Sample records for cloud motion vector

  1. MISR Level 3 Cloud Motion Vector

    Atmospheric Science Data Center

    2013-07-10

    MISR Level 3 Cloud Motion Vector Level 3 Wednesday, November 7, 2012 ... A new version, F02_0002, of the MISR L3 CMV (Cloud Motion Vector) data product is now available. This new release provides finer ... These enhancements are the result of reorganizing motion vector information present in the recent Level 2 Cloud product as opposed to ...

  2. MISR Level 3 Cloud Motion Vector Versioning

    Atmospheric Science Data Center

    2013-04-01

    ... MI3QCMVN, MI3YCMVN MISR_AM1_CMV Stage 1 Validated:  All parameters MISR maturity level ... Stereo product. Finer resolution (17.6 km versus 70.4 km) vectors and increased coverage are the primary benefits. To accomodate ...

  3. Cloud Motion Vectors from MISR using Sub-pixel Enhancements

    NASA Technical Reports Server (NTRS)

    Davies, Roger; Horvath, Akos; Moroney, Catherine; Zhang, Banglin; Zhu, Yanqiu

    2007-01-01

    The operational retrieval of height-resolved cloud motion vectors by the Multiangle Imaging SpectroRadiometer on the Terra satellite has been significantly improved by using sub-pixel approaches to co-registration and disparity assessment, and by imposing stronger quality control based on the agreement between independent forward and aft triplet retrievals. Analysis of the fore-aft differences indicates that CMVs pass the basic operational quality control 67% of the time, with rms differences - in speed of 2.4 m/s, in direction of 17 deg, and in height assignment of 290 m. The use of enhanced quality control thresholds reduces these rms values to 1.5 m/s, 17 deg and 165 m, respectively, at the cost of reduced coverage to 45%. Use of the enhanced thresholds also eliminates a tendency for the rms differences to increase with height. Comparison of CMVs from an earlier operational version that had slightly weaker quality control, with 6-hour forecast winds from the Global Modeling and Assimilation Office yielded very low bias values and an rms vector difference that ranged from 5 m/s for low clouds to 10 m/s for high clouds.

  4. A novel approach for the extraction of cloud motion vectors using airglow imager measurements

    NASA Astrophysics Data System (ADS)

    Satheesh Kumar, S.; Narayana Rao, T.; Taori, A.

    2015-03-01

    The paper explores the possibility of implementing an advanced photogrammetric technique, generally employed for satellite measurements, on airglow imager, a ground-based remote sensing instrument primarily used for upper atmospheric studies, measurements of clouds for the extraction of cloud motion vectors (CMVs). The major steps involved in the algorithm remain the same, including image processing for better visualization of target elements and noise removal, identification of target cloud, setting a proper search window for target cloud tracking, estimation of cloud height, and employing 2-D cross-correlation to estimate the CMVs. Nevertheless, the implementation strategy at each step differs from that of satellite, mainly to suit airglow imager measurements. For instance, climatology of horizontal winds at the measured site has been used to fix the search window for target cloud tracking. The cloud height is estimated very accurately, as required by the algorithm, using simultaneous collocated Lidar measurements. High-resolution, both in space and time (4 min), cloud imageries are employed to minimize the errors in retrieved CMVs. The derived winds are evaluated against MST radar-derived winds by considering it as a reference. A very good correspondence is seen between these two wind measurements, both showing similar wind variation. The agreement is also found to be good in the both zonal and meridional wind velocities with RMSEs < 2.4 m s-1. At the end, the strengths and limitations of the algorithm are discussed, with possible solutions, wherever required.

  5. An improved algorithm for extracting atmospheric motion vectors in cloud-free region from FY-2E thermal infrared imagery

    NASA Astrophysics Data System (ADS)

    Wang, Zhenhui; Zhang, Qing; Tang, Min; Zhao, Hang; Yang, Lu; Zhan, Yizhe

    2014-10-01

    Atmospheric motion vectors (AMV) in cloud-free region can not be obtained with current operational cloud-motion tracking and water-vapor channel algorithms. The motivation of this study is to introduce a supplementary algorithm in order to work out the low-level AMVs in the clear area with FY-2E long wave, window (10.3~11.5, 11.6~12.8 ?m) channel imagery. It has been shown that the weak signals indicating water vapor in "cloud-free region" can be extracted from FY-2E long wave infrared imagery and may be used as tracers for atmospheric motion vectors. The algorithm, named as Second Order difference method, has been raised in order to weaken the surface temperature interference to the weak signals of water vapor in "cloud-free region" by means of split window and temporal difference calculations. The results from theory analysis and cases study show that this method can make up for the wind data in regions lack of cloud but rich of water vapor and comparison between the wind vectors from this method and the NCEP reanalysis data shows a good consistency.

  6. Recent Progress on the Second Generation CMORPH: LEO-IR Based Precipitation Estimates and Cloud Motion Vector

    NASA Astrophysics Data System (ADS)

    Xie, Pingping; Joyce, Robert; Wu, Shaorong

    2015-04-01

    As reported at the EGU General Assembly of 2014, a prototype system was developed for the second generation CMORPH to produce global analyses of 30-min precipitation on a 0.05olat/lon grid over the entire globe from pole to pole through integration of information from satellite observations as well as numerical model simulations. The second generation CMORPH is built upon the Kalman Filter based CMORPH algorithm of Joyce and Xie (2011). Inputs to the system include rainfall and snowfall rate retrievals from passive microwave (PMW) measurements aboard all available low earth orbit (LEO) satellites, precipitation estimates derived from infrared (IR) observations of geostationary (GEO) as well as LEO platforms, and precipitation simulations from numerical global models. Key to the success of the 2nd generation CMORPH, among a couple of other elements, are the development of a LEO-IR based precipitation estimation to fill in the polar gaps and objectively analyzed cloud motion vectors to capture the cloud movements of various spatial scales over the entire globe. In this presentation, we report our recent work on the refinement for these two important algorithm components. The prototype algorithm for the LEO IR precipitation estimation is refined to achieve improved quantitative accuracy and consistency with PMW retrievals. AVHRR IR TBB data from all LEO satellites are first remapped to a 0.05olat/lon grid over the entire globe and in a 30-min interval. Temporally and spatially co-located data pairs of the LEO TBB and inter-calibrated combined satellite PMW retrievals (MWCOMB) are then collected to construct tables. Precipitation at a grid box is derived from the TBB through matching the PDF tables for the TBB and the MWCOMB. This procedure is implemented for different season, latitude band and underlying surface types to account for the variations in the cloud - precipitation relationship. At the meantime, a sub-system is developed to construct analyzed fields of cloud motion vectors from the GEO/LEO IR based precipitation estimates and the CFS Reanalysis (CFSR) precipitation fields. Motion vectors are first derived separately from the satellite IR based precipitation estimates and the CFSR precipitation fields. These individually derived motion vectors are then combined through a 2D-VAR technique to form an analyzed field of cloud motion vectors over the entire globe. Error function is experimented to best reflect the performance of the satellite IR based estimates and the CFSR in capturing the movements of precipitating cloud systems over different regions and for different seasons. Quantitative experiments are conducted to optimize the LEO IR based precipitation estimation technique and the 2D-VAR based motion vector analysis system. Detailed results will be reported at the EGU.

  7. The Effect of the Arbitrary Level Assignment of Satellite Cloud Motion Wind Vectors on Wind Analyses in the Pre-thunderstorm Environment

    Microsoft Academic Search

    Cynthia A. Peslen; Steven E. Koch; Louis W. Uccellini

    1986-01-01

    The impact of satellite-derived cloud motion vectors (CMVs) on analysts of winds measured by rawinsondes during the 1979 SESAME Experiment is studied in two case studies (10 April and 9 May 1979). Cloud motion vectors are both arbitrarily assigned and vertically interpolated to typical `low' levels of 825 mb and = 0.9 before being combined with the rawinsonde-measured winds at

  8. Atmospheric Motions from Sodium Cloud Drifts

    Microsoft Academic Search

    Adam Kochanski

    1964-01-01

    Horizontal motions from 25 sodium cloud experiments are examined in the alti- tude range from 70 to 190 km. The outstanding characteristics of the apparent motion are pro- nounced velocity oscillations in the 70- to 130-km layer; they reach a maximum near 105 km and attenuate at greater heights. A quiescent zone appears from 140 to 190 km, where, despite

  9. Constrained motion control using vector potential fields

    Microsoft Academic Search

    Samer A. Masoud; Ahmad A. Masoud

    2000-01-01

    This paper discusses the generation of a control signalthat would instruct the actuators of a robotics manipulator to drivemotion along a safe and well-behaved path to a desired target. Theproposed concept of navigation control along with the tools necessaryfor its construction achieve this goal. The most significant toolis the artificial vector potential field which shows a better ability tosteer motion

  10. Particles in Motion; Kepler's Laws 14.1. Vector Functions

    E-print Network

    McKay, Benjamin

    CHAPTER 14 Particles in Motion; Kepler's Laws 14.1. Vector Functions Vector notation is well-axis; that is X¡ 0¢£ RI. At 205 #12;Chapter 14 Particles in Motion; Kepler's Laws 206 time t the particle has

  11. Image segmentation via motion vector estimates

    NASA Astrophysics Data System (ADS)

    Abdel-Malek, Aiman A.; Hasekioglu, Orkun; Bloomer, John J.

    1990-07-01

    In the visual world moving edges in the periphery represent vital pieces of information that directs the human foveation mechanism to selectively gather information around these specific locations. This computationally efficient approach of allocating resources at key locations has inspired computer visionists to develop new target detection and hacking algorithms based on motion detection in image sequences. In this study we implemented a recursive algorithm for estimating motion vector fields for each pixel in a sequence of Digital Subtraction Angiography (DSA) images. Velocity information is used to segment the image and perform linear quadratic and acceleration-based frame interpolation to produce an apparent frame rate increase. Our results demonstrate the feasibility of low-rate digital fluoroscopy hence less exposure risks while preserving image quality. Furthermore the technique can be useful in the medical Picture Archival and Communication Systems (PACS) where image data can be compressed by storing and transmiting only the motion fields associated with the moving pixels. 1.

  12. Motion/imagery secure cloud enterprise architecture analysis

    NASA Astrophysics Data System (ADS)

    DeLay, John L.

    2012-06-01

    Cloud computing with storage virtualization and new service-oriented architectures brings a new perspective to the aspect of a distributed motion imagery and persistent surveillance enterprise. Our existing research is focused mainly on content management, distributed analytics, WAN distributed cloud networking performance issues of cloud based technologies. The potential of leveraging cloud based technologies for hosting motion imagery, imagery and analytics workflows for DOD and security applications is relatively unexplored. This paper will examine technologies for managing, storing, processing and disseminating motion imagery and imagery within a distributed network environment. Finally, we propose areas for future research in the area of distributed cloud content management enterprises.

  13. Pixel-based motion vector concatenation for Reference Picture Selection

    Microsoft Academic Search

    Hadi Hadizadeh; Ivan V. Bajic

    2010-01-01

    Reference Picture Selection (RPS) is a powerful error control technique for video streaming. Previously, two fast block-based motion vector concatenation (MVC) algorithms were proposed for video transcoding based on forward dominant vector selection (FDVS) and activity dominant vector selection (ADVS). In this paper, we examine the use of these algorithms in RPS, in the context of video transmission. We also

  14. Structure and Nonrigid Motion Analysis of Satellite Cloud Images

    Microsoft Academic Search

    Lin Zhou; Chandra Kambhamettu

    1998-01-01

    This paper proposes a new method for recoveringnonrigid motion and structure of clouds under affineconstraints using time-varying cloud images obtainedfrom meteorological satellites. This problem is challengingnot only due to the correspondence problembut also due to the lack of depth cues in the 2D cloudimages (scaled orthographic projection). In this paper,affine motion is chosen as a suitable model forsmall local cloud

  15. Motion Vector Forecast and Mapping (MV-FMap) Method for Entropy Coding based Video Coders

    E-print Network

    Paris-Sud XI, Université de

    Motion Vector Forecast and Mapping (MV-FMap) Method for Entropy Coding based Video Coders Julien Le proposes a method for motion vector coding based on an adaptive redistribution of motion vector residuals before entropy coding. Motion information is gathered to forecast a list of motion vector residuals which

  16. ALGORITHM AND SOFTWARE DEVELOPMENT OF ATMOSPHERIC MOTION VECTOR (AMV) PRODUCTS FOR THE FUTURE GOES-R ADVANCED BASELINE IMAGER (ABI)

    Microsoft Academic Search

    Jaime Daniels; Chris Velden; Wayne Bresky; Iliana Genkova; Steve Wanzong

    Atmospheric motion vectors (AMVs), derived from the current GOES series of satellites, provide invaluable tropospheric wind information to the meteorological community. AMVs obtained from tracking features (i.e., clouds and moisture gradients) are used for: i) Improving numerical weather prediction (NWP) analyses and forecasts; ii) Supporting short term forecasting activities at National Weather Service (NWS) field offices; and iii) Generating tropical

  17. Release-Rebound Processes: Vector Motions

    NASA Astrophysics Data System (ADS)

    Teisseyre, Roman

    2015-04-01

    The tensor relations describing the shear deviatoric strains and rotation strains may be presented as vector relations in a special coordinate system, e.g., in the diagonal or off-diagonal one. However, these fields can be also presented in the 4D invariant forms by means of invariant Dirac tensors. We present 4D relativistic relations for the invariant shear deviatoric strain and rotation strain vectors closely related to a fracture process in solids and to the molecular strains (shear and rotational) in fluids. These shear and rotation strains may interact with the radial derivatives of pressure along the propagation directions.

  18. Clouds on Neptune: Motions, Evolution, and Structure

    NASA Technical Reports Server (NTRS)

    Sromovsky, Larry A.; Morgan, Thomas (Technical Monitor)

    2001-01-01

    The aims of our original proposal were these: (1) improving measurements of Neptune's circulation, (2) understanding the spatial distribution of cloud features, (3) discovery of new cloud features and understanding their evolutionary process, (4) understanding the vertical structure of zonal cloud patterns, (5) defining the structure of discrete cloud features, and (6) defining the near IR albedo and light curve of Triton. Towards these aims we proposed analysis of existing 1996 groundbased NSFCAM/IRTF observations and nearly simultaneous WFPC2 observations from the Hubble Space Telescope. We also proposed to acquire new observations from both HST and the IRTF.

  19. IMPACT OF ATMOSPHERIC MOTION VECTORS ON GLOBAL NUMERICAL WEATHER PREDICTION

    Microsoft Academic Search

    Jean-Noël Thépaut; Niels Bormann; Claire Delsol; Graeme Kelly

    The importance of satellite data at large is now such that they provide the main sources of information for numerical weather prediction (NWP) models. However, the role played by Atmospheric Motion Vectors (AMVs), evaluated via a series of Observing System Experiments (OSEs), remains essential in the Global Observing System (GOS). It is in particular shown that geostationary AMVs contribute to

  20. Fast motion vector estimation using multiresolution-spatio-temporal correlations

    Microsoft Academic Search

    Junavit Chalidabhongse; C. Jay Kuo

    1997-01-01

    We propose a new fast algorithm for block motion vector (MV) estimation based on the correlations of the MVs existing in spatially and temporally adjacent as well as hierarchically related blocks. We first establish a basic framework by introducing new algorithms based on spatial correlation and then spatio-temporal correlations before integrating them with a multiresolution scheme for the ultimate algorithm.

  1. The Motion of Uneven Structure of Convective Clouds.

    NASA Astrophysics Data System (ADS)

    Takaya, Yoshimasa

    1993-02-01

    An observational study on the motion of the uneven structure on the surface of convective clouds is carried out using a lime-lapse video recorder.The development of the uneven structure shows that the mixing near the cloud-environmental interface occurs through outward motion of the projected part (turret) and inward motion of the depressed part, which are quite different from the winding billowlike motion.The theory presented here predicts the growth direction of the turret in its growing stage. Namely, two angles, one between a vertical line and the growing direction of the turret (=) and the other between the normal to the mean cloud surface at the place of the turret and the growing direction of the turret (=), are equal ( = ).Nine turrets are selected from three cumuli to compare the observation with the prediction, and a reasonable result was obtained. Average values of 2/( + ) and 2/( + ) over the nine samples are 1.11 and 0.89, respectively, with the standard deviation 0.26.

  2. Digital video steganalysis using motion vector recovery-based features.

    PubMed

    Deng, Yu; Wu, Yunjie; Zhou, Linna

    2012-07-10

    As a novel digital video steganography, the motion vector (MV)-based steganographic algorithm leverages the MVs as the information carriers to hide the secret messages. The existing steganalyzers based on the statistical characteristics of the spatial/frequency coefficients of the video frames cannot attack the MV-based steganography. In order to detect the presence of information hidden in the MVs of video streams, we design a novel MV recovery algorithm and propose the calibration distance histogram-based statistical features for steganalysis. The support vector machine (SVM) is trained with the proposed features and used as the steganalyzer. Experimental results demonstrate that the proposed steganalyzer can effectively detect the presence of hidden messages and outperform others by the significant improvements in detection accuracy even with low embedding rates. PMID:22781241

  3. Offense-defense semantic analysis of basketball game based on motion vector

    Microsoft Academic Search

    Han Xiuli; Wu Lifang; Liu Xingsheng; Cheng Zhaohui; Gong Yu

    2009-01-01

    Motions of a camera can reflect certain kinds of semantic information in video sequences; therefore, in this paper, according to the distant court shot in basketball game, we calculate the motion vector first, then analyze the semantic information of the motion vector, and finally annotate the offense-defense actions in games. Experiments are showing the possibility that the proposed technique can

  4. Cloud tracking by scale space classification

    Microsoft Academic Search

    Dipti Prasad Mukherjee; Scott T. Acton

    2002-01-01

    The problem of cloud tracking within a sequence of geo-stationary satellite images has direct relevance to the analysis of cloud life cycles and to the detection of cloud motion vectors (CMVs). The proposed approach first identifies a homogeneous consistent cloud mass for tracking and then establishes motion correspondence within an image sequence. In contrast to the crosscorrelation based approach as

  5. Semi-fixed-length motion vector coding for H.263-based low bit rate video compression.

    PubMed

    Côté, G; Gallant, M; Kossentini, F

    1999-01-01

    We present a semi-fixed-length motion vector coding method for H.263-based low bit rate video compression. The method exploits structural constraints within the motion field. The motion vectors are encoded using semi-fixed-length codes, yielding essentially the same levels of rate-distortion performance and subjective quality achieved by H.263's Huffman-based variable length codes in a noiseless environment. However, such codes provide substantially higher error resilience in a noisy environment. PMID:18267417

  6. Context-based motion retrieval using vector space model

    E-print Network

    Zhang, Zhunping

    2008-01-01

    Motion retrieval is the problem of retrieving highly relevant motions in a timely manner. The principal challenge is to characterize the similarity between two motions effectively, which is tightly related to the gap between ...

  7. Efficient motion estimation using edge-based binary block-matching and refinement based on motion vector correlation

    Microsoft Academic Search

    Jae Hun Lee; Jong Beom Ra

    2001-01-01

    A fast block-matching motion estimation algorithm is proposed for efficient hardware implementation in video coding standards. The proposed algorithm consists of the binary block-matching (BBM) step based on edge information, the first refinement step around the motion vector (MV) obtained from BBM, and the second but conditional refinement step using spatial correlation of neighboring MVs. The proposed algorithm gives the

  8. Autonomous mobile robot global motion planning and geometric beacon collection using traversability vectors

    Microsoft Academic Search

    J. A. Janet; R. C. Luo; M. G. Kay

    1997-01-01

    Approaches in global motion planning (GMP) and geometric beacon collection (for self-localization) using traversability vectors have been developed and implemented in both computer simulation and actual experiments on mobile robots. Both approaches are based on the same simple, modular, and multifunctional traversability vector (t-vector). Through implementation it has been found that t-vectors reduce the computational requirements to detect path obstructions,

  9. Clouds

    NSDL National Science Digital Library

    First, the Project Atmosphere Canada offers a module to educate primary and secondary students about cloud formation and characteristics (1). The website outlines key points and offers a more in-depth discussion of water vapor, cloud formation, convection, air motion, severe weather, and more. The second website, by Scholastic, supplies many pdf documents of activities and lesson plans for all types of weather phenomena including clouds (2). Students can learn about condensation, discover what makes up a cloud, and find a key identifying the cloud types. Next, USA Today offers an online tutorial of the differing characteristics of clouds (3). Users can learn about Mammatus clouds, contrails, cloud seeding, and other cloud-related topics. At the fourth website, visitors can view meteorologist Dan Satterfield's amazing cloud photographs (4). Educators may find useful materials to supplement their lectures. Next, NASA's Climate and Radiation Branch furnishes "information on the fantastic variety of cloud forms and structures, and their implications for climate" (5). While the website is still being constructed, users can find useful information about the Bounded Cascades Fractal Cloud model, animations, and definitions of inhomogeneous cloud terminology. The sixth website, created by the National Center for Atmospheric Research and the University Corporation for Atmospheric Research, addresses how clouds impact our lives, how they cause chaos, and how they form (6). The enlightening descriptions are packed with colorful images and short quizzes. Next, The Australian Government's Bureau of Meteorology describes the useful of clouds as an indicator of weather conditions (7). After learning how moist air can form clouds, individuals can view images of the ten most common cloud types. Lastly, Enchanted Learning offers a table of the cloud types with their abbreviation, appearance, composition, and altitude along with explanations of cloud formation and the atmosphere (8). Educators can find simple activities dealing with cloud types and the water cycle.

  10. Landsat 7 Reveals Large-scale Fractal Motion of Clouds

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This Landsat 7 image of clouds off the Chilean coast near the Juan Fernandez Islands (also known as the Robinson Crusoe Islands) on September 15, 1999, shows a unique pattern called a 'von Karman vortex street.' This pattern has long been studied in the laboratory, where the vortices are created by oil flowing past a cylindrical obstacle, making a string of vortices only several tens of centimeters long. Study of this classic 'flow past a circular cylinder' has been very important in the understanding of laminar and turbulent fluid flow that controls a wide variety of phenomena, from the lift under an aircraft wing to Earth's weather. Here, the cylinder is replaced by Alejandro Selkirk Island (named after the true 'Robinson Crusoe,' who was stranded here for many months in the early 1700s). The island is about 1.5 km in diameter, and rises 1.6 km into a layer of marine stratocumulus clouds. This type of cloud is important for its strong cooling of the Earth's surface, partially counteracting the Greenhouse warming. An extended, steady equatorward wind creates vortices with clockwise flow off the eastern edge and counterclockwise flow off the western edge of the island. The vortices grow as they advect hundreds of kilometers downwind, making a street 10,000 times longer than those made in the laboratory. Observing the same phenomenon extended over such a wide range of sizes dramatizes the 'fractal' nature of atmospheric convection and clouds. Fractals are characteristic of fluid flow and other dynamic systems that exhibit 'chaotic' motions. Both clockwise and counter-clockwise vortices are generated by flow around the island. As the flow separates from the island's leeward (away from the source of the wind) side, the vortices 'swallow' some of the clear air over the island. (Much of the island air is cloudless due to a local 'land breeze' circulation set up by the larger heat capacity of the waters surrounding the island.) The 'swallowed' gulps of clear island air get carried along within the vortices, but these are soon mixed into the surrounding clouds. Landsat is unique in its ability to image both the small-scale eddies that mix clear and cloudy air, down to the 30 meter pixel size of Landsat, but also having a wide enough field-of-view, 180 km, to reveal the connection of the turbulence to large-scale flows such as the subtropical oceanic gyres. Landsat 7, with its new onboard digital recorder, has extended this capability away from the few Landsat ground stations to remote areas such as Alejandro Island, and thus is gradually providing a global dynamic picture of evolving human-scale phenomena. (For more details on von Karman vortices, refer to http://climate.gsfc.nasa.gov/cahalan) Image and caption courtesy Bob Cahalan, NASA GSFC

  11. Vector constants of motion for time-dependent Kepler and isotropic harmonic oscillator potentials

    E-print Network

    O. M. Ritter; F. C. Santos; A. C. Tort

    2000-03-29

    A method of obtaining vector constants of motion for time-independent as well as time-dependent central fields is discussed. Some well-established results are rederived in this alternative way and new ones obtained.

  12. Vertical motion diagnostics related to Q-vectors, and the reorganisation of a cold frontal system

    Microsoft Academic Search

    R. G. Tapp

    1988-01-01

    Summary Estimates of vertical motion obtained by explicit solution of the quasi-geostrophic omega equation expressed in terms of Q-vectors (Hoskins et al., 1978) were compared with qualitative estimates based on the divergence of Q-vectors. The horizontal distributions of each were broadly similar, but differed in their detail. At any level, the relative magnitudes of centres of vertical motion varied between

  13. Using Haptic Vector Fields for Animation Motion Control Technical Report PCS-TR99-353

    E-print Network

    Using Haptic Vector Fields for Animation Motion Control Technical Report PCS-TR99-353 Bruce Randall, 1999 Abstract We are exploring techniques for animation authoring and editing using a haptic force defines a time-varying, higher-order vector field on a configura- tion space for the animation. A haptic

  14. Effect of GOES-R Image Navigation and Registration Errors on Atmospheric Motion Vectors

    NASA Technical Reports Server (NTRS)

    Jedlovec, Gary

    2008-01-01

    High temporal frequency imagery from geostationary satellites allows for the continuous monitoring of rapidly changing atmospheric constituents such as smoke, dust, water vapor and clouds. The image sequences are often used to quantify the displacement of image features such as water vapor and clouds to produce atmospheric motion vectors (AMVs) which are used as diagnostic tools and also assimilated into numerical weather forecast models. The basic principle behind the determination of AMVs is the calculation of the physical displacement of features from one image (time) to the next. This process assumes that the features being tracked do not change as a function of time, usually requiring the use of short time interval imagery to minimize substantial change in size and shape of the features being tracked. High spatial resolution imagery also is required for reliable feature identification. While these image resolution and temporal sampling requirements often provide major drivers for space-based instrument design requirements, accurate image navigation and registration, INn (between a sequence of images), is also critical to the derivation of useful AMVs. In this paper and poster to be presented at the conference, the image navigation and registration (INR) accuracy expected for the Advanced Baseline Imager (ABI) on the GOES-R series of satellites will be discussed in light of its impact on AMV accuracy. Significant satellite platform and modeling enhancements are planned which should significantly improve INn performance of the GOES-R instruments. Some of these improvements have been demonstrated for the GOES-13 satellite which was launched in summer of 2006. An analysis of GOES-13 INR data, from the special satellite check out period, will be used in the assessment.

  15. T-vectors make autonomous mobile robot motion planning and self-referencing more efficient

    Microsoft Academic Search

    J. A. Janet; Ren C. Luo; Michael G. Kay

    1994-01-01

    A motion planning and self-referencing approach has been developed, simulated and applied to an actual robot. Although there are several novelties to these approaches, the fact that both are based on traversability vectors (t-vectors) is one aspect of this research that is unique. Through their application it has been found that t-vectors enhance the detection of path obstructions and geometric

  16. Practical usefulness of structure from motion (SfM) point clouds obtained from different consumer cameras

    NASA Astrophysics Data System (ADS)

    Ingwer, Patrick; Gassen, Fabian; Püst, Stefan; Duhn, Melanie; Schälicke, Marten; Müller, Katja; Ruhm, Heiko; Rettig, Josephin; Hasche, Eberhard; Fischer, Arno; Creutzburg, Reiner

    2015-03-01

    This paper deals with the usefulness and accuracy of point clouds obtained by different consumer cameras out of Structure from motion (SfM) algorithms. It summarizes some research results of the practical usage of the SfM method in applications where highly accurate point clouds are required.

  17. Novel block matching algorithm using predictive motion vector for video object tracking based on color histogram

    Microsoft Academic Search

    N. G. Chitaliya; A. I. Trivedi

    2011-01-01

    Block matching motion estimation plays significant role for video processing and Computer Vision. Various methods based on mean shift and particle trackers are used to track the object on video sequence. Block matching algorithm is normally used for video compression technique. A novel, simple and fast block matching algorithm has been proposed using predictive motion vector for object tracking. Color

  18. ACARS wind measurements - An intercomparison with radiosonde, cloud motion and VAS thermally derived winds. [Communications, Addressing and Reporting System VISSR Atmospheric Sounder

    NASA Technical Reports Server (NTRS)

    Lord, R. J.; Menzel, W. P.; Pecht, L. E.

    1984-01-01

    Statistical comparisons between winds measured by ACARS and winds obtained from radiosondes, geostationary satellite image cloud motions, and VAS are presented. Observations from three separate comparisons reveal over 60 percent of wind vector magnitude differences are within 9 m/s, and 70 percent of the directional differences are within 15 deg. The comparisons indicate that the ACARS system provides an independent source of wind data that complements other sources of wind data for constructing composite wind field analyses.

  19. Vertical Motion Calculations and Satellite Cloud Observations over the Western and Central United States

    Microsoft Academic Search

    John Hansen; Alymer H. Thomson

    1965-01-01

    Vertical motions over the western and central United States during 19-21 August 1961 were computed by several methods. The resulting angles applicable, at 700 mb or 10,000 ft (600 mb for the Joint Numerical Weather Prediction vertical motion fields) were compared both subjectively and objectively to each other, to the corresponding standard type cloud and weather observations, and to approximately

  20. University Navstar Consortium GPS Site Motion Vector/Crustal Velocity Archive

    NSDL National Science Digital Library

    The University Navstar Consortium (UNAVCO) Boulder facility has developed a Global Positioning System (GPS) Site Motion Vector Archive. Precise motions of points on the Earth, made with continuous or episodic GPS measurements, are being used to study tectonic processes including plate motions, plate boundary zone deformation, earthquakes, and volcanic eruptions. This archive of GPS velocities contains project information, maps, links, data, and metadata from both regional and global GPS analyses and showcases the work conducted by university and other research investigators. The archive also contains a global plate motion model velocity calculator and an interactive map tool. Velocity data are also accessible via a Distributed Ocean Data Sets (DODS) server.

  1. Convective and moist vorticity vectors associated with tropical oceanic convection: A three-dimensional cloud-resolving model simulation

    NASA Astrophysics Data System (ADS)

    Gao, Shouting; Li, Xiaofan; Tao, Wei-Kuo; Shie, Chung-Lin; Lang, Steve

    2007-01-01

    The relationships between cloud hydrometeors and convective/moist vorticity vectors are investigated using hourly data from a three-dimensional, 5-day cloud-resolving model (CRM) simulation during the Tropical Rainfall Measuring Mission (TRMM) Kwajalein Experiment (KWAJEX). Vertical components of convective and moist vorticity vectors are highly correlated with cloud hydrometeors. The vertical components represent the interaction between horizontal vorticity and horizontal moist potential temperature/specific humidity gradient. The vertical components of convective and moist vorticity vectors can be used to study tropical oceanic convection in both two-dimensional and three-dimensional frameworks.

  2. Image sequence coding using quincunx wavelet transform, motion compensation, and lattice vector quantization

    NASA Astrophysics Data System (ADS)

    Gaidon, Thierry; Barlaud, Michel; Mathieu, Pierre

    1992-11-01

    This paper is concerned with image sequence coding based on motion estimation-compensation using a pel-recursive technique. Motion estimation achieved by minimization of a functional is improved by the incorporation of a discontinuity constraint on the optical flow. The prediction errors are vector quantized using lattices. Recent work enabled us to use truncated lattices (D4, E8, L16, ...) in pyramidal form to construct the codebooks. The coding results were achieved on real sequence image.

  3. Properties of Precipitation and In-Cloud Vertical Motion in a Global Nonhydrostatic Aquaplanet Experiment

    Microsoft Academic Search

    Tomoe NASUNO; Masaki Satoh

    2011-01-01

    To gain insight into properties of in-cloud vertical motion and precipitation production in the tropics, three-dimensional outputs from an aquaplanet experiment using a 3.5-km mesh global cloud-system resolving model (GCRM) were analyzed. Probability distributions of precipitation and latent heating in the 10°N–10°S domain are evaluated in comparison with Tropical Rainfall Measurement Mission (TRMM) observations. Despite biases of generally higher precipitation

  4. Compressed domain video indexing techniques using DCT and motion vector information in MPEG video \\Lambda

    E-print Network

    Lin, King-Ip "David"

    Compressed domain video indexing techniques using DCT and motion vector information in MPEG video multimedia applications hinges on the availability of fast and efficient storage, brows­ ing, indexing selection, feature extraction, and indexing and retrieval techniques that are directly applicable to MPEG

  5. On the orbital motion of cold clouds in BLRs

    E-print Network

    Shadmehri, Mohsen

    2015-01-01

    We study orbit of a pressure-confined cloud in the broad-line region (BLR) of active galactic nuclei (AGNs) when the combined effects of the central gravity and anisotropic radiation pressure and the drag force are considered. Physical properties of the intercloud gas such as its pressure and dynamic viscosity are defined as power-law functions of the radial distance. For a drag force proportional to the relative velocity of a cloud and the background gas, a detailed analysis of the orbits is performed for different values of the input parameters. We also present analytical solutions for a situation where the intercloud pressure is uniform and the viscosity is proportional to the inverse square of the radial distance. Our analytical and numerical solutions demonstrate decay of the orbits because of considering the drag force so that a cloud will eventually fall onto the central region after so called time-of-flight. We found that time-of-flight of a BLR cloud is proportional to the inverse of the dimensionles...

  6. Multiangle Remote Sensing of Optically Thin Cirrus Clouds From MISR Using Support Vector Machines

    NASA Astrophysics Data System (ADS)

    Garay, M. J.; Mazzoni, D.; Davies, R.; Wagstaff, K.

    2004-05-01

    Thin cirrus clouds, those with optical depths less than 1, can potentially have large radiative effects on the atmospheric and surface energy budgets in regions where they are prevalent. They also present an impediment to the retrieval of clear sky properties such as aerosol optical depth, temperature profiles, etc. Such clouds, however, are notoriously difficult to detect using standard satellite remote sensing techniques. The unique multiangle sensing capability of the Multiangle Imaging SpectroRadiometer (MISR) on NASA's Terra satellite, in particular the availability of cameras with view angles as large as 70.5 degrees, gives MISR the ability to detect thin cirrus clouds that are invisible to nadir-looking instruments. While MISR has been operational for over four years and many scenes containing thin cirrus have been examined on a per case basis, there remains a need to objectively and automatically identify just the cirrus clouds within any given scene. Based on our previous work applying machine learning technology to develop a more robust MISR cloud mask, we have developed a thin cirrus cloud detector for MISR, using Support Vector Machines (SVMs), and taking advantage of spectral, spatial and angular signature information from MISR's 45.6, 60 and 70.5-degree cameras. For a few representative cases, we will demonstrate the accuracy of the SVM cirrus retrieval, especially in comparison to a traditional nadir-looking retrieval, emphasizing the usefulness of the multiangle approach. We then show how this trained SVM can be used to generate a climatology of thin cirrus clouds.

  7. Numerical investigation of the motion of a growing droplet in a thermal diffusion cloud chamber

    Microsoft Academic Search

    F. Utheza; F. Garnier

    2003-01-01

    The evolution of spherical droplets resulting from the homogeneous condensation of vapor phase diluted in a background gas has been studied numerically. The model was compared with experimental data of dioctylphthalate (DOP) droplets in binary gaseous mixture of DOP-helium and of DOP-hydrogen in a thermal diffusion cloud chamber (TDCC). The motion of droplets due to thermodiffusiophoresis as obtained from numerical

  8. Fast subpel motion estimation for H.264/advanced video coding with an adaptive motion vector accuracy decision

    NASA Astrophysics Data System (ADS)

    Lee, Hoyoung; Jung, Bongsoo; Jung, Jooyoung; Jeon, Byeungwoo

    2012-11-01

    The quarter-pel motion vector accuracy supported by H.264/advanced video coding (AVC) in motion estimation (ME) and compensation (MC) provides high compression efficiency. However, it also increases the computational complexity. While various well-known fast integer-pel ME methods are already available, lack of a good, fast subpel ME method results in problems associated with relatively high computational complexity. This paper presents one way of solving the complexity problem of subpel ME by making adaptive motion vector (MV) accuracy decisions in inter-mode selection. The proposed MV accuracy decision is made using inter-mode selection of a macroblock with two decision criteria. Pixels are classified as stationary (and/or homogeneous) or nonstationary (and/or nonhomogeneous). In order to avoid unnecessary interpolation and processing, a proper subpel ME level is chosen among four different combinations, each of which has a different MV accuracy and number of subpel ME iterations based on the classification. Simulation results using an open source x264 software encoder show that without any noticeable degradation (by -0.07 dB on average), the proposed method reduces total encoding time and subpel ME time, respectively, by 51.78% and by 76.49% on average, as compared to the conventional full-pel pixel search.

  9. An Efficient Motion Vector Coding Scheme Based on Prioritized Reference Decision

    NASA Astrophysics Data System (ADS)

    Zhou, Dajiang; Zhou, Jinjia; Goto, Satoshi

    In the latest video coding frameworks, efficiency of motion vector (MV) coding is becoming increasingly important because of the growing bit rate portion of motion information. However, neither the conventional median predictor, nor the newer schemes such as the minimum bit rate prediction scheme and the hybrid scheme, can effectively eliminate the local redundancy of motion vectors. In this paper, we present the prioritized reference decision scheme for efficient motion vector coding, based on the H.264/AVC framework. This scheme makes use of a boolean indicator to specify whether the median predictor is to be used for the current MV or not. If not, the median prediction is considered not suitable for the current MV, and this information is used for refining the possible space of a group of reference MVs including 4 neighboring MVs and the zero MV. This group of MVs is organized to be a prioritized list so that the reference MV with highest priority is to be selected as the prediction value. Furthermore, the boolean indicators are coded into the modified code words of mb_type and sub_mb_type, so as to reduce the overhead. By applying the proposed scheme, the structure and the applicability problems with the state-of-the-art MBP scheme have been overcome. Experimental result shows that the proposed scheme achieves a considerable reduction of bits for MVDs, compared with the conventional median prediction algorithm. It also achieves a better and much stabler performance than MBP-based MV coding.

  10. Integrals of Motion in the Two Killing Vector Reduction of General Relativity

    E-print Network

    Nenad Manojlovi?; Bill Spence

    1993-08-20

    We apply the inverse scattering method to the midi-superspace models that are characterized by a two-parameter Abelian group of motions with two spacelike Killing vectors. We present a formulation that simplifies the construction of the soliton solutions of Belinski\\v i and Zakharov. Furthermore, it enables us to obtain the zero curvature formulation for these models. Using this, and imposing periodic boundary conditions corresponding to the Gowdy models when the spatial topology is a three torus $T ^3$, we show that the equation of motion for the monodromy matrix is an evolution equation of the Heisenberg type. Consequently, the eigenvalues of the monodromy matrix are the generating functionals for the integrals of motion. Furthermore, we utilise a suitable formulation of the transition matrix to obtain explicit expressions for the integrals of motion. This involves recursion relations which arise in solving an equation of Riccati type. In the case when the two Killing vectors are hypersurface orthogonal the integrals of motion have a particularly simple form.

  11. On the air motion in continental shallow cumulus clouds: large-eddy simulation versus radar observation

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Chandra, A.; Klein, S. A.

    2013-12-01

    Summertime observations for 13 years at Atmospheric Radiation Measurement Southern Great Plains (SGP) site are used to study air motion in non-precipitating fair-weather shallow cumulus clouds. A composite shallow cumulus case is constructed based on an ensemble of days with observed active shallow cumulus clouds. Large-scale forcing for this composite case is derived accordingly based on observation-constrained variational analysis and is used to drive the large-eddy simulation (LES), whose set-up is most suitable to make an apple-to-apple comparison with radar observation at the site. At the same time, a novel retrieval algorithm, which can remove the insects' contamination on radar reflectivity, is applied to millimeter cloud radar 10s observations to get vertical velocity of air motion in the shallow cumulus cloud ensembles. We then focus on the behavior of cloudy profiles with liquid water path greater than 80 g/m^2. This is done because we believe this portion of cloud makes a major contribution to the total mass flux and by so doing, the uncertainty is minimized in the comparison between observation and LES results. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-641597

  12. Stratiform clouds and their interaction with atmospheric motion

    NASA Technical Reports Server (NTRS)

    Clark, John H. E.; Shirer, Hampton N.

    1990-01-01

    During 1989 and 1990, the researchers saw the publication of two papers and the submission of a third for review on work supported primarily by the previous contract, NAS8-36150; the delivery of an invited talk at the SIAM Conference on Dynamical Systems in Orlando, Florida; and the start of two new projects on the radiative effects of stratocumulus on the large-scale flow. The published papers discuss aspects of stratocumulus circulations (Laufersweiler and Shirer, 1989) and the Hadley to Rossby regime transition in rotating spherical systems (Higgins and Shirer, 1990). The submitted paper (Haack and Shirer, 1990) discusses a new nonlinear model of roll circulations that are forced both dynamically and thermally. The invited paper by H. N. Shirer and R. Wells presented an objective means for determining appropriate truncation levels for low-order models of flows involving two incommensurate periods; this work has application to the Hadley to Rossby transition problem in quasi-geostrophic flows (Moroz and Holmes, 1984). The new projects involve the development of a multi-layered quasi-geostrophic channel model for study of the modulation of the large-scale flow by stratocumulus clouds that typically develop off the coasts of continents. In this model the diabatic forcing in the lowest layer will change in response to the (parameterized) development of extensive fields of stratocumulus clouds. To guide creation of this parameterization scheme, researchers are producing climatologies of stratocumulus frequency and the authors correlate these frequencies with the phasing and amplitude of the large-scale flow pattern. Researchers discuss the above topics in greater detail.

  13. Global-Vector Representation of the Angular Motion of Few-Particle Systems II

    E-print Network

    Y. Suzuki; W. Horiuchi; M. Orabi; K. Arai

    2008-04-01

    The angular motion of a few-body system is described with global vectors which depend on the positions of the particles. The previous study using a single global vector is extended to make it possible to describe both natural and unnatural parity states. Numerical examples include three- and four-nucleon systems interacting via nucleon-nucleon potentials of AV8 type and a 3$\\alpha$ system with a nonlocal $\\alpha\\alpha$ potential. The results using the explicitly correlated Gaussian basis with the global vectors are shown to be in good agreement with those of other methods. A unique role of the unnatural parity component, caused by the tensor force, is clarified in the $0^-_1$ state of $^4$He. Two-particle correlation function is calculated in the coordinate and momentum spaces to show different characteristics of the interactions employed.

  14. Proper Motion and Internal Kinematics of the SMC: are the Magellanic Clouds bound to one another?

    NASA Astrophysics Data System (ADS)

    Kallivayalil, Nitya

    2013-10-01

    We propose a long-term GO program of WFC3/UVIS imaging of 30 newly identified QSOs behind the Small Magellanic Cloud {SMC} to measure proper motions {PMs}. A campaign separated by two years will allow us to measure the rotation, internal structure, and center-of-mass motion of the SMC. Our current understanding of these issues is limited by the small number of QSOs that were available to probe the SMC's motion {only 5}. We now have a large number of well-distributed QSO fields that will enable a direct separation of the internal motions and the center-of-mass motion. We show that our SMC measurements will constrain all major outstanding questions about the dynamics and origin of the Magellanic system, within the precision of a two-year baseline program: whether the LMC and SMC are in a binary, whether they are on their first infall into the Milky Way, the implied Milky Way mass, and the rotation of the SMC. The latter will constrain whether the SMC is an example of a dwarf in transition between a gas rich, rotation-supported dwarf Irregular, and a dispersion-supported dwarf Spheroidal, and whether the LMC is responsible for this transition.

  15. A Motion-Stabilized W-Band Radar for Shipboard Observations of Marine Boundary-Layer Clouds

    NASA Astrophysics Data System (ADS)

    Moran, Ken; Pezoa, Sergio; Fairall, Chris; Williams, Chris; Ayers, Tom; Brewer, Alan; de Szoeke, Simon P.; Ghate, Virendra

    2012-04-01

    Cloud radars at X, Ka and W-bands have been used in the past for ocean studies of clouds, but the lack of suitable stabilization has limited their usefulness in obtaining accurate measurements of the velocity structure of cloud particles and the heights of cloud features. A 94 GHz (W-band) radar suitable for use on shipboard studies of clouds has been developed that is small and lightweight and can maintain the radar's beam pointing in the vertical to reduce the affects of the pitch and roll of the ship. A vertical velocity sensor on the platform allows the effects of the ship's heave to be removed from the measured cloud particle motions. Results from the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-Rex) field program on the NOAA vessel Ronald H. Brown demonstrate the improvements to the cloud measurements after the ship's motion effects are removed. The compact design of the radar also makes it suitable for use in aircraft studies. The radar is being repackaged to fit in an aft bay of a NOAA P3 aircraft to observe sea-spray profiles during ocean storms.

  16. A convective vorticity vector associated with tropical convection: A two-dimensional cloud-resolving modeling study

    NASA Astrophysics Data System (ADS)

    Gao, Shouting; Ping, Fan; Li, Xiaofan; Tao, Wei-Kuo

    2004-07-01

    Although dry/moist potential vorticity ((? · ??e)/?) is a useful physical quantity for meteorological analysis, it cannot be applied to the analysis of two-dimensional (2-D) simulations. A new vorticity vector (? × ??e)/? (convective vorticity vector (CVV)) is introduced in this study to analyze 2-D cloud-resolving simulation data associated with 2-D tropical convection. The cloud model is forced by the vertical velocity, zonal wind, horizontal advection, and sea surface temperature obtained from the Tropical Ocean-Global Atmosphere (TOGA) Coupled Ocean-Atmosphere Response Experiment (COARE) and is integrated for a selected 10-day period. The CVV has zonal and vertical components in the 2-D x-z frame. Analysis of zonally averaged and mass-integrated quantities shows that the correlation coefficient between the vertical component of the CVV and the sum of the cloud hydrometeor mixing ratios is 0.81, whereas the correlation coefficient between the zonal component and the sum of the mixing ratios is only 0.18. This indicates that the vertical component of the CVV is closely associated with tropical convection. The tendency equation for the vertical component of the CVV is derived and the zonally averaged and mass-integrated tendency budgets are analyzed. The tendency of the vertical component of the CVV is determined by the interaction between the vorticity and the zonal gradient of cloud heating. The results demonstrate that the vertical component of the CVV is a cloud-linked parameter and can be used to study tropical convection.

  17. Clouds

    NSDL National Science Digital Library

    Carl Wozniak

    Clouds comprise a wonderful focus for classroom study. They're ubiquitous, ever-changing, scientifically interesting and, most importantly for teachers, they're cheap. The material presented here includes sections on cloud formation, cloud types, cloud pictures, other cloud-related phenomena, and a glossary.

  18. Higher Dimensional Strange Quark Matter Coupled to the String Cloud with Electromagnetic Field Admitting One Parameter Group of Conformal Motion

    NASA Astrophysics Data System (ADS)

    Anirudh, Pradhan; Khadekar S., G.; Mukesh, Mishra Kumar; Saroj, Kumbhare

    2007-10-01

    We solve Einstein's field equations in higher-dimensional spherically symmetric spacetime with strange quark matter attached to the string cloud, assuming one parameter group of conformal motions. The solutions match with the higher-dimensional Reissner-Nordström metric on the boundary at r = r0. The features of the solutions are also discussed in the framework of higher-dimensional spacetime.

  19. The Motions and Morphologies of cloud features on Neptune: continued monitoring with Keck Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Martin, S. C.; de Pater, I.; Gibbard, S. G.; Macintosh, B. A.; Roe, H. G.; Max, C. E.

    2002-09-01

    We present near infrared images taken in the H band (1.4-1.8 microns) using the newly commissioned NIRC2 at the W. M. Keck II telescope as part of a continuing program to monitor the atmospheric dynamics of Neptune using Adaptive Optics. These images with a resolution of .06 arcseconds reveal five infrared bright groups of features. Two groups of features (30-40 deg N and 20-50 deg S) are confined in latitude but span all longitudes creating bands around the planet. Small cloud morphology and relative motions in the wide Southern band (20-50 deg S) identify apparent cloud shearing events and differences in relative speeds within latitude bands. One localized group of features (30 deg N) shows interesting morphologies with marked departures from lines of latitude. Another localized group of South Polar features (70 deg S) show changes in morphology from a teardrop to a train of clouds to an arc of features during three years of observations. The final group of features is spatially diffuse and spans many latitude lines but is tightly confined in longitude. This research was supported in part by the STC Program of the National Science Foundation under Agreement No. AST-9876783, and in part under the auspices of the US Department of Energy at Lawrence Livermore National Laboratory, Univ. of Calif. under contract No. W-7405-Eng-48. Data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

  20. Vectors

    NSDL National Science Digital Library

    Stern, David P. (David Peter), 1931-

    This web page, authored and curated by David P. Stern, introduces vectors as an extension of numbers having both magnitude and direction. The initial motivation is to describe velocity but the material includes a general discussion of vector algebra and an application to forces for the inclined plane. The page contains links to a related lesson plan and further opportunities to explore vectors. This is part of the extensive web site "From Stargazers to Starships", that uses space exploration and space science to introduce topics in physics and astronomy. Translations in Spanish and French are available.

  1. Compressed-domain video indexing techniques using DCT and motion vector information in MPEG video

    NASA Astrophysics Data System (ADS)

    Kobla, Vikrant; Doermann, David S.; Lin, King-Ip; Faloutsos, Christos

    1997-01-01

    Development of various multimedia applications hinges on the availability of fast and efficient storage, browsing, indexing, and retrieval techniques. Given that video is typically stored efficiently in a compressed format, if we can analyze the compressed representation directly, we can avoid the costly overhead of decompressing and operating at the pixel level. Compressed domain parsing of video has been presented in earlier work where a video clip is divided into shots, subshots, and scenes. In this paper, we describe key frame selection, feature extraction, and indexing and retrieval techniques that are directly applicable to MPEG compressed video. We develop a frame-type independent representation of the various types of frames present in an MPEG video in which al frames can be considered equivalent. Features are derived from the available DCT, macroblock, and motion vector information and mapped to a low-dimensional space where they can be accessed with standard database techniques. The spatial information is used as primary index while the temporal information is used to enhance the robustness of the system during the retrieval process. The techniques presented enable fast archiving, indexing, and retrieval of video. Our operational prototype typically takes a fraction of a second to retrieve similar video scenes from our database, with over 95% success.

  2. The Impact of Satellite Atmospheric Motion Vectors in the GMAO GEOS-5 Global Data Assimilation System

    NASA Technical Reports Server (NTRS)

    Gelaro, R. D.; Merkova, D.; Tai, King-Sheng; McCarty, W.

    2012-01-01

    The impact of satellite-derived atmospheric motion vectors (AMVs) on numerical weather forecasts is examined using the GEOS-5 global atmospheric data assimilation system. Cycling data assimilation experiments, including twice-daily 5-day forecasts, are conducted for two 6-week periods during the 2010 Atlantic hurricane season and 2010-2011Northern Hemisphere winter season. Results from a control experiment that includes all AMVs and other data types assimilated operationally in GEOS-5 are compared with those from an experiment in which the GEOS-5 AMVs (only) are replaced by ones produced by the U. S. Navy?s NAVDAS-AR atmospheric data assimilation system. The Navy AMVs are assimilated in their entirety as well as in various subset combinations. The primary objective of these experiments is to determine whether aspects of the NAVDAS-AR data selection and quality control procedure, especially the use of carefully averaged ("super-ob?) wind vectors and large volume of AMVs, explain the typically larger beneficial impact of these data in the Navy system as compared with most other forecast systems. Adjoint-based observation impact calculations are assessed and compared with traditional metrics such as forecast geopotential height anomaly correlations and observation-minus-forecast departures. Results so far indicate that that the greater number of NRL AMVs is primarily responsible for their larger impact, although superobing also appears to be beneficial. Map views show that the impact obtained from assimilation of the NRL AMVs is more uniformly beneficial, perhaps due to the averaging of individual observations in creating the super-obs. While the NRL AMVs have a much larger impact in GEOS-5 than do the control AMVs, their impact is still smaller than in the Navy forecast system, suggesting that the mix of observations may play an important role in modulating the impact of any one data type. At the same time, reducing the number of satellite radiances assimilated in GEOS-5 does not significantly alter the impact of the AMVs

  3. Clouds

    NSDL National Science Digital Library

    Ms. Doxey

    2010-03-26

    Students learn about the varieties of clouds, what they look like and how they can affect our lives. Introduction: Have you ever wondered what kind of cloud makes rain, or which one makes fog? Have you ever wondered if there are clouds that mean the weather if going to be good or not? Today, we're going to learn about three different clouds that may ...

  4. A proper motion study of the Lupus clouds using VO tools

    E-print Network

    Martí, Belén López; Solano, Enrique

    2011-01-01

    Aims: By using kinematical information, we test the membership of the new Lupus candidate members proposed by the Cores to Disks (c2d) Spitzer Legacy Program program and by a complementary optical survey. We also investigate the relationship between the proper motions (pm) and other properties, in order to get some clues about their formation and early evolution. Methods: We compiled a list of members and possible members of Lupus 1, 3, and 4, together with all information on their spectral types, disks, and physical parameters. Using VO-tools, we cross-matched this list with the astrometric catalogues to get pm. Our final sample contains sources with magnitudes I~0.1Msun. Results: According to the kinematic information, our sources can be divided into two main groups. The first one contains sources with higher pm in agreement with other Gould Belt populations and with spatial distribution, optical and near-infrared colours, and disk composition consistent with these objects belonging to the Lupus clouds. In ...

  5. Hurricane Debby - An illustration of the complementary nature of VAS soundings and cloud and water vapor motion winds. [Visible Infrared Spin Scan Radiometer Atmospheric Sounder

    NASA Technical Reports Server (NTRS)

    Le Marshall, J. F.; Smith, W. L.; Callan, G. M.

    1985-01-01

    The utility of VISSR Atmospheric Sounder (VAS) temperature and moisture soundings and cloud and water vapor motion winds in defining a storm and its surroundings at subsynoptic scales has been examined using a numerical analysis and prognosis system. It is shown that the VAS temperature and moisture data, which specify temperature and moisture well in cloud-free areas, are complemented by cloud and water vapor motion data generated in the cloudy areas. The cloud and water vapor 'winds' provide thermal gradient information for interpolating the soundings across cloudy regions. The loss of analysis integrity due to the reduction of VAS sounding density in the cloudy regions associated with synoptic activity is ameliorated by using cloud and water vapor motion winds. The improvement in numerical forecasts resulting from the addition of these data to the numerical analysis is recorded.

  6. Buoyancy-driven convective motion in a thermal diffusion cloud chamber using a water\\/helium mixture

    Microsoft Academic Search

    Françoise Utheza; Dorothée Sénechal; François Garnier

    2009-01-01

    This work is focused on a 2D numerical simulation of a thermal diffusion cloud chamber (TDCC) operating with water–helium mixture. We particularly address the impact of the stability of the vapor–gas mixture with respect to buoyancy-driven convective motion on homogeneous water nucleation rates. A comparison of our model results with Heist and Reiss results of nucleation of water in helium

  7. Clouds

    NSDL National Science Digital Library

    In this scenario-based, problem-based learning (PBL) activity, students investigate cloud formation, cloud classification, and the role of clouds in heating and cooling the Earth; how to interpret TRMM (Tropical Rainfall Measuring Mission) images and data; and the role clouds play in the Earth’s radiant budget and climate. Students assume the role of weather interns in a state climatology office and assist a frustrated student in a homework assignment. Learning is supported by a cloud in a bottle and an ice-albedo demonstration, a three-day cloud monitoring outdoor activity, and student journal assignments. The hands-on activities require two 2-liter soda bottles, an infrared heat lamp, and two thermometers. The resource includes a teacher's guide, questions and answer key, assessment rubric, glossary, and an appendix with information supporting PBL in the classroom.

  8. Correlation of Damage of Steel Moment-Resisting Frames to a Vector-valued Ground Motion Parameter Set that includes Energy Demands: Collaborative Research of the

    E-print Network

    Manuel, Lance

    Correlation of Damage of Steel Moment-Resisting Frames to a Vector-valued Ground Motion Parameter Luco (AIR) Keywords: Structural building response; strong ground motion; probabilistic seismic hazard-based quantities. The final purpose is to improve the prediction of structural behavior during earthquakes. A more

  9. THIRD-EPOCH MAGELLANIC CLOUD PROPER MOTIONS. I. HUBBLE SPACE TELESCOPE/WFC3 DATA AND ORBIT IMPLICATIONS

    SciTech Connect

    Kallivayalil, Nitya [Yale Center for Astronomy and Astrophysics, 260 Whitney Ave, New Haven, CT 06511 (United States)] [Yale Center for Astronomy and Astrophysics, 260 Whitney Ave, New Haven, CT 06511 (United States); Van der Marel, Roeland P.; Anderson, Jay [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)] [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Besla, Gurtina [Columbia Astrophysics Laboratory, 1027 Pupin Hall, MC 5247, New York, NY 10027 (United States)] [Columbia Astrophysics Laboratory, 1027 Pupin Hall, MC 5247, New York, NY 10027 (United States); Alcock, Charles, E-mail: nitya.kallivayalil@yale.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)] [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2013-02-20

    We present proper motions for the Large and Small Magellanic Clouds (LMC and SMC) based on three epochs of Hubble Space Telescope data, spanning a {approx}7 yr baseline, and centered on fields with background QSOs. The first two epochs, the subject of past analyses, were obtained with ACS/HRC, and have been reanalyzed here. The new third epoch with WFC3/UVIS increases the time baseline and provides better control of systematics. The three-epoch data yield proper-motion random errors of only 1%-2% per field. For the LMC this is sufficient to constrain the internal proper-motion dynamics, as will be discussed in a separate paper. Here we focus on the implied center-of-mass proper motions: {mu} {sub W,LMC} = -1.910 {+-} 0.020 mas yr{sup -1}, {mu} {sub N,LMC} = 0.229 {+-} 0.047 mas yr{sup -1}, and {mu} {sub W,SMC} = -0.772 {+-} 0.063 mas yr{sup -1}, {mu} {sub N,SMC} = -1.117 {+-} 0.061 mas yr{sup -1}. We combine the results with a revised understanding of the solar motion in the Milky Way to derive Galactocentric velocities: v {sub tot,LMC} = 321 {+-} 24 km s{sup -1} and v {sub tot,SMC} = 217 {+-} 26 km s{sup -1}. Our proper-motion uncertainties are now dominated by limitations in our understanding of the internal kinematics and geometry of the Clouds, and our velocity uncertainties are dominated by distance errors. Orbit calculations for the Clouds around the Milky Way allow a range of orbital periods, depending on the uncertain masses of the Milky Way and LMC. Periods {approx}< 4 Gyr are ruled out, which poses a challenge for traditional Magellanic Stream models. First-infall orbits are preferred (as supported by other arguments as well) if one imposes the requirement that the LMC and SMC must have been a bound pair for at least several Gyr.

  10. Neuro-fuzzy based Motion Control of a Robotic Exoskeleton: Considering End-effector Force Vectors

    Microsoft Academic Search

    Kazuo Kiguchi; Mohammad Habibur Rahman; Makoto Sasaki

    2006-01-01

    To assist physically disabled, injured, and\\/or elderly persons, we have been developing a 3DOF exoskeleton robot for assisting upper-limb motion, since upper-limb motion is involved in a lot of activities of everyday life. The exoskeleton robot is mainly is controlled by the skin surface electromyogram (EMG) signals, since EMG signals of muscles directly reflect how the user intends to move.

  11. Imaging the outward motions of clumpy dust clouds around the red supergiant Antares with VLT/VISIR

    NASA Astrophysics Data System (ADS)

    Ohnaka, K.

    2014-08-01

    Aims: We present a 0."5-resolution 17.7 ?m image of the red supergiant Antares. Our aim is to study the structure of the circumstellar envelope in detail. Methods: Antares was observed at 17.7 ?m with the VLT mid-infrared instrument VISIR. Taking advantage of the BURST mode, in which a large number of short exposure frames are taken, we obtained a diffraction-limited image with a spatial resolution of 0."5. Results: The VISIR image shows six clumpy dust clouds located at 0."8-1."8 (43-96 R? = 136-306 AU) away from the star. We also detected compact emission within a radius of 0."5 around the star. Comparison of our VISIR image taken in 2010 and the 20.8 ?m image taken in 1998 with the Keck Telescope reveals the outward motions of four dust clumps. The proper motions of these dust clumps (with respect to the central star) amount to 0."2-0."6 in 12 years. This translates into expansion velocities (projected onto the plane of the sky) of 13-40 km s-1 with an uncertainty of ± 7 km s-1. The inner compact emission seen in the 2010 VISIR image is presumably newly formed dust, because it is not detected in the image taken in 1998. If we assume that the dust is ejected in 1998, the expansion velocity is estimated to be 34 km s-1, in agreement with the velocity of the outward motions of the clumpy dust clouds. The mass of the dust clouds is estimated to be (3-6) × 10-9 M?. These values are lower by a factor of 3-7 than the amount of dust ejected in one year estimated from the (gas+dust) mass-loss rate of 2 × 10-6 M? yr-1, suggesting that the continuous mass loss is superimposed on the clumpy dust cloud ejection. Conclusions: The clumpy dust envelope detected in the 17.7 ?m diffraction-limited image is similar to the clumpy or asymmetric circumstellar environment of other red supergiants. The velocities of the dust clumps cannot be explained by a simple accelerating outflow, implying the possible random nature of the dust cloud ejection mechanism. Based on VISIR observations made with the Very Large Telescope of the European Southern Observatory. Program ID: 385.D-0120(A), 286.D-5007(A).

  12. Large-scale Environmental Variables and Transition to Deep Convection in Cloud Resolving Model Simulations: A Vector Representation

    SciTech Connect

    Hagos, Samson M.; Leung, Lai-Yung R.

    2012-11-01

    Cloud resolving model simulations and vector analysis are used to develop a quantitative method of assessing regional variations in the relationships between various large-scale environmental variables and the transition to deep convection. Results of the CRM simulations from three tropical regions are used to cluster environmental conditions under which transition to deep convection does and does not take place. Projections of the large-scale environmental variables on the difference between these two clusters are used to quantify the roles of these variables in the transition to deep convection. While the transition to deep convection is most sensitive to moisture and vertical velocity perturbations, the details of the profiles of the anomalies vary from region to region. In comparison, the transition to deep convection is found to be much less sensitive to temperature anomalies over all three regions. The vector formulation presented in this study represents a simple general framework for quantifying various aspects of how the transition to deep convection is sensitive to environmental conditions.

  13. Elucidation of Intersection Distribution in Motion Vectors from Successive Echocardiograms and its Application for Heart Diseases

    NASA Astrophysics Data System (ADS)

    Masuda, Kohji; Takahashi, Rui; Uchibori, Shun; Matsuura, Hirotaka; Yoshinaga, Takashi

    The expertise and experience are required for an examiner to diagnose using echocardiogram. To evaluate the malfunction of motion in the heart, many research of image processing method have developed but they were useful only for expert examiners. To bring benefit of portability in echography to wider medical staff, we have developed software to recognize the synchronous motion of heart by calculating intersection points between the instantaneous velocities of ventricular wall flow from successive echocardiograms. In addition, we defined intersection index to evaluate synchronous motion of heart by dividing echogram into small regions to calculate distribution of intersection points. Finally we introduced gravity point of the distribution and calculated its trajectory through a heartbeat. As the result, fluctuation of the gravity point in heart disease patients was strongly observed where the trajectory of the gravity point was stable in normal subjects.

  14. Motion of a Vector Particle in a Curved Space-time. IV. Asymptotical shape of caustic

    E-print Network

    A. T. Muminov; Z. Ya. Turakulov

    2007-06-26

    The studies of influence of spin on a photon motion in a Schwartzschild spacetime is continued. In the previous paper [2] the first order correction to the geodesic motion is reduced to a non-uniform linear ordinary differential equation and the equation obtained has been solved by the standard method of integration of the Green function. If each photon draws a world line specified by this solution then light rays from infinitely distant source form a caustic which does not appear without the spin-gravity interaction. The goal of the present work is to obtain explicit form of caustic.

  15. Structure and Semi-Fluid Motion Analysis of Stereoscopic Satellite Images for Cloud Tracking

    Microsoft Academic Search

    Kannappan Palaniappan; Chandra Kambhamettu; Frederick Hasler; Dmitry B. GoldgofS

    1995-01-01

    Time-varying multispectral observations of cloudsfrom meteorological satellites are used to estimatecloud-top heights (structure) and cloud winds (semifluidmotion). Stereo image pairs over several timesteps were acquired by two geostationary satellites withsynchronized scanning instruments. Cloud-top heightestimation from these image pairs is performed usingan improved automatic stereo analysis algorithm on amassively parallel Maspar computer with 16K processors.A new category of...

  16. Constants of motion for the planar orbit of a charged particle in a static and uniform magnetic field: the magnetic Laplace-Runge-Lenz vector

    NASA Astrophysics Data System (ADS)

    Velasco-Martínez, D.; Ibarra-Sierra, V. G.; Sandoval-Santana, J. C.; Kunold, A.; Cardoso, J. L.

    2014-09-01

    In this paper we introduce an alternative approach to studying the motion of a planar charged particle subject to a static uniform magnetic field. It is well known that an electric charge under a uniform magnetic field has a planar motion if its initial velocity is perpendicular to the magnetic field. Although some constants of motion (CsM), as the energy and the angular momentum, have been widely discussed for this system, others have been neglected. We find that the angular momentum, the generator of the magnetic translations and the magnetic Laplace-Runge-Lenz vector are CsM for this particular system. We show also that these three quantities form an orthogonal basis of vectors. The present work addresses many aspects of the motion of a charged particle in a magnetic field that should be useful for students and tutors of the classical mechanics courses at the senior undergraduate level.

  17. On motion of the eccentricity vector for IRS-1A and 1B

    NASA Astrophysics Data System (ADS)

    Nagarajan, N.; Jayashree, M. S.

    1992-07-01

    Based on the differential equations for the perturbations in eccentricity e and perigee omega due to J2 and J3, an analytical solution is obtained for the time history of e and omega. The analytical solution is first validated with the numerical solution. Using the definitive orbital data of IRS-1A and IRS-1B for about 4.5 months, it is shown that the analytical solution fairly represents real-world data. The error function is observed to have a periodicity equal to the periodicity of the eccentricity vector itself.

  18. Third-epoch Magellanic Cloud Proper Motions. II. The Large Magellanic Cloud Rotation Field in Three Dimensions

    NASA Astrophysics Data System (ADS)

    van der Marel, Roeland P.; Kallivayalil, Nitya

    2014-02-01

    We present the first detailed assessment of the large-scale rotation of any galaxy based on full three-dimensional velocity measurements. We do this for the LMC by combining our Hubble Space Telescope average proper motion (PM) measurements for stars in 22 fields, with existing line-of-sight (LOS) velocity measurements for 6790 individual stars. We interpret these data with a model of circular rotation in a flat disk. The PM and LOS data paint a consistent picture of the LMC rotation, and their combination yields several new insights. The PM data imply a stellar dynamical center that coincides with the H I dynamical center, and a rotation curve amplitude consistent with that inferred from LOS velocity studies. The implied disk viewing angles agree with the range of values found in the literature, but continue to indicate variations with stellar population and/or radius. Young (red supergiant) stars rotate faster than old (red and asymptotic giant branch) stars due to asymmetric drift. Outside the central region, the circular velocity is approximately flat at V circ = 91.7 ± 18.8 km s-1. This is consistent with the baryonic Tully-Fisher relation and implies an enclosed mass M(8.7 kpc) = (1.7 ± 0.7) × 1010 M ?. The virial mass is larger, depending on the full extent of the LMC's dark halo. The tidal radius is 22.3 ± 5.2 kpc (24.°0 ± 5.°6). Combination of the PM and LOS data yields kinematic distance estimates for the LMC, but these are not yet competitive with other methods.

  19. Aerosol-cloud interactions in ship tracks using Terra MODIS/MISR

    NASA Astrophysics Data System (ADS)

    Chen, Yi-Chun; Christensen, Matthew W.; Diner, David J.; Garay, Michael J.

    2015-04-01

    Simultaneous ship track observations from Terra Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging Spectroradiometer (MISR) have been compiled to investigate how ship-injected aerosols affect marine warm boundary layer clouds for different cloud types and environmental conditions. By taking advantage of the high spatial resolution multiangle observations available from MISR, we utilized the retrieved cloud albedo, cloud top height, and cloud motion vectors to examine cloud property responses in ship-polluted and nearby unpolluted clouds. The strength of the cloud albedo response to increased aerosol level is primarily dependent on cloud cell structure, dryness of the free troposphere, and boundary layer depth, corroborating a previous study by Chen et al. (2012) where A-Train satellite data were utilized. Under open cell cloud structure the cloud properties are more susceptible to aerosol perturbations as compared to closed cells. Aerosol plumes caused an increase in liquid water amount (+38%), cloud top height (+13%), and cloud albedo (+49%) for open cell clouds, whereas for closed cell clouds, little change in cloud properties was observed. Further capitalizing on MISR's unique capabilities, the MISR cross-track cloud speed was used to derive cloud top divergence. Statistically averaging the results from the identified plume segments to reduce random noise, we found evidence of cloud top divergence in the ship-polluted clouds, whereas the nearby unpolluted clouds showed cloud top convergence, providing observational evidence of a change in local mesoscale circulation associated with enhanced aerosols. Furthermore, open cell polluted clouds revealed stronger cloud top divergence as compared to closed cell clouds, consistent with different dynamical mechanisms driving their responses. These results suggest that detailed cloud responses, classified by cloud type and environmental conditions, must be accounted for in global climate modeling studies to reduce uncertainties in calculations of aerosol indirect forcing.

  20. Continuum regime motion of a growing droplet in opposing thermo-diffusiophoretic and gravitational fields of a thermal diffusion cloud chamber

    Microsoft Academic Search

    S. P. Bakanov; J. Smol??k; Sh. Kh. Zaripov; V. Žd??mal

    2001-01-01

    A model for the motion of aerosol particles by Stefan flow, thermo-diffusiophoresis and gravity in a continuum regime is described, which considers a phase change on the particle surface. It is tested in a thermal diffusion cloud chamber where a droplet formed by nucleation quickly grows and simultaneously moves upwards due to vertical temperature and concentration gradients. Kinetic coefficients are

  1. Motional displacements in proteins: The origin of wave-vector-dependent values

    NASA Astrophysics Data System (ADS)

    Vural, Derya; Hong, Liang; Smith, Jeremy C.; Glyde, Henry R.

    2015-05-01

    The average mean-square displacement, , of H atoms in a protein is frequently determined using incoherent neutron-scattering experiments. is obtained from the observed elastic incoherent dynamic structure factor, Si(Q ,? =0 ) , assuming the form Si(Q ,? =0 ) =exp(-Q2 /3 ) . This is often referred to as the Gaussian approximation (GA) to Si(Q ,? =0 ) . obtained in this way depends on the value of the wave vector, Q considered. Equivalently, the observed Si(Q ,? =0 ) deviates from the GA. We investigate the origin of the Q dependence of by evaluating the scattering functions in different approximations using molecular dynamics (MD) simulation of the protein lysozyme. We find that keeping only the Gaussian term in a cumulant expansion of S (Q ,? ) is an accurate approximation and is not the origin of the Q dependence of . This is demonstrated by showing that the term beyond the Gaussian is negligible and that the GA is valid for an individual atom in the protein. Rather, the Q dependence (deviation from the GA) arises from the dynamical heterogeneity of the H in the protein. Specifically it arises from representing, in the analysis of data, this diverse dynamics by a single average scattering center that has a single, average . The observed Q dependence of can be used to provide information on the dynamical heterogeneity in proteins.

  2. THE M31 VELOCITY VECTOR. I. HUBBLE SPACE TELESCOPE PROPER-MOTION MEASUREMENTS

    SciTech Connect

    Sohn, Sangmo Tony; Anderson, Jay; Van der Marel, Roeland P., E-mail: tsohn@stsci.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2012-07-01

    We present the first proper-motion (PM) measurements for the galaxy M31. We obtained new V-band imaging data with the Hubble Space Telescope ACS/WFC and the WFC3/UVIS instruments of three fields: a spheroid field near the minor axis, an outer disk field along the major axis, and a field on the Giant Southern Stream. The data provide five to seven year time baselines with respect to pre-existing deep first-epoch observations of the same fields. We measure the positions of thousands of M31 stars and hundreds of compact background galaxies in each field. High accuracy and robustness is achieved by building and fitting a unique template for each individual object. The average PM for each field is obtained from the average motion of the M31 stars between the epochs with respect to the background galaxies. For the three fields, the observed PMs ({mu}{sub W}, {mu}{sub N}) are, in units of mas yr{sup -1}, (- 0.0458, -0.0376) {+-} (0.0165, 0.0154), (- 0.0533, -0.0104) {+-} (0.0246, 0.0244), and (- 0.0179, -0.0357) {+-} (0.0278, 0.0272), respectively. The ability to average over large numbers of objects and over the three fields yields a final displacement accuracy of a few thousandths of a pixel, corresponding to only 12 {mu}as yr{sup -1}. This is comparable to what has been achieved for other Local Group galaxies using Very Long Baseline Array observations of water masers. Potential systematic errors are controlled by an analysis strategy that corrects for detector charge transfer inefficiency, spatially and time-dependent geometric distortion, and point-spread function variations. The robustness of the PM measurements and uncertainties are supported by the fact that data from different instruments, taken at different times and with different telescope orientations, as well as measurements of different fields, all yield statistically consistent results. Papers II and III of this series explore the implications of the new measurements for our understanding of the history, future, and mass of the Local Group.

  3. Motion.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    2002-01-01

    This issue of Exploratorium Magazine focuses on the topic of motion. Contents include: (1) "First Word" (Zach Tobias); (2) "Cosmic Collisions" (Robert Irion); (3) "The Mobile Cell" (Karen E. Kalumuck); (4) "The Paths of Paths" (Steven Vogel); (5) "Fragments" (Pearl Tesler); (6) "Moving Pictures" (Amy Snyder); (7) "Plants on the Go" (Katharine…

  4. Motion.

    ERIC Educational Resources Information Center

    Gerhart, James B.; Nussbaum, Rudi H.

    This monograph was written for the Conference on the New Instructional Materials in Physics held at the University of Washington in summer, 1965. It is intended for use in an introductory course in college physics. It consists of an extensive qualitative discussion of motion followed by a detailed development of the quantitative methods needed to…

  5. Aerosol-Cloud Interactions in Ship Tracks Using Terra MODIS/MISR

    NASA Astrophysics Data System (ADS)

    Chen, Y. C.; Christensen, M.; Diner, D. J.; Garay, M. J.; Nelson, D. L.

    2014-12-01

    Simultaneous ship track observations from Terra Moderate Resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging SpectroRadiometer (MISR) have been compiled to investigate how ship-injected aerosols affect marine warm boundary layer clouds under different cloud types and environmental conditions. Taking advantage of the high spatial resolution multiangle observations uniquely available from MISR, we utilized the retrieved cloud albedo, cloud top height, and cloud motion vectors to examine the cloud property responses in ship-polluted and nearby unpolluted clouds. The strength of cloud albedo response to increased aerosol level is primarily dependent on cloud cell structure, dryness of the free troposphere, and boundary layer depth, corroborating a previous study by Chen et al. (2012) where A-Train satellite data were applied. Under open cell cloud structure, the cloud properties are more susceptible to aerosol perturbations as compared to closed cells. Aerosol plumes caused an increase in liquid water amount (+27%), cloud top height (+11%), and cloud albedo (+40%) for open cell clouds, whereas under closed cell clouds, little changes in cloud properties were observed. Further capitalizing on MISR's unique capabilities, the MISR cross-track cloud speed has been used to derive cloud top divergence. Statistically averaging the results from many plume segments to reduce random noise, we have found that in ship-polluted clouds there is stronger cloud top divergence, and in nearby unpolluted clouds, convergence occurs and leads to downdrafts, providing observational evidence for cloud top entrainment feedback. These results suggest that detailed cloud responses, classified by cloud type and environmental conditions, must be accounted for in global climate modeling studies to reduce uncertainties of aerosol indirect forcing. Reference: Chen, Y.-C. et al. Occurrence of lower cloud albedo in ship tracks, Atmos. Chem. Phys., 12, 8223-8235, doi:10.5194/acp-12-8223-2012, 2012.

  6. Last developments of the EUMETSAT Atmospheric Motion Vector product derived from MSG images for assimilation in NWP models

    NASA Astrophysics Data System (ADS)

    Borde, Regis; Bertil Gustafsson, Jörgen; de Smet, Arthur; Dew, Greg

    2010-05-01

    Atmospheric Motion Vectors (AMVs) are one of the most important products derived from all geostationary satellites, because they constitute a very important part of the observation data provided to Numerical Weather Prediction models. The Height Assignment (HA) is currently the most difficult task in the AMV extraction scheme. Several sources of error can be introduced at the height assignment step, but one of the main difficulties is to clearly identify the pixels that lead the tracking process in the tracer box, in order to select them for the HA calculation. A good pixel selection process should ensure to keep a direct link between the feature really tracked and the calculation of the height. The most common method sorts the coldest pixels in the target box and uses them to calculate the AMV height. However, recent work showed that some of the coldest pixels can have very small and/or negative contribution to the cross correlation process. Following these findings, it is then proposed to use individual pixel contribution to the cross correlation coefficient information in the pixel selection process, in order to get a closer link between the tracked feature tracked and the HA. This method has been tested on a parallel chain at EUMETSAT for two separated periods of one month. This presentation summarizes the main results of these operational tests, which show some improvements of the new scheme on the AMV product for both the VIS0.8, HRV and IR10.8 channels, increasing the total amount of good AMVs (Quality Index QI>80) and also the amount of good AMV/radiosonde collocations. Speed biases and RMS against radiosonde observations are generally a bit larger, especially the known slow bias observed at high levels for IR10.8 AMVs, but are calculated on a bigger amount of data.

  7. Influence of the cosmological constant on the motion of Magellanic Clouds in the gravitational field of Milky Way

    SciTech Connect

    Stuchlík, Zden?k; Schee, Jan, E-mail: zdenek.stuchlik@fpf.slu.cz, E-mail: jan.schee@fpf.slu.cz [Institute of Physics, Faculty of Philosophy and Science, Silesian University in Opava, Bezrucovo nám. 13, Opava (Czech Republic)

    2011-09-01

    Using the pseudo-Newtonian (PN) potential reflecting properties of the Schwarz-schild-de Sitter spacetime, we estimate the influence of the repulsive cosmological constant ? ? 1.3 × 10{sup ?56}cm{sup ?2} implied by recent cosmological tests onto the motion of both Small and Large Magellanic Clouds (SMC and LMC) in the gravitational field of the Milky Way. Considering detailed modelling of the gravitational field of the Galaxy disc, bulge and cold dark matter halo, the trajectories of SMC and LMC constructed for the PN potential with the cosmological constant are confronted to those given for ? = 0. In the realistic model of the extended cold dark matter halo its edge and related total mass are taken at typical values reflecting recent diversity in the total Galaxy mass estimates. In all cases, strong influence of the cosmological constant, on 10% level or higher, has been found for motion of both SMC and LMC. Inside the halo, the Newtonian part of the PN potential is exact enough, while outside the halo the PN potential can give relevant relativistic corrections. The role of the cosmological constant is most conspicuous when binding mass is estimated for the satellite galaxies. We have found a strong influence of cosmic repulsion on the total binding mass for both galaxies. For SMC there is the binding mass M{sub SMC}{sup ?=0} = 7.07 × 10{sup 11}M{sub ?} and M{sub SMC}{sup ?>0} = 8.61 × 10{sup 11}M{sub ?}, while even much higher increase is found for LMC, where M{sub LMC}{sup ?=0} = 1.50 × 10{sup 12}M{sub ?} and M{sub LMC}{sup ?} {sup >0} = 2.21 × 10{sup 12}M{sub ?}, putting serious doubts on the possibility that the LMC is bounded by the Milky Way. However, the estimates of binding masses are strongly influenced by initial velocity of SMC and LMC; we took the values inferred for the IAU MW rotation velocity ? 220 km/s. Our results indicate very important role of the cosmic repulsion in the motion of interacting galaxies, clearly demonstrated in the case of the satellite SMC and LMC galaxies moving in the field of Milky Way. In some cases, the effect of the cosmic repulsion can be even comparable to the effects of the dynamical friction and the Andromeda Galaxy.

  8. Invariant conformal vectors in space-times admitting a group of G/sub 3/ of motions acting on spacelike orbits S/sub 2/

    SciTech Connect

    Bona, C.

    1988-11-01

    The paper deals with four-dimensional space-times admitting locally a three-dimensional group of motions G/sub 3/ acting on two-dimensional spacelike orbits S/sub 2/. The local existence problem for conformal vectors invariant under G/sub 3/ is shown to be equivalent to the local existence problem for Killing vectors of a given two-dimensional pseudo-Riemannian metric g. This problem is explicitly solved in terms of the Gaussian curvature R of g and two of its scalar differential concomitants. The results are applied to the case of dust-filled space-times, where an exhaustive list of metrics has been obtained by using the algebraic computing language Sm-smcapsp-smcaps.-smcaps The metrics are either homogeneous, self-similar, or Friedmann models.

  9. Implementation of a state of the art automated system for the production of cloud/water vapor motion winds from geostationary satellites

    NASA Technical Reports Server (NTRS)

    Velden, Christopher

    1995-01-01

    The research objectives in this proposal were part of a continuing program at UW-CIMSS to develop and refine an automated geostationary satellite winds processing system which can be utilized in both research and operational environments. The majority of the originally proposed tasks were successfully accomplished, and in some cases the progress exceeded the original goals. Much of the research and development supported by this grant resulted in upgrades and modifications to the existing automated satellite winds tracking algorithm. These modifications were put to the test through case study demonstrations and numerical model impact studies. After being successfully demonstrated, the modifications and upgrades were implemented into the NESDIS algorithms in Washington DC, and have become part of the operational support. A major focus of the research supported under this grant attended to the continued development of water vapor tracked winds from geostationary observations. The fully automated UW-CIMSS tracking algorithm has been tuned to provide complete upper-tropospheric coverage from this data source, with data set quality close to that of operational cloud motion winds. Multispectral water vapor observations were collected and processed from several different geostationary satellites. The tracking and quality control algorithms were tuned and refined based on ground-truth comparisons and case studies involving impact on numerical model analyses and forecasts. The results have shown the water vapor motion winds are of good quality, complement the cloud motion wind data, and can have a positive impact in NWP on many meteorological scales.

  10. Automatic generation of time resolved motion vector fields of coronary arteries and 4D surface extraction using rotational x-ray angiography.

    PubMed

    Jandt, Uwe; Schäfer, Dirk; Grass, Michael; Rasche, Volker

    2009-01-01

    Rotational coronary angiography provides a multitude of x-ray projections of the contrast agent enhanced coronary arteries along a given trajectory with parallel ECG recording. These data can be used to derive motion information of the coronary arteries including vessel displacement and pulsation. In this paper, a fully automated algorithm to generate 4D motion vector fields for coronary arteries from multi-phase 3D centerline data is presented. The algorithm computes similarity measures of centerline segments at different cardiac phases and defines corresponding centerline segments as those with highest similarity. In order to achieve an excellent matching accuracy, an increasing number of bifurcations is included as reference points in an iterative manner. Based on the motion data, time-dependent vessel surface extraction is performed on the projections without the need of prior reconstruction. The algorithm accuracy is evaluated quantitatively on phantom data. The magnitude of longitudinal errors (parallel to the centerline) reaches approx. 0.50 mm and is thus more than twice as large as the transversal 3D extraction errors of the underlying multi-phase 3D centerline data. It is shown that the algorithm can extract asymmetric stenoses accurately. The feasibility on clinical data is demonstrated on five different cases. The ability of the algorithm to extract time-dependent surface data, e.g. for quantification of pulsating stenosis is demonstrated. PMID:19060360

  11. The motion of charged dust particles in interplanetary space. I - The zodiacal dust cloud. II - Interstellar grains

    Microsoft Academic Search

    G. E. Morfill; E. Gruen

    1979-01-01

    The problem of electromagnetic perturbations of charged dust particle orbits in interplanetary space was reexamined in the light of the large scale spatial and temporal interplanetary plasma and field topology. Using analytical and numerical solutions for particle propagation it was shown that: (1) stochastic variations induced by electromagnetic forces are unimportant for the zodiacal dust cloud except for the lowest

  12. Applications of the TIROS-N sounding and cloud motion wind enhancement for the FGGE 'special effort'. [Global Weather Experiment

    NASA Technical Reports Server (NTRS)

    Atlas, R.

    1980-01-01

    In January of 1978, a panel of experts recommended that a 'special effort' be made to enhance and edit satellite soundings and cloud tracked winds in data sparse regions. It was felt that these activities would be necessary to obtain maximum benefits from an evaluation of satellite data during the Global Weather Experiment (FGGE). The 'special effort' is being conducted for the two special observing periods of FGGE. More than sixty cases have been selected for enhancement on the basis of meteorological interest. These cases include situations of blocking, cutoff low development, cyclogenesis, and tropical circulations. The sounding data enhancement process consists of supplementing the operational satellite sounding data set with higher resolution soundings in meteorologically active regions, and with new soundings where data voids or soundings of questionable quality exist.

  13. Exploring acceleration through vectors

    NSDL National Science Digital Library

    This in class worksheet is designed to get students to think about and manipulate different accelerations in their head. Students work together with written descriptions of velocity and acceleration and draw the vectors in part one, and then turn that around in part two where they write descriptions of a car's motion based on the vector pictures they are given.

  14. New MISR Cloud Data

    Atmospheric Science Data Center

    2013-08-06

    ... (MISR) project and the NASA Langley Atmospheric Science Data Center (ASDC) announce the release of a new science data product, ... heights at 1.1 km resolution; and cross-track cloud motion components at 1.1 km resolution. Additional parameters include cloud masks and ...

  15. Southern Clouds

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03026 Southern Clouds

    This image shows a system of clouds just off the margin of the South Polar cap. Taken during the summer season, these clouds contain both water-ice and dust.

    Image information: VIS instrument. Latitude 80.2S, Longitude 57.6E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  16. Linear Clouds

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA03667 Linear Clouds

    These clouds are located near the edge of the south polar region. The cloud tops are the puffy white features in the bottom half of the image.

    Image information: VIS instrument. Latitude -80.1N, Longitude 52.1E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  17. Clouds as Turbulent Density Fluctuations: Implications for Pressure Confinement and Spectral Line Data Interpretation

    NASA Astrophysics Data System (ADS)

    Ballesteros-Paredes, Javier; Vázquez-Semadeni, Enrique; Scalo, John

    1999-04-01

    We examine the idea that diffuse H I and giant molecular clouds and their substructure form as density fluctuations induced by large-scale interstellar turbulence. We do this by closely investigating the topology of the velocity, density, and magnetic fields within and at the boundaries of the clouds emerging in high-resolution two-dimensional simulations of the interstellar medium (ISM) including self-gravity, magnetic fields, parameterized heating and cooling, and a simple model for star formation. We find that the velocity field is continuous across cloud boundaries for a hierarchy of clouds of progressively smaller sizes. Cloud boundaries defined by a density-threshold criterion are found to be quite arbitrary, with no correspondence to any actual physical boundary, such as a density discontinuity. Abrupt velocity jumps are coincident with the density maxima, which indicates that the clouds are formed by colliding gas streams. This conclusion is also supported by the fact that the volume and surface kinetic terms in the Eulerian virial theorem for a cloud ensemble are comparable in general and by the topology of the magnetic field, which exhibits bends and reversals where the gas streams collide. However, no unique trend of alignment between density and magnetic features is observed. Both sub- and super-Alfvénic motions are observed within the clouds. In light of these results, we argue that thermal pressure equilibrium is irrelevant for cloud confinement in a turbulent medium, since inertial motions can still distort or disrupt a cloud, unless it is strongly gravitationally bound. Turbulent pressure confinement appears self-defeating because turbulence contains large-scale motions that necessarily distort Lagrangian cloud boundaries or equivalently cause flux through Eulerian boundaries. We then discuss the compatibility of the present scenario with observational data. We find that density-weighted velocity histograms are consistent with observational line profiles of comparable spatial and velocity resolution, exhibiting similar FWHMs and similar multicomponent structure. An analysis of the regions contributing to each velocity interval indicates that the histogram ``features'' do not come from isolated ``clumps'' but rather from extended regions throughout a cloud, which often have very different total velocity vectors. Finally, we argue that the scenario presented here may also be applicable to small scales with larger densities (molecular clouds and their substructure, up to at least n~103-105 cm-3) and conjecture that quasi-hydrostatic configurations cannot be produced from turbulent fluctuations unless the thermodynamic behavior of the flow becomes nearly adiabatic. We demonstrate, using appropriate cooling rates, that this will not occur except for very small compressions (<~10-2 pc) or until protostellar densities are reached for collapse.

  18. Vector Introduction Vector components and example machines

    E-print Network

    California at Berkeley, University of

    vector 1 Vector Introduction Lecture 10 2/21/96 vector 2 Outline Motivation Vector components and example machines Vector instructions & vector program Vector Execution Vector Load/Store Units Vector Length, Stride, Strip Mining Vector Optimizations: Chaining, Gather/Scatter, Conditional Vector Metrics

  19. Vector Addition and the Speeding Ticket.

    ERIC Educational Resources Information Center

    Brown, Nathan

    1993-01-01

    Discusses the teaching of vectors and the inadequate and inappropriate examples given in many textbooks. Suggests using the motion of a sailboat or the motion of a car moving on the Earth's surface as possible examples. Details a proper vector teaching example. (MVL)

  20. Optimal Exploitation of the Temporal and Spatial Resolution of SEVIRI for the Nowcasting of Clouds

    NASA Astrophysics Data System (ADS)

    Sirch, Tobias; Bugliaro, Luca

    2015-04-01

    Optimal Exploitation of the Temporal and Spatial Resolution of SEVIRI for the Nowcasting of Clouds An algorithm was developed to forecast the development of water and ice clouds for the successive 5-120 minutes separately using satellite data from SEVIRI (Spinning Enhanced Visible and Infrared Imager) aboard Meteosat Second Generation (MSG). In order to derive cloud cover, optical thickness and cloud top height of high ice clouds "The Cirrus Optical properties derived from CALIOP and SEVIRI during day and night" (COCS, Kox et al. [2014]) algorithm is applied. For the determination of the liquid water clouds the APICS ("Algorithm for the Physical Investigation of Clouds with SEVIRI", Bugliaro e al. [2011]) cloud algorithm is used, which provides cloud cover, optical thickness and effective radius. The forecast rests upon an optical flow method determining a motion vector field from two satellite images [Zinner et al., 2008.] With the aim of determining the ideal time separation of the satellite images that are used for the determination of the cloud motion vector field for every forecast horizon time the potential of the better temporal resolution of the Meteosat Rapid Scan Service (5 instead of 15 minutes repetition rate) has been investigated. Therefore for the period from March to June 2013 forecasts up to 4 hours in time steps of 5 min based on images separated by a time interval of 5 min, 10 min, 15 min, 30 min have been created. The results show that Rapid Scan data produces a small reduction of errors for a forecast horizon up to 30 minutes. For the following time steps forecasts generated with a time interval of 15 min should be used and for forecasts up to several hours computations with a time interval of 30 min provide the best results. For a better spatial resolution the HRV channel (High Resolution Visible, 1km instead of 3km maximum spatial resolution at the subsatellite point) has been integrated into the forecast. To detect clouds the difference of the measured albedo from SEVIRI and the clear-sky albedo provided by MODIS has been used and additionally the temporal development of this quantity. A pre-requisite for this work was an adjustment of the geolocation accuracy for MSG and MODIS by shifting the MODIS data and quantifying the correlation between both data sets.

  1. Crater Clouds

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA06085 Crater Clouds

    The crater on the right side of this image is affecting the local wind regime. Note the bright line of clouds streaming off the north rim of the crater.

    Image information: VIS instrument. Latitude -78.8N, Longitude 320.0E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  2. On the accuracy of approximation of a small celestial body motion using intermediate perturbed orbits calculated from two position vectors and three observations

    NASA Astrophysics Data System (ADS)

    Shefer, V. A.; Shefer, O. V.

    2015-01-01

    We examine intermediate perturbed orbits proposed by the first author previously, defined from the two position vectors and three angular coordinates of a small celestial body. It is shown theoretically, that at a small reference time interval covering the measurements the approximation accuracy of real movements by these orbits corresponds approximately to the third order of osculation. The smaller reference interval of time, the better this correspondence. Laws of variation of the methodical errors in constructing intermediate orbits subject to the length of reference time interval are deduced. According to these laws, the convergence rate of the methods to the exact solution (upon reducing the reference interval of time) is higher by two orders of magnitude than in the case of conventional methods using the Keplerian unperturbed orbit. The considered orbits are among the most accurate in set of orbits of their class determined by the order of osculation. The theoretical results are validated by numerical examples.

  3. A vector-dyadic development of the equations of motion for N-coupled flexible bodies and point masses. [spacecraft trajectories

    NASA Technical Reports Server (NTRS)

    Frisch, H. P.

    1975-01-01

    The equations of motion for a system of coupled flexible bodies, rigid bodies, point masses, and symmetric wheels were derived. The equations were cast into a partitioned matrix form in which certain partitions became nontrivial when the effects of flexibility were treated. The equations are shown to contract to the coupled rigid body equations or expand to the coupled flexible body equations all within the same basic framework. Furthermore, the coefficient matrix always has the computationally desirable property of symmetry. Making use of the derived equations, a comparison was made between the equations which described a flexible body model and those which described a rigid body model of the same elastic appendage attached to an arbitrary coupled body system. From the comparison, equivalence relations were developed which defined how the two modeling approaches described identical dynamic effects.

  4. A Porn Video Detecting Method Based on Motion Features Using HMM

    Microsoft Academic Search

    Zhiyi Qu; Yanmin Liu; Ying Liu; Kang Jiu; Yong Chen

    2009-01-01

    This paper proposes a method of identified reciprocating motion in pornographic video from other human action using Hidden Markov Model (HMM). The motion vectors are obtained by decoding the compressed MPEG video. Then the feature vectors are extracted by calculating the direction and the magnitude of the motion vectors. The feature vectors are fed to Hidden Markov Model for training

  5. Scanning Backscatter Lidar Observations for Characterizing 4-D Cloud and Aerosol Fields to Improve Radiative Transfer Parameterizations

    NASA Technical Reports Server (NTRS)

    Schwemmer, Geary K.; Miller, David O.

    2005-01-01

    Clouds have a powerful influence on atmospheric radiative transfer and hence are crucial to understanding and interpreting the exchange of radiation between the Earth's surface, the atmosphere, and space. Because clouds are highly variable in space, time and physical makeup, it is important to be able to observe them in three dimensions (3-D) with sufficient resolution that the data can be used to generate and validate parameterizations of cloud fields at the resolution scale of global climate models (GCMs). Simulation of photon transport in three dimensionally inhomogeneous cloud fields show that spatial inhomogeneities tend to decrease cloud reflection and absorption and increase direct and diffuse transmission, Therefore it is an important task to characterize cloud spatial structures in three dimensions on the scale of GCM grid elements. In order to validate cloud parameterizations that represent the ensemble, or mean and variance of cloud properties within a GCM grid element, measurements of the parameters must be obtained on a much finer scale so that the statistics on those measurements are truly representative. High spatial sampling resolution is required, on the order of 1 km or less. Since the radiation fields respond almost instantaneously to changes in the cloud field, and clouds changes occur on scales of seconds and less when viewed on scales of approximately 100m, the temporal resolution of cloud properties should be measured and characterized on second time scales. GCM time steps are typically on the order of an hour, but in order to obtain sufficient statistical representations of cloud properties in the parameterizations that are used as model inputs, averaged values of cloud properties should be calculated on time scales on the order of 10-100 s. The Holographic Airborne Rotating Lidar Instrument Experiment (HARLIE) provides exceptional temporal (100 ms) and spatial (30 m) resolution measurements of aerosol and cloud backscatter in three dimensions. HARLIE was used in a ground-based configuration in several recent field campaigns. Principal data products include aerosol backscatter profiles, boundary layer heights, entrainment zone thickness, cloud fraction as a function of altitude and horizontal wind vector profiles based on correlating the motions of clouds and aerosol structures across portions of the scan. Comparisons will be made between various cloud detecting instruments to develop a baseline performance metric.

  6. Cloud Protocols

    NSDL National Science Digital Library

    The GLOBE Program, UCAR (University Corporation for Atmospheric Research)

    2003-08-01

    The purpose of this activity is to observe the type and cover of clouds including contrails. Students observe which of ten types of clouds and how many of three types of contrails are visible and how much of the sky is covered by clouds (other than contrails) and how much is covered by contrails. Intended outcomes are that students learn how to make estimates from observations and how to categorize specific clouds following general descriptions for the categories. They will learn the meteorological concepts of cloud heights, types, and cloud cover and learn the ten basic cloud types. Supporting background materials for both student and teacher are included.

  7. A method for reciprocating motion detection in porn video based on motion features

    Microsoft Academic Search

    Qu Zhiyi; Liu Yanmin; Liu Ying; Jiu Kang; Chen Yong

    2009-01-01

    This paper presents a new algorithm for detecting the human's reciprocating motion in pornographic videos. First, the motion vector is extracted from mpeg video stream and pretreated so that the motion features are extracted by analyzing the motion rule of the objectionable videos. Then the whole videos are detected through setting a threshold. Experimental results demonstrate that the correct recognition

  8. The Influence of Shear Motion on Evolution of Giant Molecular Associations

    NASA Astrophysics Data System (ADS)

    Miyamoto, Y.; Nakai, N.; Kuno, N.

    2014-03-01

    The evolution of Giant Molecular Clouds (GMCs) and Giant Molecular Associations (GMAs) is one of the keys to understand massive star formation in a galaxy and hence evolution of the galaxy. It has been considered that GMCs and GMAs are formed in spiral arms. Recently, however, GMCs are found not only in the spiral arms but also in the inter-arms. It is suggested that the GMCs in the inter-arms might be formed by the shear motion. However, the relation between molecular clouds and the kinetic shear motion in the clouds is still speculation, because the kinetic shear has not been directly measured in a galaxy. We have investigated the dynamics of the molecular gas and the evolution of GMAs in the spiral galaxy M51 with the NRO 45-m telescope. The velocity components of the molecular gas perpendicular and parallel to the spiral arms were derived at each spiral phase from the distribution of the line-of-sight velocity of the CO gas. The shear motion in the galactic disk was determined from the velocity vectors at each spiral phase. It was revealed that the distributions of the shear strength and of GMAs are anti-correlated. In addition, GMAs can grow up just in regions where the gravitational critical density is larger than the critical shear density. This result suggests that the evolution of GMAs is heavily affected by the shear.

  9. A Catalog of HI Clouds in the Large Magellanic Cloud

    E-print Network

    S. Kim; E. Rosolowsky; Y. Lee; Y. Kim; Y. C. Jung; M. A. Dopita; B. G. Elmegreen; K. C. Freeman; R. J. Sault; M. J. Kesteven; D. McConnell; Y. -H. Chu

    2007-06-28

    A 21 cm neutral hydrogen interferometric survey of the Large Magellanic Cloud (LMC) combined with the Parkes multi-beam HI single-dish survey clearly shows that the HI gas is distributed in the form of clumps or clouds. The HI clouds and clumps have been identified using a thresholding method with three separate brightness temperature thresholds ($T_b$). Each catalog of HI cloud candidates shows a power law relationship between the sizes and the velocity dispersions of the clouds roughly following the Larson Law scaling $\\sigma_v \\propto R^{0.5}$, with steeper indices associated with dynamically hot regions. The clouds in each catalog have roughly constant virial parameters as a function mass suggesting that that the clouds are all in roughly the same dynamical state, but the values of the virial parameter are significantly larger than unity showing that turbulent motions dominate gravity in these clouds. The mass distribution of the clouds is a power law with differential indices between -1.6 and -2.0 for the three catalogs. In contrast, the distribution of mean surface densities is a log-normal distribution.

  10. Cloud Diagram

    NSDL National Science Digital Library

    This interactive diagram shows the various types of clouds and the relative altitudes at which they occur. Users can roll their mice over each cloud type and see a photo and a brief written description of each type.

  11. Cloud Computing

    SciTech Connect

    Pete Beckman and Ian Foster

    2009-12-04

    Chicago Matters: Beyond Burnham (WTTW). Chicago has become a world center of "cloud computing." Argonne experts Pete Beckman and Ian Foster explain what "cloud computing" is and how you probably already use it on a daily basis.

  12. 1D Uniformly Accelerated Motion

    NSDL National Science Digital Library

    The representation depicts an object moving along a "track" marked in .5 meter intervals. As the object moves, displacement-time, velocity-time, and acceleration-time graphs record the motion in real time. The user may select various types of motion to be depicted, as well as edit a velocity-time graph and have the resulting motion depicted. As the object moves, color coded vectors display its displacement, velocity and acceleration.

  13. Vector quantization

    Microsoft Academic Search

    Robert M. Gray

    1984-01-01

    A vector quantizer is a system for mapping a sequence of continuous or discrete vectors into a digital sequence suitable for communication over or storage in a digital channel. The goal of such a system is data compression: to reduce the bit rate so as to minimize communication channel capacity or digital storage memory requirements while maintaining the necessary fidelity

  14. Cloud Watch

    NSDL National Science Digital Library

    The GLOBE Program, UCAR (University Corporation for Atmospheric Research)

    2003-08-01

    The purpose of this activity is to explore the connections between cloud type, cloud cover, and weather and stimulate student interest in taking cloud type observations. Students observe cloud type and coverage and weather conditions over a five-day period and correlate these observations. Students make and test predictions using these observations. The intended outcome is that students learn to draw inferences from observations and use them to make and test predictions.

  15. Multiscale Cloud System Modeling

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Moncrieff, Mitchell W.

    2009-01-01

    The central theme of this paper is to describe how cloud system resolving models (CRMs) of grid spacing approximately 1 km have been applied to various important problems in atmospheric science across a wide range of spatial and temporal scales and how these applications relate to other modeling approaches. A long-standing problem concerns the representation of organized precipitating convective cloud systems in weather and climate models. Since CRMs resolve the mesoscale to large scales of motion (i.e., 10 km to global) they explicitly address the cloud system problem. By explicitly representing organized convection, CRMs bypass restrictive assumptions associated with convective parameterization such as the scale gap between cumulus and large-scale motion. Dynamical models provide insight into the physical mechanisms involved with scale interaction and convective organization. Multiscale CRMs simulate convective cloud systems in computational domains up to global and have been applied in place of contemporary convective parameterizations in global models. Multiscale CRMs pose a new challenge for model validation, which is met in an integrated approach involving CRMs, operational prediction systems, observational measurements, and dynamical models in a new international project: the Year of Tropical Convection, which has an emphasis on organized tropical convection and its global effects.

  16. Cloud Types

    NSDL National Science Digital Library

    2005-01-01

    This resource describes cloud formation and explains atmospheric processes such as convection, evaporation, and transpiration. The discussion includes how clouds form, some of their properties, and how precipitation is triggered. A multimedia interactive feature explains how clouds are named and identified. Questions for discussion are provided.

  17. Interactive physically-based cloud simulation 

    E-print Network

    Overby, Derek Robert

    2002-01-01

    computational fluid solver. This allows us to simulate the complex air motion that contributes to cloud formation in our atmosphere. Among the natural processes that we simulate are buoyancy, relative humidity, and condensation. Because we have built...

  18. The Physics Classroom: Vectors - Fundamentals and Operations

    NSDL National Science Digital Library

    2004-12-14

    This interactive tutorial provides comprehensive help and practice in understanding vector quantities. It is organized into six sections: vector direction, vector addition, resultants, components, vector resolution, and component addition. It closes with relative velocity and riverboat problems, plus a discussion of the interdependence of perpendicular components of motion. Each section explains a topic and provides exercises for learner self-assessment. Images, animations, and graphs are placed throughout to illustrate the concepts. Editor's Note: Fluency in vector operations requires practice, and this tutorial provides it. Additional guidance is offered by clicking "Student Extras" at the top of the tutorial page.

  19. Determination of Optical Flow on General Object Motion

    Microsoft Academic Search

    Zhaoxin Pan

    1991-01-01

    Optical flow is the foundation of vision to obtain motion information. So far, researchers have focused on rigid object motion because of the smoothness assumption. Here we relax this restriction and extend the research to a general world including non-rigid object motion, of which clouds are a typical example. We analyze the physical principles of object motion and propose a

  20. Motion Segmentation and Tracking Using Normalized Cuts

    Microsoft Academic Search

    Jianbo Shi; Jitendra Malik

    1998-01-01

    We propose a motion segmentation algorithm thataims to break a scene into its most prominent movinggroups. A weighted graph is constructed on theimage sequence by connecting pixels that are in thespatiotemporal neighborhood of each other. At eachpixel, we define motion profile vectors which capturethe probability distribution of the image velocity. Thedistance between motion profiles is used to assign aweight on

  1. Vector Fields

    NSDL National Science Digital Library

    Dray, Tevian

    2006-01-01

    Vector fields are vectors which change from point to point. A standard example is the velocity of moving air, in other words, wind. For instance, the current wind pattern in the San Francisco area can be found at . This site has a 2-dimensional representation; careful reading of the webpage will tell you at what elevation the wind is shown. How would you represent a vector field in 3 dimensions? What features are important? Some simple examples are shown. Each can be rotated by clicking and dragging with the mouse. Explore!

  2. Cloning vector

    DOEpatents

    Guilfoyle, R.A.; Smith, L.M.

    1994-12-27

    A vector comprising a filamentous phage sequence containing a first copy of filamentous phage gene X and other sequences necessary for the phage to propagate is disclosed. The vector also contains a second copy of filamentous phage gene X downstream from a promoter capable of promoting transcription in a bacterial host. In a preferred form of the present invention, the filamentous phage is M13 and the vector additionally includes a restriction endonuclease site located in such a manner as to substantially inactivate the second gene X when a DNA sequence is inserted into the restriction site. 2 figures.

  3. Dynamics of Finite Dust Clouds in a Magnetized Anodic Plasma

    SciTech Connect

    Piel, A.; Pilch, I.; Trottenberg, T. [Institute for Experimental and Applied Physics, Christian-Albrechts University, D-24098 Kiel (Germany); Koepke, M. E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26505-6315 (United States)

    2008-09-07

    The response to an external modulation voltage of small dust clouds confined in an anodic plasma is studied. Dust density waves are excited when the cloud is larger than a wavelength, whereas a sloshing and stretching motion is found for smaller clouds. The wave dispersion shows similarities with waveguide modes.

  4. EDITORIAL: Focus on Cloud Physics FOCUS ON CLOUD PHYSICS

    NASA Astrophysics Data System (ADS)

    Falkovich, Gregory; Malinowski, Szymon P.

    2008-07-01

    Cloud physics has for a long time been an important segment of atmospheric science. It is common knowledge that clouds are crucial for our understanding of weather and climate. Clouds are also interesting by themselves (not to mention that they are beautiful). Complexity is hidden behind the common picture of these beautiful and interesting objects. The typical school textbook definition that a cloud is 'a set of droplets or particles suspended in the atmosphere' is not adequate. Clouds are complicated phenomena in which dynamics, turbulence, microphysics, thermodynamics and radiative transfer interact on a wide range of scales, from sub-micron to kilometres. Some of these interactions are subtle and others are more straightforward. Large and small-scale motions lead to activation of cloud condensation nuclei, condensational growth and collisions; small changes in composition and concentration of atmospheric aerosol lead to significant differences in radiative properties of the clouds and influence rainfall formation. It is justified to look at a cloud as a composite, nonlinear system which involves many interactions and feedback. This system is actively linked into a web of atmospheric, oceanic and even cosmic interactions. Due to the complexity of the cloud system, present-day descriptions of clouds suffer from simplifications, inadequate parameterizations, and omissions. Sometimes the most fundamental physics hidden behind these simplifications and parameterizations is not known, and a wide scope of view can sometimes prevent a 'microscopic', deep insight into the detail. Only the expertise offered by scientists focused on particular elementary processes involved in this complicated pattern of interactions allows us to shape elements of the puzzle from which a general picture of clouds can be created. To be useful, every element of the puzzle must be shaped precisely. This often creates problems in communication between the sciences responsible for shaping elements of the puzzle, and those which combine them. Scales, assumptions and the conditions used in order to describe a particular single process of interest must be consistent with the conditions in clouds. The papers in this focus issue of New Journal of Physics collectively demonstrate (i) the variation in scientific approaches towards investigating cloud processes, (ii) the various stages of shaping elements of the puzzle, and (iii) some attempts to put the pieces together. These papers present just a small subset of loosely arranged elements in an initial stage of puzzle creation. Addressed by this issue is one of the important problems in our understanding of cloud processes—the interaction between cloud particles and turbulence. There is currently a gap between the cloud physics community and scientists working in wind tunnels, on turbulence theory and particle interactions. This collection is intended to narrow this gap by bringing together work by theoreticians, modelers, laboratory experimentalists and those who measure and observe actual processes in clouds. It forms a collage of contributions showing various approaches to cloud processes including: • theoretical works with possible applications to clouds (Bistagnino and Boffetta, Gustavsson et al), • an attempt to construct a phenomenological description of clouds and rain (Lovejoy and Schertzer), • simplified models designed to parameterize turbulence micro- and macro-effects (Celani et al, Derevyanko et al), • focused theoretical research aimed at particular cloud processes (Ayala et al, parts I and II, Wang et al), • laboratory and modeling studies of complex cloud processes (Malinowski et al). This collage is far from being complete but, hopefully, should give the reader a representative impression of the current state of knowledge in the field. We hope it will be useful to all scientists whose work is inspired by cloud processes. Focus on Cloud Physics Contents The development of ice in a cumulus cloud over southwest England Yahui Huang, Alan M Blyth, Philip R A Brown, Tom W Choularton,

  5. Vector quantization

    NASA Technical Reports Server (NTRS)

    Gray, Robert M.

    1989-01-01

    During the past ten years Vector Quantization (VQ) has developed from a theoretical possibility promised by Shannon's source coding theorems into a powerful and competitive technique for speech and image coding and compression at medium to low bit rates. In this survey, the basic ideas behind the design of vector quantizers are sketched and some comments made on the state-of-the-art and current research efforts.

  6. Venus: cloud level circulation during 1982 as determined from Pioneer cloud photopolarimeter images. I. Time and zonally averaged circulation

    SciTech Connect

    Limaye, S.S.; Grassotti, C.; Kuetemeyer, M.J.

    1988-02-01

    Significant mean cloud level circulation changes since 1974, noted in 1982 Venus cloud motion observations, have been validated by independent measurements of cloud motions in nearly-identical sets of images; agreement is obtained not only for the average zonal and meridional components, but for the eddy circulation's meridional transport of momentum. In contrast to 1979 observations, the time latitudinal profile and the longitudinally-averaged zonal component of the cloud motions for 1982 exhibit jets near 45 deg latitude in both the northern and southern hemispheres. 30 references.

  7. 6 STAR FORMATION Molecular Clouds and Initial Cloud

    E-print Network

    Sitko, Michael L.

    turbulence. Any net motion in the blob will cause the collapse in the central regions to be non-spherical due;3 Visually, these regions consist of dark clouds that, due to the extinction from the dust, block the light in dark gray, and Mask 0 in light gray. We also show the 156 stellar members of Taurus compiled by Luhman

  8. ARM Data for Cloud Parameterization

    SciTech Connect

    Xu, Kuan-Man

    2006-10-02

    The PI's ARM investigation (DE-IA02-02ER633 18) developed a physically-based subgrid-scale saturation representation that fully considers the direct interactions of the parameterized subgrid-scale motions with subgrid-scale cloud microphysical and radiative processes. Major accomplishments under the support of that interagency agreement are summarized in this paper.

  9. Motion Analysis Motion detection

    E-print Network

    Hamburg,.Universität

    of moving objects by - finding "interest points" in all frames of a sequence - determining to motion Moving object detection and tracking Detect individual moving objects, determine and predict object trajectories, track objects with a moving camera Derivation of 3D object properties Determine 3D

  10. Cloud Types

    NSDL National Science Digital Library

    This table provides a quick reference to cloud types. Clouds are divided into groups mainly based on the height of the cloud's base above the Earth's surface. The table further divides the types according to group, atmospheric layer, and base height. Links to additional information are embedded in the text, and users can select beginner, intermediate, or advanced levels of difficulty. A Spanish translation is available.

  11. Observe Clouds

    NSDL National Science Digital Library

    If you observe clouds in a portion of the sky, you may notice that they are not static. Clouds are composed of tiny particles of water and are constantly changing and moving. This video lets viewers observe clouds forming, moving, and changing shape. The segment is one minute thirty-three seconds in length. A background essay and list of discussion questions are also provided.

  12. Beyond pixels : exploring new representations and applications for motion analysis

    E-print Network

    Liu, Ce, Ph. D. Massachusetts Institute of Technology

    2009-01-01

    The focus of motion analysis has been on estimating a flow vector for every pixel by matching intensities. In my thesis, I will explore motion representations beyond the pixel level and new applications to which these ...

  13. Navigational Vectors

    NSDL National Science Digital Library

    2008-12-10

    This is a high school instructional unit that features nine lessons relating to vectors. Students build understanding of vector properties as they learn airplane navigation. Problem-based learning activities include reading real-time weather maps, tracking airplanes flying in U.S. skies, calculating vector components, analyzing effects of wind velocity, and completing training segments similar to a private pilot certification program. Participants have access to help from experts at the Polaris Career Center. Comprehensive teacher guides, student guides, reference materials, and assessments are included. This resource was developed by the Center for Innovation in Science and Engineering Education (CIESE). Participation is cost-free; additional options are available for registered users.

  14. Seeing Motion

    NSDL National Science Digital Library

    The Concord Consortium

    2011-12-11

    Explore your own straight-line motion using a motion sensor to generate distance versus time graphs of your own motion. Learn how changes in speed and direction affect the graph, and gain an understanding of how motion can be represented on a graph.

  15. Motion Commotion

    NSDL National Science Digital Library

    Integrated Teaching and Learning Program,

    Students learn why and how motion occurs and what governs changes in motion, as described by Newton's three laws of motion. They gain hands-on experience with the concepts of forces, changes in motion, and action and reaction. In an associated literacy activity, students design a behavioral survey and learn basic protocol for primary research, survey design and report writing.

  16. Cloud Computing For Bioinformatics

    E-print Network

    Ferrara, Katherine W.

    Cloud Computing For Bioinformatics #12;Cloud Computing: what is it? · Cloud Computing Computing abstracts infrastructure from application. · Cloud Computing should save you time the way software & deploy your application Cloud Computing #12;Advantages: ­ Reliability: Decoupling applications from

  17. Cloud Computing

    E-print Network

    Mirashe, Shivaji P

    2010-01-01

    Computing as you know it is about to change, your applications and documents are going to move from the desktop into the cloud. I'm talking about cloud computing, where applications and files are hosted on a "cloud" consisting of thousands of computers and servers, all linked together and accessible via the Internet. With cloud computing, everything you do is now web based instead of being desktop based. You can access all your programs and documents from any computer that's connected to the Internet. How will cloud computing change the way you work? For one thing, you're no longer tied to a single computer. You can take your work anywhere because it's always accessible via the web. In addition, cloud computing facilitates group collaboration, as all group members can access the same programs and documents from wherever they happen to be located. Cloud computing might sound far-fetched, but chances are you're already using some cloud applications. If you're using a web-based email program, such as Gmail or Ho...

  18. Cloud Cover

    ERIC Educational Resources Information Center

    Schaffhauser, Dian

    2012-01-01

    This article features a major statewide initiative in North Carolina that is showing how a consortium model can minimize risks for districts and help them exploit the advantages of cloud computing. Edgecombe County Public Schools in Tarboro, North Carolina, intends to exploit a major cloud initiative being refined in the state and involving every…

  19. Cloud Control

    ERIC Educational Resources Information Center

    Ramaswami, Rama; Raths, David; Schaffhauser, Dian; Skelly, Jennifer

    2011-01-01

    For many IT shops, the cloud offers an opportunity not only to improve operations but also to align themselves more closely with their schools' strategic goals. The cloud is not a plug-and-play proposition, however--it is a complex, evolving landscape that demands one's full attention. Security, privacy, contracts, and contingency planning are all…

  20. Pipeline vectorization

    Microsoft Academic Search

    Markus Weinhardt; Wayne Luk

    2001-01-01

    This paper presents pipeline vectorization, amethod for synthesizing hardware pipelines based on softwarevectorizing compilers. The method improves eciencyand ease of development of hardware designs, particularlyfor users with little electronics design experience. We proposeseveral loop transformations to customize pipelinesto meet hardware resource constraints, while maximizingavailable parallelism. For run-time recongurable systems,we apply hardware specialization to increase...

  1. Cloud Computing Fundamentals

    NASA Astrophysics Data System (ADS)

    Furht, Borko

    In the introductory chapter we define the concept of cloud computing and cloud services, and we introduce layers and types of cloud computing. We discuss the differences between cloud computing and cloud services. New technologies that enabled cloud computing are presented next. We also discuss cloud computing features, standards, and security issues. We introduce the key cloud computing platforms, their vendors, and their offerings. We discuss cloud computing challenges and the future of cloud computing.

  2. Scalar-Tensor-Vector Gravity Theory

    E-print Network

    J. W. Moffat

    2005-12-11

    A covariant scalar-tensor-vector gravity theory is developed which allows the gravitational constant $G$, a vector field coupling $\\omega$ and the vector field mass $\\mu$ to vary with space and time. The equations of motion for a test particle lead to a modified gravitational acceleration law that can fit galaxy rotation curves and cluster data without non-baryonic dark matter. The theory is consistent with solar system observational tests. The linear evolutions of the metric, vector field and scalar field perturbations and their consequences for the observations of the cosmic microwave background are investigated.

  3. Magnetohydrodynamic stability of broad line region clouds

    NASA Astrophysics Data System (ADS)

    Krause, Martin; Schartmann, Marc; Burkert, Andreas

    2012-10-01

    Hydrodynamic stability has been a longstanding issue for the cloud model of the broad line region in active galactic nuclei. We argue that the clouds may be gravitationally bound to the supermassive black hole. If true, stabilization by thermal pressure alone becomes even more difficult. We further argue that if magnetic fields are present in such clouds at a level that could affect the stability properties, they need to be strong enough to compete with the radiation pressure on the cloud. This would imply magnetic field values of a few gauss for a sample of active galactic nuclei we draw from the literature. We then investigate the effect of several magnetic configurations on cloud stability in axisymmetric magnetohydrodynamic simulations. For a purely azimuthal magnetic field which provides the dominant pressure support, the cloud first gets compressed by the opposing radiative and gravitational forces. The pressure inside the cloud then increases, and it expands vertically. Kelvin-Helmholtz and column density instabilities lead to a filamentary fragmentation of the cloud. This radiative dispersion continues until the cloud is shredded down to the resolution level. For a helical magnetic field configuration, a much more stable cloud core survives with a stationary density histogram which takes the form of a power law. Our simulated clouds develop sub-Alfvénic internal motions on the level of a few hundred km s-1.

  4. Fragmentation of Cloud Core or Protoplanetary Disk

    NASA Astrophysics Data System (ADS)

    Matsumoto, Tomoaki; Hanawa, Tomoyuki

    We investigate collapse and fragmentation of molecular cloud cores by using three-dimensional numerical simulations. To resolve fine structures in the central clouds we adopt nested grids. For models of molecular cloud cores we focus on gas clouds in nearly equilibrium at the initial stage. We find conditions for fragmentation by parameter survey changing the initial rotation and amplitudes of perturbations. When the initial cloud rotates fast sufficiently to form a flat disk during the isothermal collapse the first core fragments. The fragmentation process depends on the initial amplitude of bar mode and the rotation law of the cloud. When the initial cloud has no bar mode the cloud collapse to form a ring. The ring deforms to a bar and the bar fragments when the initial cloud rotates rigidly. On the other hand the ring fragments when the initial cloud rotates differentially. When the initial cloud has large amplitude of the bar mode the narrow bar forms during the collapse. Though the bar fragments into cores they merge to form a central core. In the further stages satellite cores form around the central core. Their orbital motion is chaotic and several cores survive in their orbital evolution

  5. APPENDIX D. VECTOR ANALYSIS 1 Vector Analysis

    E-print Network

    Callen, James D.

    APPENDIX D. VECTOR ANALYSIS 1 Appendix D Vector Analysis The following conventions are used in this appendix and throughout the book: f, g, , are scalar functions of x, t; A, B, C, D are vector functions of x, t; A = |A| A · A is the magnitude or length of the vector A; ^eA A/A is a unit vector

  6. Cloud Games

    NSDL National Science Digital Library

    University Corporation for Atmospheric Research - Education and Outreach Programs

    2010-01-01

    Play these two matching games from the Web Weather for Kids site to pair cloud images with their names/types! Developed by the University Corporation for Atmospheric Research, this site requires Java.

  7. Observing atmospheric clouds through stereo reconstruction

    NASA Astrophysics Data System (ADS)

    Öktem, Ru?en; Romps, David M.

    2015-03-01

    Observing cloud lifecycles and obtaining measurements on cloud features are significant problems in atmospheric cloud research. Scanning radars have been the most capable instruments to provide such measurements, but they have shortcomings when it comes to spatial and temporal resolution. High spatial and temporal resolution is particularly important to capture the variations in developing convections. Stereo photogrammetry can complement scanning radars with the potential to observe clouds as distant as tens of kilometers and to provide high temporal and spatial resolution, although it comes with the calibration challenges peculiar to various outdoor settings required to collect measurements on atmospheric clouds. This work explores the use of stereo photogrammetry in atmospheric cloud research, focusing on tracking vertical motion in developing convections. Calibration challenges and strategies to overcome these challenges are addressed within two different stereo settings in Miami, Florida and in the plains of Oklahoma. A feature extraction and matching algorithm is developed and implemented to identify cloud features of interest. A two-level resolution hierarchy is exploited in feature extraction and matching. 3D positions of cloud features are reconstructed from matched pixel pairs, and cloud tops of developing turrets in shallow to deep convection are tracked in time to estimate vertical accelerations. Results show that stereophotogrammetry provides a useful tool to observe cloud lifecycles and track the vertical acceleration of turrets exceeding 10 km height.

  8. CLOUD CONDENSATION NUCLEI MEASUREMENTS WITHIN CLOUDS

    EPA Science Inventory

    Measurements of the spectra of cloud condensation nuclei (CCN) within and near the boundaries of clouds are presented. Some of the in-cloud measurements excluded the nuclei within cloud droplets (interstitial CCN) while others included all nuclei inside the cloud (total CCN). The...

  9. Plate motion

    SciTech Connect

    Gordon, R.G. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

    1991-01-01

    The motion of tectonic plates on the earth is characterized in a critical review of U.S. research from the period 1987-1990. Topics addressed include the NUVEL-1 global model of current plate motions, diffuse plate boundaries and the oceanic lithosphere, the relation between plate motions and distributed deformations, accelerations and the steadiness of plate motions, the distribution of current Pacific-North America motion across western North America and its margin, plate reconstructions and their uncertainties, hotspots, and plate dynamics. A comprehensive bibliography is provided. 126 refs.

  10. Seeing liquids from visual motion.

    PubMed

    Kawabe, Takahiro; Maruya, Kazushi; Fleming, Roland W; Nishida, Shin'ya

    2015-04-01

    Most research on human visual recognition focuses on solid objects, whose identity is defined primarily by shape. In daily life, however, we often encounter materials that have no specific form, including liquids whose shape changes dynamically over time. Here we show that human observers can recognize liquids and their viscosities solely from image motion information. Using a two-dimensional array of noise patches, we presented observers with motion vector fields derived from diverse computer rendered scenes of liquid flow. Our observers perceived liquid-like materials in the noise-based motion fields, and could judge the simulated viscosity with surprising accuracy, given total absence of non-motion information including form. We find that the critical feature for apparent liquid viscosity is local motion speed, whereas for the impression of liquidness, image statistics related to spatial smoothness-including the mean discrete Laplacian of motion vectors-is important. Our results show the brain exploits a wide range of motion statistics to identify non-solid materials. PMID:25102388

  11. Successive elimination algorithm for motion estimation

    Microsoft Academic Search

    Wenhua Li; Ezzatollah Salari

    1995-01-01

    The correspondence presents a fast exhaustive search algorithm for motion estimation. The basic idea is to obtain the best estimate of the motion vectors by successively eliminating the search positions in the search window and thus decreasing the number of matching evaluations that require very intensive computations. Simulation results demonstrate that although the performance of the proposed algorithm is the

  12. IEEE TRANSACTIONS ON SIGNAL PROCESSING, VOL. 45, NO. 10, OCTOBER 1997 2515 Neural Fuzzy Motion Estimation and Compensation

    E-print Network

    Kosko, Bart

    of the motion vectors give ellipsoidal search windows. This algorithm reduced the search area and entropy moves with uniform translational motion. This often does not hold and can produce block artifacts. We correlation of the motion field to estimate the motion vectors and to reduce the entropy of source coding

  13. Enhanced motion estimation algorithm with prefiltering in video compression

    NASA Astrophysics Data System (ADS)

    Jang, Jinik; Lee, Hyuk; Hong, Sun-Min; Jeong, Jechang

    2012-03-01

    We present an enhanced motion estimation and compensation algorithm by prefiltering reference frames before motion estimation. The conventional block based motion estimation algorithm gives poor performance when abrupt motion change occurs. The proposed algorithm constructs prefilters based on motion vector distribution analysis and compensates temporal sampling artifacts, such as blur or deblur, between adjacent frames. Compared to H.264/AVC, the proposed algorithm achieves significant bit-rate reduction up to 14.59%.

  14. Motion-assisted rate control for ME\\/MC-based codecs [video coding

    Microsoft Academic Search

    Gounyoung Kim; Yeong-yil Yang; Alexandros Eleftheriadis

    2005-01-01

    We propose motion-assisted rate control (MARC), a scheme that utilizes local statistics of motion vectors and motion-compensated error signals. Since human perception on macroblocks with motion is different from that on macroblocks that belong to static part of a frame, the usage of motion statistics can potentially provide useful information regarding how to distribute effectively the available bit budget. A

  15. Fusion of LIDAR Data and Large-scale Vector Maps for Building Reconstruction

    Microsoft Academic Search

    Liang-Chien Chen; Chih-Yi Kuo; Jiann-Yeou Rau; Chi-Heng Hsieh

    LIDAR data contains plenty of height information, while vector maps preserve accurate building boundaries. From the viewpoint of data fusion, we integrate LIDAR data and large-scale vector maps to perform building modeling. The proposed scheme comprises six major steps: (1) preprocessing of LIDAR data and vector maps, (2) extraction of point clouds that belong to a building, (3) construction of

  16. The mean-square error optimal linear discriminant function and its application to incomplete data vectors

    NASA Technical Reports Server (NTRS)

    Walker, H. F.

    1979-01-01

    In many pattern recognition problems, data vectors are classified although one or more of the data vector elements are missing. This problem occurs in remote sensing when the ground is obscured by clouds. Optimal linear discrimination procedures for classifying imcomplete data vectors are discussed.

  17. Curious About Clouds

    NSDL National Science Digital Library

    Ms. Stewart

    2010-03-24

    What are the characteristics of the 3 main types of clouds, and what weather does each of these clouds produce? 3 Main Types of Clouds Use this website to start learn about the 3 main types of clouds: Cumulus, Stratus, and Cirrus Use your cloud graphic organizer and fill in the three main types of clouds along with information describing them. Clouds Weather Video Watch this video to learn how clouds are formed and what happens ...

  18. Kinematic Analysis and Derivation of Equations of Motion for Mechanisms with Loops of Different Motion Spaces

    NASA Astrophysics Data System (ADS)

    Sugimoto, Koichi

    Kinematic analysis and derivation of equations of motion for a mechanism with loops of different motion spaces are developed. First, it is shown that screw coordinates of a joint which expresses relative motion between two links must be expressed by the basis vectors of motion spaces of the loops to which it belongs. Then, it becomes possible to derive the same number of linear equations for joint velocities and accelerations of a loop as the dimension of its motion space, and joint velocities and accelerations can be determined by solving these linear equations. Next, it is described that the force analysis can be performed by expressing the joint wrench as a linear combination of basis vectors of a reciprocal space of a motion space and other linearly independent screw coordinates. Using the developed theorem, the computational scheme for kinematic and force analysis is derived. The method to derive the equations of motion for a mechanism is also clarified.

  19. Neptune's clouds

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The bright cirrus-like clouds of Neptune change rapidly, often forming and dissipating over periods of several to tens of hours. In this sequence Voyager 2 observed cloud evolution in the region around the Great Dark Spot (GDS). The surprisingly rapid changes which occur separating each panel shows that in this region Neptune's weather is perhaps as dynamic and variable as that of the Earth. However, the scale is immense by our standards -- the Earth and the GDS are of similar size -- and in Neptune's frigid atmosphere, where temperatures are as low as 55 degrees Kelvin (-360 F), the cirrus clouds are composed of frozen methane rather than Earth's crystals of water ice. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications

  20. Cloud Formation

    NSDL National Science Digital Library

    This Classroom Connectors lesson plan teaches students how clouds are formed through the condensation of water vapor. This includes learning about climate types and how they change, the greenhouse effect, how clouds affect weather and climate, and condensation. The site provides goals, objectives, an outline, time required, materials, activities, and closure ideas for the lesson. The Classroom Connectors address content with an activity approach while incorporating themes necessary to raise the activity to a higher cognition level. The major motivation is to employ instructional strategies that bring the students physically and mentally into touch with the science they are studying.

  1. Cloud Identification

    NSDL National Science Digital Library

    2012-08-03

    In this online, interactive module, students learn about the ten common cloud types and how they are formed and how to identify different cloud types on satellite images. The module is part of an online course for grades 7-12 in satellite meteorology, which includes 10 interactive modules. The site also includes lesson plans developed by teachers and links to related resources. Each module is designed to serve as a stand-alone lesson, however, a sequential approach is recommended. Designed to challenge students through the end of 12th grade, middle school teachers and students may choose to skim or skip a few sections.

  2. Particle Cloud Flames in Acoustic Fields

    NASA Technical Reports Server (NTRS)

    Berlad, A. L.; Tangirala, V.; Ross, H.; Facca, L.

    1990-01-01

    Results are presented on a study of flames supported by clouds of particles suspended in air, at pressures about 100 times lower than normal. In the experiment, an acoustic driver (4-in speaker) placed at one end of a closed tube, 0.75-m long and 0.05 m in diameter, disperses a cloud of lycopodium particles during a 0.5-sec powerful acoustic burst. Properties of the particle cloud and the flame were recorded by high-speed motion pictures and optical transmission detectors. Novel flame structures were observed, which owe their features to partial confinement, which encourages flame-acoustic interactions, segregation of particle clouds into laminae, and penetration of the flame's radiative flux density into the unburned particle-cloud regimes. Results of these experiments imply that, for particles in confined spaces, uncontrolled fire and explosion may be a threat even if the Phi(0) values are below some apparent lean limit.

  3. The dynamics of periodically driven bubble clouds

    NASA Astrophysics Data System (ADS)

    Smereka, P.; Banerjee, S.

    1988-12-01

    An averaged two-fluid model is used to study the motion of a cloud of bubbles. The linearized equations of motion are shown to be a wave equation with both dissipation and dispersion. The fully nonlinear equations are also examined and it is demonstrated that the cutoff frequency of the cloud is equal to the natural frequency of a single bubble. The steady linear response of a periodically driven bubble cloud is then derived. Resonances are seen to arise when the driving frequency is below the cutoff frequency. The inner core of the cloud is shielded by an outer layer when the driving is above the cutoff frequency. The nonlinear dynamics of periodically driven bubble clouds is studied numerically. It is found that the cutoff frequency is crucial in determining whether or not the cloud will behave like a single bubble. Also, under some conditions the cloud is seen to behave like a damped and driven single-degree-of-freedom Hamiltonian system.

  4. Tectonic Plate Motion

    NSDL National Science Digital Library

    The representation shows the direction of motion of the Earth's major plates as measured through NASA's satellite laser ranging (SLR) technology. A series of world maps, accompanying text, and the subsequent links explain this technology in great detail. One can click on the Index Map for Satellite Laser Ranging site Velocity and see the vectors (arrows) that indicate the direction and rate of movement of Earth's plates in much more detail. Accompanying text gives a more detailed explanation of what each sub map is showing.

  5. The Vector Product Introduction

    E-print Network

    Vickers, James

    The Vector Product 9.4 Introduction In this section we describe how to find the vector product of two vectors. Like the scalar product its definition may seem strange when first met but the definition is chosen because of its many applications. When vectors are multiplied using the vector product the result

  6. Triboelectrification Based Motion Sensor for Human-Machine Interfacing

    E-print Network

    Wang, Zhong L.

    vector sensor,20 tactile sensor,21 tracking sensor,22 and acoustic sensor.23 It is known that human skinTriboelectrification Based Motion Sensor for Human-Machine Interfacing Weiqing Yang,,, Jun Chen electrode arrays as motion sensors for tracking muscle motion and human-machine interfacing (HMI

  7. Neutral cold gas (H atoms): HI clouds, 50% MISM

    E-print Network

    Estalella, Robert

    Neutral cold gas (H atoms): HI clouds, 50% MISM Tk = 100 K, n = 102 cm-3 observation: hyperfine transition of the fundamental level, F = 1-0 = 21 cm, = 1 420 405 751.786 Hz Interstellar Medium: HI clouds & Hindman (Sidney) Prediction and discovery of the HI 21 cm line #12;Radiative processes: thermal motion

  8. Seasonal variation and physical properties of the cloud system over southeastern China derived from CloudSat products

    NASA Astrophysics Data System (ADS)

    Guo, Zhun; Zhou, Tianjun

    2015-05-01

    Based on the National Centers for Environmental Prediction (NCEP) and Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) data and CloudSat products, the seasonal variations of the cloud properties, vertical occurrence frequency, and ice water content of clouds over southeastern China were investigated in this study. In the CloudSat data, a significant alternation in high or low cloud patterns was observed from winter to summer over southeastern China. It was found that the East Asian Summer Monsoon (EASM) circulation and its transport of moisture leads to a conditional instability, which benefits the local upward motion in summer, and thereby results in an increased amount of high cloud. The deep convective cloud centers were found to coincide well with the northward march of the EASM, while cirrus lagged slightly behind the convection center and coincided well with the outflow and meridional wind divergence of the EASM. Analysis of the radiative heating rates revealed that both the plentiful summer moisture and higher clouds are effective in destabilizing the atmosphere. Moreover, clouds heat the mid-troposphere and the cloud radiative heating is balanced by adiabatic cooling through upward motion, which causes meridional wind by the Sverdrup balance. The cloud heating-forced circulation was observed to coincide well with the EASM circulation, serving as a positive effect on EASM circulation.

  9. Autoadaptive monospectral cloud identification in Meteosat satellite images

    NASA Astrophysics Data System (ADS)

    Boekaerts, Piet; Nyssen, E.; Cornelis, Jan P.

    1995-11-01

    A non-supervised, autoadaptive cloud identification scheme for mono-spectral Meteosat data is presented. The identification of clouds is equivalent to the assignment of meteorological meaningful labels to cloud regions. Automated cloud region detection is reduced to the problem of finding an algorithm that performs a data reduction on Meteosat images while optimally preserving cloud region information. A self-organizing 1D feature map applied to random segments of individual Meteosat channels is shown to meet the requirements of such algorithm. A study of the segment size indicates that small segment sizes are sufficient and even better than large segment sizes for consistent mono-spectral cloud region detection. This is explained in terms of the statistical properties of Meteosat images and the structural features of the code vectors (code segments) in the topological map. Decreasing the number of code segments used to reduce the information content of Meteosat channels results in a systematic, consistent loss of cloud region information.

  10. Vectors: Tip to Tail

    NSDL National Science Digital Library

    Sharon Linamen

    2012-07-23

    In this lesson students will learn the characteristics and appropriate use of vectors. They will find the magnitude and direction of vectors, they will add and subtract vectors and use an interactive website to practice what they have learned.

  11. Characteristics of vector propagation channels in dynamic mobile scenarios

    Microsoft Academic Search

    Adnan Kavak; Weidong Yang; Guanghan Xu; Wolfhard J. Vogel

    2001-01-01

    In wireless communications, the performance of a smart antenna system depends heavily upon vector channels describing channel propagation between an antenna array and a mobile subscriber. The smart antennas perform quite well in stationary mobile environments in which channel propagation characteristics are stable. However, in dynamic wireless environments where the mobile user is in motion, knowledge of how vector channels

  12. Deep Convective Clouds

    NSDL National Science Digital Library

    Convective clouds are clouds that develop vertically appearing like big stacks of clouds. One very common example is cumulonimbus clouds. Convective clouds are commonly connected to stormy weather. Monthly Cloud Coverage for Deep Convective Cloud data can be used to predict patterns in weather. The specific pattern associated with this data is tracking and predicting thunderstorms. In this lesson, the students will take a look at the Monthly Cloud Coverage for Deep Convective Cloud data, and name one month of the year 'Thunderstorm Season' for their continent.

  13. The Structure of the Local Interstellar Medium IV: Dynamics, Morphology, Physical Properties, and Implications of Cloud-Cloud Interactions

    E-print Network

    Seth Redfield; Jeffrey L. Linsky

    2007-09-27

    We present an empirical dynamical model of the local interstellar medium based on 270 radial-velocity measurements for 157 sight lines toward nearby stars. Physical-parameter measurements (i.e., temperature, turbulent velocity, depletions) are available for 90 components, or one-third of the sample, enabling initial characterizations of the physical properties of LISM clouds. The model includes 15 warm clouds located within 15 pc of the Sun, each with a different velocity vector. We derive projected morphologies of all clouds and estimate the volume filling factor of warm partially ionized material in the LISM to be between ~5.5% and 19%. Relative velocities of potentially interacting clouds are often supersonic, consistent with heating, turbulent, and metal-depletion properties. Cloud-cloud collisions may be responsible for the filamentary morphologies found in ~1/3 of LISM clouds, the distribution of clouds along the boundaries of the two nearest clouds (LIC and G), the detailed shape and heating of the Mic Cloud, the location of nearby radio scintillation screens, and the location of a LISM cold cloud. Contrary to previous claims, the Sun appears to be located in the transition zone between the LIC and G Clouds.

  14. Estimating Cloud Cover

    ERIC Educational Resources Information Center

    Moseley, Christine

    2007-01-01

    The purpose of this activity was to help students understand the percentage of cloud cover and make more accurate cloud cover observations. Students estimated the percentage of cloud cover represented by simulated clouds and assigned a cloud cover classification to those simulations. (Contains 2 notes and 3 tables.)

  15. Cloud Computing Adam Barker

    E-print Network

    St Andrews, University of

    Cloud Computing 1 Adam Barker #12;Overview · Introduction to Cloud computing · Enabling / Constraints 2 #12;Cloud Computing · Cloud computing provides resizable computing capacity that enables users to build and host applications in a data centre · Cloud computing characteristics · Computing as a utility

  16. Wave Motion

    NSDL National Science Digital Library

    Carl R. (Rod) Nave

    This site from Carl Nave at Georgia State University presents a discussion of wave motion. The site explains the velocity of idealized ocean waves and details the measurement of large waves aboard the USS Ramapo.

  17. Fault Motion

    NSDL National Science Digital Library

    This collection of animations provides elementary examples of fault motion intended for simple demonstrations. Examples include dip-slip faults (normal and reverse), strike-slip faults, and oblique-slip faults.

  18. Characterization of free breathing patterns with 5D lung motion model

    SciTech Connect

    Zhao Tianyu; Lu Wei; Yang Deshan; Mutic, Sasa; Noel, Camille E.; Parikh, Parag J.; Bradley, Jeffrey D.; Low, Daniel A. [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States)

    2009-11-15

    Purpose: To determine the quiet respiration breathing motion model parameters for lung cancer and nonlung cancer patients. Methods: 49 free breathing patient 4DCT image datasets (25 scans, cine mode) were collected with simultaneous quantitative spirometry. A cross-correlation registration technique was employed to track the lung tissue motion between scans. The registration results were applied to a lung motion model: X-vector=X-vector{sub 0}+{alpha}-vector{beta}-vector f, where X-vector is the position of a piece of tissue located at reference position X-vector{sub 0} during a reference breathing phase (zero tidal volume v, zero airflow f). {alpha}-vector is a parameter that characterizes the motion due to air filling (motion as a function of tidal volume v) and {beta}-vector is the parameter that accounts for the motion due to the imbalance of dynamical stress distributions during inspiration and exhalation that causes lung motion hysteresis (motion as a function of airflow f). The parameters {alpha}-vector and {beta}-vector together provide a quantitative characterization of breathing motion that inherently includes the complex hysteresis interplay. The {alpha}-vector and {beta}-vector distributions were examined for each patient to determine overall general patterns and interpatient pattern variations. Results: For 44 patients, the greatest values of |{alpha}-vector| were observed in the inferior and posterior lungs. For the rest of the patients, |{alpha}-vector| reached its maximum in the anterior lung in three patients and the lateral lung in two patients. The hysteresis motion {beta}-vector had greater variability, but for the majority of patients, |{beta}-vector| was largest in the lateral lungs. Conclusions: This is the first report of the three-dimensional breathing motion model parameters for a large cohort of patients. The model has the potential for noninvasively predicting lung motion. The majority of patients exhibited similar |{alpha}-vector| maps and the |{beta}-vector| maps showed greater interpatient variability. The motion parameter interpatient variability will inform our need for custom radiation therapy motion models. The utility of this model depends on the parameter stability over time, which is still under investigation.

  19. Venus: cloud level circulation during 1982 as determined from Pioneer cloud photopolarimeter images. 11. Solar longitude dependent circulation

    SciTech Connect

    Limaye, S.S.

    1988-02-01

    Pioneer Venus Orbiter images obtained in 1982 indicate a marked solar-locked dependence of cloud level circulation in both averaged cloud motions and cloud layer UV reflectivity. An apparent relationship is noted between horizontal divergence and UV reflectivity: the highest reflectivities are associated with regions of convergence at high latitudes, while lower values are associated with equatorial latitude regions where the motions are divergent. In solar-locked coordinates, the rms deviation of normalized UV brightness is higher at 45-deg latitudes than in equatorial regions. 37 references.

  20. Cloud Computing og availability

    E-print Network

    Christensen, Henrik Bærbak

    Cloud Computing og availability Projekt i pålidelighed Henrik Lavdal - 20010210 Søren Bardino Kaa - 20011654 Gruppe 8 19-03-2010 #12;Cloud Computing og availability Side 2 af 28 Indholdsfortegnelse ...........................................................................................5 Cloud computing

  1. Ad hoc cloud computing 

    E-print Network

    McGilvary, Gary Andrew

    2014-11-27

    Commercial and private cloud providers offer virtualized resources via a set of co-located and dedicated hosts that are exclusively reserved for the purpose of offering a cloud service. While both cloud models appeal to ...

  2. Liftable Vector Kevin Houston

    E-print Network

    Houston, Kevin

    Liftable Vector Fields Kevin Houston Motivation Liftable Vector Fields Minimal Cross-cap The Three Families Applications Shameless Plug Vector Fields Liftable Over Stable Maps Kevin Houston Joint on Singularities in Generic Geometry and Applications, Valencia, Spain 2009 #12;Liftable Vector Fields Kevin

  3. Present-day plate motions

    NASA Technical Reports Server (NTRS)

    Minster, J. B.; Jordan, T. H.

    1977-01-01

    A data set comprising 110 spreading rates, 78 transform fault azimuths and 142 earthquake slip vectors was inverted to yield a new instantaneous plate motion model, designated RM2. The mean averaging interval for the relative motion data was reduced to less than 3 My. A detailed comparison of RM2 with angular velocity vectors which best fit the data along individual plate boundaries indicates that RM2 performs close to optimally in most regions, with several notable exceptions. On the other hand, a previous estimate (RM1) failed to satisfy an extensive set of new data collected in the South Atlantic Ocean. It is shown that RM1 incorrectly predicts the plate kinematics in the South Atlantic because the presently available data are inconsistent with the plate geometry assumed in deriving RM1. It is demonstrated that this inconsistency can be remedied by postulating the existence of internal deformation with the Indian plate, although alternate explanations are possible.

  4. Chapter 1 Brownian motion c # Brownian motion

    E-print Network

    Zhang, Li-Xin

    Chapter 1 Brownian motion c Üá# Brownian motion and stochastic calculus #12;Chapter 1 Brownian Brownian motion c Üá# Chapter 1. Brownian motion #12;Chapter 1 Brownian motion c Üá# 1.1 Basic concepts, xt = x(t), t 0. #12;Chapter 1 Brownian motion c Üá# 1.1 Basic concepts on stochastic processes

  5. Types of Clouds

    NSDL National Science Digital Library

    Duane Friend

    This is a basic lesson on clouds. Very nice photos of cumulus and cumulonimbus clouds are presented on the page as well as a description of all major cloud types and their associated weather. Two activities are presented. One invites the learner to create a cloud, while the other involves creating a collage of cloud images along with information about the weather associated with each cloud type.

  6. Classification of storms based on their boundaries and cloud top temperatures using satellite imagery

    Microsoft Academic Search

    Baolie Cheng; J. Fernando Vega-Riveros; Kamal Jabbour; Walter Meyer

    1989-01-01

    A system for interpreting and classifying severe weather patterns is presented. The system uses several image-processing and pattern-recognition techniques to detect storms in satellite cloud cover imagery. It performs several basic satellite image-interpretation tasks, i.e. cloud boundary detection, cloud top temperature and height estimation, cloud systems motion analysis, and storm classification. Some preliminary results on actual satellite images are presented

  7. Influence of aircraft vortices on spray cloud behavior.

    PubMed

    Mickle, R E

    1996-06-01

    For small droplet spraying, the spray cloud is initially entrained into the wingtip vortices so that the ultimate fate of the spray is controlled by the motion of these vortices. In close to 100 aerial sprays, the emitted spray cloud has been mapped using a scanning laser system that displays diffusion and transport of the spray cloud. Results detailing the concentrations within the spray cloud in space and time are given for sprays in parallel and crosswinds. Wind direction is seen to potentially alter the vortex motion and hence the fate of the spray cloud. In crosswind spraying, the vortex behavior associated with the 2 wings is found to differ, which leads to enhanced deposition from the upwind wing and enhanced drift from the downwind wing. PMID:8827623

  8. Bad Clouds

    NSDL National Science Digital Library

    Alistair Fraser

    This information is designed to belie the misconception that the capacity of air to hold water vapor is temperature dependent and that air can become saturated with water vapor. The temperature of a cloud droplet or ice crystal will be nearly the same as that of the air, so people imagine that somehow the air was to blame. But, if the other gases of the air were removed, leaving everything else the same, condensation and evaporation would proceed as before and the air was irrelevant to the behavior of the water molecules. It is therefore not correct to assign the behavior of water to an invented holding capacity of the air.

  9. Digital image stabilization with sub-image phase correlation based global motion estimation

    Microsoft Academic Search

    S. Erturk

    2003-01-01

    This paper presents digital image stabilization with sub-image phase correlation based global motion estimation and Kalman filtering based motion correction. Global motion is estimated from the local motions of four sub-images each of which is detected using phase correlation based motion estimation. The global motion vector is decided according to the peak values of sub-image phase correlation surfaces, instead of

  10. Vectorization of Monte Carlo particle transport

    SciTech Connect

    Burns, P.J.; Christon, M.; Schweitzer, R.; Lubeck, O.M.; Wasserman, H.J.; Simmons, M.L.; Pryor, D.V. (Colorado State Univ., Fort Collins, CO (USA). Computer Center; Los Alamos National Lab., NM (USA); Supercomputing Research Center, Bowie, MD (USA))

    1989-01-01

    Fully vectorized versions of the Los Alamos National Laboratory benchmark code Gamteb, a Monte Carlo photon transport algorithm, were developed for the Cyber 205/ETA-10 and Cray X-MP/Y-MP architectures. Single-processor performance measurements of the vector and scalar implementations were modeled in a modified Amdahl's Law that accounts for additional data motion in the vector code. The performance and implementation strategy of the vector codes are related to architectural features of each machine. Speedups between fifteen and eighteen for Cyber 205/ETA-10 architectures, and about nine for CRAY X-MP/Y-MP architectures are observed. The best single processor execution time for the problem was 0.33 seconds on the ETA-10G, and 0.42 seconds on the CRAY Y-MP. 32 refs., 12 figs., 1 tab.

  11. Reading the Clouds: CloudSat Poster

    NSDL National Science Digital Library

    This poster illustrates and describes types of high-, low-, and mid-altitude clouds. Poster back has article and activity related to Earth's water cycle, as well as a cloud identification quiz and a water cycle crossword puzzle.

  12. PhET Teacher Activities: Vectors Simulations Lab

    NSDL National Science Digital Library

    2013-02-05

    This virtual lab was developed by a high school teacher specifically for use with the PhET simulation "Motion in 2D". It provides explicit direction for using the simulation to explore vector quantities, vector addition, and calculating resultants. In the last half of the activity, students demonstrate understanding by performing specific calculations, then using the simulation to check their work. The lesson includes printable student data tables. The associated simulation (which must be running to complete this activity) is available from PhET at: motion-2d" target="_blank">Motion in 2D. Editor's Note: This lesson provides guided instruction to help students stay on task as they explore vector quantities with the simulation. It then takes the learner to the next level: can they apply what they learned to perform the calculations to find vector resultants?

  13. Dynamics of Exozodiacal Clouds

    E-print Network

    M. Kuchner; C. Stark; O. Absil; J. -C. Augereau; P. Thebault

    2007-07-09

    The inner Solar System contains a cloud of small (1-100 micron) dust grains created when small bodies-asteroids, comets, and Kuiper belt objects-collide and outgas. This dust cloud, the zodiacal cloud probably has extrasolar analogs, exozodiacal clouds. Exozodiacal clouds are related to debris disks, clouds of rocks and dust orbiting main sequence stars thought to represent the debris left over from planet formation. Some debris disks appear to contain distinct inner clouds that could be considered massive exozodiacal clouds (e.g. Koerner et al. 1998, Absil et al. 2006). This white paper addresses the need for future theoretical work on the dynamics of exozodiacal clouds. This theoretical work should help us discover new planets and understand exozodiacal clouds as astrophysical noise. So far, observations of nearby stars have not provided good constraints on the structures of exozodiacal clouds. But future observations probably will demand a better theoretical understanding of these systems.

  14. A cloud line over the Gulf Stream

    NASA Astrophysics Data System (ADS)

    Li, Xiaofeng; Zheng, Weizhong; Pichel, William G.; Zou, Cheng-Zhi; Clemente-Colón, Pablo; Friedman, Karen S.

    2004-07-01

    A 1000 km long cloud-line over the major axis of the Gulf Stream was detected in imagery from a number of satellites on April 24, 2001. Analysis of environmental conditions shows that such a cloud-line is formed when the synoptic low-level wind is parallel to the Gulf Stream axis and the sky is clear, conditions that rarely occur in the high-temperature and high-moisture Gulf Stream region. The PSU-NCAR fifth-generation Mesoscale Model (MM5) is used to study the cloud line. Results show that upward motion of the air in the middle of the Gulf Stream, caused by mesoscale solenoidal circulation induced by the large surface thermal gradient, is the source for the large cloud-line formation. This cloud-line formation mechanism is different from that of commonly observed ship cloud lines induced by ship-stack emissions, and its extent is much longer than that of cloud lines induced by lake effects.

  15. The motion and active deformation of India

    Microsoft Academic Search

    J. Paul; R. Bürgmann; V. K. Gaur; R. Bilham; K. M. Larson; M. B. Ananda; S. Jade; M. Mukal; T. S. Anupama; G. Satyal; D. Kumar

    2001-01-01

    Measurements of surface displacements using GPS constrain the motion and deformation of India and India-Eurasia plate boundary deformation along the Himalaya. The GPS velocities of plate-interior sites constrain the pole of the angular velocity vector of India with respect to Eurasia to lie at 25.6+\\/-1.0°N11.1+\\/-9.0°E, approximately 6° west of the NUVEL-1A pole of <3 Ma plate motion. The angular rotation

  16. Spring Motion

    NSDL National Science Digital Library

    Moore, Lang

    Created by Lang Moore and David Smith for the Connected Curriculum Project, the purposes of this module are to investigate a mathematical model for spring motion and to study the effect of increased damping. This is one within a much larger set of learning modules hosted by Duke University.

  17. Solar angles revisited using a general vector approach

    SciTech Connect

    Parkin, Robert E. [Department of Mechanical Engineering, University of Massachusetts, 1 University Avenue, Lowell, MA 01854 (United States)

    2010-06-15

    Rather than follow the standard technique using direction cosines or major axes vectors to define the angles of the sun, we develop the necessary formulae from a 3-tuple vector based analysis. The direction of the sun with respect to a Cartesian coordinate system is defined as a unit vector, as is the orthogonal to a surface intended to accept solar radiation. The vector formulation is powerful and universal. More importantly, the diagrams used to describe the relative motion of the sun with respect to the Earth are quite simple, leading to less confusion when translating the geometry to algebra. An interesting result on the change in solar angle with time follows. (author)

  18. Cloud Computing hosting

    Microsoft Academic Search

    Lixin Fu; C. Gondi

    2010-01-01

    Cloud Computing is a paradigm in which data, applications or software are accessed over a network. This network of servers is called as “Cloud”. Using a client such as desktops, entertainment centers, tablet computers, notebooks, wall computers, handhelds etc, users can reach into the cloud for resources as they need them. Cloud computing is on-demand access to virtualized IT resources

  19. Planning cloud seeding research

    Microsoft Academic Search

    F. H. Ludlam

    1955-01-01

    It is suggested that a theory of cloud seeding needs to be developed before seeding experiments can be properly planned and assessed. This theory will arise from improved knowledge of cloud processes gained by the study of natural clouds. Some techniques used in observing shower clouds in Sweden are described, and some preliminary results mentioned.

  20. Visual simulation of clouds

    Microsoft Academic Search

    Geoffrey Y. Gardner

    1985-01-01

    Clouds present serious problems to standard computer image generation techniques because clouds do not have well-defined surfaces and boundaries. In addition, clouds contain varying degrees of translucence, and their amorphous structure can change with time. Although several approaches to cloud simulation have produced impressive results, they have relied on complex mathematical models which produce high computation costs for a single

  1. Stratocumulus Clouds ROBERT WOOD

    E-print Network

    Wood, Robert

    REVIEW Stratocumulus Clouds ROBERT WOOD University of Washington, Seattle, Washington (Manuscript of the climatological, structural, and organizational aspects of stratocumulus clouds and the physical processes controlling them. More of Earth's surface is covered by stratocumulus clouds than by any other cloud type

  2. Cloud Computing For Bioinformatics

    E-print Network

    Ferrara, Katherine W.

    Cloud Computing For Bioinformatics EC2 and AMIs #12;Quick-starting an EC2 instance (let's get our feet wet!) Cloud Computing #12;Cloud Computing: EC2 instance Quick Start · On EC2 console, we can click on Launch Instance · This will let us get up and going quickly #12;Cloud Computing: EC2 instance

  3. The Cloud Appreciation Society

    NSDL National Science Digital Library

    The Cloud Appreciation Society believes that "clouds are Nature's poetry" and, therefore, "pledges to fight 'blue-sky thinking'." Visitors can find out about the latest cloud related news and events. The website offers a forum for users to ask cloud-related questions and communicate with other cloud enthusiasts. Anyone in the UK can join the society for free and membership will soon be expanding to other areas of the world. Everyone should check out the numerous fascinating pictures in the cloud gallery. Individuals can also contribute their cloud photographs to the continually growing collection. This site is also reviewed in the March 4, 2005_NSDL Physical Sciences Report_.

  4. Vector coherent states for nanoparticle Hamiltonians

    E-print Network

    Isiaka Aremua; Mahouton Norbert Hounkonnou

    2011-10-01

    The first part of this work deals with a formalism of vector coherent states construction for a system of $M$ Fermi-type modes associated with $N$ bosonic modes. Then follows a generalization to a Hamiltonian describing the translational motion of the center of mass of a nanoparticle. The latter gives rise to a new mechanism for the electronic energy relaxation in nanocrystals, intensively studied today in condensed matter physics. Finite degeneracies of the involved Hamiltonian systems are also investigated. The defined vector coherent states satisfy relevant mathematical properties of continuity, resolution of identity, temporal stability and action identity.

  5. Teaching Universal Gravitation with Vector Games

    NASA Astrophysics Data System (ADS)

    Lowry, Matthew

    2008-12-01

    Like many high school and college physics teachers, I have found playing vector games to be a useful way of illustrating the concepts of inertia, velocity, and acceleration. Like many, I have also had difficulty in trying to get students to understand Newton's law of universal gravitation, specifically the inverse-square law and its application to motion. In this paper, I'll outline a way to address this problem through use of a vector game. The inspiration for this idea came from a January 1998 article in The Physics Teacher by Michael Vinson entitled "Space Race: A Game of Physics Adventure."

  6. Elementary GLOBE: Cloud Fun

    NSDL National Science Digital Library

    2008-12-01

    A learning activity for the "Do You Know That Clouds Have Names?" book in the Elementary GLOBE series. Each student will be given the opportunity to create their own cumulus cloud out of white paper and mount it on blue paper. Students will also complete the Cloud Fun Student Activity Sheet that includes a description of the cloud and what the weather was like on the day the cloud was observed. The purpose of the activity is to help students identify cumulus clouds and observe the weather conditions on days that they see cumulus clouds. Students will learn about a cumulus cloud's shape and appearance, how to verbally describe cumulus clouds, and what the weather is generally like when these clouds appear in the sky.

  7. Orion Outlying Clouds

    E-print Network

    Juan M. Alcalá; Elvira Covino; Silvio Leccia

    2008-09-03

    In this chapter we review the properties of the Orion outlying clouds at b clouds are located far off the Orion giant molecular cloud complex and are in most cases small cometary-shaped clouds, with their head pointing back towards the main Orion clouds. A wealth of data indicate that star formation is ongoing in many of these clouds. The star formation in these regions might have been triggered due to the strong impact of the massive stars in the Orion OB association. Some of the clouds discussed here may be part of the Orion-Eridanus bubble. An overview on each individual cloud is given. A synthesis of the Pre-Main Sequence stars discovered in these clouds is presented. We also discuss the millimeter and centimeter data and present a review of the outflows and Herbig-Haro objects so far discovered in these clouds.

  8. Malaria Vector Species

    NSDL National Science Digital Library

    0000-00-00

    A sub-page of the extremely informative VectorBase. This is a worldwide listing of malaria vectors divided into 12 geographic regions following the 1957 classic The Epidemiology and Control of Malaria by MacDonald.

  9. CERES CLoud Effects

    NSDL National Science Digital Library

    1997-06-06

    This computer-generated animation depicts the Clouds and the Earth's Radiant Energy System (CERES) instrument in operation. CERES measures the energy at the top of the atmosphere and estimates energy levels in the atmosphere and at the Earth's surface. Using information from very high resolution cloud-imaging instruments on the same spacecraft, CERES also will determine cloud properties, including cloud amount, altitude, thickness, and the size of the cloud particles.

  10. IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 40, NO. 2, FEBRUARY 2002 405 Cloud Tracking by Scale Space Classification

    E-print Network

    Acton, Scott

    Abstract--The problem of cloud tracking within a sequence of geo-stationary satellite images has direct in a sequence of geosta- tionary satellite images. Cloud tracking is an example of motion analysis of deIEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 40, NO. 2, FEBRUARY 2002 405 Cloud

  11. Sequential Vector Packing

    Microsoft Academic Search

    Mark Cieliebak; Alexander Hall; Riko Jacob; Marc Nunkesser

    2007-01-01

    We introduce a novel variant of the well known d-dimensional bin (or vector) packing problem. Given a sequence of non-negative d-dimensional vectors, the goal is to pack these into as few bins as possible. In the classical problem the bin size vector is given and the sequence can be partitioned arbi- trarily. We study a variation where the vectors have

  12. Vector median filters

    Microsoft Academic Search

    J. Astola; P. Haavisto; Y. Neuvo

    1990-01-01

    Two nonlinear algorithms for processing vector-valued signals are introduced. The algorithms, called vector median operations, are derived from two multidimensional probability density functions using the maximum-likelihood-estimate approach. The underlying probability densities are exponential, and the resulting operations have properties very similar to those of the median filter. In the vector median approach, the samples of the vector-valued input signal are

  13. Diffuse Reflection of Laser Light From Clouds

    NASA Technical Reports Server (NTRS)

    Cahalan, R. F.; Davis, A.; McGill, M.

    1999-01-01

    Laser light reflected from an aqueous suspension of particles or "cloud" with known thickness and particle size distribution defines the "cloud radiative Green's function", G. G is sensitive to cloud thickness, allowing retrieval of that important quantity. We describe a laboratory simulation of G, useful in design of an offbeam Lidar instrument for remote sensing of cloud thickness. Clouds of polystyrene microspheres suspended in water are analogous to real clouds of water droplets suspended in air. The size distribution extends from 0.5 microns to 25 microns, roughly lognormal, similar to real clouds. Density of suspended spheres is adjusted so photon mean-free-path is about 10 cm, 1000 times smaller than in real clouds. The light source is a Nd:YAG laser at 530 nm. Detectors are flux and photon-counting PMTs, with a glass probe for precise positioning. A Labview 5 VI controls position and data acquisition, via an NI Motion Control board connected to a stepper motor driving an Edmund linear slider,and a 16-channel 16-bit NI-DAQ board. The stepper motor is accurate to 10 microns. Step size is selectable. Far from the beam, the rate of exponential increase in the beam direction scales as expected from diffusion theory, linearly with cloud thickness, and inversely as the square root of the reduced optical thickness, independent of particle size. Nearer the beam the signal increases faster than exponential and depends on particle size. Results verify 3D Monte Carlo simulations that demonstrate detectability of remotely sensed offbeam returns, without filters at night, with narrow bandpass filter in day.

  14. The Advancement of Intraplate Tectonic Motion Detection by the Use of Atmospherically Corrected InSAR Time-series and its Decomposition into a 3D Field Vector in South-East Sicily, Italy.

    NASA Astrophysics Data System (ADS)

    Vollrath, A.; Bekaert, D. P.; Bonforte, A.; Guglielmino, F.; Hooper, A. J.; Stramondo, S.; Zucca, F.

    2014-12-01

    This study provides insights into the advancements gained by applying a tropospheric correction to a time-series InSAR small baseline network processed using the StaMPS software for the Hyblean Plateau in south-east Sicily, Italy. The contribution of the atmosphere is one of the major error sources in repeat-pass InSAR in general. For time-series analysis spatial and temporal filtering of the interferometric phase can be used to address atmospheric signals. This however might be at the cost of smoothing and removal of the tectonic deformation . We applied a tropospheric correction to each interferogram based on estimates of the ERA-Interim weather model, provided by the European Center for Medium-Range Weather Forecast (ECMWF). This approach is part of the InSAR Atmospheric Correction Toolbox (Bekaert et al, in prep) and converts the tropospheric water vapor content into the phase-delay of the radar line-of-sight. For the analysis we used 49 descending and 58 ascending Envisat SAR images, which cover the time period from 2003 until 2010. In addition, we have processed 30 SAR images of RADARSAT-2 for the period between 2010-2012. Furthermore, we used the different viewing geometries and the integration of GPS data to decompose the single line-of-sight velocities into a 3-dimensional field vector by applying the SISTEM approach (Guglielmino et al. 2011). First results reveal that the atmospherically corrected data retain the deformation signal along geological structures like the Scicli-Ragusa fault whilst the standard filtering approach is canceling out these very slow deformation patterns. Simultaneously, the variability of the signal in space is diminished and thus gives more confidence on the deformation patterns observed by the SAR. Consequently, the decomposition of the line-of-sight velocities and the integration with the GPS data allows us to retrieve a more realistic deformation field.

  15. MotionExplorer: exploratory search in human motion capture data based on hierarchical aggregation.

    PubMed

    Bernard, Jürgen; Wilhelm, Nils; Krüger, Björn; May, Thorsten; Schreck, Tobias; Kohlhammer, Jörn

    2013-12-01

    We present MotionExplorer, an exploratory search and analysis system for sequences of human motion in large motion capture data collections. This special type of multivariate time series data is relevant in many research fields including medicine, sports and animation. Key tasks in working with motion data include analysis of motion states and transitions, and synthesis of motion vectors by interpolation and combination. In the practice of research and application of human motion data, challenges exist in providing visual summaries and drill-down functionality for handling large motion data collections. We find that this domain can benefit from appropriate visual retrieval and analysis support to handle these tasks in presence of large motion data. To address this need, we developed MotionExplorer together with domain experts as an exploratory search system based on interactive aggregation and visualization of motion states as a basis for data navigation, exploration, and search. Based on an overview-first type visualization, users are able to search for interesting sub-sequences of motion based on a query-by-example metaphor, and explore search results by details on demand. We developed MotionExplorer in close collaboration with the targeted users who are researchers working on human motion synthesis and analysis, including a summative field study. Additionally, we conducted a laboratory design study to substantially improve MotionExplorer towards an intuitive, usable and robust design. MotionExplorer enables the search in human motion capture data with only a few mouse clicks. The researchers unanimously confirm that the system can efficiently support their work. PMID:24051792

  16. Quantication and analysis of respiratory motion from 4D MRI

    NASA Astrophysics Data System (ADS)

    Aizzuddin Abd Rahni, Ashrani; Lewis, Emma; Wells, Kevin

    2014-11-01

    It is well known that respiratory motion affects image acquisition and also external beam radiotherapy (EBRT) treatment planning and delivery. However often the existing approaches for respiratory motion management are based on a generic view of respiratory motion such as the general movement of organ, tissue or fiducials. This paper thus aims to present a more in depth analysis of respiratory motion based on 4D MRI for further integration into motion correction in image acquisition or image based EBRT. Internal and external motion was first analysed separately, on a per-organ basis for internal motion. Principal component analysis (PCA) was then performed on the internal and external motion vectors separately and the relationship between the two PCA spaces was analysed. The motion extracted from 4D MRI on general was found to be consistent with what has been reported in literature.

  17. Spacetime vector analysis

    Microsoft Academic Search

    G. Sobczyk

    1981-01-01

    Ordinary Gibbs-Heaviside vector algebra is complexified to apply to spacetime. The resulting algebra is isomorphic to both the Pauli algebra, and to the algebra of complex quaternions. Each inertial system is distinguished by a rest frame of real vectors. The rudiments of a spacetime vector analysis are given.

  18. Balancing sets of vectors

    Microsoft Academic Search

    Noga Alon; E. E. Bergmann; Don Coppersmith; Andrew M. Odlyzko

    1988-01-01

    IntroductionLet K(n , d) denote the minimal k for which there exist 1 vectors v 1 , . . . , v k oflength n such that for any 1 vector w of length n, there is an i, 1 i k, such thatv i.w d, where v.w denotes the usual inner product of two vectors. Sincev.w n (mod 2)

  19. Projectile Motion

    NSDL National Science Digital Library

    2014-09-18

    Students are introduced to the concept of projectile motion, of which they are often familiar from life experiences,such as playing sports such as basketball or baseball, even though they may not understand the physics involved. Students use tabletop-sized robots to build projectile throwers and measure motion using sensors. They compute distances and velocities using simple kinematic equations and confirm their results through measurements by hand. To apply the concept, students calculate the necessary speed of an object to reach a certain distance in a hypothetical scenaro: A group of hikers stranded at the bottom of a cliff need food, but rescuers cannot deliver it themselves, so they must devise a way to get the food to the hikers.

  20. Kepler Motion

    NSDL National Science Digital Library

    Fu-Kwun Hwang

    2004-10-27

    This java applet displays Kepler's three laws of planetary motion in action. Users can select which of the three laws they wish to be animated and alter the initial conditions, observing how orbital paths and velocities change. Kepler derived his three laws after years of study on data that he inherited from his mentor, Tycho Brahe. Instructions on how to use the animation are provided, and a list of links to other related sites is included.

  1. Taiwan UniCloud: A Cloud Testbed with Collaborative Cloud Services Wu-Chun Chung*

    E-print Network

    Chung, Yeh-Ching

    }@cs.nthu.edu.tw Abstract--This paper introduces a prototype of Taiwan UniCloud, a community-driven hybrid cloud platform sotrage; portal I. INTRODUCTION Cloud computing is an emerging topic recently. The core concept of cloudTaiwan UniCloud: A Cloud Testbed with Collaborative Cloud Services Wu-Chun Chung* , Po-Chi Shih

  2. THE EVOLUTION OF GAS CLOUDS FALLING IN THE MAGNETIZED GALACTIC HALO: HIGH-VELOCITY CLOUDS (HVCs) ORIGINATED IN THE GALACTIC FOUNTAIN

    SciTech Connect

    Kwak, Kyujin; Shelton, Robin L.; Raley, Elizabeth A. [Department of Physics and Astronomy, University of Georgia, Athens, GA 30602 (United States)

    2009-07-10

    In the Galactic fountain scenario, supernovae and/or stellar winds propel material into the Galactic halo. As the material cools, it condenses into clouds. By using FLASH three-dimensional magnetohydrodynamic simulations, we model and study the dynamical evolution of these gas clouds after they form and begin to fall toward the Galactic plane. In our simulations, we assume that the gas clouds form at a height of z = 5 kpc above the Galactic midplane, then begin to fall from rest. We investigate how the cloud's evolution, dynamics, and interaction with the interstellar medium (ISM) are affected by the initial mass of the cloud. We find that clouds with sufficiently large initial densities (n {>=} 0.1 H atoms cm{sup -3}) accelerate sufficiently and maintain sufficiently large column densities as to be observed and identified as high-velocity clouds (HVCs) even if the ISM is weakly magnetized (1.3 {mu}G). However, the ISM can provide noticeable resistance to the motion of a low-density cloud (n {<=} 0.01 H atoms cm{sup -3}) thus making it more probable that a low-density cloud will attain the speed of an intermediate-velocity cloud rather than the speed of an HVC. We also investigate the effects of various possible magnetic field configurations. As expected, the ISM's resistance is greatest when the magnetic field is strong and perpendicular to the motion of the cloud. The trajectory of the cloud is guided by the magnetic field lines in cases where the magnetic field is oriented diagonal to the Galactic plane. The model cloud simulations show that the interactions between the cloud and the ISM can be understood via analogy to the shock tube problem which involves shock and rarefaction waves. We also discuss accelerated ambient gas, streamers of material ablated from the clouds, and the cloud's evolution from a sphere-shaped to a disk- or cigar-shaped object.

  3. Photonic Equations of Motion

    SciTech Connect

    Ritchie, A B; Crenshaw, M E

    2004-09-17

    Although the concept of the photon as a quantum particle is sharpened by the quantization of the energy of the classical radiation field in a cavity, the photon's spin has remained a classical degree of freedom. The photon is considered a spin-1 particle, although only two classical polarization states transverse to its direction of propagation are allowed. Effectively therefore the photon is a spin-1/2 particle, although it still obeys Bose-Einstein statistics because the photon-photon interaction is zero. Here they show that the two polarization states of the photon can be quantized using Pauli's spin vector, such that a suitable equation of motion for the photon is Dirac's relativistic wave equation for zero mass and zero charge. Maxwell's equations for a free photon are inferred from the Dirac-field formalism and thus provide proof of this claim. For photons in the presence of electronic sources for electromagnetic fields we posit Lorentz-invariant inhomogeneous photonic equations of motion. Electro-dynamic operator equations are inferred from this modified Dirac-field formalism which reduce to Maxwell's equations if spin-dependent terms in the radiation-matter interaction are dropped.

  4. A Low Dimensional Fluid Motion Estimator

    Microsoft Academic Search

    Anne Cuzol; Pierre Hellier; Étienne Mémin

    2007-01-01

    In this paper we propose a new motion estimator for image sequences depicting fluid flows. The proposed estimator is based on the Helmholtz decomposition of vector fields. This decomposition consists in representing the velocity field as a sum of a divergence free component and a vorticity free component. The objective is to provide a low-dimensional parametric representation of optical flows

  5. Motion and force control of robot manipulators

    Microsoft Academic Search

    Oussama Khatib; Joel Burdick

    1986-01-01

    In this paper we present a unified approach for the control of manipulator motions and active forces based on the operational space formulation. The end-effector dynamic model is used in the development of a control system in which the generalized operational space end-effector forces are selected as the command vector. This formulation provides a framework for natural and efficient integration

  6. Image interpolation with edge-preserving differential motion refinement

    Microsoft Academic Search

    Marco Cagnazzo; Wided Miled; Thomas Maugey; Béatrice Pesquet-Popescu

    2009-01-01

    Motion estimation (ME) methods based on differential techniques provide useful information for video analysis, and moreover it is relatively easy to embed into them regularity constraints enforcing for example, contour preservation. On the other hand, these techniques are rarely employed for video compression since, though accurate, the dense motion vector field (MVF) they produce requires too much coding resource and

  7. Motion-Adaptive Transforms based on Vertex-Weighted Graphs

    E-print Network

    Flierl, Markus

    Motion-Adaptive Transforms based on Vertex-Weighted Graphs Du Liu and Markus Flierl KTH Royal in image sequences connects pixels that are highly correlated. In this paper, we consider vertex-weighted graphs that are formed by motion vector information. The vertex weights are defined by scale factors

  8. IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY, VOL. X, NO. Y, MONTH 2005 1 Motion-compensated temporal filtering and motion

    E-print Network

    Woods, John W.

    -directional traingular mesh based motion estimates to achieve 3-D wavelet transform using lifting approach. Their work coding gain and significant PSNR improvement at high bit rates, a necessary doubling of the number or the temporal level. Index Terms-- Subband/wavelet coding, motion estima- tion, motion vector coding, lifting

  9. Fractal Structure of Molecular Clouds

    E-print Network

    Srabani Datta

    2001-05-02

    Compelling evidence exists to show that the structure of molecular clouds is fractal in nature. In this paper, the author reiterates this view and, in addition, asserts that not only is cloud geometry fractal, but that they also have a common characteristic - they are similar in shape to the Horsehead nebula in Orion. This shape can be described by the Julia function f(x)= z^2 + c,where both z and c are complex quantities and c = -0.745429 + 0.113008i. The dynamical processes responsible for the production of these clouds seem to be turbulence followed by Brownian motion till high densities are reached, at which point structure formation is dictated by gravity. The author presents image analysis of four varied examples, namely those of the Horsehead nebula, Eagle nebula, Rosette nebula and Paley I nebula to prove her hypothesis. The images of these nebulae are analyzed for their box dimension using fractal analysis software and comparisons are made with the given Julia set.

  10. Rotating Motion

    NSDL National Science Digital Library

    Wolfgang Christian

    In these problems, two people ride on a merry-go-round (radius fixed at 10 m..it's big!). One rider tosses a ball toward the other. The period of motion can be varied as can the initial velocity of the ball, relative to rider. One of the problems is to select the initial velocity of the ball so that it passes through center of the merry-go-round. Another is for the rider who throws the ball to catch it him/herself after exactly half a rotation.

  11. Dual-FOV Raman and Doppler lidar studies of aerosol-cloud interactions: Simultaneous profiling of aerosols, warm-cloud properties, and vertical wind

    NASA Astrophysics Data System (ADS)

    Schmidt, Jörg; Ansmann, Albert; Bühl, Johannes; Baars, Holger; Wandinger, Ulla; Müller, Detlef; Malinka, Aleksey V.

    2014-05-01

    For the first time, colocated dual-field of view (dual-FOV) Raman lidar and Doppler lidar observations (case studies) of aerosol and cloud optical and microphysical properties below and within thin layered liquid water clouds are presented together with an updraft and downdraft characterization at cloud base. The goal of this work is to investigate the relationship between aerosol load close to cloud base and cloud characteristics of warm (purely liquid) clouds and the study of the influence of vertical motions and turbulent mixing on this relationship. We further use this opportunity to illustrate the applicability of the novel dual-FOV Raman lidar in this field of research. The dual-FOV lidar combines the well-established multiwavelength Raman lidar technique for aerosol retrievals and the multiple-scattering Raman lidar technique for profiling of the single-scattering extinction coefficient, effective radius, number concentration of the cloud droplets, and liquid water content. Key findings of our 3 year observations are presented in several case studies of optically thin altocumulus layers occurring in the lower free troposphere between 2.5 and 4 km height over Leipzig, Germany, during clean and polluted situations. For the clouds that we observed, the most direct link between aerosol proxy (particle extinction coefficient) and cloud proxy (cloud droplet number concentration) was found at cloud base during updraft periods. Above cloud base, additional processes resulting from turbulent mixing and entrainment of dry air make it difficult to determine the direct impact of aerosols on cloud processes.

  12. A low complexity halo reduction method for motion compensated frame interpolation

    NASA Astrophysics Data System (ADS)

    Han, Rui; Men, Aidong; Gu, Jianping

    2013-03-01

    This paper proposed a low complexity halo reduction method for motion compensated frame interpolation which bases on only two successive frames. An improved forward and backward jointing motion estimation method that features a faster convergence speed is utilized to produce the motion vector fields of the original frames. These motion vector fields are retimed to the to-be-interpolated frame to calculate the motion vector field for interpolation and to get the coarse location of the new exposed areas. Through analyzing the relationship of the adjacent motion vectors, two general equations are generated for the covered and uncovered blocks, and occlusion areas are further refined. Finally, unidirectional interpolation and bi-directional interpolation are combined to avoid the halos and block artifacts. Experimental results show that the proposed algorithm achieves much better image quality than that without halo reduction processing.

  13. The Essential Visibility Graph: An Approach to Global Motion Planning for Autonomous Mobile Robots

    Microsoft Academic Search

    Jason A. Janét; Ren C. Luo; Michael G. Kay

    1995-01-01

    An approach to global motion planning for autonomous mobile robots has been developed on the basis of traversability vectors (t-vectors). Through the overall course of this research it was found that t-vectors provide a utility, efficiency and mathematical stability for collision detection and visibility that cannot be matched by commonly used algebraic approaches in static and dynamic environments. This paper

  14. Thermal diffusion cloud chamber-new criteria for proper operation

    Microsoft Academic Search

    Richard H. Heist; Daniel Martinez; Yuk Chan; Anne Bertelsmann

    2000-01-01

    We report results of new nucleation experiments involving 1-pentanol with hydrogen as the background gas utilizing the high-pressure diffusion cloud chamber (HPCC). We discuss the important issue of buoyancy-driven convective motion and cloud chamber operation, and we focus on the lower total pressure limit required for stable chamber operation. We provide, for the first time, an empirical procedure for determining

  15. Index Sets and Vectorization

    SciTech Connect

    Keasler, J A

    2012-03-27

    Vectorization is data parallelism (SIMD, SIMT, etc.) - extension of ISA enabling the same instruction to be performed on multiple data items simultaeously. Many/most CPUs support vectorization in some form. Vectorization is difficult to enable, but can yield large efficiency gains. Extra programmer effort is required because: (1) not all algorithms can be vectorized (regular algorithm structure and fine-grain parallelism must be used); (2) most CPUs have data alignment restrictions for load/store operations (obey or risk incorrect code); (3) special directives are often needed to enable vectorization; and (4) vector instructions are architecture-specific. Vectorization is the best way to optimize for power and performance due to reduced clock cycles. When data is organized properly, a vector load instruction (i.e. movaps) can replace 'normal' load instructions (i.e. movsd). Vector operations can potentially have a smaller footprint in the instruction cache when fewer instructions need to be executed. Hybrid index sets insulate users from architecture specific details. We have applied hybrid index sets to achieve optimal vectorization. We can extend this concept to handle other programming models.

  16. Motion Information Inferring Scheme for Multi-View Video Coding

    NASA Astrophysics Data System (ADS)

    Koo, Han-Suh; Jeon, Yong-Joon; Jeon, Byeong-Moon

    This letter proposes a motion information inferring scheme for multi-view video coding motivated by the idea that the aspect of motion vector between the corresponding positions in the neighboring view pair is quite similar. The proposed method infers the motion information from the corresponding macroblock in the neighboring view after RD optimization with the existing prediction modes. This letter presents evaluation showing that the method significantly enhances the efficiency especially at high bit rates.

  17. PSC Meteorology Program Cloud Boutique

    NSDL National Science Digital Library

    Plymouth State College (PSC) provides the PSC Meteorology Program Cloud Boutique Website to "provide explanations of and access to detailed pictures of some basic cloud forms." Spectacular images and brief descriptions of high clouds (cirrus, cirrocumulus, and cirrostratus), middle clouds (altocumulus and altostratus), low clouds (cumulus, stratocumulus, stratus, and fog), multi-layer clouds (nimbostratus and cumulonimbus), and orographic clouds (lenticular and cap), among others are included. The site is an excellent general cloud reference.

  18. Six Myths on the Virial Theorem for Interstellar Clouds

    E-print Network

    Javier Ballesteros-Paredes

    2006-08-03

    It has been paid little or no attention to the implications that turbulent fragmentation has on the validity of at least six common assumptions on the Virial Theorem (VT), which are: (i) the only role of turbulent motions within a cloud is to provide support against collapse, (ii) the surface terms are negligible compared to the volumetric ones, (iii) the gravitational term is a binding source for the clouds, (iv) the sign of the second-time derivative of the moment of inertia determines whether the cloud is contracting or expanding, (v) interstellar clouds are in Virial Equilibrium (VE), and (vi) Larson's (1981) relations are the observational proof that clouds are in VE. Interstellar clouds cannot fulfill these assumptions, however, because turbulent fragmentation will induce flux of mass, moment and energy between the clouds and their environment, and will favor local collapse while may disrupt the clouds within a dynamical timescale. It is argued that, although the observational and numerical evidence suggests that interstellar clouds are not in VE, the so-called ``Virial Mass'' estimations, which actually should be called ``energy-equipartition mass'' estimations, are good order-of magnitude estimations of the actual mass of the clouds just because observational surveys will tend to detect interstellar clouds appearing to be close to energy equipartition. However, since clouds are actually out of VE, as suggested by asymmetrical line profiles, they should be transient entities. These results are compatible with observationally-based estimations for rapid star formation. , and call into question the models for the star formation efficiency based on clouds being in VE.

  19. Shape from Motion data fusion brings a greater degree of autonomy and sensor integration to intelligent systems in

    E-print Network

    signals, the motion of the force vector (the ``motion'') and the calibration matrix (the ``shape Motion Multi­axis force/torque sensor calibration ­­ the process of recovering the linear calibration93 Abstract Shape from Motion data fusion brings a greater degree of autonomy and sensor

  20. 1276 IEEE TRANSACTIONS ON IMAGE PROCESSING, VOL. 8, NO. 9, SEPTEMBER 1999 A Model of the Effect of Image Motion

    E-print Network

    Milanfar, Peyman

    properties of the apparent projected motion implied by the model, and study the case of affine motion. In particular, we will study the case of affine motion and provide some illustrative examples. To begin our evolves in time according to the spatially varying motion vector field . Also, consider its corresponding

  1. Conference on Cloud Physics, Tucson, Ariz., October 21-24, 1974, Proceedings

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Condensation and ice nucleation processes are considered, taking into account measurements of cloud nuclei and aerosol size spectra in the semiarid Southwest, the formation of sulfates and the enhancement of cloud condensation nuclei in clouds, biogenic sources of atmospheric ice nuclei, and the experimental determination of the deposition coefficient of water vapor onto ice. Other topics discussed are related to precipitation growth processes, the role of ice in cloud systems, cloud modeling, measurements in Colorado hailstorms during the national hail research experiment, cloud measurements, and measurement techniques. Attention is also given to cloud electrification, zero-gravity experiments, and the control of cloud development by larger scale motions. Individual items are announced in this issue.

  2. "Electrostructural Phase Changes" In Charged Particulate Clouds: Planetary and Astrophysical Implications

    NASA Technical Reports Server (NTRS)

    Marshall, J. R.

    1999-01-01

    There is empirical evidence that freely-suspended triboelectrostatically charged particulate clouds of dielectric materials undergo rapid conversion from (nominally) monodispersed "aerosols" to a system of well-defined grain aggregates after grain motion or fluid turbulence ceases within the cloud. In United States Microgravity Laboratory Space Shuttle experiments USML-1 and USML-2, it was found that ballistically-energized grain dispersions would rapidly convert into populations of filamentary aggregates after natural fluid (air) damping of grain motion. Unless continuously disrupted mechanically, it was impossible to maintain a non-aggregated state for the grain clouds of sand-size materials. Similarly, ground- based experiments with very fine dust-size material produced the same results: rapid, impulsive "collapse" of the dispersed grains into well-defined filamentary structures. In both ground-based and microgravity experiments, the chains or filaments were created by long-range dipole electrostatic forces and dipole-induced dielectric interactions, not by monopole interactions. Maintenance of the structures was assisted by short-range static boundary adhesion forces and van der Waals interactions. When the aggregate containers in the USML experiments were disturbed after aggregate formation, the quiescently disposed filaments would rearrange themselves into fractal bundles and tighter clusters as a result of enforced encounters with one another. The long-range dipole interactions that bring the grains together into aggregates are a product of randomly-distributed monopole charges on the grain surfaces. In computer simulations, it has been shown that when the force vectors of all the random charges (of both sign) on a grain are resolved mathematically by assuming Coulombic interaction between them, the net result is a dipole moment on individual grains, even though the grains are electrically neutral insofar as there is no predominance, on their surface, of one charge sign over another. The random charges of both sign derive from natural grain-to-grain interactions that produce triboelectrification via charge exchange every time grain surfaces make contact with one another. The conversion from a random distribution of grains (upon which there are randomly distributed charges) into an organization of electrostatically-ordered aggregates, can be regarded (within the framework of granular-material science) as an "electrical or Coulombic phase change" of the particulate cloud. It is not totally dissimilar from the more normal phase-change concept in which, for example, a gas with long free-path-molecules suddenly becomes a solid as a result of structural ordering of the molecules (notably, also the result of electronic forces, albeit at a different scale). In both the gas-to-solid case, and the aerosol-to-aggregate case, the same materials and charges are present before and after the phase change, but their arrangement now has a higher degree of order and a lower-energy configuration. An input of energy into the system is required to reverse the situation. The aggregates in the USML experiments were observed to undergo at least two phase changes as noted above. The point about phase changes, and by implication, the "electrostructural" reorganizations in particulate clouds, is the following: (a) they can occur very rapidly, almost spontaneously, above a critical cloud density, (b) in going from a higher energy state to a lower energy state, they convert to a denser system, (c) energy must be required to reverse the situation, implying that energy is released during the high-to-low energy phase change. In applying this information to natural particulate clouds, some inferences can be made (it is stressed that reference is still to dielectric materials attracted by dipole forces). There are several natural settings to which the USML observations apply, and to which the phase-change implications likewise apply. Dense clouds of triboelectrically-charged, kinetically-energized grains are

  3. Cloud Computing for radiologists

    PubMed Central

    Kharat, Amit T; Safvi, Amjad; Thind, SS; Singh, Amarjit

    2012-01-01

    Cloud computing is a concept wherein a computer grid is created using the Internet with the sole purpose of utilizing shared resources such as computer software, hardware, on a pay-per-use model. Using Cloud computing, radiology users can efficiently manage multimodality imaging units by using the latest software and hardware without paying huge upfront costs. Cloud computing systems usually work on public, private, hybrid, or community models. Using the various components of a Cloud, such as applications, client, infrastructure, storage, services, and processing power, Cloud computing can help imaging units rapidly scale and descale operations and avoid huge spending on maintenance of costly applications and storage. Cloud computing allows flexibility in imaging. It sets free radiology from the confines of a hospital and creates a virtual mobile office. The downsides to Cloud computing involve security and privacy issues which need to be addressed to ensure the success of Cloud computing in the future. PMID:23599560

  4. RISK ASSESSMENT CLOUD COMPUTING

    E-print Network

    Columbia University

    SECURITY RESEARCH PRIVACY RISK ASSESSMENT AMC DATA FISMA CLOUD COMPUTING MOBILE DEVICES OPERATIONS application hosted in the cloud · Alaska DHHS fined $1.7M ­ Portable device stolen from vehicle · Mass Eye

  5. Introduction Strict vector coloring Vector coloring Quantum coloring Further work Hedetniemi conjecture for strict vector

    E-print Network

    Severini, Simone

    Introduction Strict vector coloring Vector coloring Quantum coloring Further work Hedetniemi conjecture for strict vector chromatic number Robert Sámal (joint with C.Godsil, D.Roberson, S vector coloring Vector coloring Quantum coloring Further work Outline 1 Introduction 2 Strict vector

  6. Personal Cloud Computing Security Framework

    Microsoft Academic Search

    Sang-Ho Na; Jun-Young Park; Eui-nam Huh

    2010-01-01

    Cloud computing is an evolving term these days. It describes the advance of many existing IT technologies and separates application and information resources from the underlying infrastructure. Personal Cloud is the hybrid deployment model that is combined private cloud and public cloud. By and large, cloud orchestration does not exist today. Current cloud service is provided by web browser or

  7. Community Cloud Computing

    Microsoft Academic Search

    Alexandros Marinos; Gerard Briscoe

    2009-01-01

    Cloud Computing is rising fast, with its data centres growing at an\\u000aunprecedented rate. However, this has come with concerns over privacy,\\u000aefficiency at the expense of resilience, and environmental sustainability,\\u000abecause of the dependence on Cloud vendors such as Google, Amazon and\\u000aMicrosoft. Our response is an alternative model for the Cloud\\u000aconceptualisation, providing a paradigm for Clouds in

  8. Jovian Lightning and Moonlit Clouds

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Jovian lightning and moonlit clouds. These two images, taken 75 minutes apart, show lightning storms on the night side of Jupiter along with clouds dimly lit by moonlight from Io, Jupiter's closest moon. The images were taken in visible light and are displayed in shades of red. The images used an exposure time of about one minute, and were taken when the spacecraft was on the opposite side of Jupiter from the Earth and Sun. Bright storms are present at two latitudes in the left image, and at three latitudes in the right image. Each storm was made visible by multiple lightning strikes during the exposure. Other Galileo images were deliberately scanned from east to west in order to separate individual flashes. The images show that Jovian and terrestrial lightning storms have similar flash rates, but that Jovian lightning strikes are a few orders of magnitude brighter in visible light.

    The moonlight from Io allows the lightning storms to be correlated with visible cloud features. The latitude bands where the storms are seen seem to coincide with the 'disturbed regions' in daylight images, where short-lived chaotic motions push clouds to high altitudes, much like thunderstorms on Earth. The storms in these images are roughly one to two thousand kilometers across, while individual flashes appear hundreds of kilometer across. The lightning probably originates from the deep water cloud layer and illuminates a large region of the visible ammonia cloud layer from 100 kilometers below it.

    There are several small light and dark patches that are artifacts of data compression. North is at the top of the picture. The images span approximately 50 degrees in latitude and longitude. The lower edges of the images are aligned with the equator. The images were taken on October 5th and 6th, 1997 at a range of 6.6 million kilometers by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

  9. SGP and TWP (Manus) Ice Cloud Vertical Velocities

    DOE Data Explorer

    Kalesse, Heike

    Daily netcdf-files of ice-cloud dynamics observed at the ARM sites at SGP (Jan1997-Dec2010) and Manus (Jul1999-Dec2010). The files include variables at different time resolution (10s, 20min, 1hr). Profiles of radar reflectivity factor (dbz), Doppler velocity (vel) as well as retrieved vertical air motion (V_air) and reflectivity-weighted particle terminal fall velocity (V_ter) are given at 10s, 20min and 1hr resolution. Retrieved V_air and V_ter follow radar notation, so positive values indicate downward motion. Lower level clouds are removed, however a multi-layer flag is included.

  10. SGP and TWP (Manus) Ice Cloud Vertical Velocities

    SciTech Connect

    Kalesse, Heike

    2013-06-27

    Daily netcdf-files of ice-cloud dynamics observed at the ARM sites at SGP (Jan1997-Dec2010) and Manus (Jul1999-Dec2010). The files include variables at different time resolution (10s, 20min, 1hr). Profiles of radar reflectivity factor (dbz), Doppler velocity (vel) as well as retrieved vertical air motion (V_air) and reflectivity-weighted particle terminal fall velocity (V_ter) are given at 10s, 20min and 1hr resolution. Retrieved V_air and V_ter follow radar notation, so positive values indicate downward motion. Lower level clouds are removed, however a multi-layer flag is included.

  11. Vegetation forcing and convective motion

    SciTech Connect

    Hong, X.; Leach, M.J.; Raman, S. [North Carolina State Univ., Raleigh, NC (United States)

    1995-04-01

    A large irrigated vegetation area in a semiarid or relatively dry location is a strong surface forcing of thermal circulations. Several observational studies have found that such thermally induced mesoscale circulation may contribute to the triggering and development of convective clouds. In the western United States, extensive areas of irrigated farmland are surrounded by hot, dry surfaces, such as a steppe. Substantial gradients of sensible heating in the horizontal direction lead to a {open_quotes}farm breeze{close_quotes} circulation from the cooler agricultural area to the warmer steppes found at Boardman, Oregon. These thermally forced circulations may trigger convection by the related convergence and updraft motion under favorable atmospheric conditions. The role of vegetative covering in convective motion is investigated using a mesoscale numerical model. Two- and three-dimensional simulations are described. The effects of atmospheric stability, moisture in the lower atmosphere, moisture in the upper atmosphere, and horizontal heating scale on thermally induced clouds are studied. The horizontal scale of inhomogeneity is also studied using the two-dimensional model. Finally, a realistic vegetation distribution similar to that of the Boardman Regional Flux Experiment is used in the three-dimensional simulations.

  12. Cloud security technologies

    Microsoft Academic Search

    Igor Muttik; Chris Barton

    2009-01-01

    You may have heard a new term that started making rounds very recently – “cloud-based security”. In this paper we describe past and contemporary security technologies based on the knowledge provided from the servers in the Internet “cloud”. We discuss how cloud-based malware scanners can simbiotically coexist with traditional scanning technologies, what are the advantages and limitations of the new

  13. Cloud computing security

    Microsoft Academic Search

    Dongwan Shin; William R. Claycomb; Vincent E. Urias

    2010-01-01

    Cloud computing is a paradigm rapidly being embraced by government and industry as a solution for cost-savings, scalability, and collaboration. While a multitude of applications and services are available commercially for cloud-based solutions, research in this area has yet to fully embrace the full spectrum of potential challenges facing cloud computing. This tutorial aims to provide researchers with a fundamental

  14. Cloud security metrics

    Microsoft Academic Search

    Jennifer Bayuk

    2011-01-01

    Cloud security had not yet distinguished itself as a field separate from information assurance. Its security metrics are currently synonymous with what a security professional would refer to as a third-party or vendor security audit. Where cloud services are viewed in a systems- of-systems context, any comprehensive security validation approach should rely on the ability of a cloud service to

  15. Measuring Cloud Coverage

    NSDL National Science Digital Library

    This lesson reviews clouds and uses fractions to describe cloud coverage, demonstrating how math and science work together. By using math and science to describe clouds, the lesson provides students with several means of communication (fractions and meteorological terms) to describe a meteorological situation.

  16. Satellite Cloud Computing

    Microsoft Academic Search

    Kamen Kanev; Nikolay N. Mirenkov

    2011-01-01

    In this work we present a novel concept for satellite based cloud computing integrating virtualized information resources from satellites and from the Internet. We first discuss the role of satellites in the infrastructure of cloud computing. Second we focus on some practical aspects of cloud computing, considering different configurations for access to satellite channels. We follow with reporting on our

  17. Bad Meteorology: Bad Clouds

    NSDL National Science Digital Library

    Alistair Fraser

    This site provides an explanation for cloud formation and seeks to correct myths or misconceptions about how clouds form. Water vapor, condensation, and evaporation are discussed in the context of dew-point temperature and saturation. Educators and anyone explaining cloud formation will find hints on how to present the correct information and avoid misinforming their audiences.

  18. Clouds in Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    West, R.

    1999-01-01

    In the terrestrial atmosphere clouds are familiar as vast collections of small water drops or ice cyrstals suspended in the air. The study of clouds touches on many facets of armospheric science. The chemistry of clouds is tied to the chemistry of the surrounding atmosphere.

  19. CONTRIBUTED Green Cloud Computing

    E-print Network

    Tucker, Rod

    CONTRIBUTED P A P E R Green Cloud Computing: Balancing Energy in Processing, Storage, and Transport to energy consumption and cloud computing seems to be an alternative to office-based computing. By Jayant computing is rapidly expanding as an alternative to conventional office-based computing. As cloud computing

  20. Research Cloud Computing Recommendations

    E-print Network

    Qian, Ning

    Research Cloud Computing Recommendations SRCPAC December 3, 2014 #12;Mandate and Membership SRCPAC convened this committee in Sept 2014 to investigate the role that cloud computing should play in our of research computing projects would be more cost effective to run on the cloud than on Yeti? · What

  1. Towards Trusted Cloud Computing

    Microsoft Academic Search

    Nuno Santos; Krishna P. Gummadi; Rodrigo Rodrigues

    Cloud computing infrastructures enable companies to cut costs by outsourcing computations on-demand. How- ever, clients of cloud computing services currently have no means of verifying the confidentiality and integrity of their data and computation. To address this problem we propose the design of a trusted cloud computing platform (TCCP). TCCP en- ables Infrastructure as a Service (IaaS) providers such as

  2. Vector curvaton without instabilities

    NASA Astrophysics Data System (ADS)

    Dimopoulos, Konstantinos; Kar?iauskas, Mindaugas; Wagstaff, Jacques M.

    2010-01-01

    A vector curvaton model with a Maxwell kinetic term and varying kinetic function and mass during inflation is studied. It is shown that, if light until the end of inflation, the vector field can generate statistical anisotropy in the curvature perturbation spectrum and bispectrum, with the latter being predominantly anisotropic. If by the end of inflation the vector field becomes heavy, then particle production is isotropic and the vector curvaton can alone generate the curvature perturbation. The model does not suffer from instabilities such as ghosts and is the only concrete model, to date, which can produce the curvature perturbation without direct involvement of fundamental scalar fields.

  3. Society for Vector Ecology

    NSDL National Science Digital Library

    Formed in 1968, the Society for Vector Ecology (SOVE) is dedicated to studying "all aspects of the biology, ecology, and control of arthropod vectors and the interrelationships between the vectors and the disease agents they transmit." Comprised of researchers and operational and extension personnel around the globe, SOVE tracks and studies the biological organisms that transmit diseases. The SOVE Website contains information related to the Society (e.g., mission, history), its publications (journal, newsletter -- both .pdf format), and professional opportunities (conferences, employment). Several dozen links to additional vector ecology resources are provided.

  4. Cloud Scaling Properties and Cloud Parameterization

    NASA Technical Reports Server (NTRS)

    Cahalan, R. F.; Morcrette, J. J.

    1998-01-01

    Cloud liquid and cloud traction variability is studied as a function of horizontal scale in the ECMWF forecast model during several 10-day runs at the highest available model resolution, recently refined from approximately 60 km (T213) down to approximately 20 km (T639). At higher resolutions, model plane-parallel albedo biases are reduced, so that models may be tuned to have larger, more realistic, cloud liquid water amounts, However, the distribution of cloud liquid assumed -within- each gridbox, for radiative and thermodynamic computations, depends on ad hoc assumptions that are not necessarily consistent with observed scaling properties, or with scaling properties produced by the model at larger scales. To study the larger-scale cloud properties, ten locations on the Earth are chosen to coincide with locations having considerable surface data available for validation, and representing a variety of climatic regimes, scaling exponents are determined from a range or scales down to model resolution, and are re-computed every three hours, separately for low, medium and high clouds, as well as column-integrated cloudiness. Cloud variability fluctuates in time, due to diurnal, synoptic and other' processes, but scaling exponents are found to be relatively stable. various approaches are considered for applying computed cloud scaling to subgrid cloud distributions used for radiation, beyond simple random or maximal overlap now in common use. Considerably more work is needed to compare model cloud scaling with observations. This will be aided by increased availability of high-resolution surface, aircraft and satellite data, and by the increasing resolution of global models,

  5. Motion Simulator

    NASA Technical Reports Server (NTRS)

    1993-01-01

    MOOG, Inc. supplies hydraulic actuators for the Space Shuttle. When MOOG learned NASA was interested in electric actuators for possible future use, the company designed them with assistance from Marshall Space Flight Center. They also decided to pursue the system's commercial potential. This led to partnership with InterActive Simulation, Inc. for production of cabin flight simulators for museums, expositions, etc. The resulting products, the Magic Motion Simulator 30 Series, are the first electric powered simulators. Movements are computer-guided, including free fall to heighten the sense of moving through space. A projection system provides visual effects, and the 11 speakers of a digital laser based sound system add to the realism. The electric actuators are easier to install, have lower operating costs, noise, heat and staff requirements. The U.S. Space & Rocket Center and several other organizations have purchased the simulators.

  6. Olympic Motion

    NSDL National Science Digital Library

    2010-01-01

    The following resource is fromLessonopoly, which has created student activities and lesson plans to support the video series, Science of the Olympic Winter Games, created by NBC Learn and the National Science Foundation. Featuring exclusive footage from NBC Sports and contributions from Olympic athletes and NSF scientists, the series will help teach your students valuable scientific concepts. In this particular lesson, students will learn about motion and their body at two different levels: cellular and muscular. Students will examine human blood to identify its basic components and will conduct a test to determine their reflex reaction time. Students will also create a flow chart to show the role of cells in muscle contraction.

  7. Computing and Partitioning Cloud Feedbacks Using Cloud Property Histograms. Part I: Cloud Radiative Kernels

    E-print Network

    Hartmann, Dennis

    Computing and Partitioning Cloud Feedbacks Using Cloud Property Histograms. Part I: Cloud Radiative 2011) ABSTRACT This study proposes a novel technique for computing cloud feedbacks using histograms integrated cloud feedbacks computed in this manner agree remarkably well with the adjusted change in cloud

  8. Mixed-phase cloud phase partitioning using millimeter wavelength cloud radar Doppler velocity spectra

    NASA Astrophysics Data System (ADS)

    Yu, G.; Verlinde, J.; Clothiaux, E. E.; Chen, Y.-S.

    2014-06-01

    Retrieving and quantifying cloud liquid drop contributions to radar returns from mixed-phase clouds remains a challenge because the radar signal is frequently dominated by the returns from the ice particles within the radar sample volume. We present a technique that extracts the weak cloud liquid drop contributions from the total radar returns in profiling cloud radar Doppler velocity spectra. Individual spectra are first decomposed using a continuous wavelet transform, the resulting coefficients of which are used to identify the region in the spectra where cloud liquid drops contribute. By assuming that the liquid contribution to each Doppler spectrum is Gaussian shaped and centered on an appropriate peak in the wavelet coefficients, the cloud liquid drop contribution may be estimated by fitting a Gaussian distribution centered on the velocity of this peak to the original Doppler spectrum. The cloud liquid drop contribution to reflectivity, the volume mean vertical air motion, subvolume vertical velocity variance, and ice particle mean fall speed can be estimated based on the separation of the liquid contribution to the radar Doppler spectrum. The algorithm is evaluated using synthetic spectra produced from output of a state-of-the-art large eddy simulation model study of an Arctic mixed-phase cloud. The retrievals of cloud liquid drop mode reflectivities were generally consistent with the original model values with errors less than a factor of 2. The retrieved volume mean vertical air velocities reproduced the updraft and downdraft structures, but with an overall bias of approximately -0.06 m s-1. Retrievals based on Ka-band Atmospheric Radiation Measurement Program Zenith Radar observations from Barrow, Alaska, during October 2011 are also presented.

  9. Vector-valued Malvar wavelets

    NASA Astrophysics Data System (ADS)

    Xia, Xiang-Gen; Suter, Bruce W.; Huang, Ying

    1996-06-01

    Scalar-valued Malvar wavelets have been used to eliminate the blocking effects in scalar transform coding. In this paper, we introduce vector-valued Malvar wavelets for vector-valued signals. While constructing window vectors, we present a connection between vector-valued Malvar wavelets and vector Lemarie-Meyer band-limited wavelets. Similar to scalar-valued Malvar wavelets, vector-valued Malvar wavelets have applications in eliminating the blocking effects in vector transform coding.

  10. The Nystrom method for functional quantization with an application to the fractional Brownian motion

    E-print Network

    Paris-Sud XI, Université de

    quantization of the fractional Brownian motion by approximating the first terms of its Karhunen with the fractional Brownian motion. Keywords: integral equation, Nystr¨om method, Gaussian semi-martingale, functional quantization, vector quantization, Karhunen-Lo`eve basis, Gaussian process, Brownian motion

  11. Turbulent Flows within Self-gravitating Magnetized Molecular Clouds

    Microsoft Academic Search

    D. S. Balsara; R. M. Crutcher; A. Pouquet

    2001-01-01

    Self-gravitating magnetized flows are explored numerically in slab geometry. In this approximation, the derivatives are computed only in one dimension but all three components of vector fields are retained. This is done for a range of fiducial values for the interstellar medium at the scale of molecular clouds. The overall characteristic scale of the turbulence, its Mach number, and the

  12. Denoising 2-D Vector Fields by Vector Wavelet Thresholding

    E-print Network

    Westenberg, Michel A.

    Denoising 2-D Vector Fields by Vector Wavelet Thresholding Michel A. Westenberg and Thomas Ertl for denoising 2-D vector fields that are corrupted by additive noise. The method is based on the vector wavelet introduce modifications to scalar wavelet coefficient thresholding for dealing with vector

  13. Cloud microstructure studies

    NASA Technical Reports Server (NTRS)

    Blau, H. H., Jr.; Fowler, M. G.; Chang, D. T.; Ryan, R. T.

    1972-01-01

    Over two thousand individual cloud droplet size distributions were measured with an optical cloud particle spectrometer flown on the NASA Convair 990 aircraft. Representative droplet spectra and liquid water content, L (gm/cu m) were obtained for oceanic stratiform and cumuliform clouds. For non-precipitating clouds, values of L range from 0.1 gm/cu m to 0.5 gm/cu m; with precipitation, L is often greater than 1 gm/cu m. Measurements were also made in a newly formed contrail and in cirrus clouds.

  14. Introduction to Clouds

    NSDL National Science Digital Library

    George Tselioudis

    1997-01-01

    This site provides the user an opportunity to explore storm clouds and climate change through the use of NASA climate research data obtained through satellite imaging. The user is challenged to investigate actual scientific research data on clouds and storms, and make observations and interpretations available to NASA research scientists for review. Topics addressed by these investigations include the role of clouds in relation to the changing climate of Earth, the role of clouds in warming or cooling the planet, and the major types of clouds produced by storms.

  15. THE WATER CYCLE/ CLOUDS

    NSDL National Science Digital Library

    Ms.Brown

    2009-04-06

    Students will learn about the water cycle and how it works. You will explore many resources to find out many new factors about the water cycle. What is the water cycle? National water cycle Name the 4 water parts of the water cycle? Weather wonders Where are 3 places that the water cycle exists- What happens after condensation? animated water cycle Name 4 types of clouds? What is the highest level cloud called? Which cloud is associated with powerful thunderstorms? Cloud Types What do clouds have to do with the water cycle? National water cycle What is ...

  16. Corona Discharge in Clouds

    NASA Astrophysics Data System (ADS)

    Sin'kevich, A. A.; Dovgalyuk, Yu. A.

    2014-04-01

    We present a review of the results of theoretical studies and laboratory modeling of corona discharge initiation in clouds. The influence of corona discharges on the evolution of the cloud microstructure and electrification is analyzed. It is shown that corona discharges are initiated when large-size hydrometeors approach each other, whereas in some cases, corona discharges from crystals, ice pellets, and hailstones can appear. The corona discharges lead to significant air ionization, charging of cloud particles, and separation of charges in clouds and initiate streamers and lightnings. The influence of corona discharges on changes in the phase composition of clouds is analyzed.

  17. The dependence of clouds and their radiative impacts on the large-scale vertical velocity

    Microsoft Academic Search

    Jian Yuan

    2007-01-01

    Middle-tropospheric vertical velocity(o500) is used to isolate the effect of large-scale dynamics on the observed radiation budget and cloud properties in the Tropics. The ratio of shortwave to longwave cloud forcing (N=-SWCF\\/LWCF) is approximately 1.2 and independent of the magnitude of w5oo when it is upward over the warmer water. Increasingly negative net cloud forcing (NetCRF) with increasing upward motion

  18. Tvashtar in Motion

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This five-frame sequence of New Horizons images captures the giant plume from Io's Tvashtar volcano. Snapped by the probe's Long Range Reconnaissance Imager (LORRI) as the spacecraft flew past Jupiter earlier this year, this first-ever 'movie' of an Io plume clearly shows motion in the cloud of volcanic debris, which extends 330 kilometers (200 miles) above the moon's surface. Only the upper part of the plume is visible from this vantage point -- the plume's source is 130 kilometers (80 miles) below the edge of Io's disk, on the far side of the moon.

    The appearance and motion of the plume is remarkably similar to an ornamental fountain on Earth, replicated on a gigantic scale. The knots and filaments that allow us to track the plume's motion are still mysterious, but this movie is likely to help scientists understand their origin, as well as provide unique information on the plume dynamics.

    Io's hyperactive nature is emphasized by the fact that two other volcanic plumes are also visible off the edge of Io's disk: Masubi at the 7 o'clock position, and a very faint plume, possibly from the volcano Zal, at the 10 o'clock position. Jupiter illuminates the night side of Io, and the most prominent feature visible on the disk is the dark horseshoe shape of the volcano Loki, likely an enormous lava lake. Boosaule Mons, which at 18 kilometers (11 miles) is the highest mountain on Io and one of the highest mountains in the solar system, pokes above the edge of the disk on the right side.

    The five images were obtained over an 8-minute span, with two minutes between frames, from 23:50 to 23:58 Universal Time on March 1, 2007. Io was 3.8 million kilometers (2.4 million miles) from New Horizons; the image is centered at Io coordinates 0 degrees north, 342 degrees west.

    The pictures were part of a sequence designed to look at Jupiter's rings, but planners included Io in the sequence because the moon was passing behind Jupiter's rings at the time.

  19. Decoding pattern motion information in V1.

    PubMed

    van Kemenade, Bianca M; Seymour, Kiley; Christophel, Thomas B; Rothkirch, Marcus; Sterzer, Philipp

    2014-08-01

    When two gratings drifting in different directions are superimposed, the resulting stimulus can be perceived as two overlapping component gratings moving in different directions or as a single pattern moving in one direction. Whilst the motion direction of component gratings is already represented in visual area V1, the majority of previous studies have found processing of pattern motion direction only from visual area V2 onwards. Here, we question these findings using multi-voxel pattern analysis (MVPA). In Experiment 1, we presented superimposed sinusoidal gratings with varying angles between the two component motions. These stimuli were perceived as patterns moving in one of two possible directions. We found that linear support vector machines (SVMs) could generalise across stimuli composed of different component motions to successfully discriminate pattern motion direction from brain activity in V1, V3A and hMT+/V5. This demonstrates the representation of pattern motion information present in these visual areas. This conclusion was verified in Experiment 2, where we manipulated similar plaid stimuli to induce the perception of either a single moving pattern or two separate component gratings. While a classifier could again generalise across stimuli composed of different component motions when they were perceived as a single moving pattern, its performance dropped substantially in the case where components were perceived. Our results indicate that pattern motion direction information is present in V1. PMID:24905972

  20. Lapped Orthogonal Vector Quantization

    Microsoft Academic Search

    Henrique S. Malvar; Gary J. Sullivan; Gregory W. Wornell

    1996-01-01

    The blocking artifacts that arise in the use of traditional vector quantization (VQ) schemes can, in general, be virtually eliminated via an efficient lapped VQ strategy. With lapped VQ, blocks are obtained from the source in an overlapped manner, and reconstructed via superposition of overlapped codevectors. The new scheme, which we term lapped orthogonal vector quantization (LOVQ), requires no increase

  1. Insect vector transmission assays.

    PubMed

    Bosco, Domenico; Tedeschi, Rosemarie

    2013-01-01

    Phytoplasmas are transmitted in a persistent propagative manner by phloem-feeding vectors belonging to the order Hemiptera, suborder Homoptera. Following acquisition from the infected source plant, there is a latent period before the vector can transmit, so transmission assays consist of three basic steps: acquisition, latency, and inoculation. More than 90 vector species (plant-, leafhoppers, and psyllids) have been discovered so far but many others are still undiscovered, and their role in spreading economically important crop diseases is neglected. Therefore, screening for vectors is an essential step in developing rational control strategies targeted against the actual vectors for phytoplasma-associated diseases. The mere detection of a phytoplasma in an insect does not imply that the insect is a vector; a transmission assay is required to provide conclusive evidence. Transmission experiments can be carried out using insects from phytoplasma-free laboratory colonies or field-collections. Moreover, transmission assays can be performed by feeding vectors on an artificial diet through Parafilm(®), after which phytoplasmas can be detected in the sucrose feeding medium by PCR. Transmission trials involve the use of different techniques according to the biology of the different vector species; planthoppers, leafhoppers, and psyllids. PMID:22987407

  2. New Support Vector Algorithms

    Microsoft Academic Search

    Bernhard Schölkopf; Alex J. Smola; Robert C. Williamson; Peter L. Bartlett

    2000-01-01

    We propose a new class of support vector algorithms for regression and classification. In these algorithms, a parameter ? lets one effectively control the number of support vectors. While this can be useful in its own right, the parameterization has the additional benefit of enabling us to eliminate one of the other free parameters of the algorithm: the accuracy parameter

  3. Movie of High Clouds on Jupiter

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Jupiter's high-altitude clouds are seen in this brief movie made from seven frames taken by the narrow-angle camera of NASA's Cassini spacecraft. This is the first time a movie sequence of Jupiter has been made that illustrates the motions of the high-altitude clouds on a global scale.

    The images were taken at a wavelength that is absorbed by methane, one chemical in Jupiter's lower clouds. So, dark areas are relatively free of high clouds, and the camera sees through to the methane in a lower level. Bright areas are places with high, thick clouds that shield the methane below.

    Jupiter's equator and Great Red Spot are covered with high-altitude, hazy clouds.

    The movie covers the time period between Oct. 1 and Oct. 5, 2000, latitudes from 50 degrees north to 50 degrees south, and a 100-degree sweep of longitude. Those factors were the same for a Cassini movie of cloud motions previously released (PIA02829), but that movie used frames taken through a blue filter, which showed deeper cloud levels and sharper detail. Features in this methane-filter movie appear more diffuse.

    Among the nearly stationary features are the Red Spot and some bright ovals at mid-latitudes in both hemispheres. These are anticyclonic (counter-clockwise rotating) storms. They are bright in the methane band because of their high clouds associated with rising gas. They behave differently from terrestrial cyclones, which swirl in the opposite direction. The mechanism making the Red Spot and similar spots stable apparently has no similarity to the mechanism which feeds terrestrial cyclones.

    Some small-scale features are fascinating because of their brightness fluctuations. Such fluctuations observed in the methane band are probably caused by strong vertical motions, which form clouds rapidly, as in Earth's thunderstorms. Near the upper left corner in this movie, a number of smaller clouds appear to circulate counterclockwise around a dark spot, and these clouds fluctuate in brightness, so they may be candidates for lightning storms.

    A pattern of lighter areas between darker patches can be seen in the darkest band a little north of the bright equatorial region. This may be tied to a wave-like temperature variation across the planet. If confirmed, this would be the first time such large-scale stratospheric temperature waves have been visibly linked to variations in haze thickness.

    Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C.

  4. Vector Piezoresponse Force Microscopy

    SciTech Connect

    Kalinin, Sergei V [ORNL; Rodriguez, Brian J [ORNL; Jesse, Stephen [ORNL; Shin, Junsoo [ORNL; Baddorf, Arthur P [ORNL; Gupta, P. [Lehigh University, Bethlehem, PA; Jain, H. [Lehigh University, Bethlehem, PA; Williams, D. B. [Lehigh University, Bethlehem, PA; Gruverman, A. [North Carolina State University

    2006-01-01

    A novel approach for nanoscale imaging and characterization of the orientation dependence of electromechanical properties - vector piezoresponse force microscopy (Vector PFM) - is described. The relationship between local electromechanical response, polarization, piezoelectric constants, and crystallographic orientation is analyzed in detail. The image formation mechanism in vector PFM is discussed. Conditions for complete three-dimensional (3D) reconstruction of the electromechanical response vector and evaluation of the piezoelectric constants from PFM data are set forth. The developed approach can be applied to crystallographic orientation imaging in piezoelectric materials with a spatial resolution below 10 nm. Several approaches for data representation in 2D-PFM and 3D-PFM are presented. The potential of vector PFM for molecular orientation imaging in macroscopically disordered piezoelectric polymers and biological systems is discussed.

  5. Cloud Computing Security: From Single to Multi-clouds

    Microsoft Academic Search

    Mohammed A. AlZain; Eric Pardede; Ben Soh; James A. Thom

    2012-01-01

    The use of cloud computing has increased rapidly in many organizations. Cloud computing provides many benefits in terms of low cost and accessibility of data. Ensuring the security of cloud computing is a major factor in the cloud computing environment, as users often store sensitive information with cloud storage providers but these providers may be untrusted. Dealing with \\

  6. Working inside the Cloud: Developing a Cloud Computing Infrastructure

    E-print Network

    Krause, Rolf

    UROP 2012 Working inside the Cloud: Developing a Cloud Computing Infrastructure Cloud computing and live-migration of running VM. USI participates to the development of the first European Cloud computing for a motivated student that will have a chance to improve his/her knowledge on Cloud computing, Java and/or Ruby

  7. Transport, Collective Motion, and Brownian Motion

    Microsoft Academic Search

    Hazime Mori

    1965-01-01

    A theory of many-particle systems is developed to formulate transport, collective motion, and Brownian motion from a unified, statistical-mechanical point of view. This is done by, first, rewriting the equation of motion in a generalized form of the Langevin equation in the stochastic theory of Brownian motion and then, either studying the average evolution of a non-equilibrium system or calculating

  8. Automatic Motion Segmentation for Human Motion Synthesis

    Microsoft Academic Search

    Sebastian Schulz; Annika Woerner

    2010-01-01

    \\u000a Motion segmentation is one of the key techniques in the context of motion analysis and generation. The basic idea is to split\\u000a motion capture data into continuous segments that can be used to generate new motion sequences. For most applications, this\\u000a segmentation is done manually leading to inaccurate and inconsistent results. This makes it difficult to conceive general\\u000a methods for

  9. Watershed-based Separation of Atmospheric Input Vectors

    NASA Astrophysics Data System (ADS)

    Walter, M.; Hedin, L. O.

    2002-12-01

    We used a watershed mass balance approach to quantify nutrients input to remote unpolluted Chilean forests via the three dominant atmospheric vectors: 1) precipitation deposition; 2) cloud deposition; and 3) dry deposition. Precipitation deposition was calculated by integrating precipitation chemistry and volume over time. We estimated cloud deposition by combining direct measures of cloud chemistry with cloud water deposition calculated using a watershed hydrologic mass balance. We further examined how sensitive these calculations are to realistic errors in key parameters, including statistical distribution of element concentrations across cloud water events, errors in the overall hydrologic budget, and analysis of precipitation chemistry. We calculated dry deposition by difference, as the term that remains unresolved after accounting for precipitation and cloud inputs and after correcting watershed losses for weathering inputs (using an aerosol sea-salt ratio approach) and for net biomass uptake. Previous research has shown biomass uptake to be minimal or negligible in this old-growth forest. Our results show that dry deposition accounts for about 25-30% of the base cations and chloride inputs into this system. A substantial portion of the nitrogen budget appears to be due to cloud inputs (~15%) but over 50% of the budget remained unresolved by this simple approach. Phosphorus and dissolved organic carbon showed similarly large unresolved portions of their budgets. Corroborating the methodology, chloride:element ratios determined for the calculated dry deposition components of the cations agreed well with theoretical sea-salt aerosol ratios for the same elements. The dry deposited chloride:sulfate ratio was somewhat lower than for sea-salt aerosols, possibly suggesting internal sulfate reduction. Because our watershed mass balance record extends over several years, we were able to examine and account for variations in each of these deposition vectors across years with differing climatic conditions.

  10. Inhomogeneous cirrus clouds during the AIRTOSS campaign

    NASA Astrophysics Data System (ADS)

    Voigt, Matthias; Spichtinger, Peter

    2015-04-01

    The aircraft campaign AIRTOSS-ICE in May and September 2013 provided measurement data of cirrus clouds over North Sea and Baltic Sea in various meteorological situations. The measurements were carried out with a Learjet and a towed sensor shuttle below the aircraft [2]. This configuration allows us to obtain almost horizontally collocated measurements at different vertical levels (inside and outside clouds). Microphysical properties of cirrus clouds, as ice water content, ice crystal number concentrations, diameter and shape of ice crystals were measured. In this study we concentrate on the comparison of in situ measurements with model simulations. For these case studies, the issue about the main formation mechanism (homogeneous vs. heterogeneous or both) will be addressed. In a first step the meteorological conditions leading to the cirrus formation are analyzed using meteorological analyses as obtained from the European Centre for Medium-Range Forecasts (ECMWF). The ECMWF wind fields are then used to calculate backward trajectories with the Lagrangian analysis tool LAGRANTO [4]. From these investigations the large-scale/mesoscale motions are derived and analyzed. Finally, the meteorological analyses and measurements (temperature, wind, humidity) are used as initial conditions for cirrus cloud simulations where the small scale motions are derived and analyzed. We used EULAG as LES model, including a state-of-the-art ice microphysics scheme [3] for 2D and 3D idealized and quasi-realistic simulations. In order to address the impact of dynamics vs. microphysics (i.e. heterogeneous nucleation [1]), we investigated different environmental conditions. The microphysical and macrophysical properties of the simulated cloud are finally compared to the measurements, in order to get some information about the most probable scenarios. References [1] D. J. Cziczo, K. D. Froyd, C. Hoose, E. J. Jensen, M. H. Diao, M. A. Zondlo, J. B. Smith, C. H. Twohy, and D. M. Murphy. Clarifying the dominant sources and mechanisms of cirrus cloud formation. Science, 340(6138):1320-1324, June 2013. [2] W. Frey, H. Eichler, M. de Reus, R. Maser, M. Wendisch, and S. Borrmann. A new airborne tandem platform for collocated measurements of microphysical cloud and radiation properties. Atmospheric Measurement Techniques, 2(1):147-158, 2009. [3] P. Spichtinger and K. M. Gierens. Modelling of cirrus clouds part 1a: Model description and validation. Atmospheric Chemistry and Physics, 9(2):685-706, 2009. [4] H. Wernli and H. C. Davies. A lagrangian-based analysis of extratropical cyclones .1. the method and some applications. Quarterly Journal of the Royal Meteorological Society, 123(538):467-489, January 1997.

  11. Chemical cloud tracking systems

    NASA Astrophysics Data System (ADS)

    Grim, Larry B.; Gruber, Thomas C., Jr.; Marshall, Martin; Rowland, Brad

    2002-02-01

    This paper describes the Chemical Cloud Tracking System (CCTS) which has been installed at Dugway Proving Ground. The CCTS allows mapping of chemical clouds in real time from a safe standoff distance. The instruments used are passive standoff chemical agent detectors (FTIRs). Each instrument individually can only measure the total of all the chemical in its line-of-site; the distance to the cloud is unknown. By merging data from multiple vantage points (either one instrument moving past the cloud or two or more instruments spaced so as to view the cloud from different directions) a map of the cloud locations can be generated using tomography. To improve the sensitivity and accuracy of the cloud map, chemical point sensors can be added to the sensor array being used. The equipment required for the CCTS is commercially available. Also, the data fusion techniques (tomography) have been demonstrated previously in the medical field. The Chemical Cloud Tracking System can monitor the movement of many chemical clouds of either military or industrial origin. Since the technique is standoff, the personnel are not exposed to toxic hazards while they follow the cloud. Also, the equipment works on-the-move which allows rapid response to emergency situations (plant explosions, tanker car accidents, chemical terrorism, etc.).

  12. Vehicle tracking and motion prediction in complex urban scenarios

    Microsoft Academic Search

    Christoph Hermes; Julian Einhaus; Markus Hahn; C. Wo?hler; Franz Kummert

    2010-01-01

    The recognition of potentially hazardous situations on road intersections is an indispensable skill of future driver assistance systems. In this context, this study focuses on the task of vehicle tracking in combination with a long-term motion prediction (1-2 s into the future) in a dynamic scenario. A motion-attributed stereo point cloud obtained using computationally efficient feature-based methods represents the scene,

  13. Silicon photonics cloud (SiCloud)

    NASA Astrophysics Data System (ADS)

    DeVore, Peter T. S.; Jiang, Yunshan; Lynch, Michael; Miyatake, Taira; Carmona, Christopher; Chan, Andrew C.; Muniam, Kuhan; Jalali, Bahram

    2015-02-01

    We present SiCloud (Silicon Photonics Cloud), the first free, instructional web-based research and education tool for silicon photonics. SiCloud's vision is to provide a host of instructional and research web-based tools. Such interactive learning tools enhance traditional teaching methods by extending access to a very large audience, resulting in very high impact. Interactive tools engage the brain in a way different from merely reading, and so enhance and reinforce the learning experience. Understanding silicon photonics is challenging as the topic involves a wide range of disciplines, including material science, semiconductor physics, electronics and waveguide optics. This web-based calculator is an interactive analysis tool for optical properties of silicon and related material (SiO2, Si3N4, Al2O3, etc.). It is designed to be a one stop resource for students, researchers and design engineers. The first and most basic aspect of Silicon Photonics is the Material Parameters, which provides the foundation for the Device, Sub-System and System levels. SiCloud includes the common dielectrics and semiconductors for waveguide core, cladding, and photodetection, as well as metals for electrical contacts. SiCloud is a work in progress and its capability is being expanded. SiCloud is being developed at UCLA with funding from the National Science Foundation's Center for Integrated Access Networks (CIAN) Engineering Research Center.

  14. A modified algorithm for generation of 3D GVF field from point cloud

    NASA Astrophysics Data System (ADS)

    Liu, Shoubin; Niu, Wenguang

    2012-01-01

    This paper presents an algorithm for generation of a force field from point cloud in three-dimensional space. The force field is calculated based on the approach of gradient vector flow (GVF). Therefore, the force field is named as 3D GVF field. By converting the point cloud into a 3D edge image, the algorithm diffuses the gradient of 3D edge image along the gradient direction of 3D edge image. The generated 3D GVF field of point cloud can be further used for point cloud processing such as segmentation, reparation or recognition.

  15. Inline motion in flapping foils for improved force vectoring performance

    E-print Network

    Izraelevitz, Jacob (Jacob Samuel)

    2013-01-01

    In this thesis, I study the effect of adding in-line oscillation to heaving and pitching foils using a power downstroke. I show that far from being a limitation imposed by the muscular structure of certain animals, in-line ...

  16. Scanning Cloud Radar Observations at the ARM sites

    NASA Astrophysics Data System (ADS)

    Kollias, P.; Clothiaux, E. E.; Shupe, M.; Widener, K.; Bharadwaj, N.; Miller, M. A.; Verlinde, H.; Luke, E. P.; Johnson, K. L.; Jo, I.; Tatarevic, A.; Lamer, K.

    2012-12-01

    Recently, the DOE Atmospheric Radiation Measurement (ARM) program upgraded its fixed and mobile facilities with the acquisition of state-of-the-art scanning, dual-wavelength, polarimetric, Doppler cloud radars. The scanning ARM cloud radars (SACR's) are the most expensive and significant radar systems at all ARM sites and eight SACR systems will be operational at ARM sites by the end of 2013. The SACR's are the primary instruments for the detection of 3D cloud properties (boundaries, volume cloud fractional coverage, liquid water content, dynamics, etc.) beyond the soda-straw (profiling) limited view. Having scanning capabilities with two frequencies and polarization allows more accurate probing of a variety of cloud systems (e.g., drizzle and shallow, warm rain), better correction for attenuation, use of attenuation for liquid water content retrievals, and polarimetric and dual-wavelength ratio characterization of non-spherical particles for improved ice crystal habit identification. Examples of SACR observations from four ARM sites are presented here: the fixed sites at Southern Great Plains (SGP) and North Slope of Alaska (NSA), and the mobile facility deployments at Graciosa Island, Azores and Cape Cod, Massachusetts. The 3D cloud structure is investigated both at the macro-scale (20-50 km) and cloud-scale (100-500 m). Doppler velocity measurements are corrected for velocity folding and are used either to describe the in-cloud horizontal wind profile or the 3D vertical air motions.

  17. Cloud computing and security challenges

    Microsoft Academic Search

    Huiming Yu; Nakia Powell; Dexter Stembridge; Xiaohong Yuan

    2012-01-01

    Cloud Computing recently emerged as a promising solution to information technology (IT) management. IT managers look to cloud computing as a means to maintain a flexible and scalable IT infrastructure that enables business agility. In this paper Cloud Computing services including data storage service, cloud computing operating system and software as a service will be introduced, Cloud Computing security challenges

  18. Taxonomy of cloud computing services

    Microsoft Academic Search

    C. N. Hoefer; G. Karagiannis

    2010-01-01

    Cloud computing is a highly discussed topic, and many big players of the software industry are entering the development of cloud services. Several companies want to explore the possibilities and benefits of cloud computing, but with the amount of cloud computing services increasing quickly, the need for a taxonomy framework rises. This paper describes the available cloud computing services, and

  19. An Autonomous Reliabilit Cloud Comput

    E-print Network

    Buyya, Rajkumar

    An Autonomous Reliabilit Ami Cloud Comput Department of Computing and Informa Abstract--Cloud computing paradigm allo based access to computing and storages s Internet. Since with advances of Cloud. Keywords- Cloud computing; SLA negotiat I. INTRODUCTION Cloud computing has transferred the services

  20. Introduction to Clouds

    NSDL National Science Digital Library

    This site gives students an opportunity to explore storm clouds and climate change through the use of National Aeronautic and Space Administration (NASA) climate research data obtained through satellite imaging. The challenge is to investigate actual scientific research data on clouds and storms, and make the resulting observations and interpretations available to NASA research scientists for review. The interactive site will allow students to discover what the major types of clouds produced by storms are and whether these clouds help to cool or warm the Earth's surface. Storms are the major producers of clouds in the Earth's atmosphere, so students investigate the relationship between the types of clouds in order to make their conclusions.

  1. Time Varying Structural Vector Autoregressions and Monetary Policy

    Microsoft Academic Search

    Giorgio E. Primiceri

    2004-01-01

    Monetary policy and the private sector behavior of the US economy are modeled as a time varying structural vector autoregression, where the sources of time variation are both the co- efficients and the variance covariance matrix of the innovations. The paper develops a new, simple modeling strategy for the law of motion of the variance covariance matrix and proposes an

  2. Time Varying Structural Vector Autoregressions and Monetary Policy

    Microsoft Academic Search

    Giorgio E. Primiceri

    2005-01-01

    Monetary policy and the private sector behaviour of the U.S. economy are modelled as a time varying structural vector autoregression, where the sources of time variation are both the coefficients and the variance covariance matrix of the innovations. The paper develops a new, simple modelling strategy for the law of motion of the variance covariance matrix and proposes an efficient

  3. Double production of vector quarkonia in exclusive Higgs boson decays

    SciTech Connect

    Kartvelishvili, V. G., E-mail: V.Kartvelishvili@lancaster.ac.u [University of Lancaster (United Kingdom); Luchinsky, A. V., E-mail: Alexey.Luchinsky@ihep.ru; Novoselov, A. A., E-mail: Alexey.Novoselov@cern.c [Institute for High Energy Physics (Russian Federation)

    2010-06-15

    Partial widths with respect to the exclusive decays of Standard Model Higgs bosons to pairs of vector quarkonia, H {sup {yields}}J/{psi}J/{psi}, H {sup {yields}}YY, H {sup {yields}}J/{psi}{phi}, and H {sup {yields}}J/{psi}Y, were calculated with allowance for relativistic corrections associated with the internal motion of quarks in qarkonia.

  4. Energy Aware Clouds

    Microsoft Academic Search

    Anne-Cécile Orgerie; Marcos Dias de Assunção; Laurent Lefèvre

    2011-01-01

    \\u000a Cloud infrastructures are increasingly becoming essential components for providing Internet services. By benefiting from economies\\u000a of scale, Clouds can efficiently manage and offer a virtually unlimited number of resources and can minimize the costs incurred\\u000a by organizations when providing Internet services. However, as Cloud providers often rely on large data centres to sustain\\u000a their business and offer the resources that

  5. Flat Bottom Clouds

    NSDL National Science Digital Library

    David Robison

    In this activity, students investigate how pressure affects the temperature of air and how this relates to the formation of clouds in the troposphere. They will form a cloud in a bottle, find the dew point and relative humidity of air at different places in the school and use a chart to estimate how high that air would have to rise to form a cloud.

  6. Cloud Infrastructure Security

    Microsoft Academic Search

    Dimiter Velev; Plamena Zlateva

    2010-01-01

    \\u000a Cloud computing can help companies accomplish more by eliminating the physical bonds between an IT infrastructure and its\\u000a users. Users can purchase services from a cloud environment that could allow them to save money and focus on their core business.\\u000a At the same time certain concerns have emerged as potential barriers to rapid adoption of cloud services such as security,

  7. Ammonia Clouds on Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Click on the image for movie of Ammonia Ice Clouds on Jupiter

    In this movie, put together from false-color images taken by the New Horizons Ralph instrument as the spacecraft flew past Jupiter in early 2007, show ammonia clouds (appearing as bright blue areas) as they form and disperse over five successive Jupiter 'days.' Scientists noted how the larger cloud travels along with a small, local deep hole.

  8. New techniques in 3D scalar and vector field visualization

    SciTech Connect

    Max, N.; Crawfis, R.; Becker, B.

    1993-05-05

    At Lawrence Livermore National Laboratory (LLNL) we have recently developed several techniques for volume visualization of scalar and vector fields, all of which use back-to-front compositing. The first renders volume density clouds by compositing polyhedral volume cells or their faces. The second is a ``splatting`` scheme which composites textures used to reconstruct the scalar or vector fields. One version calculates the necessary texture values in software, and another takes advantage of hardware texture mapping. The next technique renders contour surface polygons using semi-transparent textures, which adjust appropriately when the surfaces deform in a flow, or change topology. The final one renders the ``flow volume`` of smoke or dye tracer swept out by a fluid flowing through a small generating polygon. All of these techniques are applied to a climate model data set, to visualize cloud density and wind velocity.

  9. Microbiologists search the clouds

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    On 22 May, a team of microbiologists used a prototype cloud-catcher mounted on a research plane to collect samples from low-lying cumulus clouds near Oxford, England. The researchers, from the University of East London (UEL), are investigating whether an active and self-sustaining ecosystem exists in clouds, and whether airborne microbes may play an active role in forming clouds and causing rainfall.While scientists have known that microorganisms, including bacteria, fungal spores, and algae, can survive and possibly reproduce in the atmosphere, the challenge, according to the UEL researchers, is to accurately detect, identify, and analyze microbial communities.

  10. Cloud Optimize When it comes to building a private cloud, offering cloud services,

    E-print Network

    Hunt, Galen

    Cloud Optimize Your IT When it comes to building a private cloud, offering cloud services the flexibility of a private cloud, implementing solutions in a virtualized environment is not enough. Windows Server 2012 lets you go beyond virtualization to deploy and more securely connect to private clouds

  11. Poynting-vector filter

    DOEpatents

    Carrigan, Charles R. (Tracy, CA)

    2011-08-02

    A determination is made of frequency components associated with a particular bearing or location resulting from sources emitting electromagnetic-wave energy for which a Poynting-Vector can be defined. The broadband frequency components associated with a specific direction or location of interest are isolated from other components in the power spectrum that are not associated with the direction or location of interest. The collection of pointing vectors can be used to characterize the source.

  12. Bloch vector projection noise

    NASA Technical Reports Server (NTRS)

    Wang, Li-Jun; Bacon, A. M.; Zhao, H.-Z.; Thomas, J. E.

    1994-01-01

    In the optical measurement of the Bloch vector components describing a system of N two-level atoms, the quantum fluctuations in these components are coupled into the measuring optical field. This paper develops the quantum theory of optical measurement of Bloch vector projection noise. The preparation and probing of coherence in an effective two-level system consisting of the two ground states in an atomic three-level lambda-scheme are analyzed.

  13. A driven, trapped, laser cooled ion cloud: a forced damped oscillator

    Microsoft Academic Search

    M. A van Eijkelenborg; K. Dholakia; M. E. M. Storkey; D. M Segal; R. C Thompson

    1999-01-01

    We have studied the efficiency of laser cooling on clouds of magnesium and beryllium ions held in a Penning trap. We applied a driving voltage to the trap electrodes to drive the ions near one of their motional resonances, and studied the difference between the phase of the applied driving voltage and that of the resultant ion motion. Just as

  14. Cloud Computing Synopsis and Recommendations

    E-print Network

    Cloud Computing Synopsis and Recommendations Recommendationsof the National Institute of Standards Publication 800-146 Cloud Computing Synopsis and Recommendations Recommendations of the National Institute and Director #12;CLOUD COMPUTING SYNOPSIS AND RECOMMENDATIONS ii Reports on Computer Systems Technology

  15. Lecture Ch. 8 Cloud Classification

    E-print Network

    Russell, Lynn

    MODIS cloud LWP, and cloud temperature, used to determine adiabatic h PBL Clouds are thin! Adiabatic Drops above this size grow and precipitate Diffusion of water onto ice in water- saturated environment

  16. BROWNIAN MOTION MAXWELL STOLARSKI

    E-print Network

    May, J. Peter

    BROWNIAN MOTION MAXWELL STOLARSKI Abstract. This paper introduces Brownian motion and covers several in- variances of Brownian motion, some of which follow from the definition and another which follows from the strong Markov property of Brownian motion. We go on to show the nondifferentiability

  17. The Motion Coherence Theory

    Microsoft Academic Search

    A. L. Yuille; N. M. Grzywacz

    1988-01-01

    Tliere are a number of important phenom- ena in motion perception involving colicrcnce. Examples include motion capture and motion cooperativity. We propose a theoretical model, called the motion coherence tlieory, that gives a possible explanation for these effects (Yuille and Grzywacz, 1988a,b). In this framework, the aperture problem can also be thought of as a problem of coherence and given

  18. Cloud Ozone Dust Imager (CODI)

    NASA Astrophysics Data System (ADS)

    Clancy, R. Todd; Dusenbery, Paul; Wolff, Michael; James, Phil; Allen, Mark; Goguen, Jay; Kahn, Ralph; Gladstone, Rany; Murphy, Jim

    1995-01-01

    The Cloud Ozone Dust Imager (CODI) is proposed to investigate the current climatic balance of the Mars atmosphere, with particular emphasis on the important but poorly understood roles which dust and water ice aerosols play in this balance. The large atmospheric heating (20-50 K) resulting from global dust storms around Mars perihelion is well recognized. However, groundbased observations of Mars atmospheric temperatures, water vapor, and clouds since the Viking missions have identified a much colder, cloudier atmosphere around Mars aphelion that may prove as important as global dust storms in determining the interannual and long-term behavior of the Mars climate. The key climate issues CODI is designed to investigate are: 1) the degree to which non-linear interactions between atmospheric dust heating, water vapor saturation, and cloud nucleation influence the seasonal and interannual variability of the Mars atmosphere, and 2) whether the strong orbital forcing of atmospheric dust loading, temperatures and water vapor saturation determines the long-term balance of Mars water, as reflected in the north-south hemispheric asymmetries of atmospheric water vapor and polar water ice abundances. The CODI experiment will measure the daily, seasonal and (potentially) interannual variability of atmospheric dust and cloud opacities, and the key physical properties of these aerosols which determine their role in the climate cycles of Mars. CODI is a small (1.2 kg), fixed pointing camera, in which four wide-angle (+/- 70 deg) lenses illuminate fixed filters and CCD arrays. Simultaneous sky/surface imaging of Mars is obtained at an angular resolution of 0.28 deg/pixel for wavelengths of 255, 336, 502, and 673 nm (similar to Hubble Space Telescope filters). These wavelengths serve to measure atmospheric ozone (255 and 336 nm), discriminate ice and dust aerosols (336 and 673 nm), and construct color images (336, 502, and 673 nm). The CODI images are detected on four 512 x 512 pixel arrays, as partitioned on two 1024 x 1024 CCD's operated in frame transfer mode. The center of the CODI field-of-view is canted 40 deg from the zenith direction to obtain sky brightness measurements and a 20 deg surface field-of-view. Daily image observations will be conducted when the Sun is greater than or equal to 5 deg outside the edge of the CODI field-of-view, and twilight and nighttime imaging will obtained on a weekly basis. The 673 nm channel includes a polarizer wheel to obtain sky/surface polarimetry. A dust cover protects the entire lens assemblies of all four CODI channels. This opaque dust cover, which is normally opened for CODI imaging, includes a small fixed mirror and transparent window positioned above the 673 nm lens, to redirect the 673 nm field-of-view to the surface for descent imaging. Fixed pointing, internal data buffering, low operating power (2-4 W for less than or equal to 30 seconds), selective data transmission, and simple operational characteristics of the CODI experiment place minimum resource and operational demands on the Mars Surveyor 1998 lander. The CODI science goals are optimized for, but not restricted to, a low-latitude landing site (20 deg S-30 deg N). The primary CODI measurement objectives are the opacities, wave forms, particle properties (size, shape, and alignment), and heights of clouds; the opacities, particle properties, and vertical distribution of dust; and the opacity and vertical distribution of ozone. The variability of cloud, ozone, and dust opacities will be determined on diurnal, daily, and seasonal timescales. Wind velocities will be determined from cloud motions and wave characteristics; and the temporal variability of atmospheric water vapor, with limited altitude information, will be inferred from the CODI ozone observations. Secondary measurement objectives include limited descent imaging capability, surface uv-visible photometry and polarimetry, photochemistry, and meteorite infall rates.

  19. Observing, Describing, and Identifying Clouds

    NSDL National Science Digital Library

    The GLOBE Program, UCAR (University Corporation for Atmospheric Research)

    2003-08-01

    In this activity students observe and sketch clouds, describing their forms. They initially generate descriptions of a personal nature and then move toward building a more scientific vocabulary. They then correlate their descriptions with the standard classifications using the ten cloud types identified for GLOBE. Each student develops a personal cloud booklet to be used in conjunction with the GLOBE Cloud Chart. . The intended outcome is that students will be able to identify cloud types using standard cloud classification names.

  20. The Case for Cloud Computing

    Microsoft Academic Search

    Robert L. Grossman

    2009-01-01

    To understand clouds and cloud computing, we must first understand the two different types of clouds. The author distinguishes between clouds that provide on-demand computing instances and those that provide on-demand computing capacity. Cloud computing doesn't yet have a standard definition, but a good working description of it is to say that clouds, or clusters of distributed computers, provide on-demand

  1. ISCCP Cloud Algorithm Intercomparison.

    NASA Astrophysics Data System (ADS)

    Rossow, W. B.; Mosher, F.; Kinsella, E.; Arking, A.; Desbois, M.; Harrison, E.; Minnis, P.; Ruprecht, E.; Seze, G.; Simmer, C.; Smith, E.

    1985-09-01

    The International Satellite Cloud Climatology Project (ISCCP) will provide a uniform global climatology of satellite-measured radiances and derive an experimental climatology of cloud radiative properties from these radiances. A pilot study to intercompare cloud analysis algorithms was initiated in 1981 to define a state-of-the-art algorithm for ISCCP. This study compared the results of applying six different algorithms to the same satellite radiance data. The results show that the performance of all current algorithms depends on how accurately the clear sky radiances are specified; much improvement in results is possible with better methods for obtaining these clear-sky radiances. A major difference between the algorithms is caused by their sensitivity to changes in the cloud size distribution and optical properties: all methods, which work well for some cloud types or climate regions, do poorly for other situations. Therefore, the ISCCP algorithm is composed of a series of steps, each of which is designed to detect some of the clouds present in the scene. This progressive analysis is used to retrieve an estimate of the clear sky radiances corresponding to each satellite image. Application of a bispectral threshold is then used as the last step to determine the cloud fraction. Cloudy radiances are interpreted in terms of a simplified model of cloud radiative effects to provide some measure of cloud radiative properties. Application of this experimental algorithm to produce a cloud climatology and field observation programs to validate the results will stimulate further research on cloud analysis techniques as part of ISCCP.

  2. Lost in Cloud

    NASA Technical Reports Server (NTRS)

    Maluf, David A.; Shetye, Sandeep D.; Chilukuri, Sri; Sturken, Ian

    2012-01-01

    Cloud computing can reduce cost significantly because businesses can share computing resources. In recent years Small and Medium Businesses (SMB) have used Cloud effectively for cost saving and for sharing IT expenses. With the success of SMBs, many perceive that the larger enterprises ought to move into Cloud environment as well. Government agency s stove-piped environments are being considered as candidates for potential use of Cloud either as an enterprise entity or pockets of small communities. Cloud Computing is the delivery of computing as a service rather than as a product, whereby shared resources, software, and information are provided to computers and other devices as a utility over a network. Underneath the offered services, there exists a modern infrastructure cost of which is often spread across its services or its investors. As NASA is considered as an Enterprise class organization, like other enterprises, a shift has been occurring in perceiving its IT services as candidates for Cloud services. This paper discusses market trends in cloud computing from an enterprise angle and then addresses the topic of Cloud Computing for NASA in two possible forms. First, in the form of a public Cloud to support it as an enterprise, as well as to share it with the commercial and public at large. Second, as a private Cloud wherein the infrastructure is operated solely for NASA, whether managed internally or by a third-party and hosted internally or externally. The paper addresses the strengths and weaknesses of both paradigms of public and private Clouds, in both internally and externally operated settings. The content of the paper is from a NASA perspective but is applicable to any large enterprise with thousands of employees and contractors.

  3. Reflected Brownian Motion on an Orthant

    Microsoft Academic Search

    J. Michael Harrison; Martin I. Reiman

    1981-01-01

    We consider a $K$-dimensional diffusion process $Z$ whose state space is the nonnegative orthant. On the interior of the orthant, $Z$ behaves like a $K$-dimensional Brownian motion with arbitrary covariance matrix and drift vector. At each of the (`K-1) dimensional hyperplanes that form the boundary of the orthant, $Z$ reflects instantaneously in a direction that is constant over that hyperplane.

  4. Nonlinear motion analysis of flexible satellites

    NASA Technical Reports Server (NTRS)

    Huang, T. C.; Das, A.

    1976-01-01

    The article reviews research on pointing accuracies of flexible satellites with regard to derived equations of motion of individual elements and composite bodies. The solution of these equations may be achieved through the formulation of a set of singularly perturbed equations by eliminating the generalized position vector. These equations are generally solved by a method of asymptotic expansions if certain convergence criteria are satisfied. The analysis may be applied to dual-spin flexible satellites.

  5. Mab's orbital motion explained

    NASA Astrophysics Data System (ADS)

    Kumar, K.; de Pater, I.; Showalter, M. R.

    2015-07-01

    We explored the hypothesis that Mab's anomalous orbital motion, as deduced from Hubble Space Telescope (HST) data (Showalter, M.R., Lissauer, J.J. [2006]. Science (New York, NY) 311, 973-977), is the result of gravitational interactions with a putative suite of large bodies in the ?-ring. We conducted simulations to compute the gravitational effect of Mab (a recently discovered Uranian moon) on a cloud of test particles. Subsequently, by employing the data extracted from the test particle simulations, we executed random walk simulations to compute the back-reaction of nearby perturbers on Mab. By generating simulated observation metrics, we compared our results to the data retrieved from the HST. Our results indicate that the longitude residual change noted in the HST data (??r,Mab ? 1 deg) is well matched by our simulations. The eccentricity variations (?eMab ?10-3) are however typically two orders of magnitude too small. We present a variety of reasons that could account for this discrepancy. The nominal scenario that we investigated assumes a perturber ring mass (mring) of 1 mMab (Mab's mass) and a perturber ring number density (?n,ring) of 10 perturbers per 3 RHill,Mab (Mab's Hill radius). This effectively translates to a few tens of perturbers with radii of approximately 2-3 km, depending on the albedo assumed. The results obtained also include an interesting litmus test: variations of Mab's inclination on the order of the eccentricity changes should be observable. Our work provides clues for further investigation into the tantalizing prospect that the Mab/?-ring system is undergoing re-accretion after a recent catastrophic disruption.

  6. Markerless Motion Capture Developers/ Programmers/ Computer Vision Research Engineers Wanted

    E-print Network

    Plotkin, Joshua B.

    be beneficial. - Experience in leveraging cloud computing. Person Profile: - Self-motivated, diligent and detailMarkerless Motion Capture Developers/ Programmers/ Computer Vision Research Engineers Wanted Kina for qualified Computer Vision Research Engineers to come work with our diverse R&D team, to advance our state

  7. 3D motion estimation of atmospheric layers from image sequences

    E-print Network

    Paris-Sud XI, Université de

    of satellite images and we believe that it is very important that the computer vision community gets involved the problem of esti- mating three-dimensional motions of a stratified atmosphere from satellite image of atmospheric layers due to the sparsity of cloud systems is very difficult. This makes the estimation of dense

  8. On the origin of the Orion and Monoceros molecular cloud complexes

    NASA Technical Reports Server (NTRS)

    Franco, J.; Tenorio-Tagle, G.; Bodenheimer, P.; Rozyczka, M.; Mirabel, I. F.

    1988-01-01

    A detailed model for the origin of the Orion and Monoceros cloud complexes is presented, showing that a single high-velocity H I cloud-galaxy collision can explain their main observed features. The collision generates massive shocked layers, and self-gravity can then provide the conditions for the transformation of these layers into molecular clouds. The clouds formed by the collision maintain the motion of their parental shocked gas and reach positions located far away from the plane. According to this model, both the Orion and Monoceros complexes were formed some 60 million yr ago, when the original shocked layer was fragmented by Galactic tidal forces.

  9. Relationship between cloud radiative forcing, cloud fraction and cloud albedo, and new surface-based approach for determining cloud albedo

    SciTech Connect

    Liu, Y.; Wu, W.; Jensen, M. P.; Toto, T.

    2011-07-21

    This paper focuses on three interconnected topics: (1) quantitative relationship between surface shortwave cloud radiative forcing, cloud fraction, and cloud albedo; (2) surface-based approach for measuring cloud albedo; (3) multiscale (diurnal, annual and inter-annual) variations and covariations of surface shortwave cloud radiative forcing, cloud fraction, and cloud albedo. An analytical expression is first derived to quantify the relationship between cloud radiative forcing, cloud fraction, and cloud albedo. The analytical expression is then used to deduce a new approach for inferring cloud albedo from concurrent surface-based measurements of downwelling surface shortwave radiation and cloud fraction. High-resolution decade-long data on cloud albedos are obtained by use of this surface-based approach over the US Department of Energy's Atmospheric Radiaton Measurement (ARM) Program at the Great Southern Plains (SGP) site. The surface-based cloud albedos are further compared against those derived from the coincident GOES satellite measurements. The three long-term (1997-2009) sets of hourly data on shortwave cloud radiative forcing, cloud fraction and cloud albedo collected over the SGP site are analyzed to explore the multiscale (diurnal, annual and inter-annual) variations and covariations. The analytical formulation is useful for diagnosing deficiencies of cloud-radiation parameterizations in climate models.

  10. MPLNET Version 3 Cloud Algorithm

    NASA Astrophysics Data System (ADS)

    Lewis, J. R.; Campbell, J. R.; Welton, E. J.

    2013-12-01

    The Micropulse Lidar Network version 3 cloud detection algorithm is described. Differences between the new cloud algorithm and the previous version are highlighted. The algortihm uses thresholds in the derivative of the attenuated calibration profile to identify low-level clouds and the signal uncertainty to identify higher clouds. Cirrus clouds are identified using the cloud top temperature derived from NCEP reanalysis. To demonstrate the performance of the new algorithm, a multiyear vertical distribution of clouds is shown from measurements at the Goddard Space Flight Center (Greenbelt, MD) and Singapore sites. Seasonal and diurnal statistics on the cloud base, apparent top, temperature, phase, optical thinkness, and frequency of occurrence are featured.

  11. Hierarchal scalar and vector tetrahedra

    Microsoft Academic Search

    J. P. Webb; B. Forgahani

    1993-01-01

    A novel set of scalar and vector tetrahedral finite elements are presented. The elements are hierarchical, allowing mixing of polynomial orders. Scalar orders up to three and vector orders up to two are defined. The vector elements impose tangential continuity on the field but not normal continuity, making them suitable for representing the vector electric or magnetic field. The scalar

  12. Weather Fundamentals: Clouds. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) discusses how clouds form, the different types of clouds, and the important role they play in…

  13. Chemical cloud tracking systems

    Microsoft Academic Search

    Larry B. Grim; Thomas C. Gruber; Martin Marshall; Brad Rowland

    2002-01-01

    This paper describes the Chemical Cloud Tracking System (CCTS) which has been installed at Dugway Proving Ground. The CCTS allows mapping of chemical clouds in real time from a safe standoff distance. The instruments used are passive standoff chemical agent detectors (FTIRs). Each instrument individually can only measure the total of all the chemical in its line-of-site; the distance to

  14. Cloud Physics: The Basics

    NSDL National Science Digital Library

    Klatt, Michael L.

    This website from the Oklahoma Weather Modification Program encourages students to initiate a debate on the controversy surrounding the issue of inducing or enhancing precipitation. The exercise describes the two basic tenets of cloud seeding: the Static Phase Hypothesis and the Dynamic Phase Hypothesis. Also provided are links to a weather and climate glossary and further information about clouds and precipitation.

  15. XSEDE Cloud Survey Report

    E-print Network

    Walter, M.Todd

    XSEDE Cloud Survey Report David Lifka, Cornell Center for Advanced Computing Ian Foster, ANL Data 126 Cloud Investigation by Research Computing Services 128 Appendix 128 Acronyms 129 Terminology and The University of Chicago Susan Mehringer, Cornell Center for Advanced Computing Manish Parashar, Rutgers

  16. Clues About Clouds

    NSDL National Science Digital Library

    2012-06-26

    In this weather activity which requires adult supervision, learners will get a chance to make a cloud right here on Earth! They learn about the different ingredients a cloud needs in order to form, and then duplicate the process that usually takes place thousands of feet above their heads.

  17. Canopy In The Clouds

    NSDL National Science Digital Library

    Canopy In The Clouds is a free educational research focused on providing innovative and immersive earth and life science educational media from the perspective of a tropical montane clouds forest. All information on the website is peer-reviewed for accuracy and continually updated.

  18. The Stories Clouds Tell

    NSDL National Science Digital Library

    Margaret Lemone

    2005-03-10

    This book is a basic guide to the study of clouds. It features descriptions, photographs, and diagrams of various types of clouds. The book is accompanied by a set of slides. It was produced as part of Project ATMOSPHERE, an educational initiative of the American Meteorological Society.

  19. On Cloud Nine

    ERIC Educational Resources Information Center

    McCrea, Bridget; Weil, Marty

    2011-01-01

    Across the U.S., innovative collaboration practices are happening in the cloud: Sixth-graders participate in literary salons. Fourth-graders mentor kindergarteners. And teachers use virtual Post-it notes to advise students as they create their own television shows. In other words, cloud computing is no longer just used to manage administrative…

  20. ISCCP Global Cloud Cover

    NSDL National Science Digital Library

    Dave Pape

    1994-03-13

    This animated sequence is a one month sample of composited images from cloud cover data collected from a suite of U.S., European, and Japanese geostationary satellites and U.S. polar orbiting meteorological satellites. This data was composited under the auspices of ISCCP, the International Satellite Cloud Climatology Program.

  1. The microphysics of clouds

    Microsoft Academic Search

    B J Mason; F H Ludlam

    1951-01-01

    The results of recent research into the microphysical processes involved in the formation of clouds and precipitation are described and assessed.While the rate of spontaneous nucleation in water vapour is inappreciable until the supersaturation reaches about 400%, the presence of foreign nuclei in the atmosphere allows cloud formation with supersaturations of only about 0·1%. The mode of action, nature and

  2. Learning in the Clouds?

    ERIC Educational Resources Information Center

    Butin, Dan W.

    2013-01-01

    Engaged learning--the type that happens outside textbooks and beyond the four walls of the classroom--moves beyond right and wrong answers to grappling with the uncertainties and contradictions of a complex world. iPhones back up to the "cloud." GoogleDocs is all about "cloud computing." Facebook is as ubiquitous as the sky.…

  3. Cloud Resolving Modeling

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2007-01-01

    One of the most promising methods to test the representation of cloud processes used in climate models is to use observations together with cloud-resolving models (CRMs). CRMs use more sophisticated and realistic representations of cloud microphysical processes, and they can reasonably well resolve the time evolution, structure, and life cycles of clouds and cloud systems (with sizes ranging from about 2-200 km). CRMs also allow for explicit interaction between clouds, outgoing longwave (cooling) and incoming solar (heating) radiation, and ocean and land surface processes. Observations are required to initialize CRMs and to validate their results. This paper provides a brief discussion and review of the main characteristics of CRMs as well as some of their major applications. These include the use of CRMs to improve our understanding of: (1) convective organization, (2) cloud temperature and water vapor budgets, and convective momentum transport, (3) diurnal variation of precipitation processes, (4) radiative-convective quasi-equilibrium states, (5) cloud-chemistry interaction, (6) aerosol-precipitation interaction, and (7) improving moist processes in large-scale models. In addition, current and future developments and applications of CRMs will be presented.

  4. SoundCloudNav

    NSDL National Science Digital Library

    2012-05-10

    For people who like to use SoundCloud to control their musical selections while working, this helpful plug-in will be a welcome find. SoundCloudNav will allow users to explore different tracks and manipulate them as they see fit. This version is compatible with all computers utilizing Google Chrome.

  5. GPS constraints on Africa (Nubia) and Arabia plate motions

    Microsoft Academic Search

    S. McClusky; R. Reilinger; S. Mahmoud; D. Ben Sari; A. Tealeb

    2003-01-01

    We use continuously recording GPS (CGPS) and survey-mode GPS (SGPS) observations to determine Euler vectors for relative motion of the African (Nubian), Arabian and Eurasian plates. We present a well-constrained Eurasia-Nubia Euler vector derived from 23 IGS sites in Europe and four CGPS and three SGPS sites on the Nubian Plate (-0.95 +\\/- 4.8°N, -21.8 +\\/- 4.3°E, 0.06 +\\/- 0.005°

  6. Prebiotic chemistry in clouds

    NASA Technical Reports Server (NTRS)

    Oberbeck, Verne R.; Marshall, John; Shen, Thomas

    1991-01-01

    The chemical evolution hypothesis of Woese (1979), according to which prebiotic reactions occurred rapidly in droplets in giant atmospheric reflux columns was criticized by Scherer (1985). This paper proposes a mechanism for prebiotic chemistry in clouds that answers Scherer's concerns and supports Woese's hypothesis. According to this mechanism, rapid prebiotic chemical evolution was facilitated on the primordial earth by cycles of condensation and evaporation of cloud drops containing clay condensation nuclei and nonvolatile monomers. For example, amino acids supplied by, or synthesized during entry of meteorites, comets, and interplanetary dust, would have been scavenged by cloud drops containing clay condensation nuclei and would be polymerized within cloud systems during cycles of condensation, freezing, melting, and evaporation of cloud drops.

  7. Cloud computing security.

    SciTech Connect

    Shin, Dongwan; Claycomb, William R.; Urias, Vincent E.

    2010-10-01

    Cloud computing is a paradigm rapidly being embraced by government and industry as a solution for cost-savings, scalability, and collaboration. While a multitude of applications and services are available commercially for cloud-based solutions, research in this area has yet to fully embrace the full spectrum of potential challenges facing cloud computing. This tutorial aims to provide researchers with a fundamental understanding of cloud computing, with the goals of identifying a broad range of potential research topics, and inspiring a new surge in research to address current issues. We will also discuss real implementations of research-oriented cloud computing systems for both academia and government, including configuration options, hardware issues, challenges, and solutions.

  8. Cloud Model Bat Algorithm

    PubMed Central

    Zhou, Yongquan; Xie, Jian; Li, Liangliang; Ma, Mingzhi

    2014-01-01

    Bat algorithm (BA) is a novel stochastic global optimization algorithm. Cloud model is an effective tool in transforming between qualitative concepts and their quantitative representation. Based on the bat echolocation mechanism and excellent characteristics of cloud model on uncertainty knowledge representation, a new cloud model bat algorithm (CBA) is proposed. This paper focuses on remodeling echolocation model based on living and preying characteristics of bats, utilizing the transformation theory of cloud model to depict the qualitative concept: “bats approach their prey.” Furthermore, Lévy flight mode and population information communication mechanism of bats are introduced to balance the advantage between exploration and exploitation. The simulation results show that the cloud model bat algorithm has good performance on functions optimization. PMID:24967425

  9. July 2012July 2012 Cloud Computing and Virtualization:Cloud Computing and Virtualization

    E-print Network

    Liu, Jiangchuan (JC)

    July 2012July 2012 Cloud Computing and Virtualization:Cloud Computing and Virtualization/26/2633 Recent: CloudRecent: Cloud The fast growth of cloud computing Cloud file storage/synchronization services Google entries about cloud computing: 184,000,000 #12;July 2012July 2012 44/26/2644 Our CloudOur Cloud 7

  10. Precipitation growth in convective clouds. [hail

    NASA Technical Reports Server (NTRS)

    Srivastava, R. C.

    1981-01-01

    Analytical solutions to the equations of both the growth and motion of hailstones in updrafts and of cloud water contents which vary linearly with height were used to investigate hail growth in a model cloud. A strong correlation was found between the hail embyro starting position and its trajectory and final size. A simple model of the evolution of particle size distribution by coalescence and spontaneous and binary disintegrations was formulated. Solutions for the mean mass of the distribution and the equilibrium size distribution were obtained for the case of constant collection kernel and disintegration parameters. Azimuthal scans of Doppler velocity at a number of elevation angles were used to calculate high resolution vertical profiles of particle speed and horizontal divergence (the vertical air velocity) in a region of widespread precipitation trailing a mid-latitude squall line.

  11. Secure Computation of Top-K Eigenvectors for Shared Matrices in the Cloud James Powers, Keke Chen

    E-print Network

    Computing (Kno.e.sis) Department of Computer Science and Engineering, Wright State University {powers.4,keke.chen}@wright. Keywords-cloud computing, big matrix, power iteration, MapReduce, security, performance I. INTRODUCTION submit data vectors (e.g., a vector describing the users interactions in a social network service

  12. Dynamical processes atop penetrative tropical deep convective clouds

    NASA Astrophysics Data System (ADS)

    Wang, P. K.

    2009-12-01

    Deep convective clouds in the tropics play an important role in transporting momentum and water vapor into the stratosphere. The gravity waves generated by these clouds are thought to have significant contribution to the QBO phenomenon. They may also contribute to the water vapor in the stratosphere. Yet it is still unclear about how these processes occur, primarily due to the difficulties in observation owing to the high altitude nature of the cloud top. In this study, we perform a high resolution 3-D non-hydrostatic cloud model study to understand these processes. The horizontal and vertical resolutions are 1 km and 0.2 km respectively. A simplified but representative tropical sounding with a cold point tropopause at 17 km is used for this simulation study. The results show that the gravity waves have strong influence on the morphology of the cloud top and multiple anvil layers form as a result of wave motions. The top part of the cloud appears to become dissociated with the main body due to instability and is injected high into the stratosphere. Photographs taken from aircraft flying near some tropical cumulonimbus show close resemblance of the cloud top morphology produced by the model. The dynamical processes as revealed by the model results can also explain the “cold ring” feature in some satellite infrared images of deep convective storms. We believe that these processes play an important role in the cross-tropopause transport processes.

  13. Moving Glass patterns: asymmetric interaction between motion and form.

    PubMed

    Or, Charles C-F; Khuu, Sieu K; Hayes, Anthony

    2010-01-01

    The perceived motion direction of a moving Glass pattern is influenced by the orientation of the dot pairs (dipoles) that generate the pattern (Krekelberg et al, 2003 Nature 424 674-677; Ross, 2004 Vision Research 44 441-448). Here, we investigate how the motion vector and the dipole orientation of moving Glass patterns influence the perceived orientation of each. We employed 1 s movie presentations of sequences of linear Glass patterns, each consisting of 200 dot pairs. Signal pairs, aligned in a common orientation, moved in a common direction. The observer's task was to indicate either the perceived direction of motion, or the perceived dipole orientation of Glass patterns that consisted of either same-polarity dipoles, or opposite-polarity dipoles. Perceived orientation or motion direction was measured as a function of the angular difference between the orientation and the motion direction of the dipoles. We found that the apparent global direction of motion was attracted by approximately 4 degrees towards the dipole orientation for small (15 degrees, 23 degrees) angular differences between dipole motion-direction and dipole orientation, regardless of dipole polarity. However, under the same stimulus conditions, the apparent global orientation was much less affected by the direction of motion, suggesting that motion and form interact asymmetrically Global form influences global motion-direction perception more powerfully than global motion influences global form perception. PMID:20514995

  14. Cloud Condensation Nuclei Retrievals at Cloud Base in North Dakota

    E-print Network

    Delene, David J.

    accuracy #12;POLCAST4 Polarimetric Cloud Analysis and Seeding Test 4 Field campaign held in the summerCloud Condensation Nuclei Retrievals at Cloud Base in North Dakota · Mariusz Starzec #12;Motivation Compare University of Wyoming (UWyo) and Droplet Measurement Technologies (DMT) cloud condensation nuclei

  15. Twin Clouds: An Architecture for Secure Cloud Computing (Extended Abstract)

    E-print Network

    Cachin, Christian

    Twin Clouds: An Architecture for Secure Cloud Computing (Extended Abstract) Sven Bugiel1 , Stefan N System Security Lab, Ruhr-University Bochum, Germany thomas.schneider@trust.rub.de Abstract. Cloud cloud or built from multiple secure hardware modules) which encrypts and verifies the data stored

  16. When Clouds become Green: the Green Open Cloud Architecture

    E-print Network

    Boyer, Edmond

    of a new original energy-efficient Cloud infrastructure called Green Open Cloud. Keywords. EnergyWhen Clouds become Green: the Green Open Cloud Architecture Anne-Cécile ORGERIE a and Laurent their operational services on a physical infrastructure, while pre- serving specific functionalities inside

  17. Vectorized garbage collection

    SciTech Connect

    Appel, A.W.; Bendiksen, A.

    1988-01-01

    Garbage collection can be done in vector mode on supercomputers like the Cray-2 and the Cyber 205. Both copying collection and mark-and-sweep can be expressed as breadth-first searches in which the queue can be processed in parallel. The authors have designed a copying garbage collector whose inner loop works entirely in vector mode. The only significant limitation of the algorithm is that if the size of the records is not constant, the implementation becomes much more complicated. The authors give performance measurements of the algorithm as implemented for Lisp CONS cells on the Cyber 205. Vector-mode garbage collection performs up to 9 times faster than scalar-mode collection.

  18. Fragmentation and Collapse of Turbulent Molecular Clouds

    NASA Astrophysics Data System (ADS)

    Tilley, D.; Pudritz, R.; Wadsley, J.

    A deeper understanding of how stars form within a molecular cloud cannot be achieved without first understanding their environment. A strong candidate for a theory of the formation and evolution of the host filaments and cores in which the protostellar objects are embedded is the idea that these structures are formed through the fragmentation of the molecular cloud through turbulent motions. We present results from numerical simulations of freely decaying self-gravitating hydromagnetic turbulence, with the goal of studying the individual structures which are produced in such a turbulent fragmentation scenario. Our simulations are performed in three dimensions with periodic boundary conditions, using the ZEUS-MP code. We set up an initial turbulent velocity field with an isothermal equation of state, and an initially uniform density and magnetic field. The simulations were performed on the SHARCNet supercomputing facility at McMaster University, supplemented by an 8-processor Beowulf cluster. Our initial hydrodynamic results suggest that if the cloud has enough mass to fragment before the turbulent energies are dampened, so that the computational grid contains at least 3-5 Jeans masses, then the turbulence can provide additional support to the individual cores, resulting in density profiles of r-1 -- r-1.5, which is shallower than the hydrostatic equilibrium solution of r-2. However, if the gravitational forces are weak (such as a simulation with only 1 Jeans mass), the gravitational structures do not form until after the turbulence has decayed significantly, and as a result adopts the Bonnor-Ebert density structure, which is expected for a system with primarily thermal pressure support. We extend these results to include hydromagnetic effects on the fluid motions. The presence of a magnetic field has been shown to have important consequences in slowing down the rate of decay of turbulence (Cho, Lazarian & Vishniac 2002), and in determining the structure seen in polarimetry maps of molecular clouds (Fiege & Pudritz 2000).

  19. Redundancy, Self-Motion, and Motor Control

    PubMed Central

    Martin, V.; Scholz, J. P.; Schöner, G.

    2011-01-01

    Outside the laboratory, human movement typically involves redundant effector systems. How the nervous system selects among the task-equivalent solutions may provide insights into how movement is controlled. We propose a process model of movement generation that accounts for the kinematics of goal-directed pointing movements performed with a redundant arm. The key element is a neuronal dynamics that generates a virtual joint trajectory. This dynamics receives input from a neuronal timer that paces end-effector motion along its path. Within this dynamics, virtual joint velocity vectors that move the end effector are dynamically decoupled from velocity vectors that do not. Moreover, the sensed real joint configuration is coupled back into this neuronal dynamics, updating the virtual trajectory so that it yields to task-equivalent deviations from the dynamic movement plan. Experimental data from participants who perform in the same task setting as the model are compared in detail to the model predictions. We discover that joint velocities contain a substantial amount of self-motion that does not move the end effector. This is caused by the low impedance of muscle joint systems and by coupling among muscle joint systems due to multiarticulatory muscles. Back-coupling amplifies the induced control errors. We establish a link between the amount of self-motion and how curved the end-effector path is. We show that models in which an inverse dynamics cancels interaction torques predict too little self-motion and too straight end-effector paths. PMID:19718817

  20. A boundary property of semimartingale reflecting Brownian motions

    Microsoft Academic Search

    M. I. Reiman; R. J. Williams

    1988-01-01

    Summary We consider a class of reflecting Brownian motions on the non-negative orthant inRK. In the interior of the orthant, such a process behaves like Brownian motion with a constant covariance matrix and drift vector. At each of the (K-1)-dimensional faces that form the boundary of the orthant, the process reflects instantaneously in a direction that is constant over the

  1. Open architecture television for motion-compensated coding

    NASA Astrophysics Data System (ADS)

    Bove, V. Michael, Jr.; Chalom, Edmond

    1992-11-01

    Open Architecture Television centers on the development of digital image representations that allow video to be displayed at resolutions and frame rates that do not necessarily match the numerical parameters of the camera. We begin an investigation of frame-rate conversion in the reconstruction of motion-compensated image sequences, and suggest a simple change in the generation of the motion vectors which enhances the quality of the images produced.

  2. UNCORRECTED 2 Illusory rebound motion and the motion continuity heuristic

    E-print Network

    Bucci, David J.

    UNCORRECTED PROOF 2 Illusory rebound motion and the motion continuity heuristic 3 P.-J. Hsieh, G Abstract 8 A new motion illusion, ``illusory rebound motion'' (IRM), is described. IRM is a variant Published by Elsevier Ltd. 16 Keywords: Illusory rebound motion; Illusory line motion; Attention; Motion

  3. Diagnosing AIRS Sampling with CloudSat Cloud Classes

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric; Yue, Qing; Guillaume, Alexandre; Kahn, Brian

    2011-01-01

    AIRS yield and sampling vary with cloud state. Careful utilization of collocated multiple satellite sensors is necessary. Profile differences between AIRS and ECMWF model analyses indicate that AIRS has high sampling and excellent accuracy for certain meteorological conditions. Cloud-dependent sampling biases may have large impact on AIRS L2 and L3 data in climate research. MBL clouds / lower tropospheric stability relationship is one example. AIRS and CloudSat reveal a reasonable climatology in the MBL cloud regime despite limited sampling in stratocumulus. Thermodynamic parameters such as EIS derived from AIRS data map these cloud conditions successfully. We are working on characterizing AIRS scenes with mixed cloud types.

  4. On helical vortex motions of moist air

    NASA Astrophysics Data System (ADS)

    Kurgansky, M. V.

    2013-09-01

    Two results that are fundamentally different from what takes place in a dry atmosphere have been obtained for adiabatic motions of unsaturated moist air: (1) the steady helical motion of moist air with collinear velocity and vorticity vectors everywhere is dynamically impossible; (2) the spontaneous amplification (generation) of helicity in a moist air due to baroclinicity is dynamically and thermodynamically feasible. In the absence of helicity flux through the boundary of the domain occupied by air flows, the difference between the values of integral helicity H at time instant t delaying at a small time interval from the initial instant t 0 (at which the instantaneous state of air motion is isomorphic either to a steady Beltrami flow or to an irrotational flow) and the initial value of H increases proportionally to ( t - t 0)4. The nonzero value of the proportionality factor is ensured by the difference in values of the Poisson ratio for dry air and water vapor, respectively.

  5. Field signature for apparently superluminal particle motion

    NASA Astrophysics Data System (ADS)

    Land, Martin

    2015-05-01

    In the context of Stueckelberg's covariant symplectic mechanics, Horwitz and Aharonovich [1] have proposed a simple mechanism by which a particle traveling below light speed almost everywhere may exhibit a transit time that suggests superluminal motion. This mechanism, which requires precise measurement of the particle velocity, involves a subtle perturbation affecting the particle's recorded time coordinate caused by virtual pair processes. The Stueckelberg framework is particularly well suited to such problems, because it permits pair creation/annihilation at the classical level. In this paper, we study a trajectory of the type proposed by Horwitz and Aharonovich, and derive the Maxwell 4-vector potential associated with the motion. We show that the resulting fields carry a signature associated with the apparent superluminal motion, providing an independent test for the mechanism that does not require direct observation of the trajectory, except at the detector.

  6. Redshifts and Killing Vectors

    E-print Network

    Alex Harvey; Engelbert L. Schucking; Eugene J. Surowitz

    2005-08-31

    Courses in introductory special and general relativity have increasingly become part of the curriculum for upper-level undergraduate physics majors and master's degree candidates. One of the topics rarely discussed is symmetry, particularly in the theory of general relativity. The principal tool for its study is the Killing vector. We provide an elementary introduction to the concept of a Killing vector field, its properties, and as an example of its utility apply these ideas to the rigorous determination of gravitational and cosmological redshifts.

  7. Cloud Formation: A Cloud in a Bottle

    NSDL National Science Digital Library

    Melissa Lombardoni

    This activity is designed to be used as either a teacher demonstration or a laboratory activity as part of a weather unit. It reinforces the concepts of condensation, dew point, humidity, pressure, condensation nuclei, and the process of cloud formation. The site has a list of required materials, detailed instructions, questions for the students, and links to other weather-related sites.

  8. Isentropic Analysis of Convective Motions

    NASA Technical Reports Server (NTRS)

    Pauluis, Olivier M.; Mrowiec, Agnieszka A.

    2013-01-01

    This paper analyzes the convective mass transport by sorting air parcels in terms of their equivalent potential temperature to determine an isentropic streamfunction. By averaging the vertical mass flux at a constant value of the equivalent potential temperature, one can compute an isentropic mass transport that filters out reversible oscillatory motions such as gravity waves. This novel approach emphasizes the fact that the vertical energy and entropy transports by convection are due to the combination of ascending air parcels with high energy and entropy and subsiding air parcels with lower energy and entropy. Such conditional averaging can be extended to other dynamic and thermodynamic variables such as vertical velocity, temperature, or relative humidity to obtain a comprehensive description of convective motions. It is also shown how this approach can be used to determine the mean diabatic tendencies from the three-dimensional dynamic and thermodynamic fields. A two-stream approximation that partitions the isentropic circulation into a mean updraft and a mean downdraft is also introduced. This offers a straightforward way to identify the mean properties of rising and subsiding air parcels. The results from the two-stream approximation are compared with two other definitions of the cloud mass flux. It is argued that the isentropic analysis offers a robust definition of the convective mass transport that is not tainted by the need to arbitrarily distinguish between convection and its environment, and that separates the irreversible convective overturning fromoscillations associated with gravity waves.

  9. Research Article Motion Detection and Motion

    E-print Network

    Vigliocco, Gabriella

    analysis revealed that when verbs were directionally in- congruent with the motion signal, perceptual to a particular modal event should influence perceptual processing of that event, as comprehension and perception went up,'' ``the car approached you''). During this comprehension task, subjects viewed motion

  10. Motion Lab: Position - Time Graphs of Motion

    NSDL National Science Digital Library

    John M. Clement

    The representation depicts a position-time graph showing the motion of an object as it is moved by the user. The user can also move the object to match the motion represented on 8 different types of position-time graphs.

  11. Community Cloud Computing

    NASA Astrophysics Data System (ADS)

    Marinos, Alexandros; Briscoe, Gerard

    Cloud Computing is rising fast, with its data centres growing at an unprecedented rate. However, this has come with concerns over privacy, efficiency at the expense of resilience, and environmental sustainability, because of the dependence on Cloud vendors such as Google, Amazon and Microsoft. Our response is an alternative model for the Cloud conceptualisation, providing a paradigm for Clouds in the community, utilising networked personal computers for liberation from the centralised vendor model. Community Cloud Computing (C3) offers an alternative architecture, created by combing the Cloud with paradigms from Grid Computing, principles from Digital Ecosystems, and sustainability from Green Computing, while remaining true to the original vision of the Internet. It is more technically challenging than Cloud Computing, having to deal with distributed computing issues, including heterogeneous nodes, varying quality of service, and additional security constraints. However, these are not insurmountable challenges, and with the need to retain control over our digital lives and the potential environmental consequences, it is a challenge we must pursue.

  12. The effect of carrier gas pressure on vapor phase nucleation experiments using a thermal diffusion cloud chamber

    Microsoft Academic Search

    D. Kane; S. P. Fisenko; M. Rusyniak; M. S. El-Shall

    1999-01-01

    Recent measurements of critical supersaturations for the vapor phase homogeneous nucleation of several substances using a diffusion cloud chamber technique exhibit a dependence on the pressure of the carrier gas used in the experiments. A model of droplet growth and motion in a diffusion cloud chamber, combined with the density and temperature profiles of the chamber is presented to explain

  13. A General Contact Model for Dynamically-Decoupled Force\\/Motion Control

    Microsoft Academic Search

    Roy Featherstone; Stef Sonck Thiebaut; Oussama Khatib

    1999-01-01

    This paper presents a general first-order kinematic model of frictionless rigid-body contact for use in hy- brid force\\/motion control. It is formulated in an in- variant manner by treating motion and force vectors as members of two separate but dual vector spaces. These more general kinematics allow us to model tasks that cannot be described using the Raibert-Craig model; a

  14. Molecular clouds toward the super star cluster NGC 3603; possible evidence for a cloud-cloud collision in triggering the cluster formation

    SciTech Connect

    Fukui, Y.; Ohama, A.; Hanaoka, N.; Furukawa, N.; Torii, K.; Hasegawa, K.; Fukuda, T.; Soga, S.; Moribe, N.; Kuroda, Y.; Hayakawa, T.; Kuwahara, T.; Yamamoto, H.; Okuda, T. [Department of Astrophysics, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan); Dawson, J. R. [School of Mathematics and Physics, University of Tasmania, Sandy Bay Campus, Churchill Avenue, Sandy Bay, TAS 7005 (Australia); Mizuno, N.; Kawamura, A. [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Onishi, T.; Maezawa, H. [Department of Astrophysics, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531 (Japan); Mizuno, A., E-mail: fukui@a.phys.nagoya-u.ac.jp [Solar-terrestrial Environment Laboratory, Nagoya University, Chikusa-ku, Nagoya 464-8601 (Japan)

    2014-01-01

    We present new large field observations of molecular clouds with NANTEN2 toward the super star cluster NGC 3603 in the transitions {sup 12}CO(J = 2-1, J = 1-0) and {sup 13}CO(J = 2-1, J = 1-0). We suggest that two molecular clouds at 13 km s{sup –1} and 28 km s{sup –1} are associated with NGC 3603 as evidenced by higher temperatures toward the H II region, as well as morphological correspondence. The mass of the clouds is too small to gravitationally bind them, given their relative motion of ?20 km s{sup –1}. We suggest that the two clouds collided with each other 1 Myr ago to trigger the formation of the super star cluster. This scenario is able to explain the origin of the highest mass stellar population in the cluster, which is as young as 1 Myr and is segregated within the central sub-pc of the cluster. This is the second super star cluster along with Westerlund 2 where formation may have been triggered by a cloud-cloud collision.

  15. Cloud security: myth or reality?

    Microsoft Academic Search

    Timothy G. Brown

    2011-01-01

    Can the cloud truly be secured? Can enterprises, universities, small businesses and governments securely utilize the cloud for their critical infrastructure? It will take rethinking our current security policies and what we consider secure. This session will cover what is necessary to utilize the cloud securely today and how the cloud should adapt for the future.

  16. Declarative Automated Cloud Resource Orchestration

    E-print Network

    Plotkin, Joshua B.

    InfrastructureasaService (IaaS) cloud computing is increasingly attractive 2 #12;To Build IaaS Cloud Cloud resourceDeclarative Automated Cloud Resource Orchestration 1 Changbin Liu, Boon Thau Loo, Yun Mao* 1 · Complex! ­ Large scale and distributed datacenters ­ Resources in wide diversity · Compute, storage

  17. CLOUD SERVICES CODE OF PRACTICE

    E-print Network

    Royal Holloway, University of London

    of this document, cloud storage can be defined as any storage solution which stores University information assetsCLOUD SERVICES RHUL CODE OF PRACTICE Document Id Cloud Services RHUL Code of Practice Sponsor Laura draft for review Document Approval Name Approval Signature Approval Date ITUAG #12;Cloud Services ­ RHUL

  18. Cloud computing basics for librarians.

    PubMed

    Hoy, Matthew B

    2012-01-01

    "Cloud computing" is the name for the recent trend of moving software and computing resources to an online, shared-service model. This article briefly defines cloud computing, discusses different models, explores the advantages and disadvantages, and describes some of the ways cloud computing can be used in libraries. Examples of cloud services are included at the end of the article. PMID:22289098

  19. Cloud Study Final Art Project

    NSDL National Science Digital Library

    Kim Toops

    This activity is an art project completed at the end of a study of weather and clouds. Using home-made puffy paint, the students paint clouds on a piece of construction paper and write 2-3 facts about each cloud type on a note card that is glued on construction paper next to the appropriate cloud.

  20. Counting the Clouds

    NASA Astrophysics Data System (ADS)

    Randall, David

    2007-03-01

    Cloud processes are very important for the global circulation of the atmosphere. It is now possible, though very expensive, to simulate the global circulation of the atmosphere using a model with resolution fine enough to explicitly represent the larger individual clouds. An impressive preliminary calculation of this type has already been performed by Japanese scientists, using the Earth Simulator. Within the next few years, such global cloud-resolving models (GCRMs) will be applied to weather prediction, and later they will be used in climate-change simulations. A ``multi-scale modeling framework'' can be used as a bridge between current low-resolution climate models and future GCRMs.

  1. Cloud Distribution Statistics from LITE

    NASA Technical Reports Server (NTRS)

    Winker, David M.

    1998-01-01

    The Lidar In-Space Technology Experiment (LITE) mission has demonstrated the utility of spaceborne lidar in observing multilayer clouds and has provided a dataset showing the distribution of tropospheric clouds and aerosols. These unambiguous observations of the vertical distribution of clouds will allow improved verification of current cloud climatologies and GCM cloud parameterizations. Although there is now great interest in cloud profiling radar, operating in the mm-wave region, for the spacebased observation of cloud heights the results of the LITE mission have shown that satellite lidars can also make significant contributions in this area.

  2. Revisiting the Seven Vectors.

    ERIC Educational Resources Information Center

    Reisser, Linda

    1995-01-01

    The second edition of "Education and Identity" (Chickering & Reisser, 1993), updating Chickering's 1969 theory, describes institutional influences and broad changes in students as they move through higher education. The seven revised vectors are summarized in this article, and current issues related to the updated theory are discussed. (JBJ)

  3. Killing vectors and anisotropy

    E-print Network

    J. P. Krisch; E. N. Glass

    2009-08-03

    We consider an action that can generate fluids with three unequal stresses for metrics with a spacelike Killing vector. The parameters in the action are directly related to the stress anisotropies. The field equations following from the action are applied to an anisotropic cosmological expansion and an extension of the Gott-Hiscock cosmic string.

  4. Killing vectors and anisotropy

    SciTech Connect

    Krisch, J. P.; Glass, E. N. [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2009-08-15

    We consider an action that can generate fluids with three unequal stresses for metrics with a spacelike Killing vector. The parameters in the action are directly related to the stress anisotropies. The field equations following from the action are applied to an anisotropic cosmological expansion and an extension of the Gott-Hiscock cosmic string.

  5. Singular Vectors' Subtle Secrets

    ERIC Educational Resources Information Center

    James, David; Lachance, Michael; Remski, Joan

    2011-01-01

    Social scientists use adjacency tables to discover influence networks within and among groups. Building on work by Moler and Morrison, we use ordered pairs from the components of the first and second singular vectors of adjacency matrices as tools to distinguish these groups and to identify particularly strong or weak individuals.

  6. Support vector machines

    NASA Technical Reports Server (NTRS)

    Garay, Michael J.; Mazzoni, Dominic; Davies, Roger; Wagstaff, Kiri

    2004-01-01

    Support Vector Machines (SVMs) are a type of supervised learning algorith,, other examples of which are Artificial Neural Networks (ANNs), Decision Trees, and Naive Bayesian Classifiers. Supervised learning algorithms are used to classify objects labled by a 'supervisor' - typically a human 'expert.'.

  7. Vectors Point Toward Pisa

    ERIC Educational Resources Information Center

    Dean, Richard A.

    1971-01-01

    The author shows that the set of all sequences in which each term is the sum of the two previous terms forms a vector space of dimension two. He uses this result to obtain the formula for the Fibonacci sequence and applies the same technique to other linear recursive relations. (MM)

  8. Vector Autoregressions and Reality

    Microsoft Academic Search

    David E. Runkle

    1987-01-01

    This article questions the statistical significance of variance decompositions and impulse response functions for unrestricted vector autoregressions. It suggests that previous authors have failed to provide confidence intervals for variance decompositions and impulse response functions. Two methods of computing such confidence intervals are developed: first, using a normal approximation; second, using bootstrapped resampling. An example from Sims's work is used

  9. Integrated video motion estimator with Retinex-like pre-processing for robust motion analysis in automotive scenarios: algorithmic and real-time architecture design

    Microsoft Academic Search

    Stefano Marsi; Sergio Saponara

    2010-01-01

    The paper presents a novel technique for robust motion analysis in real automotive scenarios based on integrated Retinex-like\\u000a pre-processing algorithm with block matching video motion estimator. Both algorithmic and real-time hardware design issues\\u000a are discussed. The benefits of the proposed technique are manifold: the entire system is more robust; the estimated motion\\u000a vectors are more reliable and less dependent on

  10. Activity recognition using a mixture of vector fields.

    PubMed

    Nascimento, Jacinto C; Figueiredo, Mário A T; Marques, Jorge S

    2013-05-01

    The analysis of moving objects in image sequences (video) has been one of the major themes in computer vision. In this paper, we focus on video-surveillance tasks; more specifically, we consider pedestrian trajectories and propose modeling them through a small set of motion/vector fields together with a space-varying switching mechanism. Despite the diversity of motion patterns that can occur in a given scene, we show that it is often possible to find a relatively small number of typical behaviors, and model each of these behaviors by a "simple" motion field. We increase the expressiveness of the formulation by allowing the trajectories to switch from one motion field to another, in a space-dependent manner. We present an expectation-maximization algorithm to learn all the parameters of the model, and apply it to trajectory classification tasks. Experiments with both synthetic and real data support the claims about the performance of the proposed approach. PMID:23193235

  11. Secure Cloud Computing With Brokered Trusted

    E-print Network

    Secure Cloud Computing With Brokered Trusted Sensor Networks Profs. Steven Myers,Apu Kapadia, Xiao External Storage External Storage Router Router Router Router Cloud Computing Cloud Computing Cloud Storage External Storage Router Router Router Router Cloud Computing Cloud Computing Cloud Computing Tower

  12. Service-Oriented Cloud Computing Architecture

    Microsoft Academic Search

    Wei-Tek Tsai; Xin Sun; Janaka Balasooriya

    2010-01-01

    Cloud computing is getting popular and IT giants such as Google, Amazon, Microsoft, IBM have started their cloud computing infrastructure. However, current cloud implementations are often isolated from other cloud implementations. This paper gives an overview survey of current cloud computing architectures, discusses issues that current cloud computing implementations have and proposes a Service-Oriented Cloud Computing Architecture (SOCCA) so that

  13. Motion Toward and Away

    NSDL National Science Digital Library

    2012-07-19

    Learn to differentiate between graphs of forward and backward motion. Predict what graphs look like before using a motion sensor, and then compare your predictions with real data. Respond to questions about several other position-time graphs and also explore position-time graphs that do not start at the origin (0,0). Motion Toward and Away is the second of five SmartGraphs activities designed for a typical physical science unit of study on the motion of objects.

  14. Recovering Fluid-type Motions Using Navier-Stokes Potential Flow Department of Computer and Information Sciences

    E-print Network

    Taufer, Michela

    maintains constant brightness across the frames. For fluid- type motions such as smoke or clouds as a surface, we use instead of I for consistency. and its movement is small, we have d dt = t + ( x , y such as clouds, ocean/river waves, and smoke. These natural phenomena do not satisfy the constant brightness

  15. Crowd motion capture

    Microsoft Academic Search

    Nicolas Courty; Thomas Corpetti

    2007-01-01

    In this paper a new and original technique to animate a crowd of human beings is presented. Following the success of data-driven animation models (such as motion capture) in the context of articulated figures control, we propose to derivate a similar type of approach for crowd motions. In our framework, the motion of the crowds are represented as a time

  16. Limited range of motion

    MedlinePLUS

    Limited range of motion is a term meaning that a joint or body part cannot move through its normal range of motion. ... A sudden loss of range of motion may be due to: Dislocation of a joint Fracture of an elbow or other joint Septic or infected ...

  17. Motion signal processing

    Microsoft Academic Search

    Armin Bruderlin; Lance Williams

    1995-01-01

    Techniques from the image and signal processing domain can be successfully applied to designing, modifying, and adapting ani- mated motion. For this purpose, we introduce multiresolution mo- tion filtering, multitarget motion interpolation with dynamic time- warping, waveshaping and motion displacement mapping. The techniques are well-suited for reuse and adaptation of existing mo- tion data such as joint angles, joint coordinates

  18. Modeling Human Motion Perception

    Microsoft Academic Search

    Johannes Zanker

    1994-01-01

    Motion perception is one of the most prominent tasks of the visual system and therefore has been extensively investigated both experimentally and theoretically. A classical model describing the mechanism of motion detection originally developed in the context of insect orientation behavior, the elementary motion detector (EMD) of the correlation type, turned out to be very powerful in explaining many basic

  19. Objects in Motion

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    One thing scientists study is how objects move. A famous scientist named Sir Isaac Newton (1642-1727) spent a lot of time observing objects in motion and came up with three laws that describe how things move. This explanation only deals with the first of his three laws of motion. Newton's First Law of Motion says that moving objects will continue…

  20. Modeling Sunspot Motion

    NSDL National Science Digital Library

    This is an activity about solar rotation and sunspot motion. Learners will use a sphere or ball to model the Sun and compare the observed lateral motion of sunspots to their line-of-sight motion. This is Activity 1 of the Space Weather Forecast curriculum.

  1. Cloud Computing For Microfinances

    E-print Network

    V, Suma; M, Vaidehi; Nair, T R Gopalakrishnan

    2012-01-01

    Evolution of Science and Engineering has led to the growth of several commercial applications. The wide spread implementation of commercial based applications has in turn directed the emergence of advanced technologies such as cloud computing. India has well proven itself as a potential hub for advanced technologies including cloud based industrial market. Microfinance system has emerged out as a panacea to Indian economy since the population encompasses of people who come under poverty and below poverty index. However, one of the key challenges in successful operation of microfinance system in India has given rise to integration of financial services using sophisticated cloud computing model. This paper, therefore propose a fundamental cloud-based microfinance model in order to reduce high transaction risks involved during microfinance operations in an inexpensive and efficient manner.

  2. NASA Cloud Albedo Animation

    NSDL National Science Digital Library

    NASA

    Clouds greatly affect the Earth's solar energy balance. This animation shows how they deflect a portion of solar energy influx from reaching our planet's surface and how they insulate to prevent a total loss of thermal radiance out into space.

  3. Methanol in dark clouds

    NASA Technical Reports Server (NTRS)

    Friberg, P.; Hjalmarson, A.; Madden, S. C.; Irvine, W. M.

    1988-01-01

    The first observation of methanol in cold dark clouds TMC 1, L 134 N, and B 335 is reported. In all three clouds, the relative abundance of methanol was found to be in the range of 10 to the -9th (i.e., almost an order of magnitude more abundant than acetaldehyde), with no observable variation between the clouds. Methanol emission showed a complex velocity structure; in TMC 1, clear indications of non-LTE were observed. Dimethyl ether was searched for in L 134 N; the upper limit of the column density of dimethyl ether in L 134 N was estimated to be 4 x 10 to the 12th/sq cm, assuming 5 K rotation temperature and LTE. This limit makes the abundance ratio (CH3)2O/CH3OH not higher than 1/5, indicating that dimethyl ether is not overabundant in this dark cloud.

  4. Comparison of magnetic helicity close to the sun and in magnetic clouds

    NASA Astrophysics Data System (ADS)

    Rust, D.

    Magnetic helicity is present in the solar atmosphere - as inferred from vector magnetograph measurements, solar filaments, S-shaped coronal structures known as sigmoids, and sunspot whorls. I will survey the possible solar sources of this magnetic helicity. Included are fieldline footpoint motions, effects of Coriolis forces, effects of convection, shear associated with differential rotation, and, of course, the internal dynamo. Besides the survey of possible local mechanisms for helicity generation, I will consider the global view of the flow of helicity from the sun into interplanetary space. The principal agents by which the sun sheds helicity are coronal mass ejections (CMEs). They are often associated with interplanetary magnetic clouds (MCs), whose fields are regularly probed with sensitive spacecraft magnetometers. MCs yield more direct measurements of helicity. They show that each MC carries helicity away from the sun. A major issue in solar-heliospheric research is whether the amount of helicity that MCs carry away in a solar cycle can be accounted for by the helicity generation mechanisms proposed so far. The NASA Solar and Heliospheric Physics Program supports this work under grants NAG5- 7921 and NAG 5-11584.

  5. Biview Learning for Human Posture Segmentation from 3D Points Cloud

    PubMed Central

    Qiao, Maoying; Cheng, Jun; Bian, Wei; Tao, Dacheng

    2014-01-01

    Posture segmentation plays an essential role in human motion analysis. The state-of-the-art method extracts sufficiently high-dimensional features from 3D depth images for each 3D point and learns an efficient body part classifier. However, high-dimensional features are memory-consuming and difficult to handle on large-scale training dataset. In this paper, we propose an efficient two-stage dimension reduction scheme, termed biview learning, to encode two independent views which are depth-difference features (DDF) and relative position features (RPF). Biview learning explores the complementary property of DDF and RPF, and uses two stages to learn a compact yet comprehensive low-dimensional feature space for posture segmentation. In the first stage, discriminative locality alignment (DLA) is applied to the high-dimensional DDF to learn a discriminative low-dimensional representation. In the second stage, canonical correlation analysis (CCA) is used to explore the complementary property of RPF and the dimensionality reduced DDF. Finally, we train a support vector machine (SVM) over the output of CCA. We carefully validate the effectiveness of DLA and CCA utilized in the two-stage scheme on our 3D human points cloud dataset. Experimental results show that the proposed biview learning scheme significantly outperforms the state-of-the-art method for human posture segmentation. PMID:24465721

  6. Biview learning for human posture segmentation from 3D points cloud.

    PubMed

    Qiao, Maoying; Cheng, Jun; Bian, Wei; Tao, Dacheng

    2014-01-01

    Posture segmentation plays an essential role in human motion analysis. The state-of-the-art method extracts sufficiently high-dimensional features from 3D depth images for each 3D point and learns an efficient body part classifier. However, high-dimensional features are memory-consuming and difficult to handle on large-scale training dataset. In this paper, we propose an efficient two-stage dimension reduction scheme, termed biview learning, to encode two independent views which are depth-difference features (DDF) and relative position features (RPF). Biview learning explores the complementary property of DDF and RPF, and uses two stages to learn a compact yet comprehensive low-dimensional feature space for posture segmentation. In the first stage, discriminative locality alignment (DLA) is applied to the high-dimensional DDF to learn a discriminative low-dimensional representation. In the second stage, canonical correlation analysis (CCA) is used to explore the complementary property of RPF and the dimensionality reduced DDF. Finally, we train a support vector machine (SVM) over the output of CCA. We carefully validate the effectiveness of DLA and CCA utilized in the two-stage scheme on our 3D human points cloud dataset. Experimental results show that the proposed biview learning scheme significantly outperforms the state-of-the-art method for human posture segmentation. PMID:24465721

  7. The collective gyration of a heavy ion cloud in a magnetized plasma

    NASA Technical Reports Server (NTRS)

    Brenning, N.; Swenson, C.; Kelley, M. C.; Providakes, J.; Torbert, R.

    1990-01-01

    In both the ionospheric barium injection experiments CRIT 1 and CRIT 2, a long duration oscillation was seen with a frequency close to the gyro frequency of barium and a time duration of about one second. A model for the phenomena which was proposed for the CRIT 1 experiment is compared to the results from CRIT 2 which made a much more complete set of measurements. The model follows the motion of a low Beta ion cloud through a larger ambient plasma. The internal field of the model is close to antiparallel to the injection direction v sub i but slightly tilted towards the self polarization direction E sub p = -V sub i by B. As the ions move across the magnetic field, the space charge is continuously neutralized by magnetic field aligned electron currents from the ambient ionosphere, drawn by the divergence in the perpendicular electric field. These currents give a perturbation of the magnetic field related to the electric field perturbation by Delta E/Delta B approximately equal to V sub A. The model predictions agree quite well with the observed vector directions, field strengths, and decay times of the electric and magnetic fields in CRIT 2. The possibility to extend the model to the active region, where the ions are produces in this type of self-ionizing injection experiments, is discussed.

  8. Toward the correspondence between Q-clouds and sphalerons

    NASA Astrophysics Data System (ADS)

    Nugaev, E.; Shkerin, A.

    2015-07-01

    Non-linear classical equations of motion may admit degenerate solutions at fixed charges. Whereas the solutions with lower energies are classically stable, those with larger energies are unstable and are referred to as Q-clouds. We consider a theory in which a homogeneous charged condensate is classically stable and argue that Q-clouds correspond to sphalerons between the stable Q-balls and the condensate. For a model with an analytical solution, we present the Arrhenius formula for the quantum production of Q-balls from a condensate at high temperatures.

  9. Images from Galileo of the Venus cloud deck

    USGS Publications Warehouse

    Belton, M.J.S.; Gierasch, P.J.; Smith, M.D.; Helfenstein, P.; Schinder, P.J.; Pollack, James B.; Rages, K.A.; Ingersoll, A.P.; Klaasen, K.P.; Veverka, J.; Anger, C.D.; Carr, M.H.; Chapman, C.R.; Davies, M.E.; Fanale, F.P.; Greeley, R.; Greenberg, R.; Head, J. W., III; Morrison, D.; Neukum, G.; Pilcher, C.B.

    1991-01-01

    Images of Venus taken at 418 (violet) and 986 [near-infrared (NIR)] nanometers show that the morphology and motions of large-scale features change with depth in the cloud deck. Poleward meridional velocities, seen in both spectral regions, are much reduced in the NIR. In the south polar region the markings in the two wavelength bands are strongly anticorrelated. The images follow the changing state of the upper cloud layer downwind of the subsolar point, and the zonal flow field shows a longitudinal periodicity that may be coupled to the formation of large-scale planetary waves. No optical lightning was detected.

  10. Collisional excitation of molecules in dense interstellar clouds

    NASA Technical Reports Server (NTRS)

    Green, S.

    1985-01-01

    State transitions which permit the identification of the molecular species in dense interstellar clouds are reviewed, along with the techniques used to calculate the transition energies, the database on known molecular transitions and the accuracy of the values. The transition energies cannot be measured directly and therefore must be modeled analytically. Scattering theory is used to determine the intermolecular forces on the basis of quantum mechanics. The nuclear motions can also be modeled with classical mechanics. Sample rate constants are provided for molecular systems known to inhabit dense interstellar clouds. The values serve as a database for interpreting microwave and RF astrophysical data on the transitions undergone by interstellar molecules.

  11. Motion-compensated subband coding with scene adaptivity

    NASA Astrophysics Data System (ADS)

    Lee, Jungwoo; Dickinson, Bradley W.

    1994-05-01

    This paper presents a new motion compensated subband video coding algorithm with scene adaptive motion interpolation. The work builds on temporal segmentation for determining the reference frame positions, and multi-resolution motion estimation in the subband domain. In the proposed approach, the reference frames for motion estimation are adaptively selected using the temporal segmentation of the lowest spatial subband. Motion compensation is used after subband filtering because it produces better performance than subband filtering after motion compensation. The proposed scene adaptive scheme, temporally adaptive motion interpolation (TAMI), determines the number and the positions of the reference frames for motion estimation using two types of temporal segmentation algorithms. The input video is split into the 7 spatial subbands by using a pair of low-pass and high-pass biorthogonal filters, and the TAMI algorithm is applied on the lowest of the subbands. Motion vectors for each subband are generated by a hierarchical motion estimation approach. Block-wise DPCM and a uniform quantizer are used only for the lowest subband of an intra frame, and all the other subbands are coded by PCM with a dead-zone quantizer. Simulation results show that the scene adaptive scheme compares favorably with the fixed interpolation structure.

  12. FORMATION OF MASSIVE MOLECULAR CLOUD CORES BY CLOUD-CLOUD COLLISION

    SciTech Connect

    Inoue, Tsuyoshi [Department of Physics and Mathematics, Aoyama Gakuin University, Sagamihara, Kanagawa 252-5258 (Japan); Fukui, Yasuo, E-mail: inouety@phys.aoyama.ac.jp [Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)

    2013-09-10

    Recent observations of molecular clouds around rich massive star clusters including NGC 3603, Westerlund 2, and M20 revealed that the formation of massive stars could be triggered by a cloud-cloud collision. By using three-dimensional, isothermal, magnetohydrodynamics simulations with the effect of self-gravity, we demonstrate that massive, gravitationally unstable, molecular cloud cores are formed behind the strong shock waves induced by cloud-cloud collision. We find that the massive molecular cloud cores have large effective Jeans mass owing to the enhancement of the magnetic field strength by shock compression and turbulence in the compressed layer. Our results predict that massive molecular cloud cores formed by the cloud-cloud collision are filamentary and threaded by magnetic fields perpendicular to the filament.

  13. Marine cloud brightening

    PubMed Central

    Latham, John; Bower, Keith; Choularton, Tom; Coe, Hugh; Connolly, Paul; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan; Galbraith, Lee; Iacovides, Hector; Johnston, David; Launder, Brian; Leslie, Brian; Meyer, John; Neukermans, Armand; Ormond, Bob; Parkes, Ben; Rasch, Phillip; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Rob

    2012-01-01

    The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could—subject to satisfactory resolution of technical and scientific problems identified herein—have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seed-particle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud–albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100×100?km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action. PMID:22869798

  14. Studying Clouds and Climate

    NSDL National Science Digital Library

    2007-01-02

    With three levels to choose from on each page - beginner, intermediate or advanced - this site provides information on the role of CMMAP in the exploration of clouds and climate.CMMAP stands for the Center for Multi-Scale Modeling of Atmospheric Processes. CMMAP scientists are working on a new way to model the climate that will help us to better understand the roles clouds play today and in the future as our climate changes.

  15. Cloud computing security auditing

    Microsoft Academic Search

    Irfan Gul; Atiq ur Rehman; M Hasan Islam

    2011-01-01

    In the recent era, cloud computing has evolved as a net centric, service oriented computing model. Consumers purchase computing resources as on-demand basis and get worry free with the underlying technologies used. Cloud computing model is composed of three service models Software as a Service (SaaS), Platform as a Service (PaaS) and Infrastructure as a Service (IaaS) and four deployment

  16. A double motion-compensated orthogonal transform with energy concentration constraint

    NASA Astrophysics Data System (ADS)

    Flierl, Markus; Girod, Bernd

    2007-01-01

    This paper discusses a transform for successive pictures of an image sequence which strictly maintains orthogonality while permitting 2-hypothesis motion compensation between pairs of pictures. We extend previous work on an orthogonal transform for image sequences which uses only 1-hypothesis motion compensation between pairs of pictures. This work is motivated by the well known fact that the motion-compensated lifted Haar wavelet maintains orthogonality only approximately. In the case of zero motion fields, the motion-compensated lifted Haar wavelet is known to be orthogonal. But for complex motion fields with many multi-connected and unconnected pixels, the motion-compensated lifted Haar wavelet cannot accurately maintain its transform property and, hence, suffers a performance degradation. The presented double motion-compensated orthogonal transform strictly maintains orthogonality for any motion field. For the transform, each pixel in the high-band is compensated by a linear combination of two motion-compensated pixels chosen from the corresponding low-band. That is, each pixel in the high-band is associated with two motion vectors. This is in contrast to the previously presented single motion-compensated orthogonal transform where each pixel in the high-band is compensated by only one motion-compensated pixel chosen from the corresponding low-band. In terms of energy concentration, the double motion-compensated orthogonal transform outperforms the single motion-compensated orthogonal transform and compares favorably with the double motion-compensated lifted Haar wavelet.

  17. Assimilation of GOES-Derived Cloud Fields Into MM5

    NASA Astrophysics Data System (ADS)

    Biazar, A. P.; Doty, K. G.; McNider, R.

    2007-12-01

    This approach for the assimilation of GOES-derived cloud data into an atmospheric model (the Fifth-Generation Pennsylvania State University-National Center for Atmospheric Research Mesoscale Model, or MM5) was performed in two steps. In the first step, multiple linear regression equations were developed using a control MM5 simulation to develop relationships for several dependent variables in model columns that had one or more layers of clouds. In the second step, the regression equations were applied during an MM5 simulation with assimilation in which the hourly GOES satellite data were used to determine the cloud locations and some of the cloud properties, but with all the other variables being determined by the model data. The satellite-derived fields used were shortwave cloud albedo and cloud top pressure. Ten multiple linear regression equations were developed for the following dependent variables: total cloud depth, number of cloud layers, depth of the layer that contains the maximum vertical velocity, the maximum vertical velocity, the height of the maximum vertical velocity, the estimated 1-h stable (i.e., grid scale) precipitation rate, the estimated 1-h convective precipitation rate, the height of the level with the maximum positive diabatic heating, the magnitude of the maximum positive diabatic heating, and the largest continuous layer of upward motion. The horizontal components of the divergent wind were adjusted to be consistent with the regression estimate of the maximum vertical velocity. The new total horizontal wind field with these new divergent components was then used to nudge an ongoing MM5 model simulation towards the target vertical velocity. Other adjustments included diabatic heating and moistening at specified levels. Where the model simulation had clouds when the satellite data indicated clear conditions, procedures were taken to remove or diminish the errant clouds. The results for the period of 0000 UTC 28 June - 0000 UTC 16 July 1999 for both a continental 32-km grid and an 8-km grid over the Southeastern United States indicate a significant improvement in the cloud bias statistics. The main improvement was the reduction of high bias values that indicated times and locations in the control run when there were model clouds but when the satellite indicated clear conditions. The importance of this technique is that it has been able to assimilate the observed clouds in the model in a dynamically sustainable manner. Acknowledgments. This work was partially funded by the following grants: a GEWEX grant from NASA , the Cooperative Agreement between the University of Alabama in Huntsville and the Minerals Management Service on Gulf of Mexico Issues, a NASA applications grant, and a NSF grant.

  18. First observations of tracking clouds using scanning ARM cloud radars

    DOE PAGESBeta

    Borque, Paloma; Giangrande, Scott; Kollias, Pavlos

    2014-12-01

    Tracking clouds using scanning cloud radars can help to document the temporal evolution of cloud properties well before large drop formation (‘‘first echo’’). These measurements complement cloud and precipitation tracking using geostationary satellites and weather radars. Here, two-dimensional (2-D) Along-Wind Range Height Indicator (AW-RHI) observations of a population of shallow cumuli (with and without precipitation) from the 35-GHz scanning ARM cloud radar (SACR) at the DOE Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) site are presented. Observations from the ARM SGP network of scanning precipitation radars are used to provide the larger scale context of the cloud fieldmore »and to highlight the advantages of the SACR to detect the numerous, small, non-precipitating cloud elements. A new Cloud Identification and Tracking Algorithm (CITA) is developed to track cloud elements. In CITA, a cloud element is identified as a region having a contiguous set of pixels exceeding a preset reflectivity and size threshold. The high temporal resolution of the SACR 2-D observations (30 sec) allows for an area superposition criteria algorithm to match cloud elements at consecutive times. Following CITA, the temporal evolution of cloud element properties (number, size, and maximum reflectivity) is presented. The vast majority of the designated elements during this cumulus event were short-lived non-precipitating clouds having an apparent life cycle shorter than 15 minutes. The advantages and disadvantages of cloud tracking using an SACR are discussed.« less

  19. First observations of tracking clouds using scanning ARM cloud radars

    DOE PAGESBeta

    Borque, Paloma [McGill Univ., Montreal, QC (Canada); Giangrande, Scott [Brookhaven National Lab. (BNL), Upton, NY (United States); Kollias, Pavlos [McGill Univ., Montreal, QC (Canada)

    2014-12-01

    Tracking clouds using scanning cloud radars can help to document the temporal evolution of cloud properties well before large drop formation (‘‘first echo’’). These measurements complement cloud and precipitation tracking using geostationary satellites and weather radars. Here, two-dimensional (2-D) Along-Wind Range Height Indicator (AW-RHI) observations of a population of shallow cumuli (with and without precipitation) from the 35-GHz scanning ARM cloud radar (SACR) at the DOE Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) site are presented. Observations from the ARM SGP network of scanning precipitation radars are used to provide the larger scale context of the cloud field and to highlight the advantages of the SACR to detect the numerous, small, non-precipitating cloud elements. A new Cloud Identification and Tracking Algorithm (CITA) is developed to track cloud elements. In CITA, a cloud element is identified as a region having a contiguous set of pixels exceeding a preset reflectivity and size threshold. The high temporal resolution of the SACR 2-D observations (30 sec) allows for an area superposition criteria algorithm to match cloud elements at consecutive times. Following CITA, the temporal evolution of cloud element properties (number, size, and maximum reflectivity) is presented. The vast majority of the designated elements during this cumulus event were short-lived non-precipitating clouds having an apparent life cycle shorter than 15 minutes. The advantages and disadvantages of cloud tracking using an SACR are discussed.

  20. Electron cloud in accelerators

    NASA Astrophysics Data System (ADS)

    Cimino, Roberto; Demma, Theo

    2014-06-01

    Low energy electrons in accelerators are known to interact with the circulating beam, giving rise to the formation of a so-called e- cloud. Such e- cloud may induce detrimental effects on the accelerated beam quality and stability. Those effects have been observed in most accelerators of positively charged particles. A longstanding effort has been so far devoted to understand in detail the physical origin of such e- cloud, its build-up and its interaction with the circulating beam. We will first describe the origin and the basic features causing e- cloud formation in accelerators, then we review some of the theoretical work produced to simulate and analyze such phenomenon. In selected cases, theoretical expectations and experimental observations will be compared, to address the importance of benchmarking codes versus observations to reach the required predictive capability. To this scope, codes need realistic input parameters which correctly describe material and surface properties at the basis of such e- cloud formation and build-up. The experimental efforts, performed worldwide in many surface and material science laboratories, to measure such essential parameters will then be presented and critically reviewed. Finally, we will describe some of the e- cloud mitigation strategies adopted so far and draw some conclusions.

  1. A cloud physics radiometer

    NASA Technical Reports Server (NTRS)

    Kyle, H. L.; Curran, R. J.; Barnes, W. L.; Escoe, D.

    1978-01-01

    The paper describes the design features and capabilities of a seven-channel cloud physics radiometer (CPR) for remote sensing of cloud properties. The CPR channel characteristics and functions are tabulated and diagrammed. Each of the first three channels utilizes a photo-multipler detector, with the high-voltage power supply integrated with the tube into a single unit. In operation a heater is used to keep the optics temperature at or above 273 K and this temperature is constantly monitored. The last four channel detectors and filters are all cooled to the temperature of liquid nitrogen. The inclined scanning mirror rotates at a rate of 3.48 rps. Registration pulses are triggered and recorded as the mirror enters and leaves the + or -45 deg earth observation region. The ice-cloud, water cloud, snow discriminator detector has worked quite well in general. Interesting radiometer data have been obtained and their analysis is under way. The combination of the CPR and the Cloud Lidar System will make possible sophisticated remote sensing cloud studies.

  2. Motion coherence affects human perception and pursuit similarly

    NASA Technical Reports Server (NTRS)

    Beutter, B. R.; Stone, L. S.

    2000-01-01

    Pursuit and perception both require accurate information about the motion of objects. Recovering the motion of objects by integrating the motion of their components is a difficult visual task. Successful integration produces coherent global object motion, while a failure to integrate leaves the incoherent local motions of the components unlinked. We compared the ability of perception and pursuit to perform motion integration by measuring direction judgments and the concomitant eye-movement responses to line-figure parallelograms moving behind stationary rectangular apertures. The apertures were constructed such that only the line segments corresponding to the parallelogram's sides were visible; thus, recovering global motion required the integration of the local segment motion. We investigated several potential motion-integration rules by using stimuli with different object, vector-average, and line-segment terminator-motion directions. We used an oculometric decision rule to directly compare direction discrimination for pursuit and perception. For visible apertures, the percept was a coherent object, and both the pursuit and perceptual performance were close to the object-motion prediction. For invisible apertures, the percept was incoherently moving segments, and both the pursuit and perceptual performance were close to the terminator-motion prediction. Furthermore, both psychometric and oculometric direction thresholds were much higher for invisible apertures than for visible apertures. We constructed a model in which both perception and pursuit are driven by a shared motion-processing stage, with perception having an additional input from an independent static-processing stage. Model simulations were consistent with our perceptual and oculomotor data. Based on these results, we propose the use of pursuit as an objective and continuous measure of perceptual coherence. Our results support the view that pursuit and perception share a common motion-integration stage, perhaps within areas MT or MST.

  3. Soret motion of a charged spherical colloid.

    PubMed

    Rasuli, Seyyed Nader; Golestanian, Ramin

    2008-09-01

    The thermophoretic motion of a charged spherical colloidal particle and its accompanying cloud of counterions and coions in a temperature gradient is studied theoretically. Using the Debye-Hückel approximation, the Soret drift velocity of a weakly charged colloid is calculated analytically. For highly charged colloids, the nonlinear system of electrokinetic equations is solved numerically, and the effects of high surface potential, dielectrophoresis, and convection are examined. Our results are in good agreement with some of the recent experiments on highly charged colloids without using adjustable parameters. PMID:18851261

  4. Insect Vectors of Human Pathogens

    NSDL National Science Digital Library

    0000-00-00

    Four orders of insects (Hemiptera, Phthiraptera, Diptera, and Siphonaptera) are covered detailing vector species along with their pathogens of human importance. Links to pathogens as well as vectors are highlighted (some of these are CDC, and WHO).

  5. Nonviral Vectors for Gene Delivery

    E-print Network

    Baoum, Abdulgader Ahmed

    2011-04-26

    The development of nonviral vectors for safe and efficient gene delivery has been gaining considerable attention recently. An ideal nonviral vector must protect the gene against degradation by nuclease in the extracellular matrix, internalize...

  6. Concord Consortium: Seeing Motion

    NSDL National Science Digital Library

    2012-04-23

    This activity explores simple, straight-line motion by blending a motion sensor lab with student-generated digital graphs of distance versus time. First, learners use the online graph sketching tool to predict the motion of a person walking forward and backward over a 4-meter track in 30 seconds. Next, they try to reproduce their prediction graphs using a motion sensor to collect data. Finally, they analyze differences in slope between their original predictions and the actual data from the motion sensor. This resource is part of the Concord Consortium, a nonprofit research and development organization dedicated to transforming education through technology.

  7. The Dynamical State of Barnard 68: A Thermally Supported, Pulsating Dark Cloud.

    NASA Astrophysics Data System (ADS)

    Lada, C. J.; Bergin, E. A.; Alves, J. F.; Huard, T. L.

    2002-12-01

    We report sensitve, high resolution molecular-line observations of the dark cloud Barnard 68 obtained with the IRAM 30-m telescope. We analyze spectral-line observations of C18O (1-0), C32S(2-1), and N2H+ (1-0) in order to investigate the kinematics of the cloud. We find extremely narrow linewidths consistent with thermally broadened profiles for the measured gas temperature of 10.5 K. We determine the thermal pressure to be at least 4-5 times greater than the non-thermal (turbulent) pressure in the central regions of the cloud, indicating that thermal pressure is the primary source of support against gravity in this cloud. The rotational kinetic energy is found to be only a few percent of the gravitational potential energy, indicating that the contribution of rotation to the overall stability of the cloud is insignificant. We find that the C32S line is optically thick and self-reversed across nearly the entire projected surface of the cloud. The shapes of the self-reversed profiles are asymmetric with evidence for both inward and outward motions at different locations across the cloud. Moreover, these motions appear to be organized in a clear and systematic alternating spatial pattern which is suggestive of a small amplitude, non-radial mode oscillation or pulsation of the cloud's outer layers.

  8. Motion of Air Bubbles in Water Subjected to Microgravity Accelerations

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard; Kelly, Eric M.; Hrovar, Kenneth; Nelson, Emily S.; Pettit, Donald R.

    2004-01-01

    The International Space Station (ISS) serves as a platform for microgravity research for the foreseeable future. A microgravity environment is one in which the effects of gravity are drastically reduced which then allows physical experiments to be conducted without the overpowering effects of gravity. During his six month stay on the ISS, astronaut Donald R Pettit performed many informal/impromptu science experiments with available equipment. One such experiment focused on the motion of air bubbles in a rectangular container nearly filled with de-ionized water. Bubbles were introduced by shaking and the container was secured in place for several hours while motion of the bubbles were recorded using time-lapse photography. This paper shows correlation between bubble motion and quasi-steady acceleration levels during one such experiment operation. The quasi-steady acceleration vectors were measured by the Microgravity Acceleration Measurement System. Essentially linear motion was observed in the condition considered here. Dr. Pettit also created other conditions which produced linear and circulating motion, which are the subjects of further study. Initial observations of this bubble motion agree with calculations from many microgravity physical science experiments conducted on Shuttle microgravity science missions. Many crystal-growth furnaces involve heavy metals and high temperatures in which undesired acceleration-driven convection during solidification can adversely affect the crystal. Presented in this paper will be results showing correlation between bubble motion and the quasi-steady acceleration vector.

  9. Motionally-induced electromagnetic fields generated by idealized ocean currents

    Microsoft Academic Search

    R. H. Tyler; L. A. Mysak

    1995-01-01

    Using the induction equation, we investigate the generation of electromagnetic fields by the motional electromagnetic induction due to ocean currents. In this paper, solutions are presented for a linear induction equation for the magnetic flux density vector which contains prescribed time-independent ocean current and conductivity fields. Once the magnetic flux density is known, the electric field and electric current density

  10. Response of Tropical Clouds to the Interannual Variation of Sea Surface Temperature

    NASA Technical Reports Server (NTRS)

    Fu, Rong; Liu, W. Timothy; Dickinson, Robert E.

    1996-01-01

    Connections between the large-scale interannual variations of clouds, deep convection, atmospheric winds. vertical thermodynamic structure, and SSTs over global tropical oceans are examined over the period July 1983 - December 1990. The SST warming associated with El Nino had a significant impact on the global tropical cloud field, although the warming itself was confined to the equatorial central and eastern Pacific. Extensive variations of the total cloud field occurred in the northeastern Indian, western and central Pacific, and western Atlantic Oceans. The changes of high and middle clouds dominated the total cloud variation in these regions. Total cloud variation was relatively weak in the eastern Pacific and the Atlantic because of the cancellation between the changes of high and low clouds. The variation of low clouds dominated the total cloud change in those areas. The destabilization of the lapse rate between 900 and 750 mb was more important for enhancing convective instability than was the change of local SSTs in the equatorial central Pacific during the 1997 El Nino. This destabilization is associated with anomalous rising motion in that region. As a result. convection and high and middle clouds increased in the equatorial central Pacific, In the subtropical Pacific, both the change of lapse rate between 900 and 750 mb associated A,ith anomalous subsidence and the decrease of boundary-layer buoyancy due to a decrease of temperature and moisture played an important role in enhancing convective stability. Consequently, convection, as well its high and middle clouds, decreased in these areas. The change ot'low clouds in the equatorial and southeastern Atlantic was correlated to both local SSTs and the SST changes in the equatorial eastern Pacific. In this area. the increase of low clouds was consistent with the sharper inversion during the 1987 El Nino, The strengthening of the inversion was not caused by a local SST change. although the local SST change appeared to he correlated to the change of low clouds. The coherence between clouds and SST tendency shows that SST tendency leads cloud variation in the equatorial Pacific. Thus, the change of clouds does not dominate the sign of SST tendency even though the cloud change was maximum during the 1987 El Nino. In some ideas of the Indian, subtropical Pacific, and North Atlantic Oceans, cloud change leads SST tendency. Cloud change might affect SST tendency in these regions.

  11. Dual motion valve with single motion input

    NASA Technical Reports Server (NTRS)

    Belew, Robert (inventor)

    1987-01-01

    A dual motion valve includes two dual motion valve assemblies with a rotary input which allows the benefits of applying both rotary and axial motion to a rotary sealing element with a plurality of ports. The motion of the rotary sealing element during actuation provides axial engagement of the rotary sealing element with a stationary valve plate which also has ports. Fluid passages are created through the valve when the ports of the rotary sealing element are aligned with the ports of the stationary valve plate. Alignment is achieved through rotation of the rotary sealing element with respect to the stationary valve plate. The fluid passages provide direct paths which minimize fluid turbulence created in the fluid as it passes through the valve.

  12. Some experiences with Krylov vectors and Lanczos vectors

    NASA Technical Reports Server (NTRS)

    Craig, Roy R., Jr.; Su, Tzu-Jeng; Kim, Hyoung M.

    1993-01-01

    This paper illustrates the use of Krylov vectors and Lanczos vectors for reduced-order modeling in structural dynamics and for control of flexible structures. Krylov vectors and Lanczos vectors are defined and illustrated, and several applications that have been under study at The University of Texas at Austin are reviewed: model reduction for undamped structural dynamics systems, component mode synthesis using Krylov vectors, model reduction of damped structural dynamics systems, and one-sided and two-sided unsymmetric block-Lanczos model-reduction algorithms.

  13. PhET Simulation: Motion in 2D

    NSDL National Science Digital Library

    This is an interactive simulation created to help beginners differentiate velocity and acceleration vectors. The user can move a ball with the mouse or let the simulation move the ball in four modes of motion (two types of linear, simple harmonic, and circular). Two vectors are displayed -- one green and one blue. As the motion of the ball changes, the vectors also change. Which color represents velocity and which acceleration? Editor's Note: This simulation was designed with improvements based on research of student interaction with the PhET resource "Ladybug Revolution". The authors added two new features for the beginning learner: linear acceleration and harmonic motion. To supplement the simulation, we recommend the Physics Classroom tutorial "Vectors and Direction" and the teacher-created lesson, "Vectors Phet Lab" -- see links in Related Materials. This item is part of a larger and growing collection of resources developed by the Physics Education Technology project (PhET), each designed to implement principles of physics education research.

  14. Kernel uncorrelated optimal discriminant vectors

    NASA Astrophysics Data System (ADS)

    Yang, Yuwang; Yang, Jingyu; Jin, Zhong

    2003-09-01

    We construct kernel uncorrelated optimal discriminant vectors(KUODV) for non-linear feature extraction and discrimination. Employing the uncorrelated optimal discriminant vectors(UODV) and kernel method, we propose non-linear generalization of uncorrelated optimal discriminant vectors, and then enhance the performance of original UODV. Human face recognition experiments show the utility of our new method.

  15. Statistical analysis of cointegration vectors

    Microsoft Academic Search

    Soren Johansen

    1988-01-01

    We consider a nonstationary vector autoregressive process which is integrated of order 1, and generated by i.i.d. Gaussian errors. We then derive the maximum likelihood estimator of the space of cointegration vectors and the likelihood ratio test of the hypothesis that it has a given number of dimensions. Further we test linear hypotheses about the cointegration vectors. The asymptotic distribution

  16. Nonlinear Vector Analyzers [review of \\

    Microsoft Academic Search

    Alfy Riddle

    2012-01-01

    This book offers the reader a tour of how nonlinear vector analyzers work and how they can be used in circuit design. It contains nine chapters and no appendices. The two key chapters describe nonlinear vector instrumentation and describe behavioral modeling. In many places, the book goes into lengthy descriptions of nonlinear vector analyzer calibration, device heating, semiconductor traps, and

  17. Student Preconceptions about Vector Kinematics.

    ERIC Educational Resources Information Center

    Aguirre, Jose M.

    1988-01-01

    Examines preconceptions regarding several implicit vector characteristics that 15- to 17-year-old students possess just before taking their first physics course. Shows seven vector characteristics and three tasks for interviewing students. Presents the most common student preconceptions regarding each of the implicit vector characteristics. (YP)

  18. Vector spaces Linear independence & bases

    E-print Network

    Geuvers, Herman

    Vector spaces Linear independence & bases Linear maps Linear maps and matrices Radboud University Nijmegen Matrix Calculations: Vector Spaces and Linear Maps H. Geuvers Institute for Computing: fall 2014 Matrix Calculations 1 / 40 #12;Vector spaces Linear independence & bases Linear maps Linear

  19. On Multi-Vector Spaces

    E-print Network

    Linfan Mao

    2005-10-22

    A Smarandache multi-space is a union of $n$ spaces $A_1,A_2,..., A_n$ with some additional conditions holding. Combining Smarandache multi-spaces with linear vector spaces in classical linear algebra, the conception of multi-vector spaces is introduced. Some characteristics of a multi-vector space are obtained in this paper.

  20. Support vector networks Sance svn

    E-print Network

    Bouzy, Bruno

    Support vector networks Séance « svn » de l'UE « apprentissage automatique » Bruno Bouzy bruno.bouzy@parisdescartes.fr www.mi.parisdescartes.fr/~bouzy #12;Support-vector networks Reference · These slides present the following paper: ­ C.Cortes, V.Vapnik, « support vector networks », Machine Learning (1995

  1. GEWEX Cloud Systems Study (GCSS)

    NASA Technical Reports Server (NTRS)

    Moncrieff, Mitch

    1993-01-01

    The Global Energy and Water Cycle Experiment (GEWEX) Cloud Systems Study (GCSS) program seeks to improve the physical understanding of sub-grid scale cloud processes and their representation in parameterization schemes. By improving the description and understanding of key cloud system processes, GCSS aims to develop the necessary parameterizations in climate and numerical weather prediction (NWP) models. GCSS will address these issues mainly through the development and use of cloud-resolving or cumulus ensemble models to generate realizations of a set of archetypal cloud systems. The focus of GCSS is on mesoscale cloud systems, including precipitating convectively-driven cloud systems like MCS's and boundary layer clouds, rather than individual clouds, and on their large-scale effects. Some of the key scientific issues confronting GCSS that particularly relate to research activities in the central U.S. are presented.

  2. Vector Theory of Gravity

    E-print Network

    V. N. Borodikhin

    2011-04-14

    We proposed a gravitation theory based on an analogy with electrodynamics on the basis of a vector field. For the first time, to calculate the basic gravitational effects in the framework of a vector theory of gravity, we use a Lagrangian written with gravitational radiation neglected and generalized to the case of ultra-relativistic speeds. This allows us to accurately calculate the values of all three major gravity experiments: the values of the perihelion shift of Mercury, the light deflection angle in the gravity field of the Sun and the value of radar echo delay. The calculated values coincide with the observed ones. It is shown that, in this theory, there exists a model of an expanding Universe.

  3. Temporal evolution of the Evershed flow in sunspots. I. Observational characterization of Evershed clouds

    NASA Astrophysics Data System (ADS)

    Cabrera Solana, D.; Bellot Rubio, L. R.; Beck, C.; Del Toro Iniesta, J. C.

    2007-12-01

    Context: The magnetic and kinematic properties of the photospheric Evershed flow are relatively well known, but not completely understood. The evolution of the flow with time, which is mainly due to the appearance of velocity packets called Evershed clouds (ECs), may provide information to further constrain its origin. Aims: We undertake a detailed analysis of the evolution of the Evershed flow by studying the properties of ECs. In this first paper we determine the sizes, proper motions, location in the penumbra, and frequency of appearance of ECs, as well as their typical Doppler velocities, linear and circular polarization signals, Stokes V area asymmetries, and continuum intensities. Methods: High-cadence, high-resolution, full vector spectropolarimetric measurements in visible and infrared lines are used to characterize the EC phenomenon through a simple line-parameter analysis. Results: ECs appear in the mid penumbra and propagate outward along filaments having large linear polarization signals and enhanced Evershed flows. The frequency of appearance of ECs varies between 15 and 40 min in different filaments. ECs exhibit the largest Doppler velocities and linear-to-circular polarization ratios of the whole penumbra. In addition, lines formed deeper in the atmosphere show larger Doppler velocities, much in the same way as the “quiescent” Evershed flow. According to our observations, ECs can be classified in two groups: type I ECs, which vanish in the outer penumbra, and type II ECs, which cross the outer penumbral boundary and enter the sunspot moat. Most of the observed ECs belong to type I. On average, type II ECs can be detected as velocity structures outside of the spot for only about 14 min. Their proper motions in the moat are significantly reduced with respect to the ones they had in the penumbra. Appendices A and B are only available in electronic form at http://www.aanda.org

  4. CloudSafe: Securing Data Processing within Vulnerable Virtualization Environments in the Cloud

    E-print Network

    Yao, Danfeng "Daphne'

    CloudSafe: Securing Data Processing within Vulnerable Virtualization Environments in the Cloud large-scale cloud applications. Index Terms--cloud security, outsourced computation, side- channel, newly discovered vulnerabilities in cloud virtualization envi- ronment have threatened the security

  5. A new motion parameter estimation algorithm based on the continuous wavelet transform

    Microsoft Academic Search

    Fernando A. Mujica; Jean-pierre Leduc; Romain Murenzi; Mark J. T. Smith

    2000-01-01

    This paper presents a novel motion parameter estimation (ME) algorithm based on the spatio-temporal continuous wavelet transform (CWT). The multidimensional nature of the CWT allows for the definition of a multitude of energy densities by integrating over a subset of the CWT parameter space. Three energy densities are used to estimate motion parameters by sequentially optimizing a state vector composed

  6. Maximally symmetric vector propagator

    SciTech Connect

    Tsamis, N. C.; Woodard, R. P. [Department of Physics, University of Crete, GR-710 03 Heraklion (Greece); Department of Physics, University of Florida, Gainesville, Florida 32611 (United States)

    2007-05-15

    We derive the propagator for a massive vector field on a de Sitter background of arbitrary dimension. This propagator is de Sitter invariant and possesses the proper flat space-time and massless limits. Moreover, the retarded Green's function inferred from it produces the correct classical response to a test source. Our result is expressed in a tensor basis which is convenient for performing quantum-field-theory computations using dimensional regularization.

  7. Vector Magnetograph Design

    NASA Technical Reports Server (NTRS)

    Chipman, Russell A.

    1996-01-01

    This report covers work performed during the period of November 1994 through March 1996 on the design of a Space-borne Solar Vector Magnetograph. This work has been performed as part of a design team under the supervision of Dr. Mona Hagyard and Dr. Alan Gary of the Space Science Laboratory. Many tasks were performed and this report documents the results from some of those tasks, each contained in the corresponding appendix. Appendices are organized in chronological order.

  8. Vector BPS Skyrme model

    NASA Astrophysics Data System (ADS)

    Adam, C.; Naya, C.; Sanchez-Guillen, J.; Wereszczynski, A.

    2012-10-01

    We analyze the vector meson formulation of the Bogomol’nyi-Prasad-Sommerfield (BPS) Skyrme model in (3+1) dimensions, where the term of sixth power in first derivatives characteristic for the original, integrable BPS Skyrme model (the topological or baryon current squared) is replaced by a coupling between the vector meson ?? and the baryon current. We find that the model remains integrable in the sense of generalized integrability and almost solvable (reducible to a set of two first-order ordinary differential equations) for any value of the baryon charge. Further, we analyze the appearance of topological solitons for two one-parameter families of one-vacuum potentials: the old Skyrme potentials and the so-called BPS potentials. Depending on the value of the parameters, we find several qualitatively different possibilities. In the massless case, we have a parameter region with no Skyrmions, a unique compact Skyrmion with a discontinuous first derivative at the boundary (equivalently, with a source term located at the boundary, which screens the topological charge), and Coulomb-like localized solitons. For the massive vector meson, besides the no-Skyrmion region and a unique C-compact soliton, we find exponentially as well as power-like localized Skyrmions. Further, we find (for a specific potential) BPS solutions, i.e., Skyrmions saturating a Bogomolny bound (both for the massless and massive vector mesons), which are unstable for higher values of the baryon charge. The properties of the model are finally compared with its baby version in (2+1) dimensions and with the original BPS Skyrme model, contributing to a better understanding of the latter.

  9. Recurrent Support Vector Machines

    Microsoft Academic Search

    Matteo Gagliolo; Daan Wierstra; Faustino Gomez; IDSIA Galleria

    Abstract Existing Support Vector Machines (SVMs) need pre-wired finite time windo ws to predict and classify time series. They do not have an internal state necessary to deal with sequences involving arbitrary long-term dependencies. Here we introduce the first recurrent, truly s equential SVM-like devices with internal adaptive states, trained by a novel method called EVOlution of systems with KErnel-based

  10. A genetic approach to the history of the Magellanic Clouds

    NASA Astrophysics Data System (ADS)

    Guglielmo, Magda; Lewis, Geraint F.; Bland-Hawthorn, Joss

    2014-10-01

    The history of the Magellanic Clouds is investigated using N-body hydrodynamic simulations where the initial conditions are set by a genetic algorithm. This technique allows us to identify possible orbits for the Magellanic Clouds around the Milky Way, by directly comparing the simulations with observational constraints. We explore the parameter space of the interaction between the Magellanic Clouds and the Milky Way, considering as free parameters the proper motions of the Magellanic Clouds, the virial mass and the concentration parameter (c) of the Galactic dark matter halo. The best orbital scenarios presented here are considered with two different sets of parameters for the Milky Way disc and bulge components. The total circular velocity at the Sun's position (R? = 8.5 kpc) is directly calculated from the rotation curve of the corresponding Galactic mass model. Our analysis suggests that the Magellanic Clouds have orbited inside the virial radius of the Milky Way for at least 3 Gyr, even for low-mass haloes. However, this is possible only with high values for the concentration parameter (c ? 20). In both orbital models presented here, the mutual interaction between the Magellanic Clouds is able to reproduce the observed features of the Magellanic System.

  11. Biological motion alters coherent motion perception.

    PubMed

    Fujimoto, Kiyoshi; Yagi, Akihiro

    2008-01-01

    When a movie presents a person walking, the background appears to move in the direction opposite to the person's gait. This study verified this backscroll illusion by presenting a point-light walker against a background of a random-dot cinematogram (RDC). The RDC consisted of some signal dots moving coherently either leftward or rightward among other noise dots moving randomly. The method of constant stimuli was used to vary the RDC in motion coherence from trial to trial by manipulating the direction and percentage of the signal dots. Six observers judged the perceived direction of coherent motion in a two-alternative forced-choice procedure. Response rates for coherent motion perception in the direction opposite to walking were evaluated as a function of motion coherence. The results showed that the psychometric function shifted toward the direction determined by a bias in the opposite direction to the walker. The mean threshold was about half as high as that in a control condition in which the positions of the point-lights were scrambled to impair the recognition of the walker. The results demonstrate that biological motion noticeably affects the appearance of motion coherence in the background. PMID:19227372

  12. Anisotropic responses to motion toward and away from the eye

    NASA Technical Reports Server (NTRS)

    Perrone, John A.

    1986-01-01

    When a rigid object moves toward the eye, it is usually perceived as being rigid. However, in the case of motion away from the eye, the motion and structure of the object are perceived nonveridically, with the percept tending to reflect the nonrigid transformations that are present in the retinal image. This difference in response to motion to and from the observer was quantified in an experiment using wire-frame computer-generated boxes which moved toward and away from the eye. Two theoretical systems are developed by which uniform three-dimensional velocity can be recovered from an expansion pattern of nonuniform velocity vectors. It is proposed that the human visual system uses two similar systems for processing motion in depth. The mechanism used for motion away from the eye produces perceptual errors because it is not suited to objects with a depth component.

  13. Probabilistic seismic demand analysis using advanced ground motion intensity measures

    USGS Publications Warehouse

    Tothong, P.; Luco, N.

    2007-01-01

    One of the objectives in performance-based earthquake engineering is to quantify the seismic reliability of a structure at a site. For that purpose, probabilistic seismic demand analysis (PSDA) is used as a tool to estimate the mean annual frequency of exceeding a specified value of a structural demand parameter (e.g. interstorey drift). This paper compares and contrasts the use, in PSDA, of certain advanced scalar versus vector and conventional scalar ground motion intensity measures (IMs). One of the benefits of using a well-chosen IM is that more accurate evaluations of seismic performance are achieved without the need to perform detailed ground motion record selection for the nonlinear dynamic structural analyses involved in PSDA (e.g. record selection with respect to seismic parameters such as earthquake magnitude, source-to-site distance, and ground motion epsilon). For structural demands that are dominated by a first mode of vibration, using inelastic spectral displacement (Sdi) can be advantageous relative to the conventionally used elastic spectral acceleration (Sa) and the vector IM consisting of Sa and epsilon (??). This paper demonstrates that this is true for ordinary and for near-source pulse-like earthquake records. The latter ground motions cannot be adequately characterized by either Sa alone or the vector of Sa and ??. For structural demands with significant higher-mode contributions (under either of the two types of ground motions), even Sdi (alone) is not sufficient, so an advanced scalar IM that additionally incorporates higher modes is used.

  14. hal-00130116,version2-11Feb2007 Existence and uniqueness results for the Gradient Vector Flow

    E-print Network

    Paris-Sud XI, Université de

    .guillot@univ-orleans.fr, maitine.bergounioux@univ-orleans.fr Abstract This article deals with the so called GVF (Gradient Vector]. The model combines the geodesic active contour flow and the GVF to determine the geometric flow. The motion are interested in the Gradient Vector Flow (GVF) as a front propagation flow model. This model builds a class

  15. Vector representation of tourmaline compositions

    NASA Technical Reports Server (NTRS)

    Burt, Donald M.

    1989-01-01

    The vector method for representing mineral compositions of amphibole and mica groups is applied to the tourmaline group. Consideration is given to the methods for drawing the relevant vector diagrams, relating the exchange vectors to one another, and contouring the diagrams for constant values of Na, Ca, Li, Fe, Mg, Al, Si, and OH. The method is used to depict a wide range of possible tourmaline end-member compositions and solid solutions, starting from a single point. In addition to vector depictions of multicomponent natural tourmalines, vectors are presented for simpler systems such as (Na,Al)-tourmalines, alkali-free tourmalines, and elbaites.

  16. Cloud profiling radar for the CloudSat Mission

    NASA Technical Reports Server (NTRS)

    Im, Eastwood; Wu, Chialin; Durden, Stephen L.

    2005-01-01

    The CloudSat Mission is a new satellite mission jointly developed by NASA, JPL, the Canadian Agency, Colorado State University, and the US AirForce to acquire a global data set of vertical cloud structure and its variability.

  17. Cloud Based Applications and Platforms (Presentation)

    SciTech Connect

    Brodt-Giles, D.

    2014-05-15

    Presentation to the Cloud Computing East 2014 Conference, where we are highlighting our cloud computing strategy, describing the platforms on the cloud (including Smartgrid.gov), and defining our process for implementing cloud based applications.

  18. A novel cross-diamond search algorithm for fast block motion estimation

    Microsoft Academic Search

    Chun-ho Cheung; Lai-man Po

    2002-01-01

    In block motion estimation, search patterns with different shapes or sizes and the center-biased characteristics of motion-vector distribution have a large impact on the searching speed and quality of performance. In this paper, we propose a novel algorithm using a cross-search pattern as the initial step and large\\/small diamond search (DS) patterns as the subsequent steps for fast block motion

  19. Motion-oriented coding scheme for compression of concentric mosaic scene representations

    Microsoft Academic Search

    Kehua Jiang; Eric Dubois

    2004-01-01

    A motion-oriented coding scheme for compressing concentric mosaic representations is designed based on modifications to a standardized block-based hybrid video coding scheme. The motion features of the camera capturing the concentric mosaic representations are exploited to enhance the coding efficiency and improve the decoding flexibility. The coded data is organized in a hierarchical structure into a bitstream. Two-level motion vector

  20. Microphysics of Pyrocumulonimbus Clouds

    NASA Technical Reports Server (NTRS)

    Jensen, Eric; Ackerman, Andrew S.; Fridlind, Ann

    2004-01-01

    The intense heat from forest fires can generate explosive deep convective cloud systems that inject pollutants to high altitudes. Both satellite and high-altitude aircraft measurements have documented cases in which these pyrocumulonimbus clouds inject large amounts of smoke well into the stratosphere (Fromm and Servranckx 2003; Jost et al. 2004). This smoke can remain in the stratosphere, be transported large distances, and affect lower stratospheric chemistry. In addition recent in situ measurements in pyrocumulus updrafts have shown that the high concentrations of smoke particles have significant impacts on cloud microphysical properties. Very high droplet number densities result in delayed precipitation and may enhance lightning (Andrew et al. 2004). Presumably, the smoke particles will also lead to changes in the properties of anvil cirrus produces by the deep convection, with resulting influences on cloud radiative forcing. In situ sampling near the tops of mature pyrocumulonimbus is difficult due to the high altitude and violence of the storms. In this study, we use large eddy simulations (LES) with size-resolved microphysics to elucidate physical processes in pyrocumulonimbus clouds.

  1. Counting the clouds

    NASA Astrophysics Data System (ADS)

    Randall, David A.

    2005-01-01

    Cloud processes are very important for the global circulation of the atmosphere. It is now possible, though very expensive, to simulate the global circulation of the atmosphere using a model with resolution fine enough to explicitly represent the larger individual clouds. An impressive preliminary calculation of this type has already been performed by Japanese scientists, using the Earth Simulator. Within the next few years, such global cloud-resolving models (GCRMs) will be applied to weather prediction, and later they will be used in climatechange simulations. The tremendous advantage of GCRMs, relative to conventional lowerresolution global models, is that GCRMs can avoid many of the questionable "parameterizations" used to represent cloud effects in lower-resolution global models. Although cloud microphysics, turbulence, and radiation must still be parameterized in GCRMs, the high resolution of a GCRM simplifies these problems considerably, relative to conventional models. The United States currently has no project to develop a GCRM, although we have both the computer power and the expertise to do it. A research program aimed at development and applications of GCRMs is outlined.

  2. Science Report: Atmosphere A Comparison of Satellite-Based Cloud Observations to GLOBE Cloud Observations using the MODIS Cloud Product

    Microsoft Academic Search

    Matt Rogers; Graeme Stephens

    GLOBE student observations of cloud type are compared to coincident satellite-derived observations, using MODIS Cloud Product data from the EOS-PM satellite. Cloud type is computed using satellite observed cloud top pressure and cloud optical thickness in the framework of the ISCCP cloud classification scheme (Rossow and Schiffer, 1991.) Common errors and biases in the surface based observations are explored, with

  3. ETSI CLOUD - Initial Standardization Requirements for Cloud Services

    Microsoft Academic Search

    Karsten Oberle; Mike Fisher

    2010-01-01

    \\u000a While the technological basis for cloud services is relatively mature, the development of the market is still at an early\\u000a stage. There is considerable potential, but also a number of widely held concerns which are inhibiting mainstream adoption\\u000a of cloud services by business. This paper is based on the outcome of the ETSI TC CLOUD Workshop, “Grids, Clouds and Service

  4. Reconstruction of cloud geometry using a scanning cloud radar

    NASA Astrophysics Data System (ADS)

    Ewald, F.; Winkler, C.; Zinner, T.

    2015-06-01

    Clouds are one of the main reasons of uncertainties in the forecasts of weather and climate. In part, this is due to limitations of remote sensing of cloud microphysics. Present approaches often use passive spectral measurements for the remote sensing of cloud microphysical parameters. Large uncertainties are introduced by three-dimensional (3-D) radiative transfer effects and cloud inhomogeneities. Such effects are largely caused by unknown orientation of cloud sides or by shadowed areas on the cloud. Passive ground-based remote sensing of cloud properties at high spatial resolution could be crucially improved with this kind of additional knowledge of cloud geometry. To this end, a method for the accurate reconstruction of 3-D cloud geometry from cloud radar measurements is developed in this work. Using a radar simulator and simulated passive measurements of model clouds based on a large eddy simulation (LES), the effects of different radar scan resolutions and varying interpolation methods are evaluated. In reality, a trade-off between scan resolution and scan duration has to be found as clouds change quickly. A reasonable choice is a scan resolution of 1 to 2°. The most suitable interpolation procedure identified is the barycentric interpolation method. The 3-D reconstruction method is demonstrated using radar scans of convective cloud cases with the Munich miraMACS, a 35 GHz scanning cloud radar. As a successful proof of concept, camera imagery collected at the radar location is reproduced for the observed cloud cases via 3-D volume reconstruction and 3-D radiative transfer simulation. Data sets provided by the presented reconstruction method will aid passive spectral ground-based measurements of cloud sides to retrieve microphysical parameters.

  5. Cloud Statistics Measured With the Infrared Cloud Imager (ICI)

    Microsoft Academic Search

    Brentha Thurairajah; Joseph A. Shaw

    2005-01-01

    The Infrared Cloud Imager (ICI) is a ground-based thermal infrared imaging system that measures spatial cloud statistics with a 320$,times,$240-pixel uncooled microbolometer detector array. Clouds are identified from the residual radiance that remains after water vapor emission is removed from radiometrically calibrated sky images (the water vapor correction relies on measurements of precipitable water vapor and near-surface air temperature). Cloud

  6. Effects of turbulence on the collision rate of cloud droplets

    NASA Astrophysics Data System (ADS)

    Ayala, Orlando

    This dissertation concerns effects of air turbulence on the collision rate of atmospheric cloud droplets. This research was motivated by the speculation that air turbulence could enhance the collision rate thereby help transform cloud droplets to rain droplets in a short time as observed in nature. The air turbulence within clouds is assumed to be homogeneous and isotropic, and its small-scale motion (1 mm to 10 cm scales) is computationally generated by direct numerical integration of the full Navier-Stokes equations. Typical droplet and turbulence parameters of convective warm clouds are used to determine the Stokes numbers (St) and the nondimensional terminal velocities (Sv) which characterize droplet relative inertia and gravitational settling, respectively. A novel and efficient methodology for conducting direct numerical simulations (DNS) of hydrodynamically-interacting droplets in the context of cloud microphysics has been developed. This numerical approach solves the turbulent flow by the pseudo-spectral method with a large-scale forcing, and utilizes an improved superposition method to embed analytically the local, small-scale (10 mum to 1 mm) disturbance flows induced by the droplets. This hybrid representation of background turbulent air motion and the induced disturbance flows is then used to study the combined effects of hydrodynamic interactions and airflow turbulence on the motion and collisions of cloud droplets. Hybrid DNS results show that turbulence can increase the geometric collision kernel relative to the gravitational geometric kernel by as much as 42% due to enhanced radial relative motion and preferential concentration of droplets. The exact level of enhancements depends on the Taylor-microscale Reynolds number, turbulent dissipation rate, and droplet pair size ratio. One important finding is that turbulence has a relatively dominant effect on the collision process between droplets close in size as the gravitational collision mechanism diminishes. A theory was developed to predict the radial relative velocity between droplets at contact. The theory agrees with our DNS results to within 5% for cloud droplets with strong settling. In addition, an empirical model is developed to quantify the radial distribution function. (Abstract shortened by UMI.)

  7. Self-motion perception in the elderly

    PubMed Central

    Lich, Matthias; Bremmer, Frank

    2014-01-01

    Self-motion through space generates a visual pattern called optic flow. It can be used to determine one's direction of self-motion (heading). Previous studies have already shown that this perceptual ability, which is of critical importance during everyday life, changes with age. In most of these studies subjects were asked to judge whether they appeared to be heading to the left or right of a target. Thresholds were found to increase continuously with age. In our current study, we were interested in absolute rather than relative heading judgments and in the question about a potential neural correlate of an age-related deterioration of heading perception. Two groups, older test subjects and younger controls, were shown optic flow stimuli in a virtual-reality setup. Visual stimuli simulated self-motion through a 3-D cloud of dots and subjects had to indicate their perceived heading direction after each trial. In different subsets of experiments we varied individually relevant stimulus parameters: presentation time, number of dots in the display, stereoscopic vs. non-stereoscopic stimulation, and motion coherence. We found decrements in heading performance with age for each stimulus parameter. In a final step we aimed to determine a putative neural basis of this behavioral decline. To this end we modified a neural network model which previously has proven to be capable of reproduce and predict certain aspects of heading perception. We show that the observed data can be modeled by implementing an age related neuronal cell loss in this neural network. We conclude that a continuous decline of certain aspects of motion perception, among them heading, might be based on an age-related progressive loss of groups of neurons being activated by visual motion. PMID:25309379

  8. THE REMARKABLE HIGH PRESSURE OF THE LOCAL LEO COLD CLOUD

    SciTech Connect

    Meyer, David M. [Center for Interdisciplinary Exploration and Research in Astrophysics, Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States); Lauroesch, J. T. [Department of Physics and Astronomy, University of Louisville, Louisville, KY 40292 (United States); Peek, J. E. G. [Department of Astronomy, Columbia University, Pupin Physics Laboratories, 550 West 120th Street, New York, NY 10027 (United States); Heiles, Carl, E-mail: davemeyer@northwestern.edu, E-mail: jtlaur01@louisville.edu, E-mail: goldston@gmail.com, E-mail: heiles@astro.berkeley.edu [Department of Astronomy, University of California, Berkeley, 601 Campbell Hall, Berkeley, CA 94720 (United States)

    2012-06-20

    Using the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope, we have obtained high-resolution ultraviolet spectra of the C I absorption toward two stars behind the Local Leo Cold Cloud (LLCC). At a distance ( Almost-Equal-To 20 pc) that places it well inside the Local Bubble, the LLCC is the nearest example of the coldest known (T Almost-Equal-To 20 K) diffuse interstellar clouds. The STIS measurements of the C I fine-structure excitation toward HD 85259 and HD 83023 indicate that the thermal gas pressure of the LLCC is much greater than that of the warm clouds in the Local Bubble. The mean LLCC pressure measured toward these two stars (60,000 cm{sup -3} K) implies an H I density of Almost-Equal-To 3000 cm{sup -3} and a cloud thickness of Almost-Equal-To 200 AU at the 20 K cloud temperature. Such a thin, cold, dense structure could arise at the collision interface between converging flows of warm gas. However, the measured LLCC pressure is appreciably higher than that expected in the colliding-cloud interpretation given the velocity and column density constraints on warm clouds in the HD 85259 and HD 83023 sightlines. Additional STIS measurements of the Zn II, Ni II, and Cr II column densities toward HD 85259 indicate that the LLCC has a modest 'warm cloud' dust depletion pattern consistent with its low dust-to-gas ratio determined from H I 21 cm and 100 {mu}m observations. In support of the inferred sheet-like geometry for the LLCC, a multi-epoch comparison of the Na I absorption toward a high-proper-motion background star reveals a 40% column density variation indicative of LLCC Na I structure on a scale of Almost-Equal-To 50 AU.

  9. Capture of field stars by giant interstellar clouds: the formation of moving stellar groups

    NASA Astrophysics Data System (ADS)

    Olano, C. A.

    2015-03-01

    In the solar neighbourhood, there are moving groups of stars with similar ages and others of stars with heterogeneous ages as the field stars. To explain these facts, we have constructed a simple model of three phases. Phase A: a giant interstellar cloud is uniformly accelerated (or decelerated) with respect to the field stars during a relatively short period of time (10 Myr) and the cloud's mass is uniformly increased. As a result, a number of passing field stars is gravitationally captured by the cloud at the end of this phase; phase B: the acceleration (or deceleration) and mass accretion of the cloud cease. The star formation spreads throughout the cloud, giving origin to stellar groups of similar ages; and phase C: the cloud loses all its gaseous component at a constant rate and in parallel is uniformly decelerated (or accelerated) until reaching the initial velocity of phase A (case 1) or the velocity of the gas cloud remains constant (case 2). Both cases give equivalent results. The system equations for the star motions governed by a time-dependent gravitational potential of the giant cloud and referred to a coordinate system comoving with the cloud have been solved analytically. We have assumed a homogeneous spheroidal cloud of fixed semimajor axis a = 300 pc and of an initial density of 7 atoms cm- 3, with a density increment of 100 per cent and a cloud's velocity variation of 30 km s-1, from the beginning to the end of phase A. The result is that about 4 per cent of the field stars that are passing within the volume of the cloud at the beginning of phase A are captured. The Sun itself could have been captured by the same cloud that originated the moving groups of the solar neighbourhood.

  10. EDITORIAL: Focus on Cloud Physics FOCUS ON CLOUD PHYSICS

    Microsoft Academic Search

    Gregory Falkovich; Szymon P. Malinowski

    2008-01-01

    Cloud physics has for a long time been an important segment of atmospheric science. It is common knowledge that clouds are crucial for our understanding of weather and climate. Clouds are also interesting by themselves (not to mention that they are beautiful). Complexity is hidden behind the common picture of these beautiful and interesting objects. The typical school textbook definition

  11. Cloud Hooks: Security and Privacy Issues in Cloud Computing

    Microsoft Academic Search

    Wayne A. Jansen

    2011-01-01

    In meteorology, the most destructive extratropical cyclones evolve with the formation of a bent-back front and cloud head separated from the main polar-front, creating a hook that completely encircles a pocket of warm air with colder air. The most damaging winds occur near the tip of the hook. The cloud hook formation provides a useful analogy for cloud computing, in

  12. Cloud structure and crystal growth in nimbostratus clouds. Mengistu Wolde*

    E-print Network

    Vali, Gabor

    1 Cloud structure and crystal growth in nimbostratus clouds. Mengistu Wolde* , Gabor Vali-mail: mengistu.wolde@nrc.ca. #12;2 Abstract Cloud structure and crystal growth in two nimbostratus were examined made available by large scale lifting was taken up by depositional growth of the ice crystals

  13. Cloud cover analysis with Arctic AVHRR data 1. Cloud detection

    Microsoft Academic Search

    R. G. Barry

    1989-01-01

    Automated analyses of satellite radiance data have concentrated heavily on low and middle situations. Some of the design objectives for the International Satellite Cloud Climatology Project (ISCCP) cloud detection procedure such as space and time contrasts are used in a basic algorithm from which a polar cloud detection algorithm is developed. This algorithm is applied to Arctic data for January

  14. CLOUD WATER CHEMISTRY AND THE PRODUCTION OF SULFATES IN CLOUDS

    EPA Science Inventory

    Measurements are presented of the pH and ionic content of water collected in clouds over Western Washington and the Los Angeles Basin. Evidence for sulfate production in some of the clouds is presented. Not all of the sulfur in the cloud water was in the form of sulfate. However,...

  15. On the use of IR lidar and K(sub a)-band radar for observing cirrus clouds

    NASA Technical Reports Server (NTRS)

    Eberhard, Wynn L.; Hardesty, R. Michael; Kropfli, Robert A.

    1990-01-01

    Advances in lidar and radar technology have potential for providing new and better information on climate significant parameters of cirrus. Consequently, the NOAA Wave Propagation Lab. is commencing CLARET (Cloud Lidar And Radar Exploratory Test) to evaluate the promise of these new capabilities. Parameters under study include cloud particle size distribution, height of cloud bases, tops, and multiple layers, and cloud dynamics revealed through measurement of vertical motions. The first phase of CLARET is planned for Sept. 1989. The CO2 coherent Doppler lidar and the sensitive K sub a band radar hold promise for providing valuable information on cirrus that is beyond the grasp of current visible lidars.

  16. DAVID: A new video motion sensor for outdoor perimeter applications

    SciTech Connect

    Alexander, J.C.

    1986-01-01

    To be effective, a perimeter intrusion detection system must comprise both sensor and rapid assessment components. The use of closed circuit television (CCTV) to provide the rapid assessment capability, makes possible the use of video motion detection (VMD) processing as a system sensor component. Despite it's conceptual appeal, video motion detection has not been widely used in outdoor perimeter systems because of an inability to discriminate between genuine intrusions and numerous environmental effects such as cloud shadows, wind motion, reflections, precipitation, etc. The result has been an unacceptably high false alarm rate and operator work-load. DAVID (Digital Automatic Video Intrusion Detector) utilizes new digital signal processing techniques to achieve a dramatic improvement in discrimination performance thereby making video motion detection practical for outdoor applications. This paper begins with a discussion of the key considerations in implementing an outdoor video intrusion detection system, followed by a description of the DAVID design in light of these considerations.

  17. Canonical active Brownian motion

    E-print Network

    Alexander Gluck; Helmuth Huffel; Sasa Ilijic

    2008-12-17

    Active Brownian motion is the complex motion of active Brownian particles. They are active in the sense that they can transform their internal energy into energy of motion and thus create complex motion patterns. Theories of active Brownian motion so far imposed couplings between the internal energy and the kinetic energy of the system. We investigate how this idea can be naturally taken further to include also couplings to the potential energy, which finally leads to a general theory of canonical dissipative systems. Explicit analytical and numerical studies are done for the motion of one particle in harmonic external potentials. Apart from stationary solutions, we study non-equilibrium dynamics and show the existence of various bifurcation phenomena.

  18. Two novel motion-based algorithms for surveillance video analysis on embedded platforms

    NASA Astrophysics Data System (ADS)

    Vijverberg, Julien A.; Loomans, Marijn J. H.; Koeleman, Cornelis J.; de With, Peter H. N.

    2010-05-01

    This paper proposes two novel motion-vector based techniques for target detection and target tracking in surveillance videos. The algorithms are designed to operate on a resource-constrained device, such as a surveillance camera, and to reuse the motion vectors generated by the video encoder. The first novel algorithm for target detection uses motion vectors to construct a consistent motion mask, which is combined with a simple background segmentation technique to obtain a segmentation mask. The second proposed algorithm aims at multi-target tracking and uses motion vectors to assign blocks to targets employing five features. The weights of these features are adapted based on the interaction between targets. These algorithms are combined in one complete analysis application. The performance of this application for target detection has been evaluated for the i-LIDS sterile zone dataset and achieves an F1-score of 0.40-0.69. The performance of the analysis algorithm for multi-target tracking has been evaluated using the CAVIAR dataset and achieves an MOTP of around 9.7 and MOTA of 0.17-0.25. On a selection of targets in videos from other datasets, the achieved MOTP and MOTA are 8.8-10.5 and 0.32-0.49 respectively. The execution time on a PC-based platform is 36 ms. This includes the 20 ms for generating motion vectors, which are also required by the video encoder.

  19. The Local Stellar Velocity Field via Vector Spherical Harmonics

    NASA Technical Reports Server (NTRS)

    Makarov, V. V.; Murphy, D. W.

    2007-01-01

    We analyze the local field of stellar tangential velocities for a sample of 42,339 nonbinary Hipparcos stars with accurate parallaxes, using a vector spherical harmonic formalism.We derive simple relations between the parameters of the classical linear model (Ogorodnikov-Milne) of the local systemic field and low-degree terms of the general vector harmonic decomposition. Taking advantage of these relationships, we determine the solar velocity with respect to the local stars of (V(sub X), V(sub Y), V(sub Z)) = (10.5, 18.5, 7.3) +/- 0.1 km s(exp -1) not for the asymmetric drift with respect to the local standard of rest. If only stars more distant than 100 pc are considered, the peculiar solar motion is (V(sub X), V(sub Y), V(sub Z)) = (9.9, 15.6, 6.9) +/- 0.2 km s(exp -1). The adverse effects of harmonic leakage, which occurs between the reflex solar motion represented by the three electric vector harmonics in the velocity space and higher degree harmonics in the proper-motion space, are eliminated in our analysis by direct subtraction of the reflex solar velocity in its tangential components for each star...

  20. DocumentCloud

    NSDL National Science Digital Library

    Cloud computing is gaining currency, and this new project is just one of the many initiatives that will make people sit up and take notice. The Document Cloud nonprofit began in 2009 with funds from the Knight News Challenge, and the idea behind the group is that journalists, researchers, and archivists can use the DocumentCloud workspace to upload documents, share them with teams of colleagues, and also conduct structured searches and analyses based on extracted entities (also known as the people, places, and organizations mentioned in the text). The group is in the process of releasing some of their work as open-source projects, and visitors can use the "FAQ" area to learn more about these projects. The site also includes a blog, a "Latest Updates" area, and profiles of the founders over at "Who We Are". [KMG

  1. Making clouds in Spacelab

    NASA Technical Reports Server (NTRS)

    Duncan, C.

    1978-01-01

    Improvements in the accuracy of weather predictions and possibilities for changing the weather might depend on a better understanding of the microphysical processes which take place within clouds. A study of these processes on the surface of the earth is difficult in connection with gravitational disturbances. An Atmospheric Cloud Physics Laboratory (ACPL), which is currently being developed, is to be carried into space in the Spacelab in the early 1980's. This facility will provide scientists, for the first time, with the opportunity to study cloud physics without the disturbing gravitational effects. In the ACPL facility, a microscopic element can be suspended without support. The processes of freezing, thawing, collision, electric charging, and temperature changes can be observed and photographed as many times and for as long as necessary.

  2. Photolevitation of diffuse clouds

    SciTech Connect

    Franco, J.; Ferrini, F.; Barsella, B.; Ferrara, A. (Universidad Nacional Autonoma de Mexico, Coyoacan (Mexico) Max-Planck-Institut fuer Astrophysik, Garching (Germany, F.R.) Pisa Universita (Italy) Firenze Universita, Florence (Italy))

    1991-01-01

    Radiation pressure on dust grains can raise small dusty clouds above the main gaseous disk to high Galactic latitudes. This photolevitation effect drives neutral gas and dust into a soft Galactic fountain and can maintain a column density of the order of 10 to the 20th/sq cm above the main gaseous disk. This value is defined by dust opacity and corresponds to a normal dust-to-gas ratio with cosmic abundances. The maximum height reached by the photolevitated clouds depends on the radiation field and dust-to-gas ratios. Clouds located above luminous stellar clusters or near spiral arms with intense star formation can reach several hundred parsecs in height. 56 refs.

  3. Beating the Motion Sensor

    NSDL National Science Digital Library

    2014-09-18

    Lighting is responsible for nearly one-third of the electricity use in buildings. One of the best ways to conserve energy is to make sure the lights are turned off when no one is in a room. This process can be automated using motion sensors. In this activity, students explore material properties as they relate to motion detection, and use that knowledge to make design judgments about what types of motion detectors to use in specific applications.

  4. Motion in Quantum Gravity

    E-print Network

    Karim Noui

    2010-03-31

    We tackle the question of motion in Quantum Gravity: what does motion mean at the Planck scale? Although we are still far from a complete answer we consider here a toy model in which the problem can be formulated and resolved precisely. The setting of the toy model is three dimensional Euclidean gravity. Before studying the model in detail, we argue that Loop Quantum Gravity may provide a very useful approach when discussing the question of motion in Quantum Gravity.

  5. Vector Spaces and Linear Transformations Beifang Chen

    E-print Network

    Chen, Beifang

    Vector Spaces and Linear Transformations Beifang Chen Fall 2006 1 Vector spaces A vector space is a nonempty set V , whose objects are called vectors, equipped with two operations, called addition and scalar multiplication: For any two vectors u, v in V and a scalar c, there are unique vectors u + v and cu in V

  6. Satellite-viewed cloud signatures associated with extratropical cyclogenesis 

    E-print Network

    Lapierre, Robert Lucien

    1973-01-01

    were analyzed for 14 cases of extratropical cyclogenesis. Cyclone models, which had been proposed previously for extratropical cyclogenesis based on satellite data, were studied for potential parameters that could aid in forecasting surface... meteorological satellites has provided a real-time means for the early detection of extratropical cyclogenesis, and the subsequent development of these cyclones. The presence of clouds indicates general areas of upward vertical motions. Good agreement has...

  7. Diagnosing Warm Frontal Cloud Formation in a GCM: A Novel Approach Using Conditional Subsetting

    NASA Technical Reports Server (NTRS)

    Booth, James F.; Naud, Catherine M.; DelGenio, Anthony D.

    2013-01-01

    This study analyzes characteristics of clouds and vertical motion across extratropical cyclone warm fronts in the NASA Goddard Institute for Space Studies general circulation model. The validity of the modeled clouds is assessed using a combination of satellite observations from CloudSat, Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E), and the NASA Modern-Era Retrospective Analysis for Research and Applications (MERRA) reanalysis. The analysis focuses on developing cyclones, to test the model's ability to generate their initial structure. To begin, the extratropical cyclones and their warm fronts are objectively identified and cyclone-local fields are mapped into a vertical transect centered on the surface warm front. To further isolate specific physics, the cyclones are separated using conditional subsetting based on additional cyclone-local variables, and the differences between the subset means are analyzed. Conditional subsets are created based on 1) the transect clouds and 2) vertical motion; 3) the strength of the temperature gradient along the warm front, as well as the storm-local 4) wind speed and 5) precipitable water (PW). The analysis shows that the model does not generate enough frontal cloud, especially at low altitude. The subsetting results reveal that, compared to the observations, the model exhibits a decoupling between cloud formation at high and low altitudes across warm fronts and a weak sensitivity to moisture. These issues are caused in part by the parameterized convection and assumptions in the stratiform cloud scheme that are valid in the subtropics. On the other hand, the model generates proper covariability of low-altitude vertical motion and cloud at the warm front and a joint dependence of cloudiness on wind and PW.

  8. Ash cloud aviation advisories

    SciTech Connect

    Sullivan, T.J.; Ellis, J.S. [Lawrence Livermore National Lab., CA (United States); Schalk, W.W.; Nasstrom, J.S. [EG and G, Inc., Pleasanton, CA (United States)

    1992-06-25

    During the recent (12--22 June 1991) Mount Pinatubo volcano eruptions, the US Air Force Global Weather Central (AFGWC) requested assistance of the US Department of Energy`s Atmospheric Release Advisory Capability (ARAC) in creating volcanic ash cloud aviation advisories for the region of the Philippine Islands. Through application of its three-dimensional material transport and diffusion models using AFGWC meteorological analysis and forecast wind fields ARAC developed extensive analysis and 12-hourly forecast ash cloud position advisories extending to 48 hours for a period of five days. The advisories consisted of ``relative`` ash cloud concentrations in ten layers (surface-5,000 feet, 5,000--10,000 feet and every 10,000 feet to 90,000 feet). The ash was represented as a log-normal size distribution of 10--200 {mu}m diameter solid particles. Size-dependent ``ashfall`` was simulated over time as the eruption clouds dispersed. Except for an internal experimental attempt to model one of the Mount Redoubt, Alaska, eruptions (12/89), ARAC had no prior experience in modeling volcanic eruption ash hazards. For the cataclysmic eruption of 15--16 June, the complex three-dimensional atmospheric structure of the region produced dramatically divergent ash cloud patterns. The large eruptions (> 7--10 km) produced ash plume clouds with strong westward transport over the South China Sea, Southeast Asia, India and beyond. The low-level eruptions (< 7 km) and quasi-steady-state venting produced a plume which generally dispersed to the north and east throughout the support period. Modeling the sequence of eruptions presented a unique challenge. Although the initial approach proved viable, further refinement is necessary and possible. A distinct need exists to quantify eruptions consistently such that ``relative`` ash concentrations relate to specific aviation hazard categories.

  9. Royal Meteorological Society 1 INTRODUCTION TO CLOUDS

    E-print Network

    Allan, Richard P.

    1 © Royal Meteorological Society 1 INTRODUCTION TO CLOUDS · Clouds are very common, with 50% of Earth covered in cloud at any one time. · Only 1 ­ 2% will be raining. · They are classified by height and nature: - Low clouds: base 0 ­ 2 km - Medium clouds: base 2 ­ 7 km - High clouds: base above 5 km Over

  10. Cloud Computing: System Instances and Current Research

    Microsoft Academic Search

    CHEN Kang; ZHENG Wei-Min

    2009-01-01

    This paper surveys the current technologies adopted in cloud computing as well as the systems in enterprises. Cloud computing can be viewed from two different aspects. One is about the cloud infrastructure which is the building block for the up layer cloud application. The other is of course the cloud application. This paper focuses on the cloud infrastructure including the

  11. Vectoring: Steering a Plane

    NSDL National Science Digital Library

    2011-08-20

    In this two part activity, learners work in pairs or individually to discover how vectoring the thrust from a jet engine affects movement of an airplane. In part one, learners construct an F-15 ACTIVE model with a balloon engine. In part two, learners conduct a series of experiments by changing the angle of the straw to control the direction of the thrust. This activity emphasizes the scientific method including prediction, observation, data collection, and analysis. This lesson plan includes background information, an extension and a sample worksheet.

  12. Motion Estimation Using the Firefly Algorithm in Ultrasonic Image Sequence of Soft Tissue

    PubMed Central

    Chao, Chih-Feng; Horng, Ming-Huwi; Chen, Yu-Chan

    2015-01-01

    Ultrasonic image sequence of the soft tissue is widely used in disease diagnosis; however, the speckle noises usually influenced the image quality. These images usually have a low signal-to-noise ratio presentation. The phenomenon gives rise to traditional motion estimation algorithms that are not suitable to measure the motion vectors. In this paper, a new motion estimation algorithm is developed for assessing the velocity field of soft tissue in a sequence of ultrasonic B-mode images. The proposed iterative firefly algorithm (IFA) searches for few candidate points to obtain the optimal motion vector, and then compares it to the traditional iterative full search algorithm (IFSA) via a series of experiments of in vivo ultrasonic image sequences. The experimental results show that the IFA can assess the vector with better efficiency and almost equal estimation quality compared to the traditional IFSA method. PMID:25873987

  13. Polar Stratospheric Clouds from SOLVE

    NSDL National Science Digital Library

    George Fekete

    2000-05-30

    Polar stratospheric clouds form at extremely low temperatures in the upper atmosphere. Should the temperature rise, clouds wont form. In this visualization, sequential temperature readings taken in the research area for SOLVE (Stratospheric Ozone Loss and Validation Experiment) are plotted against a threshold temperature for PSC formation. These are clouds essentially made of nitric acid. Note how the area covered by the clouds increases as winter progresses. The red point on the map indicates the location of Kiruna, Sweden, the SOLVE staging area.

  14. Cloud Computing: a Perspective Study

    Microsoft Academic Search

    Lizhe WANG; Gregor VON LASZEWSKI; Marcel KUNZE; Jie TAO; Germany Eggenstein-Leopoldshafen

    2008-01-01

    The Cloud computing emerges as a new computing paradigm which aims to provide reliable, customized and QoS guaranteed dynamic computing environments for end-users. In this paper, we study the Cloud computing paradigm from various aspects, such as definitions, distinct features, and enabling technologies. This paper brings an introductional review on the Cloud computing and provide the state-of-the-art of Cloud computing

  15. Cloud Computing: a Perspective Study

    Microsoft Academic Search

    Lizhe Wang; Gregor von Laszewski; Andrew J. Younge; Xi He; Marcel Kunze; Jie Tao; Cheng Fu

    2010-01-01

    The Cloud computing emerges as a new computing paradigm which aims to provide reliable, customized and QoS guaranteed dynamic\\u000a computing environments for end-users. In this paper, we study the Cloud computing paradigm from various aspects, such as definitions,\\u000a distinct features, and enabling technologies. This paper brings an introductional review on the Cloud computing and provides\\u000a the state-of-the-art of Cloud computing

  16. Supersonic cloud collision. I.

    NASA Astrophysics Data System (ADS)

    Anathpindika, S.

    2009-09-01

    Context: It has long been suggested that shocks might play an important role in altering the form of the interstellar medium (ISM). Shocks enhance gas density and sufficiently dense regions may become self gravitating. Potential star-forming clouds within larger molecular clouds, move randomly at supersonic speeds and a collision between them, is highly inelastic. Aims: Depending on the precollision velocity, colliding molecular clouds produce a slab that is either shock-compressed or pressure-confined. In a sequel of two Papers (I and II), we simulate molecular cloud collision and investigate the dynamical evolution of such slabs. Shocked slabs appear susceptible to hydrodynamic instabilities and, in the present Paper (I), we study the effect of strong shear between slab layers on the dynamic evolution of a shock compressed gas slab. Head-on and off-centre cloud collisions have been examined in this work. Self gravity is included in all our simulations. Methods: Simulations presented were performed using the smoothed particle hydrodynamics (SPH) numerical scheme. Individual, precollision clouds are modelled as pressure-confined Bonnor-Ebert spheres. However, for simplicity the thermodynamic details of the problem are simplified and the gas temperature is evolved simply by a barytropic equation of state. Obviously, the gas suffers to some extent from thermal inertial effects. However, we note that the dynamical timescale is much smaller than the local sound crossing time so that any such effects should have minimum influence. Results: Strong shocks are highly radiative. Thus a highly supersonic cloud collision produces a cold, roughly isothermal shock compressed gas slab. We find that the shocked slab is susceptible to dynamical instabilities like the gravitational instability, Kelvin-Helmholtz (KH) instability and the non linear thin shell instability (NTSI). Rapid growth of instabilities within the slab produces structure in it. The NTSI competes with the gravitational instability and the fate of the shocked slab apparently depends on the relative dominance of either of the two instabilities. Dominance of the NTSI causes turbulent mixing between slab layers and dissipates internal energy. Eventually the slab collapses to form a thin elongated body, aligned with the collision axis, and star formation may commence in it. Our hydrodynamical models discussed here suggest that, high-velocity cloud collisions may be a viable mechanism for the formation of observed filamentary structure in the ISM.

  17. Clouds, A Teaching Box

    NSDL National Science Digital Library

    SPARK

    2014-04-04

    Explore the educational resources in this teaching box and bring cloud science to your elementary students. The science of clouds helps students feel closer to the sky and in awe of nature as they learn elementary concepts of physics, the water cycle, and atmospheric science. Teaching Boxes are themed collections of classroom-ready educational resources to build student understanding of science, technology, engineering, and math (STEM). Resources highlighted within teaching boxes are from various science education programs and have been vetted by UCAR educators.

  18. In the Clouds Photography

    NSDL National Science Digital Library

    Gregory Thompson

    2000-01-01

    In the Clouds Photography specializes in photos of weather skyscapes taken by a photographer who is also an atmospheric scientist. Spectacular images of tornadoes, lightning, supercells, and other related severe weather are available, as are weather photos of a less severe nature;strange cloud forms and optical phenomenon such as rainbows, halos, and glories. Weather-related photos are a specialty but this web site also contains galleries that generally fit within the Landscape, Nature, and Travel photo themes with hundreds of photos of mountain scenes, flowers, trees, etc. Use the site's Search function for specific topics or simply peruse the Gallery.

  19. Opaque cloud detection

    DOEpatents

    Roskovensky, John K. (Albuquerque, NM)

    2009-01-20

    A method of detecting clouds in a digital image comprising, for an area of the digital image, determining a reflectance value in at least three discrete electromagnetic spectrum bands, computing a first ratio of one reflectance value minus another reflectance value and the same two values added together, computing a second ratio of one reflectance value and another reflectance value, choosing one of the reflectance values, and concluding that an opaque cloud exists in the area if the results of each of the two computing steps and the choosing step fall within three corresponding predetermined ranges.

  20. Impact of Short Interval SMS Digital Data on Wind Vector Determination for a Severe Local Storms Area

    NASA Technical Reports Server (NTRS)

    Peslen, C. A.

    1979-01-01

    The impact of 5 minute interval SMS-2 visible digital image data in analyzing severe local storms is examined using wind vectors derived from cloud tracking on time lapsed sequence of geosynchronous satellite images. The cloud tracking areas are located in the Central Plains, where on 6 May 1975, hail-producing thunderstorms occurred ahead of a well defined dry line. The results demonstrate that satellite-derived wind vectors and their associated divergence fields complement conventional meteorological analyses in describing the conditions preceding severe local storm development.