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Sample records for density irregularities diagnosed

  1. Inferring the Coronal Density Irregularity from EUV Spectra

    CERN Document Server

    Hahn, Michael

    2016-01-01

    Understanding the density structure of the solar corona is important for modeling both coronal heating and the solar wind. Direct measurements are difficult because of line-of-sight integration and possible unresolved structures. We present a new method for quantifying such structure using density-sensitive EUV line intensities to derive a density irregularity parameter, a relative measure of the amount of structure along the line of sight. We also present a simple model to relate the inferred irregularities to physical quantities, such as the filling factor and density contrast. For quiet Sun regions and interplume regions of coronal holes, we find a density contrast of at least a factor of three to ten and corresponding filling factors of about 10-20%. Our results are in rough agreement with other estimates of the density structures in these regions. The irregularity diagnostic provides a useful relative measure of unresolved structure in various regions of the corona.

  2. Determining Ionospheric Irregularity Spectral Density Function from Japan GEONET

    Science.gov (United States)

    Lay, E. H.; Light, M. E.; Parker, P. A.; Carrano, C. S.; Haaser, R. A.

    2015-12-01

    Japan's GEONET GPS network is the densest GPS monitoring network in the world, with 1200+ receivers over the area of Japan. Measuring and calibrating the integrated total electron content (TEC) from each station has been done in many cases to provide detailed maps of ionospheric disturbances over Japan. We use TEC measurements from Japan's GEONET array to determine an empirically derived description of the 2-dimensional scale sizes of spatial irregularities above Japan. The contributions from various scale sizes will be included in a statistical description for the irregularity spectral density (ISD) function. We will compare the statistics of the spatial irregularities between calm and moderately scintillated conditions.

  3. Accurate bulk density determination of irregularly shaped translucent and opaque aerogels

    Science.gov (United States)

    Petkov, M. P.; Jones, S. M.

    2016-05-01

    We present a volumetric method for accurate determination of bulk density of aerogels, calculated from extrapolated weight of the dry pure solid and volume estimates based on the Archimedes' principle of volume displacement, using packed 100 μm-sized monodispersed glass spheres as a "quasi-fluid" media. Hard particle packing theory is invoked to demonstrate the reproducibility of the apparent density of the quasi-fluid. Accuracy rivaling that of the refractive index method is demonstrated for both translucent and opaque aerogels with different absorptive properties, as well as for aerogels with regular and irregular shapes.

  4. Causes of Irregular Energy Density in $f(R,T)$ Gravity

    CERN Document Server

    Yousaf, Z; Bhatti, M Zaeem ul Haq

    2016-01-01

    We investigate irregularity factors for a self-gravitating spherical star evolving in the presence of imperfect fluid. We explore the gravitational field equations and the dynamical equations with the systematic construction in $f(R,T)$ gravity, where $T$ is the trace of the energy-momentum tensor. Furthermore, we analyze two well-known differential equations (which occupy principal importance in the exploration of causes of energy density inhomogeneities) with the help of the Weyl tensor and the conservation laws. The irregularity factors for a spherical star are examined for particular cases of dust, isotropic and anisotropic fluids in dissipative and non-dissipative regimes in the framework of $f(R,T)$ gravity. It is found that as the complexity in the matter with the anisotropic stresses increases, the inhomogeneity factor has more correspondences to one of the structure scalars.

  5. Optimized Irregular Low-Density Parity-Check Codes for Multicarrier Modulations over Frequency-Selective Channels

    Directory of Open Access Journals (Sweden)

    Gelle Guillaume

    2004-01-01

    Full Text Available This paper deals with optimized channel coding for OFDM transmissions (COFDM over frequency-selective channels using irregular low-density parity-check (LDPC codes. Firstly, we introduce a new characterization of the LDPC code irregularity called “irregularity profile.” Then, using this parameterization, we derive a new criterion based on the minimization of the transmission bit error probability to design an irregular LDPC code suited to the frequency selectivity of the channel. The optimization of this criterion is done using the Gaussian approximation technique. Simulations illustrate the good performance of our approach for different transmission channels.

  6. Sub-Auroral Ion Drifts as a Source of Mid-Latitude Plasma Density Irregularities

    Science.gov (United States)

    Sotnikov, V.; Kim, T.; Mishin, E.; Paraschiv, I.; Rose, D.

    Ionospheric irregularities cause scintillations of electromagnetic signals that can severely affect navigation and transionospheric communication, in particular during space storms. At midlatitudes, such space weather events are caused mainly by subauroral electric field structures (SAID/SAPS) [1, 2]. SAID/SAPS -related shear flows and plasma density troughs point to interchange and Kelvin-Helmholtz type instabilities as a possible source of plasma irregularities. A model of nonlinear development of these instabilities based on the two-fluid hydrodynamic description with inclusion of finite Larmor radius effects will be presented. A numerical code in C language to solve the derived nonlinear equations for analysis of interchange and flow velocity shear instabilities in the ionosphere was developed. This code was used to analyze competition between interchange and Kelvin Helmholtz instabilities in the equatorial region [3]. The high-resolution simulations with continuous density and velocity profiles will be driven by the ambient conditions corresponding to the in situ Defence Military Satellite Program (DMSP) satellite low-resolution data [2] during UHF/GPS L-band subauroral scintillation events. [1] Mishin, E. (2013), Interaction of substorm injections with the subauroral geospace: 1. Multispacecraft observations of SAID, J. Geophys. Res. Space Phys., 118, 5782-5796, doi:10.1002/jgra.50548. [2] Mishin, E., and N. Blaunstein (2008), Irregularities within subauroral polarization stream-related troughs and GPS radio interference at midlatitudes. In: T. Fuller-Rowell et al. (eds), AGU Geophysical Monograph 181, MidLatitude Ionospheric Dynamics and Disturbances, pp. 291-295, doi:10.1029/181GM26, Washington, DC, USA. [3] V. Sotnikov, T. Kim, E. Mishin, T. Genoni, D. Rose, I. Paraschiv, Development of a Flow Velocity Shear Instability in the Presence of Finite Larmor Radius Effects, AGU Fall Meeting, San Francisco, 15 - 19 December, 2014.

  7. Detection of F-region electron density irregularities using incoherent-scatter radar

    Science.gov (United States)

    Gudivada, Krishna Prasad

    Incoherent-scatter radar data from Poker Flat, Alaska has been used to determine size distributions of electron density structures in the evening time sector of the auroral zone. At high latitudes ionospheric plasma typically moves east-west with speeds of several hundred meters per second. Density irregularities that rapidly move through the radar beam are therefore observed as time-varying power fluctuations. The new phased array radar used for this study has been operated with several antenna directions with successive pulses transmitted in each direction. It is therefore possible to observe plasma Doppler velocities in multiple directions and determine the vector direction of the plasma motion. This near-simultaneous observation of the plasma velocity in conjunction with the electron density height profile data enable a new technique to determine the scale sizes of electron density fluctuations that move horizontally through the radar beam. The study focuses on the collision-less F-region ionosphere where the plasma drift is approximately constant with altitude. The experimental technique limits the range of scale sizes that may be studied to relatively large-scale sizes (i.e. greater than few tens of km). Results show that during magnetically disturbed conditions (Kp ≥ 4) when westward plasma velocities are relatively high (500-1000 m/s) the scale sizes of irregularities (often called plasma blobs) are in the range of 100-300 km and predominantly originate from the polar cap and are transported over long distances (˜1000 km) due to the long chemical recombination times (30-90 minutes). Some irregularities are caused by local auroral particle precipitation and have been identified with associated electron temperature enhancements. For cases of low magnetic activity (Kp ≤ 1), when the radar is located in a region of low plasma velocities (100-500 m/s) well south of the auroral oval (essentially a mid-latitude type ionosphere), the density distribution is

  8. Simulation of EMIC growth and propagation within the plasmaspheric plume density irregularities

    Science.gov (United States)

    de Soria-Santacruz Pich, M.; Spasojevic, M.

    2012-12-01

    In situ data from the Magnetospheric Plasma Analyzer (MPA) instruments onboard the LANL spacecraft are used to study the growth and propagation of electromagnetic ion cyclotron (EMIC) waves in the presence of cold plasma irregularities in the plasmaspheric plume. The data corresponds to the 9 June 2001 event, a period of moderate geomagnetic activity with highly irregular density structure within the plume as measured by the MPA instrument at geosynchoronus orbit. Theory and observations suggest that EMIC waves are responsible for energetic proton precipitation, which is stronger during geomagnetically disturbed intervals. These waves propagate below the proton gyrofrequency, and they appear in three frequency bands due to the presence of heavy ions, which strongly modify wave propagation characteristics. These waves are generated by ion cyclotron instability of ring current ions, whose temperature anisotropy provides the free energy required for wave growth. Growth maximizes for field-aligned propagation near the equatorial plane where the magnetic field gradient is small. Although the wave's group velocity typically stays aligned with the geomagnetic field direction, wave-normal vectors tend to become oblique due to the curvature and gradient of the field. On the other hand, radial density gradients have the capability of guiding the waves and competing against the magnetic field effect thus favoring wave growth conditions. In addition, enhanced cold plasma density reduces the proton resonant energy where higher fluxes are available for resonance, and hence explaining why wave growth is favored at higher L-shell regions where the ratio of plasma to cyclotron frequency is larger. The Stanford VLF 3D Raytracer is used together with path-integrated linear growth calculations to study the amplification and propagation characteristics of EMIC waves within the plasmaspheric plume formed during the 9 June 2001 event. Cold multi-ion plasma is assumed for raytracing

  9. Energetic efficiency, menstrual irregularity, and bone mineral density in elite professional female ballet dancers.

    Science.gov (United States)

    Doyle-Lucas, Ashley F; Akers, Jeremy D; Davy, Brenda M

    2010-01-01

    Sports that emphasize low body weight for optimal performance, such as ballet, are associated with an increased prevalence of the female athlete triad (FT). Previous research in this area that involves dancers has been limited; the majority of studies have been performed on adolescents training in classical ballet, and not professional adult dancers. The purpose of this study is to compare the physical and behavioral characteristics of female elite ballet dancers to sedentary, recreationally active non-dancing controls, with regard to characteristics of the FT and energetic efficiency. Women aged 18 to 35 years were recruited as participants. The dancers (N = 15) and non-dancing controls (N = 15) were pair-matched via age (dancers: 24.3 ± 1.3 years; controls: 23.7 ± 0.9 years), body mass index (dancers: 18.9 ± 0.2; controls: 19.4 ± 0.2 kg/m 2 ), and fat-free mass (dancers: 44.3 ± 0.8; controls: 44.1 ± 0.9 kg). Assessments included habitual dietary intake using 4-day food records, self-reported physical activity, psychometric measures of eating behaviors, health and menstrual history, body composition and bone density (dual energy x-ray absorptiometry), and resting metabolic rate (RMR) assessed by indirect calorimetry. Characteristics of the FT, specifically menstrual irregularities (6 of 15 dancers reported irregular or no menses; 1 of 15 controls reported irregular menses) and low energy availability, were more prevalent in dancers than in pair-matched controls. Despite having a similar fat-free mass (FFM), dancers had a significantly lower absolute RMR (dancers: 1367 ± 27; controls: 1454 ± 34 kcal/d; p ≤ 0.05) and significantly lower RMR relative to FFM (dancers: 30.9 ± 0.6; controls: 33.1 ± 0.8 kcal/kg fat-free mass/d; p ≤ 0.05). Energy intake between dancers (1577 ± 89 kcal/d) and pair-matched controls (2075 ± 163 kcal/d) also differed significantly (p ≤ 0.01). Six of the 15 dancers met the criteria for the FT (including low bone mineral

  10. DEMETER Observations of Highly Structured Plasma Density and Associated ELF Electric Field and Magnetic Field Irregularities at Middle and Low Latitudes

    Science.gov (United States)

    Pfaff, R.; Liebrecht, C.; Berthelier, J.-J.; Parrot, M.; Lebreton, J.-P.

    2008-01-01

    The DEMETER spacecraft frequently encounters structured plasma and electric field irregularities associated with equatorial spread-F. However, during severe geonagnetic storms, the spacecraft detects broader regions of density structures that extend to higher latitudes, in some instances to the sub-auroral regions. In addition to the electric field irregularities, ELF magnetic field irregularities are sometimes observed. for example, on the walls of the density structures, and appear related to finely-structured spatial currents and/or Alfven waves. The mid-latitude irregularities are compared with those of equatorial spread-F as well as wit11 intense irregularities associated with the trough region observed at sub-auroral latitudes.

  11. The relation between atomic gas and star formation rate densities in faint irregular galaxies

    CERN Document Server

    Roychowdhury, Sambit; Kaisin, Serafim S; Karachentsev, Igor D

    2014-01-01

    We use data for faint (M_B > -14.5) dwarf irregular galaxies drawn from the FIGGS survey to study the correlation between the atomic gas density (Sigma_gas,atomic) and star formation rate (Sigma_SFR) in the galaxies. The estimated gas phase metallicity of our sample galaxies is Z ~ 0.1 Z_sun. Understanding star formation in such molecule poor gas is of particular importance since it is likely to be of direct relevance to simulations of early galaxy formation. For about 20% (9/43) of our sample galaxies, we find that the HI distribution is significantly disturbed, with little correspondence between the optical and HI distributions. We exclude these galaxies from the comparison. We also exclude galaxies with very low star formation rates, for which stochastic effects make it difficult to estimate the true star formation rates. For the remaining galaxies we compute the Sigma_gas,atomic and Sigma_SFR averaged over the entire star forming disk of the galaxy. For these galaxies we find a nearly linear relation betw...

  12. Characteristics of field-aligned density depletion irregularities in the auroral ionosphere that duct Z- and X-mode waves

    Science.gov (United States)

    James, H. G.

    2006-09-01

    The small-scale and two-point nature of the Observations of Electric-field Distributions in the Ionospheric Plasma—A Unique Strategy C (OEDIPUS-C, OC) dual-payload propagation experiment in the auroral ionosphere in 1995 has permitted improved measurements of the parameters of magnetic field-aligned density irregularities. Comparatively strong and dispersed pulses were observed at frequencies f just above the electron plasma frequency fp when the electron gyrofrequency fc was less than fp. The waves are interpreted as quasielectrostatic Z-mode propagation with dispersion surfaces close to those of the Langmuir solutions in wave vector space, albeit at somewhat lower refractive indices of about 50. If mission length surveys of the Z-wave intensities are aligned with histories of fp at the payload and of the strength of X- and fast Z-mode ionospheric reflection echoes, a strong positive correlation is found at momentary relative depletions of the ambient density. These observations are taken as evidence of ducting in the field-aligned depletions. The spectra of these strong Z-mode transmissions are similar to those of slow Z ducted spectra observed at similar f, fp, and fc values in the OEDIPUS-A experiment in 1989. The magnitudes of the density depletions are found to lie in the range 7-21% and to have cross-field dimensions of a few kilometers. The present duct dimensions are of the same order as the previous findings from ionospheric X-mode electromagnetic echoes on OC, but the depletions are up to 10 times deeper. Measurements of ducting irregularities can lead to insights into their formation. This will be important for our understanding of the interfaces of the ionospheric or magnetospheric topologies where irregularity formation is an important link in the large-scale flow of energy.

  13. Comparison of the orientation of small-scale electron density irregularities and F region plasma flow direction

    Directory of Open Access Journals (Sweden)

    E. D. Tereshchenko

    Full Text Available Results are shown from an experimental campaign where satellite scintillation was observed at three sites at high latitudes and, simultaneously, the F region plasma flow was measured by the nearby EISCAT incoherent scatter radar. The anisotropy parameters of field-aligned irregularities are determined from amplitude scintillation using a method based on the variance of the relative logarithmic amplitude. The orientation of the anisotropy in a plane perpendicular to the geomagnetic field is compared with the direction of F region plasma flow. The results indicate that in most cases a good agreement between the two directions is obtained.

    Key words: Ionosphere (auroral ionosphere; ionospheric irregularities

  14. A long-term study on the deletion criterion of questionable electron density profiles caused by ionospheric irregularities - COSMIC radio occultation technique

    Science.gov (United States)

    Uma, G.; Brahmanandam, P. S.; Chu, Y. H.

    2016-06-01

    The crucial assumption made in the retrieval of radio-occultated atmospheric parameters is the spherical symmetry of the atmospheric refractive index, which implies that no horizontal gradient of the refractive index exists along the spherical shell. Nevertheless, the presence of density irregularities will lead to scintillation and multipath effects that often create highly fluctuating and random electron density profiles. In this study, it is proposed a reliable data quality control (QC) approach to remove questionable electron density profiles (due to the presence of ionospheric irregularities) retrieved using the COSMIC radio occultation (RO) technique based on two parameters, namely, the gradient and fluctuation of the topside density profile. Statistics of seven years density profiles (July 2006-May 2013) are presented by determining the aforementioned parameters for every density profile. The main advantage of this data QC is that it uses COSMIC RO electron density profiles retrieved from the slant total electron content (TEC) that is estimated from the excess phases of the GPS L1 and L2 frequencies only to delete the questionable profiles, instead of relying on any model and other observations. A systematic criterion has been developed based on the statistics to relinquish the so-called questionable density profiles. The computed gradients and fluctuations of the topside ionosphere electron density profiles have shown a few important features including, solar activity dependency and pronounced variations in between around +40° and -40° latitudes. After the removal of questionable profiles, both peak densities and heights of the ionosphere F layer are presented globally in different seasons of years during 2007 and 2012 that revealed several important features.

  15. Irregular Periods

    Science.gov (United States)

    ... blood become too low or too high. Some women have irregular periods because their bodies produce too much androgen, which is a hormone that causes increased muscle mass, facial hair, and deepening of the voice in males and ...

  16. Electric Field and Plasma Density Observations of Irregularities and Plasma Instabilities in the Low Latitude Ionosphere Gathered by the C/NOFS Satellite

    Science.gov (United States)

    Pfaff, Robert F.; Freudenreich, H.; Rowland, D.; Klenzing, J.; Liebrecht, C.

    2012-01-01

    The Vector Electric Field Investigation (VEFI) on the C/NOFS equatorial satellite provides a unique data set which includes detailed measurements of irregularities associated with the equatorial ionosphere and in particular with spread-F depletions. We present vector AC electric field observations gathered on C/NOFS that address a variety of key questions regarding how plasma irregularities, from meter to kilometer scales, are created and evolve. The talk focuses on occasions where the ionosphere F-peak has been elevated above the C/NOFS satellite perigee of 400 km as solar activity has increased. In particular, during the equinox periods of 2011, the satellite consistently journeyed below the F-peak whenever the orbit was in the region of the South Atlantic anomaly after sunset. During these passes, data from the electric field and plasma density probes on the satellite have revealed two types of instabilities which had not previously been observed in the C/NOFS data set: The first is evidence for 400-500km-scale bottomside "undulations" that appear in the density and electric field data. In one case, these large scale waves are associated with a strong shear in the zonal E x B flow, as evidenced by variations in the meridional (outward) electric fields observed above and below the F-peak. These undulations are devoid of smaller scale structures in the early evening, yet appear at later local times along the same orbit associated with fully-developed spread-F with smaller scale structures. This suggests that they may be precursor waves for spread-F, driven by a collisional shear instability, following ideas advanced previously by researchers using data from the Jicamarca radar. A second result is the appearance of km-scale irregularities that are a common feature in the electric field and plasma density data that also appear when the satellite is near or below the F-peak at night. The vector electric field instrument on C/NOFS clearly shows that the electric field

  17. Quasi-optical design for systems to diagnose the electron temperature and density fluctuations on EAST

    Science.gov (United States)

    Cao, Qifo; Liu, Yong; Zhao, Hailin; Zhou, Tianfu; Ti, Ang; Hu, Liqun

    2016-11-01

    A system to simultaneously diagnose the electron temperature and density fluctuations is proposed for Experimental Advanced Superconducting Tokamak device. This system includes a common quasi-optical antenna, a correlation electron cyclotron emission (CECE) system that is used to measure the electron temperature fluctuations and a Doppler backscattering (DBS) system that is used to measure the electron density fluctuations. The frequency range of the proposed CECE system is 108-120 GHz, and this corresponds to a radial coverage of normalized radius ((R - R0)/a, R0 = 1850 mm, a = 450 mm) from 0.2 to 0.67 for the plasma operation with a toroidal magnetic field of 2.26 T. This paper focuses on the design of the quasi-optical antenna and aims at optimizing the poloidal resolution for different frequency bands. An optimum result gives the beam radius for the CECE system of 13-15 mm and this corresponds to a wave number range of kθ < 2.4 cm-1. The beam radius is 20-30 mm for V band (50-75 GHz) and 15-20 mm for W band (75-110 GHz).

  18. Irregular amalgams

    Directory of Open Access Journals (Sweden)

    James Stewart

    1986-01-01

    Full Text Available The amalgam of Lp and ℓq consists of those functions for which the sequence of Lp-norms over the intervals [n,n+1 is in ℓq. These spaces (Lp,ℓq have been studied in several recent papers. Here we replace the intervals [n,n+1 by a cover α={In;n∈Z} of the real line consisting of disjoint half-open intervals In each of the form [a,b, and investigate which properties of (Lp,ℓq carry over to these irregular amalgams (Lp,ℓqα. In particular, we study how (Lp,ℓqα varies as p, q, and α vary and determine conditions under which translation is continuous.

  19. Diagnosing the high density FRX-L Field Reversed Configuration plasma

    Science.gov (United States)

    Wurden, G. A.; Intrator, T. P.; Renneke, R. M.; Dorf, L. A.; Farrell, M. W.; Gray, T. K.; Hsu, S. C.; Lynn, A. G.; Ruden, E. L.

    2006-10-01

    The FRX-L plasma is a high pressure, high density, field reversed configuration (FRC), at n ˜1x10^16-1x10^17 cm-3, and hundreds of eV electron temperature. In order to study formation, equilibrium, transport, flow, and confinement issues, we have a suite of diagnostics. Standard plasma diagnostics include B-dot probes, magnetic flux loops, single and multi-channel visible spectroscopy, optical light tomography arrays, up to 8 filtered visible fibers (546 nm or 486 nm) and an 8-chord side-on HeNe interferometer. Recent diagnostic additions include AXUV bolometers, VUV spectroscopy using a methly salicylate fluorescer converter and optical multichannel analyzer (OMA), eight simultaneous axial views of visible spectra with a 0.3 meter spectrometer and Princeton Instruments PI-Max camera, two-foil end-on surface barrier diode soft x-ray measurements, a hard x-ray/neutron plastic scintillator/ PMT, and indium activation foils to detect time-integrated absolute DD neutron emission. We also discuss plans for a soft x-ray framing camera, using end-on optical access and consisting of a pinhole/fluorescer geometry coupled to a high resolution DiCam camera.

  20. ANÁLISIS Y ESTUDIO DEL DESEMPEÑO DEL CÓDIGO CHEQUEO DE PARIDAD DE BAJA DENSIDAD IRREGULAR EN UN CANAL DE LÍNEA ELÉCTRICA DE BAJA TENSIÓN ANALYSIS AND STUDY OF THE PERFORMANCE OF THE IRREGULAR LOW DENSITY PARITY CHECK CODE IN LOW VOLTAGE POWERLINE

    Directory of Open Access Journals (Sweden)

    Washington Fernández R

    2009-04-01

    Full Text Available En este trabajo se analiza y estudia el código chequeo de paridad de baja densidad irregular (LDPC, en un canal de línea eléctrica de baja tensión. Se analizan los modelos de ruido existentes para las líneas eléctricas de baja tensión. Se evalúa el desempeño del código LDPC irregular, en un canal de línea eléctrica de baja tensión para diferentes velocidades de transmisión (3, 10, 15 y 30 Mbps, considerando como parámetro de desempeño el BER versus SNR.In this work the irregular Low Density Parity Check code (LDPC is analyzed and studied, is used in a low voltage powerline. Noise models are analyzed for these low voltage lines. The performance of the LDPC code is evaluated in a low voltage line channel for rates of 3, 5, 15 and 30 Mbps, considering of BER vs SNR a parameter.

  1. What Causes Menstrual Irregularities?

    Science.gov (United States)

    ... Publications What causes menstrual irregularities? Skip sharing on social media links Share this: Page Content Menstrual irregularities can be caused by a variety of conditions, including pregnancy, hormonal imbalances, infections, malignancies, diseases, trauma, and certain ...

  2. Estimation of Power Spectrum Density Track Irregularities of Low-speed Maglev Railway Lines%低速磁浮轨道不平顺功率谱研究

    Institute of Scientific and Technical Information of China (English)

    张耿; 李杰; 杨子敬

    2011-01-01

    Track irregularity is the main excitation source to vibration of the maglev train, and it has direct influence on stability and ride quality of the train. The statistical specimens of track irregularities are collected from the TangShan low-speed maglev experimental line on the basis of the stationarity tests of the specimens, the Fast Fourier Transform(FFT) method was used to evaluate the spectra of the whole specimen space. Distribution of track irregularities in space wavelengths was found. Analysis results show that the structural parameters, installation precision and rolling technique of tracks are the main causes of track irregularity. Referring to the mature PSD( power spectrum density) expressions published athome and abroatl, the set fitting formulas of PSD for low-speed maglev railway lines were proposed. The parameter values of PSD fitting curves for low-speed maglev track irregularities were obtained by use of the damping curve-fitting algorithm in the least-squares sense. Significaul reference is provided to study on track irregularity PSD of low-speed maglev railway lines.%轨道不平顺是磁浮列车振动的主要激扰源,直接关系到列车运行的稳定性和舒适性.文章基于唐山低速磁浮试验线实测的轨道不平顺数据,采用周期图法进行样本空间的谱估计,得到轨道不平顺在各空间波长的分布.分析结果表明,轨道本身结构参数、轨道安装精度和F轨的轧制工艺是产生轨道不平顺的主要原因.参考国内外成熟的铁路轨道谱线表达形式,得到低速磁浮轨道谱的拟合曲线公式,应用阻尼最小二乘算法拟合轨道谱表达式的参数,对于研究我国磁浮轨道不平顺功率谱有重要的参考价值.

  3. Assessment of bone mineral density and bone metabolism in young male adults recently diagnosed with systemic lupus erythematosus in China.

    Science.gov (United States)

    Guo, Qinyue; Fan, Ping; Luo, Jing; Wu, Shufang; Sun, Hongzhi; He, Lan; Zhou, Bo

    2017-03-01

    Objective Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease. However, the exact mechanism underlying SLE-related osteopenia and osteoporosis in patients newly diagnosed with SLE remains unknown. Methods 60 male subjects with SLE aged 20-30 years were enrolled. Serum osteocalcin was examined as a marker of bone formation and type I collagen degradation products (β-crosslaps) as markers of bone resorption. Lumbar spine (L1-L4) and total hip bone mineral density (BMD) were determined by dual energy X-ray absorption (DXA). Results Among the 60 subjects with SLE at the time of diagnosis, the cohort showed a significant reduction of osteocalcin (12.62 ± 2.16 ng/mL), and serum β-crosslaps level (992.6 ± 162.6 pg/mL) was markedly elevated. Univariate correlation analyses revealed negative correlations between osteocalcin and SLEDAI, dsDNA antibody and β-crosslaps. A positive correlation was also observed between osteocalcin and C3, C4, 25-OH vitamin D, BMD L1-L4 and BMD total hip (see Table 3). Osteocalcin and β-crosslaps were strongly associated with SLE disease activity by multiple stepwise logistic regression analysis. Conclusion Osteocalcin was negatively associated with SLE disease activity, and β-crosslaps was positively associated with SLE disease activity, suggesting SLE disease activity itself directly contributed to the development of SLE-associated osteopenia and osteoporosis.

  4. Length measurements of mid-latitude scintillation irregularities

    Energy Technology Data Exchange (ETDEWEB)

    Macdougall, J.W. (Western Ontario, University, London (Canada))

    1992-04-01

    The lengths of irregularities which produce 150-MHz amplitude scintillations have been measured at 43 deg N, 81 deg W (geographic) using arrays of receivers with large spacings. The average length (major axis radius) of the irregularities was 6.1 km. This is much shorter than expected and implies that the measurements are of 'young' irregularities, less than 1 minute old. These irregularities appear to be a large, 25-50-percent perturbation of the background density. 8 refs.

  5. Star Formation in Irregular Galaxies.

    Science.gov (United States)

    Hunter, Deidre; Wolff, Sidney

    1985-01-01

    Examines mechanisms of how stars are formed in irregular galaxies. Formation in giant irregular galaxies, formation in dwarf irregular galaxies, and comparisons with larger star-forming regions found in spiral galaxies are considered separately. (JN)

  6. Shack-Hartmann Electron Densitometer (SHED): An Optical System for Diagnosing Free Electron Density in Laser-Produced Plasmas

    Science.gov (United States)

    2016-11-01

    the free electron density in USPL-created plasmas are limited in the number of space-time dimensions that can be measured simultaneously. One...profile, and c) parabolic density profile 2.1 Cylindrical Geometry This geometry is a first -order approximation of that created in the...Free Electron Density in Laser-Produced Plasmas by Anthony R Valenzuela Approved for public release; distribution is

  7. Multivariate irregular sampling theorem

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper,we prove a Marcinkiewicz-Zygmund type inequality for multivariate entire functions of exponential type with non-equidistant spaced sampling points. And from this result,we establish a multivariate irregular Whittaker-Kotelnikov-Shannon type sampling theorem.

  8. Multivariate irregular sampling theorem

    Institute of Scientific and Technical Information of China (English)

    CHEN GuangGui; FANG GenSun

    2009-01-01

    In this paper, we prove a Marcinkiewicz-Zygmund type inequality for multivariate entire functions of exponential type with non-equidistant spaced sampling points. And from this result, we establish a multivariate irregular Whittaker-Kotelnikov-Shannon type sampling theorem.

  9. Investigation of the 2p_{32}-3d_{52} line emission of Au;{53+}-Au;{69+} for diagnosing high energy density plasmas.

    Science.gov (United States)

    Brown, G V; Hansen, S B; Träbert, E; Beiersdorfer, P; Widmann, K; Chen, H; Chung, H K; Clementson, J H T; Gu, M F; Thorn, D B

    2008-06-01

    Measurements of the L -shell emission of highly charged gold ions were made under controlled laboratory conditions using the SuperEBIT electron beam ion trap, allowing detailed spectral observations of lines from Fe-like Au53+ through Ne-like Au69+ . Using atomic data from the Flexible Atomic Code, we have identified strong 3d_{52}-->2p_{32} emission features that can be used to diagnose the charge state distribution in high energy density plasmas, such as those found in the laser entrance hole of hot hohlraum radiation sources. We provide collisional-radiative calculations of the average ion charge Z as a function of temperature and density, which can be used to relate charge state distributions inferred from 3d_{52}-->2p_{32} emission features to plasma conditions, and investigate the effects of plasma density on calculated L -shell Au emission spectra.

  10. Understanding the Unique Equatorial Density Irregularities

    Science.gov (United States)

    2015-04-01

    HF Coherent Backscatter Radar (Blue Nile Radar) at Bahir Dar University in collaboration with AFRL in November 2014. Ionospheric empirical models such...equatorial plasma bubbles, Africa 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18, NUMBER OF PAGES 12 19a. NAME OF RESPONSIBLE...satellite signal receivers, VLF, VHF and so on in collaborating with institutions found outside Ethiopia. As a continua- tion of hosting instruments, HF

  11. HF-induced airglow structure as a proxy for ionospheric irregularity detection

    Science.gov (United States)

    Kendall, E. A.

    2013-12-01

    The High Frequency Active Auroral Research Program (HAARP) heating facility allows scientists to test current theories of plasma physics to gain a better understanding of the underlying mechanisms at work in the lower ionosphere. One powerful technique for diagnosing radio frequency interactions in the ionosphere is to use ground-based optical instrumentation. High-frequency (HF), heater-induced artificial airglow observations can be used to diagnose electron energies and distributions in the heated region, illuminate natural and/or artificially induced ionospheric irregularities, determine ExB plasma drifts, and measure quenching rates by neutral species. Artificial airglow is caused by HF-accelerated electrons colliding with various atmospheric constituents, which in turn emit a photon. The most common emissions are 630.0 nm O(1D), 557.7 nm O(1S), and 427.8 nm N2+(1NG). Because more photons will be emitted in regions of higher electron energization, it may be possible to use airglow imaging to map artificial field-aligned irregularities at a particular altitude range in the ionosphere. Since fairly wide field-of-view imagers are typically deployed in airglow campaigns, it is not well-known what meter-scale features exist in the artificial airglow emissions. Rocket data show that heater-induced electron density variations, or irregularities, consist of bundles of ~10-m-wide magnetic field-aligned filaments with a mean depletion depth of 6% [Kelley et al., 1995]. These bundles themselves constitute small-scale structures with widths of 1.5 to 6 km. Telescopic imaging provides high resolution spatial coverage of ionospheric irregularities and goes hand in hand with other observing techniques such as GPS scintillation, radar, and ionosonde. Since airglow observations can presumably image ionospheric irregularities (electron density variations), they can be used to determine the spatial scale variation, the fill factor, and the lifetime characteristics of

  12. Triglyceride to high-density lipoprotein cholesterol ratio and carotid intima-medial thickness in Chinese adolescents with newly diagnosed type 2 diabetes mellitus.

    Science.gov (United States)

    Li, Xin; Deng, You-Ping; Yang, Miao; Wu, Yu-Wen; Sun, Su-Xin; Sun, Jia-Zhong

    2016-03-01

    To investigate the relationship between triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio and carotid intima-medial thickness (CIMT) in Chinese youth and adolescents with newly diagnosed type 2 diabetes mellitus (T2DM). Ninety-eight subjects aged 10-24 yr with newly-diagnosed T2DM had general inflammation, anthropometric, laboratory and CIMT data collected, and were divided into three groups based on TG/HDL-C tertiles. There were no significant differences in gender, age, fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), and carotid arterial diameter (CAD) among the groups based on TG/HDL-C tertiles. Across TG/HDL-C tertiles, there was a significant progressive increase in body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), homeostasis model assessment-estimated insulin resistance (HOMA-IR), TG, total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C) and CIMT (all P < 0.01 or P < 0.05), while HDL-C was decreased significantly across the groups (P < 0.01). In general linear regression model, TG/HDL-C was an independent determinant of CIMT even after adjusting for BMI, SBP, DBP, TG, TC, LDL-C, HDL-C, HbA1c and HOMA-IR. TG/HDL-C ratio, the marker of small dense LDL particles, is an independent determinant of CIMT in Chinese youth and adolescents with newly diagnosed T2DM, and may be a simple and helpful tool in predicting the increased CIMT in such patients. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Irregular sampling for multivariate band-limited functions

    Institute of Scientific and Technical Information of China (English)

    SUN; Wenchang(孙文昌); ZHOU; Xingwei(周性伟)

    2002-01-01

    In this paper, we present some new algorithms to reconstruct multivariate band-limited functionsfrom irregular sampled values, which allow more arbitrary sampling points and lower sampling densities thanknown results.

  14. Diagnosing MS

    Science.gov (United States)

    ... a Local Support Group Ask an MS Navigator Edward M. Dowd Personal Advocate Program Connect with Peers ... Symptoms & Diagnosis Diagnosing MS Possible MS Clinically Isolated Syndrome (CIS) Newly Diagnosed Diagnosing Tools Other Conditions to ...

  15. Irregular conformal states and spectral curve: Irregular matrix model approach

    CERN Document Server

    Rim, Chaiho

    2016-01-01

    We present recent developments of irregular conformal conformal states. Irregular vertex operators and their adjoint are used to define the irregular conformal states and their Inner product. Free field formalism can be augmented by screening operators which provide more degrees of freedom. The inner product is conveniently given as partition function of a irregular matrix model. (Deformed) spectral curve is the loop equation of the matrix model at Nekrasov-Shatashivili limit. We present the details of analytic structure of the spectral curve for Virasoso symmetry and its extensions, W-symmetry and super-symmetry.

  16. How Do Health Care Providers Diagnose Menstrual Irregularities?

    Science.gov (United States)

    ... the vagina Sweet, M. G., Schmidt-Dalton, T. A., Weiss, P. M., & Madsen, K. P. (2012). Evaluation and management of abnormal uterine bleeding in premenopausal women. American Family Physician , 85, 35-43. [top] French, L. (2005). Dysmenorrhea. American Family Physician , 71, 285- ...

  17. Osteonecrosis Diagnosed on MR Images of the Knee. Relationship to reduced bone mineral density determined by high resolution peripheral quantitative CT

    Energy Technology Data Exchange (ETDEWEB)

    Zanetti, M.; Hodler, J. [Orthopedic Univ. Hospital Balgrist, Zuerich (Switzerland). Dept. of Radiology; Romero, J. [Orthopedic Univ. Hospital Balgrist, Zuerich (Switzerland). Dept. of Orthopedic Surgery; Dambacher, M.A. [Univ. Hospital Balgrist, Zuerich (Switzerland). Inst. of Physical Medicine and Rheumatology

    2003-09-01

    Purpose: To evaluate if osteonecrosis diagnosed on MR images of the knee relates to reduced bone mineral density (BMD) and may be caused by an insufficiency fracture. Material and Methods: Thirty-two consecutive patients (8 men, 24 women; age range 27-82 years, mean 62 years) with MR findings of osteonecrosis of the femoral or tibial condyle were prospectively included. Trabecular and cortical BMD were measured with high resolution peripheral quantitative CT in the non-dominant distal radius and the tibia of the involved extremity. One tibia was not measured due to posttraumatic deformity. Results: The mean trabecular BMD of the radius was 81% of the young-adult average peak BMD (range 19-160%). The mean cortical BMD in the radius was 86% (range 63-108%). The mean trabecular BMD in the tibia was 92% (range 28-160%). The mean cortical BMD in the tibia was 86% (range 49-132%). The values of the trabecular bone of the distal radius (tibia) were normal in 11 (15) patients, osteopenic in 12 (4), and osteoporotic in 9 (12), respectively. The cortical bone values of the distal radius (tibia) were normal in 12 (13) patients, osteopenic in 12 (12), and osteoporotic in 8 (6), respectively. Conclusion: Osteoporosis and osteopenia are commonly found in patients with osteonecrosis of the knee as diagnosed on MR images. This indicates that for some patients an insufficiency mechanism may be responsible for the MR findings. However, in the patients with normal bone density other reasons for osteonecrosis may be present.

  18. Irregular marriage: myth and reality

    OpenAIRE

    Gordon, Eleanor

    2013-01-01

    This article examines the historiography, the law, and the practice of irregular marriage in Britain. It argues that there has been a confusion of terms in the historiography of irregular marriage that has served to obscure its meaning, pattern, and incidence. Using evidence from Scotland where irregular marriage continued to be legally valid until 1939 (with one form remaining legally valid until 2006), the article argues that despite its legally valid status, the interpretation of what cons...

  19. Irregular-Time Bayesian Networks

    CERN Document Server

    Ramati, Michael

    2012-01-01

    In many fields observations are performed irregularly along time, due to either measurement limitations or lack of a constant immanent rate. While discrete-time Markov models (as Dynamic Bayesian Networks) introduce either inefficient computation or an information loss to reasoning about such processes, continuous-time Markov models assume either a discrete state space (as Continuous-Time Bayesian Networks), or a flat continuous state space (as stochastic dif- ferential equations). To address these problems, we present a new modeling class called Irregular-Time Bayesian Networks (ITBNs), generalizing Dynamic Bayesian Networks, allowing substantially more compact representations, and increasing the expressivity of the temporal dynamics. In addition, a globally optimal solution is guaranteed when learning temporal systems, provided that they are fully observed at the same irregularly spaced time-points, and a semiparametric subclass of ITBNs is introduced to allow further adaptation to the irregular nature of t...

  20. Analysis of irregularly distributed points

    DEFF Research Database (Denmark)

    Hartelius, Karsten

    1996-01-01

    The present thesis is on the analysis of irregularly distributed points. The main part of the thesis is concerned with enterpolating and restoration of irregularly distribyted points. The least squares methods of kriging and Kalman filtering and the Bayesian restoration method of iterated...... is described as a robust estimator which may be appled straightfor- wardly to a wide range of point patterns and processes when the correlation structure is known. We give a qualitative and quantitative comparison of kriging, Kalman filter and iterated conditional modes. The Kalman filter have in a case study...... and represents an interesting contextuel classifier. Extended Kalman filtering on the other hand seems to be well suited for interpolation in gradually changing environments. Bayesian restoration is applied to a point matching problem, which consists of matching a grid to an image of (irregularly) distributed...

  1. Lexical Semantics and Irregular Inflection

    Science.gov (United States)

    Huang, Yi Ting; Pinker, Steven

    2010-01-01

    Whether a word has an irregular inflection does not depend on its sound alone: compare lie-lay (recline) and lie-lied (prevaricate). Theories of morphology, particularly connectionist and symbolic models, disagree on which nonphonological factors are responsible. We test four possibilities: (1) Lexical effects, in which two lemmas differ in whether they specify an irregular form; (2) Semantic effects, in which the semantic features of a word become associated with regular or irregular forms; (3) Morphological structure effects, in which a word with a headless structure (e.g., a verb derived from a noun) blocks access to a stored irregular form; (4) Compositionality effects, in which the stored combination of an irregular word’s meaning (e.g., the verb’s inherent aspect) with the meaning of the inflection (e.g., pastness) doesn’t readily transfer to new senses with different combinations of such meanings. In four experiments, speakers were presented with existing and novel verbs and asked to rate their past-tense forms, semantic similarities, grammatical structure, and aspectual similarities. We found (1) an interaction between semantic and phonological similarity, coinciding with reported strategies of analogizing to known verbs and implicating lexical effects; (2) weak and inconsistent effects of semantic similarity; (3) robust effects of morphological structure, and (4) robust effects of aspectual compositionality. Results are consistent with theories of language that invoke lexical entries and morphological structure, and which differentiate the mode of storage of regular and irregular verbs. They also suggest how psycholinguistic processes have shaped vocabulary structure over history. PMID:21151703

  2. Cartography of irregularly shaped satellites

    Science.gov (United States)

    Batson, R. M.; Edwards, Kathleen

    1987-01-01

    Irregularly shaped satellites, such as Phobos and Amalthea, do not lend themselves to mapping by conventional methods because mathematical projections of their surfaces fail to convey an accurate visual impression of the landforms, and because large and irregular scale changes make their features difficult to measure on maps. A digital mapping technique has therefore been developed by which maps are compiled from digital topographic and spacecraft image files. The digital file is geometrically transformed as desired for human viewing, either on video screens or on hard copy. Digital files of this kind consist of digital images superimposed on another digital file representing the three-dimensional form of a body.

  3. Newly Diagnosed

    Science.gov (United States)

    ... Sites Podcasts QR Codes RSS Feeds Social Bookmarking Social Network Sites Text Messaging Twitter Video Games Video Sharing ... in care is similar to that of HIV-negative individuals. Additional Resources AIDSinfo – Just Diagnosed: Next ...

  4. Evolutionary Models of Irregular Warfare

    Science.gov (United States)

    2013-03-01

    G. (2010) Decentralize, adapt and cooperate. Nature 465:292-293. Sagarin, R. (2012) Learning From the Octopus : How Secrets from Nature Can Help Us...because the concepts map on to important features of modern irregular warfare. For example, small-scale behaviors are increasingly thought to

  5. Roots of Russian Irregular Warfare

    Science.gov (United States)

    2016-12-01

    concluded that the United States has a national policy gap in our own ability to wage “unconventional warfare in the gray zone.”3 That statement...advancing army—few have studied the irregular nature of the campaign waged against Napoleon. Napoleon’s overstretched logistics and the elusiveness of...94 Karl E. Meyer and Shareen Blair Brysac, Tournament of Shadows: The Great Game and the Race for Empire in Central Asia (Washington, DC: Basic

  6. Air Power in Irregular Warfare

    Science.gov (United States)

    2012-12-01

    Intelligence, Surveillance, and Reconnaisance IW Irregular Warfare JFC Joint Force Commander JP Joint Publication xii MCP Malayan Communist Party...being or acting in accord with laws , rules, or established custom.”5 Combined with the Clausewitzian definition of war as “an act of violence meant...Quarterly and Defence Journal , October, 1920), accessed March 21, 2012, http://usacac.army.mil/cac2/cgsc/carl/download/csipubs/lawrence.pdf, 17. 22 Bruce

  7. Artificial periodic irregularities in the auroral ionosphere

    Directory of Open Access Journals (Sweden)

    M.T. Rietveld

    Full Text Available Artificial periodic irregularities (API are produced in the ionospheric plasma by a powerful standing electromagnetic wave reflected off the F region. The resulting electron-density irregularities can scatter other high-frequency waves if the Bragg scattering condition is met. Such measurements have been performed at mid-latitudes for two decades and have been developed into a useful ionospheric diagnostic technique. We report here the first measurements from a high-latitude station, using the EISCAT heating facility near Tromsø, Norway. Both F-region and lower-altitude ionospheric echoes have been obtained, but the bulk of the data has been in the E and D regions with echoes extending down to 52-km altitude. Examples of API are shown, mainly from the D region, together with simultaneous VHF incoherent-scatter-radar (ISR data. Vertical velocities derived from the rate of phase change during the irregularity decay are shown and compared with velocities derived from the ISR. Some of the API-derived velocities in the 75–115-km height range appear consistent with vertical neutral winds as shown by their magnitudes and by evidence of gravity waves, while other data in the 50–70-km range show an unrealistically large bias. For a comparison with ISR data it has proved difficult to get good quality data sets overlapping in height and time. The initial comparisons show some agreement, but discrepancies of several metres per second do not yet allow us to conclude that the two techniques are measuring the same quantity. The irregularity decay time-constants between about 53 and 70 km are compared with the results of an advanced ion-chemistry model, and height profiles of recorded signal power are compared with model estimates in the same altitude range. The calculated amplitude shows good agreement with the data in that the maximum occurs at about the same height as that of the measured amplitude. The calculated time-constant agrees very well with the

  8. Vibrations of strongly irregular or fractal resonators

    Science.gov (United States)

    Sapoval, B.; Gobron, Th.

    1993-05-01

    It is shown on a specific example that fractal boundary conditions drastically alter the properties of wave excitations in space. The low-frequency part of the vibration spectrum of a finite-range fractal drum is computed using an analogy between the Helmoltz equation and the diffusion equation. The irregularity of the frontier is found to influence strongly the density of states at low frequency. The fractal perimeter generates a specific screening effect. Very near the frontier, the decrease of the wave form is related directly to the behavior of the harmonic measure. The possibility of localization of the vibrations is qualitatively discussed and we show that localized modes may exist at low frequencies if the geometrical structures possess narrow paths. Possible application of these results to the interpretation of thermal properties of binary glasses is briefly discussed.

  9. Irregular and regular LDPC codes with high spectrum efficiency modulation in image transmission over fading channel

    Institute of Scientific and Technical Information of China (English)

    Ma Piming; Yuan Dongfeng

    2005-01-01

    If the degree distribution is chosen carefully, the irregular low-density parity-check (LDPC) codes can outperform the regular ones. An image transmission system is proposed by combining regular and irregular LDPC codes with 16QAM/64QAM modulation to improve both efficiency and reliability. Simulaton results show that LDPC codes are good coding schemes over fading channel in image communication with lower system complexity. More over, irregular codes can obtain a code gain of about 0.7 dB compared with regular ones when BER is 10-4. So the irregular LDPC codes are more suitable for image transmission than the regular codes.

  10. Irregularity excitation associated with charged dust cloud boundary layers

    Science.gov (United States)

    Mahmoudian, A.; Scales, W. A.

    2012-02-01

    Irregularity generation associated with dust cloud expansion through a background plasma along a magnetic field is investigated. Because of the dust charging process, a boundary layer is produced, separating the dusty plasma generated and the background plasma. It is observed that under appropriate conditions, localized plasma irregularities may be generated in this boundary layer. Theoretical and computational models are used to study the evolution of relevant plasma instabilities thought to play a dominant role in irregularity production. An electron flow develops along the boundary layer of the dust cloud, and plasma irregularities are generated in response to this flow. Several aspects of the cloud's structure (thickness of the boundary layer, average particle size and density, collisional processes, and cloud expansion speed) and the ambient plasma are varied to determine the effect of these quantities on the resulting irregularities. The relevance of these results to past experimental observations in space and the laboratory for applications to the expansion of naturally or artificially created dust clouds is discussed.

  11. Lopsidedness in dwarf irregular galaxies

    CERN Document Server

    Heller, A B; Almoznino, E; Van Zee, L; Salzer, J J; Heller, Ana B.; Brosch, Noah; Almoznino, Elchanan; Zee, Liese van; Salzer, John J.

    2000-01-01

    We quantify the amplitude of the lopsidedness, the azimuthal angular asymmetry index, and the concentration of star forming regions, as represented by the distribution of the H$\\alpha$ emission, in a sample of 78 late-type irregular galaxies. We bin the observed galaxies in two groups representing blue compact galaxies (BCDs) and low surface brightness dwarf galaxies (LSBs). The light distribution is analysed with a novel algorithm, which allows detection of details in the light distribution pattern. We find that while the asymmetry of the underlying continuum light, representing the older stellar generations, is relatively small, the H$\\alpha$ emission is very asymmetric and is correlated in position angle with the continuum light. We test a model of random star formation over the extent of a galaxy by simulating HII regions in artificial dwarf galaxies. The implication is that random star formation over the full extent of a galaxy may be generated in LSB dwarf-irregular galaxies but not in BCD galaxies.

  12. SCION: CubeSat Mission Concept to Observe Midlatitude Small-Scale Irregularities and Scintillation

    Science.gov (United States)

    Heine, T.; Moldwin, M.

    2014-12-01

    The SCintillation and Ionospheric Occultation NanoSats (SCION) mission concept is to deploy two low-cost CubeSat spacecraft that maintain a separation distance measure scintillation and associated small-scale density irregularities in the midlatitude ionosphere. Each spacecraft is equipped with a dual frequency GPS receiver to measure total electron content (TEC) and the S4 scintillation index along raypaths from the receiver to the GPS constellation. Scintillation causing small-scale density irregularities are increasingly observed in the vicinity of large TEC gradients associated with storm enhanced density (SED) regions. Detection of irregularities of the scale that cause GPS and VHF scintillation has previously relied on assumptions about their structural stability and drift speed. Space-based, multipoint observations would provide broad, regional coverage and disambiguation of temporal and spatial density fluctuations in order to detect small-scale irregularities without these assumptions.

  13. C/NOFS Satellite Electric Field and Plasma Density Observations of Plasma Instabilities Below the Equatorial F-Peak -- Evidence for Approximately 500 km-Scale Spread-F "Precursor" Waves Driven by Zonal Shear Flow and km-Scale, Narrow-Banded Irregularities

    Science.gov (United States)

    Pfaff, R.; Freudenreich, H.; Klenzing, J.; Liebrecht, C.; Valladares, C.

    2011-01-01

    As solar activity has increased, the ionosphere F-peak has been elevated on numerous occasions above the C/NOFS satellite perigee of 400km. In particular, during the month of April, 2011, the satellite consistently journeyed below the F-peak whenever the orbit was in the region of the South Atlantic anomaly after sunset. During these passes, data from the electric field and plasma density probes on the satellite have revealed two types of instabilities which had not previously been observed in the C/NOFS data set (to our knowledge): The first is evidence for 400-500km-scale bottomside "undulations" that appear in the density and electric field data. In one case, these large scale waves are associated with a strong shear in the zonal E x B flow, as evidenced by variations in the meridional (outward) electric fields observed above and below the F-peak. These undulations are devoid of smaller scale structures in the early evening, yet appear at later local times along the same orbit associated with fully-developed spread-F with smaller scale structures. This suggests that they may be precursor waves for spread-F, driven by a collisional shear instability, following ideas advanced previously by researchers using data from the Jicamarca radar. A second new result (for C/NOFS) is the appearance of km-scale irregularities that are a common feature in the electric field and plasma density data that also appear when the satellite is below the F -peak at night. The vector electric field instrument on C/NOFS clearly shows that the electric field component of these waves is strongest in the zonal direction. These waves are strongly correlated with simultaneous observations of plasma density oscillations and appear both with, and without, evidence of larger-scale spread-F depletions. These km-scale, quasi-coherent waves strongly resemble the bottomside, sinusoidal irregularities reported in the Atmosphere Explorer satellite data set by Valladares et al. [JGR, 88, 8025, 1983

  14. C/NOFS Satellite Electric Field and Plasma Density Observations of Plasma Instabilities Below the Equatorial F-Peak -- Evidence for ~500 km-scale Spread-F "Precursor" Waves Driven by Zonal Shear Flow and km-Scale, Narrow-Banded Irregularities

    Science.gov (United States)

    Pfaff, R. F.; Freudenreich, H. T.; Klenzing, J. H.; Liebrecht, M. C.; Valladares, C. E.

    2011-12-01

    As solar activity has increased, the ionosphere F-peak has been elevated on numerous occasions above the C/NOFS satellite perigee of 400km. In particular, during the month of April, 2011, the satellite consistently journeyed below the F-peak whenever the orbit was in the region of the South Atlantic anomaly after sunset. During these passes, data from the electric field and plasma density probes on the satellite have revealed two types of instabilities which had not previously been observed in the C/NOFS data set (to our knowledge): The first is evidence for 400-500km-scale bottomside "undulations" that appear in the density and electric field data. In one case, these large scale waves are associated with a strong shear in the zonal E x B flow, as evidenced by variations in the meridional (outward) electric fields observed above and below the F-peak. These undulations are devoid of smaller scale structures in the early evening, yet appear at later local times along the same orbit associated with fully-developed spread-F with smaller scale structures. This suggests that they may be precursor waves for spread-F, driven by a collisional shear instability, following ideas advanced previously by researchers using data from the Jicamarca radar. A second new result (for C/NOFS) is the appearance of km-scale irregularities that are a common feature in the electric field and plasma density data that also appear when the satellite is below the F-peak at night. The vector electric field insrument on C/NOFS clearly shows that the electric field component of these waves is strongest in the zonal direction. These waves are strongly correlated with simultaneous observations of plasma density oscillations and appear both with, and without, evidence of larger-scale spread-F depletions. These km-scale, quasi-coherent waves strongly resemble the bottomside, sinusoidal irregularities reported in the Atmosphere Explorer satellite data set by Valladares et al. [JGR, 88, 8025, 1983]. We

  15. LDRD Report: Scheduling Irregular Algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Boman, Erik G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-10-01

    This LDRD project was a campus exec fellowship to fund (in part) Donald Nguyen’s PhD research at UT-Austin. His work has focused on parallel programming models, and scheduling irregular algorithms on shared-memory systems using the Galois framework. Galois provides a simple but powerful way for users and applications to automatically obtain good parallel performance using certain supported data containers. The naïve user can write serial code, while advanced users can optimize performance by advanced features, such as specifying the scheduling policy. Galois was used to parallelize two sparse matrix reordering schemes: RCM and Sloan. Such reordering is important in high-performance computing to obtain better data locality and thus reduce run times.

  16. The Dynamics of Equatorial F Layer Irregularities.

    Science.gov (United States)

    2014-09-26

    of irregularities rise through the ionosphere. The patch, after development, has the form of a banana with its long axis magnetic north-south. A...determine the geometrical form of these irregularities. If the irregularities were vertical sheets the maximum intensity would be noted when the ray path...was along the sheet as shown in Figure 6. Vertical sheets , conceived theoretically from upwelling plasma bubbles, were ruled out. Multiplying factors

  17. Diagnosing collisions of magnetized, high energy density plasma flows using a combination of collective Thomson scattering, Faraday rotation, and interferometry (invited).

    Science.gov (United States)

    Swadling, G F; Lebedev, S V; Hall, G N; Patankar, S; Stewart, N H; Smith, R A; Harvey-Thompson, A J; Burdiak, G C; de Grouchy, P; Skidmore, J; Suttle, L; Suzuki-Vidal, F; Bland, S N; Kwek, K H; Pickworth, L; Bennett, M; Hare, J D; Rozmus, W; Yuan, J

    2014-11-01

    A suite of laser based diagnostics is used to study interactions of magnetised, supersonic, radiatively cooled plasma flows produced using the Magpie pulse power generator (1.4 MA, 240 ns rise time). Collective optical Thomson scattering measures the time-resolved local flow velocity and temperature across 7-14 spatial positions. The scattering spectrum is recorded from multiple directions, allowing more accurate reconstruction of the flow velocity vectors. The areal electron density is measured using 2D interferometry; optimisation and analysis are discussed. The Faraday rotation diagnostic, operating at 1053 nm, measures the magnetic field distribution in the plasma. Measurements obtained simultaneously by these diagnostics are used to constrain analysis, increasing the accuracy of interpretation.

  18. Diagnosing collisions of magnetized, high energy density plasma flows using a combination of collective Thomson scattering, Faraday rotation, and interferometry (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Swadling, G. F., E-mail: swadling@imperial.ac.uk; Lebedev, S. V.; Hall, G. N.; Patankar, S.; Stewart, N. H.; Smith, R. A.; Burdiak, G. C.; Grouchy, P. de; Skidmore, J.; Suttle, L.; Suzuki-Vidal, F.; Bland, S. N.; Kwek, K. H.; Pickworth, L.; Bennett, M.; Hare, J. D. [Plasma Physics Group, Imperial College, London SW6 7LZ (United Kingdom); Harvey-Thompson, A. J. [Sandia National Laboratory, Albuquerque, New Mexico 87185-1193 (United States); Rozmus, W. [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); Yuan, J. [Key Laboratory of Pulsed Power, Institute of Fluid Physics, CAE, Mianyang 621900 (China)

    2014-11-15

    A suite of laser based diagnostics is used to study interactions of magnetised, supersonic, radiatively cooled plasma flows produced using the Magpie pulse power generator (1.4 MA, 240 ns rise time). Collective optical Thomson scattering measures the time-resolved local flow velocity and temperature across 7–14 spatial positions. The scattering spectrum is recorded from multiple directions, allowing more accurate reconstruction of the flow velocity vectors. The areal electron density is measured using 2D interferometry; optimisation and analysis are discussed. The Faraday rotation diagnostic, operating at 1053 nm, measures the magnetic field distribution in the plasma. Measurements obtained simultaneously by these diagnostics are used to constrain analysis, increasing the accuracy of interpretation.

  19. Low-density lipoprotein and noncalcified coronary plaque composition in patients with newly diagnosed coronary artery disease on computed tomographic angiography.

    Science.gov (United States)

    Cheng, Victor Y; Wolak, Arik; Gutstein, Ariel; Gransar, Heidi; Wong, Nathan D; Dey, Damini; Thomson, Louise E J; Hayes, Sean W; Friedman, John D; Slomka, Piotr J; Berman, Daniel S

    2010-03-15

    We sought to determine significant relations between atherogenic lipoproteins and the contribution of calcified plaque (CP), mixed plaque (MP), and noncalcified plaque (NCP) to the total plaque (TP) burden in patients without previous coronary artery disease. From 823 adult patients without previously established coronary artery disease (52% receiving statin therapy, 34% asymptomatic) but with visible coronary plaque on coronary computed tomographic angiography, we obtained segmental CP, MP, NCP, and TP counts from contrast-enhanced, electrocardiographic-gated computed tomography. Multivariate linear regression analysis was used to determine the associations of clinical factors and lipoprotein levels to CP, MP, and NCP counts and CP/TP, MP/TP, and NCP/TP count ratios. Age, male gender, diabetes, smoking, and statin therapy were significantly associated with the CP count (p NCP counts (all p values NCP/TP ratios, including an inverse association with CP/TP (p = 0.008) and a positive association with MP/TP (p = 0.032). Analyses using non-high-density lipoprotein cholesterol in place of LDL cholesterol yielded similar results. In conclusion, among the traditional clinical factors used to estimate cardiovascular event risk, LDL cholesterol is associated with an increased MP and NCP burden and is the sole variable that independently predicted relative predominance of CP, MP, and NCP, suggesting a potentially important role for lipoprotein levels in modulating the type of detectable coronary arterial plaque.

  20. On Decoding Irregular Tanner Codes

    CERN Document Server

    Even, Guy

    2011-01-01

    We present a new combinatorial characterization for local-optimality of a codeword in irregular Tanner codes. This characterization is a generalization of [Arora, Daskalakis, Steurer; 2009] and [Vontobel; 2010]. The main novelty in this characterization is that it is based on a conical combination of subtrees in the computation trees. These subtrees may have any degree in the local-code nodes and may have any height (even greater than the girth). We prove that local-optimality in this new characterization implies Maximum-Likelihood (ML) optimality and LP-optimality. We also show that it is possible to compute efficiently a certificate for the local-optimality of a codeword given the channel output. We apply this characterization to regular Tanner codes. We prove a lower bound on the noise threshold in channels such as BSC and AWGNC. When the noise is below this lower bound, the probability that LP decoding fails diminishes doubly exponentially in the girth of the Tanner graph. We use local optimality also to ...

  1. Ethical issues in irregular migration research

    NARCIS (Netherlands)

    Duvell, F.; Triandafyllidou, A.; Vollmer, B.

    2008-01-01

    This paper is concerned with the ethical issues arising for researchers engaged in the study of irregular migration. Irregular migration is by definition an elusive phenomenon as it takes place in violation of the law and at the margins of society. This very nature of the phenomenon raises important

  2. Ethical issues in irregular migration research

    NARCIS (Netherlands)

    Duvell, F.; Triandafyllidou, A.; Vollmer, B.

    2008-01-01

    This paper is concerned with the ethical issues arising for researchers engaged in the study of irregular migration. Irregular migration is by definition an elusive phenomenon as it takes place in violation of the law and at the margins of society. This very nature of the phenomenon raises important

  3. DESIGN OF IRREGULAR LDPC CODE WITH UNEQUAL ERROR PROTECTION PROPERTY AND ITS PERFORMANCE ANALYSIS ON IMAGE TRANSMISSION

    Institute of Scientific and Technical Information of China (English)

    Wang Ruihua; Yin Liuguo; Yu Quan; Lu Jianhua

    2005-01-01

    Based on the property that high degree variable nodes within an irregular LowDensity Parity-Check (LDPC) code have more powerful error-correcting capability than that of low degree variable nodes, a group of irregular LDPC codes with Unequal Error Protection (UEP)property is designed in this letter. Simulation results show that the transmission quality of the image may be effectively improved with this class of irregular LDPC code.

  4. Capture of Irregular Satellites at Jupiter

    CERN Document Server

    Nesvorny, D; Deienno, R

    2014-01-01

    The irregular satellites of outer planets are thought to have been captured from heliocentric orbits. The exact nature of the capture process, however, remains uncertain. We examine the possibility that irregular satellites were captured from the planetesimal disk during the early Solar System instability when encounters between the outer planets occurred (Nesvorny, Vokrouhlicky & Morbidelli 2007, AJ 133; hereafter NVM07). NVM07 already showed that the irregular satellites of Saturn, Uranus and Neptune were plausibly captured during planetary encounters. Here we find that the current instability models present favorable conditions for capture of irregular satellites at Jupiter as well, mainly because Jupiter undergoes a phase of close encounters with an ice giant. We show that the orbital distribution of bodies captured during planetary encounters provides a good match to the observed distribution of irregular satellites at Jupiter. The capture efficiency for each particle in the original transplanetary d...

  5. Low-density lipoprotein subfraction, carotid artery intima-media thickness, nitric oxide, and tumor necrosis factor alpha are associated with newly diagnosed ischemic stroke

    Directory of Open Access Journals (Sweden)

    Medine Cumhur Cure

    2013-01-01

    Full Text Available Objectives: Small dense (sd low-density lipoprotein (LDL, tumor necrosis factor (TNF alpha (a, and nitric oxide (NO have recently emerged as important stroke risk factors. The aim of the study was to investigate the effects of increased levels of small LDL particle size, TNF-a and NO on the developed ischemic stroke and increased carotid artery intima-media thickness (CIMT. Materials and Methods: A total of 29 women and 25 men (a total of 54 ischemic stroke patients and a similar age group of 50 controls (29 females and 21 males were included in the study. CIMT, C-reactive protein (CRP, TNF-a, NO, and lipid subfraction test of the two groups were measured. Results: The mean LDL particle size was smaller in patients with stroke than in the controls (26.8 ± 0.31 nm vs. 27.0 ± 0.31 nm, P = 0.003. sd-LDL, TNF-a, NO, CRP, right CIMT, and left CIMT were higher in patients with stroke than in the controls (respectively; 8.2 ± 7.8 mg/dL vs. 3.3 ± 3.5 mg/dL, P < 0.001;75.6 ± 25.0 pg/mL vs. 65.4 ± 9.1 pg/mL, P = 0.009;76.4 ± 53.3 mmol/L vs. 41.5 ± 27.0 mmol/L, P < 0.001;1.9 ± 2.6 mm vs. 0.4 ± 0.3 mm P < 0.001;0.97 ± 0.38 mm vs. 0.83 ± 0.15 mm, P = 0.007;1.04 ± 0.44 mm vs. 0.87 ± 0.19 mm, P = 0.010. Conclusion: These results show that sd-LDL is independently associated with the incidence of stroke and may be a risk factor in the development of stroke. In addition, TNF-a, NO, right CIMT, and left CIMT may be a risk factor in the development of ischemic stroke.

  6. Influence of Electric Charge and Modified Gravity on Density Irregularities

    CERN Document Server

    Bhatti, M Zaeem Ul Haq

    2016-01-01

    This work aims to identify some inhomogeneity factors for plane symmetric topology with anisotropic and dissipative fluid under the effects of both electromagnetic field as well as Palatini $f(R)$ gravity. We construct the modified field equations, kinematical quantities and mass function to continue our analysis. We have explored the dynamical quantities, conservation equations and modified Ellis equations with the help of a viable $f(R)$ model. Some particular cases are discussed with and without dissipation to investigate the corresponding inhomogeneity factors. For non-radiating scenario, we examine such factors with dust, isotropic and anisotropic matter in the presence of charge. For dissipative fluid, we investigate the inhomogeneity factor with charged dust cloud. We conclude that electromagnetic field increases the inhomogeneity in matter while the extra curvature terms make the system more homogeneous with the evolution of time.

  7. Influence of electric charge and modified gravity on density irregularities

    Energy Technology Data Exchange (ETDEWEB)

    Bhatti, M.Z. Ul Haq; Yousaf, Z. [University of the Punjab, Department of Mathematics, Lahore (Pakistan)

    2016-04-15

    This work aims to identify some inhomogeneity factors for a plane symmetric topology with anisotropic and dissipative fluid under the effects of both electromagnetic field as well as Palatini f(R) gravity. We construct the modified field equations, kinematical quantities, and mass function to continue our analysis. We have explored the dynamical quantities, conservation equations and modified Ellis equations with the help of a viable f(R) model. Some particular cases are discussed with and without dissipation to investigate the corresponding inhomogeneity factors. For a non-radiating scenario, we examine such factors as dust, and isotropic and anisotropic matter in the presence of charge. For a dissipative fluid, we investigate the inhomogeneity factor with a charged dust cloud. We conclude that the electromagnetic field increases the inhomogeneity in matter while the extra curvature terms make the system more homogeneous with the evolution of time. (orig.)

  8. Capture of irregular satellites at Jupiter

    Energy Technology Data Exchange (ETDEWEB)

    Nesvorný, David; Vokrouhlický, David; Deienno, Rogerio [Department of Space Studies, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States)

    2014-03-20

    The irregular satellites of outer planets are thought to have been captured from heliocentric orbits. The exact nature of the capture process, however, remains uncertain. We examine the possibility that irregular satellites were captured from the planetesimal disk during the early solar system instability when encounters between the outer planets occurred. Nesvorný et al. already showed that the irregular satellites of Saturn, Uranus, and Neptune were plausibly captured during planetary encounters. Here we find that the current instability models present favorable conditions for capture of irregular satellites at Jupiter as well, mainly because Jupiter undergoes a phase of close encounters with an ice giant. We show that the orbital distribution of bodies captured during planetary encounters provides a good match to the observed distribution of irregular satellites at Jupiter. The capture efficiency for each particle in the original transplanetary disk is found to be (1.3-3.6) × 10{sup –8}. This is roughly enough to explain the observed population of jovian irregular moons. We also confirm Nesvorný et al.'s results for the irregular satellites of Saturn, Uranus, and Neptune.

  9. Multiscale Modeling of Ionospheric Irregularities

    Science.gov (United States)

    2014-10-22

    differential equations by using a predictor- corrector formulation. The high-frequency acoustic modes would severely limit the RK3 time step. We use...thermodynamic, density and chemistry fields are fed back with an average from within the entire coarse grid point, and the horizontal momentum variables

  10. A final report to the Laboratory Directed Research and Development committee on Project 93-ERP-075: ``X-ray laser propagation and coherence: Diagnosing fast-evolving, high-density laser plasmas using X-ray lasers``

    Energy Technology Data Exchange (ETDEWEB)

    Wan, A.S.; Cauble, R.; Da Silva, L.B.; Libby, S.B.; Moreno, J.C.

    1996-02-01

    This report summarizes the major accomplishments of this three-year Laboratory Directed Research and Development (LDRD) Exploratory Research Project (ERP) entitled ``X-ray Laser Propagation and Coherence: Diagnosing Fast-evolving, High-density Laser Plasmas Using X-ray Lasers,`` tracking code 93-ERP-075. The most significant accomplishment of this project is the demonstration of a new laser plasma diagnostic: a soft x-ray Mach-Zehnder interferometer using a neonlike yttrium x-ray laser at 155 {angstrom} as the probe source. Detailed comparisons of absolute two-dimensional electron density profiles obtained from soft x-ray laser interferograms and profiles obtained from radiation hydrodynamics codes, such as LASNEX, will allow us to validate and benchmark complex numerical models used to study the physics of laser-plasma interactions. Thus the development of soft x-ray interferometry technique provides a mechanism to probe the deficiencies of the numerical models and is an important tool for, the high-energy density physics and science-based stockpile stewardship programs. The authors have used the soft x-ray interferometer to study a number of high-density, fast evolving, laser-produced plasmas, such as the dynamics of exploding foils and colliding plasmas. They are pursuing the application of the soft x-ray interferometer to study ICF-relevant plasmas, such as capsules and hohlraums, on the Nova 10-beam facility. They have also studied the development of enhanced-coherence, shorter-pulse-duration, and high-brightness x-ray lasers. The utilization of improved x-ray laser sources can ultimately enable them to obtain three-dimensional holographic images of laser-produced plasmas.

  11. Irregular Variability In Kepler Photometry

    Science.gov (United States)

    Schlecker, Martin

    2016-12-01

    The transit method is the most successful tool for exoplanet discovery to date. With more than half of all known exoplanets discovered by Kepler using this method, the mission also revealed a number of objects with dimming events that defy the common explanations, the most prominent being KIC 8462852 aka ``Tabby's star''. I embarked on a search for objects with such irregular transit signatures in the data of K2, the two-wheeled successor mission of Kepler. My method is a combination of automated pre-selection of targets showing downward flux excursions and visual light curve inspection of the selected subset comprising about SI{1.5}% of the initial sample. In addition, I developed a tool to constrain the effective temperature of a planet-hosting star from photometry alone. This software finds broad application in any science case where a photometric spectral type estimate is necessary. I used existing transit models and Bayesian inference to perform a Markov Chain Monte Carlo (MCMC) analysis of a planetary candidate I discovered. This putative gas giant is in a SI{1.32}day circular orbit with an exceptionally tight orbital radius of a ≈ 0.012 AU. My analysis revealed a scaled planetary radius of R_{p}/R_star = 0.0927±0.0026 and an edge-on orientation with an inclination i=89.8+3.0-3.4. EPIC 217393088.01 is one of the closest-orbiting exoplanets ever detected and the first giant planet with such a small orbital radius. An additional major finding of my search is EPIC 220262993, which exhibits aperiodic, asymmetric dips in flux with rapid dimming rates and up to SI{˜25}% depth, lasting for SIrange{2}{4} day. In previous works based on optical and mid-infrared photometry, this object was inconsistently classified as a possible quasar or a white dwarf. We conducted follow-up observations both photometrically with GROND on the MPI/ESO SI{2.2} meter telescope in La Silla (Chile) and spectroscopically with FIRE on the Magellan/Baade SI{6.5} meter telescope. With

  12. NOTE - Meiotic irregularities in Capsicum L. species

    Directory of Open Access Journals (Sweden)

    Margarete Magalhães Souza

    2012-01-01

    Full Text Available Cytogenetic and pollen viability (PV studies were performed in pepper accessions, Capsicum chinense and Capsicum baccatum. Irregularities such as laggard and univalent chromosomes, bridges, problems in the spindle fibers and cytomixis were observed, especially in C. baccatum which was the most unstable genotype. In the post-meiotic products, irregularities were observed, on average, at 20 % of the microspores in C. baccatum and 17 % in C. chinense. PV in C. baccatum was below 70 %, while in C. chinense, it was above 80 %. Meiotic irregularities in Capsicum, mainly in C. baccatum, considering the low PV estimated, were significant but not impeditive for fertilization.

  13. Robust Spectral Estimation of Track Irregularity

    Institute of Scientific and Technical Information of China (English)

    Fu Wenjuan; Chen Chunjun

    2005-01-01

    Because the existing spectral estimation methods for railway track irregularity analysis are very sensitive to outliers, a robust spectral estimation method is presented to process track irregularity signals. The proposed robust method is verified using 100 groups of clean/contaminated data reflecting he vertical profile irregularity taken from Bejing-Guangzhou railway with a sampling frequency of 33 data every 10 m, and compared with the Auto Regressive (AR) model. The experimental results show that the proposed robust estimation is resistible to noise and insensitive to outliers, and is superior to the AR model in terms of efficiency, stability and reliability.

  14. The irregularity of two types of trees

    OpenAIRE

    Liu, Yang; Li, Jianxi; Chee, Wai

    2015-01-01

    The irregularity of a graph G is defined as the sum of weights |d(u) − d(v)| of all edges uv of G, where d(u) and d(v) are the degrees of the vertices u and v in G, respectively. In this paper, some structural properties on trees with maximum (or minimum) irregularity among trees with given degree sequence and trees with given branching number are explored, respectively. Moreover, the corresponding trees with maximum (or minimum) irregularity are also found, respectively.

  15. The K-Spectrum of Ionospheric Irregularities

    DEFF Research Database (Denmark)

    D'Angelo, N.; Pécseli, Hans; Petersen, P. I.

    1975-01-01

    Laboratory measurements in a cesium plasma device indicate that the wave number (power) spectrum of irregularities produced by the Farley instability is of the type P(K) ∝ K −β, where β ≃ 3.5-3.8.......Laboratory measurements in a cesium plasma device indicate that the wave number (power) spectrum of irregularities produced by the Farley instability is of the type P(K) ∝ K −β, where β ≃ 3.5-3.8....

  16. Wideband irregular-shaped fractal antennas

    OpenAIRE

    Kolesov, V. V.; Krupenin, S. V.

    2007-01-01

    This paper proposes an algorithm of generating fully reproducible irregular fractal structures for antenna design. Three types of pseudorandom fractal clusters are introduced. The multi-frequency behavior of the irregular-shaped fractal antennas is studied by means of numerical analysis. The antenna behavior is studied under feeder displacement. As shown by numerical results feeder displacements allow one to control the spatial-frequency antenna characteristics.

  17. Magnetic fields in Local Group dwarf irregulars

    Science.gov (United States)

    Chyży, K. T.; Weżgowiec, M.; Beck, R.; Bomans, D. J.

    2011-05-01

    Aims: We wish to clarify whether strong magnetic fields can be effectively generated in typically low-mass dwarf galaxies and to assess the role of dwarf galaxies in the magnetization of the Universe. Methods: We performed a search for radio emission and magnetic fields in an unbiased sample of 12 Local Group (LG) irregular and dwarf irregular galaxies with the 100-m Effelsberg telescope at 2.64 GHz. Three galaxies were detected. A higher frequency (4.85 GHz) was used to search for polarized emission in five dwarfs that are the most luminous ones in the infrared domain, of which three were detected. Results: Magnetic fields in LG dwarfs are weak, with a mean value of the total field strength of regulated mainly by the star-formation surface density (with the power-law exponent of 0.30 ± 0.04) or by the gas surface density (with the exponent 0.47 ± 0.09). In addition, we find systematically stronger fields in objects of higher global star-formation rate. The dwarf galaxies follow a similar far-infrared relationship (with a slope of 0.91 ± 0.08) to that determined for high surface brightness spiral galaxies. The magnetic field strength in dwarf galaxies does not correlate with their maximum rotational velocity, indicating that a small-scale rather than a large-scale dynamo process is responsible for producting magnetic fields in dwarfs. If magnetization of the Universe by galactic outflows is coeval with its metal enrichment, we show that more massive objects (such as Lyman break galaxies) can efficiently magnetize the intergalactic medium with a magnetic field strength of about 0.8 nG out to a distance of 160-530 kpc at redshifts 5-3, respectively. Magnetic fields that are several times weaker and shorter magnetization distances are expected for primordial dwarf galaxies. We also predict that most star-forming local dwarfs might have magnetized their surroundings up to a field strength about 0.1 μG within about a 5 kpc distance. Conclusions: Strong magnetic

  18. Locating irregularly shaped clusters of infection intensity

    Directory of Open Access Journals (Sweden)

    Niko Yiannakoulias

    2010-05-01

    Full Text Available Patterns of disease may take on irregular geographic shapes, especially when features of the physical environment influence risk. Identifying these patterns can be important for planning, and also identifying new environmental or social factors associated with high or low risk of illness. Until recently, cluster detection methods were limited in their ability to detect irregular spatial patterns, and limited to finding clusters that were roughly circular in shape. This approach has less power to detect irregularly-shaped, yet important spatial anomalies, particularly at high spatial resolutions. We employ a new method of finding irregularly-shaped spatial clusters at micro-geographical scales using both simulated and real data on Schistosoma mansoni and hookworm infection intensities. This method, which we refer to as the “greedy growth scan”, is a modification of the spatial scan method for cluster detection. Real data are based on samples of hookworm and S. mansoni from Kitengei, Makueni district, Kenya. Our analysis of simulated data shows how methods able to find irregular shapes are more likely to identify clusters along rivers than methods constrained to fixed geometries. Our analysis of infection intensity identifies two small areas within the study region in which infection intensity is elevated, possibly due to local features of the physical or social environment. Collectively, our results show that the “greedy growth scan” is a suitable method for exploratory geographical analysis of infection intensity data when irregular shapes are suspected, especially at micro-geographical scales.

  19. How Are Arrhythmias Diagnosed?

    Science.gov (United States)

    ... page from the NHLBI on Twitter. How Are Arrhythmias Diagnosed? Arrhythmias can be hard to diagnose, especially the types ... symptoms every once in a while. Doctors diagnose arrhythmias based on medical and family histories, a physical ...

  20. Affine density in wavelet analysis

    CERN Document Server

    Kutyniok, Gitta

    2007-01-01

    In wavelet analysis, irregular wavelet frames have recently come to the forefront of current research due to questions concerning the robustness and stability of wavelet algorithms. A major difficulty in the study of these systems is the highly sensitive interplay between geometric properties of a sequence of time-scale indices and frame properties of the associated wavelet systems. This volume provides the first thorough and comprehensive treatment of irregular wavelet frames by introducing and employing a new notion of affine density as a highly effective tool for examining the geometry of sequences of time-scale indices. Many of the results are new and published for the first time. Topics include: qualitative and quantitative density conditions for existence of irregular wavelet frames, non-existence of irregular co-affine frames, the Nyquist phenomenon for wavelet systems, and approximation properties of irregular wavelet frames.

  1. Restructuring surface tessellation with irregular boundary conditions

    Directory of Open Access Journals (Sweden)

    Tsung-Hsien Wang

    2014-12-01

    Full Text Available In this paper, the surface tessellation problem is explored, in particular, the task of meshing a surface with the added consideration of incorporating constructible building components. When a surface is tessellated into discrete counterparts, certain unexpected conditions usually occur at the boundary of the surface, in particular, when the surface is being trimmed. For example, irregularly shaped panels form at the trimmed edges. To reduce the number of irregular panels that may form during the tessellation process, this paper presents an algorithmic approach to restructuring the surface tessellation by investigating irregular boundary conditions. The objective of this approach is to provide an alternative way for freeform surface manifestation from a well-structured discrete model of the given surface.

  2. Optimized puncturing distributions for irregular non-binary LDPC codes

    CERN Document Server

    Gorgoglione, Matteo; Declercq, David

    2010-01-01

    In this paper we design non-uniform bit-wise puncturing distributions for irregular non-binary LDPC (NB-LDPC) codes. The puncturing distributions are optimized by minimizing the decoding threshold of the punctured LDPC code, the threshold being computed with a Monte-Carlo implementation of Density Evolution. First, we show that Density Evolution computed with Monte-Carlo simulations provides accurate (very close) and precise (small variance) estimates of NB-LDPC code ensemble thresholds. Based on the proposed method, we analyze several puncturing distributions for regular and semi-regular codes, obtained either by clustering punctured bits, or spreading them over the symbol-nodes of the Tanner graph. Finally, optimized puncturing distributions for non-binary LDPC codes with small maximum degree are presented, which exhibit a gap between 0.2 and 0.5 dB to the channel capacity, for punctured rates varying from 0.5 to 0.9.

  3. Spelling Pronunciations: Transforming Irregularity into Regularity

    Science.gov (United States)

    Landerl, Karin; Thaler, Verena; Reitsma, Pieter

    2008-01-01

    In a 10-day training, the efficacy of spelling pronunciations on German speaking 5th-graders' spelling skills for irregular words was examined. Poor spellers were less efficient in learning the spelling pronunciations than age-adequate spellers. On post-tests, 1 week after the last training day and between 5 and 12 weeks after post-test 1, poor…

  4. Informal labor and irregular migrant workers

    NARCIS (Netherlands)

    M.J. van Meeteren (Masja)

    2013-01-01

    textabstractIrregular migrants, also referred to as “undocumented migrants” or “illegal migrants,” are immigrants who do not have legal permission to stay in the country they have migrated to and frequently take on informal and precarious employment. They may have entered the country legally – on a

  5. Color Survey of the Irregular Planetary Satellites

    Science.gov (United States)

    Graykowski, Ariel; Jewitt, David

    2016-10-01

    Irregular satellites are characterized by their larger orbital distance from their planet, their high eccentricity and their high inclination, all indicating that they were captured. However, the mechanism of capture and the location of origin of the satellites remain unknown. We are conducting a photometric survey of the irregular satellites of the giant planets using the LRIS instrument on the 10-meter telescope at the Keck Observatory in Hawaii. The measured colors will be compared to other planetary bodies in search for similarities and differences that may reflect upon the origin of the satellites. For example, if irregular satellites were captured from the Kuiper Belt then some should contain the ultrared material that is common in the trans-Neptunian and Centaur populations. If the irregular satellites of Jupiter were captured from the same source population as the Jovian Trojans, then it is natural to expect that the surface properties of satellites and Trojans should be the same. We will present initial results of this work.

  6. default and irregular attendance at treatment centres

    African Journals Online (AJOL)

    Leprosy control in the post leprosaria abolition years in Nigeria: Reasons for default and irregular ... leprosy seen at the four leprosy clinics in Anambra State in a face to face interview. ..... India, 1974; 46: 46-48. 7. Leonard G, Sangure A, ...

  7. Enhanced wave absorption through irregular interfaces

    Science.gov (United States)

    Félix, S.; Sapoval, B.; Filoche, M.; Asch, M.

    2009-01-01

    The diffraction and absorption of waves by a system with both absorbing properties and irregular geometry is an open physical problem. A more reachable and closely related question is the understanding of wave oscillations in confined systems containing an absorbing material with an irregular shape. This has to be solved to understand why anechoic chambers (electromagnetic or acoustic) do work better with irregular absorbing walls. The answer to this question could also be used in other fields such as light or microwave absorption, or also to improve the performances of break-waters in order to damp sea-waves. It is found here that, in resonators containing an irregular shaped absorbent material, there appears a new type of mode localization. This phenomemon, that we call "astride" localization, describes the fact that these modes exist in both the lossless and the lossy regions. It is these modes that are particularly efficient in dissipating the energy of waves excited in the non-absorbing region.

  8. Spelling Pronunciations: Transforming Irregularity into Regularity

    Science.gov (United States)

    Landerl, Karin; Thaler, Verena; Reitsma, Pieter

    2008-01-01

    In a 10-day training, the efficacy of spelling pronunciations on German speaking 5th-graders' spelling skills for irregular words was examined. Poor spellers were less efficient in learning the spelling pronunciations than age-adequate spellers. On post-tests, 1 week after the last training day and between 5 and 12 weeks after post-test 1, poor…

  9. Acoustic and Linguistic Interdependencies of Irregular Phonation

    Science.gov (United States)

    2010-05-01

    falther forward subsystems. The subglottal subsystem, including the abdominal muscles, intercostals , diaphragm, lungs, branching airways, and trachea...labeled prosodically, which limits us to acoustic and phonetic deductions about irregular phonation. TIMIT was developed as a joint eff0l1 between

  10. Photometric Survey of the Irregular Satellites

    CERN Document Server

    Grav, T; Gladman, B; Aksnes, K; Grav, Tommy; Holman, Matthew J.; Gladman, Brett; Aksnes, Kaare

    2003-01-01

    We present BVRI colors of 13 Jovian and 8 Saturnian irregular satellites obtained with the 2.56m Nordic Optical Telescope on La Palma, the 6.5m Magellan Baade Telescope on La Campanas, and the 6m MMT on Mt. Hopkins. The observations were performed between December 2001 to March 2002. Nearly all of the known irregular satellites can be divided into two distinct classes based on their colors. One, the grey color class, has the similar colors to the C-type asteroid, and the other, the light red color class, has colors similar to P/D-type asteroids. We also find at least one object, the Jovian irregular J XXIII Kalyke, that has colors similar to the red colored Centaurs/TNOs, although its classification is unsecure. We also find that there is a correlation between the physical properties and dynamical properties of the irregular satellites. Most of the dynamical clusters have homogeneous colors, which points to single homogeneous progenitors being cratered or fragmented as the source of each individual cluster. T...

  11. Irregular wavelet frames on L2(Rn)

    Institute of Scientific and Technical Information of China (English)

    YANG Deyun; ZHOU Xingwei

    2005-01-01

    In this paper, we present the conditions on dilation parameter {sj }j that ensure a discrete irregular wavelet system {Snj/2ψ(sj·-bk)}j∈(Z),k∈(Z)n to be a frame on L2(Rn),and for the wavelet frame we consider the perturbations of translation parameter b and frame function ψ respectively.

  12. Locating irregularly shaped clusters of infection intensity

    DEFF Research Database (Denmark)

    Yiannakoulias, Niko; Wilson, Shona; Kariuki, H. Curtis

    2010-01-01

    Patterns of disease may take on irregular geographic shapes, especially when features of the physical environment influence risk. Identifying these patterns can be important for planning, and also identifying new environmental or social factors associated with high or low risk of illness. Until...

  13. Irregularly Shaped Space-Filling Truncated Octahedra

    Science.gov (United States)

    Hanson, John Robert

    2008-01-01

    For any parent tetrahedron ABCD, centroids of selected sub-tetrahedra form the vertices of an irregularly shaped space-filling truncated octahedron. To reflect these properties, such a figure will be called an ISTO. Each edge of the ISTO is parallel to and one-eighth the length of one of the edges of tetrahedron ABCD and the volume of the ISTO is…

  14. Generalisation of Regular and Irregular Morphological Patterns.

    Science.gov (United States)

    Prasada, Sandeep; and Pinker, Steven

    1993-01-01

    When it comes to explaining English verbs' patterns of regular and irregular generalization, single-network theories have difficulty with the former, rule-only theories with the latter process. Linguistic and psycholinguistic evidence, based on observation during experiments and simulations in morphological pattern generation, independently call…

  15. Stochastic analysis model for vehicle-track coupled systems subject to earthquakes and track random irregularities

    Science.gov (United States)

    Xu, Lei; Zhai, Wanming

    2017-10-01

    This paper devotes to develop a computational model for stochastic analysis and reliability assessment of vehicle-track systems subject to earthquakes and track random irregularities. In this model, the earthquake is expressed as non-stationary random process simulated by spectral representation and random function, and the track random irregularities with ergodic properties on amplitudes, wavelengths and probabilities are characterized by a track irregularity probabilistic model, and then the number theoretical method (NTM) is applied to effectively select representative samples of earthquakes and track random irregularities. Furthermore, a vehicle-track coupled model is presented to obtain the dynamic responses of vehicle-track systems due to the earthquakes and track random irregularities at time-domain, and the probability density evolution method (PDEM) is introduced to describe the evolutionary process of probability from excitation input to response output by assuming the vehicle-track system as a probabilistic conservative system, which lays the foundation on reliability assessment of vehicle-track systems. The effectiveness of the proposed model is validated by comparing to the results of Monte-Carlo method from statistical viewpoint. As an illustrative example, the random vibrations of a high-speed railway vehicle running on the track slabs excited by lateral seismic waves and track random irregularities are analyzed, from which some significant conclusions can be drawn, e.g., track irregularities will additionally promote the dynamic influence of earthquakes especially on maximum values and dispersion degree of responses; the characteristic frequencies or frequency ranges respectively governed by earthquakes and track random irregularities are greatly different, moreover, the lateral seismic waves will dominate or even change the characteristic frequencies of system responses of some lateral dynamic indices at low frequency.

  16. Prostate-specific Antigen (PSA Density and Free to Total PSA Ratio in Diagnosing Prostate Cancer with Prostate-Specific Anti¬gen Levels of 4.0 ng/ml or Less

    Directory of Open Access Journals (Sweden)

    Xin LIU

    2015-11-01

    Full Text Available Background: We aimed to value the usefulness of free to total prostate-specific antigen and Prostate-specific antigen (PSA density for prostate cancer in the patients with PSA levels of 4.0 ng/ml or less.Methods: A total of 343 subjects with PSA levels of 4.0 ng/ml or less were biopsied. All patients were divided into four groups according to the PSA levels: 0 to 1.0 ng/ml, 1.1 to 2.0 ng/ml, 2.1 to 3.0 ng/ml, and 3.1 to 4.0 ng/ml. The reliability of cancer detection in relation to the f/t PSA ratio and PSAD were estimated.Results: Overall, 65 people were diagnosed with prostate cancer. The detection rate was 16.28%、17.17%, 21.82%, 25.00% in subjects with PSA levels of 0 to 1.0 ng/ml, 1.1 to 2.0 ng/ml, 2.1 to 3.0 ng/ml, and 3.1 to 4.0 ng/ml, respectively. The f/t PSA ratio was significantly lower in patients with prostate cancer and PSA levels of 2.1 to 4.0 ng/ml (P<0.05. The PSAD had no statistical significance between the two groups.Conclusions: Routine prostate biopsy should be undertaken if the f/t PSA ratio less than 15% with /without abnormal DRE/TRUS findings. Keywords: Biopsy, Prostate cancer, Prostate-specific antigen, PSA ratio, PSAD 

  17. ON THE STAR FORMATION LAW FOR SPIRAL AND IRREGULAR GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Elmegreen, Bruce G., E-mail: bge@us.ibm.com [IBM Research Division, T.J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY 10598 (United States)

    2015-12-01

    A dynamical model for star formation on a galactic scale is proposed in which the interstellar medium is constantly condensing to star-forming clouds on the dynamical time of the average midplane density, and the clouds are constantly being disrupted on the dynamical timescale appropriate for their higher density. In this model, the areal star formation rate scales with the 1.5 power of the total gas column density throughout the main regions of spiral galaxies, and with a steeper power, 2, in the far outer regions and in dwarf irregular galaxies because of the flaring disks. At the same time, there is a molecular star formation law that is linear in the main and outer parts of disks and in dIrrs because the duration of individual structures in the molecular phase is also the dynamical timescale, canceling the additional 0.5 power of surface density. The total gas consumption time scales directly with the midplane dynamical time, quenching star formation in the inner regions if there is no accretion, and sustaining star formation for ∼100 Gyr or more in the outer regions with no qualitative change in gas stability or molecular cloud properties. The ULIRG track follows from high densities in galaxy collisions.

  18. A Radio Propagation Technique for Geolocating Ionospheric Irregularities along Radio Occultation Ray-Paths

    Science.gov (United States)

    Carrano, C. S.; Groves, K. M.; Rino, C. L.; McNeil, W. J.

    2016-12-01

    Radio occultations (RO) with Global Navigation Satellite System (GNSS) signas have been widely used for remote sensing of tropospheric parameters and to provide ionospheric electron density profiles for the purpose of improving terrestrial and space weather forecasts. Radio occultations have also been used to investigate the morphology of irregularities that cause radio wave scintillation. Spaced-based monitoring of ionospheric irregularities is advantageous because it can be performed continuously and globally, including over ocean regions not easily monitored with ground-based instruments. Nevertheless, the radio propagation path of an occultation through the ionosphere can be very long (up to several thousand km), such that it can be challenging to infer the geographic location and extent of the irregularities from the scintillations they produce. Unlike RO retrievals of slant TEC which are dominated by the contribution near the tangent point, scintillations can be generated by irregularities distributed anywhere along the propagation path between transmitting and receiving satellites. In this paper, we propose a new technique for characterizing and geolocating ionospheric irregularities using radio occultation observations of amplitude scintillation. The approach taken is to solve an inverse problem for the propagation of radio waves through a phase changing screen. Referred to as Irregularity Parameter Estimation (Carrano and Rino, Radio Sci, 2016), this inverse technique estimates the irregularity turbulence strength, spectral index, and Fresnel frequency from measurements of amplitude scintillation. A new model for the effective velocity at which the radio occultation ray-path scans through the irregularity region is used to map the estimated Fresnel frequency to Fresnel spatial scale, which yields the distance from the receiver to the irregularities. Additional geophysical factors such as apex altitude and background electron density along the ray-path can

  19. Fitting Irregular Shape Figures into Irregular Shape Areas for the Nesting Problem in the Leather Industry

    Directory of Open Access Journals (Sweden)

    Guevara-Palma Luis

    2015-01-01

    Full Text Available The nesting problem of irregular shapes within irregular areas has been studied from several approaches due to their application in different industries. The particular case of cutting leather involves several restrictions that add complexity to this problem, it is necessary to generate products that comply with the quality required by customers This paper presents a methodology for the accommodation of irregular shapes in an irregular area (leather considering the constraints set by the footwear industry, and the results of this methodology when applied by a computer system. The scope of the system is to develop a working prototype that operates under the guidelines of a commercial production line of a sponsor company. Preliminary results got a reduction of 70% of processing time and improvement of 5% to 7% of the area usage when compared with manual accommodation.

  20. Practical Aspects of the Spectral Analysis of Irregularly Sampled Data With Time-Series Models

    NARCIS (Netherlands)

    Broersen, P.M.T.

    2009-01-01

    Several algorithms for the spectral analysis of irregularly sampled random processes can estimate the spectral density for a low frequency range. A new time-series method extended that frequency range with a factor of thousand or more. The new algorithm has two requirements to give useful results. F

  1. How Is COPD Diagnosed?

    Science.gov (United States)

    ... page from the NHLBI on Twitter. How Is COPD Diagnosed? Your doctor will diagnose COPD based on ... Rate This Content: NEXT >> Featured Video What is COPD? 05/22/2014 Describes how COPD, or chronic ...

  2. How Is Atherosclerosis Diagnosed?

    Science.gov (United States)

    ... page from the NHLBI on Twitter. How Is Atherosclerosis Diagnosed? Your doctor will diagnose atherosclerosis based on ... Rate This Content: NEXT >> Featured Video What is atherosclerosis? 05/22/2014 Describes how the build-up ...

  3. How Are Thalassemias Diagnosed?

    Science.gov (United States)

    ... page from the NHLBI on Twitter. How Are Thalassemias Diagnosed? Doctors diagnose thalassemias using blood tests , including a complete blood count ( ... in a sample of blood. People who have thalassemias have fewer healthy red blood cells and less ...

  4. How Is Sarcoidosis Diagnosed?

    Science.gov (United States)

    ... page from the NHLBI on Twitter. How Is Sarcoidosis Diagnosed? Your doctor will diagnose sarcoidosis based on ... Content: NEXT >> Featured Video Living With and Managing Sarcoidosis 05/18/2011 This video—presented by the ...

  5. Diagnosing Tic Disorders

    Science.gov (United States)

    ... Other Websites Information For... Media Policy Makers Diagnosing Tic Disorders Language: English Español (Spanish) Recommend on Facebook ... or postviral encephalitis). Persistent (Chronic) Motor or Vocal Tic Disorder For a person to be diagnosed with ...

  6. How Is Vasculitis Diagnosed?

    Science.gov (United States)

    ... page from the NHLBI on Twitter. How Is Vasculitis Diagnosed? Your doctor will diagnose vasculitis based on your signs and symptoms, your medical ... results. Specialists Involved Depending on the type of vasculitis you have and the organs affected, your doctor ...

  7. Magnetic fields in Local Group dwarf irregulars

    CERN Document Server

    Chyzy, Krzysztof T; Beck, Rainer; Bomans, Dominik J

    2011-01-01

    We clarify whether strong magnetic fields can be effectively generated in typically low-mass dwarf galaxies and what is the role of dwarf galaxies in the magnetization of the Universe. We performed a search for radio emission and magnetic fields in an unbiased sample of 12 Local Group (LG) irregular and dwarf irregular galaxies with the 100m Effelsberg telescope at 2.64 and 4.85GHz. Magnetic fields in LG dwarfs are three times weaker than in the normal spirals (6muG) are observed only in dwarfs of extreme characteristics while typical LG dwarfs are not suitable objects for efficient supply of magnetic fields to the intergalactic medium.

  8. Generating Performance Models for Irregular Applications

    Energy Technology Data Exchange (ETDEWEB)

    Friese, Ryan D.; Tallent, Nathan R.; Vishnu, Abhinav; Kerbyson, Darren J.; Hoisie, Adolfy

    2017-05-30

    Many applications have irregular behavior --- non-uniform input data, input-dependent solvers, irregular memory accesses, unbiased branches --- that cannot be captured using today's automated performance modeling techniques. We describe new hierarchical critical path analyses for the \\Palm model generation tool. To create a model's structure, we capture tasks along representative MPI critical paths. We create a histogram of critical tasks with parameterized task arguments and instance counts. To model each task, we identify hot instruction-level sub-paths and model each sub-path based on data flow, instruction scheduling, and data locality. We describe application models that generate accurate predictions for strong scaling when varying CPU speed, cache speed, memory speed, and architecture. We present results for the Sweep3D neutron transport benchmark; Page Rank on multiple graphs; Support Vector Machine with pruning; and PFLOTRAN's reactive flow/transport solver with domain-induced load imbalance.

  9. A Hybrid Heuristics for Irregular Flight Recovery

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiu-li; ZHU Jin-fu; GAO Qiang

    2010-01-01

    Adverse weather conditions, congestion at airports, and mechanical failures often disrupt regular flight schedules. The irregular flight recovery problem aims to recover these schedules through reassignments of flights and cancellations. In this article, we develop the classic resource assignment model for the irregular flight recovery problem, and a new hybrid heuristic procedure based on greedy random adaptive search procedure (GRASP) and simulated annealing algorithm is presented to solve this problem. As compared with the original GRASP method, the proposed algorithm demonstrates quite a high global optimization capability. Computational experiments on large-scale problems show that the proposed procedure is able to generate feasible revised flight schedules of good quality in less than five seconds.

  10. Parallel Programming Strategies for Irregular Adaptive Applications

    Science.gov (United States)

    Biswas, Rupak; Biegel, Bryan (Technical Monitor)

    2001-01-01

    Achieving scalable performance for dynamic irregular applications is eminently challenging. Traditional message-passing approaches have been making steady progress towards this goal; however, they suffer from complex implementation requirements. The use of a global address space greatly simplifies the programming task, but can degrade the performance for such computations. In this work, we examine two typical irregular adaptive applications, Dynamic Remeshing and N-Body, under competing programming methodologies and across various parallel architectures. The Dynamic Remeshing application simulates flow over an airfoil, and refines localized regions of the underlying unstructured mesh. The N-Body experiment models two neighboring Plummer galaxies that are about to undergo a merger. Both problems demonstrate dramatic changes in processor workloads and interprocessor communication with time; thus, dynamic load balancing is a required component.

  11. Conditions for Adopting an Irregular Defense Strategy

    Science.gov (United States)

    2014-06-01

    however, believed that the irregular campaign needed to be conducted in the rural and urban area simultaneously.38 Fidel Castro and Che Guevara...shape; they were conscripts and unwilling to fight. The Batista regime was already unpopular when Castro and Guevara came along, and here is where the...scale publicity effort driven by Castro who had always shown a great capability to turn even unsuccessful military actions into propaganda triumphs

  12. Synchronizing data from irregularly sampled sensors

    Energy Technology Data Exchange (ETDEWEB)

    Uluyol, Onder

    2017-07-11

    A system and method include receiving a set of sampled measurements for each of multiple sensors, wherein the sampled measurements are at irregular intervals or different rates, re-sampling the sampled measurements of each of the multiple sensors at a higher rate than one of the sensor's set of sampled measurements, and synchronizing the sampled measurements of each of the multiple sensors.

  13. Gelatinous plankton: irregularities rule the world (sometimes)

    OpenAIRE

    Boero, F.; Bouillon, J; GRAVILI C.; Miglietta, M. P.; Parsons, T. R.; Piraino, S.

    2008-01-01

    In spite of being one of the most relevant components of the biosphere, the plankton-benthos network is still poorly studied as such. This is partly due to the irregular occurrence of driving phenomena such as gelatinous plankton pulses in this realm. Gelatinous plankters rely on their life cycles and histories to exploit temporarily abundant resources with an undeniable, but often overlooked, impact on marine food webs. Dramatic increases of gelatinous filter-feeders and/or carnivores (both ...

  14. Formation of irregular rings in silica aerogel structure during the sintering process

    Directory of Open Access Journals (Sweden)

    Hinić Ivana I.

    2003-01-01

    Full Text Available Samples of low-density, highly disordered silica aerogel with initial bulk density of 0.16 g/cm3, were sintered isothermally in different time intervals at 1000ºC. Structural changes during the sintering process have been investigated by Raman spectroscopy. Defect modes of irregular three and four membered rings were observed in the Raman spectra of sintered samples.

  15. On the Star Formation Law for Spiral and Irregular Galaxies

    CERN Document Server

    Elmegreen, Bruce G

    2015-01-01

    A dynamical model for star formation on a galactic scale is proposed in which the interstellar medium is constantly condensing to star-forming clouds on the dynamical time of the average midplane density, and the clouds are constantly being disrupted on the dynamical time scale appropriate for their higher density. In this model, the areal star formation rate scales with the 1.5 power of the total gas column density throughout the main regions of spiral galaxies, and with a steeper power, 2, in the far outer regions and in dwarf irregular galaxies because of the flaring disks. At the same time, there is a molecular star formation law that is linear in the main and outer parts of disks and in dIrrs because the duration of individual structures in the molecular phase is also the dynamical time scale, canceling the additional 0.5 power of surface density. The total gas consumption time scales directly with the midplane dynamical time, quenching star formation in the inner regions if there is no accretion, and su...

  16. A Star Formation Law for Dwarf Irregular Galaxies

    CERN Document Server

    Elmegreen, Bruce G

    2015-01-01

    The radial profiles of gas, stars, and far ultraviolet radiation in 20 dwarf Irregular galaxies are converted to stability parameters and scale heights for a test of the importance of two-dimensional (2D) instabilities in promoting star formation. A detailed model of this instability involving gaseous and stellar fluids with self-consistent thicknesses and energy dissipation on a perturbation crossing time give the unstable growth rates. We find that all locations are effectively stable to 2D perturbations, mostly because the disks are thick. We then consider the average volume densities in the midplanes, evaluated from the observed HI surface densities and calculated scale heights. The radial profiles of the star formation rates are equal to about 1% of the HI surface densities divided by the free fall times at the average midplane densities. This 1% resembles the efficiency per unit free fall time commonly found in other cases. There is a further variation of this efficiency with radius in all of our galaxi...

  17. When You Visit Your Doctor: Irregular Menstrual Periods

    Science.gov (United States)

    ... delivered to your inbox ! When You Visit Your Doctor - Irregular Menstrual Periods Irregular Menstrual Periods Updated: January ... Have you ever had difficulty getting pregnant? Your Doctor Might Examine the Following Body Structures or Functions: ...

  18. Total irregular labeling of butterfly network on level two

    Science.gov (United States)

    Nurdin

    2017-08-01

    Previous results related to the concepts of the total irregular labeling of a graph indicate that the butterfly network was one of some graphs which have not been specified in term of the total irregularity strengths. This paper aimed to determine the total vertex irregularity strength, the total edge irregularity strength, and the total irregularity strength of butterfly network on level 2. The assessment of three parameters of butterfly network was conducted by determining the lower bound and the upper bound. The lower bound was analyzed based on the characteristics of the graph and other proponent theorems, while upper bound was analyzed by constructing a function. In this paper we determine that the total vertex irregularity strength, the total edge irregularity strength, and the total irregularity strength of butterfly network are 4, 6, and 6, respectively.

  19. Serum Non-high-density lipoprotein cholesterol concentration and risk of death from cardiovascular diseases among U.S. adults with diagnosed diabetes: the Third National Health and Nutrition Examination Survey linked mortality study

    Directory of Open Access Journals (Sweden)

    Balluz Lina S

    2011-05-01

    Full Text Available Abstract Background Non-high-density lipoprotein cholesterol (non-HDL-C measures all atherogenic apolipoprotein B-containing lipoproteins and predicts risk of cardiovascular diseases (CVD. The association of non-HDL-C with risk of death from CVD in diabetes is not well understood. This study assessed the hypothesis that, among adults with diabetes, non-HDL-C may be related to the risk of death from CVD. Methods We analyzed data from 1,122 adults aged 20 years and older with diagnosed diabetes who participated in the Third National Health and Nutrition Examination Survey linked mortality study (299 deaths from CVD according to underlying cause of death; median follow-up length, 12.4 years. Results Compared to participants with serum non-HDL-C concentrations of 35 to 129 mg/dL, those with higher serum levels had a higher risk of death from total CVD: the RRs were 1.34 (95% CI: 0.75-2.39 and 2.25 (95% CI: 1.30-3.91 for non-HDL-C concentrations of 130-189 mg/dL and 190-403 mg/dL, respectively (P = 0.003 for linear trend after adjustment for demographic characteristics and selected risk factors. In subgroup analyses, significant linear trends were identified for the risk of death from ischemic heart disease: the RRs were 1.59 (95% CI: 0.76-3.32 and 2.50 (95% CI: 1.28-4.89 (P = 0.006 for linear trend, and stroke: the RRs were 3.37 (95% CI: 0.95-11.90 and 5.81 (95% CI: 1.96-17.25 (P = 0.001 for linear trend. Conclusions In diabetics, higher serum non-HDL-C concentrations were significantly associated with increased risk of death from CVD. Our prospective data support the notion that reducing serum non-HDL-C concentrations may be beneficial in the prevention of excess death from CVD among affected adults.

  20. Photometric survey of the irregular satellites

    Science.gov (United States)

    Grav, Tommy; Holman, Matthew J.; Gladman, Brett J.; Aksnes, Kaare

    2003-11-01

    We present BVRI colors of 13 jovian and 8 saturnian irregular satellites obtained with the 2.56 m Nordic Optical Telescope on La Palma, the 6.5 m Magellan Baade Telescope on La Campanas, and the 6.5 m MMT on Mt. Hopkins. The observations were performed from December 2001 to March 2002. The colors of the irregular satellites vary from grey to light red. We have arbitrarily divided the known irregular satellites into two classes based on their colors. One, the grey color class, has similar colors to the C-type asteroids, and the other, the light red color class, has colors similar to P/D-type asteroids. We also find at least one object, the jovian irregular J XXIII Kalyke, that has colors similar to the red colored Centaurs/TNOs, although its classification is insecure. We find that there is a correlation between the physical properties and dynamical properties of the irregular satellites. Most of the dynamical clusters have homogeneous colors, which points to single homogeneous progenitors being cratered or fragmented as the source of each individual cluster. The heterogeneously colored clusters are most easily explained by assuming that there are several dynamical clusters in the area, rather than just one, or that the parent body was a differentiated, heterogeneous body. By analyzing simple cratering/fragmentation scenarios, we show that the heterogeneous colored S IX Phoebe cluster, is most likely two different clusters, a grey colored cluster centered on S IX Phoebe and a light red colored cluster centered on S/2000 S 1. To which of these two clusters the remaining saturnian irregulars with inclinations close to 174° belong is not clear from our analysis, but determination of their colors should help constrain this. We also show through analysis of possible fragmentation and dispersion of the six known uranian irregulars that they most likely make up two clusters, one centered on U XVI Caliban and another centered on U XVII Sycorax. We further show that

  1. Vertex Operators for Irregular Conformal Blocks: Supersymmetric Case

    CERN Document Server

    Polyakov, Dimitri

    2016-01-01

    We construct supersymmetric irregular vertex operators of arbitrary rank, appearing in the colliding limit of primary fields. We find that the structure of the supersymmetric irregular vertices differs significantly from the bosonic case: upon supersymmetrization, the irregular operators are no longer the eigenstates of positive Virasoro and $W_N$ generators but block-diagonalize them. We relate the block-diagonal structure of the irregular vertices to contributions of the Ramond sector to the colliding limit.

  2. Weighted statistical parameters for irregularly sampled time series

    CERN Document Server

    Rimoldini, Lorenzo

    2014-01-01

    Unevenly spaced time series are common in astronomy because of the day-night cycle, weather conditions, dependence on the source position in the sky, allocated telescope time, corrupt measurements, for example, or be inherent to the scanning law of satellites like Hipparcos and the forthcoming Gaia. This paper aims at improving the accuracy of common statistical parameters for the characterization of irregularly sampled signals. The uneven representation of time series, often including clumps of measurements and gaps with no data, can severely disrupt the values of estimators. A weighting scheme adapting to the sampling density and noise level of the signal is formulated. Its application to time series from the Hipparcos periodic catalogue led to significant improvements in the overall accuracy and precision of the estimators with respect to the unweighted counterparts and those weighted by inverse-squared uncertainties. Automated classification procedures employing statistical parameters weighted by the sugg...

  3. Combined radar observations of equatorial electrojet irregularities at Jicamarca

    Directory of Open Access Journals (Sweden)

    D. L. Hysell

    2007-03-01

    Full Text Available Daytime equatorial electrojet plasma irregularities were investigated using five distinct radar diagnostics at Jicamarca including range-time-intensity (RTI mapping, Faraday rotation, radar imaging, oblique scattering, and multiple-frequency scattering using the new AMISR prototype UHF radar. Data suggest the existence of plasma density striations separated by 3–5 km and propagating slowly downward. The striations may be caused by neutral atmospheric turbulence, and a possible scenario for their formation is discussed. The Doppler shifts of type 1 echoes observed at VHF and UHF frequencies are compared and interpreted in light of a model of Farley Buneman waves based on kinetic ions and fluid electrons with thermal effects included. Finally, the up-down and east-west asymmetries evident in the radar observations are described and quantified.

  4. Manufacturing of Cast Metal Foams with Irregular Cell Structure

    Directory of Open Access Journals (Sweden)

    Kroupová I.

    2015-06-01

    Full Text Available Metallic foams are materials of which the research is still on-going, with the broad applicability in many different areas (e.g. automotive industry, building industry, medicine, etc.. These metallic materials have specific properties, such as large rigidity at low density, high thermal conductivity, capability to absorb energy, etc. The work is focused on the preparation of these materials using conventional casting technology (infiltration method, which ensures rapid and economically feasible method for production of shaped components. In the experimental part we studied conditions of casting of metallic foams with open pores and irregular cell structure made of ferrous and nonferrous alloys by use of various types of filler material (precursors.

  5. Hitchin Equation, Irregular Singularity, and $N=2$ Asymptotical Free Theories

    CERN Document Server

    Nanopoulos, Dimitri

    2010-01-01

    In this paper, we study irregular singular solution to Hitchin's equation and use it to describe four dimensional $N=2$ asymptotically free gauge theories. For $SU(2)$ $A$ type quiver, two kinds of irregular singularities besides one regular singularity are needed for the solution of Hitchin's equation; We then classify irregular singularities needed for the general $SU(N)$ $A$ type quiver.

  6. On irregularity strength of disjoint union of friendship graphs

    Directory of Open Access Journals (Sweden)

    Ali Ahmad

    2013-11-01

    Full Text Available We investigate the vertex total and edge total modication of the well-known irregularity strength of graphs. We have determined the exact values of the total vertex irregularity strength and the total edge irregularity strength of a disjoint union of friendship graphs.

  7. 16 CFR 501.6 - Cellulose sponges, irregular dimensions.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Cellulose sponges, irregular dimensions. 501... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.6 Cellulose sponges, irregular dimensions. Variety packages of cellulose sponges of irregular dimensions, are exempted from the requirements of § 500.25 of...

  8. Astrometric positions for 18 irregular satellites of giant planets from 23 years of observations

    CERN Document Server

    Gomes-Júnior, A R; Vieira-Martins, R; Arlot, J -E; Camargo, J I B; Braga-Ribas, F; Neto, D N da Silva; Andrei, A H; Dias-Oliveira, A; Morgado, B E; Benedetti-Rossi, G; Duchemin, Y; Desmars, J; Lainey, V; Thuillot, W

    2015-01-01

    The irregular satellites of the giant planets are believed to have been captured during the evolution of the solar system. Knowing their physical parameters, such as size, density, and albedo is important for constraining where they came from and how they were captured. The best way to obtain these parameters are observations in situ by spacecrafts or from stellar occultations by the objects. Both techniques demand that the orbits are well known. We aimed to obtain good astrometric positions of irregular satellites to improve their orbits and ephemeris. We identified and reduced observations of several irregular satellites from three databases containing more than 8000 images obtained between 1992 and 2014 at three sites (Observat\\'orio do Pico dos Dias, Observatoire de Haute-Provence, and European Southern Observatory - La Silla). We used the software PRAIA (Platform for Reduction of Astronomical Images Automatically) to make the astrometric reduction of the CCD frames. The UCAC4 catalog represented the Inte...

  9. A new angle for probing field-aligned irregularities with the Murchison Widefield Array

    CERN Document Server

    Loi, Shyeh Tjing; Cairns, Iver H; Trott, Cathryn M; Hurley-Walker, Natasha; Feng, Lu; Hancock, Paul J; Kaplan, David L

    2016-01-01

    Electron density irregularities in the ionosphere are known to be magnetically anisotropic, preferentially elongated along the lines of force. While many studies of their morphology have been undertaken by topside sounding and whistler measurements, it is only recently that detailed regional-scale reconstructions have become possible, enabled by the advent of widefield radio telescopes. Here we present a new approach for visualising and studying field-aligned irregularities (FAIs), which involves transforming interferometric measurements of TEC gradients onto a magnetic shell tangent plane. This removes the perspective distortion associated with the oblique viewing angle of the irregularities from the ground, facilitating the decomposition of dynamics along and across magnetic field lines. We apply this transformation to the dataset of Loi et al. [2015a], obtained on 15 October 2013 by the Murchison Widefield Array (MWA) radio telescope and displaying prominent FAIs. We study these FAIs in the new reference f...

  10. A novel model for determining the amplitude-wavelength limits of track irregularities accompanied by a reliability assessment in railway vehicle-track dynamics

    Science.gov (United States)

    Xu, Lei; Zhai, Wanming

    2017-03-01

    The loads on a vehicle and the vibrations transmitted to track infrastructures due to the operation of rolling stocks are mainly determined by the irregularities of the track profile. Hence, it is rather important to ascertain the limits of track irregularities, including amplitudes and wavelengths, to guarantee the dynamic performance of running vehicles and guiding tracks. Furthermore, the operation and management levels as well as irregularity status for different railways are highly dissimilar. Therefore, it is a necessary to conduct a reliability assessment for a specific railway line. In the present work, a large amount of measured track irregularities are concentrated as a group form of the track irregularity power spectrum density. A track irregularity inversion model is presented to obtain realistic representations of track profile deformations with information regarding amplitudes, wavelengths and probabilities. Then, the methodologies for determining the limits of track irregularities and achieving a reliability assessment are presented by introducing the probability density evolution method and development of a Wavelet-Wigner-Hough method. Using the vehicle-track interaction model, numerical studies for confirming the limits of track irregularities and evaluating the reliability of the dynamic performance of the vehicle can be conducted to provide valuable suggestions. This paper offers new possibilities for studying the limit amplitudes, characteristic wavelengths of track irregularities as well as corresponding reliabilities when a railway vehicle runs under different track geometric conditions.

  11. Scintillation and irregularities from the nightside part of a Sun-aligned polar cap arc

    Science.gov (United States)

    Meeren, Christer; Oksavik, Kjellmar; Lorentzen, Dag A.; Paxton, Larry J.; Clausen, Lasse B. N.

    2016-06-01

    In this paper we study the presence of irregularities and scintillation in relation to the nightside part of a long-lived, Sun-aligned transpolar arc on 15 January 2015. The arc was observed in DMSP UV and particle data and lasted at least 3 h between 1700 and 2000 UT. The arc was more intense than the main oval during this time. From all-sky imagers on Svalbard we were able to study the evolution of the arc, which drifted slowly westward toward the dusk cell. The intensity of the arc as observed from ground was 10-17 kR in 557.7 nm and 2-3.5 kR in 630.0 nm, i.e., significant emissions in both green and red emission lines. We have used high-resolution raw data from global navigation satellite systems (GNSS) receivers and backscatter from Super Dual Auroral Radar Network (SuperDARN) radars to study irregularities and scintillation in relation to the polar cap arc. Even though the literature has suggested that polar cap arcs are potential sources for irregularities, our results indicate only very weak irregularities. This may be due to the background density in the northward IMF polar cap being too low for significant irregularities to be created.

  12. Testing Of Choiced Ceramics Cutting Tools At Irregular Interrupted Cut

    Science.gov (United States)

    Kyncl, Ladislav; Malotová, Šárka; Nováček, Pavel; Nicielnik, Henryk; Šoková, Dagmar; Hemžský, Pavel; Pitela, David; Holubjak, Jozef

    2015-12-01

    This article discusses the test of removable ceramic cutting inserts during machining irregular interrupted cut. Tests were performed on a lathe, with the preparation which simulated us the interrupted cut. By changing the number of plates mounted in a preparation it simulate us a regular or irregular interrupted cut. When with four plates it was regular interrupted cut, the remaining three variants were already irregular cut. It was examined whether it will have the irregular interrupted cutting effect on the insert and possibly how it will change life of inserts during irregular interrupted cut (variable delay between shocks).

  13. Irregular satellite capture during planetary resonance passage

    Science.gov (United States)

    Ćuk, Matija; Gladman, Brett J.

    2006-08-01

    The passage of Jupiter and Saturn through mutual 1:2 mean-motion resonance has recently been put forward as explanation for their relatively high eccentricities [Tsiganis, K., Gomes, R., Morbidelli, A., Levison, H.F., 2005. Nature 435, 459-461] and the origin of Jupiter's Trojans [Morbidelli, A., Levison, H.F., Tsiganis, K., Gomes, R., 2005. Nature 435, 462-465]. Additional constraints on this event based on other small-body populations would be highly desirable. Since some outer satellite orbits are known to be strongly affected by the near-resonance of Jupiter and Saturn ("the Great Inequality"; Ćuk, M., Burns, J.A., 2004b. Astron. J. 128, 2518-2541), the irregular satellites are natural candidates for such a connection. In order to explore this scenario, we have integrated 9200 test particles around both Jupiter and Saturn while they went through a resonance-crossing event similar to that described by Tsiganis et al. [Tsiganis, K., Gomes, R., Morbidelli, A., Levison, H.F., 2005. Nature 435, 459-461]. The test particles were positioned on a grid in semimajor axes and inclinations, while their initial pericenters were put at just 0.01 AU from their parent planets. The goal of the experiment was to find out if short-lived bodies, spiraling into the planet due to gas drag (or alternatively on orbits crossing those of the regular satellites), could have their pericenters raised by the resonant perturbations. We found that about 3% of the particles had their pericenters raised above 0.03 AU (i.e. beyond Iapetus) at Saturn, but the same happened for only 0.1% of the particles at Jupiter. The distribution of surviving particles at Saturn has strong similarities to that of the known irregular satellites. If saturnian irregular satellites had their origin during the 1:2 resonance crossing, they present an excellent probe into the early Solar System's evolution. We also explore the applicability of this mechanism for Uranus, and find that only some of the uranian

  14. Subsonic Mechanical Alignment of Irregular Grains

    CERN Document Server

    Lazarian, Alex

    2007-01-01

    We show that grains can be efficiently aligned by interacting with a subsonic gaseous flow. The alignment arises from grains having irregularities that scatter atoms with different efficiency in the right and left directions. The grains tend to align with long axes perpendicular to magnetic field, which corresponds to Davis-Greenstein predictions, but does not involve magnetic field. For rather conservative factors characterizing the grain helicity and scattering efficiency of impinging atoms, the alignment of helical grains is much more efficient than the Gold-type alignment processes.

  15. Legal aspects of the EU policy on irregular immigration

    Directory of Open Access Journals (Sweden)

    Voinikov Vadim

    2015-12-01

    Full Text Available This article addresses the issues pertaining to the adoption and development of legislation on irregular migration in the context of uncontrolled growth in the number of immigrants from North Africa and the Middle East to the EU. The article attempts at studying the EU legislation on irregular migration, classifying it, and analysing the prospects of EU migration legislation in the light of an increase in irregular immigration into the EU. The author systematises, classifies the current EU legislation on irregular immigration, and analyses the conditions, in which this legislation was developed. Using the legislation analysis method, the author proposes the following system of EU legislation on irregular immigration: rules preventing assistance to irregular immigration, rules preventing employment of irregular immigrants, rules on the return of irregular migrants and readmission, rules on border control, and rules on collaboration with third countries. The author pays special attention to analysing the current state of irregular immigration to the EU, which was dubbed the ‘greatest migration crisis in Europe’. The conclusion is that the European Union succeeded in the development of pioneering legislation on irregular immigration, which can serve as the basis for reception by other states. However, changes in the political and economic situation in the EU’s southern borderlands made the current legal mechanisms incapable of withstanding new threats. It necessitates a radical reform of the legislation on irregular immigration.

  16. Investigation of the temperature gradient instability as the source of midlatitude quiet time decameter-scale ionospheric irregularities: 1. Observations

    Science.gov (United States)

    Larquier, S.; Eltrass, A.; Mahmoudian, A.; Ruohoniemi, J. M.; Baker, J. B. H.; Scales, W. A.; Erickson, P. J.; Greenwald, R. A.

    2014-06-01

    Super Dual Auroral Radar Network (SuperDARN) radars regularly observe decameter-scale ionospheric irregularities at midlatitudes during quiet geomagnetic conditions. The mechanism responsible for the growth of such irregularities is still unknown. Previous results based on data from the Wallops SuperDARN HF radar and Incoherent Scatter Radar have suggested that the Temperature Gradient Instability (TGI) could be responsible for only part of the observed irregularities. This conclusion was reached based on the relative orientation of horizontal electron temperature and density gradients. However, the TGI theory requires driving gradients to be perpendicular to perpendicular to the geomagnetic field B. Since midlatitude field lines are approximately 20° off vertical, we have reexamined the original data and computed gradients along the meridional direction perpendicular to B. Distinctions have to be made between the topside and bottomside F region due to the strong influence of vertical gradients. We find that the TGI growth is possible in the topside F region for the duration of the experiment, even before irregularities were observed. We show that the absence of observed irregularities during favorable TGI growth conditions is not a consequence of HF propagation but of higher E region electron irregularity growth. We conclude that the TGI is a valid mechanism to explain the generation of all irregularities observed during the experiment.

  17. Density structures inside the plasmasphere: Cluster observations

    DEFF Research Database (Denmark)

    Darrouzet, F.; Decreau, P.M.E.; De Keyser, J.;

    2004-01-01

    The electron density profiles derived from the EFW and WHISPER instruments on board the four Cluster spacecraft reveal density structures inside the plasmasphere and at its outer boundary, the plasmapause. We have conducted a statistical study to characterize these density structures. We focus...... on the plasmasphere crossing on I I April 2002, during which Cluster observed several density irregularities inside the plasmasphere, as well as a plasmaspheric plume. We derive the density gradient vectors from simultaneous density measurements by the four spacecraft. We also determine the normal velocity...... of the boundaries of the plume and of the irregularities from the time delays between those boundaries in the four individual density profiles, assuming they are planar. These new observations yield novel insights about the occurrence of density irregularities, their geometry and their dynamics. These in...

  18. Statistical detection of systematic election irregularities

    Science.gov (United States)

    Klimek, Peter; Yegorov, Yuri; Hanel, Rudolf; Thurner, Stefan

    2012-01-01

    Democratic societies are built around the principle of free and fair elections, and that each citizen’s vote should count equally. National elections can be regarded as large-scale social experiments, where people are grouped into usually large numbers of electoral districts and vote according to their preferences. The large number of samples implies statistical consequences for the polling results, which can be used to identify election irregularities. Using a suitable data representation, we find that vote distributions of elections with alleged fraud show a kurtosis substantially exceeding the kurtosis of normal elections, depending on the level of data aggregation. As an example, we show that reported irregularities in recent Russian elections are, indeed, well-explained by systematic ballot stuffing. We develop a parametric model quantifying the extent to which fraudulent mechanisms are present. We formulate a parametric test detecting these statistical properties in election results. Remarkably, this technique produces robust outcomes with respect to the resolution of the data and therefore, allows for cross-country comparisons. PMID:23010929

  19. Differential diagnoses to MS

    DEFF Research Database (Denmark)

    Horwitz, Henrik; Friis, Tina; Modvig, Signe;

    2014-01-01

    of 643 patients were included in the study. Apart from ON, the most frequent diagnoses were tumors (n = 15), ischemic or hypertensive neuropathies (n = 13), and retinal or choroid disorders (n = 9). Six patients were diagnosed with neuromyelitis optica. Rarer causes of visual loss were infections (n = 5...

  20. How Is Raynaud's Diagnosed?

    Science.gov (United States)

    ... diagnose primary Raynaud's (Raynaud's disease) or secondary Raynaud's (Raynaud's phenomenon) based on your medical history, a physical exam, and test results. Specialists Involved Primary care doctors and internists often diagnose and treat Raynaud's. If you have the disorder, you also may ...

  1. Diagnosing Sleep Disorders

    Science.gov (United States)

    ... of this page please turn JavaScript on. Feature: Sleep Disorders Diagnosing Sleep Disorders Past Issues / Summer 2015 Table of Contents Depending ... several possible tests when trying to diagnose a sleep disorder: Sleep history and sleep log If you believe ...

  2. How Is Wilson Disease Diagnosed?

    Science.gov (United States)

    ... insomnia Psychiatric: Depression; neuroses; personality changes; psychosis Other symptoms: Renal abnormalities: amino-aciduria and nephrolithiasis; skeletal abnormalities: premature osteoporosis and arthritis; cardiomyopathy, dysrhythmias; pancreatitis; hypoparathyroidism; menstrual irregularities: ...

  3. IRREGULAR WAVELET FRAMES AND GABOR FRAMES

    Institute of Scientific and Technical Information of China (English)

    Ole Christensen; Sergio Favier; Felipe Zó

    2001-01-01

    Given g ∈ L2 (R), we consider irregular wavelet systems of theform {λ g(λj x-kb) }j z. kz, where λj >0 and b>0. Sufficient conditions for the wavelet system to constitute a frame for L2(R) are given. For a class of functions g ∈ L 2 (R) we prove that certain growth conditions on {λj} will lead to frames, and that some other types of sequences exclude the frame property. We also give a sufficient condition for a Gabor system {exib(j,x)g(x-λh)}jzn,kz to be a frame.CLC Number:O17 Document ID:AAuthor Resume:Ole Christensen;E-mail: Ole. Christensen@mat. dtu. dk Sergio Favier and Felipe Zó ;e-mails : sfavier@unsl. edu. ar fzo@unsl. edu. ar References:[1]Casaza,P.G. and Christensen,O.,Weyl-Heisenberg Frames for Subspaces of L2(R),Proc.Amer. Math. Soc. ,129(2001),145-154.[2]Casazza,P.G. and Christensen,O. ,Classifying Certain Irregular Gabor Frames,preprint[2]001.[3]Christensen,O. and Lindner,A. ,Lower Bounds for Finite Wavelet and Gabor Systems,Appr. Theory and Appl.,17(2001),17-31.[4]Chui,C.K. and Shi,X. ,Inequalities of Litdewood-Paley Type for Frames and Wavelets,SIAM J. Math. Anal. ,24:1(1993),263-277.[5]Daubechies,I. ,Ten Lectures on Wavelets,SIAM,Philadelphia,1992.[6]Favier,S. and Zalik,R. ,On the Stability of Frames and Riesz Bases,Appl. Comp. Ham.Anal. ,2(1995),160-173.[7]Feichtinger,H.G. and Strohmer,T. ,(Eds.),Gabor Analysis and Algorithms : Theory and Applications,Birkhauser,1998.[8]Heil,C.E. and Walnut,D.F. ,Continuous and Discrete Wavelet Transforms,SIAM Review,31:4(1989),628-666.[9]Sun,W. and Zhou,X. ,Irregular Wavelet Frames,Science in China (Series A),43:2(2000),122-127.Manuscript Received:2001年7月10日Manuscript Revised:2001年7月23日Published:2001年9月1日

  4. A parametric approach to irregular fatigue prediction

    Science.gov (United States)

    Erismann, T. H.

    1972-01-01

    A parametric approach to irregular fatigue protection is presented. The method proposed consists of two parts: empirical determination of certain characteristics of a material by means of a relatively small number of well-defined standard tests, and arithmetical application of the results obtained to arbitrary loading histories. The following groups of parameters are thus taken into account: (1) the variations of the mean stress, (2) the interaction of these variations and the superposed oscillating stresses, (3) the spectrum of the oscillating-stress amplitudes, and (4) the sequence of the oscillating-stress amplitudes. It is pointed out that only experimental verification can throw sufficient light upon possibilities and limitations of this (or any other) prediction method.

  5. Measurement of ionospheric large-scale irregularity

    Institute of Scientific and Technical Information of China (English)

    韩文焌; 郑怡嘉; 张喜镇

    1996-01-01

    Based on the observations of a meter-wave aperture synthesis radio telescope,as the scale length of ionospheric irregularity is greatly larger than the baseline length of interferometer,the phase error induced by the output signal of interferometer due to ionosphere is proportional to the baseline length and accordingly the expressions for extracting the information about ionosphere are derived.By using the ray theory and considering that the antenna is always tracking to the radio source in astronomical observation,the wave motion expression of traveling ionospheric disturbance observed in the total electron content is also derived,which is consistent with that obtained from the conception of thin-phase screen;then the Doppler velocity due to antenna tracking is introduced.Finally the inversion analysis for the horizontal phase velocity of TID from observed data is given.

  6. Evaluating transport in irregular pore networks

    CERN Document Server

    Klimenko, Dimitri A; Klimenko, Alexander Y; 10.1103/PhysRevE.86.011112

    2012-01-01

    A general approach for investigating transport phenomena in porous media is presented. This approach has the capacity to represent various kinds of irregularity in porous media without the need for excessive detail or computational effort. The overall method combines a generalized Effective Medium Approximation (EMA) with a macroscopic continuum model in order to derive a transport equation with explicit analytical expressions for the transport coefficients. The proposed form of the EMA is an anisotropic and heterogeneous extension of Kirkpatrick's EMA [Rev. Mod. Phys. 45, 574 (1973)] which allows the overall model to account for microscopic alterations in connectivity (with the locations of the pores and the orientation and length of the throat) as well as macroscopic variations in transport properties. A comparison to numerical results for randomly generated networks with different properties is given, indicating the potential for this methodology to handle cases that would pose significant difficulties to ...

  7. Irregular activity arises as a natural consequence of synaptic inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Terman, D., E-mail: terman@math.ohio-state.edu [Department of Mathematics, The Ohio State University, Columbus, Ohio 43210 (United States); Rubin, J. E., E-mail: jonrubin@pitt.edu [Department of Mathematics, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Diekman, C. O., E-mail: diekman@njit.edu [Department of Mathematical Sciences, New Jersey Institute of Technology, Newark, New Jersey 07102 (United States)

    2013-12-15

    Irregular neuronal activity is observed in a variety of brain regions and states. This work illustrates a novel mechanism by which irregular activity naturally emerges in two-cell neuronal networks featuring coupling by synaptic inhibition. We introduce a one-dimensional map that captures the irregular activity occurring in our simulations of conductance-based differential equations and mathematically analyze the instability of fixed points corresponding to synchronous and antiphase spiking for this map. We find that the irregular solutions that arise exhibit expansion, contraction, and folding in phase space, as expected in chaotic dynamics. Our analysis shows that these features are produced from the interplay of synaptic inhibition with sodium, potassium, and leak currents in a conductance-based framework and provides precise conditions on parameters that ensure that irregular activity will occur. In particular, the temporal details of spiking dynamics must be present for a model to exhibit this irregularity mechanism and must be considered analytically to capture these effects.

  8. Modelling Of Random Vertical Irregularities Of Railway Tracks

    Directory of Open Access Journals (Sweden)

    Podwórna M.

    2015-08-01

    Full Text Available The study presents state-of-the-art in analytical and numerical modelling of random vertical irregularities of continuously welded ballasted railway tracks. The common model of railway track irregularity vertical profiles is applied, in the form of a stationary and ergodic Gaussian process in space. Random samples of track irregularity vertical profiles are generated with the Monte-Carlo method. Based on the numerical method developed in the study, the minimum and recommended sampling number required in the random analysis of railway bridges and number of frequency increments (harmonic components in track irregularity vertical profiles simulation are determined. The lower and upper limits of wavelengths are determined based on the literature studies. The approach yields track irregularity random samples close to reality. The track irregularity model developed in the study can be used in the dynamic analysis of railway bridge / track structure / highspeed train systems.

  9. How Is Hemophilia Diagnosed?

    Science.gov (United States)

    ... page from the NHLBI on Twitter. How Is Hemophilia Diagnosed? If you or your child appears to ... have bleeding problems. However, some people who have hemophilia have no recent family history of the disease. ...

  10. Decomposing Oriented Graphs into Six Locally Irregular Oriented Graphs

    DEFF Research Database (Denmark)

    Bensmail, Julien; Renault, Gabriel

    2016-01-01

    An undirected graph G is locally irregular if every two of its adjacent vertices have distinct degrees. We say that G is decomposable into k locally irregular graphs if there exists a partition E1∪E2∪⋯∪Ek of the edge set E(G) such that each Ei induces a locally irregular graph. It was recently co...

  11. The Analysis and Creation of Track Irregularities Using TRAKVU

    OpenAIRE

    1998-01-01

    The accuracy of the results from a rail vehicle dynamic model is dependent on the realism of the track input to the model. An important part of the track input is the irregularities that exist on actual track. This study analyzes the irregularities inherent in railroad track geometry data, and provides an analytical method for creating track data with the irregularities for use as the input to a dynamic model. Track data, measured from various classes of track, was ...

  12. Advances in electron dosimetry of irregular fields; Avances en dosimetria de electrones de campos irregulares

    Energy Technology Data Exchange (ETDEWEB)

    Mendez V, J. [Departamento de Radioterapia, Instituto de Enfermedades Neoplasicas, Avenida Angamos Este 2520, Lima 34 (Peru)

    1998-12-31

    In this work it is presented an advance in Electron dosimetry of irregular fields for beams emitted by linear accelerators. At present diverse methods exist which are coming to apply in the Radiotherapy centers. In this work it is proposed a method for irregular fields dosimetry. It will be allow to calculate the dose rate absorbed required for evaluating the time for the treatment of cancer patients. Utilizing the results obtained by the dosimetric system, it has been possible to prove the validity of the method describe for 12 MeV energy and for square field 7.5 x 7.5 cm{sup 2} with percentile error less than 1 % . (Author)

  13. Natural convection inside an irregular porous cavity; Conveccao natural no interior de uma cavidade porosa irregular

    Energy Technology Data Exchange (ETDEWEB)

    Beltran, Jorge I. LLagostera; Trevisan, Osvair Vidal [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia

    1990-12-31

    Natural convection flow induced by heating from below in a irregular porous cavity is investigated numerically. The influence of the modified Rayleigh number and geometric ratios on heat transfer and fluid flow is studied. Global and local Nusselt for Rayleigh numbers covering the range 0 - 1600 and for several geometric ratios. The fluid flow and the temperature field are illustrated by contour maps. (author) 6 refs., 10 figs., 7 tabs.

  14. In situ irregularity identification and scintillation estimation using wavelets and CINDI on C/NOFS

    Science.gov (United States)

    Stoneback, R. A.; Heelis, R. A.; Caton, R. G.; Su, Y.-J.; Groves, K. M.

    2013-07-01

    Wavelets are a time-domain method that is able to extract both time and frequency information from a signal. The Morlet wavelet is used here to characterize the magnitude of ionospheric irregularities using measurements of the total ion density from the Coupled Ion Neutral Dynamics Investigation package onboard the Communications/Navigation Outage Forecasting System spacecraft. The power in ionospheric irregularities at scale sizes less than 128 km is used to generate an irregularity amplitude index. This index is used with a phase screen analysis to form an estimate of scintillation at the satellite location. The temporal information retained in a wavelet analysis also allows for an accurate power spectrum calculation even when used on short segments of data which is useful for real-time processing of irregularity detection onboard a satellite or for analyzing the long data sets produced by a satellite. To validate the process, a comparison of the in situ scintillation estimate and Scintillation Network and Decision Aid measurements of the S4 index is presented.

  15. Observations of E region irregularities generated at auroral latitudes by a high-power radio wave

    Science.gov (United States)

    Djuth, F. T.; Jost, R. J.; Noble, S. T.; Gordon, W. E.; Stubbe, P.

    1985-01-01

    The initial results of a series of observations made with the high-power HF heating facility near Tromso, Norway are reported. During these experiments, attention was focused on the production of artificial geomagnetic field-aligned irregularities (AFAIs) in the auroral E region by HF waves. A mobile 46.9-MHz radar was used to diagnose the formation of AFAIs having spatial scales of 3.2 across geomagnetic field lines. The dynamic characteristics of the AFAIs are discussed within the context of current theoretical work dealing with the natural production of AFAIs in the ionosphere.

  16. Ionospheric irregularities at Antarctic using GPS measurements

    Indian Academy of Sciences (India)

    Sunita Tiwari; Amit Jain; Shivalika Sarkar; Sudhir Jain; A K Gwal

    2012-04-01

    The purpose of this work is to study the behaviour of the ionospheric scintillation at high latitude during geomagnetically quiet and disturbed conditions which is one of the most relevant themes in the space weather studies. Scintillation is a major problem in navigation application using GPS and in satellite communication at high latitudes. Severe amplitude fading and strong scintillation affect the reliability of GPS navigational system and satellite communication. To study the effects of the ionospheric scintillations, GPS receiver installed at Antarctic station Maitri (Geog. 70.76°S; 11.74°E) was used. The data is collected by using GISTM 4004A, NOVATEL’S GPS receiver during March 2008. Studies show that percentage occurrence of phase scintillation is well correlated with geomagnetic activity during the observation period. The result also shows that very intense scintillations can degrade GPS based location determination due to loss of lock of satellites. These findings indicate that the dependence of scintillations and irregularity occurrence on geomagnetic activity is associated with the magnetic local time (MLT). Large number of patches are reported and their activity depends on the magnetic activity index.

  17. Multiresolution Analysis Adapted to Irregularly Spaced Data

    Directory of Open Access Journals (Sweden)

    Anissa Mokraoui

    2009-01-01

    Full Text Available This paper investigates the mathematical background of multiresolution analysis in the specific context where the signal is represented by irregularly sampled data at known locations. The study is related to the construction of nested piecewise polynomial multiresolution spaces represented by their corresponding orthonormal bases. Using simple spline basis orthonormalization procedures involves the construction of a large family of orthonormal spline scaling bases defined on consecutive bounded intervals. However, if no more additional conditions than those coming from multiresolution are imposed on each bounded interval, the orthonormal basis is represented by a set of discontinuous scaling functions. The spline wavelet basis also has the same problem. Moreover, the dimension of the corresponding wavelet basis increases with the spline degree. An appropriate orthonormalization procedure of the basic spline space basis, whatever the degree of the spline, allows us to (i provide continuous scaling and wavelet functions, (ii reduce the number of wavelets to only one, and (iii reduce the complexity of the filter bank. Examples of the multiresolution implementations illustrate that the main important features of the traditional multiresolution are also satisfied.

  18. Irregular Homogeneity Domains in Ternary Intermetallic Systems

    Directory of Open Access Journals (Sweden)

    Jean-Marc Joubert

    2015-12-01

    Full Text Available Ternary intermetallic A–B–C systems sometimes have unexpected behaviors. The present paper examines situations in which there is a tendency to simultaneously form the compounds ABx, ACx and BCx with the same crystal structure. This causes irregular shapes of the phase homogeneity domains and, from a structural point of view, a complete reversal of site occupancies for the B atom when crossing the homogeneity domain. This work reviews previous studies done in the systems Fe–Nb–Zr, Hf–Mo–Re, Hf–Re–W, Mo–Re–Zr, Re–W–Zr, Cr–Mn–Si, Cr–Mo–Re, and Mo–Ni–Re, and involving the topologically close-packed Laves, χ and σ phases. These systems have been studied using ternary isothermal section determination, DFT calculations, site occupancy measurement using joint X-ray, and neutron diffraction Rietveld refinement. Conclusions are drawn concerning this phenomenon. The paper also reports new experimental or calculated data on Co–Cr–Re and Fe–Nb–Zr systems.

  19. Design strategies for irregularly adapting parallel applications

    Energy Technology Data Exchange (ETDEWEB)

    Oliker, Leonid; Biswas, Rupak; Shan, Hongzhang; Sing, Jaswinder Pal

    2000-11-01

    Achieving scalable performance for dynamic irregular applications is eminently challenging. Traditional message-passing approaches have been making steady progress towards this goal; however, they suffer from complex implementation requirements. The use of a global address space greatly simplifies the programming task, but can degrade the performance of dynamically adapting computations. In this work, we examine two major classes of adaptive applications, under five competing programming methodologies and four leading parallel architectures. Results indicate that it is possible to achieve message-passing performance using shared-memory programming techniques by carefully following the same high level strategies. Adaptive applications have computational work loads and communication patterns which change unpredictably at runtime, requiring dynamic load balancing to achieve scalable performance on parallel machines. Efficient parallel implementations of such adaptive applications are therefore a challenging task. This work examines the implementation of two typical adaptive applications, Dynamic Remeshing and N-Body, across various programming paradigms and architectural platforms. We compare several critical factors of the parallel code development, including performance, programmability, scalability, algorithmic development, and portability.

  20. Evaluating transport in irregular pore networks

    Science.gov (United States)

    Klimenko, Dimitri A.; Hooman, Kamel; Klimenko, Alexander Y.

    2012-07-01

    A general approach for investigating transport phenomena in porous media is presented. This approach has the capacity to represent various kinds of irregularity in porous media without the need for excessive detail or computational effort. The overall method combines a generalized effective medium approximation (EMA) with a macroscopic continuum model in order to derive a transport equation with explicit analytical expressions for the transport coefficients. The proposed form of the EMA is an anisotropic and heterogeneous extension of Kirkpatrick's EMA [Rev. Mod. Phys.RMPHAT0034-686110.1103/RevModPhys.45.574 45, 574 (1973)] which allows the overall model to account for microscopic alterations in connectivity (with the locations of the pores and the orientation and length of the throat) as well as macroscopic variations in transport properties. A comparison to numerical results for randomly generated networks with different properties is given, indicating the potential for this methodology to handle cases that would pose significant difficulties to many other analytical models.

  1. Over rough and smooth : Amputee gait on an irregular surface

    NARCIS (Netherlands)

    Curtze, C.; Hof, A.L.; Postema, K.; Otten, B.

    2011-01-01

    When negotiating irregular surfaces, the control of dynamic stability is challenged. In this study, we compared the adjustments in stepping behaviour and arm-swing of 18 unilateral transtibial amputees and 17 able-bodied participants when walking on flat and irregular surfaces. Experimental findings

  2. Edge-partitioning graphs into regular and locally irregular components

    DEFF Research Database (Denmark)

    Bensmail, Julien; Stevens, Brett

    2016-01-01

    A graph is locally irregular if every two adjacent vertices have distinct degrees. Recently, Baudon et al. introduced the notion of decomposition into locally irregular subgraphs. They conjectured that for almost every graph G, there exists a minimum integer χ'irr(G) such that G admits an edge-pa...

  3. A Model of Irregular Impurity at the Surface of Nanoparticle and Catalytic Activity

    Institute of Scientific and Technical Information of China (English)

    I.V.Blinova; V.V.Gusarov; I.Yu.Popov

    2012-01-01

    A problem of nanocatalyst improvement is considered. The existence of irregularities at the surface of nanoparticle leads to the increasing of the surface/volume ratio and, correspondingly, to the improvement of the catalytic activity. But this impurity gives one an additional effect due to the change of the electronic density at the surface. We suggest simple model for the description of this effect. The model allows one to find the discrete spectrum of the Schrdinger operator for nanoparticle. Due to this impurity induced bound states the electron density increases near the surface. It leads to the increase of the catalytic activity of nanoparticles with surface impurities.

  4. Irregular conformal block, spectral curve and flow equations

    CERN Document Server

    Choi, Sang Kwan; Zhang, Hong

    2015-01-01

    Irregular conformal block is motivated by the Argyres-Douglas type of N=2 super conformal gauge theory. We investigate the classical/NS limit of the irregular conformal block using spectral curve on a Riemann surface with irregular punctures, which is equivalent to the loop equation of irregular matrix model. The spectral curve is reduced to the second order (Virasoro symmetry, $SU(2)$ for the gauge theory) and third order ($W_3$ symmetry, $SU(3)$) differential equations of a polynomial with finite degree. The Virasoro and W symmetry generate flow equations in the spectral curve and determine the irregular conformal block, hence the partition function of the Argyres-Douglas theory ala AGT conjecture.

  5. School setting and irregular lunch consumption among adolescents

    DEFF Research Database (Denmark)

    Pagh Pedersen, Trine; Holstein, Bjørn Evald; Rasmussen, Mette

    level variables and irregular lunch consumption. Lunch consumption was measured by lunch frequency questions. Results: We found that the school level factors, “Availability to canteen” and “Adult present in lunch breaks” were associated with irregular lunch consumption. Students with no access...... to canteen had a lower risk of having irregular lunch consumption OR=0.77 (0.62-0.96). Students with no adult present in lunch breaks had a higher risk of irregular lunch consumption OR=1.62 (1.32-1.99). Having irregular lunch consumption was associated with the following individual characteristics: boy, 7th...... the association. Conclusion: The structural setting of the school was associated with children and adolescents’ regularity of lunch consumption in a multilevel model controlled for individual level factors. From the findings we can conclude that availability of canteen and school stall did not promote regular...

  6. Imaging HF-induced large-scale irregularities above HAARP

    Science.gov (United States)

    Djuth, Frank T.; Reinisch, Bodo W.; Kitrosser, David F.; Elder, John H.; Snyder, A. Lee; Sales, Gary S.

    2006-02-01

    The University of Massachusetts-Lowell digisonde is used with the HAARP high-frequency (HF), ionospheric modification facility to obtain radio images of artificially-produced, large-scale, geomagnetic field-aligned irregularities. F region irregularities generated with the HAARP beam pointed in the vertical and geomagnetic field-aligned directions are examined in a smooth background plasma. It is found that limited large-scale irregularity production takes place with vertical transmissions, whereas there is a dramatic increase in the number of source irregularities with the beam pointed parallel to the geomagnetic field. Strong irregularity production appears to be confined to within ~5° of the geomagnetic zenith and does not fill the volume occupied by the HF beam. A similar effect is observed in optical images of artificial airglow.

  7. Processor Allocation for Optimistic Parallelization of Irregular Programs

    CERN Document Server

    Versaci, Francesco

    2012-01-01

    Optimistic parallelization is a promising approach for the parallelization of irregular algorithms: potentially interfering tasks are launched dynamically, and the runtime system detects conflicts between concurrent activities, aborting and rolling back conflicting tasks. However, parallelism in irregular algorithms is very complex. In a regular algorithm like dense matrix multiplication, the amount of parallelism can usually be expressed as a function of the problem size, so it is reasonably straightforward to determine how many processors should be allocated to execute a regular algorithm of a certain size (this is called the processor allocation problem). In contrast, parallelism in irregular algorithms can be a function of input parameters, and the amount of parallelism can vary dramatically during the execution of the irregular algorithm. Therefore, the processor allocation problem for irregular algorithms is very difficult. In this paper, we describe the first systematic strategy for addressing this pro...

  8. The periodic dynamics of the irregular heterogeneous celestial bodies

    Science.gov (United States)

    Lan, Lei; Yang, Mo; Baoyin, Hexi; Li, Junfeng

    2017-02-01

    In this paper, we develop a methodology to study the periodic dynamics of irregular heterogeneous celestial bodies. Heterogeneous bodies are not scarce in space. It has been found that bodies, such as 4 Vesta, 624 Hektor, 87 Sylvia, 16 Psyche and 25143 Itokawa, may all have varied internal structures. They can be divided into large-scale and small-scale cases. The varied internal structures of large-scale bodies always result from gradient pressure inside, which leads to compactness differences of the inner material. However, the heterogeneity of a small-scale body is always reflected by the different densities of different areas, which may originate from collision formation from multiple objects. We propose a modeling procedure for the heterogeneous bodies derived from the conventional polyhedral method and then compare its dynamical characteristics with those of the homogeneous case. It is found that zero-velocity curves, positions of equilibrium points, types of bifurcations in the continuation of the orbital family and the stabilities of periodic orbits near the heterogeneous body are different from those in the homogeneous case. The suborbicular orbits near the equatorial plane are potential parking orbits for a future mission, so we discuss the switching of the orbital stability of the family because it has fundamental significance to orbit maintenance and operations around actual asteroids.

  9. How a Stroke Is Diagnosed

    Science.gov (United States)

    ... News About Neurology Image Library Search The Internet Stroke Center Patients & Families About Stroke Stroke Diagnosis Stroke ... Diagnosis » How a Stroke is Diagnosed How a Stroke is Diagnosed How a Stroke is Diagnosed Lab ...

  10. How Is Testicular Cancer Diagnosed?

    Science.gov (United States)

    ... Cancer Early Detection, Diagnosis, and Staging How Is Testicular Cancer Diagnosed? Testicular cancer is usually found as a ... the tumor might have returned. Surgery to diagnose testicular cancer Most types of cancer are diagnosed by removing ...

  11. Diagnosing ADHD in Adolescence

    Science.gov (United States)

    Sibley, Margaret H.; Pelham, William E., Jr.; Molina, Brooke S. G.; Gnagy, Elizabeth M.; Waschbusch, Daniel A.; Garefino, Allison C.; Kuriyan, Aparajita B.; Babinski, Dara E.; Karch, Kathryn M.

    2012-01-01

    Objective: This study examines adolescent-specific practical problems associated with current practice parameters for diagnosing attention-deficit/hyperactivity disorder (ADHD) to inform recommendations for the diagnosis of ADHD in adolescents. Specifically, issues surrounding the use of self- versus informant ratings, diagnostic threshold, and…

  12. Being publicly diagnosed

    DEFF Research Database (Denmark)

    Konradsen, Hanne; Lillebaek, Troels; Wilcke, Torgny;

    2014-01-01

    . METHOD: A grounded theory design with field studies and qualitative interviews, following the recommendations from Glaser and Strauss. RESULT: A process of being publicly diagnosed was identified, which developed during the patient's trajectory from being on the way to becoming a patient, becoming...

  13. Diagnosing plant problems

    Science.gov (United States)

    Cheryl A. Smith

    2008-01-01

    Diagnosing Christmas tree problems can be a challenge, requiring a basic knowledge of plant culture and physiology, the effect of environmental influences on plant health, and the ability to identify the possible causes of plant problems. Developing a solution or remedy to the problem depends on a proper diagnosis, a process that requires recognition of a problem and...

  14. A comparison between large-scale irregularities and scintillations in the polar ionosphere

    Science.gov (United States)

    Zhang, Q. H.; Wang, Y.; Jayachandran, P. T.; Lockwood, M. M.; Zhang, S.; Moen, J.; Xing, Z. Y.; Ma, Y. Z.; Lester, M.

    2016-12-01

    A comparison between large-scale ionospheric irregularities recorded in the global GPS total electron content (TEC) and scintillations observed by Canadian High Arctic Ionospheric Network (CHAIN) are pursued during a geomagnetic storm. Clear irregularities, such as storm enhanced density, middle-latitude trough and polar cap patches, are identified from the TEC maps, together with the modeling auroral oval. At the edges of these irregularities, clear scintillations appeared but their behaviors were different. Phase scintillations (σφ) were much larger than amplitude scintillations (S4) both in the SED segmented area and at the equatorward edge of the middle-latitude trough in post-noon sector, associated with the bursty flows or flow reversals. S4 and σφ were small in the polar cap with small enhancements due to the varied flows with the density gradient at the edges of polar cap patches. While S4 were much larger than σφ in the auroral oval due to the particle precipitations.

  15. TINITALY/01: a new Triangular Irregular Network of Italy

    Directory of Open Access Journals (Sweden)

    M. T. Pareschi

    2007-06-01

    Full Text Available A new Digital Elevation Model (DEM of the natural landforms of Italy is presented. A methodology is discussed to build a DEM over wide areas where elevation data from non-homogeneous (in density and accuracy input sources are available. The input elevation data include contour lines and spot heights derived from the Italian Regional topographic maps, satellite-based global positioning system points, ground based and radar altimetry data. Owing to the great heterogeneity of the input data density, the DEM format that better preserves the original accuracy is a Triangular Irregular Network (TIN. A Delaunay-based TIN structure is improved by using the DEST algorithm that enhances input data by evaluating inferred break-lines. Accordingly to this approach, biased distributions in slopes and elevations are absent. To prevent discontinuities at the boundary between regions characterized by data with different resolution a cubic Hermite blending weight S-shaped function is adopted. The TIN of Italy consists of 1.39×109 triangles. The average triangle area ranges from 12 to about 13000 m2 accordingly to different morphologies and different sources. About 50% of the model has a local average triangle area <500 m2. The vertical accuracy of the obtained DEM is evaluated by more than 200000 sparse control points. The overall Root Mean Square Error (RMSE is less than 3.5 m. The obtained national-scale DEM constitutes an useful support to carry out accurate geomorphological and geological investigations over large areas. The problem of choosing the best step size in deriving a grid from a TIN is then discussed and a method to quantify the loss of vertical information is presented as a function of the grid step. Some examples of DEM application are outlined. Under request, an high resolution stereo image database of the whole Italian territory (derived from the presented DEM is available to browse via internet.

  16. Predicted and observed characteristics of small-scale field-aligned irregularities generated in the F-region by low power HF heating

    Directory of Open Access Journals (Sweden)

    E. Kolesnikova

    Full Text Available Simultaneous HF scattering from the different regions of the heated volume is used to investigate characteristics of the small-scale field-aligned irregularities in the F-region. Time of growth, decay rate and saturation level for different pump powers are deduced from the observations and are compared with their behaviour predicted by the thermal parametric instability model. As a result, the estimates of the density and of the temperature modifications inside of the irregularities are obtained.

    Key words. Ionosphere (ionospheric irregularities

  17. Mass-to-Light versus Color Relations for Dwarf Irregular Galaxies

    Science.gov (United States)

    Herrmann, Kimberly A.; Hunter, Deidre Ann; Zhang, Hong-Xin; Elmegreen, Bruce; LITTLE THINGS

    2017-01-01

    We have determined new relations between UBV colors and mass-to-light (M/L) ratios for dwarf irregular galaxies, as well as for transformed g‧ - r‧. These M/L to color relations (MLCRs) are based on stellar mass density profiles determined for 34 LITTLE THINGS dwarfs from spectral energy distribution fitting to multi-wavelength surface photometry in passbands from the FUV to the NIR. These relations can be used to determine stellar masses in dwarf irregular galaxies for situations where other determinations of stellar mass are not possible. Our MLCRs are shallower than comparable MLCRs in the literature determined for spiral galaxies. We divided our dwarf data into four metallicity bins and found indications of a steepening of the MLCR with increased oxygen abundance, perhaps due to more line blanketing occurring at higher metallicity.

  18. Irregularities Associated with Artificially Created Dusty Plasmas in the near Earth Space Environment

    Science.gov (United States)

    Bordikar, M. R.; Scales, W.; Mahmoudian, A.; Fu, H.

    2009-12-01

    A natural dust layer formed by tons of meteoric dust spans the altitude range between 80 and 100 kilometers of the earth’s upper mesosphere and lower thermosphere which forms Noctilucent Clouds NLCs. These dust layers are charged due to collection of electrons and ions from the earth’s ionosphere. Polar Mesospheric Summer Echoes are radar echoes which result from scattering from the irregularities in the electron density above the NLC altitude. An alternate approach to understanding natural dust layers is to perform active space experiments in which a dust cloud is artificially created in a controlled manner in the upper atmosphere. The goal of Charged Aerosol Release Experiment (CARE) is to investigate similarity in plasma irregularity associated with natural and artificial dust layers. This presentation will address some of the physical processes expected to be important during the early time phase after creation of an artificial dust cloud in the earth’s ionosphere. Of major importance will be the production of plasma irregularities which may lead to radar echoes and the possibility of their relationship to PMSEs observed from natural dusty space plasmas. The objective is to investigate the production of electron irregularities due to growth of plasma instabilities driven by inhomogeneities in the boundary between the background plasma and the expanding charged dust layer. First, a two dimensional plasma simulation model will be described that may be used for examining early time evolution after expansion of an artificial dust cloud across the magnetic field in the ionosphere. The model considers a three species system with fluid electrons and ions and Particle-In-Cell PIC charged dust grains in which the dust charge on the grains varies in time according to the standard charging model. The electrons are magnetized and the algorithm incorporates the parallel electron dynamics while the ions are assumed to be unmagnetized. Simulations runs were made to

  19. Menarche delay and menstrual irregularities persist in adolescents with type 1 diabetes

    Directory of Open Access Journals (Sweden)

    McFann Kim

    2011-05-01

    Full Text Available Abstract Background Menarche delay has been reported in adolescent females with type 1 diabetes (T1DM, perhaps due to poor glycemic control. We sought to compare age at menarche between adolescent females with T1DM and national data, and to identify factors associated with delayed menarche and menstrual irregularity in T1DM. Methods This was a cross-sectional study and females ages 12- 24 years (n = 228 with at least one menstrual period were recruited during their outpatient diabetes clinic appointment. The National Health and Nutrition Examination Survey (NHANES 2001-2006 data (n = 3690 for females 12-24 years were used as a control group. Results Age at menarche was later in adolescent females with T1DM diagnosed prior to menarche (12.81 +/- 0.09 years (mean+/- SE (n = 185 than for adolescent females diagnosed after menarche (12.17 0.19 years, p = 0.0015 (n = 43. Average age of menarche in NHANES was 12.27 +/- 0.038 years, which was significantly earlier than adolescent females with T1DM prior to menarche (p p = 0.77. Older age at menarche was negatively correlated with BMI z-score (r = -0.23 p = 0.0029 but not hemoglobin A1c (A1c at menarche (r = 0.01, p = 0.91. Among 181 adolescent females who were at least 2 years post menarche, 63 (35% reported usually or always irregular cycles. Conclusion Adolescent females with T1DM had a later onset of menarche than both adolescent females who developed T1DM after menarche and NHANES data. Menarche age was negatively associated with BMI z-score, but not A1c. Despite improved treatment in recent decades, menarche delay and high prevalence of menstrual irregularity is still observed among adolescent females with T1DM.

  20. Liability for Diagnosing Malingering.

    Science.gov (United States)

    Weiss, Kenneth J; Van Dell, Landon

    2017-09-01

    Malingering is a medical diagnosis, but not a psychiatric disorder. The label imputes that an evaluee has intentionally engaged in false behavior or statements. By diagnosing malingering, psychiatrists pass judgment on truthfulness. Evaluees taking exception to the label may claim that the professional has committed defamation of character (libel or slander) when the diagnosis is wrong and costs the claimant money or benefits. Clinicians may counter by claiming immunity or that the diagnosis was made in good faith. This problem has come into focus in military and veterans' contexts, where diagnoses become thresholds for benefits. Through historical and literary examples, case law, and military/veterans' claims of disability and entitlement, the authors examine the potency of the malingering label and the potential liability for professionals and institutions of making this diagnosis. © 2017 American Academy of Psychiatry and the Law.

  1. Orbital maneuvers around irregular shaped bodies

    Science.gov (United States)

    Venditti, Flaviane; Rocco, E. M.; Almeida Prado, A. B.

    2013-05-01

    Abstract (2,250 Maximum Characters): In the solar system there are many small bodies called asteroids. The large majority of these bodies are located in the asteroid belt, between the orbits of the planets Mars and Jupiter. The Near- Earth Objects, or NEOs, are objects with perihelion below 1.3AU, which include comets and asteroids. The NEOs are considered to have orbits passing close to the Earth’s orbit and, in the case of asteroids, are called Near-Earth Asteroids (NEAs). Among the NEAs there are bodies considered potentially hazardous asteroids (PHAs), whose minimum orbit intersection distance with Earth is 0.05AU and that have absolute magnitude (H) of 22, which would mean an asteroid of at least 110-240 meters, depending on its albedo. One of the major characteristic of the asteroids is the irregular shape, causing the dynamics of orbits around these bodies to be different from a spherical shaped one. The fact that an object is not spherical generates a perturbation on the gravitational field. The disturbing force can be determined considering the shape of the specific body. A satellite orbiting this body would suffer the effects of this perturbation, but knowing the disturbing force, it’s possible to correct and control the orbit according to the desired mission. The polyhedron method is a traditional way to model an asteroid by dividing the object into smaller parts. The data used on this work are composed by a combination of triangular faces. The total disturbing force is a sum of the force on each piece of the model. Therefore, after the simulations are obtained, it’s possible to apply the desired corrections of the perturbation using continuous low thrust in closed loop, making it possible to perform maneuvers near these bodies. One of the important applications of the study shown above is in the ASTER mission, that is under study by INPE and several other Brazilian academic institutions, which goal is to send a spacecraft to an asteroid and then

  2. DC Electric Fields, Associated Plasma Drifts, and Irregularities Observed on the C/NOFS Satellite

    Science.gov (United States)

    Pfaff, R.; Freudenreich, H.; Klenzing, J.

    2011-01-01

    Results are presented from the Vector Electric Field Investigation (VEFI) on the Air Force Communication/Navigation Outage Forecasting System (C/NOFS) satellite, a mission designed to understand, model, and forecast the presence of equatorial ionospheric irregularities. The VEFI instrument includes a vector DC electric field detector, a fixed-bias Langmuir probe operating in the ion saturation regime, a flux gate magnetometer, an optical lightning detector, and associated electronics including a burst memory. Compared to data obtained during more active solar conditions, the ambient DC electric fields and their associated E x B drifts are variable and somewhat weak, typically < 1 mV/m. Although average drift directions show similarities to those previously reported, eastward/outward during day and westward/downward at night, this pattern varies significantly with longitude and is not always present. Daytime vertical drifts near the magnetic equator are largest after sunrise, with smaller average velocities after noon. Little or no pre-reversal enhancement in the vertical drift near sunset is observed, attributable to the solar minimum conditions creating a much reduced neutral dynamo at the satellite altitude. The nighttime ionosphere is characterized by larger amplitude, structured electric fields, even where the plasma density appears nearly quiescent. Data from successive orbits reveal that the vertical drifts and plasma density are both clearly organized with longitude. The spread-F density depletions and corresponding electric fields that have been detected thus far have displayed a preponderance to appear between midnight and dawn. Associated with the narrow plasma depletions that are detected are broad spectra of electric field and plasma density irregularities for which a full vector set of measurements is available for detailed study. The VEFI data represents a new set of measurements that are germane to numerous fundamental aspects of the electrodynamics

  3. The irregularities of the sunspot cycle and their theoretical modelling

    CERN Document Server

    Choudhuri, Arnab Rai

    2013-01-01

    The 11-year sunspot cycle has many irregularities, the most promi- nent amongst them being the grand minima when sunspots may not be seen for several cycles. After summarizing the relevant observational data about the irregularities, we introduce the flux transport dynamo model, the currently most successful theoretical model for explaining the 11-year sunspot cycle. Then we analyze the respective roles of nonlinearities and random fluctuations in creating the irregularities. We also discuss how it has recently been realized that the fluctuations in meridional circula- tion also can be a source of irregularities. We end by pointing out that fluctuations in the poloidal field generation and fluctuations in meridional circulation together can explain the occurrences of grand minima.

  4. Land Elevation TINs (Triangulated Irregular Networks) for Jefferson County, WI

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — The Land Elevation TINs (Triangulated Irregular Networks) in this directory are generated from 2 foot contour lines from Jefferson County. Little is known about the...

  5. Approximate design calculation methods for radiation streaming in shield irregularities

    Energy Technology Data Exchange (ETDEWEB)

    Miura, Toshimasa; Hirao, Yoshihiro [Ship Research Inst., Mitaka, Tokyo (Japan); Yoritsune, Tsutomu

    1997-10-01

    Investigation and assessment are made for approximate design calculation methods of radiation streaming in shield irregularities. Investigation is made for (1) source, (2) definition of streaming radiation components, (3) calculation methods of streaming radiation, (4) streaming formulas for each irregularity, (5) difficulties in application of streaming formulas, etc. Furthermore, investigation is made for simple calculation codes and albedo data. As a result, it is clarified that streaming calculation formulas are not enough to cover various irregularities and their accuracy or application limit is not sufficiently clear. Accurate treatment is not made in the formulas with respect to the radiation behavior for slant incidence, bend part, offset etc., that results in too much safety factors in the design calculation and distrust of the streaming calculation. To overcome the state and improve the accuracy of the design calculation for shield irregularities, it is emphasized to assess existing formulas and develop better formulas based on systematic experimental studies. (author)

  6. What Are the Common Treatments for Menstrual Irregularities?

    Science.gov (United States)

    ... the menstrual problem, such as counseling for an eating disorder or extreme excercise Treatment for menstrual irregularities that ... Home Contact Accessibility Web Policies and Notices FOIA Facebook Twitter Pinterest YouTube RSS NIH...Turning Discovery Into ...

  7. Characteristics of low latitude ionospheric E-region irregularities linked with daytime VHF scintillations measured from Varanasi

    Indian Academy of Sciences (India)

    K Patel; A K Singh; R P Patel; R P Singh

    2009-12-01

    VHF amplitude scintillations recorded during the daytime period from January 1991 to December 1993, April 1998 to December 1999 and January 2008 to December 2008 at low latitude station Varanasi (geographic lat. = 25° 15′N; long. = 82° 59′E; geomagnetic lat. = 14° 55′N, long. = 154°E, dip angle = 37.3°, sub-ionospheric dip = 34°) have been analyzed to study the behaviour of ionospheric E-region irregularities during the active solar and magnetic periods. The autocorrelation functions, power spectral densities, signal de-correlation times are computed to study the temporal features of ionospheric E-region irregularities linked with daytime scintillations. Derived spectral index ranges between −2 and −9. Assuming velocity of irregularities, the characteristic lengths of the E-region irregularities are estimated. We have estimated the minimum and maximum range of scale length of sporadic-E () irregularities to be observed over Varanasi. These results are in close agreement with those reported from this latitude region.

  8. Helicopters in Irregular Warfare: Algeria, Vietnam, and Afghanistan

    Science.gov (United States)

    2013-06-13

    the political group associated with the Algerian nationalist independence movement GALAT Groupement d’ Aviation Légère de l’Armée de Terre ...unique from most conflicts because the expeditionary forces’ parent country rarely perceives an existential threat.19 The lack of perceived threat...dominance rarely guarantees success in irregular warfare.22 Instead, success in irregular warfare requires synergy between government and military efforts

  9. Menstrual Irregularity and Musculoskeletal Injury in Female High School Athletes

    Science.gov (United States)

    Thein-Nissenbaum, Jill M.; Rauh, Mitchell J.; Carr, Kathleen E.; Loud, Keith J.; McGuine, Timothy A.

    2012-01-01

    Context: The female athlete triad describes the interrelatedness of energy availability, menstrual function, and bone density. Although associations between triad components and musculoskeletal injury (INJ) have been reported in collegiate athletes, limited information exists about menstrual irregularity (MI) and INJ in the high school population. Objective: To determine the prevalence of and relationship between MI and INJ in high school athletes. Design: Cross-sectional study. Setting: High schools. Patients or Other Participants: The sample consisted of 249 female athletes from 3 high schools who competed in 33 interscholastic, school-sponsored sport teams, dance teams, and cheerleading or pom-pon squad during the 2006–2007 school year. Each athlete remained on the roster throughout the season. Main Outcome Measure(s): Participants completed a survey regarding injury type, number of days of sport participation missed, and menstrual history in the past year. Results: The prevalences of MI and INJ were 19.7% and 63.1%, respectively. Athletes who reported MI sustained a higher percentage of severe injuries (missing ≥22 days of practice or competition) than did athletes who reported normal menses. Although the trend was not significant, athletes with MI were almost 3 times more likely to sustain an injury resulting in 7 or more days of time lost from sport (odds ratio = 2.7, 95% confidence interval = 0.8, 8.8) than those who sustained an injury resulting in 7 or fewer days of time lost. Conclusions: The incidences of MI and INJ in this high school population during the study period were high. Athletes who reported MI sustained a higher percentage of severe injuries than did athletes who reported normal menses. Education programs to increase knowledge and improve management of MI and its potential effects on injury in female high school athletes are warranted. PMID:22488233

  10. Irregular-Moons Science Today and in Cassini's Final Three Years

    Science.gov (United States)

    Denk, T.; Mottola, S.

    2014-12-01

    The outer or irregular moons belong to the by far most numerous, but least investigated group of moons in the Saturnian system. The group is comprised of at least 38, mainly small objects which orbit at quite large distances to the planet, the rings, the inner regular moon system, and the Cassini spacecraft. As seen from Earth, their apparent visual magnitudes mainly range from ~20 to >25, the phase angles from 0 to 6°. From Cassini, some irregular moons can reach pole-axis directions, convex-hull shapes, and sidereal periods. So far, lightcurve inversion of Ymir revealed a convex shape reminiscent to a triangular prism and a spin-axis direction close to the South Ecliptic pole. The figure shows the lightcurve at 64° phase (bottom left panel), and four equatorial and two polar views of the derived shape model are shown at bottom right. Within Cassini's final three years in Saturn orbit, further observations offer the potential of pole and shape determinations for up to 15 irregular moons and up to 30 rotational periods total. These data may reveal (or already do so) hemispherical color variations, limits for object densities and sizes, pole-direction patterns, correlations of spin frequencies to orbit parameters, and hints for contact binaries or binary natures of the moons. Such information, besides its value per se, provides constraints for the investigation on the formation and evolutionary processes within the Saturnian satellite system.

  11. Experimental and theoretical study of the onset of the growth of an irregular metal electrodeposit

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Graciela [Laboratoire de Physique de la Matiere Condensee, CNRS-Ecole Polytechnique, F91128 Palaiseau Cedex (France); Laboratorio de Sistemas Complejos, Departamento de Computacion, Facultad de Ciencias, Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires (Argentina); Rosso, Michel; Chazalviel, Jean-Noel [Laboratoire de Physique de la Matiere Condensee, CNRS-Ecole Polytechnique, F91128 Palaiseau Cedex (France); Chassaing, Elisabeth [IRDEP, EDF R and D, 6 Quai Watier, 78401 Chatou (France)

    2007-11-20

    Electrodeposition of a metal can produce aggregates with very irregular morphologies, in particular dendrites. In order to better understand these phenomena, we studied the preliminary stage of copper growth from copper sulfate by in situ optical experiments and impedance spectroscopy. Experiments were performed in a thin layer cell put in a vertical position, with cathode on top. Using a vertical cell instead of a horizontal one tends to stabilize the electrochemical system. The concentration measured by optical absorption is in agreement with theoretical prediction at the onset of polarization. Close to the limiting current density, oscillations were observed in the cell voltage. Impedance spectra could be fitted either using a simple equivalent circuit at low current density, or more complex calculations at high current density. (author)

  12. Identification of the plasma instabilities responsible for decameter-scale ionospheric irregularities on plasmapause field lines

    Science.gov (United States)

    Eltrass, Ahmed; Ruohoniemi, J. Michael; Mahmoudian, Alireza; Scales, Wayne; De Larquier, Sebastien; Baker, Joseph; Greenwald, Ray; Erickson, Philip

    The mid-latitude SuperDARN radars have revealed decameter-scale ionospheric irregularities during quiet geomagnetic periods that have been proposed to be responsible for the observed low-velocity Sub-Auroral Ionospheric Scatter (SAIS). The mechanism responsible for the growth of such common irregularities is still unknown. Joint measurements by Millstone Hill Incoherent Scatter Radar (ISR) and SuperDARN HF radar located at Wallops Island, Virginia reported by Greenwald et al. [2006] have determined decameter-scale irregularities with low drift velocities in the quiet-time mid-latitude night-side ionosphere. Temperature gradient instability (TGI) is investigated as the cause of irregularities associated with these SuperDARN echoes. The electrostatic dispersion relation for TGI has been extended into the kinetic regime appropriate for SuperDARN radar frequencies by including Landau damping, finite gyro-radius effects, and temperature anisotropy. This dispersion relation allows study of the TGI over a wide range of parameter regimes that have not been considered for such ionospheric applications up to this time. The calculations of electron temperature and density gradients in the direction perpendicular to the geomagnetic field have shown that the TGI growth is possible in the top-side F-region for the duration of the experiment. A time series for the growth rate has been developed for mid-latitude ionospheric irregularities observed by SuperDARN in the top-side F-region [Greenwald et al., 2006]. This time series is computed for both perpendicular and meridional density and temperature gradients. These observations show the role of TGI is dominant over the gradient drift instability (GDI) in this case. Nonlinear evolution of the TGI has been studied utilizing gyro-kinetic "Particle In Cell" (PIC) simulations with Monte Carlo collisions. This allows detailed study of saturation amplitude, particle flux, heat flux, diffusion coefficient, and thermal diffusivity of the

  13. Diagnosable structured logic array

    Science.gov (United States)

    Whitaker, Sterling (Inventor); Miles, Lowell (Inventor); Gambles, Jody (Inventor); Maki, Gary K. (Inventor)

    2009-01-01

    A diagnosable structured logic array and associated process is provided. A base cell structure is provided comprising a logic unit comprising a plurality of input nodes, a plurality of selection nodes, and an output node, a plurality of switches coupled to the selection nodes, where the switches comprises a plurality of input lines, a selection line and an output line, a memory cell coupled to the output node, and a test address bus and a program control bus coupled to the plurality of input lines and the selection line of the plurality of switches. A state on each of the plurality of input nodes is verifiably loaded and read from the memory cell. A trusted memory block is provided. The associated process is provided for testing and verifying a plurality of truth table inputs of the logic unit.

  14. How Is Pelvic Pain Diagnosed?

    Science.gov (United States)

    ... Information Clinical Trials Resources and Publications How is pelvic pain diagnosed? Skip sharing on social media links Share ... needed to help diagnose the cause of the pelvic pain. These tests or procedures may include 1 , 2 : ...

  15. How Is Kawasaki Disease Diagnosed?

    Science.gov (United States)

    ... page from the NHLBI on Twitter. How Is Kawasaki Disease Diagnosed? Kawasaki disease is diagnosed based on your child's signs ... are the first to suspect a child has Kawasaki disease. Pediatricians are doctors who specialize in treating ...

  16. How Is Lactose Intolerance Diagnosed?

    Science.gov (United States)

    ... Information Clinical Trials Resources and Publications How is lactose intolerance diagnosed? Skip sharing on social media links ... people think that they or their children are lactose intolerant without being tested or diagnosed. 1 As ...

  17. Diagnosing Dementia--Positive Signs

    Science.gov (United States)

    ... Navigation Bar Home Current Issue Past Issues Diagnosing Dementia—Positive Signs Past Issues / Fall 2007 Table of ... easy, affordable blood test that could accurately diagnose Alzheimer's disease (AD)—even before symptoms began to show? Researchers ...

  18. On irregular conformal blocks, with an application to the Painlev\\'e functions

    CERN Document Server

    Nagoya, Hajime

    2015-01-01

    We develop the theory on irregular conformal blocks of the Virasoro algebra. In previous studies, expansions of irregular conformal blocks at regular singular points were obtained as degeneration limits of regular conformal blocks, however, expansions of those at irregular singular points were not understood clearly. This is because precise definitions of irregular vertex operators had not given before. In this paper, we give precise definitions of irregular vertex operators of two kinds and conjecture that they exist uniquely. Then, we define irregular conformal blocks with at most two irregular singular points, as expectation values of the given irregular vertex operators. Our definitions give an understanding of expansions of irregular conformal blocks and are enable us to obtain expansions at irregular singular points. As an application, we give conjectural formulas of Fourier expansions of the tau functions of the fifth and fourth Painlev\\'e functions, using expansions of irregular conformal blocks at an...

  19. Dark Matter and the Chemical Evolution of Irregular Galaxies

    Directory of Open Access Journals (Sweden)

    L. Carigi

    2001-01-01

    Full Text Available We present three types of chemical evolution models for irregular galaxies: closed-box with continuous star formation rates (SFRs, closed-box with burstin g SFRs, and O-rich outflow with continuous SFRs. We discuss the chemical evolution of the irregular galaxies NGC 1560 and II Zw 33, and a "typical" irregular galaxy. The fraction of low-mass stars needed by our models is larger than that derived for the solar vicinity, but similar to that found in globular clusters. For our typical irregular galaxy we need a mass fraction of about 40% in the form of substellar objects plus non baryonic dark matter inside the Holmberg radius, in good agreement with the results derived for NGC 1560 and II Zw 33 where we do have an independent estimate of the mass fraction in non baryonic dark matter. Closed-box models are better than O-rich outflow models in explaining the C/O and Z/O observed values for our typical irregular galaxy.

  20. Regulation of Irregular Neuronal Firing by Autaptic Transmission

    Science.gov (United States)

    Guo, Daqing; Wu, Shengdun; Chen, Mingming; Perc, Matjaž; Zhang, Yangsong; Ma, Jingling; Cui, Yan; Xu, Peng; Xia, Yang; Yao, Dezhong

    2016-05-01

    The importance of self-feedback autaptic transmission in modulating spike-time irregularity is still poorly understood. By using a biophysical model that incorporates autaptic coupling, we here show that self-innervation of neurons participates in the modulation of irregular neuronal firing, primarily by regulating the occurrence frequency of burst firing. In particular, we find that both excitatory and electrical autapses increase the occurrence of burst firing, thus reducing neuronal firing regularity. In contrast, inhibitory autapses suppress burst firing and therefore tend to improve the regularity of neuronal firing. Importantly, we show that these findings are independent of the firing properties of individual neurons, and as such can be observed for neurons operating in different modes. Our results provide an insightful mechanistic understanding of how different types of autapses shape irregular firing at the single-neuron level, and they highlight the functional importance of autaptic self-innervation in taming and modulating neurodynamics.

  1. Photometry of Irregular Satellites of Uranus and Neptune

    CERN Document Server

    Grav, T

    2004-01-01

    We present BVR photometric colors of six Uranian and two Neptunian irregular satellites, collected using the Magellan Observatory (Las Campanas, Chile) and the Keck Observatory, (Manua Kea, Hawaii). The colors range from neutral to light red, and like the Jovian and the Saturnian irregulars (Grav et al. 2003) there is an apparent lack of the extremely red objects found among the Centaurs and Kuiper belt objects. The Uranian irregulars can be divided into three possible dynamical families, but the colors collected show that two of these dynamical families, the Caliban and Sycorax-clusters, have heterogeneous colors. Of the third possible family, the 168-degree cluster containing two objects with similar average inclinations but quite different average semi-major axis, only one object (U XXI Trinculo) was observed. The heterogeneous colors and the large dispersion of the average orbital elements leads us to doubt that they are collisional families. We favor single captures as a more likely scenario. The two nep...

  2. BVR Color Survey of the Jovian Irregular Satellites

    Science.gov (United States)

    Rettig, T. W.; Walsh, K.

    2002-09-01

    BVR colors and magnitudes are presented for four Jovian irregular prograde satellites (Himalia J6, Elara J7, Lysithea J10 and Leda J13) and four irregular retrograde satellites (Pasiphae J8, Sinope J9, Carme J11 and Ananke J12). All eight have generally `solar' colors but the retrograde group has slightly redder and more diverse colors. The strikingly similar colors of the four prograde satellites suggests the parent planetesimal was likely very homogeneous. The four retrograde satellites show diversity in color that suggests a heterogeneous progenitor and thus, variations in pre-capture formation history. The absolute magnitudes and revised diameters are presented. We also report new colors and diameters for two Uranian irregular satellites (Caliban (S/1997 U1) and Sycorax (S/1997 U2)). The Uranian satellite colors are slightly redder than the eight Jovian satellites studied.

  3. A BVR Colors of Eight Jovian Irregular Satellites -- Evolutionary Implications

    Science.gov (United States)

    Rettig, T. W.; Walsh, K.

    2001-11-01

    We present BVR colors and magnitudes for four Jovian irregular prograde satellites (Himalia J6, Elara J7, Lysithea J10 and Leda J13) and four irregular retrograde satellites (Pasiphae J8, Sinope J9, Carme J11 and Ananke J12). All eight have generally `solar' colors but the retrograde group has slightly redder and more diverse colors. The strikingly similar colors of the four prograde satellites suggests the parent planetesimal was likely very homogeneous. The four retrograde satellites show diversity in color that suggests a heterogeneous progenitor and thus, variations in pre-capture formation history. The absolute magnitudes and revised diameters are presented. We also report new colors and diameters for two Uranian irregular satellites (Caliban (S/1997 U1) and Sycorax (S/1997 U2)) that are slightly redder than any of these Jovian satellites.

  4. Dynamical Configurations of Celestial Systems Comprised of Multiple Irregular Bodies

    CERN Document Server

    Jiang, Yu; Baoyin, Hexi; Li, Junfeng

    2016-01-01

    This manuscript considers the main features of the nonlinear dynamics of multiple irregular celestial body systems. The gravitational potential, static electric potential, and magnetic potential are considered. Based on the three established potentials, we show that three conservative values exist for this system, including a Jacobi integral. The equilibrium conditions for the system are derived and their stability analyzed. The equilibrium conditions of a celestial system comprised of n irregular bodies are reduced to 12n minus 9 equations. The dynamical results are applied to simulate the motion of multiple-asteroid systems. The simulation is useful for the study of the stability of multiple irregular celestial body systems and for the design of spacecraft orbits to triple asteroid systems discovered in the solar system. The dynamical configurations of the five triple-asteroid systems 45 Eugenia, 87 Sylvia, 93 Minerva, 216 Kleopatra, and 136617 1994CC, and the six-body system 134340 Pluto are calculated and...

  5. Track Irregularity Time Series Analysis and Trend Forecasting

    Directory of Open Access Journals (Sweden)

    Jia Chaolong

    2012-01-01

    Full Text Available The combination of linear and nonlinear methods is widely used in the prediction of time series data. This paper analyzes track irregularity time series data by using gray incidence degree models and methods of data transformation, trying to find the connotative relationship between the time series data. In this paper, GM (1,1 is based on first-order, single variable linear differential equations; after an adaptive improvement and error correction, it is used to predict the long-term changing trend of track irregularity at a fixed measuring point; the stochastic linear AR, Kalman filtering model, and artificial neural network model are applied to predict the short-term changing trend of track irregularity at unit section. Both long-term and short-term changes prove that the model is effective and can achieve the expected accuracy.

  6. A 2-D NUMERICAL IRREGULAR WAVE TANK AND ITS VERIFICATION

    Institute of Scientific and Technical Information of China (English)

    LI Ben-xia; YU Xi-ping; YU Yu-xiu

    2005-01-01

    A two-dimensional numerical irregular wave tank based on the potential wave theory was developed.A source term was used inside the domain to generate waves, and outgoing waves were dissipated by sponge layers and transmitted by radiation boundary.The σ-coordinate transformation was introduced to map the time-dependent irregular physical domain to a fixed regular computational domain, and thus the free surface and bottom boundary conditions could be implemented precisely.The model was verified by simulating the nonlinear regular and irregular wave propagation on constant-depth water, as well as regular waves reflected from a vertical wall, and satisfactory agreement between numerical results and analytical solutions was obtained.The present numerical model is proved to be an effective tool for a long-duration simulation of coastal wave dynamics where the wave reflection is significant.

  7. Diagnosing oceanic nutrient deficiency

    Science.gov (United States)

    Moore, C. Mark

    2016-11-01

    The supply of a range of nutrient elements to surface waters is an important driver of oceanic production and the subsequent linked cycling of the nutrients and carbon. Relative deficiencies of different nutrients with respect to biological requirements, within both surface and internal water masses, can be both a key indicator and driver of the potential for these nutrients to become limiting for the production of new organic material in the upper ocean. The availability of high-quality, full-depth and global-scale datasets on the concentrations of a wide range of both macro- and micro-nutrients produced through the international GEOTRACES programme provides the potential for estimation of multi-element deficiencies at unprecedented scales. Resultant coherent large-scale patterns in diagnosed deficiency can be linked to the interacting physical-chemical-biological processes which drive upper ocean nutrient biogeochemistry. Calculations of ranked deficiencies across multiple elements further highlight important remaining uncertainties in the stoichiometric plasticity of nutrient ratios within oceanic microbial systems and caveats with regards to linkages to upper ocean nutrient limitation. This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.

  8. Diagnosing mucopolysaccharidosis IVA.

    Science.gov (United States)

    Wood, Timothy C; Harvey, Katie; Beck, Michael; Burin, Maira Graeff; Chien, Yin-Hsiu; Church, Heather J; D'Almeida, Vânia; van Diggelen, Otto P; Fietz, Michael; Giugliani, Roberto; Harmatz, Paul; Hawley, Sara M; Hwu, Wuh-Liang; Ketteridge, David; Lukacs, Zoltan; Miller, Nicole; Pasquali, Marzia; Schenone, Andrea; Thompson, Jerry N; Tylee, Karen; Yu, Chunli; Hendriksz, Christian J

    2013-03-01

    Mucopolysaccharidosis IVA (MPS IVA; Morquio A syndrome) is an autosomal recessive lysosomal storage disorder resulting from a deficiency of N-acetylgalactosamine-6-sulfate sulfatase (GALNS) activity. Diagnosis can be challenging and requires agreement of clinical, radiographic, and laboratory findings. A group of biochemical genetics laboratory directors and clinicians involved in the diagnosis of MPS IVA, convened by BioMarin Pharmaceutical Inc., met to develop recommendations for diagnosis. The following conclusions were reached. Due to the wide variation and subtleties of radiographic findings, imaging of multiple body regions is recommended. Urinary glycosaminoglycan analysis is particularly problematic for MPS IVA and it is strongly recommended to proceed to enzyme activity testing even if urine appears normal when there is clinical suspicion of MPS IVA. Enzyme activity testing of GALNS is essential in diagnosing MPS IVA. Additional analyses to confirm sample integrity and rule out MPS IVB, multiple sulfatase deficiency, and mucolipidoses types II/III are critical as part of enzyme activity testing. Leukocytes or cultured dermal fibroblasts are strongly recommended for enzyme activity testing to confirm screening results. Molecular testing may also be used to confirm the diagnosis in many patients. However, two known or probable causative mutations may not be identified in all cases of MPS IVA. A diagnostic testing algorithm is presented which attempts to streamline this complex testing process.

  9. Modeling of Plasma Irregularities in Expanding Ionospheric Dust Clouds

    Science.gov (United States)

    Fu, H.; Scales, W.; Mahmoudian, A.; Bordikar, M. R.

    2009-12-01

    Natural dust layers occur in the earth’s mesosphere (50km-85km). Plasma irregularities are associated with these natural dust layers that produce radar echoes. Recently, an Ionospheric sounding rocket experiment was performed to investigate the plasma irregularities in upper atmospheric dust layers. The Charged Aerosol Release Experiment (CARE) uses a rocket payload injection of particles in the ionosphere to determine the mechanisms for enhanced radar scatter from plasma irregularities embedded in artificial dusty plasma in space. A 2-D hybrid computational model is described that may be used to study a variety of irregularities in dusty space plasmas which may lead to radar echoes. In this model, the dust and ions are both treated with Particle-In-Cell method while the dust charge varies with time based on the standard dust Orbit Motion Limited charging model. A stochastic model is adopted to remove particle ions due to the dust charging process. Electrons are treated with a fluid model including the parallel dynamics of magnetic fields. Fourier spectral methods with a predictor-corrector time advance are used to solve it. This numerical model will be used to investigate the electrodynamics and several possible plasma irregularity generation mechanisms after the creation of an artificial dust layer. The first is the dust ion-acoustic instability due to the drift of dust relative to the plasma. The instability saturates by trapping some ions. The effects of dust radius and dust drift velocity on plasma irregularities will be analyzed further. Also, a shear- driven instability in expanding dusty clouds is investigated.

  10. Irregular Shaped Building Design Optimization with Building Information Modelling

    Directory of Open Access Journals (Sweden)

    Lee Xia Sheng

    2016-01-01

    Full Text Available This research is to recognise the function of Building Information Modelling (BIM in design optimization for irregular shaped buildings. The study focuses on a conceptual irregular shaped “twisted” building design similar to some existing sculpture-like architectures. Form and function are the two most important aspects of new buildings, which are becoming more sophisticated as parts of equally sophisticated “systems” that we are living in. Nowadays, it is common to have irregular shaped or sculpture-like buildings which are very different when compared to regular buildings. Construction industry stakeholders are facing stiff challenges in many aspects such as buildability, cost effectiveness, delivery time and facility management when dealing with irregular shaped building projects. Building Information Modelling (BIM is being utilized to enable architects, engineers and constructors to gain improved visualization for irregular shaped buildings; this has a purpose of identifying critical issues before initiating physical construction work. In this study, three variations of design options differing in rotating angle: 30 degrees, 60 degrees and 90 degrees are created to conduct quantifiable comparisons. Discussions are focused on three major aspects including structural planning, usable building space, and structural constructability. This research concludes that Building Information Modelling is instrumental in facilitating design optimization for irregular shaped building. In the process of comparing different design variations, instead of just giving “yes or no” type of response, stakeholders can now easily visualize, evaluate and decide to achieve the right balance based on their own criteria. Therefore, construction project stakeholders are empowered with superior evaluation and decision making capability.

  11. Investigation of the temperature gradient instability as the source of midlatitude quiet time decameter-scale ionospheric irregularities: 2. Linear analysis

    Science.gov (United States)

    Eltrass, A.; Mahmoudian, A.; Scales, W. A.; de Larquier, S.; Ruohoniemi, J. M.; Baker, J. B. H.; Greenwald, R. A.; Erickson, P. J.

    2014-06-01

    Previous joint measurements by the Millstone Hill incoherent scatter radar and the Super Dual Auroral Radar Network (SuperDARN) HF radar located at Wallops Island, Virginia, have identified the presence of opposed meridional electron density and temperature gradients in the region of decameter-scale electron density irregularities that have been proposed to be responsible for low-velocity Sub-Auroral Ionospheric Scatter observed by SuperDARN radars. The temperature gradient instability (TGI) and the gradient drift instability (GDI) have been extended into the kinetic regime appropriate for SuperDARN radar frequencies and investigated as the causes of these irregularities. A time series for the growth rate of both TGI and GDI has been developed for midlatitude ionospheric irregularities observed by SuperDARN Greenwald et al. (2006). The time series is computed for both perpendicular and meridional density and temperature gradients. This growth rate comparison shows that the TGI is the most likely generation mechanism for the irregularities observed during the experiment and the GDI is expected to play a relatively minor role in irregularity generation.

  12. Characterizing spontaneous irregular behavior in coupled map lattices

    Energy Technology Data Exchange (ETDEWEB)

    Dobyns, York [PEAR, Princeton University Princeton, NJ 08544-5263 (United States); Atmanspacher, Harald [Institut fuer Grenzgebiete der Psychologie und Psychohygiene Wilhelmstrasse 3a, Freiburg 79098 (Germany)]. E-mail: haa@igpp.de

    2005-04-01

    Two-dimensional coupled map lattices display, in a specific parameter range, a stable phase (quasi-) periodic in both space and time. With small changes to the model parameters, this stable phase develops spontaneous eruptions of non-periodic behavior. Although this behavior itself appears irregular, it can be characterized in a systematic fashion. In particular, parameter-independent features of the spontaneous eruptions may allow useful empirical characterizations of other phenomena that are intrinsically hard to predict and reproduce. Specific features of the distributions of lifetimes and emergence rates of irregular states display such parameter-independent properties.

  13. Two media method for linear attenuation coefficient determination of irregular soil samples; Metodo dos dois meios para a determinacao do coeficiente de atenuacao linear de amostras irregulares de solos

    Energy Technology Data Exchange (ETDEWEB)

    Vici, Carlos Henrique Georges

    2004-07-01

    In several situations of nuclear applications, the knowledge of gamma-ray linear attenuation coefficient for irregular samples is necessary, such as in soil physics and geology. This work presents the validation of a methodology for the determination of the linear attenuation coefficient ({mu}) of irregular shape samples, in such a way that it is not necessary to know the thickness of the considered sample. With this methodology irregular soil samples (undeformed field samples) from Londrina region, north of Parana were studied. It was employed the two media method for the {mu} determination. It consists of the {mu} determination through the measurement of a gamma-ray beam attenuation by the sample sequentially immersed in two different media, with known and appropriately chosen attenuation coefficients. For comparison, the theoretical value of {mu} was calculated by the product of the mass attenuation coefficient, obtained by the WinXcom code, and the measured value of the density sample. This software employs the chemical composition of the samples and supplies a table of the mass attenuation coefficients versus the photon energy. To verify the validity of the two media method, compared with the simple gamma ray transmission method, regular pome stone samples were used. With these results for the attenuation coefficients and their respective deviations, it was possible to compare the two methods. In this way we concluded that the two media method is a good tool for the determination of the linear attenuation coefficient of irregular materials, particularly in the study of soils samples. (author)

  14. HIGH-PERFORMANCE SIMPLE-ENCODING GENERATOR-BASED SYSTEMATIC IRREGULAR LDPC CODES AND RESULTED PRODUCT CODES

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Low-Density Parity-Check (LDPC) code is one of the most exciting topics among the coding theory community. It is of great importance in both theory and practical communications over noisy channels. The most advantage of LDPC codes is their relatively lower decoding complexity compared with turbo codes, while the disadvantage is its higher encoding complexity. In this paper, a new approach is first proposed to construct high performance irregular systematic LDPC codes based on sparse generator matrix, which can significantly reduce the encoding complexity under the same decoding complexity as that of regular or irregular LDPC codes defined by traditional sparse parity-check matrix. Then, the proposed generator-based systematic irregular LDPC codes are adopted ss constituent block codes in rows and columns to design a new kind of product codes family, which also can be interpreted as irregular LDPC codes characterized by graph and thus decoded iteratively. Finally,the performance of the generator-based LDPC codes and the resultant product codes is investigated over an Additive White Gaussian Noise (AWGN) and also compared with the conventional LDPC codes under the same conditions of decoding complexity and channel noise.

  15. Robust Fusion of Irregularly Sampled Data Using Adaptive Normalized Convolution

    NARCIS (Netherlands)

    Pham, T.Q.; Van Vliet, L.J.; Schutte, K.

    2006-01-01

    We present a novel algorithm for image fusion from irregularly sampled data. The method is based on the framework of normalized convolution (NC), in which the local signal is approximated through a projection onto a subspace. The use of polynomial basis functions in this paper makes NC equivalent to

  16. Size and Albedo of Irregular Saturnian Satellites from Spitzer Observations

    NARCIS (Netherlands)

    Mueller, Michael; Grav, T.; Trilling, D.; Stansberry, J.; Sykes, M.

    2008-01-01

    Using MIPS onboard the Spitzer Space Telescope, we observed the thermal emission (24 and, for some targets, 70 um) of eight irregular satellites of Saturn: Albiorix, Siarnaq, Paaliaq, Kiviuq, Ijiraq, Tarvos, Erriapus, and Ymir. We determined the size and albedo of all targets. An analysis of archive

  17. Size and Albedo of Irregular Saturnian Satellites from Spitzer Observations

    NARCIS (Netherlands)

    Mueller, Michael; Grav, T.; Trilling, D.; Stansberry, J.; Sykes, M.

    2008-01-01

    Using MIPS onboard the Spitzer Space Telescope, we observed the thermal emission (24 and, for some targets, 70 um) of eight irregular satellites of Saturn: Albiorix, Siarnaq, Paaliaq, Kiviuq, Ijiraq, Tarvos, Erriapus, and Ymir. We determined the size and albedo of all targets. An analysis of archive

  18. Size and Albedo of Irregular Saturnian Satellites from Spitzer Observations

    NARCIS (Netherlands)

    Mueller, Michael; Grav, T.; Trilling, D.; Stansberry, J.; Sykes, M.

    2008-01-01

    Using MIPS onboard the Spitzer Space Telescope, we observed the thermal emission (24 and, for some targets, 70 um) of eight irregular satellites of Saturn: Albiorix, Siarnaq, Paaliaq, Kiviuq, Ijiraq, Tarvos, Erriapus, and Ymir. We determined the size and albedo of all targets. An analysis of

  19. Structure Irregularity Impedes Drop Roll-Off at Superhydrophobic Surfaces

    DEFF Research Database (Denmark)

    Larsen, Simon Tylsgaard; Andersen, Nis Korsgaard; Søgaard, Emil

    2014-01-01

    We study water drop roll-off at superhydrophobic surfaces with different surface patterns. Superhydrophobic microcavity surfaces were fabricated in silicon and coated with 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS). For the more irregular surface patterns, the observed increase in roll...

  20. Modelling of Ionospheric Irregularities and Total Electron Content.

    Science.gov (United States)

    1983-12-01

    heating and their Isle stital filtering effet fteAeioatnao aa effects on transitinospherte propagation. Pro,’dnso ips~ obse-vations of the temporal...irregularities at different heights. Radio Phys. Quantum Electron-. Lngl. Transl.. 20. 1246. 1977. S) tfttu-uatiolis. It serrs . ho%&ever thait ;to outer

  1. Predictions of Stellar Occultations by Irregular Satellites up to 2020

    Science.gov (United States)

    Ramos Gomes, Altair; Assafin, Marcelo; Beauvalet, Laurene; Desmars, Josselin; Vieira-Martins, Roberto; Camargo, Julio I.; Morgado, Bruno Eduardo; Braga Ribas, Felipe

    2017-06-01

    Due to their orbital configurations, it is believed the irregular satellites of the Giant Planets were captured by their host planets during the Solar System evolution. It is important to know their physical parameters such as size, shape, albedo and composition in an attempt to access their origin. The best ground-based technique to do so is by stellar occultations.With the release of the GAIA catalog and the publication of a large database of positions of irregular satellites (Gomes-Júnior et al., 2015), the position of the stars and the ephemeris of the satellites are improved to better predict stellar occultation.The present work predicts such events for the 8 largest irregular satellites of Jupiter and the largest irregular satellite of Saturn, Phoebe, up to 2020. Another motivation is the passage of Jupiter in front of the Galatic Plane in 2019-2020 increasing a lot the number of stars to be occulted. The same happens with Saturn in 2018.

  2. An Analysis of the Incidence of Recruiter Irregularities

    Science.gov (United States)

    2010-01-01

    provided data and answered our questions about the incidence of recruiter irregularities. The people are Ted Disney at the U.S. Army Recruiting...are more likely to ultimately be substantiated. The Army and the Navy, in contrast, have fairly expansive inter- nal reporting requirements that

  3. Active Absorption of Irregular Gravity Waves in BEM-Models

    DEFF Research Database (Denmark)

    Brorsen, Michael; Frigaard, Peter

    1992-01-01

    The boundary element method is applied to the computation of irregular gravity waves. The boundary conditions at the open boundaries are obtained by a digital filtering technique, where the surface elevations in front of the open boundary are filtered numerically yielding the velocity...

  4. Wheel-rail interaction at short-wave irregularities

    NARCIS (Netherlands)

    Steenbergen, M.J.M.M.

    2008-01-01

    Short-wave irregularities in the wheel-rail interface are at the basis of track and vehicle damage and deterioration. On the short term, they result into high dynamic train-track interaction forces and a high energy input into the system that must be dissipated in the different system components or

  5. 50 KPC radio trails behind irregular galaxies in A1367

    Science.gov (United States)

    Gavazzi, G.; Jaffe, W.

    1987-11-01

    The authors report the discovery of exceptionally bright and extended trails of radio emission behind three irregular galaxies in the periphery of the cluster A 1367, in the Coma Supercluster. Turbulent interaction with the intergalactic medium or a past catastrophic collision between galaxies could have produced the observed phenomenon.

  6. Modeling irregularly spaced residual series as a continuous stochastic process

    NARCIS (Netherlands)

    Von Asmuth, J.R.; Bierkens, M.F.P.

    2005-01-01

    In this paper, the background and functioning of a simple but effective continuous time approach for modeling irregularly spaced residual series is presented. The basic equations were published earlier by von Asmuth et al. (2002), who used them as part of a continuous time transfer function noise mo

  7. Robust Fusion of Irregularly Sampled Data Using Adaptive Normalized Convolution

    NARCIS (Netherlands)

    Pham, T.Q.; Vliet, L.J. van; Schutte, K.

    2006-01-01

    We present a novel algorithm for image fusion from irregularly sampled data. The method is based on the framework of normalized convolution (NC), in which the local signal is approximated through a projection onto a subspace. The use of polynomial basis functions in this paper makes NC equivalent to

  8. Active Absorption Wave Maker System for Irregular Waves

    Institute of Scientific and Technical Information of China (English)

    柳淑学; 王先涛; 李木国; 郭美谊

    2003-01-01

    The key problem in physical model tests with highly reflective structures is to prevent the multiple reflections between the reflective structures and the wave maker. An active absorption wave maker system is described and the representative frequency method for irregular waves is proposed in this paper. Physical model tests are conducted to verify the effectiveness of the proposed method.

  9. Comparison of correlation analysis techniques for irregularly sampled time series

    Directory of Open Access Journals (Sweden)

    K. Rehfeld

    2011-06-01

    Full Text Available Geoscientific measurements often provide time series with irregular time sampling, requiring either data reconstruction (interpolation or sophisticated methods to handle irregular sampling. We compare the linear interpolation technique and different approaches for analyzing the correlation functions and persistence of irregularly sampled time series, as Lomb-Scargle Fourier transformation and kernel-based methods. In a thorough benchmark test we investigate the performance of these techniques.

    All methods have comparable root mean square errors (RMSEs for low skewness of the inter-observation time distribution. For high skewness, very irregular data, interpolation bias and RMSE increase strongly. We find a 40 % lower RMSE for the lag-1 autocorrelation function (ACF for the Gaussian kernel method vs. the linear interpolation scheme,in the analysis of highly irregular time series. For the cross correlation function (CCF the RMSE is then lower by 60 %. The application of the Lomb-Scargle technique gave results comparable to the kernel methods for the univariate, but poorer results in the bivariate case. Especially the high-frequency components of the signal, where classical methods show a strong bias in ACF and CCF magnitude, are preserved when using the kernel methods.

    We illustrate the performances of interpolation vs. Gaussian kernel method by applying both to paleo-data from four locations, reflecting late Holocene Asian monsoon variability as derived from speleothem δ18O measurements. Cross correlation results are similar for both methods, which we attribute to the long time scales of the common variability. The persistence time (memory is strongly overestimated when using the standard, interpolation-based, approach. Hence, the Gaussian kernel is a reliable and more robust estimator with significant advantages compared to other techniques and suitable for large scale application to paleo-data.

  10. How Is Aplastic Anemia Diagnosed?

    Science.gov (United States)

    ... from the NHLBI on Twitter. How Is Aplastic Anemia Diagnosed? Your doctor will diagnose aplastic anemia based on your medical and family histories, a ... your primary care doctor thinks you have aplastic anemia, he or she may refer you to a ...

  11. Enhancement of electric and magnetic wave fields at density gradients

    Directory of Open Access Journals (Sweden)

    A. Reiniusson

    2006-03-01

    Full Text Available We use Freja satellite data to investigate irregular small-scale density variations. The observations are made in the auroral region at about 1000-1700 km. The density variations are a few percent, and the structures are found to be spatial down to a scale length of a few ion gyroradii. Irregular density variations are often found in an environment of whistler mode/lower hybrid waves and we show that at the density gradients both the electric and magnetic wave fields are enhanced.

  12. Long-period irregular pulsations under the conditions of a quiet magnetosphere

    Science.gov (United States)

    Kurazhkovskaya, N. A.; Klain, B. I.; Lavrov, I. P.

    2016-05-01

    Simultaneous observations of high-latitude long-period irregular pulsations at frequencies of 2.0-6.0 mHz ( ipcl) and magnetic field disturbances in the solar wind plasma at low geomagnetic activity ( Kp ~ 0) have been studied. The 1-s data on the magnetic field registration at Godhavn (GDH) high-latitude observatory and the 1-min data on the solar wind plasma and IMF parameters for 2011-2013 were used in an analysis. Ipcl (irregular pulsations continuous, long), which were observed against a background of the IMF Bz reorientation from northward to southward, have been analyzed. In this case other solar wind plasma and IMF parameters, such as velocity V, density n, solar wind dynamic pressure P = ρ V 2 (ρ is plasma density), and strength magnitude B, were relatively stable. The effect of the IMF Bz variation rate on the ipcl spectral composition and intensity has been studied. It was established that the ipcl spectral density reaches its maximum (~10-20 min) after IMF Bz sign reversal in a predominant number of cases. It was detected that the ipcl average frequency ( f) is linearly related to the IMF Bz variation rate (Δ Bz/Δ t). It was shown that the dependence of f on Δ Bz/Δ t is controlled by the α = arctan( By/ Bx) angle value responsible for the MHD discontinuity type at the front boundary of magnetosphere. The results made it possible to assume that the formation of the observed ipcl spectrum, which is related to the IMF Bz reorientation, is caused by solar wind plasma turbulence, which promotes the development of current sheet instability and surface wave amplification at the magnetopause.

  13. Study of Equatorial Ionospheric irregularities and Mapping of Electron Density Profiles and Ionograms

    Science.gov (United States)

    2012-03-09

    T. Tudor and V. Manea, “Symmetry between partially polarized light and partial polarizers in the vectorial Pauli algebraic form- alism,” J. Mod. Opt...58, 845–852 (2011). 15. T. Tudor and V. Manea, “Ellipsoid of the polarization degree: a vectorial pure operatorial Pauli algebraic approach,” J. Opt...geometric algebra ) and 3 (Refractive index and energy-momentum of elliptically polarized radio waves in plasma via geometric algebra ). A third paper

  14. Finding Causes of Irregular Headways Integrating Data Mining and AHP

    Directory of Open Access Journals (Sweden)

    Shi An

    2015-11-01

    Full Text Available Irregular headways could reduce the public transit service level heavily. Finding out the exact causes of irregular headways will greatly help to develop efficient strategies aiming to improve transit service quality. This paper utilizes bus GPS data of Harbin to evaluate the headway performance and proposes a statistical method to identify the abnormal headways. Association mining is used to dig deeper and recognize six causes of bus bunching. The AHP, embedded data analysis, is applied to determine the weight of each cause in the case of that these causes are combined with each other constantly. Results show that the front bus has a greater effect on bus bunching than the following bus, and the traffic condition is the most critical factor affecting bus headway.

  15. Irregular Migration - between legal status and social practices

    DEFF Research Database (Denmark)

    Lund Thomsen, Trine

    2012-01-01

    . Language and religious affiliations of an immigrant adolescent in Norway by Haque, Shahzaman View Top 20 Most Downloaded Articles Previous Article Next Article Go to table of contents Download full text pdf (PDF, 425 KB) Irregular Migration – Between Legal Status and Social Practices Narratives of Polish...... labour migration Thomsen, Trine Lund1 1Centre for the Studies of Migration and Diversity (CoMID), Aalborg University, Denmark Citation Information: Nordic Journal of Migration Research. Volume 2, Issue 4, Pages 308–315, ISSN (Online) 1799-649X, ISSN (Print) , DOI: 10.2478/v10202-012-0001-0, December 2012...... Publication History: Published Online: 2012-12-28 Abstract How do Polish migrant workers experience the process of migration and how does irregular migration status influence their life plans? In this article I analyse how the shifts between different legal statuses may be related to the social practices...

  16. Searching for Strange Attractor in Sliver Irregularity Series

    Institute of Scientific and Technical Information of China (English)

    YAO Jie; ZHONG Zai-min; CHEN Ren-zhe; YE Guo-ming

    2007-01-01

    The chaotic nonlinear time series method isapplied to analyze the sliver irregularity in textileprocessing. Because it unifies the system's determinacy andrandonmess, it seems more adaptive to describe the sliverirregularity than conventional methods. Firstly, the chaoscharacter, i. e. fractal dimension, positive Lyapunovexponent, and state space parameters, including time delayand reconstruction dimension, are calculated respectively.As a result, a positive Lyapunov exponent and a fractaldimension are obtained, which demonstrates that the systemis chaotic in fact. Secondly, both local linear forecast andglobal forecast models based on the reconstructed state areadopted to predict a segment part of the sliver irregularityseries, which proves the validity of this analysis.Therefore, the sliver irregularity series shows the evidenceof chaotic phenomena, and thus laying the theoreticalfoundation for analyzing and modeling the sliver irregularityseries by applying the chaos theory, and providing a newway to understand the complexity of the sliver irregularitymuch better.

  17. An analysis of the timing irregularities for 366 pulsars

    CERN Document Server

    Hobbs, G; Kramer, M

    2009-01-01

    We provide an analysis of timing irregularities observed for 366 pulsars. Observations were obtained using the 76-m Lovell radio telescope at the Jodrell Bank Observatory over the past 36 years. These data sets have allowed us to carry out the first large-scale analysis of pulsar timing noise over time scales of > 10yr, with multiple observing frequencies and for a large sample of pulsars. Our sample includes both normal and recycled pulsars. The timing residuals for the pulsars with the smallest characteristic ages are shown to be dominated by the recovery from glitch events, whereas the timing irregularities seen for older pulsars are quasi-periodic. We emphasise that previous models that explained timing residuals as a low-frequency noise process are not consistent with observation.

  18. Constructing C1 Continuous Surface on Irregular Quad Meshes

    Institute of Scientific and Technical Information of China (English)

    HE Jun; GUO Qiang

    2013-01-01

    A new method is proposed for surface construction on irregular quad meshes as extensions to uniform B-spline surfaces. Given a number of control points, which form a regular or irregular quad mesh, a weight function is constructed for each control point. The weight function is defined on a local domain and is C1 continuous. Then the whole surface is constructed by the weighted combination of all the control points. The property of the new method is that the surface is defined by piecewise C1 bi-cubic rational parametric polynomial with each quad face. It is an extension to uniform B-spline surfaces in the sense that its definition is an analogy of the B-spline surface, and it produces a uniform bi-cubic B-spline surface if the control mesh is a regular quad mesh. Examples produced by the new method are also included.

  19. The scholarly rebellion of the early Baker Street Irregulars

    Directory of Open Access Journals (Sweden)

    George Mills

    2017-03-01

    Full Text Available This work provides and analyzes an early institutional history of the pioneering Sherlock Holmes American fan club, the Baker Street Irregulars (BSI. Using the publications and records of these devoted Sherlockians, I track the BSI's development from a speakeasy gathering in 1934 to a national organization by the mid-1940s. This growth was built on a foundation of Victorian nostalgia and playful humor. Yet at the same time the members of the Irregulars took their fandom seriously, producing Sherlockian scholarship and creating an infrastructure of journals, conferences, and credentialing that directly mimicked the academy. They positioned themselves in contrast to prevailing scholarly practices of the period, such as New Criticism. I trace both how their fan practices developed over time and how this conflict with the academy led to many of the BSI's defining characteristics.

  20. Visual nesting system for irregular cutting-stock problem based on rubber band packing algorithm

    Directory of Open Access Journals (Sweden)

    Xiaoping Liao

    2016-05-01

    Full Text Available This article deals with the packing problem of irregular items allocated into a rectangular sheet to minimize the waste. Conventional solution is not visual during the packing process. It obtains a reasonable and relatively satisfactory solution between the nesting time and nesting solution. This article adopts a physical method that uses rubber band packing algorithm to simulate a rubber band wrapping those packing irregular items. The simulation shows a visual and fast packing process. The resultant rubber band force is applied in the packing items to translate, rotate, and slide them to make the area decrease and obtain a high packing density. An improved analogy QuickHull algorithm is presented to obtain extreme points of rubber band convex hull. An adaptive module could set a variable rubber band force and a variable time step to make a proper convergence and no intersection. A quick convex decomposition method is used to solve the problem of concave polygon. A plural vector expression approach is adopted to calculate the resultant vector of the rubber band force. Several cases are compared with the benchmark problems to prove rubber band packing algorithm performance.

  1. LITTLE THINGS in 3D: robust determination of the circular velocity of dwarf irregular galaxies

    CERN Document Server

    Iorio, Giuliano; Nipoti, Carlo; Di Teodoro, Enrico; Read, Justin I; Battaglia, Giuseppina

    2016-01-01

    Dwarf Irregular galaxies (dIrrs) are the smallest stellar systems with extended HI discs. The study of the kinematics of such discs is a powerful tool to estimate the total matter distribution at these very small scales. In this work, we study the HI kinematics of 17 galaxies extracted from the `Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey' (LITTLE THINGS). Our approach differs significantly from previous studies in that we directly fit 3D models (two spatial dimensions plus one spectral dimension) using the software $^\\text{3D}$BAROLO, fully exploiting the information in the HI datacubes. For each galaxy we derive the geometric parameters of the HI disc (inclination and position angle), the radial distribution of the surface density, the velocity-dispersion ($\\sigma_v$) profile and the rotation curve. The circular velocity (V$_{\\text{c}}$), which traces directly the galactic potential, is then obtained by correcting the rotation curve for the asymmetric drift. As an initial ap...

  2. Deep Near-Infrared Surface Photometry and Properties of Local Volume Dwarf Irregular Galaxies

    CERN Document Server

    Young, T; López-Sánchez, Á R; Koribalski, B S

    2014-01-01

    We present deep H-band surface photometry and analysis of 40 Local Volume galaxies, a sample primarily composed of dwarf irregulars in the Cen A group, obtained using the IRIS2 detector at the 3.9m Anglo-Australian Telescope. We probe to a surface brightness of ~25 mag arcsec$^{-2}$, reaching a 40 times lower stellar density than the Two Micron All Sky Survey (2MASS). Employing extremely careful and rigorous cleaning techniques to remove contaminating sources, we perform surface photometry on 33 detected galaxies deriving the observed total magnitude, effective surface brightness and best fitting S\\'ersic parameters. We make image quality and surface photometry comparisons to 2MASS and VISTA Hemispheric Survey (VHS) demonstrating that deep targeted surveys are still the most reliable means of obtaining accurate surface photometry. We investigate the B-H colours with respect to mass for Local Volume galaxies, finding that the colours of dwarf irregulars are significantly varied, eliminating the possibility of ...

  3. An Amino Acid Code for Irregular and Mixed Protein Packing

    Science.gov (United States)

    Joo, Hyun; Chavan, Archana; Fraga, Keith; Tsai, Jerry

    2015-01-01

    To advance our understanding of protein tertiary structure, the development of the knob-socket model is completed in an analysis of the packing in irregular coil and turn secondary structure packing as well as between mixed secondary structure. The knob-socket model simplifies packing based on repeated patterns of 2 motifs: a 3 residue socket for packing within 2° structure and a 4 residue knob-socket for 3° packing. For coil and turn secondary structure, knob-sockets allow identification of a correlation between amino acid composition and tertiary arrangements in space. Coil contributes almost as much as α-helices to tertiary packing. Irregular secondary structure involves 3 residue cliques of consecutive contacting residues or XYZ sockets. In irregular sockets, Gly, Pro, Asp and Ser are favored, while Cys, His, Met and Trp are not. For irregular knobs, the preference order is Arg, Asp, Pro, Asn, Thr, Leu, and Gly, while Cys, His, Met and Trp are not. In mixed packing, the knob amino acid preferences are a function of the socket that they are packing into, whereas the amino acid composition of the sockets does not depend on the secondary structure of the knob. A unique motif of a coil knob with an XYZ β-sheet socket may potentially function to inhibit β-sheet extension. In addition, analysis of the preferred crossing angles for strands within a β-sheet and mixed α-helices/β-sheets identifies canonical packing patterns useful in protein design. Lastly, the knob-socket model abstracts the complexity of protein tertiary structure into an intuitive packing surface topology map. PMID:26370334

  4. Using Little's Irregularity Index in orthodontics: outdated and inaccurate?

    LENUS (Irish Health Repository)

    Macauley, Donal

    2012-12-01

    Little\\'s Irregularity Index (LII) was devised to objectively score mandibular incisor alignment for epidemiological studies but has been extended to assess the relative performance of orthodontic brackets, retainer or treatment modalities. Our aim was to examine the repeatability and precision of LII measurements of four independent examiners on the maxillary arch of orthodontic patients. The hypothesis was that the reproducibility of individual contact point displacement measurements, used to calculate the LII score, are inappropriate.

  5. New Secular Resonances Involving the Irregular Satellies of Saturn

    Science.gov (United States)

    Cuk, M.; Burns, J. A.; Carruba, V.; Nicholson, P. D.; Jacobson, R. A.

    2002-09-01

    We report that some of the recently found irregular satellites of Saturn, and possibly Uranus, dwell in hitherto unobserved resonances. These include the Kozai resonance, previously postulated but never before found in our Solar System. We also describe a new type of secular resonance for irregular satellites at higher inclinations (40-45o ), which locks the satellite's pericenter with that of the planet. Comparing theoretical predictions (Carruba et al. 2002)with the orbits of those Saturnian irregulars having inclinations around 45o , we found that Saturn's 2000_S5 and 2000_S6 have extremely slow motions of their arguments of pericenter, and their pericenters are presently almost 90 degrees away from their nodes (Jacobson 2001). Longitude of pericenter of another prograde satellite of Saturn, 2000_S3, precesses extremely slowly (Jacobson 2001). We simulated the motion of a clone of 2000_S3 and found that its longitude of pericenter could be librating around that of Saturn, with a very long period (on the order of 30,000 years) and large amplitude (120o ). The nature of this resonance appears different from one affecting certain Jovian moons (Saha and Tremaine 1993). If the amplitude of pericenter librations can be that large, another Saturnian irregular, 2000_S2, could be in a similar resonance. The Uranian retrograde satellites Stephano and Caliban (at inclinations of about 140o ) also have ϖ's that precess very slowly and are roughly aligned with Uranus's (Jacobson 2000). We are currently examining their motion to see if they are also in a resonance similar to that seen at 2000_S3.

  6. Multicolor Photometry of the Uranus Irregular Satellites Sycorax and Caliban

    CERN Document Server

    Maris, M; Cremonese, G; Fulle, M; Maris, Michele; Carraro, Giovanni; Cremonese, Gabriele; Fulle, Marco

    2001-01-01

    We report on accurate BVRI photometry for the two Uranus irregular satellites Sycorax and Caliban. We derive colours, showing that Sycorax is bluer than Caliban. Our data allows us to detect a significant variability in the Caliban's light-curve, which suggests an estimated period of about 3 hours. Despite it is the brighter of the two bodies, Sycorax does not display a strong statistically significant variability. However our data seem to suggest a period of about 4 hours

  7. Generalizing Lifted Tensor-Product Wavelets to Irregular Polygonal Domains

    Energy Technology Data Exchange (ETDEWEB)

    Bertram, M.; Duchaineau, M.A.; Hamann, B.; Joy, K.I.

    2002-04-11

    We present a new construction approach for symmetric lifted B-spline wavelets on irregular polygonal control meshes defining two-manifold topologies. Polygonal control meshes are recursively refined by stationary subdivision rules and converge to piecewise polynomial limit surfaces. At every subdivision level, our wavelet transforms provide an efficient way to add geometric details that are expanded from wavelet coefficients. Both wavelet decomposition and reconstruction operations are based on local lifting steps and have linear-time complexity.

  8. Irregular and adaptive sampling for automatic geophysic measure systems

    Science.gov (United States)

    Avagnina, Davide; Lo Presti, Letizia; Mulassano, Paolo

    2000-07-01

    In this paper a sampling method, based on an irregular and adaptive strategy, is described. It can be used as automatic guide for rovers designed to explore terrestrial and planetary environments. Starting from the hypothesis that a explorative vehicle is equipped with a payload able to acquire measurements of interesting quantities, the method is able to detect objects of interest from measured points and to realize an adaptive sampling, while badly describing the not interesting background.

  9. Dynamics of landslides on comets of irregular shape

    Science.gov (United States)

    Czechowski, Leszek

    2017-04-01

    Landslides were observed on a few comet's nuclei, e.g. [1], [2]. The mechanism of their origin is not obvious because of very low gravity. According to [2] fluidization and multiphase transport of cometary material could be an explanation. We investigate here motion of the mass on a comet of irregular shape. The mechanism responsible for the low friction is not considered here. In fact, mass motion often occurs without contact with the surface. The motion could be triggered by meteoroids impacts or by the tidal forces. Comets nuclei are believed to be built of soft materials like snow and dust. The landing of Philae on the comet 67P/Czuriumow-Gierasimienko indicates a different situation. According to [1]: "thermal probe did not fully penetrate the near-surface layers, suggesting a local resistance of the ground to penetration of >4 megapascals, equivalent to >2 megapascal uniaxial compressive strength". Here we assume that elastic properties of comet's nuclei could be similar to elastic properties of dry snow, namely Young modulus is assumed to be 1 - 100 MPa, see [3] and [4]. We consider nucleus of the shape of 67P/Churyumov-Gerasimenko with density 470 kg/m3. The impact or tidal forces result in changing of rotation of the comet. In general, the vector of angular velocity will be a subject to nutation that results in changing of centrifugal force, and consequently could be a factor triggering landslides. Note that nucleus' shape does not resemble the shape of surface of constant value of gravitational potential (i.e. 'geoid'). Our numerical models indicate the parts of the nucleus where landslides start and other parts where landslides stop. Of course, the regolith from the first type of regions would be removed to the regions of the second class. The motion of the mass is often complicated because of complicated distribution of the gravity and complicated shape of the nucleus. Acknowledgement: The research is partly supported by Polish National Science Centre

  10. Photometry of Irregular Satellites of Uranus and Neptune

    Science.gov (United States)

    Grav, Tommy; Holman, Matthew J.; Fraser, Wesley C.

    2004-09-01

    We present BVR photometric colors of six Uranian and two Neptunian irregular satellites, collected using the Magellan Observatory (Las Campanas, Chile) and the Keck Observatory (Manua Kea, Hawaii). The colors range from neutral to light red, and like the Jovian and the Saturnian irregular satellites (Grav et al.) there is an apparent lack of the extremely red objects found among the Centaurs and Kuiper Belt objects. The Uranian irregular satellites can be divided into three possible dynamical families, but the colors collected show that two of these dynamical families, the Caliban and Sycorax clusters, have heterogeneous colors. Of the third possible family, the 168° cluster containing two objects with similar average inclinations but quite different average semimajor axes, only one object (U XXI Trinculo) was observed. The heterogeneous colors and the large dispersion of the average orbital elements lead us to doubt that they are collisional families. We favor single captures as a more likely scenario. The two Neptunian satellites observed (N II Nereid and S/2002 N1) both have very similar neutral, Sun-like colors. Together with the high collisional probability between these two objects over the age of the solar system (Nesvorný et al.; Holman et al.), this suggests that S/2002 N1 is a fragment of Nereid, broken loose during a collision or cratering event with an undetermined impactor.

  11. Flow induced vibrations in arrays of irregularly spaced cylinders

    Science.gov (United States)

    Taub, Gordon; Michelin, Sébastien

    2014-11-01

    Historically the main industrial applications of cylinder arrays in cross flows favored regular arrangements of cylinders. For this reason, most past studies of Flow Induced Vibrations (FIV) in large cylinder arrays have focused on such arrangements. Recently there has been some interest in generating renewable energy using FIV of bluff bodies. In such applications it will likely be beneficial to enhance, rather than suppress FIV. It is not known a priori if regular or irregularly spaced arrays are most adequate for this type of application. In this study, wind tunnel experiments were conducted on one regularly spaced array and four different irregularly spaced arrays of cylinders in a cross flow. Each arrangement of cylinders was examined under eight different orientations to a cross flow ranging between 10 m/s and 17 m/s. The average amplitude of vibration of the cylinders was found to highly depend on arrangement and orientation. The typical amplitude of vibration of the rods in the irregular arrangements were found to be an order of magnitude larger than that of the regular array. A simple model was proposed in order to predict if a given arrangement was likely to produce large oscillations, and the validity of the model was examined. This research was supported by a Marie Curie International Reintegration Grant within the 7th European Community Framework Program (Grant PIRG08-GA-2010-276762).

  12. Histogram Planimetry Method for the Measurement of Irregular Wounds.

    Science.gov (United States)

    Yesiloglu, Nebil; Yildiz, Kemalettin; Cem Akpinar, Ali; Gorgulu, Tahsin; Sirinoglu, Hakan; Ozcan, Arzu

    2016-09-01

    Irregularly shaped wounds or flap borders usually require specified software or devices to measure their area and follow-up wound healing. In this study, an easy way of area measurement called histogram planimetry (HP) for wounds with irregular geometric shapes is defined and compared to conventional millimetric wound measurement. Ten irregularly bordered geometric shapes were measured by 4 different individuals working as surgical assistants using both HP and manual millimetric measurement tools. The amount of time for each wound shape calculation as well as the measurements of the wound areas were noted. All measurements were compared for each method and between each individual using the Wilcoxon signed-rank test. There was no statistically significant difference between 2 measurement methods by means of measured areas; however, measurement time was significantly lower when the HP method was used. There also was no significant difference between the individuals' measurements and calculation times. These results indicated that HP is useful as a conventional millimetric square wound measurement technique with significantly lower measurement times. Due to the development of photo-editor software technologies, measurements in the surgical field have become more accurate and rapid than conventional manual methods without consuming the time and energy needed for other studies. A future study including comparisons between the presented method and complex computerized measurement methods, in terms of duration and accuracy, may provide additional supportive data for the authors' method.

  13. How to diagnose cardiac tamponade

    NARCIS (Netherlands)

    van Steijn, JHM; Sleijfer, DT; van der Graaf, WTA; van der Sluis, A; Nieboer, P

    2002-01-01

    Malignant pericardial effusion is a potentially fatal complication of malignancy unless recognised and treated promptly. Patients with this condition are often difficult to diagnose. Physical examination, chest radiography and electrocardiography have poor diagnostic values in identification of pati

  14. How Is Stomach Cancer Diagnosed?

    Science.gov (United States)

    ... Cancer Early Detection, Diagnosis, and Staging How Is Stomach Cancer Diagnosed? Stomach cancers are usually found when ... Ask Your Doctor About Stomach Cancer? More In Stomach Cancer About Stomach Cancer Causes, Risk Factors, and ...

  15. How Is Marfan Syndrome Diagnosed?

    Science.gov (United States)

    ... common in many people. Doctors use a scoring system based on the number and type of Ghent criteria present to diagnose Marfan syndrome. Talk ... National Institutes of Health Department of Health and Human Services USA.gov

  16. How Is Thyroid Cancer Diagnosed?

    Science.gov (United States)

    ... Cancer Early Detection, Diagnosis, and Staging Tests for Thyroid Cancer Thyroid cancer may be diagnosed after a person ... Health Care Team About Thyroid Cancer? More In Thyroid Cancer About Thyroid Cancer Causes, Risk Factors, and Prevention ...

  17. How Is Ovarian Cancer Diagnosed?

    Science.gov (United States)

    ... Cancer Early Detection, Diagnosis, and Staging How Is Ovarian Cancer Diagnosed? If you have symptoms of ovarian cancer ... Ask Your Doctor About Ovarian Cancer? More In Ovarian Cancer About Ovarian Cancer Causes, Risk Factors, and Prevention ...

  18. How to diagnose cardiac tamponade

    NARCIS (Netherlands)

    van Steijn, JHM; Sleijfer, DT; van der Graaf, WTA; van der Sluis, A; Nieboer, P

    Malignant pericardial effusion is a potentially fatal complication of malignancy unless recognised and treated promptly. Patients with this condition are often difficult to diagnose. Physical examination, chest radiography and electrocardiography have poor diagnostic values in identification of

  19. Using a Calculated Pulse Rate with an Artificial Neural Network to Detect Irregular Interbeats.

    Science.gov (United States)

    Yeh, Bih-Chyun; Lin, Wen-Piao

    2016-03-01

    Heart rate is an important clinical measure that is often used in pathological diagnosis and prognosis. Valid detection of irregular heartbeats is crucial in the clinical practice. We propose an artificial neural network using the calculated pulse rate to detect irregular interbeats. The proposed system measures the calculated pulse rate to determine an "irregular interbeat on" or "irregular interbeat off" event. If an irregular interbeat is detected, the proposed system produces a danger warning, which is helpful for clinicians. If a non-irregular interbeat is detected, the proposed system displays the calculated pulse rate. We include a flow chart of the proposed software. In an experiment, we measure the calculated pulse rates and achieve an error percentage of pulse rates to detect irregular interbeats, we find such irregular interbeats in eight participants.

  20. Transnational activities and aspirations of irregular migrants in Belgium and the Netherlands

    NARCIS (Netherlands)

    M.J. van Meeteren (Masja)

    2012-01-01

    textabstractThe literature on immigrant transnationalism and on irregular immigration suggests irregular migrants engage relatively little in transnational activities because of the obstacles associated with their legal and economic statuses. Drawing on participant observation and in-depth interview

  1. Shadow Places: Patterns of Spatial Concentration and Incorporation of Irregular Immigrants in the Netherlands

    NARCIS (Netherlands)

    A.S. Leerkes (Arjen); G.B.M. Engbersen (Godfried); M.R.P.J.R.S. van San (Marion)

    2007-01-01

    textabstractSummary: In Western countries, irregular immigrants constitute a sizeable segment of the population. By combining quantitative and qualitative research methods, this article describes and explains irregular immigrants’ patterns of spatial concentration and incorporation in the Netherland

  2. Counting forbidden patterns in irregularly sampled time series. II. Reliability in the presence of highly irregular sampling

    Science.gov (United States)

    Sakellariou, Konstantinos; McCullough, Michael; Stemler, Thomas; Small, Michael

    2016-12-01

    We are motivated by real-world data that exhibit severe sampling irregularities such as geological or paleoclimate measurements. Counting forbidden patterns has been shown to be a powerful tool towards the detection of determinism in noisy time series. They constitute a set of ordinal symbolic patterns that cannot be realised in time series generated by deterministic systems. The reliability of the estimator of the relative count of forbidden patterns from irregularly sampled data has been explored in two recent studies. In this paper, we explore highly irregular sampling frequency schemes. Using numerically generated data, we examine the reliability of the estimator when the sampling period has been drawn from exponential, Pareto and Gamma distributions of varying skewness. Our investigations demonstrate that some statistical properties of the sampling distribution are useful heuristics for assessing the estimator's reliability. We find that sampling in the presence of large chronological gaps can still yield relatively accurate estimates as long as the time series contains sufficiently many densely sampled areas. Furthermore, we show that the reliability of the estimator of forbidden patterns is poor when there is a high number of sampling intervals, which are larger than a typical correlation time of the underlying system.

  3. 高速磁浮轨道不平顺测试及分析%Measurements and analysis of track irregularities on high speed maglev lines

    Institute of Scientific and Technical Information of China (English)

    Jin SHI; Wen-shan FANG; Ying-jie WANG; Yang ZHAO

    2014-01-01

    Track irregularities have an obvious effect on the running stability and ride quality of maglev trains traveling at high speeds. We developed a measurement principle and data processing method which were applied to the high speed maglev line operating. The method, which includes partial filtering, integration, resampling of signal, and a low pass Butterworth filter, was used to calculate the irregularities of the maglev line. The spectra of the sample space were evaluated. A 7-parameter power spectrum density (PSD) function of line irregularities was fitted, based on the measured data. Analysis of the results showed that the maglev stator plane irregularities were better than conventional railway vertical rail irregularities when the wavelength was 5-100 m, and worse when the wavelength was 1-5 m. The PSD of maglev guidance plane irregularities was similar to that of cross level GRSHL (German railway spectra of high irregularity) when the wavelength was 10-100 m. The irregularities were clearly worse than cross level rail irregularities in a conventional railway when the wavelength was 1-10 m. This suggests that short-wavelength track irregularities of a maglev line caused by deviation and inclination of the stator plane should be minimized by strictly controlling the machining error of functional components during construction and maintenance.%研究目的:提出高速磁浮轨道不平顺处理方法,分析不平顺特征,拟合形成轨道谱,为线路空间维护提供参考。  创新要点:实现了对高速磁浮轨道不平顺的提取,确定了轨道谱参数。  研究方法:基于惯性基准法,运用数字信号处理方法实现对轨道不平顺的提取,采用最小二乘法拟合得到定子面和导向面七参数轨道谱。  重要结论:定子面和导向面分别在5-100 m和10-100 m波长范围内平顺性状态较好,由功能件安装等引起的1-5 m和1-10 m波长范围内的偏差应严格控制。

  4. C/NOFS observations of intermediate and transitional scale-size equatorial spread F irregularities

    Science.gov (United States)

    Rodrigues, F. S.; Kelley, M. C.; Roddy, P. A.; Hunton, D. E.; Pfaff, R. F.; de La Beaujardière, O.; Bust, G. S.

    We present initial results of the analysis of high sampling rate (512 Hz) measurements made by the Planar Langmuir Probe (PLP) instrument and the Vector Electric Field Instrument (VEFI) onboard the Communication/Navigation Outage Forecasting System (C/NOFS) satellite. This letter focuses on the analysis of irregularities with scale-sizes in the intermediate (0.1-10 km) and transitional (10-100 m) domains observed when the satellite was flying through a large equatorial spread F (ESF) depletion on the night of October 9-10, 2008 over South America. The results presented in this letter suggest the operation of a diffusive subrange in the density power spectra and the possibility of an inertial plasma regime being observed at relatively low altitudes as a result of the long-lasting solar minimum conditions.

  5. Irregular Liesegang-type patterns in gas phase revisited. II. Statistical correlation analysis

    Science.gov (United States)

    Torres-Guzmán, José C.; Martínez-Mekler, Gustavo; Müller, Markus F.

    2016-05-01

    We present a statistical analysis of Liesegang-type patterns formed in a gaseous HCl-NH3 system by ammonium chloride precipitation along glass tubes, as described in Paper I [J. C. Torres-Guzmán et al., J. Chem. Phys. 144, 174701 (2016)] of this work. We focus on the detection and characterization of short and long-range correlations within the non-stationary sequence of apparently irregular precipitation bands. To this end we applied several techniques to estimate spatial correlations stemming from different fields, namely, linear auto-correlation via the power spectral density, detrended fluctuation analysis (DFA), and methods developed in the context of random matrix theory (RMT). In particular RMT methods disclose well pronounced long-range correlations over at least 40 bands in terms of both, band positions and intensity values. By using a variant of the DFA we furnish proof of the nonlinear nature of the detected long-range correlations.

  6. Effect of irregularity on torsional surface waves in an initially stressed anisotropic porous layer sandwiched between homogeneous and non-homogeneous half-space

    Indian Academy of Sciences (India)

    Anup Saha; Santimoy Kundu; Shishir Gupta; Pramod Kumar Vaishnav

    2016-06-01

    The present paper is concerned with the propagation of torsional surface waves in an initially stressedanisotropic porous layer sandwiched between homogeneous and non-homogeneous half-space. We assumethe quadratic inhomogeneity in rigidity and density in the lower half-space and irregularity is taken inthe form of rectangle at the interface separating the layer from the lower half-space. The dispersionequation for torsional waves has been obtained in a closed form. Velocity equation is also obtained inthe absence of irregularity. The study reveals that the presence of irregularity, initial stress, porosity,inhomogeneity and anisotropy factor in the dispersion equation approves the significant effect of theseparameters in the propagation of torsional waves in porous medium. It has also been observed that fora uniform media, the velocity equation reduces to the classical result of Love wave.

  7. Effect of irregularity on torsional surface waves in an initially stressed anisotropic porous layer sandwiched between homogeneous and non-homogeneous half-space

    Science.gov (United States)

    Saha, Anup; Kundu, Santimoy; Gupta, Shishir; Vaishnav, Pramod Kumar

    2016-06-01

    The present paper is concerned with the propagation of torsional surface waves in an initially stressed anisotropic porous layer sandwiched between homogeneous and non-homogeneous half-space. We assume the quadratic inhomogeneity in rigidity and density in the lower half-space and irregularity is taken in the form of rectangle at the interface separating the layer from the lower half-space. The dispersion equation for torsional waves has been obtained in a closed form. Velocity equation is also obtained in the absence of irregularity. The study reveals that the presence of irregularity, initial stress, porosity, inhomogeneity and anisotropy factor in the dispersion equation approves the significant effect of these parameters in the propagation of torsional waves in porous medium. It has also been observed that for a uniform media, the velocity equation reduces to the classical result of Love wave.

  8. Climatology of low latitude F-region irregularities using GPS radio occultation data

    Science.gov (United States)

    Kepkar, Ankur; Arras, Christina; Wickert, Jens

    2017-04-01

    Since the presence of electrons in the upper atmosphere affects radio waves, GNSS signals which operate at radio frequencies result in weak signal strength at reception. Such affected signals can be associated with the Signal-to-Noise (SNR) to study disturbances which are caused by irregularities in the Earth's ionosphere. For this study we use data obtained by the GPS radio occultation method, a satellite-satellite remote sensing technique. The general idea of this method is to track the GPS radio signal, as it passes through the Earth's atmosphere crossing Earth's limb. This weather independent method provides global coverage, high accuracy and a high vertical resolution. Due to the refraction of the GPS electromagnetic waves induced by electron density gradients in ionospheric altitudes, the GPS signals contain information on current ionospheric conditions. The study mainly focuses on providing a climatology of disturbances at low latitude region of the ionosphere taking into account the measurements obtained from FORMOSAT-3/COSMIC (2006-2013). We use GPS L1 profiles tracked in 1Hz mode which scans the Earth's atmosphere with an altitude resolution of 2km. Strong SNR fluctuations are referred to vertical changes in the electron density. The six FORMOSAT-3/COSMIC satellites provide in total about 2,000 radio occultation profiles per day on an average. About 5 millions of profiles were processed for this study, of which 0.16% contain strong disturbances in the ionospheric F-region. We observed that the F-region irregularity phenomenon occurs mainly at night time close to the Earth's magnetic equator during years with high solar activity. Distinctive seasonal variations can be seen from such investigations when analyzed for different years of data. This phenomenon is traditionally explained as a consequence of plasma instability.

  9. Optimización de la distribución de piezas irregulares en chapas // Irregular parts nesting problem optimization.

    Directory of Open Access Journals (Sweden)

    A. M. Lastres - Aleaga

    2010-05-01

    Full Text Available ResumenEn el presente artículo se realiza un estudio de diferentes esquemas de solución reflejados en laliteratura, que tratan el problema de la distribución de piezas irregulares en superficies planas conanidamiento bidimensional (Nesting. Fueron analizados diferentes esquemas de solución, siendolos que consideran la geometría real de la pieza, durante la evaluación y posicionamiento de lasmismas sobre la superficie a cortar, los que garantizan el mayor aprovechamiento del material. Elesquema propuesto se caracteriza por un tratamiento gráfico de las piezas que permite acelerar elproceso de reconocimiento y evaluación de opciones de acoplamiento entre ellas, así como lacreación de poblaciones de conglomerados crecientes para su ubicación definitiva en la superficie acortar. En la generación de poblaciones de opciones de solución, se utiliza un algoritmo derivado delmétodo de Integración de Variables, además se realiza la comparación de los resultados obtenidospor el método propuesto, con otros resultados generados por procedimientos desarrollados pordiferentes autores, alcanzando mejorar los valores de aprovechamiento de material y la reduccióndel tiempo de generación de soluciones.Palabras claves: Distribución de piezas irregulares en superficies; optimización; Métodos Evolutivos;_________________________________________________________________________AbstractIn this article, we study various solution schemes reported in the literature, which deal with theproblem of irregular parts distribution on flat surfaces with two-dimensional nesting. Different solutionschemes were analyzed, which they consider to be the real geometry of the part, during theevaluation and positioning them on the surface to be cut, ensuring the best use of the material. Theproposed scheme is characterized by a graphic treatment of the pieces that can accelerate theprocess of recognition and evaluation of options coupling between them, as well as

  10. Can we confidently diagnose pilomatricoma with fine needle aspiration cytology?

    Science.gov (United States)

    Wong, Yin-Ping; Masir, Noraidah; Sharifah, Noor Akmal

    2015-01-01

    Pilomatricomas can be confidently diagnosed cytologically due to their characteristic cytomorphological features. However, these lesions are rarely encountered by cytopathologists and thus pose a diagnostic dilemma to even experienced individuals, especially when the lesions are focally sampled. We describe two cases of histologically confirmed pilomatricoma. The first case is of a 13-year-old boy with posterior cervical 'lymphadenopathy', and the second one is of a 12-year-old girl with a lower cheek swelling. Both aspirates comprised predominantly atypical basal-like cells, with prominent nucleoli. 'Ghost cells' were readily identified by cell block in case two, but cell block in case one yielded no diagnostic material. In case two, pilomatricoma was accurately diagnosed pre-operatively. A cytological suspicion of a neoplastic process was raised in case one. Despite being diagnostically challenging, pilomatricoma can be diagnosed with careful observation of two unique cytological features of the lesions: (1) pathognomonic 'ghost cells' and (2) irregular, saw-toothed, loosely cohesive basaloid cells, with prominent nucleoli. The role of thorough sampling of the lesion, with multiple passes of various sites, cannot be overemphasized.

  11. Irregular Periapical Radiopacity in Mandibular Premolars and Molars

    Directory of Open Access Journals (Sweden)

    S. Aravind Warrier

    2014-01-01

    Full Text Available Increased deposition of cementum is observed in a wide number of both benign and malignant conditions. Many cases are often diagnosed during routine examination as an incidental finding. Diagnosing correctly without confusing it with other similarly appearing lesions, thus avoiding subjecting the patient to unnecessary investigations and stress, is of prime importance. We report one such case, where the patient presented with the routine complaint of a painful tooth, during the investigation of which he was also diagnosed with hypercementosis affecting the mandibular second premolars and molars bilaterally. The literature review reveals that not many cases of hypercementosis are frequently reported.

  12. [Irregular secretion of prolactin in infertile women with normoprolactinemic galactorrhea].

    Science.gov (United States)

    Villanueva Díaz, Carlos A; Echavarria Sánchez, Mirna; Juárez Bengoa, Armando

    2007-02-01

    Abnormal frequency and pulse amplitud of prolactin secretion in micro and macroprolactinomas has been atributed to a dysfunctional tumoral lactotrope. Previous evidence suggests that non tumoral hyperprolactinemia is caused by a hypothalamic dysfunction. The regularity of prolactin secretion has not been studied with cuantitative methods in patients with normoprolactinemic galactorrhea (NPG) which could be considered an entity that precedes non tumoral and tumoral hyperprolactinemia. To analyze the 24-hour prolactin secretion pattern and its secretion regularity in a group of infertile women with normoprolactinemic galatorea. A transversal-comparative study was carried out in 6 infertile women with normoprolactinemic galactorrhea and 4 healthy women as controls. The 24 hour prolactin profile, the ratio night time mean concentration/daytime mean concentrattion (NM/DM ratio) and apparent entropy (Ap En, Ap En ratio) were compared in the two groups. Blunting of the nyctohemeral rythm and nocturn hyperprolactinaemia occurred in patients with normoprolactinemic galactorrhea (NPG). NM/DM ratio was lower in patients with NPG than in controls (1.28 +/- 0.25 vs. 1.75 +/- 0.05; p= 0.01). Higher irregularity of prolactin secretion was found in patients with NPG (ApEn: 0.853 +/- 0.158 vs 0.608 +/- 0.171, p=0.04; Ap En ratio: 0.839 +/- 0.11 vs 0.661 +/- 0.14; p=0.04). The irregularity of prolactin secretion in patients with NPG is not dependant on the presence of a pituitary tumour which suggests that a hypothalamic dysfunction underlies this condition. An irregular secretion and a higher daily mass production of prolactin in patients with NPG could explain both galactorrhea and infertility.

  13. The sunspot cycle and ``auroral'' F layer irregularities

    Science.gov (United States)

    Aarons, J.; Kersley, L.; Rodger, A. S.

    The use of the word ``aurora'' for many different observations at high latitudes has limited the concepts involved; this is particularly true for F region irregularities. Observations setting the position of the auroral oval (Starkov and Fel'dshtein, 1970) were made using primarily the 555.7-nm green line, which is emitted predominantly at E layer heights. These observations have shown that the change in position of the auroral oval for low values of Kp as a function of sunspot cycle is of the order of 1° to 2° between sunspot maximum and sunspot minimum. However, irregularities in the F region show much larger solar cycle variations in the locations of the equatorward boundary, typically 10°. A review of scintillation data indicates that at a given auroral latitude, the scintillation activity increases with sunspot number. In addition, for a constant scintillation intensity, the equatorward boundary moves to lower latitudes as sunspot maximum is approached. We review existing spread F studies and show that for quiet geomagnetic conductions, there is lower occurrence during years of low sunspot numbers than during years of high sunspot numbers. However, the spread F index, related to Δ f/f0F2, is higher during years of low sunspot number than during years of high sunspot number. We demonstrate that this apparent dichotomy can be reconciled by using a new method of normalizing the spread F index by the maximum electron concentration of the F layer. We briefly discuss the possible explanations for the observed solar cycle variations of irregularity occurrence in terms of the absolute values and gradients of electron concentration and the E region conductivity.

  14. Irregular breakfast eating and health status among adolescents in Taiwan

    Directory of Open Access Journals (Sweden)

    Hsieh Yeu-Sheng

    2006-12-01

    Full Text Available Abstract Background Regular breakfast eating (RBE is an important contributor to a healthy lifestyle and health status. The aims of the present study were to evaluate the relationships among irregular breakfast eating (IRBE, health status, and health promoting behavior (HPB for Taiwanese adolescents. Methods A cross-sectional, descriptive design was used to investigate a cluster sample of 1609 (7th -12th grade adolescents located in the metropolitan Tao-Yuan area during the 2005 academic year. The main variables comprised breakfast eating pattern, body weight, and health promoting behaviors. Data were collected by a self-administered questionnaire. Results A total of 1609 participants were studied, 64.1% in junior high school and 35.9% in high school, boys (47.1% and girls (52.9% ranging in age from 12–20 years. Of the total participant population, 28.8% were overweight and nearly one quarter (23.6% reported eating breakfast irregularly during schooldays. The findings indicated that adolescents with RBE had a lower risk of overweight (OR for IRBE vs. RBE = 1.51, 95% CI: 1.12, 2.04, and that the odds of becoming overweight were 51% greater for IRBE than for RBE even after controlling for demographical and HPB variables. IRBE also was a strong indicator for HPB. However, the profile of the high-risk IRBE group was predominantly junior high schoolchildren and/or children living without both parents. Conclusion This study provides valuable information about irregular breakfast eating among adolescents, which is associated with being overweight and with a low frequency of health promoting behavior. School and family health promotion strategies should be used to encourage all adolescents to eat breakfast regularly.

  15. Geostatistical analysis of GPS trajectory data: Space-time densities

    NARCIS (Netherlands)

    Hengl, T.; van Loon, E.E.; Shamoun-Baranes, J.; Bouten, W.; Zhang, J.; Goodchild, M.F.

    2008-01-01

    Creation of density maps and estimation of home range is problematic for observations of animal movement at irregular intervals. We propose a technique to estimate space-time densities by separately modeling animal movement paths and velocities, both as continuous fields. First the length of traject

  16. Similarity estimators for irregular and age-uncertain time series

    Science.gov (United States)

    Rehfeld, K.; Kurths, J.

    2014-01-01

    Paleoclimate time series are often irregularly sampled and age uncertain, which is an important technical challenge to overcome for successful reconstruction of past climate variability and dynamics. Visual comparison and interpolation-based linear correlation approaches have been used to infer dependencies from such proxy time series. While the first is subjective, not measurable and not suitable for the comparison of many data sets at a time, the latter introduces interpolation bias, and both face difficulties if the underlying dependencies are nonlinear. In this paper we investigate similarity estimators that could be suitable for the quantitative investigation of dependencies in irregular and age-uncertain time series. We compare the Gaussian-kernel-based cross-correlation (gXCF, Rehfeld et al., 2011) and mutual information (gMI, Rehfeld et al., 2013) against their interpolation-based counterparts and the new event synchronization function (ESF). We test the efficiency of the methods in estimating coupling strength and coupling lag numerically, using ensembles of synthetic stalagmites with short, autocorrelated, linear and nonlinearly coupled proxy time series, and in the application to real stalagmite time series. In the linear test case, coupling strength increases are identified consistently for all estimators, while in the nonlinear test case the correlation-based approaches fail. The lag at which the time series are coupled is identified correctly as the maximum of the similarity functions in around 60-55% (in the linear case) to 53-42% (for the nonlinear processes) of the cases when the dating of the synthetic stalagmite is perfectly precise. If the age uncertainty increases beyond 5% of the time series length, however, the true coupling lag is not identified more often than the others for which the similarity function was estimated. Age uncertainty contributes up to half of the uncertainty in the similarity estimation process. Time series irregularity

  17. Similarity estimators for irregular and age uncertain time series

    Science.gov (United States)

    Rehfeld, K.; Kurths, J.

    2013-09-01

    Paleoclimate time series are often irregularly sampled and age uncertain, which is an important technical challenge to overcome for successful reconstruction of past climate variability and dynamics. Visual comparison and interpolation-based linear correlation approaches have been used to infer dependencies from such proxy time series. While the first is subjective, not measurable and not suitable for the comparison of many datasets at a time, the latter introduces interpolation bias, and both face difficulties if the underlying dependencies are nonlinear. In this paper we investigate similarity estimators that could be suitable for the quantitative investigation of dependencies in irregular and age uncertain time series. We compare the Gaussian-kernel based cross correlation (gXCF, Rehfeld et al., 2011) and mutual information (gMI, Rehfeld et al., 2013) against their interpolation-based counterparts and the new event synchronization function (ESF). We test the efficiency of the methods in estimating coupling strength and coupling lag numerically, using ensembles of synthetic stalagmites with short, autocorrelated, linear and nonlinearly coupled proxy time series, and in the application to real stalagmite time series. In the linear test case coupling strength increases are identified consistently for all estimators, while in the nonlinear test case the correlation-based approaches fail. The lag at which the time series are coupled is identified correctly as the maximum of the similarity functions in around 60-55% (in the linear case) to 53-42% (for the nonlinear processes) of the cases when the dating of the synthetic stalagmite is perfectly precise. If the age uncertainty increases beyond 5% of the time series length, however, the true coupling lag is not identified more often than the others for which the similarity function was estimated. Age uncertainty contributes up to half of the uncertainty in the similarity estimation process. Time series irregularity

  18. Reducing Inconsistent Rules Based on Irregular Decision Table

    Institute of Scientific and Technical Information of China (English)

    兰轶东; 张霖; 刘连臣

    2004-01-01

    In this paper, we study the problem of rule extraction from data sets using the rough set method. For inconsistent rules due to improper selection of split-points during discretization, and/or to lack of information, we propose two methods to remove their inconsistency based on irregular decision tables.By using these methods, inconsistent rules are eliminated as far as possible, without affecting the remaining consistent rules. Experimental test indicates that use of the new method leads to an improvement in the mean accuracy of the extracted rules.

  19. Multicolor Photometry of the Uranus Irregular Satellites Sycorax and Caliban

    Science.gov (United States)

    Maris, Michele; Carraro, Giovanni; Cremonese, Gabriele; Fulle, Marco

    2001-05-01

    We report on accurate BVRI photometry for the two Uranian irregular satellites Sycorax and Caliban. We derive colors showing that Sycorax is bluer than Caliban. Our data allow us to detect a significant variability in Caliban's light curve, which suggests an estimated period of about 3 hr. Although it is the brighter of the two bodies, Sycorax does not display a strong, statistically significant variability. However, our data seem to suggest a period of about 4 hr. Based on observations carried out at ESO La Silla (Chile). See the Asteroid Properties Database (1993), http://pdssbn.astro.umd.edu/sbnhtml/.

  20. Favelas y fraccionamientos irregulares en São Paulo1

    OpenAIRE

    Silva, Helena Menna Barreto; Ceneviva, Laura Vieira

    2013-01-01

    INTRODUCCIÓN: EL VIRAJE DE LOS AÑOS SETENTA Para las poblaciones de escasos recursos de São Paulo, la ocupación de terrenos en las favelas y en los fraccionamientos irregulares, o el arrendamiento de cuartos en los inmuebles deteriorados de la zona urbanizada (cortiços), constituyen desde hace varias décadas la única posibilidad de acceso a la vivienda. Hacia mediados de los años setenta, la situación alcanzó un nivel crítico. Para los cientos de miles de habitantes que habían adquirido terre...

  1. Mapa MEGNO para satélites irregulares de Satuno

    Science.gov (United States)

    Moyano, M. M.; Leiva, A. M.

    By implementing the elliptic restricted three-body model we obtain high resolution dynamical maps in the phase space region corresponding to that where Saturn's irregular satellites are currently found. The nature of the trajectories is characterized by the MEGNO chaos indicator (Cincotta P. and Simó C., 2000), which allows to identify regions of chaotic and quasi- periodic trajectories much faster than with other indicators (e.g. Lyapunov exponents). The results obtained allow to identify with great detail the boundaries of the regions of regular motion, chaotic motion, and substruc- tures associated to mean motion resonances. FULL TEXT IN SPANISH

  2. El derecho al trabajo y los extranjeros irregulares

    OpenAIRE

    2010-01-01

    El artículo analiza desde una perspectiva de derecho constitucional la situación en España de los trabajadores extranjeros irregulares, defiende que estos poseen un derecho al trabajo de rango constitucional e intenta delimitar el contenido de este derecho en relación al derecho al trabajo del que son titulares los españoles. Plantea como conclusión que el contenido de dicho derecho no tiene porqué coincidir con el de los españoles. De hecho, considera que difiere del de est...

  3. Irregular subharmonic cluster patterns in an autonomous photoelectrochemical oscillator.

    Science.gov (United States)

    Miethe, Iljana; García-Morales, Vladimir; Krischer, Katharina

    2009-05-15

    Unusual subharmonic cluster patterns are observed during the oscillatory electro-oxidation of n-Si(111) under illumination. 2D in situ imaging of the electrode by means of an ellipsometric setup allows local variations in the oxide layer thickness to be monitored. The local oscillators exhibit an irregular distribution of the amplitude with the extrema locked to the constant base frequency of the total current. In addition, Ising 2-phase clustering occurs at half the base frequency. This intrinsic dynamics is described by means of a modified complex Ginzburg-Landau equation.

  4. TCM Treatment for Gynaecological Diseases-Irregular Menstruation

    Institute of Scientific and Technical Information of China (English)

    Engin CAN

    2008-01-01

    @@ Menstruation is the periodic shedding(usually monthly)of the lining of the womb.Generally speaking,menstruation starts during puberty around 10-16 years old and continues until the menopause about 45-55 years old.An average menstrual cycle is about 28 days,but it may vary between 24-35 days.According to a study most women have more than 500 periods in a lifetime.Any abnormality of the above menstrual conditins can be regarded as irregular.

  5. Similarity estimators for irregular and age uncertain time series

    Directory of Open Access Journals (Sweden)

    K. Rehfeld

    2013-09-01

    Full Text Available Paleoclimate time series are often irregularly sampled and age uncertain, which is an important technical challenge to overcome for successful reconstruction of past climate variability and dynamics. Visual comparison and interpolation-based linear correlation approaches have been used to infer dependencies from such proxy time series. While the first is subjective, not measurable and not suitable for the comparison of many datasets at a time, the latter introduces interpolation bias, and both face difficulties if the underlying dependencies are nonlinear. In this paper we investigate similarity estimators that could be suitable for the quantitative investigation of dependencies in irregular and age uncertain time series. We compare the Gaussian-kernel based cross correlation (gXCF, Rehfeld et al., 2011 and mutual information (gMI, Rehfeld et al., 2013 against their interpolation-based counterparts and the new event synchronization function (ESF. We test the efficiency of the methods in estimating coupling strength and coupling lag numerically, using ensembles of synthetic stalagmites with short, autocorrelated, linear and nonlinearly coupled proxy time series, and in the application to real stalagmite time series. In the linear test case coupling strength increases are identified consistently for all estimators, while in the nonlinear test case the correlation-based approaches fail. The lag at which the time series are coupled is identified correctly as the maximum of the similarity functions in around 60–55% (in the linear case to 53–42% (for the nonlinear processes of the cases when the dating of the synthetic stalagmite is perfectly precise. If the age uncertainty increases beyond 5% of the time series length, however, the true coupling lag is not identified more often than the others for which the similarity function was estimated. Age uncertainty contributes up to half of the uncertainty in the similarity estimation process. Time

  6. Nursing diagnoses in overweight adolescents

    Directory of Open Access Journals (Sweden)

    Raphaela Santos do Nascimento Rodrigues

    2013-05-01

    Full Text Available This study aimed to identify nursing diagnoses in overweight adolescents from public schools, according to the International Classification for Nursing Practice. A population-based cross-sectional study that investigated the socio-demographic, behavioural and psychological characteristics of adolescents aged from 10 to 14 years. 11 nursing diagnoses were identified: "Risk of overweight", "Risk of impaired adolescent development", "Risk of insecurity in parental role performance", "Risk of the family impaired ability to manage diet regime", "Risk of impaired ability to manage diet regime", "Risk of lack of knowledge of dietary regime", "Risk of excess food intake", "Risk of negative self-image", "Risk of low self-esteem", "Risk of impaired social well-being" and "Impaired exercise pattern". These diagnoses reflect the multifactorial nature of obesity, highlighting the need for interdisciplinary and intersectoral articulation of nursing interventions for prevention and control of overweight.

  7. Challenges in diagnosing hepatic encephalopathy.

    Science.gov (United States)

    Weissenborn, K

    2015-02-01

    The term "hepatic encephalopathy" (HE) covers the neuropsychiatric syndrome associated with acute, chronic and acute-on-chronic liver disease (CLD). This paper deals with clinical features and diagnosis of HE in patients with liver cirrhosis and portal hypertension or porto-systemic shunts. The possible impact of concomitant disorders and the cirrhosis underlying liver disease upon brain function is described emphasizing the need of a detailed diagnostic work up of every individual case before diagnosing HE. Currently used methods for diagnosing minimal or covert hepatic encephalopathy are compared with regard to their sensitivity and specificity for diagnosing HE against the background of a multitude of concomitant disorders and diseases that could contribute to brain dysfunction.

  8. Influence of the turbulence on the processes formation and relaxation of periodical artificial irregularities in the lower ionosphere

    Science.gov (United States)

    Terina, Galina

    2016-07-01

    The periodic artificial irregularities (PAI) are formed in the standing wave field of powerful radio emission. The study the scattering of probing radio pulses on PAI allowed to create a method diagnostics of the ionospheric plasma parameters - the resonance scattering method (RSM) of radio waves on the periodic artificial irregularities. The different mechanisms of PAI formation in D and E ranges of the lower ionosphere were investigated (G.I. Terina, J.Atm.Terr.Phys., 1996, 58, 645). However the height range 75-90 km where there is turbulent diffusion, remained unstudied. In present paper the study results the processes formation and relaxation of periodic artificial irregularities in this height range are considered. For the analysis the processes of the formation and the relaxation of PAI one can use quasi-hydrodynamic equation for the homogeneous isotropic ionospheric plasma. Under the small disturbances, quasi-neutral plasma and some assumptions can to obtain the differential equations for regular and fluctuation PAI parts, which take account: the ambipolar diffusion, the temperature dependence of the coefficient of electrons recombination, the temperature dependence of the coefficient of the electrons attachment to the neutral molecules and also the turbulent diffusion and caused by it small-scale irregularities of the electron density. The solutions of the inhomogeneous and homogeneous equations present the processes of the formation and relaxation of PAI accordingly. The numerical estimations of obtained solutions showed that the main reasons of PAI formation in considered range of heights are the small-scale irregularities of the electron concentration and the turbulence diffusion. The obtained results qualitatively agree with results of experimental investigations. The experiments were carried out at the heating facilities "Zimenki" and "Sura". The heater transmitter periodically was switched on for several seconds and off for the same duration. The

  9. Immunological methods for diagnosing neurocysticercosis

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, R.E.; Estrada, J.J.; Grogl, M.

    1989-01-31

    A method is described for diagnosing active human neurocysticercosis by detecting the presence of at least one Taenia solium larval antigen in cerebrospinal fluid, which comprises: contacting cerebrospinal fluid from a human to be diagnosed with a solid support, wherein the support binds with a Taenia solium larval antigen if present, contacting the support with a first antibody, wherein the first antibody binds with a larval Taenia solium antigen if present in the cerebrospinal fluid, contacting the solid support with a detectable second antibody which will bind with the first antibody, and detecting the second antibody bound to the support.

  10. In situ measurements of plasma irregularity growth in the cusp ionosphere

    Science.gov (United States)

    Oksavik, K.; Moen, J.; Lester, M.; Bekkeng, T. A.; Bekkeng, J. K.

    2012-11-01

    The Investigation of Cusp Irregularities (ICI-2) sounding rocket was launched on 5 December 2008 from Ny-Ålesund, Svalbard. The high-resolution rocket data are combined with data from an all-sky camera, the EISCAT Svalbard Radar, and the SuperDARN Hankasalmi radar. These data sets are used to characterize the spatial structure of F region irregularities in the dayside cusp region. We use the data set to test two key mechanisms for irregularity growth; the Kelvin-Helmholtz (KH) and gradient drift (GD) instabilities. Except for a promising interval of 4-6 km irregularities, the KH growth rate was found to be too slow to explain the observed plasma irregularities. The time history of the plasma gives further support that structured particle precipitation could be an important source of kilometer- to hectometer-scale “seed” irregularities, which are then efficiently broken down into decameter-scale irregularities by the GD mechanism.

  11. Human Rights of Irregular Immigrants: A Challenge for the Universality of Human Rights

    Directory of Open Access Journals (Sweden)

    Luljeta Ikonomi

    2013-07-01

    Full Text Available Irregular immigration is a phenomenon with a substantial impact for the majority of the countries. The paper analyses whether there is an adequate human rights framework for protection of irregular immigrants or whether the irregular status exempts the migrants from the protection of international human rights law. If this is the case, then the human rights universality has failed. The paper takes into consideration the developments in the International and EU Law, as well as in the jurisprudence of the international tribunals regarding protection of irregular immigrants. It is divided into three main sections. The first section informs briefly on the dynamics of irregular immigrants; the second section analyses the legislation on irregular immigration from the perspective of the state sovereignty, the third section analyses the human rights law and the protection it affords to irregular immigrants, pursuant to the interpretation of International tribunals.

  12. Ionospheric storm effects and equatorial plasma irregularities during the 17-18 March 2015 event

    Science.gov (United States)

    Zhou, Yun-Liang; Lühr, Hermann; Xiong, Chao; Pfaff, Robert F.

    2016-09-01

    The intense magnetic storm on 17-18 March 2015 caused large disturbances of the ionosphere. Based on the plasma density (Ni) observations performed by the Swarm fleet of satellites, the Gravity Recovery and Climate Experiment mission, and the Communications/Navigation Outage Forecasting System satellite, we characterize the storm-related perturbations at low latitudes. All these satellites sampled the ionosphere in morning and evening time sectors where large modifications occurred. Modifications of plasma density are closely related to changes of the solar wind merging electric field (Em). We consider two mechanisms, prompt penetration electric field (PPEF) and disturbance dynamo electric field (DDEF), as the main cause for the Ni redistribution, but effects of meridional wind are also taken into account. At the start of the storm main phase, the PPEF is enhancing plasma density on the dayside and reducing it on the nightside. Later, DDEF takes over and causes the opposite reaction. Unexpectedly, there appears during the recovery phase a strong density enhancement in the morning/prenoon sector and a severe Ni reduction in the afternoon/evening sector, and we suggest a combined effect of vertical plasma drift, and meridional wind is responsible for these ionospheric storm effects. Different from earlier studies about this storm, we also investigate the influence of storm dynamics on the initiation of equatorial plasma irregularities (EPIs). Shortly after the start of the storm main phase, EPIs appear in the postsunset sector. As a response to a short-lived decline of Em, EPI activity appears in the early morning sector. Following the second start of the main phase, EPIs are generated for a few hours in the late evening sector. However, for the rest of the storm main phase, no more EPIs are initiated for more than 12 h. Only after the onset of recovery phase does EPI activity start again in the postmidnight sector, lasting more than 7 h. This comprehensive view of

  13. Irregular Information of the Rainstorm in a Continuous Rainy Weather

    Institute of Scientific and Technical Information of China (English)

    LI; Ming-juan

    2012-01-01

    [Objective]The research aimed to analyze irregular information of the local rainstorm process (during 5-6 September,2009) in autumn continuous rainy weather in north Shaanxi. [Method] Based on V-3θ chart, routine observation data provided by Micaps system, satellite cloud chart and data at 100 automatic meteorological stations of Shaanxi, for rainstorm process in autumn continuous rainy weather in north Shaanxi during 4-10 September, 2009, by using structure analysis method, irregular information in local rainstorm weather was analyzed. [Result]In whole precipitation process, atmospheric structure in rainstorm zone presented obvious evolution process. Before precipitation, typical atmospheric structure information of the sudden convective weather appeared. Obvious ultra-low temperature structure appeared at 200 hPa, and consistent clockwise rotation flow was at vertical wind field. Meanwhile, water vapor was sufficient, and unstable energy existed at low layer. Structure characteristic of the convective strong precipitation appeared by advancing for 12h. As precipitation weakened, unstable energy was released, and ultra-low temperature disappeared. [Conclusion]The research provided some thoughts for the forecast of such weather process.

  14. Using Radio Irregularity for Increasing Residential Energy Awareness

    Directory of Open Access Journals (Sweden)

    A. Miljković

    2012-06-01

    Full Text Available Radio irregularity phenomenon is often considered as a shortcoming of wireless networks. In this paper, the method of using radio irregularity as an efficient human presence detection sensor in smart homes is presented. The method is mainly based on monitoring variations of the received signal strength indicator (RSSI within the messages used for the communication between wireless smart power outlets. The radio signals used for the inter-outlets communication can be absorbed, diffracted or reflected by objects in their propagation paths. When a human enters the existing radio communication field, the variation of the signal strength at the receiver is even more expressed. Based on the detected changes and compared to the initial thresholds set during the initialization phase, the system detects human presence. The proposed solution increases user awareness and automates the power control in households, with the primary goal to contribute in residential energy savings. Compared to conventional sensor networks, this approach preserves the sensorial intelligence, simplicity and low installation costs, without the need for additional sensors integration.

  15. Buckling analysis of partially corroded steel plates with irregular surfaces

    Indian Academy of Sciences (India)

    Ahmad Rahbar-Ranji

    2014-04-01

    Corrosion is a long-term, inevitable process, lessens the thickness and load carrying capacity of structures. Old steel structures are more vulnerable to buckling, yielding and fracture due to corrosion. In lieu of a detailed analysis, average thickness assumption is employed for general type of corrosion. However, the estimation of load carrying capacity reduction of corroded structures typically need a much higher level of accuracy, since the actual corroded plates would have irregular surfaces. The objective of this article is to determine the effect of general corrosion on reduction of elastic buckling strength of both-sided partially corroded plates with irregular surfaces. Eigenvalue analysis using finite element method is employed for Euler stress calculation of corroded plates. The effects of different influential parameters are investigated and it is found that, aspect ratio of plate, location of corroded area, standard deviation of thickness diminution and concentration of corrosion have influence on reduction of elastic buckling strength. Reduction of elastic buckling strength is very sensitive to the amount of corrosion loss. The higher the amount of corrosion loss, the more reduction of elastic buckling strength.

  16. Unsteady magnetohydrodynamic blood flow through irregular multi-stenosed arteries.

    Science.gov (United States)

    Mustapha, Norzieha; Amin, Norsarahaida; Chakravarty, Santabrata; Mandal, Prashanta Kumar

    2009-10-01

    Flow of an electrically conducting fluid characterizing blood through the arteries having irregular shaped multi-stenoses in the environment of a uniform transverse magnetic-field is analysed. The flow is considered to be axisymmetric with an outline of the irregular stenoses obtained from a three-dimensional casting of a mild stenosed artery, so that the physical problem becomes more realistic from the physiological point of view. The marker and cell (MAC) and successive-over-relaxation (SOR) methods are respectively used to solve the governing unsteady magnetohydrodynamic (MHD) equations and pressure-Poisson equation quantitatively and to observe the flow separation. The results obtained show that the flow separates mostly towards the downstream of the multi-stenoses. However, the flow separation region keeps on shrinking with the increasing intensity of the magnetic-field which completely disappears with sufficiently large value of the Hartmann number. The present observations certainly have some clinical implications relating to magnetotherapy which help reducing the complex flow separation zones causing flow disorder leading to the formation and progression of the arterial diseases.

  17. Hydrophobic pulses predict transmembrane helix irregularities and channel transmembrane units

    Directory of Open Access Journals (Sweden)

    Claustres Mireille

    2011-05-01

    Full Text Available Abstract Background Few high-resolution structures of integral membranes proteins are available, as crystallization of such proteins needs yet to overcome too many technical limitations. Nevertheless, prediction of their transmembrane (TM structure by bioinformatics tools provides interesting insights on the topology of these proteins. Methods We describe here how to extract new information from the analysis of hydrophobicity variations or hydrophobic pulses (HPulses in the sequence of integral membrane proteins using the Hydrophobic Pulse Predictor, a new tool we developed for this purpose. To analyze the primary sequence of 70 integral membrane proteins we defined two levels of analysis: G1-HPulses for sliding windows of n = 2 to 6 and G2-HPulses for sliding windows of n = 12 to 16. Results The G2-HPulse analysis of 541 transmembrane helices allowed the definition of the new concept of transmembrane unit (TMU that groups together transmembrane helices and segments with potential adjacent structures. In addition, the G1-HPulse analysis identified helix irregularities that corresponded to kinks, partial helices or unannotated structural events. These irregularities could represent key dynamic elements that are alternatively activated depending on the channel status as illustrated by the crystal structures of the lactose permease in different conformations. Conclusions Our results open a new way in the understanding of transmembrane secondary structures: hydrophobicity through hydrophobic pulses strongly impacts on such embedded structures and is not confined to define the transmembrane status of amino acids.

  18. 3D Reconstruction of Irregular Buildings and Buddha Statues

    Science.gov (United States)

    Zhang, K.; Li, M.-j.

    2014-04-01

    Three-dimensional laser scanning could acquire object's surface data quickly and accurately. However, the post-processing of point cloud is not perfect and could be improved. Based on the study of 3D laser scanning technology, this paper describes the details of solutions to modelling irregular ancient buildings and Buddha statues in Jinshan Temple, which aiming at data acquisition, modelling and texture mapping, etc. In order to modelling irregular ancient buildings effectively, the structure of each building is extracted manually by point cloud and the textures are mapped by the software of 3ds Max. The methods clearly combine 3D laser scanning technology with traditional modelling methods, and greatly improves the efficiency and accuracy of the ancient buildings restored. On the other hand, the main idea of modelling statues is regarded as modelling objects in reverse engineering. The digital model of statues obtained is not just vivid, but also accurate in the field of surveying and mapping. On this basis, a 3D scene of Jinshan Temple is reconstructed, which proves the validity of the solutions.

  19. An Irregular Wave Maker of Active Absorption with VOF Method

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A numerical irregular wave flume with active absorption of re-reflected waves is simulated by use of volume of fluid (VOF) method. An active absorbing wave-maker based on linear wave-theory is set on the left boundary of the wave flume. The progressive waves and the absorbing waves are generated simultaneously at the active wave generating-absorbing boundary. The absorbing waves are generated to eliminate the waves coming back to the generating boundary due to reflection from the outflow boundary and the structures. SIRW method proposed by Frigaard and Brorsen (1995) is used to separate the incident waves and reflected waves. The digital filters are designed based on the surface elevation signals of the two wave gauges. The corrected velocity of the wave-maker paddle is the output from the digital filter in real time. The numerical results of regular and irregular waves by the active absorbing-generating boundary are compared with the numerical results by the ordinary generating boundary to verify the performance of the active absorbing generator boundary. The differences between the initial incident waves and the estimated incident waves are analyzed.

  20. Oral breathing: dentomaxillofacial irregularities associated with nasorespiratory and orthopedic dysfunctions.

    Directory of Open Access Journals (Sweden)

    Clotilde de la Caridad Mora Pérez

    2009-04-01

    Full Text Available Background: Human beings are conditioned to breathe through the nose and feed through the mouth, when this physiological mechanism is interrupted facial and general growth is also affected. Objective: To characterize Angle´s Class II malocclusions in oral breathers with nasorespiratory and orthopedic dysfunctions. Method: A correlational, observational and descriptive study was developed from December 2004 to November 2005 including clinical examination of 833 children out of which 60 were selected to take part in this study. Each case was analyzed in Orthodontia, Orthopedics and Otolaryngology consultations. The studied variables were: age, sex, nasorespiratory disorders, orthopedic dysfunctions, dental-maxillofacial irregularities. Results: The mot frequent dental-maxillofacial irregularities were: bilabial incompetence, transversal micrognathism, vestibular version, overjet and overbite. The most important nasorespiratory dysfunctions found in these children were adenoiditis, and tonsil hypertrophy. The most outstanding orthopedic dysfunction was ciphosis. Conclusion: It is conclusive to state that there is a high relationship between dentomaxillofacial anomalies and nasorespiratory and orthopedic dysfunctions.

  1. Scatter dose summation for irregular fields: speed and accuracy study.

    Science.gov (United States)

    DeWyngaert, J K; Siddon, R L; Bjarngard, B E

    1986-05-01

    Using program IRREG as a standard, we have compared speed and accuracy of several algorithms that calculate the scatter dose in an irregular field. All the algorithms, in some manner, decompose the irregular field into component triangles and obtain the scatter dose as the sum of the contributions from those triangles. Two of the algorithms replace each such component triangle with a sector of a certain "effective radius": in one case the average radius of the triangle, in the other the radius of the sector having the same area as the component triangle. A third algorithm decomposes each triangle further into two right triangles and utilizes the precalculated "equivalent radius" of each, to find the scatter contribution. For points near the center of a square field, all the methods compare favorably in accuracy to program IRREG, with less than a 1% error in total dose and with approximately a factor of 3-5 savings in computation time. Even for extreme rectangular fields (2 cm X 30 cm), the methods using the average radius and the equivalent right triangles agree to within 2% in total dose and approximately a factor of 3-4 savings in computation time.

  2. Scattering of high-frequency seismic waves caused by irregular surface topography and small-scale velocity inhomogeneity

    Science.gov (United States)

    Takemura, Shunsuke; Furumura, Takashi; Maeda, Takuto

    2015-04-01

    Based on 3-D finite difference method simulations of seismic wave propagation, we examined the processes by which the complex, scattered high-frequency (f > 1 Hz) seismic wavefield during crustal earthquakes is developed due to heterogeneous structure, which includes small-scale velocity inhomogeneity in subsurface structure and irregular surface topography on the surface, and compared with observations from dense seismic networks in southwestern Japan. The simulations showed the process by which seismic wave scattering in the heterogeneous structure develops long-duration coda waves and distorts the P-wave polarization and apparent S-wave radiation pattern. The simulations revealed that scattering due to irregular topography is significant only near the station and thus the topographic scattering effects do not accumulate as seismic waves propagate over long distances. On the other hand, scattering due to velocity inhomogeneity in the subsurface structure distorts the seismic wavefield gradually as seismic waves propagate. The composite model, including both irregular topography and velocity inhomogeneity, showed the combined effects. Furthermore, by introducing irregular topography, the effects of seismic wave scattering on both body and coda waves were stronger than in the model with velocity inhomogeneity alone. Therefore, to model the high-frequency seismic wavefield, both topography and velocity inhomogeneity in the subsurface structure should be taken into account in the simulation model. By comparing observations with the simulations including topography, we determined that the most preferable small-scale velocity heterogeneity model for southwestern Japan is characterized by the von Kármán power spectral density function with correlation distance a = 5 km, rms value of fluctuation ɛ = 0.07 and decay order κ = 0.5. We also demonstrated that the relative contribution of scattering due to the topography of southwestern Japan is approximately 12 per cent.

  3. How Is Fanconi Anemia Diagnosed?

    Science.gov (United States)

    ... from the NHLBI on Twitter. How Is Fanconi Anemia Diagnosed? People who have Fanconi anemia (FA) are born with the disorder. They may ... questions about: Any personal or family history of anemia Any surgeries you’ve had related to the ...

  4. Interhemispheric subdural empyema diagnosed by CT and cured by antibiotic therapy

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, I.; Fukui, M.; Furuhashi, N.; Kanda, T.; Tazaki, Y. (Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Medicine)

    1981-09-01

    A case of interhemispheric subdural empyema cured by high doses of antibiotics was reported. A 23-year-old man was admitted with complaints of headache, fever and motor weakness of the left lower leg of 2 days' duration. The neurological examination revealed neck stiffness, motor weakness and sensory disturbance of left lower leg. The WBS count was 26,000/cumm, and ESR was 74 mm/hour. The CSF showed a pressure of 230 mm H/sub 2/O and contained 1001/3 cells (63% polymorphonuclears, 37% lymphocytes) in association with slight elevation of protein but with normal sugar content. The CSF culture was negative. Administration of high doses of antibiotics was started on the first hospital day. On the fourth hospital day, Jacksonian seizures occurred in the left lower extremity, and were controlled by anticonvulsants. CT scans with contrast enhancement revealed an area of low density in the right interhemispheric space with irregular marginal enhancement. Right carotid arteriography demonstrated a small oval avascular space along the interhemispheric cistern. The abnormalities on CT scan disappeared after one month, when the patient was discharged without neurological deficit. Unlike the previously reported cases with interhemispheric subdural empyema commonly associated with a collection of pus over the cerebral convexities, a localized interhemispheric subdural empyema as was found in the present case appears to be a very rare condition. The interhemispheric subdural empyema has been thought to be exclusively surgical indication and, to the best of our knowlage, there is no report in the literature of a case with successful medical treatment. However, successful treatment by antibiotics alone may become more practical if the diagnoses could be made in the early stage with the aid of CT scan.

  5. Outside-in Shrinking of the Star-forming Disk of Dwarf Irregular Galaxies

    CERN Document Server

    Zhang, Hong-Xin; Elmegreen, Bruce G; Gao, Yu; Schruba, Andreas

    2011-01-01

    We have studied multi-band surface brightness profiles of a representative sample of 34 nearby dwarf irregular galaxies (dIrrs). Our data include GALEX FUV/NUV, UBV, H\\alpha, and Spitzer 3.6 \\mum images. These galaxies constitute the majority of the LITTLE THINGS survey. By modeling the azimuthal averages of the spectral energy distributions with a complete library of star formation (SF) histories, we derived the stellar mass surface density distributions and the SF rate averaged over three different timescales: the recent 0.1 Gyr, 1 Gyr and a Hubble time. We find that, for \\sim 80% (27 galaxies) of our sample galaxies, radial profiles (at least in the outer part) at shorter wavelengths have shorter disk scale lengths than those at longer wavelengths. This indicates that the star-forming disk has been shrinking. In addition, the radial distributions of the stellar mass surface density are well described as piece-wise exponential profiles, and \\sim 80% of the galaxies have steeper mass profiles in the outer di...

  6. Segregation characteristics of irregular binaries in gas solid fluidized beds——An ANN-approach

    Institute of Scientific and Technical Information of China (English)

    Abanti Sahoo; Gopendra Kishore Roy

    2008-01-01

    Binary mixtures of irregular materials of different particle sizes and/or particle densities are fluidized in a 15-cm diameter column with a perforated plate distributor. An attempt has been made in this work to determine the segregation characteristics of jetsam particles for both the homogeneous and heterogeneous binary mixtures in terms of segregation distance by correlating it to the various system parameters, viz. initial static bed height, height of a layer of particles above the bottom grid, superficial gas velocity and average particle size and/or particle densities of the mixture through the dimensional analysis. Correlation on the basis of Artificial Neural Network approach has also been developed with the above system parameters thereby authenticating the development of correlation by the former approach. The calculated values of the segregation distance obtained for both the homogeneous and heterogeneous binary mixtures from both the types of fluidized beds (i. e. under the static bed condition and the fluidized bed condition) have also been compared with each other.

  7. A High-Resolution Radio Continuum Study Of The Dwarf Irregular Galaxy IC 10

    Science.gov (United States)

    Westcott, J.; Brinks, E.; Beswick, R. J.; Heesen, V.; Argo, M. K.; Baldi, R. D.; Fenech, D. M.; McHardy, I. M.; Smith, D. J. B.; Williams, D. R. A.

    2017-01-01

    We present high-resolution e-MERLIN radio continuum maps of the Dwarf Irregular galaxy IC 10 at 1.5 GHz and 5 GHz. We detect 11 compact sources at 1.5 GHz, 5 of which have complementary detections at 5 GHz. We classify 3 extended sources as compact HII regions within IC 10, 5 sources as contaminating background galaxies and identify 3 sources which require additional observations to classify. We do not expect that any of these 3 sources are Supernova Remnants as they will likely be resolved out at the assumed distance of IC 10 (0.7 Mpc). We correct integrated flux densities of IC 10 from the literature for contamination by unrelated background sources and obtain updated flux density measurements of 354 ± 11 mJy at 1.5 GHz and 199 ± 9 mJy at 4.85 GHz. The background contamination does not contribute significantly to the overall radio emission from IC 10, so previous analysis concerning its integrated radio properties remain valid.

  8. Young star clusters in the outer disks of LITTLE THINGS dwarf irregular galaxies

    CERN Document Server

    Hunter, Deidre A; Gehret, Elizabeth

    2016-01-01

    We examine FUV images of the LITTLE THINGS sample of nearby dwarf irregular (dIrr) and Blue Compact Dwarf (BCD) galaxies to identify distinct young regions in their far outer disks. We use these data, obtained with the Galaxy Evolution Explorer satellite, to determine the furthest radius at which in situ star formation can currently be identified. The FUV knots are found at distances from the center of the galaxies of 1 to 8 disk scale lengths and have ages of <20 Myrs and masses of 20 to 1E5 Msolar. The presence of young clusters and OB associations in the outer disks of dwarf galaxies shows that dIrrs do have star formation taking place there in spite of the extreme nature of the environment. Most regions are found where the HI surface density is ~1 Msolar per pc2, although both the HI and dispersed old stars go out much further. This limiting density suggests a cutoff in the ability to form distinct OB associations and perhaps even stars. We compare the star formation rates in the FUV regions to the ave...

  9. On the signature of positively charged dust particles on plasma irregularities in the mesosphere

    Science.gov (United States)

    Mahmoudian, A.; Scales, W. A.

    2013-11-01

    Recent rocket payloads have studied the properties of aerosol particles within the ambient plasma environment in the polar mesopause region and measured the signature of the positively charged particles with number densities of (2000 cm-3) for particles of 0.5-1 nm in radius. The measurement of significant numbers of positively charged aerosol particles is unexpected from the standard theory of aerosol charging in plasma. Nucleation on the cluster ions is one of the most probable hypotheses for the positive charge on the smallest particles. This work attempts to study the correlation and anti-correlation of fluctuations in the electron and ion densities in the background plasma by adopting the proposed hypothesis of positive dust particle formation. The utility being that it may provide a test for determining the presence of positive dust particles. The results of the model described show good agreement with observed rocket data. As an application, the model is also applied to investigate the electron irregularity behavior during radiowave heating assuming the presence of positive dust particles. It is shown that the positive dust produces important changes in the behavior during Polar Mesospheric Summer Echo PMSE heating experiments that can be described by the fluctuation correlation and anti-correlation properties.

  10. Diagnosing GORD in respiratory medicine

    Directory of Open Access Journals (Sweden)

    Chris James Timms

    2011-07-01

    Full Text Available Gastroesophageal reflux disease is increasing in prevalence and is associated with several lung diseases such as asthma and COPD. Current diagnostic methods are imperfect, being insensitive, nonspecific, expensive or invasive. An accurate diagnosis of GORD can aid effective treatment with a significant clinical impact. Novel methods such as exhaled breath condensate analysis and electronic nose technology have the potential to improve the accuracy of diagnosing GORD.

  11. Reconstruction of Multidimensional Signals from Irregular Noisy Samples

    CERN Document Server

    Nordio, A; Viterbo, E

    2008-01-01

    We focus on a multidimensional field with uncorrelated spectrum, and study the quality of the reconstructed signal when the field samples are irregularly spaced and affected by independent and identically distributed noise. More specifically, we apply linear reconstruction techniques and take the mean square error (MSE) of the field estimate as a metric to evaluate the signal reconstruction quality. We find that the MSE analysis could be carried out by using the closed-form expression of the eigenvalue distribution of the matrix representing the sampling system. Unfortunately, such distribution is still unknown. Thus, we first derive a closed-form expression of the distribution moments, and we find that the eigenvalue distribution tends to the Marcenko-Pastur distribution as the field dimension goes to infinity. Finally, by using our approach, we derive a tight approximation to the MSE of the reconstructed field.

  12. Evaluation of Surface Slope Irregularity in Linear Parabolic Solar Collectors

    Directory of Open Access Journals (Sweden)

    F. Francini

    2012-01-01

    Full Text Available The paper describes a methodology, very simple in its application, for measuring surface irregularities of linear parabolic collectors. This technique was principally developed to be applied in cases where it is difficult to use cumbersome instruments and to facilitate logistic management. The instruments to be employed are a digital camera and a grating. If the reflector surface is defective, the image of the grating, reflected on the solar collector, appears distorted. Analyzing the reflected image, we can obtain the local slope of the defective surface. These profilometric tests are useful to identify and monitor the mirror portions under mechanical stress and to estimate the losses caused by the light rays deflected outside the absorber.

  13. The Panchromatic STARBurst IRregular Dwarf Survey (STARBIRDS) Data

    CERN Document Server

    McQuinn, Kristen B W; Skillman, Evan D

    2016-01-01

    Understanding star formation in resolved low mass systems requires the integration of information obtained from observations at different wavelengths. We have combined new and archival multi-wavelength observations on a set of 20 nearby starburst and post-starburst dwarf galaxies to create a data archive of calibrated, homogeneously reduced images. Named the panchromatic "STARBurst IRregular Dwarf Survey" (STARBIRDS) archive, the data are publicly accessible through the Mikulski Archive for Space Telescopes (MAST). This first release of the archive includes images from the Galaxy Evolution Explorer Telescope (GALEX), the Hubble Space Telescope (HST), and the Spitzer Space Telescope (Spitzer) MIPS instrument. The datasets include flux calibrated, background subtracted images, that are registered to the same world coordinate system. Additionally, a set of images are available which are all cropped to match the HST field of view. The GALEX and Spitzer images are available with foreground and background contamina...

  14. A deeper look at the color of Saturnian irregular satellites

    CERN Document Server

    Grav, T

    2006-01-01

    We have performed broadband color photometry of the twelve brightest irregular satellites of Saturn with the goal of understanding their surface composition, as well as their physical relationship. We find that the satellites have a wide variety of different surface colors, from the negative spectral slopes of the two retrograde satellites S IX Phoebe (S'=-2.5+/-0.4 %/100nm) and S XXV Mundilfari (S'=-5.0+/-1.9 %/100nm) to the fairly red slope of S XXII Ijiraq (S'=19.5+/-0.9 %/100nm). We further find that there exist a correlation between dynamical families and spectral slope, with the prograde clusters, the Gallic and Inuit, showing tight clustering in colors among most of their members. The retrograde objects are dynamically and physically more dispersed, but some internal structure is apparent.

  15. Irregular Computations in Fortran – Expression and Implementation Strategies

    Directory of Open Access Journals (Sweden)

    Jan F. Prins

    1999-01-01

    Full Text Available Modern dialects of Fortran enjoy wide use and good support on high‐performance computers as performance‐oriented programming languages. By providing the ability to express nested data parallelism, modern Fortran dialects enable irregular computations to be incorporated into existing applications with minimal rewriting and without sacrificing performance within the regular portions of the application. Since performance of nested data‐parallel computation is unpredictable and often poor using current compilers, we investigate threading and flattening, two source‐to‐source transformation techniques that can improve performance and performance stability. For experimental validation of these techniques, we explore nested data‐parallel implementations of the sparse matrix‐vector product and the Barnes–Hut n‐body algorithm by hand‐coding thread‐based (using OpenMP directives and flattening‐based versions of these algorithms and evaluating their performance on an SGI Origin 2000 and an NEC SX‐4, two shared‐memory machines.

  16. Towards intrinsic magnetism of graphene sheets with irregular zigzag edges.

    Science.gov (United States)

    Chen, Lianlian; Guo, Liwei; Li, Zhilin; Zhang, Han; Lin, Jingjing; Huang, Jiao; Jin, Shifeng; Chen, Xiaolong

    2013-01-01

    The magnetism of graphene has remained divergent and controversial due to absence of reliable experimental results. Here we show the intrinsic magnetism of graphene edge states revealed based on unidirectional aligned graphene sheets derived from completely carbonized SiC crystals. It is found that ferromagnetism, antiferromagnetism and diamagnetism along with a probable superconductivity exist in the graphene with irregular zigzag edges. A phase diagram is constructed to show the evolution of the magnetism. The ferromagnetic ordering curie-temperature of the fundamental magnetic order unit (FMOU) is 820 ± 80 K. The antiferromagnetic ordering Neel temperature of the FMOUs belonging to different sublattices is about 54 ± 2 K. The diamagnetism is similar to that of graphite and can be well described by the Kotosonov's equation. Our experimental results provide new evidences to clarify the controversial experimental phenomena observed in graphene and contribute to a deeper insight into the nature of magnetism in graphene based system.

  17. Irregular Coarse-Grain Data Parallelism under LPARX

    Directory of Open Access Journals (Sweden)

    Scott R. Kohn

    1996-01-01

    Full Text Available LPARX is a software development tool for implementing dynamic, irregular scientific applications, such as multilevel finite difference and particle methods, on high-performance multiple instruction multiple data (MIMD parallel architectures. It supports coarse-grain data parallelism and gives the application complete control over specifying arbitrary block decompositions. LPARX provides structural abstraction, representing data decompositions as first-class objects that can be manipulated and modified at runtime. LPARX, implemented as a C++ class library, is currently running on diverse MIMD platforms, including the Intel Paragon, Cray C-90, IBM SP2, and networks of workstations running under PVM. Software may be developed and debugged on a singe-processor workstation.

  18. Computer-Generated Experimental Designs for Irregular-Shaped Regions

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Nam K.; Piepel, Gregory F.

    2005-09-01

    This paper focuses on the construction of computer-generated designs on irregularly-shaped, constrained regions. Overviews of the Fedorov exchange algorithm (FEA) and other exchange algorithms for the construction of D-optimal designs are given. A faster implementation of the FEA is presented, which is referred to as fast-FEA (denoted FFEA). The FFEA was applied to construct D-optimal designs for several published examples with constrained experimental regions. Designs resulting from the FFEA are more D-efficient than published designs, and provide benchmarks for future comparisons of design construction algorithms. The construction of G-optimal designs for constrained regions is also discussed and illustrated with a published example.

  19. The Orbits of Jupiter’s Irregular Satellites

    Science.gov (United States)

    Brozović, Marina; Jacobson, Robert A.

    2017-04-01

    We report on the improved ephemerides for the irregular Jovian satellites. We used a combination of numerically integrated equations of motion and a weighted least-squares algorithm to fit the astrometric measurements. The orbital fits for 59 satellites are summarized in terms of state vectors, post-fit residuals, and mean orbital elements. The current data set appears to be sensitive to the mass of Himalia, which is constrained to the range of GM = 0.13–0.28 km3 s‑2. Here, GM is the product of the Newtonian constant of gravitation, G and the body's mass, M. Our analysis of the orbital uncertainties indicates that 11 out of 59 satellites are lost owing to short data arcs. The lost satellites hold provisional International Astronomical Union (IAU) designations and will likely need to be rediscovered.

  20. Irregularities of ionospheric VTEC during lightning activity over Antarctic Peninsula

    Science.gov (United States)

    Suparta, W.; Nor, W. N. A. Wan Mohd

    2017-05-01

    This paper investigates the irregularities of vertical total electron content (VTEC) during lightning activity and geomagnetic quiet days over Antarctic Peninsula in year 2014. During the lightning event, the ionosphere may be disturbed which may cause disruption in the radio signal. Thus, it is important to understand the influence of lightning on VTEC in the study of upper-lower interaction. The lightning data is obtained from World Wide Lightning Location Network (WWLLN) and the VTEC data has analyzed from Global Positioning System (GPS) for O’Higgins (OHI3), Palmer (PALV), and Rothera (ROTH). The results demonstrate the VTEC variation of ∼0.2 TECU during low lightning activity which could be caused by energy dissipation through lightning discharges from troposphere into the thermosphere.

  1. Collisional Cascade Caclulations for Irregular Satellite Swarms in Fomalhaut b

    CERN Document Server

    Kenyon, Scott J

    2015-01-01

    We describe an extensive suite of numerical calculations for the collisional evolution of irregular satellite swarms around 1--300 M-earth planets orbiting at 120 AU in the Fomalhaut system. For 10--100 M-earth planets, swarms with initial masses of roughly 1% of the planet mass have cross-sectional areas comparable to the observed cross-sectional area of Fomalhaut b. Among 30--300 M-earth planets, our calculations yield optically thick swarms of satellites for ages of 1-10 Myr. Observations with HST and ground-based AO instruments can constrain the frequency of these systems around stars in the beta Pic moving group and possibly other nearby associations of young stars.

  2. Global scale ionospheric irregularities associated with thunderstorm activity

    CERN Document Server

    Pulinets, S A

    2002-01-01

    The potential difference near 280 kV exists between ground and ionosphere. This potential difference is generated by thunderstorm discharges all over the world, and return current closes the circuit in the areas of fair weather (so-called fair weather current). The model calculations and experimental measurements clearly demonstrate non-uniform latitude-longitude distribution of electric field within the atmosphere. The recent calculations show that the strong large scale vertical atmospheric electric field can penetrate into the ionosphere and create large scale irregularities of the electron concentration. To check this the global distributions of thunderstorm activity obtained with the satellite monitoring for different seasons were compared with the global distributions of ionosphere critical frequency (which is equivalent to peak electron concentration) obtained with the help of satellite topside sounding. The similarity of the obtained global distributions clearly demonstrates the effects of thunderstor...

  3. Robust Fusion of Irregularly Sampled Data Using Adaptive Normalized Convolution

    Directory of Open Access Journals (Sweden)

    Schutte Klamer

    2006-01-01

    Full Text Available We present a novel algorithm for image fusion from irregularly sampled data. The method is based on the framework of normalized convolution (NC, in which the local signal is approximated through a projection onto a subspace. The use of polynomial basis functions in this paper makes NC equivalent to a local Taylor series expansion. Unlike the traditional framework, however, the window function of adaptive NC is adapted to local linear structures. This leads to more samples of the same modality being gathered for the analysis, which in turn improves signal-to-noise ratio and reduces diffusion across discontinuities. A robust signal certainty is also adapted to the sample intensities to minimize the influence of outliers. Excellent fusion capability of adaptive NC is demonstrated through an application of super-resolution image reconstruction.

  4. Tracking breather dynamics in irregular sea state conditions

    CERN Document Server

    Chabchoub, A

    2016-01-01

    Breather solutions of the nonlinear Schr\\"odinger equation (NLSE) are known to be considered as backbone models for extreme events in the ocean as well as in Kerr media. These exact determinisitic rogue wave (RW) prototypes on a regular background describe a wide-range of modulation instability configurations. Alternatively, oceanic or electromagnetic wave fields can be of chaotic nature and it is known that RWs may develop in such conditions as well. We report an experimental study confirming that extreme localizations in an irregular oceanic JONSWAP wave field can be tracked back to originate from exact NLSE breather solutions, such as the Peregrine breather. Numerical NLSE as well as modified NLSE simulations are both in good agreement with laboratory experiments and highlight the significance of universal weakly nonlinear evolution equations in the emergence as well as prediction of extreme events in nonlinear dispersive media.

  5. Constructing a logical, regular axis topology from an irregular topology

    Science.gov (United States)

    Faraj, Daniel A.

    2014-07-01

    Constructing a logical regular topology from an irregular topology including, for each axial dimension and recursively, for each compute node in a subcommunicator until returning to a first node: adding to a logical line of the axial dimension a neighbor specified in a nearest neighbor list; calling the added compute node; determining, by the called node, whether any neighbor in the node's nearest neighbor list is available to add to the logical line; if a neighbor in the called compute node's nearest neighbor list is available to add to the logical line, adding, by the called compute node to the logical line, any neighbor in the called compute node's nearest neighbor list for the axial dimension not already added to the logical line; and, if no neighbor in the called compute node's nearest neighbor list is available to add to the logical line, returning to the calling compute node.

  6. First Stellar Abundances in the Dwarf Irregular Galaxy IC 1613

    Science.gov (United States)

    Tautvaišienė, Gražina; Geisler, Doug; Wallerstein, George; Borissova, Jura; Bizyaev, Dmitry; Pagel, Bernard E. J.; Charbonnel, Corinne; Smith, Verne

    2007-12-01

    Chemical abundances in three M supergiants in the Local Group dwarf irregular galaxy IC 1613 have been determined using high-resolution spectra obtained with the UVES spectrograph on the ESO 8.2 m Kueyen telescope. A detailed synthetic-spectrum analysis has been used to determine the atmospheric parameters and abundances of O, Na, Mg, Al, Si, Ca, Sc, Ti, Cr, Fe, Co, Ni, La, and Eu. We find the overall metallicity of the stars to be [Fe/H] = -0.67 ± 0.09 and the age 9-13 Myr, which is in excellent agreement with the present-day values in the age-metallicity relationship model of IC 1613 by Skillman et al. We have found that the three supergiants investigated have a mean [α/Fe] equal to about -0.1, which is lower than seen in Galactic stars at the same metallicity and is in agreement with the results obtained in other dwarf irregular galaxies. The oxygen abundances are in agreement with the upper values of the nebular oxygen determinations in IC 1613. The abundance ratios of s- and r-process elements to iron are enhanced relative to solar by about 0.3 dex. The abundance pattern of the elements studied is similar to that of the Small Magellanic Cloud, except for Co and Ni, which are underabundant in the SMC. The observed elemental abundances are generally in very good agreement with the recent chemical evolution model of Yuk and Lee. Based on observations collected with the Very Large Telescope and the 2.2 m Telescope of the European Southern Observatory within the Observing Programs 70.B-0361(A) and 072.D-0113(D).

  7. How Iapetus is Painted by Saturn's Irregular Satellites

    Science.gov (United States)

    Tamayo, Dan; Burns, J. A.; Hamilton, D. P.; Hedman, M. M.

    2010-10-01

    The leading hemisphere of Iapetus, Saturn's outermost regular satellite, is ten times darker than its trailing side. To explain this unique albedo distribution, Soter (1974) proposed that collisionally generated dust from the dark outer irregular satellite Phoebe has evolved inward due to radiation forces and coated Iapetus’ leading side. The recent discovery (Verbiscer et al. 2009) of the colossal Phoebe ring between the orbits of Iapetus and Phoebe indicates that Soter's mechanism is active at some level. . To calibrate the effectiveness of this source, we follow the histories of Phoebe-ring dust under the relevant perturbations and thereby evaluate the particles’ probability of striking Iapetus, as well as the expected spatial distribution on the Iapetan surface. We find that, of the long-lived particles (those larger than 4 µm), those larger than 10 µm are virtually certain to strike Iapetus. Their calculated distribution across the surface matches well the measured albedo pattern in longitude. To explain the observed bright polar caps, our computed polar-dust-deposition rates must be overwhelmed by sublimation products from equatorial regions as proposed in the thermal runaway model of Spencer & Denk (2010); we thus constrain the latter model. We also track the dust originating from all the other known irregular moons, finding that a substantial fraction of the material from retrograde moons would eventually coat Iapetus--perhaps explaining why the spectrum of Iapetus’ dark material differs somewhat from Phoebe's (Buratti et al. 2005). We find that dust from lower-eccentricity moons with inclinations nearer 180° is more likely to strike Iapetus. . Finally, of those dust particles that do not strike Iapetus, we find that most land on Titan, with a smaller fraction hitting Hyperion. As has been previously conjectured (Burns et al. 1996), such exogenous dust, coupled with Hyperion's chaotic rotation could explain Hyperion's roughly uniform, moderate

  8. How to analyse irregularly sampled geophysical time series?

    Science.gov (United States)

    Eroglu, Deniz; Ozken, Ibrahim; Stemler, Thomas; Marwan, Norbert; Wyrwoll, Karl-Heinz; Kurths, Juergen

    2015-04-01

    One of the challenges of time series analysis is to detect dynamical changes in the dynamics of the underlying system.There are numerous methods that can be used to detect such regime changes in regular sampled times series. Here we present a new approach, that can be applied, when the time series is irregular sampled. Such data sets occur frequently in real world applications as in paleo climate proxy records. The basic idea follows Victor and Purpura [1] and considers segments of the time series. For each segment we compute the cost of transforming the segment into the following one. If the time series is from one dynamical regime the cost of transformation should be similar for each segment of the data. Dramatic changes in the cost time series indicate a change in the underlying dynamics. Any kind of analysis can be applicable to the cost time series since it is a regularly sampled time series. While recurrence plots are not the best choice for irregular sampled data with some measurement noise component, we show that a recurrence plot analysis based on the cost time series can successfully identify the changes in the dynamics of the system. We tested this method using synthetically created time series and will use these results to highlight the performance of our method. Furthermore we present our analysis of a suite of calcite and aragonite stalagmites located in the eastern Kimberley region of tropical Western Australia. This oxygen isotopic data is a proxy for the monsoon activity over the last 8,000 years. In this time series our method picks up several so far undetected changes from wet to dry in the monsoon system and therefore enables us to get a better understanding of the monsoon dynamics in the North-East of Australia over the last couple of thousand years. [1] J. D. Victor and K. P. Purpura, Network: Computation in Neural Systems 8, 127 (1997)

  9. ESA' s novel gravitational modeling of irregular planetary bodies

    Science.gov (United States)

    Ortega, Guillermo

    A detailed understanding and modeling of the gravitational modeling is required for realistic investigation of the dynamics of orbits close to irregularly shaped bodies. Gravity field modelling up to a certain maximum spherical harmonic degree N involves N2 unkown spherical harmonic coefficients or complex harmonics. The corresponding number of matrix entries reaches till N4 . For missions like CHAMP, GRACE or GOCE, the maximum degree of resolution is 75, 150 and 300 respectively. Therefore, the number of unknowns for a satellite like GOCE will be around 100.000. Since these missions usually fly for a period of time of several years, the number of observations is huge. Hence, gravity field recovery from these missions is a high demanding task. The classical approaches like spherical expansion of the potential lead generally to a high number of coefficients, which reduce the software computational efficiency of the orbit propagation and which have mostly a limited physical meaning. One of the main targets of the activity is the modelling of asteroids, small moons, and cometary bodies. All celestial bodies are irregular by definition. However, the scope of the activity is broad enough as to be able to use the models and the software in quasy-regular bodies as well. Therefore the models and tools could be used for bodies such as the Moon, Mars, Venus, Deimos, Europa, Eros, Mathilda, and Churyumov-Gerasimenko, etc., being these applications relevant for scientific (Rosetta, Bepi Colombo), exploration (Exo-Mars), NEO mitigation (Don Quijote) and Earth observation (GOCE) missions of ESA.

  10. Efficient Clustering for Irregular Geometries Based on Identification of Concavities

    Directory of Open Access Journals (Sweden)

    Velázquez-Villegas Fernando

    2014-04-01

    Full Text Available Two dimensional clustering problem has much relevance in applications related to the efficient use of raw material, such as cutting stock, packing, etc. This is a very complex problem in which multiple bodies are accommodated efficiently in a way that they occupy as little space as possible. The complexity of the problem increases with the complexity of the bodies. Clearly the number of possible arrangements between bodies is huge. No Fit Polygon (NFP allows to determine the entire relative positions between two patterns (regular or irregular in contact, non-overlapping, therefore the best position can be selected. However, NFP generation requires a lot of calculations; besides, selecting the best cluster isn’t a simple task because, between two irregular patterns in contact, hollows (unusable areas and external concavities (usable areas can be produced. This work presents a quick and simple method to reduce calculations associated with NFP generation and to minimize unusable areas in a cluster. This method consists of generating partial NFP, just on concave regions of the patterns, and selecting the best cluster using a total weighted efficiency, i.e. a weighted value of enclosure efficiency (ratio of occupied area on convex hull area and hollow efficiency (ratio of occupied area on cluster area. The proposed method produces similar results as those obtained by other methods; however the shape of the clusters obtained allows to accommodate more parts in similar spaces, which is a desirable result when it comes to optimizing the use of material. We present two examples to show the performance of the proposal.

  11. Road density

    Data.gov (United States)

    U.S. Environmental Protection Agency — Road density is generally highly correlated with amount of developed land cover. High road densities usually indicate high levels of ecological disturbance. More...

  12. Time-frequency processing of track irregularities in high-speed train

    Science.gov (United States)

    Ning, Jing; Lin, Jianhui; Zhang, Bing

    2016-01-01

    Track irregularities are the main source of vehicle vibration. With the increase in the speed, the track irregularities have become a more significant issue of concerned. The axle box acceleration signals can be obtained for analyzing the track irregularities, but the signals are usually non-stationary and signal processing results are not normally satisfied with the ordinary way. Thus, time-frequency distribution analysis is proposed to use in this study. To minimize the cross-terms, a new method based on Empirical Mode Decomposition (EMD) and Cohen's class distribution has been developed and advanced. This approach has been tested with three typical simulation signals and then applied to analyze the track irregularities. The result is consistent with the result from track inspection cars. This indicates this new algorithm is suitable for analyzing the track irregularities. It can be applied in rail irregularity measurement to compensate some shortages of the track inspection cars.

  13. Human Rights of Irregular Immigrants: A Challenge for the Universality of Human Rights

    OpenAIRE

    Luljeta Ikonomi

    2013-01-01

    Irregular immigration is a phenomenon with a substantial impact for the majority of the countries. The paper analyses whether there is an adequate human rights framework for protection of irregular immigrants or whether the irregular status exempts the migrants from the protection of international human rights law. If this is the case, then the human rights universality has failed. The paper takes into consideration the developments in the International and EU Law, as well as in the jurisprud...

  14. Application of generalized separation of variables to solving mixed problems with irregular boundary conditions

    Science.gov (United States)

    Gasymov, E. A.; Guseinova, A. O.; Gasanova, U. N.

    2016-07-01

    One of the methods for solving mixed problems is the classical separation of variables (the Fourier method). If the boundary conditions of the mixed problem are irregular, this method, generally speaking, is not applicable. In the present paper, a generalized separation of variables and a way of application of this method to solving some mixed problems with irregular boundary conditions are proposed. Analytical representation of the solution to this irregular mixed problem is obtained.

  15. The spatially resolved Kennicutt-Schmidt relation in the HI dominated regions of spiral and dwarf irregular galaxies

    CERN Document Server

    Roychowdhury, Sambit; Kauffmann, Guinevere; Wang, Jing; Chengalur, Jayaram N

    2015-01-01

    We study the Kennicutt-Schmidt relation between average star formation rate and average cold gas surface density in the Hi dominated ISM of nearby spiral and dwarf irregular galaxies. We divide the galaxies into grid cells varying from sub-kpc to tens of kpc in size. Grid-cell measurements of low SFRs using H-alpha emission can be biased and scatter may be introduced because of non-uniform sampling of the IMF or because of stochastically varying star formation. In order to alleviate these issues, we use far-ultraviolet emission to trace SFR, and we sum up the fluxes from different bins with the same gas surface density to calculate the average $\\Sigma_{SFR}$ at a given value of $\\Sigma_{gas}$. We study the resulting Kennicutt-Schmidt relation in 400 pc, 1 kpc and 10 kpc scale grids in nearby massive spirals and in 400 pc scale grids in nearby faint dwarf irregulars. We find a relation with a power law slope of 1.5 in the HI-dominated regions for both kinds of galaxies. The relation is offset towards longer ga...

  16. Simple approximation method for determining field factors and tissue-peap ratios of irregularly shaped fields

    Energy Technology Data Exchange (ETDEWEB)

    Araki, Fujio; Kumagai, Kozo; Iseri, Takumi; Kawano, Tsutomu (National Hospital of Kumamoto (Japan))

    1991-04-01

    Dose calculation of irregularly shaped fields can be made by the Clarkson technique, which however requires considerable time and is thus not practical. We investigated a simple approximation method for determining field factors (F{sub A}) and tissue-peak ratios (TPRs) for irregularly shaped fields. By this method, we approximated scatter dose by the ratio of area for an irregularly shaped field to that for the overall field (without blocking). Maximum error of equivalent square fields as determined by this method for irregularly shaped fields was -1.3% for field factors, +2.1% for TPRs and +1.4% for the F{sub A} x TPRs. (author).

  17. Characterization of irregular seeds on gibbsites precipitated from caustic aluminate solutions

    Institute of Scientific and Technical Information of China (English)

    CHEN Guo-hui; CHEN Qi-yuan; YIN Zhou-lan; YIN Zhi-min

    2006-01-01

    The irregular surface of seeds on which gibbsites are precipitated from caustic aluminate solutions, was investigated according to the fractal theory. Two kinds of fractal dimensions were used to characterize these irregularity. Box-dimension and spectral dimension are based on the SEM images of seeds and diffusive dynamic equation ofthe precipitation respectively. Both these two dimensions are affected by the reaction temperature, evolved with different reaction conditions and can reflect the influence of irregularity of seeds on the precipitation rate. Box dimension is fit for the characterization of the irregular morphology of seeds, while spectral dimension can explain the fractal dynamic behavior.

  18. Diagnosability issues in multiprocessor systems

    Energy Technology Data Exchange (ETDEWEB)

    Raghavan, V.

    1989-01-01

    In a seminal paper on fault diagnosis, Preparata, Metze, and Chien introduced a graph-theoretical model. Barsi, Grandoni, and Maestrini relaxed some constraints in this model to create a different model for fault diagnosis. Both these models have become the subject of intense research in the past two decades. A major open problem for these models is the question of sequential t-diagnosability-Given an arbitrary system of units and that there are no more than t faulty units in it, can we always identify at least one faulty unit The author shows that this problem is co-NP complete in both models. Recent research has shown that there are polynomial time algorithms to find the maximum number of faulty units a system can withstand and still identify all of them from a single collection of test results. He presents improved algorithms to solve this problem in both models. Using the letters n,m, and {tau} to denote the number of units, the number of tests, and the maximum number of faulty units respectively, our results can be summarized as follows: in the model of Barsi, Grandoni, and Maestrini, the algorithm has a time complexity of O(n{tau}{sup 2}/log{tau}) improving on the currently known O(n{tau}{sup 2}); in the model of Preparata, Metze, and Chien, the algorithm has a complexity of O(n{tau}{sup 2.5}) improving on the currently known O(mn{sup 1.5}). He also presents related results in the latter model, which suggest the possibility of reducing the complexity even further. Finally, he develops a general scheme for characterizing diagnosable systems. Using this scheme, he solves the open problem of characterizing t/s and sequentially t-diagnosable systems. The characterizations are then used to rederive some known results.

  19. How to diagnose acute appendicitis

    DEFF Research Database (Denmark)

    Mostbeck, Gerhard; Adam, E Jane; Nielsen, Michael Bachmann;

    2016-01-01

    Acute appendicitis (AA) is a common abdominal emergency with a lifetime prevalence of about 7 %. As the clinical diagnosis of AA remains a challenge to emergency physicians and surgeons, imaging modalities have gained major importance in the diagnostic work-up of patients with suspected AA in order...... appendicitis (AA). • Primary US for AA diagnosis will decrease ionizing radiation and cost. • Sensitivity of US to diagnose AA is lower than of CT/MRI. • Non-visualization of the appendix should lead to clinical reassessment. • Complementary MRI or CT may be performed if diagnosis remains unclear....

  20. Storm Signatures and Irregularities in the Equatorial Ionosphere Observed by Using FORMOSAT-3/COSMIC (Invited)

    Science.gov (United States)

    Liu, J. G.; Chen, L.; Hsu, R.; Lee, I.; Chang, G.; Yu, S.; Liu, T.

    2013-12-01

    This paper reports that fluctuations in the vertical electron density triggering by magnetic storms and irregularities of S4 scintillations in the equatorial ionosphere probed by FORMOSAT-3/COSMIC (F3/C). For the storm study, the electron density profiles derived by the F3/C RO (radio occultation) in high-, mid- and low-latitudes during the quiet time and disturbed periods are subdivided into four sectors, noon, dusk, midnight, and dawn, to find wavy characteristics. The wavelet transformation is further applied to examine the profiles before and during the storm period. Above 300km, the ionosphere becomes very structured, and the amplitude in fluctuations of 15~30km wavelength significantly enhances during the storm period, especially high latitude region. The concurrence in changes of the geomagnetic index and the ionospheric density suggest that penetration electric fields and energy inputs at high latitudes play important roles. On the other hand, the F3/C RO provides an excellent opportunity to monitor three-dimensional structures and dynamics of the ionospheric scintillations during the low solar activity year of 2007-2013. Measurements of the global F3/C S4 index are subdivided and examined in various latitudes, longitudes, altitudes, and seasons. The F-region scintillations in the equatorial and low-latitude ionosphere start around post-sunset period and often persist till post-midnight hours (0300 MLT, magnetic local time) during the March and September equinox as well as December Solstice seasons. The E-region scintillations reveal a clear solar zenith effect and yield pronounced intensities in mid-latitudes during the Summer Solstice seasons, which are well correlated with occurrences of the sporadic E-layer. Finally, impact of the F3/C follow-on, FORMOSAT-7/COSMIC-2, mission on ionospheric space weather monitoring will be briefed.

  1. Irregularities in Pump-Induced Tilt Above Shallow Aquifers

    Science.gov (United States)

    Kuempel, H. J.; Fabian, M.

    2003-12-01

    Near surface ground tilt induced by the extraction of fluids from subsurface reservoirs has repeatedly been used to constrain reservoir parameters. In general, pump-induced tilt is found to be proportional in strength to the pore pressure gradient created by the pumping, to be a function of poroelastic rock parameters, and to depend on the geometric configuration of the tilt sensor and the productive sections of a well. Assuming radial flow, the strike of the tilt signal should point toward the productive well. However, inversion of near surface tilt can be hampered through irregularities in the pump-induced signal and suffer from insufficient knowledge of the influence of heterogeneities in the subsoil, either within or above the reservoir. We can learn more about the impact of such heterogeneities and reduce ambiguities by analyzing case studies. New observational data from 3 test sites in Germany confirm that a variety of causes can produce irregularities in pump-induced surface deformation, namely: (1) The strike of a tilt signal can considerably deviate from the direction toward the active well. A reason could be that the steepest effective pore pressure gradient builds up in another than radial direction (thereby generating anisotropic fluid flow). Accordingly, tilt hodographs for a complete pump cycle may be elliptic rather than follow a line. (2) The normal rule of how the signal strength depends on the horizontal and the vertical distance may be violated. Structural heterogeneities in the subsurface are the most likely cause for this behaviour. (3) Recovery of the induced tilt signal following the cessation of pumping can be incomplete. This could indicate a non-reversible compaction possibly due to overexploitation of a reservoir. (4) A transient sign reversal of ground tilt may occur during the build-up phase of the signal. This feature could be an analogue to the so-called Noordbergum effect occasionally seen in the response of well levels at locations

  2. Reconstructing regional climate networks from irregularly sampled satellite data

    Science.gov (United States)

    Wiedermann, Marc; Donner, Reik V.; Sykioti, Olga; Papadimitriou, Constantinos; Kurths, Jürgen

    2015-04-01

    With the increasing availability of remote sensing data Earth System Analysis has taken a great step forward. Satellite data with high resolution in time and space allow for an in-depth analysis of small-scale processes in the climate as well as ecosystems. This data type, however, also harbors crucial conceptual complications. First, depending on whether the satellite is orbiting on an ascending or descending path systematic biases are induced into the dataset and both measurements can not be evaluated simultaneously without an appropriate preprocessing. Second, remote sensing data are usually not produced with equidistant temporal sampling, but might contain huge gaps, due to cloud cover or maintenance work and irregular time steps, due to the orbiting time of the satellite. In this work, we utilize sea surface temperature (SST) data obtained from the SMOS satellite as part of ESA's Earth Explorer Mission to study small-scale regional interactions between different parts of the Mediterranean, Aegean and Black Sea. In a first step, we create homogeneous time series for each grid point by combining data from ascending and descending satellite paths by utilizing principal component and singular spectrum analysis. To address the issue of irregular temporal sampling we utilize a kernel weighted version of the linear cross-correlation function to compute lagged correlations between all pairs of grid points in the dataset. By setting a threshold to the thus obtained correlation matrix we obtain a binary matrix which can be interpreted as the adjacency matrix of a complex network. We then use tools from complex network theory to study regional interdependencies in the study area for different time lags of up to forty days. We find that the obtained networks represent well the observed average wind directions and speeds and display interaction structures between small regions in the Aegean Sea, which are in good agreement with earlier observations. The methods presented

  3. Regional climate network analysis from irregularly sampled satellite data

    Science.gov (United States)

    Wiedermann, Marc; Sykioti, Olga; Papadimitriou, Constantinos; Balasis, George; Kurths, Jürgen; Donner, Reik V.

    2016-04-01

    With the increasing availability of remote sensing data Earth System Analysis has taken a great step forward. This type of data, however, also harbors a variety of conceptual complications. First, depending on whether the satellite is orbiting on an ascending or descending path systematic biases are induced into the data, and both measurements cannot be evaluated simultaneously without an appropriate preprocessing. Second, remote sensing data are usually not produced with equidistant temporal sampling, but might contain huge gaps and irregular time steps. Third, the time period covered by the data is often too short to perform an appropriate seasonal detrending. Here, we propose a general framework to create homogeneous anomalized time series for a (multivariate) satellite data set by combining time series from ascending and descending satellite paths or even different missions using principal component and singular spectrum analysis. We then exemplarily apply our method to sea surface temperature data obtained from the SMOS satellite mission to study small-scale regional correlative patterns covering different parts of the Aegean Sea. To address the issue of irregular temporal sampling we utilize a kernel weighted version of the linear cross-correlation function to compute lagged correlations between all pairs of grid points in the data set. By binarizing the thus obtained matrices, we obtain a network representation of the system's similarity structure. Ultimately, we use tools from complex network theory to study regional interdependencies in the study area for different time lags of up to forty days. We find that the obtained networks represent well the observed average wind directions and speeds and display interaction structures between small regions in the Aegean Sea, which are in good agreement with earlier observations. In a second step, we extend the study area to the whole Mediterranean and Black Sea and investigate lagged interactions between these two

  4. Representation of the Gravity Field of Irregularly Shaped Bodies

    Science.gov (United States)

    Reimond, Stefan; Baur, Oliver

    2015-04-01

    Exploratory space missions to small bodies in our solar system have gained importance over the last few decades. The well-renowned mission Rosetta set a milestone in space science history when it successfully lowered its mini-lab Philae onto the surface of Comet 67P/Churyumov-Gerasimenko in November 2014. Knowledge of the gravitational field of a small body, e.g. a comet or asteroid, is crucial in order to study a spacecraft's motion in its environment and to infer geophysical properties. Traditionally, the gravitational field of a body is modeled by means of spherical harmonics. For bodies of near-spherical shape (such as the Earth), this is an adequate method, because the reference figure, i.e. a sphere, snugly fits the body. For irregularly shaped bodies, however, the adoption of spherical harmonics might be a sub-optimal choice. As an alternative, oblate or prolate spheroidal harmonics (OH or PH, reference figure is an ellipsoid of revolution) or ellipsoidal harmonics (EH, reference figure is a tri-axial ellipsoid) should be considered. The latter will in general be the best choice in terms of aptness of the reference figure. The downside of EH, however, lies in the considerably increased (numerical) complexity of the computation of the base functions, i.e., the Lamé functions of the first and second kind. OH or PH represent a promising path down the middle. Elongated bodies (such as Asteroid 433 Eros) are often similarly well approximated by a prolate spheroid as by the corresponding tri-axial ellipsoid. Contracted bodies, on the other hand, can be described accordingly well by means of an oblate spheroid. We compare the SH, OH, PH and EH gravitational field parameterizations for different celestial bodies, including Rosetta's target comet 67P. The tasks are as follows: Based on the polyhedral representation of a body's shape model, the gravitational potential and acceleration vector is computed for evenly or irregularly distributed points inside or outside

  5. Distal DVT: worth diagnosing? Yes.

    Science.gov (United States)

    Schellong, S M

    2007-07-01

    Much of the argument for or against diagnosis of distal deep vain thrombosis (DVT) depends on the extra effort that has to be spent on it. This review presents the data on ultrasound of paired calf veins and calf muscle veins (distal ultrasound) in terms of protocols, feasibility, reliability and expected findings. In summary, provided there is adequate and anatomically sound training of sonographers, distal ultrasound is a valid, 4-minute procedure, which can easily be added to the examination of proximal veins. The second part of the review refers to the pathophysiology of ascending DVT, which is the most common type. Adequate patient care in terms of benefit, harm and cost includes a single non-invasive examination followed by risk adopted treatment allocation. This concept ideally should be valid for any type of DVT. The data extending this concept to distal DVT can only be derived from studies that look closely at this entity (i.e. in fact diagnose distal DVT). Even before these data are available, diagnosing distal DVT at least doubles the number of symptomatic patients in which signs and symptoms can be ascribed to a definitive diagnosis, which in itself is a benefit for patient care.

  6. DIAGNOSING THE READINES OF TECHNICAL UNIVERSITY STUDENTS FOR RESEARCH ACTIVITIES

    Directory of Open Access Journals (Sweden)

    M. A. Fedorova

    2014-01-01

    Full Text Available The paper is devoted to the technique designed for diagnosing the technical university student’s readiness for research activities that is closely related to the research competence structure. Based on the survey results and literature analysis, the authors considered ten primary components of the readiness in question, and analyzed each component along with the corresponding weight value, mean value, and probability density. Consequently, the high level of academic knowledge and motivation for research activity were singled out as the priority components. The paper describes the linear mathematical model, developed for diagnosing student’s readiness for research activities, and presents the minimum, maximum and threshold values of diagnostic assessments, and the relating indicators. The given model can be used as the basic one for developing a test software product for students and research supervisors diagnosing the readiness for research activity

  7. Measuring Performance and Effectiveness in Irregular Warfare: Preventing Dysfunctional Behavior

    Science.gov (United States)

    2009-05-04

    behavior, it will also support operational commanders in diagnosing problems, making critical decisions, fostering learning, adjusting strategies , and...the area where Netflix continues to dominate…Blockbuster is doomed.” 11 While bottom line figures such as monthly earnings are important, unless...how to adapt and manage its metrics to better support its strategy . The reality of a measurement failure has grave consequences for the military

  8. Lung density

    DEFF Research Database (Denmark)

    Garnett, E S; Webber, C E; Coates, G

    1977-01-01

    The density of a defined volume of the human lung can be measured in vivo by a new noninvasive technique. A beam of gamma-rays is directed at the lung and, by measuring the scattered gamma-rays, lung density is calculated. The density in the lower lobe of the right lung in normal man during quiet...... breathing in the sitting position ranged from 0.25 to 0.37 g.cm-3. Subnormal values were found in patients with emphsema. In patients with pulmonary congestion and edema, lung density values ranged from 0.33 to 0.93 g.cm-3. The lung density measurement correlated well with the findings in chest radiographs...... but the lung density values were more sensitive indices. This was particularly evident in serial observations of individual patients....

  9. Contrast-enhanced ultrasonography to diagnose complicated acute cholecystitis.

    Science.gov (United States)

    Sagrini, Elisabetta; Pecorelli, Anna; Pettinari, Irene; Cucchetti, Alessandro; Stefanini, Federico; Bolondi, Luigi; Piscaglia, Fabio

    2016-02-01

    Gangrenous cholecystitis and perforation are severe complications of acute cholecystitis, which have a challenging preoperative diagnosis. Early identification allows better surgical management. Contrast-enhanced computed tomography (ceCT) is the current diagnostic gold standard. Contrast-enhanced ultrasonography (CEUS) is a promising tool for the diagnosis of gallbladder perforation, but data from the literature concerning efficacy are sparse. The aim of the study was to evaluate CEUS findings in pathologically proven complicated cholecystitis (gangrenous, perforated gallbladder, pericholecystic abscess). A total of 8 patients submitted to preoperative CEUS, and with subsequent proven acute complicated cholecystitis at surgical inspection and pathological analysis, were retrospectively identified. The final diagnosis was gangrenous/phlegmonous cholecystitis (n. 2), phlegmonous/ulcerative changes plus pericholecystic abscess (n. 2), perforated plus pericholecystic abscess (n. 3), or perforated plus pericholecystic biliary collection (n. 1). Conventional US findings revealed irregularly thickened gallbladder walls in all 8 patients, with vaguely defined walls in 7 patients, four of whom also had striated wall thickening. CEUS revealed irregular enhancing gallbladder walls in all patients. A distinct wall defect was seen in six patients, confirmed as gangrenous/phlegmonous cholecystitis at pathology in all six, and in four as perforation at macroscopic surgical inspection. CEUS is a non-invasive easily repeatable technique that can be performed at the bedside, and is able to accurately diagnose complicated/perforated cholecystitis. Despite the limited sample size in the present case series, CEUS appears as a promising tool for the management of patients with the clinical possibility of having an acute complicated cholecystitis.

  10. Response reduction factor of irregular RC buildings in Kathmandu valley

    Science.gov (United States)

    Chaulagain, Hemchandra; Rodrigues, Hugo; Spacone, Enrico; Guragain, Ramesh; Mallik, Radhakrishna; Varum, Humberto

    2014-09-01

    Most current seismic design includes the nonlinear response of a structure through a response reduction factor ( R). This allows the designer to use a linear elastic force-based approach while accounting for nonlinear behavior and deformation limits. In fact, the response reduction factor is used in modern seismic codes to scale down the elastic response of a structure. This study focuses on estimating the actual ` R' value for engineered design/construction of reinforced concrete (RC) buildings in Kathmandu valley. The ductility and overstrength of representative RC buildings in Kathmandu are investigated. Nonlinear pushover analysis was performed on structural models in order to evaluate the seismic performance of buildings. Twelve representative engineered irregular buildings with a variety of characteristics located in the Kathmandu valley were selected and studied. Furthermore, the effects of overstrength on the ductility factor, beam column capacity ratio on the building ductility, and load path on the response reduction factor, are examined. Finally, the results are further analyzed and compared with different structural parameters of the buildings.

  11. Non-linear analysis of vibrations of irregular plates

    Science.gov (United States)

    Lobitz, D. W.; Nayfeh, A. H.; Mook, D. T.

    1977-01-01

    A numerical perturbation method is used to investigate the forced vibrations of irregular plates. Nonlinear terms associated with the midplane stretching are retained in the analysis. The numerical part of the method involves the use of linear, finite element techniques to determine the free oscillation mode shapes and frequencies and to obtain the linear midplane stress resultants caused by the midplane stretching. Representing the solution as an expansion in terms of these linear mode shapes, these modes and the resultants are used to determine the equations governing the time-dependent coefficients of this expansion. These equations are solved by using the method of multiple scales. Specific solutions are given for the main-resonant vibrations of an elliptical plate in the presence of internal resonances. The results indicate that modes other than the driven mode can be drawn into the steady state response. Though the excitation is composed of a single harmonic, the response may not be periodic. Moreover, the particular types of responses that can occur are highly dependent on the mode being excited and are sensitive to small geometrical changes.

  12. New OpenMP Directives for Irregular Data Access Loops

    Directory of Open Access Journals (Sweden)

    J. Labarta

    2001-01-01

    Full Text Available Many scientific applications involve array operations that are sparse in nature, ie array elements depend on the values of relatively few elements of the same or another array. When parallelised in the shared-memory model, there are often inter-thread dependencies which require that the individual array updates are protected in some way. Possible strategies include protecting all the updates, or having each thread compute local temporary results which are then combined globally across threads. However, for the extremely common situation of sparse array access, neither of these approaches is particularly efficient. The key point is that data access patterns usually remain constant for a long time, so it is possible to use an inspector/executor approach. When the sparse operation is first encountered, the access pattern is inspected to identify those updates which have potential inter-thread dependencies. Whenever the code is actually executed, only these selected updates are protected. We propose a new OpenMP clause, indirect, for parallel loops that have irregular data access patterns. This is trivial to implement in a conforming way by protecting every array update, but also allows for an inspector/executor compiler implementation which will be more efficient in sparse cases. We describe efficient compiler implementation strategies for the new directive. We also present timings from the kernels of a Discrete Element Modelling application and a Finite Element code where the inspector/executor approach is used. The results demonstrate that the method can be extremely efficient in practice.

  13. Mechanically Milled Irregular Zinc Nanoparticles for Printable Bioresorbable Electronics.

    Science.gov (United States)

    Mahajan, Bikram K; Yu, Xiaowei; Shou, Wan; Pan, Heng; Huang, Xian

    2017-02-20

    Bioresorbable electronics is predominantly realized by complex and time-consuming anhydrous fabrication processes. New technology explores printable methods using inks containing micro- or nano-bioresorbable particles (e.g., Zn and Mg). However, these particles have seldom been obtained in the context of bioresorbable electronics using cheap, reliable, and effective approaches with limited study on properties essential to printable electronics. Here, irregular nanocrystalline Zn with controllable sizes and optimized electrical performance is obtained through ball milling approach using polyvinylpyrrolidone (PVP) as a process control agent to stabilize Zn particles and prevent cold welding. Time and PVP dependence of the ball milled particles are studied with systematic characterizations of morphology and composition of the nanoparticles. The results reveal crystallized Zn nanoparticles with a size of ≈34.834 ± 1.76 nm and low surface oxidation. The resulting Zn nanoparticles can be readily printed onto bioresorbable substrates and sintered at room temperature using a photonic sintering approach, leading to a high conductivity of 44 643 S m(-1) for printable zinc nanoparticles. The techniques to obtain Zn nanoparticles through ball milling and processing them through photonic sintering may potentially lead to a mass fabrication method for bioresorbable electronics and promote its applications in healthcare, environmental protection, and consumer electronics.

  14. Irregular topography at the Earth’s inner core boundary

    Science.gov (United States)

    Dai, Zhiyang; Wang, Wei; Wen, Lianxing

    2012-01-01

    Compressional seismic wave reflected off the Earth’s inner core boundary (ICB) from earthquakes occurring in the Banda Sea and recorded at the Hi-net stations in Japan exhibits significant variations in travel time (from -2 to 2.5 s) and amplitude (with a factor of more than 4) across the seismic array. Such variations indicate that Earth’s ICB is irregular, with a combination of at least two scales of topography: a height variation of 14 km changing within a lateral distance of no more than 6 km, and a height variation of 4–8 km with a lateral length scale of 2–4 km. The characteristics of the ICB topography indicate that small-scale variations of temperature and/or core composition exist near the ICB, and/or the ICB topographic surface is being deformed by small-scale forces out of its thermocompositional equilibrium position and is metastable. PMID:22547788

  15. Climatic irregular staircases: generalized acceleration of global warming.

    Science.gov (United States)

    De Saedeleer, Bernard

    2016-01-27

    Global warming rates mentioned in the literature are often restricted to a couple of arbitrary periods of time, or of isolated values of the starting year, lacking a global view. In this study, we perform on the contrary an exhaustive parametric analysis of the NASA GISS LOTI data, and also of the HadCRUT4 data. The starting year systematically varies between 1880 and 2002, and the averaging period from 5 to 30 yr - not only decades; the ending year also varies . In this way, we uncover a whole unexplored space of values for the global warming rate, and access the full picture. Additionally, stairstep averaging and linear least squares fitting to determine climatic trends have been sofar exclusive. We propose here an original hybrid method which combines both approaches in order to derive a new type of climatic trend. We find that there is an overall acceleration of the global warming whatever the value of the averaging period, and that 99.9% of the 3029 Earth's climatic irregular staircases are rising. Graphical evidence is also given that choosing an El Niño year as starting year gives lower global warming rates - except if there is a volcanic cooling in parallel. Our rates agree and generalize several results mentioned in the literature.

  16. Research of CRP-based irregular 2D seismic acquisition

    Institute of Scientific and Technical Information of China (English)

    Zhao Hu; Yin Cheng; He Guang-Ming; Chen Ai-Ping; Jing Long-Jiang

    2015-01-01

    Seismic exploration in the mountainous areas of western Chinese is extremely diffi cult because of the complexity of the surface and subsurface, which results in shooting difficulties, seismic data with low signal-to-noise ratio, and strong interference. The complexity of the subsurface structure leads to strong scattering of the refl ection points; thus, the curved-line acquisition method has been used. However, the actual subsurface structural characteristics have been rarely considered. We propose a design method for irregular acquisition based on common refl ection points (CRP) to avoid diffi cult-to-shoot areas, while considering the structural characteristics and CRP positions and optimizing the surface-receiving line position. We arrange the positions of the receiving points to ensure as little dispersion of subsurface CRP as possible to improve the signal-to-noise ratio of the seismic data. We verify the applicability of the method using actual data from a site in Sichuan Basin. The proposed method apparently solves the problem of seismic data acquisition and facilitates seismic exploration in structurally complex areas.

  17. Climatic irregular staircases: generalized acceleration of global warming

    Science.gov (United States)

    de Saedeleer, Bernard

    2016-01-01

    Global warming rates mentioned in the literature are often restricted to a couple of arbitrary periods of time, or of isolated values of the starting year, lacking a global view. In this study, we perform on the contrary an exhaustive parametric analysis of the NASA GISS LOTI data, and also of the HadCRUT4 data. The starting year systematically varies between 1880 and 2002, and the averaging period from 5 to 30 yr — not only decades; the ending year also varies . In this way, we uncover a whole unexplored space of values for the global warming rate, and access the full picture. Additionally, stairstep averaging and linear least squares fitting to determine climatic trends have been sofar exclusive. We propose here an original hybrid method which combines both approaches in order to derive a new type of climatic trend. We find that there is an overall acceleration of the global warming whatever the value of the averaging period, and that 99.9% of the 3029 Earth’s climatic irregular staircases are rising. Graphical evidence is also given that choosing an El Niño year as starting year gives lower global warming rates — except if there is a volcanic cooling in parallel. Our rates agree and generalize several results mentioned in the literature.

  18. FIGGS2: An HI survey of extremely faint irregular galaxies

    CERN Document Server

    Patra, Narendra Nath; Karachentsev, Igor D; Sharina, Margarita E

    2016-01-01

    We present the observations and first results from the FIGGS2 survey. FIGGS2 is an extension of the earlier Faint Irregular Galaxies GMRT survey (FIGGS) towards faint luminosity end. The sample consists of 20 galaxies of which 15 were detected in HI 21cm line using the Giant Meter-wave Radio Telescope (GMRT). The median blue band magnitude of our sample is ~ -11.6, which is more than one magnitude fainter than earlier FIGGS survey. From our GMRT observations we find that, for many of our sample galaxies, the HI disks are offset from their optical disks. The HI diameters of the FIGGS2 galaxies show a tight correlation with their HI mass. The slope of the correlation is 2.08 +/- 0.20 similar to what is found for FIGGS galaxies. We also find that for almost all galaxies, the HI disks are larger than the optical disks which is a common trend for dwarf or spiral galaxies. The mean value of the ratio of HI to optical diameter is ~ 1.54.

  19. Irregular persistent activity induced by synaptic excitatory feedback

    Directory of Open Access Journals (Sweden)

    Francesca Barbieri

    2007-11-01

    Full Text Available Neurophysiological experiments on monkeys have reported highly irregular persistent activity during the performance of an oculomotor delayed-response task. These experiments show that during the delay period the coefficient of variation (CV of interspike intervals (ISI of prefrontal neurons is above 1, on average, and larger than during the fixation period. In the present paper, we show that this feature can be reproduced in a network in which persistent activity is induced by excitatory feedback, provided that (i the post-spike reset is close enough to threshold , (ii synaptic efficacies are a non-linear function of the pre-synaptic firing rate. Non-linearity between presynaptic rate and effective synaptic strength is implemented by a standard short-term depression mechanism (STD. First, we consider the simplest possible network with excitatory feedback: a fully connected homogeneous network of excitatory leaky integrate-and-fire neurons, using both numerical simulations and analytical techniques. The results are then confirmed in a network with selective excitatory neurons and inhibition. In both the cases there is a large range of values of the synaptic efficacies for which the statistics of firing of single cells is similar to experimental data.

  20. Measuring border irregularities of skin lesions using fractal dimensions

    Science.gov (United States)

    Ng, Vincent T. Y.; Lee, Tim K.

    1996-09-01

    Malignant melanoma is the most common cancer in people less than 35 years of age and incident rates are increasing by approximately 5 percent per annum in many white populations, including British Columbia, Canada. In 1994, a clinical study has been established to digitize melanocytic lesions under a controlled environment. Lesions are digitized from patients who are referred to the Colored Pigment Lesion Clinic in the University of British Columbia. In this paper, we investigate how to use fractal dimensions (FDs) in measuring the irregularity of a skin lesion. In a previous project, we have experimented with 6 different methods to calculate fractal dimensions on a small number of images of skin lesions, and the simple box-counting method performed the best. However, the method did not exploit the intensity information of the images. With the new set of images which are digitized under the controlled environment, we utilize the differential box counting method to exploit such information. Four FD measures, including the direct FD, the horizontal and the vertical smoothing FDs, and the multi- fractal dimension of order two, are calculated based on the original color images. In addition, these 4 FD features are repeatedly calculate for the blue band of the images. This paper reports the different features through the calculations of the fractal dimensions and compares their differentiation power in the use of diagnosis of images of skin lesions.

  1. Irregular topography at the Earth's inner core boundary.

    Science.gov (United States)

    Dai, Zhiyang; Wang, Wei; Wen, Lianxing

    2012-05-15

    Compressional seismic wave reflected off the Earth's inner core boundary (ICB) from earthquakes occurring in the Banda Sea and recorded at the Hi-net stations in Japan exhibits significant variations in travel time (from -2 to 2.5 s) and amplitude (with a factor of more than 4) across the seismic array. Such variations indicate that Earth's ICB is irregular, with a combination of at least two scales of topography: a height variation of 14 km changing within a lateral distance of no more than 6 km, and a height variation of 4-8 km with a lateral length scale of 2-4 km. The characteristics of the ICB topography indicate that small-scale variations of temperature and/or core composition exist near the ICB, and/or the ICB topographic surface is being deformed by small-scale forces out of its thermocompositional equilibrium position and is metastable.

  2. Influence of Ionospheric Irregularities on GNSS Remote Sensing

    Directory of Open Access Journals (Sweden)

    M. V. Tinin

    2015-01-01

    Full Text Available We have used numerical simulation to study the effects of ionospheric irregularities on accuracy of global navigation satellite system (GNSS measurements, using ionosphere-free (in atmospheric research and geometry-free (in ionospheric research dual-frequency phase combinations. It is known that elimination of these effects from multifrequency GNSS measurements is handi-capped by diffraction effects during signal propagation through turbulent ionospheric plasma with the inner scale being smaller than the Fresnel radius. We demonstrated the possibility of reducing the residual ionospheric error in dual-frequency GNSS remote sensing in ionosphere-free combination by Fresnel inversion. The inversion parameter, the distance to the virtual screen, may be selected from the minimum of amplitude fluctuations. This suggests the possibility of improving the accuracy of GNSS remote sensing in meteorology. In the study of ionospheric disturbances with the aid of geometry-free combination, the Fresnel inversion eliminates only the third-order error. To eliminate the random TEC component which, like the measured average TEC, is the first-order correction, we should use temporal filtering (averaging.

  3. Thick film traps with an irregular film. Preparation and evaluation.

    Science.gov (United States)

    Kloskowski, Adam; Pettersson, Johan; Roeraade, Johan

    2004-05-07

    A new method for preparation of sorbent-based ultra-thick film traps for concentration of trace volatile components from gaseous matrices is described. The procedure is based on blowing a prepolymer (polydimethylsiloxane) through a capillary tube, forming an irregular film of stationary phase. Subsequently, the prepolymer is immobilized in a few seconds by heating to 200 degrees C. Evaluation of the performance of the new traps showed that the loss of efficiency, compared to regular smooth film traps is only on the order of 20-30%. In terms of breakthrough volume, this loss in performance is rather insignificant. The technology is extremely simple and allows a rapid and cheap production of a large number of ultra-thick film traps, even in non-specialized laboratories. The method can be applied to any type of cross-linkable stationary phase, thereby expanding the scope of sorbent-based trapping and preconcentration concept. Many applications are anticipated in trace and ultra-trace analysis in a wide range of fields, such as environmental chemistry, polymers, food and process analysis.

  4. Bubble-Induced Star Formation in Dwarf Irregular Galaxies

    CERN Document Server

    Kawata, Daisuke; Barnes, David J; Grand, Robert J J; Rahimi, Awat

    2013-01-01

    To study the star formation and feedback mechanism, we simulate the evolution of an isolated dwarf irregular galaxy (dIrr) in a fixed dark matter halo, similar in size to WLM. We use the new version of our original N-body/smoothed particle chemodynamics code, GCD+, which adopts improved hydrodynamics, metal diffusion between the gas particles and new modelling of star formation and stellar wind and supernovae (SNe) feedback. Comparing the simulations with and without stellar feedback effects, we demonstrate that the collisions of bubbles produced by strong feedback can induce star formation in a more widely spread area. We also demonstrate that the metallicity in star forming regions is kept low due to the mixing of the metal-rich bubbles and the metal-poor inter-stellar medium. Our simulations also suggest that the bubble-induced star formation leads to many counter-rotating stars. The bubble-induced star formation could be a dominant mechanism to maintain star formation in dIrrs, which is different from lar...

  5. Three-dimensional CLEM-LES of irregular detonation propagation

    Science.gov (United States)

    Maxwell, Brian; Radulescu, Matei

    2016-11-01

    Recently, thin-channel experiments and 2D simulations have been conducted in order to investigate the effect of turbulent mixing rates on the structure of irregular detonation wave propagation. Furthermore, the dependence of the observed cell pattern, and also the reaction zone thickness, on the mixing of burned products with pockets of unburned gases, was investigated. The current work now includes 3D simulations, which are conducted to provide further validation of, and insight into, the 2D results. All simulations have been conducted using the Compressible Linear Eddy Model for Large Eddy Simulation (CLEM-LES). To date, the 3D results are found to match closely the previous 2D results. The agrreement is partly due to sufficient resolution of the large scale fluid motions, which are observed experimentally to be predominant in only two directions. Furthermore, the CLEM-LES methodology incorporates 3D mixing effects at the subgrid level. Finally, it was found that turbulent fluctuations on the subgrid were found to give rise to statistically lower than average propagation velocities on the wave front. This lead to longer ignition delays for large amounts of gas passing through the wave, giving rise to the unburned pockets of gas observed experimentally. Authors would like to acknowledge NSERC and Shell for project funding.

  6. Observational study of daytime ionospheric irregularities associated with typhoon

    Institute of Scientific and Technical Information of China (English)

    XIAO SaiGuan; SHI JianKui; ZHANG DongHe; HAO YongQiang; HUANG WeiQuan

    2012-01-01

    Spread-F is a manifestation of ionospheric irregularities and generally takes place at nighttime.However,it can also be observed seldom at daytime.It is recognized that acoustic gravity waves (AGWs) play an important role in triggering plasma instability which results in spread-F in the ionosphere.The typhoon is a main source of the AGWs.In this paper,two cases of ionospheric daytime spread-F in the period of typhoon were analyzed.One case was on July 29,1988 and the other was on August 01,1989.The results showed the following:1) There were some wave-like disturbances appearing in the HF Doppler records firstly,consequently the Doppler echo traces became scattered,which indicated that the ionospheric spread-F was triggered; 2) the blurred echo traces in the both two cases appeared in the morning (08:30-11:30 Beijing time) and lasted for more than two hours; 3) with the blurred echoes gradually weakening,the traveling ionospheric disturbances (TIDs) still existed and became clearer; 4) the frequency shifts in the two cases were both positive,implying the effective reflecting surface of the radio wave in the ionosphere moved downwards.These results provide good observational evidence for daytime spread-F during the typhoon period in Asian region.

  7. Traditional and Model Based Assay of Irregular Geometry Items

    Energy Technology Data Exchange (ETDEWEB)

    MOORE, FRANK S.; SALAYMEH, SALEEM

    2005-06-15

    The Analytical Development Section (ADS) of SRNL was requested to perform a waste disposal assay of two heater boxes which had been used in the HB Line dissolvers. They had been sent to SRNL for study to make recommendations on how to prevent future failure of the units when they were replaced. The study having been completed, the units needed to be characterized prior to sending to Solid Waste for disposal. An assay station consisting of a turntable, HPGe detector, CANBERRA Inspector, transmission source and a portable computer was set up to do the required assays. The assays indicate the presence of U-235, Pu-239 and Cs-137. No measurable amounts of U-235 or Pu-239 were found. Therefore the Minimum Detectable Activities for U-235 and Pu-239 were calculated. For Heater Box 1, 0.23 grams of U-235 and 0.24 grams of Pu-239. For Heater Box 2, the results were 0.21 grams of U-235 and 0.21 grams of Pu-239. This paper describes and documents the assays employed to determine the amount of U, Pu and Cs contents of the heater boxes. The paper provides results of SNM assays using traditional calibration of the system and on one based on modeling. It also provides the scientific community with data that will assist the user in determining the method of choice for assaying items with irregular geometries.

  8. THE INCLINATION OF THE DWARF IRREGULAR GALAXY HOLMBERG II

    Directory of Open Access Journals (Sweden)

    F. J. Sánchez-Salcedo

    2014-01-01

    Full Text Available Damos restricciones al ́angulo de inclinaci ́on del disco de H i de la galaxia irregular enana Holmberg II (Ho II a partir de un an ́alisis de la estabilidad gravita cional del disco de gas en las partes externas. Encontramos que se requiere un ́angulo de inclinaci ́on medio de 27 ◦ y, por lo tanto, una velocidad circular en su parte plana de ≈ 60 km s − 1 , para tener un grado de estabilidad similar al que tienen otras galaxias. Para esa inclinaci ́on, Ho II cae en la posici ́on correcta en la relaci ́on de Tully-Fisher bar i ́onica y, adem ́as, su curva de rotaci ́on es congruente con MOND. Sin embargo, el an ́alisi s de estabilidad correspondiente indica que esta galaxia podr ́ıa ser problem ́atica para MOND porque las partes externas de esta galaxia ser ́ıan marginalmente inest ables bajo esa teor ́ıa de gravedad. Se requieren simulaciones num ́ericas de las galaxias enanas ricas en gas para ver la factibilidad de MOND.

  9. On the Borders: The Arrival of Irregular Immigrants in Malta--Some Implications for Education

    Science.gov (United States)

    Mercieca, Duncan

    2007-01-01

    This paper concerns the issue of the continual arrival of irregular immigrants in Malta and the problems that ensue. The view generally held is that we need to respond to the needs of irregular immigrants by providing services. However, with reference to some of Jacques Derrida's ideas, I argue in this paper that the "other"/immigrant is not there…

  10. On the Distinction between Regular and Irregular Inflectional Morphology: Evidence from Dinka

    Science.gov (United States)

    Ladd, D. Robert; Remijsen, Bert; Manyang, Caguor Adong

    2009-01-01

    Discussions of the psycholinguistic significance of regularity in inflectional morphology generally deal with languages in which regular forms can be clearly identified and revolve around whether there are distinct processing mechanisms for regular and irregular forms. We present a detailed description of Dinka's notoriously irregular noun number…

  11. Breaking Down Anonymity: Digital surveillance on irregular migrants in Germany and the Netherlands

    NARCIS (Netherlands)

    D.W.J. Broeders (Dennis)

    2009-01-01

    textabstractThe presence of irregular migrants causes a tough problem for policy makers. Political and popular aversion against the presence of irregular migrants has mounted in most West-European societies for years, yet their presence remains. Their exact numbers are obviously unknown - only

  12. Crime among irregular immigrants and the influence of internal border control

    NARCIS (Netherlands)

    A.S. Leerkes (Arjen); G.B.M. Engbersen (Godfried); J.P. van der Leun (Joanne)

    2012-01-01

    textabstractBoth the number of crime suspects without legal status and the number of irregular or undocumented immigrants held in detention facilities increased substantially in theNetherlands between 1997 and 2003. In this period, theDutch state increasingly attempted to exclude irregular

  13. Crime among irregular immigrants and the influence of internal border control

    NARCIS (Netherlands)

    Leerkes, A.S.; Engbersen, G.; Leun, van der J.P.

    2012-01-01

    Abstract Both the number of crime suspects without legal status and the number of irregular or undocumented immigrants held in detention facilities increased substantially in theNetherlands between 1997 and 2003. In this period, theDutch state increasingly attempted to exclude irregular immigrants

  14. Design and Analysis of Printed Reflectarrays with Irregularly Positioned Array Elements

    DEFF Research Database (Denmark)

    Zhou, Min; Sørensen, Stig; Meincke, Peter

    2012-01-01

    and an irregular layout, generating the same contoured beam pattern to cover an European region with cross-polar and sidelobe suppression have been designed. Simulations show that better performance in the cross-polar radiation can be obtained by using the irregular reflectarray, thus demonstrating the potential...

  15. The Analysis of Frequency Reuse Irregular Patterns in Mobile Telephone Network

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Some frequency reuse irregular patterns in radionetwork design are proposed,the characteristic and applica-tion measures of these patterns are analyzed.Then this paperaccounts that frequency reuse irregular patterns is a usefulway to impove spectrum efficiency and it is significative forartificial intelligence to be applied in this field.

  16. Breaking Down Anonymity: Digital surveillance on irregular migrants in Germany and the Netherlands

    NARCIS (Netherlands)

    D.W.J. Broeders (Dennis)

    2009-01-01

    textabstractThe presence of irregular migrants causes a tough problem for policy makers. Political and popular aversion against the presence of irregular migrants has mounted in most West-European societies for years, yet their presence remains. Their exact numbers are obviously unknown - only estim

  17. Are irregular hypoechoic breast masses on ultrasound always malignancies?: A Pictorial essay

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Youe Ree; Kim, Hun Soo; Kim, Hye Won [Wonkwang University Hospital, Iksan (Korea, Republic of)

    2015-12-15

    Irregular hypoechoic masses in the breast do not always indicate malignancies. Many benign breast diseases present with irregular hypoechoic masses that can mimic carcinoma on ultrasonography. Some of these diseases such as inflammation and trauma-related breast lesions could be suspected from a patient's symptoms and personal history. Careful ultrasonographic examination and biopsy could help to differentiate these from malignancies.

  18. Chemical release experiments to induce F region ionospheric plasma irregularities at the magnetic equator

    Science.gov (United States)

    Sultan, Peter Jared

    1994-01-01

    The largest-scale plasma instability that occurs naturally in the Earth's ionosphere is a turbulent upwelling of the equatorial F region known as equatorial spread-F (ESF). During an ESF event, high plasma density magnetic fluxtubes at the bottomside of the F region are thought to change places with lower plasma density flux-tubes from below in a Rayleigh-Taylor type (heavy fluid over light fluid) instability. This interchange creates a large-scale (10's of km) density perturbation locally, which rapidly penetrates through to the topside of the F region, creating a plume of cascading smaller-scale (meter to centimeter scale) irregularities from the sharp density gradients at the edges of the rising plasma 'bubble'. In a theoretical test of this overall scenario for ESF, a linear instability growth rate is derived following the magnetic fluxtube formalism of Haerendel. Using realistic atmospheric and ionospheric density model inputs, growth rates are calculated for a range of geophysical conditions. Time/altitude domains having positive growth rates are found to coincide with observed time/altitude patterns of ESF occurrence, thus supporting the fluxtube model. The physics also are tested experimentally by the deliberate creation of plasma bubbles in ambient ionospheres that the fluxtube model predicts are susceptible to the Rayleigh-Taylor instability. Two such artificial seed perturbations were generated during the 1990 NASA/Boston University CRRES-at-Kwajalein campaign, when clouds of sulfur hexafluoride (SF6) were released by sounding rockets to initiate plasma recombinations near the bottomside of the equatorial ionosphere. Multiple diagnostics (incoherent scatter radar, high frequency radar, optics, and satellite polarimeters at several sites) were used to monitor the prelaunch status of the ionosphere and the electron depleted regions that resulted from the chemical releases. Small ESF plumes were observed to form in the region of the artificial perturbation

  19. Paraphilic diagnoses in DSM-5.

    Science.gov (United States)

    Krueger, Richard B; Kaplan, Meg S

    2012-01-01

    The DSM-5 has been under revision since 1999 and is scheduled for publication in 2013. This article will review the major proposed modifications of the Paraphilias. The information reviewed was obtained from PubMed, PsychInfo, the DSM-5.org website and other sources and reviewed. Pedohebephilia, Hypersexual Disorder and Paraphilic Coercive Disorder are new proposed diagnoses. Paraphilias have been assigned their own chapter in DSM- 5 and a distinction has been made between Paraphilias and Paraphilic Disorders. Victim numbers have been included in diagnosis of paraphilias that involve victims and remission and severity measures have been added to all paraphilias. Transvestic Disorder can apply to males or females, Fetishistic Disorder now includes partialism, and Sexual Masochism Disorder has Asphyxiophilia as a specifier. This study is based on a literature review and influenced by the knowledge and biases of the authors. The Paraphilic Disorders Section of the DSM-5 represents a significant departure from DSMIV-TR.

  20. Shear Wave Propagation in Multilayered Medium including an Irregular Fluid Saturated Porous Stratum with Rigid Boundary

    Directory of Open Access Journals (Sweden)

    Ravinder Kumar

    2014-01-01

    Full Text Available The present investigation is concerned with the study of propagation of shear waves in an anisotropic fluid saturated porous layer over a semi-infinite homogeneous elastic half-space lying under an elastic homogeneous layer with irregularity present at the interface with rigid boundary. The rectangular irregularity has been taken in the half-space. The dispersion equation for shear waves is derived by using the perturbation technique followed by Fourier transformation. Numerically, the effect of irregularity present is analysed. It is seen that the phase velocity is significantly influenced by the wave number and the depth of the irregularity. The variations of dimensionless phase velocity against dimensionless wave number are shown graphically for the different size of rectangular irregularities with the help of MATLAB.

  1. THE EQUIVALENT SLOPE - A NEW METHOD FOR CALCULATING SOIL LOSS FROM IRREGULAR SLOPES

    Institute of Scientific and Technical Information of China (English)

    Xiaoguang ZHAO; Hui SHI; Ming'an SHAO

    2004-01-01

    The slopes in field conditions are always irregular, but the supposed uniform slopes are used in most erosion models. Some studies used several uniform slopes to approximate an irregular slope for estimating soil erosion. This approximation is both time-consuming and weak in physical insights. In this paper, the concept of equivalent slope is presented based on that runoff potential on uniform slope is equal to that of irregular slope, and the equivalent uniform slope is used to estimate soil erosion instead of the irregular slopes. The estimated results of slope-length factors for convex and concave slopes are consistent with those from the method of Foster and Wischmeier.The experiments in the southern part of the Loess Plateau in China confirmed the applicability of the present method. The method is simple and has, to some extent, clear physical meanings, and is applicable for estimating soil erosion from irregular slopes.

  2. Radar observations of artificial E-region field-aligned irregularities

    Directory of Open Access Journals (Sweden)

    E. Nossa

    2009-07-01

    Full Text Available Artificial E region field aligned plasma density irregularities (FAIs were generated using HAARP in four different experimental modes and observed with a coherent scatter radar imager located 450 km to the southwest where it could detect field-aligned backscatter. The experiments were conducted in July of 2008, during the Polar Aeronomy and Radio Science Summer School (PARS, during quiet conditions in the daytime when the E layer was dense and absorption was modest. The echoes observed during zenith and magnetic zenith heating experiments were deflected from their nominally anticipated horizontal positions toward the midpoint position. The occurrence of hysteresis when heating with amplitude modulated pulses implied the development of the resonance instability, although the threshold for the onset of instability appeared to be higher than what has been predicted theoretically. Heating experiments involving pump frequencies slightly above and below the second electron gyroharmonic frequency produced no significant differences in the observed echoes. Finally, heating with a pump frequency slightly above the E region critical frequency appears to have produced FAIs at two distinct altitudes where the upper-hybrid resonance condition could be satisfied.

  3. Spatial Correlation Between Dust and H$\\alpha$ Emission in Dwarf Irregular Galaxies

    CERN Document Server

    Jimmy,; Saintonge, Amélie; Accurso, Gioacchino; Brough, Sarah; Oliva-Altamirano, Paola; Salmon, Brett; Forrest, Ben

    2016-01-01

    Using a sample of dwarf irregular galaxies selected from the ALFALFA blind HI-survey and observed using the VIMOS IFU, we investigate the relationship between H$\\alpha$ emission and Balmer optical depth ($\\tau_{\\text{b}}$). We find a positive correlation between H$\\alpha$ luminosity surface density and Balmer optical depth in 8 of 11 at $\\geq$ 0.8$\\sigma$ significance (6 of 11 at $\\geq$ 1.0$\\sigma$) galaxies. Our spaxels have physical scales ranging from 30 to 80 pc, demonstrating that the correlation between these two variables continues to hold down to spatial scales as low as 30 pc. Using the Spearman's rank correlation coefficient to test for correlation between $\\Sigma_{\\text{H}\\alpha}$ and $\\tau_{\\text{b}}$ in all the galaxies combined, we find $\\rho = 0.39$, indicating a positive correlation at 4$\\sigma$ significance. Our low stellar-mass galaxy results are in agreement with observations of emission line regions in larger spiral galaxies, indicating that this relationship is independent of the size of ...

  4. Interstellar Medium Oxygen Abundances of Dwarf Irregular Galaxies in Centaurus A and Nearby Groups

    CERN Document Server

    Lee, Henry; Grebel, E K; 10.1111/j.1365-2966.2007.11481.x

    2008-01-01

    We present results of optical spectroscopy of 35 H II regions from eight dwarf galaxies in the Centaurus A group. [O III]4363 A is detected in ESO272-G025 and ESO324-G024, and direct oxygen abundances of 12+log(O/H) = 7.76 +/- 0.09 and 7.94 +/- 0.11 are derived, respectively. For the remaining galaxies, abundances are derived using common bright-line methods. To compare the influence of group environments on dwarf galaxies, we have also gathered data for additional dwarf irregular galaxies from the Cen A and the Sculptor groups from the literature. We have examined possible relationships between oxygen abundance, gas fraction, effective chemical yield, and tidal indices. Despite large positive tidal indices for a number of Cen A dwarfs in the present sample, there is no clear separation between galaxies with positive tidal indices and galaxies with negative tidal indices in the luminosity-metallicity, metallicity-gas fraction, and metallicity-tidal index diagrams. The H I surface mass density decreases with i...

  5. The health of irregular and illegal immigrants: analysis of day-hospital admissions in a department of migration medicine.

    Science.gov (United States)

    Affronti, Mario; Affronti, Andrea; Pagano, Salvatore; Soresi, Maurizio; Giannitrapani, Lydia; Valenti, Miriam; La Spada, Emanuele; Montalto, Giuseppe

    2013-10-01

    It is difficult to trace full details of the path which irregular or illegal immigrants follow when seeking assistance in the network of the various hospital departments and health structures. The aim of this work was to analyze the health needs of immigrant people by reviewing the types of treatment given to them in the day-hospital of our Department of Migration Medicine. Our study analyzed day-hospital admissions between 2003 and 2009. The patient charts used for managing day-hospital activity were adopted in 2002 in conformity with the "OSI project". From these it is possible to draw up a scale picture of the distribution of each pathology in the immigrant population. The sample population consisted of 1,758 subjects, representing 7.4% of potential users. More than half came from Africa, followed by Asia, and then Europe. Gastroenterological diseases ranked first, with dyspeptic syndromes most frequently diagnosed. Infections and parasitic diseases ranked second, and the most frequent diagnoses were sexually transmitted diseases. Third were diseases of the genitourinary system. Metabolic disorders ranked fourth, among them, more than half of the cases were of diabetes mellitus, in patients from south-east Asia. Diseases of the circulatory system were sixth, with hypertension the most frequent pathology. Our data confirm a marked persistence of the phenomenon known as the "healthy immigrant effect" in these types of patients, as well as the prominent role played by "social determinants" in conditioning the health of immigrants, particularly in the case of some infectious diseases.

  6. Dynamic stability of passive dynamic walking on an irregular surface.

    Science.gov (United States)

    Su, Jimmy Li-Shin; Dingwell, Jonathan B

    2007-12-01

    Falls that occur during walking are a significant health problem. One of the greatest impediments to solve this problem is that there is no single obviously "correct" way to quantify walking stability. While many people use variability as a proxy for stability, measures of variability do not quantify how the locomotor system responds to perturbations. The purpose of this study was to determine how changes in walking surface variability affect changes in both locomotor variability and stability. We modified an irreducibly simple model of walking to apply random perturbations that simulated walking over an irregular surface. Because the model's global basin of attraction remained fixed, increasing the amplitude of the applied perturbations directly increased the risk of falling in the model. We generated ten simulations of 300 consecutive strides of walking at each of six perturbation amplitudes ranging from zero (i.e., a smooth continuous surface) up to the maximum level the model could tolerate without falling over. Orbital stability defines how a system responds to small (i.e., "local") perturbations from one cycle to the next and was quantified by calculating the maximum Floquet multipliers for the model. Local stability defines how a system responds to similar perturbations in real time and was quantified by calculating short-term and long-term local exponential rates of divergence for the model. As perturbation amplitudes increased, no changes were seen in orbital stability (r(2)=2.43%; p=0.280) or long-term local instability (r(2)=1.0%; p=0.441). These measures essentially reflected the fact that the model never actually "fell" during any of our simulations. Conversely, the variability of the walker's kinematics increased exponentially (r(2)>or=99.6%; pwalking stability are related to each other and to risk of falling.

  7. K2 and Herschel/PACS photometry of irregular satellites

    Science.gov (United States)

    Pal, Andras; Kiss, Csaba; Molnar, Laszlo; Mueller, Thomas G.; Sarneczky, Krisztian; Szabo, Robert; Kiss, Laszlo L.; Szabo, Gyula M.

    2016-10-01

    The combination of optical and far-infrared photometric measurements yields an unambiguous method for characterizing the basic physical and surface properties of minor bodies in the Solar System. In principle, an object with a certain visible brightness can either be an object with a small but bright or a large but dim surface. To resolve this issue, conducting thermal emission measurements can also be acquired since both larger and dimmer objects have higher infrared radiations. In addition, the precise modelling of thermal emission should certainly take into account the rotation period of these bodies - otherwise the presence of surface thermal inertia can result in inaccurate conclusions regarding to the physical size and albedo.Since early 2014, Kepler Space Telescope surveys fields close to the Ecliptic in a framework of quarterly campaigns of the K2 initiative. This program makes possible to continuously observe Solar System bodies during this period of 80-90 days and hence provide an uninterrupted photometric series of moving Solar System objects down to the magnitude range of R = 23.5. This instrument hence an ideal observatory now for Solar System studies. Due to the fact that the expected rotational periods of these objects are commensurable to the diurnal characteristics of ground-based observations, such uninterrupted light curves are rather valuable for the accurate determination of rotational characteristics - including the physical rotation period, the amplitude and the confirmation of the presence of double- or multiple peaked features.In this presentation we summarize our results of current K2 and legacy Herschel/PACS observations regarding to some of the irregular satellites of Uranus and Neptune, namely Caliban, Sycorax, Prospero, Setebos and Nereid. By comparing these results with similar kind of observations for trans-Neptunian objects (see Kiss et al., this DPS meeting), one can conclude how the formation and evolution of the outer Solar

  8. THE MEASUREMENT METHODOLOGY IMPROVEMENT OF THE HORIZONTAL IRREGULARITIES IN PLAN

    Directory of Open Access Journals (Sweden)

    O. M. Patlasov

    2015-08-01

    Full Text Available Purpose. Across the track superstructure (TSS there are structures where standard approach to the decision on the future of their operation is not entirely correct or acceptable. In particular, it concerns the track sections which are sufficiently quickly change their geometric parameters: the radius of curvature, angle of rotation, and the like. As an example, such portions of TSS may include crossovers where their component is within the so-called connecting part, which at a sufficiently short length, substantially changes curvature. The estimation of the position in terms of a design on the basis of the existing technique (by the difference in the adjacent arrows bending is virtually impossible. Therefore it is proposed to complement and improve the methodology for assessing the situation of the curve in plan upon difference in the adjacent versine. Methodology. The possible options for measuring horizontal curves in the plan were analyzed. The most adequate method, which does not contradict existing on the criterion of the possibility of using established standards was determined. The ease of measurement and calculation was took into account. Findings. Qualitative and quantitative verification of the proposed and existing methods showed very good agreement of the measurement results. This gives grounds to assert that this methodology can be recommended to the workers of track facilities in the assessment of horizontal irregularities in plan not only curves, but also within the connecting part of switch congresses. Originality. The existing method of valuation of the geometric position of the curves in the plan was improved. It does not create new regulations, and all results are evaluated by existing norms. Practical value. The proposed technique makes it possible, without creating a new regulatory framework, to be attached to existing one, and expanding the boundaries of its application. This method can be used not only for ordinary curves

  9. Solar cycle dependent characteristics of the equatorial blanketing Es layers and associated irregularities

    Directory of Open Access Journals (Sweden)

    S. Ravindran

    2006-11-01

    Full Text Available The occurrence of blanketing type Es (Esb layers and associated E-region irregularities over the magnetic equatorial location of Trivandrum (8.5° N; 77° E; dip ~0.5° during the summer solstitial months of May, June, July and August has been investigated in detail for the period 1986–2000 to bring out the variabilities in their characteristics with the solar cycle changes. The study has been made using the ionosonde and magnetometer data of Trivandrum from 1986–2000 along with the available data from the 54.95 MHz VHF backscatter radar at Trivandrum for the period 1995–2000. The appearance of blanketing Es layers during these months is observed to be mostly in association with the occurrence of afternoon Counter Electrojet (CEJ events. The physical process leading to the occurrence of a CEJ event is mainly controlled by the nature of the prevailing electro dynamical/neutral dynamical conditions before the event. Hence it is natural that the Esb layer characteristics like the frequency of occurrence, onset time, intensity, nature of gradients in its top and bottom sides etc are also affected by the nature of the background electro dynamical /neutral dynamical processes which in turn are strongly controlled by the solar activity changes. The occurrence of Esb layers during the solstitial months is found to show very strong solar activity dependence with the occurrence frequency being very large during the solar minimum years and very low during solar maximum years. The intensity of the VHF radar backscattered signals from the Esb irregularities is observed to be controlled by the relative roles of the direction and magnitude of the prevailing vertical polarization electric field and the vertical electron density gradient of the prevailing Esb layer depending on the phase of the solar cycle. The gradient of the Esb layer shows a more dominant role in the generation of gradient instabilities during solar minimum periods while it is the

  10. Probability of Capture of Irregular Satellites via Collisions Around the Gas Giant Planets as a Function of the Solar Nebula

    CERN Document Server

    Koch, F Elliott

    2011-01-01

    We investigated the probability that an inelastic collision of planetesimals within the Hill sphere of the Jovian planets could explain the presence and orbits of observed irregular satel- lites. Capture of satellites via this mechanism is highly dependent on not only the mass of the protoplanetary disk, but also the shape of the planetesimal size distribution. We performed 2000 simulations for integrated time intervals ~ 2 Myr and found that, given the currently ac- cepted value for the minimum mass solar nebula and planetesimal number density based upon the Bottke et al. (2010b) size distribution dN ~ D-1.8dD, the collision rates for the different Jovian planets range between ~ 60 and >~ 103 Myr-1 Additionally, we found that the prob- ability that these collisions remove enough orbital energy to yield a bound orbit was ~ 103 times the gravitational binding energy for objects with radii ~ 100 km. We find that, capturing irregular satellites via collisions between unbound objects can only account for ~ 0.1% o...

  11. [Left pulmonary agenesis diagnosed late].

    Science.gov (United States)

    Deleanu, Oana; Pătraşcu, Natalia; Nebunoiu, Ana-Maria; Vintilă, V; Ulmeanu, Ruxandra; Mihălţan, F D

    2010-01-01

    We present the case of a 51 years old female-patient, with severe dextroscoliosis, having like unique symptom progressive dyspnea. The blood samples reveals polycythemia, the radiological exam shows the opacification of 2/3 of the left thorax, the absence of the lung structure in the other 1/3, the deviation of the mediastinum, and dextroscoliosis; the computed tomography reveals the absence of the left lung artery and the left airways, compensatory hyperinflation of the right lung and dilatation of the trunk and right pulmonary artery; the bronchoscopy does not visualize the carina or the left main bronchus, typical for pulmonary agenesis. Echocardiography confirmed the absence of left pulmonary artery and shows mild pulmonary hypertension (systolic pressure in the pulmonary artery of 33 mmHg) with dilatation of the right cavities, but good cinetics. We face a case of pulmonary agenesis lately diagnosed, with modest functional cardiologic implications, limited therapeutic options and good survival, justified by the late appearance of the pulmonary hypertension of low severity and without worsening in time.

  12. Determining dynamic parameters of different-scale ionospheric irregularities over northern Siberia

    Science.gov (United States)

    Afraimovich, E. L.; Lipko, Y. V. Y. V.; Vugmeister, B. O.

    2000-01-01

    In 1995-1996, observations were carried out at Norilsk (geomagnetic latitude and longitude 64.2 degN and 160.4 degE) to determine dynamic parameters of irregularities in the high-latitude ionosphere. The short-baseline spaced-receiver method that has been implemented at the ionospheric facility of the Norilsk Integrated Magnetic-Ionospheric Station, provides a means of simultaneously measuring parameters of small-scale irregularities (spatial scale of 3-5 km) by the Similar-Fading Method (SFM), as well as of medium-scale irregularities (time scale of 10-30 min, spatial scale of hundreds of kilometres) by the Statistical Angle-of-arrival and Doppler Method (SADM). About 20 h of the observational data for the F2-layer under quiet geomagnetic conditions (Kp = 3) and about 15 h for the sporadic E-layer (Kp ~ 3) were processed. It has been found that the propagation directions and velocities of different-scale irregularities do not coincide. Small-scale irregularities of the F2-layer travel predominantly eastward or westward. The velocity of the F2-layer irregularities is about 100 m/s, and under disturbed conditions it is up to 200-250 m/s. Small-scale irregularities of the sporadic E-layer travel mostly in the northward direction. It is confirmed that the Es-layer is characterised by high velocities of the irregularities (as high as 1000 m/s). Medium-scale irregularities with periods in the range of 10-30 min travel mostly in a southward direction with velocities of 20-40 m/s.

  13. The dynamics of rings around small, irregular bodies

    Science.gov (United States)

    Sicardy, Bruno

    2017-06-01

    Stellar occultations revealed the presence of two dense rings around the Centaur object (10199) Chariklo (Braga-Ribas et al., Nature 508, 72, 2014). This is the first ring system discovered around an object that is not a giant planet, suggesting that rings may exist around numerous bodies in the solar system. Chariklo's rings roughly reside at the outer limit of the Roche zone of the body. Moreover, the main ring has sharp edges, which call for the presence of putative shepherd satellites. Those characteristics give an image of Chariklo's rings that are rather similar, in terms of dynamics, to those surrounding the gaseous planets.An important difference exists, however, between giant planets and small bodies: the formers are highly axisymmetric, while the latters can support mass anomalies (eg surface topographic features) or non-spherical shapes (eg an ellipsoidal figure of equilibrium) that involve masses, relative to the body itself, as large as 10-4-10-3.We investigate the effect of non-axisymmetric terms in the potential of the body upon a collisional debris disk that initially surrounds a small irregular body. We show that the corotation points being maxima of energy, dissipative collisions remove the particles from the corotation zone over short time scales (< 106 years). Moreover, the Lindblad resonances inside the corotation radius create torques that drive the particles onto the surface of the central body. Conversely, the outer Lindblad resonances push the disk material beyond the outer 3/2 and 2/1 Lindblad resonances.Taking as an example Chariklo's ring system, for which recent data have been obtained from stellar occultations, we show that the Lindblad resonant torques actuate over short time scales (< 106 years). This general picture offers a natural explanation of the presence of dense rings at the outer limit of Chariklo's Roche zone, and their absence closer to the body.The work leading to this results has received funding from the European

  14. Shape reconstruction of irregular bodies with multiple complementary data sources

    Science.gov (United States)

    Kaasalainen, M.; Viikinkoski, M.; Carry, B.; Durech, J.; Lamy, P.; Jorda, L.; Marchis, F.; Hestroffer, D.

    2011-10-01

    Irregularly shaped bodies with at most partial in situ data are a particular challenge for shape reconstruction and mapping. We have created an inversion algorithm and software package for complementary data sources, with which it is possible to create shape and spin models with feature details even when only groundbased data are available. The procedure uses photometry, adaptive optics or other images, occultation timings, and interferometry as main data sources, and we are extending it to include range-Doppler radar and thermal infrared data as well. The data sources are described as generalized projections in various observable spaces [2], which allows their uniform handling with essentially the same techniques, making the addition of new data sources inexpensive in terms of computation time or software development. We present a generally applicable shape support that can be automatically used for all surface types, including strongly nonconvex or non-starlike shapes. New models of Kleopatra (from photometry, adaptive optics, and interferometry) and Hermione are examples of this approach. When using adaptive optics images, the main information from these is extracted from the limb and terminator contours that can be determined much more accurately than the image pixel brightnesses that inevitably contain large errors for most targets. We have shown that the contours yield a wealth of information independent of the scattering properties of the surface [3]. Their use also facilitates a very fast and robustly converging algorithm. An important concept in the inversion is the optimal weighting of the various data modes. We have developed a mathematicallly rigorous scheme for this purpose. The resulting maximum compatibility estimate [3], a multimodal generalization of the maximum likelihood estimate, ensures that the actual information content of each source is properly taken into account, and that the resolution scale of the ensuing model can be reliably estimated

  15. Target Tracking of a Linear Time Invariant System under Irregular Sampling

    Directory of Open Access Journals (Sweden)

    Jin Xue-Bo

    2012-11-01

    Full Text Available Due to event-triggered sampling in a system, or maybe with the aim of reducing data storage, tracking many applications will encounter irregular sampling time. By calculating the matrix exponential using an inverse Laplace transform, this paper transforms the irregular sampling tracking problem to the problem of tracking with time-varying parameters of a system. Using the common Kalman filter, the developed method is used to track a target for the simulated trajectory and video tracking. The results of simulation experiments have shown that it can obtain good estimation performance even at a very high irregular rate of measurement sampling time.

  16. The effects of magnetic storm phases on F-layer irregularities from auroral to equatorial latitudes

    Science.gov (United States)

    Aarons, Jules; Mendillo, Michael

    1990-12-01

    Some topics of discussion in this journal include the following: The effects of electric field and ring current energy increases on F-layer irregularities at auroral and sub-auroral latitudes; The role of the ring current in generating or inhibiting equatorial F-layer irregularities during magnetic storms; Auroral and sub-auroral F-layer irregularities and high plasma convection during the magnetically active periods of September 17-24, 1984; and Simultaneous All-Sky Optical Airglow Imaging Observations and San Marco Satellite Measurements in the Pacific Sector.

  17. Novel approaches in diagnosing tuberculosis

    Science.gov (United States)

    Kolk, Arend H. J.; Dang, Ngoc A.; Kuijper, Sjoukje; Gibson, Tim; Anthony, Richard; Claassens, Mareli M.; Kaal, Erwin; Janssen, Hans-Gerd

    2011-06-01

    The WHO declared tuberculosis (TB) a global emergency. An estimated 8-9 million new cases occur each year with 2-3 million deaths. Currently, TB is diagnosed mostly by chest-X ray and staining of the mycobacteria in sputum with a detection limit of 1x104 bacteria /ml. There is an urgent need for better diagnostic tools for TB especially for developing countries. We have validated the electronic nose from TD Technology for the detection of Mycobacterium tuberculosis by headspace analysis of 284 sputum samples from TB patients. We used linear discriminant function analysis resulting in a sensitivity of 75% a specificity of 67% and an accuracy of 69%. Further research is still required to improve the results by choosing more selective sensors and sampling techniques. We used a fast gas chromatography- mass spectrometry method (GC-MS). The automated procedure is based on the injection of sputum samples which are methylated inside the GC injector using thermally assisted hydrolysis and methylation (THM-GC-MS). Hexacosanoic acid in combination with tuberculostearic acid was found to be specific for the presence of M. tuberculosis. The detection limit was similar to microscopy. We found no false positives, all microscopy and culture positive samples were also found positive with the THM-GC-MS method. The detection of ribosomal RNA from the infecting organism offers great potential since rRNA molecules outnumber chromosomal DNA by a factor 1000. It thus may possible to detect the organism without amplification of the nucleic acids (NA). We used a capture and a tagged detector probe for the direct detection of M. tuberculosis in sputum. So far the detection limit is 1x106 bacteria / ml. Currently we are testing a Lab-On-A-Chip Interferometer detection system.

  18. Are Pediatricians Diagnosing Obese Children?

    Science.gov (United States)

    Thomas, Katharine; Urrego, Fernando

    2017-01-01

    Background: Pediatric obesity is the most prevalent nutritional disorder in American children. The detrimental social, psychological, and physiological effects of obesity call for pediatricians to address this health concern. The literature demonstrates that clinicians are underreporting the diagnosis of obesity in the pediatric setting. The primary purpose of this study was to determine if pediatricians at one pediatrics clinic in the Ochsner Health System are documenting the presence of an overweight or obese body mass index (BMI) as a diagnosis in the medical record. A secondary purpose of this study was to determine the demographics of all pediatric patients in the Ochsner Health System to be used for program development. Methods: A retrospective medical record review was conducted. Records from April 1, 2012 to April 1, 2016, were reviewed for the presence of the diagnosis of BMI classified as obese or overweight. Results: We analyzed a total of 175,066 records in this study. Of these records, 1.32% documented a diagnosis of obesity, and 0.5% documented a BMI score indicating overweight. The percentages of patient visits that met the Centers for Disease Control and Prevention criteria to be classified as obese or overweight were 28.66% and 30.41%, respectively. The majority of our pediatric patients were male (51.76%), white (43.31%), and 5-12 years old (43.80%). Conclusion: This study demonstrates that pediatricians at Ochsner Health Center for Children are not diagnosing patients who have unhealthy BMI scores as overweight or obese. Interventions are needed to increase the identification of children who may benefit from receiving resources that encourage a healthy lifestyle and optimal weight maintenance. PMID:28331453

  19. Monolingual and Bilingual Recognition of Regular and Irregular English Verbs: Sensitivity to Form Similarity Varies with First Language Experience

    Science.gov (United States)

    Basnight-Brown, Dana M.; Chen, Lang; Hua, Shu; Kostic, Aleksandar; Feldman, Laurie Beth

    2007-01-01

    We used a cross-modal priming procedure to explore the processing of irregular and regular English verb forms in both monolinguals and bilinguals (Serbian-English, Chinese-English). Materials included irregular nested stem (drawn-DRAW), irregular change stem (ran-RUN), and regular past tense-present tense verb pairs that were either low…

  20. The spatially resolved Kennicutt-Schmidt relation in the H I-dominated regions of spiral and dwarf irregular galaxies

    Science.gov (United States)

    Roychowdhury, Sambit; Huang, Mei-Ling; Kauffmann, Guinevere; Wang, Jing; Chengalur, Jayaram N.

    2015-06-01

    We study the Kennicutt-Schmidt relation between average star formation rate (SFR) and average cold gas surface density in the H I-dominated ISM of nearby spiral and dwarf irregular galaxies. We divide galaxies into grid cells varying from sub-kpc to tens of kpc in size. Grid-cell measurements of low SFRs using Hα emission can be biased and scatter may be introduced because of non-uniform sampling of the IMF or because of stochastically varying star formation. In order to alleviate these issues, we use far-ultraviolet emission to trace SFR, and we sum up the fluxes from different bins with the same gas surface density to calculate the average ΣSFR at a given value of Σgas. We study the resulting Kennicutt-Schmidt relation in 400 pc, 1 kpc and 10 kpc scale grids in nearby massive spirals and in 400 pc scale grids in nearby faint dwarf irregulars. We find a relation with a power-law slope of 1.5 in the H I-dominated regions for both kinds of galaxies. The relation is offset towards longer gas consumption time-scales compared to the molecular-hydrogen-dominated centres of spirals, but the offset is an order of magnitude less than that quoted by earlier studies. Our results lead to the surprising conclusion that conversion of gas to stars is independent of metallicity in the H I-dominated regions of star-forming galaxies. Our observed relations are better fit by a model of star formation based on thermal and hydrostatic equilibrium in the ISM, in which stellar heating and supernova feedback set the thermal and turbulent pressure.

  1. Regular and Irregular Boundary Conditions in the AdS/CFT Correspondence

    CERN Document Server

    Mück, W

    1999-01-01

    We expand on Klebanov and Witten's recent proposal for formulating the AdS/CFT correspondence using irregular boundary conditions. The proposal is shown to be correct to any order in perturbation theory.

  2. On Impulsive Boundary Value Problems of Fractional Differential Equations with Irregular Boundary Conditions

    Directory of Open Access Journals (Sweden)

    Guotao Wang

    2012-01-01

    Full Text Available We study nonlinear impulsive differential equations of fractional order with irregular boundary conditions. Some existence and uniqueness results are obtained by applying standard fixed-point theorems. For illustration of the results, some examples are discussed.

  3. Unified theory of type I and type II irregularities in the equatorial electrojet

    Science.gov (United States)

    Sudan, R. N.

    1983-01-01

    A nonlinear unified theory of type I and II irregularities is presented that explains their principal observed characteristics. The power spectrum is predicted by using Kolmogoroff-type conservation law for the power flow in cascading eddies.

  4. The encoding of temporally irregular and regular visual patterns in the human brain.

    Directory of Open Access Journals (Sweden)

    Semir Zeki

    Full Text Available In the work reported here, we set out to study the neural systems that detect predictable temporal patterns and departures from them. We used functional magnetic resonance imaging (fMRI to locate activity in the brains of subjects when they viewed temporally regular and irregular patterns produced by letters, numbers, colors and luminance. Activity induced by irregular sequences was located within dorsolateral prefrontal cortex, including an area that was responsive to irregular patterns regardless of the type of visual stimuli producing them. Conversely, temporally regular arrangements resulted in activity in the right frontal lobe (medial frontal gyrus, in the left orbito-frontal cortex and in the left pallidum. The results show that there is an abstractive system in the brain for detecting temporal irregularity, regardless of the source producing it.

  5. Periodic Orbit Families in the Gravitational Field of Irregular-shaped Bodies

    CERN Document Server

    Jiang, Yu

    2016-01-01

    The discovery of binary and triple asteroids in addition to the execution of space missions to minor celestial bodies in the past several years have focused increasing attention on periodic orbits around irregular-shaped celestial bodies. In the present work, we adopt a polyhedron shape model for providing an accurate representation of irregular-shaped bodies, and employ the model to calculate their corresponding gravitational and effective potentials. We also investigate the characteristics of periodic orbit families and the continuation of periodic orbits. We prove a fact, which provides a conserved quantity that permits restricting the number of periodic orbits in a fixed energy curved surface about an irregular-shaped body. The collisions of Floquet multipliers are maintained during the continuation of periodic orbits around the comet 1P/Halley. Multiple bifurcations in the periodic orbit families about irregular-shaped bodies are also discussed. Three bifurcations in the periodic orbit family have been f...

  6. EVALUATION OF SEISMIC BEHAVIOR OF IRREGULAR TUBE BUILDINGS IN TUBE SYSTEMS

    Directory of Open Access Journals (Sweden)

    Hojat Allah Ghasemi

    2016-03-01

    Full Text Available Setbacks in the volume of a building usually arise from the demands of urban design for illumination, proportion, etc. However, in seismic events they are the cause of abrupt changes in stiffness and mass producing a concentration of stresses in the floors near the site of sudden change. In general terms, one should ensure that the transitions are as gradual as possible in order to avoid such concentration of stresses. This study is intended to investigate seismic behavior of irregular building tube in tube systems, for this purpose seismic behavior of 40-story and 60-story reinforced concrete frame building with irregular plan was evaluated, seismic behavior of irregular buildings was assessed by overall building drifts, story drifts and shear lag behavior factors.. Higher irregularities in the overall plan structure of a building increase the phenomena of story drift and shear lag phenomena. Story drift and shear lag are higher for 60-story building than for a 40-story building.

  7. Irregular singularities in Liouville theory and Argyres-Douglas type gauge theories, I

    Energy Technology Data Exchange (ETDEWEB)

    Gaiotto, D. [Institute for Advanced Study (IAS), Princeton, NJ (United States); Teschner, J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2012-03-15

    Motivated by problems arising in the study of N=2 supersymmetric gauge theories we introduce and study irregular singularities in two-dimensional conformal field theory, here Liouville theory. Irregular singularities are associated to representations of the Virasoro algebra in which a subset of the annihilation part of the algebra act diagonally. In this paper we define natural bases for the space of conformal blocks in the presence of irregular singularities, describe how to calculate their series expansions, and how such conformal blocks can be constructed by some delicate limiting procedure from ordinary conformal blocks. This leads us to a proposal for the structure functions appearing in the decomposition of physical correlation functions with irregular singularities into conformal blocks. Taken together, we get a precise prediction for the partition functions of some Argyres-Douglas type theories on S{sup 4}. (orig.)

  8. Irregular Wave Forces on Monopile Foundations. Effect af Full Nonlinearity and Bed Slope

    DEFF Research Database (Denmark)

    Schløer, Signe; Bredmose, Henrik; Bingham, Harry B.

    2011-01-01

    Forces on a monopile from a nonlinear irregular unidirectional wave model are investigated. Two seabed profiles of different slopes are considered. Morison’s equation is used to investigate the forcing from fully nonlinear irregular waves and to compare the results with those obtained from linear...... wave theory and with stream function wave theory. The latter of these theories is only valid on a flat bed. The three predictions of wave forces are compared and the influence of the bed slope is investigated. Force-profiles of two selected waves from the irregular wave train are further compared...... with the corresponding forceprofiles from stream function theory. The results suggest that the nonlinear irregular waves give rise to larger extreme wave forces than those predicted by linear theory and that a steeper bed slope increases the wave forces both for linear and nonlinear waves. It is further found...

  9. Association between sleep duration and menstrual cycle irregularity in Korean female adolescents.

    Science.gov (United States)

    Nam, Ga Eun; Han, Kyungdo; Lee, Gyungjoo

    2017-07-01

    The association between sleep and the menstrual cycle in the adolescent population has been scarcely studied. This study aimed to investigate the association between sleep duration and menstrual cycle irregularity among female adolescents using nationwide representative data from the South Korean population. This population-based, cross-sectional study used the data collected from Korea National Health and Nutrition Examination Survey 2010-2012, and the data from 801 female adolescents were analyzed. Hierarchical multivariable logistic regression analysis was performed to assess the risk of menstrual cycle irregularity in relation to sleep duration. Subjects with menstrual cycle irregularity accounted for 15% (N = 120). The mean sleep duration in subjects with menstrual cycle irregularity was significantly shorter than that in those without (p = 0.003). Menstrual cycle irregularity prevalence tended to decrease as sleep duration increased (p for trend = 0.004), which was significantly different based on sleep duration and presence of depressive mood (p = 0.011). Sleep duration ≤5 h per day was significantly associated with increased risk of menstrual cycle irregularity compared with that in the subjects whose sleep duration is ≥8 h per day even after adjusting for confounding variables. The odds ratios of menstrual cycle irregularity tended to increase for shorter sleep duration in all adjusted models. This study found a significant inverse association between sleep duration and menstrual cycle irregularity among Korean female adolescents. Increasing sleep duration is required to improve the reproductive health of female adolescents. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Climatological study of ionospheric irregularities over the European mid-latitude sector with GPS

    Science.gov (United States)

    Wautelet, Gilles; Warnant, René

    2014-03-01

    High-frequency variability of the ionosphere, or irregularities, constitutes the main threat for real-time precise positioning techniques based on Global Navigation Satellite Systems (GNSS) measurements. Indeed, during periods of enhanced ionospheric variability, GNSS users in the field—who cannot verify the integrity of their measurements—will experience positioning errors that can reach several decimeters, while the nominal accuracy of the technique is cm-level. In the frame of this paper, a climatological analysis of irregularities over the European mid-latitude region is presented. Based on a 10 years GPS dataset over Belgium, the work analyzes the occurrence rate (as a function of the solar cycle, season and local time) as well as the amplitude of ionospheric irregularities observed at a single GPS station. The study covers irregularities either due to space weather events (solar origin) or of terrestrial origin. If space weather irregularities are responsible for the largest effects in terms of ionospheric error, their occurrence rate highly depends on solar activity. Indeed, the occurrence rate of ionospheric irregularities is about 9 % during solar maximum, whereas it drops to about 0 % during medium or low solar activity periods. Medium-scale ionospheric disturbances (MSTIDs) occurring during daytime in autumn/winter are the most recurrent pattern of the time series, with yearly proportions slightly varying with the solar cycle and an amplitude of about 10 % of the TEC background. Another recurrent irregularity type, though less frequent than MSTIDs, is the noise-like variability in TEC observed during summer nighttime, under quiet geomagnetic conditions. These summer nighttime irregularities exhibit amplitudes ranging between 8 and 15 % of the TEC background.

  11. Experimental Investigation of Wave-Induced Hydroelastic Vibrations of Trimaran in Oblique Irregular Waves

    Directory of Open Access Journals (Sweden)

    Haoyun Tang

    2016-01-01

    Full Text Available The irregular wave condition, especially the oblique irregular wave condition, is the actual circumstances when trimaran is sailing in sea. In order to identify the characteristic of the wave-induced hydroelastic vibration in irregular waves, as well as investigate the change of vibration in different oblique irregular wave conditions, trimaran model tests were conducted to measure vibrations, wave impact, and motion under different azimuth and wave height. The vibration on main hull, side hull, and cross-desk is measured and analyzed separately to observe the influence of irregular wave in different structural parts. The longitudinal vibration, transverse vibration, and torsion are also included in the model tests measurement to investigate the relationship between these vibration deformation components and parameters of the irregular waves. The wave-induced hydroelastic vibrations and whipping effect is extracted and analyzed to find influence of whipping and springing on the total vibration. Based on the analysis, the dangerous positions and the critical waves condition is introduced to ensure that the subsequent structural strength assessment is more reliable.

  12. Effects of surface irregularities on intensity data from laser scanning: an experimental approach.

    Directory of Open Access Journals (Sweden)

    G. Teza

    2008-06-01

    Full Text Available The results of an experiment carried out with the aim to investigate the role of surface irregularities on the intensity data provided by a terrestrial laser scanner (TLS survey are reported here. Depending on surface roughness, the interaction between an electromagnetic wave and microscopic irregularities leads to a Lambertian-like diffusive light reflection, allowing the TLS to receive the backscattered component of the signal. The described experiment consists in a series of TLS-based acquisitions of a rotating artificial target specifically conceived in order to highlight the effects on the intensity data due to surface irregularity. This target is articulated in a flat plate and in an irregular surface, whose macro-roughness has a characteristic length with the same order of the spot size. Results point out the different behavior of the plates. The intensity of the signal backscattered by the planar element decreases if the incidence angle increases, whereas the intensity of the signal backscattered by the irregular surface is almost constant if the incidence angle varies. Since the typical surfaces acquired in a geological/geophysical survey are generally irregular, these results imply that the intensity data can be easily used in order to evaluate the reflectance of the material at the considered wavelength, e.g. for pattern recognition purposes.

  13. Modification of transmission dose algorithm for irregularly shaped radiation field and tissue deficit

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Hyong Geon; Shin, Kyo Chul [Dankook Univ., College of Medicine, Seoul (Korea, Republic of); Huh, Soon Nyung; Woo, Hong Gyun; Ha, Sung Whan [Seoul National Univ., College of Medicine, Seoul (Korea, Republic of); Lee, Hyoung Koo [The Catholic Univ., College of Medicine, Seoul (Korea, Republic of)

    2002-07-01

    Algorithm for estimation of transmission dose was modified for use in partially blocked radiation fields and in cases with tissue deficit. The beam data was measured with flat solid phantom in various conditions of beam block. And an algorithm for correction of transmission dose in cases of partially blocked radiation field was developed from the measured data. The algorithm was tested in some clinical settings with irregular shaped field. Also, another algorithm for correction of transmission dose for tissue deficit was developed by physical reasoning. This algorithm was tested in experimental settings with irregular contours mimicking breast cancer patients by using multiple sheets of solid phantoms. The algorithm for correction of beam block could accurately reflect the effect of beam block, with error within {+-}1.0%, both with square fields and irregularly shaped fields. The correction algorithm for tissue deficit could accurately reflect the effect of tissue deficit with errors within {+-}1.0% in most situations and within {+-}3.0% in experimental settings with irregular contours mimicking breast cancer treatment set-up. Developed algorithms could accurately estimate the transmission dose in most radiation treatment settings including irregularly shaped field and irregularly shaped body contour with tissue deficit in transmission dosimetry.

  14. Design and development of LED-based irregular leather area measuring machine

    Science.gov (United States)

    Adil, Rehan; Khan, Sarah Jamal

    2012-01-01

    Using optical sensor array, a precision motion control system in a conveyer follows the irregular shaped leather sheet to measure its surface area. In operation, irregular shaped leather sheet passes on conveyer belt and optical sensor array detects the leather sheet edge. In this way outside curvature of the leather sheet is detected and is then feed to the controller to measure its approximate area. Such system can measure irregular shapes, by neglecting rounded corners, ellipses etc. To minimize the error in calculating surface area of irregular curve to the above mentioned system, the motion control system only requires the footprint of the optical sensor to be small and the distance between the sensors is to be minimized. In the proposed technique surface area measurement of irregular shaped leather sheet is done by defining velocity and detecting position of the move. The motion controller takes the information and creates the necessary edge profile on point-to-point bases. As a result irregular shape of leather sheet is mapped and is then feed to the controller to calculate surface area.

  15. Characterizing neural activities evoked by manual acupuncture through spiking irregularity measures

    Science.gov (United States)

    Xue, Ming; Wang, Jiang; Deng, Bin; Wei, Xi-Le; Yu, Hai-Tao; Chen, Ying-Yuan

    2013-09-01

    The neural system characterizes information in external stimulations by different spiking patterns. In order to examine how neural spiking patterns are related to acupuncture manipulations, experiments are designed in such a way that different types of manual acupuncture (MA) manipulations are taken at the ‘Zusanli’ point of experimental rats, and the induced electrical signals in the spinal dorsal root ganglion are detected and recorded. The interspike interval (ISI) statistical histogram is fitted by the gamma distribution, which has two parameters: one is the time-dependent firing rate and the other is a shape parameter characterizing the spiking irregularities. The shape parameter is the measure of spiking irregularities and can be used to identify the type of MA manipulations. The coefficient of variation is mostly used to measure the spike time irregularity, but it overestimates the irregularity in the case of pronounced firing rate changes. However, experiments show that each acupuncture manipulation will lead to changes in the firing rate. So we combine four relatively rate-independent measures to study the irregularity of spike trains evoked by different types of MA manipulations. Results suggest that the MA manipulations possess unique spiking statistics and characteristics and can be distinguished according to the spiking irregularity measures. These studies have offered new insights into the coding processes and information transfer of acupuncture.

  16. New prospective 4D-CT for mitigating the effects of irregular respiratory motion

    Science.gov (United States)

    Pan, Tinsu; Martin, Rachael M.; Luo, Dershan

    2017-08-01

    Artifact caused by irregular respiration is a major source of error in 4D-CT imaging. We propose a new prospective 4D-CT to mitigate this source of error without new hardware, software or off-line data-processing on the GE CT scanner. We utilize the cine CT scan in the design of the new prospective 4D-CT. The cine CT scan at each position can be stopped by the operator when an irregular respiration occurs, and resumed when the respiration becomes regular. This process can be repeated at one or multiple scan positions. After the scan, a retrospective reconstruction is initiated on the CT console to reconstruct only the images corresponding to the regular respiratory cycles. The end result is a 4D-CT free of irregular respiration. To prove feasibility, we conducted a phantom and six patient studies. The artifacts associated with the irregular respiratory cycles could be removed from both the phantom and patient studies. A new prospective 4D-CT scanning and processing technique to mitigate the impact of irregular respiration in 4D-CT has been demonstrated. This technique can save radiation dose because the repeat scans are only at the scan positions where an irregular respiration occurs. Current practice is to repeat the scans at all positions. There is no cost to apply this technique because it is applicable on the GE CT scanner without new hardware, software or off-line data-processing.

  17. Computational phenotype discovery using unsupervised feature learning over noisy, sparse, and irregular clinical data.

    Directory of Open Access Journals (Sweden)

    Thomas A Lasko

    Full Text Available Inferring precise phenotypic patterns from population-scale clinical data is a core computational task in the development of precision, personalized medicine. The traditional approach uses supervised learning, in which an expert designates which patterns to look for (by specifying the learning task and the class labels, and where to look for them (by specifying the input variables. While appropriate for individual tasks, this approach scales poorly and misses the patterns that we don't think to look for. Unsupervised feature learning overcomes these limitations by identifying patterns (or features that collectively form a compact and expressive representation of the source data, with no need for expert input or labeled examples. Its rising popularity is driven by new deep learning methods, which have produced high-profile successes on difficult standardized problems of object recognition in images. Here we introduce its use for phenotype discovery in clinical data. This use is challenging because the largest source of clinical data - Electronic Medical Records - typically contains noisy, sparse, and irregularly timed observations, rendering them poor substrates for deep learning methods. Our approach couples dirty clinical data to deep learning architecture via longitudinal probability densities inferred using Gaussian process regression. From episodic, longitudinal sequences of serum uric acid measurements in 4368 individuals we produced continuous phenotypic features that suggest multiple population subtypes, and that accurately distinguished (0.97 AUC the uric-acid signatures of gout vs. acute leukemia despite not being optimized for the task. The unsupervised features were as accurate as gold-standard features engineered by an expert with complete knowledge of the domain, the classification task, and the class labels. Our findings demonstrate the potential for achieving computational phenotype discovery at population scale. We expect such

  18. Computational phenotype discovery using unsupervised feature learning over noisy, sparse, and irregular clinical data.

    Science.gov (United States)

    Lasko, Thomas A; Denny, Joshua C; Levy, Mia A

    2013-01-01

    Inferring precise phenotypic patterns from population-scale clinical data is a core computational task in the development of precision, personalized medicine. The traditional approach uses supervised learning, in which an expert designates which patterns to look for (by specifying the learning task and the class labels), and where to look for them (by specifying the input variables). While appropriate for individual tasks, this approach scales poorly and misses the patterns that we don't think to look for. Unsupervised feature learning overcomes these limitations by identifying patterns (or features) that collectively form a compact and expressive representation of the source data, with no need for expert input or labeled examples. Its rising popularity is driven by new deep learning methods, which have produced high-profile successes on difficult standardized problems of object recognition in images. Here we introduce its use for phenotype discovery in clinical data. This use is challenging because the largest source of clinical data - Electronic Medical Records - typically contains noisy, sparse, and irregularly timed observations, rendering them poor substrates for deep learning methods. Our approach couples dirty clinical data to deep learning architecture via longitudinal probability densities inferred using Gaussian process regression. From episodic, longitudinal sequences of serum uric acid measurements in 4368 individuals we produced continuous phenotypic features that suggest multiple population subtypes, and that accurately distinguished (0.97 AUC) the uric-acid signatures of gout vs. acute leukemia despite not being optimized for the task. The unsupervised features were as accurate as gold-standard features engineered by an expert with complete knowledge of the domain, the classification task, and the class labels. Our findings demonstrate the potential for achieving computational phenotype discovery at population scale. We expect such data

  19. Disordered Eating, Menstrual Irregularity, and Musculoskeletal Injury in High School Athletes

    Science.gov (United States)

    Thein-Nissenbaum, Jill M.; Carr, Kathleen E.; Hetzel, Scott; Dennison, Emily

    2014-01-01

    Background: The female athlete triad is the interrelatedness of energy availability, menstrual function, and bone density. Currently, limited information about triad components and their relationship to musculoskeletal injury in the high school population exists. In addition, no study has specifically examined triad components and injury rate in high school oral contraceptive pill (OCP) users. Hypothesis: To compare the prevalence of disordered eating (DE), menstrual irregularity (MI), and musculoskeletal injury (INJ) among high school female athletes in OCP users and non-OCP users. Study Design: Retrospective cohort study. Level of Evidence: Level 2. Methods: The subject sample completed the Eating Disorder Examination-Questionnaire (EDE-Q) and Healthy Wisconsin High School Female Athletes Survey (HWHSFAS). Athletes were classified by OCP use and sport type. Results: Of the participants, 14.8% reported OCP use. There was no difference in MI and INJ among groups. The prevalence of DE was significantly higher among OCP users as compared with non-OCP users; OCP users were twice as likely to meet the criteria for DE (odds ratio [OR], 2.47; 95% confidence interval [CI], 1.20-5.09). OCP users were over 5 times more likely to have a global score that met criteria for DE as compared with non-OCP users (OR, 5.36; 95% CI, 1.92-14.89). Conclusion: Although MI and INJ rates are similar among groups, there is a higher prevalence of DE among high school female athletes using OCPs as compared with non-OCP users. Clinical Relevance: Because OCP users may be menstruating, clinicians may fail to recognize the other triad components. However, DE exists in the menstruating OCP user. As such, clinicians should be vigilant when screening for triad components in high school OCP users, particularly DE. PMID:24982703

  20. On collisional capture rates of irregular satellites around the gas-giant planets and the minimum mass of the solar nebula

    Science.gov (United States)

    Koch, F. Elliott; Hansen, Bradley M. S.

    2011-09-01

    We investigate the probability that an inelastic collision of planetesimals within the Hill sphere of the Jovian planets could explain the presence and orbits of observed irregular satellites. Capture of satellites via this mechanism is highly dependent on not only the mass of the protoplanetary disc, but also the shape of the planetesimal size distribution. We performed 2000 simulations for integrated time intervals ˜2 Myr and found that, given the currently accepted value for the minimum mass solar nebula and planetesimal number density based upon the Nesvorný et al. and Charnoz & Morbidelli size distribution dN˜D-3.5dD, the collision rates for the different Jovian planets range between ˜0.6 and ≳170 Myr-1 for objects with radii 1 km ≤r≤ 10 km. Additionally, we found that the probability that these collisions remove enough orbital energy to yield a bound orbit was ≲10-5 and had very little dependence on the relative size of the planetesimals. Of these collisions, the collision energy between two objects was ≳103 times the gravitational binding energy for objects with radii ˜100 km. We find that capturing irregular satellites via collisions between unbound objects can only account for ˜0.1 per cent of the observed population, hence this cannot be the sole method of producing irregular satellites.

  1. Excitation thresholds of field-aligned irregularities and associated ionospheric hysteresis at very high latitudes observed using SPEAR-induced HF radar backscatter

    Directory of Open Access Journals (Sweden)

    D. M. Wright

    2009-07-01

    Full Text Available On 10 October 2006 the SPEAR high power radar facility was operated in a power-stepping mode where both CUTLASS radars were detecting backscatter from the SPEAR-induced field-aligned irregularities (FAIs. The effective radiated power of SPEAR was varied from 1–10 MW. The aim of the experiment was to investigate the power thresholds for excitation (Pt and collapse (Pc of artificially-induced FAIs in the ionosphere over Svalbard. It was demonstrated that FAI could be excited by a SPEAR ERP of only 1 MW, representing only 1/30th of SPEAR's total capability, and that once created the irregularities could be maintained for even lower powers. The experiment also demonstrated that the very high latitude ionosphere exhibits hysteresis, where the down-going part of the power cycle provided a higher density of irregularities than for the equivalent part of the up-going cycle. Although this second result is similar to that observed previously by CUTLASS in conjunction with the Tromsø heater, the same is not true for the equivalent incoherent scatter measurements. The EISCAT Svalbard Radar (ESR failed to detect any hysteresis in the plasma parameters over Svalbard in stark contract with the measurements made using the Tromsø UHF.

  2. Modelling and Predicting the Breaking Strength and Mass Irregularity of Cotton Rotor-Spun Yarns Containing Cotton Fiber Recovered from Ginning Process by Using Artificial Neural Network Algorithm

    Directory of Open Access Journals (Sweden)

    Mohsen Shanbeh

    2011-01-01

    Full Text Available One of the main methods to reduce the production costs is waste recycling which is the most important challenge for the future. Cotton wastes collected from ginning process have desirable properties which could be used during spinning process. The purpose of this study was to develop predictive models of breaking strength and mass irregularity (CV% of cotton waste rotor-spun yarns containing cotton waste collected from ginning process by using the artificial neural network trained with backpropagation algorithm. Artificial neural network models have been developed based on rotor diameter, rotor speed, navel type, opener roller speed, ginning waste proportion and yarn linear density as input parameters. The parameters of artificial neural network model, namely, learning, and momentum rate, number of hidden layers and number of hidden processing elements (neurons were optimized to get the best predictive models. The findings showed that the breaking strength and mass irregularity of rotor spun yarns could be predicted satisfactorily by artificial neural network. The maximum error in predicting the breaking strength and mass irregularity of testing data was 8.34% and 6.65%, respectively.

  3. From experience: applying the risk diagnosing methodology

    NARCIS (Netherlands)

    Keizer, Jimme A.; Halman, Johannes I.M.; Song, Michael

    2002-01-01

    No risk, no reward. Companies must take risks to launch new products speedily and successfully. The ability to diagnose and manage risks is increasingly considered of vital importance in high-risk innovation. This article presents the Risk Diagnosing Methodology (RDM), which aims to identify and

  4. De dokter en de diagnose-verzamelaar

    NARCIS (Netherlands)

    Geersing, Geert-Jan

    2015-01-01

    In the course of the medical curriculum, medical students are trained to recognise diagnoses. They classify these in their minds, together with detailed information on laboratory and imaging tests, as collections of diagnoses. The downside of this could be overdiagnosis. This paper describes some of

  5. From experience: applying the risk diagnosing methodology

    NARCIS (Netherlands)

    Keizer, Jimme A.; Halman, Johannes I.M.; Song, Michael

    2002-01-01

    No risk, no reward. Companies must take risks to launch new products speedily and successfully. The ability to diagnose and manage risks is increasingly considered of vital importance in high-risk innovation. This article presents the Risk Diagnosing Methodology (RDM), which aims to identify and eva

  6. Reliability of clinical ICD-10 schizophrenia diagnoses

    DEFF Research Database (Denmark)

    Jakobsen, Klaus D; Frederiksen, Julie N; Hansen, Thomas;

    2005-01-01

    value (87%) of ICD-10 schizophrenia and an overall good agreement between clinical and OPCRIT-derived diagnoses (kappa=0.60). An even higher positive predictive value was obtained when diagnoses were amalgamated into a diagnostic entity of schizophrenia-spectrum disorders (98%). Near perfect agreement...

  7. Radio Scintillation due to Discontinuities in the Interstellar Plasma Density

    CERN Document Server

    Lambert, H; Lambert, Hendrik; Rickett, Barney

    1999-01-01

    We develop the theory of interstellar scintillation as caused by an irregular plasma having a power-law spatial density spectrum with a spectral exponent of 4 corresponding to a medium with abrupt changes in its density. An ``outer scale'' is included in the model representing the typical scale over which the density of the medium remains uniform. Such a spectrum could be used to model plasma shock fronts in supernova remnants or other plasma discontinuities. We investigate and develop equations for the decorrelation bandwidth of diffractive scintillations and the refractive scintillation index and compare our results with pulsar measurements. We consider both a medium concentrated in a thin layer and an extended irregular medium. We conclude that the discontinuity model gives satisfactory agreement for many diffractive measurements, in particular the VLBI meaurements of the structure function exponent between 5/3 and 2. However, it gives less satisfactory agreement for the refractive scintillation index than...

  8. Distributed Particle Filter Implementation with Intermittent/Irregular Consensus Convergence

    CERN Document Server

    Mohammadi, Arash

    2011-01-01

    Motivated by non-linear, non-Gaussian, distributed multi-sensor/agent navigation and tracking applications, we propose a multi-rate consensus/fusion based framework for distributed implementation of the particle filter (CF/DPF). The CF/DPF framework is based on running localized particle filters to estimate the overall state vector at each observation node. Separate fusion filters are designed to consistently assimilate the local filtering distributions into the global posterior by compensating for the common past information between neighbouring nodes. The CF/DPF offers two distinct advantages over its counterparts. First, the CF/DPF framework is suitable for scenarios where network connectivity is intermittent and consensus can not be reached between two consecutive observations. Second, the CF/DPF is not limited to the Gaussian approximation for the global posterior density. A third contribution of the paper is the derivation of the optimal posterior Cram\\'er-Rao lower bound (PCRLB) for the distributed arc...

  9. SU-C-210-03: Impact of Breathing Irregularities On Gated Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Schiuma, D; Arheit, M; Schmelzer, P; Scheib, S [Varian Medical Systems, Imaging Laboratory GmbH, Baden-Daettwil (Switzerland); Buchsbaum, T; Pemler, P [Radioonkologie, Stadtspital Triemli, Zurich (Switzerland)

    2015-06-15

    Purpose: To evaluate the effect of breathing irregularities on target location in gated treatments using amplitude and phase gating. Methods: 111 breathing patterns acquired using RPM system were categorized based on period and amplitude STD as regular (STD period ≤ 0.5 s, STD amplitude ≤ 1.5 mm), medium (0.5 s < STD period ≤ 1 s, 1.5 mm < STD amplitude ≤ 3 mm) and irregular (STD period > 1 s, STD amplitude > 3 mm). One pattern representative of the average defined population was selected per category and corresponding target motion reproduced using Quasar Respiratory Motion Phantom. Phantom in motion underwent 4D-CT scan with phase reconstruction. Gated window was defined at end of exhale and DRRs reconstructed in treatment planning at 40% (beam on) and 60% phase (beam off). Target location uncertainty was assessed by comparing gated kV triggered images continuously acquired at beam on/off on a True Beam 2.0 with corresponding DRRs. Results: Average target uncertainty with amplitude gating was in [0.4 – 1.9] mm range for the different scenarios with maximum STD of 1.2 mm for the irregular pattern. Average target uncertainty with phase gating was [1.1 – 2.2] mm for regular and medium patterns, while it increased to [3.6 – 9.6] mm for the irregular pattern. Live gated motion was stable with amplitude gating, while increasing with phase gating for the irregular pattern. Treatment duration range was [68 – 160] s with amplitude and [70 – 74] s with phase gating. Conclusion: Breathing irregularities were found to affect gated treatments only when using phase gating. For regular and medium patterns no significant difference was found between the two gating strategies. Amplitude gating ensured stable gated motion within the different patterns, thus reducing intra-fraction target location variability for the irregular pattern and resulting in longer treatment duration.

  10. Effects of irregular-shift work and physical activity on cardiovascular risk factors in truck drivers.

    Science.gov (United States)

    Marqueze, Elaine Cristina; Ulhôa, Melissa Araújo; Moreno, Claudia Roberta de Castro

    2013-06-01

    To analyze the putative effect of type of shift and its interaction with leisure-time physical activity on cardiovascular risk factors in truck drivers. A cross-sectional study was undertaken on 57 male truck drivers working at a transportation company, of whom 31 worked irregular shifts and 26 worked on the day-shift. Participants recorded their physical activity using the International Physical Activity Questionnaire along with measurements of blood pressure, body mass index and waist-hip ratio. Participants also provided a fasting blood sample for analysis of lipid-related outcomes. Data were analyzed using a factorial model which was covariate-controlled for age, smoking, work demand, control at work and social support. Most of the irregular-shift and day-shift workers worked more than 8 hours per day (67.7% and 73.1%, respectively). The mean duration of experience working the irregular schedule was 15.7 years. Day-shift workers had never engaged in irregular-shift work and had been working as a truck driver for 10.8 years on average. The irregular-shift drivers had lower work demand but less control compared to day-shift drivers (p active irregular-shift workers had higher systolic and diastolic arterial pressures (143.7 and 93.2 mmHg, respectively) than moderately-active day-shift workers (116 and 73.3 mmHg, respectively) (p physical activity, irregular-shift drivers had higher total cholesterol and LDL-cholesterol concentrations (211.8 and 135.7 mg/dl, respectively) than day-shift workers (161.9 and 96.7 mg/dl, respectively (ANCOVA, p physical activity.

  11. Optimizing Chinese character displays improves recognition and reading performance of simulated irregular phosphene maps.

    Science.gov (United States)

    Lu, Yanyu; Kan, Han; Liu, Jie; Wang, Jing; Tao, Chen; Chen, Yao; Ren, Qiushi; Hu, Jie; Chai, Xinyu

    2013-04-26

    A visual prosthesis may elicit an irregular phosphene map relative to a regular electrode array. This study used simulated irregular phosphene maps as a way of optimizing the display methods of Chinese characters (CCs) to improve recognition and reading performance. TWENTY SUBJECTS WITH NORMAL OR CORRECTED SIGHT PARTICIPATED IN TWO EXPERIMENTS (9 FEMALES, 11 MALES, 2030 YEARS OF AGE). EXPERIMENT 1: two character display methods were proposed: selecting phosphenes covered by character strokes on a simulated phosphene array (projection method) and finding the phosphene closest to the expected location in some range of an irregular phosphene array as a substitute (nearest neighbor search [NNS] method). The recognition accuracy of CCs was investigated using six levels for the coverage ratio of stroke and phosphene area and for search range, respectively, for two methods, for several irregularity levels. Experiment 2: reading accuracy (RA) and reading efficiency (RE) were measured using the regular array correspondence and NNS methods. EXPERIMENT 1: projection and NNS methods were significantly affected by coverage ratio or search range. NNS significantly improved CC recognition accuracy to the highest at 81.3 ± 2.7% and 59.1 ± 5.2%, respectively, for different irregularity levels, compared with the projection method. Experiment 2: RA and RE significantly decreased as the distortion level increased; NNS significantly improved RA (from approximately 40% to >80%) and RE (from approximately 13 char/min to >40 char/min) when reading more irregular paragraphs. The performance of CC recognition and paragraph reading when using an irregular phosphene array can be improved through optimizing the display method.

  12. The star formation history of the Sculptor Dwarf Irregular Galaxy

    CERN Document Server

    Lianou, Sophia

    2012-01-01

    [abridged] We study the resolved stellar populations and derive the SFH of the SDIG, a gas-rich dwarf galaxy member of the NGC7793 subgroup in the Sculptor group. We construct a CMD using archival HST observations and examine its stellar content. We derive its SFH using a maximum-likelihood fit to the CMD. The CMD shows that SDIG contains stars from 10Myr to several Gyr old, as revealed from the MS, BL, luminous AGB, and RGB stars. The young stars with ages less than ~250Myr show a spatial distribution confined to its central regions, and additionally the young MS stars exhibit an off-center density peak. The intermediate-age and older stars are more spatially extended. SDIG is dominated by intermediate-age stars with an average age of 6.4Gyr. The average metallicity inferred is [M/H]\\approx -1.5dex. Its SFH is consistent with a constant SFR, except for ages younger than ~200Myr. The lifetime average SFR is 1.3x10^{-3} Mo/yr. More recently than 100Myr, there has been a burst of SF at a rate ~2-3 times higher ...

  13. SEISMIC PROPAGATION SIMULATION IN COMPLEX MEDIA WITH NON-RECTANGULAR IRREGULAR-GRID FINITE-DIFFERENCE

    Institute of Scientific and Technical Information of China (English)

    SUN Weitao; YANG Huizhu

    2004-01-01

    This paper presents a finite-difference (FD) method with spatially non-rectangular irregular grids to simulate the elastic wave propagation. Staggered irregular grid finite difference operators with a second-order time and spatial accuracy are used to approximate the velocity-stress elastic wave equations. This method is very simple and the cost of computing time is not much. Complicated geometries like curved thin layers, cased borehole and nonplanar interfaces may be treated with nonrectangular irregular grids in a more flexible way. Unlike the multi-grid scheme, this method requires no interpolation between the fine and coarse grids and all grids are computed at the same spatial iteration. Compared with the rectangular irregular grid FD, the spurious diffractions from "staircase"interfaces can easily be eliminated without using finer grids. Dispersion and stability conditions of the proposed method can be established in a similar form as for the rectangular irregular grid scheme. The Higdon's absorbing boundary condition is adopted to eliminate boundary reflections. Numerical simulations show that this method has satisfactory stability and accuracy in simulating wave propagation near rough solid-fluid interfaces. The computation costs are less than those using a regular grid and rectangular grid FD method.

  14. W_3 irregular states and isolated N=2 superconformal field theories

    CERN Document Server

    Kanno, Hiroaki; Shiba, Shotaro; Taki, Masato

    2013-01-01

    We explore the proposal that the six-dimensional (2,0) theory on the Riemann surface with irregular punctures leads to a four-dimensional gauge theory coupled to the isolated N=2 superconformal theories of Argyres-Douglas type, and to two-dimensional conformal field theory with irregular states. Following the approach of Gaiotto-Teschner for the Virasoro case, we construct W_3 irregular states by colliding a single SU(3) puncture with several regular punctures of simple type. If n simple punctures are colliding with the SU(3) puncture, the resulting irregular state is a simultaneous eigenvector of the positive modes L_n, ..., L_{2n} and W_{2n}, ..., W_{3n} of the W_3 algebra. We find the corresponding isolated SCFT with an SU(3) flavor symmetry as a nontrivial IR fixed point on the Coulomb branch of the SU(3) linear quiver gauge theories, by confirming that its Seiberg-Witten curve correctly predicts the conditions for the W_3 irregular states. We also show that these SCFT's are identical to the ones obtained...

  15. {{{W}}_3} irregular states and isolated {N}=2 superconformal field theories

    Science.gov (United States)

    Kanno, Hiroaki; Maruyoshi, Kazunobu; Shiba, Shotaro; Taki, Masato

    2013-03-01

    We explore the proposal that the six-dimensional (2, 0) theory on the Riemann surface with irregular punctures leads to a four-dimensional gauge theory coupled to the isolated {N}=2 superconformal theories of Argyres-Douglas type, and to two-dimensional conformal field theory with irregular states. Following the approach of Gaiotto-Teschner for the Virasoro case, we construct {{{W}}_3} irregular states by colliding a single SU(3) puncture with several regular punctures of simple type. If n simple punctures are colliding with the SU(3) puncture, the resulting irregular state is a simultaneous eigenvector of the positive modes L n , . . . , L 2 n and W 2 n , . . . , W 3 n of the {{{W}}_3} algebra. We find the corresponding isolated SCFT with an SU(3) flavor symmetry as a nontrivial IR fixed point on the Coulomb branch of the SU(3) linear quiver gauge theories, by confirming that its Seiberg-Witten curve correctly predicts the conditions for the {{{W}}_3} irregular states. We also compare these SCFT's with the ones obtained from the BPS quiver method.

  16. 30 MHz radar observations of artificial E region field-aligned plasma irregularities

    Directory of Open Access Journals (Sweden)

    D. L. Hysell

    2008-02-01

    Full Text Available Artificial E region field aligned irregularities (FAIs have been observed during heating experiments at the HAARP facility using a new 30 MHz coherent scatter radar imager deployed near Homer, Alaska. Irregularities were observed during brief experiments on three quiet days in July and August, 2007, when the daytime E region critical frequency was close to 3 MHz. Irregularities were consistently generated and detected during experiments with O-mode HF pumping on zenith with a 1-min on, 1-min off CW modulation. The scattering cross sections, rise, and fall times of the echoes were observed as well as their spectral properties. Results were found to be mainly in agreement with observations from other mid- and high-latitude sites with some discrepancies. Radar images of the irregularity-filled volume on one case exhibited clear variations in backscatter power and Doppler shift across the volume. The images furthermore show the emergence of a small irregularity-filled region to the south southwest of the main region in the approximate direction of magnetic zenith.

  17. Dispositional resilience as a moderator of the relationship between chronic stress and irregular menstrual cycle.

    Science.gov (United States)

    Palm-Fischbacher, Simona; Ehlert, Ulrike

    2014-06-01

    Menstrual-cycle irregularity may have an important influence on the subsequent development of chronic diseases. Several risk factors for irregular menstrual cycles have been detected, including stress. Our aim was to extend research on the link between chronic stress and menstrual-cycle irregularity and to assess potential protective factors, such as dispositional resilience, which we hypothesize to be associated with the maintenance or promotion of a healthy menstrual cycle. For this cross-sectional study, data on 696 healthy women aged 20-40 years were obtained. The women completed measures of chronic stress, dispositional resilience and menstrual-cycle irregularity. Furthermore, potential confounds were assessed. Of the participants, 383 (55%) reported no current use of hormonal contraceptives; 313 (45%) reported current use hormonal contraception and were included as a control group. The results suggest that in women not using hormonal contraception, chronic stress (OR = 1.05, 95%CI = 1.02-1.08, p = 0.001) and dispositional resilience (OR = 0.43, 95%CI = 0.31-0.59, p menstrual cycle regularity. In addition, women with greater dispositional resilience have reduced risk for irregular menstrual cycles in the face of low to moderate chronic stress; however, this association is changed at the highest level of chronic stress. These findings suggest that dispositional resilience may be a protective psychological trait that modulates reproductive functioning.

  18. Morning Cortisol Levels and Perceived Stress in Irregular Shift Workers Compared with Regular Daytime Workers

    Directory of Open Access Journals (Sweden)

    Harri Lindholm

    2012-01-01

    Full Text Available The 24/7 work environment and irregular shifts may markedly enhance the psychological pressure of media work. Changes in the hypothalamic-pituitary-adrenal axis reflect adaptation to stress. We analysed the correlation between subjective stress, sleep, salivary cortisol, and melatonin hormones among Finnish media workers with regular daytime work (RDW and with irregular shift work (ISW while controlling confounders. From 874 employees with regular daytime work or with irregular shift work, 70 employees from both groups were randomly selected. The final number of employees with a complete salivary cortisol profile was 66 in the RDW group and 65 in the ISW group. Five saliva samples were gathered from each subject before and during a working day. The salivary cortisol level of the sample taken 60 minutes after awakening (T1 was compared to the salivary cortisol level taken immediately after awakening (T0, T1/T0 ratio. The ratio was higher in the ISW group than in RDW group. Irregular shift work (P<0.001, severe stress (P<0.05, and less sleep (P<0.05 were independently associated with an augmented cortisol response after awakening. A stressful work environment and irregular shift work enhance cortisol excretion after waking. In the long run, this may become detrimental to health.

  19. Method of determining effects of heat-induced irregular refractive index on an optical system.

    Science.gov (United States)

    Song, Xifa; Li, Lin; Huang, Yifan

    2015-09-01

    The effects of an irregular refractive index on optical performance are examined. A method was developed to express a lens's irregular refractive index distribution. An optical system and its mountings were modeled by a thermomechanical finite element (FE) program in the predicted operating temperature range, -45°C-50°C. FE outputs were elaborated using a MATLAB optimization routine; a nonlinear least squares algorithm was adopted to determine which gradient equation best fit each lens's refractive index distribution. The obtained gradient data were imported into Zemax for sequential ray-tracing analysis. The root mean square spot diameter, modulation transfer function, and diffraction ensquared energy were computed for an optical system under an irregular refractive index and under thermoelastic deformation. These properties are greatly reduced by the irregular refractive index effect, which is one-third to five-sevenths the size of the thermoelastic deformation effect. Thus, thermal analyses of optical systems should consider not only thermoelastic deformation but also refractive index irregularities caused by inhomogeneous temperature.

  20. Factors associated with irregular breakfast consumption among high school students in a Japanese community.

    Science.gov (United States)

    Oba, Shino; Oogushi, Kazuhiro; Ogata, Hiromitsu; Nakai, Hiromitsu

    2016-01-01

    This study evaluated the associations between the characteristics of high school students and irregular breakfast consumption and explored the association with knowledge regarding diet and dietary education in a community in Japan. A cross-sectional survey using a self-administered questionnaire was conducted in 2007 among all the high school students in the second grade in Imari, Saga. Data for 318 male and 292 female students were analyzed. Irregular breakfast consumption was defined as consuming breakfast three times or less in a week. The associations between the characteristics of students and irregular breakfast consumption were assessed using logistic regression with adjustments for sex and school. Among male students, a strong association between the consumption of juice or pop and irregular breakfast consumption was observed (OR comparing ">=2 servings" vs "rarely"=8.97, 95% CI=2.99-26.9). The associations with wake times and bed times were strong among male students, and the association with regular bowel movements was strong among female students. Students who had knowledge of regional agricultural and livestock products were more likely to consume breakfast regularly, and this association was significant among female students (OR=2.89, 95% CI=1.23-6.82). Significant associations were also observed with the consumption of snacks, and traditional greeting before meals. Several characteristics, including specific knowledge, were associated with the irregular consumption of breakfast. The results are of interest to policy makers, nutrition specialists, and educators working to enhance regular breakfast consumption among students.

  1. Análisis de la evolución temporal de las desigualdades con datos irregulares || Analyzing the Income Inequalities with Irregular Time Series

    Directory of Open Access Journals (Sweden)

    Callealta Barroso, Francisco Javier

    2012-01-01

    Full Text Available En este artículo se proporciona una herramienta que permite estudiar las distribuciones de renta en una población a lo largo del tiempo, sin importar que los datos se distribuyan de forma irregular. Incluso, se posibilita la aproximación de curvas de Lorenz en instantes en los que no se cuenta con los datos necesarios. Finalmente, se presenta un ejemplo de aplicación de la técnica en un país europeo en que las desigualdades son especialmente relevantes: España. || This article provides a tool to study over time the distributions of income in a population, regardless the irregular distribution of data. We even approach Lorenz curves at the times when we lack the required data. Finally we apply the present technique to a European country where inequalities are particularly relevant: Spain.

  2. Distal fibula fracture diagnosed with ultrasound imaging.

    Science.gov (United States)

    Kardouni, Joseph R

    2012-10-01

    The patient was a 31-year-old man serving in a military special forces unit at a remote location. He presented to a physical therapist with a chief complaint of worsening right lateral ankle pain that limited his ability to bear weight. Because the patient met the Ottawa ankle rules and there was concern for a fracture, radiographs were indicated. However, the nearest facility with radiographic capabilities was only available through air medical evacuation. Therefore, the physical therapist assessed the patient's ankle with an onsite portable ultrasound imaging unit, which demonstrated cortical irregularity along the distal fibula.

  3. Diagnosing Asthma in Very Young Children

    Science.gov (United States)

    ... Listen Español Text Size Email Print Share Diagnosing Asthma in Babies & Toddlers Page Content Article Body One ... family with recurrent bronchitis or sinus problems. When Asthma is Not the Cause Your pediatrician will listen ...

  4. How Are Pelvic Floor Disorders Diagnosed?

    Science.gov (United States)

    ... Information Clinical Trials Resources and Publications How are pelvic floor disorders diagnosed? Skip sharing on social media links ... fee ). This test is used to evaluate the pelvic floor and rectum while the patient is having a ...

  5. How Are Overweight and Obesity Diagnosed?

    Science.gov (United States)

    ... body mass index (BMI) and possibly a high waist circumference, and tests to rule out other medical conditions. ... diagnosed as obese if you have a large waist circumference that suggests increased amounts of fat in your ...

  6. How Are Soft Tissue Sarcomas Diagnosed?

    Science.gov (United States)

    ... type of cancer or a benign disease. Several types of biopsies are used to diagnose sarcomas. Doctors experienced with ... But if FNA results suggest a sarcoma, another type of biopsy will usually be done to remove enough tissue ...

  7. How Are Obesity and Overweight Diagnosed?

    Science.gov (United States)

    ... Clinical Trials Resources and Publications How are obesity & overweight diagnosed? Skip sharing on social media links Share ... common way to determine if a person is overweight or obese is to calculate body mass index ( ...

  8. Challenges in diagnosing tuberculosis in children

    DEFF Research Database (Denmark)

    Rahman, Nadia; Pedersen, Karin Kæreby; Nielsen, Vibeke Rosenfeldt

    2012-01-01

    Clinical investigations of childhood tuberculosis (TB) are challenged by the paucibacillary nature of the disease and the difficulties in obtaining specimens. We investigated the challenges in diagnosing TB in children in a low-incidence country.......Clinical investigations of childhood tuberculosis (TB) are challenged by the paucibacillary nature of the disease and the difficulties in obtaining specimens. We investigated the challenges in diagnosing TB in children in a low-incidence country....

  9. Experimental Researches on Reflective and Transmitting Performances of Quarter Circular Breakwater Under Regular and Irregular Waves

    Institute of Scientific and Technical Information of China (English)

    SHI Yan-jiao; WU Mi-ling; JIANG Xue-lian; LI Yan-bao

    2011-01-01

    A series of regular and irregular wave experiments are conducted to study the reflective and transmitting performances of quarter circular breakwater (QCB) in comparison with those of semi-circular breakwater (SCB).Based on regular wave tests,the reflection and transmission characteristics of QCB are analyzed and a few influencing factors are investigated.Then,the wave energy dissipation as wave passing over the breakwater is discussed based on the hydraulic coefficients of QCB and SCB.In irregular wave experiments,the reflection coefficients of QCB and their spectrums are studied.Finally,the comparisons between the experimental results and numerical simulations for QCB under regular and irregular wave conditions are presented.

  10. Improved Multispanning Tree Routing Using Efficient and Reliable Routing Algorithm for Irregular Networks

    Directory of Open Access Journals (Sweden)

    L. Keerthana

    2012-06-01

    Full Text Available A Strategy of Multispanning Tree Zone Ordered Label Based routing is improved with Efficient and Reliable (EAR routing for irregular networks is presented and analyzed in this work. Most existing deadlock free routing methods for irregular topologies impose several limitations on node and channel labeling in an irregular network is based on a pre-defined spanning tree.It is not possible to form a deadlock free zone of three or four channel labels for two spanning tree. So this existing Multispanning Tree Zone Ordered Label Based routing is modified with Efficient and Reliable (EAR routing. EAR is based on four parameters length of the path,distance traversed,transmission of link and energy levels to dynamically determine and maintain the best routes.. The simulation results have shown highest packet delivery ratio, minimum latency, and energy consumption.

  11. Energy Extraction from a Slider-Crank Wave Energy under Irregular Wave Conditions: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Sang, Yuanrui; Karayaka, H. Bora; Yan, Yanjun; Zhang, James Z.; Muljadi, Eduard; Yu, Yi-Hsiang

    2015-08-24

    A slider-crank wave energy converter (WEC) is a novel energy conversion device. It converts wave energy into electricity at a relatively high efficiency, and it features a simple structure. Past analysis on this particular WEC has been done under regular sinusoidal wave conditions, and suboptimal energy could be achieved. This paper presents the analysis of the system under irregular wave conditions; a time-domain hydrodynamics model is adopted and a rule-based control methodology is introduced to better serve the irregular wave conditions. Results from the simulations show that the performance of the system under irregular wave conditions is different from that under regular sinusoidal wave conditions, but a reasonable amount of energy can still be extracted.

  12. Implied Evolutionary Differences of the Jovian Irregular Satellites from a BVR Color Survey

    Science.gov (United States)

    Rettig, Terrence W.; Walsh, Kevin; Consolmagno, Guy

    2001-12-01

    We present BVR colors and magnitudes for four jovian irregular prograde satellites (Himalia J6, Elara J7, Lysithea J10, and Leda J13) and four irregular retrograde satellites (Pasiphae J8, Sinope J9, Carme J11, and Ananke J12). All eight have generally 'solar' colors but the retrograde group has slightly redder and more diverse colors. The strikingly similar colors of the four prograde satellites suggest the parent planetesimal was likely very homogeneous. The four retrograde satellites show a diversity in color that suggests a heterogeneous progenitor and thus variations in precapture formation history. The absolute magnitudes and revised diameters are presented. We also report new colors and diameters for two uranian irregular satellites (Caliban (S/1997 U1) and Sycorax (S/1997 U2) that are slightly redder than any of these jovian satellites.

  13. Suction-based grasping tool for removal of regular- and irregular-shaped intraocular foreign bodies.

    Science.gov (United States)

    Erlanger, Michael S; Velez-Montoya, Raul; Mackenzie, Douglas; Olson, Jeffrey L

    2013-01-01

    To describe a suction-based grasping tool for the surgical removal of irregular-shaped and nonferromagnetic intraocular foreign bodies. A surgical tool with suction capabilities, consisting of a stainless steel shaft with a plastic handle and a customizable and interchangeable suction tip, was designed in order to better engage and manipulate irregular-shaped in-traocular foreign bodies of various sizes and physical properties. The maximal suction force and surgical capabilities were assessed in the laboratory and on a cadaveric eye vitrectomy model. The suction force of the water-tight seal between the intraocular foreign body and the suction tip was estimated to be approximately 40 MN. During an open-sky vitrectomy in a porcine model, the device was successful in engaging and firmly securing foreign bodies of different sizes and shapes. The suction-based grasping tool enables removal of irregular-shaped and nonferromagnetic foreign bodies. Copyright 2013, SLACK Incorporated.

  14. Detection of a Solitude Senior's Irregular States Based on Learning and Recognizing of Behavioral Patterns

    Science.gov (United States)

    Aoki, Shigeki; Onishi, Masaki; Kojima, Atsuhiro; Fukunaga, Kunio

    Recently, attention is paid to monitoring systems that watch behavior of a solitude person in home as the population of solitude seniors has increased. This paper proposes a monitoring system focused on behavioral patterns of a solitude senior. In general, the number of behavioral patterns are limited in the case of aged person in a room. It is possible for a system like a HMM to learn the frequently appeared behavioral patterns. By utilizing HMMs to deal with behavioral patterns, the system can detect irregular pattern by the degree of likelihood in the case when non-daily behavioral patterns appeared. Such a case could be an irregular state of the living life of the person. Soon after, the system reports an alarm of occurrence of the irregular state according to demand.

  15. Spinning Dust Emission: Effects of irregular grain shape, transient heating and comparison with WMAP results

    CERN Document Server

    Hoang, Thiem; Draine, B T

    2011-01-01

    Planck is expected to answer crucial questions on the early Universe, but it also provides further understanding on anomalous microwave emission. Electric dipole emission from spinning dust grains continues to be the favored interpretation of anomalous microwave emission. In this paper, we present a method to calculate the rotational emission from small grains of irregular shape with moments of inertia $I_{1}\\ge I_{2}\\ge I_{3}$. We show that a torque-free rotating irregular grain with a given angular momentum radiates at multiple frequency modes. The resulting spinning dust spectrum has peak frequency and emissivity increasing with the degree of grain shape irregularity, which is defined by $I_{1}:I_{2}:I_{3}$. We discuss how the orientation of dipole moment $\\bmu$ in body coordinates affects the spinning dust spectrum for different regimes of internal thermal fluctuations. We show that the spinning dust emissivity for the case of strong thermal fluctuations is less sensitive to the orientation of $\\bmu$ than...

  16. Influence of Track Irregularity on Longitudinal Vibration of Wheelset and Correlation Performance

    Institute of Scientific and Technical Information of China (English)

    Ma Weihua; Luo Shihui; Song Rongrong

    2006-01-01

    Longitudinal vibration of wheelset with respect to bogie frame often exists with a high acceleration magnitude and relative high frequency. First, a simplified model with a single wheelset moving at a constant speed on a tangential track with irregularity is used to investigate the longitudinal vibration dynamics. Computational results indicate that the longitudinal vibration frequency of the wheelset is most sensitive to the primary longitudinal stiffness and the mass of the wheelset. As to the locomotive model, the longitudinal vibration is concerned with cross-level irregularity and vertical profile irregularity. Meanwhile, a method to estimate the resonance speed is presented. Finally, a possible solution is brought forward to extend wheel-rail service life by eliminating longitudinal vibration of the wheelset. The solution is simply to arrang the primary vertical damper with a forward angle, so that its damping component can be applied to longitudinal direction.

  17. Institutional Root Cause of the Irregularity of Social Security Funds in China

    Institute of Scientific and Technical Information of China (English)

    Bingwen Zheng

    2007-01-01

    This paper analyzes institutional defects in the Chinese social security system, based on irregularities in social security funds revealed in the Audit Report by the China National Audit Office. The author divides the irregularities into five categories according to the nature of fund use. The results show that the institutional root cause of the irregularities lies in the unreasonable design and operation of the social security system, which currently faces management and institutional risks. This paper argues that simple rhetoric about strengthening regulation and supervision cannot help to reduce illegal practices, or to realize risk control. The only solution is to reform the social security system. Specifically, the Chinese Government should regulate the administrative cost of the social security system,and the behavior of its agencies, through legislation, reform the investment regime to increase rate of return of pension assets, and adjust and reshape the existing social security system, so as to elevate its pooling level.

  18. Vulnerability, irregular migrants' health-related rights and the European Court of Human Rights.

    Science.gov (United States)

    Da Lomba, Sylvie

    2014-09-01

    The protection of irregular migrants' health-related rights brings to the fore the tensions that exist between human rights, citizenship and the sovereign state, and exposes the protection gaps in the international human rights regime. With this in mind, I consider the merits of a vulnerability analysis in international human rights law (IHRL). I posit that, detached from specific groups and reconceptualised as universal, vulnerability can be reclaimed as a foundation and tool of IHRL. I further contend that the deployment of a vulnerability analysis can alleviate the exclusionary dimension of IHRL and extend protections to irregular migrants. On this basis, I investigate the development of a vulnerability analysis in the case law of the European Court of Human Rights. I argue that, in contrast with the Court's vulnerable population approach, a vulnerability analysis can improve protection standards for irregular migrants in the field of health.

  19. A Novel Energy Yields Calculation Method for Irregular Wind Farm Layout

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; Soltani, Mohsen;

    2015-01-01

    Due to the increasing size of offshore wind farm, the impact of the wake effect on energy yields become more and more evident. The Seafloor topography would limit the layout of the wind farm so that irregular layout is usually adopted inlarge scale offshore wind farm. However, the calculation...... for the energy yields in irregular wind farm considering wake effect would be difficult.In this paper, a mathematical model which includes the impacts of the variation of both wind direction and velocityon wake effect is established. Based on the wake model, a binary matrix method is proposed for the energy...... yields calculation forirregular wind farms.The results show that the proposed wake model is effective in calculating the wind speeddeficit. The calculation framework is applicable for energy yields calculation in irregular wind farms....

  20. Spiking irregularity and frequency modulate the behavioral report of single-neuron stimulation.

    Science.gov (United States)

    Doron, Guy; von Heimendahl, Moritz; Schlattmann, Peter; Houweling, Arthur R; Brecht, Michael

    2014-02-01

    The action potential activity of single cortical neurons can evoke measurable sensory effects, but it is not known how spiking parameters and neuronal subtypes affect the evoked sensations. Here, we examined the effects of spike train irregularity, spike frequency, and spike number on the detectability of single-neuron stimulation in rat somatosensory cortex. For regular-spiking, putative excitatory neurons, detectability increased with spike train irregularity and decreasing spike frequencies but was not affected by spike number. Stimulation of single, fast-spiking, putative inhibitory neurons led to a larger sensory effect compared to regular-spiking neurons, and the effect size depended only on spike irregularity. An ideal-observer analysis suggests that, under our experimental conditions, rats were using integration windows of a few hundred milliseconds or more. Our data imply that the behaving animal is sensitive to single neurons' spikes and even to their temporal patterning.

  1. Irregular Wave Energy Extraction Analysis for a Slider Crank WEC Power Take-Off System

    Energy Technology Data Exchange (ETDEWEB)

    Sang, Yuanrui; Karayaka, H. Bora; Yan, Yanjun; Zhang, James Z.; Muljadi, Eduard

    2015-09-02

    Slider crank Wave Energy Converter (WEC) is a novel energy conversion device. It converts wave energy into electricity at a relatively high efficiency, and it features a simple structure. Past analysis on this WEC has been done under regular sinusoidal wave conditions, and a suboptimal energy could be achieved. This paper presents the analysis of the system under irregular wave conditions; a time-domain hydrodynamics model is adopted and the control methodology is modified to better serve the irregular wave conditions. Results from the simulations show that the performance of the system under irregular wave conditions is different from that under regular sinusoidal wave conditions, but still a reasonable amount of energy can be extracted.

  2. Moduli of unramified irregular singular parabolic connections on a smooth projective curve

    CERN Document Server

    Inaba, Michi-aki

    2012-01-01

    In this paper we construct a coarse moduli scheme of stable unramified irregular singular parabolic connections on a smooth projective curve and prove that the constructed moduli space is smooth and has a symplectic structure. Moreover we will construct the moduli space of generalized monodromy data coming from topological monodromies, formal monodromies, links and Stokes data associated to the generic irregular connections. We will prove that for a generic choice of generalized local exponents, the generalized Riemann-Hilbert correspondence from the moduli space of the connections to the moduli space of the associated generalized monodromy data gives an analytic isomorphism. This shows that differential systems arising from (generalized) isomonodromic deformations of corresponding unramified irregular singular parabolic connections admit geometric Painlev\\'e property as in the regular singular cases proved generally in \\cite{Inaba-1}.

  3. Decoding Complexity of Irregular LDGM-LDPC Codes Over the BISOM Channels

    CERN Document Server

    Raina, Manik

    2010-01-01

    An irregular LDGM-LDPC code is studied as a sub-code of an LDPC code with some randomly \\emph{punctured} output-bits. It is shown that the LDGM-LDPC codes achieve rates arbitrarily close to the channel-capacity of the binary-input symmetric-output memoryless (BISOM) channel with bounded \\emph{complexity}. The measure of complexity is the average-degree (per information-bit) of the check-nodes for the factor-graph of the code. A lower-bound on the average degree of the check-nodes of the irregular LDGM-LDPC codes is obtained. The bound does not depend on the decoder used at the receiver. The stability condition for decoding the irregular LDGM-LDPC codes over the binary-erasure channel (BEC) under iterative-decoding with message-passing is described.

  4. Topography-Dependent Eikonal Traveltime Tomography for Upper Crustal Structure Beneath an Irregular Surface

    Science.gov (United States)

    Ma, Ting; Zhang, Zhongjie

    2015-06-01

    Seismic modeling of the crust with nonflat topography can be made by first-arrival traveltime tomography, which faces the challenge of an irregular free surface. A feasible way to deal with this problem consists of expanding the physical space by overlapping a low velocity layer above the irregular surface in order to have a flat topography, besides using the classical eikonal equation solver for traveltime computation. However, the undesirable consequences of this method include seismic ray deviations due to the transition from an irregular surface that is the free boundary to an inner discontinuity lying in the expanded computational space. An alternative solution, called irregular surface flattening, which involves the transformation between curvilinear and Cartesian coordinate systems, has been recently proposed through the formulation of the topography-dependent eikonal equation (TDEE) and a new solver for forward modeling of traveltimes. Based on the solution of this equation, we present topography-dependent eikonal traveltime tomography (hereafter TDETT) for seismic modeling of the upper crust. First-arrival traveltimes are calculated using the TDEE solver and the raypaths with the minimum traveltime that can be found by following the steepest traveltime gradient from the receiver to the source. By solving an algebraic equation system that connects the slowness perturbations with the already determined traveltimes, these variables can be obtained making use of the back-projection algorithm. This working scheme is evaluated through three numerical examples with different topographic complexities that are conducted from synthetic data and a fourth example with somewhat more complicated topography and real data acquired in northeastern Tibet. The comparison of the results obtained by both methods, i.e., physical space expansion above the irregular surface and irregular surface flattening, fully validates the tomography scheme that is proposed to construct

  5. Turbulent boundary layers under irregular waves and currents: Experiments and the equivalent-wave concept

    Science.gov (United States)

    Yuan, Jing

    2016-04-01

    A full-scale experimental study of turbulent boundary layer flows under irregular waves and currents is conducted with the primary objective to investigate the equivalent-wave concept by Madsen (1994). Irregular oscillatory flows following the bottom-velocity spectrum under realistic surface irregular waves are produced over two fixed rough bottoms in an oscillatory water tunnel, and flow velocities are measured using a Particle Image Velocimetry. The root-mean-square (RMS) value and representative phase lead of wave velocities have vertical variations very similar to those of the first-harmonic velocity of periodic wave boundary layers, e.g., the RMS wave velocity follows a logarithmic distribution controlled by the physical bottom roughness in the very near-bottom region. The RMS wave bottom shear stress and the associated representative phase lead can be accurately predicted using the equivalent-wave approach. The spectra of wave bottom shear stress and boundary layer velocity are found to be proportional to the spectrum of free-stream velocity. Currents in the presence of irregular waves exhibit the classic two-log-profile structure with the lower log-profile controlled by the physical bottom roughness and the upper log-profile controlled by a much larger apparent roughness. Replacing the irregular waves by their equivalent sinusoidal waves virtually makes no difference for the coexisting currents. These observations, together with the excellent agreement between measurements and model predictions, suggest that the equivalent-wave representation adequately characterizes the basic wave-current interaction under irregular waves.

  6. Characteristics of Scour and Deposition in Front of Breakwaters Under Irregular Broken Clapotis

    Institute of Scientific and Technical Information of China (English)

    高学平; 张亚; 李昌良

    2004-01-01

    First the scour and deposition patterns of the sandy seabed in front of a vertical breakwater under the action of irregular broken clapotis are investigated experimentally and classified into five types: scour type Ⅰ , scour type Ⅱ , scour typeⅢ, deposition type Ⅰ , and deposition type Ⅱ . Secondly, the processes of formation of scour and deposition patterns are probed in comparison with those induced by regular broken clapotis and standing waves. Thirdly, the criteria for distinguishing scour and deposition patterns under irregular broken clapotis are presented.

  7. Proceso de formación de asentamientos irregulares en Guadalajara

    OpenAIRE

    Ruiz-Velasco, Guadalupe; Solinís, Germán

    1988-01-01

    Se expone el proceso social desencadenado durante la formación de siete asentamientos irregulares en la zona metropolitana de Guadalajara: Lomas de Tabachines, Lomas de Oblatos, Hernández Loza, Lázaro Cárdenas, Mezquitera, Nueva España y Agrícola. Se expone la organización social y política que supone la formación de asentamientos irregulares, desde su comercialización ilegal hasta su inclusión en la estructura urbana formal, revisando también los aspectos concretos de la vivienda como expres...

  8. A Tire Model for Off-Highway Vehicle Simulation on Short Wave Irregular Terrain

    DEFF Research Database (Denmark)

    Langer, Thomas Heegaard; Kristensen, Lars B; Mouritsen, Ole Ø.

    2010-01-01

    Manufacturers of construction machinery are challenged in several ways concerning dynamic loads. Considering off-highway dump trucks that travel through high amplitude short wave irregular terrain with considerable speed two aspects concerning dynamics are important. The first is the legal...... the tire ground interaction for big off-road tires on short wave irregular terrain. In this paper a simple tire model combining the well known slip theory and a displaced volume approach is presented. A non-gradient optimization routine is applied for parameter identification by minimizing the difference...

  9. Experimental study on bed-load sediment transport under irregular wave and current combined flow

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Using an irregularly oscillating tray and flume, a series of experiments are completed to evaluate bed-load sediment transport rate under irregular wave- current coexistent fild. Testing conditions include three interaction angles 0°, 45°, 90° and two kinds of median sizes (0.38 and 1.10 mm).The results of transport rate show that the net sediment transport rate can be expressed approximately as the function of the maximum bottom shear stress of waves, mean shear stress of current and the grain size.

  10. Attitude Analysis and Robust Adaptive Backstepping Sliding Mode Control of Spacecrafts Orbiting Irregular Asteroids

    Directory of Open Access Journals (Sweden)

    Chunhui Liang

    2014-01-01

    Full Text Available Attitude stability analysis and robust control algorithms for spacecrafts orbiting irregular asteroids are investigated in the presence of model uncertainties and external disturbances. Rigid spacecraft nonlinear attitude models are considered and detailed attitude stability analysis of spacecraft subjected to the gravity gradient torque in an irregular central gravity field is included in retrograde orbits and direct orbits using linearized system model. The robust adaptive backstepping sliding mode control laws are designed to make the attitude of the spacecrafts stabilized and responded accurately to the expectation in the presence of disturbances and parametric uncertainties. Numerical simulations are included to illustrate the spacecraft performance obtained using the proposed control laws.

  11. Discrete transfer method with the concept of blocked-off region for irregular geometries

    Energy Technology Data Exchange (ETDEWEB)

    Talukdar, Prabal [Institute of Fluid Mechanics (LSTM), University of Erlangen-Nuremberg, Cauerstrasse 4, D-91058 Erlangen (Germany)]. E-mail: prabal_iitg@yahoo.com

    2006-03-15

    The discrete transfer method (DTM) is applied to irregular geometries with a concept of blocked-off region previously applied in the problems of computational fluid dynamics. This gives a new alternative to the DTM for its implementation to irregular structures. The Cartesian coordinate-based ray-tracing algorithm can be applied to the geometries with inclined or curved boundaries. Some test problems are considered and results are validated with the available results in the literature. Both radiative and non-radiative equilibrium situations are considered. The medium is assumed to be both participating and non-participating. Results are found to be accurate for all kinds of situations.

  12. Effect of Body Acceleration on Pulsatile Flow of Micropolar Fluid through an Irregular Arterial Stenosis

    Science.gov (United States)

    Abdullah, Ilyani; Amin, Norsarahaida

    2008-01-01

    The present study deals with the effect of body acceleration together with surface irregularities on blood flow in artery. Prolonged exposure to high level unintended acceleration may cause serious health problems in the cardiovascular system. The situations like riding in vehicles, flying in airplanes and fast body movements during sport activities can lead to the impairment of certain physiological functions. A micropolar model of blood flow through an irregular arterial stenosis is considered. The governing equations involving unsteady nonlinear two-dimensional partial differential equations are solved employing finite difference scheme. Computational results on the velocity profiles and the flow characteristics are presented.

  13. Less Efficient Neural Processing Related to Irregular Sleep and Less Sustained Attention in Toddlers.

    Science.gov (United States)

    Hoyniak, Caroline P; Petersen, Isaac T; McQuillan, Maureen E; Staples, Angela D; Bates, John E

    2015-01-01

    The current study used event-related potentials to examine a candidate process through which sleep difficulties affect attentional processing in toddlers. Fifteen toddlers participated in an auditory Oddball task while neurophysiological data were collected. Sleep deficits were assessed using actigraphs, and attention was examined with a sustained attention task. A P3-like component was elicited from the toddlers, and longer target P3 latencies were associated with poorer sustained attention and irregular sleep. Findings suggest that irregular sleep is associated with less efficient attentional processing as reflected by the P3 component, and that longer target P3 latencies are associated with poorer sustained attention.

  14. Very weak solutions of wave equation for Landau Hamiltonian with irregular electromagnetic field

    Science.gov (United States)

    Ruzhansky, Michael; Tokmagambetov, Niyaz

    2017-04-01

    In this paper, we study the Cauchy problem for the Landau Hamiltonian wave equation, with time-dependent irregular (distributional) electromagnetic field and similarly irregular velocity. For such equations, we describe the notion of a `very weak solution' adapted to the type of solutions that exist for regular coefficients. The construction is based on considering Friedrichs-type mollifier of the coefficients and corresponding classical solutions, and their quantitative behaviour in the regularising parameter. We show that even for distributional coefficients, the Cauchy problem does have a very weak solution, and that this notion leads to classical or distributional-type solutions under conditions when such solutions also exist.

  15. Caring for the Unseen: Using Linking Social Capital to Improve Healthcare Access to Irregular Migrants in Spain

    OpenAIRE

    Mason, Deanna Marie

    2016-01-01

    Abstract Purpose To describe a novel strategy using linking social capital to provide healthcare access to irregular migrants with low literacy, low numeracy, and limited cultural assimilation in a European metropolitan area. Organizing Construct Public data show numerous shortcomings in meeting the healthcare needs of refugees and irregular migrants surging into Europe. Many irregular migrants living in European communities are unable to access information, care, or services due to lack of s...

  16. Wilson fermion doubling phenomenon on irregular lattice: the similarity and difference with the case of regular lattice

    CERN Document Server

    Vergeles, S N

    2015-01-01

    It is shown that the Wilson fermion doubling phenomenon on irregular lattices (simplicial complexes) does exist. This means that the irregular (not smooth) zero or soft modes exist. The statement is proved on 4 Dimensional lattice by means of the Atiyah-Singer index theorem, then it is extended easily into the cases $D<4$. But there is a fundamental difference between doubled quanta on regular and irregular lattices: in the latter case the propagator decreases exponentially. This means that the doubled quanta on irregular lattice are "bad" quasiparticles.

  17. Non-stationary random vibration analysis of a 3D train-bridge system using the probability density evolution method

    Science.gov (United States)

    Yu, Zhi-wu; Mao, Jian-feng; Guo, Feng-qi; Guo, Wei

    2016-03-01

    Rail irregularity is one of the main sources causing train-bridge random vibration. A new random vibration theory for the coupled train-bridge systems is proposed in this paper. First, number theory method (NTM) with 2N-dimensional vectors for the stochastic harmonic function (SHF) of rail irregularity power spectrum density was adopted to determine the representative points of spatial frequencies and phases to generate the random rail irregularity samples, and the non-stationary rail irregularity samples were modulated with the slowly varying function. Second, the probability density evolution method (PDEM) was employed to calculate the random dynamic vibration of the three-dimensional (3D) train-bridge system by a program compiled on the MATLAB® software platform. Eventually, the Newmark-β integration method and double edge difference method of total variation diminishing (TVD) format were adopted to obtain the mean value curve, the standard deviation curve and the time-history probability density information of responses. A case study was presented in which the ICE-3 train travels on a three-span simply-supported high-speed railway bridge with excitation of random rail irregularity. The results showed that compared to the Monte Carlo simulation, the PDEM has higher computational efficiency for the same accuracy, i.e., an improvement by 1-2 orders of magnitude. Additionally, the influences of rail irregularity and train speed on the random vibration of the coupled train-bridge system were discussed.

  18. From inverse problems in mathematical physiology to quantitative differential diagnoses.

    Directory of Open Access Journals (Sweden)

    Sven Zenker

    2007-11-01

    Full Text Available The improved capacity to acquire quantitative data in a clinical setting has generally failed to improve outcomes in acutely ill patients, suggesting a need for advances in computer-supported data interpretation and decision making. In particular, the application of mathematical models of experimentally elucidated physiological mechanisms could augment the interpretation of quantitative, patient-specific information and help to better target therapy. Yet, such models are typically complex and nonlinear, a reality that often precludes the identification of unique parameters and states of the model that best represent available data. Hypothesizing that this non-uniqueness can convey useful information, we implemented a simplified simulation of a common differential diagnostic process (hypotension in an acute care setting, using a combination of a mathematical model of the cardiovascular system, a stochastic measurement model, and Bayesian inference techniques to quantify parameter and state uncertainty. The output of this procedure is a probability density function on the space of model parameters and initial conditions for a particular patient, based on prior population information together with patient-specific clinical observations. We show that multimodal posterior probability density functions arise naturally, even when unimodal and uninformative priors are used. The peaks of these densities correspond to clinically relevant differential diagnoses and can, in the simplified simulation setting, be constrained to a single diagnosis by assimilating additional observations from dynamical interventions (e.g., fluid challenge. We conclude that the ill-posedness of the inverse problem in quantitative physiology is not merely a technical obstacle, but rather reflects clinical reality and, when addressed adequately in the solution process, provides a novel link between mathematically described physiological knowledge and the clinical concept of

  19. From inverse problems in mathematical physiology to quantitative differential diagnoses.

    Science.gov (United States)

    Zenker, Sven; Rubin, Jonathan; Clermont, Gilles

    2007-11-01

    The improved capacity to acquire quantitative data in a clinical setting has generally failed to improve outcomes in acutely ill patients, suggesting a need for advances in computer-supported data interpretation and decision making. In particular, the application of mathematical models of experimentally elucidated physiological mechanisms could augment the interpretation of quantitative, patient-specific information and help to better target therapy. Yet, such models are typically complex and nonlinear, a reality that often precludes the identification of unique parameters and states of the model that best represent available data. Hypothesizing that this non-uniqueness can convey useful information, we implemented a simplified simulation of a common differential diagnostic process (hypotension in an acute care setting), using a combination of a mathematical model of the cardiovascular system, a stochastic measurement model, and Bayesian inference techniques to quantify parameter and state uncertainty. The output of this procedure is a probability density function on the space of model parameters and initial conditions for a particular patient, based on prior population information together with patient-specific clinical observations. We show that multimodal posterior probability density functions arise naturally, even when unimodal and uninformative priors are used. The peaks of these densities correspond to clinically relevant differential diagnoses and can, in the simplified simulation setting, be constrained to a single diagnosis by assimilating additional observations from dynamical interventions (e.g., fluid challenge). We conclude that the ill-posedness of the inverse problem in quantitative physiology is not merely a technical obstacle, but rather reflects clinical reality and, when addressed adequately in the solution process, provides a novel link between mathematically described physiological knowledge and the clinical concept of differential diagnoses

  20. EXPERIMENTAL STUDY ON BED-LOAD SEDIMENT TRANSPORT IN IRREGULAR WAVE-CURRENT COEXISTENT FIELD

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to evaluate bed-load sediment transport in an irregular wave-current coexistent field, a series of experiments were completed in laboratory with an irregularly oscillating tray, which was specially designed to simulate the irregular wave-current coexistent field. Experimental results are presented on the initial motion of sediment and the rates of transport over flat horizontal bed. Testing conditions included three interaction angles, 0°, 45°, 90° and six kinds of grain sizes. Four kinds (0.2mm, 0.46mm, 0.85mm and 1.3mm) were used for the tests of initial motion, while the other two kinds (0.38mm and 1.1mm) for the tests of transport rate. Comparisons between experimental results of initial motion and modified Shields curve indicate that the Shields curve is still valid for the case of irregular wave-current coexistent field. Analysis of flow regime shows that initial conditions fall within smooth-turbulent transitional region. The results of transport rate show us that net sediment transport rate can be expressed approximately as the function of the maximum bottom shear stress and mean shear stress. A dimensionless formula is proposed on the basis of mechanism "Waves erode sediments, tides transport sediments".

  1. Digital Elevation Map Reconstruction for Port-based Dynamic Simulation of Contacts on Irregular Surfaces

    NARCIS (Netherlands)

    Wassink, Martin; Carloni, Raffaella; Poulakis, Pantelis; Stramigioli, Stefano

    2009-01-01

    This paper presents a method to utilize a port-based multibody contact model for simulating dynamic interaction between irregular surfaces. The existing compliant contact model requires an analytic parametrization of the surfaces involved in the interaction, the definition of a Gauss frame in each o

  2. Urano y sus dos satélites irregulares recientemente descubiertos

    Science.gov (United States)

    Parisi, M. G.; Brunini, A.

    Hasta hace poco tiempo, Urano era el único de los Planetas Gigantes que no poseía satélites irregulares. Esto lo diferenciaba del resto de los planetas Gigantes, al igual que la peculiar oblicuidad de su eje de spin. La gran inclinación de su eje de rotación se debe probablemente a una colisión que sufrió el planeta con otro embrión planetario al final del proceso de formación. Esta colisión habría desligado satélites exteriores preexistentes del planeta. Recientemente se han descubierto dos satélites irregulares de Urano, lo que introduce algunas nuevas cotas y condiciones en el escenario de la "Hipótesis de la Gran Colisión" . Los satélites irregulares de Urano tuvieron que ser capturados en una etapa posterior a la del escenario de la Gran Colisión, de no ser así, hubieran sido eyectados del sistema por el impulso impartido con ese gran impacto. En este trabajo, se discuten los posibles mecanismos de captura de los satélites irregulares y se presenta un nuevo posible mecanismo para dicha captura.

  3. ABO/RH DISTRIBUTION PATTERN AND PREVALENCE OF IRREGULAR ANTIBODIES IN HEALTHY BLOOD DONORS OF UTTARAKHAND

    Directory of Open Access Journals (Sweden)

    Brijesh Thakur

    2016-07-01

    Full Text Available BACKGROUND Blood group plays a vital role in transfusion safety, understanding genetics, inheritance pattern and disease susceptibility. This study is aimed to determine distribution pattern of ABO and Rh blood group, incidence and identification of irregular antibodies among blood donors of Uttarakhand. METHOD ABO/Rh blood grouping was performed by test tube agglutination method (both cell and serum grouping using antisera A, B and Rh from Tulip and Orthodiagnostics. Donors’ plasma were screened for irregular antibodies by indirect antiglobulin technique using Bio-Rad ID-Card “LISS/Coombs” and test cell reagents “ID-DiaCell” via gel centrifugation. RESULTS Out of total 4573 included blood donors, 88.2% were males. The maximum blood donors (77.6% were in 18-25 years of age group. The commonest ABO blood group present was B (36.1% followed by O (29.1%, A (24.8% and AB (10% in blood donors; while in Rhesus system, 95.0% donors were Rh-positive and 5.0% donors were Rh negative. Screening of donors’ plasma did not reveal any detectable irregular antibody. CONCLUSION The study has a significant implication in suggesting the distribution pattern of ABO/Rh blood group typing in the region, but routine irregular antibody screening in healthy blood donors may not be fruitful in this region keeping cost effectiveness and absence of previous sensitization in mind

  4. A Novel Short-Range Prediction Model for Railway Track Irregularity

    Directory of Open Access Journals (Sweden)

    Peng Xu

    2012-01-01

    Full Text Available In recent years, with axle loads, train loads, transport volume, and travel speed constantly increasing and railway network steadily lengthening, shortcomings of current maintenance strategies are getting to be noticed from an economical and safety perspective. To overcome the shortcomings, permanent-of-way departments throughout the world have given a considerable attention to an ideal maintenance strategy which is to carry out appropriate maintenances just in time on track locations really requiring maintenance. This strategy is simplified as the condition-based maintenance (CBM which has attracted attentions of engineers of many industries in the recent 70 years. To implement CBM for track irregularity, there are many issues which need to be addressed. One of them focuses on predicting track irregularity of each day in a future short period. In this paper, based on track irregularity evolution characteristics, a Short-Range Prediction Model was developed to this aim and is abbreviated to TI-SRPM. Performance analysis results for TI-SRPM illustrate that track irregularity amplitude predictions on sampling points by TI-SRPM are very close to their measurements by Track Geometry Car.

  5. Modelling the Cost Performance of a Given Logistics Network Operating Under Regular and Irregular Conditions

    NARCIS (Netherlands)

    Janic, M.

    2009-01-01

    This paper develops an analytical model for the assessment of the cost performance of a given logistics network operating under regular and irregular (disruptive) conditions. In addition, the paper aims to carry out a sensitivity analysis of this cost with respect to changes of the most influencing

  6. Parallel ocean flow computations on a regular and on an irregular grid

    NARCIS (Netherlands)

    Gijzen, M.B. van

    2001-01-01

    Ocean flow problems can be discretized and solved on a regular grid, by taking l and points into account in the computations, or on an irregular grid. In the latter approach, the number of unknowns is less than for the regular grid. The data structures are completely different for the two approaches

  7. VARIABLE-STARS IN THE IRREGULAR GALAXY NGC-2366 (DDO-42)

    NARCIS (Netherlands)

    TOLSTOY, E; SAHA, A; HOESSEL, JG; MCQUADE, K

    1995-01-01

    Observations of the resolved stars in the Irregular galaxy NGC 2366, obtained over the ten year period from March 1984 to March 1994, are presented. Thirty separate epochs were used to search for variable stars, and a total of 13 were found, of which 6 have characteristic Cepheid light curves and co

  8. Sinking of irregular shape blocks into marine seabed under wave-induced liquefaction

    DEFF Research Database (Denmark)

    Kirca, Özgür

    2013-01-01

    The sinking of initially buried irregular blocks into the seabed under wave-induced liquefaction was investigated by experimental methods. Pore-water pressure in the soil, water surface elevation time series and block displacements were measured. Results indicated that initiation of sinking...

  9. Acquiring Regular and Irregular Past Tense Morphemes in English and French: Evidence from Bilingual Children

    Science.gov (United States)

    Nicoladis, Elena; Paradis, Johanne

    2012-01-01

    The aim of this study was to use crosslinguistic data from French-English bilinguals to test two models of past tense acquisition: (a) single route (all past tense forms rely on morphophonological schemas) and (b) dual route (irregular forms are learned as words, regulars through rules). These models make similar predictions about English…

  10. Gait Characteristics Associated with Trip-Induced Falls on Level and Sloped Irregular Surfaces

    Directory of Open Access Journals (Sweden)

    Andrew Merryweather

    2011-11-01

    Full Text Available Same level falls continue to contribute to an alarming number of slip/trip/fall injuries in the mining workforce. The objective of this study was to investigate how walking on different surface types and transverse slopes influences gait parameters that may be associated with a trip event. Gait analysis was performed for ten subjects on two orientations (level and sloped on smooth, hard surface (control and irregular (gravel, larger rocks surfaces. Walking on irregular surfaces significantly increased toe clearance compared to walking on the smooth surface. There was a significant (p < 0.05 decrease in cadence (steps/min, stride length (m, and speed (m/s from control to gravel to larger rocks. Significant changes in external rotation and increased knee flexion while walking on irregular surfaces were observed. Toe and heel clearance requirements increased on irregular surfaces, which may provide an explanation for trip-induced falls; however, the gait alterations observed in the experienced workers used as subjects would likely improve stability and recovery from a trip.

  11. Sharp mandibular bone irregularities after lower third molar extraction: Incidence, clinical features and risk factors

    Science.gov (United States)

    Alves-Pereira, Daniela; Valmaseda-Castellón, Eduard; Laskin, Daniel M.; Berini-Aytés, Leonardo; Gay-Escoda, Cosme

    2013-01-01

    Objectives: The purpose of this study was to determine the incidence and clinical symptoms associated with sharp mandibular bone irregularities (SMBI) after lower third molar extraction and to identify possible risk factors for this complication. Study Design: A mixed study design was used. A retrospective cohort study of 1432 lower third molar extractions was done to determine the incidence of SMBI and a retrospective case-control study was done to determine potential demographic and etiologic factors by comparing those patients with postoperative SMBI with controls. Results: Twelve SMBI were found (0.84%). Age was the most important risk factor for this complication. The operated side and the presence of an associated radiolucent image were also significantly related to the development of mandibular bone irregularities. The depth of impaction of the tooth might also be an important factor since erupted or nearly erupted third molars were more frequent in the SMBI group. Conclusions: SMBI are a rare postoperative complication after lower third molar removal. Older patients having left side lower third molars removed are more likely to develop this problem. The treatment should be the removal of the irregularity when the patient is symptomatic. Key words:Third molar, postoperative complication, bone irregularities, age. PMID:23524429

  12. Spelling Pronunciation and Visual Preview Both Facilitate Learning to Spell Irregular Words

    Science.gov (United States)

    Hilte, Maartje; Reitsma, Pieter

    2006-01-01

    Spelling pronunciations are hypothesized to be helpful in building up relatively stable phonologically underpinned orthographic representations, particularly for learning words with irregular phoneme-grapheme correspondences. In a four-week computer-based training, the efficacy of spelling pronunciations and previewing the spelling patterns on…

  13. Menstrual Irregularities and Related Plasma Hormone Levels in Multiple Sclerosis Patients Treated with Beta Interferone

    Directory of Open Access Journals (Sweden)

    Ehya Garshasbi

    2010-02-01

    Full Text Available Multiple sclerosis is a chronic inflammatory disease of central nervous system.Women are more susceptible to this disease. One of the obvious clinical complaints in women with multiple sclerosis specially treated with Beta Interferones is menstrual cycle irregularity. The aim of this study was to determine the prevalence of menstrual irregularities and probable changes in blood levels of related hormones (FSH, LH, PRL, TSH, T4, T3 in 58 females with definite MS treated with beta interferones versus 58 healthy women. In comparison to the control group, the patients had higher prevalence of irregular menstruation (P=0.001, oligomenorrhea (p=0.03, abnormal amount of menstrual blood flow (P=0.001, abnormal duration of menstrual flow (P=0.01 and missed period (P=0.04. Mean LH level in patients group was higher than control group (P=0.04.Hyperprolactinemia (>25.5ng/ml was more prevalent in patients group .There were not a significant difference in plasma levels of FSH and thyroid hormones between two groups. There were some relations between the type of Beta interferones and the subtype of menstrual irregularities in the patients. In conclusion, the results of this study emphasized the high rate of menstrual problem and changes of related plasma hormone levels in MS patients.

  14. Analysis of achievable capacity in irregularly-placed high performance mesh nodes

    CSIR Research Space (South Africa)

    Olwal, TO

    2012-09-01

    Full Text Available challenge. This paper derives the achievable capacity limit of such HPNs’ placements. The analytical results show that the network capacity increases with the irregularity of HPNs placements, the number of antennas as well as the multiplicity of radios per...

  15. Large Scale Model Test Investigation on Wave Run-Up in Irregular Waves at Slender Piles

    DEFF Research Database (Denmark)

    Ramirez, Jorge Robert Rodriguez; Frigaard, Peter; Andersen, Thomas Lykke

    2013-01-01

    from high speed video recordings. Based on the measured run-up heights different types of prediction formulae for run-up in irregular waves were evaluated. In conclusion scale effects on run-up levels seems small except for differences in spray. However, run-up of individual waves is difficult...

  16. Health care for irregular migrants: pragmatism across Europe. A qualitative study.

    NARCIS (Netherlands)

    Dauvrin, M.; Lorant, V.; Sandhu, S.; Devillé, W.; Dia, H.; Dias, S.; Gaddini, A.; Ioannidis, E.; Jensen, N.K.; Kluge, U.; Mertaniemi, R.; Puigpinósi Riera, R.; Sarvary, A.; Straßmayr, C.; Stankunas, M.; Soares, J.J.F.; Welbel, M.; Priebe, S.

    2012-01-01

    Background: Health services in Europe face the challenge of delivering care to a heterogeneous group of irregular migrants (IM). There is little empirical evidence on how health professionals cope with this challenge. This study explores the experiences of health professionals providing care to IM i

  17. COMPARISON OF SCOURS IN FRONT OF VERTICAL BREAKWATERS DUE TO REGULAR AND IRREGULAR WAVES

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper the scours of sand bed due to regular and irregular waves in front of vertical breakwaters, such as scouring patterns, scouring mechanisms, etc., are investigated. Thereby, the scours under the action of the two kinds of waves are compared connected.

  18. URANS simulations of ship motion responses in long-crest irregular waves

    Institute of Scientific and Technical Information of China (English)

    沈志荣; 叶海轩; 万德成

    2014-01-01

    In this paper, numerical prediction of ship motion responses in long-crest irregular waves by the URANS-VOF method is presented. A white noise spectrum is applied to generate the incoming waves to evaluate the motion responses. The procedure can replace a decade of simulations in regular wave with one single run to obtain a complete curve of linear motion response, conside-rably reducing computation time. A correction procedure is employed to adjust the wave generation signal based on the wave spe-ctrum and achieves fairly better results in the wave tank. Three ship models with five wave conditions are introduced to validate the method. The computations in this paper are completed by using the solver naoe-FOAM-SJTU, a solver developed for ship and ocean engineering based on the open source code OpenFOAM. The computational motion responses by the irregular wave procedure are compared with the results by regular wave, experiments and strip theory. Transfer functions by irregular wave closely agree with the data obtained in the regular waves, showing negligible difference. The comparison between computational results and experiments also show good agreements. The results better predicted by CFD method than strip theories indicate that this method can compensate for the inaccuracy of the strip theories. The results confirm that the irregular wave procedure is a promising method for the accurate prediction of motion responses with less accuracy loss and higher efficiency compared with the regular wave procedure.

  19. Molecular analyses of Pythium irregulare isolates from grapevines in South Africa suggest a single variable species

    Science.gov (United States)

    The Pythium irregulare species complex is the most common and widespread Pythium spp. associated with grapevines in South Africa. This species complex can be subdivided into several morphological and phylogenetic species that are all highly similar at the sequence level. The complex includes P. re...

  20. Time-accurate AB-simulations of irregular coastal waves above bathymetry

    NARCIS (Netherlands)

    Groesen, van E. (Brenny); Andonowati,; Lee, Joseph Hun-Wei; Ng, Chiu-On

    2011-01-01

    In this contribution the performance is shown of a hybrid spectral-spatial implementation of the AB model for uni-directional waves above varying bottom. For irregular waves of JONSWAP-type, with peak periods of 9 and 12[s], significant wave height of 3[m], running from 30 to 15[m] depth over a 1:20