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Sample records for real time three-dimensional

  1. Real time three dimensional sensing system

    DOEpatents

    Gordon, Steven J.

    1996-01-01

    The invention is a three dimensional sensing system which utilizes two flexibly located cameras for receiving and recording visual information with respect to a sensed object illuminated by a series of light planes. Each pixel of each image is converted to a digital word and the words are grouped into stripes, each stripe comprising contiguous pixels. One pixel of each stripe in one image is selected and an epi-polar line of that point is drawn in the other image. The three dimensional coordinate of each selected point is determined by determining the point on said epi-polar line which also lies on a stripe in the second image and which is closest to a known light plane.

  2. Real time three dimensional sensing system

    DOEpatents

    Gordon, S.J.

    1996-12-31

    The invention is a three dimensional sensing system which utilizes two flexibly located cameras for receiving and recording visual information with respect to a sensed object illuminated by a series of light planes. Each pixel of each image is converted to a digital word and the words are grouped into stripes, each stripe comprising contiguous pixels. One pixel of each stripe in one image is selected and an epi-polar line of that point is drawn in the other image. The three dimensional coordinate of each selected point is determined by determining the point on said epi-polar line which also lies on a stripe in the second image and which is closest to a known light plane. 7 figs.

  3. Live/real time three-dimensional transesophageal echocardiography.

    PubMed

    Sudhakar, Selvin; Khairnar, Prakash; Nanda, Navin C

    2012-01-01

    Since the advent of matrix array transducer, three-dimensional transesophageal echocardiography has come to frequent clinical use. It has significantly enhanced the communication between the operators and cardiac imagers in the operating room as well as in the cardiac interventional labs. This article reviews the history, technological aspects, and the protocol for acquisition and processing of the data sets. It also discusses its advantages in various clinical scenarios, both in diagnostic and therapeutic situations. It highlights its limitations in the current form and prospects of future development. PMID:23186294

  4. The application of holography as a real-time three-dimensional motion picture camera

    NASA Technical Reports Server (NTRS)

    Kurtz, R. L.

    1973-01-01

    A historical introduction to holography is presented, as well as a basic description of sideband holography for stationary objects. A brief theoretical development of both time-dependent and time-independent holography is also provided, along with an analytical and intuitive discussion of a unique holographic arrangement which allows the resolution of front surface detail from an object moving at high speeds. As an application of such a system, a real-time three-dimensional motion picture camera system is discussed and the results of a recent demonstration of the world's first true three-dimensional motion picture are given.

  5. Large field of view real-time three-dimensional imaging for ports

    NASA Astrophysics Data System (ADS)

    Gao, Meijing; Wu, Weilong; Gu, Haihua; Bi, Weihong

    2011-06-01

    With the acceleration of globalization and regionalization of the world economy, port is playing an increasingly important role for that it is an international transportation hub port interface and the support of the international trade platform. How to effectively reduce labor costs, improve the working environment, stable productivity, reduce the production cuts caused by human intervention and improve the management of real-time monitoring of all the major ports has become a common issue faced. In order to achieve the automatically stacking and reclaiming process of Stacker-Reclaimer in the bulk material yard, the source of its control is expected to identify the stockpile in the bulk yard, including length, width, height, the starting address, destination address, as well as Three-dimensional shape of the stockpile, since in the operation process, stockpile changes the shape dynamically. As a result, the real-time three-dimensional shape and coordinate of piles should be achieved. Based on the existing Stacker-Reclaimer in Qinhuangdao Port coal, we study the large field of view real-time three-dimensional laser scanning imaging theory and technology. The overall system design to achieving the three-dimensional laser scanning image is presented. The working principle of the three-dimensional laser scanning imaging system is analysised. Moreover, the parameter designation, the technical parameters and the composition of the whole system are all given. The research of the thesis is also used for other large-scale three-dimensional modeling of piles and the volume computing. In a world, the method has wide application prospect.

  6. Real-time three-dimensional pickup and display system based on integral photography

    NASA Astrophysics Data System (ADS)

    Okano, Fumio; Arai, Jun; Hoshino, Haruo; Yuyama, Ichiro

    1998-12-01

    A real-time three-dimensional (3-D) pickup and display setup called a Real-time IP system is proposed. In this system, erected real images of an object are formed by a GRIN lens array as element images, and are directly shot by a television camera. The video signal of a group of element images is transmitted to display device that combines a liquid crystal panel display and a convex micro-lens array, producing a color 3-D image in real-time. Full-color and autostereoscopic 3-D images with full-parallax can be observed. We confirmed the possibility of the 3-D television system.

  7. Real-time three dimensional sonographic features of an early third trimester fetus with achondrogenesis.

    PubMed

    Wataganara, Tuangsit; Sutanthavibool, Anuwat; Limwongse, Chanin

    2006-10-01

    Generalized shortening of fetal long bones detected from prenatal sonographic examination usually raise a tentative diagnosis of skeletal dysplasia. Information obtained from grey-scale scan is frequently not sufficient to provide a definite diagnosis, and the images are not readily comprehensible for the parents-to-be. Lately, three-dimensional sonography has become increasing available in obstetric practice. The authors report here a rare case of fetal achondrogenesis, which is a lethal form of skeletal dysplasia, in a 30-week-old fetus using real-time three-dimensional ultrasound. The prenatal findings of fetal achondrogenesis from this technique were thoroughly described, along with postnatal radiography and autopsy results. Sonographic features from this imaging technique allow for an accurate diagnosis and better understanding of the parents. This facilitates the genetic counseling process, as well as the parental options for further care. PMID:17128855

  8. Incorporation of thermal shadows into real-time infrared three-dimensional image generation

    NASA Astrophysics Data System (ADS)

    Klein, Andreas; Nischwitz, Alfred; Schätz, Peter; Obermeier, Paul

    2014-05-01

    In the infrared spectrum, two contributions to shadows exist: one part is reflective shadows resulting from occlusion of instantly reflected infrared rays, and the other part is thermal (IR) shadows occurring through occlusion of irradiance in the past. The realization of thermal shadows requires a thermal balance calculation in four-dimensions (three-dimensional geometry in one-dimensional time), which is computationally expensive, and therefore mostly used for nonreal-time simulations. We present an approximation of thermal shadows resulting from the occlusion of direct rays from IR emitters. Our approach uses programmable graphics cards to achieve real-time frame rates in scenes with dynamic geometry.

  9. Real-time visual tracking of less textured three-dimensional objects on mobile platforms

    NASA Astrophysics Data System (ADS)

    Seo, Byung-Kuk; Park, Jungsik; Park, Hanhoon; Park, Jong-Il

    2012-12-01

    Natural feature-based approaches are still challenging for mobile applications (e.g., mobile augmented reality), because they are feasible only in limited environments such as highly textured and planar scenes/objects, and they need powerful mobile hardware for fast and reliable tracking. In many cases where conventional approaches are not effective, three-dimensional (3-D) knowledge of target scenes would be beneficial. We present a well-established framework for real-time visual tracking of less textured 3-D objects on mobile platforms. Our framework is based on model-based tracking that efficiently exploits partially known 3-D scene knowledge such as object models and a background's distinctive geometric or photometric knowledge. Moreover, we elaborate on implementation in order to make it suitable for real-time vision processing on mobile hardware. The performance of the framework is tested and evaluated on recent commercially available smartphones, and its feasibility is shown by real-time demonstrations.

  10. Real-time, interactive animation of deformable two- and three-dimensional objects

    DOEpatents

    Desbrun, Mathieu; Schroeder, Peter; Meyer, Mark; Barr, Alan H.

    2003-06-03

    A method of updating in real-time the locations and velocities of mass points of a two- or three-dimensional object represented by a mass-spring system. A modified implicit Euler integration scheme is employed to determine the updated locations and velocities. In an optional post-integration step, the updated locations are corrected to preserve angular momentum. A processor readable medium and a network server each tangibly embodying the method are also provided. A system comprising a processor in combination with the medium, and a system comprising the server in combination with a client for accessing the server over a computer network, are also provided.

  11. Demonstration of a large-size real-time full-color three-dimensional display.

    PubMed

    Sang, Xinzhu; Fan, Frank C; Jiang, C C; Choi, Sam; Dou, Wenhua; Yu, Chongxiu; Xu, Daxiong

    2009-12-15

    A large-size and full-color three-dimensional (3D) display system without the need for special eyeglasses is demonstrated. With a specially fabricated holographic functional screen with a size of 1.8x1.3 m(2), the system including optimally designed camera-projector arrays and a video server can display the fully continuous, natural 3D scene with more than 1 m image depth in real time. We explain the operating principle and present experimental results. PMID:20016619

  12. Real-time three-dimensional fingerprint acquisition via a new photometric stereo means

    NASA Astrophysics Data System (ADS)

    Xie, Wuyuan; Song, Zhan; Chung, Ronald

    2013-10-01

    A real-time means for three-dimensional (3-D) fingerprint acquisition is presented. The system is configured with only one camera and some white light-emitting diode lamps. The reconstruction is performed based on the principle of photometric stereo. In the algorithm, a two-layer Hanrahan-Krueger model is proposed to represent the finger surface reflectance property instead of the traditional Lambert model. By the proposed lighting direction calibration and the nonuniform lighting correction methods, surface normal at each image point can be accurately estimated by solving a nonlinear optimization problem. Finally, a linear normal transformation is implemented for the enhancement of 3-D models. The experiments are implemented with real finger and palm prints, and the results are also compared with traditional means to show its feasibility and improvement in the reconstruction accuracy.

  13. Three-dimensional dose evaluation system using real-time wind field information for nuclear accidents in Taiwan

    NASA Astrophysics Data System (ADS)

    Wu, Jay; Lu, Chung-Hsin; Chang, Shu-Jun; Yang, Yung-Muh; Chang, Bor-Jing; Teng, Jen-Hsin

    2006-09-01

    In Taiwan, the three operating nuclear power plants are all built along the coast over complex terrain. Dose estimates after a nuclear accident with releases of radioactive materials, therefore, cannot be accurately calculated using simple dispersion models. We developed a three-dimensional dose evaluation system, which incorporates real-time prognostic wind field information with three-dimensional numerical models to predict dose results. The proposed system consists of three models: a three-dimensional mesoscale atmospheric model (HOTMAC), a three-dimensional transport and diffusion model (RAPTAD), and a dose calculation model (DOSE). The whole-body dose and thyroid dose as well as dose rates can be rapidly estimated and displayed on the three-dimensional terrain model constructed by satellite images. The developed three-dimensional dose evaluation system could accurately forecast the dose results and has been used in the annual nuclear emergency response exercise to provide suggestions for protective measures.

  14. Real-time three-dimensional intracardiac echocardiography: an early single-center experience.

    PubMed

    Maini, Brijeshwar

    2015-01-01

    As interventional procedures in structural heart diseases are coming of age, there is a significant lag in the periinterventional imaging development for these procedures to become safe, expedient, accurate, and well tolerated by this patient population. Currently, transesophageal echocardiography (TEE), including real-time three-dimensional (RT-3D), has been used for monitoring and guidance for these procedures. Accurate identification of the pathology, its anatomy, and its relationship with the adjoining structures along with spatial resolution is of paramount importance for wire and catheter placement, device deployment, evaluation of the results, and any potential complications. Two-dimensional intracardiac echocardiography (ICE) has been used extensively for a variety of interventional procedures that undergo conscious sedation of monitored anesthesia. RT-3D ICE has recently become available; we describe our initial experience with this new imaging technology. PMID:25589706

  15. Real-time and three-dimensional MRI for diagnosis of pharyngoceles.

    PubMed

    Traser, Louisa; Spahn, Claudia; Richter, Bernhard; Baumann, Tobias; Schumacher, Martin; Echternach, Matthias

    2014-07-01

    In the evaluation of patients with local pathologic dilatation inside the upper airway a pressure-related testing seems important for understanding its pathophysiology and for developing a concept of intra-individually adjusted therapy. Commonly used diagnostic techniques like endoscopy or medical imaging including ultrasound, barium swallow or computer-assisted tomography (CT) have shown limitations either in evaluating a dynamic process or assessing the entirety of cervical structures. This article presents a case report of a professional trumpet player with bilateral pharyngoceles, introducing real-time and three-dimensional (3D) MRI as a helpful tool in the diagnosis of pressure dependent pathologies in the upper airway. With the use of MRI the complete sub- and supraglottic airway can be viewed simultaneously, avoiding the distortion which can occur with endoscopy. Thus, it was possible to evaluate the pharyngoceles pressure-related pathophysiology, from which a successful therapy could be conceived which included modifying the musician's blowing technique. PMID:24395345

  16. Laser based method for real-time three-dimensional monitoring of chest wall movement

    NASA Astrophysics Data System (ADS)

    Jezeršek, Matija; Povšič, Klemen; Topole, Eva; Fležar, Matjaž; Možina, Janez

    2010-05-01

    Novel method for monitoring the entire three-dimensional shape of the chest wall in real time is presented. The system is based on the multiple-line laser triangulation principle. The laser projector generates a light pattern of 33 equally inclined light planes directed toward the measured surface. The camera records the illuminated surface from a different viewpoint, and consequently, the light pattern is distorted by the shape of the surface. The acquired images are transferred in the personal computer, where contour detection, three-dimensional surface reconstruction, shape analysis, and displaying are performed in real time. Surface displacements are calculated by subtraction of the current measured surface from the reference one. Differences are displayed with color palette, where the blue represent the inward (negative) and the red represent the outward (positive) movement. The accuracy of the calibrated apparatus is +/-0.5 mm, which is calculated as a standard deviation between points of the measured and nominal reference surface. The measuring range is approximately 400×600×500 mm in width, height and depth. The intention of this study was to evaluate the system by means of its ability to distinguish between different breathing patterns and to verify the accuracy of measuring chest wall deformation volumes during breathing. The results demonstrate that the presented 3-d measuring system has a great potential as a diagnostic and training tool in case of monitoring the breathing pattern. We believe that exact graphical communication with the patient is much more simple and easy to understand than verbal and/or numerical.

  17. Acoustic Performance of a Real-Time Three-Dimensional Sound-Reproduction System

    NASA Technical Reports Server (NTRS)

    Faller, Kenneth J., II; Rizzi, Stephen A.; Aumann, Aric R.

    2013-01-01

    The Exterior Effects Room (EER) is a 39-seat auditorium at the NASA Langley Research Center and was built to support psychoacoustic studies of aircraft community noise. The EER has a real-time simulation environment which includes a three-dimensional sound-reproduction system. This system requires real-time application of equalization filters to compensate for spectral coloration of the sound reproduction due to installation and room effects. This paper describes the efforts taken to develop the equalization filters for use in the real-time sound-reproduction system and the subsequent analysis of the system s acoustic performance. The acoustic performance of the compensated and uncompensated sound-reproduction system is assessed for its crossover performance, its performance under stationary and dynamic conditions, the maximum spatialized sound pressure level it can produce from a single virtual source, and for the spatial uniformity of a generated sound field. Additionally, application examples are given to illustrate the compensated sound-reproduction system performance using recorded aircraft flyovers

  18. Analytical real-time measurement of a three-dimensional weld pool surface

    NASA Astrophysics Data System (ADS)

    Zhang, WeiJie; Wang, XueWu; Zhang, YuMing

    2013-11-01

    The ability to observe and measure weld pool surfaces in real-time is the core of the foundation for next generation intelligent welding that can partially imitate skilled welders who observe the weld pool to acquire information on the welding process. This study aims at the real-time measurement of the specular three-dimensional (3D) weld pool surface under a strong arc in gas tungsten arc welding (GTAW). An innovative vision system is utilized in this study to project a dot-matrix laser pattern on the specular weld pool surface. Its reflection from the surface is intercepted at a distance from the arc by a diffuse plane. The intercepted laser dots illuminate this plane producing an image showing the reflection pattern. The deformation of this reflection pattern from the projected pattern (e.g. the dot matrix) is used to derive the 3D shape of the reflection surface, i.e., the weld pool surface. Based on careful analysis, the underlying reconstruction problem is formulated mathematically. An analytic solution is proposed to solve this formulated problem resulting in the weld pool surface being reconstructed on average in 3.04 ms during welding experiments. A vision-based monitoring system is thus established to measure the weld pool surface in GTAW in real-time. In order to verify the effectiveness of the proposed reconstruction algorithm, first numerical simulation is conducted. The proposed algorithm is then tested on a spherical convex mirror with a priori knowledge of its geometry. The detailed analysis of the measurement error validates the accuracy of the proposed algorithm. Results from the real-time experiments verify the robustness of the proposed reconstruction algorithm.

  19. Three-dimensional localization of low activity gamma-ray sources in real-time scenarios

    NASA Astrophysics Data System (ADS)

    Sharma, Manish K.; Alajo, Ayodeji B.; Lee, Hyoung K.

    2016-03-01

    Radioactive source localization plays an important role in tracking radiation threats in homeland security tasks. Its real-time application requires computationally efficient and reasonably accurate algorithms even with limited data to support detection with minimum uncertainty. This paper describes a statistic-based grid-refinement method for backtracing the position of a gamma-ray source in a three-dimensional domain in real-time. The developed algorithm used measurements from various known detector positions to localize the source. This algorithm is based on an inverse-square relationship between source intensity at a detector and the distance from the source to the detector. The domain discretization was developed and implemented in MATLAB. The algorithm was tested and verified from simulation results of an ideal case of a point source in non-attenuating medium. Subsequently, an experimental validation of the algorithm was performed to determine the suitability of deploying this scheme in real-time scenarios. Using the measurements from five known detector positions and for a measurement time of 3 min, the source position was estimated with an accuracy of approximately 53 cm. The accuracy improved and stabilized to approximately 25 cm for higher measurement times. It was concluded that the error in source localization was primarily due to detection uncertainties. In verification and experimental validation of the algorithm, the distance between 137Cs source and any detector position was between 0.84 m and 1.77 m. The results were also compared with the least squares method. Since the discretization algorithm was validated with a weak source, it is expected that it can localize the source of higher activity in real-time. It is believed that for the same physical placement of source and detectors, a source of approximate activity 0.61-0.92 mCi can be localized in real-time with 1 s of measurement time and same accuracy. The accuracy and computational efficiency

  20. Real-time three-dimensional Fourier-domain optical coherence tomography video image guided microsurgeries

    PubMed Central

    Huang, Yong; Zhang, Kang; Ibrahim, Zuhaib; Cha, Jaepyeong; Lee, W. P. Andrew; Brandacher, Gerald; Gehlbach, Peter L.

    2012-01-01

    Abstract. The authors describe the development of an ultrafast three-dimensional (3D) optical coherence tomography (OCT) imaging system that provides real-time intraoperative video images of the surgical site to assist surgeons during microsurgical procedures. This system is based on a full-range complex conjugate free Fourier-domain OCT (FD-OCT). The system was built in a CPU-GPU heterogeneous computing architecture capable of video OCT image processing. The system displays at a maximum speed of 10  volume/s for an image volume size of 160×80×1024 (X×Y×Z) pixels. We have used this system to visualize and guide two prototypical microsurgical maneuvers: microvascular anastomosis of the rat femoral artery and ultramicrovascular isolation of the retinal arterioles of the bovine retina. Our preliminary experiments using 3D-OCT-guided microvascular anastomosis showed optimal visualization of the rat femoral artery (diameter<0.8  mm), instruments, and suture material. Real-time intraoperative guidance helped facilitate precise suture placement due to optimized views of the vessel wall during anastomosis. Using the bovine retina as a model system, we have performed “ultra microvascular” feasibility studies by guiding handheld surgical micro-instruments to isolate retinal arterioles (diameter∼0.1  mm). Isolation of the microvessels was confirmed by successfully passing a suture beneath the vessel in the 3D imaging environment. PMID:23224164

  1. Full high-definition real-time depth estimation for three-dimensional video system

    NASA Astrophysics Data System (ADS)

    Li, Hejian; An, Ping; Zhang, Zhaoyang

    2014-09-01

    Three-dimensional (3-D) video brings people strong visual perspective experience, but also introduces large data and complexity processing problems. The depth estimation algorithm is especially complex and it is an obstacle for real-time system implementation. Meanwhile, high-resolution depth maps are necessary to provide a good image quality on autostereoscopic displays which deliver stereo content without the need for 3-D glasses. This paper presents a hardware implementation of a full high-definition (HD) depth estimation system that is capable of processing full HD resolution images with a maximum processing speed of 125 fps and a disparity search range of 240 pixels. The proposed field-programmable gate array (FPGA)-based architecture implements a fusion strategy matching algorithm for efficiency design. The system performs with high efficiency and stability by using a full pipeline design, multiresolution processing, synchronizers which avoid clock domain crossing problems, efficient memory management, etc. The implementation can be included in the video systems for live 3-D television applications and can be used as an independent hardware module in low-power integrated applications.

  2. Toward real-time three-dimensional mapping of surficial aquifers using a hybrid modeling approach

    NASA Astrophysics Data System (ADS)

    Friedel, Michael J.; Esfahani, Akbar; Iwashita, Fabio

    2016-02-01

    A hybrid modeling approach is proposed for near real-time three-dimensional (3D) mapping of surficial aquifers. First, airborne frequency-domain electromagnetic (FDEM) measurements are numerically inverted to obtain subsurface resistivities. Second, a machine-learning (ML) algorithm is trained using the FDEM measurements and inverted resistivity profiles, and borehole geophysical and hydrogeologic data. Third, the trained ML algorithm is used together with independent FDEM measurements to map the spatial distribution of the aquifer system. Efficacy of the hybrid approach is demonstrated for mapping a heterogeneous surficial aquifer and confining unit in northwestern Nebraska, USA. For this case, independent performance testing reveals that aquifer mapping is unbiased with a strong correlation (0.94) among numerically inverted and ML-estimated binary (clay-silt or sand-gravel) layer resistivities (5-20 ohm-m or 21-5,000 ohm-m), and an intermediate correlation (0.74) for heterogeneous (clay, silt, sand, gravel) layer resistivities (5-5,000 ohm-m). Reduced correlation for the heterogeneous model is attributed to over-estimating the under-sampled high-resistivity gravels (about 0.5 % of the training data), and when removed the correlation increases (0.87). Independent analysis of the numerically inverted and ML-estimated resistivities finds that the hybrid procedure preserves both univariate and spatial statistics for each layer. Following training, the algorithms can map 3D surficial aquifers as fast as leveled FDEM measurements are presented to the ML network.

  3. Real-time monitoring of cisplatin cytotoxicity on three-dimensional spheroid tumor cells

    PubMed Central

    Baek, NamHuk; Seo, Ok Won; Lee, Jaehwa; Hulme, John; An, Seong Soo A

    2016-01-01

    Three-dimensional (3D) cell cultivation is a powerful technique for monitoring and understanding diverse cellular mechanisms in developmental cancer and neuronal biology, tissue engineering, and drug development. 3D systems could relate better to in vivo models than two-dimensional (2D) cultures. Several factors, such as cell type, survival rate, proliferation rate, and gene and protein expression patterns, determine whether a particular cell line can be adapted to a 3D system. The 3D system may overcome some of the limitations of 2D cultures in terms of cell–cell communication and cell networks, which are essential for understanding differentiation, structural organization, shape, and extended connections with other cells or organs. Here, the effect of the anticancer drug cisplatin, also known as cis-diamminedichloroplatinum (II) or CDDP, on adenosine triphosphate (ATP) generation was investigated using 3D spheroid-forming cells and real-time monitoring for 7 days. First, 12 cell lines were screened for their ability to form 3D spheroids: prostate (DU145), testis (F9), embryonic fibroblast (NIH-3T3), muscle (C2C12), embryonic kidney (293T), neuroblastoma (SH-SY5Y), adenocarcinomic alveolar basal epithelial cell (A549), cervical cancer (HeLa), HeLa contaminant (HEp2), pituitary epithelial-like cell (GH3), embryonic cell (PA317), and osteosarcoma (U-2OS) cells. Of these, eight cell lines were selected: NIH-3T3, C2C12, 293T, SH-SY5Y, A549, HeLa, PA317, and U-2OS; and five underwent real-time monitoring of CDDP cytotoxicity: HeLa, A549, 293T, SH-SY5Y, and U-2OS. ATP generation was blocked 1 day after addition of 50 μM CDDP, but cytotoxicity in HeLa, A549, SH-SY5Y, and U-2OS cells could be visualized only 4 days after treatment. In 293T cells, CDDP failed to kill entirely the culture and ATP generation was only partially blocked after 1 day. This suggests potential CDDP resistance of 293T cells or metabolic clearance of the drug. Real-time monitoring and ATP

  4. Real-time monitoring of cisplatin cytotoxicity on three-dimensional spheroid tumor cells.

    PubMed

    Baek, NamHuk; Seo, Ok Won; Lee, Jaehwa; Hulme, John; An, Seong Soo A

    2016-01-01

    Three-dimensional (3D) cell cultivation is a powerful technique for monitoring and understanding diverse cellular mechanisms in developmental cancer and neuronal biology, tissue engineering, and drug development. 3D systems could relate better to in vivo models than two-dimensional (2D) cultures. Several factors, such as cell type, survival rate, proliferation rate, and gene and protein expression patterns, determine whether a particular cell line can be adapted to a 3D system. The 3D system may overcome some of the limitations of 2D cultures in terms of cell-cell communication and cell networks, which are essential for understanding differentiation, structural organization, shape, and extended connections with other cells or organs. Here, the effect of the anticancer drug cisplatin, also known as cis-diamminedichloroplatinum (II) or CDDP, on adenosine triphosphate (ATP) generation was investigated using 3D spheroid-forming cells and real-time monitoring for 7 days. First, 12 cell lines were screened for their ability to form 3D spheroids: prostate (DU145), testis (F9), embryonic fibroblast (NIH-3T3), muscle (C2C12), embryonic kidney (293T), neuroblastoma (SH-SY5Y), adenocarcinomic alveolar basal epithelial cell (A549), cervical cancer (HeLa), HeLa contaminant (HEp2), pituitary epithelial-like cell (GH3), embryonic cell (PA317), and osteosarcoma (U-2OS) cells. Of these, eight cell lines were selected: NIH-3T3, C2C12, 293T, SH-SY5Y, A549, HeLa, PA317, and U-2OS; and five underwent real-time monitoring of CDDP cytotoxicity: HeLa, A549, 293T, SH-SY5Y, and U-2OS. ATP generation was blocked 1 day after addition of 50 μM CDDP, but cytotoxicity in HeLa, A549, SH-SY5Y, and U-2OS cells could be visualized only 4 days after treatment. In 293T cells, CDDP failed to kill entirely the culture and ATP generation was only partially blocked after 1 day. This suggests potential CDDP resistance of 293T cells or metabolic clearance of the drug. Real-time monitoring and ATP

  5. Three-dimensional liver motion tracking using real-time two-dimensional MRI

    SciTech Connect

    Brix, Lau; Ringgaard, Steffen; Sørensen, Thomas Sangild; Poulsen, Per Rugaard

    2014-04-15

    Purpose: Combined magnetic resonance imaging (MRI) systems and linear accelerators for radiotherapy (MR-Linacs) are currently under development. MRI is noninvasive and nonionizing and can produce images with high soft tissue contrast. However, new tracking methods are required to obtain fast real-time spatial target localization. This study develops and evaluates a method for tracking three-dimensional (3D) respiratory liver motion in two-dimensional (2D) real-time MRI image series with high temporal and spatial resolution. Methods: The proposed method for 3D tracking in 2D real-time MRI series has three steps: (1) Recording of a 3D MRI scan and selection of a blood vessel (or tumor) structure to be tracked in subsequent 2D MRI series. (2) Generation of a library of 2D image templates oriented parallel to the 2D MRI image series by reslicing and resampling the 3D MRI scan. (3) 3D tracking of the selected structure in each real-time 2D image by finding the template and template position that yield the highest normalized cross correlation coefficient with the image. Since the tracked structure has a known 3D position relative to each template, the selection and 2D localization of a specific template translates into quantification of both the through-plane and in-plane position of the structure. As a proof of principle, 3D tracking of liver blood vessel structures was performed in five healthy volunteers in two 5.4 Hz axial, sagittal, and coronal real-time 2D MRI series of 30 s duration. In each 2D MRI series, the 3D localization was carried out twice, using nonoverlapping template libraries, which resulted in a total of 12 estimated 3D trajectories per volunteer. Validation tests carried out to support the tracking algorithm included quantification of the breathing induced 3D liver motion and liver motion directionality for the volunteers, and comparison of 2D MRI estimated positions of a structure in a watermelon with the actual positions. Results: Axial, sagittal

  6. Nearly real-time visualization of arbitrary two-dimensional sections from three-dimensional acquisition.

    PubMed

    Capineri, L; Masotti, L; Rocchi, S; Andreuccetti, F; Cerofolini, M; Tondini, A

    1996-01-01

    This work presents a system for the reconstruction of cross-sections with arbitrary orientations derived from three-dimensional (3D) echographic scanners. The interest for this powerful diagnostic tool has prompted us to develop a low-cost processing board that inserts easily into a stand-alone echograph. The proposed system is able to reconstruct high-resolution cross-sections at one frame per second with a time lag of about 60 s due the 3D acquisition process. The board, based on three pipelined DSP devices, has been designed to process volumetric data collected with a commercial echograph by means a rotating probe synchronized with the ECG signal. The resolution of the reconstruction algorithm implemented on the processing unit has been evaluated both with synthetic 3D data and with experimental data from a phantom. PMID:8783464

  7. Real-Time Simulation of Three-Dimensional Shoulder Girdle and Arm Dynamics

    PubMed Central

    Chadwick, Edward K.; Blana, Dimitra; Kirsch, Robert F.; van den Bogert, Antonie J.

    2014-01-01

    Electrical stimulation is a promising technology for the restoration of arm function in paralysed individuals. Control of the paralysed arm under electrical stimulation, however, is a challenging problem that requires advanced controllers and command interfaces for the user. A real-time model describing the complex dynamics of the arm would allow user-in-the-loop type experiments where the command interface and controller could be assessed. Real-time models of the arm previously described have not included the ability to model the independently controlled scapula and clavicle, limiting their utility for clinical applications of this nature. The goal of this study therefore was to evaluate the performance and mechanical behaviour of a real-time, dynamic model of the arm and shoulder girdle. The model comprises seven segments linked by eleven degrees of freedom and actuated by 138 muscle elements. Polynomials were generated to describe the muscle lines of action to reduce computation time, and an implicit, first-order Rosenbrock formulation of the equations of motion was used to increase simulation step-size. The model simulated flexion of the arm faster than real time, simulation time being 92% of actual movement time on standard desktop hardware. Modelled maximum isometric torque values agreed well with values from the literature, showing that the model simulates the moment-generating behaviour of a real human arm. The speed of the model enables experiments where the user controls the virtual arm and receives visual feedback in real time. The ability to optimise potential solutions in simulation greatly reduces the burden on the user during development. PMID:24956613

  8. Real-time simulation of three-dimensional shoulder girdle and arm dynamics.

    PubMed

    Chadwick, Edward K; Blana, Dimitra; Kirsch, Robert F; van den Bogert, Antonie J

    2014-07-01

    Electrical stimulation is a promising technology for the restoration of arm function in paralyzed individuals. Control of the paralyzed arm under electrical stimulation, however, is a challenging problem that requires advanced controllers and command interfaces for the user. A real-time model describing the complex dynamics of the arm would allow user-in-the-loop type experiments where the command interface and controller could be assessed. Real-time models of the arm previously described have not included the ability to model the independently controlled scapula and clavicle, limiting their utility for clinical applications of this nature. The goal of this study therefore was to evaluate the performance and mechanical behavior of a real-time, dynamic model of the arm and shoulder girdle. The model comprises seven segments linked by eleven degrees of freedom and actuated by 138 muscle elements. Polynomials were generated to describe the muscle lines of action to reduce computation time, and an implicit, first-order Rosenbrock formulation of the equations of motion was used to increase simulation step-size. The model simulated flexion of the arm faster than real time, simulation time being 92% of actual movement time on standard desktop hardware. Modeled maximum isometric torque values agreed well with values from the literature, showing that the model simulates the moment-generating behavior of a real human arm. The speed of the model enables experiments where the user controls the virtual arm and receives visual feedback in real time. The ability to optimize potential solutions in simulation greatly reduces the burden on the user during development. PMID:24956613

  9. Gradient-index lens-array method based on real-time integral photography for three-dimensional images

    NASA Astrophysics Data System (ADS)

    Arai, Jun; Okano, Fumio; Hoshino, Haruo; Yuyama, Ichiro

    1998-04-01

    Because a three-dimensional (3-D) autostereoscopic image can be seen from a desired viewpoint without the aid of special viewing glasses, integral photography (IP) is an ideal way to create 3-D autostereoscopic images. We have already proposed a real-time IP method that offers 3-D autostereoscopic images of moving objects in real time by use of a microlens array and a high-definition television camera. But there are two problems yet to be resolved: One is pseudoscopic images that show a reversed depth representation. The other is interference between the element images that constitute a 3-D autostereoscopic image. We describe a new gradient-index lense-array method based on real-time IP to overcome these two problems. Experimental results indicating the advantages of this method are shown. These results suggest the possibility of using a gradient-index lens array for real-time IP.

  10. Real-time application of advanced three-dimensional graphic techniques for research aircraft simulation

    NASA Technical Reports Server (NTRS)

    Davis, Steven B.

    1990-01-01

    Visual aids are valuable assets to engineers for design, demonstration, and evaluation. Discussed here are a variety of advanced three-dimensional graphic techniques used to enhance the displays of test aircraft dynamics. The new software's capabilities are examined and possible future uses are considered.

  11. Towards a Three-Dimensional Near-Real Time Cloud Product for Aviation Safety and Weather Diagnoses

    NASA Technical Reports Server (NTRS)

    Minnis, Patrick; Nguyen, Louis; Palikonda, Rabindra; Spangeberg, Douglas; Nordeen, Michele L.; Yi, Yu-Hong; Ayers, J. Kirk

    2004-01-01

    Satellite data have long been used for determining the extent of cloud cover and for estimating the properties at the cloud tops. The derived properties can also be used to estimate aircraft icing potential to improve the safety of air traffic in the region. Currently, cloud properties and icing potential are derived in near-real time over the United States of America (USA) from the Geostationary Operational Environmental Satellite GOES) imagers at 75 W and 135 W. Traditionally, the results have been given in two dimensions because of the lack of knowledge about the vertical extent of clouds and the occurrence of overlapping clouds. Aircraft fly in a three-dimensional space and require vertical as well as horizontal information about clouds, their intensity, and their potential for icing. To improve the vertical component of the derived cloud and icing parameters, this paper explores various methods and datasets for filling in the three-dimensional space over the USA with cloud water.

  12. Multi-particle three-dimensional coordinate estimation in real-time optical manipulation

    NASA Astrophysics Data System (ADS)

    Dam, J. S.; Perch-Nielsen, I.; Palima, D.; Gluckstad, J.

    2009-11-01

    We have previously shown how stereoscopic images can be obtained in our three-dimensional optical micromanipulation system [J. S. Dam et al, Opt. Express 16, 7244 (2008)]. Here, we present an extension and application of this principle to automatically gather the three-dimensional coordinates for all trapped particles with high tracking range and high reliability without requiring user calibration. Through deconvolving of the red, green, and blue colour planes to correct for bleeding between colour planes, we show that we can extend the system to also utilize green illumination, in addition to the blue and red. Applying the green colour as on-axis illumination yields redundant information for enhanced error correction, which is used to verify the gathered data, resulting in reliable coordinates as well as producing visually attractive images.

  13. Determination of left ventricular volume, ejection fraction, and myocardial mass by real-time three-dimensional echocardiography

    NASA Technical Reports Server (NTRS)

    Qin, J. X.; Shiota, T.; Thomas, J. D.

    2000-01-01

    Reconstructed three-dimensional (3-D) echocardiography is an accurate and reproducible method of assessing left ventricular (LV) functions. However, it has limitations for clinical study due to the requirement of complex computer and echocardiographic analysis systems, electrocardiographic/respiratory gating, and prolonged imaging times. Real-time 3-D echocardiography has a major advantage of conveniently visualizing the entire cardiac anatomy in three dimensions and of potentially accurately quantifying LV volumes, ejection fractions, and myocardial mass in patients even in the presence of an LV aneurysm. Although the image quality of the current real-time 3-D echocardiographic methods is not optimal, its widespread clinical application is possible because of the convenient and fast image acquisition. We review real-time 3-D echocardiographic image acquisition and quantitative analysis for the evaluation of LV function and LV mass.

  14. Management of three-dimensional intrafraction motion through real-time DMLC tracking.

    PubMed

    Sawant, Amit; Venkat, Raghu; Srivastava, Vikram; Carlson, David; Povzner, Sergey; Cattell, Herb; Keall, Paul

    2008-05-01

    Tumor tracking using a dynamic multileaf collimator (DMLC) represents a promising approach for intrafraction motion management in thoracic and abdominal cancer radiotherapy. In this work, we develop, empirically demonstrate, and characterize a novel 3D tracking algorithm for real-time, conformal, intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT)-based radiation delivery to targets moving in three dimensions. The algorithm obtains real-time information of target location from an independent position monitoring system and dynamically calculates MLC leaf positions to account for changes in target position. Initial studies were performed to evaluate the geometric accuracy of DMLC tracking of 3D target motion. In addition, dosimetric studies were performed on a clinical linac to evaluate the impact of real-time DMLC tracking for conformal, step-and-shoot (S-IMRT), dynamic (D-IMRT), and VMAT deliveries to a moving target. The efficiency of conformal and IMRT delivery in the presence of tracking was determined. Results show that submillimeter geometric accuracy in all three dimensions is achievable with DMLC tracking. Significant dosimetric improvements were observed in the presence of tracking for conformal and IMRT deliveries to moving targets. A gamma index evaluation with a 3%-3 mm criterion showed that deliveries without DMLC tracking exhibit between 1.7 (S-IMRT) and 4.8 (D-IMRT) times more dose points that fail the evaluation compared to corresponding deliveries with tracking. The efficiency of IMRT delivery, as measured in the lab, was observed to be significantly lower in case of tracking target motion perpendicular to MLC leaf travel compared to motion parallel to leaf travel. Nevertheless, these early results indicate that accurate, real-time DMLC tracking of 3D tumor motion is feasible and can potentially result in significant geometric and dosimetric advantages leading to more effective management of intrafraction motion. PMID

  15. Real-time optical gating for three-dimensional beating heart imaging

    NASA Astrophysics Data System (ADS)

    Taylor, Jonathan M.; Saunter, Christopher D.; Love, Gordon D.; Girkin, John M.; Henderson, Deborah J.; Chaudhry, Bill

    2011-11-01

    We demonstrate real-time microscope image gating to an arbitrary position in the cycle of the beating heart of a zebrafish embryo. We show how this can be used for high-precision prospective gating of fluorescence image slices of the moving heart. We also present initial results demonstrating the application of this technique to 3-D structural imaging of the beating embryonic heart.

  16. Elasticity-based three dimensional ultrasound real-time volume rendering

    NASA Astrophysics Data System (ADS)

    Boctor, Emad M.; Matinfar, Mohammad; Ahmad, Omar; Rivaz, Hassan; Choti, Michael; Taylor, Russell H.

    2009-02-01

    Volumetric ultrasound imaging has not gained wide recognition, despite the availability of real-time 3D ultrasound scanners and the anticipated potential of 3D ultrasound imaging in diagnostic and interventional radiology. Their use, however, has been hindered by the lack of real-time visualization methods that are capable of producing high quality 3D rendering of the target/surface of interest. Volume rendering is a known visualization method, which can display clear surfaces out of the acquired volumetric data, and has an increasing number of applications utilizing CT and MRI data. The key element of any volume rendering pipeline is the ability to classify the target/surface of interest by setting an appropriate opacity function. Practical and successful real-time 3D ultrasound volume rendering can be achieved in Obstetrics and Angio applications where setting these opacity functions can be done rapidly, and reliably. Unfortunately, 3D ultrasound volume rendering of soft tissues is a challenging task due to the presence of significant amount of noise and speckle. Recently, several research groups have shown the feasibility of producing 3D elasticity volume from two consecutive 3D ultrasound scans. This report describes a novel volume rendering pipeline utilizing elasticity information. The basic idea is to compute B-mode voxel opacity from the rapidly calculated strain values, which can also be mixed with conventional gradient based opacity function. We have implemented the volume renderer using GPU unit, which gives an update rate of 40 volume/sec.

  17. Real-time optoacoustic monitoring and three-dimensional mapping of a human arm vasculature

    NASA Astrophysics Data System (ADS)

    Fronheiser, Matthew P.; Ermilov, Sergey A.; Brecht, Hans-Peter; Conjusteau, Andre; Su, Richard; Mehta, Ketan; Oraevsky, Alexander A.

    2010-03-01

    We present our findings from a real-time laser optoacoustic imaging system (LOIS). The system utilizes a Q-switched Nd:YAG laser; a standard 128-channel ultrasonic linear array probe; custom electronics and custom software to collect, process, and display optoacoustic (OA) images at 10 Hz. We propose that this system be used during preoperative mapping of forearm vessels for hemodialysis treatment. To demonstrate the real-time imaging capabilities of the system, we show OA images of forearm vessels in a volunteer and compare our results to ultrasound images of the same region. Our OA images show blood vessels in high contrast. Manipulations with the probe enable us to locate and track arteries and veins of a forearm in real time. We also demonstrate the ability to combine a series of OA image slices into a volume for spatial representation of the vascular network. Finally, we use frame-by-frame analysis of the recorded OA video to measure dynamic changes of the crossection of the ulnar artery.

  18. A real-time method for monitoring the three-dimensional extent of high power cw laser beams

    NASA Astrophysics Data System (ADS)

    Boyd, I. W.

    1983-06-01

    A simple and very accurate method is presented that allows not only one section of a cw laser beam to be studied in real-time but the full three-dimensional extent of its mode profile. The use of a ball-bearing to controllably defocus extremely high beam power densities in two planes is a novel approach which has been successfully used for beam measurements applied to laser-induced oxidation, and laser annealing of silicon. Although specifically applied to the infra-red regime, this technique may be extended to the study of visible radiation by using the appropriate detectors.

  19. Three Dimensional Motion Compensation for Real-Time MRI Guided Focused Ultrasound Treatment of Abdominal Organs

    NASA Astrophysics Data System (ADS)

    Ries, M.; De Senneville, B. D.; Roujol, S.; Hey, S.; Maclair, G.; Köhler, M. O.; Quesson, B.; Moonen, C. T. W.

    2010-03-01

    MR-guided high intensity focused ultrasound (HIFU) has evolved into a promising non-invasive technique for the ablation of pathological tissue in abdominal organs. However, since the high perfusion rates of these organs lead to effective cooling, sustained sonications of 30-90 s are required to achieve a sufficiently high temperature elevation to induce necrosis. This is complicated by the constant displacement of the target due to the respiratory cycle. This study proposes sub-second 3D HIFU-beam steering under MR-guidance for the near real-time compensation of respiratory motion as a possible solution. The target position is observed in 3D space by coupling rapid 2D MR-imaging with prospective slice tracking (PST) based on pencil-beam navigator echoes. Continuous real-time image processing provides temperature maps, thermal dose estimates and the target position at a frequency of 10 Hz and an update latency of less than 120 ms. The suggested method is evaluated with phantom experiments and its feasibility is verified in-vivo with an ablation experiment on a porcine kidney where it allows to achieve a thermal energy deposition which is comparable to static control experiments.

  20. GPU-assisted real-time three dimensional shape measurement by speckle-embedded fringe

    NASA Astrophysics Data System (ADS)

    Feng, Shijie; Chen, Qian; Zuo, Chao

    2015-07-01

    This paper presents a novel two-frame method of fringe projection for real-time, accurate and unambiguous threedimensional shape measurement. One of the used frames is a speckle pattern and the other one is a composite image which is fused by that speckle image and sinusoidal fringes. The sinusoidal component is used to retrieve the wrapped phase map. The frame of the speckle is employed to remove the phase ambiguity for the reconstruction of the absolute depth. Compared with traditional multi-frequency phase-shifting methods, the proposed scheme is of much lower sensitivity to movements as the result of the reduced number of used patterns. Moreover, its measuring precision is very close to that of the phase-shifting method, which indicates the method is of high accuracy. To process data in real time, a CUDA-enabled Graphics Processing Unit (GPU) is introduced to accelerate the computations of phase and depth. With our system, measurements can be performed at 21 frames per second with a resolution of 307K points per frame.

  1. Three-dimensional subband coding implemented in programmable real-time hardware

    NASA Astrophysics Data System (ADS)

    Glenn, William E.

    1995-02-01

    Pyramid codes such as 3-D subband coding, wavelet and fractile can be implemented with much simpler encoders and decoders than DCT-based compression systems. Since they do not use blocks, they do not suffer from blocking artifacts. They are particularly useful when the cost of the encoder is a concern, such as picture phone, teleconferencing, and camcorders. If used in production, post-production processing can be implemented without degradation. A programmable real-time encoder and decoder have been constructed for evaluating color 3-D subband coding algorithms. The results of tests with this hardware are presented for a wide range of compression ratios as well as the post-production processing of compressed video.

  2. Annular sizing using real-time three-dimensional intracardiac echocardiography-guided trans-catheter aortic valve replacement

    PubMed Central

    Rendon, Alejandro; Hamid, Tahir; Kanaganayagam, Gajen; Karunaratne, Devinda; Mahadevan, Vaikom S

    2016-01-01

    Objective Transcatheter aortic valve replacement (TAVR) has been established as an alternative therapy for patients with severe aortic stenosis who are unfit for the surgical aortic valve replacements. Pre and periprocedural imaging for the TAVR procedure is the key to procedural success. Currently transesophageal echocardiography (TOE), including real-time three-dimensional (RT-3D) imaging TOE, has been used for peri-interventional monitoring and guidance for TAVR. We describe our initial experience with real-time three-dimensional intracardiac echocardiography (RT-3DICE), imaging technology for the use in the TAVR procedure. Methods We used RT-3DICE using an ACUSON SC2000 2.0v (Siemens Medical Solution), and a 10F AcuNav V catheter (Siemens-Acuson, Inc, Mountain View, California, USA) in addition to preoperative multislice CT (MSCT) in total of five patients undergoing TAVR procedure. Results Aortic annulus and sinus of valsalva diameters were measured using RT-3DICE. Aortic valve measurements obtained using RT-3DICE are comparable to those obtained using MSCT with no significant difference in our patients. Conclusions This small study of five patients shows the safe use of RT-3DICE in TAVR Procedure and may help the procedures performed under local anaesthesia without the need for TOE. PMID:27158522

  3. Real-time telemedicine using shared three-dimensional workspaces over ATM

    NASA Astrophysics Data System (ADS)

    Cahoon, Peter; Forsey, David R.; Hutchison, Susan

    1999-03-01

    During the past five years a high speed ATM network has been developed at UBC that provides a campus testbed, a local testbed to the hospitals, and a National testbed between here and the BADLAB in Ottawa. This testbed has been developed to combine a commercial shared audio/video/whiteboard environment coupled with a shared interactive 3-dimensional solid model. This solid model ranges from a skull reconstructed from a CT scan with muscles and an overlying skin, to a model of the ventricle system of the human brain. Typical interactions among surgeon, radiologist and modeler consist of having image slices of the original scan shared by all and the ability to adjust the surface of the model to conform to each individuals perception of what the final object should look like. The purpose of this interaction can range from forensic reconstruction from partial remains to pre-maxillofacial surgery. A joint project with the forensic unit of the R.C.M.P. in Ottawa using the BADLAB is now in the stages of testing this methodology on a real case beginning with a CT scan of partial remains. A second study underway with the department of Maxiofacial reconstruction at Dalhousie University in Halifax Nova Scotia and concerns a subject who is about to undergo orthognathic surgery, in particular a mandibular advancement. This subject has been MRI scanned, a solid model constructed of the mandible and the virtual surgery constructed on the model. This model and the procedure have been discussed and modified by the modeler and the maxillofacial specialist using these shared workspaces. The procedure will be repeated after the actual surgery to verify the modeled procedure. The advantage of this technique is that none of the specialists need be in the same room, or city. Given the scarcity of time and specialists this methodology shows great promise. In November of this last year a shared live demonstration of this facial modeler was done between Vancouver and Dalhousie University in

  4. Fast interactive real-time volume rendering of real-time three-dimensional echocardiography: an implementation for low-end computers

    NASA Technical Reports Server (NTRS)

    Saracino, G.; Greenberg, N. L.; Shiota, T.; Corsi, C.; Lamberti, C.; Thomas, J. D.

    2002-01-01

    Real-time three-dimensional echocardiography (RT3DE) is an innovative cardiac imaging modality. However, partly due to lack of user-friendly software, RT3DE has not been widely accepted as a clinical tool. The object of this study was to develop and implement a fast and interactive volume renderer of RT3DE datasets designed for a clinical environment where speed and simplicity are not secondary to accuracy. Thirty-six patients (20 regurgitation, 8 normal, 8 cardiomyopathy) were imaged using RT3DE. Using our newly developed software, all 3D data sets were rendered in real-time throughout the cardiac cycle and assessment of cardiac function and pathology was performed for each case. The real-time interactive volume visualization system is user friendly and instantly provides consistent and reliable 3D images without expensive workstations or dedicated hardware. We believe that this novel tool can be used clinically for dynamic visualization of cardiac anatomy.

  5. Cohomology of real three-dimensional triquadrics

    NASA Astrophysics Data System (ADS)

    Krasnov, Vyacheslav A.

    2012-02-01

    We consider non-singular intersections of three real five-dimensional quadrics. They are referred to for brevity as real three-dimensional triquadrics. We calculate the dimensions of the cohomology spaces of triquadrics with coefficients in the field of two elements.

  6. Real-time displacement and strain mappings of lithium-ion batteries using three-dimensional digital image correlation

    NASA Astrophysics Data System (ADS)

    Leung, P. K.; Moreno, C.; Masters, I.; Hazra, S.; Conde, B.; Mohamed, M. R.; Dashwood, R. J.; Bhagat, R.

    2014-12-01

    This work presents the first application of three-dimensional digital image correlation for real-time displacement and strain analysis of a pouch type lithium-ion battery. During the electrochemical charge-discharge processes, displacements in the x-, y- and z-directions vary at different states-of-charge (SOCs) attributed to the expansion and the contraction of the interior structure. The z-displacement is observed to develop and concentrate at the vicinity of the openings of the jelly-roll structure. By resolving the displacement components, the progression and distribution of the surface strains, including principal and von-Mises strains, are computed in the charge-discharge processes. It is shown that the dominant strains are up to 0.12% in the rolling direction of the jelly-roll structure and distribute uniformly on the x-y plane over the surface.

  7. Two- and live/real time three-dimensional transthoracic echocardiographic assessment of infective endocarditis of a valved pulmonary conduit.

    PubMed

    Gulotta, John C; Gaba, Saurabh; Bulur, Serkan; Joson, Marisa; Sungur, Aylin; Nanda, Navin C

    2015-02-01

    We describe the use of a nonstandard left infraclavicular approach in making the diagnosis of an infected valved conduit with two-dimensional transthoracic echocardiography. The patient was an adult with tetralogy of Fallot and pulmonary atresia who had undergone multiple surgical repair procedures. The initial diagnosis of infective endocarditis was made by transesophageal echocardiography. Both techniques demonstrated a single, large vegetation in the conduit. Live/real time three-dimensional transthoracic echocardiography, on the other hand, provided further information by demonstrating several additional vegetations in the conduit and more comprehensively assessed their size by enabling measurement of their azimuthal dimensions and volumes. The patient was treated with antibiotics with complete resolution of the vegetations. PMID:25410293

  8. Graphics processing unit-assisted real-time three-dimensional measurement using speckle-embedded fringe.

    PubMed

    Feng, Shijie; Chen, Qian; Zuo, Chao

    2015-08-01

    This paper presents a novel two-frame fringe projection technique for real-time, accurate, and unambiguous three-dimensional (3D) measurement. One of the frames is a digital speckle pattern, and the other one is a composite image which is generated by fusing that speckle image with sinusoidal fringes. The contained sinusoidal component is used to obtain a wrapped phase map by Fourier transform profilometry, and the speckle image helps determine the fringe order for phase unwrapping. Compared with traditional methods, the proposed pattern scheme enables measurements of discontinuous surfaces with only two frames, greatly reducing the number of required patterns and thus reducing the sensitivity to movements. This merit makes the method very suitable for inspecting dynamic scenes. Moreover, it shows close performance in measurement accuracy compared with the phase-shifting method from our experiments. To process data in real time, a Compute Unified Device Architecture-enabled graphics processing unit is adopted to accelerate some time-consuming computations. With our system, measurements can be performed at 21 frames per second with a resolution of 307,000 points per frame. PMID:26368103

  9. Real-time three-dimensional optical coherence tomography image-guided core-needle biopsy system

    PubMed Central

    Kuo, Wei-Cheng; Kim, Jongsik; Shemonski, Nathan D.; Chaney, Eric J.; Spillman, Darold R.; Boppart, Stephen A.

    2012-01-01

    Advances in optical imaging modalities, such as optical coherence tomography (OCT), enable us to observe tissue microstructure at high resolution and in real time. Currently, core-needle biopsies are guided by external imaging modalities such as ultrasound imaging and x-ray computed tomography (CT) for breast and lung masses, respectively. These image-guided procedures are frequently limited by spatial resolution when using ultrasound imaging, or by temporal resolution (rapid real-time feedback capabilities) when using x-ray CT. One feasible approach is to perform OCT within small gauge needles to optically image tissue microstructure. However, to date, no system or core-needle device has been developed that incorporates both three-dimensional OCT imaging and tissue biopsy within the same needle for true OCT-guided core-needle biopsy. We have developed and demonstrate an integrated core-needle biopsy system that utilizes catheter-based 3-D OCT for real-time image-guidance for target tissue localization, imaging of tissue immediately prior to physical biopsy, and subsequent OCT imaging of the biopsied specimen for immediate assessment at the point-of-care. OCT images of biopsied ex vivo tumor specimens acquired during core-needle placement are correlated with corresponding histology, and computational visualization of arbitrary planes within the 3-D OCT volumes enables feedback on specimen tissue type and biopsy quality. These results demonstrate the potential for using real-time 3-D OCT for needle biopsy guidance by imaging within the needle and tissue during biopsy procedures. PMID:22741064

  10. Real-time volume rendering of four-dimensional images based on three-dimensional texture mapping.

    PubMed

    Hwang, J; Kim, J S; Kim, J S; Kim, I Y; Kim, S I

    2001-06-01

    A four-dimensional (4-D) image consists of three-dimensional (3-D) volume data that varies with time. It is used to express a deforming or moving object in virtual surgery or 4-D ultrasound. It is difficult to obtain 4-D images by conventional ray-casting or shear-warp factorization methods because of their time-consuming rendering process and the pre-processing stage necessary whenever the volume data are changed. Even when 3-D texture mapping is used, repeated volume loading is time-consuming in 4-D image rendering. In this study, we propose a method to reduce data loading time using coherence between currently loaded volume and previously loaded volume in order to achieve real-time rendering based on 3-D texture mapping. Volume data are divided into small bricks and each brick being loaded is tested for similarity to one that was already loaded in memory. If the brick passes the test, it is defined as 3-D texture by OpenGL functions. Later, the texture slices of the brick are mapped into polygons and blended by OpenGL blending functions. All bricks undergo this test. Using continuous deforming, 50 volumes are rendered in interactive time with SGI ONYX. Realtime volume rendering based on 3-D texture mapping is currently available for personal computers. PMID:11442097

  11. A Proposed Maneuver to Guide Transseptal Puncture Using Real-Time Three-Dimensional Transesophageal Echocardiography: Pilot Study

    PubMed Central

    Mahmoud, Hani M.; Al-Ghamdi, Mohammed A.; Ghabashi, Abdullah E.; Anwar, Ashraf M.

    2015-01-01

    Aim of Study. To assess the feasibility of a new proposed maneuver “RATLe-90” using real-time three-dimensional transesophageal echocardiography (RT-3DTEE) for anatomically oriented visualization of the interatrial septum (IAS) in guiding the transseptal puncture TSP. Methods. The study included 20 patients (mean age, 60.2 ± 6.7 years; 60% males) who underwent TSP for different indications. RT-3DTEE was used to guide TSP. The proposed maneuver RATLe-90 (Rotate-Anticlockwise-Tilt-Left-90) was applied in all cases to have the anatomically oriented en face view of the IAS from the right atrial (RA) aspect. Having this anatomically oriented view, we guided the TSP catheter towards the proper puncture site according to the planned procedure. Results. Using the RATLe-90 maneuver, the anatomically oriented en face view of the IAS from the RA was obtained in all patients. We were able to guide the puncture catheter to the proper puncture site on the IAS. The 3D images obtained were clearly understood by both echocardiographers and interventionists. The RATLe-90 maneuver acquisition time was 19.9 ± 1.6 seconds. The time-to-tent was 64.8 ± 16.3 seconds. Less TEE probe manipulations were needed while guiding the TSP. Conclusions. Application of RT3D-TEE during TSP using RATLe-90 maneuver is feasible with shorter fluoroscopy time and minimizing TEE probe manipulations. PMID:26106503

  12. Real-Time Three-Dimensional Cell Segmentation in Large-Scale Microscopy Data of Developing Embryos.

    PubMed

    Stegmaier, Johannes; Amat, Fernando; Lemon, William C; McDole, Katie; Wan, Yinan; Teodoro, George; Mikut, Ralf; Keller, Philipp J

    2016-01-25

    We present the Real-time Accurate Cell-shape Extractor (RACE), a high-throughput image analysis framework for automated three-dimensional cell segmentation in large-scale images. RACE is 55-330 times faster and 2-5 times more accurate than state-of-the-art methods. We demonstrate the generality of RACE by extracting cell-shape information from entire Drosophila, zebrafish, and mouse embryos imaged with confocal and light-sheet microscopes. Using RACE, we automatically reconstructed cellular-resolution tissue anisotropy maps across developing Drosophila embryos and quantified differences in cell-shape dynamics in wild-type and mutant embryos. We furthermore integrated RACE with our framework for automated cell lineaging and performed joint segmentation and cell tracking in entire Drosophila embryos. RACE processed these terabyte-sized datasets on a single computer within 1.4 days. RACE is easy to use, as it requires adjustment of only three parameters, takes full advantage of state-of-the-art multi-core processors and graphics cards, and is available as open-source software for Windows, Linux, and Mac OS. PMID:26812020

  13. Microvascular anastomosis guidance and evaluation using real-time three-dimensional Fourier-domain Doppler optical coherence tomography

    PubMed Central

    Ibrahim, Zuhaib; Tong, Dedi; Zhu, Shan; Mao, Qi; Pang, John; Andrew Lee, Wei Ping; Brandacher, Gerald; Kang, Jin U.

    2013-01-01

    Abstract. Vascular and microvascular anastomoses are critical components of reconstructive microsurgery, vascular surgery, and transplant surgery. Intraoperative surgical guidance using a surgical imaging modality that provides an in-depth view and three-dimensional (3-D) imaging can potentially improve outcome following both conventional and innovative anastomosis techniques. Objective postoperative imaging of the anastomosed vessel can potentially improve the salvage rate when combined with other clinical assessment tools, such as capillary refill, temperature, blanching, and skin turgor. Compared to other contemporary postoperative monitoring modalities—computed tomography angiograms, magnetic resonance (MR) angiograms, and ultrasound Doppler—optical coherence tomography (OCT) is a noninvasive high-resolution (micron-level), high-speed, 3-D imaging modality that has been adopted widely in biomedical and clinical applications. For the first time, to the best of our knowledge, the feasibility of real-time 3-D phase-resolved Doppler OCT (PRDOCT) as an assisted intra- and postoperative imaging modality for microvascular anastomosis of rodent femoral vessels is demonstrated, which will provide new insights and a potential breakthrough to microvascular and supermicrovascular surgery. PMID:23856833

  14. Second-generation real-time three-dimensional echocardiography. Finally on its way into clinical cardiology?

    PubMed

    von Bardeleben, R S; Kühl, H P; Mohr-Kahaly, S; Franke, A

    2004-01-01

    Three-dimensional (3D) echocardiographic imaging has been introduced as a tool to improve the assessment of both morphologic and functional parameters of the cardiovascular system. In the past, data acquisition was limited due to time-consuming sequential acquisition of multiple triggered 2D image planes from 10-60 heart cycles using transesophageal rotational, transthoracic rotational or transthoracic freehand approaches. Recent improvements in the size of matrix array probes and in computing power of modern ultrasound equipment have significantly increased both spatial and temporal resolution of "second-generation" real-time 3D scanners. Although the superiority of 3D echocardiography in the determination of ventricular volume, ventricular mass or valvular orifice area had already been demonstrated in the late 1990s, widespread use in clinical cardiology was limited on account of difficulties in acquisition and post-processing. Clinical use of modern 3D echocardiography is boosted by the marked reduction in acquisition time and the unique possibility of on-line rendering on the ultrasound system. The ability to visualize a virtual 3D surface in real time-although limited to a sector size of about 30 degrees-offers new insights into cardiac pathomorpholgy even in patients with arrhythmias and may in realtime 3D-contrast flow analysis. Analysis of wide-angle 3D datasets (90 by 90 degree pyramidal shape) is possible by combining the 3D information of several [4-7] consecutive heart cycles. 3D datasets including the complete left ventricle provide comprehensive information on ventricular and mitral valve morphology and function. Qualitative and quantitative analyses of regional wall motion at rest and during stress become possible. Combination with 3D color Doppler data allows additional assessment of valvular function as well as determination of flow in the left ventricular outflow tract and across septal defects. The integration and future quantification of these

  15. The advantages of live/real time three-dimensional transesophageal echocardiography during assessments of pulmonary stenosis.

    PubMed

    Kemaloğlu Öz, Tuğba; Özpamuk Karadeniz, Fatma; Akyüz, Şükrü; Ünal Dayı, Şennur; Esen Zencirci, Aycan; Atasoy, Işıl; Ösken, Altuğ; Eren, Mehmet

    2016-04-01

    This report sought to compare live/real-time three-dimensional transesophageal echocardiography (3D-TEE) with two-dimensional transesophageal echocardiography (2D-TEE) and to determine whether there are advantages to using 3D-TEE on patients with pulmonary stenosis (PS). Sixteen consecutive adult patients (50 % male and 50 % female; mean age 33 ± 13.4 years) with PS and indications of TEE were prospectively enrolled in this study. Following this, initial 2D-TEE and 3D-TEE examinations were performed, and 3D-TEE images were analyzed using an off-line Q-lab software system. Finally, the 2D-TEE and 3D-TEE findings were compared. In the present study, 3D-TEE allowed us to obtain the en face views of pulmonary valves (PVs) in all but one patient. While this patient was without a PV due to a previous tetralogy of Fallot operation, we could detect the type of PV in the other 15 (93.7 %) patients by using 3D-TEE. Due to poor image quality, the most stenotic area was not measurable in only one (6.2 %) of the patients. In eight (50 %) of the patients, severity and localization of stenosis were more precisely determined with 3DTEE than with 2D-TEE. The PVs' maximal annulus dimensions were found to be significantly larger when they were measured using 3D modalities. This study provides evidence of the incremental value of using 3D-TEE rather than 2D-TEE during assessments of PS, specifically in cases where special conditions (pregnancy, pulmonary regurgitation, and concomitant atrial septal defects) cause recordings of the transvalvular peak gradient to be inaccurate. Therefore, 3D-TEE should be used as a complementary imaging tool to 2D-TEE during routine echocardiographic examinations. PMID:26613764

  16. Incremental value of live/real time three-dimensional over two-dimensional transesophageal echocardiography in the evaluation of right coronary artery fistula.

    PubMed

    Mishra, Jaymala; Puri, Hari Prakash; Hsiung, Ming C; Misra, Stuti; Khairnar, Prakash; Laxmi Gollamudi, Bhargavi; Patel, Adilahmed; Nanda, Navin C; Yin, Wei-Hsian; Wei, Jeng; Tsai, Shen-Kou; Sudhakar, Selvin

    2011-08-01

    We report an adult with a right coronary artery to right atrial fistula in whom live/real time three-dimensional transesophageal echocardiography with its ability to trace the entire course and obtain en face views of the fistula connections, was able to provide significant incremental information over two-dimensional transesophageal echocardiography. PMID:21752093

  17. Incremental value of live/real time three-dimensional transesophageal echocardiography over the two-dimensional technique in the assessment of sinus of valsalva aneurysm rupture.

    PubMed

    Raslan, Saleem; Nanda, Navin C; Lloyd, Lancelot; Khairnar, Prakash; Reilly, Stephanie D; Holman, William L

    2011-09-01

    We present an adult patient with rupture of the right sinus of Valsalva aneurysm in whom the two-dimensional transesophageal echocardiogram failed to show the rupture. On the other hand, live/real time three-dimensional transesophageal echocardiography clearly delineated the site of rupture into the pericardium and mediastinum. PMID:21827544

  18. Early change in left atrial function in patients treated with anthracyclines assessed by real-time three-dimensional echocardiography

    PubMed Central

    Shi, Jing; Guo, Ye; Cheng, Leilei; Song, Feiyan; Shu, Xianhong

    2016-01-01

    Real-time three-dimensional echocardiography(RT-3DE) has allowed a better assessment of LA volumes and function. We sought to assess the early change in left atrial size and function in patients treated with anthracyclines using RT-3DE. 61 patients aged 44.9 ± 11.9 years with large B-cell non-Hodgkin lymphoma treated with doxorubicin were studied. Blood collection and echocardiography were performed at baseline and 1 day after completion of the chemotherapy. Global longitudinal strain (GLS), maximum, minimum and pre-atrial contraction LA volumes were measured and reservoir, conduit and booster pump function were assessed. Despite normal LVEF, passive emptying percent of total emptying (0.51 ± 0.14 vs. 0.40 ± 0.12, P < 0.001) and passive emptying index (0.29 ± 0.10 vs. 0.23 ± 0.06, P < 0.001) were remarkably reduced compared to baseline values, while active emptying percent of total emptying (0.49 ± 0.14 vs. 0.60 ± 0.12, P < 0.001) and active emptying index (0.41 ± 0.16 vs. 0.47 ± 0.16, P = 0.048) were increased. GLS (−21.64 ± 2.83 vs. −17.30 ± 2.50) was markedly reduced, cTnT levels was elevated from 0.005 ± 0.004 to 0.020 ± 0.026 ng/mL at the completion of chemotherapy (P all  < 0.001). Early LA functional change occur after doxorubicin exposure in patients with preserved LVEF, which could be detected by RT-3DE. PMID:27149058

  19. A study of the application of singular perturbation theory. [development of a real time algorithm for optimal three dimensional aircraft maneuvers

    NASA Technical Reports Server (NTRS)

    Mehra, R. K.; Washburn, R. B.; Sajan, S.; Carroll, J. V.

    1979-01-01

    A hierarchical real time algorithm for optimal three dimensional control of aircraft is described. Systematic methods are developed for real time computation of nonlinear feedback controls by means of singular perturbation theory. The results are applied to a six state, three control variable, point mass model of an F-4 aircraft. Nonlinear feedback laws are presented for computing the optimal control of throttle, bank angle, and angle of attack. Real Time capability is assessed on a TI 9900 microcomputer. The breakdown of the singular perturbation approximation near the terminal point is examined Continuation methods are examined to obtain exact optimal trajectories starting from the singular perturbation solutions.

  20. Real-time in situ three-dimensional integral videography and surgical navigation using augmented reality: a pilot study

    PubMed Central

    Suenaga, Hideyuki; Hoang Tran, Huy; Liao, Hongen; Masamune, Ken; Dohi, Takeyoshi; Hoshi, Kazuto; Mori, Yoshiyuki; Takato, Tsuyoshi

    2013-01-01

    To evaluate the feasibility and accuracy of a three-dimensional augmented reality system incorporating integral videography for imaging oral and maxillofacial regions, based on preoperative computed tomography data. Three-dimensional surface models of the jawbones, based on the computed tomography data, were used to create the integral videography images of a subject's maxillofacial area. The three-dimensional augmented reality system (integral videography display, computed tomography, a position tracker and a computer) was used to generate a three-dimensional overlay that was projected on the surgical site via a half-silvered mirror. Thereafter, a feasibility study was performed on a volunteer. The accuracy of this system was verified on a solid model while simulating bone resection. Positional registration was attained by identifying and tracking the patient/surgical instrument's position. Thus, integral videography images of jawbones, teeth and the surgical tool were superimposed in the correct position. Stereoscopic images viewed from various angles were accurately displayed. Change in the viewing angle did not negatively affect the surgeon's ability to simultaneously observe the three-dimensional images and the patient, without special glasses. The difference in three-dimensional position of each measuring point on the solid model and augmented reality navigation was almost negligible (<1 mm); this indicates that the system was highly accurate. This augmented reality system was highly accurate and effective for surgical navigation and for overlaying a three-dimensional computed tomography image on a patient's surgical area, enabling the surgeon to understand the positional relationship between the preoperative image and the actual surgical site, with the naked eye. PMID:23703710

  1. Initial clinical experience of real-time three-dimensional echocardiography in patients with ischemic and idiopathic dilated cardiomyopathy

    NASA Technical Reports Server (NTRS)

    Shiota, T.; McCarthy, P. M.; White, R. D.; Qin, J. X.; Greenberg, N. L.; Flamm, S. D.; Wong, J.; Thomas, J. D.

    1999-01-01

    The geometry of the left ventricle in patients with cardiomyopathy is often sub-optimal for 2-dimensional ultrasound when assessing left ventricular (LV) function and localized abnormalities such as a ventricular aneurysm. The aim of this study was to report the initial experience of real-time 3-D echocardiography for evaluating patients with cardiomyopathy. A total of 34 patients were evaluated with the real-time 3D method in the operating room (n = 15) and in the echocardiographic laboratory (n = 19). Thirteen of 28 patients with cardiomyopathy and 6 other subjects with normal LV function were evaluated by both real-time 3-D echocardiography and magnetic resonance imaging (MRI) for obtaining LV volumes and ejection fractions for comparison. There were close relations and agreements for LV volumes (r = 0.98, p <0.0001, mean difference = -15 +/- 81 ml) and ejection fractions (r = 0.97, p <0.0001, mean difference = 0.001 +/- 0.04) between the real-time 3D method and MRI when 3 cardiomyopathy cases with marked LV dilatation (LV end-diastolic volume >450 ml by MRI) were excluded. In these 3 patients, 3D echocardiography significantly underestimated the LV volumes due to difficulties with imaging the entire LV in a 60 degrees x 60 degrees pyramidal volume. The new real-time 3D echocardiography is feasible in patients with cardiomyopathy and may provide a faster and lower cost alternative to MRI for evaluating cardiac function in patients.

  2. Real-time three-dimensional imaging sonar for in-situ tracking of zooplankton in the ocean

    NASA Astrophysics Data System (ADS)

    Reuss, Edward L.; Jaffe, Jules S.

    1992-11-01

    Marine zooplankton form a significant part of the marine ecosystem since they are relatively low on the food chain and they exist in vast quantities. However, little is known of their behavior, how they feed, how they interact or their swimming patterns. To explore some of these issues a three-dimensional imaging sonar was developed to track the movements of these zooplankton in their native environment. The tracking problem requires a high frequency sonar with a fast frame update rate and reasonably high resolutions in three dimensions. It also requires a small array to minimize the proximity effects of the transducer package on the zooplankton behavior, to allow mounting of the transducer array on small remotely operated submersible vehicles and to reduce the cost of the sonar. This led to an array architecture which resolves the target volume of interest into a three-dimensional array of volumetric units that are digitized and stored in computer memory. This digitized array of numbers is then processed by the computer and the results displayed using a three-dimensional graphics imaging package to present a 3-D image depicting the back scatter strength of the target volume along with the location of any objects within that volume.

  3. Real-time single-shot three-dimensional and contrast-enhanced optical coherence imaging using phase coherent photorefractive quantum wells

    NASA Astrophysics Data System (ADS)

    Kabir, A.; Dongol, A.; Wang, X.; Wagner, H. P.

    2010-12-01

    We demonstrate two real-time optical coherence imaging acquisition modes using all-optical phase coherent photorefractive ZnSe quantum wells as dynamic holographic films. These films use the coherence of excitons for time-gating which provides depth information of an object according to the brightness profile of its holographic image. This quality allows depth-resolved imaging of moving particles with a resolution of a few micrometers in a single-shot three-dimensional mode. In a complementary contrast-enhanced mode moving particles are imaged by the local enhancement of a static reference hologram, enabling optical coherence imaging at a large depth-of-field.

  4. Real time three-dimensional space video rate sensors for millimeter waves imaging based very inexpensive plasma LED lamps

    NASA Astrophysics Data System (ADS)

    Levanon, Assaf; Yitzhaky, Yitzhak; Kopeika, Natan S.; Rozban, Daniel; Abramovich, Amir

    2014-10-01

    In recent years, much effort has been invested to develop inexpensive but sensitive Millimeter Wave (MMW) detectors that can be used in focal plane arrays (FPAs), in order to implement real time MMW imaging. Real time MMW imaging systems are required for many varied applications in many fields as homeland security, medicine, communications, military products and space technology. It is mainly because this radiation has high penetration and good navigability through dust storm, fog, heavy rain, dielectric materials, biological tissue, and diverse materials. Moreover, the atmospheric attenuation in this range of the spectrum is relatively low and the scattering is also low compared to NIR and VIS. The lack of inexpensive room temperature imaging systems makes it difficult to provide a suitable MMW system for many of the above applications. In last few years we advanced in research and development of sensors using very inexpensive (30-50 cents) Glow Discharge Detector (GDD) plasma indicator lamps as MMW detectors. This paper presents three kinds of GDD sensor based lamp Focal Plane Arrays (FPA). Those three kinds of cameras are different in the number of detectors, scanning operation, and detection method. The 1st and 2nd generations are 8 × 8 pixel array and an 18 × 2 mono-rail scanner array respectively, both of them for direct detection and limited to fixed imaging. The last designed sensor is a multiplexing frame rate of 16x16 GDD FPA. It permits real time video rate imaging of 30 frames/ sec and comprehensive 3D MMW imaging. The principle of detection in this sensor is a frequency modulated continuous wave (FMCW) system while each of the 16 GDD pixel lines is sampled simultaneously. Direct detection is also possible and can be done with a friendly user interface. This FPA sensor is built over 256 commercial GDD lamps with 3 mm diameter International Light, Inc., Peabody, MA model 527 Ne indicator lamps as pixel detectors. All three sensors are fully supported

  5. Successful intraoperative identification of an anomalous origin of the left coronary artery from the pulmonary artery using real time three-dimensional transesophageal echocardiography.

    PubMed

    Jin, Yao Dong; Hsiung, Ming C; Tsai, Shen Kou; Chang, Chung-Yi; Wei, Jeng; Ou, Ching-huei; Chang, Yi Cheng; Lee, Kuo Chen; Sue, Sung-How

    2011-08-01

    Anomalous origin of the left coronary artery (LCA) from the pulmonary artery (ALCAPA) is a rare congenital defect that presents only infrequently in adults. An adult diagnosed with ALCAPA, heart failure, and mitral regurgitation underwent surgical ligation of the anomalous origin of the LCA from the pulmonary artery (PA) and coronary artery bypass grafting (CABG). The anomalous origin in the PA and proximal segment of the left anterior descending artery (LAD) was successfully delineated via real time, three-dimensional transesophageal echocardiography during surgery. This modality allows for fast assessment and novel views of complex cardiac abnormalities and can aid in perioperative monitoring.  PMID:21564280

  6. Real time three-dimensional transesophageal echocardiography guided coronary sinus cannulation during CARILLON mitral annuloplasty device therapy for a patient with chronic severe mitral regurgitation.

    PubMed

    Mahmoud, Hani M; Al-Ghamdi, Mohammed A; Ghabashi, Abdullah E

    2015-01-01

    The coronary sinus (CS) has become a clinically important structure especially through its role in providing access for different cardiac procedures such as arrhythmia ablation, biventricular pacing and recently, percutaneous valvular interventions. Fluoroscopy with or without two-dimensional transesophageal echocardiography is the widely used method for guidance. A 78-year-old female patient undergoing percutaneous CARILLON mitral annuloplasty device therapy for chronic severe symptomatic mitral regurgitation. After insertion of the CS catheter through the right internal jugular vein, multiple trials for CS cannulation guided by fluoroscopy and two-dimensional transesophageal echocardiography were unsuccessful. So, real time three-dimensional zoom mode was used. Then, the volume was rotated to have the anatomically oriented enface view of the interatrial septum from the right atrial perspective. The CS ostium was identified adjacent to the eustachian valve. Then the catheter was reintroduced through the superior vena cava into the right atrium then easily navigated to cannulate the CS ostium. The position was confirmed by the fluoroscopically known course of the CS plus the pattern of the invasive pressure wave form. CS cannulation is not always feasible using fluoroscopy and/or two-dimensional Echocardiography guidance. Real time three-dimensional transesophageal echocardiography can be used to guide CS cannulation as it provides an anatomically oriented and informative enface view of the CS ostium. It can help reducing fluoroscopic radiation time. PMID:25231878

  7. Three-dimensional reach trajectories as a probe of real-time decision-making between multiple competing targets

    PubMed Central

    Gallivan, Jason P.; Chapman, Craig S.

    2014-01-01

    Though several features of cognitive processing can be inferred from the discrete measurement [e.g., reaction time (RT), accuracy, etc.] of participants' conscious reports (e.g., verbal or key-press responses), it is becoming increasingly clear that a much richer understanding of these features can be captured from continuous measures of rapid, largely non-conscious behaviors like hand or eye movements. Here, using new experimental data, we describe in detail both the approach and analyses implemented in some of our previous studies that have used rapid reaching movements under cases of target uncertainty in order to probe the features, constraints and dynamics of stimulus-related processing in the brain. This work, as well as that of others, shows that when individuals are simultaneously presented with multiple potential targets—only one of which will be cued after reach onset—they produce initial reach trajectories that are spatially biased in accordance with the probabilistic distribution of targets. Such “spatial averaging” effects are consistent with observations from neurophysiological studies showing that neuronal populations in sensorimotor brain structures represent multiple target choices in parallel and they compete for selection. These effects also confirm and help extend computational models aimed at understanding the underlying mechanisms that support action-target selection. We suggest that the use of this simple, yet powerful behavioral paradigm for providing a “real-time” visualization of ongoing cognitive processes occurring at the neural level offers great promise for studying processes related to a wide range of psychological phenomena, such as decision-making and the representation of objects. PMID:25100941

  8. Real-time three-dimensional echocardiographic study of left ventricular function after infarct exclusion surgery for ischemic cardiomyopathy

    NASA Technical Reports Server (NTRS)

    Qin, J. X.; Shiota, T.; McCarthy, P. M.; Firstenberg, M. S.; Greenberg, N. L.; Tsujino, H.; Bauer, F.; Travaglini, A.; Hoercher, K. J.; Buda, T.; Smedira, N. G.; Thomas, J. D.

    2000-01-01

    BACKGROUND: Infarct exclusion (IE) surgery, a technique of left ventricular (LV) reconstruction for dyskinetic or akinetic LV segments in patients with ischemic cardiomyopathy, requires accurate volume quantification to determine the impact of surgery due to complicated geometric changes. METHODS AND RESULTS: Thirty patients who underwent IE (mean age 61+/-8 years, 73% men) had epicardial real-time 3-dimensional echocardiographic (RT3DE) studies performed before and after IE. RT3DE follow-up was performed transthoracically 42+/-67 days after surgery in 22 patients. Repeated measures ANOVA was used to compare the values before and after IE surgery and at follow-up. Significant decreases in LV end-diastolic (EDVI) and end-systolic (ESVI) volume indices were apparent immediately after IE and in follow-up (EDVI 99+/-40, 67+/-26, and 71+/-31 mL/m(2), respectively; ESVI 72+/-37, 40+/-21, and 42+/-22 mL/m(2), respectively; P:<0.05). LV ejection fraction increased significantly and remained higher (0.29+/-0.11, 0.43+/-0.13, and 0.42+/-0.09, respectively, P:<0.05). Forward stroke volume in 16 patients with preoperative mitral regurgitation significantly improved after IE and in follow-up (22+/-12, 53+/-24, and 58+/-21 mL, respectively, P:<0.005). New York Heart Association functional class at an average 285+/-144 days of clinical follow-up significantly improved from 3.0+/-0.8 to 1.8+/-0.8 (P:<0.0001). Smaller end-diastolic and end-systolic volumes measured with RT3DE immediately after IE were closely related to improvement in New York Heart Association functional class at clinical follow-up (Spearman's rho=0.58 and 0.60, respectively). CONCLUSIONS: RT3DE can be used to quantitatively assess changes in LV volume and function after complicated LV reconstruction. Decreased LV volume and increased ejection fraction imply a reduction in LV wall stress after IE surgery and are predictive of symptomatic improvement.

  9. New digital measurement methods for left ventricular volume using real-time three-dimensional echocardiography: comparison with electromagnetic flow method and magnetic resonance imaging

    NASA Technical Reports Server (NTRS)

    Qin, J. J.; Jones, M.; Shiota, T.; Greenberg, N. L.; Firstenberg, M. S.; Tsujino, H.; Zetts, A. D.; Sun, J. P.; Cardon, L. A.; Odabashian, J. A.; Flamm, S. D.; White, R. D.; Panza, J. A.; Thomas, J. D.

    2000-01-01

    AIM: The aim of this study was to investigate the feasibility and accuracy of using symmetrically rotated apical long axis planes for the determination of left ventricular (LV) volumes with real-time three-dimensional echocardiography (3DE). METHODS AND RESULTS: Real-time 3DE was performed in six sheep during 24 haemodynamic conditions with electromagnetic flow measurements (EM), and in 29 patients with magnetic resonance imaging measurements (MRI). LV volumes were calculated by Simpson's rule with five 3DE methods (i.e. apical biplane, four-plane, six-plane, nine-plane (in which the angle between each long axis plane was 90 degrees, 45 degrees, 30 degrees or 20 degrees, respectively) and standard short axis views (SAX)). Real-time 3DE correlated well with EM for LV stroke volumes in animals (r=0.68-0.95) and with MRI for absolute volumes in patients (r-values=0.93-0.98). However, agreement between MRI and apical nine-plane, six-plane, and SAX methods in patients was better than those with apical four-plane and bi-plane methods (mean difference = -15, -18, -13, vs. -31 and -48 ml for end-diastolic volume, respectively, P<0.05). CONCLUSION: Apically rotated measurement methods of real-time 3DE correlated well with reference standards for calculating LV volumes. Balancing accuracy and required time for these LV volume measurements, the apical six-plane method is recommended for clinical use.

  10. Pixel multiplexing technique for real-time three-dimensional-imaging laser detection and ranging system using four linear-mode avalanche photodiodes.

    PubMed

    Xu, Fan; Wang, Yuanqing; Li, Fenfang

    2016-03-01

    The avalanche-photodiode-array (APD-array) laser detection and ranging (LADAR) system has been continually developed owing to its superiority of nonscanning, large field of view, high sensitivity, and high precision. However, how to achieve higher-efficient detection and better integration of the LADAR system for real-time three-dimensional (3D) imaging continues to be a problem. In this study, a novel LADAR system using four linear mode APDs (LmAPDs) is developed for high-efficient detection by adopting a modulation and multiplexing technique. Furthermore, an automatic control system for the array LADAR system is proposed and designed by applying the virtual instrumentation technique. The control system aims to achieve four functions: synchronization of laser emission and rotating platform, multi-channel synchronous data acquisition, real-time Ethernet upper monitoring, and real-time signal processing and 3D visualization. The structure and principle of the complete system are described in the paper. The experimental results demonstrate that the LADAR system is capable of achieving real-time 3D imaging on an omnidirectional rotating platform under the control of the virtual instrumentation system. The automatic imaging LADAR system utilized only 4 LmAPDs to achieve 256-pixel-per-frame detection with by employing 64-bit demodulator. Moreover, the lateral resolution is ∼15 cm and range accuracy is ∼4 cm root-mean-square error at a distance of ∼40 m. PMID:27036763

  11. Pixel multiplexing technique for real-time three-dimensional-imaging laser detection and ranging system using four linear-mode avalanche photodiodes

    NASA Astrophysics Data System (ADS)

    Xu, Fan; Wang, Yuanqing; Li, Fenfang

    2016-03-01

    The avalanche-photodiode-array (APD-array) laser detection and ranging (LADAR) system has been continually developed owing to its superiority of nonscanning, large field of view, high sensitivity, and high precision. However, how to achieve higher-efficient detection and better integration of the LADAR system for real-time three-dimensional (3D) imaging continues to be a problem. In this study, a novel LADAR system using four linear mode APDs (LmAPDs) is developed for high-efficient detection by adopting a modulation and multiplexing technique. Furthermore, an automatic control system for the array LADAR system is proposed and designed by applying the virtual instrumentation technique. The control system aims to achieve four functions: synchronization of laser emission and rotating platform, multi-channel synchronous data acquisition, real-time Ethernet upper monitoring, and real-time signal processing and 3D visualization. The structure and principle of the complete system are described in the paper. The experimental results demonstrate that the LADAR system is capable of achieving real-time 3D imaging on an omnidirectional rotating platform under the control of the virtual instrumentation system. The automatic imaging LADAR system utilized only 4 LmAPDs to achieve 256-pixel-per-frame detection with by employing 64-bit demodulator. Moreover, the lateral resolution is ˜15 cm and range accuracy is ˜4 cm root-mean-square error at a distance of ˜40 m.

  12. Real three-dimensional objects: effects on mental rotation.

    PubMed

    Felix, Michael C; Parker, Joshua D; Lee, Charles; Gabriel, Kara I

    2011-08-01

    The current experiment investigated real three-dimensional (3D) objects with regard to performance on a mental rotation task and whether the appearance of sex differences may be mediated by experiences with spatially related activities. 40 men and 40 women were presented with alternating timed trials consisting of real-3D objects or two-dimensional illustrations of 3D objects. Sex differences in spatially related activities did not significantly influence the finding that men outperformed women on mental rotation of either stimulus type. However, on measures related to spatial activities, self-reported proficiency using maps correlated positively with performance only on trials with illustrations whereas self-reported proficiency using GPS correlated negatively with performance regardless of stimulus dimensionality. Findings may be interpreted as suggesting that rotating real-3D objects utilizes distinct but overlapping spatial skills compared to rotating two-dimensional representations of 3D objects, and real-3D objects can enhance mental rotation performance. PMID:21987908

  13. Impact of left ventricular outflow tract area on systolic outflow velocity in hypertrophic cardiomyopathy: a real-time three-dimensional echocardiographic study

    NASA Technical Reports Server (NTRS)

    Qin, Jian Xin; Shiota, Takahiro; Lever, Harry M.; Rubin, David N.; Bauer, Fabrice; Kim, Yong Jin; Sitges, Marta; Greenberg, Neil L.; Drinko, Jeanne K.; Martin, Maureen; Agler, Deborah A.; Thomas, James D.

    2002-01-01

    OBJECTIVES: The aim of this study was to use real-time three-dimensional echocardiography (3DE) to investigate the quantitative relation between minimal left ventricular (LV) outflow tract area (A(LVOT)) and maximal LV outflow tract (LVOT) velocity in patients with hypertrophic obstructive cardiomyopathy (HCM). BACKGROUND: In patients with HCM, LVOT velocity should change inversely with minimal A(LVOT) unless LVOT obstruction reduces the pumping capacity of the ventricle. METHODS: A total of 25 patients with HCM with systolic anterior motion (SAM) of the mitral valve leaflets underwent real-time 3DE. The smallest A(LVOT) during systole was measured using anatomically oriented two-dimensional "C-planes" within the pyramidal 3DE volume. Maximal velocity across LVOT was evaluated by two-dimensional Doppler echocardiography (2DE). For comparison with 3DE A(LVOT), the SAM-septal distance was determined by 2DE. RESULTS: Real-time 3DE provided unique information about the dynamic SAM-septal relation during systole, with A(LVOT) ranging from 0.6 to 5.2 cm(2) (mean: 2.2 +/- 1.4 cm(2)). Maximal velocity (v) correlated inversely with A(LVOT) (v = 496 A(LVOT)(-0.80), r = -0.95, p < 0.001), but the exponent (-0.80) was significantly different from -1.0 (95% confidence interval: -0.67 to -0.92), indicating a significant impact of small A(LVOT) on the peak LVOT flow rate. By comparison, the best correlation between velocity and 2DE SAM-septal distance was significantly (p < 0.01) poorer at -0.83, indicating the superiority of 3DE for assessing A(LVOT). CONCLUSIONS: Three-dimensional echocardiography-measured A(LVOT) provides an assessment of HCM geometry that is superior to 2DE methods. These data indicate that the peak LVOT flow rate appears to be significantly decreased by reduced A(LVOT). Real-time 3DE is a potentially valuable clinical tool for assessing patients with HCM.

  14. Real-time three-dimensional color Doppler echocardiography for characterizing the spatial velocity distribution and quantifying the peak flow rate in the left ventricular outflow tract

    NASA Technical Reports Server (NTRS)

    Tsujino, H.; Jones, M.; Shiota, T.; Qin, J. X.; Greenberg, N. L.; Cardon, L. A.; Morehead, A. J.; Zetts, A. D.; Travaglini, A.; Bauer, F.; Panza, J. A.; Thomas, J. D.

    2001-01-01

    Quantification of flow with pulsed-wave Doppler assumes a "flat" velocity profile in the left ventricular outflow tract (LVOT), which observation refutes. Recent development of real-time, three-dimensional (3-D) color Doppler allows one to obtain an entire cross-sectional velocity distribution of the LVOT, which is not possible using conventional 2-D echo. In an animal experiment, the cross-sectional color Doppler images of the LVOT at peak systole were derived and digitally transferred to a computer to visualize and quantify spatial velocity distributions and peak flow rates. Markedly skewed profiles, with higher velocities toward the septum, were consistently observed. Reference peak flow rates by electromagnetic flow meter correlated well with 3-D peak flow rates (r = 0.94), but with an anticipated underestimation. Real-time 3-D color Doppler echocardiography was capable of determining cross-sectional velocity distributions and peak flow rates, demonstrating the utility of this new method for better understanding and quantifying blood flow phenomena.

  15. Object tracking mask-based NLUT on GPUs for real-time generation of holographic videos of three-dimensional scenes.

    PubMed

    Kwon, M-W; Kim, S-C; Yoon, S-E; Ho, Y-S; Kim, E-S

    2015-02-01

    A new object tracking mask-based novel-look-up-table (OTM-NLUT) method is proposed and implemented on graphics-processing-units (GPUs) for real-time generation of holographic videos of three-dimensional (3-D) scenes. Since the proposed method is designed to be matched with software and memory structures of the GPU, the number of compute-unified-device-architecture (CUDA) kernel function calls and the computer-generated hologram (CGH) buffer size of the proposed method have been significantly reduced. It therefore results in a great increase of the computational speed of the proposed method and enables real-time generation of CGH patterns of 3-D scenes. Experimental results show that the proposed method can generate 31.1 frames of Fresnel CGH patterns with 1,920 × 1,080 pixels per second, on average, for three test 3-D video scenarios with 12,666 object points on three GPU boards of NVIDIA GTX TITAN, and confirm the feasibility of the proposed method in the practical application of electro-holographic 3-D displays. PMID:25836082

  16. Nanoelectronic three-dimensional (3D) nanotip sensing array for real-time, sensitive, label-free sequence specific detection of nucleic acids.

    PubMed

    Esfandyarpour, Rahim; Yang, Lu; Koochak, Zahra; Harris, James S; Davis, Ronald W

    2016-02-01

    The improvements in our ability to sequence and genotype DNA have opened up numerous avenues in the understanding of human biology and medicine with various applications, especially in medical diagnostics. But the realization of a label free, real time, high-throughput and low cost biosensing platforms to detect molecular interactions with a high level of sensitivity has been yet stunted due to two factors: one, slow binding kinetics caused by the lack of probe molecules on the sensors and two, limited mass transport due to the planar structure (two-dimensional) of the current biosensors. Here we present a novel three-dimensional (3D), highly sensitive, real-time, inexpensive and label-free nanotip array as a rapid and direct platform to sequence-specific DNA screening. Our nanotip sensors are designed to have a nano sized thin film as their sensing area (~ 20 nm), sandwiched between two sensing electrodes. The tip is then conjugated to a DNA oligonucleotide complementary to the sequence of interest, which is electrochemically detected in real-time via impedance changes upon the formation of a double-stranded helix at the sensor interface. This 3D configuration is specifically designed to improve the biomolecular hit rate and the detection speed. We demonstrate that our nanotip array effectively detects oligonucleotides in a sequence-specific and highly sensitive manner, yielding concentration-dependent impedance change measurements with a target concentration as low as 10 pM and discrimination against even a single mismatch. Notably, our nanotip sensors achieve this accurate, sensitive detection without relying on signal indicators or enhancing molecules like fluorophores. It can also easily be scaled for highly multiplxed detection with up to 5000 sensors/square centimeter, and integrated into microfluidic devices. The versatile, rapid, and sensitive performance of the nanotip array makes it an excellent candidate for point-of-care diagnostics, and high

  17. Nanoelectronic three-dimensional (3D) nanotip sensing array for real-time, sensitive, label-free sequence specific detection of nucleic acids

    PubMed Central

    Yang, Lu; koochak, Zahra; Harris, James S.; Davis, Ronald W.

    2016-01-01

    The improvements in our ability to sequence and genotype DNA have opened up numerous avenues in the understanding of human biology and medicine with various applications, especially in medical diagnostics. But the realization of a label free, real time, high-throughput and low cost biosensing platforms to detect molecular interactions with a high level of sensitivity has been yet stunted due to two factors: one, slow binding kinetics caused by the lack of probe molecules on the sensors and two, limited mass transport due to the planar structure (two-dimensional) of the current biosensors. Here we present a novel three-dimensional (3D), highly sensitive, real-time, inexpensive and label-free nanotip array as a rapid and direct platform to sequence-specific DNA screening. Our nanotip sensors are designed to have a nano sized thin film as their sensing area (~ 20 nm), sandwiched between two sensing electrodes. The tip is then conjugated to a DNA oligonucleotide complementary to the sequence of interest, which is electrochemically detected in real-time via impedance changes upon the formation of a double-stranded helix at the sensor interface. This 3D configuration is specifically designed to improve the biomolecular hit rate and the detection speed. We demonstrate that our nanotip array effectively detects oligonucleotides in a sequence-specific and highly sensitive manner, yielding concentration-dependent impedance change measurements with a target concentration as low as 10 pM and discrimination against even a single mismatch. Notably, our nanotip sensors achieve this accurate, sensitive detection without relying on signal indicators or enhancing molecules like fluorophores. It can also easily be scaled for highly multiplxed detection with up to 5000 sensors/square centimeter, and integrated into microfluidic devices. The versatile, rapid, and sensitive performance of the nanotip array makes it an excellent candidate for point-of-care diagnostics, and high

  18. Three-dimensional particle tracking method using FPGA-based real-time image processing and four-view image splitter

    NASA Astrophysics Data System (ADS)

    Kreizer, Mark; Liberzon, Alex

    2011-03-01

    We present a cost-effective solution of the three-dimensional particle tracking velocimetry (3D-PTV) system based on the real-time image processing method (Kreizer et al. Exp Fluids 48:105-110, 2010) and a four-view image splitter. The image processing algorithm, based on the intensity threshold and intensity gradients estimated using the fixed-size Sobel kernel, is implemented on the field-programmable gate array integrated into the camera electronics. It enables extracting positions of tracked objects, such as tracers or large particles, in real time. The second major component of this system is a four-view split-screen device that provides four views of the observation volume from different angles. An open-source ray-tracing software package allows for a customized optical setup for the given experimental settings of working distances and camera parameters. The specific design enables tracking in larger observation volumes when compared to the designs published up to date. The present cost-effective solution is complemented with open-source particle tracking software that receives raw data acquired by the real-time image processing system and returns trajectories of the identified particles. The combination of these components simplifies the 3D-PTV technique by reducing the size and increasing recording speed and storage capabilities. The system is capable to track a multitude of particles at high speed and stream the data over the computer network. The system can provide a solution for the remotely controlled tracking experiments, such as in microgravity, underwater or in applications with harsh experimental conditions.

  19. Objective evaluation of changes in left ventricular and atrial volumes during parabolic flight using real-time three-dimensional echocardiography.

    PubMed

    Caiani, E G; Sugeng, L; Weinert, L; Capderou, A; Lang, R M; Vaïda, P

    2006-08-01

    We tested the feasibility of real-time three-dimensional (3D) echocardiographic (RT3DE) imaging to measure left heart volumes at different gravity during parabolic flight and studied the effects of lower body negative pressure (LBNP) as a countermeasure. Weightlessness-related changes in cardiac function have been previously studied during spaceflights using both 2D and 3D echocardiography. Several technical factors, such as inability to provide real-time analysis and the need for laborious endocardial definition, have limited its usefulness. RT3DE imaging overcomes these limitations by acquiring real-time pyramidal data sets encompassing the entire ventricle. RT3DE data sets were obtained (Philips 7500, X3) during breath hold in 16 unmedicated normal subjects in upright standing position at different gravity phases during parabolic flight (normogravity, 1 Gz; hypergravity, 1.8 Gz; microgravity, 0 Gz), with LBNP applied (-50 mmHg) at 0 Gz in selected parabolas. RT3DE imaging during parabolic flight was feasible in 14 of 16 subjects. Data were analyzed (Tomtec) to quantify left ventricular (LV) and atrial (LA) volumes at end diastole and end systole, which significantly decreased at 1.8 Gz and increased at 0 Gz. While ejection fraction did not change with gravity, stroke volume was reduced by 16% at 1.8 Gz and increased by 20% at 0 Gz, but it was not significantly different from 1 Gz values with LBNP. RT3DE during parabolic flight is feasible and provides the basis for accurate quantification of LV and LA volume changes with gravity. As LBNP counteracted the increase of LV and LA volumes caused by changes in venous return, it may be effectively used for preventing cardiac dilatation during 0 Gz. PMID:16601310

  20. Bootstrapping Critical Ising Model on Three Dimensional Real Projective Space.

    PubMed

    Nakayama, Yu

    2016-04-01

    Given conformal data on a flat Euclidean space, we use crosscap conformal bootstrap equations to numerically solve the Lee-Yang model as well as the critical Ising model on a three dimensional real projective space. We check the rapid convergence of our bootstrap program in two dimensions from the exact solutions available. Based on the comparison, we estimate that our systematic error on the numerically solved one-point functions of the critical Ising model on a three dimensional real projective space is less than 1%. Our method opens up a novel way to solve conformal field theories on nontrivial geometries. PMID:27104697

  1. Bootstrapping Critical Ising Model on Three Dimensional Real Projective Space

    NASA Astrophysics Data System (ADS)

    Nakayama, Yu

    2016-04-01

    Given conformal data on a flat Euclidean space, we use crosscap conformal bootstrap equations to numerically solve the Lee-Yang model as well as the critical Ising model on a three dimensional real projective space. We check the rapid convergence of our bootstrap program in two dimensions from the exact solutions available. Based on the comparison, we estimate that our systematic error on the numerically solved one-point functions of the critical Ising model on a three dimensional real projective space is less than 1%. Our method opens up a novel way to solve conformal field theories on nontrivial geometries.

  2. High precision in Raman frequency achieved using real-time calibration with a neon emission line: application to three-dimensional stress mapping observations.

    PubMed

    Odake, Shoko; Fukura, Satoshi; Kagi, Hiroyuki

    2008-10-01

    A three-dimensional (3D) Raman mapping system with a real-time calibration function was developed for detecting stress distributions in solid materials from subtle frequency shifts in Raman spectra. An atomic emission line of neon at 918.3 cm(-1) when excited at 514.5 nm was used as a wavenumber standard. An emission spectrum of neon and a Raman spectrum from a sample were introduced into a single polychromator using a bifurcated optical fiber. These two spectra were recorded simultaneously on a charge-coupled device (CCD) detector using double-track mode. Energy deviation induced by the fluctuation of laboratory temperature, etc., was removed effectively using the neon emission line. High stability during long measurements was achieved. By applying curve fitting, positions of the Raman line were determined with precision of about 0.05 cm(-1). The present system was applied to measurements of residual pressure around mineral inclusions in a natural diamond: 3D stress mapping was achieved. PMID:18926016

  3. Two-dimensional tissue tracking: a novel echocardiographic technique to measure left atrial volume: comparison with biplane area length method and real time three-dimensional echocardiography.

    PubMed

    Li, Shi-Yan; Zhang, Li; Zhao, Bo-Wen; Yu, Chan; Xu, Li-Long; Li, Peng; Xu, Ke; Pan, Mei; Wang, Bei

    2014-07-01

    Enlargement of the left atrium is an independent predictor of adverse cardiovascular outcomes, and an accurate, convenient imaging modality is necessary for clinical practice. The objectives of this study were to evaluate the feasibility of a novel imaging technique, two-dimensional tissue tracking (2DTT), for assessment of left atrial (LA) volume and function and to compare its correlation and agreement with biplane area length (AL) method and real time three-dimensional echocardiography (RT3DE). A total of 105 patients prospectively underwent 2DTT, AL and RT3DE. The LA volume index (LAVI) and emptying fraction were measured. In addition, intra- and inter-observer agreement were calculated by using the intraclass correlation coefficient. There were no significant differences in LAVI and emptying fraction measured by 2DTT in comparison with those made by AL or RT3DE, furthermore Bland-Altman analysis showed that 2DTT had significantly better agreement for LAVI and emptying fraction with AL and RT3DE. 2DTT also exhibited smaller intra- and inter-observer variability as compared with AL or RT3DE. Furthermore, the time to measure LA volume and acquire time-volume curve was significantly less by 2DTT than that by RT3DE (U = 49.00, P < 0.001). These observations suggest that the 2DTT could provide valuable information which is consistent with the standard AL and RT3DE measurements for LAVI and function with potentially lower intra- and inter-observer variability. PMID:24460543

  4. Application of Real-Time Three-Dimensional Echocardiography to Evaluate the Pre- and Postoperative Right Ventricular Systolic Function of Patients with Tetralogy of Fallot

    PubMed Central

    Cui, Cunying; Liu, Lin; Fan, Taibing; Peng, Bangtian; Cheng, Zhaoyun; Ge, Zhenwei; Li, Yanan; Liu, Yuanyuan; Zhang, Yanwei; Ai, Feng; Zhang, Lianzhong

    2015-01-01

    Tetralogy of Fallot (ToF) can be challenging for clinicians to both diagnose and treat, given the multiple heart defects that are by definition associated with the illness. This study investigates the value of real-time three- dimensional echocardiography (RT-3DE) in evaluating the pre-and postoperative right ventricular systolic function of patients with tetralogy of Fallot. A total of 41 ToF patients were divided into two groups: the child group (CG) and the adult group (AG) according to age. The right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV), and the right ventricular ejection fraction (RVEF) of ToF patients were measured before surgery, 7 days, and 3 months after the surgery. The correlation between the preoperative Nakata index and RVEF was then analyzed. Compared with the RVEDV and RVESV prior to surgery, those of the postoperative 7-day and 3-month were not statistically significant (p > 0.05). However, RVEF decreased, and the difference was statistically significant (p < 0.05). The differences in RVEDV, RVESV, and RVEF between postoperative 3-month and 7-day were not significant (p > 0.05). Compared with the pre-and postoperative RVEDV and RVESV of CG, those of AG increased. However, RVEF decreased, and the differences were statistically significant (p < 0.05). Our study indicated that the correlation between preoperative Nakata index and RVEF was good. Ultimately, we did confirm that RT-3DE can quantitatively evaluate the right ventricular volume and systolic function of ToF patients, thereby providing clinical significance in determining postoperative efficacy and prognosis evaluation. PMID:27122891

  5. Validation of real-time three-dimensional echocardiography for quantifying left ventricular volumes in the presence of a left ventricular aneurysm: in vitro and in vivo studies

    NASA Technical Reports Server (NTRS)

    Qin, J. X.; Jones, M.; Shiota, T.; Greenberg, N. L.; Tsujino, H.; Firstenberg, M. S.; Gupta, P. C.; Zetts, A. D.; Xu, Y.; Ping Sun, J.; Cardon, L. A.; Odabashian, J. A.; Flamm, S. D.; White, R. D.; Panza, J. A.; Thomas, J. D.

    2000-01-01

    OBJECTIVES: To validate the accuracy of real-time three-dimensional echocardiography (RT3DE) for quantifying aneurysmal left ventricular (LV) volumes. BACKGROUND: Conventional two-dimensional echocardiography (2DE) has limitations when applied for quantification of LV volumes in patients with LV aneurysms. METHODS: Seven aneurysmal balloons, 15 sheep (5 with chronic LV aneurysms and 10 without LV aneurysms) during 60 different hemodynamic conditions and 29 patients (13 with chronic LV aneurysms and 16 with normal LV) underwent RT3DE and 2DE. Electromagnetic flow meters and magnetic resonance imaging (MRI) served as reference standards in the animals and in the patients, respectively. Rotated apical six-plane method with multiplanar Simpson's rule and apical biplane Simpson's rule were used to determine LV volumes by RT3DE and 2DE, respectively. RESULTS: Both RT3DE and 2DE correlated well with actual volumes for aneurysmal balloons. However, a significantly smaller mean difference (MD) was found between RT3DE and actual volumes (-7 ml for RT3DE vs. 22 ml for 2DE, p = 0.0002). Excellent correlation and agreement between RT3DE and electromagnetic flow meters for LV stroke volumes for animals with aneurysms were observed, while 2DE showed lesser correlation and agreement (r = 0.97, MD = -1.0 ml vs. r = 0.76, MD = 4.4 ml). In patients with LV aneurysms, better correlation and agreement between RT3DE and MRI for LV volumes were obtained (r = 0.99, MD = -28 ml) than between 2DE and MRI (r = 0.91, MD = -49 ml). CONCLUSIONS: For geometrically asymmetric LVs associated with ventricular aneurysms, RT3DE can accurately quantify LV volumes.

  6. Viscous real gas flowfields about three dimensional configurations

    NASA Technical Reports Server (NTRS)

    Balakrishnan, A.; Davy, W. C.

    1983-01-01

    Laminar, real gas hypersonic flowfields over a three dimensional configuration are computed using an unsteady, factored implicit scheme. Local chemical and thermodynamic properties are evaluated by an equilibrium composition method. Transport properties are obtained from individual species properties and application of a mixture rule. Numerical solutions are presented for an ideal gas and equilibrium air for free-stream Mach numbers of 13 and 15 and at various angles of attack. The effect of real gas is to decrease the shock-layer thickness resulting from decreased shock-layer temperatures and corresponding increased density. The combined effects of viscosity and real gas are to increase the subsonic layer near the wall.

  7. Real gas flow fields about three dimensional configurations

    NASA Technical Reports Server (NTRS)

    Balakrishnan, A.; Lombard, C. K.; Davy, W. C.

    1983-01-01

    Real gas, inviscid supersonic flow fields over a three-dimensional configuration are determined using a factored implicit algorithm. Air in chemical equilibrium is considered and its local thermodynamic properties are computed by an equilibrium composition method. Numerical solutions are presented for both real and ideal gases at three different Mach numbers and at two different altitudes. Selected results are illustrated by contour plots and are also tabulated for future reference. Results obtained compare well with existing tabulated numerical solutions and hence validate the solution technique.

  8. Real-time three-dimensional color doppler evaluation of the flow convergence zone for quantification of mitral regurgitation: Validation experimental animal study and initial clinical experience

    NASA Technical Reports Server (NTRS)

    Sitges, Marta; Jones, Michael; Shiota, Takahiro; Qin, Jian Xin; Tsujino, Hiroyuki; Bauer, Fabrice; Kim, Yong Jin; Agler, Deborah A.; Cardon, Lisa A.; Zetts, Arthur D.; Panza, Julio A.; Thomas, James D.

    2003-01-01

    BACKGROUND: Pitfalls of the flow convergence (FC) method, including 2-dimensional imaging of the 3-dimensional (3D) geometry of the FC surface, can lead to erroneous quantification of mitral regurgitation (MR). This limitation may be mitigated by the use of real-time 3D color Doppler echocardiography (CE). Our objective was to validate a real-time 3D navigation method for MR quantification. METHODS: In 12 sheep with surgically induced chronic MR, 37 different hemodynamic conditions were studied with real-time 3DCE. Using real-time 3D navigation, the radius of the largest hemispherical FC zone was located and measured. MR volume was quantified according to the FC method after observing the shape of FC in 3D space. Aortic and mitral electromagnetic flow probes and meters were balanced against each other to determine reference MR volume. As an initial clinical application study, 22 patients with chronic MR were also studied with this real-time 3DCE-FC method. Left ventricular (LV) outflow tract automated cardiac flow measurement (Toshiba Corp, Tokyo, Japan) and real-time 3D LV stroke volume were used to quantify the reference MR volume (MR volume = 3DLV stroke volume - automated cardiac flow measurement). RESULTS: In the sheep model, a good correlation and agreement was seen between MR volume by real-time 3DCE and electromagnetic (y = 0.77x + 1.48, r = 0.87, P <.001, delta = -0.91 +/- 2.65 mL). In patients, real-time 3DCE-derived MR volume also showed a good correlation and agreement with the reference method (y = 0.89x - 0.38, r = 0.93, P <.001, delta = -4.8 +/- 7.6 mL). CONCLUSIONS: real-time 3DCE can capture the entire FC image, permitting geometrical recognition of the FC zone geometry and reliable MR quantification.

  9. Three dimensional time reversal optical tomography

    NASA Astrophysics Data System (ADS)

    Wu, Binlin; Cai, W.; Alrubaiee, M.; Xu, M.; Gayen, S. K.

    2011-03-01

    Time reversal optical tomography (TROT) approach is used to detect and locate absorptive targets embedded in a highly scattering turbid medium to assess its potential in breast cancer detection. TROT experimental arrangement uses multi-source probing and multi-detector signal acquisition and Multiple-Signal-Classification (MUSIC) algorithm for target location retrieval. Light transport from multiple sources through the intervening medium with embedded targets to the detectors is represented by a response matrix constructed using experimental data. A TR matrix is formed by multiplying the response matrix by its transpose. The eigenvectors with leading non-zero eigenvalues of the TR matrix correspond to embedded objects. The approach was used to: (a) obtain the location and spatial resolution of an absorptive target as a function of its axial position between the source and detector planes; and (b) study variation in spatial resolution of two targets at the same axial position but different lateral positions. The target(s) were glass sphere(s) of diameter ~9 mm filled with ink (absorber) embedded in a 60 mm-thick slab of Intralipid-20% suspension in water with an absorption coefficient μa ~ 0.003 mm-1 and a transport mean free path lt ~ 1 mm at 790 nm, which emulate the average values of those parameters for human breast tissue. The spatial resolution and accuracy of target location depended on axial position, and target contrast relative to the background. Both the targets could be resolved and located even when they were only 4-mm apart. The TROT approach is fast, accurate, and has the potential to be useful in breast cancer detection and localization.

  10. Time of Closest Approach in Three-Dimensional Airspace

    NASA Technical Reports Server (NTRS)

    Munoz, Cesar A.; Narkawicz, Anthony J.

    2010-01-01

    In air traffic management, the aircraft separation requirement is defined by a minimum horizontal distance and a minimum vertical distance that the aircraft have to maintain. Since this requirement defines a cylinder around each aircraft rather than a sphere, the three-dimensional Euclidean distance does not provide an appropriate basis for the definition of time of closest approach. For instance, conflicting aircraft are not necessarily in loss of separation at the time of closest three-dimensional Euclidean distance. This paper proposes a definition of time of closest approach that characterizes conflicts in a three-dimensional airspace. The proposed time is defined as the time that minimizes a distance metric called cylindrical norm. An algorithm that computes the time of closest approach between two aircraft is provided and the formal verification of its main properties is reported.

  11. Real-time bronchoscope three-dimensional motion estimation using multiple sensor-driven alignment of CT images and electromagnetic measurements.

    PubMed

    Luo, Xiongbiao; Mori, Kensaku

    2014-09-01

    Bronchoscope three-dimensional motion estimation plays a key role in developing bronchoscopic navigation systems. Currently external tracking devices, particularly electromagnetic trackers with electromagnetic sensors, are increasingly introduced to navigate surgical tools in pre-clinical images. An unavoidable problem, which is to align the electromagnetic tracker to pre-clinical images, must be solved before navigation. This paper proposes a multiple sensor-driven registration method to establish this alignment without using any anatomical fiducials. Although current fiducially free registration methods work well, they limit to the initialization of optimization and manipulating the bronchoscope along the bronchial centerlines, which could be failed easily during clinical interventions. To address these limitations, we utilize measurements of multiple electromagnetic sensors to calculate bronchoscope geometric center positions that are usually closer to the bronchial centerlines than the sensor itself measured positions. We validated our method on a bronchial phantom. The experimental results demonstrate that our idea of using multiple sensors to determine bronchoscope geometric center positions for fiducial-free registration was very effective. Compared to currently available methods in bronchoscope three-dimensional motion estimation, our method reduced fiducial alignment error from at least 6.79 to 4.68-5.26 mm and significantly improved motion estimation or tracking accuracy from at least 5.42 to 3.78-4.53 mm. PMID:25002104

  12. Importance of mitral valve repair associated with left ventricular reconstruction for patients with ischemic cardiomyopathy: a real-time three-dimensional echocardiographic study

    NASA Technical Reports Server (NTRS)

    Qin, Jian Xin; Shiota, Takahiro; McCarthy, Patrick M.; Asher, Craig R.; Hail, Melanie; Agler, Deborah A.; Popovic, Zoran B.; Greenberg, Neil L.; Smedira, Nicholas G.; Starling, Randall C.; Young, James B.; Thomas, James D.

    2003-01-01

    BACKGROUND: Left ventricular (LV) reconstruction surgery leads to early improvement in LV function in ischemic cardiomyopathy (ICM) patients. This study was designed to evaluate the impact of mitral valve (MV) repair associated with LV reconstruction on LV function 1-year after surgery in ICM patients assessed by real-time 3-dimensional echocardiography (3DE). METHODS AND RESULTS: Sixty ICM patients who underwent the combination surgery (LV reconstruction in 60, MV repair in 30, and revascularization in 52 patients) were studied. Real-time 3DE was performed and LV volumes were obtained at baseline, discharge, 6-month and >or=12-month follow-up. Reduction in end-diastolic volumes (EDV) by 29% and in end-systolic volumes by 38% were demonstrated immediately after surgery and remained at subsequent follow-up (P<0.0001). The LV ejection fraction significantly increased by about 10% at discharge and was maintained >or=12-month (P<0.0001). Although the LV volumes were significantly larger in patients with MV repair before surgery (EDV, 235+/-87 mL versus 193+/-67 mL, P<0.05), they were similar to LV volumes of the patients without MV repair at subsequent follow-ups. However, the EDV increased from 139+/-24 mL to 227+/-79 mL (P<0.01) in 7 patients with recurrent mitral regurgitation (MR). Improvement in New York Heart Association functional class occurred in 81% patients during late follow-up. CONCLUSIONS: Real-time 3DE demonstrates that LV reconstruction provides significant reduction in LV volumes and improvement in LV function which is sustained throughout the 1-year follow-up with 84% cardiac event free survival. If successful, MV repair may prevent LV redilation, while recurrent MR is associated with increased LV volumes.

  13. Camera-based three-dimensional real-time particle tracking at kHz rates and Ångström accuracy

    PubMed Central

    Daldrop, Peter; Joo, Sihwa; Otto, Oliver; Keyser, Ulrich F.; Seidel, Ralf

    2014-01-01

    Optical and magnetic tweezers are widely employed to probe the mechanics and activity of individual biomolecular complexes. They rely on micrometer-sized particles to detect molecular conformational changes from the particle position. Real-time particle tracking with Ångström accuracy has so far been only achieved using laser detection through photodiodes. Here we demonstrate that camera-based imaging can provide a similar performance for all three dimensions. Particle imaging at kHz rates is combined with real-time data processing being accelerated by a graphics processing unit. For particles that are fixed in the sample cell we can detect 3 Å sized steps that are introduced by cell translations at rates of 10 Hz, while for DNA-tethered particles 5 Å steps at 1 Hz can be resolved. Moreover, 20 particles can be tracked in parallel with comparable accuracy. Our approach provides a simple and robust way for high-resolution tweezers experiments using multiple particles at a time. PMID:25565216

  14. Respiratory function monitoring using a real-time three-dimensional fiber-optic shaping sensing scheme based upon fiber Bragg gratings

    NASA Astrophysics Data System (ADS)

    Allsop, Thomas; Bhamber, Ranjeet; Lloyd, Glynn; Miller, Martin R.; Dixon, Andrew; Webb, David; Ania Castañón, Juan Diego; Bennion, Ian

    2012-11-01

    An array of in-line curvature sensors on a garment is used to monitor the thoracic and abdominal movements of a human during respiration. The results are used to obtain volumetric changes of the human torso in agreement with a spirometer used simultaneously at the mouth. The array of 40 in-line fiber Bragg gratings is used to produce 20 curvature sensors at different locations, each sensor consisting of two fiber Bragg gratings. The 20 curvature sensors and adjoining fiber are encapsulated into a low-temperature-cured synthetic silicone. The sensors are wavelength interrogated by a commercially available system from Moog Insensys, and the wavelength changes are calibrated to recover curvature. A three-dimensional algorithm is used to generate shape changes during respiration that allow the measurement of absolute volume changes at various sections of the torso. It is shown that the sensing scheme yields a volumetric error of 6%. Comparing the volume data obtained from the spirometer with the volume estimated with the synchronous data from the shape-sensing array yielded a correlation value 0.86 with a Pearson's correlation coefficient p<0.01.

  15. Using digital image correlation and three dimensional point tracking in conjunction with real time operating data expansion techniques to predict full-field dynamic strain

    NASA Astrophysics Data System (ADS)

    Avitabile, Peter; Baqersad, Javad; Niezrecki, Christopher

    2014-05-01

    Large structures pose unique difficulties in the acquisition of measured dynamic data with conventional techniques that are further complicated when the structure also has rotating members such as wind turbine blades and helicopter blades. Optical techniques (digital image correlation and dynamic point tracking) are used to measure line of sight data without the need to contact the structure, eliminating cumbersome cabling issues. The data acquired from these optical approaches are used in conjunction with a unique real time operating data expansion process to obtain full-field dynamic displacement and dynamic strain. The measurement approaches are described in this paper along with the expansion procedures. The data is collected for a single blade from a wind turbine and also for a three bladed assembled wind turbine configuration. Measured strains are compared to results from a limited set of optical measurements used to perform the expansion to obtain full-field strain results including locations that are not available from the line of sight measurements acquired. The success of the approach clearly shows that there are some very extraordinary possibilities that exist to provide very desperately needed full field displacement and strain information that can be used to help identify the structural health of structures.

  16. Time-Domain Simulation of Three Dimensional Quantum Wires.

    PubMed

    Sullivan, Dennis M; Mossman, Sean; Kuzyk, Mark G

    2016-01-01

    A method is presented to calculate the eigenenergies and eigenfunctions of quantum wires. This is a true three-dimensional method based on a direct implementation of the time-dependent Schrödinger equation. It makes no approximations to the Schrödinger equation other than the finite-difference approximation of the space and time derivatives. The accuracy of our method is tested by comparing it to analytical results in a cylindrical wire. PMID:27124603

  17. Time-Domain Simulation of Three Dimensional Quantum Wires

    PubMed Central

    Mossman, Sean; Kuzyk, Mark G.

    2016-01-01

    A method is presented to calculate the eigenenergies and eigenfunctions of quantum wires. This is a true three-dimensional method based on a direct implementation of the time-dependent Schrödinger equation. It makes no approximations to the Schrödinger equation other than the finite-difference approximation of the space and time derivatives. The accuracy of our method is tested by comparing it to analytical results in a cylindrical wire. PMID:27124603

  18. Geometric differences of the mitral apparatus between ischemic and dilated cardiomyopathy with significant mitral regurgitation: real-time three-dimensional echocardiography study

    NASA Technical Reports Server (NTRS)

    Kwan, Jun; Shiota, Takahiro; Agler, Deborah A.; Popovic, Zoran B.; Qin, Jian Xin; Gillinov, Marc A.; Stewart, William J.; Cosgrove, Delos M.; McCarthy, Patrick M.; Thomas, James D.

    2003-01-01

    BACKGROUND: This study was conducted to elucidate the geometric differences of the mitral apparatus in patients with significant mitral regurgitation caused by ischemic cardiomyopathy (ICM-MR) and by idiopathic dilated cardiomyopathy (DCM-MR) by use of real-time 3D echocardiography (RT3DE). METHODS AND RESULTS: Twenty-six patients with ICM-MR caused by posterior infarction, 18 patients with DCM-MR, and 8 control subjects were studied. With the 3D software, commissure-commissure plane and 3 perpendicular anteroposterior (AP) planes were generated for imaging the medial, central, and lateral sides of the mitral valve (MV) during mid systole. In 3 AP planes, the angles between the annular plane and each leaflet (anterior, Aalpha; posterior, Palpha) were measured. In ICM-MR, Aalpha measured in the medial and central planes was significantly larger than that in the lateral plane (39+/-5 degrees, 34+/-6 degrees, and 27+/-5 degrees, respectively; P<0.01), whereas Palpha showed no significant difference in any of the 3 AP planes (61+/-7 degrees, 57+/-7 degrees, and 56+/-7 degrees, P>0.05). In DCM-MR, both Aalpha (38+/-8 degrees, 37+/-9 degrees, and 36+/-7 degrees, P>0.05) and Palpha (59+/-6 degrees, 58+/-5 degrees, and 57+/-6 degrees, P>0.05) revealed no significant differences in the 3 planes. CONCLUSIONS: The pattern of MV deformation from the medial to the lateral side was asymmetrical in ICM-MR, whereas it was symmetrical in DCM-MR. RT3DE is a helpful tool for differentiating the geometry of the mitral apparatus between these 2 different types of functional mitral regurgitation.

  19. Three-Dimensional Rotation, Twist and Torsion Analyses Using Real-Time 3D Speckle Tracking Imaging: Feasibility, Reproducibility, and Normal Ranges in Pediatric Population

    PubMed Central

    Han, Wei; Gao, Jun; He, Lin; Yang, Yali; Yin, Ping; Xie, Mingxing; Ge, Shuping

    2016-01-01

    Background and Objective The specific aim of this study was to evaluate the feasibility, reproducibility and maturational changes of LV rotation, twist and torsion variables by real-time 3D speckle-tracking echocardiography (RT3DSTE) in children. Methods A prospective study was conducted in 347 consecutive healthy subjects (181 males/156 females, mean age 7.12 ± 5.3 years, and range from birth to 18-years) using RT 3D echocardiography (3DE). The LV rotation, twist and torsion measurements were made off-line using TomTec software. Manual landmark selection and endocardial border editing were performed in 3 planes (apical “2”-, “4”-, and “3”- chamber views) and semi-automated tracking yielded LV rotation, twist and torsion measurements. LV rotation, twist and torsion analysis by RT 3DSTE were feasible in 307 out of 347 subjects (88.5%). Results There was no correlation between rotation or twist and age, height, weight, BSA or heart rate, respectively. However, there was statistically significant, but very modest correlation between LV torsion and age (R2 = 0.036, P< 0.001). The normal ranges were defined for rotation and twist in this cohort, and for torsion for each age group. The intra-observer and inter-observer variabilities for apical and basal rotation, twist and torsion ranged from 7.3% ± 3.8% to 12.3% ± 8.8% and from 8.8% ± 4.6% to 15.7% ± 10.1%, respectively. Conclusions We conclude that analysis of LV rotation, twist and torsion by this new RT3D STE is feasible and reproducible in pediatric population. There is no maturational change in rotation and twist, but torsion decreases with age in this cohort. Further refinement is warranted to validate the utility of this new methodology in more sensitive and quantitative evaluation of congenital and acquired heart diseases in children. PMID:27427968

  20. Single-pixel three-dimensional imaging with time-based depth resolution

    NASA Astrophysics Data System (ADS)

    Sun, Ming-Jie; Edgar, Matthew P.; Gibson, Graham M.; Sun, Baoqing; Radwell, Neal; Lamb, Robert; Padgett, Miles J.

    2016-07-01

    Time-of-flight three-dimensional imaging is an important tool for applications such as object recognition and remote sensing. Conventional time-of-flight three-dimensional imaging systems frequently use a raster scanned laser to measure the range of each pixel in the scene sequentially. Here we show a modified time-of-flight three-dimensional imaging system, which can use compressed sensing techniques to reduce acquisition times, whilst distributing the optical illumination over the full field of view. Our system is based on a single-pixel camera using short-pulsed structured illumination and a high-speed photodiode, and is capable of reconstructing 128 × 128-pixel resolution three-dimensional scenes to an accuracy of ~3 mm at a range of ~5 m. Furthermore, by using a compressive sampling strategy, we demonstrate continuous real-time three-dimensional video with a frame-rate up to 12 Hz. The simplicity of the system hardware could enable low-cost three-dimensional imaging devices for precision ranging at wavelengths beyond the visible spectrum.

  1. Single-pixel three-dimensional imaging with time-based depth resolution.

    PubMed

    Sun, Ming-Jie; Edgar, Matthew P; Gibson, Graham M; Sun, Baoqing; Radwell, Neal; Lamb, Robert; Padgett, Miles J

    2016-01-01

    Time-of-flight three-dimensional imaging is an important tool for applications such as object recognition and remote sensing. Conventional time-of-flight three-dimensional imaging systems frequently use a raster scanned laser to measure the range of each pixel in the scene sequentially. Here we show a modified time-of-flight three-dimensional imaging system, which can use compressed sensing techniques to reduce acquisition times, whilst distributing the optical illumination over the full field of view. Our system is based on a single-pixel camera using short-pulsed structured illumination and a high-speed photodiode, and is capable of reconstructing 128 × 128-pixel resolution three-dimensional scenes to an accuracy of ∼3 mm at a range of ∼5 m. Furthermore, by using a compressive sampling strategy, we demonstrate continuous real-time three-dimensional video with a frame-rate up to 12 Hz. The simplicity of the system hardware could enable low-cost three-dimensional imaging devices for precision ranging at wavelengths beyond the visible spectrum. PMID:27377197

  2. Real-time two- and three-dimensional imaging of monocyte motility and navigation on planar surfaces and in collagen matrices: roles of Rho

    PubMed Central

    Bzymek, Robert; Horsthemke, Markus; Isfort, Katrin; Mohr, Simon; Tjaden, Kerstin; Müller-Tidow, Carsten; Thomann, Marlies; Schwerdtle, Tanja; Bähler, Martin; Schwab, Albrecht; Hanley, Peter J.

    2016-01-01

    We recently found that macrophages from RhoA/RhoB double knockout mice had increased motility of the cell body, but severely impaired retraction of the tail and membrane extensions, whereas RhoA- or RhoB-deficient cells exhibited mild phenotypes. Here we extended this work and investigated the roles of Rho signaling in primary human blood monocytes migrating in chemotactic gradients and in various settings. Monocyte velocity, but not chemotactic navigation, was modestly dependent on Rho-ROCK-myosin II signaling on a 2D substrate or in a loose collagen type I matrix. Viewed by time-lapse epi-fluorescence microscopy, monocytes appeared to flutter rather than crawl, such that the 3D surface topology of individual cells was difficult to predict. Spinning disk confocal microscopy and 3D reconstruction revealed that cells move on planar surfaces and in a loose collagen matrix using prominent, curved planar protrusions, which are rapidly remodeled and reoriented, as well as resorbed. In a dense collagen type I matrix, there is insufficient space for this mode and cells adopt a highly Rho-dependent, lobular mode of motility. Thus, in addition to its role in tail retraction on 2D surfaces, Rho is critical for movement in confined spaces, but is largely redundant for motility and chemotaxis in loose matrices. PMID:27122054

  3. Real-time two- and three-dimensional imaging of monocyte motility and navigation on planar surfaces and in collagen matrices: roles of Rho.

    PubMed

    Bzymek, Robert; Horsthemke, Markus; Isfort, Katrin; Mohr, Simon; Tjaden, Kerstin; Müller-Tidow, Carsten; Thomann, Marlies; Schwerdtle, Tanja; Bähler, Martin; Schwab, Albrecht; Hanley, Peter J

    2016-01-01

    We recently found that macrophages from RhoA/RhoB double knockout mice had increased motility of the cell body, but severely impaired retraction of the tail and membrane extensions, whereas RhoA- or RhoB-deficient cells exhibited mild phenotypes. Here we extended this work and investigated the roles of Rho signaling in primary human blood monocytes migrating in chemotactic gradients and in various settings. Monocyte velocity, but not chemotactic navigation, was modestly dependent on Rho-ROCK-myosin II signaling on a 2D substrate or in a loose collagen type I matrix. Viewed by time-lapse epi-fluorescence microscopy, monocytes appeared to flutter rather than crawl, such that the 3D surface topology of individual cells was difficult to predict. Spinning disk confocal microscopy and 3D reconstruction revealed that cells move on planar surfaces and in a loose collagen matrix using prominent, curved planar protrusions, which are rapidly remodeled and reoriented, as well as resorbed. In a dense collagen type I matrix, there is insufficient space for this mode and cells adopt a highly Rho-dependent, lobular mode of motility. Thus, in addition to its role in tail retraction on 2D surfaces, Rho is critical for movement in confined spaces, but is largely redundant for motility and chemotaxis in loose matrices. PMID:27122054

  4. Three-dimensional flushing times of the Persian Gulf

    NASA Astrophysics Data System (ADS)

    Sadrinasab, Masoud; Kämpf, Jochen

    2004-12-01

    A three-dimensional hydrodynamic model is employed in a fully prognostic mode to derive flushing times of the Persian Gulf-an evaporation-driven inverse estuary that is governed by import of surface water from the adjacent ocean and export of saline bottom gulf water through the Strait of Hormuz. During spring and summer, a cyclonic overturning circulation establishes along the full length of the Gulf. During autumn and winter, this circulation breaks up into mesoscale eddies, laterally stirring most of the Gulf's surface waters. As a result of this, 95% flushing times of surface waters are shortest (1-3 yr, increasing with distance from the Strait) along the Iranian coast, but are much longer (>5 yr) along the coasts of Kuwait and Saudi Arabia. Owing to density stratification introduced by the surface inflow of ocean water, flushing times of bottom waters are ~6 yr in most parts of the Gulf.

  5. Deployment of a three-dimensional array of Micro-Pocket Fission Detector triads (MPFD3) for real-time, in-core neutron flux measurements in the Kansas State University TRIGA Mark-II Nuclear Reactor

    NASA Astrophysics Data System (ADS)

    Ohmes, Martin Francis

    A Micro-Pocket Fission Detector (MPFD) is a miniaturized type of fission chamber developed for use inside a nuclear reactor. Their unique design allows them to be located between or even inside fuel pins while being built from materials which give them an operational lifetime comparable to or exceeding the life of the fuel. While other types of neutron detectors have been made for use inside a nuclear reactor, the MPFD is the first neutron detector which can survive sustained use inside a nuclear reactor while providing a real-time measurement of the neutron flux. This dissertation covers the deployment of MPFDs as a large three-dimensional array inside the Kansas State University TRIGA Mark-II Nuclear Reactor for real-time neutron flux measurements. This entails advancements in the design, construction, and packaging of the Micro-Pocket Fission Detector Triads with incorporated Thermocouple, or MPFD3-T. Specialized electronics and software also had to be designed and built in order to make a functional system capable of collecting real-time data from up to 60 MPFD3-Ts, or 180 individual MPFDs and 60 thermocouples. Design of the electronics required the development of detailed simulations and analysis for determining the theoretical response of the detectors and determination of their size. The results of this research shows that MPFDs can operate for extended times inside a nuclear reactor and can be utilized toward the use as distributed neutron detector arrays for advanced reactor control systems and power mapping. These functions are critical for continued gains in efficiency of nuclear power reactors while also improving safety through relatively inexpensive redundancy.

  6. Directional ocean spectra by three-dimensional displacement time series

    SciTech Connect

    Su, T.Z.

    1984-01-01

    The directionality of ocean waves is considered as the most problem area of today's wave measurement technology. In 1982 the University of Hawaii Ocean ''Engineering Department began a research project Engineering Development of a Directional Wave Spectrum Measurement System for OTEC Applications'' to address this problem. A new technology was developed in this research. This technology uses acoustic signals to determine the trajectory of a floating buoy which simulates the movement of a surface water particle. Transfer functions of the three-dimensional displacement time series are used to describe the wave kinematics. The described wave kinematics are directly applied to calculate hydrodynamic loading. Cospectra and quadrature spectra determine the directional distribution function. The resultant directional distribution function is used to predict the directional progression of ocean waves.

  7. Lightness identification of patterned three-dimensional, real objects

    PubMed Central

    Robilotto, Rocco; Zaidi, Qasim

    2010-01-01

    Conventional studies of lightness constancy have almost exclusively used flat plain stimuli and have shown that lightness matches across illuminants cannot be explained by physical matches of reflectance or luminance. The perceptual qualities that underlie lightness judgments still remain largely unknown. Real objects are often 3-D and patterned, giving additional cues for identification. We examine the perceptual strategies that underlie material identification of real objects. Stimuli were randomly crumpled papers printed with achromatic patterns with precisely calibrated mean reflectance and reflectance contrast, placed in backgrounds under varying levels of illumination. Observers were asked to identify objects based on physical reflectance differences. Reflectance identification functions were simulated by simple models that perform object identification based on dissimilarities in perceived brightness (luminance dissimilarity modified by light adaptation) or perceived contrast (contrast dissimilarity modified by mean luminance). The reflectance identification results were also recreated in two control experiments, using identical stimuli conditions, where choices were based explicitly on dissimilarities in perceived brightness or contrast. Rather than a reverse optics model of lightness perception where observers first estimate illuminant intensity and then extract relative lightness by discounting the illuminant, this study supports the use of simple percepts such as brightness and contrast. PMID:16489856

  8. New techniques in television to provide research in three-dimensional real-time or near real-time imagery and reduced cost systems for teleconferencing and educational uses, part 1

    NASA Technical Reports Server (NTRS)

    Pao, Y. H.; Claspy, P.; Allen, J. E.; Merat, F.

    1979-01-01

    The results are presented of a continuing research and development program the objective of which is to develop a reduced bandwidth television system and a technique for television transmission of holograms. The result of the former is a variable frame rate television system, the operation of which was demonstrated for both black-and-white and color signals. This system employs a novel combination of the inexpensive mass storage capacity of a magnetic disc with the reliability of a digital system for time expansion and compression. Also reported are the results of a theoretical analysis and preliminary feasibility experiment of an innovative system for television transmission of holograms using relatively conventional TV equipment along with a phase modulated reference wave for production of the original interference pattern.

  9. Double-label confocal laser-scanning microscopy, image restoration, and real-time three-dimensional reconstruction to study axons in the central nervous system and their contacts with target neurons.

    PubMed

    Wouterlood, Floris G; van Haeften, Theo; Blijleven, Nico; Pérez-Templado, Pepa; Pérez-Templado, Helena

    2002-03-01

    The current double tracing-double confocal laser-scanning method was developed to reconstruct identified nerve fibers and their contacts with identified target neurons in the rat brain in three dimensions. It intends to fill the gap between conventional light microscopic and electron microscopic neuroanatomic tracing. The steps involved are as follows: (1) injection of two neuroanatomic tracers--Phaseolus vulgaris leucoagglutinin (PHA-L) to label fibers innervating a particular brain area and Neurobiotin to label prospective target neurons in that area; (2) immunofluorescence detection of the labeled fibers (fluorophore Cy5, infrared emission), together with fluorochromated avidin detection of the taken-up Neurobiotin (Cy2 or Alexa 488; green emission); (3) acquisition of Z-series of confocal images at high magnification with a laser-scanning microscope using the laser lines 488 nm and 647 nm; and (4) computer-processing and three-dimensional reconstruction of the labeled fibers and the presumed target dendrites. Rotation on the computer of the three-dimensional reconstructed fibers and dendrites along all three spatial axes enabled the authors to determine whether "true" or "false" contacts occur. In a true contact no space was present between the apposing structures, whereas a false contact consisted of two differently stained structures close to each other but separated by a narrow, optically empty space. One important phenomenon in the three-dimensional reconstruction of double-stained structures that needed correction was "twin image mismatch"--i.e., the observation that a three-dimensional reconstruction of a small test object (double-stained on purpose) produced two slightly shifted objects, each associated with its particular fluorochrome. To measure the actual twin image mismatch of the confocal instrument and to obtain accurate correction factors the authors took in each session in which they obtained image series of the real experiments, with both laser

  10. Three-Dimensional Numerical Modeling of Initial Mixing of Thermal Discharges at Real-Life Configurations

    SciTech Connect

    Tang, Hansong; Paik, Joongcheol; Sotiropoulos, Fotis; Khangaonkar, Tarang P.

    2008-09-01

    A three-dimensional Reynolds-averaged Navier-Stokes (RANS) computational fluid dynamics (CFD) model is developed for simulating turbulent mixing in the near-field of thermal discharge at real-life geometrical configurations. The domain decomposition method with the multi-level embedded overset grids is employed to handle the complexity of real-life diffusers as well as to efficiently account for the large disparity of length scales arising from the relative size of the ambient river reach and the typical diffuser diameter.

  11. Three-dimensional time reversal communications in elastic media.

    PubMed

    Anderson, Brian E; Ulrich, Timothy J; Le Bas, Pierre-Yves; Ten Cate, James A

    2016-02-01

    This letter presents a series of vibrational communication experiments, using time reversal, conducted on a set of cast iron pipes. Time reversal has been used to provide robust, private, and clean communications in many underwater acoustic applications. Here the use of time reversal to communicate along sections of pipes and through a wall is demonstrated to overcome the complications of dispersion and multiple scattering. These demonstrations utilize a single source transducer and a single sensor, a triaxial accelerometer, enabling multiple channels of simultaneous communication streams to a single location. PMID:26936580

  12. Three-dimensional time reversal communications in elastic media

    DOE PAGESBeta

    Anderson, Brian E.; Ulrich, Timothy J.; Le Bas, Pierre-Yves; Ten Cate, James A.

    2016-02-23

    Our letter presents a series of vibrational communication experiments, using time reversal, conducted on a set of cast iron pipes. Time reversal has been used to provide robust, private, and clean communications in many underwater acoustic applications. Also, the use of time reversal to communicate along sections of pipes and through a wall is demonstrated here in order to overcome the complications of dispersion and multiple scattering. These demonstrations utilize a single source transducer and a single sensor, a triaxial accelerometer, enabling multiple channels of simultaneous communication streams to a single location.

  13. Method for producing three-dimensional real image using radiographic perspective views of an object

    DOEpatents

    Ellingson, William A.; Read, Alvin A.

    1976-02-24

    A sequence of separate radiographs are made by indexing a radiation source along a known path relative to the object under study. Thus, each radiograph contains information from a different perspective. A holographically-recorded image is then made from each radiographic perspective by exact re-tracing of the rays through each radiographic perspective such that the re-tracing duplicates the geometry under which it was originally prepared. The holographically-stored images are simultaneously illuminated with the conjugate of the reference beam used in the original recordings. The result is the generation of a three-dimensional real image of the object such that a light-sensitive device can be moved to view the real image along any desired surface with the optical information in all other surfaces greatly suppressed.

  14. Model calculations for three-dimensional heat conduction in a real tooth

    NASA Astrophysics Data System (ADS)

    Foth, Hans-Jochen; Luke, Manfred

    2003-06-01

    To generate the three-dimensional grid net for a real tooth, an extracted tooth was grinded in steps of some millimetres from the top to the root. After each grinding step the displayed cross section was documented by photography showing clearly all transition lines between enamel, dentin and the pulp. The photographic reprints were used to determine the x-y-z-coordinates of selected points to represent the transition lines. In a fairly large-scale procedure these points were combined to a three dimensional net. FEM calculations were carried out to solve the heat equation numerically for the boundary condition that an IR laser pulse hits the surface for laser ablation. Since all the information of the various types of tissue is included in this model, the results give a huge variety of information. For example: the outer shell of enamel could be displayed exclusively to show its inner surface and which temperature distribution as well as mechanical stress got build up there.

  15. Numerical computation of multishocked, three-dimensional supersonic flow fields with real gas effects.

    NASA Technical Reports Server (NTRS)

    Kutler, P.; Reinhardt, W. A.; Warming, R. F.

    1972-01-01

    A computational procedure is presented which is capable of determining the supersonic flow field surrounding three-dimensional wing-body configurations such as a delta-wing space shuttle. The governing equations in conservation-law form are solved by a finite difference method using a second-order noncentered algorithm between the body and the outermost shock wave, which is treated as a sharp discontinuity. Secondary shocks which form between these boundaries are captured automatically, and the intersection of these shocks with the bow shock posed no difficulty. Resulting flow fields about typical blunt nose shuttle-like configurations at angle of attack are presented. The differences between perfect and real gas effects for high Mach number flows are shown.

  16. Three-dimensional time-marching inviscid and viscous solutions for unsteady flows around vibrating blades

    SciTech Connect

    He, L.; Denton, J.D. . Whittle Lab.)

    1994-07-01

    A three-dimensional nonlinear time-marching method of solving the thin-layer Navier-Stokes equations in a simplified form has been developed for blade flutter calculations. The discretization of the equations is made using the cell-vertex finite volume scheme in space and the four-stage Runge-Kutta scheme in time. Calculations are carried out in a single-blade-passage domain and the phase-shifted periodic condition is implemented by using the shape correction method. The three-dimensional unsteady Euler solution is obtained at conditions of zero viscosity, and is validated against a well-established three-dimensional semi-analytical method. For viscous solutions, the time-step limitation on the explicit temporal discretization scheme is effectively relaxed by using a time-consistent two-grid time-marching technique. A transonic rotor blade passage flow (with tip-leakage) is calculated using the present three-dimensional unsteady viscous solution method. Calculated steady flow results agree well with the corresponding experiment and with other calculations. Calculated unsteady loadings due to oscillations of the rotor blades reveal some notable three-dimensional viscous flow features. The feasibility of solving the simplified thin-layer Navier-Stokes solver for oscillating blade flows at practical conditions is demonstrated.

  17. Three-dimensional imaging and display of real-existing scene using fringe

    NASA Astrophysics Data System (ADS)

    Li, Yong; Wang, Hui; Ma, Lihong; Shi, Yile

    2013-06-01

    Holography, in which three-dimensional (3D) information and texture of object is encoded with interference fringe is a promising approach for 3D display. However, it is challenge to make photographic hologram of living object. In addition, it is impossible to record scene combining real-existing objects with virtual ones using photographic holography. In this paper, we propose a method for capturing and displaying 3D real-existing scene. Firstly, the 3D shape and color texture of scene is captured with fringe projection method. Secondly, the information of scene is encoded with computer generated fringe, which is called Computer-generated Hologram (CGH). Finally, the CGH is materialize as hardcopy or transferred to spatial light modulator (SLM) for display. The real-color Rainbow-hologram is chosen for display static scene. Three Fresnel holograms corresponding to red, green and blue component of scene are adopted for display dynamic scene. The apparatuses for 3D capture and display are introduced and the experimental results are demonstrated.

  18. Comparisons between real and complex Gauss wavelet transform methods of three-dimensional shape reconstruction

    NASA Astrophysics Data System (ADS)

    Xu, Luopeng; Dan, Youquan; Wang, Qingyuan

    2015-10-01

    The continuous wavelet transform (CWT) introduces an expandable spatial and frequency window which can overcome the inferiority of localization characteristic in Fourier transform and windowed Fourier transform. The CWT method is widely applied in the non-stationary signal analysis field including optical 3D shape reconstruction with remarkable performance. In optical 3D surface measurement, the performance of CWT for optical fringe pattern phase reconstruction usually depends on the choice of wavelet function. A large kind of wavelet functions of CWT, such as Mexican Hat wavelet, Morlet wavelet, DOG wavelet, Gabor wavelet and so on, can be generated from Gauss wavelet function. However, so far, application of the Gauss wavelet transform (GWT) method (i.e. CWT with Gauss wavelet function) in optical profilometry is few reported. In this paper, the method using GWT for optical fringe pattern phase reconstruction is presented first and the comparisons between real and complex GWT methods are discussed in detail. The examples of numerical simulations are also given and analyzed. The results show that both the real GWT method along with a Hilbert transform and the complex GWT method can realize three-dimensional surface reconstruction; and the performance of reconstruction generally depends on the frequency domain appearance of Gauss wavelet functions. For the case of optical fringe pattern of large phase variation with position, the performance of real GWT is better than that of complex one due to complex Gauss series wavelets existing frequency sidelobes. Finally, the experiments are carried out and the experimental results agree well with our theoretical analysis.

  19. Three-dimensional time and Fourier domain endoscopic OCT using 2-axis scanning MEMS mirror

    NASA Astrophysics Data System (ADS)

    Jung, Woonggyu; McCormick, Daniel T.; Ahn, Yeh-Chan; Zhang, Jun; Tien, Norman C.; Chen, Zhongping

    2006-02-01

    We present a three-dimensional (3-D) endoscopic optical coherence tomography (OCT) system based on a dual axis microelectromechanical system (MEMS) mirror. The diameter of MEMS mirror was 1.2 mm and both axes were capable of scanning up to 20° (optical) at greater than 1 kHz with excellent linearity. The MEMS mirror was packaged in a machined acrylic endoscopic housing which provided mechanical protection and electrical interconnects as well as optical alignment of the MEMS device to a focusing GRIN lens. The endoscopic MEMS probe was integrated and tested with both a fiber-based time domain (TD) OCT system and Fourier domain (FD) OCT system. Combining the 2-axis lateral scanning of the MEMS device with an axial scan allowed 3-D volume images to be obtained at a rate of 3 frames/s for the TD system and 7 frames/s for the FD system. In the initial investigations, in vivo 3-D OCT images of a human finger as well as images of animal tissue such as healthy rabbit trachea, normal and cancerous regions of hamster cheek pouch tissue were obtained. These images allowed real-time diagnosis of diseased tissue and also clearly delineated important features and tissue structures.

  20. Energy management of three-dimensional minimum-time intercept. [for aircraft flight optimization

    NASA Technical Reports Server (NTRS)

    Kelley, H. J.; Cliff, E. M.; Visser, H. G.

    1985-01-01

    A real-time computer algorithm to control and optimize aircraft flight profiles is described and applied to a three-dimensional minimum-time intercept mission. The proposed scheme has roots in two well known techniques: singular perturbations and neighboring-optimal guidance. Use of singular-perturbation ideas is made in terms of the assumed trajectory-family structure. A heading/energy family of prestored point-mass-model state-Euler solutions is used as the baseline in this scheme. The next step is to generate a near-optimal guidance law that will transfer the aircraft to the vicinity of this reference family. The control commands fed to the autopilot (bank angle and load factor) consist of the reference controls plus correction terms which are linear combinations of the altitude and path-angle deviations from reference values, weighted by a set of precalculated gains. In this respect the proposed scheme resembles neighboring-optimal guidance. However, in contrast to the neighboring-optimal guidance scheme, the reference control and state variables as well as the feedback gains are stored as functions of energy and heading in the present approach. Some numerical results comparing open-loop optimal and approximate feedback solutions are presented.

  1. Development of a three-dimensional time-dependent flow field model

    NASA Technical Reports Server (NTRS)

    Farmer, R. C.; Waldrop, W. R.; Pitts, F. H.; Shah, K. R.

    1975-01-01

    A three-dimensional, time-dependent mathematical model to represent Mobile Bay was developed. Computer programs were developed which numerically solve the appropriate conservation equations for predicting bay and estuary flow fields. The model is useful for analyzing the dispersion of sea water into fresh water and the transport of sediment, and for relating field and physical model data.

  2. Real Stereopsis Test Using a Three-Dimensional Display with Tridef Software

    PubMed Central

    Han, Jinu; Han, So Young; Lee, Seung Koo; Lee, Jong Bok

    2014-01-01

    Purpose To investigate horizontal image disparity in three-dimensional (3-D) perception using 3-D animations in normal control patients and patients with intermittent exotropia, anisometropic amblyopia, and partially accommodative esotropia. Materials and Methods A total of 133 subjects were included. Stereopsis was measured using the Titmus Stereo test (Stereo Optical Inc., Chicago, IL, USA) and a 3-D stereopsis test with a 15 inch 3-D display laptop, adjusting 3-D parameters of 0 mm horizontal disparity to 15 mm horizontal disparity. Results When compared with normal controls, the average threshold of the 3-D stereopsis test was significantly reduced for esotropia patients (p<0.001) and for anisometric amblyopia patients (p<0.001), compared to normal controls. No significant difference was observed between normal controls and intermittent exotropia patients (p=0.082). The 3-D stereopsis test was correlated with the Titmus Stereo test (Spearman's rho=0.690, p<0.001). Mean difference in stereoacuity was 1.323 log seconds of arc (95% limits of agreement: 0.486 to 2.112), and 125 (92.5%) patients were within the limits of agreement. Conclusion This study demonstrated that a 3-D stereopsis test with animation is highly correlated with the Titmus Stereo test; nevertheless, 3-D stereopsis with animations generates more image disparities than the conventional Titmus Stereo test. The 3-D stereopsis test is highly predictive for estimating real stereopsis in a 3-D movie theater. PMID:25323907

  3. Three-dimensional finite difference time domain modeling of the Earth-ionosphere cavity resonances

    NASA Astrophysics Data System (ADS)

    Yang, Heng; Pasko, Victor P.

    2005-02-01

    Comparison of results from a three-dimensional (3-D) finite difference time domain (FDTD) model of Schumann resonances (SR) with a set of classical eigenfrequency and quality factor solutions for laterally uniform spherically symmetric Earth-ionosphere cavity and recent SR observations during solar proton events (SPEs) and X-ray bursts demonstrate the potential and applicability of the FDTD technique for studies of realistic SR problems.

  4. Acetazolamide challenge for three-dimensional time-of-flight MR angiography of the brain

    SciTech Connect

    Mandai, Kenji; Sueyoshi, Kenji; Fukunaga, Ryuzo; Nukada, Masaru; Ohtani, Fumio; Araki, Yutaka; Tsukaguchi, Isao; Abe, Hiroshi )

    1994-04-01

    We compared three-dimensional time-of-flight MR angiograms obtained before and after acetazolamide administration to evaluate whether use of this drug could improve visualization of small peripheral intracranial arteries and atherosclerotic stenosis. For evaluation of small peripheral arteries, 10 patients with clinical diagnosis of ischemic cerebrovascular disease and 10 healthy volunteers were investigated, and for evaluation of stenosis, another 6 patients were investigated. Vascular images were obtained by three-dimensional time-of-flight MR angiography. After a baseline scan, 17 mg/kg acetazolamide was injected intravenously and the second scan was performed 20 minutes later. Several small peripheral arteries that had not been seen on the baseline images were visible on the acetazolamide images without any augmentation of the background signals. Stenotic lesions in the main trunks of the major cerebral arteries were detected more clearly on acetazolamide images. Acetazolamide improves visualization of small peripheral intracranial arteries and sensitivity in detecting atherosclerotic stenosis in the main trunk of major cerebral artery by three-dimensional time-of-flight MR angiography without changing MR apparatus and software. 15 refs., 5 figs., 2 tabs.

  5. A Three Dimensional Parallel Time Accurate Turbopump Simulation Procedure Using Overset Grid Systems

    NASA Technical Reports Server (NTRS)

    Kiris, Cetin; Chan, William; Kwak, Dochan

    2001-01-01

    The objective of the current effort is to provide a computational framework for design and analysis of the entire fuel supply system of a liquid rocket engine, including high-fidelity unsteady turbopump flow analysis. This capability is needed to support the design of pump sub-systems for advanced space transportation vehicles that are likely to involve liquid propulsion systems. To date, computational tools for design/analysis of turbopump flows are based on relatively lower fidelity methods. An unsteady, three-dimensional viscous flow analysis tool involving stationary and rotational components for the entire turbopump assembly has not been available for real-world engineering applications. The present effort provides developers with information such as transient flow phenomena at start up, and non-uniform inflows, and will eventually impact on system vibration and structures. In the proposed paper, the progress toward the capability of complete simulation of the turbo-pump for a liquid rocket engine is reported. The Space Shuttle Main Engine (SSME) turbo-pump is used as a test case for evaluation of the hybrid MPI/Open-MP and MLP versions of the INS3D code. CAD to solution auto-scripting capability is being developed for turbopump applications. The relative motion of the grid systems for the rotor-stator interaction was obtained using overset grid techniques. Unsteady computations for the SSME turbo-pump, which contains 114 zones with 34.5 million grid points, are carried out on Origin 3000 systems at NASA Ames Research Center. Results from these time-accurate simulations with moving boundary capability will be presented along with the performance of parallel versions of the code.

  6. A Three-Dimensional Parallel Time-Accurate Turbopump Simulation Procedure Using Overset Grid System

    NASA Technical Reports Server (NTRS)

    Kiris, Cetin; Chan, William; Kwak, Dochan

    2002-01-01

    The objective of the current effort is to provide a computational framework for design and analysis of the entire fuel supply system of a liquid rocket engine, including high-fidelity unsteady turbopump flow analysis. This capability is needed to support the design of pump sub-systems for advanced space transportation vehicles that are likely to involve liquid propulsion systems. To date, computational tools for design/analysis of turbopump flows are based on relatively lower fidelity methods. An unsteady, three-dimensional viscous flow analysis tool involving stationary and rotational components for the entire turbopump assembly has not been available for real-world engineering applications. The present effort provides developers with information such as transient flow phenomena at start up, and nonuniform inflows, and will eventually impact on system vibration and structures. In the proposed paper, the progress toward the capability of complete simulation of the turbo-pump for a liquid rocket engine is reported. The Space Shuttle Main Engine (SSME) turbo-pump is used as a test case for evaluation of the hybrid MPI/Open-MP and MLP versions of the INS3D code. CAD to solution auto-scripting capability is being developed for turbopump applications. The relative motion of the grid systems for the rotor-stator interaction was obtained using overset grid techniques. Unsteady computations for the SSME turbo-pump, which contains 114 zones with 34.5 million grid points, are carried out on Origin 3000 systems at NASA Ames Research Center. Results from these time-accurate simulations with moving boundary capability are presented along with the performance of parallel versions of the code.

  7. Three-dimensional vision for real-time produce grading

    NASA Astrophysics Data System (ADS)

    Bailey, Donald G.; Mercer, Ken; Plaw, Colin; Ball, Ralph; Barraclough, Harvey

    2002-02-01

    Produce is often sold by weight, so one of the roles of the grading system is to allocate each item to a particular chute for packing into fixed weight bundles. Accurate, high- speed weight measurement is difficult and expensive, so machine vision is used to estimate the weight of each item. Previous estimations relied on a single diameter measurement, which resulted in large errors. To ensure that the minimum weight was provided, each bundle was on average 30% overweight. By improving the accuracy of the estimation, and combining this with an improved chute allocation strategy, significant savings can be made. The weight estimation in the system under development is based on the projected area of each item. The error in weight estimation was further improved by measuring the projected area from two perpendicular views. With the produce being sorted at a rate of 12 to 15 items per second, there are significant challenges in obtaining and processing the simultaneous perpendicular views of each item. The two views are captured of the item through the use of mirrors, and a third direct view is also obtained for quality grading purposes.

  8. Nonlinear teleseismic tomography at Long Valley caldera, using three-dimensional minimum travel time ray tracing

    SciTech Connect

    Weiland, C.M.; Steck, L.K.; Dawson, P.B.

    1995-10-10

    The authors explore the impact of three-dimensional minimum travel time ray tracing on nonlinear teleseismic inversion. This problem has particular significance when trying to image strongly contrasting low-velocity bodies, such as magma chambers, because strongly refracted/and/or diffracted rays may precede the direct P wave arrival traditionally used in straight-ray seismic tomography. They use a simplex-based ray tracer to compute the three-dimensional, minimum travel time ray paths and employ an interative technique to cope with nonlinearity. Results from synthetic data show that their algorithm results in better model reconstructions compared with traditional straight-ray inversions. The authors reexamine the teleseismic data collected at Long Valley caldera by the U.S. Geological Survey. The most prominent feature of their result is a 25-30% low-velocity zone centered at 11.5 km depth beneath the northwestern quandrant of the caldera. Beneath this at a depth of 24.5 km is a more diffuse 15% low-velocity zone. In general, the low velocities tend to deepen to the south and east. The authors interpret the shallow feature to be the residual Long Valley caldera magma chamber, while the deeper feature may represent basaltic magmas ponded in the midcrust. The deeper position of the prominent low-velocity region in comparison to earlier tomographic images is a result of using three-dimensional rays rather than straight rays in the ray tracing. The magnitude of the low-velocity anomaly is a factor of {approximately}3 times larger than earlier models from linear arrival time inversions and is consistent with models based on observations of ray bending at sites within the caldera. These results imply the presence of anywhere from 7 to 100% partial melt beneath the caldera. 40 refs., 1 fig., 1 tab.

  9. Evolving a three-dimensional cellular automata dynamic system constituted of cells-charges for modelling real earthquake activity

    NASA Astrophysics Data System (ADS)

    Sirakoulis, G. Ch.

    2009-04-01

    Greece is referred as the most active seismically region of Europe and one of the top active lands in the world. However, the complexity of the available seismicity information calls for the development of ever more powerful and more reliable computational tools to tackle complex problems associated with proper interpretation of the obtained geophysical information. Cellular Automata (CAs) were showed to be a promising model for earthquake modelling, because certain aspects of the earthquake dynamics, function and evolution can be simulated using several mathematical tools introduced through the use of CAs. In this study, a three-dimensional (3-d) CA dynamic system constituted of cell-charges and taking into account the recorded focal depth, able to simulate real earthquake activity is presented. The whole simulation process of the earthquake activity is evolved with an LC analogue CA model in correspondence to well known earthquake models. The parameterisation of the CA model in terms of potential threshold and geophysical area characteristics is succeeded by applying a standard genetic algorithm (GA) which would extend the model ability to study various hypotheses concerning the seismicity of the region under consideration. As a result, the proposed model optimizes the simulation results, which are compared with the Gutenberg - Richter (GR) scaling relations derived by the use of real data, as well as it expands its validity in broader and different regions of increased hazard. Finally, the hardware implementation of the proposed model is also examined. The FPGA realisation of the proposed 3-d CA based earthquake simulation model will exhibit distinct features that facilitate its utilisation, meaning low-cost, high-speed, compactness and portability. The development and manufacture of the dedicated processor aims at its effective incorporation into an efficient seismographic system. As a result, the dedicated processor could realize the first stage of a

  10. A time-split finite-volume algorithm for three-dimensional flow-field simulation

    NASA Technical Reports Server (NTRS)

    Hung, C. M.; Kordulla, W.

    1983-01-01

    A general finite-volume algorithm is developed for solving three-dimensional, time-dependent, compressible Navier-Stokes equations for high Reynolds number flows over an arbitrary geometry. This algorithm adapts MacCormack's (1982) explicit-implicit scheme to a time-split, three-dimensional finite-volume concept in a general coordinate system. It is shown that the thin-layer approximation in all three spatial directions significantly reduces the evaluation of viscous terms and allows the algorithm to solve more complicated geometries with all boundaries in two or all three directions. The calculated results using this method are found to be in good agreement with the experimental measurements of a blunt-fin induced shock wave and boundary-layer interaction problems. Observations of the existence of peak pressure, primary horseshoe and secondary vortices, and reversed supersonic zones show that computational fluid dynamics can effectively supplement the wind tunnel tests for aerodynamic design as well as for understanding basic fluid dynamics.

  11. Three-dimensional sonoembryology.

    PubMed

    Benoit, Bernard; Hafner, Tomislav; Kurjak, Asim; Kupesić, Sanja; Bekavac, Ivanka; Bozek, Tomislav

    2002-01-01

    Three-dimensional (3D) ultrasound plays an important role in obstetrics, predominantly for assessing fetal anatomy. Presenting volume data in a standard anatomic orientation valuably assists both ultrasonographers and pregnant patients to recognize the anatomy more readily. Three-dimensional ultrasound is advantageous in studying normal embryonic and/or fetal development, as well as providing information for families at risk for specific congenital anomalies by confirming normality. This method offers advantages in assessing the embryo in the first trimester due to its ability to obtain multiplanar images through endovaginal volume acquisition. Rotation allows the systematic review of anatomic structures and early detection of fetal anomalies. Three-dimensional ultrasound imaging in vivo compliments pathologic and histologic evaluation of the developing embryo, giving rise to a new term: 3D sonoembryology. Rapid technological development will allow real-time 3D ultrasound to provide improved and expanded patient care on the one side, and increased knowledge of developmental anatomy on the other. PMID:11933658

  12. The distribution of “time of flight” in three dimensional stationary chaotic advection

    SciTech Connect

    Raynal, Florence; Carrière, Philippe

    2015-04-15

    The distributions of “time of flight” (time spent by a single fluid particle between two crossings of the Poincaré section) are investigated for five different three dimensional stationary chaotic mixers. Above all, we study the large tails of those distributions and show that mainly two types of behaviors are encountered. In the case of slipping walls, as expected, we obtain an exponential decay, which, however, does not scale with the Lyapunov exponent. Using a simple model, we suggest that this decay is related to the negative eigenvalues of the fixed points of the flow. When no-slip walls are considered, as predicted by the model, the behavior is radically different, with a very large tail following a power law with an exponent close to −3.

  13. Three-dimensional time-marching aeroelastic analyses using an unstructured-grid Euler method

    NASA Technical Reports Server (NTRS)

    Rausch, Russ D.; Batina, John T.; Yang, Henry T. Y.

    1992-01-01

    Modifications to a three dimensional, implicit, upwind, unstructured-grid Euler code for aeroelastic analysis of complete aircraft configurations are described. The modifications involve the addition of the structural equations of motion for their simultaneous time integration with the governing flow equations. The paper presents a detailed description of the time marching aeroelastic procedure and presents comparisons with experimental data to provide an assessment of the capability. Flutter results are shown for an isolated 45 degree swept-back wing and a supersonic transport configuration with a fuselage, clipped delta wing, and two identical rearward-mounted nacelles. Comparisons between computed and experimental flutter characteristics show good agreement, giving confidence in the accuracy of the aeroelastic capability that was developed.

  14. The distribution of "time of flight" in three dimensional stationary chaotic advection

    NASA Astrophysics Data System (ADS)

    Raynal, Florence; Carrière, Philippe

    2015-04-01

    The distributions of "time of flight" (time spent by a single fluid particle between two crossings of the Poincaré section) are investigated for five different three dimensional stationary chaotic mixers. Above all, we study the large tails of those distributions and show that mainly two types of behaviors are encountered. In the case of slipping walls, as expected, we obtain an exponential decay, which, however, does not scale with the Lyapunov exponent. Using a simple model, we suggest that this decay is related to the negative eigenvalues of the fixed points of the flow. When no-slip walls are considered, as predicted by the model, the behavior is radically different, with a very large tail following a power law with an exponent close to -3.

  15. Study of High Robust Three Dimensional Finite Difference Time Domain (FDTD) Modeling of Ground Penetrating Radar for a Heterogeneous Environment

    NASA Astrophysics Data System (ADS)

    Eyuboglu, S.; Daniels, J. J.; Lee, R.; Yeh, J. T.

    2006-12-01

    Ground Penetrating Radar (GPR) is a non-invasive tool commonly used to characterize the physical properties of the subsurface. The translation of the physical measurements of geologic and hydrogeologic conditions is the culmination of many geophysical investigations. When numerical modeling is applied parallel to GPR data, it allows understanding of the effects of complex electromagnetic phenomena by defining and solving problems, as well as predicting the performance of radar in a complex heterogeneous environment. Finite difference time domain (FDTD) has been widely used for numerical modeling of GPR, but most of the previous algorithms are limited in their ability to model the electrical conductivity and permittivity. In this research, a highly efficient robust algorithm was developed to enhance the effectiveness of the FDTD forward modeling in surroundings characterized by an arbitrary distribution of all electrical properties in three dimensional space. In the first part of this research, two different FDTD codes which include different absorbing boundary conditions, Enquist and Majda absorbing boundary condition (ABC) and perfectly matched layer (PML), were used and compared. In the second part, the modeling algorithm was developed for a heterogeneous half-space medium to facilitate statistical modeling of complex distributions of electrical properties in the subsurface. The results produced by the simulation compared with real GPR results reveal high accuracy using the robust algorithm to optimize three dimensional FDTD forward modeling of GPR responses in heterogeneous surroundings.

  16. Investigation and evaluation of a computer program to minimize three-dimensional flight time tracks

    NASA Technical Reports Server (NTRS)

    Parke, F. I.

    1981-01-01

    The program for the DC 8-D3 flight planning was slightly modified for the three dimensional flight planning for DC 10 aircrafts. Several test runs of the modified program over the North Atlantic and North America were made for verifying the program. While geopotential height and temperature were used in a previous program as meteorological data, the modified program uses wind direction and speed and temperature received from the National Weather Service. A scanning program was written to collect required weather information from the raw data received in a packed decimal format. Two sets of weather data, the 12-hour forecast and 24-hour forecast based on 0000 GMT, are used for dynamic processes in testruns. In order to save computing time only the weather data of the North Atlantic and North America is previously stored in a PCF file and then scanned one by one.

  17. A three-dimensional time-dependent model of the polar wind

    NASA Technical Reports Server (NTRS)

    Schunk, R. W.; Sojka, J. J.

    1989-01-01

    A time-dependent three-dimensional multiion model of the polar wind was developed, which covers the altitude range of from 120 to 9000 km and takes into account supersonic ion outflow, shock formation, and ion energization during plasma expansion events. The model was used to study the temporal response of global polar wind to changing magnetospheric conditions, for the winter solstice and for solar-minimum conditions in the northern polar region. Graphs illustrating temporal changes with changes in T(e), T(i), and T(n) along the dawn, the trough, and the dusk convection trajectories and in the O(+), O, and H densities along the same convection trajectories are presented together with conntours of the H(+) and the O(+) densities along the three convection trajectories.

  18. Three-dimensional time-resolved optical mammography of the uncompressed breast

    SciTech Connect

    Enfield, Louise C.; Gibson, Adam P.; Everdell, Nicholas L.; Delpy, David T.; Schweiger, Martin; Arridge, Simon R.; Richardson, Caroline; Keshtgar, Mohammad; Douek, Michael; Hebden, Jeremy C

    2007-06-10

    Optical tomography is being developed as a means of detecting and specifying disease in the adult female breast. We present a series of clinical three-dimensional optical images obtained with a 32-channel time-resolvedsystem and a liquid-coupled interface. Patients place their breasts in a hemispherical cup to whichsources and detectors are coupled, and the remaining space is filled with a highly scattering fluid. Acohort of 38 patients has been scanned, with a variety of benign and malignant lesions. Images show that hypervascularization associated with tumors provides very high contrast due to increased absorption by hemoglobin. Only half of the fibroadenomas scanned could be observed, but of those that could bedetected, all but one revealed an apparent increase in blood volume and a decrease in scatter and oxygen saturation.

  19. Three-dimensional and time-dependent simulation of a planar solid oxide fuel cell stack

    NASA Astrophysics Data System (ADS)

    Achenbach, E.

    1994-04-01

    The mathematical simulation of a planar solid oxide fuel cell (SOFC) is presented. The model accounts for three-dimensional and time-dependent effects. Internal methane-steam reforming and recycling of the anode gas are also considered. The effects of different flow manifolding, i.e., cross-, co-, or counter-flow are discussed. After a short description of the mathematical procedure, computational results are presented. In particular the distribution of the gases, of the current density and of the solid structure temperature across the cell are shown. Furthermore the effects of different flow manifolding, of radiation from the outer stack surface to the surroundings and of anode gas recycling on the operating conditions of the stack are considered. The response of the cell voltage to a load change is also discussed.

  20. Encrypted Three-dimensional Dynamic Imaging using Snapshot Time-of-flight Compressed Ultrafast Photography.

    PubMed

    Liang, Jinyang; Gao, Liang; Hai, Pengfei; Li, Chiye; Wang, Lihong V

    2015-01-01

    Compressed ultrafast photography (CUP), a computational imaging technique, is synchronized with short-pulsed laser illumination to enable dynamic three-dimensional (3D) imaging. By leveraging the time-of-flight (ToF) information of pulsed light backscattered by the object, ToF-CUP can reconstruct a volumetric image from a single camera snapshot. In addition, the approach unites the encryption of depth data with the compressed acquisition of 3D data in a single snapshot measurement, thereby allowing efficient and secure data storage and transmission. We demonstrated high-speed 3D videography of moving objects at up to 75 volumes per second. The ToF-CUP camera was applied to track the 3D position of a live comet goldfish. We have also imaged a moving object obscured by a scattering medium. PMID:26503834

  1. Time-resolved mirage method: A three-dimensional theory and experiments

    NASA Astrophysics Data System (ADS)

    Astrath, N. G. C.; Malacarne, L. C.; Bernabe, H. S.; Baesso, M. L.; Jacinto, C.

    2012-05-01

    A general time-resolved three-dimensional theory of the photothermal beam deflection for the measurement of thermal properties of opaque materials is presented. We derive the analytical solutions for the laser induced temperature profiles in the sample and in the fluid above the sample assuming flux discontinuity at the interface sample/fluid. We compare the analytical solutions with all numerical modeling using finite element analysis. The photothermal deflection signal is calculated and an expression is provided for the transverse photothermal signal at a position-sensing detector. We use the model and the experimental method to investigate opaque plastic and metals, and the results for the thermal properties of the samples are in an excellent agreement in the literature values.

  2. A three-dimensional, time-dependent model of Mobile Bay

    NASA Technical Reports Server (NTRS)

    Pitts, F. H.; Farmer, R. C.

    1976-01-01

    A three-dimensional, time-variant mathematical model for momentum and mass transport in estuaries was developed and its solution implemented on a digital computer. The mathematical model is based on state and conservation equations applied to turbulent flow of a two-component, incompressible fluid having a free surface. Thus, bouyancy effects caused by density differences between the fresh and salt water, inertia from thare river and tidal currents, and differences in hydrostatic head are taken into account. The conservation equations, which are partial differential equations, are solved numerically by an explicit, one-step finite difference scheme and the solutions displayed numerically and graphically. To test the validity of the model, a specific estuary for which scaled model and experimental field data are available, Mobile Bay, was simulated. Comparisons of velocity, salinity and water level data show that the model is valid and a viable means of simulating the hydrodynamics and mass transport in non-idealized estuaries.

  3. Encrypted Three-dimensional Dynamic Imaging using Snapshot Time-of-flight Compressed Ultrafast Photography

    NASA Astrophysics Data System (ADS)

    Liang, Jinyang; Gao, Liang; Hai, Pengfei; Li, Chiye; Wang, Lihong V.

    2015-10-01

    Compressed ultrafast photography (CUP), a computational imaging technique, is synchronized with short-pulsed laser illumination to enable dynamic three-dimensional (3D) imaging. By leveraging the time-of-flight (ToF) information of pulsed light backscattered by the object, ToF-CUP can reconstruct a volumetric image from a single camera snapshot. In addition, the approach unites the encryption of depth data with the compressed acquisition of 3D data in a single snapshot measurement, thereby allowing efficient and secure data storage and transmission. We demonstrated high-speed 3D videography of moving objects at up to 75 volumes per second. The ToF-CUP camera was applied to track the 3D position of a live comet goldfish. We have also imaged a moving object obscured by a scattering medium.

  4. Resonance phenomena in a time-dependent, three-dimensional model of an idealized eddy.

    PubMed

    Rypina, I I; Pratt, L J; Wang, P; Özgökmen, T M; Mezic, I

    2015-08-01

    We analyze the geometry of Lagrangian motion and material barriers in a time-dependent, three-dimensional, Ekman-driven, rotating cylinder flow, which serves as an idealization for an isolated oceanic eddy and other overturning cells with cylindrical geometry in the ocean and atmosphere. The flow is forced at the top through an oscillating upper lid, and the response depends on the frequency and amplitude of lid oscillations. In particular, the Lagrangian geometry changes near the resonant tori of the unforced flow, whose frequencies are rationally related to the forcing frequencies. Multi-scale analytical expansions are used to simplify the flow in the vicinity of resonant trajectories and to investigate the resonant flow geometries. The resonance condition and scaling can be motivated by simple physical argument. The theoretically predicted flow geometries near resonant trajectories have then been confirmed through numerical simulations in a phenomenological model and in a full solution of the Navier-Stokes equations. PMID:26328572

  5. Three-Dimensional Navier-Stokes Calculations Using the Modified Space-Time CESE Method

    NASA Technical Reports Server (NTRS)

    Chang, Chau-lyan

    2007-01-01

    The space-time conservation element solution element (CESE) method is modified to address the robustness issues of high-aspect-ratio, viscous, near-wall meshes. In this new approach, the dependent variable gradients are evaluated using element edges and the corresponding neighboring solution elements while keeping the original flux integration procedure intact. As such, the excellent flux conservation property is retained and the new edge-based gradients evaluation significantly improves the robustness for high-aspect ratio meshes frequently encountered in three-dimensional, Navier-Stokes calculations. The order of accuracy of the proposed method is demonstrated for oblique acoustic wave propagation, shock-wave interaction, and hypersonic flows over a blunt body. The confirmed second-order convergence along with the enhanced robustness in handling hypersonic blunt body flow calculations makes the proposed approach a very competitive CFD framework for 3D Navier-Stokes simulations.

  6. Encrypted Three-dimensional Dynamic Imaging using Snapshot Time-of-flight Compressed Ultrafast Photography

    PubMed Central

    Liang, Jinyang; Gao, Liang; Hai, Pengfei; Li, Chiye; Wang, Lihong V.

    2015-01-01

    Compressed ultrafast photography (CUP), a computational imaging technique, is synchronized with short-pulsed laser illumination to enable dynamic three-dimensional (3D) imaging. By leveraging the time-of-flight (ToF) information of pulsed light backscattered by the object, ToF-CUP can reconstruct a volumetric image from a single camera snapshot. In addition, the approach unites the encryption of depth data with the compressed acquisition of 3D data in a single snapshot measurement, thereby allowing efficient and secure data storage and transmission. We demonstrated high-speed 3D videography of moving objects at up to 75 volumes per second. The ToF-CUP camera was applied to track the 3D position of a live comet goldfish. We have also imaged a moving object obscured by a scattering medium. PMID:26503834

  7. Early lens development in the zebrafish: a three-dimensional time-lapse analysis.

    PubMed

    Greiling, Teri M S; Clark, John I

    2009-09-01

    In vivo, high-resolution, time-lapse imaging characterized lens development in the zebrafish from 16 to 96 hr postfertilization (hpf). In zebrafish, the lens placode appeared in the head ectoderm, similar to mammals. Delamination of the surface ectoderm resulted in the formation of the lens mass, which progressed to a solid sphere of cells separating from the developing cornea at approximately 24 hpf. A lens vesicle was not observed and apoptosis was not a major factor in separation of the lens from the future cornea. Differentiation of primary fibers began in the lens mass followed by formation of the anterior epithelium after delamination was complete. Secondary fibers differentiated from elongating epithelial cells near the posterior pole. Quantification characterized three stages of lens growth. The study confirmed the advantages of live-cell imaging for three-dimensional quantitative structural characterization of the mechanism(s) responsible for cell differentiation in formation of a transparent, symmetric, and refractile lens. PMID:19504455

  8. Interferograms, schlieren, and shadowgraphs constructed from real- and ideal-gas, two- and three-dimensional computed flowfields

    NASA Technical Reports Server (NTRS)

    Yates, Leslie A.

    1993-01-01

    The construction of interferograms, schlieren, and shadowgraphs from computed flowfield solutions permits one-to-one comparisons of computed and experimental results. A method of constructing these images from both ideal- and real-gas, two and three-dimensional computed flowfields is described. The computational grids can be structured or unstructured, and multiple grids are an option. Constructed images are shown for several types of computed flows including nozzle, wake, and reacting flows; comparisons to experimental images are also shown. In addition, th sensitivity of these images to errors in the flowfield solution is demonstrated, and the constructed images can be used to identify problem areas in the computations.

  9. Interferograms, Schlieren, and Shadowgraphs Constructed from Real- and Ideal-Gas, Two- and Three-Dimensional Computed Flowfields

    NASA Technical Reports Server (NTRS)

    Yates, Leslie A.

    1992-01-01

    The construction of interferograms, schlieren, and shadowgraphs from computed flowfield solutions permits one-to-one comparisons of computed and experimental results. A method for constructing these images from both ideal- and real-gas, two- and three-dimensional computed flowfields is described. The computational grids can be structured or unstructured, and multiple grids are an option. Constructed images are shown for several types of computed flows including nozzle, wake, and reacting flows; comparisons to experimental images are also shown. In addition, the sensitivity of these images to errors in the flowfield solution is demonstrated, and the constructed images can be used to identify problem areas in the computations.

  10. Analysis and numerical simulation of a real cell merger using a three-dimensional cloud resolving model

    NASA Astrophysics Data System (ADS)

    Karacostas, T.; Spiridonov, V.; Bampzelis, D.; Pytharoulis, I.; Tegoulias, I.; Tymbanidis, K.

    2016-03-01

    A three-dimensional cloud resolving model is used to study a real cell merger case that occurred on 10 August, 2008 over north-central Greece, causing heavy rainfall, hailfall and high-frequency lightning. Firstly, the storm is observed, analyzed and recorded using a C-band weather radar. Secondly, three distinct simulations are performed using a cloud resolving model. An unseeded simulation, in order to test the ability of the model to reproduce the structural and evolutionary properties of the storm and two seeded simulations in which seeding occurred before and after cell merging. Reflectivity fields are analyzed, horizontally and vertically, at different simulation times. The 3-D numerical simulations suggest that the merger process occurred by two or three isolated single-cells and formed during their SW-NE motion. The merging process apparently alters dynamical and microphysical properties through low and middle level forcing; increases cloud diameters and cloud depths, producing more graupel and ice particles and increases radar reflectivity values. Processed radar images depict a similar view of the storm structure, evolution and interactions of such merging processes. The model calculated maximum radar reflectivity values coincide with the recorded ones. Results indicate that seeding the cloud before its merging produces more positive effects on hail suppression than seeding after merging. These findings are quite important, in order to document the value of the cloud resolving model and its capability to simulate and reproduce the realistic storm processes and to provide a better understanding of the cloud dynamical and microphysical features related to different seeding approaches.

  11. Developmental critical windows and sensitive periods as three-dimensional constructs in time and space.

    PubMed

    Burggren, Warren W; Mueller, Casey A

    2015-01-01

    A critical window (sensitive period) represents a period during development when an organism's phenotype is responsive to intrinsic or extrinsic (environmental) factors. Such windows represent a form of developmental phenotypic plasticity and result from the interaction between genotype and environment. Critical windows have typically been defined as comprising discrete periods in development with a distinct starting time and end time, as identified by experiments following an on and an off protocol. Yet in reality, periods of responsiveness during development are likely more ambiguous that depicted. Our goal is to extend the concept of the developmental critical window by introducing a three-dimensional construct in which time during development, dose of the stressor applied, and the resultant phenotypic modification can be utilized to more realistically define a critical window. Using the example of survival of the brine shrimp (Artemia franciscana) during exposure to different salinity levels during development, we illustrate that it is not just stressor dose or exposure time but the interaction of these two factors that results in the measured phenotypic change, which itself may vary within a critical window. We additionally discuss a systems approach to critical windows, in which the components of a developing system--whether they be molecular, physiological, or morphological--may show differing responses with respect to time and dose. Thus, the plasticity of each component may contribute to a broader overall system response. PMID:25730265

  12. Convergence of Time Averages of Weak Solutions of the Three-Dimensional Navier-Stokes Equations

    NASA Astrophysics Data System (ADS)

    Foias, Ciprian; Rosa, Ricardo M. S.; Temam, Roger M.

    2015-08-01

    Using the concept of stationary statistical solution, which generalizes the notion of invariant measure, it is proved that, in a suitable sense, time averages of almost every Leray-Hopf weak solution of the three-dimensional incompressible Navier-Stokes equations converge as the averaging time goes to infinity. This system of equations is not known to be globally well-posed, and the above result answers a long-standing problem, extending to this system a classical result from ergodic theory. It is also shown that, from a measure-theoretic point of view, the stationary statistical solution obtained from a generalized limit of time averages is independent of the choice of the generalized limit. Finally, any Borel subset of the phase space with positive measure with respect to a stationary statistical solution is such that for almost all initial conditions in that Borel set and for at least one Leray-Hopf weak solution starting with that initial condition, the corresponding orbit is recurrent to that Borel subset and its mean sojourn time within that Borel subset is strictly positive.

  13. A three-dimensional robust nonlinear terminal guidance law with ISS finite-time convergence

    NASA Astrophysics Data System (ADS)

    Li, Guilin; Ji, Haibo

    2016-05-01

    This paper presents a novel three-dimensional nonlinear terminal guidance law with finite-time convergence for intercepting manoeuvring targets. Different from the usual method of decoupling the missile-target relative motion into two-dimensional planes, this law is designed via using the coupled dynamics. The guidance law is derived based on the theory of finite-time input-to-state stability (ISS), which needs no assumption of the linearisation and the estimation of target accelerations. Under this law, the line-of-sight angular rates can be stabilised to a small domain of convergence around zero in finite time. The convergence rate and convergence domain can be adjusted by changing the guidance parameters. First, a sufficient condition on finite-time ISS of the guidance system is given, and is subsequently used to design the guidance law. Finally, simulation results are provided to show that the proposed guidance law possesses fast convergence rate and strong robustness to target manoeuvres.

  14. Three-dimensional diffuse optical tomography with full multi-view time-domain data

    NASA Astrophysics Data System (ADS)

    Bouza Domınguez, Jorge; Bérubé-Lauzière, Yves

    2013-03-01

    In this work, synthetic time-domain data are generated as if it were collected with a state-of-the-art multi-view experimental optical scanner developed in our group for small animal imaging, and used in a tomographic image reconstruction algorithm. The collected data comprises full time-dependent optical signals leaving the biological medium and acquired all around the medium. The diffuse optical tomography (DOT) algorithm relies on the time dependent parabolic simplified spherical harmonics (TD-pSPN) equations as the forward model to recover the 3D absorption and diffusion coefficient maps of the medium. The inverse problem is casted and solved as an iterative constrained optimization problem where an objective function determines the accuracy of the forward model predictions at each iteration. Time-dependent adjoint variables are introduced to accelerate the calculation of the gradient of the objective function. A three-dimensional case involving an absorption heterogeneity in a homogeneous medium is presented, reproducing practical situations encountered in our lab. The results support our hypothesis that accurate quantitative 3D maps of optical properties of biological tissues can be retrieved using intrinsic measurements obtained with our experimental scanner along with our DOT algorithm.

  15. Gender Differences in Object Location Memory in a Real Three-Dimensional Environment

    ERIC Educational Resources Information Center

    Iachini, Tina; Sergi, Ida; Ruggiero, Gennaro; Gnisci, Augusto

    2005-01-01

    In this preliminary study we investigate gender differences in object location memory. Our purpose is to extend the results about object location memory obtained in laboratory settings to a real 3-D environment and to further distinguish the specific components involved in this kind of memory by considering the strategies adopted to perform the…

  16. Volume moiré tomography based on double cross gratings for real three-dimensional flow field diagnosis.

    PubMed

    Sun, Nan; Song, Yang; Wang, Jia; Li, Zhen-Hua; He, An-Zhi

    2012-12-01

    Since the advantages of noncontact, strong antidisturbing capability and wide measurement range, moiré tomography has been considered a powerful diagnostic tool for flow fields. In this paper, the volume computerized tomography is introduced to obtain the real three-dimensional reconstruction based on moiré deflectometry. In order to realize volume moiré tomography (VMT), double cross gratings are applied in the moiré deflected system to gain the shearing phase distribution of the moiré deflected projection in two mutually perpendicular directions simultaneously. Thus, the scalar diffraction theory is used for analyzing the imaging process of VMT based on double cross gratings to achieve the explicit form of shearing phase. Finally, the real temperature distribution of a propane flame is reconstructed, which can confirm the VMT method. PMID:23207377

  17. Correlated electron dynamics with time-dependent quantum Monte Carlo: three-dimensional helium.

    PubMed

    Christov, Ivan P

    2011-07-28

    Here the recently proposed time-dependent quantum Monte Carlo method is applied to three dimensional para- and ortho-helium atoms subjected to an external electromagnetic field with amplitude sufficient to cause significant ionization. By solving concurrently sets of up to 20,000 coupled 3D time-dependent Schrödinger equations for the guide waves and corresponding sets of first order equations of motion for the Monte Carlo walkers we obtain ground state energies in close agreement with the exact values. The combined use of spherical coordinates and B-splines along the radial coordinate proves to be especially accurate and efficient for such calculations. Our results for the dipole response and the ionization of an atom with un-correlated electrons are in good agreement with the predictions of the conventional time-dependent Hartree-Fock method while the calculations with correlated electrons show enhanced ionization that is due to the electron-electron repulsion. PMID:21806103

  18. Holocinematographic velocimeter for measuring time-dependent, three-dimensional flows

    NASA Astrophysics Data System (ADS)

    Beeler, George B.; Weinstein, Leonard M.

    1987-06-01

    Two simulatneous, orthogonal-axis holographic movies are made of tracer particles in a low-speed water tunnel to determine the time-dependent, three-dimensional velocity field. This instrument is called a Holocinematographic Velocimeter (HCV). The holographic movies are reduced to the velocity field with an automatic data reduction system. This permits the reduction of large numbers of holograms (time steps) in a reasonable amount of time. The current version of the HCV, built for proof-of-concept tests, uses low-frame rate holographic cameras and a prototype of a new type of water tunnel. This water tunnel is a unique low-disturbance facility which has minimal wall effects on the flow. This paper presents the first flow field examined by the HCV, the two-dimensional von Karman vortex street downstream of an unswept circular cylinder. Key factors in the HCV are flow speed, spatial and temporal resolution required, measurement volume, film transport speed, and laser pulse length. The interactions between these factors are discussed.

  19. Holocinematographic velocimeter for measuring time-dependent, three-dimensional flows

    NASA Technical Reports Server (NTRS)

    Beeler, George B.; Weinstein, Leonard M.

    1987-01-01

    Two simulatneous, orthogonal-axis holographic movies are made of tracer particles in a low-speed water tunnel to determine the time-dependent, three-dimensional velocity field. This instrument is called a Holocinematographic Velocimeter (HCV). The holographic movies are reduced to the velocity field with an automatic data reduction system. This permits the reduction of large numbers of holograms (time steps) in a reasonable amount of time. The current version of the HCV, built for proof-of-concept tests, uses low-frame rate holographic cameras and a prototype of a new type of water tunnel. This water tunnel is a unique low-disturbance facility which has minimal wall effects on the flow. This paper presents the first flow field examined by the HCV, the two-dimensional von Karman vortex street downstream of an unswept circular cylinder. Key factors in the HCV are flow speed, spatial and temporal resolution required, measurement volume, film transport speed, and laser pulse length. The interactions between these factors are discussed.

  20. Time resolved three-dimensional flamebase imaging of a lifted jet flame by laser scanning

    NASA Astrophysics Data System (ADS)

    Weinkauff, J.; Greifenstein, M.; Dreizler, A.; Böhm, B.

    2015-10-01

    The measurement of flame surface evolution in both space and time is necessary for the advancement of knowledge concerning the physical processes contributing to lifted jet flame stabilisation. Previous studies either reproduce the flame front accurately in three-dimensional space or in time. In this study a measurement system capable of both is presented. Based on the Mie-scattering of oil droplets added to the jet flow, the system reconstructs the volumetric surface at the base of a lifted jet flame from a series of two-dimensional slices. The slices are created using a pulsed high-speed laser and a polygonal laser scanner unit which serves to sweep the laser beam through the measurement volume. A single high-speed camera is used for recording the subsequent measurement slices. The achieved temporal and spatial resolution as well as the accuracy and precision of the sheet placement are discussed in respect to the flames’ scales. The first results of the reconstruction of the lifted jet flame at its stabilisation point show the potential of such measurements to avoid the ambiguities in interpreting conventional 2D-data.

  1. Spherical balloon response to three-dimensional time-dependent flows

    NASA Technical Reports Server (NTRS)

    Fichtl, G. H.

    1972-01-01

    The concept of the Lagrangian displacement of a balloon is introduced. It is shown that the general balloon response problem is extremely complicated because the wind-forcing functions in the balloon equations of motion are functions of the wind velocity vector and its Eulerian first derivatives evaluated at the location of the balloon. The linear perturbation equations for a spherical balloon are derived by perturbing the components of velocity of the balloon about a terminal velocity state which is in equilibrium with a space-time invariant mean horizontal flow. The atmospheric flow is also perturbed such that the resulting equations can be used to analyze the responses of spherical balloons to three-dimensional time-dependent flows. The wind field is represented in terms of a four-fold Fourier integral that involves three orthogonal wave numbers and a frequency, while the balloon components of velocity are represented as Fourier integrals involving a frequency which, in turn, is a function of the wind field wave numbers and frequency and the unperturbed flow components of velocity.

  2. Polarization dynamics and polarization time of random three-dimensional electromagnetic fields

    SciTech Connect

    Voipio, Timo; Setaelae, Tero; Shevchenko, Andriy; Friberg, Ari T.

    2010-12-15

    We investigate the polarization dynamics of random, stationary three-dimensional (3D) electromagnetic fields. For analyzing the time evolution of the instantaneous polarization state, two intensity-normalized polarization autocorrelation functions are introduced, one based on a geometric approach with the Poincare vectors and the other on energy considerations with the Jones vectors. Both approaches lead to the same conclusions on the rate and strength of the polarization dynamics and enable the definition of a polarization time over which the state of polarization remains essentially unchanged. For fields obeying Gaussian statistics, the two correlation functions are shown to be expressible in terms of quantities characterizing partial 3D polarization and electromagnetic coherence. The 3D degree of polarization is found to have the same meaning in the 3D polarization dynamics as the usual two-dimensional (2D) degree of polarization does with planar fields. The formalism is demonstrated with several examples, and it is expected to be useful in applications dealing with polarization fluctuations of 3D light.

  3. A time accurate finite volume high resolution scheme for three dimensional Navier-Stokes equations

    NASA Technical Reports Server (NTRS)

    Liou, Meng-Sing; Hsu, Andrew T.

    1989-01-01

    A time accurate, three-dimensional, finite volume, high resolution scheme for solving the compressible full Navier-Stokes equations is presented. The present derivation is based on the upwind split formulas, specifically with the application of Roe's (1981) flux difference splitting. A high-order accurate (up to the third order) upwind interpolation formula for the inviscid terms is derived to account for nonuniform meshes. For the viscous terms, discretizations consistent with the finite volume concept are described. A variant of second-order time accurate method is proposed that utilizes identical procedures in both the predictor and corrector steps. Avoiding the definition of midpoint gives a consistent and easy procedure, in the framework of finite volume discretization, for treating viscous transport terms in the curvilinear coordinates. For the boundary cells, a new treatment is introduced that not only avoids the use of 'ghost cells' and the associated problems, but also satisfies the tangency conditions exactly and allows easy definition of viscous transport terms at the first interface next to the boundary cells. Numerical tests of steady and unsteady high speed flows show that the present scheme gives accurate solutions.

  4. Tomographic imaging of local earthquake delay times for three-dimensional velocity variation in western Washington

    SciTech Connect

    Lees, J.M.; Crosson, R.S. )

    1990-04-10

    Tomographic inversion is applied to delay times from local earthquakes to image three dimensional velocity variations in the Puget Sound region of western Washington. The 37,500 square km region is represented by nearly cubic blocks of 5 km per side. P-wave arrival time observations from 4,387 crustal earthquakes, with depths of 0 to 40 km, were used as sources producing 36,865 rays covering the target region. A conjugate gradient method (LSQR) is used to invert the large, sparse system of equations. To diminish the effects of noisy data, the Laplacian is constrained to be zero within horizontal layers, providing smoothing of the model. The resolution is estimated by calculating impulse responses at blocks of interest and estimates of standard errors are calculated by the jackknife statistical procedure. Results of the inversion are correlated with some known geologic features and independent geophysical measurements. High P-wave velocities along the eastern flank of the Olympic Peninsula are interpreted to reflect the subsurface extension of Crescent terrane. Low velocities beneath the Puget Sound further to the east are inferred to reflect thick sediment accumulations. The Crescent terrane appears to extend beneath Puget Sound, consistent with its interpretation as a major accretionary unit. In the southern Puget Sound basin, high velocity anomalies at depths of 10-20 km are interpreted as Crescent terrane and are correlated with a region of low seismicity. Near Mt. Ranier, high velocity anomalies may reflect buried plutons.

  5. Three-dimensional crustal structure of the Mendocino Triple Junction region from local earthquake travel times

    NASA Astrophysics Data System (ADS)

    Verdonck, David; Zandt, George

    1994-12-01

    The large-scale, three-dimensional geometry of the Mendocino Triple Junction at Cape Mendocino, California, was investigated by inverting nearly 19,000 P wave arrival times from over 1400 local earthquakes to estimate the three-dimensional velocity structure and hypocentral parameters. A velocity grid 175 km (N-S) by 125 km (E-W) centered near Garberville, California, was constructed with 25 km horizontal and 5 km vertical mode spacing. The model was well resolved near Cape Mendocino, where the earthquakes and stations are concentrated. At about 40.6 N latitude a high-velocity gradient between 6.5 and 7.5 km/s dips gently to the south and east from about 15 km depth near the coast. Relocated hypocenters concentrate below this high gradient which we interpret as the oceanic crust of the subducted Gorda Plate. Therefore the depth to the top of the Gorda Plate near Cape Mendocino is interpreted to be approximately 15 km. The Gorda Plate appears intact and dipping approximately 8 deg eastward due to subduction and flexing downward 6 deg - 12 deg to the south. Both hypocenters and velocity structure suggest that the southern edge of the plate intersects the coastline at 40.3 N latitude and maintains a linear trend 15 deg south of east to at least 123 W longitude. The top of a large low-velocity region at 20-30 km depth extends about 50 km N-S and 75 km E-W (roughly between Garberville and Covelo) and is located above and south of the southern edge of the Gorda Plate. We interpret this low velocity area to be locally thickened crust (8-10 km) due to either local compressional forces associated with north-south compression caused by the northward impingement of the rigid Pacific Plate or by underthrusting of the base of the accretionary subduction complex at the southern terminous of the Cascadia Subduction Zone. South of Cape Mendocino and southwest of the Garberville fault, high velocities indicative of oceanic crust are detected at 15 km depth. We interpret this

  6. Three-dimensional crustal structure for the Mendocino Triple Junction region from local earthquake travel times

    SciTech Connect

    Verdonck, D.; Zandt, G.

    1994-12-10

    The large-scale, three-dimensional geometry of the Mendocino Triple Junction at Cape Mendocino, California, was investigated by inverting nearly 19,000 P wave arrival times from over 1400 local earthquakes to estimate the three-dimensional velocity structure and hypocentral parameters. A velocity grid 175 km (N-S) by 125 km (E-W) centered near Garberville, California, was constructed with 25 km horizontal and 5 km vertical node spacing. The model was well resolved near Cape Mendocino, where the earthquakes and stations are concentrated. At about 40.6{degrees}N latitude a high-velocity gradient between 6.5 and 7.5 km/s dips gently to the south and east from about 15 km depth near the coast. Relocated hypocenters concentrate below this high gradient which the authors interpret as the oceanic crust of the subducted Gorda Plate. Therefore the depth to the top of the Gorda Plate near Cape Mendocino is interpreted to be {approximately} 15 km. The Gorda Plate appears intact and dipping {approximately}8{degrees} eastward due to subduction and flexing downward 6{degrees}-12{degrees} to the south. Both hypocenters and velocity structure suggest that the southern edge of the plate intersects the coastline at 40.3{degrees}N latitude and maintains a linear trend 15{degrees} south of east to at least 123{degrees}W longitude. The top of a large low-velocity region at 20-30 km depth extends about 50 km N-S and 75 km E-W (roughly between Garberville and Covelo) and is located above and south of the southern edge of the Gorda Plate. The authors interpret this low velocity area to be locally thickened crust (8-10 km) due to either local compressional forces associated with north-south compression caused by the northward impingement of the rigid Pacific Plate or by underthrusting of the base of the accretionary subduction complex at the southern terminous of the Cascadia Subduction Zone. 66 refs., 11 figs., 3 tabs.

  7. Simulations of time-dependent three-dimensional vortices with application to Neptune's Great Dark Spot

    NASA Astrophysics Data System (ADS)

    Lebeau, Raymond Paul, Jr.

    We use the EPIC atmospheric: model, a primitive-equation, isentropic-coordinate GCM, to simulate time-dependent vortices under conditions similar to those found on Neptune. The vortices have roughly elliptical cross- sections and exhibit motions that resemble the behavior of Neptune's Great Dark Spot (GDS), including equatorward drift, nutating oscillations in aspect ratio and orientation angle, and quasi-periodic tail formation. The simulated vortices also exhibit complex, three- dimensional motions that may explain the occasional appearance of the GDS as two overlapping ellipses. We find that the meridional drift of the vortices is strongly correlated with the meridional gradient of the environmental potential vorticity, β*. This result complements related studies of hurricane motions. The correlation suggests that the drift rate of GDS-type vortices on Neptune, which can be monitored over the long term by the Hubble Space Telescope (HST), is diagnostic of the vorticity gradient on the planet. The best fit to the Voyager GDS drift rate in our simulations corresponds to β*/approx2×10-12/ m-1s- 1. This is about 1/3 of the value given by the zonal- wind profile of Sromovsky et al. (1993), determined by fitting a polynomial in latitude to the cloud-tracking data. We calculate new fit to the same data using Legendre polynomials (spherical harmonics), which yields a significantly lower value for β*, more in line with our vortex-drift results. We show that vortex shape oscillations occur both in cases of zero background potential-vorticity gradient, corresponding to the conditions in analytical Kida-type models of oscillating vortices, and in cases of non-zero background gradient, corresponding to conditions that have not yet been investigated analytically. While the shape oscillations are qualitatively Kida-like, in detail they are distinctly different, suggesting that existing theory may not be sufficient to describe non-uniform, three- dimensional vortices. We

  8. Intracranial aneurysms: Diagnostics accuracy of three-dimensional, fourier transform, time-of-flight MR angiography

    SciTech Connect

    Korogi, Yukunori; Takahashi, Mutsumasa; Mabuchi, Nobuhisa; Miki, Hitoshi; Fujiwara, Satoru; Horikawa, Yoshiharu; Nakagawa, Toshio; O`Uchi, Toshihiro; Watabe, Tsuneya; Shiga, Hayao

    1994-10-01

    To assess the accuracy of three-dimensional, Fourier transform, time-of-flight magnetic resonance (MR) angiography in the identification of intracranial aneurysms. MR angiograms of 126 patients (59 male and 67 female patients, aged 12-77 years) with various intracranial vascular lesions were evaluated. Seventy-eight aneurysms, including 60 less than 5 mm in diameter, in 61 patients were depicted at conventional angiography. Eight projection images, as well as one axial collapsed MR angiogram obtained with a maximum-intensity projection algorithm, were used for evaluation. Sensitivity for the five observers ranged from 58% to 68% (mean, 63%). Higher sensitivity was achieved for anterior communicating and middle cerebral artery aneurysms, while that for internal carotid artery aneurysms was poor. Sensitivities for small and medium aneurysms ranged from 50% to 60% (mean, 56%) and from 77% to 94% (mean, 85%), respectively. MR angiography can depict intracranial aneurysms 5 mm or larger with good accuracy but is less useful for the identification of smaller aneurysms. 12 refs., 5 figs., 5 tabs.

  9. Metamorphosis revealed: time-lapse three-dimensional imaging inside a living chrysalis

    PubMed Central

    Lowe, Tristan; Garwood, Russell J.; Simonsen, Thomas J.; Bradley, Robert S.; Withers, Philip J.

    2013-01-01

    Studies of model insects have greatly increased our understanding of animal development. Yet, they are limited in scope to this small pool of model species: a small number of representatives for a hyperdiverse group with highly varied developmental processes. One factor behind this narrow scope is the challenging nature of traditional methods of study, such as histology and dissection, which can preclude quantitative analysis and do not allow the development of a single individual to be followed. Here, we use high-resolution X-ray computed tomography (CT) to overcome these issues, and three-dimensionally image numerous lepidopteran pupae throughout their development. The resulting models are presented in the electronic supplementary material, as are figures and videos, documenting a single individual throughout development. They provide new insight and details of lepidopteran metamorphosis, and allow the measurement of tracheal and gut volume. Furthermore, this study demonstrates early and rapid development of the tracheae, which become visible in scans just 12 h after pupation. This suggests that there is less remodelling of the tracheal system than previously expected, and is methodologically important because the tracheal system is an often-understudied character system in development. In the future, this form of time-lapse CT-scanning could allow faster and more detailed developmental studies on a wider range of taxa than is presently possible. PMID:23676900

  10. Field Line Resonances in Quiet and Disturbed Time Three-dimensional Magnetospheres

    SciTech Connect

    C.Z. Cheng; S. Zaharia

    2002-05-30

    Numerical solutions for field line resonances (FLR) in the magnetosphere are presented for three-dimensional equilibrium magnetic fields represented by two Euler potentials as B = -j Y -a, where j is the poloidal flux and a is a toroidal angle-like variable. The linearized ideal-MHD equations for FLR harmonics of shear Alfvin waves and slow magnetosonic modes are solved for plasmas with the pressure assumed to be isotropic and constant along a field line. The coupling between the shear Alfvin waves and the slow magnetosonic waves is via the combined effects of geodesic magnetic field curvature and plasma pressure. Numerical solutions of the FLR equations are obtained for a quiet time magnetosphere as well as a disturbed time magnetosphere with a thin current sheet in the near-Earth region. The FLR frequency spectra in the equatorial plane as well as in the auroral latitude are presented. The field line length, magnetic field intensity, plasma beta, geodesic curvature and pressure gradient in the poloidal flux surface are important in determining the FLR frequencies. In general, the computed shear Alfvin FLR frequency based on the full MHD model is larger than that based on the commonly adopted cold plasma model in the beq > 1 region. For the quiet time magnetosphere, the shear Alfvin resonance frequency decreases monotonically with the equatorial field line distance, which reasonably explains the harmonically structured continuous spectrum of the azimuthal magnetic field oscillations as a function of L shell in the L is less than or equal to 9RE region. However, the FLR frequency spectrum for the disturbed time magnetosphere with a near-Earth thin current sheet is substantially different from that for the quiet time magnetosphere for R > 6RE, mainly due to shorter field line length due to magnetic field compression by solar wind, reduced magnetic field intensity in the high-beta current sheet region, azimuthal pressure gradient, and geodesic magnetic field

  11. [Optimization of Three-dimensional Ultrashort Echo Time Magnetic Resonance Imaging at a Low Field].

    PubMed

    Huang, Yuli; Du, Yiping

    2015-12-01

    Conventional magnetic resonance (MR) pulse sequences typically have an echo time (TE) of 1 ms or longer, providing an excellent contrast between different soft tissues. However, some short T2 tissues appear dark in conventional MR images because the signal from these tissues has decayed to nearly zero before the center of k-space is acquired. Because of the ability of directly imaging short T2 tissues, ultrashort echo time technique has been widely studied in recent years. An overwhelming majority of the studies were carried out at high fields, while many low- field scanner systems are still used in developing countries. To investigate the effects of the delay between analog-to-digital converter sampling and the readout gradient, the TE of the second echo used to calculate the R2 * map, and the undersampling ratio on the results of three-dimensional (3D) ultrashort echo time imaging at a low field, we implemented a 3D ultrashort echo time sequence on a 0. 35T scanner. Different parameters were used and the reconstructed images and R2 * maps were compared. Images reconstructed with slightly varying delays appeared quite different. Different contrast between short and long T2 tissues were found in R2 * maps calculated with different echoes. The result of undersampling study indicated that excessive undersampling could cause unwanted blurring, making it difficult to better visualize the short T2 tissues in the R2 * map. The results suggested that cautions should be taken in the choice of these parameters in 3D ultrashort echo time imaging. Short T2 tissues can be visualized with appropriate imaging parameters at this low field. PMID:27079094

  12. Extracting Surface Activation Time from the Optically Recorded Action Potential in Three-Dimensional Myocardium

    PubMed Central

    Walton, Richard D.; Smith, Rebecca M.; Mitrea, Bogdan G.; White, Edward; Bernus, Olivier; Pertsov, Arkady M.

    2012-01-01

    Optical mapping has become an indispensible tool for studying cardiac electrical activity. However, due to the three-dimensional nature of the optical signal, the optical upstroke is significantly longer than the electrical upstroke. This raises the issue of how to accurately determine the activation time on the epicardial surface. The purpose of this study was to establish a link between the optical upstroke and exact surface activation time using computer simulations, with subsequent validation by a combination of microelectrode recordings and optical mapping experiments. To simulate wave propagation and associated optical signals, we used a hybrid electro-optical model. We found that the time of the surface electrical activation (tE) within the accuracy of our simulations coincided with the maximal slope of the optical upstroke (tF∗) for a broad range of optical attenuation lengths. This was not the case when the activation time was determined at 50% amplitude (tF50) of the optical upstroke. The validation experiments were conducted in isolated Langendorff-perfused rat hearts and coronary-perfused pig left ventricles stained with either di-4-ANEPPS or the near-infrared dye di-4-ANBDQBS. We found that tF∗ was a more accurate measure of tE than was tF50 in all experimental settings tested (P = 0.0002). Using tF∗ instead of tF50 produced the most significant improvement in measurements of the conduction anisotropy and the transmural conduction time in pig ventricles. PMID:22225795

  13. Lagrangian and Eulerian analysis of transport and mixing in the three dimensional, time dependent Hill's spherical vortex

    NASA Astrophysics Data System (ADS)

    McIlhany, Kevin L.; Guth, Stephen; Wiggins, Stephen

    2015-06-01

    In this paper, we extend the notion of Eulerian indicators (EIs), previously developed for two dimensional time dependent flows, to three dimensional time dependent flows, where the time dependence can be arbitrary. These are applied to a study of transport and mixing in the Hill's spherical vortex subject to a linear strain rate field. We consider the axisymmetric case and the fully three dimensional case with different types of time dependence. We develop a Lagrangian characterization of transport and mixing appropriate for open three dimensional flows and we show that the EIs provide a detailed description of the flow structure that can be correlated with the Lagrangian transport and mixing results. The EIs yield results consistent with the dynamics of the Hill's vortex flow characteristics, correlation with transverse shear, and anti-correlation with transversality.

  14. A California statewide three-dimensional seismic velocity model from both absolute and differential times

    USGS Publications Warehouse

    Lin, G.; Thurber, C.H.; Zhang, H.; Hauksson, E.; Shearer, P.M.; Waldhauser, F.; Brocher, T.M.; Hardebeck, J.

    2010-01-01

    We obtain a seismic velocity model of the California crust and uppermost mantle using a regional-scale double-difference tomography algorithm. We begin by using absolute arrival-time picks to solve for a coarse three-dimensional (3D) P velocity (VP) model with a uniform 30 km horizontal node spacing, which we then use as the starting model for a finer-scale inversion using double-difference tomography applied to absolute and differential pick times. For computational reasons, we split the state into 5 subregions with a grid spacing of 10 to 20 km and assemble our final statewide VP model by stitching together these local models. We also solve for a statewide S-wave model using S picks from both the Southern California Seismic Network and USArray, assuming a starting model based on the VP results and a VP=VS ratio of 1.732. Our new model has improved areal coverage compared with previous models, extending 570 km in the SW-NE directionand 1320 km in the NW-SE direction. It also extends to greater depth due to the inclusion of substantial data at large epicentral distances. Our VP model generally agrees with previous separate regional models for northern and southern California, but we also observe some new features, such as high-velocity anomalies at shallow depths in the Klamath Mountains and Mount Shasta area, somewhat slow velocities in the northern Coast Ranges, and slow anomalies beneath the Sierra Nevada at midcrustal and greater depths. This model can be applied to a variety of regional-scale studies in California, such as developing a unified statewide earthquake location catalog and performing regional waveform modeling.

  15. Three-dimensional time optimal double angular momentum reversal trajectory using solar sails

    NASA Astrophysics Data System (ADS)

    Zeng, Xiangyuan; Baoyin, Hexi; Li, Junfeng; Gong, Shengping

    2011-12-01

    A new concept of three dimensional non-Keplerian trajectories with double angular momentum reversal is investigated with high performance solar sails. The main discussion of this paper is about such 3D solar inverse orbits with inner constraints. The problem is addressed in a time optimal control framework solved by an indirect method. Two typical solar inverse orbits have been achieved and presented in a 3D non-dimensional dynamic model in the Heliocentric Inertial Frame. Starting from the Earth orbit ecliptic plane, a sailcraft in the inverse orbit exhibits a butterfly shape trajectory. As such, the new orbits are symmetrical with respect to a plane which contains the Sun-perihelion line. The relation of the sail attitude angles between the two symmetrical parts of the orbits are used to reduce the simulation effort. The quasi-heliostationary property at its aphelia is demonstrated with variation of the orbital radius. Evolutions of the orbital velocity and optimal sail orientations are also outlined and discussed to benefit future design work. As is suited for space observation guaranteed by its butterfly shape, the inverse orbits are thoroughly studied in terms of the concerned parameters. The discussion of the parametric influence is ranked in order as perihelion distance r E , required maximum position z max, perihelion position z f and the sail lightness number β. Suitable ranges of each parameter are adopted to illustrate the orbital variation trend. Through numerical simulations the features of such inverse orbits are further emphasized to provide an initial reference for future researchers.

  16. TEMPEST: A three-dimensional time-dependent computer program for hydrothermal analysis: Volume 1, Numerical methods and input instructions

    SciTech Connect

    Trent, D.S.; Eyler, L.L.; Budden, M.J.

    1983-09-01

    This document describes the numerical methods, current capabilities, and the use of the TEMPEST (Version L, MOD 2) computer program. TEMPEST is a transient, three-dimensional, hydrothermal computer program that is designed to analyze a broad range of coupled fluid dynamic and heat transfer systems of particular interest to the Fast Breeder Reactor thermal-hydraulic design community. The full three-dimensional, time-dependent equations of motion, continuity, and heat transport are solved for either laminar or turbulent fluid flow, including heat diffusion and generation in both solid and liquid materials. 10 refs., 22 figs., 2 tabs.

  17. Investigation of storm time magnetotail and ion injection using three-dimensional global hybrid simulation

    NASA Astrophysics Data System (ADS)

    Lin, Y.; Wang, X. Y.; Lu, S.; Perez, J. D.; Lu, Q.

    2014-09-01

    Dynamics of the near-Earth magnetotail associated with substorms during a period of extended southward interplanetary magnetic field is studied using a three-dimensional (3-D) global hybrid simulation model that includes both the dayside and nightside magnetosphere, for the first time, with physics from the ion kinetic to the global Alfvénic convection scales. It is found that the dayside reconnection leads to the penetration of the dawn-dusk electric field through the magnetopause and thus a thinning of the plasma sheet, followed by the magnetotail reconnection with 3-D, multiple flux ropes. Ion kinetic physics is found to play important roles in the magnetotail dynamics, which leads to the following results: (1) Hall electric fields in the thin current layer cause a systematic dawnward ion drift motion and thus a dawn-dusk asymmetry of the plasma sheet with a higher (lower) density on the dawnside (duskside). Correspondingly, more reconnection occurs on the duskside. Bidirectional fast ions are generated due to acceleration in reconnection, and more high-speed earthward flow injections are found on the duskside than the dawnside. Such finding of the dawn-dusk asymmetry is consistent with recent satellite observations. (2) The injected ions undergo the magnetic gradient and curvature drift in the dipole-like field, forming a ring current. (3) Ion particle distributions reveal multiple populations/beams at various distances in the tail. (4) Dipolarization of the tail magnetic field takes place due to the pileup of the injected magnetic fluxes and thermal pressure of injected ions, where the fast earthward flow is stopped. Oscillation of the dipolarization front is developed at the fast-flow braking, predominantly on the dawnside. (5) Kinetic compressional wave turbulence is present around the dipolarization front. The cross-tail currents break into small-scale structures with k⟂ρi˜1, where k⟂ is the perpendicular wave number. A sharp dip of magnetic field

  18. Image system for three dimensional, 360{degree}, time sequence surface mapping of moving objects

    DOEpatents

    Lu, S.Y.

    1998-12-22

    A three-dimensional motion camera system comprises a light projector placed between two synchronous video cameras all focused on an object-of-interest. The light projector shines a sharp pattern of vertical lines (Ronchi ruling) on the object-of-interest that appear to be bent differently to each camera by virtue of the surface shape of the object-of-interest and the relative geometry of the cameras, light projector and object-of-interest. Each video frame is captured in a computer memory and analyzed. Since the relative geometry is known and the system pre-calibrated, the unknown three-dimensional shape of the object-of-interest can be solved for by matching the intersections of the projected light lines with orthogonal epipolar lines corresponding to horizontal rows in the video camera frames. A surface reconstruction is made and displayed on a monitor screen. For 360{degree} all around coverage of the object-of-interest, two additional sets of light projectors and corresponding cameras are distributed about 120{degree} apart from one another. 20 figs.

  19. Image system for three dimensional, 360 DEGREE, time sequence surface mapping of moving objects

    DOEpatents

    Lu, Shin-Yee

    1998-01-01

    A three-dimensional motion camera system comprises a light projector placed between two synchronous video cameras all focused on an object-of-interest. The light projector shines a sharp pattern of vertical lines (Ronchi ruling) on the object-of-interest that appear to be bent differently to each camera by virtue of the surface shape of the object-of-interest and the relative geometry of the cameras, light projector and object-of-interest Each video frame is captured in a computer memory and analyzed. Since the relative geometry is known and the system pre-calibrated, the unknown three-dimensional shape of the object-of-interest can be solved for by matching the intersections of the projected light lines with orthogonal epipolar lines corresponding to horizontal rows in the video camera frames. A surface reconstruction is made and displayed on a monitor screen. For 360.degree. all around coverage of theobject-of-interest, two additional sets of light projectors and corresponding cameras are distributed about 120.degree. apart from one another.

  20. Three dimensional time lapse imaging of live cell mitochondria with photothermal optical lock-in optical coherence microscopy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Sison, Miguel; Chakrabortty, Sabyasachi; Extermann, Jerome; Nahas, Amir; Pache, Christophe; Weil, Tanja; Lasser, Theo

    2016-03-01

    The photothermal optical lock-in optical coherence microscope (poli-OCM) introduced molecular specificity to OCM imaging, which is conventionally, a label-free technique. Here we achieve three-dimensional live cell and mitochondria specific imaging using ~4nm protein-functionalized gold nanoparticles (AuNPs). These nanoparticles do not photobleach and we demonstrate they're suitability for long-term time lapse imaging. We compare the accuracy of labelling with these AuNPs using classical fluorescence confocal imaging with a standard mitochondria specific marker. Furthermore, time lapse poli-OCM imaging every 5 minutes over 1.5 hours period was achieved, revealing the ability for three-dimensional monitoring of mitochondria dynamics.

  1. Three-dimensional time-dependent computer modeling of the electrothermal atomizers for analytical spectrometry

    NASA Astrophysics Data System (ADS)

    Tsivilskiy, I. V.; Nagulin, K. Yu.; Gilmutdinov, A. Kh.

    2016-02-01

    A full three-dimensional nonstationary numerical model of graphite electrothermal atomizers of various types is developed. The model is based on solution of a heat equation within solid walls of the atomizer with a radiative heat transfer and numerical solution of a full set of Navier-Stokes equations with an energy equation for a gas. Governing equations for the behavior of a discrete phase, i.e., atomic particles suspended in a gas (including gas-phase processes of evaporation and condensation), are derived from the formal equations molecular kinetics by numerical solution of the Hertz-Langmuir equation. The following atomizers test the model: a Varian standard heated electrothermal vaporizer (ETV), a Perkin Elmer standard THGA transversely heated graphite tube with integrated platform (THGA), and the original double-stage tube-helix atomizer (DSTHA). The experimental verification of computer calculations is carried out by a method of shadow spectral visualization of the spatial distributions of atomic and molecular vapors in an analytical space of an atomizer.

  2. Quantum dynamics with real wave packets, including application to three-dimensional (J=0)D+H{sub 2}{r_arrow}HD+H reactive scattering

    SciTech Connect

    Gray, S.K.; Balint-Kurti, G.G.

    1998-01-01

    We show how to extract {bold S} matrix elements for reactive scattering from just the real part of an evolving wave packet. A three-term recursion scheme allows the real part of a wave packet to be propagated without reference to its imaginary part, so {bold S} matrix elements can be calculated efficiently. Our approach can be applied not only to the usual time-dependent Schr{umlt o}dinger equation, but to a modified form with the Hamiltonian operator {cflx H} replaced by f({cflx H}), where f is chosen for convenience. One particular choice for f, a cos{sup {minus}1} mapping, yields the Chebyshev iteration that has proved to be useful in several other recent studies. We show how reactive scattering can be studied by following time-dependent wave packets generated by this mapping. These ideas are illustrated through calculation of collinear H+H{sub 2}{r_arrow}H{sub 2}+H and three-dimensional (J=0)D+H{sub 2}{r_arrow}HD+D reactive scattering probabilities on the Liu{endash}Siegbahn{endash}Truhlar{endash}Horowitz (LSTH) potential energy surface. {copyright} {ital 1998 American Institute of Physics.}

  3. Three-dimensional Camera Phone

    NASA Astrophysics Data System (ADS)

    Iizuka, Keigo

    2004-12-01

    An inexpensive technique for realizing a three-dimensional (3D) camera phone display is presented. Light from the liquid-crystal screen of a camera phone is linearly polarized, and its direction of polarization is easily manipulated by a cellophane sheet used as a half-waveplate. The novel 3D camera phone display is made possible solely by optical components without resorting to computation, so that the 3D image is displayed in real time. Quality of the original image is not sacrificed in the process of converting it into a 3D image.

  4. Time-dependent, three-dimensional flow and mass transport during solution growth of potassium titanyl phosphate

    NASA Astrophysics Data System (ADS)

    Vartak, Bhushan; Yeckel, Andrew; Derby, Jeffrey J.

    2005-08-01

    A finite-element, numerical model is used to compute time-dependent, three-dimensional fluid flow, mass transfer, and continuum growth kinetics in the potassium titanyl phosphate (KTP) solution crystal growth system of Bordui et al. The effects of a periodically-reversing crystal rotation schedule are analyzed for two different crystal-mounting geometries. Results suggest a lower probability of the occurrence of defects when the mounting geometry is designed to take advantage of periodic flow reversal effects on the supersaturation field.

  5. Alternating-direction implicit numerical solution of the time-dependent, three-dimensional, single fluid, resistive magnetohydrodynamic equations

    SciTech Connect

    Finan, C.H. III

    1980-12-01

    Resistive magnetohydrodynamics (MHD) is described by a set of eight coupled, nonlinear, three-dimensional, time-dependent, partial differential equations. A computer code, IMP (Implicit MHD Program), has been developed to solve these equations numerically by the method of finite differences on an Eulerian mesh. In this model, the equations are expressed in orthogonal curvilinear coordinates, making the code applicable to a variety of coordinate systems. The Douglas-Gunn algorithm for Alternating-Direction Implicit (ADI) temporal advancement is used to avoid the limitations in timestep size imposed by explicit methods. The equations are solved simultaneously to avoid syncronization errors.

  6. Long-Time Numerical Integration of the Three-Dimensional Wave Equation in the Vicinity of a Moving Source

    NASA Technical Reports Server (NTRS)

    Ryabenkii, V. S.; Turchaninov, V. I.; Tsynkov, S. V.

    1999-01-01

    We propose a family of algorithms for solving numerically a Cauchy problem for the three-dimensional wave equation. The sources that drive the equation (i.e., the right-hand side) are compactly supported in space for any given time; they, however, may actually move in space with a subsonic speed. The solution is calculated inside a finite domain (e.g., sphere) that also moves with a subsonic speed and always contains the support of the right-hand side. The algorithms employ a standard consistent and stable explicit finite-difference scheme for the wave equation. They allow one to calculate tile solution for arbitrarily long time intervals without error accumulation and with the fixed non-growing amount of tile CPU time and memory required for advancing one time step. The algorithms are inherently three-dimensional; they rely on the presence of lacunae in the solutions of the wave equation in oddly dimensional spaces. The methodology presented in the paper is, in fact, a building block for constructing the nonlocal highly accurate unsteady artificial boundary conditions to be used for the numerical simulation of waves propagating with finite speed over unbounded domains.

  7. Three-dimensional multi-relaxation-time lattice Boltzmann front-tracking method for two-phase flow

    NASA Astrophysics Data System (ADS)

    Hai-Qiong, Xie; Zhong, Zeng; Liang-Qi, Zhang

    2016-01-01

    We developed a three-dimensional multi-relaxation-time lattice Boltzmann method for incompressible and immiscible two-phase flow by coupling with a front-tracking technique. The flow field was simulated by using an Eulerian grid, an adaptive unstructured triangular Lagrangian grid was applied to track explicitly the motion of the two-fluid interface, and an indicator function was introduced to update accurately the fluid properties. The surface tension was computed directly on a triangular Lagrangian grid, and then the surface tension was distributed to the background Eulerian grid. Three benchmarks of two-phase flow, including the Laplace law for a stationary drop, the oscillation of a three-dimensional ellipsoidal drop, and the drop deformation in a shear flow, were simulated to validate the present model. Project supported by the National Natural Science Foundation of China (Grant No. 11572062), the Fundamental Research Funds for the Central Universities, China (Grant No. CDJZR13248801), the Program for Changjiang Scholars and Innovative Research Team in University, China (Grant No. IRT13043), and Key Laboratory of Functional Crystals and Laser Technology, TIPC, Chinese Academy of Sciences.

  8. Three dimensional time-gated tracking of non-blinking quantum dots in live cells

    DOE PAGESBeta

    DeVore, Matthew S.; Werner, James H.; Goodwin, Peter M.; Keller, Aaron M.; Hollingsworth, Jennifer A.; Wilson, Bridget S.; Cleyrat, Cedric; Lidke, Diane S.; Ghosh, Yagnaseni; Stewart, Michael H.; et al

    2015-12-03

    Single particle tracking has provided a wealth of information about biophysical processes such as motor protein transport and diffusion in cell membranes. However, motion out of the plane of the microscope or blinking of the fluorescent probe used as a label generally limits observation times to several seconds. Here, we overcome these limitations by using novel non-blinking quantum dots as probes and employing a custom 3D tracking microscope to actively follow motion in three dimensions (3D) in live cells. As a result, signal-to-noise is improved in the cellular milieu through the use of pulsed excitation and time-gated detection.

  9. Three dimensional time-gated tracking of non-blinking quantum dots in live cells

    SciTech Connect

    DeVore, Matthew S.; Werner, James H.; Goodwin, Peter M.; Keller, Aaron M.; Hollingsworth, Jennifer A.; Wilson, Bridget S.; Cleyrat, Cedric; Lidke, Diane S.; Ghosh, Yagnaseni; Stewart, Michael H.; Stich, Dominik G.; Phipps, Mary E.

    2015-03-12

    Single particle tracking has provided a wealth of information about biophysical processes such as motor protein transport and diffusion in cell membranes. However, motion out of the plane of the microscope or blinking of the fluorescent probe used as a label generally limits observation times to several seconds. Here, we overcome these limitations by using novel non-blinking quantum dots as probes and employing a custom 3D tracking microscope to actively follow motion in three dimensions (3D) in live cells. As a result, signal-to-noise is improved in the cellular milieu through the use of pulsed excitation and time-gated detection.

  10. Three-dimensional time domain model of lightning including corona effects

    NASA Technical Reports Server (NTRS)

    Podgorski, Andrew S.

    1991-01-01

    A new 3-D lightning model that incorporates the effect of corona is described for the first time. The new model is based on a Thin Wire Time Domain Lightning (TWTDL) Code developed previously. The TWTDL Code was verified during the 1985 and 1986 lightning seasons by the measurements conducted at the 553 m CN Tower in Toronto, Ontario. The inclusion of corona in the TWTDL code allowed study of the corona effects on the lightning current parameters and the associated electric field parameters.

  11. Three dimensional time-gated tracking of non-blinking quantum dots in live cells

    PubMed Central

    DeVore, Matthew S.; Stich, Dominik G.; Keller, Aaron M.; Ghosh, Yagnaseni; Goodwin, Peter M.; Phipps, Mary E.; Stewart, Michael H.; Cleyrat, Cédric; Wilson, Bridget S.; Lidke, Diane S.; Hollingsworth, Jennifer A.; Werner, James H.

    2015-01-01

    Single particle tracking has provided a wealth of information about biophysical processes such as motor protein transport and diffusion in cell membranes. However, motion out of the plane of the microscope or blinking of the fluorescent probe used as a label generally limits observation times to several seconds. Here, we overcome these limitations by using novel non-blinking quantum dots as probes and employing a custom 3D tracking microscope to actively follow motion in three dimensions (3D) in live cells. Signal-to-noise is improved in the cellular milieu through the use of pulsed excitation and time-gated detection. PMID:25932286

  12. Parallel solution of the three-dimensional time-dependent Ginzburg- Landau equation

    SciTech Connect

    Galbreath, N.; Gropp, W.; Gunter, D.; Leaf, G.; Levine, D.

    1996-08-01

    The recent discovery of superconductivity in a class of copper-oxide compounds (the cuprate superconductors) at liquid nitrogen temperatures has generated a renewed interest in the magnetic properties of type-II superconductors. In our work, we are investigating these properties using the phenomenological time- dependent Ginzburg-Landau equation. This paper describes the parallelization of this equation.

  13. Three-dimensional space and time-dependent analysis of molten salt reactors

    SciTech Connect

    Kophazi, J.; Lathouwers, D.; Kloosterman, J. L.; Feher, S.

    2006-07-01

    This paper presents the development of a 3D time dependent calculation scheme for graphite moderated molten salt reactors (MSRs). The neutronics was modelled by diffusion and the delayed neutron precursor equations were extended with a convection term to take into account the drift of precursors. To account for the heat transfer in the fuel, a ID heat convection equation was applied. All fuel channels were calculated individually. Heat transfer in the moderator was described by the 3D heat conduction equation, thus thermally connecting the fuel channels. The computational scheme was applied for the Molten Salt Reactor Experiment (MSRE). Steady-state and time dependent simulations were carried out, including the investigation of a local fuel channel blocking event where the space dependent effects are especially relevant. (authors)

  14. Three-dimensional Euler time accurate simulations of fan rotor-stator interactions

    NASA Technical Reports Server (NTRS)

    Boretti, A. A.

    1990-01-01

    A numerical method useful to describe unsteady 3-D flow fields within turbomachinery stages is presented. The method solves the compressible, time dependent, Euler conservation equations with a finite volume, flux splitting, total variation diminishing, approximately factored, implicit scheme. Multiblock composite gridding is used to partition the flow field into a specified arrangement of blocks with static and dynamic interfaces. The code is optimized to take full advantage of the processing power and speed of the Cray Y/MP supercomputer. The method is applied to the computation of the flow field within a single stage, axial flow fan, thus reproducing the unsteady 3-D rotor-stator interaction.

  15. Real three-dimensional microfabrication for biodegradable polymers: demonstration of high-resolution and biocompatibility for implantable microdevices.

    PubMed

    Ikuta, Koji; Yamada, Akira; Niikura, Fuminori

    2004-01-01

    We have developed a novel three-dimensional (3D) microfabrication method for biodegradable polymers. Unlike conventional processes, our process satisfies high-resolution and high-speed requirements. The system design allows us the processing of microlevel forms by stacking up melted polymers from the nozzle. We adopted a batch process to supply materials in order to eliminate the prior process that required toxic solvents. In addition, it is possible to handle almost all biodegradable thermoplastic resins by adopting this system. A single layer from the piled-up layers of extruded lines was observed to evaluate the resolution. The lateral and depth resolutions attained are 40 mum and 45 mum, respectively. Biodegradable polymers enable three-dimensional microstructures such as micropipes, microbends, and microcoil springs to be manufactured in less than 15 min. The biocompatibility of the newly fabricated structure was evaluated using a cell line (PC12). For this purpose, a small vessel, with a transparent base, was fabricated using PLA and cells were cultivated in it. The results were then compared with the results obtained using the standard method. Our system renders it possible to produce toxic-free, as well as transparent and leakage-free devices. Our system is expected to have potential applications in optimum design and fabrication of implantable devices, especially in tissue engineering. PMID:17270828

  16. Time-dependent three-dimensional Petschek-type reconnection: A case study for magnetopause conditions

    NASA Astrophysics Data System (ADS)

    Biernat, H. K.; Semenov, V. S.; Rijnbeek, R. P.

    1998-03-01

    We illustrate the implications of a generalized Petschek-type reconnection model for conditions prevailing at the magnetopause. Petschek's model is generalized through the introduction of a space- and time-varying reconnection rate. Furthermore, the model can incorporate skewed magnetic fields with different magnitudes, a velocity shear, and different densities on either side of the current sheet. Here we study a situation typical for the dayside magnetopause, in which all these features are present. On a qualitative level, it is shown that the physical manifestations of reconnection include phenomena which have been observed at the magnetopause, such as accelerated plasma flows, flux transfer events, and surface waves. To aid a quantitative and more detailed comparison with experimental data, we present the results in a format which is similar to that used to view the plasma bulk parameters and magnetic field data obtained from spacecraft measurements. In particular, at several fixed positions in space we analyze the time behavior of the magnetic field and plasma parameters resulting from a localized pulse of reconnection. This exercise reveals that although there is broad agreement between the observations and expectations based on the model, several discrepancies and unexplained features still remain, such as the increase in the total pressure associated with some observations of flux transfer events. These are presumably the result of various simplifying assumptions made in the model. We also reach the new conclusion that application of the stress balance relation does not necessarily guarantee the correct identification of a rotational discontinuity traversal, and we suggest an additional identifying criterion.

  17. FEMAX finite-element package for computing three-dimensional time-domain electromagnetic fields in inhomogeneous media

    NASA Astrophysics Data System (ADS)

    Mur, G.

    An efficient and accurate finite-element package is described for computing transient as well as time-harmonic three-dimensional electromagnetic fields in inhomogeneous media. For the expansion of the field in an inhomogeneous configuration, edge elements are used along the interfaces between media with different medium properties to allow for the continuity conditions of the field across these interfaces, nodal elements are used in the remaining homogeneous subdomains. In the domain of computation the package decides locally what type of element has to be used for obtaining the user-specified accuracy of modeling the field. In this way optimum results are obtained both in regard to computational efficiency and in regard to desired accuracy. The electromagnetic compatibility relations are implemented for avoiding spurious solutions.

  18. Three-dimensional, paper-based microfluidic devices containing internal timers for running time-based diagnostic assays.

    PubMed

    Phillips, Scott T; Thom, Nicole K

    2013-01-01

    This chapter describes a method for fabricating three-dimensional (3D), paper-based microfluidic devices that contain internal timers for running quantitative, time-based assays. The method involves patterning microfluidic channels into paper, and cutting double-sided adhesive tape into defined patterns. Patterned paper and tape are assembled layer by layer to create 3D microfluidic devices that are capable of distributing microliter volumes of a sample into multiple regions on a device for conducting multiple assays simultaneously. Paraffin wax is incorporated into defined regions within the device to provide control over the distribution rate of a sample, and food coloring is included in defined regions within the device to provide an unambiguous readout when the sample has reached the bottom of the device (this latter feature is the endpoint of the timer). PMID:23329444

  19. Frequency and time domain three-dimensional inversion of electromagnetic data for a grounded-wire source

    NASA Astrophysics Data System (ADS)

    Sasaki, Yutaka; Yi, Myeong-Jong; Choi, Jihyang; Son, Jeong-Sul

    2015-01-01

    We present frequency- and time-domain three-dimensional (3-D) inversion approaches that can be applied to transient electromagnetic (TEM) data from a grounded-wire source using a PC. In the direct time-domain approach, the forward solution and sensitivity were obtained in the frequency domain using a finite-difference technique, and the frequency response was then Fourier-transformed using a digital filter technique. In the frequency-domain approach, TEM data were Fourier-transformed using a smooth-spectrum inversion method, and the recovered frequency response was then inverted. The synthetic examples show that for the time derivative of magnetic field, frequency-domain inversion of TEM data performs almost as well as time-domain inversion, with a significant reduction in computational time. In our synthetic studies, we also compared the resolution capabilities of the ground and airborne TEM and controlled-source audio-frequency magnetotelluric (CSAMT) data resulting from a common grounded wire. An airborne TEM survey at 200-m elevation achieved a resolution for buried conductors almost comparable to that of the ground TEM method. It is also shown that the inversion of CSAMT data was able to detect a 3-D resistivity structure better than the TEM inversion, suggesting an advantage of electric-field measurements over magnetic-field-only measurements.

  20. Three-dimensional visual stimulator

    NASA Astrophysics Data System (ADS)

    Takeda, Tsunehiro; Fukui, Yukio; Hashimoto, Keizo; Hiruma, Nobuyuki

    1995-02-01

    We describe a newly developed three-dimensional visual stimulator (TVS) that can change independently the directions, distances, sizes, luminance, and varieties of two sets of targets for both eyes. It consists of liquid crystal projectors (LCP's) that generate the flexible images of targets, Badal otometers that change target distances without changing the visual angles, and relay-lens systems that change target directions. A special control program is developed for real-time control of six motors and two LCP's in the TVS together with a three-dimensional optometer III that simultaneously measures eye movement, accommodation, pupil diameter, and head movement. distance, 0 to -20 D; direction, 16 horizontally and 15 vertically; size, 0-2 deg visual angle; and luminance, 10-2-10 2 cd/m2. The target images are refreshed at 60 Hz and speeds with which the target makes a smooth change (ramp stimuli) are size, 10 deg/s. A simple application demonstrates the performance.

  1. Technique for designing and evaluating probe caps used in optical topography of infants using a real head model based on three dimensional magnetic resonance images

    NASA Astrophysics Data System (ADS)

    Hirabayashi, Yukiko; Sato, Hiroki; Uchida-Ota, Mariko; Nakai, Akio; Maki, Atsushi

    2008-06-01

    We have developed an effective technique for aiding the design and evaluating the performance of the probe caps used to perform optical topography (OT) on infants. To design and evaluate a probe cap, it is necessary to determine the measurement positions for conducting OT on the brain surface of subjects. One technique for determining these positions on the brain surface is to find their three-dimensional (3D) coordinates using a 3D magnetic space digitizer, which consists of a 3D magnetic source and a 3D magnetic sensor. The problem with this technique is that it takes a long time to determine all the measurement points on the subject's head and it is difficult to use with infants. It is a particular problem with infants who cannot support their own heads. Therefore, we have developed a real model of an infant subject's head based on 3D magnetic resonance (MR) images. The model is made from an optical-curable resin using 3D computer-aided-format coordinate data taken from 3D MR image-format coordinate data. We have determined the measurement positions on the surface of the model corresponding to a scalp using a 3D magnetic space digitizer and displayed the positions on a 3D MR image of the infant's brain. Using this technique, we then determined the actual 72 measurement positions located over the entire brain surface area for use with our new whole-head probe cap for neonates and infants. This method is useful for evaluating the performance of and designing probe caps.

  2. TIME EVOLUTION OF THE THREE-DIMENSIONAL ACCRETION FLOWS: EFFECTS OF THE ADIABATIC INDEX AND OUTER BOUNDARY CONDITION

    SciTech Connect

    Janiuk, Agnieszka; Sznajder, Maciej; Moscibrodzka, Monika; Proga, Daniel

    2009-11-10

    We study a slightly rotating accretion flow onto a black hole, using the fully three-dimensional (3D) numerical simulations. We consider hydrodynamics of an inviscid flow, assuming a spherically symmetric density distribution at the outer boundary and a small, latitude-dependent angular momentum. We investigate the role of the adiabatic index and gas temperature, and the flow behavior due to non-axisymmetric effects. Our 3D simulations confirm axisymmetric results: the material that has too much angular momentum to be accreted forms a thick torus near the equator, and the mass accretion rate is lower than the Bondi rate. In our previous study of the 3D accretion flows, for gamma = 5/3, we found that the inner torus precessed, even for axisymmetric conditions at large radii. The present study shows that the inner torus precesses also for other values of the adiabatic index: gamma = 4/3, 1.2, and 1.01. However, the time for the precession to set increases with decreasing gamma. In particular, for gamma = 1.01, we find that depending on the outer boundary conditions, the torus may shrink substantially due to the strong inflow of the non-rotating matter, and the precession will have insufficient time to develop. On the other hand, if the torus is supplied by the continuous inflow of the rotating material from the outer radii, its inner parts will eventually tilt and precess, as was for the larger gamma's.

  3. Off-equilibrium scaling behaviors driven by time-dependent external fields in three-dimensional O (N ) vector models

    NASA Astrophysics Data System (ADS)

    Pelissetto, Andrea; Vicari, Ettore

    2016-03-01

    We consider the dynamical off-equilibrium behavior of the three-dimensional O (N ) vector model in the presence of a slowly varying time-dependent spatially uniform magnetic field H (t )=h (t )e , where e is an N -dimensional constant unit vector, h (t ) =t /ts , and ts is a time scale, at fixed temperature T ≤Tc , where Tc corresponds to the continuous order-disorder transition. The dynamic evolutions start from equilibrium configurations at hi<0 , correspondingly ti<0 , and end at time tf>0 with h (tf)>0 , or vice versa. We show that the magnetization displays an off-equilibrium scaling behavior close to the transition line H (t )=0 . It arises from the interplay among the time t , the time scale ts, and the finite size L . The scaling behavior can be parametrized in terms of the scaling variables tsκ/L and t /tsκt , where κ >0 and κt>0 are appropriate universal exponents, which differ at the critical point and for T time dependence of the external field. We define a scaling function for the hysteresis loop area of the magnetization that can be used to quantify how far the system is from equilibrium.

  4. Three-dimensional laser microvision.

    PubMed

    Shimotahira, H; Iizuka, K; Chu, S C; Wah, C; Costen, F; Yoshikuni, Y

    2001-04-10

    A three-dimensional (3-D) optical imaging system offering high resolution in all three dimensions, requiring minimum manipulation and capable of real-time operation, is presented. The system derives its capabilities from use of the superstructure grating laser source in the implementation of a laser step frequency radar for depth information acquisition. A synthetic aperture radar technique was also used to further enhance its lateral resolution as well as extend the depth of focus. High-speed operation was made possible by a dual computer system consisting of a host and a remote microcomputer supported by a dual-channel Small Computer System Interface parallel data transfer system. The system is capable of operating near real time. The 3-D display of a tunneling diode, a microwave integrated circuit, and a see-through image taken by the system operating near real time are included. The depth resolution is 40 mum; lateral resolution with a synthetic aperture approach is a fraction of a micrometer and that without it is approximately 10 mum. PMID:18357177

  5. Analytical solitonlike solutions and the dynamics of ultracold Fermi gases in a time-dependent three-dimensional harmonic potential

    NASA Astrophysics Data System (ADS)

    Wang, Ying; Luo, Guosen; Zhou, Yu; Hang, Chao

    2015-09-01

    We present a theoretical study of solitonlike solutions and their dynamics of ultracold superfluid Fermi gases trapped in a time-dependent three-dimensional (3D) harmonic potential with gain or loss. The 3D analytical solitonlike solutions are obtained without introducing any additional integrability constraints used elsewhere. The propagation of both bright- and dark-soliton-like solutions is investigated. We show that the amplitudes of dark-soliton-like solutions exhibit periodic oscillation, whereas those of the bright-soliton-like ones do not show such behavior. Moreover, we highlight that the oscillation periods of dark-soliton-like solutions predicted by our approach are matched very well with those observed in a recent experiment carried out by Yefsah et al. [T. Yefsah, A. T. Sommer, M. J. H. Ku, L. W. Cheuk, W. Ji, W. S. Bakr, and M. W. Zwierlein, Nature (London) 499, 426 (2013), 10.1038/nature12338] in both Bose-Einstein condensation and unitarity regimes.

  6. Analytical solitonlike solutions and the dynamics of ultracold Fermi gases in a time-dependent three-dimensional harmonic potential.

    PubMed

    Wang, Ying; Luo, Guosen; Zhou, Yu; Hang, Chao

    2015-09-01

    We present a theoretical study of solitonlike solutions and their dynamics of ultracold superfluid Fermi gases trapped in a time-dependent three-dimensional (3D) harmonic potential with gain or loss. The 3D analytical solitonlike solutions are obtained without introducing any additional integrability constraints used elsewhere. The propagation of both bright- and dark-soliton-like solutions is investigated. We show that the amplitudes of dark-soliton-like solutions exhibit periodic oscillation, whereas those of the bright-soliton-like ones do not show such behavior. Moreover, we highlight that the oscillation periods of dark-soliton-like solutions predicted by our approach are matched very well with those observed in a recent experiment carried out by Yefsah et al. [T. Yefsah, A. T. Sommer, M. J. H. Ku, L. W. Cheuk, W. Ji, W. S. Bakr, and M. W. Zwierlein, Nature (London) 499, 426 (2013)NATUAS0028-083610.1038/nature12338] in both Bose-Einstein condensation and unitarity regimes. PMID:26465543

  7. Effect of short-term exposure to stereoscopic three-dimensional flight displays on real-world depth perception

    NASA Technical Reports Server (NTRS)

    Busquets, Anthony M.; Parrish, Russell V.; Williams, Steven P.

    1991-01-01

    High-fidelity color pictorial displays that incorporate depth cues in the display elements are currently available. Depth cuing applied to advanced head-down flight display concepts potentially enhances the pilot's situational awareness and improves task performance. Depth cues provided by stereopsis exhibit constraints that must be fully understood so depth cuing enhancements can be adequately realized and exploited. A fundamental issue (the goal of this investigation) is whether the use of head-down stereoscopic displays in flight applications degrade the real-world depth perception of pilots using such displays. Stereoacuity tests are used in this study as the measure of interest. Eight pilots flew repeated simulated landing approaches using both nonstereo and stereo 3-D head-down pathway-in-the-sky displays. At this decision height of each approach (where the pilot changes to an out-the-window view to obtain real-world visual references) the pilots changed to a stereoacuity test that used real objects. Statistical analysis of stereoacuity measures (data for a control condition of no exposure to any electronic flight display compared with data for changes from nonstereo and from stereo displays) reveals no significant differences for any of the conditions. Therefore, changing from short-term exposure to a head-down stereo display has no more effect on real-world relative depth perception than does changing from a nonstereo display. However, depth perception effects based on sized and distance judgements and on long-term exposure remain issues to be investigated.

  8. Issues in measure-preserving three dimensional flow integrators: Self-adjointness, reversibility, and non-uniform time stepping

    SciTech Connect

    Finn, John M.

    2015-03-01

    Properties of integration schemes for solenoidal fields in three dimensions are studied, with a focus on integrating magnetic field lines in a plasma using adaptive time stepping. It is shown that implicit midpoint (IM) and a scheme we call three-dimensional leapfrog (LF) can do a good job (in the sense of preserving KAM tori) of integrating fields that are reversible, or (for LF) have a 'special divergence-free' property. We review the notion of a self-adjoint scheme, showing that such schemes are at least second order accurate and can always be formed by composing an arbitrary scheme with its adjoint. We also review the concept of reversibility, showing that a reversible but not exactly volume-preserving scheme can lead to a fractal invariant measure in a chaotic region, although this property may not often be observable. We also show numerical results indicating that the IM and LF schemes can fail to preserve KAM tori when the reversibility property (and the SDF property for LF) of the field is broken. We discuss extensions to measure preserving flows, the integration of magnetic field lines in a plasma and the integration of rays for several plasma waves. The main new result of this paper relates to non-uniform time stepping for volume-preserving flows. We investigate two potential schemes, both based on the general method of Ref. [11], in which the flow is integrated in split time steps, each Hamiltonian in two dimensions. The first scheme is an extension of the method of extended phase space, a well-proven method of symplectic integration with non-uniform time steps. This method is found not to work, and an explanation is given. The second method investigated is a method based on transformation to canonical variables for the two split-step Hamiltonian systems. This method, which is related to the method of non-canonical generating functions of Ref. [35], appears to work very well.

  9. Three Dimensional Fusion CT Decreases Radiation Exposure, Procedure Time and Contrast Use during Fenestrated Endovascular Aortic Repair

    PubMed Central

    McNally, Michael M.; Scali, Salvatore T.; Feezor, Robert J.; Neal, Daniel; Huber, Thomas S.; Beck, Adam W.

    2014-01-01

    Objectives Endovascular surgery has revolutionized the treatment of aortic aneurysms; however these improvements have come at the cost of increased radiation and contrast exposure, particularly for more complex procedures. Three dimensional (3D) fusion computed tomographic (CT) imaging is a new technology that may facilitate these repairs. The purpose of this analysis was to determine the impact of utilizing intraoperative 3D fusion CT on performance of fenestrated endovascular aortic repair. Methods A review of our institutional database was performed to identify patients undergoing fenestrated/branched endovascular aortic repair (FEVAR). Subjects treated using 3D fusion CT were compared to patients treated in the immediate 12-month period prior to implementation of this technology when procedures were performed in a standard hybrid operating room without CT fusion capabilities. Primary endpoints included patient radiation exposure (air kerma area product: milliGray; mGy*cm2), fluoroscopy time (minutes; min), contrast usage (mL) and procedure time (min). Patients were grouped by number of aortic graft fenestrations revascularized with a stentgraft and operative outcomes were compared. Results A total of 72 patients (N = 41 before vs. N = 31 after 3D fusion CT implementation) underwent FEVAR from September 2012 through March 2014. For 2-vessel fenestrated endografts, there was a significant decrease in radiation exposure (3400±1900 vs. 1380±520 mGy*cm2; P=.001), fluoroscopy time (63±29 vs. 41±11min; P=.02), and contrast usage (69±16 vs. 26±8 mL; P=.0002) with intraoperative 3D fusion CT. Similarly, for combined 3 and 4-vessel FEVAR, significantly decreased radiation exposure (5400±2225 vs. 2700±1400 mGy*cm2; P<.0001), fluoroscopy time (89±36 vs 6±21min; P=.02), contrast usage (90±25 vs. 39±17mL; P<.0001), as well as procedure time (330±100 vs. 230±50min; P=.002) was noted. Estimated blood loss was significantly less (P<.0001) and length of stay had a

  10. Transport and residence times of tropospheric aerosols inferred from a global three-dimensional simulation of Pb-210

    NASA Technical Reports Server (NTRS)

    Balkanski, Yves J.; Jacob, Daniel J.; Gardner, Geraldine M.; Graustein, William C.; Turekian, Karl K.

    1993-01-01

    A global three-dimensional model is used to investigate the transport and tropospheric residence time of Pb-210, an aerosol tracer produced in the atmosphere by radioactive decay of Rn-222 emitted from soils. The model uses meteorological input with 4 deg x 5 deg horizontal resolution and 4-hour temporal resolution from the Goddard Institute for Space Studies general circulation model (GCM). It computes aerosol scavenging by convective precipitation as part of the wet convective mass transport operator in order to capture the coupling between vertical transport and rainout. Scavenging in convective precipitation accounts for 74% of the global Pb-210 sink in the model; scavenging in large-scale precipitation accounts for 12%, and scavenging in dry deposition accounts for 14%. The model captures 63% of the variance of yearly mean Pb-210 concentrations measured at 85 sites around the world with negligible mean bias, lending support to the computation of aerosol scavenging. There are, however, a number of regional and seasonal discrepancies that reflect in part anomalies in GCM precipitation. Computed residence times with respect to deposition for Pb-210 aerosol in the tropospheric column are about 5 days at southern midlatitudes and 10-15 days in the tropics; values at northern midlatitudes vary from about 5 days in winter to 10 days in summer. The residence time of Pb-210 produced in the lowest 0.5 km of atmosphere is on average four times shorter than that of Pb-210 produced in the upper atmosphere. Both model and observations indicate a weaker decrease of Pb-210 concentrations between the continental mixed layer and the free troposphere than is observed for total aerosol concentrations; an explanation is that Rn-222 is transported to high altitudes in wet convective updrafts, while aerosols and soluble precursors of aerosols are scavenged by precipitation in the updrafts. Thus Pb-210 is not simply a tracer of aerosols produced in the continental boundary layer, but

  11. Issues in measure-preserving three dimensional flow integrators: Self-adjointness, reversibility, and non-uniform time stepping

    SciTech Connect

    Finn, John M.

    2015-03-15

    Properties of integration schemes for solenoidal fields in three dimensions are studied, with a focus on integrating magnetic field lines in a plasma using adaptive time stepping. It is shown that implicit midpoint (IM) and a scheme we call three-dimensional leapfrog (LF) can do a good job (in the sense of preserving KAM tori) of integrating fields that are reversible, or (for LF) have a “special divergence-free” (SDF) property. We review the notion of a self-adjoint scheme, showing that such schemes are at least second order accurate and can always be formed by composing an arbitrary scheme with its adjoint. We also review the concept of reversibility, showing that a reversible but not exactly volume-preserving scheme can lead to a fractal invariant measure in a chaotic region, although this property may not often be observable. We also show numerical results indicating that the IM and LF schemes can fail to preserve KAM tori when the reversibility property (and the SDF property for LF) of the field is broken. We discuss extensions to measure preserving flows, the integration of magnetic field lines in a plasma and the integration of rays for several plasma waves. The main new result of this paper relates to non-uniform time stepping for volume-preserving flows. We investigate two potential schemes, both based on the general method of Feng and Shang [Numer. Math. 71, 451 (1995)], in which the flow is integrated in split time steps, each Hamiltonian in two dimensions. The first scheme is an extension of the method of extended phase space, a well-proven method of symplectic integration with non-uniform time steps. This method is found not to work, and an explanation is given. The second method investigated is a method based on transformation to canonical variables for the two split-step Hamiltonian systems. This method, which is related to the method of non-canonical generating functions of Richardson and Finn [Plasma Phys. Controlled Fusion 54, 014004 (2012

  12. Issues in measure-preserving three dimensional flow integrators: Self-adjointness, reversibility, and non-uniform time stepping

    DOE PAGESBeta

    Finn, John M.

    2015-03-01

    Properties of integration schemes for solenoidal fields in three dimensions are studied, with a focus on integrating magnetic field lines in a plasma using adaptive time stepping. It is shown that implicit midpoint (IM) and a scheme we call three-dimensional leapfrog (LF) can do a good job (in the sense of preserving KAM tori) of integrating fields that are reversible, or (for LF) have a 'special divergence-free' property. We review the notion of a self-adjoint scheme, showing that such schemes are at least second order accurate and can always be formed by composing an arbitrary scheme with its adjoint. Wemore » also review the concept of reversibility, showing that a reversible but not exactly volume-preserving scheme can lead to a fractal invariant measure in a chaotic region, although this property may not often be observable. We also show numerical results indicating that the IM and LF schemes can fail to preserve KAM tori when the reversibility property (and the SDF property for LF) of the field is broken. We discuss extensions to measure preserving flows, the integration of magnetic field lines in a plasma and the integration of rays for several plasma waves. The main new result of this paper relates to non-uniform time stepping for volume-preserving flows. We investigate two potential schemes, both based on the general method of Ref. [11], in which the flow is integrated in split time steps, each Hamiltonian in two dimensions. The first scheme is an extension of the method of extended phase space, a well-proven method of symplectic integration with non-uniform time steps. This method is found not to work, and an explanation is given. The second method investigated is a method based on transformation to canonical variables for the two split-step Hamiltonian systems. This method, which is related to the method of non-canonical generating functions of Ref. [35], appears to work very well.« less

  13. Three-dimensional accurate detection of lung emphysema in rats using ultra-short and zero echo time MRI.

    PubMed

    Bianchi, Andrea; Tibiletti, Marta; Kjørstad, Åsmund; Birk, Gerald; Schad, Lothar R; Stierstorfer, Birgit; Rasche, Volker; Stiller, Detlef

    2015-11-01

    Emphysema is a life-threatening pathology that causes irreversible destruction of alveolar walls. In vivo imaging techniques play a fundamental role in the early non-invasive pre-clinical and clinical detection and longitudinal follow-up of this pathology. In the present study, we aimed to evaluate the feasibility of using high resolution radial three-dimensional (3D) zero echo time (ZTE) and 3D ultra-short echo time (UTE) MRI to accurately detect lung pathomorphological changes in a rodent model of emphysema.Porcine pancreas elastase (PPE) was intratracheally administered to the rats to produce the emphysematous changes. 3D ZTE MRI, low and high definition 3D UTE MRI and micro-computed tomography images were acquired 4 weeks after the PPE challenge. Signal-to-noise ratios (SNRs) were measured in PPE-treated and control rats. T2* values were computed from low definition 3D UTE MRI. Histomorphometric measurements were made after euthanizing the animals. Both ZTE and UTE MR images showed a significant decrease in the SNR measured in PPE-treated lungs compared with controls, due to the pathomorphological changes taking place in the challenged lungs. A significant decrease in T2* values in PPE-challenged animals compared with controls was measured using UTE MRI. Histomorphometric measurements showed a significant increase in the mean linear intercept in PPE-treated lungs. UTE yielded significantly higher SNR compared with ZTE (14% and 30% higher in PPE-treated and non-PPE-treated lungs, respectively).This study showed that optimized 3D radial UTE and ZTE MRI can provide lung images of excellent quality, with high isotropic spatial resolution (400 µm) and SNR in parenchymal tissue (>25) and negligible motion artifacts in freely breathing animals. These techniques were shown to be useful non-invasive instruments to accurately and reliably detect the pathomorphological alterations taking place in emphysematous lungs, without incurring the risks of cumulative radiation

  14. Nested multigrid vector and scalar potential finite element method for three-dimensional time-harmonic electromagnetic analysis

    NASA Astrophysics Data System (ADS)

    Zhu, Yu; Cangellaris, Andreas C.

    2002-05-01

    A new finite element methodology is presented for fast and robust numerical simulation of three-dimensional electromagnetic wave phenomena. The new methodology combines nested multigrid techniques with the ungauged vector and scalar potential formulation of the finite element method. The finite element modeling is performed on nested meshes over the computational domain of interest. The iterative solution of the finite element matrix on the finest mesh is performed using the conjugate gradient method, while the nested multigrid vector and scalar potential algorithm acts as the preconditioner for the iterative solver. Numerical experiments from the application of the new methodology to three-dimensional electromagnetic scattering are used to demonstrate its superior numerical convergence and efficient memory usage.

  15. [Real time 3D echocardiography].

    PubMed

    Bauer, F; Shiota, T; Thomas, J D

    2001-07-01

    Three-dimensional representation of the heart is an old concern. Usually, 3D reconstruction of the cardiac mass is made by successive acquisition of 2D sections, the spatial localisation and orientation of which require complex guiding systems. More recently, the concept of volumetric acquisition has been introduced. A matricial emitter-receiver probe complex with parallel data processing provides instantaneous of a pyramidal 64 degrees x 64 degrees volume. The image is restituted in real time and is composed of 3 planes (planes B and C) which can be displaced in all spatial directions at any time during acquisition. The flexibility of this system of acquisition allows volume and mass measurement with greater accuracy and reproducibility, limiting inter-observer variability. Free navigation of the planes of investigation allows reconstruction for qualitative and quantitative analysis of valvular heart disease and other pathologies. Although real time 3D echocardiography is ready for clinical usage, some improvements are still necessary to improve its conviviality. Then real time 3D echocardiography could be the essential tool for understanding, diagnosis and management of patients. PMID:11494630

  16. [Real time 3D echocardiography

    NASA Technical Reports Server (NTRS)

    Bauer, F.; Shiota, T.; Thomas, J. D.

    2001-01-01

    Three-dimensional representation of the heart is an old concern. Usually, 3D reconstruction of the cardiac mass is made by successive acquisition of 2D sections, the spatial localisation and orientation of which require complex guiding systems. More recently, the concept of volumetric acquisition has been introduced. A matricial emitter-receiver probe complex with parallel data processing provides instantaneous of a pyramidal 64 degrees x 64 degrees volume. The image is restituted in real time and is composed of 3 planes (planes B and C) which can be displaced in all spatial directions at any time during acquisition. The flexibility of this system of acquisition allows volume and mass measurement with greater accuracy and reproducibility, limiting inter-observer variability. Free navigation of the planes of investigation allows reconstruction for qualitative and quantitative analysis of valvular heart disease and other pathologies. Although real time 3D echocardiography is ready for clinical usage, some improvements are still necessary to improve its conviviality. Then real time 3D echocardiography could be the essential tool for understanding, diagnosis and management of patients.

  17. Three-dimensional viscoelastic time-domain finite-difference seismic modelling using the staggered Adams-Bashforth time integrator

    NASA Astrophysics Data System (ADS)

    Bohlen, Thomas; Wittkamp, Florian

    2016-03-01

    We analyse the performance of a higher order accurate staggered viscoelastic time-domain finite-difference method, in which the staggered Adams-Bashforth (ABS) third-order and fourth-order accurate time integrators are used for temporal discretization. ABS is a multistep method that uses previously calculated wavefields to increase the order of accuracy in time. The analysis shows that the numerical dispersion is much lower than that of the widely used second-order leapfrog method. Numerical dissipation is introduced by the ABS method which is significantly smaller for fourth-order than third-order accuracy. In 1-D and 3-D simulation experiments, we verify the convincing improvements of simulation accuracy of the fourth-order ABS method. In a realistic elastic 3-D scenario, the computing time reduces by a factor of approximately 2.4, whereas the memory requirements increase by approximately a factor of 2.2. The ABS method thus provides an alternative strategy to increase the simulation accuracy in time by investing computer memory instead of computing time.

  18. Monitoring groundwater-surface water interaction using time-series and time-frequency analysis of transient three-dimensional electrical resistivity changes

    SciTech Connect

    Johnson, Timothy C.; Slater, Lee; Ntarlagiannis, Dimitrios; Day-Lewis, Frederick D.; Elwaseif, Mehrez

    2012-08-22

    Time-lapse resistivity imaging is increasingly used to monitor hydrologic processes. Compared to conventional hydrologic measurements, surface time-lapse resistivity provides (1) superior spatial coverage in two or three dimensions, (2) potentially high-resolution information in time, and (3) information in the absence of wells. However, interpretation of time-lapse electrical tomograms is complicated by the ever increasing size and complexity of long-term, three-dimensional time-series conductivity datasets. Here, we use three-dimensional (3D) surface time-lapse electrical imaging to monitor subsurface electrical conductivity variations associated with stage-driven groundwater/surface-water interaction along a stretch of the Columbia River adjacent to the Hanford 300 Area, Hanford WA, USA. We reduce the resulting 3D conductivity time series using both correlation and time-frequency analysis to isolate a paleochannel causing enhanced groundwater/river-water interaction. Correlation analysis on the time-lapse imaging results concisely represents enhanced ground water/surface-water interaction within the paleochannel, and provides information concerning groundwater flow velocities. Time-frequency analysis using the Stockwell (S) Transform provides additional information by 1) identifying the stage periodicities driving ground water/river-water interaction due to upstream dam operations, 2) identifying segments in time-frequency space when these interactions are most active. These results provide new insight into the distribution and timing of river water intrusion into the Hanford 300 area, which has a governing influence on the behavior of a uranium plume left over from historical nuclear fuel processing operations.

  19. Three-dimensional finite-difference time-domain modelling of photonic crystal surface-emitting lasers

    NASA Astrophysics Data System (ADS)

    Ivanov, Pavlo; Taylor, Richard J. E.; Li, Guangrui; Childs, David T. D.; Khamas, Salam; Sarma, Jayanta; Erdelyi, Robertus; Hogg, Richard A.

    2016-03-01

    We investigate the beam divergence in far-field region, diffraction loss and optical confinement factors of all-semiconductor and void-semiconductor photonic-crystal surface-emitting lasers (PCSELs), containing either InGaP/GaAs or InGaP/air photonic crystals using a three-dimensional FDTD model. We explore the impact of changing the PC hole shape, size, and lattice structure in addition to the choice of all-semiconductor or void-semiconductor designs. We discuss the determination of the threshold gain from the diffraction losses, and explore limitations to direct modulation of the PCSEL.

  20. Dynamic Three-Dimensional Echocardiography

    NASA Astrophysics Data System (ADS)

    Matsusaka, Katsuhiko; Doi, Motonori; Oshiro, Osamu; Chihara, Kunihiro

    2000-08-01

    Conventional three-dimensional (3D) ultrasound imaging equipment for diagnosis requires much time to reconstruct 3D images or fix the view point for observing the 3D image. Thus, it is inconvenient for cardiac diagnosis. In this paper, we propose a new dynamic 3D echocardiography system. The system produces 3D images in real-time and permits changes in view point. This system consists of ultrasound diagnostic equipment, a digitizer and a computer. B-mode images are projected to a virtual 3D space by referring to the position of the probe of the ultrasound diagnosis equipment. The position is obtained by the digitizer to which the ultrasound probe is attached. The 3D cardiac image is constructed from B-mode images obtained simultaneously in the cardiac cycle. To obtain the same moment of heartbeat in the cardiac cycle, this system uses the electrocardiography derived from the diagnosis equipment. The 3D images, which show various scenes of the stage of heartbeat action, are displayed sequentially. The doctor can observe 3D images cut in any plane by pushing a button of the digitizer and zooming with the keyboard. We evaluated our prototype system by observation of a mitral valve in motion.

  1. Study of ion-ion plasma formation in negative ion sources by a three-dimensional in real space and three-dimensional in velocity space particle in cell model

    NASA Astrophysics Data System (ADS)

    Nishioka, S.; Goto, I.; Miyamoto, K.; Hatayama, A.; Fukano, A.

    2016-01-01

    Recently, in large-scale hydrogen negative ion sources, the experimental results have shown that ion-ion plasma is formed in the vicinity of the extraction hole under the surface negative ion production case. The purpose of this paper is to clarify the mechanism of the ion-ion plasma formation by our three dimensional particle-in-cell simulation. In the present model, the electron loss along the magnetic filter field is taken into account by the " √{τ///τ⊥ } model." The simulation results show that the ion-ion plasma formation is due to the electron loss along the magnetic filter field. Moreover, the potential profile for the ion-ion plasma case has been looked into carefully in order to discuss the ion-ion plasma formation. Our present results show that the potential drop of the virtual cathode in front of the plasma grid is large when the ion-ion plasma is formed. This tendency has been explained by a relationship between the virtual cathode depth and the net particle flux density at the virtual cathode.

  2. High speed three-dimensional laser scanner with real time processing

    NASA Technical Reports Server (NTRS)

    Lavelle, Joseph P. (Inventor); Schuet, Stefan R. (Inventor)

    2008-01-01

    A laser scanner computes a range from a laser line to an imaging sensor. The laser line illuminates a detail within an area covered by the imaging sensor, the area having a first dimension and a second dimension. The detail has a dimension perpendicular to the area. A traverse moves a laser emitter coupled to the imaging sensor, at a height above the area. The laser emitter is positioned at an offset along the scan direction with respect to the imaging sensor, and is oriented at a depression angle with respect to the area. The laser emitter projects the laser line along the second dimension of the area at a position where a image frame is acquired. The imaging sensor is sensitive to laser reflections from the detail produced by the laser line. The imaging sensor images the laser reflections from the detail to generate the image frame. A computer having a pipeline structure is connected to the imaging sensor for reception of the image frame, and for computing the range to the detail using height, depression angle and/or offset. The computer displays the range to the area and detail thereon covered by the image frame.

  3. Vortex rings in ferromagnets: Numerical simulations of the time-dependent three-dimensional Landau-Lifshitz equation

    SciTech Connect

    Sutcliffe, Paul

    2007-11-01

    Vortex ring solutions are presented for the Landau-Lifshitz equation, which models the dynamics of a three-dimensional ferromagnet. The vortex rings propagate at constant speed along their symmetry axis and are characterized by the integer-valued Hopf charge. They are stable to axial perturbations, but it is demonstrated that an easy axis anisotropy results in an instability to perturbations, which breaks the axial symmetry. The unstable mode corresponds to a migration of spin flips around the vortex ring that leads to a pinching instability and, ultimately, the collapse of the vortex ring. It is found that this instability does not exist for an isotropic ferromagnet. Similarities between vortex rings in ferromagnets and vortons in cosmology are noted.

  4. Three dimensional finite difference time domain modeling of Schumann resonances on Earth and other planets of the solar system

    NASA Astrophysics Data System (ADS)

    Yang, Heng

    2007-12-01

    Resonance properties of the Earth-ionosphere cavity were predicted by W. O. Schumann in 1952. Since then observations of electromagnetic signals in the frequency range 1-500 Hz have become a powerful tool for variety of remote sensing applications, which in recent years included studies of thunderstorm related transient luminous events in the middle atmosphere and related lightning discharges. In this thesis, a three dimensional Finite Difference Time Domain (FDTD) model is developed to study the propagation of the extremely low frequency (ELF) waves in the Earth-ionosphere cavity and in similar cavities on other celestial bodies of the Solar System. A comparison of the results from this FDTD model with a set of classical eigen-frequency (fn) and quality factor ( Qn) solutions for laterally uniform spherically symmetric Earth-ionosphere cavity and with recent observations of Schumann resonance (SR) during solar proton events (SPEs) and X-ray bursts is provided. The FDTD fn and Qn solutions for the uniform cavity appear to be in excellent agreement (within several %) with well-known experimental results documented in the literature. The related analysis indicates that the frequency of the first SR mode decreases during SPEs and increases during X-ray bursts by a fraction of a Hz, in agreement with physical arguments presented in previously published literature and with observations. The FDTD model is extended to include the effects of the geomagnetic field on SR parameters. A higher penetration height of SR electric and magnetic components is found with the presence of the geomagnetic field. In a realistic cavity, the conductivity distribution is not laterally uniform and spherically symmetric, but varies with local time and seasons reflecting related variations in the effects of solar radiation on the conductivity of the lower ionosphere. The global lightning activity in the three main areas (Africa, South-East Asia, and South America) also has diurnal and seasonal

  5. Real-time analysis keratometer

    NASA Technical Reports Server (NTRS)

    Adachi, Iwao P. (Inventor); Adachi, Yoshifumi (Inventor); Frazer, Robert E. (Inventor)

    1987-01-01

    A computer assisted keratometer in which a fiducial line pattern reticle illuminated by CW or pulsed laser light is projected on a corneal surface through lenses, a prismoidal beamsplitter quarterwave plate, and objective optics. The reticle surface is curved as a conjugate of an ideal corneal curvature. The fiducial image reflected from the cornea undergoes a polarization shift through the quarterwave plate and beamsplitter whereby the projected and reflected beams are separated and directed orthogonally. The reflected beam fiducial pattern forms a moire pattern with a replica of the first recticle. This moire pattern contains transverse aberration due to differences in curvature between the cornea and the ideal corneal curvature. The moire pattern is analyzed in real time by computer which displays either the CW moire pattern or a pulsed mode analysis of the transverse aberration of the cornea under observation, in real time. With the eye focused on a plurality of fixation points in succession, a survey of the entire corneal topography is made and a contour map or three dimensional plot of the cornea can be made as a computer readout in addition to corneal radius and refractive power analysis.

  6. Improvement of depth resolution and detection efficiency by control of secondary-electrons in single-event three-dimensional time-of-flight Rutherford backscattering spectrometry

    NASA Astrophysics Data System (ADS)

    Abo, Satoshi; Hamada, Yasuhisa; Seidl, Albert; Wakaya, Fujio; Takai, Mikio

    2015-04-01

    An improvement of a depth resolution and a detection efficiency in single-event three-dimensional time-of-flight (TOF) Rutherford backscattering spectrometry (RBS) is discussed on both simulation and experiment by control of secondary electron trajectories using sample bias voltage. The secondary electron, used for a start signal in single-event TOF-RBS, flies more directly to a secondary electron detector with the positive sample bias voltage of several tens of volt than that without sample bias voltage in the simulation. The simulated collection efficiency of the secondary electrons also increases with the positive sample bias voltage of several tens of volt. These simulation results indicate the possibility of a smaller depth resolution and a shorter measurement time in single-event TOF-RBS with positive sample bias voltage. The measurement time for the Pt-stripe sample using single-event three-dimensional TOF-RBS with the sample bias voltage of +100 V is 65% shorter than that without sample bias voltage, resulting in a less sample damage by a probe beam. The depth resolution for the Pt stripes under the 50-nm-thick SiO2 cover-layer with the sample bias voltage of +100 V is 4 nm smaller than that without sample bias voltage. Positive sample bias voltage improves the depth resolution and the detection efficiency in single-event three-dimensional TOF-RBS without an influence on the beam focusing.

  7. Monitoring groundwater-surface water interaction using time-series and time-frequency analysis of transient three-dimensional electrical resistivity changes

    USGS Publications Warehouse

    Johnson, Timothy C.; Slater, Lee D.; Ntarlagiannis, Dimitris; Day-Lewis, Frederick D.; Elwaseif, Mehrez

    2012-01-01

    Time-lapse resistivity imaging is increasingly used to monitor hydrologic processes. Compared to conventional hydrologic measurements, surface time-lapse resistivity provides superior spatial coverage in two or three dimensions, potentially high-resolution information in time, and information in the absence of wells. However, interpretation of time-lapse electrical tomograms is complicated by the ever-increasing size and complexity of long-term, three-dimensional (3-D) time series conductivity data sets. Here we use 3-D surface time-lapse electrical imaging to monitor subsurface electrical conductivity variations associated with stage-driven groundwater-surface water interactions along a stretch of the Columbia River adjacent to the Hanford 300 near Richland, Washington, USA. We reduce the resulting 3-D conductivity time series using both time-series and time-frequency analyses to isolate a paleochannel causing enhanced groundwater-surface water interactions. Correlation analysis on the time-lapse imaging results concisely represents enhanced groundwater-surface water interactions within the paleochannel, and provides information concerning groundwater flow velocities. Time-frequency analysis using the Stockwell (S) transform provides additional information by identifying the stage periodicities driving groundwater-surface water interactions due to upstream dam operations, and identifying segments in time-frequency space when these interactions are most active. These results provide new insight into the distribution and timing of river water intrusion into the Hanford 300 Area, which has a governing influence on the behavior of a uranium plume left over from historical nuclear fuel processing operations.

  8. Three-dimensional metamaterials

    DOEpatents

    Burckel, David Bruce

    2012-06-12

    A fabrication method is capable of creating canonical metamaterial structures arrayed in a three-dimensional geometry. The method uses a membrane suspended over a cavity with predefined pattern as a directional evaporation mask. Metallic and/or dielectric material can be evaporated at high vacuum through the patterned membrane to deposit resonator structures on the interior walls of the cavity, thereby providing a unit cell of micron-scale dimension. The method can produce volumetric metamaterial structures comprising layers of such unit cells of resonator structures.

  9. Three Dimensional Dirac Semimetals

    NASA Astrophysics Data System (ADS)

    Zaheer, Saad

    2014-03-01

    Dirac points on the Fermi surface of two dimensional graphene are responsible for its unique electronic behavior. One can ask whether any three dimensional materials support similar pseudorelativistic physics in their bulk electronic spectra. This possibility has been investigated theoretically and is now supported by two successful experimental demonstrations reported during the last year. In this talk, I will summarize the various ways in which Dirac semimetals can be realized in three dimensions with primary focus on a specific theory developed on the basis of representations of crystal spacegroups. A three dimensional Dirac (Weyl) semimetal can appear in the presence (absence) of inversion symmetry by tuning parameters to the phase boundary separating a bulk insulating and a topological insulating phase. More generally, we find that specific rules governing crystal symmetry representations of electrons with spin lead to robust Dirac points at high symmetry points in the Brillouin zone. Combining these rules with microscopic considerations identifies six candidate Dirac semimetals. Another method towards engineering Dirac semimetals involves combining crystal symmetry and band inversion. Several candidate materials have been proposed utilizing this mechanism and one of the candidates has been successfully demonstrated as a Dirac semimetal in two independent experiments. Work carried out in collaboration with: Julia A. Steinberg, Steve M. Young, J.C.Y. Teo, C.L. Kane, E.J. Mele and Andrew M. Rappe.

  10. Two-dimensional and three-dimensional dynamic imaging of live biofilms in a microchannel by time-of-flight secondary ion mass spectrometry.

    PubMed

    Hua, Xin; Marshall, Matthew J; Xiong, Yijia; Ma, Xiang; Zhou, Yufan; Tucker, Abigail E; Zhu, Zihua; Liu, Songqin; Yu, Xiao-Ying

    2015-05-01

    A vacuum compatible microfluidic reactor, SALVI (System for Analysis at the Liquid Vacuum Interface), was employed for in situ chemical imaging of live biofilms using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Depth profiling by sputtering materials in sequential layers resulted in live biofilm spatial chemical mapping. Two-dimensional (2D) images were reconstructed to report the first three-dimensional images of hydrated biofilm elucidating spatial and chemical heterogeneity. 2D image principal component analysis was conducted among biofilms at different locations in the microchannel. Our approach directly visualized spatial and chemical heterogeneity within the living biofilm by dynamic liquid ToF-SIMS. PMID:26015837

  11. Two-dimensional and three-dimensional dynamic imaging of live biofilms in a microchannel by time-of-flight secondary ion mass spectrometry

    PubMed Central

    Hua, Xin; Marshall, Matthew J.; Xiong, Yijia; Ma, Xiang; Zhou, Yufan; Tucker, Abigail E.; Zhu, Zihua; Liu, Songqin

    2015-01-01

    A vacuum compatible microfluidic reactor, SALVI (System for Analysis at the Liquid Vacuum Interface), was employed for in situ chemical imaging of live biofilms using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Depth profiling by sputtering materials in sequential layers resulted in live biofilm spatial chemical mapping. Two-dimensional (2D) images were reconstructed to report the first three-dimensional images of hydrated biofilm elucidating spatial and chemical heterogeneity. 2D image principal component analysis was conducted among biofilms at different locations in the microchannel. Our approach directly visualized spatial and chemical heterogeneity within the living biofilm by dynamic liquid ToF-SIMS. PMID:26015837

  12. Three Dimensional (3D) Printing: A Straightforward, User-Friendly Protocol to Convert Virtual Chemical Models to Real-Life Objects

    ERIC Educational Resources Information Center

    Rossi, Sergio; Benaglia, Maurizio; Brenna, Davide; Porta, Riccardo; Orlandi, Manuel

    2015-01-01

    A simple procedure to convert protein data bank files (.pdb) into a stereolithography file (.stl) using VMD software (Virtual Molecular Dynamic) is reported. This tutorial allows generating, with a very simple protocol, three-dimensional customized structures that can be printed by a low-cost 3D-printer, and used for teaching chemical education…

  13. Real-time radiography

    SciTech Connect

    Bossi, R.H.; Oien, C.T.

    1981-02-26

    Real-time radiography is used for imaging both dynamic events and static objects. Fluorescent screens play an important role in converting radiation to light, which is then observed directly or intensified and detected. The radiographic parameters for real-time radiography are similar to conventional film radiography with special emphasis on statistics and magnification. Direct-viewing fluoroscopy uses the human eye as a detector of fluorescent screen light or the light from an intensifier. Remote-viewing systems replace the human observer with a television camera. The remote-viewing systems have many advantages over the direct-viewing conditions such as safety, image enhancement, and the capability to produce permanent records. This report reviews real-time imaging system parameters and components.

  14. Real-Time Simulation

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Coryphaeus Software, founded in 1989 by former NASA electronic engineer Steve Lakowske, creates real-time 3D software. Designer's Workbench, the company flagship product, is a modeling and simulation tool for the development of both static and dynamic 3D databases. Other products soon followed. Activation, specifically designed for game developers, allows developers to play and test the 3D games before they commit to a target platform. Game publishers can shorten development time and prove the "playability" of the title, maximizing their chances of introducing a smash hit. Another product, EasyT, lets users create massive, realistic representation of Earth terrains that can be viewed and traversed in real time. Finally, EasyScene software control the actions among interactive objects within a virtual world. Coryphaeus products are used on Silican Graphics workstation and supercomputers to simulate real-world performance in synthetic environments. Customers include aerospace, aviation, architectural and engineering firms, game developers, and the entertainment industry.

  15. Three-dimensional, two-species magnetohydrodynamic studies of the early time behaviors of the Combined Release and Radiation Effects Satellite G2 barium release

    SciTech Connect

    Xie, Lianghai Li, Lei; Wang, Jingdong; Zhang, Yiteng

    2014-04-15

    We present a three-dimensional, two-species (Ba{sup +} and H{sup +}) MHD model to study the early time behaviors of a barium release at about 1 R{sub E} like Combined Release and Radiation Effects Satellite G2, with emphasis placed on the three-dimensional evolution of the barium cloud and its effects on the ambient plasma environment. We find that the perturbations caused by the cloud are the combined results of the initial injection, the radial expansion, and the diamagnetic effect and propagate as fast MHD waves in the magnetosphere. In return, the transverse expansion and the cross-B motion of barium ions are constrained by the magnetic force, which lead to a field-aligned striation of ions and the decoupling of these ions from the neutrals. Our simulation shows the formation and collapse of the diamagnetic cavity in the barium cloud. The estimated time scale for the cavity evolution might be much shorter if photoionization time scale and field aligned expansion of barium ions are considered. In addition, our two species MHD simulation also finds the snowplow effect resulting from the momentum coupling between barium ions and background H{sup +}, which creates density hole and bumps in the background H{sup +} when barium ions expanding along the magnetic field lines.

  16. Data Visualization in Physics II: VRML and Java for three-dimensional imaging and fully three-dimensional movies

    NASA Astrophysics Data System (ADS)

    Fenton, Flavio H.; Evans, Steven J.; Hastings, Harold M.; Cherry, Elizabeth M.

    2006-03-01

    Presentation and analysis of large three-dimensional data sets is in general hard to do using only two-dimensional figures and plots. In this talk, we will demonstrate techniques for illustrating static and dynamic three-dimensional objects and data using Virtual Reality Modeling Language (VRML) as well as Java. The advantage of these two languages is that they are platform-independent, which allows for easy sharing of data and visualizations. In addition, manipulation of data is relatively easy as rotation, translation and zooming can be done in real- time for static objects as well as for data and objects that vary and deform in time. Examples of fully three-dimensional movies will be shown, including dendritic growth and propagation of electrical waves in cardiac tissue. In addition, we will show how to include VRML and Java viewers in PowerPoint for easy presentation of results in classes and seminars.

  17. Three dimensional interactive display

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2005-01-01

    A three-dimensional (3-D) interactive display and method of forming the same, includes a transparent capaciflector (TC) camera formed on a transparent shield layer on the screen surface. A first dielectric layer is formed on the shield layer. A first wire layer is formed on the first dielectric layer. A second dielectric layer is formed on the first wire layer. A second wire layer is formed on the second dielectric layer. Wires on the first wire layer and second wire layer are grouped into groups of parallel wires with a turnaround at one end of each group and a sensor pad at the opposite end. An operational amplifier is connected to each of the sensor pads and the shield pad biases the pads and receives a signal from connected sensor pads in response to intrusion of a probe. The signal is proportional to probe location with respect to the monitor screen.

  18. Deriving Sensitivity Kernels of Coda-Wave Travel Times to Velocity Changes Based on the Three-Dimensional Single Isotropic Scattering Model

    NASA Astrophysics Data System (ADS)

    Nakahara, Hisashi; Emoto, Kentaro

    2016-08-01

    Recently, coda-wave interferometry has been used to monitor temporal changes in subsurface structures. Seismic velocity changes have been detected by coda-wave interferometry in association with large earthquakes and volcanic eruptions. To constrain the spatial extent of the velocity changes, spatial homogeneity is often assumed. However, it is important to locate the region of the velocity changes correctly to understand physical mechanisms causing them. In this paper, we are concerned with the sensitivity kernels relating travel times of coda waves to velocity changes. In previous studies, sensitivity kernels have been formulated for two-dimensional single scattering and multiple scattering, three-dimensional multiple scattering, and diffusion. In this paper, we formulate and derive analytical expressions of the sensitivity kernels for three-dimensional single-scattering case. These sensitivity kernels show two peaks at both source and receiver locations, which is similar to the previous studies using different scattering models. The two peaks are more pronounced for later lapse time. We validate our formulation by comparing it with finite-difference simulations of acoustic wave propagation. Our formulation enables us to evaluate the sensitivity kernels analytically, which is particularly useful for the analysis of body waves from deeper earthquakes.

  19. Three Dimensional Finite Difference Time Domain Modeling of Ground Penetrating Radar with an Efficient and Robust Algorithm to Define and Predict Hydrologic Properties in the Subsurface

    NASA Astrophysics Data System (ADS)

    Eyuboglu, S.; Daniels, J. J.; Pyke, K.

    2005-12-01

    Ground Penetrating Radar (GPR) is a commonly used non-invasive tool to characterize the physical properties of the subsurface. The translation of the physical measurements to geologic and hydrogeologic conditions is the culmination of many geophysical investigations. Numerical modeling increases the applicability of GPR in the geophysics area when applied parallel to the GPR data, allowing to understand the effects of complex electromagnetic phenomena by defining and solving problems, as well as predicting the performance of radar in a complex heterogeneous environment. Finite difference time domain (FDTD) has been widely used for numerical modeling of GPR, but most of the previous algorithms are limited in their ability to model the electrical conductivity and permittivity. In this research, a highly efficient robust algorithm was developed to enhance the effectiveness of the FDTD forward modeling in surroundings characterized by an arbitrary distribution of all electrical properties in three dimensional space. The modeling algorithm was developed for a heterogeneous half-space medium to facilitate statistical modeling of complex distributions of hydrologic properties in the subsurface. The results produced by the simulation reveal high accuracy using the robust algorithm to optimize three dimensional FDTD forward modeling of GPR responses in heterogeneous surroundings.

  20. Three-dimensional change in the cervical spine in a cross-legged sitting position after a time lapse

    PubMed Central

    Jung, Seo-young; Choi, Bo-ram

    2016-01-01

    [Purpose] The purpose of this study was to investigate the kinematic changes of the cervical spine during cross-legged sitting. [Subjects and Methods] In total, 19 healthy participants were recruited from among healthy students of Silla University. Each participant sat cross-legged with the right leg over the left and gazed at a target presented at 45° below the horizontal line of sight or at an object placed directly ahead, at 90° relative to horizontal for 10 minutes. [Results] With the 45° downward gaze, there was no significant difference in cervical angle between the 0–5-min and 5–10-min time periods. However, the angle in the sagittal plane increased with time, while the frontal and transverse plane angles decreased. With the 90° forward gaze, there was no significant difference in cervical angle between the 0–5-min and 5–10-min time periods. However, the frontal plane angle increased as time elapsed, while the sagittal and transverse plane angles increased between 0 and 5 min and decreased between 5 and 10 min. [Conclusion] Our results suggest that prolonged cross-legged sitting could produce malalignment of the cervical spine in three planes of motion. PMID:27313392

  1. Three-dimensional change in the cervical spine in a cross-legged sitting position after a time lapse.

    PubMed

    Jung, Seo-Young; Choi, Bo-Ram

    2016-05-01

    [Purpose] The purpose of this study was to investigate the kinematic changes of the cervical spine during cross-legged sitting. [Subjects and Methods] In total, 19 healthy participants were recruited from among healthy students of Silla University. Each participant sat cross-legged with the right leg over the left and gazed at a target presented at 45° below the horizontal line of sight or at an object placed directly ahead, at 90° relative to horizontal for 10 minutes. [Results] With the 45° downward gaze, there was no significant difference in cervical angle between the 0-5-min and 5-10-min time periods. However, the angle in the sagittal plane increased with time, while the frontal and transverse plane angles decreased. With the 90° forward gaze, there was no significant difference in cervical angle between the 0-5-min and 5-10-min time periods. However, the frontal plane angle increased as time elapsed, while the sagittal and transverse plane angles increased between 0 and 5 min and decreased between 5 and 10 min. [Conclusion] Our results suggest that prolonged cross-legged sitting could produce malalignment of the cervical spine in three planes of motion. PMID:27313392

  2. Three-dimensional time and frequency-domain theory of femtosecond x-ray pulse generation through Thomson Scattering

    SciTech Connect

    Brown, W J; Hartemann, F V

    2004-01-27

    The generation of high intensity, ultra-short x-ray pulses enables exciting new experimental capabilities, such as femtosecond pump-probe experiments used to temporally resolve material structural dynamics on atomic time scales. Thomson backscattering of a high intensity laser pulse with a bright relativistic electron bunch is a promising method for producing such high brightness x-ray pulses in the 10-100 keV range within a compact facility. While a variety of methods for producing sub-picosecond x-ray bursts by Thomson scattering exist, including compression of the electron bunch to sub-picosecond bunch lengths and/or colliding a sub-picosecond laser pulse in a side-on geometry to minimize the interaction time, a promising alternative approach to achieving this goal while maintaining ultra-high brightness is the production of a time correlated (or chirped) x-ray pulse in conjunction with pulse slicing or compression. We present the results of a complete analysis of this process using a recently developed 3-D time and frequency-domain code for analyzing the spatial, temporal, and spectral properties an x-ray beam produced by relativistic Thomson scattering. Based on the relativistic differential cross section, this code has the capability to calculate time and space dependent spectra of the x-ray photons produced from linear Thomson scattering for both bandwidth-limited and chirped incident laser pulses. Spectral broadening of the scattered x-ray pulse resulting from the incident laser bandwidth, laser focus, and the transverse and longitudinal phase space of the electron beam were examined. Simulations of chirped x-ray pulse production using both a chirped electron beam and a chirped laser pulse are presented. Required electron beam and laser parameters are summarized by investigating the effects of beam emittance, energy spread, and laser bandwidth on the scattered x-ray spectrum. It is shown that sufficient temporal correlation in the scattered x-ray spectrum

  3. Three-dimensional kinematics of the scapula and trunk, and associated scapular muscle timing in individuals with stroke.

    PubMed

    De Baets, Liesbet; Van Deun, Sara; Monari, Davide; Jaspers, Ellen

    2016-08-01

    Poor scapulothoracic control is a risk for developing shoulder pathology, but has received little attention so far in individuals with stroke (IwS). Trunk and scapular kinematics and surface muscle activity were measured in 15 healthy controls and 18 IwS during a low and high forward flexion (FF). Group-differences in trunk and scapular kinematics were assessed during low and high FF using a t-test (independent samples). Differences in muscle onset and offset time relative to movement start (both FF tasks) were determined using a mixed model taking into account the different groups and muscles. Recruitment patterns per group and task were described based on significant differences between muscles. In IwS, earlier lower trapezius and late infraspinatus offset were found during low FF, as well as a later onset and earlier offset of serratus anterior. For low FF, significantly more trunk axial rotation was found in IwS during both elevation and lowering. During high FF, IwS showed significantly less scapular posterior tilt during elevation and more scapular lateral rotation during lowering. IwS demonstrated adaptive muscle timing with earlier initiation and late inactivation of lower trapezius and infraspinatus, possibly to compensate for a late activation and early deactivation of the serratus anterior and to establish as such the correct pattern of scapulothoracic movement. PMID:27155342

  4. Three-dimensional, Time-Resolved, Intrafraction Motion Monitoring Throughout Stereotactic Liver Radiation Therapy on a Conventional Linear Accelerator

    SciTech Connect

    Worm, Esben S.; Høyer, Morten; Fledelius, Walter; Poulsen, Per R.

    2013-05-01

    Purpose: To investigate the time-resolved 3-dimensional (3D) internal motion throughout stereotactic body radiation therapy (SBRT) of tumors in the liver using standard x-ray imagers of a conventional linear accelerator. Methods and Materials: Ten patients with implanted gold markers received 11 treatment courses of 3-fraction SBRT in a stereotactic body-frame on a conventional linear accelerator. Two pretreatment and 1 posttreatment cone-beam computed tomography (CBCT) scans were acquired during each fraction. The CBCT projection images were used to estimate the internal 3D marker motion during CBCT acquisition with 11-Hz resolution by a monoscopic probability-based method. Throughout the treatment delivery by conformal or volumetric modulated arc fields, simultaneous MV portal imaging (8 Hz) and orthogonal kV imaging (5 Hz) were applied to determine the 3D marker motion using either MV/kV triangulation or the monoscopic method when marker segmentation was unachievable in either MV or kV images. The accuracy of monoscopic motion estimation was quantified by also applying monoscopic estimation as a test for all treatments during which MV/kV triangulation was possible. Results: Root-mean-square deviations between monoscopic estimations and triangulations were less than 1.0 mm. The mean 3D intrafraction and intrafield motion ranges during liver SBRT were 17.6 mm (range, 5.6-39.5 mm) and 11.3 mm (2.1-35.5mm), respectively. The risk of large intrafraction baseline shifts correlated with intrafield respiratory motion range. The mean 3D intrafractional marker displacement relative to the first CBCT was 3.4 mm (range, 0.7-14.5 mm). The 3D displacements exceeded 8.8 mm 10% of the time. Conclusions: Highly detailed time-resolved internal 3D motion was determined throughout liver SBRT using standard imaging equipment. Considerable intrafraction motion was observed. The demonstrated methods provide a widely available approach for motion monitoring that, combined with motion

  5. A three-dimensional simulation of transition and early turbulence in a time-developing mixing layer

    NASA Technical Reports Server (NTRS)

    Cain, A. B.; Reynolds, W. C.; Ferziger, J. H.

    1981-01-01

    The physics of the transition and early turbulence regimes in the time developing mixing layer was investigated. The sensitivity of the mixing layer to the disturbance field of the initial condition is considered. The growth of the momentum thickness, the mean velocity profile, the turbulence kinetic energy, the Reynolds stresses, the anisotropy tensor, and particle track pictures of computations are all examined in an effort to better understand the physics of these regimes. The amplitude, spectrum shape, and random phases of the initial disturbance field were varied. A scheme of generating discrete orthogonal function expansions on some nonuniform grids was developed. All cases address the early or near field of the mixing layer. The most significant result shows that the secondary instability of the mixing layer is produced by spanwise variations in the straining field of the primary vortex structures.

  6. Three-dimensional image signals: processing methods

    NASA Astrophysics Data System (ADS)

    Schiopu, Paul; Manea, Adrian; Craciun, Anca-Ileana; Craciun, Alexandru

    2010-11-01

    Over the years extensive studies have been carried out to apply coherent optics methods in real-time processing, communications and transmission image. This is especially true when a large amount of information needs to be processed, e.g., in high-resolution imaging. The recent progress in data-processing networks and communication systems has considerably increased the capacity of information exchange. We describe the results of literature investigation research of processing methods for the signals of the three-dimensional images. All commercially available 3D technologies today are based on stereoscopic viewing. 3D technology was once the exclusive domain of skilled computer-graphics developers with high-end machines and software. The images capture from the advanced 3D digital camera can be displayed onto screen of the 3D digital viewer with/ without special glasses. For this is needed considerable processing power and memory to create and render the complex mix of colors, textures, and virtual lighting and perspective necessary to make figures appear three-dimensional. Also, using a standard digital camera and a technique called phase-shift interferometry we can capture "digital holograms." These are holograms that can be stored on computer and transmitted over conventional networks. We present some research methods to process "digital holograms" for the Internet transmission and results.

  7. Parallel Monte Carlo transport modeling in the context of a time-dependent, three-dimensional multi-physics code

    SciTech Connect

    Procassini, R.J.

    1997-12-31

    The fine-scale, multi-space resolution that is envisioned for accurate simulations of complex weapons systems in three spatial dimensions implies flop-rate and memory-storage requirements that will only be obtained in the near future through the use of parallel computational techniques. Since the Monte Carlo transport models in these simulations usually stress both of these computational resources, they are prime candidates for parallelization. The MONACO Monte Carlo transport package, which is currently under development at LLNL, will utilize two types of parallelism within the context of a multi-physics design code: decomposition of the spatial domain across processors (spatial parallelism) and distribution of particles in a given spatial subdomain across additional processors (particle parallelism). This implementation of the package will utilize explicit data communication between domains (message passing). Such a parallel implementation of a Monte Carlo transport model will result in non-deterministic communication patterns. The communication of particles between subdomains during a Monte Carlo time step may require a significant level of effort to achieve a high parallel efficiency.

  8. Real-Time PCR

    NASA Astrophysics Data System (ADS)

    Evrard, A.; Boulle, N.; Lutfalla, G. S.

    Over the past few years there has been a considerable development of DNA amplification by polymerase chain reaction (PCR), and real-time PCR has now superseded conventional PCR techniques in many areas, e.g., the quantification of nucleic acids and genotyping. This new approach is based on the detection and quantification of a fluorescent signal proportional to the amount of amplicons generated by PCR. Real-time detection is achieved by coupling a thermocycler with a fluorimeter. This chapter discusses the general principles of quantitative real-time PCR, the different steps involved in implementing the technique, and some examples of applications in medicine. The polymerase chain reaction (PCR) provides a way of obtaining a large number of copies of a double-stranded DNA fragment of known sequence. This DNA amplification technique, developed in 1985 by K. Mullis (Cetus Corporation), saw a spectacular development over the space of a few years, revolutionising the methods used up to then in molecular biology. Indeed, PCR has many applications, such as the detection of small amounts of DNA, cloning, and quantitative analysis (assaying), each of which will be discussed further below.

  9. Three-dimensional accommodation analysis of the Triassic in the Paris Basin: a new approach in unravelling the basin evolution with time

    NASA Astrophysics Data System (ADS)

    Goggin, Valerie; Jacquin, Thierry; Gaulier, Jean Michel

    1997-12-01

    The mechanisms governing the development of the Paris Basin throughout the Triassic are regarded as being the result of superimposed and successive processes. In this study, the Triassic succession of the Paris Basin was re-interpreted in a sequence stratigraphic context, using essentially wireline log data. From this, a series of isopach maps, lithofacies maps and palaeobathymetric maps was produced for each sequence. Three-dimensional accommodation analysis was then carried out sequence by sequence, over the entire basin to produce a precise, detailed accommodation history for the entire Triassic succession. Previous studies have proposed that the Triassic was deposited during a rift period in a transtensional stress regime, with the formation of a trough superposed onto three fault systems derived from the Variscan structural framework. In this study, Scythian to Ladinian sediments (Buntsandstein and Muschelkalk) record the stress regime that prevailed over much of NW Europe. The basin architecture at this time is in continuity with the neighbouring Germanic Basin. Our three-dimensional accommodation modelling shows that the stress regime changed during the Carnian and the late Norian (Keuper). The Carnian events are marked by (1) the creation of a large depocentre infilled with halite, and (2) a northwest migration of this depocentre during the mid-late Carnian along with deposition of the Grès-à-Roseaux, an extensive fluvial deposit. This documents renewed strike-slip movement along the Bray fault. The Norian events involved major tectonic uplift on the basin margins, producting fan delta progradation into the basin. Rotation of the previous depocentre axis occurs on the downthrown side of the Bray fault. This may be viewed as a consequence of sinistral strike-slip displacement along the Bray fault, forming a local transpressive stress regime. The following Liassic cycle commenced with the Rhaetic sequences and illustrates a complete change in the stress

  10. Enhancing Biological Analyses with Three Dimensional Field Asymmetric Ion Mobility, Low Field Drift Time Ion Mobility and Mass Spectrometry (µFAIMS/IMS-MS) Separations

    SciTech Connect

    Zhang, Xing; Ibrahim, Yehia M.; Chen, Tsung-Chi; Kyle, Jennifer E.; Norheim, Randolph V.; Monroe, Matthew E.; Smith, Richard D.; Baker, Erin Shammel

    2015-06-30

    We report the first evaluation of a platform coupling a high speed field asymmetric ion mobility spectrometry microchip (µFAIMS) with drift tube ion mobility and mass spectrometry (IMS-MS). The µFAIMS/IMS-MS platform was used to analyze biological samples and simultaneously acquire multidimensional information of detected features from the measured FAIMS compensation fields and IMS drift times, while also obtaining accurate ion masses. These separations thereby increase the overall separation power, resulting increased information content, and provide more complete characterization of more complex samples. The separation conditions were optimized for sensitivity and resolving power by the selection of gas compositions and pressures in the FAIMS and IMS separation stages. The resulting performance provided three dimensional separations, benefitting both broad complex mixture studies and targeted analyses by e.g. improving isomeric separations and allowing detection of species obscured by “chemical noise” and other interfering peaks.

  11. A staggered space-time discontinuous Galerkin method for the three-dimensional incompressible Navier-Stokes equations on unstructured tetrahedral meshes

    NASA Astrophysics Data System (ADS)

    Tavelli, Maurizio; Dumbser, Michael

    2016-08-01

    In this paper we propose a novel arbitrary high order accurate semi-implicit space-time discontinuous Galerkin method for the solution of the three-dimensional incompressible Navier-Stokes equations on staggered unstructured curved tetrahedral meshes. As is typical for space-time DG schemes, the discrete solution is represented in terms of space-time basis functions. This allows to achieve very high order of accuracy also in time, which is not easy to obtain for the incompressible Navier-Stokes equations. Similarly to staggered finite difference schemes, in our approach the discrete pressure is defined on the primary tetrahedral grid, while the discrete velocity is defined on a face-based staggered dual grid. While staggered meshes are state of the art in classical finite difference schemes for the incompressible Navier-Stokes equations, their use in high order DG schemes is still quite rare. A very simple and efficient Picard iteration is used in order to derive a space-time pressure correction algorithm that achieves also high order of accuracy in time and that avoids the direct solution of global nonlinear systems. Formal substitution of the discrete momentum equation on the dual grid into the discrete continuity equation on the primary grid yields a very sparse five-point block system for the scalar pressure, which is conveniently solved with a matrix-free GMRES algorithm. From numerical experiments we find that the linear system seems to be reasonably well conditioned, since all simulations shown in this paper could be run without the use of any preconditioner, even up to very high polynomial degrees. For a piecewise constant polynomial approximation in time and if pressure boundary conditions are specified at least in one point, the resulting system is, in addition, symmetric and positive definite. This allows us to use even faster iterative solvers, like the conjugate gradient method. The flexibility and accuracy of high order space-time DG methods on curved

  12. Three dimensional Dirac semimetals

    NASA Astrophysics Data System (ADS)

    Zaheer, Saad

    We extend the physics of graphene to three dimensional systems by showing that Dirac points can exist on the Fermi surface of realistic materials in three dimensions. Many of the exotic electronic properties of graphene can be ascribed to the pseudorelativistic behavior of its charge carriers due to two dimensional Dirac points on the Fermi surface. We show that certain nonsymmorphic spacegroups exhibit Dirac points among the irreducible representations of the appropriate little group at high symmetry points on the surface of the Brillouin zone. We provide a list of all Brillouin zone momenta in the 230 spacegroups that can host Dirac points. We describe microscopic considerations necessary to design materials in one of the candidate spacegroups such that the Dirac point appears at the Fermi energy without any additional non-Dirac-like Fermi pockets. We use density functional theory based methods to propose six new Dirac semimetals: BiO 2 and SbO2 in the beta-cristobalite lattice (spacegroup 227), and BiCaSiO4, BiMgSiO4, BiAlInO 4, and BiZnSiO4 in the distorted spinels lattice (spacegroup 74). Additionally we derive effective Dirac Hamiltonians given group representative operators as well as tight binding models incorporating spin-orbit coupling. Finally we study the Fermi surface of zincblende (spacegroup 216) HgTe which is effectively point-like at Gamma in the Brillouin zone and exhibits accidental degeneracies along a threefold rotation axis. Whereas compressive strain gaps the band structure into a topological insulator, tensile strain shifts the accidental degeneracies away from Gamma and enlarges the Fermi surface. States on the Fermi surface exhibit nontrivial spin texture marked by winding of spins around the threefold rotation axis and by spin vortices indicating a change in the winding number. This is confirmed by microscopic calculations performed in tensile strained HgTe and Hg0.5Zn 0.5 Te as well as k.p theory. We conclude with a summary of recent

  13. Real time Faraday spectrometer

    DOEpatents

    Smith, Jr., Tommy E.; Struve, Kenneth W.; Colella, Nicholas J.

    1991-01-01

    This invention uses a dipole magnet to bend the path of a charged particle beam. As the deflected particles exit the magnet, they are spatially dispersed in the bend-plane of the magnet according to their respective momenta and pass to a plurality of chambers having Faraday probes positioned therein. Both the current and energy distribution of the particles is then determined by the non-intersecting Faraday probes located along the chambers. The Faraday probes are magnetically isolated from each other by thin metal walls of the chambers, effectively providing real time current-versus-energy particle measurements.

  14. Three-dimensional inversion of regional P and S arrival times in the East Aleutians and sources of subduction zone gravity highs

    NASA Astrophysics Data System (ADS)

    Abers, Geoffrey A.

    1994-03-01

    Free-air gravity highs over forearcs represent a large fraction of the power in the Earth's anomalous field, yet their origin remains uncertain. Seismic velocities, as indicators of density, are estimated here as a means to compare the relative importance of upper plate sources for the gravity high with sources in the downgoing plate. P and S arrival times for local earthquakes, recorded by a seismic network in the eastern Aleutians, are inverted for three-dimensional velocity structure between the volcanic arc and the downgoing plate. A three-dimensional ray tracing scheme is used to invert the 7974 P and 6764 S arrivals for seismic velocities and hypocenters of 635 events. One-dimensional inversions show that station P residuals are systematically 0.25-0.5 s positive at stations 0-30 km north of the Aleutian volcanic arc, indicating slow material, while residuals at stations 10-30 km south of the arc are 0.1-0.25 s negative. Both features are explained in three-dimensional inversions by velocity variations at depths less than 25-35 km. Tests using a one-dimensional or a two-dimensional slab starting model show that below 100 km depth, velocities are poorly determined and trade off almost completely with hypocenters for earthquakes at these depths. The locations of forearc velocity highs, in the crust of the upper plate, correspond to the location of the gravity high between the trench and volcanic arc. Free-air anomalies, calculated from the three-dimensional velocity inversion result, match observed gravity for a linear density-velocity relationship between 0.1 and 0.3 (Mg m-3)/(km s-1), when a 50-km-thick slab is included with a density of 0.055±0.005 Mg m-3. Values outside these ranges do not match the observed gravity. The slab alone contributes one third to one half of the total 75-150 mGal amplitude of the gravity high but predicts a high that is much broader than is observed. The inclusion of upper-plate velocity anomalies predicts the correct width of

  15. Three-Dimensional Visualization of Particle Tracks.

    ERIC Educational Resources Information Center

    Julian, Glenn M.

    1993-01-01

    Suggests ways to bring home to the introductory physics student some of the excitement of recent discoveries in particle physics. Describes particle detectors and encourages the use of the Standard Model along with real images of particle tracks to determine three-dimensional views of tracks. (MVL)

  16. On a class of unsteady three-dimensional Navier Stokes solutions relevant to rotating disc flows: Threshold amplitudes and finite time singularities

    NASA Technical Reports Server (NTRS)

    Hall, Philip; Balakumar, P.

    1990-01-01

    A class of exact steady and unsteady solutions of the Navier Stokes equations in cylindrical polar coordinates is given. The flows correspond to the motion induced by an infinite disc rotating with constant angular velocity about the z-axis in a fluid occupying a semi-infinite region which, at large distances from the disc, has velocity field proportional to (x,-y,O) with respect to a Cartesian coordinate system. It is shown that when the rate of rotation is large, Karman's exact solution for a disc rotating in an otherwise motionless fluid is recovered. In the limit of zero rotation rate a particular form of Howarth's exact solution for three-dimensional stagnation point flow is obtained. The unsteady form of the partial differential system describing this class of flow may be generalized to time-periodic equilibrium flows. In addition the unsteady equations are shown to describe a strongly nonlinear instability of Karman's rotating disc flow. It is shown that sufficiently large perturbations lead to a finite time breakdown of that flow whilst smaller disturbances decay to zero. If the stagnation point flow at infinity is sufficiently strong, the steady basic states become linearly unstable. In fact there is then a continuous spectrum of unstable eigenvalues of the stability equations but, if the initial value problem is considered, it is found that, at large values of time, the continuous spectrum leads to a velocity field growing exponentially in time with an amplitude decaying algebraically in time.

  17. Real time automated inspection

    DOEpatents

    Fant, Karl M.; Fundakowski, Richard A.; Levitt, Tod S.; Overland, John E.; Suresh, Bindinganavle R.; Ulrich, Franz W.

    1985-01-01

    A method and apparatus relating to the real time automatic detection and classification of characteristic type surface imperfections occurring on the surfaces of material of interest such as moving hot metal slabs produced by a continuous steel caster. A data camera transversely scans continuous lines of such a surface to sense light intensities of scanned pixels and generates corresponding voltage values. The voltage values are converted to corresponding digital values to form a digital image of the surface which is subsequently processed to form an edge-enhanced image having scan lines characterized by intervals corresponding to the edges of the image. The edge-enhanced image is thresholded to segment out the edges and objects formed by the edges are segmented out by interval matching and bin tracking. Features of the objects are derived and such features are utilized to classify the objects into characteristic type surface imperfections.

  18. Real time automated inspection

    DOEpatents

    Fant, K.M.; Fundakowski, R.A.; Levitt, T.S.; Overland, J.E.; Suresh, B.R.; Ulrich, F.W.

    1985-05-21

    A method and apparatus are described relating to the real time automatic detection and classification of characteristic type surface imperfections occurring on the surfaces of material of interest such as moving hot metal slabs produced by a continuous steel caster. A data camera transversely scans continuous lines of such a surface to sense light intensities of scanned pixels and generates corresponding voltage values. The voltage values are converted to corresponding digital values to form a digital image of the surface which is subsequently processed to form an edge-enhanced image having scan lines characterized by intervals corresponding to the edges of the image. The edge-enhanced image is thresholded to segment out the edges and objects formed by the edges by interval matching and bin tracking. Features of the objects are derived and such features are utilized to classify the objects into characteristic type surface imperfections. 43 figs.

  19. Detection of Residual Brain Arteriovenous Malformations after Radiosurgery: Diagnostic Accuracy of Contrast-Enhanced Three-Dimensional Time of Flight MR Angiography at 3.0 Tesla

    PubMed Central

    Lee, Kyoung Eun; Choi, Jin Woo; Choi, Byung Se; Lee, Deok Hee; Kim, Sang Joon; Kwon, Do Hoon

    2009-01-01

    Objective Although three-dimensional time-of-flight magnetic resonance angiography (3D TOF-MRA) is used frequently as a follow-up tool to assess the response of arteriovenous malformations (AVMs) after radiosurgery, the diagnostic accuracy of 3D TOF-MRA is not well known. We evaluated the diagnostic accuracy of contrast-enhanced 3D TOF-MRA at 3.0 Tesla for the detection of residual AVMs. Materials and Methods This study included 32 AVMs from 32 patients who had been treated with radiosurgery (males/females: 21/11; average patient age, 33.1 years). The time interval between radiosurgery and MRA was an average of 35.3 months (range, 12-88 months). Three-dimensional TOF-MRA was obtained at a magnetic field strength of 3.0 Tesla after infusion of contrast media, with a measured voxel size of 0.40 × 0.80 × 1.4 (0.45) mm3 and a reconstructed voxel size of 0.27 × 0.27 × 0.70 (0.05) mm3 after zero-filling. X-ray angiography was performed as the reference of standard within six months after MRA (an average of two months). To determine the presence of a residual AVM, the source images of 3D TOF-MRA were independently reviewed, focusing on the presence of abnormally hyperintense fine tangled or tubular structures with continuity as seen on consecutive slices by two observers blinded to the X-ray angiography results. Results A residual AVM was identified in 10 patients (10 of 32, 31%) on X-ray angiography. The inter-observer agreement for MRA was excellent (κ= 0.813). For the detection of a residual AVM after radiosurgery as determined by observer 1 and observer 2, the source images of MRA had an overall sensitivity of 100%/90% (10 of 10, 9 of 10), specificity of 68%/68% (15 of 22, 15 of 22), positive predictive value of 59%/56% (10 of 17, 9 of 16), negative predictive value of 100%/94% (15 of 15, 15 of 16) and diagnostic accuracy of 78%/75% (25 of 32, 24 of 32), respectively. Conclusion The sensitivity of contrast-enhanced 3D TOF-MRA at 3.0 Tesla is high but the

  20. Using the Bi-Orthogonal Decomposition framework to compute the three dimensional Empirical Orthogonal Functions of stratospheric planetary waves from time correlation matrices

    NASA Astrophysics Data System (ADS)

    Rolland, Joran; Domeisen, Daniela I. V.

    2016-04-01

    Many geophysical waves in the atmosphere or in the ocean have a three dimensional structure and contain a range of scales. This is for instance the case of planetary waves in the stratosphere connected to baroclinic eddies in the troposphere [1]. In the study of such waves from reanalysis data or output of numerical simulations, Empirical Orthogonal Functions (EOF) obtained as a Proper Orthogonal Decomposition of the data sets have been of great help. However, most of these computations rely on the diagonalisation of space correlation matrices: this means that the considered data set can only have a limited number of gridpoints. The main consequence is that such analyses are often only performed in planes (as function of height and latitude, or longitude and latitude for instance), which makes the educing of the three dimensional structure of the wave quite difficult. In the case of the afore mentionned waves, the matter of the longitudinal dependence or the proper correlation between modes through the tropopause is an open question. An elegant manner to circumvent this problem is to consider the output of the Orthogonal Decomposition as a whole. Indeed, it has been shown that the normalised time series of the amplitude of each EOF, far from just being decorrelated from one another, are actually another set of orthogonal functions. These can actually be computed through the diagonlisation of the time correlation matrix of the data set, just like the EOF were the result of the diagonalisation of the space correlation matrix. The signal is then fully decomposed in the framework of the Bi-Orthogonal Decomposition as the sum of the nth explained variance, time the nth eigenmode of the time correlation times the nth eigenmode of the spacial correlations [2,3]. A practical consequence of this result is that the EOF can be reconstructed from the projection of the dataset onto the eigenmodes of the time correlation matrix in the so-called snapshot method [4]. This is very

  1. Using the Bi-Orthogonal Decomposition framework to compute the three dimensional Empirical Orthogonal Functions of stratospheric planetary waves from time correlation matrices

    NASA Astrophysics Data System (ADS)

    Rolland, Joran; Domeisen, Daniela I. V.

    2016-04-01

    Many geophysical waves in the atmosphere or in the ocean have a three dimensional structure and contain a range of scales. This is for instance the case of planetary waves in the stratosphere connected to baroclinic eddies in the troposphere [1]. In the study of such waves from reanalysis data or output of numerical simulations, Empirical Orthogonal Functions (EOF) obtained as a Proper Orthogonal Decomposition of the data sets have been of great help. However, most of these computations rely on the diagonalisation of space correlation matrices: this means that the considered data set can only have a limited number of gridpoints. The main consequence is that such analyses are often only performed in planes (as function of height and latitude, or longitude and latitude for instance), which makes the educing of the three dimensional structure of the wave quite difficult. In the case of the afore mentionned waves, the matter of the longitudinal dependence or the proper correlation between modes through the tropopause is an open question. An elegant manner to circumvent this problem is to consider the output of the Orthogonal Decomposition as a whole. Indeed, it has been shown that the normalised time series of the amplitude of each EOF, far from just being decorrelated from one another, are actually another set of orthogonal functions. These can actually be computed through the diagonlisation of the time correlation matrix of the data set, just like the EOF were the result of the diagonalisation of the space correlation matrix. The signal is then fully decomposed in the framework of the Bi-Orthogonal Decomposition as the sum of the nth explained variance, time the nth eigenmode of the time correlation times the nth eigenmode of the spacial correlations [2,3]. A practical consequence of this result is that the EOF can be reconstructed from the projection of the dataset onto the eigenmodes of the time correlation matrix in the so-called snapshot method [4]. This is very

  2. Characterization of a detector chain using a FPGA-based time-to-digital converter to reconstruct the three-dimensional coordinates of single particles at high flux

    NASA Astrophysics Data System (ADS)

    Nogrette, F.; Heurteau, D.; Chang, R.; Bouton, Q.; Westbrook, C. I.; Sellem, R.; Clément, D.

    2015-11-01

    We report on the development of a novel FPGA-based time-to-digital converter and its implementation in a detection chain that records the coordinates of single particles along three dimensions. The detector is composed of micro-channel plates mounted on top of a cross delay line and connected to fast electronics. We demonstrate continuous recording of the timing signals from the cross delay line at rates up to 4.1 × 106 s-1 and three-dimensional reconstruction of the coordinates up to 3.2 × 106 particles per second. From the imaging of a calibrated structure we measure the in-plane resolution of the detector to be 140(20) μm at a flux of 3 × 105 particles per second. In addition, we analyze a method to estimate the resolution without placing any structure under vacuum, a significant practical improvement. While we use UV photons here, the results of this work apply to the detection of other kinds of particles.

  3. In-vivo third-harmonic generation microscopy at 1550nm three-dimensional long-term time-lapse studies in living C. elegans embryos

    NASA Astrophysics Data System (ADS)

    Aviles-Espinosa, Rodrigo; Santos, Susana I. C. O.; Brodschelm, Andreas; Kaenders, Wilhelm G.; Alonso-Ortega, Cesar; Artigas, David; Loza-Alvarez, Pablo

    2011-03-01

    In-vivo microscopic long term time-lapse studies require controlled imaging conditions to preserve sample viability. Therefore it is crucial to meet specific exposure conditions as these may limit the applicability of established techniques. In this work we demonstrate the use of third harmonic generation (THG) microscopy for long term time-lapse three-dimensional studies (4D) in living Caenorhabditis elegans embryos employing a 1550 nm femtosecond fiber laser. We take advantage of the fact that THG only requires the existence of interfaces to generate signal or a change in the refractive index or in the χ3 nonlinear coefficient, therefore no markers are required. In addition, by using this wavelength the emitted THG signal is generated at visible wavelengths (516 nm) enabling the use of standard collection optics and detectors operating near their maximum efficiency. This enables the reduction of the incident light intensity at the sample plane allowing to image the sample for several hours. THG signal is obtained through all embryo development stages, providing different tissue/structure information. By means of control samples, we demonstrate that the expected water absorption at this wavelength does not severely compromise sample viability. Certainly, this technique reduces the complexity of sample preparation (i.e. genetic modification) required by established linear and nonlinear fluorescence based techniques. We demonstrate the non-invasiveness, reduced specimen interference, and strong potential of this particular wavelength to be used to perform long-term 4D recordings.

  4. Comparison of wave propagation studies in plasmas using three-dimensional finite-difference time-domain and ray-tracing methods

    SciTech Connect

    Chaudhury, Bhaskar; Chaturvedi, Shashank

    2006-12-15

    Power-flow trajectories of electromagnetic waves through a spatially nonuniform plasma have been computed using direct solutions of Maxwell's equations using the three-dimensional finite-difference time-domain (FDTD) method. This method yields accurate information on refraction as well as absorption effects. The method can be used to compute power-flow trajectories for plasmas with arbitrarily varying density profiles, including effects due to arbitrarily shaped conducting or dielectric surfaces bounding the plasma. Furthermore, since FDTD is computationally expensive, especially for parametric studies, it is desirable to use ray tracing to estimate refraction effects. A quantitative comparison is performed between two different methods of obtaining exact and approximate solutions of Maxwell's equations in order to assess their relative utility in different situations. In the present work, we limit ourselves to a cold, collisional, unmagnetized plasma, where the response to electromagnetic waves is fully specified by a dispersion relation based on magnetoionic theory. It is shown that ray tracing in such plasmas yields accurate results only when two conditions are satisfied. Firstly, the density scale length should be long as compared to the free-space wavelength of the incident wave. Secondly, the conduction current should be small as compared to the displacement current in the medium. The second condition is one which has been identified for the first time.

  5. Characterization of a detector chain using a FPGA-based time-to-digital converter to reconstruct the three-dimensional coordinates of single particles at high flux.

    PubMed

    Nogrette, F; Heurteau, D; Chang, R; Bouton, Q; Westbrook, C I; Sellem, R; Clément, D

    2015-11-01

    We report on the development of a novel FPGA-based time-to-digital converter and its implementation in a detection chain that records the coordinates of single particles along three dimensions. The detector is composed of micro-channel plates mounted on top of a cross delay line and connected to fast electronics. We demonstrate continuous recording of the timing signals from the cross delay line at rates up to 4.1 × 10(6) s(-1) and three-dimensional reconstruction of the coordinates up to 3.2 × 10(6) particles per second. From the imaging of a calibrated structure we measure the in-plane resolution of the detector to be 140(20) μm at a flux of 3 × 10(5) particles per second. In addition, we analyze a method to estimate the resolution without placing any structure under vacuum, a significant practical improvement. While we use UV photons here, the results of this work apply to the detection of other kinds of particles. PMID:26628119

  6. Characterization of a detector chain using a FPGA-based time-to-digital converter to reconstruct the three-dimensional coordinates of single particles at high flux

    SciTech Connect

    Nogrette, F.; Chang, R.; Bouton, Q.; Westbrook, C. I.; Clément, D.; Heurteau, D.; Sellem, R.

    2015-11-15

    We report on the development of a novel FPGA-based time-to-digital converter and its implementation in a detection chain that records the coordinates of single particles along three dimensions. The detector is composed of micro-channel plates mounted on top of a cross delay line and connected to fast electronics. We demonstrate continuous recording of the timing signals from the cross delay line at rates up to 4.1 × 10{sup 6} s{sup −1} and three-dimensional reconstruction of the coordinates up to 3.2 × 10{sup 6} particles per second. From the imaging of a calibrated structure we measure the in-plane resolution of the detector to be 140(20) μm at a flux of 3 × 10{sup 5} particles per second. In addition, we analyze a method to estimate the resolution without placing any structure under vacuum, a significant practical improvement. While we use UV photons here, the results of this work apply to the detection of other kinds of particles.

  7. Space weather and the safety of ground infrastructures. Numerical simulation and prediction of electromagnetic effects induced by real magnetospheric substorms in the Earth's models with real three-dimensional distribution of electrical conductivity

    NASA Astrophysics Data System (ADS)

    Kuvshinov, Alexey; Filippov, Sergey; Kalegaev, Vladimir; Sidorova, Larisa; Mukhametdinova, Ludmila; Pankratov, Oleg; Alexeev, Dmitry

    Strong eruptions at Sun’s surface produce large release of matter (plasma), which, with a speed of 800-1000 km/s (the solar wind), flows into interplanetary space. If the Earth appears to be on the way of the solar wind the interaction of the wind with the Earth's magnetosphere and the ionosphere leads to abnormal disturbance of fluctuating geomagnetic field. In the middle latitudes, the disturbances (geomagnetic storms) last a few days and have amplitudes up to 400 nT. At high latitudes, these perturbations (magnetospheric substorms) last a few hours and have amplitudes up to 3000 nT. According to Faraday’s law of induction, the fluctuating magnetic field in turn generates a electric field. The electric field for intense substorms can reach hundreds of volts/km in the polar region and generate very high, the so-called geomagnetic induced currents in the ground-based systems, such as power grids and pipelines. These currents are one of the most dangerous factors affecting the operation of the above systems. Thus extremely topical task in the field of "space weather" is the quantification and prediction of spatio-temporal distribution of the electric field during substorm activity. Despite the abundance of works carried out in this direction, the problem is still far from a satisfactory solution. In the field of modeling, researchers are still working with highly simplified models of both the source and the conducting Earth. As for prediction the situation is even worse. In this presentation we discuss a general formalism which allows for simulating the electric fields induced by real magnetospheric substorms in the spherical model of the Earth with real three-dimensional distribution of conductivity. We show the first results of such simulations. We also discuss a concept to predict substorm spatio-temporal pattern of the electric field.

  8. Three-dimensional display technologies

    PubMed Central

    Geng, Jason

    2014-01-01

    The physical world around us is three-dimensional (3D), yet traditional display devices can show only two-dimensional (2D) flat images that lack depth (i.e., the third dimension) information. This fundamental restriction greatly limits our ability to perceive and to understand the complexity of real-world objects. Nearly 50% of the capability of the human brain is devoted to processing visual information [Human Anatomy & Physiology (Pearson, 2012)]. Flat images and 2D displays do not harness the brain’s power effectively. With rapid advances in the electronics, optics, laser, and photonics fields, true 3D display technologies are making their way into the marketplace. 3D movies, 3D TV, 3D mobile devices, and 3D games have increasingly demanded true 3D display with no eyeglasses (autostereoscopic). Therefore, it would be very beneficial to readers of this journal to have a systematic review of state-of-the-art 3D display technologies. PMID:25530827

  9. Real time markerless motion tracking using linked kinematic chains

    DOEpatents

    Luck, Jason P.; Small, Daniel E.

    2007-08-14

    A markerless method is described for tracking the motion of subjects in a three dimensional environment using a model based on linked kinematic chains. The invention is suitable for tracking robotic, animal or human subjects in real-time using a single computer with inexpensive video equipment, and does not require the use of markers or specialized clothing. A simple model of rigid linked segments is constructed of the subject and tracked using three dimensional volumetric data collected by a multiple camera video imaging system. A physics based method is then used to compute forces to align the model with subsequent volumetric data sets in real-time. The method is able to handle occlusion of segments and accommodates joint limits, velocity constraints, and collision constraints and provides for error recovery. The method further provides for elimination of singularities in Jacobian based calculations, which has been problematic in alternative methods.

  10. A three-dimensional seismic wave speed model in southwestern Japan from combined use of waveform modeling and travel-time tomography

    NASA Astrophysics Data System (ADS)

    Hayashida, Takumi; Tajima, Fumiko; Nakajima, Junichi; Mori, Jim

    2012-11-01

    Recent three-dimensional (3-D) travel-time tomographic models of southwestern (SW) Japan image the subducting Philippine Sea plate (PHSP) and low velocity anomalies with long-wavelength spatial resolution. However, the agreement between the synthetics calculated with the existing 3-D model and data is not satisfactory forsP and S waves in the higher frequency range (≥0.2 Hz). The unsatisfactory agreement can be attributed to the parameters of the initial wave speed model for the tomographic inversion, as well as the difficulty in detecting S-wave travel times accurately. In order to improve the wave speed model, we first constructed a 3-D reference model by forward modeling using waveform data from an intraslab earthquake and then performed repeated travel-time inversions using the 3-D reference model as the initial model. The newly derived high-resolution model 3DM_SWJ can produce synthetics that are substantially in better agreement with the data than previous models. The distribution of highP-wave toS-wave speed ratios (VP/VS) calculated from model 3DM_SWJ shows short-wavelength heterogeneities that could have been formed in relation to the subduction of the Philippine Sea Plate beneath the Eurasian plate. This combined use of forward waveform modeling for slab and crust configuration and repeated tomographic inversion of travel-times provides a better 3-D structural model of seismic properties for understanding tectonic features related to the subduction process, in addition to better estimating ground motions.

  11. Real time polarimetric dehazing.

    PubMed

    Mudge, Jason; Virgen, Miguel

    2013-03-20

    Remote sensing is a rich topic due to its utility in gathering detailed accurate information from locations that are not economically feasible traveling destinations or are physically inaccessible. However, poor visibility over long path lengths is problematic for a variety of reasons. Haze induced by light scatter is one cause for poor visibility and is the focus of this article. Image haze comes about as a result of light scattering off particles and into the imaging path causing a haziness to appear on the image. Image processing using polarimetric information of light scatter can be used to mitigate image haze. An imaging polarimeter which provides the Stokes values in real time combined with a "dehazing" algorithm can automate image haze removal for instant applications. Example uses are to improve visual display providing on-the-spot detection or imbedding in an active control loop to improve viewing and tracking while on a moving platform. In addition, removing haze in this manner allows the trade space for a system operational waveband to be opened up to bands which are object matched and not necessarily restricted by scatter effects. PMID:23518739

  12. Three-dimensional microbubble streaming flows

    NASA Astrophysics Data System (ADS)

    Rallabandi, Bhargav; Marin, Alvaro; Rossi, Massimiliano; Kaehler, Christian; Hilgenfeldt, Sascha

    2014-11-01

    Streaming due to acoustically excited bubbles has been used successfully for applications such as size-sorting, trapping and focusing of particles, as well as fluid mixing. Many of these applications involve the precise control of particle trajectories, typically achieved using cylindrical bubbles, which establish planar flows. Using astigmatic particle tracking velocimetry (APTV), we show that, while this two-dimensional picture is a useful description of the flow over short times, a systematic three-dimensional flow structure is evident over long time scales. We demonstrate that this long-time three-dimensional fluid motion can be understood through asymptotic theory, superimposing secondary axial flows (induced by boundary conditions at the device walls) onto the two-dimensional description. This leads to a general framework that describes three-dimensional flows in confined microstreaming systems, guiding the design of applications that profit from minimizing or maximizing these effects.

  13. Three-Dimensional Tomography of Interplanetary Disturbances

    NASA Astrophysics Data System (ADS)

    Jackson, Bernard V.; Hick, P. Paul

    2004-09-01

    We have developed a Computer Assisted Tomography (CAT) program that modifies a three-dimensional kinematic heliospheric model to fit interplanetary scintillation (IPS) or Thomson scattering observations. The tomography program iteratively changes this global model to least-squares fit the data. Both a corotating and time-dependent model can be reconstructed. The short time intervals of the time-dependent modeling (to shorter than 1 day) force the heliospheric reconstructions to depend on outward solar wind motion to give perspective views of each point in space accessible to the observations, allowing reconstruction of interplanetary Coronal Mass Ejections (CMEs) as well as corotating structures. We show these models as velocity or density Carrington maps and remote views. We have studied several events, including the 2000 July 14 Bastille-Day halo CME and several intervals using archival Cambridge IPS data, and we have also used archival Helios photometer data to reproduce the heliosphere. We check our results by comparison with additional remote-sensing observations, and in-situ observations from near-Earth spacecraft. A comparison of these observations and the Earth forecasts possible using them is available in real time on the World Wide Web using IPS data from the Solar Terrestrial Environment Laboratory, Japan.

  14. Performance of asynchronous fiber-optic code division multiple access system based on three-dimensional wavelength/time/space codes and its link analysis.

    PubMed

    Singh, Jaswinder

    2010-03-10

    A novel family of three-dimensional (3-D) wavelength/time/space codes for asynchronous optical code-division-multiple-access (CDMA) systems with "zero" off-peak autocorrelation and "unity" cross correlation is reported. Antipodal signaling and differential detection is employed in the system. A maximum of [(W x T+1) x W] codes are generated for unity cross correlation, where W and T are the number of wavelengths and time chips used in the code and are prime. The conditions for violation of the cross-correlation constraint are discussed. The expressions for number of generated codes are determined for various code dimensions. It is found that the maximum number of codes are generated for S < or = min(W,T), where W and T are prime and S is the number of space channels. The performance of these codes is compared to the earlier reported two-dimensional (2-D)/3-D codes for asynchronous systems. The codes have a code-set-size to code-size ratio greater than W/S. For instance, with a code size of 2065 (59 x 7 x 5), a total of 12,213 users can be supported, and 130 simultaneous users at a bit-error rate (BER) of 10(-9). An arrayed-waveguide-grating-based reconfigurable encoder/decoder design for 2-D implementation for the 3-D codes is presented so that the need for multiple star couplers and fiber ribbons is eliminated. The hardware requirements of the coders used for various modulation/detection schemes are given. The effect of insertion loss in the coders is shown to be significantly reduced with loss compensation by using an amplifier after encoding. An optical CDMA system for four users is simulated and the results presented show the improvement in performance with the use of loss compensation. PMID:20220892

  15. Steerable real-time sonographically guided needle biopsy.

    PubMed

    Buonocore, E; Skipper, G J

    1981-02-01

    A method for dynamic real-time ultrasonic guidance for percutaneous needle biopsy has been successful in obtaining cytologic and histologic specimens from abdominal masses. The system depends on a real-time ultrasonic transducer that has been rigidly attached to a laterally placed steerable needle holder. Using simple trigonometric functions, a chart has been derived that gives the exact angulation and needle length to produce quick, reliable, guided needle placements. Examples of successful renal, hepatobiliary, and retroperitoneal biopsies are presented. Advantages of this technique include speed, accuracy, low cost, three-dimensional format, and the omission of contrast media and radiation. PMID:6781264

  16. Real-Time Benchmark Suite

    Energy Science and Technology Software Center (ESTSC)

    1992-01-17

    This software provides a portable benchmark suite for real time kernels. It tests the performance of many of the system calls, as well as the interrupt response time and task response time to interrupts. These numbers provide a baseline for comparing various real-time kernels and hardware platforms.

  17. In vivo micro-computed tomography allows direct three-dimensional quantification of both bone formation and bone resorption parameters using time-lapsed imaging.

    PubMed

    Schulte, Friederike A; Lambers, Floor M; Kuhn, Gisela; Müller, Ralph

    2011-03-01

    Bone is a living tissue able to adapt its structure to external influences such as altered mechanical loading. This adaptation process is governed by two distinct cell types: bone-forming cells called osteoblasts and bone-resorbing cells called osteoclasts. It is therefore of particular interest to have quantitative access to the outcomes of bone formation and resorption separately. This article presents a non-invasive three-dimensional technique to directly extract bone formation and resorption parameters from time-lapsed in vivo micro-computed tomography scans. This includes parameters such as Mineralizing Surface (MS), Mineral Apposition Rate (MAR), and Bone Formation Rate (BFR), which were defined in accordance to the current nomenclature of dynamic histomorphometry. Due to the time-lapsed and non-destructive nature of in vivo micro-computed tomography, not only formation but also resorption can now be assessed quantitatively and time-dependent parameters Eroded Surface (ES) as well as newly defined indices Mineral Resorption Rate (MRR) and Bone Resorption Rate (BRR) are introduced. For validation purposes, dynamic formation parameters were compared to the traditional quantitative measures of dynamic histomorphometry, where MAR correlated with R = 0.68 and MS with R = 0.78 (p < 0.05). Reproducibility was assessed in 8 samples that were scanned 5 times and errors ranged from 0.9% (MRR) to 6.6% (BRR). Furthermore, the new parameters were applied to a murine in vivo loading model. A comparison of directly extracted parameters between formation and resorption within each animal revealed that in the control group, i.e., during normal remodeling, MAR was significantly lower than MRR (p < 0.01), whereas MS compared to ES was significantly higher (p < 0.0001). This implies that normal remodeling seems to take place by many small formation packets and few but large resorption volumes. After 4 weeks of mechanical loading, newly extracted trabecular BFR and MS were

  18. Three-Dimensional Schlieren Measurements

    NASA Astrophysics Data System (ADS)

    Sutherland, Bruce; Cochrane, Andrea

    2004-11-01

    Schlieren systems visualise disturbances that change the index of refraction of a fluid, for example due to temperature or salinity disturbances. `Synthetic schlieren' refers to a recent advance in which these disturbances are visualised with a digital camera and image-processing technology rather than the classical use of parabolic mirrors and a knife-edge. In a typical setup, light from an image of horizontal lines or dots passes almost horizontally through the test section of a fluid to a CCD camera. Refractive index disturbances distort the image and digital comparison of successive images reveals the plan-form structure and time evolution of the disturbances. If the disturbance is effectively two-dimensional, meaning that it is uniform across the line-of-sight of the camera, then its magnitude as well as its structure can measured through simple inversion of an algebraic equation. If the structure is axisymmetric with rotation-axis perpendicular to the line of sight, the magnitude of the disturbance can be measured through inversion of a non-singular square matrix. Here we report upon the extension of this work toward measuring the magnitude of a fully three-dimensional disturbance. This is done by analysing images from two perspectives through the test section and using inversion tomography techniques to reconstruct the disturbance field. The results are tested against theoretical predictions and experimental measurements.

  19. Application of a real-space three-dimensional image reconstruction method in the structural analysis of noncrystalline biological macromolecules enveloped by water in coherent x-ray diffraction microscopy.

    PubMed

    Kodama, Wataru; Nakasako, Masayoshi

    2011-08-01

    Coherent x-ray diffraction microscopy is a novel technique in the structural analyses of particles that are difficult to crystallize, such as the biological particles composing living cells. As water is indispensable for maintaining particles in functional structures, sufficient hydration of targeted particles is required during sample preparation for diffraction microscopy experiments. However, the water enveloping particles also contributes significantly to the diffraction patterns and reduces the electron-density contrast of the sample particles. In this study, we propose a protocol for the structural analyses of particles in water by applying a three-dimensional reconstruction method in real space for the projection images phase-retrieved from diffraction patterns, together with a developed density modification technique. We examined the feasibility of the protocol through three simulations involving a protein molecule in a vacuum, and enveloped in either a droplet or a cube-shaped water. The simulations were carried out for the diffraction patterns in the reciprocal planes normal to the incident x-ray beam. This assumption and the simulation conditions corresponded to experiments using x-ray wavelengths of shorter than 0.03 Å. The analyses demonstrated that our protocol provided an interpretable electron-density map. Based on the results, we discuss the advantages and limitations of the proposed protocol and its practical application for experimental data. In particular, we examined the influence of Poisson noise in diffraction patterns on the reconstructed three-dimensional electron density in the proposed protocol. PMID:21929015

  20. Three-dimensional rf structure calculations

    SciTech Connect

    Cooper, R.K.; Browman, M.J.; Weiland, T.

    1988-01-01

    The calculation of three-dimensional rf structures is rapidly approaching adolescence, after having been in its infancy for the last four years. This paper will show the kinds of calculations that are currently being performed in the frequency domain and is a companion paper to one in which time-domain calculations are described. 13 refs., 14 figs.

  1. Three-dimensional RF structure calculations

    NASA Astrophysics Data System (ADS)

    Cooper, R. K.; Browman, M. J.; Weiland, T.

    1989-04-01

    The calculation of three-dimensional rf structures is rapidly approaching adolescence, after having been in its infancy for the last four years. This paper will show the kinds of calculations that are currently being performed in the frequency domain and is a companion paper to one in which time-domain calculations are described.

  2. Three-dimensional marginal separation

    NASA Technical Reports Server (NTRS)

    Duck, Peter W.

    1988-01-01

    The three dimensional marginal separation of a boundary layer along a line of symmetry is considered. The key equation governing the displacement function is derived, and found to be a nonlinear integral equation in two space variables. This is solved iteratively using a pseudo-spectral approach, based partly in double Fourier space, and partly in physical space. Qualitatively, the results are similar to previously reported two dimensional results (which are also computed to test the accuracy of the numerical scheme); however quantitatively the three dimensional results are much different.

  3. Three-dimensional silicon micromachining

    NASA Astrophysics Data System (ADS)

    Azimi, S.; Song, J.; Dang, Z. Y.; Liang, H. D.; Breese, M. B. H.

    2012-11-01

    A process for fabricating arbitrary-shaped, two- and three-dimensional silicon and porous silicon components has been developed, based on high-energy ion irradiation, such as 250 keV to 1 MeV protons and helium. Irradiation alters the hole current flow during subsequent electrochemical anodization, allowing the anodization rate to be slowed or stopped for low/high fluences. For moderate fluences the anodization rate is selectively stopped only at depths corresponding to the high defect density at the end of ion range, allowing true three-dimensional silicon machining. The use of this process in fields including optics, photonics, holography and nanoscale depth machining is reviewed.

  4. Time dependent three-dimensional body frame quantal wave packet treatment of the H + H2 exchange reaction on the Liu-Siegbahn-Truhlar-Horowitz (LSTH) surface

    NASA Technical Reports Server (NTRS)

    Neuhauser, Daniel; Baer, Michael; Judson, Richard S.; Kouri, Donald J.

    1989-01-01

    The first successful application of the three-dimensional quantum body frame wave packet approach to reactive scattering is reported for the H + H2 exchange reaction on the LSTH potential surface. The method used is based on a procedure for calculating total reaction probabilities from wave packets. It is found that converged, vibrationally resolved reactive probabilities can be calculated with a grid that is not much larger than required for the pure inelastic calculation. Tabular results are presented for several energies.

  5. Joint Inversion of Body-Wave Arrival Times and Surface-Wave Dispersion Data for Three-Dimensional Seismic Velocity Structure Around SAFOD

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Thurber, C. H.; Maceira, M.; Roux, P.

    2013-12-01

    The crust around the San Andreas Fault Observatory at depth (SAFOD) has been the subject of many geophysical studies aimed at characterizing in detail the fault zone structure and elucidating the lithologies and physical properties of the surrounding rocks. Seismic methods in particular have revealed the complex two-dimensional (2D) and three-dimensional (3D) structure of the crustal volume around SAFOD and the strong velocity reduction in the fault damage zone. In this study we conduct a joint inversion using body-wave arrival times and surface-wave dispersion data to image the P-and S-wave velocity structure of the upper crust surrounding SAFOD. The two data types have complementary strengths - the body-wave data have good resolution at depth, albeit only where there are crossing rays between sources and receivers, whereas the surface waves have very good near-surface resolution and are not dependent on the earthquake source distribution because they are derived from ambient noise. The body-wave data are from local earthquakes and explosions, comprising the dataset analyzed by Zhang et al. (2009). The surface-wave data are for Love waves from ambient noise correlations, and are from Roux et al. (2011). The joint inversion code is based on the regional-scale version of the double-difference (DD) tomography algorithm tomoDD. The surface-wave inversion code that is integrated into the joint inversion algorithm is from Maceira and Ammon (2009). The propagator matrix solver in the algorithm DISPER80 (Saito, 1988) is used for the forward calculation of dispersion curves from layered velocity models. We examined how the structural models vary as we vary the relative weighting of the fit to the two data sets and in comparison to the previous separate inversion results. The joint inversion with the 'optimal' weighting shows more clearly the U-shaped local structure from the Buzzard Canyon Fault on the west side of SAF to the Gold Hill Fault on the east side.

  6. Three dimensional characterization and archiving system

    SciTech Connect

    Sebastian, R.L.; Clark, R.; Gallman, P.

    1996-04-01

    The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D and D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D and D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. Real-time remotely operable characterization instrumentation will significantly advance the analysis capabilities beyond those currently employed. Chemical analysis is a primary area where the characterization process will be improved. The 3D-ICAS system robotically conveys a multisensor probe near the surfaces to be inspected. The sensor position and orientation are monitored and controlled using coherent laser radar (CLR) tracking. The CLR also provides 3D facility maps which establish a 3D world view within which the robotic sensor system can operate.

  7. Automatic creation of three-dimensional avatars

    NASA Astrophysics Data System (ADS)

    Villa-Uriol, Maria-Cruz; Sainz, Miguel; Kuester, Falko; Bagherzadeh, Nader

    2003-01-01

    Highly accurate avatars of humans promise a new level of realism in engineering and entertainment applications, including areas such as computer animated movies, computer game development interactive virtual environments and tele-presence. In order to provide high-quality avatars, new techniques for the automatic acquisition and creation are required. A framework for the capture and construction of arbitrary avatars from image data is presented in this paper. Avatars are automatically reconstructed from multiple static images of a human subject by utilizing image information to reshape a synthetic three-dimensional articulated reference model. A pipeline is presented that combines a set of hardware-accelerated stages into one seamless system. Primary stages in this pipeline include pose estimation, skeleton fitting, body part segmentation, geometry construction and coloring, leading to avatars that can be animated and included into interactive environments. The presented system removes traditional constraints in the initial pose of the captured subject by using silhouette-based modification techniques in combination with a reference model. Results can be obtained in near-real time with very limited user intervention.

  8. Three-Dimensional Images For Robot Vision

    NASA Astrophysics Data System (ADS)

    McFarland, William D.

    1983-12-01

    Robots are attracting increased attention in the industrial productivity crisis. As one significant approach for this nation to maintain technological leadership, the need for robot vision has become critical. The "blind" robot, while occupying an economical niche at present is severely limited and job specific, being only one step up from the numerical controlled machines. To successfully satisfy robot vision requirements a three dimensional representation of a real scene must be provided. Several image acquistion techniques are discussed with more emphasis on the laser radar type instruments. The autonomous vehicle is also discussed as a robot form, and the requirements for these applications are considered. The total computer vision system requirement is reviewed with some discussion of the major techniques in the literature for three dimensional scene analysis.

  9. Three dimensional colorimetric assay assemblies

    SciTech Connect

    Charych, D.; Reichart, A.

    2000-06-27

    A direct assay is described using novel three-dimensional polymeric assemblies which change from a blue to red color when exposed to an analyte, in one case a flu virus. The assemblies are typically in the form of liposomes which can be maintained in a suspension, and show great intensity in their color changes. Their method of production is also described.

  10. Creating Three-Dimensional Scenes

    ERIC Educational Resources Information Center

    Krumpe, Norm

    2005-01-01

    Persistence of Vision Raytracer (POV-Ray), a free computer program for creating photo-realistic, three-dimensional scenes and a link for Mathematica users interested in generating POV-Ray files from within Mathematica, is discussed. POV-Ray has great potential in secondary mathematics classrooms and helps in strengthening students' visualization…

  11. Three-dimensional stellarator codes

    PubMed Central

    Garabedian, P. R.

    2002-01-01

    Three-dimensional computer codes have been used to develop quasisymmetric stellarators with modular coils that are promising candidates for a magnetic fusion reactor. The mathematics of plasma confinement raises serious questions about the numerical calculations. Convergence studies have been performed to assess the best configurations. Comparisons with recent data from large stellarator experiments serve to validate the theory. PMID:12140367

  12. Three dimensional colorimetric assay assemblies

    DOEpatents

    Charych, Deborah; Reichart, Anke

    2000-01-01

    A direct assay is described using novel three-dimensional polymeric assemblies which change from a blue to red color when exposed to an analyte, in one case a flu virus. The assemblies are typically in the form of liposomes which can be maintained in a suspension, and show great intensity in their color changes. Their method of production is also described.

  13. Three-Dimensional Lissajous Figures.

    ERIC Educational Resources Information Center

    D'Mura, John M.

    1989-01-01

    Described is a mechanically driven device for generating three-dimensional harmonic space figures with different frequencies and phase angles on the X, Y, and Z axes. Discussed are apparatus, viewing stereo pairs, equations of motion, and using space figures in classroom. (YP)

  14. Real-time tracking of objects for space applications using a laser range scanner

    NASA Technical Reports Server (NTRS)

    Blais, F.; Couvillon, R. A.; Rioux, M.; Maclean, S. G.

    1994-01-01

    Real-time tracking of multiple targets and three dimensional object features was demonstrated using a laser range scanner. The prototype was immune to ambient illumination and sun interference. Tracking error feedback was simultaneously obtained from individual targets, global predicted target position, and the human operator. A more complete study of calibration parameters and temperature variations on the scanner is needed to determine the exact performance of the sensor. Lissajous patterns used in three-dimensional real-time tracking prove helpful given their high resolution. The photogrammetry-based Advanced Space Vision System (ASVS) is discussed in combination with the laser range scanner.

  15. Three-Dimensional Messages for Interstellar Communication

    NASA Astrophysics Data System (ADS)

    Vakoch, Douglas A.

    One of the challenges facing independently evolved civilizations separated by interstellar distances is to communicate information unique to one civilization. One commonly proposed solution is to begin with two-dimensional pictorial representations of mathematical concepts and physical objects, in the hope that this will provide a foundation for overcoming linguistic barriers. However, significant aspects of such representations are highly conventional, and may not be readily intelligible to a civilization with different conventions. The process of teaching conventions of representation may be facilitated by the use of three-dimensional representations redundantly encoded in multiple formats (e.g., as both vectors and as rasters). After having illustrated specific conventions for representing mathematical objects in a three-dimensional space, this method can be used to describe a physical environment shared by transmitter and receiver: a three-dimensional space defined by the transmitter--receiver axis, and containing stars within that space. This method can be extended to show three-dimensional representations varying over time. Having clarified conventions for representing objects potentially familiar to both sender and receiver, novel objects can subsequently be depicted. This is illustrated through sequences showing interactions between human beings, which provide information about human behavior and personality. Extensions of this method may allow the communication of such culture-specific features as aesthetic judgments and religious beliefs. Limitations of this approach will be noted, with specific reference to ETI who are not primarily visual.

  16. Random access three-dimensional two-photon microscopy.

    PubMed

    Rózsa, Balázs; Katona, Gergely; Vizi, E Sylvester; Várallyay, Zoltán; Sághy, Attila; Valenta, Lásló; Maák, Pál; Fekete, Júlia; Bányász, Akos; Szipocs, Róbert

    2007-04-01

    We propose a two-photon microscope scheme capable of real-time, three-dimensional investigation of the electric activity pattern of neural networks or signal summation rules of individual neurons in a 0.6 mm x 0.6 mm x 0.2 mm volume of the sample. The points of measurement are chosen according to a conventional scanning two-photon image, and they are addressed by separately adjustable optical fibers. This allows scanning at kilohertz repetition rates of as many as 100 data points. Submicrometer spatial resolution is maintained during the measurement similarly to conventional two-photon microscopy. PMID:17356631

  17. Three dimensional vision - Requirements and applications in a space environment

    NASA Technical Reports Server (NTRS)

    Noseworthy, J. R.; Gerhardt, Lester A.

    1991-01-01

    Various approaches to three-dimensional vision in space are reviewed with emphasis on the redundant 3D vision system designed for the Center for Intelligent Robotic Systems for Space Exploration. The system uses a controllable subset of five cameras, programmable structured light patterns, and sophisticated calibration routines. The design emphasizes real-time operation, human supervisory intervention, and the use of 3D vision to enhance the performance of cooperating robotic arms. Two methods of estimating the location of a point using 3D vision are discussed.

  18. Real-time visualization of coronary interventions using VRML

    NASA Astrophysics Data System (ADS)

    Mitchell, Steven C.; Wahle, Andreas; von Birgelen, Clemens; Erbel, Raimund; Sonka, Milan

    1999-05-01

    Medical visualization is a rapidly developing field with many application areas spanning from visualization of anatomy to surgery planning, to understanding of disease processes. With increasing computer speed, medical visualization is becoming more real-time. In this paper, we present a novel application of real-time three-dimensional visualization of coronary arteries during catheter interventions that combines image information from two complementary sources: biplane x-ray contrast angiography and intravascular ultrasound (IVUS). After identification of the three-dimensional characteristics of the intravascular ultrasound pullback sequence, vessel geometry and vessel wall images are combined into a single visualization using semi-automated analysis of a corresponding pair of biplane angiography images. Visualization data are represented using the Virtual Reality Modeling Language (VRML), the code for which is automatically generated by our angiography/IVUS image processing and analysis software system. Selection of the VRML approach facilitates real-time 3-D visualization with an ability of over-the-network image processing and dissemination of results. The visualization specifics are easily modifiable in near real time to consider the immediate requirements of the end-user, the cardiologist who performs the coronary intervention.

  19. Conjugate imagery in the automated reproduction of three dimensional coordinates from two dimensional coordinate data.

    PubMed

    Carman, A B; Milburn, P D

    1997-07-01

    The three-dimensional video analysis of human motion commonly utilises automated image processing and digitisation processes to produce real-time unidentified two-dimensional coordinate data of segmental markers. In what can be a time-consuming process the two-dimensional data are then identified and tracked to produce three-dimensional coordinates. This paper presents an approach to the automated reproduction of three-dimensional coordinates from two-dimensional coordinates data. Conjugate imaging techniques were utilised in the development of four criterion measures for determining the validity of conjugate (corresponding) image points. An algorithm based on the criterion measures was then developed for the automated reproduction of three dimensional coordinates from camera image coordinate data. The algorithm was tested with a 55 point marker system viewed in four video cameras (digitisation error approx. 0.2%, lab point separation > or = 6 cm). The success of the algorithm was dependent on the closeness of markers, the accuracy of the photogrammetric system, and the number of markers visible in two camera images. The present research has developed techniques based on conjugate imagery for the automated reproduction of three-dimensional coordinates from two-dimensional data, and provided a bases for further development of automated three-dimensional tracking. PMID:9239554

  20. Acoustic streaming in an ultrasonic air pump with three-dimensional finite-difference time-domain analysis and comparison to the measurement.

    PubMed

    Wada, Yuji; Koyama, Daisuke; Nakamura, Kentaro

    2014-12-01

    The direct finite-difference fluid simulation of acoustic streaming on a fine-meshed three-dimensional model using a graphics processing unit (GPU)-based calculation array is discussed. Airflows are induced by an acoustic traveling wave when an intense sound field is generated in a gap between a bending transducer and a reflector. The calculation results showed good agreement with measurements in a pressure distribution. Several flow vortices were observed near the boundary layer of the reflector and the transducer, which have often been observed near the boundary of acoustic tubes, but have not been observed in previous calculations for this type of ultrasonic air pump. PMID:25001051

  1. Real Time Baseball Database

    NASA Astrophysics Data System (ADS)

    Fukue, Yasuhiro

    The author describes the system outline, features and operations of "Nikkan Sports Realtime Basaball Database" which was developed and operated by Nikkan Sports Shimbun, K. K. The system enables to input numerical data of professional baseball games as they proceed simultaneously, and execute data updating at realtime, just-in-time. Other than serving as supporting tool for prepareing newspapers it is also available for broadcasting media, general users through NTT dial Q2 and others.

  2. Real-time flutter identification

    NASA Technical Reports Server (NTRS)

    Roy, R.; Walker, R.

    1985-01-01

    The techniques and a FORTRAN 77 MOdal Parameter IDentification (MOPID) computer program developed for identification of the frequencies and damping ratios of multiple flutter modes in real time are documented. Physically meaningful model parameterization was combined with state of the art recursive identification techniques and applied to the problem of real time flutter mode monitoring. The performance of the algorithm in terms of convergence speed and parameter estimation error is demonstrated for several simulated data cases, and the results of actual flight data analysis from two different vehicles are presented. It is indicated that the algorithm is capable of real time monitoring of aircraft flutter characteristics with a high degree of reliability.

  3. Three-dimensional fault drawing

    SciTech Connect

    Dongan, L. )

    1992-01-01

    In this paper, the author presents a structure interpretation based on three-dimensional fault drawing. It is required that fault closure must be based on geological theory, spacial plotting principle and restrictions in seismic exploration. Geological structure can be well ascertained by analysing the shapes and interrelation of the faults which have been drawn through reasonable fault point closure and fault point correlation. According to this method, the interrelation of fault points is determined by first closing corresponding fault points in intersecting sections, then reasonably correlating the relevant fault points. Fault point correlation is not achieved in base map, so its correctness can be improved greatly. Three-dimensional fault closure is achieved by iteratively revising. The closure grid should be densified gradually. The distribution of major fault system is determined prior to secondary faults. Fault interpretation by workstation also follows this procedure.

  4. Real-time vision systems

    SciTech Connect

    Johnson, R.; Hernandez, J.E.; Lu, Shin-yee

    1994-11-15

    Many industrial and defence applications require an ability to make instantaneous decisions based on sensor input of a time varying process. Such systems are referred to as `real-time systems` because they process and act on data as it occurs in time. When a vision sensor is used in a real-time system, the processing demands can be quite substantial, with typical data rates of 10-20 million samples per second. A real-time Machine Vision Laboratory (MVL) was established in FY94 to extend our years of experience in developing computer vision algorithms to include the development and implementation of real-time vision systems. The laboratory is equipped with a variety of hardware components, including Datacube image acquisition and processing boards, a Sun workstation, and several different types of CCD cameras, including monochrome and color area cameras and analog and digital line-scan cameras. The equipment is reconfigurable for prototyping different applications. This facility has been used to support several programs at LLNL, including O Division`s Peacemaker and Deadeye Projects as well as the CRADA with the U.S. Textile Industry, CAFE (Computer Aided Fabric Inspection). To date, we have successfully demonstrated several real-time applications: bullet tracking, stereo tracking and ranging, and web inspection. This work has been documented in the ongoing development of a real-time software library.

  5. Three-dimensional obstetric ultrasound.

    PubMed

    Tache, Veronique; Tarsa, Maryam; Romine, Lorene; Pretorius, Dolores H

    2008-04-01

    Three-dimensional ultrasound has gained a significant popularity in obstetrical practice in recent years. The advantage of this modality in some cases is in question, however. This article provides a basic review of volume acquisition, mechanical positioning, and display modalities. Multiple uses of this technique in obstetrical care including first trimester applications and its utility in clarification of fetal anatomy such as brain, face, heart, and skeleton is discussed. PMID:18450140

  6. Three-dimensional coronary angiography

    NASA Astrophysics Data System (ADS)

    Suurmond, Rolf; Wink, Onno; Chen, James; Carroll, John

    2005-04-01

    Three-Dimensional Coronary Angiography (3D-CA) is a novel tool that allows clinicians to view and analyze coronary arteries in three-dimensional format. This will help to find accurate length estimates and to find the optimal viewing angles of a lesion based on the three-dimensional vessel orientation. Various advanced algorithms are incorporated in this 3D processing utility including 3D-RA calibration, ECG phase selection, 2D vessel extraction, and 3D vessel modeling into a utility with optimized workflow and ease-of-use features, which is fully integrated in the environment of the x-ray catheterization lab. After the 3D processing, the 3D vessels can be viewed and manipulated interactively inside the operating room. The TrueView map provides a quick overview of gantry angles with optimal visualization of a single or bifurcation lesion. Vessel length measurements can be performed without risk of underestimating a vessel segment due to foreshortening. Vessel cross sectional diameters can also be measured. Unlike traditional, projection-based quantitative coronary analysis, the additional process of catheter calibration is not needed for diameter measurements. Validation studies show a high reproducibility of the measurements, with little user dependency.

  7. Real-time software receiver

    NASA Technical Reports Server (NTRS)

    Ledvina, Brent M. (Inventor); Psiaki, Mark L. (Inventor); Powell, Steven P. (Inventor); Kintner, Jr., Paul M. (Inventor)

    2007-01-01

    A real-time software receiver that executes on a general purpose processor. The software receiver includes data acquisition and correlator modules that perform, in place of hardware correlation, baseband mixing and PRN code correlation using bit-wise parallelism.

  8. Real-time refinery optimization

    SciTech Connect

    Kennedy, J.P.

    1989-05-01

    This article discusses refinery operation with specific consideration of the topics of: gasoline; control projects; catalytic reforming control; hydrocracker control packages; blending optimization; real-time data acquisition; and other plant automation packages.

  9. Real-time software receiver

    NASA Technical Reports Server (NTRS)

    Ledvina, Brent M. (Inventor); Psiaki, Mark L. (Inventor); Powell, Steven P. (Inventor); Kintner, Jr., Paul M. (Inventor)

    2006-01-01

    A real-time software receiver that executes on a general purpose processor. The software receiver includes data acquisition and correlator modules that perform, in place of hardware correlation, baseband mixing and PRN code correlation using bit-wise parallelism.

  10. Real Time Data System (RTDS)

    NASA Technical Reports Server (NTRS)

    Muratore, John F.

    1991-01-01

    Lessons learned from operational real time expert systems are examined. The basic system architecture is discussed. An expert system is any software that performs tasks to a standard that would normally require a human expert. An expert system implies knowledge contained in data rather than code. And an expert system implies the use of heuristics as well as algorithms. The 15 top lessons learned by the operation of a real time data system are presented.

  11. Three-dimensional simulation of vortex breakdown

    NASA Technical Reports Server (NTRS)

    Kuruvila, G.; Salas, M. D.

    1990-01-01

    The integral form of the complete, unsteady, compressible, three-dimensional Navier-Stokes equations in the conservation form, cast in generalized coordinate system, are solved, numerically, to simulate the vortex breakdown phenomenon. The inviscid fluxes are discretized using Roe's upwind-biased flux-difference splitting scheme and the viscous fluxes are discretized using central differencing. Time integration is performed using a backward Euler ADI (alternating direction implicit) scheme. A full approximation multigrid is used to accelerate the convergence to steady state.

  12. Analysis of three-dimensional transonic compressors

    NASA Technical Reports Server (NTRS)

    Bourgeade, A.

    1984-01-01

    A method for computing the three-dimensional transonic flow around the blades of a compressor or of a propeller is given. The method is based on the use of the velocity potential, on the hypothesis that the flow is inviscid, irrotational and isentropic. The equation of the potential is solved in a transformed space such that the surface of the blade is mapped into a plane where the periodicity is implicit. This equation is in a nonconservative form and is solved with the help of a finite difference method using artificial time. A computer code is provided and some sample results are given in order to demonstrate the influence of three-dimensional effects and the blade's rotation.

  13. A preconditioned dual–primal finite element tearing and interconnecting method for solving three-dimensional time-harmonic Maxwell's equations

    SciTech Connect

    Xue, Ming-Feng; Jin, Jian-Ming

    2014-10-01

    A new preconditioned dual–primal nonoverlapping domain decomposition method is proposed for the finite element solution of three-dimensional large-scale electromagnetic problems. With the aid of two Lagrange multipliers, the new method converts the original volumetric problem to a surface problem by using a higher-order transmission condition at the subdomain interfaces to significantly improve the convergence of the iterative solution of the global interface equation. Similar to the previous version, a global coarse problem related to the degrees of freedom at the subdomain corner edges is formulated to propagate the residual error to the whole computational domain at each iteration, which further increases the rate of convergence. In addition, a fully algebraic preconditioner based on matrix splitting is constructed to make the proposed domain decomposition method even more robust and scalable. Perfectly matched layers (PMLs) are considered for the boundary truncation when solving open-region problems. The influence of the PML truncation on the convergence performance is investigated by examining the convergence of the transmission condition for an interface inside the PML. Numerical examples including wave propagation and antenna radiation problems truncated with PMLs are presented to demonstrate the validity and the capability of this method.

  14. On Using Taylor's Hypothesis for Three-Dimensional Mixing Layers

    NASA Technical Reports Server (NTRS)

    LeBoeuf, Richard L.; Mehta, Rabindra D.

    1995-01-01

    In the present study, errors in using Taylor's hypothesis to transform measurements obtained in a temporal (or phase) frame onto a spatial one were evaluated. For the first time, phase-averaged ('real') spanwise and streamwise vorticity data measured on a three-dimensional grid were compared directly to those obtained using Taylor's hypothesis. The results show that even the qualitative features of the spanwise and streamwise vorticity distributions given by the two techniques can be very different. This is particularly true in the region of the spanwise roller pairing. The phase-averaged spanwise and streamwise peak vorticity levels given by Taylor's hypothesis are typically lower (by up to 40%) compared to the real measurements.

  15. Three-dimensional laparoscope based on the manipulation of polarized light by a cellophane half-wave plate

    NASA Astrophysics Data System (ADS)

    Iizuka, Keigo

    2005-11-01

    A three-dimensional laparoscope that can capture three-dimensional images during surgery is reported. The principle is solely based on the manipulation of polarized light by a cellophane half-wave plate rather than computer processing; hence there is no time delay (it operates in real time) and lesions are viewed in true color, which is important for diagnostics. Three-dimensional images are obtained with a single laparoscope. A unique feature of this three-dimensional laparoscope is that it includes a virtual ruler to measure distances without physically touching the affected areas. The structure is simple, sturdy, lightweight, and its diameter is no bigger than a standard 10 mm diam laparoscope.

  16. Three-dimensional coil inductor

    DOEpatents

    Bernhardt, Anthony F.; Malba, Vincent

    2002-01-01

    A three-dimensional coil inductor is disclosed. The inductor includes a substrate; a set of lower electrically conductive traces positioned on the substrate; a core placed over the lower traces; a set of side electrically conductive traces laid on the core and the lower traces; and a set of upper electrically conductive traces attached to the side traces so as to form the inductor. Fabrication of the inductor includes the steps of forming a set of lower traces on a substrate; positioning a core over the lower traces; forming a set of side traces on the core; connecting the side traces to the lower traces; forming a set of upper traces on the core; and connecting the upper traces to the side traces so as to form a coil structure.

  17. Real Time Sonic Boom Display

    NASA Technical Reports Server (NTRS)

    Haering, Ed

    2014-01-01

    This presentation will provide general information about sonic boom mitigation technology to the public in order to supply information to potential partners and licensees. The technology is a combination of flight data, atmospheric data and terrain information implemented into a control room real time display for flight planning. This research is currently being performed and as such, any results and conclusions are ongoing.

  18. Real Time Data System (RTDS)

    NASA Technical Reports Server (NTRS)

    Heindel, Troy A.

    1991-01-01

    Information is given in viewgraph form on the Real Time Data System (RTDS). Topics covered include applications to the Space Station Freedom, the Space Shuttle flight controllers, the Mission Control Center workstations, and the Remote Manipulator Systems (RMS). Also covered are the technology gap, pacing factors, and lessons learned during research.

  19. Real Time Data System (RTDS)

    NASA Technical Reports Server (NTRS)

    Heindel, Troy A.

    1991-01-01

    Information is given in viewgraph form on the Real Time Data System (RTDS). The goals are to increase the quality of flight decision making, reduce and enhance flight controller training time, and serve as a near-operations technology test-bed. Information is given on the growth of RTDS; flight control disciplines; RTDS technology deployment in 1987-1989 and 1990-91; a functionality comparison of mainframes and workstations; and technology transfer activities.

  20. Real-time high dynamic range laser scanning microscopy

    PubMed Central

    Vinegoni, C.; Leon Swisher, C.; Fumene Feruglio, P.; Giedt, R. J.; Rousso, D. L.; Stapleton, S.; Weissleder, R.

    2016-01-01

    In conventional confocal/multiphoton fluorescence microscopy, images are typically acquired under ideal settings and after extensive optimization of parameters for a given structure or feature, often resulting in information loss from other image attributes. To overcome the problem of selective data display, we developed a new method that extends the imaging dynamic range in optical microscopy and improves the signal-to-noise ratio. Here we demonstrate how real-time and sequential high dynamic range microscopy facilitates automated three-dimensional neural segmentation. We address reconstruction and segmentation performance on samples with different size, anatomy and complexity. Finally, in vivo real-time high dynamic range imaging is also demonstrated, making the technique particularly relevant for longitudinal imaging in the presence of physiological motion and/or for quantification of in vivo fast tracer kinetics during functional imaging. PMID:27032979

  1. Real-time high dynamic range laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Vinegoni, C.; Leon Swisher, C.; Fumene Feruglio, P.; Giedt, R. J.; Rousso, D. L.; Stapleton, S.; Weissleder, R.

    2016-04-01

    In conventional confocal/multiphoton fluorescence microscopy, images are typically acquired under ideal settings and after extensive optimization of parameters for a given structure or feature, often resulting in information loss from other image attributes. To overcome the problem of selective data display, we developed a new method that extends the imaging dynamic range in optical microscopy and improves the signal-to-noise ratio. Here we demonstrate how real-time and sequential high dynamic range microscopy facilitates automated three-dimensional neural segmentation. We address reconstruction and segmentation performance on samples with different size, anatomy and complexity. Finally, in vivo real-time high dynamic range imaging is also demonstrated, making the technique particularly relevant for longitudinal imaging in the presence of physiological motion and/or for quantification of in vivo fast tracer kinetics during functional imaging.

  2. Real-time stereo generation for surgical vision during minimal invasive robotic surgery

    NASA Astrophysics Data System (ADS)

    Laddi, Amit; Bhardwaj, Vijay; Mahapatra, Prasant; Pankaj, Dinesh; Kumar, Amod

    2016-03-01

    This paper proposes a framework for 3D surgical vision for minimal invasive robotic surgery. It presents an approach for generating the three dimensional view of the in-vivo live surgical procedures from two images captured by very small sized, full resolution camera sensor rig. A pre-processing scheme is employed to enhance the image quality and equalizing the color profile of two images. Polarized Projection using interlacing two images give a smooth and strain free three dimensional view. The algorithm runs in real time with good speed at full HD resolution.

  3. Real-time ultrasound elastography

    NASA Astrophysics Data System (ADS)

    Bae, Unmin; Kim, Yongmin

    2007-03-01

    Ultrasound elastography can provide tissue stiffness information that is complementary to the anatomy and blood flow information offered by conventional ultrasound machines, but it is computationally challenging due to many time-consuming modules and a large amount of data. To facilitate real-time implementations of ultrasound elastography, we have developed new methods that can significantly reduce the computational burden of common processing components in ultrasound elastography, such as the crosscorrelation analysis and spatial filtering applied to displacement and strain estimates. Using the new correlation-based search algorithm, the computational requirement of correlation-based search does not increase with the correlation window size. For typical parameters used in ultrasound elastography, the computation in correlation-based search can be reduced by a factor of more than 30. Median filtering is often performed to suppress the spike-like noise that results from correlation-based search. For fast median filtering, we have developed a method that efficiently finds a new median value utilizing the sort result of the previous pixel. With careful mapping of the new algorithms on digital signal processors, our work has led to development of a clinical ultrasound machine supporting real-time elastography. Our methods can help real-time implementations of various applications including ultrasound elastography, which could lead to increased use of ultrasound elastography in the clinic.

  4. Three-dimensional simulations of burning thermals

    NASA Astrophysics Data System (ADS)

    Aspden, Andy; Bell, John; Woosley, Stan

    2010-11-01

    Flame ignition in type Ia supernovae (SNe Ia) leads to isolated bubbles of burning buoyant fluid. As a bubble rises due to gravity, it becomes deformed by shear instabilities and transitions to a turbulent buoyant vortex ring. Morton, Taylor and Turner (1956) introduced the entrainment assumption, which can be applied to inert thermals. In this study, we use the entrainment assumption, suitably modified to account for burning, to predict the late-time asymptotic behaviour of these turbulent buoyant vortex rings in SNe Ia. The theory is validated against three- dimensional simulations with adaptive mesh refinement at effective resolutions up to 4096^3.

  5. The current status of three-dimensional ultrasonography in gynaecology

    PubMed Central

    2016-01-01

    Ultrasonography (US) is the most recent cross-sectional imaging modality to acquire three-dimensional (3D) capabilities. The reconstruction of volumetric US data for multiplanar display took a significantly longer time to develop in comparison with computed tomography and magnetic resonance imaging. The current equipment for 3D-US is capable of producing high-resolution images in three different planes, including real-time surface-rendered images. The use of 3D-US in gynaecology was accelerated through the development of the endovaginal volume transducer, which allows the automated acquisition of volumetric US data. Although initially considered an adjunct to two-dimensional US, 3D-US is now the imaging modality of choice for the assessment of Müllerian duct anomalies and the location of intrauterine devices. PMID:26537304

  6. Real-time tritium imaging

    SciTech Connect

    Malinowski, M.E.

    1981-09-15

    A real-time image of a tritium-containing titanium film has been made by detecting the secondary electrons produced by tritium ..beta.. decay with a simple two-element electrostatic lens and microchannel plate image intensifier. The obtained image indicates that a resolution of better than 100 ..mu..m is currently obtainable and suggests that image magnification to enhance resolution should be possible.

  7. Three dimensional magnetic abacus memory

    NASA Astrophysics Data System (ADS)

    Zhang, Shilei; Zhang, Jingyan; Baker, Alexander A.; Wang, Shouguo; Yu, Guanghua; Hesjedal, Thorsten

    2014-08-01

    Stacking nonvolatile memory cells into a three-dimensional matrix represents a powerful solution for the future of magnetic memory. However, it is technologically challenging to access the data in the storage medium if large numbers of bits are stacked on top of each other. Here we introduce a new type of multilevel, nonvolatile magnetic memory concept, the magnetic abacus. Instead of storing information in individual magnetic layers, thereby having to read out each magnetic layer separately, the magnetic abacus adopts a new encoding scheme. It is inspired by the idea of second quantisation, dealing with the memory state of the entire stack simultaneously. Direct read operations are implemented by measuring the artificially engineered `quantised' Hall voltage, each representing a count of the spin-up and spin-down layers in the stack. This new memory system further allows for both flexible scaling of the system and fast communication among cells. The magnetic abacus provides a promising approach for future nonvolatile 3D magnetic random access memory.

  8. Three dimensional magnetic abacus memory

    NASA Astrophysics Data System (ADS)

    Zhang, Shilei; Zhang, Jingyan; Baker, Alexander; Wang, Shouguo; Yu, Guanghua; Hesjedal, Thorsten

    2015-03-01

    Stacking nonvolatile memory cells into a three-dimensional matrix represents a powerful solution for the future of magnetic memory. However, it is technologically challenging to access the individual data in the storage medium if large numbers of bits are stacked on top of each other. Here we introduce a new type of multilevel, nonvolatile magnetic memory concept, the magnetic abacus. Instead of storing information in individual magnetic layers, thereby having to read out each magnetic layer separately, the magnetic abacus adopts a new encoding scheme which envisages a classical abacus with the beads operated by electron spins. It is inspired by the idea of second quantization, dealing with the memory state of the entire stack simultaneously. Direct read operations are implemented by measuring the artificially engineered `quantized' Hall voltage, representing a count of the spin-up and spin-down layers in the stack. This concept of `second quantization of memory' realizes the 3D memory architecture with superior reading and operation efficiency, thus is a promising approach for future nonvolatile magnetic random access memory.

  9. Three dimensional magnetic abacus memory.

    PubMed

    Zhang, ShiLei; Zhang, JingYan; Baker, Alexander A; Wang, ShouGuo; Yu, GuangHua; Hesjedal, Thorsten

    2014-01-01

    Stacking nonvolatile memory cells into a three-dimensional matrix represents a powerful solution for the future of magnetic memory. However, it is technologically challenging to access the data in the storage medium if large numbers of bits are stacked on top of each other. Here we introduce a new type of multilevel, nonvolatile magnetic memory concept, the magnetic abacus. Instead of storing information in individual magnetic layers, thereby having to read out each magnetic layer separately, the magnetic abacus adopts a new encoding scheme. It is inspired by the idea of second quantisation, dealing with the memory state of the entire stack simultaneously. Direct read operations are implemented by measuring the artificially engineered 'quantised' Hall voltage, each representing a count of the spin-up and spin-down layers in the stack. This new memory system further allows for both flexible scaling of the system and fast communication among cells. The magnetic abacus provides a promising approach for future nonvolatile 3D magnetic random access memory. PMID:25146338

  10. True three-dimensional camera

    NASA Astrophysics Data System (ADS)

    Kornreich, Philipp; Farell, Bart

    2013-01-01

    An imager that can measure the distance from each pixel to the point on the object that is in focus at the pixel is described. This is accomplished by short photo-conducting lightguides at each pixel. In the eye the rods and cones are the fiber-like lightguides. The device uses ambient light that is only coherent in spherical shell-shaped light packets of thickness of one coherence length. Modern semiconductor technology permits the construction of lightguides shorter than a coherence length of ambient light. Each of the frequency components of the broad band light arriving at a pixel has a phase proportional to the distance from an object point to its image pixel. Light frequency components in the packet arriving at a pixel through a convex lens add constructively only if the light comes from the object point in focus at this pixel. The light in packets from all other object points cancels. Thus the pixel receives light from one object point only. The lightguide has contacts along its length. The lightguide charge carriers are generated by the light patterns. These light patterns, and thus the photocurrent, shift in response to the phase of the input signal. Thus, the photocurrent is a function of the distance from the pixel to its object point. Applications include autonomous vehicle navigation and robotic vision. Another application is a crude teleportation system consisting of a camera and a three-dimensional printer at a remote location.

  11. Construction of Three Dimensional Solutions for the Maxwell Equations

    NASA Technical Reports Server (NTRS)

    Yefet, A.; Turkel, E.

    1998-01-01

    We consider numerical solutions for the three dimensional time dependent Maxwell equations. We construct a fourth order accurate compact implicit scheme and compare it to the Yee scheme for free space in a box.

  12. Automatic blocking for complex three-dimensional configurations

    NASA Technical Reports Server (NTRS)

    Dannenhoffer, John F., III

    1995-01-01

    A new blocking technique for complex three-dimensional configurations is described. This new technique is based upon the concept of an abstraction, or squared-up representation, of the configuration and the associated grid. By allowing the user to describe blocking requirements in natural terms (such as 'wrap a grid around this leading edge' or 'make all grid lines emanating from this wall orthogonal to it'), users can quickly generate complex grids around complex configurations, while still maintaining a high level of control where desired. An added advantage of the abstraction concept is that once a blocking is defined for a class of configurations, it can be automatically applied to other configurations of the same class, making the new technique particularly well suited for the parametric variations which typically occur during design processes. Grids have been generated for a variety of real-world, two- and three-dimensional configurations. In all cases, the time required to generate the grid, given just an electronic form of the configuration, was at most a few days. Hence with this new technique, the generation of a block-structured grid is only slightly more expensive than the generation of an unstructured grid for the same configuration.

  13. Horizontal biases in rats’ use of three-dimensional space

    PubMed Central

    Jovalekic, Aleksandar; Hayman, Robin; Becares, Natalia; Reid, Harry; Thomas, George; Wilson, Jonathan; Jeffery, Kate

    2011-01-01

    Rodent spatial cognition studies allow links to be made between neural and behavioural phenomena, and much is now known about the encoding and use of horizontal space. However, the real world is three dimensional, providing cognitive challenges that have yet to be explored. Motivated by neural findings suggesting weaker encoding of vertical than horizontal space, we examined whether rats show a similar behavioural anisotropy when distributing their time freely between vertical and horizontal movements. We found that in two- or three-dimensional environments with a vertical dimension, rats showed a prioritization of horizontal over vertical movements in both foraging and detour tasks. In the foraging tasks, the animals executed more horizontal than vertical movements and adopted a “layer strategy” in which food was collected from one horizontal level before moving to the next. In the detour tasks, rats preferred the routes that allowed them to execute the horizontal leg first. We suggest three possible reasons for this behavioural bias. First, as suggested by Grobety and Schenk [5], it allows minimisation of energy expenditure, inasmuch as costly vertical movements are minimised. Second, it may be a manifestation of the temporal discounting of effort, in which animals value delayed effort as less costly than immediate effort. Finally, it may be that at the neural level rats encode the vertical dimension less precisely, and thus prefer to bias their movements in the more accurately encoded horizontal dimension. We suggest that all three factors are related, and all play a part. PMID:21419172

  14. Abstraction Planning in Real Time

    NASA Technical Reports Server (NTRS)

    Washington, Richard

    1994-01-01

    When a planning agent works in a complex, real-world domain, it is unable to plan for and store all possible contingencies and problem situations ahead of time. The agent needs to be able to fall back on an ability to construct plans at run time under time constraints. This thesis presents a method for planning at run time that incrementally builds up plans at multiple levels of abstraction. The plans are continually updated by information from the world, allowing the planner to adjust its plan to a changing world during the planning process. All the information is represented over intervals of time, allowing the planner to reason about durations, deadlines, and delays within its plan. In addition to the method, the thesis presents a formal model of the planning process and uses the model to investigate planning strategies. The method has been implemented, and experiments have been run to validate the overall approach and the theoretical model.

  15. Real-time flutter analysis

    NASA Technical Reports Server (NTRS)

    Walker, R.; Gupta, N.

    1984-01-01

    The important algorithm issues necessary to achieve a real time flutter monitoring system; namely, the guidelines for choosing appropriate model forms, reduction of the parameter convergence transient, handling multiple modes, the effect of over parameterization, and estimate accuracy predictions, both online and for experiment design are addressed. An approach for efficiently computing continuous-time flutter parameter Cramer-Rao estimate error bounds were developed. This enables a convincing comparison of theoretical and simulation results, as well as offline studies in preparation for a flight test. Theoretical predictions, simulation and flight test results from the NASA Drones for Aerodynamic and Structural Test (DAST) Program are compared.

  16. Cosmic Atlas: A Real-Time Universe Simulation

    NASA Astrophysics Data System (ADS)

    Yu, K. C.; Jenkins, N. E.

    2004-05-01

    Cosmic Atlas is a software program produced at the Denver Museum of Nature & Science to generate real-time digital content for the Museum's Gates Planetarium. Created by in-house staff, Cosmic Atlas is designed to be scientifically accurate, flexible, easily updated to stay current with new discoveries, and portable to multiple platforms. It is currently developed using desktop computers running a Linux OS, and is also installed on a multi-graphics pipe SGI visualization computer running the IRIX OS in the Gates Planetarium. The software can be used in real-time presentations via traditional ``star talks'' and classes, but can also be used to devise flightpaths, perform timeline-based editing, play back flightpaths in real-time, and save out image renders for creating video files to be shown on additional playback systems. The first version of the program is meant to replicate the functionality of a traditional optical-mechanical star ball, and hence creates a replica of the night time sky, with constellations, deep sky objects, and didactic information and grids. The Solar System is a realistic, three-dimensional, navigable simulation, updated with the latest moon and minor planet discoveries, and with motions over time determined by a customized orrery. Additional modules can show traditional astronomical imagery, including an application for loading in FITS files to create three-color composites. A three-dimensional model of the Milky Way is in development, populated with HIPPARCOS stars for the local galactic neighborhood, and with molecular clouds constructed from large-scale CO survey data; more distant regions are filled with statistically generated stellar and interstellar medium distributions.

  17. Three-dimensional image reconstruction in capsule endoscopy

    PubMed Central

    Koulaouzidis, Anastasios; Karargyris, Alexandros

    2012-01-01

    To date, limited research has been carried out in developing methods and materials that offer three-dimensional (3-D) representation of the digestive tract. In the field of capsule endoscopy (CE), hardware approaches have been developed that provide real time both 3-D information and texture using an infrared projector and a complementary metal oxide semiconductor camera. The major drawbacks of this system are its size, power consumption and packaging issues. A software approach to approximate a 3-D representation of digestive tract surface utilising current CE technology has been proposed. The algorithm utilizes the Shape from Shading technique and seem to provide promising results for polypoid structures and angioectasias. Further clinical evaluation is currently under way. PMID:22919239

  18. Abstraction Planning in Real Time

    NASA Technical Reports Server (NTRS)

    Washington, R.

    1994-01-01

    When a planning agent works in a complex, real-world domain, it is unable to plan for and store all possible contingencies and problem situations ahead of time. This thesis presents a method for planning a run time that incrementally builds up plans at multiple levels of abstraction. The plans are continually updated by information from the world, allowing the planner to adjust its plan to a changing world during the planning process. All the information is represented over intervals of time, allowing the planner to reason about durations, deadlines, and delays within its plan. In addition to the method, the thesis presents a formal model of the planning process and uses the model to investigate planning strategies.

  19. Real-time streamflow conditions

    USGS Publications Warehouse

    Graczyk, David J.; Gebert, Warren A.

    1996-01-01

    Would you like to know streamflow conditions before you go fishing in Wisconsin or in more distant locations? Real-time streamflow data throughout Wisconsin and the United States are available on the Internet from the U.S. Geological Survey. You can see if the stream you are interested in fishing is high due to recent rain or low because of an extended dry spell. Flow conditions at more than 100 stream-gaging stations located throughout Wisconsin can be viewed by accessing the Wisconsin District Home Page at: http://wwwdwimdn.er.usgs.gov

  20. Real time infrared aerosol analyzer

    DOEpatents

    Johnson, Stanley A.; Reedy, Gerald T.; Kumar, Romesh

    1990-01-01

    Apparatus for analyzing aerosols in essentially real time includes a virtual impactor which separates coarse particles from fine and ultrafine particles in an aerosol sample. The coarse and ultrafine particles are captured in PTFE filters, and the fine particles impact onto an internal light reflection element. The composition and quantity of the particles on the PTFE filter and on the internal reflection element are measured by alternately passing infrared light through the filter and the internal light reflection element, and analyzing the light through infrared spectrophotometry to identify the particles in the sample.

  1. Three-dimensional television: a broadcaster's perspective

    NASA Astrophysics Data System (ADS)

    Jolly, S. J. E.; Armstrong, M.; Salmon, R. A.

    2009-02-01

    The recent resurgence of interest in the stereoscopic cinema and the increasing availability to the consumer of stereoscopic televisions and computer displays are leading broadcasters to consider, once again, the feasibility of stereoscopic broadcasting. High Definition Television is now widely deployed, and the R&D departments of broadcasters and consumer electronics manufacturers are starting to plan future enhancements to the experience of television. Improving the perception of depth via stereoscopy is a strong candidate technology. In this paper we will consider the challenges associated with the production, transmission and display of different forms of "three-dimensional" television. We will explore options available to a broadcaster wishing to start a 3D service using the technologies available at the present time, and consider how they could be improved to enable many more television programmes to be recorded and transmitted in a 3D-compatible form, paying particular attention to scenarios such as live broadcasting, where the workflows developed for the stereoscopic cinema are inapplicable. We will also consider the opportunities available for broadcasters to reach audiences with "three-dimensional" content via other media in the near future: for example, distributing content via the existing stereoscopic cinema network, or over the Internet to owners of stereoscopic computer displays.

  2. Novel Algorithm for Polar and Spherical Fourier Analysis on Two and Three Dimensional Images

    NASA Astrophysics Data System (ADS)

    Yang, Zhuo; Kamata, Sei-Ichiro

    Polar and Spherical Fourier analysis can be used to extract rotation invariant features for image retrieval and pattern recognition tasks. They are demonstrated to show superiorities comparing with other methods on describing rotation invariant features of two and three dimensional images. Based on mathematical properties of trigonometric functions and associated Legendre polynomials, fast algorithms are proposed for multimedia applications like real time systems and large multimedia databases in order to increase the computation speed. The symmetric points are computed simultaneously. Inspired by relative prime number theory, systematic analysis are given in this paper. Novel algorithm is deduced that provide even faster speed. Proposed method are 9-15% faster than previous work. The experimental results on two and three dimensional images are given to illustrate the effectiveness of the proposed method. Multimedia signal processing applications that need real time polar and spherical Fourier analysis can be benefit from this work.

  3. Real-time face tracking

    NASA Astrophysics Data System (ADS)

    Liang, Yufeng; Wilder, Joseph

    1998-10-01

    A real-time face tracker is presented in this paper. The system has achieved 15 frames/second tracking using a Pentium 200 PC with a Datacube MaxPCI image processing board and a Panasonic RGB color camera. It tracks human faces in the camera's field of view while people move freely. A stochastic model to characterize the skin color distribution of human skin is used to segment the face and other skin areas from the background. Median filtering is then used to clean up the background noise. Geometric constraints are applied to the segmented image to extract the face from the background. To reduce computation and achieve real-time tracking, 1D projections (horizontal and vertical) of the image are analyzed instead of the 2D image. Run-length- encoding and frequency domain analysis algorithms are used to separate faces from other skin-like blobs. The system is robust to illumination intensity variations and different skin colors. It can be applied to many human-computer interaction applications such as sound locating, lip- reading, gaze tracking and face recognition.

  4. Three-dimensional boundary layers approaching separation

    NASA Technical Reports Server (NTRS)

    Williams, J. C., III

    1976-01-01

    The theory of semi-similar solutions of the laminar boundary layer equations is applied to several flows in which the boundary layer approaches a three-dimensional separation line. The solutions obtained are used to deduce the nature of three-dimensional separation. It is shown that in these cases separation is of the "ordinary" type. A solution is also presented for a case in which a vortex is embedded within the three-dimensional boundary layer.

  5. RADIAL STELLAR PULSATION AND THREE-DIMENSIONAL CONVECTION. IV. FULL AMPLITUDE THREE-DIMENSIONAL SOLUTIONS

    SciTech Connect

    Geroux, Christopher M.; Deupree, Robert G.

    2015-02-10

    Three-dimensional hydrodynamic simulations of full amplitude RR Lyrae stars have been computed for several models across the instability strip. The three-dimensional nature of the calculations allows convection to be treated without reference to a phenomenological approach such as the local mixing length theory. Specifically, the time-dependent interaction of large-scale eddies and radial pulsation is controlled by conservation laws, while the effects of smaller convective eddies are simulated by an eddy viscosity model. The light amplitudes for these calculations are quite similar to those of our previous two-dimensional calculations in the middle of the instability strip, but somewhat lower near the red edge, the fundamental blue edge, and for the one first overtone model we computed. The time-dependent interaction between the radial pulsation and the convective energy transport is essentially the same in three dimensions as it is in two dimensions. There are some differences between the light curves of the two- and three-dimensional simulations, particularly during decreasing light. Reasons for the differences, both numerical and physical, are explored.

  6. Real-time flood forecasting

    USGS Publications Warehouse

    Lai, C.; Tsay, T.-K.; Chien, C.-H.; Wu, I.-L.

    2009-01-01

    Researchers at the Hydroinformatic Research and Development Team (HIRDT) of the National Taiwan University undertook a project to create a real time flood forecasting model, with an aim to predict the current in the Tamsui River Basin. The model was designed based on deterministic approach with mathematic modeling of complex phenomenon, and specific parameter values operated to produce a discrete result. The project also devised a rainfall-stage model that relates the rate of rainfall upland directly to the change of the state of river, and is further related to another typhoon-rainfall model. The geographic information system (GIS) data, based on precise contour model of the terrain, estimate the regions that were perilous to flooding. The HIRDT, in response to the project's progress, also devoted their application of a deterministic model to unsteady flow of thermodynamics to help predict river authorities issue timely warnings and take other emergency measures.

  7. Present development of TRANSFUSION, a novel time-dependent three-dimensional finite-element neutron and gamma diffusion code for the analysis of pulsed-neutron oil-well logs

    SciTech Connect

    De Raedt, C.M.; Ruan, D.

    1994-12-31

    The novel code TRANSFUSION is being developed with a view to analysing borehole logs in the field of oil exploration and production. TRANSFUSION describes the time-dependent neutron and gamma populations in the logging tool and the surrounding formation resulting from bursts of high energy neutrons by providing first-order solutions to the Boltzmann transport equation. In particular, the gamma responses in the near and the far detectors housed in the logging tool are calculated. TRANSFUSION was developed from the ANSWERS steady-state (three-dimensional) finite-element neutron and gamma diffusion code FENDER by extending it to become time-dependent. The code is an attractive alternative to the generally used rigorous Monte Carlo methods, being as user friendly but less time-consuming while remaining sufficiently accurate.

  8. An ensemble Kalman filter approach to identify the hydraulic conductivity spatial distribution from electrical resistivity tomography time-lapse monitoring of three-dimensional tracer test experiments

    NASA Astrophysics Data System (ADS)

    Camporese, M.; Cassiani, G.; Deiana, R.; Perri, M. T.; Salandin, P.

    2012-04-01

    An approach based on the Lagrangian formulation of transport and the ensemble Kalman filter (EnKF) is applied to assess the spatial distribution of hydraulic conductivity K by assimilating time-lapse cross-hole electrical resistivity tomography (ERT) images generated for a synthetic tracer test in a heterogeneous aquifer. Assuming that the solute spreads as a passive tracer, for high Peclet numbers the spatial moments of the evolving plume are dominated by the spatial distribution of the hydraulic conductivity. The assimilation of the electrical conductivity 4D images allows updating both the hydrological state in terms of solute concentration and the spatial distribution of K. Thus, delineation of the tracer plume and estimation of the aquifer heterogeneity at the local scale can be achieved at the same time by means of this interpretation of time-lapse electrical images from tracer tests. We assess the impact on the performance of the hydrological inversion of the uncertainty inherently affecting ERT inversions in terms of tracer concentration and the choice of the prior statistics of K. The results show that realistic ERT images can be integrated into a hydrological model even within an uncoupled inverse modeling framework, the reconstruction of the hydraulic conductivity spatial distribution being satisfactory in the portion of the domain directly covered by the passage of the tracer. Aside from the issues commonly affecting inverse models, the proposed approach is subject to the problem of the filter inbreeding and the retrieval performance is sensitive to the choice of K prior geostatistical parameters.

  9. Autonomous Real Time Requirements Tracing

    NASA Technical Reports Server (NTRS)

    Plattsmier, George I.; Stetson, Howard K.

    2014-01-01

    One of the more challenging aspects of software development is the ability to verify and validate the functional software requirements dictated by the Software Requirements Specification (SRS) and the Software Detail Design (SDD). Insuring the software has achieved the intended requirements is the responsibility of the Software Quality team and the Software Test team. The utilization of Timeliner-TLX(sup TM) Auto-Procedures for relocating ground operations positions to ISS automated on-board operations has begun the transition that would be required for manned deep space missions with minimal crew requirements. This transition also moves the auto-procedures from the procedure realm into the flight software arena and as such the operational requirements and testing will be more structured and rigorous. The autoprocedures would be required to meet NASA software standards as specified in the Software Safety Standard (NASASTD- 8719), the Software Engineering Requirements (NPR 7150), the Software Assurance Standard (NASA-STD-8739) and also the Human Rating Requirements (NPR-8705). The Autonomous Fluid Transfer System (AFTS) test-bed utilizes the Timeliner-TLX(sup TM) Language for development of autonomous command and control software. The Timeliner- TLX(sup TM) system has the unique feature of providing the current line of the statement in execution during real-time execution of the software. The feature of execution line number internal reporting unlocks the capability of monitoring the execution autonomously by use of a companion Timeliner-TLX(sup TM) sequence as the line number reporting is embedded inside the Timeliner-TLX(sup TM) execution engine. This negates I/O processing of this type data as the line number status of executing sequences is built-in as a function reference. This paper will outline the design and capabilities of the AFTS Autonomous Requirements Tracker, which traces and logs SRS requirements as they are being met during real-time execution of the

  10. Autonomous Real Time Requirements Tracing

    NASA Technical Reports Server (NTRS)

    Plattsmier, George; Stetson, Howard

    2014-01-01

    One of the more challenging aspects of software development is the ability to verify and validate the functional software requirements dictated by the Software Requirements Specification (SRS) and the Software Detail Design (SDD). Insuring the software has achieved the intended requirements is the responsibility of the Software Quality team and the Software Test team. The utilization of Timeliner-TLX(sup TM) Auto- Procedures for relocating ground operations positions to ISS automated on-board operations has begun the transition that would be required for manned deep space missions with minimal crew requirements. This transition also moves the auto-procedures from the procedure realm into the flight software arena and as such the operational requirements and testing will be more structured and rigorous. The autoprocedures would be required to meet NASA software standards as specified in the Software Safety Standard (NASASTD- 8719), the Software Engineering Requirements (NPR 7150), the Software Assurance Standard (NASA-STD-8739) and also the Human Rating Requirements (NPR-8705). The Autonomous Fluid Transfer System (AFTS) test-bed utilizes the Timeliner-TLX(sup TM) Language for development of autonomous command and control software. The Timeliner-TLX(sup TM) system has the unique feature of providing the current line of the statement in execution during real-time execution of the software. The feature of execution line number internal reporting unlocks the capability of monitoring the execution autonomously by use of a companion Timeliner-TLX(sup TM) sequence as the line number reporting is embedded inside the Timeliner-TLX(sup TM) execution engine. This negates I/O processing of this type data as the line number status of executing sequences is built-in as a function reference. This paper will outline the design and capabilities of the AFTS Autonomous Requirements Tracker, which traces and logs SRS requirements as they are being met during real-time execution of the

  11. Two-dimensional and three-dimensional dynamic imaging of live biofilms in a microchannel by time-of-flight secondary ion mass spectrometry

    SciTech Connect

    Hua, Xin; Marshall, Matthew J.; Xiong, Yijia; Ma, Xiang; Zhou, Yufan; Tucker, Abigail E.; Zhu, Zihua; Liu, Songqin; Yu, Xiao-Ying

    2015-05-01

    A vacuum compatible microfluidic reactor, SALVI (System for Analysis at the Liquid Vacuum Interface) was employed for in situ chemical imaging of live biofilms using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Depth profiling by sputtering materials in sequential layers resulted in live biofilm spatial chemical mapping. 2D images were reconstructed to report the first 3D images of hydrated biofilm elucidating spatial and chemical heterogeneity. 2D image principal component analysis (PCA) was conducted among biofilms at different locations in the microchannel. Our approach directly visualized spatial and chemical heterogeneity within the living biofilm by dynamic liquid ToF-SIMS.

  12. Diffuser-aided diffuse optical imaging for breast tumor: a feasibility study based on time-resolved three-dimensional Monte Carlo modeling.

    PubMed

    Chuang, Ching-Cheng; Lee, Chia-Yen; Chen, Chung-Ming; Hsieh, Yao-Sheng; Liu, Tsan-Chi; Sun, Chia-Wei

    2012-05-01

    This study proposed diffuser-aided diffuse optical imaging (DADOI) as a new approach to improve the performance of the conventional diffuse optical tomography (DOT) approach for breast imaging. The 3-D breast model for Monte Carlo simulation is remodeled from clinical MRI image. The modified Beer-Lambert's law is adopted with the DADOI approach to substitute the complex algorithms of inverse problem for mapping of spatial distribution, and the depth information is obtained based on the time-of-flight estimation. The simulation results demonstrate that the time-resolved Monte Carlo method can be capable of performing source-detector separations analysis. The dynamics of photon migration with various source-detector separations are analyzed for the characterization of breast tissue and estimation of optode arrangement. The source-detector separations should be less than 4 cm for breast imaging in DOT system. Meanwhile, the feasibility of DADOI was manifested in this study. In the results, DADOI approach can provide better imaging contrast and faster imaging than conventional DOT measurement. The DADOI approach possesses great potential to detect the breast tumor in early stage and chemotherapy monitoring that implies a good feasibility for clinical application. PMID:22394571

  13. Radiation boundary conditions for the numerical solution of the three-dimensional time-dependent Schroedinger equation with a localized interaction

    SciTech Connect

    Heinen, M.; Kull, H.-J.

    2009-05-15

    Exact radiation boundary conditions on the surface of a sphere are presented for the single-particle time-dependent Schroedinger equation with a localized interaction. With these boundary conditions, numerical computations of spatially unbounded outgoing wave solutions can be restricted to the finite volume of a sphere. The boundary conditions are expressed in terms of the free-particle Green's function for the outside region. The Green's function is analytically calculated by an expansion in spherical harmonics and by the method of Laplace transformation. For each harmonic number a discrete boundary condition between the function values at adjacent radial grid points is obtained. The numerical method is applied to quantum tunneling through a spherically symmetric potential barrier with different angular-momentum quantum numbers l. Calculations for l=0 are compared to exact theoretical results.

  14. Parallel computation of unsteady, three-dimensional, chemically reacting, nonequilibrium flow using a time-split finite-volume method on the Illiac IV

    NASA Technical Reports Server (NTRS)

    Reinhardt, W. A.

    1977-01-01

    A description is presented of the split finite-volume method which is a viable numerical procedure for performing with the aid of a modern special purpose vector computer numerical simulation studies of complicated flow fields, including chemical reactions, about geometrically complex bodies. Such numerical studies are needed for the development of atmospheric entry vehicles such as the space shuttle. The equations which are approximated are quite general and can be used in studies of combustion, pollution, and other chemically reacting flow phenomena, where convective transport effects dominate the influence of radiative, viscous, and other transport mechanisms. The shock perturbed flow about a shuttle orbiter flying at a large angle of attack during atmospheric entry is illustrated. The method uses a time splitting of the convection differencing operator to achieve efficient data management.

  15. Receptivity of a laminar boundary layer to the interaction of a three-dimensional roughness element with time-harmonic free-stream disturbances

    NASA Technical Reports Server (NTRS)

    Tadjfar, M.; Bodonyi, R. J.

    1992-01-01

    Receptivity of a laminar boundary layer to the interaction of time-harmonic free-stream disturbances with a 3D roughness element is studied. The 3D nonlinear triple-deck equations are solved numerically to provide the basic steady-state motion. At high Reynolds numbers, the governing equations for the unsteady motion are the unsteady linearized 3D triple-deck equations. These equations can only be solved numerically. In the absence of any roughness element, the free-stream disturbances, to the first order, produce the classical Stokes flow, in the thin Stokes layer near the wall (on the order of our lower deck). However, with the introduction of a small 3D roughness element, the interaction between the hump and the Stokes flow introduces a spectrum of all spatial disturbances inside the boundary layer.

  16. Three-dimensional determination of the center of the Watts datum relative to the lunar center of mass. [photoelectric occultations and laser time delay measurements

    NASA Technical Reports Server (NTRS)

    Mulholland, J. D.

    1977-01-01

    The location of the origin of the Watts datum for the marginal zone of the moon is determined using results of 2770 photoelectric occultation observations obtained over an 18-yr period in combination with 1787 laser time-delay measurements carried out over a five-year period. The lunar ephemeris employed is an experimental one developed from a much shorter span of laser observations. The final solution is obtained by adopting LURE2 parameters and correcting 19 lunar orbital, solar orbital, and coordinate-system parameters. The offsets for the center of the Watts datum are found to be approximately +6.8 km for x1, -2.5 km for x2, and +0.06 km for x3 with respect to the lunar principal axes of inertia.

  17. Three-Dimensional Image of Cleavage Bodies in Nuclei Is Configured Using Gas Cluster Ion Beam with Time-of-Flight Secondary Ion Mass Spectrometry.

    PubMed

    Masaki, Noritaka; Ishizaki, Itsuko; Hayasaka, Takahiro; Fisher, Gregory L; Sanada, Noriaki; Yokota, Hideo; Setou, Mitsutoshi

    2015-01-01

    Structural variations of DNA in nuclei are deeply related with development, aging, and diseases through transcriptional regulation. In order to bare cross sections of samples maintaining sub-micron structures, an Ar2500(+)-gas cluster ion beam (GCIB) sputter was recently engineered. By introducing GCIB sputter to time-of-flight secondary ion mass spectrometry (TOF-SIMS), we analyzed the 3D configuration and chemical composition of subnuclear structures of pyramidal cells in the CA2 region in mouse brain hippocampus. Depth profiles of chemicals were analyzed as 3D distributions by combining topographic analyses. Signals corresponding to anions such as CN(-) and PO3(-) were distributed characteristically in the shape of cell organelles. CN(-) signals overlapped DAPI fluorescence signals corresponding to nuclei. The clusters shown by PO3(-) and those of adenine ions were colocalized inside nuclei revealed by the 3D reconstruction. Taking into account their size and their number in each nucleus, those clusters could be in the cleavage bodies, which are a kind of intranuclear structure. PMID:25961407

  18. Three-Dimensional Image of Cleavage Bodies in Nuclei Is Configured Using Gas Cluster Ion Beam with Time-of-Flight Secondary Ion Mass Spectrometry

    PubMed Central

    Masaki, Noritaka; Ishizaki, Itsuko; Hayasaka, Takahiro; Fisher, Gregory L.; Sanada, Noriaki; Yokota, Hideo; Setou, Mitsutoshi

    2015-01-01

    Structural variations of DNA in nuclei are deeply related with development, aging, and diseases through transcriptional regulation. In order to bare cross sections of samples maintaining sub-micron structures, an Ar2500+-gas cluster ion beam (GCIB) sputter was recently engineered. By introducing GCIB sputter to time-of-flight secondary ion mass spectrometry (TOF-SIMS), we analyzed the 3D configuration and chemical composition of subnuclear structures of pyramidal cells in the CA2 region in mouse brain hippocampus. Depth profiles of chemicals were analyzed as 3D distributions by combining topographic analyses. Signals corresponding to anions such as CN− and PO3− were distributed characteristically in the shape of cell organelles. CN− signals overlapped DAPI fluorescence signals corresponding to nuclei. The clusters shown by PO3− and those of adenine ions were colocalized inside nuclei revealed by the 3D reconstruction. Taking into account their size and their number in each nucleus, those clusters could be in the cleavage bodies, which are a kind of intranuclear structure. PMID:25961407

  19. A Space-Time Conservation Element and Solution Element Method for Solving the Two- and Three-Dimensional Unsteady Euler Equations Using Quadrilateral and Hexahedral Meshes

    NASA Technical Reports Server (NTRS)

    Zhang, Zeng-Chan; Yu, S. T. John; Chang, Sin-Chung; Jorgenson, Philip (Technical Monitor)

    2001-01-01

    In this paper, we report a version of the Space-Time Conservation Element and Solution Element (CE/SE) Method in which the 2D and 3D unsteady Euler equations are simulated using structured or unstructured quadrilateral and hexahedral meshes, respectively. In the present method, mesh values of flow variables and their spatial derivatives are treated as independent unknowns to be solved for. At each mesh point, the value of a flow variable is obtained by imposing a flux conservation condition. On the other hand, the spatial derivatives are evaluated using a finite-difference/weighted-average procedure. Note that the present extension retains many key advantages of the original CE/SE method which uses triangular and tetrahedral meshes, respectively, for its 2D and 3D applications. These advantages include efficient parallel computing ease of implementing non-reflecting boundary conditions, high-fidelity resolution of shocks and waves, and a genuinely multidimensional formulation without using a dimensional-splitting approach. In particular, because Riemann solvers, the cornerstones of the Godunov-type upwind schemes, are not needed to capture shocks, the computational logic of the present method is considerably simpler. To demonstrate the capability of the present method, numerical results are presented for several benchmark problems including oblique shock reflection, supersonic flow over a wedge, and a 3D detonation flow.

  20. Real-time automatic registration in optical surgical navigation

    NASA Astrophysics Data System (ADS)

    Lin, Qinyong; Yang, Rongqian; Cai, Ken; Si, Xuan; Chen, Xiuwen; Wu, Xiaoming

    2016-05-01

    An image-guided surgical navigation system requires the improvement of the patient-to-image registration time to enhance the convenience of the registration procedure. A critical step in achieving this aim is performing a fully automatic patient-to-image registration. This study reports on a design of custom fiducial markers and the performance of a real-time automatic patient-to-image registration method using these markers on the basis of an optical tracking system for rigid anatomy. The custom fiducial markers are designed to be automatically localized in both patient and image spaces. An automatic localization method is performed by registering a point cloud sampled from the three dimensional (3D) pedestal model surface of a fiducial marker to each pedestal of fiducial markers searched in image space. A head phantom is constructed to estimate the performance of the real-time automatic registration method under four fiducial configurations. The head phantom experimental results demonstrate that the real-time automatic registration method is more convenient, rapid, and accurate than the manual method. The time required for each registration is approximately 0.1 s. The automatic localization method precisely localizes the fiducial markers in image space. The averaged target registration error for the four configurations is approximately 0.7 mm. The automatic registration performance is independent of the positions relative to the tracking system and the movement of the patient during the operation.

  1. Three-dimensional joint transform correlator cryptosystem.

    PubMed

    Zea, Alejandro Velez; Barrera Ramirez, John Fredy; Torroba, Roberto

    2016-02-01

    We introduce for the first time, to the best of our knowledge, a three-dimensional experimental joint transform correlator (JTC) cryptosystem allowing the encryption of information for any 3D object, and as an additional novel feature, a second 3D object plays the role of the encoding key. While the JTC architecture is normally used to process 2D data, in this work, we envisage a technique that allows the use of this architecture to protect 3D data. The encrypted object information is contained in the joint power spectrum. We register the key object as a digital off-axis Fourier hologram. The encryption procedure is done optically, while the decryption is carried out by means of a virtual optical system, allowing for flexible implementation of the proposal. We present experimental results to demonstrate the validity and feasibility of the method. PMID:26907433

  2. Three-dimensional hologram display system

    NASA Technical Reports Server (NTRS)

    Mintz, Frederick (Inventor); Chao, Tien-Hsin (Inventor); Bryant, Nevin (Inventor); Tsou, Peter (Inventor)

    2009-01-01

    The present invention relates to a three-dimensional (3D) hologram display system. The 3D hologram display system includes a projector device for projecting an image upon a display medium to form a 3D hologram. The 3D hologram is formed such that a viewer can view the holographic image from multiple angles up to 360 degrees. Multiple display media are described, namely a spinning diffusive screen, a circular diffuser screen, and an aerogel. The spinning diffusive screen utilizes spatial light modulators to control the image such that the 3D image is displayed on the rotating screen in a time-multiplexing manner. The circular diffuser screen includes multiple, simultaneously-operated projectors to project the image onto the circular diffuser screen from a plurality of locations, thereby forming the 3D image. The aerogel can use the projection device described as applicable to either the spinning diffusive screen or the circular diffuser screen.

  3. Three-Dimensional Gear Crack Propagation Studies

    NASA Technical Reports Server (NTRS)

    Lewicki, David G.; Sane, Ashok D.; Drago, Raymond J.; Wawrzynek, Paul A.

    1998-01-01

    Three-dimensional crack growth simulation was performed on a split-tooth gear design using boundary element modeling and linear elastic fracture mechanics. Initial cracks in the fillet of the teeth produced stress intensity factors of greater magnitude (and thus, greater crack growth rates) than those in the root or groove areas of the teeth. Crack growth simulation was performed on a case study to evaluate crack propagation paths. Tooth fracture was predicted from the crack growth simulation for an initial crack in the tooth fillet region. Tooth loads on the uncracked mesh of the split-tooth design were up to five times greater than those on the cracked mesh if equal deflections of the cracked and uncracked teeth were considered. Predicted crack shapes as well as crack propagation life are presented based on calculated stress intensity factors, mixed-mode crack propagation trajectory theories, and fatigue crack growth theories.

  4. Three dimensional thrust chamber life prediction

    NASA Technical Reports Server (NTRS)

    Armstrong, W. H.; Brogren, E. W.

    1976-01-01

    A study was performed to analytically determine the cyclic thermomechanical behavior and fatigue life of three configurations of a Plug Nozzle Thrust Chamber. This thrust chamber is a test model which represents the current trend in nozzle design calling for high performance coupled with weight and volume limitations as well as extended life for reusability. The study involved the use of different materials and material combinations to evaluate their application to the problem of low-cycle fatigue in the thrust chamber. The thermal and structural analyses were carried out on a three-dimensional basis. Results are presented which show plots of continuous temperature histories and temperature distributions at selected times during the operating cycle of the thrust chamber. Computed structural data show critical regions for low-cycle fatigue and the histories of strain within the regions for each operation cycle.

  5. Automatic three-dimensional registration of intra-vascular optical coherence tomography images for the clinical evaluation of stent implantation over time

    NASA Astrophysics Data System (ADS)

    Ughi, Giovanni J.; Adriaenssens, Tom; Larsson, Matilda; Dubois, Christophe; Sinnaeve, Peter; Coosemans, Mark; Desmet, Walter; D'hooghe, Jan

    2012-01-01

    In the last decade a large number of new intracoronary devices (i.e. drug-eluting stents, DES) have been developed to reduce the risks related to bare metal stent (BMS) implantation. The use of this new generation of DES has been shown to substantially reduce, compared with BMS, the occurrence of restenosis and recurrent ischemia that would necessitate a second revascularization procedure. Nevertheless, safety issues on the use of DES persist and full understanding of mechanisms of adverse clinical events is still a matter of concern and debate. Intravascular Optical Coherence Tomography (IV-OCT) is an imaging technique able to visualize the microstructure of blood vessels with an axial resolution <20 μm. Due to its very high spatial resolution, it enables detailed in-vivo assessment of implanted devices and vessel wall. Currently, the aim of several major clinical trials is to observe and quantify the vessel response to DES implantation over time. However, image analysis is currently performed manually and corresponding images, belonging to different IV-OCT acquisitions, can only be matched through a very labor intensive and subjective procedure. The aim of this study is to develop and validate a new methodology for the automatic registration of IV-OCT datasets on an image level. Hereto, we propose a landmark based rigid registration method exploiting the metallic stent framework as a feature. Such a tool would provide a better understanding of the behavior of different intracoronary devices in-vivo, giving unique insights about vessel pathophysiology and performance of new generation of intracoronary devices and different drugs.

  6. Ordered three-dimensional interconnected nanoarchitectures in anodic porous alumina

    PubMed Central

    Martín, Jaime; Martín-González, Marisol; Fernández, Jose Francisco; Caballero-Calero, Olga

    2014-01-01

    Three-dimensional nanostructures combine properties of nanoscale materials with the advantages of being macro-sized pieces when the time comes to manipulate, measure their properties, or make a device. However, the amount of compounds with the ability to self-organize in ordered three-dimensional nanostructures is limited. Therefore, template-based fabrication strategies become the key approach towards three-dimensional nanostructures. Here we report the simple fabrication of a template based on anodic aluminum oxide, having a well-defined, ordered, tunable, homogeneous 3D nanotubular network in the sub 100 nm range. The three-dimensional templates are then employed to achieve three-dimensional, ordered nanowire-networks in Bi2Te3 and polystyrene. Lastly, we demonstrate the photonic crystal behavior of both the template and the polystyrene three-dimensional nanostructure. Our approach may establish the foundations for future high-throughput, cheap, photonic materials and devices made of simple commodity plastics, metals, and semiconductors. PMID:25342247

  7. MISR Level 1 Near Real Time Products

    Atmospheric Science Data Center

    2014-09-15

    Level 1 Near Real Time The MISR Near Real Time Level 1 data products consist of radiance measurements organized in 10-50 minute ... (off-nadir) cameras. The remaining channels are sampled at 1.1 km. ...

  8. Advanced Three-Dimensional Display System

    NASA Technical Reports Server (NTRS)

    Geng, Jason

    2005-01-01

    A desktop-scale, computer-controlled display system, initially developed for NASA and now known as the VolumeViewer(TradeMark), generates three-dimensional (3D) images of 3D objects in a display volume. This system differs fundamentally from stereoscopic and holographic display systems: The images generated by this system are truly 3D in that they can be viewed from almost any angle, without the aid of special eyeglasses. It is possible to walk around the system while gazing at its display volume to see a displayed object from a changing perspective, and multiple observers standing at different positions around the display can view the object simultaneously from their individual perspectives, as though the displayed object were a real 3D object. At the time of writing this article, only partial information on the design and principle of operation of the system was available. It is known that the system includes a high-speed, silicon-backplane, ferroelectric-liquid-crystal spatial light modulator (SLM), multiple high-power lasers for projecting images in multiple colors, a rotating helix that serves as a moving screen for displaying voxels [volume cells or volume elements, in analogy to pixels (picture cells or picture elements) in two-dimensional (2D) images], and a host computer. The rotating helix and its motor drive are the only moving parts. Under control by the host computer, a stream of 2D image patterns is generated on the SLM and projected through optics onto the surface of the rotating helix. The system utilizes a parallel pixel/voxel-addressing scheme: All the pixels of the 2D pattern on the SLM are addressed simultaneously by laser beams. This parallel addressing scheme overcomes the difficulty of achieving both high resolution and a high frame rate in a raster scanning or serial addressing scheme. It has been reported that the structure of the system is simple and easy to build, that the optical design and alignment are not difficult, and that the

  9. Research on transformation and optimization of large scale 3D modeling for real time rendering

    NASA Astrophysics Data System (ADS)

    Yan, Hu; Yang, Yongchao; Zhao, Gang; He, Bin; Shen, Guosheng

    2011-12-01

    During the simulation process of real-time three-dimensional scene, the popular modeling software and the real-time rendering platform are not compatible. The common solution is to create three-dimensional scene model by using modeling software and then transform the format supported by rendering platform. This paper takes digital campus scene simulation as an example, analyzes and solves the problems of surface loss; texture distortion and loss; model flicker and so on during the transformation from 3Ds Max to MultiGen Creator. Besides, it proposes the optimization strategy of model which is transformed. The operation results show that this strategy is a good solution to all kinds of problems existing in transformation and it can speed up the rendering speed of the model.

  10. Three-dimensional vortex structures in a rotating dipolar Bose–Einstein condensate

    NASA Astrophysics Data System (ADS)

    Kishor Kumar, Ramavarmaraja; Sriraman, Thangarasu; Fabrelli, Henrique; Muruganandam, Paulsamy; Gammal, Arnaldo

    2016-08-01

    We study three-dimensional vortex lattice structures in purely dipolar Bose–Einstein condensate (BEC). By using the mean-field approximation, we obtain a stability diagram for the vortex states in purely dipolar BECs as a function of harmonic trap aspect ratio (λ) and dipole–dipole interaction strength (D) under rotation. Rotating the condensate within the unstable region leads to collapse while in the stable region furnishes stable vortex lattices of dipolar BECs. We analyse stable vortex lattice structures by solving the three-dimensional time-dependent Gross–Pitaevskii equation in imaginary time. Further, the stability of vortex states is examined by evolution in real-time. We also investigate the distribution of vortices in a fully anisotropic trap by increasing eccentricity of the external trapping potential. We observe the breaking up of the condensate in two parts with an equal number of vortices on each when the trap is sufficiently weak, and the rotation frequency is high.

  11. Real-time data standards for the planetarium

    NASA Astrophysics Data System (ADS)

    Abbott, B.

    2008-06-01

    The American Museum of Natural History and the Hayden Planetarium have built the most accurate, comprehensive, 3-D atlas of the cosmos called the Digital Universe (DU). The DU enables one to journey from the mountains on Earth to the farthest quasars. The DU enjoys many distribution channels, including pre-rendered space-shows and news bulletins, live planetarium programmes, and a free version available on the internet. Recently, we have partnered with three planetarium vendors to bring the DU to planetariums around the world. These partnerships necessitatethe adoption or creation of standards for three-dimensional data and associated metadata. Many standards exist in the current Virtual Observatory framework and additional standards are being proposed as part of the VAMP programme. We intend to identify additional standards necessary for 3-D, real-time rendering tools for fulldome and flat-screen environments.

  12. Echo movement and evolution from real-time processing.

    NASA Technical Reports Server (NTRS)

    Schaffner, M. R.

    1972-01-01

    Preliminary experimental data on the effectiveness of conventional radars in measuring the movement and evolution of meteorological echoes when the radar is connected to a programmable real-time processor are examined. In the processor programming is accomplished by conceiving abstract machines which constitute the actual programs used in the methods employed. An analysis of these methods, such as the center of gravity method, the contour-displacement method, the method of slope, the cross-section method, the contour crosscorrelation method, the method of echo evolution at each point, and three-dimensional measurements, shows that the motions deduced from them may differ notably (since each method determines different quantities) but the plurality of measurement may give additional information on the characteristics of the precipitation.

  13. A three-dimensional asymmetric magnetopause model

    NASA Astrophysics Data System (ADS)

    Lin, R. L.; Zhang, X. X.; Liu, S. Q.; Wang, Y. L.; Gong, J. C.

    2010-04-01

    A new three-dimensional asymmetric magnetopause model has been developed for corrected GSM coordinates and parameterized by the solar wind dynamic and magnetic pressures (Pd + Pm), the interplanetary magnetic field (IMF) Bz, and the dipole tilt angle. On the basis of the magnetopause crossings from Geotail, IMP 8, Interball, TC1, Time History of Events and Macroscale Interactions during Substorms (THEMIS), Wind, Cluster, Polar, Los Alamos National Laboratory (LANL), GOES, and Hawkeye, and the corresponding upstream solar wind parameters from ACE, Wind, or OMNI, this model is constructed by the Levenberg-Marquardt method for nonlinear multiparameter fitting step-by-step over the divided regions. The asymmetries of the magnetopause and the indentations near the cusps are appropriately described in this new model. In addition, the saturation effect of IMF Bz on the subsolar distance and the extrapolation for the distant tail magnetopause are also considered. On the basis of this model, the power law index for the subsolar distance versus Pd + Pm is a bit less than -1/6, the northward IMF Bz almost does not influence the magnetopause, and the dipole tilt angle is very important to the north-south asymmetry and the location of indentations. In comparison with the previous empirical magnetopause models based on our database, the new model improves prediction capability to describe the three-dimensional structure of the magnetopause. It is shown that this new model can be used to quantitatively study how Pd + Pm compresses the magnetopause, how the southward IMF Bz erodes the magnetopause, and how the dipole tilt angle influences the north-south asymmetry and the indentations.

  14. Real-Time Data Display

    NASA Technical Reports Server (NTRS)

    Pedings, Marc

    2007-01-01

    RT-Display is a MATLAB-based data acquisition environment designed to use a variety of commercial off-the-shelf (COTS) hardware to digitize analog signals to a standard data format usable by other post-acquisition data analysis tools. This software presents the acquired data in real time using a variety of signal-processing algorithms. The acquired data is stored in a standard Operator Interactive Signal Processing Software (OISPS) data-formatted file. RT-Display is primarily configured to use the Agilent VXI (or equivalent) data acquisition boards used in such systems as MIDDAS (Multi-channel Integrated Dynamic Data Acquisition System). The software is generalized and deployable in almost any testing environment, without limitations or proprietary configuration for a specific test program or project. With the Agilent hardware configured and in place, users can start the program and, in one step, immediately begin digitizing multiple channels of data. Once the acquisition is completed, data is converted into a common binary format that also can be translated to specific formats used by external analysis software, such as OISPS and PC-Signal (product of AI Signal Research Inc.). RT-Display at the time of this reporting was certified on Agilent hardware capable of acquisition up to 196,608 samples per second. Data signals are presented to the user on-screen simultaneously for 16 channels. Each channel can be viewed individually, with a maximum capability of 160 signal channels (depending on hardware configuration). Current signal presentations include: time data, fast Fourier transforms (FFT), and power spectral density plots (PSD). Additional processing algorithms can be easily incorporated into this environment.

  15. Two and three dimensional magnetotelluric inversion

    SciTech Connect

    Booker, J.

    1993-01-01

    Electrical conductivity depends on properties such as the presence of ionic fluids in interconnected pores that are difficult to sense with other remote sensing techniques. Thus improved imaging of underground electrical structure has wide practical importance in exploring for groundwater, mineral and geothermal resources, and in assessing the diffusion of fluids in oil fields and waste sites. Because the electromagnetic inverse problem is fundamentally multi-dimensional, most imaging algorithms saturate available computer power long before they can deal with the complete data set. We have developed an algorithm to directly invert large multi-dimensional data sets that is orders of magnitude faster than competing methods. We have proven that a two-dimensional (2D) version of the algorithm is highly effective for real data and have made substantial progress towards a three-dimensional (3D) version. We are proposing to cure identified shortcomings and substantially expand the utility of the existing 2D program, overcome identified difficulties with extending our method to three-dimensions (3D) and embark on an investigation of related EM imaging techniques which may have the potential for even further increasing resolution.

  16. Three-dimensional imaging through scattering media using three-dimensionally coded pattern projection.

    PubMed

    Ando, Takamasa; Horisaki, Ryoichi; Tanida, Jun

    2015-08-20

    We propose a method for visualizing three-dimensional objects in scattering media. Our method is based on active illumination using three-dimensionally coded patterns and a numerical algorithm employing a sparsity constraint. We experimentally demonstrated the proposed imaging method for test charts located three-dimensionally at different depths in the space behind a translucent sheet. PMID:26368767

  17. Three Dimensional Illustrating--Three-Dimensional Vision and Deception of Sensibility

    ERIC Educational Resources Information Center

    Szállassy, Noémi; Gánóczy, Anita; Kriska, György

    2009-01-01

    The wide-spread digital photography and computer use gave the opportunity for everyone to make three-dimensional pictures and to make them public. The new opportunities with three-dimensional techniques give chance for the birth of new artistic photographs. We present in detail the biological roots of three-dimensional visualization, the phenomena…

  18. Mobile real time radiography system

    SciTech Connect

    Vigil, J.; Taggart, D.; Betts, S.

    1997-11-01

    A 450-keV Mobile Real Time Radiography (RTR) System was delivered to Los Alamos National Laboratory (LANL) in January 1996. It was purchased to inspect containers of radioactive waste produced at (LANL). Since its delivery it has been used to radiograph more than 600 drums of radioactive waste at various LANL sites. It has the capability of inspecting waste containers of various sizes from <1-gal. buckets up to standard waste boxes (SWB, dimensions 54.5 in. x 71 in. x 37 in.). It has three independent x-ray acquisition formats. The primary system used is a 12- in. image intensifier, the second is a 36-in. linear diode array (LDA) and the last is an open system. It is fully self contained with on board generator, HVAC, and a fire suppression system. It is on a 53-ft long x 8-ft. wide x 14-ft. high trailer that can be moved over any highway requiring only an easily obtainable overweight permit because it weights {approximately}38 tons. It was built to conform to industry standards for a cabinet system which does not require an exclusion zone. The fact that this unit is mobile has allowed us to operate where the waste is stored, rather than having to move the waste to a fixed facility.

  19. Three Dimensional Probability Distributions of the Interplanetary Magnetic Field

    NASA Astrophysics Data System (ADS)

    Podesta, J. J.

    2014-12-01

    Empirical probability density functions (PDFs) of the interplanetary magnetic field (IMF) have been derived from spacecraft data since the early years of the space age. A survey of the literature shows that past studies have investigated the separate Cartesian components of the magnetic field, the vector magnitude, and the direction of the IMF by means of one-dimensional or two-dimensional PDFs. But, to my knowledge, there exist no studies which investigate the three dimensional nature of the IMF by means of three dimensional PDFs, either in (Bx,By,Bz)(B_x,B_y,B_z)-coordinates or (BR,BT,BN)(B_R,B_T,B_N)-coordinates or some other appropriate system of coordinates. Likewise, there exist no studies which investigate three dimensional PDFs of magnetic field fluctuations, that is, vector differences bmB(t+τ)-bmB(t)bm{B}(t+tau)-bm{B}(t). In this talk, I shall present examples of three dimensional PDFs obtained from spacecraft data that demonstrate the solar wind magnetic field possesses a very interesting spatial structure that, to my knowledge, has not previously been identified. Perhaps because of the well known model of Barnes (1981) in which the magnitude of the IMF remains constant, it may be commonly believed that there is nothing new to learn from a full three dimensional PDF. To the contrary, there is much to learn from the investigation of three dimensional PDFs of the solar wind plasma velocity and the magnetic field, as well as three dimensional PDFs of their fluctuations. Knowledge of these PDFs will not only improve understanding of solar wind physics, it is an essential prerequisite for the construction of realistic models of the stochastic time series measured by a single spacecraft, one of the longstanding goals of space physics research. In addition, three dimensional PDFs contain valuable information about the anisotropy of solar wind fluctuations in three dimensional physical space, information that may help identify the reason why the three

  20. Students Collecting Real time Data

    NASA Astrophysics Data System (ADS)

    Miller, P.

    2006-05-01

    Students Collecting Real-Time Data The Hawaiian Islands Humpback Whale National Marine Sanctuary has created opportunities for middle and high school students to become Student Researchers and to be involved in real-time marine data collection. It is important that we expose students to different fields of science and encourage them to enter scientific fields of study. The Humpback Whale Sanctuary has an education visitor center in Kihei, Maui. Located right on the beach, the site has become a living classroom facility. There is a traditional Hawaiian fishpond fronting the property. The fishpond wall is being restored, using traditional methods. The site has the incredible opportunity of incorporating Hawaiian cultural practices with scientific studies. The Sanctuary offers opportunities for students to get involved in monitoring and data collection studies. Invasive Seaweed Study: Students are collecting data on invasive seaweed for the University of Hawaii. They pull a large net through the shallow waters. Seaweed is sorted, identified and weighed. The invasive seaweeds are removed. The data is recorded and sent to UH. Remote controlled monitoring boats: The sanctuary has 6 boogie board sized remote controlled boats used to monitor reefs. Boats have a camera with lights on the underside. The boats have water quality monitoring devices and GPS units. The video from the underwater camera is transmitted via a wireless transmission. Students are able to monitor the fish, limu and invertebrate populations on the reef and collect water quality data via television monitors or computers. The boat can also pull a small plankton tow net. Data is being compiled into data bases. Artificial Reef Modules: The Sanctuary has a scientific permit from the state to build and deploy artificial reef modules. High school students are designing and building modules. These are deployed out in the Fishpond fronting the Sanctuary site and students are monitoring them on a weekly basis

  1. VERSE - Virtual Equivalent Real-time Simulation

    NASA Technical Reports Server (NTRS)

    Zheng, Yang; Martin, Bryan J.; Villaume, Nathaniel

    2005-01-01

    Distributed real-time simulations provide important timing validation and hardware in the- loop results for the spacecraft flight software development cycle. Occasionally, the need for higher fidelity modeling and more comprehensive debugging capabilities - combined with a limited amount of computational resources - calls for a non real-time simulation environment that mimics the real-time environment. By creating a non real-time environment that accommodates simulations and flight software designed for a multi-CPU real-time system, we can save development time, cut mission costs, and reduce the likelihood of errors. This paper presents such a solution: Virtual Equivalent Real-time Simulation Environment (VERSE). VERSE turns the real-time operating system RTAI (Real-time Application Interface) into an event driven simulator that runs in virtual real time. Designed to keep the original RTAI architecture as intact as possible, and therefore inheriting RTAI's many capabilities, VERSE was implemented with remarkably little change to the RTAI source code. This small footprint together with use of the same API allows users to easily run the same application in both real-time and virtual time environments. VERSE has been used to build a workstation testbed for NASA's Space Interferometry Mission (SIM PlanetQuest) instrument flight software. With its flexible simulation controls and inexpensive setup and replication costs, VERSE will become an invaluable tool in future mission development.

  2. Three Dimensional Primary Hepatocyte Culture

    NASA Technical Reports Server (NTRS)

    Yoffe, Boris

    1998-01-01

    Our results demonstrated for the first time the feasibility of culturing PHH in microgravity bioreactors that exceeded the longest period obtained using other methods. Within the first week of culture, isolated hepatocytes started to form aggregates, which continuously increased in size (up to 1 cm) and macroscopically appeared as a multidimensional tissue-like assembly. To improve oxygenation and nutrition within the spheroids we performed experiments with the biodegradable nonwoven fiber-based polymers made from PolyGlycolic Acid (PGA). It has been shown that PGA scaffolds stimulate isolated cells to regenerate tissue with defined sizes and shapes and are currently being studied for various tissue-engineering applications. Our data demonstrated that culturing hepatocytes in the presence of PGA scaffolds resulted in more efficient cell assembly and formations of larger cell spheroids (up to 3 cm in length, see figure). The histology of cell aggregates cultured with PGA showed polymer fibers with attached hepatocytes. We initiated experiments to co-culture primary human hepatocytes with human microvascular endothelial cells in the bioreactor. The presence of endothelial cells in co-cultures were established by immunohistochemistry using anti-CD34 monoclonal Ab. Our preliminary data demonstrated that cultures of purified hepatocytes with human microvascular endothelial cells exhibited better growth and expressed higher levels of albumin MRNA for a longer period of time than cultures of ppfified, primary human hepatocytes cultured alone. We also evaluated microsomal deethylation activity of hepatocytes cultured in the presence of endothelial cells.In summary, we have established liver cell culture, which mimicked the structure and function of the parent tissue.

  3. Three dimensional optic tissue culture and process

    NASA Technical Reports Server (NTRS)

    Spaulding, Glenn F. (Inventor); Prewett, Tacey L. (Inventor); Goodwin, Thomas J. (Inventor); Francis, Karen M. (Inventor); Cardwell, Delmar R. (Inventor); Oconnor, Kim (Inventor); Fitzgerald, Wendy S. (Inventor); Aten, Laurie A. (Inventor)

    1994-01-01

    A process for artificially producing three-dimensional optic tissue has been developed. The optic cells are cultured in a bioreactor at low shear conditions. The tissue forms normal, functional tissue organization and extracellular matrix.

  4. Three Dimensional Optic Tissue Culture and Process

    NASA Technical Reports Server (NTRS)

    OConnor, Kim C. (Inventor); Spaulding, Glenn F. (Inventor); Goodwin, Thomas J. (Inventor); Aten, Laurie A. (Inventor); Francis, Karen M. (Inventor); Caldwell, Delmar R. (Inventor); Prewett, Tacey L. (Inventor); Fitzgerald, Wendy S. (Inventor)

    1999-01-01

    A process for artificially producing three-dimensional optic tissue has been developed. The optic cells are cultured in a bioireactor at low shear conditions. The tissue forms as normal, functional tissue grows with tissue organization and extracellular matrix formation.

  5. Three-dimensional stellarator equilibria by iteration

    SciTech Connect

    Boozer, A.H.

    1983-02-01

    The iterative method of evaluating plasma equilibria is especially simple in a magnetic coordinate representation. This method is particularly useful for clarifying the subtle constraints of three-dimensional equilibria and studying magnetic surface breakup at high plasma beta.

  6. THREE-DIMENSIONAL MODEL FOR HYPERTHERMIA CALCULATIONS

    EPA Science Inventory

    Realistic three-dimensional models that predict temperature distributions with a high degree of spatial resolution in bodies exposed to electromagnetic (EM) fields are required in the application of hyperthermia for cancer treatment. To ascertain the thermophysiologic response of...

  7. Device fabrication: Three-dimensional printed electronics

    NASA Astrophysics Data System (ADS)

    Lewis, Jennifer A.; Ahn, Bok Y.

    2015-02-01

    Can three-dimensional printing enable the mass customization of electronic devices? A study that exploits this method to create light-emitting diodes based on 'quantum dots' provides a step towards this goal.

  8. Three-dimensional magnetospheric equilibrium with isotropic pressure

    SciTech Connect

    Cheng, C.Z.

    1995-05-01

    In the absence of the toroidal flux, two coupled quasi two-dimensional elliptic equilibrium equations have been derived to describe self-consistent three-dimensional static magnetospheric equilibria with isotropic pressure in an optimal ({Psi},{alpha},{chi}) flux coordinate system, where {Psi} is the magnetic flux function, {chi} is a generalized poloidal angle, {alpha} is the toroidal angle, {alpha} = {phi} {minus} {delta}({Psi},{phi},{chi}) is the toroidal angle, {delta}({Psi},{phi},{chi}) is periodic in {phi}, and the magnetic field is represented as {rvec B} = {del}{Psi} {times} {del}{alpha}. A three-dimensional magnetospheric equilibrium code, the MAG-3D code, has been developed by employing an iterative metric method. The main difference between the three-dimensional and the two-dimensional axisymmetric solutions is that the field-aligned current and the toroidal magnetic field are finite for the three-dimensional case, but vanish for the two-dimensional axisymmetric case. With the same boundary flux surface shape, the two-dimensional axisymmetric results are similar to the three-dimensional magnetosphere at each local time cross section.

  9. Three-Dimensional Icosahedral Phase Field Quasicrystal

    NASA Astrophysics Data System (ADS)

    Subramanian, P.; Archer, A. J.; Knobloch, E.; Rucklidge, A. M.

    2016-08-01

    We investigate the formation and stability of icosahedral quasicrystalline structures using a dynamic phase field crystal model. Nonlinear interactions between density waves at two length scales stabilize three-dimensional quasicrystals. We determine the phase diagram and parameter values required for the quasicrystal to be the global minimum free energy state. We demonstrate that traits that promote the formation of two-dimensional quasicrystals are extant in three dimensions, and highlight the characteristics required for three-dimensional soft matter quasicrystal formation.

  10. Real time UAV autonomy through offline calculations

    NASA Astrophysics Data System (ADS)

    Jung, Sunghun

    Two or three dimensional mission plans for a single or a group of hover or fixed wing UAVs are generated. The mission plans can largely be separated into seven main parts. Firstly, the Region Growing algorithm is used to generate a map from 2D or 3D images. Secondly, the map is analyzed to separate each blocks using vertices of blocks and seven filtering steps. Thirdly, the Trapezoidal map algorithm is used to convert the map into a traversability graph. Fourthly, this process also filters out paths that are not traversable. That is, nodes located inside the blocks and too closely located nodes are filtered out. Fifthly, the Dijkstra algorithm is used to calculate the shortest path from a starting point to a goal point. Sixthly, the 1D Optimal Control algorithm is applied to manipulate the velocity and acceleration of the UAVs efficiently. Basically, the UAVs accelerates at one graph node and maintains a constant velocity and decelerates before reaching the next graph node. Lastly, Traveling Salesman Problem Method (TSP) algorithm is used to calculate the shortest path to search the whole region. After this discretization of space and time, it becomes possible to solve several autonomous mission planning problems. We focus on one of the most difficult problems: coordinated search. This is a multiple Traveling Salesman Problem (mTSP). We solve it by decomposing the search region and solving TSPs for each vehicle searching a sub-region. The mTSP is generally used when there are more than one salesman is used. In addition to the four main parts, there are three minor parts which support the main parts. Firstly, Target Detection algorithm is generated to detect a target located near the UAVs' path. A picture of the desired target is inserted into the algorithm before UAVs launch. Using the Scale-Invariant Transform Feature (SIFT) algorithm, a target with a specific shape can be detected. Secondly, Tracking algorithm is generated to manipulate UAVs to follow targets

  11. An introduction to real-time graphical techniques for analyzing multivariate data

    NASA Astrophysics Data System (ADS)

    Friedman, Jerome H.; McDonald, John Alan; Stuetzle, Werner

    1987-08-01

    Orion I is a graphics system used to study applications of computer graphics - especially interactive motion graphics - in statistics. Orion I is the newest of a family of "Prim" systems, whose most striking common feature is the use of real-time motion graphics to display three dimensional scatterplots. Orion I differs from earlier Prim systems through the use of modern and relatively inexpensive raster graphics and microprocessor technology. It also delivers more computing power to its user; Orion I can perform more sophisticated real-time computations than were possible on previous such systems. We demonstrate some of Orion I's capabilities in our film: "Exploring data with Orion I".

  12. Networked virtual reality for real-time 4D navigation of astrophysical turbulence data

    SciTech Connect

    Hudson, R.; Malagoli, A.

    1996-11-01

    This paper describes a prototype distributed virtual reality system for real-time spatial and temporal navigation of volumetric data generated by simulations of hydrodynamic turbulence on high-performance computers. This system makes use of a virtual environment connected to a scalably parallel computer via a scalably high-speed network. The data are either computed in real-time or precomputed on the parallel computer, then are transferred to the virtual environment where fast volume visualization is accomplished by using sophisticated three-dimensional texture-mapping hardware.

  13. Tomographic spatial filter velocimetry for three-dimensional measurement of fluid velocity

    NASA Astrophysics Data System (ADS)

    Hosokawa, Shigeo; Matsumoto, Takaaki; Tomiyama, Akio

    2013-09-01

    Spatial filter velocimetry (SFV) is extended to three-dimensional three-component velocimetry by coupling the SFV processing with a tomographic technique, which reconstructs three-dimensional particle distributions from stereoscopic particle images recorded by two cameras. Since time duration of a ghost particle traveling through an interrogation area of SFV is shorter than the transit time of a real tracer particle, a validation method of velocity data based on a particle transit time is used to eliminate ghost particles generated in the particle reconstruction process. Effect of a ghost particle on velocity evaluation is not significant due to the short transit time of a ghost particle. The developed system is applied to a free jet, and an impinging jet discharged from a circular pipe. Three-dimensional distributions of time-averaged velocity vectors of the jets are successfully measured by the developed tomographic spatial filter velocimetry (Tomo-SFV) in spite of using only two cameras. The peak-locking errors, which are apt to occur in particle image velocimetry measurements, do not appear in Tomo-SFV measurements.

  14. Three-dimensional super-resolution: theory, modeling, and field test results.

    PubMed

    Bulyshev, Alexander; Amzajerdian, Farzin; Roback, Vincent E; Hines, Glenn; Pierrottet, Diego; Reisse, Robert

    2014-04-20

    Many flash lidar applications continue to demand higher three-dimensional image resolution beyond the current state-of-the-art technology of the detector arrays and their associated readout circuits. Even with the available number of focal plane pixels, the required number of photons for illuminating all the pixels may impose impractical requirements on the laser pulse energy or the receiver aperture size. Therefore, image resolution enhancement by means of a super-resolution algorithm in near real time presents a very attractive solution for a wide range of flash lidar applications. This paper describes a super-resolution technique and illustrates its performance and merits for generating three-dimensional image frames at a video rate. PMID:24787583

  15. Three-Dimensional Super-Resolution: Theory, Modeling, and Field Tests Results

    NASA Technical Reports Server (NTRS)

    Bulyshev, Alexander; Amzajerdian, Farzin; Roback, Vincent E.; Hines, Glenn; Pierrottet, Diego; Reisse, Robert

    2014-01-01

    Many flash lidar applications continue to demand higher three-dimensional image resolution beyond the current state-of-the-art technology of the detector arrays and their associated readout circuits. Even with the available number of focal plane pixels, the required number of photons for illuminating all the pixels may impose impractical requirements on the laser pulse energy or the receiver aperture size. Therefore, image resolution enhancement by means of a super-resolution algorithm in near real time presents a very attractive solution for a wide range of flash lidar applications. This paper describes a superresolution technique and illustrates its performance and merits for generating three-dimensional image frames at a video rate.

  16. Three-dimensional mapping and intracardiac echocardiography in the treatment of sinoatrial nodal tachycardias.

    PubMed

    Nagarakanti, Ranghadham; Saksena, Sanjeev

    2016-06-01

    Three-dimensional mapping and intracardiac echocardiography are important tools for the study of the site of origin of an arrhythmia and its substrate. This review examines the application of these techniques in the diagnosis and treatment of sinoatrial tachycardias with a special focus on the syndrome of inappropriate sinus tachycardia. The use of these techniques in electrophysiologic mapping and interventions such as catheter ablation is discussed. Three-dimensional mapping provides unique insights into the generation of normal and abnormal sinus impulses in man and their propagation in the atrium. It permits precise placement of ablation lesions and assessment of real-time electrophysiologic impact of these interventions. Intracardiac echocardiography provides delineation of important anatomic structures in the vicinity of the sinoatrial node complex and monitors the safety of interventions such as catheter ablation. PMID:26607480

  17. Three-dimensional device characterization by high-speed cinematography

    NASA Astrophysics Data System (ADS)

    Maier, Claus; Hofer, Eberhard P.

    2001-10-01

    Testing of micro-electro-mechanical systems (MEMS) for optimization purposes or reliability checks can be supported by device visualization whenever an optical access is available. The difficulty in such an investigation is the short time duration of dynamical phenomena in micro devices. This paper presents a test setup to visualize movements within MEMS in real-time and in two perpendicular directions. A three-dimensional view is achieved by the combination of a commercial high-speed camera system, which allows to take up to 8 images of the same process with a minimum interframe time of 10 ns for the first direction, with a second visualization system consisting of a highly sensitive CCD camera working with a multiple exposure LED illumination in the perpendicular direction. Well synchronized this provides 3-D information which is treated by digital image processing to correct image distortions and to perform the detection of object contours. Symmetric and asymmetric binary collisions of micro drops are chosen as test experiments, featuring coalescence and surface rupture. Another application shown here is the investigation of sprays produced by an atomizer. The second direction of view is a prerequisite for this measurement to select an intended plane of focus.

  18. Three-dimensional models. [For orbital celestial mechanics

    SciTech Connect

    Hunter, C. )

    1990-06-01

    The Schwarzschild (1979) approach to the analysis of three-dimensional galactic models is reviewed. An analysis of triaxial Staeckel models is discussed which shows that such models have a wide variety of possible distribution functions. The uniqueness that Schwarzschild first encountered in his discrete formulation of the problem of finding a three-integral distribution function for a triaxial density is real and not an artifact of the finite cell approximation. 27 refs.

  19. A low cost real-time motion tracking approach using webcam technology

    PubMed Central

    Krishnan, Chandramouli; Washabaugh, Edward P.; Seetharaman, Yogesh

    2014-01-01

    Physical therapy is an important component of gait recovery for individuals with locomotor dysfunction. There is a growing body of evidence that suggests that incorporating a motor learning task through visual feedback of movement trajectory is a useful approach to facilitate therapeutic outcomes. Visual feedback is typically provided by recording the subject’s limb movement patterns using a three-dimensional motion capture system and displaying it in real-time using customized software. However, this approach can seldom be used in the clinic because of the technical expertise required to operate this device and the cost involved in procuring a three-dimensional motion capture system. In this paper, we describe a low cost two-dimensional real-time motion tracking approach using a simple webcam and an image processing algorithm in LabVIEW Vision Assistant. We also evaluated the accuracy of this approach using a high precision robotic device (Lokomat) across various walking speeds. Further, the reliability and feasibility of real-time motion-tracking were evaluated in healthy human participants. The results indicated that the measurements from the webcam tracking approach were reliable and accurate. Experiments on human subjects also showed that participants could utilize the real-time kinematic feedback generated from this device to successfully perform a motor learning task while walking on a treadmill. These findings suggest that the webcam motion tracking approach is a feasible low cost solution to perform real-time movement analysis and training. PMID:25555306

  20. A low cost real-time motion tracking approach using webcam technology.

    PubMed

    Krishnan, Chandramouli; Washabaugh, Edward P; Seetharaman, Yogesh

    2015-02-01

    Physical therapy is an important component of gait recovery for individuals with locomotor dysfunction. There is a growing body of evidence that suggests that incorporating a motor learning task through visual feedback of movement trajectory is a useful approach to facilitate therapeutic outcomes. Visual feedback is typically provided by recording the subject's limb movement patterns using a three-dimensional motion capture system and displaying it in real-time using customized software. However, this approach can seldom be used in the clinic because of the technical expertise required to operate this device and the cost involved in procuring a three-dimensional motion capture system. In this paper, we describe a low cost two-dimensional real-time motion tracking approach using a simple webcam and an image processing algorithm in LabVIEW Vision Assistant. We also evaluated the accuracy of this approach using a high precision robotic device (Lokomat) across various walking speeds. Further, the reliability and feasibility of real-time motion-tracking were evaluated in healthy human participants. The results indicated that the measurements from the webcam tracking approach were reliable and accurate. Experiments on human subjects also showed that participants could utilize the real-time kinematic feedback generated from this device to successfully perform a motor learning task while walking on a treadmill. These findings suggest that the webcam motion tracking approach is a feasible low cost solution to perform real-time movement analysis and training. PMID:25555306

  1. Three-dimensional coherent structures of electrokinetic instability

    NASA Astrophysics Data System (ADS)

    Demekhin, E. A.; Nikitin, N. V.; Shelistov, V. S.

    2014-07-01

    A direct numerical simulation of the three-dimensional elektrokinetic instability near a charge-selective surface (electric membrane, electrode, or system of micro- or nanochannels) has been carried out and analyzed. A special finite-difference method has been used for the space discretization along with a semi-implicit 31/3-step Runge-Kutta scheme for the integration in time. The calculations employ parallel computing. Three characteristic patterns, which correspond to the overlimiting currents, are observed: (a) two-dimensional electroconvective rolls, (b) three-dimensional regular hexagonal structures, and (c) three-dimensional structures of spatiotemporal chaos, which are a combination of unsteady hexagons, quadrangles, and triangles. The transition from (b) to (c) is accompanied by the generation of interacting two-dimensional solitary pulses.

  2. Three-dimensional coherent structures of electrokinetic instability.

    PubMed

    Demekhin, E A; Nikitin, N V; Shelistov, V S

    2014-07-01

    A direct numerical simulation of the three-dimensional elektrokinetic instability near a charge-selective surface (electric membrane, electrode, or system of micro- or nanochannels) has been carried out and analyzed. A special finite-difference method has been used for the space discretization along with a semi-implicit 31/3-step Runge-Kutta scheme for the integration in time. The calculations employ parallel computing. Three characteristic patterns, which correspond to the overlimiting currents, are observed: (a) two-dimensional electroconvective rolls, (b) three-dimensional regular hexagonal structures, and (c) three-dimensional structures of spatiotemporal chaos, which are a combination of unsteady hexagons, quadrangles, and triangles. The transition from (b) to (c) is accompanied by the generation of interacting two-dimensional solitary pulses. PMID:25122393

  3. Radiation hardness of three-dimensional polycrystalline diamond detectors

    SciTech Connect

    Lagomarsino, Stefano Sciortino, Silvio; Bellini, Marco; Corsi, Chiara; Cindro, Vladimir; Kanxheri, Keida; Servoli, Leonello; Morozzi, Arianna; Passeri, Daniele; Schmidt, Christian J.

    2015-05-11

    The three-dimensional concept in particle detection is based on the fabrication of columnar electrodes perpendicular to the surface of a solid state radiation sensor. It permits to improve the radiation resistance characteristics of a material by lowering the necessary bias voltage and shortening the charge carrier path inside the material. If applied to a long-recognized exceptionally radiation-hard material like diamond, this concept promises to pave the way to the realization of detectors of unprecedented performances. We fabricated conventional and three-dimensional polycrystalline diamond detectors, and tested them before and after neutron damage up to 1.2 ×10{sup 16 }cm{sup −2}, 1 MeV-equivalent neutron fluence. We found that the signal collected by the three-dimensional detectors is up to three times higher than that of the conventional planar ones, at the highest neutron damage ever experimented.

  4. Three-dimensional unstructured grid method applied to turbomachinery

    NASA Technical Reports Server (NTRS)

    Kwon, Oh Joon; Hah, Chunill

    1993-01-01

    This work has three objectives: to develop a three-dimensional flow solver based on unstructured tetrahedral meshes for turbomachinery flows; to validate the solver through comparisons with experimental data; and to apply the solver for better understanding of the flow through turbomachinery geometries and design improvement. The work followed three different approaches: an existing external flow solver/grid generator (USM3D/VGRID) was extensively modified for internal flows; a three-dimensional, finite-volume solver based on Roe's flux-difference splitting and explicit Runge-Kutta time stepping; and three-dimensional unstructured tetrahedral mesh generation using an advancing-front technique. A discussion of these topics is presented in viewgraph form.

  5. Coupled particle dispersion by three-dimensional vortex structures

    SciTech Connect

    Troutt, T.R.; Chung, J.N.; Crowe, C.T.

    1996-12-31

    The primary objective of this research program is to obtain understanding concerning the role of three-dimensional vortex structures in the dispersion of particles and droplets in free shear flows. This research program builds on previous studies which focused on the nature of particle dispersion in large scale quasi two-dimensional vortex structures. This investigation employs time dependent experimental and numerical techniques to provide information concerning the particulate dispersion produced by three dimensional vortex structures in free shear layers. The free shear flows investigated include modified plane mixing layers, and modified plane wakes. The modifications to these flows involve slight perturbations to the initiation boundary conditions such that three-dimensional vortex structures are rapidly generated by the experimental and numerical flow fields. Recent results support the importance of these vortex structures in the particle dispersion process.

  6. Three-dimensional space as a medium of quantum entanglement

    NASA Astrophysics Data System (ADS)

    Fiscaletti, Davide; Sorli, Amrit S.

    2012-01-01

    Most physicists today still conceptualize time as a part of the physical space in which material objects move, although time has never been observed and measured as a part of the space. The concept of time here presented is that time measured with clocks is merely the numerical order of material change, i.e. motion in a three-dimensional space. In special relativity the Minkowskian four-dimensional space-time can be replaced with a three-dimensional space where time does not represent a fourth coordinate of space but must be considered merely as a mathematical quantity measuring the numerical order of material changes. By quantum entanglement the three-dimensional space is a medium of a direct information transfer between quantum particles. Numerical order of non-local correlations between subatomic particles in EPR-type experiments and other immediate quantum processes is zero in the sense that the three-dimensional space acts as an immediate information medium between them

  7. Method for computing three-dimensional turbulent flows

    SciTech Connect

    Bernard, P.S.; Berger, B.S.

    1982-06-01

    The MVC (mean vorticity and covariance) turbulence closure is derived for three-dimensional turbulent flows. The derivation utilizes Lagrangian time expansion techniques applied to the unclosed terms of the mean vorticity and covariance equations. The closed mean vorticity equation is applied to the numerical solution of fully developed three-dimensional channel flow. Anisotropies in the wall region are modelled by pairs of counterrotating streamwise vortices. The numerical results are in close agreement with experimental data. Analysis of the contributions of the terms in the mean vorticity equation gives insight into the dynamics of the turbulent boundary. 41 references, 7 figures.

  8. Three-Dimensional Prints with Pinned Cylindrical Lens Arrays

    NASA Astrophysics Data System (ADS)

    Yasuda, Shin; Shimizu, Keishi

    2013-09-01

    An application of pinned cylindrical lens arrays (CLAs) reported in Opt. Rev. 19 (2012) 287 to three-dimensional prints is presented for the first time. This lens fabrication method features the easy control of the pitch and radius of curvature of the lens arrays by taking advantage of the pinning effect that the partition walls created on a polymeric substrate by scratching with a cutter blade prevent the ultraviolet curable polymer dispensed between the walls from spreading. It is demonstrated in this paper that a three-dimensional print was realized successfully with the pinned CLA fabricated with our method.

  9. Boundary Integral Solutions to Three-Dimensional Unconfined Darcy's Flow

    NASA Astrophysics Data System (ADS)

    Lennon, Gerard P.; Liu, Philip L.-F.; Liggett, James A.

    1980-08-01

    The boundary integral equation method (BIEM) is used to solve three-dimensional potential flow problems in porous media. The problems considered here are time dependent and have a nonlinear boundary condition on the free surface. The entire boundary, including the moving free surface, discretized into linear finite elements for the purpose of evaluating the boundary integrals. The technique allows transient, three-dimensional problems to be solved with reasonable computational costs. Numerical examples include recharge through rectangular and circular areas and seepage flow from a surface pond. The examples are used to illustrate the method and show the nonlinear effects.

  10. Binary Colloidal Alloy Test-5: Three-Dimensional Melt

    NASA Technical Reports Server (NTRS)

    Yodh, Arjun G.

    2008-01-01

    Binary Colloidal Alloy Test - 5: Three-Dimensional Melt (BCAT-5-3DMelt) photographs initially randomized colloidal samples in microgravity to determine their resulting structure over time. BCAT-5-3D-Melt will allow the scientists to capture the kinetics (evolution) of their samples, as well as the final equilibrium state of each sample. BCAT-5-3D-Melt will look at the mechanisms of melting using three-dimensional temperature sensitive colloidal crystals. Results will help scientists develop fundamental physics concepts previously shadowed by the effects of gravity.

  11. Three-dimensional modeling equatorial spread F

    NASA Astrophysics Data System (ADS)

    Huba, J. D.; Krall, J.; Joyce, G.

    2008-12-01

    Equatorial spread F (ESF) is a low-latitude ionospheric phenomenon that leads to the development of large scale electron density depletions that adversely affect communications and navigation systems. The development of models to understand and predict the onset and evolution of ESF is therefore critically important to a number of space-based systems. To this end, NRL has developed a three-dimensional model of ESF. The global NRL ionosphere model SAMI3 has been modified to simulate a narrow wedge of the post-sunset ionosphere to capture the onset and evolution of ESF. Preliminary results indicate that (1) bubbles can rise to ~ 1600 km, (2) extremely steep ion density gradients can develop in both longitude and latitude, (3) upward plasma velocities approach 1 km/s, and (4) the growth time of the instability is ~eq 15 min. We will also report the effects of meridional and zonal winds on bubble development, as well as ion composition (both atomic and molecular). The simulations will focus on current, low solar activity conditions, and results will be compared to C/NOFS data where available. Research supported by ONR

  12. Three Dimensional Numerical Analysis on Discharge Properties

    NASA Astrophysics Data System (ADS)

    Takaishi, Kenji; Katsurai, Makoto

    2003-10-01

    A three dimensional simulation code with the finite difference time domain (FDTD) method combined with the two fluids model for electron and ion has been developed for the microwave excited surface wave plasma in the RDL-SWP device. This code permits the numerical analysis of the spatial distributions of electric field, power absorption, electron density and electron temperature. At low gas pressure of about 10 mTorr, the numerical results compared with the experimental measurements that shows the validity of this 3-D simulation code. A simplified analysis assuming that an electron density is spatially uniform has been studied and its applicability is evaluated by 3-D simulation. The surface wave eigenmodes are determined by electron density, and it is found that the structure of the device strongly influences to the spatial distribution of the electric fields of surface wave in a low density area. A method to irradiate a microwave to the whole surface area of the plasma is proposed which is found to be effective to obtain a high uniformity distribution of electron density.

  13. A three-dimensional human walking model

    NASA Astrophysics Data System (ADS)

    Yang, Q. S.; Qin, J. W.; Law, S. S.

    2015-11-01

    A three-dimensional human bipedal walking model with compliant legs is presented in this paper. The legs are modeled with time-variant dampers, and the model is able to characterize the gait pattern of an individual using a minimal set of parameters. Feedback control, for both the forward and lateral movements, is implemented to regulate the walking performance of the pedestrian. The model provides an improvement over classic invert pendulum models. Numerical studies were undertaken to investigate the effects of leg stiffness and attack angle. Simulation results show that when walking at a given speed, increasing the leg stiffness with a constant attack angle results in a longer step length, a higher step frequency, a faster walking speed and an increase in both the peak vertical and lateral ground reaction forces. Increasing the attack angle with a constant leg stiffness results in a higher step frequency, a decrease in the step length, an increase in the total energy of the system and a decrease in both the peak vertical and lateral ground reaction forces.

  14. Research in Distributed Real-Time Systems

    NASA Technical Reports Server (NTRS)

    Mukkamala, R.

    1997-01-01

    This document summarizes the progress we have made on our study of issues concerning the schedulability of real-time systems. Our study has produced several results in the scalability issues of distributed real-time systems. In particular, we have used our techniques to resolve schedulability issues in distributed systems with end-to-end requirements. During the next year (1997-98), we propose to extend the current work to address the modeling and workload characterization issues in distributed real-time systems. In particular, we propose to investigate the effect of different workload models and component models on the design and the subsequent performance of distributed real-time systems.

  15. Three-dimensional transient electromagnetic modeling in the Laplace Domain

    SciTech Connect

    Mizunaga, H.; Lee, Ki Ha; Kim, H.J.

    1998-09-01

    In modeling electromagnetic responses, Maxwell's equations in the frequency domain are popular and have been widely used (Nabighian, 1994; Newman and Alumbaugh, 1995; Smith, 1996, to list a few). Recently, electromagnetic modeling in the time domain using the finite difference (FDTD) method (Wang and Hohmann, 1993) has also been used to study transient electromagnetic interactions in the conductive medium. This paper presents a new technique to compute the electromagnetic response of three-dimensional (3-D) structures. The proposed new method is based on transforming Maxwell's equations to the Laplace domain. For each discrete Laplace variable, Maxwell's equations are discretized in 3-D using the staggered grid and the finite difference method (FDM). The resulting system of equations is then solved for the fields using the incomplete Cholesky conjugate gradient (ICCG) method. The new method is particularly effective in saving computer memory since all the operations are carried out in real numbers. For the same reason, the computing speed is faster than frequency domain modeling. The proposed approach can be an extremely useful tool in developing an inversion algorithm using the time domain data.

  16. Reconstructing three-dimensional reentrant cardiac electrical wave dynamics using data assimilation.

    PubMed

    Hoffman, M J; LaVigne, N S; Scorse, S T; Fenton, F H; Cherry, E M

    2016-01-01

    For many years, reentrant scroll waves have been predicted and studied as an underlying mechanism for cardiac arrhythmias using numerical techniques, and high-resolution mapping studies using fluorescence recordings from the surfaces of cardiac tissue preparations have confirmed the presence of visible spiral waves. However, assessing the three-dimensional dynamics of these reentrant waves using experimental techniques has been limited to verifying stable scroll-wave dynamics in relatively thin preparations. We propose a different approach to recovering the three-dimensional dynamics of reentrant waves in the heart. By applying techniques commonly used in weather forecasting, we combine dual-surface observations from a particular experiment with predictions from a numerical model to reconstruct the full three-dimensional time series of the experiment. Here, we use model-generated surrogate observations from a numerical experiment to evaluate the performance of the ensemble Kalman filter in reconstructing such time series for a discordant alternans state in one spatial dimension and for scroll waves in three dimensions. We show that our approach is able to recover time series of both observed and unobserved variables matching the truth. Where nearby observations are available, the error is reduced below the synthetic observation error, with a smaller reduction with increased distance from observations. Our findings demonstrate that state reconstruction for spatiotemporally complex cardiac electrical dynamics is possible and will lead naturally to applications using real experimental data. PMID:26826859

  17. Reconstructing three-dimensional reentrant cardiac electrical wave dynamics using data assimilation

    NASA Astrophysics Data System (ADS)

    Hoffman, M. J.; LaVigne, N. S.; Scorse, S. T.; Fenton, F. H.; Cherry, E. M.

    2016-01-01

    For many years, reentrant scroll waves have been predicted and studied as an underlying mechanism for cardiac arrhythmias using numerical techniques, and high-resolution mapping studies using fluorescence recordings from the surfaces of cardiac tissue preparations have confirmed the presence of visible spiral waves. However, assessing the three-dimensional dynamics of these reentrant waves using experimental techniques has been limited to verifying stable scroll-wave dynamics in relatively thin preparations. We propose a different approach to recovering the three-dimensional dynamics of reentrant waves in the heart. By applying techniques commonly used in weather forecasting, we combine dual-surface observations from a particular experiment with predictions from a numerical model to reconstruct the full three-dimensional time series of the experiment. Here, we use model-generated surrogate observations from a numerical experiment to evaluate the performance of the ensemble Kalman filter in reconstructing such time series for a discordant alternans state in one spatial dimension and for scroll waves in three dimensions. We show that our approach is able to recover time series of both observed and unobserved variables matching the truth. Where nearby observations are available, the error is reduced below the synthetic observation error, with a smaller reduction with increased distance from observations. Our findings demonstrate that state reconstruction for spatiotemporally complex cardiac electrical dynamics is possible and will lead naturally to applications using real experimental data.

  18. Three-dimensional AOTV flowfields in chemical nonequilibrium

    NASA Technical Reports Server (NTRS)

    Gnoffo, P. A.; Mccandless, R. S.

    1986-01-01

    A technique for upwind differencing of the three-dimensional species continuity equations is presented which permits computation of steady flows in chemical equilibrium and nonequilibrium. The capabilities and shortcomings of the present approach for equilibrium and nonequilibrium flows is discussed. Modifications now being investigated to improve computational time are outlined.

  19. Quantum field between moving mirrors: A three dimensional example

    NASA Technical Reports Server (NTRS)

    Hacyan, S.; Jauregui, Roco; Villarreal, Carlos

    1995-01-01

    The scalar quantum field uniformly moving plates in three dimensional space is studied. Field equations for Dirichlet boundary conditions are solved exactly. Comparison of the resulting wavefunctions with their instantaneous static counterpart is performed via Bogolubov coefficients. Unlike the one dimensional problem, 'particle' creation as well as squeezing may occur. The time dependent Casimir energy is also evaluated.

  20. Three-dimensional cell to tissue development process

    NASA Technical Reports Server (NTRS)

    Goodwin, Thomas J. (Inventor); Parker, Clayton R. (Inventor)

    2008-01-01

    An improved three-dimensional cell to tissue development process using a specific time varying electromagnetic force, pulsed, square wave, with minimum fluid shear stress, freedom for 3-dimensional spatial orientation of the suspended particles and localization of particles with differing or similar sedimentation properties in a similar spatial region.

  1. Study of cavity type antenna structure of large-area 915 MHz ultra-high frequency wave plasma device based on three-dimensional finite difference time-domain analysis

    SciTech Connect

    Chang, Xijiang; Graduate School of Science and Engineering, Shizuoka University, 3-5-1 Johoku, Hamamatsu 432-8561 ; Kunii, Kazuki; Liang, Rongqing; Nagatsu, Masaaki; Graduate School of Engineering, Shizuoka University,3-5-1 Johoku, Hamamatsu 432-8561

    2013-11-14

    A large-area planar plasma source with a resonant cavity type launcher driven by a 915 MHz ultra-high frequency wave was developed. Theoretical analysis with the three-dimensional finite difference time-domain simulation was carried out to determine the optimized launcher structure by analyzing the resonant transverse magnetic mode in the resonant cavity. Numerical result expects that the resonant electric field distribution inside the cavity dominantly consists of the TM{sub 410} mode. The resonant cavity type launcher having 8 holes in an octagonal geometry was designed to fit the resonant transverse magnetic mode. Adjusting 8 hole positions of the launcher to the field pattern of the resonant TM{sub 410} mode, we found that the plasma density increased about 40%∼50% from 1.0∼1.1 × 10{sup 11} cm{sup −3} to ∼1.5 × 10{sup 11} cm{sup −3} at the same incident power of 2.5 kW, compared with the previous results with the launcher having 6 holes in the hexagonal geometry. It is also noted that the electron density changes almost linearly with the incident wave power without any mode jumps.

  2. Vision in our three-dimensional world.

    PubMed

    Parker, Andrew J

    2016-06-19

    Many aspects of our perceptual experience are dominated by the fact that our two eyes point forward. Whilst the location of our eyes leaves the environment behind our head inaccessible to vision, co-ordinated use of our two eyes gives us direct access to the three-dimensional structure of the scene in front of us, through the mechanism of stereoscopic vision. Scientific understanding of the different brain regions involved in stereoscopic vision and three-dimensional spatial cognition is changing rapidly, with consequent influences on fields as diverse as clinical practice in ophthalmology and the technology of virtual reality devices.This article is part of the themed issue 'Vision in our three-dimensional world'. PMID:27269595

  3. Topology of three-dimensional separated flows

    NASA Technical Reports Server (NTRS)

    Tobak, M.; Peake, D. J.

    1981-01-01

    Based on the hypothesis that patterns of skin-friction lines and external streamlines reflect the properties of continuous vector fields, topology rules define a small number of singular points (nodes, saddle points, and foci) that characterize the patterns on the surface and on particular projections of the flow (e.g., the crossflow plane). The restricted number of singular points and the rules that they obey are considered as an organizing principle whose finite number of elements can be combined in various ways to connect together the properties common to all steady three dimensional viscous flows. Introduction of a distinction between local and global properties of the flow resolves an ambiguity in the proper definition of a three dimensional separated flow. Adoption of the notions of topological structure, structural stability, and bifurcation provides a framework to describe how three dimensional separated flows originate and succeed each other as the relevant parameters of the problem are varied.

  4. Three dimensional responsive structure of tough hydrogels

    NASA Astrophysics Data System (ADS)

    Yang, Xuxu; Ma, Chunxin; Li, Chi; Xie, Yuhan; Huang, Xiaoqiang; Jin, Yongbin; Zhu, Ziqi; Liu, Junjie; Li, Tiefeng

    2015-04-01

    Three dimensional responsive structures have high value for the application of responsive hydrogels in various fields such as micro fluid control, tissue engineering and micro robot. Whereas various hydrogels with stimuli-responsive behaviors have been developed, designing and fabricating of the three dimensional responsive structures remain challenging. We develop a temperature responsive double network hydrogel with novel fabrication methods to assemble the complex three dimensional responsive structures. The shape changing behavior of the structures can be significantly increased by building blocks with various responsiveness. Mechanical instability is built into the structure with the proper design and enhance the performance of the structure. Finite element simulation are conducted to guide the design and investigate the responsive behavior of the hydrogel structures

  5. Vision in our three-dimensional world

    PubMed Central

    2016-01-01

    Many aspects of our perceptual experience are dominated by the fact that our two eyes point forward. Whilst the location of our eyes leaves the environment behind our head inaccessible to vision, co-ordinated use of our two eyes gives us direct access to the three-dimensional structure of the scene in front of us, through the mechanism of stereoscopic vision. Scientific understanding of the different brain regions involved in stereoscopic vision and three-dimensional spatial cognition is changing rapidly, with consequent influences on fields as diverse as clinical practice in ophthalmology and the technology of virtual reality devices. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269595

  6. Three-dimensional separation and reattachment

    NASA Technical Reports Server (NTRS)

    Peake, D. J.; Tobak, M.

    1982-01-01

    The separation of three dimensional turbulent boundary layers from the lee of flight vehicles at high angles of attack is investigated. The separation results in dominant, large scale, coiled vortex motions that pass along the body in the general direction of the free stream. In all cases of three dimensional flow separation and reattachment, the assumption of continuous vector fields of skin friction lines and external flow streamlines, coupled with simple laws of topology, provides a flow grammar whose elemental constituents are the singular points: the nodes, spiral nodes (foci), and saddles. The phenomenon of three dimensional separation may be constrained as either a local or a global event, depending on whether the skin friction line that becomes a line of separation originates at a node or a saddle point.

  7. Three-dimensional separation and reattachment

    NASA Technical Reports Server (NTRS)

    Peake, D. J.; Tobak, M.

    1982-01-01

    The separation of three dimensional turbulent boundary layers from the lee of flight vehicles at high angles of attack is investigated. The separation results in dominant, large scale, coiled vortex motions that pass along the body in the general direction of the free stream. In all cases of three dimensional flow separation and reattachment, the assumption of continuous vector fields of skin friction lines and external flow streamlines, coupled with simple laws of topology, provides a flow grammar whose elemental constituents are the singular points: the nodes, spiral nodes (foci), and saddles. The phenomenon of three dimensional separation may be construed as either a local or a global event, depending on whether the skin friction line that becomes a line of separation originates at a node or a saddle point.

  8. Update on New Tools for Three-dimensional Navigation in Endovascular Procedures

    PubMed Central

    van den Berg, Jos C.

    2014-01-01

    Three-dimensional (3D) guidance for endovascular procedures has developed over the last decade from 3D rotational angiography to the use of dynamic 3D roadmap techniques. The latest development is image merging. This technique combines real-time feedback of fluoroscopy with optimal soft-tissue contrast of previously performed computed tomography (CT) or magnetic resonance angiography. Merging of CT angiography and cone-beam CT/fluoroscopic images is feasible, and preliminary results look promising. Merging will allow us to further reduce radiation exposure, contrast dose, and procedural time, and its main use and benefit will be in complex endovascular interventions. PMID:26798746

  9. Three-Dimensional Robotic Vision System

    NASA Technical Reports Server (NTRS)

    Nguyen, Thinh V.

    1989-01-01

    Stereoscopy and motion provide clues to outlines of objects. Digital image-processing system acts as "intelligent" automatic machine-vision system by processing views from stereoscopic television cameras into three-dimensional coordinates of moving object in view. Epipolar-line technique used to find corresponding points in stereoscopic views. Robotic vision system analyzes views from two television cameras to detect rigid three-dimensional objects and reconstruct numerically in terms of coordinates of corner points. Stereoscopy and effects of motion on two images complement each other in providing image-analyzing subsystem with clues to natures and locations of principal features.

  10. Three-dimensional magnetic bubble memory system

    NASA Technical Reports Server (NTRS)

    Stadler, Henry L. (Inventor); Katti, Romney R. (Inventor); Wu, Jiin-Chuan (Inventor)

    1994-01-01

    A compact memory uses magnetic bubble technology for providing data storage. A three-dimensional arrangement, in the form of stacks of magnetic bubble layers, is used to achieve high volumetric storage density. Output tracks are used within each layer to allow data to be accessed uniquely and unambiguously. Storage can be achieved using either current access or field access magnetic bubble technology. Optical sensing via the Faraday effect is used to detect data. Optical sensing facilitates the accessing of data from within the three-dimensional package and lends itself to parallel operation for supporting high data rates and vector and parallel processing.

  11. Three-Dimensional Extended Bargmann Supergravity.

    PubMed

    Bergshoeff, Eric; Rosseel, Jan

    2016-06-24

    We show that three-dimensional general relativity, augmented with two vector fields, allows for a nonrelativistic limit, different from the standard limit leading to Newtonian gravity, that results in a well-defined action which is of the Chern-Simons type. We show that this three-dimensional "extended Bargmann gravity," after coupling to matter, leads to equations of motion allowing a wider class of background geometries than the ones that one encounters in Newtonian gravity. We give the supersymmetric generalization of these results and point out an important application in the context of calculating partition functions of nonrelativistic field theories using localization techniques. PMID:27391712

  12. Three-Dimensional Extended Bargmann Supergravity

    NASA Astrophysics Data System (ADS)

    Bergshoeff, Eric; Rosseel, Jan

    2016-06-01

    We show that three-dimensional general relativity, augmented with two vector fields, allows for a nonrelativistic limit, different from the standard limit leading to Newtonian gravity, that results in a well-defined action which is of the Chern-Simons type. We show that this three-dimensional "extended Bargmann gravity," after coupling to matter, leads to equations of motion allowing a wider class of background geometries than the ones that one encounters in Newtonian gravity. We give the supersymmetric generalization of these results and point out an important application in the context of calculating partition functions of nonrelativistic field theories using localization techniques.

  13. Study of the Three-dimensional Coronal Magnetic Field of Active Region 11117 around the Time of a Confined Flare Using a Data-Driven CESE-MHD Model

    NASA Astrophysics Data System (ADS)

    Jiang, Chaowei; Feng, Xueshang; Wu, S. T.; Hu, Qiang

    2012-11-01

    We apply a data-driven magnetohydrodynamics (MHD) model to investigate the three-dimensional (3D) magnetic field of NOAA active region (AR) 11117 around the time of a C-class confined flare that occurred on 2010 October 25. The MHD model, based on the spacetime conservation-element and solution-element scheme, is designed to focus on the magnetic field evolution and to consider a simplified solar atomsphere with finite plasma β. Magnetic vector-field data derived from the observations at the photosphere is inputted directly to constrain the model. Assuming that the dynamic evolution of the coronal magnetic field can be approximated by successive equilibria, we solve a time sequence of MHD equilibria based on a set of vector magnetograms for AR 11117 taken by the Helioseismic and Magnetic Imager on board the Solar Dynamic Observatory around the time of the flare. The model qualitatively reproduces the basic structures of the 3D magnetic field, as supported by the visual similarity between the field lines and the coronal loops observed by the Atmospheric Imaging Assembly, which shows that the coronal field can indeed be well characterized by the MHD equilibrium in most cases. The magnetic configuration changes very little during the studied time interval of 2 hr. A topological analysis reveals that the small flare is correlated with a bald patch (BP, where the magnetic field is tangent to the photosphere), suggesting that the energy release of the flare can be understood by magnetic reconnection associated with the BP separatrices. The total magnetic flux and energy keep increasing slightly in spite of the flare, while the computed magnetic free energy drops during the flare by ~1030 erg, which seems to be adequate in providing the energy budget of a minor C-class confined flare.

  14. Real time programming environment for Windows

    SciTech Connect

    LaBelle, D.R.

    1998-04-01

    This document provides a description of the Real Time Programming Environment (RTProE). RTProE tools allow a programmer to create soft real time projects under general, multi-purpose operating systems. The basic features necessary for real time applications are provided by RTProE, leaving the programmer free to concentrate efforts on his specific project. The current version supports Microsoft Windows{trademark} 95 and NT. The tasks of real time synchronization and communication with other programs are handled by RTProE. RTProE includes a generic method for connecting a graphical user interface (GUI) to allow real time control and interaction with the programmer`s product. Topics covered in this paper include real time performance issues, portability, details of shared memory management, code scheduling, application control, Operating System specific concerns and the use of Computer Aided Software Engineering (CASE) tools. The development of RTProE is an important step in the expansion of the real time programming community. The financial costs associated with using the system are minimal. All source code for RTProE has been made publicly available. Any person with access to a personal computer, Windows 95 or NT, and C or FORTRAN compilers can quickly enter the world of real time modeling and simulation.

  15. Hand-held optoacoustic probe for three-dimensional imaging of human morphology and function

    NASA Astrophysics Data System (ADS)

    Deán-Ben, X. Luís.; Razansky, Daniel

    2014-03-01

    We report on a hand-held imaging probe for real-time optoacoustic visualization of deep tissues in three dimensions. The proposed solution incorporates a two-dimensional array of ultrasonic sensors densely distributed on a spherical surface, whereas illumination is performed coaxially through a cylindrical cavity in the array. Visualization of three-dimensional tomographic data at a frame rate of 10 images per second is enabled by parallel recording of 256 time-resolved signals for each individual laser pulse along with a highly efficient GPUbased real-time reconstruction. A liquid coupling medium (water), enclosed in a transparent membrane, is used to guarantee transmission of the optoacoustically generated waves to the ultrasonic detectors. Excitation at multiple wavelengths further allows imaging spectrally distinctive tissue chromophores such as oxygenated and deoxygenated haemoglobin. The performance is showcased by video-rate tracking of deep tissue vasculature and three-dimensional measurements of blood oxygenenation in a healthy human volunteer. The flexibility provided by the hand-held hardware design, combined with the real-time operation, makes the developed platform highly usable for both small animal research and clinical imaging in multiple indications, including cancer, inflammation, skin and cardiovascular diseases, diagnostics of lymphatic system and breast

  16. Three-dimensional ring current decay model

    NASA Astrophysics Data System (ADS)

    Fok, Mei Ching; Moore, Thomas E.; Kozyra, Janet U.; Ho, George C.; Hamilton, Douglas C.

    1995-06-01

    This work is an extension of a previous ring current decay model. In the previous work, a two-dimensional kinetic model was constructed to study the temporal variations of the equatorially mirroring ring current ions, considering charge exchange and Coulomb drag losses along drift paths in a magnetic dipole field. In this work, particles with arbitrary pitch angle are considered. By bounce averaging the kinetic equation of the phase space density, information along magnetic field lines can be inferred from the equator. The three-dimensional model is used to simulate the recovery phase of a model great magnetic storm, similar to that which occurred in early February 1986. The initial distribution of ring current ions (at the minimum Dst) is extrapolated to all local times from AMPTE/CCE spacecraft observations on the dawnside and duskside of the inner magnetosphere spanning the L value range L=2.25 to 6.75. Observations by AMPTE/CCE of ring current distributions over subsequent orbits during the storm recovery phase are compared to model outputs. In general, the calculated ion fluxes are consistent with observations, except for H+ fluxes at tens of keV, which are always overestimated. A newly invented visualization idea, designated as a chromogram, is used to display the spatial and energy dependence of the ring current ion diifferential flux. Important features of storm time ring current, such as day-night asymmetry during injection and drift hole on the dayside at low energies (<10 keV), are manifested in the chromogram representation. The pitch angle distribution is well fit by the function, j0(1+Ayn), where y is sine of the equatorial pitch angle. The evolution of the index n is a combined effect of charge exchange loss and particle drift. At low energies (<30 keV), both drift dispersion and charge exchange are important in determining n. ©American Geophysical 1995

  17. Three Dimensional Printing in Orthopaedic Surgery

    PubMed Central

    Mulford, Jonathan; MacKay, N; Babazadeh, S

    2016-01-01

    Objectives: Three dimensional (3D) printing technology has many current and future applications in orthopaedics. The objectives of this article are to review published literature regarding applications of 3D technology in orthopaedic surgery with a focus on knee surgery. Methods: A narrative review of the applications of 3D printing technology in orthopaedic practice was achieved by a search of computerised databases, internet and reviewing references of identified publications. Results: There is current widespread use of 3D printing technology in orthopaedics. 3D technology can be used in education, preoperative planning and custom manufacturing. Custom manufacturing applications include surgical guides, prosthetics and implants. Many future applications exist including biological applications. 3D printed models of anatomy have assisted in the education of patients, students, trainees and surgeons. 3D printed models also assist with surgical planning of complex injuries or unusual anatomy. 3D printed surgical guides may simplify surgery, make surgery precise and reduce operative time. Computer models based on MRI or CT scans are utilised to plan surgery and placement of implants. Complex osteotomies can be performed using 3D printed surgical guides. This can be particularly useful around the knee. A 3D printed guide allows pre osteotomy drill holes for the plate fixation and provides an osteotomy guide to allow precise osteotomy. 3D printed surgical guides for knee replacement are widely available. 3D printing has allowed the emergence of custom implants. Custom implants that are patient specific have been particularly used for complex revision arthroplasty or for very difficult cases with altered anatomy. Future applications are likely to include biological 3D printing of cartilage and bone scaffolds. Conclusion: 3D printing in orthopaedic surgery has and will continue to change orthopaedic practice. Its role is to provide safe, reproducible, reliable models with

  18. Three-dimensional ring current decay model

    NASA Technical Reports Server (NTRS)

    Fok, Mei-Ching; Moore, Thomas E.; Kozyra, Janet U.; Ho, George C.; Hamilton, Douglas C.

    1995-01-01

    This work is an extension of a previous ring current decay model. In the previous work, a two-dimensional kinetic model was constructed to study the temporal variations of the equatorially mirroring ring current ions, considering charge exchange and Coulomb drag losses along drift paths in a magnetic dipole field. In this work, particles with arbitrary pitch angle are considered. By bounce averaging the kinetic equation of the phase space density, information along magnetic field lines can be inferred from the equator. The three-dimensional model is used to simulate the recovery phase of a model great magnetic storm, similar to that which occurred in early February 1986. The initial distribution of ring current ions (at the minimum Dst) is extrapolated to all local times from AMPTE/CCE spacecraft observations on the dawnside and duskside of the inner magnetosphere spanning the L value range L = 2.25 to 6.75. Observations by AMPTE/CCE of ring current distributions over subsequent orbits during the storm recovery phase are compared to model outputs. In general, the calculated ion fluxes are consistent with observations, except for H(+) fluxes at tens of keV, which are always overestimated. A newly invented visualization idea, designated as a chromogram, is used to display the spatial and energy dependence of the ring current ion differential flux. Important features of storm time ring current, such as day-night asymmetry during injection and drift hole on the dayside at low energies (less than 10 keV), are manifested in the chromogram representation. The pitch angle distribution is well fit by the function, J(sub o)(1 + Ay(sup n)), where y is sine of the equatorial pitch angle. The evolution of the index n is a combined effect of charge exchange loss and particle drift. At low energies (less than 30 keV), both drift dispersion and charge exchange are important in determining n.

  19. Combined Labelled and Label-free SERS Probes for Triplex Three-dimensional Cellular Imaging

    NASA Astrophysics Data System (ADS)

    Chen, Yong; Bai, Xiangru; Su, Le; Du, Zhanwei; Shen, Aiguo; Materny, Arnulf; Hu, Jiming

    2016-01-01

    Cells are complex chemical systems, where the molecular composition at different cellular locations and specific intracellular chemical interactions determine the biological function. An in-situ nondestructive characterization of the complicated chemical processes (like e.g. apoptosis) is the goal of our study. Here, we present the results of simultaneous and three-dimensional imaging of double organelles (nucleus and membrane) in single HeLa cells by means of either labelled or label-free surface-enhanced Raman spectroscopy (SERS). This combination of imaging with and without labels is not possible when using fluorescence microscopy. The SERS technique is used for a stereoscopic description of the intrinsic chemical nature of nuclei and the precise localization of folate (FA) and luteinizing hormone-releasing hormone (LHRH) on the membrane under highly confocal conditions. We also report on the time-dependent changes of cell nuclei as well as membrane receptor proteins during apoptosis analyzed by statistical multivariate methods. The multiplex three-dimensional SERS imaging technique allows for both temporal (real time) and spatial (multiple organelles and molecules in three-dimensional space) live-cell imaging and therefore provides a new and attractive 2D/3D tracing method in biomedicine on subcellular level.

  20. Combined Labelled and Label-free SERS Probes for Triplex Three-dimensional Cellular Imaging.

    PubMed

    Chen, Yong; Bai, Xiangru; Su, Le; Du, Zhanwei; Shen, Aiguo; Materny, Arnulf; Hu, Jiming

    2016-01-01

    Cells are complex chemical systems, where the molecular composition at different cellular locations and specific intracellular chemical interactions determine the biological function. An in-situ nondestructive characterization of the complicated chemical processes (like e.g. apoptosis) is the goal of our study. Here, we present the results of simultaneous and three-dimensional imaging of double organelles (nucleus and membrane) in single HeLa cells by means of either labelled or label-free surface-enhanced Raman spectroscopy (SERS). This combination of imaging with and without labels is not possible when using fluorescence microscopy. The SERS technique is used for a stereoscopic description of the intrinsic chemical nature of nuclei and the precise localization of folate (FA) and luteinizing hormone-releasing hormone (LHRH) on the membrane under highly confocal conditions. We also report on the time-dependent changes of cell nuclei as well as membrane receptor proteins during apoptosis analyzed by statistical multivariate methods. The multiplex three-dimensional SERS imaging technique allows for both temporal (real time) and spatial (multiple organelles and molecules in three-dimensional space) live-cell imaging and therefore provides a new and attractive 2D/3D tracing method in biomedicine on subcellular level. PMID:26781186

  1. Combined Labelled and Label-free SERS Probes for Triplex Three-dimensional Cellular Imaging

    PubMed Central

    Chen, Yong; Bai, Xiangru; Su, Le; Du, Zhanwei; Shen, Aiguo; Materny, Arnulf; Hu, Jiming

    2016-01-01

    Cells are complex chemical systems, where the molecular composition at different cellular locations and specific intracellular chemical interactions determine the biological function. An in-situ nondestructive characterization of the complicated chemical processes (like e.g. apoptosis) is the goal of our study. Here, we present the results of simultaneous and three-dimensional imaging of double organelles (nucleus and membrane) in single HeLa cells by means of either labelled or label-free surface-enhanced Raman spectroscopy (SERS). This combination of imaging with and without labels is not possible when using fluorescence microscopy. The SERS technique is used for a stereoscopic description of the intrinsic chemical nature of nuclei and the precise localization of folate (FA) and luteinizing hormone-releasing hormone (LHRH) on the membrane under highly confocal conditions. We also report on the time-dependent changes of cell nuclei as well as membrane receptor proteins during apoptosis analyzed by statistical multivariate methods. The multiplex three-dimensional SERS imaging technique allows for both temporal (real time) and spatial (multiple organelles and molecules in three-dimensional space) live-cell imaging and therefore provides a new and attractive 2D/3D tracing method in biomedicine on subcellular level. PMID:26781186

  2. Axisymmetric and three dimensional flow modeling within thermal vapor compressors

    NASA Astrophysics Data System (ADS)

    Sharifi, Navid

    2013-10-01

    Thermal vapor compressor (TVC) is a device for compressing vapor in water-steam cycles and frequently used in desalination systems. Large amounts of useless vapor can be compressed by this device and the efficiency of a desalination unit is effectively enhanced through this process. Motive steam is injected into the TVC through a convergent-divergent nozzle and accelerated to supersonic velocities. The low pressure steam is entrained at the upstream zone and mixed with this highly compressible motive flow within the TVC. In the current study, the flow field of an experimental TVC is scrutinized in both axisymmetric and three-dimensional approaches and compared with experimental measurements. Since the steam collector at the suction surface of the TVC has a curved shape and may undermine the symmetry of the flow on either side of the central axis, the second objective of this study is to reveal the deviation of the symmetric assumption from the real non-symmetric condition of entering steam flow into the TVC. Results show that the presence of a bending at the inlet side has approximately negligible effects on the mixing phenomenon and the flow remains symmetric around the central axis. Hence, there is no need to consider the collector geometry in further simulations and the performance parameters of the TVC would be sufficiently obtained through an axisymmetric method with a substantial reduction in the computational cost and time.

  3. Combinatorial thin film composition mapping using three dimensional deposition profiles.

    PubMed

    Suram, Santosh K; Zhou, Lan; Becerra-Stasiewicz, Natalie; Kan, Kevin; Jones, Ryan J R; Kendrick, Brian M; Gregoire, John M

    2015-03-01

    Many next-generation technologies are limited by material performance, leading to increased interest in the discovery of advanced materials using combinatorial synthesis, characterization, and screening. Several combinatorial synthesis techniques, such as solution based methods, advanced manufacturing, and physical vapor deposition, are currently being employed for various applications. In particular, combinatorial magnetron sputtering is a versatile technique that provides synthesis of high-quality thin film composition libraries. Spatially addressing the composition of these thin films generally requires elemental quantification measurements using techniques such as energy-dispersive X-ray spectroscopy or X-ray fluorescence spectroscopy. Since these measurements are performed ex-situ and post-deposition, they are unable to provide real-time design of experiments, a capability that is required for rapid synthesis of a specific composition library. By using three quartz crystal monitors attached to a stage with translational and rotational degrees of freedom, we measure three-dimensional deposition profiles of deposition sources whose tilt with respect to the substrate is robotically controlled. We exhibit the utility of deposition profiles and tilt control to optimize the deposition geometry for specific combinatorial synthesis experiments. PMID:25832242

  4. Combinatorial thin film composition mapping using three dimensional deposition profiles

    NASA Astrophysics Data System (ADS)

    Suram, Santosh K.; Zhou, Lan; Becerra-Stasiewicz, Natalie; Kan, Kevin; Jones, Ryan J. R.; Kendrick, Brian M.; Gregoire, John M.

    2015-03-01

    Many next-generation technologies are limited by material performance, leading to increased interest in the discovery of advanced materials using combinatorial synthesis, characterization, and screening. Several combinatorial synthesis techniques, such as solution based methods, advanced manufacturing, and physical vapor deposition, are currently being employed for various applications. In particular, combinatorial magnetron sputtering is a versatile technique that provides synthesis of high-quality thin film composition libraries. Spatially addressing the composition of these thin films generally requires elemental quantification measurements using techniques such as energy-dispersive X-ray spectroscopy or X-ray fluorescence spectroscopy. Since these measurements are performed ex-situ and post-deposition, they are unable to provide real-time design of experiments, a capability that is required for rapid synthesis of a specific composition library. By using three quartz crystal monitors attached to a stage with translational and rotational degrees of freedom, we measure three-dimensional deposition profiles of deposition sources whose tilt with respect to the substrate is robotically controlled. We exhibit the utility of deposition profiles and tilt control to optimize the deposition geometry for specific combinatorial synthesis experiments.

  5. A DETERMINISTIC METHOD FOR TRANSIENT, THREE-DIMENSIONAL NUETRON TRANSPORT

    SciTech Connect

    Goluoglu, S.; Bentley, C.; Demeglio, R.; Dunn, M.; Norton, K.; Pevey, R.; Suslov, I.; Dodds, H. L.

    1998-01-14

    A deterministic method for solving the time-dependent, three-dimensional Boltzmam transport equation with explicit representation of delayed neutrons has been developed and evaluated. The methodology used in this study for the time variable of the neutron flux is known as the improved quasi-static (IQS) method. The position, energy, and angle-dependent neutron flux is computed deterministically by using the three-dimensional discrete ordinates code TORT. This paper briefly describes the methodology and selected results. The code developed at the University of Tennessee based on this methodology is called TDTORT. TDTORT can be used to model transients involving voided and/or strongly absorbing regions that require transport theory for accuracy. This code can also be used to model either small high-leakage systems, such as space reactors, or asymmetric control rod movements. TDTORT can model step, ramp, step followed by another step, and step followed by ramp type perturbations. It can also model columnwise rod movement can also be modeled. A special case of columnwise rod movement in a three-dimensional model of a boiling water reactor (BWR) with simple adiabatic feedback is also included. TDTORT is verified through several transient one-dimensional, two-dimensional, and three-dimensional benchmark problems. The results show that the transport methodology and corresponding code developed in this work have sufficient accuracy and speed for computing the dynamic behavior of complex multidimensional neutronic systems.

  6. A deterministic method for transient, three-dimensional neutron transport

    SciTech Connect

    Goluoglu, S.; Bentley, C.; DeMeglio, R.; Dunn, M.; Norton, K.; Pevey, R.; Suslov, I.; Dodds, H.L.

    1998-05-01

    A deterministic method for solving the time-dependent, three-dimensional Boltzmann transport equation with explicit representation of delayed neutrons has been developed and evaluated. The methodology used in this study for the time variable of the neutron flux is known as the improved quasi-static (IQS) method. The position, energy, and angle-dependent neutron flux is computed deterministically by using the three-dimensional discrete ordinates code TORT. This paper briefly describes the methodology and selected results. The code developed at the University of Tennessee based on this methodology is called TDTORT. TDTORT can be used to model transients involving voided and/or strongly absorbing regions that require transport theory for accuracy. This code can also be used to model either small high-leakage systems, such as space reactors, or asymmetric control rod movements. TDTORT can model step, ramp, step followed by another step, and step followed by ramp type perturbations. It can also model columnwise rod movement. A special case of columnwise rod movement in a three-dimensional model of a boiling water reactor (BWR) with simple adiabatic feedback is also included. TDTORT is verified through several transient one-dimensional, two-dimensional, and three-dimensional benchmark problems. The results show that the transport methodology and corresponding code developed in this work have sufficient accuracy and speed for computing the dynamic behavior of complex multi-dimensional neutronic systems.

  7. Three-dimensionally assembled gold nanostructures for plasmonic biosensors.

    PubMed

    Guo, Longhua; Chen, Guonan; Kim, Dong-Hwan

    2010-06-15

    Three-dimensional gold nanoarchitecture was fabricated by layer-by-layer (LbL) deposition of gold nanoparticles (AuNPs) and multiwalled carbon nanotubes (MWCNTs) on a glass substrate for a highly sensitive plasmonic biosensor using a conventional UV-vis instrument. Carboxyl-functionalized MWCNTs were reacted with 3-mercaptopropyltriethoxysilane (MPTES) to introduce multiple thiol groups onto MWCNTs. A self-assembled monolayer (SAM) of AuNPs on a glass chip was sequentially dipped into MPTES-functionalized MWCNTs (MWCNT-Si-SH) and AuNPs to form multilayers of AuNPs on MWCNTs. Such three-dimensionally assembled AuNPs provided a large surface area and multiple binding sites within a few steps of modification and microporous structures of multilayered MWCNTs to allow a high accessibility of target molecules. It was shown that the bulk refractive index (RI) sensitivity of these multilayered AuNPs (three-dimensional chip) appeared to be 5.6 times better than that of a monolayer of AuNPs on a glass chip (two-dimensional chip). The three-dimensional chips were further used for a biomolecular binding study, showing a detection limit as low as 0.5 nM for streptavidin and 3.33 nM for anti-human serum albumin (HSA), both of which were approximately 20 times higher than the sensitivity of the two-dimensional chips. PMID:20469841

  8. Real-time modeling of complex atmospheric releases in urban areas

    SciTech Connect

    Baskett, R.L.; Ellis, J.S.; Sullivan, T.J.

    1994-08-01

    If a nuclear installation in or near an urban area has a venting, fire, or explosion, airborne radioactivity becomes the major concern. Dispersion models are the immediate tool for estimating the dose and contamination. Responses in urban areas depend on knowledge of the amount of the release, representative meteorological data, and the ability of the dispersion model to simulate the complex flows as modified by terrain or local wind conditions. A centralized dispersion modeling system can produce realistic assessments of radiological accidents anywhere in a country within several minutes if it is computer-automated. The system requires source-term, terrain, mapping and dose-factor databases, real-time meteorological data acquisition, three-dimensional atmospheric transport and dispersion models, and experienced staff. Experience with past responses in urban areas by the Atmospheric Release Advisory Capability (ARAC) program at Lawrence Livermore National Laboratory illustrate the challenges for three-dimensional dispersion models.

  9. Growing Three-Dimensional Cocultures Of Cells

    NASA Technical Reports Server (NTRS)

    Wolf, David A.; Goodwin, Thomas J.

    1995-01-01

    Laboratory process provides environmental conditions favoring simultaneous growth of cocultures of mammalian cells of more than one type. Cultures become three-dimensional tissuelike assemblies serving as organoid models of differentiation of cells. Process used, for example, to study growth of human colon cancers, starting from mixtures of normal colonic fibroblasts and partially differentiated colon adenocarcinoma cells.

  10. Three-dimensional colorimetric assay assemblies

    DOEpatents

    Charych, Deborah; Reichert, Anke

    2001-01-01

    A direct assay is described using novel three-dimensional polymeric assemblies which change from a blue to red color when exposed to an analyte, in one case a flue virus. The assemblies are typically in the form of liposomes which can be maintained in a suspension, and show great intensity in their color changes. Their method of production is also described.

  11. Three-Dimensional Printing Surgical Applications

    PubMed Central

    Griffin, Michelle F.; Butler, Peter E.

    2015-01-01

    Introduction: Three-dimensional printing, a technology used for decades in the industrial field, gains a lot of attention in the medical field for its potential benefits. With advancement of desktop printers, this technology is accessible and a lot of research is going on in the medical field. Objective: To evaluate its application in surgical field, which may include but not limited to surgical planning, surgical education, implants, and prosthesis, which are the focus of this review. Methods: Research was conducted by searching PubMed, Web of science, and other reliable sources. We included original articles and excluded articles based on animals, those more than 10 years old, and those not in English. These articles were evaluated, and relevant studies were included in this review. Discussion: Three-dimensional printing shows a potential benefit in surgical application. Printed implants were used in patient in a few cases and show successful results; however, longer follow-up and more trials are needed. Surgical and medical education is believed to be more efficient with this technology than the current practice. Printed surgical instrument and surgical planning are also believed to improve with three-dimensional printing. Conclusion: Three-dimensional printing can be a very powerful tool in the near future, which can aid the medical field that is facing a lot of challenges and obstacles. However, despite the reported results, further research on larger samples and analytical measurements should be conducted to ensure this technology's impact on the practice. PMID:26301002

  12. Three-Dimensional Pointers for Stereoscopic Projection.

    ERIC Educational Resources Information Center

    Hayman, H. J. G.

    1984-01-01

    Because class size often limits student opportunity to handle individual models, teachers use stereoscopic projections to demonstrate structural features. Describes three-dimensional pointers for use with different projection systems so teachers can indicate a particular atom or bond to entire classes, avoiding the perspective problems inherent in…

  13. Modification of a commercial thromboelastography instrument to measure coagulation dynamics with three-dimensional biomaterials.

    PubMed

    Hawker, Morgan J; Olver, Christine S; Fisher, Ellen R

    2016-06-01

    Three-dimensional synthetic constructs with complex geometries have immense potential for use in a multitude of blood-contacting applications. Understanding coagulation phenomena is arguably the most critical aspect for applications involving synthetic biomaterials; however, real-time evaluation of the clot formation while interfacing with these materials is difficult to achieve in a reproducible and robust manner. Here, work representing first steps toward addressing this deficit is presented, wherein modified consumables for a clinical instrument (a Thromboelastograph(®)) have been fabricated. Thromboelastography (TEG) measures viscoelastic properties throughout clot formation and therefore provides clinically relevant coagulation measurements in real time (i.e., kinetics and strength of clot formation). Through our modification, TEG consumables can readily accommodate three-dimensional materials (e.g., those for regenerative tissue applications). The authors performed proof-of-concept experiments using polymer scaffolds with a range of surface properties and demonstrated that variations in surface properties resulted in differences in blood plasma coagulation dynamics. For example, the maximum rate of thrombus generation ranged from 22.2 ± 2.2 (dyn/cm(2))/s for fluorocarbon coated scaffolds to 8.7 ± 1.0 (dyn/cm(2))/s for nitrogen-containing scaffolds. Through this work, the ability to make real-time coagulation activity measurements during constant coagulation factor interface with biomedically relevant materials is demonstrated. PMID:27126596

  14. Real time adaptive filtering for digital X-ray applications.

    PubMed

    Bockenbach, Olivier; Mangin, Michel; Schuberth, Sebastian

    2006-01-01

    Over the last decade, many methods for adaptively filtering a data stream have been proposed. Those methods have applications in two dimensional imaging as well as in three dimensional image reconstruction. Although the primary objective of this filtering technique is to reduce the noise while avoiding to blur the edges, diagnostic, automated segmentation and surgery show a growing interest in enhancing the features contained in the image flow. Most of the methods proposed so far emerged from thorough studies of the physics of the considered modality and therefore show only a marginal capability to be extended across modalities. Moreover, adaptive filtering belongs to the family of processing intensive algorithms. Existing technology has often driven to simplifications and modality specific optimization to sustain the expected performances. In the specific case of real time digital X-ray as used surgery, the system has to sustain a throughput of 30 frames per second. In this study, we take a generalized approach for adaptive filtering based on multiple oriented filters. Mapping the filtering part to the embedded real time image processing while a user/application defined adaptive recombination of the filter outputs allow to change the smoothing and edge enhancement properties of the filter without changing the oriented filter parameters. We have implemented the filtering on a Cell Broadband Engine processor and the adaptive recombination on an off-the-shelf PC, connected via Gigabit Ethernet. This implementation is capable of filtering images of 5122 pixels at a throughput in excess of 40 frames per second while allowing to change the parameters in real time. PMID:17354937

  15. Making real-time reactive systems reliable

    NASA Technical Reports Server (NTRS)

    Marzullo, Keith; Wood, Mark

    1990-01-01

    A reactive system is characterized by a control program that interacts with an environment (or controlled program). The control program monitors the environment and reacts to significant events by sending commands to the environment. This structure is quite general. Not only are most embedded real time systems reactive systems, but so are monitoring and debugging systems and distributed application management systems. Since reactive systems are usually long running and may control physical equipment, fault tolerance is vital. The research tries to understand the principal issues of fault tolerance in real time reactive systems and to build tools that allow a programmer to design reliable, real time reactive systems. In order to make real time reactive systems reliable, several issues must be addressed: (1) How can a control program be built to tolerate failures of sensors and actuators. To achieve this, a methodology was developed for transforming a control program that references physical value into one that tolerates sensors that can fail and can return inaccurate values; (2) How can the real time reactive system be built to tolerate failures of the control program. Towards this goal, whether the techniques presented can be extended to real time reactive systems is investigated; and (3) How can the environment be specified in a way that is useful for writing a control program. Towards this goal, whether a system with real time constraints can be expressed as an equivalent system without such constraints is also investigated.

  16. Three-dimensional in vivo imaging by a handheld dual-axes confocal microscope

    PubMed Central

    Ra, Hyejun; Piyawattanametha, Wibool; Mandella, Michael J.; Hsiung, Pei-Lin; Hardy, Jonathan; Wang, Thomas D.; Contag, Christopher H.; Kino, Gordon S.; Solgaard, Olav

    2008-01-01

    We present a handheld dual-axes confocal microscope that is based on a two-dimensional microelectromechanical systems (MEMS) scanner. It performs reflectance and fluorescence imaging at 488 nm wavelength, with three-dimensional imaging capability. The fully packaged microscope has a diameter of 10 mm and acquires images at 4 Hz frame rate with a maximum field of view of 400 μm × 260 μm. The transverse and axial resolutions of the handheld probe are 1.7 μm and 5.8 μm, respectively. Capability to perform real time small animal imaging is demonstrated in vivo in transgenic mice. PMID:18545427

  17. Technical aspects of a demonstration tape for three-dimensional sound displays

    NASA Technical Reports Server (NTRS)

    Begault, Durand R.; Wenzel, Elizabeth M.

    1990-01-01

    This document was developed to accompany an audio cassette that demonstrates work in three-dimensional auditory displays, developed at the Ames Research Center Aerospace Human Factors Division. It provides a text version of the audio material, and covers the theoretical and technical issues of spatial auditory displays in greater depth than on the cassette. The technical procedures used in the production of the audio demonstration are documented, including the methods for simulating rotorcraft radio communication, synthesizing auditory icons, and using the Convolvotron, a real-time spatialization device.

  18. The ALMA Real Time Control System

    NASA Astrophysics Data System (ADS)

    Kern, Jeffrey S.; Juerges, Thomas A.; Marson, Ralph G.

    2009-01-01

    The Atacama Large Millimeter Array (ALMA) is a revolutionary millimeter and submillimeter array being developed on the Atacama plateau of northern Chile. An international partnership lead by NRAO, ESO, and NAOJ this powerful and flexible telescope will provide unprecedented observations of this relatively unexplored frequency range. The control subsystem for the Atacama Large Millimeter Array must coordinate the monitor and control of at least sixty six antennas (in four different styles), two correlators, and all of the ancillary equipment (samplers, local oscillators, front ends, etc.). This equipment will be spread over tens of kilometers and operated remotely. Operation of the array requires a robust, scalable, and maintainable real time control system. The real time control system is responsible for monitoring and control of any devices where there are fixed deadlines. Examples in the ALMA context are antenna pointing and fringe tracking. Traditionally the real time portion of a large software system is an intricate and error prone portion of the software. As a result the real time portion is very expensive in terms of effort expended both during construction and during maintenance phases of a project. The ALMA real time control system uses a Linux based real time operating system to interact with the hardware and the CORBA based ALMA Common Software to communicate in the distributed computing environment. Mixing the requirements of real time computing and the non-deterministic CORBA middleware has produced an interesting design. We discuss the architecture, design, and implementation of the ALMA real time control system. Highlight some lessons learned along the way, and justify our assertion that this should be the last large scale real time control system in radio astronomy.

  19. Real-time monitoring of landslides

    USGS Publications Warehouse

    Reid, Mark E.; LaHusen, Richard G.; Baum, Rex L.; Kean, Jason W.; Schulz, William H.; Highland, Lynn M.

    2012-01-01

    Landslides cause fatalities and property damage throughout the Nation. To reduce the impact from hazardous landslides, the U.S. Geological Survey develops and uses real-time and near-real-time landslide monitoring systems. Monitoring can detect when hillslopes are primed for sliding and can provide early indications of rapid, catastrophic movement. Continuous information from up-to-the-minute or real-time monitoring provides prompt notification of landslide activity, advances our understanding of landslide behavior, and enables more effective engineering and planning efforts.

  20. Real-Time Monitoring of Active Landslides

    USGS Publications Warehouse

    Reid, Mark E.; LaHusen, Richard G.; Ellis, William L.

    1999-01-01

    Landslides threaten lives and property in every State in the Nation. To reduce the risk from active landslides, the U.S. Geological Survey (USGS) develops and uses real-time landslide monitoring systems. Monitoring can detect early indications of rapid, catastrophic movement. Up-to-the-minute or real-time monitoring provides immediate notification of landslide activity, potentially saving lives and property. Continuous information from real-time monitoring also provides a better understanding of landslide behavior, enabling engineers to create more effective designs for halting landslide movement.

  1. Real time sensor for therapeutic radiation delivery

    DOEpatents

    Bliss, Mary; Craig, Richard A.; Reeder, Paul L.

    1998-01-01

    The invention is a real time sensor for therapeutic radiation. A probe is placed in or near the patient that senses in real time the dose at the location of the probe. The strength of the dose is determined by either an insertion or an exit probe. The location is determined by a series of vertical and horizontal sensing elements that gives the operator a real time read out dose location relative to placement of the patient. The increased accuracy prevents serious tissue damage to the patient by preventing overdose or delivery of a dose to a wrong location within the body.

  2. Real time sensor for therapeutic radiation delivery

    DOEpatents

    Bliss, M.; Craig, R.A.; Reeder, P.L.

    1998-01-06

    The invention is a real time sensor for therapeutic radiation. A probe is placed in or near the patient that senses in real time the dose at the location of the probe. The strength of the dose is determined by either an insertion or an exit probe. The location is determined by a series of vertical and horizontal sensing elements that gives the operator a real time read out dose location relative to placement of the patient. The increased accuracy prevents serious tissue damage to the patient by preventing overdose or delivery of a dose to a wrong location within the body. 14 figs.

  3. The Current Role of Three-Dimensional Printing in Plastic Surgery.

    PubMed

    Kamali, Parisa; Dean, David; Skoracki, Roman; Koolen, Pieter G L; Paul, Marek A; Ibrahim, Ahmed M S; Lin, Samuel J

    2016-03-01

    Since the advent of three-dimensional printing in the 1980s, it has become possible to produce physical objects from digital files and create three-dimensional objects by adding one layer at a time following a predetermined pattern. Because of the continued development of inexpensive and easy-to-use three-dimensional printers and bioprinting, this technique has gained more momentum over time, especially in the field of medicine. This article reviews the current and possible future application of three-dimensional printing technology within the field of plastic and reconstructive surgery. PMID:26910689

  4. Real Time Sound Field Simulator Using Field Programmable Gate Array Device

    NASA Astrophysics Data System (ADS)

    Tsuchiya, T.; Sugawara, E.; Inoguchi, Y.

    Possibility of real time simulator of three-dimensional acoustic field in the time domain is discussed. Based on the discrete Huygens' model (DHM), a digital equivalent circuit is developed. DHM elements are described by hardware description language (HDL) in the fixed-point arithmetic. It is estimated that the real time simulation of 1 m3 sound field is possible using ten-odd FPGA chips, while the CPU speed of 52 TFLOPS is required using the high performance computer. It is shown that data length of 28 bits is required for the practical accuracy. Based on FPGA-DHM, the real time simulator named "Silicon Concert Hall" may come true in the near future.

  5. Monitoring apoptosis in real time.

    PubMed

    Green, Allan M; Steinmetz, Neil D

    2002-01-01

    clinical responses. A single site study in 15 subjects with 1-year follow-up has suggested that increased posttreatment Tc 99m-rh annexin uptake is associated with improved time to progression of disease and survival time. In vivo imaging of cell death may have the potential to improve the treatment of cancer patients by allowing rapid, objective, patient-by-patient assessment of the efficacy of tumor cell killing. PMID:11999952

  6. Analysis of real-time vibration data

    USGS Publications Warehouse

    Safak, E.

    2005-01-01

    In recent years, a few structures have been instrumented to provide continuous vibration data in real time, recording not only large-amplitude motions generated by extreme loads, but also small-amplitude motions generated by ambient loads. The main objective in continuous recording is to track any changes in structural characteristics, and to detect damage after an extreme event, such as an earthquake or explosion. The Fourier-based spectral analysis methods have been the primary tool to analyze vibration data from structures. In general, such methods do not work well for real-time data, because real-time data are mainly composed of ambient vibrations with very low amplitudes and signal-to-noise ratios. The long duration, linearity, and the stationarity of ambient data, however, allow us to utilize statistical signal processing tools, which can compensate for the adverse effects of low amplitudes and high noise. The analysis of real-time data requires tools and techniques that can be applied in real-time; i.e., data are processed and analyzed while being acquired. This paper presents some of the basic tools and techniques for processing and analyzing real-time vibration data. The topics discussed include utilization of running time windows, tracking mean and mean-square values, filtering, system identification, and damage detection.

  7. Real-time smart fluorescence sensor platform

    NASA Astrophysics Data System (ADS)

    Dickens, Jason E.; Vaughn, Mike S.; Taylor, Mervin; Ponstingl, Mike

    2011-06-01

    A novel compact LED array based light induced fluorescence (LIF) sensor has been developed for real-time in-line monitoring of intrinsic fluorophores in the solid and liquid state. The sensor is essential for on-the-spot, routine, and cost effective real-time analysis. The sensor is designed to provide real-time emission response along with various smart sensing parameters to ensure real-time measurement quality that is required for regulated GMP process monitoring applications. This work describes a LIF sensor tailored for solid-phase fluorometry. Fundamental figures of merit, excitation overexposure and smart sensing features required for modern process monitoring and control are discussed within the context of pharmaceutical solid-phase manufacturing and similar applications.

  8. Interferometer real time control development for SIM

    NASA Astrophysics Data System (ADS)

    Bell, Charles E.

    2003-02-01

    Real Time Control (RTC) for the Space Interferometry Mission will build on the real time core interferometer control technology under development at JPL since the mid 1990s, with heritage from the ground based MKII and Palomar Testbed Interferometer projects developed in the late '80s and early '90s. The core software and electronics technology for SIM interferometer real time control is successfully operating on several SIM technology demonstration testbeds, including the Real-time Interferometer Control System Testbed, System Testbed-3, and the Microarcsecond Metrology testbed. This paper provides an overview of the architecture, design, integration, and test of the SIM flight interferometer real time control to meet challenging flight system requirements for the high processor throughput, low-latency interconnect, and precise synchronization to support microarcsecond-level astrometric measurements for greater than five years at 1 AU in Earth-trailing orbit. The electronics and software architecture of the interferometer real time control core and its adaptation to a flight design concept are described. Control loops for pointing and pathlength control within each of four flight interferometers and for coordination of control and data across interferometers are illustrated. The nature of onboard data processing to fit average downlink rates while retaining post-processed astrometric measurement precision and accuracy is also addressed. Interferometer flight software will be developed using a software simulation environment incorporating models of the metrology and starlight sensors and actuators to close the real time control loops. RTC flight software and instrument flight electronics will in turn be integrated utilizing the same simulation architecture for metrology and starlight component models to close real time control loops and verify RTC functionality and performance prior to delivery to flight interferometer system integration at Lockheed Martin

  9. Real-time interferometric synthetic aperture microscopy.

    PubMed

    Ralston, Tyler S; Marks, Daniel L; Carney, P Scott; Boppart, Stephen A

    2008-02-18

    An interferometric synthetic aperture microscopy (ISAM) system design with real-time 2D cross-sectional processing is described in detail. The system can acquire, process, and display the ISAM reconstructed images at frame rates of 2.25 frames per second for 512 X 1024 pixel images. This system provides quantitatively meaningful structural information from previously indistinguishable scattering intensities and provides proof of feasibility for future real-time ISAM systems. PMID:18542337

  10. Processing PCM Data in Real Time

    NASA Technical Reports Server (NTRS)

    Wissink, T. L.

    1982-01-01

    Novel hardware configuration makes it possible for Space Shuttle launch processing system to monitor pulse-code-modulated data in real time. Using two microprogramable "option planes," incoming PCM data are monitored for changes at rate of one frame of data (80 16-bit words) every 10 milliseconds. Real-time PCM processor utilizes CPU in mini-computer and CPU's in two option planes.

  11. Real-time scheduling using minimum search

    NASA Technical Reports Server (NTRS)

    Tadepalli, Prasad; Joshi, Varad

    1992-01-01

    In this paper we consider a simple model of real-time scheduling. We present a real-time scheduling system called RTS which is based on Korf's Minimin algorithm. Experimental results show that the schedule quality initially improves with the amount of look-ahead search and tapers off quickly. So it sppears that reasonably good schedules can be produced with a relatively shallow search.

  12. The LAA real-time benchmarks

    SciTech Connect

    Block, R.K.; Krischer, W.; Lone, S.

    1989-04-01

    In the context of the LAA detector development program a subgroup Real Time Data Processing has tackled the problem of intelligent triggering. The main goal of this group is to show how fast digital devices, implemented as custom-made or commercial processors, can execute some basic algorithms, and how they can be embedded in the data flow between detector readout components and fully programmable commercial processors, which are expected to be the final data processing filter in real time.

  13. Transformation equation in three-dimensional photoelasticity.

    PubMed

    Ainola, Leo; Aben, Hillar

    2006-03-01

    Optical phenomena that occur when polarized light passes through an inhomogeneous birefringent medium are complicated, especially when the principal directions of the dielectric tensor rotate on the light ray. This case is typical in three-dimensional photoelasticity, in particular in integrated photoelasticity by stress analysis on the basis of measured polarization transformations. Analysis of polarization transformations in integrated photoelasticity has been based primarily on a system of two first-order differential equations. Using a transformed coordinate in the direction of light propagation, we have derived a single fourth-order differential equation of three-dimensional photoelasticity. For the case of uniform rotation of the principal directions we have obtained an analytical solution. PMID:16539073

  14. Three-dimensional visualization of a qutrit

    NASA Astrophysics Data System (ADS)

    Kurzyński, Paweł; Kołodziejski, Adrian; Laskowski, Wiesław; Markiewicz, Marcin

    2016-06-01

    We present a surprisingly simple three-dimensional Bloch sphere representation of a qutrit, i.e., a single three-level quantum system. We start with a symmetric state of a two-qubit system and relate it to the spin-1 representation. Using this representation we associate each qutrit state with a three-dimensional vector a and a metric tensor Γ ̂ which satisfy a .Γ ̂.a ≤1 . This resembles the well known condition for qubit Bloch vectors in which case Γ ̂=1 . In our case the vector a corresponds to spin-1 polarization, whereas the tensor Γ ̂ is a function of polarization uncertainties. Alternatively, a is a local Bloch vector of a symmetric two-qubit state and Γ ̂ is a function of the corresponding correlation tensor.

  15. Three dimensional fabrication at small size scales

    PubMed Central

    Leong, Timothy G.; Zarafshar, Aasiyeh M.; Gracias, David H.

    2010-01-01

    Despite the fact that we live in a three-dimensional (3D) world and macroscale engineering is 3D, conventional sub-mm scale engineering is inherently two-dimensional (2D). New fabrication and patterning strategies are needed to enable truly three-dimensionally-engineered structures at small size scales. Here, we review strategies that have been developed over the last two decades that seek to enable such millimeter to nanoscale 3D fabrication and patterning. A focus of this review is the strategy of self-assembly, specifically in a biologically inspired, more deterministic form known as self-folding. Self-folding methods can leverage the strengths of lithography to enable the construction of precisely patterned 3D structures and “smart” components. This self-assembling approach is compared with other 3D fabrication paradigms, and its advantages and disadvantages are discussed. PMID:20349446

  16. Simulation of complex three-dimensional flows

    NASA Technical Reports Server (NTRS)

    Diewert, G. S.; Rothmund, H. J.; Nakahashi, K.

    1985-01-01

    The concept of splitting is used extensively to simulate complex three dimensional flows on modern computer architectures. Used in all aspects, from initial grid generation to the determination of the final converged solution, splitting is used to enhance code vectorization, to permit solution driven grid adaption and grid enrichment, to permit the use of concurrent processing, and to enhance data flow through hierarchal memory systems. Three examples are used to illustrate these concepts to complex three dimensional flow fields: (1) interactive flow over a bump; (2) supersonic flow past a blunt based conical afterbody at incidence to a free stream and containing a centered propulsive jet; and (3) supersonic flow past a sharp leading edge delta wing at incidence to the free stream.

  17. Three-dimensional bio-printing.

    PubMed

    Gu, Qi; Hao, Jie; Lu, YangJie; Wang, Liu; Wallace, Gordon G; Zhou, Qi

    2015-05-01

    Three-dimensional (3D) printing technology has been widely used in various manufacturing operations including automotive, defence and space industries. 3D printing has the advantages of personalization, flexibility and high resolution, and is therefore becoming increasingly visible in the high-tech fields. Three-dimensional bio-printing technology also holds promise for future use in medical applications. At present 3D bio-printing is mainly used for simulating and reconstructing some hard tissues or for preparing drug-delivery systems in the medical area. The fabrication of 3D structures with living cells and bioactive moieties spatially distributed throughout will be realisable. Fabrication of complex tissues and organs is still at the exploratory stage. This review summarize the development of 3D bio-printing and its potential in medical applications, as well as discussing the current challenges faced by 3D bio-printing. PMID:25921944

  18. Three-dimensional imaging modalities in endodontics

    PubMed Central

    Mao, Teresa

    2014-01-01

    Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome. PMID:25279337

  19. Three-dimensional adjustment of trilateration data

    NASA Technical Reports Server (NTRS)

    Sung, L.-Y.; Jackson, D. D.

    1985-01-01

    The three-dimensional locations of the monuments in the USGS Hollister trilateration network were adjusted to fit line length observations observed in 1977, using a Bayesian approach, and incorporating prior elevation estimates as data in the adjustment procedure. No significant discrepancies in the measured line lengths were found, but significant elevation adjustments (up to 1.85 m) were needed to fit the length data.

  20. Three-dimensional Lorentz-violating action

    NASA Astrophysics Data System (ADS)

    Nascimento, J. R.; Petrov, A. Yu.; Wotzasek, C.; Zarro, C. A. D.

    2014-03-01

    We demonstrate the generation of the three-dimensional Chern-Simons-like Lorentz-breaking "mixed" quadratic action via an appropriate Lorentz-breaking coupling of vector and scalar fields to the spinor field and study some features of the scalar QED with such a term. We show that the same term emerges through a nonperturbative method, namely the Julia-Toulouse approach of condensation of charges and defects.

  1. Three-dimensional display of document set

    DOEpatents

    Lantrip, David B.; Pennock, Kelly A.; Pottier, Marc C.; Schur, Anne; Thomas, James J.; Wise, James A.; York, Jeremy

    2009-06-30

    A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.

  2. Three-dimensional display of document set

    DOEpatents

    Lantrip, David B.; Pennock, Kelly A.; Pottier, Marc C.; Schur, Anne; Thomas, James J.; Wise, James A.

    2006-09-26

    A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may e transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.

  3. Three-dimensional display of document set

    DOEpatents

    Lantrip, David B [Oxnard, CA; Pennock, Kelly A [Richland, WA; Pottier, Marc C [Richland, WA; Schur, Anne [Richland, WA; Thomas, James J [Richland, WA; Wise, James A [Richland, WA

    2001-10-02

    A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.

  4. Three-Dimensional Dispaly Of Document Set

    DOEpatents

    Lantrip, David B.; Pennock, Kelly A.; Pottier, Marc C.; Schur, Anne; Thomas, James J.; Wise, James A.

    2003-06-24

    A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.

  5. Stress tensor correlators in three dimensional gravity

    NASA Astrophysics Data System (ADS)

    Bagchi, Arjun; Grumiller, Daniel; Merbis, Wout

    2016-03-01

    We calculate holographically arbitrary n -point correlators of the boundary stress tensor in three-dimensional Einstein gravity with negative or vanishing cosmological constant. We provide explicit expressions up to 5-point (connected) correlators and show consistency with the Galilean conformal field theory Ward identities and recursion relations of correlators, which we derive. This provides a novel check of flat space holography in three dimensions.

  6. Three-dimensional ballistocardiography in weightlessness

    NASA Technical Reports Server (NTRS)

    Scano, A.

    1981-01-01

    An experiment is described the aim of which is to record a three dimensional ballistocardiogram under the condition of weightlessness and to compare it with tracings recorded on the same subject on the ground as a means of clarifying the meaning of ballistocardiogram waves in different physiological and perphaps pathological conditions. Another purpose is to investigate cardiovascular and possibly fluid adaptations to weightlessness from data collected almost simultaneously on the same subjects during the other cardiovascular during the other cardiovascular and metabolic experiments.

  7. Three-dimensional motor schema based navigation

    NASA Technical Reports Server (NTRS)

    Arkin, Ronald C.

    1989-01-01

    Reactive schema-based navigation is possible in space domains by extending the methods developed for ground-based navigation found within the Autonomous Robot Architecture (AuRA). Reformulation of two dimensional motor schemas for three dimensional applications is a straightforward process. The manifold advantages of schema-based control persist, including modular development, amenability to distributed processing, and responsiveness to environmental sensing. Simulation results show the feasibility of this methodology for space docking operations in a cluttered work area.

  8. Generating Three-Dimensional Grids About Anything

    NASA Technical Reports Server (NTRS)

    Sorenson, Reese L.

    1991-01-01

    Three-Dimensional Grids About Anything by Poisson's Equation (3DGRAPE) computer program designed to make computational grids in or about almost any shape. Generated by solution of Poisson's differential equations in three dimensions. Program automatically finds its own values for inhomogeneous terms giving near-orthogonality and controlled grid-cell height at boundaries. Grids generated applied to both viscous and inviscid aerodynamic problems, and to problems in other areas of fluid dynamics. Written in 100 percent FORTRAN 77.

  9. Mineralized three-dimensional bone constructs

    NASA Technical Reports Server (NTRS)

    Clarke, Mark S. F. (Inventor); Sundaresan, Alamelu (Inventor); Pellis, Neal R. (Inventor)

    2011-01-01

    The present disclosure provides ex vivo-derived mineralized three-dimensional bone constructs. The bone constructs are obtained by culturing osteoblasts and osteoclast precursors under randomized gravity vector conditions. Preferably, the randomized gravity vector conditions are obtained using a low shear stress rotating bioreactor, such as a High Aspect Ratio Vessel (HARV) culture system. The bone constructs of the disclosure have utility in physiological studies of bone formation and bone function, in drug discovery, and in orthopedics.

  10. Mineralized Three-Dimensional Bone Constructs

    NASA Technical Reports Server (NTRS)

    Clarke, Mark S. F. (Inventor); Sundaresan, Alamelu (Inventor); Pellis, Neal R. (Inventor)

    2013-01-01

    The present disclosure provides ex vivo-derived mineralized three-dimensional bone constructs. The bone constructs are obtained by culturing osteoblasts and osteoclast precursors under randomized gravity vector conditions. Preferably, the randomized gravity vector conditions are obtained using a low shear stress rotating bioreactor, such as a High Aspect Ratio Vessel (HARV) culture system. The bone constructs of the disclosure have utility in physiological studies of bone formation and bone function, in drug discovery, and in orthopedics.

  11. The first three-dimensional vanadium hypophosphite.

    PubMed

    Maouel, Hind A; Alonzo, Véronique; Roisnel, Thierry; Rebbah, Houria; Le Fur, Eric

    2009-07-01

    The title synthesized hypophosphite has the formula V(H(2)PO(2))(3). Its structure is based on VO(6) octahedra and (H(2)PO(2))(-) pseudo-tetrahedra. The asymmetric unit contains two crystallographically distinct V atoms and six independent (H(2)PO(2))(-) groups. The connection of the polyhedra generates [VPO(6)H(2)](6-) chains extended along a, b and c, leading to the first three-dimensional network of an anhydrous transition metal hypophosphite. PMID:19578249

  12. High-resolution, real-time simultaneous 3D surface geometry and temperature measurement.

    PubMed

    An, Yatong; Zhang, Song

    2016-06-27

    This paper presents a method to simultaneously measure three-dimensional (3D) surface geometry and temperature in real time. Specifically, we developed 1) a holistic approach to calibrate both a structured light system and a thermal camera under exactly the same world coordinate system even though these two sensors do not share the same wavelength; and 2) a computational framework to determine the sub-pixel corresponding temperature for each 3D point as well as discard those occluded points. Since the thermal 2D imaging and 3D visible imaging systems do not share the same spectrum of light, they can perform sensing simultaneously in real time: we developed a hardware system that can achieve real-time 3D geometry and temperature measurement at 26 Hz with 768 × 960 points per frame. PMID:27410608

  13. Real-time aerodynamic heating and surface temperature calculations for hypersonic flight simulation

    NASA Technical Reports Server (NTRS)

    Quinn, Robert D.; Gong, Leslie

    1990-01-01

    A real-time heating algorithm was derived and installed on the Ames Research Center Dryden Flight Research Facility real-time flight simulator. This program can calculate two- and three-dimensional stagnation point surface heating rates and surface temperatures. The two-dimensional calculations can be made with or without leading-edge sweep. In addition, upper and lower surface heating rates and surface temperatures for flat plates, wedges, and cones can be calculated. Laminar or turbulent heating can be calculated, with boundary-layer transition made a function of free-stream Reynolds number and free-stream Mach number. Real-time heating rates and surface temperatures calculated for a generic hypersonic vehicle are presented and compared with more exact values computed by a batch aeroheating program. As these comparisons show, the heating algorithm used on the flight simulator calculates surface heating rates and temperatures well within the accuracy required to evaluate flight profiles for acceptable heating trajectories.

  14. FPGA-based real-time anisotropic diffusion filtering of 3D ultrasound images

    NASA Astrophysics Data System (ADS)

    Castro-Pareja, Carlos R.; Dandekar, Omkar S.; Shekhar, Raj

    2005-02-01

    Three-dimensional ultrasonic imaging, especially the emerging real-time version of it, is particularly valuable in medical applications such as echocardiography, obstetrics and surgical navigation. A known problem with ultrasound images is their high level of speckle noise. Anisotropic diffusion filtering has been shown to be effective in enhancing the visual quality of 3D ultrasound images and as preprocessing prior to advanced image processing. However, due to its arithmetic complexity and the sheer size of 3D ultrasound images, it is not possible to perform online, real-time anisotropic diffusion filtering using standard software implementations. We present an FPGA-based architecture that allows performing anisotropic diffusion filtering of 3D images at acquisition rates, thus enabling the use of this filtering technique in real-time applications, such as visualization, registration and volume rendering.

  15. Advanced Visualization of Experimental Data in Real Time Using LiveView3D

    NASA Technical Reports Server (NTRS)

    Schwartz, Richard J.; Fleming, Gary A.

    2006-01-01

    LiveView3D is a software application that imports and displays a variety of wind tunnel derived data in an interactive virtual environment in real time. LiveView3D combines the use of streaming video fed into a three-dimensional virtual representation of the test configuration with networked communications to the test facility Data Acquisition System (DAS). This unified approach to real time data visualization provides a unique opportunity to comprehend very large sets of diverse forms of data in a real time situation, as well as in post-test analysis. This paper describes how LiveView3D has been implemented to visualize diverse forms of aerodynamic data gathered during wind tunnel experiments, most notably at the NASA Langley Research Center Unitary Plan Wind Tunnel (UPWT). Planned future developments of the LiveView3D system are also addressed.

  16. Improved process control through real-time measurement of mineral content

    SciTech Connect

    Turler, Daniel; Karaca, Murat; Davis, William B.; Giauque, Robert D.; Hopkins, Deborah

    2001-11-02

    In a highly collaborative research and development project with mining and university partners, sensors and data-analysis tools are being developed for rock-mass characterization and real-time measurement of mineral content. Determining mineralogy prior to mucking in an open-pit mine is important for routing the material to the appropriate processing stream. A possible alternative to lab assay of dust and cuttings obtained from drill holes is continuous on-line sampling and real-time x-ray fluorescence (XRF) spectroscopy. Results presented demonstrate that statistical analyses combined with XRF data can be employed to identify minerals and, possibly, different rock types. The objective is to create a detailed three-dimensional mineralogical map in real time that would improve downstream process efficiency.

  17. Multiparallel Three-Dimensional Optical Microscopy

    NASA Technical Reports Server (NTRS)

    Nguyen, Lam K.; Price, Jeffrey H.; Kellner, Albert L.; Bravo-Zanoquera, Miguel

    2010-01-01

    Multiparallel three-dimensional optical microscopy is a method of forming an approximate three-dimensional image of a microscope sample as a collection of images from different depths through the sample. The imaging apparatus includes a single microscope plus an assembly of beam splitters and mirrors that divide the output of the microscope into multiple channels. An imaging array of photodetectors in each channel is located at a different distance along the optical path from the microscope, corresponding to a focal plane at a different depth within the sample. The optical path leading to each photodetector array also includes lenses to compensate for the variation of magnification with distance so that the images ultimately formed on all the photodetector arrays are of the same magnification. The use of optical components common to multiple channels in a simple geometry makes it possible to obtain high light-transmission efficiency with an optically and mechanically simple assembly. In addition, because images can be read out simultaneously from all the photodetector arrays, the apparatus can support three-dimensional imaging at a high scanning rate.

  18. Teaching and Assessing Three-Dimensional M

    NASA Astrophysics Data System (ADS)

    Bateman, Robert C., Jr.; Booth, Deborah; Sirochman, Rudy; Richardson, Jane; Richardson, David

    2002-05-01

    Structural concepts such as the exact arrangement of a protein in three dimensions are crucial to almost every aspect of biology and chemistry, yet most of us have not been educated in three-dimensional literacy and all of us need a great deal of help in order to perceive and to communicate structural information successfully. It is in the undergraduate biochemistry course where students learn most concepts of molecular structure pertinent to living systems. We are addressing the issue of three-dimensional structural literacy by having undergraduate students construct kinemages, which are plain text scripts derived from Protein Data Bank coordinate files that can be viewed with the program MAGE. These annotated, interactive, three-dimensional illustrations are designed to develop a molecular story and allow exploration in the world of that story. In the process, students become familiar with the structure-based scientific literature and the Protein Data Bank. Our assessment to date has shown that students perceive kinemage authorship to be more helpful in understanding protein structure than simply viewing prepared kinemages. In addition, students perceived kinemage authorship as being beneficial to their career and a significant motivation to learn biochemistry.

  19. Three-dimensional deformation of orthodontic brackets

    PubMed Central

    Melenka, Garrett W; Nobes, David S; Major, Paul W

    2013-01-01

    Braces are used by orthodontists to correct the misalignment of teeth in the mouth. Archwire rotation is a particular procedure used to correct tooth inclination. Wire rotation can result in deformation to the orthodontic brackets, and an orthodontic torque simulator has been designed to examine this wire–bracket interaction. An optical technique has been employed to measure the deformation due to size and geometric constraints of the orthodontic brackets. Images of orthodontic brackets are collected using a stereo microscope and two charge-coupled device cameras, and deformation of orthodontic brackets is measured using a three-dimensional digital image correlation technique. The three-dimensional deformation of orthodontic brackets will be evaluated. The repeatability of the three-dimensional digital image correlation measurement method was evaluated by performing 30 archwire rotation tests using the same bracket and archwire. Finally, five Damon 3MX and five In-Ovation R self-ligating brackets will be compared using this technique to demonstrate the effect of archwire rotation on bracket design. PMID:23762201

  20. Three-dimensional printing of the retina

    PubMed Central

    Lorber, Barbara; Hsiao, Wen-Kai; Martin, Keith R.

    2016-01-01

    Purpose of review Biological three-dimensional printing has received a lot of media attention over recent years with advances made in printing cellular structures, including skin and heart tissue for transplantation. Although limitations exist in creating functioning organs with this method, the hope has been raised that creating a functional retina to cure blindness is within reach. The present review provides an update on the advances made toward this goal. Recent findings It has recently been shown that two types of retinal cells, retinal ganglion cells and glial cells, can be successfully printed using a piezoelectric inkjet printer. Importantly, the cells remained viable and did not change certain phenotypic features as a result of the printing process. In addition, recent advances in the creation of complex and viable three-dimensional cellular structures have been made. Summary Some first promising steps toward the creation of a functional retina have been taken. It now needs to be investigated whether recent findings can be extended to other cells of the retina, including those derived from human tissue, and if a complex and viable retinal structure can be created through three-dimensional printing. PMID:27045545