. Study backgrounds group reveals a non-invariance result for the structural model. These findings allowed us to understand the 3DPAMs validity in the e-retail context. Managerial implications are explained.

  14. 3D distribution of interstellar medium in the Galaxy: Preparation for analysis of Gaia observations

    Energy Technology Data Exchange (ETDEWEB)

    Puspitarini, Lucky, E-mail: rosine.lallement@obspm.fr [GEPI Observatoire de Paris, CNRS, Paris Diderot University, 5 Place Jules Janssen, 92190, Meudon (France); Bosscha Observatory and Department of Astronomy, FMIPA, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia); Lallement, Rosine, E-mail: rosine.lallement@obspm.fr [GEPI Observatoire de Paris, CNRS, Paris Diderot University, 5 Place Jules Janssen, 92190, Meudon (France)

    2015-09-30

    Accurate and detailed three-dimensional (3D) maps of Galactic interstellar medium (ISM) are still lacking. One way to obtain such 3D descriptions is to record a large set of individual absorption or reddening measurements toward target stars located at various known distances and directions. The inversion of these measurements using a tomographic method can produce spatial distribution of the ISM. Until recently absorption data were very limited and distances to the target stars are still uncertain, but the situation will greatly improve thanks to current and future massive stellar surveys from ground, and to Gaia mission. To prepare absorption data for inversion from a huge number of stellar spectra, automated tools are needed. We have developed various spectral analysis tools adapted to different type of spectra, early- or late- type star. We also have used diffuse interstellar bands (DIBs) to trace IS structures and kinematics. Although we do not know yet their carriers, they can be a promising tool to trace distant interstellar clouds or Galactic arms. We present some examples of the interstellar fitting and show the potentiality of DIBs in tracing the ISM. We will also briefly show and comment the latest 3D map of the local ISM which reveal nearby cloud complexes and cavities.

  15. Uncertainty analysis in 3D global models: Aerosol representation in MOZART-4

    Science.gov (United States)

    Gasore, J.; Prinn, R. G.

    2012-12-01

    The Probabilistic Collocation Method (PCM) has been proven to be an efficient general method of uncertainty analysis in atmospheric models (Tatang et al 1997, Cohen&Prinn 2011). However, its application has been mainly limited to urban- and regional-scale models and chemical source-sink models, because of the drastic increase in computational cost when the dimension of uncertain parameters increases. Moreover, the high-dimensional output of global models has to be reduced to allow a computationally reasonable number of polynomials to be generated. This dimensional reduction has been mainly achieved by grouping the model grids into a few regions based on prior knowledge and expectations; urban versus rural for instance. As the model output is used to estimate the coefficients of the polynomial chaos expansion (PCE), the arbitrariness in the regional aggregation can generate problems in estimating uncertainties. To address these issues in a complex model, we apply the probabilistic collocation method of uncertainty analysis to the aerosol representation in MOZART-4, which is a 3D global chemical transport model (Emmons et al., 2010). Thereafter, we deterministically delineate the model output surface into regions of homogeneous response using the method of Principal Component Analysis. This allows the quantification of the uncertainty associated with the dimensional reduction. Because only a bulk mass is calculated online in Mozart-4, a lognormal number distribution is assumed with a priori fixed scale and location parameters, to calculate the surface area for heterogeneous reactions involving tropospheric oxidants. We have applied the PCM to the six parameters of the lognormal number distributions of Black Carbon, Organic Carbon and Sulfate. We have carried out a Monte-Carlo sampling from the probability density functions of the six uncertain parameters, using the reduced PCE model. The global mean concentration of major tropospheric oxidants did not show a

  16. A Method for 3D Histopathology Reconstruction Supporting Mouse Microvasculature Analysis.

    Directory of Open Access Journals (Sweden)

    Yiwen Xu

    Full Text Available Structural abnormalities of the microvasculature can impair perfusion and function. Conventional histology provides good spatial resolution with which to evaluate the microvascular structure but affords no 3-dimensional information; this limitation could lead to misinterpretations of the complex microvessel network in health and disease. The objective of this study was to develop and evaluate an accurate, fully automated 3D histology reconstruction method to visualize the arterioles and venules within the mouse hind-limb. Sections of the tibialis anterior muscle from C57BL/J6 mice (both normal and subjected to femoral artery excision were reconstructed using pairwise rigid and affine registrations of 5 µm-thick, paraffin-embedded serial sections digitized at 0.25 µm/pixel. Low-resolution intensity-based rigid registration was used to initialize the nucleus landmark-based registration, and conventional high-resolution intensity-based registration method. The affine nucleus landmark-based registration was developed in this work and was compared to the conventional affine high-resolution intensity-based registration method. Target registration errors were measured between adjacent tissue sections (pairwise error, as well as with respect to a 3D reference reconstruction (accumulated error, to capture propagation of error through the stack of sections. Accumulated error measures were lower (p < 0.01 for the nucleus landmark technique and superior vasculature continuity was observed. These findings indicate that registration based on automatic extraction and correspondence of small, homologous landmarks may support accurate 3D histology reconstruction. This technique avoids the otherwise problematic "banana-into-cylinder" effect observed using conventional methods that optimize the pairwise alignment of salient structures, forcing them to be section-orthogonal. This approach will provide a valuable tool for high-accuracy 3D histology tissue

  17. ALGEBRAIC TURBULENCE MODEL WITH MEMORY FOR COMPUTATION OF 3-D TURBULENT BOUNDARY LAYERS WITH VALIDATION

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Additional equations were found based on experiments for an algebraic turbulence model to improve the prediction of the behavior of three dimensional turbulent boundary layers by taking account of the effects of pressure gradient and the historical variation of eddy viscosity, so the model is with memory. Numerical calculation by solving boundary layer equations was carried out for the five pressure driven three dimensional turbulent boundary layers developed on flat plates, swept-wing, and prolate spheroid in symmetrical plane. Comparing the computational results with the experimental data, it is obvious that the prediction will be more accurate if the proposed closure equations are used, especially for the turbulent shear stresses.

  18. The Computational Complexity of Portal and Other 3D Video Games

    OpenAIRE

    Erik D. Demaine; Lockhart, Joshua; Lynch, Jayson

    2016-01-01

    We classify the computational complexity of the popular video games Portal and Portal 2. We isolate individual mechanics of the game and prove NP-hardness, PSPACE-completeness, or (pseudo)polynomiality depending on the specific game mechanics allowed. One of our proofs generalizes to prove NP-hardness of many other video games such as Half-Life 2, Halo, Doom, Elder Scrolls, Fallout, Grand Theft Auto, Left 4 Dead, Mass Effect, Deus Ex, Metal Gear Solid, and Resident Evil. These results build o...

  19. Computer simulation of 2-D and 3-D ion beam extraction and acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Ido, Shunji; Nakajima, Yuji [Saitama Univ., Urawa (Japan). Faculty of Engineering

    1997-03-01

    The two-dimensional code and the three-dimensional code have been developed to study the physical features of the ion beams in the extraction and acceleration stages. By using the two-dimensional code, the design of first electrode(plasma grid) is examined in regard to the beam divergence. In the computational studies by using the three-dimensional code, the axis-off model of ion beam is investigated. It is found that the deflection angle of ion beam is proportional to the gap displacement of the electrodes. (author)

  20. Computational studies of hard-body and 3-D effects in plume flows

    Science.gov (United States)

    Venkatapathy, Ethiraj; Feiereisen, William J.; Obayashi, Shigeru

    1989-01-01

    Axisymmetric and three-dimensional, multi-nozzle plume flows around generic rocket geometries are investigated with a three-dimensional Navier-Stokes solver to study the interactive effects between hard body and the plume. Time-asymptotic, laminar, ideal-gas solutions obtained with a two-factor, flux-split scheme and a diagonal, upwind scheme are presented. Computed solutions to three-dimensional, multi-nozzle problems and single-nozzle, axisymmetric problems demonstrate flow field features including three-dimensionality and hard-body effects. Geometry and three-dimensional effects are shown to be significant in multi-nozzle flows.

  1. Simplified 3D model of a PWR reactor vessel using fluid dynamics code ANSYS CFX computational; Modelo simplificado 3D de la vasija de un reactor PWR mediante el codigo de dinamica de fluidos computacional ANSYS CFX

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, M.; Miro, R.; Barrachina, T.; Verdu, G.

    2011-07-01

    This paper presents the results from the calculation of the steady state simulation with model of CFD (computational fluid dynamic) operating under conditions of operation at full power (Hot Full Power). Development and the CFD model results show the usefulness of these codes for calculating 3D of the variable thermohydraulics of these reactors.

  2. Comparison of predicting drag methods using computational fluid dynamics in 2d/3d viscous flow

    Institute of Scientific and Technical Information of China (English)

    ZHU; ZiQiang; WANG; XiaoLu; LIU; Jie; LIU; Zhou

    2007-01-01

    As a result of the necessity of aircraft engineering design and the progress of computational fluid dynamics (CFD), techniques of accurately predicting aerodynamic drag are being increasingly explored. According to the momentum balance, the drag can be represented by an integral over a cross-flow plane (called wake integration method) at an arbitrary distance behind the configuration. A formulation to reduce the size of the wake cross plane region required for calculating the drag is developed by using cutoff parameters of vorticity and entropy. This increases the calculation accuracy and decreases the computation time required. Numerical experiments are made to obtain the threshold values of these cutoff parameters. The wake integration method is applied to predict drags of some examples including airfoil, a variety of wings and wing-body combination. Numerical results are compared with those of traditional surface integration method, showing that the predicting drag values with the wake integration method are closer to the experimental data. The results also show that drag prediction within engineering accuracy is possible by using CFD and the numerical drag optimization of complex aircraft configurations is possible, too.

  3. Fast and Precise 3D Computation of Capacitance of Parallel Narrow Beam MEMS Structures

    CERN Document Server

    Majumdar, N

    2007-01-01

    Efficient design and performance of electrically actuated MEMS devices necessitate accurate estimation of electrostatic forces on the MEMS structures. This in turn requires thorough study of the capacitance of the structures and finally the charge density distribution on the various surfaces of a device. In this work, nearly exact BEM solutions have been provided in order to estimate these properties of a parallel narrow beam structure found in MEMS devices. The effect of three-dimensionality, which is an important aspect for these structures, and associated fringe fields have been studied in detail. A reasonably large parameter space has been covered in order to follow the variation of capacitance with various geometric factors. The present results have been compared with those obtained using empirical parametrized expressions keeping in view the requirement of the speed of computation. The limitations of the empirical expressions have been pointed out and possible approaches of their improvement have been d...

  4. A PLS QSAR analysis using 3D generated aromatic descriptors of principal property type: Application to some dopamine D2 benzamide antagonists

    Science.gov (United States)

    Norinder, Ulf

    1993-12-01

    A simple and computationally nonintensive technique based on principal component analysis of 3D fields to derive theoretical descriptors is presented. The descriptors are then applied to a quantitative structure-activity relationship study on some dopamine D2 antagonists of benzamide type.

  5. Semi-automated 3D leaf reconstruction and analysis of trichome patterning from light microscopic images.

    Directory of Open Access Journals (Sweden)

    Henrik Failmezger

    2013-04-01

    Full Text Available Trichomes are leaf hairs that are formed by single cells on the leaf surface. They are known to be involved in pathogen resistance. Their patterning is considered to emerge from a field of initially equivalent cells through the action of a gene regulatory network involving trichome fate promoting and inhibiting factors. For a quantitative analysis of single and double mutants or the phenotypic variation of patterns in different ecotypes, it is imperative to statistically evaluate the pattern reliably on a large number of leaves. Here we present a method that enables the analysis of trichome patterns at early developmental leaf stages and the automatic analysis of various spatial parameters. We focus on the most challenging young leaf stages that require the analysis in three dimensions, as the leaves are typically not flat. Our software TrichEratops reconstructs 3D surface models from 2D stacks of conventional light-microscope pictures. It allows the GUI-based annotation of different stages of trichome development, which can be analyzed with respect to their spatial distribution to capture trichome patterning events. We show that 3D modeling removes biases of simpler 2D models and that novel trichome patterning features increase the sensitivity for inter-accession comparisons.

  6. 3D visualisation and analysis of single and coalescing tracks in Solid state Nuclear Track Detectors

    Science.gov (United States)

    Wertheim, David; Gillmore, Gavin; Brown, Louise; Petford, Nick

    2010-05-01

    Exposure to radon gas (222Rn) and associated ionising decay products can cause lung cancer in humans (1). Solid state Nuclear Track Detectors (SSNTDs) can be used to monitor radon concentrations (2). Radon particles form tracks in the detectors and these tracks can be etched in order to enable 2D surface image analysis. We have previously shown that confocal microscopy can be used for 3D visualisation of etched SSNTDs (3). The aim of the study was to further investigate track angles and patterns in SSNTDs. A 'LEXT' confocal laser scanning microscope (Olympus Corporation, Japan) was used to acquire 3D image datasets of five CR-39 plastic SSNTD's. The resultant 3D visualisations were analysed by eye and inclination angles assessed on selected tracks. From visual assessment, single isolated tracks as well as coalescing tracks were observed on the etched detectors. In addition varying track inclination angles were observed. Several different patterns of track formation were seen such as single isolated and double coalescing tracks. The observed track angles of inclination may help to assess the angle at which alpha particles hit the detector. Darby, S et al. Radon in homes and risk of lung cancer : collaborative analysis of individual data from 13 European case-control studies. British Medical Journal 2005; 330, 223-226. Phillips, P.S., Denman, A.R., Crockett, R.G.M., Gillmore, G., Groves-Kirkby, C.J., Woolridge, A., Comparative Analysis of Weekly vs. Three monthly radon measurements in dwellings. DEFRA Report No., DEFRA/RAS/03.006. (2004). Wertheim D, Gillmore G, Brown L, and Petford N. A new method of imaging particle tracks in Solid State Nuclear Track Detectors. Journal of Microscopy 2010; 237: 1-6.

  7. A Computationally-Efficient Kinetic Approach for Gas/Particle Mass Transfer Treatments: Development, Testing, and 3-D Application

    Science.gov (United States)

    Hu, X.; Zhang, Y.

    2007-05-01

    The Weather Research and Forecast/Chemistry Model (WRF/Chem) that simulates chemistry simultaneously with meteorology has recently been developed for real-time forecasting by the U.S. National Center for Atmospheric Research (NCAR) and National Oceanic & Atmospheric Administration (NOAA). As one of the six air quality models, WRF/Chem with a modal aerosol module has been applied for ozone and PM2.5 ensemble forecasts over eastern North America as part of the 2004 New England Air Quality Study (NEAQS) program (NEAQS-2004). Significant differences exist in the partitioning of volatile species (e.g., ammonium and nitrate) simulated by the six models. Model biases are partially attributed to the equilibrium assumption used in the gas/particles mass transfer approach in some models. Development of a more accurate, yet computationally- efficient gas/particle mass transfer approach for three-dimensional (3-D) applications, in particular, real-time forecasting, is therefore warranted. Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution (MADRID) has been implemented into WRF/Chem (referred to as WRF/Chem-MADRID). WRF/Chem-MADRID offers three gas/particle partitioning treatments: equilibrium, kinetic, and hybrid approaches. The equilibrium approach is computationally-efficient and commonly used in 3-D air quality models but less accurate under certain conditions (e.g., in the presence of coarse, reactive particles such as PM containing sea-salts in the coastal areas). The kinetic approach is accurate but computationally-expensive, limiting its 3-D applications. The hybrid approach attempts to provide a compromise between merits and drawbacks of the two approaches by treating fine PM (typically MADRID has recently been developed for 3-D applications based on an Analytical Predictor of Condensation (referred to as kinetic/APC). In this study, WRF/Chem-MADRID with the kinetic/APC approach will be further evaluated along with the equilibrium and hybrid approaches

  8. 3D time-dependent flow computations using a molecular stress function model with constraint release

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz

    2002-01-01

    The numerical simulation of time dependent viscoelastic flow (in three dimensions) is of interest in connection with a variety of polymer processing operations. The application of the numerical simulation techniques is in the analysis and design of polymer processing problems. This is operations,...

  9. Regulative processes in individual, 3D and computer supported cooperative learning contexts

    NARCIS (Netherlands)

    Jong, de Frank; Kollöffel, Bas; Meijden, van der Henny; Kleine Staarman, Judith; Janssen, Jeroen

    2005-01-01

    Three studies of student regulation of learning were undertaken. In the first study, the temporal organization of the self-regulation process was examined within an individual learning context. Multilevel analysis showed linear and quadratic relations between self-regulation process and the phase of

  10. Analysis of the Possibilities of Using Low-Cost Scanning System in 3d Modeling

    Science.gov (United States)

    Kedzierski, M.; Wierzbickia, D.; Fryskowska, A.; Chlebowska, B.

    2016-06-01

    The laser scanning technique is still a very popular and fast growing method of obtaining information on modeling 3D objects. The use of low-cost miniature scanners creates new opportunities for small objects of 3D modeling based on point clouds acquired from the scan. The same, the development of accuracy and methods of automatic processing of this data type is noticeable. The article presents methods of collecting raw datasets in the form of a point-cloud using a low-cost ground-based laser scanner FabScan. As part of the research work 3D scanner from an open source FabLab project was constructed. In addition, the results for the analysis of the geometry of the point clouds obtained by using a low-cost laser scanner were presented. Also, some analysis of collecting data of different structures (made of various materials such as: glass, wood, paper, gum, plastic, plaster, ceramics, stoneware clay etc. and of different shapes: oval and similar to oval and prism shaped) have been done. The article presents two methods used for analysis: the first one - visual (general comparison between the 3D model and the real object) and the second one - comparative method (comparison between measurements on models and scanned objects using the mean error of a single sample of observations). The analysis showed, that the low-budget ground-based laser scanner FabScan has difficulties with collecting data of non-oval objects. Items built of glass painted black also caused problems for the scanner. In addition, the more details scanned object contains, the lower the accuracy of the collected point-cloud is. Nevertheless, the accuracy of collected data (using oval-straight shaped objects) is satisfactory. The accuracy, in this case, fluctuates between ± 0,4 mm and ± 1,0 mm whereas when using more detailed objects or a rectangular shaped prism the accuracy is much more lower, between 2,9 mm and ± 9,0 mm. Finally, the publication presents the possibility (for the future expansion of

  11. Correction of magnetotelluric static shift by analysis of 3D forward modelling and measured test data

    Science.gov (United States)

    Zhang, Kun; Wei, Wenbo; Lu, Qingtian; Wang, Huafeng; Zhang, Yawei

    2016-06-01

    To solve the problem of correction of magnetotelluric (MT) static shift, we quantise factors that influence geological environments and observation conditions and study MT static shift according to 3D MT numerical forward modelling and field tests with real data collection. We find that static shift distortions affect both the apparent resistivity and the impedance phase. The distortion results are also related to the frequency. On the basis of synthetic and real data analysis, we propose the concept of generalised static shift resistivity (GSSR) and a new method for correcting MT static shift. The approach is verified by studying 2D inversion models using synthetic and real data.

  12. THEORETICAL ANALYSIS OF COORDINATES MEASUREMENT BY FLEXIBLE 3D MEASURING SYSTEM

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guoyu; SUN Tianxiang; WANG Lingyun; XU Xiping

    2007-01-01

    The system mathematical model of flexible 3D measuring system is built by theoretical analysis, and the theoretical formula for measuring space point coordinate is also derived.Frog-jumping based coordinate transform method is put forward in order to solve measuring problem for large size parts. The flog-jumping method is discussed, and the coordinate transform mathematical model is method of the space point coordinate compared to original value, and an advanced method is provided. Form the space point coordinate transform formula can derive the calculation measuring method for measuring large size parts.

  13. High Resolution 3D Earth Observation Data Analysis for Safeguards Activities

    OpenAIRE

    d'Angelo, Pablo; Rossi, Cristian; Minet, Christian; Eineder, Michael; Flory, Michael; Niemeyer, Irmgard

    2014-01-01

    This paper provides an overview of the investigations performed at DLR with respect to the application of high resolution SAR and optical data for 3D analysis in the context of Safeguards. The Research Center Jülich and the adjacent open cut mines were used as main test sites, and a comprehensive stack of ascending and descending TerraSAR data was acquired over two years. TerraSAR data acquisition was performed, and various ways to visualize and analyze stacks of radar images w...

  14. ANALYSIS OF THE POSSIBILITIES OF USING LOW-COST SCANNING SYSTEM IN 3D MODELING

    Directory of Open Access Journals (Sweden)

    M. Kedzierski

    2016-06-01

    Full Text Available The laser scanning technique is still a very popular and fast growing method of obtaining information on modeling 3D objects. The use of low-cost miniature scanners creates new opportunities for small objects of 3D modeling based on point clouds acquired from the scan. The same, the development of accuracy and methods of automatic processing of this data type is noticeable. The article presents methods of collecting raw datasets in the form of a point-cloud using a low-cost ground-based laser scanner FabScan. As part of the research work 3D scanner from an open source FabLab project was constructed. In addition, the results for the analysis of the geometry of the point clouds obtained by using a low-cost laser scanner were presented. Also, some analysis of collecting data of different structures (made of various materials such as: glass, wood, paper, gum, plastic, plaster, ceramics, stoneware clay etc. and of different shapes: oval and similar to oval and prism shaped have been done. The article presents two methods used for analysis: the first one - visual (general comparison between the 3D model and the real object and the second one - comparative method (comparison between measurements on models and scanned objects using the mean error of a single sample of observations. The analysis showed, that the low-budget ground-based laser scanner FabScan has difficulties with collecting data of non-oval objects. Items built of glass painted black also caused problems for the scanner. In addition, the more details scanned object contains, the lower the accuracy of the collected point-cloud is. Nevertheless, the accuracy of collected data (using oval-straight shaped objects is satisfactory. The accuracy, in this case, fluctuates between ± 0,4 mm and ± 1,0 mm whereas when using more detailed objects or a rectangular shaped prism the accuracy is much more lower, between 2,9 mm and ± 9,0 mm. Finally, the publication presents the possibility (for the

  15. General beam cross-section analysis using a 3D finite element slice

    DEFF Research Database (Denmark)

    Couturier, Philippe; Krenk, Steen

    2014-01-01

    A formulation for analysis of general cross-section properties has been developed. This formulation is based on the stress-strain states in the classic six equilibrium modes of a beam by considering a finite thickness slice modelled by a single layer of 3D finite elements. The displacement...... an analytical solution is available. The paper also shows an application to wind turbine blade cross-sections and discusses the effect of the finite element discretization on the cross-section properties such as stiffness parameters and the location of the elastic and shear centers....

  16. 3D Seismic Flexure Analysis for Subsurface Fault Detection and Fracture Characterization

    Science.gov (United States)

    Di, Haibin; Gao, Dengliang

    2017-03-01

    Seismic flexure is a new geometric attribute with the potential of delineating subtle faults and fractures from three-dimensional (3D) seismic surveys, especially those overlooked by the popular discontinuity and curvature attributes. Although the concept of flexure and its related algorithms have been published in the literature, the attribute has not been sufficiently applied to subsurface fault detection and fracture characterization. This paper provides a comprehensive study of the flexure attribute, including its definition, computation, as well as geologic implications for evaluating the fundamental fracture properties that are essential to fracture characterization and network modeling in the subsurface, through applications to the fractured reservoir at Teapot Dome, Wyoming (USA). Specifically, flexure measures the third-order variation of the geometry of a seismic reflector and is dependent on the measuring direction in 3D space; among all possible directions, flexure is considered most useful when extracted perpendicular to the orientation of dominant deformation; and flexure offers new insights into qualitative/quantitative fracture characterization, with its magnitude indicating the intensity of faulting and fracturing, its azimuth defining the orientation of most-likely fracture trends, and its sign differentiating the sense of displacement of faults and fractures.

  17. 3D television theory and circuit analysis%3D电视的原理及电路解析

    Institute of Scientific and Technical Information of China (English)

    常成祥

    2012-01-01

    2009年12月,随着阿凡达的大热,消费者对3D的狂热在国际上掀起一轮3D热潮。在3D电影的促动下,3D市场已于2010年开始起飞。而且随着全球消费电子厂商陆续推出一批包括电视机、监视器、笔记本电脑、蓝光盘播放器、数码相机、摄像机、电子相框等3D相关产品进军家庭市场。据DisplaySearch的市场调研数据显示,2010年3D电视全球出货量达到420万台。2011年全球3D电视货量达2 340万台,2014年预计将出货达9 000万台。中国的3D电视产业发展备受业内外人士关注,我国不仅是全球最大的平板电视市场,更是全球最大的彩电制造基地。从平板电视到互联网电视再到3D电视,每一次技术升级,国内彩电企业总是紧跟而上。2010年3月,TCL、创维等企业开始推出3D电视;随后在9月份,海信推出了融合网络多媒体技术、3D显示技术的LED背光电视;康佳一举推出4大系列、20多款智能3D电视。文中主要阐述3D电视的原理及技术分类,并以康佳988系列3D电视为例,解析3D部分电路。%In 2009 December,with the avatar’s hit,consumers of 3D fever in the world set off a new upsurge of 3D.In 3D film to promote,the 3D market has been started in 2010 to take off.But as the global consumer electronics manufacturers have launched a group including televisions,monitors,notebook computer,the blue disc player,digital camera,video camera,digital photo frame and other 3D related products to enter the domestic market.According to the DisplaySearch market research data show,the 2010 3D TV global shipments reached 4 200 000.The 2011 global 3D TV volume amounted to 23 400 000.2014 is expected to ship90 000 000 China’s 3D TV industry producing get attention of people outside.our country is not only the world’s largest flat panel TV market,is the world’s largest color TV manufacturing base.From the flat panel TV to the Internet television and3D television,every time the

  18. Computer Tomography 3-D Imaging of the Metal Deformation Flow Path in Friction Stir Welding

    Science.gov (United States)

    Schneider, Judy; Beshears, Ronald; Nunes, Arthur C., Jr.

    2004-01-01

    In friction stir welding, a rotating threaded pin tool is inserted into a weld seam and literally stirs the edges of the seam together. This solid-state technique has been successfully used in the joining of materials that are difficult to fusion weld such as aluminum alloys. To determine optimal processing parameters for producing a defect free weld, a better understanding of the resulting metal deformation flow path is required. Marker studies are the principal method of studying the metal deformation flow path around the FSW pin tool. In our study, we have used computed tomography (CT) scans to reveal the flow pattern of a lead wire embedded in a FSW weld seam. At the welding temperature of aluminum, the lead becomes molten and thus tracks the aluminum deformation flow paths in a unique 3-dimensional manner. CT scanning is a convenient and comprehensive way of collecting and displaying tracer data. It marks an advance over previous more tedious and ambiguous radiographic/metallographic data collection methods.

  19. Scanning laser optical computed tomography system for large volume 3D dosimetry

    Science.gov (United States)

    Dekker, Kurtis H.; Battista, Jerry J.; Jordan, Kevin J.

    2017-04-01

    Stray light causes artifacts in optical computed tomography (CT) that negatively affect the accuracy of radiation dosimetry in gels or solids. Scatter effects are exacerbated by a large dosimeter volume, which is desirable for direct verification of modern radiotherapy treatment plans such as multiple-isocenter radiosurgery. The goal in this study was to design and characterize an optical CT system that achieves high accuracy primary transmission measurements through effective stray light rejection, while maintaining sufficient scan speed for practical application. We present an optical imaging platform that uses a galvanometer mirror for horizontal scanning, and a translation stage for vertical movement of a laser beam and small area detector for minimal stray light production and acceptance. This is coupled with a custom lens-shaped optical CT aquarium for parallel ray sampling of projections. The scanner images 15 cm diameter, 12 cm height cylindrical volumes at 0.33 mm resolution in approximately 30 min. Attenuation coefficients reconstructed from CT scans agreed with independent cuvette measurements within 2% for both absorbing and scattering solutions as well as small 1.25 cm diameter absorbing phantoms placed within a large, scattering medium that mimics gel. Excellent linearity between the optical CT scanner and the independent measurement was observed for solutions with between 90% and 2% transmission. These results indicate that the scanner should achieve highly accurate dosimetry of large volume dosimeters in a reasonable timeframe for clinical application to radiotherapy dose verification procedures.

  20. Scanning laser optical computed tomography system for large volume 3D dosimetry.

    Science.gov (United States)

    Dekker, Kurtis H; Battista, Jerry J; Jordan, Kevin J

    2017-04-07

    Stray light causes artifacts in optical computed tomography (CT) that negatively affect the accuracy of radiation dosimetry in gels or solids. Scatter effects are exacerbated by a large dosimeter volume, which is desirable for direct verification of modern radiotherapy treatment plans such as multiple-isocenter radiosurgery. The goal in this study was to design and characterize an optical CT system that achieves high accuracy primary transmission measurements through effective stray light rejection, while maintaining sufficient scan speed for practical application. We present an optical imaging platform that uses a galvanometer mirror for horizontal scanning, and a translation stage for vertical movement of a laser beam and small area detector for minimal stray light production and acceptance. This is coupled with a custom lens-shaped optical CT aquarium for parallel ray sampling of projections. The scanner images 15 cm diameter, 12 cm height cylindrical volumes at 0.33 mm resolution in approximately 30 min. Attenuation coefficients reconstructed from CT scans agreed with independent cuvette measurements within 2% for both absorbing and scattering solutions as well as small 1.25 cm diameter absorbing phantoms placed within a large, scattering medium that mimics gel. Excellent linearity between the optical CT scanner and the independent measurement was observed for solutions with between 90% and 2% transmission. These results indicate that the scanner should achieve highly accurate dosimetry of large volume dosimeters in a reasonable timeframe for clinical application to radiotherapy dose verification procedures.

  1. Effects of Electrode Position on Spatiotemporal Auditory Nerve Fiber Responses: A 3D Computational Model Study

    Directory of Open Access Journals (Sweden)

    Soojin Kang

    2015-01-01

    Full Text Available A cochlear implant (CI is an auditory prosthesis that enables hearing by providing electrical stimuli through an electrode array. It has been previously established that the electrode position can influence CI performance. Thus, electrode position should be considered in order to achieve better CI results. This paper describes how the electrode position influences the auditory nerve fiber (ANF response to either a single pulse or low- (250 pulses/s and high-rate (5,000 pulses/s pulse-trains using a computational model. The field potential in the cochlea was calculated using a three-dimensional finite-element model, and the ANF response was simulated using a biophysical ANF model. The effects were evaluated in terms of the dynamic range, stochasticity, and spike excitation pattern. The relative spread, threshold, jitter, and initiated node were analyzed for single-pulse response; and the dynamic range, threshold, initiated node, and interspike interval were analyzed for pulse-train stimuli responses. Electrode position was found to significantly affect the spatiotemporal pattern of the ANF response, and this effect was significantly dependent on the stimulus rate. We believe that these modeling results can provide guidance regarding perimodiolar and lateral insertion of CIs in clinical settings and help understand CI performance.

  2. 3D Simulation of Storm Surge Disaster Based on Scenario Analysis

    Institute of Scientific and Technical Information of China (English)

    王晓玲; 孙小沛; 张胜利; 孙蕊蕊; 李瑞金; 朱泽彪

    2016-01-01

    The occurrence of storm surge disaster is often accompanied with floodplain, overflow, dike breach and other complex phenomena, while current studies on storm surge flooding are more concentrated on the 1D/2D numerical simulation of single disaster scenario (floodplain, overflow or dike breach), ignoring the composite ef-fects of various phenomena. Therefore, considering the uncertainty in the disaster process of storm surge, scenario analysis was firstly proposed to identify the composite disaster scenario including multiple phenomena by analyzing key driving forces, building scenario matrix and deducing situation logic. Secondly, by combining the advantages of k-ωand k-εmodels in the wall treatment, a shear stress transmission k-ωmodel coupled with VOF was proposed to simulate the 3D flood routing for storm surge disaster. Thirdly, risk degree was introduced to make the risk analysis of storm surge disaster. Finally, based on the scenario analysis, four scenarios with different storm surge intensity (100-year and 200-year frequency) were identified in Tianjin Binhai New Area. Then, 3D numerical simulation and risk map were made for the case.

  3. Molecular field analysis and 3D-quantitative structure-activity relationship study (MFA 3D-QSAR) unveil novel features of bile acid recognition at TGR5.

    Science.gov (United States)

    Macchiarulo, Antonio; Gioiello, Antimo; Thomas, Charles; Massarotti, Alberto; Nuti, Roberto; Rosatelli, Emiliano; Sabbatini, Paola; Schoonjans, Kristina; Auwerx, Johan; Pellicciari, Roberto

    2008-09-01

    Bile acids regulate nongenomic actions through the activation of TGR5, a membrane receptor that is G protein-coupled to the induction of adenylate cyclase. In this work, a training set of 43 bile acid derivatives is used to develop a molecular interaction field analysis (MFA) and a 3D-quantitative structure-activity relationship study (3D-QSAR) of TGR5 agonists. The predictive ability of the resulting model is evaluated using an external set of compounds with known TGR5 activity, and six bile acid derivatives whose unknown TGR5 activity is herein assessed with in vitro luciferase assay of cAMP formation. The results show a good predictive model and indicate a statistically relevant degree of correlation between the TGR5 activity and the molecular interaction fields produced by discrete positions of the bile acid scaffold. This information is instrumental to extend on a quantitative basis the current structure-activity relationships of bile acids as TGR5 modulators and will be fruitful to design new potent and selective agonists of the receptor.

  4. Voxelization Algorithms for Geospatial Applications: Computational methods for voxelating spatial datasets of 3D city models containing 3D surface, curve and point data models

    NARCIS (Netherlands)

    Nourian Ghadikolaee, P.; Goncalves, R.; Zlatanova, S.; Arroyo Ohori, G.A.K.; Vu Vo, A.

    2016-01-01

    Voxel representations have been used for years in scientific computation and medical imaging. The main focus of our research is to provide easy access to methods for making large-scale voxel models of built environment for environmental modelling studies while ensuring they are spatially correct, me

  5. 3D imaging of the Corinth rift from a new passive seismic tomography and receiver function analysis

    Science.gov (United States)

    Godano, Maxime; Gesret, Alexandrine; Noble, Mark; Lyon-Caen, Hélène; Gautier, Stéphanie; Deschamps, Anne

    2016-04-01

    The Corinth Rift is the most seismically active zone in Europe. The area is characterized by very localized NS extension at a rate of ~ 1.5cm/year, the occurrence of frequent and intensive microseismic crises and occasional moderate to large earthquakes like in 1995 (Mw=6.1). Since the year 2000, the Corinth Rift Laboratory (CRL, http://crlab.eu) consisting in a multidisciplinary natural observatory, aims at understanding the mechanics of faulting and earthquake nucleation in the Rift. Recent studies have improved our view about fault geometry and mechanics within CRL, but there is still a critical need for a better knowledge of the structure at depth both for the accuracy of earthquake locations and for mechanical interpretation of the seismicity. In this project, we aim to analyze the complete seismological database (13 years of recordings) of CRL by using recently developed methodologies of structural imaging, in order to determine at the same time and with high resolution, the local 3D structure and the earthquake locations. We perform an iterative joint determination of 3D velocity model and earthquake coordinates. In a first step, P and S velocity models are determined using first arrival time tomography method proposed by Taillandier et al. (2009). It consists in the minimization of the cost function between observed and theoretical arrival times which is achieved by the steepest descent method (e.g. Tarantola 1987). This latter requires computing the gradient of the cost function by using the adjoint state method (Chavent 1974). In a second step, earthquakes are located in the new velocity model with a non-linear inversion method based on a Bayesian formulation (Gesret et al. 2015). Step 1 and 2 are repeated until the cost function no longer decreases. We present preliminary results consisting in: (1) the adjustement of a 1D velocity model that is used as initial model of the 3D tomography and (2) a first attempt of the joint determination of 3D velocity

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

    Science.gov (United States)

    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).

  7. The usefulness of 3D quantitative analysis with using MRI for measuring osteonecrosis of the femoral head

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ji Young; Lee, Sun Wha [Ewha Womans University College of Medicine, Seoul (Korea, Republic of); Park, Youn Soo [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2006-11-15

    We wanted to evaluate the usefulness of MRI 3D quantitative analysis for measuring osteonecrosis of the femoral head in comparison with MRI 2D quantitative analysis and quantitative analysis of the specimen. For 3 months at our hospital, 14 femoral head specimens with osteonecrosis were obtained after total hip arthroplasty. The patients preoperative MRIs were retrospectively reviewed for quantitative analysis of the size of the necrosis. Each necrotic fraction of the femoral head was measured by 2D quantitative analysis with using mid-coronal and mid-sagittal MRIs, and by 3D quantitative analysis with using serial continuous coronal MRIs and 3D reconstruction software. The necrotic fraction of the specimen was physically measured by the fluid displacement method. The necrotic fraction according to MRI 2D or 3D quantitative analysis was compared with that of the specimen by using Spearman's correlation test. On the correlative analysis, the necrotic fraction by MRI 2D quantitative analysis and quantitative analysis of the specimen showed moderate correlation (r = 0.657); on the other hand, the necrotic fraction by MRI 3D quantitative analysis and quantitative analysis of the specimen demonstrated a strong correlation (r = 0.952) ({rho} < 0.05). MRI 3D quantitative analysis was more accurate than 2D quantitative analysis using MRI for measuring osteonecrosis of the femoral head. Therefore, it may be useful for predicting the clinical outcome and deciding the proper treatment option.

  8. Linearized FUN3D for Rapid Aeroelastic and Aeroservoelastic Design and Analysis Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall objective of this Phase I project is to develop a hybrid approach in FUN3D, referred herein to as the Linearized FUN3D, for rapid aeroelastic and...

  9. Corotational formulation for 3d solids. An analysis of geometrically nonlinear foam deformation

    CERN Document Server

    Kaczmarczyk, Łukasz; Pearce, Chris J

    2011-01-01

    This paper presents theory for the Lagrange co-rotational (CR) formulation of finite elements in the geometrically nonlinear analysis of 3D structures. In this paper strains are assumed to be small while the magnitude of rotations from the reference configuration is not restricted. A new best fit rotator and consistent spin filter are derived. Lagrange CR formulation is applied with Hybrid Trefftz Stress elements, although presented methodology can be applied to arbitrary problem formulation and discretization technique, f.e. finite volume methods and lattice models, discreet element methods. Efficiency of CR formulation can be utilized in post-buckling stability analysis, damage and fracture mechanics, modelling of dynamic fragmentation of bodies made from quasi-brittle materials, solid fluid interactions and analysis of post-stressed structures, discreet body dynamics.

  10. Segmentation and tracking of adherens junctions in 3D for the analysis of epithelial tissue morphogenesis.

    Science.gov (United States)

    Cilla, Rodrigo; Mechery, Vinodh; Hernandez de Madrid, Beatriz; Del Signore, Steven; Dotu, Ivan; Hatini, Victor

    2015-04-01

    Epithelial morphogenesis generates the shape of tissues, organs and embryos and is fundamental for their proper function. It is a dynamic process that occurs at multiple spatial scales from macromolecular dynamics, to cell deformations, mitosis and apoptosis, to coordinated cell rearrangements that lead to global changes of tissue shape. Using time lapse imaging, it is possible to observe these events at a system level. However, to investigate morphogenetic events it is necessary to develop computational tools to extract quantitative information from the time lapse data. Toward this goal, we developed an image-based computational pipeline to preprocess, segment and track epithelial cells in 4D confocal microscopy data. The computational pipeline we developed, for the first time, detects the adherens junctions of epithelial cells in 3D, without the need to first detect cell nuclei. We accentuate and detect cell outlines in a series of steps, symbolically describe the cells and their connectivity, and employ this information to track the cells. We validated the performance of the pipeline for its ability to detect vertices and cell-cell contacts, track cells, and identify mitosis and apoptosis in surface epithelia of Drosophila imaginal discs. We demonstrate the utility of the pipeline to extract key quantitative features of cell behavior with which to elucidate the dynamics and biomechanical control of epithelial tissue morphogenesis. We have made our methods and data available as an open-source multiplatform software tool called TTT (http://github.com/morganrcu/TTT).

  11. Effects of computing parameters and measurement locations on the estimation of 3D NPS in non-stationary MDCT images.

    Science.gov (United States)

    Miéville, Frédéric A; Bolard, Gregory; Bulling, Shelley; Gudinchet, François; Bochud, François O; Verdun, François R

    2013-11-01

    The goal of this study was to investigate the impact of computing parameters and the location of volumes of interest (VOI) on the calculation of 3D noise power spectrum (NPS) in order to determine an optimal set of computing parameters and propose a robust method for evaluating the noise properties of imaging systems. Noise stationarity in noise volumes acquired with a water phantom on a 128-MDCT and a 320-MDCT scanner were analyzed in the spatial domain in order to define locally stationary VOIs. The influence of the computing parameters in the 3D NPS measurement: the sampling distances bx,y,z and the VOI lengths Lx,y,z, the number of VOIs NVOI and the structured noise were investigated to minimize measurement errors. The effect of the VOI locations on the NPS was also investigated. Results showed that the noise (standard deviation) varies more in the r-direction (phantom radius) than z-direction plane. A 25 × 25 × 40 mm(3) VOI associated with DFOV = 200 mm (Lx,y,z = 64, bx,y = 0.391 mm with 512 × 512 matrix) and a first-order detrending method to reduce structured noise led to an accurate NPS estimation. NPS estimated from off centered small VOIs had a directional dependency contrary to NPS obtained from large VOIs located in the center of the volume or from small VOIs located on a concentric circle. This showed that the VOI size and location play a major role in the determination of NPS when images are not stationary. This study emphasizes the need for consistent measurement methods to assess and compare image quality in CT.

  12. Analysis of Impact of 3D Printing Technology on Traditional Manufacturing Technology

    Science.gov (United States)

    Wu, Niyan; Chen, Qi; Liao, Linzhi; Wang, Xin

    With quiet rise of 3D printing technology in automobile, aerospace, industry, medical treatment and other fields, many insiders hold different opinions on its development. This paper objectively analyzes impact of 3D printing technology on mold making technology and puts forward the idea of fusion and complementation of 3D printing technology and mold making technology through comparing advantages and disadvantages of 3D printing mold and traditional mold making technology.

  13. 3D finite element model of the diabetic neuropathic foot: a gait analysis driven approach.

    Science.gov (United States)

    Guiotto, Annamaria; Sawacha, Zimi; Guarneri, Gabriella; Avogaro, Angelo; Cobelli, Claudio

    2014-09-22

    Diabetic foot is an invalidating complication of diabetes that can lead to foot ulcers. Three-dimensional (3D) finite element analysis (FEA) allows characterizing the loads developed in the different anatomical structures of the foot in dynamic conditions. The aim of this study was to develop a subject specific 3D foot FE model (FEM) of a diabetic neuropathic (DNS) and a healthy (HS) subject, whose subject specificity can be found in term of foot geometry and boundary conditions. Kinematics, kinetics and plantar pressure (PP) data were extracted from the gait analysis trials of the two subjects with this purpose. The FEM were developed segmenting bones, cartilage and skin from MRI and drawing a horizontal plate as ground support. Materials properties were adopted from previous literature. FE simulations were run with the kinematics and kinetics data of four different phases of the stance phase of gait (heel strike, loading response, midstance and push off). FEMs were then driven by group gait data of 10 neuropathic and 10 healthy subjects. Model validation focused on agreement between FEM-simulated and experimental PP. The peak values and the total distribution of the pressures were compared for this purpose. Results showed that the models were less robust when driven from group data and underestimated the PP in each foot subarea. In particular in the case of the neuropathic subject's model the mean errors between experimental and simulated data were around the 20% of the peak values. This knowledge is crucial in understanding the aetiology of diabetic foot.

  14. Shape Analysis of 3D Head Scan Data for U.S. Respirator Users

    Science.gov (United States)

    Zhuang, Ziqing; Slice, DennisE; Benson, Stacey; Lynch, Stephanie; Viscusi, DennisJ

    2010-12-01

    In 2003, the National Institute for Occupational Safety and Health (NIOSH) conducted a head-and-face anthropometric survey of diverse, civilian respirator users. Of the 3,997 subjects measured using traditional anthropometric techniques, surface scans and 26 three-dimensional (3D) landmark locations were collected for 947 subjects. The objective of this study was to report the size and shape variation of the survey participants using the 3D data. Generalized Procrustes Analysis (GPA) was conducted to standardize configurations of landmarks associated with individuals into a common coordinate system. The superimposed coordinates for each individual were used as commensurate variables that describe individual shape and were analyzed using Principal Component Analysis (PCA) to identify population variation. The first four principal components (PC) account for 49% of the total sample variation. The first PC indicates that overall size is an important component of facial variability. The second PC accounts for long and narrow or short and wide faces. Longer narrow orbits versus shorter wider orbits can be described by PC3, and PC4 represents variation in the degree of ortho/prognathism. Geometric Morphometrics provides a detailed and interpretable assessment of morphological variation that may be useful in assessing respirators and devising new test and certification standards.

  15. Shape Analysis of 3D Head Scan Data for U.S. Respirator Users

    Directory of Open Access Journals (Sweden)

    Slice DennisE

    2010-01-01

    Full Text Available In 2003, the National Institute for Occupational Safety and Health (NIOSH conducted a head-and-face anthropometric survey of diverse, civilian respirator users. Of the 3,997 subjects measured using traditional anthropometric techniques, surface scans and 26 three-dimensional (3D landmark locations were collected for 947 subjects. The objective of this study was to report the size and shape variation of the survey participants using the 3D data. Generalized Procrustes Analysis (GPA was conducted to standardize configurations of landmarks associated with individuals into a common coordinate system. The superimposed coordinates for each individual were used as commensurate variables that describe individual shape and were analyzed using Principal Component Analysis (PCA to identify population variation. The first four principal components (PC account for 49% of the total sample variation. The first PC indicates that overall size is an important component of facial variability. The second PC accounts for long and narrow or short and wide faces. Longer narrow orbits versus shorter wider orbits can be described by PC3, and PC4 represents variation in the degree of ortho/prognathism. Geometric Morphometrics provides a detailed and interpretable assessment of morphological variation that may be useful in assessing respirators and devising new test and certification standards.

  16. [Application of PARAFAC method and 3-D fluorescence spectra in petroleum pollutant measurement and analysis].

    Science.gov (United States)

    Pan, Zhao; Wang, Yu-tian; Shao, Xiao-qing; Wu, Xi-jun; Yang, Li-li

    2012-03-01

    A method for identification and concentration measurement of petroleum pollutant by combining three-dimensional (3-D) fluorescence spectra with parallel factor analysis (PARAFAC) was proposed. The main emphasis of research was the measurement of coexisting different kinds of petroleum. The CCl4 solutions of a 0# diesel sample, a 97# gasoline sample, and a kerosene sample were used as measurement objects. The condition of multiple petroleum coexistence was simulated by petroleum solutions with different mixed ratios. The character of PARAFAC in complex mixture coexisting system analysis was studied. The spectra of three kinds of solutions and the spectra of gasoline-diesel mixed samples, diesel-kerosene mixed samples, and gas oline-diesel mixed with small counts of kerosene interference samples were analyzed respectively. The core consistency diagnostic method and residual sum of squares method were applied to calculate the number of factors in PARAFAC. In gasoline-diesel experiment, gasoline or diesel can be identified and measured as a whole respectively by 2-factors parallel factors analysis. In diesel-kerosene experiment, 2-factors parallel factors analysis can only obtain the characters of diesel, and the 3rd factor is needed to separate the kerosene spectral character from the mixture spectrum. When small counts of kerosene exist in gasoline-diesel solution, gasoline and diesel still can be identified and measured as principal components by a 2-factors parallel factor analysis, and the effect of interference on qualitative analysis is not significant. The experiment verified that the PARAFAC method can obtain characteristic spectrum of each kind of petroleum, and the concentration of petroleum in solutions can be predicted simultaneously, with recoveries shown in the paper. The results showed the possibility of petroleum pollutant identification and concentration measurement based on the 3-D fluorescence spectra and PARAFAC.

  17. A computer-assisted 3D model for analyzing the aggregation of tumorigenic cells reveals specialized behaviors and unique cell types that facilitate aggregate coalescence.

    Directory of Open Access Journals (Sweden)

    Amanda Scherer

    Full Text Available We have developed a 4D computer-assisted reconstruction and motion analysis system, J3D-DIAS 4.1, and applied it to the reconstruction and motion analysis of tumorigenic cells in a 3D matrix. The system is unique in that it is fast, high-resolution, acquires optical sections using DIC microscopy (hence there is no associated photoxicity, and is capable of long-term 4D reconstruction. Specifically, a z-series at 5 μm increments can be acquired in less than a minute on tissue samples embedded in a 1.5 mm thick 3D Matrigel matrix. Reconstruction can be repeated at intervals as short as every minute and continued for 30 days or longer. Images are converted to mathematical representations from which quantitative parameters can be derived. Application of this system to cancer cells from established lines and fresh tumor tissue has revealed unique behaviors and cell types not present in non-tumorigenic lines. We report here that cells from tumorigenic lines and tumors undergo rapid coalescence in 3D, mediated by specific cell types that we have named "facilitators" and "probes." A third cell type, the "dervish", is capable of rapid movement through the gel and does not adhere to it. These cell types have never before been described. Our data suggest that tumorigenesis in vitro is a developmental process involving coalescence facilitated by specialized cells that culminates in large hollow spheres with complex architecture. The unique effects of select monoclonal antibodies on these processes demonstrate the usefulness of the model for analyzing the mechanisms of anti-cancer drugs.

  18. Mechanical analysis of single myocyte contraction in a 3-D elastic matrix.

    Directory of Open Access Journals (Sweden)

    John Shaw

    Full Text Available BACKGROUND: Cardiac myocytes experience mechanical stress during each heartbeat. Excessive mechanical stresses under pathological conditions cause functional and structural remodeling that lead to heart diseases, yet the precise mechanisms are still incompletely understood. To study the cellular and molecular level mechanotransduction mechanisms, we developed a new 'cell-in-gel' experimental system to exert multiaxial (3-D stresses on a single myocyte during active contraction. METHODS: Isolated myocytes are embedded in an elastic hydrogel to simulate the mechanical environment in myocardium (afterload. When electrically stimulated, the in-gel myocyte contracts while the matrix resists shortening and broadening of the cell, exerting normal and shear stresses on the cell. Here we provide a mechanical analysis, based on the Eshelby inclusion problem, of the 3-D strain and stress inside and outside the single myocyte during contraction in an elastic matrix. RESULTS: (1 The fractional shortening of the myocyte depends on the cell's geometric dimensions and the relative stiffness of the cell to the gel. A slender or softer cell has less fractional shortening. A myocyte of typical dimensions embedded in a gel of similar elastic stiffness can contract only 20% of its load-free value. (2 The longitudinal stress inside the cell is about 15 times the transverse stress level. (3 The traction on the cell surface is highly non-uniform, with a maximum near its ends, showing 'hot spots' at the location of intercalated disks. (4 The mechanical energy expenditure of the myocyte increases with the matrix stiffness in a monotonic and nonlinear manner. CONCLUSION: Our mechanical analyses provide analytic solutions that readily lend themselves to parametric studies. The resulting 3-D mapping of the strain and stress states serve to analyze and interpret ongoing cell-in-gel experiments, and the mathematical model provides an essential tool to decipher and quantify

  19. Robust object tracking techniques for vision-based 3D motion analysis applications

    Science.gov (United States)

    Knyaz, Vladimir A.; Zheltov, Sergey Y.; Vishnyakov, Boris V.

    2016-04-01

    Automated and accurate spatial motion capturing of an object is necessary for a wide variety of applications including industry and science, virtual reality and movie, medicine and sports. For the most part of applications a reliability and an accuracy of the data obtained as well as convenience for a user are the main characteristics defining the quality of the motion capture system. Among the existing systems for 3D data acquisition, based on different physical principles (accelerometry, magnetometry, time-of-flight, vision-based), optical motion capture systems have a set of advantages such as high speed of acquisition, potential for high accuracy and automation based on advanced image processing algorithms. For vision-based motion capture accurate and robust object features detecting and tracking through the video sequence are the key elements along with a level of automation of capturing process. So for providing high accuracy of obtained spatial data the developed vision-based motion capture system "Mosca" is based on photogrammetric principles of 3D measurements and supports high speed image acquisition in synchronized mode. It includes from 2 to 4 technical vision cameras for capturing video sequences of object motion. The original camera calibration and external orientation procedures provide the basis for high accuracy of 3D measurements. A set of algorithms as for detecting, identifying and tracking of similar targets, so for marker-less object motion capture is developed and tested. The results of algorithms' evaluation show high robustness and high reliability for various motion analysis tasks in technical and biomechanics applications.

  20. Development and validation of technique for in-vivo 3D analysis of cranial bone graft survival

    Science.gov (United States)

    Bernstein, Mark P.; Caldwell, Curtis B.; Antonyshyn, Oleh M.; Ma, Karen; Cooper, Perry W.; Ehrlich, Lisa E.

    1997-05-01

    Bone autografts are routinely employed in the reconstruction of facial deformities resulting from trauma, tumor ablation or congenital malformations. The combined use of post- operative 3D CT and SPECT imaging provides a means for quantitative in vivo evaluation of bone graft volume and osteoblastic activity. The specific objectives of this study were: (1) Determine the reliability and accuracy of interactive computer-assisted analysis of bone graft volumes based on 3D CT scans; (2) Determine the error in CT/SPECT multimodality image registration; (3) Determine the error in SPECT/SPECT image registration; and (4) Determine the reliability and accuracy of CT-guided SPECT uptake measurements in cranial bone grafts. Five human cadaver heads served as anthropomorphic models for all experiments. Four cranial defects were created in each specimen with inlay and onlay split skull bone grafts and reconstructed to skull and malar recipient sites. To acquire all images, each specimen was CT scanned and coated with Technetium doped paint. For purposes of validation, skulls were landmarked with 1/16-inch ball-bearings and Indium. This study provides a new technique relating anatomy and physiology for the analysis of cranial bone graft survival.

  1. 3D geometry analysis of the medial meniscus--a statistical shape modeling approach.

    Science.gov (United States)

    Vrancken, A C T; Crijns, S P M; Ploegmakers, M J M; O'Kane, C; van Tienen, T G; Janssen, D; Buma, P; Verdonschot, N

    2014-10-01

    The geometry-dependent functioning of the meniscus indicates that detailed knowledge on 3D meniscus geometry and its inter-subject variation is essential to design well functioning anatomically shaped meniscus replacements. Therefore, the aim of this study was to quantify 3D meniscus geometry and to determine whether variation in medial meniscus geometry is size- or shape-driven. Also we performed a cluster analysis to identify distinct morphological groups of medial menisci and assessed whether meniscal geometry is gender-dependent. A statistical shape model was created, containing the meniscus geometries of 35 subjects (20 females, 15 males) that were obtained from MR images. A principal component analysis was performed to determine the most important modes of geometry variation and the characteristic changes per principal component were evaluated. Each meniscus from the original dataset was then reconstructed as a linear combination of principal components. This allowed the comparison of male and female menisci, and a cluster analysis to determine distinct morphological meniscus groups. Of the variation in medial meniscus geometry, 53.8% was found to be due to primarily size-related differences and 29.6% due to shape differences. Shape changes were most prominent in the cross-sectional plane, rather than in the transverse plane. Significant differences between male and female menisci were only found for principal component 1, which predominantly reflected size differences. The cluster analysis resulted in four clusters, yet these clusters represented two statistically different meniscal shapes, as differences between cluster 1, 2 and 4 were only present for principal component 1. This study illustrates that differences in meniscal geometry cannot be explained by scaling only, but that different meniscal shapes can be distinguished. Functional analysis, e.g. through finite element modeling, is required to assess whether these distinct shapes actually influence

  2. Nonlinear coupling analysis of coal seam floor during mining based on FLAC3D

    Institute of Scientific and Technical Information of China (English)

    YAO Duo-xi; XU Ji-ying; LU Hai-feng

    2011-01-01

    Based on the hydro-geological conditions of 1028 mining face in Suntuan Coal Mine, mining seepage strain mechanism of seam floor was simulated by a nonlinear coupling method, which applied fluid-solid coupling analysis module of FLAC3D. The results indicate that the permeability coefficient of adjoining rock changes a lot due to mining. The maximum value reaches 1 379.9 times to the original value, where it is at immediate roof of the mined-out area. According to the analysis on the seepage field, mining does not destroy water resistance of the floor aquiclude. The mining fissure does not conduct lime-stone aquifer, and it is less likely to form damage. The plastic zone does not exactly correspond to the seepage area, and the scope of the altered seepage area is much larger than the plastic zone.

  3. 3D-QSAR Investigation of Synthetic Antioxidant Chromone Derivatives by Molecular Field Analysis

    Directory of Open Access Journals (Sweden)

    Jiraporn Ungwitayatorn

    2008-02-01

    Full Text Available A series of 7-hydroxy, 8-hydroxy and 7,8-dihydroxy synthetic chromone derivatives was evaluated for their DPPH free radical scavenging activities. A training set of 30 synthetic chromone derivatives was subject to three-dimensional quantitative structure-activity relationship (3D-QSAR studies using molecular field analysis (MFA. The substitutional requirements for favorable antioxidant activity were investigated and a predictive model that could be used for the design of novel antioxidants was derived. Regression analysis was carried out using genetic partial least squares (G/PLS method. A highly predictive and statistically significant model was generated. The predictive ability of the developed model was assessed using a test set of 5 compounds (r2pred = 0.924. The analyzed MFA model demonstrated a good fit, having r2 value of 0.868 and crossvalidated coefficient r2cv value of 0.771.

  4. ANALYSIS OF SLAB EDGING BY A 3-D RIGID VISCO-PLASTIC FINITE ELEMENT METHOD

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    3-D rigid visco-plastic finite element method (FEM) is used in the analysis of metal forming processes, including strip and plate rolling, shape rolling, slab edging, special strip rolling. The shifted incomplete Cholesky decomposition of the stiffness matrix with the solution of the equations for velocity increment by the conjugate gradient method is combined. This technique, termed the shifted ICCG method, is then employed to solve the slab edging problem. The performance of this algorithm in terms of the number of iterations, friction variation, shifted parameter ( and the results of simulation for processing parameters are analysed. Numerical tests and application of this technique verify the efficiency and stability of the shifted ICCG method in the analysis of slab edging.

  5. 3D-QSAR studies on glycogen phosphorylase inhibitors by flexible comparative molecular field analysis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Canceling grids accommodating probes in comparative molecular field analysis (CoMFA), the idea of flexibleness is introduced into the CoMFA, and in combination with swarm intelligent algorithm which attempts to optimize distributions of diverse probes around drug molecules, a new 3D-QSAR method is proposed in this context as flexible comparative molecular field analysis (FCoMFA). In preliminary at-tempts to performing QSAR studies on 47 glycogen phosphorylase inhibitors, FCoMFA is employed and confirmed to be potent to exploring ligand-receptor interaction manners at active positions and thus to generating stable and predictable models. Simultaneously by an intuitive graphics regarding probe distribution patterns, impacts of different substituted groups on activities is also given an insight into.

  6. 3D-QSAR studies on glycogen phosphorylase inhibitors by flexible comparative molecular field analysis

    Institute of Scientific and Technical Information of China (English)

    ZHOU Peng; LI ZhiLiang

    2007-01-01

    Canceling grids accommodating probes in comparative molecular field analysis (CoMFA), the idea of flexibleness is introduced into the CoMFA, and in combination with swarm intelligent algorithm which attempts to optimize distributions of diverse probes around drug molecules, a new 3D-QSAR method is proposed in this context as flexible comparative molecular field analysis (FCoMFA). In preliminary attempts to performing QSAR studies on 47 glycogen phosphorylase inhibitors, FCoMFA is employed and confirmed to be potent to exploring ligand-receptor interaction manners at active positions and thus to generating stable and predictable models. Simultaneously by an intuitive graphics regarding probe distribution patterns, impacts of different substituted groups on activities is also given an insight into.

  7. Shakedown Analysis of 3-D Structures Using the Boundary Element Method Based on the Static Theorem

    Institute of Scientific and Technical Information of China (English)

    张晓峰; 刘应华; 岑章志

    2003-01-01

    The static shakedown theorem was reformulated for the boundary element method (BEM) rather than the finite element method with Melan's theorem, then used to develop a numerical solution procedure for shakedown analysis. The self-equilibrium stress field was constructed by a linear combination of several basis self-equilibrium stress fields with undetermined parameters. These basis self-equilibrium stress fields were expressed as elastic responses of the body to imposed permanent strains obtained using a 3-D BEM elastic-plastic incremental analysis. The lower bound for the shakedown load was obtained from a series of nonlinear mathematical programming problems solved using the Complex method. Numerical examples verified the precision of the present method.

  8. Computational Fluid Dynamic Analyses for the High-Lift Common Research Model Using the USM3D and FUN3D Flow Solvers

    Science.gov (United States)

    Rivers, Melissa; Hunter, Craig; Vatsa, Veer

    2017-01-01

    Two Navier-Stokes codes were used to compute flow over the High-Lift Common Research Model (HL-CRM) in preparation for a wind tunnel test to be performed at the NASA Langley Research Center 14-by-22-Foot Subsonic Tunnel in fiscal year 2018. Both flight and wind tunnel conditions were simulated by the two codes at set Mach numbers and Reynolds numbers over a full angle-of-attack range for three configurations: cruise, landing and takeoff. Force curves, drag polars and surface pressure contour comparisons are shown for the two codes. The lift and drag curves compare well for the cruise configuration up to 10deg angle of attack but not as well for the other two configurations. The drag polars compare reasonably well for all three configurations. The surface pressure contours compare well for some of the conditions modeled but not as well for others.

  9. Numerical study for the calculation of computer-generated hologram in color holographic 3D projection enabled by modified wavefront recording plane method

    Science.gov (United States)

    Chang, Chenliang; Qi, Yijun; Wu, Jun; Yuan, Caojin; Nie, Shouping; Xia, Jun

    2017-03-01

    A method of calculating computer-generated hologram (CGH) for color holographic 3D projection is proposed. A color 3D object is decomposed into red, green and blue components. For each color component, a virtual wavefront recording plane (WRP) is established which is nonuniformly sampled according to the depth map of the 3D object. The hologram of each color component is calculated from the nonuniform sampled WRP using the shifted Fresnel diffraction algorithm. Finally three holograms of RGB components are encoded into one single CGH based on the multiplexing encoding method. The computational cost of CGH generation is reduced by converting diffraction calculation from huge 3D voxels to three 2D planar images. Numerical experimental results show that the CGH generated by our method is capable to project zoomable color 3D object with clear quality.

  10. Trend Analysis for the Market and Application Development of 3D Printing

    Directory of Open Access Journals (Sweden)

    Chin-Ching Yeh

    2014-02-01

    Full Text Available In 2011, the Economist newspaper declared the advent of 3D printing, also known as Additive Manufacturing (AM, to herald the start of the Third Industrial Revolution. Chris Anderson, originator of the “long-tail theory”, not only authored Makers, a book on3D printing, but also co-founded 3D Robotics to realize his vision for the potential of 3D printing by applying his perspectives embedded in his book. Nevertheless, opposing viewpoints suggest that 3D printing may not be the game changer its proponents claim. The article explores the technical classification and market growth potential of 3D printing, and analyzes the main markets and countries as well as the application scope of 3D printing.

  11. Transient Thermal Analysis of 3-D Integrated Circuits Packages by the DGTD Method

    KAUST Repository

    Li, Ping

    2017-03-11

    Since accurate thermal analysis plays a critical role in the thermal design and management of the 3-D system-level integration, in this paper, a discontinuous Galerkin time-domain (DGTD) algorithm is proposed to achieve this purpose. Such as the parabolic partial differential equation (PDE), the transient thermal equation cannot be directly solved by the DGTD method. To address this issue, the heat flux, as an auxiliary variable, is introduced to reduce the Laplace operator to a divergence operator. The resulting PDE is hyperbolic, which can be further written into a conservative form. By properly choosing the definition of the numerical flux used for the information exchange between neighboring elements, the hyperbolic thermal PDE can be solved by the DGTD together with the auxiliary differential equation. The proposed algorithm is a kind of element-level domain decomposition method, which is suitable to deal with multiscale geometries in 3-D integrated systems. To verify the accuracy and robustness of the developed DGTD algorithm, several representative examples are benchmarked.

  12. Analysis of 3D Printed Diopside Scaffolds Properties for Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Tingting LIU

    2015-11-01

    Full Text Available Diopside exhibits favorable potential for bone repair on account of the good mechanical performance, bioactivity and biocompatibility. In this paper, diopside scaffolds with high pore interconnectivity were successfully fabricated by laser three-dimensional (3D printing. The microstructure and mechanical performance of the diopside scaffolds were studied. The experimental analysis indicated that diopside particles gradually fused together until a dense structure was built with an energy density increasing in the range between 2.4 and 4.8 J·mm-2. Meanwhile, compressive strength and fracture toughness increased gradually from 5.96 ± 0.88 MPa to 10.87 ± 0.55 MPa. However, mechanical properties decreased due to the appearance of voids when energy density were 5.4 and 6 J·mm-2. Simulated body fluid (SBF tests showed that apatite crystals formed on the diopside scaffolds surface, and the apatite crystals increased with soaking time. Cell culture tests indicated the scaffolds supported the adhesion and growth of MG-63 cells. The study suggested that diopside scaffolds fabricated by laser 3D printing are promising candidates for bone tissue engineering.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9845

  13. Promoting best practice design intent in 3D CAD for engineers through a task analysis

    Directory of Open Access Journals (Sweden)

    Keelin Leahy

    2013-01-01

    Full Text Available Assessment encompasses a range of methods and techniques. At the University of Limerick, Ireland, it is an affirmed obligation to facilitate timely and useful feedback for both formative (for learning and summative (of learning assessment. However, the effectiveness of this feedback has raised concern and has a wide-ranging review of research findings. This paper presents research findings to build a picture of the extent to which the impact of feedback as a constructivist paradigm of teaching and learning can promote best practice design intent in 3D CAD Modelling. The resulting data set, comprised of 114 higher education students, is used to discuss the impact of assessment and feedback, comparing semesters Spring 2011/12 and Spring 2012/13. The 2012/13 cohort received formative assessment feedback from a task analysis. This evidenced an upsurge in understanding in best practice design intent in 3D CAD parametric modelling, supported by an effect size of 0.534.

  14. Evolution of residual stress and crack morphologies during 3D FIB tomographic analysis of alumina.

    Science.gov (United States)

    Elfallagh, F; Inkson, B J

    2008-05-01

    Three-dimensional focused ion beam (FIB) tomography is increasingly being used for 3D characterization of microstructures in the 50 nm-20 microm range. FIB tomography is a destructive, invasive process, and microstructural changes may potentially occur during the analysis process. Here residual stress and crack morphologies in single-crystal sapphire samples have been concurrently analyzed using Cr3+ fluorescence spectroscopy and FIB tomography. Specifically, maps of surface residual stress have been obtained from optically polished single-crystal alumina [surface orientation (1 ī 0 2)], from FIB milled surface trenches, from Vickers micro-indentation sites (loads 50 g-300 g), and from Vickers micro-indentation sites during FIB serial sectioning. The residual stress maps clearly show that FIB sputtering generates residual stress changes. For the case of the Vickers micro-indentations, FIB sputtering causes significant changes in residual stress during the FIB tomographic serial sectioning. 3D reconstruction of the crack distribution around micro-indentation sites shows that the cracks observed are influenced by the location of the FIB milled surface trenches due to localized stress changes.

  15. Deterioration estimation of paintings by means of combined 3D and hyperspectral data analysis

    Science.gov (United States)

    Granero-Montagud, Luís.; Portalés, Cristina; Pastor-Carbonell, Begoña.; Ribes-Gómez, Emilio; Gutiérrez-Lucas, Antonio; Tornari, Vivi; Papadakis, Vassilis; Groves, Roger M.; Sirmacek, Beril; Bonazza, Alessandra; Ozga, Izabela; Vermeiren, Jan; van der Zanden, Koen; Föster, Matthias; Aswendt, Petra; Borreman, Albert; Ward, Jon D.; Cardoso, António; Aguiar, Luís.; Alves, Filipa; Ropret, Polonca; Luzón-Nogué, José María.; Dietz, Christian

    2013-05-01

    Deterioration of artwork, in particular paintings, can be produced by environmental factors such as temperature fluctuations, relative humidity variations, ultraviolet radiation and biological factors among others. The effects of these parameters produce changes in both the painting structure and chemical composition. While well established analytical methodologies, such as those based in Raman Spectroscopy and FTIR Spectroscopy require the extraction of a sample for its inspection, other approaches such as hyperspectral imaging and 3D scanning present advantages for in-situ, noninvasive analysis of artwork. In this paper we introduce a novel system and the related methodology to acquire process, generate and analyze 4D data of paintings. Our system is based on non-contact techniques and is used to develop analytical tools which extract rich 3D and hyperspectral maps of the objects, which are processed to obtain accurate quantitative estimations of the deterioration and degradation present in the piece of art. In particular, the construction of 4D data allows the identification of risk maps on the painting representation, which can allow the curators and restorers in the task of painting state evaluation and prioritize intervention actions.

  16. 3D Analysis of Porosity in a Ceramic Coating Using X-ray Microscopy

    Science.gov (United States)

    Klement, Uta; Ekberg, Johanna; Kelly, Stephen T.

    2017-02-01

    Suspension plasma spraying (SPS) is a new, innovative plasma spray technique using a feedstock consisting of fine powder particles suspended in a liquid. Using SPS, ceramic coatings with columnar microstructures have been produced which are used as topcoats in thermal barrier coatings. The microstructure contains a wide pore size range consisting of inter-columnar spacings, micro-pores and nano-pores. Hence, determination of total porosity and pore size distribution is a challenge. Here, x-ray microscopy (XRM) has been applied for describing the complex pore space of the coatings because of its capability to image the (local) porosity within the coating in 3D at a resolution down to 50 nm. The possibility to quantitatively segment the analyzed volume allows analysis of both open and closed porosity. For an yttria-stabilized zirconia coating with feathery microstructure, both open and closed porosity were determined and it could be revealed that 11% of the pore volumes (1.4% of the total volume) are closed pores. The analyzed volume was reconstructed to illustrate the distribution of open and closed pores in 3D. Moreover, pore widths and pore volumes were determined. The results on the complex pore space obtained by XRM are discussed in connection with other porosimetry techniques.

  17. 3D FE Analysis of RC Beams Externally Strengthened with SRG/SRP Systems

    Directory of Open Access Journals (Sweden)

    Francesco Bencardino

    2016-05-01

    Full Text Available The purpose of this study is to evaluate, through a nonlinear Finite Element (FE analysis, the structural behavior of Reinforced Concrete (RC beams externally strengthened by using Steel Reinforced Grout (SRG and Steel Reinforced Polymer (SRP systems. The parameters taken into account were the external strengthening configuration, with or without U-wrap end anchorages, as well as the strengthening materials. The numerical simulations were carried out by using a three-dimensional (3D FE model. The linear and nonlinear behavior of all materials was modeled by appropriate constitutive laws and the connection between concrete substrate and external reinforcing layer was simulated by means of cohesive surfaces with appropriate bond-slip laws. In order to overcome convergence difficulties, to simulate the quasi-static response of the strengthened RC beams, a dynamic approach was adopted. The numerical results in terms of load-displacement curves, failure modes, and load and strain values at critical stages were validated against some experimental data. As a result, the proposed 3D FE model can be used to predict the structural behavior up to ultimate stage of similar strengthened beams without carrying out experimental tests.

  18. 3D Finite Element Analysis of PWA-Oil Sand Terrain System Interaction

    Directory of Open Access Journals (Sweden)

    Y. Li

    2012-01-01

    Full Text Available A simulator for analyzing the interaction between the oil sand terrain and a pipe wagon articulating (PWA system has been developed in this paper. An elastic-plastic oil sand model was built based on the finite element analysis (FEA method and von Mises yield criterion using the Algor mechanical event simulation (MES software. The three-dimensional (3D distribution of the stress, strain, nodal displacement, and deformed shape of the oil sands was animated at an environmental temperature of 25°C. The 3D behavior of the oil sand terrain was investigated with different loading conditions. The effect of the load and contact area on the stress and nodal displacement was analyzed, respectively. The results indicate that both the max stress and max nodal displacement increase with the load varying from 0 to 3.6+7 N and decrease with the contact area varying from 2 to 10 m2. The method presented in this paper forms the basis for evaluating the bearing capacity of oil sand ground.

  19. In vivo analysis of physiological 3D blood flow of cerebral veins

    Energy Technology Data Exchange (ETDEWEB)

    Schuchardt, Florian; Schroeder, Laure; Baeuerle, Jochen; Harloff, Andreas [University Medical Centre, Department of Neurology, Freiburg (Germany); Anastasopoulos, Constantin [University Medical Center, Department of Neuropaediatrics and Muscle Disorders, Freiburg (Germany); University Medical Centre, Department of Neuroradiology, Freiburg (Germany); Markl, Michael [Northwestern University, Department of Radiology, Feinberg School of Medicine and McCormick School of Engineering, Chicago, IL (United States); Hennemuth, Anja; Drexl, Johann [Fraunhofer MEVIS, Bremen (Germany); Valdueza, Jose M. [Neurological Center, Segeberger Kliniken, Bad Segeberg (Germany); Mader, Irina [University Medical Centre, Department of Neuroradiology, Freiburg (Germany)

    2015-08-15

    To visualize and quantify physiological blood flow of intracranial veins in vivo using time-resolved, 3D phase-contrast MRI (4D flow MRI), and to test measurement accuracy. Fifteen healthy volunteers underwent repeated ECG-triggered 4D flow MRI (3 Tesla, 32-channel head coil). Intracranial venous blood flow was analysed using dedicated software allowing for blood flow visualization and quantification in analysis planes at the superior sagittal, straight, and transverse sinuses. MRI was evaluated for intra- and inter-observer agreement and scan-rescan reproducibility. Measurements of the transverse sinuses were compared with transcranial two-dimensional duplex ultrasound. Visualization of 3D blood flow within cerebral sinuses was feasible in 100 % and within at least one deep cerebral vein in 87 % of the volunteers. Blood flow velocity/volume increased along the superior sagittal sinus and was lower in the left compared to the right transverse sinus. Intra- and inter-observer reliability and reproducibility of blood flow velocity (mean difference 0.01/0.02/0.02 m/s) and volume (mean difference 0.0002/-0.0003/0.00003 l/s) were good to excellent. High/low velocities were more pronounced (8 % overestimation/9 % underestimation) in MRI compared to ultrasound. Four-dimensional flow MRI reliably visualizes and quantifies three-dimensional cerebral venous blood flow in vivo and is promising for studies in patients with sinus thrombosis and related diseases. (orig.)

  20. Steady-State VEP-Based Brain-Computer Interface Control in an Immersive 3D Gaming Environment

    Directory of Open Access Journals (Sweden)

    Burke R

    2005-01-01

    Full Text Available This paper presents the application of an effective EEG-based brain-computer interface design for binary control in a visually elaborate immersive 3D game. The BCI uses the steady-state visual evoked potential (SSVEP generated in response to phase-reversing checkerboard patterns. Two power-spectrum estimation methods were employed for feature extraction in a series of offline classification tests. Both methods were also implemented during real-time game play. The performance of the BCI was found to be robust to distracting visual stimulation in the game and relatively consistent across six subjects, with 41 of 48 games successfully completed. For the best performing feature extraction method, the average real-time control accuracy across subjects was 89%. The feasibility of obtaining reliable control in such a visually rich environment using SSVEPs is thus demonstrated and the impact of this result is discussed.