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Sample records for hide side-by-side beneath

  1. Wake flow behind two side-by-side square cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Yen, Shun C., E-mail: scyen@mail.ntou.edu.t [Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, Keelung 202, Taiwan (China); Liu, Jung H. [Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, Keelung 202, Taiwan (China)

    2011-02-15

    This study investigates the flow structures, form drag coefficients and vortex-shedding characteristics behind a single-square cylinder and two side-by-side cylinders in an open-loop wind tunnel. The Reynolds number (Re) and gap ratio (g*) are 2262 < Re < 28,000 and 0 {<=} g* {<=} 12, respectively. The flow patterns around the square cylinders are determined using the smoke-wire scheme. Experimental results indicate that the flow structures behind two side-by-side square cylinders are classified into three modes -single mode, gap-flow mode and couple vortex-shedding. The gap-flow mode displays anti-phase vortex shedding induced from the interference between the two square cylinders. However, the couple vortex-shedding mode exhibits in-phase vortex shedding that is caused by the independent flow behavior behind each square cylinder. The surface-pressure profile, form drag coefficient for each square cylinder (C{sub D}-bar) and vortex-shedding frequency were measured and calculated using a pressure transducer and a hot-wire anemometer. For two side-by-side cylinder configurations, the maximum C{sub D}-bar of 2.24 occurs in the single mode, while the minimum C{sub D}-bar of 1.68 occurs in the gap-flow mode. Additionally, the C{sub D}-bar in the coupled vortex-shedding mode is intermediate and approximately equal to that of a single (isolated) square cylinder. Moreover, the single mode has the highest Strouhal number (St) and the gap-flow mode has the lowest St.

  2. Flapping propulsion with side-by-side pitching foils

    Science.gov (United States)

    Huera-Huarte, Francisco

    2016-11-01

    Fish schools are one of the most common types of collective behaviour observed in nature. One of the reasons why fish swim in groups, is to reduce the cost of transport of the school. In this work we explore the propulsive performance of two foils flapping in a symmetric configuration, i.e. with an out-of-phase flapping motion. Direct thrust measurements and Particle Image Velocimetry (PIV) allowed a detailed examination of the forces and the wake generated by the system, for different kinematics (swept angles and frequencies) and shaft separations. For certain specific cases, volumetric PIV shows major differences on how the different structures in the wake of the system evolve, depending on the imposed kinematics and the side-by-side separation between the foils. Results obtained will be compared against data produced with isolated flapping foils with similar imposed kinematics, with the aim to better understand the interactions between both and the performance of the system as a whole. The author would like to acknowledge the financial support provided by the Spanish Ministerio de Economia y competitividad (MINECO) through Grant DPI2015-71645-P.

  3. Experimental study on the near wake behind two side-by-side cylinders of unequal diameters

    Science.gov (United States)

    Gao, Yangyang; Yu, Dingyong; Tan, Soonkeat; Wang, Xikun; Hao, Zhiyong

    2010-10-01

    The wake structure behind two side-by-side circular cylinders with unequal diameter was investigated using the particle image velocimetry (PIV) technique. This investigation focused on the asymmetrical flow within the subcritical Reynolds number regime. A comparison between the time-averaged mean flow field of one cylinder and that of two side-by-side cylinders of unequal diameter was made for elucidating the mean flow characteristics attributable to the latter. The distribution of mean velocity behind two side-by-side unequal cylinders was distinctly different from that behind one cylinder, and an asymmetric combination was observed behind the two cylinders. The present paper also presents the authors' interpretation of the generation mechanism of gap flow deflection based on the instantaneous vorticity contours and velocity distribution. The effect of Reynolds number on flow structure was studied by analyzing the mean velocity distribution and time-averaged wake structures. The results showed that vortex formation length decreases with Reynolds number.

  4. Thickness control and interface quality as functions of slurry formulation and casting speed in side-by-side tape casting

    DEFF Research Database (Denmark)

    Bulatova, Regina; Jabbari, Mirmasoud; Kaiser, Andreas;

    2014-01-01

    A novel method of co-casting called side-by-side tape casting was developed aiming to form thin functionally graded films with varying properties within a single plane. The standard organic-based recipe was optimized to co-cast slurries into thick graded tapes. Performed numerical simulations...... identified the stable flow beneath the blade with a shear rate profile independent of slurry viscosity as long as the slurry load in the casting tank was low. Thickness and interface shape could be well predicted if the rheological behaviour of slurries is known and the processing parameters are well......-controlled. A well-defined steep interface was obtained by co-casting slurries with similar viscosities above 4000mPas at a speed of 40cm/min. The elastic properties of green tapes were proven to be defined by the binder concentration in the recipe formulation. The interfaces in graded tapes were shown to withstand...

  5. Water Quality Performance of Three Side-by-Side Permeable Pavement Surface Materials: Three Year Update

    Science.gov (United States)

    Communities are increasingly installing structural low impact development (LID) practices to mange stormwater and reduce pollutant loads associated with stormwater runoff. Permeable pavement is a LID practice that has limited research on working-scale, side-by-side performance o...

  6. Functionally Graded Ceramics Fabricated with Side-by-Side Tape Casting for Use in Magnetic Refrigeration

    DEFF Research Database (Denmark)

    Bulatova, Regina; Bahl, Christian; Andersen, Kjeld Bøhm

    2015-01-01

    Functionally graded ceramic tapes have been fabricated by a side-by-side tape casting technique. This study shows the possibility and describes the main principles of adjacent coflow of slurries resulting in formation of thin plates of graded ceramic material. Results showed that the small...

  7. Classification of gap flow regimes in two side-by-side circular cylinders

    CSIR Research Space (South Africa)

    Atkins

    2014-02-01

    Full Text Available The behavior of the flow around two circular cylinders arranged in a side-by-side configuration strongly depends on the transverse center-to-center gap spacing ratio (T/D) where D is the cylinder diameter. Based on the observed wake structure [13...

  8. Illinois Early Childhood Program Standards Matrix. (A Side-by-Side Comparison).

    Science.gov (United States)

    Illinois State Dept. of Human Services, East St. Louis. Head Start State Collaboration Office.

    This document contains a matrix offering a side-by-side comparison of almost 40 criteria among 7 sets of early childhood program standards. The standards are: (1) Head Start Program Performance Standards; (2) Illinois Department of Children and Family Services Child Care Licensing Standards; (3) Illinois Department of Human Services (IDHS) Center…

  9. Safety Assessment for a Side-by-side Offloading Mooring System

    Institute of Scientific and Technical Information of China (English)

    Liping Sun; Qiang He; Shangmao Ai

    2011-01-01

    In order to improve the safety properties of an offloading system with side-by-side (SBS) mooring in which the FPSO is moored by a yoke system in the field of BZ25-1,it is necessary to analyze those properties.According to the experience of similar projects,tow strategies of different offloading arrangements were discussed by using the 3-D radiation/diffraction theory and quasi-static time domain method to assess their respective safety properties.Through the safety assessment analysis of different arrangement comparisons,various ways to improve the safety properties of offloading systems with side-by-side mooring were verified by analyzing the tension in the mooring lines and the fender deflection.Through comparison it can be concluded that by enlarging the key factors properly,including the size of the fenders and the hawsers as well as the number of hawsers,a better satiety performance can be achieved.

  10. Aerodynamic drag from two tubes in side-by-side arrangement for different tube shapes

    Directory of Open Access Journals (Sweden)

    Олександр Михайлович Терех

    2016-06-01

    Full Text Available Experimental investigations of aerodynamic drag from two tubes in side-by-side arrangement for different tube shapes in the range of Reynolds numbers from 4000 to16000 are performed. Comparison of experimental data is executed. It is set, that the tubes of drop-shaped form have less aerodynamic drag and the tubes of flat-oval and dumb-bell forms have greater drag as compared to drag of circular tubes

  11. Experimental study on the near wake behind two side-by-side cylinders of unequal diameters

    Energy Technology Data Exchange (ETDEWEB)

    Gao Yangyang; Yu Dingyong [College of Engineering, Ocean University of China, Qingdao 266100 (China); Tan, Soonkeat [School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Wang Xikun [Maritime Research Center, Nanyang Technological University, Singapore 639798 (Singapore); Hao Zhiyong, E-mail: gaoyangyangouc@163.co [Shanghai Maritime University, Shanghai 200135 (China)

    2010-10-15

    The wake structure behind two side-by-side circular cylinders with unequal diameter was investigated using the particle image velocimetry (PIV) technique. This investigation focused on the asymmetrical flow within the subcritical Reynolds number regime. A comparison between the time-averaged mean flow field of one cylinder and that of two side-by-side cylinders of unequal diameter was made for elucidating the mean flow characteristics attributable to the latter. The distribution of mean velocity behind two side-by-side unequal cylinders was distinctly different from that behind one cylinder, and an asymmetric combination was observed behind the two cylinders. The present paper also presents the authors' interpretation of the generation mechanism of gap flow deflection based on the instantaneous vorticity contours and velocity distribution. The effect of Reynolds number on flow structure was studied by analyzing the mean velocity distribution and time-averaged wake structures. The results showed that vortex formation length decreases with Reynolds number.

  12. Analysis of wave resonant effects in-between offshore vessels arranged side-by-side

    OpenAIRE

    Dinoi, Pasquale

    2016-01-01

    La predicción de la interacción hidrodinámica entre dos cuerpos flotantes en la configuración side-by-side (lado-a-lado) se ha convertido en un importante y complicado problema en los últimos años. Esta situación es relevante cuando se trata de tomar decisiones sobre la viabilidad de una serie de operaciones offshore, principalmente relacionadas con el proceso de transferencia de carga líquida entre dos cascos. Esta tesis se profundiza en algunos aspectos hidrodinámico relevantes que surgen c...

  13. The Variation of Interface Formation with Slurry Viscosity Change in Side-By-Side Tape Casting

    DEFF Research Database (Denmark)

    Bulatova, Regina; Jabbari, Masoud; Andersen, Kjeld Bøhm;

    Homogenous and flexible adjacently graded tapes were produced by casting the organic-based slurries simultaneously. To develop side-by-side tape casing (SBSTC), the material optimization, modernization of the doctor blade design, and parameters control of such processes as casting, drying, de......-bindering and sintering were studied. Solvent and binder concentrations were varied in order to optimize co-casting flow, as well as the drying and sintering shrinkage. Tapes were evaluated in terms of rheological behavior of the slurries, the green and sintered tape microstructure, the quality of the interface area...

  14. NUMERICAL SIMULATION OF FLOW OVER TWO SIDE-BY-SIDE CIRCULAR CYLINDERS

    Institute of Scientific and Technical Information of China (English)

    SARVGHAD-MOGHADDAM Hesam; NOOREDIN Navid; GHADIRI-DEHKORDI Behzad

    2011-01-01

    In the present paper,the unsteady,viscous,incompressible and 2-D flow around two side-by-side circular cylinders was simulated using a Cartesian-staggered grid finite volume based method.A great-source term technique was employed to identify the solid bodies (cylinders) located in the flow field and boundary conditions were enforced by applying the ghost-cell technique.Finally,the characteristics of the flow around two side-by-side cylinders were comprehensively obtained through several computational simulations.The computational simulations were performed for different transverse gap ratios (1.5≤T/D≤4) in laminar (Re =100,200 ) and turbulent (Re =104) regimes,where T and D are the distance between the centers of cylinders and the diameter of cylinders,respectively.The Reynolds number is based on the diameter of cylinders,D.The pressure field and vorticity distributions along with the associated streamlines and the time histories of hydrodynamic forces were also calculated and analyzed for different gap ratios.Generally,different flow patterns were observed as the gap ratio and Reynolds number varied.Accordingly,the hydrodynamic forces showed irregular variations for small gaps while they took a regular pattern at higher spacing ratios.

  15. HYDRODYNAMIC INTERACTION BETWEEN FLNG VESSEL AND LNG CARRIER IN SIDE BY SIDE CONFIGURATION

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wen-hua; YANG Jian-min; HU Zhi-qiang

    2012-01-01

    The Floating Liquefied Natural Gas (FLNG) is a new type of floating platform for the exploitation of stranded offshore oil/gas fields.The side by side configuration for the FLNG vessel and the LNG carrier arranged in parallel is one of the possible choices for the LNG offloading.During the offioading operations,the multiple floating bodies would have very complex responses due to their hydrodynamic interactions.In this study,numerical simulations of multiple floating bodies in close proximity in the side by side offioading configuration are carried out with the time domain coupled analysis code SIMO.Hydrodynamic interactions between the floating bodies and the mechanical coupling effects between the floating bodies and their connection systems are included in the coupled analysis model.To clarify the hydrodynamic effects of the two vessels,numerical simulations under the same environmental condition are also conducted without considering the hydrodynamic interactions,for comparison.It is shown that the hydrodynamic interactions play an important role in the low frequency motion responses of the two vessels,but have little effect on the wave frequency motion responses.In addition,the comparison results also show that the hydrodynamic interactions can affect the loads on the connection systems.

  16. LARGE EDDY SIMULATION AND SPECTRUM ANALYSIS OF FLOW AROUND TWO SQUARE CYLINDERS ARRANGED SIDE BY SIDE

    Institute of Scientific and Technical Information of China (English)

    魏英杰; 朱蒙生; 何钟怡

    2004-01-01

    Large eddy simulation cooperated with the second order full extension ETG (Euler-Taylor-Galerkin) finite element method was applied to simulate the flow around two square cylinders arranged side by side at a spacing ratio of 1.5. The second order full extension ETG finite element method was developed by Wang and He. By means of Taylor expansion of terms containing time derivative, time derivative is replaced by space derivative. The function of it is equal to introducing an artificial viscosity term. The streamlines of the flow at different moments were obtained. The time history of drag coefficient, lift coefficient and the streamwise velocity on the symmetrical points were presented. Furthermore, the symmetrical problem of the frequency spectrum of flow around two square cylinders arranged side by side were studied by using the spectral analysis technology. The data obtained at the initial stage are excluded in order to avoid the influence of initial condition on the results. The power spectrums of drag coefficient, lift coefficient, the streamwise velocity on the symmetrical points were analyzed respectively.The results show that although the time domain process of dynamic parameters is nonsymmetrical, the frequency domain process of them is symmetrical under the symmetrical boundary conditions.

  17. Interaction of Gap Flow With Flapping Dynamics of Two Side-by-Side Elastic Foils

    Science.gov (United States)

    Gurugubelli, Pardha S.; Jaiman, Rajeev K.

    2016-11-01

    We present a numerical analysis on the interaction between two side-by-side elastic foils with their leading edges clamped and the gap flow between them. We perform systematic parametric direct numerical simulations as a function of nondimensional bending rigidity, KB ∈ [ 1 ×10-4 , 3 ×10-3 ] and mass-ratio, m* ∈ [ 0 . 05 , 0 . 2 ] , for a fixed gap, dp = 0 . 2 / L , at the leading edge and Reynolds number, Re = 1000 to explain the underlying physical mechanism behind the in-phase and out-of-phase coupled flapping modes. The parametric simulations show that the parallel foil system exhibits predominant out-of-phase coupling for low mass-ratio m* 0 . 1 . We also show that the two side-by-side elastic foils always exhibit out-of-phase coupling initially irrespective of whether the fully developed flapping show out-of-phase or in-phase coupled mode. Finally, we show that the transition from the initial out-of-phase to stable in-phase is characterized by loss of gap flow symmetric stability to undergo oscillations at the gap exit.

  18. Three--dimensional Instability in the Wake of Two Side--by--side Square Cylinders

    Science.gov (United States)

    Choi, Choon-Bum; Jang, Yong-Jun; Yang, Kyung-Soo

    2011-11-01

    Three-dimensional instability in the flow past two square cylinders in side-by-side arrangements has been numerically studied via a Floquet stability analysis. The distance between the neighboring faces of the two cylinders (G) is the key parameter which affects the secondary instability under consideration. In this talk, we present the critical Reynolds number for the 3D instability and the spanwise wave number corresponding to the most unstable (or least stable) wave for each G. When the two cylinders are close to each other, the Floquet mode resembles mode A of flow past a single cylinder. For large G, the Floquet mode for each cylinder is independent of the neighboring cylinder as expected. In the range of intermediate G, interference of the two wakes is clearly reflected in the Floquet mode. We also discuss about the effect of gap flow, and visualization of the dominant 3D vortical structures is provided by using Q contours. Our results shed light on a complete understanding of the onset of 3D instability in the presence of two side-by-side square cylinders. This work was supported by Korea Railroad Research Institute (Research Title: The study of standardization for urban railway facilities (SW 11002)).

  19. Quantitative flow characteristics for side-by-side square cylinders via PIV

    Directory of Open Access Journals (Sweden)

    Dogan Sercan

    2012-04-01

    Full Text Available In this study, instantaneous and time-averaged flow structures downstream of the sharp-edged single and two and three side-by-side square cylinders (SCs immersed in a uniform open channel water flow were studied by a technique of particle image velocimetry (PIV. Experimental results of wake flow structures were presented for gap ratios (G/D in the range of 1.0”G/D”3.0 for Reynolds number values of 1050, 2450 and 3400. Flow structures depending on the square cylinder (SC configurations and Reynolds number were discussed. It has been found that the development of the vortex shedding as well as the flow structure were substantially altered for side-by-side SCs comparing to the single SC. Asymmetrical and biased wake structures were observed because of the jetlike flow between the SCs for two SCs cases for the gap ratio less than 2.0. Depending on the gap spacing between the SCs, the interaction results of time2 averaged vorticity, velocity vector field, Reynolds stress correlations and streamline patterns in the wake region form a distinguished flow structure. Strouhal numbers for the single square cylinder for 1050≤Re≤3400 are found in the range of 0.12-0.13. The present results have supported the previous works by providing detailed quantitative experimental information with PIV in the wake region of the SC and might be helpful for validation of numerical studies and designers.

  20. Side by side tests of two SDHW systems with solar collectors with and without antireflection treatment

    DEFF Research Database (Denmark)

    Kong, Weiqiang; Han, Jiangong; Perers, Bengt

    2015-01-01

    Two low flow SDHW systems based on mantle tanks are tested side by side in a laboratory test facility for solar heating systems under the same weather and operation conditions. The systems are identical with the exception that one system is equipped with a solar collector with antireflection...... treated glass while the other system has a collector with a normal glass. Measurements of the thermal performance of the two systems have been carried out for a long measuring period. The thermal performances of the systems have also been calculated with a detailed simulation model. There is a good...... agreement between measured and calculated thermal performances for both systems. The extra thermal performance of the system with the solar collector with the anti reflection treated glass cover is a strong function of the solar fraction. In sunny periods with high solar fractions the percentage extra...

  1. Wave Drift Forces on Two Floating Bodies Arranged Side by Side

    Institute of Scientific and Technical Information of China (English)

    Wenyang Duan; Binbin Zhao

    2011-01-01

    An innovative hydrodynamic theory and numerical model were developed to help improve the efficiency,accuracy,and convergence of the numerical prediction of wave drift forces on two side-by-side deepwater floating bodies.The wave drift forces were expressed by the double integration of source strength and the corresponding Green function on the body surface,which is consistent with the far field formula based on momentum conservation and sharing the advantage of near field calculations providing the drift force on each body.Numerical results were validated through comparing the general far field model and pressure integral model,as well as the middle field model developed using the software HydroStar.

  2. Flow Features of Three Side-by-side Circular Cylinders at Low Reynolds Number

    Directory of Open Access Journals (Sweden)

    Liu Junkao

    2016-01-01

    Full Text Available In order to study the fluctuation of kinetic parameter of cylinder matrix in incompressible stationary flow, the flow fluid around three side-by-side circular cylinders are simulated using Immersed Boundary–Lattice Boltzmann method (IB-LBM. Drag and lift force of the three cylinders are investigated as the interval between each cylinder varied from zero to five times of the cylinder diameter. Five flow patterns are defined according to the vortices structure in the downstream of the cylinders. Power spectrum analysis of lift force is developed to explain the vortex patterns. Through the research, we find the strength and phase of the gap flow play an important role in the vortex formatting process. The vortices shedding from different cylinders neutralize and combine in the near wake, contributing a lot to the variation of forces.

  3. Measured Data Processing Method For Relative Motions Between Two Side-by-side Ships

    Directory of Open Access Journals (Sweden)

    Ping-an Shi

    2013-01-01

    Full Text Available In order to design and implement a wave compensation system to reduce the relative motion between two side-by-side ships in waves, a new method to process measured data of ship model test with contact measurement to study the characteristics of relative motion was presented. The reference co-ordinate systems and relative motions were defined, and the scheme of the model test was described. Then the Empirical Mode Decomposition(EMD adaptive filter were designed, the frequency domain integration transform method based upon Fast Fourier Transform(FFT were established. The procedure to transform acceleration signal into displacement was proposed and verified, and the processing results with and without EMD adaptive filter were compared. Finally, the relative motions consistent with reality were acquired, which indicates this method is effective for measured data processing.

  4. SIDE-BY-SIDE TESTS OF DIFFERENTLY DESIGNED EVACUATED TUBULAR COLLECTORS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Dragsted, Janne; Furbo, Simon

    2007-01-01

    Six differently designed evacuated tubular collectors, ETCs, utilizing solar radiation from all directions, have been investigated experimentally. The evacuated tubular solar collectors investigated include one SLL all-glass ETC from Tshinghua Solar Co., four heat pipe ETCs from Sunda Technolgoy Co....... and one all-glass ETC with heat pipe from Exoheat AB. The collectors have been investigated side-by-side in an outdoor test facility for a long period. During the measurements, the operating conditions – such as weather conditions, inlet and mean solar collector fluid temperatures have been the same. Thus...... a direct performance comparison is possible. The results of the measurements will be presented in this paper. Among other things, the influence on the thermal performance of the absorber design will be explained. Further, it will be illustrated how the thermal performances of the different collector types...

  5. Interface Oscillation in the Side-by-Side (SBS) Tape Casting of Functionally Graded Ceramics (FGCs)

    DEFF Research Database (Denmark)

    Jabbari, Masoud; Bulatova, Regina; Hattel, Jesper Henri

    2012-01-01

    is a common process in producing multilayer ceramics, which now is used for producing side-by-side (SBS) functionally graded ceramics (FGCs). These FGCs are mostly used in the magnetic refrigeration sectors due to the varying composition of the magnetocaloric materials so that the magnetic transition...... temperature of the magnetic regenerator varies along the paths. The main goal of this research is to study the multiple material flow in SBS tape casting and analyze its influence on the interface between the stripes. The materials used for the experimental part are La0.85Sr0.15MnO3 and Ce0.9Gd0.1O2ceramic...... slurries. The rheological behavior of the slurries are extracted from experiments and used in the ANSYS FLUENT commercial code to develop a fluid flow model for the non-Newtonian ceramic slurries and evaluate the interface oscillation between the stripes in SBS tape casting. The Numerical results show...

  6. Wake structures of two side by side spheres in a tripped boundary layer flow

    Directory of Open Access Journals (Sweden)

    Canli Eyüb

    2014-03-01

    Full Text Available Two independent spheres were placed in a side by side arrangement and flow structure in the wake region of the spheres was investigated with a Particle Image Velocimetry (PIV system when the spheres were in a boundary layer over a flat plate as a special case. Reynolds number was 5000 based on the sphere diameter which was 42.5 mm. Boundary layer was tripped 8mm away from the leading edge of the flat plate with a 5 mm trip wire. The thickness of the hydrodynamically developed boundary layer was determined as 63mm which was larger than the sphere diameter of D=42.5mm. Wake region of the spheres was examined from point of flow physics for the different sphere locations in the ranges of 0≤G/D ≤1.5 and 0≤S/D ≤1.5 where G and S were the distance between the spheres and the distance between the bottom point of the spheres and the flat plate surface, respectively. Depending on the different sphere locations, instantaneous and time averaged vorticity data, scalar values of time-averaged velocity components and their root mean square (rms values and time averaged vorticity data are presented in the study for the evaluation of wake region of the spheres. It is demonstrated that the gap between the two spheres and the interaction between the gap and the boundary layer greatly affects flow pattern, especially when spheres are located near to the flat plate surface, i.e. S/D=0.1 for 0≤G/D ≤1.5. Different distances between the spheres resulted in various flow patterns as the spheres were approached to the flat plate. The distance S/D=0.1 for all gap values has the strongest effect on the wake structures. Beyond G/D=1.0, the sphere wakes tend to be similar to single sphere case. The instantaneous vorticity fields of the side by side arrangements comprised wavy structures in higher level comparing to an individual sphere case. The gap flow intensifies the occurrence of small scale eddies in the wake region. The submersion rate of the spheres

  7. Wake structures of two side by side spheres in a tripped boundary layer flow

    Science.gov (United States)

    Canli, Eyüb; Özgören, Muammer; Dogan, Sercan; Hilmi Aksoy, Muharrem; Akilli, Huseyin

    2014-03-01

    Two independent spheres were placed in a side by side arrangement and flow structure in the wake region of the spheres was investigated with a Particle Image Velocimetry (PIV) system when the spheres were in a boundary layer over a flat plate as a special case. Reynolds number was 5000 based on the sphere diameter which was 42.5 mm. Boundary layer was tripped 8mm away from the leading edge of the flat plate with a 5 mm trip wire. The thickness of the hydrodynamically developed boundary layer was determined as 63mm which was larger than the sphere diameter of D=42.5mm. Wake region of the spheres was examined from point of flow physics for the different sphere locations in the ranges of 0≤G/D ≤1.5 and 0≤S/D ≤1.5 where G and S were the distance between the spheres and the distance between the bottom point of the spheres and the flat plate surface, respectively. Depending on the different sphere locations, instantaneous and time averaged vorticity data, scalar values of time-averaged velocity components and their root mean square (rms) values and time averaged vorticity data are presented in the study for the evaluation of wake region of the spheres. It is demonstrated that the gap between the two spheres and the interaction between the gap and the boundary layer greatly affects flow pattern, especially when spheres are located near to the flat plate surface, i.e. S/D=0.1 for 0≤G/D ≤1.5. Different distances between the spheres resulted in various flow patterns as the spheres were approached to the flat plate. The distance S/D=0.1 for all gap values has the strongest effect on the wake structures. Beyond G/D=1.0, the sphere wakes tend to be similar to single sphere case. The instantaneous vorticity fields of the side by side arrangements comprised wavy structures in higher level comparing to an individual sphere case. The gap flow intensifies the occurrence of small scale eddies in the wake region. The submersion rate of the spheres actually determines the

  8. Microfluidic conceived drug loaded Janus particles in side-by-side capillaries device.

    Science.gov (United States)

    Khan, Ikram Ullah; Serra, Christophe A; Anton, Nicolas; Li, Xiang; Akasov, Roman; Messaddeq, Nadia; Kraus, Isabelle; Vandamme, Thierry F

    2014-10-01

    A side-by-side capillaries microfluidic device was developed to fabricate drug loaded poly(acrylamide)/poly(methyl acrylate) Janus particles in the range of 59-240 μm by UV-assisted free radical polymerization. This system was characterized in terms of continuous and dispersed phases flow rates (Qc/Qd), monomer composition of the two compartments, surfactant nature and concentration, outlet tube diameter and UV intensity. These factors were adequately controlled to get different particle shapes ranging from core-shell to bi-compartmental particles. For the latter, a low surfactant concentration (0.75 wt.%) was necessary when the two dispersed phases were pumped at equal flow rate, while at high surfactant concentration, dispersed phases flow rates have to be changed. FTIR analysis suggested complete polymerization of monomers and cytotoxicity test showed these particles were biocompatible having LD 50 of 9 mg/mL. Both ketoprofen and sodium fluorescein were released in sustained release manner at pH 6.8 by following a diffusion type release mechanism. Drug release was faster for bigger particles and found to result from the irregular distribution of the two phases and indentation on bigger particles as revealed by SEM analysis. In comparison, sodium fluorescein release was slower which was attributed to low encapsulation but could be modified by decreasing crosslinker concentration.

  9. Propulsive performance of unsteady tandem hydrofoils in a side-by-side configuration

    Science.gov (United States)

    Dewey, Peter A.; Quinn, Daniel B.; Boschitsch, Birgitt M.; Smits, Alexander J.

    2014-04-01

    Experimental and analytical results are presented on two identical bio-inspired hydrofoils oscillating in a side-by-side configuration. The time-averaged thrust production and power input to the fluid are found to depend on both the oscillation phase differential and the transverse spacing between the foils. For in-phase oscillations, the foils exhibit an enhanced propulsive efficiency at the cost of a reduction in thrust. For out-of-phase oscillations, the foils exhibit enhanced thrust with no observable change in the propulsive efficiency. For oscillations at intermediate phase differentials, one of the foils experiences a thrust and efficiency enhancement while the other experiences a reduction in thrust and efficiency. Flow visualizations reveal how the wake interactions lead to the variations in propulsive performance. Vortices shed into the wake from the tandem foils form vortex pairs rather than vortex streets. For in-phase oscillation, the vortex pairs induce a momentum jet that angles towards the centerplane between the foils, while out-of-phase oscillations produce vortex pairs that angle away from the centerplane between the foils.

  10. Numerical Study on Interaction Between Two Bubbles Rising Side by Side in CMC Solution

    Institute of Scientific and Technical Information of China (English)

    FAN Wenyuan; YIN Xiaohong

    2013-01-01

    A numerical simulation was performed to investigate the interaction of two bubbles rising side by side in shear-thinning fluid using volume of fluid (VOF) method coupled with continuous surface force (CSF) method.By considering rheological characteristics of fluid,this approach was able to accurately capture the deformation of bubble interface,and validated by comparing with the experimental results.The rising of bubble pairs with different configurations,including horizontal alignment and oblique alignment,was simulated by the method.The influences of the bubble initial distance and the bubble alignment were studied by analyzing the bubble deformation,rising paths and flow fields surrounding bubbles.The results indicate that within certain initial bubble spacing of S* =3.3(S* =SI/D,SI initial distance between bubbles,and D bubble diameter),the dynamic interaction between two bubbles aligned horizontally shows repulsive effect that decreases with the increase of initial bubble spacing,but weakens to certain degree by the shear-thinning properties of fluid.However,the interaction between two bubbles aligned obliquely presents a repulsive effect for the small angle involved but an attractive impact for the large one,which is yet strengthened by the rheological characteristics of fluid.

  11. Medicated Janus fibers fabricated using a Teflon-coated side-by-side spinneret.

    Science.gov (United States)

    Yu, Deng-Guang; Yang, Chen; Jin, Miao; Williams, Gareth R; Zou, Hua; Wang, Xia; Bligh, S W Annie

    2016-02-01

    A family of medicated Janus fibers that provides highly tunable biphasic drug release was fabricated using a side-by-side electrospinning process employing a Teflon-coated parallel spinneret. The coated spinneret facilitated the formation of a Janus Taylor cone and in turn high quality integrated Janus structures, which could not be reliably obtained without the Teflon coating. The fibers prepared had one side consisting of polyvinylpyrrolidone (PVP) K60 and ketoprofen, and the other of ethyl cellulose (EC) and ketoprofen. To modulate and tune drug release, PVP K10 was doped into the EC side in some cases. The fibers were linear and had flat morphologies with an indent in the center. They provide biphasic drug release, with the PVP K60 side dissolving very rapidly to deliver a loading dose of the active ingredient, and the EC side resulting in sustained release of the remaining ketoprofen. The addition of PVP K10 to the EC side was able to accelerate the second stage of release; variation in the dopant amount permitted the release rate and extent this phase to be precisely tuned. These results offer the potential to rationally design systems with highly controllable drug release profiles, which can complement natural biological rhythms and deliver maximum therapeutic effects.

  12. Modality-specific communication enabling gait synchronization during over-ground side-by-side walking.

    Science.gov (United States)

    Zivotofsky, Ari Z; Gruendlinger, Leor; Hausdorff, Jeffrey M

    2012-10-01

    An attentive observer will notice that unintentional synchronization of gait between two walkers on the street seems to occur frequently. Nonetheless, the rate of occurrence and motor-sensory mechanisms underlying this phase-locking of gait have only recently begun to be investigated. Previous studies have either been qualitative or carried out under non-natural conditions, e.g., treadmill walking. The present study quantitatively examined the potential sensory mechanisms that contribute to the gait synchronization that occurs when two people walk side by side along a straight, over-ground, pathway. Fourteen pairs of subjects walked 70 m under five conditions that manipulated the available sensory feedback. The modalities studied were visual, auditory, and tactile. Movement was quantified using a trunk-mounted tri-axial accelerometer. A gait synchronization index (GSI) was calculated to quantify the phase synchronization of the gait rhythms. Overall, 36% of the walks exhibited synchrony. Tactile and auditory feedback showed the greatest ability to synchronize, while visual feedback was the least effective. The results show that gait synchronization during natural walking is common, quantifiable, and has modality-specific properties.

  13. Side-by-side ANFIS as a useful tool for estimating correlated thermophysical properties

    Science.gov (United States)

    Grieu, Stéphane; Faugeroux, Olivier; Traoré, Adama; Claudet, Bernard; Bodnar, Jean-Luc

    2015-12-01

    In the present paper, an artificial intelligence-based approach dealing with the estimation of correlated thermophysical properties is designed and evaluated. This new and "intelligent" approach makes use of photothermal responses obtained when homogeneous materials are subjected to a light flux. Commonly, gradient-based algorithms are used as parameter estimation techniques. Unfortunately, such algorithms show instabilities leading to non-convergence in case of correlated properties to be estimated from a rebuilt impulse response. So, the main objective of the present work was to simultaneously estimate both the thermal diffusivity and conductivity of homogeneous materials, from front-face or rear-face photothermal responses to pseudo random binary signals. To this end, we used side-by-side neuro-fuzzy systems (adaptive network-based fuzzy inference systems) trained with a hybrid algorithm. We focused on the impact on generalization of both the examples used during training and the fuzzification process. In addition, computation time was a key point to consider. That is why the developed algorithm is computationally tractable and allows both the thermal diffusivity and conductivity of homogeneous materials to be simultaneously estimated with very good accuracy (the generalization error ranges between 4.6% and 6.2%).

  14. FLOW PAST TWO ROTATING CIRCULAR CYLINDERS IN A SIDE-BY-SIDE ARRANGEMENT

    Institute of Scientific and Technical Information of China (English)

    GUO Xiao-hui; LIN Jian-zhong; TU Cheng-xu; WANG Hao-li

    2009-01-01

    Measurements were performed using Particle Image Velocimetry (PIV) to analyze the modification of flow by the combined effects of the rotation and the Reynolds number on the flow past two rotating circular cylinders in a side-by-side-arrangement at a range of , (α is the rotational speed) at one gap spacing of (T and d are the distance between the centers of two cylinders and the cylinder diameter, respectively). A new Immersed-Lattice Boltzmann Method (ILBM) scheme was used to study the effect of the gap spacing on the flow. The results show that the vortex shedding is suppressed as rotational speed increases. The flow reaches a steady state when the vortex shedding for both cylinders is completely suppressed at critical rotational speed. As the rotational speed further increases, the separation phenomenon in the boundary layers disappears at the attachment rotational speed. The critical rotational speed and attachment rotational speed become small as Reynolds number increases. The absolute rotational speed of cylinders should be large at same critical rotational speed and attachment rotational speed in the case of large Reynolds number. The gap spacing has an important role in changing the pattern of vortex shedding. It is very different in the mechanism of vortex shedding suppression for the flows around two rotating cylinders and single rotating cylinder.

  15. Interface Oscillation in the Side-by-Side (SBS) Tape Casting of Functionally Graded Ceramics (FGCs)

    Science.gov (United States)

    Jabbari, Masoud; Bulatova, Regina; Hattel, Jesper; Bahl, Christian

    2012-11-01

    Room temperature magnetic refrigeration is a new highly efficient and environmentally protective technology. Although it has not been maturely developed, it shows great applicable prosperity and seems to be a potential substitute for the traditional vapor compression technology. Tape Casting is a common process in producing multilayer ceramics, which now is used for producing side-by-side (SBS) functionally graded ceramics (FGCs). These FGCs are mostly used in the magnetic refrigeration sectors due to the varying composition of the magnetocaloric materials so that the magnetic transition temperature of the magnetic regenerator varies along the paths. The main goal of this research is to study the multiple material flow in SBS tape casting and analyze its influence on the interface between the stripes. The materials used for the experimental part are La0 . 85 Sr0 . 15 MnO3 and Ce0 . 9 Gd0 . 1O2 ceramic slurries. The rheological behavior of the slurries are extracted from experiments and used in the ANSYS FLUENT commercial code to develop a fluid flow model for the non-Newtonian ceramic slurries and evaluate the interface oscillation between the stripes in SBS tape casting. The Numerical results show reasonable agreement with corresponding experimental results.

  16. Study of fluid resonance between two side-by-side floating barges

    Institute of Scientific and Technical Information of China (English)

    李欣; 徐亮瑜; 杨建民

    2016-01-01

    The hydrodynamic interaction between two vessels in a side-by-side configuration attracted research attentions in recent years. However, because the conventional potential flow theory does not consider the fluid viscosity, in the hydrodynamic results, the wave elevations were overestimated in the narrow gap under resonance conditions. To overcome this limitation and investigate the complex fluid flow around multiple bodies in detail, this study examines the fluid resonance between two identical floating barges using a viscous flow analysis program FLOW-3D. The volume of fluid method is implemented for tracking the free surface, and a porous media model is used near the outflow boundary to enhance the wave absorption. A three-dimensional numerical wave basin is established and validated by comparison with the waves generated using theoretical values. On this basis, a computational fluid dynamics (CFD) simulation of the two barges in a resonance wave period is performed, and the wave elevations, the fluid flow around the barges, and the motions of the barges are discussed. The numerical simulation is verified by comparison with results of corresponding experimental data.

  17. Side-by-Side Testing of Water Heating Systems: Results from the 2013–2014 Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Colon, Carlos [Florida Solar Energy Center, Cocoa, FL (United States)

    2017-07-01

    The Florida Solar Energy Center (FSEC) completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). The evaluation studied the performance of five hot water systems (HWS) plus a reference baseline system for each fuel, (i.e., electric and natural gas). Electric HWS consisted of two residential electric heat pump water heaters (HPWHs, 60 and 80 gallons), a solar thermal system using a polymer absorber (glazed) collector with 80-gallon storage and a duplicate 50-gallon standard electric water heater with added cap and wrap insulation. Baseline performance data were collected from a standard 50-gallon electric water heater of minimum code efficiency to compare energy savings. Similarly, a standard 40-gallon upright vented natural gas water heater served as baseline for the natural gas fuel category. The latter, having a larger jacket diameter [18 in., with an energy factor (EF) of 0.62] with increased insulation, replaced a former baseline (17 in. diameter, EF = 0.59) that served during three previous testing rotations (2009–2013). A high-efficiency, condensing natural gas hybrid water heater with 27-gallon buffered tank was also tested and compared against the gas baseline. All systems underwent testing simultaneously side-by-side under the criteria specified elsewhere in this report.

  18. Intrinsic features of flow around two side-by-side square cylinders

    Science.gov (United States)

    Alam, Md. Mahbub; Zhou, Y.

    2013-08-01

    The wake of two side-by-side square cylinders is investigated in detail based on flow visualization at a Reynolds number (Re) of 300. The cylinder center-to-center spacing ratio T* (= T/W, W is the cylinder width) is varied from 1.0 to 5.0. The intrinsic features of the wake are explored, including the gap vortices, flow switch, stability, merging of two streets into one, etc. The qualitative information on these features is further complemented by the quantitative information extracted from hotwire data at Re = 4.7 × 104 using both spectral and cross-wavelet analyses. Four flow regimes are identified: (i) the single bluff body regime (T* 2.4). The gap flow is found to switch at two distinct time scales, referred to as macro and micro switches. Macro switch occurs at 1.2 gap flow is slim in width and biased for a long duration ranging from several vortex shedding periods in the wide street to several hours. Micro switch is observed at 2.1 gap flow is thick in width and switches at a frequency of twice the frequency of vortex shedding from the free-stream side of the cylinders. The two streets formed immediately behind the cylinders merge to a single street at a downstream location x_c^* that depends on T*. A larger T* corresponds to a larger x_c^*. Regime (iv) is characterized by two streets either inphased or antiphased. The antiphased streets persist longer than the inphased.

  19. Criticality of flow transition behind two side-by-side elliptic cylinders

    Science.gov (United States)

    Peng, Y. F.; Sau, Amalendu; Hwang, Robert R.; Yang, W. C.; Hsieh, Chih-Min

    2012-03-01

    In this study, near-critical bifurcations of low Reynolds number (Re) flows past a pair of elliptic cylinders in the side-by-side arrangement are numerically investigated, and onsets of several distinct transition scenarios are addressed. A nested Cartesian-grid formulation, in combination with an effective immersed boundary method and a two-step fractional-step procedure, has been adopted to simulate the flows. The transition scenarios associated with various periodic, quasi-periodic, and biased flows, their bifurcation characteristics, corresponding critical Reynolds numbers, and phase-portraits are exploited to better understand the governing physics. From the global point of view, there appear variety of flow patterns within the investigated parameter space, 40 ⩽ Re ⩽ 300, 0.2 ⩽ G ⩽ 3.0 (G being the gap-ratio of the cylinders), and 1.5 ⩽ A ⩽ 3 (A is the cylinder aspect-ratio), which include, symmetric vortex shedding mode, semi-single/twin vortex street formations, asymmetric/deflected flows, stationary/biased flip-flopped-type vortex shedding, weakly-chaotic flows, and in-phase/anti-phase vortex synchronizations. We numerically present these flows by tuning Re quasi-stationary, and provide a broader understanding of the entire transition process. A comprehensive analysis of effects of Reynolds number, the gap-ratio, and the angle of incidence on different flow-induced forces on the cylinders is included in this regard. On the other hand, our simulated wakes with various non-zero incidence-angles are found to reveal a rich variety of instability induced weakly synchronized physical evolution characteristics, which remained virtually unexplored.

  20. Interaction dynamics of gap flow with vortex-induced vibration in side-by-side cylinder arrangement

    Science.gov (United States)

    Liu, Bin; Jaiman, Rajeev K.

    2016-12-01

    A numerical investigation of the vortex-induced vibration (VIV) in a side-by-side circular cylinder arrangement has been performed in a two-dimensional laminar flow environment. One of the cylinders is elastically mounted and only vibrates in the transverse direction, while its counterpart remains stationary in a uniform flow stream. When the gap ratio is sufficiently small, the flip-flopping phenomenon of the gap flow can be an additional time-dependent interference to the flow field. This phenomenon was reported in the experimental work of Bearman and Wadcock ["The interaction between a pair of circular cylinders normal to a stream," J. Fluid Mech. 61(3), 499-511 (1973)] in a side-by-side circular cylinder arrangement, in which the gap flow deflects toward one of the cylinders and switched its sides intermittently. Albeit one of the two cylinders is free to vibrate, the flip-flop of a gap flow during VIV dynamics can still be observed outside the lock-in region. The exact moments of the flip-flop phenomenon due to spontaneous symmetry breaking are observed in this numerical study. The significant characteristic vortex modes in the near-wake region are extracted via dynamic modal analysis and the interference between the gap flow and VIV is found to be mutual. In a vibrating side-by-side arrangement, the lock-in region with respect to reduced velocity becomes narrower due to the interference from its stationary counterpart. The frequency lock-in occurs and ends earlier than that of an isolated vibrating circular cylinder subjected to an identical flow environment. Similar to a tandem cylinder arrangement, in the post-lock-in region, the maximum vibration amplitudes are escalated compared with those of an isolated circular cylinder configuration. On the other hand, subjected to the influence from VIV, the biased gap flow deflects toward the vibrating cylinder quasi-stably during the frequency lock-in process. This behavior is different from the reported bi

  1. Coupling Motion and Energy Harvesting of Two Side-by-Side Flexible Plates in a 3D Uniform Flow

    Directory of Open Access Journals (Sweden)

    Dibo Dong

    2016-05-01

    Full Text Available The fluid-structure interaction problems of two side-by-side flexible plates with a finite aspect ratio in a three-dimensional (3D uniform flow are numerically studied. The plates’ motions are entirely passive under the force of surrounding fluid. By changing the aspect ratio and transverse distance, the coupling motions, drag force and energy capture performance are analyzed. The mechanisms underlying the plates’ motion and flow characteristics are discussed systematically. The adopted algorithm is verified and validated by the simulation of flow past a square flexible plate. The results show that the plate’s passive flapping behavior contains transverse and spanwise deformation, and the flapping amplitude is proportional to the aspect ratio. In the side-by-side configuration, three distinct coupling modes of the plates’ motion are identified, including single-plate mode, symmetrical flapping mode and decoupled mode. The plate with a lower aspect ratio may suffer less drag force and capture less bending energy than in the isolated situation. The optimized selection for obtaining higher energy conversion efficiency is the plate flapping in single-plate mode, especially the plate with a higher aspect ratio. The findings of this work provide several new physical insights into the understanding of fish schooling and are expected to inspire the developments of underwater robots or energy harvesters.

  2. Influence of the side-by-side arrangement on the performance of a small Savonius wind turbine

    Directory of Open Access Journals (Sweden)

    Jang Choon-Man

    2016-01-01

    Full Text Available Scaled-down Savonius turbine rotors arrayed side-by-side are introduced to analyze the effects of design parameters on the performance between turbine rotors. Unsteady flow simulation and experimental measurement have been performed to compare turbine performance and validate the numerical simulation of the turbine rotor. Commercial code, SC/Tetra, which uses an unstructured grid system, has been used to solve the three-dimensional unsteady Reynolds-averaged Navier–Stokes equations. Single turbine rotors and two turbine rotors arrayed side-by-side were numerically analyzed. The distance between rotor tips is 0.5 times the rotor diameter. Throughout the numerical simulation, the power coefficient obtained by the time-averaged result of unsteady flow simulation was found to be in good agreement with the experimental result. A discussion on the design parameters using both a single and arrayed turbine rotors is presented based on the results of the unsteady flow simulation, including the flow field, power coefficient, velocity and vorticity contours.

  3. Time-Domain Simulation for Coupled Motions of Three Barges Moored Side-by-Side in Floatover Operation

    Institute of Scientific and Technical Information of China (English)

    许鑫; 杨建民; 李欣; 徐亮瑜

    2015-01-01

    Simulating the coupled motions of multiple bodies in the time domain is a complex problem because of the strong hydrodynamic interactions and coupled effect of various mechanical connectors. In this study, we investigate the hydrodynamic responses of three barges moored side-by-side in a floatover operation in the frequency and time domains. In the frequency domain, the damping lid method is adopted to improve the overestimated hydrodynamic coefficients calculated from conventional potential flow theory. A time-domain computing program based on potential flow theory and impulse theory is compiled for analyses that consider multibody hydrodynamic interactions and mechanical effects from lines and fenders. Correspondingly, an experiment is carried out for comparison with the numerical results. All statistics, time series, and power density spectra from decay and irregular wave tests are in a fairly good agreement.

  4. WAKE PATTERNS OF FLOW PAST A PAIR OF CIRCULAR CYLINDERS IN SIDE-BY-SIDE ARRANGEMENTS AT LOW REYNOLDS NUMBERS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A flow past two side-by-side identical circular cylinders was numerically investigated with the unstructured spectral element method. From the computational results at various non-dimensional distances between cylinder centers T/D and the Reynolds number Re, a total of nine kinds of wake patterns were observed: four steady wake patterns, including single bluff-body steady pattern, separated double-body steady pattern and transition steady pattern for sub-critical Reynolds numbers and biased steady pattern for super-critical Reynolds numbers, and five unsteady wake patterns, including single bluff-body periodic pattern, biased quasi-steady pattern, quasi-periodic (flip-flopping) pattern, in-phase-synchronized pattern and anti-phase-synchronized pattern. Time evolution of lift and drag coefficients corresponding to each unsteady wake pattern was given.

  5. Numerical simulation of fluid flow of two rotating side-by-side circular cylinders by Lattice Boltzmann method

    Science.gov (United States)

    Nemati, Hasan; Sedighi, Kurosh; Farhadi, Mousa; Pirouz, Mohammad Mohammadi; Fattahi, Ehsan

    2010-03-01

    A numerical investigation of the two-dimensional laminar flow around side-by-side rotating circular cylinders using Lattice Boltzmann method is conducted. The effects of variation of rotational speed ratio β and different gap spacings g* at Reynolds number of 100 are studied. A various range of rotational speed ratio 0 ≤ β ≤ 2 for four different gap spacings of 3, 1.5, 0.7 and 0.2 are investigated. Flow conditions and its characteristics, such as lift and drag coefficients and Strouhal number, is studied. The results indicated that as β increases, the flow changes its condition from periodic to steady after a critical rotational speed. Results also indicated that variation of the gap spacing and rotational speed has significant effect on wake pattern. Wake pattern in turn has significant effect on the Strouhal number. Finally, the result is compared with experimental and other numerical data.

  6. Properties of the flow around two rotating circular cylinders in side-by-side arrangement with different rotation types

    Directory of Open Access Journals (Sweden)

    Tu Cheng-Xu

    2014-01-01

    Full Text Available The field characteristics of two side-by-side rotating circular cylinders in a cross-flow is investigated under different rotation types, at T/D = 1.11,1.6, and 3, respectively (T is the center spacing between the cylinders, and D is the cylinder diameter. A similar flow pattern which is the most efficient to narrow the lowpressure area is identified for rotation type A, independent of T/D ratio, and two typical flow patterns are found under different spacings for rotation type B and type C, respectively. It is confirmed that there is an optimal rotational speed of 1.7-2, under rotation type A to attenuate the vortices, velocity drop, and turbulence intensity tremendously. As rotational speed increases to the optimal value, both the velocity drop and turbulence intensity decrease and their distributions are smooth. The results indicate that the shear layers which are accelerated following the free-stream direction would have significant influence on the flow modification, and different rotation types actually arrange these shear layers in diverse ways to change the flow pattern. Pitch ratio is capable to transform the gap flow, which is usually including the shear layers referred, thus this parameter can modify the wake of the two cylinders at different rotation types.

  7. Unsteady Performance of Finite-Span Pitching Propulsors in Mixtures of Side-by-Side and In-Line Arrangements

    Science.gov (United States)

    Kurt, Melike; Moored, Keith

    2016-11-01

    Birds, insects, and fish propel themselves by flapping their wings or oscillating their fins in unsteady motions. Many of these animals fly or swim in groups or collectives, typically described as flocks, swarms and schools. The three-dimensional steady flow interactions and the two dimensional unsteady flow interactions that occur in collectives are well characterized. However, the interactions that occur among three-dimensional unsteady propulsors remain relatively unexplored. The aim of the current study is to measure the forces acting on and the energetics of two finite-span pitching wings. The wings are arranged in mixtures of canonical in-line and side-by-side configurations while the phase delay between the pitching wings is varied. The thrust force, fluid-mediated interaction force between the wings and the propulsive efficiency are quantified. The three-dimensional interaction mechanisms are compared and contrasted with previously examined two-dimensional mechanisms. Stereoscopic particle image velocimetry is employed to characterize the three-dimensional flow structures along the span of the pitching wings.

  8. Dynamic interference of two anti-phase flapping foils in side-by-side arrangement in an incompressible flow

    Science.gov (United States)

    Bao, Y.; Zhou, D.; Tao, J. J.; Peng, Z.; Zhu, H. B.; Sun, Z. L.; Tong, H. L.

    2017-03-01

    A two-dimensional computational hydrodynamic model is developed to investigate the propulsive performance of a flapping foil system in viscous incompressible flows, which consists of two anti-phase flapping foils in side-by-side arrangement. In the simulations, the gap between the two foils is varied from 1.0 to 4.0 times of the diameter of the semi-circular leading edge; the amplitude-based Strouhal number is changed from 0.06 to 0.55. The simulations therefore cover the flow regimes from negligible to strong interference in the wake flow. The generations of drag and thrust are investigated as well. The numerical results reveal that the counter-phase flapping motion significantly changes the hydrodynamic force generation and associated propulsive wake. Furthermore, the wake interference becomes important for the case with a smaller foil-foil gap and induces the inverted Bénard von Kármán vortex streets. The results show that the hydrodynamic performance of two anti-phase flapping foils can be significantly different from an isolated pitching foil. Findings of this study are expected to provide new insight for developing hydrodynamic propulsive systems by improving the performance based on the foil-foil interaction.

  9. Addressing reverse osmosis fouling within water reclamation--a side-by-side comparison of low-pressure membrane pretreatments.

    Science.gov (United States)

    Kent, Fraser C; Farahbakhsh, Khosrow

    2011-06-01

    A tertiary membrane filtration (TMF) pilot operating on secondary effluent and a membrane bioreactor (MBR) were setup in a side-by-side study as pretreatments for two identical reverse osmosis pilot systems. The water quality of the permeate from both low-pressure membrane pretreatment systems and the fouling rate of the reverse osmosis systems were compared to assess the capabilities of the two low-pressure membrane pretreatments to prevent organic fouling of the reverse osmosis systems. Both pretreatment pilots were setup using typical operating conditions (i.e., solids retention time and mixed-liquor suspended solids). A consistent difference in water quality and reverse osmosis performance was demonstrated during the 12-month study. The MBR permeate consistently had significantly lower total organic carbon (TOC) and chemical oxygen demand concentrations, but higher color and specific UV absorbance compared with the permeate from the TMF pretreatment. The pretreatment with the MBR gave an average reverse osmosis fouling rate over the entire study (0.27 Lmh/bar.month) that was less than half of the value found for the reverse osmosis with TMF pretreatment (0.60 Lmh/bar.month). A correlation of reverse osmosis feed TOC concentration with average reverse osmosis fouling rate also was established, independent of the pretreatment method used. Results from a cleaning analysis, energy dispersive spectroscopy, and fourier transformed infrared reflectometry confirmed that the foulants were primarily organic in nature. It is concluded that, for this type of application and setup, MBR systems present an advantage over tertiary membrane polishing of secondary effluent for reverse osmosis pretreatment.

  10. Mechanisms of sound amplification and sound reduction in the flapping flight of side-by-side airfoils

    Science.gov (United States)

    Manela, A.; Halachmi, M.

    2015-06-01

    The acoustic signature of side-by-side airfoils, subject to small-amplitude harmonic pitching and incoming flow unsteadiness, is investigated. The two-dimensional near-field problem is formulated using thin-airfoil theory, where flow unsteadiness is modeled as a passing line vortex, and wake evolution is calculated via the Brown and Michael formula. Assuming that the setup is acoustically compact, acoustic radiation is obtained by means of the Powell-Howe acoustic analogy. The associated compact Green's function is calculated numerically using potential-flow analysis of the fluid-structure flow domain. Results, comparing the acoustic radiation of the double-airfoil system to a reference case of a single airfoil, point to several mechanisms of sound attenuation and sound amplification, caused by airfoil-airfoil and airfoils-wake interactions. It is found that counter-phase pitching of the airfoils results in effective cloaking of the system, which otherwise becomes significantly noisy (as a 5/2-power of the pitching frequency) at large frequencies. In addition, depending on the distance between airfoils, in-phase pitching may result in an acoustic signature equivalent to a single airfoil (when the airfoils are adjacent) or to two separate airfoils (when the airfoils are far apart). In general, flow unsteadiness produces more sound when interacting with a double (compared with a single) airfoil setup. However, airfoils' nonlinear wake-wake interactions give rise to a sound reduction mechanism, which becomes most efficient at times when incoming vorticity passes above airfoils' leading and trailing edges. The present scheme can be readily extended to consider the acoustic properties of various double-airfoil configurations, as well as multiple (> 2) airfoil setups.

  11. Experimental studies of vertical mixing patterns in open channel flow generated by two delta wings side-by-side

    Science.gov (United States)

    Vaughan, Garrett

    Open channel raceway bioreactors are a low-cost system used to grow algae for biofuel production. Microalgae have many promises when it comes to renewable energy applications, but many economic hurdles must be overcome to achieve an economic fuel source that is competitive with petroleum-based fuels. One way to make algae more competitive is to improve vertical mixing in algae raceway bioreactors. Previous studies show that mixing may be increased by the addition of mechanisms such as airfoils. The circulation created helps move the algae from the bottom to top surface for necessary photosynthetic exchange. This improvement in light utilization allowed a certain study to achieve 2.2-2.4 times the amount of biomass relative to bioreactors without airfoils. This idea of increasing mixing in open channel raceways has been the focus of the Utah State University (USU) raceway hydraulics group. Computational Fluid Dynamics (CFD), Acoustic Doppler Velocimetry (ADV), and Particle Image Velocimetry (PIV) are all methods used at USU to computationally and experimentally quantify mixing in an open channel raceway. They have also been used to observe the effects of using delta wings (DW) in increasing vertical mixing in the raceway. These efforts showed great potential in the DW in increasing vertical mixing in the open channel bioreactor. However, this research begged the question, does the DW help increase algae growth? Three algae growth experiments comparing growth in a raceway with and without DW were completed. These experiments were successful, yielding an average 27.1% increase in the biomass. The DW appears to be a promising method of increasing algae biomass production. The next important step was to quantify vertical mixing and understand flow patterns due to two DWs side-by-side. Raceway channels are wider as they increase in size; and arrays of DWs will need to be installed to achieve quality mixing throughout the bioreactor. Quality mixing was attained for

  12. Lock-on characteristics behind two side-by-side cylinders of diameter ratio two at small gap ratio

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Petry Y.R.; Lu, Wei-Ting; Chou, Shy-Tsin; Kuo, Cheng-Hsiung [National Chung Hsing University, Department of Mechanical Engineering, Taichung (China)

    2012-10-15

    The lock-on characteristics, the detailed interactions and downstream evolutions of the wakes behind side-by-side cylinders of unequal diameter (D/d = 2), spaced by a gap ratio 0.75 (G/D = 0.75), are investigated at Reynolds number 600 by the dye flow visualization, laser Doppler anemometry (LDA) and particle image velocimeter (PIV) velocity measurements. The lock-on frequency bands are studied by LDA and PIV at Reynolds number 2,000. The D, d and G are the diameters of the large, the small cylinders and the net gap between two cylinders, respectively. Periodic excitations, in form of rotary oscillation about the cylinder center, are applied to the large cylinder with the same amplitude. It is found that while the large cylinder is excited, two lock-on frequency bands of the wake behind the large cylinder are detected. These two lock-on frequency bands correspond to the primary and the one-third sub-harmonic lock-on of the wake behind large cylinder, respectively. These two lock-on frequency bands distribute symmetrically about the fundamental and the third superharmonic of the natural shedding frequency behind a single cylinder at the same Reynolds number. The left-shifted frequency band (1.8 {<=} f{sub e} /f{sub os} {<=} 2.0) is not considered as a locked-on frequency band because the phase difference between two excitation frequencies across f{sub e} /f{sub os} = 2.0 vary significantly. While the wake behind the large cylinder is locked-on at f{sub e} /3 (or f{sub os}), the gap flow becomes unbiased and the frequency of the wake behind small cylinder remains around the natural shedding frequency. Thus, the frequency band of 3.0 {<=} f{sub e} /f{sub os} {<=} 3.22 is also not locked-on because the phase difference in the narrow wake excited at f{sub e} /f{sub os} = 2.93 and 3.07 changes significantly. Note f{sub e} and f{sub os} denote the excitation frequency and the natural shedding frequency behind a single large cylinder, respectively. (orig.)

  13. Lock-on characteristics behind two side-by-side cylinders of diameter ratio two at small gap ratio

    Science.gov (United States)

    Lee, Petry Y. R.; Lu, Wei-Ting; Chou, Shy-Tsin; Kuo, Cheng-Hsiung

    2012-10-01

    The lock-on characteristics, the detailed interactions and downstream evolutions of the wakes behind side-by-side cylinders of unequal diameter ( D/ d = 2), spaced by a gap ratio 0.75 ( G/ D = 0.75), are investigated at Reynolds number 600 by the dye flow visualization, laser Doppler anemometry (LDA) and particle image velocimeter (PIV) velocity measurements. The lock-on frequency bands are studied by LDA and PIV at Reynolds number 2,000. The D, d and G are the diameters of the large, the small cylinders and the net gap between two cylinders, respectively. Periodic excitations, in form of rotary oscillation about the cylinder center, are applied to the large cylinder with the same amplitude. It is found that while the large cylinder is excited, two lock-on frequency bands of the wake behind the large cylinder are detected. These two lock-on frequency bands correspond to the primary and the one-third sub-harmonic lock-on of the wake behind large cylinder, respectively. These two lock-on frequency bands distribute symmetrically about the fundamental and the third superharmonic of the natural shedding frequency behind a single cylinder at the same Reynolds number. The left-shifted frequency band (1.8 ≤ f e / f os ≤ 2.0) is not considered as a locked-on frequency band because the phase difference between two excitation frequencies across f e / f os = 2.0 vary significantly. While the wake behind the large cylinder is locked-on at f e /3 (or f os ), the gap flow becomes unbiased and the frequency of the wake behind small cylinder remains around the natural shedding frequency. Thus, the frequency band of 3.0 ≤ f e / f os ≤ 3.22 is also not locked-on because the phase difference in the narrow wake excited at f e / f os = 2.93 and 3.07 changes significantly. Note f e and f os denote the excitation frequency and the natural shedding frequency behind a single large cylinder, respectively.

  14. Side-by-side comparison of disposable microchips with commercial capillary cartridges for application in capillary isoelectric focusing with whole column imaging detection.

    Science.gov (United States)

    Liu, Zhen; Ou, Junjie; Samy, Razim; Glawdel, Tomasz; Huang, Tiemin; Ren, Carolyn L; Pawliszyn, Janusz

    2008-10-01

    Simple-structured, well-functioned disposable poly(dimethylsiloxane) (PDMS) microchips were developed for capillary isoelectric focusing with whole column imaging detection (CIEF-WCID). Side-by-side comparison of the developed microchips with well-established commercial capillary cartridges demonstrated that the disposable microchips have comparable performance as well as advantages such as absence of lens effect and possibility of high-aspect-ratio accompanied with a dramatic reduction in cost.

  15. Comparison and correction of the light sensor output from 48 wearable light exposure devices by using a side-by-side field calibration method

    DEFF Research Database (Denmark)

    Markvart, Jakob; Hansen, Åse Marie; Christoffersen, Jens

    2015-01-01

    . We tested 48 Actiwatch devices side by side under various light sources and present the red, green, blue, and white light response variability among the Actiwatches. The influence of different spatial and spectral light environments on the white light response when compared with the output from...... by the equipment variability. To compensate for inter-equipment variability we stress the need for a field calibration procedure. When light exposure devices of lower grade quality are used in spectrally and spatially changing light environments, daylight from a diffused overcast sky is suggested to be used...

  16. The side-by-side exploratory test: a simple automated protocol for the evaluation of adult zebrafish behavior simultaneously with social interaction.

    Science.gov (United States)

    Schaefer, Isabel C; Siebel, Anna M; Piato, Angelo L; Bonan, Carla D; Vianna, Mônica R; Lara, Diogo R

    2015-10-01

    The assessment of shoaling in adult zebrafish is technically difficult, but important, given their social nature. The present study aimed to characterize a new protocol using simple automated tracking software to evaluate general behavior and social interaction simultaneously. To this end, we used a single tank with a central transparent glass division and placed one zebrafish on each side for 5 min. This strategy allows fish to interact visually at the same time that individual automated evaluation of behavior can be easily performed. Our results showed that, when two fish are placed side-by-side, there is an increase in their height in the tank compared with isolated fish and they remain close to each other. The pharmacological treatments with benzodiazepines (bromazepam and clonazepam) and the serotonergic drugs buspirone, fluoxetine, and escitalopram did not affect locomotion at the concentrations tested, except for the highest concentration of buspirone. Nevertheless, benzodiazepines increased interfish distance (i.e. reduced shoaling behavior) and serotonergic drugs elevated height in the tank. These results support the use of the side-by-side exploratory test for behavioral studies with the zebrafish, including high-throughput behavioral screening for antidepressants and anxiolytics.

  17. Synchronized vortex shedding and sound radiation from two side-by-side rectangular cylinders of different cross-sectional aspect ratios

    Energy Technology Data Exchange (ETDEWEB)

    Octavianty, Ressa, E-mail: ressa-octavianty@ed.tmu.ac.jp; Asai, Masahito, E-mail: masai@tmu.ac.jp [Department of Aerospace Engineering, Tokyo Metropolitan University, 6-6 Asahigaoka, Hino, Tokyo 191-0065 (Japan)

    2015-10-15

    Synchronized vortex shedding from two side-by-side cylinders and the associated sound radiation were examined experimentally at Reynolds numbers of the order of 10{sup 4} in low-Mach-number flows. In addition to a pair of square cylinders, a pair of rectangular cylinders, one with a square cross section (d × d) and the other with a rectangular cross section (d × c) having a cross-sectional aspect ratio (c/d) of 1.2–1.5, was considered. The center-to-center distance between the two cylinders L/d was 3.6, 4.5, and 6.0; these settings were within the non-biased flow regime for side-by-side square cylinders. In case of a square cylinder pair, anti-phase synchronized vortex shedding occurring for L/d = 3.6 and 4.5 generated a quadrupole-like sound source which radiated in-phase, planar-symmetric sound in the far field. Synchronized vortex shedding from the two rectangular cylinders with different c/d also occurred with almost the same frequency as the characteristic frequency of the square-cylinder wake in the case of the small center-to-center distance, L/d = 3.6, for all the cylinder pairs examined. The synchronized sound field was anti-phase and asymmetric in amplitude, unlike the case of a square cylinder pair. For larger spacing L/d = 4.5, synchronized vortex shedding and anti-phase sound still occurred, but only for close cross-sectional aspect ratios (c/d = 1.0 and 1.2), and highly modulated sound was radiated with two different frequencies due to non-synchronized vortex shedding from the two cylinders for larger differences in c/d. It was also found that when synchronized vortex shedding occurred, near-wake velocity fluctuations exhibited high spanwise-coherency, with a very sharp spectral peak compared with the single-cylinder case.

  18. Numerical Simulation of the vortex shedding from two side-by-side square cylinders in gas-liquid two-phase flow

    Science.gov (United States)

    Zhou, Y. L.; Deng, D.

    2010-03-01

    Considering the turbulence deduced by shearing stress and air bubble, and based on two-fluid model, gas-liquid two-phase flow around two square cylinders in side-by-side arrangement in vertical tube with different void fraction different spacing ratio is numerically simulated by using the finite volume method in this paper. It is found that the gap flow with the spacing ratio smaller than 2.0 is not only biased to one side, resulting in the formation of a narrower wake behind one cylinder and a wider wake behind the other, but also not-biased to neither of them; vortex shedding from the two cylinders with the spacing ratio larger than or equal to 2.0 is synchronized. But when the spacing ratio is equal to 2.0, In-phase mode is the predominant mode while anti-phase mode predominates when the spacing ratio is 2.5, 3.0, 5.0. In bias pattern, the cylinder with wide wake has smaller resistance, the cylinder with narrow wake has larger resistance, and the cylinders with middle wake have equality resistance. Meanwhile the spacing ratio has tremendous influence on pulsating lift, amplitude spectrum and so on. The volume of void fraction in the incident flow influence the vortex production, falling off & development heavily. When the volume of void fraction increases to 0.12, the stable vortex street does not produce.

  19. Performance evaluation of the latest fully automated hematology analyzers in a large, commercial laboratory setting: a 4-way, side-by-side study.

    Science.gov (United States)

    Bourner, G; Dhaliwal, J; Sumner, J

    2005-01-01

    Gamma-Dynacare is a Canadian-based community laboratory partnership formed in the mid-1990s through the merger of 3 prominent Ontario medical diagnostic laboratories. Laboratory Corporation of America acquired an interest in the GD partnership in mid 2002. We service more than 10,000 community-based Canadian clinicians, hospital partners, and private clients with an integrated customer-focused system that includes specimen collection, transportation, and results reporting services. With more than 1,700 highly qualified medical, technical, and support staff and a network of laboratories, Gamma Dynacare aims to be at the forefront of technological innovation to better service the clinician base and ultimately deliver better patient care. We were looking for a hematology analyzer that would allow. (1) standardization throughout Ontario in our 4 largest sites and (2) better performance to effectively handle aged samples and minimize slide review. To select the best, most productive hematology analyzer for our environment, it was decided to perform a side-by-side comparison of the top hematology analyzers from Abbott (Cell-Dyn 3500), Beckman Coulter (LH 750), Bayer (Advia 120), and Sysmex (XE 2100), utilizing the same samples. CBC, differential and reticulocyte parameters were all evaluated according to CLSI (formerly NCCLS) and established hematology analyzer evaluation guidelines. We assessed each analyzer for precision, linearity, carryover, stability, differential capabilities, slide review rates, and throughput (clean bench studies). Two hundred samples were assessed for differential and morphology flagging on each analyzer using the reference 400 cell manual differential for comparison. Throughput was assessed by analyzing 700 consecutive samples representative of our workload mix. Stability studies at 24 hours showed that the Beckman Coulter LH 750 was least affected by EDTA, effect with minimal changes in the mean corpuscular volume (MCV) and hematocrit. Both

  20. 小间距的旁靠驳船间水动力干扰数值与试验研究%Numerical and Experimental Study on Hydrodynamic Interactions between Two Side-by-side Barges in Close Proximity

    Institute of Scientific and Technical Information of China (English)

    徐亮瑜; 杨建民; 李欣; 许鑫

    2014-01-01

    当海上多船联合作业时,船体之间会发生水动力干扰。当间距较小时,两船的水动力参数与间距内部波面升高在某些频率处存在强烈的共振现象,而基于理想流体的经典势流理论对此共振结果的模拟存在较大失真。为了弥补此项问题,文章采用加盖阻尼法(damping lid method)对3 m间距旁靠布置的两艘相同驳船的水动力干扰现象进行研究。通过在间距内部的自由液面边界条件上添加阻尼耗散项,使间距内部的过大波面升高被显著抑制,从而得到更接近实际的数值计算结果。在此基础上开展模型试验研究,通过对比模型试验与数值模拟结果发现,当无量纲阻尼参数ε取为0.026时,两船之间自由液面升高、两船的运动响应与平均漂移力计算结果均与试验结果吻合较好。%Aiming at the hydrodynamic interaction between two vessels in side by side configuration, the conventional potential theory based on the ideal fluid assumption overestimates the hydrodynam-ic results and wave elevations in the gap near the resonance region. This paper investigates the hy-drodynamic performances of two identical barges with close proximity in side by side configuration using the damping lid method. With this method, the wave exaggeration in the gap is suppressed ef-fectively and more realistic numerical results are obtained. Corresponding experiment are carried out to validate the numerical results and comparison between the test results and calculation shows good agreement. Wave elevations in the gap, motion responses and drift forces of the two barges can all achieve satisfactory agreement when the unique non-dimensional damping parameter ε is set to 0.026.

  1. 基于VOSET方法模拟并排气泡的上升过程%Simulation of a Pair of Bubbles Rising Side by Side Using VOSET Method

    Institute of Scientific and Technical Information of China (English)

    李隆键; 张磊; 朱文冰; 申宪文

    2015-01-01

    A numerical simulation was performed to investigate two bubbles rising side by side in vertical channel using VOSET ( Coupled Volume⁃of⁃Fluid and Level Set) method and N⁃S equations coupled with continuous surface force ( CSF) model. Behaviors of coalescence between two identical bubbles predicted were in good agreement with experimental results reported in literature. Effects of surface tension on trajectories and velocities during rising process are investigated. Three types of motion were observed depending on surface tension: Coalescence, two bubbles repeatedly attracted and bounced against each other, bounced and separated. Without coalescence, trajectory shows symmetry about channel center line. Vertical velocities of both bubbles are almost the same while magnitude of horizontal velocity with opposite direction equals.%采用VOSET方法和耦合表面张力模型的N⁃S方程,模拟竖直通道内并排气泡对的上升过程,模拟与实验结果吻合较好。重点研究表面张力系数对并排气泡上升轨迹和速度的影响。结果表明,随着表面张力系数的变化,并排气泡对的上升过程出现三种类型:两气泡融合,两气泡反复靠近、远离但未融合,两气泡碰撞反弹后逐渐远离。在未融合的情况下,并排气泡对的上升轨迹关于通道中心线对称,左右两个气泡的上升速度基本一致,水平速度大小相同,方向相反。

  2. Restless legs syndrome (Willis-Ekbom disease) and growing pains: are they the same thing? A side-by-side comparison of the diagnostic criteria for both and recommendations for future research.

    Science.gov (United States)

    Walters, Arthur S; Gabelia, David; Frauscher, Birgit

    2013-12-01

    There has been no previous side-by-side comparison of the diagnostic criteria for restless legs syndrome (RLS) (Willis-Ekbom disease) and growing pains. In our review, we explore this comparison emphasizing overlaps and disconnects, summarize recent literature exploring the relationship between the 2 entities, and make suggestions for future research. There is considerable overlap in the diagnostic criteria for childhood RLS and growing pains. The literature also indicates that RLS and growing pains more commonly occur together than one would expect based on chance alone, and the family histories of RLS and growing pains often are overlapping. Leg rubbing to obtain relief from leg discomfort is common to both disorders, though walking to obtain relief seems unique to RLS. Childhood RLS also has been reported to be painful in up to 45% of cases. The development of standard diagnostic criteria is necessary to move forward in the field of growing pains research. A quantitative and validated rating scale for growing pains severity already exists. Because of the clinical and genetic similarity between RLS and growing pains, studies that parallel those previously performed in RLS patients are recommended for growing pains patients. For example, a genome wide association study in growing pains patients of all possible genes with particular attention to those identified as related to RLS and a therapeutic trial of medications known to be effective in RLS would be welcome. Abnormalities in vitamin D metabolism also may be common to both disorders. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Reversible Data Hiding Techniques

    Directory of Open Access Journals (Sweden)

    Dhananjay Yadav

    2012-03-01

    Full Text Available Reversible data hiding is a technique that is used to hide data inside an image. The data is hidden in such a way that the exact or original data is not visible. The hidden data can be retrieved as and when required. There are several methods that are used in reversible data hiding techniques like Watermarking, Lossless embedding and encryption. In this paper we present a review of reversible watermarking techniques and show different methods that are used to get reversible data hiding technique with higher embedding capacity and invisible objects. Watermark need not be hidden. Watermarking can be applied to 1. Images, 2. Text, 3. Audio/video, 4. Software.

  4. Hiding Information under Speech

    Science.gov (United States)

    2005-12-12

    as it arrives in real time, and it disappears as fast as it arrives. Furthermore, our cognitive process for translating audio sounds to the meaning... steganography , whose goal is to make the embedded data completely undetectable. In addi- tion, we must dismiss the idea of hiding data by using any...therefore, an image has more room to hide data; and (2) speech steganography has not led to many money-making commercial businesses. For these two

  5. HIDE: HI Data Emulator

    Science.gov (United States)

    Akeret, Joel; Seehars, Sebastian; Chang, Chihway; Monstein, Christian; Amara, Adam; Refregier, Alexandre

    2016-07-01

    HIDE (HI Data Emulator) forward-models the process of collecting astronomical radio signals in a single dish radio telescope instrument and outputs pixel-level time-ordered-data. Written in Python, HIDE models the noise and RFI modeling of the data and with its companion code SEEK (ascl:1607.020) provides end-to-end simulation and processing of radio survey data.

  6. A method for distinguishing WW and NW in the flow around two side by side circular cylinders%并列双圆柱绕流中宽窄尾流的识别方法

    Institute of Scientific and Technical Information of China (English)

    庞建华; 宗智; 周力; 邹丽

    2016-01-01

    采用基于边界瞬时涡量守恒(IVCBC)的纯拉格朗日涡方法,结合并列双圆柱的结构特点,建立双圆柱绕流数值计算模型。在间隙率T/D=1.1~2.6时,并列双圆柱绕流会出现宽尾流(WW)和窄尾流(NW)现象。利用两圆柱间隙中心点的诱导速度方向与间隙流的偏转方向同步的特性,提出一种区别宽、窄尾流的数值计算方法;比较间隙流的偏转方向与该间隙中点的速度偏转方向,并进行典型的算例分析。结果表明:该方法能准确区别宽尾流和窄尾流,可为数值研究这一特殊区域的流体特征提供重要的数值计算方法。%A pure-Lagrangian vortex method, based on Instantaneous Vorticity Conserved Boundary Condi⁃tions (IVCBC), is adopted to build the numerical calculation model of flow around double circular cylinders that have the same structure characteristics of two side by side circular cylinders. The Wide Wake(WW) and Narrow Wake(NW)appear in the range of pitch ratio T/D=1.1~2.6. A scheme is proposed to distin⁃guish the NW and WW through the direction synchronism between induced velocity at the middle of double circular cylinders and deflection of gap flow. By comparing the directions of the above two flowing condi⁃tions and analyzing the classic case, it is concluded that the proposed method could distinguish WW and NW accurately, which offers an important numerical calculation method for investigating the flow character⁃istics in this range.

  7. Numerical simulation of laminar flow past two side-by-side cylinders by discontinuous Galerkin metho d%基于间断有限元方法的并列圆柱层流流动特性∗

    Institute of Scientific and Technical Information of China (English)

    张忠宇; 姚熊亮; 张阿漫

    2016-01-01

    基于高阶的间断有限元方法,数值模拟低马赫数下并列圆柱的可压缩层流流动,捕捉并列圆柱流场中的漩涡结构,以便分析并列圆柱尾流的流动特性。针对二维圆柱的边界形式,采用曲边三角形单元构造二维圆柱的曲面边界,以适应高阶离散格式的精度。在验证方法合理性的基础上,分析圆柱间距及雷诺数对漩涡脱落及受力特性的影响规律。研究结果表明:并列圆柱的间距是影响流场流动特性的一个主要因素,它会改变圆柱漩涡脱落的形式。随着圆柱间距的增加,上下圆柱的平均阻力系数及平均升力系数的绝对值随之显著下降。雷诺数对于平均阻力系数的影响相对较小。但随着雷诺数的增加,上下圆柱的平均升力系数会随之降低,而漩涡的脱落频率会随之增大。%Investigations of vortex dynamics about two circular cylinders in a side-by-side arrangement help the understanding of flows around more complex structures, which are found to have many engineering applications. These applications involve offshore structures, power generation, micro-turbine engines, cooling towers, and paper machine forming fabrics, etc. Therefore, two-dimensional compressible laminar flows over two cylinders in side-by-side arrangement are numerically investigated at low Reynolds number. The high-order discontinuous Galerkin method is employed to simulate the flow, which combines the advantages associated with finite element and finite volume methods. As in classical finite element method, the spatial accuracy can be obtained by the high-order polynomial approximation within an element rather than by stencils as in finite volume method. The curved triangle is used to represent the wall boundary of cylinder to maintain the high-order accurate simulation. Then the characteristics of the wake flow are identified by capturing the vortex structure. After verifying the rationality of

  8. Hiding dependence-discovery of F-hiding laws and system laws

    Institute of Scientific and Technical Information of China (English)

    Zhou Houyong; Huang Shunliang; Shi Kaiquan

    2009-01-01

    Function one direction S-rough sets have dynamic characteristics and law characteristics. By using the function one direction S-rough sets, this article presents the concepts of the f-hiding law, F-hiding law, f-hiding law dependence and F-hiding law dependence. Based on the concepts above, this article proposes the hiding-dependence theorem of f-hiding laws, the hiding-dependence theorem of F-hiding laws, the hiding-dependence separation theorem, the hiding dependencs-discovery principle of unknown laws. Finally, the application of the hiding dependence of hiding laws in the discovery of system laws is given.

  9. Hide receives the Bowie Medal

    Science.gov (United States)

    Dickey, Jean O.; Hide, Raymond

    The 1997 William Bowie Medal, given by AGU for outstanding contributions to fundamental geophysics and for unselfish cooperation in research, was presented to Raymond Hide at the AGU Spring Meeting Honor Ceremony on May 28 in Baltimore. The award citation and Hide's response are given here.

  10. Information Hiding Techniques: A Tutorial Review

    CERN Document Server

    Thampi, Sabu M

    2008-01-01

    The purpose of this tutorial is to present an overview of various information hiding techniques. A brief history of steganography is provided along with techniques that were used to hide information. Text, image and audio based information hiding techniques are discussed. This paper also provides a basic introduction to digital watermarking.

  11. Integrated Association Rules Complete Hiding Algorithms

    Directory of Open Access Journals (Sweden)

    Mohamed Refaat Abdellah

    2017-01-01

    Full Text Available This paper presents database security approach for complete hiding of sensitive association rules by using six novel algorithms. These algorithms utilize three new weights to reduce the needed database modifications and support complete hiding, as well as they reduce the knowledge distortion and the data distortions. Complete weighted hiding algorithms enhance the hiding failure by 100%; these algorithms have the advantage of performing only a single scan for the database to gather the required information to form the hiding process. These proposed algorithms are built within the database structure which enables the sanitized database to be generated on run time as needed.

  12. A Block Based Adaptive Video Data Hiding Method Using Forbidden Zone Data Hiding

    DEFF Research Database (Denmark)

    Banoth, Rajkumar

    2013-01-01

    -Data hiding is a process of embedding information into some sort of host media. Especially video data hiding has become an important research topic as it is complex when compared data hiding process in other media. This paper proposes a new method based on erasure correction capability of RA codes...... using forbidden zone data hiding. This method finds suitable host signals that are useful for data hiding. The proposed method also overcomes the problems of frame drop and inserts attacks. The simulation results reveal that this video data hiding framework can be used in data hiding applications...... of the real world. Key Words – RA codes, selective embedding, watermarking, forbidden zone data hiding, simulation, selective embedding, erasure handling, block partitioning...

  13. 穿梭油轮和浮式生产储油轮并靠作业过程中横荡方向运动和漂移力研究%Hydrodynamic Interactions on Sway Motions and Drift Forces Between Shuttle Tanker and FPSO Arranged Side-by-side

    Institute of Scientific and Technical Information of China (English)

    王洪超; 王磊; 邹刚

    2014-01-01

    文章针对穿梭油轮和浮式生产储油轮在并靠作业过程中在不同浪向和不同并靠间距情况下的船体一阶耦合运动及平均漂移力等水动力干扰情况进行了研究。通过研究发现,两船之间水动力干扰情况在不同的波浪频率区域,会出现放大或遮蔽效应,这与单浮体的水动力干扰情况有着很大的不同。计算结果表明由于另一浮体的存在,横荡平均漂移力不仅在大小上和单浮体水动力情况不同,而且在方向上也发生了改变。同时,鉴于横荡方向的运动和受力在动力定位控制系统中是非常重要的,该文可以为装有动力定位系统的穿梭油轮的安全作业,船体水动力干扰情况预测以及工程实践的初步设计提供相关参考和帮助。%In this paper, hydrodynamic interactions were studied between two floating bodies posi-tioned side-by-side as a shuttle tanker-FPSO (floating production, storage and offloading) system. Particular interest is placed on the sway coupled motions and mean drift forces with different sepa-ration distances and various wave directions. The results show that the hydrodynamics between two vessels is obviously distinguished from the single body case with shielding and exaggerating effects. In addition, the sway mean drift forces of multiple body case experience variations in both magnitude and direction compared with the single body case. As the sway motion is one of the most crucial com-ponents considered in DP (dynamic positioning) system, getting a better perspective of the sway mo-tion is beneficial for both the control of a shuttle tanker with DP system and the prediction of behav-ior of the vessels for safe operation. This paper is helpful to both prudent designs in the basic design stage and operations in engineering practice.

  14. Linear and Nonlinear Oblivious Data Hiding

    Directory of Open Access Journals (Sweden)

    Akansu Ali N

    2004-01-01

    Full Text Available The majority of the existing data hiding schemes are based on the direct-sequence (DS modulation where a low-power random sequence is embedded into the original cover signal to represent hidden information. In this paper, we investigate linear and nonlinear modulation approaches in digital data hiding. One typical DS modulation algorithm is explored and its optimal oblivious detector is derived. The results expose its poor cover noise suppression as the hiding signature signal always has much lower energy than the cover signal. A simple nonlinear algorithm, called set partitioning, is proposed and its performance is analyzed. Analysis and simulation studies further demonstrate improvements over the existing schemes.

  15. Recent Advances in Information Hiding and Applications

    CERN Document Server

    Huang, Hsiang-Cheh; Jain, Lakhmi; Zhao, Yao

    2013-01-01

    This research book presents a sample of recent advances in information hiding techniques and their applications. It includes:   Image data hiding scheme based on vector quantization and image graph coloring The copyright protection system for Android platform Reversible data hiding ICA-based image and video watermarking Content-based invariant image watermarking Single bitmap block truncation coding of color images using cat swarm optimization Genetic-based wavelet packet watermarking for copyright protection Lossless text steganography in compression coding Fast and low-distortion capacity acoustic synchronized acoustic-to-acoustic steganography scheme Video watermarking with shot detection

  16. Hiding Information into Palette-Based Image

    Institute of Scientific and Technical Information of China (English)

    WU Hong-tao; ZHU Bo-cheng; YANG Yi-xian

    2005-01-01

    After pointing out the weakness of the known palette-based image information hiding by palette matrix,a new spacial effective robust information hiding algorithm is proposed,which can resist the operation of ‘select all’,‘copy’,‘paste’ from cover to original,and can resist gently modification the palette matrix,and can resist the image format changed between true color image and palette-based image.The hiding capacity can reach 25% of the number of pixel index matrix.Due to the advisement of information hiding security an update algorithm is proposed at the end of the paper,with the capacity reduced and vision effect increased.

  17. 'Medical Tattoos' Help Hide Surgical Scars

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_161132.html 'Medical Tattoos' Help Hide Surgical Scars Pigments can restore more ... scars from cancer surgeries may benefit from "medical tattoos" that can help restore some of the skin's ...

  18. Hiding robot inertia using resonance.

    Science.gov (United States)

    Vallery, Heike; Duschau-Wicke, Alexander; Riener, Robert

    2010-01-01

    To enable compliant training modes with a rehabilitation robot, an important prerequisite is that any undesired human-robot interaction forces caused by robot dynamics must be avoided, either by an appropriate mechanical design or by compensating control strategies. Our recently proposed control scheme of "Generalized Elasticities" employs potential fields to compensate for robot dynamics, including inertia, beyond what can be done using closed-loop force control. In this paper, we give a simple mechanical equivalent using the example of the gait rehabilitation robot Lokomat. The robot consists of an exoskeleton that is attached to a frame around the patient's pelvis. This frame is suspended by a springloaded parallelogram structure. The mechanism allows vertical displacement while providing almost constant robot gravity compensation. However, inertia of the device when the patient's pelvis moves up and down remains a source of large interaction forces, which are reflected in increased ground reaction forces. Here, we investigate an alternative suspension: To hide not only gravity, but also robot inertia during vertical pelvis motion, we suspend the robot frame by a stiff linear spring that allows the robot to oscillate vertically at an eigenfrequency close to the natural gait frequency. This mechanism reduces human-robot interaction forces, which is demonstrated in pilot experimental results.

  19. Fully Traversable Wormholes Hiding Charge

    CERN Document Server

    Guendelman, Eduardo

    2012-01-01

    The charge-hiding effect by a wormhole, which was studied for the case where gravity/gauge-field system is self-consistently interacting with a charged lightlike brane (LLB) as a matter source, is now studied for the case of a time like brane. From the demand that no surfaces of infinite coordinate time redshift appear in the problem we are lead now to a completly traversable wormhole space, according to not only the traveller that goes through the wormhole (as was the case for the LLB), but also to a static external observer, this requires negative surface energy density for the shell sitting at the throat of the wormhole. We study a gauge field subsystem which is of a special non-linear form containing a square-root of the Maxwell term and which previously has been shown to produce a QCD-like confining gauge field dynamics in flat space-time. The condition of finite energy of the system or asymptotic flatness on one side of the wormhole implies that the charged object sitting at the wormhole throat expels a...

  20. Data Hiding in JPEG Images

    Directory of Open Access Journals (Sweden)

    Sushil Kumar

    2009-07-01

    perceptibility [5, 1].We shall use digital images as the cover object in this paper inwhich we embed the hidden information. The challenge ofusing steganography in cover images is to hide as much data aspossible with the least noticeable difference in the stego-image.Steganographic algorithms operate on basically three types ofimages: Raw images (i.e., bmp format, Palette based images(i.e., GIF images and JPEG images. JPEG images areroutinely used in Steganographic algorithms due to the mostpopular lossy image compression method. Usually it is foundthat an algorithm used to hide large amounts of informationtypically result in lower perceptibility (i.e., greater change tothe image appearance and a more robust algorithm result intolower embedding capacity. The JPEG image generation firstdecomposed the input image into a number of 8 x 8 blocks.Then DCT of each block are computed and the resultant DCTcoefficient matrix is quantized using a standard quantizationtable. Finally the inverse DCT of quantized coefficient matrixare evaluated and the final JPEG image is obtained afterrounding the values.

  1. Steganography An Art of Hiding Data

    CERN Document Server

    Channalli, Shashikala

    2009-01-01

    In today's world the art of sending & displaying the hidden information especially in public places, has received more attention and faced many challenges. Therefore, different methods have been proposed so far for hiding information in different cover media. In this paper a method for hiding of information on the billboard display is presented. It is well known that encryption provides secure channels for communicating entities. However, due to lack of covertness on these channels, an eavesdropper can identify encrypted streams through statistical tests and capture them for further cryptanalysis. In this paper we propose a new form of steganography, on-line hiding of information on the output screens of the instrument. This method can be used for announcing a secret message in public place. It can be extended to other means such as electronic advertising board around sports stadium, railway station or airport. This method of steganography is very similar to image steganography and video steganography. Pr...

  2. Short term preservation of hide using vacuum: influence on properties of hide and of processed leather.

    Science.gov (United States)

    Gudro, Ilze; Valeika, Virgilijus; Sirvaitytė, Justa

    2014-01-01

    The objective of this work was to investigate vacuum influence on hide preservation time and how it affects hide structure. It was established that vacuum prolongs the storage time without hide tissue putrefaction up to 21 days when the storage temperature is 4°C. The microorganisms act for all storage times, but the action is weak and has no observable influence on the quality of hide during the time period mentioned. The hide shrinkage temperature decrease is negligible, which shows that breaking of intermolecular bonds does not occur. Optical microscopy, infrared spectroscopy and differential scanning calorimetry also did not show any structural changes which can influence the quality of leather produced from such hide. The qualitative indexes of wet blue processed under laboratory conditions and of leather produced during industrial trials are presented. Indexes such as chromium compounds exhaustion, content of chromium in leather, content of soluble matter in dichloromethane, strength properties, and shrinkage temperature were determined. Properties of the leather produced from vacuumed hide under industrial conditions conformed to the requirements of shoe upper leather.

  3. Reversible Data Hiding Based on DNA Computing

    Directory of Open Access Journals (Sweden)

    Bin Wang

    2017-01-01

    Full Text Available Biocomputing, especially DNA, computing has got great development. It is widely used in information security. In this paper, a novel algorithm of reversible data hiding based on DNA computing is proposed. Inspired by the algorithm of histogram modification, which is a classical algorithm for reversible data hiding, we combine it with DNA computing to realize this algorithm based on biological technology. Compared with previous results, our experimental results have significantly improved the ER (Embedding Rate. Furthermore, some PSNR (peak signal-to-noise ratios of test images are also improved. Experimental results show that it is suitable for protecting the copyright of cover image in DNA-based information security.

  4. Preparation of biobased sponges from un-tanned hides

    Science.gov (United States)

    One of our research endeavors to address ongoing challenges faced by the U.S. hide and leather industries is to develop innovative uses and novel biobased products from hides to improve prospective markets and to secure a viable future for hides and leather industries. We had previously investigate...

  5. Hiding an Inconvenient Truth : Lies and Vagueness

    NARCIS (Netherlands)

    Serra Garcia, M.; van Damme, E.E.C.; Potters, J.J.M.

    2010-01-01

    When truth conflicts with e¢ ciency, can verbal communication destroy efficiency? Or are lies or vagueness used to hide inconvenient truths? We consider a sequential 2-player public good game in which the leader has private information about the value of the public good. This value can be low, high,

  6. Hiding levitating objects above a ground plane

    DEFF Research Database (Denmark)

    Zhang, Jingjing; Luo, Yu; Mortensen, Asger

    2010-01-01

    An approach to hiding objects levitating above a conducting sheet is suggested in this paper. The proposed device makes use of isotropic negative-refractive-index materials without extreme material parameters, and creates an illusion of a remote conducting sheet. Numerical simulations are perform...

  7. An Approach to Hide Secret Speech Information

    Institute of Scientific and Technical Information of China (English)

    WU Zhi-jun; DUAN Hai-xin; LI Xing

    2006-01-01

    This paper presented an approach to hide secret speech information in code excited linear prediction(CELP)-based speech coding scheme by adopting the analysis-by-synthesis (ABS)-based algorithm of speech information hiding and extracting for the purpose of secure speech communication. The secret speech is coded in 2.4Kb/s mixed excitation linear prediction (MELP), which is embedded in CELP type public speech. The ABS algorithm adopts speech synthesizer in speech coder. Speech embedding and coding are synchronous, i.e. a fusion of speech information data of public and secret. The experiment of embedding 2.4 Kb/s MELP secret speech in G.728 scheme coded public speech transmitted via public switched telephone network (PSTN) shows that the proposed approach satisfies the requirements of information hiding, meets the secure communication speech quality constraints, and achieves high hiding capacity of average 3.2 Kb/s with an excellent speech quality and complicating speakers' recognition.

  8. Understanding Information Hiding in iOS

    OpenAIRE

    Caviglione, Luca; Mazurczyk, Wojciech

    2014-01-01

    The Apple operating system (iOS) has so far proved resistant to information-hiding techniques, which help attackers covertly communicate. However, Siri - a native iOS service that controls iPhones and iPads via voice commands - could change this trend.

  9. An Approach for Message Hiding using Substitution Techniques and Audio Hiding in Steganography

    CERN Document Server

    Mukhopadhyay, Debajyoti; Ghosh, Surjya; Biswas, Sudipto; Chakraborty, Poulami

    2011-01-01

    A crypto system can be used to encrypt messages sent between two communicating parties so that an eavesdropper who overhears the encrypted messages will not be able to decode them. The paper mainly concentrates on the method in which the substitution technique of steganography can been used to hide data in a 24-bit bitmap file. Popular audio hiding techniques based on methods of steganography is also discussed here.

  10. Information Hiding Using Improper Frame Padding

    CERN Document Server

    Jankowski, Bartosz; Szczypiorski, Krzysztof

    2010-01-01

    Hiding information in network traffic may lead to leakage of confidential information. In this paper we introduce a new steganographic system: the PadSteg (Padding Steganography). To authors' best knowledge it is the first information hiding solution which represents interprotocol steganography i.e. usage of relation between two or more protocols from the TCP/IP stack to enable secret communication. PadSteg utilizes ARP and TCP protocols together with an Etherleak vulnerability (improper Ethernet frame padding) to facilitate secret communication for hidden groups in LANs (Local Area Networks). Basing on real network traces we confirm that PadSteg is feasible in today's networks and we estimate what steganographic bandwidth is achievable while limiting the chance of disclosure. We also point at possible countermeasures against PadSteg.

  11. Estimation of Information Hiding Algorithms and Parameters

    Science.gov (United States)

    2007-02-21

    growing false positives. 15. SUBJECT TERMS Information hiding, reverse-engineering, steganography , steganalysis, watermarking 16. SECURITY...specialist in breaking a covert communication system given very little information. Since it is likely for steganography to be used on very large...multimedia files, e.g. audio and video, there are substantial issues to be addressed on the implementation end of such a system as well as the theoretical

  12. S-rough sets and the discovery of F-hiding knowledge

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Singular rough sets (S-rough sets) have three classes of forms: one-directional S-rough sets, dual of one-directional S-rough sets, and two-directional S-rough sets. Dynamic, hereditary, mnemonic, and hiding properties are the basic characteristics of S-rough sets. By using the S-rough sets, the concepts of f-hiding knowledge, F-hiding knowledge, hiding degree, and hiding dependence degree are given. Then, both the hiding theorem and the hiding dependence theorem of hiding knowledge are proposed. Finally, an application of hiding knowledge is discussed.

  13. Minimax eigenvector decomposition for data hiding

    Science.gov (United States)

    Davidson, Jennifer

    2005-09-01

    Steganography is the study of hiding information within a covert channel in order to transmit a secret message. Any public media such as image data, audio data, or even file packets, can be used as a covert channel. This paper presents an embedding algorithm that hides a message in an image using a technique based on a nonlinear matrix transform called the minimax eigenvector decomposition (MED). The MED is a minimax algebra version of the well-known singular value decomposition (SVD). Minimax algebra is a matrix algebra based on the algebraic operations of maximum and addition, developed initially for use in operations research and extended later to represent a class of nonlinear image processing operations. The discrete mathematical morphology operations of dilation and erosion, for example, are contained within minimax algebra. The MED is much quicker to compute than the SVD and avoids the numerical computational issues of the SVD because the operations involved only integer addition, subtraction, and compare. We present the algorithm to embed data using the MED, show examples applied to image data, and discuss limitations and advantages as compared with another similar algorithm.

  14. Augmented Reality Marker Hiding with Texture Deformation.

    Science.gov (United States)

    Kawai, Norihiko; Sato, Tomokazu; Nakashima, Yuta; Yokoya, Naokazu

    2016-10-19

    Augmented reality (AR) marker hiding is a technique to visually remove AR markers in a real-time video stream. A conventional approach transforms a background image with a homography matrix calculated on the basis of a camera pose and overlays the transformed image on an AR marker region in a real-time frame, assuming that the AR marker is on a planar surface. However, this approach may cause discontinuities in textures around the boundary between the marker and its surrounding area when the planar surface assumption is not satisfied. This paper proposes a method for AR marker hiding without discontinuities around texture boundaries even under nonplanar background geometry without measuring it. For doing this, our method estimates the dense motion in the marker's background by analyzing the motion of sparse feature points around it, together with a smooth motion assumption, and deforms the background image according to it. Our experiments demonstrate the effectiveness of the proposed method in various environments with different background geometries and textures.

  15. Enhancement of LSB based Steganography for Hiding Image in Audio

    OpenAIRE

    Pradeep Kumar Singh; R.K.Aggrawal

    2010-01-01

    In this paper we will take an in-depth look on steganography by proposing a new method of Audio Steganography. Emphasize will be on the proposed scheme of image hiding in audio and its comparison with simple Least Significant Bit insertion method for data hiding in audio.

  16. Selective Redundancy Removal: A Framework for Data Hiding

    Directory of Open Access Journals (Sweden)

    Ugo Fiore

    2010-02-01

    Full Text Available Data hiding techniques have so far concentrated on adding or modifying irrelevant information in order to hide a message. However, files in widespread use, such as HTML documents, usually exhibit high redundancy levels, caused by code-generation programs. Such redundancy may be removed by means of optimization software. Redundancy removal, if applied selectively, enables information hiding. This work introduces Selective Redundancy Removal (SRR as a framework for hiding data. An example application of the framework is given in terms of hiding information in HTML documents. Non-uniformity across documents may raise alarms. Nevertheless, selective application of optimization techniques might be due to the legitimate use of optimization software not supporting all the optimization methods, or configured to not use all of them.

  17. Information hiding in communication networks fundamentals, mechanisms, applications, and countermeasures

    CERN Document Server

    Mazurczyk, Wojciech; Zander, Sebastian; Houmansadr, Amir; Szczypiorski, Krzysztof

    2016-01-01

    Describes Information Hiding in communication networks, and highlights their important issues, challenges, trends, and applications. This book provides the fundamental concepts, terminology, and classifications of information hiding in communication networks along with its historical background. Information Hiding In Communication Networks: Fundamentals, Mechanisms, Applications, and Countermeasures begins with introducing data concealment methods and their evolution. Chapter two discusses the existing terminology and describes the model for hidden communication and related communication scenarios. Chapters three to five present the main classes of information hiding in communication networks accompanied by a discussion of their robustness and undetectability. The book concludes with a discussion of potential countermeasures against information hiding techniques, which includes different types of mechanisms for the detection, limitation and prevention of covert co munication channels.

  18. Beam characteristics in two different proton uniform scanning systems: A side-by-side comparison

    Energy Technology Data Exchange (ETDEWEB)

    Nichiporov, Dmitri; Hsi Wen; Farr, Jonathan [Indiana University Integrated Science and Accelerator Technology Hall, 2401 Milo B. Sampson Lane, Bloomington, Indiana 47408 (United States); ProCure Treatment Centers, Inc., 420 North Walnut Street, Bloomington, Indiana 47401 (United States); Westdeutsches Protonentherapiezentrum, Hufelandstr. 55, Essen, NRW 45147 (Germany)

    2012-05-15

    Purpose: To compare clinically relevant dosimetric characteristics of proton therapy fields produced by two uniform scanning systems that have a number of similar hardware components but employ different techniques of beam spreading. Methods: This work compares two technologically distinct systems implementing a method of uniform scanning and layer stacking that has been developed independently at Indiana University (IU) and by Ion Beam Applications, S. A. (IBA). Clinically relevant dosimetric characteristics of fields produced by these systems are studied, such as beam range control, peak-to-entrance ratio (PER), lateral penumbra, field flatness, effective source position, precision of dose delivery at different gantry angles, etc. Results: Under comparable conditions, both systems controlled beam range with an accuracy of 0.5 mm and a precision of 0.1 mm. Compared to IBA, the IU system produced pristine peaks with a slightly higher PER (3.23 and 3.45, respectively) and smaller, symmetrical, lateral in-air penumbra of 1 mm compared to about 1.9/2.4 mm in the inplane/crossplane (IP/CP) directions for IBA. Large field flatness results in the IP/CP directions were similar: 3.0/2.4% for IU and 2.9/2.4% for IBA. The IU system featured a longer virtual source-to-isocenter position, which was the same for the IP and CP directions (237 cm), as opposed to 212/192 cm (IP/CP) for IBA. Dose delivery precision at different gantry angles was higher in the IBA system (0.5%) than in the IU system (1%). Conclusions: Each of the two uniform scanning systems considered in this work shows some attractive performance characteristics while having other features that can be further improved. Overall, radiation field characteristics of both systems meet their clinical specifications and show comparable results. Most of the differences observed between the two systems are clinically insignificant.

  19. Side-by-side comparison of gene-based smallpox vaccine with MVA in nonhuman primates.

    Directory of Open Access Journals (Sweden)

    Joseph W Golden

    Full Text Available Orthopoxviruses remain a threat as biological weapons and zoonoses. The licensed live-virus vaccine is associated with serious health risks, making its general usage unacceptable. Attenuated vaccines are being developed as alternatives, the most advanced of which is modified-vaccinia virus Ankara (MVA. We previously developed a gene-based vaccine, termed 4pox, which targets four orthopoxvirus antigens, A33, B5, A27 and L1. This vaccine protects mice and non-human primates from lethal orthopoxvirus disease. Here, we investigated the capacity of the molecular adjuvants GM-CSF and Escherichia coli heat-labile enterotoxin (LT to enhance the efficacy of the 4pox gene-based vaccine. Both adjuvants significantly increased protective antibody responses in mice. We directly compared the 4pox plus LT vaccine against MVA in a monkeypox virus (MPXV nonhuman primate (NHP challenge model. NHPs were vaccinated twice with MVA by intramuscular injection or the 4pox/LT vaccine delivered using a disposable gene gun device. As a positive control, one NHP was vaccinated with ACAM2000. NHPs vaccinated with each vaccine developed anti-orthopoxvirus antibody responses, including those against the 4pox antigens. After MPXV intravenous challenge, all control NHPs developed severe disease, while the ACAM2000 vaccinated animal was well protected. All NHPs vaccinated with MVA were protected from lethality, but three of five developed severe disease and all animals shed virus. All five NHPs vaccinated with 4pox/LT survived and only one developed severe disease. None of the 4pox/LT-vaccinated animals shed virus. Our findings show, for the first time, that a subunit orthopoxvirus vaccine delivered by the same schedule can provide a degree of protection at least as high as that of MVA.

  20. Side by Side: What a Comparative Usability Study Told Us about a Web Site Redesign

    Science.gov (United States)

    Dougan, Kirstin; Fulton, Camilla

    2009-01-01

    Library Web sites must compete against easy-to-use sites, such as Google Scholar, Google Books, and Wikipedia, for students' time and attention. Library Web sites must therefore be designed with aesthetics and user perceptions at the forefront. The Music and Performing Arts Library at Urbana-Champaign's Web site was overcrowded and in much need of…

  1. Coaching Side by Side: One-on-One Collaboration Creates Caring, Connected Teachers

    Science.gov (United States)

    Akhavan, Nancy

    2015-01-01

    This article describes a school district administrator's research on optimal coaching experiences for classroom teachers. This research was done with the intent of gaining a better understanding of how coaching affects student learning. The author defines coaching as the assistance given to a teacher to improve on teaching practices in order to…

  2. Side-by-Side Comparison of Hydroperoxide and Corresponding Alcohol as Hydrogen-Bond Donors

    DEFF Research Database (Denmark)

    Møller, Kristian Holten; Tram, Camilla Mia; Kjærgaard, Henrik Grum

    2017-01-01

    tert-butanol (t-BuOH), with dimethyl ether (DME) as the hydrogen-bond acceptor. Using a combination of Fourier-transform infrared spectroscopy and quantum chemical calculations, we compare the strength of the OH-O hydrogen bond and the total strength of complexation. We find that, both in terms...

  3. Moon Zoo: Educating side-by-side with Doing Science (Invited)

    Science.gov (United States)

    Gay, P. L.; Moon Zoo Team

    2010-12-01

    The Moon Zoo citizen science project (http://www.moonzoo.org) engages individuals - primarily members of the public - in identifying geological (and sometimes technological) features on the lunar surface. Using a flash-based interface that runs in a web browser, users can mark craters, linear features, and even left-behind lunar landers on Lunar Reconnaissance Orbiter images. These science tools are embedded in an environment designed to encourage learning and collaboration. On the main Moon Zoo site users can explore educational content, including video tutorials, articles, glossary terms, and flash interactive activities. Additionally, there is a blog and a forum to encourage collaboration and social learning, and a twitter feed for general communications. Through this suite of software Moon Zoo users can contribute to science while learning about the Moon and geology. The Moon Zoo educational content is designed with one purpose in mind: To make sure that a curious user can find information quickly, easily, and on (or within 1-click of) the Moon Zoo site. The Internet is filled with many excellent lunar educational products, and many high-quality digital products exist in offline archives. Finding desired resources, however, can sometimes be a challenge even for professional educators. In order to make finding content easier, we developed a glossary list and a basic concept map for our website that addresses geology, lunar exploration, observing, and the moon in history and culture, and then we populated these terms and concepts with already available materials. We also do things in a way that encourages both doing science tasks and learning at the same time! Specifically, we use pop-out audio and video players that allow users to listen, learn, and classify the lunar surface all at once. To try and understand our users better we are conducting both learning and motivations studies while also monitoring site usage. Our learning assessments use an assessment tool designed by Sebastien Cormier and Ed Prather. At the time of this writing, data collection is still in progress. We are asking users with a variety of different experience levels within Moon Zoo to answer concept questions to assess if we can measure a higher conceptual knowledge in people who have spent more time in Moon Zoo and see change over time in individual users. We are also doing interview-based grounded theory investigations into what motivates people to come to Moon Zoo and to continue using the site. Preliminary results of the investigations will be presented, along with user behaviors, and other website statistics-based research. This work is funded through NASA ROSES grant NNX09AD34G and NSF grant DRL-0917608.

  4. Side-by-Side Testing of Water Heating Systems: Results from the 2013-2014 Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Colon, Carlos [Florida Solar Energy Center, Cocoa, FL (United States). Bulding America Partnership for Improved Residential Construction

    2017-07-12

    The Florida Solar Energy Center (FSEC) has completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). This report contains a summary of research activities regarding the evaluation of two residential electric heat pump water heaters (HPWHs), a solar thermal system utilizing a polymer glazed absorber and a high efficiency natural gas system.

  5. A side-by-side comparison of Daya Bay antineutrino detectors

    CERN Document Server

    An, F P; Bai, J Z; Balantekin, A B; Band, H R; Beriguete, W; Bishai, M; Blyth, S; Brown, R L; Cao, G F; Cao, J; Carr, R; Chang, J F; Chang, Y; Chasman, C; Chen, H S; Chen, S J; Chen, S M; Chen, X C; Chen, X H; Chen, X S; Chen, Y; Cherwinka, J J; Chu, M C; Cummings, J P; Deng, Z Y; Ding, Y Y; Diwan, M V; Draeger, E; Du, X F; Dwyer, D; Edwards, W R; Ely, S R; Fang, S D; Fu, J Y; Fu, Z W; Ge, L Q; Gill, R L; Gonchar, M; Gong, G H; Gong, H; Gornushkin, Y A; Greenler, L S; Gu, W Q; Guan, M Y; Guo, X H; Hackenburg, R W; Hahn, R L; Hans, S; Hao, H F; He, M; He, Q; He, W S; Heeger, K M; Heng, Y K; Hinrichs, P; Ho, T H; Hor, Y K; Hsiung, Y B; Hu, B Z; Hu, T; Hu, T; Huang, H X; Huang, H Z; Huang, P W; Huang, X; Huang, X T; Huber, P; Jaffe, D E; Jetter, S; Ji, X L; Ji, X P; Jiang, H J; Jiang, W Q; Jiao, J B; Johnson, R A; Kang, L; Kettell, S H; Kramer, M; Kwan, K K; Kwok, M W; Kwok, T; Lai, C Y; Lai, W C; Lai, W H; Lau, K; Lebanowski, L; Lee, M K P; Leitner, R; Leung, J K C; Leung, K Y; Lewis, C A; Li, F; Li, G S; Li, J; Li, Q J; Li, S F; Li, W D; Li, X B; Li, X N; Li, X Q; Li, Y; Li, Z B; Liang, H; Lin, C J; Lin, G L; Lin, S K; Lin, S X; Lin, Y C; Ling, J J; Link, J M; Littenberg, L; Littlejohn, B R; Liu, B J; Liu, D W; Liu, J C; Liu, J L; Liu, S; Liu, X; Liu, Y B; Lu, C; Lu, H Q; Luk, A; Luk, K B; Luo, X L; Ma, L H; Ma, Q M; Ma, X Y; Ma, Y Q; Mayes, B; McDonald, K T; McFarlane, M C; McKeown, R D; Meng, Y; Mohapatra, D; Nakajima, Y; Napolitano, J; Naumov, D; Nemchenok, I; Newsom, C; Ngai, H Y; Ngai, W K; Nie, Y B; Ning, Z; Ochoa-Ricoux, J P; Olshevski, A; Pagac, A; Patton, S; Pec, V; Peng, J C; Piilonen, L E; Pinsky, L; Pun, C S J; Qi, F Z; Qi, M; Qian, X; Rosero, R; Roskovec, B; Ruan, X C; Seilhan, B; Shao, B B; Shih, K; Steiner, H; Stoler, P; Sun, G X; Sun, J L; Tam, Y H; Tanaka, H K; Tang, X; Torun, Y; Trentalange, S; Tsai, O; Tsang, K V; Tsang, R H M; Tull, C; Viren, B; Vorobel, V; Wang, C H; Wang, L S; Wang, L Y; Wang, M; Wang, N Y; Wang, R G; Wang, W; Wang, X; Wang, Y F; Wang, Z; Wang, Z; Wang, Z M; Webber, D M; Wei, Y D; Wen, L J; Wenman, D L; Whisnant, K; White, C G; Whitehead, L; Wilhelmi, J; Wise, T; Wong, H L H; Wong, J; Wu, F F; Wu, Q; Xi, J B; Xia, D M; Xiao, Q; Xing, Z Z; Xu, G; Xu, J; Xu, J; Xu, J L; Xu, Y; Xue, T; Yang, C G; Yang, L; Ye, M; Yeh, M; Yeh, Y S; Young, B L; Yu, Z Y; Zhan, L; Zhang, C; Zhang, F H; Zhang, J W; Zhang, Q M; Zhang, S H; Zhang, Y C; Zhang, Y H; Zhang, Y X; Zhang, Z J; Zhang, Z P; Zhang, Z Y; Zhao, H; Zhao, J; Zhao, Q W; Zhao, Y B; Zheng, L; Zhong, W L; Zhou, L; Zhou, Y Z; Zhou, Z Y; Zhuang, H L; Zou, J H

    2012-01-01

    The Daya Bay Reactor Neutrino Experiment is designed to determine precisely the neutrino mixing angle $\\theta_{13}$ with a sensitivity better than 0.01 in the parameter sin$^22\\theta_{13}$ at the 90% confidence level. To achieve this goal, the collaboration will build eight functionally identical antineutrino detectors. The first two detectors have been constructed, installed and commissioned in Experimental Hall 1, with steady data-taking beginning September 23, 2011. A comparison of the data collected over the subsequent three months indicates that the detectors are functionally identical, and that detector-related systematic uncertainties exceed requirements.

  6. A side-by-side comparison of Daya Bay antineutrino detectors

    Energy Technology Data Exchange (ETDEWEB)

    An, F.P. [Institute of High Energy Physics, Beijing (China); An, Q. [University of Science and Technology of China, Hefei (China); Bai, J.Z. [Institute of High Energy Physics, Beijing (China); Balantekin, A.B.; Band, H.R. [Department of Physics, University of Wisconsin, Madison, WI (United States); Beriguete, W.; Bishai, M. [Brookhaven National Laboratory, Upton, NY (United States); Blyth, S. [National United University, Miao-Li, Taiwan (China); Brown, R.L. [Brookhaven National Laboratory, Upton, NY (United States); Cao, G.F. [Institute of High Energy Physics, Beijing (China); Cao, J., E-mail: caoj@ihep.ac.cn [Institute of High Energy Physics, Beijing (China); Carr, R. [California Institute of Technology, Pasadena, CA (United States); Chang, J.F. [Institute of High Energy Physics, Beijing (China); Chang, Y. [National United University, Miao-Li, Taiwan (China); Chasman, C. [Brookhaven National Laboratory, Upton, NY (United States); Chen, H.S. [Institute of High Energy Physics, Beijing (China); Chen, S.J. [Nanjing University, Nanjing (China); Chen, S.M. [Department of Engineering Physics, Tsinghua University, Beijing (China); Chen, X.C. [Chinese University of Hong Kong (Hong Kong); Chen, X.H. [Institute of High Energy Physics, Beijing (China); and others

    2012-09-01

    The Daya Bay Reactor Neutrino Experiment is designed to determine precisely the neutrino mixing angle {theta}{sub 13} with a sensitivity better than 0.01 in the parameter sin{sup 2}2{theta}{sub 13} at the 90% confidence level. To achieve this goal, the collaboration will build eight functionally identical antineutrino detectors. The first two detectors have been constructed, installed and commissioned in Experimental Hall 1, with steady data-taking beginning September 23, 2011. A comparison of the data collected over the subsequent three months indicates that the detectors are functionally identical, and that detector-related systematic uncertainties are smaller than requirements.

  7. Side-by-side comparison of areas with and without cellulite depressions using magnetic resonance imaging.

    Science.gov (United States)

    Hexsel, Doris Maria; Abreu, Marcelo; Rodrigues, Ticiana C; Soirefmann, Mariana; do Prado, Débora Zechmeister; Gamboa, Maryelle Moreira Lima

    2009-10-01

    Cellulite is characterized by alterations in the relief of the skin surface. Magnetic resonance imaging (MRI) is recognized as a reliable technique for measuring adipose volume according to body site and for the visualization of the subcutaneous structures. To compare subcutaneous tissue in areas with and without cellulite on the buttocks of same subjects using a noninvasive technique. Thirty female patients with cellulite on the buttocks underwent MRI. An area with cellulite and another without cellulite on the contralateral buttock were selected. Two soft gelatin capsules of different sizes were used as skin markers to differentiate the areas with and without cellulite. Fibrous septa were visualized in 96.7% of the area with cellulite depressions; most of them were ramified (73.3%) and presented a high-intensity signal on T2 images (70%). All fibrous septa found in the examined areas were perpendicular to the skin surface. The average fibrous septa thickness was 2.18 +/- 0.89 in the area with cellulite and 0.27 +/- 0.64 in the area without cellulite. Results of the MRI analysis showed that cellulite depressions on the buttocks were significantly associated with the presence of underlying fibrous septa.

  8. Side-by-Side Field Evaluation of Highly Insulating Windows in the PNNL Lab Homes

    Energy Technology Data Exchange (ETDEWEB)

    Widder, Sarah H.; Parker, Graham B.; Baechler, Michael C.; Bauman, Nathan N.

    2012-08-01

    To examine the energy, air leakage, and thermal performance of highly insulating windows, a field evaluation was undertaken in a matched pair of all-electric, factory-built “Lab Homes” located on the Pacific Northwest National Laboratory (PNNL) campus in Richland, Washington. The “baseline” Lab Home B was retrofitted with “standard” double-pane clear aluminum-frame slider windows and patio doors, while the “experimental” Lab Home A was retrofitted with Jeld-Wen® triple-pane vinyl-frame slider windows and patio doors with a U-factor of 0.2 and solar heat gain coefficient of 0.19. To assess the window, the building shell air leakage, energy use, and interior temperatures of each home were compared during the 2012 winter heating and summer cooling seasons. The measured energy savings in Lab Home B averaged 5,821 watt-hours per day (Wh/day) during the heating season and 6,518 Wh/day during the cooling season. The overall whole-house energy savings of Lab Home B compared to Lab Home A are 11.6% ± 1.53% for the heating season and 18.4 ± 2.06% for the cooling season for identical occupancy conditions with no window coverings deployed. Extrapolating these energy savings numbers based on typical average heating degree days and cooling degree days per year yields an estimated annual energy savings of 12.2%, or 1,784 kWh/yr. The data suggest that highly insulating windows are an effective energy-saving measure that should be considered for high-performance new homes and in existing retrofits. However, the cost effectiveness of the measure, as determined by the simple payback period, suggests that highly insulating window costs continue to make windows difficult to justify on a cost basis alone. Additional reductions in costs via improvements in manufacturing and/or market penetration that continue to drive down costs will make highly insulating windows much more viable as a cost-effective energy efficiency measure. This study also illustrates that highly insulating windows have important impacts on peak load, occupant comfort, and condensation potential, which are not captured in the energy savings calculation. More consistent and uniform interior temperature distributions suggest that highly insulated windows, as part of a high performance building envelope, may enable more centralized duct design and downsized HVAC systems. Shorter, more centralized duct systems and smaller HVAC systems to yield additional cost savings, making highly insulating windows more cost effective as part of a package of new construction or retrofit measures which achieve significant reductions in home energy use.

  9. Addressing global challenges side by side-Interview with MPS President Prof. Peter Gruss

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Prof. Peter Gruss, president of the Max Planck Society (MPS) and a winner of China's National Award for International S&T Cooperation in 2007, has long been committed to promoting the scientific cooperation between China and Germany. As early as in the 1980s, he went to Shanghai to teach advanced experimental techniques at the Guest Laboratory cosponsored by CAS and MPS. Since 2002 when he assumed the office of MPS president,

  10. Measured Performance of Occupied, Side-by-Side, South Texas Homes

    Energy Technology Data Exchange (ETDEWEB)

    Chasar, Dave; vonSchramm, Valerie

    2012-09-01

    The performance of three homes in San Antonio, Texas with identical floor plans and orientation were evaluated through a partnership between the Florida Solar Energy Center (FSEC), CPS Energy, and Woodside Homes of South Texas. Measurements included whole house gas and electric use as well as heating, cooling, hot water, major appliances and indoor and outdoor conditions. One home built to builder standard practice served as the control, while the other homes demonstrated high performance features. Utility peak electric load comparisons of these dual-fuel homes provide an assessment of envelope and equipment improvements.

  11. Measured Performance of Occupied, Side-by-Side, South Texas Homes

    Energy Technology Data Exchange (ETDEWEB)

    Chasar, D.; vonSchramm, V.

    2012-09-01

    The performance of three homes in San Antonio, Texas with identical floor plans and orientation were evaluated through a partnership between the Florida Solar Energy Center (FSEC), CPS Energy, and Woodside Homes of South Texas. Measurements included whole house gas and electric use as well as heating, cooling, hot water, major appliances and indoor and outdoor conditions. One home built to builder standard practice served as the control, while the other homes demonstrated high performance features. Utility peak electric load comparisons of these dual-fuel homes provide an assessment of envelope and equipment improvements. The control home used natural gas for space and water heating only, while the improved homes had gas heating and major appliances with the exception of a high efficiency heat pump in one home. Data collection began in July of 2009 and continued through April of 2011. Energy ratings for the homes yielded E-Scales (aka HERS indices) of 86 for the control home, 54 for one improved home and 37 for the other home which has a 2.4kW photovoltaic array.

  12. Side-by-Side Comparison of Gene-Based Smallpox Vaccine with MVA in Nonhuman Primates

    Science.gov (United States)

    Golden, Joseph W.; Josleyn, Matthew; Mucker, Eric M.; Hung, Chien-Fu; Loudon, Peter T.; Wu, T. C.; Hooper, Jay W.

    2012-01-01

    Orthopoxviruses remain a threat as biological weapons and zoonoses. The licensed live-virus vaccine is associated with serious health risks, making its general usage unacceptable. Attenuated vaccines are being developed as alternatives, the most advanced of which is modified-vaccinia virus Ankara (MVA). We previously developed a gene-based vaccine, termed 4pox, which targets four orthopoxvirus antigens, A33, B5, A27 and L1. This vaccine protects mice and non-human primates from lethal orthopoxvirus disease. Here, we investigated the capacity of the molecular adjuvants GM-CSF and Escherichia coli heat-labile enterotoxin (LT) to enhance the efficacy of the 4pox gene-based vaccine. Both adjuvants significantly increased protective antibody responses in mice. We directly compared the 4pox plus LT vaccine against MVA in a monkeypox virus (MPXV) nonhuman primate (NHP) challenge model. NHPs were vaccinated twice with MVA by intramuscular injection or the 4pox/LT vaccine delivered using a disposable gene gun device. As a positive control, one NHP was vaccinated with ACAM2000. NHPs vaccinated with each vaccine developed anti-orthopoxvirus antibody responses, including those against the 4pox antigens. After MPXV intravenous challenge, all control NHPs developed severe disease, while the ACAM2000 vaccinated animal was well protected. All NHPs vaccinated with MVA were protected from lethality, but three of five developed severe disease and all animals shed virus. All five NHPs vaccinated with 4pox/LT survived and only one developed severe disease. None of the 4pox/LT-vaccinated animals shed virus. Our findings show, for the first time, that a subunit orthopoxvirus vaccine delivered by the same schedule can provide a degree of protection at least as high as that of MVA. PMID:22860117

  13. Side-by-side Intercomparison for OVOC at Hohenpeissenberg Meteorological Observatory (DWD)

    Science.gov (United States)

    Englert, Jennifer; Claude, Anja; Plass-Duelmer, Christian; Kubistin, Dagmar

    2016-04-01

    Oxygenated volatile organic compounds are difficult to measure in atmospheric samples due to their low mixing ratios in the low ppt to ppb range, their polarity and associated stickiness to surfaces, and their partly high water solubility. Thus, it is not surprising that occasionally co-located instruments with "similar" measurement techniques obtain considerably different results. With focus on high-quality measurements, the need of a better characterisation of measurement techniques has been identified in GAW VOC Expert meetings. This has been addressed in the tasks of the EU infrastructure project ACTRIS and ACTRIS-2. Seven groups with ten different state-of-the-art OVOC instruments (PTR-MS, GC/MS/FID, adsorbent tube sampler and DNPH cartridges) took part in a joint field and laboratory intercomparison campaign at the Hohenpeissenberg Meteorological Observatory in October 2013. All instruments were connected to a single manifold which was fed with synthetic air mixtures, zero air, pure and spiked ambient air at controlled ozone and humidity levels. Compared to a previous intercomparison at the SAPHIR chamber in Juelich (Apel et al., 2008), the Hohenpeissenberg OVOC intercomparison expanded the range of tested mixing ratios down to the low ppt range and included synthetic and ambient air at OVOC mixing ratios of mostly below 1 ppb, for many compounds even below 100 ppt. Thus, the instruments were tested under typical clean air conditions encountered at the stations of the monitoring networks of GAW and EMEP enabling a full characterization of the detection limits, linear ranges, and potential artefacts. Our results show both consistent results between different instruments albeit using different techniques, and partly clear deviations of individual or groups of instruments. These deviations were further analysed with respect to reference concentrations, characteristics of the respective techniques, blank and calibration issues and uncertainties.

  14. Directionally hiding objects and creating illusions above a carpet-like device by reflection holography

    Science.gov (United States)

    Cheng, Qiluan; Wu, Kedi; Shi, Yile; Wang, Hui; Wang, Guo Ping

    2015-02-01

    Realization of a perfect invisibility cloak still challenges the current fabricating technologies. Most experiments, if not all, are hence focused on carpet cloaks because of their relatively low requirements to material properties. Nevertheless, present invisibility carpets are used to hide beneath objects. Here, we report a carpet-like device to directionally conceal objects and further to create illusions above it. The device is fabricated through recording a reflection hologram of objects and is used to produce a time-reversed signal to compensate for the information of the objects and further to create light field of another object so as to realize both functions of hiding the objects and creating illusions, respectively. The carpet-like device can work for macroscopic objects at visible wavelength as the distance between objects and device is at decimeter scale. Our carpet-like device to realizing invisibility and creating illusions may provide a robust way for crucial applications of magic camouflaging and anti-detection etc.

  15. Determinism beneath Quantum Mechanics

    CERN Document Server

    Hooft, G

    2002-01-01

    Contrary to common belief, it is not difficult to construct deterministic models where stochastic behavior is correctly described by quantum mechanical amplitudes, in precise accordance with the Copenhagen-Bohr-Bohm doctrine. What is difficult however is to obtain a Hamiltonian that is bounded from below, and whose ground state is a vacuum that exhibits complicated vacuum fluctuations, as in the real world. Beneath Quantum Mechanics, there may be a deterministic theory with (local) information loss. This may lead to a sufficiently complex vacuum state, and to an apparent non-locality in the relation between the deterministic ("ontological") states and the quantum states, of the kind needed to explain away the Bell inequalities. Theories of this kind would not only be appealing from a philosophical point of view, but may also be essential for understanding causality at Planckian distance scales.

  16. Where is hbar Hiding in Entropic Gravity?

    CERN Document Server

    Chen, Pisin

    2011-01-01

    The entropic gravity scenario recently proposed by Erik Verlinde reproduced the Newton's law of purely classical gravity yet the key assumptions of this approach all have quantum mechanical origins. This is atypical for emergent phenomena in physics, where the underlying, more fundamental physics often reveals itself as corrections to the leading classical behavior. So one naturally wonders: where is hbar hiding in entropic gravity? To address this question, we first revisit the idea of holographic screen as well as entropy and its variation law in order to obtain a self-consistent approach to the problem. Next we argue that when dealing with quantum gravity issues the generalized uncertainty principle (GUP) should be the more appropriate foundation. Indeed based on GUP it has been demonstrated that the black hole Bekenstein entropy area law must be modified not only in the strong but also in the weak gravity regime. In the weak gravity limit, such a GUP modified entropy exhibits a logarithmic correction term...

  17. Hiding secret data into a carrier image

    Directory of Open Access Journals (Sweden)

    Ovidiu COSMA

    2012-06-01

    Full Text Available The object of steganography is embedding hidden information in an appropriate multimedia carrier, e.g., image, audio, or video. There are several known methods of solving this problem, which operate either in the space domain or in the frequency domain, and are distinguished by the following characteristics: payload, robustness and strength. The payload is the amount of secret data that can be embedded in the carrier without inducing suspicious artefacts, robustness indicates the degree in which the secret data is affected by the normal processing of the carrier e.g., compression, and the strength indicate how easy the presence of hidden data can be detected by steganalysis techniques. This paper presents a new method of hiding secret data into a digital image compressed by a technique based on the Discrete Wavelet Transform (DWT [2] and the Set Partitioning In Hierarchical Trees (SPIHT subband coding algorithm [6]. The proposed method admits huge payloads and has considerable strength.

  18. Hiding Quantum Information in the Perfect Code

    CERN Document Server

    Shaw, Bilal A

    2010-01-01

    We present and analyze a protocol for quantum steganography where the sender (Alice) encodes her steganographic information into the error syndromes of the perfect (five-qubit) quantum error-correcting code, and sends it to the receiver (Bob) over a depolarizing channel. Alice and Bob share a classical secret key, and hide quantum information in such a way that to an eavesdropper (Eve) without access to the secret key, the quantum message looks like an innocent codeword with a typical sequence of quantum errors. We calculate the average rate of key consumption, and show how the protocol improves in performance as information is spread over multiple codeword blocks. Alice and Bob utilize different encodings to optimize the average number of steganographic bits that they can send to each other while matching the error statistics of the depolarizing channel.

  19. Multimedia Data Hiding and Authentication via Halftoning and Coordinate Projection

    Directory of Open Access Journals (Sweden)

    Wu Chai Wah

    2002-01-01

    Full Text Available We present image data hiding and authentication schemes based on halftoning and coordinate projection. The proposed data hiding scheme can embed images of the same size and similar bit depth into the cover image and robustness against compression is demonstrated. The image authentication scheme is based on the data hiding scheme and can detect, localize, and repair the tampered area of the image. Furthermore, the self-repairing feature of the authentication scheme has a hologram-like quality; any portion of the image can be used to reconstruct the entire image, with a greater quality of reconstruction as the portion size increases.

  20. Mechanical properties of biobased films prepared from collagen solutions derived from bovine hides

    Science.gov (United States)

    The most valuable byproducts of the meat packing industry are hides. The U.S. is the world’s 3rd largest hide producing country and currently produces approximately 35 million cattle hides annually. Due to fierce competition in global markets, the American leather and hides industry is facing chal...

  1. Hide and New in the Pi-Calculus

    Directory of Open Access Journals (Sweden)

    Marco Giunti

    2012-08-01

    Full Text Available In this paper, we enrich the pi-calculus with an operator for confidentiality (hide, whose main effect is to restrict the access to the object of the communication, thus representing confidentiality in a natural way. The hide operator is meant for local communication, and it differs from new in that it forbids the extrusion of the name and hence has a static scope. Consequently, a communication channel in the scope of a hide can be implemented as a dedicated channel, and it is more secure than one in the scope of a new. To emphasize the difference, we introduce a spy context that represents a side-channel attack and breaks some of the standard security equations for new. To formally reason on the security guarantees provided by the hide construct, we introduce an observational theory and establish stronger equivalences by relying on a proof technique based on bisimulation semantics.

  2. A Data-reversible Hiding Algorithm in WSNs

    Directory of Open Access Journals (Sweden)

    Jia CHEN

    2013-09-01

    Full Text Available In view of the phenomenon that data-hiding algorithm is easy to be detected by inspecting tool SPAM when carrying information, random insertion and histogram modification are adapted in the data hiding. A data-reversible hiding algorithm in WSNs is put forward. By collecting and referring sub-graph, calculating data fusion algorithm that can protect the data’s completion and privacy and analyzing the reversible hiding data algorithm research, the inspection of SPAM. Finally MATLAB7.0 exploitation is adopted to stimulate the analysis of experiment. The result shows that compared with Kim algorithm, the algorithm is safer to prevent the SPAM inspection and is more suitable for information transfer.

  3. Legionnaires' Hiding in Hospital, Nursing Home Plumbing Systems: CDC

    Science.gov (United States)

    ... gov/news/fullstory_166302.html Legionnaires' Hiding in Hospital, Nursing Home Plumbing Systems: CDC Effective water management, sanitation programs can reduce the risk of exposure to this deadly bacteria To use the sharing ...

  4. A Simple Image Encoding Method with Data Lossless Information Hiding

    OpenAIRE

    Zhi-Hui Wang; Chin-Chen Chang; Ming-Chu Li; Tzu-Chuen Lu

    2011-01-01

    In this paper, we propose a simple reversible data hiding method in the spatial domain for block truncation coding (BTC) compressed grayscale images. The BTC method compresses a block of a grayscale image to a bitmap and a pair of quantization numbers. The proposed method first embeds secret bits into a block by changing the order of those two quantization numbers. The compression rate is not enlarged by this embedding scheme. To further improve the hiding capacity, the proposed method embeds...

  5. Information hiding techniques for steganography and digital watermarking

    CERN Document Server

    Katzenbeisser, Stefan

    2000-01-01

    Steganography, a means by which two or more parties may communicate using ""invisible"" or ""subliminal"" communication, and watermarking, a means of hiding copyright data in images, are becoming necessary components of commercial multimedia applications that are subject to illegal use. This new book is the first comprehensive survey of steganography and watermarking and their application to modern communications and multimedia.Handbook of Information Hiding: Steganography and Watermarking helps you understand steganography, the history of this previously neglected element of cryptography, the

  6. A chaos-based approach for information hiding security

    OpenAIRE

    Bahi, Jacques M.; Guyeux, Christophe

    2010-01-01

    This paper introduces a new framework for data hiding security. Contrary to the existing ones, the approach introduced here is not based on probability theory. In this paper, a scheme is considered as secure if its behavior is proven unpredictable. The objective of this study is to enrich the existing notions of data hiding security with a new rigorous and practicable one. This new definition of security is based on the notion of topological chaos. It could be used to reinforce the confidence...

  7. Let’s play hide and seek!

    CERN Multimedia

    Computer Security Team

    2012-01-01

    This week, we would like you to play a small online game called “Virtual Hide & Seek”. The rules are simple: some of our colleagues have published some sensitive or confidential documents on CERN’s central services like Indico, CDS, EDMS or TWiki, as well as on our many websites. Your mission, should you choose to accept it: find them!   If you provide us with documents marked “confidential”, “classified”, “sensitive”, or containing plain text operational passwords, you can win a book on computer security. There are only few conditions: these documents must be visible from outside CERN, must not require a CERN account in order to access them, and must not belong to you or have a direct link with your work. Have fun! But seriously, are you sure that your documents are really properly protected? We regularly find confidential documents stored on one of the CERN central  services and w...

  8. Book Review: No Place To Hide

    Directory of Open Access Journals (Sweden)

    Gary Kessler

    2007-03-01

    Full Text Available O'Harrow, R., Jr. (2006. No Place To Hide. New York: Free Press. 352 pages, ISBN: 0-7432-8705-3 (paper, US$26Reviewed by Gary C. Kessler (gary.kessler@champlain.eduPersonal privacy and the protection of personal identifying information are of concern to all of us. Innumerable articles and conferences address our loss of privacy, either through the sale of consumer databases or our own inattention. Opinions vary from "You have no privacy; get over it" to "This is the end of civil liberties as we know them." We teach people to safely maneuver on the Internet and minimize their exposure to bogus sites set up to steal their identity, warn users about the dangers of phishing and posting personal information on social network sites, use firewalls to protect our databases, and enact laws such as the Health Insurance Portability and Accountability Act (HIPAA and the Family Educational Rights and Privacy Act (FERPA to protect information.(see PDF for full review

  9. [Rapid quantification of total nitrogen and end-point determination of hide melting in manufacturing of donkey-hide gelatin].

    Science.gov (United States)

    Han, Hai-Fan; Zhang, Lu; Zhang, Yan; Li, Wen-Long; Qu, Hai-Bin

    2014-03-01

    Hide melting presents itself as one of the most critical processes in the production of donkey-hide gelatin. Here a NIR-based method was established for the rapid analysis of in-process hide melting solutions as well as for end-point determination of this process. Near infrared (NIR) spectra of hide melting solutions were collected in transflective mode. With the contents of total nitrogen determined by the Kjeldahl method as reference values, partial least squares regression (PLSR) was employed to build calibration models between NIR spectra and total nitrogen. Model parameters including wavelength range and PLS factors were optimized to achieve best model performance. Based on the contents of total nitrogen predicted by calibration model, end point of hide melting was determined. The constructed PLS model gave a high correlation coefficient (R2) of 0.991 3 and a root mean square error of prediction (RMSEP) of 0.807 g x L(-1). With the predicted total nitrogen and predefined limit, decisions concerning the proper times of melting were made. This research demonstrated that NIR transflectance spectroscopy could be used to expeditiously determine the contents of total nitrogen which was subsequently chosen as the indictor for determining the end-point of hide melting. The proposed procedure may help avoid unnecessary raw material or energy consumption.

  10. A Game of Hide and Seek: Expectations of Clumpy Resources Influence Hiding and Searching Patterns.

    Directory of Open Access Journals (Sweden)

    Andreas Wilke

    Full Text Available Resources are often distributed in clumps or patches in space, unless an agent is trying to protect them from discovery and theft using a dispersed distribution. We uncover human expectations of such spatial resource patterns in collaborative and competitive settings via a sequential multi-person game in which participants hid resources for the next participant to seek. When collaborating, resources were mostly hidden in clumpy distributions, but when competing, resources were hidden in more dispersed (random or hyperdispersed patterns to increase the searching difficulty for the other player. More dispersed resource distributions came at the cost of higher overall hiding (as well as searching times, decreased payoffs, and an increased difficulty when the hider had to recall earlier hiding locations at the end of the experiment. Participants' search strategies were also affected by their underlying expectations, using a win-stay lose-shift strategy appropriate for clumpy resources when searching for collaboratively-hidden items, but moving equally far after finding or not finding an item in competitive settings, as appropriate for dispersed resources. Thus participants showed expectations for clumpy versus dispersed spatial resources that matched the distributions commonly found in collaborative versus competitive foraging settings.

  11. A Game of Hide and Seek: Expectations of Clumpy Resources Influence Hiding and Searching Patterns.

    Science.gov (United States)

    Wilke, Andreas; Minich, Steven; Panis, Megane; Langen, Tom A; Skufca, Joseph D; Todd, Peter M

    2015-01-01

    Resources are often distributed in clumps or patches in space, unless an agent is trying to protect them from discovery and theft using a dispersed distribution. We uncover human expectations of such spatial resource patterns in collaborative and competitive settings via a sequential multi-person game in which participants hid resources for the next participant to seek. When collaborating, resources were mostly hidden in clumpy distributions, but when competing, resources were hidden in more dispersed (random or hyperdispersed) patterns to increase the searching difficulty for the other player. More dispersed resource distributions came at the cost of higher overall hiding (as well as searching) times, decreased payoffs, and an increased difficulty when the hider had to recall earlier hiding locations at the end of the experiment. Participants' search strategies were also affected by their underlying expectations, using a win-stay lose-shift strategy appropriate for clumpy resources when searching for collaboratively-hidden items, but moving equally far after finding or not finding an item in competitive settings, as appropriate for dispersed resources. Thus participants showed expectations for clumpy versus dispersed spatial resources that matched the distributions commonly found in collaborative versus competitive foraging settings.

  12. Alkali-free method of hide preparation for tanning

    Directory of Open Access Journals (Sweden)

    V. Valeika

    2012-06-01

    Full Text Available Usually, beamhouse processes are carried out by varying a medium from strongly alkaline (unhairing-liming up to strongly acid (pickling. This study is designed to develop a preparation of hide for tanning via processes that avoid a sharp change of hide pH. Enzymes active in acid medium are employed for hide unhairing in a buffer system containing 2.5% acetic acid and 0.3% sodium acetate. An oxidative treatment with peracetic acid then allows the complete removal of residual hair and scud. During both processes, unhairing and oxidative treatment, the opening of the derma structure occurs: 13.3-14.6g of non-collagen proteins are removed and amount of dermatan sulphate decreases by 35%. The hide obtained can be chromed directly after the above processes and subsequent treatment with sodium chloride solution omitted conventional pickling. The pH of the hide varies in the range of 8.3-3.7 during the processes of preparation for tanning.

  13. Hiding image to video: A new approach of LSB replacement

    Directory of Open Access Journals (Sweden)

    Saurabh Singh,

    2010-12-01

    Full Text Available Steganography has become great area of interest for researchers as need for secure transaction of information is increasing day by day. Information may be text, image, audio or video. Steganography is a technique in which required information is hided in any other information such that the second information does not change significantly and it appears the same as original. This paper presents a novel approach of hiding image in a video. The proposed algorithm is replacing one LSB of each pixel in video frames. It becomes very difficult for intruder to guess that an image is hidden in the video as individual frames are very difficult to analyze in a video running at 30 frames per second. The process of analysis has been made more difficult by hiding each row of image pixels in multiple frames of the video, so intruder cannot even try to unhide image until he get full video.

  14. EFFICIENT METHOD FOR HIDING DATA BY PIXEL INTENSITY

    Directory of Open Access Journals (Sweden)

    M.Shobana

    2013-02-01

    Full Text Available Data communication substructure has become more universal that there is absolutely no favoritism between different types of data in the carry plane of communication with each and every one skilled to carry it through the public data networks. Steganography technique is used to hide or embed data into an image or audio or video. Here the cover object used is an image. In the existing method for hiding and extraction of information from the given image three kinds of algorithm are used, based on its data and index channel of an image. In the proposed system, three kinds of hiding technique are implemented with some modifications in the logic level. Third algorithm is designed using color channels, based on its intensity. This technique would boost up the number of bits embedding in the image. The accomplishment of all the three algorithms are analyzed and the efficient one is taken into consideration while implementing in FPGA.

  15. Capacity bounds and constructions for reversible data-hiding

    Science.gov (United States)

    Kalker, Ton; Willems, Frans M. J.

    2003-06-01

    An undesirable side effect of many watermarking and data-hiding schemes is that the host signal into which auxiliary data is embedded is distorted. Finding an optimal balance between the amount of information embedded and the induced distortion is therefore an active field of research. In recent years, with the rediscovery of Costa's seminal paper Writing on Dirty Paper, there has been considerable progress in understanding the fundamental limits of the capacity versus distortion of watermarking and data-hiding schemes. For some applications, however, no distortion resulting from auxiliary data, however small, is allowed. In these cases the use of reversible data-hiding methods provide a way out. A reversible data-hiding scheme is defined as a scheme that allows complete and blind restoration (i.e. without additional signaling) of the original host data. Practical reversible data-hiding schemes have been proposed by Fridrich et al., but little attention has been paid to the theoretical limits. Some first results on the capacity of reversible watermarking schemes have been derived. The reversible schemes considered in most previous papers have a highly fragile nature: in those schemes, changing a single bit in the watermarked data would prohibit recovery of both the original host signal as well as the embedded auxiliary data. It is the purpose of this paper to repair this situation and to provide some first results on the limits of robust reversible data-hiding. Admittedly, the examples provided in this paper are toy examples, but they are indicative of more practical schemes that will be presented in subsequent papers.

  16. Selective adsorption of tannins onto hide collagen fibres

    Institute of Scientific and Technical Information of China (English)

    LIAO; Xuepin(廖学品); LU; Zhongbing(陆忠兵); SHI; Bi(石碧)

    2003-01-01

    Hide collagen of animals is used to prepare adsorbent material and its adsorption properties to tannins are investigated. It is indicated that the collagen fibres has excellent adsorption selectivity and high adsorption capacity to tannins. The adsorption rate of tannins is more than 90% whilst less than 10% of functional components are retained by the adsorbent. The adsorption mechanism of tannins onto hide collagen fibres is hydrogen-bonding association. Freundlich model can be used to describe the adsorption isotherms, and the pseudo-second-order rate model can be used to describe adsorption kinetics.

  17. Competitively coupled maps for hiding secret visual information

    Science.gov (United States)

    Vaidelys, M.; Ziaukas, P.; Ragulskis, M.

    2016-02-01

    A novel digital image hiding scheme based on competitively coupled maps is presented in this paper. Self-organizing patterns produced by an array of non-diffusively coupled nonlinear maps are exploited to conceal the secret. The secret image is represented in the form of a dot-skeleton representation and is embedded into a spatially homogeneous initial state far below the noise level. Self-organizing patterns leak the secret image at a predefined set of system parameters. Computational experiments are used to demonstrate the effectiveness and the security of the proposed image hiding scheme.

  18. 9 CFR 95.6 - Untanned hides and skins; importations permitted subject to restrictions.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Untanned hides and skins; importations... ENTRY INTO THE UNITED STATES § 95.6 Untanned hides and skins; importations permitted subject to restrictions. Hides or skins offered for importation which do not meet the conditions or requirements of §...

  19. 9 CFR 95.5 - Untanned hides and skins; requirements for unrestricted entry.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Untanned hides and skins; requirements... ENTRY INTO THE UNITED STATES § 95.5 Untanned hides and skins; requirements for unrestricted entry. Untanned hides and/or skins of cattle, buffalo, sheep, goats, other ruminants, and swine which do not...

  20. The physical properties, morphology and viscoelasticity of biobased sponges prepared from un-tanned hides

    Science.gov (United States)

    One of our research endeavors to address ongoing challenges faced by the U.S. hide and leather industries is to develop innovative uses and novel biobased products from hides to improve prospective markets and to secure a viable future for hides and leather industries. We had previously investigate...

  1. The prediction of leather mechanical properties from airborne ultrasonic testing of hides

    Science.gov (United States)

    High quality, clean, and well-preserved hides are paramount for competitiveness in both domestic and export markets. Currently, hides are visually inspected and ranked for quality and sale price, which is not reliable when hair is present on the hides. Advanced technologies are needed to nondestru...

  2. Performance Analysis of Data Hiding in MPEG-4 AAC Audio

    Institute of Scientific and Technical Information of China (English)

    XU Shuzheng; ZHANG Peng; WANG Pengjun; YANG Huazhong

    2009-01-01

    A high capacity data hiding technique was developed for compressed digital audio.As perceptual audio coding has become the accepted technology for storage and transmission of audio signals,compressed audio information hiding enables robust,imperceptible transmission of data within audio signals,thus allowing valuable information to be attached to the content,such as the song title,lyrics,composer's name,and artist or property rights related data.This paper describes simultaneous low bitrate encoding and information hiding for highly compressed audio signals.The information hiding is implemented in the quantization process of the audio content which improves robustness,signal quality,and security.The imperceptibility of the embedded data is ensured based on the masking property of the human auditory system (HAS).The robustness and security are evaluated by various attacking algorithms.Tests with an extended MPEG4 advanced audio coding (AAC) encoder confirm that the method is robust to the regular and singular groups method (RS) and sample pair analysis (SPA) attacks as well as other statistical steganalysis method attacks.

  3. DCT Based Secret Image Hiding In Video Sequence

    Directory of Open Access Journals (Sweden)

    M. Suresh Kumar

    2014-08-01

    Full Text Available Internet which is ever more accessible to interference by not with authority people over the World. It is important to bring down a chance of Information being sensed while Transmitting is the major issue these days. To overcome these problems one of the solution is cryptography. There will be no solitude once it is decoded. So hiding data to make it confidential. Copyright is one of the ways for hiding data and it is security for digital media. Its significance and techniques used in executing hiding of data let us see in brief. The existing LSB modification technique as in this approach the bits are randomly distributes the bits of message in image so which will becomes complex for anonymous persons to extract original message information, it opens the gates for loosing important hidden information. Here hiding and extraction method is used for AVI (Audio Video Interleave. As Higher order coefficients maintains Secret message bits. The hidden information will be in the form of gray scale image pixel values. Grayscale value then converted into binary values .The resultant binary values will be assigned to the higher order coefficient values of DCT of AVI video frames. These experiments were successful. We can analyze the results using Mat lab simulation software.

  4. Video Steganography: Text Hiding In Video By LSB Substitution

    Directory of Open Access Journals (Sweden)

    Kamred Udham Singh

    2014-05-01

    Full Text Available The development of high speed computer networks and Internet has increased the easiness of Information Communication. In contrast with Analog media and Digital media provide several different advantages such as high quality, simple editing, high loyalty copying and authenticity. But in the field of data communication this type of development has increased the fear of sneaking the data while sending data from the sender to the receiver. Due to this reason Information Security is main problem of Data Communication. Steganography plays an important role in field of Information Security. Video and images are very common choice for hiding data. It is very important for effective and successful embedding process to select appropriate pixels in the video frames, which are used to store the secret data. We use video based Steganography because of large size and memory requirements. Hiding information in a carrier file we use least significant bit (LSB insertion technique. In Least significant bit (LSB insertion technique, for hiding information we change LSB of video file with the information bits .This paper will focus on hiding information in specific frames of the video and in specific position of the frame by LSB substitution.

  5. Hide And Seek GPS And Geocaching In The Classroom

    Science.gov (United States)

    Lary, Lynn M.

    2004-01-01

    In short, geocaching is a high-tech, worldwide treasure hunt (geocaches can now be found in more than 180 countries) where a person hides a cache for others to find. Generally, the cache is some type of waterproof container that contains a log book and an assortment of goodies, such as lottery tickets, toys, photo books for cachers to fill with…

  6. Powdered hide model for vegetable tanning II. hydrolyzable tannin

    Science.gov (United States)

    Vegetable tannages employ both condensed and hydrolyzable tannins. As part of our exploration of tanning mechanisms, we reported last year on interactions of the condensed tannin, quebracho, with powdered hide. In this study, the interactions of chestnut extract, a hydrolyzable tannin, with powdere...

  7. Near Reversible Data Hiding Scheme for images using DCT

    Directory of Open Access Journals (Sweden)

    T. Bhaskar

    2015-11-01

    Full Text Available Certain level of modifications to the original content can be acceptable. These schemes are called nearreversible. It has emerging application in remote sensing. In remote sensing application the image is captured while monitoring the damaged regions in the natural disasters such as tsunami, volcanic eruption, etc. Instead of more alterations to the pixels or coefficients here we go for less alterations , low hiding capacity and complexity that exhibit while reversible data hiding. There exist a few near reversible hiding schemes which address the limitations to the triangular trade-off that exists between capacity, robustness and visual quality characteristics. However, for achieving better vision of image, there is a need for near reversible data hiding schemes. Therefore, the traditional metric PSNR are not sufficient to assess the distorted image when the data is embedded in image for assessing the better visual quality of the image with hidden data we present a HVS based metrics like PSNR-HVS, MSSIM. Using DCT evaluates the overall image quality

  8. PALM and STORM: what hides beyond the Rayleigh limit?

    CSIR Research Space (South Africa)

    Henriques, R

    2009-06-01

    Full Text Available -1 Biotechnol. J. 2009, 4, 846?857 Review PALM and STORM: What hides beyond the Rayleigh limit? Ricardo Henriques1 and Musa M. Mhlanga1,2 1 Gene Expression and Biophysics Unit, Instituto de Medicina Molecular, Faculdade de Medicina Universidade de...

  9. Video Data Hiding for Managing Privacy Information in Surveillance Systems

    Directory of Open Access Journals (Sweden)

    Hail MichaelW

    2009-01-01

    Full Text Available From copyright protection to error concealment, video data hiding has found usage in a great number of applications. In this work, we introduce the detailed framework of using data hiding for privacy information preservation in a video surveillance environment. To protect the privacy of individuals in a surveillance video, the images of selected individuals need to be erased, blurred, or re-rendered. Such video modifications, however, destroy the authenticity of the surveillance video. We propose a new rate-distortion-based compression-domain video data hiding algorithm for the purpose of storing that privacy information. Using this algorithm, we can safeguard the original video as we can reverse the modification process if proper authorization can be established. The proposed data hiding algorithm embeds the privacy information in optimal locations that minimize the perceptual distortion and bandwidth expansion due to the embedding of privacy data in the compressed domain. Both reversible and irreversible embedding techniques are considered within the proposed framework and extensive experiments are performed to demonstrate the effectiveness of the techniques.

  10. Quiz Games as a model for Information Hiding

    OpenAIRE

    Bank, Bernd; Heintz, Joos; Matera, Guillermo; Montana, Jose L.; Pardo, Luis M.; Paredes, Andres Rojas

    2015-01-01

    We present a general computation model inspired in the notion of information hiding in software engineering. This model has the form of a game which we call quiz game. It allows in a uniform way to prove exponential lower bounds for several complexity problems of elimination theory.

  11. Frequent Itemset Hiding Algorithm Using Frequent Pattern Tree Approach

    Science.gov (United States)

    Alnatsheh, Rami

    2012-01-01

    A problem that has been the focus of much recent research in privacy preserving data-mining is the frequent itemset hiding (FIH) problem. Identifying itemsets that appear together frequently in customer transactions is a common task in association rule mining. Organizations that share data with business partners may consider some of the frequent…

  12. Frequent Itemset Hiding Algorithm Using Frequent Pattern Tree Approach

    Science.gov (United States)

    Alnatsheh, Rami

    2012-01-01

    A problem that has been the focus of much recent research in privacy preserving data-mining is the frequent itemset hiding (FIH) problem. Identifying itemsets that appear together frequently in customer transactions is a common task in association rule mining. Organizations that share data with business partners may consider some of the frequent…

  13. Joint data-hiding and rate-distortion optimization for H.264/AVC videos

    Science.gov (United States)

    Lin, Yih-Chuan; Li, Jung-Hong

    2012-07-01

    We address video data-hiding on the context-adaptive variable-length coding domain of the H.264/AVC standard. It is challenging to maintain a minimum variation of rate-distortion performance when hiding data in compressed videos by slightly modifying one or more transform coefficients of prediction residual data. The fluctuant variation of rate-distortion performance is especially serious in the case of hiding data in H.264/AVC compressed videos due to the thorough use of various prediction modes. Most current video data-hiding schemes concentrate on hiding messages in video intra (I)-frames to mitigate performance degradation at the expense of limited hiding capacity and applicability. Unlike most previous video data-hiding schemes, this paper considers data-hiding schemes on both I- and predicted (P)-frames of videos. We first investigate the possible ways used to suppress the significant degradation of the rate-distortion performance for hiding data in H.264/AVC videos. Based on the investigation, a hybrid video data-hiding scheme is designed to perform the classification of 4×4 residual blocks according to the characteristics of each block and to hide message data differently in each classified block in order to reduce the performance degradation caused by the data-hiding process. The block classification is based on the magnitude of the last non-zero coefficient and the coefficient difference energy of each block to select suitable blocks that are capable of contributing less degradation of coding performance for hiding additional messages. Moreover, the proposed data-hiding algorithm is incorporated with the rate-distortion optimization loop of the H.264/AVC encoder to provide further degradation suppression on the output bit-rate and decoded quality. From experiments on several well-known test videos, it can be seen that the proposed data-hiding scheme demonstrates improved efficiency on video quality and output bit-rate compared to other similar methods.

  14. Optical image hiding based on computational ghost imaging

    Science.gov (United States)

    Wang, Le; Zhao, Shengmei; Cheng, Weiwen; Gong, Longyan; Chen, Hanwu

    2016-05-01

    Imaging hiding schemes play important roles in now big data times. They provide copyright protections of digital images. In the paper, we propose a novel image hiding scheme based on computational ghost imaging to have strong robustness and high security. The watermark is encrypted with the configuration of a computational ghost imaging system, and the random speckle patterns compose a secret key. Least significant bit algorithm is adopted to embed the watermark and both the second-order correlation algorithm and the compressed sensing (CS) algorithm are used to extract the watermark. The experimental and simulation results show that the authorized users can get the watermark with the secret key. The watermark image could not be retrieved when the eavesdropping ratio is less than 45% with the second-order correlation algorithm, whereas it is less than 20% with the TVAL3 CS reconstructed algorithm. In addition, the proposed scheme is robust against the 'salt and pepper' noise and image cropping degradations.

  15. Hiding a Realistic Object Using a Broadband Terahertz Invisibility Cloak

    CERN Document Server

    Zhou, Fan; Cao, Wei; Stuart, Colin T; Gu, Jianqiang; Zhang, Weili; Sun, Cheng

    2011-01-01

    The invisibility cloak has been a long-standing dream for many researchers over the decades. The introduction of transformational optics has revitalized this field by providing a general method to design material distributions to hide the subject from detection. By transforming space and light propagation, a three-dimensional (3D) object is perceived as having a reduced number of dimensions, in the form of points, lines, and thin sheets, making it "undetectable" judging from the scattered field. Although a variety of cloaking devices have been reported at microwave and optical frequencies, the spectroscopically important Terahertz (THz) domain remains unexplored. Moreover, due to the difficulties in fabricating cloaking devices that are optically large in all three dimensions, hiding realistic 3D objects has yet to be demonstrated. Here, we report the first experimental demonstration of a 3D THz cloaking device fabricated using a scalable Projection Microstereolithography process. The cloak operates at a broa...

  16. Steganography Algorithm to Hide Secret Message inside an Image

    CERN Document Server

    Ibrahim, Rosziati

    2011-01-01

    In this paper, the authors propose a new algorithm to hide data inside image using steganography technique. The proposed algorithm uses binary codes and pixels inside an image. The zipped file is used before it is converted to binary codes to maximize the storage of data inside the image. By applying the proposed algorithm, a system called Steganography Imaging System (SIS) is developed. The system is then tested to see the viability of the proposed algorithm. Various sizes of data are stored inside the images and the PSNR (Peak signal-to-noise ratio) is also captured for each of the images tested. Based on the PSNR value of each images, the stego image has a higher PSNR value. Hence this new steganography algorithm is very efficient to hide the data inside the image.

  17. The effect of media on knowledge hiding in entrepreneurial firms

    DEFF Research Database (Denmark)

    Labafi, Somayeh; Khajeheian, Datis; Williams, Idongesit

    2017-01-01

    in a qualitative study. Thematic analysis is used to analyze transcribed interview data from employees in a software company in Iran. The findings of the analysis show that media richness significantly impacts on organizational learning and influences on knowledge hiding behavior in employees. This article...... suggests that entrepreneurs and managers of small firms should provide employees’ access to rich media content as well as established organizational learning as part of their organizational culture........ For this reason, factors that influence on the tendency of employees to expose and use their knowledge would be appreciated by managers of organizations. This paper investigates the effect of the media on knowledge hiding in organizations. The investigation is done with the aid of a conceptual framework...

  18. Robust color image hiding method in DCT domain

    Institute of Scientific and Technical Information of China (English)

    LI Qing-zhong; YU Chen; CHU Dong-sheng

    2006-01-01

    This paper presents a robust color image hiding method based on YCbCr color system in discrete cosine transform (DCT) domain,which can hide a secret color image behind a public color cover image and is compatible with the international image compression standard of JPEG.To overcome the grave distortion problem in the restored secret image,this paper proposes a new embedding scheme consisting of reasonable partition of a pixel value and sign embedding.Moreover,based on human visual system (HVS) and fuzzy theory,this paper also presents a fuzzy classification method for DCT sub-blocks to realize the adaptive selection of embedding strength.The experimental results show that the maximum distortion error in pixel value for the extracted secret image is ±1.And the color cover image can provide good quality after embedding large amount of data.

  19. Hiding an image in cascaded Fresnel digital holograms

    Institute of Scientific and Technical Information of China (English)

    Shaogeng Deng; Liren Liu; Haitao Lang; Weiqing Pan; Dong Zhao

    2006-01-01

    @@ A system of two separated computer-generated holograms termed cascaded Fresnel digital holography (CFDH) is proposed and its application to hiding information is demonstrated by a computer simulation experiment. The technique is that the reconstructed image is the result of the wave Fresnel diffractionof two sub-holograms located at different distances from the imaging plane along the illuminating beam. The two sub-holograms are generated by an iterative algorithm based on the projection onto convex sets. In the application to the hiding of optical information, the information to be hidden is encoded into thesub-hologram which is multiplied by the host image in the input plane, the other sub-hologram in the filterplane is used for the deciphering key, the hidden image can be reconstructed in the imaging plane of the CFDH setup.

  20. Potential methane reservoirs beneath Antarctica.

    Science.gov (United States)

    Wadham, J L; Arndt, S; Tulaczyk, S; Stibal, M; Tranter, M; Telling, J; Lis, G P; Lawson, E; Ridgwell, A; Dubnick, A; Sharp, M J; Anesio, A M; Butler, C E H

    2012-08-30

    Once thought to be devoid of life, the ice-covered parts of Antarctica are now known to be a reservoir of metabolically active microbial cells and organic carbon. The potential for methanogenic archaea to support the degradation of organic carbon to methane beneath the ice, however, has not yet been evaluated. Large sedimentary basins containing marine sequences up to 14 kilometres thick and an estimated 21,000 petagrams (1 Pg equals 10(15) g) of organic carbon are buried beneath the Antarctic Ice Sheet. No data exist for rates of methanogenesis in sub-Antarctic marine sediments. Here we present experimental data from other subglacial environments that demonstrate the potential for overridden organic matter beneath glacial systems to produce methane. We also numerically simulate the accumulation of methane in Antarctic sedimentary basins using an established one-dimensional hydrate model and show that pressure/temperature conditions favour methane hydrate formation down to sediment depths of about 300 metres in West Antarctica and 700 metres in East Antarctica. Our results demonstrate the potential for methane hydrate accumulation in Antarctic sedimentary basins, where the total inventory depends on rates of organic carbon degradation and conditions at the ice-sheet bed. We calculate that the sub-Antarctic hydrate inventory could be of the same order of magnitude as that of recent estimates made for Arctic permafrost. Our findings suggest that the Antarctic Ice Sheet may be a neglected but important component of the global methane budget, with the potential to act as a positive feedback on climate warming during ice-sheet wastage.

  1. Crustal structure beneath Eastern Greenland

    DEFF Research Database (Denmark)

    Reiche, Sönke; Thybo, H.; Kaip, G.

    2011-01-01

    is recorded by 350 Reftek Texan receivers for 10 equidistant shot points along the profile. We use forward ray tracing modelling to construct a two-dimensional velocity model from the observed travel times. These results show the first images of the subsurface velocity structure beneath the Greenland ice...... these mountain belts is needed for assessing the isostatic balance of the crust and to gain insight into possible links between crustal composition, rifting history and present-day topography of the North Atlantic Region. However, the acquisition of geophysical data onshore Greenland is logistically complicated...

  2. A NEW APPROACH FOR HIDING DATA USING B-BOX

    Directory of Open Access Journals (Sweden)

    Dr. Saad Abdual azize AL_ani

    2013-11-01

    Full Text Available Digital Images and video encryption play an important role in today’s multimedia world. Many encryption schemes have been proposed to provide a security for digital images. This paper designs an efficient cryptosystem for video. Our method can achieve two goals; the first goal is to design a height security for hiding a data in video, the second goal is to design a computational complexity cryptosystem.

  3. Unitary embedding for data hiding with the SVD

    Science.gov (United States)

    Bergman, Clifford; Davidson, Jennifer

    2005-03-01

    Steganography is the study of data hiding for the purpose of covert communication. A secret message is inserted into a cover file so that the very existence of the message is not apparent. Most current steganography algorithms insert data in the spatial or transform domains; common transforms include the discrete cosine transform, the discrete Fourier transform, and discrete wavelet transform. In this paper, we present a data-hiding algorithm that exploits a decomposition representation of the data instead of a frequency-based transformation of the data. The decomposition transform used is the singular value decomposition (SVD). The SVD of a matrix A is a decomposition A= USV' in which S is a nonnegative diagonal matrix and U and V are orthogonal matrices. We show how to use the orthogonal matrices in the SVD as a vessel in which to embed information. Several challenges were presented in order to accomplish this, and we give effective information-hiding using the SVD can be just as effective as using transform-based techniques. Furthermore, different problems arise when using the SVD than using a transform-based technique. We have applied the SVD to image data, but the technique can be formulated for other data types such as audio and video.

  4. Steganographic Techniques of Data Hiding Using Digital Images (Review Paper

    Directory of Open Access Journals (Sweden)

    Babloo Saha

    2012-01-01

    Full Text Available Steganography is an art that involves communication of secret data in an appropriate carrier, e.g., image, audio, video or TCP/IP header file. Steganography’s goal is to hide the very existence of embedded data so as not to arouse an eavesdropper’s suspicion. For hiding secret data in digital images, large varieties of steganographic techniques are available, some are more complex than others, and all of them have their respective pros and cons. Steganography has various useful applications and the technique employed depends on the requirements of the application to be designed for. For instance. applications may require absolute invisibility of the secret data, larger secret data to be hidden or high degree of robustness of the carrier. This paper intends to give thorough understanding and evolution of different existing digital image steganography techniques of data hiding in spatial, transform and compression domains. It covers and integrates recent research work without going in to much detail of steganalysis, which is the art and science of defeating steganography.Defence Science Journal, 2012, 62(1, pp.11-18, DOI:http://dx.doi.org/10.14429/dsj.62.1436

  5. High Capacity data hiding using LSB Steganography and Encryption

    Directory of Open Access Journals (Sweden)

    Shamim Ahmed Laskar

    2013-01-01

    Full Text Available The network provides a method of communication to distribute information to the masses. With the growthof data communication over computer network, the security of information has become a major issue.Steganography and cryptography are two different data hiding techniques. Steganography hides messagesinside some other digital media. Cryptography, on the other hand obscures the content of the message. Wepropose a high capacity data embedding approach by the combination of Steganography andcryptography. In the process a message is first encrypted using transposition cipher method and then theencrypted message is embedded inside an image using LSB insertion method. The combination of these twomethods will enhance the security of the data embedded. This combinational methodology will satisfy therequirements such as capacity, security and robustness for secure data transmission over an open channel.A comparative analysis is made to demonstrate the effectiveness of the proposed method by computingMean square error (MSE and Peak Signal to Noise Ratio (PSNR. We analyzed the data hiding techniqueusing the image performance parameters like Entropy, Mean and Standard Deviation. The stego imagesare tested by transmitting them and the embedded data are successfully extracted by the receiver. The mainobjective in this paper is to provide resistance against visual and statistical attacks as well as highcapacity.

  6. Data Hiding Techniques Using Prime and Natural Numbers

    CERN Document Server

    Dey, Sandipan; Bandyopadhyay, Bijoy; Sanyal, Sugata

    2010-01-01

    In this paper, a few novel data hiding techniques are proposed. These techniques are improvements over the classical LSB data hiding technique and the Fibonacci LSB data-hiding technique proposed by Battisti et al. \\cite{r1}. The classical LSB technique is the simplest, but using this technique it is possible to embed only in first few bit-planes, since image quality becomes drastically distorted when embedding in higher bit-planes. Battisti et al. \\cite{r1} proposed an improvement over this by using Fibonacci decomposition technique and generating a different set of virtual bit-planes all together, thereby increasing the number of bit-planes. In this paper, first we mathematically model and generalize this particular approach of virtual bit-plane generation. Then we propose two novel embedding techniques, both of which are special-cases of our generalized model. The first embedding scheme is based on decomposition of a number (pixel-value) in sum of prime numbers, while the second one is based on decompositi...

  7. Hiding Data in Images Using New Random Technique

    Directory of Open Access Journals (Sweden)

    Obaida Mohammad Awad Al-Hazaimeh

    2012-07-01

    Full Text Available Steganography is the art of hiding the fact that communication is taking place by hiding information in other information. In the field of Data Communication, Steganography play a major role. The transmission of information via the Internet may expose it to detect and theft. Some solution to be discussed is how to passing information in a manner that the very existence of the message is unknown in order to repel attention of the potential attacker. We focus on the Least Significant Bit (LSB technique which is the most common Steganographic technique is employed in this paper. An improvement to this technique is suggested by randomly inserting the bits of the message in the image to produce more secured system. In this paper, the security goals were enhanced via a proposed cryptosystems to maintain the security on the Cover-image. The proposed solution consists of a simple, but strong to hiding the text data and the human eye would be unable to notice the hidden data in the Stego-image.

  8. An r-Hiding Revocable Group Signature Scheme: Group Signatures with the Property of Hiding the Number of Revoked Users

    Directory of Open Access Journals (Sweden)

    Keita Emura

    2014-01-01

    Full Text Available If there are many displaced workers in a company, then a person who goes for job hunting might not select this company. That is, the number of members who quit is quite negative information. Similarly, in revocable group signature schemes, if one knows (or guesses the number of revoked users (say r, then one may guess the reason behind such circumstances, and it may lead to harmful rumors. However, no previous revocation procedure can achieve hiding r. In this paper, we propose the first revocable group signature scheme, where r is kept hidden, which we call r-hiding revocable group signature. To handle this property, we newly define the security notion called anonymity with respect to the revocation which guarantees the unlinkability of revoked users.

  9. Function S-rough sets and security-authentication of hiding law

    Institute of Scientific and Technical Information of China (English)

    SHI KaiQuan; ZHAO JianLi

    2008-01-01

    Function S-rough sets are defined by R-function equivalence class,which have dynamic characteristic.Function S-rough sets have dynamic characteristic,law characteristic and law-hiding characteristic.Function S-rough sets can generate f-hiding law and f-hiding law.By engrafting,crossing,and penetrating between the information security theory and function S-rough sets,the security hiding and the authentication of f-hiding law and f-hiding law are given respectively in this paper.The fusion and share between function S-rough sets and information secu-rity theory is a new research direction of the application of information law in in-formation system.

  10. Hiding message into DNA sequence through DNA coding and chaotic maps.

    Science.gov (United States)

    Liu, Guoyan; Liu, Hongjun; Kadir, Abdurahman

    2014-09-01

    The paper proposes an improved reversible substitution method to hide data into deoxyribonucleic acid (DNA) sequence, and four measures have been taken to enhance the robustness and enlarge the hiding capacity, such as encode the secret message by DNA coding, encrypt it by pseudo-random sequence, generate the relative hiding locations by piecewise linear chaotic map, and embed the encoded and encrypted message into a randomly selected DNA sequence using the complementary rule. The key space and the hiding capacity are analyzed. Experimental results indicate that the proposed method has a better performance compared with the competing methods with respect to robustness and capacity.

  11. Side-by-Side In(OH3 and In2O3 Nanotubes: Synthesis and Optical Properties

    Directory of Open Access Journals (Sweden)

    Tao Xiaojun

    2009-01-01

    Full Text Available Abstract A simple and mild wet-chemical approach was developed for the synthesis of one-dimensional (1D In(OH3 nanostructures. By calcining the 1D In(OH3 nanocrystals in air at 250 °C, 1D In2O3 nanocrystals with the same morphology were obtained. TEM results show that both 1D In(OH3 and 1D In2O3 are composed of uniform nanotube bundles. SAED and XRD patterns indicate that 1D In(OH3 and 1D In2O3 nanostructures are single crystalline and possess the same bcc crystalline structure as the bulk In(OH3 and In2O3, respectively. TGA/DTA analyses of the precursor In(OH3 and the final product In2O3 confirm the existence of CTAB molecules, and its content is about 6%. The optical absorption band edge of 1D In2O3 exhibits an evident blueshift with respect to that of the commercial In2O3 powders, which is caused by the increasing energy gap resulted from decreasing the grain size. A relatively strong and broad purple-blue emission band centered at 440 nm was observed in the room temperature PL spectrum of 1D In2O3 nanotube bundles, which was mainly attributed to the existence of the oxygen vacancies.

  12. Yield comparison between switchgrass and miscanthus based on multi-year side by side comparison in Europe

    NARCIS (Netherlands)

    Lasorella, M.V.; Monti, A.; Alexopoulou, E.; Riche, A.; Sharma, N.; Cadoux, S.; Diepen, van C.A.; Elbersen, B.S.; Atzema, A.J.; Elbersen, H.W.

    2011-01-01

    Energy crops are expected to provide a significant amount of biomass to achieve the European targets on renewable energy. Here we focus on switchgrass (Panicum virgatum L.) and Miscanthus (Miscanthus x giganteus Greef & Deuter) two rhizomatous perennial grasses which have received particular int

  13. A Comparison of Speech Sound Intervention Delivered by Telepractice and Side-by-Side Service Delivery Models

    Science.gov (United States)

    Grogan-Johnson, Sue; Schmidt, Anna Marie; Schenker, Jason; Alvares, Robin; Rowan, Lynne E.; Taylor, Jacquelyn

    2013-01-01

    Telepractice has the potential to provide greater access to speech-language intervention services for children with communication impairments. Substantiation of this delivery model is necessary for telepractice to become an accepted alternative delivery model. This study investigated the progress made by school-age children with speech sound…

  14. Side-by-Side Comparison of Commonly Used Biomolecules That Differ in Size and Affinity on Tumor Uptake and Internalization.

    Science.gov (United States)

    Leelawattanachai, Jeerapond; Kwon, Keon-Woo; Michael, Praveesuda; Ting, Richard; Kim, Ju-Young; Jin, Moonsoo M

    2015-01-01

    The ability to use a systemically injected agent to image tumor is influenced by tumor characteristics such as permeability and vascularity, and the size, shape, and affinity of the imaging agent. In this study, six different imaging biomolecules, with or without specificity to tumor, were examined for tumor uptake and internalization at the whole body, ex-vivo tissue, and cellular levels: antibodies, antibody fragments (Fab), serum albumin, and streptavidin. The time of peak tumor uptake was dependent solely on the size of molecules, suggesting that molecular size is the major factor that influences tumor uptake by its effect on systemic clearance and diffusion into tumor. Affinity to tumor antigen failed to augment tumor uptake of Fab above non-specific accumulation, which suggests that Fab fragments of typical monoclonal antibodies may fall below an affinity threshold for use as molecular imaging agents. Despite abundant localization into the tumor, albumin and streptavidin were not found on cell surface or inside cells. By comparing biomolecules differing in size and affinity, our study highlights that while pharmacokinetics are a dominant factor in tumor uptake for biomolecules, affinity to tumor antigen is required for tumor binding and internalization.

  15. Thin film PV standing tall side-by-side with multi-crystalline silicon: also in terms of reliability

    Science.gov (United States)

    Dhere, Neelkanth G.; Ward, Allan; Wieting, Robert; Guha, Subhendu; Dhere, Ramesh G.

    2015-09-01

    Triple junction hydrogenated amorphous silicon (a-Si:H) have shown exceptionally good reliability and durability. Cadmium telluride, CdTe PV modules have shown the lowest production cost without subsidies. Copper-indium gallium selenide sulfide (CIGS) and cadmium telluride (CdTe) cells and modules have been showing efficiencies equal or greater than those of multi-crystalline, (mx-Si), PV modules. Early generation CIGS and CdTe PV modules had a different qualification standard 61646 as compared to 61215 for crystalline silicon, (c-Si), PV modules. This, together with small vulnerability in harsh climates, was used to create doubts about their reliability. Recently CdTe and CIGS glass-to-glass modules have passed the rigorous accelerated tests, especially as long as the edge seals are not compromised. Moreover, the cumulative shipment of these modules is more than 12 GW demonstrating the customer confidence in these products. Hence it can be stated that also in terms of the reliability and durability all the thin film PV modules stand tall and compare favorably with mx-Si.

  16. Side-by-Side Comparison of Commonly Used Biomolecules That Differ in Size and Affinity on Tumor Uptake and Internalization.

    Directory of Open Access Journals (Sweden)

    Jeerapond Leelawattanachai

    Full Text Available The ability to use a systemically injected agent to image tumor is influenced by tumor characteristics such as permeability and vascularity, and the size, shape, and affinity of the imaging agent. In this study, six different imaging biomolecules, with or without specificity to tumor, were examined for tumor uptake and internalization at the whole body, ex-vivo tissue, and cellular levels: antibodies, antibody fragments (Fab, serum albumin, and streptavidin. The time of peak tumor uptake was dependent solely on the size of molecules, suggesting that molecular size is the major factor that influences tumor uptake by its effect on systemic clearance and diffusion into tumor. Affinity to tumor antigen failed to augment tumor uptake of Fab above non-specific accumulation, which suggests that Fab fragments of typical monoclonal antibodies may fall below an affinity threshold for use as molecular imaging agents. Despite abundant localization into the tumor, albumin and streptavidin were not found on cell surface or inside cells. By comparing biomolecules differing in size and affinity, our study highlights that while pharmacokinetics are a dominant factor in tumor uptake for biomolecules, affinity to tumor antigen is required for tumor binding and internalization.

  17. Side-by-Side Comparison of LAA Occlusion Performance With the Amplatzer Cardiac Plug and Amplatzer Amulet.

    Science.gov (United States)

    Abualsaud, Ali; Freixa, Xavier; Tzikas, Apostolos; Chan, Jason; Garceau, Patrick; Basmadjian, Arsène; Ibrahim, Réda

    2016-01-01

    The Amplatzer Amulet, a second-generation device for left atrial appendage occlusion (LAAO), has been designed to facilitate the implantation process, improve the closure performance, and reduce the risk of complications. The objective of this study was to compare the outcomes of the Amplatzer Cardiac Plug (ACP) with the Amplatzer Amulet for LAAO, with a special focus on the incidence of residual leaks. This was a prospective, single-center review of consecutive patients undergoing percutaneous LAAO with either ACP or Amulet devices. The first transesophageal echocardiography (TEE) at follow-up (1-3 months) was utilized to assess the occurrence of residual leaks. Between November 2009 and August 2013, a total of 59 patients underwent LAAO with either the ACP device (n = 31) or Amulet device (n = 28). The device was successfully implanted in 58 patients (98.3%). There was no procedural device embolization, stroke, or cardiac tamponade. Follow-up TEE was available in 86% (50 patients; 25 ACP devices and 25 Amulet devices). At follow-up, there was no procedural device embolization, and only 1 patient who received an Amulet device presented with device thrombosis at follow-up. Amulet use was associated with a significant reduction of any leak (minor, moderate, or major) compared with ACP use (48% ACP vs 8% Amulet; P=.01). In this initial series, the Amulet showed similar procedural and short-term clinical outcomes compared with the ACP. The Amulet was, however, associated with a significant reduction of residual leaks at follow-up.

  18. Partitioning and Scheduling DSP Applications with Maximal Memory Access Hiding

    Directory of Open Access Journals (Sweden)

    Sha Edwin Hsing-Mean

    2002-01-01

    Full Text Available This paper presents an iteration space partitioning scheme to reduce the CPU idle time due to the long memory access latency. We take into consideration both the data accesses of intermediate and initial data. An algorithm is proposed to find the largest overlap for initial data to reduce the entire memory traffic. In order to efficiently hide the memory latency, another algorithm is developed to balance the ALU and memory schedules. The experiments on DSP benchmarks show that the algorithms significantly outperform the known existing methods.

  19. A New Images Hiding Scheme Based on Chaotic Sequences

    Institute of Scientific and Technical Information of China (English)

    LIU Nian-sheng; GUO Dong-hui; WU Bo-xi; Parr G

    2005-01-01

    We propose a data hidding technique in a still image. This technique is based on chaotic sequence in the transform domain of covert image. We use different chaotic random sequences multiplied by multiple sensitive images, respectively, to spread the spectrum of sensitive images. Multiple sensitive images are hidden in a covert image as a form of noise. The results of theoretical analysis and computer simulation show the new hiding technique have better properties with high security, imperceptibility and capacity for hidden information in comparison with the conventional scheme such as LSB (Least Significance Bit).

  20. Text Hiding Based on True Color Image Classification

    OpenAIRE

    Shahd Abdul-Rhman Hasso

    2012-01-01

    In this work a new approach was built to apply k-means algorithm on true colored images (24bit images) which are usually treated by researchers as three image (RGB) that are classified to 15 class maximum only. We find the true image as 24 bit and classify it to more than 15 classes. As we know k-means algorithm classify images to many independent classes or features and we could increase the class number therefore we could hide information in the classes or features that have minimum number ...

  1. Approaches to Computer Modeling of Phosphate Hide-Out.

    Science.gov (United States)

    1984-06-28

    phosphate acts as a buffer to keep pH at a value above which acid corrosion occurs . and below which caustic corrosion becomes significant. Difficulties are...ionization of dihydrogen phosphate : HIPO - + + 1PO, K (B-7) H+ + - £Iao 1/1, (B-8) H , PO4 - + O- - H0 4 + H20 K/Kw (0-9) 19 * Such zero heat...OF STANDARDS-1963-A +. .0 0 0 9t~ - 4 NRL Memorandum Report 5361 4 Approaches to Computer Modeling of Phosphate Hide-Out K. A. S. HARDY AND J. C

  2. Data Security by Preprocessing the Text with Secret Hiding

    Directory of Open Access Journals (Sweden)

    Ajit Singh

    2012-06-01

    Full Text Available With the advent of the Internet, an open forum, the massive increase in the data travel across networkmake an issue for secure transmission. Cryptography is the term that involves many encryption method to make data secure. But the transmission of the secure data is an intricate task. Steganography here comes with effect of transmission without revealing the secure data. The research paper provide the mechanism which enhance the security of data by using a crypto+stegano combination to increase the security level without knowing the fact that some secret data is sharing across networks. In the firstphase data is encrypted by manipulating the text using the ASCII codes and some random generated strings for the codes by taking some parameters. Steganography related to cryptography forms the basisfor many data hiding techniques. The data is encrypted using a proposed approach and then hide the message in random N images with the help of perfect hashing scheme which increase the security of the message before sending across the medium. Thus the sending and receiving of message will be safe and secure with an increased confidentiality.

  3. A Study of Various Steganographic Techniques Used for Information Hiding

    Directory of Open Access Journals (Sweden)

    C.P.Sumathi

    2013-12-01

    Full Text Available The art of information hiding has received much att ention in the recent years as security of informati on has become a big concern in this internet era. As shari ng of sensitive information via a common communicat ion channel has become inevitable, Steganography – the art and science of hiding information has gained much attention. We are also surrounded by a world of secret communi cation, where people of all types are transmitting information as innocent as an encrypte d credit card number to an online-store and as insidious as a terrorist plot to hijackers. Stegano graphy derives from the Greek word steganos, meanin g covered or secret, and graphy (writing or drawing [1]. Steganography is a technology where modern da ta compression, information theory, spread spectrum, a nd cryptography technologies are brought together t o satisfy the need for privacy on the Internet. This paper is an attempt to analyse the various tec hniques used in steganography and to identify areas in which thi s technique can be applied, so that the human race can be benefited at large

  4. A Novel Image Data Hiding Scheme with Diamond Encoding

    Directory of Open Access Journals (Sweden)

    Wu Hsien-Chu

    2009-01-01

    Full Text Available A novel data hiding scheme in digital images with the diamond encoding by pixel value adjustment is proposed. The proposed method is the extension of the exploiting modification direction (EMD embedding scheme. First, the process of embedding partitions the cover image into nonoverlapping blocks of two consecutive pixels and transforms the secret messages to a series of -ary digits. For each block, the diamond encoding technique is applied to calculate the diamond characteristic value, and one secret -ary digit is concealed into the diamond characteristic value. The diamond characteristic value is modified to secret digit and it can be obtained by adjusting pixel values in a block. This scheme is designed in such a way that the distortion of each block after diamond encoding is never out of the embedding parameter , and the block capacity is equal to . The diamond encoding provides an easy way to produce a more perceptible result than those yielded by simple least-significant-bit substitution methods. The embedded secret data can be extracted without the original cover image. Experimental results have demonstrated that the proposed method is capable of hiding more secret data while keeping the stego-image quality degradation imperceptible.

  5. Cryptographic Path Hardening: Hiding Vulnerabilities in Software through Cryptography

    CERN Document Server

    Ganesh, Vijay; Rinard, Martin

    2012-01-01

    We propose a novel approach to improving software security called Cryptographic Path Hardening, which is aimed at hiding security vulnerabilities in software from attackers through the use of provably secure and obfuscated cryptographic devices to harden paths in programs. By "harden" we mean that certain error-checking if-conditionals in a given program P are replaced by equivalent" we mean that adversaries cannot use semi-automatic program analysis techniques to reason about the hardened program paths and thus cannot discover as-yet-unknown errors along those paths, except perhaps through black-box dictionary attacks or random testing (which we can never prevent). Other than these unpreventable attack methods, we can make program analysis aimed at error-finding "provably hard" for a resource-bounded attacker, in the same sense that cryptographic schemes are hard to break. Unlike security-through-obscurity, in Cryptographic Path Hardening we use provably-secure crypto devices to hide errors and our mathemati...

  6. Error Concealment using Data Hiding in Wireless Image Transmission

    Directory of Open Access Journals (Sweden)

    A. Akbari

    2016-11-01

    Full Text Available The transmission of image/video over unreliable medium like wireless networks generally results in receiving a damaged image/video. In this paper, a novel image error concealment scheme based on the idea of data hiding and Set Partitioning In Hierarchical Trees (SPIHT coding is investigated. In the encoder side, the coefficients of wavelet decomposed image are partitioned into “perfect trees”. The SPIHT coder is applied to encode each per-fect tree independently and generate an efficiently compressed reference code. This code is then embedded into the coefficients of another perfect tree which is located in a different place, using a robust data hiding scheme based on Quantization Index Modulation (QIM. In the decoder side, if a part of the image is lost, the algorithm extracts the embedded code for reference trees related to this part to reconstruct the lost information. Performance results show that for an error prone transmission, the proposed technique is promising to efficiently conceal the lost areas of the transmitted image.

  7. A secure and robust information hiding technique for covert communication

    Science.gov (United States)

    Parah, S. A.; Sheikh, J. A.; Hafiz, A. M.; Bhat, G. M.

    2015-08-01

    The unprecedented advancement of multimedia and growth of the internet has made it possible to reproduce and distribute digital media easier and faster. This has given birth to information security issues, especially when the information pertains to national security, e-banking transactions, etc. The disguised form of encrypted data makes an adversary suspicious and increases the chance of attack. Information hiding overcomes this inherent problem of cryptographic systems and is emerging as an effective means of securing sensitive data being transmitted over insecure channels. In this paper, a secure and robust information hiding technique referred to as Intermediate Significant Bit Plane Embedding (ISBPE) is presented. The data to be embedded is scrambled and embedding is carried out using the concept of Pseudorandom Address Vector (PAV) and Complementary Address Vector (CAV) to enhance the security of the embedded data. The proposed ISBPE technique is fully immune to Least Significant Bit (LSB) removal/replacement attack. Experimental investigations reveal that the proposed technique is more robust to various image processing attacks like JPEG compression, Additive White Gaussian Noise (AWGN), low pass filtering, etc. compared to conventional LSB techniques. The various advantages offered by ISBPE technique make it a good candidate for covert communication.

  8. 9 CFR 95.24 - Methods for disinfection of hides, skins, and other materials.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Methods for disinfection of hides... ENTRY INTO THE UNITED STATES § 95.24 Methods for disinfection of hides, skins, and other materials... subjected to disinfection by methods found satisfactory and approved from time to time by the Deputy...

  9. A method for removing adobe-type manure from hides using an oxidizing agent

    Science.gov (United States)

    Adobe-type (hardened) manure attached to bovine hair is a major source of meat contamination, hide quality deterioration, and devalued leather products. Therefore, it is important to develop cleaning solutions that can rapidly remove adobe-type manure to improve the quality of hides delivered to tan...

  10. Tactical deception to hide sexual behaviour : macaques use distance, not visibility

    NARCIS (Netherlands)

    Overduin-de Vries, A. M.; Spruijt, B. M.; de Vries, H.; Sterck, E. H. M.

    2015-01-01

    Although tactical deception (TD) may be employed to hide sexual behaviour, there is as yet no firm evidence for it. Hiding may be guided by cognitive mechanisms consistent with either no, low or high level TD, such as exploiting male peripheral positions (no TD), creating distance (TD level 1) or hi

  11. A Review on Reversible Data Hiding Scheme by Image Contrast Enhancement

    Directory of Open Access Journals (Sweden)

    Khushboo Lapa Patwari

    2016-09-01

    Full Text Available In present world demand of high quality images, security of the information on internet is one of the most important issues of research. Data hiding is a method of hiding a useful information by embedding it on another image (cover image to provide security and only the authorize person is able to extract the original information from the embedding data. This paper is a review which describes several different algorithms for Reversible Data Hiding (RDH. Previous literature has shown that histogram modification, histogram equalization (HE and interpolation are the most common methods for data hiding. To improve security these methods are used in encrypted images. This paper is a comprehensive study of all the major reversible data hiding approaches implemented as found in the literature.

  12. Proposed System for data hiding using Cryptography and Steganography Proposed System for data hiding using Cryptography and Steganography

    CERN Document Server

    Sarmah, Dipti Kapoor

    2010-01-01

    Steganography and Cryptography are two popular ways of sending vital information in a secret way. One hides the existence of the message and the other distorts the message itself. There are many cryptography techniques available; among them AES is one of the most powerful techniques. In Steganography we have various techniques in different domains like spatial domain, frequency domain etc. to hide the message. It is very difficult to detect hidden message in frequency domain and for this domain we use various transformations like DCT, FFT and Wavelets etc. In this project we are developing a system where we develop a new technique in which Cryptography and Steganography are used as integrated part along with newly developed enhanced security module. In Cryptography we are using AES algorithm to encrypt a message and a part of the message is hidden in DCT of an image; remaining part of the message is used to generate two secret keys which make this system highly secured. Keyword: Cryptography, Steganography, S...

  13. Mother-young recognition in goitered gazelle during hiding period.

    Science.gov (United States)

    Blank, D A; Yang, W

    2017-09-01

    The mother-young recognition process is crucial for the growth and survival of progeny. In "follower" ungulate species, vocal and visual cues have been found to play a leading role in the mother-young identification process from the first days postpartum, with olfactory cues also important in establishing the initial selective mother-young bond immediately after birth. In "hider" species, however, much less has been documented of mother-young recognition behaviors, especially in their natural habitat. In this paper, we investigated this process in goitered gazelle (Gazella subgutturosa), a typical hider species, in its native environment in Kazakhstan. Over the course of our study period, we investigated the behaviors of 257 females with twins and 158 females with singles through visual observations. We found that within the first month after birth, when females spend only a short time with their young, mothers recognized their fawns using mostly olfactory cues, while vision was used to locate their hiding offspring. Fawns vocalized very rarely, producing only distress calls that did not seem intended for individual identification. Licking of young by their mothers was observed frequently, not only during the first week after birth, when this action was very important for fawn stimulation for a number of physiological functions, but for several weeks after (until one month of age), when licking lost its physiological importance and likely became more of a recognition procedure. Fawns did not recognize their mothers at all, either through vision or vocalizations, since during their first weeks after birth, they responded to any gazelle that approached their hiding area. By a month after birth, when mothers and fawns began to stay together for longer periods of time, their recognition process became more enhanced, and in addition to olfactory cues, the mother and her young began to use more and more visual cues for longer distance identification, as well as

  14. Hiding Secret Information in Movie Clip: A Steganographic Approach

    CERN Document Server

    Sahoo, G

    2011-01-01

    Establishing hidden communication is an important subject of discussion that has gained increasing importance nowadays with the development of the internet. One of the key methods for establishing hidden communication is steganography. Modern day steganography mainly deals with hiding information within files like image, text, html, binary files etc. These file contains small irrelevant information that can be substituted for small secret data. To store a high capacity secret data these carrier files are not very supportive. To overcome the problem of storing the high capacity secret data with the utmost security fence, we have proposed a novel methodology for concealing a voluminous data with high levels of security wall by using movie clip as a carrier file.

  15. An efficient steganography method for hiding patient confidential information.

    Science.gov (United States)

    Al-Dmour, Hayat; Al-Ani, Ahmed; Nguyen, Hung

    2014-01-01

    This paper deals with the important issue of security and confidentiality of patient information when exchanging or storing medical images. Steganography has recently been viewed as an alternative or complement to cryptography, as existing cryptographic systems are not perfect due to their vulnerability to certain types of attack. We propose in this paper a new steganography algorithm for hiding patient confidential information. It utilizes Pixel Value Differencing (PVD) to identify contrast regions in the image and a Hamming code that embeds 3 secret message bits into 4 bits of the cover image. In order to preserve the content of the region of interest (ROI), the embedding is only performed using the Region of Non-Interest (RONI).

  16. Analysis Of Aspects Of Messages Hiding In Text Environments

    Directory of Open Access Journals (Sweden)

    Afanasyeva Olesya

    2015-09-01

    Full Text Available In the work are researched problems, which arise during hiding of messages in text environments, being transmitted by electronic communication channels and the Internet. The analysis of selection of places in text environment (TE, which can be replaced by word from the message is performed. Selection and replacement of words in the text environment is implemented basing on semantic analysis of text fragment, consisting of the inserted word, and its environment in TE. For implementation of such analysis is used concept of semantic parameters of words coordination and semantic value of separate word. Are used well-known methods of determination of values of these parameters. This allows moving from quality level to quantitative level analysis of text fragments semantics during their modification by word substitution. Invisibility of embedded messages is ensured by providing preset values of the semantic cooperation parameter deviations.

  17. Reversible Data Hiding In Encrypted Images Using Improved Encryption Technique

    Directory of Open Access Journals (Sweden)

    Balika J. Chelliah

    2015-11-01

    Full Text Available Recently more and more attention is paid to reversible data hiding (RDH in encrypted images, since it maintains the excellent property that the original cover can be losslessly recovered after embedded data is extracted while protecting the image content‟s confidentiality. All previous methods embed data by reversibly vacating room from the encrypted images, which may be some errors on data extraction and/or image restoration. In this paper we propose a different scheme which attains real reversibility by reserving room before encryption with a traditional RDH algorithm, and then encrypting the data and embedding the data in the encrypted image, which is encrypted using a new proposed algorithm. The proposed method can achieve real reversibility that is data extraction and image recoveries are free of any error.

  18. Reversible Data Hiding In Encrypted Images Using Improved Encryption Technique

    Directory of Open Access Journals (Sweden)

    Mr. Balika J. Chelliah

    2014-03-01

    Full Text Available Recently more and more attention is paid to reversible data hiding (RDH in encrypted images, since it maintains the excellent property that the original cover can be losslessly recovered after embedded data is extracted while protecting the image content‟s confidentiality. All previous methods embed data by reversibly vacating room from the encrypted images, which may be some errors on data extraction and/or image restoration. In this paper we propose a different scheme which attains real reversibility by reserving room before encryption with a traditional RDH algorithm, and then encrypting the data and embedding the data in the encrypted image, which is encrypted using a new proposed algorithm. The proposed method can achieve real reversibility that is data extraction and image recoveries are free of any error.

  19. A Security Enhanced Robust Steganography Algorithm for Data Hiding

    Directory of Open Access Journals (Sweden)

    Siddharth Singh

    2012-05-01

    Full Text Available In this paper, a new robust steganography algorithm based on discrete cosine transform (DCT, Arnold transform and chaotic system is proposed. The chaotic system is used to generate a random sequence to be used for spreading data in the middle frequency band DCT coefficient of the cover image. The security is further enhanced by scrambling the secret data using Arnold Cat map before embedding. The recovery process is blind. A series of experiments is conducted to prove the security and robustness of the proposed algorithm. The experimental results demonstrate that the proposed algorithm achieves higher security and robustness against JPEG compression, addition of noise, low pass filtering and cropping attacks as compared to other existing algorithms for data hiding in the DCT domain.

  20. Statistical Hiding Fuzzy Commitment Scheme for Securing Biometric Templates

    Directory of Open Access Journals (Sweden)

    Alawi A. Al-Saggaf

    2013-04-01

    Full Text Available By considering the security flaws in cryptographic hash functions, any commitment scheme designed straight through hash function usage in general terms is insecure. In this paper, we develop a general fuzzy commitment scheme called an ordinary fuzzy commitment scheme (OFCS, in which many fuzzy commitment schemes with variety complexity assumptions is constructed. The scheme is provably statistical hiding (the advisory gets almost no statistically advantages about the secret message. The efficiency of our scheme offers different security assurance, and the trusted third party is not involved in the exchange of commitment.The characteristic of our scheme makes it useful for biometrics systems. If the biometrics template is compromised, then there is no way to use it directly again even in secure biometrics systems. This paper combines biometrics and OFCS to achieve biometric protection scheme using smart cards with renewability of protected biometrics template property.

  1. Accountable Metadata-Hiding Escrow: A Group Signature Case Study

    Directory of Open Access Journals (Sweden)

    Kohlweiss Markulf

    2015-06-01

    Full Text Available A common approach to demands for lawful access to encrypted data is to allow a trusted third party (TTP to gain access to private data. However, there is no way to verify that this trust is well placed as the TTP may open all messages indiscriminately. Moreover, existing approaches do not scale well when, in addition to the content of the conversation, one wishes to hide one’s identity. Given the importance of metadata this is a major problem. We propose a new approach in which users can retroactively verify cryptographically whether they were wiretapped. As a case study, we propose a new signature scheme that can act as an accountable replacement for group signatures, accountable forward and backward tracing signatures.

  2. Universal Steganalysis of Data Hiding in Grayscale Images

    Institute of Scientific and Technical Information of China (English)

    HUANG Ji-feng; LIN Jia-jun

    2007-01-01

    This paper proposed an universal steganalysis program based on quantification attack which can detect several kinds of data hiding algorithms for grayscale images. In practice, most techniques produce stego images that are perceptually identical to the cover images but exhibit statistical irregularities that distinguish them from cover images. Attacking the suspicious images using the quantization method, we can obtain statistically different from embedded-and-quantization attacked images and from quantization attacked-but-not-embedded sources. We have developed a technique based on one-class SVM for discriminating between cover-images and stego-images. Simulation results show our approach is able to distinguish between cover and stego images with reasonable accuracy.

  3. A Lossless Data Hiding Technique based on AES-DWT

    Directory of Open Access Journals (Sweden)

    Gustavo Fernandaacute;ndez Torres2

    2012-09-01

    Full Text Available In this paper we propose a new data hiding technique. The new technique uses steganography and cryptography on images with a size of 256x256 pixels and an 8-bit grayscale format. There are design restrictions such as a fixed-size cover image, and reconstruction without error of the hidden image. The steganography technique uses a Haar-DWT (Discrete Wavelet Transform with hard thresholding and LSB (Less Significant Bit technique on the cover image. The algorithms used for compressing and ciphering the secret image are lossless JPG and AES, respectively. The proposed technique is used to generate a stego image which provides a double type of security that is robust against attacks. Results are reported for different thresholds levels in terms of PSNR.

  4. Multi-Bit Data Hiding Scheme for Compressing Secret Messages

    Directory of Open Access Journals (Sweden)

    Wen-Chung Kuo

    2015-11-01

    Full Text Available The goal of data hiding techniques usually considers two issues, embedding capacity and image quality. Consequently, in order to achieve high embedding capacity and good image quality, a data hiding scheme combining run-length encoding (RLE with multi-bit embedding is proposed in this paper. This work has three major contributions. First, the embedding capacity is increased 62% because the secret message is compressed before embedding into the cover image. Secondly, the proposed scheme keeps the multi-bit generalized exploiting modification direction (MGEMD characteristics, which are effective to reduce modified pixels in the cover image and to maintain good stego image quality. Finally, the proposed scheme can prevent modern steganalysis methods, such as RS steganalysis and SPAM (subtractive pixel adjacency matrix, and is compared to MiPOD (minimizing the power of the optimal detector scheme. From our simulation results and security discussions, we have the following results: First, there are no perceivable differences between the cover images and stego images from human inspection. For example, the average PSNR of stego images is about 44.61 dB when the secret message (80,000 bits is embedded for test cover images (such as airplane, baboon, Lena of size 512×512. Secondly, Appl. Sci. 2015, 5 1034 on average, 222,087 pixels were not modified after embedding for the cover image. That is to say, 12% less pixels are modified as compared to the MGEMD method. From the performance discussions, the proposed scheme achieves high embedding capacity and good image quality, but also maintains stego image security.

  5. Sensitive plant (Mimosa pudica) hiding time depends on individual and state.

    Science.gov (United States)

    Reed-Guy, Sarah; Gehris, Connor; Shi, Meng; Blumstein, Daniel T

    2017-01-01

    The decisions animals make to adjust their antipredator behavior to rapidly changing conditions have been well studied. Inducible defenses in plants are an antipredator behavior that acts on a longer time scale, but sensitive plants, Mimosa pudica, have a much more rapid antipredator response; they temporarily close their leaves when touched. The time they remain closed is defined as hiding time. We studied hiding time in sensitive plants and found that individual plants differed significantly in their hiding times. We then showed that the effect of individual explained substantial variation in hiding time on a short time scale. Finally, on a longer time scale, individuality persisted but the amount of variation attributed to individual decreased. We hypothesized that variation in plant condition might explain this change. We therefore manipulated sunlight availability and quantified hiding time. When deprived of light for 6 h, sensitive plants significantly shortened their hiding times. But when only half a plant was deprived of light, hiding times on the deprived half and light exposed half were not significantly different. This suggests that overall condition best explains variation in sensitive plant antipredator behavior. Just like in animals, sensitive plant antipredator behavior is condition dependent, and, just like in animals, a substantial amount of the remaining variation is explained by individual differences between plants. Thus, models designed to predict plasticity in animal behavior may be successfully applied to understand behavior in other organisms, including plants.

  6. Sensitive plant (Mimosa pudica hiding time depends on individual and state

    Directory of Open Access Journals (Sweden)

    Sarah Reed-Guy

    2017-07-01

    Full Text Available The decisions animals make to adjust their antipredator behavior to rapidly changing conditions have been well studied. Inducible defenses in plants are an antipredator behavior that acts on a longer time scale, but sensitive plants, Mimosa pudica, have a much more rapid antipredator response; they temporarily close their leaves when touched. The time they remain closed is defined as hiding time. We studied hiding time in sensitive plants and found that individual plants differed significantly in their hiding times. We then showed that the effect of individual explained substantial variation in hiding time on a short time scale. Finally, on a longer time scale, individuality persisted but the amount of variation attributed to individual decreased. We hypothesized that variation in plant condition might explain this change. We therefore manipulated sunlight availability and quantified hiding time. When deprived of light for 6 h, sensitive plants significantly shortened their hiding times. But when only half a plant was deprived of light, hiding times on the deprived half and light exposed half were not significantly different. This suggests that overall condition best explains variation in sensitive plant antipredator behavior. Just like in animals, sensitive plant antipredator behavior is condition dependent, and, just like in animals, a substantial amount of the remaining variation is explained by individual differences between plants. Thus, models designed to predict plasticity in animal behavior may be successfully applied to understand behavior in other organisms, including plants.

  7. STUDY ON AUDIO INFORMATION HIDING METHOD BASED ON MODIFIED PHASE PARTITION

    Institute of Scientific and Technical Information of China (English)

    Tong Ming; Hao Chongyang; Liu Xiaojun; Chen Yanpu

    2005-01-01

    Hiding efficiency of traditional audio information hiding methods is always low since the sentience similarity cannot be guaranteed. A new audio information hiding method is proposed in this letter which can impose the insensitivity with the audio phase for auditory and realize the information hiding through specific algorithm in order to modify local phase within the auditory perception. The algorithm is to introduce the operation of "set 1" and "set 0" for every phase vectors, then the phases must lie on the boundary of a phase area after modified. If it lies on "1" boundary, it comes by set 1 operation. If it lies on "0" boundary, it comes by set 0 operation. The results show that, compared with the legacy method, the proposed method has better auditory similarity, larger information embedding capacity and lower code error rate. As a kind of blind detect method, it fits for application scenario without channel interference.

  8. A Blind High-Capacity Wavelet-Based Steganography Technique for Hiding Images into other Images

    Directory of Open Access Journals (Sweden)

    HAMAD, S.

    2014-05-01

    Full Text Available The flourishing field of Steganography is providing effective techniques to hide data into different types of digital media. In this paper, a novel technique is proposed to hide large amounts of image data into true colored images. The proposed method employs wavelet transforms to decompose images in a way similar to the Human Visual System (HVS for more secure and effective data hiding. The designed model can blindly extract the embedded message without the need to refer to the original cover image. Experimental results showed that the proposed method outperformed all of the existing techniques not only imperceptibility but also in terms of capacity. In fact, the proposed technique showed an outstanding performance on hiding a secret image whose size equals 100% of the cover image while maintaining excellent visual quality of the resultant stego-images.

  9. An evaluation of selected methods for the decontamination of cattle hides prior to skinning.

    Science.gov (United States)

    Small, A; Wells-Burr, B; Buncic, S

    2005-02-01

    The effectiveness of different decontamination treatments in reducing microbial loads on cattle hides was assessed. The 10-s hide treatments were conducted using a wet-and-dry vacuum cleaner filled with one of the liquids (heated to 50 °C) indicated below, followed or not by 10-min drying in the air. Also, the hide was clipped, followed or not by 10-s singeing using a hand-held blowtorch. Before and after each decontamination treatment, the hide was sampled (100 cm(2) areas) by a sponge-swabbing method to compare the total viable counts of bacteria (TVC). The largest bacterial reduction (Psanitizer solution (10% Betane Plus) resulted in significant reductions of 1.80 (Pefficacy of these treatments in the reduction of specific pathogens under commercial conditions.

  10. Motivation to hide emotion and children's understanding of the distinction between real and apparent emotions.

    Science.gov (United States)

    Gosselin, Pierre; Warren, Madeleine; Diotte, Michèle

    2002-12-01

    The authors investigated the extent to which children's understanding of the distinction between real and apparent emotions varied according to the motivation to hide emotions. Children, aged 6-7 and 10-11 years, were read stories designed to elicit either prosocial or self-protective motivated display rules and were asked to predict the facial expressions the protagonists would make to hide felt emotions. Children were found to understand the distinction between real and apparent emotions very well, independently of the type of motivation. Contrary to predictions, boys understood this distinction better than did girls when the motivation to hide positive emotions was prosocial. Children perceived neutralization as the most appropriate strategy to hide felt emotions, followed by masking.

  11. Insight into error hiding: exploration of nursing students' achievement goal orientations.

    Science.gov (United States)

    Dunn, Karee E

    2014-02-01

    An estimated 50% of medication errors go unreported, and error hiding is costly to hospitals and patients. This study explored one issue that may facilitate error hiding. Descriptive statistics were used to examine nursing students' achievement goal orientations in a high-fidelity simulation course. Results indicated that although this sample of nursing students held high mastery goal orientations, they also held moderate levels of performance-approach and performance-avoidance goal orientations. These goal orientations indicate that this sample is at high risk for error hiding, which places the benefits that are typically gleaned from a strong mastery orientation at risk. Understanding variables, such as goal orientation, that can be addressed in nursing education to reduce error hiding is an area of research that needs to be further explored. This article discusses the study results and evidence-based instructional practices for this sample's achievement goal orientation profile.

  12. 16 CFR 1630.61 - Hide carpets and rugs-alternative washing procedure.

    Science.gov (United States)

    2010-01-01

    ... natural “lay” of the hair structure for ten complete strokes. (8) Place test specimen in a circulating... wool or hair attached to the hide with no synthetic fibers and (2) have been treated with a fire...

  13. 16 CFR 1631.61 - Hide carpets and rugs-alternative washing procedure.

    Science.gov (United States)

    2010-01-01

    ... natural “lay” of the hair structure for ten complete strokes. (8) Place test specimen in a circulating... wool or hair attached to the hide with no synthetic fibers and (2) have been treated with a fire...

  14. DNA-based cryptographic methods for data hiding in DNA media.

    Science.gov (United States)

    Marwan, Samiha; Shawish, Ahmed; Nagaty, Khaled

    2016-12-01

    Information security can be achieved using cryptography, steganography or a combination of them, where data is firstly encrypted using any of the available cryptography techniques and then hid into any hiding medium. Recently, the famous genomic DNA has been introduced as a hiding medium, known as DNA steganography, due to its notable ability to hide huge data sets with a high level of randomness and hence security. Despite the numerous cryptography techniques, to our knowledge only the vigenere cipher and the DNA-based playfair cipher have been combined with the DNA steganography, which keeps space for investigation of other techniques and coming up with new improvements. This paper presents a comprehensive analysis between the DNA-based playfair, vigenere, RSA and the AES ciphers, each combined with a DNA hiding technique. The conducted analysis reports the performance diversity of each combined technique in terms of security, speed, hiding capacity in addition to both key size and data size. Moreover, this paper proposes a modification of the current combined DNA-based playfair cipher technique, which makes it not only simple and fast but also provides a significantly higher hiding capacity and security. The conducted extensive experimental studies confirm such outstanding performance in comparison with all the discussed combined techniques. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Hiding effort to gain a competitive advantage: Evidence from China.

    Science.gov (United States)

    Zhao, Li; Heyman, Gail D

    2016-06-06

    Previous studies with Western populations have shown that adolescents' tendency to downplay their academic effort is affected by two kinds of motives: ability-related motives (e.g., to appear competent) and social approval motives (e.g., to be popular). In this research, we test for the presence of additional competition-related motives in China, a culture placing strong emphasis on academic competition. Study 1 (N = 150) showed that, in response to a scenario in which a hard-working high-school junior hid effort from classmates, the most highly endorsed explanation was "to influence others to work less hard to maintain a competitive advantage." Study 2 (N = 174) revealed that competition-related explanations were endorsed relatively more often when the speaker and audience had similar academic rankings. This tendency was most evident when both speaker and audience were top performers, and when this was the case, participants' desire to demonstrate superiority over others was a positive predictor of endorsement of competition-related motives. Study 3 (N = 137) verified that competition-related motives were more strongly endorsed among Chinese participants than U.S. These results suggest that at least in cultures that emphasize academic competition and in contexts where competition is salient, hiding effort is often about attempting to gain strategic advantage. © 2016 International Union of Psychological Science.

  16. Steganographic Approach for Data Hiding using LSB Techniques

    Directory of Open Access Journals (Sweden)

    Baluram Nagaria , Ashish Parikh ,Sandeep Mandliya ,Neeraj shrivastav

    2012-12-01

    Full Text Available Today’s all the multimedia work done via internet so it’s an urgent need to protect the data from malicious attacks. This lead to the research in the area of Digital watermarking and cryptography which intends to protect the copyright information of the intellectuals. In this paper a DCT based steganography scheme is proposed which provides higher resistance to image processing attacks such as JPEG compression, noise, rotation, translation etc Steganography has been implemented In MATLAB7.6 using basic image processing techniques. Steganography is the technique of hiding confidential information within any media. Steganography is often confused with cryptography because the two are similar in the way that they both are used to protect confidential information But we have design a simulator in which we have transmit our data via mail or LAN. For securing the data, this will be password protected. For design this simulator we have encrypted our data and after that without password we will not decrypted the data. Our all conclusion is that we will secure our information. The difference between the two is in the appearance in the processed output; the output of Steganography operation is not apparently visible but in cryptography the output is scrambled so that it can draw attention. In this paper, we have tried to elucidate the different approaches towards implementation of Steganography using ‘multimedia’ file (text, static image, audio and video and Network IP datagram as cover.

  17. Experimental Test of Quantum No-Hiding Theorem

    CERN Document Server

    Samal, Jharana Rani; Kumar, Anil

    2010-01-01

    Linearity and unitarity are two fundamental tenets of quantum theory. Any consequence that follows from these must be respected in the quantum world. The no-cloning theorem and the no-deleting theorem are the consequences of the linearity and the unitarity. Together with the stronger no-cloning theorem they provide permanence to quantum information, thus, suggesting that in the quantum world information can neither be created nor be destroyed. In this sense quantum information is robust, but at the same time it is also fragile because any interaction with the environment may lead to loss of information. Recently, another fundamental theorem was proved, namely, the no-hiding theorem that addresses precisely the issue of information loss. It says that if any physical process leads to bleaching of quantum information from the original system, then it must reside in the rest of the universe with no information being hidden in the correlation between these two subsystems. This has applications in quantum teleporta...

  18. Confidential Data Hiding Using Wavlet Based Ecg Stegnography

    Directory of Open Access Journals (Sweden)

    Malashree K S

    2014-05-01

    Full Text Available With the growing number of aging population and a significant portion of that suffering from cardiac diseases, it is conceivable that remote ECG patient monitoring systems are expected to be widely used as Point-of-Care (PoC applications in hospitals around the world. Therefore, huge amount of ECG signal collected by Body Sensor Networks (BSNs from remote patients at homes will be transmitted along with other physiological readings such as blood pressure, temperature, glucose level etc. and diagnosed by those remote patient monitoring systems. It is utterly important that patient confidentiality is protected while data is being transmitted over the public network as well as when they are stored in hospital servers used by remote monitoring systems. In this project, a wavelet based steganography technique has been introduced which combines encryption and scrambling technique to protect patient confidential data. The proposed method allows ECG signal to hide its corresponding patient confidential data and other physiological information thus guaranteeing the integration between ECG and the rest.

  19. Imaging of subducted lithosphere beneath South America

    NARCIS (Netherlands)

    Engdahl, E.R.; Hilst, R.D. van der; Berrocal, J.

    1995-01-01

    Tomographic images are produced for the deep structure of the Andean subduction zone beneath western South America. The data used in the imaging are the delay times of P, pP and pwP phases from relocated teleseismic earthquakes in the region. Regionally, structural features larger than about 150 km

  20. Information Hiding and Countermeasures%信息隐藏技术及其攻击方法

    Institute of Scientific and Technical Information of China (English)

    吴树峰; 黄刘生; 卢继军; 陈国良

    2003-01-01

    Information Hiding Technology has a long history. With the development of Digital Technology,it has become a newly evolved discipline and a hot research area. Since the first Information Hiding Workshop held in 1996 ,thetechnology has been widely applied to areas such as multimedia ,signal processing and protection of software Intellectual Property,but the research work in secure communication is relatively fewer. Based on success of developing asteganography tool for communication,this article summarizes the current progress in the research of InformationHiding Technology systematically, and analyzes possible countermeasures against various Information Hiding techniques.

  1. The Costs of Hiding and Faking Emotions: The Case of Extraverts and Introverts.

    Science.gov (United States)

    Seger-Guttmann, Tali; Medler-Liraz, Hana

    2016-01-01

    The present study examined the moderation effects of extraversion on the relationships between hiding and faking emotions, perceived satisfaction from intimate relationships, and reported physical health concerns. Four hundred and four Israeli participants, who were all involved in intimate relationships at the time of the study, responded to the Extraversion scale from the Big-Five Inventory, the DEELS to measure hiding and faking emotions, the SELF to assess physical health concerns, and the short version of the ENRICH to evaluate perceived satisfaction with intimate relationships. The mean age was 32.3 years (SD = 8.2); and the average length of time as a couple was 7.8 years (SD = 8.2). Of the participants, 198 were married (48.5%). The findings indicate that the effect of hiding negative emotions was stronger for perceived satisfaction with intimate relationships and physical health concerns than that for faking positive emotions. Extraverts who showed a higher frequency of hiding their negative emotions were significantly less satisfied with their relationships than introverts and they also tended to report more concerns with their physical health. These results were not found when extraverts reported a high frequency of faking positive emotions. These results are discussed in the context of the trait-behavior-concordance model and stress the importance of distinguishing faking from hiding.

  2. Association Rule Hiding Techniques for Privacy Preserving Data Mining: A Study

    Directory of Open Access Journals (Sweden)

    Gayathiri P

    2015-12-01

    Full Text Available Association rule mining is an efficient data mining technique that recognizes the frequent items and associative rule based on a market basket data analysis for large set of transactional databases. The probability of most frequent data item occurrence of the transactional data items are calculated to present the associative rule that represents the habits of buying products of the customers in demand. Identifying associative rules of a transactional database in data mining may expose the confidentiality and privacy of an organization and individual. Privacy Preserving Data Mining (PPDM is a solution for privacy threats in data mining. This issue is solved using Association Rule Hiding (ARH techniques in Privacy Preserving Data Mining (PPDM. This research work on Association Rule Hiding technique in data mining performs the generation of sensitive association rules by the way of hiding based on the transactional data items. The property of hiding rules not the data makes the sensitive rule hiding process is a minimal side effects and higher data utility technique.

  3. The Ocean Boundary Layer beneath Hurricane Frances

    Science.gov (United States)

    Dasaro, E. A.; Sanford, T. B.; Terrill, E.; Price, J.

    2006-12-01

    The upper ocean beneath the peak winds of Hurricane Frances (57 m/s) was measured using several varieties of air-deployed floats as part of CBLAST. A multilayer structure was observed as the boundary layer deepened from 20m to 120m in about 12 hours. Bubbles generated by breaking waves create a 10m thick surface layer with a density anomaly, due to the bubbles, of about 1 kg/m3. This acts to lubricate the near surface layer. A turbulent boundary layer extends beneath this to about 40 m depth. This is characterized by large turbulent eddies spanning the boundary layer. A stratified boundary layer grows beneath this reaching 120m depth. This is characterized by a gradient Richardson number of 1/4, which is maintained by strong inertial currents generated by the hurricane, and smaller turbulent eddies driven by the shear instead of the wind and waves. There is little evidence of mixing beneath this layer. Heat budgets reveal the boundary layer to be nearly one dimensional through much of the deepening, with horizontal and vertical heat advection becoming important only after the storm had passed. Turbulent kinetic energy measurements support the idea of reduced surface drag at high wind speeds. The PWP model correctly predicts the degree of mixed layer deepening if the surface drag is reduced at high wind speed. Overall, the greatest uncertainty in understanding the ocean boundary layer at these extreme wind speeds is a characterization of the near- surface processes which govern the air-sea fluxes and surface wave properties.

  4. Managing Communication Latency-Hiding at Runtime for Parallel Programming Languages and Libraries

    CERN Document Server

    Kristensen, Mads Ruben Burgdorff

    2012-01-01

    This work introduces a runtime model for managing communication with support for latency-hiding. The model enables non-computer science researchers to exploit communication latency-hiding techniques seamlessly. For compiled languages, it is often possible to create efficient schedules for communication, but this is not the case for interpreted languages. By maintaining data dependencies between scheduled operations, it is possible to aggressively initiate communication and lazily evaluate tasks to allow maximal time for the communication to finish before entering a wait state. We implement a heuristic of this model in DistNumPy, an auto-parallelizing version of numerical Python that allows sequential NumPy programs to run on distributed memory architectures. Furthermore, we present performance comparisons for eight benchmarks with and without automatic latency-hiding. The results shows that our model reduces the time spent on waiting for communication as much as 27 times, from a maximum of 54% to only 2% of t...

  5. Hiding Sensitive Association Rules without Altering the Support of Sensitive Item(s)

    CERN Document Server

    Jain, Dhyanendra

    2012-01-01

    Association rule mining is an important data-mining technique that finds interesting association among a large set of data items. Since it may disclose patterns and various kinds of sensitive knowledge that are difficult to find otherwise, it may pose a threat to the privacy of discovered confidential information. Such information is to be protected against unauthorized access. Many strategies had been proposed to hide the information. Some use distributed databases over several sites, data perturbation, clustering, and data distortion techniques. Hiding sensitive rules problem, and still not sufficiently investigated, is the requirement to balance the confidentiality of the disclosed data with the legitimate needs of the user. The proposed approach uses the data distortion technique where the position of the sensitive items is altered but its support is never changed. The size of the database remains the same. It uses the idea of representative rules to prune the rules first and then hides the sensitive rule...

  6. The study results steganography hiding messages in image files as vehicle security software

    Directory of Open Access Journals (Sweden)

    D. O. Navrotskyi

    2012-11-01

    Full Text Available Synergetics of steganographic and cryptographic encryption algorithms, which provide a solid security foundation, is presented in this paper. Hiding messages systems in spatial and frequency domain image are compared and studied by the author. The following questions: Compression scheme JPEG , JPEG – transformation structure, Practical recommendations for hiding data to image files, The method of least significant bits (spatial domain and the DCT coefficients values relative replacement method (frequency domain, Packing and unpacking the hidden message, Visual distortion image changing system parameters are considered.

  7. A statistical hiding algorithm based on self-similar network traffic

    Institute of Scientific and Technical Information of China (English)

    SHA Xue-jun; XU Yu-bin; QIANG Wei

    2008-01-01

    Although the encryption of network packets significantly increases privacy, the density of the traffic can still provide useful information to the observer, and maybe results in the breach of confidentiality. In this paper, we address issues related to hiding information in self-similar network, which is proved to be similar with modem communication network. And a statistical hiding algorithm is proposed for traffic padding. The figures and the comparison of Hurst Parameters before and after traffic padding, show the effective performance of the algorithm.

  8. Reliable Transmission of Audio Streams in Lossy Channels Using Application Level Data Hiding

    Directory of Open Access Journals (Sweden)

    Parag Agarwal

    2008-12-01

    Full Text Available The paper improves the reliability of audio streams in a lossy channel. The mechanism groups audio data samples into source and carrier sets. The carrier set carry the information about the source set which is encoded using data hiding methodology - quantization index modulation. At the receiver side, a missing source data sample can be reconstructed using the carrier set and the remaining source set. Based on reliability constraints a hybrid design combining interleaving and data hiding is presented. Experiments show an improved reliability as compared to forward error correction and interleaving.

  9. INDICATOR AND PATHOGENIC MICROORGANISMS CONTAMINATION OF HIDE OF CATTLE PRESENTED TO FOR SLAUGHTER AND CONTAMINATION OF THE RESULTANT CARCASSES

    Directory of Open Access Journals (Sweden)

    G. Liuzzo

    2011-01-01

    Full Text Available Foodborne pathogens including Escherichia coli O157:H7, Salmonella spp. and Campylobacter spp., can enter the meat chain at multiple points. Animals with excessively dirty hides will represent a risk of cross-contaminations during transport, in the slaughtered house environment and during dressing procedures. The aim of this work was to investigate the relationship among hygiene indicator microorganisms (Enterobacteriaceae and Escherichia coli count, in hide and carcass of cattle presented for slaughter, and different hide cleanliness level in two abattoir (R and F and estimate the prevalence of pathogens Escherichia coli O157:H7, Salmonella spp and Campylobacter spp. in hide and carcass of dirty animals. The results showed that hide Escherichia coli and Enterobacteriaceae count were significantly higher in dirty animals than in clean animals (P<0,05, but carcass contamination were significantly higher in dirty animals than in clean animals only in R abattoir. Escherichia coli O 157:H7 was detected in 19 samples of hide (40,4%, and 2 samples of carcass. Campylobacter jejuni was isolated in 13 samples of hide (25,5% and one sample of carcass. Salmonella spp. were not found in all the samples of hide and carcass.

  10. Analysis of groundwater flow beneath ice sheets

    Energy Technology Data Exchange (ETDEWEB)

    Boulton, G. S.; Zatsepin, S.; Maillot, B. [Univ. of Edinburgh (United Kingdom). Dept. of Geology and Geophysics

    2001-03-01

    The large-scale pattern of subglacial groundwater flow beneath European ice sheets was analysed in a previous report. It was based on a two-dimensional flowline model. In this report, the analysis is extended to three dimensions by exploring the interactions between groundwater and tunnel flow. A theory is developed which suggests that the large-scale geometry of the hydraulic system beneath an ice sheet is a coupled, self-organising system. In this system the pressure distribution along tunnels is a function of discharge derived from basal meltwater delivered to tunnels by groundwater flow, and the pressure along tunnels itself sets the base pressure which determines the geometry of catchments and flow towards the tunnel. The large-scale geometry of tunnel distribution is a product of the pattern of basal meltwater production and the transmissive properties of the bed. The tunnel discharge from the ice margin of the glacier, its seasonal fluctuation and the sedimentary characteristics of eskers are largely determined by the discharge of surface meltwater which penetrates to the bed in the terminal zone. The theory explains many of the characteristics of esker systems and can account for tunnel valleys. It is concluded that the large-scale hydraulic regime beneath ice sheets is largely a consequence of groundwater/tunnel flow interactions and that it is essential similar to non-glacial hydraulic regimes. Experimental data from an Icelandic glacier, which demonstrates measured relationships between subglacial tunnel flow and groundwater flow during the transition from summer to winter seasons for a modern glacier, and which support the general conclusions of the theory is summarised in an appendix.

  11. Microbial life beneath a high arctic glacier.

    Science.gov (United States)

    Skidmore, M L; Foght, J M; Sharp, M J

    2000-08-01

    The debris-rich basal ice layers of a high Arctic glacier were shown to contain metabolically diverse microbes that could be cultured oligotrophically at low temperatures (0.3 to 4 degrees C). These organisms included aerobic chemoheterotrophs and anaerobic nitrate reducers, sulfate reducers, and methanogens. Colonies purified from subglacial samples at 4 degrees C appeared to be predominantly psychrophilic. Aerobic chemoheterotrophs were metabolically active in unfrozen basal sediments when they were cultured at 0.3 degrees C in the dark (to simulate nearly in situ conditions), producing (14)CO(2) from radiolabeled sodium acetate with minimal organic amendment (> or =38 microM C). In contrast, no activity was observed when samples were cultured at subfreezing temperatures (glacier provides a viable habitat for life and that microbes may be widespread where the basal ice is temperate and water is present at the base of the glacier and where organic carbon from glacially overridden soils is present. Our observations raise the possibility that in situ microbial production of CO(2) and CH(4) beneath ice masses (e.g., the Northern Hemisphere ice sheets) is an important factor in carbon cycling during glacial periods. Moreover, this terrestrial environment may provide a model for viable habitats for life on Mars, since similar conditions may exist or may have existed in the basal sediments beneath the Martian north polar ice cap.

  12. Hiding an Inconvenient Truth : Lies and Vagueness (Revision of DP 2008-107)

    NARCIS (Netherlands)

    Serra Garcia, M.; van Damme, E.E.C.; Potters, J.J.M.

    2010-01-01

    When truth conflicts with efficiency, can verbal communication destroy efficiency? Or are lies or vagueness used to hide inconvenient truths? We consider a sequential 2-player public good game in which the leader has private information about the value of the public good. This value can be low, high

  13. Efficiently Hiding Sensitive Itemsets with Transaction Deletion Based on Genetic Algorithms

    Directory of Open Access Journals (Sweden)

    Chun-Wei Lin

    2014-01-01

    Full Text Available Data mining is used to mine meaningful and useful information or knowledge from a very large database. Some secure or private information can be discovered by data mining techniques, thus resulting in an inherent risk of threats to privacy. Privacy-preserving data mining (PPDM has thus arisen in recent years to sanitize the original database for hiding sensitive information, which can be concerned as an NP-hard problem in sanitization process. In this paper, a compact prelarge GA-based (cpGA2DT algorithm to delete transactions for hiding sensitive itemsets is thus proposed. It solves the limitations of the evolutionary process by adopting both the compact GA-based (cGA mechanism and the prelarge concept. A flexible fitness function with three adjustable weights is thus designed to find the appropriate transactions to be deleted in order to hide sensitive itemsets with minimal side effects of hiding failure, missing cost, and artificial cost. Experiments are conducted to show the performance of the proposed cpGA2DT algorithm compared to the simple GA-based (sGA2DT algorithm and the greedy approach in terms of execution time and three side effects.

  14. Steganographic optical image encryption system based on reversible data hiding and double random phase encoding

    Science.gov (United States)

    Chuang, Cheng-Hung; Chen, Yen-Lin

    2013-02-01

    This study presents a steganographic optical image encryption system based on reversible data hiding and double random phase encoding (DRPE) techniques. Conventional optical image encryption systems can securely transmit valuable images using an encryption method for possible application in optical transmission systems. The steganographic optical image encryption system based on the DRPE technique has been investigated to hide secret data in encrypted images. However, the DRPE techniques vulnerable to attacks and many of the data hiding methods in the DRPE system can distort the decrypted images. The proposed system, based on reversible data hiding, uses a JBIG2 compression scheme to achieve lossless decrypted image quality and perform a prior encryption process. Thus, the DRPE technique enables a more secured optical encryption process. The proposed method extracts and compresses the bit planes of the original image using the lossless JBIG2 technique. The secret data are embedded in the remaining storage space. The RSA algorithm can cipher the compressed binary bits and secret data for advanced security. Experimental results show that the proposed system achieves a high data embedding capacity and lossless reconstruction of the original images.

  15. Random Traversing Based Reversible Data Hiding Technique Using PE and LSB

    Directory of Open Access Journals (Sweden)

    Rhythm Katira

    2013-04-01

    Full Text Available The rise in the use of internet, secure transmission of the data has become an utmost priority. Steganography makes the data invisible by hiding it in the multimedia such as image, audio or video file and thereby covering for its existence. In this project we use prediction error (PE technique steganography and Least Significant Bit (LSB substitution method to hide data in the image. As we do PE expansion method it can lead to expansion of pixels like it can lead to pixel value above 255. In order to solve this problem, we restricted the pixel values between 15 and 240.The PSNR was high at low threshold values. The hiding capacity increased with increase in threshold with a reasonable decrease in PSNR. There was 2dB difference then other methods because of high data hiding capacity. Also we have used knight’s tour for increasing the security of data hidden. In comparison to other methodology, this methodology proves to be better and more effective.

  16. A NOVEL APPROACH OF SECURE COMMUNICATION BASED ON THE TECHNIQUE OF SPEECH INFORMATION HIDING

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The proposed secure communication approach adopts the proposed algorithm of Analysis-BySynthesis (ABS) speech information hiding to establish a Secret Speech Subliminal Channel (SSSC) for speech secure communication over PSTN (Public Switched Telephone Network), and employs the algorithm of ABS speech information extracting to recovery the secret information. This approach is more reliable, covert and securable than traditional and chaotic secure communication.

  17. Effect of hiding places, straw and territory on agression in group-housed rabbit does

    NARCIS (Netherlands)

    Rommers, J.M.; Reuvekamp, B.F.J.; Gunnink, H.; Jong, de I.C.

    2014-01-01

    Group-housing of rabbit does may be preferred from welfare point of view. However, group-housing causes agonistic behaviour which may cause severe injuries. Severe injuries may be prevented by offering hiding places for attacked does. Providing enrichment (straw) may reduce agonistic behaviour by at

  18. Imaging magma plumbing beneath Askja volcano, Iceland

    Science.gov (United States)

    Greenfield, Tim; White, Robert S.

    2015-04-01

    Volcanoes during repose periods are not commonly monitored by dense instrumentation networks and so activity during periods of unrest is difficult to put in context. We have operated a dense seismic network of 3-component, broadband instruments around Askja, a large central volcano in the Northern Volcanic Zone, Iceland, since 2006. Askja last erupted in 1961, with a relatively small basaltic lava flow. Since 1975 the central caldera has been subsiding and there has been no indication of volcanic activity. Despite this, Askja has been one of the more seismically active volcanoes in Iceland. The majority of these events are due to an extensive geothermal area within the caldera and tectonically induced earthquakes to the northeast which are not related to the magma plumbing system. More intriguing are the less numerous deeper earthquakes at 12-24km depth, situated in three distinct areas within the volcanic system. These earthquakes often show a frequency content which is lower than the shallower activity, but they still show strong P and S wave arrivals indicative of brittle failure, despite their location being well below the brittle-ductile boundary, which, in Askja is ~7km bsl. These earthquakes indicate the presence of melt moving or degassing at depth while the volcano is not inflating, as only high strain rates or increased pore fluid pressures would cause brittle fracture in what is normally an aseismic region in the ductile zone. The lower frequency content must be the result of a slower source time function as earthquakes which are both high frequency and low frequency come from the same cluster, thereby discounting a highly attenuating lower crust. To image the plumbing system beneath Askja, local and regional earthquakes have been used as sources to solve for the velocity structure beneath the volcano. Travel-time tables were created using a finite difference technique and the residuals were used to solve simultaneously for both the earthquake locations

  19. Identification of Contaminations Hiding Beneath the α- and β-Subunits of Partially Purified Nitrogenase MoFe Protein on the Sodium Dodecyl Sulfate Gel

    Institute of Scientific and Technical Information of China (English)

    Hui-Na ZHOU; Ying ZHAO; Shao-Min BIAN; Jian-Feng ZHAO; Fei REN; Huang-Ping WANG; Ju-Fu HUANG

    2005-01-01

    To identify the unknown proteins that would contaminate the α- and β-subunits of nitrogenase MoFe protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the partially purified MoFe protein (Av 1) preparation was obtained from Azotobacter vinelandii Lipmann OP by chromatography on DEAE-cellulose (DE52) and Sephacryl S-200 columns and analyzed by PAGE and matrixassisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. The Av 1 preparation was shown to have two main bands at the position of the α- and β-subunits of crystalline Avl on the SDS gel. However, on the anoxic native PAGE, in addition to the Ay 1 band, the preparation was shown to have three other main bands that migrated slower than Avl. Of these three main bands, the protein with the fastest migration was identified as bacterioferritin elsewhere. The proteins on the other two bands, termed Upper and Middle, were suggested to be two different homopolymers with the same apparent subunit electrophoretic mobilities as the α- and β-subunits of Avl, respectively. By analysis of MALDI-TOF mass spectrometry, the Upper was identified as GroEL, which belongs to the heat shock protein 60 family, and the Middle was identified as glucose-6-phosphate isomerase (PGI). In our preparation, anoxic native electrophoresis indicated that GroEL was composed of 14 identical subunits and that PGI was composed of 10 identical subunits. This is the first report of PGI, with so many subunits. The contaminating proteins in the Av 1 preparation, mainly GroEL and PGI, could be totally or partially removed from Av1 if the shoulders and center of the elution peak were collected separately from the Sephacryl S-200 column and the center fraction was purified further by Q-Sepharose developed with an NaCl concentration gradient. Thus, Avl with more than 90% purity was obtained. Obviously, this modified method is useful for the purification of mutant MoFe proteins with a high purity.

  20. Active convection beneath ridges: a new spin

    Science.gov (United States)

    Katz, R. F.

    2009-12-01

    The role of buoyancy-driven, "active" upwelling beneath mid-ocean ridges has been long debated [1,2,3], with the naysayers holding sway in recent years. Recent work on tomographic imaging of the sub-ridge mantle has revealed patterns in velocity variation that seem inconsistent with what we expect of passive upwelling and melting [4]. The irregular distribution, asymmetry, and off-axis locations of slow regions in tomographic results are suggestive of time-dependent convective flow. Using 2D numerical simulations of internally consistent mantle and magmatic flow plus melting/freezing [5,6], I investigate the parametric subspace in which active convection is expected to occur. For low mantle viscosities, interesting symmetry-breaking behavior is predicted. References: [1] Rabinowicz, et al., EPSL, 1984; [2] Buck & Su, GRL, 1989; [3] Scott & Stevenson, JGR, 1989; [4] Toomey et al., Nature, 2007; [5] McKenzie, J.Pet., 1984; [6] Katz, J.Pet., 2008;

  1. Research on the methods of optical image hiding based on double random phase encoding and digital holography

    Science.gov (United States)

    Xu, Hongsheng; Sang, Nong

    2011-12-01

    Optical information hiding system has many features such as high processing speed, high parallel, high encryption dimension and high speed of optical transformation and related operations, more advantages than digital method in some way. But it has not adequate security, and enough combination with techniques of digital image processing. So on basis of analyzing existing image hiding and analyzing techniques, we give out the idea. We should adopt idea of virtual optics on the way of all-digital simulation to do research of optical image hiding and analyzing methods based on optical image processing technique especially technique of double random phase encoding and digital holography.

  2. The potency of plant extracts as antimicrobials for the skin or hide preservation

    Science.gov (United States)

    Suparno, Ono; Afifah, Amalia; Panandita, Tania; Marimin, Purnawati, Rini

    2017-03-01

    Preservation of skin or hide uses antimicrobial that will be disposed in wastewater in the skin or hide processing resulting in the environmental pollution. Extracts of some types of plants contain some antimicrobial substances which are potential to be used as biocides for the preservation of skin or hide and are more environmentally friendly. The objectives of this study were to determine the phytochemical contents of moringa, cucumber tree or wuluh starfruit, cherry, and white leadtree or lamtoro leaves and to analyse the antibacterial activities of the plant extracts against microorganisms that cause spoilage of skin or hide. Phytochemical constituents of the dried plant leaves were extracted by 70% ethanol. The resulting extracts were analysed their phytochemical contents and antimicrobial activities against gram negative and gram positive bacteria (inhibition zone test) by well diffusion method, the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC). Phytochemical test showed that the four leaf extracts contained alkaloids, saponins, tannins, flavonoids, steroids, and glycosides. The inhibition zones of the extracts against Escherichia coli were 5 mm for moringa leaf, 6 mm for cucumber tree leaf, 12 mm for cherry leaf, and 17 mm for white leadtree leaf. Inhibition zone of the extracts against Staphylococcus aureus were 2.5 mm for moringa leaf, 7 mm for cucumber tree leaf, 7.3 mm for cherry leaf, and 13 mm for white leadtree leaf. Inhibition zones of the extracts against Bacillus subtilis were 8 mm for moringa leaf, 9 mm for cucumber tree starfruit leaf, 14 mm for cherry leaf, and 15 mm for white leadtree leaf. The best MIC and MBC tests were demonstrated by white leadtree leaf extract against E. coli found at concentration of 1500 µg/ml, against S. aureus at concentration of 3000 µg/ml, and against B. subtilis at concentration of 3000 µg/ml. The ethanol extract of white leadtree leaf had the best antibacterial activity

  3. Comparison of methods for the enumeration of enterohemorrhagic Escherichia coli from veal hides and carcasses

    Directory of Open Access Journals (Sweden)

    Brandon E Luedtke

    2015-09-01

    Full Text Available The increased association of enterohemorrhagic Escherichia coli (EHEC with veal calves has led the United States Department of Agriculture Food Safety and Inspection Service to report results of veal meat contaminated with the Top 7 serogroups separately from beef cattle. However, detection methods that can also provide concentration for determining the prevalence and abundance of EHEC associated with veal are lacking. Here we compared the ability of qPCR and a molecular based most probable number assay (MPN to detect and enumerate EHEC from veal hides at the abattoir and the resulting pre-intervention carcasses. In addition, digital PCR (dPCR was used to analyze select samples. The qPCR assay was able to enumerate total EHEC in 32% of the hide samples with a range of approximately 34 to 91,412 CFUs/100 cm2 (95% CI 4-113,460 CFUs/100 cm2. Using the MPN assay, total EHEC was enumerable in 48% of the hide samples and ranged from approximately 1 to greater than 17,022 CFUs/100 cm2 (95% CI 0.4-72,000 CFUs/100 cm2. The carcass samples had lower amounts of EHEC with a range of approximately 4 to 275 CFUs/100 cm2 (95% CI 3-953 CFUs/100 cm2 from 17% of samples with an enumerable amount of EHEC by qPCR. For the MPN assay, the carcass samples ranged from 0.1 to 1 CFUs/100 cm2 (95% CI 0.02-4 CFUs/100 cm2 from 29% of the samples. The correlation coefficient between the qPCR and MPN enumeration methods indicated a moderate relation (R2=0.39 for the hide samples while the carcass samples had no relation (R2=0.002, which was likely due to most samples having an amount of total EHEC below the reliable limit of quantification for qPCR. Interestingly, after enrichment, 81% of the hide samples and 94% of the carcass samples had a detectable amount of total EHEC by qPCR. From our analysis, the MPN assay provided a higher percentage of enumerable hide and carcass samples, however determining an appropriate dilution range and the limited throughput offer additional

  4. Subduction or delamination beneath the Apennines? Evidence from regional tomography

    NARCIS (Netherlands)

    Koulakov, I.; Jakovlev, A.; Zabelina, I.; Roure, F.; Cloetingh, S.; El Khrepy, S.; Al-Arifi, N.

    2015-01-01

    In this study we present a new regional tomography model of the upper mantle beneath Italy and the surrounding area derived from the inversion of travel times of P and S waves from the updated International Seismological Centre (ISC) catalogue. Beneath Italy, we identify a high-velocity anomaly whic

  5. Recursive histogram modification: establishing equivalency between reversible data hiding and lossless data compression.

    Science.gov (United States)

    Zhang, Weiming; Hu, Xiaocheng; Li, Xiaolong; Yu, Nenghai

    2013-07-01

    State-of-the-art schemes for reversible data hiding (RDH) usually consist of two steps: first construct a host sequence with a sharp histogram via prediction errors, and then embed messages by modifying the histogram with methods, such as difference expansion and histogram shift. In this paper, we focus on the second stage, and propose a histogram modification method for RDH, which embeds the message by recursively utilizing the decompression and compression processes of an entropy coder. We prove that, for independent identically distributed (i.i.d.) gray-scale host signals, the proposed method asymptotically approaches the rate-distortion bound of RDH as long as perfect compression can be realized, i.e., the entropy coder can approach entropy. Therefore, this method establishes the equivalency between reversible data hiding and lossless data compression. Experiments show that this coding method can be used to improve the performance of previous RDH schemes and the improvements are more significant for larger images.

  6. Data Hiding by LSB Substitution Using Genetic Optimal Key-Permutation

    Directory of Open Access Journals (Sweden)

    Marghny Mohamed

    2011-01-01

    Full Text Available The least significant bit (LSB embedding method is one of the most commonly used techniques; it targets the LSB'sof the host image to hide the data. This paper deals with three main steganography challenges (i.e. capacity, imperceptibility,and security. This is achieved by hybrid data hiding scheme incorporates LSB technique with a key-permutation method. Thepaper also proposes an optimal key permutation method using genetic algorithms for best key selection. Both normal andoptimized methods are tested with standard images, varying both data size as well as key space. Final experimental resultsshow decrement in computation time when increasing number of keys, at the same time system security improves.

  7. Parallel steganography framework for hiding a color image inside stereo images

    Science.gov (United States)

    Munoz-Ramirez, David O.; Ponomaryov, Volodymyr I.; Reyes-Reyes, Rogelio; Cruz-Ramos, Clara

    2017-05-01

    In this work, a robust steganography framework to hide a color image into a stereo images is proposed. The embedding algorithm is performed via Discrete Cosine Transform (DCT) and Quantization Index Modulation-Dither Modulation (QIM-DM) hiding the secret data. Additionally, the Arnold's Cat Map Transform is applied in order to scramble the secret color image, guaranteeing better security and robustness of the proposed system. Novel framework has demonstrated better performance against JPEG compression attacks among other existing approaches. Besides, the proposed algorithm is developed taking into account the parallel paradigm in order to be implemented in multi-core CPU increasing the processing speed. The results obtained by the proposed framework show high values of PSNR and SSIM, which demonstrate imperceptibility and sufficient robustness against JPEG compression attacks.

  8. Stegano-Crypto Hiding Encrypted Data in Encrypted Image Using Advanced Encryption Standard and Lossy Algorithm

    Directory of Open Access Journals (Sweden)

    Ari Shawakat Tahir

    2015-12-01

    Full Text Available The Steganography is an art and science of hiding information by embedding messages within other, seemingly harmless messages and lots of researches are working in it. Proposed system is using AES Algorithm and Lossy technique to overcome the limitation of previous work and increasing the process’s speed. The sender uses AES Algorithm to encrypt message and image, then using LSB technique to hide encrypted data in encrypted message. The receive get the original data using the keys that had been used in encryption process. The proposed system has been implemented in NetBeans 7.3 software uses image and data in different size to find the system’s speed.

  9. An Attribute-Based Signcryption Scheme and Its Application in Information Hiding

    Institute of Scientific and Technical Information of China (English)

    PENG Changgen; WANG Weiru; TIAN Youliang; YUAN Zhilong

    2016-01-01

    In order to provide a secure, reliable and flexible way to hide information, a new attribute-based signcryption scheme based on ciphertext-policy and its se-curity proof are presented. This scheme not only can simul-taneously fulfil both authentication and confidentiality in an efficient way, but also implements a hierarchical decryp-tion in one group and also between different groups accord-ing to user’s authority (different users satisfying the same access structure can be considered as a group). We provide a solution to information hiding using our proposed scheme which can embed ciphertext into a carrier. Because the hi-erarchical decryption property, different users will obtain different message from the same carrier. Illegal user can not get any information without private key because mes-sage existed in the carrier is ciphertext. Such solution can be applied in sharing important message under the public network.

  10. A data hiding approach for the self-security of iris recognition

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Attacks to biometric data are the primary danger to the self-security of biometrics.To improve the iris feature template data security,a data hiding approach based on bit streams is proposed,in which an iris feature template is embedded into a face image. The proposed approach is applicable to present dominant techniques of iris recognition.With the low computation cost and the zero decoding-error-rate,this data hiding approach,embedding target biometric data into other biometric data for improving the security of target data in identity recognition,data storage and transmission,can deceive attackers more effectively.Furthermore,it does not degrade the iris recognition performances.Experimental results prove that the proposed approach can be used to protect iris feature templates and enhance the security of the iris recognition system itself.

  11. New Classification Methods for Hiding Information into Two Parts: Multimedia Files and Non Multimedia Files

    CERN Document Server

    Alanazi, Hamdan O; Zaidan, B B; Jalab, Hamid A; AL-Ani, Zaidoon Kh

    2010-01-01

    With the rapid development of various multimedia technologies, more and more multimedia data are generated and transmitted in the medical, commercial, and military fields, which may include some sensitive information which should not be accessed by or can only be partially exposed to the general users. Therefore, security and privacy has become an important, Another problem with digital document and video is that undetectable modifications can be made with very simple and widely available equipment, which put the digital material for evidential purposes under question .With the large flood of information and the development of the digital format Information hiding considers one of the techniques which used to protect the important information. The main goals for this paper, provides a general overview of the New Classification Methods for Hiding Information into Two Parts: Multimedia Files and Non Multimedia Files.

  12. 12th International Conference on Intelligent Information Hiding and Multimedia Signal Processing

    CERN Document Server

    Tsai, Pei-Wei; Huang, Hsiang-Cheh

    2017-01-01

    This volume of Smart Innovation, Systems and Technologies contains accepted papers presented in IIH-MSP-2016, the 12th International Conference on Intelligent Information Hiding and Multimedia Signal Processing. The conference this year was technically co-sponsored by Tainan Chapter of IEEE Signal Processing Society, Fujian University of Technology, Chaoyang University of Technology, Taiwan Association for Web Intelligence Consortium, Fujian Provincial Key Laboratory of Big Data Mining and Applications (Fujian University of Technology), and Harbin Institute of Technology Shenzhen Graduate School. IIH-MSP 2016 is held in 21-23, November, 2016 in Kaohsiung, Taiwan. The conference is an international forum for the researchers and professionals in all areas of information hiding and multimedia signal processing. .

  13. A new method for high-capacity information hiding in video robust against temporal desynchronization

    Science.gov (United States)

    Mitekin, Vitaly; Fedoseev, Victor A.

    2015-02-01

    This paper presents a new method for high-capacity information hiding in digital video and algorithms of embedding and extraction of hidden information based on this method. These algorithms do not require temporal synchronization to provide robustness against both malicious and non-malicious frame dropping (temporal desynchronization). At the same time, due to randomized distribution of hidden information bits across the video frames, the proposed method allows to increase the hiding capacity proportionally to the number of frames used for information embedding. The proposed method is also robust against "watermark estimation" attack aimed at estimation of hidden information without knowing the embedding key or non-watermarked video. Presented experimental results demonstrate declared features of this method.

  14. Reversible Data Hiding Based on Two-level HDWT Coefficient Histograms

    Directory of Open Access Journals (Sweden)

    Xu-Ren Luo

    2011-05-01

    Full Text Available In recent years, reversible data hiding has attracted much more attention than before. Reversibilitysignifies that the original media can be recovered without any loss from the marked media afterextracting the embedded message. This paper presents a new method that adopts two-level wavelettransform and exploits the feature of large wavelet coefficient variance to achieve the goal of highcapacity with imperceptibility. Our method differs from those of previous ones in which the waveletcoefficients histogram not gray-level histogram is manipulated. Besides, clever shifting rules areintroduced into histogram to avoid the decimal problem in pixel values after recovery to achievereversibility. With small alteration of the wavelet coefficients in the embedding process, and therefore lowvisual distortion is obtained in the marked image. In addition, an important feature of our design is thatthe use of threshold is much different from previous studies. The results indicate that our design issuperior to many other state-of-the-art reversible data hiding schemes.

  15. Application of Modified Digital Halftoning Techniques to Data Hiding in Personalized Stamps

    Institute of Scientific and Technical Information of China (English)

    Hsi-Chun Wang; Chi-Ming Lian; Pei-Chi Hsiao

    2004-01-01

    The objective of this research is to embed information in personalized stamps by modified digital halftoning techniques. The displaced and deformed halftone dots are used to encode data in the personalized stamps. Hidden information can be retrieved by either an optical decoder or digital image processing techniques.The results show that personalized stamps with value-added features like data hiding or digital watermarking can be successfully implemented.

  16. Suitability of the RGB Channels for a Pixel Manipulation in a Spatial Domain Data Hiding Techniques

    Directory of Open Access Journals (Sweden)

    Ante Poljicak

    2010-06-01

    Full Text Available The aim of this research was to determine which channel in rgb color space is the most suitable (regarding perceptibility for a pixel manipulation in a spatial domain data  hiding techniques. For this purpose three custom test targets were generated. The research also shows the behavior of two closely related colors in the ps (Print-Scan process. The results are interpreted using both a quantitative method (statistical comparison and a qualitative method (visual comparison.

  17. C#实现窗口自动隐藏%Form Automatically Hide with C#

    Institute of Scientific and Technical Information of China (English)

    涂显政

    2012-01-01

      该文介绍了如何利用C#语言,实现靠屏边窗口自动隐藏及鼠标指向后自动弹出。%  Mark a form with C#, the form can automatically hide when it close the edge of screen and it can recover to nor⁃mal when mouse point on it.

  18. Hiding Two Binary Images in Grayscale BMP Image via Five Modulus Method

    Directory of Open Access Journals (Sweden)

    Firas A. Jassim

    2014-05-01

    Full Text Available The aim of this study is to hide two binary BMP images in a single BMP grayscale image. The widespread technique in image steganography is to hide one image (stego image into another (cover image. The proposed novel method is to hide two binary images into one grayscale bitmap cover image. First of all, the proposed technique starts with transforming all grayscale cover image pixels into multiples of five using Five Modulus Method (FMM. Clearly, any modulus of five is either 0, 1, 2, 3, or 4. The transformed FMM cover image could be treated as a good host for carrying data. Obviously, it is known that the pixel value for the binary image is either 0 or 1. Therefore, by concatenating the two binary images, the composite results are 00, 01, 10 and 11. In fact, these concatenated values could be mapped using simple mapping that assigns a positive integer value such as 1 for 00, 2 for 01, 3 for 10 and 4 for 11. Consequently, a new matrix will be constructed that contains a number varying from 1 to 4 only. Fortunately, the four integer values are the same as the previously mentioned reminders of division by 5, hence, adding these four integers to the transformed FMM cover image. On the recipient side, a reverse process will be implemented to extract the two binary images. In terms of PSNR values, the cover image and the two extracted stego images have acceptable PSNR values, which yields that the proposed method is very efficient in information hiding.

  19. Suitability of the rgb Channels for a Pixel Manipulation in a Spatial Domain Data Hiding Techniques

    Directory of Open Access Journals (Sweden)

    Lidija Mandić

    2010-01-01

    Full Text Available The aim of this research was to determine which channel in rgb color space is the most suitable (regarding perceptibility for a pixel manipulation in a spatial domain data hiding techniques. For this purpose three custom test targets were generated. The research also shows the behavior of two closely related colors in the ps (Print-Scan process. The results are interpreted using both a quantitative method (statistical comparison and a qualitative method (visual comparison.

  20. Steganography and Hiding Data with Indicators-based LSB Using a Secret Key

    Directory of Open Access Journals (Sweden)

    W. Saqer

    2016-06-01

    Full Text Available Steganography is the field of science concerned with hiding secret data inside other innocent-looking data, called the container, carrier or cover, in a way that no one apart from the meant parties can suspect the existence of the secret data. There are many algorithms and techniques of concealing data. Each of which has its own way of hiding and its own advantages and limitations. In our research we introduce a new algorithm of hiding data. The algorithm uses the same technique used by the Least Significant Bit (LSB algorithm which is embedding secret data in the least significant bit(s of the bytes of the carrier. It differs from the LSB algorithm in that it does not embed the bytes of the cover data sequentially but it embeds into one bit or two bits at once. Actually it depends on indicators to determine where and how many bits to embed at a time. These indicators are two bits of each cover byte after the least two significant bits. The advantage of this algorithm over the LSB algorithm is the randomness used to confuse intruders as it does not use fixed sequential bytes and it does not always embed one bit at a time. This aims to increase the security of the technique. Also, the amount of cover data consumed is less because it sometimes embeds two bits at once.

  1. Spread spectrum image data hiding in the encrypted discrete cosine transform coefficients

    Science.gov (United States)

    Zhang, Xiaoqiang; Wang, Z. Jane

    2013-10-01

    Digital watermarking and data hiding are important tools for digital rights protection of media data. Spread spectrum (SS)-based watermarking and data-hiding approaches are popular due to their outstanding robustness, but their security might not be sufficient. To improve the security of SS, a SS-based image data-hiding approach is proposed by encrypting the discrete cosine transform coefficients of the host image with the piecewise linear chaotic map, before the operation of watermark embedding. To evaluate the performance of the proposed approach, simulations and analyses of its robustness and security are carried out. The average bit-error-rate values on 100 real images from the Berkeley segmentation dataset under the JPEG compression, additive Gaussian noise, salt and pepper noise, and cropping attacks are reported. Experimental results show that the proposed approach can maintain the high robustness of traditional SS schemes and, meanwhile, also improve the security. The proposed approach can extend the key space of traditional SS schemes from 10 to 10 and thus can resist brute-force attack and unauthorized detection watermark attack.

  2. A High-Capacity Image Data Hiding Scheme Using Adaptive LSB Substitution

    Directory of Open Access Journals (Sweden)

    H. Yang

    2009-12-01

    Full Text Available Many existing steganographic methods hide more secret data into edged areas than smooth areas in the host image, which does not differentiate textures from edges and causes serious degradation in actual edge areas. To avoid abrupt changes in image edge areas, as well as to achieve better quality of the stego-image, a novel image data hiding technique by adaptive Least Significant Bits (LSBs substitution is proposed in this paper. The scheme exploits the brightness, edges, and texture masking of the host image to estimate the number k of LSBs for data hiding. Pixels in the noise non-sensitive regions are embedded by a k-bit LSB substitution with a lager value of k than that of the pixels in noise sensitive regions. Moreover, an optimal pixel adjustment process is used to enhance stego-image visual quality obtained by simple LSB substitution method. To ensure that the adaptive number k of LSBs remains unchanged after pixel modification, the LSBs number is computed by the high-order bits rather than all the bits of the image pixel value. The theoretical analyses and experiment results show that the proposed method achieves higher embedding capacity and better stegoimage quality compared with some existing LSB methods.

  3. Pengaruh hide poison dan formalin terhadap sifat kulit dalam pengawet kulit kambing secara dikeringkan

    Directory of Open Access Journals (Sweden)

    Ignatius Sunaryo

    1991-06-01

    Full Text Available The objective of this study is know the effect of ide poison and formaline in the dried curing of goat skin. This study used 199 goat skins that were devided into seven groups od curing. Each group consisted of 17 goat skins. Those groups were : 3 groups of dried curing by hide poison of 0,1%, 0,3% and 0,5%; 3 groups of dried curing by formaline of 1%, 3% and 5%; and 1 groups of dried curing without any preserevation agent as control. After having stored for about 4 months, those skins then to be analized. Physical and chemical analysis werw carried out to evaluate the quality of the skin. Completely randomized design by Duncan’s test was used to analyze the dta. Based on this statistical analysis we can know that: the effect of hide poson in the dried curing of goat skins was the best. The quality of goat skins that were cured by hide poison was as follows : - the average tensile strength was the highest (886,30 kg/CM2, - the average of stretch was the lowest (14,50%, - the average iof hardness was the highest (201,90 kg/2,54 Cm, - the water content was the lowest (20%, and the damage was the smallest (10%.

  4. Design a Weight Based sorting distortion algorithm using Association rule Hiding for Privacy Preserving Data mining

    Directory of Open Access Journals (Sweden)

    R.Sugumar

    2011-12-01

    Full Text Available The security of the large database that contains certain crucial information, it will become a serious issue when sharing data to the network against unauthorized access. Privacy preserving data mining is a new research trend in privacy data for data mining and statistical database. Association analysis is a powerful tool for discovering relationships which are hidden in large database. Association rules hiding algorithms get strong an efficient performance for protecting confidential and crucial data. Data modification and rule hiding is one of the most important approaches for secure data. The objective of the proposed Weight Based Sorting Distortion (WBSD algorithm is to distort certain data which satisfies a particular sensitive rule. Then hide those transactions which support a sensitive rule and assigns them a priority and sorts them in ascending order according to the priority value of each rule. Then it uses these weights to compute the priority value for each transaction according to how weak the rule is that a transaction supports. Data distortion is one of the important methods to avoid this kind of scalability issues

  5. Information Hiding Method Using Best DCT and Wavelet Coefficients and ItsWatermark Competition

    Directory of Open Access Journals (Sweden)

    Hyunho Kang

    2015-03-01

    Full Text Available In recent years, information hiding and its evaluation criteria have been developed by the IHC (Information Hiding and its Criteria Committee of Japan. This committee was established in 2011 with the aim of establishing standard evaluation criteria for robust watermarks. In this study, we developed an information hiding method that satisfies the IHC evaluation criteria. The proposed method uses the difference of the frequency coefficients derived from a discrete cosine transform or a discrete wavelet transform. The algorithm employs a statistical analysis to find the best positions in the frequency domains for watermark insertion. In particular, we use the BCH (Bose-Chaudhuri-Hocquenghem (511,31,109 code to error correct the watermark bits and the BCH (63,16,11 code as the sync signal to withstand JPEG (Joint Photographic Experts Group compression and cropping attacks. Our experimental results showed that there were no errors in 10 HDTV-size areas after the second decompression. It should be noted that after the second compression, the file size should be less than 1 25 of the original size to satisfy the IHC evaluation criteria.

  6. Authentication and data hiding using a hybrid ROI-based watermarking scheme for DICOM images.

    Science.gov (United States)

    Al-Qershi, Osamah M; Khoo, Bee Ee

    2011-02-01

    Authenticating medical images using watermarking techniques has become a very popular area of research, and some works in this area have been reported worldwide recently. Besides authentication, many data-hiding techniques have been proposed to conceal patient's data into medical images aiming to reduce the cost needed to store data and the time needed to transmit data when required. In this paper, we present a new hybrid watermarking scheme for DICOM images. In our scheme, two well-known techniques are combined to gain the advantages of both and fulfill the requirements of authentication and data hiding. The scheme divides the images into two parts, the region of interest (ROI) and the region of non-interest (RONI). Patient's data are embedded into ROI using a reversible technique based on difference expansion, while tamper detection and recovery data are embedded into RONI using a robust technique based on discrete wavelet transform. The experimental results show the ability of hiding patient's data with a very good visual quality, while ROI, the most important area for diagnosis, is retrieved exactly at the receiver side. The scheme also shows some robustness against certain levels of salt and pepper and cropping noise.

  7. Efficient blind decoders for additive spread spectrum embedding based data hiding

    Science.gov (United States)

    Valizadeh, Amir; Wang, Z. Jane

    2012-12-01

    This article investigates efficient blind watermark decoding approaches for hidden messages embedded into host images, within the framework of additive spread spectrum (SS) embedding based for data hiding. We study SS embedding in both the discrete cosine transform and the discrete Fourier transform (DFT) domains. The contributions of this article are multiple-fold: first, we show that the conventional SS scheme could not be applied directly into the magnitudes of the DFT, and thus we present a modified SS scheme and the optimal maximum likelihood (ML) decoder based on the Weibull distribution is derived. Secondly, we investigate the improved spread spectrum (ISS) embedding, an improved technique of the traditional additive SS, and propose the modified ISS scheme for information hiding in the magnitudes of the DFT coefficients and the optimal ML decoders for ISS embedding are derived. We also provide thorough theoretical error probability analysis for the aforementioned decoders. Thirdly, sub-optimal decoders, including local optimum decoder (LOD), generalized maximum likelihood (GML) decoder, and linear minimum mean square error (LMMSE) decoder, are investigated to reduce the required prior information at the receiver side, and their theoretical decoding performances are derived. Based on decoding performances and the required prior information for decoding, we discuss the preferred host domain and the preferred decoder for additive SS-based data hiding under different situations. Extensive simulations are conducted to illustrate the decoding performances of the presented decoders.

  8. Turbulence beneath finite amplitude water waves

    Energy Technology Data Exchange (ETDEWEB)

    Beya, J.F. [Universidad de Valparaiso, Escuela de Ingenieria Civil Oceanica, Facultad de Ingenieria, Valparaiso (Chile); The University of New South Wales, Water Research Laboratory, School of Civil and Environmental Engineering, Sydney, NSW (Australia); Peirson, W.L. [The University of New South Wales, Water Research Laboratory, School of Civil and Environmental Engineering, Sydney, NSW (Australia); Banner, M.L. [The University of New South Wales, School of Mathematics and Statistics, Sydney, NSW (Australia)

    2012-05-15

    Babanin and Haus (J Phys Oceanogr 39:2675-2679, 2009) recently presented evidence of near-surface turbulence generated below steep non-breaking deep-water waves. They proposed a threshold wave parameter a {sup 2}{omega}/{nu} = 3,000 for the spontaneous occurrence of turbulence beneath surface waves. This is in contrast to conventional understanding that irrotational wave theories provide a good approximation of non-wind-forced wave behaviour as validated by classical experiments. Many laboratory wave experiments were carried out in the early 1960s (e.g. Wiegel 1964). In those experiments, no evidence of turbulence was reported, and steep waves behaved as predicted by the high-order irrotational wave theories within the accuracy of the theories and experimental techniques at the time. This contribution describes flow visualisation experiments for steep non-breaking waves using conventional dye techniques in the wave boundary layer extending above the wave trough level. The measurements showed no evidence of turbulent mixing up to a value of a {sup 2}{omega}/{nu} = 7,000 at which breaking commenced in these experiments. These present findings are in accord with the conventional understandings of wave behaviour. (orig.)

  9. Channelization of plumes beneath ice shelves

    KAUST Repository

    Dallaston, M. C.

    2015-11-11

    © 2015 Cambridge University Press. We study a simplified model of ice-ocean interaction beneath a floating ice shelf, and investigate the possibility for channels to form in the ice shelf base due to spatial variations in conditions at the grounding line. The model combines an extensional thin-film description of viscous ice flow in the shelf, with melting at its base driven by a turbulent ocean plume. Small transverse perturbations to the one-dimensional steady state are considered, driven either by ice thickness or subglacial discharge variations across the grounding line. Either forcing leads to the growth of channels downstream, with melting driven by locally enhanced ocean velocities, and thus heat transfer. Narrow channels are smoothed out due to turbulent mixing in the ocean plume, leading to a preferred wavelength for channel growth. In the absence of perturbations at the grounding line, linear stability analysis suggests that the one-dimensional state is stable to initial perturbations, chiefly due to the background ice advection.

  10. [Guided bone regeneration beneath titanium foils].

    Science.gov (United States)

    Otto, Katharina; Schopper, Christian; Ewers, Rolf; Lambrecht, J Thomas

    2004-01-01

    The aim of this study was to examine the clinical and histological bony healing process beneath titanium foils used for guided tissue regeneration as well as of the Frios Algipore graft which was applied with autologous bone. 66 sinus floor elevations were carried out and examined over a period of three years and eight months. A success rate of 64% was recorded with foil incorporation. Complications occurred in form of primary and secondary disturbances in the healing process caused by exposure of the foil. 12 of the 66 foils had to be removed early. In all but one case, the augmented bone material was macroscopically well integrated despite the loss of the foil. Primary stability of the inserted dental implants into the ossified augmented site after operations of the sinus maxillaris was reached in all cases with absence of post-operative complications, and in 94% when there was postoperative exposure of the membrane. Histologically, a thin layer of connective tissue poor in cells but rich in collagen fibers appeared underneath the titanium foil. This was followed by newly-formed bony tissue transforming into osseous lamella parallel to the membrane underneath the new periost. In 65 out of 66 cases a sufficient amount of stable bone was built up locally suggesting good bio-compatibility and barrier function. Further, the foil also provided mechanical rest and supporting function for the space underneath. However, the occurrence of healing complications in 36% of the cases showed a need to improve on the titanium foils.

  11. Java/JNI/C/Fortran makefile project for a Java plug-in and related Android app in Eclipse ADT bundle: A side-by-side comparison

    NARCIS (Netherlands)

    De Beer, R.; Van Ormondt, D.

    2015-01-01

    We have developed a Java/Fortran based application, called MonteCarlo, that enables the users can carry out Monte Carlo studies in the field of in vivo MRS. The application is supposed to be used as a tool for the jMRUI platform, being the in vivo MRS software system of the TRANSACT European Union p

  12. Pulsed dye laser vs. intense pulsed light for port-wine stains: a randomized side-by-side trial with blinded response evaluation

    DEFF Research Database (Denmark)

    Faurschou, A; Togsverd-Bo, K; Zachariae, C

    2009-01-01

    Corporation, Wayland, MA, U.S.A.) and IPL (StarLux, Lux G prototype handpiece, 500-670 and 870-1400 nm, 5-10 ms; Palomar Medical Technologies, Burlington, MA, U.S.A.). Settings depended on the preoperative lesional colour. Treatment outcome was evaluated by blinded, clinical evaluations and by skin...

  13. Building America Case Study: Side-by-Side Testing of Water Heating Systems: Results from 2013-2014 Evaluation Final Report, Cocoa, FL

    Energy Technology Data Exchange (ETDEWEB)

    Rothgeb, Stacey K [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Colon, C. [BA-PIRC; Martin, E. [BA-PIRC

    2017-08-24

    The Florida Solar Energy Center (FSEC) has completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). This report contains a summary of research activities regarding the evaluation of two residential electric heat pump water heaters (HPWHs), a solar thermal system utilizing a polymer glazed absorber and a high efficiency natural gas system.

  14. Building America Case Study: Side-by-Side Testing of Water Heating Systems: Results from the 2013–2014 Evaluation Final Report

    Energy Technology Data Exchange (ETDEWEB)

    C. Colon and E. Martin

    2017-08-24

    The Florida Solar Energy Center (FSEC) has completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). This report contains a summary of research activities regarding the evaluation of two residential electric heat pump water heaters (HPWHs), a solar thermal system utilizing a polymer glazed absorber and a high efficiency natural gas system.

  15. 上限式货币掉期:汇率保护与风险并存%Cap Currency Swap: Protection and Risk Exist Side by Side

    Institute of Scientific and Technical Information of China (English)

    刘晓红

    2006-01-01

    某企业借日元200亿元,期限20年,即2000年9月1日至2020年9月1日,利率为2.5%,每半年支付一次利息,2005年9月1日开始等额偿还本金。由于企业收汇为美元,与债务币种不匹配,日元升值将为企业带来无限汇率风险。方案一:普通货币掉期,方案二:欧式敲出货币掉期。

  16. Diagnosis and Treatment of Osteoporosis Before and After Fracture: A Side-by-Side Analysis of Commercially Insured and Medicare Advantage Osteoporosis Patients.

    Science.gov (United States)

    Weaver, Jessica; Sajjan, Shiva; Lewiecki, E Michael; Harris, Steven T

    2017-07-01

    Although treatment for osteoporosis is recommended by U.S. clinical guidelines, a lack of diagnosis and treatment is common among patients with osteoporotic fractures. To determine the rates of osteoporosis diagnosis and treatment before and after various types of fractures. This was a retrospective claims analysis using data from the Humana Medicare Advantage claims (Medicare group) and Optum Insight Clinformatics Data Mart commercial claims (Commercial group). Patients included in the study had a claim for a qualifying fracture occurring between January 2008 and December 2013 (the index fracture), were continuously enrolled in the health plan for ≥ 1 year before and after the index fracture, and were aged ≥ 65 years in the Medicare group or ≥ 50 years in the Commercial group at the time of the index fracture. Fragility fractures and osteoporosis diagnoses were identified from ICD-9-CM codes. Treatment for osteoporosis included oral and injectable therapies identified by National Drug Code numbers and Healthcare Common Procedure Coding System codes. Diagnosis and treatment rates were assessed during the 1-year periods before and after the index fracture. All analyses were conducted by fracture type (vertebral, hip, nonhip/nonvertebral [NHNV], and multiple), with stratification by age and sex. No comparisons were made between the Medicare and Commercial groups; rather, McNemar tests were used to compare prefracture versus postfracture diagnosis and treatment rates within each group. For inclusion in the Medicare group, 45,603 patients were identified, and 54,145 patients were identified for the Commercial group. In the prefracture period, the osteoporosis diagnosis rates ranged from 12.0% (NHNV) to 21.5% (vertebral) in the Medicare group and from 5.3% (NHNV) to 12.1% (vertebral) in the Commercial group. In the postfracture period, diagnosis rates significantly increased (P Commercial group. Pre-index treatment rates were similarly low, ranging from 9.4% (hip) to 16.6% (vertebral) among Medicare patients, and 7.5% (NHNV) to 14.4% (vertebral) in Commercial patients. Osteoporosis treatment rates improved significantly in the postfracture year, ranging from 12.5% (NHNV) to 26.5% (vertebral) among Medicare patients, and 8.3% (NHNV) to 21.4% (vertebral) in Commercial patients. Larger increases in diagnosis rates and smaller increases in treatment rates were observed in stratified analyses of men and women and of different age groups, with women and older patients having higher overall rates of diagnosis and treatment before and after fracture. In men and women, osteoporosis diagnosis rates were low before the index fracture and improved substantially after the fracture, yet still remained low overall (under 50%). Osteoporosis treatment rates among patients experiencing a fracture were low before the index fracture and improved only minimally afterwards. This study was funded by Merck & Co. Other than through the employer relationship disclosed here, Merck & Co. did not have a role in the study design, data collection, interpretation of the data, in writing of the manuscript, or in the decision to submit the manuscript for publication. Weaver is an employee of Merck & Co. Sajjan was an employee of Merck & Co. and owned stock in the company at the time of the study. Lewiecki has received consulting and/or speaker honoraria from Merck & Co., AbbVie, AgNovos Healthcare, Alexion Pharmaceuticals, Amgen, Eli Lilly and Company, Radius Health, Shire, and TheraNova, along with research grant support from Merck & Co., Amgen, and Eli Lilly and Company, and serves as a board member for the National Osteoporosis Foundation, the International Society for Clinical Densitometry, and the Osteoporosis Foundation of New Mexico. Harris has received consulting honoraria from Merck & Co., Alexion Pharmaceuticals, Amgen, Eli Lilly and Company, Gilead Sciences, Primus Pharmaceuticals, and Radius Health. Study concept and design were contributed by Weaver and Sajjan. Sajjan collected the data, and data interpretation was performed by all the authors. The manuscript was written and revised by Weaver, Lewiecki, and Harris.

  17. Assessment of left ventricular non-compaction in adults: side-by-side comparison of cardiac magnetic resonance imaging with echocardiography.

    Science.gov (United States)

    Thuny, Franck; Jacquier, Alexis; Jop, Bertrand; Giorgi, Roch; Gaubert, Jean-Yves; Bartoli, Jean-Michel; Moulin, Guy; Habib, Gilbert

    2010-03-01

    Two-dimensional echocardiography images obtained at end-diastole and end-systole and cardiac magnetic resonance (CMR) images obtained at end-diastole represent the three imaging methodologies validated for diagnosis of left ventricular non-compaction (LVNC). No study has compared these methodologies in assessing the magnitude of non-compaction. To compare two-dimensional echocardiography with CMR in the evaluation of patients with suspected LVNC. Sixteen patients (48+/-17 years) with LVNC underwent echocardiography and CMR within the same week. Echocardiography images obtained at end-diastole and end-systole were compared in a blinded fashion with those obtained by CMR at end-diastole to assess non-compaction in 17 anatomical segments. All segments could be analysed by CMR, whereas only 238 (87.5%) and 237 (87.1%) could be analysed by echocardiography at end-diastole and end-systole, respectively (p=0.002). Among the analysable segments, a two-layered structure was observed in 54.0% by CMR, 42.9% by echocardiography at end-diastole and 41.4% by echocardiography at end-systole (p=0.006). Similar distribution patterns were observed with the two echocardiographic methodologies. However, compared with echocardiography, CMR identified a higher rate of two-layered structures in the anterior, anterolateral, inferolateral and inferior segments. Echocardiography at end-systole underestimated the NC/C maximum ratio compared with CMR (p=0.04) and echocardiography at end-diastole (p=0.003). No significant difference was observed between CMR and echocardiography at end-diastole (p=0.83). Interobserver reproducibility of the NC/C maximum ratio was similar for the three methodologies. CMR appears superior to standard echocardiography in assessing the extent of non-compaction and provides supplemental morphological information beyond that obtained with conventional echocardiography.

  18. Crystal structure of Δ-[Ru(bpy)2dppz]2+ bound to mismatched DNA reveals side-by-side metalloinsertion and intercalation

    Science.gov (United States)

    Song, Hang; Kaiser, Jens T.; Barton, Jacqueline K.

    2012-08-01

    DNA mismatches represent a novel target in the development of diagnostics and therapeutics for cancer, because deficiencies in DNA mismatch repair are implicated in cancers, and cells that are repair-deficient show a high frequency of mismatches. Metal complexes with bulky intercalating ligands serve as probes for DNA mismatches. Here, we report the high-resolution (0.92 Å) crystal structure of the ruthenium ‘light switch’ complex Δ-[Ru(bpy)2dppz]2+ (bpy = 2,2‧-bipyridine and dppz = dipyridophenazine), which is known to show luminescence on binding to duplex DNA, bound to both mismatched and well-matched sites in the oligonucleotide 5‧-(dCGGAAATTACCG)2-3‧ (underline denotes AA mismatches). Two crystallographically independent views reveal that the complex binds mismatches through metalloinsertion, ejecting both mispaired adenosines. Additional ruthenium complexes are intercalated at well-matched sites, creating an array of complexes in the minor groove stabilized by stacking interactions between bpy ligands and extruded adenosines. This structure attests to the generality of metalloinsertion and metallointercalation as DNA binding modes.

  19. Java/JNI/C/Fortran makefile project for a Java plug-in and related Android app in Eclipse ADT bundle: A side-by-side comparison

    NARCIS (Netherlands)

    De Beer, R.; Van Ormondt, D.

    2015-01-01

    We have developed a Java/Fortran based application, called MonteCarlo, that enables the users can carry out Monte Carlo studies in the field of in vivo MRS. The application is supposed to be used as a tool for the jMRUI platform, being the in vivo MRS software system of the TRANSACT European Union

  20. HIDE & SEEK: End-to-end packages to simulate and process radio survey data

    Science.gov (United States)

    Akeret, J.; Seehars, S.; Chang, C.; Monstein, C.; Amara, A.; Refregier, A.

    2017-01-01

    As several large single-dish radio surveys begin operation within the coming decade, a wealth of radio data will become available and provide a new window to the Universe. In order to fully exploit the potential of these datasets, it is important to understand the systematic effects associated with the instrument and the analysis pipeline. A common approach to tackle this is to forward-model the entire system-from the hardware to the analysis of the data products. For this purpose, we introduce two newly developed, open-source Python packages: the HI Data Emulator (HIDE) and the Signal Extraction and Emission Kartographer (SEEK) for simulating and processing single-dish radio survey data. HIDE forward-models the process of collecting astronomical radio signals in a single-dish radio telescope instrument and outputs pixel-level time-ordered-data. SEEK processes the time-ordered-data, removes artifacts from Radio Frequency Interference (RFI), automatically applies flux calibration, and aims to recover the astronomical radio signal. The two packages can be used separately or together depending on the application. Their modular and flexible nature allows easy adaptation to other instruments and datasets. We describe the basic architecture of the two packages and examine in detail the noise and RFI modeling in HIDE, as well as the implementation of gain calibration and RFI mitigation in SEEK. We then apply HIDE &SEEK to forward-model a Galactic survey in the frequency range 990-1260 MHz based on data taken at the Bleien Observatory. For this survey, we expect to cover 70% of the full sky and achieve a median signal-to-noise ratio of approximately 5-6 in the cleanest channels including systematic uncertainties. However, we also point out the potential challenges of high RFI contamination and baseline removal when examining the early data from the Bleien Observatory. The fully documented HIDE &SEEK packages are available at http://hideseek.phys.ethz.ch/ and are published

  1. Mantle Structure Beneath Central South America

    Science.gov (United States)

    Vandecar, J. C.; Silver, P. G.; James, D. E.; Assumpcao, M.; Schimmel, M.; Zandt, G.

    2003-12-01

    Making use of 60 digital broadband seismic stations that have operated across central South America in recent years, we have undertaken an inversion for the upper- and uppermost lower-mantle P- and S-wave velocity structures beneath the region. We have combined data from four portable PASSCAL-type experiments as well as the 3 GTSN permanent stations (LPAZ, BDFB and CPUP) and 1 Geoscope station (SPB) located in the region. The portable data were deployed at various times between 1992 and 1999 and include: 28 sites from the Brazilian Lithosphere Seismic Project (BLSP: Carnegie Institution of Washington and Universidade de Sao Paulo), 16 sites from the Broadband ANdean JOint experiment (BANJO: Carnegie Institution of Washington and University of Arizona), 8 sites from the Seismic Exploration of the Deep Altiplano project (SEDA: Lawrence Livermore National Laboratory) and 4 sites from the University of Brasilia. The P- and S-wave relative delay times are independently obtained via a multi-channel cross correlation of band-passed waveforms for each teleseismic event. These data are then inverted using an iterative, robust, non-linear scheme which parameterizes the 3-D velocity variations as splines under tension constrained at over 120,000 nodes across South America between latitudes of 15 and 30 degrees South. Amongst other features, we robustly image the high-velocity subducting Nazca plate penetrating into the lower mantle and the high-velocity root of the ~3.2 Gyr old Sao Francisco Craton extending to depths of 200-300 km. We will discuss the consistency between our tomographic models and predictions of dynamic mantle models based on plate tectonic reconstructions of subduction.

  2. Remote Oil Spill Detection and Monitoring Beneath Sea Ice

    Science.gov (United States)

    Polak, Adam; Marshall, Stephen; Ren, Jinchang; Hwang, Byongjun (Phil); Hagan, Bernard; Stothard, David J. M.

    2016-08-01

    The spillage of oil in Polar Regions is particularly serious due to the threat to the environment and the difficulties in detecting and tracking the full extent of the oil seepage beneath the sea ice. Development of fast and reliable sensing techniques is highly desirable. In this paper hyperspectral imaging combined with signal processing and classification techniques are proposed as a potential tool to detect the presence of oil beneath the sea ice. A small sample, lab based experiment, serving as a proof of concept, resulted in the successful identification of oil presence beneath the thin ice layer as opposed to the other sample with ice only. The paper demonstrates the results of this experiment that granted a financial support to execute full feasibility study of this technology for oil spill detection beneath the sea ice.

  3. Mantle structure beneath the western edge of the Colorado Plateau

    Science.gov (United States)

    Sine, C.R.; Wilson, D.; Gao, W.; Grand, S.P.; Aster, R.; Ni, J.; Baldridge, W.S.

    2008-01-01

    Teleseismic traveltime data are inverted for mantle Vp and Vs variations beneath a 1400 km long line of broadband seismometers extending from eastern New Mexico to western Utah. The model spans 600 km beneath the moho with resolution of ???50 km. Inversions show a sharp, large-magnitude velocity contrast across the Colorado Plateau-Great Basin transition extending ???200 km below the crust. Also imaged is a fast anomaly 300 to 600 km beneath the NW portion of the array. Very slow velocities beneath the Great Basin imply partial melting and/or anomalously wet mantle. We propose that the sharp contrast in mantle velocities across the western edge of the Plateau corresponds to differential lithospheric modification, during and following Farallon subduction, across a boundary defining the western extent of unmodified Proterozoic mantle lithosphere. The deep fast anomaly corresponds to thickened Farallon plate or detached continental lithosphere at transition zone depths. Copyright 2008 by the American Geophysical Union.

  4. Geometric and oceanographic controls on melting beneath Pine Island Glacier

    National Research Council Canada - National Science Library

    De Rydt, J; Holland, P. R; Dutrieux, P; Jenkins, A

    2014-01-01

    .... As a result, a large ocean cavity has formed behind the ridge, strongly controlling the ocean circulation beneath the ice shelf and modulating the ocean water properties that cause ice melting...

  5. Foundering lithosphere imaged beneath the southern Sierra Nevada, California, USA.

    Science.gov (United States)

    Boyd, Oliver S; Jones, Craig H; Sheehan, Anne F

    2004-07-30

    Seismic tomography reveals garnet-rich crust and mantle lithosphere descending into the upper mantle beneath the southeastern Sierra Nevada. The descending lithosphere consists of two layers: an iron-rich eclogite above a magnesium-rich garnet peridotite. These results place descending eclogite above and east of high P wave speed material previously imaged beneath the southern Great Valley, suggesting a previously unsuspected coherence in the lithospheric removal process.

  6. Sensor and Actuator Fault-Hiding Reconfigurable Control Design for a Four-Tank System Benchmark

    DEFF Research Database (Denmark)

    Hameed, Ibrahim; El-Madbouly, Esam I; Abdo, Mohamed I

    2015-01-01

    Fault detection and compensation plays a key role to fulfill high demands for performance and security in today's technological systems. In this paper, a fault-hiding (i.e., tolerant) control scheme that detects and compensates for actuator and sensor faults in a four-tank system benchmark...... Invariant (LTI) system where virtual sensors and virtual actuators are used to correct faulty performance through the use of a pre-fault performance. Simulation results showed that the developed approach can handle different types of faults and able to completely and instantly recover the original system...

  7. Information hiding based on double random-phase encoding and public-key cryptography.

    Science.gov (United States)

    Sheng, Yuan; Xin, Zhou; Alam, Mohammed S; Xi, Lu; Xiao-Feng, Li

    2009-03-01

    A novel information hiding method based on double random-phase encoding (DRPE) and Rivest-Shamir-Adleman (RSA) public-key cryptosystem is proposed. In the proposed technique, the inherent diffusion property of DRPE is cleverly utilized to make up the diffusion insufficiency of RSA public-key cryptography, while the RSA cryptosystem is utilized for simultaneous transmission of the cipher text and the two phase-masks, which is not possible under the DRPE technique. This technique combines the complementary advantages of the DPRE and RSA encryption techniques and brings security and convenience for efficient information transmission. Extensive numerical simulation results are presented to verify the performance of the proposed technique.

  8. Major disruption of D'' beneath Alaska: D'' Beneath Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Daoyuan [Laboratory of Seismology and Physics of Earth' s Interior, School of Earth and Space Sciences, University of Science and Technology of China, Hefei Anhui China; National Geophysics Observatory at Mengcheng, Anhui China; Helmberger, Don [Seismological Laboratory, California Institute of Technology, Caltech, Pasadena California USA; Miller, Meghan S. [Department of Earth Sciences, University of Southern California, Los Angeles California USA; Jackson, Jennifer M. [Seismological Laboratory, California Institute of Technology, Caltech, Pasadena California USA

    2016-05-01

    D'' represents one of the most dramatic thermal and compositional layers within our planet. In particular, global tomographic models display relatively fast patches at the base of the mantle along the circum-Pacific which are generally attributed to slab debris. Such distinct patches interact with the bridgmanite (Br) to post-bridgmanite (PBr) phase boundary to generate particularly strong heterogeneity at their edges. Most seismic observations for the D'' come from the lower mantle S wave triplication (Scd). Here we exploit the USArray waveform data to examine one of these sharp transitions in structure beneath Alaska. From west to east beneath Alaska, we observed three different characteristics in D'': (1) the western region with a strong Scd, requiring a sharp δVs = 2.5% increase; (2) the middle region with no clear Scd phases, indicating a lack of D'' (or thin Br-PBr layer); and (3) the eastern region with strong Scd phase, requiring a gradient increase in δVs. To explain such strong lateral variation in the velocity structure, chemical variations must be involved. We suggest that the western region represents relatively normal mantle. In contrast, the eastern region is influenced by a relic slab that has subducted down to the lowermost mantle. In the middle region, we infer an upwelling structure that disrupts the Br-PBr phase boundary. Such an interpretation is based upon a distinct pattern of travel time delays, waveform distortions, and amplitude patterns that reveal a circular-shaped anomaly about 5° across which can be modeled synthetically as a plume-like structure rising about 400 km high with a shear velocity reduction of ~5%, similar to geodynamic modeling predictions of upwellings.

  9. Pre-slaughter, slaughter and post-slaughter defects of skins and hides at the Sheba Tannery and Leather Industry, Tigray region, northern Ethiopia.

    Science.gov (United States)

    Kahsay, Tesfay; Negash, Guesh; Hagos, Yohannes; Hadush, Birhanu

    2015-08-21

    Skins and hides are perishable resources that can be damaged by parasitic diseases and human error, which result in downgrading or rejection. This study was conducted to identify defect types and to determine their prevalence in pickled sheep and wet blue goat skins and wet blue hides. Each selected skin or hide was examined for defects in natural light and the defects were graded according to established quality criteria in Ethiopian standard manuals. Major defects were captured by digital photography. The major pre-slaughter defects included scratches (64.2%), cockle (ekek) (32.8%), wounds or scars (12.6%), lesions from pox or lumpy skin disease (6.1%), poor substance (5%), branding marks (2.3%) and tick bites (1.5%). The presence of grain scratches in wet blue hides (76.3%) was significantly higher than in pickled sheep (67.2%) and wet blue goat (59.1%) skins. The major slaughter defects included flay cuts or scores, holes, poor pattern and vein marks, with a higher occurrence in wet blue goat skins (28.7%; P < 0.001) than in wet blue hides (22.8%) and pickled sheep skins (11.1%). The most prevalent postslaughter defects were grain cracks (14.9%), hide beetle damage (8%), damage caused by heat or putrefaction (3.7%) and machine-induced defects (0.5%). Grain cracks (27.04%) and hide beetle damage (13.9%) in wet blue goat skins were significantly more common than in wet blue hides and pickled sheep skins. These defects cause depreciation in the value of the hides and skins. Statistically significant (P < 0.001) higher rejection rates were recorded for wet blue hides (82.9%) than for pickled sheep skins (18.3%) and wet blue goat skins (8.5%). Improved animal health service delivery, effective disease control strategies and strong collaboration between stakeholders are suggested to enhance the quality of skins and hides.

  10. A Novel Approach for Arabic Text Steganography Based on the “BloodGroup” Text Hiding Method

    Directory of Open Access Journals (Sweden)

    S. Malalla,

    2017-04-01

    Full Text Available Steganography is the science of hiding certain messages (data in groups of irrelevant data possibly of other form. The purpose of steganography is covert communication to hide the existence of a message from an intermediary. Text Steganography is the process of embedding secret message (text in another text (cover text so that the existence of secret message cannot be detected by a third party. This paper presents a novel approach for text steganography using the Blood Group (BG method based on the behavior of blood group. Experimentally it is found that the proposed method got good results in capacity, hiding capacity, time complexity, robustness, visibility, and similarity which shows its superiority as compared to most several existing methods.

  11. Privacy-Aware Image Encryption Based on Logistic Map and Data Hiding

    Science.gov (United States)

    Sun, Jianglin; Liao, Xiaofeng; Chen, Xin; Guo, Shangwei

    The increasing need for image communication and storage has created a great necessity for securely transforming and storing images over a network. Whereas traditional image encryption algorithms usually consider the security of the whole plain image, region of interest (ROI) encryption schemes, which are of great importance in practical applications, protect the privacy regions of plain images. Existing ROI encryption schemes usually adopt approximate techniques to detect the privacy region and measure the quality of encrypted images; however, their performance is usually inconsistent with a human visual system (HVS) and is sensitive to statistical attacks. In this paper, we propose a novel privacy-aware ROI image encryption (PRIE) scheme based on logistical mapping and data hiding. The proposed scheme utilizes salient object detection to automatically, adaptively and accurately detect the privacy region of a given plain image. After private pixels have been encrypted using chaotic cryptography, the significant bits are embedded into the nonprivacy region of the plain image using data hiding. Extensive experiments are conducted to illustrate the consistency between our automatic ROI detection and HVS. Our experimental results also demonstrate that the proposed scheme exhibits satisfactory security performance.

  12. Reversible Data Hiding Using Two Marked Images Based on Adaptive Coefficient-Shifting Algorithm

    Directory of Open Access Journals (Sweden)

    Ching-Yu Yang

    2012-01-01

    Full Text Available This paper proposes a novel form of reversible data hiding using two marked images by employing the adaptive coefficient-shifting (ACS algorithm. The proposed ACS algorithm consists of three parts: the minimum-preserved scheme, the minimum-preserved with squeezing scheme, and the base-value embedding scheme. More specifically, each input block of a host image can be encoded to two stego-blocks according to three predetermined rules by the above three schemes. Simulations validate that the proposed method not only completely recovers the host medium but also losslessly extracts the hidden message. The proposed method can handle various kinds of images without any occurrence of overflow/underflow. Moreover, the payload and peak signal-to-noise ratio (PSNR performance of the proposed method is superior to that of the conventional invertible data hiding schemes. Furthermore, the number of shadows required by the proposed method is less than that required by the approaches which are based upon secret image sharing with reversible steganography.

  13. Evaluating Quality of Chaotic Pseudo-Random Generators: Application to Information Hiding

    CERN Document Server

    Bahi, Jacques M; Guyeux, Christophe; Wang, Qianxue

    2011-01-01

    Guaranteeing the security of information transmitted through the Internet, against passive or active attacks, is a major concern. The discovery of new pseudo-random number generators with a strong level of security is a field of research in full expansion, due to the fact that numerous cryptosystems and data hiding schemes are directly dependent on the quality of these generators. At the conference Internet`09, we described a generator based on chaotic iterations which behaves chaotically as defined by Devaney. In this paper which is an extension of the work presented at the conference Internet`10, the proposal is to improve the speed, the security, and the evaluation of this generator, to make its use more relevant in the Internet security context. In order to do so, a comparative study between various generators is carried out and statistical results are improved. Finally, an application in the information hiding framework is presented with details, to give an illustrative example of the use of such a gener...

  14. HIDE & SEEK: End-to-End Packages to Simulate and Process Radio Survey Data

    CERN Document Server

    Akeret, Joel; Chang, Chihway; Monstein, Christian; Amara, Adam; Refregier, Alexandre

    2016-01-01

    As several large radio surveys begin operation within the coming decade, a wealth of radio data will become available and provide a new window to the Universe. In order to fully exploit the potential of these data sets, it is important to understand the systematic effects associated with the instrument and the analysis pipeline. A common approach to tackle this is to forward-model the entire system - from the hardware to the analysis of the data products. For this purpose, we introduce two newly developed, open-source Python packages: the HI Data Emulator (HIDE) and the Signal Extraction and Emission Kartographer (SEEK) for simulating and processing radio survey data. HIDE forward-models the process of collecting astronomical radio signals in a single dish radio telescope instrument and outputs pixel-level time-ordered-data. SEEK processes the time-ordered-data, removes artifacts from Radio Frequency Interference (RFI), automatically applies flux calibration, and aims to recover the astronomical radio signal....

  15. Secure Reversible Data Hiding in Encrypted Images by Allocating Memory before Encryption via Security keys

    Directory of Open Access Journals (Sweden)

    Priya Jambhulkar

    2015-11-01

    Full Text Available Digital image and information embedding system have number of important multimedia applications. Recently, attention is paid to reversible data hiding (RDH in encrypted images is more, since it maintains the excellent property that the original cover can be lossless recovered after embedded data is extracted while protecting the image content’s confidentiality. RDH is a technique used to hide data inside image for high security in such a way that original data is not visible. All previous methods embed data by reversibly vacating room from the encrypted images, which may be subject to some errors on data extraction and/or image restoration. In this paper, we propose another method in which we simply encrypt an image without its header by using our own algorithm. And thus it is easy for the data hider to reversibly embed data in the encrypted image. The proposed method can achieve real reversibility, that is, data extraction and image recovery are free of any error.

  16. Towards fraud-proof ID documents using multiple data hiding technologies and biometrics

    Science.gov (United States)

    Picard, Justin; Vielhauer, Claus; Thorwirth, Niels

    2004-06-01

    Identity documents, such as ID cards, passports, and driver's licenses, contain textual information, a portrait of the legitimate holder, and eventually some other biometric characteristics such as a fingerprint or handwritten signature. As prices for digital imaging technologies fall, making them more widely available, we have seen an exponential increase in the ease and the number of counterfeiters that can effectively forge documents. Today, with only limited knowledge of technology and a small amount of money, a counterfeiter can effortlessly replace a photo or modify identity information on a legitimate document to the extent that it is very diffcult to differentiate from the original. This paper proposes a virtually fraud-proof ID document based on a combination of three different data hiding technologies: digital watermarking, 2-D bar codes, and Copy Detection Pattern, plus additional biometric protection. As will be shown, that combination of data hiding technologies protects the document against any forgery, in principle without any requirement for other security features. To prevent a genuine document to be used by an illegitimate user,biometric information is also covertly stored in the ID document, to be used for identification at the detector.

  17. Temporal cloak with large fractional hiding window at telecommunication data rate

    Science.gov (United States)

    Zhou, Feng; Dong, Jianji; Yan, Siqi; Yang, Ting

    2017-04-01

    We design and experimentally investigate a temporal cloak scheme using ultrashort pulse compression and time-domain Fraunhofer diffraction. An input continuous-wave probe beam is compressed to ultrashort pulse train based on self-phase modulation effect and chirp compensation using single mode fiber. Accordingly, wide temporal gaps appear to act as the cloaking windows. The train of ultrashort pulses can be converted to continuous wave after experiencing enough dispersion, indicating that the temporal gaps are closed. Thus, any time events will be hidden in the temporal gaps from observers. In our study, we demonstrated a temporal cloak system, which is able to hide 88% of the whole time period and cloak pseudorandom digital data at a bitrate of 10 Gbit/s. The relationships of cloaking window fraction versus pump power and the condition of cloaking off are also investigated. These results present a new feasible way towards obtaining a high-fractional cloaking window at telecommunication data rate and hiding real-world messages.

  18. Hide unhairing and characterization of commercial enzymes used in leather manufacture

    Directory of Open Access Journals (Sweden)

    A Dettmer

    2011-09-01

    Full Text Available The enzymatic treatment of hides in tannery processes is a promising technology. However, the reaction kinetics of commercial enzymes available to the leather industry are not fully understood and their activities have been mainly determined with model proteins such as casein as substrate, which are not of direct relevance for cattle hides. Therefore, it is important to determine their activities on collagen and keratin, the main proteins of skin, in order to use these enzymes in leather processing. This work describes the study of five proteases, used commercially in tanneries, to assess their ability to act upon collagen and keratin and to determine their unhairing. Results showed that all commercial enzymes tested had more activity on collagen than on keratin. Unhairing was also tested and four out of the five enzymes tested showed some unhairing activity. Optima of the temperature and pH of the enzymes were very similar for all five enzymes, with maximal activities around 55ºC and pH 9 to 12, respectively.

  19. Modified Approach for Hiding Sensitive Association Rules for Preserving Privacy in Database

    Directory of Open Access Journals (Sweden)

    Tania Banerjee

    2014-03-01

    Full Text Available Data mining is the process of analyzing large database to find useful patterns. The term pattern refers to the items which are frequently occurring in set of transaction. The frequent patterns are used to find association between sets of item. The efficiency of mining association rules and confidentiality of association rule is becoming one of important area of knowledge discovery in database. This paper is organized into two sections. In the system Apriori algorithm is being presented that efficiently generates association rules. These reduces unnecessary database scan at time of forming frequent large item sets .We have tried to give contribution to improved Apriori algorithm by hiding sensitive association rules which are generated by applying improved Apriori algorithm on supermarket database. In this paper we have used novel approach that strategically modifies few transactions in transaction database to decrease support and confidence of sensitive rule without producing any side effects. Thus in the paper we have efficiently generated frequent item set sets by applying Improved Apriori algorithm and generated association rules by applying minimum support and minimum confidence and then we went one step further to identify sensitive rules and tried to hide them without any side effects to maintain integrity of data without generating spurious rules.

  20. Double Hiding Information in Color Image File Based on Classical LSB Method

    Directory of Open Access Journals (Sweden)

    Aymen Mudheher Badr

    2014-07-01

    Full Text Available This study presents a two principles, Cryptography and Steganography, each tow methods work separately from the other to ensure a secure content. We are developed an algorithm to increase the safety and reliability of the copyrights of the images or books (etc. that published on the internet by providing a watermark image (as logo hiding inside the original file that we want product it. Firstly reading image (the logo image, convert it to binary and encrypted it by using EX-OR with a secret key and embedding it inside a gray image in the LSB (in the 1st and hiding first key in the 2nd bit and the second key in the 3rd bit, then we embedding them in the LSB of Original image in RGB to be protected. The two secret keys, first one as an encryption key and the second key using as signature (data that have been taken from the cover image (original to make sure the reliability of the image transmitted via the Internet.

  1. A one-time pad encryption method combining full-phase image encryption and hiding

    Science.gov (United States)

    Li, Jiaosheng; Xiong, Jiaxiang; Zhang, Qinnan; Zhong, Liyun; Zhou, Yunfei; Li, Jun; Lu, Xiaoxu

    2017-08-01

    A one-time pad encryption method combining full-phase image encryption and hiding is proposed. Firstly, original images are encoded in the phase and encrypted by phase keys loaded on the phase-only liquid crystal spatial light modulator, where the phase keys can be distributed using a quantum key distribution method. Subsequently, a host image is introduced to produce a reference wave, and overlap with an object wave to form an interferogram. Finally, based on phase-shifting interferometry, we can achieve the above encrypted image hiding. Both the simulation and experiment research demonstrate the feasibility of the proposed method, meanwhile the key and the encrypted image can be changed randomly, so the proposed system reveals the high flexibility, anti-attack ability and can be used to implement the one-time pad to achieve absolute secure transmission with the quantum key distribution method. Moreover, system security will be improved due to the fact that encryption information hidden in the host image can be treated as background noise, which does not attract the attention of the attacker.

  2. A REVIEW ON HEAVY METALS CONTENTS IN HIDE, SKIN AND PROCESSED LEATHERS

    Directory of Open Access Journals (Sweden)

    KOIZHAIGANOVA Meruyert

    2016-05-01

    Full Text Available Heavy metals are metals with high atomic weight which can be deposited in soil, water, plants and animals. It is generally known that mammal tissues are good bioindicators of trace elements, including heavy metals. Heavy metal analysis serves to identify and quantify the elements that are a potential hazard to the consumer after varying levels of contact. Usage area of leather is increasingly expanding in these days and it has also become a material requested and demanded by effect of fashion. Leather must protect its appearance and physical stability and also be problem-free in ecological terms and harmless to human health. There is a lack of data concerning the content of toxic elements in raw hide and skin of animals. Mainly information concerning metals content, including toxic ones, in processed leathers may be found in the literature. The aim of the present study was to review and compare the content of some heavy metals in raw hide, skin and the processed leathers in order to evaluate their accumulation and transition to the end-up product.

  3. Efficacy of octenidine hydrochloride for reducing Escherichia coli O157:H7, Salmonella spp., and Listeria monocytogenes on cattle hides.

    Science.gov (United States)

    Baskaran, Sangeetha Ananda; Upadhyay, Abhinav; Upadhyaya, Indu; Bhattaram, Varunkumar; Venkitanarayanan, Kumar

    2012-06-01

    The efficacy of octenidine hydrochloride (OH; 0.025, 0.15, and 0.25%) for inactivating Escherichia coli O157:H7, Salmonella spp., and Listeria monocytogenes on cattle hides was investigated at 23°C in the presence and absence of bovine feces. All tested concentrations of OH were effective in decreasing more than 5.0 log CFU of bacteria/cm(2) in 5 min (P < 0.01). The results suggest that OH could be used to decontaminate cattle hides; however, further studies under commercial settings are necessary to validate these results.

  4. Mantle discontinuities beneath Izu-Bonin and the implications

    Institute of Scientific and Technical Information of China (English)

    臧绍先; 周元泽; 蒋志勇

    2003-01-01

    The SdP, pdP and sdP phases are picked up with the Nth root slant stack method from the digital waveform data recorded by the networks and arrays in USA, Germany and Switzerland for the earthquakes occurring beneath Izu-Bonin and Japan Sea. The mantle discontinuities and the effects of subducting slab on the 660 km and 410 km discontinuities are studied. It is found that there are mantle discontinuities existing at the depths of 170, 220, 300, 410, 660, 850 and 1150 km. Beneath Izu-Bonin, the 410 km discontinuity is elevated, while the 660 km discontinuity is depressed; for both discontinuities, there are regionalized differences. Beneath Japan Sea, however, there is no depth variation of the 410 km discontinuity, and the 660 km discontinuity is depressed without obvious effect of the subducting slab.

  5. Evaluation of bacteriophage application to cattle in lairage at beef processing plants to reduce Escherichia coli O157:H7 prevalence on hides and carcasses

    Science.gov (United States)

    Escherichia coli O157:H7 is a major food safety concern for the beef industry. Several studies have provided evidence that cattle hides are the main source of beef carcass contamination during processing and that reductions in the E. coli O157:H7 load on the hides of cattle entering processing faci...

  6. Seismic imaging of the downwelling Indian lithosphere beneath central Tibet.

    Science.gov (United States)

    Tilmann, Frederik; Ni, James

    2003-05-30

    A tomographic image of the upper mantle beneath central Tibet from INDEPTH data has revealed a subvertical high-velocity zone from approximately 100- to approximately 400-kilometers depth, located approximately south of the Bangong-Nujiang Suture. We interpret this zone to be downwelling Indian mantle lithosphere. This additional lithosphere would account for the total amount of shortening in the Himalayas and Tibet. A consequence of this downwelling would be a deficit of asthenosphere, which should be balanced by an upwelling counterflow, and thus could explain the presence of warm mantle beneath north-central Tibet.

  7. Non-blind Data hiding for RGB images using DCT-based fusion and H.264 compression concepts

    Directory of Open Access Journals (Sweden)

    Safwat Hamad

    Full Text Available Steganography is the field of research that provides innovative solutions to the problem of secure data communication. In this paper, a non-blind data hiding technique is proposed which is based on data fusion between both the cover and the secret images. ...

  8. Subduction beneath Eurasia in connection with the Mesozoic Tethys

    NARCIS (Netherlands)

    Spakman, W.

    2007-01-01

    In this paper we present new results concerning the existence and subduction of Meso-Tethyan oceanic lithosphere in the upper mantle beneath Europe, the Mediterranean and the Middle-East. The results arise from a large scale body wave tomographic analysis of the upper mantle in this region. It is sh

  9. Deep long-period earthquakes beneath Washington and Oregon volcanoes

    Science.gov (United States)

    Nichols, M.L.; Malone, S.D.; Moran, S.C.; Thelen, W.A.; Vidale, J.E.

    2011-01-01

    Deep long-period (DLP) earthquakes are an enigmatic type of seismicity occurring near or beneath volcanoes. They are commonly associated with the presence of magma, and found in some cases to correlate with eruptive activity. To more thoroughly understand and characterize DLP occurrence near volcanoes in Washington and Oregon, we systematically searched the Pacific Northwest Seismic Network (PNSN) triggered earthquake catalog for DLPs occurring between 1980 (when PNSN began collecting digital data) and October 2009. Through our analysis we identified 60 DLPs beneath six Cascade volcanic centers. No DLPs were associated with volcanic activity, including the 1980-1986 and 2004-2008 eruptions at Mount St. Helens. More than half of the events occurred near Mount Baker, where the background flux of magmatic gases is greatest among Washington and Oregon volcanoes. The six volcanoes with DLPs (counts in parentheses) are Mount Baker (31), Glacier Peak (9), Mount Rainier (9), Mount St. Helens (9), Three Sisters (1), and Crater Lake (1). No DLPs were identified beneath Mount Adams, Mount Hood, Mount Jefferson, or Newberry Volcano, although (except at Hood) that may be due in part to poorer network coverage. In cases where the DLPs do not occur directly beneath the volcanic edifice, the locations coincide with large structural faults that extend into the deep crust. Our observations suggest the occurrence of DLPs in these areas could represent fluid and/or magma transport along pre-existing tectonic structures in the middle crust. ?? 2010 Elsevier B.V.

  10. Buckling instabilities of subducted lithosphere beneath the transition zone

    NARCIS (Netherlands)

    Ribe, N.M.; Stutzmann, E.; Ren, Y.; Hilst, R.D. van der

    2007-01-01

    A sheet of viscous fluid poured onto a surface buckles periodically to generate a pile of regular folds. Recent tomographic images beneath subduction zones, together with quantitative fluid mechanical scaling laws, suggest that a similar instability can occur when slabs of subducted oceanic

  11. Image fusion using wavelet transform and its application to asymmetric cryptosystem and hiding.

    Science.gov (United States)

    Mehra, Isha; Nishchal, Naveen K

    2014-03-10

    Image fusion is a popular method which provides better quality fused image for interpreting the image data. In this paper, color image fusion using wavelet transform is applied for securing data through asymmetric encryption scheme and image hiding. The components of a color image corresponding to different wavelengths (red, green, and blue) are fused together using discrete wavelet transform for obtaining a better quality retrieved color image. The fused color components are encrypted using amplitude- and phase-truncation approach in Fresnel transform domain. Also, the individual color components are transformed into different cover images in order to result disguising information of input image to an attacker. Asymmetric keys, Fresnel propagation parameters, weighing factor, and three cover images provide enlarged key space and hence enhanced security. Computer simulation results support the idea of the proposed fused color image encryption scheme.

  12. An improved algorithm for information hiding based on features of Arabic text: A Unicode approach

    Directory of Open Access Journals (Sweden)

    A.A. Mohamed

    2014-07-01

    Full Text Available Steganography means how to hide secret information in a cover media, so that other individuals fail to realize their existence. Due to the lack of data redundancy in the text file in comparison with other carrier files, text steganography is a difficult problem to solve. In this paper, we proposed a new promised steganographic algorithm for Arabic text based on features of Arabic text. The focus is on more secure algorithm and high capacity of the carrier. Our extensive experiments using the proposed algorithm resulted in a high capacity of the carrier media. The embedding capacity rate ratio of the proposed algorithm is high. In addition, our algorithm can resist traditional attacking methods since it makes the changes in carrier text as minimum as possible.

  13. ENTROPY BASED DATA HIDING ON DOCUMENT IMAGES APPLIED ON DRDM APPROACH

    Directory of Open Access Journals (Sweden)

    Sadia Aslam

    2013-03-01

    Full Text Available This paper presents a data hiding application for document images providing security. Document images should be in bitmap format as well as grayscale in nature otherwise the developed system will automatically change it to grayscale. The system accepts any grayscale document image as an input and applies the developed technique on it. Developed technique is based on Entropy Based that selects the suitable areas in an image for that data insertion purpose. Output produced by the system is the processed document that is data embedded. Processed document should not look different from the original image means its visual quality should be high. The system is successfully tested for the test cases generated to check the effectiveness, quality and validation of the system. The system is developed using Matlab 7.7.0 (R2008b for the development of front end as well as the back end.

  14. Costly hide and seek pays: Unexpected consequences of deceit in a social dilemma

    CERN Document Server

    Szolnoki, Attila

    2014-01-01

    Deliberate deceptiveness intended to gain an advantage is commonplace in human and animal societies. In a social dilemma, an individual may only pretend to be a cooperator to elicit cooperation from others, while in reality he is a defector. With this as motivation, we study a simple variant of the evolutionary prisoner's dilemma game entailing deceitful defectors and conditional cooperators that lifts the veil on the impact of such two-faced behavior. Defectors are able to hide their true intentions at a personal cost, while conditional cooperators are probabilistically successful at identifying defectors and act accordingly. By focusing on the evolutionary outcomes in structured populations, we observe a number of unexpected and counterintuitive phenomena. We show that deceitful behavior may fare better if it is costly, and that a higher success rate of identifying defectors does not necessarily favor cooperative behavior. These results are rooted in the spontaneous emergence of cycling dominance and spatia...

  15. HIDES spectroscopy of bright detached eclipsing binaries from the $Kepler$ field - I. Single-lined objects

    CERN Document Server

    Hełminiak, K G; Kambe, E; Kozłowski, S K; Sybilski, P; Ratajczak, M; Maehara, H; Konacki, M

    2016-01-01

    We present results of our spectroscopic observations of nine detached eclipsing binaries (DEBs), selected from the $Kepler$ Eclipsing Binary Catalog, that only show one set of spectral lines. Radial velocities (RVs) were calculated from the high resolution spectra obtained with the HIDES instrument, attached to the 1.88-m telescope at the Okayama Astrophysical Observatory, and from the public APOGEE archive. In our sample we found five single-lined binaries, with one component dominating the spectrum. The orbital and light curve solutions were found for four of them, and compared with isochrones, in order to estimate absolute physical parameters and evolutionary status of the components. For the fifth case we only update the orbital parameters, and estimate the properties of the unseen star. Two other systems show orbital motion with a period known from the eclipse timing variations (ETVs). For these we obtained parameters of outer orbits, by translating the ETVs to RVs of the centre of mass of the eclipsing ...

  16. High-Performance Region-of-Interest Image Error Concealment with Hiding Technique

    Directory of Open Access Journals (Sweden)

    Shih-Chang Hsia

    2010-01-01

    Full Text Available Recently region-of-interest (ROI based image coding is a popular topic. Since ROI area contains much more important information for an image, it must be prevented from error decoding while suffering from channel lost or unexpected attack. This paper presents an efficient error concealment method to recover ROI information with a hiding technique. Based on the progressive transformation, the low-frequency components of ROI are encoded to disperse its information into the high-frequency bank of original image. The capability of protection is carried out with extracting the ROI coefficients from the damaged image without increasing extra information. Simulation results show that the proposed method can efficiently reconstruct the ROI image when ROI bit-stream occurs errors, and the measurement of PSNR result outperforms the conventional error concealment techniques by 2 to 5 dB.

  17. An Improved FPGA Implementation of the Modified Hybrid Hiding Encryption Algorithm (MHHEA) for Data Communication Security

    CERN Document Server

    Farouk, Hala A

    2011-01-01

    The hybrid hiding encryption algorithm, as its name implies, embraces concepts from both steganography and cryptography. In this exertion, an improved micro-architecture Field Programmable Gate Array (FPGA) implementation of this algorithm is presented. This design overcomes the observed limitations of a previously-designed micro-architecture. These observed limitations are: no exploitation of the possibility of parallel bit replacement, and the fact that the input plaintext was encrypted serially, which caused a dependency between the throughput and the nature of the used secret key. This dependency can be viewed by some as vulnerability in the security of the implemented micro-architecture. The proposed modified micro-architecture is constructed using five basic modules. These modules are; the message cache, the message alignment module, the key cache, the comparator, and at last the encryption module. In this work, we provide comprehensive simulation and implementation results. These are: the timing diagra...

  18. Information Hiding in CSS : A Secure Scheme Text-Steganography using Public Key Cryptosystem

    CERN Document Server

    Kabetta, Herman; Suyoto,

    2012-01-01

    In many recent years, the programming world has been introduced about a new programming language for designing websites, it is CSS that can be be used together with HTML to develop a web interface. And now, these two programming languages as if inseparably from each other. As a client-side scripting, CSS is visible by all users as the original script, but it can not be granted changed. Website is a tool of information disseminator throughout the world, this is certainly can be used to a secret communication by using CSS as a message hider. This paper proposed a new scheme using web tools like CSS for hiding informations. This is a secret communication mechanism using text steganography techniques that is embedded messages on CSS files and is further encrypted using RSA as a public key cryptographic algorithm.

  19. Perfectly secure steganography: Hiding information in the quantum noise of a photograph

    Science.gov (United States)

    Sanguinetti, Bruno; Traverso, Giulia; Lavoie, Jonathan; Martin, Anthony; Zbinden, Hugo

    2016-01-01

    We show that it is possible to hide information perfectly within a photograph. The proposed protocol works by selecting each pixel value from two images that differ only by shot noise. Pixel values are never modified, but only selected, making the resulting stego image provably indistinguishable from an untampered image, and the protocol provably secure. We demonstrate that a perfect steganographic protocol is also a perfectly secure cryptographic protocol, and therefore has at least the same requirements: a truly random key as long as the message. In our system, we use a second image as the key, satisfying length requirements, and the randomness is provided by the naturally occurring quantum noise which is dominant in images taken with modern sensors. We conclude that, given a photograph, it is impossible to tell whether it contains any hidden information.

  20. Separable and Error-Free Reversible Data Hiding in Encrypted Image with High Payload

    Directory of Open Access Journals (Sweden)

    Zhaoxia Yin

    2014-01-01

    Full Text Available This paper proposes a separable reversible data-hiding scheme in encrypted image which offers high payload and error-free data extraction. The cover image is partitioned into nonoverlapping blocks and multigranularity encryption is applied to obtain the encrypted image. The data hider preprocesses the encrypted image and randomly selects two basic pixels in each block to estimate the block smoothness and indicate peak points. Additional data are embedded into blocks in the sorted order of block smoothness by using local histogram shifting under the guidance of the peak points. At the receiver side, image decryption and data extraction are separable and can be free to choose. Compared to previous approaches, the proposed method is simpler in calculation while offering better performance: larger payload, better embedding quality, and error-free data extraction, as well as image recovery.

  1. A GA-Based Approach to Hide Sensitive High Utility Itemsets

    Directory of Open Access Journals (Sweden)

    Chun-Wei Lin

    2014-01-01

    Full Text Available A GA-based privacy preserving utility mining method is proposed to find appropriate transactions to be inserted into the database for hiding sensitive high utility itemsets. It maintains the low information loss while providing information to the data demanders and protects the high-risk information in the database. A flexible evaluation function with three factors is designed in the proposed approach to evaluate whether the processed transactions are required to be inserted. Three different weights are, respectively, assigned to the three factors according to users. Moreover, the downward closure property and the prelarge concept are adopted in the proposed approach to reduce the cost of rescanning database, thus speeding up the evaluation process of chromosomes.

  2. Reversible Data Hiding In Encrypted Images by Reserving Room before Encryption

    Directory of Open Access Journals (Sweden)

    Harish G, Smitha Shekar B, Prajwal R, Sunil S Shetty

    2014-07-01

    Full Text Available Recently, more and more attention is paid to reversible data hiding (RDH in encrypted images, since it maintains the excellent property that the original cover can be losslessly recovered after embedded data is extracted while protecting the image content’s confidentiality. All previous methods embed data by reversibly vacating room from the encrypted images, which may subject to some errors on data extraction and/or image restoration. Here, a novel method is proposed so as to reserve room before encryption with a traditional RDH algorithm, and thus it is easy for the data hider to reversibly embed data in the encrypted image. The proposed method can achieve real reversibility, i.e., data extraction and image recovery are free of any error.

  3. Block Based Information Hiding using Cosine, Hartley, Walsh and Haar Wavelets

    Directory of Open Access Journals (Sweden)

    H. B. Ke kre

    2013-04-01

    Full Text Available Steganography is the art of hiding informationwithin other information in such a way that it ishard or even impossible to tell that it is there. Thereare many different carriers for steganography butthe most popular is digital images. Typically, themessage is embedded within another image knownas a cover image, by tweaking its properties. Theresulting output, known as astego-image isengineered such that it is a near identicalperceptual model of the cover image, but it will alsocontain the hiddenmessage.It is this stego-imagethat is sent between the sender and the receiver.Steganography is a science for invisiblecommunication and play vital role on the networksecurity.To improve the embedding capacity as wellas to have minimum distortion tocarrier media, we

  4. On the implementation of IP protection using biometrics based information hiding and firewall

    Science.gov (United States)

    Basu, Abhishek; Nandy, Kingshuk; Banerjee, Avishek; Giri, Supratick; Sarkar, Souvik; Sarkar, Subir Kumar

    2016-02-01

    System-on-chip-based design style creates a revolution in very large scale integration industry with design efficiency, operating speed and development time. To support this process, reuse and exchange of components are essential in electronic form called intellectual property (IP). This, however, increases the possibility of encroachment of IP of the design. So copyright protection of IP against piracy is the most important concern for IP vendors. The existing solutions for IP protection are still not secure enough with flexibility, cost, etc. This paper proposes an information-hiding-based solution for IP protection by embedding a biometric copyright information and firewall inside an IP in the form of a finite state machine with unique configuration. The scheme first introduces biometric signature-based copyright as ownership proof. Second, firewall interrupts the normal functionality of IP at the end of the user time period. The experimental outcomes of field-programmable-gate-array implementation illustrate the efficiency of the proposed method.

  5. Optical image hiding based on dual-channel simultaneous phase-shifting interferometry and compressive sensing

    Science.gov (United States)

    Li, Jiaosheng; Zhong, Liyun; Zhang, Qinnan; Zhou, Yunfei; Xiong, Jiaxiang; Tian, Jindong; Lu, Xiaoxu

    2017-01-01

    We propose an optical image hiding method based on dual-channel simultaneous phase-shifting interferometry (DCSPSI) and compressive sensing (CS) in all-optical domain. In the DCSPSI architecture, a secret image is firstly embedded in the host image without destroying the original host's form, and a pair of interferograms with the phase shifts of π/2 is simultaneously generated by the polarization components and captured by two CCDs. Then, the holograms are further compressed sampling to the less data by CS. The proposed strategy will provide a useful solution for the real-time optical image security transmission and largely reducing data volume of interferogram. The experimental result demonstrates the validity and feasibility of the proposed method.

  6. A New Method for Text Hiding in the Image by Using LSB

    Directory of Open Access Journals (Sweden)

    Reza tavoli

    2016-04-01

    Full Text Available an important topic in the exchange of confidential messages over the internet is the security of information conveyance. For instance, the producers and consumers of digital products are keen to know that their products are authentic and can be differentiated from those that are invalid. The science of encryption is the art of embedding data in audio files, images, videos or content in a way that would meet the above security needs. Steganography is a branch of data-hiding science which aims to reach a desirable level of security in the exchange of private military and commercial data which is not clear. These approaches can be used as complementary methods of encryption in the exchange of private data.

  7. Alien invasions and the game of hide and seek in Patagonia.

    Directory of Open Access Journals (Sweden)

    Martin Lindegren

    Full Text Available The introduction, establishment and spread of alien species is a major threat to biodiversity and the provision of ecosystem services for human wellbeing. In order to reduce further loss of biodiversity and maintain productive and sustainable ecosystems, understanding the ecological mechanisms underlying species invasions and avoiding potentially harmful effects on native communities is urgently needed, but largely lacking. We here demonstrate, by means of hydroacoustics and advanced spatial modelling, how native fish species as a result of previous exposure to native predators may successfully respond to invasive novel predators through a complicated game of hide and seek, minimizing spatio-temporal overlap with predators, and potentially facilitating coexistence between native prey species (Galaxiids and introduced novel predators (Salmonids in a deep Andean lake, Patagonia.

  8. Study of information hiding algorithm based on GHM and color transfer theory

    Institute of Scientific and Technical Information of China (English)

    REN Shuai; MU De-jun; ZHANG Tao; HU Wei

    2009-01-01

    Taking the feature that the energy of the image would gather and spread on four components (LL2, LH2, HL2 and HH2) in the sub-image atfer first-order GHM multi-wavelet-transform. And by using the color control ability oflαβ color space in color transfer theory (CTT), an information hiding algorithm based on GHM-CTT is proposed. In this way, the robust parameters are embedded in the LL2, the hidden information is set in LH2 and HL2 with RAID4, and fragile sign is set in HH2. The consistence between the embedded data bits' order and the embedded code of the sub-image is improved by using the chaotic mapping and the genetic algorithm. Experimental results indicate that the GHM-CTT can increase the imperceptibility by 15.72% averagely and robustness by 18.89% at least.

  9. Modelling the Crust beneath the Kashmir valley in Northwestern Himalaya

    Science.gov (United States)

    Mir, R. R.; Parvez, I. A.; Gaur, V. K.; A.; Chandra, R.; Romshoo, S. A.

    2015-12-01

    We investigate the crustal structure beneath five broadband seismic stations in the NW-SE trendingoval shaped Kashmir valley sandwiched between the Zanskar and the Pir Panjal ranges of thenorthwestern Himalaya. Three of these sites were located along the southwestern edge of the valley andthe other two adjoined the southeastern. Receiver Functions (RFs) at these sites were calculated usingthe iterative time domain deconvolution method and jointly inverted with surface wave dispersiondata to estimate the shear wave velocity structure beneath each station. To further test the results ofinversion, we applied forward modelling by dividing the crust beneath each station into 4-6homogeneous, isotropic layers. Moho depths were separately calculated at different piercing pointsfrom the inversion of only a few stacked receiver functions of high quality around each piercing point.These uncertainties were further reduced to ±2 km by trial forward modelling as Moho depths werevaried over a range of ±6 km in steps of 2 km and the synthetic receiver functions matched with theinverted ones. The final values were also found to be close to those independently estimated using theH-K stacks. The Moho depths on the eastern edge of the valley and at piercing points in itssouthwestern half are close to 55 km, but increase to about 58 km on the eastern edge, suggesting thathere, as in the central and Nepal Himalaya, the Indian plate dips northeastwards beneath the Himalaya.We also calculated the Vp/Vs ratio beneath these 5 stations which were found to lie between 1.7 and1.76, yielding a Poisson's ratio of ~0.25 which is characteristic of a felsic composition.

  10. Crustal structure beneath northeast India inferred from receiver function modeling

    Science.gov (United States)

    Borah, Kajaljyoti; Bora, Dipok K.; Goyal, Ayush; Kumar, Raju

    2016-09-01

    We estimated crustal shear velocity structure beneath ten broadband seismic stations of northeast India, by using H-Vp/Vs stacking method and a non-linear direct search approach, Neighbourhood Algorithm (NA) technique followed by joint inversion of Rayleigh wave group velocity and receiver function, calculated from teleseismic earthquakes data. Results show significant variations of thickness, shear velocities (Vs) and Vp/Vs ratio in the crust of the study region. The inverted shear wave velocity models show crustal thickness variations of 32-36 km in Shillong Plateau (North), 36-40 in Assam Valley and ∼44 km in Lesser Himalaya (South). Average Vp/Vs ratio in Shillong Plateau is less (1.73-1.77) compared to Assam Valley and Lesser Himalaya (∼1.80). Average crustal shear velocity beneath the study region varies from 3.4 to 3.5 km/s. Sediment structure beneath Shillong Plateau and Assam Valley shows 1-2 km thick sediment layer with low Vs (2.5-2.9 km/s) and high Vp/Vs ratio (1.8-2.1), while it is observed to be of greater thickness (4 km) with similar Vs and high Vp/Vs (∼2.5) in RUP (Lesser Himalaya). Both Shillong Plateau and Assam Valley show thick upper and middle crust (10-20 km), and thin (4-9 km) lower crust. Average Vp/Vs ratio in Assam Valley and Shillong Plateau suggest that the crust is felsic-to-intermediate and intermediate-to-mafic beneath Shillong Plateau and Assam Valley, respectively. Results show that lower crust rocks beneath the Shillong Plateau and Assam Valley lies between mafic granulite and mafic garnet granulite.

  11. Three-dimensional shallow velocity structure beneath Taal Volcano, Philippines

    Science.gov (United States)

    You, Shuei-Huei; Konstantinou, Konstantinos I.; Gung, Yuancheng; Lin, Cheng-Horng

    2017-07-01

    Based on its numerous historical explosive eruptions and high potential hazards to nearby population of millions, Taal Volcano is one of the most dangerous "Decade Volcanoes" in the world. To provide better investigation on local seismicity and seismic structure beneath Taal Volcano, we deployed a temporary seismic network consisting of eight stations from March 2008 to March 2010. In the preliminary data processing stage, three periods showing linear time-drifting of internal clock were clearly identified from noise-derived empirical Green's functions. The time-drifting errors were corrected prior to further data analyses. By using VELEST, 2274 local earthquakes were manually picked and located. Two major earthquake groups are noticed, with one lying beneath the western shore of Taal Lake showing a linear feature, and the other spreading around the eastern flank of Taal Volcano Island at shallower depths. We performed seismic tomography to image the 3D structure beneath Taal Volcano using the LOTOS algorithm. Some interesting features are revealed from the tomographic results, including a solidified magma conduit below the northwestern corner of Taal Volcano Island, indicated by high Vp, Vs, and low Vp/Vs ratio, and a large potential hydrothermal reservoir beneath the center of Taal Volcano Island, suggested by low Vs and high Vp/Vs ratio. Furthermore, combining earthquake distributions and tomographic images, we suggest potential existence of a hydrothermal reservoir beneath the southwestern corner of Taal Lake, and a fluid conduit extending to the northwest. These seismic features have never been proposed in previous studies, implying that new hydrothermal activity might be formed in places away from the historical craters on Taal Volcano Island.

  12. The elastic properties of the lithosphere beneath Scotian basin

    Science.gov (United States)

    Zheng, Ying; Arkani-Hamed, Jafar

    2002-02-01

    To assess the possibility that the North Atlantic Ocean may subduct at Scotian basin east of Canada, we investigate the present compensation state of this deep basin. A Fourier domain analysis of the bathymetry, depth to basement and observed gravity anomalies over the oceanic area east of Nova Scotia indicates that the basin is not isostatically compensated. Moreover, the analysis emphasizes that in addition to the sediments, density perturbations exist beneath the basin. The load produced by the sediments and these density perturbations must have been supported by the lithosphere. We simulate the flexure of the lithosphere under this load by that of a thin elastic plate overlying an inviscid interior. It is shown that a plate with a uniform rigidity does not adequately represent the lithosphere beneath the basin as well as the oceanic lithosphere far from the basin, rather the rigidity of the lithosphere directly beneath the basin is about one to two orders of magnitude smaller than elsewhere. We relate this weakening to the thermal blanketing effects of the thick sediments and the fact that the lithosphere has a temperature-dependent rheology. We suggest that this weak zone would have a controlling effect on the reactivation of normal faults at the hinge zone of the basin, that were formed during the break-up of Africa and North America and were locked in the early stages after the break-up. The weak zone would facilitate reactivation of the faults if tensional stresses were produced by possible reorientation of the spreading direction of the North Atlantic Ocean in the future. The reactivation of the faults would create a free boundary condition at the hinge zone, allowing further bending of the lithosphere beneath the basin and juxtaposition of this lithosphere to the mantle beneath the continent. This may provide a favorable situation for initiation of slow subduction due to subsequent compressional forces.

  13. Selective Jamming Attack Prevention Based on Packet Hiding Methods and Wormholes

    Directory of Open Access Journals (Sweden)

    Divya Ann Luke

    2014-06-01

    Full Text Available The wireless networks are more sensitive to the Denial-of-Service (DoS attacks. The existing system is based on Spread Spectrum (SS. This technique mainly focuses on an external threat model. In wireless network the communications between nodes take place through broadcast communication. That is why, if an attacker present within the network can easily eavesdrop the message sent by any node. The main attack present in the wireless network is the selective jamming attack. This type of attack mainly focuses a single node termed as target node. Attacker always tries to block the message sent by the target node. This leads to the Denial-of-Service attack. We are proposing a new method to prevent the selective jamming attack in an internalthreat model. A wormhole is used, which will generate an alarm to indicate the presence of jammer and sent IP address of jammer node to all other nodes in the network. Using a method called packet hiding, we can send message through the network even though a jammer is present. This method is based on the technique called Strong Hiding Commitment Scheme (SHCS. Here, the access point in a network region becomes the wormhole whenever it finds out any node that violates the rules in a particular network region. That node is then considered as a jammer node. The wormhole send s IP address of jammer to all other nodes. Wormhole then prevents the jamming activity of the jammer by encrypting the source ID of message along with the message packet.So that the jammer is unable to identify its target node and the source can forward its message safely through jammer node itself

  14. Adaptive and non-adaptive data hiding methods for grayscale images based on modulus function

    Directory of Open Access Journals (Sweden)

    Najme Maleki

    2014-07-01

    Full Text Available This paper presents two adaptive and non-adaptive data hiding methods for grayscale images based on modulus function. Our adaptive scheme is based on the concept of human vision sensitivity, so the pixels in edge areas than to smooth areas can tolerate much more changes without making visible distortion for human eyes. In our adaptive scheme, the average differencing value of four neighborhood pixels into a block via a threshold secret key determines whether current block is located in edge or smooth area. Pixels in the edge areas are embedded by Q-bit of secret data with a larger value of Q than that of pixels placed in smooth areas. Also in this scholar, we represent one non-adaptive data hiding algorithm. Our non-adaptive scheme, via an error reduction procedure, produces a high visual quality for stego-image. The proposed schemes present several advantages. 1-of aspects the embedding capacity and visual quality of stego-image are scalable. In other words, the embedding rate as well as the image quality can be scaled for practical applications 2-the high embedding capacity with minimal visual distortion can be achieved, 3-our methods require little memory space for secret data embedding and extracting phases, 4-secret keys have used to protect of the embedded secret data. Thus, level of security is high, 5-the problem of overflow or underflow does not occur. Experimental results indicated that the proposed adaptive scheme significantly is superior to the currently existing scheme, in terms of stego-image visual quality, embedding capacity and level of security and also our non-adaptive method is better than other non-adaptive methods, in view of stego-image quality. Results show which our adaptive algorithm can resist against the RS steganalysis attack.

  15. An Improved Quantum Information Hiding Protocol Based on Entanglement Swapping of χ-type Quantum States

    Science.gov (United States)

    Xu, Shu-Jiang; Chen, Xiu-Bo; Wang, Lian-Hai; Ding, Qing-Yan; Zhang, Shu-Hui

    2016-06-01

    In 2011, Qu et al. proposed a quantum information hiding protocol based on the entanglement swapping of χ-type quantum states. Because a χ-type state can be described by the 4-particle cat states which have good symmetry, the possible output results of the entanglement swapping between a given χ-type state and all of the 16 χ-type states are divided into 8 groups instead of 16 groups of different results when the global phase is not considered. So it is difficult to read out the secret messages since each result occurs twice in each line (column) of the secret messages encoding rule for the original protocol. In fact, a 3-bit instead of a 4-bit secret message can be encoded by performing two unitary transformations on 2 particles of a χ-type quantum state in the original protocol. To overcome this defect, we propose an improved quantum information hiding protocol based on the general term formulas of the entanglement swapping among χ-type states. Supported by the National Natural Science Foundation of China under Grant Nos. 61572297, 61303199, 61272514, and 61373131, the Shandong Provincial Natural Science Foundation of China under Grant Nos. ZR2013FM025, ZR2013FQ001, ZR2014FM003, and ZY2015YL018, the Shandong Provincial Outstanding Research Award Fund for Young Scientists of China under Grant Nos. BS2015DX006 and BS2014DX007, the National Development Foundation for Cryptological Research, China under Grant No. MMJJ201401012, the Priority Academic Program Development of Jiangsu Higher Education Institutions and Jiangsu Collaborative Innovation Center on Atmospheric Environment and Equipment Technology Funds, and the Shandong Academy of Sciences Youth Fund Project, China under Grant Nos. 2015QN003 and 2013QN007

  16. Hiding a Heavy Higgs Boson at the 7 TeV LHC

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Yang; Fan, JiJi; Hewett, JoAnne L.

    2012-03-20

    A heavy Standard Model Higgs boson is not only disfavored by electroweak precision observables but is also excluded by direct searches at the 7 TeV LHC for a wide range of masses. Here, we examine scenarios where a heavy Higgs boson can be made consistent with both the indirect constraints and the direct null searches by adding only one new particle beyond the Standard Model. This new particle should be a weak multiplet in order to have additional contributions to the oblique parameters. If it is a color singlet, we find that a heavy Higgs with an intermediate mass of 200-300 GeV can decay into the new states, suppressing the branching ratios for the standard model modes, and thus hiding a heavy Higgs at the LHC. If the new particle is also charged under QCD, the Higgs production cross section from gluon fusion can be reduced significantly due to the new colored particle one-loop contribution. Current collider constraints on the new particles allow for viable parameter space to exist in order to hide a heavy Higgs boson. We categorize the general signatures of these new particles, identify favored regions of their parameter space and point out that discovering or excluding them at the LHC can provide important indirect information for a heavy Higgs. Finally, for a very heavy Higgs boson, beyond the search limit at the 7 TeV LHC, we discuss three additional scenarios where models would be consistent with electroweak precision tests: including an additional vector-like fermion mixing with the top quark, adding another U(1) gauge boson and modifying triple-gauge boson couplings.

  17. 通信信息隐藏技术研究%A Research on Communication Information Hiding Technologies

    Institute of Scientific and Technical Information of China (English)

    张松; 冯祺

    2016-01-01

    网络的技术的迅速发展使得通信信息的传输变得更加快捷、方便,与此同时,也为攻击者截获通信信息带来了便利,通信的安全和隐蔽成为一个亟需解决的问题。信息隐藏技术为保证通信的隐蔽性提供了一种新的思路。论文对信息隐藏技术进行分类介绍,给出了信息隐藏技术的模型和基本特征,并分析了信息隐藏技术与隐藏分析技术和密码学之间的关系,最后给出了总结与展望。%The rapid development of network technology enables the transmission of communication information to be ‐come faster and more convenient ,at the same time ,it also makes it easier for attackers to intercept communication informa‐tion .Security and covert communication has become an urgent problem ,information hiding technology provides a new way of thinking to ensure the covert communication .This paper describes the classification of information hiding technology ,and gives the model and the basic characteristics of information hiding ,and analyzes the relationship between information hiding and steganalysis as well as the relationship between information hiding and cryptography ,finally ,gives the summary and outlook future development .

  18. The elusive lithosphere-asthenosphere boundary (LAB) beneath cratons

    Science.gov (United States)

    Eaton, David W.; Darbyshire, Fiona; Evans, Rob L.; Grütter, Herman; Jones, Alan G.; Yuan, Xiaohui

    2009-04-01

    The lithosphere-asthenosphere boundary (LAB) is a first-order structural discontinuity that accommodates differential motion between tectonic plates and the underlying mantle. Although it is the most extensive type of plate boundary on the planet, its definitive detection, especially beneath cratons, is proving elusive. Different proxies are used to demarcate the LAB, depending on the nature of the measurement. Here we compare interpretations of the LAB beneath three well studied Archean regions: the Kaapvaal craton, the Slave craton and the Fennoscandian Shield. For each location, xenolith and xenocryst thermobarometry define a mantle stratigraphy, as well as a steady-state conductive geotherm that constrains the minimum pressure (depth) of the base of the thermal boundary layer (TBL) to 45-65 kbar (170-245 km). High-temperature xenoliths from northern Lesotho record Fe-, Ca- and Ti-enrichment, grain-size reduction and globally unique supra-adiabatic temperatures at 53-61 kbar (200-230 km depth), all interpreted to result from efficient advection of asthenosphere-derived melts and heat into the TBL. Using a recently compiled suite of olivine creep parameters together with published geotherms, we show that beneath cratons the probable deformation mechanism near the LAB is dislocation creep, consistent with widely observed seismic and electrical anisotropy fabrics. If the LAB is dry, it is probably diffuse (> 50 km thick) and high levels of shear stress (> 2 MPa or > 20 bar) are required to accommodate plate motion. If the LAB is wet, lower shear stress is required to accommodate plate motion and the boundary may be relatively sharp (≤ 20 km thick). The seismic LAB beneath cratons is typically regarded as the base of a high-velocity mantle lid, although some workers infer its location based on a distinct change in seismic anisotropy. Surface-wave inversion studies provide depth-constrained velocity models, but are relatively insensitive to the sharpness of the LAB

  19. Lithospheric thinning beneath rifted regions of Southern California.

    Science.gov (United States)

    Lekic, Vedran; French, Scott W; Fischer, Karen M

    2011-11-11

    The stretching and break-up of tectonic plates by rifting control the evolution of continents and oceans, but the processes by which lithosphere deforms and accommodates strain during rifting remain enigmatic. Using scattering of teleseismic shear waves beneath rifted zones and adjacent areas in Southern California, we resolve the lithosphere-asthenosphere boundary and lithospheric thickness variations to directly constrain this deformation. Substantial and laterally abrupt lithospheric thinning beneath rifted regions suggests efficient strain localization. In the Salton Trough, either the mantle lithosphere has experienced more thinning than the crust, or large volumes of new lithosphere have been created. Lack of a systematic offset between surface and deep lithospheric deformation rules out simple shear along throughgoing unidirectional shallow-dipping shear zones, but is consistent with symmetric extension of the lithosphere.

  20. On Irrotational Flows Beneath Periodic Traveling Equatorial Waves

    Science.gov (United States)

    Quirchmayr, Ronald

    2016-08-01

    We discuss some aspects of the velocity field and particle trajectories beneath periodic traveling equatorial surface waves over a flat bed in a flow with uniform underlying currents. The system under study consists of the governing equations for equatorial ocean waves within a non-inertial frame of reference, where Euler's equation of motion has to be suitably adjusted, in order to account for the influence of the earth's rotation.

  1. Detection of Cracks in Aluminum Structure Beneath Inconel Repair Bushings

    Science.gov (United States)

    2008-04-01

    conductivity (i.e. Inconel 718 ) – Primary challenge then becomes detecting the weak eddy current field in the structure beyond the bushing wall...was able to be selected with inspectability as a goal. – Inconel 718 • low permeability (~μ0) • low conductivity (< 2% IACS) • Combined with...Detection of Cracks in Aluminum Structure beneath Inconel Repair Bushings Mr. Kenneth J. LaCivita (USAF) AFRL/RXSA Air Force Research Laboratory

  2. Lithospheric instability beneath the Transverse Ranges of California

    OpenAIRE

    Houseman, Gregory A.; Neil, Emily A.; Kohler, Monica D.

    2000-01-01

    Recent high-resolution seismic experiments reveal that the crust beneath the San Gabriel Mountains portion of the Transverse Ranges thickens by 10–15 km (contrary to earlier studies). Associated with the Transverse Ranges, there is an anomalous ridge of seismically fast upper mantle material extending at least 200 km into the mantle. This high-velocity anomaly has previously been interpreted as a lithospheric downwelling. Both lithospheric downwelling and crustal thickening are associated wit...

  3. On Irrotational Flows Beneath Periodic Traveling Equatorial Waves

    Science.gov (United States)

    Quirchmayr, Ronald

    2017-06-01

    We discuss some aspects of the velocity field and particle trajectories beneath periodic traveling equatorial surface waves over a flat bed in a flow with uniform underlying currents. The system under study consists of the governing equations for equatorial ocean waves within a non-inertial frame of reference, where Euler's equation of motion has to be suitably adjusted, in order to account for the influence of the earth's rotation.

  4. Kelvin-Helmholtz wave generation beneath hovercraft skirts

    Science.gov (United States)

    Sullivan, P. A.; Walsh, C.; Hinchey, M. J.

    1993-05-01

    When a hovercraft is hovering over water, the air flow beneath its skirts can interact with the water surface and generate waves. These, in turn, can cause the hovercraft to undergo violent self-excited heave motions. This note shows that the wave generation is due to the classical Kelvin-Helmholtz mechanism where, beyond a certain air flow rate, small waves at the air water interface extract energy from the air stream and grow.

  5. The Dumbarton Oaks Tlazolteotl: looking beneath the surface

    OpenAIRE

    MacLaren Walsh, Jane

    2014-01-01

    The Dumbarton Oaks Tlazolteotl: looking beneath the surface. Some of the earliest and most revered pre-Columbian artifacts in the world’s major museum and private collections were collected prior to the advent of systematic, scientific archaeological excavation, and have little or no reliable provenience data. They have consistently posed problems for researchers due to anomalies of theme, material, size, technical virtuosity and iconography. This paper offers a historical and scientific appr...

  6. New interpretation of the deep mantle structure beneath eastern China

    Science.gov (United States)

    Ma, Pengfei; Liu, Shaofeng; Lin, Chengfa; Yao, Xiang

    2016-04-01

    Recent study of high resolution seismic tomography presents a large mass of high velocity abnormality beneath eastern China near the phase change depth, expanding more than 1600km-wide in East-west cross-section across the North China plate. This structure high is generally believed to be the subducted slab of Pacific plate beneath the Eurasia continent, while its origin and dynamic effect on the Cenozoic tectonic evolution of eastern China remain to be controversial. We developed a subduction-driven geodynamic mantle convection model that honors a set of global plate reconstruction data since 230Ma to help understand the formation and evolution of mantle structure beneath eastern China. The assimilation of plate kinematics, continuous evolving plate margin, asymmetric subduction zone, and paleo seafloor age data enables the spatial and temporal consistency between the geologic data and the mantle convection model, and guarantees the conservation of the buoyancy flux across the lithosphere and subducted slabs. Our model achieved a first order approximation between predictions and the observed data. Interestingly, the model suggests that the slab material stagnated above discontinuity didn't form until 15Ma, much later than previous expected, and the fast abnormality in the mid-mantle further west in the tomographic image is interpreted to be the remnants of the Mesozoic Izanagi subduction. Moreover, detailed analysis suggests that the accelerated subduction of Philippine Sea plate beneath Eurasia plate along the Ryukyu Trench and Nankai Trough since 15Ma may largely contribute to extending feature above 670km discontinuity. The long distance expansion of the slab material in the East-west direction may be an illusion caused by the approximate spatial perpendicularity between the cross-section and the subduction direction of the Philippine Sea plate. Our model emphasizes the necessity of the re-examination on the geophysical observation and its tectonic and

  7. Lithospheric radial anisotropy beneath the Gulf of Mexico

    Science.gov (United States)

    Chu, Risheng; Ko, Justin Yen-Ting; Wei, Shengji; Zhan, Zhongwen; Helmberger, Don

    2017-05-01

    The Lithosphere-Asthenosphere Boundary (LAB), where a layer of low viscosity asthenosphere decouples with the upper plate motion, plays an essential role in plate tectonics. Most dynamic modeling assumes that the shear velocity can be used as a surrogate for viscosity which provides key information about mantle flow. Here, we derive a shear velocity model for the LAB structure beneath the Gulf of Mexico allowing a detailed comparison with that beneath the Pacific (PAC) and Atlantic (ATL). Our study takes advantage of the USArray data from the March 25th, 2013 Guatemala earthquake at a depth of 200 km. Such data is unique in that we can observe a direct upward traveling lid arrival which remains the first arrival ahead of the triplications beyond 18°. This extra feature in conjunction with upper-mantle triplication sampling allows good depth control of the LAB and a new upper-mantle seismic model ATM, a modification of ATL, to be developed. ATM has a prominent low velocity zone similar to the structure beneath the western Atlantic. The model contains strong radial anisotropy in the lid where VSH is about 6% faster than VSV. This anisotropic feature ends at the bottom of the lithosphere at about the depth of 175 km in contrast to the Pacific where it extends to over 300 km. Another important feature of ATM is the weaker velocity gradient from the depth of 175 to 350 km compared to Pacific models, which may be related to differences in mantle flow.

  8. Why are there few seedlings beneath the myrmecophyte Triplaris americana?

    Science.gov (United States)

    Larrea-Alcázar, Daniel M.; Simonetti, Javier A.

    2007-07-01

    We compared the relative importance of chemical alellopathy, pruning behaviour of resident ants and other non-related agents to ant-plant mutualism for seedling establishment beneath Triplaris americana L. (Polygonaceae), a myrmecophyte plant. We also included a preliminary analysis of effects of fragmentation on these ecological processes. Seeds and seedlings of Theobroma cacao L. (Sterculiaceae) were used as the target species in all experiments. Leaf-tissue extracts of the myrmecophyte plant did not inhibit germination of cacao seeds. Resident Pseudomyrmex triplarinus Weddell (Pseudomyrmecinae) ants did not remove seeds under the canopy of their host plants. The main seed consumer was the leaf-cutting ant Atta sexdens L. (Myrmicinae). Leaves of cacao seedlings were partially or totally pruned by Pseudomyrmex ants mainly in forest fragments studied. We offer evidence pointing to the possibility that the absence of seedlings beneath Triplaris may result from effects of both ant species. We discuss the benefits of pruning behaviour for the resident ant colony and the effects of ant-ant interactions on seedling establishment beneath this ant-plant system.

  9. Crustal structure beneath the southern Korean Peninsula from local earthquakes

    Science.gov (United States)

    Kim, Kwang-Hee; Park, Jung-Ho; Park, Yongcheol; Hao, Tian-Yao; Kim, Han-Joon

    2017-02-01

    The three-dimensional subsurface structure beneath the southern Korean Peninsula is poorly known, even though such information could be key in verifying or rejecting several competing models of the tectonic evolution of East Asia. We constructed a three-dimensional velocity model of the upper crust beneath the southern Korean Peninsula using 19,935 P-wave arrivals from 747 earthquakes recorded by high-density local seismic networks. Results show significant lateral and vertical variations: velocity increases from northwest to southeast at shallow depths, and significant velocity variations are observed across the South Korea Tectonic Line between the Okcheon Fold Belt and the Youngnam Massif. Collision between the North China and South China blocks during the Early Cretaceous might have caused extensive deformation and the observed negative velocity anomalies in the region. The results of the tomographic inversion, combined with the findings of previous studies of Bouguer and isostatic gravity anomalies, indicate the presence of high-density material in the upper and middle crust beneath the Gyeongsang Basin in the southeastern Korean Peninsula. Although our results partially support the indentation tectonic model, it is still premature to discard other tectonic evolution models because our study only covers the southern half of the peninsula.

  10. Descending lithosphere slab beneath the Northwest Dinarides from teleseismic tomography

    Science.gov (United States)

    Šumanovac, Franjo; Dudjak, Darko

    2016-12-01

    The area of study covers the marginal zone between the Adriatic microplate (African plate) and the Pannonian segment (Eurasian plate). We present a tomography model for this area, with special emphasis on the northwest Dinarides. A dense distribution of temporary seismic stations in the area of the Northern Dinarides along with permanent seismic stations located in the area, allowed us to construct this P-wave tomographic model. We assembled our travel-time dataset based on 26 seismic stations were used to collect the dataset. Teleseismic events were recorded for a period of 18 months and a set of 76 distant earthquakes were used to calculate the P-wave travel-time residuals. We calculated relative rather than absolute arrival-time residuals in the inversion to obtain depths of 0-400 km. We imaged a pronounced fast velocity anomaly below the NW Dinarides which directly indicates a lithosphere slab downgoing beneath the Dinarides. This fast anomaly extends towards the NW direction to at least 250 km depth, and we interpreted it as a descending lithosphere slab. The thrusting of the Adriatic microplate may be brought about by sub-lithosphere rising movement beneath the Pannonian region, along with a push from African plate. In our interpretation, the Adriatic lower lithosphere has been detached from the crust, and steeply sinks beneath the Dinarides. A lithosphere model of the contact between the Adriatic microplate and Pannonian tectonic segment was constructed based on the tomographic velocity model and results of previous crustal studies.

  11. What lies beneath the Cerro Prieto geothermal field?

    Energy Technology Data Exchange (ETDEWEB)

    Elders, W.A.; Williams, A.E.; Biehler, S. [Univ. of California, Riverside, CA (United States)

    1997-12-31

    Although the Cerro Prieto geothermal reservoir is one of the world`s largest geothermal developments, conflicting ideas persist about the basement beneath it. The current plan to drill a 6 km deep exploratory well in the eastern part of the field has brought this controversy into sharper focus. This paper discusses criteria which any model of what lies beneath the reservoir must meet, in terms of regional tectonics and geophysics, of the metamorphic and igneous rocks thus far encountered in drilling, and of models of possible heat sources and coupling between the hydrothermal and magmatic systems. Our analysis confirms the interpretation that the crystalline basement beneath the sediments, rather than being granitic, is oceanic in character, resembling an ophiolite complex. The heat source is most likely a cooling gabbroic intrusion, several kilometers in diameter, overlain by a sheeted dike swarm. A 6 km deep bore-hole centered over such an intrusion would not only be one of the world`s deepest geothermal wells but could also be one of the hottest.

  12. Phenotypic mixing and hiding may contribute to memory in viral quasispecies

    Directory of Open Access Journals (Sweden)

    Novella Isabel S

    2003-06-01

    Full Text Available Abstract Background In a number of recent experiments with food-and-mouth disease virus, a deleterious mutant, RED, was found to avoid extinction and remain in the population for long periods of time. Since RED characterizes the past evolutionary history of the population, this observation was called quasispecies memory. While the quasispecies theory predicts the existence of these memory genomes, there is a disagreement between the expected and observed mutant frequency values. Therefore, the origin of quasispecies memory is not fully understood. Results We propose and analyze a simple model of complementation between the wild type virus and a mutant that has an impaired ability of cell entry, the likely cause of fitness differences between wild type and RED mutants. The mutant will go extinct unless it is recreated from the wild type through mutations. However, under phenotypic mixing-and-hiding as a mechanism of complementation, the time to extinction in the absence of mutations increases with increasing multiplicity of infection (m.o.i.. If the RED mutant is constantly recreated by mutations, then its frequency at equilibrium under selection-mutation balance also increases with increasing m.o.i. At high m.o.i., a large fraction of mutant genomes are encapsidated with wild-type protein, which enables them to infect cells as efficiently as the wild type virions, and thus increases their fitness to the wild-type level. Moreover, even at low m.o.i. the equilibrium frequency of the mutant is higher than predicted by the standard quasispecies model, because a fraction of mutant virions generated from wild-type parents will also be encapsidated by wild-type protein. Conclusions Our model predicts that phenotypic hiding will strongly influence the population dynamics of viruses, particularly at high m.o.i., and will also have important effects on the mutation-selection balance at low m.o.i. The delay in mutant extinction and increase in mutant

  13. Hiding Secret Text in Quick Response Code and Transforming the Position of the Secret Data using Rotation Transformation

    Directory of Open Access Journals (Sweden)

    V. Ramya

    2014-05-01

    Full Text Available In order to provide high security and safety in the field of information hiding, this study proposes a novel technology using Steganography. An exotic steganographic algorithm, is used in this study, which Hides the secret text data in a 2D plane (Here, in our case let the 2D plane be the QR code, after encryption and the position of the secret data will be changed using rotation transformation. The proposed algorithm has been tested under various imperceptibility characters such as PSNR, MSE, Human Vision Quality Metrics and Histograms are compared to both cover image and the stego image. This novel algorithm shows Lower MSE, higher PSNR values and it is evident that the proposed algorithm is robust to JPEG attacks.

  14. Pre-slaughter, slaughter and post-slaughter defects of skins and hides at the Sheba Tannery and Leather Industry, Tigray region, northern Ethiopia

    Directory of Open Access Journals (Sweden)

    Tesfay Kahsay

    2015-02-01

    Full Text Available Skins and hides are perishable resources that can be damaged by parasitic diseases and human error, which result in downgrading or rejection. This study was conducted to identify defect types and to determine their prevalence in pickled sheep and wet blue goat skins and wet blue hides. Each selected skin or hide was examined for defects in natural light and the defects were graded according to established quality criteria in Ethiopian standard manuals. Major defects were captured by digital photography. The major pre-slaughter defects included scratches (64.2%, cockle (ekek (32.8%, wounds or scars (12.6%, lesions from pox or lumpy skin disease (6.1%, poor substance (5%, branding marks (2.3% and tick bites (1.5%. The presence of grain scratches in wet blue hides (76.3% was significantly higher than in pickled sheep (67.2% and wet blue goat (59.1% skins. The major slaughter defects included flay cuts or scores, holes, poor pattern and vein marks, with a higher occurrence in wet blue goat skins (28.7%; P < 0.001 than in wet blue hides (22.8% and pickled sheep skins (11.1%. The most prevalent postslaughter defects were grain cracks (14.9%, hide beetle damage (8%, damage caused by heat or putrefaction (3.7% and machine-induced defects (0.5%. Grain cracks (27.04% and hide beetle damage (13.9% in wet blue goat skins were significantly more common than in wet blue hides and pickled sheep skins. These defects cause depreciation in the value of the hides and skins. Statistically significant (P < 0.001 higher rejection rates were recorded for wet blue hides (82.9% than for pickled sheep skins (18.3% and wet blue goat skins (8.5%. Improved animal health service delivery, effective disease control strategies and strong collaboration between stakeholders are suggested to enhance the quality of skins and hides.

  15. Asymmetric information hiding and noise-free recovery based on rotating analyzer ellipsometry and quick-response code.

    Science.gov (United States)

    Lin, Chao; Shen, Xueju; Wang, Zhisong

    2014-08-01

    We report an asymmetric optical information hiding method based on a rotating analyzer ellipsometry technique. This asymmetric hiding architecture not only avoids the interception of keys during transmission or distribution but also makes the cyphertext more inconspicuous for attackers. A new kind of one-way optical trapdoor function is constructed based on the fact that the state of polarization (SOP) of elliptical polarized light cannot be recovered with only the knowledge of intensity captured after passing through a linear polarizer. Meanwhile, the SOP of a polarization ellipse could be calculated by rotating the polarizer to record two scenes of intensity after it. Introduction of a quick response code as a container leads to noise-free recovery for original information and enhances practicality of the proposed cryptosystem with versatile key sensitivity and fault tolerance capability. Numerical simulation results that support theoretical analysis are presented. Analysis on the relationship between hiding effect or quality of decryption and parameters of the algorithm also is provided.

  16. A place to hide in the home-cage decreases yolk androgen levels and offspring emotional reactivity in Japanese quail.

    Directory of Open Access Journals (Sweden)

    Vanessa Guesdon

    Full Text Available An animal's emotional responses are the result of its cognitive appraisal of a situation. This appraisal is notably influenced by the possibility of an individual to exert control over an aversive event. Although the fact that environment controllability decreases emotional responses in animals is well established, far less is known about its potential trans-generational effects. As the levels of avian yolk hormones can vary according to the mother's environment, we hypothesized that housing environment of mothers would modulate the quality of her eggs and in turn her offspring's behaviour. Two groups of female Japanese quail were constituted: a group that had access to a place to hide in their home-cage (Hd, n = 20 and a group that had nowhere to hide (NoHd, n = 20 when stressed. Both groups were submitted to daily human disturbances for a twenty-day-period. Hd females produced eggs with both less testosterone and androstenedione than did NoHd females. The emotional and social reactivity of Hd females' offspring were lower and their growth was slower than those of NoHd females' offspring. Our results show that a minor difference in housing environment had substantial effects on eggs and offspring. The presence of a shelter probably helped quail to cope with daily human disturbances, producing less reactive offspring. This transgenerational effect caused by an opportunity to hide could lead to applications in care of laboratory animals, conservation biology and animal welfare.

  17. Use of steam condensing at subatmospheric pressures to reduce Escherichia coli O157:H7 numbers on bovine hide.

    Science.gov (United States)

    McEvoy, J M; Doherty, A M; Sheridan, J J; Blair, I S; McDowell, D A

    2001-11-01

    This study used a laboratory-scale apparatus to apply subatmospheric steam to bovine hide pieces inoculated with Escherichia coli O157:H7 in maximum recovery diluent (MRD) and in high-liquid content and low-liquid content fecal suspensions (HLC fecal and LLC fecal, respectively). The survival of the organism in fecal clods, which were stored for 24 days in a desiccated state, was assessed. Inoculated fecal clods were also treated with subatmospheric steam. Steam treatment at 80 +/- 2 degrees C for 20 s reduced E. coli O157:H7 concentrations on hide inoculated to initial concentrations of approximately 7 log10 CFU/g by 5.46 (MRD inoculum), 4.17 (HLC fecal inoculum), and 5.99 (LLC fecal inoculum) log10 CFU/g. The reductions achieved in samples inoculated with LLC feces were larger than in samples inoculated with HLC feces (P Steam treatment (20 s) of 3-day-old clods reduced surviving E. coli O157:H7 numbers from 4.20 log10 CFU/g to below the limit of detection of the assay used (1.20 log10 CFU/g). This study shows that steam condensing at or below 80 +/- 2 degrees C can reduce E. coli O157:H7 when present on bovine hide, reducing the risk of cross contamination to the carcass during slaughter and dressing.

  18. Novel serine keratinase from Caldicoprobacter algeriensis exhibiting outstanding hide dehairing abilities.

    Science.gov (United States)

    Bouacem, Khelifa; Bouanane-Darenfed, Amel; Zaraî Jaouadi, Nadia; Joseph, Manon; Hacene, Hocine; Ollivier, Bernard; Fardeau, Marie-Laure; Bejar, Samir; Jaouadi, Bassem

    2016-05-01

    The current paper reports on the purification of an extracellular thermostable keratinase (KERCA) produced from Caldicoprobacter algeriensis strain TH7C1(T), a thermophilic, anaerobic bacterium isolated from a hydrothermal hot spring in Algeria. The maximum keratinase activity recorded after 24-h of incubation at 50 °C was 21000 U/ml. The enzyme was purified by ammonium sulfate precipitation-dialysis and heat treatment (2h at 50 °C) followed by UNO Q-6 FPLC anion exchange chromatography, and submitted to biochemical characterization assays. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS) analysis revealed that the purified enzyme was a monomer with a molecular mass of 33246.10 Da. The sequence of the 23 N-terminal residues of KERCA showed high homology with those of bacterial keratinases. Optimal activity was achieved at pH 7 and 50 °C. The enzyme was completely inhibited by phenylmethanesulfonyl fluoride (PMSF) and diiodopropyl fluorophosphates (DFP), which suggests that it belongs to the serine keratinase family. KERCA displayed higher levels of hydrolysis and catalytic efficiency than keratinase KERQ7 from Bacillus tequilensis strain Q7. These properties make KERCA a potential promising and eco-friendly alternative to the conventional chemicals used for the dehairing of goat, sheep, and bovine hides in the leather processing industry.

  19. Context adaptive binary arithmetic coding-based data hiding in partially encrypted H.264/AVC videos

    Science.gov (United States)

    Xu, Dawen; Wang, Rangding

    2015-05-01

    A scheme of data hiding directly in a partially encrypted version of H.264/AVC videos is proposed which includes three parts, i.e., selective encryption, data embedding and data extraction. Selective encryption is performed on context adaptive binary arithmetic coding (CABAC) bin-strings via stream ciphers. By careful selection of CABAC entropy coder syntax elements for selective encryption, the encrypted bitstream is format-compliant and has exactly the same bit rate. Then a data-hider embeds the additional data into partially encrypted H.264/AVC videos using a CABAC bin-string substitution technique without accessing the plaintext of the video content. Since bin-string substitution is carried out on those residual coefficients with approximately the same magnitude, the quality of the decrypted video is satisfactory. Video file size is strictly preserved even after data embedding. In order to adapt to different application scenarios, data extraction can be done either in the encrypted domain or in the decrypted domain. Experimental results have demonstrated the feasibility and efficiency of the proposed scheme.

  20. Performance evaluation of information hiding%信息隐藏性能评价方法

    Institute of Scientific and Technical Information of China (English)

    马秀莹; 林家骏

    2011-01-01

    It is necessary to establish a benchmark for information hiding. Imperceptibility is an important index to evaluate the performance of steganography. Based on HVS model, a new imperceptibility measure CHD for color stego image was proposed. Experimental results show that the quality of stego image calculated by CHD reflects the luminance masking, texture masking and color masking of HVS, and CHD can be used to evaluate the imperceptibility of steganography tools.%建立信息隐藏技术的评价标准十分必要.隐写术的视觉不可感知性是评价隐写术性能的重要指标之一.基于HVS模型,给出不可感知性评价指标CHD.实验结果表明,CHD的判定结果反映了人类视觉的亮度,对比度和色彩掩蔽特性,可以作为隐写术的不可感知性评价指标.

  1. Phenotypic mixing and hiding may contribute to memory in viral quasispecies

    CERN Document Server

    Wilke, C O; Wilke, Claus O.; Novella, Isabel S.

    2003-01-01

    Background. In a number of recent experiments with food-and-mouth disease virus, a deleterious mutant, was found to avoid extinction and remain in the population for long periods of time. This observation was called quasispecies memory. The origin of quasispecies memory is not fully understood. Results. We propose and analyze a simple model of complementation between the wild type virus and a mutant that has an impaired ability of cell entry. The mutant will go extinct unless it is recreated from the wild type through mutations. However, under phenotypic mixing-and-hiding as a mechanism of complementation, the time to extinction in the absence of mutations increases with increasing multiplicity of infection (m.o.i.). The mutant's frequency at equilibrium under selection-mutation balance also increases with increasing m.o.i. At high m.o.i., a large fraction of mutant genomes are encapsidated with wild-type protein, which enables them to infect cells as efficiently as the wild type virions, and thus increases t...

  2. Hiding the system from the user: Moving from complex mental models to elegant metaphors

    Energy Technology Data Exchange (ETDEWEB)

    Curtis W. Nielsen; David J. Bruemmer

    2007-08-01

    In previous work, increased complexity of robot behaviors and the accompanying interface design often led to operator confusion and/or a fight for control between the robot and operator. We believe the reason for the conflict was that the design of the interface and interactions presented too much of the underlying robot design model to the operator. Since the design model includes the implementation of sensors, behaviors, and sophisticated algorithms, the result was that the operator’s cognitive efforts were focused on understanding the design of the robot system as opposed to focusing on the task at hand. This paper illustrates how this very problem emerged at the INL and how the implementation of new metaphors for interaction has allowed us to hide the design model from the user and allow the user to focus more on the task at hand. Supporting the user’s focus on the task rather than on the design model allows increased use of the system and significant performance improvement in a search task with novice users.

  3. New approach for ensuring cloud computing security: using data hiding methods

    Indian Academy of Sciences (India)

    MURAT YESILYURT; YILDIRAY YALMAN

    2016-11-01

    Cloud computing is one of the largest developments occurred in the field of information technology during recent years. This model has become more desirable for all institutions, organizations and also for personal use thanks to the storage of ‘valuable information’ at low costs, access to such information from anywhere in the world as well as its ease of use and low cost. In this paper, the services constituting the cloud architecture and deployment models are examined, and the main factors in the provision of security requirements of all those models as well as points to be taken into consideration are described in detail. In addition, the methods and tools considering how security, confidentiality and integrity of the information or data that formsthe basis of modern technology are implemented in cloud computing architecture are examined. Finally, it is proposed in the paper that the use of data hiding methods in terms of access security in cloud computing architecture and the security of the stored data would be very effective in securing information.

  4. A simple method to hide data loggers safely in observation wells.

    Science.gov (United States)

    Lorenzen, Gunnar; Sprenger, Christoph; Pekdeger, Asaf

    2011-01-01

    Submersible data loggers are widely used for groundwater monitoring, but their application often runs the risk of hardware and data loss through vandalism or theft. During a field study in India, the authors of this article experienced that well locks attract the attention of unauthorized persons and do not provide secure protection in unattended areas. To minimize the risk of losing data loggers, a cheap and simple solution has been invented to hide the instruments and associated attachments below the ground surface, inside observation wells. It relies on attaching the logger to a length of small-diameter pipe that is submerged at the bottom of the well, instead of attaching it to the top of the well. The small-diameter pipe with the logger is connected to a small bottle containing a magnet that floats on the water surface of the well and can be recovered using another bottle also with a magnet. A logger that is concealed in this way is difficult to detect and access without knowledge of the method and adequate removal tools. The system was tested and successfully applied for monitoring shallow observation wells at three field sites in Greater Delhi, India. Copyright © 2010 The Author(s). Journal compilation © 2010 National Ground Water Association.

  5. Delegateable signatures based on non-interactive witness indistinguishable and non-interactive witness hiding proofs

    Institute of Scientific and Technical Information of China (English)

    TANG ChunMing; PEI DingYi; WANG XiaoFeng; LIU ZhuoJun

    2008-01-01

    A delegateable signature scheme (DSS) which was first introduced by Barak is mainly based on the non-interactive zero-knowledge proof (NIZK) for preventing the signing verifier from telling which witness (i.e., restricted subset) is being used. However, the scheme is not significantly efficient due to the difficulty of constructing NIZK. We first show that a non-Interactive witness indistinguishable (NIWI) proof sys-tern and a non-interactive witness hiding (NIWH) proof system are easier and more efficient proof models than NIZK in some cases. Furthermore, the witnesses em-ployed in these two protocols (NIWI and NIWT) cannot also be distinguished by the verifiers. Combined with the Σ-protocol, we then construct NlWl and NIWH proofs for any NP statement under the existence of one-way functions and show that each proof is different from those under the existence of trapdoor permutations. Finally, based on our NIWI and NIWH proofs, we construct delegateable signature schemes under the existence of one-way functions, which are more efficient than Barak's scheme under the existence of trapdoor permutations.

  6. A novel quantum information hiding protocol based on entanglement swapping of high-level Bell states

    Science.gov (United States)

    Xu, Shu-Jiang; Chen, Xiu-Bo; Wang, Lian-Hai; Niu, Xin-Xin; Yang, Yi-Xian

    2015-05-01

    Using entanglement swapping of high-level Bell states, we first derive a covert layer between the secret message and the possible output results of the entanglement swapping between any two generalized Bell states, and then propose a novel high-efficiency quantum information hiding protocol based on the covert layer. In the proposed scheme, a covert channel can be built up under the cover of a high-level quantum secure direct communication (QSDC) channel for securely transmitting secret messages without consuming any auxiliary quantum state or any extra communication resource. It is shown that this protocol not only has a high embedding efficiency but also achieves a good imperceptibility as well as a high security. Project supported by the National Natural Science Foundation of China (Grant Nos. 61303199, 61272514, 61170272, 61121061, and 61411146001), the Shandong Provincial Natural Science Foundation of China (Grant Nos. ZR2013FM025, ZR2013FQ001, and ZR2014FM003), the Shandong Provincial Outstanding Research Award Fund for Young Scientists of China (Grant Nos. BS2013DX010 and BS2014DX007), the Program for New Century Excellent Talents in Universities, China (Grant No. NCET-13-0681), the National Development Foundation for Cryptological Research, China (Grant No. MMJJ201401012), the Fok Ying Tong Education Foundation, China (Grant No. 131067), and the Shandong Academy of Sciences Youth Fund Project, China (Grant No. 2013QN007).

  7. HIDES spectroscopy of bright detached eclipsing binaries from the Kepler field - I. Single-lined objects

    Science.gov (United States)

    Hełminiak, K. G.; Ukita, N.; Kambe, E.; Kozłowski, S. K.; Sybilski, P.; Ratajczak, M.; Maehara, H.; Konacki, M.

    2016-09-01

    We present results of our spectroscopic observations of nine detached eclipsing binaries (DEBs), selected from the Kepler Eclipsing Binary Catalog, that only show one set of spectral lines. Radial velocities (RVs) were calculated from the high-resolution spectra obtained with the HIgh-Dispersion Echelle Spectrograph (HIDES) instrument, attached to the 1.88-m telescope at the Okayama Astrophysical Observatory, and from the public Apache Point Observatory Galactic Evolution Experiment archive. In our sample, we found five single-lined binaries, with one component dominating the spectrum. The orbital and light-curve solutions were found for four of them, and compared with isochrones, in order to estimate absolute physical parameters and evolutionary status of the components. For the fifth case, we only update the orbital parameters, and estimate the properties of the unseen star. Two other systems show orbital motion with a period known from the eclipse timing variations (ETVs). For these we obtained parameters of outer orbits, by translating the ETVs to RVs of the centre of mass of the eclipsing binary, and combining with the RVs of the outer star. Of the two remaining ones, one is most likely a blend of a faint background DEB with a bright foreground star, which lines we see in the spectra, and the last case is possibly a quadruple bearing a sub-stellar mass object. Where possible, we compare our results with literature, especially with results from asteroseismology. We also report possible detections of solar-like oscillations in our RVs.

  8. The significance of anisotropic signals hiding in the type Ia supernovae

    CERN Document Server

    Lin, Hai-Nan; Chang, Zhe

    2016-01-01

    We use two different methods, i.e., dipole-fitting (DF) and hemisphere comparison (HC), to search for the anisotropic signals hiding in the Union2.1 data set. We find that the directions of maximum matter density derived using these two methods are about $114^{\\circ}$ away from each other. We construct four Union2.1-like mock samples to test the statistical significance of these two methods. It is shown that DF method is statistically significant, while HC method is strongly biased by the distribution of data points in the sky. Then we assume that the anisotropy of distance modulus is mainly induced by the anisotropy of matter density, which is modeled to be the dipole form $\\Omega_M=\\Omega_{M0}(1-\\cos\\theta)$. We fit our model to Union2.1, and find that the direction of maximum matter density is well consistent with the direction derived using DF method, but it is very different from the direction previously claimed. Monte Carlo simulations show that our method is statistically more significant than HC metho...

  9. The Core Extrusion Schema-Revised: Hiding Oneself Predicts Severity of Social Interaction Anxiety.

    Science.gov (United States)

    Levinson, Cheri A; Rodebaugh, Thomas L; Lim, Michelle H; Fernandez, Katya C

    2017-01-01

    Cognitive behavioral models of social anxiety disorder (SAD) suggest that fear of negative evaluation is a core fear or vulnerability for SAD. However, why negative evaluation is feared is not fully understood. It is possible that core beliefs contribute to the relationship between fear of negative evaluation and SAD. One of these beliefs may be a core extrusion schema: a constellation of beliefs that one's true self will be rejected by others and therefore one should hide one's true self. In the current study (N = 699), we extended research on the Core Extrusion Schema and created a shortened and revised version of the measure called the Core Extrusion Schema-Revised The Core Extrusion Schema-Revised demonstrated good factor fit for its two subscales (Hidden Self and Rejection of the True Self) and was invariant across gender and ethnicity. The Hidden Self subscale demonstrated excellent incremental validity within the full sample as well as in participants diagnosed with generalized SAD. Specifically, the Hidden Self subscale may help explain severity of social interaction anxiety. This measure could be used with individuals diagnosed with generalized SAD to design exposures targeting these core beliefs.

  10. Hiding the word: examining the relationship between a new measure of religiosity and sexual behavior.

    Science.gov (United States)

    Young, Michael; Denny, George; Penhollow, Tina; Palacios, Rebecca; Morris, Duston

    2015-06-01

    The relationship between religiosity and sexual behavior has been previously investigated, but researchers have not examined the relationship between the intellectual dimension of religiosity and sexual behavior. In this study, we developed an intellectual measure of religiosity, Hiding the Word (HTW), and examined whether it accounted for variation in the sexual behavior of college students, beyond that for which age and a generic measure of religiosity could account. Results showed, after accounting for age and generic religiosity, HTW made a significant contribution to distinguishing between students who had, and those who had not, engaged in various sexual behaviors. For females, this was the case in three of the five behaviors examined (all except receiving oral sex and participating in unprotected penile-vaginal intercourse at most recent sexual encounter), and for males, two of the four behaviors (sexual intercourse and anal intercourse). HTW was less of a factor in accounting for variation in the frequency of participation. For males, HTW was significant for the frequency of participation in penile-vaginal intercourse, receiving oral sex, and the number of sexual partners in the last month. For females, HTW was significant only for the number of sexual partners in the last month. Thus, religiosity, and specifically HTW, seems to play more of a role in determining whether or not a person has participated in behavior, rather than in the frequency of participation.

  11. A Bed-Deformation Experiment Beneath Engabreen, Norway

    Science.gov (United States)

    Iverson, N. R.; Hooyer, T. S.; Fischer, U. H.; Cohen, D.; Jackson, M.; Moore, P. L.; Lappegard, G.; Kohler, J.

    2001-12-01

    Although deformation of sediment beneath ice masses may contribute to their motion and may sometimes enable fast glacier flow, both the kinematics and mechanics of deformation are controversial. This controversy stems, in part, from subglacial measurements that are difficult to interpret. Measurements have been made either beneath ice margins or remotely through boreholes with interpretive limitations caused by uncertain instrument position and performance, uncertain sediment thickness and bed geometry, and unknown disturbance of the bed and stress state by drilling. We have used a different approach made possible by the Svartisen Subglacial Laboratory, which enables human access to the bed of Engabreen, Norway, beneath 230 m of temperate ice. A trough (2 m x 1.5 m x 0.4 m deep) was blasted in the rock bed and filled with sediment (75 percent sand and gravel, 20 percent silt, 5 percent clay). Instruments were placed in the sediment to record shear deformation (tiltmeters), dilation and contraction, total normal stress, and pore-water pressure. Pore pressure was manipulated by feeding water to the base of the sediment with a high-pressure pump, operated in a rock tunnel 4 m below the bed surface. After irregular deformation during closure of ice on the sediment, shear deformation and volume change stopped, and total normal stress became constant at 2.2 MPa. Subsequent pump tests, which lasted several hours, induced pore-water pressures greater than 70 percent of the total normal stress and resulted in shear deformation over most of the sediment thickness with attendant dilation. Ice separated from the sediment when effective normal stress was lowest, arresting shear deformation. Displacement profiles during pump tests were similar to those observed by Boulton and co-workers at Breidamerkurjökull, Iceland, with rates of shear strain increasing upward toward the glacier sole. Such deformation does not require viscous deformation resistance and is expected in a

  12. A magmatic probe of dynamic topography beneath western North America

    Science.gov (United States)

    Klöcking, M.; White, N. J.; Maclennan, J.

    2014-12-01

    A region centered on the Yellowstone hotspot and encompassing the Colorado Plateau sits at an elevation 2 km higher than the cratonic North America. This difference broadly coincides with tomographically observed variations in lithospheric thickness: ~120 km beneath western North America, ~240 km beneath the craton. Thermochronology of the Grand Canyon area, sedimentary flux to the Gulf of Mexico, and river profile inversion all suggest that regional uplift occurred in at least two separate stages. High resolution seismic tomographic models, using USArray data, have identified a ring of low velocity material beneath the edges of the Colorado Plateau. Magmatism coincides with these low velocity zones and shows distinct phases: an overall increase in volume around 40 Ma and a change from lithospheric to asthenospheric signatures around 5 Ma. Volcanism is also observed to migrate north-east with time. Here, we attempt to integrate these different observations with lithospheric thickness. A dynamic topography model of progressive lithospheric erosion over a hot mantle plume might account for uplift as well as the temporal and spatial distribution of magmatism across western North America. Thinning of the lithosphere around the edges of the Colorado Plateau in combination with the hotter mantle potential temperature of a plume could create isostatic and dynamic uplift as well as allowing for melt production. To test this model, we have analysed around 100 samples from volcanic centers across western North America by ICP-MS for rare earth elements (REE). Most of the samples are younger than 5 Ma, and all of them have previously been analysed by XRF. Using trace element ratios such as La/Yb and Nb/Y we assess depth of melting and melt fraction, respectively. In addition, we use REE inversion modelling to estimate melt fractions as a function of depth and temperature of melting. The results are compared to existing constraints on lithospheric thickness and mantle potential

  13. On the Turbulence Beneath Finite Amplitude Water Waves

    CERN Document Server

    Babanin, Alexander V

    2015-01-01

    The paper by Beya et al. (2012, hereinafter BPB) has a general title of Turbulence Beneath Finite Amplitude Water Waves, but is solely dedicated to discussing the experiment by Babanin and Haus (2009, hereinafter BH) who conducted measurements of wave-induced non-breaking turbulence by particle image velocimetry (PIV). The authors of BPB conclude that their observations contradict those of BH. Here we argue that the outcomes of BPB do not contradict BH. In addition, although the main conclusion of BPB is that there is no turbulence observed in their experiment, it actually is observed.

  14. Climate variability effects on urban recharge beneath low impact development

    Science.gov (United States)

    Newcomer, M. E.; Gurdak, J. J.

    2012-12-01

    Groundwater resources in urban and coastal environments are highly vulnerable to human pressures and climate variability and change, and many communities face water shortages and need to find alternative water supplies. Therefore, understanding how low impact development (LID) site planning and integrated/best management practices (BMPs) affect recharge rates and volumes is important because of the increasing use of LID and BMP to reduce stormwater runoff and improve surface-water quality. Often considered a secondary management benefit, many BMPs may also enhance recharge to local aquifers; however these hypothesized benefits have not been thoroughly tested or quantified. In this study, we quantify stormwater capture and recharge enhancement beneath a BMP infiltration trench of the LID research network at San Francisco State University, San Francisco, California. Stormwater capture and retention was analyzed using the SCS TR-55 curve number method and in-situ infiltration rates to assess LID storage. Recharge was quantified using vadose zone monitoring equipment, a detailed water budget analysis, and a Hydrus-2D model. Additionally, the effects of historical and predicted future precipitation on recharge rates were examined using precipitation from the Geophysical Fluid Dynamic Laboratory (GFDL) A1F1 climate scenario. Observed recharge rates beneath the infiltration trench range from 1,600 to 3,700 mm/year and are an order of magnitude greater than recharge beneath an irrigated grass lawn and a natural setting. The Hydrus-2D model results indicate increased recharge under the GFDL A1F1 scenario compared with historical and GFDL modeled 20th century rates because of the higher frequency of large precipitation events that induce runoff into the infiltration trench. However, under a simulated A1F1 El Niño year, recharge calculated by a water budget does not increase compared with current El Niño recharge rates. In comparison, simulated recharge rates were

  15. Assessing theory of mind nonverbally in those with intellectual disability and ASD: the penny hiding game.

    Science.gov (United States)

    San José Cáceres, Antonia; Keren, Noa; Booth, Rhonda; Happé, Francesca

    2014-10-01

    Individuals with autism spectrum disorder (ASD) and low intellectual/language abilities are often omitted from experimental studies because of the challenges of testing these individuals. It is vital to develop appropriate and accessible tasks so that this significant part of the spectrum is not neglected. The theory of mind (ToM) has been extensively assessed in ASD, predominantly in relatively high-functioning individuals with reasonable language skills. This study aims to assess the ToM abilities of a sample of 132 participants with intellectual disability (ID) with and without ASD, matched in verbal mental age (VMA) and chronological age, using a naturalistic and nonverbal deception task: the Penny Hiding Game (PHG). The relationship between performance on the PHG and everyday adaptation was also studied. The PHG proved accessible to most participants, suggesting its suitability for use with individuals with low cognitive skills, attentional problems, and limited language. The ASD + ID group showed significantly more PHG errors, and fewer tricks, than the ID group. PHG performance correlated with Vineland adaptation scores for both groups. VMA was a major predictor of passing the task in both groups, and participants with ASD + ID required, on average, 2 years higher VMA than those with ID only, to achieve the same level of PHG success. VMA moderated the association between PHG performance and real-life social skills for the ASD + ID more than the ID group, suggesting that severely impaired individuals with ASD may rely on verbal ability to overcome their social difficulties, whereas individuals with ID alone may use more intuitive social understanding both in the PHG and everyday situations. © 2014 International Society for Autism Research, Wiley Periodicals, Inc.

  16. Information hiding techniques for infrared images: exploring the state-of-the art and challenges

    Science.gov (United States)

    Pomponiu, Victor; Cavagnino, Davide; Botta, Marco; Nejati, Hossein

    2015-10-01

    The proliferation of Infrared technology and imaging systems enables a different perspective to tackle many computer vision problems in defense and security applications. Infrared images are widely used by the law enforcement, Homeland Security and military organizations to achieve a significant advantage or situational awareness, and thus is vital to protect these data against malicious attacks. Concurrently, sophisticated malware are developed which are able to disrupt the security and integrity of these digital media. For instance, illegal distribution and manipulation are possible malicious attacks to the digital objects. In this paper we explore the use of a new layer of defense for the integrity of the infrared images through the aid of information hiding techniques such as watermarking. In this context, we analyze the efficiency of several optimal decoding schemes for the watermark inserted into the Singular Value Decomposition (SVD) domain of the IR images using an additive spread spectrum (SS) embedding framework. In order to use the singular values (SVs) of the IR images with the SS embedding we adopt several restrictions that ensure that the values of the SVs will maintain their statistics. For both the optimal maximum likelihood decoder and sub-optimal decoders we assume that the PDF of SVs can be modeled by the Weibull distribution. Furthermore, we investigate the challenges involved in protecting and assuring the integrity of IR images such as data complexity and the error probability behavior, i.e., the probability of detection and the probability of false detection, for the applied optimal decoders. By taking into account the efficiency and the necessary auxiliary information for decoding the watermark, we discuss the suitable decoder for various operating situations. Experimental results are carried out on a large dataset of IR images to show the imperceptibility and efficiency of the proposed scheme against various attack scenarios.

  17. Shear Wave Splitting Observations Beneath Uturuncu Volcano, Bolivia

    Science.gov (United States)

    Sims, N. E.; Christensen, D. H.; Moore-Driskell, M. M.

    2015-12-01

    Anisotropy in the upper mantle is often associated with mantle flow direction through the lattice preferred orientation of anisotropic minerals such as olivine in the upper mantle material. The flow of the mantle around subduction zones can be particularly complex, and thus difficult to explain. Because of its relationship to anisotropy, analysis of shear wave splitting measurements can help to answer questions regarding the upper mantle flow that surrounds subducting slabs. Here we present SK(K)S shear wave splitting measurements from a temporary broadband network (PLUTONS) of 33 stations deployed from April 2009 to October 2012 on the Altiplano plateau around Uturuncu volcano in Bolivia. The stations are spaced 10-20 km apart, providing a high spatial resolution of the region of the mantle directly below Uturuncu volcano. Despite the lack of numerous splitting results to analyze, preliminary measurements indicate a relatively consistent pattern of fast-polarization directions in a NW-SE orientation of about N80ºW. We think that it is likely that these observations come from anisotropy in the mantle wedge above the subducting Nazca plate indicating a direction of flow in the mantle wedge that is sub-parallel to the subduction direction of the Nazca plate. Although W-E flow beneath the subducting Nazca plate cannot be completely ruled out, these results appear to be consistent with the simple model of two-dimensional corner flow in the mantle wedge and slab-entrained mantle flow beneath the slab.

  18. Subglacial Sediment Deformation: An Experiment Beneath Engabreen, Norway

    Science.gov (United States)

    Fischer, U. H.; Iverson, N. R.; Hooyer, T. S.; Cohen, D.; Jackson, M.; Moore, P. L.; Lappegard, G.; Kohler, J.

    A detailed study of sediment deformation processes was carried out beneath Engabreen, Norway, by taking advantage of unique access to the bed of the glacier beneath 230 m of temperate ice via the Svartisen Subglacial Laboratory. One of the strengths of this novel approach is that many interpretive limitations caused by un- certainties inherent in similarly motivated borehole investigations are eliminated. A trough (approx. 2 m x 1.5 m x 0.4 m deep) was blasted in the rock bed and filled with sediment (75 per cent sand and gravel, 20 per cent silt, 5 per cent clay). Instruments were placed in the sediment to record shear deformation, dilation and contraction, total normal stress, and pore-water pressure. Pore pressure was manipulated by feeding wa- ter to the base of the sediment with a high-pressure pump, operated in a rock tunnel 4 m below the bed surface. After irregular deformation during closure of ice on the sed- iment, shear deformation and volume change stopped, and total normal stress became constant at 2.1 MPa. Pump tests conducted subsequently, which lasted several hours, induced pore-water pressures > 70 per cent of the total normal stress and resulted in shear deformation over most of the sediment thickness with attendant dilation. Ice sep- arated from the sediment when effective pressure was lowest, and shear deformation stopped. Velocity profiles averaged over the duration of pump tests indicate that rates of shear strain increase upward toward the glacier sole.

  19. Anelastic properties beneath the Niigata-Kobe Tectonic Zone, Japan

    Science.gov (United States)

    Nakajima, Junichi; Matsuzawa, Toru

    2017-02-01

    We estimate the three-dimensional (3D) P-wave attenuation structure beneath the Niigata-Kobe Tectonic Zone (NKTZ), central Japan, using high-quality waveform data from a large number of stations. The obtained results confirm the segmentation of the NKTZ into three regions, as suggested by 3D seismic velocity models, and reveal characteristic structures related to surface deformation, shallow subduction of the Philippine Sea slab, and magmatism. The lower crust beneath the NKTZ west of the Itoigawa-Shizuoka Tectonic Line (ISTL) is overall characterized by distinct high attenuation, whereas the upper crust shows marked high attenuation to the east of the ISTL. Differences in the depths of anelastically weakened parts of the crust probably result in a first-order spatial variation in surface deformation, forming wide (width of 100 km) and narrow (width of 25-40 km) deformation zones on the western and eastern sides of the ISTL, respectively. Many M ≥ 6.5 earthquakes occur in the upper crust where seismic attenuation in the underlying lower crust varies sharply, suggesting that spatial variations in rates of anelastic deformation in the lower crust result in stress concentration in the overlying brittle crust. We interpret a moderate- to low-attenuation zone located in the lower crust at the northeast of Biwa Lake to reflect low-temperature conditions that are developed locally as a result of shallow subduction of the cold Philippine Sea slab.

  20. D'' beneath the Arctic from inversion of shear waveforms

    Science.gov (United States)

    Kawai, Kenji; Geller, Robert J.; Fuji, Nobuaki

    2007-11-01

    The structure of the D'' region beneath the Arctic has not previously been studied in detail. Using waveform inversion, we find that the average S-wave velocity in D'' beneath the Arctic is about 0.04 km/s higher than PREM, which is consistent with the existence of post-perovskite (ppv) in D''. It is difficult to strongly constrain the fine structure of S-velocity within D'' due to the small number of stations at epicentral distances Δ weighting those stations heavily in the inversion, we show that the data suggest the existence of high S-velocity in the upper half of D'' and low S-velocity in the lower half, consistent with the possibility of a double crossing (ppv -> pv reverse phase transition) within D''. We conduct a computational experiment to show that resolution of the velocity structure within D'' could be significantly improved by temporary installation of a portable array of seismographs in northern Canada, which would greatly increase the number of stations in the range 70° < Δ < 90°.

  1. Simulation of Wave-Plus-Current Scour beneath Submarine Pipelines

    DEFF Research Database (Denmark)

    Eltard-Larsen, Bjarke; Fuhrman, David R.; Sumer, B. Mutlu

    2016-01-01

    A fully coupled hydrodynamic and morphologic numerical model was utilized for the simulation of wave-plus-current scour beneath submarine pipelines. The model was based on incompressible Reynolds-averaged Navier–Stokes equations, coupled with k-ω turbulence closure, with additional bed and suspen......A fully coupled hydrodynamic and morphologic numerical model was utilized for the simulation of wave-plus-current scour beneath submarine pipelines. The model was based on incompressible Reynolds-averaged Navier–Stokes equations, coupled with k-ω turbulence closure, with additional bed...... and suspended load descriptions forming the basis for seabed morphology. The model was successfully validated against experimental measurements involving scour development and eventual equilibrium in pure-current flows over a range of Shields parameters characteristic of both clear-water and live-bed regimes....... This validation complements previously demonstrated accuracy for the same model in simulating pipeline scour processes in pure-wave environments. The model was subsequently utilized to simulate combined wave-plus-current scour over a wide range of combined Keulegan–Carpenter numbers and relative current strengths...

  2. Shear wave anisotropy in D" region beneath the western Pacific

    Institute of Scientific and Technical Information of China (English)

    DAI Zhi-yang; LIU Bin; WANG Xiao-xiang; ZHA Xian-jie; ZHANG Hu; YANG Feng-qin

    2007-01-01

    Using seismic shear phases from 47 Tonga-Fiji and its adjacent region events recorded by the CENC and IRIS, and from 26 northeast Asia and north Pacific events recorded by IRIS, we studied the shear wave anisotropy in D" region beneath the western Pacific utilizing the ScS-S differential travel time method and obtained the splitting time values between the radial and transverse components of each ScS wave corresponding to each core-mantle boundary (CMB) reflection point. We found that most shear waves involved horizontally polarized shear wave components traveling faster than vertically polarized shear wave components through the D" region. The splitting time values of ScS wave range from (0.91 s to 3.21 s with an average value of 1.1 s. The strength of anisotropy varies from (0.45% to 1.56% with an average value of 0.52%. The observations and analyses show that in the D" region beneath the western Pacific the lateral flow is expected to be dominant and the vertical transverse isotropy may be the main anisotropic structure. This structure feature may be explained by the shape preferred orientation of the CMB chemical reaction products or partial melt and the lattice preferred orientation of the lower mantle materials caused by the lateral flow at lowermost mantle.

  3. Locating voids beneath pavement using pulsed electromagnetic waves

    Science.gov (United States)

    Steinway, W. J.; Echard, J. D.; Luke, C. M.

    1981-11-01

    The feasibility of using pulsed electromagnetic wave technology for locating and sizing voids beneath reinforced and nonreinforced portland cement concrete pavements is determined. The data processing techniques developed can be implemented to provide information for void depth and sizing to + or - 1/2 in. and spatial location within + or - 6 in. A very short pulse radar directly connected to a microcomputer was chosen as the equipment necessary to obtain measurements. This equipment has the required accuracy and reliability, and is a cost effective solution for the void locating problem. The radar provides a signal return from voids that has unique characteristics that can be examined to provide information regarding the location, depth, and shape of the void. The microcomputer provides a means of real time processing to extract the information from the radar signal return and record the results. Theoretical modeling of signal returns from voids led to suitable techniques for locating and sizing voids beneath the pavement. Analysis and application of these techniques to radar measurements verified the theoretical predictions that radar can be used to determine the location, size, and shape of actual voids.

  4. Slab melting and magma formation beneath the southern Cascade arc

    Science.gov (United States)

    Walowski, K. J.; Wallace, P. J.; Clynne, M. A.; Rasmussen, D. J.; Weis, D.

    2016-07-01

    The processes that drive magma formation beneath the Cascade arc and other warm-slab subduction zones have been debated because young oceanic crust is predicted to largely dehydrate beneath the forearc during subduction. In addition, geochemical variability along strike in the Cascades has led to contrasting interpretations about the role of volatiles in magma generation. Here, we focus on the Lassen segment of the Cascade arc, where previous work has demonstrated across-arc geochemical variations related to subduction enrichment, and H-isotope data suggest that H2O in basaltic magmas is derived from the final breakdown of chlorite in the mantle portion of the slab. We use naturally glassy, olivine-hosted melt inclusions (MI) from the tephra deposits of eight primitive (MgO > 7 wt%) basaltic cinder cones to quantify the pre-eruptive volatile contents of mantle-derived melts in this region. The melt inclusions have B concentrations and isotope ratios that are similar to mid-ocean ridge basalt (MORB), suggesting extensive dehydration of the downgoing plate prior to reaching sub-arc depths and little input of slab-derived B into the mantle wedge. However, correlations of volatile and trace element ratios (H2O/Ce, Cl/Nb, Sr/Nd) in the melt inclusions demonstrate that geochemical variability is the result of variable addition of a hydrous subduction component to the mantle wedge. Furthermore, correlations between subduction component tracers and radiogenic isotope ratios show that the subduction component has less radiogenic Sr and Pb than the Lassen sub-arc mantle, which can be explained by melting of subducted Gorda MORB beneath the arc. Agreement between pMELTS melting models and melt inclusion volatile, major, and trace element data suggests that hydrous slab melt addition to the mantle wedge can produce the range in primitive compositions erupted in the Lassen region. Our results provide further evidence that chlorite-derived fluids from the mantle portion of the

  5. Imaging Transition Zone Thickness Beneath South America from SS Precursors

    Science.gov (United States)

    Schmerr, N.; Garnero, E.

    2006-12-01

    We image detailed upper mantle discontinuity structure beneath a number of geologically active regions, including the South American subduction zone, the Scotia plate subduction zone, and several volcanic hotspots (e.g., the Galapagos Islands), in a region ~10,000 km by 10,000 km wide, spanning 70° S to 20° N and 20° W to 110° W. Precursors to the seismic phase SS are analyzed, which form as a result of underside reflections off seismic discontinuities beneath the midpoint of the SS path and are highly sensitive to discontinuity depth and sharpness. Our SS dataset consists of over 15,000 high-quality transverse component broadband displacement seismograms collected from the Incorporated Research Institutions for Seismology (IRIS), the Canadian National Seismic Network (CNSN), as well as data from EarthScope seismic stations, and from the Canadian Northwest Experiment (CANOE) temporary broadband array deployment. This dataset densely samples several regions in our study area and significantly improves the sampling for this area compared to previous precursor studies. Data with common central SS bouncepoints are stacked to enhance precursory phases. Solution discontinuity structure depends on a number of factors, including dominant seismic period, crustal correction, signal-to-noise ratio threshold, and tomography model used for mantle heterogeneity correction. We exclude precursor data predicted to interfere with other seismic phases, such as topside reflections (e.g., s670sS), which have been demonstrated to contaminate final stacks. Solution transition zone thickness is at least 20 km thicker than global average estimates of 242 km along the northwestern portion of the South American subduction complex (Peru, Ecuador, and Columbia); this thickening extends 1000-1500 km to the east beneath the continent, but does not appear to continue south of -20° latitude along the convergent margin. A minimum of 10 km of thickening is imaged to the west of the Scotia

  6. Pn anisotropic tomography and mantle dynamics beneath China

    Science.gov (United States)

    Zhou, Zhigang; Lei, Jianshe

    2016-08-01

    We present a new high-resolution Pn anisotropic tomographic model of the uppermost mantle beneath China inferred from 52,061 Pn arrival-time data manually picked from seismograms recorded at provincial seismic stations in China and temporary stations in Tibet and the Tienshan orogenic belt. Significant features well correlated with surface geology are revealed and provide new insights into the deep dynamics beneath China. Prominent high Pn velocities are visible under the stable cratonic blocks (e.g., the Tarim, Junngar, and Sichuan basins, and the Ordos block), whereas remarkable low Pn velocities are observed in the tectonically active areas (e.g., Pamir, the Tienshan orogenic belt, central Tibet and the Qilian fold belt). A distinct N-S trending low Pn velocity zone around 86°E is revealed under the rift running from the Himalayan block through the Lhasa block to the Qiangtang block, which indicates the hot material upwelling due to the breaking-off of the subducting Indian slab. Two N-S trending low Pn velocity belts with an approximate N-S Pn fast direction along the faults around the Chuan-Dian diamond block suggest that these faults may serve as channels of mantle flow from Tibet. The fast Pn direction changes from N-S in the north across 27°N to E-W in the south, which may reflect different types of mantle deformation. The anisotropy in the south could be caused by the asthenospheric flow resulted from the eastward subduction of the Indian plate down to the mantle transition zone beneath the Burma arc. Across the Talas-Fergana fault in the Tienshan orogenic belt, an obvious difference in velocity and anisotropy is revealed. To the west, high Pn velocities and an arc-shaped fast Pn direction are observed, implying the Indo-Asian collision, whereas to the east low Pn velocities and a range-parallel Pn fast direction are imaged, reflecting the northward underthrusting of the Tarim lithosphere and the southward underthrusting of the Kazakh lithosphere. In

  7. Downbursts and microbursts - An aviation hazard. [downdrafts beneath thunderstorms

    Science.gov (United States)

    Fujita, T. T.

    1980-01-01

    Downburst and microburst phenomena occurring since 1975 are studied, based on meteorological analyses of aircraft accidents, aerial surveys of wind effects left behind downbursts, and studies of sub-mesoscale wind systems. It is concluded that microbursts beneath small, air mass thunderstorms are unpredictable in terms of weather forecast. Most aircraft incidents, however, were found to have occurred in the summer months, June through August. An intense microburst could produce 150 mph horizontal winds as well as 60 fps downflows at the tree-top level. The largest contributing factor to aircraft difficulties seemed to be a combination of the headwind decrease and the downflow. Anemometers and/or pressure sensors placed near runways were found effective for detecting gust fronts, but not for detecting downbursts. It is recommended that new detection systems placed on the ground or airborne, be developed, and that pilots be trained for simulated landing and go-around through microbursts.

  8. Can slabs melt beneath forearcs in hot subduction zones?

    Science.gov (United States)

    Ribeiro, J.; Maury, R.; Gregoire, M.

    2015-12-01

    At subduction zones, thermal modeling predict that the shallow part of the downgoing oceanic crust (test the hypothesis that adakites are pristine slab melts. We find that adakites from Baja California and Philippines formed by two distinct petrogenetic scenarios. In Baja California, hydrous mantle melts mixed/mingled with high-pressure (HP) adakite-type, slab melts within a lower crustal (~30 km depth) magma storage region before stalling into the upper arc crust (~7-15 km depth). In contrast, in the Philippines, primitive mantle melts stalled and crystallized within lower and upper crustal magma storage regions to produce silica-rich melts with an adakitic signature. Thereby, slab melting is not required to produce an adakitic geochemical fingerprint in hot subduction zones. However, our results also suggest that the downgoing crust potentially melted beneath Baja California.

  9. Ocean mixing beneath Pine Island Glacier Ice Shelf

    Science.gov (United States)

    Kimura, Satoshi; Dutrieux, Pierre; Jenkins, Adrian; Forryan, Alexander; Naveira Garabato, Alberto; Firing, Yvonne

    2016-04-01

    Ice shelves around Antarctica are vulnerable to increase in ocean-driven melting, with the melt rate depending on ocean temperature and strength of sub-ice-shelf-cavity circulations. We present repeated measurements of velocity, temperature, salinity, turbulent kinetic energy dissipation rate and thermal variance dissipation rate beneath Pine Island Glacier Ice Shelf, collected by CTD, ADCP and turbulence sensors mounted on an Autonomous Underwater Vehicle (AUV). The turbulence quantities measured by the AUV outside the ice shelf are in good agreement with ship-based measurements. The highest rate of turbulent kinetic energy dissipation is found near the grounding line, while its temporal fluctuation over seabed ridge within the cavity corresponds to the tidal fluctuation predicted in the Pine Island Bay to the west. The highest thermal variance dissipation rate is found when the AUV was 0.5 m away from the ice, and the thermal variance dissipation generally increases with decreasing distance between the AUV and ice.

  10. Multicomponent seismic forward modeling of gas hydrates beneath the seafloor

    Institute of Scientific and Technical Information of China (English)

    Yang Jia-Jia; He Bing-Shou; Zhang Jian-Zhong

    2014-01-01

    We investigated the effect of microscopic distribution modes of hydrates in porous sediments, and the saturation of hydrates and free gas on the elastic properties of saturated sediments. We simulated the propagation of seismic waves in gas hydrate-bearing sediments beneath the seafloor, and obtained the common receiver gathers of compressional waves (P-waves) and shear waves (S-waves). The numerical results suggest that the interface between sediments containing gas hydrates and free gas produces a large-amplitude bottom-simulating reflector. The analysis of multicomponent common receiver data suggests that ocean-bottom seismometers receive the converted waves of upgoing P-and S-waves, which increases the complexity of the wavefield record.

  11. Subglacial lake drainage detected beneath the Greenland ice sheet.

    Science.gov (United States)

    Palmer, Steven; McMillan, Malcolm; Morlighem, Mathieu

    2015-10-09

    The contribution of the Greenland ice sheet to sea-level rise has accelerated in recent decades. Subglacial lake drainage events can induce an ice sheet dynamic response--a process that has been observed in Antarctica, but not yet in Greenland, where the presence of subglacial lakes has only recently been discovered. Here we investigate the water flow paths from a subglacial lake, which drained beneath the Greenland ice sheet in 2011. Our observations suggest that the lake was fed by surface meltwater flowing down a nearby moulin, and that the draining water reached the ice margin via a subglacial tunnel. Interferometric synthetic aperture radar-derived measurements of ice surface motion acquired in 1995 suggest that a similar event may have occurred 16 years earlier, and we propose that, as the climate warms, increasing volumes of surface meltwater routed to the bed will cause such events to become more common in the future.

  12. Subglacial lake drainage detected beneath the Greenland ice sheet

    Science.gov (United States)

    Palmer, Steven; McMillan, Malcolm; Morlighem, Mathieu

    2015-01-01

    The contribution of the Greenland ice sheet to sea-level rise has accelerated in recent decades. Subglacial lake drainage events can induce an ice sheet dynamic response—a process that has been observed in Antarctica, but not yet in Greenland, where the presence of subglacial lakes has only recently been discovered. Here we investigate the water flow paths from a subglacial lake, which drained beneath the Greenland ice sheet in 2011. Our observations suggest that the lake was fed by surface meltwater flowing down a nearby moulin, and that the draining water reached the ice margin via a subglacial tunnel. Interferometric synthetic aperture radar-derived measurements of ice surface motion acquired in 1995 suggest that a similar event may have occurred 16 years earlier, and we propose that, as the climate warms, increasing volumes of surface meltwater routed to the bed will cause such events to become more common in the future. PMID:26450175

  13. Salimicrobium salexigens sp. nov., a moderately halophilic bacterium from salted hides.

    Science.gov (United States)

    de la Haba, Rafael R; Yilmaz, Pinar; Sánchez-Porro, Cristina; Birbir, Meral; Ventosa, Antonio

    2011-09-01

    Two Gram-positive, moderately halophilic bacteria, designated strains 29CMI(T) and 53CMI, were isolated from salted hides. Both strains were non-motile, strictly aerobic cocci, growing in the presence of 3-25% (w/v) NaCl (optimal growth at 7.5-12.5% [w/v] NaCl), between pH 5.0 and 10.0 (optimal growth at pH 7.5) and at temperatures between 15 and 40°C (optimal growth at 37°C). Phylogenetic analysis based on 16S rRNA gene sequence comparison showed that both strains showed a similarity of 98.7% and were closely related to species of the genus Salimicrobium, within the phylum Firmicutes. Strains 29CMI(T) and 53CMI exhibited 16S rRNA gene sequence similarity values of 97.9-97.6% with Salimicrobium album DSM 20748(T), Salimicrobium halophilum DSM 4771(T), Salimicrobium flavidum ISL-25(T) and Salimicrobium luteum BY-5(T). The DNA G+C content was 50.7mol% and 51.5mol% for strains 29CMI(T) and 53CMI, respectively. The DNA-DNA hybridization between both strains was 98%, whereas the values between strain 29CMI(T) and the species S. album CCM 3517(T), S. luteum BY-5(T), S. flavidum ISL-25(T) and S. halophilum CCM 4074(T) were 45%, 28%, 15% and 10%, respectively, showing unequivocally that strains 29CMI(T) and 53CMI constitute a new genospecies. The major cellular fatty acids were anteiso-C(15:0), anteiso-C(17:0), iso-C(15:0) and iso-C(14:0). The main respiratory isoprenoid quinone was MK-7, although small amounts of MK-6 were also found. The polar lipids of the type strain consist of diphosphatidylglycerol, phosphatidylglycerol, one unidentified phospholipid and one glycolipid. The peptidoglycan type is A1γ, with meso-diaminopimelic acid as the diagnostic diamino acid. On the basis of the phylogenetic analysis, and phenotypic, genotypic and chemotaxonomic characteristics, we propose strains 29CMI(T) and 53CMI as a novel species of the genus Salimicrobium, with the name Salimicrobium salexigens sp. nov. The type strain is 29CMI(T) (=CECT 7568(T)=JCM 16414(T)=LMG 25386(T)).

  14. Magma heating by decompression-driven crystallization beneath andesite volcanoes.

    Science.gov (United States)

    Blundy, Jon; Cashman, Kathy; Humphreys, Madeleine

    2006-09-01

    Explosive volcanic eruptions are driven by exsolution of H2O-rich vapour from silicic magma. Eruption dynamics involve a complex interplay between nucleation and growth of vapour bubbles and crystallization, generating highly nonlinear variation in the physical properties of magma as it ascends beneath a volcano. This makes explosive volcanism difficult to model and, ultimately, to predict. A key unknown is the temperature variation in magma rising through the sub-volcanic system, as it loses gas and crystallizes en route. Thermodynamic modelling of magma that degasses, but does not crystallize, indicates that both cooling and heating are possible. Hitherto it has not been possible to evaluate such alternatives because of the difficulty of tracking temperature variations in moving magma several kilometres below the surface. Here we extend recent work on glassy melt inclusions trapped in plagioclase crystals to develop a method for tracking pressure-temperature-crystallinity paths in magma beneath two active andesite volcanoes. We use dissolved H2O in melt inclusions to constrain the pressure of H2O at the time an inclusion became sealed, incompatible trace element concentrations to calculate the corresponding magma crystallinity and plagioclase-melt geothermometry to determine the temperature. These data are allied to ilmenite-magnetite geothermometry to show that the temperature of ascending magma increases by up to 100 degrees C, owing to the release of latent heat of crystallization. This heating can account for several common textural features of andesitic magmas, which might otherwise be erroneously attributed to pre-eruptive magma mixing.

  15. Hydrothermal reservoir beneath Taal Volcano (Philippines): Implications to volcanic activity

    Science.gov (United States)

    Nagao, T.; Alanis, P. B.; Yamaya, Y.; Takeuchi, A.; Bornas, M. V.; Cordon, J. M.; Puertollano, J.; Clarito, C. J.; Hashimoto, T.; Mogi, T.; Sasai, Y.

    2012-12-01

    Taal Volcano is one of the most active volcanoes in the Philippines. The first recorded eruption was in 1573. Since then it has erupted 33 times resulting in thousands of casualties and large damages to property. In 1995, it was declared as one of the 15 Decade Volcanoes. Beginning in the early 1990s it has experienced several phases of abnormal activity, including seismic swarms, episodes of ground deformation, ground fissuring and hydrothermal activities, which continues up to the present. However, it has been noted that past historical eruptions of Taal Volcano may be divided into 2 distinct cycles, depending on the location of the eruption center, either at Main Crater or at the flanks. Between 1572-1645, eruptions occurred at the Main Crater, in 1707 to 1731, they occurred at the flanks. In 1749, eruptions moved back to the Main Crater until 1911. During the 1965 and until the end of the 1977 eruptions, eruptive activity once again shifted to the flanks. As part of the PHIVOLCS-JICA-SATREPS Project magnetotelluric and audio-magnetotelluric surveys were conducted on Volcano Island in March 2011 and March 2012. Two-dimensional (2-D) inversion and 3-D forward modeling reveals a prominent and large zone of relatively high resistivity between 1 to 4 kilometers beneath the volcano almost directly beneath the Main Crater, surrounded by zones of relatively low resistivity. This anomalous zone of high resistivity is hypothesized to be a large hydrothermal reservoir filled with volcanic fluids. The presence of this large hydrothermal reservoir could be related to past activities of Taal Volcano. In particular we believe that the catastrophic explosion described during the 1911 eruption was the result of the hydrothermal reservoir collapsing. During the cycle of Main Crater eruptions, this hydrothermal reservoir is depleted, while during a cycle of flank eruptions this reservoir is replenished with hydrothermal fluids.

  16. Image Hiding Technology Based on DCT and Chaos%基于DCT和混沌的图像隐藏技术①

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      提出一种基于 DCT 和混沌的图像隐藏算法。首先利用混沌系统产生混沌序列对秘密图像进行加密,然后利用DCT变换与混沌序列把秘密图像隐藏到载体图像中。实验结果表明,该算法具有良好的安全性和隐藏效果。%An improved image hiding technology based on DCT and chaos is presented. We use chaotic system to generate one chaotic sequence which is utilized to encrypt the secret image, and then we use DCT and chaotic sequence to realize the secret image hiding in the host image. Simulation results show that the algorithm has good security and hiding effect.

  17. 图像隐藏算法的MATLAB实现%Realization of image hiding algorithm based on MATLAB

    Institute of Scientific and Technical Information of China (English)

    宫海梅

    2016-01-01

    根据HVS的特性,人类视觉系统对高位信号敏感,去掉图像最低几个位并不会造成画面质量的明显下降,视觉系统就无法感觉到信号的存在,提出了四比特图像信息替换算法实现图像隐藏,运用MATLAB软件进行算法实现,嵌入信息后的载体图像与原始图像视觉效果基本一致,有效解决了图像信息隐藏问题。%According to the characteristics of HVS, The human visual system is sensitive to the high signal. To remove the image of the least number of bits does not cause a significant decline in the quality of picture, the visual system can not feel the existence of the signal. In this paper, four bit image information replacement algorithm is proposed to realize the image hiding, MATLAB software is used to realize the algorithm. The carrier image after embedding information is basically consistent with the original image, effectively solve the problem of image information hiding.

  18. A Note On the Bounds for the Generalized Fibonacci-p-Sequence and its Application in Data-Hiding

    CERN Document Server

    Dey, Sandipan; Sane, Suneeta; Sanyal, Sugata

    2010-01-01

    In this paper, we suggest a lower and an upper bound for the Generalized Fibonacci-p-Sequence, for ?different values of p. The Fibonacci-p-Sequence is a generalization of the Classical Fibonacci Sequence. We ?first show that the ratio of two consecutive terms in generalized Fibonacci sequence converges to a p-degree polynomial and then use this result to prove the bounds for generalized Fibonacci-p sequence, thereby generalizing the exponential bounds for classical Fibonacci Sequence. Then we show how these results can be used to prove efficiency for data hiding techniques using generalized Fibonacci sequence. These steganographic techniques use generalized Fibonacci-p-Sequence for increasing number available of bit-planes to hide data, so that more and more data can be hidden into the higher bit-planes of any pixel without causing much distortion of the cover image. This bound can be used as a theoretical proof for efficiency of those techniques, for instance it explains why more and more data can be hidden ...

  19. An Internal Data Non-hiding Type Real-time Kernel and its Application to the Mechatronics Controller

    Science.gov (United States)

    Yoshida, Toshio

    For the mechatronics equipment controller that controls robots and machine tools, high-speed motion control processing is essential. The software system of the controller like other embedded systems is composed of three layers software such as real-time kernel layer, middleware layer, and application software layer on the dedicated hardware. The application layer in the top layer is composed of many numbers of tasks, and application function of the system is realized by the cooperation between these tasks. In this paper we propose an internal data non-hiding type real-time kernel in which customizing the task control is possible only by change in the program code of the task side without any changes in the program code of real-time kernel. It is necessary to reduce the overhead caused by the real-time kernel task control for the speed-up of the motion control of the mechatronics equipment. For this, customizing the task control function is needed. We developed internal data non-cryptic type real-time kernel ZRK to evaluate this method, and applied to the control of the multi system automatic lathe. The effect of the speed-up of the task cooperation processing was able to be confirmed by combined task control processing on the task side program code using an internal data non-hiding type real-time kernel ZRK.

  20. Electrical conductivity anomaly beneath Mare Serenitatis detected by Lunokhod 2 and Apollo 16 magnetometers

    Science.gov (United States)

    Vanian, L. L.; Vnuchkova, T. A.; Egorov, I. V.; Basilevskii, A. T.; Eroshenko, E. G.; Fainberg, E. B.; Dyal, P.; Daily, W. D.

    1979-01-01

    Magnetic fluctuations measured by the Lunokhod 2 magnetometer in the Bay Le Monnier are distinctly anisotropic when compared to simultaneous Apollo 16 magnetometer data measured 1100 km away in the Descartes highlands. This anisotropy can be explained by an anomalous electrical conductivity of the upper mantle beneath Mare Serenitatis. A model is presented of anomalously lower electrical conductivity beneath Serenitatis and the simultaneous magnetic data from the Lunokhod 2 site at the mare edge and the Apollo 16 site are compared to the numerically calculated model solutions. This comparison indicates that the anisotropic fluctuations can be modeled by a nonconducting layer in the lunar lithosphere which is 150 km thick beneath the highlands and 300 km thick beneath Mare Serenitatis. A decreased electrical conductivity in the upper mantle beneath the mare may be due to a lower temperature resulting from heat carried out the magma source regions to the surface during mare flooding.

  1. Hide Tanning and Its Use in Taiga: The Case of the Orochen-Evenki Reindeer Herders and Hunters of Zabaikalye (East Siberia

    Directory of Open Access Journals (Sweden)

    Donatas Brandišauskas

    2010-12-01

    Full Text Available This article documents the way in which the Orochen-Evenki hunters and herders in northern part of Zabaikalye tan hides and produce gear in the post-Soviet era. Here, I wish to present the argument that it is difficult to understand the reviving of hide tanning in remote villages and the taiga without understanding how hunters and herders in this region adapt to the unstable post-Soviet environment. I suggest that hunters and herders aim to maintain their autonomy from goods and resources imported from cities, and, in spending little effort connecting with state powers in this way, securing their lives from socio-economic constraints.

  2. Improving the microbiological safety of veal: validation of hot water rinse plus lactic acid spray in combination with scalding for hide-on carcasses to control Shiga-toxin producing Escherichia coli (STEC)

    Science.gov (United States)

    Bob veal calves (n=6) were assigned to six hide-on carcass treatments for each of 5 replications. Primary treatments were no-scald, scald, or scalding with chemical; secondary treatments were no-treatment control or lactic acid. Hides were inoculated with non-pathogenic rifampicin-resistant Escheric...

  3. Time-Dependent Flexural Deformation Beneath the Emperor Seamounts

    Science.gov (United States)

    Wessel, P.; Watts, A. B.; Kim, S. S.

    2014-12-01

    The Hawaii-Emperor seamount chain stretches over 6000 km from the Big Island of Hawaii to the subduction cusp off Kamchatka and represents a near-continuous record of hotspot volcanism since the Late Cretaceous. The load of these seamounts and islands has caused the underlying lithosphere to deform, developing a flexural flanking moat that is now largely filled with volcanoclastic sediments. Because the age differences between the seafloor and the seamounts vary by an order of magnitude or more along the chain, the Hawaii-Emperor chain and surrounding area is considered a natural laboratory for lithospheric flexure and has been studied extensively in order to infer the rheology of the oceanic lithosphere. While most investigations have focused on the Hawaiian Islands and proximal seamounts (where data sets are more complete, including seismic reflection and refraction, swath bathymetry and even mapping and dating of drowned reef terraces), far fewer studies have examined the flexural deformation beneath the remote Emperor chain. Preliminary analysis of satellite altimetry data shows the flexural moats to be associated with very large negative gravity anomalies relative to the magnitudes of the positive anomalies over the loads, suggesting considerable viscous or viscoelastic relaxation since the loads were emplaced 50-80 Myr ago. In our study, we will attempt to model the Emperor seamount chain load as a superposition of individual elliptical Gaussian seamounts with separate loading histories. We use Optimal Robust Separation (ORS) techniques to extract the seamount load from the regional background bathymetry and partition the residual load into a set of individual volcanoes. The crustal age grid and available seamount dates are used to construct a temporal loading model and evaluate the flexural response of the lithosphere beneath the Emperor seamounts. We explore a variety of rheological models and loading scenarios that are compatible with the inferred load

  4. Seismic Constraints on the Mantle Viscosity Structure beneath Antarctica

    Science.gov (United States)

    Wiens, Douglas; Heeszel, David; Aster, Richard; Nyblade, Andrew; Wilson, Terry

    2015-04-01

    Lateral variations in upper mantle viscosity structure can have first order effects on glacial isostatic adjustment. These variations are expected to be particularly large for the Antarctic continent because of the stark geological contrast between ancient cratonic and recent tectonically active terrains in East and West Antarctica, respectively. A large misfit between observed and predicted GPS rates for West Antarctica probably results in part from the use of a laterally uniform viscosity structure. Although not linked by a simple relationship, mantle seismic velocities can provide important constraints on mantle viscosity structure, as they are both largely controlled by temperature and water content. Recent higher resolution seismic models for the Antarctic mantle, derived from data acquired by new seismic stations deployed in the AGAP/GAMSEIS and ANET/POLENET projects, offer the opportunity to use the seismic velocity structure to place new constraints on the viscosity of the Antarctic upper mantle. We use an Antarctic shear wave velocity model derived from array analysis of Rayleigh wave phase velocities [Heeszel et al, in prep] and examine a variety of methodologies for relating seismic, thermal and rheological parameters to compute a suite of viscosity models for the Antarctic mantle. A wide variety of viscosity structures can be derived using various assumptions, but they share several robust common elements. There is a viscosity contrast of at least two orders of magnitude between East and West Antarctica at depths of 80-250 km, reflecting the boundary between cold cratonic lithosphere in East Antarctica and warm upper mantle in West Antarctica. The region beneath the Ellsworth-Whitmore Mtns and extending to the Pensacola Mtns. shows intermediate viscosity between the extremes of East and West Antarctica. There are also significant variations between different parts of West Antarctica, with the lowest viscosity occurring beneath the Marie Byrd Land (MBL

  5. Sources and sinks of methane beneath polar ice

    Science.gov (United States)

    Priscu, J. C.; Adams, H. E.; Hand, K. P.; Dore, J. E.; Matheus-Carnevali, P.; Michaud, A. B.; Murray, A. E.; Skidmore, M. L.; Vick-Majors, T.

    2014-12-01

    Several icy moons of the outer solar system carry subsurface oceans containing many times the volume of liquid water on Earth and may provide the greatest volume of habitable space in our solar system. Functional sub-ice polar ecosystems on Earth provide compelling models for the habitability of extraterrestrial sub-ice oceans. A key feature of sub-ice environments is that most of them receive little to no solar energy. Consequently, organisms inhabiting these environments must rely on chemical energy to assimilate either carbon dioxide or organic molecules to support their metabolism. Methane can be utilized by certain bacteria as both a carbon and energy source. Isotopic data show that methane in Earth's polar lakes is derived from both biogenic and thermogenic sources. Thermogenic sources of methane in the thermokarst lakes of the north slope of Alaska yield supersaturated water columns during winter ice cover that support active populations of methanotrophs during the polar night. Methane in the permanently ice-covered lakes of the McMurdo Dry Valleys, Antarctica varies widely in concentration and is produced either by contemporary methanogenesis or is a relic from subglacial flow. Rate measurements revealed that microbial methane oxidation occurs beneath the ice in both the arctic and Antarctic lakes. The first samples collected from an Antarctic subglacial environment beneath 800 m of ice (Subglacial Lake Whillans) revealed an active microbial ecosystem that has been isolated from the atmosphere for many thousands of years. The sediments of Lake Whillans contained high levels of methane with an isotopic signature that indicates it was produced via methanogenesis. The source of this methane appears to be from the decomposition of organic carbon deposited when this region of Antarctica was covered by the sea. Collectively, data from these sub-ice environments show that methane transformations play a key role in microbial community metabolism. The discovery of

  6. Lateral variations of crustal structure beneath the Indochina Peninsula

    Science.gov (United States)

    Yu, Youqiang; Hung, Tran D.; Yang, Ting; Xue, Mei; Liu, Kelly H.; Gao, Stephen S.

    2017-08-01

    Crustal thickness (H) and Vp/Vs (κ) measurements obtained by stacking P-to-S receiver functions recorded at 32 broadband seismic stations covering the Indochina Peninsula reveal systematic spatial variations in crustal properties. Mafic bulk crustal composition as indicated by high κ (>1.81) observations is found to exist along major strike-slip faults and the southern part of the Peninsula, where pervasive basaltic magmatism is found and is believed to be the results of lithospheric thinning associated with the indentation of the Indian into the Eurasian plates. In contrast, crust beneath the Khorat Plateau, which occupies the core of the Indochina Block, has relatively large H values with a mean of 36.9 ± 3 km and small κ measurements with an average of 1.74 ± 0.04, which indicates an overall felsic bulk composition. Those observations for the Khorat Plateau are comparable to the undeformed part of the South China Block. The laterally heterogeneous distribution of crustal properties and its correspondence with indentation-related tectonic features suggest that the Indochina lithosphere is extruded as rigid blocks rather than as a viscous flow.

  7. Peeking Beneath the Caldera: Communicating Subsurface Knowledge of Newberry Volcano

    Science.gov (United States)

    Mark-Moser, M.; Rose, K.; Schultz, J.; Cameron, E.

    2016-12-01

    "Imaging the Subsurface: Enhanced Geothermal Systems and Exploring Beneath Newberry Volcano" is an interactive website that presents a three-dimensional subsurface model of Newberry Volcano developed at National Energy Technology Laboratory (NETL). Created using the Story Maps application by ArcGIS Online, this format's dynamic capabilities provide the user the opportunity for multimedia engagement with the datasets and information used to build the subsurface model. This website allows for an interactive experience that the user dictates, including interactive maps, instructive videos and video capture of the subsurface model, and linked information throughout the text. This Story Map offers a general background on the technology of enhanced geothermal systems and the geologic and development history of Newberry Volcano before presenting NETL's modeling efforts that support the installation of enhanced geothermal systems. The model is driven by multiple geologic and geophysical datasets to compare and contrast results which allow for the targeting of potential EGS sites and the reduction of subsurface uncertainty. This Story Map aims to communicate to a broad audience, and provides a platform to effectively introduce the model to researchers and stakeholders.

  8. Crawling beneath the free surface: Water snail locomotion

    CERN Document Server

    Lee, Sungyon; Hosoi, A E; Lauga, Eric

    2008-01-01

    Land snails move via adhesive locomotion. Through muscular contraction and expansion of their foot, they transmit waves of shear stress through a thin layer of mucus onto a solid substrate. Since a free surface cannot support shear stress, adhesive locomotion is not a viable propulsion mechanism for water snails that travel inverted beneath the free surface. Nevertheless, the motion of the freshwater snail, Sorbeoconcha physidae, is reminiscent of that of its terrestrial counterparts, being generated by the undulation of the snail foot that is separated from the free surface by a thin layer of mucus. Here, a lubrication model is used to describe the mucus flow in the limit of small amplitude interfacial deformations. By assuming the shape of the snail foot to be a traveling sine wave and the mucus to be Newtonian, an evolution equation for the interface shape is obtained and the resulting propulsive force on the snail is calculated. This propulsive force is found to be non-zero for moderate values of Capillar...

  9. Investigation of upper crustal structure beneath eastern Java

    Science.gov (United States)

    Martha, Agustya Adi; Widiyantoro, Sri; Cummnins, Phil; Saygin, Erdinc; Masturyono

    2016-05-01

    The complexity of geology structure in eastern Java causes this region has many potential resources as much as the disasters. Therefore, the East Java province represents an interesting area to be explored, especially regarding its upper crustal structure. To investigate this structure, we employ the Ambient Noise Tomography (ANT) method. We have used seismic waveform data from 25 Meteorological, Climatological and Geophysical Agency (BMKG) stationary seismographic stations and 26 portable seismographs installed for 2 to 8 weeks. Inter-station cross-correlation produces more than 800 Rayleigh wave components, which depict the structure beneath eastern Java. Based on the checkerboard resolution test, we found that the optimal grid size is 0.25ox0.25o. Our inversion results for the periods of 1 to 10 s indicate a good agreement with geological and Bouguer anomaly maps. Rembang high depression, most of the southern mountains zone, the northern part of Rembang zone and the central part of the Madura Island, the area of high gravity anomaly and areas dominated with igneous rocks are associated with high velocity zones. On the other hand, Kendeng zone and most of the basin in the Rembang zone are associated with low velocity zones.

  10. Geophysical investigation of seepage beneath an earthen dam.

    Science.gov (United States)

    Ikard, S J; Rittgers, J; Revil, A; Mooney, M A

    2015-01-01

    A hydrogeophysical survey is performed at small earthen dam that overlies a confined aquifer. The structure of the dam has not shown evidence of anomalous seepage internally or through the foundation prior to the survey. However, the surface topography is mounded in a localized zone 150 m downstream, and groundwater discharges from this zone periodically when the reservoir storage is maximum. We use self-potential and electrical resistivity tomography surveys with seismic refraction tomography to (1) determine what underlying hydrogeologic factors, if any, have contributed to the successful long-term operation of the dam without apparent indicators of anomalous seepage through its core and foundation; and (2) investigate the hydraulic connection between the reservoir and the seepage zone to determine whether there exists a potential for this success to be undermined. Geophysical data are informed by hydraulic and geotechnical borehole data. Seismic refraction tomography is performed to determine the geometry of the phreatic surface. The hydro-stratigraphy is mapped with the resistivity data and groundwater flow patterns are determined with self-potential data. A self-potential model is constructed to represent a perpendicular profile extending out from the maximum cross-section of the dam, and self-potential data are inverted to recover the groundwater velocity field. The groundwater flow pattern through the aquifer is controlled by the bedrock topography and a preferential flow pathway exists beneath the dam. It corresponds to a sandy-gravel layer connecting the reservoir to the downstream seepage zone.

  11. Ocean mixing beneath Pine Island Glacier ice shelf, West Antarctica

    Science.gov (United States)

    Kimura, Satoshi; Jenkins, Adrian; Dutrieux, Pierre; Forryan, Alexander; Naveira Garabato, Alberto C.; Firing, Yvonne

    2016-12-01

    Ice shelves around Antarctica are vulnerable to an increase in ocean-driven melting, with the melt rate depending on ocean temperature and the strength of flow inside the ice-shelf cavities. We present measurements of velocity, temperature, salinity, turbulent kinetic energy dissipation rate, and thermal variance dissipation rate beneath Pine Island Glacier ice shelf, West Antarctica. These measurements were obtained by CTD, ADCP, and turbulence sensors mounted on an Autonomous Underwater Vehicle (AUV). The highest turbulent kinetic energy dissipation rate is found near the grounding line. The thermal variance dissipation rate increases closer to the ice-shelf base, with a maximum value found ˜0.5 m away from the ice. The measurements of turbulent kinetic energy dissipation rate near the ice are used to estimate basal melting of the ice shelf. The dissipation-rate-based melt rate estimates is sensitive to the stability correction parameter in the linear approximation of universal function of the Monin-Obukhov similarity theory for stratified boundary layers. We argue that our estimates of basal melting from dissipation rates are within a range of previous estimates of basal melting.

  12. PN velocity beneath Western New Mexico and Eastern Arizona

    Science.gov (United States)

    Jaksha, L. H.

    1985-01-01

    The experiment involved observing Pn arrivals on an areal array of 7 seismic stations located in the transition zone and along the Jemez lineament. Explosions in coal and copper mines in New Mexico and Arizona were used as energy sources as well as military detonations at White Sands Missile Range, New Mexico, Yuma, Arizona, and the Nevada Test Site. Very preliminary results suggest a Pn velocity of 7.94 km/s (with a fairly large uncertainty) beneath the study area. The Pn delay times, which can be converted to estimates of crustal thickness given knowledge of the velocity structure of the crust increase both to the north and east of Springerville, Arizona. As a constraint on the velocity of Pn, researchers analyzed the reversed refraction line GNOME-HARDHAT which passes through Springerville oriented NW to SE. This analysis resulted in a Pn velocity of 7.9-8.0 km/s for the transition zone. These preliminary results suggest that a normal Pn velocity might persist even though the crust thins (from north to south) by 15 km along the length of the Arizona-New Mexico border. If the upper mantle is currently hot anywhere in western New Mexico or eastern Arizona then the dimensions of the heat source (or sources) might be small compared to the intra-station distances of the seismic arrays used to estimate the velocity of Pn.

  13. Crawling beneath the free surface: Water snail locomotion

    Science.gov (United States)

    Lee, Sungyon; Bush, John W. M.; Hosoi, A. E.; Lauga, Eric

    2008-08-01

    Land snails move via adhesive locomotion. Through muscular contraction and expansion of their foot, they transmit waves of shear stress through a thin layer of mucus onto a solid substrate. Since a free surface cannot support shear stress, adhesive locomotion is not a viable propulsion mechanism for water snails that travel inverted beneath the free surface. Nevertheless, the motion of the freshwater snail, Sorbeoconcha physidae, is reminiscent of that of its terrestrial counterparts, being generated by the undulation of the snail foot that is separated from the free surface by a thin layer of mucus. Here, a lubrication model is used to describe the mucus flow in the limit of small-amplitude interfacial deformations. By assuming the shape of the snail foot to be a traveling sine wave and the mucus to be Newtonian, an evolution equation for the interface shape is obtained and the resulting propulsive force on the snail is calculated. This propulsive force is found to be nonzero for moderate values of the capillary number but vanishes in the limits of high and low capillary number. Physically, this force arises because the snail's foot deforms the free surface, thereby generating curvature pressures and lubrication flows inside the mucus layer that couple to the topography of the foot.

  14. Soil property control of biogeochemical processes beneath two subtropical stormwater infiltration basins

    Science.gov (United States)

    O'Reilly, Andrew M.; Wanielista, Martin P.; Chang, Ni-Bin; Harris, Willie G.; Xuan, Zhemin

    2012-01-01

    Substantially different biogeochemical processes affecting nitrogen fate and transport were observed beneath two stormwater infiltration basins in north-central Florida. Differences are related to soil textural properties that deeply link hydroclimatic conditions with soil moisture variations in a humid, subtropical climate. During 2008, shallow groundwater beneath the basin with predominantly clayey soils (median, 41% silt+clay) exhibited decreases in dissolved oxygen from 3.8 to 0.1 mg L-1 and decreases in nitrate nitrogen (NO3-–N) from 2.7 mg L-1 to -1, followed by manganese and iron reduction, sulfate reduction, and methanogenesis. In contrast, beneath the basin with predominantly sandy soils (median, 2% silt+clay), aerobic conditions persisted from 2007 through 2009 (dissolved oxygen, 5.0–7.8 mg L-1), resulting in NO3-–N of 1.3 to 3.3 mg L-1 in shallow groundwater. Enrichment of d15N and d18O of NO3- combined with water chemistry data indicates denitrification beneath the clayey basin and relatively conservative NO3- transport beneath the sandy basin. Soil-extractable NO3-–N was significantly lower and the copper-containing nitrite reductase gene density was significantly higher beneath the clayey basin. Differences in moisture retention capacity between fine- and coarse-textured soils resulted in median volumetric gas-phase contents of 0.04 beneath the clayey basin and 0.19 beneath the sandy basin, inhibiting surface/subsurface oxygen exchange beneath the clayey basin. Results can inform development of soil amendments to maintain elevated moisture content in shallow soils of stormwater infiltration basins, which can be incorporated in improved best management practices to mitigate NO3- impacts.

  15. An Advancement To The Security Level Through Galois Field In The Existing Password Based Technique Of Hiding Classified Information In Images

    Directory of Open Access Journals (Sweden)

    Mita Kosode

    2015-06-01

    Full Text Available Abstract In this paper we are using the existing passcode based approach of hiding classified information in images with addition of the Galois field theorywhich is advancing the security level to make this combination method extremely difficult to intercept and useful for open channel communication while maintaining the losses and high speed transmission.

  16. Drusen-like beneath retinal deposits in type II mesangiocapillary glomerulonephritis: a review

    Directory of Open Access Journals (Sweden)

    Miguel Hage Amaro

    2015-02-01

    Full Text Available The aim of this paper is to do a review of Drusen-like beneath retinal deposits in type II mesangiocapillary glomerulonephritis. Drusenlike beneath retinal deposits in type II mesangiocapillary glomerulonephritis appear to develop at an early age, often second decade of life different of drusen from age-related macular degeneration (AMD.Long term follow-up of the cases in this disease shows in the most of them, no progression of the of drusen-like beneath retinal deposits in type II mesangiocapillary glomerulonefritis, the most of subjects retain good visual acuity and no specific treatment is indicated.

  17. 二值图像中的数据隐藏算法%Data Hiding in Binary Images

    Institute of Scientific and Technical Information of China (English)

    郭萌; 张鸿宾; 魏磊

    2009-01-01

    本文证明了在一个m×n的二值图像块中至多改变1个像素时所能隐藏的比特数的上界为[(log_2(mn+1)],并实际构造了达到此上界的信息隐藏算法.文中归纳了一些选择修改像素位置的规则,较好地保持了数据嵌入后图像的质量.对算法的鲁棒性和安全性进行了分析.用3个例子一数字手写签名中认证信息的嵌入、二值电子文档的窜改检测和卡通图像中注释信息的嵌入说明了本文算法可能的应用.%This paper proposes a method to embed data in binary images with high embedding capacity. It is proved that,given an m × n image block of the host image, the upper bound of the amount of bits that can be embedded in that block is L[(log_2(mn + 1)] ]by changing at most 1 pixel in the block. An algorithm whose embedding capacity can reach the bound is then constructed. We also summarize some rules for selecting pixels to be changed in order to maintain higher quality of the host image after data hiding. The robustness and security of the proposed algorithm is analyzed. Three examples,data hiding in digital handwritten signature, temper detection of digital binary documents, and invisible annotation for cartoon image are tested to illustrate the potential applications.

  18. Multi-scale Modelling of the Ocean Beneath Ice Shelves

    Science.gov (United States)

    Candy, A. S.; Kimura, S.; Holland, P.; Kramer, S. C.; Piggott, M. D.; Jenkins, A.; Pain, C. C.

    2011-12-01

    Quantitative prediction of future sea-level is currently limited because we lack an understanding of how the mass balance of the Earth's great ice sheets respond to and influence the climate. Understanding the behaviour of the ocean beneath an ice shelf and its interaction with the sheet above presents a great scientific challenge. A solid ice cover, in many places kilometres thick, bars access to the water column, so that observational data can only be obtained by drilling holes through, or launching autonomous vehicles beneath, the ice. In the absence of a comprehensive observational database, numerical modelling can be a key tool to advancing our understanding of the sub-ice-shelf regime. While we have a reasonable understanding of the overall ocean circulation and basic sensitivities, there remain critical processes that are difficult or impossible to represent in current operational models. Resolving these features adequately within a domain that includes the entire ice shelf and continental shelf to the north can be difficult with a structured horizontal resolution. It is currently impossible to adequately represent the key grounding line region, where the water column thickness reduces to zero, with a structured vertical grid. In addition, fronts and pycnoclines, the ice front geometry, shelf basal irregularities and modelling surface pressure all prove difficult in current approaches. The Fluidity-ICOM model (Piggott et al. 2008, doi:10.1002/fld.1663) simulates non-hydrostatic dynamics on meshes that can be unstructured in all three dimensions and uses anisotropic adaptive resolution which optimises the mesh and calculation in response to evolving solution dynamics. These features give it the flexibility required to tackle the challenges outlined above and the opportunity to develop a model that can improve understanding of the physical processes occurring under ice shelves. The approaches taken to develop a multi-scale model of ice shelf ocean cavity

  19. Simulation of Snow Processes Beneath a Boreal Scots Pine Canopy

    Institute of Scientific and Technical Information of China (English)

    LI Weiping; LUO Yong; XIA Kun; LIU Xin

    2008-01-01

    A physically-based multi-layer snow model Snow-Atmosphere-Soil-Transfer scheme (SAST) and a land surface model Biosphere-Atmosphere Transfer Scheme (BATS) were employed to investigate how boreal forests influence snow accumulation and ablation under the canopy. Mass balance and energetics of snow beneath a Scots pine canopy in Finland at different stages of the 2003-2004 and 2004-2005 snow seasons are analyzed. For the fairly dense Scots pine forest, drop-off of the canopy-intercepted snow contributes, in some cases, twice as much to the underlying snowpack as the direct throughfall of snow. During early winter snow melting, downward turbulent sensible and condensation heat fluxes play a dominant role together with downward net longwave radiation. In the final stage of snow ablation in middle spring, downward net all-wave radiation dominates the snow melting. Although the downward sensible heat flux is comparable to the net solar radiation during this period, evaporative cooling of the melting snow surface makes the turbulent heat flux weaker than net radiation. Sensitivities of snow processes to leaf area index (LAI) indicate that a denser canopy speeds up early winter snowmelt, but also suppresses melting later in the snow season. Higher LAI increases the interception of snowfall, therefore reduces snow accumulation under the canopy during the snow season; this effect and the enhancement of downward longwave radiation by denser foliage outweighs the increased attenuation of solar radiation, resulting in earlier snow ablation under a denser canopy. The difference in sensitivities to LAI in two snow seasons implies that the impact of canopy density on the underlying snowpack is modulated by interannual variations of climate regimes.

  20. Slab melting and magma generation beneath the southern Cascade Arc

    Science.gov (United States)

    Walowski, K. J.; Wallace, P. J.; Clynne, M. A.

    2014-12-01

    Magma formation in subduction zones is interpreted to be caused by flux melting of the mantle wedge by fluids derived from dehydration of the downgoing oceanic lithosphere. In the Cascade Arc and other hot-slab subduction zones, however, most dehydration reactions occur beneath the forearc, necessitating a closer investigation of magma generation processes in this setting. Recent work combining 2-D steady state thermal models and the hydrogen isotope composition of olivine-hosted melt inclusions from the Lassen segment of the Cascades (Walowski et al., 2014; in review) has shown that partial melting of the subducted basaltic crust may be a key part of the subduction component in hot arcs. In this model, fluids from the slab interior (hydrated upper mantle) rise through the slab and cause flux-melting of the already dehydrated MORB volcanics in the upper oceanic crust. In the Shasta and Lassen segments of the southern Cascades, support for this interpretation comes from primitive magmas that have MORB-like Sr isotope compositions that correlate with subduction component tracers (H2O/Ce, Sr/P) (Grove et al. 2002, Borg et al. 2002). In addition, mass balance calculations of the composition of subduction components show ratios of trace elements to H2O that are at the high end of the global arc array (Ruscitto et al. 2012), consistent with the role of a slab-derived melt. Melting of the subducted basaltic crust should contribute a hydrous dacitic or rhyolitic melt (e.g. Jego and Dasgupta, 2013) to the mantle wedge rather than an H2O-rich aqueous fluid. We are using pHMELTS and pMELTS to model the reaction of hydrous slab melts with mantle peridotite as the melts rise through the inverted thermal gradient in the mantle wedge. The results of the modeling will be useful for understanding magma generation processes in arcs that are associated with subduction of relatively young oceanic lithosphere.

  1. Seabed topography beneath Larsen C Ice Shelf from seismic soundings

    Directory of Open Access Journals (Sweden)

    A. M. Brisbourne

    2013-08-01

    Full Text Available Seismic reflection soundings of ice thickness and seabed depth were acquired on the Larsen C Ice Shelf in order to test a sub-shelf bathymetry model derived from the inversion of IceBridge gravity data. A series of lines were collected, from the Churchill Peninsula in the north to the Joerg Peninsula in the south, and also towards the ice front. Sites were selected using the bathymetry model derived from the inversion of free-air gravity data to indicate key regions where sub-shelf oceanic circulation may be affected by ice draft and sub-shelf cavity thickness. The seismic velocity profile in the upper 100 m of firn and ice was derived from shallow refraction surveys at a number of locations. Measured temperatures within the ice column and at the ice base were used to define the velocity profile through the remainder of the ice column. Seismic velocities in the water column were derived from previous in situ measurements. Uncertainties in ice and water cavity thickness are in general <10 m. Compared with the seismic measurements, the root-mean-square error in the gravimetrically derived bathymetry at the seismic sites is 162 m. The seismic profiles prove the non-existence of several bathymetric features that are indicated in the gravity inversion model, significantly modifying the expected oceanic circulation beneath the ice shelf. Similar features have previously been shown to be highly significant in affecting basal melt rates predicted by ocean models. The discrepancies between the gravity inversion results and the seismic bathymetry are attributed to the assumption of uniform geology inherent in the gravity inversion process and also the sparsity of IceBridge flight lines. Results indicate that care must be taken when using bathymetry models derived by the inversion of free-air gravity anomalies. The bathymetry results presented here will be used to improve existing sub-shelf ocean circulation models.

  2. Seabed topography beneath Larsen C Ice Shelf from seismic soundings

    Science.gov (United States)

    Brisbourne, A. M.; Smith, A. M.; King, E. C.; Nicholls, K. W.; Holland, P. R.; Makinson, K.

    2014-01-01

    Seismic reflection soundings of ice thickness and seabed depth were acquired on the Larsen C Ice Shelf in order to test a sub-ice shelf bathymetry model derived from the inversion of IceBridge gravity data. A series of lines was collected, from the Churchill Peninsula in the north to the Joerg Peninsula in the south, and also towards the ice front. Sites were selected using the bathymetry model derived from the inversion of free-air gravity data to indicate key regions where sub-ice shelf oceanic circulation may be affected by ice draft and seabed depth. The seismic velocity profile in the upper 100 m of firn and ice was derived from shallow refraction surveys at a number of locations. Measured temperatures within the ice column and at the ice base were used to define the velocity profile through the remainder of the ice column. Seismic velocities in the water column were derived from previous in situ measurements. Uncertainties in ice and water cavity thickness are in general model, significantly modifying the expected oceanic circulation beneath the ice shelf. Similar features have previously been shown to be highly significant in affecting basal melt rates predicted by ocean models. The discrepancies between the gravity inversion results and the seismic bathymetry are attributed to the assumption of uniform geology inherent in the gravity inversion process and also the sparsity of IceBridge flight lines. Results indicate that care must be taken when using bathymetry models derived by the inversion of free-air gravity anomalies. The bathymetry results presented here will be used to improve existing sub-ice shelf ocean circulation models.

  3. Fine structure of Pn velocity beneath Sichuan-Yunnan region

    Institute of Scientific and Technical Information of China (English)

    黄金莉; 宋晓东; 汪素云

    2003-01-01

    We use 23298 Pn arrival-time data from Chinese national and provincial earthquake bulletins to invert fine structure of Pn velocity and anisotropy at the top of the mantle beneath the Sichuan-Yunnan and its adjacent region. The results suggest that the Pn velocity in this region shows significant lateral variation; the Pn velocity varies from 7.7 to 8.3 km/s. The Pn-velocity variation correlates well with the tectonic activity and heat flow of the region. Low Pn velocity is observed in southwest Yunnan , Tengchong volcano area, and the Panxi tectonic area. These areas have very active seismicity and tectonic activity with high surface heat flow. On the other hand, high Pn velocity is observed in some stable regions, such as the central region of the Yangtze Platform; the most pronounced high velocity area is located in the Sichuan Basin, south of Chengdu. Pn anisotropy shows a complex pattern of regional deformation. The Pn fast direction shows a prominent clockwise rotation pattern from east of the Tibetan block to the Sichuan-Yunnan diamond block to southwest Yunnan, which may be related to southeastward escape of the Tibetan Plateau material due to the collision of the Indian Plate to the Eurasia Plate. Thus there appears to be strong correlation between the crustal deformation and the upper mantle structure in the region. The delay times of events and stations show that the crust thickness decreases from the Tibetan Plateau to eastern China, which is consistent with the results from deep seismic sounding.

  4. Conflicting Geophysical and Geochemical Indicators of Mantle Temperature Beneath Tibet

    Science.gov (United States)

    Klemperer, S. L.

    2013-12-01

    In Tibet a small number of earthquakes occurs at 75-100 km depth, spanning the Moho, reaching >350 km and >550 km north of the Himalayan front in south-eastern Tibet and western Tibet respectively. 'Earthquake thermometry' implies these deep earthquakes occur in anhydrous lower lithosphere, either anorthitic or ultramafic, at 0.1RA (~1% mantle fluid) are conventionally taken to imply an unequivocal mantle component. Time-averaged upward flow rates calculated from measured 3He/4He ratios (R) and [4He] range from ~1-15 cm/a, implying transport times of 0.5-7 Ma through a 70-km thick crust. Discussion of 3He in Tibet in the western literature has been dominated by a single paper (Hoke et al., EPSL, 2000) that reported modest mantle helium (0.110% mantle fluids are reported 120 km and 150 km south of the northern limit of deep earthquakes in southeastern and western Tibet respectively. These hot springs apparently sampled mantle with T>800°C south of the locations where earthquake thermometry implies Moho temperatures India, Nepal and Pakistan, even though the 800°C isotherm is substantially shallower there than beneath southern Tibet? More plausibly the mantle helium is derived from an Asian mantle wedge above the region of deep earthquakes, in which case underthrusting Indian lithosphere is not intact, but breaks into an upper layer forming the lower crust of the Tibetan Plateau, and a lower seismogenic layer that is subducted more deeply into the mantle. Based on the geothermal springs, an Asian mantle wedge extended south of the Indus Tsangpo suture in SE Tibet and to the Karakoram fault in W Tibet until the latest Miocene, or even more recently.

  5. Side-by-side comparison of field monitoring methods for hot bitumen emission exposures: the German IFA Method 6305, U.S. NIOSH Method 5042, and the Total Organic Matter Method.

    Science.gov (United States)

    Kriech, Anthony J; Emmel, Christoph; Osborn, Linda V; Breuer, Dietmar; Redman, Adam P; Hoeber, Dieter; Bochmann, Frank; Ruehl, Reinhold

    2010-12-01

    Field studies were conducted at paving and roofing sites to compare the German Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA) Fourier transform infrared spectroscopy method 6305 with the National Institute for Occupational Science and Health (NIOSH) benzene soluble fraction method 5042 plus total organic matter. Sampling using both methods was performed in multiple bitumen-related workplace environments. To provide comparable data all samplings were performed in parallel, and the analytical data were related to the same representative bitumen condensate standard. An outline of the differences between the sampling and analytical methods is provided along with comparative data obtained from these site investigations. A total of 55 bitumen paving sampler pairs were reported and statistical comparisons made using the 35 pairs of detectable data. First, the German inhalable aerosol data and the NIOSH benzene soluble fraction (BSF) method showed a correlation coefficient of R²= 0.88 (y((BSF))= 0.60 x((aerosol))). Second, the aerosol data compared with total particulate matter (TPM) show a R² of 0.83 (y((TPM))= 1.01 x((aerosol))). Finally, total organic matter (TOM) and "aerosol + vapor" data yielded a R² of 0.78 (y((TOM))= 0.44 x((aerosol+vapor))). Twenty-nine pairs of roofing data were also collected; 37% were below the limit of detection. When comparing the TOM data with the aerosol + vapor data, using the 13 of 29 pairs where both samplers showed detectable results, the relationship was y((TOM))= 0.74 x((aerosol+vapor)) (R²= 0.91). The slopes within these equations provide predictive factors between these sampling and analysis methods; intended for use with large sets of data, they are not applicable to single point measurements.

  6. Imaging Canary Island hotspot material beneath the lithosphere of Morocco and southern Spain

    Science.gov (United States)

    Miller, Meghan S.; O'Driscoll, Leland J.; Butcher, Amber J.; Thomas, Christine

    2015-12-01

    The westernmost Mediterranean has developed into its present day tectonic configuration as a result of complex interactions between late stage subduction of the Neo-Tethys Ocean, continental collision of Africa and Eurasia, and the Canary Island mantle plume. This study utilizes S receiver functions (SRFs) from over 360 broadband seismic stations to seismically image the lithosphere and uppermost mantle from southern Spain through Morocco and the Canary Islands. The lithospheric thickness ranges from ∼65 km beneath the Atlas Mountains and the active volcanic islands to over ∼210 km beneath the cratonic lithosphere in southern Morocco. The common conversion point (CCP) volume of the SRFs indicates that thinned lithosphere extends from beneath the Canary Islands offshore southwestern Morocco, to beneath the continental lithosphere of the Atlas Mountains, and then thickens abruptly at the West African craton. Beneath thin lithosphere between the Canary hot spot and southern Spain, including below the Atlas Mountains and the Alboran Sea, there are distinct pockets of low velocity material, as inferred from high amplitude positive, sub-lithospheric conversions in the SRFs. These regions of low seismic velocity at the base of the lithosphere extend beneath the areas of Pliocene-Quaternary magmatism, which has been linked to a Canary hotspot source via geochemical signatures. However, we find that this volume of low velocity material is discontinuous along strike and occurs only in areas of recent volcanism and where asthenospheric mantle flow is identified with shear wave splitting analyses. We propose that the low velocity structure beneath the lithosphere is material flowing sub-horizontally northeastwards beneath Morocco from the tilted Canary Island plume, and the small, localized volcanoes are the result of small-scale upwellings from this material.

  7. Potential subglacial lake locations and meltwater drainage pathways beneath the Antarctic and Greenland ice sheets

    OpenAIRE

    Livingstone, S.J.; Clark, C. D.; Woodward, J.; Kingslake, J.

    2013-01-01

    We use the Shreve hydraulic potential equation as a simplified approach to investigate potential subglacial lake locations and meltwater drainage pathways beneath the Antarctic and Greenland ice sheets. We validate the method by demonstrating its ability to recall the locations of > 60\\% of the known subglacial lakes beneath the Antarctic Ice Sheet. This is despite uncertainty in the ice-sheet bed elevation and our simplified modelling approach. However, we predict many more lakes than are ob...

  8. No Place to Hide: Missing Primitive Stars Outside Milky Way Uncovered

    Science.gov (United States)

    2010-02-01

    , Sculptor, Sextans and Carina dwarf galaxies. Since the dwarf galaxies are typically 300 000 light years away - which is about three times the size of our Milky Way - only strong features in the spectrum could be measured, like a vague, smeared fingerprint. The team found that none of their large collection of spectral fingerprints actually seemed to belong to the class of stars they were after, the rare, extremely metal-poor stars found in the Milky Way. The team of astronomers around Starkenburg has now shed new light on the problem through careful comparison of spectra to computer-based models. They found that only subtle differences distinguish the chemical fingerprint of a normal metal-poor star from that of an extremely metal-poor star, explaining why previous methods did not succeed in making the identification. The astronomers also confirmed the almost pristine status of several extremely metal-poor stars thanks to much more detailed spectra obtained with the UVES instrument on ESO's Very Large Telescope. "Compared to the vague fingerprints we had before, this would be as if we looked at the fingerprint through a microscope," explains team member Vanessa Hill. "Unfortunately, just a small number of stars can be observed this way because it is very time consuming." "Among the new extremely metal-poor stars discovered in these dwarf galaxies, three have a relative amount of heavy chemical elements between only 1/3000 and 1/10 000 of what is observed in our Sun, including the current record holder of the most primitive star found outside the Milky Way," says team member Martin Tafelmeyer. "Not only has our work revealed some of the very interesting, first stars in these galaxies, but it also provides a new, powerful technique to uncover more such stars," concludes Starkenburg. "From now on there is no place left to hide!" Notes [1] According to the definition used in astronomy, "metals" are all the elements other than hydrogen and helium. Such metals, except for a very

  9. Trench-parallel flow beneath the nazca plate from seismic anisotropy.

    Science.gov (United States)

    Russo, R M; Silver, P G

    1994-02-25

    Shear-wave splitting of S and SKS phases reveals the anisotropy and strain field of the mantle beneath the subducting Nazca plate, Cocos plate, and the Caribbean region. These observations can be used to test models of mantle flow. Two-dimensional entrained mantle flow beneath the subducting Nazca slab is not consistent with the data. Rather, there is evidence for horizontal trench-parallel flow in the mantle beneath the Nazca plate along much of the Andean subduction zone. Trench-parallel flow is attributale utable to retrograde motion of the slab, the decoupling of the slab and underlying mantle, and a partial barrier to flow at depth, resulting in lateral mantle flow beneath the slab. Such flow facilitates the transfer of material from the shrinking mantle reservoir beneath the Pacific basin to the growing mantle reservoir beneath the Atlantic basin. Trenchparallel flow may explain the eastward motions of the Caribbean and Scotia sea plates, the anomalously shallow bathymetry of the eastern Nazca plate, the long-wavelength geoid high over western South America, and it may contribute to the high elevation and intense deformation of the central Andes.

  10. Three-dimensional numerical modeling of thermal regime and slab dehydration beneath Kanto and Tohoku, Japan

    Science.gov (United States)

    Ji, Yingfeng; Yoshioka, Shoichi; Manea, Vlad Constantin; Manea, Marina; Matsumoto, Takumi

    2017-01-01

    Although the thermal regime of the interface between two overlapping subducting plates, such as those beneath Kanto, Japan, is thought to play an important role in affecting the distribution of interplate and intraslab earthquakes, the estimation of the thermal regime remains challenging to date. We constructed a three-dimensional (3-D) thermal convection model to simulate the subduction of the Pacific plate along the Japan Trench and Izu-Bonin Trench, including the subduction of the Philippine Sea beneath Kanto and investigated the slab thermal regime and slab water contents in this complex tectonic setting. Based on the subduction parameters tested in generic models with two flat oceanic plates, a faster or thicker plate subducting in a more trench-normal direction produces a colder slab thermal regime. The interplate temperature of the cold anomaly beneath offshore Kanto was approximately 300°C colder than that beneath offshore Tohoku at a same depth of 40 km and approximately 600°C colder at a depth of 70 km. The convergence between the two subducting plates produces an asymmetric thermal structure in the slab contact zone beneath Kanto, which is characterized by clustered seismicity in the colder southwestern half. The thermo-dehydration state of the mid-ocean ridge basalt near the upper surface of the subducted Pacific plate controls the interplate seismicity beneath the Kanto-Tohoku region according to the spatial concurrence of the thermo-dehydration and seismicity along the megathrust fault zone of the subducted Pacific plate.

  11. Extensive, water-rich magma reservoir beneath southern Montserrat

    Science.gov (United States)

    Edmonds, M.; Kohn, S. C.; Hauri, E. H.; Humphreys, M. C. S.; Cassidy, M.

    2016-05-01

    South Soufrière Hills and Soufrière Hills volcanoes are 2 km apart at the southern end of the island of Montserrat, West Indies. Their magmas are distinct geochemically, despite these volcanoes having been active contemporaneously at 131-129 ka. We use the water content of pyroxenes and melt inclusion data to reconstruct the bulk water contents of magmas and their depth of storage prior to eruption. Pyroxenes contain up to 281 ppm H2O, with significant variability between crystals and from core to rim in individual crystals. The Al content of the enstatites from Soufrière Hills Volcano (SHV) is used to constrain melt-pyroxene partitioning for H2O. The SHV enstatite cores record melt water contents of 6-9 wt%. Pyroxene and melt inclusion water concentration pairs from South Soufriere Hills basalts independently constrain pyroxene-melt partitioning of water and produces a comparable range in melt water concentrations. Melt inclusions recorded in plagioclase and in pyroxene contain up to 6.3 wt% H2O. When combined with realistic melt CO2 contents, the depth of magma storage for both volcanoes ranges from 5 to 16 km. The data are consistent with a vertically protracted crystal mush in the upper crust beneath the southern part of Montserrat which contains heterogeneous bodies of eruptible magma. The high water contents of the magmas suggest that they contain a high proportion of exsolved fluids, which has implications for the rheology of the mush and timescales for mush reorganisation prior to eruption. A depletion in water in the outer 50-100 μm of a subset of pyroxenes from pumices from a Vulcanian explosion at Soufrière Hills in 2003 is consistent with diffusive loss of hydrogen during magma ascent over 5-13 h. These timescales are similar to the mean time periods between explosions in 1997 and in 2003, raising the possibility that the driving force for this repetitive explosive behaviour lies not in the shallow system, but in the deeper parts of a vertically

  12. Bed-Deformation Experiments Beneath a Temperate Glacier

    Science.gov (United States)

    Iverson, N. R.; Hooyer, T. S.; Fischer, U. H.; Cohen, D.; Jackson, M.; Moore, P. L.; Lappegard, G.; Kohler, J.

    2002-12-01

    Fast flow of glaciers and genesis of glacial landforms are commonly attributed to shear deformation of subglacial sediment. Although models of this process abound, data gathered subglacially on the kinematics and mechanics of such deformation are difficult to interpret. Major difficulties stem from the necessity of either measuring deformation near glacier margins, where conditions may be abnormal, or at the bottoms of boreholes, where the scope of instrumentation is limited, drilling disturbs sediment, and local boundary conditions are poorly known. A different approach is possible at the Svartisen Subglacial Laboratory, where tunnels melted in the ice provide temporary human access to the bed of Engabreen, a temperate outlet glacier of the Svartisen Ice Cap in Norway. A trough (2 m x 1.5 m x 0.5 m deep) was blasted in the rock bed, where the glacier is 220 m thick and sliding at 0.1-0.2 m/d. During two spring field seasons, this trough was filled with 2.5 tons of simulated till. Instruments in the till recorded shear (tiltmeters), volume change, total normal stress, and pore-water pressure as ice moved across the till surface. Pore pressure was brought to near the total normal stress by feeding water to the base of the till with a high-pressure pump, operated in a rock tunnel 4 m below the bed surface. Results illustrate some fundamental aspects of bed deformation. Permanent shear deformation requires low effective normal stress and hence high pore-water pressure, owing to the frictional nature of till. Shear strain generally increases upward in the bed toward the glacier sole, consistent with previous measurements beneath thinner ice at glacier margins. At low effective normal stresses, ice sometimes decouples from underlying till. Overall, bed deformation accounts for 10-35 % of basal motion, although this range excludes shear in the uppermost 0.05 m of till where shear was not measured. Pump tests with durations ranging from seconds to hours highlight the need

  13. Metastable olivine wedge beneath northeast China and its applications

    Science.gov (United States)

    Jiang, G.; Zhao, D.; Zhang, G.

    2013-12-01

    When the Pacific slab subducted into the mantle transition zone, there might exist a metastable olivine wedge (MOW) inside the slab due to the phase transition. Lots of researchers have adopted such various methods to detect the characteristics of this MOW as the forward modeling of travel times, shear wave amplitude patterns, teleseismic P wave coda, receiver function imaging, thermodynamic simulation and so on. Almost all results could be more or less affected by the source, the receiver and/or the velocity model passed through by the seismic rays. In this study, we have used 21 deep earthquakes, greater than 400 km and locating beneath northeast China, to study the velocity within the MOW. For more precisions, we have done further modifications in two ways based on our previous studies. (1) Double-difference location method is used to relocate all events with an error of 1-2 km with the data recorded by stations both at northeast China and at Japan. All relocated events locate in a zone about 30 km away from the upper boundary of Pacific slab. (2) Double residual travel times, generated by an event-pair at a common station at only Japan, are used to constrain the velocity anomaly rather than the residuals themselves. As a result, we have found that an ultra-lower velocity zone (ULVZ), averagely -7% relative to the iasp91 model, exists within the subducted Pacific slab around the deep earthquakes, which might be represented as the metastable olivine wedge. Because of the lower-velocity corresponding to the lower-density, the MOW would provide upward buoyancy forces which might prevent the slab from free subduction into the mantle transition zone. This feed-back mechanism of MOW to the slab is called ';parachute-effect', which is characterized by other researchers. In addition, the existence of the ULVZ or the MOW in the slab may supply a possible mechanism for triggering deep earthquakes, called ';phase transformation faulting', which was already proposed few

  14. Stratocumulus cloud thickening beneath layers of absorbing smoke aerosol

    Science.gov (United States)

    Wilcox, E. M.

    2010-12-01

    Marine stratocumulus cloud properties, and the free-tropospheric environment above them, are examined in NASA A-Train satellite data for cases where smoke from seasonal burning of the West African savannah overlay the persistent southeast Atlantic stratocumulus cloud deck. CALIPSO space-borne lidar observations show that features identified as layers of aerosol occur predominantly between 2 km and 4 km. Layers identified as cloud features occur predominantly below 1.5 km altitude and beneath the layer of elevated smoke aerosol. The diurnal mean shortwave heating rates attributable to the absorption of solar energy in the aerosol layer is nearly 1.5 K d-1 for an aerosol optical thickness value of 1, and increases to 1.8 K d-1 when the smoke resides above clouds owing to the additional component of upward solar radiation reflected by the cloud. As a consequence of this heating, the 700 hPa air temperature above the cloud deck is warmer by approximately 1 K on average for cases where smoke is present above the cloud compared to cases without smoke above cloud. The warmer conditions in the free-troposphere above the cloud during smoke events coincide with cloud liquid water path values that are greater by 20 g m-2 and cloud tops that are lower for overcast conditions compared to periods with low amounts of smoke. The observed thickening and subsidence of the cloud layer are consistent with published results of large-eddy simulations showing that solar absorption by smoke above stratocumulus clouds increases the buoyancy of free-tropospheric air above the temperature inversion capping the boundary layer. Increased buoyancy inhibits the entrainment of dry air through the cloud-top, thereby helping to preserve humidity and cloud cover in the boundary layer. The direct radiative effect of absorbing aerosols residing over a bright cloud deck is a positive radiative forcing (warming) at the top of the atmosphere. However, the greater liquid water path for cases of smoke

  15. Mantle transition zone shear velocity gradients beneath USArray

    Science.gov (United States)

    Schmandt, Brandon

    2012-11-01

    Broadband P-to-s scattering isolated by teleseismic receiver function analysis is used to investigate shear velocity (VS) gradients in the mantle transition zone beneath USArray. Receiver functions from 2244 stations were filtered in multiple frequency bands and migrated to depth through P and S tomography models. The depth-migrated receiver functions were stacked along their local 410 and 660 km discontinuity depths to reduce stack incoherence and more accurately recover the frequency-dependent amplitudes of P410s and P660s. The stacked waveforms were inverted for one-dimensional VS between 320 and 840 km depth. First, a gradient-based inversion was used to find a least-squares solution and a subsequent Monte Carlo search about that solution constrained the range of VS profiles that provide an acceptable fit to the receiver function stacks. Relative to standard references models, all the acceptable models have diminished VS gradients surrounding the 410, a local VS gradient maximum at 490-500 km depth, and an enhanced VS gradient above the 660. The total 410 VS increase of 6.3% is greater than in reference models, and it occurs over a thickness of 20 km. However, 60% of this VS increase occurs over only 6 km. The 20 km total thickness of the 410 and diminished VS gradients surrounding the 410 are potential indications of high water content in the regional transition zone. An enhanced VS gradient overlying the 660 likely results from remnants of subduction lingering at the base of the transition zone. Cool temperatures from slabs subducted since the late Cretaceous and longer-term accumulation of former ocean crust both may contribute to the high gradient above the 660. The shallow depth of the 520 km discontinuity, 490-500 km, implies that the regional mean temperature in the transition zone is 110-160 K cooler than the global mean. A concentrated Vs gradient maximum centered near 660 km depth and a low VS gradient below 675 km confirms that the ringwoodite to

  16. Cathodic protection beneath thick external coating on flexible pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Festy, Dominique; Choqueuse, Dominique; Leflour, Denise; Lepage, Vincent [Ifremer - Centre de Brest, BP 70 29280 Plouzane (France); Condat, Carol Taravel; Desamais, Nicolas [Technip- FLEXIFRANCE - PED/PEC - Rue Jean Hure, 76580 Le Trait (France); Tribollet, Bernard [UPR 15 du CNRS, Laboratoire LISE, 4 Place Jussieu, 75252 Paris Cedex (France)

    2004-07-01

    Flexible offshore pipelines possess an external polymer sheath to protect the structure against seawater. In case of an accidental damage of the outer sheath, the annulus of the flexible pipe is flooded with seawater. Far from the damage, corrosion and/or corrosion fatigue of armour steel wires in the annulus occur in a strictly deaerated environment; this has been studied for a few years. At the damage location, the steel wires are in direct contact with renewed seawater. In order to protect them against corrosion, a cathodic protection is applied using sacrificial anodes located at the end fittings. The goal of this work is to evaluate the extent of the cathodic protection as well as the electrolyte oxygen concentration beneath the coating around the damage, to know whether or not there is a non protected area with enough oxygen where corrosion and corrosion fatigue can occur. The experimental work was performed with a model cell (2000 x 200 mm{sup 2}), composed of a mild steel plate and a PMMA coat (transparent poly-methyl-methacrylate). The thickness of the gap between the steel plate and the PMMA coat was 0.5 mm. The potential and current density were monitored all along the cell (70 sensors). The oxygen concentration was also recorded. The experiments were performed with natural sea water, and cathodic protection was applied in a reservoir at one extremity of the cell. Another reservoir at the other cell extremity enabled carbon dioxide bubbling to simulate pipeline annular conditions. PROCOR software was used to simulate potential and current density within the gap and a mathematical model was developed to model oxygen concentration evolution. Both model and experimental results show that the extent of the cathodic protection is much greater than that of oxygen. Oxygen depletion is very quick within the gap when seawater fills it and the oxygen concentration is close to zero a few milli-metres from the gap opening. On the other hand, the cathodic protection

  17. Electrical structure beneath the Hangai Dome, Mongolia, from magnetotelluric data

    Science.gov (United States)

    Comeau, Matthew; Käufl, Johannes; Becken, Michael; Kuvshinov, Alexey; Demberel, Sodnomsambuu; Sukhbaatar, Usnikh; Batmagnai, Erdenechimeg; Tserendug, Shoovdor; Nasan, Ochir

    2017-04-01

    The Hangai Dome in west-central Mongolia is an unusual high-elevation intra-continental plateau located far from tectonic plate boundaries and characterized by dispersed, low-volume, basaltic volcanism. This region is an ideal natural laboratory for studying intra-continental orogenic and magmatic processes resulting from crust-mantle interactions. The processes responsible for developing the Hangai Dome remain unexplained, due in part to a lack of high resolution geophysical data over the area. Here we present newly acquired broadband (0.008 - 3,000 s) magnetotelluric (MT) data from a large-scale ( 200 x 450 km) and high resolution (site spacing > 5 km) survey across the Hangai Dome. A total of 125 sites were collected and include full MT sites and telluric-only sites where inter-station transfer functions were computed. The MT data are used to generate an electrical resistivity model of the crust and upper mantle below the Hangai Dome. The model shows that the lower crust ( 30 - 50 km; below the brittle-ductile transition zone) beneath the Hangai Dome contains anomalous discrete pockets of low-resistivity ( 30 ohm-m) material that indicate the presence of local accumulations of fluids and/or low-percent partial melts. These anomalous regions appear to be spatially associated with the surface expressions of past volcanism, hydrothermal activity, and an increase in heat flow. They also correlate with observed crustal low-density and low-velocity anomalies. However they are in contrast to some geochemical and petrological studies which show long-lived crustal melt storage is impossible below the Hangai due to limited crustal assimilation and crustal contamination, arguing for a single parent-source at mantle depths. The upper mantle ( 6%) at this location. The results are consistent with modern geochemical and geophysical data, which show a thin lithosphere below the Hangai region. Furthermore the results agree with geodynamic models that require a low-heat flux

  18. Dating Metasomatism in the Lithosphere Beneath North China Craton

    Science.gov (United States)

    Chen, L.; Zhou, X.

    2005-12-01

    Dating of mantle metasomatism had been carried out using zircons in metasomatized mantle xenoliths entrained in kimberlites (Kinny and Dawson, 1992; Rudnick et al., 1999; Konzett et al., 1998, 2000; Liati et al., 2004), because the U-Pb system in zircon can remain closed at high temperature (>900-)(Lee et al., 1997). Here we report a SHRIMP U-Pb dating analysis of zircons from a unique dunite-orthopyroxenite xenolith entrained in Cretaceous high-Mg diorite of Shandong province, which provides a timing constraint for the multi-stage metasomatism in the lithosphere beneath North China craton (NCC). Abundant ultramafic xenoliths had been found in the Tietonggou intrusion, one of the Cretaceous high-Mg diorite-dominated plutons in North China (Chen and Zhou, 2004). The lithology, mineral chemistry, equilibrium temperature (690-790A), and metasomatic characteristics of the ultramafic xenoliths indicate that they might be derived from the shallow lithosphere (the crust-mantle transitional zone or the uppermost lithospheric mantle) and had suffered multi-stage metasomatism (Chen and Zhou, 2004, 2005). Xenolith LW0006 is the most extremely metasomatized sample found so far in the xenolith suite of the Tietonggou pluton. The petrography, mineral chemistry, and major element compositions provide a clear metasomatic record of the composite xenolith: K (and/or Ca) metasomatism, and Si (Na) metasomatism (Chen and Zhou). We found seven zircons range from 100-170 Im in longest dimension, which is reflected in the unusually high Zr content of the bulk rock (49 ppm) of this sample. SHRIMP U-Pb dating reveals that these zircons might be grouped three kinds: Mesozoic (concordia age of 127-A3 Ma, 5 zircons), Paleozoic (430-470 Ma, 1 zircon only) and Mesoproterozoic (1310-1540 Ma, 1 zircon only). Cathodoluminescence (CL) images reveal that a few Mesozoic zircons and the Paleozoic zircons retain oscillatory zoning. The Mesozoic zircons are characterized with high Th, U contents and high

  19. Lithospheric Mantle heterogeneities beneath northern Santa Cruz province, Argentina

    Science.gov (United States)

    Mundl, Andrea; Ntaflos, Theodoros; Bjerg, Ernesto

    2013-04-01

    interstitial clinopyroxene appears to be of metasomatic origin. The clinopyroxene from cumulate dunites has depleted LREE abundances and low HREE indicating that they have been formed from residual melts. In contrast, clinopyroxene from mantle dunites has enriched LREE (10 x PM) and LILE suggesting that the metasomatic agent was fluid-rich silicate melt. Calculated equilibrium conditions cover a wide range, from 800 to 1100 °C. Considering the crustal thickness in the area being around 35 km, a pressure between 12 and 17 kbar can be assumed as reasonable, indicating that xenoliths were extracted from shallow depths, in the order of 40 to 60 km. Model calculations have shown that the Lithospheric Mantle beneath Don Camilo is fertile and that spinel peridotites experienced low degrees of partial melting (2-8% batch melting in the spinel peridotite field). The metasomatic agent was a fluid rich silicate melt presumably similar to that which affected the xenoliths from Cerro Clark locality, north of Don Camilo. The clinopyroxenes with the highest Sr and lowest Nd isotopic signatures suggest that the metasomatism was an old event apparently not associated to the interaction of the Lithospheric Mantle in southern Patagonia with downgoing Nazca and Antarctic plates.

  20. Channelling of Melt Above Plumes and Beneath MORs

    Science.gov (United States)

    Mueller, K.; Schmeling, H.

    2003-12-01

    We investigate melt transportation in partially molten rocks under different stress fields above the head of a mantle plume or beneath a spreading mid-oceanic ridge under hydrous and anhydrous conditions. We model such aggregates with the 2D-FD code FDCON [1] by means of a porous deformable matrix with melt under the influence of a given stress field to clarify the following key questions: Could channeling occur in a matrix containing a random melt distribution under a given stress field? Which orientation does it take? Is it possible to achieve a focusing of melt towards a MOR (dykes)? Does applying simple or pure shear to the matrix result in a difference in the formation and orientation of channels? How does the channel instability evolve during finite simple shear? In a deforming partially molten aggregate, weakening of the solid matrix due to the presence of melt creates an instability in which melt is localized by the following mechanism: regions of initially high melt fraction are areas of low viscosity and pressure, so that melt is drawn into these regions from higher pressure surroundings. This further enhances the melt weakening, producing a self-excited localization mechanism [2]. The channeling developing in models with a random melt distribution of 3.5 +/- 0.5% shows that melt is accumulated preferably in inclined channels. For both, simple as well as pure shear, the growth rate is highest for an orientation parallel to the direction of the maximum compressive stress and proportional to applied stress and the reverse of the Melt Retention Number. This also confirms the theoretical growth rate found by Stevenson [2]. In our isothermal models we found that the influence of water reduces the growth rate, in contrast to non-isothermal models of Hall [3]. Under simple shear melt channels evolve from an irregular melt distribution at angles of 45 degrees to the direction of shear. Upon further straining they rotate out of the orientation of maximum growth

  1. Metasomatism in the oceanic lithosphere beneath La Palma, Canary Islands

    Science.gov (United States)

    Janisch, Astrid; Ntaflos, Theodoros

    2016-04-01

    host basalt) indicate that these veins have been formed prior to their transport to the surface. During to their transport to the surface host basalt infiltration propagated along these veins leading to the breakdown of the amphibole and/or phlogopite and the formation of glass, secondary clinopyroxene and spinel. The glass is of tephra-phonolitic composition in the peridotite and foiditic along the amphibole-phlogopite-veins. Mantle xenoliths from San Antonio reveal that the oceanic lithosphere beneath La Palma has been affected by different metasomatic processes. The metasomatic agents were silicate melts causing the formation of secondary clinopyroxenes and the breakdown of orthopyroxenes, whereas hydrous silica fluids formed the various amphibole and/or phlogopite veins-veinlets. Additionally, the presence of a veinlet containing haüyne and glass is a strong indication for host basalt infiltration since these basalts are haüyne bearing.

  2. Mohorovicic discontinuity depth analysis beneath North Patagonian Massif

    Science.gov (United States)

    Gómez Dacal, M. L.; Tocho, C.; Aragón, E.

    2013-05-01

    The North Patagonian Massif is a 100000 km2, sub-rectangular plateau that stands out 500 to 700 m higher in altitude than the surrounding topography. The creation of this plateau took place during the Oligocene through a sudden uplift without noticeable internal deformation. This quite different mechanical response between the massif and the surrounding back arc, the short time in which this process took place and a regional negative Bouguer anomaly in the massif area, raise the question about the isostatic compensation state of the previously mentioned massif. In the present work, a comparison between different results about the depth of the Mohorovicic discontinuity beneath the North Patagonian Massif and a later analysis is made. It has the objective to analyze the crustal thickness in the area to contribute in the determination of the isostatic balance and the better understanding of the Cenozoic evolution of the mentioned area. The comparison is made between four models; two of these were created with seismic information (Feng et al., 2006 and Bassin et al., 2000), another model with gravity information (Barzaghi et al., 2011) and the last one with a combination of both techniques (Tassara y Etchaurren, 2011). The latter was the result of the adaptation to the work area of a three-dimensional density model made with some additional information, mainly seismic, that constrain the surfaces. The work of restriction and adaptation of this model, the later analysis and comparison with the other three models and the combination of both seismic models to cover the lack of resolution in some areas, is presented here. According the different models, the crustal thickness of the study zone would be between 36 and 45 Km. and thicker than the surrounding areas. These results talk us about a crust thicker than normal and that could behave as a rigid and independent block. Moreover, it can be observed that there are noticeable differences between gravimetric and seismic

  3. Upper Mantle Flow Beneath the Subducted Nazca Plate: Slab Contortions and Flattening (Invited)

    Science.gov (United States)

    Russo, R. M.

    2010-12-01

    The form of asthenospheric flow beneath subducted lithospheric slabs can be discerned using splitting of shear waves emanating from earthquakes in the slabs themselves. However, the subducted Nazca plate’s abrupt changes in morphology from a planar slab dipping 30° ENE beneath the central Andes to large areas of flat-lying slab beneath Peru, to the north, and Argentina, to the south, are a potential complication to the sub-slab mantle flow. S waves from earthquakes in the Nazca slab reveal details of the upper mantle flow field below and in the vicinity of the slab. Nazca slab earthquakes large enough to be well recorded (M > 5.4, typically), and deep enough to separate S from pS and sS (30-40 km or more), are suitable for such study, and, for events between 1990 and 2010, recording stations are mostly well-distributed azimuthally about the source event. The S waves were recorded at seismic stations at teleseismic distances from the events, and were corrected for known sub-station seismic anisotropy. Thus, the shear wave splitting engendered during their passage through the asthenospheric upper mantle beneath the slab was isolated, and asthenospheric deformation fabrics resulting from plastic flow beneath the slab mapped in some detail. Shear wave splitting fast directions and upper mantle flow beneath the Nazca plate are most often trench-parallel, consistent with trench-parallel upper mantle flow beneath the slab. Fast splitting polarizations at high angle to the strike of the slab occur in the transition regions from flat to normally dipping slab. Upper mantle flow beneath the slab in these regions appears to be channeled by the slab contortion. Upper mantle flow oceanward of the Nazca slab also appears to change abruptly from trends at a high angle to the Peru-Chile trench to trench-parallel as the top of the Nazca slab attains a depth of around 75 km. Trench-parallel sub-slab flow appears to develop once the asthenosphere beneath the Nazca plate is affected

  4. Seismic evidence for a chemically distinct thermochemical reservoir in Earth's deep mantle beneath Hawaii

    Science.gov (United States)

    Zhao, Chunpeng; Garnero, Edward J.; McNamara, Allen K.; Schmerr, Nicholas; Carlson, Richard W.

    2015-09-01

    Nearly antipodal continent-sized zones of reduced seismic shear wave velocities exist at the base of Earth's mantle, one beneath the Pacific Ocean, the other beneath the South Atlantic Ocean and Africa. Geophysicists have attributed the low velocity zones to elevated temperatures associated with large-scale mantle convection processes, specifically, hot mantle upwelling in response to cooler subduction-related downwelling currents. Hypotheses have included superplumes, isochemical heterogeneity, and stable as well as metastable basal thermochemical piles. Here we analyze waveform broadening and travel times of S waves from 11 deep focus earthquakes in the southwest Pacific recorded in North America, resulting in 8500 seismograms studied that sample the deep mantle beneath the Pacific. Waveform broadening is referenced to a mean S-wave shape constructed for each event, to define a relative "misfit". Large misfits are consistent with multipathing that can broaden wave pulses. Misfits of deep mantle sampling S-waves infer that the structure in the northeast part of the low velocity province beneath the Pacific has a sharp side as well as a sloping sharp top to the feature. This sharp boundary morphology is consistent with geodynamic predictions for a stable thermochemical reservoir. The peak of the imaged pile is below Hawaii, supporting the hypothesis of a whole mantle plume beneath the hotspot.

  5. 计算机系统信息隐藏反取证技术%Data Hiding and Anti-Forensic on Modern Computer System

    Institute of Scientific and Technical Information of China (English)

    李佟鸿; 王宁; 刘志军

    2013-01-01

    研究了现代计算机系统信息隐藏的各种可能方式.运用HPA和DCO、隐藏分区等技术分析了磁盘驱动的数据隐藏,运用簇分配、Slack空间等技术分析了NTFS文件系统的各种信息隐藏方法,以及各种方法可能的检测手段.分析各种隐藏技术作为计算机反取证手段,给计算机取证带来的巨大影响.%This paper discusses some of the possible ways to hide data on modern computer systems.Using HPA and DCO,hidden partition and other technical analysis of the disk drive data hidden.Using the cluster distribution,Slack space and so on technical discusses some of the methods that can be used to hide data in NTFS and analysis techniques that can be used to detect and recover hidden data.The exploration of the different hiding technology can be used as computer anti-forensics means,to the great impacts of computer forensics.

  6. Digital image hiding technology based on information%基于数字图像的信息隐藏技术探究

    Institute of Scientific and Technical Information of China (English)

    任师迁

    2013-01-01

    In the process of information society,information has become an important resource for social development.With the rapid development of Internet,more and more information is transmitted through the network,the confidentiality,authenticity,the integrity of the information has become a research focus. Introduces the technologies of information hiding in the image concept,classification and development of information hiding technology,vector quantization is analyzed in detail,and points out the development trend of information hiding technology.%  在社会信息化的进程中,信息已经成为社会发展的重要资源。随着互联网的快速发展,越来越多的信息通过网络进行传播,信息的保密性、真实性、完整性逐渐成为研究焦点。介绍了图像中信息隐藏技术的概念、分类和发展,对矢量量化信息隐藏技术进行了重点分析,指出了信息隐藏技术的发展趋势。

  7. An eco-friendly method for short term preservation of skins/hides using Semecarpus anacardium nut extract.

    Science.gov (United States)

    Iyappan, Kuttalam; Ponrasu, Thangavel; Sangeethapriya, Vilvanathan; Gayathri, Vinaya Subramani; Suguna, Lonchin

    2013-09-01

    Preservation or curing of hides and skins is performed as the primary step of leather processing. Common salt is employed as the conventional agent for curing purpose. Use of salt enhances the pollution load of tannery effluent which becomes highly contaminated with increased total dissolved solids and chlorides. To overcome this hurdle, researchers are in constant search of alternative preservation techniques which are either totally void of salt or use only a meager amount of salt. In the present study, we had explored the possibility of using Semecarpus anacardium nut extract as an alternative to salt for the curing process by assessing different parameters like hair slip, putrefaction odor, volatile nitrogen content, moisture content, bacterial count, and shrinkage temperature in comparison to the salt curing method. The antibacterial property of the plant extract was also investigated. The results obtained substantiated that the nut extract of S. anacardium effectively could preserve the skins for more than a month, by its antibacterial activity along with the dehydrating property of acetone.

  8. Can organic matter hide from decomposers in the labyrinth of soil aggregates? Micro-engineered Soil Chips challenging foraging fungi

    Science.gov (United States)

    Hammer, Edith C.; Aleklett, Kristin; Arellano Caicedo, Carlos G.; Bengtsson, Martin; Micaela Mafla Endara, Paola; Ohlsson, Pelle

    2017-04-01

    From the point of view of microorganisms, the soil environment is an enormously complex labyrinth with paths and dead-end streets, where resources and shelters are unevenly distributed. We study foraging strategies of soil organisms, especially fungi, and the possibility of physio-spatial stabilization of organic matter by "hiding" in occluded soil spaces. We manipulate growth habitat microstructure with lab-on-a-chip techniques, where we designed complex environments with channels and obstacle at dimensions of the size of hyphae, and construct them in the transparent, gas-permeable polymer PDMS. We fill those with different nutrient solutions or combine with mineral nutrient gradients, and inoculate them with soil organisms. We analyze organisms and substrates with microscopy, fluorescence microscopy and analytical chemistry. We compared different soil litter decomposers and an arbuscular mycorrhizal fungus for their ability to forage through complex air-gap structures and attempt to classify them into functional traits concerning their mycelium directionality, space-exploring approach and ability to grow through acute angles and narrow constrictions. We identified structures which are very difficult to penetrate for most species, and compounds located behind such features may thus be spatially unavailable for decomposers. We discuss our approach in comparison to soil pore space tomographic analyses and findings we made in the pore space of colonized wood biochar.

  9. 'Hide-then-hit' to explain the importance of genotypic polymorphism of DNA repair genes in determining susceptibility to cancer

    Institute of Scientific and Technical Information of China (English)

    Pei-Ei Wu; Chen-Yang Shen

    2011-01-01

    Interindividual variations in DNA repair capacity/efficiency linked to the presence of polymorphisms in DNA repair-related genes have been suggested to account for different risk of developing cancers. In this review article, on the basis of breast cancer formation as a model, we propose a 'hide-then-hit' hypothesis indicating the importance of escaping checkpoint surveillance for sub-optimal DNA repair variants to cause cancer. Therefore, only cells with subtle defects in repair capacity arising from low-penetrance variants of DNA repair genes would have the opportunity to grow and accumulate the genetic changes needed for cancer formation, without triggering cell-cycle checkpoint surveillance. Furthermore, distinct from high-penetrance alleles, these polymorphic alleles of DNA repair genes would predispose carriers to a higher risk of developing cancer but would not necessarily cause cancer. To examine this,we simultaneously genotyped multiple SNPs of cell-cycle checkpoint genes and the DNA repair genes. Support for the hypothesis came from observations that breast cancer risk associated with variant genotypes of DNA repair genes became more significant in be confirmed by biological evidence in which a cause-effect relationship has to be established. However, based on this, possible gene-gene interaction is considered to play an important role in modifying the cancer risk associated with genotypic polymorphism of DNA repair gene in different study populations.

  10. Hybrid Data Hiding Scheme Using Right-Most Digit Replacement and Adaptive Least Significant Bit for Digital Images

    Directory of Open Access Journals (Sweden)

    Mehdi Hussain

    2016-05-01

    Full Text Available The goal of image steganographic methods considers three main key issues: high embedding capacity, good visual symmetry/quality, and security. In this paper, a hybrid data hiding method combining the right-most digit replacement (RMDR with an adaptive least significant bit (ALSB is proposed to provide not only high embedding capacity but also maintain a good visual symmetry. The cover-image is divided into lower texture (symmetry patterns and higher texture (asymmetry patterns areas and these textures determine the selection of RMDR and ALSB methods, respectively, according to pixel symmetry. This paper has three major contributions. First, the proposed hybrid method enhanced the embedding capacity due to efficient ALSB utilization in the higher texture areas of cover images. Second, the proposed hybrid method maintains the high visual quality because RMDR has the closest selection process to generate the symmetry between stego and cover pixels. Finally, the proposed hybrid method is secure against statistical regular or singular (RS steganalysis and pixel difference histogram steganalysis because RMDR is capable of evading the risk of RS detection attacks due to pixel digits replacement instead of bits. Extensive experimental tests (over 1500+ cover images are conducted with recent least significant bit (LSB-based hybrid methods and it is demonstrated that the proposed hybrid method has a high embedding capacity (800,019 bits while maintaining good visual symmetry (39.00% peak signal-to-noise ratio (PSNR.

  11. A Novel Steganography Method for Hiding BW Images into Gray Bitmap Images via k-Modulus Method

    Directory of Open Access Journals (Sweden)

    Firas A. Jassim

    2013-09-01

    Full Text Available This paper is to create a pragmatic steganographic implementation to hide black and white image which is known as stego image inside another gray bitmap image that known as cover image. First of all, the proposed technique uses k-Modulus Method (K-MM to convert all pixels within the cover image into multiples of positive integer named k. Since the black and white images can be represented using binary representation, i.e. 0 or 1. Then, in this article, the suitable value for the positive integer k is two. Therefore, each pixel inside the cover image is divisible by two and this produces a reminder which is either 0 or 1. Subsequently, the black and white representation of the stego image could be hidden inside the cover image. The ocular differences between the cover image before and after adding the stego image are insignificant. The experimental results show that the PSNR values for the cover image are very high with very small Mean Square Error.

  12. Bovine viral diarrhea virus antigen detection across whole cattle hides using two antigen-capture enzyme-linked immunosorbent assays.

    Science.gov (United States)

    Vander Ley, Brian L; Ridpath, Julia F; Sweiger, Shaun H

    2012-05-01

    Bovine viral diarrhea virus is a costly disease of cattle that can be controlled by vaccination, biosecurity, and removal of persistently infected cattle. Development and proficiency testing of assays to identify persistently infected cattle requires substantial quantities of known positive- and negative-sample material. The objective of this study was to determine what sections of bovine skin contained Bovine viral diarrhea virus antigen. Two commercially available antigen-capture enzyme-linked immunoassays were used to test subsamples representing the entire skin of 3 persistently infected calves. Both assays detected Bovine viral diarrhea virus antigen in the samples indicated for use by assay protocol. However, one assay identified all subsamples as positive, while the second assay identified 64.4% of subsamples as positive. These results show that use of samples other than those specified by the assay protocol must be validated for each individual assay. In this study, alternative sample sites and use of the entire hide for proficiency testing would be acceptable for only one of the assays tested.

  13. Purification and Partial Characterization of a Collagenolytic Enzyme Produced by Pseudomonas aeraginosa SCU Screened from Rotten Hides

    Institute of Scientific and Technical Information of China (English)

    Yang Guangyao(杨光垚); Zhang Yizheng

    2004-01-01

    Strain Pseudomonas Aeraginosa SCU isolated from rotten hides is shown to produce various gelatinolytic enzymes with molecular masses ranging from ~50 to ~200 kD. A gelatinolytic enzyme called PAC exhibiting collagenolytic activity is purified by SP sepharose fast flow, Sephadex G-200 gel filtration and native PAGE cutting method. The purified enzyme has an apparent molecular weight of about 110 kD by SDS PAGE without β-mercaptoethanol. Treatment withβ-Me suggests that PAC is dissociated into three subunits approximately 33 kD,25 kD and 20 kD with a ratio of 2∶1∶1, named sub A, sub B and sub C repectively. EDTA and EGTA display a significant inhibitory effect on the enzyme activity while PMSF, leupeptin and pepstain do not appreciably inhibit it. The first 15 amino acid residues of the major subunit (subA) are determined and the sequence is Ala-Glu-Ala-Gly-Gly-Pro-Gly-Gly-Asn-Gln-Lys-Ile-Gly -Lys-Tyr. This sequence is identical to that of elastase of P.aeruginosa. The fragment of encoding mature sub A is cloned and its sequence is determined, which has a high homology with the gene of elastase. These results indicate that PAC is a novel collagenolytic metalloprotease composed of three kinds of subunits, of which elastase is the major one.

  14. Seismic evidence for a crustal magma reservoir beneath the upper east rift zoneof Kilauea volcano, Hawaii

    Science.gov (United States)

    Lin, Guoqing; Amelung, Falk; Lavallee, Yan; Okubo, Paul G.

    2014-01-01

    An anomalous body with low Vp (compressional wave velocity), low Vs (shear wave velocity), and high Vp/Vs anomalies is observed at 8–11 km depth beneath the upper east rift zone of Kilauea volcano in Hawaii by simultaneous inversion of seismic velocity structure and earthquake locations. We interpret this body to be a crustal magma reservoir beneath the volcanic pile, similar to those widely recognized beneath mid-ocean ridge volcanoes. Combined seismic velocity and petrophysical models suggest the presence of 10% melt in a cumulate magma mush. This reservoir could have supplied the magma that intruded into the deep section of the east rift zone and caused its rapid expansion following the 1975 M7.2 Kalapana earthquake.

  15. Microfungi in the soil beneath common oak and their effect on Armillaria occurrence

    Directory of Open Access Journals (Sweden)

    Hanna Kwaśna

    2014-08-01

    Full Text Available Microfungal assemblages in a soil beneath 30- and 50·year-old oaks and their 2-year-old stumps were studied using the soil dilution plate method. A total of 98 culturable microfungi were isolated. Compared to the living oaks before felling and the control living oaks, the density of Mortierella macrocystis, Penicillium jonczewskii, Pseudogymnoascus roseus Sporothrix schenckii, Tolypoccladiumum inflatum and Umbelopsis vinacea sigificantly inacased in the soil beneath slumps in the 32- and 52-year-old stands. Density of Aspergillus kanagawaensis, Monodictys lepraria, P. daleae and sterile dematiaceous hyphomycetes increased significantly in the 32-year-old stand and Chrysosporium merdarium in the 52·year-old stand. These fungi are known 'stimulants' of Armillaria rhizomorph formation. It is suggested that the increase in density of Armillaria rhizomorph 'stimulants' in a soil beneath oak stumps may increase the possibility of colonization of stumps by Armillaria.

  16. Simulation of Wave-Plus-Current Induced Scour Beneath Submarine Pipelines

    DEFF Research Database (Denmark)

    Eltard-Larsen, Bjarke; Fuhrman, David R.; Sumer, B. Mutlu

    of combined wave-plus-current scour processes beneath pipelines. The results of 77 simulated wave-plus-current scour cases will be presented and analysed. The cases considered will consist of waves characterized by 10 different Keulegan-Carpenter numbers, KC=UmTw/D and up to eight different values of m......-plus-current environments. The present study, which is published in Larsen et al. (2016) focuses on the numerical simulation of wave-plus-current induced scour beneath submarine pipelines, based on a model solving Reynolds-averaged Navier-Stokes (RANS) equations, fully coupled with turbulence closure, bed and suspended...... load sediment transport descriptions, and a seabed morphological model. The model was utilized in simulating breaker bar development by Jacobsen et al. (2014) and has been used in simulating wave induced scour beneath pipelines by Fuhrman et al. (2014) . The model is utilized for the numerical study...

  17. Subsurface imaging reveals a confined aquifer beneath an ice-sealed Antarctic lake

    DEFF Research Database (Denmark)

    Dugan, H. A.; Doran, P. T.; Tulaczyk, S.;

    2015-01-01

    Liquid water oases are rare under extreme cold desert conditions found in the Antarctic McMurdo Dry Valleys. Here we report geophysical results that indicate that Lake Vida, one of the largest lakes in the region, is nearly frozen and underlain by widespread cryoconcentrated brine. A ground...... Geophysical survey finds low resistivities beneath a lake in Antarctic Dry Valleys Liquid brine abundant beneath Antarctic lake Aquifer provides microbial refugium in cold desert environment...... penetrating radar survey profiled 20 m into lake ice and facilitated bathymetric mapping of the upper lake basin. An airborne transient electromagnetic survey revealed a low-resistivity zone 30-100 m beneath the lake surface. Based on previous knowledge of brine chemistry and local geology, we interpret...

  18. A New Information Hiding Way Based on Word XML%一种基于Word XML的信息隐藏新方法

    Institute of Scientific and Technical Information of China (English)

    董艳; 徐江峰

    2015-01-01

    It is of great significance to hide some secret information in a Word document. Based on analyzing the"revision identifiers" in document. xml of Word 2007 document, propose a new information hiding method. According to a pseudo-random binary sequence which is produced by logistic pseudo-random sequence generator,extract certain attributes of"revision identifiers" in document. xml,and change the last six attributes values with the hexadecimal secret information,achieving the purpose of hiding secret information. The ex-perimental result show that compared with the previous hiding ways based on Word,the new hiding way based on the "revision identi-fiers" is better in robustness and safety and so on.%在应用广泛的Word文档中隐藏秘密信息意义巨大,在对Word 2007中document. xml文件的“修改标识”特性分析的基础上,提出了一种的新的信息隐藏方法。该方法首先根据logistic方程伪随机序列生成器产生的伪随机二进制序列,去抽取载体文件document. xml中特定的“修改标识”属性值,而后用秘密信息的十六进制码替换抽取的属性值后六位,从而达到隐藏秘密信息的目的。实验结果表明,基于document. xml文件中“修改标识”属性值的信息隐藏新方法,与既有的基于Word的信息隐藏方法相比,具有安全性更高、隐蔽性更强等优点。

  19. Authenticity of identification and processing experience of donkey hide gelatin%阿胶的真伪鉴别以及炮制经验

    Institute of Scientific and Technical Information of China (English)

    张萍

    2015-01-01

    阿胶是有改善男女生育、调节月经、恢复元气等功效,能够促进造血功能,升高白细胞,提高自身免疫力等功能,对免疫力低下患者或癌症患者有着重要的作用,还可以促进凝血和降低血管通透性,提高对钙的吸收,预防骨质疏松疾病,是骨折患者较佳的补品。由于阿胶的应用范围较广,有些不法商贩弄虚作假,严重扰乱了阿胶市场,给消费者带来了较大伤害,因此,掌握阿胶的真伪鉴别方法至关重要,本文对阿胶的真伪鉴别以及炮制经验进行总结。%Donkey hide gelatin has the function of improving male and female fertility,regulating menstruation,recovering vitality and so on.It can promote the hematopoietic function,elevate the white blood cells,improve the autoimmunity,and it plays an important role on the immunocompromised patients or cancer patients.On the side,it can promote coagulation and reduce vascular permeability,enhance the absorption of calcium,prevent osteoporosis.It is a better tonic for patients with fracture.Because the application range of donkey hide gelatin is wide,some unscrupulous traders have falsification and seriously disrupte the donkey hide gelatin market to bring a greater harm on consumers.Therefore,it is great importance to grasp the authenticity of identification method of donkey hide gelatin.In this paper,the author summarizes the authenticity of identification and processing experience of donkey hide gelatin.

  20. Crust and upper mantle electrical conductivity beneath the Yellowstone Hotspot Track

    Science.gov (United States)

    Kelbert, A.; Egbert, G. D.

    2012-12-01

    We have used high-quality electromagnetic data obtained through the EarthScope USArray project to obtain detailed three-dimensional images of electrical resistivity / conductivity in the crust and upper mantle beneath the Snake River Plain/Yellowstone (SRP/Y) volcanic province (Idaho and Wyoming, United States). The lowest resistivities in the area can only plausibly be explained by partial melt and/or fluids, providing valuable new information about the distribution of these phases deep within the Earth beneath the volcanic system. Unexpectedly, in light of the mantle plume models often used to explain Yellowstone volcanism, the electromagnetic data imply that there is no interconnected melt in the lower crust and uppermost mantle directly beneath the modern Yellowstone caldera. Instead, low resistivities consistent with 1-3% melt in the uppermost mantle (depths of 40-80 km) extend at least 200 km southwest of Yellowstone. Shallower areas of reduced resistivity extend upward into the mid-crust around the edges of the seemingly impermeable Snake River Plain province, including beneath Yellowstone. We suggest that the elevated temperatures beneath the active volcanic center have resulted in greater permeability, allowing magma to ascend to shallower depths and pool in the crust. Little melt is entering the system from below at present, perhaps due to intermittency of supply. We describe these results in the context of larger scale electrical resistivity and seismic tomography models of the western US and employ joint interpretation to formulate hypotheses that would explain this unexpected melt distribution beneath the SRP/Y. Our 3-D model is available at http://www.iris.edu/dms/products/emc/models/SRPY-MT.htm

  1. Mantle seismic anisotropy beneath NE China and implications for the lithospheric delamination hypothesis beneath the southern Great Xing'an range

    Science.gov (United States)

    Chen, Haichao; Niu, Fenglin; Obayashi, Masayuki; Grand, Stephen P.; Kawakatsu, Hitoshi; John Chen, Y.; Ning, Jieyuan; Tanaka, Satoru

    2017-08-01

    We measured shear wave splitting from SKS data recorded by the transcontinental NECESSArray in NE China to constrain lithosphere deformation and sublithospheric flows beneath the area. We selected several hundreds of high quality SKS/SKKS waveforms from 32 teleseismic earthquakes occurring between 09/01/2009 and 08/31/2011 recorded by 125 broadband stations. These stations cover a variety of tectonic terranes, including the Songliao basin, the Changbaishan mountain range and Zhangguancai range in the east, the Great Xing'an range in the west and the Yanshan orogenic belt in the southwest. We assumed each station is underlaid by a single anisotropic layer and employed a signal-to-noise ratio (SNR) weighted multi-event stacking method to estimate the two splitting parameters (the fast polarization direction φ, and delay time, δt) that gives the best fit to all the SKS/SKKS waveforms recorded at each station. Overall, the measured fast polarization direction lies more or less along the NW-SE direction, which significantly differs from the absolute plate motion direction, but is roughly consistent with the regional extension direction. This suggests that lithosphere deformation is likely the general cause of the observed seismic anisotropy. The most complicated anisotropic structure is observed beneath the southern Great Xing'an range and southwest Songliao basin. The observed large variations in splitting parameters and the seismic tomographic images of the area are consistent with ongoing lithospheric delamination beneath this region.

  2. Big mantle wedge, anisotropy, slabs and earthquakes beneath the Japan Sea

    Science.gov (United States)

    Zhao, Dapeng

    2017-09-01

    The Japan Sea is a part of the western Pacific trench-arc-backarc system and has a complex bathymetry and intense seismic activities in the crust and upper mantle. Local seismic tomography revealed strong lateral heterogeneities in the crust and uppermost mantle beneath the eastern margin of the Japan Sea, which was determined using P and S wave arrival times of suboceanic earthquakes relocated precisely with sP depth phases. Ambient-noise tomography revealed a thin crust and a thin lithosphere beneath the Japan Sea and significant low-velocity (low-V) anomalies in the shallow mantle beneath the western and eastern margins of the Japan Sea. Observations with ocean-bottom seismometers and electromagnetometers revealed low-V and high-conductivity anomalies at depths of 200-300 km in the big mantle wedge (BMW) above the subducting Pacific slab, and the anomalies are connected with the low-V zone in the normal mantle wedge beneath NE Japan, suggesting that both shallow and deep slab dehydrations occur and contribute to the arc and back-arc magmatism. The Pacific slab has a simple geometry beneath the Japan Sea, and earthquakes occur actively in the slab down to a depth of ∼600 km beneath the NE Asian margin. Teleseismic P and S wave tomography has revealed that the Philippine Sea plate has subducted aseismically down to the mantle transition zone (MTZ, 410-660 km) depths beneath the southern Japan Sea and the Tsushima Strait, and a slab window is revealed within the aseismic Philippine Sea slab. Seismic anisotropy tomography revealed a NW-SE fast-velocity direction in the BMW, which reflects corner flows induced by the fast deep subduction of the Pacific slab. Large deep earthquakes (M > 7.0; depth > 500 km) occur frequently beneath the Japan Sea western margin, which may be related to the formation of the Changbai and Ulleung intraplate volcanoes. A metastable olivine wedge is revealed within the cold core of the Pacific slab at the MTZ depth, which may be related

  3. Seismic Imaging of the crust and upper mantle beneath Afar, Ethiopia

    Science.gov (United States)

    Hammond, J. O.; Kendall, J. M.; Stuart, G. W.; Ebinger, C. J.

    2009-12-01

    In March 2007 41 seismic stations were deployed in north east Ethiopia. These stations recorded until October 2009, whereupon the array was condensed to 13 stations. Here we show estimates of crustal structure derived from receiver functions and upper mantle velocity structure, derived from tomography and shear-wave splitting using the first 2.5 years of data. Bulk crustal structure has been determined by H-k stacking receiver functions. Crustal Thickness varies from ~45km on the rift margins to ~16km beneath the northeastern Afar stations. Estimates of Vp/Vs show normal continental crust values (1.7-1.8) on the rift margins, and very high values (2.0-2.2) in Afar, similar to results for the Main Ethiopian Rift (MER). This supports ideas of high levels of melt in the crust beneath the Ethiopian Rift. Additionally, we use a common conversion point migration technique to obtain high resolution images of crustal structure beneath the region. Both techniques show a linear region of thin crust (~16km) trending north-south, the same trend as the Red Sea rift. SKS-wave splitting results show a general north east-south west fast direction in the MER, systematically rotating to a more north-south fast direction towards the Red Sea. Additionally, stations close to the recent Dabbahu diking episode show sharp lateral changes over small lateral distances (40° over Danakil microplate. Outside of these focused regions the velocities are relatively fast. Below ~250km the anomaly broadens to cover most of the Afar region with only the rift margins remaining fast. At transition zone depths little anomaly is seen beneath Afar, but some low velocities remain present beneath the MER. These studies suggest that in northern Ethiopia the Red Sea rift is dominant. The presence of thin crust beneath northern Afar suggests that the Red Sea rift is creating oceanic like crust in this region. The lack of deep mantle low velocity anomalies beneath Afar suggest that a typical narrow conduit

  4. Subducted slabs beneath the eastern Indonesia-Tonga region: insights from tomography

    Science.gov (United States)

    Hall, Robert; Spakman, Wim

    2002-07-01

    Tomographic images of mantle structure beneath the region north and northeast of Australia show a number of anomalously fast regions. These are interpreted using a recent plate tectonic reconstruction in terms of current and former subduction systems. Several strong anomalies are related to current subduction. The inferred slab lengths and positions are consistent with Neogene subduction beneath the New Britain and Halmahera arcs, and at the Tonga and the New Hebrides trenches where there has been rapid rollback of subduction hinges since about 10 Ma. There are several deeper flat-lying anomalies which are not related to present subduction and we interpret them as former subduction zones overridden by Australia since 25 Ma. Beneath the Bird's Head and Arafura Sea is an anomaly interpreted to be due to north-dipping subduction beneath the Philippines-Halmahera arc between 45 and 25 Ma. A very large anomaly extending from the Papuan peninsula to the New Hebrides, and from the Solomon Islands to the east Australian margin, is interpreted to be the remnant of south-dipping subduction beneath the Melanesian arc between 45 and 25 Ma. This interpretation implies that a flat-lying slab can survive for many tens of millions of years at the bottom of the upper mantle. In the lower mantle there is a huge anomaly beneath the Gulf of Carpentaria and east Papua New Guinea. This is located above the position where the tectonic model interprets a change in polarity of subduction from north-dipping to south-dipping between 45 and 25 Ma. We suggest this deep anomaly may be a slab subducted beneath eastern Australian during the Cretaceous, or subducted north of Australia during the Cenozoic before 45 Ma. The tomography also supports the tectonic interpretation which suggests little Neogene subduction beneath western New Guinea since no slab is imaged south of the New Guinea trench. However, one subduction zone in the tectonic model and many others, that associated with the Trobriand

  5. Receiver Function Analysis of the Lithospheric Structure Beneath the Western Great Plains

    Science.gov (United States)

    Thurner, S.; Zhai, Y.; Levander, A.

    2010-12-01

    The lithosphere in the western Great Plain region of the Southwestern U.S. has been subject to tectonic deformation from the Proterozoic to present day. Proterozoic island arc terranes accreted onto the North American continent between 1.8 and 1.1 Ga, forming the original continent, and there is evidence for Proterozoic continental extension which formed basement penetrating faults between 1.5 and .6 Ga . This was followed by the uplift of the Ancestral Rockies and, most recently, the subduction of the Farallon plate beneath North America. Extension has occurred throughout the Basin and Range and formed the Rio Grand Rift (RGR). However, the relative impact that large scale tectonic forces, regional asthenospheric upwelling, and preexisting structural weaknesses have on the extension of the RGR is still undetermined. This study seeks to better understand the current tectonic system east of the Colorado Plateau beneath the RGR and western Great Plains. We use teleseismic receiver functions to investigate the nature of extension in the RGR as well as its connection to the small-scale convection thought to be occurring beneath the Colorado Plateau-RGR-Great Plains region. Our receiver function images were generated from 85 earthquake events recorded at 187 USArray Transportable Array seismic stations located throughout the western Great Plains (Latitude: 28-48, Longitude: -105-100). Previous studies have indicated crustal thickness between 39 km and 50 km beneath the Great Plains and as thin as 35 km beneath the RGR (Wilson et.al, 2005). Tomography results have shown high velocity anomalies on both sides of the RGR, extending to 600 km depth beneath the western Great Plains, and a low velocity anomaly directly beneath the RGR (Gok et. al, 2003, Wilson et. al, 2005, Gao et. al, Song and Helmberger, 2007). The western Great Plains high velocity anomaly has been interpreted to be part of the downwelling portion of an edge driven convection system induced by a lateral

  6. Seismic imaging of a mid-lithospheric discontinuity beneath Ontong Java Plateau

    Science.gov (United States)

    Tharimena, Saikiran; Rychert, Catherine A.; Harmon, Nicholas

    2016-09-01

    Ontong Java Plateau (OJP) is a huge, completely submerged volcanic edifice that is hypothesized to have formed during large plume melting events ∼90 and 120 My ago. It is currently resisting subduction into the North Solomon trench. The size and buoyancy of the plateau along with its history of plume melting and current interaction with a subduction zone are all similar to the characteristics and hypothesized mechanisms of continent formation. However, the plateau is remote, and enigmatic, and its proto-continent potential is debated. We use SS precursors to image seismic discontinuity structure beneath Ontong Java Plateau. We image a velocity increase with depth at 28 ± 4 km consistent with the Moho. In addition, we image velocity decreases at 80 ± 5 km and 282 ± 7 km depth. Discontinuities at 60-100 km depth are frequently observed both beneath the oceans and the continents. However, the discontinuity at 282 km is anomalous in comparison to surrounding oceanic regions; in the context of previous results it may suggest a thick viscous root beneath OJP. If such a root exists, then the discontinuity at 80 km bears some similarity to the mid-lithospheric discontinuities (MLDs) observed beneath continents. One possibility is that plume melting events, similar to that which formed OJP, may cause discontinuities in the MLD depth range. Plume-plate interaction could be a mechanism for MLD formation in some continents in the Archean prior to the onset of subduction.

  7. Improved quality of beneath-canopy grass in South African savannas: Local and seasonal variation

    NARCIS (Netherlands)

    Treydte, A.C.; Looringh van Beeck, F.A.; Ludwig, F.; Heitkonig, I.M.A.

    2008-01-01

    Questions: Do large trees improve the nutrient content and the structure of the grass layer in savannas? Does the magnitude of this improvement differ with locality ( soil nutrients) and season ( water availability)? Are grass structure and species composition beneath tree canopies influenced by

  8. Recharge Rates and Chemistry Beneath Playas of the High Plains Aquifer - A Literature Review and Synthesis

    Science.gov (United States)

    Gurdak, Jason J.; Roe, Cassia D.

    2009-01-01

    Playas are ephemeral, closed-basin wetlands that are important zones of recharge to the High Plains (or Ogallala) aquifer and critical habitat for birds and other wildlife in the otherwise semiarid, shortgrass prairie and agricultural landscape. The ephemeral nature of playas, low regional recharge rates, and a strong reliance on ground water from the High Plains aquifer has prompted many questions regarding the contribution of recharge from playas to the regional aquifer. To address these questions and concerns, the U.S. Geological Survey, in cooperation with the Playa Lakes Joint Venture, present a review and synthesis of the more than 175 publications about recharge rates and chemistry beneath playas and interplaya settings. Although a number of questions remain regarding the controls on recharge rates and chemistry beneath playas, the results from most published studies indicate that recharge rates beneath playas are substantially (1 to 2 orders of magnitude) higher than recharge rates beneath interplaya settings. The synthesis presented here supports the conceptual model that playas are important zones of recharge to the High Plains aquifer and are not strictly evaporative pans. The major findings of this synthesis yield science-based implications for the protection and management of playas and ground-water resources of the High Plains aquifer and directions for future research.

  9. Mantle structure beneath Indonesia inferred from high-resolution tomographic imaging

    NARCIS (Netherlands)

    Widiyantoro, Sri; Hilst, R.D. van der

    1997-01-01

    We investigated mantle structure beneath the Indonesian region by means of tomographic inversions of traveltime residuals of direct P and the surface-reflected depth phases pP and pwP. The hypocentres and phase data used in the inversions were derived from the reprocessing of data reported to intern

  10. Tectonic implications of tomographic images of subducted lithosphere beneath northwestern South America

    NARCIS (Netherlands)

    Hilst, R.D. van der; Mann, P.

    1994-01-01

    We used seismic tomography to investigate the complex structure of the upper mantle below northwestern South America. Images of slab structure not delineated by previous seismicity studies help us to refine existing tectonic models of subducted Caribbean-Pacific lithosphere beneath the study area. B

  11. Depth variations of P-wave azimuthal anisotropy beneath Mainland China.

    Science.gov (United States)

    Wei, Wei; Zhao, Dapeng; Xu, Jiandong; Zhou, Bengang; Shi, Yaolin

    2016-07-19

    A high-resolution model of P-wave anisotropic tomography beneath Mainland China and surrounding regions is determined using a large number of arrival-time data recorded by the China seismic network, the International Seismological Centre (ISC) and temporary seismic arrays deployed on the Tibetan Plateau. Our results provide important new insights into the subducted Indian plate and mantle dynamics in East Asia. Our tomographic images show that the northern limit of the subducting Indian plate has reached the Jinsha River suture in eastern Tibet. A striking variation of P-wave azimuthal anisotropy is revealed in the Indian lithosphere: the fast velocity direction (FVD) is NE-SW beneath the Indian continent, whereas the FVD is arc parallel beneath the Himalaya and Tibetan Plateau, which may reflect re-orientation of minerals due to lithospheric extension, in response to the India-Eurasia collision. There are multiple anisotropic layers with variable FVDs in some parts of the Tibetan Plateau, which may be the cause of the dominant null splitting measurements in these regions. A circular pattern of FVDs is revealed around the Philippine Sea slab beneath SE China, which reflects asthenospheric strain caused by toroidal mantle flow around the edge of the subducting slab.

  12. S-wave attenuation structure beneath the northern Izu-Bonin arc

    Science.gov (United States)

    Takahashi, Tsutomu; Obana, Koichiro; Kodaira, Shuichi

    2016-04-01

    To understand temperature structure or magma distribution in the crust and uppermost mantle, it is essential to know their attenuation structure. This study estimated the 3-D S-wave attenuation structure in the crust and uppermost mantle at the northern Izu-Bonin arc, taking into account the apparent attenuation due to multiple forward scattering. In the uppermost mantle, two areas of high seismic attenuation (high Q -1) imaged beneath the volcanic front were mostly colocated with low-velocity anomalies. This coincidence suggests that these high- Q -1 areas in low-velocity zones are the most likely candidates for high-temperature regions beneath volcanoes. The distribution of random inhomogeneities indicated the presence of three anomalies beneath the volcanic front: Two were in high- Q -1 areas but the third was in a moderate- Q -1 area, indicating a low correlation between random inhomogeneities and Q -1. All three anomalies of random inhomogeneities were rich in short-wavelength spectra. The most probable interpretation of such spectra is the presence of volcanic rock, which would be related to accumulated magma intrusion during episodes of volcanic activity. Therefore, the different distributions of Q -1 and random inhomogeneities imply that the positions of hot regions in the uppermost mantle beneath this arc have changed temporally; therefore, they may provide important constraints on the evolutionary processes of arc crust and volcanoes.

  13. The upper mantle beneath the Gulf of California from surface wave dispersion. Geologica Ultraiectina (299)

    NARCIS (Netherlands)

    Zhang, X.|info:eu-repo/dai/nl/304835773

    2009-01-01

    This thesis is a study on upper mantle shear velocity structure beneath the Gulf of California. Surface wave interstation dispersion data were measured in the Gulf of California area and vicinity to obtain a 3-D shear velocity structure of the upper mantle. This work has particular significance for

  14. The upper mantle beneath the Gulf of California from surface wave dispersion. Geologica Ultraiectina (299)

    NARCIS (Netherlands)

    Zhang, X.

    2009-01-01

    This thesis is a study on upper mantle shear velocity structure beneath the Gulf of California. Surface wave interstation dispersion data were measured in the Gulf of California area and vicinity to obtain a 3-D shear velocity structure of the upper mantle. This work has particular significance for

  15. The crustal structure beneath the Netherlands inferred from ambient seismic noise

    NARCIS (Netherlands)

    Yudistira, T.

    2015-01-01

    A 3-D shear velocity model of the crust beneath the Netherlands is determined from fundamental mode Rayleigh and Love wave group measurements derived from ambient seismic noise recordings. The data are obtained from a temporary array of broad-band seismometers in and around the Netherlands (the NARS

  16. Constraining the crustal root geometry beneath the Rif Cordillera (North Morocco)

    Science.gov (United States)

    Diaz, Jordi; Gil, Alba; Carbonell, Ramon; Gallart, Josep; Harnafi, Mimoun

    2016-04-01

    The analyses of wide-angle reflections of controlled source experiments and receiver functions calculated from teleseismic events provide consistent constraints of an over-thickened crust beneath the Rif Cordillera (North Morocco). Regarding active source data, we investigate now offline arrivals of Moho-reflected phases recorded in RIFSIS project to get new estimations of 3D crustal thickness variations beneath North Morocco. Additional constrains on the onshore-offshore transition are derived from onland recording of marine airgun shots from the coeval Gassis-Topomed profiles. A regional crustal thickness map is computed from all these results. In parallel, we use natural seismicity data collected throughout TopoIberia and PICASSO experiments, and from a new RIFSIS deployment, to obtain teleseismic receiver functions and explore the crustal thickness variations with a H-κ grid-search approach. The use of a larger dataset including new stations covering the complex areas beneath the Rif Cordillera allow us to improve the resolution of previous contributions, revealing abrupt crustal changes beneath the region. A gridded surface is built up by interpolating the Moho depths inferred for each seismic station, then compared with the map from controlled source experiments. A remarkably consistent image is observed in both maps, derived from completely independent data and methods. Both approaches document a large modest root, exceeding 50 km depth in the central part of the Rif, in contrast with the rather small topographic elevations. This large crustal thickness, consistent with the available Bouguer anomaly data, favor models proposing that the high velocity slab imaged by seismic tomography beneath the Alboran Sea is still attached to the lithosphere beneath the Rif, hence pulling down the lithosphere and thickening the crust. The thickened area corresponds to a quiet seismic zone located between the western Morocco arcuate seismic zone, the deep seismicity area

  17. Imaging Lithospheric-scale Structure Beneath Northern Altiplano in Southern Peru and Northern Bolivia

    Science.gov (United States)

    Kumar, A.; Wagner, L. S.; Beck, S. L.; Zandt, G.; Long, M. D.

    2014-12-01

    The northern Altiplano plateau of southern Peru and northern Bolivia is one of the highest topographic features on the Earth, flanked by Western and Eastern Cordillera along its margin. It has strongly influenced the local and far field lithospheric deformation since the early Miocene (Masek et al., 1994). Previous studies have emphasized the importance of both the crust and upper mantle in the evolution of Altiplano plateau (McQuarrie et al., 2005). Early tomographic and receiver function studies, south of 16° S, show significant variations in the crust and upper mantle properties in both perpendicular and along strike direction of the Altiplano plateau (Dorbath et. al., 1993; Myers et al., 1998; Beck and Zandt, 2002). In order to investigate the nature of subsurface lithospheric structure below the northern Altiplano, between 15-18° S, we have determined three-dimensional seismic tomography models for Vp and Vs using P and S-wave travel time data from two recently deployed local seismic networks of CAUGHT and PULSE. We also used data from 8 stations from the PERUSE network (PERU Subduction Experiment). Our preliminary tomographic models show a complex variation in the upper mantle velocity structure with depth, northwest and southeast of lake Titicaca. We see the following trend, at ~85 km depth, northwest of lake Titicaca: low Vp and Vs beneath the Western Cordillera, high Vs beneath the Altiplano and low Vp and Vs beneath the Eastern Cordillera. This low velocity anomaly, beneath Eastern Cordillera, seems to coincide with Kimsachata, a Holocene volcano in southern Peru. At depth greater than ~85 km: we find high velocity anomaly beneath the Western Cordillera and low Vs beneath the Altiplano. This high velocity anomaly, beneath Western Cordillera, coincides with the well-located Wadati-Benioff zone seismicity and perhaps represents the subducting Nazca slab. On the southeast of lake Titicaca, in northern Bolivia, we see a consistently high velocity anomaly

  18. Seismic evidence for slab graveyards atop the Core Mantle Boundary beneath the Indian Ocean Geoid Low

    Science.gov (United States)

    Padma Rao, B.; Ravi Kumar, M.

    2014-11-01

    The Indian Ocean Geoid Low (IOGL) that spans a vast areal extent south of the Indian subcontinent is a spectacular feature on the Earth, whose origin still remains ambiguous. In this study, we investigate the seismic character of the lower mantle below this geoid low utilizing the travel time and amplitude residuals of high quality S and ScS phases from 207 earthquakes recorded at 276 stations in the epicentral distance range of 36°-90°. For comparison, we also perform a similar exercise for a region of geoid high in the vicinity. Results reveal large variations in the ScS travel times indicating that the lowermost mantle beneath the IOGL region is heterogeneous. The ScS-S differential travel times are ∼3 s slower than those predicted by the IASP91 model, primarily due to velocity increase in the lowermost mantle beneath the IOGL region and ∼2 s higher than the IASP91 beneath the geoid high region, due to velocity decrease in the lowermost mantle. The largest negative residuals from manual method (-7.72 s) are concentrated below the IOGL. Iterative matching of differential travel time residuals reveals that the maximum positive and negative residuals can be explained in terms of a reduction in shear velocity of 0.9% and an increase of 1.6% respectively in a ∼1000 km thick layer above the Core Mantle Boundary. Further, the ScS/S amplitude residuals beneath the IOGL are positive, implying high impedance contrast at the Core Mantle Boundary, owing to the presence of high velocity material. We attribute these high velocities to the presence of dehydrated high density slab graveyards atop the Core Mantle Boundary beneath the Indian Ocean. Release of water at the mid-to-upper mantle depths due to the dehydration of subducted slabs causing a reduction in density and velocity of the ambient mantle, could be responsible for the geoid low.

  19. Lithospheric structure beneath the High Lava Plains, Oregon, imaged by scattered teleseismic waves

    Science.gov (United States)

    Chen, Chin-Wu; James, David E.; Fouch, Matthew J.; Wagner, Lara S.

    2013-11-01

    We compute high-resolution seismic images from scattered wavefield to detect discontinuities beneath the High Lava Plains (HLP), using data recorded at a dense broadband array. Our images of the HLP and surrounding regions reveal (1) a prominent Moho discontinuity with varying depth, with thinnest crust of 35 km beneath the volcanic track, and thickened crust of ˜45 km beneath the Owyhee Plateau (OP); (2) distinct intracrustal velocity reversals beneath regions of pre-2.0 Ma volcanism and within the OP; and (3) intermittent negative velocity discontinuities in the uppermost mantle beneath regions of Holocene volcanism and volcanic centers near Steens Mountain and Newberry volcano. These features exhibit remarkable similarity with those seen in the surface wave tomography and Ps receiver functions. We fail to find evidence for a ubiquitous regional lithosphere-asthenosphere boundary (LAB). In concert with petrological constraints on the equilibration depths of primitive basaltic melts, our results suggest that the present-day HLP mantle lithosphere is thin or absent, perhaps a consequence of episodes of extensive mantle inflow, lithospheric extension, and possibly melting induced by rapid slab rollback and trench retreat. It remains possible, however, that strong E-W seismic anisotropy reported across this region may reduce the effective S-wave velocity contrast to render the LAB less detectable. In contrast, the Owyhee Plateau exhibits a clear LAB, consistent with it being a block of older preexisting lithosphere. Our images demonstrate the complexity of mantle dynamics in the Cascadian back-arc and the close casual link between subduction-related processes and the origin of HLP volcanism.

  20. The Impact of the Subduction Modeling Beneath Calabria on Seismic Hazard

    Science.gov (United States)

    Morasca, P.; Johnson, W. J.; Del Giudice, T.; Poggi, P.; Traverso, C.; Parker, E. J.

    2014-12-01

    The aim of this work is to better understand the influence of subduction beneath Calabria on seismic hazard, as very little is known about present-day kinematics and the seismogenic potential of the slab interface in the Calabrian Arc region. This evaluation is significant because, depending on stress conditions, subduction zones can vary from being fully coupled to almost entirely decoupled with important consequences in the seismic hazard assessment. Although the debate is still open about the current kinematics of the plates and microplates lying in the region and the degree of coupling of Ionian lithosphere beneath Calabria, GPS data suggest that this subduction is locked in its interface sector. Also the lack of instrumentally recorded thrust earthquakes suggests this zone is locked. The current seismotectonic model developed for the Italian National territory is simplified in this area and does not reflect the possibility of locked subduction beneath the Calabria that could produce infrequent, but very large earthquakes associated with the subduction interface. Because of this we have conducted an independent seismic source analysis to take into account the influence of subduction as part of a regional seismic hazard analysis. Our final model includes two separate provinces for the subduction beneath the Calabria: inslab and interface. From a geometrical point of view the interface province is modeled with a depth between 20-50 km and a dip of 20°, while the inslab one dips 70° between 50 -100 km. Following recent interpretations we take into account that the interface subduction is possibly locked and, in such a case, large events could occur as characteristic earthquakes. The results of the PSHA analysis show that the subduction beneath the Calabrian region has an influence in the total hazard for this region, especially for long return periods. Regional seismotectonic models for this region should account for subduction.

  1. 针对Ghost还原的木马隐蔽驻留技术研究%Research on Trojan Horse Hiding and Residence Technology According to Ghost Restoration

    Institute of Scientific and Technical Information of China (English)

    郑成; 王轶骏; 薛质

    2012-01-01

    Ghost reduction system is widely used in the computer system restoration, this technology is easy to use while contains certain safety hidden trouble. This paper first describes Ghost image file format, and tells of its analytical process and principles. And on this basis, this paper draws out the Trojan hiding and residence technology of the Ghost image reduction system, and analyzes the realization of command line tool which can penetrate the Ghost image file. This tool reads and analyzes Ghost image file, and then writes in the back door to their files, thus to realize the Trojan horse hiding and residence. This paper finally puts forth how to prevent and detect the hiding and residing Trojan by this method, and thus to ensure the integrity and safety of restored system.%Ghost还原系统已经被广泛应用于计算机的系统还原,该技术在使用方便的同时,也存在着安全隐患。文中首先介绍了Ghost映像文件的格式,并阐述其解析的过程和原理。然后在此基础上引出针对Ghost还原系统映像的木马隐蔽驻留技术,并剖析了所实现的Ghost映像文件穿越的命令行工具。该工具读取解析Ghost映像文件,然后往其中写入后门文件来实现木马的隐蔽驻留。最后提出了如何预防和检测利用该方法隐蔽驻留的木马,确保系统还原后的完整和安全。

  2. A VoIP Privacy Mechanism and its Application in VoIP Peering for Voice Service Provider Topology and Identity Hiding

    CERN Document Server

    Shen, Charles

    2008-01-01

    Voice Service Providers (VSPs) participating in VoIP peering frequently want to withhold their identity and related privacy-sensitive information from other parties during the VoIP communication. A number of existing documents on VoIP privacy exist, but most of them focus on end user privacy. By summarizing and extending existing work, we present a unified privacy mechanism for both VoIP users and service providers. We also show a case study on how VSPs can use this mechanism for identity and topology hiding in VoIP peering.

  3. Neogene kinematic history of Nazca-Antarctic-Phoenix slab windows beneath Patagonia and the Antarctic Peninsula

    Science.gov (United States)

    Breitsprecher, Katrin; Thorkelson, Derek J.

    2009-01-01

    The Patagonian slab window is a subsurface tectonic feature resulting from subduction of the Nazca-Antarctic spreading-ridge system (Chile Rise) beneath southern South America. The geometry of the slab window had not been rigorously defined, in part because of the complex nature of the history of ridge subduction in the southeast Pacific region, which includes four interrelated spreading-ridge systems since 20 Ma: first, the Nazca-Phoenix ridge beneath South America, then simultaneous subduction of the Nazca-Antarctic and the northern Phoenix-Antarctic spreading-ridge systems beneath South America, and the southern Phoenix-Antarctic spreading-ridge system beneath Antarctica. Spreading-ridge paleo-geographies and rotation poles for all relevant plate pairs (Nazca, Phoenix, Antarctic, South America) are available from 20 Ma onward, and form the mathematical basis of our kinematic reconstruction of the geometry of the Patagonia and Antarctic slab windows through Neogene time. At approximately 18 Ma, the Nazca-Phoenix-Antarctic oceanic (ridge-ridge-ridge) triple junction enters the South American trench; we recognize this condition as an unstable quadruple junction. Heat flow at this junction and for some distance beneath the forearc would be considerably higher than is generally recognized in cases of ridge subduction. From 16 Ma onward, the geometry of the Patagonia slab window developed from the subduction of the trailing arms of the former oceanic triple junction. The majority of the slab window's areal extent and geometry is controlled by the highly oblique (near-parallel) subduction angle of the Nazca-Antarctic ridge system, and by the high contrast in relative convergence rates between these two plates relative to South America. The very slow convergence rate of the Antarctic slab is manifested by the shallow levels achieved by the slab edge (< 45 km); thus no point on the Antarctic slab is sufficiently deep to generate "normal" mantle-derived arc-type magmas

  4. Hackers in Hiding:

    DEFF Research Database (Denmark)

    Hansen, Ejvind

    2016-01-01

    . In this paper, I will analyse the conflict between the hacker movement and the field of corporate interests. I argue that the introduction of graphical user interfaces and the maintaining of copyright interests are the contingent background of the ongoing conflict. By bracketing the analyses of hidden...

  5. The aliens are hiding

    Science.gov (United States)

    2015-06-01

    In reply to the physicsworld.com news story “Trail goes cold on alien hotspots, for now” (28 April, http://ow.ly/MeOpZ; see also p5), which described the results of a survey that looked for unexplained pockets of infrared radiation that could have been produced by advanced alien civilizations.

  6. Jekyll and Hide

    Science.gov (United States)

    Proft, Juliane; Weiss, Norbert

    2012-01-01

    Neurodegenerative diseases are a burden of our century. Although significant efforts were made to find a cure or relief to this scourge, their pathophysiology remains vague and the cellular function of the key involved proteins is still unclear. However, in the case of amyloid β (Aβ), a key protein concerned in Alzheimer disease, we are now a step closer in the unscrambling of its cellular functions. Interestingly, whereas the exact role of Aβ in the pathophysiology of Alzheimer disease is still unresolved, a recent study revealed a neuroprotective function of Aβ in multiple sclerosis with possibly promising therapeutic benefits. PMID:23181153

  7. Hide and seek

    DEFF Research Database (Denmark)

    Radel, Dietrich; Sand, Andreas; Steel, Mike

    2013-01-01

    Finding optimal evolutionary trees from sequence data is typically an intractable problem, and there is usually no way of knowing how close to optimal the best tree from some search truly is. The problem would seem to be particularly acute when we have many taxa and when that data has high levels...

  8. Melt transport rates in heterogeneous mantle beneath mid-ocean ridges

    CERN Document Server

    Weatherley, Samuel M

    2015-01-01

    Recent insights to melt migration beneath ridges suggest that channelized flow is a consequence of melting of a heterogeneous mantle, and that spreading rate modulates the dynamics of the localized flow. A corollary of this finding is that both mantle het- erogeneity and spreading rate have implications for the speed and time scale of melt migration. Here, we investigate these implications using numerical models of magma flow in heterogeneous mantle beneath spreading plates. The models predict that a broad distribution of magma flow speeds is characteristic of the sub-ridge mantle. Within the melting region, magmatic flow is fastest in regions of average fusibility; surprisingly, magmas from sources of above-average fusibility travel to the ridge in a longer time. Spreading rate has comparatively simple consequences, mainly resulting in faster segregation speeds at higher spreading rates. The computed time scales are short enough to preserve deep origin 230Th disequilibria and, under favourable parameter regi...

  9. Crustal magma pathway beneath Aso caldera inferred from three-dimensional electrical resistivity structure

    Science.gov (United States)

    Hata, Maki; Takakura, Shinichi; Matsushima, Nobuo; Hashimoto, Takeshi; Utsugi, Mitsuru

    2016-10-01

    At Naka-dake cone, Aso caldera, Japan, volcanic activity is raised cyclically, an example of which was a phreatomagmatic eruption in September 2015. Using a three-dimensional model of electrical resistivity, we identify a magma pathway from a series of northward dipping conductive anomalies in the upper crust beneath the caldera. Our resistivity model was created from magnetotelluric measurements conducted in November-December 2015; thus, it provides the latest information about magma reservoir geometry beneath the caldera. The center of the conductive anomalies shifts from the north of Naka-dake at depths >10 km toward Naka-dake, along with a decrease in anomaly depths. The melt fraction is estimated at 13-15% at 2 km depth. Moreover, these anomalies are spatially correlated with the locations of earthquake clusters, which are distributed within resistive blocks on the conductive anomalies in the northwest of Naka-dake but distributed at the resistive sides of resistivity boundaries in the northeast.

  10. Electromagnetic evidence for volatile-rich upwelling beneath the society hotspot, French Polynesia

    Science.gov (United States)

    Tada, Noriko; Tarits, Pascal; Baba, Kiyoshi; Utada, Hisashi; Kasaya, Takafumi; Suetsugu, Daisuke

    2016-12-01

    We have conducted a seafloor magnetotelluric survey that images, for the first time, three-dimensional electrical conductivity structure in the upper mantle beneath the Society hotspot. A striking feature in our model is a high-conductivity anomaly a few hundred kilometers in diameter, which is continuous from the lowest part of the upper mantle to a depth of approximately 50 km below sea level. Using theoretical and experimental results from mineral physics, we interpret the high-conductivity anomaly as evidence of the melt fraction up to 2.2 vol.%, which is robust regardless of assumed temperature, and the existence of carbonated silicate melt beneath the hotspot. Our results suggest that the Society hotspot is a pathway for ascending volatiles from the deeper part of the upper mantle to the surface.

  11. The crustal structure beneath Mauritius from teleseismic P-receiver functions - oceanic or continental?

    Science.gov (United States)

    Singh, Manvendra; Kaviani, Ayoub; Rümpker, Georg

    2016-09-01

    It has recently been suggested that the volcanic island of Mauritius may be underlain by a remnant of continental origin termed "Mauritia". To constrain the crustal thickness beneath Mauritius, we analyzed data from 11 land stations, 10 of which were deployed recently by the RHUM-RUM project. From the recordings, we obtained 382 P-receiver functions (RFs). By applying the H-κ stacking technique, we derive crustal thicknesses of approximately 10-15 km. We observe a considerable variation in the Vp/Vs-ratio caused by a lack of clear multiples. Using forward modeling of RFs, we show that the lack of clear multiples can be explained by a transitional Moho, where the velocity increases gradually. The modeling further indicates that the thickness of this gradient zone is estimated to be approximately 10 km. We argue that our findings suggest oceanic crust thickened by crustal underplating due the mantle plume currently located beneath the La Réunion.

  12. Using Sealed Wells to Measure Water Levels Beneath Streams and Floodplains.

    Science.gov (United States)

    Noorduijn, Saskia L; Cook, Peter G; Wood, Cameron; White, Nick

    2015-01-01

    The design of wells beneath streams and floodplains has often employed with tall standpipes to prevent incursion of surface water into the well during flood events. Here, an approach has been presented to minimise the infrastructure demands in these environments by sealing the well top (e.g., prevent water entering the well) and monitor the total pressure in the water column using an absolute (non-vented) pressure transducer. The sealed well design was tested using a laboratory experiment where the total pressure responses were monitored in both an unsealed and sealed well, while the water level was varied. It is observed that, whether the well is sealed or not, the total pressure at a given depth in the aquifer will be equal to that within the well. This indicates that the sealed well design is a viable alternative to tall standpipes and also facilitates installation of wells beneath streams and floodplains.

  13. Shear-wave velocity structure of the crust and upper mantle beneath the Kola Peninsula

    Science.gov (United States)

    Dricker, I. G.; Roecker, S. W.; Kosarev, G. L.; Vinnik, L. P.

    We determined the shear-wave velocity structure of the crust and upper mantle beneath the central part of the Kola peninsula from the analysis of P-wave receiver functions and mantle P-SV converted phases recorded at stations Apatity (APA) and Lovozero (LVZ). The times of P-SV converted phases from the 410 and 660 km discontinuities are close to those predicted by the IASP91 model. Phase conversions at the crust-mantle boundary beneath the Baltic shield northeast of LVZ and southwest of APA are consistent with a sharp transition from crust to mantle at a depth of 40 km, while conversions from the intervening Khibina plutonic region are consistent with a gradual transition between depths of 20 and 40 km. We infer that short (∼50 km) wavelength lateral variations in the crust-mantle transition persist in this region, despite the inactivity of the Kola peninsula since Devonian times.

  14. Mid-lithosphere discontinuities beneath the western and central North China Craton

    Science.gov (United States)

    Sun, Weijia; Kennett, B. L. N.

    2017-02-01

    By analyzing P reflectivity extracted from stacked autocorrelograms for teleseismic events on a dense seismic profile, we obtain a detailed image of the mid-lithosphere discontinuity (MLD) beneath western and central North China Craton (NCC). This seismic daylight imaging exploits a broad high-frequency band (0.5-4 Hz) to reveal the fine-scale component of multi-scale lithospheric heterogeneity. The depth of the MLD beneath the western and central parts of the NCC ranges 80-120 km, with a good match to the transition to negative S velocity gradient with depth from Rayleigh wave tomography. The MLD inferred from seismic daylight imaging also has good correspondence with the transition from conductive to convective regimes estimated from heat flow data indicating likely thermal control within the seismological lithosphere.

  15. Tomography reveals buoyant asthenosphere accumulating beneath the Juan de Fuca plate

    Science.gov (United States)

    Hawley, William B.; Allen, Richard M.; Richards, Mark A.

    2016-09-01

    The boundary between Earth’s strong lithospheric plates and the underlying mantle asthenosphere corresponds to an abrupt seismic velocity decrease and electrical conductivity increase with depth, perhaps indicating a thin, weak layer that may strongly influence plate motion dynamics. The behavior of such a layer at subduction zones remains unexplored. We present a tomographic model, derived from on- and offshore seismic experiments, that reveals a strong low-velocity feature beneath the subducting Juan de Fuca slab along the entire Cascadia subduction zone. Through simple geodynamic arguments, we propose that this low-velocity feature is the accumulation of material from a thin, weak, buoyant layer present beneath the entire oceanic lithosphere. The presence of this feature could have major implications for our understanding of the asthenosphere and subduction zone dynamics.

  16. Lithosphere-Asthenosphere Boundary Beneath Regions of Recent Volcanism in the Basin and Range Province and Mojave Desert

    Science.gov (United States)

    Forsyth, D. W.; Rau, C. J.; Plank, T.; Gazel, E.; Bendersky, C.

    2010-12-01

    Melt in the asthenosphere may contribute strongly to the development of the lithosphere-asthenosphere boundary (LAB) in some settings. We have compiled a set of vertical shear-velocity profiles beneath centers of recent (<1.0 Ma) volcanic activity in the Basin and Range province based on Rayleigh wave tomography. The classic pattern of a high-velocity lid overlying a low-velocity zone (LVZ) is clear beneath many of the centers. Cima, for example, has a high velocity lid extending to a depth of about 60 km. Beneath Dish Hill and Amboy in the southern Mojave, the lithospheric lid extends to a depth of ~ 90 km. Minimum velocities in the LVZs beneath the higher velocity lids typically are 4.00-4.05 km/s, similar to that beneath the East Pacific Rise and too low to be caused by temperature alone without unreasonably high attenuation. Beneath other centers, like Big Pine, Lathrop Wells and Tahoe, there is no resolvable lid. The lid is either missing or too thin to resolve, but the absence of the lid/LVZ pattern seems to be due to a combination of lower velocities immediately beneath the Moho and higher velocities in the LVZ. Petrological indicators of temperature and depth of melting from basalt composition are in general agreement with the seismological observations, with the depth of last equilibration typically occurring near the top of the LVZ. Beneath Big Pine, for example, the equilibration temperatures are unusually low and the equilibration depth is 40 to 50 km, just below the Moho, in agreement with the lack of a distinct lid. Beneath Cima, equilibration depths are 60-70 km. Beneath Coso, equilibration depths are only slightly deeper than Big Pine, but the temperatures are higher, in agreement with the more pronounced LVZ and the presence of a thin lid. Beneath the Tabernacle Hill/Black Rock volcanic field in west-central Utah, there is a well-developed lid/LVZ structure, but the "high" velocity lid is only ~ 4.10 km/s while the underlying LVZ reaches as low as

  17. File Hide Method Based on Drive Stack Unit%基于驱动堆栈单元的文件隐藏方法

    Institute of Scientific and Technical Information of China (English)

    何耀彬; 李祥和; 孙岩

    2011-01-01

    为能在操作系统的驱动级实现新的文件隐藏点,对传统的文件系统过滤驱动原理和驱动数据堆栈单元结构进行分析.通过修改驱动堆栈单元的结构和完成例程,配合修改I/O请求包的传递方法,实现2种驱动级文件隐藏的方法.使用该2种方法的文件可以在系统中实现深度隐藏,使得操作系统无法查询,也不能通过正常途径访问.%In order to get new file hidden points in drive-level of system, the principle of File System Filter Driver(FSFD) and the structure of driver stack location are analyzed. Through making some changes in driver stack location's structure and CompletionRoutine, besides modifying the I/O Requst Packet(IRP) delivery method, two methods to hide files are implemented. Hidden files using these methods achieve depth hide. They can not be queried by system or be accessed through normal channels.

  18. Compositions of Upper Mantle Fluids Beneath Eastern China:Implications for Mantle Evolution

    Institute of Scientific and Technical Information of China (English)

    ZHANG Mingjie; WANG Xianbin; LIU Gang; ZHANG Tongwei; BO Wenrui

    2004-01-01

    The composition of gases trapped in olivine, orthopyroxene and clinopyroxene in lherzolite xenoliths collected from different locations in eastern China has been measured by the vacuum stepped-heating mass spectrometry.These xenoliths are hosted in alkali basalts and considered as residues of partial melting of the upper mantle, and may contain evidence of mantle evolution. The results show that various kinds of fluid inclusions in lherzolite xenoliths have been released at distinct times, which could be related to different stages of mantle evolution. In general, primitive fluids of the upper mantle (PFUM) beneath eastern China are dominated by H2, CO2 and CO, and are characterized by high contents of H2 and reduced gases. The compositions of PFUM are highly variable and related to tectonic settings. CO, CO2 and H2 are the main components of the PFUM beneath cratons; the PFUM in the mantle enriched in potassic metasomatism in the northern part of northeastern China has a high content of H2, while CO2 and SO2 are the dominant components of the PFUM in the Su-Lu-Wan (Jiangsu-Shandong-Anhui) region, where recycled crustal fluids were mixed with deeper mantle components. There are several fluids with distinct compositions beneath eastern China, such as primitive fluids of upper mantle (CO, CO2 and H2), partial melting fluids (CO2 and CO) and metasomatic fluids mixed with recycled crustal fluids (CO2, N2, 8O2 and CH4) etc. Fluids of the upper mantle beneath the North China craton are different from that of the South China craton in total gases and chemical compositions: the contents of the reduced gases of the PFUM in the NCC are higher than those in the SCC.

  19. Melt zones beneath five volcanic complexes in California: an assessment of shallow magma occurrences

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, N.E.; Flexser, S.

    1984-12-01

    Recent geological and geophysical data for five magma-hydrothermal systems were studied for the purpose of developing estimates for the depth, volume and location of magma beneath each area. The areas studied were: (1) Salton Trough, (2) The Geysers-Clear Lake, (3) Long Valley caldera, (4) Coso volcanic field, and (5) Medicine Lake volcano, all located in California and all selected on the basis of recent volcanic activity and published indications of crustal melt zones. 23 figs.

  20. Are assemblages of the fireworm Hermodice carunculata enhanced in sediments beneath offshore fish cages?

    Institute of Scientific and Technical Information of China (English)

    Rodrigo Riera; Oscar Prez; Myriam Rodrguez; Eva Ramos; scar Monterroso

    2014-01-01

    Abundances of the fireworm Hermodice carunculata were counted through a monitoring assessment study of fish cages in Barranco Hondo (NE Tenerife). Seven campaigns were conducted from November 2007 to June 2010 and temporal variations were found, as well as differences among sampling stations. The poly-chaete H. carunculata obtained its highest abundance in sediments beneath fish cages throughout the study period. Thus, the assemblages of this omnivorous species were favoured by the presence of fish cages.