WorldWideScience

Sample records for surf scoter melanitta

  1. Composition, Shell Strength, and Metabolizable Energy of Mulinia lateralis and Ischadium recurvum as Food for Wintering Surf Scoters (Melanitta perspicillata.

    Directory of Open Access Journals (Sweden)

    Alicia M Wells-Berlin

    Full Text Available Decline in surf scoter (Melanitta perspicillata waterfowl populations wintering in the Chesapeake Bay has been associated with changes in the availability of benthic bivalves. The Bay has become more eutrophic, causing changes in the benthos available to surf scoters. The subsequent decline in oyster beds (Crassostrea virginica has reduced the hard substrate needed by the hooked mussel (Ischadium recurvum, one of the primary prey items for surf scoters, causing the surf scoter to switch to a more opportune species, the dwarf surfclam (Mulinia lateralis. The composition (macronutrients, minerals, and amino acids, shell strength (N, and metabolizable energy (kJ of these prey items were quantified to determine the relative foraging values for wintering scoters. Pooled samples of each prey item were analyzed to determine composition. Shell strength (N was measured using a shell crack compression test. Total collection digestibility trials were conducted on eight captive surf scoters. For the prey size range commonly consumed by surf scoters (6-12 mm for M. lateralis and 18-24 mm for I. recurvum, I. recurvum contained higher ash, protein, lipid, and energy per individual organism than M. lateralis. I. recurvum required significantly greater force to crack the shell relative to M. lateralis. No difference in metabolized energy was observed for these prey items in wintering surf scoters, despite I. recurvum's higher ash content and harder shell than M. lateralis. Therefore, wintering surf scoters were able to obtain the same amount of energy from each prey item, implying that they can sustain themselves if forced to switch prey.

  2. Composition, shell strength, and metabolizable energy of Mulinia lateralis and Ischadium recurvum as food for wintering surf scoters (Melanitta perspicillata)

    Science.gov (United States)

    Berlin, Alicia; Perry, Matthew; Kohn, R.A.; Paynter, K.T.; Ottinger, Mary Ann

    2015-01-01

    Decline in surf scoter (Melanitta perspicillata) waterfowl populations wintering in the Chesapeake Bay has been associated with changes in the availability of benthic bivalves. The Bay has become more eutrophic, causing changes in the benthos available to surf scoters. The subsequent decline in oyster beds (Crassostrea virginica) has reduced the hard substrate needed by the hooked mussel (Ischadium recurvum), one of the primary prey items for surf scoters, causing the surf scoter to switch to a more opportune species, the dwarf surfclam (Mulinia lateralis). The composition (macronutrients, minerals, and amino acids), shell strength (N), and metabolizable energy (kJ) of these prey items were quantified to determine the relative foraging values for wintering scoters. Pooled samples of each prey item were analyzed to determine composition. Shell strength (N) was measured using a shell crack compression test. Total collection digestibility trials were conducted on eight captive surf scoters. For the prey size range commonly consumed by surf scoters (6-12 mm for M. lateralis and 18-24 mm for I. recurvum), I. recurvum contained higher ash, protein, lipid, and energy per individual organism than M. lateralis. I. recurvum required significantly greater force to crack the shell relative to M. lateralis. No difference in metabolized energy was observed for these prey items in wintering surf scoters, despite I. recurvum's higher ash content and harder shell than M. lateralis. Therefore, wintering surf scoters were able to obtain the same amount of energy from each prey item, implying that they can sustain themselves if forced to switch prey.

  3. Butyltins, trace metals and morphological variables in surf scoter (Melanitta perspicillata) wintering on the south coast of British Columbia, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, J.E. [Environment Canada, Science and Technology Branch, Pacific Wildlife Research Centre, 5421 Robertson Rd., RR1 Delta, British Columbia V4K 3N2 (Canada)]. E-mail: john.elliott@ec.gc.ca; Harris, M.L. [Lorax Environmental, 136 St. Catherine' s Rd, RR3 Bonshaw, Prince Edward Island C0A 1C0 (Canada); Wilson, L.K. [Environment Canada, Canadian Wildlife Service, 5421 Robertson Rd, RR1 Delta, British Columbia V4K 3N2 (Canada); Smith, B.D. [Environment Canada, Science and Technology Branch, Pacific Wildlife Research Centre, 5421 Robertson Rd., RR1 Delta, British Columbia V4K 3N2 (Canada); Batchelor, S.P. [National Water Research Institute, Environment Canada, 867 Lakeshore Rd., PO Box 5050, Burlington, Ontario L7R 4A6 (Canada); Maguire, J. [National Water Research Institute, Environment Canada, 867 Lakeshore Rd., PO Box 5050, Burlington, Ontario L7R 4A6 (Canada)

    2007-09-15

    From 1998 to 2001 we examined spatial and temporal variation in uptake of contaminants by surf scoters (Melanitta perspicillata) in the Georgia Basin region of the Pacific coast of Canada. Samples were collected during late fall and early spring at industrialized and reference locations, carcasses examined, and tissues collected for histology, biomarkers, and contaminant analyses. Scoters from both Vancouver and Victoria harbours had significantly higher hepatic concentrations of {sigma}butyltins than birds from a reference site. In adult male surf scoters, hepatic {sigma}butyltins increased over the winter at two sites (p = 0.02, n = 26), while mercury increased (p = 0.03, n = 15) and selenium decreased at one site (p = 0.001, n = 15). Body condition decreased over the winter at both the treatment site, Howe Sound (p < 0.0001, n = 12), and the reference site, Baynes Sound (p = 0.02, n = 15). Multiple regression analysis using Akaike's Information Criteria (AIC{sub C}) showed an association between hepatic butyltin concentrations and overall body condition (p = 0.06, r = - 0.237). - Hepatic butyltin concentrations in surf scoters increased significantly over a winter in the Strait of Georgia, and correlated negatively with body condition.

  4. Interacting effects of latitude, mass, age, and sex on winter survival of Surf Scoters (Melanitta perspicillata): Implications for differential migration

    Science.gov (United States)

    Uher-Koch, Brian D.; Esler, Daniel N.; Iverson, Samuel A.; Ward, David; Boyd, Sean; Kirk, Molly; Lewis, Tyler L.; VanStratt, Corey S.; Brodhead, Katherine M.; Hupp, Jerry; Schmutz, Joel A.

    2016-01-01

    We quantified variation in winter survival of Surf Scoters (Melanitta perspicillata (L., 1758)) across nearly 30° of latitude on the Pacific coast of North America to evaluate potential effects on winter distributions, including observed differential distributions of age and sex classes. We monitored fates of 297 radio-marked Surf Scoters at three study sites: (1) near the northern periphery of their wintering range in southeast Alaska, USA, (2) the range core in British Columbia, Canada, and (3) the southern periphery in Baja California, Mexico. We detected 34 mortalities and determined that survival averaged lower at the range peripheries than in the range core, was lower during mid-winter than during late winter at all sites, and was positively correlated with body mass within locations. Although neither age nor sex class had direct effects, mass effects led to differential survival patterns among classes. When simultaneously incorporating these interacting influences, adult males of mean mass for their location had highest survival at the northern range periphery in Alaska, whereas adult females and juveniles had higher survival at the range core and the southern periphery. Our observations help to explain patterns of differential migration and distribution reported for this species and highlight seasonal periods (mid-winter) and locations (range peripheries) of elevated levels of mortality for demographically important age–sex classes (adult females).

  5. Movements of wintering surf scoters: Predator responses to different prey landscapes

    Science.gov (United States)

    Kirk, M.; Esler, Daniel; Iverson, S.A.; Boyd, W.S.

    2008-01-01

    The distribution of predators is widely recognized to be intimately linked to the distribution of their prey. Foraging theory suggests that predators will modify their behaviors, including movements, to optimize net energy intake when faced with variation in prey attributes or abundance. While many studies have documented changes in movement patterns of animals in response to temporal changes in food, very few have contrasted movements of a single predator species naturally occurring in dramatically different prey landscapes. We documented variation in the winter movements, foraging range size, site fidelity, and distribution patterns of a molluscivorous sea duck, the surf scoter (Melanitta perspicillata), in two areas of coastal British Columbia with very different shellfish prey features. Baynes Sound has extensive tidal flats with abundant clams, which are high-quality and temporally stable prey for scoters. Malaspina Inlet is a rocky fjord-like inlet where scoters consume mussels that are superabundant and easily accessible in some patches but are heavily depleted over the course of winter. We used radio telemetry to track surf scoter movements in both areas and found that in the clam habitats of Baynes Sound, surf scoters exhibited limited movement, small winter ranges, strong foraging site fidelity, and very consistent distribution patterns. By contrast, in mussel habitats in the Malaspina Inlet, surf scoters displayed more movement, larger ranges, little fidelity to specific foraging sites, and more variable distribution patterns. We conclude that features associated with the different prey types, particularly the higher depletion rates of mussels, strongly influenced seasonal space use patterns. These findings are consistent with foraging theory and confirm that predator behavior, specifically movements, is environmentally mediated. ?? 2008 Springer-Verlag.

  6. Blood lead levels of wild Steller's eiders (Polysticta stelleri) and black scoters (Melanitta nigra) in Alaska using a portable blood lead analyzer

    Science.gov (United States)

    Brown, Corrine S.; Luebbert, Joanne; Mulcahy, Daniel M.; Schamber, Jason L.; Rosenberg, Daniel H.

    2006-01-01

    Sea duck populations are declining in Alaska. The reasons for the decline are not known; environmental lead exposure is one suspected cause. Thirty wild Steller's eider ducks (Polysticta stelleri) and 40 wild black scoter ducks (Melanitta nigra) were tested for blood lead levels using a portable blood lead analyzer (LeadCare; ESA, Inc., Chelmsford, Massachusetts 01824, USA). Sixty-seven and one-tenth percent of the sea ducks had undetectable blood lead levels, 30.0% had values indicating normal or background lead exposure, and 2.9% had values indicating lead exposure. None of the birds had values indicating lead toxicity, and no birds demonstrated clinical signs of toxicity. Birds in areas with higher human population density had higher blood lead levels than those in less densely populated areas. This is the first time a portable blood lead analyzer has been utilized with sea ducks in a field setting. Because it provides immediate results, it is valuable as a screening tool for investigators carrying out surgical procedures on birds in the field as well as establishing baseline blood lead data on sea ducks. Lead exposure does occur in wild sea ducks, and the study indicates that additional research is needed in order to determine the role environmental lead plays in declining sea duck populations.

  7. Surf Scoter - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  8. Trends and population dynamics of a Velvet Scoter (Melanitta fusca) population: influence of density dependence and winter climate

    NARCIS (Netherlands)

    Hartman, G.; Kölzsch, A.; Larsson, K.; Nordberg, M.; Höglund, J.

    2013-01-01

    As many seaduck populations around the world have been reported to be in decline, there is an increasing demand for knowledge about intrinsic and extrinsic factors determining population dynamics of these species. In this study, we analyzed long-term dynamics of the summer population of Velvet Scote

  9. Environmental Assessment for Airborne Laser Debris Management Vandenberg Air Force Base, California

    Science.gov (United States)

    2008-07-01

    determined to depend on the nutritive value (i.e., nitrogen content) of phytoplankton on which they feed. Fish production, in turn, can be dependent on the...California gulls (Larus californicus), western grebes, western gulls, and surf scoters (Melanitta perspicillata) were most abundant during January...western grebes, western gulls, surf scoters, and brown pelicans were most abundant during May; and sooty shearwaters, western gulls, western grebes

  10. Environmental Assessment for Airborne Laser Debris Management Vandenberg AFB, California

    Science.gov (United States)

    2008-07-01

    zooplankton in the Southern California Bight has been determined to depend on the nutritive value (i.e., nitrogen content) of phytoplankton on which they...May and September surveys. On coastal transects, California gulls (Larus californicus), western grebes, western gulls, and surf scoters (Melanitta...perspicillata) were most abundant during January; western grebes, western gulls, surf scoters, and brown pelicans were most abundant during May

  11. Surf Tourism, Artificial Surfing Reefs, and Environmental Sustainability

    Science.gov (United States)

    Slotkin, Michael H.; Chambliss, Karen; Vamosi, Alexander R.; Lindo, Chris

    2009-07-01

    This paper explores the confluence of surf tourism, artificial surfing reefs, and sustainability. Surfing is an ascendant recreational and tourism industry and artificial surfing reefs are a new and innovative technology and product. Presented within the context of Florida's Space Coast, empirical details on surf tourism are discussed along with the possible implications for sustainability.

  12. Waterbird - Expanded Scoter and Scaup Survey: Boreal Alaska and Old Crow Flats, Canada products

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Products resulting from the Yukon Flats NWR project "Waterbird - Expanded Scoter and Scaup Survey: Boreal Alaska and Old Crow Flats, Canada" (PRIMR survey...

  13. Award Letter: Expanded Scoter and Scaup Survey: Boreal Alaska and Old Crow Flats, Canada

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Award letter in response to Alaska Region Inventory and Monitoring 2017 request for proposals. Issued to Yukon Flats NWR for project “Expanded Scoter and Scaup...

  14. Surfing on the Spectrum

    Science.gov (United States)

    Apel, Laura

    2007-01-01

    Israel Paskowitz loves surfing. As a former competitive surfer, he has spent much of his life in the ocean and absorbed in a community of athletes that share a special connection with the water. Surfing is often thought of as a spiritual hobby that brings peace and relaxation to those who experience it. However, it was not until Israel's son,…

  15. Surfing on the Spectrum

    Science.gov (United States)

    Apel, Laura

    2007-01-01

    Israel Paskowitz loves surfing. As a former competitive surfer, he has spent much of his life in the ocean and absorbed in a community of athletes that share a special connection with the water. Surfing is often thought of as a spiritual hobby that brings peace and relaxation to those who experience it. However, it was not until Israel's son,…

  16. Q&A: Surfing scientist

    Science.gov (United States)

    Hoffman, Jascha

    2013-11-01

    Historian Peter Westwick and his colleague Peter Neushul thought up their scientific history of surfing, The World in the Curl (Crown, 2013), on boards off the coast of California. As the winter surfing season gets into full swing, Westwick talks about warfare, wetsuits, climate change and forecasting surf.

  17. SURF Model Calibration Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-10

    SURF and SURFplus are high explosive reactive burn models for shock initiation and propagation of detonation waves. They are engineering models motivated by the ignition & growth concept of high spots and for SURFplus a second slow reaction for the energy release from carbon clustering. A key feature of the SURF model is that there is a partial decoupling between model parameters and detonation properties. This enables reduced sets of independent parameters to be calibrated sequentially for the initiation and propagation regimes. Here we focus on a methodology for tting the initiation parameters to Pop plot data based on 1-D simulations to compute a numerical Pop plot. In addition, the strategy for tting the remaining parameters for the propagation regime and failure diameter is discussed.

  18. Surfing the quantum world

    CERN Document Server

    Levin, Frank S

    2017-01-01

    The ideas and phenomena of the quantum world are strikingly unlike those encountered in our visual world. Surfing the Quantum World shows why and how this is so. It does this via a historical review and a gentle introduction to the fundamental principles of quantum theory, whose core concepts and symbolic representations are used to explain not only "ordinary" microscopic phenomena like the properties of the hydrogen atom and the structure of the Periodic Table of the Elements, but also a variety of mind-bending phenomena. Readers will learn that particles such as electrons and photons can behave like waves, allowing them to be in two places simultaneously, why white dwarf and neutron stars are gigantic quantum objects, how the maximum height of mountains has a quantum basis, and why quantum objects can tunnel through seemingly impenetrable barriers. Included among the various interpretational issues addressed is whether Schrodinger's cat is ever both dead and alive.

  19. Resolving Implementation Ambiguity and Improving SURF

    CERN Document Server

    Abeles, Peter

    2012-01-01

    Speeded Up Robust Features (SURF) has emerged as one of the more popular feature descriptors and detectors in recent years. Due to SURF's complexity and ambiguities found in its description, performance and algorithmic details between these implementations vary widely. To resolve these ambiguities a set of general techniques for feature stability is defined based on the smoothness rule and applied to SURF. Additional new improvements to SURF are proposed for speed and stability. To illustrate the importance of these implementation details, a performance study of popular SURF implementations is done. By utilizing all the suggested improvements it is possible to create a SURF implementation which is several times faster and/or more stable.

  20. Sand, sea and surf: segmenting South African surfers | Kruger ...

    African Journals Online (AJOL)

    Sand, sea and surf: segmenting South African surfers. ... and that they differ according to their socio-demographic characteristics, surfing behaviour and motives. The results of ... Keywords: Market segmentation; Surfing; South Africa; Typology ...

  1. Performance Analysis of Surfing: A Review.

    Science.gov (United States)

    Farley, Oliver R L; Abbiss, Chris R; Sheppard, Jeremy M

    2017-01-01

    Farley, ORL, Abbiss, CR, and Sheppard, JM. Performance Analysis of Surfing: A Review. J Strength Cond Res 31(1): 260-271, 2017-Despite the increased professionalism and substantial growth of surfing worldwide, there is limited information available to practitioners and coaches in terms of key performance analytics that are common in other field-based sports. Indeed, research analyzing surfing performance is limited to a few studies examining male surfers' heart rates, surfing activities through time-motion analysis (TMA) using video recordings and Global Positioning Satellite (GPS) data during competition and recreational surfing. These studies have indicated that specific activities undertaken during surfing are unique with a variety of activities (i.e., paddling, resting, wave riding, breath holding, and recovery of surfboard in the surf). Furthermore, environmental and wave conditions also seem to influence the physical demands of competition surfing. It is due to these demands that surfers are required to have a high cardiorespiratory fitness, high muscular endurance, and considerable strength and anaerobic power, particular within the upper torso. By exploring various methods of performance analysis used within other sports, it is possible to improve our understanding of surfing demands. In so doing this will assist in the development of protocols and strategies to assess physiological characteristics of surfers, monitor athlete performance, improve training prescription, and identify talent. Therefore, this review explores the current literature to provide insights into methodological protocols, delimitations of research into athlete analysis and an overview of surfing dynamics. Specifically, this review will describe and review the use of TMA, GPS, and other technologies (i.e., HR) that are used in external and internal load monitoring as they pertain to surfing.

  2. Mathieu Moonshine and Symmetry Surfing

    CERN Document Server

    Gaberdiel, Matthias R; Paul, Hynek

    2016-01-01

    Mathieu Moonshine, the observation that the Fourier coefficients of the elliptic genus on K3 can be interpreted as dimensions of representations of the Mathieu group M24, has been proven abstractly, but a conceptual understanding in terms of a representation of the Mathieu group on the BPS states, is missing. Some time ago, Taormina and Wendland showed that such an action can be naturally defined on the lowest non-trivial BPS states, using the idea of `symmetry surfing', i.e., by combining the symmetries of different K3 sigma models. In this paper we find non-trivial evidence that this construction can be generalized to all BPS states.

  3. Shock Detector for SURF model

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-01-11

    SURF and its extension SURFplus are reactive burn models aimed at shock initiation and propagation of detonation waves in high explosives. A distinctive feature of these models is that the burn rate depends on the lead shock pressure. A key part of the models is an algorithm to detect the lead shock. Typically, shock capturing hydro algorithms have small oscillations behind a shock. Here we investigate how well the shock detection algorithm works for a nearly steady propagating detonation wave in one-dimension using the Eulerian xRage code.

  4. Shock Detector for SURF model

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-01-11

    SURF and its extension SURFplus are reactive burn models aimed at shock initiation and propagation of detonation waves in high explosives. A distinctive feature of these models is that the burn rate depends on the lead shock pressure. A key part of the models is an algorithm to detect the lead shock. Typically, shock capturing hydro algorithms have small oscillations behind a shock. Here we investigate how well the shock detection algorithm works for a nearly steady propagating detonation wave in one-dimension using the Eulerian xRage code.

  5. Towards designing miniature surfing robots

    Science.gov (United States)

    Jafari Kang, Saeed; Vandadi, Vahid; Masoud, Hassan

    2016-11-01

    We theoretically study the surfing motion of chemically and thermally active particles located at a flat liquid-gas interface that sits above a liquid layer of finite depth. The particles' activity creates and maintains a surface tension gradient resulting in the auto-surfing. It is intuitively perceived that Marangoni surfers propel towards the direction with a higher surface tension. Remarkably, we find that the surfers may propel in the lower surface tension direction depending on their geometry and proximity to the bottom of the liquid layer. In particular, our analytical calculations for Stokes flow and diffusion-dominated scalar (i.e. chemical concentration and temperature) fields indicate that spherical particles undergo reverse Marangoni propulsion under confinement whereas disk-shaped surfers always move in the expected direction. We extend our results by proposing an approximate formula for the propulsion speed of oblate spheroidal particles based on the speeds of spheres and disks. Overall, our findings pave the way for designing microsurfers capable of operating in bounded environments.

  6. Contaminants and sea ducks in Alaska and the circumpolar region

    Science.gov (United States)

    Henny, C.J.; Rudis, D.D.; Roffe, T.J.; Robinson-Wilson, E.

    1995-01-01

    We review nesting sea duck population declines in Alaska during recent decades and explore the possibility that contaminants may be implicated. Aerial surveys of the surf scoter (Melanitta perspicillata) , white-winged scoter (M. fusca) , black scoter (M. nigra) , oldsquaw (Clangula hyemalis) , spectacled eider (Somateria fischeri) , and Steller's eider (Polysticta stelleri) show long-term breeding population declines, especially the latter three species. The spectacled eider was recently classified threatened under the Endangered Species Act. In addition, three other diving ducks, which commonly winter in coastal areas, have declined from unknown causes. Large die-offs of all three species of scoters during molt, a period of high energy demand, were documented in August 1990, 1991, and 1992 at coastal reefs in southeastern Alaska. There was no evidence of infectious diseases in those scoters. The die-offs may or may not be associated with the long-term declines. Many scoters had elevated renal concentrations of cadmium (high of 375 ?g/g dry weight [dw]). Effects of cadmium in sea ducks are not well understood. Selenium concentrations in livers of nesting white-winged scoters were high ; however, the eggs they laid contained less selenium than expected based on relationships for freshwater bird species. Histological evaluation found a high prevalence of hepatocellular vacuolation (49%) , a degenerative change frequently associated with sublethal toxic insult. Cadmium and selenium mean liver concentrations were generally higher in those birds with more severe vacuolation ; however, relationships were not statistically significant. We do not know if sea duck population declines are related to metals or other contaminants.

  7. Characterization of SURF-1 expression and Surf-1p function in normal and disease conditions.

    Science.gov (United States)

    Tiranti, V; Galimberti, C; Nijtmans, L; Bovolenta, S; Perini, M P; Zeviani, M

    1999-12-01

    Loss-of-function mutations of the SURF-1 gene have been associated with Leigh syndrome with cytochrome c oxidase (COX) deficiency. Mature Surf-1 protein (Surf-1p) is a 30 kDa hydrophobic polypeptide whose function is still unknown. Using antibodies against a recombinant, hemagglutinin-tagged Surf-1p, we have demonstrated that this protein is imported into mitochondria as a larger precursor, which is then processed into the mature product by cleaving off an N-terminal leader polypeptide of approximately 40 amino acids. By using western blot analysis with specific antibodies, we showed that Surf-1p is localized in and tightly bound to the mitochondrial inner membrane. The same analysis revealed that no protein is present in cell lines harboring loss-of-function mutations of SURF-1, regardless of their type and position. Northern blot analysis showed the virtual absence of specific SURF-1 transcripts in different mutant cell lines. This result suggests that several mutations of SURF-1 are associated with severe mRNA instability. To understand better whether and which domains of the protein are essential for function, we generated several constructs with truncated or partially deleted SURF-1 cDNAs. None of these constructs, expressed into Surf-1p null mutant cells, were able to rescue the COX phenotype, suggesting that different regions of the protein are all essential for function. Finally, experiments based on blue native two-dimensional gel electrophoresis indicated that assembly of COX in Surf-1p null mutants is blocked at an early step, most likely before the incorporation of subunit II in the nascent intermediates composed of subunit I alone or subunit I plus subunit IV. However, detection of residual amounts of fully assembled complex suggests a certain degree of redundancy of this system.

  8. Experimental Investigation of Shock Wave Surfing

    CERN Document Server

    Parziale, N J; Hornung, H G; Shepherd, J E

    2010-01-01

    Shock wave surfing is investigated experimentally in GALCIT's Mach 4.0 Ludwieg Tube. Shock wave surfing occurs when a secondary free-body follows the bow shock formed by a primary free-body; an example of shock wave surfing occurs during meteorite breakup. The free-bodies in the current investigation are nylon spheres. During each run in the Ludwieg tube a high speed camera is used to capture a series of schlieren images; edge tracking software is used to measure the position of each sphere. Velocity and acceleration are had from processing the position data. The radius ratio and initial orientation of the two spheres are varied in the test matrix. The variation of sphere radius ratio and initial angle between the centers of gravity are shown to have a significant effect on the dynamics of the system.

  9. Quantitative assessment of surf-produced sea spray aerosol

    NARCIS (Netherlands)

    Neele, F.P.; De Leeuw, G.; Jansen, M.; Stive, M.J.F.

    1998-01-01

    The first results are presented from a quantitative model describing the aerosol production in the surf zone. A comparison is made with aerosol produced in the surf zone as measured during EOPACE experiments in La Jolla and Monterey. The surf aerosol production was derived from aerosol concentration

  10. Quantitative assessment of surf-produced sea spray aerosol

    NARCIS (Netherlands)

    Neele, F.P.; De Leeuw, G.; Jansen, M.; Stive, M.J.F.

    1998-01-01

    The first results are presented from a quantitative model describing the aerosol production in the surf zone. A comparison is made with aerosol produced in the surf zone as measured during EOPACE experiments in La Jolla and Monterey. The surf aerosol production was derived from aerosol concentration

  11. Women's Recreational Surfing: A Patronising Experience

    Science.gov (United States)

    Olive, Rebecca; McCuaig, Louise; Phillips, Murray G.

    2015-01-01

    Research analysing the operation of power within sport and physical activity has exposed the marginalisation and exclusion of women's sport in explicit and institutionalised ways. However, for women in recreational and alternative physical activities like surfing, sporting experiences lie outside institutionalised structures, thus requiring…

  12. An Analysis of the SURF Method

    Directory of Open Access Journals (Sweden)

    Edouard Oyallon

    2015-07-01

    Full Text Available The SURF method (Speeded Up Robust Features is a fast and robust algorithm for local, similarity invariant representation and comparison of images. Similarly to many other local descriptor-based approaches, interest points of a given image are defined as salient features from a scale-invariant representation. Such a multiple-scale analysis is provided by the convolution of the initial image with discrete kernels at several scales (box filters. The second step consists in building orientation invariant descriptors, by using local gradient statistics (intensity and orientation. The main interest of the SURF approach lies in its fast computation of operators using box filters, thus enabling real-time applications such as tracking and object recognition. The SURF framework described in this paper is based on the PhD thesis of H. Bay [ETH Zurich, 2009], and more specifically on the paper co-written by H. Bay, A. Ess, T. Tuytelaars and L. Van Gool [Computer Vision and Image Understanding, 110 (2008, pp. 346–359]. An implementation is proposed and used to illustrate the approach for image matching. A short comparison with a state-of-the-art approach is also presented, the SIFT algorithm of D. Lowe [International Journal of Computer Vision, 60 (2004, pp. 91–110], with which SURF shares a lot in common.

  13. Enhanced Approximated SURF Model For Object Recognition

    Directory of Open Access Journals (Sweden)

    S. Sangeetha

    2014-02-01

    Full Text Available Computer vision applications like camera calibration, 3D reconstruction, and object recognition and image registration are becoming widely popular now a day. In this paper an enhanced model for speeded up robust features (SURF is proposed by which the object recognition process will become three times faster than common SURF model The main idea is to use efficient data structures for both, the detector and the descriptor. The detection of interest regions is considerably speed-up by using an integral image for scale space computation. The descriptor which is based on orientation histograms is accelerated by the use of an integral orientation histogram. We present an analysis of the computational costs comparing both parts of our approach to the conventional method. Extensive experiments show a speed-up by a factor of eight while the matching and repeatability performance is decreased only slightly.

  14. Multispectral observations of the surf zone

    Science.gov (United States)

    Schoonmaker, Jon S.; Dirbas, Joseph; Gilbert, Gary

    2003-09-01

    Airborne multispectral imagery was collected over various targets on the beach and in the water in an attempt to characterize the surf zone environment with respect to electro-optical system capabilities and to assess the utility of very low cost, small multispectral systems in mine counter measures (MCM) and intelligence, surveillance and reconnaissance applications. The data was collected by PAR Government Systems Corporation (PGSC) at the Army Corps of Engineers Field Research Facility at Duck North Carolina and on the beaches of Camp Pendleton Marine Corps Base in Southern California. PGSC flew the first two of its MANTIS (Mission Adaptable Narrowband Tunable Imaging Sensor) systems. Both MANTIS systems were flown in an IR - red - green - blue (700, 600, 550, 480 nm) configuration from altitudes ranging from 200 to 700 meters. Data collected has been lightly analyzed and a surf zone index (SZI) defined and calculated. This index allows mine hunting system performance measurements in the surf zone to be normalized by environmental conditions. The SZI takes into account water clarity, wave energy, and foam persistence.

  15. Modeling and Simulation for a Surf Zone Robot

    Science.gov (United States)

    2012-12-14

    on a surf zone vehicle focused on negative buoyancy using tracked platforms that used traditional tank drive mechanisms to remain on the sea floor...through the surf zone transit and drive on to the beach. Provided by the Surf Zone Crawler Group of Naval Surface Warfare Center Panama City, a Foster...with the traction and obstacle scaling of a leg [2]. Further work elaborated this concept into an entire drivetrain concept. Focused on the

  16. Lidar and aerosol measurements over the surf zone

    NARCIS (Netherlands)

    Moerman, M.M.; Cohen, L.H.; Leeuw, G. de; Kunz, G.J.

    2001-01-01

    The aerosol produced by waves breaking in the surf zone is important for a variety of processes, such as transport of pollutants and bacteria, and electro optical propagation in the coastal zone. Yet, quantitative information on surf produced aerosol is very limited (de Leeuw et al., 2000). In the f

  17. User's Manual for Space Debris Surfaces (SD_SURF)

    Science.gov (United States)

    Elfer, N. C.

    1996-01-01

    A unique collection of computer codes, Space Debris Surfaces (SD_SURF), have been developed to assist in the design and analysis of space debris protection systems. SD_SURF calculates and summarizes a vehicle's vulnerability to space debris as a function of impact velocity and obliquity. An SD_SURF analysis will show which velocities and obliquities are the most probable to cause a penetration. This determination can help the analyst select a shield design which is best suited to the predominant penetration mechanism. The analysis also indicates the most suitable parameters for development or verification testing. The SD_SURF programs offer the option of either FORTRAN programs and Microsoft EXCEL spreadsheets and macros. The FORTRAN programs work with BUMPERII version 1.2a or 1.3 (Cosmic released). The EXCEL spreadsheets and macros can be used independently or with selected output from the SD_SURF FORTRAN programs.

  18. The effect of varying protein levels on blood chemistry, food consumption, and behavior of captive seaducks

    Science.gov (United States)

    Wells-Berlin, A. M.; Perry, M.C.; Olsen, G.H.

    2005-01-01

    The Chesapeake Bay is a primary wintering area for scoters and the long-tailed ducks (Clangia hyemalis) that migrate along the Atlantic Flyway. Recently, the Chesapeake Bay had undergone an ecosystem shift and little is known about how this is affecting the seaduck populations. We are determining what are the preferred food sources of the seaducks wintering on the Bay and analyzing the factors influencing prey selection whether it is prey composition, energy assimilated, prey availability, or a combination of any or all of these factors. We have established a captive colony of surf (Melanitta perspicillata) and white-winged scoters (Melanitta fusca) as well as long-tailed ducks at Patuxent Wildlife Research Center to allow us to examine these factors in a more controlled environment. This project contains a multitude of experiments and the resultant data will be compiled into a compartmental model on the feeding ecology of seaducks wintering on the Bay. The first experiment entailed feeding groups of each species (four ducks per pen of equal sex ratio, if possible, and four pens per species) three diets varying in percent protein levels from November to February. Each diet was randomly assigned to each pen and the amount of food consumed was recorded each day. New feed was given when all existing food was consumed. Behavioral trials and blood profiles were completed on all study birds to determine the effects of the varying diets. There were no significant differences in food consumption, blood chemistry, and behavior detected at the 5% level among the diets for all three species of interest. There was a seasonal effect determined based on the food consumption data for white-winged scoters, but not for surf scoters or long-tailed ducks. The blood profiles of the surf scoters were compared to blood profiles of wild surf scoters and a there was no difference detected at the 5% level. As a health check of the ducks an aspergillosis test was run on the blood obtained

  19. Confined Disposal Facility at Pointe Mouillee for Detroit and Rouge Rivers.

    Science.gov (United States)

    1974-03-01

    21. Common Merganser (Mergus merganser) 22. Ruddy Duck (Oxyura jamaicensis) 23. Common Scoter (Oidemia nigra ) 24. White-winged Scoter (Melanitta...Herring Gull (Larus argentatus) 5. Common Tern (Sterna hirundo hirundo) 6. Caspian Tern (Hydroprogne caspia) 7. Black Tern (Chlidonias nigra ...Hibiscus) Trees Silver Maple (Acer saccharinum) none Box Elder (Acer negundo) Apple (Malus) Peach (Prunus persica) Mulberry ( Morus ) Bronze Beech

  20. 76 FR 8651 - Special Local Regulation; Mavericks Surf Competition, Half Moon Bay, CA

    Science.gov (United States)

    2011-02-15

    ... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulation; Mavericks Surf Competition... the Mavericks Surf Competition. This special local regulation is necessary to ensure the safety of... dangers posed by the surf conditions during the Mavericks Surf Competition, the special local regulation...

  1. Let’s Surf on The internet

    Institute of Scientific and Technical Information of China (English)

    李申禹

    1996-01-01

    在今日大学之校园内,电脑热正呈“奔腾”之势。李申禹所在的寝室购买了一台“合资”电脑,这为他们的学习另辟了一块天地,也为他们的生活着上了一点色彩,Let′s Surf on The Internet这篇习作标题潇洒,内容实在,既写出了作者漫步电脑书林的惊喜,又有对未来的展望——现在的年青人将携着the electronic books跨入新世纪。习作开首较好地运用了parllelism:结尾想象驰骋,并巧妙点题。本文Reviewed by Mr.John C.Green

  2. Palmprint Based Verification System Using SURF Features

    Science.gov (United States)

    Srinivas, Badrinath G.; Gupta, Phalguni

    This paper describes the design and development of a prototype of robust biometric system for verification. The system uses features extracted using Speeded Up Robust Features (SURF) operator of human hand. The hand image for features is acquired using a low cost scanner. The palmprint region extracted is robust to hand translation and rotation on the scanner. The system is tested on IITK database of 200 images and PolyU database of 7751 images. The system is found to be robust with respect to translation and rotation. It has FAR 0.02%, FRR 0.01% and accuracy of 99.98% and can be a suitable system for civilian applications and high-security environments.

  3. Mercury in birds of San Francisco Bay-Delta, California: trophic pathways, bioaccumulation, and ecotoxicological risk to avian reproduction

    Science.gov (United States)

    Ackerman, Joshua T.; Eagles-Smith, Collin A.; Heinz, Gary; De La Cruz, Susan E. W.; Takekawa, John Y.; Miles, A. Keith; Adelsbach, Terrence L.; Herzog, Mark P.; Bluso-Demers, Jill D.; Demers, Scott A.; Herring, Garth; Hoffman, David J.; Hartman, Christopher A.; Willacker, James J.; Suchanek, Thomas H.; Schwarzbach, Steven E.; Maurer, Thomas C.

    2014-01-01

    San Francisco Bay Estuary in northern California has a legacy of mercury contamination, which could reduce the health and reproductive success of waterbirds in the estuary. The goal of this study was to use an integrated field and laboratory approach to evaluate the risks of mercury exposure to birds in the estuary. We examined mercury bioaccumulation, and other contaminants of concern, in five waterbird species that depend heavily on San Francisco Bay Estuary for foraging and breeding habitat: American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), Forster’s terns (Sterna forsteri), Caspian terns (Hydroprogne caspia), and surf scoters (Melanitta perspicillata). These species have different foraging habitats and diets that represent three distinct foraging guilds within the estuary’s food web. In this report, we provide an integrated synthesis of the primary findings from this study and results are synthesized from 54 peer-reviewed publications generated to date with other unpublished results.

  4. Surfing the internet with a BCI mouse

    Science.gov (United States)

    Yu, Tianyou; Li, Yuanqing; Long, Jinyi; Gu, Zhenghui

    2012-06-01

    In this paper, we present a new web browser based on a two-dimensional (2D) brain-computer interface (BCI) mouse, where our major concern is the selection of an intended target in a multi-target web page. A real-world web page may contain tens or even hundreds of targets, including hyperlinks, input elements, buttons, etc. In this case, a target filter designed in our system can be used to exclude most of those targets of no interest. Specifically, the user filters the targets of no interest out by inputting keywords with a P300-based speller, while keeps those containing the keywords. Such filtering largely facilitates the target selection task based on our BCI mouse. When there are only several targets in a web page (either an original sparse page or a target-filtered page), the user moves the mouse toward the target of interest using his/her electroencephalographic signal. The horizontal movement and vertical movement are controlled by motor imagery and P300 potential, respectively. If the mouse encounters a target of no interest, the user rejects it and continues to move the mouse. Otherwise the user selects the target and activates it. With the collaboration of the target filtering and a series of mouse movements and target selections/rejections, the user can select an intended target in a web page. Based on our browser system, common navigation functions, including history rolling forward and backward, hyperlink selection, page scrolling, text input, etc, are available. The system has been tested on seven subjects. Experimental results not only validated the efficacy of the proposed method, but also showed that free internet surfing with a BCI mouse is feasible.

  5. Sorry,officer,I was just surfing

    Institute of Scientific and Technical Information of China (English)

    英文姿

    1998-01-01

    美国被称为a nation on wheels(汽车轮子上的国家),当今计算机科学的迅猛发展与汽车车型的改进和设计的“联姻”就是一个必然。 本文对这种“联姻”的产品——network vehicle/net-mobile——的描绘具有极大的诱惑力: In a net-mobile, a motorist could tap into a regional road system not only to getdirections but also to map out a route around rush-hour traffic snags. Drivers andpassengers will be able to send and receive email, track the latest sports scores or stockquotes, surf the Web, and even play video games. 当然,除了上述“表层”的“联姻”之外.尚有其“深层”的“联姻”,如: On-board microcomputers improve fuel economy and reduce emissions. 也许有人会问:开车时一心岂能两用?不必担心: It not only offered such desktop-computer-like services as email, but allowed adriver to use them without looking away form the road. 文章还列举了不少名车,如General Motors,Toyota,BMW和Mecedes-Benz 已经研制了net-mobile的样车。其中的神奇之处有: OnStar also calls automatically for help if an accident triggers the airbag. (OnStar系统能在事故触发了保

  6. Goddard and Caldwell Oahu, Hawaii Surf Observation Dataset for 1968-2004 (NODC Accession 0001754)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surf reports are typically made several times per day at select locations around Oahu, primarily by Honolulu City and County lifeguards and the Surf News Network,...

  7. Goddard and Caldwell: Oahu, Hawaii surf observation data set for 1968 - 2004 (NODC Accession 0001754)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surf reports are typically made several times per day at select locations around Oahu, primarily by Honolulu City and County lifeguards and the Surf News Network,...

  8. Evaluation of Sift and Surf for Vision Based Localization

    Science.gov (United States)

    Qu, Xiaozhi; Soheilian, Bahman; Habets, Emmanuel; Paparoditis, Nicolas

    2016-06-01

    Vision based localization is widely investigated for the autonomous navigation and robotics. One of the basic steps of vision based localization is the extraction of interest points in images that are captured by the embedded camera. In this paper, SIFT and SURF extractors were chosen to evaluate their performance in localization. Four street view image sequences captured by a mobile mapping system, were used for the evaluation and both SIFT and SURF were tested on different image scales. Besides, the impact of the interest point distribution was also studied. We evaluated the performances from for aspects: repeatability, precision, accuracy and runtime. The local bundle adjustment method was applied to refine the pose parameters and the 3D coordinates of tie points. According to the results of our experiments, SIFT was more reliable than SURF. Apart from this, both the accuracy and the efficiency of localization can be improved if the distribution of feature points are well constrained for SIFT.

  9. Sea spray aerosol and wave energy dissipation in the surf zone

    NARCIS (Netherlands)

    Francius, M.J.; Piazzola, J.; Forget, P.; Calve, O. le; Kusmierczyk-Michulec, J.

    2007-01-01

    Results from a quantitative model for the prediction of the sea-salt mass flux produced in the surf zone are presented in this paper. The model relates the surf zone sea salt mass flux to the amount of wave energy dissipated in the surf zone. In order to apply this aerosol emission model, a wave num

  10. Searching versus surfing: how different ways of acquiring content online affect cognitive processing.

    Science.gov (United States)

    Wise, Kevin; Kim, Hyo Jung

    2008-06-01

    An experiment tested whether people orient to and encode pictures selected from a Web site differently, depending on whether the pictures were selected by searching or surfing. Participants in the search condition spent more time selecting pictures than the participants in the surf condition spent. The pictures chosen in the search condition elicited cardiac orienting, while pictures chosen in the surf condition did not. Participants recognized pictures acquired by searching more accurately than they recognized those acquired by surfing, indicating that searching led to better encoding than surfing.

  11. Collaboration on ICT in Dutch Higher Education: The SURF Approach

    Science.gov (United States)

    Boezerooy, Petra; Cordewener, Bas; Liebrand, Wim

    2007-01-01

    In "Thinking Ahead: A Vision of the Role of ICT in Education and Research in the Future, 2007-2010," the higher education institutions in the Netherlands agreed on future strategy. Under the direction of SURF, the Dutch national organization, a collaborative strategy for the application of information and communications technology (ICT)…

  12. Global concept, local practice: Taiwanese experience of CouchSurfing

    NARCIS (Netherlands)

    Chen, D.-J.

    2012-01-01

    Hospitality exchange tourism is a new type of niche tourism, which is highly dependent on the Internet. Through participating in global hospitality exchange networks, such as CouchSurfing, tourists can meet local people who are willing to offer free accommodation, and hosts can also meet people arou

  13. CoBrowser: Surfing the Web Using a Standard Browser.

    Science.gov (United States)

    Maly, K.; Zubair, M.; Li, L.

    Co-browsing is a synchronous class of collaborative applications, which allows a group of users to surf the Web together. Such an application can be deployed in an education environment in several ways. One example of where it can be used would be in courses that are project-oriented. Students would be required to collectively research or explore…

  14. Droplets move over viscoelastic substrates by surfing a ridge

    NARCIS (Netherlands)

    Karpitschka, S.A.; Das, S.; Gorcum, van M.; Perrin, H.; Andreotti, B.; Snoeijer, J.H.

    2015-01-01

    Liquid drops on soft solids generate strong deformations below the contact line, resulting from a balance of capillary and elastic forces. The movement of these drops may cause strong, potentially singular dissipation in the soft solid. Here we show that a drop on a soft substrate moves by surfing a

  15. Sea-spray aerosol particles generated in the surf zone

    NARCIS (Netherlands)

    Eijk, A.M.J. van; Kusmierczyk‐Michulec, J.T.; Francius, M.J.; Tedeschi, G.; Piazzola,J.; Merritt, D.L.; Fontana, J.D.

    2011-01-01

    To assess the properties of aerosol particles generated over the surf zone, two experiments were held at the pier of Scripps Institution of Oceanography (SIO), La Jolla CA, and at the pier of the U.S. Army Corps of Engineers Field Research Facility (FRF) in Duck NC. On both sites concentrations of s

  16. Observations of turbulence within a natural surf zone

    NARCIS (Netherlands)

    Ruessink, B.G.

    2010-01-01

    Here, the Reynolds stresses and , where u′, v′, and w′ are the cross-shore, alongshore, and vertical turbulence velocities, respectively, and the angle brackets represent time averaging, are used to diagnose turbulence dynamics beneath natural breaking surf-zone waves. The data were col

  17. Internet Surfing for Kindergarten Children: A Feasibility Study

    Science.gov (United States)

    Loo, Alfred

    2012-01-01

    The Internet is an effective learning tool for gifted children because it allows them to independently select the areas in which they have talent. The Internet also enables children to discover and maximize their potential. However, younger children might not have a large enough vocabulary to surf the Internet, even if they are gifted. For…

  18. Data on cytochrome c oxidase assembly in mice and human fibroblasts or tissues induced by SURF1 defect.

    Science.gov (United States)

    Kovářová, Nikola; Pecina, Petr; Nůsková, Hana; Vrbacký, Marek; Zeviani, Massimo; Mráček, Tomáš; Viscomi, Carlo; Houštěk, Josef

    2016-06-01

    This paper describes data related to a research article entitled "Tissue- and species-specific differences in cytochrome c oxidase assembly induced by SURF1 defects" [1]. This paper includes data of the quantitative analysis of individual forms of respiratory chain complexes I, III and IV present in SURF1 knockout (SURF1 (-/-) ) and control (SURF1 (+/+) ) mouse fibroblasts and tissues and in fibroblasts of human control and patients with SURF1 gene mutation. Also it includes data demonstrating response of complex IV, cytochrome c oxidase (COX), to reversible inhibition of mitochondrial translation in SURF1 (-/-) mouse and SURF1 patient fibroblast cell lines.

  19. Occurrence of larval fishes in the surf zone of a northern Gulf of Mexico barrier island

    Science.gov (United States)

    Ruple, David L.

    1984-02-01

    Larval fishes were collected from the surf zone of Horn Island, Mississippi between March 1978 and April 1979. A standardized total of 39 435 larvae were taken from 222 collections in the inner and outer surf zone regions, representing fish in 69 taxa. Overall, considerably more larvae were collected in the outer surf zone (78·3%) than in the inner surf zone (21·7%). Engraulids, Chloroscombrus chrysurus and Symphurus spp. were the most abundant larvae taken from the outer surf zone while engraulids, Leiostomus xanthurus, Brevoortia patronus and Trinectes maculatus were the numerically dominant larvae in the inner surf zone. Seasonal peaks in abundance occurred at the outer surf zone stations during May and June and at the inner surf zone stations during December. Larval densities were significantly greater in night collections than in day collections. The occurrence of early larvae, late larvae and juveniles suggests that the surf zone habitat is important to several species of coastal marine fishes. Menticirrhus littoralis, Harengula jaguana and Trachinotus carolinus appear to most readily utilize the surf zone as a nursery area.

  20. Surf zone Exchange on a Rip Channeled Beach

    Science.gov (United States)

    Reniers, A.; Macmahan, J.

    2008-12-01

    The dispersion and surf zone exchange of GPS-equipped surface drifters observed during the Rip Current EXperiment (RCEX) is examined with help of Lagrangian Coherent Structures (LCSs). LCSs allow for the detection of transport barriers in unsteady flows and are typically applied to shelf-scale circulation systems. Here LCSs are specifically computed to detect the effects of surfzone-originated Very Low Frequency motions (VLFs) with O(10) minute time scale on the cross-shore exchange of floating material using numerical model calculations of the Lagrangian surface velocity at the wave group timescale. After verification with RCEX field observations, the model is run for a range of environmental conditions experienced during the field experiment to assess the effects of VLFs on the cross-shore surf zone exchange. Results are relevant for (but not restricted to) sediment and nutrient exchange, human health, water clarity, and swimmer safety.

  1. Region Duplication Forgery Detection Technique Based on SURF and HAC

    Directory of Open Access Journals (Sweden)

    Parul Mishra

    2013-01-01

    Full Text Available Region duplication forgery detection is a special type of forgery detection approach and widely used research topic under digital image forensics. In copy move forgery, a specific area is copied and then pasted into any other region of the image. Due to the availability of sophisticated image processing tools, it becomes very hard to detect forgery with naked eyes. From the forged region of an image no visual clues are often detected. For making the tampering more robust, various transformations like scaling, rotation, illumination changes, JPEG compression, noise addition, gamma correction, and blurring are applied. So there is a need for a method which performs efficiently in the presence of all such attacks. This paper presents a detection method based on speeded up robust features (SURF and hierarchical agglomerative clustering (HAC. SURF detects the keypoints and their corresponding features. From these sets of keypoints, grouping is performed on the matched keypoints by HAC that shows copied and pasted regions.

  2. SURF IA Conflict Detection and Resolution Algorithm Evaluation

    Science.gov (United States)

    Jones, Denise R.; Chartrand, Ryan C.; Wilson, Sara R.; Commo, Sean A.; Barker, Glover D.

    2012-01-01

    The Enhanced Traffic Situational Awareness on the Airport Surface with Indications and Alerts (SURF IA) algorithm was evaluated in a fast-time batch simulation study at the National Aeronautics and Space Administration (NASA) Langley Research Center. SURF IA is designed to increase flight crew situation awareness of the runway environment and facilitate an appropriate and timely response to potential conflict situations. The purpose of the study was to evaluate the performance of the SURF IA algorithm under various runway scenarios, multiple levels of conflict detection and resolution (CD&R) system equipage, and various levels of horizontal position accuracy. This paper gives an overview of the SURF IA concept, simulation study, and results. Runway incursions are a serious aviation safety hazard. As such, the FAA is committed to reducing the severity, number, and rate of runway incursions by implementing a combination of guidance, education, outreach, training, technology, infrastructure, and risk identification and mitigation initiatives [1]. Progress has been made in reducing the number of serious incursions - from a high of 67 in Fiscal Year (FY) 2000 to 6 in FY2010. However, the rate of all incursions has risen steadily over recent years - from a rate of 12.3 incursions per million operations in FY2005 to a rate of 18.9 incursions per million operations in FY2010 [1, 2]. The National Transportation Safety Board (NTSB) also considers runway incursions to be a serious aviation safety hazard, listing runway incursion prevention as one of their most wanted transportation safety improvements [3]. The NTSB recommends that immediate warning of probable collisions/incursions be given directly to flight crews in the cockpit [4].

  3. Stern-Gerlach surfing in laser wakefield accelerators

    CERN Document Server

    Flood, Stephen P

    2015-01-01

    We investigate the effects of a Stern-Gerlach-type addition to the Lorentz force on electrons in a laser wakefield accelerator. The Stern-Gerlach-type terms are found to generate a family of trajectories describing electrons that surf along the plasma density wave driven by a laser pulse. Such trajectories could lead to an increase in the size of an electron bunch, which may have implications for attempts to exploit such bunches in future free electron lasers.

  4. Stern-Gerlach surfing in laser wakefield accelerators

    Science.gov (United States)

    Flood, Stephen P.; Burton, David A.

    2015-09-01

    We investigate the effects of a Stern-Gerlach-type addition to the Lorentz force on electrons in a laser wakefield accelerator. The Stern-Gerlach-type terms are found to generate a family of trajectories describing electrons that 'surf' along the plasma density wave driven by a laser pulse. Such trajectories could lead to an increase in the size of an electron bunch, which may have implications for attempts to exploit such bunches in future free electron lasers.

  5. Las alteraciones posturales en miembros inferiores en el surf

    OpenAIRE

    2015-01-01

    Cuando el equilibrio neuromuscular no es óptimo durante la práctica de un deporte, es posible que, a largo plazo, aparezcan trastornos posturales que, dependiendo del tiempo de entrenamiento, pueden convertirse en un obstáculo para la salud. Es por esto, que mediante esta investigación he pretendido mostrar las alteraciones posturales que el surf puede llegar a provocar en quienes lo practican. Objetivo: Analizar las alteraciones posturales en los miembros inferiores de surfist...

  6. The Vertical Structure of Shallow Water Flow in the Surf Zone and Inner Shelf

    Science.gov (United States)

    2008-01-01

    E. Richardson, 2008, Field verification of a CFD model for wave transformation and breaking in the surf zone, J. Waterw. Port Coastal Engrg., 134(2...The Vertical Structure of Shallow Water Flow in the Surf Zone and Inner Shelf Dr. Thomas C. Lippmann Center for Coastal...wave- and tidally-driven shallow water flows in the shallow depths of the inner shelf and surf zone. OBJECTIVES 1. Theoretical investigations of

  7. Distribution patterns of wintering sea ducks in relation to the North Atlantic Oscillation and local environmental characteristics

    Science.gov (United States)

    Zipkin, Elise F.; Gardner, Beth; Gilbert, Andrew T.; O'Connell, Allan F.; Royle, J. Andrew; Silverman, Emily D.

    2010-01-01

    Twelve species of North American sea ducks (Tribe Mergini) winter off the eastern coast of the United States and Canada. Yet, despite their seasonal proximity to urbanized areas in this region, there is limited information on patterns of wintering sea duck habitat use. It is difficult to gather information on sea ducks because of the relative inaccessibility of their offshore locations, their high degree of mobility, and their aggregated distributions. To characterize environmental conditions that affect wintering distributions, as well as their geographic ranges, we analyzed count data on five species of sea ducks (black scoters Melanitta nigra americana, surf scoters M. perspicillata, white-winged scoters M. fusca, common eiders Somateria mollissima, and long-tailed ducks Clangula hyemalis) that were collected during the Atlantic Flyway Sea Duck Survey for ten years starting in the early 1990s. We modeled count data for each species within ten-nautical-mile linear survey segments using a zero-inflated negative binomial model that included four local-scale habitat covariates (sea surface temperature, mean bottom depth, maximum bottom slope, and a variable to indicate if the segment was in a bay or not), one broad-scale covariate (the North Atlantic Oscillation), and a temporal correlation component. Our results indicate that species distributions have strong latitudinal gradients and consistency in local habitat use. The North Atlantic Oscillation was the only environmental covariate that had a significant (but variable) effect on the expected count for all five species, suggesting that broad-scale climatic conditions may be directly or indirectly important to the distributions of wintering sea ducks. Our results provide critical information on species-habitat associations, elucidate the complicated relationship between the North Atlantic Oscillation, sea surface temperature, and local sea duck abundances, and should be useful in assessing the impacts of climate

  8. Evaluation of harvest and information needs for North American sea ducks

    Science.gov (United States)

    Koneff, Mark D.; Zimmerman, Guthrie S.; Dwyer, Chris P.; Fleming, Kathleen K.; Padding, Paul I.; Devers, Patrick K.; Johnson, Fred A.; Runge, Michael C.; Roberts, Anthony J.

    2017-01-01

    Wildlife managers routinely seek to establish sustainable limits of sport harvest or other regulated forms of take while confronted with considerable uncertainty. A growing body of ecological research focuses on methods to describe and account for uncertainty in management decision-making and to prioritize research and monitoring investments to reduce the most influential uncertainties. We used simulation methods incorporating measures of demographic uncertainty to evaluate risk of overharvest and prioritize information needs for North American sea ducks (Tribe Mergini). Sea ducks are popular game birds in North America, yet they are poorly monitored and their population dynamics are poorly understood relative to other North American waterfowl. There have been few attempts to assess the sustainability of harvest of North American sea ducks, and no formal harvest strategy exists in the U.S. or Canada to guide management. The popularity of sea duck hunting, extended hunting opportunity for some populations (i.e., special seasons and/or bag limits), and population declines have led to concern about potential overharvest. We used Monte Carlo simulation to contrast estimates of allowable harvest and observed harvest and assess risk of overharvest for 7 populations of North American sea ducks: the American subspecies of common eider (Somateria mollissima dresseri), eastern and western populations of black scoter (Melanitta americana) and surf scoter (M. perspicillata), and continental populations of white-winged scoter (M. fusca) and long-tailed duck (Clangula hyemalis). We combined information from empirical studies and the opinions of experts through formal elicitation to create probability distributions reflecting uncertainty in the individual demographic parameters used in this assessment. Estimates of maximum growth (rmax), and therefore of allowable harvest, were highly uncertain for all populations. Long-tailed duck and American common eider appeared to be at high

  9. Tissue- and species-specific differences in cytochrome c oxidase assembly induced by SURF1 defects.

    Science.gov (United States)

    Kovářová, Nikola; Pecina, Petr; Nůsková, Hana; Vrbacký, Marek; Zeviani, Massimo; Mráček, Tomáš; Viscomi, Carlo; Houštěk, Josef

    2016-04-01

    Mitochondrial protein SURF1 is a specific assembly factor of cytochrome c oxidase (COX), but its function is poorly understood. SURF1 gene mutations cause a severe COX deficiency manifesting as the Leigh syndrome in humans, whereas in mice SURF1(-/-) knockout leads only to a mild COX defect. We used SURF1(-/-) mouse model for detailed analysis of disturbed COX assembly and COX ability to incorporate into respiratory supercomplexes (SCs) in different tissues and fibroblasts. Furthermore, we compared fibroblasts from SURF1(-/-) mouse and SURF1 patients to reveal interspecies differences in kinetics of COX biogenesis using 2D electrophoresis, immunodetection, arrest of mitochondrial proteosynthesis and pulse-chase metabolic labeling. The crucial differences observed are an accumulation of abundant COX1 assembly intermediates, low content of COX monomer and preferential recruitment of COX into I-III2-IVn SCs in SURF1 patient fibroblasts, whereas SURF1(-/-) mouse fibroblasts were characterized by low content of COX1 assembly intermediates and milder decrease in COX monomer, which appeared more stable. This pattern was even less pronounced in SURF1(-/-) mouse liver and brain. Both the control and SURF1(-/-) mice revealed only negligible formation of the I-III2-IVn SCs and marked tissue differences in the contents of COX dimer and III2-IV SCs, also less noticeable in liver and brain than in heart and muscle. Our studies support the view that COX assembly is much more dependent on SURF1 in humans than in mice. We also demonstrate markedly lower ability of mouse COX to form I-III2-IVn supercomplexes, pointing to tissue-specific and species-specific differences in COX biogenesis.

  10. Impact of the Internet surfing on reading practices and choices

    Directory of Open Access Journals (Sweden)

    Fayaz Ahmad Loan

    2012-06-01

    Full Text Available Reading in the 21st century networked society is no longer confined to the print reading. The scope of the reading has extended to the Internet sources that changed the traditional reading culture of the readers. The present study was conducted to identify the impact of the Internet surfing on reading practices and choices of the net generation college students. The survey method was applied to conduct the study and a questionnaire was used as a data collection tool. A sample of 676 students was selected from different strata based on gender, region and faculty in the degree colleges of the Kashmir region, Jammu and Kashmir state, India. In the sample size only 302 confirmed themselves as the e-readers and their responses were analyzed. Results reveal that the reading behavior of the online readers is in transition as the Internet surfing has increased non-sequential reading, interactive reading, superficial reading, and extensive reading and at the same rates is responsible for decreasing concentrated and in-depth reading. Plus, the Internet surfing has increased reading of the news & views, general knowledge, selected fields, sexual content, spiritual/religious text and has decreased reading of literature. To validate the results, the findings were correlated with earlier studies and hypotheses were formed and tested using the Chi-square test. However, the students have not experienced any electronic reading device like kindle (of Amazon or iPod (of Apple during browsing the electronic sources and it could be the future area of research.

  11. Ribosomal protein L7a is encoded by a gene (Surf-3) within the tightly clustered mouse surfeit locus.

    Science.gov (United States)

    Giallongo, A; Yon, J; Fried, M

    1989-01-01

    The mouse Surfeit locus, which contains a cluster of at least four genes (Surf-1 to Surf-4), is unusual in that adjacent genes are separated by no more than 73 base pairs (bp). The heterogeneous 5' ends of Surf-1 and Surf-2 are separated by only 15 to 73 bp, the 3' ends of Surf-1 and Surf-3 are only 70 bp apart, and the 3' ends of Surf-2 and Surf-4 overlap by 133 bp. This very tight clustering suggests a cis interaction between adjacent Surfeit genes. The Surf-3 gene (which could code for a basic polypeptide of 266 amino acids) is a highly expressed member of a pseudogene-containing multigene family. By use of an anti-peptide serum (against the C-terminal nine amino acids of the putative Surf-3 protein) for immunofluorescence and immunoblotting of mouse cell components and by in vitro translation of Surf-3 cDNA hybrid-selected mRNA, the Surf-3 gene product was identified as a 32-kilodalton ribosomal protein located in the 60S ribosomal subunit. From its subunit location, gel migration, and homology with a limited rat ribosomal peptide sequence, the Surf-3 gene was shown to encode the mouse L7a ribosomal protein. The Surf-3 gene is highly conserved through evolution and was detected by nucleic acid hybridization as existing in multiple copies (multigene families) in other mammals and as one or a few copies in birds, Xenopus, Drosophila, and Schizosaccharomyces pombe. The Surf-3 C-terminal anti-peptide serum detects a 32-kilodalton protein in other mammals, birds, and Xenopus but not in Drosophila and S. pombe. The possible effect of interaction of the Surf-3 ribosomal protein gene with adjacent genes in the Surfeit locus at the transcriptional or posttranscriptional level or both levels is discussed. Images PMID:2648130

  12. Image Retrieval Method Using Top-surf Descriptor

    CERN Document Server

    Ji, Ye

    2011-01-01

    This report presents the results and details of a content-based image retrieval project using the Top-surf descriptor. The experimental results are preliminary, however, it shows the capability of deducing objects from parts of the objects or from the objects that are similar. This paper uses a dataset consisting of 1200 images of which 800 images are equally divided into 8 categories, namely airplane, beach, motorbike, forest, elephants, horses, bus and building, while the other 400 images are randomly picked from the Internet. The best results achieved are from building category.

  13. Electron surfing acceleration in a current sheet of flares

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A model of electron acceleration in a current sheet of flares is studied by the analytical approximation solution and the test particle simulation. The electron can be trapped in a potential of propagating electrostatic wave. The trapped electron moving with the phase velocity vp of wave may be effectively accelerated by evc p× Bz force along the outflow direction in the current sheet, if a criterion condition K > 0 for electron surfing acceleration is satisfied. The electron will be accelerated continuously until the electron detrap from the wave potential at the turning point S.

  14. Cross-shore currents in the surf zone

    DEFF Research Database (Denmark)

    Aagaard, Troels; Vinther, Niels

    2008-01-01

      While the dynamics and kinematics of various types of mean cross-shore current flows in the surf zone (undertow and rip currents) are fairly well understood, the causes for transitions occurring between these two types of mean circulation patterns remain obscure. On longshore barred beaches......, such transitions involve the formation and/or degeneration of rip channels. In this paper, field evidence is presented to suggest that transitions between undertow and rip current (cell) circulations may depend upon the magnitude of the wave-induced onshore mass transport across a longshore bar, rip channel...... that both hydrodynamic conditions and existing bathymetry are critical in determining the type of mean current circulation....

  15. Bedforms and undertow in the surf zone; an analysis of the LIP 11D-data

    NARCIS (Netherlands)

    Boers, M.

    1995-01-01

    The present report gives the results of a study on bedforms and undertow in the surf zone. It is the objective of this study to get a better insight into the physical processes in the surf zone. In this study, we make use of the data obtained during the LIP llDexperiments (Arcilla et al. [1994] and

  16. Transport of larvae and detritus across the surf zone of a steep reflective pocket beach

    NARCIS (Netherlands)

    Shanks, A.L.; MacMahan, J.; Morgan, S.G.; Reniers, A.J.H.M.; Jarvis, M.; Brown, J.; Fujimura, A.; Griesemer, C.

    2015-01-01

    Larvae of many intertidal species develop offshore and must cross the surf zone to complete their onshore migration to adult habitats. Depending on hydrodynamics, the surf zone may limit this migration, especially on reflective rocky shores. As a logistically tractable analog of a rocky shore enviro

  17. Social Networking Sites' Influence on Travelers' Authentic Experience a Case Study of Couch Surfing

    Science.gov (United States)

    Liu, Xiao

    2013-01-01

    This study explored travelers' experiences in the era of network hospitality 2.0 using CouchSurfing.org as a case study. The following research questions guided this study: 1) what experience does CouchSurfing create for travelers before, during and after their travel? 2) how does couch surfers' experience relate to authenticity in context of…

  18. E-based Humanities and E-humanities on a SURF platform

    NARCIS (Netherlands)

    Kircz, J.G.

    2004-01-01

    As of 2003, SURF enables three platforms: ICT and Research, Education, and Organisation. Within these programmes, SURF has funds available to promote ICT innovations. Innovation is not an easy notion to explain. Too often we encounter new wine in old bottles and changes in vocabulary frequently cove

  19. Transport of larvae and detritus across the surf zone of a steep reflective pocket beach

    NARCIS (Netherlands)

    Shanks, A.L.; MacMahan, J.; Morgan, S.G.; Reniers, A.J.H.M.; Jarvis, M.; Brown, J.; Fujimura, A.; Griesemer, C.

    2015-01-01

    Larvae of many intertidal species develop offshore and must cross the surf zone to complete their onshore migration to adult habitats. Depending on hydrodynamics, the surf zone may limit this migration, especially on reflective rocky shores. As a logistically tractable analog of a rocky shore

  20. Learning and Identity in Overlapping Communities of Practice: Surf Club, School and Sports Clubs

    Science.gov (United States)

    Light, Richard; Nash, Melanie

    2006-01-01

    Large numbers of children and young people spend their weekends and holidays engaged in the activities of over 300 surf clubs across Australia each summer. Long term membership in these clubs, beginning from as young as five years of age, forms a significant part of children's and young people's development yet surf clubs have yet to receive…

  1. Sea spray aerosol production from waves breaking in the surf zone

    NARCIS (Netherlands)

    Leeuw, G. de

    1999-01-01

    Sea spray aerosol is a product of wave breaking. A very strong source of this aerosol is the surf zone. In this sense, measurements in the surf zone can be suitable for the assessment of the contributions of the various spray production mechanisms to the total concentrations. At present, a comprehen

  2. Information surfing with the JHU/APL coherent imager

    Science.gov (United States)

    Ratto, Christopher R.; Shipley, Kara R.; Beagley, Nathaniel; Wolfe, Kevin C.

    2015-05-01

    The ability to perform remote forensics in situ is an important application of autonomous undersea vehicles (AUVs). Forensics objectives may include remediation of mines and/or unexploded ordnance, as well as monitoring of seafloor infrastructure. At JHU/APL, digital holography is being explored for the potential application to underwater imaging and integration with an AUV. In previous work, a feature-based approach was developed for processing the holographic imagery and performing object recognition. In this work, the results of the image processing method were incorporated into a Bayesian framework for autonomous path planning referred to as information surfing. The framework was derived assuming that the location of the object of interest is known a priori, but the type of object and its pose are unknown. The path-planning algorithm adaptively modifies the trajectory of the sensing platform based on historical performance of object and pose classification. The algorithm is called information surfing because the direction of motion is governed by the local information gradient. Simulation experiments were carried out using holographic imagery collected from submerged objects. The autonomous sensing algorithm was compared to a deterministic sensing CONOPS, and demonstrated improved accuracy and faster convergence in several cases.

  3. Repensar la comunicación institucional: las diez reglas del surf / Rethinking institutional communication: the ten rules of surfing

    Directory of Open Access Journals (Sweden)

    Diego Apolo Buenaño

    2014-12-01

    Full Text Available En este ensayo se presenta un análisis desde distintas concepciones de la comunicación estratégica, en donde además de vincular aspectos centrales y tensiones que enfrentan las organizaciones en la actualidad, se ofrecen acercamientos teóricos y prácticos que contribuyan a repensar la manera que en se desarrolla la comunicación en las instituciones. En el trabajo se vincula el deporte del surf y sus reglas como eje que permite realizar comparaciones que aporten al abordaje de la comunicación desde perspectivas que buscan la confluencia entre intereses institucionales y de los actores que intervienen en el proceso mediante la investigación del entorno, el respeto a las prácticas sociales y la colaboración como base para la consecución de los objetivos conjuntos. Abstract This article presents an analysis from different conceptions of strategic communication, which in addition to linking central aspects and tensions developed by organizations today, theoretical and practical approaches are offered and contribute to rethink the way that the communication is developed in institutions. In this work the sport of surfing and its rules are vinculated as the axis that allows comparisons to contribute to addressing communication from perspectives seeking convergence between institutional interests and actors involved in the process investigating the environment, the respect to social practices and collaboration as the basis for achieving the common goals.

  4. Influence of the Surf Zone on the Marine Aerosol Concentration in a Coastal Area

    Science.gov (United States)

    Tedeschi, Gilles; van Eijk, Alexander M. J.; Piazzola, Jacques; Kusmierczyk-Michulec, Jolanta T.

    2017-01-01

    Sea-salt aerosol concentrations in the coastal zone are assessed with the numerical aerosol-transport model MACMod that applies separate aerosol source functions for open ocean and the surf zone near the sea-land transition. Numerical simulations of the aerosol concentration as a function of offshore distance from the surf zone compare favourably with experimental data obtained during a surf-zone aerosol experiment in Duck, North Carolina in autumn 2007. Based on numerical simulations, the effect of variations in aerosol production (source strength) and transport conditions (wind speed, air-sea temperature difference), we show that the surf-zone aerosols are replaced by aerosols generated over the open ocean as the airmass advects out to sea. The contribution from the surf-generated aerosol is significant during high wind speeds and high wave events, and is significant up to 30 km away from the production zone. At low wind speeds, the oceanic component dominates, except within 1-5 km of the surf zone. Similar results are obtained for onshore flow, where no further sea-salt aerosol production occurs as the airmass advects out over land. The oceanic aerosols that are well-mixed throughout the boundary layer are then more efficiently transported inland than are the surf-generated aerosols, which are confined to the first few tens of metres above the surface, and are therefore also more susceptible to the type of surface (trees or grass) that determines the deposition velocity.

  5. Surf zone diatoms: A review of the drivers, patterns and role in sandy beaches food chains

    Science.gov (United States)

    Odebrecht, Clarisse; Du Preez, Derek R.; Abreu, Paulo Cesar; Campbell, Eileen E.

    2014-10-01

    The accumulation of high biomass of diatoms in the surf zone is a characteristic feature of some sandy beaches where the wave energy is sufficiently high. A few species of diatoms, called surf diatoms, thrive in this harsh environment. The main processes driving the spatial and temporal distribution of surf diatoms as well as their standing biomass and growth were described twenty to thirty years ago based on studies conducted on the western coast of the United States of America and South African beaches. Since then, over fifty locations around the world have been reported to have surf diatom accumulations with most (three-quarters) of these being in the southern hemisphere. Their occurrence is controlled by physical and chemical factors, including wave energy, beach slope and length, water circulation patterns in the surf zone and the availability of nutrients to sustain the high biomass. The main forces driving the patterns of temporal variability of surf diatom accumulations are meteorological. In the short term (hours), the action of wind stress and wave energy controls the diatom accumulation. In the intermediate time scale (weeks to months), seasonal onshore winds of sufficient strength, as well as storm events are important. Furthermore, anthropogenic disturbances that influence the beach ecosystem as well as large-scale events, such as the El Niño Southern Oscillation, may lead to significant changes in surf diatom populations in the long term (inter-annual). Surf diatoms form the base of a short and very productive food chain in the inshore of the sandy beaches where they occur. However, the role of surf diatoms in the microbial food web is not clear and deserves further studies.

  6. Numerical modeling of surf beat generated by moving breakpoint

    Institute of Scientific and Technical Information of China (English)

    DONG GuoHai; MA XiaoZhou; TENG Bin

    2009-01-01

    As an important hydrodynamic phenomenon in the nearshore zone, the cross-shore surf beat is nu-merically studied in this paper with a fully nonlinear Boussinesq-type model, which resolves the pri-mary wave motion as well as the long waves. Compared with the classical Boussinesq equations, the equations adopted here allow for improved linear dispersion characteristics. Wave breaking and run-up in the swash zone are included in the numerical model. Mutual interactions between short waves and long waves are inherent in the model. The numerical study of long waves is based on bichromatic wave groups with a wide range of mean frequencies, group frequencies and modulation rates. The cross-shore variation in the amplitudes of short waves and long waves is investigated. The model results are compared with laboratory experiments from the literature and good agreement is found.

  7. Modelling of sediment movement in the surf and swash zones

    Institute of Scientific and Technical Information of China (English)

    TOKPOHOZIN N B; KOUNOUHEWA B; AVOSSEVOU G Y H; HOUEKPOHEHAM A; AWANOU C N

    2015-01-01

    Under the action of marine currents, non-cohesive sediments evolve by bed-load, by saltation or suspension depending on their granulometry. Several authors have considered that the movement of sediment is bidimensional and modelized the effects of swell by a constant velocitynear the seabed. Here we have studied the velocity profile of fluctuating currents near the seabed and studied the movement of sediment in 3D. The results show that in the areas of study (surf and swash) the movement of sediment occurs in a volume, and the evolution of sediment varies from an areato another. The obtained theoretical profiles of the position and velocity vectors confirm the observations of several authors.

  8. Detection of Region Duplication Forgery in Digital Images Using SURF

    Directory of Open Access Journals (Sweden)

    B L Shivakumar

    2011-07-01

    Full Text Available An Image would yield better impact in convincing someone of something rather than pure description by words. Digital images are widely used in various fields like medical imaging, journalism, scientific manipulations and digital forensics. However, images are not reliable as it may be. Digital images can be easily tampered with image editing tools. One of the major problems in image forensics is determining if a particular image is authentic or not. Digital image forensic is an emerging field of image processing area. Copy-move forgery is one type of image forgery in digital image forensic where various methods have been proposed in the field to detect the forgery. In this paper a technique is presented to detect Copy-Move Forgery based on SURF and KD-Tree for multidimensional data matching. We demonstrate our method with high resolution images affected by copy-move forgery.

  9. SurfCut: Free-Boundary Surface Extraction

    KAUST Repository

    Algarni, Marei

    2016-09-15

    We present SurfCut, an algorithm for extracting a smooth simple surface with unknown boundary from a noisy 3D image and a seed point. In contrast to existing approaches that extract smooth simple surfaces with boundary, our method requires less user input, i.e., a seed point, rather than a 3D boundary curve. Our method is built on the novel observation that certain ridge curves of a front propagated using the Fast Marching algorithm are likely to lie on the surface. Using the framework of cubical complexes, we design a novel algorithm to robustly extract such ridge curves and form the surface of interest. Our algorithm automatically cuts these ridge curves to form the surface boundary, and then extracts the surface. Experiments show the robustness of our method to errors in the data, and that we achieve higher accuracy with lower computational cost than comparable methods. © Springer International Publishing AG 2016.

  10. Numerical modeling of surf beat generated by moving breakpoint

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    As an important hydrodynamic phenomenon in the nearshore zone, the cross-shore surf beat is numerically studied in this paper with a fully nonlinear Boussinesq-type model, which resolves the primary wave motion as well as the long waves. Compared with the classical Boussinesq equations, the equations adopted here allow for improved linear dispersion characteristics. Wave breaking and run-up in the swash zone are included in the numerical model. Mutual interactions between short waves and long waves are inherent in the model. The numerical study of long waves is based on bichromatic wave groups with a wide range of mean frequencies, group frequencies and modulation rates. The cross-shore variation in the amplitudes of short waves and long waves is investigated. The model results are compared with laboratory experiments from the literature and good agreement is found.

  11. Military personnel recognition system using texture, colour, and SURF features

    Science.gov (United States)

    Irhebhude, Martins E.; Edirisinghe, Eran A.

    2014-06-01

    This paper presents an automatic, machine vision based, military personnel identification and classification system. Classification is done using a Support Vector Machine (SVM) on sets of Army, Air Force and Navy camouflage uniform personnel datasets. In the proposed system, the arm of service of personnel is recognised by the camouflage of a persons uniform, type of cap and the type of badge/logo. The detailed analysis done include; camouflage cap and plain cap differentiation using gray level co-occurrence matrix (GLCM) texture feature; classification on Army, Air Force and Navy camouflaged uniforms using GLCM texture and colour histogram bin features; plain cap badge classification into Army, Air Force and Navy using Speed Up Robust Feature (SURF). The proposed method recognised camouflage personnel arm of service on sets of data retrieved from google images and selected military websites. Correlation-based Feature Selection (CFS) was used to improve recognition and reduce dimensionality, thereby speeding the classification process. With this method success rates recorded during the analysis include 93.8% for camouflage appearance category, 100%, 90% and 100% rates of plain cap and camouflage cap categories for Army, Air Force and Navy categories, respectively. Accurate recognition was recorded using SURF for the plain cap badge category. Substantial analysis has been carried out and results prove that the proposed method can correctly classify military personnel into various arms of service. We show that the proposed method can be integrated into a face recognition system, which will recognise personnel in addition to determining the arm of service which the personnel belong. Such a system can be used to enhance the security of a military base or facility.

  12. Surfing through Hyperspace - Understanding Higher Universes in Six Easy Lessons

    Science.gov (United States)

    Pickover, Clifford A.

    2001-05-01

    Do a little armchair time-travel, rub elbows with a four-dimensional intelligent life form, or stretch your mind to the furthest corner of an uncharted universe. With this astonishing guidebook, Surfing Through Hyperspace , you need not be a mathematician or an astrophysicist to explore the all-but-unfathomable concepts of hyperspace and higher-dimensional geometry.No subject in mathematics has intrigued both children and adults as much as the idea of a fourth dimension. Philosophers and parapsychologists have meditated on this mysterious space that no one can point to but may be all around us. Yet this extra dimension has a very real, practical value to mathematicians and physicists who use it every day in their calculations. In the tradition of Flatland , and with an infectious enthusiasm, Clifford Pickover tackles the problems inherent in our 3-D brains trying to visualize a 4-D world, muses on the religious implications of the existence of higher-dimensional consciousness, and urges all curious readers to venture into "the unexplored territory lying beyond the prison of the obvious." Pickover alternates sections that explain the science of hyperspace with sections that dramatize mind-expanding concepts through a fictional dialogue between two futuristic FBI agents who dabble in the fourth dimension as a matter of national security. This highly accessible and entertaining approach turns an intimidating subject into a scientific game open to all dreamers.Surfing Through Hyperspace concludes with a number of puzzles, computer experiments and formulas for further exploration, inviting readers to extend their minds across this inexhaustibly intriguing scientific terrain.

  13. Evaluation of a 3% surf solution (surf field mastitis test) for the diagnosis of subclinical bovine and bubaline mastitis.

    Science.gov (United States)

    Muhammad, Ghulam; Naureen, Abeera; Asi, Muhammad Nadeem; Saqib, Muhammad; Fazal-ur-Rehman

    2010-03-01

    To evaluate a 3% solution of household detergent viz., Surf Excel (Surf field mastitis test, SFMT) vis-à-vis California mastitis test (CMT), Whiteside test (WST), somatic cell counts (SCC; cut off limit = 5 x 10(5) cells per millilitre) and bacteriological cultures for the detection of subclinical mastitis in quarter foremilk samples (n=800) of dairy cows and buffaloes. Culture and SCC were used as gold standards. All tests were evaluated parallel and serial patterns. The sensitivities of SFMT, SCC, culture, CMT and WST in parallel testing were 72.82, 81.55, 87.38, 75.73 and 54.37%, respectively in cows, while 66.22, 79.73, 82.43, 70.27 and 50.00, respectively in buffaloes. SFMT was significantly (pCMT in both species. In serial testing, percent specificity of SFMT (87.12 in cow; 85.16 in buffaloes) was significantly (PCMT (83.33 in cow; 80.64 in buffaloes). The negative predictive values of SFMT (93.50 in cow; 96.35 in buffaloes) differed non-significantly from that of CMT (94.02 in cow; 96.15 in buffaloes). The kappa index between the tests was moderate to perfect both in parallel (0.54 to >0.80) and serial (0.58 to >0.8) testing. On the basis of closely similar diagnostic efficiency of SFMT to CMT in terms of sensitivity, specificity, predictive values and kappa index together with inexpensive and ready availability of SFMT reagent, it tempting to suggest that SFMT can be use as a cheaper, user-friendly alternative animal-side subclinical mastitis diagnostic test in poor countries.

  14. SURF imaging beams in an aberrative medium: generation and post-processing enhancement

    CERN Document Server

    Nasholm, Sven Peter; 10.1109/TUFFC.2012.2494

    2013-01-01

    This paper presents numerical simulations of dual-frequency second-order ultrasound field (SURF) reverberation suppression transmit-pulse complexes. Such propagation was previously studied in a homogeneous medium. Here instead the propagation path includes a strongly aberrating body-wall modeled by a sequence of delay-screens. The applied SURF transmit pulse complexes each consist of a high-frequency imaging 3.5 MHz pulse combined with a low-frequency 0.5 MHz sound speed manipulation pulse. Furthermore, the feasibility of two signal post-processing methods are investigated using the aberrated transmit SURF beams. These methods are previously shown to adjust the depth of maximum SURF reverberation suppression within a homogeneous medium. The request of the study arises because imaging situations where reverberation suppression is useful are also likely to produce pulse wave-front distortion (aberration). Such distortions could potentially produce time-delays that cancel the accumulated propagation time-delay n...

  15. Analytical Derivation of Three Dimensional Vorticity Function for wave breaking in Surf Zone

    CERN Document Server

    Dutta, R

    2015-01-01

    In this report, Mathematical model for generalized nonlinear three dimensional wave breaking equations was de- veloped analytically using fully nonlinear extended Boussinesq equations to encompass rotational dynamics in wave breaking zone. The three dimensional equations for vorticity distributions are developed from Reynold based stress equations. Vorticity transport equations are also developed for wave breaking zone. This equations are basic model tools for numerical simulation of surf zone to explain wave breaking phenomena. The model reproduces most of the dynamics in the surf zone. Non linearity for wave height predictions is also shown close to the breaking both in shoaling as well as surf zone. Keyword Wave breaking, Boussinesq equation, shallow water, surf zone. PACS : 47.32-y

  16. The rate of beneficial mutations surfing on the wave of a range expansion.

    Directory of Open Access Journals (Sweden)

    Rémi Lehe

    Full Text Available Many theoretical and experimental studies suggest that range expansions can have severe consequences for the gene pool of the expanding population. Due to strongly enhanced genetic drift at the advancing frontier, neutral and weakly deleterious mutations can reach large frequencies in the newly colonized regions, as if they were surfing the front of the range expansion. These findings raise the question of how frequently beneficial mutations successfully surf at shifting range margins, thereby promoting adaptation towards a range-expansion phenotype. Here, we use individual-based simulations to study the surfing statistics of recurrent beneficial mutations on wave-like range expansions in linear habitats. We show that the rate of surfing depends on two strongly antagonistic factors, the probability of surfing given the spatial location of a novel mutation and the rate of occurrence of mutations at that location. The surfing probability strongly increases towards the tip of the wave. Novel mutations are unlikely to surf unless they enjoy a spatial head start compared to the bulk of the population. The needed head start is shown to be proportional to the inverse fitness of the mutant type, and only weakly dependent on the carrying capacity. The precise location dependence of surfing probabilities is derived from the non-extinction probability of a branching process within a moving field of growth rates. The second factor is the mutation occurrence which strongly decreases towards the tip of the wave. Thus, most successful mutations arise at an intermediate position in the front of the wave. We present an analytic theory for the tradeoff between these factors that allows to predict how frequently substitutions by beneficial mutations occur at invasion fronts. We find that small amounts of genetic drift increase the fixation rate of beneficial mutations at the advancing front, and thus could be important for adaptation during species invasions.

  17. The rate of beneficial mutations surfing on the wave of a range expansion.

    Science.gov (United States)

    Lehe, Rémi; Hallatschek, Oskar; Peliti, Luca

    2012-01-01

    Many theoretical and experimental studies suggest that range expansions can have severe consequences for the gene pool of the expanding population. Due to strongly enhanced genetic drift at the advancing frontier, neutral and weakly deleterious mutations can reach large frequencies in the newly colonized regions, as if they were surfing the front of the range expansion. These findings raise the question of how frequently beneficial mutations successfully surf at shifting range margins, thereby promoting adaptation towards a range-expansion phenotype. Here, we use individual-based simulations to study the surfing statistics of recurrent beneficial mutations on wave-like range expansions in linear habitats. We show that the rate of surfing depends on two strongly antagonistic factors, the probability of surfing given the spatial location of a novel mutation and the rate of occurrence of mutations at that location. The surfing probability strongly increases towards the tip of the wave. Novel mutations are unlikely to surf unless they enjoy a spatial head start compared to the bulk of the population. The needed head start is shown to be proportional to the inverse fitness of the mutant type, and only weakly dependent on the carrying capacity. The precise location dependence of surfing probabilities is derived from the non-extinction probability of a branching process within a moving field of growth rates. The second factor is the mutation occurrence which strongly decreases towards the tip of the wave. Thus, most successful mutations arise at an intermediate position in the front of the wave. We present an analytic theory for the tradeoff between these factors that allows to predict how frequently substitutions by beneficial mutations occur at invasion fronts. We find that small amounts of genetic drift increase the fixation rate of beneficial mutations at the advancing front, and thus could be important for adaptation during species invasions.

  18. Sandy beach surf zones: An alternative nursery habitat for 0-age Chinook salmon

    Science.gov (United States)

    Marin Jarrin, J. R.; Miller, J. A.

    2013-12-01

    The role of each habitat fish use is of great importance to the dynamics of populations. During their early marine residence, Chinook salmon (Oncorhynchus tshawytscha), an anadromous fish species, mostly inhabit estuaries but also use sandy beach surf zones and the coastal ocean. However, the role of surf zones in the early life history of Chinook salmon is unclear. We hypothesized that surf zones serve as an alternative nursery habitat, defined as a habitat that consistently provides a proportion of a population with foraging and growth rates similar to those experienced in the primary nursery. First, we confirmed that juvenile Chinook salmon cohorts are simultaneously using both habitats by combining field collections with otolith chemical and structural analysis to directly compare size and migration patterns of juveniles collected in two Oregon (USA) estuaries and surf zones during three years. We then compared juvenile catch, diet and growth in estuaries and surf zones. Juveniles were consistently caught in both habitats throughout summer. Catches were significantly higher in estuaries (average ± SD = 34.3 ± 19.7 ind. 100 m-2) than surf zones (1.0 ± 1.5 ind. 100 m-2) and were positively correlated (r = 0.92). Size at capture (103 ± 15 mm fork length, FL), size at marine entry (76 ± 13 mm FL), stomach fullness (2 ± 2% body weight) and growth rates (0.4 ± 0.0 mm day-1) were similar between habitats. Our results suggest that when large numbers of 0-age Chinook salmon inhabit estuaries, juveniles concurrently use surf zones, which serve as an alternative nursery habitat. Therefore, surf zones expand the available rearing habitat for Chinook salmon during early marine residence, a critical period in the life history.

  19. Summary of Second Regional Workshop on Dredging, Beach Nourishment, and Bids on the North Atlantic Coast

    Science.gov (United States)

    2007-11-01

    Name Scientific Name Common Loon Gavia immer Black Scoter Melanitta nigra Red-throated Loon Gavia Stellata Common Goldeneye Bucephala clangula Horned...Oceanodroma leucorhoa Clapper Rail Rallus longirostris Northern Gannet Morus bassanus King Rail Rallus elegans Great Cormorant Phalacrocorax carbo...Skimmer Rynchops nigra Short-billed Dowitcher Limnodromus griseus Razorbill Alca torda Red-necked Phalarope Phalaropus lobatus Black Guillemot Cepphus

  20. Large Eddy Simulation for Wave Breaking in the Surf Zone

    Institute of Scientific and Technical Information of China (English)

    白玉川; 蒋昌波; 沈焕庭

    2001-01-01

    In this paper, the large eddy simulation method is used combined with the marker and cell method to study the wave propagation or shoaling and breaking process. As wave propagates into shallow water, the shoaling leads to the increase of wave height, and then at a certain position, the wave will be breaking. The breaking wave is a powerful agent for generating turbulence, which plays an important role in most of the fluid dynamic processes throughout the sarf zone, such as transformation of wave energy, generation of near-shore current and diffusion of materials. So a proper numerical model for describing the turbulence effect is needed. In this paper, a revised Smagorinsky subgrid-scale model is used to describe the turbulence effect. The present study reveals that the coefficient of the Smagorinsky model for wave propagation or breaking simulation may be taken as a varying function of the water depth and distance away from the wave breaking point. The large eddy simulation model presented in this paper has been used to study the propagation of the solitary wave in constant water depth and the shoaling of the non-breaking solitary wave on a beach. The model is based on large eddy simulation, and to track free-surface movements, the Tokyo University Modified Marker and Cell (TUMMAC) method is employed. In order to ensure the accuracy of each component of this wave mathematical model,several steps have been taken to verify calculated solutions with either analytical solutions or experimental data. For non-breaking waves, very accurate results are obtained for a solitary wave propagating over a constant depth and on a beach. Application of the model to cnoidal wave breaking in the surf zone shows that the model results are in good agreement with analytical solution and experimental data. From the present model results, it can be seen that the turbulent eddy viscosity increases from the bottom to the water surface in surf zone. In the eddy viscosity curve, there is a

  1. The Relationship Between Shoreline Change and Surf Zone Sand Thickness

    Science.gov (United States)

    Miselis, J. L.; McNinch, J. E.

    2002-12-01

    There is a lack of information concerning surf zone geologic processes and their relationship to shoreline behavior despite the consensus that the two are intimately linked. Variations in sand thickness over a highly irregular migration surface close to the shoreline may influence wave dynamics and sediment transport and thus may be connected to hotspot formation. A nearshore survey, spanning 40km from north of the USACE-FRF pier in Duck, NC to just north of Oregon Inlet, was conducted using an interferometric swath bathymetry system and a chirp sub-bottom profiler. The study was conducted within 1km of the shore (in the surf zone) to investigate the processes that may be responsible for the behavior of shoreline hotspots in the area. The topmost reflector and the seafloor of the seismic profile were digitized and the depth difference between them was calculated. Though no ground truths were done in the survey area, cores collected from just north of the site suggest that the topmost reflector is a pre-modern ravinement surface (cohesive muds with layers of sand and gravel) upon which the Holocene sands migrate. An isopach map was generated and shows that the layer of sand above the first sub-bottom reflector is very thin and in some places, exposed. There are many variables that may influence hotspot behavior, including bar position and wave conditions, however, the purpose of this study is to determine if there is a spatial correlation between a thin or absent (exposed reflector) nearshore sand layer and the presence of a shoreline hotspot. In an area associated with a hotspot approximately 14km south of the USACE-FRF pier in Duck, the maximum thickness of Holocene sands was less than 2.5m. The average thickness was less than 1m (0.705m). Thicknesses that were less than 0.2m were classified as areas where the reflector was exposed and accounted for 5 percent of those calculated. It seems the thin layer of sand may represent a deficient nearshore sand source

  2. Face Recognition System based on SURF and LDA Technique

    Directory of Open Access Journals (Sweden)

    Narpat A. Singh

    2016-02-01

    Full Text Available In the past decade, Improve the quality in face recognition system is a challenge. It is a challenging problem and widely studied in the different type of imag-es to provide the best quality of faces in real life. These problems come due to illumination and pose effect due to light in gradient features. The improvement and optimization of human face recognition and detection is an important problem in the real life that can be handles to optimize the error rate, accuracy, peak signal to noise ratio, mean square error, and structural similarity Index. Now-a-days, there several methods are proposed to recognition face in different problem to optimize above parameters. There occur many invariant changes in hu-man faces due to the illumination and pose variations. In this paper we proposed a novel method in face recogni-tion to improve the quality parameters using speed up robust feature and linear discriminant analysis for opti-mize result. SURF is used for feature matching. In this paper, we use linear discriminant analysis for the edge dimensions reduction to live faces from our data-sets. The proposed method shows the better result as compare to the previous result on the basis of comparative analysis because our method show the better quality and better results in live images of face.

  3. Large herbivores surf waves of green-up during spring.

    Science.gov (United States)

    Merkle, Jerod A; Monteith, Kevin L; Aikens, Ellen O; Hayes, Matthew M; Hersey, Kent R; Middleton, Arthur D; Oates, Brendan A; Sawyer, Hall; Scurlock, Brandon M; Kauffman, Matthew J

    2016-06-29

    The green wave hypothesis (GWH) states that migrating animals should track or 'surf' high-quality forage at the leading edge of spring green-up. To index such high-quality forage, recent work proposed the instantaneous rate of green-up (IRG), i.e. rate of change in the normalized difference vegetation index over time. Despite this important advancement, no study has tested the assumption that herbivores select habitat patches at peak IRG. We evaluated this assumption using step selection functions parametrized with movement data during the green-up period from two populations each of bighorn sheep, mule deer, elk, moose and bison, totalling 463 individuals monitored 1-3 years from 2004 to 2014. Accounting for variables that typically influence habitat selection for each species, we found seven of 10 populations selected patches exhibiting high IRG-supporting the GWH. Nonetheless, large herbivores selected for the leading edge, trailing edge and crest of the IRG wave, indicating that other mechanisms (e.g. ruminant physiology) or measurement error inherent with satellite data affect selection for IRG. Our evaluation indicates that IRG is a useful tool for linking herbivore movement with plant phenology, paving the way for significant advancements in understanding how animals track resource quality that varies both spatially and temporally.

  4. Surfing through hyperspace understanding higher universes in six easy lessons

    CERN Document Server

    Pickover, Clifford A

    1999-01-01

    Do a little armchair time-travel, rub elbows with a four-dimensional intelligent life form, or stretch your mind to the furthest corner of an uncharted universe. With this astonishing guidebook, Surfing Through Hyperspace, you need not be a mathematician or an astrophysicist to explore the all-but-unfathomable concepts of hyperspace and higher-dimensional geometry. No subject in mathematics has intrigued both children and adults as much as the idea of a fourth dimension. Philosophers and parapsychologists have meditated on this mysterious space that no one can point to but may be all around us. Yet this extra dimension has a very real, practical value to mathematicians and physicists who use it every day in their calculations. In the tradtion of Flatland, and with an infectious enthusiasm, Clifford Pickover tackles the problems inherent in our 3-D brains trying to visualize a 4-D world, muses on the religious implications of the existence of higher-dimensional consciousness, and urges all curious readers to v...

  5. On the mitigation of surf-riding by adjusting center of buoyancy in design stage

    Directory of Open Access Journals (Sweden)

    Liwei Yu

    2017-05-01

    Full Text Available High-speed vessels are prone to the surf-riding in adverse quartering seas. The possibility of mitigating the surf-riding of the ITTC A2 fishing vessel in the design stage is investigated using the 6-DOF weakly non-linear model developed for surf-riding simulations in quartering seas. The longitudinal position of the ship's center of buoyancy (LCB is chosen as the design parameter. The adjusting of LCB is achieved by changing frame area curves, and hull surfaces are reconstructed accordingly using the Radial Basis Function (RBF. Surf-riding motions in regular following seas for cases with different LCBs and Froude numbers are simulated using the numerical model. Results show that the surf-riding cannot be prevented by the adjusting of LCB. However, it occurs with a higher threshold speed when ship's center of buoyancy (COB is moved towards stem compared to moving towards stern, which is mainly due to the differences on wave resistance caused by the adjusting of LCB.

  6. KARAKTERISTIK, MOTIVASI DAN NIAT WISATAWAN SURFING DI PANTAI KECAMATAN KUTA UTARA

    Directory of Open Access Journals (Sweden)

    Ni Putu Windy Pramita

    2017-04-01

    Full Text Available Black sandy beach tourist attraction of Kuta Northen region that is Batu Bolong beach and Batu Mejan beach which has potential a beautifull oncean, sunset, sunbathing and surfingthe purpose of this study was to determinethe characteristics, motivasi, and intentions rating surfing at Kuta Northen beach. The method used observation, questionnaires, interviews, literature study, and documentation. 213 respondens rating surfing with quantitative descriptive and regression linier analisys. The result obtained in this study are based on age characteristics surfing travelers will see the most travelers age between 18-29 years, male gender, country of origin Australia, and is a businessman, a master degree educational level, and marital status is not married. Surfing tourist motivation using push and pull factor with the highest scores on the social interaction. And Intention surfing tourist with the highest score there is positive world of mouth with Variabel tourist have the effect of 13,20% with a probability level of sig. 0,000, the motivation positive and significant efeect on the intention tourist but in small quantities. Therefore to improve the intention tourist come to the beach district of north kuta from the motivation pull and push should also improve the quality of beaches such as keeping the beach becomes the most importans thing that will directly make tourist feel comfortable. advice for managers is to add a lifeguard to keep the beach.

  7. Factors affecting surf zone phytoplankton production in Southeastern North Carolina, USA

    KAUST Repository

    Cahoon, Lawrence B.

    2017-07-15

    Abstract: The biomass and productivity of primary producers in the surf zone of the ocean beach at Wrightsville Beach, North Carolina, USA, were measured during all seasons, along with environmental parameters and nutrient levels. Variation in biomass (chlorophyll a) was associated with temperature. Primary production (PP), measured by in situ 14-C incubations, was a function of chlorophyll a, tide height at the start of incubations, and rainfall in the preceding 24-hr period. Biomass-normalized production (PB) was also a function of tide height and rainfall in the preceding 24-hr period. We interpreted these results as evidence of surf production 1) as combined contributions of phytoplankton and suspended benthic microalgae, which may confound application of simple P-E models to surf zone production, and 2) being regulated by nutrient source/supply fluctuations independently from other factors. Surf zone biomass and production levels are intermediate between relatively high estuarine values and much lower coastal ocean values. Surf zone production may represent an important trophic connection between these two important ecosystems.

  8. Computing OpenSURF on OpenCL and General Purpose GPU

    Directory of Open Access Journals (Sweden)

    Wanglong Yan

    2013-10-01

    Full Text Available Speeded-Up Robust Feature (SURF algorithm is widely used for image feature detecting and matching in computer vision area. Open Computing Language (OpenCL is a framework for writing programs that execute across heterogeneous platforms consisting of CPUs, GPUs, and other processors. This paper introduces how to implement an open-sourced SURF program, namely OpenSURF, on general purpose GPU by OpenCL, and discusses the optimizations in terms of the thread architectures and memory models in detail. Our final OpenCL implementation of OpenSURF is on average 37% and 64% faster than the OpenCV SURF v2.4.5 CUDA implementation on NVidia's GTX660 and GTX460SE GPUs, repectively. Our OpenCL program achieved real-time performance (>25 Frames Per Second for almost all the input images with different sizes from 320*240 to 1024*768 on NVidia's GTX660 GPU, NVidia's GTX460SE GPU and AMD's Radeon HD 6850 GPU. Our OpenCL approach on NVidia's GTX660 GPU is more than 22.8 times faster than its original CPU version on Intel's Dual-Core E5400 2.7G on average.

  9. Computing OpenSURF on OpenCL and General Purpose GPU

    Directory of Open Access Journals (Sweden)

    Wanglong Yan

    2013-10-01

    Full Text Available Speeded-Up Robust Feature (SURF algorithm is widely used for image feature detecting and matching in computer vision area. Open Computing Language (OpenCL is a framework for writing programs that execute across heterogeneous platforms consisting of CPUs, GPUs, and other processors. This paper introduces how to implement an open-sourced SURF program, namely OpenSURF, on general purpose GPU by OpenCL, and discusses the optimizations in terms of the thread architectures and memory models in detail. Our final OpenCL implementation of OpenSURF is on average 37% and 64% faster than the OpenCV SURF v2.4.5 CUDA implementation on NVidia’s GTX660 and GTX460SE GPUs, repectively. Our OpenCL program achieved real-time performance (>25 Frames Per Second for almost all the input images with different sizes from 320*240 to 1024*768 on NVidia’s GTX660 GPU, NVidia’s GTX460SE GPU and AMD’s Radeon HD 6850 GPU. Our OpenCL approach on NVidia’s GTX660 GPU is more than 22.8 times faster than its original CPU version on Intel’s Dual-Core E5400 2.7G on average.

  10. Measuring and modeling suspended sediment concentration profiles in the surf zone

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Time-averaged suspended sediment concentration profiles across the surf zone were measured in a large-scale three-dimensional movable bed laboratory facility (LSTF:Large-scale Sediment Transport Facility). Sediment suspension under two different types of breaking waves, spilling and plunging breakers, was investigated. The magnitudes and shapes of the concentration profiles varied substantially at different locations across the surf zone, reflecting the different intensities of breaking-induced turbulence. Sediment sus- pension at the energetic plunging breaker-line was much more active, resulting in nearly homogeneous concentration profiles throughout most of the water column, as compared to the reminder of the surf zone and at the spilling breaker-line. Four suspended sediment concentration models were examined based on the LSTF data, including the mixing turbulence length approach, segment eddy viscosity model, breaking-induced wave-energy dissipation approach, and a combined breaking and turbulence length model developed by this study. Neglecting the breaking-induced turbulence and subsequent sediment mixing, suspended sediment concentration models failed to predict the across-shore variations of the sediment suspension, especially at the plunging breaker-line. Wave-energy dissipation rate provided an accurate method for estimating the intensity of turbulence generated by wave breaking. By incorporating the breaking-induced turbulence, the combined breaking and turbulence length model reproduced the across-shore variation of sediment suspension in the surf zone. The combined model reproduced the measured time-averaged suspended sediment concentration profiles reasonably well across the surf zone.

  11. Solar winds surfs waves in the Sun's atmosphere!

    Science.gov (United States)

    1999-07-01

    opposite ends after threading it through an object, like a ring. If one person wiggles the string rapidly up and down, waves form in the string that move toward the person at the other end. The ring will "surf" these waves and move toward the other person as well. Try it! "Even with this major discovery, there are questions left to answer. The observations have made it abundantly clear that heavy particles like oxygen 'surf' on the waves, and there is also mounting evidence that waves are responsible for accelerating the hydrogen atoms, the most common constituent of the solar wind. Future observations are needed to establish this fact. Many other kinds of particles, such as helium (second most common) have never been observed in the accelerating part of the corona, and new observations are also needed to refine our understanding of how the waves interact with the solar wind as a whole," said Dr. Steven Cranmer of the Harvard-Smithsonian Center for Astrophysics, lead author of the research to be published in the Astrophysical Journal*. Nevertheless, SOHO has again been able to reveal another of the Sun's mysteries: "This is another triumph for SOHO, stealing a long-held secret from our Sun", said Dr Martin Huber, Head of ESA Space Science Department and co-investigator for UVCS. *Ref. Article by S.Cranmer, G.B. Field and J.L. Kohl on Astrophysical Journal ( June 20, Vol 518, p. 937-947) available on the web at: http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v518n2/39802/sc0.html

  12. SURF'S UP! – Protein classification by surface comparisons

    Indian Academy of Sciences (India)

    Joanna M Sasin; Adam Godzik; Janusz M Bujnicki

    2007-01-01

    Large-scale genome sequencing and structural genomics projects generate numerous sequences and structures for ‘hypothetical’ proteins without functional characterizations. Detection of homology to experimentally characterized proteins can provide functional clues, but the accuracy of homology-based predictions is limited by the paucity of tools for quantitative comparison of diverging residues responsible for the functional divergence. SURF’S UP! is a web server for analysis of functional relationships in protein families, as inferred from protein surface maps comparison according to the algorithm. It assigns a numerical score to the similarity between patterns of physicochemical features (charge, hydrophobicity) on compared protein surfaces. It allows recognizing clusters of proteins that have similar surfaces, hence presumably similar functions. The server takes as an input a set of protein coordinates and returns files with ``spherical coordinates” of proteins in a PDB format and their graphical presentation, a matrix with values of mutual similarities between the surfaces, and the unrooted tree that represents the clustering of similar surfaces, calculated by the neighbor-joining method. SURF’S UP! facilitates the comparative analysis of physicochemical features of the surface, which are the key determinants of the protein function. By concentrating on coarse surface features, SURF’S UP! can work with models obtained from comparative modelling. Although it is designed to analyse the conservation among homologs, it can also be used to compare surfaces of non-homologous proteins with different three-dimensional folds, as long as a functionally meaningful structural superposition is supplied by the user. Another valuable characteristic of our method is the lack of initial assumptions about the functional features to be compared. SURF’S UP! is freely available for academic researchers at http://asia.genesilico.pl/surfs_up/.

  13. Scaled photographs of surf over the full range of breaker sizes on the north shore of Oahu and Jaws, Maui, Hawaiian Islands (NODC Accession 0001753)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Digital surf photographs were scaled using surfers as height benchmarks to estimate the size of the breakers. Historical databases for surf height in Hawaii are...

  14. A Novel Image Retrieval Based on Visual Words Integration of SIFT and SURF.

    Directory of Open Access Journals (Sweden)

    Nouman Ali

    Full Text Available With the recent evolution of technology, the number of image archives has increased exponentially. In Content-Based Image Retrieval (CBIR, high-level visual information is represented in the form of low-level features. The semantic gap between the low-level features and the high-level image concepts is an open research problem. In this paper, we present a novel visual words integration of Scale Invariant Feature Transform (SIFT and Speeded-Up Robust Features (SURF. The two local features representations are selected for image retrieval because SIFT is more robust to the change in scale and rotation, while SURF is robust to changes in illumination. The visual words integration of SIFT and SURF adds the robustness of both features to image retrieval. The qualitative and quantitative comparisons conducted on Corel-1000, Corel-1500, Corel-2000, Oliva and Torralba and Ground Truth image benchmarks demonstrate the effectiveness of the proposed visual words integration.

  15. A Novel Image Retrieval Based on Visual Words Integration of SIFT and SURF.

    Science.gov (United States)

    Ali, Nouman; Bajwa, Khalid Bashir; Sablatnig, Robert; Chatzichristofis, Savvas A; Iqbal, Zeshan; Rashid, Muhammad; Habib, Hafiz Adnan

    2016-01-01

    With the recent evolution of technology, the number of image archives has increased exponentially. In Content-Based Image Retrieval (CBIR), high-level visual information is represented in the form of low-level features. The semantic gap between the low-level features and the high-level image concepts is an open research problem. In this paper, we present a novel visual words integration of Scale Invariant Feature Transform (SIFT) and Speeded-Up Robust Features (SURF). The two local features representations are selected for image retrieval because SIFT is more robust to the change in scale and rotation, while SURF is robust to changes in illumination. The visual words integration of SIFT and SURF adds the robustness of both features to image retrieval. The qualitative and quantitative comparisons conducted on Corel-1000, Corel-1500, Corel-2000, Oliva and Torralba and Ground Truth image benchmarks demonstrate the effectiveness of the proposed visual words integration.

  16. Environmental Awareness of Surf Tourists: A Case Study in the Algarve

    Directory of Open Access Journals (Sweden)

    Fabia Frank

    2015-06-01

    Full Text Available Even though surf tourism in Portugal is an economic activity with a steady growth rate, there are not many assessment studies available. Using a survey undertaken in surf camps located in the Vila do Bispo County, this study aims to analyse the environmental awareness of surf tourists in the Algarve. Through the New Environmental Paradigm (NEP scale it is shown that the environmental attitudes of respondents are strongly pro-ecological but also reveal some anthropocentric aspects. Tourists were asked about their willingness to pay for an accommodation tax earmarked for environmental protection in the Algarve. The results show that the large majority (86% would be willing to pay, which indicates a high environmental awareness. It is also found that the willingness to pay is related to the nationality, with respondents from Germany, Austria and Switzerland showing a higher willingness to pay.

  17. Loss-of-function mutations of SURF-1 are specifically associated with Leigh syndrome with cytochrome c oxidase deficiency.

    Science.gov (United States)

    Tiranti, V; Jaksch, M; Hofmann, S; Galimberti, C; Hoertnagel, K; Lulli, L; Freisinger, P; Bindoff, L; Gerbitz, K D; Comi, G P; Uziel, G; Zeviani, M; Meitinger, T

    1999-08-01

    Mutations of SURF-1, a gene located on chromosome 9q34, have recently been identified in patients affected by Leigh syndrome (LS), associated with deficiency of cytochrome c oxidase (COX), the terminal component of the mitochondrial respiratory chain. To investigate to what extent SURF-1 is responsible for human disorders because of COX deficiency, we undertook sequence analysis of the SURF-1 gene in 46 unrelated patients. We analyzed 24 COX-defective patients classified as having typical Leigh syndrome (LS(COX)), 6 patients classified as Leigh-like (LL(COX)) cases, and 16 patients classified as non-LS(COX) cases. Frameshift, stop, and splice mutations of SURF-1 were detected in 18 of 24 (75%) of the LS(COX) cases. No mutations were found in the LL(COX) and non-LS(COX) group of patients. Rescue of the COX phenotype was observed in transfected cells from patients harboring SURF-1 mutations, but not in transfected cell lines from 2 patients in whom no mutations were detected by sequence analysis. Loss of function of SURF-1 protein is specifically associated with LS(COX), although a proportion of LS(COX) cases must be the result of abnormalities in genes other than SURF-1. SURF-1 is the first nuclear gene to be consistently mutated in a major category of respiratory chain defects. DNA analysis can now be used to accurately diagnose LS(COX), a common subtype of Leigh syndrome.

  18. Heart Rate Responses of High School Students Participating in Surfing Physical Education.

    Science.gov (United States)

    Bravo, Michelle M; Cummins, Kevin M; Nessler, Jeff A; Newcomer, Sean C

    2016-06-01

    Despite the nation's rising epidemic of childhood obesity and diabetes, schools struggle to promote physical activities that help reduce risks for cardiovascular disease. Emerging data suggest that adopting novel activities into physical education (PE) curriculum may serve as an effective strategy for increasing physical activity in children. The purpose of this investigation was to characterize activity in the water and heart rates (HRs) of high school students participating in surf PE courses. Twenty-four male (n = 20) and female (n = 4) high school students (mean age = 16.7 ± 1.0 years) who were enrolled in surf PE courses at 2 high schools participated in this investigation. Daily measurements of surfing durations, average HR, and maximum HR were made on the students with HR monitors (PolarFT1) over an 8-week period. In addition, HR and activity in the water was evaluated during a single session in a subset of students (n = 11) using a HR monitor (PolarRCX5) and a video camera (Canon HD). Activity and HR were synchronized and evaluated in 5-second intervals during data analyses. The average duration that PE students participated in surfing during class was 61.7 ± 1.0 minutes. Stationary, paddling, wave riding, and miscellaneous activities comprised 42.7 ± 9.5, 36.7 ± 7.9, 2.9 ± 1.4, and 17.8 ± 11.4 percent of the surf session, respectively. The average and maximum HRs during these activities were 131.1 ± 0.9 and 177.2 ± 1.0 b·min, respectively. These data suggest that high school students participating in surf PE attained HRs and durations that are consistent with recommendations with cardiovascular fitness and health. In the future, PE programs should consider incorporating other action sports into their curriculum to enhance cardiovascular health.

  19. Run-up of tsunamis and long waves in terms of surf-similarity

    DEFF Research Database (Denmark)

    Madsen, Per A.; Fuhrman, David R.

    2008-01-01

    of the surf-similarity parameter and the amplitude to depth ratio determined at some offshore location. We use the analytical expressions to analyze the impact of tsunamis on beaches and relate the discussion to the recent Indian Ocean tsunami from December 26, 2004. An important conclusion is that extreme...... run-up combined with extreme flow velocities occurs for surf-similarity parameters of the order 3-6, and for typical tsunami wave periods this requires relatively mild beach slopes. Next, we compare the theoretical solutions to measured run-up of breaking and non-breaking irregular waves on steep...

  20. SURF: Taking Sustainable Remediation from Concept to Standard Operating Procedure (Invited)

    Science.gov (United States)

    Smith, L. M.; Wice, R. B.; Torrens, J.

    2013-12-01

    Over the last decade, many sectors of industrialized society have been rethinking behavior and re-engineering practices to reduce consumption of energy and natural resources. During this time, green and sustainable remediation (GSR) has evolved from conceptual discussions to standard operating procedure for many environmental remediation practitioners. Government agencies and private sector entities have incorporated GSR metrics into their performance criteria and contracting documents. One of the early think tanks for the development of GSR was the Sustainable Remediation Forum (SURF). SURF brings together representatives of government, industry, consultancy, and academia to parse the means and ends of incorporating societal and economic considerations into environmental cleanup projects. Faced with decades-old treatment programs with high energy outputs and no endpoints in sight, a small group of individuals published the institutional knowledge gathered in two years of ad hoc meetings into a 2009 White Paper on sustainable remediation drivers, practices, objectives, and case studies. Since then, SURF has expanded on those introductory topics, publishing its Framework for Integrating Sustainability into Remediation Projects, Guidance for Performing Footprint Analyses and Life-Cycle Assessments for the Remediation Industry, a compendium of metrics, and a call to improve the integration of land remediation and reuse. SURF's research and members have also been instrumental in the development of additional guidance through ASTM International and the Interstate Technology and Regulatory Council. SURF's current efforts focus on water reuse, the international perspective on GSR (continuing the conversations that were the basis of SURF's December 2012 meeting at the National Academy of Sciences in Washington, DC), and ways to capture and evaluate the societal benefits of site remediation. SURF also promotes and supports student chapters at universities across the US

  1. The Ocean as a Unique Therapeutic Environment: Developing a Surfing Program

    Science.gov (United States)

    Clapham, Emily D.; Armitano, Cortney N.; Lamont, Linda S.; Audette, Jennifer G.

    2014-01-01

    Educational aquatic programming offers necessary physical activity opportunities to children with disabilities and the benefits of aquatic activities are more pronounced for children with disabilities than for their able-bodied peers. Similar benefits could potentially be derived from surfing in the ocean. This article describes an adapted surfing…

  2. Modelling Vertical Variation of Turbulent Flow Across a Surf Zone Using SWASH

    NARCIS (Netherlands)

    Zijlema, M.

    2014-01-01

    This paper presents the application of the open source non-hydrostatic wave-flow model SWASH to propagation of irregular waves in a barred surf zone, and the model results are discussed by comparing against an extensive laboratory data set. This study focus not only on wave transformation in the sur

  3. Post-Processing Enhancement of Reverberation-Noise Suppression in Dual-Frequency SURF Imaging

    CERN Document Server

    Nasholm, Sven Peter; Angelsen, Bjørn A J; 10.1109/TUFFC.2011.1811

    2013-01-01

    A post-processing adjustment technique which aims for enhancement of dual-frequency SURF (Second order UltRasound Field) reverberation-noise suppression imaging in medical ultrasound is analyzed. Two variant methods are investigated through numerical simulations. They both solely involve post-processing of the propagated high-frequency (HF) imaging wave fields, which in real-time imaging corresponds to post-processing of the beamformed receive radio-frequency signals. Hence the transmit pulse complexes are the same as for the previously published SURF reverberation-suppression imaging method. The adjustment technique is tested on simulated data from propagation of SURF pulse complexes consisting of a 3.5 MHz HF imaging pulse added to a 0.5 low-frequency sound-speed manipulation pulse. Imaging transmit beams are constructed with and without adjustment. The post-processing involves filtering, e.g., by a time-shift, in order to equalize the two SURF HF pulses at a chosen depth. This depth is typically chosen to ...

  4. The Ocean as a Unique Therapeutic Environment: Developing a Surfing Program

    Science.gov (United States)

    Clapham, Emily D.; Armitano, Cortney N.; Lamont, Linda S.; Audette, Jennifer G.

    2014-01-01

    Educational aquatic programming offers necessary physical activity opportunities to children with disabilities and the benefits of aquatic activities are more pronounced for children with disabilities than for their able-bodied peers. Similar benefits could potentially be derived from surfing in the ocean. This article describes an adapted surfing…

  5. Implementing CHC to Counter Shoulder Surfing Attack in PassPoint – Style Graphical Passwords

    Directory of Open Access Journals (Sweden)

    M. Joshuva

    2011-05-01

    Full Text Available Graphical passwords are an alternative to existing alphanumeric passwords. In Graphical passwords users click on images than type a long, complex password. Passpoints scheme is one of the Graphical user authentication techniques. In this method the password is represented by multiple clicks on a single image. One of the advantages with Passpoints scheme is that, a user can click on any place in the image as a click point. Graphical authentication suffers a major drawback of Shoulder-surfing. Shoulder-surfing refers to someone observing the user’s action as the user enters a password. Due to this, the user’s action can be monitored by the attacker or it can be captured using recording devices such as camera. Sobrado and Birget suggested Convex Hull Click (CHC scheme to counter shoulder-surfing using PassIcons which is different from PassPoint scheme. In this paper, we described how CHC is implemented in Passpoint-sheme to counter Shoulder Surfing Attack.

  6. Performance differences between sexes in the pop-up phase of surfing.

    Science.gov (United States)

    Eurich, Alea D; Brown, Lee E; Coburn, Jared W; Noffal, Guillermo J; Nguyen, Diamond; Khamoui, Andy V; Uribe, Brandon P

    2010-10-01

    Surfing is a dynamic sport that is multidirectional in nature and requires peak performance in variable ocean conditions. Its growing popularity among the female population has stirred curiosity as to whether women can and will 1 day face their male counterparts in head-to-head competition at the top levels. The purpose of this study was to examine male and female differences in performance of a simulated surfing pop-up movement. Forty recreationally trained surfers (20 men and 20 women) were instructed to lie prone on a force plate, in the pop-up position (similar to a push-up), with only their hands in contact with the plate. A velocity transducer was attached to their back via an adjustable strap around their upper trunk. They completed 3 pop-ups as explosively as possible by pushing forcefully with their hands and jumping to their feet. Absolute and relative force and power were measured. Results demonstrated that men exhibited significantly (p pop-up movement. It appears that women may be at a disadvantage in regards to peak performance when compared to their male counterparts in the surfing pop-up movement. Therefore, women should train for both maximum and explosive upper-body strength in addition to their time spent surfing.

  7. Robust Object-Based Watermarking Using SURF Feature Matching and DFT Domain

    Directory of Open Access Journals (Sweden)

    M. Cedillo-Hernandez

    2013-12-01

    Full Text Available In this paper we propose a robust object-based watermarking method, in which the watermark is embedded into the middle frequencies band of the Discrete Fourier Transform (DFT magnitude of the selected object region, altogether with the Speeded Up Robust Feature (SURF algorithm to allow the correct watermark detection, even if the watermarked image has been distorted. To recognize the selected object region after geometric distortions, during the embedding process the SURF features are estimated and stored in advance to be used during the detection process. In the detection stage, the SURF features of the distorted image are estimated and match them with the stored ones. From the matching result, SURF features are used to compute the Affine-transformation parameters and the object region is recovered. The quality of the watermarked image is measured using the Peak Signal to Noise Ratio (PSNR, Structural Similarity Index (SSIM and the Visual Information Fidelity (VIF. The experimental results show the proposed method provides robustness against several geometric distortions, signal processing operations and combined distortions. The receiver operating characteristics (ROC curves also show the desirable detection performance of the proposed method. The comparison with a previously reported methods based on different techniques is also provided.

  8. Baseline Measurements of Shoulder Surfing Analysis and Comparability for Smartphone Unlock Authentication

    Science.gov (United States)

    2017-05-22

    lines, and graphical patterns without lines) in a controlled setting . These videos are designed to simulate shoulder surfing settings under varied attack...than triple the success rate with a single view at 72.44 . The goal of this research is to identify more effective guidance for mobile device users to

  9. Constitutive knockout of Surf1 is associated with high embryonic lethality, mitochondrial disease and cytochrome c oxidase deficiency in mice.

    Science.gov (United States)

    Agostino, Alessandro; Invernizzi, Federica; Tiveron, Cecilia; Fagiolari, Gigliola; Prelle, Alessandro; Lamantea, Eleonora; Giavazzi, Alessio; Battaglia, Giorgio; Tatangelo, Laura; Tiranti, Valeria; Zeviani, Massimo

    2003-02-15

    We report here the creation of a constitutive knockout mouse for SURF1, a gene encoding one of the assembly proteins involved in the formation of cytochrome c oxidase (COX). Loss-of-function mutations of SURF1 cause Leigh syndrome associated with an isolated and generalized COX deficiency in humans. The murine phenotype is characterized by the following hallmarks: (1) high post-implantation embryonic lethality, affecting approximately 90% of the Surf1(-/-) individuals; (2) early-onset mortality of post-natal individuals; (3) highly significant deficit in muscle strength and motor performance; (4) profound and isolated defect of COX activity in skeletal muscle and liver, and, to a lesser extent, heart and brain; (5) morphological abnormalities of skeletal muscle, characterized by reduced histochemical reaction to COX and mitochondrial proliferation; (6) no obvious abnormalities in brain morphology, reflecting the virtual absence of overt neurological symptoms. These results indicate a function for murine Surf1 protein (Surf1p) specifically related to COX and recapitulate, at least in part, the human phenotype. This is the first mammalian model for a nuclear disease gene of a human mitochondrial disorder. Our model constitutes a useful tool to investigate the function of Surf1p, help understand the pathogenesis of Surf1p deficiency in vivo, and evaluate the efficacy of treatment.

  10. Measuring and modeling suspended sediment concentration profiles in the surf zone

    Directory of Open Access Journals (Sweden)

    Ping Wang

    2012-10-01

    Full Text Available Time-averaged suspended sediment concentration profiles across the surf zone were measured in a large-scale three-dimensional movable bed laboratory facility (LSTF: Large-scale Sediment Transport Facility. Sediment suspension under two different types of breaking waves, spilling and plunging breakers, was investigated. The magnitudes and shapes of the concentration profiles varied substantially at different locations across the surf zone, reflecting the different intensities of breaking-induced turbulence. Sediment suspension at the energetic plunging breaker-line was much more active, resulting in nearly homogeneous concentration profiles throughout most of the water column, as compared to the reminder of the surf zone and at the spilling breaker-line. Four suspended sediment concentration models were examined based on the LSTF data, including the mixing turbulence length approach, segment eddy viscosity model, breaking-induced wave-energy dissipation approach, and a combined breaking and turbulence length model developed by this study. Neglecting the breaking-induced turbulence and subsequent sediment mixing, suspended sediment concentration models failed to predict the across-shore variations of the sediment suspension, especially at the plunging breaker-line. Wave-energy dissipation rate provided an accurate method for estimating the intensity of turbulence generated by wave breaking. By incorporating the breaking-induced turbulence, the combined breaking and turbulence length model reproduced the across-shore variation of sediment suspension in the surf zone. The combined model reproduced the measured time-averaged suspended sediment concentration profiles reasonably well across the surf zone.

  11. Assessments Of Different Speeded Up Robust Features (SURF Algorithm Resolution For Pose Estimation Of UAV

    Directory of Open Access Journals (Sweden)

    Bassem Sheta

    2012-11-01

    Full Text Available The UAV industry is growing rapidly in an attempt to serve both military and commercial applications. A crucial aspect in the development of UAVs is the reduction of navigational sensor costs while maintaining accurate navigation. Advances in visual sensor solutions with traditional navigation sensors are proving to be significantly promising in replacing traditional IMU or GPS systems for many mission scenarios. The basic concept behind Vision Based Navigation (VBN is to find the matches between a set of features in real-time captured images taken by the imaging sensor on the UAV and database images. A scale and rotation invariant image matching algorithm is a key element for VBN of aerial vehicles. Matches between the geo-referenced database images and the new real-time captured ones are determined by employing the fast Speeded Up Robust Features (SURF algorithm. The SURF algorithm consists mainly of two steps: the first is the detection of points of interest and the second is the creation of descriptors for each of these points. In this research paper, two major factors are investigated and tested to efficiently create the descriptors for each point of interest. The first factor is the dimension of the descriptor for a given point of interest. The dimension is affected by the number of descriptor sub-regions which consequently affects the matching time and the accuracy. SURF performance has been investigated and tested using different dimensions of the descriptor. The second factor is the number of sample points in each sub-region which are used to build the descriptor of the point of interest. SURF performance has been investigated and tested by changing thenumber of sample points in each sub-region where the matching accuracy is affected. Assessments of the SURF performance and consequently on UAV VBN are investigated.

  12. "Do outside": corpo e natureza, medo e gênero no surfe universitário paulistano "From the outside": body and nature, fear and gender in surfing

    Directory of Open Access Journals (Sweden)

    Marília Martins Bandeira

    2011-03-01

    Full Text Available Ao objetivo primeiro desta pesquisa, descrever as dinâmicas do surfe e os significados de sua prática, em especial a relação ser humano/natureza estabelecida por meio do esporte, somaram-se outros objetivos: problematizar a aproximação do pesquisador de seu campo de investigação, a possibilidade de um pesquisador realizar uma investigação através de seu próprio corpo e discutir a questão de gênero no surfe. Sobre o objetivo primeiro desta pesquisa, vivendo e descrevendo as dinâmicas do surfe encontrou-se os significados da relação do surfista com o mar nas sensações corporais experimentadas nas técnicas do remar, sentar, dar o joelhinho e dropar a onda. Que ser capaz de passar a rebentação é associado a um retorno bem sucedido à comunhão do homem com a natureza, sendo as cores, formas e sensações do "outside" o privilégio daquele que vence as dificuldades do tornar-se e ser surfista. Mas, que estas sensações são tidas como possibilidades de corpos corajosos e hábeis, "a priori", entendidos como corpos masculinos. O surfe como campo em que o feminino é visto ainda como exceção dá a pensar que os esportes na natureza e a educação ao ar livre, embora tenham potencial de promover novas condutas políticas e a virtuosa sensibilidade ambiental, não estão livres de reproduzir outros padrões de dominação.The main goal of this research is to describe the dynamics of surfing and its meanings, mainly the human/nature relation established through the sport. Meanwhile, other goals were added: discussing the approach to the field by the researcher, the possibility this researcher could investigate through her own body and the gender matter in the sport. About the main aim of the research, living and experiencing the sport itself, meaning, to the relation between the surfer and the sea, was found in the body sensations experienced through techniques such as paddling, sitting, duck diving and dropping a wave. Being

  13. Spatially Uniform ReliefF (SURF for computationally-efficient filtering of gene-gene interactions

    Directory of Open Access Journals (Sweden)

    Greene Casey S

    2009-09-01

    Full Text Available Abstract Background Genome-wide association studies are becoming the de facto standard in the genetic analysis of common human diseases. Given the complexity and robustness of biological networks such diseases are unlikely to be the result of single points of failure but instead likely arise from the joint failure of two or more interacting components. The hope in genome-wide screens is that these points of failure can be linked to single nucleotide polymorphisms (SNPs which confer disease susceptibility. Detecting interacting variants that lead to disease in the absence of single-gene effects is difficult however, and methods to exhaustively analyze sets of these variants for interactions are combinatorial in nature thus making them computationally infeasible. Efficient algorithms which can detect interacting SNPs are needed. ReliefF is one such promising algorithm, although it has low success rate for noisy datasets when the interaction effect is small. ReliefF has been paired with an iterative approach, Tuned ReliefF (TuRF, which improves the estimation of weights in noisy data but does not fundamentally change the underlying ReliefF algorithm. To improve the sensitivity of studies using these methods to detect small effects we introduce Spatially Uniform ReliefF (SURF. Results SURF's ability to detect interactions in this domain is significantly greater than that of ReliefF. Similarly SURF, in combination with the TuRF strategy significantly outperforms TuRF alone for SNP selection under an epistasis model. It is important to note that this success rate increase does not require an increase in algorithmic complexity and allows for increased success rate, even with the removal of a nuisance parameter from the algorithm. Conclusion Researchers performing genetic association studies and aiming to discover gene-gene interactions associated with increased disease susceptibility should use SURF in place of ReliefF. For instance, SURF should be

  14. Drones at the Beach - Surf Zone Monitoring Using Rotary Wing Unmanned Aerial Vehicles

    Science.gov (United States)

    Rynne, P.; Brouwer, R.; de Schipper, M. A.; Graham, F.; Reniers, A.; MacMahan, J. H.

    2014-12-01

    We investigate the potential of rotary wing Unmanned Aerial Vehicles (UAVs) to monitor the surf zone. In recent years, the arrival of lightweight, high-capacity batteries, low-power electronics and compact high-definition cameras has driven the development of commercially available UAVs for hobbyists. Moreover, the low operation costs have increased their potential for scientific research as these UAVs are extremely flexible surveying platforms. The UAVs can fly for ~12 min with a mean loiter radius of 1 - 3.5 m and a mean loiter error of 0.75 - 4.5 m, depending on the environmental conditions, flying style, battery type and vehicle type. Our experiments using multiple, alternating UAVs show that it is possible to have near continuous imagery data with similar Fields Of View. The images obtained from the UAVs (Fig. 1a), and in combination with surveyed Ground Control Points (GCPs) (Fig. 1b, red squares and white circles), can be geo-rectified (Fig. 1c) to pixel resolution between 0.01 - 1 m and a reprojection error, i.e. the difference between the surveyed GPS location of a GCP and the location of the GCP obtained from the geo-rectified image, of O(1 m). These geo-rectified images provide data on a variety of coastal aspects, such as beach width (Wb(x,t)), surf zone width (Wsf(x,t)), wave breaking location (rectangle B), beach usage (circle C) and location of dune vegegation (rectangle D), amongst others. Additionally, the possibility to have consecutive, high frequency (up to 2 Hz) rectified images makes the UAVs a great data instrument for spatially and temporally variable systems, such as the surf zone. Our first observations with the UAVs reveal the potential to quickly obtain surf zone and beach characteristics in response to storms or for day to day beach information, as well as the scientific pursuits of surf zone kinematics on different spatial and temporal scales, and dispersion and advection estimates of pollutants/dye. A selection of findings from

  15. Surf observations from the South Shore of Oahu, Hawaii from 01 March 1972 to 20 November 1987 (NODC Accession 0000274)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Heights of breaking surf were collected by using visual observations from swimmers or divers at the South Shore of Oahu, Hawaii from March 1, 1972 to November 20,...

  16. Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic). SURF CLAM

    Science.gov (United States)

    1983-10-01

    invisible, outer, jellylike layer and mine surf clam gender (Ropes et al. the germinal vesicle (Ropes 1980). 1969). Male and female surf clams Longo...Jacobsen, M. K., and W. E. Old, Jr. Lindley, M. G., and R. S. Shallen- 1966. On the identity of Spisula berger. 1976, Purification and similis. Am...1966. A quantitative Masse, H. 1975. Feeding biotogy of .3-year-survey on the meiofauna Astropecten aranciacus. Cah , of known macrofauna communities

  17. SurfKin: an ab initio kinetic code for modeling surface reactions.

    Science.gov (United States)

    Le, Thong Nguyen-Minh; Liu, Bin; Huynh, Lam K

    2014-10-05

    In this article, we describe a C/C++ program called SurfKin (Surface Kinetics) to construct microkinetic mechanisms for modeling gas-surface reactions. Thermodynamic properties of reaction species are estimated based on density functional theory calculations and statistical mechanics. Rate constants for elementary steps (including adsorption, desorption, and chemical reactions on surfaces) are calculated using the classical collision theory and transition state theory. Methane decomposition and water-gas shift reaction on Ni(111) surface were chosen as test cases to validate the code implementations. The good agreement with literature data suggests this is a powerful tool to facilitate the analysis of complex reactions on surfaces, and thus it helps to effectively construct detailed microkinetic mechanisms for such surface reactions. SurfKin also opens a possibility for designing nanoscale model catalysts.

  18. Experimental and numerical investigation of the internal kinetics of a surf-zone plunging breaker

    DEFF Research Database (Denmark)

    Emarat, Narumon; Forehand, David I.M.; Christensen, Erik Damgaard

    2012-01-01

    Over the last couple of decades both the qualitative and quantitative understanding of breaking waves in the surf zone have greatly increased. This is due to the advances in experimental and numerical techniques. However, few comparisons between these two different investigative techniques...... for surfzone breaking waves have been reported. In this study, a comparison is made between the experimental and numerical investigation of the internal kinematics of a surf-zone plunging breaker. The full-field velocity measuring technique known as Particle Image Velocimetry (PIV) is used in the experiments....... In the hybrid numerical scheme, the main model solves the Navier–Stokes equations using a Finite Volume method and the free-surface is simulated using a Volume of Fluid (VOF) method. An important feature of this work is that, unlike in most other comparisons between numerical and experimental results, the exact...

  19. An Improvement of Positional Accuracy for View-Based Navigation Using SURF

    Science.gov (United States)

    Hagiwara, Yoshinobu; Imamura, Hiroki; Choi, Yongwoon; Watanabe, Kazuhiro

    In this paper, we propose a reliable method for view-based navigation of mobile robots fully improved in positional accuracy by using feature-points extracted by SURF, and it is verified from the navigation experiments of them. View-based navigations that have used block matching method are not enough in positional accuracy for robots to avoid obstacles and pass narrow doorways. By applying SURF that is stable to illumination and scale changes in an image to the method for view-based navigation, the navigation for robots becomes more robust to variable indoor conditions. In experiments conducted in an indoor corridor with a robot for comparing the proposed method to conventional one, the positional precision was obtained in centimeter-order of within 10.0[cm]. In this view, it suggests that the proposed method is applied to the view-based navigation for robots in such narrow areas as obstacle avoidance and corridors.

  20. Sobre as ondas: surfe, juventude e cultura no Rio de Janeiro dos anos 1960

    Directory of Open Access Journals (Sweden)

    Cleber Dias

    2012-06-01

    Full Text Available Na segunda metade do século XX, torna-se explícita a influência mundial dos Estados Unidos no âmbito esportivo. A disseminação de práticas que possuíam marcas culturais norte-americanas, como é o caso do surfe, não deve ser considerada, contudo, somente como resultado de uma imposição unilateral: há múltiplas apropriações locais que dizem muito sobre o contexto do receptor. Partindo dessa consideração, este artigo objetiva discutir a apreensão do surfe no Rio de Janeiro dos anos 1960. Buscamos debater como a modalidade foi operada como marcador de identidades a partir de vinculações a certas noções de juventude e estilo de vida.

  1. On trend and on the wave: carving cultural identity through active surf dress

    OpenAIRE

    Anderson, Jonathan Mark

    2015-01-01

    Clothing, as both functional and fashionable, has become a key marker in signifying and shaping personal identity. This is particularly clear in a range of “lifestyle sports” [Wheaton, B. 2004. “Introduction: Mapping the Lifestyle Sportscape.” In Understanding Lifestyle Sports: Consumption, Identity, and Difference, edited by B. Wheaton, 1–28. London: Routledge], including the array of practices associated with the culture of surfing. This paper examines the ways in which companies market per...

  2. "Sub-Surf Rocks"! An A-Level Resource Developed through an Industry-Education Collaboration

    Science.gov (United States)

    Mather, Hazel

    2012-01-01

    A free internet resource called "Sub-Surf Rocks"! was launched in 2010. Its aim is to use seismic data obtained by the oil industry for enhancing the teaching of structural and economic geology at A-level (ages 16-18) in the UK. Seismic data gives a unique insight into the sub-surface and the many high-quality images coupled with…

  3. Effects of water temperature change on immune function in surf clams, Mactra veneriformis (Bivalvia: Mactridae).

    Science.gov (United States)

    Yu, Jin Ha; Song, Jae Hee; Choi, Min Chul; Park, Sung Woo

    2009-09-01

    Surf clam, Mactra veneriformis is one of the crucial fishery resources in Korea. This study was performed to examine the immune functions of the surf clam under the stress of water temperature changes at 10 degrees C, 20 degrees C or 30 degrees C for 24h. Viable bacterial counts (VBC), total haemocyte count (THC), phagocytic activity, lysozyme activity, NRR times and SOD activity were assessed in three different water temperature groups. Clams held at 10 degrees C decreased in THC, lysozyme activity and NRR times, but phagocytic activity was increased. The highest temperature (30 degrees C) significantly increased in THC, whereas it decreased in phagocytic activity, lysozyme activity and NRR times. In clams maintained at 20 degrees C, phagocytic activity, lysozyme activity and NRR times were increased whereas THC was somewhat decreased with respect to clams held at 30 degrees C. However, water temperature changes did not elicit any alteration of VBC and SOD activity. The present study demonstrates that acute water temperature change affects the haemocytic and haemolymphatic functions, reducing immunosurveillance in stressed surf clam, M. veneriformis.

  4. Mutations in the SURF1 gene associated with Leigh syndrome and cytochrome C oxidase deficiency.

    Science.gov (United States)

    Péquignot, M O; Dey, R; Zeviani, M; Tiranti, V; Godinot, C; Poyau, A; Sue, C; Di Mauro, S; Abitbol, M; Marsac, C

    2001-05-01

    Cytochrome c oxidase (COX) deficiency is one of the major causes of Leigh Syndrome (LS), a fatal encephalopathy of infancy or childhood, characterized by symmetrical lesions in the basal ganglia and brainstem. Mutations in the nuclear genes encoding COX subunits have not been found in patients with LS and COX deficiency, but mutations have been identified in SURF1. SURF1 encodes a factor involved in COX biogenesis. To date, 30 different mutations have been reported in 40 unrelated patients. We aim to provide an overview of all known mutations in SURF1, and to propose a common nomenclature. Twelve of the mutations were insertion/deletion mutations in exons 1, 4, 6, 8, and 9; 10 were missense/nonsense mutations in exons 2, 4, 5, 7, and 8; and eight were detected at splicing sites in introns 3 to 7. The most frequent mutation was 312_321del 311_312insAT which was found in 12 patients out of 40. Twenty mutations have been described only once. We also list all polymorphisms discovered to date.

  5. Does human pressure affect the community structure of surf zone fish in sandy beaches?

    Science.gov (United States)

    Costa, Leonardo Lopes; Landmann, Júlia G.; Gaelzer, Luiz R.; Zalmon, Ilana R.

    2017-01-01

    Intense tourism and human activities have resulted in habitat destruction in sandy beach ecosystems with negative impacts on the associated communities. To investigate whether urbanized beaches affect surf zone fish communities, fish and their benthic macrofaunal prey were collected during periods of low and high human pressure at two beaches on the Southeastern Brazilian coast. A BACI experimental design (Before-After-Control-Impact) was adapted for comparisons of tourism impact on fish community composition and structure in urbanized, intermediate and non-urbanized sectors of each beach. At the end of the summer season, we observed a significant reduction in fish richness, abundance, and diversity in the high tourist pressure areas. The negative association between visitors' abundance and the macrofaunal density suggests that urbanized beaches are avoided by surf zone fish due to higher human pressure and the reduction of food availability. Our results indicate that surf zone fish should be included in environmental impact studies in sandy beaches, including commercial species, e.g., the bluefish Pomatomus saltatrix. The comparative results from the less urbanized areas suggest that environmental zoning and visitation limits should be used as effective management and preservation strategies on beaches with high conservation potential.

  6. ConSurf 2016: an improved methodology to estimate and visualize evolutionary conservation in macromolecules.

    Science.gov (United States)

    Ashkenazy, Haim; Abadi, Shiran; Martz, Eric; Chay, Ofer; Mayrose, Itay; Pupko, Tal; Ben-Tal, Nir

    2016-07-08

    The degree of evolutionary conservation of an amino acid in a protein or a nucleic acid in DNA/RNA reflects a balance between its natural tendency to mutate and the overall need to retain the structural integrity and function of the macromolecule. The ConSurf web server (http://consurf.tau.ac.il), established over 15 years ago, analyses the evolutionary pattern of the amino/nucleic acids of the macromolecule to reveal regions that are important for structure and/or function. Starting from a query sequence or structure, the server automatically collects homologues, infers their multiple sequence alignment and reconstructs a phylogenetic tree that reflects their evolutionary relations. These data are then used, within a probabilistic framework, to estimate the evolutionary rates of each sequence position. Here we introduce several new features into ConSurf, including automatic selection of the best evolutionary model used to infer the rates, the ability to homology-model query proteins, prediction of the secondary structure of query RNA molecules from sequence, the ability to view the biological assembly of a query (in addition to the single chain), mapping of the conservation grades onto 2D RNA models and an advanced view of the phylogenetic tree that enables interactively rerunning ConSurf with the taxa of a sub-tree.

  7. CAMSHIFT IMPROVEMENT WITH MEAN-SHIFT SEGMENTATION, REGION GROWING, AND SURF METHOD

    Directory of Open Access Journals (Sweden)

    Ferdinan Ferdinan

    2013-10-01

    Full Text Available CAMSHIFT algorithm has been widely used in object tracking. CAMSHIFT utilizescolor features as the model object. Thus, original CAMSHIFT may fail when the object color issimilar with the background color. In this study, we propose CAMSHIFT tracker combined withmean-shift segmentation, region growing, and SURF in order to improve the tracking accuracy.The mean-shift segmentation and region growing are applied in object localization phase to extractthe important parts of the object. Hue-distance, saturation, and value are used to calculate theBhattacharyya distance to judge whether the tracked object is lost. Once the object is judged lost,SURF is used to find the lost object, and CAMSHIFT can retrack the object. The Object trackingsystem is built with OpenCV. Some measurements of accuracy have done using frame-basedmetrics. We use datasets BoBoT (Bonn Benchmark on Tracking to measure accuracy of thesystem. The results demonstrate that CAMSHIFT combined with mean-shift segmentation, regiongrowing, and SURF method has higher accuracy than the previous methods.

  8. Rip currents and alongshore flows in single channels dredged in the surf zone

    Science.gov (United States)

    Moulton, Melissa; Elgar, Steve; Raubenheimer, Britt; Warner, John C.; Kumar, Nirnimesh

    2017-05-01

    To investigate the dynamics of flows near nonuniform bathymetry, single channels (on average 30 m wide and 1.5 m deep) were dredged across the surf zone at five different times, and the subsequent evolution of currents and morphology was observed for a range of wave and tidal conditions. In addition, circulation was simulated with the numerical modeling system COAWST, initialized with the observed incident waves and channel bathymetry, and with an extended set of wave conditions and channel geometries. The simulated flows are consistent with alongshore flows and rip-current circulation patterns observed in the surf zone. Near the offshore-directed flows that develop in the channel, the dominant terms in modeled momentum balances are wave-breaking accelerations, pressure gradients, advection, and the vortex force. The balances vary spatially, and are sensitive to wave conditions and the channel geometry. The observed and modeled maximum offshore-directed flow speeds are correlated with a parameter based on the alongshore gradient in breaking-wave-driven-setup across the nonuniform bathymetry (a function of wave height and angle, water depths in the channel and on the sandbar, and a breaking threshold) and the breaking-wave-driven alongshore flow speed. The offshore-directed flow speed increases with dissipation on the bar and reaches a maximum (when the surf zone is saturated) set by the vertical scale of the bathymetric variability.

  9. Wave Height Distribution for Spilling Waves in and outside the Surf Zone

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The wave characteristics affecting coastal sediment transport include wave height, wave period and breaking wave direction. Wave height is a critical factor in determining the amount of sediment transport in the coastal area. The force of sediment transport is much more intense under breaking waves than under non-breaking waves. Breaking waves exhibit various patterns, principally depending on the incident wave steepness and the beach slope. Based on the equations of conservation of mass, momentum and energy, a theoretical model for wave deformation in and outside the surf zone was obtained, which is used to calculate the wave shoaling, wave set-up and setdown and wave height distributions in and outside the surf zone. The analysis and comparison were made about the breaking point location and the wave height decay caused by the wave breaking and the bottom friction. Flume experiments relating to the spilling wave height distribution across the surf zone were conducted to verify the theoretical model. Advanced wave maker, data sampling devices and data processing system were utilized in the flume experiments with a slope covered by sands of different diameters to facilitate the observation and research on the wave transformation and breaking. The agreement between the theoretical and experimental results is good.

  10. Rip currents and alongshore flows in single channels dredged in the surf zone

    Science.gov (United States)

    Moulton, Melissa; Elgar, Steve; Raubenheimer, Britt; Warner, John C.; Kumar, Nirnimesh

    2017-01-01

    To investigate the dynamics of flows near nonuniform bathymetry, single channels (on average 30 m wide and 1.5 m deep) were dredged across the surf zone at five different times, and the subsequent evolution of currents and morphology was observed for a range of wave and tidal conditions. In addition, circulation was simulated with the numerical modeling system COAWST, initialized with the observed incident waves and channel bathymetry, and with an extended set of wave conditions and channel geometries. The simulated flows are consistent with alongshore flows and rip-current circulation patterns observed in the surf zone. Near the offshore-directed flows that develop in the channel, the dominant terms in modeled momentum balances are wave-breaking accelerations, pressure gradients, advection, and the vortex force. The balances vary spatially, and are sensitive to wave conditions and the channel geometry. The observed and modeled maximum offshore-directed flow speeds are correlated with a parameter based on the alongshore gradient in breaking-wave-driven-setup across the nonuniform bathymetry (a function of wave height and angle, water depths in the channel and on the sandbar, and a breaking threshold) and the breaking-wave-driven alongshore flow speed. The offshore-directed flow speed increases with dissipation on the bar and reaches a maximum (when the surf zone is saturated) set by the vertical scale of the bathymetric variability.

  11. Zonation of macrofauna across sandy beaches and surf zones along the Dutch coast

    Directory of Open Access Journals (Sweden)

    Gerard Janssen

    2005-06-01

    Full Text Available On nine beaches and two transects in the surf zone along the Dutch coast the presence of benthic macrofauna was studied in relation to basic abiotic characteristics. According to Short's classification system, Dutch beaches are mesotidal and dissipative (Ω = 8.6, and the RTR is low (1.52-1.27, which means that they are not tide-dominated. BSI ranged from 1.4 to 1.1 for the northern and western Dutch coasts respectively and had an overall value of 1.2. The rates of exposure of the beaches varied between 8 and 12, and are therefore regarded as sheltered to moderately exposed. The Dutch beaches display a geographical trend in beach types. Those of the Wadden Sea islands in the northern part of the Netherlands are dissipative, flat, fine-grained, and host high densities of many species of benthic macrofauna. The beaches along the western Dutch coast are less dissipative, steeper, with a higher mean grain size; the species diversity and abundance there are lower. Species diversity and abundance on the beaches increase from the high- to the low-water line. The maximum number of species was found between 0 and -1 m relative to the mean tidal level. The abundance peaks just above the mean tidal level, while the biomass reaches a maximum at the mean tidal level.     Species diversity and abundance are low in the surf zone, but increase towards deeper water. Species numbers are high and the abundance is very high in the trough between the two bars.     The relation between the diversity and abundance of macrobenthic species on the one hand, and the sediment composition, water column depth, and position between the bars on the other show a clear pattern of zonation for the beach, surf zone and near-shore: (1 a supralittoral zone with insects and air-breathing crustaceans, (2 a midshore zone, with intertidal species, (3 a lower shore zone, whose species extend into the shallow surf zone, and (4 a zone of sublittoral fauna in the trough between the

  12. Surf zone fauna of Ecuadorian sandy beaches: Spatial and temporal patterns

    Science.gov (United States)

    Marin Jarrin, J. R.; Vanaverbeke, J.; Fockedey, N.; de Grunauer, M. del P. Cornejo R.; Dominguez-Granda, L.

    2017-02-01

    Sandy beaches and their surf zones are the most common open shoreline habitat; however, surf zone fauna in the tropics is one of the least studied communities in the world. In the current study, we tested the hypothesis that Ecuadorian surf zone hyperbenthos (invertebrates and vertebrates 1-5 mm in length) and epibenthos (fish and macrocrustaceans > 5 mm in length) vary among beaches and seasons. Therefore, the fauna was described and related to environmental variables. In addition, indicator taxa were identified. The hyperbenthos was divided into holo- and mero-hyperbenthos depending on whether taxa were present during their entire life or only early life stages, respectively. Samples were collected at eight different beaches during the wet, dry and intermediate or transitional season during the low spring tide, from 1999 to 2000, using a hyperbenthic sledge and epibenthic trawl. A total of 447 hyperbenthic and 30 epibenthic taxa were collected, most of which were crustaceans and fish, respectively (52 and 60% of taxa). The mysid, Metamysidopsis sp., was the most abundant member of the hyperbenthos (average ± SD: 14,425 ± 40,039 ind. 100 m- 2, present in 92% of samples collected), and the swimming blue crab, Areneus mexicanus, was the most encountered species among the epibenthos (1 ± 1 ind. 100 m- 2, 97% of samples collected). All faunal groups varied among beaches, while the holo-hyperbenthos and less strongly the epibenthos varied among seasons. Variability in the three faunas among beaches, distance from the continental slope and the Guayas estuarine system, and beach water physical characteristics were all strongly correlated suggesting adjacent habitats can influence surf zone biological communities and water physical characteristics. Seasonal effects were related to changes in water physical characteristics among seasons potentially reflecting changes in oceanic currents. These results suggest that, similarly to other beaches around the world, Ecuadorian

  13. Ichthyoplankton in a southern african surf zone: Nursery area for the postlarvae of estuarine associated fish species?

    Science.gov (United States)

    Whitfield, A. K.

    1989-12-01

    The surf zone ichthyoplankton of Swartvlei Bay was studied between February 1986 and June 1987, with particular emphasis on its potential role as a nursery area for estuarine associated marine fish species. Larvae and/or postlarvae of 16 families were identified from the surf zone, with the Gobiidae, Soleidae, Sparidae and Mugilidae comprising 85·7% of all teleosts sampled. The postlarvae of several taxa (including the six most common species), which utilize the Swartvlei estuary as a juvenile nursery area, were abundant in the surf zone. Conversely, species which are common in nearshore marine waters as juveniles and adults, but seldom enter estuaries, totalled less than 8% of the surf zone ichthyoplankton assemblage. Larval and postlarval densities peaked during summer when water temperatures exceeded 19°C and the estuary mouth was open. Concentrations of ichthyoplankton were highest at those sampling stations closest to the estuary mouth during the summer period. Diel changes in total catches revealed no significant difference between day and night densities; but of the four major taxa, the Mugilidae and Sparidae tended to be more abundant during the day, the Gobiidae at night and the Soleidae showed no distinct pattern. Results from a 24 h sampling session indicated that tidal phase may also be important in governing ichthyoplankton abundance in the surf zone.

  14. Scaled photographs of surf over the full range of breaker sizes on the north shore of Oahu and Jaws, Maui, Hawaiian Islands, January 1998 - May 2004 (NODC Accession 0001753)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Digital surf photographs were scaled using surfers as height benchmarks to estimate the size of the breakers. Historical databases for surf height in Hawaii are...

  15. Prediction and assimilation of surf-zone processes using a Bayesian network: Part I: Forward models

    Science.gov (United States)

    Plant, Nathaniel G.; Holland, K. Todd

    2011-01-01

    Prediction of coastal processes, including waves, currents, and sediment transport, can be obtained from a variety of detailed geophysical-process models with many simulations showing significant skill. This capability supports a wide range of research and applied efforts that can benefit from accurate numerical predictions. However, the predictions are only as accurate as the data used to drive the models and, given the large temporal and spatial variability of the surf zone, inaccuracies in data are unavoidable such that useful predictions require corresponding estimates of uncertainty. We demonstrate how a Bayesian-network model can be used to provide accurate predictions of wave-height evolution in the surf zone given very sparse and/or inaccurate boundary-condition data. The approach is based on a formal treatment of a data-assimilation problem that takes advantage of significant reduction of the dimensionality of the model system. We demonstrate that predictions of a detailed geophysical model of the wave evolution are reproduced accurately using a Bayesian approach. In this surf-zone application, forward prediction skill was 83%, and uncertainties in the model inputs were accurately transferred to uncertainty in output variables. We also demonstrate that if modeling uncertainties were not conveyed to the Bayesian network (i.e., perfect data or model were assumed), then overly optimistic prediction uncertainties were computed. More consistent predictions and uncertainties were obtained by including model-parameter errors as a source of input uncertainty. Improved predictions (skill of 90%) were achieved because the Bayesian network simultaneously estimated optimal parameters while predicting wave heights.

  16. Spatial and temporal variability in surf zone fish assemblages on the coast of northern New Jersey

    Science.gov (United States)

    Wilber, D. H.; Clarke, D. G.; Burlas, M. H.; Ruben, H.; Will, R. J.

    2003-02-01

    The surf zone fish community along 15 km of northern New Jersey shoreline was sampled every 2 weeks by beach seine in the late summers and early falls of 1995-1999 in conjunction with monitoring of a beach nourishment project. Fifty-seven species representing 30 families were collected during the course of the study. Over 90% of each sampling period's catch was composed of five taxa or less. These taxa included Atlantic and rough silversides, Menidia menidia and Membras martinica, bluefish, Pomatomus saltatrix, and bay and striped anchovies, Anchoa mitchilli and Anchoa hepsetus, with the relative contributions of these taxa varying among years. Both bluefish and anchovy abundances varied by an order of magnitude among years. Size-frequency distributions indicate summer-spawned bluefish recruit to the surf zone habitat as two cohorts in August and October, respectively. Fish abundance and richness were greater at substations closest to rock groins. Taxonomic richness declined along with decreasing water temperature in the fall, but was not correlated with turbidity or tide stage (measured as minutes before or after low tide). The extensive sampling effort undertaken in this study, 2190 seine hauls that captured 295 868 fish, was examined in relation to the number and relative proportions of taxa collected. Species accumulation curves and percent similarity calculations were used to investigate the adequacy of a reduced sampling protocol in characterizing the taxonomic composition of the surf zone fish community. Calculations from eight complete sampling periods (84 seine hauls each) indicate that a reduction in sampling effort by one-half would have yielded on average 75% of the total number of species captured with approximately 85% similarity in relative species composition.

  17. Assessment of surf zone environmental variables in a southwestern Atlantic sandy beach (Monte Hermoso, Argentina).

    Science.gov (United States)

    Menéndez, M Clara; Fernández Severini, Melisa D; Buzzi, Natalia S; Piccolo, M Cintia; Perillo, Gerardo M E

    2016-08-01

    The aim of this study was to investigate the temporal dynamics (monthly/tidal) of water temperature, salinity, chlorophyll-a (chlo-a), suspended particulate matter (SPM), particulate organic carbon (POC), and dissolved nutrients in the surf zone of Monte Hermoso sandy beach, Argentina. We also aimed to understand the underlying mechanisms responsible for the observed variability. Sampling was carried out approximately monthly (September 2009-November 2010), and all samples were collected in a fixed station during high and low tide. Water temperature showed a clear seasonal variability (July: 9 °C-December: 26.5 °C) and a thermal amplitude of 17.5 °C. Salinity ranged from 33 to 37, without a pronounced seasonality. SPM (10-223 mg L(-1)) and POC concentrations (399-6445 mg C m(-3)) were high in surf zone waters. Chlo-a (0.05-9.16 μg L(-1)) was low and did not evidence the occurrence of surf diatom accumulations. Dissolved nutrient concentration was quite fluctuating. None of the variables seemed to be affected by tidal stage. The results showed how fluctuating the physico-chemical and biological variables can be in this particular system. The observed variability can be related with local beach conditions but also with regional processes. The study area is highly influenced by a neighbor estuary and as a consequence, could be vulnerable to their seasonal and inter-annual dynamics. All of these characteristics must be considered for further studies and planning of the uses of natural resources and should be taken into account in any environmental monitoring program conducted in a similar beach system.

  18. Simultaneous Observations of Beach and Surf-Zone Topography from a sUAS

    Science.gov (United States)

    Slocum, R. K.; Brodie, K. L.; Spore, N.

    2016-02-01

    Beaches and surf-zones can vary rapidly in time and space, necessitating frequent, spatially extensive observations for up-to-date knowledge on their current condition. Traditional surveying methods are expensive, can be dangerous in large wave conditions, and can lack sufficient spatial density. Existing remote sensing technologies have focused on both active sensing (airborne lidar, X-band radar) or passive sensing (electro-optical or infrared imagery) to either directly measure elevations of the beach and seafloor or exploit the optical signal of refracting and breaking waves in the surf-zone. These methods, however, can be prohibitively expensive for widespread, high temporal frequency use, or lack the spatial coverage required to quantify a large stretch of beach. UAS offer an affordable and accessible alternative, but existing COTS UAS sensor suites are not optimized for generation of bathymetry and topography at the same time. Here, we present a new approach using an inexpensive, custom multi-camera sensor designed with a wide field of view for integration on either a fixed wing of multirotor UAS platform. We introduce a processing methodology and workflow to generate a topographic pointcloud and rectified imagery of the water surface using structure from motion algorithms. The topographic pointcloud data is processed to generate a DSM of the beach and extract morphologic parameters (beach slope, dune toe, etc). Rectified imagery of the water surface is used to quantify sandbar location as well as perform a celerity based bathymetric inversion. Accuracy of this methodology is calculated by comparing processed data to lidar pointclouds, as well as photo identifiable targets on the beach and jetted into the surf zone. Funded by the USACE Military Engineering POD:A&U Program and Coastal Field Data Collection Program.

  19. Associations between Functional Movement Screen scores and performance variables in surf athletes.

    Science.gov (United States)

    Ferreira da Silva, Bruno A; Clemente, Filipe M; Lourenço Martins, Fernando M

    2017-02-22

    Functional Movement Screen (FMS) have been used to assess the movement patterns in daily sports practice. Some associations between FMS scores and physical variables have been found in some sports. Nevertheless, no study was conducted in surf. Eighteen surf athletes (11 male) participated in the study (18.3 ± 6.3 y; 60.0 ± 9.6 kg; 168.6 ± 8.1 cm). All participants completed anthropometrics, Knee to Wall test, Functional Movement Screen, Isometric Knee Extension, Handgrip, Squat and Countermovement Jump. Based on that, this study investigated: 1) the variance of FMS scores between gender; 2) the association between FMS scores and physical variables of strength of upper and lower limbs, power of lower limbs and anthropometric variables; and 3) which FMS scores best explain the physical performance variables. The analysis of comparison between gender of each item of FMS showed significant statistical differences only in Trunk Stability Push-Up (p = 0.01, ES=0.141). Kendall's Tau b correlation test between FMS scores and physical variables, revealed significant associations. After performed the stepwise multiple linear regression FMS Deep Squat and Trunk Stability Push-Up explains 57% of Knee to Wall test - right side and the model is statistically significant (F(2. 15) = 13.097; p-value = 0.001). In Squat Jump (height) the results show that FMS Trunk Stability Push-Up explains 50.3% of this dimension and the model is statistically significant (F(1. 16) = 18.182; p-value = 0.001). FMS individual scores seems to better explain physical variables than total score. Only Trunk Stability Push-Up test seems to be a reliable indicator to predict physical performance in surf athletes.

  20. Modification of the Undertow and Turbulence by Submerged Vegetation in a Laboratory Surf Zone

    Science.gov (United States)

    Mandel, T.; Suckale, J.; Marras, S.; Maldonado, S.; Koseff, J. R.

    2016-12-01

    Breaking waves in the surf zone are a dominant factor shaping the evolution of our coastlines. The turbulence generated by wave breaking causes sediment resuspension, while wave runup, rundown, and the undertow transport this sediment along and across the shore (Longo et al., 2002). Coastal hazard models must now address the added complications of climate change, including sea level rise, stronger storm events, and ecosystem degradation (Arkema et al., 2013). A robust theoretical understanding of surf zone dynamics is therefore imperative to considering the magnitude and implications of these potential changes. However, little work has been done to extend our current theoretical understanding to realistic beach faces, with aquatic vegetation, reefs, and other roughness elements that might mitigate scour and sedimentation. Clarifying these relationships will help scientists and policy-makers decide where to focus ecosystem restoration and preservation efforts, in order to maximize their protective benefits to infrastructure and economic activity on the coast. In order to evaluate the role of vegetation in coastal protection, we conducted a series of experiments in an idealized laboratory surf zone. We examine the impact of submerged model vegetation on the undertow profile, wave orbital velocities, turbulent kinetic energy, and wave-induced stresses, and compare these results to theoretical formulations that model these quantities. We find that vegetation reduces the wave energy available to be converted to turbulent kinetic energy during breaking, indicating a mechanism to mitigate suspension of sediment. Vegetation also reduces the magnitude of the undertow, likely reducing transport of sediment offshore. These results suggest that vegetation provides significant protective benefits for coastal communities at risk from erosion beyond its well-characterized ability to attenuate wave height, and motivate further work to incorporate these effects into models of near

  1. QSAR study and VolSurf characterization of anti-HIV quinolone library

    Science.gov (United States)

    Filipponi, Enrica; Cruciani, Gabriele; Tabarrini, Oriana; Cecchetti, Violetta; Fravolini, Arnaldo

    2001-03-01

    Antiviral quinolones are promising compounds in the search for new therapeutically effective agents for the treatment of AIDS. To rationalize the SAR for this new interesting class of anti-HIV derivatives, we performed a 3D-QSAR study on a library of 101 6-fluoro and 6-desfluoroquinolones, taken either from the literature or synthesized by us. The chemometric procedure involved a fully semiempirical minimization of the molecular structures by the AMSOL program, which takes into account the solvatation effect, and their 3D characterization by the VolSurf/GRID program. The QSAR analysis, based on PCA and PLS methods, shows the key structural features responsible for the antiviral activity.

  2. Internal waves and surf zone water quality at Huntington Beach, California

    Science.gov (United States)

    Wong, H.; Santoro, A.; Nidzieko, N. J.; Hench, J. L.; Boehm, A. B.

    2011-12-01

    This study characterized diurnal, semi-diurnal, and high-frequency internal wave field at Huntington Beach, California, USA and the connection between internal waves and surf zone water quality. An array of oceanographic moorings was deployed in the summer of 2005 and 2006 at 10-20 meter depths offshore of the beach to observe internal waves and cross-shore exchange. Concurrently, surf zone water quality was assessed twice daily at an adjacent station (Huntington State Beach) with measurements of phosphate, dissolved inorganic nitrogen, silicate, chlorophyll a, fecal indicator bacteria, and the human-specific fecal DNA marker in Bacteroidales. Spectral analysis of water temperature shows well-defined spectral peaks at diurnal and semi-diurnal frequencies. Complex Empirical Orthogonal Function analysis of observed currents reveals that the baroclinic component (summation of second to fifth principal components) accounted for 30% of the total variance in the currents in both years, indicating the importance of density-driven flow during the summer when the water column was stratified. The major axis of the first principal component was oriented alongshore, whereas that of the second and third principal components made an angle of 25 to 55 degree with the cross-shore direction. Arrival of cold subthermocline water in the very near shore (within 1 km of the surf zone) was characterized by strong onshore flow near the bottom of the water column. The near bottom, baroclinic, cross-shore current was significantly lag-correlated with the near bottom temperature data along a cross-shore transect towards shore, indicative of shoreward transport of cold subthermocline water. Wavelet analysis of temperature data showed that non-stationary temperature fluctuations were correlated with buoyancy frequency and the near bottom cross-shore baroclinic current. During periods of large temperature fluctuations, the majority of the variance was within the semi-diurnal band; however, the

  3. Comparison Between Surf and Multi-Shock Forest Fire High Explosive Burn Models

    Energy Technology Data Exchange (ETDEWEB)

    Greenfield, Nicholas Alexander [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-07-18

    PAGOSA1 has several different burn models used to model high explosive detonation. Two of these, Multi-Shock Forest Fire and Surf, are capable of modeling shock initiation. Accurately calculating shock initiation of a high explosive is important because it is a mechanism for detonation in many accident scenarios (i.e. fragment impact). Comparing the models to pop-plot data give confidence that the models are accurately calculating detonation or lack thereof. To compare the performance of these models, pop-plots2 were created from simulations where one two cm block of PBX 9502 collides with another block of PBX 9502.

  4. Mimicking a SURF1 allele reveals uncoupling of cytochrome c oxidase assembly from translational regulation in yeast.

    Science.gov (United States)

    Reinhold, Robert; Bareth, Bettina; Balleininger, Martina; Wissel, Mirjam; Rehling, Peter; Mick, David U

    2011-06-15

    Defects in mitochondrial energy metabolism lead to severe human disorders, mainly affecting tissues especially dependent on oxidative phosphorylation, such as muscle and brain. Leigh Syndrome describes a severe encephalomyopathy in infancy, frequently caused by mutations in SURF1. SURF1, termed Shy1 in Saccharomyces cerevisiae, is a conserved assembly factor for the terminal enzyme of the respiratory chain, cytochrome c oxidase. Although the molecular function of SURF1/Shy1 is still enigmatic, loss of function leads to cytochrome c oxidase deficiency and reduced expression of the central subunit Cox1 in yeast. Here, we provide insights into the molecular mechanisms leading to disease through missense mutations in codons of the most conserved amino acids in SURF1. Mutations affecting G(124) do not compromise import of the SURF1 precursor protein but lead to fast turnover of the mature protein within the mitochondria. Interestingly, an Y(274)D exchange neither affects stability nor localization of the protein. Instead, SURF1(Y274D) accumulates in a 200 kDa cytochrome c oxidase assembly intermediate. Using yeast as a model, we demonstrate that the corresponding Shy1(Y344D) is able to overcome the stage where cytochrome c oxidase assembly links to the feedback regulation of mitochondrial Cox1 expression. However, Shy1(Y344D) impairs the assembly at later steps, most apparent at low temperature and exhibits a dominant-negative phenotype upon overexpression. Thus, exchanging the conserved tyrosine (Y(344)) with aspartate in yeast uncouples translational regulation of Cox1 from cytochrome c oxidase assembly and provides evidence for the dual functionality of Shy1.

  5. Black Scoter - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  6. Active depinning of bacterial droplets: the collective surfing of Bacillus subtilis

    Science.gov (United States)

    Hennes, Marc; Tailleur, Julien; Daerr, Adrian

    2016-11-01

    How systems are endowed with migration capacity is a fascinating question with implications ranging from the design of novel active systems to the control of microbial populations. Bacteria, which can be found in a variety of environments, have developed among the richest set of locomotion mechanisms both at the microscopic and collective levels. Here, we uncover experimentally a new mode of collective bacterial motility in humid environment through the depinning of bacterial droplets. While capillary forces are notoriously enormous at the bacterial scale, even capable of pinning water droplets of millimetric size on inclined surfaces, we show that bacteria are able to harness a variety of mechanisms to unpin contact lines, hence inducing a collective sliding of the colony. Contrary to flagella-dependent migration modes like swarming we show that this much faster colony surfing still occurs in mutant strains of Bacillus subtilis lacking flagella. The diversity of mechanisms involved in the active unpinning seen in our experiments suggests that collective surfing should be a generic mode of migration of microorganisms in humid environments. Bacttern Grant.

  7. Wave Transformation in a Multi-Bar Surf Zone: Case Study of Lubiatowo (Poland)

    Science.gov (United States)

    Lan, Yuan-Jyh; Hsu, Tai-Wen; Ostrowski, Rafał; Szmytkiewicz, Marek

    2016-06-01

    The paper presents results of field and theoretical investigations of wave transformation in the surf zone near the IBW PAN Coastal Research Station in Lubiatowo (Poland, the south Baltic Sea). The study site displays multi-bar cross-shore profiles that intensively dissipate wave energy, mostly induced by breaking. The main field data comprise wave heights and cross-shore bathymetric profiles.Wave transformation is modelled theoretically by two approaches, namely the IBW PAN phase-averaged wave transformation model and the approach based on the hydraulic jump model, developed by Hsu & Lai (2009) for hydrological situations encountered under the actual conditions of two field campaigns - in 1987 and 1996. Discrepancies between the measured data and the model results are discussed. In general, the model results are in good agreement with the in-situ observations. The comparison of the field data with the computational results concerns a part of the surf zone between about 5 m water depth and the first nearshore stable bar, where the depth amounts to ca. 1.2 m.

  8. Verification Test of the SURF and SURFplus Models in xRage: Part II

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-20

    The previous study used an underdriven detonation wave (steady ZND reaction zone profile followed by a scale invariant rarefaction wave) for PBX 9502 as a validation test of the implementation of the SURF and SURFplus models in the xRage code. Even with a fairly fine uniform mesh (12,800 cells for 100mm) the detonation wave profile had limited resolution due to the thin reaction zone width (0.18mm) for the fast SURF burn rate. Here we study the effect of finer resolution by comparing results of simulations with cell sizes of 8, 2 and 1 μm, which corresponds to 25, 100 and 200 points within the reaction zone. With finer resolution the lead shock pressure is closer to the von Neumann spike pressure, and there is less noise in the rarefaction wave due to fluctuations within the reaction zone. As a result the average error decreases. The pointwise error is still dominated by the smearing the pressure kink in the vicinity of the sonic point which occurs at the end of the reaction zone.

  9. Comparison of impact forces, accelerations and ankle range of motion in surfing-related landing tasks.

    Science.gov (United States)

    Lundgren, Lina E; Tran, Tai T; Nimphius, Sophia; Raymond, Ellen; Secomb, Josh L; Farley, Oliver R L; Newton, Robert U; Sheppard, Jeremy M

    2016-01-01

    This study aimed to describe the impact forces, accelerations and ankle range of motion in five different landing tasks that are used in training and testing for competitive surfing athletes, to assist coaches in the prescription of landing task progression and monitoring training load. Eleven competitive surfing athletes aged 24 ± 7 years participated, and inertial motion sensors were fixed to the anterior aspect of the feet, mid-tibial shafts, sacrum and eighth thoracic vertebrae on these athletes. Three tasks were performed landing on force plates and two tasks in a modified gymnastics set-up used for land-based aerial training. Peak landing force, resultant peak acceleration and front and rear side ankle dorsiflexion ranges of motion during landing were determined. The peak acceleration was approximately 50% higher when performing aerial training using a mini-trampoline and landing on a soft-density foam board, compared to a similar landing off a 50 cm box. Furthermore, the ankle ranges of motion during the gymnastic type landings were significantly lower than the other landing types (P ≤ 0.05 and P ≤ 0.001), for front and rear sides, respectively. Conclusively, increased task complexity and specificity of the sport increased the tibial peak acceleration, indicating greater training load.

  10. Mutations of SURF-1 in Leigh disease associated with cytochrome c oxidase deficiency.

    Science.gov (United States)

    Tiranti, V; Hoertnagel, K; Carrozzo, R; Galimberti, C; Munaro, M; Granatiero, M; Zelante, L; Gasparini, P; Marzella, R; Rocchi, M; Bayona-Bafaluy, M P; Enriquez, J A; Uziel, G; Bertini, E; Dionisi-Vici, C; Franco, B; Meitinger, T; Zeviani, M

    1998-12-01

    Leigh disease associated with cytochrome c oxidase deficiency (LD[COX-]) is one of the most common disorders of the mitochondrial respiratory chain, in infancy and childhood. No mutations in any of the genes encoding the COX-protein subunits have been identified in LD(COX-) patients. Using complementation assays based on the fusion of LD(COX-) cell lines with several rodent/human rho0 hybrids, we demonstrated that the COX phenotype was rescued by the presence of a normal human chromosome 9. Linkage analysis restricted the disease locus to the subtelomeric region of chromosome 9q, within the 7-cM interval between markers D9S1847 and D9S1826. Candidate genes within this region include SURF-1, the yeast homologue (SHY-1) of which encodes a mitochondrial protein necessary for the maintenance of COX activity and respiration. Sequence analysis of SURF-1 revealed mutations in numerous DNA samples from LD(COX-) patients, indicating that this gene is responsible for the major complementation group in this important mitochondrial disorder.

  11. New approach for measuring 3D space by using Advanced SURF Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Youm, Minkyo; Min, Byungil; Suh, Kyungsuk [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Backgeun [Sungkyunkwan Univ., Suwon (Korea, Republic of)

    2013-05-15

    The nuclear disasters compared to natural disaster create a more extreme condition for analyzing and evaluating. In this paper, measuring 3D space and modeling was studied by simple pictures in case of small sand dune. The suggested method can be used for the acquisition of spatial information by robot at the disaster area. As a result, these data are helpful for identify the damaged part, degree of damage and determination of recovery sequences. In this study we are improving computer vision algorithm for 3-D geo spatial information measurement. And confirm by test. First, we can get noticeable improvement of 3-D geo spatial information result by SURF algorithm and photogrammetry surveying. Second, we can confirm not only decrease algorithm running time, but also increase matching points through epi polar line filtering. From the study, we are extracting 3-D model by open source algorithm and delete miss match point by filtering method. However on characteristic of SURF algorithm, it can't find match point if structure don't have strong feature. So we will need more study about find feature point if structure don't have strong feature.

  12. Preventing Shoulder-Surfing Attack with the Concept of Concealing the Password Objects’ Information

    Directory of Open Access Journals (Sweden)

    Peng Foong Ho

    2014-01-01

    Full Text Available Traditionally, picture-based password systems employ password objects (pictures/icons/symbols as input during an authentication session, thus making them vulnerable to “shoulder-surfing” attack because the visual interface by function is easily observed by others. Recent software-based approaches attempt to minimize this threat by requiring users to enter their passwords indirectly by performing certain mental tasks to derive the indirect password, thus concealing the user’s actual password. However, weaknesses in the positioning of distracter and password objects introduce usability and security issues. In this paper, a new method, which conceals information about the password objects as much as possible, is proposed. Besides concealing the password objects and the number of password objects, the proposed method allows both password and distracter objects to be used as the challenge set’s input. The correctly entered password appears to be random and can only be derived with the knowledge of the full set of password objects. Therefore, it would be difficult for a shoulder-surfing adversary to identify the user’s actual password. Simulation results indicate that the correct input object and its location are random for each challenge set, thus preventing frequency of occurrence analysis attack. User study results show that the proposed method is able to prevent shoulder-surfing attack.

  13. Verification test of the SURF and SURFplus models in xRage

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-18

    As a verification test of the SURF and SURFplus models in the xRage code we use a propagating underdriven detonation wave in 1-D. This is about the only test cases for which an accurate solution can be determined based on the theoretical structure of the solution. The solution consists of a steady ZND reaction zone profile joined with a scale invariant rarefaction or Taylor wave and followed by a constant state. The end of the reaction profile and the head of the rarefaction coincide with the sonic CJ state of the detonation wave. The constant state is required to match a rigid wall boundary condition. For a test case, we use PBX 9502 with the same EOS and burn rate as previously used to test the shock detector algorithm utilized by the SURF model. The detonation wave is propagated for 10 μs (slightly under 80mm). As expected, the pointwise errors are largest in the neighborhood of discontinuities; pressure discontinuity at the lead shock front and pressure derivative discontinuities at the head and tail of the rarefaction. As a quantitative measure of the overall accuracy, the L2 norm of the difference of the numerical pressure and the exact solution is used. Results are presented for simulations using both a uniform grid and an adaptive grid that refines the reaction zone.

  14. MOD_FreeSurf2D: a Surface Fluid Flow Simulation Model for Rivers, Streams, and Shallow Estuaries

    Science.gov (United States)

    Martin, N.; Gorelick, S. M.

    2003-12-01

    The MOD_FreeSurf2D, Modular Free Surface Flow in Two-Dimensions, computer model simulates free surface fluid flow in streams, rivers, and shallow estuaries under the assumptions of a well-mixed water column, a small water depth to width ratio, and a hydrostatic pressure distribution. The dependent variables in the model are free surface elevation, which provides total water depth, and fluid velocity. Primary advantages of MOD_FreeSurf2D relative to other two-dimensional models are a stable and computationally efficient numerical representation and a transparent representation of wetting and drying of the simulation domain. MOD_FreeSurf2D approximates the depth-averaged, shallow water equations with a finite volume, semi-implicit, semi-Lagrangian numerical representation similar to the TRIM method (Casulli, 1990; Casulli and Cheng, 1992; Casulli, 1999). The semi-implicit, semi-Lagrangian approach is computationally efficient because time steps can exceed the Courant-Friedrich-Lewy (CFL) stability criterion without significant accuracy degradation (Robert, 1982; Casulli, 1990). The rectangular, Arakawa C-grid, finite-volume layout allows flooding and drying in response to changing flow conditions without prior channel specification or closed boundary specification. Open boundary conditions available in MOD_FreeSurf2D are specified flux, specified total water depth, specified velocity, radiation free surface, and radiation velocity. MOD_FreeSurf2D requires initial topography, undisturbed water depth, and Manning's roughness coefficient. MOD_FreeSurf2D simulated results are shown to converge to the semi-empirical solution for a simple straight channel case. Two applications demonstrate the accuracy of MOD_FreeSurf2D. The first application is the evolution of water depth in the dambreak-style flume experiment of Bellos et al. (1992). In this case, MOD_FreeSurf2D accurately simulates the changing water depth in the flume during the experiment and models the wetting of

  15. Norman-based Isolated Data Systems allows users to surf the Internet with no traceable IP address

    CERN Multimedia

    2004-01-01

    "Patented by Norman-based Isolated Data Systems, John Doe is an anonymous proxy server that allows users to surf the Internet exactly as before, with one exception - they are identifiable only as John Doe, with no traceable IP address, which means no tracking, no identification and no profile building" ( 1/2 page)

  16. Epidemlology of exercise-related transient abdominal pain at the Sydney City to Surf community run.

    Science.gov (United States)

    Morton, D P; Richards, D; Callister, R

    2005-06-01

    A questionnaire was administered to 848 participants (76% runners, 24% walkers) at the conclusion of the 14 km City to Surf community run in order to investigate their experience of exercise-related transient abdominal pain (ETAP). Twenty-seven percent of respondents reported experiencing ETAP during the event, with the condition reported more frequently (pnutritional content of the pre-event meal did not influence the experience of ETAP. Sufferers of ETAP were more likely to experience nausea (r = 0.12, p< 0.01) and report shoulder tip pain (r= 0.14, p< 0.01). The results indicate that ETAP is a commonly experienced problem and provide insights into the cause of the complaint.

  17. A VOF-based numerical model for breaking waves in surf zone

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper introduces a numerical model for studying the evolution of a periodic wave train,shoaling, and breaking in surf zone. The model can solve the Reynolds averaged Navier-Stokes (RANS) equations for a mean flow, and the k-ε equations for turbulence kinetic energy k and turbulence dissipation rate ε. To track a free surface, the volume of fluid (VOF) function, satisfying the advection equation was introduced. In the numerical treatment, third-order upwind difference scheme was applied to the convection terms of the RANS equations in order to reduce the effect of numerical viscosity. The shoaling and breaking processes of a periodic wave train on gently sloping beaches were modeled. The computed wave heights of a sloping beach and the distribution of breaking wave pressure on a vertical wall were compared with laboratory data.

  18. 3D reconstruction of a human heart fascicle using SurfDriver

    Science.gov (United States)

    Rader, Robert J.; Phillips, Steven J.; LaFollette, Paul S., Jr.

    2000-06-01

    The Temple University Medical School has a sequence of over 400 serial sections of adult normal ventricular human heart tissue, cut at 25 micrometer thickness. We used a Zeiss Ultraphot with a 4x planapo objective and a Pixera digital camera to make a series of 45 sequential montages to use in the 3D reconstruction of a fascicle (muscle bundle). We wrote custom software to merge 4 smaller image fields from each section into one composite image. We used SurfDriver software, developed by Scott Lozanoff of the University of Hawaii and David Moody of the University of Alberta, for registration, object boundary identification, and 3D surface reconstruction. We used an Epson Stylus Color 900 printer to get photo-quality prints. We describe the challenge and our solution to the following problems: image acquisition and digitization, image merge, alignment and registration, boundary identification, 3D surface reconstruction, 3D visualization and orientation, snapshot, and photo-quality prints.

  19. Diarrhetic shellfish poisoning toxin esters in Danish blue mussels and surf clams

    DEFF Research Database (Denmark)

    Jørgensen, Kevin; Scanlon, Sine Hedegaard; Jensen, L.B.

    2005-01-01

    Until recently, little focus was given to the presence of diarrhetic shellfish poisoning ( DSP) toxin esters in seafood products. However, during the last few years, the occurrence of a high percentage of esters of the total amount of DSP toxins present in some seafood products has been observed....... Samples of Danish surf clams ( Spisola spp.) and blue mussels ( Mytilus edulis) from 1999 - 2004 were analysed by liquid chromatography coupled with tandem mass spectrometry ( LC/ MS/ MS) for the presence of DSP toxin esters. The samples contained only okadaic acid and esters of okadaic acid. The level...... of okadaic acid esters of the total okadaic acid equivalents ranged from 21 to 86%, mean 59%. The probability of a high percentage of okadaic acid esters seems to increase with higher amounts of total okadaic acid equivalents in the bivalves. The large prevalence of DSP toxin esters are of particular...

  20. Physical linkages between an offshore canyon and surf zone morphologic change

    Science.gov (United States)

    Hansen, Jeff E.; Raubenheimer, Britt; Elgar, Steve; List, Jeffrey H.; Lippmann, Thomas C.

    2017-04-01

    The causes of surf zone morphologic changes observed along a sandy beach onshore of a submarine canyon were investigated using field observations and a numerical model (Delft3D/SWAN). Numerically simulated morphologic changes using four different sediment transport formulae reproduce the temporal and spatial patterns of net cross-shore integrated (between 0 and 6.5 m water depths) accretion and erosion observed in a ˜300 m alongshore region, a few hundred meters from the canyon head. The observations and simulations indicate that the accretion or erosion results from converging or diverging alongshore currents driven primarily by breaking waves and alongshore pressure gradients. The location of convergence or divergence depends on the direction of the offshore waves that refract over the canyon, suggesting that bathymetric features on the inner shelf can have first-order effects on short-term nearshore morphologic change.

  1. Phase speed of electrostatic waves: The critical parameter for efficient electron surfing acceleration

    CERN Document Server

    Dieckmann, M E; Parviainen, M; Shukla, P K; Sircombe, N J

    2006-01-01

    Particle acceleration by means of non-linear plasma wave interactions is of great topical interest. Accordingly, in this paper we focus on the electron surfing process. Self-consistent kinetic simulations, using both relativistic Vlasov and PIC (Particle In Cell) approaches, show here that electrons can be accelerated to highly relativistic energies (up to 100 m_e c^2) if the phase speed of the electrostatic wave is mildly relativistic (0.6c to 0.9c for the magnetic field strengths considered). The acceleration is strong because of relativistic stabilisation of the nonlinearly saturated electrostatic wave, seen in both relativistic Vlasov and PIC simulations. An inverse power law momentum distribution can arise for the most strongly accelerated electrons. These results are of relevance to observed rapid changes in the radio synchrotron emission intensities from microquasars, gamma ray bursts and other astrophysical objects that require rapid acceleration mechanisms for electrons.

  2. Phase speed of electrostatic waves: the critical parameter for efficient electron surfing acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Dieckmann, M E [Institut fuer Theoretische Physik IV, Fakultaet fuer Physik und Astronomie, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Sircombe, N J [Institut fuer Theoretische Physik IV, Fakultaet fuer Physik und Astronomie, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Parviainen, M [Institut fuer Theoretische Physik IV, Fakultaet fuer Physik und Astronomie, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Shukla, P K [Institut fuer Theoretische Physik IV, Fakultaet fuer Physik und Astronomie, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Dendy, R O [UKAEA Culham Division, Culham Science Centre, Abingdon, Oxfordshire, OX14 3DB (United Kingdom); Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom)

    2006-04-15

    Particle acceleration by means of nonlinear plasma wave interactions is of great topical interest. Accordingly, in this paper we focus on the electron surfing process. Self-consistent kinetic simulations, using both relativistic Vlasov and particle-in-cell (PIC) approaches, show here that electrons can be accelerated to highly relativistic energies (up to 100m{sub e}c{sup 2}) if the phase speed of the electrostatic wave is mildly relativistic (0.6c to 0.9c for the magnetic field strengths considered). The acceleration is strong because of relativistic stabilization of the nonlinearly saturated electrostatic wave, seen in both relativistic Vlasov and PIC simulations. An inverse power law momentum distribution can arise for the most strongly accelerated electrons. These results are of relevance to observed rapid changes in the radio synchrotron emission intensities from microquasars, gamma ray bursts and other astrophysical objects that require rapid acceleration mechanisms for electrons.

  3. Numerical modelling of wind effects on breaking waves in the surf zone

    Science.gov (United States)

    Xie, Zhihua

    2017-10-01

    Wind effects on periodic breaking waves in the surf zone have been investigated in this study using a two-phase flow model. The model solves the Reynolds-averaged Navier-Stokes equations with the k - 𝜖 turbulence model simultaneously for the flows both in the air and water. Both spilling and plunging breakers over a 1:35 sloping beach have been studied under the influence of wind, with a focus during wave breaking. Detailed information of the distribution of wave amplitudes and mean water level, wave-height-to-water-depth ratio, the water surface profiles, velocity, vorticity, and turbulence fields have been presented and discussed. The inclusion of wind alters the air flow structure above water waves, increases the generation of vorticity, and affects the wave shoaling, breaking, overturning, and splash-up processes. Wind increases the water particle velocities and causes water waves to break earlier and seaward, which agrees with the previous experiment.

  4. Chemolithotrophy in the continental deep subsurface: Sanford Underground Research Facility (SURF, USA

    Directory of Open Access Journals (Sweden)

    Magdalena Rose Osburn

    2014-11-01

    Full Text Available The deep subsurface is an enormous repository of microbial life. However, the metabolic capabilities of these microorganisms and the degree to which they are dependent on surface processes are largely unknown. Due to the logistical difficulty of sampling and inherent heterogeneity, the microbial populations of the terrestrial subsurface are poorly characterized. In an effort to better understand the biogeochemistry of deep terrestrial habitats, we evaluate the energetic yield of chemolithotrophic metabolisms and microbial diversity in the Sanford Underground Research Facility (SURF in the former Homestake Gold Mine, SD, USA. Geochemical data, energetic modeling, and DNA sequencing were combined with principle component analysis to describe this deep (down to 8100 ft below surface, terrestrial environment. SURF provides access into an iron-rich Paleoproterozoic metasedimentary deposit that contains deeply circulating groundwater. Geochemical analyses of subsurface fluids reveal enormous geochemical diversity ranging widely in salinity, oxidation state (ORP 330 to -328 mV, and concentrations of redox sensitive species (e.g., Fe2+ from near 0 to 6.2 mg/L and ΣS2- from 7 to 2778 μg/L. As a direct result of this compositional buffet, Gibbs energy calculations reveal an abundance of energy for microorganisms from the oxidation of sulfur, iron, nitrogen, methane, and manganese. Pyrotag DNA sequencing reveals diverse communities of chemolithoautotrophs, thermophiles, aerobic and anaerobic heterotrophs, and numerous uncultivated clades. Extrapolated across the mine footprint, these data suggest a complex spatial mosaic of subsurface primary productivity that is in good agreement with predicted energy yields. Notably, we report Gibbs energy normalized both per mole of reaction and per kg fluid (energy density and find the later to be more consistent with observed physiologies and environmental conditions. Further application of this approach will

  5. Numerical modeling of surf zone dynamics under weakly plunging breakers with SPH method

    Science.gov (United States)

    Makris, Christos V.; Memos, Constantine D.; Krestenitis, Yannis N.

    2016-02-01

    The wave breaking of weak plungers over a relatively mild slope is investigated in this paper. Numerical modeling aspects are studied, concerning the propagation and breaking of shore-normal, nonlinear and regular waves. The two-dimensional (2-D) kinematics and dynamics (fluctuating flow features and large 2-D eddies) of the wave-induced flow on a vertical cross-section over the entire surf zone are simulated with the use of Smoothed Particle Hydrodynamics (SPH). The academic 'open source' code SPHysics v.2 is employed and the viscosity treatment is based on a Sub-Particle Scale (SPS) approach, similarly to the Large Eddy Simulations (LES) concept. Thorough analysis of the turbulent flow scales determines the necessary refinement of the spatial resolution. The initial particle discretization reaches down to the demarcation point between integral turbulence length scales and Taylor micro-scales. A convolution-type integration method is implemented for the transformation of scattered Lagrangian particle data to Eulerian values at fixed gauges. A heuristic technique of ensemble-averaging is used for the discrimination of the fluctuating flow components from coherent structures and ordered wave motion. Comparisons between numerical and experimental data give encouraging results for several wave features. The wave-induced mean flows are simulated plausibly, and even the 'streaming' effect near the bed is reproduced. The recurring vorticity patterns are derived, and coherent 2-D structures inside the surf zone are identified. Fourier spectral analysis of velocities reveals isotropy of 2-D fluctuating dynamics up to rather high frequencies in shear intensified regions. The simulated Reynolds stresses follow patterns that define the characteristic mechanism of wave breaking for weak plungers. Persisting discrepancies at the incipient breaking region confirm the need for fine, massively 'parallel' 3-D SPS-SPH simulations.

  6. Mapping bathymetry in an active surf zone with the WorldView2 multispectral satellite

    Science.gov (United States)

    Trimble, S. M.; Houser, C.; Brander, R.; Chirico, P.

    2015-12-01

    Rip currents are strong, narrow seaward flows of water that originate in the surf zones of many global beaches. They are related to hundreds of international drownings each year, but exact numbers are difficult to calculate due to logistical difficulties in obtaining accurate incident reports. Annual average rip current fatalities are estimated to be ~100, 53 and 21 in the United States (US), Costa Rica, and Australia respectively. Current warning systems (e.g. National Weather Service) do not account for fine resolution nearshore bathymetry because it is difficult to capture. The method shown here could provide frequent, high resolution maps of nearshore bathymetry at a scale required for improved rip prediction and warning. This study demonstrates a method for mapping bathymetry in the surf zone (20m deep and less), specifically within rip channels, because rips form at topographically low spots in the bathymetry as a result of feedback amongst waves, substrate, and antecedent bathymetry. The methods employ the Digital Globe WorldView2 (WV2) multispectral satellite and field measurements of depth to generate maps of the changing bathymetry at two embayed, rip-prone beaches: Playa Cocles, Puerto Viejo de Talamanca, Costa Rica, and Bondi Beach, Sydney, Australia. WV2 has a 1.1 day pass-over rate with 1.84m ground pixel resolution of 8 bands, including 'yellow' (585-625 nm) and 'coastal blue' (400-450 nm). The data is used to classify bottom type and to map depth to the return in multiple bands. The methodology is tested at each site for algorithm consistency between dates, and again for applicability between sites.

  7. Object Recognition System in Remote Controlled Weapon Station using SIFT and SURF Methods

    Directory of Open Access Journals (Sweden)

    Midriem Mirdanies

    2013-12-01

    Full Text Available Object recognition system using computer vision that is implemented on Remote Controlled Weapon Station (RCWS is discussed. This system will make it easier to identify and shoot targeted object automatically. Algorithm was created to recognize real time multiple objects using two methods i.e. Scale Invariant Feature Transform (SIFT and Speeded Up Robust Features (SURF combined with K-Nearest Neighbors (KNN and Random Sample Consensus (RANSAC for verification. The algorithm is designed to improve object detection to be more robust and to minimize the processing time required. Objects are registered on the system consisting of the armored personnel carrier, tanks, bus, sedan, big foot, and police jeep. In addition, object selection can use mouse to shoot another object that has not been registered on the system. Kinect™ is used to capture RGB images and to find the coordinates x, y, and z of the object. The programming language used is C with visual studio IDE 2010 and opencv libraries. Object recognition program is divided into three parts: 1 reading image from kinect™ and simulation results, 2 object recognition process, and 3 transfer of the object data to the ballistic computer. Communication between programs is performed using shared memory. The detected object data is sent to the ballistic computer via Local Area Network (LAN using winsock for ballistic calculation, and then the motor control system moves the direction of the weapon model to the desired object. The experimental results show that the SIFT method is more suitable because more accurate and faster than SURF with the average processing time to detect one object is 430.2 ms, two object is 618.4 ms, three objects is 682.4 ms, and four objects is 756.2 ms. Object recognition program is able to recognize multi-objects and the data of the identified object can be processed by the ballistic computer in realtime.

  8. Chinese Sign Language Recognition Method Based on Depth Image Information and SURF-BoW%基于深度信息和SURF-BoW的中国手语识别算法

    Institute of Scientific and Technical Information of China (English)

    杨全; 彭进业

    2014-01-01

    为实现视频中手语的准确识别,提出一种基于深度图连续自适应均值漂移( DI_CamShift)和加速强健特征词包( SURF-BoW)的中国手语识别算法.该算法将Kinect作为手语视频采集设备,在获取彩色视频的同时得到其深度信息.算法首先计算深度图像中手语手势的主轴方向角和质心位置,通过调整搜索窗口对手势准确跟踪;然后使用基于深度积分图像的OTSU算法分割手势并提取其加速强健特征( SURF),进而构建SURF-BoW作为手语特征并使用SVM识别.通过实验验证该算法在单个手语字母上的最好识别率为99.37%,平均识别率为96.24%.%To realize the accurate recognition of sign language in the video, an algorithm based on depth image CamShift( DI_CamShift) and speeded up robust features-bag of words ( SURF-BoW) is proposed. Kinect is used as the sign language video capture device to obtain both of the color video and depth image information of sign language gestures. Firstly, spindle direction angle and mass center position of the depth images are calculated and the search window is adjusted to track gesture. Next, an OTSU algorithm based on depth integral image is used for gesture segmentation, and the SURF features are extracted. Finally, SURF-BoW is built as the feature of sign language and SVM is utilized for recognition. The best recognition rate of single manual alphabet reaches 99 . 37%, and the average recognition rate is up to 96 . 24%.

  9. A randomised crossover comparison of manikin ventilation through Soft Seal®, i‐gel™ and AuraOnce™ supraglottic airway devices by surf lifeguards

    National Research Council Canada - National Science Library

    Adelborg, K; Al‐Mashhadi, R. H; Nielsen, L. H; Dalgas, C; Mortensen, M. B; Løfgren, B

    2014-01-01

    Forty surf lifeguards attempted to ventilate a manikin through one out of three supraglottic airways inserted in random order: the Portex ® Soft Seal ® ; the Intersurgical ® i‐gel™; and the Ambu ® AuraOnce...

  10. Verification Test of the SURF and SURFplus Models in xRage: Part III Affect of Mesh Alignment

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-15

    The previous studies used an underdriven detonation wave in 1-dimension (steady ZND reaction zone profile followed by a scale-invariant rarefaction wave) for PBX 9502 as a verification test of the implementation of the SURF and SURFplus models in the xRage code. Since the SURF rate is a function of the lead shock pressure, the question arises as to the effect on accuracy of variations in the detected shock pressure due to the alignment of the shock front with the mesh. To study the effect of mesh alignment we simulate a cylindrically diverging detonation wave using a planar 2-D mesh. The leading issue is the magnitude of azimuthal asymmetries in the numerical solution. The 2-D test case does not have an exact analytic solution. To quantify the accuracy, the 2-D solution along rays through the origin are compared to a highly resolved 1-D simulation in cylindrical geometry.

  11. Temporal and spatial patterns for surf zone bacteria before and after disinfection of the orange county sanitation district effluent

    Science.gov (United States)

    Robertson, G.L.; Noble, M.A.; Xu, J. P.; Rosenfeld, L.K.; McGee, C.D.

    2005-01-01

    Data from pre- and post-disinfection fecal indicator bacteria (FIB) samples from final effluent, an offshore ocean outfall, and surf zone stations off Huntington Beach, CA were compared. Analysis of the results from these data sets confirmed that the ocean outfall was not the FIB source responsible for the postings and closures of local beaches that have occurred each summer since 1999. While FIB counts in the final effluent and offshore showed several order of magnitude reductions after disinfection, there were no significant reductions at the nearby surf zone stations. Additionally, the FIB spectral patterns suggest different sources. The dominant fortnightly cycle suggested that the source was related to the wetting and draining of the land from large spring tide tidal excursions.

  12. Association of mercury and selenium with altered glutathione metabolism and oxidative stress in diving ducks from the San Francisco Bay region

    Science.gov (United States)

    Hoffman, D.J.; Ohlendorf, H.M.; Marn, C.M.; Pendleton, G.W.

    1998-01-01

    Adult male greater scaup (Aythya marila) (GS), surf scoters (Melanitta perspicillata)(SS), and ruddy ducks (Oxyura jamaicensis) (RD) were collected from Suisun Bay and coastal Tomales Bay in the greater San Francisco Bay area to assess exposure to inorganic contaminants. Hepatic selenium (Se) concentrations were highest in GS (geometric mean = 67 ppm, dw) and SS (119 ppm) in Suisun Bay, whereas hepatic mercury (Hg) was highest (19 ppm) in GS and SS from Tomales Bay. Hepatic Se and Hg were lower in RD and did not differ between locations. Hepatic supernatants were assayed for enzymes related to glutathione metabolism and antioxidant activity including: glucose-6-phosphate dehydrogenase (G-6-PDH), glutathione peroxidase (GSH-peroxidase), glutathione reductase (GSSG-reductase), and glutathione-S-transferase (GSH-transferase). GSH-peroxidase activity was higher in SS and RD, and G-6-PDH higher in GS and SS from Suisun Bay than Tomales Bay. GSSG-reductase was higher in SS from Suisun Bay. The ratio of oxidized glutathione (GSSG) to reduced glutathione (GSH) was greater in all species from Tomales Bay. The following significant relationships were found in one or more species with increasing hepatic Hg concentration: lower body, liver and heart weights; decreased hepatic GSH concentration, G-6-PDH and GSH-peroxidase activities; increased ratio of GSSG to GSH, and increased GSSG-reductase activity. With increasing hepatic Se concentration, GSH-peroxidase increased but GSH decreased. It is concluded that measurement of associated enzymes in conjunction with thiol status may be a useful bioindicator to discriminate between Hg and Se effects. Concentrations of mercury and selenium and variable affected have been associated with adverse effects on reproduction and neurological function in experimental studies with mallards.

  13. Inner Surf/Swash Zone Morphodynamic Numerical Model Simulation of an Accreting Ridge during Low-Energy Wave Conditions

    Science.gov (United States)

    Song, Youn Kyung; Figlus, Jens; Chardón-Maldonado, Patricia; Puleo, Jack A.

    2017-04-01

    The inner surf/swash zone of a coastal beach is characterized as an intermittently wet and dry zone in the nearshore that often develops a variety of morphological features including intertidal bars and ridge-runnel (RR) systems. The cross-shore morphodynamic numerical model CSHORE is used to simulate the beach recovery observed during a field experiment carried out at South Bethany Beach, Delaware, a nourished, high-gradient meso-tidal sandy beach along the U. S. Coast. The field campaign was conducted from February 12 to February 25, 2014 to measure bed profile morphology change and sediment characteristics along with detailed hydrodynamic forcing parameters at six cross-shore stations, closely spaced over approximately 50 m in the inner surf and swash zone. On February 13, 2014 a Nor'easter eroded significant portions of the beach leading to formation of a pronounced RR system on the beach face that subsequently accreted in the recovery process after the storm. Bed profile changes, surf and swash velocity profiles, water free surface elevation and suspended sediment concentrations recorded during the recovery at the cross-shore measuring locations on the seaward face of the accreting ridge are compared with CSHORE simulation results. During post-storm recovery, CSHORE demonstrates shoreward migration of the ridge and slight accretion on the beach face by the end of the simulation period on February 25, 2014. This trend was also observed in the field, where accretion at the ridge crest was up to 1.0 m with respect to the post-storm profile. The CSHORE parameters critical to improving model performance in reproducing measured morphodynamics and hydrodynamics during the ridge accretion process are examined and calibrated. Initial results show promise in using this type of efficient, process-based model to reproduce morphological evolution and depth-averaged hydrodynamics as a result of the complex surf and swash zone dynamics associated with beach accretion and RR

  14. Análisis descriptivo de la dinámica del surf como práctica social

    Directory of Open Access Journals (Sweden)

    Oscar Naranjo Del Giudice

    2014-05-01

    Full Text Available En este trabajo de investigación, la cultura del surf es analizada desde la teoría de la práctica social (Giraldo y Halliday 2012, Shove et al., 2012. Para este fin, se estudiaron cada uno de los elementos que conforman la práctica y la forma como estos se interrelacionan como un todo. Las ofertas de valor construidas pueden ser entendidas como constelaciones (Nornmann y Ramírez 1993 de recursos que mediante su integración contextual forman productos y servicios. Los datos fueron recolectados en un año mediante registros de campo, narrativas, registro fotográfico y observación participante. La información fue recolectada por parte de uno de los investigadores que pertenece a la comunidad de surf durante cuatro meses de manera permanentemente y durante ocho meses de manera intermitentes. Se encontró cómo la teoría de la práctica social puede explicar la dinámica del surf y como el surf puede agregar a la teoría de la práctica social un nuevo factor: la comunidad. La relación de interdependencia entre los aspectos pertenecientes a las prácticas sociales según (Giraldo y Halliday 2012, Shove et al., 2012, comprueba que el desarrollo de cada uno de ellos, afecta toda la práctica, lo cual requiere estudios profundos en cada segmento con el fin de crear, mejorar o destruir cualquier práctica social.

  15. Modeling aerosol surface chemistry and gas-particle interaction kinetics with K2-SURF: PAH oxidation

    Science.gov (United States)

    Shiraiwa, M.; Garland, R.; Pöschl, U.

    2009-04-01

    Atmospheric aerosols are ubiquitous in the atmosphere. They have the ability to impact cloud properties, radiative balance and provide surfaces for heterogeneous reactions. The uptake of gaseous species on aerosol surfaces impacts both the aerosol particles and the atmospheric budget of trace gases. These subsequent changes to the aerosol can in turn impact the aerosol chemical and physical properties. However, this uptake, as well as the impact on the aerosol, is not fully understood. This uncertainty is due not only to limited measurement data, but also a dearth of comprehensive and applicable modeling formalizations used for the analysis, interpretation and description of these heterogeneous processes. Without a common model framework, comparing and extrapolating experimental data is difficult. In this study, a novel kinetic surface model (K2-SURF) [Ammann & Pöschl, 2007; Pöschl et al., 2007] was used to describe the oxidation of a variety of polycyclic aromatic hydrocarbons (PAHs). Integrated into this consistent and universally applicable kinetic and thermodynamic process model are the concepts, terminologies and mathematical formalizations essential to the description of atmospherically relevant physicochemical processes involving organic and mixed organic-inorganic aerosols. Within this process model framework, a detailed master mechanism, simplified mechanism and parameterizations of atmospheric aerosol chemistry are being developed and integrated in analogy to existing mechanisms and parameterizations of atmospheric gas-phase chemistry. One of the key aspects to this model is the defining of a clear distinction between various layers of the particle and surrounding gas phase. The processes occurring at each layer can be fully described using known fluxes and kinetic parameters. Using this system there is a clear separation of gas phase, gas-surface and surface bulk transport and reactions. The partitioning of compounds can be calculated using the flux

  16. A CFD Model for Wave Transformation and Breaking in the Surf Zone

    Science.gov (United States)

    Chopakatla, S. C.; Lippmann, T. C.; Richardson, J. E.; Thornton, E. B.; Holman, R. A.

    2002-12-01

    Wind-generated surface gravity waves are the major driving force for nearshore circulation and sediment transport. As waves shoal in shallow coastal waters, spectra evolve strongly owing to refraction, nonlinear energy transfers, and dissipation caused by wave breaking and bottom friction. Although considerable progress has been made in modeling wave propagation over complex bottom topography, the dissipation mechanisms are still poorly understood. As a consequence, wave transformation models for the surf zone use crude descriptions of the wave breaking process based on simple saturation criteria or empirical probability distributions that do not always work well for the range of bathymetric and wave conditions commonly observed in nature. In this report, we will discuss the results of studies made with the commercially available Computational Fluid Dynamics (CFD) software system known as FLOW-3D (Flow Science, Inc., Sante Fe, NM). FLOW-3D is designed to solve transient, free surface flow problems based on the solution of the Navier-Stokes equations in three-dimensions. As part of FLOW-3D's formulation, the dissipation of energy is determined by use of coupled turbulence closure schemes (e.g., closure schemes based on the solution of turbulent kinetic energy transport equations). In this study, fine scale pressures and velocities are computed over a two-dimensional beach profile measured during the 1990 Delilah experiment. The model is driven by observed wave spectra obtained in 8 meter water depths, and results compared with a cross-shore array of pressure sensors and current meters spanning the width of the surf zone. In the calculations, wave breaking is a natural consequence of the fluid dynamics and does not require the use of empirical formulations, or breaking criteria. The spatial and temporal variability in the wave breaking locations will be compared with video observations obtained during the experiment. Good comparison between modeled and observed wave

  17. QSAR Study and VolSurf Characterization of Human Intestinal Absorption of Druge

    Institute of Scientific and Technical Information of China (English)

    胡桂香; 商志才; 等

    2003-01-01

    The prediction of human intestinal absorption is a major goal in the design,optimization,and selection of candidates for the develoment of oral drugs.In this study,a computerized method(VolSurf with GRID) was used as a novel tool for predicting human intestinal absorption of test compound,and for determining the critical molecular properties needed for human intestinal absorption.The tested molecules consisted of 20 diverse drug-like compounds.Partial least squares(PLS) discriminant analysis was used to correlate the experimental data with the theoretical molecular properties of human intestinal absorption.A good correlation(r2=0.95,q2=0.86) between the molecular modeling results and the experimental data demonstrated that human intestinal absorption could be predicted from the three-dimensional(3D) molecular structure of a compound .Favorable structureal properties identified for the potent intestinal absorption of drugs included strong imbalance between the center of mass of a molecule and the barycentre of its hydrophilic and hydrophobic regions and a definitive hydrophobic region as well as less hydrogen bonding donors and acceptors in the molecule.

  18. Hybrid Video Stabilization for Mobile Vehicle Detection on SURF in Aerial Surveillance

    Directory of Open Access Journals (Sweden)

    Gao Chunxian

    2015-01-01

    Full Text Available Detection of moving vehicles in aerial video sequences is of great importance with many promising applications in surveillance, intelligence transportation, or public service applications such as emergency evacuation and policy security. However, vehicle detection is a challenging task due to global camera motion, low resolution of vehicles, and low contrast between vehicles and background. In this paper, we present a hybrid method to efficiently detect moving vehicle in aerial videos. Firstly, local feature extraction and matching were performed to estimate the global motion. It was demonstrated that the Speeded Up Robust Feature (SURF key points were more suitable for the stabilization task. Then, a list of dynamic pixels was obtained and grouped for different moving vehicles by comparing the different optical flow normal. To enhance the precision of detection, some preprocessing methods were applied to the surveillance system, such as road extraction and other features. A quantitative evaluation on real video sequences indicated that the proposed method improved the detection performance significantly.

  19. Temporal and spatial variability of fecal indicator bacteria in the surf zone off Huntington Beach, CA

    Science.gov (United States)

    Rosenfeld, L.K.; McGee, C.D.; Robertson, G.L.; Noble, M.A.; Jones, B.H.

    2006-01-01

    Fecal indicator bacteria concentrations measured in the surf zone off Huntington Beach, CA from July 1998-December 2001 were analyzed with respect to their spatial patterns along 23 km of beach, and temporal variability on time scales from hourly to fortnightly. The majority of samples had bacterial concentrations less than, or equal to, the minimum detection limit, but a small percentage exceeded the California recreational water standards. Areas where coliform bacteria exceeded standards were more prevalent north of the Santa Ana River, whereas enterococci exceedances covered a broad area both north and south of the river. Higher concentrations of bacteria were associated with spring tides. No temporal correspondence was found between these bacterial events and either the timing of cold water pulses near shore due to internal tides, or the presence of southerly swell in the surface wave field. All three fecal indicator bacteria exhibited a diel cycle, but enterococci rebounded to high nighttime values almost as soon as the sun went down, whereas coliform levels were highest near the nighttime low tide, which was also the lower low tide. ?? 2006 Elsevier Ltd. All rights reserved.

  20. Enzyme as catalytic wheel powered by a Markovian engine: conformational coupling and barrier surfing models

    Science.gov (United States)

    Tsong, Tian Yow; Chang, Cheng-Hung

    2005-05-01

    We examine a typical Michaelis-Menten Enzyme (MME) and redress it to form a transducer of free energy, and electric, acoustic, or other types of energy. This amendment and extension is necessary in lieu of recent experiments in which enzymes are shown to perform pump, motor, and locomotion functions resembling their macroscopic counterparts. Classical textbook depicts enzyme, or an MME, as biocatalyst which can enhance the rate of a chemical reaction by lowering the activation barrier but cannot shift the thermodynamic equilibrium of the biochemical reaction. An energy transducer, on the other hand, must also be able to harvest, store, or divert energy and in doing so alter the chemical equilibrium, change the energy form, fuel an energy consuming process, or perform all these functions stepwise in one catalytic turnover. The catalytic wheel presented in this communication is both a catalyst and an energy transducer and can perform all these tasks with ease. A Conformational Coupling Model for the rotary motors and a Barrier Surfing Model for the track-guided stepping motors and transporters, are presented and compared. It is shown that the core engine of the catalytic wheel, or a Brownian motor, is a Markovian engine. It remains to be seen if this core engine is the basic mechanism for a wide variety of bio-molecular energy transducers, as well as certain other dynamic systems, for example, the Parrondo's Games.

  1. Surf Zone Hydrodynamics and its Utilization in Biotechnical Stabilization of Water Reservoir Banks

    Directory of Open Access Journals (Sweden)

    Petr Pelikán

    2014-01-01

    Full Text Available The water reservoir banks are eroded mainly by two factors. The first one is wave action (i.e. wave abrasion affecting the bank in direction from the reservoir. The second one is the influence of water flowing downward over the bank surface in direction from land into the reservoir (e.g. rainfall. The determination of regular altitudinal emplacement of proper designed particular biotechnical stabilization elements is the most important factor on which the right functionality of whole construction depends. Surf zone hydrodynamics solves the wave and water level changes inside the region extending from the wave breaking point to the limit of wave up-rush. The paper is focused on the utilization of piece of knowledge from a part of sea coast hydrodynamics and new approach in its application in the conditions of inland water bodies when designing the biotechnical stabilization elements along the shorelines. The “reinforced grass carpets” as a type of biotechnical method of bank stabilization are presented in the paper; whether the growth of grass root system is dependent on presence or absence of geomats in the soil structure and proceeding of their establishment on the shorelines.

  2. 3D-QSAR studies on UDP-glucuronosyltransferase 2B7 substrates using the pharmacophore and VolSurf approaches.

    Science.gov (United States)

    Ako, Roland; Dong, Dong; Wu, Baojian

    2012-09-01

    UDP-glucuronosyltransferase 2B7 (UGT2B7) is an important enzyme responsible for clearance of many drugs. Here, we report two 3D quantitative structure-activity relationship (QSAR) models for UGT2B7 using the pharmacophore and VolSurf approach, respectively. The dataset included 53 structurally diverse UGT2B7 substrates, 36 of which were used for the training set and 17 of which for the external test set. Pharmacophore-based 3D-QSAR model (or hypothesis) was developed using the Discovery Studio program. A user-defined "glucuronidation site" feature was forcefully included in a pharmacophore hypothesis. VolSurf-based 3D-QSAR model was generated using the VolSurf program. This involves calculation of VolSurf descriptors, variable selection with the FFD algorithm, and partial least squares (PLS) analyses. The best pharmacophore model (r(2) = 0.736) consists of one glucuronidation site, one hydrogen bond acceptor, and three hydrophobic regions. Using this model, K(m) values for 14 of 17 test substrates were predicted within one log unit. The yielded VolSurf (PLS) model with two components shows statistical significance in both fitting and internal predicting (r(2) = 0.866, q(2) = 0.728). Further, the K(m) values for all test substrates were predicted within one log unit. In addition, the VolSurf model reveals an overlay of chemical features influencing the enzyme-substrate binding. Those include molecular size and shape, integy moments, capacity factors, best volumes of DRY probe, H-bonding, and log P. In conclusion, the pharmacophore and VolSurf approaches are successfully utilized to establish predictive models for UGT2B7. The derived models should be an efficient tool for high throughput prediction of UGT2B7 metabolism.

  3. Prediction and assimilation of surf-zone processes using a Bayesian network: Part II: Inverse models

    Science.gov (United States)

    Plant, Nathaniel G.; Holland, K. Todd

    2011-01-01

    A Bayesian network model has been developed to simulate a relatively simple problem of wave propagation in the surf zone (detailed in Part I). Here, we demonstrate that this Bayesian model can provide both inverse modeling and data-assimilation solutions for predicting offshore wave heights and depth estimates given limited wave-height and depth information from an onshore location. The inverse method is extended to allow data assimilation using observational inputs that are not compatible with deterministic solutions of the problem. These inputs include sand bar positions (instead of bathymetry) and estimates of the intensity of wave breaking (instead of wave-height observations). Our results indicate that wave breaking information is essential to reduce prediction errors. In many practical situations, this information could be provided from a shore-based observer or from remote-sensing systems. We show that various combinations of the assimilated inputs significantly reduce the uncertainty in the estimates of water depths and wave heights in the model domain. Application of the Bayesian network model to new field data demonstrated significant predictive skill (R2 = 0.7) for the inverse estimate of a month-long time series of offshore wave heights. The Bayesian inverse results include uncertainty estimates that were shown to be most accurate when given uncertainty in the inputs (e.g., depth and tuning parameters). Furthermore, the inverse modeling was extended to directly estimate tuning parameters associated with the underlying wave-process model. The inverse estimates of the model parameters not only showed an offshore wave height dependence consistent with results of previous studies but the uncertainty estimates of the tuning parameters also explain previously reported variations in the model parameters.

  4. Estimate of Boundary-Layer Depth Over Beijing, China, Using Doppler Lidar Data During SURF-2015

    Science.gov (United States)

    Huang, Meng; Gao, Zhiqiu; Miao, Shiguang; Chen, Fei; LeMone, Margaret A.; Li, Ju; Hu, Fei; Wang, Linlin

    2016-09-01

    Planetary boundary-layer (PBL) structure was investigated using observations from a Doppler lidar and the 325-m Institute of Atmospheric Physics (IAP) meteorological tower in the centre of Beijing during the summer 2015 Study of Urban-impacts on Rainfall and Fog/haze (SURF-2015) field campaign. Using six fair-weather days of lidar and tower data under clear to cloudy skies, we evaluate the ability of the Doppler lidar to probe the urban boundary-layer structure, and then propose a composite method for estimating the diurnal cycle of the PBL depth using the Doppler lidar. For the convective boundary layer (CBL), a threshold method using vertical velocity variance (σ _w^2 >0.1 m2s^{-2}) is used, since it provides more reliable CBL depths than a conventional maximum wind-shear method. The nocturnal boundary-layer (NBL) depth is defined as the height at which σ _w^2 decreases to 10 % of its near-surface maximum minus a background variance. The PBL depths determined by combining these methods have average values ranging from ≈ 270 to ≈ 1500 m for the six days, with the greatest maximum depths associated with clear skies. Release of stored and anthropogenic heat contributes to the maintenance of turbulence until late evening, keeping the NBL near-neutral and deeper at night than would be expected over a natural surface. The NBL typically becomes more shallow with time, but grows in the presence of low-level nocturnal jets. While current results are promising, data over a broader range of conditions are needed to fully develop our PBL-depth algorithms.

  5. Estimate of Boundary-Layer Depth Over Beijing, China, Using Doppler Lidar Data During SURF-2015

    Science.gov (United States)

    Huang, Meng; Gao, Zhiqiu; Miao, Shiguang; Chen, Fei; LeMone, Margaret A.; Li, Ju; Hu, Fei; Wang, Linlin

    2017-03-01

    Planetary boundary-layer (PBL) structure was investigated using observations from a Doppler lidar and the 325-m Institute of Atmospheric Physics (IAP) meteorological tower in the centre of Beijing during the summer 2015 Study of Urban-impacts on Rainfall and Fog/haze (SURF-2015) field campaign. Using six fair-weather days of lidar and tower data under clear to cloudy skies, we evaluate the ability of the Doppler lidar to probe the urban boundary-layer structure, and then propose a composite method for estimating the diurnal cycle of the PBL depth using the Doppler lidar. For the convective boundary layer (CBL), a threshold method using vertical velocity variance (σ _w^2 >0.1 m2s^{-2}) is used, since it provides more reliable CBL depths than a conventional maximum wind-shear method. The nocturnal boundary-layer (NBL) depth is defined as the height at which σ _w^2 decreases to 10 % of its near-surface maximum minus a background variance. The PBL depths determined by combining these methods have average values ranging from ≈ 270 to ≈ 1500 m for the six days, with the greatest maximum depths associated with clear skies. Release of stored and anthropogenic heat contributes to the maintenance of turbulence until late evening, keeping the NBL near-neutral and deeper at night than would be expected over a natural surface. The NBL typically becomes more shallow with time, but grows in the presence of low-level nocturnal jets. While current results are promising, data over a broader range of conditions are needed to fully develop our PBL-depth algorithms.

  6. Size spectra of bubbles in the foam patches and of sea salt nuclei over the surf zone

    OpenAIRE

    Podzimek, Josef

    2011-01-01

    The size distribution of bubbles in the foam patches and the size distribution of giant chloridenuclei over the surf zone both follow the Nukiyama-Tanassava size distribution function. Theslope of the size distribution curve for bubbles depends, however, on the residence time of thefoam patch at the ocean surface. The best fit of the sea salt nuclei size distribution curve wasfound for s = 0.333 in the Nukiyama-Tanassava distribution.DOI: 10.1111/j.1600-0889.1984.tb00241.x

  7. Diseño de un programa de Surf recreativo enfocado a colectivos con Síndrome de Down de 6 a 10 años

    OpenAIRE

    Iriarte Gomara, Pablo

    2015-01-01

    El objetivo de este trabajo es diseñar un programa de surf recreativo enfocado a colectivos con Síndrome de Down de 6 a 10 años. El Síndrome de Down se define como una discapacidad intelectual causada por una alteración en el par de cromosomas 21 (OMS, 2011). Resulta de especial relevancia el tratamiento de dicha discapacidad de manera no farmacológica, destacando la actividad física, en este caso el surf, como elemento inclusivo a nivel físico, psicológico y social. Se analizan distintos pro...

  8. On the resonance hypothesis of storm surge and surf beat run-up

    Science.gov (United States)

    Postacioglu, Nazmi; Sinan Özeren, M.; Canlı, Umut

    2017-06-01

    Resonance has recently been proposed as the fundamental underlying mechanism that shapes the amplification in coastal run-up for storm surges and surf beats, which are long-wavelength disturbances created by fluid velocity differences between the wave groups and the regions outside the wave groups. It is without doubt that the resonance plays a role in run-up phenomena of various kinds; however, we think that the extent to which it plays its role has not been completely understood. For incident waves, which we assume to be linear, the best approach to investigate the role played by the resonance would be to calculate the normal modes by taking radiation damping into account and then testing how those modes are excited by the incident waves. Such modes diverge offshore, but they can still be used to calculate the run-up. There are a small number of previous works that attempt to calculate the resonant frequencies, but they do not relate the amplitudes of the normal modes to those of the incident wave. This is because, by not including radiation damping, they automatically induce a resonance that leads to infinite amplitudes, thus preventing them from predicting the exact contribution of the resonance to coastal run-up. In this study we consider two different coastal geometries: an infinitely wide beach with a constant slope connecting to a flat-bottomed deep ocean and a bay with sloping bottom, again, connected to a deep ocean. For the fully 1-D problem we find significant resonance if the bathymetric discontinuity is large.The linearisation of the seaward boundary condition leads to slightly smaller run-ups. For the 2-D ocean case the analysis shows that the wave confinement is very effective when the bay is narrow. The bay aspect ratio is the determining factor for the radiation damping. One reason why we include a bathymetric discontinuity is to mimic some natural settings where bays and gulfs may lead to abrupt depth gradients such as the Tokyo Bay. The other

  9. A Comprehensive Motion Estimation Technique for the Improvement of EIS Methods Based on the SURF Algorithm and Kalman Filter.

    Science.gov (United States)

    Cheng, Xuemin; Hao, Qun; Xie, Mengdi

    2016-04-07

    Video stabilization is an important technology for removing undesired motion in videos. This paper presents a comprehensive motion estimation method for electronic image stabilization techniques, integrating the speeded up robust features (SURF) algorithm, modified random sample consensus (RANSAC), and the Kalman filter, and also taking camera scaling and conventional camera translation and rotation into full consideration. Using SURF in sub-pixel space, feature points were located and then matched. The false matched points were removed by modified RANSAC. Global motion was estimated by using the feature points and modified cascading parameters, which reduced the accumulated errors in a series of frames and improved the peak signal to noise ratio (PSNR) by 8.2 dB. A specific Kalman filter model was established by considering the movement and scaling of scenes. Finally, video stabilization was achieved with filtered motion parameters using the modified adjacent frame compensation. The experimental results proved that the target images were stabilized even when the vibrating amplitudes of the video become increasingly large.

  10. Relationship between high-frequency sediment-level oscillations in the swash zone and inner surf zone wave characteristics under calm wave conditions

    Directory of Open Access Journals (Sweden)

    Li Zhiqiang

    2016-01-01

    Full Text Available Swash zone topography rapidly responds to the surf zone waves. Understanding how sandy beaches respond to wave action is critical for beach erosion research, and plays a critical role in the design and maintenance of shore protection structures. The main objectives of this study were to detect the relationship between high-frequency beachface oscillations and surf zone wave characteristics under plunging breakers by using Canonical Correlation Analysis (CCA. The study site is located in Houjiangwan Bay, eastern Guangdong. Topography data were sampled at 6 min intervals. The wave characteristic parameters were calculated by spectrum method. During the field work, the beach showed a reflective state and plunging breakers controlled the surf zone. The beach cusp topography was destructed gradually. The analysis provides 4 canonical correlation processes between the beachface variations and surf zone waves, which explained 95.28% of the overall variation in the data. The result shows wave steepness, the irregularity factor and spectral broadness factor had strong impacts on the topography. The wave steepness was the most important factor for beach profile variations. The results of the present study indicate that data-driven statistical analysis, such as CCA, is useful for analyzing profile response to waves if there is strong correlation between the two variables (beach profiles and wave.

  11. On the use of the fictitious wave steepness and related surf-similarity parameters in methods that describe the hydraulic and structural response to waves

    NARCIS (Netherlands)

    Heineke, D.; Verhagen, H.J.

    2007-01-01

    To assess the hydraulic performance of coastal structures - viz. wave run-up, overtopping and reflection - and to evaluate the stability of the armour layers, use is made of the dimensionless surf similarity parameter, as introduced by Battjes (1974). The front side slope of the structure and the wa

  12. On the use of the fictitious wave steepness and related surf-similarity parameters in methods that describe the hydraulic and structural response to waves

    NARCIS (Netherlands)

    Heineke, D.; Verhagen, H.J.

    2007-01-01

    To assess the hydraulic performance of coastal structures - viz. wave run-up, overtopping and reflection - and to evaluate the stability of the armour layers, use is made of the dimensionless surf similarity parameter, as introduced by Battjes (1974). The front side slope of the structure and the

  13. Numerical study of pollutant movement in waves and wave-induced long-shore currents in surf zone

    Institute of Scientific and Technical Information of China (English)

    TANG Jun; SHEN Yongming; QIU Dahong

    2008-01-01

    Water waves,wave-induced long-shore currents and movement of pollutants in waves and currents have been numerically studied based on the hyperbolic mild-slope equation,the shallow water equation,as well as the pollutant movement equation,and the nu- merical results have also been validated by experimental data.It is shown that the long-shore current velocity and wave set-up in- crease with the increasing incident wave amplitude and slope steepness of the shore plane;the wave set-up increases with the in- creasing incident wave period;and the pollutant morement proceeds more quiekly with the increasing incident wave amplitude and slope steepness of the shore palane.In surf zones,the long-shore currents induced by the inclined incident waves have effectively affected the pollutant movement.

  14. Recomendações de Gestão dos Recifes Artificiais para a Prática do Surfe

    Directory of Open Access Journals (Sweden)

    Marco Antonio Moraes Ocke

    2016-05-01

    Full Text Available Os recifes artificiais são estruturas afundadas em ambiente marinho a fim de oferecer múltiplos usos e beneficiar um maior número de usuários. Entretanto, sua capacidade de propiciar melhores condições de surfe tem sido a principal característica atrativa para experiências já realizadas em alguns países do mundo. Neste contexto, esta pesquisa tem o objetivo de apresentar um conjunto de recomendações que possam contribuir com gestores públicos e privados que planejam incluir a implantação de recifes artificiais tendo como foco a melhoria nas condições de surfe em suas localidades. Para tanto, esta pesquisa qualitativa exploratória se desenvolve a partir de breve revisão teórica sobre o tema e de um estudo de casos múltiplos – Austrália, Estados Unidos, Nova Zelândia, India e Inglaterra - para sustentar o raciocínio. Os resultados incluem o caráter inovador deste tipo de estrutura demandando um aprimoramento nos métodos de construção e gestão, programas de monitoramento de longo prazo para avaliação de eficácia, desafios na integração de usuários, participação pública nas diferentes etapas do processo, gestão das expectativas dos mercados envolvidos. Uma vez que poucos estudos referentes ao tema foram desenvolvidos até o presente momento, as análises presentes neste trabalho podem contribuir com o preenchimento desta lacuna no conhecimento.

  15. Implementation and modification of a three-dimensional radiation stress formulation for surf zone and rip-current applications

    Science.gov (United States)

    Kumar, N.; Voulgaris, G.; Warner, J.C.

    2011-01-01

    Regional Ocean Modeling System (ROMS v 3.0), a three-dimensional numerical ocean model, was previously enhanced for shallow water applications by including wave-induced radiation stress forcing provided through coupling to wave propagation models (SWAN, REF/DIF). This enhancement made it suitable for surf zone applications as demonstrated using examples of obliquely incident waves on a planar beach and rip current formation in longshore bar trough morphology (Haas and Warner, 2009). In this contribution, we present an update to the coupled model which implements a wave roller model and also a modified method of the radiation stress term based on Mellor (2008, 2011a,b,in press) that includes a vertical distribution which better simulates non-conservative (i.e., wave breaking) processes and appears to be more appropriate for sigma coordinates in very shallow waters where wave breaking conditions dominate. The improvements of the modified model are shown through simulations of several cases that include: (a) obliquely incident spectral waves on a planar beach; (b) obliquely incident spectral waves on a natural barred beach (DUCK'94 experiment); (c) alongshore variable offshore wave forcing on a planar beach; (d) alongshore varying bathymetry with constant offshore wave forcing; and (e) nearshore barred morphology with rip-channels. Quantitative and qualitative comparisons to previous analytical, numerical, laboratory studies and field measurements show that the modified model replicates surf zone recirculation patterns (onshore drift at the surface and undertow at the bottom) more accurately than previous formulations based on radiation stress (Haas and Warner, 2009). The results of the model and test cases are further explored for identifying the forces operating in rip current development and the potential implication for sediment transport and rip channel development. Also, model analysis showed that rip current strength is higher when waves approach at angles of 5

  16. Spatial and temporal variations of diurnal ichthyofauna on surf-zone of São Francisco do Itabapoana beaches, Rio de Janeiro State, Brazil

    Directory of Open Access Journals (Sweden)

    Gomes Marcelo Paes

    2003-01-01

    Full Text Available Spatial and temporal variations of diurnal ichthyofauna and the environmental variables influences on its distribution were studied at the surf-zone of three beaches of São Francisco do Itabapoana, northern coast of Rio de Janeiro, Brazil. From August/1999 to August/2000, three beach seine hauls were made monthly, and environmental variables were recorded. A total number of 4,562 fishes (74,155g were sampled at the three beaches, where estuarine-dependent species prevailed (44%, followed by marine (31%, estuarine (19% and freshwater species (3%. Species richness, number of individuals and wet weight were significantly higher at Gargaú, followed by Manguinhos and Barra do Itabapoana, respectively. Canonical Correspondence Analysis highlighted influences of the rivers flushing, salinity and plant abundance on the diurnal ichthyofauna distribution and dynamics of São Francisco do Itabapoana surf-zone.

  17. The design and implementation of a semi-autonomous surf-zone robot using advanced sensors and a common robot operating system

    OpenAIRE

    Hickle, Jason.; Halle, Steven

    2011-01-01

    Approved for public release; distribution is unlimited. A semi-autonomous vehicle, MONTe, was designed, modeled and tested for deployment and operation in a surf-zone coastal environment. The MONTe platform was designed to use unique land based locomotion that incorporates wheel-legs(WhegsTM) and a tail. Semi-autonomy was realized with data from onboard sensors and implemented through open source Robot Operating System (ROS), hosted on an Ubuntu Linux based processor. Communications vi...

  18. Three-dimensional modelling of wave-induced current from the surf zone to the inner shelf

    Directory of Open Access Journals (Sweden)

    H. Michaud

    2011-12-01

    Full Text Available We develop and implement a new method to take into account the impact of waves into the 3-D circulation model SYMPHONIE (Marsaleix et al., 2008, 2009a, following the simplified equations of Bennis et al. (2011 which use glm2z-RANS theory (Ardhuin et al., 2008b. These adiabatic equations are completed by additional parameterizations of wave breaking, bottom friction and wave-enhanced vertical mixing, making the forcing valid from the surf zone through to the open ocean. The wave forcing is performed by wave generation and propagation models WAVEWATCH III® (Tolman, 2008, 2009; Ardhuin et al., 2010 and SWAN (Booij et al., 1999. The model is tested and compared with other models for a plane beach test case, previously tested by Haas and Warner (2009 and Uchiyama et al. (2010. A comparison is also made with the laboratory measurements of Haller et al. (2002 of a barred beach with channels. Results fit with previous simulations performed by other models and with available observational data.

    Finally, a realistic case of energetic waves travelling over a coast of the Gulf of Lion (in the northwest of the Mediterranean Sea for which currents are available at different depths as well as an accurate bathymetric database of the 0–10 m depth range, is then simulated. A grid nesting approach is used to account for the different forcings acting at different spatial scales. The simulation coupling the effects of waves and currents is successful to reproduce the powerful northward littoral drift in the 0–15 m depth zone. More precisely, two distinct cases are identified: when waves have a normal angle of incidence with the coast, they are responsible for complex circulation cells and rip currents in the surf zone, and when they travel obliquely, they generate a northward littoral drift. These features are more complicated than in the test cases, due to the complex bathymetry and the consideration of wind and non-stationary processes. Wave impacts

  19. Three-dimensional modelling of wave-induced current from the surf zone to the inner shelf

    Directory of Open Access Journals (Sweden)

    H. Michaud

    2012-08-01

    Full Text Available We develop and implement a new method to take into account the impact of waves into the 3-D circulation model SYMPHONIE (Marsaleix et al., 2008, 2009a following the simplified equations of Bennis et al. (2011 which use glm2z-RANS theory (Ardhuin et al., 2008c. These adiabatic equations are completed by additional parameterizations of wave breaking, bottom friction and wave-enhanced vertical mixing, making the forcing valid from the surf zone through to the open ocean. The wave forcing is performed by wave generation and propagation models WAVEWATCH III® (Tolman, 2008, 2009; Ardhuin et al., 2010 and SWAN (Booij et al., 1999. The model is tested and compared with other models for a plane beach test case, previously tested by Haas and Warner (2009and Uchiyama et al. (2010. A comparison is also made with the laboratory measurements of Haller et al. (2002 of a barred beach with channels. Results fit with previous simulations performed by other models and with available observational data.

    Finally, a realistic case is simulated with energetic waves travelling over a coast of the Gulf of Lion (in the northwest of the Mediterranean Sea for which currents are available at different depths as well as an accurate bathymetric database of the 0–10 m depth range. A grid nesting approach is used to account for the different forcings acting at different spatial scales. The simulation coupling the effects of waves and currents is successful to reproduce the powerful northward littoral drift in the 0–15 m depth zone. More precisely, two distinct cases are identified: When waves have a normal angle of incidence with the coast, they are responsible for complex circulation cells and rip currents in the surf zone, and when they travel obliquely, they generate a northward littoral drift. These features are more complicated than in the test cases, due to the complex bathymetry and the consideration of wind and non-stationary processes. Wave impacts in the

  20. Structural aspects of the surf-zone fish assemblage at King's Beach, Algoa Bay, South Africa: Long-term fluctuations

    Science.gov (United States)

    Lasiak, Theresa A.

    1984-04-01

    Regular collections of fish were obtained from the surf-zone at King's Beach, Algoa Bay. A total of 3970 fish, representing 50 species was caught with a coarse net and 16 857 fish, representing 37 species, were caught with a fine net. Predominant species were the blacktail, Diplodus sargus; the sand steenbras, Lithognathus mormyrus; the mullet, Liza richardsoni; the gorrie, Pomadasys olivaceum; the white stumpnose, Rhabdosargus globiceps; the sandshark, Rhinobatos annulatus; and the streepie, Sarpa salpa. No seasonal trends were discernible in the overall abundance or species diversity. The species composition of the dominant component of the fish assemblage varied considerably. This indicated instability in the community structure and cast doubts on the applicability of a classic community concept and the use of diversity indices. Neither classification nor correspondence analysis were of any use in identifying a characteristic species component. Multiple regression analysis indicated that short-term variations in wind conditions might be a primary determinant of fluctuations in abundance. The lack of seasonality in the community parameters may reflect the fact that short-term variability masks seasonal perturbations.

  1. The Surf Zone Ichthyoplankton Adjacent to an Intermittently Open Estuary, with Evidence of Recruitment during Marine Overwash Events

    Science.gov (United States)

    Cowley, P. D.; Whitfield, A. K.; Bell, K. N. I.

    2001-03-01

    The composition, structure and seasonality of ichthyoplankton in the surf zone adjacent to the mouth of the intermittently open East Kleinemonde Estuary (33°32'S, 27°03'E) were investigated over a period of 2 years. Altogether 451 fishes, representing at least 21 taxa from 14 families, were collected. The assemblage was dominated by postflexion larvae of euryhaline marine species that are dependent on estuaries as nursery areas. The sparid Rhabdosargus holubi was the most abundant taxon and constituted more than 77% of the total catch. A distinct modal size class was identified for R. holubi , while the mean individual size of this and other abundant taxa was comparable to the observed recruitment size range reported from a wide variety of estuarine nursery habitats in southern Africa. Periodic regression analyses revealed significant peaks in abundance of larval R. holubi during late winter (August), at down and dusk, at new and full moon (spring tides), and on the flood stage of the tidal cycle. Evidence for estuarine immigration during marine overwash events (surging rough seas that enter the estuary) is provided by (1) the stranding of postflexion larvae in the region of the closed estuary mouth following these events, and (2) back extrapolation from length modes within the estuary to coincide with such an event. The advantages and disadvantages of such a recruitment strategy are discussed.

  2. Feature description with SIFT, SURF, BRIEF, BRISK, or FREAK? A general question answered for bone age assessment.

    Science.gov (United States)

    Kashif, Muhammad; Deserno, Thomas M; Haak, Daniel; Jonas, Stephan

    2016-01-01

    Solving problems in medical image processing is either generic (being applicable to many problems) or specific (optimized for a certain task). For example, bone age assessment (BAA) on hand radiographs is a frequent but cumbersome task for radiologists. For this problem, many specific solutions have been proposed. However, general-purpose feature descriptors are used in many computer vision applications. Hence, the aim of this study is (i) to compare the five leading keypoint descriptors on BAA, and, in doing so, (ii) presenting a generic approach for a specific task. Two methods for keypoint selection were applied: sparse and dense feature points. For each type, SIFT, SURF, BRIEF, BRISK, and FREAK feature descriptors were extracted within the epiphyseal regions of interest (eROI). Classification was performed using a support vector machine. Reference data (1101 radiographs) of the University of Southern California was used for 5-fold cross-validation. The data was grouped into 30 classes representing the bone age range of 0-18 years. With a mean error of 0.605 years, dense SIFT gave best results and outperforms all published methods. The accuracy was 98.36% within the range of 2 years. Dense SIFT represents a generic method for a specific question.

  3. Rancang Bangun Game Aksi dengan Integrasi dan Pengenalan Gambar Menggunakan Algoritma Ekstraksi Fitur SURF dan Klasifikasi SVM pada Perangkat Android

    Directory of Open Access Journals (Sweden)

    Bryan Nandriawan

    2017-01-01

    Full Text Available Saat ini perangkat mobile berbasis Android dan iOS sangat digemari oleh anak-anak. Mereka yang telah memiliki perangkat mobile akan menghabiskan seluruh waktunya untuk menatap layar perangkat saat bermain. Akibat yang ditimbulkan adalah penurunan kesehatan mata dan kurangnya bersosialisasi dengan teman sebaya. Menggambar adalah hal yang disukai anak-anak. Dengan menggabungkan menggambar dengan permainan perangkat mobile, anak-anak akan tetap merasa bermain meski mereka sedang tidak menatap layar untuk menggambar. Tugas akhir ini bertujuan untuk membangun sebuah permainan yang dapat mengenali gambar dan menggunakan gambar tersebut dalam permainan. Metode pengenalan gambar dalam tugas akhir ini dilakukan dengan menggunakan metode Edge Detection dengan algoritma ekstraksi fitur SURF (Speeded-Up Robust Features dan klasifikasi SVM (Support Vector Machine. Jenis permainan yang dibangun merupakan gabungan dari aksi dan tower defense. Hasil dari tugas akhir ini dibagi menjadi 3 yaitu hasil fungsionalitas permainan, hasil daya tarik permainan dan hasil akurasi pengenalan gambar. Semua fungsi yang dibuat pada permainan dapat berjalan dengan baik, dan permainan juga telah memiliki daya tarik yang memikat. Namun hasil akurasi pengenalan gambar masih kurang dari harapan penulis.

  4. PADDLING PERFORMANCE AND RANKING POSITION IN JUNIOR SURFERS COMPETING AT THE ASSOCIATION OF SURFING PROFESSIONALS: A PILOT STUDY

    Directory of Open Access Journals (Sweden)

    Jesús Cámara

    2011-11-01

    Full Text Available Abstract  The aims of this pilot study are on one hand, to evaluate the upper body aerobic characteristics of junior surfers competing at the European branch of the Association of Surfing Professionals (ASP and on the other, to assess the relationship between the junior surfers' upper body aerobic characteristics and their ranking position. Ten surfers competing at the European junior branch of the ASP took part in the study. The maximal oxygen uptake (VO2MAX, the maximum power output (WMAX, the maximum lactate concentration [La]MAX, the maximum heart rate (HRMAX and the power output at the intensity where the lactate threshold and the onset of blood lactate accumulation are produced (WLT and WOBLA were determined during an incremental maximal test in a swim bench ergometer. It was observed a lack of a significant relationship between the ranking position and the parameters at maximal intensity (VO2PEAK, WMAX, HRMAX y [La]MAX. The WLT (W · kg-1 and the WOBLA (W · kg-1 were significantly related to ranking position (r= -0.69, p= 0.02; r= -0.72, p= 0.01, respectively.

  5. Self-organizing maps and VolSurf approach to predict aldose reductase inhibition by flavonoid compounds

    Directory of Open Access Journals (Sweden)

    Luciana Scotti

    2011-02-01

    Full Text Available Aldose Reductase (AR is the polyol pathway key enzyme which converts glucose to sorbitol. High glucose availability in insulin resistant tissues in diabetes leads into an accumulation of sorbitol, which has been associated with typical chronic complications of this disease, such as neuropathy, nephropathy and retinopathy. In this study, 71 flavonoids AR inhibitors were subjected to two methods of SAR to verify crucial substituents. The first method used the PCA (Principal Component Analysis to elucidate physical and chemical characteristics in the molecules that would be essential for the activity, employing VolSurf descriptors. The rate obtained explained 53% of the system total variance and revealed that a hydrophobic-hydrophilic balance in the molecules is required, since very polar or nonpolar substituents decrease the activity. Artificial Neural Networks (ANNs was also employed to determine key substituents by evaluating substitution patterns, using NMR data. This study had a high success rate (85% accuracy in the training set and 88% accuracy in the test set and showed polihydroxilations are essential for high activity and methoxylations and glicosilations primarily at positions C7, C3' and C4' decrease the activity.

  6. White-winged Scoter - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  7. Home-loving boreal hare mitochondria survived several invasions in Iberia: the relative roles of recurrent hybridisation and allele surfing.

    Science.gov (United States)

    Melo-Ferreira, J; Farelo, L; Freitas, H; Suchentrunk, F; Boursot, P; Alves, P C

    2014-03-01

    Genetic introgression from a resident species into an invading close relative can result from repeated hybridisation along the invasion front and/or allele surfing on the expansion wave. Cases where the phenomenon is massive and systematic, such as for hares (genus Lepus) in Iberia, would be best explained by recurrent hybridisation but this is difficult to prove because the donor populations are generally extinct. In the Pyrenean foothills, Lepus europaeus presumably replaced Lepus granatensis recently and the present species border is parallel to the direction of invasion, so that populations of L. granatensis in the contact zone represent proxies of existing variation before the invasion. Among three pairs of populations sampled across this border, we find less differentiation of mitochondrial DNA (mtDNA) across than along it, as predicted under recurrent hybridisation at the invasion front. Using autosomal microsatellite loci and X- and Y-linked diagnostic loci, we show that admixture across the border is quasi-absent, making it unlikely that lack of interspecific mtDNA differentiation results from ongoing gene flow. Furthermore, we find that the local species ranges are climatically contrasted, making it also unlikely that ongoing ecology-driven movement of the contact account for mtDNA introgression. The lack of mtDNA differentiation across the boundary is mostly due to sharing of mtDNA from a boreal species currently extinct in Iberia (Lepus timidus) whose mitochondria have thus remained in place since the last deglaciation despite successive invasions by two other species. Home-loving mitochondria thus witness past species distribution rather than ongoing exchanges across stabilised contact zones.

  8. SURF-based position estimation method using aerial image sequences.%基于SURF特征的航空序列图像位置估计算法

    Institute of Scientific and Technical Information of China (English)

    乔奎贤; 赵妮; 李耀军

    2013-01-01

    视觉传感器在航空无人机导航和定位任务中应用越来越广泛。针对无人机位置参数估计问题,提出了一种基于SURF特征的图像配准算法,该算法能够适应航空序列图像的旋转、尺度变换及噪声干扰,实现无人机位置的精确估计。构建了SURF尺度空间,运用快速Hessian矩阵定位极值点,计算出航空图像的64维SURF特征描述子;基于Hessian矩阵迹完成特征点匹配;使用RANSAC算法剔除出格点,实现位置参数的精确估计。通过航空图像序列实测数据位置估计实验,验证了该算法的有效性。%Vision sensor is widely used in the aviation aircraft navigation and positioning tasks. For position parameter estima-tion of aircraft, this paper presents a SURF feature based image registration algorithm, it is able to adapt to aerial image sequence rotation, scale transformation and noise, to achieve accurate estimates of aircraft position. It builds SURF scale space, uses fast Hessian matrix maximum values to calculate 64-dimensional SURF feature descriptors of aerial images. Based on the trace of the Hessian matrix, it completes feature points matching task. By using RANSAC algorithm, it removes the outliers matching points for accurate position estimate. Experiments with two real aerial image sequences show the effectiveness of the proposed position estimation algorithm.

  9. 基于SURF算子的快速手背静脉识别%Fast recognition of hand vein with SURF descriptors

    Institute of Scientific and Technical Information of China (English)

    李秀艳; 刘铁根; 邓仕超; 何瑾; 王云新

    2011-01-01

    A recognition algorithm for hand vein based on speeded-up robust features( SURF) was proposed. Firstly,the region of interest ( ROI) of the hand vein image is obtained through image preprocessing. The local SURF features of test sample and register samples are extracted and matched based on Euclid distance, and then the mismatching pairs are rejected. Finally, the matching rate is calculated as the similarity between registered sample and test sample to realize personal identity recognition. The recognition performance was evaluated in verification mode using TJU hand vein image database, the equal error rate ( EER) is 0.07% and average recognition time is 0.153 s. Experimental results show that the proposed algorithm is able to realize hand vein recognition reliably and quickly.%提出基于加速鲁棒性特征(speeded-up robustfeatures,SURF)的手背静脉识别算法.首先对手背静脉图像进行预处理,提取手背静脉感兴趣区域(ROI),然后提取手背静脉的局部SURF特征,基于欧式距离实现测试样本和注册样本特征点的匹配,并剔除错误匹配对,最后计算匹配率作为待识别样本和注册样本之间的相似度测试实现身份识别.利用TJU手背静脉图像数据库对算法性能进行测试,在认证模式下等错率为0.07%,平均识别时间0.153 s.实验结果证明该算法可以快速有效地实现手背静脉识别.

  10. 基于特性分析的SURF加速方法研究%RESEARCH ON SPEED-UP METHOD OF SURF THROUGH PROPERTIES ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    胡益斌; 肖菁; 戴卓方; 李戈; 张为华

    2012-01-01

    To resolve the problem of a little bit low speed the typical image feature extraction algorithm SURF (speeded up robust feature) has, in the paper we do an in-depth analysis on the algorithm properties in regard to its running time, instruction type, memory access, hot spots,and etc. On this basis, we optimise the SURF algorithm by reconstructing the judgment logic, the memory accessing and data organisations,the library functions implementation and other strategies. Moreover,we analyse the role of speedup of each optimisation strategy on the algorithm through experiments. And experimental data show that these optimisation strategies can effectively improve the running efficiency of SURF in the premise of guaranteeing 100% accuracy of the algorithm, and 2. 75X ultimate performance improvement is achieved.%针对典型图像特征提取算法SURF速度偏慢的问题,深入分析该算法在运行时间、指令类型、内存访问、热点等方面的特性.在此基础上,运用重构判断逻辑、重构内存访问与数据组织形式、重构库函数实现等策略对SURF算法进行优化.并通过实验,分析各种优化策略对算法的加速作用.实验数据显示,这些优化策略可以在保证算法100%精确的前提下,有效地提高SURF算法的运行效率,最终达到2.75X的性能提升.

  11. Diversity and abundance of water birds in a subarctic lake during three decades

    Directory of Open Access Journals (Sweden)

    Anders Klemetsen

    2013-12-01

    Full Text Available The numbers of divers, ducks, gulls, terns and waders in the 15 km2 oligotrophic lake Takvatn, North Norway were estimated six times during 1983-2012. Systematic mapping surveys were done by boat within the first week after ice-break in June. Twenty-one species were observed over the years and 12 were regarded as breeding on the lake. Red-breasted merganser Mergus serrator was the dominant diving bird, with estimated minimum number of pairs varying from 15 to 39 among years. Black-throated diver Gavia arctica (1-3 pairs, tufted duck Aythya fuligula (2-15 pairs and common scoter Melanitta nigra (1-5 pairs bred regularly, while velvet scoter Melanitta fusca (1-2 and goldeneye Bucephala clangula (2-4 were found in some years and mallard Anas platyrhynchos (1 pair and wigeon Anas penelope (1 pair in one year. Common gull Larus canus (6-30 pairs and arctic tern Sterna paradisaea (2-35 pairs bred in all years. Common sandpiper Tringa hypoleucos (3-9 pairs and redshank Tringa totanus (1-4 pairs were regular waders. Density variations of mergansers, gulls and terns are possibly related to density variations of three-spined sticklebacks Gasterosteus aculeatus, their dominant fish prey. The water birds are important links in the food web of the lake.

  12. Webpage Recommendation Model in Personal Surfing%个性化浏览中网页推荐的结构模型

    Institute of Scientific and Technical Information of China (English)

    苏贵洋; 王永成; 马颖华

    2003-01-01

    This paper first introduces the inevitability direction of Internet personal technique's development, and then analyzes the differences between Information Retrieval and Information Filtering. Further more, combining with the group user interests and individual user interests, using VSM and FCM algorithm, this paper proposes a webpage recommendation model in personal surfing. This model can be applied not only in single website, but also in enterprise information collecting system. It also brings forward a method to extend concept. The advantage of the model is automatic concepts learning in the processing of user's feedback and browsing. Contrasting to concept dictionary method, it is more agility and gains well retrieval results.

  13. Diversificação na gestão estratégica em microempresas de ensino do surfe: um estudo multicasos

    OpenAIRE

    Cruz, Ana Carolina Costa

    2015-01-01

    Podemos observar a existência de diversas estratégias que norteiam o desenvolvimento de um negócio. Uma delas é a diversificação. Esta dissertação apresenta um estudo da diversificação na gestão estratégica de microempresas de ensino do surfe (MEES) do Rio de Janeiro. No caso das MEES, há particularidades que tornam muito importante a diversificação para a sobrevivência e desenvolvimento delas. Por isso, escolhemos estudar o tema nesse tipo de empresa. A pesquisa analisou o processo de divers...

  14. Observations of wave-induced pore pressure gradients and bed level response on a surf zone sandbar

    Science.gov (United States)

    Anderson, Dylan; Cox, Dan; Mieras, Ryan; Puleo, Jack A.; Hsu, Tian-Jian

    2017-06-01

    Horizontal and vertical pressure gradients may be important physical mechanisms contributing to onshore sediment transport beneath steep, near-breaking waves in the surf zone. A barred beach was constructed in a large-scale laboratory wave flume with a fixed profile containing a mobile sediment layer on the crest of the sandbar. Horizontal and vertical pore pressure gradients were obtained by finite differences of measurements from an array of pressure transducers buried within the upper several centimeters of the bed. Colocated observations of erosion depth were made during asymmetric wave trials with wave heights between 0.10 and 0.98 m, consistently resulting in onshore sheet flow sediment transport. The pore pressure gradient vector within the bed exhibited temporal rotations during each wave cycle, directed predominantly upward under the trough and then rapidly rotating onshore and downward as the wavefront passed. The magnitude of the pore pressure gradient during each phase of rotation was correlated with local wave steepness and relative depth. Momentary bed failures as deep as 20 grain diameters were coincident with sharp increases in the onshore-directed pore pressure gradients, but occurred at horizontal pressure gradients less than theoretical critical values for initiation of the motion for compact beds. An expression combining the effects of both horizontal and vertical pore pressure gradients with bed shear stress and soil stability is used to determine that failure of the bed is initiated at nonnegligible values of both forces.Plain Language SummaryThe pressure gradient present within the seabed beneath breaking waves may be an important physical mechanism transporting sediment. A large-scale laboratory was used to replicate realistic surfzone conditions in controlled tests, allowing for horizontal and vertical pressure gradient magnitudes and the resulting sediment bed response to be observed with precise instruments. Contrary to previous studies

  15. MEASURING THE STELLAR MASSES OF z ∼ 7 GALAXIES WITH THE SPITZER ULTRAFAINT SURVEY PROGRAM (SURFS UP)

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, R. E. Jr.; Casertano, S.; Stiavelli, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Gonzalez, A. H. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States); Lemaux, B. C. [Aix Marseille Université, CNRS, LAM (Laboratoire d' Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France); Bradač, M.; Cain, B.; Hall, N.; Huang, K.-H.; Lubin, L. [University of California, One Shields Avenue, Davis, CA 95616 (United States); Allen, S.; Von der Linden, A. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 452 Lomita Mall, Stanford, CA 94305-4085 (United States); Gladders, M. [Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Hildebradt, H.; Schrabback, T. [Argelander Institute for Astronomy, University of Bonn, Auf dem Hügel 71, D-53121 Bonn (Germany); Hinz, J.; Zaritsky, D. [Steward Observatory, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Treu, T., E-mail: rryan@stsci.edu [Department of Physics, University of California, Santa Barbara, CA 93106 (United States)

    2014-05-01

    We present Spitzer/IRAC observations of nine z'-band dropouts highly magnified (2 ≲ μ ≲ 12) by the Bullet Cluster. We combine archival imaging with our Exploratory program (SURFS UP), which results in a total integration time of ∼30 hr per Infrared Array Camera (IRAC) band. We detect (≳ 3σ) in both IRAC bands the brightest of these high-redshift galaxies, with [3.6] = 23.80 ± 0.28 mag, [4.5] = 23.78 ± 0.25 mag, and (H – [3.6]) = 1.17 ± 0.32 mag. The remaining eight galaxies are undetected to [3.6] ∼ 26.4 mag and [4.5] ∼ 26.0 mag with stellar masses of ∼5 × 10{sup 7} M {sub ☉}. The detected galaxy has an estimated magnification of μ = 12 ± 4, which implies this galaxy has an ultraviolet luminosity of L{sub 1500}∼0.3 L{sub z=7}{sup ∗}—the lowest-luminosity individual source detected in IRAC at z ≳ 7. By modeling the broadband photometry, we estimate the galaxy has an intrinsic star formation rate (SFR) of SFR ∼ 1.3 M {sub ☉} yr{sup –1} and stellar mass of M ∼ 2.0 × 10{sup 9} M {sub ☉}, which gives a specific star formation rate of sSFR ∼ 0.7 Gyr{sup –1}. If this galaxy had sustained this SFR since z ∼ 20, it could have formed the observed stellar mass (to within a factor of ∼2). We also discuss alternate star formation histories and argue that the exponentially increasing model is unlikely. Finally, based on the intrinsic SFR, we estimate that this galaxy has a likely [C II] flux of (f {sub [C} {sub II]}) = 1.6 mJy.

  16. PAISAJE, PATRIMONIO Y TURISMO DE SURF: FACTORES DE ATRACCIÓN Y MOTIVACIÓN EN EL «PARQUE NATURAL DEL ESTRECHO» (ESPAÑA

    Directory of Open Access Journals (Sweden)

    Manuel Rivera Mateos

    2016-01-01

    Full Text Available En este trabajo se estudia la incidencia de diversos factores geográficos, físico-ambien - tales, paisajísticos y socioculturales en la conformación y desarrollo de un destino especia - lizado en turismo deportivo de naturaleza y deportes acuáticos (win dsurf, surf, kite surf ...: Tarifa y el Parque Natural del Estrecho. Se realiza un análisis de los valores ambientales, climáticos, paisajísticos e histórico-culturales de los espacios que conforman su sistema de patrimonio territorial y que sirven de soporte y cualificación de las prácticas surferas, así como de la percepción de los mismos como factores competitivos y de atracción y sostenibi - lidad turísticas entre los agentes locales implicados en el desarrollo de estos deportes a partir de su propia experiencia y valoración.

  17. 骑浪横甩薄弱性衡准技术的发展%Development of Surf-riding Broaching Vulnerability Criteria Technology

    Institute of Scientific and Technical Information of China (English)

    唐哲

    2014-01-01

    This article introduces the physical background and the vulnerability criterion development process for the first layer and the second layer of surf-riding/broaching. Also it analyzes the preliminary criteria and the vulnerability criteria method for calculating of surf-riding/broaching. Mastering the development state of this technology can be useful for the research of relative area, and would become the base for the second general criteria technology.%介绍了骑浪/横甩的物理背景,以及骑浪/横甩第一层和第二层薄弱性衡准发展过程,并分析了骑浪横甩薄弱性衡准计算方法及初步衡准,掌握骑浪横甩薄弱性衡准技术的发展现状,有助于骑浪/横甩相关技术领域的研究,为船舶第二代完整稳性的技术发展奠定基础。

  18. SIFT和SURF在无人机影像匹配的对比研究%Comparative Study of SIFT and SURF in UAV Image Matching

    Institute of Scientific and Technical Information of China (English)

    罗亮; 熊助国

    2016-01-01

    The characteristics of the UAV image, in combination with the characteristics of SIFT and SURF operators, the two operators are com-pared in terms of feature extraction efficiency and feature extraction speed, according to the experiments on two kinds of operators in eval-uating the pros and cons of UAV image matching, the experiments show that SURF has a speed advantage, also in green vegetation cover surface can match is better than SIFT operator.%从无人机影像的特点考虑,结合SIFT和SURF算子的特点进行了两种算子在特征提取有效性、特征提取速度方面的比对,通过对两种算子在无人机影像匹配的实验中凸现的好坏做出评价,实验发现SURF的优势不仅仅在速度上,而且在绿色植被覆盖的地表下能匹配效果要优于SIFT算子。

  19. 基于SURF特征与模糊推理的掌纹识别%Palmprint recognition based on SURF features and fuzzy reasoning

    Institute of Scientific and Technical Information of China (English)

    陶筱娇; 王晅

    2016-01-01

    To alleviate the limitations that the existing palmprint recognition methods are time-consuming, and their robustness to the variations of orientation, position and illumination in capturing palmprint images is insufficient, this paper describes a new palmprint recognition method based on Speeded Up Robust Features(SURF)and fuzzy reasoning. The proposed method consists of two phases: enrolling phase and identification phase. In the enrolling phase, keypoints are detected with SURF from the enrolled palmprint images and mutually matched between training samples, and then for each enrolled user, the keypoints which matching frequencies exceed 50% are selected. For each selected keypoint, the matching rate, the mean and variance of the location coordinates and the mean of SURF descriptors in the enrolled palmprint images, the maximal distance between the mean and the SURF descriptors are determined and regarded as the user's palmprint patterns stored in a pattern library. In the identification phase, it utilizes SURF to detect keypoints from the palmprint image to be identified, and then the fuzzy matching degrees for all palmprint patterns in the library are calculated. A fussy reasoning approach is developed for matching. Experimental results demonstrate that the proposed method yields a better performance in terms of the correct classification percentages compared with the recent palmprint recognition algorithms. It is also shown that the proposed approach is robust to the variations of orientation, position and illumination, and yields observably low computational cost.%针对现有掌纹识别算法对掌纹图像在采集过程中的位置、方向、亮度变化缺乏足够的鲁棒性,而且计算复杂度较高的问题,提出了一种基于SURF描述字的掌纹识别算法.算法分为训练与识别两个过程,在训练过程中,提取属于同一类所有训练样本的SURF描述字进行互配,然后计算训练样本中互配

  20. Surfing a Standing Wave

    Science.gov (United States)

    de Campos Valadares, Eduardo; Alves, Esdras Garcia

    2005-05-01

    Local "reversal of gravity" can be simulated with an inverted pendulum whose pivot is made to oscillate vertically. A beautiful demonstration of this surprising effect can be found in Ref. 1. In this case, the pendulum is a piece of plastic straw and its pivot pin is fixed at the end of a plastic ruler that is made to oscillate vertically by a small eccentric motor. A theoretical treatment of this inverted pendulum may be found in Ref. 2.

  1. Surf Aces Resurfaced

    DEFF Research Database (Denmark)

    Carter, Dale

    2013-01-01

    The rise of the American counter-culture between the early- to mid-1960s and early- to mid-1970s was closely associated with the growth of environmentalism. This article explores how both informed popular music, a form of expression which during these years became not only a prominent form of ent...

  2. Surfing on a herringbone

    Science.gov (United States)

    Soto, Dan; Lagubeau, Guillaume; Clanet, Christophe; Quéré, David

    2016-05-01

    Evaporation of a liquid on a hot solid can be exploited to induce both levitation and self-propulsion if the vapor flow under the liquid is made directional. Here we propose to force an anisotropic flow of vapor with a herringbone pattern at a solid surface. Liquids are found to self-propel on such hot materials, drawn by the underlying flow of vapor. The simplicity of the geometry allows us to predict the direction of vapor flow rectification, to quantitatively model the propulsion, and to discuss how the pattern must be designed to optimize both driving force and drop velocity.

  3. Surfing a Black Hole

    Science.gov (United States)

    2002-10-01

    Star Orbiting Massive Milky Way Centre Approaches to within 17 Light-Hours [1] Summary An international team of astronomers [2], lead by researchers at the Max-Planck Institute for Extraterrestrial Physics (MPE) , has directly observed an otherwise normal star orbiting the supermassive black hole at the center of the Milky Way Galaxy. Ten years of painstaking measurements have been crowned by a series of unique images obtained by the Adaptive Optics (AO) NAOS-CONICA (NACO) instrument [3] on the 8.2-m VLT YEPUN telescope at the ESO Paranal Observatory. It turns out that earlier this year the star approached the central Black Hole to within 17 light-hours - only three times the distance between the Sun and planet Pluto - while travelling at no less than 5000 km/sec . Previous measurements of the velocities of stars near the center of the Milky Way and variable X-ray emission from this area have provided the strongest evidence so far of the existence of a central Black Hole in our home galaxy and, implicitly, that the dark mass concentrations seen in many nuclei of other galaxies probably are also supermassive black holes. However, it has not yet been possible to exclude several alternative configurations. In a break-through paper appearing in the research journal Nature on October 17th, 2002, the present team reports their exciting results, including high-resolution images that allow tracing two-thirds of the orbit of a star designated "S2" . It is currently the closest observable star to the compact radio source and massive black hole candidate "SgrA*" ("Sagittarius A") at the very center of the Milky Way. The orbital period is just over 15 years. The new measurements exclude with high confidence that the central dark mass consists of a cluster of unusual stars or elementary particles, and leave little doubt of the presence of a supermassive black hole at the centre of the galaxy in which we live . PR Photo 23a/02 : NACO image of the central region of the Milky Way . PR Photo 23b/02 : NACO image of the central region of the Milky Way (close-up) . PR Photo 23c/02 : Orbit of the star "S2" around the central Black Hole. PR Video Clip 02/02 : Motion of "S2" and other stars around the central Black Hole. Quasars and Black Holes Ever since the discovery of the quasars (quasi-stellar radio sources) in 1963, astrophysicists have searched for an explanation of the energy production in these most luminous objects in the Universe. Quasars reside at the centres of galaxies, and it is believed that the enormous energy emitted by these objects is due to matter falling onto a supermassive Black Hole, releasing gravitational energy through intense radiation before that material disappears forever into the hole (in physics terminology: "passes beyond the event horizon" [4]). To explain the prodigious energy production of quasars and other active galaxies, one needs to conjecture the presence of black holes with masses of one million to several billion times the mass of the Sun. Much evidence has been accumulating during the past years in support of the above "accreting black hole" model for quasars and other galaxies, including the detection of dark mass concentrations in their central regions. However, an unambiguous proof requires excluding all possible other, non-black hole configurations of the central mass concentration. For this, it is imperative to determine the shape of the gravitational field very close to the central object - and this is not possible for the distant quasars due to technological limitations of the currently available telescopes. The centre of the Milky Way ESO PR Photo 23a/02 ESO PR Photo 23a/02 [Preview - JPEG: 400 x 427 pix - 95k [Normal - JPEG: 800 x 853 pix - 488k] Caption : PR Photo 23a/02 is a reproduction of an image of the innermost area of the Milky Way, only a few light-years across, obtained in mid-2002 with the NACO instrument [3] at the 8.2-m VLT YEPUN telescope. It combines frames in three infrared wavebands between 1.6 and 3.5 µm. The compact objects are stars and their colours indicate their temperature (blue = "hot", red = "cool"). There is also diffuse infrared emission from interstellar dust between the stars. The two yellow arrows mark the position of the black hole candidate "SgrA*" at the very centre of the Milky Way galaxy. The scale is indicated; the 1 light-year bar subtends an angle of 8 arcsec in the sky. The centre of our Milky Way galaxy is located in the southern constallation Sagittarius (The Archer) and is "only" 26,000 light-years away [5]. On high-resolution images, it is possible to discern thousands of individual stars within the central, one light-year wide region (this corresponds to about one-quarter of the distance to "Proxima Centauri", the star nearest to the solar system). Using the motions of these stars to probe the gravitational field, observations with the 3.5-m New Technology Telescope (NTT) at the ESO La Silla Observatory (Chile) (and subsequently at the 10-m Keck telescope , Hawaii, USA) over the last decade have shown that a mass of about 3 million times that of the Sun is concentrated within a radius of only 10 light-days [5] of the compact radio and X-ray source SgrA* ("Sagittarius A") at the center of the star cluster. This means that SgrA* is the most likely counterpart of the putative black hole and, at the same time, it makes the Galactic Center the best piece of evidence for the existence of such supermassive black holes . However, those earlier investigations could not exclude several other, non-black hole configurations. "We then needed even sharper images to settle the issue of whether any configuration other than a black hole is possible and we counted on the ESO VLT telescope to provide those" , explains Reinhard Genzel , Director at the Max-Planck Institute for Extraterrestrial Physics (MPE) in Garching near Munich (Germany) and member of the present team. "The new NAOS-CONICA (NACO) instrument, built in a close collaboration between our institute, the Max-Planck Institute for Astronomy (MPIA: Heidelberg, Germany), ESO and the Paris-Meudon and Grenoble Observatories (France), was just what we needed to take this decisive step forward" . The NACO observations of the Milky Way centre ESO PR Photo 23b/02 ESO PR Photo 23b/02 [Preview - JPEG: 400 x 618 pix - 82k] [Normal - JPEG: 800 x 1236 pix - 456k] ESO PR Photo 23c/02 ESO PR Photo 23c/02 [Preview - JPEG: 486 x 400 pix - 78k] [Normal - JPEG: 971 x 800 pix - 352k] ESO PR Video Clip 02/02 [MPEG] ESO PR Video Clip 02/02 [MPEG Video; 533 k] Caption : PR Photo 23b/02 shows an infrared NACO image of a ~ 2 x 2 arcsec 2 area, centred on the position of the compact radio source "SgrA*" at the centre of the Milky Way Galaxy; it is marked by a small cross. The image was obtained in the K s -band at wavelength 2.1 µm in May 2002 and the angular resolution (image sharpness) is about 0.060 arcsec. At about the same time, the star designated "S2" came within 0.015 arcsec of the radio source. At the distance of the Milky Way Center, 1 arcsec on the sky corresponds to 46 light-days [5]; the bar is 20 light-days long (0.44 arcsec). In PR Photo 23c/02 , "SgrA*" and S2 are identified in the left panel. The right panel displays the orbit of S2 as observed between 1992 and 2002, relative to SgrA* (marked with a circle). The positions of S2 at the different epochs are indicated by crosses with the dates (expressed in fractions of the year) shown at each point. The size of the crosses indicates the measurement errors. The solid curve is the best-fitting elliptical orbit - one of the foci is at the position of SgrA* . The 2002 data points come from NACO observations done during the early commissioning, fine adjustement, and Science Verification phases for this instrument; these data were promptly made public through the ESO Archive, cf. the NACO data webpage. PR Video Clip 02/02 was produced by the Max-Planck-Society and shows the observed motions of S2 and other stars in this area. The new NACO instrument [3] was installed in late 2001 at the VLT 8.2-m YEPUN telescope. Already during the initial tests, it produced many impressive images, some of which have been the subject of earlier ESO press releases [6]. "The first observations this year with NACO gave us right away the sharpest and 'deepest' images of the Milky Way Centre ever taken, showing a large number of stars in that area in great detail" , says Andreas Eckart of the University of Cologne, another member of the international team that is headed by Rainer Schödel, Thomas Ott and Reinhard Genzel from MPE. "But we were still to be overwhelmed by the wonderful outcome of those data! " Combining their infrared images with high-resolution radio data, the team was able to determine - during a ten-year period - very accurate positions of about one thousand stars in the central area with respect to the compact radio source SgrA* , see PR Photo 23c/02 . "When we included the latest NACO data in our analysis in May 2002, we could not believe our eyes. The star S2 , which is the one currently closest to SgrA*, had just performed a rapid swing-by near the radio source. We suddenly realised that we were actually witnessing the motion of a star in orbit around the central black hole, taking it incredibly close to that mysterious object" , says a very happy Thomas Ott , who is now working in the MPE team on his PhD thesis. In orbit around the central black hole No event like this one has ever been recorded . These unique data show unambiguously that S2 is moving along an elliptical orbit with SgrA* at one focus, i.e. S2 orbits SgrA* like the Earth orbits the Sun, cf. the right panel of PR Photo 23c/02 . The superb data also allow a precise determination of the orbital parameters (shape, size, etc.). It turns out that S2 reached its closest distance to SgrA* in the spring of 2002, at which moment it was only 17 light-hours [5] away from the radio source, or just 3 times the Sun-Pluto distance. It was then moving at more than 5000 km/s, or nearly two hundred times the speed of the Earth in its orbit around the Sun. The orbital period is 15.2 years. The orbit is rather elongated - the eccentricity is 0.87 - indicating that S2 is about 10 light-days away from the central mass at the most distant orbital point [7]. "We are now able to demonstrate with certainty that SgrA* is indeed the location of the central dark mass we knew existed. Even more important, our new data have "shrunk" by a factor of several thousand the volume within which those several million solar masses are contained" , says Rainer Schödel , PhD student at MPE and also first author of the resulting paper. In fact, model calculations now indicate that the best estimate of the mass of the Black Hole at the centre of the Milky Way is 2.6 ± 0.2 million times the mass of the Sun . No other possibilities According to the detailed analysis presented in the Nature article, other previously possible configurations, such as very compact clusters of neutron stars, stellar size black holes or low mass stars, or even a ball of putative heavy neutrinos, can now be definitively excluded. The only still viable non-black hole configuration is a hypothetical star of heavy elementary particles called bosons, which would look very similar to a black hole. "However" , says Reinhard Genzel , "even if such a boson star is in principle possible, it would rapidly collapse into a supermassive black hole anyhow, so I think we have pretty much clinched the case!" Next observations "Most astrophysicists would accept that the new data provide compelling evidence that a supermassive black hole exists in the center of the Milky Way. This makes even more likely the supermassive black hole interpretation for the enormous concentration of dark mass detected at the center of many other galaxies" , says Alvio Renzini , VLT Programme Scientist at ESO. So what remains to be done? The next big quest now is to understand when and how these supermassive black holes formed and why almost every massive galaxy appears to contain one. The formation of central black holes and that of their host galaxies themselves increasingly appear to be just one problem and the same. Indeed, one of the outstanding challenges for the VLT to solve in the next few years. There is also little doubt that coming interferometric observations with instruments at the VLT Interferometer (VLTI) and the Large Binocular Telescope (LBT) will also result in another giant leap within this exciting field of research. Andreas Eckart is optimistic: "Perhaps it will even be possible with X-ray and radio observations in the next few years to directly demonstrate the existence of the event horizon." More information The information presented in this Press Release is based on a research article ("Seeing a Star Orbit around the Supermassive Black Hole at the centre of the Milky Way" by Rainer Schödel et al.) that appears in the research journal "Nature" on October 17, 2002. Notes [1]: This press release is issued in coordination between ESO and the Max-Planck-Institute for Extraterrestrial Physics (MPE) in Garching, Germany. A German version is available at http://www.mpg.de/pri02/pri0287.htm. [2]: The team consists of Rainer Schödel, Thomas Ott, Reinhard Genzel, Reiner Hofmann and Matt Lehnert (Max-Planck-Institut für extraterrestrische Physik, Garching, Germany), Andreas Eckart and Nelly Mouawad (Physikalisches Institut, Universität zu Köln, Cologne, Germany), Tal Alexander (The Weizmann Institute of Science, Rehovot, Israel), Mark J. Reid (Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass., USA), Rainer Lenzen and Markus Hartung (Max-Planck-Institut für Astronomie, Heidelberg, Germany), François Lacombe, Daniel Rouan, Eric Gendron and Gérard Rousset (Observatoire de Paris - Section de Meudon, France), Anne-Marie Lagrange (Laboratoire d'Astrophysique, Observatoire de Grenoble, France), Wolfgang Brandner, Nancy Ageorges, Chris Lidman, Alan F.M. Moorwood, Jason Spyromilio and Norbert Hubin (ESO) and Karl M. Menten (Max-Planck-Institut für Radioastronomie, Bonn, Germany). [3]: The NACO facility has two major components, CONICA and NAOS . The COudé Near-Infrared CAmera (CONICA) was developed by a German Consortium, with an extensive ESO collaboration. The Consortium consists of Max-Planck-Institut für Astronomie (MPIA) (Heidelberg) and the Max-Planck-Institut für Extraterrestrische Physik (MPE) (Garching). The Nasmyth Adaptive Optics System (NAOS) was developed, with the support of INSU-CNRS, by a French Consortium in collaboration with ESO. The French consortium consists of Office National d'Etudes et de Recherches Aérospatiales (ONERA) , Laboratoire d'Astrophysique de Grenoble (LAOG) and Observatoire de Paris (DESPA and DASGAL). [4]: In Albert Einstein's Theory of General Relativity, any mass has a characteristic radius, the "event horizon", or "Schwarzschild radius" named after the German astrophysicist Karl Schwarzschild . Within this radius, even light cannot escape the pull of the gravitational force. The radius for a 2.6 ± 0.2 million solar masses black hole (as the one at the centre of the Milky Way galaxy) is about 7.7 million km (26 light-seconds). [5]: Astronomical distances are often expressed in the time it takes the light, travelling at 300,000 km/sec, to cover them. 1 light-hour = 1.08 10 9 km; 1 light-day = 2.6 10 10 km; 1 light-month = 7.8 10 11 km; 1 light-year = 9.5 10 12 km. [6]: Earlier NACO images have been published in ESO PR 25/01 , ESO PR Photos 04a-c/02 , ESO PR Photos 19a-c/02 and ESO PR Photos 21a-c/02. [7]: S2 is an otherwise "normal" star, but some 15 times more massive and 7 times larger than the Sun. Its orbit around the Black Hole is comparatively stable. Even though it moves relatively close to the Black Hole in the present orbit, S2 would have to be at least 70 times closer (about 16 light-minutes from the Black Hole) before it would risk being disrupted by tidal forces. Astronomers refer to the extreme orbital points as "perenigricon" (closest to the Black Hole) and "aponigricon" (farthest away).

  4. Surfing China's National Defense

    Institute of Scientific and Technical Information of China (English)

    Ji Guilin

    2010-01-01

    @@ Following the start of its first test run on August 20, 2009, the website www.mod.gov.cn of the Ministry of National Defense (MOD) of the People's Republic of China has logged more than 2 billion hits,from many countries and regions including China, the United States,the United Kingdom, Japan, Australia and Singapore. China National Defense News reporters recently interviewed Ji Guilin, the website's Editor in Chief, on its performance and the feedback of netizens.

  5. Surf Aces Resurfaced

    DEFF Research Database (Denmark)

    Carter, Dale

    2013-01-01

    of entertainment but also a forum for cultural and social criticism. More particularly, through contextual and lyrical analyses of recordings by The Beach Boys, it identifies patterns of change and continuity in the articulation of counter-cultural, ecological and related sensibilities. During late 1966 and early......, what had formerly been considered high risk had by 1970 become good business as once-marginal environmentalism gained broader acceptability: thus did ‘America’s band’ articulate the flowering, greening and fading of the counter-culture.......The rise of the American counter-culture between the early- to mid-1960s and early- to mid-1970s was closely associated with the growth of environmentalism. This article explores how both informed popular music, a form of expression which during these years became not only a prominent form...

  6. MindSurf: a pilot study to assess the usability and acceptability of a smartphone app designed to promote contentment, wellbeing, and goal achievement.

    Science.gov (United States)

    Carey, Timothy A; Haviland, Jennifer; Tai, Sara J; Vanags, Thea; Mansell, Warren

    2016-12-12

    The Method of Levels (MOL) is a transdiagnostic cognitive therapy that promotes contentment, wellbeing, and goal achievement through the resolution of internal conflicts underlying psychological distress. MOL, based on Perceptual Control Theory (PCT), was developed in routine clinical practice and has been used effectively across different health services by different practitioners. Access to MOL-style questions through a smartphone app could, potentially, help both the general public maintain robust mental health, and also be a useful adjunct to therapy for clinical populations. The app is called MindSurf because of its focus on helping people explore their thinking. Prior to developing the app and using it with different populations it was necessary to determine whether such an idea would be usable for and acceptable to potential app users. Therefore, a pilot study was conducted with a non-clinical sample to assess the usability and acceptability of the app including monitoring whether the questions delivered in this way were associated with any adverse events. A pilot study using quantitative as well as qualitative methods and incorporating a repeated measures, A-B design was conducted. The 23 participants were healthy adult volunteers who were all either undergraduate students, postgraduate students, or staff of the University of Manchester. They received MOL-style questions on their mobile phones over a 1-week period. Qualitative results were encouraging and indicated that the format and style of questioning were acceptable to participants and did not lead to increased worry or concern. A one-way, repeated measures ANOVA indicated that there was a nonsignificant decrease in scores on the 21-item Depression, Anxiety, and Stress Scale (DASS21) over a 2 week period. The results of the pilot study justified development of MindSurf and further testing once it is available for use. A power analysis indicated that the pilot study was underpowered to detect

  7. Un hombre llamado pez: la historia de Duke Kahanamoku, el nadador más rápido del mundo y el padre del surf moderno. [A Man Called Fish: the History of Duke Kahanamoku, the fastest swimmer of the World and the father of modern surfing].

    Directory of Open Access Journals (Sweden)

    Daniel Esparza

    2014-10-01

    Full Text Available Duke Kahanamoku (1890-1968 forma parte del Salón de la Fama de la natación, y también del Salón de la Fama del surf. Es la única persona que tiene ese doble mérito. Las razones no son difíciles de entender: fue el nadador más rápido de entre los humanos hasta que llegó otro que no lo era: Tarzán, o mejor dicho, Johnny Weissmüller; y en cuanto al arte de montar las olas tuvo el mérito de expandir por otros mares y océanos esa actividad milenaria surgida en el Hawái arcaico hasta el punto de ser considerado por casi todos el padre del surf moderno. ¿Cuáles fueron sus éxitos en la natación? ¿Qué había de innovador en su técnica que le hizo el más rápido? ¿Cómo expandió el surf al mismo tiempo que realizaba exhibiciones de natación? ¿De qué energía carismática estaba dotado este hombre, que hasta el propio JFK en su visita a Honolulu en 1962 se saltó absolutamente todo el protocolo entre las autoridades norteamericanas para dirigirse directamente hacia él y saludarle efusivamente? He aquí su historia.

  8. Local Environment Recognition System Using Modified SURF-Based 3D Panoramic Environment Map for Obstacle Avoidance of a Humanoid Robot

    Directory of Open Access Journals (Sweden)

    Tae-Koo Kang

    2013-06-01

    Full Text Available This paper addresses a local environment recognition system for obstacle avoidance. In vision systems, obstacles that are located beyond the Field of View (FOV cannot be detected precisely. To deal with the FOV problem, we propose a 3D Panoramic Environment Map (PEM using a Modified SURF algorithm (MSURF. Moreover, in order to decide the avoidance direction and motion automatically, we also propose a Complexity Measure (CM and Fuzzy-Logic-based Avoidance Motion Selector (FL-AMS. The CM is utilized to decide an avoidance direction for obstacles. The avoidance motion is determined using FL-AMS, which considers environmental conditions such as the size of obstacles and available space. The proposed system is applied to a humanoid robot built by the authors. The results of the experiment show that the proposed method can be effectively applied to a practical environment.

  9. Preliminary assessment of surf-zone and estuarine line-fish species of the Dwesa-Cwebe Marine Protected Area, Eastern Cape, South Africa

    Directory of Open Access Journals (Sweden)

    Jan A. Venter

    2012-09-01

    Full Text Available A preliminary assessment of surf-zone and estuarine line fish was carried out in the DwesaCwebe Marine Protected Area (MPA, on the Wild Coast, South Africa. The purpose was to provide baseline data on inshore line-fish stocks in the MPA. A total of 28 species was recorded, of which 53% have a conservation status reflecting some concern and 43% are endemic to southern Africa. This highlights the value of the MPA for protection of important line-fish species. Within the MPA, localised differences were detected in species diversity, size frequency and catch per unit effort between unexploited and illegally exploited areas. These differences were more prominent in slow growing, long-lived species. It thus appears that illegal exploitation is negatively affecting fish populations within the MPA, which counteract and potentially could eliminate the benefits of fish protection typically associated with no-take MPAs. These results highlight the need for improved law enforcement and better communication with neighbouring communities to increase awareness. It is further recommended that the current no-take status of the MPA should be maintained. In addition, baseline fisheries information was collected on certain fish species that could be used to inform future conservation management of the MPA.Conservation implications: The Dwesa-Cwebe Marine Protected Area is unique and important for the conservation of key surf zone and estuarine fish species. However there is a significant risk to the fish populations due to illegal exploitation. Key interventions should include enhanced law enforcement but, more important, the creation of alternative livelihoods and long term sustainable benefits to local communities.

  10. Research on Sonar Image Registration and Fusion Based on SURF Algorithm%基于SURF的声纳图像配准与融合方法研究

    Institute of Scientific and Technical Information of China (English)

    郭军

    2013-01-01

    针对侧扫声纳图像分辨率高测深精度低而多波束声纳图像分辨率低测深精度高的特点,提出了一种基于SUFR的声纳图像自动配准与融合方法.该算法检测同一区域内侧扫声纳图像和多波束图像的特征点,通过最近邻匹配获得匹配点后,计算图像间的变换矩阵,利用空间变换完成配准,采用加权融合法实现两者的融合.实验结果表明该算法具有很好的鲁棒性,配准精度达到像素级,可实现两者的高精度自动配准与融合,取得了理想的效果.%According to multi - beam sonar system, the high - resolution backscatter but poor horizontal position accuracy, and side -scan sonar system, the accurate bathymetry and horizontal position but low resolution, the study is concerned with an automatic registration and fusion method of sonar image based on SURF. To achieve the integration of multi - beam sonar system and side - scan sonar system with the weighted fusion method, it extracts feature points by using SURF, computes transformation matrix by using match points, and performs registration and fusion with a spatial transform. The results indicate that this method is robust and stable with registration accuracy up to pixel level realizing the quite precise automatic registration and fusion, and is more suitable for sonar image.

  11. 改进SURF算法的图像拼接算法研究%An image stitching algorithm based on improved SURF algorithm

    Institute of Scientific and Technical Information of China (English)

    马林伟; 朱国魂

    2014-01-01

    针对目前图像拼接算法存在对于图像配准过程中对应特征点对难以准确匹配的问题,提出了一个通过改进的 SURF 算法提取图像特征点,然后对得到的特征点进行描述,利用快速RANSAC 算法配准图像,最后采用像素加权的方法进行图像融合。实验结果表明,提出的改进 SURF方法有效地提高了特征点提取的准确性,去除了错误的匹配点对,将整个拼接过程的效率从之前的13.03对/秒提升到15.20对/秒。%Image stitching is mainly used in aerial image processing, medical image analysis, virtual reality technology, computer vision, etc. For image registration, the difficult is to accurately extract the corresponding feature points. This paper puts forward a kind of algorithm based on improved SURF algorithm to extract image feature points, and then describes the feature points, using the RANSAC algorithm to registration the image. Finally, it uses the method of weighted pixel in image fusion. The experiment results show that this method improved the accuracy of feature extract, wipe out the wrong matching points, and improved the processing of stitching from 13.03/s to 15.20/s.

  12. 基于SIFT,PCA-SIFT和SURF特征检测方法的研究%Based on SIFT,PCA-SIFT and SURF Feature Detection Method Research

    Institute of Scientific and Technical Information of China (English)

    李宏荣; 李晓明

    2012-01-01

    To study features,we compared with SIFT(Scale Invariant Feature Transform),PCA-SIFT(Principal Component Analysis Scale Invariant Feature Transform)and SURF(Speeded Up Robust Features)three kinds of robust feature detection method.We use KNN(K-Nearest Neighbor)and random sampling method of these three kinds of methods for analysis.Where KNN used to seek matching pairs,random sampling for removing errors from match to match.Feature detection performance robustness is the image rotation,image blurring,illumination variation,the scale change of the image.The experimental evaluation is the use of repetition rate and the number of correct matching of the two statistical methods.In a variety of image transform in SIFT and SURF performance is consistent,but also has faster calculation speed.PCA-SIFT in the image rotation and illumination changes provides a better performance.%文章对SIFT,PCA-SIFT和SURF三种鲁棒性较强的特征检测方法作对比.文中运用KNN(K-Nearest Neighbor)和RANSAC的方法对这三种方法进行分析.其中KNN用于寻求匹配对,RANSAC用于从匹配对中剔除错误匹配.特征检测性能的鲁棒性主要是对图像旋转、图像模糊、光照变化、尺度变化下的图像进行测试.在各种图像变换中SIFT都体现出了稳定性,但计算速度相对比较慢.SURF不仅与SIFT的性能相一致,而且还拥有较快的计算速度.PCA-SIFT在图像旋转和光照变化中有较好的性能.

  13. A Research on Monocular Visual SLAM Based on SURF Feature%基于SURF特征的单目视觉SLAM方法研究∗

    Institute of Scientific and Technical Information of China (English)

    胡衡; 梁岚珍

    2015-01-01

    Because the visual information is easily affected by external environment factors, therefore the selected feature points of mobile robot based on visual simultaneous localization and map building requires high stability and good robustness. For the problem of monocular visual mobile robot SLAM(Simultaneous Localization and Mapping),a kind of mono-SLAM algorithm based on Extended kalman filter is proposed by using SURF(Speed Up Robust Features) feature points and the inverse depth method. The process of SLAM is completed by fusing the information of SURF features and robot information with EKF. The result of simulation experiment indicates that the proposed algorithm is feasible, and with high localization precision in indoor structured environment.%由于视觉信息很容易受到外界环境因素的影响,因此基于视觉的移动机器人同步定位与地图构建问题所选取的特征点要求具有较高的精确度和良好的鲁棒性。针对单目SLAM问题,提出一种基于扩展卡尔曼滤波器的单目视觉SLAM算法。该算法采用SURF特征点,结合反向深度估计法,应用扩展卡尔曼滤波器融合SURF特征信息与机器人位姿信息完成SLAM过程。仿真实验结果表明,在未知室内结构化环境下,该算法运行可靠,定位精度高。

  14. Time-of-flight secondary ion mass spectrometry (ToF-SIMS)-based analysis and imaging of polyethylene microplastics formation during sea surf simulation.

    Science.gov (United States)

    Jungnickel, H; Pund, R; Tentschert, J; Reichardt, P; Laux, P; Harbach, H; Luch, A

    2016-09-01

    Plastic particles smaller than 5mm, so called microplastics have the capability to accumulate in rivers, lakes and the marine environment and therefore have begun to be considered in eco-toxicology and human health risk assessment. Environmental microplastic contaminants may originate from consumer products like body wash, tooth pastes and cosmetic products, but also from degradation of plastic waste; they represent a potential but unpredictable threat to aquatic organisms and possibly also to humans. We investigated exemplarily for polyethylene (PE), the most abundant constituent of microplastic particles in the environment, whether such fragments could be produced from larger pellets (2mm×6mm). So far only few analytical methods exist to identify microplastic particles smaller than 10μm, especially no imaging mass spectrometry technique. We used at first time-of-flight secondary ion mass spectrometry (ToF-SIMS) for analysis and imaging of small PE-microplastic particles directly in the model system Ottawa sand during exposure to sea surf simulation. As a prerequisite, a method for identification of PE was established by identification of characteristic ions for PE out of an analysis of grinded polymer samples. The method was applied onto Ottawa sand in order to investigate the influence of simulated environmental conditions on particle transformation. A severe degradation of the primary PE pellet surface, associated with the transformation of larger particles into smaller ones already after 14days of sea surf simulation, was observed. Within the subsequent period of 14days to 1month of exposure the number of detected smallest-sized particles increased significantly (50%) while the second smallest fraction increased even further to 350%. Results were verified using artificially degraded PE pellets and Ottawa sand.

  15. Spatially constrained SURF feature point matching for UAV images%空间约束的无人机影像SURF特征点匹配

    Institute of Scientific and Technical Information of China (English)

    韩天庆; 赵银娣; 刘善磊; 白杨

    2013-01-01

    Compared with general scene images,unmanned aerial vehicle (UAV) images provide richer texture information,and often there are more serious problems for the one-to-many correspondence between local features and target objects.The traditional speeded-up robust features (SURF) algorithm would be inapplicable to UAV images.Therefore,an improved spatially constrained SURF method is proposed for UAV image matching and mosaicking.In the first feature point matching phase,SURF feature points are extracted from the whole base image and the blocks of the target image,respectively,a cosine-based spatial constraint relationship is built using the selected two pairs of points and imposed on the feature point dual matching process between the central block in the target image and the base image.In the second phase,the initial parameters of geometric transformation are calculated using the feature point points obtained in the first phase and used to estimate locations in the base image corresponding to points in the target image.For each feature point in the target image,point matching just need to be done within the neighborhood of the estimated locations so as to ensure matching efficiency and reliability.Meanwhile,uniformly distributed feature points are achieved with the constraint of point intensity.Finally,the obtained feature points are used for UAV image registration and mosaicking.The performance is compared with the manually selected points that are uniformly distributed.Experimental results illustrate the validity of the presented method.%与普通场景图像相比,无人机影像中纹理信息较丰富,局部特征与目标对象“一对多”的对应问题更加严重,经典SURF算法不适用于无人机影像的特征点匹配.为此,提出一种辅以空间约束的SURF特征点匹配方法,并应用于无人机影像拼接.该方法对基准影像整体提取SURF特征点,对目标影像分块提取SURF特征点,在特征点双向匹配过程中使用两特

  16. Image matching method based on image contrast enhancement of SURF%一种基于雾天图像增强的SURF图像匹配方法

    Institute of Scientific and Technical Information of China (English)

    李骥; 莫小锋; 王威; 杨蔚蔚

    2015-01-01

    In the geological disaster monitoring system, the image change detection can be used to monitor the occurred disaster. Image matching is needed to change detection accurately. Aiming at the problem of low matching precision with the image in the fog condition, an image matching method based on image contrast enhancement of SURF is proposed, enhanceing the matching precision of the fog image efficiently. It uses multi-scale Retinex algorithm to enhance the fog image, and then completes the extraction of feature points with SURF algorithm, uses Euclidean distance to measure the similarity of characteristic points, according to the similarity triangular distance ratio invariance, it deletes point pairs of mismatch. Experimental results show that the method significantly improves the precision of image feature points match-ing, provides a good foundation for subsequent use of image change detection for disaster monitoring.%在地质灾害监测系统中,可以通过图像的变化检测对发生的灾害进行监测。要精确地进行变化检测,需要首先对图像进行匹配。针对雾天图像匹配精度低的问题,提出了一种基于雾天图像增强的SURF(Speed Up Robust Feature)图像匹配方法,有效地提高了雾天图像的匹配精度。用MSR(Multi Scale Retinex)算法对雾天图像进行增强处理,采用SURF算法完成特征点的提取,用欧式距离来度量特征点的相似度,根据相似三角形的距离比例不变性删除误匹配的点对。实验结果表明,该方法显著提高了图像特征点的匹配精度,为后续利用图像变化检测进行灾害监测提供了良好的基础。

  17. Implementation of the vortex force formalism in the coupled ocean-atmosphere-wave-sediment transport (COAWST) modeling system for inner shelf and surf zone applications

    Science.gov (United States)

    Kumar, Nirnimesh; Voulgaris, George; Warner, John C.; Olabarrieta, Maitane

    2012-01-01

    The coupled ocean-atmosphere-wave-sediment transport modeling system (COAWST) enables simulations that integrate oceanic, atmospheric, wave and morphological processes in the coastal ocean. Within the modeling system, the three-dimensional ocean circulation module (ROMS) is coupled with the wave generation and propagation model (SWAN) to allow full integration of the effect of waves on circulation and vice versa. The existing wave-current coupling component utilizes a depth dependent radiation stress approach. In here we present a new approach that uses the vortex force formalism. The formulation adopted and the various parameterizations used in the model as well as their numerical implementation are presented in detail. The performance of the new system is examined through the presentation of four test cases. These include obliquely incident waves on a synthetic planar beach and a natural barred beach (DUCK' 94); normal incident waves on a nearshore barred morphology with rip channels; and wave-induced mean flows outside the surf zone at the Martha's Vineyard Coastal Observatory (MVCO).

  18. Spitzer UltRa Faint SUrvey Program (SURFS UP). II. IRAC-Detected Lyman-Break Galaxies at 6 < z < 10 Behind Strong-Lensing Clusters

    CERN Document Server

    Huang, Kuang-Han; Lemaux, Brian C; Ryan,, R E; Hoag, Austin; Castellano, Marco; AmorÍn, Ricardo; Fontana, Adriano; Brammer, Gabriel B; Cain, Benjamin; Lubin, L M; Merlin, Emiliano; Schmidt, Kasper B; Schrabback, Tim; Treu, Tommaso; Gonzalez, Anthony H; Von Der Linden, Anja; Knight, Robert I

    2015-01-01

    We study the stellar population properties of the IRAC-detected $6 \\lesssim z \\lesssim 10$ galaxy candidates from the Spitzer UltRa Faint SUrvey Program (SURFS UP). Using the Lyman Break selection technique, we find a total of 16 new galaxy candidates at $6 \\lesssim z \\lesssim 10$ with $S/N \\geq 3$ in at least one of the IRAC $3.6\\mu$m and $4.5\\mu$m bands. According to the best mass models available for the surveyed galaxy clusters, these IRAC-detected galaxy candidates are magnified by factors of $\\sim 1.2$--$5.5$. We find that the IRAC-detected $6 \\lesssim z \\lesssim 10$ sample is likely not a homogeneous galaxy population: some are relatively massive (stellar mass as high as $4 \\times 10^9\\,M_{\\odot}$) and evolved (age $\\lesssim 500$ Myr) galaxies, while others are less massive ($M_{\\text{stellar}}\\sim 10^8\\,M_{\\odot}$) and very young ($\\sim 10$ Myr) galaxies with strong nebular emission lines that boost their rest-frame optical fluxes. We identify two Ly$\\alpha$ emitters in our sample from the Keck DEIMOS...

  19. Modeling of Carrier-based Aircraft's Catapult Launch under Surf%有浪条件下舰载机弹射起飞建模研究

    Institute of Scientific and Technical Information of China (English)

    张磊; 王海峰; 宋笔锋

    2012-01-01

    有浪条件下,航空母舰的摇摆会影响舰载机的安全起飞.对有浪条件下舰载机弹射起飞过程受力、运动情况进行了分析.采用柔性起落架来实现航空母舰与舰载机之间的干涉,建立了模块化的仿真系统并研究了中等海况下航空母舰的摇摆对舰载机弹射起飞的影响.仿真结果表明,中等海况下纵摇是导致下沉的主要因素,最大下沉量可达15 m;横摇导致最大下沉约0.2m;垂荡导致最大下沉约1m;横摇会导致明显的横侧向运动;纵摇、横摇、垂荡均会导致起落架最大载荷显著增大.%The carrier' s swing can endanger the safety of carrier-based aircraft launching. The forces and motions during the carrier-based aircraft catapult launch under surf, adopted flexible gear model to achieve interaction between the carrier-based aircraft and the carrier are theoretically analyzed, founded a modularized simulation system and researched on the influence of carrier' s rocking on aircraft' s catapult launch. Simulation results show that under moderate sea conditions, the pitch is the main factor leading to the subsidence which can up to 15 meters while roll resulting about 0.2 m and heave resulting about 1 m in the maximum subsidence. Roll also leads to significant lateral movement. Pitch, roll and heave result are significantly increased in load of gear.

  20. The Multi-Scale Response of Water Quality, Biodiversity and Carbon Sequestration to Coupled Macronutrient Cycling from Source to Sea: TURF2SURF

    Science.gov (United States)

    Wade, Andrew; Emmett, Bridget; Jago, Colin; Stutter, Marc; Biggs, Jeremy

    2016-04-01

    Turf2Surf is a large, multi-disciplinary project that aims to test the hypothesis that the spatial and temporal patterns of water quality, C sequestration and biodiversity are better explained through the large-scale coupling of C, N and P cycles than by single cycle, single system approaches. To achieve this, a catchment-scale study of the River Conwy (349 km2) in Wales is being done with emphasis on determining when, where and how coupled macronutrient (C, N, P) cycling occurs in the biogeochemical hot-spots of the soils, the riparian zone, instream and in the river-estuarine transition zone. A major integrated measurement programme is now largely complete. New data are being analysed to understand which soil properties have greatest influence on above and below-ground productivity including plant traits and how microbial processing is controlled by stoichiometry and nutrient priming. Within the stream network, new understanding is being produced on the in-river algal and whole ecosystem (metabolic) response to CNP additions and the factors affecting the fate and cycling of organic matter. In the estuary, initial results indicate a subsurface jet is causing stratification and a velocity anomaly has been observed. Both are important in terms of suspended matter transport and floc break-up. An integrated model is being built to describe the soil-atmosphere-vegetation processes which is linked, firstly, to flow and water quality models that describe the CNP flux transport and transformations from the headwaters to the estuary and, secondly, to biodiversity models. The purpose of the integrated model is to quantify how coupled CNP cycles may respond to environmental change and thereby affect C sequestration, water quality and biodiversity in the future. The team are now in the major phase of data synthesis and model development and are interested in linking with similar studies involving coupled CNP cycles across the atmospheric

  1. Cigarette recognition system of feature fusion based on HALCON and SURF%基于HALCON与SURF的多特征融合条烟识别系统

    Institute of Scientific and Technical Information of China (English)

    刘镇; 张敏

    2015-01-01

    烟草物流中心工作量大,枯燥单一,导致分拣过程中经常出现多拿、少拿以及错拿等错误分拣现象,这极大的影响了分拣的效率,甚至导致一些不必要的损失。针对此现象,设计了一种基于HALCON与SURF的多特征融合条烟识别系统。不但提出了新的条烟图像特征描述方法,同时针对分拣生产线的特点,对识别策略进行了相应的改进设计。实验表明,此方案具有较好的应用前景。%Heavy and boring work in tobacco logistics center always makes workers make mistakes such as taking more or less, wrong sorting during their work, which not only adversely affect the efficiency of sorting work, and even cause losses which is evitable sometimes. Aiming at this phenomenon, a new system named cigarette recognition of feature fusion based on HALCON and SURF has been designed. In this article, some new methods to describe image features are put forward, meanwhile, recognition strategy has also been improved according to the characteristics of the sorting production line. Experimental results show that this scheme has a good application prospect.

  2. Molecular characterization of two kazal-type serine proteinase inhibitor genes in the surf clam Mesodesma donacium exposed to Vibrio anguillarum.

    Science.gov (United States)

    Maldonado-Aguayo, Waleska; Núñez-Acuña, Gustavo; Valenzuela-Muñoz, Valentina; Chávez-Mardones, Jacqueline; Gallardo-Escárate, Cristian

    2013-06-01

    This study reports two kazal-type serine protease inhibitors (KPI) identified in a cDNA library from the surf clam Mesodesma donacium, and characterized through Rapid Amplification of cDNA Ends (RACE). The KPIs, denoted as MdSPI-1 and MdSPI-2, presented full sequences of 1139 bp and 781 bp respectively. MdSPI-1 had a 5'untranslated region (UTR) of 175 bp, a 3'UTR of 283 bp and an open reading frame (ORF) of 681 pb that encodes for 227 amino acids. MdSPI-2 showed a 5'UTR of 70 bp, a 3'UTR of 279 bp and an ORF of 432 bp that encodes for 144 amino acids. Both sequences presented two kazal-type tandem domains. Phylogenetic analysis of MdSPI-1 and MdSPI-2 shows a main clade composed by other bivalve species and closely related crustaceans. Real time PCR analysis showed that MdSPI-1 is mainly up-regulated in mantle, foot, gills and muscle tissues, while MdSPI-2 is expressed principally in foot tissue. Moreover, to evaluate the immune response of MdSPI-1 and MdSPI-2, infections with Vibrio anguillarum were performed. Herein, MdSPI-1 and MdSPI-2 transcription expression were significantly up-regulated at 2 and 8 h post-challenge. Our results suggest that MdSPI-1 and MdSPI-2 are important humoral factors of innate immunity in M. donacium.

  3. Photo Surfing in Blade Runner

    Science.gov (United States)

    Ohler, Jason

    2005-01-01

    This month's "Mining Movies" looks at Blade Runner, Ridley Scott's film set in the year 2019. It is a sad time for Earth, which is in the midst of environmental degradation so severe that other planets are being prepared for colonization. The main source of labor for this preparation work are "replicants," organic robots that look and behave like…

  4. Atlantic Seaduck Project

    Science.gov (United States)

    Perry, M.C.; Hanson, Alan; Kerekes, Joseph; Paquet, Julie

    2006-01-01

    Atlantic Seaduck Project is being conducted to learn more about the breeding and moulting areas of seaducks in northern Canada and more about their feeding ecology on wintering areas, especially Chesapeake Bay. Satellite telemetry is being used to track surf scoters wintering in Chesapeake Bay, Maryland and black scoters on migrational staging areas in New Brunswick, Canada to breeding and moulting areas in northern Canada. Various techniques used to capture the scoters included mist netting, night-lighting, and net capture guns. All captured ducks were transported to a veterinary hospital where surgery was conducted following general anaesthesia procedures. A PTT100 transmitter (39 g) manufactured by Microwave, Inc., Columbia, Maryland was implanted into the duck?s abdominal cavity with an external (percutaneous) antenna. Eight of the surf scoters from Chesapeake Bay successfully migrated to possible breeding areas in Canada and all 13 of the black scoters migrated to suspected breeding areas. Ten of the 11 black scoter males migrated to James Bay presumably for moulting. Updated information from the ARGOS Systems aboard the NOAA satellites on scoter movements was made accessible on the Patuxent Website. Habitat cover types of locations using GIS (Geographical Information Systems) and aerial photographs (in conjunction with remote sensing software) are currently being analyzed to build thematic maps with varying cosmetic layer applications. Many factors related to human population increases have been implicated in causing changes in the distribution and abundance of wintering seaducks. Analyses of the gullet (oesophagus and proventriculus) and the gizzard of seaducks are currently being conducted to determine if changes from historical data have occurred. Scoters in the Bay feed predominantly on the hooked mussel and several species of clams. The long-tailed duck appears to select the gem clam in greater amounts than other seaducks, but exhibits a diverse diet of

  5. A Shoulder Surfing Resistant Graphical Passwords Scheme for Mobile Terminal%一种面向移动终端的抗肩窥图形密码方案

    Institute of Scientific and Technical Information of China (English)

    黄叶珏; 郑河荣

    2015-01-01

    Passwords authentication is still one of the main authentication modes for mobile terminal. Mobile terminal is vulnerable to shoulder surfing attack because of using in complex environments. Absorbing the design thought of adding interference graph from the pass-object graphical password scheme,a shoulder surfing resistant graphical passwords scheme for mobile terminal is proposed,in which the graphical passwords are generated by characters and colors. In the scheme,just by clicking the screen user can complete the whole log-in phase,the scheme design completely conforms to the use habit of touch type mobile terminal user. The security analysis shows that the scheme has good security in the password space and accidental login resistance,and can effectively resist the shoulder surfing attack in that the login process is recorded repeatedly.%密码认证目前仍然是移动终端主流身份认证方式之一。移动终端由于其使用环境的复杂性,密码容易遭受肩窥攻击。针对这种情况,文中吸取Pass-Object经典图形密码方案加入干扰图形的设计思想并加以改进,提出了一种面向移动终端的抗肩窥图形密码方案,方案以字符和颜色为基础生成图形密码。方案的设计完全符合触摸式移动终端用户的使用习惯,整个认证过程用户只需在触摸屏上点击即可完成操作。安全性分析数据表明:方案在密码空间和抗意外登陆方面都安全性良好,而且可有效抵御登陆过程被多次录制的肩窥攻击。

  6. Performance Characteristics of AOAC Method 2005.06 for the Determination of Paralytic Shellfish Toxins in Manila Clams, European Otter Clams, Grooved Carpet Shell Clams, Surf Clams, and Processed King Scallops.

    Science.gov (United States)

    O'Neill, Alison; Turner, Andrew D

    2015-01-01

    An approach was developed for the verification of method performance of the AOAC 2005.06 LC-fluorescence detector (FLD) method for determination of paralytic shellfish poisoning (PSP) toxins in bivalve shellfish. This was developed following advice published by the Analytical Laboratory Accreditation Criteria Committee and applied to shellfish species that had not been previously subjected to a full single-laboratory validation scheme. The refined approach was developed following the need to assess performance in a number of shellfish species infrequently monitored through the UK statutory monitoring program, while reducing the impact and cost of the studies, most notably in terms of the use of valuable reference standards. The species assessed were manila clams (Ruditapes philippinarum), European otter clams (Lutraria lutraria), grooved carpet shell clams (R. decussatus), surf clams (Spisula solida), and king scallops (Pecten maximus) presented as adductor only or adductor plus roe. The method was assessed for sensitivity in terms of LOD and LOQ, toxin recovery, and method precision in each species. It incorporated the PSP toxins deemed toxic and/or prevalent in UK samples and commercially available as certified reference standards. The toxins studied included GTX1-5, dcSTX, STX, C1&2, and NEO. The toxins dcGTX2&3 were included for surf clams due to the prevalence of these toxins in this species as a result of toxin decarbamoylation. Method performance targets were met for each of the characteristics investigated. Consequently, the method was deemed fit for purpose for the screening and quantification of these clam and scallop species for PSP toxins by AOAC Method 2005.06 LC-FLD.

  7. Kinetic double-layer model of aerosol surface chemistry and gas-particle interactions (K2-SURF): Degradation of polycyclic aromatic hydrocarbons exposed to O3, NO2, H2O, OH and NO3

    Science.gov (United States)

    Shiraiwa, Manabu; Garland, Rebecca M.; Pöschl, Ulrich

    2010-05-01

    We present a kinetic double-layer surface model (K2-SURF) that describes the degradation of polycyclic aromatic hydrocarbons (PAHs) on aerosol particles exposed to ozone, nitrogen dioxide, water vapor, hydroxyl and nitrate radicals [1]. The model is based on multiple experimental studies of PAH degradation and on the Pöschl-Rudich-Ammann (PRA) framework [2] for aerosol and cloud surface chemistry and gas-particle interactions. For a wide range of substrates, including solid and liquid organic and inorganic substances (soot, silica, sodium chloride, octanol/decanol, organic acids, etc.), the concentration- and time-dependence of the heterogeneous reaction between PAHs and O3 can be efficiently described with a Langmuir-Hinshelwood-type mechanism. Depending on the substrate material, the Langmuir adsorption constants for O3 vary over three orders of magnitude, and the second-order rate coefficients for the surface layer reaction of O3 with different PAH vary over two orders of magnitude. The available data indicate that the Langmuir adsorption constants for NO2 are similar to those of O3, while those of H2O are several orders of magnitude smaller. The desorption lifetimes and adsorption enthalpies suggest chemisorption of NO2 and O3 and physisorption of H2O. Note, however, that the exact reaction mechanisms, rate limiting steps and possible intermediates still remain to be resolved (e.g., surface diffusion and formation of O atoms or O3- ions at the surface). The K2-SURF model enables the calculation of ozone uptake coefficients, γO3, and of PAH concentrations in the quasi-static particle surface layer. Competitive adsorption and chemical transformation of the surface (aging) lead to a strong non-linear dependence of γO3 on time and gas phase composition, with different characteristics under dilute atmospheric and concentrated laboratory conditions. Under typical ambient conditions, γO3 of PAH-coated aerosol particles are expected to be in the range of 10-6 - 10

  8. Automatic registration of unmanned aerial vehicle images based on SURF operator%基于SURF算法的无人机航空图像自动配准研究

    Institute of Scientific and Technical Information of China (English)

    李二俊; 刘万林; 余涛; 谢东海; 蔡庆空

    2013-01-01

    针对实时性要求中SIFT特征配准算法耗时长的缺点,本文将SURF (Speeded Up Robust Feature,即加速鲁棒特征)算法应用于无人机航空图像的自动配准问题中.首先利用Hessian检测子检测特征点,再通过粗匹配和细匹配得到匹配点对,最后执行几何变换完成对图像的配准.通过与SIFT(Scale Invariant Feature Transform,即尺度不变特征变换)配准方法进行对比,结果表明SURF算法在满足精度的前提下具有比SIFT算法计算量小、速度快的优点,有一定的理论和应用价值.

  9. 基于SURF算法的绿色作物特征提取与图像匹配方法%Matching method of green crops based on SURF feature extraction

    Institute of Scientific and Technical Information of China (English)

    张志斌; 赵帅领; 罗锡文; 魏凤岐

    2015-01-01

    At present three-dimensional (3D) reconstruction of crop images and binocular vision guidance of agricultural robot are still important hot research contents in the related field, in which the feature extraction and matching of green crops is one of key technologies for monitoring crop growth state or providing 3D guiding information for agricultural robot because they directly affect the accuracy of obtained 3D information of crops. A feature extraction and matching method of the green crops is proposed in this paper. We focus on the crop regions in an image that can provide enough crop information. Firstly, a pre-treatment process of the image in RGB (red, green and blue) space is employed to segment the green crop from the backgrounds. Then the morphology opening operation with an optimal size is used to filter the noises including some isolated points or small areas caused by weeds, small stone, shadows and residue etc. Considering the field application conditions, the SURF is adopted to obtain the featuring points because of its attractive performance including repeatability, distinctiveness and robustness without bad time consumption. And the reason is that its detector and descriptor are scale invariance and rotation invariance with the length of 64 dimensions. There are 2 steps to get the featuring points: the first step is to employ Hessian matrix to detect the featuring points, and then, the non-maxima suppression is used to search the extreme points and the interpolation arithmetic is to position them; in the second step, the featuring points are extracted by using a main direction vector which is the main factor of the invariance property. Finally, the Euclidean distances between each searching points are calculated in the left and right image to measure the similarity of searching point pair. The ratio of the nearest distance to the sub-nearest is used to determine whether the point is the matching one or not. If the ratio is larger than the set

  10. Effects of ship traffic on seabirds in offshore waters: implications for marine conservation and spatial planning.

    Science.gov (United States)

    Schwemmer, Philipp; Mendel, Bettina; Sonntag, Nicole; Dierschke, Volker; Garthe, Stefan

    2011-07-01

    Most anthropogenic influences on marine ecosystems, except for river- or terrestrial-borne pollution, involve some sort of vessel activity. Increasing anthropogenic activities mean that many countries are being forced to develop spatial planning schemes, while at the same time implementing conservation sites for sensitive species at sea. The effects of ship traffic on seabirds sensitive to human disturbance are currently too poorly understood to allow for the development of proper planning and conservation guidelines. We therefore used aerial surveys and experimental disturbance to elucidate the effects of passing ships on the distribution patterns, habitat loss, and species-specific flight reactions of birds, as well as the potential for habituation. Loons (Gavia spp.) showed clear avoidance of areas with high shipping intensity. Flush distances of four sea duck species differed significantly, with the longest distances recorded for Common Scoters (Melanitta nigra) and the shortest for Common Eiders (Somateria mollissima). Flush distance was positively related to flock size. Among all the sea duck species studied, the duration of temporary habitat loss was longest for Common Scoters. We found indications of habituation in sea ducks within areas of channeled traffic. However, it is questionable if habituation to free-ranging ships is likely to occur, because of their unpredictable nature. We therefore recommend that spatial planning should aim to channel ship traffic wherever possible to avoid further habitat fragmentation and to allow for habituation, at least in some species. Information on the effects of shipping on other seabird species and during different periods of the year is urgently needed, together with information on the effects of different types of boats, including recreational and fishing vessels.

  11. Transformation of Waves Across the Surf Zone.

    Science.gov (United States)

    1981-03-01

    by -2 2 -2p(H) = 2H/Hrs exp(-H /Hrs) (1) where iH is the rms wave height.rms Using pressure records in the Gulf of Mexico , Longuet- Higgins (1975...Spring, MD 20910 21. Director 2 Instituto Oceanografico de la Armada Guayaquil, Ecuador 22. Director de Educacion de la Armada Comandancia General de

  12. Beach Nourishment and Artificial Surf Reef

    NARCIS (Netherlands)

    Klein, A.H.; De Menezes, J.T.; Sperb, R.S.; Siegle, E.; Fontura, R.; Van de Graaff, J.; Stive, M.J.F.; Van der Schrieck, G.L.M.; Verhagen, H.J.

    2004-01-01

    Balneário Camboriú is a very touristy city in southern Brazil, situated in the five kilometer wide Camboriú Bay. Its main tourist attraction is the beach, which is 5800 m long and rather narrow with a dry width of 10 to 20 m. The city is facing several problems regarding the beach that have a

  13. Suspended Sediments Measured in the Surf Zone.

    Science.gov (United States)

    1977-09-01

    described by Komar and Inman (1970). Sus- pended sediments were measured in situ by swimmers using a mechanical water sampling device which...PEÜüENC’-1 fH* 39 imt ^^m "/• ffr- 7 If) \\ h A /’ kl v \\ n/\\ i > ^ U, Vectra of onshore-offshore flow vs. nephelcmeter

  14. Stern Gerlach surfing in laser wakefield accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Flood, Stephen P. [Department of Physics, Lancaster University, Lancaster (United Kingdom); Cockcroft Institute of Accelerator Science and Technology, Daresbury (United Kingdom); Burton, David A., E-mail: d.burton@lancaster.ac.uk [Department of Physics, Lancaster University, Lancaster (United Kingdom); Cockcroft Institute of Accelerator Science and Technology, Daresbury (United Kingdom)

    2015-09-25

    We investigate the effects of a Stern–Gerlach-type addition to the Lorentz force on electrons in a laser wakefield accelerator. The Stern–Gerlach-type terms are found to generate a family of trajectories describing electrons that ‘surf’ along the plasma density wave driven by a laser pulse. Such trajectories could lead to an increase in the size of an electron bunch, which may have implications for attempts to exploit such bunches in future free electron lasers.

  15. Beach Nourishment and Artificial Surf Reef

    NARCIS (Netherlands)

    Klein, A.H.; De Menezes, J.T.; Sperb, R.S.; Siegle, E.; Fontura, R.; Van de Graaff, J.; Stive, M.J.F.; Van der Schrieck, G.L.M.; Verhagen, H.J.

    2004-01-01

    Balneário Camboriú is a very touristy city in southern Brazil, situated in the five kilometer wide Camboriú Bay. Its main tourist attraction is the beach, which is 5800 m long and rather narrow with a dry width of 10 to 20 m. The city is facing several problems regarding the beach that have a negati

  16. Color Invariant SURF in Discriminative Object Tracking

    NARCIS (Netherlands)

    Chu, D.M.; Smeulders, A.W.M.

    2012-01-01

    Tracking can be seen as an online learning problem, where the focus is on discriminating object from background. From this point of view, features play a key role as the tracking accuracy depends on how well the feature distinguish object and background. Current discriminative trackers use tradition

  17. Surf-zone Underwater Robotic Demonstration Platform

    Science.gov (United States)

    2014-01-01

    dynamically advantageous shape for a robotic system. To address locomotive factors ARA completed a research and technical study based on an Archimedes ...effective hull shape. To study mobility and traction a propulsion system based on an Archimedes screw drive was used. A drive design based on an... Archimedes screw was chosen because of its ability to operate in various mediums with varying flow rates. A test bed was designed and assembled in order to

  18. Surfing on the South Korean Wave!

    Institute of Scientific and Technical Information of China (English)

    Yang Wei

    2007-01-01

    @@ Have you ever watched this South Korean soap opera,Dae Jang Geum?That beautiful and tender girl with strong determination and indomitable spirit walked from ancient Korea into modern World through the program.

  19. Beach Nourishment and Artificial Surf Reef

    NARCIS (Netherlands)

    Klein, A.H.; De Menezes, J.T.; Sperb, R.S.; Siegle, E.; Fontura, R.; Van de Graaff, J.; Stive, M.J.F.; Van der Schrieck, G.L.M.; Verhagen, H.J.

    2004-01-01

    Balneário Camboriú is a very touristy city in southern Brazil, situated in the five kilometer wide Camboriú Bay. Its main tourist attraction is the beach, which is 5800 m long and rather narrow with a dry width of 10 to 20 m. The city is facing several problems regarding the beach that have a negati

  20. Color Invariant SURF in Discriminative Object Tracking

    NARCIS (Netherlands)

    D.M. Chu; A.W.M. Smeulders

    2010-01-01

    Tracking can be seen as an online learning problem, where the focus is on discriminating object from background. From this point of view, features play a key role as the tracking accuracy depends on how well the feature distinguish object and background. Current discriminative trackers use tradition

  1. Shotgun metagenomic data streams: surfing without fear

    Energy Technology Data Exchange (ETDEWEB)

    Berendzen, Joel R [Los Alamos National Laboratory

    2010-12-06

    Timely information about bio-threat prevalence, consequence, propagation, attribution, and mitigation is needed to support decision-making, both routinely and in a crisis. One DNA sequencer can stream 25 Gbp of information per day, but sampling strategies and analysis techniques are needed to turn raw sequencing power into actionable knowledge. Shotgun metagenomics can enable biosurveillance at the level of a single city, hospital, or airplane. Metagenomics characterizes viruses and bacteria from complex environments such as soil, air filters, or sewage. Unlike targeted-primer-based sequencing, shotgun methods are not blind to sequences that are truly novel, and they can measure absolute prevalence. Shotgun metagenomic sampling can be non-invasive, efficient, and inexpensive while being informative. We have developed analysis techniques for shotgun metagenomic sequencing that rely upon phylogenetic signature patterns. They work by indexing local sequence patterns in a manner similar to web search engines. Our methods are laptop-fast and favorable scaling properties ensure they will be sustainable as sequencing methods grow. We show examples of application to soil metagenomic samples.

  2. Smooth Particle Hydrodynamics for Surf Zone Waves

    Science.gov (United States)

    2009-01-01

    2010.) The GPU-SPHysics code, initiated by Dr. Alexis Hérault at the Istituto Nazionale di Geofisica e Vulcanologia in Sicily, has been applied to... Geofisica e Vulcanologia, sezione di Catania, for the development of GPU-SPHysics. Drs. Hérault and Bilotta were in residence at JHU during January of

  3. Surfing China’s National Defense

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Following the start of its first test run on August 20, 2009, the website www.mod.gov.cn of the Ministry of National Defense (MOD) of the People’s Republic of China has logged more than 2 billion hits, from many countries and regions including China, the United States, the United Kingdom, Japan, Australia and Singapore. China National Defense News reporters recently interviewed Ji Guilin, the website’s Editor in Chief, on its performance and the feedback of netizens.

  4. Pacific Continental Shelf Environmental Assessment (PaCSEA): aerial seabird and marine mammal surveys off northern California, Oregon, and Washington, 2011-2012

    Science.gov (United States)

    Adams, Josh; Felis, Jonathan J.; Mason, John W.; Takekawa, John Y.

    2014-01-01

    counted (19,033) with Common Murres (Uria aalge) representing the majority of individuals counted (70.4% of total). The remaining six most abundant taxa included: Surf/White-winged Scoters (Melanitta perspicillata/M. fusca; 4.8% of total), Herring/Thayer’s Gulls (Larus argentatus/L. thayeri; 3.8% of total), Cassin’s Auklets (Ptychoramphus aleuticus; 3.8% of total), Glaucous-winged Gulls (Larus glaucescens; 3.7% of total), Black-legged Kittiwakes (Rissa tridactyla; 2.0% of total), and Western Gulls (Larus occidentalis; 1.9% of total). During summer, five species comprised >95% of the total number of birds counted (17,063) with the majority comprised of Common Murres (54.1% of total) and Sooty Shearwaters (Puffinus griseus; 34.4% of total). The remaining most abundant three taxa included: Fork-tailed Storm-Petrels (Oceanodroma furcata; 3.3% of total), Western Gulls (2.1% of total), and Leach’s Storm-Petrels (Oceanodroma leucorhoa; 1.1% of total). During fall, nine species comprised >85% of the total number of birds counted (23,376) with the majority comprised of Common Murres (50.0% of total) and Sooty Shearwaters (10.5% of total). The remaining seven taxa included Cassin’s Auklets (5.2% of total), Surf/White-winged Scoters (5.1% of total), Fork-tailed Storm-Petrels (3.8% of total), Red/Red-necked Phalaropes (Phalaropus fulicarius/P. lobatus; 3.2% of total), California Gulls (Larus californicus; 3.1% of total), Northern Fulmars (Fulmarus glacialis; 2.7% of total), and Sabine’s Gulls (Xema sabini; 2.2% of total). Throughout the entire PaCSEA survey area, average densities (± SE) at sea for all marine birds combined were similar between fall (23.7 ± 1.9 birds km-2) and winter (24.0 ± 1.9 birds km-2) and least during summer (16.3 ± 2.2 birds km-2). Marine bird densities at sea varied according to bathymetric domain and season. Throughout the entire PaCSEA study area average densities (± SE) for all marine birds combined were greatest over the inner-shelf domain

  5. Species richness and distributions of boreal waterbirds in relation to nesting and brood-rearing habitats

    Science.gov (United States)

    Lewis, Tyler L.; Lindberg, Mark S.; Schmutz, Joel A.; Bertram, Mark R.; Dubour, Adam J.

    2015-01-01

    Identification of ecological factors that drive animal distributions allows us to understand why distributions vary temporally and spatially, and to develop models to predict future changes to populations–vital tools for effective wildlife management and conservation. For waterbird broods in the boreal forest, distributions are likely driven by factors affecting quality of nesting and brood-rearing habitats, and the influence of these factors may extend beyond singles species, affecting the entire waterbird community. We used occupancy models to assess factors influencing species richness of waterbird broods on 72 boreal lakes, along with brood distributions of 3 species of conservation concern: lesser scaup (Aythya affinis), white-winged scoters (Melanitta fusca), and horned grebe (Podiceps auritus). Factors examined included abundance of invertebrate foods (Amphipoda, Diptera, Gastropoda, Hemiptera, Odonata), physical lake attributes (lake area, emergent vegetation), water chemistry (nitrogen, phosphorus, chlorophyll a concentrations), and nesting habitats (water edge, non-forest cover). Of the 5 invertebrates, only amphipod density was related to richness and occupancy, consistently having a large and positive relationship. Despite this importance to waterbirds, amphipods were the most patchily distributed invertebrate, with 17% of the study lakes containing 70% of collected amphipods. Lake area was the only other covariate that strongly and positively influenced species richness and occupancy of scaup, scoters, and grebes. All 3 water chemistry covariates, which provided alternative measures of lake productivity, were positively related to species richness but had little effect on scaup, scoter, and grebe occupancy. Conversely, emergent vegetation was negatively related to richness, reflecting avoidance of overgrown lakes by broods. Finally, nesting habitats had no influence on richness and occupancy, indicating that, at a broad spatial scale, brood

  6. Ecomorphology and food habits of teleost fishes Trachinotus carolinus (Teleostei: Carangidae and Menticirrhus littoralis (Teleostei: Sciaenidae, inhabiting the surf zone off Niterói, Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Luana Prestrelo Palmeira

    2010-01-01

    Full Text Available The ecomorphology and food habits of juvenile Trachinotus carolinus and Menticirrhus littoralis caught in the surf zone of sandy beaches in Niterói, RJ, were investigated between July 2006 and May 2007. These fish species differ morphologically, but present similarities in their diet composition suggest some slight overlapping in their diet. The importance of food items was assessed using Kawakami and Vazzoler's feeding index. Morphometric variables were recorded to correlate with the diet composition of the different size classes for each species. A total of 210 fishes (Trachinotus carolinus - 122, Menticirrhus littoralis - 88, ranging between 24.2 mm and 112 mm total length, were analyzed, but the stomachs of only 84.8% of them contained food. Trachinotus carolinus presented mysids, Polychaetes and Emerita spp. as the predominant items in their diet. Formicidae and Isopoda were the most important items for class I individuals, whereas mysids and Emerita spp. were important for classes II and III. Class I individuals also showed smaller sized prey (amphipods and isopods and clupeid fish larvae in their diet. Emerita spp. dominated the food items of Menticirrhus littoralis regardless of the size class. Polychaetes, the second most important item was better represented in class sizes II and III. The main morphometric variable correlated with such differences included mouth position and diameter of the eye.A ecomorfologia e os hábitos alimentares de juvenis de Trachinotus carolinus e Menticirrhus littoralis capturados na zona de arrebentação de praias arenosas em Niterói, RJ, foram investigados entre julho de 2006 e Maio de 2007. Ambas as espécies diferem morfologicamente, mas apresentam semelhanças em sua dieta, sugerindo uma possível sobreposição alimentar. A importância dos itens alimentares foi avaliada utilizando o índice alimentar de Kawakami e Vazzoler. Variáveis morfométricas foram correlacionadas à dieta observada para

  7. Bioaccumulation of polonium 210Po in marine birds.

    Science.gov (United States)

    Skwarzec, B; Fabisiak, J

    2007-01-01

    The aim of this work was to determine the 210Po content in marine birds which permanently or temporally live in the Polish part of the Baltic Sea. We chose 11 species of sea birds: three species permanently residing at southern Baltic Sea, four species of wintering birds and three species of migrating birds. The results show that the polonium is non-uniformly distributed in the marine birds. The highest activities of 210Po were observed in feathers, muscles and liver and the lowest in skin and skeleton. Species of birds that eat crustaceans, molluscs, fish and plants (long-tailed duck Clangula hyemalis, white-winged scoter Melanitta fusca) accumulated more polonium than species that eat mainly fish (great cormorant Phalacrocorax carbo, common guillemot Uria aalge) or plants (tufted duck Aythya fuligula). Moreover, about 63% of the 210Po that was located in feathers of razorbil (Alca torda) and long-tailed duck (C. hyemalis) was apparently adsorbed, suggesting an external source such as the air. It means that the adsorption of 210Po on the feather surface may be an important transfer from air to water.

  8. Bioaccumulation of polonium {sup 210}Po in marine birds

    Energy Technology Data Exchange (ETDEWEB)

    Skwarzec, B. [University of Gdansk, Faculty of Chemistry, Chair of Analytical Chemistry, ul. Sobieskiego 18/19, 80-952 Gdansk (Poland)]. E-mail: bosk@chemik.chem.univ.gda.pl; Fabisiak, J. [Naval Academy, Smidowicza 61, 81-103 Gdynia (Poland)

    2007-07-01

    The aim of this work was to determine the {sup 210}Po content in marine birds which permanently or temporally live in the Polish part of the Baltic Sea. We chose 11 species of sea birds: three species permanently residing at southern Baltic Sea, four species of wintering birds and three species of migrating birds. The results show that the polonium is non-uniformly distributed in the marine birds. The highest activities of {sup 210}Po were observed in feathers, muscles and liver and the lowest in skin and skeleton. Species of birds that eat crustaceans, molluscs, fish and plants (long-tailed duck Clangula hyemalis, white-winged scoter Melanitta fusca) accumulated more polonium than species that eat mainly fish (great cormorant Phalacrocorax carbo, common guillemot Uria aalge) or plants (tufted duck Aythya fuligula). Moreover, about 63% of the {sup 210}Po that was located in feathers of razorbil (Alca torda) and long-tailed duck (C. hyemalis) was apparently adsorbed, suggesting an external source such as the air. It means that the adsorption of {sup 210}Po on the feather surface may be an important transfer from air to water.

  9. Influence of abiotic factors on spatiotemporal patterns of larval fish assemblages in the surf zones of the Yangtze River estuary and Hangzhou Bay%长江口和杭州湾碎波带仔稚鱼群聚时空分布特征及相关环境因子分析

    Institute of Scientific and Technical Information of China (English)

    陈渊戈; 毛成责; 林楠; 钟俊生; 徐兆礼

    2015-01-01

    2009年8月至2010年8月每月大潮前后在长江口和杭州湾碎波带的12个站点采集仔稚鱼,共采集到仔稚鱼14907尾,隶属24科74种,主要优势种有刀鲚(Coilia nasus,47.84%)、普氏缰虾虎鱼(Amoya pflaumii,11.58%)、属(Hemiculter spp.,9.12%)、飘鱼属(Pseudolaubuca spp.,6.29%)、多鳞四指马鲅(Eleutheronema rhadinum,5.62%)。分析了碎波带仔稚鱼群聚的时空分布特征与水温、盐度、底质、地形等环境因子的关系。聚类和排序的结果显示,全年仔稚鱼群聚在时间序列上可分为4组,各组间存在明显的种类更替,出现的主要优势种分别是12月–翌年4月的乔氏新银鱼(Neosalanx jordani),5月的中国大银鱼(Protosalanx chinensis)、中国花鲈(Lateolabrax maculatus),6月–9月的刀鲚、普氏缰虾虎鱼、属、飘鱼属、多鳞四指马鲅,以及10月、11月的有明银鱼(Salanx ariakensis)。在空间梯度上可分为长江口碎波带站点和杭州湾碎波带站点两组,两组间相异性贡献度最高的种类是刀鲚和普氏缰虾虎鱼(>10%),多个组内的独有种类显示出不同生态类型鱼类仔稚鱼对碎波带栖息地的生境选择分化。CCA 结果显示,所选的5个环境因子中只有水温和盐度对仔稚鱼群聚整体的时空分布有显著影响,但是对整个时空分布特征的解释度并不算高,意味着还存在其他重要的影响因素,可能包括饵料生物、径流等。对主要种类在单种的尺度上进行了丰度时空分布与环境因子的 GAM 曲线拟合,发现底质和地形对特定种类的仔稚鱼的分布有显著影响。地形开阔平坦、底质为沙质的站点仔稚鱼种类和丰度都相对较多,如优势种中的飘鱼属种类、多鳞四指马鲅、日本须鳎(Paraplagusia japonica)等都倾向选择栖息在开阔平坦的沙质底站点。%The surf zone is an important habitat for larval organisms; in particular, a large amount of research has de-monstrated the utility of

  10. Assessing the impact of the Tunoe Knob wind park on sea ducks: the influence of food resources

    Energy Technology Data Exchange (ETDEWEB)

    Laursen, K.; Guillemette, M.; Kyed larsen, J.; Clausager, I.

    1999-02-01

    This study deals with the influence of benthos abundance when assessing the potential impact of a small wind park on wintering sea ducks. Using the Before-After-Control-Impact design, it was suggested in a recent study that the wind park provoked a decline in the abundance and a change in the distribution of common eiders Somateria mollissima and common scoters Melanitta nigra. However, the observed decline in sea duck abundance occurred concomitantly with a decline of benthic food supplies. We measured concomitant food and common eider abundance for a fourth year at Tunoe Knob to test the hypothesis that, if food abundance increases again, we should also observe an increase in duck abundance. The methods used in this study are similar to those applied in the aforementioned study. The results showed that the average number of common eiders increased considerably in 1997-98 (3,361 individuals) compared to 1996-97 (458), even surpassing the level observed during the baseline years in 1994-95 (1,821). A significant increase in the abundance of common scoters occurred in 1997-98 compared to 1995-96 and 1996-97, but not in relation to the baseline year. The abundance of food for sea ducks also increased in 1997-98 where the frequency of occurrence of most potential prey reached the level observed during the baseline year. The density of blue mussels, a preferred prey species, was 1,113 individuals m{sup -2} in 1997-98 compared to 11,111 individuals m{sup -2} during the baseline year and only 100 individuals m{sup -2} in 1996-97. Computations of the amount of food supply eaten by wintering common eiders suggest that, during the baseline year, prey were superabundant. This may explain why we observed a great abundance of common eiders in 1997-98 despite the fact that mussel abundance did not reach the level observed during the baseline year. Finally, the distribution of common eiders in 1997-98 on the study site as a whole was very similar to the distribution observed

  11. Baseline glucocorticoids are drivers of body mass gain in a diving seabird

    Science.gov (United States)

    Hennin, Holly; Berlin, Alicia; Love, Oliver P.

    2016-01-01

    Life-history trade-offs are influenced by variation in individual state, with individuals in better condition often completing life-history stages with greater success. Although resource accrual significantly impacts key life-history decisions such as the timing of reproduction, little is known about the underlying mechanisms driving resource accumulation. Baseline corticosterone (CORT, the primary avian glucocorticoid) mediates daily and seasonal energetics, responds to changes in food availability, and has been linked to foraging behavior, making it a strong potential driver of individual variation in resource accrual and deposition. Working with a captive colony of white-winged scoters (Melanitta fusca deglandi), we aimed to causally determine whether variation in baseline CORT drives individual body mass gains mediated through fattening rate (plasma triglycerides corrected for body mass). We implanted individuals with each of three treatment pellets to elevate CORT within a baseline range in a randomized order: control, low dose of CORT, high dose of CORT, then blood sampled and recorded body mass over a two-week period to track changes in baseline CORT, body mass, and fattening rates. The high CORT treatment significantly elevated levels of plasma hormone for a short period of time within the biologically relevant, baseline range for this species, but importantly did not inhibit the function of the HPA (hypothalamic–pituitary–adrenal) axis. Furthermore, an elevation in baseline CORT resulted in a consistent increase in body mass throughout the trial period compared to controls. This is some of the first empirical evidence demonstrating that elevations of baseline CORT within a biologically relevant range have a causal, direct, and positive influence on changes in body mass.

  12. An evaluation of marine bird population trends following the Exxon Valdez oil spill, Prince William Sound, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Lance, Brian K.; Irons, David B.; Kendall, Steven J. [US Fish and Wildlife Service, Migratory Bird Management, Anchorage, AK (United States); McDonald, Lyman L. [West Inc., Cheyenne, WY (United States)

    2001-04-01

    We examined post-spill trends (1989-1998) of marine bird populations in Prince William Sound (PWS) following the Exxon Valdez oil spill (EVOS) to evaluate recovery of injured taxa. Two criteria were employed. First, we examined population trends of injured taxa only in the oiled area of PWS using regression models. Second, we examined population trends of injured taxa in the oiled area relative to the unoiled area using homogeneity of the slopes tests. We considered a population recovering if there was a positive trend using either criteria. We considered a population not recovering if there was no trend using either criteria or a negative trend in the oiled area. A significant negative trend in the oiled area relative to the unoiled area was considered a continuing and increasing effect. Most taxa for which injury was previously demonstrated were not recovering and some taxa showed evidence of increasing effects nine years after the oil spill. Four taxa (loons Gavia spp, Harlequin Duck Histrionicus histrionicus, Bufflehead Bucephala spp, and North-western Crow Corvus caurinus) showed weak to very weak evidence of recovery. None of these taxa showed positive trends in both winter and summer. Nine taxa (grebes Podiceps spp, cormorants Phalacrocorax spp, Black Oystercatcher Haematopus bachmani, Mew Gull Larus canus, Glaucous-winged Gull Larus glaucescens, terns Sterna spp, murres Uria spp, Pigeon Guillemot Cepphus columba, and murrelets Brachyramphus spp) showed no evidence of recovery during summer or winter. Four taxa (scoters Melanitta spp, mergansers Mergus spp, goldeneyes Bucephala spp, and Black-legged Kittiwake Rissa tridactyla) showed evidence of continuing, increasing effects. We showed evidence of slow recovery, lack of recovery, and divergent population trends in many taxa which utilise shoreline and nearshore habitats where oil is likely to persist. Potential lingering spill effects and natural variability appear to be acting in concert in delaying

  13. Gut content analysis of Lake Michigan waterbirds in years with avian botulism type E mortality, 2010–2012

    Science.gov (United States)

    Essian, David A.; Chipault, Jennifer G.; Lafrancois, Brenda M.; Leonard, Jill B.K.

    2016-01-01

    Waterbird die-offs caused by Clostridium botulinum neurotoxin type E (BoNT/E) have occurred sporadically in the Great Lakes since the late 1960s, with a recent pulse starting in the late 1990s. In recent die-offs, round gobies (Neogobius melanostomus) have been implicated as vectors for the transfer of BoNT/E to fish-eating birds due to the round goby invasion history and their importance as prey. Dreissenid mussels (Dreissena spp.) are also potentially involved in BoNT/E transmission to birds and round gobies. We examined gut contents of waterbirds collected in Lake Michigan during die-offs in 2010–2012, and the gut contents of culled, presumably BoNT/E-free double-crested cormorants (Phalacrocorax auritus). Round gobies were found in 86% of the BoNT/E-positive individuals, 84% of the BoNT/E-negative birds, and 94% of the BoNT/E-free cormorants examined. Double-crested cormorants, ring-billed gulls (Larus delewarensis), and common loons (Gavia immer) consumed larger-sized round gobies than horned and red-necked grebes (Podiceps auritus and Podiceps grisegena), white-winged scoters (Melanitta deglandi), and long-tailed ducks (Clangula hymealis). Other common prey included dreissenid mussels, terrestrial insects, and alewives (Alosa pseudoharengus). Our data emphasize the importance of round gobies and mussels in diets of Lake Michigan waterbirds and suggest they may play a role in the transfer of BoNT/E to waterbirds; however, round gobies and mussels were found in BoNT/E-positive, -negative, and -free individuals, suggesting that other factors, such as alternative trophic pathways for toxin transfer, bird migratory timing and feeding locations, prey behavior, and individual physiological differences across birds may affect the likelihood that a bird will succumb to BoNT/E intoxication.

  14. From the Director: Surfing the Web for Health Information

    Science.gov (United States)

    ... authoritative health information from across the World Wide Web. Searching for Reliable Results Most Internet users first visit a search engine — like Google or Yahoo! — when seeking health information. ...

  15. Surfing the High Energy Output Branch of Nonlinear Energy Harvesters

    Science.gov (United States)

    Mallick, D.; Amann, A.; Roy, S.

    2016-11-01

    Hysteresis and multistability are fundamental phenomena of driven nonlinear oscillators, which, however, restrict many applications such as mechanical energy harvesting. We introduce an electrical control mechanism to switch from the low to the high energy output branch of a nonlinear energy harvester by exploiting the strong interplay between its electrical and mechanical degrees of freedom. This method improves the energy conversion efficiency over a wide bandwidth in a frequency-amplitude-varying environment using only a small energy budget. The underlying effect is independent of the device scale and the transduction method and is explained using a modified Duffing oscillator model.

  16. Generalized Set of Boussinesq equations for Surf Zone Region

    CERN Document Server

    Dutta, R

    2005-01-01

    In this report, generalized wave breaking equations are developed using three dimensional fully nonlinear extended Boussinesq equations to encompass rotational dynamics in wave breaking zone. The derivation for vorticity distributions are developed from Reynold based stress equations.

  17. Spitzer ultra faint survey program (surfs up). I. An overview

    Energy Technology Data Exchange (ETDEWEB)

    Bradač, Maruša; Huang, Kuang-Han; Cain, Benjamin; Hall, Nicholas; Lubin, Lori [Department of Physics, University of California, Davis, CA 95616 (United States); Ryan, Russell; Casertano, Stefano [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Lemaux, Brian C. [Aix Marseille Université, CNRS, LAM (Laboratoire d' Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France); Schrabback, Tim; Hildebrandt, Hendrik [Argelander-Institut für Astronomie, Auf Dem Hügel 71, D-53121 Bonn (Germany); Gonzalez, Anthony H. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States); Allen, Steve; Von der Linden, Anja [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 382 Via Pueblo Mall, Stanford, CA 94305-4060 (United States); Gladders, Mike [The University of Chicago, The Kavli Institute for Cosmological Physics, 933 East 56th Street, Chicago, IL 60637 (United States); Hinz, Joannah; Zaritsky, Dennis [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Treu, Tommaso, E-mail: marusa@physics.ucdavis.edu [Department of Physics, University of California, Santa Barbara, CA 93106 (United States)

    2014-04-20

    Spitzer UltRa Faint SUrvey Program is a joint Spitzer and Hubble Space Telescope Exploration Science program using 10 galaxy clusters as cosmic telescopes to study z ≳ 7 galaxies at intrinsically lower luminosities, enabled by gravitational lensing, than blank field surveys of the same exposure time. Our main goal is to measure stellar masses and ages of these galaxies, which are the most likely sources of the ionizing photons that drive reionization. Accurate knowledge of the star formation density and star formation history at this epoch is necessary to determine whether these galaxies indeed reionized the universe. Determination of the stellar masses and ages requires measuring rest-frame optical light, which only Spitzer can probe for sources at z ≳ 7, for a large enough sample of typical galaxies. Our program consists of 550 hr of Spitzer/IRAC imaging covering 10 galaxy clusters with very well-known mass distributions, making them extremely precise cosmic telescopes. We combine our data with archival observations to obtain mosaics with ∼30 hr exposure time in both 3.6 μm and 4.5 μm in the central 4' × 4' field and ∼15 hr in the flanking fields. This results in 3σ sensitivity limits of ∼26.6 and ∼26.2 AB magnitudes for the central field in the IRAC 3.6 and 4.5 μm bands, respectively. To illustrate the survey strategy and characteristics we introduce the sample, present the details of the data reduction and demonstrate that these data are sufficient for in-depth studies of z ≳ 7 sources (using a z = 9.5 galaxy behind MACS J1149.5+2223 as an example). For the first cluster of the survey (the Bullet Cluster) we have released all high-level data mosaics and IRAC empirical point-spread function models. In the future we plan to release these data products for the entire survey.

  18. Breaker turbulence and sediment suspension in the surf zone

    DEFF Research Database (Denmark)

    Aagaard, Troels; Hughes, Michael G

    2010-01-01

    Field measurements of fluid velocities and suspended sediment concentrations were used to investigate the relative role of coherent vortices (related to wave breaking) in suspended sediment dynamics. The measurements were obtained from a barred (intermediate-type) beach and the instrument rig was...... between the horizontal fluid velocity and vortex-induced sediment suspension for each of the wave types, which may contribute to an explanation of net offshore and onshore sediment transport observed during episodes of beach erosion and recovery, respectively....

  19. MedlinePlus Guide to Healthy Web Surfing

    Science.gov (United States)

    ... to-date. Beware of bias--What is the purpose? Who is providing the funding? Who pays for the site? Check to see if the site is supported by public funds, donations or by commercial advertising. Advertisements should be labeled. They should say "Advertisement" ...

  20. Dorsal finger texture recognition: Investigating fixed-length SURF

    DEFF Research Database (Denmark)

    Hartung, Daniel; Kückelhahn, Jesper

    2012-01-01

    , namely an equal error rate of 0.74%. Of the two explored approaches for fixed-length features creation, averaging the descriptor components proved the most successful, achieving an equal error rate of 11.72%. Potential run-time performance increases were discovered as a side-effect. Without changing...

  1. Sensors and Algorithms for an Unmanned Surf-Zone Robot

    Science.gov (United States)

    2015-12-01

    AXV TESIS - COMPLEMENTARY FILTER TEST % File writen by Oscar Garcia 24/08/15 clear all clc clf imu = fopen(’imucomp2.txt’,’r’); 178...IMU data fusion and filtering using a first order Kalman filter. % AXV TESIS - IMU KALMAN FILTER TEST % File writen by Oscar Garcia 30/08/15...AXV_IMU_EKF.m It performs IMU data fusion and filtering using an extended Kalman filter. % AXV TESIS - IMU EKF TEST % File writen by Oscar Garcia 30/08

  2. Tracking image features with PCA-SURF descriptors

    CSIR Research Space (South Africa)

    Pancham, A

    2015-05-01

    Full Text Available The tracking of moving points in image sequences requires unique features that can be easily distinguished. However, traditional feature descriptors are of high dimension, leading to larger storage requirement and slower computation. In this paper...

  3. Surfing for history: dental library and dental school websites.

    Science.gov (United States)

    Kreinbring, Mary

    2007-01-01

    Library and academic websites are among the most reliable Internet resources available today. Schools of all types use the Internet as a means of sharing information; and libraries provide broader access to their collections via the Web. For researchers seeking specific, authoritative resources on dental history, library and dental school websites are most helpful in identifying print and online resources, in describing manuscript collections, and in presenting a history of the host institution. A library site often can provide sufficient information online to eliminate the need for an in-person visit to the library. On the other hand, a library site may tantalize the historian with enough information on unique collections that a trip can be justified.

  4. Surfing wavy surfaces: Bacteria-surface interactions in flow

    Science.gov (United States)

    Miño, Gastón L.; Kantsler, Vasily; Stocker, Roman

    2014-11-01

    Complex processes occur when microbes interact with surfaces, from mixture enhancement and motion rectification to biofilm formation. Microbe-surface interactions frequently occur in flowing fluids, and flow has recently been shown to have itself unexpected consequences on the dynamics of motile microbes. Here we report on microfluidic experiments in which the interactions of Escherichia coli bacteria with wavy surfaces was quantified in the presence of fluid flow, a model system for naturally occurring topography of many real surfaces. We quantify surface interactions in terms of incident and scattering angles over a range of flow conditions, and compare results to the observations for a microchannel with straight walls.

  5. Surfing the past: digital learners in the history class

    NARCIS (Netherlands)

    Nyirubugara, O.

    2012-01-01

    This book discusses one of the most frequently discussed subjects in history education during the last two decades, namely how secondary school pupils use the World Wide Web for their learning activities. Based on two case studies in two Dutch schools, the book shows some ways in which the use of

  6. Surfing the Net. Creativity on the World Wide Web.

    Science.gov (United States)

    Berger, Sandra

    2001-01-01

    This article discusses how the World Wide Web can empower students to think creatively, especially the gifted. It profiles 3 Web sites that discuss techniques, games, and strategies for enhancing creative thinking and 13 Web sites that contain information on inventors and inventions to stimulate gifted students. (Contains one reference.) (CR)

  7. Effects of Surf Zone Sediment Properties on Shock Wave Behavior

    Science.gov (United States)

    2016-06-07

    to be a first order factor. In addition, modeling predictions require the compressibility of the sediments at high and low pressures . The objective...sands in a test tank and initiate shock waves with a high energy laser system. The results will be used to validate numercal model predictions of

  8. Surfing the free energy landscape of flavodoxin folding

    NARCIS (Netherlands)

    Bollen, Y.J.M.

    2004-01-01

    The research described in this thesis has been carried out to obtain a better understanding of the fundamental rules describing protein folding. Protein folding is the process in which a linear chain of amino acids contracts to a compact state in which it is active. Flavodoxin from Azotobacter vinel

  9. Performance of a Tilt Current Meter in the Surf Zone

    DEFF Research Database (Denmark)

    Hansen, Asger Bendix; Carstensen, Stefan; Christensen, Drude Fritzbøger

    2017-01-01

    Tilt Current Meters (TCM’s) are relatively simple and inexpensive instruments for measuring currents in rivers and inthe sea. Their low cost and easy deployment means that a relatively large number of TCM’s can be deployed comparedto more conventional current meters such as Acoustic Doppler...

  10. Sand transport processes in the surf and swash zones

    NARCIS (Netherlands)

    Zanden, van der Joep

    2016-01-01

    Long-term predictions of beach morphology using numerical models contribute to cost-effective coastal protection strategies. The physics of sand transport in the wave breaking region and the swash zone are not fully understood, leading to poor predictive capability of existing sand transport models

  11. Critical Surfing: Holocaust Denial and Credibility on the Web.

    Science.gov (United States)

    Borrowman, Shane

    1999-01-01

    Discusses the nature of hate speech in general, and Holocaust denial in particular, on the World Wide Web, citing specific Web sources. Argues that, although discussion of Holocaust denial may be a difficult classroom discussion topic, and should be approached carefully, intelligent use of the Internet must be taught in the classroom. (MSE)

  12. Surfing gravitational waves: can bigravity survive growing tensor modes?

    CERN Document Server

    Amendola, Luca; Martinelli, Matteo; Pettorino, Valeria; Zumalacarregui, Miguel

    2015-01-01

    The theory of bigravity offers one of the simplest possibilities to describe a massive graviton while having self-accelerating cosmological solutions without a cosmological constant. However, it has been shown recently that bigravity is affected by early-time fast growing modes on the tensor sector. Here we argue that we can only trust the linear analysis up to when perturbations are in the linear regime and use a cut-off to stop the growing of the metric perturbations. This analysis, although more consistent, still leads to growing tensor modes that are unacceptably large for the theory to be compatible with measurements of the cosmic microwave background (CMB), both in temperature and polarization spectra. In order to suppress the growing modes and make the model compatible with CMB spectra, we find it necessary to either fine-tune the initial conditions, modify the theory or set the cut-off for the tensor perturbations of the second metric much lower than unity. Initial conditions such that the growing mod...

  13. Surfing the Tsunami: Faculty Engagement with the Open Learning Initiative

    Science.gov (United States)

    Thille, Candace M.

    2013-01-01

    There are two major discussions emerging out of higher education. The first is the dual challenge of increasing completion rates and reducing the cost of instruction. The second is about the impact of technology on higher education, a topic brought to the fore in the past year by the Massive Open Online Course (MOOC) phenomenon. The Open Learning…

  14. Management of Surfing Injuries: A Plastic Surgeon's Viewpoint. Case Reports.

    Science.gov (United States)

    Rudolph, Ross

    1989-01-01

    Describes plastic surgery techniques used to irrigate, debride, and close lacerations caused by surfboards. Head lacerations and nose fractures are the most common injuries. According to a survey, lacerations may be deeper than expected from their surface appearance and wounds may contain surfboard fragments. Injury prevention is discussed. (SM)

  15. Surfing the past: digital learners in the history class

    NARCIS (Netherlands)

    Nyirubugara, O.

    2012-01-01

    This book discusses one of the most frequently discussed subjects in history education during the last two decades, namely how secondary school pupils use the World Wide Web for their learning activities. Based on two case studies in two Dutch schools, the book shows some ways in which the use of th

  16. Oscillatory infragravity wave contribution to surf zone sediment transport

    DEFF Research Database (Denmark)

    Aagaard, Troels; Greenwood, Brian

    2008-01-01

    can create a perturbation of the bar crest and/or generate a crescentic bar. These results provide support for the template model for crescentic bar formation, first proposed by Bowen and Inman (Bowen, A.J. and Inman, D.L., 1971. Edge waves and crescentic bars. J.Geophys.Res., 76, 8662-8670) although...

  17. Modeling, Simulation, and Testing of Surf Kites for Power Generation

    NARCIS (Netherlands)

    Williams, P.; Lansdorp, B.; Ruiterkamp, R.; Ockels, W.J.

    2008-01-01

    Non-powered flight vehicles such as kites can provide a means of transmitting wind energy from higher altitudes to the ground via tethers. At Delft University of Technology, construction and testing of such a high altitude wind machine is ongoing. The concept is called the Laddermill. It generates e

  18. Senior Surfing: Computer Use, Aging, and Formal Training

    Science.gov (United States)

    Warren-Peace, Paula; Parrish, Elaine; Peace, C. Brian; Xu, Jianzhong

    2008-01-01

    In this article, we describe data from two case studies of seniors (one younger senior and one older senior) in learning to use computers. The study combined interviews, observations, and documents to take a close look at their experiences with computers, as well as the influences of aging and computer training on their experiences. The study…

  19. Surfing the Tsunami: Faculty Engagement with the Open Learning Initiative

    Science.gov (United States)

    Thille, Candace M.

    2013-01-01

    There are two major discussions emerging out of higher education. The first is the dual challenge of increasing completion rates and reducing the cost of instruction. The second is about the impact of technology on higher education, a topic brought to the fore in the past year by the Massive Open Online Course (MOOC) phenomenon. The Open Learning…

  20. Surfing Peer-to-Peer IPTV: Distributed Channel Switching

    Science.gov (United States)

    Kermarrec, A.-M.; Le Merrer, E.; Liu, Y.; Simon, G.

    It is now common for IPTV systems attracting millions of users to be based on a peer-to-peer (P2P) architecture. In such systems, each channel is typically associated with one P2P overlay network connecting the users. This significantly enhances the user experience by relieving the source from dealing with all connections. Yet, the joining process resulting in a peer to be integrated in channel overlay usually requires a significant amount of time. As a consequence, switching from one channel to another is far to be as fast as in IPTV solutions provided by telco operators. In this paper, we tackle the issue of efficient channel switching in P2P IPTV system. This is to the best of our knowledge the first study on this topic. First, we conducted and analyzed a set of measurements of one of the most popular P2P systems (PPlive). These measurements reveal that the set of contacts that a joining peer receives from the central server are of the utmost importance in the start-up process. On those neigbors, depends the speed to acquire the first video frames to play. We then formulate the switching problem, and propose a simple distributed algorithm, as an illustration of the concept, which aims at leveraging the presence of peers in the network to fasten the switch process. The principle is that each peer maintains as neighbors peers involved in other channels, providing peers with good contacts upon channel switching. Finally, simulations show that our approach leads to substantial improvements on the channel switching time. As our algorithmic solution does not have any prerequisite on the overlays, it appears to be an appealing add-on for existing P2P IPTV systems.

  1. 基于鳃的 microRNA 转录组研究中国蛤蜊对重金属镉的响应%Identification and differential expression of gill microRNA in the Chinese surf clam (Mactra chinensis)with Cd2+ exposure

    Institute of Scientific and Technical Information of China (English)

    张晶晶; 李宏俊; 秦艳杰; 刘敏; 叶晟

    2016-01-01

    中国蛤蜊(Mactra chinensis )是一种重要的经济贝类,分布于我国的辽宁和山东。近年来,生境恶化和过度捕捞导致我国蛤蜊资源量减少。我们利用 Illumina Hiseq-2500平台对中国蛤蜊鳃的 microRNA 转录组进行测序,运用差异表达寻找对镉刺激有响应的功能 microRNA。结果显示对照组获得了14415256条 clean reads,实验组获得了15570111条 clean reads。在这些 reads 中一共存在14584077小 RNA,包括1898035条 unique 小 RNA,其中对照组和实验组共有187859条 unique 小 RNA。两个组的小 RNA 文库的片段长度分布是相似的,大部分小 RNA 长度分布在26~27 nt。在对照组文库中最丰富的片段长度是27 nt,其次是28 nt、26 nt 和23 nt。在实验组文库中,数量最丰富的片段长度是26 nt,其次是27 nt、28 nt 和23 nt。经过对序列前体以及结构特征的分析,发现这两个组中一共有50个 microRNA,其中已知的是38个,新发现的是12个。对照组和实验组 microRNA 含量最丰富的片段长度是23 nt。通过差异表达分析,5个 microRNA 基因具有显著性差异且从对照组到实验组的表达量是上调的,其余45个没有显著性的差异。把这50个序列与中国蛤蜊转录组进行比对,一共找到了542个靶基因。5个具有表达差异的基因一共比对到11个靶基因。把这11个靶基因与 NCBI 数据库比对,4个靶基因在 COG 中得到注释,1个靶基因在 GO 中得到注释,6个靶基因在 KEGG 中得到注释,11个靶基因在 nr 数据库中得到注释,注释到的基因有泛素蛋白连接酶 E3,Wnt 信号通路,G 蛋白信号调控等。%The Chinese surf clam (Mactra chinensis )is an economically important clam,distributed in Lia-oning Province and Shandong Province.In recently years,because of coastal environmental deterioration and overfishing,the natural population of M.chinensis have considerably declined

  2. pesticides distribution in surf ce w ters nd sediments of lotic nd lentic ...

    African Journals Online (AJOL)

    USER

    2016-12-12

    Dec 12, 2016 ... Faculty of Life Sciences, University of Benin, Benin City, P.M.B 1154, Edo State, Nigeria. Abstract ... concentrations of pesticides in the surface waters and sediments of lotic and lentic ..... foodstuff of animal origin in Nigeria.

  3. Surfing the web during pandemic flu: availability of World Health Organization recommendations on prevention

    Directory of Open Access Journals (Sweden)

    Ravà Lucilla

    2010-09-01

    Full Text Available Abstract Background People often search for information on influenza A(H1N1v prevention on the web. The extent to which information found on the Internet is consistent with recommendations issued by the World Health Organization is unknown. Methods We conducted a search for "swine flu" accessing 3 of the most popular search engines through different proxy servers located in 4 English-speaking countries (Australia, Canada, UK, USA. We explored each site resulting from the searches, up to 4 clicks starting from the search engine page, analyzing availability of World Health Organization recommendations for swine flu prevention. Results Information on hand cleaning was reported on 79% of the 147 websites analyzed; staying home when sick was reported on 77.5% of the websites; disposing tissues after sneezing on 75.5% of the websites. Availability of other recommendations was lower. The probability of finding preventative recommendations consistent with World Health Organization varied by country, type of website, and search engine. Conclusions Despite media coverage on H1N1 influenza, relevant information for prevention is not easily found on the web. Strategies to improve information delivery to the general public through this channel should be improved.

  4. Surfing for Social Studies Software: A Practical Guide to Locating and Selecting Resources on the Internet.

    Science.gov (United States)

    Foster, Stuart J.; Hoge, John

    1997-01-01

    Reviews a list of seven Web sites that provide extensive information on software available from educational agencies or companies specializing in media products. Recommends 15 social studies software programs covering a variety of topics including the Mayan civilization, Abraham Lincoln, and the Vietnam War. (MJP)

  5. MAGNETOUR: Surfing Planetary Systems on Electromagnetic and Multi-Body Gravity Fields Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a new mission concept, called MAGNETOUR, that enables a spacecraft to orbit and travel between multiple moons of an outer planet, using very little or...

  6. Aerosol Production in the Surf Zone and Effects on IR Extinction

    DEFF Research Database (Denmark)

    Neele, F. P.; Leeuw, G. de; Eijk, A. M. J. van;

    1998-01-01

    Paper presented at the RTO SET Symposium on E-O Propagation, Signature and System Performance Under Adverse Meteorological Conditions Considering Out-of-Area Operations, held at the Italian Air Force Academy, Naples, Italy, 16-19 March 1998....

  7. Video and Field Observations of Wave Attenuation in a Muddy Surf Zone

    Science.gov (United States)

    2011-01-01

    the Gulf of Mexico . These authors showed that during pre-frontal conditions when wave energy increases, sediment is resuspended, mixed and...shallow shelf, Gulf of Mexico . Continental Shelf Research 26, 2073-2091. Marques, W., 2009. Estudo da dinamica da pluma costeira da Lagoa dos Patos. Phd... Brasil . Pesquisas em Geociencias 20. 18-26. Vinzon, S., Meirelles. S.. Le3o. T.. 2008. Wave generated lutoclines offshore of Cassino Beach. Brazil

  8. A Temporal and Spatial Analysis of Wave-Generated Foam Patterns in the Surf Zone

    Science.gov (United States)

    2017-01-10

    tilted downward in the offshore direction (Nadaoka et al. 1989). Nadaoka et al. (1989) also observed that the ODEs can reach the bottom and are a...150 200 250 300 350 12 (outlined in black in Figure 4). It is necessary to use a search box because the UAV moves slightly with wind gusts. Each...approximately 0.25 to 0.64 meters. The areas are also consistent between the top boxes, which are located farther offshore , and the bottom boxes, which

  9. Avian vacuolar myelinopathy in the southeast: An ecoepidemiological assessment with emphasis on Lake Surf, North Carolina

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Between 2000 and 2005, the U.S. Fish and Wildlife Service (Service) and partners conducted an investigation of avian vacuolar myelinopathy (AVM), an unusual...

  10. Turning the tide or surfing the wave? Responsible Research and Innovation, fundamental rights and neoliberal virtues.

    Science.gov (United States)

    Arnaldi, Simone; Gorgoni, Guido

    2016-12-01

    The notion of Responsible Research and Innovation (RRI) has increasingly attracted attention in the academic literature. Up until now, however, the literature has focused on clarifying the principles for which research and innovation are responsible and on examining the conditions that account for managing them responsibly. Little attention has been reserved to exploring the political-economic context in which the notion of RRI has become progressively more prominent. This article tries to address this aspect and suggests some preliminary considerations on the connections between the specific understanding of responsibility in RRI and the framing of responsibility in what has been synthetically defined as 'neoliberalism'. To do so, we try to illustrate how the idea of responsibility has evolved over time so that the specific characteristics of RRI can be better highlighted. These characteristics will then be discussed against the features of neoliberalism and its understanding of responsibility. Eventually, we reaffirm a view of RRI centred on fundamental rights as a possible point of departure between these two perspectives on responsibility.

  11. How corporate clients and consumers surf the Internet: A review and future directions for research

    DEFF Research Database (Denmark)

    Gattiker, U.E.; Perlusz, S.; Bohmann, K.

    1999-01-01

    ) assessment of on-line information for different categories of products; (3) influence of people's technology resistance on beliefs and behaviours regarding on-line shopping; and (4), how these factors affect people's attempt to externalise costs (e.g., transaction costs) will be outlined. Few studies address...

  12. Surfing on Protein Waves: Proteophoresis as a Mechanism for Bacterial Genome Partitioning

    Science.gov (United States)

    Walter, J.-C.; Dorignac, J.; Lorman, V.; Rech, J.; Bouet, J.-Y.; Nollmann, M.; Palmeri, J.; Parmeggiani, A.; Geniet, F.

    2017-07-01

    Efficient bacterial chromosome segregation typically requires the coordinated action of a three-component machinery, fueled by adenosine triphosphate, called the partition complex. We present a phenomenological model accounting for the dynamic activity of this system that is also relevant for the physics of catalytic particles in active environments. The model is obtained by coupling simple linear reaction-diffusion equations with a proteophoresis, or "volumetric" chemophoresis, force field that arises from protein-protein interactions and provides a physically viable mechanism for complex translocation. This minimal description captures most known experimental observations: dynamic oscillations of complex components, complex separation, and subsequent symmetrical positioning. The predictions of our model are in phenomenological agreement with and provide substantial insight into recent experiments. From a nonlinear physics view point, this system explores the active separation of matter at micrometric scales with a dynamical instability between static positioning and traveling wave regimes triggered by the dynamical spontaneous breaking of rotational symmetry.

  13. Software and Support Development for an Environmental Data Buoy System for Predicting Surf-Zone Characteristics

    Science.gov (United States)

    1981-02-28

    Version ii • ~PROGRAMr BOPRTM C PROGRAM NAME IS B10 :R T, READS DATA FROM MEHOR’ AN’D CHECKS C; ADDRESS AND PU’S DATA INTO 1024-DATA ARRAY C PRINT OUT...next I -99994X 999941M 29:, 0-* Nif WE 1 J>0; to "neqb" 30: "posb": for L1I to 1024; if WE L >0; ’to "pos" 31: next L rL1t104ifWL K;’o"n" 32: "neqb

  14. SWASH ZONE BED LEVEL CHANGES AND SEDIMENT ENTRAINMENT AT THE SURF-SWASH BOUNDARY

    DEFF Research Database (Denmark)

    Jensen, Stine Gro; Aagaard, Troels; Baldock, Tom

    2010-01-01

    detailed data on water levels and bed elevations in the swash zone. Water levels derived from the pressure transducers show that swash zone characteristics vary from the upper to lower swash. Using pressure transducers in the swash zone coupled with measurements of the hydrodynamics and sediment...

  15. The Rotated Speeded-Up Robust Features Algorithm (R-SURF)

    Science.gov (United States)

    2014-06-01

    of peak magnitude, then three keypoints are created at the same location and different orientations [16]. Additionally, a parabola is fit to the peaks...point m on the parabola , which is located at a fractional distance between 0p and 1p [18]. A new sub-pixel position is assigned to the detected

  16. Wavelength of ocean waves and surf beat at duck from array measurements

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, A.A.; Menon, H.B.; Sarma, Y.V.B.; Jog, P.D.; Almeida, A.M.

    (1) K sub(rms) and (2) K sub(x), K sub(y). The wavelength computed from the array measurements, using both the 3-gauge as well as the SVD (K sub(x), K sub(y)) method, is nearly identical to the wavelength predicted by the well known dispersion...

  17. Research Trends in Massive Open Online Course (MOOC Theses and Dissertations: Surfing the Tsunami Wave

    Directory of Open Access Journals (Sweden)

    Aras Bozkurt

    2016-08-01

    Full Text Available Massive Open Online Courses (MOOCs have attracted a great deal of attention by higher education and private enterprises. MOOCs have evolved considerably since their emergence in 2008, all the while given rise to academic discussions on MOOC impact, design and reach. In an effort to understand MOOCs more comprehensively, this study analyzes theses and dissertations (N = 51 related to MOOCs and published between 2008 and 2015, identifying research trends from these academic documents. Theses and dissertations within this research scope were gathered through a comprehensive search in multiple academic databases. For the purposes of the study, the research employed a systematic review approach. In order to reveal trends in research themes, emphasize theoretical/conceptual backgrounds, research designs and models, first a document analysis was used to collect data and this was followed by a content analysis. Our research findings indicate that MOOC research is generally derived from education, engineering and computer science, as well as information and communication technology related disciplines. Qualitative methodology linked to a case study research model is most common, and the theoretical/conceptual backgrounds are usually distance education related. Remarkably, nearly half of the studies didn’t benefit from any theoretical or conceptual perspectives. In sum, this study presents an evaluation regarding research trends derived from MOOC theses and dissertations, and provides directions for future MOOC research.

  18. Killer Surf Issues: Crafting an Organizational Model to Combat Employee Internet Abuse

    National Research Council Canada - National Science Library

    Kimberly Young

    2010-01-01

    ... an organization to legal liability. Having a clear system in place that incorporates policies and procedures allows organizations to handle incidents of employee Internet abuse swiftly and efficiently...

  19. How to bend galaxy disc profiles II: stars surfing the bar in anti-truncated discs

    CERN Document Server

    Herpich, Jakob; Rix, Hans-Walter; Martig, Marie; Dutton, Aaron A

    2015-01-01

    Simple numerical models can produce the observed radial breaks in the stellar surface density profile of late-type galaxies by varying only one parameter, the initial halo spin {\\lambda}. Here we analyse these simulations in more detail in an effort to identify the physical mechanism that leads to the formation of anti-truncations (Type-III profiles). We find that orbital resonances with a central bar drive stellar orbits from circular orbits with small semi-major axes to rather eccentric orbits with large semi-major axes. These orbits then form a disk-like configuration with high radial dispersion and rotation far below the circular velocity. This will manifest itself in photometry as an anti-truncated (Type-III) outer stellar disk. Whether such outer disks -- with qualitatively new dynamics -- exist in nature can be tested by future observations.

  20. FPGA Accelerated Discrete-SURF for Real-Time Homography Estimation

    Science.gov (United States)

    2015-03-26

    things amazon needs to get its delivery drones off the ground.” 21. E. Rosten and T. Drummond, “Fusing points and lines for high performance tracking...Morrison, and D. H. Shim, “Persis- tent UAV service: An improved scheduling formulation and prototypes of system components,” Journal of Intelligent

  1. Mutations of SURF-1 in Leigh disease associated with cytochrome c oxidase deficiency.

    OpenAIRE

    1998-01-01

    Leigh disease associated with cytochrome c oxidase deficiency (LD[COX-]) is one of the most common disorders of the mitochondrial respiratory chain, in infancy and childhood. No mutations in any of the genes encoding the COX-protein subunits have been identified in LD(COX-) patients. Using complementation assays based on the fusion of LD(COX-) cell lines with several rodent/human rho0 hybrids, we demonstrated that the COX phenotype was rescued by the presence of a normal human chromosome 9. L...

  2. Surfing the money tides: understanding the foreign exchange market through metaphors.

    Science.gov (United States)

    Oberlechner, Thomas; Slunecko, Thomas; Kronberger, Nicole

    2004-03-01

    This study describes metaphorical conceptualizations of the foreign exchange market held by market participants and examines how these metaphors socially construct the financial market. Findings are based on 55 semi-structured interviews with senior foreign exchange experts at banks and at financial news providers in Europe. We analysed interview transcripts by metaphor analysis, a method based on cognitive linguistics. Results indicate that market participants' understanding of financial markets revolves around seven metaphors, namely the market as a bazaar, as a machine, as gambling, as sports, as war, as a living being and as an ocean. Each of these metaphors highlights and conceals certain aspects of the foreign exchange market and entails a different set of implications on crucial market dimensions, such as the role of other market participants and market predictability. A correspondence analysis supports our assumption that metaphorical thinking corresponds with implicit assumptions about market predictability. A comparison of deliberately generated and implicitly used metaphors reveals notable differences. In particular, implicit metaphors are predominantly organic rather than mechanical. In contrast to academic models, interactive and organic metaphors, and not the machine metaphor, dominate the market accounts of participants.

  3. Importance of Antecedent Beach and Surf-Zone Morphology to Wave Runup Predictions

    Science.gov (United States)

    2016-10-01

    tidal dependence in SIG , which instead correlates well with sqrt(HoLo) (r2=0.65, p<ɘ.001). DISCUSSION: The above results are discussed in the...band energy reaching the shoreline, supporting one hypothesis proposed by Guedes et al. (2011). Interestingly, neither Hsig nor SIG correlates with...observed ηR, SIN, and SIG (similar to the approach of Equation 1) and these variables compared with forcing parameters measured at the foreshore (Bf and

  4. iSURF: a family of infinite-time surface flux methods

    Science.gov (United States)

    Morales, F.; Bredtmann, T.; Patchkovskii, S.

    2016-12-01

    The computation and analysis of photoelectron spectra (PES) is a fundamental technique in atomic and molecular physics to study the structural and dynamical properties of a target system, and to gain insight into the process of its ionization. Since the first numerical solutions of the time-dependent Schrödinger equation (TDSE), numerous methods have been developed to extract PES from the calculated wave functions. However, most of these methods have severe limitations or are computationally very demanding. Here we present a new family of methods, based on the ideas of the so-called analytical Volkov continuation, or time-dependent surface flux (Ermolaev et al 1999 Phys. Rev. A 60 483145; Ermolaev and Selin 2000 Phys. Rev. A 62 015401; Tao and Scrinzi 2012 New J. Phys. 14 013021), that allows one to obtain fully-converged PES at the end of the laser pulse using either Volkov states or the exact scattering-states, and that has been implemented in the TDSE solver (Patchkovskii and Muller 2016 Comput. Phys. Commun. 199 153-69).

  5. 76 FR 93 - Summer Undergraduate Research Fellowships (SURF) NIST Gaithersburg and Boulder Programs...

    Science.gov (United States)

    2011-01-03

    ... Program applications, paper and electronic, must be received no later than 5 p.m. Mountain Standard Time..., teaching, or testing. These regulations also do not apply to obtaining animal materials from...

  6. How corporate clients and consumers surf the Internet: A review and future directions for research

    DEFF Research Database (Denmark)

    Gattiker, U.E.; Perlusz, S.; Bohmann, K.

    1999-01-01

    ) assessment of on-line information for different categories of products; (3) influence of people's technology resistance on beliefs and behaviours regarding on-line shopping; and (4), how these factors affect people's attempt to externalise costs (e.g., transaction costs) will be outlined. Few studies address...... the role of socialisation, cultural and situational factors in on-line shopping versus physical store shopping. Moreover, studies on how modifications in the sales channel affect the customer's processing and judgement of information are limited. The article analyses different decisional contexts for Web...... shopping, comparing commodity products to products that require engineering support; while the hype is generally on the first, customised and speciality products may be more attractive from a business perspective. Internet commerce of technical products, in the context of corporate purchasing, has been...

  7. SURFING ON YOUTUBE: THE MASS SELF COMMUNICATION AND THE VIDEOS BROADCASTED BY COMMON USERS

    OpenAIRE

    DANIELA FERNANDES DE OLIVEIRA

    2009-01-01

    Recentemente, de maneira mais extensiva, mas desde o fim da década de 90, um fenômeno pôs em cheque os papéis de quem produz e de quem consome informação no mundo. Esta dissertação procura analisar esse fenômeno na internet, chamado aqui de comunicação individual de massa. Especificamente, o foco deste estudo é o site de compartilhamento de vídeos YouTube, cujo slogan é broadcast yourself, ou seja, transmita você mesmo, e que conta com mais de 78 milhões de vídeos publicados...

  8. The Design and Implementation of a Prototype Surf-Zone Robot for Waterborne Operations

    Science.gov (United States)

    2015-12-01

    developed and tested for mobility in a beachfront environment. Three wheel- designs were tested during fixed pattern tests on grass, concrete and sand. The...part of the internal electronics. To include the connectors in the design, the waterproof cylinder end caps are modified using CNC milling as shown... rubber coating (Plasti-Dip) and a liquid repellent treatment (Rust-Oleum Never Wet–multisurface). An FDM sparse part T5 was coated as depicted in Figure

  9. Design of a Prototype Autonomous Amphibious WHEGS(Trademark) Robot for Surf-Zone Operations

    Science.gov (United States)

    2005-06-01

    screws that are in line with the slotted holes. Once assembled, orthodontic rubber bands are stretched between the fixed screws in the outer shell, and...is received from the user on port 4001. It extracts the information about the required speed and servo position, transmits that directly to the pulse...doesn’t have any errors, it extracts the robots current heading, pitch, and roll information. d. GPS Costatement The GPS costatement is also

  10. "Couch Surfing" of Latino Foster Care Alumni: Reliance on Peers as Social Capital

    Science.gov (United States)

    Perez, Beatrix F.; Romo, Harriett D.

    2011-01-01

    Youth exiting foster care often experience difficulties transitioning into adulthood. This paper focuses on Latino foster care youth in a major southwestern U.S. city and addresses the importance of peer networks as a crucial form of social capital as youth leave foster care. Case studies illustrate experiences of foster care alumni ranging in age…

  11. Réunion : Getting Closer to Paris by Surfing the "Blue Wave"

    NARCIS (Netherlands)

    H.M. Hintjens (Helen); L. Medea (Laurent)

    2009-01-01

    textabstractThe year 2002 reminded the people of Réunion of the power of nature. Cyclone Dina caused destruction and the Piton de la Fournaise volcano erupted twice, causing lava to spill over on to the coastal road and pour into the sea. The main political events were the French presidential

  12. "Couch Surfing" of Latino Foster Care Alumni: Reliance on Peers as Social Capital

    Science.gov (United States)

    Perez, Beatrix F.; Romo, Harriett D.

    2011-01-01

    Youth exiting foster care often experience difficulties transitioning into adulthood. This paper focuses on Latino foster care youth in a major southwestern U.S. city and addresses the importance of peer networks as a crucial form of social capital as youth leave foster care. Case studies illustrate experiences of foster care alumni ranging in age…

  13. Estimating wave energy dissipation in the surf zone using thermal infrared imagery

    National Research Council Canada - National Science Library

    Carini, Roxanne J; Chickadel, C. Chris; Jessup, Andrew T; Thomson, Jim

    2015-01-01

    ...‐resolving model by Duncan (1981). The wave energy dissipation rate estimates show a pattern of increased breaking during low tide over a sand bar, consistent with in situ turbulent kinetic energy dissipation rate estimates from fixed...

  14. Surf zone, infragravity wave energy flux, and runup in extreme conditions

    Science.gov (United States)

    Fiedler, J. W.; Brodie, K. L.; McNinch, J.; Guza, R. T.

    2014-12-01

    Waves, currents, and sand levels were observed on a 1.4 km-long cross-shore transect extending from the back beach to ~11 m water depth at Agate Beach, Oregon in Fall 2013. Wave runup and water table fluctuations on this low slope (1:80) beach were measured with a cliff-mounted scanning Lidar and buried pressure sensors. Significant wave heights at an offshore buoy in 128m depth ranged from small (0.5m) to extreme (7.5m), with peak periods between 4-22 seconds. Infragravity frequency (nominally 0.01 Hz) horizontal runup excursions exceeded 100m, and infragravity cross-shore velocity exceeded 3 m/s. Cross-shore patterns of infragravity wave energy flux, observed with seven co-located pressure and current meters, indicate 'proto-saturation' of the inner surfzone in extreme conditions. That is, the intensification of incident wave forcing (e.g. higher energy, longer swell) leads to a wider surfzone and an increase in the shoreward infragravity wave energy seaward of the surfzone, but produces more modest increases in flux in the inner surfzone, and in the runup. Nonlinear energy balances, based on the observations, show transfer of energy from sea-swell to infragravity waves, and vice-versa. The infragravity energy balance closes in cases with low energy incident sea-swell. With more energetic incident waves, there is an unexplained inner surfzone energy sink at the lowest IG frequencies (0.004-0.02 Hz). Ongoing work aims to quantify the effect on infragravity energy balances by infragravity wave breaking and bottom friction. Additionally, the estimates may be degraded by contamination with rotational velocities of surfzone eddies. Whatever the dynamical explanation, infragravity wave runup on a low slope beach in high-energy conditions is limited significantly by dissipation. The slow rate of runup increase suggests nascent, or 'proto' saturation. This work was supported by the U.S. Army Corps of Engineers.

  15. The importance of the surf zone for fish and brown shrimp in The Netherlands

    NARCIS (Netherlands)

    Teal, L.R.; Keeken, van O.A.

    2011-01-01

    Human activity in the North Sea is increasing, invloving more motorised cargo shipping, and rapidly expanding construction and operation of oil platforms and wind farms. In recent years underwater sand levees or sand suppletion near shore has been performed for coastal protection. The aim of this li

  16. Surfing on the Edge: Chaos vs. Near-Integrability in the System of Jovian Planets

    CERN Document Server

    Hayes, Wayne B

    2007-01-01

    We demonstrate that the system of Jovian planets (Sun+Jupiter+Saturn+Uranus+Neptune), integrated for 200 million years as an isolated 5-body system using many sets of initial conditions all within the uncertainty bounds of their currently known positions, can display both chaos and near-integrability. The conclusion is consistent across four different integrators, including several comparisons against integrations utilizing quadruple precision. We demonstrate that the Wisdom-Holman symplectic map using simple symplectic correctors as implemented in Mercury 6.2 (Chambers 1999) gives a reliable characterization of the existence of chaos for a particular initial condition only with timesteps less than about 10 days, corresponding to about 400 steps per orbit. We also integrate the canonical DE405 initial condition out to 5 Gy, and show that it has a Lyapunov Time of 200--400 My, opening the remote possibility of accurate prediction of the Jovian planetary positions for 5 Gy.

  17. Surf zone dynamics along the south Karnataka Coast between Bhatkal and Ullal, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; SanilKumar, V.; Nayak, B.U.; Raju, N.S.N.

    stronger in June, and relatively low and steady during the rest of the year. Coast between Padubidri and Ullal experienced relatively stronger longshore currents than the coast between Maravanthe and Malpe. Longshore sediment transport rate was relatively...

  18. Temperature limit values for cold touchable surfaces ' ColdSurf ' : final report

    NARCIS (Netherlands)

    Holmer, I.; Havenith, G.; Hartog, E.A. den; Rintamaki, H.; Malchaire, J.

    2000-01-01

    The aim of the project was to find and compile information on human responses to contact with cold surfaces. The work has covered 1) literature search and field survey; 2) experimental studies with human subjects; 3) simulation by modeling; 4) instrumentation (artificial finger), 5) establishment of

  19. Surf with Caution: Online Safety Tips To Follow in and out of Your Head Start Program.

    Science.gov (United States)

    Marcroft, Theresa

    1999-01-01

    Discusses issues related to Internet access in Head Start classrooms. Advocates development of an Internet Acceptable Use Policy for the classroom. Discusses the use of Internet filtering software and child-safe search engines for the classroom and at home. (KB)

  20. Surf with Caution: Online Safety Tips To Follow in and out of Your Head Start Program.

    Science.gov (United States)

    Marcroft, Theresa

    1999-01-01

    Discusses issues related to Internet access in Head Start classrooms. Advocates development of an Internet Acceptable Use Policy for the classroom. Discusses the use of Internet filtering software and child-safe search engines for the classroom and at home. (KB)

  1. Infragravity-wave modulation of short-wave celerity in the surf zone

    NARCIS (Netherlands)

    Tissier, M.; Bonneton, P.; Michallet, H.; Ruessink, B.G.

    2015-01-01

    The cross-shore evolution of individual wave celerity is investigated using two highresolution laboratory experiments on bichromatic waves. Individual waves are tracked during their onshore propagation and their characteristics, including celerity, are estimated. The intrawave variability in celerit

  2. Modified boundary conditions and field equations for a 2D surf beat model

    NARCIS (Netherlands)

    Petit, H.A.H.; Klopman, G.; Battjes, J.A.

    2001-01-01

    This progress report refers to work done at the Fluid IVlechanics Section within the framework of the Netherlands Centre for Coastal Research (NCK). In the coastal zone the long wave motion may contribute significantly to the morpho-dynamics, due to its strong correlation with the short wave motion

  3. W1045 environment surf drip shield and waste package outer barrier

    Energy Technology Data Exchange (ETDEWEB)

    Gdowski, G

    1999-07-14

    The environments on the drip shield and waste package outer barrier are controlled by the compositions of the waters that contact these components. the temperature (T) of these components, and the effective relative humidity (RH) at these components. Because the composition of the waters that are expected to enter the emplacement drifts (either by seepage flow or by episodic flow) have not been specified: well J13 water was chosen as the reference water (Harrar 1990). Section 6.2 discusses the accessible RH for the temperatures of interest at the repository horizon. Section 6.3 discusses the adsorption of water on metal alloys in the absence of hygroscopic salts. Because the temperatures of the DSs and the WPOBs are higher than those of the surrounding near-field environment, the relative humidity at the DSs and the WPOBs will be lower than that of the surrounding near-field environment. This difference is a result of the water partial pressure in the drift being constant and no higher than the equilibrium water vapor pressure at the temperature of the drift wall.

  4. 76 FR 65180 - Proposed Information Collection; Comment Request; Application to Shuck Surf Clams/Ocean Quahogs...

    Science.gov (United States)

    2011-10-20

    ... Exclusive Economic Zone (EEZ) of the Northeastern United States through the Atlantic Surfclam and Ocean...). Affected Public: Business or other for-profit organizations. Estimated Number of Respondents: 205... proposed collection of information is necessary for the proper performance of the functions of the...

  5. Cross-shore suspended sediment transport in the surf zone: A fieldbased parameterization

    DEFF Research Database (Denmark)

    Aagaard, Troels; Black, Kerry; Greenwood, Brian

    2002-01-01

    sediment transport, sediment concentrations, incident waves, undertow, morphodynamics, beach processes......sediment transport, sediment concentrations, incident waves, undertow, morphodynamics, beach processes...

  6. iSURF: A family of infinite-time surface flux methods

    CERN Document Server

    Morales, F; Patchkovskii, S

    2016-01-01

    The computation and analysis of photoelectron spectra (PES) is a fundamental technique in atomic and molecular physics to study the structural and dynamical properties of a target system, and to gain insight into the process of its ionization. Since the first numerical solutions of the time-dependent Schr\\"odinger equation, numerous methods have been developed to extract PES from the calculated wave functions. However, most of these methods have severe limitations or are computationally very demanding. Here we present a new family of methods, based on the ideas of the so-called analytical Volkov continuation, or time-dependent surface flux ([Ermolaev, A. M. et al. Phys. Rev. A 60, 4831 (1999), Ermolaev, A. M. et al. Phys. Rev. A 62, 015401 (2000), Tao L. and Scrinzi A. New Journal of Physics 14, 013021 (2012)]), that allows one to obtain fully-converged PES at the end of the laser pulse using either Volkov states or the exact scattering-states, and that has been implemented in the Time Dependent Schr\\"odinger...

  7. Waves, Currents, and Sediment Transport in the Surf Zone Along Long, Straight Beaches

    Science.gov (United States)

    2005-08-01

    bmx + F bwx + F srx + F swmx + F srmx (4.49) τ cby = F bmy + F bwy...F sry + F swmy + F srmy +F bvy (4.50) with F bhpx = −ρgh ∂¯η ∂x (4.51) 119 F bmx = −ρ ∂ ∂x ( aU 2 s + q bx U 0 ) (4.52) F bwx = − ∂ ∂x S xx (4.53) F...shows “mean-current- associated” forcing terms due to the mean current advection, F bmx (thin full line), the interaction of waves and mean currents,

  8. Polluted online information? Surfing Italian websites dealing with the topic of waste and health

    Science.gov (United States)

    Orizio, G.; Locatelli, M. K.; Caimi, L.; Gelatti, U.

    2011-10-01

    In the field of health communication, a particularly critical issue is communication to the public of environmental risks, especially on topics for which there is still a high degree of scientific uncertainty regarding risk estimates. One such topic is undoubtedly the impact of waste on people's health. The aim of this study was to evaluate the presence and characteristics of Italian websites dealing with the topic of waste and health. The keywords 'waste' and 'health' were entered in 2010 in the three most commonly used search engines, and the first five pages were analysed. The selected websites were coded according to the content analysis method. For websites of interest we evaluated the 'page rank'. Out of the 150 occurrences analysed, the number of websites found to deal with this subject was only 19, four of which were of an institutional nature. The majority of websites gave a message of increased health risk associated with the three kinds of waste disposal tackled. As regards visibility, only one of the four institutional websites maintained its position on the first page of the three search engines. We found that institutional health websites have low visibility, despite extensive media coverage of waste and health issues in Italy as a result of the Naples case, which was debated globally. This indicates that public health institutions' web strategies are basically unable to meet people's health information requirements, which could strengthen rival health information providers.

  9. Metadynamics Surfing on Topology Barriers: the CP(N-1) Case

    CERN Document Server

    Laio, Alessandro; Sanfilippo, Francesco

    2015-01-01

    In the continuum limit, QCD systems, investigated via numerical simulations, remain trapped in sectors of field space with fixed topological charge. As a consequence the numerical studies of physical quantities may give biased results. The same is true in the case of two dimensional CP(N-1) models. In this paper we show that Metadynamics, applied to CP(N-1), allows to bypass very efficiently this problem. In particular we show, for the first time, that we are able to reconstruct the free energy of the topological charge, F(Q), as a function of the coupling and of the volume. This is a very important physical quantity in studies of the dynamics of the theta-vacuum and of the axion. The method can be easily extended to QCD.

  10. Surfing Second Life: What Does Second Life Have to Do with Real-Life Learning?

    Science.gov (United States)

    Oishi, Lindsay

    2007-01-01

    Second Life's unstructured atmosphere and wide-open spaces where student creativity can grow and flourish are two of the reasons Pepperdine University Professor Bill Moseley integrated the program into his curriculum. In this article, the author discusses how Second Life works and its challenges. Second Life is often described as a 3-D version of…

  11. Research Trends in Massive Open Online Course (MOOC) Theses and Dissertations: Surfing the Tsunami Wave

    Science.gov (United States)

    Bozkurt, Aras; Keskin, Nilgun Ozdamar; de Waard, Inge

    2016-01-01

    Massive Open Online Courses (MOOCs) have attracted a great deal of attention by higher education and private enterprises. MOOCs have evolved considerably since their emergence in 2008, all the while given rise to academic discussions on MOOC impact, design and reach. In an effort to understand MOOCs more comprehensively, this study analyzes theses…

  12. Winter feeding ecology and trophic relationships of marine birds in Kachemak Bay, Alaska: Final report to the Outer Continental Shelf Environmental Assessment Program

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The winter feeding ecology of oldsquaw, white-winged scoters, common murres and marbled murrelet was studied on Kachemak Bay, Alaska, from November 1977 through...

  13. Isolation of a library of aromadendranes from Landolphia dulcis and its characterization using the VolSurf approach

    DEFF Research Database (Denmark)

    Staerk, Dan; Skole, Brian; Jørgensen, Flemming Steen

    2004-01-01

    A library of nine aromadendrane-type sesquiterpenes (1-9), including eight new natural products (1-5 and 7-9), was isolated from Landolphia dulcis var. barteri along with a previously described cadinane derivative (10) and a new muurolane derivative (11). The structures of all compounds were...... established by means of NMR methods including COSY, NOESY, HSQC, and HMBC experiments, supported by HRMS and optical rotation data. Virtual characterization of the aromadendrane library (1-9) was performed using chemoinformatics tools. 3D molecular fields were calculated with the GRID program using low......, a considerable chemical diversity within the library was disclosed, despite a close biosynthetic relationship of its members. The results can be interpreted in terms of evolutionary optimization of structures of secondary metabolites for interaction with macromolecular targets and are of interest in terms...

  14. Dependence of the surf zone aerosol on wind direction and wind speed at a coastal site on the Baltic Sea

    Directory of Open Access Journals (Sweden)

    Tymon Zieliński

    2003-09-01

    Full Text Available Since 1992 lidar-based measurements have been carried out under various meteorological conditions and at various times of the year. The aerosol optical properties were determined in the marine boundary layer as a function of altitude using such factors as wind direction, duration and velocity and aerosol size distribution and concentration. It was confirmed that in all cases, the total aerosol concentration, size distribution and aerosol extinction increase with wind speed but decrease with altitude. In the range of wind velocities from 1 to 15 m s-1 the mean aerosol optical thickness of the atmosphere (VIS obtained from the lidar varied from 0.1 to 0.38 for offshore winds and from 0.01 to about 0.1 for onshore winds, while the Ångström parameter for VIS oscillated around 0.65 for onshore winds and around 1 for offshore winds. Both parameters depended strongly on the history of the air mass above the Baltic Sea. Such aerosol optical thicknesses are in agreement with those obtained by other researchers in the Baltic Sea area.

  15. Shoreline clean up during the Sea Empress incident: the role of surf washing (clay-oil flocculation), dispersants and bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Lunel, T. [AEA Technology, Culham (United Kingdom); Lee, K. [Department of Fisheries and Oceans, Mont-Joli, PQ (Canada). Inst. Maurice-Lamontagne; Swannell, R.; Wood, P.; Rusin, J.; Bailey, N.; Halliwell, C.; Davies, L.; Sommerville, M.; Dobie, A.; Mitchell, D.; McDonagh, M. [AEA Technology, Culham (United Kingdom)

    1996-09-01

    An outline of the at sea operations which took place in response to the Sea Empress oil spill, was presented. The grounding of the Sea Empress resulted in the release of 70,000 tonnes of blended crude oil into the environment. A qualitative account of the events which followed the incident were described. The early mobilization of a monitoring team has demonstrated the importance of scientific measurements to identify and maximize the efficiency of various cleanup operations. One of the important responses to this incident was the application of dispersants which by inducing flocculation, thereby reducing contact of oil directly with the substrate, and by reducing adhesion of the oil to the shoreline, contributed greatly to minimizing shoreline impact. 19 refs., 7 figs.

  16. Retrieval system for emplaced spent unreprocessed fuel (SURF) in salt bed depository. Baseline concept criteria specifications and mechanical failure probabilities

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, E.E.; McCleery, J.E.

    1979-05-01

    One of the integral elements of the Nuclear Waste Management Program is the material handling task of retrieving Canisters containing spent unreprocessed fuel from their emplacement in a deep geologic salt bed Depository. A study of the retrieval concept data base predicated this report. In this report, alternative concepts for the tasks are illustrated and critiqued, a baseline concept in scenario form is derived and basic retrieval subsystem specifications are presented with cyclic failure probabilities predicted. The report is based on the following assumptions: (a) during retrieval, a temporary radiation seal is placed over each Canister emplacement; (b) a sleeve, surrounding the Canister, was initially installed during the original emplacement; (c) the emplacement room's physical and environmental conditions established in this report are maintained while the task is performed.

  17. 益普索:无线上网步入春天%IPSOS: Spring for the Wireless Surfing

    Institute of Scientific and Technical Information of China (English)

    贾艳丽

    2005-01-01

    根据益普索(Ipsos)的一项调查,全球无线上网正呈现高速发展的趋势,而在中国这种趋势则更加明显。这项调查是益普索(Ipsos)集团在全球范围内的12个国家进行的,包括中国、美国、英国、日本、韩国、巴西、俄罗斯等,调查结果显示,2004年全球无线上网的增长达29%,其中美国和日本这两个最大的市场合计增长了69%,

  18. Control of computer's surf on internet by SPI%利用SPI控制计算机上网

    Institute of Scientific and Technical Information of China (English)

    胡珊; 张冰

    2004-01-01

    分析利用SPI接口来实现控制windows Socket应用程序的原理和其中的技术细节.介绍了用自编的SPI服务的DLL替代Windows SPI DLL的方法和被控端的进程隐藏、SPI服务DLL的安装和卸载和命令倾听等.

  19. Interaction between breaking/broken waves and infragravity-scale phenomena to control sediment suspension transport in the surf zone

    CSIR Research Space (South Africa)

    Smith, GG

    2002-07-30

    Full Text Available of instrumentation, ?ume geometry, water-levels, wave conditions tested, etc. reference is made to Sanchez-Arcilla et al. (1994). For the purpose of the present study, use was primarily made of instrumentation attached to a roving car- riage deployed at various... the carriage to measure beach pro?les (San- chez-Arcilla et al., 1994). The present study makes use of measurements taken during the second series of tests at LIP11D (Tests 2A and 2B). Test 2A was commenced with a Dean-type beach pro?le, with a dune included...

  20. Surfing the waves of change in reproductive medicine: past, present and future. A presentation of the 2014 ASRM Strategic Plan.

    Science.gov (United States)

    Reindollar, Richard H

    2015-01-01

    A presentation at the Opening Ceremony of the ASRM Seventieth Annual Meeting reviews advances in reproductive medicine and presents an overview of the 2014 Strategic Plan: "Global Impact Through Dynamic Engagement."

  1. Surfing the Protein-Protein Interaction Surface Using Docking Methods: Application to the Design of PPI Inhibitors

    Directory of Open Access Journals (Sweden)

    Rushikesh Sable

    2015-06-01

    Full Text Available Blocking protein-protein interactions (PPI using small molecules or peptides modulates biochemical pathways and has therapeutic significance. PPI inhibition for designing drug-like molecules is a new area that has been explored extensively during the last decade. Considering the number of available PPI inhibitor databases and the limited number of 3D structures available for proteins, docking and scoring methods play a major role in designing PPI inhibitors as well as stabilizers. Docking methods are used in the design of PPI inhibitors at several stages of finding a lead compound, including modeling the protein complex, screening for hot spots on the protein-protein interaction interface and screening small molecules or peptides that bind to the PPI interface. There are three major challenges to the use of docking on the relatively flat surfaces of PPI. In this review we will provide some examples of the use of docking in PPI inhibitor design as well as its limitations. The combination of experimental and docking methods with improved scoring function has thus far resulted in few success stories of PPI inhibitors for therapeutic purposes. Docking algorithms used for PPI are in the early stages, however, and as more data are available docking will become a highly promising area in the design of PPI inhibitors or stabilizers.

  2. VirHostNet 2.0: surfing on the web of virus/host molecular interactions data.

    Science.gov (United States)

    Guirimand, Thibaut; Delmotte, Stéphane; Navratil, Vincent

    2015-01-01

    VirHostNet release 2.0 (http://virhostnet.prabi.fr) is a knowledgebase dedicated to the network-based exploration of virus-host protein-protein interactions. Since the previous VirhostNet release (2009), a second run of manual curation was performed to annotate the new torrent of high-throughput protein-protein interactions data from the literature. This resource is shared publicly, in PSI-MI TAB 2.5 format, using a PSICQUIC web service. The new interface of VirHostNet 2.0 is based on Cytoscape web library and provides a user-friendly access to the most complete and accurate resource of virus-virus and virus-host protein-protein interactions as well as their projection onto their corresponding host cell protein interaction networks. We hope that the VirHostNet 2.0 system will facilitate systems biology and gene-centered analysis of infectious diseases and will help to identify new molecular targets for antiviral drugs design. This resource will also continue to help worldwide scientists to improve our knowledge on molecular mechanisms involved in the antiviral response mediated by the cell and in the viral strategies selected by viruses to hijack the host immune system.

  3. Facilitating Autonomy and Creativity in Second Language Learning through Cyber-Tasks, Hyperlinks and Net-Surfing

    Science.gov (United States)

    Akinwamide, T. K.; Adedara, O. G.

    2012-01-01

    The digitalization of academic interactions and collaborations in this present technologically conscious world is making collaborations between technology and pedagogy in the teaching and learning processes to display logical and systematic reasoning rather than the usual stereotyped informed decisions. This simply means, pedagogically, learning…

  4. Proposal and Its Evaluation of a Shoulder-Surfing Attack Resistant Authentication Method:Secret Tap with Double Shift

    Directory of Open Access Journals (Sweden)

    Yoshihiro Kita

    2015-05-01

    Full Text Available Recently, mobile terminals such as smartphones have come into widespread use. Most of such mobile terminals store several types of important data, such as personal information. Therefore, it is necessary to lock and unlock terminals using a personal authentication method such as personal identification numbers (PINs in order to prevent data theft. However, most existing authentication methods have a common problem referred to here as “shoulder-surfing”, in which authentication information is covertly obtained by a person watching “over-the-shoulder” of a user as he/she completes the authentication sequence. In the present paper, a new icon-based authentication method that is simple but sufficiently secure even when the authentication sequence is being watched is proposed. The proposed method is implemented on a mobile data terminal and is evaluated through experiments and questionnaire surveys.

  5. 超便携电脑——细品华硕Eee PC 4G Surf

    Institute of Scientific and Technical Information of China (English)

    极品⊙金枪鱼

    2008-01-01

    <正>华硕Eee PC还没有入手之前,小编就被无数人问到关于Eee PC的种种问题,如外观、性能好坏等等,很久都没有这种期待的感觉了。当看到真机时,才发现Eee PC的不凡之处。Eee PC不是功能强大的笔记本,却能提供笔记本的大部分功能。淡蓝色

  6. GeoSurf - geoelectric soil modelling for a sustainable land use and efficient planning of shallow geothermal systems

    Science.gov (United States)

    Bertermann, David; Walker-Hertkorn, Simone; Kübert, Markus; Schmidt, David; Di Sipio, Eloisa; Müller, Johannes; Schwarz, Hans

    2016-04-01

    Due to the increased demand of biomaterials and renewable primary products the world's soil is intensively effected. Land usage needs to be efficient, space-saving and sustainable. To fulfil these needs soil properties have to be analysed and mapped. Furthermore the shortage of resources will boost the role of renewable energy sources within all energy supplying systems. Also for very shallow geothermal systems (e.g. collectors or heat baskets) detailed information of soil properties are necessary. The most important parameters for characterisation of the soil body are grain size distribution, bulk density and moisture content. Within this project geoelectric measurements more than 50 m wide and 20 m deep cross-sections were made. The above-named soil properties and the thermal conductivity were determined as well. The soil parameters were analysed regarding their effects on thermal- and electric conductivity. With the results of these geoelectric cross-sections in comparison with the measured soil texture, reliable statements about the existing soil properties and a deduction of its thermal conductivity can be made. Within the uppermost meters of the ground, thermal conductivity is mainly driven by soil type. So reasonable recommendations of soil properties and its thermal conductivity are possible only by measuring the electrical conductivity. With these measurements also clear and demonstrative soil models can be illustrated. The electrical conductivity provides expedient information about the soil that opens up the opportunity for clear recommendations about sustainable land use and for site-specific installation of very shallow geothermal system. Also predictions for other soil controlled investigations are possible.

  7. Low Background Counting with the Berkeley Low Background Facility and the Black Hills State University Underground Campus at SURF

    Science.gov (United States)

    Poon, Alan; Thomas, Keenan; Mount, Brianna; Lesko, Kevin; Smith, Alan; Norman, Eric; Chan, Yuen-Dat; Berkeley Low Background Facility Team; Black Hills State University Underground Campus Team

    2016-09-01

    The Berkeley Low Background Facility provides a variety of low background gamma spectroscopy services to a variety of projects and experiments. It operates HPGe spectrometers in two unique facilities: a surface low background lab at LBNL and 4,850 feet underground (4300 m.w.e.) at the Sanford Underground Research Facility in Lead, SD in a dedicated cleanroom at the Black Hills State University Underground Campus (BHUC). A large component of the measurements performed by the BLBF are for ultralow background experiments concerned with U, Th, K, and other radioisotopes within candidate construction materials to be used to construct sensitive detectors. Experiments utilizing these needs often include those studying dark matter, neutrinos, or neutrinoless double beta decay. A general overview of the services and facilities will be presented. The BHUC will ultimately host several HPGe low background counting stations and other sensitive instruments from several incoming low background groups and projects that will operate in a coordinated manner to provide low background measurements to the scientific community. An overview and description of the BHUC facility, status, and future plans will also be discussed.

  8. Development and Testing of a Hybrid Wheg (trademark)-Mobile Platform for Autonomous Surf-Zone Operations

    Science.gov (United States)

    2011-12-01

    transmitted to the front Wheg through a 0.5 inch driveshaft mounted internally to a 1 inch suspension shaft and then through a set of geared pulleys ...that engages additional teeth on the smaller pulley . The final gear ratio is 46:1. The Whegs turn at 178 RPM under no load and nominal motor voltage...can minimize load friction and inertia by the proper selection of the gear ratio N. Jeq = Ja + 1 N2 Jl (2.8) Feq = Fa + 1 N2 Fl (2.9) 2.3 Quasi

  9. Fitting statistical distributions to sea duck count data: implications for survey design and abundance estimation

    Science.gov (United States)

    Zipkin, Elise F.; Leirness, Jeffery B.; Kinlan, Brian P.; O'Connell, Allan F.; Silverman, Emily D.

    2014-01-01

    Determining appropriate statistical distributions for modeling animal count data is important for accurate estimation of abundance, distribution, and trends. In the case of sea ducks along the U.S. Atlantic coast, managers want to estimate local and regional abundance to detect and track population declines, to define areas of high and low use, and to predict the impact of future habitat change on populations. In this paper, we used a modified marked point process to model survey data that recorded flock sizes of Common eiders, Long-tailed ducks, and Black, Surf, and White-winged scoters. The data come from an experimental aerial survey, conducted by the United States Fish & Wildlife Service (USFWS) Division of Migratory Bird Management, during which east-west transects were flown along the Atlantic Coast from Maine to Florida during the winters of 2009–2011. To model the number of flocks per transect (the points), we compared the fit of four statistical distributions (zero-inflated Poisson, zero-inflated geometric, zero-inflated negative binomial and negative binomial) to data on the number of species-specific sea duck flocks that were recorded for each transect flown. To model the flock sizes (the marks), we compared the fit of flock size data for each species to seven statistical distributions: positive Poisson, positive negative binomial, positive geometric, logarithmic, discretized lognormal, zeta and Yule–Simon. Akaike’s Information Criterion and Vuong’s closeness tests indicated that the negative binomial and discretized lognormal were the best distributions for all species for the points and marks, respectively. These findings have important implications for estimating sea duck abundances as the discretized lognormal is a more skewed distribution than the Poisson and negative binomial, which are frequently used to model avian counts; the lognormal is also less heavy-tailed than the power law distributions (e.g., zeta and Yule–Simon), which are

  10. Comment on "Simple thermodynamic derivation of the electrocapillary equations" by E.M. Gutman [Surf. Sci. 639 (2015) L5-L8

    Science.gov (United States)

    Makkonen, Lasse

    2016-05-01

    Gutman [1] presents strongly worded criticism on the recent effort to simplify the derivations of the electrocapillary equations by a clear-cut thermodynamic analysis [2]. It is outlined here that the points raised by Gutman [1] are misunderstandings of the purpose and the details of the criticized paper [2].

  11. SPITZER ULTRA FAINT SURVEY PROGRAM (SURFS UP). II. IRAC-DETECTED LYMAN-BREAK GALAXIES AT 6 ≲ z ≲ 10 BEHIND STRONG-LENSING CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Kuang-Han; Bradač, Maruša; Hoag, Austin; Cain, Benjamin; Lubin, L. M.; Knight, Robert I. [University of California Davis, 1 Shields Avenue, Davis, CA 95616 (United States); Lemaux, Brian C. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Ryan, R. E. Jr.; Brammer, Gabriel B. [Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France); Castellano, Marco; Amorin, Ricardo; Fontana, Adriano; Merlin, Emiliano [INAF—Osservatorio Astronomico di Roma Via Frascati 33, I-00040 Monte Porzio Catone (Italy); Schmidt, Kasper B. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Schrabback, Tim [Argelander-Institut für Astronomie, Auf Dem Hügel 71, D-53121 Bonn (Germany); Treu, Tommaso [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095 (United States); Gonzalez, Anthony H. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States); Linden, Anja von der, E-mail: khhuang@ucdavis.edu, E-mail: astrokuang@gmail.com [Department of Physics, Stanford University, 382 Via Pueblo Mall, Stanford, CA 94305 (United States)

    2016-01-20

    We study the stellar population properties of the IRAC-detected 6 ≲ z ≲ 10 galaxy candidates from the Spitzer UltRa Faint SUrvey Program. Using the Lyman Break selection technique, we find a total of 17 galaxy candidates at 6 ≲ z ≲ 10 from Hubble Space Telescope images (including the full-depth images from the Hubble Frontier Fields program for MACS 1149 and MACS 0717) that have detections at signal-to-noise ratios  ≥ 3 in at least one of the IRAC 3.6 and 4.5 μm channels. According to the best mass models available for the surveyed galaxy clusters, these IRAC-detected galaxy candidates are magnified by factors of ∼1.2–5.5. Due to the magnification of the foreground galaxy clusters, the rest-frame UV absolute magnitudes M{sub 1600} are between −21.2 and −18.9 mag, while their intrinsic stellar masses are between 2 × 10{sup 8}M{sub ⊙} and 2.9 × 10{sup 9}M{sub ⊙}. We identify two Lyα emitters in our sample from the Keck DEIMOS spectra, one at z{sub Lyα} = 6.76 (in RXJ 1347) and one at z{sub Lyα} = 6.32 (in MACS 0454). We find that 4 out of 17 z ≳ 6 galaxy candidates are favored by z ≲ 1 solutions when IRAC fluxes are included in photometric redshift fitting. We also show that IRAC [3.6]–[4.5] color, when combined with photometric redshift, can be used to identify galaxies which likely have strong nebular emission lines or obscured active galactic nucleus contributions within certain redshift windows.

  12. Wave breaking in the surf zone and deep-water in a non-hydrostatic RANS model. Part 2: Turbulence and mean circulation

    Science.gov (United States)

    Derakhti, Morteza; Kirby, James T.; Shi, Fengyan; Ma, Gangfeng

    2016-11-01

    Field-scale modeling of wave-breaking-induced turbulence and mean circulation is still challenging. Although Boussinesq-type models have been successfully used to study field-scale wave transformation and wave-breaking-driven circulation, they cannot provide turbulence or the vertical structure of the velocity field. In addition, the applicability of such models is limited to shallow water. In Part 1 (Derakhti et al., 2016b) of this study, we showed that the non-hydrostatic σ-coordinate RANS model NHWAVE, as described by Derakhti et al. (2016a), accurately predicts organized wave motions and total wave-breaking-induced energy dissipation from deep-water up to the swash zone using a few vertical σ-layers. In this paper, our goal is to examine what level of detail of wave-breaking-induced turbulence and mean circulation, both in depth- and steepness-limited breaking waves, can be reproduced by NHWAVE. Further, effects of modeled turbulent eddy viscosity on the predicted time-averaged velocity distribution is discussed. We establish that NHWAVE is capable of predicting the structure of the mean velocity and vorticity fields including large-scale breaking-induced coherent vortices in deep-water breaking events; where the absence of turbulence-induced eddy viscosity results in the overprediction of the velocity and vorticity field in the breaking region. We show that NHWAVE reduces the required CPU time up to two orders of magnitude in comparison with a comparable VOF-based simulation.

  13. Surfing USA: How Internet Use Prior to and during Study Abroad Affects Chinese Students' Stress, Integration, and Cultural Learning While in the United States

    Science.gov (United States)

    Mikal, Jude P.; Yang, Junhong; Lewis, Amy

    2015-01-01

    Campuses across the United States continue to welcome a record number of Chinese students coming in pursuit of both academic and cultural goals. Yet, high levels of acculturative stress coupled with difficulties integrating into life abroad jeopardize accomplishing these goals. In this study, we examine Chinese students' Internet use both prior to…

  14. Hydrodynamic and Sediment Transport Model Application for OSAT3 Guidance: Surf-zone integrated alongshore potential flux for oil-sand balls

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey has developed a method for estimating the mobility and potential alongshore transport of heavier-than-water sand and oil agglomerates...

  15. Engineering Foundation Conference: Advances in optics for biotechnology, medicine, and surgery, Kona Surf Resort and Conference Center, Kailua-Kona, Hawaii, August 1-6, 1999. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Yodh, Arjun; Sevick-Muraca, Eva; Benaron, David

    2001-09-01

    The intent of the conference was to gather a group of cross-disciplinary investigators from universities, medical schools, national laboratories, industry, and government in order to highlight future applications and technology of the optical sciences in biotechnology, medicine, and surgery. The session chairs brought new participants and speakers to the conference who were not regular attendees of the OSA and SPIE conferences. Attendees included a good number of graduate and post-doctoral students who tended to join the more senior members in organized and spontaneous afternoon activities. A critique of the conference is given which discusses things that worked well and things that could have been better, focusing on costs, funding, and speaker cancellations. Sessions were held on the following topics: Photodynamic therapy: fundamental and clinical studies; Frontiers in spectroscopy; Photon migration; Advances in tissue microscopy, dyes and reporters; Advances in cell microscopy: spectroscopy and micromanipulation; Laser-tissue interactions: therapeutic interventions; and Optics for biotechnology. Along with the program and participant lists, nearly 50 poster presentations are included.

  16. Corrigendum to “Enhancing coating of brushite/hydroxyapatite layer on titanium alloy implant surface with additives” [Appl. Surf. Sci. 285P (2013) 136-143

    Science.gov (United States)

    Abdel-Aal, E. A.; El-Sayed, D.; Shoeib, M.; Kandil, A. T.; Kandil, A. T.

    2014-01-01

    The authors regret typos in Ref. [27] "R. Dreveta, H. Benhayounea, L. Worthama, S. Potirona, J. Dougladeb, D. Laurent-Maquina" should be replaced by "R. Drevet, H. Benhayoune, L. Wortham, S. Potiron, J. Douglade, D. Laurent-Maquin".

  17. Hydrodynamic and Sediment Transport Model Application for OSAT3 Guidance: Surf-zone integrated alongshore potential flux for oil-sand balls

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey has developed a method for estimating the mobility and potential alongshore transport of heavier-than-water sand and oil agglomerates...

  18. Longshore sediment transport in the surf zone based on different formulae: A case study along the central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Shanas, P.R.; Dora, G.U.; Johnson, G.; Philip, C.S.

    Understanding longshore sediment transport (LST) is a prerequisite for designing an effective coastal zone management strategy. The present study estimates the LST along the central west coast of India based on four bulk LST formulae: (1...

  19. 激光驱动的等离子体波:新型冲浪%Plasma Waves Driven by Lasers:The New Surfing

    Institute of Scientific and Technical Information of China (English)

    Simon Mitton; 黄矛

    2006-01-01

    剑桥大学卡文迪什实验室有一个小型博物馆,收藏了诺贝尔奖得主揭开原子和原子核奥秘所使用的仪器装置。这些装置显著的特点就是小尺度。查德威克(Chadwick)发现原子核的实验装置、威尔逊(Wilson)云室以及第一批阴极射线管都各自被用单手举起来。这与正在日内瓦建造中的耗资80亿美元、周长27km的大型强子对撞机(LHC)形成鲜明的对比。半个世纪以来,巨大的加速器一直是粒子物理学的核心。

  20. 2000年世界表面活性剂和洗涤剂展望(英)%Surfing through the Year 2000

    Institute of Scientific and Technical Information of China (English)

    安东尼奥特里斯; 伯恩特布雷赫曼; 丁永利

    2001-01-01

    Both consumers and producers influence the development of the surfactant market,closely linked is the effect on the individual surfactant types and the raw materials used for their manufacture. The importance of market research and proximity between the market and customer is inter preted , the fourteen influential factors are studied.%消费者与制造商均影响表面活性剂市场的发展,市场特点和世界经济国际化将影响表面活性剂类型及制造所用的原材料。通过实例阐明了市场研究、市场与消费者关系的重要性,提出了影响表面活性剂发展的14个因素。

  1. Errata: “Switchable 1,8-diazabicycloundec-7-ene and 1-hexanol ionic liquid analyzed by liquid ToF-SIMS” [Surf. Sci. Spectra 23 , 9 (2016)

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Juan; Zhou, Yufan; Sui, Xiao; Lao, David; Heldebrant, David; Zhu, Zihua; Yu, Xiao-Ying

    2017-06-01

    The identification of a number of mass peaks in the switchable ionic liquid (SWIL) observed in ToF-SIMS is updated based on the most likely chemical formation pathways. The revised identification better reflects the chemical interactions in the SWIL consisting of DBU, 1-hexanol and CO2. A companion paper illustrates the formation mechanism of these updated species is currently under review.

  2. The Design and Implementation of a Semi-Autonomous Surf-Zone Robot Using Advanced Sensors and a Common Robot Operating System

    Science.gov (United States)

    2011-06-01

    the entire robot. The torque of the motor and gearing allowed the tail to lift the entire rear of the robot. Dynamic tests were conducted to...associated drive assembly. Each assem- bly contains a belt and pulley configuration that transfers torque from the drive assembly to each WhegTM. It...watertight integrity of the overall design. This single unit will encase the servo drive gears shielding it from debris and sand and thus preventing damage

  3. Wave breaking in the surf zone and deep-water in a non-hydrostatic RANS model. Part 1: Organized wave motions

    Science.gov (United States)

    Derakhti, Morteza; Kirby, James T.; Shi, Fengyan; Ma, Gangfeng

    2016-11-01

    We examine wave-breaking predictions ranging from shallow- to deep-water conditions using a non-hydrostatic σ-coordinate RANS model NHWAVE as described in Derakhti et al. (2016a), comparing results both with corresponding experiments and with the results of a volume-of-fluid (VOF)/Navier-Stokes solver (Ma et al., 2011; Derakhti and Kirby, 2014a,b). Our study includes regular and irregular depth-limited breaking waves on planar and barred beaches as well as steepness-limited unsteady breaking focused wave packets in intermediate and deep water. In Part 1 of this paper, it is shown that the model resolves organized wave motions in terms of free-surface evolution, spectral evolution, organized wave velocity evolution and wave statistics, using a few vertical σ-levels. In addition, the relative contribution of modeled physical dissipation and numerical dissipation to the integral breaking-induced wave energy loss is discussed. In steepness-limited unsteady breaking focused wave packets, the turbulence model has not been triggered, and all the dissipation is imposed indirectly by the numerical scheme. Although the total wave-breaking-induced energy dissipation is underestimated in the unsteady wave packets, the model is capable of predicting the dispersive and nonlinear properties of different wave packet components before and after the break point, as well as the overall wave height decay and the evolution of organized wave velocity field and power spectrum density over the breaking region. In Part 2 (Derakhti et al., 2016b), model reproduction of wave-breaking-induced turbulence and mean circulation is examined in detail. The same equations and numerical methods are used for the various depth regimes, and no ad-hoc treatment, such as imposing hydrostatic conditions, is involved in triggering breaking. Vertical grid resolution in all simulated cases is at least an order of magnitude coarser than that of typical VOF-based simulations.

  4. Diel and tidal variation in surf zone fish assemblages of a sheltered beach in southern Brazil Variación diaria y mareal de ensambles de peces en la zona de surf de una playa protegida en el sur de Brasil

    Directory of Open Access Journals (Sweden)

    Fabiana C Félix-Hackradt

    2010-01-01

    Full Text Available Diel and tidal variations of fish assemblages were assessed at Pontal beach, southern Brazil, using a seine net. Species richness was greater at night, whereas fish number, weight, and richness (cornmunity indicators were all influenced by the tidal state. Samples from rising tides were more representative, probably due to onshore fish movements for feeding purposes. However, lower catches were associated with high tides, mainly through net avoidance, indicating that sampling in these conditions is not highly informative. Clupeoids exhibited greater variation in a 24 h period, and the night occurrence of A. tricolor and daylight shoaling of Harengula clupeola, Anchoa parva and Sardinella brasiliensis suggested distinct strategies for avoiding daylight predators. In some species, this behaviour may have been induced by the bottom morphology and tidal state, facilitating nearshore grouping. In addition to being caught at night, the occurrences of Menticirrhus littoralis, Pomadasys corvinaefórmis, Umbrina coroides and Hyporhamphus unifasciatus indicated a spatial niche partition according to tidal state. Although not evaluated properly, temporal fluctuations could reflect species recruitment patterns. Seasonal fluctuations have to be considered when analysing short-term changes in the cornmunity as such fluctuations are synchronized with the natural history of the species, making it difficult to interpret short-term variations in isolation.Se utilizó una red de arrastre para evaluar la variación diaria y mareal del ensamble de peces en la playa de Pontal, sur de Brasil. Se encontró la mayor riqueza de especies durante la noche mientras que la abundancia, peso y riqueza (indicadores de la comunidad fueron influenciados por la marea. Las muestras de marea creciente fueron las más representativas debido probablemente a los movimientos costeros con fines alimentarios; sin embargo, las menores capturas estuvieron asociadas a pleamares debido a la evasion a la red, indicando que los muéstreos en estas condiciones son poco informativos. Los clupeidos fueron los peces que más variaron durante un periodo de 24 h; la ocurrencia nocturna de A. tricolor y el agrupamiento matutino de Harengula clupeola, Anchoa parva and Sardinella brasiliensis sugieren distintas estrategias en la evasion de los depredadores diurnos. La morfología del fondo asociada con la marea, puede haber influenciado el comportamiento de algunas especies, facilitándoles el agrupamiento costero. Además de haber sido capturadas por la noche, la ocurrencia de Menticirrhus littoralis, Pomadasys corvinaefórmis, Umbrina coroides and Hyporhamphus unifasciatus indicó la repartición espacial del nicho según el estado de la marea. Aunque no evaluadas correctamente, las fluctuaciones temporales pueden reflejar los patrones específicos de reclutamiento; la estacionalidad debe ser incluida cuando se estudian desplazamientos de corto plazo en la comunidad debido a su sincronización con la historia natural de las especies, haciendo que las variaciones de corto plazo sean difíciles de interpretar por sí solas.

  5. Facilitating lifelong learning with OpenU

    NARCIS (Netherlands)

    Rubens, Wilfred; Counotte, Anda

    2012-01-01

    Rubens, W., & Counotte, A. (2012). Facilitating lifelong learning with OpenU. In R. Jacobi, & N. van der Woert (Eds.), Trendreport Open Educational Resources 2012 (pp. 22-26). Utrecht: SURF Foundation - Special Interest Group Open Educational Resources SURF.

  6. Liquid Ice Surfers--The Construction of Surfer Identities in Norway

    Science.gov (United States)

    Langseth, Tommy

    2012-01-01

    Surfing is getting increasingly popular in Norway as well as other countries that have a coastline with rideable waves. As surfing gains in popularity, however, the boundaries of the surfing subculture become increasingly guarded. Through ethnography and qualitative interviews, this study examines identity construction on an individual and group…

  7. Trends in chronic marine oil pollution in Danish waters assessed using 22 years of beached bird surveys.

    Science.gov (United States)

    Larsen, Jørn Lennart; Durinck, Jan; Skov, Henrik

    2007-09-01

    Beached bird surveys provide an important tool for monitoring the level of oil pollution at sea, which is the most significant observable cause of death for a large number of waterbird species and pose a serious threat to wintering seabird populations. Linear regression analyses of oil rates from the Danish 22 year dataset show a decline in the oil pollution level in offshore areas of the eastern North Sea and Skagerrak and in near-shore parts of the Kattegat; but a worsening in the offshore areas of the Kattegat. These results raise concern for species such as common scoter, velvet scoter, eider and razorbill, for which the Kattegat serves as a globally important wintering area. It is recommended that surveillance for oil spills is intensified in inner Danish waters, and that action is taken to make responses towards offenders faster, and penalties for oil seepage higher.

  8. Hand gesture recognition based on combining Hu moments and BoF-SURF support vector machine%融合Hu矩与BoF-SURF支持向量机的手势识别

    Institute of Scientific and Technical Information of China (English)

    SUI Yun-heng; GUO Yuan-shu

    2014-01-01

    基于尺度不变特征变换的特征包(BoF-SIFT)支持向量机的分类方法具有较好的手势识别效果,但是计算复杂度高、实时性较差。为此,提出了融合Hu矩与基于快速鲁棒特征的特征包(BoF-SURF)支持向量机(SVM)的手势识别方法。特征包模型中用快速鲁棒性特征(SURF)算法替换尺度不变特征变换(SIFT)算法提取特征,提高了实时性,并引入Hu矩描述手势全局特征,进一步提高识别率。实验结果表明,算法无论是实时性还是识别率都要高于BoF-SIFT支持向量机方法。%The classification method using bag of features-scale invariant feature transformation(BoF-SIFT) support vector machine got a better result on hand gesture recognition. However, it had a high computational complexity which results in the worse real-time p

  9. Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 3: developmental changes in spermatid flagellum and cytoplasmic droplet and interaction of sperm with the zona pellucida and egg plasma membrane.

    Science.gov (United States)

    Hermo, Louis; Pelletier, R-Marc; Cyr, Daniel G; Smith, Charles E

    2010-04-01

    Spermiogenesis constitutes the steps involved in the metamorphosis of spermatids into spermatozoa. It involves modification of several organelles in addition to the formation of several structures including the flagellum and cytoplasmic droplet. The flagellum is composed of a neck region and middle, principal, and end pieces. The axoneme composed of nine outer microtubular doublets circularly arranged to form a cylinder around a central pair of microtubules is present throughout the flagellum. The middle and principal pieces each contain specific components such as the mitochondrial sheath and fibrous sheath, respectively, while outer dense fibers are common to both. A plethora of proteins are constituents of each of these structures, with each playing key roles in functions related to the fertility of spermatozoa. At the end of spermiogenesis, a portion of spermatid cytoplasm remains associated with the released spermatozoa, referred to as the cytoplasmic droplet. The latter has as its main feature Golgi saccules, which appear to modify the plasma membrane of spermatozoa as they move down the epididymal duct and hence may be partly involved in male gamete maturation. The end product of spermatogenesis is highly streamlined and motile spermatozoa having a condensed nucleus equipped with an acrosome. Spermatozoa move through the female reproductive tract and eventually penetrate the zona pellucida and bind to the egg plasma membrane. Many proteins have been implicated in the process of fertilization as well as a plethora of proteins involved in the development of spermatids and sperm, and these are high lighted in this review.

  10. Distribution and abundance of larval japanese grenadier anchovy Coilia nasus in the surf zone of the Yangtze River estuary%长江口沿岸碎波带刀鲚仔稚鱼的数量分布

    Institute of Scientific and Technical Information of China (English)

    葛珂珂; 钟俊生; 吴美琴; 赵盛龙; 张冬良

    2009-01-01

    2007年5-10月,每月大潮期间在长江口沿岸碎波带13个站位用小型拖网各采样1次.195次拖网共采获刀鲚(Coilia nasus)仔稚鱼9 358尾,体长范围为3.0~61.2mm,优势体长为6.0~25.0 mm,以10.0~16.0 mm的弯曲期和13.0~21.0 mm的后弯曲期仔鱼为主.采获数量以7月最高,占总数55.0%,主要分布在长江口南支和北支上游,有3个站位(St.5、St.7、St.10)数量较高.其中有1个站位(St.7)刀鲚仔鱼的平均体长按月呈递增趋势,表明刀鲚仔稚鱼有利用沿岸碎波带作为早期生长场所的习性.根据刀鲚仔稚鱼在长江口沿岸碎波带分布和数量变动的调查结果,结合目前刀鲚成鱼资源量贫乏的现状,建议有关部门限制鳗苗定置网等作业,并加强对沿岸碎波带保育场的保护.

  11. Hydrodynamic and Sediment Transport Model Application for OSAT3 Guidance: Surf-zone integrated alongshore potential flux for oil-sand balls of varying sizes weighted by probability of wave scenario occurrence

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey has developed a method for estimating the mobility and potential alongshore transport of heavier-than-water sand and oil agglomerates...

  12. Hydrodynamic and Sediment Transport Model Application for OSAT3 Guidance: Surf-zone integrated alongshore potential flux for oil-sand balls of varying sizes weighted by probability of wave scenario occurrence

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey has developed a method for estimating the mobility and potential alongshore transport of heavier-than-water sand and oil agglomerates...

  13. The impact of ocean acidification on the early life stages of surf clams and the interactive effects of feeding and temperature from laboratory experiment studies from 2011-07-12 to 2012-06-17 (NODC Accession 0123314)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains laboratory experiment data that were collected to examine the effects of ocean acidification on the Atlantic surfclam, Spisula...

  14. Surfing for Data: A Gathering Trend in Data Storage Is the Use of Web-Based Applications that Make It Easy for Authorized Users to Access Hosted Server Content with Just a Computing Device and Browser

    Science.gov (United States)

    Technology & Learning, 2005

    2005-01-01

    In recent years, the widespread availability of networks and the flexibility of Web browsers have shifted the industry from a client-server model to a Web-based one. In the client-server model of computing, clients run applications locally, with the servers managing storage, printing functions, and network traffic. Because every client is…

  15. Multibeam collection for S-1-00-OR: Multibeam data collected aboard Surf Surveyor from 2000-07-28 to 2000-08-03, departing from Unknown Port and returning to Unknown Port

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is part of a larger set of data called the Multibeam Bathymetry Database (MBBDB) where other similar data can be found at...

  16. Comment on "Properly interpreting scanning tunneling microscopy images: the Cu(1 0 0)-c(2 × 2)N surface revisited" by T.E. Wofford, S.M. York and F.M. Leibsle [Surf. Sci. 522 (2003) 47

    Science.gov (United States)

    Driver, S. M.; Woodruff, D. P.

    2003-08-01

    The rationale for attributing the protrusions in STM images of Cu(1 0 0)c(2 × 2)-N to Cu atoms in a symmetry-reducing adsorbate-induced surface layer rumpling is restated, and the alternative explanation by Wofford et al. is refuted.

  17. Caracterização quali-quantitativa do fitoplâncton da zona de arrebentação de uma praia amazônica Phytoplankton of the surf zone in Amazon beach

    Directory of Open Access Journals (Sweden)

    Jislene Brito Matos

    2012-12-01

    Full Text Available A estrutura da comunidade fitoplanctônica da praia da Princesa (Ilha de Maiandeua foi estudada durante um ciclo nictemeral nos meses de novembro/08, março/09, junho/09 e setembro/09, de modo a verificar os efeitos de algumas variáveis ambientais sobre esta comunidade. O microfitoplâncton da praia da Princesa esteve representado por 98 táxons, com predomínio das diatomáceas, seguidas dos dinoflagelados e cianofíceas. Nas amostras qualitativas, Coscinodiscus perforatus Ehrenberg se destacou como abundante nos meses de março (45,6% e junho (45,1%, enquanto que a análise quantitativa revelou Dimeregramma minor (Gregory Ralfs como dominante, principalmente, em novembro (82,0% e setembro (83,0%. A biomassa fitoplanctônica (clorofila-a foi significativamente mais elevada em março (U= 0,0; pThe structure of the phytoplankton community of Princesa beach (Maiandeua island was investigated during a nyctemeral cycle in the months of November/08, March/09, June/09 and September/09 to verify the effects of certain environmental variables on this community. The microphytoplankton of Princesa beach was represented by 98 taxa with the dominance of the diatoms, which were followed by the dinoflagellates and cyanophytes. The qualitative study revealed that Coscinodiscus perforatus Ehrenberg was abundant in March (45.6% and June (45.1%, whereas in the quantitative analysis Dimeregramma minor (Gregory Ralfs was dominant, mainly in November/08 (82.0% and September/09 (83.0%. Biomass (chlorophyll-a content was significantly higher in March/08 (U= 0.0; p <0.05. The average total phytoplankton density was significantly higher during the rainy period (F= 6.2; p< 0.05, mainly in June (1,223 ±110 x 10³ cell L-1. K-dominance curves showed a gradual decrease in diversity along the dry period. Non-Metric Multidimensional Scaling analysis (MDS revealed the formation of three groups, whereas Principal Component Analysis (PCA showed that salinity and turbidity were the main variables that defined the components. Princesa beach is a dynamic environment where ressuspension processes promote the shift between phytoplankton and phytobenthos populations. High rainfall and the increase in river runoff were responsible for an increase in nutrient availability contributing to the development of phytoplankton, mainly during the rainy period.

  18. Automated curve matching techniques for reproducible, high-resolution palaeomagnetic dating

    Science.gov (United States)

    Lurcock, Pontus; Channell, James

    2016-04-01

    High-resolution relative palaeointensity (RPI) and palaeosecular variation (PSV) data are increasingly important for accurate dating of sedimentary sequences, often in combination with oxygen isotope (δ18O) measurements. A chronology is established by matching a measured downcore signal to a dated reference curve, but there is no standard methodology for performing this correlation. Traditionally, matching is done by eye, but this becomes difficult when two parameters (e.g. RPI and δ18O) are being matched simultaneously, and cannot be done entirely objectively or repeatably. More recently, various automated techniques have appeared for matching one or more signals. We present Scoter, a user-friendly program for dating by signal matching and for comparing different matching techniques. Scoter is a cross-platform application implemented in Python, and consists of a general-purpose signal processing and correlation library linked to a graphical desktop front-end. RPI, PSV, and other records can be opened, pre-processed, and automatically matched with reference curves. A Scoter project can be exported as a self-contained bundle, encapsulating the input data, pre-processing steps, and correlation parameters, as well as the program itself. The analysis can be automatically replicated by anyone using only the resources in the bundle, ensuring full reproducibility. The current version of Scoter incorporates an experimental signal-matching algorithm based on simulated annealing, as well as an interface to the well-established Match program of Lisiecki and Lisiecki (2002), enabling results of the two approaches to be compared directly.

  19. Base-line investigations of birds in relation to an offshore wind farm at Horns Rev: results and conclusions 2000/2001

    Energy Technology Data Exchange (ETDEWEB)

    Kjaer Christensen, T.; Clausager, I.; Krag Petersen, I. [NERI, Dept. of Coastal Zone Ecology, Roskilde (Denmark)

    2001-07-01

    This report presents the combined results of two years of base-line investigations of birds performed during August 1999 - April 2001 in relation to the proposed construction of an offshore wind farm at Horns Rev in the Danish part of the North Sea ca 14 km southwest of Blaevandshuk. Based on the distribution of the most abundant bird species recorded during 13 aerial surveys, there were no indications that the wind farm area was of any particular importance to the birds' exploitation of the Horns Rev area. Fish-eating species like divers, gannet, terns, auks and gulls generally showed scattered and variable distributions, occurring in the areas north and south of Horns Rev, and with low numbers occurring on the reef proper and within the planned wind farm area. The distribution of benthic foraging species, eider and common scoter, showed that they mainly exploited the coastal parts of the area off Blaevandshuk and Skallingen, although the common scoter was found in relatively high numbers on the southeast slopes of Horns Rev and within the wind farm area in the April 2001 survey. Preference analyses of bird exploitation of the Horns Rev area showed that if the birds completely avoid the wind farm area after erection of the wind turbines, this will affects less than 1% of the different species, except divers of which 1.65% will be affected. If the birds avoid the wind farm area and an adjacent 4 km zone (worst case scenario), it is estimated to affect 11% of the common scoter, 10% of the gannet, 7-9% of the divers, alcids and velvet scoter and 0-6% of the remaining species. The seasonal occurrence of the recorded species was fully comparable to the seasonal occurrence of these species recorded at Blaevandshuk since 1963. Year-to-year variation in abundance between the seasons August 1999 - April 2000 and August 2000 - April 2001 was mainly found in species that migrate through the Horns Rev area (terns, gannet, kittiwake), and with less pronounced variation in

  20. Base-line investigations of birds in relation to an offshore wind farm at Horns Rev: results and conclusions 2000/2001

    Energy Technology Data Exchange (ETDEWEB)

    Kjaer Christensen, T.; Clausager, I.; Krag Petersen, I. [NERI, Dept. of Coastal Zone Ecology, Roskilde (Denmark)

    2001-07-01

    This report presents the combined results of two years of base-line investigations of birds performed during August 1999 - April 2001 in relation to the proposed construction of an offshore wind farm at Horns Rev in the Danish part of the North Sea ca 14 km southwest of Blaevandshuk. Based on the distribution of the most abundant bird species recorded during 13 aerial surveys, there were no indications that the wind farm area was of any particular importance to the birds' exploitation of the Horns Rev area. Fish-eating species like divers, gannet, terns, auks and gulls generally showed scattered and variable distributions, occurring in the areas north and south of Horns Rev, and with low numbers occurring on the reef proper and within the planned wind farm area. The distribution of benthic foraging species, eider and common scoter, showed that they mainly exploited the coastal parts of the area off Blaevandshuk and Skallingen, although the common scoter was found in relatively high numbers on the southeast slopes of Horns Rev and within the wind farm area in the April 2001 survey. Preference analyses of bird exploitation of the Horns Rev area showed that if the birds completely avoid the wind farm area after erection of the wind turbines, this will affects less than 1% of the different species, except divers of which 1.65% will be affected. If the birds avoid the wind farm area and an adjacent 4 km zone (worst case scenario), it is estimated to affect 11% of the common scoter, 10% of the gannet, 7-9% of the divers, alcids and velvet scoter and 0-6% of the remaining species. The seasonal occurrence of the recorded species was fully comparable to the seasonal occurrence of these species recorded at Blaevandshuk since 1963. Year-to-year variation in abundance between the seasons August 1999 - April 2000 and August 2000 - April 2001 was mainly found in species that migrate through the Horns Rev area (terns, gannet, kittiwake), and with less pronounced variation in

  1. Effect of surfactant-coated iron oxide nanoparticles on the effluent water quality from a simulated sequencing batch reactor treating domestic wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Sangchul, E-mail: sangchul.hwang@upr.edu [Department of Civil Engineering, University of Puerto Rico, Mayaguez, PR 00681 (Puerto Rico); Martinez, Diana [Department of Civil Engineering, University of Puerto Rico, Mayaguez, PR 00681 (Puerto Rico); Perez, Priscilla [Department of Biology, University of Puerto Rico, Mayaguez, PR 00681 (Puerto Rico); Rinaldi, Carlos [Department of Chemical Engineering, University of Puerto Rico, Mayaguez, PR 00681 (Puerto Rico)

    2011-12-15

    This study was conducted to evaluate the effect of commercially available engineered iron oxide nanoparticles coated with a surfactant (ENP{sub Fe-surf}) on effluent water quality from a lab-scale sequencing batch reactor as a model secondary biological wastewater treatment. Results showed that {approx}8.7% of ENP{sub Fe-surf} applied were present in the effluent stream. The stable presence of ENP{sub Fe-surf} was confirmed by analyzing the mean particle diameter and iron concentration in the effluent. Consequently, aqueous ENP{sub Fe-surf} deteriorated the effluent water quality at a statistically significant level (p < 0.05) with respect to soluble chemical oxygen demand, turbidity, and apparent color. This implied that ENP{sub Fe-surf} would be introduced into environmental receptors through the treated effluent and could potentially impact them. - Highlights: > Surfactant-coated engineered iron oxide nanoparticles (ENP{sub Fe-surf}) were assessed. > Effluent quality was analyzed from a sequencing batch reactor with ENP{sub Fe-surf}. > {approx}8.7% of ENP{sub Fe-surf} applied was present in the effluent. > ENP{sub Fe-surf} significantly (p < 0.05) deteriorated the effluent water quality. > Stable fraction of ENP{sub Fe-surf} will be introduced into environmental receptors. - Stable presence of surfactant-coated engineered iron oxides nanoparticles deteriorated the effluent water quality at a statistically significant level (p < 0.05).

  2. Nearshore bars and the break-point hypothesis

    Science.gov (United States)

    Sallenger, A.H.; Howd, P.A.

    1989-01-01

    The set of hypotheses calling for bar formation at the break point was tested with field data. During two different experiments, waves were measured across the surf zone coincident with the development of a nearshore bar. We use a criterion, based on the wave height to depth ratio, to determine the offshore limit of the inner surf zone. During the first experiment, the bar became better developed and migrated offshore while remaining well within the inner surf zone. During the second experiment, the surf zone was narrower and we cannot rule out the possibility of break point processes contributing to bar development. We conclude that bars are not necessarily coupled with the break point and can become better developed and migrate offshore while being in the inner surf zone landward from initial wave breaking in the outer surf zone. ?? 1989.

  3. A new statistical model of wave heights based on the concept of wave breaking critical zone

    Institute of Scientific and Technical Information of China (English)

    YANG Jiaxuan; LI Xunqiang; ZHU Shouxian; ZHANG Wenjing; WANG Lei

    2015-01-01

    When waves propagate from deep water to shallow water, wave heights and steepness increase and then waves roll back and break. This phenomenon is called surf. Currently, the present statistical calculation model of surf was derived mainly from the wave energy conservation equation and the linear wave dispersion relation, but it cannot reflect accurately the process which is a rapid increasing in wave height near the broken point. So, the concept of a surf breaking critical zone is presented. And the nearshore is divided as deep water zone, shallow water zone, surf breaking critical zone and after breaking zone. Besides, the calculation formula for the height of the surf breaking critical zone has founded based on flume experiments, thereby a new statistical calculation model on the surf has been established. Using the new model, the calculation error of wave height maximum is reduced from 17.62% to 6.43%.

  4. Status report of seabird surveys at Horns Rev, 2000-2001

    Energy Technology Data Exchange (ETDEWEB)

    Kjaer Christensen, T.; Clausager, I.; Krag Petersen, I. [NERI, Dept. of Coastal Zone Ecology, Roskilde (Denmark)

    2002-07-01

    The present report presents the results of three bird surveys conducted in the Horns Rev area during the second half of 2001. Due to poor weather conditions in December 2001, the last survey was, however, performed on 7 January 2002. The surveys are part of the base-line investigations of birds performed in relation to the proposed construction of an offshore wind farm at Horns Rev in the Danish part of the North Sea ca 14 km southwest of Blaevandshuk. The results of the surveys during August 2001 - January 2002 are presented together with the results obtained during the period August 2000 - April 2001, and are also compared to results obtained during the period August 1999 - April 2000. Based on the distribution of the most abundant bird species recorded during 16 aerial surveys performed during August 1999 - January 2002, there were no indications that the wind farm area was of any particular importance to the birds' exploitation of the Horns Rev area. Fish-eating species like divers, gannet, terns, auks and gulls generally showed scattered and variable distributions, mainly occurring in the areas north and south of Horns Rev, and with low numbers on the reef proper and within the planned wind farm area. The distribution of benthic foraging species, eider and common Scoter, showed that they mainly exploited the coastal parts of the area off Blaevandshuk and Skallingen, although common scoter was found in relatively high numbers on the southeast slopes of the Horns Rev and within the wind farm area in the April 2001 survey. Common scoters occurred in very high numbers in January 2002. This was probably related to increased immigration of birds from the inner Danish waters during a cold period in late December 2001. Preference analyses of bird exploitation of the Horns Rev area showed that if the birds completely avoid the wind farm area after erection of the wind turbines, this will affect less than 1% of the various species, except divers where 1.58% will be

  5. Microscopic Control of Semiconductor Surface Oxidation.

    Science.gov (United States)

    1985-04-15

    Cros, J. Derrien, and F. Salvan, Surf. Sci. 110, 471 (1981), J. Derrien and F. Ringeisen, Surf. Sci. 124, L35 (1983). 2. A.D. Katnani, P. Perfetti , Te...Riedel, M. Turowski, G. Margaritondo, P. Perfetti , and C. Quaresima, unpublished. 17. A. Cros, J. Phys. (Paris) 44, 707 (1983) and references therein. 18

  6. Mobile Devices and Apps as Accelerators for OER

    NARCIS (Netherlands)

    De Vries, Fred; Thuss, Frank

    2013-01-01

    De Vries, F., & Thuss, F. (2013). Mobile Devices and Apps as accelerators for OER. In R. Jacobi, H. Jelgerhuis, & N. Van der Woert (Eds.), Trendreport Open Educational Resources 2013 (pp. 49-52). Utrecht: SURF Foundation - Special Interest Group Open Educational Resources SURF.

  7. 77 FR 9850 - Safety Zone; 2012 Mavericks Invitational, Half Moon Bay, CA

    Science.gov (United States)

    2012-02-21

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA08 Safety Zone; 2012 Mavericks Invitational, Half Moon Bay... temporary safety zone in support of the Mavericks Surf Competition. This temporary safety zone will... process would be completed. Because of the dangers posed by the surf conditions during the 2012 Mavericks...

  8. Arabidopsis CDS blastp result: AK120540 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK120540 J013129G19 At1g16430.1 surfeit locus protein 5 family protein / SURF5 family protein similar to Sur...feit locus protein 5 (surf5) (SP:Q62276) [Mus musculus]; similar to Surfeit locus protein 5 (SP:Q15528) [Homo sapiens] 2e-40 ...

  9. Arabidopsis CDS blastp result: AK241630 [KOME

    Lifescience Database Archive (English)

    Full Text Available / SURF5 family protein similar to Surfeit locus protein 5 (surf5) (SP:Q62276) [Mus musculus]; similar to Surfeit locus protein 5 (SP:Q15528) [Homo sapiens] 5e-40 ... ...AK241630 J065187N12 At1g16430.1 68414.m01965 surfeit locus protein 5 family protein

  10. Learning paths and OER: trends and opportunities

    NARCIS (Netherlands)

    Janssen, José; Berlanga, Adriana; Koper, Rob

    2013-01-01

    Janssen, J., Berlanga, A. J., & Koper, R. (2013). Learning paths and OER: trends and opportunities. In R. Jacobi, H. Jelgerhuis, & N. van der Woert (Eds.), Trendreport Open Educational Resources 2013 (pp. 76-80). Utrecht: SURF Foundation - Special Interest Group Open Educational Resources SURF. Fina

  11. Nuclear gene defects in mitochondrial disorders.

    Science.gov (United States)

    Zeviani, M; Corona, P; Nijtmans, L; Tiranti, V

    1999-12-01

    An increasing number of nuclear genes have been associated with abnormalities of oxidative phosphorylation and mitochondrial disorders. The protein products of these genes can be grouped into three categories: structural components of the respiratory chain, factors influencing the structural integrity or the copy number of mitochondrial DNA, and proteins which control the formation, assembly and turnover of the respiratory complexes. Loss-of-function mutations in SURF-1, a gene belonging to the third category, have been associated with Leigh syndrome with cytochrome c oxidase deficiency. Mature Surf-1 protein (Surf-1p) is a 30 kDa hydrophobic polypeptide whose function is still unknown. Using antibodies against human Surf-1p, we demonstrated that this protein is imported into mitochondria as a larger precursor. The same analysis revealed that no protein is present in cell lines harboring loss-of-function mutations of SURF-1, regardless of their type and position. We also generated several constructs with truncated or partially deleted SURF-1 cDNAs. None of these constructs, expressed into SURF-1 null mutant cells, were able to rescue the COX phenotype, suggesting that different regions of the protein are all essential for function. Finally, experiments based on 2D gel electrophoresis indicated that assembly of COX in SURF-1 null mutants is blocked at an early step, most likely before the incorporation of subunit II in the nascent intermediates composed of subunit I alone or subunit I plus subunit IV.

  12. Evaluation of Barrier Cable Impact Pad Materials

    Science.gov (United States)

    1988-03-01

    ACTUAL BATCH DATA CU MATERIAL SOLID VOLUME SAT. SURF DRY SAT. . O,- DRY WATER ACT’.AL CU FT/BATCH BATCH WT. LB FACTOR EATCl ,9 CORRECTION. LB 1ATC. -T...POZZDOTHER CEMENT PROPORTIONS CALCULATED BATCH DATA (I CU YO) ACTUAL BATCH CATA CU =T SOLID VOLUME SAT. SURF DRY SAT. 3, DRY WATER MATERIAL CU FT

  13. Examining Risk-Taking Behavior and Sensation Seeking Requirement in Extreme Athletes

    Science.gov (United States)

    Agilonu, Ali; Bastug, Gulsum; Mutlu, Tonguc Osman; Pala, Adem

    2017-01-01

    Extreme sports are sport branches which include actions, adventures, risks and difficulties more rather than other sports. Special materials are used in sport branches such as surfing, kite surfing, sailing, snowboarding, paragliding, diving, mountaineering, motor sports and adrenaline release is more rather than in other sport branches. On the…

  14. Mobile Devices and Apps as Accelerators for OER

    NARCIS (Netherlands)

    De Vries, Fred; Thuss, Frank

    2013-01-01

    De Vries, F., & Thuss, F. (2013). Mobile Devices and Apps as accelerators for OER. In R. Jacobi, H. Jelgerhuis, & N. Van der Woert (Eds.), Trendreport Open Educational Resources 2013 (pp. 49-52). Utrecht: SURF Foundation - Special Interest Group Open Educational Resources SURF.

  15. Effect of surfactant-coated iron oxide nanoparticles on the effluent water quality from a simulated sequencing batch reactor treating domestic wastewater.

    Science.gov (United States)

    Hwang, Sangchul; Martinez, Diana; Perez, Priscilla; Rinaldi, Carlos

    2011-12-01

    This study was conducted to evaluate the effect of commercially available engineered iron oxide nanoparticles coated with a surfactant (ENP(Fe-surf)) on effluent water quality from a lab-scale sequencing batch reactor as a model secondary biological wastewater treatment. Results showed that ~8.7% of ENP(Fe-surf) applied were present in the effluent stream. The stable presence of ENP(Fe-surf) was confirmed by analyzing the mean particle diameter and iron concentration in the effluent. Consequently, aqueous ENP(Fe-surf) deteriorated the effluent water quality at a statistically significant level (p < 0.05) with respect to soluble chemical oxygen demand, turbidity, and apparent color. This implied that ENP(Fe-surf) would be introduced into environmental receptors through the treated effluent and could potentially impact them.

  16. Aetiology of injuries and the need for protective equipment for surfers in the UK.

    Science.gov (United States)

    Woodacre, Timothy; Waydia, Shree Eesh; Wienand-Barnett, Sophie

    2015-01-01

    Surfing is a popular UK water-sport. Previous studies investigating surfing injuries have been principally based on trauma from large waves and reef breaks in the US and Australia. Subsequent conclusions and recommendations for the use of protective equipment in surfing may therefore not be relevant in the UK. This study examines the aetiology of surfing injuries in the UK. Data was collected in 2012 using a web-based survey distributed to UK surfing clubs. Surfers recorded time/experience as a surfer, number of episodes spent surfing per month, different breaks surfed and type, frequency and method of any injuries sustained whilst surfing in the UK, including treatment received. Completed surveys were obtained from 130 individuals, M:F division 85:45, median age 28 (range 17-65). 122 surfers reported a total of 335 injuries. Head injuries were the most common (24%) followed by ankle (19%), knee (13%), back (10%), hand/wrist (9%), elbow/shoulder (7%), trunk (7%), neck (4%), hip (4%) and genitalia (3%) injuries. Surfers collided most often with their own boards (31%). The other collisions were with rocks/coral (15%), the sea (11%), other surf boards (10%) the sea bed (7%), other water vessels (2%) and by paddle-boards (1%). Of 327 injuries, cuts/lacerations (31%) were the commonest type of injury, followed by bruises/peri-orbital ecchymoses (24%), joint/ligament sprains (15%), muscle or tendon tears/ruptures (9%), concussion (5%), fractures (3%) and teeth injuries (1%). The remaining 8 injuries were not categorized. 65% of the surfers never required professional medical treatment for their differing injuries. There were no skull fractures and no head injuries required neurosurgical intervention. Surfing injuries in the UK are common. They appear of a similar aetiology to those reported in the literature in countries with a high surfing population, but generally of a lower severity, with few requiring professional treatment, hospital admission or operative

  17. Comment on "Nanosecond laser textured superhydrophobic metallic surfaces and their chemical sensing applications" by Duong V. Ta, Andrew Dunn, Thomas J. Wasley, Robert W. Kay, Jonathan Stringer, Patrick J. Smith, Colm Connaughton, Jonathan D. Shephard (Appl. Surf. Sci. 357 (2015) 248-254)

    Science.gov (United States)

    Boinovich, L. B.; Emelyanenko, A. M.; Emelyanenko, K. A.; Domantovsky, A. G.; Shiryaev, A. A.

    2016-08-01

    Nowadays the problem of design of durable ecologically friendly superhydrophobic surfaces is of great importance for science and technology. A recent paper in Applied Surface Science reports the method of fabricating the superhydrophobic metallic surfaces by infrared nanosecond laser surface texturing without using hydrophobic agents. Since this method of surface texturing can be considered as one of the most suitable for various industrial applications, the nature of superhydrophobic state of surfaces produced by laser texturing in the abovementioned paper deserves to be analyzed in detail. Authors of the commented paper attributed the change in wettability to the partial deoxidation of CuO into Cu2O on the surface during storage in atmosphere. However, such interpretation of the results contradicts to the basic notions in the theory of wetting and to more accurate and detailed data. In our Comment we discuss these contradictions point by point.

  18. RESEARCHES ON THE THERMAL BEHAVIORS AND SURF ACIAL COMPOSITION FOR POLYETHER POLYURETHANES/NANO-CARBON FIBER BLEND%聚醚型聚氨酯/纳米炭纤维共混体系的热行为和表面分析

    Institute of Scientific and Technical Information of China (English)

    许海燕; 杨子彬; 孔桦; 陆颂芳; 彭屹

    2001-01-01

    Polyether polyurethanes is one of the most important polymeric biomedical materials with acceptable blood compatibility and good mechanical properties. It is very useful in manufacturing of intervention al catheters and artificial organs contacting with blood, in this paper, the pol yether polyurethane was blended with certain amount of nano-carbon fibers to fo rm a novel composite system. The thermal behaviors and surfacial compositions of the blend were analyzed and discussed through DSC and ESCA. The results show th at there are fews of changes taken place both in microphase structure of the ble nd and in its surfacial composition, the content of hard domain increased and the ratio of N/O on the blend surface were increased from 1/14.8 to 1/16.3, com pared with the polyether polyurethane control, the Tg of the composite were increased too.%采用纳米炭纤维(nanoCF)与聚醚型聚氨酯(SE PU)共混复合,通过红外光谱、示差扫描量热分析及表面电子能谱分析,对该共混体系的热行 为和表面化学组成进行了初步的表征与探讨。实验结果表明,共混体系中聚醚型聚氨酯的硬 段微区含量增大,聚醚软段在材料表面的富集程度也得到提高。

  19. 腥风血雨乱世顶风破浪稳市——2008年第1季度国际金融反思与判断%A Troubled Time with Reactionary Reign of Terror, Bold Enough to Surf for A Stabilized Market——Introspection and Judgment of International Finance in the 1st Quarter of 2008

    Institute of Scientific and Technical Information of China (English)

    谭雅玲

    2008-01-01

    2008年第1季度,国际金融市场经历了不平常的发展阶段.伴随美国次贷问题的继续恶化,国际金融市场价格压力逐渐扩散为金融体系的风险.在市场恐慌心理蔓延和货币政策应对存在错觉的情况下,国际金融市场价格错落复杂并震荡下跌,并且可能潜藏金融资产流失的风险.2008年第1季度,中国经济金融已经处于特别关注的风险阶段,集中体现在人民币汇率问题上.2008年,国际金融市场发展趋势的主导因素依然是美元利率,国际金融市场将充满风险,但政策应对与政治需求将使风险处于可控之中.

  20. “天之下”与“海之下” 斯蒂文·霍尔的法国比亚里茨海洋与冲浪博物馆%"Under the Sky"/"Under the Sea"Steven Holl's Cite de I'Oceanet du Surf,Biarritz,France

    Institute of Scientific and Technical Information of China (English)

    陆轶辰

    2012-01-01

    The design concept is based on the phrases"under the sky"/"under the sea".The shape of the building is intended to create a central gathering plaza,open to the sky and the sea,with the horizon at the distance.This"Place de I'Ocean",with its curved,"under the sky"shape,gives character to the main exhibition space,while the convex structured ceiling forms the "under the sea" shape.Thus,the concept generates a unique profile and form for the building and through its insertion and efficient site utilization the project integrates seamlessly into the surrounding landscape. The dynamically curved underside provides a surface onto which films and video exhibitions will be projected, creating spaces enlivened by plays of light and images.%文章介绍了比亚里茨海洋与冲浪博物馆的建筑设计的初始概念"天之下"与"海之下"。"天之下"指的是比亚里茨海洋与冲浪博物馆的建筑形态所塑造的一个向天空和大海展开的供人群聚集的广场,广场下,凸起的屋顶结构则铸造了"海之下"的形态,由渐变的动态曲面形态构成展览空间的特质。这个概念创造了一个独特的形态,并通过对场地的有效利用,形成了与周边环境的无缝衔接。

  1. Estudo comparativo e variação sazonal da ictiofauna na zona entremarés do Mar Casado-Guarujá e Mar Pequeno-São Vicente, SP Comparative study and seasonal variations of the ichthyofauna of the surf zone in Mar Casado-Guaruja and Mar Pequeno-São Vicente, SP

    Directory of Open Access Journals (Sweden)

    Alfredo Martins Paiva Filho

    1987-01-01

    Full Text Available Através de arrastos mensais de praia, realizados com rede de calao na região do Mar Casado-Guarujá e Mar Pequeno-São Vicente, SP, de maio de 1984 a maio de 1985, foi capturado um total de 5723 exemplares de peixes pertencentes a 42 espécies. É apresentada uma lista por espécies, ocorrência sazonal e abundancia relativa por área de coleta. Em ambas as áreas poucas especies são dominantes, sendo que no Mar Casado ocorrem Trachinotus carolinus (Carangidae , juvenis de Mugilidae, Harengula clupeola (Clupeidae, Trachinotus falcatus (Carangidae e Eucinostomus melapterus (Gerreidae; no Mar Pequeno, ocorrem juvenis de Mugilidae, Xelomelaniris brasiliensis (Atherinidae, Opisthonema oglinum e Harengula Clupeola (Clupeidae. O Mar Pequeno apresenta maior riqueza de espécies, com maiores valores no numero de indivíduos e na captura por unidade de esforço, aparentemente correlacionados com a temperatura da água que é mais baixa no inverno e mais elevada no verão-outono. O índice de diversidade variou sazonalmente, não parecendo estar relacionado com os parâmetros ambientais.Through a monthly beach seine survey programme carried out in the coastal beach of Mar Casado (Guarujá-SP and in the estuarine beach of Mar Pequeno (São Vicente-SP, from May, 1984 to May, 1985, it was yielded a total of 5723 individuals of 42 species of marine and estuarine fish. A list of species, seasonal occurrence and relative abundances is presented. For each area, we found only five dominant species as: in Mar Casado, Trachinotus carolinus and T. falctus (Carangidae, juveniles of Mugilidae, Harengula clupeola (Clupeidae and Eucinostmus melanopterus (Gerreidae; in Mar Pequeno, juveniles of Mugilidae, Xenomelaniris brasilienses (Atherinidae, Opisthonema oglinum and Harengula clupeola (Clupeidae. In Mar Pequeno we found the greatest richness of species, the highest values of individuals's number, and CPUE, apparently related with water's temperature that are lower in winter and higher in summer-fall. The Shannon-Weaver Index was calculated to determine the diversity of ichthyofauna; it varies seasonally and seems not to be related with any hydrological parameters.

  2. Corrigendum to "SEM/EDX and XPS studies of niobium after electropolishing" by T. Hryniewicz, K. Rokosz, H.R. Zschommler Sandim [Appl. Surf. Sci., yyy (2012) xxx], http://dx.doi.org/10.1016/j.apsusc.2012.09.060

    Science.gov (United States)

    Hryniewicz, Tadeusz; Rokosz, Krzysztof

    2013-01-01

    This corrigendum has been prepared as a response to the comment on our recent work [1] published in this journal "Applied Surface Science"; the comment was delivered by a team of authors from Germany [2]. The objections comprised in the comment [2], formulated in 6 points, are concerned generally on our XPS results obtained on niobium after electropolishing (EP). In this response we show that there is another way possible to follow after the XPS studies and calculations performed afterwards. The indicated by the team [2] error in our results on Nb2O5 (point 5 [2]) seems to be much overestimated. Similarly, under point 6 [2] the ratio O:S = 4:1 nominal ratio of 375% for SO42-, as indicated by the team [2], may be considered as possible only theoretically. Our proof of the re-calculated and corrected results will be presented below. It is worth adding that they are based on the recently available literature [3-8].

  3. Geometry and dynamics of wave ripples in the nearshore zone of a coarse sandy beach

    Science.gov (United States)

    Masselink, G.; Austin, M. J.; O'Hare, T. J.; Russell, P. E.

    2007-10-01

    Extensive measurements of ripple characteristics and dynamics along with associated suspended sediment fluxes and hydrodynamic conditions were made in the shoaling and surf zones of a macrotidal coarse grained beach at Sennen Cove, Cornwall, England (median grain diameter 0.69 mm). Suborbital vortex ripples were observed during the majority of the study period with height ˜5 cm and length ˜35 cm. The scale and shape of the ripples did not vary significantly as the bed shear stress increased during wave shoaling and breaking. However, ripple migration rates (onshore directed) were strongly dependent on their location relative to the breakpoint, increasing from ˜0.1 cm min-1 under shoaling waves to 2 cm min-1 in the outer surf zone during low-energy conditions. Farther inside the surf zone, ripples persisted but migration rates slowed, probably owing to the presence of the offshore-directed mean flow which impedes landward migration of the ripples. Under low-wave conditions (during which measured sediment fluxes peaked around the outer surf zone and decreased through the saturated surf zone), bed form transport rates under shoaling waves were of the same magnitude as net suspended sediment fluxes but at least an order of magnitude smaller in the outer surf zone. Under high-energy conditions (during which suspended sediment fluxes in the surf zone were offshore directed owing to the presence of the seaward directed mean flow), bed form transport rates were several orders of magnitude smaller than suspended fluxes.

  4. Surfactant before the first inflation at birth improves spatial distribution of ventilation and reduces lung injury in preterm lambs.

    Science.gov (United States)

    Tingay, David G; Wallace, Megan J; Bhatia, Risha; Schmölzer, Georg M; Zahra, Valerie A; Dolan, Melinda J; Hooper, Stuart B; Davis, Peter G

    2014-02-01

    The interrelationship between the role of surfactant and a sustained inflation (SI) to aid ex utero transition of the preterm lung is unknown. We compared the effect of surfactant administered before and after an initial SI on gas exchange, lung mechanics, spatial distribution of ventilation, and lung injury in preterm lambs. Gestational-age lambs (127 days; 9 per group) received 100 mg/kg of a surfactant (Curosurf) either prior (Surf+SI) or 10 min after birth (SI+Surf). At birth, a 20-s, 35 cmH2O SI was applied, followed by 70 min of positive pressure ventilation. Oxygenation, carbon dioxide removal, respiratory system compliance, end-expiratory thoracic volume (via respiratory inductive plethysmography), and distribution of end-expiratory volume and ventilation (via electrical impedance tomography) were measured throughout. Early markers of lung injury were analyzed using quantitative RT-PCR. During the first 15 min, oxygenation, carbon dioxide removal, and compliance were better in the Surf+SI group (all P ventilation was more uniform in the Surf+SI group throughout; 50.1 ± 10.9% of total ventilation in the left hemithorax at 70 min vs. 42.6 ± 11.1% in the SI+Surf group. Surf+SI resulted in lower mRNA levels of CYR61 and EGR1 compared with SI+Surf (P mechanical and injury response to a sustained inflation and ventilation by changing surface tension of the air/fluid interface.

  5. Influence of Confocal Scanning Laser Microscopy specific acquisition parameters on the detection and matching of Speeded-Up Robust Features

    Energy Technology Data Exchange (ETDEWEB)

    Stanciu, Stefan G., E-mail: sgstanciu@gmail.com [Center for Microscopy-Microanalysis and Information Processing, University Politehnica Bucharest, Splaiul Independentei 313, sector 6, Bucharest (Romania); Hristu, Radu; Stanciu, George A. [Center for Microscopy-Microanalysis and Information Processing, University Politehnica Bucharest, Splaiul Independentei 313, sector 6, Bucharest (Romania)

    2011-04-15

    The robustness and distinctiveness of local features to various object or scene deformations and to modifications of the acquisition parameters play key roles in the design of many computer vision applications. In this paper we present the results of our experiments on the behavior of a recently developed technique for local feature detection and description, Speeded-Up Robust Features (SURF), regarding image modifications specific to Confocal Scanning Laser Microscopy (CSLM). We analyze the repeatability of detected SURF keypoints and the precision-recall of their matching under modifications of three important CSLM parameters: pinhole aperture, photomultiplier (PMT) gain and laser beam power. During any investigation by CSLM these three parameters have to be modified, individually or together, in order to optimize the contrast and the Signal Noise Ratio (SNR), being also inherently modified when changing the microscope objective. Our experiments show that an important amount of SURF features can be detected at the same physical locations in images collected at different values of the pinhole aperture, PMT gain and laser beam power, and further on can be successfully matched based on their descriptors. In the final part, we exemplify the potential of SURF in CSLM imaging by presenting a SURF-based computer vision application that deals with the mosaicing of images collected by this technique. -- Research highlights: {yields} Influence of pinhole aperture modifications on SURF detection and matching in CSLM images. {yields} Influence of photomultiplier gain modifications on SURF detection and matching in CSLM images. {yields} Influence of laser beam power modifications on SURF detection and matching in CSLM images. {yields} SURF-based automated mosaicing of CSLM images.

  6. Geographic Resources Analysis Support System (GRASS) Version 4.0 User’s Reference Manual

    Science.gov (United States)

    1992-06-01

    d.rast.arrow is designed to help users better visualize surface water flow direction, as indicated in an aspect raster map layer. There are two ways to...Laboratory (;RASS 4.1) (Summtr 199 1) U.S. Arnii (’RI, 321 r.surf.idw GRASS Reference Manual r.surfidw NAME r.surf.idw - Surface interpolation utility for...determine the interpolated value of an output raster cell. Default: 12 NOTES r.surf.idw is a surface generation utility which uses inverse distance

  7. Análisis de las características antropométricas y las diferentes manifestaciones de fuerza de miembros inferior de surfistas profesionales

    OpenAIRE

    Baldino, Juan Marcos

    2015-01-01

    El surf es un deporte popular que se practica tanto a nivel competitivo como a nivel recreacional en las playas de todo el mundo. Su objetivo radica en tratar de avanzar de pie sobre una tabla de surf por la pared de la ola que todavía no ha roto (Frisby en Méndez-Villanueva y Bishop, 2005) realizando maniobras o acciones técnicas. El surf es un deporte de habilidades abiertas. Se ejecuta en respuesta a las condiciones de un entorno incierto y cambiante como es el mar, un medio tota...

  8. Hyperbolic Mild Slope Equations with Inclusion of Amplitude Dispersion Effect: Regular Waves

    Institute of Scientific and Technical Information of China (English)

    JIN Hong; ZOU Zhi-li

    2008-01-01

    A new form of hyperbolic mild slope equations is derived with the inclusion of the amplitude dispersion of nonlinear waves. The effects of including the amplitude dispersion effect on the wave propagation are discussed. Wave breaking mechanism is incorporated into the present model to apply the new equations to surf zone. The equations are solved numerically for regular wave propagation over a shoal and in surf zone, and a comparison is made against measurements. It is found that the inclusion of the amplitude dispersion can also improve model's performance on prediction of wave heights around breaking point for the wave motions in surf zone.

  9. 77 FR 5793 - Beaches Environmental Assessment and Coastal Health Act; Availability of BEACH Act Grants

    Science.gov (United States)

    2012-02-06

    ... for swimming, bathing, surfing, or similar water contact activities. The statute explicitly excludes... award CWA section 406 grants through a non-competitive process. EPA expects to award grants to all...

  10. 75 FR 82382 - Beaches Environmental Assessment and Coastal Health Act

    Science.gov (United States)

    2010-12-30

    ... under CWA section 303(c) for use for swimming, bathing, surfing, or similar water contact activities... CWA section 406 grants through a non-competitive process. EPA expects to award grants to all eligible...

  11. Diet composition and breeding cycle of blacktail, Dip/odus sargus ...

    African Journals Online (AJOL)

    Figure 4 Monthly percentage occurrence of different reproductive phases for female and male Diplodus sargus capensis. Number of fish ..... seaweeds are ingested for their epiphytic diatoms. .... Structural and functional aspects of the surf-.

  12. Appraisal of the surficial aquifers in the Pomme de Terre and Chippewa River Valleys, western Minnesota

    Science.gov (United States)

    Soukup, W.G.; Gillies, D.C.; Myette, C.F.

    1984-01-01

    The surf icial sands in the Pomme de Terre and Chippewa River valleys in Grant, Pope, Stevens, and Swift Counties have been studied to determine the occurrence, availability, and quality of ground water in these aquifers.

  13. Laboratory Observations of Artificial Sand and Oil Agglomerates: Video and Velocity Data: Sea Floor Interaction Experiment Video (GoPro)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Weathered oil in the surf-zone after an oil spill may mix with suspended sediments to form sand and oil agglomerates (SOA). Sand and oil agglomerates may form in...

  14. Fitness and Your 13- to 18-year-old

    Science.gov (United States)

    ... various media, including watching TV, listening to music, surfing online, and playing video games. So it's no ... 12-Year-Old Steroids Preventing Children's Sports Injuries Nutrition & Fitness Center Feeding Your Child Athlete Fitness for ...

  15. Laboratory Observations of Artificial Sand and Oil Agglomerates Video and Velocity Data: Sea Floor Interaction Experiment Flow Velocity

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Weathered oil in the surf-zone after an oil spill may mix with suspended sediments to form sand and oil agglomerates (SOA). Sand and oil agglomerates may form in...

  16. Cavernous Angioma and Children

    Science.gov (United States)

    ... pong Tennis Hang gliding or surfing/windsurfing Bowling Gymnastics – Always have a spotter underneath; avoid being upside ... brain. Following this restriction may limit participation in gymnastics or in the use of some playground equipment. ...

  17. Robert Cailliau en zijn Wereldwijd Web

    CERN Document Server

    De Zitter, Aart

    1999-01-01

    Everyone among us knows the World Wide Web and "surfe" perhaps often. But who realizes that it is a Flemish invention? Robert Cailliau is his name, and it has made already for 23 years scientific research in the famous CERN

  18. Hordenloop naar open en online onderwijs

    NARCIS (Netherlands)

    Rubens, Wilfred; Schuwer, Robert

    2014-01-01

    Rubens, W. & Schuwer, R. (2014, 11 maart). Hordenloop naar open en online onderwijs. Presentatie tijdens het Symposium Open en Online Education van SURF, Ministerie van OCW, de VSNU en de Vereniging Hogescholen, Utrecht, Nederland

  19. Tourism Trends Among Generation Y in Poland

    National Research Council Canada - National Science Library

    Joanna Kowalczyk-Anioł

    2012-01-01

    .... The similarities are also visible in tourism - new, post-modernist trends, such as gap year and internet couch surfing portals, as forms of independent travel organization, are becoming more and more popular...

  20. Helping Your Child: Tips for Parents

    Science.gov (United States)

    ... game, or surfing the Internet. Playing ball or jumping rope with your children shows them that being active ... activity daily for most children. Walking fast, bicycling, jumping rope, and playing basketball, soccer, or hopscotch are all ...

  1. ASOS Surface Extinction Coefficient by STI

    Data.gov (United States)

    Washington University St Louis — ASOS_STI represents a 250-station subset of the national ASOS SURF_MET dataset. The unique feature of this data is that the visibility sensor values are available in...

  2. SC/OQ Vessel Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data tables holding information for the Surf Clam/Ocean Quahog vessel and dealer/processor logbooks (negative and positive), as well as individual tag information...

  3. Why the US Needs a Deep Domestic Research Facility: Owning rather than Renting the Education Benefits, Technology Advances, and Scientific Leadership of Underground Physics

    CERN Document Server

    Lesko, Kevin T

    2013-01-01

    I summarize the status of the Sanford Underground Research Facility in South Dakota and present connections to Energy and Intensity Frontier that benefit from the establishment of SURF and the staging of US-funded experiments in a domestic facility.

  4. Fitness and Your 13- to 18-year-old

    Science.gov (United States)

    ... interests and responsibilities. But kids who started out enjoying sports and exercise tend to stay active throughout ... on various media, including watching TV, listening to music, surfing online, and playing video games. So it's ...

  5. Laboratory Observations of Artificial Sand and Oil Agglomerates Video and Velocity Data: False-Floor Experiment Flow Velocity and Shear Stress

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Weathered oil in the surf-zone after an oil spill may mix with suspended sediments to form sand and oil agglomerates (SOA). Sand and oil agglomerates may form in...

  6. Laboratory Observations of Artificial Sand and Oil Agglomerates Video and Velocity Data: False-Floor Experiment Interpretive Video

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Weathered oil in the surf-zone after an oil spill may mix with suspended sediments to form sand and oil agglomerates (SOA). Sand and oil agglomerates may form in...

  7. Laboratory Observations of Artificial Sand and Oil Agglomerates Video and Velocity Data: Sea Floor Interaction Experiment Interpretive Video

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Weathered oil in the surf-zone after an oil spill may mix with suspended sediments to form sand and oil agglomerates (SOA). Sand and oil agglomerates may form in...

  8. MOTIVATION OF CYBERLOAFERS IN THE WORKPLACE ACROSS GENERATIONS IN INDONESIA

    National Research Council Canada - National Science Library

    Yanki Hartijasti; Nur Fathonah

    2015-01-01

    .... However, surfing for a few minutes could be stress reliever for employees. Therefore, the objective of this study is to analyze motivation of cyberloafers among Indonesian employees across generations...

  9. Open Educational Resources (1): Wat hebben we nodig?

    NARCIS (Netherlands)

    Westera, Wim

    2010-01-01

    Westera, W. (2010). Open Educational Resources (1): Wat hebben we nodig? Electronic article on SURFspace. SURF foundation: Utrecht. Retrieved december 14 at http://www.surfspace.nl/nl/Artikelen/Pages/OpenEducationalResources(1)Wathebbenwenodig.aspx

  10. Open Educational Resources (2): Hoe dekken we de kosten?

    NARCIS (Netherlands)

    Westera, Wim

    2010-01-01

    Westera, W. (2010). Open Educational Resources (2): Hoe dekken we de kosten? Electronic article on SURFspace. SURF foundation: Utrecht. Retrieved december 14 at http://www.surfspace.nl/nl/Artikelen/Pages/OpenEducationalResources(2)Hoedekkenwedekosten.aspx

  11. Bibliography of sandy beaches and sandy beach organisms on the African continent

    CSIR Research Space (South Africa)

    Bally, R

    1986-01-01

    Full Text Available This bibliography covers the literature relating to sandy beaches on the African continent and outlying islands. The bibliography lists biological, chemical, geographical and geological references and covers shallow marine sediments, surf zones off...

  12. Laboratory Observations of Artificial Sand and Oil Agglomerates: Video and Velocity Data: Sea Floor Interaction Experiment Preview Video (GoPro)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Weathered oil in the surf-zone after an oil spill may mix with suspended sediments to form sand and oil agglomerates (SOA). Sand and oil agglomerates may form in...

  13. Annual Project Report, 1978 : Fishery Management Program

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Fourteen miles of shoreline are open to surf fishing on St. Vincent National Wildlife Refuge. Freshwater fishing for largemouth bass, bluegill, and redear sunfish...

  14. Inundation, run-up heights, cross-section profiles and littoral environment along the Tamil Nadu coast after 26 th December 2004 Tsunami

    Digital Repository Service at National Institute of Oceanography (India)

    Ilangovan, D.; Jayakumar, S.; Gowthaman, R.; Tirodkar, G.; Ganesan, P.; Naik, G.N.; ManiMurali, R.; Michael, G.S.; Ramana, M.V.; Naik, K.A.

    environmental observations in the surf zone. More than 25 locations were surveyed to assess the inundation limits as well as runup heights. Cross-sectional profiles from the shoreline till the inundation limit were measured using automatic leveling equipment...

  15. Animation control of surface motion capture.

    Science.gov (United States)

    Tejera, Margara; Casas, Dan; Hilton, Adrian

    2013-12-01

    Surface motion capture (SurfCap) of actor performance from multiple view video provides reconstruction of the natural nonrigid deformation of skin and clothing. This paper introduces techniques for interactive animation control of SurfCap sequences which allow the flexibility in editing and interactive manipulation associated with existing tools for animation from skeletal motion capture (MoCap). Laplacian mesh editing is extended using a basis model learned from SurfCap sequences to constrain the surface shape to reproduce natural deformation. Three novel approaches for animation control of SurfCap sequences, which exploit the constrained Laplacian mesh editing, are introduced: 1) space–time editing for interactive sequence manipulation; 2) skeleton-driven animation to achieve natural nonrigid surface deformation; and 3) hybrid combination of skeletal MoCap driven and SurfCap sequence to extend the range of movement. These approaches are combined with high-level parametric control of SurfCap sequences in a hybrid surface and skeleton-driven animation control framework to achieve natural surface deformation with an extended range of movement by exploiting existing MoCap archives. Evaluation of each approach and the integrated animation framework are presented on real SurfCap sequences for actors performing multiple motions with a variety of clothing styles. Results demonstrate that these techniques enable flexible control for interactive animation with the natural nonrigid surface dynamics of the captured performance and provide a powerful tool to extend current SurfCap databases by incorporating new motions from MoCap sequences.

  16. Recommendations for the U.S. Coast Guard Survival Prediction Tool

    Science.gov (United States)

    2009-04-01

    raft, surf board) on the ocean. The project goal is to provide better knowledge and guidance that will enable Coast Guard (CG) mission commanders...swimming, diving, wind surfing incident). This recorded information should only be that which can be readily obtained through victim interviews or...of energy metabolism, J. Nutrition , vol. 7, pp. 497-533, 1934. H. C. Bazett and B. McGlone, Temperature gradients in the tissues in man, Am. J

  17. The Role of Surface Structural Defects in the Oxidation of A1(111) Surfaces

    Science.gov (United States)

    1988-11-01

    295. 6. J.B. Pendry and D.K. Saldin , Surf. Sci. 145 (1984) 33. 7. P.C. Stair, Rev. Sci. Instrum. 51 (1980) 132. 8. R.L. Park, J.E. Houston and D.G...Schreiner, Rev. Sci. Instrum. 42 (1971) 60. 9. T.M. Lu and M.G. Lagally, Surf. Sci. 99 (1980) 695. 10. K. Heinz, D.K. Saldin and J.B. Pendry, Phys

  18. Development of an Integrated Modeling Framework for Simulations of Coastal Processes in Deltaic Environments Using High-Performance Computing

    Science.gov (United States)

    2008-01-01

    Swash and Surf Zones, PI: Q. Jim Chen Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of...potential vorticity in the surf and swash zones, as well as the momentum exchange between the two dynamical regions. APPROACH The research project...divers for inshore countermine warfare. The modeling framework integrated with the CFD Toolkits developed at LSU will allow us to couple the hydrodynamic

  19. Modeling of Complex Coupled Fluid-Structure Interaction Systems in Arbitrary Water Depth

    Science.gov (United States)

    2009-01-01

    deterministic and stochastic environmental conditions from deep water to the surf zone. Physics- specific numerical models included in the framework...applicability of the computational framework to shallow water and the surf zone. APPROACH The approach to achieve the short term objectives is to...examples including: a pure CFD model with a backward facing step, a prescribed moving cylinder in a bounded domain, and a fluid-object interaction

  20. Soft X-Ray Photoelectron Spectroscopy Study of the Interaction of Cr with MoS2(0001)

    Science.gov (United States)

    1994-01-14

    Sailer , and M. Drinkwine, Appl. of Surf. Sci. 7 (1981) 325. 29. R.G. Musket, W. McLean, C.A. Cohnenares, D.M. Makowiecki, and WJ. Siekhaus, Appl. Surf. Sci...chemistry, laser optoelectronics, phase conjugation and coherent imaging, solar cell physics, battery electrochemistry, battery testing and evaluation...remote sensing using atmospheric radiation; solar physics, infrared astronomy, infrared signature analysis; effects of solar activity, magnetic storms

  1. Alternative pop-up for surfers with low back pain.

    Science.gov (United States)

    Hammer, Roger L; Loubert, Peter V

    2010-02-01

    Surfing is enjoyed by many people around the world. A common problem in surfers is back pain during the "take-off," specifically the "pop-up." This article describes each part of the "take-off, and introduces an alternative to the "prone pop up" - called the "knee pop-up." This alternative is a suggested technique to alleviate the stress in the lumbar spine during surfing.

  2. Bolsa Bay, California, Proposed Ocean Entrance System Study. Report 2. Comprehensive Shoreline Response Computer Simulation, Bolsa Bay, California

    Science.gov (United States)

    1990-04-01

    1980). 27. The success of the inlet channel at Agua Hedionda indicates that a stable non-navigable entrance at Bolsa Chica could be feasible provided a...dual jetty system similar to Agua Hedionda is incorporated into the design. However, structures that penetrate into the active surf zone are expected...and from the south in the summer months. i. The surfbreak rarely closes out. j. Surfing is best in the morning before the sea breeze becomes strong. 13

  3. Web Usage Mining Applied to Records of Navigation by Internet

    OpenAIRE

    Darian Horacio Grass Boada; Alejandro Rosete Suárez; Jesús Eladio Sánchez García; Valia Guerra Ones

    2013-01-01

    This paper presents a Knowledge Discovery on Databases (KDD) process applied on the internetsurfing logs at the University of Informatics Sciences. In this context, it describes a Web-UsageMining process using as data sources; the internet surfing logs stored by the proxy server, and alsodescriptive information regarding the users of such surfing service, which was provided by the institution’spersonnel management systems. Statistical, numerical and clustering techniques were combinedseeking ...

  4. A Full Hydro- and Morphodynamic Description of Breaker Bar Development

    DEFF Research Database (Denmark)

    Jacobsen, Niels Gjøl

    The present thesis considers a coupled modelling approach for hydro- and morphodynamics in the surf zone, which is based on a solution to the Reynolds Averaged Navier-Stokes (RANS) equations with a Volume of Fluid (VOF) closure for the surf tracking. The basis for the numerical approach is the su......The present thesis considers a coupled modelling approach for hydro- and morphodynamics in the surf zone, which is based on a solution to the Reynolds Averaged Navier-Stokes (RANS) equations with a Volume of Fluid (VOF) closure for the surf tracking. The basis for the numerical approach...... is the surface tracking method in the open-source CFD toolbox OpenFoam\\textregistered{}, which is released by OpenCFD\\textregistered{}. This basic version has been extended with the ability for modelling surface water waves and sediment transport in the surf zone. The validation of these functionalities...... as part of this work. The numerical model is applied onto several physical settings. Firstly, the morphological response is turned off, and the hydrodynamics and the sediment transport patterns in the surf zone are described. The description considers these processes as a function of several non...

  5. COMPARATIVE EFFICIENCY OF SOME INDIRECT DIAGNOSTIC TESTS FOR THE DETECTION OF SUB-CLINICAL MASTITIS IN COWS AND BUFFALOES

    Directory of Open Access Journals (Sweden)

    M. IQBAL, M. AMJED1, M. A. KHAN, M. S. QURESHI1 AND U. SADIQUE1

    2006-04-01

    Full Text Available The present study was undertaken to compare five laboratory diagnostic tests for sub-clinical mastitis in cattle and buffaloes and to compute cost, time taken by each test and its ranking for availability, adoptability, interpretability and sensitivity. There were 352 cases with each test type viz. California Mastitis Test (CMT, White Side Test (WST, White Side + Dye (WSTD, Surf Test and Surf + Dye, and 880 cases with each species type (cattle and buffaloes. Result scores (1760 for sub-clinical mastitis in each category of negative, trace, single positive, double positive and triple positive by species, and laboratory tests, were analyzed using nonparametric tests. Chi-square statistics showed that CMT was equally effective at both locations (farm vs. laboratory. Correlation further suggested that the association was highly significant. Moreover, cases in category of negative, trace and single positive strongly differed (P0.05. The study further suggested that CMT was the most sensitive test, followed by WST/WSTD and Surf/Surf + Dye. Although, the five tests showed slight discrepancy in the trace category reaction, a strong relationship of Surf Test to CMT, its low cost, easy availability and readily adoptable qualities should spur the relevant authorities to recommend the use of Surf test as a routine practice in dairy farming and add this test in the curriculum of diploma and degree programmes.

  6. The fish community of a moderately exposed beach on the southwestern Cape coast of South Africa and an assessment of this habitat as a nursery for juvenile fish

    Science.gov (United States)

    Bennett, B. A.

    1989-03-01

    The ichthyofauna of a moderately exposed surf-zone habitat on the southwestern Cape coast of South Africa was sampled by seine netting monthly for 13 months. Twenty species of fish, 40 306 individuals weighing a total of 211 kg were captured. The number of species and standing crop varied seasonally with higher values occurring during the summer (January-March). The average summer standing stock of 38·6 g m -2 was considerably higher than any previously recorded from a surf-zone habitat and the annual average (10·1 g m -2 was comparable with that in estuaries. Eighteen of the species sampled occurred almost exclusively as juveniles and only two as adults. Four species were present throughout the year, 11 of them seasonally and the remaining five sporadically. Small juveniles (20-35 mm) typically appeared in the surf-zone 2-4 months after they were spawned. These 0+ juveniles remained there for between three months and one year depending on species, before vacating the surf-zone for their adult habitats. A comparison of the abundance of juveniles in the surf-zone with other inshore marine habitats suggested that five species ( Amblyrhynchotes honckenii, Cheilodonichthys capensis, Diplodus sargus, Lithognathus mormyrus and Pomadasys olivaceum) may be entirely, and three species ( Lichia amia, Liza richardsoni and Rhabdosargus globiceps) largely, dependent on the surf-zone as a nursery area. It was concluded that the surf-zone of sandy beaches may be as important as estuaries as a nursery habitat for juvenile fish.

  7. Photochemical production of hydrogen peroxide in size-fractionated Southern California coastal waters.

    Science.gov (United States)

    Clark, Catherine D; De Bruyn, Warren J; Jones, Joshua G

    2009-06-01

    Hydrogen peroxide (H(2)O(2)) photochemical production was measured in bulk and size-fractionated surf zone and source waters (Orange County, California, USA). Post-irradiation (60 min; 300 W ozone-free xenon lamp), maximum H(2)O(2) concentrations were approximately 10000 nM (source) and approximately 1500 nM (surf zone). Average initial hydrogen peroxide production rates (HPPR) were higher in bulk source waters (11+/-7.0 nM s(-1)) than the surf zone (2.5+/-1 nM s(-1)). A linear relationship was observed between non-purgeable dissolved organic carbon and absorbance coefficient (m(-1) (300 nm)). HPPR increased with increasing absorbance coefficient for bulk and size-fractionated source waters, consistent with photochemical production from CDOM. However, HPPR varied significantly (5x) for surf zone samples with the same absorbance coefficients, even though optical properties suggested CDOM from salt marsh source waters dominates the surf zone. To compare samples with varying CDOM levels, apparent quantum yields (Phi) for H(2)O(2) photochemical production were calculated. Source waters showed no significant difference in Phi between bulk, large (>1000 Da (>1 kDa)) and small (production efficiency is homogeneously distributed across CDOM size. However, surf zone waters had significantly higher Phi than source (bulk 0.086+/-0.04 vs. 0.034+/-0.013; 1 kDa 0.151+/-0.090 vs. 0.016+/-0.009), suggesting additional production from non-CDOM sources. H(2)O(2) photochemical production was significant for intertidal beach sand and senescent kelp (sunlight; approximately 42 nM h(-1) vs. approximately 5 nM h(-1)), on the order of CDOM production rates previously measured in coastal and oceanic waters. This is the first study of H(2)O(2) photochemical production in size-fractionated coastal waters showing significant production from non-CDOM sources in the surf zone.

  8. Efficient use of Fe metal as an electron transfer agent in a heterogeneous Fenton system based on Fe0/Fe3O4 composites.

    Science.gov (United States)

    Moura, Flávia C C; Araujo, Maria Helena; Costa, Regina C C; Fabris, José D; Ardisson, José D; Macedo, Waldemar A A; Lago, Rochel M

    2005-08-01

    In this work a novel heterogeneous Fenton system based on Fe(0)/Fe3O4 composites is described. The composites with several Fe(0)/Fe3O4 ratios were prepared by two different methods, i.e. mechanical alloying of Fe(0) and Fe3O4 powders and controlled reduction of Fe3O4 with H2. Reaction studies and detailed Conversion Electron Mössbauer surface characterization of the composites Fe(0)/Fe3O4, Fe(0), Fe3O4, alpha-Fe2O3 and gamma-Fe2O3 suggested that Fe2+surf species are essential to produce an active Fenton system. Kinetic studies for the oxidation of the dye methylene blue, used as an organic model molecule, and for the peroxide decomposition suggest that the reactions proceed via HO* radicals generated from Fe2+surf species and H2O2 in a Fenton like mechanism. The increase in activity caused by the addition of Fe(0) is discussed in terms of a creation of Fe2+surf species during the preparation of the composite and by an electron transfer mechanism from Fe(0) to Fe3+surf during the Fenton reaction to regenerate the Fe2+surf active species.

  9. AN EFFICIENT CONTENT AND SEGMENTATION BASED VIDEO COPY DETECTION

    Directory of Open Access Journals (Sweden)

    N. Kalaiselvi

    2015-10-01

    Full Text Available The field of multimedia technology has become easier to store, creation and access large amount of video data. This technology has editing and duplication of video data that will cause to violation of digital rights. So in this project we implemented an efficient content and segmentation based video copy detection concept to detect the illegal manipulation of video. In this Work or proposed system, Instead of SIFT matching algorithms, used combination of SIFT and SURF matching algorithms to detect the matching features in images. Because, SIFT is slow and not good at illumination changes, while it is invariant to rotation, scale changes and affine transformations and then SURF is fast and has good performance, but it is also have some issues that it is not stable to rotation and affine transformations. So combined the above two algorithms SIFT and SURF to extract the image features. Auto dual Threshold method is used to segment the video into segments and extract key frames from each segment and it also eliminate the redundant frame. SIFT and SURF features based on SVD is used to compare the two frames features sets points, where the SIFT and SURF features are extracted from the key frames of the segments. Graph-based video sequence matching method is used to match the sequence of query video and train video. It skillfully converts the video sequence matching result to a matching result graph.

  10. Space Debris Surfaces (Computer Code): Probability of No Penetration Versus Impact Velocity and Obliquity

    Science.gov (United States)

    Elfer, N.; Meibaum, R.; Olsen, G.

    1995-01-01

    A unique collection of computer codes, Space Debris Surfaces (SD_SURF), have been developed to assist in the design and analysis of space debris protection systems. SD_SURF calculates and summarizes a vehicle's vulnerability to space debris as a function of impact velocity and obliquity. An SD_SURF analysis will show which velocities and obliquities are the most probable to cause a penetration. This determination can help the analyst select a shield design that is best suited to the predominant penetration mechanism. The analysis also suggests the most suitable parameters for development or verification testing. The SD_SURF programs offer the option of either FORTRAN programs or Microsoft-EXCEL spreadsheets and macros. The FORTRAN programs work with BUMPERII. The EXCEL spreadsheets and macros can be used independently or with selected output from the SD_SURF FORTRAN programs. Examples will be presented of the interaction between space vehicle geometry, the space debris environment, and the penetration and critical damage ballistic limit surfaces of the shield under consideration.

  11. Trophic niche shifts driven by phytoplankton in sandy beach ecosystems

    Science.gov (United States)

    Bergamino, Leandro; Martínez, Ana; Han, Eunah; Lercari, Diego; Defeo, Omar

    2016-10-01

    Stable isotopes (δ13C and δ15N) together with chlorophyll a and densities of surf diatoms were used to analyze changes in trophic niches of species in two sandy beaches of Uruguay with contrasting morphodynamics (i.e. dissipative vs. reflective). Consumers and food sources were collected over four seasons, including sediment organic matter (SOM), suspended particulate organic matter (POM) and the surf zone diatom Asterionellopsis guyunusae. Circular statistics and a Bayesian isotope mixing model were used to quantify food web differences between beaches. Consumers changed their trophic niche between beaches in the same direction of the food web space towards higher reliance on surf diatoms in the dissipative beach. Mixing models indicated that A. guyunusae was the primary nutrition source for suspension feeders in the dissipative beach, explaining their change in dietary niche compared to the reflective beach where the proportional contribution of surf diatoms was low. The high C/N ratios in A. guyunusae indicated its high nutritional value and N content, and may help to explain the high assimilation by suspension feeders at the dissipative beach. Furthermore, density of A. guyunusae was higher in the dissipative than in the reflective beach, and cell density was positively correlated with chlorophyll a only in the dissipative beach. Therefore, surf diatoms are important drivers in the dynamics of sandy beach food webs, determining the trophic niche space and productivity. Our study provides valuable insights on shifting foraging behavior by beach fauna in response to changes in resource availability.

  12. Soliton assisted control of source to drain electron transport along natural channels - crystallographic axes - in two-dimensional triangular crystal lattices

    Science.gov (United States)

    Chetverikov, A. P.; Ebeling, W.; Velarde, M. G.

    2016-09-01

    We present computational evidence of the possibility of fast, supersonic or subsonic, nearly loss-free ballistic-like transport of electrons bound to lattice solitons (a form of electron surfing on acoustic waves) along crystallographic axes in two-dimensional anharmonic crystal lattices. First we study the structural changes a soliton creates in the lattice and the time lapse of recovery of the lattice. Then we study the behavior of one electron in the polarization field of one and two solitons with crossing pathways with suitably monitored delay. We show how an electron surfing on a lattice soliton may switch to surf on the second soliton and hence changing accordingly the direction of its path. Finally we discuss the possibility to control the way an excess electron proceeds from a source at a border of the lattice to a selected drain at another border by following appropriate straight pathways on crystallographic axes.

  13. Automated classification of histopathology images of prostate cancer using a Bag-of-Words approach

    Science.gov (United States)

    Sanghavi, Foram M.; Agaian, Sos S.

    2016-05-01

    The goals of this paper are (1) test the Computer Aided Classification of the prostate cancer histopathology images based on the Bag-of-Words (BoW) approach (2) evaluate the performance of the classification grade 3 and 4 of the proposed method using the results of the approach proposed by the authors Khurd et al. in [9] and (3) classify the different grades of cancer namely, grade 0, 3, 4, and 5 using the proposed approach. The system performance is assessed using 132 prostate cancer histopathology of different grades. The system performance of the SURF features are also analyzed by comparing the results with SIFT features using different cluster sizes. The results show 90.15% accuracy in detection of prostate cancer images using SURF features with 75 clusters for k-mean clustering. The results showed higher sensitivity for SURF based BoW classification compared to SIFT based BoW.

  14. Influence on surfers wind conditions east of the new Hanstholm harbour/wind turbine project

    DEFF Research Database (Denmark)

    Larsen, Torben J.; Astrup, Poul

    In this report a consequence study regarding the surfers wind conditions east of the planned new harbour area of Hanstholm. At this harbour area, 10 new 150m tall 3MW wind turbines are planned. Both the harbour constructions as well as the wind turbines could potentially alter the wind conditions...... as low turbulent conditions within the surf area. In general the impact of wind turbine wake is very limited in the eastern part of the surf area, whereas a reduction in mean wind speed in combination with increased turbulence intensity is seen in the western area....... on the lee side, which is an important area for wind and kite surfers. In this study, both changes in mean wind velocities as well as the turbulence level are investigated for the surf area between a location called ”Fish Factory” to the location called ”Hamburg”. The interesting wind speed interval is 8-16m...

  15. Modeling dune response using measured and equilibrium bathymetric profiles

    Science.gov (United States)

    Fauver, Laura A.; Thompson, David M.; Sallenger, Asbury H.

    2007-01-01

    Coastal engineers typically use numerical models such as SBEACH to predict coastal change due to extreme storms. SBEACH model inputs include pre-storm profiles, wave heights and periods, and water levels. This study focuses on the sensitivity of SBEACH to the details of pre-storm bathymetry. The SBEACH model is tested with two initial conditions for bathymetry, including (1) measured bathymetry from lidar, and (2) calculated equilibrium profiles. Results show that longshore variability in the predicted erosion signal is greater over measured bathymetric profiles, due to longshore variations in initial surf zone bathymetry. Additionally, patterns in predicted erosion can be partially explained by the configuration of the inner surf zone from the shoreline to the trough, with surf zone slope accounting for 67% of the variability in predicted erosion volumes.

  16. Goosebumps?

    Science.gov (United States)

    Friebele, Elaine

    Before surfing the waves at the beach this summer, surf the World Wide Web to learn how warm or cold the ocean water might be. Without sticking a toe in, you'll know whether its ice water or bath water from temperatures placed on-line by NOAA's National Oceanographic Data Center in Silver Spring, Md. Water temperatures are available for beaches along the Atlantic Coast from Eastport, Maine, to Key West, Fla.; along the Gulf Coast from Key West to South Padre Island, Tex.; along the Pacific Coast from Seattle, Wash., to Scripps Pier, Calif. Data for Puerto Rico, Bermuda, and parts of Mexico are also given.

  17. Design and implementation of data mining tools

    CERN Document Server

    Thuraisingham, Bhavani; Awad, Mamoun

    2009-01-01

    DATA MINING TECHNIQUES AND APPLICATIONS IntroductionTrendsData Mining Techniques and ApplicationsData Mining for Cyber Security: Intrusion DetectionData Mining for Web: Web Page Surfing PredictionData Mining for Multimedia: Image ClassificationOrganization of This BookNext StepsData Mining TechniquesIntroductionOverview of Data Mining Tasks and TechniquesArtificial Neural NetworksSupport Vector MachinesMarkov ModelAssociation Rule Mining (ARM)Multiclass ProblemImage MiningSummaryData Mining ApplicationsIntroductionIntrusion DetectionWeb Page Surfing PredictionImage ClassificationSummaryDATA MI

  18. International Disability Educational Alliance (IDEAnet)

    Science.gov (United States)

    2009-03-01

    uberman of HP Labs has been working to identify a num ber of “l aws of web surfing ” including the number of times an average user will go from website...Economist states that Dr. Bernardo H uberman of HP Labs has been working to identify a num ber of “law s of web surfing ” in cluding the num ber of...and the USAID Office of Health, Population and Nutrition . To expand the CIR’s current technology transfer efforts, Mr. Casanova introduced t hose he

  19. Unmixing Space Object’s Moderate Resolution Spectra

    Science.gov (United States)

    2013-09-01

    Earth Orbit or for small- sized ones. Spectral unmixing is a non-resolved technique that derives an object’s material composition from one or a series...for small-sized ones. Spectral unmixing is a non-resolved technique that derives an object?s material composition from one or a series of spectra...Aluminized,1 Mil,Kapton side out material 16 0.86 SURF 0072 Aluminum Alloy, 7075 -T6,Alodined material 18 1.08 SURF 0075

  20. The MAJORANA Project: a status report

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Steven Ray [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-09

    This series of slides presents the topic under the following aspects: ββ sensitivity, underground laboratory, shield, monoliths, strings, detectors, electroformed small parts, and background. Assembly and construction are proceeding at Sanford Davis Campus laboratory. Based on assays, material backgrounds are projected to meet cleanliness goals. Module 1 is complete. Electroformed copper has just been completed at SURF and PNNL. The shield is nearly complete. Successful reduction and refinement of enrGe has taken place with 98% yield. AMTEK (ORTEC) has produced 27 kg within 32 detectors from the reduced/refined enrGe; 30 of these are underground at SURF being assembled into strings.