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Sample records for abdelsalam sumi helal

  1. Polarization Measurements on SUMI's TVLS Gratings

    NASA Technical Reports Server (NTRS)

    Kobayashi, K.; West, E. A.; Davis, J. M.; Gary, G. A.

    2007-01-01

    We present measurements of toroidal variable-line-space (TVLS) gratings for the Solar Ultraviolet Magnetograph Investigation (SUMI), currently being developed at the National Space Science and Technology Center (NSSTC). SUMI is a spectro-polarimeter designed to measure magnetic fields in the solar chromosphere by observing two UV emission lines sensitive to magnetic fields, the CIY line at 155nm and the MgII line at 280nm. The instrument uses a pair of TVLS gratings, to observe both linear polarizations simultaneously. Efficiency measurements were done on bare aluminum gratings and aluminum/MgF2 coated gratings, at both linear polarizations.

  2. Polarization measurements in the Vacuum Ultraviolet using SUMI

    NASA Technical Reports Server (NTRS)

    West, E. A.

    2005-01-01

    This paper will describe the VUV polarization testing of the NSSTC Solar Ultraviolet Magnetograph (SUMI) optics. SUMI is being developed for a sounding rocket payload to prove the feasibility of making magnetic field measurements in the transition region. This paper will cover the polarization testing of the SUMI optics and the instrumental polarization of the VUV test facility.

  3. SUMI - The Solar Ultraviolet Magnetograph Investigation

    NASA Technical Reports Server (NTRS)

    Porter, J. G.; West, E. A.; Davis, J. M.; Gary, G. A.; Noble, M. W.; Thomas, R. J.; Rabin, D. M.; Uitenbroek, H.

    2003-01-01

    Solar physics has been successful in characterizing the full vector magnetic field in the photosphere, where the ratio of gas pressure to magnetic pressure (Beta) is >1. However, at higher levels in the atmosphere, where Beta <<1 and flares and CMEs are believed to be triggered, observations are difficult, severely limiting the understanding of these processes. In response to this situation, we are developing SUMI (the Solar Ultraviolet Magnetograph Investigation) a unique instrument designed to measure the circular and linear polarization of upper chromospheric Mg II lines (280 nm) and circular polarization of transition region C IV lines (155 nm). To date the telescope mirrors have been built, tested and coated with dielectric stacks designed to reflect only the wavelengths of interest. We have also developed a unique UV polarimeter and completed the design of a high-resolution spectrograph that uses dual toroidal varied- line-space (TVLS) gratings. Incorporating measurements of those components developed so far, the revised estimate of the system throughput exceeds our original estimate by more than an order of magnitude. A sounding rocket flight is anticipated in 2006. Our objectives and progress are detailed in this presentation.

  4. Solar Ultraviolet Magnetograph Investigation (SUMI) Component Responses to Payload Vibration Testing

    NASA Technical Reports Server (NTRS)

    Hunt, Ronald A.

    2011-01-01

    Vibration testing of SUMI was performed at both the experiment and payload levels. No accelerometers were installed inside the experiment during testing, but it is certain that component responses were very high. The environments experienced by optical and electronic components in these tests is an area of ongoing concern. The analysis supporting this presentation included a detailed finite element model of the SUMI experiment section, the dynamic response of which, correlated well with accelerometer measurements from the testing of the experimental section at Marshall Space Flight Center. The relatively short timeframe available to complete the task and the limited design information available was a limitation on the level of detail possible for the non-experiment portion of the model. However, since the locations of interest are buried in the experimental section of the model, the calculated responses should be enlightening both for the development of test criteria and for guidance in design.

  5. The Relationship between Personality Type and Software Usability Using the Myers-Briggs Type Indicator (MBTI) and the Software Usability Measurement Inventory (SUMI)

    ERIC Educational Resources Information Center

    Lindsey, William H.

    2011-01-01

    The study attempted to determine if there is a relationship between user's psychological personality types, measured by the Myers Briggs Type Indicator[R] (MBTI[R]) and distinct measures of usability measured by the Software Usability Measurement Inventory (SUMI). The study was expected to provide an answer to the following basic research…

  6. Obtaining Stokes Parameters from the SUMI Experiment

    NASA Technical Reports Server (NTRS)

    Fayock, Brian; Winebarger, Amy; Cirtain, Jonathan; Kobayashi, Ken; West, Ed

    2014-01-01

    A sounding rocket experiment designed at the Marshall Space Flight Center, named the Solar Ultraviolet Magnetograph Investigation, had its second launch in July of 2012 to test the feasibility of measuring polarization signals of the ionized magnesium resonance doublet near 280 nm, originating from the transition region. The rocket housed a telescope at the front end and an imaging system at the rear end. Placed at the focal point of the self-filtering telescope, a wave plate rotated through 12 predefined angular orientations to restrict the measurements to specific combinations of circular and linear polarization. Coupled with a double Wollaston analyzer, the linearly polarized ordinary and extraordinary beams were measured for the 12 combinations, each containing different fractions of the Stokes parameters (I, Q, U, V). A thorough analysis of the data has allowed us to come to several conclusions regarding the design of the experiment. 1) We are confident that polarization can be measured. A sunspot region was determined to exhibit similar results over multiple pixels. 2) Measurements are limited by resolution, i.e. regions smaller than the angular resolution per pixel cannot be resolved with any certainty. 3) Temporal evolution of magnetic features must be considered in future experimental designs. Measurements need to be taken in repeated cycles as opposed to a single cycle over the duration of the experiment. In our presentation, we will provide a summary of the observations along with the methods of our analysis, including the limitations that we've encountered.

  7. Innovation for Information: International Contributions to Librarianship. Festschrift in Honour of Dr. Ahmed H. Helal. Publication 16.

    ERIC Educational Resources Information Center

    Weiss, Joachim W., Ed.

    This publication contains the following essays: (1) "Das Bibliothekssystem der Ruhr-Universitat Bochum: hochschul-und stazungsrechtliche Grundlagen" (Bernhard Adams); (2) "On Appropriate Librarianship: The Genesis of the Library of Today, and Its Possible Exodus Tomorrow" (Maurice B. Line); (3) "The Challenge to Library and Information…

  8. [Achromatic watercolor effect: about requirement of formation of sumi painting effect].

    PubMed

    Takashima, Midori

    2008-10-01

    The watercolor effect (Pinna, Brelstaff, & Spillmann, 2001) is a new color spreading phenomenon. Pinna et al. (2001) proposed that the watercolor effect is a new Gestalt factor because it determines figure-ground organization more strongly than classical Gestalt factors. We used achroriatic watercolor patterns and varied the lightness of the background and two border lines to study the relationship between the color spreading effect and figure-ground organization. The results demonstrated (a)a bidirectional color spreading phenomenon when the background lightness was between the two border-lines' lightness, and that (b) some patterns elicit only a color spreading effect without organization of figure-ground, while others elicit only figure-ground organization without a color spreading effect. PMID:19069121

  9. EXTENT AND KINEMATICS OF ASWA SHEAR ZONE IN UGANDA AND SOUTH SUDAN USING AIRBORNE GEOPHYSICAL AND REMOTE SENSING DATA. A. Katumwehe. 1, E. A. Atekwana. 1, M.G. Abdelsalam.1 1Oklahoma State University, Boone Pickens School of Geology, Stillwater, USA

    NASA Astrophysics Data System (ADS)

    katumwehe, A. B.; Atekwana, E. A.; Abdel Salam, M. G.

    2012-12-01

    The Aswa Shear zone (ASZ) is a fundamental Precambrian lithospheric structure playing an important role in the evolution of the Mesozoic South Sudan rifts, the propagation of the Cenozoic East African Rift System (EARS), the eruption of EARS shield volcanoes (Mt Kilimanjaro and Mt Elgon), re-organization of drainage systems (the White Nile), and the distribution of recent seismicity in South Sudan. Traces of the shear zone have been mapped extending in central and east Africa in a NW-SE direction from South Sudan in the northwest through Uganda and Tanzania to the southeast and possibly into Madagascar. Gondwana reconstructions suggest that the ASZ continues further southeast into south India. Nonetheless, the kinematics and extent of the ASZ have not been fully understood because of limited exposure. In areas where it is exposed the shear zone is expressed by narrow dominantly NW-trending outcrops. We use recently acquired high resolution airborne magnetic and radiometric data over Uganda integrated with 90 m spatial resolution Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) and 30 m spatial resolution Landsat Thematic Mapper (TM) spectral data to elucidate the kinematics and ascertain the significance of the ASZ in the development of the EARS and the tectonic architecture of east and central Africa. Vertical derivative, Euler deconvolution and analytical signal filters were applied to the total field magnetic data to image the shallow subsurface structures associated with the ASZ while upward continuation (5000 m) was applied to assess the ASZ depth continuity. We also used radiometric data to create ternary images while SRTM and Landsat TM data were used to map the surface expression of the shear zone. The geophysical data from Uganda suggest that the ASZ is characterised by a 50-60 km wide corridor of ductile deformation associated with NW-trending strike-slip shearing. It is dominated by three, equally-spaced and discrete sinistral strike-slip shear zones bounding wider belts dominated by splays of secondary shear zones and shear-related folds. These folds become tighter close to discrete shear zones and their axial traces become sub-parallel to the shear zones themselves. A similar pattern is observed on the surface in South Sudan in the SRTM DEM and the Landsat TM images. The evolution of these folds is explained in terms of secondary constructional strain developed in association and nearly perpendicular to the NW-trend of the sinistral strike-slip shearling. There is a remarkable resemblance between the magnetic fabric of the ASZ and that of the Najd fault system; a major sinistral strike-slip shear system in the Arabian-Nubian Shield suggesting that the shear zones may have evolved through similar Neopreterozoic Pan-African tectonic events, possibly associated with the collision between East and West Gondwana. The EARS bifurcates into the Eastern and Western branches -south of the ASZ while the Western branch terminates at the ASZ near the border between Uganda and South Sudan. This implies that the ASZ together with the Tanzanian craton played an important role in strain localization and prorogation during the evolution of the EARS.

  10. Polarization Measurements in the Vacuum Ultraviolet

    NASA Technical Reports Server (NTRS)

    West, E. A.; Kobayashi, K.; Noble, M.

    2005-01-01

    This paper will describe the VUV polarization testing of the NSSTC Solar Ultraviolet Magnetograph (SUMI) optics. SUMI is being developed for a sounding rocket payload to prove the feasibility of making magnetic field measurements in the transition region. This paper will cover the polarization properties of the VUV calibration polarizers, the instrumental polarization of the VUV chamber, SUMI's toroidal varied-line-space gratings and the SUMI polarimeter.

  11. MgII Observations Using the MSFC Solar Ultraviolet Magnetograph

    NASA Technical Reports Server (NTRS)

    West, Edward; Cirtain, Jonathan; Kobayashi, Ken; Davis, John; Gary, Allen; Adams, Mitzi

    2011-01-01

    This paper will describe the scientific goals of our sounding rocket program, the Solar Ultraviolet Magnetograph Investigation (SUMI). This paper will present a brief description of the optics that were developed to meet SUMI's scientific goals, discuss the spectral, spatial and polarization characteristics of SUMI s optics, describe SUMI's flight which was launched 7/30/2010, and discuss what we have learned from that flight.

  12. Polarization measurements in the vacuum ultraviolet

    NASA Astrophysics Data System (ADS)

    Kobayashi, K.; West, E. A.; Noble, M.

    2005-08-01

    This paper will describe the Vacuum Ultraviolet (VUV) polarization testing of the Solar Ultraviolet Magnetograph (SUMI) optics. SUMI is being develop for a sounding rocket payload to prove the feasibility of making magnetic field measurements in the transition region. This paper will cover the polarization properties of the VUV calibration polarizers, the instrumental polarization of the VUV chamber, SUMI's toroidal varied-line-space gratings and the SUMI polarimeter.

  13. Spectral Calibration of the MSFC Solar Ultraviolet Magnetograph

    NASA Technical Reports Server (NTRS)

    West, Edward; Kobayashi, Ken; Cirtain, Jonathan; Gary, Allen; Davis, John; Reader, Joseph

    2009-01-01

    This paper describes the scientific goals of a sounding rocket program called the Solar Ultraviolet Magnetograph Investigation (SUMI), presents a brief description of the optics that were developed to meet those goals and discusses the spectral, spatial and polarization characteristics of SUMI's Toroidal Variable-Line-Space (TVLS) gratings; which are critical to SUMI's measurements of the magnetic field in the Sun's transition region.

  14. 75 FR 53271 - Assessment of Fees for Dairy Import Licenses for the 2011 Tariff-Rate Import Quota Year

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-31

    ...; ] DEPARTMENT OF AGRICULTURE Foreign Agricultural Service Assessment of Fees for Dairy Import Licenses for the... importation of certain dairy articles, which are subject to tariff-rate quotas set forth in the Harmonized... CONTACT: Abdelsalam El-Farra, Dairy Import Licensing Program, Import Policies and Export...

  15. 77 FR 51751 - Assessment of Fees for Dairy Import Licenses for the 2013 Tariff-Rate Import Quota Year

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-27

    ... Foreign Agricultural Service Assessment of Fees for Dairy Import Licenses for the 2013 Tariff- Rate Import... person or firm by the Department of Agriculture authorizing the importation of certain dairy articles... States. DATES: August 27, 2012. FOR FURTHER INFORMATION CONTACT: Abdelsalam El-Farra, Dairy...

  16. Spectral Calibration of the MSFC Solar Ultraviolet Magnetograph

    NASA Technical Reports Server (NTRS)

    West, Edward A.

    2009-01-01

    This paper will describe the scientific goals of a sounding rocket program called the Solar Ultraviolet Magnetograph Investigation (SUMI), present a brief description of the optics that were developed to meet those goals and discuss the spectral, spatial and polarization characteristics of SUMI's Toroidal Variable-Line-Space (TVLS) gratings which are critical to SUMI's measurements of the magnetic field in the Sun's transition region.

  17. Making Ultraviolet Spectro-Polarimetry Polarization Measurements with the MSFC Solar Ultraviolet Magnetograph Sounding Rocket

    NASA Technical Reports Server (NTRS)

    West, Edward; Cirtain, Jonathan; Kobayashi, Ken; Davis, John; Gary, Allen

    2011-01-01

    This paper will describe the Marshall Space Flight Center's Solar Ultraviolet Magnetograph Investigation (SUMI) sounding rocket program. This paper will concentrate on SUMI's VUV optics, and discuss their spectral, spatial and polarization characteristics. While SUMI's first flight (7/30/2010) met all of its mission success criteria, there are several areas that will be improved for its second and third flights. This paper will emphasize the MgII linear polarization measurements and describe the changes that will be made to the sounding rocket and how those changes will improve the scientific data acquired by SUMI.

  18. Optical Characteristics of the Marshall Space Flight Center Solar Ultraviolet Magnetograph

    NASA Technical Reports Server (NTRS)

    West, E. A.; Porter, J. G.; Davis, J. M.; Gary, G. A.; Adams, M.; Smith, S.; Hraba, J. F.

    2001-01-01

    This paper will describe the scientific objectives of the Marshall Space Flight Center (MSFC) Solar Ultraviolet Magnetograph Investigation (SUMI) and the optical components that have been developed to meet those objectives. In order to test the scientific feasibility of measuring magnetic fields in the UV, a sounding rocket payload is being developed. This paper will discuss: (1) the scientific measurements that will be made by the SUMI sounding rocket program, (2) how the optics have been optimized for simultaneous measurements of two magnetic lines CIV (1550 Angstroms) and MgII (2800 Angstroms), and (3) the optical, reflectance, transmission and polarization measurements that have been made on the SUMI telescope mirror and polarimeter.

  19. The Marshall Space Flight Center Solar Ultraviolet Magnetograph

    NASA Technical Reports Server (NTRS)

    West, E. A.; Porter, J. G.; Davis, J. M.; Gary, G. A.; Noble, M. W.; Lewis, M.; Thomas, Roger J.

    2004-01-01

    This paper will describe the objectives of the Marshall Space Flight Center (MSFC) Solar Ultraviolet Magnetograph Investigation (SUMI) and the optical components that have been developed to meet those objectives. In order to test the scientific feasibility of measuring magnetic fields in the UV, a sounding rocket payload is being developed. This paper will discuss: (1) the scientific measurements that will be made by the SUMI sounding rocket program, (2) how the optics have been optimized for simultaneous measurements of two magnetic lines CIV (1550Angstroms) and MgII (2800Angstroms), and (3) the optical, reflectance, transmission and polarization measurements that have been made on the SUMI telescope mirrors and polarimeter.

  20. The Marshall Space Flight Center Solar Utraviolet Magnetograph

    NASA Technical Reports Server (NTRS)

    West, E. A.; Porter, J. G.; Davis, J. M.; Gary, G. A.; Noble, M.

    2004-01-01

    This paper will describe the objectives of the Marshall Space Flight Center (MSFC) Solar Ultraviolet Magnetograph Investigation (SUMI) and the optical components that have been developed to meet those objectives. In order to test the scientific feasibility of measuring magnetic fields in the W, a sounding rocket payload is being developed. This paper will discuss: (1) the scientific measurements that will be made by the SUMI sounding rocket program, (2) how the optics have been optimized for simultaneous measurements of two magnetic lines CIV (1550 Angstroms) and MgII (2800 Angstroms), and (3) the optical, reflectance, transmission and polarization measurements that have been made on the SUMI telescope mirrors and polarimeter.

  1. MgII Linear Polarization Measurements Using the MSFC Solar Ultraviolet Magnetograph Sounding Rocket

    NASA Technical Reports Server (NTRS)

    West, Edward; Cirtain, Jonathan; Kobayashi, Ken; Davis, John; Gary, Allen

    2011-01-01

    This paper will describe the Marshall Space Flight Center's Solar Ultraviolet Magnetograph Investigation (SUMI) sounding rocket program, with emphasis on the polarization characteristics of the VUV optics and their spectral, spatial and polarization resolution. SUMI's first flight (7/30/2010) met all of its mission success criteria and this paper will describe the data that was acquired with emphasis on the MgII linear polarization measurements.

  2. MgII Linear Polarization Measurements Using the MSFC Solar Ultraviolet Magnetograph

    NASA Technical Reports Server (NTRS)

    West, Edward; Cirtain, Jonathan; Kobayahsi, Ken; Davis, John; Gary, Allen; Adams, Mitzi

    2011-01-01

    This paper will describe the Marshall Space Flight Center's Solar Ultraviolet Magnetograph (SUMI) sounding rocket program, with emphasis on the polarization characteristics of the VUV optics and their spectral, spatial and polarization resolution. SUMI's first flight (7/30/2010) met all of its mission success criteria and this paper will describe the data that was acquired with emphasis on the MgII linear polarization measurements.

  3. Toroidal Variable-Line-Space Gratings: The Good, the Bad and The Ugly

    NASA Technical Reports Server (NTRS)

    West, Edward A.; Kobayashi, Ken; Cirtain, Jonathan; Gary, Allen; Davis, John; Reader, Joseph

    2009-01-01

    Toroidal variable-line-space (VLS) gratings are an important factor in the design of an efficient VUV solar telescope that will measure the CIV (155nm) and MgII (280nm) emissions lines in the Sun's transition region. In 1983 Kita and Harada described spherical VLS gratings but the technology to commercially fabricate these devices is a recent development, especially for toroidal surfaces. This paper will describe why this technology is important in the development of the Solar Ultraviolet Magnetograph Investigation (SUMI) sounding rocket program (the good), the delays due to the conversion between the TVLS grating design and the optical fabrication (the bad), and finally the optical testing, alignment and tolerancing of the gratings (the ugly). The Solar Ultraviolet Magnetograph Investigation, SUMI, has been reported in several papers since this program began in 2000. The emphasis of this paper is to describe SUMI's Toroidal Variable-Line-Space (TVLS) gratings. These gratings help SUMI meet its scientific goals which require both high spectral resolution and high optical efficiency for magnetic field measurements in the vacuum ultraviolet wavelength band of the solar spectrum (the good). Unfortunately, the technology readiness level of these gratings has made their implementation difficult, especially for a sounding rocket payload (the bad). Therefore, this paper emphasizes the problems and solutions that were developed to use these gratings in SUMI (the ugly). Section 2 contains a short review of the scientific goals of SUMI and why this mission is important in the understanding of the 3D structure of the magnetic field on the Sun. The flight hardware that makes up the SUMI payload is described in Section 3 with emphasis on those components that affect the TVLS gratings. Section 4 emphasizes the alignment, testing and optical modeling that were developed to optimize the performance of these gratings.

  4. The Solar Ultraviolet Magnetograph Investigation Sounding Rocket Program

    NASA Technical Reports Server (NTRS)

    West, E. A.; Kobayashi, K.; Davis, J. M.; Gary, G. A.

    2007-01-01

    This paper will describe the objectives of the Marshall Space Flight Center (MSFC) Solar Ultraviolet Magnetograph Investigation (SUMI) and the unique optical components that have been developed to meet those objectives. A sounding rocket payload has been developed to test the feasibility of magnetic field measurements in the Sun's transition region. The optics have been optimized for simultaneous measurements of two magnetic sensitive lines formed in the transition region (CIV at 1550 A and MgII at 2800 A). This paper will concentrate on the polarization properties SUMI's toroidal varied-line-space (TVLS) gratings and its system level testing as we prepare to launch in the Summer of 2008.

  5. Approach to Dynamic Assembling of Individualized Learning Paths

    ERIC Educational Resources Information Center

    Lubchak, Vladimir; Kupenko, Olena; Kuzikov, Borys

    2012-01-01

    E-learning students are generally heterogeneous and have different capabilities knowledge base and needs. The aim of the Sumy State University (SSU) e-learning system project is to cater to these individual needs by assembling individual learning path. This paper shows current situation with e-learning in Ukraine, state-of-art of development of…

  6. Flow and Heat Transfer Characteristics in a Closed-Type Two-Phase Loop Thermosyphon

    NASA Astrophysics Data System (ADS)

    Imura, Hideaki; Saito, Yuji; Fujimoto, Hiromitsu

    A closed-loop two-phase thermosyphon can transport a large amount of thermal energy with small temperature differences without any external power supply. A fundamental investigation of flow and heat transfer characteristics was performed experimentally and theoretically using water, ethanol and R113 as the working liquids. Heat transfer coefficients in an evaporator and a condenser, and circulation flow rates were measured experimentally. The effects of liquid fill charge, rotation angle, pressure in the loop and heat flux on the heat transfer coefficients were examined. The heat transfer coefficients in the evaporator and the condenser were correlated by the expressions for pool boiling and film condensation respectively. As a result, the heat transfer coefficients in the evaporator were correlated by the Stephan-Abdelsalam equations within a±40% error. Theoretically, the circulation flow rate was predicted by calculating pressure, temperature, quality and void fraction along the loop. And, the comparison between the calculated and experimental results was made.

  7. Overview of the Solar Ultraviolet Magnetograph Investigation

    NASA Technical Reports Server (NTRS)

    West, Edward A.; Porter, Jason G.; Davis, John M.; Gary, G. A.; Spann, James F., Jr.

    2000-01-01

    Traditional magnetographs measure the solar magnetic field at the visible "surface" of the Sun, the photosphere. The Solar Ultraviolet Magnetograph Investigation (SUMI) is a design study for an instrument to measure the solar magnetic field higher in the atmosphere, in the upper chromosphere and in the transition region at the base of the corona. The magnetic pressure at these levels is much stronger than the gas pressure (in contrast to the situation at the photosphere), and so the field is much more dynamic. Observations in this region will significantly improve our understanding of the physical processes driving flares and heating in the Sun's upper atmosphere. The instrument will incorporate new technologies to achieve the polarization efficiencies required to isolate the magnetic lines (Civ at 155nm and MgII at 280nm) to be observed in the UV. We describe the scientific goals, the SUMI baseline design and the optical components that are being developed for a sounding rocket program.

  8. The Solar Ultraviolet Magnetograph Investigation: Polarization Properties

    NASA Technical Reports Server (NTRS)

    West, E. A.; Porter, J. G.; Davis, J. M.; Gary, G. A.; Kobayashi, K.; Noble, M.

    2005-01-01

    This paper will describe the objectives of the Marshall Space Flight Center (MSFC) Solar Ultraviolet Magnetograph Investigation (SUMI) and the optical components that have been developed to meet those objectives. A sounding rocket payload is being developed to test the feasibility of magnetic field measurements in the Sun s transition region. This paper will review the scientific measurements that will be made by the SUMI sounding rocket program, and the optics have been optimized for simultaneous measurements of two magnetic lines formed in the transition region (CIV at 1550 A and MgII at 2800 A). Finally, this paper will concentrate on the polarization properties of the SUM1 polarimeter and toroidal varied-line-space gratings.

  9. Waring's problem with the Ramanujan \\tau-function

    NASA Astrophysics Data System (ADS)

    Garaev, M. Z.; Garcia, V. C.; Konyagin, S. V.

    2008-02-01

    We prove that for every integer N the Diophantine equation \\sum_{i=1}^{74000}\\tau(n_i)=N, where \\tau(n) is the Ramanujan \\tau-function, has a solution in positive integers n_1, n_2,\\dots, n_{74000} satisfying the condition \\max_{1\\le i\\le 74000}n_i\\,{\\ll}\\vert N\\vert^{2/11}+1. We also consider similar questions in residue fields modulo a large prime p.

  10. Boiling heat transfer of refrigerant R-113 in a small-diameter, horizontal tube

    SciTech Connect

    Wambsganss, M.W.; Jendrzejczyk, J.A.; Tran, T.N.; France, D.M.

    1992-01-01

    Results of a study of boiling heat transfer from refrigerant R-113 in a small-diameter (2.92-mm) tube are reported. Local heat transfer coefficients over a range of heat fluxes, mass fluxes, and equilibrium mass qualities were measured. The measured coefficients were used to evaluate eight different heat transfer correlations, some of which have been developed specifically for refrigerants. High heat fluxes and low flow rates are inherent in small channels, and this combination results in high boiling numbers. The high boiling number of the collected data shows that the nucleation mechanism was dominant. As a result, the two-phase correlations that predicted this dominance also predicted the data best if they also properly modeled the physical parameters. The correlations of Lazarek and Black and of Shah, as modified in this study, predicted the data very well. It is also shown that a simple form, suggested by Stephan and Abdelsalam for nucleate boiling, correlates the data equally well. This study is part of a research program in multiphase flow and heat transfer, with the overall objective of developing validated design correlations and predictive methods that will facilitate the design and optimization of compact heat exchangers for use with environmentally acceptable alternatives for chlorofluorocarbon (CFC) refrigerants and refrigerant mixtures.

  11. Nucleate boiling of FC-87/FC-72 zeotropic mixtures on a horizontal copper disc

    NASA Astrophysics Data System (ADS)

    Schlindwein, A. R.; Martin, F. O.; Misale, M.; Passos, J. C.

    2009-05-01

    This paper presents nucleate boiling experimental results, at atmospheric pressure, for heat fluxes q ≤ 40 kW/m2, for FC-87/FC-72 binary mixtures in molar fractions of 0/100, 25/75, 50/50, 75/25, 85/15 and 100/0, at saturation temperatures for pure fluids and bubble points for mixtures. The test section was an upward facing copper disc of 12 mm diameter and 1 mm thickness. The experimental heat transfer coefficient was compared with the correlations of Rohsenow (1952), as reported by Rohsenow et al. (Handbook of heat transfer, McGraw-Hill, New York, 1998), Stephan and Abdelsalam (Int J Heat Mass Transfer 23;73-78, 1978) and Cooper (Int Chem Eng Symp Ser 86:785-792, 1984) for pure fluids and the semi-empirical models of Stephan and Körner (Chem Ing Tech Jahrg 7:409-484, 1969), Thome (J Heat Transfer 104:474-478, 1982), Fujita et al. (1996), as reported by Rohsenow et al. (Handbook of heat transfer, McGraw-Hill, New York, 1998), Fujita and Tsutsui (Int J Heat Mass Transfer 37(1):291-302, 1994) and Calus and Leonidopoulos (Int J Heat Mass Transfer 17:249-256, 1973) for mixtures.

  12. Energy Fluctuation of Ideal Fermi Gas Trapped under Generic Power Law Potential U=\\sum_{i=1}^{d} c_i\\vert x_{i}/a_{i}\\vert^{n_{i} } in d Dimensions

    NASA Astrophysics Data System (ADS)

    Mir Mehedi, Faruk; Md. Muktadir, Rahman; Dwaipayan, Debnath; Md. Sakhawat Hossain, Himel

    2016-04-01

    Energy fluctuation of ideal Fermi gas trapped under generic power law potential U=\\sumi=1d ci \\vertxi/ai \\vert n_i has been calculated in arbitrary dimensions. Energy fluctuation is scrutinized further in the degenerate limit μ ≫ KBT with the help of Sommerfeld expansion. The dependence of energy fluctuation on dimensionality and power law potential is studied in detail. Most importantly our general result can not only exactly reproduce the recently published result regarding free and harmonically trapped ideal Fermi gas in d = 3 but also can describe the outcome for any power law potential in arbitrary dimension.

  13. Some Properties of Transforms in Cultural Theory

    NASA Astrophysics Data System (ADS)

    Ballonoff, Paul

    2010-12-01

    It is shown that, in certain circumstances, systems of cultural rules may be represented by doubly stochastic matrices denoted Π, called “possibility transforms,” and by certain real valued “possibility densities” π=( π 1, π 2,…, π n ) with inner product <π,πrangle=sumiπi2=1. We may characterize a certain problem of ethnographic or ethological description as a problem of prediction, in which observations are predicted by properties of fixed points of transforms of “pure systems”, or by properties of convex combinations of such “pure systems”. Other relationships to quantum methods are noted.

  14. Investigation of Bose Condensation in Ideal Bose Gas Trapped under Generic Power Law Potential in d Dimension

    NASA Astrophysics Data System (ADS)

    Mir Mehedi, Faruk; Md. Sazzad, Hossain; Md. Muktadir, Rahman

    2016-02-01

    The changes in characteristics of Bose condensation of ideal Bose gas due to an external generic power law potential U=\\sumi=1dci\\vert xi/ai\\vertni are studied carefully. Detailed calculation of Kim et al. (J. Phys. Condens. Matter 11 (1999) 10269) yielded the hierarchy of condensation transitions with changing fractional dimensionality. In this manuscript, some theorems regarding specific heat at constant volume CV are presented. Careful examination of these theorems reveal the existence of hidden hierarchy of the condensation transition in trapped systems as well.

  15. Evidence of the existence and eastward motion of superclusters at the Equator

    NASA Technical Reports Server (NTRS)

    Hayashi, Yoshi-Yuki; Nakazawa, Tetsuo

    1989-01-01

    A numerical experiment performed by Hayashi and Sumi (1986) with an atmospheric GCM has shown that moist convection in the equatorial region is spontaneously organized into a form of supercluster (an area of precipitation with a spatial extent of about 2000 km and an eastward propagation speed of about 15 m/sec. Here, the existence of superclusters in the real atmosphere is shown through a comparison between satellite observations and the GCM results. It is argued that eastward motion of convective activity occurs not only as the well-known property of the 30-60-day oscillation, but as a property of synoptic-scale disturbances at the equator.

  16. On the Order of Growth o(\\log\\log n) of the Partial Sums of Fourier-Stieltjes Series of Random Measures

    NASA Astrophysics Data System (ADS)

    Karagulyan, G. A.

    1994-02-01

    Random measures of the form \\displaystyle \\sum_{i=1}^\\infty m_i\\delta_{\\theta_i},\\qquad \\sum_{i=1}^\\infty \\vert m_i\\vert<\\infty,are considered, where \\delta_{\\theta_i} is a unit mass concentrated at the point \\theta_i\\in(0;\\,2\\pi). For any sequence of natural numbers \\{l_k\\}_{k=1}^\\infty it is established that for almost all sequences \\theta=\\{\\theta_i\\}_{i=1}^\\infty the partial sums S_{l_k}(x;\\,d\\mu_{\\theta}) of the Fourier-Stieltjes series of the measure have order o(\\log\\log k) for almost all x\\in(0;\\,2\\pi). As proved by Kahane in 1961, the order o(\\log\\log k) cannot be improved. This result is connected with the well-known problem of Zygmund of finding the exact order of growth of the partial sums of Fourier series almost everywhere.Bibliography: 15 titles.

  17. Nonextensive Statistical Mechanics: Introduction, Dynamical Foundations and Applications

    NASA Astrophysics Data System (ADS)

    Tsallis, Constantino

    2003-03-01

    Many natural and artificial systems exist whose thermostatistical properties appear to be hardly tractable or just untractable within Boltzmann-Gibbes statistical mechanics. Nonextensive statistical mechanics is a generalization of the standard formalism which addresses such systems, typically characterized by long-range interactions, long-range memory, (multi)fractal structures and similar anomalies. This formalism is based on the entropic form Sq = k (1-sumi p_i^q)/(q-1) (S1 = - k sumi pi ln p_i). A brief review of the formalism as well as some illustrative applications will be presented. Finally, the a priori calculation of the entropic index q to be associated with specific systems will be exhibited, starting from the knowledge of the corresponding micorscopic or mesoscopic dynamics. This formalism yields, for nonequilibrium stationary states (e.g., metastable states) and relaxation properties of many ubiquitous systems, asymptotic power-laws, as Boltzmann-Gibbs statistical mechanics yields, for the thermal equilibrium and relaxation properties of standard systems, exponential laws. Bibliography: http://tsallis.cat.cbpf.br/biblio.htm

  18. Exploring the Usability of a Mobile App for Adolescent Obesity Management

    PubMed Central

    Dowdall, Grainne; Burls, Amanda; Perry, Ivan J; Curran, Noirin

    2014-01-01

    Background Obesity is a global epidemic. Behavioral change approaches towards improving nutrition, increasing physical activity level, improving sleep, and reducing sitting time are recommended as best practices in adolescent obesity management. However, access to evidence-based treatment is limited and portable technologies such as mobile apps may provide a useful platform to deliver such lifestyle interventions. No evidence-based validated app exists for obesity intervention; therefore, a novel mobile app (Reactivate) was developed for use in the Temple Street W82GO Healthy Lifestyles Program (W82GO). Objective This study aimed to test the usability (technical effectiveness, efficiency, and user satisfaction) of the Reactivate mobile app in obese adolescents. Methods Ten adolescents (7 males and 3 females, aged 12-17 years) who had been treated for obesity (>98th percentile for body mass index) at the Temple Street Children's University Hospital were recruited. Participants were given 8 tasks to complete in order to test the technical effectiveness of the app. A research assistant timed the user while completing each task in order to test the relative user efficiency of the app (time-on-task). The tasks fell into 5 categories and required the user to enter personal settings, find and answer surveys, create a message, use the goal setting feature, and enter details regarding their weight and height. In exploration of user satisfaction, each participant completed the standardized software usability measurement inventory (SUMI), which measures 5 aspects of user satisfaction: efficiency, effect, helpfulness, controllability, and learnability. Descriptive statistics were used to explore the mean relative user efficiency and SUMI scores. Results Mean age was 14.26 (SD 1.58) years. All adolescents completed each of the tasks successfully. The mean relative user efficiency scores were two to three times that of an expert user. Users responded that they would use

  19. The mass function of primordial rogue planet MACHOs in quasar nano-lensing

    NASA Astrophysics Data System (ADS)

    Schild, Rudolph E.; Nieuwenhuizen, Theo M.; Gibson, Carl H.

    2012-11-01

    The recent Sumi et al (2010 Astrophys. J. 710 1641; 2011 Nature 473 349) detection of free roaming planet mass MACHOs in cosmologically significant numbers recalls their original detection in quasar microlening studies (Colley and Schild 2003 Astrophys. J. 594 97; Schild R E 1996 Astrophys. J. 464 125). We consider the microlensing signature of such a population, and find that the nano-lensing (microlensing) would be well characterized by a statistical microlensing theory published previously by Refsdal and Stabell (1991 Astron. Astrophys. 250 62) Comparison of the observed First Lens microlensing amplitudes with the theoretical prediction gives close agreement and a methodology for determining the slope of the mass function describing the population. Our provisional estimate of the power law exponent in an exponential approximation to this distribution is 2.98+1.0-0.5, where a Salpeter slope is 2.35.

  20. Effect of protein relaxation on electron transfer from the cytochrome subunit to the bacteriochlorophyll dimer in Rps. sulfoviridis reaction centers within mixed adiabatic/nonadiabatic model.

    PubMed

    Kotelnikov, A I; Ortega, J M; Medvedev, E S; Psikha, B L; Garcia, D; Mathis, P

    2002-05-15

    The broad set of nonexponential electron transfer (ET) kinetics in reaction centers (RC) from Rhodopseudomonas sulfoviridis in temperature range 297-40 K are described within a mixed adiabatic/nonadiabatic model. The key point of the model is the combination of Sumi-Marcus and Rips-Jortner approaches which can be represented by the separate contributions of temperature-independent vibrational (v) and temperature-dependent diffusive (d) coordinates to the preexponential factor, to the free energy of reaction DeltaG=DeltaG(v)+DeltaG(d)(T) and to the reorganization energy lambda=lambda(v)+lambda(d)(T). The broad distribution of protein dielectric relaxation times along the diffusive coordinate is considered within the Davidson-Cole formalism. PMID:12009432

  1. A New Approach to Detect Congestive Heart Failure Using Short-Term Heart Rate Variability Measures

    PubMed Central

    Wang, Qian; Zhou, GuangMin; Wang, Ying; Jiang, Qing

    2014-01-01

    Heart rate variability (HRV) analysis has quantified the functioning of the autonomic regulation of the heart and heart's ability to respond. However, majority of studies on HRV report several differences between patients with congestive heart failure (CHF) and healthy subjects, such as time-domain, frequency domain and nonlinear HRV measures. In the paper, we mainly presented a new approach to detect congestive heart failure (CHF) based on combination support vector machine (SVM) and three nonstandard heart rate variability (HRV) measures (e.g. SUM_TD, SUM_FD and SUM_IE). The CHF classification model was presented by using SVM classifier with the combination SUM_TD and SUM_FD. In the analysis performed, we found that the CHF classification algorithm could obtain the best performance with the CHF classification accuracy, sensitivity and specificity of 100%, 100%, 100%, respectively. PMID:24747432

  2. Quantum effect of intramolecular high-frequency vibrational modes on diffusion-controlled electron transfer rate: From the weak to the strong electronic coupling regions

    SciTech Connect

    Zhu, Wenjuan; Zhao, Yi

    2007-05-14

    The Sumi-Marcus theory is extended by introducing two approaches to investigate electron transfer reactions from weak-to-strong electronic coupling regime. One of these approaches is the quantum R-matrix theory, useful for dealing with the intramolecular vibrational motions in the whole electronic coupling domain. The other is the split operator approach that is employed to solve the reaction-diffusion equation. The approaches are then applied to electron transfer in the Marcus inverted regime to investigate the nuclear tunneling effect on the long time rate and the survival probabilities. The numerical results illustrate that the adiabatic suppression obtained from the R-matrix approach is much smaller than that from the Landau-Zener theory whereas it cannot be predicted by the perturbation theory. The jointed effects of the electronic coupling and solvent relaxation time on the rates are also explored.

  3. Design, Implementation, and Wide Pilot Deployment of FitForAll: An Easy to use Exergaming Platform Improving Physical Fitness and Life Quality of Senior Citizens.

    PubMed

    Konstantinidis, Evdokimos I; Billis, Antonis S; Mouzakidis, Christos A; Zilidou, Vasiliki I; Antoniou, Panagiotis E; Bamidis, Panagiotis D

    2016-01-01

    Many platforms have emerged as response to the call for technology supporting active and healthy aging. Key requirements for any such e-health systems and any subsequent business exploitation are tailor-made design and proper evaluation. This paper presents the design, implementation, wide deployment, and evaluation of the low cost, physical exercise, and gaming (exergaming) FitForAll (FFA) platform system usability, user adherence to exercise, and efficacy are explored. The design of FFA is tailored to elderly populations, distilling literature guidelines and recommendations. The FFA architecture introduces standard physical exercise protocols in exergaming software engineering, as well as, standard physical assessment tests for augmented adaptability through adjustable exercise intensity. This opens up the way to next generation exergaming software, which may be more automatically/smartly adaptive. 116 elderly users piloted FFA five times/week, during an eight-week controlled intervention. Usability evaluation was formally conducted (SUS, SUMI questionnaires). Control group consisted of a size-matched elderly group following cognitive training. Efficacy was assessed objectively through the senior fitness (Fullerton) test, and subjectively, through WHOQoL-BREF comparisons of pre-postintervention between groups. Adherence to schedule was measured by attendance logs. The global SUMI score was 68.33±5.85%, while SUS was 77.7. Good usability perception is reflected in relatively high adherence of 82% for a daily two months pilot schedule. Compared to control group, elderly using FFA improved significantly strength, flexibility, endurance, and balance while presenting a significant trend in quality of life improvements. This is the first elderly focused exergaming platform intensively evaluated with more than 100 participants. The use of formal tools makes the findings comparable to other studies and forms an elderly exergaming corpus. PMID:26731797

  4. Invariant sums of random matrices and the onset of level repulsion

    NASA Astrophysics Data System (ADS)

    Burda, Zdzisław; Livan, Giacomo; Vivo, Pierpaolo

    2015-06-01

    We compute analytically the joint probability density of eigenvalues and the level spacing statistics for an ensemble of random matrices with interesting features. It is invariant under the standard symmetry groups (orthogonal and unitary) and yet the interaction between eigenvalues is not Vandermondian. The ensemble contains real symmetric or complex Hermitian matrices S of the form {S}=\\sumi=1M < {O}i {D}_i{O}_iT> or {S}=\\sumi=1M < {U}i {D}_i{U}_i^\\dagger> respectively. The diagonal matrices {D}_i=diag\\{λ_1(i),\\ldots,λ_N(i)\\} are constructed from real eigenvalues drawn independently from distributions p(i)(x), while the matrices Oi and Ui are all orthogonal or unitary. The average <·> is simultaneously performed over the symmetry group and the joint distribution of \\{λ_j(i)\\} . We focus on the limits (i.) N → ∞ and (ii.) M → ∞, with N = 2. In the limit (i.), the resulting sum S develops level repulsion even though the original matrices do not feature it, and classical RMT universality is restored asymptotically. In the limit (ii.) the spacing distribution attains scaling forms that are computed exactly: for the orthogonal case, we recover the β = 1 Wigner's surmise, while for the unitary case an entirely new universal distribution is obtained. Our results allow to probe analytically the microscopic statistics of the sum of random matrices that become asymptotically free. We also give an interpretation of this model in terms of radial random walks in a matrix space. The analytical results are corroborated by numerical simulations.

  5. [INCIDENCE, PREDISPOSING RISK FACTORS FOR THE DEVELOPMENT AND SPREADING OF ACUTE INTESTINAL INFECTIONS IN THE NORTH-EASTERN REGION OF UKRAINE].

    PubMed

    Malysh, N G; Chemych, N D; Zaritsky, A M

    2016-01-01

    Using data of the branch statistical reporting of the State Sanitary and Epidemiological Service in Sumy region and Sumy Regional State Laboratory of Veterinary Medicine, the incidence rate, modern risk factors for the development and spreading of acute infectious diarrheas were determined in the North-Eastern region of Ukraine. Under the current conditions incidence rate indices of acute intestinal infections and food toxicoinfections are within the range of 159.8-193.6 per 100 thousands. pop. Seasonal and epidemical rises are associated with a species of the agent. In the etiological structure of acute diarrheal infections there are dominated viruses, of food toxicoinfections--Klebsiellae pneumoniae, Staphylococcus aureus and Enterobacter cloacae (p < 0.05). Predictors of the complication of epidemiological situation of Shigella infections are the gain in the detection of bacterially contaminated samples of milk and dairy products (r = 0.75), for food toxicoinfections caused by Klebsiellae pneumoniae and Enterobacter cloacae--pastry with cream and cooking meat products (r = 0.64; r = 0.75). Epizootic situation in the region affects on the salmonellosis incidence rate of the population (r = 0.89). There were revealed correlations between the selection of E. coli bacteria from swabs taken from the enterprises of catering, in child care centers and the levels of incidence rates of salmonellosis, acute intestinal infections of unknown etiology (r = 0.59; r = 0.60). Timely detection and sanitation of Shigella carriers are a powerful instrument to reduce the incidence rate of shigellosis (r = 0.83). PMID:27266031

  6. Usability testing of a monitoring and feedback tool to stimulate physical activity

    PubMed Central

    van der Weegen, Sanne; Verwey, Renée; Tange, Huibert J; Spreeuwenberg, Marieke D; de Witte, Luc P

    2014-01-01

    Introduction A monitoring and feedback tool to stimulate physical activity, consisting of an activity sensor, smartphone application (app), and website for patients and their practice nurses, has been developed: the ‘It’s LiFe!’ tool. In this study the usability of the tool was evaluated by technology experts and end users (people with chronic obstructive pulmonary disease or type 2 diabetes, with ages from 40–70 years), to improve the user interfaces and content of the tool. Patients and methods The study had four phases: 1) a heuristic evaluation with six technology experts; 2) a usability test in a laboratory by five patients; 3) a pilot in real life wherein 20 patients used the tool for 3 months; and 4) a final lab test by five patients. In both lab tests (phases 2 and 4) qualitative data were collected through a thinking-aloud procedure and video recordings, and quantitative data through questions about task complexity, text comprehensiveness, and readability. In addition, the post-study system usability questionnaire (PSSUQ) was completed for the app and the website. In the pilot test (phase 3), all patients were interviewed three times and the Software Usability Measurement Inventory (SUMI) was completed. Results After each phase, improvements were made, mainly to the layout and text. The main improvement was a refresh button for active data synchronization between activity sensor, app, and server, implemented after connectivity problems in the pilot test. The mean score on the PSSUQ for the website improved from 5.6 (standard deviation [SD] 1.3) to 6.5 (SD 0.5), and for the app from 5.4 (SD 1.5) to 6.2 (SD 1.1). Satisfaction in the pilot was not very high according to the SUMI. Discussion The use of laboratory versus real-life tests and expert-based versus user-based tests revealed a wide range of usability issues. The usability of the It’s LiFe! tool improved considerably during the study. PMID:24669188

  7. Level repulsion exponent β for many-body localization transitions and for Anderson localization transitions via Dyson Brownian motion

    NASA Astrophysics Data System (ADS)

    Monthus, Cécile

    2016-03-01

    The generalization of the Dyson Brownian motion approach of random matrices to Anderson localization (AL) models (Chalker et al 1996 Phys. Rev. Lett. 77 554) and to many-body localization (MBL) Hamiltonians (Serbyn and Moore 2015 arXiv:1508.07293) is revisited to extract the level repulsion exponent β, where β =1 in the delocalized phase governed by the Wigner-Dyson statistics, β =0 , in the localized phase governed by the Poisson statistics, and 0<{βc}<1 at the critical point. The idea is that the Gaussian disorder variables h i are promoted to Gaussian stationary processes h i (t) in order to sample the disorder stationary distribution with some time correlation τ. The statistics of energy levels can then be studied via Langevin and Fokker-Planck equations. For the MBL quantum spin Hamiltonian with random fields h i , we obtain β =2qn,n+1\\text{EA}(N)/qn,n\\text{EA}(N) in terms of the Edwards-Anderson matrix qnm\\text{EA}(N)\\equiv \\frac{1}{N}{\\sum}i=1N|< {φn}|σ iz|{φm}> {{|}2} for the same eigenstate m  =  n and for consecutive eigenstates m  =  n  +  1. For the Anderson localization tight-binding Hamiltonian with random on-site energies h i , we find β =2{{Y}n,n+1}(N)/≤ft({{Y}n,n}(N)-{{Y}n,n+1}(N)\\right) in terms of the density correlation matrix {{Y}nm}(N)\\equiv {\\sum}i=1N|< {φn}|i> {{|}2}|< i|{φm}> {{|}2} for consecutive eigenstates m  =  n  +  1, while the diagonal element m  =  n corresponds to the inverse participation ratio {{Y}nn}(N)\\equiv {\\sum}i=1N|< {φn}|i> {{|}4} of the eigenstate |{φn}> .

  8. The Strain Energy, Seismic Moment and Magnitudes of Large Earthquakes

    NASA Astrophysics Data System (ADS)

    Purcaru, G.

    2004-12-01

    The strain energy Est, as potential energy, released by an earthquake and the seismic moment Mo are two fundamental physical earthquake parameters. The earthquake rupture process ``represents'' the release of the accumulated Est. The moment Mo, first obtained in 1966 by Aki, revolutioned the quantification of earthquake size and led to the elimination of the limitations of the conventional magnitudes (originally ML, Richter, 1930) mb, Ms, m, MGR. Both Mo and Est, not in a 1-to-1 correspondence, are uniform measures of the size, although Est is presently less accurate than Mo. Est is partitioned in seismic- (Es), fracture- (Eg) and frictional-energy Ef, and Ef is lost as frictional heat energy. The available Est = Es + Eg (Aki and Richards (1980), Kostrov and Das, (1988) for fundamentals on Mo and Est). Related to Mo, Est and Es, several modern magnitudes were defined under various assumptions: the moment magnitude Mw (Kanamori, 1977), strain energy magnitude ME (Purcaru and Berckhemer, 1978), tsunami magnitude Mt (Abe, 1979), mantle magnitude Mm (Okal and Talandier, 1987), seismic energy magnitude Me (Choy and Boatright, 1995, Yanovskaya et al, 1996), body-wave magnitude Mpw (Tsuboi et al, 1998). The available Est = (1/2μ )Δ σ Mo, Δ σ ~=~average stress drop, and ME is % \\[M_E = 2/3(\\log M_o + \\log(\\Delta\\sigma/\\mu)-12.1) ,\\] % and log Est = 11.8 + 1.5 ME. The estimation of Est was modified to include Mo, Δ and μ of predominant high slip zones (asperities) to account for multiple events (Purcaru, 1997): % \\[E_{st} = \\frac{1}{2} \\sum_i {\\frac{1}{\\mu_i} M_{o,i} \\Delta\\sigma_i} , \\sum_i M_{o,i} = M_o \\] % We derived the energy balance of Est, Es and Eg as: % \\[ E_{st}/M_o = (1+e(g,s)) E_s/M_o , e(g,s) = E_g/E_s \\] % We analyzed a set of about 90 large earthquakes and found that, depending on the goal these magnitudes quantify differently the rupture process, thus providing complementary means of earthquake characterization. Results for some

  9. Order and disorder and their influences on optical absorption of glasses in the gap region

    NASA Astrophysics Data System (ADS)

    Baník, Ivan; Kubliha, Marian; Labaš, Vladimír; Lukovičová, Jozefa; Pavlendová, Gabriela; Šín, Peter

    2016-07-01

    The exponential increase of the absorption coefficient near the absorption edge is usually explained by existence of the density-of-states tails. Among the quoted theoretical models which are widely used to explain the manifestations of the Urbach rule in semiconductors, are the Sumi-Toyozava and the Dow-Redfield models and ab initio (from begining) theory. Our barrier-cluster-heating model assumes the different creating mechanism of exponential tails. The energy by optical transition is provided to electrons except from photons also from vibration of microregion. It deals about the replenishment of absented photons energy, which is smaller as gap width. Absented energy needed for the transition by light absorption is acumulated in certain microregions of material in the form of vibrational energy. At absorption sufficiently big package of accumulated energy can be used. Energy of emptied microarea is filled by phonons from surrounding of microarea (as result of temperature status of surrounding), resp. phonons of optical background wich are created in given microarea at non radiative recombination of carriers. In this work simplified process at derivating of Urbach rule is listed.

  10. Using K2 to Find Free-floating Planets

    NASA Astrophysics Data System (ADS)

    Henderson, Calen B.

    2016-01-01

    In 2011, Sumi et al. announced the discovery of an excess of short-timescale microlensing events, which they inferred to be caused by a population of unbound planetary-mass objects. Their result implies that these free-floating planet candidates may constitute an overwhelming fraction of the mass budget for planet formation. K2's Campaign 9 (K2C9) will conduct a ~4 square-degree microlensing survey toward the Galactic bulge and is our first and potentially only opportunity to perform a synoptic survey to measure the masses of a substantial number of short-timescale events. The ˜0.5 AU baseline between K2 and the Earth during C9 will facilitate satellite parallax measurements for short-timescale events, with durations of ˜1 day, which will identify that the cause of the event is in fact a very low-mass object, i.e., a free-floating planet candidate. By taking near-infrared (NIR) photometry during the event and comparing to high-resolution NIR photometry after the event is over, we can then distinguish between a planet that is widely separated from but gravitationally bound to a host star and one that is truly free-floating. Here we overview this procedure, describe the resources available to accomplish it, and detail the expected yields.

  11. A cis-element with mixed G-quadruplex structure of NPGPx promoter is essential for nucleolin-mediated transactivation on non-targeting siRNA stress

    PubMed Central

    Wei, Pei-Chi; Wang, Zi-Fu; Lo, Wen-Ting; Su, Mei-I; Shew, Jin-Yuh; Chang, Ta-Chau; Lee, Wen-Hwa

    2013-01-01

    We reported that non-targeting siRNA (NT-siRNA) stress induces non-selenocysteine containing phospholipid hydroperoxide glutathione peroxidase (NPGPx) expression to cooperate with exoribonuclease XRN2 for releasing the stress [Wei,P.C., Lo,W.T., Su,M.I., Shew,J.Y. and Lee,W.H. (2011) Non-targeting siRNA induces NPGPx expression to cooperate with exoribonuclease XRN2 for releasing the stress. Nucleic Acids Res., 40, 323–332]. However, how NT-siRNA stress inducing NPGPx expression remains elusive. In this communication, we showed that the proximal promoter of NPGPx contained a mixed G-quadruplex (G4) structure, and disrupting the structure diminished NT-siRNA induced NPGPx promoter activity. We also demonstrated that nucleolin (NCL) specifically bonded to the G4-containing sequences to replace the originally bound Sp1 at the NPGPx promoter on NT-siRNA stress. Consistently, overexpression of NCL further increased NPGPx promoter activity, whereas depletion of NCL desensitized NPGPx promoter to NT-siRNA stress. These results suggest that the cis-element with mixed G4 structure at the NPGPx promoter plays an essential role for its transactivation mediated by NCL to release cells from NT-siRNA stress. PMID:23241391

  12. Gas dynamic design of the pipe line compressor with 90% efficiency. Model test approval

    NASA Astrophysics Data System (ADS)

    Galerkin, Y.; Rekstin, A.; Soldatova, K.

    2015-08-01

    Gas dynamic design of the pipe line compressor 32 MW was made for PAO SMPO (Sumy, Ukraine). The technical specification requires compressor efficiency of 90%. The customer offered favorable scheme - single-stage design with console impeller and axial inlet. The authors used the standard optimization methodology of 2D impellers. The original methodology of internal scroll profiling was used to minimize efficiency losses. Radically improved 5th version of the Universal modeling method computer programs was used for precise calculation of expected performances. The customer fulfilled model tests in a 1:2 scale. Tests confirmed the calculated parameters at the design point (maximum efficiency of 90%) and in the whole range of flow rates. As far as the authors know none of compressors have achieved such efficiency. The principles and methods of gas-dynamic design are presented below. The data of the 32 MW compressor presented by the customer in their report at the 16th International Compressor conference (September 2014, Saint- Petersburg) and later transferred to the authors.

  13. Assessment of the usability and impact of the Idaho Health Data Exchange (IHDE).

    PubMed

    Reis, Janet; MacKenzie, Lisa; Soelberg, Terri; Smith, Jennifer

    2016-04-01

    Eighty four health care professionals participated in an online survey assessing the usability, and clinical and administrative impact of the Idaho Health Data Exchange's (IHDE) Virtual Health Record (VHR). The IHDE VHR allows authorized users to use a secure web interface to view lab, radiology and transcribed reports from multiple facilities and view medical histories on patients in the data exchange. Results indicate the usability of the IHDE VHR was almost universally positively rated with the Software Usability Measurement Inventory (SUMI) utilized as the assessment method. Medical providers however had the lowest rating of the exchange, raising concerns about the need for additional training and support. The addition of other Idaho health care organizations to the health data exchange was most widely desired, with the most frequently cited benefit being more comprehensive access to patients' records. In contrast to other published evaluations of health data exchanges in the U.S., few of the concerns emerged about cost of implementation of the data exchange or trust in the quality of information contained therein. PMID:26875079

  14. A cis-element with mixed G-quadruplex structure of NPGPx promoter is essential for nucleolin-mediated transactivation on non-targeting siRNA stress.

    PubMed

    Wei, Pei-Chi; Wang, Zi-Fu; Lo, Wen-Ting; Su, Mei-I; Shew, Jin-Yuh; Chang, Ta-Chau; Lee, Wen-Hwa

    2013-02-01

    We reported that non-targeting siRNA (NT-siRNA) stress induces non-selenocysteine containing phospholipid hydroperoxide glutathione peroxidase (NPGPx) expression to cooperate with exoribonuclease XRN2 for releasing the stress [Wei,P.C., Lo,W.T., Su,M.I., Shew,J.Y. and Lee,W.H. (2011) Non-targeting siRNA induces NPGPx expression to cooperate with exoribonuclease XRN2 for releasing the stress. Nucleic Acids Res., 40, 323-332]. However, how NT-siRNA stress inducing NPGPx expression remains elusive. In this communication, we showed that the proximal promoter of NPGPx contained a mixed G-quadruplex (G4) structure, and disrupting the structure diminished NT-siRNA induced NPGPx promoter activity. We also demonstrated that nucleolin (NCL) specifically bonded to the G4-containing sequences to replace the originally bound Sp1 at the NPGPx promoter on NT-siRNA stress. Consistently, overexpression of NCL further increased NPGPx promoter activity, whereas depletion of NCL desensitized NPGPx promoter to NT-siRNA stress. These results suggest that the cis-element with mixed G4 structure at the NPGPx promoter plays an essential role for its transactivation mediated by NCL to release cells from NT-siRNA stress. PMID:23241391

  15. Elliptical varied line-space (EVLS) gratings

    NASA Astrophysics Data System (ADS)

    Thomas, Roger J.

    2004-10-01

    Imaging spectroscopy at wavelengths below 2000 Å offers an especially powerful method for studying many extended high-temperature astronomical objects, like the Sun and its outer layers. But the technology to make such measurements is also especially challenging, because of the poor reflectance of all standard materials at these wavelengths, and because the observation must be made from above the absorbing effects of the Earth's atmosphere. To solve these problems, single-reflection stigmatic spectrographs for XUV wavelengths have bee flown on several space missions based on designs with toroidal uniform line-space (TULS) or spherical varied line-space (SVLS) gratings that operate at near normal-incidence. More recently, three solar EUV/UV instruments have been selected that use toroidal varied line-space (TVLS) gratings; these are SUMI and RAISE, both sounding rocket payloads, and NEXUS, a SMEX satellite-mission. The next logical extension to such designs is the use of elliptical surfaces for varied line-space (EVLS) rulings. In fact, EVLS designs are found to provide superior imaging even at very large spectrograph magnifications and beam-speeds, permitting extremely high-quality performance in remarkably compact instrument packages. In some cases, such designs may be optimized even further by using a hyperbolic surface for the feeding telescope. The optical characteristics of two solar EUV spectrometers based on these concepts are described: EUS and EUI, both being developed as possible instruments for ESA's Solar Orbiter mission by consortia led by RAL and by MSSL, respectively.

  16. Unified expression for the rate constant of the bridged electron transfer derived by renormalization

    SciTech Connect

    Saito, Keisuke; Sumi, Hitoshi

    2009-10-07

    Electron transfer (ET) from a donor to an acceptor through an energetically close intermediary state on a midway molecule is a process found often in natural and artificial solar-energy capturing systems such as photosynthesis. This process has often been thought of in terms of opposing 'superexchange' and 'sequential or hopping' mechanisms, and the recent theory of Sumi and Kakitani (SK) [J. Phys. Chem. B 105, 9603 (2001)] has shown an interpolation between these mechanisms. In their theory, however, dynamics governing the most interesting intermediary region between them has artificially been introduced by phenomenologies. The dynamics is played by decoherence among electronic states, their decay, and thermalization of phonons in the medium. The present work clarifies the dynamics on a microscopic basis by means of renormalization in electronic coupling among the states, and gives a complete unified expression of the rate constant of the ET. It merges to that given by the SK theory in the semiclassical approximation for phonons interacting with an electron transferred.

  17. Beyond Effectiveness: A Pragmatic Evaluation Framework for Learning and Continuous Quality Improvement of e-Learning Interventions in Healthcare.

    PubMed

    Dafalla, Tarig Dafalla Mohamed; Kushniruk, Andre W; Borycki, Elizabeth M

    2015-01-01

    A pragmatic evaluation framework for evaluating the usability and usefulness of an e-learning intervention for a patient clinical information scheduling system is presented in this paper. The framework was conceptualized based on two different but related concepts (usability and usefulness) and selection of appropriate and valid methods of data collection and analysis that included: (1) Low-Cost Rapid Usability Engineering (LCRUE), (2) Cognitive Task Analysis (CTA), (3) Heuristic Evaluation (HE) criteria for web-based learning, and (4) Software Usability Measurement Inventory (SUMI). The results of the analysis showed some areas where usability that were related to General Interface Usability (GIU), instructional design and content was problematic; some of which might account for the poorly rated aspects of usability when subjectively measured. This paper shows that using a pragmatic framework can be a useful way, not only for measuring the usability and usefulness, but also for providing a practical objective evidences for learning and continuous quality improvement of e-learning systems. The findings should be of interest to educators, developers, designers, researchers, and usability practitioners involved in the development of e-learning systems in healthcare. This framework could be an appropriate method for assessing the usability, usefulness and safety of health information systems both in the laboratory and in the clinical context. PMID:25676959

  18. Nonlocal diffusion problems that approximate a parabolic equation with spatial dependence

    NASA Astrophysics Data System (ADS)

    Molino, Alexis; Rossi, Julio D.

    2016-06-01

    In this paper, we show that smooth solutions to the Dirichlet problem for the parabolic equation v_t(x,t)=sum_{i,j=1}N a_{ij}(x)partial2v(x,t)/partial{xipartial{x}j} + sum_{i =1}N bi(x)partial{v}(x,t)/partial{x_i} qquad x in Ω, with v( x, t) = g( x, t), {x in partial Ω,} can be approximated uniformly by solutions of nonlocal problems of the form ut^{\\varepsilon}(x,t)=int_{mathbb{R}n} K_{\\varepsilon}(x,y)(u^{\\varepsilon}(y,t)-u^{\\varepsilon}(x,t))dy, quad x in Ω, with {u^{\\varepsilon}(x,t)=g(x,t)}, {x notin Ω}, as {\\varepsilon to 0}, for an appropriate rescaled kernel {K_{\\varepsilon}}. In this way, we show that the usual local evolution problems with spatial dependence can be approximated by nonlocal ones. In the case of an equation in divergence form, we can obtain an approximation with symmetric kernels, that is, {K_{\\varepsilon}(x,y) = K_{\\varepsilon}(y,x)}.

  19. Molecular Understanding of Efficient DNA Repair Machinery of Photolyase

    NASA Astrophysics Data System (ADS)

    Tan, Chuang; Liu, Zheyun; Li, Jiang; Guo, Xunmin; Wang, Lijuan; Zhong, Dongping

    2012-06-01

    Photolyases repair the UV-induced pyrimidine dimers in damage DNA with high efficiency, through a cylic light-driven electron transfer radical mechanism. We report here our systematic studies of the repair dynamics in E. coli photolyase with mutation of five active-site residues. The significant loss of repair efficiency by the mutation indicates that those active-site residues play an important role in the DNA repair by photolyase. To understand how the active-site residues modulate the efficiency, we mapped out the entire evolution of each elementary step during the repair in those photolyase mutants with femtosecond resolution. We completely analyzed the electron transfer dynamics using the Sumi-Marcus model. The results suggest that photolyase controls the critical electron transfer and the ring-splitting of pyrimidine dimer through modulation of the redox potentials and reorganization energies, and stabilization of the anionic intermediates, maintaining the dedicated balance of all the reaction steps and achieving the maximum function activity.

  20. Free-floating planets from core accretion theory: microlensing predictions

    NASA Astrophysics Data System (ADS)

    Ma, Sizheng; Mao, Shude; Ida, Shigeru; Zhu, Wei; Lin, Douglas N. C.

    2016-09-01

    We calculate the microlensing event rate and typical time-scales for the free-floating planet (FFP) population that is predicted by the core accretion theory of planet formation. The event rate is found to be ˜1.8 × 10-3 of that for the stellar population. While the stellar microlensing event time-scale peaks at around 20 d, the median time-scale for FFP events (˜0.1 d) is much shorter. Our values for the event rate and the median time-scale are significantly smaller than those required to explain the Sumi et al. result, by factors of ˜13 and ˜16, respectively. The inclusion of planets at wide separations does not change the results significantly. This discrepancy may be too significant for standard versions of both the core accretion theory and the gravitational instability model to explain satisfactorily. Therefore, either a modification to the planet formation theory is required or other explanations to the excess of short-time-scale microlensing events are needed. Our predictions can be tested by ongoing microlensing experiment such as Korean Microlensing Telescope Network, and by future satellite missions such as WFIRST and Euclid.

  1. [The effect of anthropogenic transformation on the conditions for the circulation of the causative agent of opisthorchiasis].

    PubMed

    Beér, S A; Danilenko, L N; German, S M; Kolesnik, E I

    1990-01-01

    The conditions of O. felineus circulations in the area of minor hydraulic constructions of Graĭvoron on the Vorskla River where a tense Ukrainian focus of opisthorchiasis existed (the village of Dobryanskoye, Sumy Province) were followed up for a 8-year period (since 1982). Hydraulic construction near the Vorskla River resulted in a significant violation of the ecological balance (macrocyte occupation of the river bed and the bay terrace, bog-making, dystrophic changes of the low-land bodies of water). The aforementioned circumstances influenced the conditions of O. felineus circulation (decreased number of Codiella mollusk habitats, decreased density of the mollusks and their invasion rate with larvivorous forms of Opisthorchis, lower invasion rate in carps). The considered processes are now characteristic of many minor rivers in the Ukraine. Though their negative impact on the ecological conditions causes no doubt it should be taken into account and used for the eradication of Opisthorchis foci (in combination with therapeutic and sanitary education measures). PMID:2377144

  2. Checking an integrated model of web accessibility and usability evaluation for disabled people.

    PubMed

    Federici, Stefano; Micangeli, Andrea; Ruspantini, Irene; Borgianni, Stefano; Corradi, Fabrizio; Pasqualotto, Emanuele; Olivetti Belardinelli, Marta

    2005-07-01

    A combined objective-oriented and subjective-oriented method for evaluating accessibility and usability of web pages for students with disability was tested. The objective-oriented approach is devoted to verifying the conformity of interfaces to standard rules stated by national and international organizations responsible for web technology standardization, such as W3C. Conversely, the subjective-oriented approach allows assessing how the final users interact with the artificial system, accessing levels of user satisfaction based on personal factors and environmental barriers. Five kinds of measurements were applied as objective-oriented and subjective-oriented tests. Objective-oriented evaluations were performed on the Help Desk web page for students with disability, included in the website of a large Italian state university. Subjective-oriented tests were administered to 19 students labeled as disabled on the basis of their own declaration at the University enrolment: 13 students were tested by means of the SUMI test and six students by means of the 'Cooperative evaluation'. Objective-oriented and subjective-oriented methods highlighted different and sometimes conflicting results. Both methods have pointed out much more consistency regarding levels of accessibility than of usability. Since usability is largely affected by individual differences in user's own (dis)abilities, subjective-oriented measures underscored the fact that blind students encountered much more web surfing difficulties. PMID:16096230

  3. Reflections on urban science teacher-student self-efficacy dynamics

    NASA Astrophysics Data System (ADS)

    Hagiwara, Sumi; Maulucci, Maria S. Rivera; Ramos, S. Lizette

    2011-12-01

    This forum article consists of commentaries—authored by Sumi Hagiwara, Maria S. Rivera Maulucci and Lizette Ramos—on the feature article by Virginia Jennings Bolshakova, Carla C. Johnson, and Charlene M. Czerniak. We reflect on a series of questions that take retrospective, introspective, and prospective views of self-efficacy in science education. We review selected studies that explore some of the historical developments and methodological approaches in the literature and examine a teacher-student self-efficacy system model that shows the ways in which teachers' and students' self-efficacy judgments are based upon multiple individual and shared components, such as identity and social interaction within the classroom and school. We close with a call for the design of measures of teacher-student self-efficacy systems, so that we can begin to tailor professional development experiences to the goals and motivations of individual and collective groups of teachers and students in ways that accommodate the unique cultural features of their classrooms and foster student self-efficacy.

  4. Retrieval of Latent Heating from TRMM Measurements

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Smith, E. A.; Adler, R. F.; Hou, A. Y.; Meneghini, R.; Simpson, J.; Haddad, Z. S.; Iguchi, T.; Satoh, S.; Kakar, R.; Krishnamurti, T. N.; Kummerow, C. D.; Lang, S.; Nakamura, K.; Nakazawa, T.; Okamoto, K.; Shige, S.; Olson, W. S.; Takayabu, Y.; Tripoli, G. J.; Yang, S.

    2006-01-01

    Precipitation, in driving the global hydrological cycle, strongly influences the behavior of the Earth's weather and climate systems and is central to their variability. Two-thirds of the global rainfall occurs over the Tropics, which leads to its profound effect on the general circulation of the atmosphere. This is because its energetic equivalent, latent heating (LH), is the tropical convective heat engine's primary fuel source as originally emphasized by Riehl and Malkus (1958). At low latitudes, LH stemming from extended bands of rainfall modulates large-scale zonal and meridional circulations and their consequent mass overturnings (e.g., Hartmann et al. 1984; Hack and Schubert 1990). Also, LH is the principal energy source in the creation, growth, vertical structure, and propagation of long-lived tropical waves (e.g., Puri 1987; Lau and Chan 1988). Moreover, the distinct vertical distribution properties of convective and stratiform LH profiles help influence climatic outcomes via their tight control on large-scale circulations (Lau and Peng 1987; Nakazawa 1988; Sui and Lau 1988; Emanuel et al. 1994; Yanai et al. 2000; Sumi and Nakazawa 2002; Schumacher et al. 2004). The purpose of this paper is to describe how LH profiles are being derived from satellite precipitation rate retrievals, focusing on those being made with Tropical Rainfall Measuring Mission (TRMM) satellite measurements.

  5. Sources of SOA gaseous precursors in contrasted urban environments: a focus on mono-aromatic compounds and intermediate volatility compounds

    NASA Astrophysics Data System (ADS)

    Salameh, Therese; Borbon, Agnès; Ait-Helal, Warda; Afif, Charbel; Sauvage, Stéphane; Locoge, Nadine; Bonneau, Stéphane; Sanchez, Olivier

    2016-04-01

    , SP95 E10, and SP98) and was used to constraint evaporative emissions in order to predict the headspace vapour composition (Harley and Coulter-Burke, 2000). Modelled and observed compositions are in good agreement (differences up to 20%). Therefore, the implemented model is a relevant tool to test the sensitivity of BTEX and other VOCs ambient composition to evaporative emissions of fuels with regards to their composition. Such analysis will be extended to other target cities and similarities/differences will be presented regarding regional characteristics. This work was supported by the Ile de France region, Life and PHOTOPAQ grant, PICS-CNRS, ENVIMED and ChArMEx. We would like to thank Laurence Dépelchin and Thierry Léonardis for technical support and AIRPARIF for providing the data. Borbon, A., et al. (2013) Emission ratios of anthropogenic VOC in northern mid-latitude megacities: observations vs. emission inventories in Los Angeles and Paris, J. Geophys. Res. 118, 2041 - 2057. Harley, R. and Coulter-Burke, S. (2000) Relating Liquid Fuel and Headspace Vapor Composition for California Reformulated Gasoline Samples Containing Ethanol, Environ. Sci. Technol. 34, 4088-4094. Ait-Helal, W.; Borbon, A.; Sauvage, S.; et al., Atmos. Chem. Phys. vol. 14 , No. 19 , p. 10439-10464

  6. Analysis of the influence of tectonics on the evolution valley network based on the SRTM DEM and the relationship of automatically extracted lineaments and the tectonic faults, Jemma River basin, Ethiopia

    NASA Astrophysics Data System (ADS)

    Kusák, Michal

    2016-04-01

    visualization in GIS identifies a larger number of shorter lineaments than lineaments by visual interpretation. Key words: valley network, lineaments, faults, azimuth, Jemma River basin, Ethiopian Highlands GANI, N., D., ABDELSALAM, M., G., GERA, S., GANI, M., R. (2009): Stratigraphic and structural evolution of the Blue Nile Basin, Northweastern Ethiopian Plateau. Geologic Journal, 44, s. 30-56. KAZMIN, V. (1975): Geological Map of Ethiopia. Geological Survey of Ethiopia, Adrie Ababa, Ethiopia. MANGESHA, T., CHERNET, T., HARO, W. (1996): Geological Map Of Ethiopia (1: 250,000). Geological Survey of Ethiopia: Addis Ababa, Ethiopia. PIK, R., MARTY, B., CARIGNAN, J., LAVÉ, J. (2003): Stability of the Upper Nile drainage network (Ethiopia) deduces from (U/Th)/He thermochronometry: implications for uplift and erosion of the Afar plume dome. and Planetary Science Letters, 215, s. 73 - 88.

  7. Obituary: Jason G. Porter, 1954-2005

    NASA Astrophysics Data System (ADS)

    Hathaway, David H.

    2005-12-01

    development of a solar ultraviolet magnetograph instrument (SUMI) capable of measuring vector magnetic fields in the upper chromosphere and transition region where the magnetic reconnection that powers solar flares and CMEs is believed to occur. He continued to provide inspiring leadership to the development of SUMI up until the last month of his life. Jason was admired by his colleagues on both a professional and personal level. He also had a rich life outside of his professional work. He loved the outdoors - hiking, camping, and fishing in particular. He loved music. Bluegrass was one of his favorites. He played the steel guitar, the Dobro, and the trombone, and spent many evenings playing in a local bluegrass band. He also loved finely crafted lagers and ales and would occasionally bring some strange brew to liven up an evening of poker. Jason and Linda have two sons, Graham (13) and Allen (11). All who knew him well will miss him dearly.

  8. An analytical continuation approach for evaluating emission lineshapes of molecular aggregates and the adequacy of multichromophoric Förster theory

    NASA Astrophysics Data System (ADS)

    Banchi, Leonardo; Costagliola, Gianluca; Ishizaki, Akihito; Giorda, Paolo

    2013-05-01

    In large photosynthetic chromophore-protein complexes not all chromophores are coupled strongly, and thus the situation is well described by formation of delocalized states in certain domains of strongly coupled chromophores. In order to describe excitation energy transfer among different domains without performing extensive numerical calculations, one of the most popular techniques is a generalization of Förster theory to multichromophoric aggregates (generalized Förster theory) proposed by Sumi [J. Phys. Chem. B 103, 252 (1999), 10.1021/jp983477u] and Scholes and Fleming [J. Phys. Chem. B 104, 1854 (2000), 10.1021/jp993435l]. The aim of this paper is twofold. In the first place, by means of analytic continuation and a time convolutionless quantum master equation approach, a theory of emission lineshape of multichromophoric systems or molecular aggregates is proposed. In the second place, a comprehensive framework that allows for a clear, compact, and effective study of the multichromophoric approach in the full general version proposed by Jang, Newton, and Silbey [Phys. Rev. Lett. 92, 218301 (2004), 10.1103/PhysRevLett.92.218301] is developed. We apply the present theory to simple paradigmatic systems and we show on one hand the effectiveness of time-convolutionless techniques in deriving lineshape operators and on the other hand we show how the multichromophoric approach can give significant improvements in the determination of energy transfer rates in particular when the systems under study are not the purely Förster regime. The presented scheme allows for an effective implementation of the multichromophoric Förster approach which may be of use for simulating energy transfer dynamics in large photosynthetic aggregates, for which massive computational resources are usually required. Furthermore, our method allows for a systematic comparison of multichromophoric Föster and generalized Förster theories and for a clear understanding of their respective limits

  9. Can the Masses of Isolated Planetary-mass Gravitational Lenses be Measured by Terrestrial Parallax?

    NASA Astrophysics Data System (ADS)

    Freeman, M.; Philpott, L. C.; Abe, F.; Albrow, M. D.; Bennett, D. P.; Bond, I. A.; Botzler, C. S.; Bray, J. C.; Cherrie, J. M.; Christie, G. W.; Dionnet, Z.; Gould, A.; Han, C.; Heyrovský, D.; McCormick, J. M.; Moorhouse, D. M.; Muraki, Y.; Natusch, T.; Rattenbury, N. J.; Skowron, J.; Sumi, T.; Suzuki, D.; Tan, T.-G.; Tristram, P. J.; Yock, P. C. M.

    2015-02-01

    Recently Sumi et al. reported evidence for a large population of planetary-mass objects (PMOs) that are either unbound or orbit host stars in orbits >=10 AU. Their result was deduced from the statistical distribution of durations of gravitational microlensing events observed by the MOA collaboration during 2006 and 2007. Here we study the feasibility of measuring the mass of an individual PMO through microlensing by examining a particular event, MOA-2011-BLG-274. This event was unusual as the duration was short, the magnification high, the source-size effect large, and the angular Einstein radius small. Also, it was intensively monitored from widely separated locations under clear skies at low air masses. Choi et al. concluded that the lens of the event may have been a PMO but they did not attempt a measurement of its mass. We report here a re-analysis of the event using re-reduced data. We confirm the results of Choi et al. and attempt a measurement of the mass and distance of the lens using the terrestrial parallax effect. Evidence for terrestrial parallax is found at a 3σ level of confidence. The best fit to the data yields the mass and distance of the lens as 0.80 ± 0.30 M J and 0.80 ± 0.25 kpc respectively. We exclude a host star to the lens out to a separation ~40 AU. Drawing on our analysis of MOA-2011-BLG-274 we propose observational strategies for future microlensing surveys to yield sharper results on PMOs including those down to super-Earth mass.

  10. Tug-of-war and the infinity Laplacian

    NASA Astrophysics Data System (ADS)

    Peres, Yuval; Schramm, Oded; Sheffield, Scott; Wilson, David B.

    2009-01-01

    We prove that every bounded Lipschitz function F on a subset Y of a length space X admits a tautest extension to X , i.e., a unique Lipschitz extension u:X rightarrow {R} for which operatorname{Lip}_U u =operatorname{Lip}_{partial U} u for all open U subset Xsetminus Y . This was previously known only for bounded domains in {R}^n , in which case u is infinity harmonic; that is, a viscosity solution to Δ_infty u = 0 , where Δ_infty u = \\vertnabla u\\vert^{-2} sum_{i,j} u_{x_i} u_{x_ix_j} u_{x_j}. We also prove the first general uniqueness results for Δ_{infty} u = g on bounded subsets of {R}^n (when g is uniformly continuous and bounded away from 0) and analogous results for bounded length spaces. The proofs rely on a new game-theoretic description of u . Let u^\\varepsilon(x) be the value of the following two-player zero-sum game, called tug-of-war: fix x_0=xin X setminus Y . At the k{^{{th}}} turn, the players toss a coin and the winner chooses an x_k with d(x_k, x_{k-1})< \\varepsilon . The game ends when x_k in Y , and player I's payoff is F(x_k) - frac{\\varepsilon^2}{2}sum_{i=0}^{k-1} g(x_i) . We show that Vert u^\\varepsilon- uVert _{infty} to 0 . Even for bounded domains in {R}^n , the game theoretic description of infinity harmonic functions yields new intuition and estimates; for instance, we prove power law bounds for infinity harmonic functions in the unit disk with boundary values supported in a δ -neighborhood of a Cantor set on the unit circle.

  11. Behavior of a Moist Kelvin Wave Packet with Nonlinear Heating.

    NASA Astrophysics Data System (ADS)

    Wang, Bin; Xue, Yan

    1992-04-01

    The effects of nonlinear (positive only or conditional) heating on moist Kelvin waves are examined with a simple equatorial zonal-plane model describing the gravest baroclinic mode.The unstable perturbation subject to nonlinear beating emerges as a wave packet. A typical amplifying, eastward-moving wave packet is characterized by an asymmetric structure: 1) the ascending branch (wet region) is much narrower than the two descending ones (dry regions); and 2) the circulation cell to the east of the wet region center is smaller and stronger than its counterpart to the west of the center. The wet-dry asymmetry is primarily caused by the nonlinear beating effect, while the east-west asymmetry is a result of the movement of the wave packet relative to mean flow. The existence of Newtonian cooling and Rayleigh friction enhances the structural asymmetries.The unstable wave packet is characterized by two zonal length scales: the ascending branch length (ABL) and total circulation extent (TCE). For a given basic state, the growth rate of a wave packet increases with decreasing ABL or TCE. However, up to a moderate growth rate (order of day1) the energy spectra of all wave packets are dominated by zonal wavenumber one regardless of ABL size. In particular, the slowly growing (low frequency) wave packets normally exhibit TCEs of planetary scale and ABLs of synoptic scale.Observed equatorial intraseasonal disturbances often display a narrow convection region in between two much broader dry regions and a total circulation of planetary scale. These structure and scale characteristics are caused by the effects of nonlinear heating and the cyclic geometry of the equator. It is argued that the unstable disturbance found in numerical experiments (e.g., Lau and Peng; Hayashi and Sumi) is a manifestation of the nonlinear wave packet.

  12. A case study on toxicological aspects of the pest and disease control in the production of the high-quality raspberry (Rubus idaeus L.).

    PubMed

    Sadło, Stanisław; Szpyrka, Ewa; Piechowicz, Bartosz; Grodzicki, Przemysław

    2015-01-01

    The field studies on the residue levels of the fungicides and insecticides used in commercial raspberry (Rubus idaeus L.) plantation have been performed. Starting on the first day of harvesting (on June 19), 20 laboratory samples of fruit, 10 laboratory samples of leaves and 4 samples of soil were analyzed and the residue levels were compared to the Maximum Residue Limits (MRL) and Acceptable Daily Intakes (ADI). All analyses were carried out using extraction method and gas chromatography technique. Esfenwalerate (Sumi-alpha 050 EC) and beta-cyfluthrin (Bulldock 025 EC), the insecticides belonging to the group of synthetic pyrethroids, were not found in harvested ripe fruits, while cypermethrin residues (Cyperkill 25 EC) applied on May 24, 25 days later was still found on low levels in fruits (0.026 mg kg(-1)) and in leaves (2.58 mg kg(-1)). In turn, residues of chlorpyrifos (Dursban 480 EC), applied to the soil on May 15 against the cockchafers Melolontha melolontha and Otiorhynchus sp., were found at the level 0.004 mg kg(-1). The content of pesticides in ripe fruits depended mainly on the dose and on the time that has elapsed from the date of their application and were as follows: boscalid -0.950, pyrimethanil -0.917, pyraclostrobin -0.253 cypermethrin -0.026 and chlorpyrifos -0.004 mg kg(-1) while in leaves: boscalid -30.64, pyrimethanil -8.13, pyraclostrobin -15.82, cypermethrin -2.58 and chlorpyrifos -0.15 mg kg(-1). The highest average daily intake was in the case of boscalid, and in fruits and leaves reached the levels 0.205 and 6.63, in total 0.33% and 12.18% of ADI, respectively. PMID:25421623

  13. CAN THE MASSES OF ISOLATED PLANETARY-MASS GRAVITATIONAL LENSES BE MEASURED BY TERRESTRIAL PARALLAX?

    SciTech Connect

    Freeman, M.; Botzler, C. S.; Bray, J. C.; Cherrie, J. M.; Rattenbury, N. J.; Philpott, L. C.; Abe, F.; Muraki, Y.; Albrow, M. D.; Bennett, D. P.; Bond, I. A.; Christie, G. W.; Natusch, T.; Dionnet, Z.; Gould, A.; Han, C.; Heyrovský, D.; McCormick, J. M.; Skowron, J.; and others

    2015-02-01

    Recently Sumi et al. reported evidence for a large population of planetary-mass objects (PMOs) that are either unbound or orbit host stars in orbits ≥10 AU. Their result was deduced from the statistical distribution of durations of gravitational microlensing events observed by the MOA collaboration during 2006 and 2007. Here we study the feasibility of measuring the mass of an individual PMO through microlensing by examining a particular event, MOA-2011-BLG-274. This event was unusual as the duration was short, the magnification high, the source-size effect large, and the angular Einstein radius small. Also, it was intensively monitored from widely separated locations under clear skies at low air masses. Choi et al. concluded that the lens of the event may have been a PMO but they did not attempt a measurement of its mass. We report here a re-analysis of the event using re-reduced data. We confirm the results of Choi et al. and attempt a measurement of the mass and distance of the lens using the terrestrial parallax effect. Evidence for terrestrial parallax is found at a 3σ level of confidence. The best fit to the data yields the mass and distance of the lens as 0.80 ± 0.30 M {sub J} and 0.80 ± 0.25 kpc respectively. We exclude a host star to the lens out to a separation ∼40 AU. Drawing on our analysis of MOA-2011-BLG-274 we propose observational strategies for future microlensing surveys to yield sharper results on PMOs including those down to super-Earth mass.

  14. Protein dynamics control of electron transfer in photosynthetic reaction centers from Rps. sulfoviridis.

    PubMed

    Medvedev, E S; Kotelnikov, A I; Barinov, A V; Psikha, B L; Ortega, J M; Popović, D M; Stuchebrukhov, A A

    2008-03-13

    In the cycle of photosynthetic reaction centers, the initially oxidized special pair of bacteriochlorophyll molecules is subsequently reduced by an electron transferred over a chain of four hemes of the complex. Here, we examine the kinetics of electron transfer between the proximal heme c-559 of the chain and the oxidized special pair in the reaction center from Rps. sulfoviridis in the range of temperatures from 294 to 40 K. The experimental data were obtained for three redox states of the reaction center, in which one, two, or three nearest hemes of the chain are reduced prior to special pair oxidation. The experimental kinetic data are analyzed in terms of a Sumi-Marcus-type model developed in our previous paper,1 in which similar measurements were reported on the reaction centers from Rps. viridis. The model allows us to establish a connection between the observed nonexponential electron-transfer kinetics and the local structural relaxation dynamics of the reaction center protein on the microsecond time scale. The activation energy for relaxation dynamics of the protein medium has been found to be around 0.1 eV for all three redox states, which is in contrast to a value around 0.4-0.6 eV in Rps. viridis.1 The possible nature of the difference between the reaction centers from Rps. viridis and Rps. sulfoviridis, which are believed to be very similar, is discussed. The role of the protein glass transition at low temperatures and that of internal water molecules in the process are analyzed. PMID:18284231

  15. Characterisation of intact proteins in aquatic samples from the Florida Everglades

    NASA Astrophysics Data System (ADS)

    Jones, V.; Ruddell, C. J.; Wainwright, G.; Rees, H. H.; Jaffe, R.; Penkman, K. E. H.; Collins, C. J.; Wolff, G. A.

    2003-04-01

    environments compared to the open ocean. References Karl, D., Bidigare, R.R., Letelier, R.M., 2001. Long-term changes in plankton community structure and productivity in the North Pacific Subtropical Gyre: The domain shift hypothesis. Deep-Sea Research II, 48: 1449-1470. McCarthy, M.D., Hedges, J.J. Benner, R., 1998. Major bacterial contribution to marine dissolved organic nitrogen. Science, 281: 231-234. Tanoue E., Sumie, N., Kamo, M., Tsurita, A, 1995. Bacterial membranes: Possible sources of major dissolved protein in seawater. Geochimica and Cosmochimica Acta, 59: 2643-2648

  16. Induced Seismicity: Balancing the Scientific Process With the Need for Rapid Communication of Evolving Seismic Hazards

    NASA Astrophysics Data System (ADS)

    Cochran, E. S.; Ellsworth, W. L.; Llenos, A. L.; Rubinstein, J. L.

    2014-12-01

    In this presentation, we outline the USGS response to dramatically increased earthquake activity in the central and eastern US, with a focus on Oklahoma. Using the November 2011 Prague, OK earthquake sequence as an example, we describe the tensions between the need to conduct thorough scientific investigations while providing timely information to local, state, and federal government agencies, and the public. In the early morning hours of November 5, 2011 a M4.8 earthquake struck near the town of Prague, Oklahoma and was followed by a M5.6 earthquake just over 20 hours later. The mainshock was widely felt across the central US, causing damage to homes close to the epicenter and injuring at least 2 people. Within hours of the initial event several portable instruments were installed and following the mainshock a larger seismic deployment was mounted (Keranen et al., 2013). A sizeable earthquake in the central or eastern US is always of scientific interest due to the dearth of seismic data available for assessing seismic hazard. The Prague sequence garnered especially strong scientific and public interest when a link between the sequence and injection of wastewater at several local deep wells was postulated. Therefore, there was a need to provide immediate information as it became available. However, in the first few days to months it was impossible to confidently confirm or refute whether the seismicity was linked to injection, but it was known that the foreshock occurred close to several deep injection wells and many of the events were shallow; thus, the sequence warranted further study. Over the course of the next few years, several studies built the case that the Prague sequence was likely induced by wastewater injection (Keranen et al., 2013; Sumy et al., 2014; McGarr, 2014) and additional studies suggested that the changes in seismicity throughout Oklahoma were not due to natural variations in seismicity rates (Llenos and Michael, 2013; Ellsworth, 2013). These

  17. Constrained Path Monte Carlo and Its Application to the 2-D Hubbard Model

    NASA Astrophysics Data System (ADS)

    Zhang, Shiwei

    1996-03-01

    A recently proposed^1 quantum Monte Carlo (MC) simulation algorithm will be described for studying the ground-state (T=0K) properties of many-fermion systems. The method relies on the usual Hubbard-Stratonovich transformation. It consists of branching random walks in an over-complete basis space of Slater determinants. Asymptotically, the random walks produce determinants |φ_i> non-orthogonal to each other that collectively represent the ground-state wave function in an MC sense: |Ψ_0>=sumi |φ_i>. This reformulation combines important advantages of existing ground-state MC methods and provides an algorithm closely linked to traditional quantum chemistry approaches. In cases free of the fermion MC ``sign'' problem (e.g., half-filled or negative U Hubbard model), the formulation is exact, as is the standard projector MC^2. In cases with the sign problem, we constrain^3 each |φ_i> in the random walk to maintain a positive overlap with a trial wave function |ψ_T>. This constraint eliminates the exponential scaling of CPU time with system size. The computed ground-state energy is an upper bound. The method becomes exact if |ψ_T> is exact. Test results on the two-dimensional Hubbard model show that, even with a simple |ψ_T> such as a free-electron or an unrestricted Hartree-Fock wave function, the method yields very accurate energy and correlation function values when compared with available data from exact diagonalization and quantum MC. Results will be presented on correlation functions (e.g., pair-field) for up to 16× 16 lattices, at various electron fillings and interaction strengths. Work supported in part by the Department of Energy's High Performance Computing and Communication Program at Los Alamos National Laboratory, and at OSU by DOE-Basic Energy Sciences, Division of Materials Sciences. ^1 Shiwei Zhang, J. Carlson, and J. E. Gubernatis, Phys. Rev. Lett. 74, 3652 (1995). ^2 R. Blankenbecler, D. J. Scalapino, and R. L. Sugar, Phys. Rev. D 24, 2278 (1981

  18. Time-reversal imaging techniques applied to tremor waveforms near Cholame, California to locate tectonic tremor

    NASA Astrophysics Data System (ADS)

    Horstmann, T.; Harrington, R. M.; Cochran, E. S.

    2012-12-01

    Thurber et al. (2006) interpolated to a grid spacing of 50 m. Such grid spacing corresponds to frequencies of up to 8 Hz, which is suitable to calculate the wave propagation of tremor. Our dataset contains continuous broadband data from 13 STS-2 seismometers deployed from May 2010 to July 2011 along the Cholame segment of the San Andreas Fault as well as data from the HRSN and PBO networks. Initial synthetic results from tests on a 2D plane using a line of 15 receivers suggest that we are able to recover accurate event locations to within 100 m horizontally and 300 m depth. We conduct additional synthetic tests to determine the influence of signal-to-noise ratio, number of stations used, and the uncertainty in the velocity model on the location result by adding noise to the seismograms and perturbations to the velocity model. Preliminary results show accurate show location results to within 400 m with a median signal-to-noise ratio of 3.5 and 5% perturbations in the velocity model. The next steps will entail performing the synthetic tests on the 3D velocity model, and applying the method to tremor waveforms. Furthermore, we will determine the spatial and temporal distribution of the source locations and compare our results to those by Sumy and others.

  19. Electronic structure and magnetism in some transition metal nitrides: Manganese-doped scandium nitride, dilute magnetic semiconductor and chromium nitride, Mott insulator

    NASA Astrophysics Data System (ADS)

    Herwadkar, Aditi A.

    The thesis presented here deal with calculations of electronic and magnetic properties of transition metal based materials. Electronic structure of Mn-doped ScN: a possible new magnetic semiconductor. We performed fully relaxed full-potential linear muffin-tin orbital method calculations of Mn-doped ScN using a supercell approach. We found that a t2g like defect level exists in the gap and gives rise to a magnetic moment between 2 an 3 muB. Calculations for 64 atom cells with two Mn in 1st-4th neighbor positions indicated a preference for ferromagnetic coupling. By mapping the energy differences on a Heisenberg Hamiltonian and assuming interactions with distant atoms except those in the adjacent unit cells are zero, we extracted the exchange interactions, which were found to be rather large and indicate a Curie temperature above room temperature even for only 3% Mn. Calculations of the miscibility indicated only 1% equilibrium miscibility at typical growth temperatures. However, non-equilibrium growth techniques have shown that in practice mixed alloys up to 26% Mn can be grown. We also studied the effect of n-type doping. Unexpectedly, Mn defects in the negative charge state still have an even larger magnetic moment with an increase in the eg state contribution. Subsequently, we carried out further calculations of the exchange interactions using non-collinear magnetic configurations in which the spin is slowly rotated. It was found that the previous calculations overestimate the J 0 = sumi J0i, i.e. the sum of all interactions connected to a given site, by about 30%. Further studies using the Liechtenstein linear response approach show that the latter is a sum over many long range interactions extending significantly beyond the range of the cells we had used. In this approach the long range interactions are obtained by Fourier transform of the Jij (k) for a mesh of k-points in the supercell. The nearest neighbor interactions are found to be an order of magnitude

  20. Safe Vibrations of Spilling Basin Explosions at "Gotvand Olya Dam" Using Artificial Neural Network

    NASA Astrophysics Data System (ADS)

    Bakhshandeh Amnieh, Hassan; Bahadori, Moein

    2014-12-01

    Ground vibration is an undesirable outcome of an explosion which can have destructive effects on the surrounding environment and structures. Peak Particle Velocity (PPV) is a determining factor in evaluation of the damage caused by an explosion. To predict the ground vibration caused by blasting at the Gotvand Olya Dam (GOD) spilling basin, thirty 3-component records (totally 90) from 19 blasts were obtained using 3 VIBROLOC seismographs. Minimum and the maximum distance from the center of the exploding block to the recording station were set to be 11 and 244 meters, respectively. To evaluate allowable safe vibration and determining the permissible explosive charge weight, Artificial Neural Networks (ANN) was employed with Back Propagation (BP) and 3 hidden layers. The mean square error and the correlation coefficient of the network in this study were found to be 1.95 and 0.995, respectively, which compared to those obtained from the known empirical correlations, indicating substantially more accurate prediction. Considering the network high accuracy and precision in predicting vibrations caused by such blasting operations, the nearest distance from the center of the exploding block at this study was 11 m, and considering the standard allowable vibration of 120 mm/sec for heavy concrete structures, the maximum permissible explosive weight per delay was estimated to be 47.00 Kg. These results could be employed in subsequent safer blasting operation designs. Wibracje gruntu to niepożądany skutek prowadzenia prac strzałowych, które mogą negatywnie wpływać na otaczające środowisko oraz znajdujące się w sąsiedztwie budowle. Głównym wskaźnikiem używanym przy określaniu szkód spowodowanych przez wybuchy jest wskaźnik maksymalnej prędkości cząstek (PPV). Przy prognozowaniu wibracji terenu wskutek prac strzałowych prowadzonych na tamie Gotvand Olya i w zbiorniku zbadano zapisy 3-składnikowych prędkości ( w sumie 90 zapisów) z 13 wybuch

  1. Nonadditive entropy: The concept and its use

    NASA Astrophysics Data System (ADS)

    Tsallis, C.

    2009-06-01

    The thermodynamical concept of entropy was introduced by Clausius in 1865 in order to construct the exact differential dS = δ Q/ T , where δ Q is the heat transfer and the absolute temperature T its integrating factor. A few years later, in the period 1872-1877, it was shown by Boltzmann that this quantity can be expressed in terms of the probabilities associated with the microscopic configurations of the system. We refer to this fundamental connection as the Boltzmann-Gibbs (BG) entropy, namely (in its discrete form) ensuremath S_{BG}=-ksum_{i=1}^W p_i ln p_i , where k is the Boltzmann constant, and { p i} the probabilities corresponding to the W microscopic configurations (hence ∑W i=1 p i = 1 . This entropic form, further discussed by Gibbs, von Neumann and Shannon, and constituting the basis of the celebrated BG statistical mechanics, is additive. Indeed, if we consider a system composed by any two probabilistically independent subsystems A and B ( i.e., ensuremath p_{ij}^{A+B}=p_i^A p_j^B, forall(i,j) , we verify that ensuremath S_{BG}(A+B)=S_{BG}(A)+S_{BG}(B) . If a system is constituted by N equal elements which are either independent or quasi-independent ( i.e., not too strongly correlated, in some specific nonlocal sense), this additivity guarantees SBG to be extensive in the thermodynamical sense, i.e., that ensuremath S_{BG}(N) ∝ N in the N ≫ 1 limit. If, on the contrary, the correlations between the N elements are strong enough, then the extensivity of SBG is lost, being therefore incompatible with classical thermodynamics. In such a case, the many and precious relations described in textbooks of thermodynamics become invalid. Along a line which will be shown to overcome this difficulty, and which consistently enables the generalization of BG statistical mechanics, it was proposed in 1988 the entropy ensuremath S_q=k [1-sum_{i=1}^W p_i^q]/(q-1) (qin{R}; S_1=S_{BG}) . In the context of cybernetics and information theory, this and similar forms

  2. Ionospheric parameter analysis techniques and anomaly identification in periods of ionospheric perturbations

    NASA Astrophysics Data System (ADS)

    Mandrikova, Oksana; Polozov, Yury; Fetisova Glushkova, Nadejda; Shevtsov, Boris

    In the present paper we suggest intellectual techniques intended for the analysis of ionospheric parameters. These techniques are directed at studying dynamic processes in the "magnetosphere-ionosphere" system during perturbations. Using the combination of the wavelet transform and neural networks, the authors have developed a technique of approximating the time variation of ionospheric parameters. This technique allows us to make data predictions and detect anomalies in the ionosphere. Multiscale component approximations of the critical frequency of the ionosphere layer F2 were constructed. These approximations can be presented in the following form: begin{center} c_{l,k+m} (t) = varphi_m(3) Bigl (sum_i omega(3_{mi}) varphi_i(2) Bigl (sum_j omega(2_{ij}) varphi_j(1) Bigl (sum_k omega(1_{jk}) c_{l,k} (t) Bigr ) Bigr ) Bigr ) , where c_{l,k} = bigl < f , Psi_{l,k} bigr > ; Psi_{l,k} (t) = 2(l/2) Psi (2(l) t - k) is the wavelet basis; omega(1_{jk}) are the weighting coefficients of the neuron j of the network input layer; omega(2_{ij}) are the weighting coefficients of the neuron i of the network hidden layer; omega(3_{mi}) are the weighting coefficients of the neuron m of the network output layer; varphi(1_j) (z) = varphi(2_i) (z) = (1)/(1+exp(-z))) ; varphi(3_m) (z) = x*z+y . The coefficients c_{l,k} can be found as a result of transforming the original function f into the space with the scale l . In order to obtain the approximations of the time variation of data, neural networks can be united in groups. In the paper we have suggested a multicomponent time variation model of ionospheric parameters, which makes it possible to perform the analysis of the ionospheric dynamic mode, receive predictions about parameter variations, and detect anomalies in periods of perturbations. The multicomponent model also allows us to fill missing values in critical frequency data taking into account diurnal and seasonal variations. Identification of the model is based on combining

  3. Why should we pay more for layout designers?

    NASA Astrophysics Data System (ADS)

    Khan, Samee U.

    2003-12-01

    ,G2j^2,....,Gmj^2 6. Compute I, (Mij) in each Gij^2 7. Compute Si=si(u)|u belongs to Mij 8. Find the minimum index i such that w(Si)<= w(D) 9. Return Sj 10. Compute G'=min Mij belongs V [max si sum{i=0}^{|Sj|] 11. Return G' Theorem 2 The PNL algorithm is complete and will identify a solution, if there exists one. Proof (Trivial and not included due to space) Theorem 3 The PNL algorithm has a lower bound of 4-approximation to the optimal algorithm. Proof (Not included due to space, but the basic argument, is due to the fact that picking a node v with 2-epsilon in G^2, would required the neighbors to be picked in G^4, thus the PNL is no better than 4-epsilon, where epsilon >0) Experiments We made some initial experiments, which are showing promissing results with savings in fiber, equipment cost, due to space, and inital phase of the experiments, we are not including the results here. P.S. My appologies for exceeding the text limit. There is much more detail to the formal proof, I hope the idea is still conveyed. There are also 2 figures which will be faxed.