Science.gov

Sample records for multi level inverter

  1. Characteristics Comparison of High-Frequency Multi-Level Inverter Connected with Filter Inverters

    NASA Astrophysics Data System (ADS)

    Iwaya, Kazuki; Noguchi, Toshihiko

    This paper presents characteristics comparison of a high-frequency multi-level inverter connected with small capacity filter inverters. In general, PWM inverters require a low-pass filter in order to reduce switching harmonics. However, in the high-frequency systems such as class D power amplifiers, the cut-off frequency of the low-pass filter must set at high frequency. Thus, harmonic distortion of the output voltage harmfully enlarges. Increasing the number of output voltage levels is effective to reduce the harmonic distortion of the output voltage and the low-pass filter size. The proposed systems consist of a 5-level inverter and several cascade-connected low-voltage full bridge inverters without any external DC power sources for filtering the output voltage. The 5-level inverter generates a stepwise waveform with 5-level voltage, and the low voltage filter inverter superimposes harmonic components to compensate for the voltage waveform distortion. Therefore, the proposed system can reduce its total switching loss and can increase the number of the output voltage levels. In this paper, effectiveness of the proposed systems is verified through several experiments.

  2. A single-phase multi-level D-STATCOM inverter using modular multi-level converter (MMC) topology for renewable energy sources

    NASA Astrophysics Data System (ADS)

    Sotoodeh, Pedram

    This dissertation presents the design of a novel multi-level inverter with FACTS capability for small to mid-size (10-20kW) permanent-magnet wind installations using modular multi-level converter (MMC) topology. The aim of the work is to design a new type of inverter with D-STATCOM option to provide utilities with more control on active and reactive power transfer of distribution lines. The inverter is placed between the renewable energy source, specifically a wind turbine, and the distribution grid in order to fix the power factor of the grid at a target value, regardless of wind speed, by regulating active and reactive power required by the grid. The inverter is capable of controlling active and reactive power by controlling the phase angle and modulation index, respectively. The unique contribution of the proposed work is to combine the two concepts of inverter and D-STATCOM using a novel voltage source converter (VSC) multi-level topology in a single unit without additional cost. Simulations of the proposed inverter, with 5 and 11 levels, have been conducted in MATLAB/Simulink for two systems including 20 kW/kVAR and 250 W/VAR. To validate the simulation results, a scaled version (250 kW/kVAR) of the proposed inverter with 5 and 11 levels has been built and tested in the laboratory. Experimental results show that the reduced-scale 5- and 11-level inverter is able to fix PF of the grid as well as being compatible with IEEE standards. Furthermore, total cost of the prototype models, which is one of the major objectives of this research, is comparable with market prices.

  3. Fault-tolerant three-level inverter

    DOEpatents

    Edwards, John; Xu, Longya; Bhargava, Brij B.

    2006-12-05

    A method for driving a neutral point clamped three-level inverter is provided. In one exemplary embodiment, DC current is received at a neutral point-clamped three-level inverter. The inverter has a plurality of nodes including first, second and third output nodes. The inverter also has a plurality of switches. Faults are checked for in the inverter and predetermined switches are automatically activated responsive to a detected fault such that three-phase electrical power is provided at the output nodes.

  4. High performance control of a three-level IGBT inverter fed AC drive

    SciTech Connect

    Zhang, J.

    1995-12-31

    Three-level PWM inverters have been increasingly employed in industry and traction applications where high power and efficiency energy conversions are required. This paper presents a high performance control of a cage induction motor drive fed by a 100 Hp three-level IGBT inverter operating at a low switching frequency. A practical math model of the drive control system is established to aid in the control design to improve the system stability, dynamic performance and robustness over a wide speed range. The modeling and the simulation in Matlab/Simulink facilitate the self-tuning of the regulators in the multi-loop systems. The field oriented control and three-level space-vector modulation together with the drive protection and diagnostics are implemented in software based on a DSP TMS320C31. Experimental results based on the IGBT inverter prototype are given to verify the design and performance. Test results in motor common-mode voltage reduction and inverter neutral-point potential control re also briefly presented.

  5. Advanced Inverter Functions to Support High Levels of Distributed Solar: Policy and Regulatory Considerations (Brochure)

    SciTech Connect

    Not Available

    2014-11-01

    This paper explains how advanced inverter functions (sometimes called 'smart inverters') contribute to the integration of high levels of solar PV generation onto the electrical grid and covers the contributions of advanced functions to maintaining grid stability. Policy and regulatory considerations associated with the deployment of advanced inverter functions are also introduced.

  6. Extreme Cost Reductions with Multi-Megawatt Centralized Inverter Systems

    SciTech Connect

    Schwabe, Ulrich; Fishman, Oleg

    2015-03-20

    The objective of this project was to fully develop, demonstrate, and commercialize a new type of utility scale PV system. Based on patented technology, this includes the development of a truly centralized inverter system with capacities up to 100MW, and a high voltage, distributed harvesting approach. This system promises to greatly impact both the energy yield from large scale PV systems by reducing losses and increasing yield from mismatched arrays, as well as reduce overall system costs through very cost effective conversion and BOS cost reductions enabled by higher voltage operation.

  7. Applications of cascade multilevel inverters.

    PubMed

    Peng, Fang-zen; Qian, Zhao-ming

    2003-01-01

    Cascade multilevel inverters have been developed for electric utility applications. A cascade M-level inverter consists of (M-1)/2 H-bridges in which each bridge's dc voltage is supported by its own dc capacitor. The new inverter can: (1) generate almost sinusoidal waveform voltage while only switching one time per fundamental cycle; (2) dispense with multi-pulse inverters' transformers used in conventional utility interfaces and static var compensators; (3) enables direct parallel or series transformer-less connection to medium- and high-voltage power systems. In short, the cascade inverter is much more efficient and suitable for utility applications than traditional multi-pulse and pulse width modulation (PWM) inverters. The authors have experimentally demonstrated the superiority of the new inverter for power supply, (hybrid) electric vehicle (EV) motor drive, reactive power (var) and harmonic compensation. This paper summarizes the features, feasibility, and control schemes of the cascade inverter for utility applications including utility interface of renewable energy, voltage regulation, var compensation, and harmonic filtering in power systems. Analytical, simulated, and experimental results demonstrated the superiority of the new inverters. PMID:14566981

  8. Fundamental Frequency Switching Control of Seven-Level Hybrid Cascaded H-bridge Multilevel Inverter

    SciTech Connect

    Du, Zhong; Chiasson, John N; Ozpineci, Burak; Tolbert, Leon M

    2009-01-01

    This paper presents a cascaded H-bridge multilevel inverter that can be implemented using only a single dc power source and capacitors. Standard cascaded multilevel inverters require n dc sources for 2n + 1 levels. Without requiring transformers, the scheme proposed here allows the use of a single dc power source (e.g., a battery or a fuel cell stack) with the remaining n-1 dc sources being capacitors, which is referred to as hybrid cascaded H-bridge multilevel inverter (HCMLI) in this paper. It is shown that the inverter can simultaneously maintain the dc voltage level of the capacitors and choose a fundamental frequency switching pattern to produce a nearly sinusoidal output. HCMLI using only a single dc source for each phase is promising for high-power motor drive applications as it significantly decreases the number of required dc power supplies, provides high-quality output power due to its high number of output levels, and results in high conversion efficiency and low thermal stress as it uses a fundamental frequency switching scheme. This paper mainly discusses control of seven-level HCMLI with fundamental frequency switching control and how its modulation index range can be extended using triplen harmonic compensation.

  9. Cylindrical Inverted Multi-Cell (CIM) Thermionic Converter for Solar Power and Propulsion Systems

    NASA Astrophysics Data System (ADS)

    Martinez, Martin R.; Izhvanov, Oleg; Robertson, Bill; Clark, Paul N.; Streckert, Holger H.; Desplat, Jean-Louis

    2005-02-01

    Design and fabrication of a novel four cell cylindrically inverted multi-cell (CIM) solar thermionic converter for space power applications is in progress. When heated externally, the converter (8 cm diameter and 35 cm long) is capable of producing up to 492 W of electric power. The emitters operate at 2000 K while the collectors operate at 1050 K. Key components include four polycrystalline rhenium (Re) emitters, a cesium (Cs) containment vessel, and a collector trilayer. The emitters and containment vessel are both made from Re tubing. Hot Isostatic press (HIP) processing is used to produce the collector trilayer which is made up of a niobium alloy (Nb-1%Zr) base tube, plasma sprayed aluminum oxide insulation layer, and a niobium collector tube. After machining the Re emitters are brazed to the Nb collectors. The purpose of this paper is to describe the design and fabrication of the four cell CIM which will be tested at General Atomics (GA).

  10. Vertically stacked multi-heterostructures of layered materials for logic transistors and complementary inverters.

    PubMed

    Yu, Woo Jong; Li, Zheng; Zhou, Hailong; Chen, Yu; Wang, Yang; Huang, Yu; Duan, Xiangfeng

    2013-03-01

    Graphene has attracted considerable interest for future electronics, but the absence of a bandgap limits its direct applicability in transistors and logic devices. Recently, other layered materials such as molybdenum disulphide (MoS(2)) have been investigated to address this challenge. Here, we report the vertical integration of multi-heterostructures of layered materials for the fabrication of a new generation of vertical field-effect transistors (VFETs) with a room temperature on-off ratio > 10(3) and a high current density of up to 5,000 A cm(-2). An n-channel VFET is created by sandwiching few-layer MoS(2) as the semiconducting channel between a monolayer graphene sheet and a metal thin film. This approach offers a general strategy for the vertical integration of p- and n-channel transistors for high-performance logic applications. As an example, we demonstrate a complementary inverter with a larger-than-unity voltage gain by vertically stacking graphene, Bi(2)Sr(2)Co(2)O(8) (p-channel), graphene, MoS(2) (n-channel) and a metal thin film in sequence. The ability to simultaneously achieve a high on-off ratio, a high current density and a logic function in such vertically stacked multi-heterostructures can open up possibilities for three-dimensional integration in future electronics. PMID:23241535

  11. Vertically stacked multi-heterostructures of layered materials for logic transistors and complementary inverters

    NASA Astrophysics Data System (ADS)

    Yu, Woo Jong; Li, Zheng; Zhou, Hailong; Chen, Yu; Wang, Yang; Huang, Yu; Duan, Xiangfeng

    2013-03-01

    Graphene has attracted considerable interest for future electronics, but the absence of a bandgap limits its direct applicability in transistors and logic devices. Recently, other layered materials such as molybdenum disulphide (MoS2) have been investigated to address this challenge. Here, we report the vertical integration of multi-heterostructures of layered materials for the fabrication of a new generation of vertical field-effect transistors (VFETs) with a room temperature on-off ratio > 103 and a high current density of up to 5,000?A?cm-2. An n-channel VFET is created by sandwiching few-layer MoS2 as the semiconducting channel between a monolayer graphene sheet and a metal thin film. This approach offers a general strategy for the vertical integration of p- and n-channel transistors for high-performance logic applications. As an example, we demonstrate a complementary inverter with a larger-than-unity voltage gain by vertically stacking graphene, Bi2Sr2Co2O8 (p-channel), graphene, MoS2 (n-channel) and a metal thin film in sequence. The ability to simultaneously achieve a high on-off ratio, a high current density and a logic function in such vertically stacked multi-heterostructures can open up possibilities for three-dimensional integration in future electronics.

  12. Superradiant emission from a partially inverted slab of two-level atoms

    NASA Astrophysics Data System (ADS)

    Manassah, Jamal T.

    2014-06-01

    Using the eigenmodes of the 1-D Lienard-Wiechert Green's function, I compute the superradiant emission from an initially partially inverted slab of two-level atoms. I find that in regime I, (T=0)>nmax, there is no superradiant emission (where n(T=0)=n(T=0)-n(T=0)); in regime II, nmax>n(T=0)>ncrit, there is weak intensity superradiance; while in regime III, ncrit>n(T=0)≥-1, superradiant emission share the same features as that of an initially completely inverted system. I show, further, that in regime II, the superradiant emission intensity increases exponentially as a function of -n(T=0), while in regime III, it increases nearly linearly as a function of -n(T=0).

  13. Multi-level modulation codes and multi-stage decoding

    NASA Technical Reports Server (NTRS)

    Lin, Shu

    1990-01-01

    Multi-level method is a powerful technique for constructing bandwidth efficient modulation codes. It allows the construction of modulation codes systematically with arbitrary large minimum squared Euclidean distance from component codes in conjunction with proper bits-to-signal mapping. If the component codes are chosen properly, the resultant modulation code not only has good minimum squared Euclidean distance but is also rich in structural properties such as: linear structure, phase invariant property, and trellis structure. A modulation code with linear structure has invariant distance distribution. Phase invariant property is useful in resolving carrier-phase ambiguity and ensuring rapid carrier-phase resynchronization after temporary loss of synchronization. It the component codes have trellis structure, the resultant multi-level modulation code also has trellis structure. Trellis structure allows decoding of a multi-level modulation code with the soft-decision Viterbi decoding algorithm. Furthermore, the multi-level structure allows decoding of a multi-level modulation code with the multi-stage decoding. This type of decoding reduces the decoding complexity. Multi-stage decoding is not optimum even though the decoding of each component is optimum. Based on the analysis and simulation results, the difference in error performance between the optimum decoding of the overall multi-level modulation code and the suboptimum multi-stage decoding of the code is very little, a fraction of dB loss.

  14. Multi-level block permutation.

    PubMed

    Winkler, Anderson M; Webster, Matthew A; Vidaurre, Diego; Nichols, Thomas E; Smith, Stephen M

    2015-12-01

    Under weak and reasonable assumptions, mainly that data are exchangeable under the null hypothesis, permutation tests can provide exact control of false positives and allow the use of various non-standard statistics. There are, however, various common examples in which global exchangeability can be violated, including paired tests, tests that involve repeated measurements, tests in which subjects are relatives (members of pedigrees) - any dataset with known dependence among observations. In these cases, some permutations, if performed, would create data that would not possess the original dependence structure, and thus, should not be used to construct the reference (null) distribution. To allow permutation inference in such cases, we test the null hypothesis using only a subset of all otherwise possible permutations, i.e., using only the rearrangements of the data that respect exchangeability, thus retaining the original joint distribution unaltered. In a previous study, we defined exchangeability for blocks of data, as opposed to each datum individually, then allowing permutations to happen within block, or the blocks as a whole to be permuted. Here we extend that notion to allow blocks to be nested, in a hierarchical, multi-level definition. We do not explicitly model the degree of dependence between observations, only the lack of independence; the dependence is implicitly accounted for by the hierarchy and by the permutation scheme. The strategy is compatible with heteroscedasticity and variance groups, and can be used with permutations, sign flippings, or both combined. We evaluate the method for various dependence structures, apply it to real data from the Human Connectome Project (HCP) as an example application, show that false positives can be avoided in such cases, and provide a software implementation of the proposed approach. PMID:26074200

  15. Multi-level block permutation

    PubMed Central

    Winkler, Anderson M.; Webster, Matthew A.; Vidaurre, Diego; Nichols, Thomas E.; Smith, Stephen M.

    2015-01-01

    Under weak and reasonable assumptions, mainly that data are exchangeable under the null hypothesis, permutation tests can provide exact control of false positives and allow the use of various non-standard statistics. There are, however, various common examples in which global exchangeability can be violated, including paired tests, tests that involve repeated measurements, tests in which subjects are relatives (members of pedigrees) — any dataset with known dependence among observations. In these cases, some permutations, if performed, would create data that would not possess the original dependence structure, and thus, should not be used to construct the reference (null) distribution. To allow permutation inference in such cases, we test the null hypothesis using only a subset of all otherwise possible permutations, i.e., using only the rearrangements of the data that respect exchangeability, thus retaining the original joint distribution unaltered. In a previous study, we defined exchangeability for blocks of data, as opposed to each datum individually, then allowing permutations to happen within block, or the blocks as a whole to be permuted. Here we extend that notion to allow blocks to be nested, in a hierarchical, multi-level definition. We do not explicitly model the degree of dependence between observations, only the lack of independence; the dependence is implicitly accounted for by the hierarchy and by the permutation scheme. The strategy is compatible with heteroscedasticity and variance groups, and can be used with permutations, sign flippings, or both combined. We evaluate the method for various dependence structures, apply it to real data from the Human Connectome Project (HCP) as an example application, show that false positives can be avoided in such cases, and provide a software implementation of the proposed approach. PMID:26074200

  16. Jupiter's Multi-level Clouds

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Clouds and hazes at various altitudes within the dynamic Jovian atmosphere are revealed by multi-color imaging taken by the Near-Infrared Mapping Spectrometer (NIMS) onboard the Galileo spacecraft. These images were taken during the second orbit (G2) on September 5, 1996 from an early-morning vantage point 2.1 million kilometers (1.3 million miles) above Jupiter. They show the planet's appearance as viewed at various near-infrared wavelengths, with distinct differences due primarily to variations in the altitudes and opacities of the cloud systems. The top left and right images, taken at 1.61 microns and 2.73 microns respectively, show relatively clear views of the deep atmosphere, with clouds down to a level about three times the atmospheric pressure at the Earth's surface.

    By contrast, the middle image in top row, taken at 2.17 microns, shows only the highest altitude clouds and hazes. This wavelength is severely affected by the absorption of light by hydrogen gas, the main constituent of Jupiter's atmosphere. Therefore, only the Great Red Spot, the highest equatorial clouds, a small feature at mid-northern latitudes, and thin, high photochemical polar hazes can be seen. In the lower left image, at 3.01 microns, deeper clouds can be seen dimly against gaseous ammonia and methane absorption. In the lower middle image, at 4.99 microns, the light observed is the planet's own indigenous heat from the deep, warm atmosphere.

    The false color image (lower right) succinctly shows various cloud and haze levels seen in the Jovian atmosphere. This image indicates the temperature and altitude at which the light being observed is produced. Thermally-rich red areas denote high temperatures from photons in the deep atmosphere leaking through minimal cloud cover; green denotes cool temperatures of the tropospheric clouds; blue denotes cold of the upper troposphere and lower stratosphere. The polar regions appear purplish, because small-particle hazes allow leakage and reflectivity, while yellowish regions at temperate latitudes may indicate tropospheric clouds with small particles which also allow leakage. A mix of high and low-altitude aerosols causes the aqua appearance of the Great Red Spot and equatorial region.

    The Jet Propulsion Laboratory manages the Galileo mission for NASA's Office of Space Science, Washington, DC.

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

  17. A Five-Level Cascade Multilevel Inverter Three-Phase Motor Drive Using a Single DC Source

    SciTech Connect

    Chiasson, J. N.

    2006-10-01

    A method is presented showing that a 5-level cascade multilevel inverter for a three-phase permanent magnet sychronous motor drive can be implemented using only a single DC link to supply a standard 3-leg inverter along with three full H-bridges supplied by capacitors. It is shown that the capacitor voltages can be regulated while achieving an output voltage waveform that is 20% greater than that obained using the standard 3-leg inverter alone. Finally conditions are given in terms of the power factor and modulation index that determine when the capacitor voltage can regulated.

  18. Hybrid Pwm Switching Strategy for a Three-Level Inverter Fed Induction Motor Drive with Open-End Windings

    NASA Astrophysics Data System (ADS)

    Srinivas, S.; Ramachandrasekhar, K.

    2010-06-01

    A dual two-level inverter fed induction motor with open-end windings is capable of generating a three-level output voltage. Several, sine-triangle and space vector pulse width modulation (PWM) switching strategies are presented for the dual-inverter scheme either using space-vector or carrier-based implementation. In this paper, a hybrid PWM switching strategy for the dual-inverter scheme is proposed employing sine-triangle PWM (SPWM) and space vector PWM (SVPWM) for the individual inverters. SPWM is theoretically analyzed and space vector based implementation of SPWM is presented using a simple offset-time concept. This is exploited to implement the hybrid PWM switching strategy for the dual two-level inverter. The implementation of the hybrid PWM switching strategy proposed in this paper do not require any look-up tables, the switching is totally automatic obviating the time-consuming task of sector identification. The implementation of the hybrid PWM scheme requires only the three instantaneous phase reference voltages corresponding to the reference space vector. The third harmonic component in the voltage appearing across the motor phase windings in the induction motor is significantly reduced (by 50%) with the use of the proposed hybrid PWM scheme as compared to the use of the PWM scheme presented earlier. Also, the percentage weighted total harmonic distortion (%WTHD) of the output voltage is significantly reduced in the entire range of speed of the induction motor driven by the dual-inverter scheme.

  19. Virtual-Flux Direct Power Control for Mains Connected Three-Level NPC Inverter Systems

    NASA Astrophysics Data System (ADS)

    Serpa, Leonardo A.; Kolar, Johann W.

    This paper proposes a control strategy which extends the Virtual-Flux Direct Power Control traditionally employed for the conventional two-level VSI to a three-level NPC inverter. This topology generates a higher number of output voltage levels, increasing the flexibility for selecting an appropriate voltage vector. The mid-point potential is controlled according to the direction of the mid-point current and the sign of the mid-point voltage deviation. The method is adapted to be used with an LCL output filter, where some undesirable characteristics, such as filter resonance, have to be compensated. Further investigation concerning the dependency of the mid-point voltage with the current phase-shift is given. Theoretical analysis is presented and the performance of the proposed method is verified by simulation.

  20. Advanced Inverter Technology for High Penetration Levels of PV Generation in Distribution Systems

    SciTech Connect

    Schauder, C.

    2014-03-01

    This subcontract report was completed under the auspices of the NREL/SCE High-Penetration Photovoltaic (PV) Integration Project, which is co-funded by the U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) and the California Solar Initiative (CSI) Research, Development, Demonstration, and Deployment (RD&D) program funded by the California Public Utility Commission (CPUC) and managed by Itron. This project is focused on modeling, quantifying, and mitigating the impacts of large utility-scale PV systems (generally 1-5 MW in size) that are interconnected to the distribution system. This report discusses the concerns utilities have when interconnecting large PV systems that interconnect using PV inverters (a specific application of frequency converters). Additionally, a number of capabilities of PV inverters are described that could be implemented to mitigate the distribution system-level impacts of high-penetration PV integration. Finally, the main issues that need to be addressed to ease the interconnection of large PV systems to the distribution system are presented.

  1. Multi-stage decoding of multi-level modulation codes

    NASA Technical Reports Server (NTRS)

    Lin, Shu; Kasami, Tadao; Costello, Daniel J., Jr.

    1991-01-01

    Various types of multi-stage decoding for multi-level modulation codes are investigated. It is shown that if the component codes of a multi-level modulation code and types of decoding at various stages are chosen properly, high spectral efficiency and large coding gain can be achieved with reduced decoding complexity. Particularly, it is shown that the difference in performance between the suboptimum multi-stage soft-decision maximum likelihood decoding of a modulation code and the single-stage optimum soft-decision decoding of the code is very small, only a fraction of dB loss in signal to noise ratio at a bit error rate (BER) of 10(exp -6).

  2. Inverted barometer contributions to recent sea level changes along the northeast coast of North America

    NASA Astrophysics Data System (ADS)

    Piecuch, Christopher G.; Ponte, Rui M.

    2015-07-01

    Regional sea level (SL) changes reflect dynamic and isostatic ocean effects. Recent works have interpreted accelerated and extreme SL changes along the northeast coast of North America primarily in terms of dynamic changes; however, dedicated study of isostatic changes related to surface atmospheric pressure loading—the inverted barometer (IB) effect—has been lacking. This investigation uses five different atmospheric pressure products to analyze the influence of the IB effect on annual mean SL from tide gauge records. The IB effect explains ˜25% of interannual SL variance and accounts for ˜50% of the magnitude of a recent extreme event of SL rise along Atlantic Canada and New England. Estimated IB effects also amount to ˜10-30% of recent multidecadal SL accelerations over the Mid-Atlantic Bight and Southern New England. These findings reiterate the need for careful estimation and removal of isostatic effects for studies of dynamic SL.

  3. How to Invert Multi-Band, Regional Phase Amplitudes for 2-D Attenuation and Source Parameters: Tests Using the USArray

    NASA Astrophysics Data System (ADS)

    Phillips, W. Scott; Mayeda, Kevin M.; Malagnini, Luca

    2014-03-01

    We inverted for laterally varying attenuation, absolute site terms, moments and apparent stress using over 460,000 Lg amplitudes recorded by the USArray for frequencies between 0.5 and 16 Hz. Corner frequencies of Wells, Nevada, aftershocks, obtained by independent analysis of coda spectral ratios, controlled the tradeoff between attenuation and stress, while independently determined moments from St. Louis University and the University of California constrained absolute levels. The quality factor, Q, was low for coastal regions and interior volcanic and tectonic areas, and high for stable regions such as the Great Plains, and Colorado and Columbia Plateaus. Q increased with frequency, and the rate of increase correlated inversely with 1-Hz Q, with highest rates in low- Q tectonic regions, and lowest rates in high- Q stable areas. Moments matched independently determined moments with a scatter of 0.2 NM. Apparent stress ranged from below 0.01 to above 1 MPa, with means of 0.1 MPa for smaller events, and 0.3 MPa for larger events. Stress was observed to be spatially coherent in some areas; for example, stress was lower along the San Andreas fault through central and northern California, and higher in the Walker Lane, and for isolated sequences such as Wells. Variance reduction relative to 1-D models ranged from 50 to 90 % depending on band and inversion method. Parameterizing frequency dependent Q as a power law produced little misfit relative to a collection of independent, multi-band Q models, and performed better than the omega-square source parameterization in that sense. Amplitude residuals showed modest, but regionally coherent patterns that varied from event to event, even between those with similar source mechanisms, indicating a combination of focal mechanism, and near source propagation effects played a role. An exception was the Wells mainshock, which produced dramatic amplitude patterns due to its directivity, and was thus excluded from the inversions. The 2-D Q plus absolute site models can be used for high accuracy, broad area source spectra, magnitude and yield estimation, and, in combination with models for all regional phases, can be used to improve discrimination, in particular for intermediate bands that allow coverage to be extended beyond that available for high frequency P-to-S discriminants.

  4. Anticrossing of Landau levels in HgTe/CdHgTe (013) quantum wells with an inverted band structure

    NASA Astrophysics Data System (ADS)

    Zholudev, M. S.; Teppe, F.; Morozov, S. V.; Orlita, M.; Consejo, C.; Ruffenach, S.; Knap, W.; Gavrilenko, V. I.; Dvoretskii, S. A.; Mikhailov, N. N.

    2015-02-01

    The simultaneous splitting of lines of an interband transition and cyclotron resonance in the conduction band has been detected in the absorption spectra of HgTe/CdHgTe quantum wells with an inverted band structure in quantizing magnetic fields. It has been shown that it is due to the absence of an inversion center in the crystal, which results in the interaction between the lower Landau level of the conduction band and the upper Landau level of the valence band.

  5. Multilevel cascade voltage source inverter with seperate DC sources

    DOEpatents

    Peng, Fang Zheng (Knoxville, TN); Lai, Jih-Sheng (Blacksburg, VA)

    2002-01-01

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

  6. Multilevel cascade voltage source inverter with seperate DC sources

    DOEpatents

    Peng, Fang Zheng; Lai, Jih-Sheng

    2001-04-03

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

  7. Multilevel cascade voltage source inverter with seperate DC sources

    DOEpatents

    Peng, Fang Zheng (Oak Ridge, TN); Lai, Jih-Sheng (Knoxville, TN)

    1997-01-01

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

  8. Multilevel cascade voltage source inverter with separate DC sources

    DOEpatents

    Peng, F.Z.; Lai, J.S.

    1997-06-24

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations. 15 figs.

  9. Multi-level coupled cluster theory

    SciTech Connect

    Myhre, Rolf H.; Koch, Henrik; Sánchez de Merás, Alfredo M. J.

    2014-12-14

    We present a general formalism where different levels of coupled cluster theory can be applied to different parts of the molecular system. The system is partitioned into subsystems by Cholesky decomposition of the one-electron Hartree-Fock density matrix. In this way the system can be divided across chemical bonds without discontinuities arising. The coupled cluster wave function is defined in terms of cluster operators for each part and these are determined from a set of coupled equations. The total wave function fulfills the Pauli-principle across all borders and levels of electron correlation. We develop the associated response theory for this multi-level coupled cluster theory and present proof of principle applications. The formalism is an essential tool in order to obtain size-intensive complexity in the calculation of local molecular properties.

  10. Multi-level coupled cluster theory

    NASA Astrophysics Data System (ADS)

    Myhre, Rolf H.; Snchez de Mers, Alfredo M. J.; Koch, Henrik

    2014-12-01

    We present a general formalism where different levels of coupled cluster theory can be applied to different parts of the molecular system. The system is partitioned into subsystems by Cholesky decomposition of the one-electron Hartree-Fock density matrix. In this way the system can be divided across chemical bonds without discontinuities arising. The coupled cluster wave function is defined in terms of cluster operators for each part and these are determined from a set of coupled equations. The total wave function fulfills the Pauli-principle across all borders and levels of electron correlation. We develop the associated response theory for this multi-level coupled cluster theory and present proof of principle applications. The formalism is an essential tool in order to obtain size-intensive complexity in the calculation of local molecular properties.

  11. Phase-dependent high refractive index without absorption in a four-level inverted-Y atomic system

    NASA Astrophysics Data System (ADS)

    Zeng, Zhi-Qiang; Wang, Yu-Ping; Liu, Fu-Ti; Gao, Zeng-Hui

    2015-01-01

    We consider a closed four-level inverted-Y system in the presence and the absence of a microwave field. It is found that due to the quantum coherence between the two lower levels, either induced by the spontaneous decay or by the microwave field, the refraction - absorption properties of the system can be modulated by controlling the relative phase of the applied fields in both driven ways. In particular, by properly setting the values of the relative phase, the desirable high index of refraction without absorption can be achieved.

  12. Phase-dependent high refractive index without absorption in a four-level inverted-Y atomic system

    SciTech Connect

    Zhi-Qiang Zeng; Fu-Ti Liu; Yu-Ping Wang; Zeng-Hui Gao

    2015-01-31

    We consider a closed four-level inverted-Y system in the presence and the absence of a microwave field. It is found that due to the quantum coherence between the two lower levels, either induced by the spontaneous decay or by the microwave field, the refraction – absorption properties of the system can be modulated by controlling the relative phase of the applied fields in both driven ways. In particular, by properly setting the values of the relative phase, the desirable high index of refraction without absorption can be achieved. (nonlinear optical phenomena)

  13. Multi level programming Paradigm for Extreme Computing

    NASA Astrophysics Data System (ADS)

    Petiton, S.; Sato, M.; Emad, N.; Calvin, C.; Tsuji, M.; Dandouna, M.

    2014-06-01

    Abstract: In order to propose a framework and programming paradigms for post-petascale computing, on the road to exascale computing and beyond, we introduced new languages, associated with a hierarchical multi-level programming paradigm, allowing scientific end-users and developers to program highly hierarchical architectures designed for extreme computing. In this paper, we explain the interest of such hierarchical multi-level programming paradigm for extreme computing and its well adaptation to several large computational science applications, such as for linear algebra solvers used for reactor core physic. We describe the YML language and framework allowing describing graphs of parallel components, which may be developed using PGAS-like language such as XMP, scheduled and computed on supercomputers. Then, we propose experimentations on supercomputers (such as the "K" and "Hooper" ones) of the hybrid method MERAM (Multiple Explicitly Restarted Arnoldi Method) as a case study for iterative methods manipulating sparse matrices, and the block Gauss-Jordan method as a case study for direct method manipulating dense matrices. We conclude proposing evolutions for this programming paradigm.

  14. Electronic multi-purpose material level sensor

    DOEpatents

    McEwan, T.E.

    1997-03-11

    The present electronic multi-purpose material level sensor is based on time domain reflectometry (TDR) of very short electrical pulses. Pulses are propagated along a transmission line that is partially immersed in a liquid, powder, or other substance such as grain in a silo. The time difference of the reflections at the start of the transmission line and the air/liquid interface are used to determine levels to better than 0.01 inch. The sensor is essentially independent of circuit element and temperature variations, and can be mass produced at an extremely low price. The transmission line may be a Goubau line, microstrip, coaxial cable, twin lead, CPS or CPW, and may typically be a strip placed along the inside wall of a tank. The reflected pulses also contain information about strata within the liquid such as sludge-build-up at the bottom of an oil tank. 9 figs.

  15. Electronic multi-purpose material level sensor

    DOEpatents

    McEwan, Thomas E.

    1997-01-01

    The present electronic multi-purpose material level sensor is based on time domain reflectometry (TDR) of very short electrical pulses. Pulses are propagated along a transmission line that is partially immersed in a liquid, powder, or other substance such as grain in a silo. The time difference of the reflections at the start of the transmission line and the air/liquid interface are used to determine levels to better than 0.01 inch. The sensor is essentially independent of circuit element and temperature variations, and can be mass produced at an extremely low price. The transmission line may be a Goubau line, microstrip, coaxial cable, twin lead, CPS or CPW, and may typically be a strip placed along the inside wall of a tank. The reflected pulses also contain information about strata within the liquid such as sludge-build-up at the bottom of an oil tank.

  16. Probabilistic Multi-Scale, Multi-Level, Multi-Disciplinary Analysis and Optimization of Engine Structures

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.; Abumeri, Galib H.

    2000-01-01

    Aircraft engines are assemblies of dynamically interacting components. Engine updates to keep present aircraft flying safely and engines for new aircraft are progressively required to operate in more demanding technological and environmental requirements. Designs to effectively meet those requirements are necessarily collections of multi-scale, multi-level, multi-disciplinary analysis and optimization methods and probabilistic methods are necessary to quantify respective uncertainties. These types of methods are the only ones that can formally evaluate advanced composite designs which satisfy those progressively demanding requirements while assuring minimum cost, maximum reliability and maximum durability. Recent research activities at NASA Glenn Research Center have focused on developing multi-scale, multi-level, multidisciplinary analysis and optimization methods. Multi-scale refers to formal methods which describe complex material behavior metal or composite; multi-level refers to integration of participating disciplines to describe a structural response at the scale of interest; multidisciplinary refers to open-ended for various existing and yet to be developed discipline constructs required to formally predict/describe a structural response in engine operating environments. For example, these include but are not limited to: multi-factor models for material behavior, multi-scale composite mechanics, general purpose structural analysis, progressive structural fracture for evaluating durability and integrity, noise and acoustic fatigue, emission requirements, hot fluid mechanics, heat-transfer and probabilistic simulations. Many of these, as well as others, are encompassed in an integrated computer code identified as Engine Structures Technology Benefits Estimator (EST/BEST) or Multi-faceted/Engine Structures Optimization (MP/ESTOP). The discipline modules integrated in MP/ESTOP include: engine cycle (thermodynamics), engine weights, internal fluid mechanics, cost, mission and coupled structural/thermal, various composite property simulators and probabilistic methods to evaluate uncertainty effects (scatter ranges) in all the design parameters. The objective of the proposed paper is to briefly describe a multi-faceted design analysis and optimization capability for coupled multi-discipline engine structures optimization. Results are presented for engine and aircraft type metrics to illustrate the versatility of that capability. Results are also presented for reliability, noise and fatigue to illustrate its inclusiveness. For example, replacing metal rotors with composites reduces the engine weight by 20 percent, 15 percent noise reduction, and an order of magnitude improvement in reliability. Composite designs exist to increase fatigue life by at least two orders of magnitude compared to state-of-the-art metals.

  17. An advanced static var compensator based on a three level IGBT inverter modelling analysis and active power filtering

    NASA Astrophysics Data System (ADS)

    Draou, Azeddine

    2012-12-01

    This paper presents the dynamic performance analysis of an Advanced Static Var Compensator (ASVC) using three-level neutral point-clamped voltage source inverter. The paper presents the principles of operating and the method of reference currents generation. The dynamic behaviour of the system is further analysed using Matlab/Simulink with SimPower Systems toolbox through a set of simulation tests. The results obtained have been applied to an active power filter which might lead to the design of a robust controller for current harmonics and reactive power applications

  18. Fuzzy Control of the Permanent Magnet Synchronous Machine Singularly Perturbed Fed By a Three Level Inverter

    NASA Astrophysics Data System (ADS)

    Massoum, Ahmed; Meroufel, Abdelkader; Wira, Patrice; Fellah, Mohammed Karim

    2012-05-01

    In this paper, we present the control technique based on the singular perturbation technique controlled by a fuzzy regulator applied to the permanent magnet synchronous machine (PMSM). This technique applied to the PMSM conducts to a separation of the variables into disjoined subset or two separated models: one having a slow dynamics, and the other a fast dynamics. To ensure certain robustness to the decoupled control system based on these techniques, the control speed and the Id current is carried out by fuzzy regulators. A qualitative analysis of the principal variables evolution describing the behavior of the global system (PMSM-Inverter with MLI-Control) and its robustness is developed by several tests of digital simulation in last stage.

  19. Milliwatt dc/dc Inverter

    NASA Technical Reports Server (NTRS)

    Mclyman, C. W.

    1983-01-01

    Compact dc/dc inverter uses single integrated-circuit package containing six inverter gates that generate and amplify 100-kHz square-wave switching signal. Square-wave switching inverts 10-volt local power to isolated voltage at another desired level. Relatively high operating frequency reduces size of filter capacitors required, resulting in small package unit.

  20. Inverting the Linear Algebra Classroom

    ERIC Educational Resources Information Center

    Talbert, Robert

    2014-01-01

    The inverted classroom is a course design model in which students' initial contact with new information takes place outside of class meetings, and students spend class time on high-level sense-making activities. The inverted classroom model is so called because it inverts or "flips" the usual classroom design where typically class

  1. Inverting the Linear Algebra Classroom

    ERIC Educational Resources Information Center

    Talbert, Robert

    2014-01-01

    The inverted classroom is a course design model in which students' initial contact with new information takes place outside of class meetings, and students spend class time on high-level sense-making activities. The inverted classroom model is so called because it inverts or "flips" the usual classroom design where typically class…

  2. Multi-level regulation and metabolic scaling.

    PubMed

    Suarez, Raul K; Darveau, Charles A

    2005-05-01

    Metabolic control analysis has revealed that flux through pathways is the consequence of system properties, i.e. shared control by multiple steps, as well as the kinetic effects of various pathways and processes over each other. This implies that the allometric scaling of flux rates must be understood in terms of properties that pertain to the regulation of flux rates. In contrast, proponents of models considering the scaling of branching or fractal-like systems suggest that supply rates determine metabolic rates. Therefore, the allometric scaling of supply alone provides a sufficient explanation for the allometric scaling of metabolism. Examination of empirical data from the literature of comparative physiology reveals that basal metabolic rates (BMR) are driven by rates of energy expenditure within internal organs and that the allometric scaling of BMR can be understood in terms of the scaling of the masses and metabolic rates of internal organs. Organ metabolic rates represent the sum of tissue metabolic rates while, within tissues, cellular metabolic rates are the outcome of shared regulation by multiple processes. Maximal metabolic rates (MMR, measured as maximum rates of O2 consumption, VO2max) during exercise also scale allometrically, are also subject to control by multiple processes, but are due mainly to O2 consumption by locomotory muscles. Thus, analyses of the scaling of MMR must consider the scaling of both muscle mass and muscle energy expenditure. Consistent with the principle of symmorphosis, allometry in capacities for supply (the outcome of physical design constraints) is observed to be roughly matched by allometry in capacities for demand (i.e. for energy expenditure). However, physiological rates most often fall far below maximum capacities and are subject to multi-step regulation. Thus, mechanistic explanations for the scaling of BMR and MMR must consider the manner in which capacities are matched and how rates are regulated at multiple levels of biological organization. PMID:15855394

  3. Evidencing Learning Outcomes: A Multi-Level, Multi-Dimensional Course Alignment Model

    ERIC Educational Resources Information Center

    Sridharan, Bhavani; Leitch, Shona; Watty, Kim

    2015-01-01

    This conceptual framework proposes a multi-level, multi-dimensional course alignment model to implement a contextualised constructive alignment of rubric design that authentically evidences and assesses learning outcomes. By embedding quality control mechanisms at each level for each dimension, this model facilitates the development of an aligned

  4. Evidencing Learning Outcomes: A Multi-Level, Multi-Dimensional Course Alignment Model

    ERIC Educational Resources Information Center

    Sridharan, Bhavani; Leitch, Shona; Watty, Kim

    2015-01-01

    This conceptual framework proposes a multi-level, multi-dimensional course alignment model to implement a contextualised constructive alignment of rubric design that authentically evidences and assesses learning outcomes. By embedding quality control mechanisms at each level for each dimension, this model facilitates the development of an aligned…

  5. A low-power inverter-based CMOS level-crossing analog-to-digital converter for low-frequency biosignal sensing

    NASA Astrophysics Data System (ADS)

    Tanaka, Suiki; Niitsu, Kiichi; Nakazato, Kazuo

    2016-03-01

    Low-power analog-to-digital conversion is a key technique for power-limited biomedical applications such as power-limited continuous glucose monitoring. However, a conventional uniform-sampling analog-to-digital converter (ADC) is not suitable for nonuniform biosignals. A level-crossing ADC (LC-ADC) is a promising candidate for low-power biosignal processing because of its event-driven properties. The LC-ADC acquires data by level-crossing sampling. When an input signal crosses the threshold level, the LC-ADC samples the signal. The conventional LC-ADC employs a power-hungry comparator. In this paper, we present a low-power inverter-based LC-ADC. By adjusting the threshold level of the inverter, it can be used as a threshold-fixed window comparator. By using the inverter as an alternative to a comparator, power consumption can be markedly reduced. As a result, the total power consumption is successfully reduced by 90% of that of previous LC-ADC. The inverter-based LC-ADC was found to be very suitable for use in power-limited biomedical devices.

  6. Inverted Perceptual Judgment of Nociceptive Stimuli at Threshold Level following Inconsistent Cues

    PubMed Central

    Walter, Carmen; Dimova, Violeta; Bu, Julia; Parnham, Michael J.; Oertel, Bruno G.; Ltsch, Jrn

    2015-01-01

    Objective The perception of pain is susceptible to modulation by psychological and contextual factors. It has been shown that subjects judge noxious stimuli as more painful in a respective suggestive context, which disappears when the modifying context is resolved. However, a context in which subjects judge the painfulness of a nociceptive stimulus in exactly the opposite direction to that of the cues has never been shown so far. Methods Nociceptive stimuli (300 ms intranasal gaseous CO2) at the individual pain threshold level were applied after a visual cue announcing the stimulus as either no pain, merely a stimulus, or pain. Among the stimuli at threshold level, other CO2 stimuli that were clearly below or above pain threshold were randomly interspersed. These were announced beforehand in 12 subjects randomly with correct or incorrect cues, i.e., clearly painful or clearly non-painful stimuli were announced equally often as not painful or painful. By contrast, in a subsequent group of another 12 subjects, the stimuli were always announced correctly with respect to the evoked pain. Results The random and often incorrect announcement of stimuli clearly below or above pain threshold caused the subjects to rate the stimuli at pain-threshold level in the opposite direction of the cue, i.e., when the stimuli were announced as pain significantly more often than as non-painful and vice versa (p < 10-4). By contrast, in the absence of incongruence between announcement and perception of the far-from-threshold stimuli, stimuli at pain threshold were rated in the cued direction. Conclusions The present study revealed the induction of associations incongruent with a given message in the perception of pain. We created a context of unreliable cues whereby subjects perceived the stimulus opposite to that suggested by a prior cue, i.e., potentially nociceptive stimuli at pain threshold level that were announced as painful were judged as non-painful and vice versa. These findings are consistent with reported data on the effects of distrust on non-painful cognitive responses. PMID:26147732

  7. Multilevel DC link inverter

    DOEpatents

    Su, Gui-Jia

    2003-06-10

    A multilevel DC link inverter and method for improving torque response and current regulation in permanent magnet motors and switched reluctance motors having a low inductance includes a plurality of voltage controlled cells connected in series for applying a resulting dc voltage comprised of one or more incremental dc voltages. The cells are provided with switches for increasing the resulting applied dc voltage as speed and back EMF increase, while limiting the voltage that is applied to the commutation switches to perform PWM or dc voltage stepping functions, so as to limit current ripple in the stator windings below an acceptable level, typically 5%. Several embodiments are disclosed including inverters using IGBT's, inverters using thyristors. All of the inverters are operable in both motoring and regenerating modes.

  8. Multi-Level Sequential Pattern Mining Based on Prime Encoding

    NASA Astrophysics Data System (ADS)

    Lianglei, Sun; Yun, Li; Jiang, Yin

    Encoding is not only to express the hierarchical relationship, but also to facilitate the identification of the relationship between different levels, which will directly affect the efficiency of the algorithm in the area of mining the multi-level sequential pattern. In this paper, we prove that one step of division operation can decide the parent-child relationship between different levels by using prime encoding and present PMSM algorithm and CROSS-PMSM algorithm which are based on prime encoding for mining multi-level sequential pattern and cross-level sequential pattern respectively. Experimental results show that the algorithm can effectively extract multi-level and cross-level sequential pattern from the sequence database.

  9. Squeezed light from conventionally pumped multi-level lasers

    NASA Technical Reports Server (NTRS)

    Ralph, T. C.; Savage, C. M.

    1992-01-01

    We have calculated the amplitude squeezing in the output of several conventionally pumped multi-level lasers. We present results which show that standard laser models can produce significantly squeezed outputs in certain parameter ranges.

  10. A method for predicting the noise levels of coannular jets with inverted velocity profiles

    NASA Technical Reports Server (NTRS)

    Russell, J. W.

    1979-01-01

    A coannular jet was equated with a single stream equivalent jet with the same mass flow, energy, and thrust. The acoustic characteristics of the coannular jet were then related to the acoustic characteristics of the single jet. Forward flight effects were included by incorporating a forward exponent, a Doppler amplification factor, and a Strouhal frequency shift. Model test data, including 48 static cases and 22 wind tunnel cases, were used to evaluate the prediction method. For the static cases and the low forward velocity wind tunnel cases, the spectral mean square pressure correlation coefficients were generally greater than 90 percent, and the spectral sound pressure level standard deviation were generally less than 3 decibels. The correlation coefficient and the standard deviation were not affected by changes in equivalent jet velocity. Limitations of the prediction method are also presented.

  11. Physiological levels of diacylglycerols in phospholipid membranes induce membrane fusion and stabilize inverted phases

    SciTech Connect

    Siegel, D.P.; Banschbach, J.; Alford, D.; Ellens, H.; Lis, L.J.; Quinn, P.J.; Yeagle, P.L.; Bentz, J. )

    1989-05-02

    In a previous paper, it was shown that liposome fusion rates are substantially enhanced under the same conditions which induce isotropic {sup 31}P NMR resonances in multilamellar dispersions of the same lipid. Both of these phenomena occur within the same temperature interval, {Delta}T{sub I}, below the L{sub {alpha}}/H{sub II} phase transition temperature, T{sub H}. T{sub H} and {Delta}T{sub I} can be extremely sensitive to the lipid composition. The present work shows that 2 mol % of diacylglycerols like those produced by the phosphatidylinositol cycle in vivo can lower T{sub H}, {Delta}T{sub I}, and the temperature for fast membrane fusion by 15-20{degree}C. N-Monomethylated dioleoylphosphatidylethanolamine is used as a model system. These results show that physiological levels of diacylglycerols can substantially increase the susceptibility of phospholipid membranes to fusion. This suggests that, in addition to their role in protein kinase C activation, diacylglycerols could play a more direct role in the fusion event during stimulus-exocytosis coupling in vivo.

  12. Compact plane illumination plugin device to enable light sheet fluorescence imaging of multi-cellular organisms on an inverted wide-field microscope.

    PubMed

    Guan, Zeyi; Lee, Juhyun; Jiang, Hao; Dong, Siyan; Jen, Nelson; Hsiai, Tzung; Ho, Chih-Ming; Fei, Peng

    2016-01-01

    We developed a compact plane illumination plugin (PIP) device which enabled plane illumination and light sheet fluorescence imaging on a conventional inverted microscope. The PIP device allowed the integration of microscope with tunable laser sheet profile, fast image acquisition, and 3-D scanning. The device is both compact, measuring approximately 15 by 5 by 5 cm, and cost-effective, since we employed consumer electronics and an inexpensive device molding method. We demonstrated that PIP provided significant contrast and resolution enhancement to conventional microscopy through imaging different multi-cellular fluorescent structures, including 3-D branched cells in vitro and live zebrafish embryos. Imaging with the integration of PIP greatly reduced out-of-focus contamination and generated sharper contrast in acquired 2-D plane images when compared with the stand-alone inverted microscope. As a result, the dynamic fluid domain of the beating zebrafish heart was clearly segmented and the functional monitoring of the heart was achieved. Furthermore, the enhanced axial resolution established by thin plane illumination of PIP enabled the 3-D reconstruction of the branched cellular structures, which leads to the improvement on the functionality of the wide field microscopy. PMID:26819828

  13. Compact plane illumination plugin device to enable light sheet fluorescence imaging of multi-cellular organisms on an inverted wide-field microscope

    PubMed Central

    Guan, Zeyi; Lee, Juhyun; Jiang, Hao; Dong, Siyan; Jen, Nelson; Hsiai, Tzung; Ho, Chih-Ming; Fei, Peng

    2015-01-01

    We developed a compact plane illumination plugin (PIP) device which enabled plane illumination and light sheet fluorescence imaging on a conventional inverted microscope. The PIP device allowed the integration of microscope with tunable laser sheet profile, fast image acquisition, and 3-D scanning. The device is both compact, measuring approximately 15 by 5 by 5 cm, and cost-effective, since we employed consumer electronics and an inexpensive device molding method. We demonstrated that PIP provided significant contrast and resolution enhancement to conventional microscopy through imaging different multi-cellular fluorescent structures, including 3-D branched cells in vitro and live zebrafish embryos. Imaging with the integration of PIP greatly reduced out-of-focus contamination and generated sharper contrast in acquired 2-D plane images when compared with the stand-alone inverted microscope. As a result, the dynamic fluid domain of the beating zebrafish heart was clearly segmented and the functional monitoring of the heart was achieved. Furthermore, the enhanced axial resolution established by thin plane illumination of PIP enabled the 3-D reconstruction of the branched cellular structures, which leads to the improvement on the functionality of the wide field microscopy. PMID:26819828

  14. Hierarchical Classification by Multi-Level Reciprocity

    ERIC Educational Resources Information Center

    McQuitty, Louis L.

    1970-01-01

    A method is developed and illustrated which relaxes the principle of reciprocity in relation to characteristics of data and classifies in terms of successive levels of reciprocity, using two versions: (a) successive linkages, and (b) core assignments. (Author/RF)

  15. Inverted Channel

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This Mars Global Surveyor (MGS) Orbiter Camera (MOC) image shows an inverted channel running down, through a valley in the Memnonia Sulci region of Mars. The original channel is gone, as are the rocks through which it cut. The channel floor and/or the material that filled the channel was more resistant to erosion, and thus left standing high as a ridge. Inverted channels and valleys are common on Mars. Many old valley networks have been filled, buried, and in some cases, exhumed and inverted, all across the planet.

    Location near: 11.4oS, 174.4oW Image width: 3.0 km (1.9 mi) Illumination from: upper left Season: Southern Winter

  16. Inverted Channels

    NASA Technical Reports Server (NTRS)

    2005-01-01

    18 September 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the inverted remains of several channels in a fan-like complex in the Aeolis region of Mars. The inverted channels are the flat-topped ridges that trend from lower right toward upper left (southeast to northwest). Other ridges, trending from lower left toward upper right (southwest to northeast) are yardangs, the products of wind erosion. The channels were inverted by erosion, as well -- the tops of these ridges were once the floor of the channels (or the tops of materials that filled the channels).

    Location near: 5.1oS, 205.0oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Southern Spring

  17. Multi-Level Captioning: Alternatives that Match the Viewers' Abilities.

    ERIC Educational Resources Information Center

    Montandon, Betsy

    1982-01-01

    The Multi-Level Linguistic Captioning Project at public television station WGBH in Boston developed a method of captioning that controls vocabulary and idiomatic expressions, syntax, and inference at each of three captioning levels (simplest language, greater sophistication, and most difficult). Examples are provided along with background

  18. Multi-stage decoding for multi-level block modulation codes

    NASA Technical Reports Server (NTRS)

    Lin, Shu

    1991-01-01

    In this paper, we investigate various types of multi-stage decoding for multi-level block modulation codes, in which the decoding of a component code at each stage can be either soft-decision or hard-decision, maximum likelihood or bounded-distance. Error performance of codes is analyzed for a memoryless additive channel based on various types of multi-stage decoding, and upper bounds on the probability of an incorrect decoding are derived. Based on our study and computation results, we find that, if component codes of a multi-level modulation code and types of decoding at various stages are chosen properly, high spectral efficiency and large coding gain can be achieved with reduced decoding complexity. In particular, we find that the difference in performance between the suboptimum multi-stage soft-decision maximum likelihood decoding of a modulation code and the single-stage optimum decoding of the overall code is very small: only a fraction of dB loss in SNR at the probability of an incorrect decoding for a block of 10(exp -6). Multi-stage decoding of multi-level modulation codes really offers a way to achieve the best of three worlds, bandwidth efficiency, coding gain, and decoding complexity.

  19. Multi-level Hierarchical Poly Tree computer architectures

    NASA Technical Reports Server (NTRS)

    Padovan, Joe; Gute, Doug

    1990-01-01

    Based on the concept of hierarchical substructuring, this paper develops an optimal multi-level Hierarchical Poly Tree (HPT) parallel computer architecture scheme which is applicable to the solution of finite element and difference simulations. Emphasis is given to minimizing computational effort, in-core/out-of-core memory requirements, and the data transfer between processors. In addition, a simplified communications network that reduces the number of I/O channels between processors is presented. HPT configurations that yield optimal superlinearities are also demonstrated. Moreover, to generalize the scope of applicability, special attention is given to developing: (1) multi-level reduction trees which provide an orderly/optimal procedure by which model densification/simplification can be achieved, as well as (2) methodologies enabling processor grading that yields architectures with varying types of multi-level granularity.

  20. Simplified High-Power Inverter

    NASA Technical Reports Server (NTRS)

    Edwards, D. B.; Rippel, W. E.

    1984-01-01

    Solid-state inverter simplified by use of single gate-turnoff device (GTO) to commutate multiple silicon controlled rectifiers (SCR's). By eliminating conventional commutation circuitry, GTO reduces cost, size and weight. GTO commutation applicable to inverters of greater than 1-kilowatt capacity. Applications include emergency power, load leveling, drives for traction and stationary polyphase motors, and photovoltaic-power conditioning.

  1. Inverted Channels

    NASA Technical Reports Server (NTRS)

    2005-01-01

    10 June 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a complex of overlapping, inverted channels in a fan exposed by erosion, then mantled by dust, in the Aeolis region of Mars. Aeolis exhibits an abundance of inverted channels and fan-shaped forms, largely created by a liquid such as water, and then preserved in layered, sedimentary rock that has been subsequently eroded by wind.

    Location near: 4.6oS, 205.3oW Image width: 3 km (1.9 mi Illumination from: upper left Season: Southern Spring

  2. Inverted Channels

    NASA Technical Reports Server (NTRS)

    2005-01-01

    15 May 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the inverted traces of old channels in a complex, wind-eroded fan located in the Aeolis region of Mars.

    Location near: 6.3oS, 208.9oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Winter

  3. A Study On Direct Selling Through Multi Level Marketing

    NASA Astrophysics Data System (ADS)

    Merlin, F. Mary

    2012-09-01

    Direct selling is a multi-level marketing in which the sales force is compensated not only for the sales they make but also for the sales done through their recruit. This recruited sales force is referred to as the participants who can provide multiple levels of compensation.A person's job would be to recruit others to sell their product, and in return, receive a percentage of their sales. The next person's job then is to recruit people even more so below them, and receive a percentage of their sales. Other terms for Multi-level marketing include network marketing and referral marketing. Commonly, the salespeople are expected to sell products directly to consumers by means of relationship through referrals marketing. Some people use direct selling as a synonym for MLM, although MLM is only one type of direct selling

  4. Device-Level Models Using Multi-Valley Effective Mass

    NASA Astrophysics Data System (ADS)

    Baczewski, Andrew D.; Frees, Adam; Gamble, John King; Gao, Xujiao; Jacobson, N. Tobias; Mitchell, John A.; Montaño, Inès; Muller, Richard P.; Nielsen, Erik

    2015-03-01

    Continued progress in quantum electronics depends critically on the availability of robust device-level modeling tools that capture a wide range of physics and effective mass theory (EMT) is one means of building such models. Recent developments in multi-valley EMT show quantitative agreement with more detailed atomistic tight-binding calculations of phosphorus donors in silicon (Gamble, et. al., arXiv:1408.3159). Leveraging existing PDE solvers, we are developing a framework in which this multi-valley EMT is coupled to an integrated device-level description of several experimentally active qubit technologies. Device-level simulations of quantum operations will be discussed, as well as the extraction of process matrices at this level of theory. The authors gratefully acknowledge support from the Sandia National Laboratories Truman Fellowship Program, which is funded by the Laboratory Directed Research and Development (LDRD) Program. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Security Administration under contract DE-AC04-94AL85000.

  5. Overload protection system for power inverter

    NASA Technical Reports Server (NTRS)

    Nagano, S. (inventor)

    1977-01-01

    An overload protection system for a power inverter utilized a first circuit for monitoring current to the load from the power inverter to detect an overload and a control circuit to shut off the power inverter, when an overload condition was detected. At the same time, a monitoring current inverter was turned on to deliver current to the load at a very low power level. A second circuit monitored current to the load, from the monitoring current inverter, to hold the power inverter off through the control circuit, until the overload condition was cleared so that the control circuit may be deactivated in order for the power inverter to be restored after the monitoring current inverter is turned off completely.

  6. Multi-stage decoding for multi-level block modulation codes

    NASA Technical Reports Server (NTRS)

    Lin, Shu; Kasami, Tadao

    1991-01-01

    Various types of multistage decoding for multilevel block modulation codes, in which the decoding of a component code at each stage can be either soft decision or hard decision, maximum likelihood or bounded distance are discussed. Error performance for codes is analyzed for a memoryless additive channel based on various types of multi-stage decoding, and upper bounds on the probability of an incorrect decoding are derived. It was found that, if component codes of a multi-level modulation code and types of decoding at various stages are chosen properly, high spectral efficiency and large coding gain can be achieved with reduced decoding complexity. It was found that the difference in performance between the suboptimum multi-stage soft decision maximum likelihood decoding of a modulation code and the single stage optimum decoding of the overall code is very small, only a fraction of dB loss in SNR at the probability of an incorrect decoding for a block of 10(exp -6). Multi-stage decoding of multi-level modulation codes really offers a way to achieve the best of three worlds, bandwidth efficiency, coding gain, and decoding complexity.

  7. Multi-level Hybrid Cache: Impact and Feasibility

    SciTech Connect

    Zhang, Zhe; Kim, Youngjae; Ma, Xiaosong; Shipman, Galen M; Zhou, Yuanyuan

    2012-02-01

    Storage class memories, including flash, has been attracting much attention as promising candidates fitting into in today's enterprise storage systems. In particular, since the cost and performance characteristics of flash are in-between those of DRAM and hard disks, it has been considered by many studies as an secondary caching layer underneath main memory cache. However, there has been a lack of studies of correlation and interdependency between DRAM and flash caching. This paper views this problem as a special form of multi-level caching, and tries to understand the benefits of this multi-level hybrid cache hierarchy. We reveal that significant costs could be saved by using Flash to reduce the size of DRAM cache, while maintaing the same performance. We also discuss design challenges of using flash in the caching hierarchy and present potential solutions.

  8. Fundamental-Frequency-Modulated Six-Level Diode-Clamped Multilevel Inverter for Three-Phase Stand-Alone Photovoltaic System

    SciTech Connect

    Ozdemir, Engin; Ozdemir, Sule; Tolbert, Leon M

    2009-01-01

    This paper presents a fundamental-frequency-modulated diode-clamped multilevel inverter (DCMLI) scheme for a three-phase stand-alone photovoltaic (PV) system. The system consists of five series-connected PV modules, a six-level DCMLI generating fundamental-modulation staircase three-phase output voltages, and a three-phase induction motor as the load. In order to validate the proposed concept, simulation studies and experimental measurements using a small-scale laboratory prototype are also presented. The results show the feasibility of the fundamental frequency switching application in three-phase stand-alone PV power systems.

  9. A multi-level method for sparse linear systems

    SciTech Connect

    Shapira, Y.

    1997-09-01

    A multi-level method for the solution of sparse linear systems is introduced. The definition of the method is based on data from the coefficient matrix alone. An upper bound for the condition number is available for certain symmetric positive definite (SPD) problems. Numerical experiments confirm the analysis and illustrate the efficiency of the method for diffusion problems with discontinuous coefficients with discontinuities which are not aligned with the coarse meshes.

  10. On decoding of multi-level MPSK modulation codes

    NASA Technical Reports Server (NTRS)

    Lin, Shu; Gupta, Alok Kumar

    1990-01-01

    The decoding problem of multi-level block modulation codes is investigated. The hardware design of soft-decision Viterbi decoder for some short length 8-PSK block modulation codes is presented. An effective way to reduce the hardware complexity of the decoder by reducing the branch metric and path metric, using a non-uniform floating-point to integer mapping scheme, is proposed and discussed. The simulation results of the design are presented. The multi-stage decoding (MSD) of multi-level modulation codes is also investigated. The cases of soft-decision and hard-decision MSD are considered and their performance are evaluated for several codes of different lengths and different minimum squared Euclidean distances. It is shown that the soft-decision MSD reduces the decoding complexity drastically and it is suboptimum. The hard-decision MSD further simplifies the decoding while still maintaining a reasonable coding gain over the uncoded system, if the component codes are chosen properly. Finally, some basic 3-level 8-PSK modulation codes using BCH codes as component codes are constructed and their coding gains are found for hard decision multistage decoding.

  11. Complex Multi-modal Multi-level Influence Networks - Affordable Housing Case Study -

    NASA Astrophysics Data System (ADS)

    Beautement, Patrick; Brnner, Christine

    Most influence networks are depicted as nodes and links operating in the manner of a feed-forward neural network where both nodes and links appear to be homogenous in their nature. Experience has shown that not only do these networks fail to deal adequately with reality, but also that practitioners struggle to understand why. This paper addresses this challenge by examining the rich, multi-level and multi-modal nature of influence networks and proposes an approach drawing inspiration from complexity science - leading to multi-perspective techniques which enable influence networks to be used to more effectively to capture, visualise and understand complex situations, so providing insights to support effective decision-making. The paper gives evidence (from a case study looking at the provision of affordable housing in the UK) which illustrates how the techniques have been employed and what benefits accrued.

  12. Power inverters

    DOEpatents

    Miller, David H. (Redondo Beach, CA); Korich, Mark D. (Chino Hills, CA); Smith, Gregory S. (Woodland Hills, CA)

    2011-11-15

    Power inverters include a frame and a power module. The frame has a sidewall including an opening and defining a fluid passageway. The power module is coupled to the frame over the opening and includes a substrate, die, and an encasement. The substrate includes a first side, a second side, a center, an outer periphery, and an outer edge, and the first side of the substrate comprises a first outer layer including a metal material. The die are positioned in the substrate center and are coupled to the substrate first side. The encasement is molded over the outer periphery on the substrate first side, the substrate second side, and the substrate outer edge and around the die. The encasement, coupled to the substrate, forms a seal with the metal material. The second side of the substrate is positioned to directly contact a fluid flowing through the fluid passageway.

  13. Inverted Valley

    NASA Technical Reports Server (NTRS)

    2005-01-01

    10 September 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an inverted valley in eastern Arabia Terra. The relatively flat-topped ridge that runs down much of the length of this picture was once the floor, or a material covering the floor, of an ancient martian valley. The floor material was harder and more resistant to erosion than the rocks into which the valley had been cut. Thus, erosion removed the rocks that were cut by the valley, and then removed additional rocks that were lower than the valley floor, leaving what was once a valley as a high-standing ridge.

    Location near: 11.4oN, 312.9oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Autumn

  14. Stream, Inverted

    NASA Technical Reports Server (NTRS)

    2006-01-01

    27 July 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the inverted, eroded remains of a channel -- now standing as a complex ridge that runs across the middle of this scene -- in dust-mantled terrain west of Sinus Meridiani, Mars. The original channel might have been carved by running water, but too little detail remains today to provide any certainty as to whether water was the culprit.

    Location near: 5.6oN, 7.6oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Northern Spring

  15. Inverted Valley

    NASA Technical Reports Server (NTRS)

    2005-01-01

    15 December 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a somewhat sinuous, nearly flat-topped ridge, located in eastern Arabia Terra. The ridgetop was once the floor of a valley, perhaps carved by running water. The valley floor, or material that covered the floor, was more resistant to erosion than the surrounding rock into which the valley was cut. Thus, over time, the valley disappeared and its floor was left standing high as a ridge. Inverted valleys are common on Mars; they also occur on Earth.

    Location near: 10.8oN, 313.2oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Winter

  16. Large swings in the forward-backward super-radiant emission direction from a nearly inverted ensemble of a three-level cascade system

    NASA Astrophysics Data System (ADS)

    Manassah, Jamal T.

    2016-02-01

    I show unambiguously that, in a slab geometry, the direction of emission of the super-radiant pulse from the lower two levels' transition in an ensemble of a three-level cascade homogeneously broadened atomic system, which was initially prepared in a nearly fully inverted coherent state, exhibits high sensitivity to the value of the initial atomic population for the case that the slab thickness is equal to n λ0/2 (n is an integer and λ0 is the wavelength of the atomic transition). Specifically, I compute, in this regime, the swings in the ratio of the forward over backward fluxes for both transitions as a function of the initial population of the highest energy level.

  17. On codes with multi-level error-correction capabilities

    NASA Technical Reports Server (NTRS)

    Lin, Shu

    1987-01-01

    In conventional coding for error control, all the information symbols of a message are regarded equally significant, and hence codes are devised to provide equal protection for each information symbol against channel errors. However, in some occasions, some information symbols in a message are more significant than the other symbols. As a result, it is desired to devise codes with multilevel error-correcting capabilities. Another situation where codes with multi-level error-correcting capabilities are desired is in broadcast communication systems. An m-user broadcast channel has one input and m outputs. The single input and each output form a component channel. The component channels may have different noise levels, and hence the messages transmitted over the component channels require different levels of protection against errors. Block codes with multi-level error-correcting capabilities are also known as unequal error protection (UEP) codes. Structural properties of these codes are derived. Based on these structural properties, two classes of UEP codes are constructed.

  18. Constrained Multi-Level Algorithm for Trajectory Optimization

    NASA Astrophysics Data System (ADS)

    Adimurthy, V.; Tandon, S. R.; Jessy, Antony; Kumar, C. Ravi

    The emphasis on low cost access to space inspired many recent developments in the methodology of trajectory optimization. Ref.1 uses a spectral patching method for optimization, where global orthogonal polynomials are used to describe the dynamical constraints. A two-tier approach of optimization is used in Ref.2 for a missile mid-course trajectory optimization. A hybrid analytical/numerical approach is described in Ref.3, where an initial analytical vacuum solution is taken and gradually atmospheric effects are introduced. Ref.4 emphasizes the fact that the nonlinear constraints which occur in the initial and middle portions of the trajectory behave very nonlinearly with respect the variables making the optimization very difficult to solve in the direct and indirect shooting methods. The problem is further made complex when different phases of the trajectory have different objectives of optimization and also have different path constraints. Such problems can be effectively addressed by multi-level optimization. In the multi-level methods reported so far, optimization is first done in identified sub-level problems, where some coordination variables are kept fixed for global iteration. After all the sub optimizations are completed, higher-level optimization iteration with all the coordination and main variables is done. This is followed by further sub system optimizations with new coordination variables. This process is continued until convergence. In this paper we use a multi-level constrained optimization algorithm which avoids the repeated local sub system optimizations and which also removes the problem of non-linear sensitivity inherent in the single step approaches. Fall-zone constraints, structural load constraints and thermal constraints are considered. In this algorithm, there is only a single multi-level sequence of state and multiplier updates in a framework of an augmented Lagrangian. Han Tapia multiplier updates are used in view of their special role in diagonalised methods, being the only single update with quadratic convergence. For a single level, the diagonalised multiplier method (DMM) is described in Ref.5. The main advantage of the two-level analogue of the DMM approach is that it avoids the inner loop optimizations required in the other methods. The scheme also introduces a gradient change measure to reduce the computational time needed to calculate the gradients. It is demonstrated that the new multi-level scheme leads to a robust procedure to handle the sensitivity of the constraints, and the multiple objectives of different trajectory phases. Ref. 1. Fahroo, F and Ross, M., " A Spectral Patching Method for Direct Trajectory Optimization" The Journal of the Astronautical Sciences, Vol.48, 2000, pp.269-286 Ref. 2. Phililps, C.A. and Drake, J.C., "Trajectory Optimization for a Missile using a Multitier Approach" Journal of Spacecraft and Rockets, Vol.37, 2000, pp.663-669 Ref. 3. Gath, P.F., and Calise, A.J., " Optimization of Launch Vehicle Ascent Trajectories with Path Constraints and Coast Arcs", Journal of Guidance, Control, and Dynamics, Vol. 24, 2001, pp.296-304 Ref. 4. Betts, J.T., " Survey of Numerical Methods for Trajectory Optimization", Journal of Guidance, Control, and Dynamics, Vol.21, 1998, pp. 193-207 Ref. 5. Adimurthy, V., " Launch Vehicle Trajectory Optimization", Acta Astronautica, Vol.15, 1987, pp.845-850.

  19. Multi-level Full Virtualization of Power Management

    NASA Astrophysics Data System (ADS)

    Liu, Yongpeng; Chi, Wanqing; Liu, Yongyan

    Virtual machine technique is employed to improve system utilization and energy efficiency. However, isolation effect of virtualization imposes challenges to power management. A multi-level power behavior statistic framework is introduced to support power profiling of virtual device, virtual machine and host. Power management mechanisms are virtualized to map power management operations between virtual device and physical device. The power consumption of a virtual device is virtualized according to its performance share from the physical device. The experiments demonstrated that our power management virtualization solution has negligible decline of system performance.

  20. A multi-level multi-scale approach to study essential genes in Mycobacterium tuberculosis

    PubMed Central

    2013-01-01

    Background The set of indispensable genes that are required by an organism to grow and sustain life are termed as essential genes. There is a strong interest in identification of the set of essential genes, particularly in pathogens, not only for a better understanding of the pathogen biology, but also for identifying drug targets and the minimal gene set for the organism. Essentiality is inherently a systems property and requires consideration of the system as a whole for their identification. The available experimental approaches capture some aspects but each method comes with its own limitations. Moreover, they do not explain the basis for essentiality in most cases. A powerful prediction method to recognize this gene pool including rationalization of the known essential genes in a given organism would be very useful. Here we describe a multi-level multi-scale approach to identify the essential gene pool in a deadly pathogen, Mycobacterium tuberculosis. Results The multi-level workflow analyses the bacterial cell by studying (a) genome-wide gene expression profiles to identify the set of genes which show consistent and significant levels of expression in multiple samples of the same condition, (b) indispensability for growth by using gene expression integrated flux balance analysis of a genome-scale metabolic model, (c) importance for maintaining the integrity and flow in a protein-protein interaction network and (d) evolutionary conservation in a set of genomes of the same ecological niche. In the gene pool identified, the functional basis for essentiality has been addressed by studying residue level conservation and the sub-structure at the ligand binding pockets, from which essential amino acid residues in that pocket have also been identified. 283 genes were identified as essential genes with high-confidence. An agreement of about 73.5% is observed with that obtained from the experimental transposon mutagenesis technique. A large proportion of the identified genes belong to the class of intermediary metabolism and respiration. Conclusions The multi-scale, multi-level approach described can be generally applied to other pathogens as well. The essential gene pool identified form a basis for designing experiments to probe their finer functional roles and also serve as a ready shortlist for identifying drug targets. PMID:24308365

  1. The Importance of Proximal Fusion Level Selection for Outcomes of Multi-Level Lumbar Posterolateral Fusion

    PubMed Central

    Nam, Woo Dong

    2015-01-01

    Background There are few studies about risk factors for poor outcomes from multi-level lumbar posterolateral fusion limited to three or four level lumbar posterolateral fusions. The purpose of this study was to analyze the outcomes of multi-level lumbar posterolateral fusion and to search for possible risk factors for poor surgical outcomes. Methods We retrospectively analyzed 37 consecutive patients who underwent multi-level lumbar or lumbosacral posterolateral fusion with posterior instrumentation. The outcomes were deemed either 'good' or 'bad' based on clinical and radiological results. Many demographic and radiological factors were analyzed to examine potential risk factors for poor outcomes. Student t-test, Fisher exact test, and the chi-square test were used based on the nature of the variables. Multiple logistic regression analysis was used to exclude confounding factors. Results Twenty cases showed a good outcome (group A, 54.1%) and 17 cases showed a bad outcome (group B, 45.9%). The overall fusion rate was 70.3%. The revision procedures (group A: 1/20, 5.0%; group B: 4/17, 23.5%), proximal fusion to L2 (group A: 5/20, 25.0%; group B: 10/17, 58.8%), and severity of stenosis (group A: 12/19, 63.3%; group B: 3/11, 27.3%) were adopted as possible related factors to the outcome in univariate analysis. Multiple logistic regression analysis revealed that only the proximal fusion level (superior instrumented vertebra, SIV) was a significant risk factor. The cases in which SIV was L2 showed inferior outcomes than those in which SIV was L3. The odds ratio was 6.562 (95% confidence interval, 1.259 to 34.203). Conclusions The overall outcome of multi-level lumbar or lumbosacral posterolateral fusion was not as high as we had hoped it would be. Whether the SIV was L2 or L3 was the only significant risk factor identified for poor outcomes in multi-level lumbar or lumbosacral posterolateral fusion in the current study. Thus, the authors recommend that proximal fusion levels be carefully determined when multi-level lumbar fusions are considered. PMID:25729522

  2. Politics of innovation in multi-level water governance systems

    NASA Astrophysics Data System (ADS)

    Daniell, Katherine A.; Coombes, Peter J.; White, Ian

    2014-11-01

    Innovations are being proposed in many countries in order to support change towards more sustainable and water secure futures. However, the extent to which they can be implemented is subject to complex politics and powerful coalitions across multi-level governance systems and scales of interest. Exactly how innovation uptake can be best facilitated or blocked in these complex systems is thus a matter of important practical and research interest in water cycle management. From intervention research studies in Australia, China and Bulgaria, this paper seeks to describe and analyse the behind-the-scenes struggles and coalition-building that occurs between water utility providers, private companies, experts, communities and all levels of government in an effort to support or block specific innovations. The research findings suggest that in order to ensure successful passage of the proposed innovations, champions for it are required from at least two administrative levels, including one with innovation implementation capacity, as part of a larger supportive coalition. Higher governance levels can play an important enabling role in facilitating the passage of certain types of innovations that may be in competition with currently entrenched systems of water management. Due to a range of natural biases, experts on certain innovations and disciplines may form part of supporting or blocking coalitions but their evaluations of worth for water system sustainability and security are likely to be subject to competing claims based on different values and expertise, so may not necessarily be of use in resolving questions of "best courses of action". This remains a political values-based decision to be negotiated through the receiving multi-level water governance system.

  3. Multi-Level Bitmap Indexes for Flash Memory Storage

    SciTech Connect

    Wu, Kesheng; Madduri, Kamesh; Canon, Shane

    2010-07-23

    Due to their low access latency, high read speed, and power-efficient operation, flash memory storage devices are rapidly emerging as an attractive alternative to traditional magnetic storage devices. However, tests show that the most efficient indexing methods are not able to take advantage of the flash memory storage devices. In this paper, we present a set of multi-level bitmap indexes that can effectively take advantage of flash storage devices. These indexing methods use coarsely binned indexes to answer queries approximately, and then use finely binned indexes to refine the answers. Our new methods read significantly lower volumes of data at the expense of an increased disk access count, thus taking full advantage of the improved read speed and low access latency of flash devices. To demonstrate the advantage of these new indexes, we measure their performance on a number of storage systems using a standard data warehousing benchmark called the Set Query Benchmark. We observe that multi-level strategies on flash drives are up to 3 times faster than traditional indexing strategies on magnetic disk drives.

  4. Evolution of neuroarchitecture, multi-level analyses and calibrative reductionism

    PubMed Central

    Berntson, Gary G.; Norman, Greg J.; Hawkley, Louise C.; Cacioppo, John T.

    2012-01-01

    Evolution has sculpted the incredibly complex human nervous system, among the most complex functions of which extend beyond the individual to an intricate social structure. Although these functions are deterministic, those determinants are legion, heavily interacting and dependent on a specific evolutionary trajectory. That trajectory was directed by the adaptive significance of quasi-random genetic variations, but was also influenced by chance and caprice. With a different evolutionary pathway, the same neural elements could subserve functions distinctly different from what they do in extant human brains. Consequently, the properties of higher level neural networks cannot be derived readily from the properties of the lower level constituent elements, without studying these elements in the aggregate. Thus, a multi-level approach to integrative neuroscience may offer an optimal strategy. Moreover, the process of calibrative reductionism, by which concepts and understandings from one level of organization or analysis can mutually inform and calibrate those from other levels (both higher and lower), may represent a viable approach to the application of reductionism in science. This is especially relevant in social neuroscience, where the basic subject matter of interest is defined by interacting organisms across diverse environments. PMID:23386961

  5. Addressable multi-nozzle electrohydrodynamic jet printing with high consistency by multi-level voltage method

    NASA Astrophysics Data System (ADS)

    Pan, Yanqiao; Huang, YongAn; Guo, Lei; Ding, Yajiang; Yin, Zhouping

    2015-04-01

    It is critical and challenging to achieve the individual jetting ability and high consistency in multi-nozzle electrohydrodynamic jet printing (E-jet printing). We proposed multi-level voltage method (MVM) to implement the addressable E-jet printing using multiple parallel nozzles with high consistency. The fabricated multi-nozzle printhead for MVM consists of three parts: PMMA holder, stainless steel capillaries (27G, outer diameter 400 ?m) and FR-4 extractor layer. The key of MVM is to control the maximum meniscus electric field on each nozzle. The individual jetting control can be implemented when the rings under the jetting nozzles are 0 kV and the other rings are 0.5 kV. The onset electric field for each nozzle is 3.4 kV/mm by numerical simulation. Furthermore, a series of printing experiments are performed to show the advantage of MVM in printing consistency than the "one-voltage method" and "improved E-jet method", by combination with finite element analyses. The good dimension consistency (274?m, 276?m, 280?m) and position consistency of the droplet array on the hydrophobic Si substrate verified the enhancements. It shows that MVM is an effective technique to implement the addressable E-jet printing with multiple parallel nozzles in high consistency.

  6. 2.3-MW Medium-Voltage, Three-Level Wind Energy Inverter Applying a Unique Bus Structure and 4.5-kV Si/SiC Hybrid Isolated Power Modules: Preprint

    SciTech Connect

    Erdman, W.; Keller, J.; Grider, D.; VanBrunt, E.

    2014-11-01

    A high-efficiency, 2.3-MW, medium-voltage, three-level inverter utilizing 4.5-kV Si/SiC (silicon carbide) hybrid modules for wind energy applications is discussed. The inverter addresses recent trends in siting the inverter within the base of multimegawatt turbine towers. A simplified split, three-layer laminated bus structure that maintains low parasitic inductances is introduced along with a low-voltage, high-current test method for determining these inductances. Feed-thru bushings, edge fill methods, and other design features of the laminated bus structure provide voltage isolation that is consistent with the 10.4-kV module isolation levels. Inverter efficiency improvement is a result of the (essential) elimination of the reverse recovery charge present in 4.5-kV Si PIN diodes, which can produce a significant reduction in diode turn-off losses as well as insulated-gate bipolar transistor (IGBT) turn-on losses. The hybrid modules are supplied in industry-standard 140 mm x 130 mm and 190 mm x 130 mm packages to demonstrate direct module substitution into existing inverter designs. A focus on laminated bus/capacitor-bank/module subassembly level switching performance is presented.

  7. Multi-Level Analysis of Pulsed Detonation Engines

    NASA Technical Reports Server (NTRS)

    Ebrahimi, Houshang B.; Mohanraj, Rajendran; Merkle, Charles L.

    2001-01-01

    The present study explores some issues concerning the operational performance of pulsed detonation engines. Zero-, one- and two-dimensional, transient models are employed in a synergistic manner to elucidate the various characteristics that can be expected from each level of analysis. The zero-dimensional model provides rapid parametric trends that help to identify the global characteristics of pulsed detonation engines. The one-dimensional model adds key wave propagation issues that are omitted in the zero-dimensional model and helps to assess its limitations. Finally, the two-dimensional model allows estimates of the first-order multi-dimensional effects and provides an initial multi-dimensional end-correction for the one-dimensional model. The zero-dimensional results indicate that the pulsed detonation engine is competitive with a rocket engine when exhausting to vacuum conditions. At finite back pressures, the PDE out-performs the rocket if the combustion pressure rise from the detonation is added to the chamber pressure in the rocket. If the two peak pressures are the same, the rocket performance is higher. Two-dimensional corrections added to the one-dimensional model result in a modest improvement in predicted specific impulse over the constant pressure boundary condition.

  8. Multi-level particle packing model of ceramic agglomerates

    NASA Astrophysics Data System (ADS)

    Kim, Jong Cheol; Auh, Keun Ho; Martin, David M.

    2000-03-01

    Multi-level packing of spherical ceramic particles is simulated in three dimensions. The packing process is composed of two steps: particles are packed to make clusters and clusters are packed to make aggregates. Cluster rearrangement is simulated by randomly rolling each cluster over its neighbour's surface. The degree of cluster rearrangement during the cluster condensation process controls agglomerate compactness. This approach was possible using the simple assumption that clusters are spheres with radii equal to the mean interparticle distance in the clusters. The clusters which are rearranged have higher packing density than the clusters which are not rearranged. The effect of cluster rearrangement during condensation on the total compactness of agglomerates is found to be comparable to the effect of particle rearrangement during condensation.

  9. Development of the Multi-Level Seismic Receiver (MLSR)

    SciTech Connect

    Sleefe, G.E.; Engler, B.P.; Drozda, P.M.; Franco, R.J.; Morgan, J.

    1995-02-01

    The Advanced Geophysical Technology Department (6114) and the Telemetry Technology Development Department (2664) have, in conjunction with the Oil Recovery Technology Partnership, developed a Multi-Level Seismic Receiver (MLSR) for use in crosswell seismic surveys. The MLSR was designed and evaluated with the significant support of many industry partners in the oil exploration industry. The unit was designed to record and process superior quality seismic data operating in severe borehole environments, including high temperature (up to 200{degrees}C) and static pressure (10,000 psi). This development has utilized state-of-the-art technology in transducers, data acquisition, and real-time data communication and data processing. The mechanical design of the receiver has been carefully modeled and evaluated to insure excellent signal coupling into the receiver.

  10. Harmonic analysis and FPGA implementation of SHE controlled three phase CHB 11-level inverter in MV drives using deterministic and stochastic optimization techniques.

    PubMed

    Vesapogu, Joshi Manohar; Peddakotla, Sujatha; Kuppa, Seetha Rama Anjaneyulu

    2013-01-01

    With the advancements in semiconductor technology, high power medium voltage (MV) Drives are extensively used in numerous industrial applications. Challenging technical requirements of MV Drives is to control multilevel inverter (MLI) with less Total harmonic distortion (%THD) which satisfies IEEE standard 519-1992 harmonic guidelines and less switching losses. Among all modulation control strategies for MLI, Selective harmonic elimination (SHE) technique is one of the traditionally preferred modulation control technique at fundamental switching frequency with better harmonic profile. On the other hand, the equations which are formed by SHE technique are highly non-linear in nature, may exist multiple, single or even no solution at particular modulation index (MI). However, in some MV Drive applications, it is required to operate over a range of MI. Providing analytical solutions for SHE equations during the whole range of MI from 0 to 1, has been a challenging task for researchers. In this paper, an attempt is made to solve SHE equations by using deterministic and stochastic optimization methods and comparative harmonic analysis has been carried out. An effective algorithm which minimizes %THD with less computational effort among all optimization algorithms has been presented. To validate the effectiveness of proposed MPSO technique, an experiment is carried out on a low power proto type of three phase CHB 11- level Inverter using FPGA based Xilinx's Spartan -3A DSP Controller. The experimental results proved that MPSO technique has successfully solved SHE equations over all range of MI from 0 to 1, the %THD obtained over major range of MI also satisfies IEEE 519-1992 harmonic guidelines too. PMID:24010030

  11. Multi-level Expression Design Language: Requirement level (MEDL-R) system evaluation

    NASA Technical Reports Server (NTRS)

    1980-01-01

    An evaluation of the Multi-Level Expression Design Language Requirements Level (MEDL-R) system was conducted to determine whether it would be of use in the Goddard Space Flight Center Code 580 software development environment. The evaluation is based upon a study of the MEDL-R concept of requirement languages, the functions performed by MEDL-R, and the MEDL-R language syntax. Recommendations are made for changes to MEDL-R that would make it useful in the Code 580 environment.

  12. A noise delivery system for multi-animal multi-level whole body ototoxicity studies.

    PubMed

    Stubbs, John E; Slagley, Jeremy M; Reboulet, James E

    2015-11-01

    The Naval Medical Research Unit Dayton (NAMRU-D) at Wright-Patterson Air Force Base, Ohio, in conjunction with the U.S. Air Force, studied ototoxic effects of JP-8 in rats. NAMRU-D used a multi-chamber whole body exposure facility for up to 96 test animals and 32 control animals at different exposure levels. The objective was to design a noise delivery system that could provide a white noise source one octave band wide, centered at 8 kHz frequency, delivered from outside the exposure chambers. Sound pressure levels were required to be within ±2 dB at all exposure points within each chamber and within ±2 dB over a 6-h run. Electrodynamic shakers were used to produce input noise in exposure chambers by inducing vibration in chamber plenums. Distribution of sound pressure levels across exposure points was controlled within a ±1.5dB prediction interval (α = 0.05) or better. Stability at a central reference point was controlled over 6-h runs within a ±1 dB prediction interval (α = 0.05) or better. The final system allowed NAMRU-D to deliver noise and whole-body aerosol exposures to multiple animals at different levels simultaneously and study the effects that ototoxins may have on hearing loss. PMID:26627791

  13. Verify level control criteria for multi-level cell flash memories and their applications

    NASA Astrophysics Data System (ADS)

    Kim, Yongjune; Kim, Jaehong; Kong, Jun Jin; K Vijaya Kumar, B. V.; Li, Xin

    2012-12-01

    In 1 M-bit/cell multi-level cell (MLC) flash memories, it is more difficult to guarantee the reliability of data as M increases. The reason is that an M-bit/cell MLC has 2 M states whereas a single-level cell (SLC) has only two states. Hence, compared to SLC, the margin of MLC is reduced, thereby making it sensitive to a number of degradation mechanisms such as cell-to-cell interference and charge leakage. In flash memories, distances between 2 M states can be controlled by adjusting verify levels during incremental step pulse programming (ISPP). For high data reliability, the control of verify levels in ISPP is important because the bit error rate (BER) will be affected significantly by verify levels. As M increases, the verify level control will be more important and complex. In this article, we investigate two verify level control criteria for MLC flash memories. The first criterion is to minimize the overall BER and the second criterion is to make page BERs equal. The choice between these criteria relates to flash memory architecture, bits per cell, reliability, and speed performance. Considering these factors, we will discuss the strategy of verify level control in the hybrid solid state drives (SSD) which are composed of flash memories with different number of bits per cell.

  14. Comparison of Multiple Carrier Disposition PWM Techniques Applied for Multi-Level Shunt Active Filter

    NASA Astrophysics Data System (ADS)

    Kathalingam, Sebasthi Rani; Karantharaj, Porkumaran

    2012-07-01

    This work presents the simulation of a shunt active filter using seven-level cascaded inverter. The ultimate objective is to bring out the influence of multiple carrier level shifted PWM techniques on the performance of a shunt active filter. Classical disposition PWM techniques such as PD, POD and APOD have been used to generate the gating signals for the inverter active switches. A comparison is presented to substantiate the effect of these techniques in filtering. The comparison is made from the perspective of reduction in THD of source currents after filtering. For compensation current extraction synchronous detection method has been used. The harmonic reduction is achieved in source currents as well as source voltages.

  15. Multi-level molecular modelling for plasma medicine

    NASA Astrophysics Data System (ADS)

    Bogaerts, Annemie; Khosravian, Narjes; Van der Paal, Jonas; Verlackt, Christof C. W.; Yusupov, Maksudbek; Kamaraj, Balu; Neyts, Erik C.

    2016-02-01

    Modelling at the molecular or atomic scale can be very useful for obtaining a better insight in plasma medicine. This paper gives an overview of different atomic/molecular scale modelling approaches that can be used to study the direct interaction of plasma species with biomolecules or the consequences of these interactions for the biomolecules on a somewhat longer time-scale. These approaches include density functional theory (DFT), density functional based tight binding (DFTB), classical reactive and non-reactive molecular dynamics (MD) and united-atom or coarse-grained MD, as well as hybrid quantum mechanics/molecular mechanics (QM/MM) methods. Specific examples will be given for three important types of biomolecules, present in human cells, i.e. proteins, DNA and phospholipids found in the cell membrane. The results show that each of these modelling approaches has its specific strengths and limitations, and is particularly useful for certain applications. A multi-level approach is therefore most suitable for obtaining a global picture of the plasma–biomolecule interactions.

  16. Design of a Multi-Level/Analog Ferroelectric Memory Device

    NASA Technical Reports Server (NTRS)

    MacLeod, Todd C.; Phillips, Thomas A.; Ho, Fat D.

    2006-01-01

    Increasing the memory density and utilizing the dove1 characteristics of ferroelectric devices is important in making ferroelectric memory devices more desirable to the consumer. This paper describes a design that allows multiple levels to be stored in a ferroelectric based memory cell. It can be used to store multiple bits or analog values in a high speed nonvolatile memory. The design utilizes the hysteresis characteristic of ferroelectric transistors to store an analog value in the memory cell. The design also compensates for the decay of the polarization of the ferroelectric material over time. This is done by utilizing a pair of ferroelectric transistors to store the data. One transistor is used as a reference to determine the amount of decay that has occurred since the pair was programmed. The second transistor stores the analog value as a polarization value between zero and saturated. The design allows digital data to be stored as multiple bits in each memory cell. The number of bits per cell that can be stored will vary with the decay rate of the ferroelectric transistors and the repeatability of polarization between transistors. It is predicted that each memory cell may be able to store 8 bits or more. The design is based on data taken from actual ferroelectric transistors. Although the circuit has not been fabricated, a prototype circuit is now under construction. The design of this circuit is different than multi-level FLASH or silicon transistor circuits. The differences between these types of circuits are described in this paper. This memory design will be useful because it allows higher memory density, compensates for the environmental and ferroelectric aging processes, allows analog values to be directly stored in memory, compensates for the thermal and radiation environments associated with space operations, and relies only on existing technologies.

  17. Level set methods for meteorological multi scale problems

    NASA Astrophysics Data System (ADS)

    Dietze, Eckhard; Stevens, Bjorn; Mellado, Juan Pedro; Peters, Norbert; Schmidt, Heiko

    2010-05-01

    Reasonable modeling of shallow cumuliform and stratocumulus convection is important to both weather and climate forecast. Indeed recent work suggests that shallow cumulus convection is the major point of departure among climate-model representations of climate sensitivity, and a principal means by which the atmospheric aerosol imprints itself on larger-scale circulations. Unfortunately our understanding of these clouds is limited, in part, by our ability to simulate them with great confidence or fidelity. A standard tool for understanding both the dry and the moist boundary layer behavior is Large Eddy Simulation (LES), but fundamental issues emerge in quantities of interest (e.g. exact boundary layer heights or Albedo). A reason for this is that current LES cannot resolve the interface physics due to insufficient grid resolution. Even elaborate physically based subgrid models are numerically smeared out, so that a distinction between numerical (e.g. discretization errors) and physical effects (e.g. entrainment) is impossible. Here, we focus on the numerical effects and explain a heterogeneous multi scale concept for the modeling of Stratocumulus clouds that has been successfully used in combustion science. The cloud top interface which is driven by large scale motions is explicitly followed (tracked) using a level set ansatz. In parallel we solve the underlying flow equations in a finite volume sense. The level set and the flow solutions are coupled via an approach called in-cell-reconstruction. The approach keeps an option to include small scale processes like e.g. entrainment via (super-) parameterizations in a modular fashion.

  18. Multi-Level Modeling of Dyadic Data in Sport Sciences: Conceptual, Statistical, and Practical Issues

    ERIC Educational Resources Information Center

    Gaudreau, Patrick; Fecteau, Marie-Claude; Perreault, Stephane

    2010-01-01

    The goal of this article is to present a series of conceptual, statistical, and practical issues in the modeling of multi-level dyadic data. Distinctions are made between distinguishable and undistinguishable dyads and several types of independent variables modeled at the dyadic level of analysis. Multi-level modeling equations are explained in a…

  19. Multi-Level Modeling of Dyadic Data in Sport Sciences: Conceptual, Statistical, and Practical Issues

    ERIC Educational Resources Information Center

    Gaudreau, Patrick; Fecteau, Marie-Claude; Perreault, Stephane

    2010-01-01

    The goal of this article is to present a series of conceptual, statistical, and practical issues in the modeling of multi-level dyadic data. Distinctions are made between distinguishable and undistinguishable dyads and several types of independent variables modeled at the dyadic level of analysis. Multi-level modeling equations are explained in a

  20. Antibiotic resistance shaping multi-level population biology of bacteria.

    PubMed

    Baquero, Fernando; Tedim, Ana P; Coque, Teresa M

    2013-01-01

    Antibiotics have natural functions, mostly involving cell-to-cell signaling networks. The anthropogenic production of antibiotics, and its release in the microbiosphere results in a disturbance of these networks, antibiotic resistance tending to preserve its integrity. The cost of such adaptation is the emergence and dissemination of antibiotic resistance genes, and of all genetic and cellular vehicles in which these genes are located. Selection of the combinations of the different evolutionary units (genes, integrons, transposons, plasmids, cells, communities and microbiomes, hosts) is highly asymmetrical. Each unit of selection is a self-interested entity, exploiting the higher hierarchical unit for its own benefit, but in doing so the higher hierarchical unit might acquire critical traits for its spread because of the exploitation of the lower hierarchical unit. This interactive trade-off shapes the population biology of antibiotic resistance, a composed-complex array of the independent "population biologies." Antibiotics modify the abundance and the interactive field of each of these units. Antibiotics increase the number and evolvability of "clinical" antibiotic resistance genes, but probably also many other genes with different primary functions but with a resistance phenotype present in the environmental resistome. Antibiotics influence the abundance, modularity, and spread of integrons, transposons, and plasmids, mostly acting on structures present before the antibiotic era. Antibiotics enrich particular bacterial lineages and clones and contribute to local clonalization processes. Antibiotics amplify particular genetic exchange communities sharing antibiotic resistance genes and platforms within microbiomes. In particular human or animal hosts, the microbiomic composition might facilitate the interactions between evolutionary units involved in antibiotic resistance. The understanding of antibiotic resistance implies expanding our knowledge on multi-level population biology of bacteria. PMID:23508522

  1. Antibiotic resistance shaping multi-level population biology of bacteria

    PubMed Central

    Baquero, Fernando; Tedim, Ana P.; Coque, Teresa M.

    2013-01-01

    Antibiotics have natural functions, mostly involving cell-to-cell signaling networks. The anthropogenic production of antibiotics, and its release in the microbiosphere results in a disturbance of these networks, antibiotic resistance tending to preserve its integrity. The cost of such adaptation is the emergence and dissemination of antibiotic resistance genes, and of all genetic and cellular vehicles in which these genes are located. Selection of the combinations of the different evolutionary units (genes, integrons, transposons, plasmids, cells, communities and microbiomes, hosts) is highly asymmetrical. Each unit of selection is a self-interested entity, exploiting the higher hierarchical unit for its own benefit, but in doing so the higher hierarchical unit might acquire critical traits for its spread because of the exploitation of the lower hierarchical unit. This interactive trade-off shapes the population biology of antibiotic resistance, a composed-complex array of the independent “population biologies.” Antibiotics modify the abundance and the interactive field of each of these units. Antibiotics increase the number and evolvability of “clinical” antibiotic resistance genes, but probably also many other genes with different primary functions but with a resistance phenotype present in the environmental resistome. Antibiotics influence the abundance, modularity, and spread of integrons, transposons, and plasmids, mostly acting on structures present before the antibiotic era. Antibiotics enrich particular bacterial lineages and clones and contribute to local clonalization processes. Antibiotics amplify particular genetic exchange communities sharing antibiotic resistance genes and platforms within microbiomes. In particular human or animal hosts, the microbiomic composition might facilitate the interactions between evolutionary units involved in antibiotic resistance. The understanding of antibiotic resistance implies expanding our knowledge on multi-level population biology of bacteria. PMID:23508522

  2. Assessing intervention fidelity in a multi-level, multi-component, multi-site program: the Children's Healthy Living (CHL) program.

    PubMed

    Butel, Jean; Braun, Kathryn L; Novotny, Rachel; Acosta, Mark; Castro, Rose; Fleming, Travis; Powers, Julianne; Nigg, Claudio R

    2015-12-01

    Addressing complex chronic disease prevention, like childhood obesity, requires a multi-level, multi-component culturally relevant approach with broad reach. Models are lacking to guide fidelity monitoring across multiple levels, components, and sites engaged in such interventions. The aim of this study is to describe the fidelity-monitoring approach of The Children's Healthy Living (CHL) Program, a multi-level multi-component intervention in five Pacific jurisdictions. A fidelity-monitoring rubric was developed. About halfway during the intervention, community partners were randomly selected and interviewed independently by local CHL staff and by Coordinating Center representatives to assess treatment fidelity. Ratings were compared and discussed by local and Coordinating Center staff. There was good agreement between the teams (Kappa = 0.50, p < 0.001), and intervention improvement opportunities were identified through data review and group discussion. Fidelity for the multi-level, multi-component, multi-site CHL intervention was successfully assessed, identifying adaptations as well as ways to improve intervention delivery prior to the end of the intervention. PMID:26622918

  3. PHIL Inverter Test Report: Analysis of High-Penetration Levels of PV into the Distribution Grid in California, March 12 - March 16, 2012

    SciTech Connect

    Kromer, M.

    2013-06-01

    This report describes power hardware-in-the-loop simulation testing of a 500 kW Satcon photovoltaic inverter, conducted at the Center for Advanced Power Systems at Florida State University from March 12th through March 16th, 2012. Testing was led by a team from the National Renewable Energy Laboratory. The report reviews the results of data captured during the course of testing. The tests were used to demonstrate operation of and gather data from the inverter in a simulated operational environment. Testing demonstrated the ability of the inverter to operate in either a Power Factor Control Mode or a Reactive Power Command Mode, and to respond to real power limits.

  4. Hybrid triple-level-cell/multi-level-cell NAND flash storage array with chip exchangeable method

    NASA Astrophysics Data System (ADS)

    Hachiya, Shogo; Johguchi, Koh; Miyaji, Kousuke; Takeuchi, Ken

    2014-01-01

    This paper proposes a mix-and-match design method for triple level cell (TLC)/multi level cell (MLC) NAND flash hybrid and exchangeable storage arrays. A TLC-NAND flash provides an low cost and high capacity memory solution. However the reliability and access latency of TLC NAND flash are degraded from MLC NAND flash. Additionally, the block unit write is preferable for TLC NAND flash since the write order is complicated due to narrow data margin and write disturbance. The proposed solution combines TLC and MLC NAND flash memories for a storage array. To reduce access to TLC NAND flash, the stored data is screened and only the static frozen data are stored into TLC NAND flash with a Round-Robin frozen data collection algorithm (RR-FDCA). Furthermore, the proposed chip exchanging method extends the solid-state drive (SSD) lifetime without system suspending. As a result, in spite of moderate characteristics of TLC NAND flash, the proposed storage array can achieve 29% write energy saving and 56% write performance enhancement with 17% cost reduction, compared with the conventional MLC-only SSD.

  5. Multi-floor cascading ferroelectric nanostructures: multiple data writing-based multi-level non-volatile memory devices.

    PubMed

    Hyun, Seung; Kwon, Owoong; Lee, Bom-Yi; Seol, Daehee; Park, Beomjin; Lee, Jae Yong; Lee, Ju Hyun; Kim, Yunseok; Kim, Jin Kon

    2016-01-01

    Multiple data writing-based multi-level non-volatile memory has gained strong attention for next-generation memory devices to quickly accommodate an extremely large number of data bits because it is capable of storing multiple data bits in a single memory cell at once. However, all previously reported devices have failed to store a large number of data bits due to the macroscale cell size and have not allowed fast access to the stored data due to slow single data writing. Here, we introduce a novel three-dimensional multi-floor cascading polymeric ferroelectric nanostructure, successfully operating as an individual cell. In one cell, each floor has its own piezoresponse and the piezoresponse of one floor can be modulated by the bias voltage applied to the other floor, which means simultaneously written data bits in both floors can be identified. This could achieve multi-level memory through a multiple data writing process. PMID:26695561

  6. Multi-floor cascading ferroelectric nanostructures: multiple data writing-based multi-level non-volatile memory devices

    NASA Astrophysics Data System (ADS)

    Hyun, Seung; Kwon, Owoong; Lee, Bom-Yi; Seol, Daehee; Park, Beomjin; Lee, Jae Yong; Lee, Ju Hyun; Kim, Yunseok; Kim, Jin Kon

    2016-01-01

    Multiple data writing-based multi-level non-volatile memory has gained strong attention for next-generation memory devices to quickly accommodate an extremely large number of data bits because it is capable of storing multiple data bits in a single memory cell at once. However, all previously reported devices have failed to store a large number of data bits due to the macroscale cell size and have not allowed fast access to the stored data due to slow single data writing. Here, we introduce a novel three-dimensional multi-floor cascading polymeric ferroelectric nanostructure, successfully operating as an individual cell. In one cell, each floor has its own piezoresponse and the piezoresponse of one floor can be modulated by the bias voltage applied to the other floor, which means simultaneously written data bits in both floors can be identified. This could achieve multi-level memory through a multiple data writing process.Multiple data writing-based multi-level non-volatile memory has gained strong attention for next-generation memory devices to quickly accommodate an extremely large number of data bits because it is capable of storing multiple data bits in a single memory cell at once. However, all previously reported devices have failed to store a large number of data bits due to the macroscale cell size and have not allowed fast access to the stored data due to slow single data writing. Here, we introduce a novel three-dimensional multi-floor cascading polymeric ferroelectric nanostructure, successfully operating as an individual cell. In one cell, each floor has its own piezoresponse and the piezoresponse of one floor can be modulated by the bias voltage applied to the other floor, which means simultaneously written data bits in both floors can be identified. This could achieve multi-level memory through a multiple data writing process. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07377d

  7. Multi-party d-Level Quantum Secret Sharing Scheme

    NASA Astrophysics Data System (ADS)

    Xiao, Heling; Gao, Jingliang

    2013-06-01

    We develop a multiparty quantum secret sharing (QSS) scheme of classical messages based on arbitrary dimensional multi-particle Greenberger-Horne-Zeilinger (GHZ) states. This scheme can be implemented using only local operations, e.g. generalized Z gate and Hadamard gate, and classical communication (LOCC) between participants. The security of the present scheme against exterior eavesdropping and interior dishonest party has been analyzed and confirmed. Moreover, we discuss the possibility of successful sharing of classical messages in the realistic situation where our QSS scheme is carried out in generalized Pauli channels.

  8. Multi-level scanning method for defect inspection

    DOEpatents

    Bokor, Jeffrey (Oakland, CA); Jeong, Seongtae (Richmond, CA)

    2002-01-01

    A method for performing scanned defect inspection of a collection of contiguous areas using a specified false-alarm-rate and capture-rate within an inspection system that has characteristic seek times between inspection locations. The multi-stage method involves setting an increased false-alarm-rate for a first stage of scanning, wherein subsequent stages of scanning inspect only the detected areas of probable defects at lowered values for the false-alarm-rate. For scanning inspection operations wherein the seek time and area uncertainty is favorable, the method can substantially increase inspection throughput.

  9. Switching Characteristics of Ferroelectric Transistor Inverters

    NASA Technical Reports Server (NTRS)

    Laws, Crystal; Mitchell, Coey; MacLeod, Todd C.; Ho, Fat D.

    2010-01-01

    This paper presents the switching characteristics of an inverter circuit using a ferroelectric field effect transistor, FeFET. The propagation delay time characteristics, phl and plh are presented along with the output voltage rise and fall times, rise and fall. The propagation delay is the time-delay between the V50% transitions of the input and output voltages. The rise and fall times are the times required for the output voltages to transition between the voltage levels V10% and V90%. Comparisons are made between the MOSFET inverter and the ferroelectric transistor inverter.

  10. Integrated Inverter And Battery Charger

    NASA Technical Reports Server (NTRS)

    Rippel, Wally E.

    1988-01-01

    Circuit combines functions of dc-to-ac inversion (for driving ac motor in battery-powered vehicle) and ac-to-dc conversion (for charging battery from ac line when vehicle not in use). Automatically adapts to either mode. Design of integrated inverter/charger eliminates need for duplicate components, saves space, reduces weight and cost of vehicle. Advantages in other applications : load-leveling systems, standby ac power systems, and uninterruptible power supplies.

  11. Exploring the impact of different multi-level measures of physician communities in patient-centric care networks on healthcare outcomes: A multi-level regression approach.

    PubMed

    Uddin, Shahadat

    2016-01-01

    A patient-centric care network can be defined as a network among a group of healthcare professionals who provide treatments to common patients. Various multi-level attributes of the members of this network have substantial influence to its perceived level of performance. In order to assess the impact different multi-level attributes of patient-centric care networks on healthcare outcomes, this study first captured patient-centric care networks for 85 hospitals using health insurance claim dataset. From these networks, this study then constructed physician collaboration networks based on the concept of patient-sharing network among physicians. A multi-level regression model was then developed to explore the impact of different attributes that are organised at two levels on hospitalisation cost and hospital length of stay. For Level-1 model, the average visit per physician significantly predicted both hospitalisation cost and hospital length of stay. The number of different physicians significantly predicted only the hospitalisation cost, which has significantly been moderated by age, gender and Comorbidity score of patients. All Level-1 findings showed significance variance across physician collaboration networks having different community structure and density. These findings could be utilised as a reflective measure by healthcare decision makers. Moreover, healthcare managers could consider them in developing effective healthcare environments. PMID:26842548

  12. Exploring the impact of different multi-level measures of physician communities in patient-centric care networks on healthcare outcomes: A multi-level regression approach

    PubMed Central

    Uddin, Shahadat

    2016-01-01

    A patient-centric care network can be defined as a network among a group of healthcare professionals who provide treatments to common patients. Various multi-level attributes of the members of this network have substantial influence to its perceived level of performance. In order to assess the impact different multi-level attributes of patient-centric care networks on healthcare outcomes, this study first captured patient-centric care networks for 85 hospitals using health insurance claim dataset. From these networks, this study then constructed physician collaboration networks based on the concept of patient-sharing network among physicians. A multi-level regression model was then developed to explore the impact of different attributes that are organised at two levels on hospitalisation cost and hospital length of stay. For Level-1 model, the average visit per physician significantly predicted both hospitalisation cost and hospital length of stay. The number of different physicians significantly predicted only the hospitalisation cost, which has significantly been moderated by age, gender and Comorbidity score of patients. All Level-1 findings showed significance variance across physician collaboration networks having different community structure and density. These findings could be utilised as a reflective measure by healthcare decision makers. Moreover, healthcare managers could consider them in developing effective healthcare environments. PMID:26842548

  13. GROUND WATER MONITORING AND SAMPLING: MULTI-LEVEL VERSUS TRADITIONAL METHODS – WHAT’S WHAT?

    EPA Science Inventory

    Recent studies have been conducted to evaluate different sampling techniques for determining VOC concentrations in groundwater. Samples were obtained using multi-level and traditional sampling techniques in three monitoring wells at the Raymark Superfund site in Stratford, CT. Ve...

  14. GROUND WATER MONITORING AND SAMPLING: MULTI-LEVEL VERSUS TRADITIONAL METHODS WHATS WHAT?

    EPA Science Inventory

    Recent studies have been conducted to evaluate different sampling techniques for determining VOC concentrations in groundwater. Samples were obtained using multi-level and traditional sampling techniques in three monitoring wells at the Raymark Superfund site in Stratford, CT. Ve...

  15. A Multi-Level Perspective on Community Employment Problems for Adults with Mental Retardation.

    ERIC Educational Resources Information Center

    Hanley-Maxwell, Cheryl; And Others

    1989-01-01

    Introduces multi-level viewpoint on community employment problems for persons with mental retardation. Calls for reframing of the questions asked and advocates broader consideration to planning interventions at the small group, organizational, and institutional and community levels, as well as the individual level. Makes proposals for new

  16. Improved inverted Stepanov apparatus

    NASA Technical Reports Server (NTRS)

    Berkman, S.; Temple, H. E.

    1979-01-01

    Modifications in inverted Stepanov process improve heat transfer and energy efficiency in growing silicon ribbon crystals. Using system, silicon is directly heated by induction, minimizing heat transfer and contamination problems.

  17. Reliable inverter systems

    NASA Technical Reports Server (NTRS)

    Nagano, S.

    1979-01-01

    Base driver with common-load-current feedback protects paralleled inverter systems from open or short circuits. Circuit eliminates total system oscillation that can occur in conventional inverters because of open circuit in primary transformer winding. Common feedback signal produced by functioning modules forces operating frequency of failed module to coincide with clock drive so module resumes normal operating frequency in spite of open circuit.

  18. Multi-leveled objects: color as a case study

    PubMed Central

    Albertazzi, Liliana; Poli, Roberto

    2014-01-01

    The paper presents color as a case study for the analysis of phenomena that pertain to several levels of reality and are typically framed by different sciences and disciplines. Color, in fact, is studied by physics, biology, phenomenology, and esthetics, among others. Our thesis is that color is a different entity for each level of reality, and that for this reason color generates different observables in the epistemologies of the different sciences. By analyzing color as a paradigmatic case of an entity naturally spreading over different levels of reality, the paper raises the question as to whether making explicit the usually implicit ontological assumptions embedded within the different observables exploited by the different sciences may eventually clarify some of the difficulties of developing a comprehensive theory of color. PMID:25071616

  19. Multi-level damage detection with nonlinear ultrasonic methods

    NASA Astrophysics Data System (ADS)

    Matlack, Kathryn H.; Kim, Jin-Yeon; Jacobs, Laurence J.; Qu, Jianmin

    2013-01-01

    The nonlinear ultrasonic method of second harmonic generation is used to detect multiple levels of damage on a single specimen. There is a breadth of research in the literature that measures the second harmonic and the resulting nonlinear parameter to monitor increasing amounts of uniform damage, but for this method to be applicable as an in situ technique, it must be able to scan an area of a structure with varying amounts of damage over a region. To investigate this, an aluminum alloy sample is shot-peened to two intensity levels along its length, to produce different sections of cold work and residual stress as a function of spatial location. Previous research has shown that the residual stress and cold work introduced in a material from shot peening causes an increase in the nonlinear parameter. Rayleigh waves are generated in the sample and the first and second harmonic amplitudes are measured at increasing propagation distances that encompass an undamaged section and two sections, each with different levels of shot peening. Results show that the nonlinear parameter increases as the Rayleigh wedge sensor is scanned over the shot peening sections.

  20. Multi-level functionality of social media in the aftermath of the Great East Japan Earthquake.

    PubMed

    Jung, Joo-Young; Moro, Munehito

    2014-07-01

    This study examines the multi-level functionalities of social media in the aftermath of the Great East Japan Earthquake of 11 March 2011. Based on a conceptual model of multi-level story flows of social media (Jung and Moro, 2012), the study analyses the multiple functionalities that were ascribed to social media by individuals, organisations, and macro-level social systems (government and the mass media) after the earthquake. Based on survey data, a review of Twitter timelines and secondary sources, the authors derive five functionalities of social media: interpersonal communications with others (micro level); channels for local governments; organisations and local media (meso level); channels for mass media (macro level); information sharing and gathering (cross level); and direct channels between micro-/meso- and macro-level agents. The study sheds light on the future potential of social media in disaster situations and suggests how to design an effective communication network to prepare for emergency situations. PMID:24905811

  1. 49 CFR Figure 2a to Subpart B of... - Example of an Intermediate Level Seating Area of a Multi-Level Car Complying With Window Location...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Example of an Intermediate Level Seating Area of a Multi-Level Car Complying With Window Location Requirements-§§ 238.113 and 238.114 2A Figure 2A to... Intermediate Level Seating Area of a Multi-Level Car Complying With Window Location Requirements 238.113...

  2. 49 CFR Figure 2b to Subpart B of... - Example of an Intermediate Level Seating Area of a Multi-Level Car Complying With Window Location...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Example of an Intermediate Level Seating Area of a Multi-Level Car Complying With Window Location Requirements-§§ 238.113 and 238.114 2B Figure 2B to... Intermediate Level Seating Area of a Multi-Level Car Complying With Window Location Requirements 238.113...

  3. Multi-interface Level Sensors and New Development in Monitoring and Control of Oil Separators

    PubMed Central

    Bukhari, Syed Faisal Ahmed; Yang, Wuqiang

    2006-01-01

    In the oil industry, huge saving may be made if suitable multi-interface level measurement systems are employed for effectively monitoring crude oil separators and efficient control of their operation. A number of techniques, e.g. externally mounted displacers, differential pressure transmitters and capacitance rod devices, have been developed to measure the separation process with gas, oil, water and other components. Because of the unavailability of suitable multi-interface level measurement systems, oil separators are currently operated by the trial-and-error approach. In this paper some conventional techniques, which have been used for level measurement in industry, and new development are discussed.

  4. Multi-level of Fidelity Multi-Disciplinary Design Optimization of Small, Solid-Propellant Launch Vehicles

    NASA Astrophysics Data System (ADS)

    Roshanian, Jafar; Jodei, Jahangir; Mirshams, Mehran; Ebrahimi, Reza; Mirzaee, Masood

    A new automated multi-level of fidelity Multi-Disciplinary Design Optimization (MDO) methodology has been developed at the MDO Laboratory of K.N. Toosi University of Technology. This paper explains a new design approach by formulation of developed disciplinary modules. A conceptual design for a small, solid-propellant launch vehicle was considered at two levels of fidelity structure. Low and medium level of fidelity disciplinary codes were developed and linked. Appropriate design and analysis codes were defined according to their effect on the conceptual design process. Simultaneous optimization of the launch vehicle was performed at the discipline level and system level. Propulsion, aerodynamics, structure and trajectory disciplinary codes were used. To reach the minimum launch weight, the Low LoF code first searches the whole design space to achieve the mission requirements. Then the medium LoF code receives the output of the low LoF and gives a value near the optimum launch weight with more details and higher fidelity.

  5. Global Multi-Level Analysis of the Scientific Food Web'

    PubMed Central

    Mazloumian, Amin; Helbing, Dirk; Lozano, Sergi; Light, Robert P.; Brner, Katy

    2013-01-01

    We introduce a network-based index analyzing excess scientific production and consumption to perform a comprehensive global analysis of scholarly knowledge production and diffusion on the level of continents, countries, and cities. Compared to measures of scientific production and consumption such as number of publications or citation rates, our network-based citation analysis offers a more differentiated picture of the ecosystem of science. Quantifying knowledge flows between 2000 and 2009, we identify global sources and sinks of knowledge production. Our knowledge flow index reveals, where ideas are born and consumed, thereby defining a global scientific food web. While Asia is quickly catching up in terms of publications and citation rates, we find that its dependence on knowledge consumption has further increased. PMID:23378902

  6. Global Multi-Level Analysis of the Scientific Food Web'

    NASA Astrophysics Data System (ADS)

    Mazloumian, Amin; Helbing, Dirk; Lozano, Sergi; Light, Robert P.; Brner, Katy

    2013-01-01

    We introduce a network-based index analyzing excess scientific production and consumption to perform a comprehensive global analysis of scholarly knowledge production and diffusion on the level of continents, countries, and cities. Compared to measures of scientific production and consumption such as number of publications or citation rates, our network-based citation analysis offers a more differentiated picture of the `ecosystem of science'. Quantifying knowledge flows between 2000 and 2009, we identify global sources and sinks of knowledge production. Our knowledge flow index reveals, where ideas are born and consumed, thereby defining a global `scientific food web'. While Asia is quickly catching up in terms of publications and citation rates, we find that its dependence on knowledge consumption has further increased.

  7. Parametric Multi-Level Tiling of Imperfectly Nested Loops

    SciTech Connect

    Hartono, Albert; Baskaran, Muthu M.; Bastoul, Cedric; Cohen, Albert; Krishnamoorthy, Sriram; Norris, Boyana; Ramanujam, J.; Sadayappan, Ponnuswamy

    2009-05-18

    Tiling is a critical loop transformation for generating high-performance code on modern architectures. Efficient generation of multilevel tiled code is essential to exploit several levels of parallelism and/or to maximize data reuse in deep memory hierarchies. Tiled loops with parameterized tile sizes (not compile time constants) facilitate runtime feedback and dynamic optimizations used in iterative compilation and automatic tuning. The existing parametric multilevel tiling approach has focused on transformation for perfectly nested loops, where all assignment statements are contained inside the innermost loop of a loop nest. Previous solutions to tiling for imperfect loop nests are limited to the case where tile sizes are fixed. In this paper, we present an approach to parameterized multilevel tiling for imperfectly nested loops. Our tiling algorithm generates loops that iterate over full rectangular tiles that are amenable for potential compiler optimizations such as register tiling. Experimental results using a number of computational benchmarks demonstrate the effectiveness of our tiling approach.

  8. A Multi-Compartment Segmentation Framework With Homeomorphic Level Sets

    PubMed Central

    Fan, Xian; Bazin, Pierre-Louis; Prince, Jerry L.

    2011-01-01

    The simultaneous segmentation of multiple objects is an important problem in many imaging and computer vision applications. Various extensions of level set segmentation techniques to multiple objects have been proposed; however, no one method maintains object relationships, preserves topology, is computationally efficient, and provides an object-dependent internal and external force capability. In this paper, a framework for segmenting multiple objects that permits different forces to be applied to different boundaries while maintaining object topology and relationships is presented. Because of this framework, the segmentation of multiple objects each with multiple compartments is supported, and no overlaps or vacuums are generated. The computational complexity of this approach is independent of the number of objects to segment, thereby permitting the simultaneous segmentation of a large number of components. The properties of this approach and comparisons to existing methods are shown using a variety of images, both synthetic and real. PMID:23223164

  9. Bacteriorhodopsin-based multi-level optical security features

    NASA Astrophysics Data System (ADS)

    Hampp, N.; Neebe, M.

    2006-02-01

    Bacteriorhodopsin (BR) is a crystalline photochromic protein which shows an astonishing stability towards chemical and thermal degradation. This material is used in a variety of applications which have been developed, among them photochromic color-changes, optical data storage and molecular traceability of the material. Integration of all three security levels in a document will be shown. One year lasting field tests have proven the stability of the system in daily use. First applications of polarization encoded data storage and data encryption have been realized successfully. The development of BR-based security features will be reviewed and newer developments will be presented, among them individualized computer generated holograms and the development of ink-jet inks. The data-storage capabilities of the biomaterial BR have been further developed and now visual detectable as well as visual non-detectable storage processes are available. The molecular mechanisms of the data storage process will be presented.

  10. Multi-level adaptive finite element methods. 1: Variation problems

    NASA Technical Reports Server (NTRS)

    Brandt, A.

    1979-01-01

    A general numerical strategy for solving partial differential equations and other functional problems by cycling between coarser and finer levels of discretization is described. Optimal discretization schemes are provided together with very fast general solvers. It is described in terms of finite element discretizations of general nonlinear minimization problems. The basic processes (relaxation sweeps, fine-grid-to-coarse-grid transfers of residuals, coarse-to-fine interpolations of corrections) are directly and naturally determined by the objective functional and the sequence of approximation spaces. The natural processes, however, are not always optimal. Concrete examples are given and some new techniques are reviewed. Including the local truncation extrapolation and a multilevel procedure for inexpensively solving chains of many boundary value problems, such as those arising in the solution of time-dependent problems.

  11. A Bayesian Multi-Level Factor Analytic Model of Consumer Price Sensitivities across Categories

    ERIC Educational Resources Information Center

    Duvvuri, Sri Devi; Gruca, Thomas S.

    2010-01-01

    Identifying price sensitive consumers is an important problem in marketing. We develop a Bayesian multi-level factor analytic model of the covariation among household-level price sensitivities across product categories that are substitutes. Based on a multivariate probit model of category incidence, this framework also allows the researcher to

  12. A Bayesian Multi-Level Factor Analytic Model of Consumer Price Sensitivities across Categories

    ERIC Educational Resources Information Center

    Duvvuri, Sri Devi; Gruca, Thomas S.

    2010-01-01

    Identifying price sensitive consumers is an important problem in marketing. We develop a Bayesian multi-level factor analytic model of the covariation among household-level price sensitivities across product categories that are substitutes. Based on a multivariate probit model of category incidence, this framework also allows the researcher to…

  13. Readable English for Hearing-Impaired Students: Multi-Level Guidelines for Linguistically Controlled Reading Materials.

    ERIC Educational Resources Information Center

    Decker, Nan; And Others

    Developed by the Multi-level Captioning Project, the manual provides guidelines for linguistically controlling reading materials for the deaf. An introduction describes the three proposed reading levels based on difficulty of vocabulary, syntax, and inference. Chapter 1, on vocabulary, considers word list sources, guidelines for controlling

  14. Multi-Level Model of Contextual Factors and Teachers' Assessment Practices: An Integrative Review of Research

    ERIC Educational Resources Information Center

    Fulmer, Gavin W.; Lee, Iris C. H.; Tan, Kelvin H. K.

    2015-01-01

    We present a multi-level model of contextual factors that may influence teachers' assessment practices, and use this model in a selected review of existing literature on teachers' assessment knowledge, views and conceptions with respect to these contextual factors. Adapting Kozma's model, we distinguish three levels of influence on teachers'

  15. Multi-level hot zone identification for pedestrian safety.

    PubMed

    Lee, Jaeyoung; Abdel-Aty, Mohamed; Choi, Keechoo; Huang, Helai

    2015-03-01

    According to the National Highway Traffic Safety Administration (NHTSA), while fatalities from traffic crashes have decreased, the proportion of pedestrian fatalities has steadily increased from 11% to 14% over the past decade. This study aims at identifying two zonal levels factors. The first is to identify hot zones at which pedestrian crashes occurs, while the second are zones where crash-involved pedestrians came from. Bayesian Poisson lognormal simultaneous equation spatial error model (BPLSESEM) was estimated and revealed significant factors for the two target variables. Then, PSIs (potential for safety improvements) were computed using the model. Subsequently, a novel hot zone identification method was suggested to combine both hot zones from where vulnerable pedestrians originated with hot zones where many pedestrian crashes occur. For the former zones, targeted safety education and awareness campaigns can be provided as countermeasures whereas area-wide engineering treatments and enforcement may be effective safety treatments for the latter ones. Thus, it is expected that practitioners are able to suggest appropriate safety treatments for pedestrian crashes using the method and results from this study. PMID:25603547

  16. Resonant snubber inverter

    DOEpatents

    Lai, Jih-Sheng (Knoxville, TN); Young, Sr., Robert W. (Oak Ridge, TN); Chen, Daoshen (Knoxville, TN); Scudiere, Matthew B. (Oak Ridge, TN); Ott, Jr., George W. (Knoxville, TN); White, Clifford P. (Knoxville, TN); McKeever, John W. (Oak Ridge, TN)

    1997-01-01

    A resonant, snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the main inverter switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter.

  17. Resonant snubber inverter

    DOEpatents

    Lai, J.S.; Young, R.W. Sr.; Chen, D.; Scudiere, M.B.; Ott, G.W. Jr.; White, C.P.; McKeever, J.W.

    1997-06-24

    A resonant, snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the main inverter switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter. 14 figs.

  18. Equalizer design for clock recovery based on multi-level optical disk using signal waveform modulation

    NASA Astrophysics Data System (ADS)

    Shao, Meng; Pei, Jing; Yang, Bo

    2013-12-01

    With smaller pits and lands in multi-level optical disks using signal waveform modulation than those in DVD disks, the ISI and nonlinear attenuation of the read-out signal become more serious. One ordinary way is using an equalizer at sample rate 1/T, we proposed one method of designing the equalizer in fixed sample rate with digital interpolation. According to the analysis of the multi-level optical disk channel, we get the target frequency-response cure and implement it with seven order FIR filter. From the result of the read out experiment with multi-level optical disk, the clock of the RF signal could be recovered with the proposed equalizer.

  19. Multi-level manual and autonomous control superposition for intelligent telerobot

    NASA Technical Reports Server (NTRS)

    Hirai, Shigeoki; Sato, T.

    1989-01-01

    Space telerobots are recognized to require cooperation with human operators in various ways. Multi-level manual and autonomous control superposition in telerobot task execution is described. The object model, the structured master-slave manipulation system, and the motion understanding system are proposed to realize the concept. The object model offers interfaces for task level and object level human intervention. The structured master-slave manipulation system offers interfaces for motion level human intervention. The motion understanding system maintains the consistency of the knowledge through all the levels which supports the robot autonomy while accepting the human intervention. The superposing execution of the teleoperational task at multi-levels realizes intuitive and robust task execution for wide variety of objects and in changeful environment. The performance of several examples of operating chemical apparatuses is shown.

  20. Squeezed light from multi-level closed-cycling atomic systems

    NASA Technical Reports Server (NTRS)

    Xiao, Min; Zhu, Yi-Fu

    1994-01-01

    Amplitude squeezing is calculated for multi-level closed-cycling atomic systems. These systems can last without atomic population inversion in any atomic bases. Maximum squeezing is obtained for the parameters in the region of lasing without inversion. A practical four-level system and an ideal three-level system are presented. The latter system is analyzed in some detail and the mechanism of generating amplitude squeezing is discussed.

  1. A multi-level solution algorithm for steady-state Markov chains

    NASA Technical Reports Server (NTRS)

    Horton, Graham; Leutenegger, Scott T.

    1993-01-01

    A new iterative algorithm, the multi-level algorithm, for the numerical solution of steady state Markov chains is presented. The method utilizes a set of recursively coarsened representations of the original system to achieve accelerated convergence. It is motivated by multigrid methods, which are widely used for fast solution of partial differential equations. Initial results of numerical experiments are reported, showing significant reductions in computation time, often an order of magnitude or more, relative to the Gauss-Seidel and optimal SOR algorithms for a variety of test problems. The multi-level method is compared and contrasted with the iterative aggregation-disaggregation algorithm of Takahashi.

  2. Changing drug users' risk environments: peer health advocates as multi-level community change agents.

    PubMed

    Weeks, Margaret R; Convey, Mark; Dickson-Gomez, Julia; Li, Jianghong; Radda, Kim; Martinez, Maria; Robles, Eduardo

    2009-06-01

    Peer delivered, social oriented HIV prevention intervention designs are increasingly popular for addressing broader contexts of health risk beyond a focus on individual factors. Such interventions have the potential to affect multiple social levels of risk and change, including at the individual, network, and community levels, and reflect social ecological principles of interaction across social levels over time. The iterative and feedback dynamic generated by this multi-level effect increases the likelihood for sustained health improvement initiated by those trained to deliver the peer intervention. The Risk Avoidance Partnership (RAP), conducted with heroin and cocaine/crack users in Hartford, Connecticut, exemplified this intervention design and illustrated the multi-level effect on drug users' risk and harm reduction at the individual level, the social network level, and the larger community level. Implications of the RAP program for designing effective prevention programs and for analyzing long-term change to reduce HIV transmission among high-risk groups are discussed from this ecological and multi-level intervention perspective. PMID:19326208

  3. An inverter/controller subsystem optimized for photovoltaic applications

    NASA Technical Reports Server (NTRS)

    Pickrell, R. L.; Osullivan, G.; Merrill, W. C.

    1978-01-01

    Conversion of solar array dc power to ac power stimulated the specification, design, and simulation testing of an inverter/controller subsystem tailored to the photovoltaic power source characteristics. Optimization of the inverter/controller design is discussed as part of an overall photovoltaic power system designed for maximum energy extraction from the solar array. The special design requirements for the inverter/ controller include: a power system controller (PSC) to control continuously the solar array operating point at the maximum power level based on variable solar insolation and cell temperatures; and an inverter designed for high efficiency at rated load and low losses at light loadings to conserve energy.

  4. Program Predicts Nonlinear Inverter Performance

    NASA Technical Reports Server (NTRS)

    Al-Ayoubi, R. R.; Oepomo, T. S.

    1985-01-01

    Program developed for ac power distribution system on Shuttle orbiter predicts total load on inverters and node voltages at each of line replaceable units (LRU's). Mathematical model simulates inverter performance at each change of state in power distribution system.

  5. Invert emulsion well servicing fluids

    SciTech Connect

    Carnicom, W.M.

    1982-03-13

    An invert emulsion well servicing fluid containing an oleaginous phase, an aqueous phase, an invert emulsifier and an effective amount of a solid, particulate polyolefin having a density of about 0.90 gms/cc or greater.

  6. Energy-Saving Inverter

    NASA Technical Reports Server (NTRS)

    Rippel, W. E.; Edwards, D. B.

    1984-01-01

    Commutation by field-effect transistor allows more efficient operation. High voltage field-effect transistor (FET) controls silicon controlled rectifiers (SCR's). Circuit requires only one capacitor and one inductor in commutation circuit: simpler, more efficient, and more economical than conventional inverters. Adaptable to dc-to-dc converters.

  7. Inverting the Achievement Pyramid

    ERIC Educational Resources Information Center

    White-Hood, Marian; Shindel, Melissa

    2006-01-01

    Attempting to invert the pyramid to improve student achievement and increase all students' chances for success is not a new endeavor. For decades, educators have strategized, formed think tanks, and developed school improvement teams to find better ways to improve the achievement of all students. Currently, the No Child Left Behind Act (NCLB) is

  8. An invertibility paradox

    NASA Astrophysics Data System (ADS)

    Binder, P.-M.; Pedraza, J. M.; Garzn, S.

    1999-12-01

    The chaotic volume-preserving standard map is used to illustrate the invertibility paradox, which is related to the reversibility paradox of the microscopic foundations of thermodynamics. The new paradox, whose resolution relies exclusively on phase-space arguments, gives insight into Boltzmann's original resolution of the reversibility paradox.

  9. Achievable capacity improvement by using multi-level modulation format in trench-assisted multi-core fiber system.

    PubMed

    Chang, J H; Choi, H G; Chung, Y C

    2013-06-17

    We evaluate the impacts of using multi-level modulation formats on the transmission capacity of the multi-core fiber (MCF) having trench-assisted index profile and hexagonal layout. For this evaluation, we utilize the spectral efficiency per unit area, defined as the spatial spectral efficiency (SSE). The results show that the SSE improvement achievable by using the higher-level modulation format can be reduced due to its lower tolerance to the inter-core crosstalk. We also evaluate the effects of using large effective area on the transmission capacity of the trench-assisted MCF. The results show that the use of large effective area can decrease this capacity due to the increased inter-core crosstalk and lengthened cable cutoff wavelength, although it can help increase the transmission distance. Thus, it is necessary to optimize the effective area of MCF by considering both the SSE and transmission distance. However, the results indicate that the effect of using different effective areas on the SSE-distance product is not significant, and it is not useful to increase the effective area of the trench-assisted MCF to be larger than ~110 ?m(2). PMID:23787615

  10. Replantation of multi-level fingertip amputation using the pocket principle (palmar pocket method).

    PubMed

    Arata, J; Ishikawa, K; Soeda, H; Kitayama, T

    2003-07-01

    Two cases of multi-level fingertip amputation are presented. In each case, replantation was achieved in a two-stage procedure, involving reattachment, de-epithelialisation and insertion into a palmar pocket in stage 1, followed by removal from the palmar pocket 16 days later. The cases are described and the technique is discussed. PMID:12890466

  11. Multi-Level Assessment of Scientific Content Knowledge Gains Associated with Socioscientific Issues-Based Instruction

    ERIC Educational Resources Information Center

    Klosterman, Michelle L.; Sadler, Troy D.

    2010-01-01

    This study explored the impact of using a socioscientific issue (SSI) based curriculum on developing science content knowledge. Using a multi-level assessment design, student content knowledge gains were measured before and after implementation of a three-week unit on global warming (a prominent SSI) that explored both the relevant science content…

  12. A Multi-Level Assessment of a Program to Teach Medical Students to Teach

    ERIC Educational Resources Information Center

    Blatt, Benjamin; Greenberg, Larrie

    2007-01-01

    Few longitudinal programs exist to teach senior students (MS4s) to be teachers, nor have there been any reports of comprehensive program evaluation in this area. The primary objectives of this study were to describe our ongoing faculty development effort and to develop a multi-level program evaluation, using Dixon's model. The TALKS (Teaching and

  13. Multi-Level Research on Youth Participation in the Haitian Reconstruction

    ERIC Educational Resources Information Center

    Pluim, Gary W. J.

    2012-01-01

    Research in comparative and international education routinely encounters exceptional research conditions. In this article, the author explores the particular issues he faced in his research on multi-level youth programs of the Haitian reconstruction. Through a vertical analysis of internationally sponsored programs, this study required special

  14. The Development of Multi-Level Audio-Visual Teaching Aids for Earth Science.

    ERIC Educational Resources Information Center

    Pitt, William D.

    The project consisted of making a multi-level teaching film titled "Rocks and Minerals of the Ouachita Mountains," which runs for 25 minutes and is in color. The film was designed to be interesting to earth science students from junior high to college, and consists of dialogue combined with motion pictures of charts, sequential diagrams, outcrops,

  15. Multi-Level Assessment of Scientific Content Knowledge Gains Associated with Socioscientific Issues-Based Instruction

    ERIC Educational Resources Information Center

    Klosterman, Michelle L.; Sadler, Troy D.

    2010-01-01

    This study explored the impact of using a socioscientific issue (SSI) based curriculum on developing science content knowledge. Using a multi-level assessment design, student content knowledge gains were measured before and after implementation of a three-week unit on global warming (a prominent SSI) that explored both the relevant science content

  16. A Brief Multi-Dimensional Children's Level-of-Functioning Tool.

    ERIC Educational Resources Information Center

    Srebnik, Debra

    This paper discusses the results of a study that investigated the validity and reliability of the Ecology Rating Scale (ERS). The ERS is a brief, multi-dimensional level-of-functioning instrument that can be rated by parents or clinicians. The ERS is comprised of seven domains of youth functioning: family, school, emotional, legal/justice,

  17. Multi-Level Research on Youth Participation in the Haitian Reconstruction

    ERIC Educational Resources Information Center

    Pluim, Gary W. J.

    2012-01-01

    Research in comparative and international education routinely encounters exceptional research conditions. In this article, the author explores the particular issues he faced in his research on multi-level youth programs of the Haitian reconstruction. Through a vertical analysis of internationally sponsored programs, this study required special…

  18. GROUND WATER MONITORING AND SAMPLING: MULTI-LEVEL VERSUS TRADITIONAL METHODS WHATS WHAT?

    EPA Science Inventory

    After years of research and many publications, the question still remains: What is the best method to collect representative ground water samples from monitoring wells? Numerous systems and devices are currently available for obtaining both multi-level samples as well as traditi...

  19. Multi-Level Partnerships Support a Comprehensive Faith-Based Health Promotion Program

    ERIC Educational Resources Information Center

    Hardison-Moody, Annie; Dunn, Carolyn; Hall, David; Jones, Lorelei; Newkirk, Jimmy; Thomas, Cathy

    2011-01-01

    This article examines the role of multi-level partnerships in implementing Faithful Families Eating Smart and Moving More, a faith-based health promotion program that works with low-resource faith communities in North Carolina. This program incorporates a nine-lesson individual behavior change program in concert with policy and environmental

  20. An adaptive multi-level simulation algorithm for stochastic biological systems

    SciTech Connect

    Lester, C. Giles, M. B.; Baker, R. E.; Yates, C. A.

    2015-01-14

    Discrete-state, continuous-time Markov models are widely used in the modeling of biochemical reaction networks. Their complexity often precludes analytic solution, and we rely on stochastic simulation algorithms (SSA) to estimate system statistics. The Gillespie algorithm is exact, but computationally costly as it simulates every single reaction. As such, approximate stochastic simulation algorithms such as the tau-leap algorithm are often used. Potentially computationally more efficient, the system statistics generated suffer from significant bias unless tau is relatively small, in which case the computational time can be comparable to that of the Gillespie algorithm. The multi-level method [Anderson and Higham, “Multi-level Monte Carlo for continuous time Markov chains, with applications in biochemical kinetics,” SIAM Multiscale Model. Simul. 10(1), 146–179 (2012)] tackles this problem. A base estimator is computed using many (cheap) sample paths at low accuracy. The bias inherent in this estimator is then reduced using a number of corrections. Each correction term is estimated using a collection of paired sample paths where one path of each pair is generated at a higher accuracy compared to the other (and so more expensive). By sharing random variables between these paired paths, the variance of each correction estimator can be reduced. This renders the multi-level method very efficient as only a relatively small number of paired paths are required to calculate each correction term. In the original multi-level method, each sample path is simulated using the tau-leap algorithm with a fixed value of τ. This approach can result in poor performance when the reaction activity of a system changes substantially over the timescale of interest. By introducing a novel adaptive time-stepping approach where τ is chosen according to the stochastic behaviour of each sample path, we extend the applicability of the multi-level method to such cases. We demonstrate the efficiency of our method using a number of examples.

  1. A multi-phase level set framework for source reconstruction in bioluminescence tomography

    SciTech Connect

    Huang Heyu; Qu Xiaochao; Liang Jimin; He Xiaowei; Chen Xueli; Yang Da'an; Tian Jie

    2010-07-01

    We propose a novel multi-phase level set algorithm for solving the inverse problem of bioluminescence tomography. The distribution of unknown interior source is considered as piecewise constant and represented by using multiple level set functions. The localization of interior bioluminescence source is implemented by tracing the evolution of level set function. An alternate search scheme is incorporated to ensure the global optimal of reconstruction. Both numerical and physical experiments are performed to evaluate the developed level set reconstruction method. Reconstruction results show that the proposed method can stably resolve the interior source of bioluminescence tomography.

  2. Laser printing of conformal and multi-level 3D interconnects

    NASA Astrophysics Data System (ADS)

    Kim, H.; Duocastella, M.; Charipar, K. M.; Auyeung, R. C. Y.; Piqu, A.

    2013-10-01

    A crucial challenge in three-dimensional multi-chip assemblies is to establish electrical connections between discrete devices. Here, we apply laser printing of congruent voxels of silver nanopaste for the fabrication of conformal and 3D multi-level interconnects. By controlling laser fluence, various 3D electrodes including freestanding tabs and side contacts over vertical walls can be directly printed without the need for sacrificial layers, chemical etching or electroplating. The electrical characteristics of the printed interconnects are similar to those currently in use by the semiconductor industry. These results are a promising step forward in the generation of customized interconnects for 3D microelectronics.

  3. Integral inverter/battery charger for use in electric vehicles

    NASA Technical Reports Server (NTRS)

    Thimmesch, D.

    1983-01-01

    The design and test results of a thyristor based inverter/charger are discussed. A battery charger is included integral to the inverter by using a subset of the inverter power circuit components. The resulting charger provides electrical isolation between the vehicle propulsion battery and ac line and is capable of charging a 25 kWh propulsion battery in 8 hours from a 220 volt ac line. The integral charger employs the inverter commutation components at a resonant ac/dc isolated converter rated at 3.6 kW. Charger efficiency and power factor at an output power of 3.6 kW are 86% and 95% respectively. The inverter, when operated with a matching polyphase ac induction motor and nominal 132 volt propulsion battery, can provide a peak shaft power of 34 kW (45 ph) during motoring operation and 45 kW (60 hp) during regeneration. Thyristors are employed for the inverter power switching devices and are arranged in an input-commutated topology. This configuration requires only two thyristors to commutate the six main inverter thyristors. Inverter efficiency during motoring operation at motor shaft speeds above 450 rad/sec (4300 rpm) is 92-94% for output power levels above 11 KW (15 hp). The combined ac inverter/charger package weighs 47 kg (103 lbs).

  4. Multi-Level Induction of Categories: Venomous Snakes Hijack the Learning of Lower Levels

    PubMed Central

    Noh, Sharon M.; Yan, Veronica X.; Vendetti, Michael S.; Castel, Alan D.; Bjork, Robert A.

    2014-01-01

    The induction of categories and concepts from exampleswhich plays an important role in how we come to organize and understand the worldcan happen at multiple levels, but how does competing values of these different levels affect their learning? Using perceptually rich images of snakes that could be categorized by their specific genus or a broader category, and that varied in value (whether the snake was venomous vs. whether it was tropical), we asked participants to attend to one level but tested induction at both levels. We found an interaction between study instruction and intrinsic value: Participants in the low-value condition were better able to induce the instructed level, whereas participants in the high-value condition, were significantly better at learning the broad category (i.e., venomness), regardless of instruction. Our results suggest that intrinsically valuable features can affect learning by disrupting the intentional learning of other, task-relevant information, but enhancing the incidental learning of these same features. PMID:24966070

  5. Inverter ratio failure detector

    NASA Technical Reports Server (NTRS)

    Wagner, A. P.; Ebersole, T. J.; Andrews, R. E. (inventors)

    1974-01-01

    A failure detector which detects the failure of a dc to ac inverter is disclosed. The inverter under failureless conditions is characterized by a known linear relationship of its input and output voltages and by a known linear relationship of its input and output currents. The detector includes circuitry which is responsive to the detector's input and output voltages and which provides a failure-indicating signal only when the monitored output voltage is less by a selected factor, than the expected output voltage for the monitored input voltage, based on the known voltages' relationship. Similarly, the detector includes circuitry which is responsive to the input and output currents and provides a failure-indicating signal only when the input current exceeds by a selected factor the expected input current for the monitored output current based on the known currents' relationship.

  6. Inverted organic photosensitive device

    SciTech Connect

    Forrest, Stephen R.; Tong, Xiaoran; Lee, Jun Yeob; Cho, Yong Joo

    2015-09-08

    There is disclosed a method for preparing the surface of a metal substrate. The present disclosure also relates to an organic photovoltaic device including a metal substrate made by such method. Also disclosed herein is an inverted photosensitive device including a stainless steel foil reflective electrode, an organic donor-acceptor heterojunction over the reflective electrode, and a transparent electrode over the donor-acceptor heterojunction.

  7. Interestingness measures and strategies for mining multi-ontology multi-level association rules from gene ontology annotations for the discovery of new GO relationships.

    PubMed

    Manda, Prashanti; McCarthy, Fiona; Bridges, Susan M

    2013-10-01

    The Gene Ontology (GO), a set of three sub-ontologies, is one of the most popular bio-ontologies used for describing gene product characteristics. GO annotation data containing terms from multiple sub-ontologies and at different levels in the ontologies is an important source of implicit relationships between terms from the three sub-ontologies. Data mining techniques such as association rule mining that are tailored to mine from multiple ontologies at multiple levels of abstraction are required for effective knowledge discovery from GO annotation data. We present a data mining approach, Multi-ontology data mining at All Levels (MOAL) that uses the structure and relationships of the GO to mine multi-ontology multi-level association rules. We introduce two interestingness measures: Multi-ontology Support (MOSupport) and Multi-ontology Confidence (MOConfidence) customized to evaluate multi-ontology multi-level association rules. We also describe a variety of post-processing strategies for pruning uninteresting rules. We use publicly available GO annotation data to demonstrate our methods with respect to two applications (1) the discovery of co-annotation suggestions and (2) the discovery of new cross-ontology relationships. PMID:23850840

  8. Macro-level gender equality and alcohol consumption: a multi-level analysis across U.S. States.

    PubMed

    Roberts, Sarah C M

    2012-07-01

    Higher levels of women's alcohol consumption have long been attributed to increases in gender equality. However, only limited research examines the relationship between gender equality and alcohol consumption. This study examined associations between five measures of state-level gender equality and five alcohol consumption measures in the United States. Survey data regarding men's and women's alcohol consumption from the 2005 Behavioral Risk Factor Surveillance System were linked to state-level indicators of gender equality. Gender equality indicators included state-level women's socioeconomic status, gender equality in socioeconomic status, reproductive rights, policies relating to violence against women, and women's political participation. Alcohol consumption measures included past 30-day drinker status, drinking frequency, binge drinking, volume, and risky drinking. Other than drinker status, consumption is measured for drinkers only. Multi-level linear and logistic regression models adjusted for individual demographics as well as state-level income inequality, median income, and % Evangelical Protestant/Mormon. All gender equality indicators were positively associated with both women's and men's drinker status in models adjusting only for individual-level covariates; associations were not significant in models adjusting for other state-level characteristics. All other associations between gender equality and alcohol consumption were either negative or non-significant for both women and men in models adjusting for other state-level factors. Findings do not support the hypothesis that higher levels of gender equality are associated with higher levels of alcohol consumption by women or by men. In fact, most significant findings suggest that higher levels of equality are associated with less alcohol consumption overall. PMID:22521679

  9. Barriers to Uptake of Conservation Agriculture in southern Africa: Multi-level Analyses from Malawi

    NASA Astrophysics Data System (ADS)

    Dougill, Andrew; Stringer, Lindsay; Whitfield, Stephen; Wood, Ben; Chinseu, Edna

    2015-04-01

    Conservation agriculture is a key set of actions within the growing body of climate-smart agriculture activities being advocated and rolled out across much of the developing world. Conservation agriculture has purported benefits for environmental quality, food security and the sustained delivery of ecosystem services. In this paper, new multi-level analyses are presented, assessing the current barriers to adoption of conservation agriculture practices in Malawi. Despite significant donor initiatives that have targeted conservation agriculture projects, uptake rates remain low. This paper synthesises studies from across 3 levels in Malawi: i.) national level- drawing on policy analysis, interviews and a multi-stakeholder workshop; ii.) district level - via assessments of development plans and District Office and extension service support, and; iii) local level - through data gained during community / household level studies in Dedza District that have gained significant donor support for conservation agriculture as a component of climate smart agriculture initiatives. The national level multi-stakeholder Conservation Agriculture workshop identified three areas requiring collaborative research and outlined routes for the empowerment of the National Conservation Agriculture Task Force to advance uptake of conservation agriculture and deliver associated benefits in terms of agricultural development, climate adaptation and mitigation. District level analyses highlight that whilst District Development Plans are now checked against climate change adaptation and mitigation criteria, capacity and knowledge limitations exist at the District level, preventing project interventions from being successfully up-scaled. Community level assessments highlight the need for increased community participation at the project-design phase and identify a pressing requirement for conservation agriculture planning processes (in particular those driven by investments in climate-smart agriculture) to better accommodate, and respond to, the differentiated needs of marginalised groups (e.g. poor, elderly, carers). We identify good practices that can be used to design, plan and implement conservation agriculture projects such that the multiple benefits can be realised. We further outline changes to multi-level policy and institutional arrangements to facilitate greater adoption of conservation agriculture in Malawi, noting the vital importance of District-level institutions and amendments and capacity building required within agricultural extension services. We highlight the need for capacity building and support to ensure conservation agriculture's multiple benefits are realised more widely as a route towards sustainable land management.

  10. A graph-based algorithm for mining multi-level patterns in genomic data.

    PubMed

    Lam, Winnie W M; Chan, Keith C C; Chiu, David K Y; Wong, Andrew K C

    2010-10-01

    Comparative genomics is concerned with the study of genome structure and function of different species. It can provide useful information for the derivation of evolutionary and functional relationships between genomes. Previous work on genome comparison focuses mainly on comparing the entire genomes for visualization without further analysis. As many interesting patterns may exist between genomes and may lead to the discovering of functional gene segments (groups of genes), we propose an algorithm called Multi-Level Genome Comparison Algorithm (MGC) that can be used to facilitate the analysis of genomes at multi-levels during the comparison process to discover sequential and regional consistency in gene segments. Different genomes may have common sub-sequences that differ from each other due to mutations, lateral gene transfers, gene rearrangements, etc., and these sub-sequences are usually not easily identified. Not all the genes can have a perfect one-to-one matching with each other. It is quite possible for one-to-many or many-to-many ambiguous relationships to exist between them. To perform the tasks effectively, MGC takes such ambiguity into consideration during genome comparison by representing genomes in a graph and then make use of a graph mining algorithm called the Multi-Level Attributed Graph Mining Algorithm (MAGMA) to build a hierarchical multi-level graph structure to facilitate genome comparison. To determine the effectiveness of these proposed algorithms, experiments were performed using intra- and inter-species of Microbial genomes. The results show that the proposed algorithms are able to discover multiple level matching patterns that show the similarities and dissimilarities among different genomes, in addition to confirming the specific role of the genes in the genomes. PMID:20981888

  11. Multi-level ground glass nodule detection and segmentation in CT lung images.

    PubMed

    Tao, Yimo; Lu, Le; Dewan, Maneesh; Chen, Albert Y; Corso, Jason; Xuan, Jianhua; Salganicoff, Marcos; Krishnan, Arun

    2009-01-01

    Early detection of Ground Glass Nodule (GGN) in lung Computed Tomography (CT) images is important for lung cancer prognosis. Due to its indistinct boundaries, manual detection and segmentation of GGN is labor-intensive and problematic. In this paper, we propose a novel multi-level learning-based framework for automatic detection and segmentation of GGN in lung CT images. Our main contributions are: firstly, a multi-level statistical learning-based approach that seamlessly integrates segmentation and detection to improve the overall accuracy for GGN detection (in a subvolume). The classification is done at two levels, both voxel-level and object-level. The algorithm starts with a three-phase voxel-level classification step, using volumetric features computed per voxel to generate a GGN class-conditional probability map. GGN candidates are then extracted from this probability map by integrating prior knowledge of shape and location, and the GGN object-level classifier is used to determine the occurrence of the GGN. Secondly, an extensive set of volumetric features are used to capture the GGN appearance. Finally, to our best knowledge, the GGN dataset used for experiments is an order of magnitude larger than previous work. The effectiveness of our method is demonstrated on a dataset of 1100 subvolumes (100 containing GGNs) extracted from about 200 subjects. PMID:20426175

  12. Rapid prototyping of multi-level polydimethylsiloxane-based microfluidic devices

    NASA Astrophysics Data System (ADS)

    Cheong, Wai Chye; Kuan, Yoke Kong; Li, Mo-Huang; Ying, Jackie Y.

    2008-12-01

    There has been considerable progress in the development of micro-fabricated systems for the field of chemical and biological sciences. Much development has been driven by the need of miniaturized systems that allow cost-effective and rapid processing of samples at the point of need. In this work, we investigate the application practicality of Objet Eden500VTMPolyjet as a rapid and economical tool for multi-level microfluidic device rapid prototyping. The Polyjet is a commercial system that utilizes ink-jet technology to print 3-dimensional structures with photopolymer materials. The reproducing capability of the Polyjet system in term of lateral and vertical resolutions, aspect ratio and smoothness of fabricated structures are investigated. In addition, the capability of the Polyjet is demonstrated by fabricating three different devices including: 1) multi-level microfluidic chip for two-step gene synthesis, 2) a fluidic component for micro/macro fluidic interfacing, and 3) PDMS-based microlens.

  13. Research of Real-time Data Warehouse Storage Strategy Based on Multi-level Caches

    NASA Astrophysics Data System (ADS)

    YiChuan, Shao; Yao, Xingjia

    Real-time data warehouse extend the application of traditional data warehouse. It can not only support tactical queries for enterprise but also provide much variable tactical decision support effectively. For these reasons, it is very meaningful to research on the structure of real-time data warehouses. This paper introduced the background of real-time data warehouse and proposed the strategy of real-time data warehouse which is based on double mirror replication mechanism. The strategy is composed of double steps. First we used double mirror replication mechanism to enable continuous loading data in the real-time data warehouse with minimum impact in query execution time. Second we proposed incorporating multi-level caches into the data warehouse structure which is based on real-time partition and gave the process of design and implementation with details. We differentiated between queries with various data freshness requirements, and used multi-level caches to satisfy these different requirements.

  14. Multi-level conduction in NiO resistive memory device prepared by solution route

    NASA Astrophysics Data System (ADS)

    Kannan, V.; Senthilkumar, V.; Rhee, J. K.

    2013-03-01

    In this paper, we present nickel oxide (NiO) thin film bipolar non-volatile resistive memory device with multi-level conduction prepared by solution route at room temperature. The fabricated device with structure Al/NiO/ITO exhibits excellent switching parameters, such as a stable resistance value in both ON and OFF states for over 10 000 s (retention) and 105 switching cycles of memory operation (endurance). Stable multi-level conductance states are observed in the memory device, which could be exploited for a multilevel-cell programming scheme. The switching mechanism in the resistive memory device is discussed based on the formation/dissolution of conductive filaments.

  15. Multi-level structure in the large scale distribution of optically luminous galaxies

    NASA Astrophysics Data System (ADS)

    Deng, Xin-fa; Deng, Zu-gan; Liu, Yong-zhen

    1992-04-01

    Fractal dimensions in the large scale distribution of galaxies have been calculated with the method given by Wen et al. [1] Samples are taken from CfA redshift survey in northern and southern galactic [2] hemisphere in our analysis respectively. Results from these two regions are compared with each other. There are significant differences between the distributions in these two regions. However, our analyses do show some common features of the distributions in these two regions. All subsamples show multi-level fractal character distinctly. Combining it with the results from analyses of samples given by IRAS galaxies and results from samples given by redshift survey in pencil-beam fields, [3,4] we suggest that multi-level fractal structure is most likely to be a general and important character in the large scale distribution of galaxies. The possible implications of this character are discussed.

  16. [Study on multi-level fractal features extraction method of breast mass].

    PubMed

    Ke, Li; Zhang, Xue; Kang, Yan

    2013-04-01

    Breast mass is women's common disease, and it seriously affects the health of women. Accurate detection and location of the mass will greatly improve the precision of the diagnosis of the breast disease. Studies have shown that the organizational structure and surface roughness of the mass constitute the texture features of mass and it is an important basis for distinguishing the mass. In this paper, a multi-level fractal features extraction method is proposed, and, moreover, the fractal feature vector of the suspicious lesions has been established, thus realizing the feature extraction and analysis of the mammary gland. Finally, the result of classification with the support vector machine (SVM) was given. 110 mammograms are extracted and classified with an accuracy of 90%. The results showed that the multi-level fractal features extraction and classification methods proposed in this paper could improve the accuracy of mass detection and could be effective for the early diagnosis of the disease. PMID:23858747

  17. An adaptive, multi-level method for elliptic boundary value problems

    NASA Technical Reports Server (NTRS)

    Bank, R. E.; Sherman, A. H.

    1981-01-01

    Subroutine PLTMG is a FORTRAN program for solving self-adjoint elliptic boundary value problems in general regions of R-squared. It is based on a piecewise linear triangle finite element method, an adaptive grid refinement procedure, and a multi-level iterative method to solve the resulting sets of linear equations. This paper describes the method and presents some numerical results and comparisons.

  18. Serving the army as secretaries: intersectionality, multi-level contract and subjective experience of citizenship.

    PubMed

    Lomsky-Feder, Edna; Sasson-Levy, Orna

    2015-03-01

    With the growing elusiveness of the state apparatus in late modernity, military service is one of the last institutions to be clearly identified with the state, its ideologies and its policies. Therefore, negotiations between the military and its recruits produce acting subjects of citizenship with long-lasting consequences. Arguing that these negotiations are regulated by multi-level (civic, group, and individual) contracts, we explore the various meanings that these contracts obtain at the intersectionality of gender, class, and ethnicity; and examine how they shape the subjective experience of soldierhood and citizenship. More particularly, we analyse the meaning of military service in the retrospective life stories of Israeli Jewish women from various ethno-class backgrounds who served as army secretaries - a low-status, feminine gender-typed occupation within a hyper-masculine organization. Findings reveal that for women of the lower class, the organizing cultural schema of the multi-level contract is that of achieving respectability through military service, which means being included in the national collective. Conversely, for middle-class women, it is the sense of entitlement that shapes their contract with the military, which they expect to signify and maintain their privileged status. Thus, while for the lower class, the multi-level contract is about inclusion within the boundaries of the national collective, for the dominant groups, this contract is about reproducing social class hierarchies within national boundaries. PMID:25469654

  19. Multi-level Bayesian safety analysis with unprocessed Automatic Vehicle Identification data for an urban expressway.

    PubMed

    Shi, Qi; Abdel-Aty, Mohamed; Yu, Rongjie

    2016-03-01

    In traffic safety studies, crash frequency modeling of total crashes is the cornerstone before proceeding to more detailed safety evaluation. The relationship between crash occurrence and factors such as traffic flow and roadway geometric characteristics has been extensively explored for a better understanding of crash mechanisms. In this study, a multi-level Bayesian framework has been developed in an effort to identify the crash contributing factors on an urban expressway in the Central Florida area. Two types of traffic data from the Automatic Vehicle Identification system, which are the processed data capped at speed limit and the unprocessed data retaining the original speed were incorporated in the analysis along with road geometric information. The model framework was proposed to account for the hierarchical data structure and the heterogeneity among the traffic and roadway geometric data. Multi-level and random parameters models were constructed and compared with the Negative Binomial model under the Bayesian inference framework. Results showed that the unprocessed traffic data was superior. Both multi-level models and random parameters models outperformed the Negative Binomial model and the models with random parameters achieved the best model fitting. The contributing factors identified imply that on the urban expressway lower speed and higher speed variation could significantly increase the crash likelihood. Other geometric factors were significant including auxiliary lanes and horizontal curvature. PMID:26722989

  20. Integrated all-photonic non-volatile multi-level memory

    NASA Astrophysics Data System (ADS)

    Ríos, Carlos; Stegmaier, Matthias; Hosseini, Peiman; Wang, Di; Scherer, Torsten; Wright, C. David; Bhaskaran, Harish; Pernice, Wolfram H. P.

    2015-11-01

    Implementing on-chip non-volatile photonic memories has been a long-term, yet elusive goal. Photonic data storage would dramatically improve performance in existing computing architectures by reducing the latencies associated with electrical memories and potentially eliminating optoelectronic conversions. Furthermore, multi-level photonic memories with random access would allow for leveraging even greater computational capability. However, photonic memories have thus far been volatile. Here, we demonstrate a robust, non-volatile, all-photonic memory based on phase-change materials. By using optical near-field effects, we realize bit storage of up to eight levels in a single device that readily switches between intermediate states. Our on-chip memory cells feature single-shot readout and switching energies as low as 13.4 pJ at speeds approaching 1 GHz. We show that individual memory elements can be addressed using a wavelength multiplexing scheme. Our multi-level, multi-bit devices provide a pathway towards eliminating the von Neumann bottleneck and portend a new paradigm in all-photonic memory and non-conventional computing.

  1. Multi-level multi-criteria analysis of alternative fuels for waste collection vehicles in the United States.

    PubMed

    Maimoun, Mousa; Madani, Kaveh; Reinhart, Debra

    2016-04-15

    Historically, the U.S. waste collection fleet was dominated by diesel-fueled waste collection vehicles (WCVs); the growing need for sustainable waste collection has urged decision makers to incorporate economically efficient alternative fuels, while mitigating environmental impacts. The pros and cons of alternative fuels complicate the decisions making process, calling for a comprehensive study that assesses the multiple factors involved. Multi-criteria decision analysis (MCDA) methods allow decision makers to select the best alternatives with respect to selection criteria. In this study, two MCDA methods, Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) and Simple Additive Weighting (SAW), were used to rank fuel alternatives for the U.S. waste collection industry with respect to a multi-level environmental and financial decision matrix. The environmental criteria consisted of life-cycle emissions, tail-pipe emissions, water footprint (WFP), and power density, while the financial criteria comprised of vehicle cost, fuel price, fuel price stability, and fueling station availability. The overall analysis showed that conventional diesel is still the best option, followed by hydraulic-hybrid WCVs, landfill gas (LFG) sourced natural gas, fossil natural gas, and biodiesel. The elimination of the WFP and power density criteria from the environmental criteria ranked biodiesel 100 (BD100) as an environmentally better alternative compared to other fossil fuels (diesel and natural gas). This result showed that considering the WFP and power density as environmental criteria can make a difference in the decision process. The elimination of the fueling station and fuel price stability criteria from the decision matrix ranked fossil natural gas second after LFG-sourced natural gas. This scenario was found to represent the status quo of the waste collection industry. A sensitivity analysis for the status quo scenario showed the overall ranking of diesel and fossil natural gas to be more sensitive to changing fuel prices as compared to other alternatives. PMID:26824270

  2. Multi-level model of missed nursing care in the context of hospital merger.

    PubMed

    Castner, Jessica; Wu, Yow-Wu B; Dean-Baar, Susan

    2015-04-01

    The aim of this study was to delineate the multi-level relationships of individual registered nurse (RN) and nursing unit factors on missed nursing care. This was a quantitative model-building study using a descriptive, cross-sectional design. Surveys (N = 553) and administrative unit records from nurses in one hospital system undergoing merger were included. The results showed that 36% of the variation in missed nursing care is due to the unit context, with a corresponding 64% due to individual nurse differences. At the unit level, workload, skill mix, and critical unit type affected the amount of missed nursing care. At the individual nurse level, more experience, supplies problems, communication problems, and involvement in errors of commission all increased the perception of the amount of missed nursing care. Education level was not related to the amount of missed nursing care. The findings highlight the importance of unit- and individual-level interventions to redesign hospital nursing care. PMID:24869493

  3. Developing the evidence-base for Safe Communities: a multi-level, partly randomised, controlled trial.

    PubMed

    Seedat, M; McClure, R; Suffla, S; van Niekerk, A

    2012-01-01

    Safe Communities, representing a global activation of the public health logic, may be strengthened through theoretical, methodological and empirical support. In the spirit of this Special Issue that aims to analyse the achievements and challenges inherent to Safe Communities, we offer our contribution in the form of a methodology of a multi-country child safety, peace and health promotion study. The study, situated within an African-centred initiative called Ukuphepha - an isiZulu word meaning demonstrating African safety - is underpinned by four theoretical claims that frame injury and violence prevention as a multi-disciplinary issue to be addressed through a suite of interventions to family and extended social systems. The interventions, sensitive to the priorities of each participating country, have been informed by the literature on effective interventions and the authors' joint experiences of community development. The study is designed as a population-based, multi-level, multi-intervention partly randomised controlled trial, and there are potentially 24 participant communities representing South Africa, Mozambique, Egypt, Zambia, Uganda, Bangladesh, Malaysia and Australia - over three commencement phases. Whereas process evaluation will focus on community engagement, impact evaluation will consider risk and protective factors, and outcome evaluation will examine the overall effectiveness of the interventions. Notwithstanding the many challenges, the study will provide insights into the methodology and mechanisms of ecologically-oriented interventions that locate injury and violence prevention as an activity arising from safety, peace and health promotion. PMID:22873717

  4. Multi-Level Determinants of Parasitic Fly Infection in Forest Passerines

    PubMed Central

    Manzoli, Daro Ezequiel; Antoniazzi, Leandro Ral; Saravia, Mara Jos; Silvestri, Leonardo; Rorhmann, David; Beldomenico, Pablo Martn

    2013-01-01

    The study of myiasis is important because they may cause problems to the livestock industry, public health, or wildlife conservation. The ecology of parasitic dipterans that cause myiasis is singular, as they actively seek their hosts over relatively long distances. However, studies that address the determinants of myiasis dynamics are very scarce. The genus Philornis include species that may be excellent models to study myiasis ecology, as they exclusively parasitize bird nestlings, which stay in their nests until they are fully fledged, and larvae remain at the point of entry until the parasitic stage is over, thus allowing the collection of sequential individual-level infection data from virtually all the hosts present at a particular area. Here we offer a stratified multi-level analysis of longitudinal data of Philornis torquans parasitism in replicated forest bird communities of central Argentina. Using Generalized Linear Models and Generalized Linear Mixed Models and an information theory approach for model selection, we conducted four groups of analyses, each with a different study unit, the individual, the brood, the community at a given week, and the community at a given year. The response variable was larval abundance per nestling or mean abundance per nestling. At each level, models included the variables of interest of that particular level, and also potential confounders and effect modifiers of higher levels. We found associations of large magnitude at all levels, but only few variables truly governed the dynamics of this parasite. At the individual level, the infection was determined by the species and the age of the host. The main driver of parasite abundance at the microhabitat level was the average height of the forest, and at the community level, the density of hosts and prior rainfall. This multi-level approach contributed to a better understanding of the ecology of myiasis. PMID:23874408

  5. Inverted glass harp.

    PubMed

    Quinn, Daniel B; Rosenberg, Brian J

    2015-08-01

    We present an analytical treatment of the acoustics of liquid-filled wine glasses, or "glass harps." The solution is generalized such that under certain assumptions it reduces to previous glass harp models, but also leads to a proposed musical instrument, the "inverted glass harp," in which an empty glass is submerged in a liquid-filled basin. The versatility of the solution demonstrates that all glass harps are governed by a family of solutions to Laplace's equation around a vibrating disk. Tonal analyses of recordings for a sample glass are offered as confirmation of the scaling predictions. PMID:26382336

  6. Inverted glass harp

    NASA Astrophysics Data System (ADS)

    Quinn, Daniel B.; Rosenberg, Brian J.

    2015-08-01

    We present an analytical treatment of the acoustics of liquid-filled wine glasses, or "glass harps." The solution is generalized such that under certain assumptions it reduces to previous glass harp models, but also leads to a proposed musical instrument, the "inverted glass harp," in which an empty glass is submerged in a liquid-filled basin. The versatility of the solution demonstrates that all glass harps are governed by a family of solutions to Laplace's equation around a vibrating disk. Tonal analyses of recordings for a sample glass are offered as confirmation of the scaling predictions.

  7. Gas cooled traction drive inverter

    DOEpatents

    Chinthavali, Madhu Sudhan

    2013-10-08

    The present invention provides a modular circuit card configuration for distributing heat among a plurality of circuit cards. Each circuit card includes a housing adapted to dissipate heat in response to gas flow over the housing. In one aspect, a gas-cooled inverter includes a plurality of inverter circuit cards, and a plurality of circuit card housings, each of which encloses one of the plurality of inverter cards.

  8. Rehabilitation of a patient with a rare multi-level isthmic spondylolisthesis: a case report

    PubMed Central

    Wong, Leong C

    2004-01-01

    A rare multilevel isthmic spondylolisthesis was discovered in a young male patient following an acute onset of low back pain. The prevalence of spondylolisthesis in the adult population is low and it is believed that the prevalence of multiple level spondylolisthesis is even rarer. A combination of onset of ambulation, hereditary factors, and sports involving hyper-extension of the spine are predisposing factors. Conservative treatment such as chiropractic manipulation and rehabilitation of the spine are first treatment options before surgical intervention is considered. The clinical presentations, radiographic features, treatment options including rehabilitation methods are discussed. PMID:17549226

  9. A Multi-Level Approach to Outreach for Geologic Sequestration Projects

    USGS Publications Warehouse

    Greenberg, S.E.; Leetaru, H.E.; Krapac, I.G.; Hnottavange-Telleen, K.; Finley, R.J.

    2009-01-01

    Public perception of carbon capture and sequestration (CCS) projects represents a potential barrier to commercialization. Outreach to stakeholders at the local, regional, and national level is needed to create familiarity with and potential acceptance of CCS projects. This paper highlights the Midwest Geological Sequestration Consortium (MGSC) multi-level outreach approach which interacts with multiple stakeholders. The MGSC approach focuses on external and internal communication. External communication has resulted in building regional public understanding of CCS. Internal communication, through a project Risk Assessment process, has resulted in enhanced team communication and preparation of team members for outreach roles. ?? 2009 Elsevier Ltd. All rights reserved.

  10. Multi-level discriminative dictionary learning with application to large scale image classification.

    PubMed

    Shen, Li; Sun, Gang; Huang, Qingming; Wang, Shuhui; Lin, Zhouchen; Wu, Enhua

    2015-10-01

    The sparse coding technique has shown flexibility and capability in image representation and analysis. It is a powerful tool in many visual applications. Some recent work has shown that incorporating the properties of task (such as discrimination for classification task) into dictionary learning is effective for improving the accuracy. However, the traditional supervised dictionary learning methods suffer from high computation complexity when dealing with large number of categories, making them less satisfactory in large scale applications. In this paper, we propose a novel multi-level discriminative dictionary learning method and apply it to large scale image classification. Our method takes advantage of hierarchical category correlation to encode multi-level discriminative information. Each internal node of the category hierarchy is associated with a discriminative dictionary and a classification model. The dictionaries at different layers are learnt to capture the information of different scales. Moreover, each node at lower layers also inherits the dictionary of its parent, so that the categories at lower layers can be described with multi-scale information. The learning of dictionaries and associated classification models is jointly conducted by minimizing an overall tree loss. The experimental results on challenging data sets demonstrate that our approach achieves excellent accuracy and competitive computation cost compared with other sparse coding methods for large scale image classification. PMID:26080049

  11. Eating disorders and multi-level models of emotion: an integrated model.

    PubMed

    Fox, John R E; Power, Michael J

    2009-01-01

    This paper examines the relationship between emotions, depression and eating disorders. Initially, a review is undertaken of the current state of the research and clinical literature with regard to emotional factors in eating disorders. This literature is then integrated within a version of the multi-level model of emotion proposed by Power and Dalgleish. The aim of this paper is to incorporate a basic emotions, multi-modal perspective into developing a new emotions-based model that offers a theoretical understanding of psychological mechanisms in eating disorders. Within the new Schematic Propositional Analogical Associative Representation System model applied to eating disorders, it is argued that the emotions of anger and disgust are of importance in eating disorders and that the eating disorder itself operates as an inhibitor of emotions within the self. It is hoped that the development of a multi-levelled model of eating disorders will allow for the construction of number of specific testable hypotheses that are relevant to future research into the psychological treatment and understanding of eating disorders. PMID:19639647

  12. Inverted Channels of Aeolis

    NASA Technical Reports Server (NTRS)

    2004-01-01

    17 November 2004 Mars was once a much wetter world than it is today. Locked within the martian bedrock are ancient channels and valleys through which liquids -- e.g., water -- once flowed. In the Aeolis region of Mars, wind erosion has exposed and inverted a plethora of ancient channels - stream beds -- in a fan-shaped sedimentary rock unit near 6.3oS, 208.6oW. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an example. The smooth-looking, sinuous ridges that run left-right across the image are the inverted channels. The rugged, sharp-looking ridges that run nearly north-south (up-down) through the image are yardangs--ridges formed by wind erosion. The water (or other liquid) responsible for the original channels flowed from the left (west) to right/upper right (east/northeast). This scene covers an area approximately 3 km (1.9 mi) across, and is illuminated by sunlight from the upper left.

  13. Multi-valley effective mass theory for device-level modeling of open quantum dynamics

    NASA Astrophysics Data System (ADS)

    Jacobson, N. Tobias; Baczewski, Andrew D.; Frees, Adam; Gamble, John King; Montano, Ines; Moussa, Jonathan E.; Muller, Richard P.; Nielsen, Erik

    2015-03-01

    Simple models for semiconductor-based quantum information processors can provide useful qualitative descriptions of device behavior. However, as experimental implementations have matured, more specific guidance from theory has become necessary, particularly in the form of quantitatively reliable yet computationally efficient modeling. Besides modeling static device properties, improved characterization of noisy gate operations requires a more sophisticated description of device dynamics. Making use of recent developments in multi-valley effective mass theory, we discuss device-level simulations of the open system quantum dynamics of a qubit interacting with phonons and other noise sources. Sandia is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy National Nuclear Security Administration under Contract No. DE-AC04-94AL85000.

  14. Parallel of low-level computer vision algorithms on a multi-DSP system

    NASA Astrophysics Data System (ADS)

    Liu, Huaida; Jia, Pingui; Li, Lijian; Yang, Yiping

    2011-06-01

    Parallel hardware becomes a commonly used approach to satisfy the intensive computation demands of computer vision systems. A multiprocessor architecture based on hypercube interconnecting digital signal processors (DSPs) is described to exploit the temporal and spatial parallelism. This paper presents a parallel implementation of low level vision algorithms designed on multi-DSP system. The convolution operation has been parallelized by using redundant boundary partitioning. Performance of the parallel convolution operation is investigated by varying the image size, mask size and the number of processors. Experimental results show that the speedup is close to the ideal value. However, it can be found that the loading imbalance of processor can significantly affect the computation time and speedup of the multi- DSP system.

  15. Low-power multi-chip module and board-level links for data transfer

    SciTech Connect

    Carson, R.F.; Hardin, T.L.; Warren, M.E.; Lear, K.L.; Lovejoy, M.L.; Seigal, P.K.; Craft, D.C.; Enquist, P.J.

    1997-03-01

    Advanced device technologies such as Vertical Cavity Surface-Emitting Lasers (VCSELs) and diffractive micro lenses can be obtained with novel packaging techniques to allow low-power interconnection of parallel optical signals. These interconnections can be realized directly on circuit boards, in a multi-chip module format, or in packages that emulate electrical connectors. For applications such as stacking of Multi-Chip Module (MCM) layers, the links may be realized in bi-directional form using integrated diffractive microlenses. In the stacked MCM design, consumed electrical power is minimized by use of a relatively high laser output from high efficiency VCSELs, and a receiver design that is optimized for low power, at the expense of dynamic range. Within certain constraints, the design may be extended to other forms such as board-level interconnects.

  16. Using probabilistic methods to define reliability requirements for high power inverters

    NASA Astrophysics Data System (ADS)

    Morris, Russell W.; Fife, John M.

    2009-08-01

    The solar energy industry has reached the point where utilities are employing large multi-megawatt photovoltaic projects to provide power to the utility grid in a variety of configurations. The ability to deliver or connect solar energy to a commercial power grid with high efficiency and over a broad spectrum of environments is critical to the success of the solar utility industry. These analyses aid in evaluating the potential profitability of a project and aid in optimizing a power plant design by understanding the real life attributes of the components and subsystems. This paper presents a methodology for modeling system-level power production as a function of time based on concurrent reliability simulation of individual subsystems such as power inverters. Each subsystem model is also time-dependent and depends on understanding the probabilistic nature of the actual failure rates of the components and on endurance testing or field data for the subsystems. As an example of a detailed time-dependent predictive reliability model, the power inverter is used. The power inverter reliability and availability is essential for continuing improvement of solar power plant efficiency and cost effectiveness over the life of the installation. The authors discuss some of the common failure probability distributions, their application to components and how these affect such areas as the maintenance intervals and the number of expected spares needed. This affects the Levelized Cost of Energy (LCOE) of the system and the potential for profitable operation.

  17. Performance Enhancement of Embedded System Based Multilevel Inverter Using Genetic Algorithm

    NASA Astrophysics Data System (ADS)

    Perumal, Maruthu Pandi; Nanjudapan, Devarajan

    2011-07-01

    This paper presents an optimal solution for eliminating pre specified order of harmonics from a stepped waveform of a multilevel inverter topology with equal dc sources. The main challenge of solving the associated non linear equation which are transcendental in nature and therefore have multiple solutions is the convergence of the relevant algorithms and therefore an initial point selected considerably close to the exact solution is required. The paper describes an efficient genetic algorithm that reduces significantly the computational burden resulting in fast convergence. An objective function describing a measure of effectiveness of eliminating selected order of harmonics while controlling the fundamental component is derived. The performance of cascaded multilevel inverter is compared based on computation of switching angle using Genetic Algorithm as well as conventional Newton Raphson approach. A significant improvement in harmonic profile is achieved in the GA based approach. A nine level cascaded multi level inverter is simulated in MATLAB Simulink and a proto type model has been fabricated to validate the simulation results.

  18. Dynamic performance and control of a static var generator using cascade multilevel inverters

    SciTech Connect

    Peng, Fang Zheng; Lai, Jih-Sheng

    1996-10-01

    A cascade multilevel inverter is proposed for static VAR shifting, compensation/generation applications. The new cascade M-level inverter consists of (M-1)/2 single-phase full bridges in which each bridge has its own separate dc source. This inverter can generate almost sinusoidal waveform voltage with only one time switching per cycle. It can eliminate the need for transformers in multipulse inverters. A prototype static VAR generator (SVG) system using 11- level cascade inverter (21-level line-to-line voltage waveform) has been built. The output voltage waveform is equivalent to that of a 60- pulse inverter. This paper focuses on dynamic performance of the cascade inverter based SVG system. Control schemes are proposed to achieve a fast response which is impossible for a conventional static VAR compensator (SVC). Analytical, simulated and experimental results show the superiority of the proposed SVG system.

  19. Agent-based model with multi-level herding for complex financial systems.

    PubMed

    Chen, Jun-Jie; Tan, Lei; Zheng, Bo

    2015-01-01

    In complex financial systems, the sector structure and volatility clustering are respectively important features of the spatial and temporal correlations. However, the microscopic generation mechanism of the sector structure is not yet understood. Especially, how to produce these two features in one model remains challenging. We introduce a novel interaction mechanism, i.e., the multi-level herding, in constructing an agent-based model to investigate the sector structure combined with volatility clustering. According to the previous market performance, agents trade in groups, and their herding behavior comprises the herding at stock, sector and market levels. Further, we propose methods to determine the key model parameters from historical market data, rather than from statistical fitting of the results. From the simulation, we obtain the sector structure and volatility clustering, as well as the eigenvalue distribution of the cross-correlation matrix, for the New York and Hong Kong stock exchanges. These properties are in agreement with the empirical ones. Our results quantitatively reveal that the multi-level herding is the microscopic generation mechanism of the sector structure, and provide new insight into the spatio-temporal interactions in financial systems at the microscopic level. PMID:25669427

  20. Modified FGP approach and MATLAB program for solving multi-level linear fractional programming problems

    NASA Astrophysics Data System (ADS)

    Lachhwani, Kailash; Nehra, Suresh

    2014-09-01

    In this paper, we present modified fuzzy goal programming (FGP) approach and generalized MATLAB program for solving multi-level linear fractional programming problems (ML-LFPPs) based on with some major modifications in earlier FGP algorithms. In proposed modified FGP approach, solution preferences by the decision makers at each level are not considered and fuzzy goal for the decision vectors is defined using individual best solutions. The proposed modified algorithm as well as MATLAB program simplifies the earlier algorithm on ML-LFPP by eliminating solution preferences by the decision makers at each level, thereby avoiding difficulties associate with multi-level programming problems and decision deadlock situation. The proposed modified technique is simple, efficient and requires less computational efforts in comparison of earlier FGP techniques. Also, the proposed coding of generalized MATLAB program based on this modified approach for solving ML-LFPPs is the unique programming tool toward dealing with such complex mathematical problems with MATLAB. This software based program is useful and user can directly obtain compromise optimal solution of ML-LFPPs with it. The aim of this paper is to present modified FGP technique and generalized MATLAB program to obtain compromise optimal solution of ML-LFP problems in simple and efficient manner. A comparative analysis is also carried out with numerical example in order to show efficiency of proposed modified approach and to demonstrate functionality of MATLAB program.

  1. Agent-based model with multi-level herding for complex financial systems

    NASA Astrophysics Data System (ADS)

    Chen, Jun-Jie; Tan, Lei; Zheng, Bo

    2015-02-01

    In complex financial systems, the sector structure and volatility clustering are respectively important features of the spatial and temporal correlations. However, the microscopic generation mechanism of the sector structure is not yet understood. Especially, how to produce these two features in one model remains challenging. We introduce a novel interaction mechanism, i.e., the multi-level herding, in constructing an agent-based model to investigate the sector structure combined with volatility clustering. According to the previous market performance, agents trade in groups, and their herding behavior comprises the herding at stock, sector and market levels. Further, we propose methods to determine the key model parameters from historical market data, rather than from statistical fitting of the results. From the simulation, we obtain the sector structure and volatility clustering, as well as the eigenvalue distribution of the cross-correlation matrix, for the New York and Hong Kong stock exchanges. These properties are in agreement with the empirical ones. Our results quantitatively reveal that the multi-level herding is the microscopic generation mechanism of the sector structure, and provide new insight into the spatio-temporal interactions in financial systems at the microscopic level.

  2. Agent-based model with multi-level herding for complex financial systems

    PubMed Central

    Chen, Jun-Jie; Tan, Lei; Zheng, Bo

    2015-01-01

    In complex financial systems, the sector structure and volatility clustering are respectively important features of the spatial and temporal correlations. However, the microscopic generation mechanism of the sector structure is not yet understood. Especially, how to produce these two features in one model remains challenging. We introduce a novel interaction mechanism, i.e., the multi-level herding, in constructing an agent-based model to investigate the sector structure combined with volatility clustering. According to the previous market performance, agents trade in groups, and their herding behavior comprises the herding at stock, sector and market levels. Further, we propose methods to determine the key model parameters from historical market data, rather than from statistical fitting of the results. From the simulation, we obtain the sector structure and volatility clustering, as well as the eigenvalue distribution of the cross-correlation matrix, for the New York and Hong Kong stock exchanges. These properties are in agreement with the empirical ones. Our results quantitatively reveal that the multi-level herding is the microscopic generation mechanism of the sector structure, and provide new insight into the spatio-temporal interactions in financial systems at the microscopic level. PMID:25669427

  3. Modified FGP approach and MATLAB program for solving multi-level linear fractional programming problems

    NASA Astrophysics Data System (ADS)

    Lachhwani, Kailash; Nehra, Suresh

    2015-09-01

    In this paper, we present modified fuzzy goal programming (FGP) approach and generalized MATLAB program for solving multi-level linear fractional programming problems (ML-LFPPs) based on with some major modifications in earlier FGP algorithms. In proposed modified FGP approach, solution preferences by the decision makers at each level are not considered and fuzzy goal for the decision vectors is defined using individual best solutions. The proposed modified algorithm as well as MATLAB program simplifies the earlier algorithm on ML-LFPP by eliminating solution preferences by the decision makers at each level, thereby avoiding difficulties associate with multi-level programming problems and decision deadlock situation. The proposed modified technique is simple, efficient and requires less computational efforts in comparison of earlier FGP techniques. Also, the proposed coding of generalized MATLAB program based on this modified approach for solving ML-LFPPs is the unique programming tool toward dealing with such complex mathematical problems with MATLAB. This software based program is useful and user can directly obtain compromise optimal solution of ML-LFPPs with it. The aim of this paper is to present modified FGP technique and generalized MATLAB program to obtain compromise optimal solution of ML-LFP problems in simple and efficient manner. A comparative analysis is also carried out with numerical example in order to show efficiency of proposed modified approach and to demonstrate functionality of MATLAB program.

  4. Fusion of multi-sensory NDT data for reliable detection of surface cracks: Signal-level vs. decision-level

    NASA Astrophysics Data System (ADS)

    Heideklang, René; Shokouhi, Parisa

    2016-02-01

    We present and compare two different approaches for NDT multi-sensor data fusion at signal (low) and decision (high) levels. Signal-level fusion is achieved by applying simple algebraic rules to strategically post-processed images. This is done in the original domain or in the domain of a suitable signal transform. The importance of signal normalization for low-level fusion applications is emphasized in regard to heterogeneous NDT data sets. For fusion at decision level, we develop a procedure based on assembling joint kernel density estimation (KDE). The procedure involves calculating KDEs for individual sensor detections and aggregating them by applying certain combination rules. The underlying idea is that if the detections from more than one sensor fall spatially close to one another, they are likely to result from the presence of a defect. On the other hand, single-senor detections are more likely to be structural noise or false alarm indications. To this end, we design the KDE combination rules such that it prevents single-sensor domination and allows data-driven scaling to account for the influence of individual sensors. We apply both fusion rules to a three-sensor dataset consisting in ET, MFL/GMR and TT data collected on a specimen with built-in surface discontinuities. The performance of the fusion rules in defect detection is quantitatively evaluated and compared against those of the individual sensors. Both classes of data fusion rules result in a fused image of fewer false alarms and thus improved defect detection. Finally, we discuss the advantages and disadvantages of low-level and high-level NDT data fusion with reference to our experimental results.

  5. In Good Company? A Multi-Study, Multi-Level Investigation of the Effects of Coworker Relationships on Employee Well-Being

    ERIC Educational Resources Information Center

    Simon, Lauren S.; Judge, Timothy A.; Halvorsen-Ganepola, Marie D. K.

    2010-01-01

    Two multi-level studies were conducted to examine the effects of attitudes towards coworkers on daily well-being. Study 1 linked daily levels of coworker satisfaction to job satisfaction and life satisfaction and examined the extent to which job satisfaction mediated the relationship between coworker satisfaction and life satisfaction among 33…

  6. In Good Company? A Multi-Study, Multi-Level Investigation of the Effects of Coworker Relationships on Employee Well-Being

    ERIC Educational Resources Information Center

    Simon, Lauren S.; Judge, Timothy A.; Halvorsen-Ganepola, Marie D. K.

    2010-01-01

    Two multi-level studies were conducted to examine the effects of attitudes towards coworkers on daily well-being. Study 1 linked daily levels of coworker satisfaction to job satisfaction and life satisfaction and examined the extent to which job satisfaction mediated the relationship between coworker satisfaction and life satisfaction among 33

  7. Improved multi-level proteinprotein interaction prediction with semantic-based regularization

    PubMed Central

    2014-01-01

    Background Proteinprotein interactions can be seen as a hierarchical process occurring at three related levels: proteins bind by means of specific domains, which in turn form interfaces through patches of residues. Detailed knowledge about which domains and residues are involved in a given interaction has extensive applications to biology, including better understanding of the binding process and more efficient drug/enzyme design. Alas, most current interaction prediction methods do not identify which parts of a protein actually instantiate an interaction. Furthermore, they also fail to leverage the hierarchical nature of the problem, ignoring otherwise useful information available at the lower levels; when they do, they do not generate predictions that are guaranteed to be consistent between levels. Results Inspired by earlier ideas of Yip et al. (BMC Bioinformatics 10:241, 2009), in the present paper we view the problem as a multi-level learning task, with one task per level (proteins, domains and residues), and propose a machine learning method that collectively infers the binding state of all object pairs. Our method is based on Semantic Based Regularization (SBR), a flexible and theoretically sound machine learning framework that uses First Order Logic constraints to tie the learning tasks together. We introduce a set of biologically motivated rules that enforce consistent predictions between the hierarchy levels. Conclusions We study the empirical performance of our method using a standard validation procedure, and compare its performance against the only other existing multi-level prediction technique. We present results showing that our method substantially outperforms the competitor in several experimental settings, indicating that exploiting the hierarchical nature of the problem can lead to better predictions. In addition, our method is also guaranteed to produce interactions that are consistent with respect to the proteindomainresidue hierarchy. PMID:24725682

  8. Implications of multi-scale sea level and climate variability for coastal resources

    USGS Publications Warehouse

    Karamperidou, Christina; Engel, Victor; Lall, Upmanu; Stabenau, Erik; Smith, Thomas J., III

    2013-01-01

    While secular changes in regional sea levels and their implications for coastal zone management have been studied extensively, less attention is being paid to natural fluctuations in sea levels, whose interaction with a higher mean level could have significant impacts on low-lying areas, such as wetlands. Here, the long record of sea level at Key West, FL is studied in terms of both the secular trend and the multi-scale sea level variations. This analysis is then used to explore implications for the Everglades National Park (ENP), which is recognized internationally for its ecological significance, and is the site of the largest wetland restoration project in the world. Very shallow topographic gradients (36 cm per km) make the region susceptible to small changes in sea level. Observations of surface water levels from a monitoring network within ENP exhibit both the long-term trends and the interannual-to-(multi)decadal variability that are observed in the Key West record. Water levels recorded at four long-term monitoring stations within ENP exhibit increasing trends approximately equal to or larger than the long-term trend at Key West. Time- and frequency-domain analyses highlight the potential influence of climate mechanisms, such as the El Nio/Southern Oscillation and the North Atlantic Oscillation (NAO), on Key West sea levels and marsh water levels, and the potential modulation of their influence by the background state of the North Atlantic Sea Surface Temperatures. In particular, the Key West sea levels are found to be positively correlated with the NAO index, while the two series exhibit high spectral power during the transition to a cold Atlantic Multidecadal Oscillation (AMO). The correlation between the Key West sea levels and the NINO3 Index reverses its sign in coincidence with a reversal of the AMO phase. Water levels in ENP are also influenced by precipitation and freshwater releases from the northern boundary of the Park. The analysis of both climate variability and climate change in such wetlands is needed to inform management practices in coastal wetland zones around the world.

  9. Inverted Metamorphic Cell Development: Cooperative Research and Development Final Report, CRADA Number CRD-05-156

    SciTech Connect

    Wanlass, M.

    2012-05-01

    This CRADA targeted technology transfer of the inverted metamorphic multi-junction (IMM) solar cell innovation from NREL to Emcore Photovoltaics. The technology transfer was successfully completed. Additionally, NREL provided materials characterization of solar cell structures produced at Emcore.

  10. Inverting an Introductory Statistics Classroom

    ERIC Educational Resources Information Center

    Kraut, Gertrud L.

    2015-01-01

    The inverted classroom allows more in-class time for inquiry-based learning and for working through more advanced problem-solving activities than does the traditional lecture class. The skills acquired in this learning environment offer benefits far beyond the statistics classroom. This paper discusses four ways that can make the inverted

  11. Building obesity in Canada: understanding the individual- and neighbourhood-level determinants using a multi-level approach.

    PubMed

    Pouliou, Theodora; Elliott, Susan J; Paez, Antonio; Newbold, K Bruce

    2014-11-01

    The objective of this paper was to identify heterogeneities associated with the relationships between the body mass index (BMI) and individual as well as socio-environmental correlates at the individual- and area-levels. The data sources used were: (i) the 2003 Canadian Community Health Survey; (ii) the 2001 Canadian Census; and (iii) the Enhanced Points of Interest (EPOI) database from the Desktop Mapping Technologies Inc. Participants were adults (? 20 years; n = 12,836; based on a survey weight scheme N(weighted) = 5,418,218) from Toronto and Vancouver census metropolitan areas with no missing BMI records. In addition to conventional 1 km-buffers, we constructed activity-space-buffers to better assess the walkability and potentially increased BMI of individuals. Multi-level analysis was then applied to estimate the relative effects of both individual- and area-level risk-factors for increased BMI. The findings demonstrate a negative association between BMI and energy expenditure, mixed land uses, residential density and average value of dwellings, while a positive association was found with low educational attainment. Relationships were independent of individual characteristics such as age and ethnicity. Although the majority of the variation in these outcomes was found to be due to individual-level differences, this study did show significant differences at the area-level as well. The activity-space-buffers presented a vast improvement compared to the conventional 1 km-buffers. The results presented support the rationale that targeting high-risk individuals will only address a portion of the increasing BMI problem; it is essential to also address the characteristics of places that compel individuals to make unhealthy choices. PMID:25545925

  12. [Narrow band multi-region level set method for remote sensing image].

    PubMed

    Fang, Jiang-Xiong; Tu, En-Mei; Yang, Jie; Jia, Zhen-Hong; Nikola, Kasabov

    2011-11-01

    Massive redundant contours happen when the classical Chan-Vese (C-V) model is used to segment remote sensing images, which have interlaced edges. What's more, this model can't segment homogeneous objects with multiple regions. In order to overcome this limitation of C-V model, narrow band multiple level set method is proposed. The use of N-1 curves is required for the segmentation of N regions and each curve represents one region. First, the level set model to establish an independent multi-region region can eliminate the redundant contours and avoids the problems of vacuum and overlap. Then, narrow band approach to level set method can reduce the computational cost. Experimental results of remote image verify that our model is efficient and accurate. PMID:22242504

  13. Identification of rickettsial isolates at the species level using multi-spacer typing

    PubMed Central

    Fournier, Pierre-Edouard; Raoult, Didier

    2007-01-01

    Background In order to estimate whether multi-spacer typing (MST), based on the sequencing of variable intergenic spacers, could serve for the identification of Rickettsia at the species level, we applied it to 108 rickettsial isolates or arthropod amplicons that include representatives of 23 valid Rickettsia species. Results MST combining the dksA-xerC, mppA-purC, and rpmE-tRNAfMet spacer sequences identified 61 genotypes, allowing the differentiation of each species by at least one distinct genotype. In addition, MST was discriminatory at the strain level in six species for which several isolates or arthropod amplicons were available. Conclusion MST proved to be a reproducible and high-resolution genotyping method allowing clear identification of rickettsial isolates at the species level and further additional differentiation of strains within some species. PMID:17662158

  14. Multi-objective optimization of tire carcass contours using a systematic aspiration-level adjustment procedure

    NASA Astrophysics Data System (ADS)

    Cho, J. R.; Jeong, H. S.; Yoo, W. S.

    While forming a basic tire configuration and supporting most static and dynamic loads of automobiles, tire carcass influences major tire performances according to its contour. Among significant tire performances, we in this study intend to improve the automobile maneuverability and the tire durability by optimizing the sidewall carcass contour. In order to effectively maximize these multi-objectives, we refine the conventional satisficing trade-off methods (STOM) which were proposed originally for the multi-objective structural optimization, by introducing a systematic aspiration-level adjustment procedure. According to the systematic procedure, we perform the sidewall contour optimization that ideally distributes the sidewall carcass tension and minimizes strain-energy density at the belt edge. Since the tire analysis is highly nonlinear problem we employ an incremental analysis scheme, together with the finite-difference sensitivity scheme. Through the numerical experiment, we confirmed that the refined multi-objective optimization technique systematically leads to a final optimum sidewall contour, together with the stable and rapid convergence.

  15. Automatic detection of multi-level acetowhite regions in RGB color images of the uterine cervix

    NASA Astrophysics Data System (ADS)

    Lange, Holger

    2005-04-01

    Uterine cervical cancer is the second most common cancer among women worldwide. Colposcopy is a diagnostic method used to detect cancer precursors and cancer of the uterine cervix, whereby a physician (colposcopist) visually inspects the metaplastic epithelium on the cervix for certain distinctly abnormal morphologic features. A contrast agent, a 3-5% acetic acid solution, is used, causing abnormal and metaplastic epithelia to turn white. The colposcopist considers diagnostic features such as the acetowhite, blood vessel structure, and lesion margin to derive a clinical diagnosis. STI Medical Systems is developing a Computer-Aided-Diagnosis (CAD) system for colposcopy -- ColpoCAD, a complex image analysis system that at its core assesses the same visual features as used by colposcopists. The acetowhite feature has been identified as one of the most important individual predictors of lesion severity. Here, we present the details and preliminary results of a multi-level acetowhite region detection algorithm for RGB color images of the cervix, including the detection of the anatomic features: cervix, os and columnar region, which are used for the acetowhite region detection. The RGB images are assumed to be glare free, either obtained by cross-polarized image acquisition or glare removal pre-processing. The basic approach of the algorithm is to extract a feature image from the RGB image that provides a good acetowhite to cervix background ratio, to segment the feature image using novel pixel grouping and multi-stage region-growing algorithms that provide region segmentations with different levels of detail, to extract the acetowhite regions from the region segmentations using a novel region selection algorithm, and then finally to extract the multi-levels from the acetowhite regions using multiple thresholds. The performance of the algorithm is demonstrated using human subject data.

  16. Push pull microfluidics on a multi-level 3D CD.

    PubMed

    Thio, Tzer Hwai Gilbert; Ibrahim, Fatimah; Al-Faqheri, Wisam; Moebius, Jacob; Khalid, Noor Sakinah; Soin, Norhayati; Kahar, Maria Kahar Bador Abdul; Madou, Marc

    2013-08-21

    A technique known as thermo-pneumatic (TP) pumping is used to pump fluids on a microfluidic compact disc (CD) back towards the CD center against the centrifugal force that pushes liquids from the center to the perimeter of the disc. Trapped air expands in a TP air chamber during heating, and this creates positive pressure on liquids located in chambers connected to that chamber. While the TP air chamber and connecting channels are easy to fabricate in a one-level CD manufacturing technique, this approach provides only one way pumping between two chambers, is real-estate hungry and leads to unnecessary heating of liquids in close proximity to the TP chamber. In this paper, we present a novel TP push and pull pumping method which allows for pumping of liquid in any direction between two connected liquid chambers. To ensure that implementation of TP push and pull pumping also addresses the issue of space and heating challenges, a multi-level 3D CD design is developed, and localized forced convection heating, rather than infra-red (IR) is applied. On a multi-level 3D CD, the TP features are placed on a top level separate from the rest of the microfluidic processes that are implemented on a lower separate level. This approach allows for heat shielding of the microfluidic process level, and efficient usage of space on the CD for centrifugal handling of liquids. The use of localized forced convection heating, rather than infra-red (IR) or laser heating in earlier implementations allows not only for TP pumping of liquids while the CD is spinning but also makes heat insulation for TP pumping and other fluidic functions easier. To aid in future implementations of TP push and pull pumping on a multi-level 3D CD, study on CD surface heating is also presented. In this contribution, we also demonstrate an advanced application of pull pumping through the implementation of valve-less switch pumping. PMID:23774994

  17. Push pull microfluidics on a multi-level 3D CD

    PubMed Central

    Thio, Tzer Hwai Gilbert; Ibrahim, Fatimah; Al-Faqheri, Wisam; Moebius, Jacob; Khalid, Noor Sakinah; Soin, Norhayati; Kahar, Maria Kahar Bador Abdul; Madou, Marc

    2013-01-01

    A technique known as thermo-pneumatic (TP) pumping is used to pump fluids on a microfluidic compact disc (CD) back towards the CD center against the centrifugal force that pushes liquids from the center to the perimeter of the disc. Trapped air expands in a TP air chamber during heating, and this creates positive pressure on liquids located in chambers connected to that chamber. While the TP air chamber and connecting channels are easy to fabricate in a one-level CD manufacturing technique, this approach provides only one way pumping between two chambers, is real-estate hungry and leads to unnecessary heating of liquids in close proximity to the TP chamber. In this paper, we present a novel TP push and pull pumping method which allows for pumping of liquid in any direction between two connected liquid chambers. To ensure that implementation of TP push and pull pumping also addresses the issue of space and heating challenges, a multi-level 3D CD design is developed, and localized forced convection heating, rather than infra-red (IR) is applied. On a multi-level 3D CD, the TP features are placed on a top level separate from the rest of the microfluidic processes that are implemented on a lower separate level. This approach allows for heat shielding of the microfluidic process levels, and efficient usage of space on the CD for centrifugal handling of liquids. The use of localized forced convection heating, rather than infra-red (IR) or laser heating in earlier implementations allows not only for TP pumping of liquids while the CD is spinning but also makes heat insulation for TP pumping and other fluidic functions easier. To aid in future implementations of TP push and pull pumping on a multi-level 3D CD, study on CD surface heating is also presented. In this contribution, we also demonstrate an advanced application of pull pumping through the implementation of valve-less switch pumping. PMID:23774994

  18. An Intrusion Detection System Based on Multi-Level Clustering for Hierarchical Wireless Sensor Networks

    PubMed Central

    Butun, Ismail; Ra, In-Ho; Sankar, Ravi

    2015-01-01

    In this work, an intrusion detection system (IDS) framework based on multi-level clustering for hierarchical wireless sensor networks is proposed. The framework employs two types of intrusion detection approaches: (1) downward-IDS (D-IDS) to detect the abnormal behavior (intrusion) of the subordinate (member) nodes; and (2) upward-IDS (U-IDS) to detect the abnormal behavior of the cluster heads. By using analytical calculations, the optimum parameters for the D-IDS (number of maximum hops) and U-IDS (monitoring group size) of the framework are evaluated and presented. PMID:26593915

  19. An Intrusion Detection System Based on Multi-Level Clustering for Hierarchical Wireless Sensor Networks.

    PubMed

    Butun, Ismail; Ra, In-Ho; Sankar, Ravi

    2015-01-01

    In this work, an intrusion detection system (IDS) framework based on multi-level clustering for hierarchical wireless sensor networks is proposed. The framework employs two types of intrusion detection approaches: (1) "downward-IDS (D-IDS)" to detect the abnormal behavior (intrusion) of the subordinate (member) nodes; and (2) "upward-IDS (U-IDS)" to detect the abnormal behavior of the cluster heads. By using analytical calculations, the optimum parameters for the D-IDS (number of maximum hops) and U-IDS (monitoring group size) of the framework are evaluated and presented. PMID:26593915

  20. Characterization and simulation of the response of Multi-Pixel Photon Counters to low light levels

    NASA Astrophysics Data System (ADS)

    Vacheret, A.; Barker, G. J.; Dziewiecki, M.; Guzowski, P.; Haigh, M. D.; Hartfiel, B.; Izmaylov, A.; Johnston, W.; Khabibullin, M.; Khotjantsev, A.; Kudenko, Yu.; Kurjata, R.; Kutter, T.; Lindner, T.; Masliah, P.; Marzec, J.; Mineev, O.; Musienko, Yu.; Oser, S.; Retire, F.; Salih, R. O.; Shaikhiev, A.; Thompson, L. F.; Ward, M. A.; Wilson, R. J.; Yershov, N.; Zaremba, K.; Ziembicki, M.

    2011-11-01

    The calorimeter, range detector and active target elements of the T2K near detectors rely on the Hamamatsu Photonics Multi-Pixel Photon Counters (MPPCs) to detect scintillation light produced by charged particles. Detailed measurements of the MPPC gain, afterpulsing, crosstalk, dark noise, and photon detection efficiency for low light levels are reported. In order to account for the impact of the MPPC behavior on T2K physics observables, a simulation program has been developed based on these measurements. The simulation is used to predict the energy resolution of the detector.

  1. Application of a multi-level grid method to transonic flow calculations

    NASA Technical Reports Server (NTRS)

    South, J. C., Jr.; Brandt, A.

    1976-01-01

    A multi-level grid method was studied as a possible means of accelerating convergence in relaxation calculations for transonic flows. The method employs a hierarchy of grids, ranging from very coarse to fine. The coarser grids are used to diminish the magnitude of the smooth part of the residuals. The method was applied to the solution of the transonic small disturbance equation for the velocity potential in conservation form. Nonlifting transonic flow past a parabolic arc airfoil is studied with meshes of both constant and variable step size.

  2. Level set algorithms comparison for multi-slice CT left ventricle segmentation

    NASA Astrophysics Data System (ADS)

    Medina, Ruben; La Cruz, Alexandra; Ordoñes, Andrés.; Pesántez, Daniel; Morocho, Villie; Vanegas, Pablo

    2015-12-01

    The comparison of several Level Set algorithms is performed with respect to 2D left ventricle segmentation in Multi-Slice CT images. Five algorithms are compared by calculating the Dice coefficient between the resulting segmentation contour and a reference contour traced by a cardiologist. The algorithms are also tested on images contaminated with Gaussian noise for several values of PSNR. Additionally an algorithm for providing the initialization shape is proposed. This algorithm is based on a combination of mathematical morphology tools with watershed and region growing algorithms. Results on the set of test images are promising and suggest the extension to 3{D MSCT database segmentation.

  3. A multi-level code for metallurgical effects in metal-forming processes

    SciTech Connect

    Taylor, P.A.; Silling, S.A.; Hughes, D.A.; Bammann, D.J.; Chiesa, M.L.

    1997-08-01

    The authors present the final report on a Laboratory-Directed Research and Development (LDRD) project, A Multi-level Code for Metallurgical Effects in metal-Forming Processes, performed during the fiscal years 1995 and 1996. The project focused on the development of new modeling capabilities for simulating forging and extrusion processes that typically display phenomenology occurring on two different length scales. In support of model fitting and code validation, ring compression and extrusion experiments were performed on 304L stainless steel, a material of interest in DOE nuclear weapons applications.

  4. Magnetically-controllable optical multi-stability in magneto-optic fiber Bragg gratings with potential applications to multi-level all-optical regeneration

    NASA Astrophysics Data System (ADS)

    Wan, Qing-Yao; Wu, Bao-Jian; Zhou, Xing-Yu; Wen, Feng

    2015-08-01

    Starting with the nonlinear coupled-mode equations of guided optical waves in the magneto-optic fiber Bragg grating (MFBG), the amplitude transfer curve of the transmitted light is numerically calculated for the incident right-circularly polarized wave, and the multi-stability is analyzed by introducing the parameter of jitter suppression. It is shown that, (i) the performance of amplitude jitter suppression in the stable states of high level is better than that of low level; (ii) the jitter suppression in the multi-stable regions can be enhanced when the magnetic field is applied to the MFBG in the opposite direction of the incident wave; and (iii) by adjusting the applied magnetic field, the multi-stable levels can be tuned flexibly, which is helpful for developing the intelligent all-optical devices for multilevel regeneration.

  5. Intelligent Control of an Inverted Pendulum

    NASA Astrophysics Data System (ADS)

    Rekdalsbakken, Webjorn

    An inverted pendulum represents an unstable system which is excellent for demonstrating the use of feedback control with different kinds of control strategies. In this work state feedback of the inverted pendulum is examined. First a pole placement algorithm is explored. After that artificial intelligence (AI) methods are investigated to better cope with the nonlinearities of the physical model. The technique used is based on a hybrid system combining a neural network (NN) with a genetic algorithm (GA). The NN controller is trained by the GA against the behaviour of the physical model. The results of the training process show that the chromosome population tends to station at a suboptimal level, and that changes in the environmental parameters have to take place to reach a new optimal level. By systematically changing these parameters the NN controller will gradually adapt to the pendulum behaviour.

  6. A study on the impact of high penetration distributed generation inverters on grid operation and stability

    NASA Astrophysics Data System (ADS)

    Gu, Fei; Brouwer, Jack; Samuelsen, Scott

    2013-09-01

    Recent advances in inverter technology have enabled ancillary services such as volt/VAR regulation, SCADA communications, and active power filtering. Smart inverters can not only provide real power, but can be controlled to use excess capacity to provide reactive power compensation, power flow control, and active power filtering without supplementary inverter hardware. A transient level inverter model based on the Solectria 7700 inverter is developed and used to assess these control strategies using field data from an existing branch circuit containing two Amonix 68kW CPV-7700 systems installed at the University of California, Irvine.

  7. Evaluating Multi-Level Models to Test Occupancy State Responses of Plethodontid Salamanders.

    PubMed

    Kroll, Andrew J; Garcia, Tiffany S; Jones, Jay E; Dugger, Katie; Murden, Blake; Johnson, Josh; Peerman, Summer; Brintz, Ben; Rochelle, Michael

    2015-01-01

    Plethodontid salamanders are diverse and widely distributed taxa and play critical roles in ecosystem processes. Due to salamander use of structurally complex habitats, and because only a portion of a population is available for sampling, evaluation of sampling designs and estimators is critical to provide strong inference about Plethodontid ecology and responses to conservation and management activities. We conducted a simulation study to evaluate the effectiveness of multi-scale and hierarchical single-scale occupancy models in the context of a Before-After Control-Impact (BACI) experimental design with multiple levels of sampling. Also, we fit the hierarchical single-scale model to empirical data collected for Oregon slender and Ensatina salamanders across two years on 66 forest stands in the Cascade Range, Oregon, USA. All models were fit within a Bayesian framework. Estimator precision in both models improved with increasing numbers of primary and secondary sampling units, underscoring the potential gains accrued when adding secondary sampling units. Both models showed evidence of estimator bias at low detection probabilities and low sample sizes; this problem was particularly acute for the multi-scale model. Our results suggested that sufficient sample sizes at both the primary and secondary sampling levels could ameliorate this issue. Empirical data indicated Oregon slender salamander occupancy was associated strongly with the amount of coarse woody debris (posterior mean = 0.74; SD = 0.24); Ensatina occupancy was not associated with amount of coarse woody debris (posterior mean = -0.01; SD = 0.29). Our simulation results indicate that either model is suitable for use in an experimental study of Plethodontid salamanders provided that sample sizes are sufficiently large. However, hierarchical single-scale and multi-scale models describe different processes and estimate different parameters. As a result, we recommend careful consideration of study questions and objectives prior to sampling data and fitting models. PMID:26619010

  8. Evaluating Multi-Level Models to Test Occupancy State Responses of Plethodontid Salamanders

    PubMed Central

    Kroll, Andrew J.; Garcia, Tiffany S.; Jones, Jay E.; Dugger, Katie; Murden, Blake; Johnson, Josh; Peerman, Summer; Brintz, Ben; Rochelle, Michael

    2015-01-01

    Plethodontid salamanders are diverse and widely distributed taxa and play critical roles in ecosystem processes. Due to salamander use of structurally complex habitats, and because only a portion of a population is available for sampling, evaluation of sampling designs and estimators is critical to provide strong inference about Plethodontid ecology and responses to conservation and management activities. We conducted a simulation study to evaluate the effectiveness of multi-scale and hierarchical single-scale occupancy models in the context of a Before-After Control-Impact (BACI) experimental design with multiple levels of sampling. Also, we fit the hierarchical single-scale model to empirical data collected for Oregon slender and Ensatina salamanders across two years on 66 forest stands in the Cascade Range, Oregon, USA. All models were fit within a Bayesian framework. Estimator precision in both models improved with increasing numbers of primary and secondary sampling units, underscoring the potential gains accrued when adding secondary sampling units. Both models showed evidence of estimator bias at low detection probabilities and low sample sizes; this problem was particularly acute for the multi-scale model. Our results suggested that sufficient sample sizes at both the primary and secondary sampling levels could ameliorate this issue. Empirical data indicated Oregon slender salamander occupancy was associated strongly with the amount of coarse woody debris (posterior mean = 0.74; SD = 0.24); Ensatina occupancy was not associated with amount of coarse woody debris (posterior mean = -0.01; SD = 0.29). Our simulation results indicate that either model is suitable for use in an experimental study of Plethodontid salamanders provided that sample sizes are sufficiently large. However, hierarchical single-scale and multi-scale models describe different processes and estimate different parameters. As a result, we recommend careful consideration of study questions and objectives prior to sampling data and fitting models. PMID:26619010

  9. Coaxial inverted geometry transistor having buried emitter

    NASA Technical Reports Server (NTRS)

    Hruby, R. J.; Cress, S. B.; Dunn, W. R. (inventors)

    1973-01-01

    The invention relates to an inverted geometry transistor wherein the emitter is buried within the substrate. The transistor can be fabricated as a part of a monolithic integrated circuit and is particularly suited for use in applications where it is desired to employ low actuating voltages. The transistor may employ the same doping levels in the collector and emitter, so these connections can be reversed.

  10. Multi-Level Anomaly Detection on Time-Varying Graph Data

    SciTech Connect

    Bridges, Robert A; Collins, John P; Ferragut, Erik M; Laska, Jason A; Sullivan, Blair D

    2015-01-01

    This work presents a novel modeling and analysis framework for graph sequences which addresses the challenge of detecting and contextualizing anomalies in labelled, streaming graph data. We introduce a generalization of the BTER model of Seshadhri et al. by adding flexibility to community structure, and use this model to perform multi-scale graph anomaly detection. Specifically, probability models describing coarse subgraphs are built by aggregating probabilities at finer levels, and these closely related hierarchical models simultaneously detect deviations from expectation. This technique provides insight into a graph's structure and internal context that may shed light on a detected event. Additionally, this multi-scale analysis facilitates intuitive visualizations by allowing users to narrow focus from an anomalous graph to particular subgraphs or nodes causing the anomaly. For evaluation, two hierarchical anomaly detectors are tested against a baseline Gaussian method on a series of sampled graphs. We demonstrate that our graph statistics-based approach outperforms both a distribution-based detector and the baseline in a labeled setting with community structure, and it accurately detects anomalies in synthetic and real-world datasets at the node, subgraph, and graph levels. To illustrate the accessibility of information made possible via this technique, the anomaly detector and an associated interactive visualization tool are tested on NCAA football data, where teams and conferences that moved within the league are identified with perfect recall, and precision greater than 0.786.

  11. Multi-Level Construction of Polar Codes for Half-Duplex Wireless Coded-Cooperative Networks

    NASA Astrophysics Data System (ADS)

    Ejaz, Saqib; FengFan, Yang; Soliman, Tamer H. M.

    2015-11-01

    In this paper, Plotkin's construction is employed to buildup longer length polar codes with the help of shorter length polar codes. Firstly, we present the multi-level code construction steps for non-cooperative communication schemes. Secondly, we extend the proposed multi-level polar code construction to coded-cooperative scenarios due to the parallel split in the proposed encoding scheme. Since, relay plays a pivotal role in the overall bit error rate (BER) performance of the coded-cooperative schemes, therefore, an efficient criteria of information bit selection at the relay is also presented. Furthermore, we propose a novel joint successive cancellation decoding scheme, which is employed at the destination and provides significant coding gains. Various numerical simulations show that the proposed polar coded-cooperative scheme (PCCS) scheme not only outperforms non-cooperative polar coded scheme but also the existing cooperative schemes for polar codes under identical conditions over an additive white Gaussian noise (AWGN) and quasi-static Rayleigh fading channels.

  12. Analysis of a transformer-less, multi-level DC-DC converter for HVDC operation

    SciTech Connect

    Karady, G.G.; Devarajan, S.

    1998-12-31

    HVDC systems require DC step up and DC step down units. The traditional approach is the application of twelve-pulse thyristor bridges with transformers. The developments of fast switching IGBT devices permit the development of transformer-less, multi-level converters. A multi-level circuit was suggested by Limpaecher. This paper presents a detailed simulation of the proposed circuit together with the analysis of its performance. The converter consists of a set of capacitors, air core inductors and solid state switches arranged in a ladder network. In the step-up mode, the closing of solid state switches resonantly charges the capacitors in parallel through an air-cored inductor. Then solid state switches resonantly charges the capacitors in parallel through an air-cored inductor. Then solid state switches connect the capacitors in series and discharge them through an air-core inductor to the load. In the step-down mode the capacitors are charged in series and discharged in parallel. The circuit has three modes of operation in each cycle: charge, inversion, and discharge. The circuit operation is analyzed in each mode using SPICE simulations. The selection of the components is discussed and output voltage regulation is analyzed. The results show that the proposed circuit promises significant reduction of losses, because of the zero current switching. The investment cost is reduced because of the elimination of transformers.

  13. Bayesian hierarchical models for multi-level repeated ordinal data using WinBUGS.

    PubMed

    Qiu, Zhenguo; Song, Peter X K; Tan, Ming

    2002-05-01

    Multi-level repeated ordinal data arise if ordinal outcomes are measured repeatedly in subclusters of a cluster or on subunits of an experimental unit. If both the regression coefficients and the correlation parameters are of interest, the Bayesian hierarchical models have proved to be a powerful tool for analysis with computation being performed by Markov Chain Monte Carlo (MCMC) methods. The hierarchical models extend the random effects models by including a (usually flat) prior on the regression coefficients and parameters in the distribution of the random effects. Because the MCMC can be implemented by the widely available BUGS or WinBUGS software packages, the computation burden of MCMC has been alleviated. However, thoughtfulness is essential in order to use this software effectively to analyze such data with complex structures. For example, we may have to reparameterize the model and standardize the covariates to accelerate the convergence of the MCMC, and then carefully monitor the convergence of the Markov chain. This article aims at resolving these issues in the application of the WinBUGS through the analysis of a real multi-level ordinal data. In addition, we extend the hierarchical model to include a wider class of distributions for the random effects. We propose to use the deviance information criterion (DIC) for model selection. We show that the WinBUGS software can readily implement such extensions and the DIC criterion. PMID:12413235

  14. Multi-Level Interval Estimation for Locating damage in Structures by Using Artificial Neural Networks

    SciTech Connect

    Pan Danguang; Gao Yanhua; Song Junlei

    2010-05-21

    A new analysis technique, called multi-level interval estimation method, is developed for locating damage in structures. In this method, the artificial neural networks (ANN) analysis method is combined with the statistics theory to estimate the range of damage location. The ANN is multilayer perceptron trained by back-propagation. Natural frequencies and modal shape at a few selected points are used as input to identify the location and severity of damage. Considering the large-scale structures which have lots of elements, multi-level interval estimation method is developed to reduce the estimation range of damage location step-by-step. Every step, estimation range of damage location is obtained from the output of ANN by using the method of interval estimation. The next ANN training cases are selected from the estimation range after linear transform, and the output of new ANN estimation range of damage location will gained a reduced estimation range. Two numerical example analyses on 10-bar truss and 100-bar truss are presented to demonstrate the effectiveness of the proposed method.

  15. Multivariate Cutoff Level Analysis (MultiCoLA) of large community data sets

    PubMed Central

    Gobet, Anglique; Quince, Christopher; Ramette, Alban

    2010-01-01

    High-throughput sequencing techniques are becoming attractive to molecular biologists and ecologists as they provide a time- and cost-effective way to explore diversity patterns in environmental samples at an unprecedented resolution. An issue common to many studies is the definition of what fractions of a data set should be considered as rare or dominant. Yet this question has neither been satisfactorily addressed, nor is the impact of such definition on data set structure and interpretation been fully evaluated. Here we propose a strategy, MultiCoLA (Multivariate Cutoff Level Analysis), to systematically assess the impact of various abundance or rarity cutoff levels on the resulting data set structure and on the consistency of the further ecological interpretation. We applied MultiCoLA to a 454 massively parallel tag sequencing data set of V6 ribosomal sequences from marine microbes in temperate coastal sands. Consistent ecological patterns were maintained after removing up to 3540% rare sequences and similar patterns of beta diversity were observed after denoising the data set by using a preclustering algorithm of 454 flowgrams. This example validates the importance of exploring the impact of the definition of rarity in large community data sets. Future applications can be foreseen for data sets from different types of habitats, e.g. other marine environments, soil and human microbiota. PMID:20547594

  16. Multi-level Simulation of a Real Time Vibration Monitoring System Component

    NASA Technical Reports Server (NTRS)

    Roberston, Bryan; Wilkerson, DeLisa

    2004-01-01

    This paper describes the development of a custom built Digital Signal Processing (DSP) printed circuit board designed to implement the Advanced Real Time Vibration Monitoring Subsystem proposed by MSFC Transportation Directorate in 2000 for the Space Shuttle Main Engine Advanced Health Management System (AHMS). This Real Time Vibration Monitoring System (RTVMS) is being developed for ground use as part of the AHMS Health Management Computer-Integrated Rack Assembly (HMC-IRA). The HMC-IRA RTVMS design contains five DSPs which are highly interconnected through individual communication ports, shared memory, and a unique communication router that allows all the DSPs to receive digitized data from two multi-channel analog boards simultaneously. This paper will briefly cover the overall board design but will focus primarily on the state-of-the-art simulation environment within which this board was developed. This 16-layer board with over 1800 components and an additional mezzanine card has been an extremely challenging design. Utilization of a Mentor Graphics simulation environment provided the unique board and system level simulation capability to ascertain any timing or functional concerns before production. By combining VHDL, Synopsys Software and Hardware Models, and the Mentor Design Capture Environment, multiple simulations were developed to verify the RTVMS design. This multi-level simulation allowed the designers to achieve complete operability without error the first time the RTVMS printed circuit board was powered. The HMCIRA design has completed all engineering unit testing and the deliverable unit is currently under development.

  17. Multi-level Simulation of a Real Time Vibration Monitoring System Component

    NASA Technical Reports Server (NTRS)

    Robertson, Bryan A.; Wilkerson, Delisa

    2005-01-01

    This paper describes the development of a custom built Digital Signal Processing (DSP) printed circuit board designed to implement the Advanced Real Time Vibration Monitoring Subsystem proposed by Marshall Space Flight Center (MSFC) Transportation Directorate in 2000 for the Space Shuttle Main Engine Advanced Health Management System (AHMS). This Real Time Vibration Monitoring System (RTVMS) is being developed for ground use as part of the AHMS Health Management Computer-Integrated Rack Assembly (HMC-IRA). The HMC-IRA RTVMS design contains five DSPs which are highly interconnected through individual communication ports, shared memory, and a unique communication router that allows all the DSPs to receive digitized data fiom two multi-channel analog boards simultaneously. This paper will briefly cover the overall board design but will focus primarily on the state-of-the-art simulation environment within which this board was developed. This 16-layer board with over 1800 components and an additional mezzanine card has been an extremely challenging design. Utilization of a Mentor Graphics simulation environment provided the unique board and system level simulation capability to ascertain any timing or functional concerns before production. By combining VHDL, Synopsys Software and Hardware Models, and the Mentor Design Capture Environment, multiple simulations were developed to verify the RTVMS design. This multi-level simulation allowed the designers to achieve complete operability without error the first time the RTVMS printed circuit board was powered. The HMC-IRA design has completed all engineering and deliverable unit testing. P

  18. Fabricating a multi-level barrier-integrated microfluidic device using grey-scale photolithography

    NASA Astrophysics Data System (ADS)

    Nam, Yoonkwang; Kim, Minseok; Kim, Taesung

    2013-10-01

    Most polymer-replica-based microfluidic devices are mainly fabricated by using standard soft-lithography technology so that multi-level masters (MLMs) require multiple spin-coatings, mask alignments, exposures, developments, and bakings. In this paper, we describe a simple method for fabricating MLMs for planar microfluidic channels with multi-level barriers (MLBs). A single photomask is necessary for standard photolithography technology to create a polydimethylsiloxane grey-scale photomask (PGSP), which adjusts the total amount of UV absorption in a negative-tone photoresist via a wide range of dye concentrations. Since the PGSP in turn adjusts the degree of cross-linking of the photoresist, this method enables the fabrication of MLMs for an MLB-integrated microfluidic device. Since the PGSP-based soft-lithography technology provides a simple but powerful fabrication method for MLBs in a microfluidic device, we believe that the fabrication method can be widely used for micro total analysis systems that benefit from MLBs. We demonstrate an MLB-integrated microfluidic device that can separate microparticles.

  19. Microseismic mapping of hydraulic fractures using multi-level wireline receivers

    SciTech Connect

    Warpinski, N.R.; Engler, B.P.; Young, C.J.; Peterson, R.; Branagan, P.T.; Fix, J.E.

    1995-07-01

    Hydraulic fracture diagnostic experiments are being conducted at the GRI/DOE Multi-Site (M-Site) located in the Piceance basin of Colorado. Tests described in this paper use a multi-level advanced-receiver system to build on previous work that showed the advantages of using a single advanced receiver to monitor microseisms. The current test has a four-level receiver system monitoring four separate fracture experiments conducted over a one week period, and includes a velocity tomographic survey and detailed orientation survey. Hydraulic fractures were monitored from an offset well 210 ft away from the treatment well. The results of these monitoring tests show a fracture developing asymmetrically with time, yielding a fracture-wing asymmetry of 2:1. The fracture initially grows within the pay zone to essentially its total length, and then begins to grow upward, and later in time grow downward. Comparison with fracture models gives only a partial agreement in the final size.

  20. Band structure and transmission characteristics of complex phononic crystals by multi-level substructure scheme

    NASA Astrophysics Data System (ADS)

    Yin, J.; Zhang, S.; Zhang, H. W.; Chen, B. S.

    2015-10-01

    A fast scheme based on the multi-level substructure technique is proposed for the band structure and transmission characteristics calculation of phononic crystals uniformly. The main idea is that finite element models of phononic crystals are divided into several domains by a special multi-level decomposition. For the band structure calculation, the upscaling calculation is employed to condense the internal stiffness matrix of the unit cell into the Bloch boundary. Due to the internal stiffness matrix does not change along with reduced wave vectors in an iteration process, the scheme can reduce the computational scale and improve the efficiency greatly, meanwhile it does not introduce approximation into the traditional finite element model. For the transmission characteristics calculation, the unit cell of the phononic crystal is periodic which is taken as a substructure with the same coefficient matrix. Moreover, the downscaling calculation of internal displacements can be selected flexibly. Some closely watched examples of the three-dimensional locally resonant, defect state of Lamb wave and Bragg waveguide are analyzed. Numerical results indicate that the proposed scheme is efficient and accurate, which may widely be applicable and suitable for complex phononic crystal problems, and provides a reliable numerical tool to optimize and design crystal devices.

  1. Detection of abnormalities in ultrasound lung image using multi-level RVM classification.

    PubMed

    Veeramani, Senthil Kumar; Muthusamy, Ezhilarasi

    2016-06-01

    The classification of abnormalities in ultrasound images is the monitoring tool of fluid to air passage in the lung. In this study, the adaptive median filtering technique is employed for the preprocessing step. The preprocessed image is then extracted the features by the convoluted local tetra pattern, histogram of oriented gradient, Haralick feature extraction and the complete local binary pattern. The extracted features are selected by applying particle swarm optimization and differential evolution feature selection. In the final stage, classifiers namely relevance vector machine (RVM), and multi-level RVM are employed to perform classification of the lung diseases. The diseases respiratory distress syndrome (RDS), transient tachypnea of the new born, meconium aspiration syndrome, pneumothorax, bronchiolitis, pneumonia, and lung cancer are used for training and testing. The experimental analysis exhibits better accuracy, sensitivity, specificity, pixel count and fitness value than the other existing methods. The classification accuracy of above 90% is accomplished by multi-level RVM classifier. The system has been tested with a number of ultrasound lung images and has achieved satisfactory results in classifying the lung diseases. PMID:26135771

  2. An inverter/controller subsystem optimized for photovoltaic applications

    NASA Technical Reports Server (NTRS)

    Pickrell, R. L.; Merrill, W. C.; Osullivan, G.

    1978-01-01

    Conversion of solar array dc power to ac power stimulated the specification, design, and simulation testing of an inverter/controller subsystem tailored to the photovoltaic power source characteristics. This paper discusses the optimization of the inverter/controller design as part of an overall Photovoltaic Power System (PPS) designed for maximum energy extraction from the solar array. The special design requirements for the inverter/controller include: (1) a power system controller (PSC) to control continuously the solar array operating point at the maximum power level based on variable solar insolation and cell temperatures; and (2) an inverter designed for high efficiency at rated load and low losses at light loadings to conserve energy. It must be capable of operating connected to the utility line at a level set by an external controller (PSC).

  3. Geometric Phases, Noise and Non-adiabatic Effects in Multi-level Superconducting Systems

    NASA Astrophysics Data System (ADS)

    Berger, S.; Pechal, M.; Abdumalikov, A. A.; Steffen, L.; Fedorov, A.; Wallraff, A.; Filipp, S.

    2012-02-01

    Geometric phases depend neither on time nor on energy, but only on the trajectory of the quantum system in state space. In previous studies [1], we have observed them in a Cooper pair box qubit, a system with large anharmonicity. We now make use of a superconducting transmon-type qubit with low anharmonicity to study geometric phases in a multi-level system. We measure the contribution of the second excited state to the geometric phase and find very good agreement with theory treating higher levels perturbatively. Furthermore, we quantify non-adiabatic corrections by decreasing the manipulation time in order to optimize our geometric gate. Geometric phases have also been shown to be resilient against adiabatic field fluctuations [2]. Here, we analyze the effect of artificially added noise on the geometric phase for different system trajectories. [1] P. J. Leek et al., Science 318, 1889 (2007) [2] S. Filipp et al., Phys. Rev. Lett. 102, 030404 (2009)

  4. Multi-Grained Level of Detail for Rendering Complex Meshes Using a Hierarchical Seamless Texture Atlas

    SciTech Connect

    Niski, K; Purnomo, B; Cohen, J

    2006-11-06

    Previous algorithms for view-dependent level of detail provide local mesh refinements either at the finest granularity or at a fixed, coarse granularity. The former provides triangle-level adaptation, often at the expense of heavy CPU usage and low triangle rendering throughput; the latter improves CPU usage and rendering throughput by operating on groups of triangles. We present a new multiresolution hierarchy and associated algorithms that provide adaptive granularity. This multi-grained hierarchy allows independent control of the number of hierarchy nodes processed on the CPU and the number of triangles to be rendered on the GPU. We employ a seamless texture atlas style of geometry image as a GPU-friendly data organization, enabling efficient rendering and GPU-based stitching of patch borders. We demonstrate our approach on both large triangle meshes and terrains with up to billions of vertices.

  5. Study of Multi-level Characteristics for 3D Vertical Resistive Switching Memory

    NASA Astrophysics Data System (ADS)

    Bai, Yue; Wu, Huaqiang; Wu, Riga; Zhang, Ye; Deng, Ning; Yu, Zhiping; Qian, He

    2014-07-01

    Three-dimensional (3D) integration and multi-level cell (MLC) are two attractive technologies to achieve ultra-high density for mass storage applications. In this work, a three-layer 3D vertical AlO?/Ta2O5-x/TaOy resistive random access memories were fabricated and characterized. The vertical cells in three layers show good uniformity and high performance (e.g. >1000X HRS/LRS windows, >1010 endurance cycles, >104 s retention times at 125C). Meanwhile, four level MLC is demonstrated with two operation strategies, current controlled scheme (CCS) and voltage controlled scheme (VCS). The switching mechanism of 3D vertical RRAM cells is studied based on temperature-dependent transport characteristics. Furthermore, the applicability of CCS and VCS in 3D vertical RRAM array is compared using resistor network circuit simulation.

  6. Study of Multi-level Characteristics for 3D Vertical Resistive Switching Memory

    PubMed Central

    Bai, Yue; Wu, Huaqiang; Wu, Riga; Zhang, Ye; Deng, Ning; Yu, Zhiping; Qian, He

    2014-01-01

    Three-dimensional (3D) integration and multi-level cell (MLC) are two attractive technologies to achieve ultra-high density for mass storage applications. In this work, a three-layer 3D vertical AlOδ/Ta2O5-x/TaOy resistive random access memories were fabricated and characterized. The vertical cells in three layers show good uniformity and high performance (e.g. >1000X HRS/LRS windows, >1010 endurance cycles, >104 s retention times at 125°C). Meanwhile, four level MLC is demonstrated with two operation strategies, current controlled scheme (CCS) and voltage controlled scheme (VCS). The switching mechanism of 3D vertical RRAM cells is studied based on temperature-dependent transport characteristics. Furthermore, the applicability of CCS and VCS in 3D vertical RRAM array is compared using resistor network circuit simulation. PMID:25047906

  7. Measurement of Low Level Explosives Reaction in Gauged Multi-Dimensional Steven Impact Tests

    SciTech Connect

    Niles, A M; Garcia, F; Greenwood, D W; Forbes, J W; Tarver, C M; Chidester, S K; Garza, R G; Swizter, L L

    2001-05-31

    The Steven Test was developed to determine relative impact sensitivity of metal encased solid high explosives and also be amenable to two-dimensional modeling. Low level reaction thresholds occur at impact velocities below those required for shock initiation. To assist in understanding this test, multi-dimensional gauge techniques utilizing carbon foil and carbon resistor gauges were used to measure pressure and event times. Carbon resistor gauges indicated late time low level reactions 200-540 {micro}s after projectile impact, creating 0.39-2.00 kb peak shocks centered in PBX 9501 explosives discs and a 0.60 kb peak shock in a LX-04 disk. Steven Test modeling results, based on ignition and growth criteria, are presented for two PBX 9501 scenarios: one with projectile impact velocity just under threshold (51 m/s) and one with projectile impact velocity just over threshold (55 m/s). Modeling results are presented and compared to experimental data.

  8. Entanglement and non-Markovianity of a multi-level atom decaying in a cavity

    NASA Astrophysics Data System (ADS)

    Zi-Long, Fan; Yu-Kun, Ren; Hao-Sheng, Zeng

    2016-01-01

    We present a paradigmatic method for exactly studying non-Markovian dynamics of a multi-level V-type atom interacting with a zero-temperature bosonic bath. Special attention is paid to the entanglement evolution and the dynamical non-Markovianity of a three-level V-type atom. We find that the entanglement negativity decays faster and non-Markovianity is smaller in the resonance regions than those in the non-resonance regions. More importantly, the quantum interference between the dynamical non-Markovianities induced by different transition channels is manifested, and the frequency domains for constructive and destructive interferences are found. Project supported by the National Natural Science Foundation of China (Grant Nos. 11275064 and 11075050), the Specialized Research Fund for the Doctoral Program of Higher Education, China (Grant No. 20124306110003), and the Construct Program of the National Key Discipline, China.

  9. Health, policy and geography: insights from a multi-level modelling approach.

    PubMed

    Castelli, Adriana; Jacobs, Rowena; Goddard, Maria; Smith, Peter C

    2013-09-01

    Improving the health and wellbeing of citizens ranks highly on the agenda of most governments. Policy action to enhance health and wellbeing can be targeted at a range of geographical levels and in England the focus has tended to shift away from the national level to smaller areas, such as communities and neighbourhoods. Our focus is to identify the potential for targeting policy interventions at the most appropriate geographical levels in order to enhance health and wellbeing. The rationale is that where variations in health and wellbeing indicators are larger, there may be greater potential for policy intervention targeted at that geographical level to have an impact on the outcomes of interest, compared with a strategy of targeting policy at those levels where relative variations are smaller. We use a multi-level regression approach to identify the degree of variation that exists in a set of health indicators at each level, taking account of the geographical hierarchical organisation of public sector organisations. We find that for each indicator, the proportion of total residual variance is greatest at smaller geographical areas. We also explore the variations in health indicators within a hierarchical level, but across the geographical areas for which public sector organisations are responsible. We show that it is feasible to identify a sub-set of organisations for which unexplained variation in health indicators is significantly greater relative to their counterparts. We demonstrate that adopting a geographical perspective to analyse the variation in indicators of health at different levels offers a potentially powerful analytical tool to signal where public sector organisations, faced increasingly with many competing demands, should target their policy efforts. This is relevant not only to the English context but also to other countries where responsibilities for health and wellbeing are being devolved to localities and communities. PMID:23849280

  10. Health, policy and geography: Insights from a multi-level modelling approach?

    PubMed Central

    Castelli, Adriana; Jacobs, Rowena; Goddard, Maria; Smith, Peter C.

    2013-01-01

    Improving the health and wellbeing of citizens ranks highly on the agenda of most governments. Policy action to enhance health and wellbeing can be targeted at a range of geographical levels and in England the focus has tended to shift away from the national level to smaller areas, such as communities and neighbourhoods. Our focus is to identify the potential for targeting policy interventions at the most appropriate geographical levels in order to enhance health and wellbeing. The rationale is that where variations in health and wellbeing indicators are larger, there may be greater potential for policy intervention targeted at that geographical level to have an impact on the outcomes of interest, compared with a strategy of targeting policy at those levels where relative variations are smaller. We use a multi-level regression approach to identify the degree of variation that exists in a set of health indicators at each level, taking account of the geographical hierarchical organisation of public sector organisations. We find that for each indicator, the proportion of total residual variance is greatest at smaller geographical areas. We also explore the variations in health indicators within a hierarchical level, but across the geographical areas for which public sector organisations are responsible. We show that it is feasible to identify a sub-set of organisations for which unexplained variation in health indicators is significantly greater relative to their counterparts. We demonstrate that adopting a geographical perspective to analyse the variation in indicators of health at different levels offers a potentially powerful analytical tool to signal where public sector organisations, faced increasingly with many competing demands, should target their policy efforts. This is relevant not only to the English context but also to other countries where responsibilities for health and wellbeing are being devolved to localities and communities. PMID:23849280

  11. ARRA-Multi-Level Energy Storage and Controls for Large-Scale Wind Energy Integration

    SciTech Connect

    David Wenzhong Gao

    2012-09-30

    The Project Objective is to design innovative energy storage architecture and associated controls for high wind penetration to increase reliability and market acceptance of wind power. The project goals are to facilitate wind energy integration at different levels by design and control of suitable energy storage systems. The three levels of wind power system are: Balancing Control Center level, Wind Power Plant level, and Wind Power Generator level. Our scopes are to smooth the wind power fluctuation and also ensure adequate battery life. In the new hybrid energy storage system (HESS) design for wind power generation application, the boundary levels of the state of charge of the battery and that of the supercapacitor are used in the control strategy. In the controller, some logic gates are also used to control the operating time durations of the battery. The sizing method is based on the average fluctuation of wind profiles of a specific wind station. The calculated battery size is dependent on the size of the supercapacitor, state of charge of the supercapacitor and battery wear. To accommodate the wind power fluctuation, a hybrid energy storage system (HESS) consisting of battery energy system (BESS) and super-capacitor is adopted in this project. A probability-based power capacity specification approach for the BESS and super-capacitors is proposed. Through this method the capacities of BESS and super-capacitor are properly designed to combine the characteristics of high energy density of BESS and the characteristics of high power density of super-capacitor. It turns out that the super-capacitor within HESS deals with the high power fluctuations, which contributes to the extension of BESS lifetime, and the super-capacitor can handle the peaks in wind power fluctuations without the severe penalty of round trip losses associated with a BESS. The proposed approach has been verified based on the real wind data from an existing wind power plant in Iowa. An intelligent controller that increases battery life within hybrid energy storage systems for wind application was developed. Comprehensive studies have been conducted and simulation results are analyzed. A permanent magnet synchronous generator, coupled with a variable speed wind turbine, is connected to a power grid (14-bus system). A rectifier, a DC-DC converter and an inverter are used to provide a complete model of the wind system. An Energy Storage System (ESS) is connected to a DC-link through a DC-DC converter. An intelligent controller is applied to the DC-DC converter to help the Voltage Source Inverter (VSI) to regulate output power and also to control the operation of the battery and supercapacitor. This ensures a longer life time for the batteries. The detailed model is simulated in PSCAD/EMTP. Additionally, economic analysis has been done for different methods that can reduce the wind power output fluctuation. These methods are, wind power curtailment, dumping loads, battery energy storage system and hybrid energy storage system. From the results, application of single advanced HESS can save more money for wind turbines owners. Generally the income would be the same for most of methods because the wind does not change and maximum power point tracking can be applied to most systems. On the other hand, the cost is the key point. For short term and small wind turbine, the BESS is the cheapest and applicable method while for large scale wind turbines and wind farms the application of advanced HESS would be the best method to reduce the power fluctuation. The key outcomes of this project include a new intelligent controller that can reduce energy exchanged between the battery and DC-link, reduce charging/discharging cycles, reduce depth of discharge and increase time interval between charge/discharge, and lower battery temperature. This improves the overall lifetime of battery energy storages. Additionally, a new design method based on probability help optimize the power capacity specification for BESS and super-capacitors. Recommendations include experimental implementation of the controller and energy storage systems in laboratory environment for further testing and verification, which will help commercialization of the proposed system design and controller.

  12. Gender differences in public and private drinking contexts: a multi-level GENACIS analysis.

    PubMed

    Bond, Jason C; Roberts, Sarah C M; Greenfield, Thomas K; Korcha, Rachael; Ye, Yu; Nayak, Madhabika B

    2010-05-01

    This multi-national study hypothesized that higher levels of country-level gender equality would predict smaller differences in the frequency of women's compared to men's drinking in public (like bars and restaurants) settings and possibly private (home or party) settings. GENACIS project survey data with drinking contexts included 22 countries in Europe (8); the Americas (7); Asia (3); Australasia (2), and Africa (2), analyzed using hierarchical linear models (individuals nested within country). Age, gender and marital status were individual predictors; country-level gender equality as well as equality in economic participation, education, and political participation, and reproductive autonomy and context of violence against women measures were country-level variables. In separate models, more reproductive autonomy, economic participation, and educational attainment and less violence against women predicted smaller differences in drinking in public settings. Once controlling for country-level economic status, only equality in economic participation predicted the size of the gender difference. Most country-level variables did not explain the gender difference in frequency of drinking in private settings. Where gender equality predicted this difference, the direction of the findings was opposite from the direction in public settings, with more equality predicting a larger gender difference, although this relationship was no longer significant after controlling for country-level economic status. Findings suggest that country-level gender equality may influence gender differences in drinking. However, the effects of gender equality on drinking may depend on the specific alcohol measure, in this case drinking context, as well as on the aspect of gender equality considered. Similar studies that use only global measures of gender equality may miss key relationships. We consider potential implications for alcohol related consequences, policy and public health. PMID:20623016

  13. Gender Differences in Public and Private Drinking Contexts: A Multi-Level GENACIS Analysis

    PubMed Central

    Bond, Jason C.; Roberts, Sarah C.M.; Greenfield, Thomas K.; Korcha, Rachael; Ye, Yu; Nayak, Madhabika B.

    2010-01-01

    This multi-national study hypothesized that higher levels of country-level gender equality would predict smaller differences in the frequency of womens compared to mens drinking in public (like bars and restaurants) settings and possibly private (home or party) settings. GENACIS project survey data with drinking contexts included 22 countries in Europe (8); the Americas (7); Asia (3); Australasia (2), and Africa (2), analyzed using hierarchical linear models (individuals nested within country). Age, gender and marital status were individual predictors; country-level gender equality as well as equality in economic participation, education, and political participation, and reproductive autonomy and context of violence against women measures were country-level variables. In separate models, more reproductive autonomy, economic participation, and educational attainment and less violence against women predicted smaller differences in drinking in public settings. Once controlling for country-level economic status, only equality in economic participation predicted the size of the gender difference. Most country-level variables did not explain the gender difference in frequency of drinking in private settings. Where gender equality predicted this difference, the direction of the findings was opposite from the direction in public settings, with more equality predicting a larger gender difference, although this relationship was no longer significant after controlling for country-level economic status. Findings suggest that country-level gender equality may influence gender differences in drinking. However, the effects of gender equality on drinking may depend on the specific alcohol measure, in this case drinking context, as well as on the aspect of gender equality considered. Similar studies that use only global measures of gender equality may miss key relationships. We consider potential implications for alcohol related consequences, policy and public health. PMID:20623016

  14. Multi-level stressor analysis from the DNA/biochemical level to community levels in an urban stream and integrative health response (IHR) assessments.

    PubMed

    Lee, Jae Hoon; Kim, Joon Ha; Oh, Hee-Mock; An, Kwang-Guk

    2013-01-01

    The objectives of this study were to identify multi-level stressors at the DNA/biochemical level to the community level in fish in an urban stream and to develop an integrative health response (IHR) model for ecological health diagnosis. A pristine control site (S (c) ) and an impacted site (S (i) ) were selected from among seven pre-screened sites studied over seven years. Various chemical analyses indicated that nutrient enrichment (Nitrogen, Phosphorus) and organic pollution were significantly greater (t > 8.783, p < 0.01) at the S (i) site compared to the S (c) site. Single-cell gel electrophoresis (comet assays) of DNA-level impairment indicated significantly (t = 5.678, p < 0.01) greater tail intensity, expressed as % tail-DNA, at the S (i) site and genotoxic responses were detected in the downstream reach. Ethoxyresorufin-O-deethylase (EROD) assays, as a physiological bioindicator, were 2.8-fold higher (p < 0.05, NK-test after ANOVA) at the S (i) site. Tissue analysis using a necropsy-based health assessment index (NHAI) showed distinct internal organ disorders in three tissues, i.e., liver, kidney, and gill, at the S (i) site. Population-level analysis using the sentinel species Zacco platypus showed that the regression coefficient (b) was 3.012 for the S (i) site and 2.915 for the S (c) site, indicating population skewness in the downstream reach. Community-level health was impaired at the S (i) site based on an index of biological integrity (IBI), and physical habitat modifications were identified by a qualitative habitat evaluation index (QHEI). Overall, the model values for the integrative health response (IHR), developed using the star plot approach, were 3.22 (80.5%) at the S (c) site and 0.74 (18.5%) at the S (i) site, indicating that, overall, ecological health impairments were evident in the urban reach. Our study was based on multi-level approaches using biological organization and the results suggest that there is a pivotal point of linkage between mechanistic understanding and real ecological consequences of environmental stressors. PMID:23043344

  15. Introduction of temporal sub-stepping in the Multi-Level Multi-Domain semi-implicit Particle-In-Cell code Parsek2D-MLMD

    NASA Astrophysics Data System (ADS)

    Innocenti, M. E.; Beck, A.; Ponweiser, T.; Markidis, S.; Lapenta, G.

    2015-04-01

    In this paper, the introduction of temporal sub-stepping in Multi-Level Multi-Domain (MLMD) simulations of plasmas is discussed. The MLMD method addresses the multi-scale nature of space plasmas by simulating a problem at different levels of resolution. A large-domain "coarse grid" is simulated with low resolution to capture large-scale, slow processes. Smaller scale, local processes are obtained through a "refined grid" which uses higher resolution. Very high jumps in the resolution used at the different levels can be achieved thanks to the Implicit Moment Method and appropriate grid interlocking operations. Up to now, the same time step was used at all the levels. Now, with temporal sub-stepping, the different levels can also benefit from the use of different temporal resolutions. This saves further resources with respect to "traditional" simulations done using the same spatial and temporal stepping on the entire domain. It also prevents the levels from working at the limits of the stability condition of the Implicit Moment Method. The temporal sub-stepping is tested with simulations of magnetic reconnection in space. It is shown that, thanks to the reduced costs of MLMD simulations with respect to single-level simulations, it becomes possible to verify with realistic mass ratios scaling laws previously verified only for reduced mass ratios. Performance considerations are also provided.

  16. Improved estimates of upper-ocean warming and multi-decadal sea-level rise.

    PubMed

    Domingues, Catia M; Church, John A; White, Neil J; Gleckler, Peter J; Wijffels, Susan E; Barker, Paul M; Dunn, Jeff R

    2008-06-19

    Changes in the climate system's energy budget are predominantly revealed in ocean temperatures and the associated thermal expansion contribution to sea-level rise. Climate models, however, do not reproduce the large decadal variability in globally averaged ocean heat content inferred from the sparse observational database, even when volcanic and other variable climate forcings are included. The sum of the observed contributions has also not adequately explained the overall multi-decadal rise. Here we report improved estimates of near-global ocean heat content and thermal expansion for the upper 300 m and 700 m of the ocean for 1950-2003, using statistical techniques that allow for sparse data coverage and applying recent corrections to reduce systematic biases in the most common ocean temperature observations. Our ocean warming and thermal expansion trends for 1961-2003 are about 50 per cent larger than earlier estimates but about 40 per cent smaller for 1993-2003, which is consistent with the recognition that previously estimated rates for the 1990s had a positive bias as a result of instrumental errors. On average, the decadal variability of the climate models with volcanic forcing now agrees approximately with the observations, but the modelled multi-decadal trends are smaller than observed. We add our observational estimate of upper-ocean thermal expansion to other contributions to sea-level rise and find that the sum of contributions from 1961 to 2003 is about 1.5 +/- 0.4 mm yr(-1), in good agreement with our updated estimate of near-global mean sea-level rise (using techniques established in earlier studies) of 1.6 +/- 0.2 mm yr(-1). PMID:18563162

  17. Detailed Modeling, Design, and Evaluation of a Scalable Multi-level Checkpointing System

    SciTech Connect

    Moody, A T; Bronevetsky, G; Mohror, K M; de Supinski, B R

    2010-04-09

    High-performance computing (HPC) systems are growing more powerful by utilizing more hardware components. As the system mean-time-before-failure correspondingly drops, applications must checkpoint more frequently to make progress. However, as the system memory sizes grow faster than the bandwidth to the parallel file system, the cost of checkpointing begins to dominate application run times. A potential solution to this problem is to use multi-level checkpointing, which employs multiple types of checkpoints with different costs and different levels of resiliency in a single run. The goal is to design light-weight checkpoints to handle the most common failure modes and rely on more expensive checkpoints for less common, but more severe failures. While this approach is theoretically promising, it has not been fully evaluated in a large-scale, production system context. To this end we have designed a system, called the Scalable Checkpoint/Restart (SCR) library, that writes checkpoints to storage on the compute nodes utilizing RAM, Flash, or disk, in addition to the parallel file system. We present the performance and reliability properties of SCR as well as a probabilistic Markov model that predicts its performance on current and future systems. We show that multi-level checkpointing improves efficiency on existing large-scale systems and that this benefit increases as the system size grows. In particular, we developed low-cost checkpoint schemes that are 100x-1000x faster than the parallel file system and effective against 85% of our system failures. This leads to a gain in machine efficiency of up to 35%, and it reduces the the load on the parallel file system by a factor of two on current and future systems.

  18. Towards Consistent Characterization of Quality and Uncertainty in Multi-sensor Aerosol Level 3 Satellite Data

    NASA Astrophysics Data System (ADS)

    Leptoukh, G. G.

    2010-12-01

    Climate models and various environmental monitoring and protection applications have been increasingly relying on satellite measurements. However, the user communities generally prefer not to deal with the complexities and peculiarities of Level 2 (swath) data from the different sensors. Instead, these users seek good quality gridded contiguous (no gaps) satellite data (Level 3), with uncertainties provided for each grid cell. There are various issues in quality and uncertainty associated with Level 3 satellite data, for which other communities (e.g., sea-surface temperature and precipitation) have developed specific solutions, based on their multi-satellite/sensor/year experience. The aerosol community will also benefit from addressing these issues and leveraging the lessons learned from other communities. Our objective is to develop a framework for aerosol data users to systematically characterize, capture, and provision quality and uncertainties in Level 3 satellite data. In particular, we note the semantic differences in quality/bias/uncertainty at the pixel, granule, product, and record levels. We outline various factors contributing to uncertainty or error budget: (1) physical factors (e.g., instrument, retrieval algorithm, aerosol spatial and temporal variability); (2) input errors associated with ancillary data used by the retrieval algorithm; (3) classification errors resulting from erroneous flagging of the data; (4) simulation errors resulting from the geophysical model used for the retrieval; and (5) sampling errors resulting from the averaging within the retrieval footprint. We describe the errors introduced by Level 2 to Level 3 and Level 3 to Level 4 processing steps, including gridding, aggregation, merging and analysis algorithm errors (e.g., representation, bias correction, and gap interpolation). We outline various methods for propagating (1) validation results from just a few points to global data uncertainty and (2) calibration and algorithm uncertainties to Level 3 gridded data. We attempt to capture requirements for quality vs. coverage for the needs of different communities. Finally, we address the question of how to label Level 3 data as validated. The larger community goal is to come up with recommendations for consistent generation of Levels 3 and 4 aerosol products, and consistent characterization of quality and uncertainty.

  19. Multi-level behaviours in agent-based simulation: colonic crypt cell populations

    NASA Astrophysics Data System (ADS)

    Chen, Chih-Chun; Nagl, Sylvia B.; Clack, Christopher D.

    Agent-based modelling and simulation is now beginning to establish itself as a suitable technique for studying biological systems. However, a major issue in using agent-based simulations to study complex systems such as those in Systems Biology is the fact that simulations are `opaque'. While we have knowledge of individuals' behaviour through agent rules and have techniques for evaluating global behaviour by aggregating the states of individuals, methods for identifying the interactive mechanisms giving rise to this global behaviour are lacking. Formulating precise hypotheses about these multi-level behaviours is also difficult without an established formalism for describing them. The complex event formalism allows relationships between agent-rule-generated events to be defined so that behaviours at different levels of abstraction to be described. Complex event types define categories of these behaviours, which can then be detected in simulation, giving us computational method for distinguishing between alternative interactive mechanisms underlying a higher level behaviour. We apply the complex event formalism to an agent-based model of cell populations in the colonic crypt and demonstrate how competition and selection events can be identified in simulation at both the individual and clonal level, allowing us to computationally test hypotheses about the interactive mechanisms underlying a clone's success.

  20. Multi-level trophic cascades in a heavily exploited open marine ecosystem

    PubMed Central

    Casini, Michele; Lvgren, Johan; Hjelm, Joakim; Cardinale, Massimiliano; Molinero, Juan-Carlos; Kornilovs, Georgs

    2008-01-01

    Anthropogenic disturbances intertwined with climatic changes can have a large impact on the upper trophic levels of marine ecosystems, which may cascade down the food web. So far it has been difficult to demonstrate multi-level trophic cascades in pelagic marine environments. Using field data collected during a 33-year period, we show for the first time a four-level community-wide trophic cascade in the open Baltic Sea. The dramatic reduction of the cod (Gadus morhua) population directly affected its main prey, the zooplanktivorous sprat (Sprattus sprattus), and indirectly the summer biomass of zooplankton and phytoplankton (top-down processes). Bottom-up processes and climatehydrological forces had a weaker influence on sprat and zooplankton, whereas phytoplankton variation was explained solely by top-down mechanisms. Our results suggest that in order to dampen the occasionally harmful algal blooms of the Baltic, effort should be addressed not only to control anthropogenic nutrient inputs but also to preserve structure and functioning of higher trophic levels. PMID:18460432

  1. Segmentation of hand radiographs by using multi-level connected active appearance models

    NASA Astrophysics Data System (ADS)

    Kauffman, Joost A.; Slump, Cornelis H.; Bernelot Moens, Hein J.

    2005-04-01

    Robust and accurate segmentation methods are important for the computerized evaluation of medical images. For treatment of rheumatoid arthritis, joint damage assessment in radiographs of hands is frequently used for monitoring disease progression. Current clinical scoring methods are based on visual measurements that are time-consuming and subject to intra and inter-reader variance. A solution may be found in the development of partially automated assessment procedures. This requires reliable segmentation algorithms. Our work demonstrates a segmentation method based on multiple connected active appearance models (AAM) with multiple search steps using different quality levels. The quality level can be regulated by setting the image resolution and the number of landmarks in the AAMs. We performed experiments using two models of different quality levels for shape and texture information. Both models included AAMs for the carpal region, the metacarpals, and all phalanges. By starting an iterative search with the faster, low-quality model, we were able to determine the initial parameters of the second, high-quality model. After the second search, the results showed successful segmentation for 22 of 30 test images. For these images, 70% of the landmarks were found within 1.3 mm difference from manual placement by an expert. The multi-level search approach resulted in a reduction of 50% in calculation time compared to a search using a single model. Results are expected to improve when the model is refined by increasing the number of training examples and the resolution of the models.

  2. Identification of potential COPD genes based on multi-omics data at the functional level.

    PubMed

    Liu, Zhe; Li, Wan; Lv, Junjie; Xie, Ruiqiang; Huang, Hao; Li, Yiran; He, Yuehan; Jiang, Jing; Chen, Binbin; Guo, Shanshan; Chen, Lina

    2016-01-15

    Chronic obstructive pulmonary disease (COPD) is a complex disease, which involves dysfunctions in multi-omics. The changes in biological processes, such as adhesion junction, signaling transduction, transcriptional regulation, and cell proliferation, will lead to the occurrence of COPD. A novel systematic approach MMMG (Methylation-MicroRNA-MRNA-GO) was proposed to identify potential COPD genes by integrating function information with a methylation profile, a microRNA expression profile and an mRNA expression profile. 8 co-functional classes and 102 potential COPD genes were identified. These genes displayed a high performance in classifying COPD patients and normal samples, revealed COPD-related pathways, and have been confirmed to be associated with COPD by Matthews correlation coefficient (MCC)-values, literature, an independent data set, and pathways. The MMMG method that analyzed multi-omics data at the functional level could effectively identify potential COPD genes. These potential COPD genes would provide in-depth insights into understanding the complexity of COPD genome landscapes, improve the early diagnostics, and guide new efforts to develop therapeutics in the future. PMID:26575263

  3. The geometry of ?-invertible sheaves

    NASA Astrophysics Data System (ADS)

    Kwok, Stephen

    2014-12-01

    Using the fact that ?-invertible sheaves can be interpreted as locally free sheaves of modules for the super skew field D, we give a new construction of the ?-projective superspace P?,Bn over affine k superschemes B, k an algebraically closed field. We characterize morphisms into P?,Bn and give a new interpretation of the composition of ?-invertible sheaves in terms of the algebra of D.

  4. Inverter Ground Fault Overvoltage Testing

    SciTech Connect

    Hoke, Andy; Nelson, Austin; Chakraborty, Sudipta; Chebahtah, Justin; Wang, Trudie; McCarty, Michael

    2015-08-12

    This report describes testing conducted at NREL to determine the duration and magnitude of transient overvoltages created by several commercial PV inverters during ground fault conditions. For this work, a test plan developed by the Forum on Inverter Grid Integration Issues (FIGII) has been implemented in a custom test setup at NREL. Load rejection overvoltage test results were reported previously in a separate technical report.

  5. Interface-induced two-step RESET for filament-based multi-level resistive memory

    NASA Astrophysics Data System (ADS)

    Yuan, Fang; Shen, Shanshan; Zhang, Zhigang; Pan, Liyang; Xu, Jun

    2016-03-01

    In this paper, a two-step RESET switching behavior of Ag/Al2O3/HfO2/Pt bilayer resistive random access memory (RRAM) devices is investigated. The interface between the two oxide layers is responsible for the special two-step RESET switching. When the conducting filaments have ruptured in the lower layer, the interface can protect the Ag ions of the filaments from breaking in the upper layer due to the trapped charges or defects at the interface. Therefore, a stable middle resistance state (MRS) is realized and the device exhibits a terrace-like I-V curve during the RESET operations. A filament-based switching mechanism combined with the electron hopping theory is proposed to explain the physical nature of the two-step RESET behavior. Furthermore, a good multi-level resistive switching performance with excellent endurance and retention reliability is obtained.

  6. A multi level system design for vigilance measurement based on head posture estimation and eyes blinking

    NASA Astrophysics Data System (ADS)

    Teyeb, Ines; Jemai, Olfa; Zaied, Mourad; ben Amar, Chokri

    2015-12-01

    Driving security is an important task for human society. The major challenge in the field of accident avoidance systems is the driver vigilance monitoring. The lack of vigilance can be noticed by various ways, such as, fatigue, drowsiness and distraction. Hence, the need of a reliable driver's vigilance decrease detection system which can alert drivers before a mishap happens. In this paper, we present a novel approach for vigilance estimation based on multilevel system by combining head movement analysis and eyes blinking. We have used Viola and Jones algorithm to analyse head movement and a classification system using wavelet networks for eyelid closure measuring. The contribution of our application is classifiying the vigilance state at multi level. This is different from the binary-class (awakening or hypovigilant state) existing in most popular systems.

  7. A multi-level pore-water sampler for permeable sediments

    USGS Publications Warehouse

    Martin, J.B.; Hartl, K.M.; Corbett, D.R.; Swarzenski, P.W.; Cable, J.E.

    2003-01-01

    The construction and operation of a multi-level piezometer (multisampler) designed to collect pore water from permeable sediments up to 230 cm below the sediment-water interface is described. Multisamplers are constructed from 1 1/2 inch schedule 80 PVC pipe. One-quarter-inch flexible PVC tubing leads from eight ports at variable depths to a 1 1/2 inch tee fitting at the top of the PVC pipe. Multisamplers are driven into the sediments using standard fence-post drivers. Water is pumped from the PVC tubing with a peristaltic pump. Field tests in Banana River Lagoon, Florida, demonstrate the utility of multisamplers. These tests include collection of multiple samples from the permeable sediments and reveal mixing between shallow pore water and overlying lagoon water.

  8. An alternative construction of internodons: the emergence of a multi-level tree of life.

    PubMed

    Alexander, Samuel A; de Bruin, Arie; Kornet, D J

    2015-01-01

    Internodons are a formalization of Hennig's concept of species. We present an alternative construction of internodons imposing a tree structure on the genealogical network. We prove that the segments (trivial unary trees) from this tree structure are precisely the internodons. We obtain the following spin-offs. First, the generated tree turns out to be an organismal tree of life. Second, this organismal tree is homeomorphic to the phylogenetic Hennigian species tree of life, implying the discovery of a multi-level tree of life: this phylogenetic tree can be obtained by zooming out from the organismal tree, or conversely, the organismal tree of life can be generated by expanding the phylogenetic nodes into unary trees. Finally, the definition of the organismal tree allows an efficient algorithmic transformation of a given genealogical network into its corresponding phylogenetic species tree of life. The latter will be presented in a separate paper. PMID:25515028

  9. Multi-level intervention to prevent influenza infections in older low income and minority adults.

    PubMed

    Schensul, Jean J; Radda, Kim; Coman, Emil; Vazquez, Elsie

    2009-06-01

    In this paper we describe a successful multi-level participatory intervention grounded in principles of individual and group empowerment, and guided by social construction theory. The intervention addressed known and persistent inequities in influenza vaccination among African American and Latino older adults, and associated infections, hospitalizations and mortality. It was designed to increase resident ability to make informed decisions about vaccination, and to build internal and external infrastructure to support sustainability over time. The intervention brought a group of social scientists, vaccine researchers, geriatricians, public health nurses, elder services providers and advocates together with senior housing management and activist African American and Latino residents living in public senior housing in a small east coast city. Two buildings of equal size and similar ethnic composition were randomized as intervention and control buildings. Pre and post intervention surveys were conducted in both buildings, measuring knowledge, attitudes and peer norms. Processes and outcomes were documented at four levels: Influenza Strategic Alliance (macro and exo levels), building management (meso level), building resident committee (meso level) and individual residents. The Influenza Strategic Alliance (I.S.A.) provided ongoing resources, information and vaccine; the building management provided economic and other in-kind resources and supported residents to continue flu clinics in the building. The V.I.P. Resident Committee conducted flu campaigns with flu clinics in English and Spanish. The vaccination rate in the intervention building at post test exceeded the study goal of 70% and showed a significant improvement over the control building. The intervention achieved desired outcomes at all four levels and resulted in a significant increase in influenza vaccination, and improvements in pro-vaccination knowledge, beliefs, and understanding of health consequences. PMID:19387822

  10. Roles of Upper-Level Processes in the Multi-Intensity Changes of Hurricane Sandy (2012)

    NASA Astrophysics Data System (ADS)

    Shin, J. H.; Zhang, D. L.

    2014-12-01

    The multi-intensity changes of Hurricane Sandy (2012) are examined by using a cloud resolving WRF model. An analysis of Sandy's life cycle shows four distinct stages: (1) rapid deepening, (2) weakening, (3) deepening with little intensification of rotational wind, and (4) re-intensification of vortex winds. Results from the model simulations indicate that Sandy's multi-intensity changes are closely related to (i) changes in the magnitude and direction of environmental vertical wind shear (VWS), (ii) upper-tropospheric warming associated with deep convection in the core region, (iii) lower-stratospheric warmth as the storm moves poleward into lower-tropopause regions, and (iv) the possible roles of inertial instability in the upper outflow regions as approaching a upper-level trough/jet stream. Specifically, Sandy intensifies steadily since October 24 as it moves over warm SST surface from Caribbean Sea to Cuba Island. After the storm passes Cuba Island, its warm core begins to tilt under the influence of increasing VWS as it approaches to an upper-level subtropical jet stream, leading to the weakening of the storm. After October 27, Sandy deepens as it moves far away from the upper-level jet core VWS, though over a colder SST surface. By hydrostatic reasoning, we find that during the 3rd stage Sandy's deepening results partly from the stacked upper-level warming in the core region but more from low stratospheric warmth as it moves to higher latitudes with lower tropopause height. Unlike the former scenario, this stratospheric warmth occurs over a meso-alpha-scale region encompassing the storm, thus causing widespread surface pressure falls. This explains why the rotational wind of Sandy shows little intensity changes while its central pressure keeps falling. During the final stage, organized deep convection in the core region increases upper-level tropospheric warming, leading to both the deepening of central pressure and re-intensification of rotational winds. It appears that the presence of inertial instability in the upper outflow channel may play some roles in the intensification of the storm. It is concluded that the intensity changes of Sandy are not only influenced by the tropospheric processes but also by the lower-stratospheric warmth, especially after moving into the mid-latitudes.

  11. Multi-level significance of vulnerability indicators. Case study: Eastern Romania

    NASA Astrophysics Data System (ADS)

    Stanga, I. C.; Grozavu, A.

    2012-04-01

    Vulnerability assessment aims, most frequently, to emphasize internal fragility of a system comparing to a reference standard, to similar systems or in relation to a given hazard. Internal fragility, either biophysical or structural, may affect the capacity to predict, to prepare for, to cope with or to recover from a disaster. Thus, vulnerability is linked to resilience and adaptive capacity. From local level to global one, vulnerability factors and corresponding indicators are different and their significance must be tested and validated in a well-structured conceptual and methodological framework. In this paper, the authors aim to show the real vulnerability of rural settlements in Eastern Romania in a multi-level approach. The research area, Tutova Hills, counts about 3421 sq.km and more than 200.000 inhabitants in 421 villages characterized by deficient accessibility, lack of endowments, subsistential agriculture, high pressure on natural environment (especially on forest and soil resources), poverty and aging process of population. Factors that could influence the vulnerability of these rural settlements have been inventoried and assigned into groups through a cluster analysis: habitat and technical urban facilities, infrastructure, economical, social and demographical indicators, environment quality, management of emergency situations etc. Firstly, the main difficulty was to convert qualitative variable in quantitative indicators and to standardize all values to make possible mathematical and statistical processing of data. Secondly, the great variability of vulnerability factors, their different measuring units and their high amplitude of variation require different method of standardization in order to obtain values between zero (minimum vulnerability) and one (maximum vulnerability). Final vulnerability indicators were selected and integrated in a general scheme, according to their significance resulted from an appropriate factor analysis: linear and logistic regression, varimax rotation, multiple-criteria decision analysis, weight of evidence, multi-criteria evaluation method etc. The approach started from the local level which allows a functional and structural analysis and was progressively translated to an upper level and to a spatial analysis. The model shows that changing the level of analysis diminishes the functional significance of some indicators and increases the capacity of discretization in the case of others, highlighting the spatial and functional complexity of vulnerability.

  12. Post-stroke balance rehabilitation under multi-level electrotherapy: a conceptual review

    PubMed Central

    Dutta, Anirban; Lahiri, Uttama; Das, Abhijit; Nitsche, Michael A.; Guiraud, David

    2014-01-01

    Stroke is caused when an artery carrying blood from heart to an area in the brain bursts or a clot obstructs the blood flow thereby preventing delivery of oxygen and nutrients. About half of the stroke survivors are left with some degree of disability. Innovative methodologies for restorative neurorehabilitation are urgently required to reduce long-term disability. The ability of the nervous system to respond to intrinsic or extrinsic stimuli by reorganizing its structure, function, and connections is called neuroplasticity. Neuroplasticity is involved in post-stroke functional disturbances, but also in rehabilitation. It has been shown that active cortical participation in a closed-loop brain machine interface (BMI) can induce neuroplasticity in cortical networks where the brain acts as a controller, e.g., during a visuomotor task. Here, the motor task can be assisted with neuromuscular electrical stimulation (NMES) where the BMI will act as a real-time decoder. However, the cortical control and induction of neuroplasticity in a closed-loop BMI is also dependent on the state of brain, e.g., visuospatial attention during visuomotor task performance. In fact, spatial neglect is a hidden disability that is a common complication of stroke and is associated with prolonged hospital stays, accidents, falls, safety problems, and chronic functional disability. This hypothesis and theory article presents a multi-level electrotherapy paradigm toward motor rehabilitation in virtual reality that postulates that while the brain acts as a controller in a closed-loop BMI to drive NMES, the state of brain can be can be altered toward improvement of visuomotor task performance with non-invasive brain stimulation (NIBS). This leads to a multi-level electrotherapy paradigm where a virtual reality-based adaptive response technology is proposed for post-stroke balance rehabilitation. In this article, we present a conceptual review of the related experimental findings. PMID:25565937

  13. Post-stroke balance rehabilitation under multi-level electrotherapy: a conceptual review.

    PubMed

    Dutta, Anirban; Lahiri, Uttama; Das, Abhijit; Nitsche, Michael A; Guiraud, David

    2014-01-01

    Stroke is caused when an artery carrying blood from heart to an area in the brain bursts or a clot obstructs the blood flow thereby preventing delivery of oxygen and nutrients. About half of the stroke survivors are left with some degree of disability. Innovative methodologies for restorative neurorehabilitation are urgently required to reduce long-term disability. The ability of the nervous system to respond to intrinsic or extrinsic stimuli by reorganizing its structure, function, and connections is called neuroplasticity. Neuroplasticity is involved in post-stroke functional disturbances, but also in rehabilitation. It has been shown that active cortical participation in a closed-loop brain machine interface (BMI) can induce neuroplasticity in cortical networks where the brain acts as a controller, e.g., during a visuomotor task. Here, the motor task can be assisted with neuromuscular electrical stimulation (NMES) where the BMI will act as a real-time decoder. However, the cortical control and induction of neuroplasticity in a closed-loop BMI is also dependent on the state of brain, e.g., visuospatial attention during visuomotor task performance. In fact, spatial neglect is a hidden disability that is a common complication of stroke and is associated with prolonged hospital stays, accidents, falls, safety problems, and chronic functional disability. This hypothesis and theory article presents a multi-level electrotherapy paradigm toward motor rehabilitation in virtual reality that postulates that while the brain acts as a controller in a closed-loop BMI to drive NMES, the state of brain can be can be altered toward improvement of visuomotor task performance with non-invasive brain stimulation (NIBS). This leads to a multi-level electrotherapy paradigm where a virtual reality-based adaptive response technology is proposed for post-stroke balance rehabilitation. In this article, we present a conceptual review of the related experimental findings. PMID:25565937

  14. Multi-level femoral morphology and mechanical properties of rats of different ages.

    PubMed

    Zhang, Rui; Gong, He; Zhu, Dong; Ma, Renshi; Fang, Juan; Fan, Yobo

    2015-07-01

    A macro-micro-nano-multi-level study was conducted to explore age-related structural and mechanical properties of bone, as well as the effects of aging on bone properties. A total of 70 male Wistar rats were used, ranging in the ages of 1, 3, 5, 7, 9, 11, 14, 15, 16, and 17 months (n = 7/age group). After micro-computed tomography (CT) scanning, longitudinal cortical bone specimens with a length of 5mm were cut along the femoral shaft axis from left femur shafts for mechanical testing, and the cross-sectional areas were measured. The macro-mechanical properties obtained in mechanical testing and microarchitecture parameters measured by micro-CT were significantly correlated with the animal age (r(2) = 0.96, p < 0.001). Scanning electron microscopy was used for detecting the microarchitecture features of the fractured surfaces, which exhibited age-related plate-fibrous-mixed fibrous-plate texture, resulting in changes in macro-mechanical properties (r(2) > 0.90, p < 0.001). The mineral phase of the left femoral shaft and head was analyzed by atomic force microscopy. Longitudinal and transverse trabecular bone tissues, as well as longitudinal cortical bone tissue, were used for nanoindentation test, and the chemical composition was evaluated by quantitative chemical analyses. The correlations between mineral content and bone material properties (i.e., elastic properties of the bone tissue and size and roughness of bone mineral grains) were highly significant (r > 0.95, p < 0.001). Multi-level femur morphology, mechanical property, and mineral content were significantly correlated with the animal age. The correlations between bone mineral content and bone material morphological and mechanical properties may partly explain the increase in bone fragility with aging, which will provide a theoretical basis for the investigation of age-related bone properties in clinics. PMID:25857690

  15. Multi-level aspects of social cohesion of secondary schools and pupils' feelings of safety.

    PubMed

    Mooij, Ton; Smeets, Ed; de Wit, Wouter

    2011-09-01

    BACKGROUND. School safety and corresponding feelings of both pupils and school staff are beginning to receive more and more attention. The social cohesion characteristics of a school may be useful in promoting feelings of safety, particularly in pupils. AIMS. To conceptualize theoretically, and check empirically a two-level model of social cohesion between and within schools, in order to explain a pupil's feelings of safety at school. SAMPLES. Data were collected aided by a national Dutch survey in secondary education carried out via the Internet. In 2008, digital questionnaires were completed by about 78,800 pupils, 6,200 teachers and educational support staff, and 600 school managers. METHODS. Data were checked for reliability and representativity. Social cohesion was indicated by self-reported measures of individual pupils and by aggregating scale and item scores of school managers, teachers, and other support staff within schools. Multi-level analysis using individual pupil data and school-level data was performed using MLwiN. RESULTS. A pupil's age, educational attainment level, experience of mild physical violence, prosocial rules of conduct and joint control of these rules, and school measures against playing truant, show positive influences on a pupil's feelings of safety at school. Negative influences are exerted by not feeling most at home in The Netherlands, peers taking drugs and weapons into school, and by experiencing social violence, severe physical violence, and sexual violence. Negative school effects exist simultaneously in severe physical violence experienced by teachers and other staff, and in curriculum differentiation applied by teachers and other staff; a positive school effect is school size. Some interaction effects between pupil and school-level variables were explored. CONCLUSIONS. The variance at school level is relatively low compared with the variance at pupil level. However, a much higher percentage of variance at school level than at pupil level is explained with respect to the pupils' feelings of safety at school. The resulting two-level model also reflects the streaming of pupils in Dutch secondary schools. To improve school safety, the national results emphasize the need to enhance prosocial behaviour rules and to enhance the shared control of these rules between teachers and pupils. They also emphasize the need for the school to take measures that prevent truancy and redefine curriculum differentiation procedures. National educational policy and research can combine efforts to assist schools in developing reliable and valid procedures to increase effectively safety in and around schools. PMID:21770911

  16. Ecological relevance of Sentinels' biomarker responses: a multi-level approach.

    PubMed

    Seabra Pereira, Camilo D; Abessa, Denis M S; Choueri, Rodrigo B; Almagro-Pastor, Victor; Cesar, Augusto; Maranho, Luciane A; Martín-Díaz, María Laura; Torres, Ronaldo J; Gusso-Choueri, Paloma K; Almeida, João E; Cortez, Fernando S; Mozeto, Antonio A; Silbiger, Helcy L N; Sousa, Eduinetty C P M; Del Valls, Tommas Angel; Bainy, Afonso C D

    2014-05-01

    In response to the need for more sensitive and rapid indicators of environmental quality, sublethal effects on the lowest levels of biological organization have been investigated. The ecological relevance of these responses assumes a prevailing role to assure effectiveness as indicator of ecological status. This study aimed to investigate the linkages between biomarker responses of caged bivalves and descriptive parameters of macrobenthic community structure. For this purpose a multi-level environmental assessment of marine and estuarine zones was performed in São Paulo coast, Brazil. Multivariate analysis was applied to identify linkages between biological responses and ecological indices, as well as to characterizing the studied stations. Individuals of the marine mussel Perna perna caged along Santos Bay showed signs of oxidative stress, lysosomal membrane destabilization, histological alterations and reduced embryonic development. The estuarine oyster Crassostrea rhizophorae caged along Santos Port Channel showed alterations on biotransformation enzymes and antioxidant system, DNA damage and lysosomal membrane destabilization. The benthic community analysis showed reduced richness and diversity in the same areas of the Santos bay and estuary where biomarker responses were altered. Our results revealed that xenobiotics are inducing physiological stress, which may lead to changes of the benthic community structure and deterioration of the ecological status over time. Integrating biomarker responses and ecological indexes improved certainty that alterations found at community level could be related to xenobiotic as stressors, which was very useful to improve the discriminatory power of the environmental assessment. PMID:24314371

  17. A multi-level data-flow architecture for signal and data processing applications. Final report

    SciTech Connect

    Gaudiot, J.L.

    1993-09-02

    A grant was awarded to us by the Department of Energy, Office of Energy Research, in May 1987 to support the design and performance analysis of a large grain data-driven multiprocessor system for numerical applications. The basic idea of the work is to apply the data-driven principles of execution at a more appropriate level than conventional ``atomic`` instructions. For this purpose, a level such as that of vector operations was under study. This document represents the final report concerning the results of the research supported by this grant. The goals of the project entailed an analysis of Partial Differential Equation solvers on data-driven environments, a preliminary design of our multi-level architecture, an in-depth study of some of the mechanisms of execution, and a design of the software environment. As enumerated in the original proposal, our work has yielded results in three different domain: Specifications of the application programs; design of the general concepts of the architecture and simulation; implementation of a translating environment; and we discuss each of the above items and examine specific research results.

  18. Community participation in two vaccination trials in slums of Kolkata, India: a multi-level analysis.

    PubMed

    Ali, Mohammad; Sur, Dipika; Lopez, Anna Lena; Kanungo, Suman; Ochiai, R Leon; Manna, Byomkesh; Kim, Deok Ryun; Deen, Jacqueline; Bhattacharya, Sujit K; Clemens, John D

    2010-10-01

    This study aims at understanding the individual and community-level characteristics that influenced participation in two consecutive vaccine trials (typhoid and cholera) in urban slums of Kolkata, India. The study area was divided into 80 geographic clusters (communities), with 59,533 subjects aged > or = 2 years for analysis. A multi-level model was employed in which the individuals were seen nested within the cluster. Rates of participation in both the trials were nearly the same; those who participated in the initial trial were likely to participate in the subsequent cholera vaccine trial. Communities with predominantly Hindu population, lower percentage of households with an educated household head, or lower percentage of households owning a motorbike had higher participation than their counterparts. At individual scale, higher participation was observed among younger subjects, females, and individuals from households with a household head who had no or minimal education. Geographic patterns were also observed in participation in the trials. The results illustrated that participation in the trial was mostly influenced by various individual and community-level factors, which need to be addressed for a successful vaccination campaign. PMID:20941896

  19. Multi-item direct behavior ratings: Dependability of two levels of assessment specificity.

    PubMed

    Volpe, Robert J; Briesch, Amy M

    2015-09-01

    Direct Behavior Rating-Multi-Item Scales (DBR-MIS) have been developed as formative measures of behavioral assessment for use in school-based problem-solving models. Initial research has examined the dependability of composite scores generated by summing all items comprising the scales. However, it has been argued that DBR-MIS may offer assessment of 2 levels of behavioral specificity (i.e., item-level, global composite-level). Further, it has been argued that scales can be individualized for each student to improve efficiency without sacrificing technical characteristics. The current study examines the dependability of 5 items comprising a DBR-MIS designed to measure classroom disruptive behavior. A series of generalizability theory and decision studies were conducted to examine the dependability of each item (calls out, noisy, clowns around, talks to classmates and out of seat), as well as a 3-item composite that was individualized for each student. Seven graduate students rated the behavior of 9 middle-school students on each item over 3 occasions. Ratings were based on 10-min video clips of students during mathematics instruction. Separate generalizability and decision studies were conducted for each item and for a 3-item composite that was individualized for each student based on the highest rated items on the first rating occasion. Findings indicate favorable dependability estimates for 3 of the 5 items and exceptional dependability estimates for the individualized composite. PMID:25730160

  20. Familial and Religious Influences on Adolescent Alcohol Use: A Multi-Level Study of Students and School Communities

    ERIC Educational Resources Information Center

    Bjarnason, Thoroddur; Thorlindsson, Thorolfur; Sigfusdottir, Inga D.; Welch, Michael R.

    2005-01-01

    A multi-level Durkheimian theory of familial and religious influences on adolescent alcohol use is developed and tested with hierarchical linear modeling of data from Icelandic schools and students. On the individual level, traditional family structure, parental monitoring, parental support, religious participation, and perceptions of divine

  1. Multi-Level Phase Change Memory Cells with SiN or Ta2O5 Barrier Layers

    NASA Astrophysics Data System (ADS)

    Gyanathan, Ashvini; Yeo, Yee-Chia

    2012-02-01

    This work compares the effects of SiN and Ta2O5 barrier layers in a multi-level phase change random access memory (PCRAM) cell. The PCRAM cell comprises a phase change material stack between a top and a bottom electrode. The phase change material stack comprises a nitrogen-doped Ge2Sb2Te5 (NGST) layer on top of a thin barrier layer on an undoped GST layer. The thermal conductivity and electrical resistivity of the barrier layer affect multi-level switching performance in terms of endurance as well as power consumption. Extensive electrical characterization was performed on these PCRAM multi-level devices. Thermal analysis was also performed to investigate the thermal efficiency of each barrier layer. It was observed that for a constant barrier layer thickness of 1.5 nm, the endurance of the multi-level device with the SiN barrier layer was better than that with the Ta2O5 barrier layer; however, the multi-level device with the Ta2O5 barrier layer had a lower power consumption than that with the SiN barrier layer.

  2. Separating regional and global sea level contributions with an inverse multi-sensor approach

    NASA Astrophysics Data System (ADS)

    Kusche, J.; Jensen, L.; Rietbroek, R.

    2012-12-01

    We quantify the effect of mass flux (ice sheets, glaciers, land water storage) and steric changes on long-term and seasonal regional and global sea level variability. We perform a joint inversion with GRACE time-variable gravity and Jason-1/2 altimetric data and compare our results with those obtained with other methods. In this way, we are able to explain 1,45 mm/a of the 1,93 mm/a total sea level rise observed for 8/2002-7/2009. An inverse method to separate the temporal evolution of about 100 'fingerprints' of glacier and ice-sheet melting, thermal expansion, changes in catchment water storage and glacial isostatic adjustment from spaceborne gravity and altimetry data has been developed. Our method takes into account the effects of self-gravitation, elastic loading of the ocean bottom, and the response of Earth rotation to mass redistribution. For comparison, we also calculate the contributions of the individual catchments to sea level change from GRACE directly using a standard basin averaging method. While we find considerable differences between methods for catchment mass flux, GRACE-only results are quite robust in terms of global and regional sea level change. However, it turns out that adding Jason altimetry does provide valuable information in an inverse multi-sensor approach. In terms of global sea level rise, our results indicate, for example, a steric contribution of 0,35 mm/a in the considered time frame. Regionally, however, the contribution of ice sheets, glaciers, land water and steric changes displays strong variations. We will show results including error estimates for various regions.

  3. Multi-level machine learning prediction of proteinprotein interactions in Saccharomyces cerevisiae

    PubMed Central

    Zubek, Julian; Tatjewski, Marcin; Boniecki, Adam; Mnich, Maciej; Basu, Subhadip

    2015-01-01

    Accurate identification of proteinprotein interactions (PPI) is the key step in understanding proteins biological functions, which are typically context-dependent. Many existing PPI predictors rely on aggregated features from protein sequences, however only a few methods exploit local information about specific residue contacts. In this work we present a two-stage machine learning approach for prediction of proteinprotein interactions. We start with the carefully filtered data on protein complexes available for Saccharomyces cerevisiae in the Protein Data Bank (PDB) database. First, we build linear descriptions of interacting and non-interacting sequence segment pairs based on their inter-residue distances. Secondly, we train machine learning classifiers to predict binary segment interactions for any two short sequence fragments. The final prediction of the proteinprotein interaction is done using the 2D matrix representation of all-against-all possible interacting sequence segments of both analysed proteins. The level-I predictor achieves 0.88 AUC for micro-scale, i.e., residue-level prediction. The level-II predictor improves the results further by a more complex learning paradigm. We perform 30-fold macro-scale, i.e., protein-level cross-validation experiment. The level-II predictor using PSIPRED-predicted secondary structure reaches 0.70 precision, 0.68 recall, and 0.70 AUC, whereas other popular methods provide results below 0.6 threshold (recall, precision, AUC). Our results demonstrate that multi-scale sequence features aggregation procedure is able to improve the machine learning results by more than 10% as compared to other sequence representations. Prepared datasets and source code for our experimental pipeline are freely available for download from: http://zubekj.github.io/mlppi/ (open source Python implementation, OS independent). PMID:26157620

  4. Multi-level machine learning prediction of protein-protein interactions in Saccharomyces cerevisiae.

    PubMed

    Zubek, Julian; Tatjewski, Marcin; Boniecki, Adam; Mnich, Maciej; Basu, Subhadip; Plewczynski, Dariusz

    2015-01-01

    Accurate identification of protein-protein interactions (PPI) is the key step in understanding proteins' biological functions, which are typically context-dependent. Many existing PPI predictors rely on aggregated features from protein sequences, however only a few methods exploit local information about specific residue contacts. In this work we present a two-stage machine learning approach for prediction of protein-protein interactions. We start with the carefully filtered data on protein complexes available for Saccharomyces cerevisiae in the Protein Data Bank (PDB) database. First, we build linear descriptions of interacting and non-interacting sequence segment pairs based on their inter-residue distances. Secondly, we train machine learning classifiers to predict binary segment interactions for any two short sequence fragments. The final prediction of the protein-protein interaction is done using the 2D matrix representation of all-against-all possible interacting sequence segments of both analysed proteins. The level-I predictor achieves 0.88 AUC for micro-scale, i.e., residue-level prediction. The level-II predictor improves the results further by a more complex learning paradigm. We perform 30-fold macro-scale, i.e., protein-level cross-validation experiment. The level-II predictor using PSIPRED-predicted secondary structure reaches 0.70 precision, 0.68 recall, and 0.70 AUC, whereas other popular methods provide results below 0.6 threshold (recall, precision, AUC). Our results demonstrate that multi-scale sequence features aggregation procedure is able to improve the machine learning results by more than 10% as compared to other sequence representations. Prepared datasets and source code for our experimental pipeline are freely available for download from: http://zubekj.github.io/mlppi/ (open source Python implementation, OS independent). PMID:26157620

  5. Structured Multi-level Data Fusion and Modelling of Heterogeneous Environmental Data for Future Internet Applications

    NASA Astrophysics Data System (ADS)

    Sabeur, Zoheir; Chakravarthy, Ajay; Bashevoy, Maxim; Modafferi, Stefano

    2013-04-01

    The rapid increase in environmental observations which are conducted by Small to Medium Enterprise communities and volunteers using affordable in situ sensors at various scales, in addition to the more established observatories set up by environmental and space agencies using airborne and space-borne sensing technologies is generating serious amounts of BIG data at ever increasing speeds. Furthermore, the emergence of Future Internet technologies and the urgent requirements for the deployment of specific enablers for the delivery of processed environmental knowledge in real-time with advanced situation awareness to citizens has reached paramount importance. Specifically, it has become highly critical now to build and provide services which automate the aggregation of data from various sources, while surmounting the semantic gaps, conflicts and heterogeneity in data sources. The early stage aggregation of data will enable the pre-processing of data from multiple sources while reconciling the temporal gaps in measurement time series, and aligning their respective a-synchronicities. This low level type of data fusion process needs to be automated and chained to more advanced level of data fusion services specialising in observation forecasts at spaces where sensing is not deployed; or at time slices where sensing has not taken place yet. As a result, multi-level fusion services are required among the families of specific enablers for monitoring environments and spaces in the Future Internet. These have been intially deployed and piloted in the ongoing ENVIROFI project of the FI-PPP programme [1]. Automated fusion and modelling of in situ and remote sensing data has been set up and the experimentation successfully conducted using RBF networks for the spatial fusion of water quality parameters measurements from satellite and stationary buoys in the Irish Sea. The RBF networks method scales for the spatial data fusion of multiple types of observation sources. This important approach provides a strong basis for the delivery of environmental observations at desired spatial and temporal scales to multiple users with various needs of spatial and temporal resolutions. It has also led to building robust future internet specific enablers on data fusion, which can indeed be used for multiple usage areas above and beyond the environmental domains of the Future Internet. In this paper, data and processing workflow scenarios shall be described. The fucntionalities of the multi-level fusion services shall be demonstrated and made accessible to the wider communities of the Fututre Internet. [1] The Environmental Observation Web and its Service Applications within the Future Internet. ENVIROFI IP. FP7-2011-ICT-IF Pr.No: 284898 http://www.envirofi.eu/

  6. On the utility of the multi-level algorithm for the solution of nearly completely decomposable Markov chains

    NASA Technical Reports Server (NTRS)

    Leutenegger, Scott T.; Horton, Graham

    1994-01-01

    Recently the Multi-Level algorithm was introduced as a general purpose solver for the solution of steady state Markov chains. In this paper, we consider the performance of the Multi-Level algorithm for solving Nearly Completely Decomposable (NCD) Markov chains, for which special-purpose iteractive aggregation/disaggregation algorithms such as the Koury-McAllister-Stewart (KMS) method have been developed that can exploit the decomposability of the the Markov chain. We present experimental results indicating that the general-purpose Multi-Level algorithm is competitive, and can be significantly faster than the special-purpose KMS algorithm when Gauss-Seidel and Gaussian Elimination are used for solving the individual blocks.

  7. iqr: a tool for the construction of multi-level simulations of brain and behaviour.

    PubMed

    Bernardet, Ulysses; Verschure, Paul F M J

    2010-06-01

    The brain is the most complex system we know of. Despite the wealth of data available in neuroscience, our understanding of this system is still very limited. Here we argue that an essential component in our arsenal of methods to advance our understanding of the brain is the construction of artificial brain-like systems. In this way we can encompass the multi-level organisation of the brain and its role in the context of the complete embodied real-world and real-time perceiving and behaving system. Hence, on the one hand, we must be able to develop and validate theories of brains as closing the loop between perception and action, and on the other hand as interacting with the real world. Evidence is growing that one of the sources of the computational power of neuronal systems lies in the massive and specific connectivity, rather than the complexity of single elements. To meet these challenges-multiple levels of organisation, sophisticated connectivity, and the interaction of neuronal models with the real-world-we have developed a multi-level neuronal simulation environment, iqr. This framework deals with these requirements by directly transforming them into the core elements of the simulation environment itself. iqr provides a means to design complex neuronal models graphically, and to visualise and analyse their properties on-line. In iqr connectivity is defined in a flexible, yet compact way, and simulations run at a high speed, which allows the control of real-world devices-robots in the broader sense-in real-time. The architecture of iqr is modular, providing the possibility to write new neuron, and synapse types, and custom interfaces to other hardware systems. The code of iqr is publicly accessible under the GNU General Public License (GPL). iqr has been in use since 1996 and has been the core tool for a large number of studies ranging from detailed models of neuronal systems like the cerebral cortex, and the cerebellum, to robot based models of perception, cognition and action to large-scale real-world systems. In addition, iqr has been widely used over many years to introduce students to neuronal simulation and neuromorphic control. In this paper we outline the conceptual and methodological background of iqr and its design philosophy. Thereafter we present iqr's main features and computational properties. Finally, we describe a number of projects using iqr, singling out how iqr is used for building a "synthetic insect". PMID:20502987

  8. Recent developments in wafer-level fabrication of micro-optical multi-aperture imaging systems

    NASA Astrophysics Data System (ADS)

    Leitel, R.; Dannberg, P.; Brckner, A.; Bruer, A.

    2011-10-01

    Micro-optical systems, that utilize multiple channels for imaging instead of a single one, are frequently discussed for ultra-compact applications such as digital cameras. The strategy of their fabrication differs due to different concepts of image formation. Illustrated by recently implemented systems for multi-aperture imaging, typical steps of wafer-level fabrication are discussed in detail. In turn, the made progress may allow for additional degrees of freedom in optical design. Pressing ahead with very short overall lengths and multiple diaphragm array layers, results in the use of extremely thin glass substrates down to 100 microns in thickness. The desire for a wide field of view for imaging has led to chirped arrays of microlenses and diaphragms. Focusing on imaging quality, aberrations were corrected by introducing toroidal lenslets and elliptical apertures. Such lenslets had been generated by thermal reflow of lithographic patterned photoresist and subsequent molding. Where useful, the system's performance can be further increased by applying aspheric microlenses from reactive ion etching (RIE) transfer or by achromatic doublets from superimposing two moldings with different polymers. Multiple diaphragm arrays prevent channel crosstalk. But using simple metal layers may lead to multiple reflections and an increased appearance of ghost images. A way out are low reflecting black matrix polymers that can be directly patterned by lithography. But in case of environmental stability and high resolution, organic coatings should be replaced by patterned metal coatings that exhibit matched antireflective layers like the prominent black chromium. The mentioned components give an insight into the fabrication process of multi-aperture imaging systems. Finally, the competence in each step decides on the overall image quality.

  9. Establishment of diagnostic reference levels for common multi-detector computed tomography examinations in Iran.

    PubMed

    Najafi, Mohsen; Deevband, Mohammad Reza; Ahmadi, Mohsen; Kardan, Mohammad Reza

    2015-12-01

    In order to establish diagnostic reference levels (DRLs) for multi-detector computed tomography (MDCT), four routine CT examinations were identified and a computer program was developed to collect data from 19 MDCT scanners in Iran. Mean values of Volume computed tomography dose index (CTDIvol) and dose-length product (DLP) in each site were calculated and the DRLs were defined as the 75th percentile of the distribution of the CTDIvol/DLP values for each examination. In terms of DLP, the DRLs of adult age group are 700, 290, 330, and 550mGycm for the Brain, Sinus, Chest, and Abdomen and Pelvis protocols, respectively. Although DRLs of this study are comparable to other international DRLs and in most cases are less than the international reference values, the great extent of dose distributions indicates that the CT imaging procedures in Iran should be optimized by applying diagnostic reference levels in order to decrease the radiation dose to patient undergoing CT examination. PMID:26507898

  10. Raetrad model extensions for radon entry into multi-level buildings with basements or crawl spaces.

    PubMed

    Nielson, K K; Rogers, V C; Rogers, V; Holt, R B

    1997-10-01

    The RAETRAD model was generalized to characterize radon generation and movement from soils and building materials into multi-level buildings with basements or crawl spaces. With the generalization, the model retains its original simplicity and ease of use. The model calculates radon entry rates that are consistent with measurements published for basement test structures at Colorado State University, confirming approximately equal contributions from diffusion and pressure-driven air flow at indoor-outdoor air pressure differences of deltaP(i-o) = -3.5 Pa. About one-fourth of the diffusive radon entry comes from concrete slabs and three-fourths comes from the surrounding soils. Calculated radon entry rates with and without a barrier over floor-wall shrinkage cracks generally agree with Colorado State University measurements when a sustained pressure of deltaP(i-o) = -2 Pa is used to represent calm wind (<1 m s(-1)) conditions. Calculated radon distributions in a 2-level house also are consistent with published measurements and equations. PMID:9314234

  11. A spectral-Lagrangian Boltzmann solver for a multi-energy level gas

    SciTech Connect

    Munaf, Alessandro; Haack, Jeffrey R.; Gamba, Irene M.; Magin, Thierry E.

    2014-05-01

    In this paper a spectral-Lagrangian method is proposed for the full, non-linear Boltzmann equation for a multi-energy level gas typical of a hypersonic re-entry flow. Internal energy levels are treated as separate species and inelastic collisions (leading to internal energy excitation and relaxation) are accounted for. The formulation developed can also be used for the case of a gas mixture made of monatomic gases without internal energy (where only elastic collisions occur). The advantage of the spectral-Lagrangian method lies in the generality of the algorithm in use for the evaluation of the elastic and inelastic collision operators, as well as the conservation of mass, momentum and energy during collisions. The latter is realized through the solution of constrained optimization problems. The computational procedure is based on the Fourier transform of the partial elastic and inelastic collision operators and exploits the fact that these can be written as weighted convolutions in Fourier space with no restriction on the cross-section model. The feasibility of the proposed approach is demonstrated through numerical examples for both space homogeneous and in-homogeneous problems. Computational results are compared with those obtained by means of the DSMC method in order to assess the accuracy of the proposed spectral-Lagrangian method.

  12. Interevent time distributions of human multi-level activity in a virtual world

    NASA Astrophysics Data System (ADS)

    Mryglod, O.; Fuchs, B.; Szell, M.; Holovatch, Yu.; Thurner, S.

    2015-02-01

    Studying human behavior in virtual environments provides extraordinary opportunities for a quantitative analysis of social phenomena with levels of accuracy that approach those of the natural sciences. In this paper we use records of player activities in the massive multiplayer online game Pardus over 1238 consecutive days, and analyze dynamical features of sequences of actions of players. We build on previous work where temporal structures of human actions of the same type were quantified, and provide an empirical understanding of human actions of different types. This study of multi-level human activity can be seen as a dynamic counterpart of static multiplex network analysis. We show that the interevent time distributions of actions in the Pardus universe follow highly non-trivial distribution functions, from which we extract action-type specific characteristic 'decay constants'. We discuss characteristic features of interevent time distributions, including periodic patterns on different time scales, bursty dynamics, and various functional forms on different time scales. We comment on gender differences of players in emotional actions, and find that while males and females act similarly when performing some positive actions, females are slightly faster for negative actions. We also observe effects on the age of players: more experienced players are generally faster in making decisions about engaging in and terminating enmity and friendship, respectively.

  13. Large scale gene regulatory network inference with a multi-level strategy.

    PubMed

    Wu, Jun; Zhao, Xiaodong; Lin, Zongli; Shao, Zhifeng

    2016-01-26

    Transcriptional regulation is a basis of many crucial molecular processes and an accurate inference of the gene regulatory network is a helpful and essential task to understand cell functions and gain insights into biological processes of interest in systems biology. Inspired by the Dialogue for Reverse Engineering Assessments and Methods (DREAM) projects, many excellent gene regulatory network inference algorithms have been proposed. However, it is still a challenging problem to infer a gene regulatory network from gene expression data on a large scale. In this paper, we propose a gene regulatory network inference method based on a multi-level strategy (GENIMS), which can give results that are more accurate and robust than the state-of-the-art methods. The proposed method mainly consists of three levels, which are an original feature selection step based on guided regularized random forest, normalization of individual feature selection and the final refinement step according to the topological property of the gene regulatory network. To prove the accuracy and robustness of our method, we compare our method with the state-of-the-art methods on the DREAM4 and DREAM5 benchmark networks and the results indicate that the proposed method can significantly improve the performance of gene regulatory network inference. Additionally, we also discuss the influence of the selection of different parameters in our method. PMID:26687446

  14. Image accuracy and representational enhancement through low-level, multi-sensor integration techniques

    SciTech Connect

    Baker, J.E.

    1994-09-01

    Multi-Sensor Integration (MSI) is the combining of data and information from more than one source in order to generate a more reliable and consistent representation of the environment. The need for MSI derives largely from basic ambiguities inherent in our current sensor imaging technologies. These ambiguities exist as long as the mapping from reality to image is not 1-to-1. That is, if different {open_quotes}realities{close_quotes} lead to identical images, a single image cannot reveal the particular reality which was the truth. MSI techniques attempt to resolve some of these ambiguities by appropriately coupling complementary images to eliminate possible inverse mappings. What constitutes the best MSI technique is dependent on the given application domain, available sensors, and task requirements. MSI techniques can be divided into three categories based on the relative information content of the original images with that of the desired representation: (1) {open_quotes}detail enhancement,{close_quotes} wherein the relative information content of the original images is less rich than the desired representation; (2) {open_quotes}data enhancement,{close_quotes} wherein the MSI techniques are concerned with improving the accuracy of the data rather than either increasing or decreasing the level of detail; and (3) {open_quotes}conceptual enhancement,{close_quotes} wherein the image contains more detail than is desired, making it difficult to easily recognize objects of interest. In conceptual enhancement one must group pixels corresponding to the same conceptual object and thereby reduce the level of extraneous detail.

  15. Multi-level tolerance opinion dynamics in military command and control networks

    NASA Astrophysics Data System (ADS)

    Song, Xiao; Shi, Wen; Tan, Gary; Ma, Yaofei

    2015-11-01

    Opinion exchange is useful when a military agent needs to take the opinions of others into account before decision making. Few studies have addressed opinion dynamics in military command and control (C2) organizations, which are often hierarchically ranked in a tree structure. Moreover, military agents should have different tolerance levels when communicating with differentially ranked agents, which is our reasoning for proposing an opinion dynamics model with multi-level tolerance in this study. We can use this model to test opinion dynamics models in depth and further analyze and compare them to traditional tree organizations and other organization forms, including small-world and scale-free networks. Opinion dynamics experiments show that although traditional indices such as a clustering coefficient or the average distance of a small-world network are worse than those of a scale-free network, opinion dynamics indices, which include the number of rounds to fixed opinions, number of opinion clusters, and relative size of the largest small-world cluster are unexpectedly better than those of a scale-free network. Moreover, adding links to a tree network can enhance the tendency to consensus, while a small-world network needs fewer links compared to a scale-free network.

  16. Modeling fuzzy multi-period production planning and sourcing problem with credibility service levels

    NASA Astrophysics Data System (ADS)

    Lan, Yan-Fei; Liu, Yan-Kui; Sun, Gao-Ji

    2009-09-01

    A great deal of research has been done on production planning and sourcing problems, most of which concern deterministic or stochastic demand and cost situations and single period systems. In this paper, we consider a new class of multi-period production planning and sourcing problem with credibility service levels, in which a manufacturer has a number of plants and subcontractors and has to meet the product demand according to the credibility service levels set by its customers. In the proposed problem, demands and costs are uncertain and assumed to be fuzzy variables with known possibility distributions. The objective of the problem is to minimize the total expected cost, including the expected value of the sum of the inventory holding and production cost in the planning horizon. Because the proposed problem is too complex to apply conventional optimization algorithms, we suggest an approximation approach (AA) to evaluate the objective function. After that, two algorithms are designed to solve the proposed production planning problem. The first is a PSO algorithm combining the AA, and the second is a hybrid PSO algorithm integrating the AA, neural network (NN) and PSO. Finally, one numerical example is provided to compare the effectiveness of the proposed two algorithms.

  17. Multi-Level Building Reconstruction for Automatic Enhancement of High Resolution Dsms

    NASA Astrophysics Data System (ADS)

    Arefi, H.; Reinartz, P.

    2012-07-01

    In this article a multi-level approach is proposed for reconstruction-based improvement of high resolution Digital Surface Models (DSMs). The concept of Levels of Detail (LOD) defined by CityGML standard has been considered as basis for abstraction levels of building roof structures. Here, the LOD1 and LOD2 which are related to prismatic and parametric roof shapes are reconstructed. Besides proposing a new approach for automatic LOD1 and LOD2 generation from high resolution DSMs, the algorithm contains two generalization levels namely horizontal and vertical. Both generalization levels are applied to prismatic model of buildings. The horizontal generalization allows controlling the approximation level of building footprints which is similar to cartographic generalization concept of the urban maps. In vertical generalization, the prismatic model is formed using an individual building height and continuous to included all flat structures locating in different height levels. The concept of LOD1 generation is based on approximation of the building footprints into rectangular or non-rectangular polygons. For a rectangular building containing one main orientation a method based on Minimum Bounding Rectangle (MBR) in employed. In contrast, a Combined Minimum Bounding Rectangle (CMBR) approach is proposed for regularization of non-rectilinear polygons, i.e. buildings without perpendicular edge directions. Both MBRand CMBR-based approaches are iteratively employed on building segments to reduce the original building footprints to a minimum number of nodes with maximum similarity to original shapes. A model driven approach based on the analysis of the 3D points of DSMs in a 2D projection plane is proposed for LOD2 generation. Accordingly, a building block is divided into smaller parts according to the direction and number of existing ridge lines. The 3D model is derived for each building part and finally, a complete parametric model is formed by merging all the 3D models of the individual parts and adjusting the nodes after the merging step. In order to provide an enhanced DSM, a surface model is provided for each building by interpolation of the internal points of the generated models. All interpolated models are situated on a Digital Terrain Model (DTM) of corresponding area to shape the enhanced DSM. Proposed DSM enhancement approach has been tested on a dataset from Munich central area. The original DSM is created using robust stereo matching of Worldview-2 stereo images. A quantitative assessment of the new DSM by comparing the heights of the ridges and eaves shows a standard deviation of better than 50cm.

  18. Carrier Density and Compensation in Semiconductors with Multi Dopants and Multi Transition Energy Levels: The Case of Cu Impurity in CdTe: Preprint

    SciTech Connect

    Wei, S. H.; Ma, J.; Gessert, T. A.; Chin, K. K.

    2011-07-01

    Doping is one of the most important issues in semiconductor physics. The charge carrier generated by doping can profoundly change the properties of semiconductors and their performance in optoelectronic device applications, such as solar cells. Using detailed balance theory and first-principles calculated defect formation energies and transition energy levels, we derive general formulae to calculate carrier density for semiconductors with multi dopants and multi transition energy levels. As an example, we studied CdTe doped with Cu, in which VCd, CuCd, and Cui are the dominant defects/impurities. We show that in this system, when Cu concentration increases, the doping properties of the system can change from a poor p-type, to a poorer p-type, to a better p-type, and then to a poor p-type again, in good agreement with experimental observation of CdTe-based solar cells.

  19. Dispersion retrieval from multi-level ultra-deep reactive-ion-etched microstructures for terahertz slow-wave circuits

    SciTech Connect

    Baik, Chan-Wook Young Ahn, Ho; Kim, Yongsung; Lee, Jooho; Hong, Seogwoo; Hee Choi, Jun; Kim, Sunil; Hun Lee, Sang; Min Kim, Jong; Hwang, Sungwoo; Yeon Jun, So; Yu, SeGi; Lawrence Ives, R.

    2014-01-13

    A multi-level microstructure is proposed for terahertz slow-wave circuits, with dispersion relation retrieved by scattering parameter measurements. The measured return loss shows strong resonances above the cutoff with negligible phase shifts compared with finite element analysis. Splitting the circuit into multi levels enables a low aspect ratio configuration that alleviates the loading effect of deep-reactive-ion etching on silicon wafers. This makes it easier to achieve flat-etched bottom and smooth sidewall profiles. The dispersion retrieved from the measurement, therefore, corresponds well to the theoretical estimation. The result provides a straightforward way to the precise determination of dispersions in terahertz vacuum electronics.

  20. Multi-Level Experimental and Analytical Evaluation of Two Composite Energy Absorbers

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Littell, Justin D.; Fasanella, Edwin L.; Annett, Martin S.; Seal, Michael D., II

    2015-01-01

    Two composite energy absorbers were developed and evaluated at NASA Langley Research Center through multi-level testing and simulation performed under the Transport Rotorcraft Airframe Crash Testbed (TRACT) research program. A conical-shaped energy absorber, designated the conusoid, was evaluated that consisted of four layers of hybrid carbon-Kevlar plain weave fabric oriented at [+45 deg/-45 deg/-45 deg/+45 deg] with respect to the vertical, or crush, direction. A sinusoidal-shaped energy absorber, designated the sinusoid, was developed that consisted of hybrid carbon-Kevlar plain weave fabric face sheets, two layers for each face sheet oriented at +/-45deg with respect to the vertical direction and a closed-cell ELFOAM P200 polyisocyanurate (2.0-lb/cu ft) foam core. The design goal for the energy absorbers was to achieve average floor-level accelerations of between 25- and 40-g during the full-scale crash test of a retrofitted CH-46E helicopter airframe, designated TRACT 2. Variations in both designs were assessed through dynamic crush testing of component specimens. Once the designs were finalized, subfloor beams of each configuration were fabricated and retrofitted into a barrel section of a CH-46E helicopter. A vertical drop test of the barrel section was conducted onto concrete to evaluate the performance of the energy absorbers prior to retrofit into TRACT 2. The retrofitted airframe was crash tested under combined forward and vertical velocity conditions onto soil, which is characterized as a sand/clay mixture. Finite element models were developed of all test articles and simulations were performed using LS-DYNA, a commercial nonlinear explicit transient dynamic finite element code. Test-analysis results are presented for each energy absorber as comparisons of time-history responses, as well as predicted and experimental structural deformations and progressive damage under impact loading for each evaluation level.

  1. Image accuracy and representational enhancement through low-level, multi-sensor integration techniques

    SciTech Connect

    Baker, J.E.

    1993-05-01

    Multi-Sensor Integration (MSI) is the combining of data and information from more than one source in order to generate a more reliable and consistent representation of the environment. The need for MSI derives largely from basic ambiguities inherent in our current sensor imaging technologies. These ambiguities exist as long as the mapping from reality to image is not 1-to-1. That is, if different 44 realities`` lead to identical images, a single image cannot reveal the particular reality which was the truth. MSI techniques can be divided into three categories based on the relative information content of the original images with that of the desired representation: (1) ``detail enhancement,`` wherein the relative information content of the original images is less rich than the desired representation; (2) ``data enhancement,`` wherein the MSI techniques axe concerned with improving the accuracy of the data rather than either increasing or decreasing the level of detail; and (3) ``conceptual enhancement,`` wherein the image contains more detail than is desired, making it difficult to easily recognize objects of interest. In conceptual enhancement one must group pixels corresponding to the same conceptual object and thereby reduce the level of extraneous detail. This research focuses on data and conceptual enhancement algorithms. To be useful in many real-world applications, e.g., autonomous or teleoperated robotics, real-time feedback is critical. But, many MSI/image processing algorithms require significant processing time. This is especially true of feature extraction, object isolation, and object recognition algorithms due to their typical reliance on global or large neighborhood information. This research attempts to exploit the speed currently available in state-of-the-art digitizers and highly parallel processing systems by developing MSI algorithms based on pixel rather than global-level features.

  2. Image accuracy and representational enhancement through low-level, multi-sensor integration techniques

    SciTech Connect

    Baker, J.E.

    1993-05-01

    Multi-Sensor Integration (MSI) is the combining of data and information from more than one source in order to generate a more reliable and consistent representation of the environment. The need for MSI derives largely from basic ambiguities inherent in our current sensor imaging technologies. These ambiguities exist as long as the mapping from reality to image is not 1-to-1. That is, if different 44 realities'' lead to identical images, a single image cannot reveal the particular reality which was the truth. MSI techniques can be divided into three categories based on the relative information content of the original images with that of the desired representation: (1) detail enhancement,'' wherein the relative information content of the original images is less rich than the desired representation; (2) data enhancement,'' wherein the MSI techniques axe concerned with improving the accuracy of the data rather than either increasing or decreasing the level of detail; and (3) conceptual enhancement,'' wherein the image contains more detail than is desired, making it difficult to easily recognize objects of interest. In conceptual enhancement one must group pixels corresponding to the same conceptual object and thereby reduce the level of extraneous detail. This research focuses on data and conceptual enhancement algorithms. To be useful in many real-world applications, e.g., autonomous or teleoperated robotics, real-time feedback is critical. But, many MSI/image processing algorithms require significant processing time. This is especially true of feature extraction, object isolation, and object recognition algorithms due to their typical reliance on global or large neighborhood information. This research attempts to exploit the speed currently available in state-of-the-art digitizers and highly parallel processing systems by developing MSI algorithms based on pixel rather than global-level features.

  3. Sensitive Multi-Species Emissions Monitoring: Infrared Laser-Based Detection of Trace-Level Contaminants.

    SciTech Connect

    Steill, Jeffrey D

    2015-01-01

    This report summarizes our development of spectroscopic chemical analysis techniques and spectral modeling for trace-gas measurements of highly-regulated low-concentration species present in flue gas emissions from utility coal boilers such as HCl under conditions of high humidity. Detailed spectral modeling of the spectroscopy of HCl and other important combustion and atmospheric species such as H 2 O, CO 2 , N 2 O, NO 2 , SO 2 , and CH 4 demonstrates that IR-laser spectroscopy is a sensitive multi-component analysis strategy. Experimental measurements from techniques based on IR laser spectroscopy are presented that demonstrate sub-ppm sensitivity levels to these species. Photoacoustic infrared spectroscopy is used to detect and quantify HCl at ppm levels with extremely high signal-to-noise even under conditions of high relative humidity. Additionally, cavity ring-down IR spectroscopy is used to achieve an extremely high sensitivity to combustion trace gases in this spectral region; ppm level CH 4 is one demonstrated example. The importance of spectral resolution in the sensitivity of a trace-gas measurement is examined by spectral modeling in the mid- and near-IR, and efforts to improve measurement resolution through novel instrument development are described. While previous project reports focused on benefits and complexities of the dual-etalon cavity ring-down infrared spectrometer, here details on steps taken to implement this unique and potentially revolutionary instrument are described. This report also illustrates and critiques the general strategy of IR- laser photodetection of trace gases leading to the conclusion that mid-IR laser spectroscopy techniques provide a promising basis for further instrument development and implementation that will enable cost-effective sensitive detection of multiple key contaminant species simultaneously.

  4. Bi-level multi-source learning for heterogeneous block-wise missing data.

    PubMed

    Xiang, Shuo; Yuan, Lei; Fan, Wei; Wang, Yalin; Thompson, Paul M; Ye, Jieping

    2014-11-15

    Bio-imaging technologies allow scientists to collect large amounts of high-dimensional data from multiple heterogeneous sources for many biomedical applications. In the study of Alzheimer's Disease (AD), neuroimaging data, gene/protein expression data, etc., are often analyzed together to improve predictive power. Joint learning from multiple complementary data sources is advantageous, but feature-pruning and data source selection are critical to learn interpretable models from high-dimensional data. Often, the data collected has block-wise missing entries. In the Alzheimer's Disease Neuroimaging Initiative (ADNI), most subjects have MRI and genetic information, but only half have cerebrospinal fluid (CSF) measures, a different half has FDG-PET; only some have proteomic data. Here we propose how to effectively integrate information from multiple heterogeneous data sources when data is block-wise missing. We present a unified "bi-level" learning model for complete multi-source data, and extend it to incomplete data. Our major contributions are: (1) our proposed models unify feature-level and source-level analysis, including several existing feature learning approaches as special cases; (2) the model for incomplete data avoids imputing missing data and offers superior performance; it generalizes to other applications with block-wise missing data sources; (3) we present efficient optimization algorithms for modeling complete and incomplete data. We comprehensively evaluate the proposed models including all ADNI subjects with at least one of four data types at baseline: MRI, FDG-PET, CSF and proteomics. Our proposed models compare favorably with existing approaches. PMID:23988272

  5. Multi-level tree analysis of pulmonary artery/vein trees in non-contrast CT images

    NASA Astrophysics Data System (ADS)

    Gao, Zhiyun; Grout, Randall W.; Hoffman, Eric A.; Saha, Punam K.

    2012-02-01

    Diseases like pulmonary embolism and pulmonary hypertension are associated with vascular dystrophy. Identifying such pulmonary artery/vein (A/V) tree dystrophy in terms of quantitative measures via CT imaging significantly facilitates early detection of disease or a treatment monitoring process. A tree structure, consisting of nodes and connected arcs, linked to the volumetric representation allows multi-level geometric and volumetric analysis of A/V trees. Here, a new theory and method is presented to generate multi-level A/V tree representation of volumetric data and to compute quantitative measures of A/V tree geometry and topology at various tree hierarchies. The new method is primarily designed on arc skeleton computation followed by a tree construction based topologic and geometric analysis of the skeleton. The method starts with a volumetric A/V representation as input and generates its topologic and multi-level volumetric tree representations long with different multi-level morphometric measures. A new recursive merging and pruning algorithms are introduced to detect bad junctions and noisy branches often associated with digital geometric and topologic analysis. Also, a new notion of shortest axial path is introduced to improve the skeletal arc joining two junctions. The accuracy of the multi-level tree analysis algorithm has been evaluated using computer generated phantoms and pulmonary CT images of a pig vessel cast phantom while the reproducibility of method is evaluated using multi-user A/V separation of in vivo contrast-enhanced CT images of a pig lung at different respiratory volumes.

  6. Microgrid and Inverter Control and Simulator Software

    SciTech Connect

    2012-09-13

    A collection of software that can simulate the operation of an inverter on a microgrid or control a real inverter. In addition, it can simulate the control of multiple nodes on a microgrid." Application: Simulation of inverters and microgrids; control of inverters on microgrids." The MMI submodule is designed to control custom inverter hardware, and to simulate that hardware. The INVERTER submodule is only the simulator code, and is of an earlier generation than the simulator in MMI. The MICROGRID submodule is an agent-based simulator of multiple nodes on a microgrid which presents a web interface. The WIND submodule produces movies of wind data with a web interface.

  7. Inverter design for high frequency power distribution

    NASA Technical Reports Server (NTRS)

    King, R. J.

    1985-01-01

    A class of simple resonantly commutated inverters are investigated for use in a high power (100 KW - 1000 KW) high frequency (10 KHz - 20 KHz) AC power distribution system. The Mapham inverter is found to provide a unique combination of large thyristor turn-off angle and good utilization factor, much better than an alternate 'current-fed' inverter. The effects of loading the Mapham inverter entirely with rectifier loads are investigated by simulation and with an experimental 3 KW 20 KHz inverter. This inverter is found to be well suited to a power system with heavy rectifier loading.

  8. Social and socio-demographic neighborhood effects on adolescent alcohol use: a systematic review of multi-level studies.

    PubMed

    Jackson, Nicki; Denny, Simon; Ameratunga, Shanthi

    2014-08-01

    There is growing interest in the role of the neighborhood environment on adolescent alcohol use. Multi-level designs are ideally suited to this investigation due to their ability to examine area-level effects over and above the effects due to neighborhood composition. To date, most research in this area has focused on the physical availability of alcohol in the neighborhood. We reviewed the multi-level evidence on neighborhood-level risk and protective factors which influence adolescent alcohol use, excluding studies which assessed the impact of neighborhood-level alcohol availability and advertising. Systematic searches in Medline, EMBASE, CINAHL Plus, PsycINFO, Sociological Abstracts and SCOPUS identified 23 studies, examining 11 different neighborhood-level exposures. The majority of studies found no associations with residential mobility, neighborhood disorder or crime, employment or job availability, neighborhood attitudes to drinking, social capital and collective efficacy. For studies examining neighborhood-level socio-economic disadvantage mixed results were found. High levels of both adult and adolescent alcohol use in the community appeared to be associated with alcohol use whilst protective effects were found for enforcement of liquor laws. Methodological limitations within studies were evident. The dearth of high-quality, multi-level studies indicate that further research is required to inform the development of multi-faceted place-based policy and preventative interventions to reduce adolescent alcohol use. Future studies should consider the neighborhood context from the outset of study design and identify the individual-level control variables to adequately isolate neighborhood effects. Inclusion of moderation and mediation analyses would greatly contribute towards the understanding of causal pathways of neighborhood effects. PMID:24937324

  9. Century to multi-century sea level rise projections from CMIP5 models

    NASA Astrophysics Data System (ADS)

    Yin, Jianjun

    2012-09-01

    Long-term projections of global-ocean thermal expansion (GTE) and the dynamic sea level (DSL) change are analyzed with 34 new CMIP5 models and under three greenhouse-gas emission scenarios. Multi-model ensemble mean (MEM) and ensemble standard deviation are calculated to identify robust features and quantify uncertainty. While the MEM of GTE shows moderate difference by 2100, with magnitudes of 13, 18 and 28 cm in RCP2.6, RCP4.5 and RCP8.5, respectively, it increases and diverges significantly by 2300, with magnitudes of 21, 52 and 119 cm in the three scenarios. Model-to-model spread seems reduced in CMIP5 compared to CMIP3. The MEM changes of the DSL show similar patterns between different RCPs, but with progressively larger magnitudes in RCP2.6, RCP4.5 and RCP8.5. Notable features identified previously in the CMIP3 projections also occur in CMIP5, indicating their robustness across generations of climate model and emission scenario. The CMIP5 models still show disagreement in projecting the DSL changes, even under the same external forcing.

  10. CMT: A Constrained Multi-Level Thresholding Approach for ChIP-Seq Data Analysis

    PubMed Central

    Rezaeian, Iman; Rueda, Luis

    2014-01-01

    Genome-wide profiling of DNA-binding proteins using ChIP-Seq has emerged as an alternative to ChIP-chip methods. ChIP-Seq technology offers many advantages over ChIP-chip arrays, including but not limited to less noise, higher resolution, and more coverage. Several algorithms have been developed to take advantage of these abilities and find enriched regions by analyzing ChIP-Seq data. However, the complexity of analyzing various patterns of ChIP-Seq signals still needs the development of new algorithms. Most current algorithms use various heuristics to detect regions accurately. However, despite how many formulations are available, it is still difficult to accurately determine individual peaks corresponding to each binding event. We developed Constrained Multi-level Thresholding (CMT), an algorithm used to detect enriched regions on ChIP-Seq data. CMT employs a constraint-based module that can target regions within a specific range. We show that CMT has higher accuracy in detecting enriched regions (peaks) by objectively assessing its performance relative to other previously proposed peak finders. This is shown by testing three algorithms on the well-known FoxA1 Data set, four transcription factors (with a total of six antibodies) for Drosophila melanogaster and the H3K4ac antibody dataset. PMID:24736605

  11. Aircraft Fault Detection and Classification Using Multi-Level Immune Learning Detection

    NASA Technical Reports Server (NTRS)

    Wong, Derek; Poll, Scott; KrishnaKumar, Kalmanje

    2005-01-01

    This work is an extension of a recently developed software tool called MILD (Multi-level Immune Learning Detection), which implements a negative selection algorithm for anomaly and fault detection that is inspired by the human immune system. The immunity-based approach can detect a broad spectrum of known and unforeseen faults. We extend MILD by applying a neural network classifier to identify the pattern of fault detectors that are activated during fault detection. Consequently, MILD now performs fault detection and identification of the system under investigation. This paper describes the application of MILD to detect and classify faults of a generic transport aircraft augmented with an intelligent flight controller. The intelligent control architecture is designed to accommodate faults without the need to explicitly identify them. Adding knowledge about the existence and type of a fault will improve the handling qualities of a degraded aircraft and impact tactical and strategic maneuvering decisions. In addition, providing fault information to the pilot is important for maintaining situational awareness so that he can avoid performing an action that might lead to unexpected behavior - e.g., an action that exceeds the remaining control authority of the damaged aircraft. We discuss the detection and classification results of simulated failures of the aircraft's control system and show that MILD is effective at determining the problem with low false alarm and misclassification rates.

  12. Synergistic High Charge-Storage Capacity for Multi-level Flexible Organic Flash Memory

    PubMed Central

    Kang, Minji; Khim, Dongyoon; Park, Won-Tae; Kim, Jihong; Kim, Juhwan; Noh, Yong-Young; Baeg, Kang-Jun; Kim, Dong-Yu

    2015-01-01

    Electret and organic floating-gate memories are next-generation flash storage mediums for printed organic complementary circuits. While each flash memory can be easily fabricated using solution processes on flexible plastic substrates, promising their potential for on-chip memory organization is limited by unreliable bit operation and high write loads. We here report that new architecture could improve the overall performance of organic memory, and especially meet high storage for multi-level operation. Our concept depends on synergistic effect of electrical characterization in combination with a polymer electret (poly(2-vinyl naphthalene) (PVN)) and metal nanoparticles (Copper). It is distinguished from mostly organic nano-floating-gate memories by using the electret dielectric instead of general tunneling dielectric for additional charge storage. The uniform stacking of organic layers including various dielectrics and poly(3-hexylthiophene) (P3HT) as an organic semiconductor, followed by thin-film coating using orthogonal solvents, greatly improve device precision despite easy and fast manufacture. Poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] as high-k blocking dielectric also allows reduction of programming voltage. The reported synergistic organic memory devices represent low power consumption, high cycle endurance, high thermal stability and suitable retention time, compared to electret and organic nano-floating-gate memory devices. PMID:26201747

  13. Synergistic High Charge-Storage Capacity for Multi-level Flexible Organic Flash Memory

    NASA Astrophysics Data System (ADS)

    Kang, Minji; Khim, Dongyoon; Park, Won-Tae; Kim, Jihong; Kim, Juhwan; Noh, Yong-Young; Baeg, Kang-Jun; Kim, Dong-Yu

    2015-07-01

    Electret and organic floating-gate memories are next-generation flash storage mediums for printed organic complementary circuits. While each flash memory can be easily fabricated using solution processes on flexible plastic substrates, promising their potential for on-chip memory organization is limited by unreliable bit operation and high write loads. We here report that new architecture could improve the overall performance of organic memory, and especially meet high storage for multi-level operation. Our concept depends on synergistic effect of electrical characterization in combination with a polymer electret (poly(2-vinyl naphthalene) (PVN)) and metal nanoparticles (Copper). It is distinguished from mostly organic nano-floating-gate memories by using the electret dielectric instead of general tunneling dielectric for additional charge storage. The uniform stacking of organic layers including various dielectrics and poly(3-hexylthiophene) (P3HT) as an organic semiconductor, followed by thin-film coating using orthogonal solvents, greatly improve device precision despite easy and fast manufacture. Poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] as high-k blocking dielectric also allows reduction of programming voltage. The reported synergistic organic memory devices represent low power consumption, high cycle endurance, high thermal stability and suitable retention time, compared to electret and organic nano-floating-gate memory devices.

  14. Networking health: multi-level marketing of health products in Ghana.

    PubMed

    Droney, Damien

    2016-04-01

    Multi-level marketing (MLM0), a business model in which product distributors are compensated for enrolling further distributors as well as for selling products, has experienced dramatic growth in recent decades, especially in the so-called global South. This paper argues that the global success of MLM is due to its involvement in local health markets. While MLM has been subject to a number of critiques, few have analyzed the explicit health claims of MLM distributors. The majority of the products distributed through MLM are health products, which are presented as offering transformative health benefits. Based on interviews with MLM distributors in Ghana, but focusing on the experiences of one woman, this paper shows that MLM companies become intimately entwined with Ghanaian quests for health by providing their distributors with the materials to become informal health experts, allowing their distributors to present their products as medicines, and presenting MLM as an avenue to middle class cosmopolitanism. Ghanaian distributors promote MLM products as medically powerful, and the distribution of these products as an avenue to status and profit. As a result, individuals seeking health become a part of ethically questionable forms of medical provision based on the exploitation of personal relationships. The success of MLM therefore suggests that the health industry is at the forefront of transnational corporations' extraction of value from informal economies, drawing on features of health markets to monetize personal relationships. PMID:26130429

  15. Opportunities in multi dimensional trace metal imaging: Taking copper associated disease research to the next level

    PubMed Central

    Vogt, Stefan; Ralle, Martina

    2012-01-01

    Copper plays an important role in numerous biological processes across all living systems predominantly because of its versatile redox behavior. Cellular copper homeostasis is tightly regulated and disturbances lead to severe disorders such as Wilson disease (WD) and Menkes disease. Age related changes of copper metabolism have been implicated in other neurodegenerative disorders such as Alzheimer’s disease (AD). The role of copper in these diseases has been topic of mostly bioinorganic research efforts for more than a decade, metal-protein interactions have been characterized and cellular copper pathways have been described. Despite these efforts, crucial aspects of how copper is associated with AD, for example, is still only poorly understood. To take metal related disease research to the next level, emerging multi dimensional imaging techniques are now revealing the copper metallome as the basis to better understand disease mechanisms. This review will describe how recent advances in X-ray fluorescence microscopy and fluorescent copper probes have started to contribute to this field specifically WD and AD. It furthermore provides an overview of current developments and future applications in X-ray microscopic methodologies. PMID:23079951

  16. Density-matrix renormalization group algorithm with multi-level active space.

    PubMed

    Ma, Yingjin; Wen, Jing; Ma, Haibo

    2015-07-21

    The density-matrix renormalization group (DMRG) method, which can deal with a large active space composed of tens of orbitals, is nowadays widely used as an efficient addition to traditional complete active space (CAS)-based approaches. In this paper, we present the DMRG algorithm with a multi-level (ML) control of the active space based on chemical intuition-based hierarchical orbital ordering, which is called as ML-DMRG with its self-consistent field (SCF) variant ML-DMRG-SCF. Ground and excited state calculations of H2O, N2, indole, and Cr2 with comparisons to DMRG references using fixed number of kept states (M) illustrate that ML-type DMRG calculations can obtain noticeable efficiency gains. It is also shown that the orbital re-ordering based on hierarchical multiple active subspaces may be beneficial for reducing computational time for not only ML-DMRG calculations but also DMRG ones with fixed M values. PMID:26203012

  17. Hybrid PV/diesel solar power system design using multi-level factor analysis optimization

    NASA Astrophysics Data System (ADS)

    Drake, Joshua P.

    Solar power systems represent a large area of interest across a spectrum of organizations at a global level. It was determined that a clear understanding of current state of the art software and design methods, as well as optimization methods, could be used to improve the design methodology. Solar power design literature was researched for an in depth understanding of solar power system design methods and algorithms. Multiple software packages for the design and optimization of solar power systems were analyzed for a critical understanding of their design workflow. In addition, several methods of optimization were studied, including brute force, Pareto analysis, Monte Carlo, linear and nonlinear programming, and multi-way factor analysis. Factor analysis was selected as the most efficient optimization method for engineering design as it applied to solar power system design. The solar power design algorithms, software work flow analysis, and factor analysis optimization were combined to develop a solar power system design optimization software package called FireDrake. This software was used for the design of multiple solar power systems in conjunction with an energy audit case study performed in seven Tibetan refugee camps located in Mainpat, India. A report of solar system designs for the camps, as well as a proposed schedule for future installations was generated. It was determined that there were several improvements that could be made to the state of the art in modern solar power system design, though the complexity of current applications is significant.

  18. Design of multi-level thick seam extractions under major aquifiers and considering spontaneous combustion risk

    SciTech Connect

    Reddish, D.J.; Dunham, R.K.

    1996-12-01

    The paper presents an approach to design a multi level room and pillar layout in a 40m thick seam overlain by a major aquifer. The design was required to maximize extraction with due consideration of the general stability of the workings, the potential water hazards, and spontaneous combustion risks due to air leakage between horizons. The approach utilized was a combination of empirical pillar sizing for water hazard control with numerical modelling to assess potential interactions between horizons. The numerical modelling allowed the size of interleaves, and the appropriate staggers to be optimized in terms of stress distribution. The stress distribution allows both the general stability of the openings and more importantly the permeability changes around the openings to be determined. The permeability of coal is sensitive to stress, and an empirical stress to permeability relationship, and theoretical permeability to flow leakage relationship has been applied to interpreting the relative spontaneous combustion risk associated with each of the proposed layouts. The final proposed design is a compromise between maximum exploitation of reserves and consideration of water hazards and of spontaneous combustion risk. Further more detailed design will be required as more comprehensive data on the geotechnical properties of the coal and overburden become available.

  19. Synergistic High Charge-Storage Capacity for Multi-level Flexible Organic Flash Memory.

    PubMed

    Kang, Minji; Khim, Dongyoon; Park, Won-Tae; Kim, Jihong; Kim, Juhwan; Noh, Yong-Young; Baeg, Kang-Jun; Kim, Dong-Yu

    2015-01-01

    Electret and organic floating-gate memories are next-generation flash storage mediums for printed organic complementary circuits. While each flash memory can be easily fabricated using solution processes on flexible plastic substrates, promising their potential for on-chip memory organization is limited by unreliable bit operation and high write loads. We here report that new architecture could improve the overall performance of organic memory, and especially meet high storage for multi-level operation. Our concept depends on synergistic effect of electrical characterization in combination with a polymer electret (poly(2-vinyl naphthalene) (PVN)) and metal nanoparticles (Copper). It is distinguished from mostly organic nano-floating-gate memories by using the electret dielectric instead of general tunneling dielectric for additional charge storage. The uniform stacking of organic layers including various dielectrics and poly(3-hexylthiophene) (P3HT) as an organic semiconductor, followed by thin-film coating using orthogonal solvents, greatly improve device precision despite easy and fast manufacture. Poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] as high-k blocking dielectric also allows reduction of programming voltage. The reported synergistic organic memory devices represent low power consumption, high cycle endurance, high thermal stability and suitable retention time, compared to electret and organic nano-floating-gate memory devices. PMID:26201747

  20. Advanced Modular Inverter Technology Development

    SciTech Connect

    Adam Szczepanek

    2006-02-04

    Electric and hybrid-electric vehicle systems require an inverter to convert the direct current (DC) output of the energy generation/storage system (engine, fuel cells, or batteries) to the alternating current (AC) that vehicle propulsion motors use. Vehicle support systems, such as lights and air conditioning, also use the inverter AC output. Distributed energy systems require an inverter to provide the high quality AC output that energy system customers demand. Today's inverters are expensive due to the cost of the power electronics components, and system designers must also tailor the inverter for individual applications. Thus, the benefits of mass production are not available, resulting in high initial procurement costs as well as high inverter maintenance and repair costs. Electricore, Inc. (www.electricore.org) a public good 501 (c) (3) not-for-profit advanced technology development consortium assembled a highly qualified team consisting of AeroVironment Inc. (www.aerovironment.com) and Delphi Automotive Systems LLC (Delphi), (www.delphi.com), as equal tiered technical leads, to develop an advanced, modular construction, inverter packaging technology that will offer a 30% cost reduction over conventional designs adding to the development of energy conversion technologies for crosscutting applications in the building, industry, transportation, and utility sectors. The proposed inverter allows for a reduction of weight and size of power electronics in the above-mentioned sectors and is scalable over the range of 15 to 500kW. The main objective of this program was to optimize existing AeroVironment inverter technology to improve power density, reliability and producibility as well as develop new topology to reduce line filter size. The newly developed inverter design will be used in automotive and distribution generation applications. In the first part of this program the high-density power stages were redesigned, optimized and fabricated. One of the main tasks was to design and validate new gate drive circuits to provide the capability of high temp operation. The new power stages and controls were later validated through extensive performance, durability and environmental tests. To further validate the design, two power stages and controls were integrated into a grid-tied load bank test fixture, a real application for field-testing. This fixture was designed to test motor drives with PWM output up to 50kW. In the second part of this program the new control topology based on sub-phases control and interphase transformer technology was successfully developed and validated. The main advantage of this technology is to reduce magnetic mass, loss and current ripple. This report summarizes the results of the advanced modular inverter technology development and details: (1) Power stage development and fabrication (2) Power stage validation testing (3) Grid-tied test fixture fabrication and initial testing (4) Interphase transformer technology development

  1. Bi-level Multi-Source Learning for Heterogeneous Block-wise Missing Data

    PubMed Central

    Xiang, Shuo; Yuan, Lei; Fan, Wei; Wang, Yalin; Thompson, Paul M.; Ye, Jieping

    2013-01-01

    Bio-imaging technologies allow scientists to collect large amounts of high-dimensional data from multiple heterogeneous sources for many biomedical applications. In the study of Alzheimer's Disease (AD), neuroimaging data, gene/protein expression data, etc., are often analyzed together to improve predictive power. Joint learning from multiple complementary data sources is advantageous, but feature-pruning and data source selection are critical to learn interpretable models from high-dimensional data. Often, the data collected has block-wise missing entries. In the Alzheimer’s Disease Neuroimaging Initiative (ADNI), most subjects have MRI and genetic information, but only half have cerebrospinal fluid (CSF) measures, a different half has FDG-PET; only some have proteomic data. Here we propose how to effectively integrate information from multiple heterogeneous data sources when data is block-wise missing. We present a unified “bi-level” learning model for complete multi-source data, and extend it to incomplete data. Our major contributions are: (1) our proposed models unify feature-level and source-level analysis, including several existing feature learning approaches as special cases; (2) the model for incomplete data avoids imputing missing data and offers superior performance; it generalizes to other applications with block-wise missing data sources; (3) we present efficient optimization algorithms for modeling complete and incomplete data. We comprehensively evaluate the proposed models including all ADNI subjects with at least one of four data types at baseline: MRI, FDG-PET, CSF and proteomics. Our proposed models compare favorably with existing approaches. PMID:23988272

  2. PWR integrated safety analysis methodology using multi-level coupling algorithm

    NASA Astrophysics Data System (ADS)

    Ziabletsev, Dmitri Nickolaevich

    Coupled three-dimensional (3D) neutronics/thermal-hydraulic (T-H) system codes give a unique opportunity for a realistic modeling of the plant transients and design basis accidents (DBA) occurring in light water reactors (LWR). Examples of such DBAs are the rod ejection accidents (REA) and the main steam line break (MSLB) that constitute the bounding safety problems for pressurized water reactors (PWR). These accidents involve asymmetric 3D spatial neutronic and T-H effects during the course of the transients. The thermal margins (the peak fuel temperature, and departure from nucleate boiling ratio (DNBR)) are the measures of safety at a particular transient and need to be evaluated as accurate as possible. Modern 3D neutronics/T-H coupled codes estimate the safety margins coarsely on an assembly level, i.e. for an average fuel pin. More accurate prediction of the safety margins requires the evaluation of the transient fuel rod response involving locally coupled neutronics/T-H calculations. The proposed approach is to perform an on-line hot-channel safety analysis not for the whole core but for a selected local region, for example for the highest power loaded fuel assembly. This approach becomes feasible if an on-line algorithm capable to extract the necessary input data for a sub-channel module is available. The necessary input data include the detailed pin-power distributions and the T-H boundary conditions for each sub-channel in the considered problem. Therefore, two potential challenges are faced in the development of refined methodology for evaluation of local safety parameters. One is the development of an efficient transient pin-power reconstruction algorithm with a consistent cross-section modeling. The second is the development of a multi-level coupling algorithm for the T-H boundary and feed-back data exchange between the sub-channel module and the main 3D neutron kinetics/T-H system code, which already uses one level of coupling scheme between 3D neutronics and core thermal-hydraulics models. The major accomplishment of the thesis is the development of an integrated PWR safety analysis methodology with locally refined safety evaluations. This involved introduction of an improved method capable of efficiently restoring the fine pin-power distribution with a high degree of accuracy. In order to apply the methodology to evaluate the safety margins on a pin level, a refined on-line hot channel model was developed accounting for the cross-flow effects. Finally, this methodology was applied to best estimate safety analysis to more accurately calculate the thermal safety margins occurring during a design basis accident in PWR.

  3. Sensitivity of Aerosol Multi-Sensor Daily Data Intercomparison to Level 3 Dataday Definition

    NASA Astrophysics Data System (ADS)

    Leptoukh, Gregory; Lary, David; Lynnes, Chritopher; Shen, Suhung

    2010-05-01

    One of the main goals of current research on the global distribution and impact of aerosols is the development of a multi-sensor merged or composite dataset of aerosol properties. With more and more aerosol data being available, at various spatial and temporal scales, from various spaceborn sensors, it is difficult to reach consensus derived from these heterogeneous observations. It is important to identify the sources of the differences observed by the various satellite datasets with each other and with model data. One approach has been to compare gridded Level 3 daily data that show differences usually attributed to differences in calibration, retrieval algorithms, cloud filtering, processing details and other issues. In the present paper, we address other aspects of differences between daily Level 3 aerosol data measured by different sensors that significantly contribute to the overall differences in the area around the international dateline, i.e., around the 180 deg longitude. One aspect is the different definition of the data day employed by different science teams; another is related to the fact that, for example, sensors onboard the Terra satellite perform aerosol (daytime) measurements during the descending part of the orbit, while those on Aqua (being part of the A-Train constellation) performs aerosol measurements in the ascending mode. These differences lead to significant time difference between measurements made by sensors on different satellites in some areas, thus (due to spatial and temporal variability of aerosols) lowering correlation between aerosol measurements. We demonstrate that (i) the effect of dataday definition leads to having spatially close measurements coming from orbits separated by about 23 hours (usually, these are the first and last orbits of a day) and (ii) the actual overpass time difference (several hours) is also being modulated by Terra and Aqua daytime measurements being collected during descending and ascending nodes respectively. The so-called spatial dataday definition that preserves the spatial continuity going from one orbit to another has been employed by AIRS, OMI, TOMS, TOVS, AVHRR for atmospheric products and most of the ocean data products. MODIS atmospheric group, on the other hand, has chosen to include Level 2 granules that span a 24-hour (00:00:00 to 23:59:59 UTC) interval, which leads to discontinuities around the dateline. We demonstrate that when the spatial dataday definition is applied to MODIS data, the artifact around the dateline in the correlation map between Terra and Aqua goes away. We conclude that to compare daily Level 3 data in a reasonable way, data from all sensors should be processed consistently using the spatial dataday definition.

  4. Putting Poverty in Political Context: A Multi-Level Analysis of Adult Poverty across 18 Affluent Democracies

    ERIC Educational Resources Information Center

    Brady, David; Fullerton, Andrew S.; Cross, Jennifer Moren

    2009-01-01

    Our study analyzes how political context, embodied by the welfare state and Leftist political actors, shapes individual poverty. Using the Luxembourg Income Study, we conduct a multi-level analysis of working-aged adult poverty across 18 affluent Western democracies. Our index of welfare generosity has a negative effect on poverty net of…

  5. Multi-Level Discourse Analysis in a Physics Teaching Methods Course from the Psychological Perspective of Activity Theory

    ERIC Educational Resources Information Center

    Vieira, Rodrigo Drumond; Kelly, Gregory J.

    2014-01-01

    In this paper, we present and apply a multi-level method for discourse analysis in science classrooms. This method is based on the structure of human activity (activity, actions, and operations) and it was applied to study a pre-service physics teacher methods course. We argue that such an approach, based on a cultural psychological perspective,…

  6. Putting Poverty in Political Context: A Multi-Level Analysis of Adult Poverty across 18 Affluent Democracies

    ERIC Educational Resources Information Center

    Brady, David; Fullerton, Andrew S.; Cross, Jennifer Moren

    2009-01-01

    Our study analyzes how political context, embodied by the welfare state and Leftist political actors, shapes individual poverty. Using the Luxembourg Income Study, we conduct a multi-level analysis of working-aged adult poverty across 18 affluent Western democracies. Our index of welfare generosity has a negative effect on poverty net of

  7. Multi-Level Discourse Analysis in a Physics Teaching Methods Course from the Psychological Perspective of Activity Theory

    ERIC Educational Resources Information Center

    Vieira, Rodrigo Drumond; Kelly, Gregory J.

    2014-01-01

    In this paper, we present and apply a multi-level method for discourse analysis in science classrooms. This method is based on the structure of human activity (activity, actions, and operations) and it was applied to study a pre-service physics teacher methods course. We argue that such an approach, based on a cultural psychological perspective,

  8. The Development of a Multi-Level Model for Crisis Preparedness and Intervention in the Greek Educational System

    ERIC Educational Resources Information Center

    Hatzichristiou, Chryse; Issari, Philia; Lykitsakou, Konstantina; Lampropoulou, Aikaterini; Dimitropoulou, Panayiota

    2011-01-01

    This article proposes a multi-level model for crisis preparedness and intervention in the Greek educational system. It presents: a) a brief overview of leading models of school crisis preparedness and intervention as well as cultural considerations for contextually relevant crisis response; b) a description of existing crisis intervention

  9. 21 CFR 184.1859 - Invert sugar.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... solution of inverted or partly inverted, refined or partly refined sucrose, the solids of which contain not... sweetness. It is produced by the hydrolysis or partial hydrolysis of sucrose with safe and suitable acids...

  10. 21 CFR 184.1859 - Invert sugar.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... solution of inverted or partly inverted, refined or partly refined sucrose, the solids of which contain not... sweetness. It is produced by the hydrolysis or partial hydrolysis of sucrose with safe and suitable acids...

  11. Inverting an Introductory Statistics Classroom

    ERIC Educational Resources Information Center

    Kraut, Gertrud L.

    2015-01-01

    The inverted classroom allows more in-class time for inquiry-based learning and for working through more advanced problem-solving activities than does the traditional lecture class. The skills acquired in this learning environment offer benefits far beyond the statistics classroom. This paper discusses four ways that can make the inverted…

  12. Is Preventative Long-Segment Surgery for Multi-Level Spondylolysis Necessary? A Finite Element Analysis Study

    PubMed Central

    Zhong, Dongyan; Xu, Hao; Wang, Lan; Yu, Jia; Luo, Zongping

    2016-01-01

    Objective For multi-level spondylolysis patients, surgeons commonly choose to fix all the segments with pars interarticularis defect even those without slippage and not responsible for clinical symptoms. In this study, we tried to study the necessity of the preventative long-segment surgery for the defected segment without slippage in treatment of multi-level spondylolysis patients from a biomechanical perspective. Method We established a bi-level spondylolysis model with pars defects at L4 and L5 segments, and simulated posterior lumbar interbody fusion (PLIF) and pedicle screw fixation at L5-S1 level. Then we compared the biomechanical changes at L4 segment before and after surgery in neutral, flexion, extension, lateral bending and axial rotation position. Results The stress on L4 pars interarticularis was very similar before and after surgery, and reached the highest in axial rotation. The L3-L4 intradiscal pressure was almost the same, while L4-L5 intradiscal pressure changed a little in lateral bending (increase from 1.993 to 2.160 MPa) and axial rotation (decrease from 1.639 to 1.307 MPa) after surgery. The PLIF surgery caused a little increase of range of motion at adjacent L4-L5 and L3-L4 levels, but the change is very tiny (1 degree). Conclusion The PLIF surgery will not cause significant biomechanical change at adjacent segment with pars defect in multi-level spondylolysis. On the contrary, excessive long-segment surgery will damage surrounding soft tissues which are important for maintaining the stability of spine. So a preventative long-segment surgery is not necessary for multi-level spondylolysis as long as there are no soft tissue degeneration signs at adjacent level. PMID:26918333

  13. Comparison of TID Response and SEE Characterization of Single and Multi Level High Density NAND Flash Memories

    NASA Technical Reports Server (NTRS)

    Irom, Farokh; Nguyen, Duc N.; Harboe-Sorensen, Reno; Virtanen, Ari

    2009-01-01

    Heavy ion single-event measurements and TID response for 8Gb commercial NAND flash memories are reported. Radiation results of multi-level flash technology are compared with results from single-level flash technology. In general, these commercial high density memories appear to be much less susceptible to SEE and have better TID response compared to older generations of flash memories. The charge pump survived up to 600 krads.

  14. In situ impact assessment of wastewater effluents by integrating multi-level biomarker responses in the pale chub (Zacco platypus).

    PubMed

    Kim, Woo-Keun; Jung, Jinho

    2016-06-01

    The integration of biomarker responses ranging from the molecular to the individual level is of great interest for measuring the toxic effects of hazardous chemicals or effluent mixtures on aquatic organisms. This study evaluated the effects of wastewater treatment plant (WWTP) effluents on the freshwater pale chub Zacco platypus by using multi-level biomarker responses at molecular [mRNA expression of catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), and metallothionein (MT)], biochemical (enzyme activities of CAT, SOD, GST, and concentration of MT), and physiological [condition factor (CF) and liver somatic index (LSI)] levels. The mRNA expression levels of GST and MT in Z. platypus from a site downstream of a WWTP significantly increased by 2.2- and 4.5-fold (p<0.05) when compared with those from an upstream site. However, the enzyme activities of CAT, SOD, and GST in fish from the downstream site significantly decreased by 43%, 98%, and 13%, respectively (p<0.05), except for an increase in MT concentration (41%). In addition, a significant increase in LSI (46%) was observed in Z. platypus from the downstream site (p<0.05). Concentrations of Cu, Zn, Cd, and Pb in the liver of Z. platypus were higher (530%, 353%, 800%, and 2,200%, respectively) in fish from a downstream site than in fish from an upstream location, and several multi-level biomarker responses were significantly correlated with the accumulated metals in Z. platypus (p<0.05). Integrated biomarker responses at molecular, biochemical, and physiological levels (multi-level IBR) were much higher (about 4-fold) at the downstream site than at the upstream site. This study suggests that the multi-level IBR approach is very useful for quantifying in situ adverse effects of WWTP effluents. PMID:26967356

  15. Costs and quality of hospitals in different health care systems: a multi-level approach with propensity score matching.

    PubMed

    Schreygg, Jonas; Stargardt, Tom; Tiemann, Oliver

    2011-01-01

    Cross-country comparisons of costs and quality between hospitals are often made at the macro level. The goal of this study was to explore methods to compare micro-level data from hospitals in different health care systems. To do so, we developed a multi-level framework in combination with a propensity score matching technique using similarly structured data for patients receiving treatment for acute myocardial infarction in German and US Veterans Health Administration hospitals. Our case study shows important differences in results between multi-level regressions based on matched and unmatched samples. We conclude that propensity score matching techniques are an appropriate way to deal with the usual baseline imbalances across the samples from different countries. Multi-level models are recommendable to consider the clustered structure of the data when patient-level data from different hospitals and health care systems are compared. The results provide an important justification for exploring new ways in performing health system comparisons. PMID:20084662

  16. Health Behavior Change Models for HIV Prevention and AIDS Care: Practical Recommendations for a Multi-Level Approach

    PubMed Central

    Cornish, Flora; Zimmerman, Rick S.; Johnson, Blair T.

    2014-01-01

    Abstract: Despite increasing recent emphasis on the social and structural determinants of HIV-related behavior, empirical research and interventions lag behind, partly because of the complexity of social–structural approaches. This article provides a comprehensive and practical review of the diverse literature on multi-level approaches to HIV-related behavior change in the interest of contributing to the ongoing shift to more holistic theory, research, and practice. It has the following specific aims: (1) to provide a comprehensive list of relevant variables/factors related to behavior change at all points on the individual–structural spectrum, (2) to map out and compare the characteristics of important recent multi-level models, (3) to reflect on the challenges of operating with such complex theoretical tools, and (4) to identify next steps and make actionable recommendations. Using a multi-level approach implies incorporating increasing numbers of variables and increasingly context-specific mechanisms, overall producing greater intricacies. We conclude with recommendations on how best to respond to this complexity, which include: using formative research and interdisciplinary collaboration to select the most appropriate levels and variables in a given context; measuring social and institutional variables at the appropriate level to ensure meaningful assessments of multiple levels are made; and conceptualizing intervention and research with reference to theoretical models and mechanisms to facilitate transferability, sustainability, and scalability. PMID:25007194

  17. Multi-level parameter structure identification for two-phase porous-media flow problems using flexible representations

    NASA Astrophysics Data System (ADS)

    Berre, Inga; Lien, Martha; Mannseth, Trond

    2009-12-01

    We consider identification of absolute permeability (hydraulic conductivity) based on time series of pressure data in sparsely distributed wells for two-phase porous-media flow. For this problem, it is impossible to recover all details of the parameter function. On the other hand, a coarser, approximate recovery may be sufficient for many applications. We propose a novel solution approach, based on reparametrization, for such approximate identification of the parameter function. We use a nonlinear, composite representation, which is detached from the computational grid, allowing for a flexible representation of the parameter function at many resolution levels. This is utilized in a sequential multi-level estimation of the parameter function, starting at a coarse resolution, which is then gradually refined. The composite representation is designed to allow for smooth as well as sharp transitions between regions of nearly constant parameter value. Moreover, it facilitates the estimation also of the structure and smoothness of the parameter function itself. As a limiting case, the chosen representation is reduced to a zonation with implicit representation of the interior boundaries that is equivalent to a level-set representation. A motivation for the selected representation and the multi-level estimation is presented in terms of an analysis of sensitivity and nonlinearity. Numerical examples demonstrate identification of coarse-scale features of reference permeability distributions with varying degree of smoothness. Comparisons show how the multi-level strategy stabilize the identification and avoid local minima of the objective function compared to a single-level strategy.

  18. Health behavior change models for HIV prevention and AIDS care: practical recommendations for a multi-level approach.

    PubMed

    Kaufman, Michelle R; Cornish, Flora; Zimmerman, Rick S; Johnson, Blair T

    2014-08-15

    Despite increasing recent emphasis on the social and structural determinants of HIV-related behavior, empirical research and interventions lag behind, partly because of the complexity of social-structural approaches. This article provides a comprehensive and practical review of the diverse literature on multi-level approaches to HIV-related behavior change in the interest of contributing to the ongoing shift to more holistic theory, research, and practice. It has the following specific aims: (1) to provide a comprehensive list of relevant variables/factors related to behavior change at all points on the individual-structural spectrum, (2) to map out and compare the characteristics of important recent multi-level models, (3) to reflect on the challenges of operating with such complex theoretical tools, and (4) to identify next steps and make actionable recommendations. Using a multi-level approach implies incorporating increasing numbers of variables and increasingly context-specific mechanisms, overall producing greater intricacies. We conclude with recommendations on how best to respond to this complexity, which include: using formative research and interdisciplinary collaboration to select the most appropriate levels and variables in a given context; measuring social and institutional variables at the appropriate level to ensure meaningful assessments of multiple levels are made; and conceptualizing intervention and research with reference to theoretical models and mechanisms to facilitate transferability, sustainability, and scalability. PMID:25007194

  19. A multi-level strategy for anticipating future glacier lake formation and associated hazard potentials

    NASA Astrophysics Data System (ADS)

    Frey, Holger; Haeberli, Wilfried; Huggel, Christian; Linsbauer, Andreas

    2010-05-01

    Due to the expected atmospheric warming, mountain glaciers will retreat, potentially collapse or even vanish completely during the 21st century. When overdeepened parts of the glacier bed are exposed in the course of glacier retreat, glacier lakes can form. Such lakes have a potential for hydropower production, which is an important source of renewable energy. Furthermore they are important elements in the perception of high-mountain landscapes and they can compensate the loss of landscape attractiveness from glacier shrinkage to a certain degree. However, glacier lakes are also a potential source of serious flood and debris flow hazards, especially in densely populated mountain ranges. Thus, methods for early detection of sites with potential lake formation are important for early planning and development of protection concepts. In this contribution we present a multi-scale approach to detect sites with potential future lake formation on four different levels of detail. The methods are developed, tested and - as far as possible - verified in the Swiss Alps; but they can be applied to mountain regions all over the world. On a first level, potential overdeepenings are estimated by selecting flat parts (slope < 5) of the current glacier surface based on a digital elevation model (DEM) and digital glacier outlines. The same input data are used on the second level for a manual detection of overdeepenings, which are expected at locations where the following three criteria apply: (a) A distinct increase of the glacier surface slope in down-glacier direction; (b) an enlarged width followed by a narrow glacier part; and (c) regions with compressive flow (no crevasses) followed by extending flow (heavily crevassed). On the third level, more sophisticated approaches to model the glacier bed topography are applied to get more quantitative information on potential future lakes. Based on the results of this level, scenarios of future lake outbursts can be modeled with simple flow routing models. Finally, for potentially critical or dangerous situations, on-site geophysical measurements such as ground penetrating radar applied on different sections of a glacier can be performed on the fourth level to investigate the overdeepenings in more detail. These methods are verified based on historical data from the Trift glacier in the Bernese Alps, where a lake formed in front of the glacier since the 1990s up to the present. Potential future lake scenarios are presented for two regions in the Swiss Alps and the outburst potential of such future lakes is investigated for the Bernina region. The proposed method is an important step towards early detection of new potential flood hazards related to rapid glacier retreat. At the same time, it can form a basis for an integrative risk and benefit management relating to new glacier lakes.

  20. 21 CFR 184.1859 - Invert sugar.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Invert sugar. 184.1859 Section 184.1859 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS 184.1859 Invert sugar. (a) Invert sugar (CAS...

  1. Improved Performance via the Inverted Classroom

    ERIC Educational Resources Information Center

    Weinstein, Randy D.

    2015-01-01

    This study examined student performance in an inverted thermodynamics course (lectures provided by video outside of class) compared to a traditional lecture class. Students in the inverted class performed better on their exams. Students in the bottom third of the inverted course showed the greatest improvement. These bottom third students had a C

  2. Improved Performance via the Inverted Classroom

    ERIC Educational Resources Information Center

    Weinstein, Randy D.

    2015-01-01

    This study examined student performance in an inverted thermodynamics course (lectures provided by video outside of class) compared to a traditional lecture class. Students in the inverted class performed better on their exams. Students in the bottom third of the inverted course showed the greatest improvement. These bottom third students had a C…

  3. Socioeconomic Status and the Health of Youth: A Multi-level, Multi-domain Approach to Conceptualizing Pathways

    PubMed Central

    Schreier, Hannah M. C.; Chen, Edith

    2012-01-01

    Previous research has clearly established associations between low socioeconomic status (SES) and poor youth physical health outcomes. This article provides an overview of the main pathways through which low SES environments come to influence youth health. We focus on two of the most prevalent chronic health problems in youth today, asthma and obesity. We review and propose a model that encompasses (1) multiple levels of influence, including the neighborhood, family and person level, (2) both social and physical domains in the environment, and finally (3) dynamic relationships between these factors. A synthesis of existing research and our proposed model draw attention to the notion of adverse physical and social exposures in youth’s neighborhood environments altering family characteristics and youth psychosocial and behavioral profiles, thereby increasing youth’s risk for health problems. We also note the importance of acknowledging reciprocal influences across levels and domains (e.g., between family and child) that create self-perpetuating patterns of influence that further accentuate the impact of these factors on youth health. Finally, we document that factors across levels can interact (e.g., environmental pollution levels with child stress) to create unique, synergistic effects on youth health. Our model stresses the importance of evaluating influences on youth’s physical health not in isolation but in the context of the broader social and physical environments in which youth live. Understanding the complex relationships between the factors that link low SES to youth’s long-term health trajectories is necessary for the creation and implementation of successful interventions and policies to ultimately reduce health disparities. PMID:22845752

  4. Delineating Reactive Natural Attenuation Zones: Multi-level Sampling in an Ammonium Plume

    NASA Astrophysics Data System (ADS)

    Httmann, A.; Wilson, R. D.; Thornton, S. F.; Lerner, D. N.

    2003-12-01

    Current natural attenuation monitoring involves observing concentrations along some transect parallel to flow, often in long--screened observation wells. Vertically integrated geochemical signals essentially compresses 3D-problems into 2D ones and the loss of process resolution does not allow for robust plume transport prediction. On the other hand, a monitoring approach that is based on process quantification will yield field data necessary for current natural attenuation assessment and allow more accurate prediction to plume behaviour. To quantify these spatially discrete processes, the resolution of sampling points must be higher to delineate reactive zones, that account for the bulk of natural attenuation. These reactive zones are dependent on aquifer properties, contaminant type, redox zonation and other factors. In many cases, the plume fringe will be the most active zone, because influx of certain nutrients necessary to support bacteria will be greatest in these zones. Most importantly, consortia of degrading bacteria are dependent on supply of electron--acceptors such as dissolved {O2} and nitrate from background ground water and recharge; electron--acceptors are rapidly consumed at the fringes and concentrations decrease significantly towards the centre of the plume. Thus, if a process--based approach is to be achieved, one has to focus not only on the overall extent and mass of a contaminant plume, but, more importantly, on a sound analysis of the most reactive zones. The site of a former coal processing plant in the UK was chosen as a field site where the afore--mentioned hypothesis is currently being investigated by means of two recently installed multi--level samplers. Previous investigations have located an ammonium plume at the site with outwash from the thick unsaturated zone as ongoing source since the demolition of the actual plant in 1970. The conceptual model drawn from the analysis of these data shows that certain zones exhibit higher rates of degradation than others, but the extent of these zones and rates of degradation could not be determined with the sampling methods used in previous investigations. Spacing between the sampling ports in the newly installed multi--level samplers is 25cm across the top fringe of the plume, and the ground water is analysed for contaminants, general redox chemistry of the aquifer, and isotopes. The analysis of groundwater samples from a first sampling round performed in late summer 2003 shows that i) nitrification is ongoing at the upper fringe in a zone about 0.5m thick, but concentrations of nitrate encountered at the ports across the fringe are higher that derived from the degradation of available ammonium; ii) concentrations of electron--donors and --acceptors change rapidly in the fringe--zone; iii) inside the plume, different processes are prevalent than at the upper fringe; iv) a trend in the isotopic composition appears to indicate a distinct consumption of carbon and sulphate by microbial activity, but these data are not unequivocal and should only be used as supportive evidence.

  5. A dedicated database system for handling multi-level data in systems biology

    PubMed Central

    2014-01-01

    Background Advances in high-throughput technologies have enabled extensive generation of multi-level omics data. These data are crucial for systems biology research, though they are complex, heterogeneous, highly dynamic, incomplete and distributed among public databases. This leads to difficulties in data accessibility and often results in errors when data are merged and integrated from varied resources. Therefore, integration and management of systems biological data remain very challenging. Methods To overcome this, we designed and developed a dedicated database system that can serve and solve the vital issues in data management and hereby facilitate data integration, modeling and analysis in systems biology within a sole database. In addition, a yeast data repository was implemented as an integrated database environment which is operated by the database system. Two applications were implemented to demonstrate extensibility and utilization of the system. Both illustrate how the user can access the database via the web query function and implemented scripts. These scripts are specific for two sample cases: 1) Detecting the pheromone pathway in protein interaction networks; and 2) Finding metabolic reactions regulated by Snf1 kinase. Results and conclusion In this study we present the design of database system which offers an extensible environment to efficiently capture the majority of biological entities and relations encountered in systems biology. Critical functions and control processes were designed and implemented to ensure consistent, efficient, secure and reliable transactions. The two sample cases on the yeast integrated data clearly demonstrate the value of a sole database environment for systems biology research. PMID:25053973

  6. Enhancing K-12 Ocean Science Education Through Multi-level Partnership

    NASA Astrophysics Data System (ADS)

    Greely, T. M.; Coble, P.; Betzer, P. R.

    2003-12-01

    This paper highlights the results of long-term collaborations between the University of South Florida's College of Marine Science (CMS) and the Pinellas County school district (22nd largest nationally) to advance and improve K-12 Earth/Ocean science education. The 12-year mission of Education and Public Outreach (EPO) in the College of Marine Science has been to meaningfully integrate ocean science research and science learning to enhance K-12 education for teachers and students. Our interactive and interdisciplinary programs include research cruises, field trips, authentic research projects, satellite broadcasts, and web-based technologies. This paper will focus on two programs, the Oceanography Camp for Girls and Teachers and Project Oceanography. We will address impact of these programs, what works, the role and value of partnerships, sustainability and future initiatives. An especially critical aspect of EPO is partnerships. Our partners include people, scientific facilities, community, and donors. Financial partnerships provide sustainability and continuity. For example, private donors have built a series of endowments to support the Oceanography Camp for Girls currently valued at over \\$1 million. Given the recent shift in state and federal funding priorities, private funding is a vital element of successful EPO programs. To date, marine science EPO partnerships have included 34 state agencies, universities, private research laboratories, schools, and museums; 75 scientist, advanced graduate students and teachers as co-instructors; 4 television stations and 2 production companies; and over 2,000,000 participants in 7 countries. Multi-level partnerships are enhancing K-12 classrooms around the world with relevant ocean science content and resources to further science interests, ocean awareness, and informed decision making.

  7. Assessment and quantification of post-weaning multi-systemic wasting syndrome severity at farm level.

    PubMed

    Alarcon, Pablo; Velasova, Martina; Werling, Dirk; Strk, Katharina D C; Chang, Yu-Mei; Nevel, Amanda; Pfeiffer, Dirk U; Wieland, Barbara

    2011-01-01

    Post-weaning multi-systemic wasting syndrome (PMWS) causes major economic losses for the English pig industry and severity of clinical signs and economic impact vary considerably between affected farms. We present here a novel approach to quantify severity of PMWS based on morbidity and mortality data and presence of porcine circovirus type 2 (PCV2). In 2008-2009, 147 pig farms across England, non-vaccinating for PCV2, were enrolled in a cross-sectional study. Factor analysis was used to generate variables representing biologically meaningful aspects of variation among qualitative and quantitative morbidity variables. Together with other known variables linked to PMWS, the resulting factors were included in a principal component analysis (PCA) to derive an algorithm for PMWS severity. Factor analysis resulted in two factors: Morbidity Factor 1 (MF1) representing mainly weaner and grower morbidity, and Morbidity Factor 2 (MF2) which mainly reflects variation in finisher morbidity. This indicates that farms either had high morbidity mainly in weaners/growers or mainly in finishers. Subsequent PCA resulted in the extraction of one component representing variation in MF1, post-weaning mortality and percentage of PCV2 PCR positive animals. Component scores were normalised to a value range from 0 to 10 and farms classified into: non or slightly affected farms with a score <4, moderately affected farms with scores 4-6.5 and highly affected farms with a score >6.5. The identified farm level PMWS severities will be used to identify risk factors related to these, to assess the efficacy of PCV2 vaccination and investigating the economic impact of potential control measures. PMID:21036410

  8. Resource atlases for multi-atlas brain segmentations with multiple ontology levels based on T1-weighted MRI.

    PubMed

    Wu, Dan; Ma, Ting; Ceritoglu, Can; Li, Yue; Chotiyanonta, Jill; Hou, Zhipeng; Hsu, John; Xu, Xin; Brown, Timothy; Miller, Michael I; Mori, Susumu

    2016-01-15

    Technologies for multi-atlas brain segmentation of T1-weighted MRI images have rapidly progressed in recent years, with highly promising results. This approach, however, relies on a large number of atlases with accurate and consistent structural identifications. Here, we introduce our atlas inventories (n=90), which cover ages 4-82years with unique hierarchical structural definitions (286 structures at the finest level). This multi-atlas library resource provides the flexibility to choose appropriate atlases for various studies with different age ranges and structure-definition criteria. In this paper, we describe the details of the atlas resources and demonstrate the improved accuracy achievable with a dynamic age-matching approach, in which atlases that most closely match the subject's age are dynamically selected. The advanced atlas creation strategy, together with atlas pre-selection principles, is expected to support the further development of multi-atlas image segmentation. PMID:26499813

  9. RNA-Seq and molecular docking reveal multi-level pesticide resistance in the bed bug

    PubMed Central

    2012-01-01

    Background Bed bugs (Cimex lectularius) are hematophagous nocturnal parasites of humans that have attained high impact status due to their worldwide resurgence. The sudden and rampant resurgence of C. lectularius has been attributed to numerous factors including frequent international travel, narrower pest management practices, and insecticide resistance. Results We performed a next-generation RNA sequencing (RNA-Seq) experiment to find differentially expressed genes between pesticide-resistant (PR) and pesticide-susceptible (PS) strains of C. lectularius. A reference transcriptome database of 51,492 expressed sequence tags (ESTs) was created by combining the databases derived from de novo assembled mRNA-Seq tags (30,404 ESTs) and our previous 454 pyrosequenced database (21,088 ESTs). The two-way GLMseq analysis revealed ~15,000 highly significant differentially expressed ESTs between the PR and PS strains. Among the top 5,000 differentially expressed ESTs, 109 putative defense genes (cuticular proteins, cytochrome P450s, antioxidant genes, ABC transporters, glutathione S-transferases, carboxylesterases and acetyl cholinesterase) involved in penetration resistance and metabolic resistance were identified. Tissue and development-specific expression of P450 CYP3 clan members showed high mRNA levels in the cuticle, Malpighian tubules, and midgut; and in early instar nymphs, respectively. Lastly, molecular modeling and docking of a candidate cytochrome P450 (CYP397A1V2) revealed the flexibility of the deduced protein to metabolize a broad range of insecticide substrates including DDT, deltamethrin, permethrin, and imidacloprid. Conclusions We developed significant molecular resources for C. lectularius putatively involved in metabolic resistance as well as those participating in other modes of insecticide resistance. RNA-Seq profiles of PR strains combined with tissue-specific profiles and molecular docking revealed multi-level insecticide resistance in C. lectularius. Future research that is targeted towards RNA interference (RNAi) on the identified metabolic targets such as cytochrome P450s and cuticular proteins could lay the foundation for a better understanding of the genetic basis of insecticide resistance in C. lectularius. PMID:22226239

  10. Family, Community and Clinic Collaboration to Treat Overweight and Obese Children: Stanford GOALS -- a Randomized Controlled Trial of a Three-Year, Multi-Component, Multi-Level, Multi-Setting Intervention

    PubMed Central

    Robinson, Thomas N.; Matheson, Donna; Desai, Manisha; Wilson, Darrell M.; Weintraub, Dana L.; Haskell, William L.; McClain, Arianna; McClure, Samuel; Banda, Jorge; Sanders, Lee M.; Haydel, K. Farish; Killen, Joel D.

    2013-01-01

    Objective To test the effects of a three-year, community-based, multi-component, multi-level, multi-setting (MMM) approach for treating overweight and obese children. Design Two-arm, parallel group, randomized controlled trial with measures at baseline, 12, 24, and 36 months after randomization. Participants Seven through eleven year old, overweight and obese children (BMI ≥ 85th percentile) and their parents/caregivers recruited from community locations in low-income, primarily Latino neighborhoods in Northern California. Interventions Families are randomized to the MMM intervention versus a community health education active-placebo comparison intervention. Interventions last for three years for each participant. The MMM intervention includes a community-based after school team sports program designed specifically for overweight and obese children, a home-based family intervention to reduce screen time, alter the home food/eating environment, and promote self-regulatory skills for eating and activity behavior change, and a primary care behavioral counseling intervention linked to the community and home interventions. The active-placebo comparison intervention includes semi-annual health education home visits, monthly health education newsletters for children and for parents/guardians, and a series of community-based health education events for families. Main Outcome Measure Body mass index trajectory over the three-year study. Secondary outcome measures include waist circumference, triceps skinfold thickness, accelerometer-measured physical activity, 24-hour dietary recalls, screen time and other sedentary behaviors, blood pressure, fasting lipids, glucose, insulin, hemoglobin A1c, C-reactive protein, alanine aminotransferase, and psychosocial measures. Conclusions The Stanford GOALS trial is testing the efficacy of a novel community-based multi-component, multi-level, multi-setting treatment for childhood overweight and obesity in low-income, Latino families. PMID:24028942

  11. Thermal Study of Inverter Components: Preprint

    SciTech Connect

    Sorensen, N. R.; Thomas, E. V.; Quintana, M. A.; Barkaszi, S.; Rosenthal, A.; Zhang, Z.; Kurtz, S.

    2012-06-01

    Thermal histories of inverter components were collected from operating inverters from several manufacturers and three locations. The data were analyzed to determine thermal profiles, the dependence on local conditions, and to assess the effect on inverter reliability. Inverter temperatures were shown to increase with the power dissipation of the inverters, follow diurnal and annual cycles, and have a dependence on wind speed. An accumulated damage model was applied to the temperature profiles and an example of using these data to predict reliability was explored.

  12. Two-bit multi-level phase change random access memory with a triple phase change material stack structure

    NASA Astrophysics Data System (ADS)

    Gyanathan, Ashvini; Yeo, Yee-Chia

    2012-11-01

    This work demonstrates a novel two-bit multi-level device structure comprising three phase change material (PCM) layers, separated by SiN thermal barrier layers. This triple PCM stack consisted of (from bottom to top), Ge2Sb2Te5 (GST), an ultrathin SiN barrier, nitrogen-doped GST, another ultrathin SiN barrier, and Ag0.5In0.5Sb3Te6. The PCM layers can selectively amorphize to form 4 different resistance levels ("00," "01," "10," and "11") using respective voltage pulses. Electrical characterization was extensively performed on these devices. Thermal analysis was also done to understand the physics behind the phase changing characteristics of the two-bit memory devices. The melting and crystallization temperatures of the PCMs play important roles in the power consumption of the multi-level devices. The electrical resistivities and thermal conductivities of the PCMs and the SiN thermal barrier are also crucial factors contributing to the phase changing behaviour of the PCMs in the two-bit multi-level PCRAM device.

  13. Three-phase multilevel solar inverter for motor drive system

    NASA Astrophysics Data System (ADS)

    Bhasagare, Mayuresh P.

    This thesis deals with three phase inverters and the different control strategies that can be associated with an inverter being used together. The first part of this thesis discusses the present research in the fields of PV panels, motor drive systems and three phase inverters along with their control. This control includes various strategies like MPPT, Volts-Hertz and modulation index compensation. Incorporating these techniques together is the goal of this thesis. A new topology for operating an open end motor drive system has also been discusses, where a boost converter and a flyback converter have been used in cascade to run a three phase motor. The main advantage of this is increasing the number of levels and improving the quality of the output voltage, not to mention a few other benefits of having the proposed circuit. A new algorithm has also been designed for starting and stopping the motor, which controls the current drawn from the power source during starting.

  14. Suspended Patch Antenna Array With Electromagnetically Coupled Inverted Microstrip Feed

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.

    2000-01-01

    The paper demonstrates a four-element suspended patch antenna array, with a parasitic patch layer and an electromagnetically coupled inverted microstrip feed, for linear polarization at K-Band frequencies. This antenna has the following advantages over conventional microstrip antennas: First, the inverted microstrip has lower attenuation than conventional microstrip; hence, conductor loss associated with the antenna corporate feed is lower resulting in higher gain and efficiency. Second, conventional proximity coupled patch antennas require a substrate for the feed and a superstrate for the patch. However, the inverted microstrip fed patch antenna makes use of a single substrate, and hence, is lightweight and low cost. Third, electromagnetic coupling results in wider bandwidth. Details regarding the design and fabrication will be presented as well as measured results including return loss, radiation patterns and cross-polarization levels.

  15. Evaluation of recent residential inverters

    SciTech Connect

    Nichols, B.E.

    1982-06-01

    Seven residential utility-interactive inverters for photovoltaic power systems have been evaluated at MIT Laboratory and at the Northeast Residential Experiment Station (NE RES). Two, a Windworks Gemini and an Abacus Sunverter, have been reported on previously. Reviewed here are five other inverters: Windworks Gemini 8-kW (dc) model with an ac filter to improve the output current waveform and power factor; Acheval Wind Electronics 10-kW (ac) model, Helionetics 6-kW (dc) model; and American Power Conversion 2-kW and 4-kW (ac) models. Input and output power, power factor, current waveform distortion, audio noise and radio frequency interference measurements were made at the NE RES and the results are presented.

  16. Enabling the MLSpOC (Multi-Level Space Operations Center) of the Future

    NASA Astrophysics Data System (ADS)

    Missal, D.

    2012-09-01

    The Intelligence Reform and Terrorism Prevention Act, passed by Congress in 2004, established the expectation that the "vast intelligence enterprise" of the United States would become more unified, coordinated, and effective. This law charged the intelligence community and government agencies to integrate foreign intelligence and domestic US intelligence components to reduce gaps in understanding threats to our national security and to improve our reaction. This intelligence strategy — designed to provide more comprehensive and accurate intelligence analysis—substantially increases requirements for secure data sharing capabilities. An information system must be Certified & Accredited (C&A) by the appropriate Accreditation Authority in accordance with each Authority's prescribed compliance requirements and governance. Cross-Domain Solutions (CDSs) can provide the ability to share data between multiple operating domains (e.g. among users on Top Secret and Secret networks). However, sharing sensitive data across security domains and networks has been impeded by both technical and cultural challenges. A viable CDS requires a tremendous investment for initial C&A and many solutions are limited with respect to the integration of an organization's applications. As a result, most of today's highly secured systems have been designed to restrict access to entire user populations rather than implement data sharing on the basis of mandatory access controls and an individual's need-to-know. Most CDSs today are based on one-way replication through data transfer guards that copy data from one network to another. This model inherently builds in additional and extensive Operations and Maintenance (O&M) costs. Oracle's National Security Group challenged its top engineers and security architects to engineer the first Cross-Domain database providing a practical and robust solution to the Cross-Domain security problem. The result is the MLSpOC, which is deployed, fielded, and accredited today at multiple sites both CONUS and OCONUS. It is designed to assist information systems developers achieve DCID 6/3 Protection Level 4 or 5 (PL4 or PL5) or DoD SABI C&A for SECRET-to-UNCLASSIFIED systems (PL3). The product is on the DoD/DNI Unified Cross-domain Management Office's (UCDMO) Baseline of accredited solutions, and is the only solution on the Baseline which the Government considers to be an "All-in-One" approach to the Cross-domain Security challenge. Our solution is also the only PL-4 Cloud in existence and that is deployed and operational in the entire world today (at DIA). The Space marketplace is a very unique cross-domain challenge, as a need exists for Unclassified SSA Data Sharing at a deeper and more fundamental level than anywhere else in the IC or DoD. For instance, certain Agencies and/or Programs have a requirement to share information with Partner Nations that are not considered to be "friendly" (e.g. China). Our Solution is the ONLY solution in the world today that's achieved C&A, and that is uniquely positioned to enable the Multi-level Space Operations Center (MLSpOC) of the Future.

  17. Effective switching frequency multiplier inverter

    DOEpatents

    Su, Gui-Jia (Oak Ridge, TN); Peng, Fang Z. (Okemos, MI)

    2007-08-07

    A switching frequency multiplier inverter for low inductance machines that uses parallel connection of switches and each switch is independently controlled according to a pulse width modulation scheme. The effective switching frequency is multiplied by the number of switches connected in parallel while each individual switch operates within its limit of switching frequency. This technique can also be used for other power converters such as DC/DC, AC/DC converters.

  18. The Inverted Snow Globe Shadow

    NASA Astrophysics Data System (ADS)

    Ribeiro, Jair Lcio Prados

    2015-01-01

    Our high school optics course finishes with an assignment that students usually appreciate. They must take pictures of everyday situations representing optical phenomena such as reflection, refraction, or dispersion, and post them on Instagram.1 When the photos were presented to the class, one student revealed an intriguing photo, similar to Fig. 1, showing a snow globe exposed to sunlight and its inverted shadow. This paper offers an explanation of the problem, which occurs due to light refraction from the globe.

  19. Multi-level sexual selection: individual and family-level selection for mating success in a historical human population.

    PubMed

    Moorad, Jacob A

    2013-06-01

    Precopulatory sexual selection is the association between fitness and traits associated with mate acquisition. Although sexual selection is generally recognized to be a powerful evolutionary force, most investigations are limited to characters belonging to individuals. A broader multilevel perspective acknowledges that individual fitness can be affected by aspects of mating success that are characters of groups, such as families. Parental mating success in polygynous or polyandrous human societies may exemplify traits under group-level sexual selection. Using fitness measures that account for age-structure, I measure multilevel selection for mate number over 55 years in a human population with declining rates of polygyny. Sexual selection had three components: individual-level selection for ever-mating (whether an individual mated) and individual- and family-level selection for polyandry and polygyny. Family- and individual-level selection for polygyny was equally strong, three times stronger than family-level selection for polyandry and more than an order of magnitude stronger than individual-level selection for polyandry. However, individual-level selection for polyandry and polygyny was more effective at explaining relative fitness variance than family-level selection. Selection for ever-mating was the most important source of sexual selection for fitness; variation for ever-mating explained 23% of relative fitness variance. PMID:23730758

  20. Gripper deploying and inverting linkage

    DOEpatents

    Minichan, Richard L. (23 Pineview Dr., Warrenville, SC 29851); Killian, Mark A. (102 Foxhunt Dr., North Augusta, SC 29841)

    1993-01-01

    An end effector deploying and inverting linkage. The linkage comprises an air cylinder mounted in a frame or tube, a sliding bracket next to the air cylinder, a stopping bracket depending from the frame and three, pivotally-attached links that are attached to the end effector and to each other in such a way as to be capable of inverting the end effector and translating it laterally. The first of the three links is a straight element that is moved up and down by the shaft of the air cylinder. The second link is attached at one end to the stopping bracket and to the side of the end effector at the other end. The first link is attached near the middle of the second, sharply angled link so that, as the shaft of the air cylinder moves up and down, the second link rotates about an axis perpendicular to the frame and inverts and translates the end effector. The rotation of the second link is stopped at both ends when the link engages stops on the stopping bracket. The third link, slightly angled, is attached to the sliding bracket at one end and to the end of the end effector at the other. The third helps to control the end effector in its motion.

  1. Gripper deploying and inverting linkage

    DOEpatents

    Minichan, R.L.; Killian, M.A.

    1993-03-02

    An end effector deploying and inverting linkage. The linkage comprises an air cylinder mounted in a frame or tube, a sliding bracket next to the air cylinder, a stopping bracket depending from the frame and three, pivotally-attached links that are attached to the end effector and to each other in such a way as to be capable of inverting the end effector and translating it laterally. The first of the three links is a straight element that is moved up and down by the shaft of the air cylinder. The second link is attached at one end to the stopping bracket and to the side of the end effector at the other end. The first link is attached near the middle of the second, sharply angled link so that, as the shaft of the air cylinder moves up and down, the second link rotates about an axis perpendicular to the frame and inverts and translates the end effector. The rotation of the second link is stopped at both ends when the link engages stops on the stopping bracket. The third link, slightly angled, is attached to the sliding bracket at one end and to the end of the end effector at the other. The third helps to control the end effector in its motion.

  2. Minimizing End-to-End Interference in I/O Stacks Spanning Shared Multi-Level Buffer Caches

    ERIC Educational Resources Information Center

    Patrick, Christina M.

    2011-01-01

    This thesis presents an end-to-end interference minimizing uniquely designed high performance I/O stack that spans multi-level shared buffer cache hierarchies accessing shared I/O servers to deliver a seamless high performance I/O stack. In this thesis, I show that I can build a superior I/O stack which minimizes the inter-application interference

  3. On the use of a hierarchical multi-level building block basis function scheme in periodic plasmonic structures

    NASA Astrophysics Data System (ADS)

    Zheng, X.; Valev, V. K.; Volskiy, V.; Vandenbosch, Guy A. E.; Moshchalkov, V. V.

    2014-05-01

    A Volumetric Method of Moments algorithm is applied to predict the plasmonic responses of chiral metamaterials. This algorithm is based on the use of a multi-level building block basis function scheme, in combination with a dedicated Kummer transformation in the calculation of periodic Green's functions. The validity of the algorithm is demonstrated by analyzing a Ninja Star periodic structure. A good agreement can be found between simulation and experiment.

  4. Minimizing End-to-End Interference in I/O Stacks Spanning Shared Multi-Level Buffer Caches

    ERIC Educational Resources Information Center

    Patrick, Christina M.

    2011-01-01

    This thesis presents an end-to-end interference minimizing uniquely designed high performance I/O stack that spans multi-level shared buffer cache hierarchies accessing shared I/O servers to deliver a seamless high performance I/O stack. In this thesis, I show that I can build a superior I/O stack which minimizes the inter-application interference…

  5. Knowledge, Skills, and Abilities for Entry-Level Business Analytics Positions: A Multi-Method Study

    ERIC Educational Resources Information Center

    Cegielski, Casey G.; Jones-Farmer, L. Allison

    2016-01-01

    It is impossible to deny the significant impact from the emergence of big data and business analytics on the fields of Information Technology, Quantitative Methods, and the Decision Sciences. Both industry and academia seek to hire talent in these areas with the hope of developing organizational competencies. This article describes a multi-method…

  6. Knowledge, Skills, and Abilities for Entry-Level Business Analytics Positions: A Multi-Method Study

    ERIC Educational Resources Information Center

    Cegielski, Casey G.; Jones-Farmer, L. Allison

    2016-01-01

    It is impossible to deny the significant impact from the emergence of big data and business analytics on the fields of Information Technology, Quantitative Methods, and the Decision Sciences. Both industry and academia seek to hire talent in these areas with the hope of developing organizational competencies. This article describes a multi-method

  7. Sub-genomic level sequence analysis of the aquaporin multi-gene family in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aquaporins function mainly as water transport channel proteins that facilitate water movement across intracellular and intercellular membranes in most living organisms. Plant aquaporins belong to a multi-gene family and are commonly categorized into 5 subfamilies according to sequence similarity. Re...

  8. Complex carbon cycle responses to multi-level warming and supplemental summer rain in the high Arctic.

    PubMed

    Sharp, Elizabeth D; Sullivan, Patrick F; Steltzer, Heidi; Csank, Adam Z; Welker, Jeffrey M

    2013-06-01

    The Arctic has experienced rapid warming and, although there are uncertainties, increases in precipitation are projected to accompany future warming. Climate changes are expected to affect magnitudes of gross ecosystem photosynthesis (GEP), ecosystem respiration (ER) and the net ecosystem exchange of CO2 (NEE). Furthermore, ecosystem responses to climate change are likely to be characterized by nonlinearities, thresholds and interactions among system components and the driving variables. These complex interactions increase the difficulty of predicting responses to climate change and necessitate the use of manipulative experiments. In 2003, we established a long-term, multi-level and multi-factor climate change experiment in a polar semidesert in northwest Greenland. Two levels of heating (30 and 60Wm(-2) ) were applied and the higher level was combined with supplemental summer rain. We made plot-level measurements of CO2 exchange, plant community composition, foliar nitrogen concentrations, leaf ?(13) C and NDVI to examine responses to our treatments at ecosystem- and leaf-levels. We confronted simple models of GEP and ER with our data to test hypotheses regarding key drivers of CO2 exchange and to estimate growing season CO2 -C budgets. Low-level warming increased the magnitude of the ecosystem C sink. Meanwhile, high-level warming made the ecosystem a source of C to the atmosphere. When high-level warming was combined with increased summer rain, the ecosystem became a C sink of magnitude similar to that observed under low-level warming. Competition among our ER models revealed the importance of soil moisture as a driving variable, likely through its effects on microbial activity and nutrient cycling. Measurements of community composition and proxies for leaf-level physiology suggest GEP responses largely reflect changes in leaf area of Salix arctica, rather than changes in leaf-level physiology. Our findings indicate that the sign and magnitude of the future High Arctic C budget may depend upon changes in summer rain. PMID:23504924

  9. OptCom: a multi-level optimization framework for the metabolic modeling and analysis of microbial communities.

    PubMed

    Zomorrodi, Ali R; Maranas, Costas D

    2012-02-01

    Microorganisms rarely live isolated in their natural environments but rather function in consolidated and socializing communities. Despite the growing availability of high-throughput sequencing and metagenomic data, we still know very little about the metabolic contributions of individual microbial players within an ecological niche and the extent and directionality of interactions among them. This calls for development of efficient modeling frameworks to shed light on less understood aspects of metabolism in microbial communities. Here, we introduce OptCom, a comprehensive flux balance analysis framework for microbial communities, which relies on a multi-level and multi-objective optimization formulation to properly describe trade-offs between individual vs. community level fitness criteria. In contrast to earlier approaches that rely on a single objective function, here, we consider species-level fitness criteria for the inner problems while relying on community-level objective maximization for the outer problem. OptCom is general enough to capture any type of interactions (positive, negative or combinations thereof) and is capable of accommodating any number of microbial species (or guilds) involved. We applied OptCom to quantify the syntrophic association in a well-characterized two-species microbial system, assess the level of sub-optimal growth in phototrophic microbial mats, and elucidate the extent and direction of inter-species metabolite and electron transfer in a model microbial community. We also used OptCom to examine addition of a new member to an existing community. Our study demonstrates the importance of trade-offs between species- and community-level fitness driving forces and lays the foundation for metabolic-driven analysis of various types of interactions in multi-species microbial systems using genome-scale metabolic models. PMID:22319433

  10. OptCom: A Multi-Level Optimization Framework for the Metabolic Modeling and Analysis of Microbial Communities

    PubMed Central

    Zomorrodi, Ali R.; Maranas, Costas D.

    2012-01-01

    Microorganisms rarely live isolated in their natural environments but rather function in consolidated and socializing communities. Despite the growing availability of high-throughput sequencing and metagenomic data, we still know very little about the metabolic contributions of individual microbial players within an ecological niche and the extent and directionality of interactions among them. This calls for development of efficient modeling frameworks to shed light on less understood aspects of metabolism in microbial communities. Here, we introduce OptCom, a comprehensive flux balance analysis framework for microbial communities, which relies on a multi-level and multi-objective optimization formulation to properly describe trade-offs between individual vs. community level fitness criteria. In contrast to earlier approaches that rely on a single objective function, here, we consider species-level fitness criteria for the inner problems while relying on community-level objective maximization for the outer problem. OptCom is general enough to capture any type of interactions (positive, negative or combinations thereof) and is capable of accommodating any number of microbial species (or guilds) involved. We applied OptCom to quantify the syntrophic association in a well-characterized two-species microbial system, assess the level of sub-optimal growth in phototrophic microbial mats, and elucidate the extent and direction of inter-species metabolite and electron transfer in a model microbial community. We also used OptCom to examine addition of a new member to an existing community. Our study demonstrates the importance of trade-offs between species- and community-level fitness driving forces and lays the foundation for metabolic-driven analysis of various types of interactions in multi-species microbial systems using genome-scale metabolic models. PMID:22319433

  11. Performance Comparison Between Lqr and Pid Controllers for AN Inverted Pendulum System

    NASA Astrophysics Data System (ADS)

    Nasir, A. N. K.; Ahmad, M. A.; Rahmat, M. F.

    2008-10-01

    The objective of this paper is to compare the time specification performance between two conventional controllers for an inverted pendulum system. The goal is to determine which control strategy delivers better performance with respect to pendulum's angle and cart's position. The inverted pendulum represents a challenging control problem, which continually moves toward an uncontrolled state. Two controllers are presented such as Linear-Quadratic-Regulator (LQR) and Proportional-Integral-Derivatives (PID) controllers for controlling the linearized system of inverted pendulum model. Simulation study has been done in Matlab simulink environment shows that both controllers are capable to control multi output inverted pendulum system successfully. The result shows that LQR produced better response compared to PID control strategies and is presented in time domain.

  12. Using hidden multi-state Markov models with multi-parameter volcanic data to provide empirical evidence for alert level decision-support

    NASA Astrophysics Data System (ADS)

    Aspinall, W. P.; Carniel, R.; Jaquet, O.; Woo, G.; Hincks, T.

    2006-05-01

    For the purposes of eruption forecasting and hazard mitigation, a volcanic crisis may be represented as a staged progression of states of unrest, each with its own timescale and likelihood of transition to other states (or to climactic eruption). If the state conditions can be interpreted physically, e.g., in terms of advancing materials failure, this knowledge could be used directly to inform decisions on alert level setting. A multi-state Markov process provides one simple model for defining states and for estimating rates of switching between states. However, for eruptive processes, such states are not directly observable and must be inferred from latent markers, such as seismic activity, gas output, deformation rates, etc., some of which may be contradictory. Interpretations of uncertain data will be liable to error, so a model is needed which can simultaneously estimate both elements: the transition likelihood of a hidden process and the probabilities of state misclassification. We describe the concept and underlying principles of continuous-time hidden Markov models and demonstrate them in a decision-support context with a preliminary working implementation using MULTIMO data. Where multi-parameter streams of raw, processed or conditioned data of different kinds are available, these can be input in near real-time to appropriate hidden multi-state Markov models, the outputs of each providing their own objective analyses of eruptive state in probabilistic terms. These separate, multiple indicators of state can then be input into a Bayesian Belief Network framework for weighing and combining them as different strands of evidence, together with other observations, data, interpretations and expert judgment.

  13. Development and applications of a multi-level strain energy method for detecting finite element modeling errors

    NASA Technical Reports Server (NTRS)

    Hashemi-Kia, Mostafa; Kilroy, Kevin L.; Parker, G.

    1990-01-01

    A computational procedure is described which can be used efficiently in identifying modeling errors which may arise from development of a structural finite element model. The procedure, which is referred to as the multi-level strain energy check, is set up in the form of a set of NASTRAN DMAP alters which provide sufficient information about the modeling errors at G-Set, N-Set, and F-Set levels. This technique was applied to two NASTRAN models, namely, the AH-64A and AH-1G models. Two modeling errors were identified for the AH-1G, which were then corrected.

  14. High spatial resolution water level time series in the Florida Everglades wetlands using multi-track ALOS PALSAR data

    NASA Astrophysics Data System (ADS)

    Hong, S.; Wdowinski, S.

    2013-05-01

    Wetland InSAR (Interferometric Synthetic Aperture Radar) observations provide very high-resolution maps of water level changes that cannot be obtained by any terrestrial technique. We recently developed the Small Temporal Baseline Subset (STBAS) approach, which combines single-track InSAR and stage (water level) observations to generate high-resolution absolute water level time series maps. However, the temporal resolution of produced time series is coarse compared with in-situ stage observation and, hence, the usefulness of these maps is rather limited. To compensate for the low temporal resolution weakness of space-based water level time series, we propose using a multi-track STBAS technique, which utilizes all available Synthetic Aperture Radar (SAR) observations acquired over a certain wetland area. We use a four-year long L-band ALOS PALSAR dataset acquired during 2007-2011 to test the proposed method over the Water Conservation Area 1 (WCA1) in the Everglades wetlands, south Florida (USA). A total of 37 images acquired with four tracks were collected. Daily water level data at 12 stage stations, which are monitored by the Everglades Depth Estimation Network (EDEN) in WCA1 area, were used to calibrate the InSAR-derived water level data. The proposed multi-track approach yielded a significant improvement of temporal resolution, which is dependent on the SAR satellite revisit cycle. Instead of the 46-day repeat orbit of ALOS, the multi-track method produces water level maps with temporal resolution of only 7 days. A quality control analysis of the methods indicates that the average root mean square error (RMSE) of the differences between stage water level and retrieved water level by InSAR technique is 4.0 cm. The end products of absolute water level time series with improved temporal and very high spatial resolutions can be used as excellent constraints for high-resolution wetland flow models. Furthermore, the next generation of SAR satellites has been designed with shorter revisit cycles, which will provide temporally denser maps of water level changes. Fig. 1. Comparison between stage (solid line) and InSAR (circle: 148 track, cross: 149 track, diamond: 464 track and square: 465 track) determined water level time series.

  15. Simulations of magnetic reconnection with Parsek2D-MLMD, a new Multi Level Multi Domain (MLMD) Implicit Moment Method (IMM) Particle in Cell (PIC) code

    NASA Astrophysics Data System (ADS)

    Innocenti, M.; Beck, A.; Lapenta, G.; Markidis, S.

    2012-12-01

    The kinetic simulation of intrinsically multi scale processes such as magnetic reconnection events with realistic mass ratios is a daunting task for explicit Particle In Cell (PIC) codes, which require to use resolutions of the order of the electron Debye length even when simulating dramatically bigger domains. As an example, a simulation of reconnection in the magnetotail, with domain sizes of the order of 20 di x 10 di ( 7.2 106 m x 3.6 106 m, with di being the ion skin depth) and a resolution of ?D,e= 687 m, with ?D,e the electron Debye length, requires the astounding number of 10500 x 5240 cells. Higher grid spacings can be used if the simulation is performed with an implicit PIC code, which substitutes a much less strict accuracy constraint to the stability constraint of explicit PIC codes. The same reconnection problem as before can be simulated, with an implicit PIC code resolving the scale of interest of de /2 instead of the electron Debye length (de is the electron skin depth), with the much more manageable number of 1920 x 958 cells. However, an even smaller number of cells can be used if, instead of using the same, high resolution on the entire domain, the domain to simulate is divided into subdomains each resolved with a grid spacing related to the physical scale of interest in the specific subdomain. In the case of reconnection, the division which immediately springs to mind is between electron diffusion region, ion diffusion region and outer region, where resolutions respectively of the order of fractions of the electron skin depth, of the ion skin depth and bigger can be used. We present here a new Multi Level Multi Domain (MLMD) Implicit Moment Method (IMM) Particle In Cell (PIC) code, Parsek2D-MLMD, able to perform simulations of magnetic reconnection where the expensive high resolutions are used only when needed, while the rest of the domain is simulated with grid spacings chosen according to the local scales of interest. The major difference between the MLMD method we present and the already existing Adaptive Mesh Refinement (AMR) methods (apart for the use of an implicit algorithm, to the authors' knowledge never employed before in PIC AMR methods) is the fact that all levels are fully simulated in fields and particles, while most of the existing AMR methods simulate particles only at the most refined levels. This simplifies the treatment of particles at the interface between the levels, an operation particularly delicate in presence of the strong localized currents that develop during reconnection. The interlocking of the levels simulated at different resolution is guaranteed through the interpolation of boundary conditions from the coarse to the refined levels, the projection of the refined fields from the refined to the coarse levels and the generation of the particles at the boundaries of the refined levels from the corresponding particle distribution at the coarse levels. Test simulations of reconnection events across the interlocked grids in 2D will be presented, together with performance considerations.

  16. Institutional Disparities in the Cost Effectiveness of GCE A-Level Provision: A Multi-Level Approach.

    ERIC Educational Resources Information Center

    Fielding, A.

    1995-01-01

    Reanalyzes H. Thomas's 1980s data, which used teaching group as the unit of analysis and illuminated some institutional disparities in provision of General Certificate of Education (GCE) A-levels. Uses multilevel analysis to focus on individual students in a hierarchical framework. Among the study institutions, school sixth forms appear less…

  17. Multi-level factors affecting entry into and engagement in the HIV continuum of care in Iringa, Tanzania.

    PubMed

    Layer, Erica H; Kennedy, Caitlin E; Beckham, Sarah W; Mbwambo, Jessie K; Likindikoki, Samuel; Davis, Wendy W; Kerrigan, Deanna L; Brahmbhatt, Heena

    2014-01-01

    Progression through the HIV continuum of care, from HIV testing to lifelong retention in antiretroviral therapy (ART) care and treatment programs, is critical to the success of HIV treatment and prevention efforts. However, significant losses occur at each stage of the continuum and little is known about contextual factors contributing to disengagement at these stages. This study sought to explore multi-level barriers and facilitators influencing entry into and engagement in the continuum of care in Iringa, Tanzania. We used a mixed-methods study design including facility-based assessments and interviews with providers and clients of HIV testing and treatment services; interviews, focus group discussions and observations with community-based providers and clients of HIV care and support services; and longitudinal interviews with men and women living with HIV to understand their trajectories in care. Data were analyzed using narrative analysis to identify key themes across levels and stages in the continuum of care. Participants identified multiple compounding barriers to progression through the continuum of care at the individual, facility, community and structural levels. Key barriers included the reluctance to engage in HIV services while healthy, rigid clinic policies, disrespectful treatment from service providers, stock-outs of supplies, stigma and discrimination, alternate healing systems, distance to health facilities and poverty. Social support from family, friends or support groups, home-based care providers, income generating opportunities and community mobilization activities facilitated engagement throughout the HIV continuum. Findings highlight the complex, multi-dimensional dynamics that individuals experience throughout the continuum of care and underscore the importance of a holistic and multi-level perspective to understand this process. Addressing barriers at each level is important to promoting increased engagement throughout the continuum. PMID:25119665

  18. Multi-Level Factors Affecting Entry into and Engagement in the HIV Continuum of Care in Iringa, Tanzania

    PubMed Central

    Layer, Erica H.; Kennedy, Caitlin E.; Beckham, Sarah W.; Mbwambo, Jessie K.; Likindikoki, Samuel; Davis, Wendy W.; Kerrigan, Deanna L.; Brahmbhatt, Heena

    2014-01-01

    Progression through the HIV continuum of care, from HIV testing to lifelong retention in antiretroviral therapy (ART) care and treatment programs, is critical to the success of HIV treatment and prevention efforts. However, significant losses occur at each stage of the continuum and little is known about contextual factors contributing to disengagement at these stages. This study sought to explore multi-level barriers and facilitators influencing entry into and engagement in the continuum of care in Iringa, Tanzania. We used a mixed-methods study design including facility-based assessments and interviews with providers and clients of HIV testing and treatment services; interviews, focus group discussions and observations with community-based providers and clients of HIV care and support services; and longitudinal interviews with men and women living with HIV to understand their trajectories in care. Data were analyzed using narrative analysis to identify key themes across levels and stages in the continuum of care. Participants identified multiple compounding barriers to progression through the continuum of care at the individual, facility, community and structural levels. Key barriers included the reluctance to engage in HIV services while healthy, rigid clinic policies, disrespectful treatment from service providers, stock-outs of supplies, stigma and discrimination, alternate healing systems, distance to health facilities and poverty. Social support from family, friends or support groups, home-based care providers, income generating opportunities and community mobilization activities facilitated engagement throughout the HIV continuum. Findings highlight the complex, multi-dimensional dynamics that individuals experience throughout the continuum of care and underscore the importance of a holistic and multi-level perspective to understand this process. Addressing barriers at each level is important to promoting increased engagement throughout the continuum. PMID:25119665

  19. A multi-level system quality improvement intervention to reduce racial disparities in hypertension care and control: study protocol

    PubMed Central

    2013-01-01

    Background Racial disparities in blood pressure control have been well documented in the United States. Research suggests that many factors contribute to this disparity, including barriers to care at patient, clinician, healthcare system, and community levels. To date, few interventions aimed at reducing hypertension disparities have addressed factors at all of these levels. This paper describes the design of Project ReD CHiP (Reducing Disparities and Controlling Hypertension in Primary Care), a multi-level system quality improvement project. By intervening on multiple levels, this project aims to reduce disparities in blood pressure control and improve guideline concordant hypertension care. Methods Using a pragmatic trial design, we are implementing three complementary multi-level interventions designed to improve blood pressure measurement, provide patient care management services and offer expanded provider education resources in six primary care clinics in Baltimore, Maryland. We are staggering the introduction of the interventions and will use Statistical Process Control (SPC) charting to determine if there are changes in outcomes at each clinic after implementation of each intervention. The main hypothesis is that each intervention will have an additive effect on improvements in guideline concordant care and reductions in hypertension disparities, but the combination of all three interventions will result in the greatest impact, followed by blood pressure measurement with care management support, blood pressure measurement with provider education, and blood pressure measurement only. This study also examines how organizational functioning and cultural competence affect the success of the interventions. Discussion As a quality improvement project, Project ReD CHiP employs a novel study design that specifically targets multi-level factors known to contribute to hypertension disparities. To facilitate its implementation and improve its sustainability, we have incorporated stakeholder input and tailored components of the interventions to meet the specific needs of the involved clinics and communities. Results from this study will provide knowledge about how integrated multi-level interventions can improve hypertension care and reduce disparities. Trial Registration ClinicalTrials.gov NCT01566864 PMID:23734703

  20. A public health framework to translate risk factors related to political violence and war into multi-level preventive interventions.

    PubMed

    De Jong, Joop T V M

    2010-01-01

    Political violence, armed conflicts and human rights violations are produced by a variety of political, economic and socio-cultural factors. Conflicts can be analyzed with an interdisciplinary approach to obtain a global understanding of the relative contribution of risk and protective factors. A public health framework was designed to address these risk factors and protective factors. The framework resulted in a matrix that combined primary, secondary and tertiary interventions with their implementation on the levels of the society-at-large, the community, and the family and individual. Subsequently, the risk and protective factors were translated into multi-sectoral, multi-modal and multi-level preventive interventions involving the economy, governance, diplomacy, the military, human rights, agriculture, health, and education. Then the interventions were slotted in their appropriate place in the matrix. The interventions can be applied in an integrative form by international agencies, governments and non-governmental organizations, and molded to meet the requirements of the historic, political-economic and socio-cultural context. The framework maps the complementary fit among the different actors while engaging themselves in preventive, rehabilitative and reconstructive interventions. The framework shows how the economic, diplomatic, political, criminal justice, human rights, military, health and rural development sectors can collaborate to promote peace or prevent the aggravation or continuation of violence. A deeper understanding of the association between risk and protective factors and the developmental pathways of generic, country-specific and culture-specific factors leading to political violence is needed. PMID:19883967

  1. Microgrid and Inverter Control and Simulator Software

    Energy Science and Technology Software Center (ESTSC)

    2012-09-13

    A collection of software that can simulate the operation of an inverter on a microgrid or control a real inverter. In addition, it can simulate the control of multiple nodes on a microgrid." Application: Simulation of inverters and microgrids; control of inverters on microgrids." The MMI submodule is designed to control custom inverter hardware, and to simulate that hardware. The INVERTER submodule is only the simulator code, and is of an earlier generation than themore » simulator in MMI. The MICROGRID submodule is an agent-based simulator of multiple nodes on a microgrid which presents a web interface. The WIND submodule produces movies of wind data with a web interface.« less

  2. System and method for regulating resonant inverters

    DOEpatents

    Stevanovic, Ljubisa Dragoljub (Clifton Park, NY); Zane, Regan Andrew (Superior, CO)

    2007-08-28

    A technique is provided for direct digital phase control of resonant inverters based on sensing of one or more parameters of the resonant inverter. The resonant inverter control system includes a switching circuit for applying power signals to the resonant inverter and a sensor for sensing one or more parameters of the resonant inverter. The one or more parameters are representative of a phase angle. The resonant inverter control system also includes a comparator for comparing the one or more parameters to a reference value and a digital controller for determining timing of the one or more parameters and for regulating operation of the switching circuit based upon the timing of the one or more parameters.

  3. DNA rearrangement mediated by inverted repeats.

    PubMed Central

    Bi, X; Liu, L F

    1996-01-01

    Inverted repeats of DNA are widespread in the genomes of eukaryotes and prokaryotes and can mediate genome rearrangement. We studied rearrangement mediated by plasmid-borne inverted repeats in Escherichia coli. We show that inverted repeats can mediate an efficient and recA-independent recombination event. Surprisingly, the product of this recombination is not that of simple inversion between the inverted repeats, but almost exclusively an unusual head-to-head dimer with complex DNA rearrangement. Moreover, this recombination is dramatically reduced by increasing the distance separating the repeats. These results can be readily explained by a model involving reciprocal switching of the leading and lagging strands of DNA replication within the inverted repeats, which leads to the formation of a Holliday junction. Reciprocal strand switching during DNA replication might be a common mechanism for genome rearrangement associated with inverted duplication. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:8570641

  4. An empirical study of statistical properties of variance partition coefficients for multi-level logistic regression models

    USGS Publications Warehouse

    Li, J.; Gray, B.R.; Bates, D.M.

    2008-01-01

    Partitioning the variance of a response by design levels is challenging for binomial and other discrete outcomes. Goldstein (2003) proposed four definitions for variance partitioning coefficients (VPC) under a two-level logistic regression model. In this study, we explicitly derived formulae for multi-level logistic regression model and subsequently studied the distributional properties of the calculated VPCs. Using simulations and a vegetation dataset, we demonstrated associations between different VPC definitions, the importance of methods for estimating VPCs (by comparing VPC obtained using Laplace and penalized quasilikehood methods), and bivariate dependence between VPCs calculated at different levels. Such an empirical study lends an immediate support to wider applications of VPC in scientific data analysis.

  5. Integration of multi-level biomarker responses to cadmium and benzo[k]fluoranthene in the pale chub (Zacco platypus).

    PubMed

    Kim, Woo-Keun; Lee, Sung-Kyu; Park, June-Woo; Choi, Kyungho; Cargo, Jordan; Schlenk, Daniel; Jung, Jinho

    2014-12-01

    The Cd exposure for 14 days significantly increased both the molecular (DNA single-strand breaks) and biochemical (metallothionein concentrations) biomarkers in the freshwater pale chub, Zacco platypus, whereas changes in the histological and physiological biomarker responses were negligible. The BkF exposure for 14 days led to significant increases in the mRNA expression of catalase and superoxide dismutase, 7-ethoxyresorufin-O-deethylase enzymatic activity and DNA single-strand breakage at the molecular and biochemical levels. In addition, exposure to 50?g/L of BkF induced histological alteration in the liver, with significant changes to the liver somatic index and condition factor at the physiological level. The integration of multi-level biomarker responses at the molecular, biochemical and physiological levels was highly correlated with the concentrations of Cd and BkF. PMID:25217733

  6. Hollow optical-fiber based infrared spectroscopy for measurement of blood glucose level by using multi-reflection prism.

    PubMed

    Kino, Saiko; Omori, Suguru; Katagiri, Takashi; Matsuura, Yuji

    2016-02-01

    A mid-infrared attenuated total reflection (ATR) spectroscopy system employing hollow optical fibers and a trapezoidal multi-reflection ATR prism has been developed to measure blood glucose levels. Using a multi-reflection prism brought about higher sensitivity, and the flat and wide contact surface of the prism resulted in higher measurement reproducibility. An analysis of in vivo measurements of human inner lip mucosa revealed clear signatures of glucose in the difference spectra between ones taken during the fasting state and ones taken after ingestion of glucose solutions. A calibration plot based on the absorption peak at 1155 cm(-1) that originates from the pyranose ring structure of glucose gave measurement errors less than 20%. PMID:26977373

  7. Hollow optical-fiber based infrared spectroscopy for measurement of blood glucose level by using multi-reflection prism

    PubMed Central

    Kino, Saiko; Omori, Suguru; Katagiri, Takashi; Matsuura, Yuji

    2016-01-01

    A mid-infrared attenuated total reflection (ATR) spectroscopy system employing hollow optical fibers and a trapezoidal multi-reflection ATR prism has been developed to measure blood glucose levels. Using a multi-reflection prism brought about higher sensitivity, and the flat and wide contact surface of the prism resulted in higher measurement reproducibility. An analysis of in vivo measurements of human inner lip mucosa revealed clear signatures of glucose in the difference spectra between ones taken during the fasting state and ones taken after ingestion of glucose solutions. A calibration plot based on the absorption peak at 1155 cm−1 that originates from the pyranose ring structure of glucose gave measurement errors less than 20%. PMID:26977373

  8. A novel alignment mechanism employing orthogonal connected multi-layered flexible hinges for both leveling and centering.

    PubMed

    Zhao, Jian; Wang, Hongxi; Gao, Renjing; Hu, Ping; Yang, Yintang

    2012-06-01

    To eliminate the effects of motion coupling for measuring cylindrical work pieces, a novel alignment mechanism integrating functions of both leveling and centering is designed and fabricated by introducing multi-layered orthogonal connected flexible hinges as the key supporting and joining elements. Different from traditional leveling mechanisms with many separate parts fabricated together, all of the flexible hinges were integrated in one three-dimensioned machining part without assembling process, and thus synchronously simplifying the structure and reducing assembly errors. Based on the screw theory, the mathematic model of the proposed alignment mechanism is established for any resolution requirements depending on screw characteristics. A millimeter-sized device is fabricated with the alignment precision of 1.0 ?m for centering within the range of 1 mm and 1 in. for leveling within 1. The experiment results are in very close agreement to those obtained by simulation, which validate the feasibility of introducing multi-layered orthogonal flexible hinges in the centering and leveling mechanisms. PMID:22755657

  9. A Multi-Level Bayesian Analysis of Racial Bias in Police Shootings at the County-Level in the United States, 2011–2014

    PubMed Central

    Ross, Cody T.

    2015-01-01

    A geographically-resolved, multi-level Bayesian model is used to analyze the data presented in the U.S. Police-Shooting Database (USPSD) in order to investigate the extent of racial bias in the shooting of American civilians by police officers in recent years. In contrast to previous work that relied on the FBI’s Supplemental Homicide Reports that were constructed from self-reported cases of police-involved homicide, this data set is less likely to be biased by police reporting practices. County-specific relative risk outcomes of being shot by police are estimated as a function of the interaction of: 1) whether suspects/civilians were armed or unarmed, and 2) the race/ethnicity of the suspects/civilians. The results provide evidence of a significant bias in the killing of unarmed black Americans relative to unarmed white Americans, in that the probability of being {black, unarmed, and shot by police} is about 3.49 times the probability of being {white, unarmed, and shot by police} on average. Furthermore, the results of multi-level modeling show that there exists significant heterogeneity across counties in the extent of racial bias in police shootings, with some counties showing relative risk ratios of 20 to 1 or more. Finally, analysis of police shooting data as a function of county-level predictors suggests that racial bias in police shootings is most likely to emerge in police departments in larger metropolitan counties with low median incomes and a sizable portion of black residents, especially when there is high financial inequality in that county. There is no relationship between county-level racial bias in police shootings and crime rates (even race-specific crime rates), meaning that the racial bias observed in police shootings in this data set is not explainable as a response to local-level crime rates. PMID:26540108

  10. A Single-Phase Embedded Z-Source DC-AC Inverter

    PubMed Central

    Kim, Se-Jin; Lim, Young-Cheol

    2014-01-01

    In the conventional DC-AC inverter consisting of two DC-DC converters with unipolar output capacitors, the output capacitor voltages of the DC-DC converters must be higher than the DC input voltage. To overcome this weakness, this paper proposes a single-phase DC-AC inverter consisting of two embedded Z-source converters with bipolar output capacitors. The proposed inverter is composed of two embedded Z-source converters with a common DC source and output AC load. Though the output capacitor voltages of the converters are relatively low compared to those of a conventional inverter, an equivalent level of AC output voltages can be obtained. Moreover, by controlling the output capacitor voltages asymmetrically, the AC output voltage of the proposed inverter can be higher than the DC input voltage. To verify the validity of the proposed inverter, experiments were performed with a DC source voltage of 38?V. By controlling the output capacitor voltages of the converters symmetrically or asymmetrically, the proposed inverter can produce sinusoidal AC output voltages. The experiments show that efficiencies of up to 95% and 97% can be achieved with the proposed inverter using symmetric and asymmetric control, respectively. PMID:25133241

  11. A single-phase embedded Z-source DC-AC inverter.

    PubMed

    Kim, Se-Jin; Lim, Young-Cheol

    2014-01-01

    In the conventional DC-AC inverter consisting of two DC-DC converters with unipolar output capacitors, the output capacitor voltages of the DC-DC converters must be higher than the DC input voltage. To overcome this weakness, this paper proposes a single-phase DC-AC inverter consisting of two embedded Z-source converters with bipolar output capacitors. The proposed inverter is composed of two embedded Z-source converters with a common DC source and output AC load. Though the output capacitor voltages of the converters are relatively low compared to those of a conventional inverter, an equivalent level of AC output voltages can be obtained. Moreover, by controlling the output capacitor voltages asymmetrically, the AC output voltage of the proposed inverter can be higher than the DC input voltage. To verify the validity of the proposed inverter, experiments were performed with a DC source voltage of 38 V. By controlling the output capacitor voltages of the converters symmetrically or asymmetrically, the proposed inverter can produce sinusoidal AC output voltages. The experiments show that efficiencies of up to 95% and 97% can be achieved with the proposed inverter using symmetric and asymmetric control, respectively. PMID:25133241

  12. Continuum Level Formulation and Implementation of a Multi-scale Model for Vanadium

    SciTech Connect

    Lawrence Livermore National Laboratory

    2009-08-17

    A multi-scale approach is used to construct a continuum strength model for vanadium. The model is formulated assuming plastic deformation by dislocation motion and strain hardening due to dislocation interactions. Dislocation density is adopted as the state variable in the model. Information from molecular statics, molecular dynamics and dislocation dynamics simulations is combined to create kinetic relations for dislocation motion, strain hardening relations and evolution equations for the dislocation density. Implicit time integration of the constitutive equations is described in the context of implementation in a finite element code. Results are provided illustrating the strain, strain rate, temperature and pressure dependence of the constitutive model.

  13. Multi-party quantum private comparison protocol with n -level entangled states

    NASA Astrophysics Data System (ADS)

    Wang, Qing-Le; Sun, Hong-Xiang; Huang, Wei

    2014-06-01

    In this paper, two multi-party quantum private comparison (MQPC) protocols are proposed in distributed mode and traveling mode, respectively. Compared with the first MQPC protocol, which pays attention to compare between arbitrary two participants, our protocols focus on the comparison of equality for n participants with a more reasonable assumption of the third party. Through executing our protocols once, it is easy to get if n participants' secrets are same or not. In addition, our protocols are proved to be secure against the attacks from both outside attackers and dishonest participants.

  14. The chromospheric Ca II and Mg II radiative losses in late-type stars: a computational comparison between two-level and multi-level atomic models

    NASA Astrophysics Data System (ADS)

    Fawzy, Diaa E.

    2015-06-01

    In the current study we present radiation correction factors to compute the radiative losses by Mg II and Ca II ions during the process of constructing theoretical models for the chromospheres in late-type stars (spectral type in the range F5V-K8V). We combine the two-level atom approach with the multi-level atom method to accurately compute the radiation correction factors. The procedure is fast and reasonably accurate to be implemented in the time-dependent computations. In the current computations we implement what is called pseudo-partial frequency redistribution and the time-dependent ionization in regard to hydrogen. The radiative correction factors for Mg II show very slight variation for the different spectral types with average value of 1.5. The values we obtained for Ca II show very strong dependence on spectral types and the basic parameters, with values range between 5.58 to 4.22 for F5V and K8V spectral types, respectively. The obtained results accelerate the process of constructing theoretical model chromospheres based on mechanical heating by monochromatic and wave spectra. The current study is an initial step in establishing hybrid multi-dimensional models of stellar chromospheres.

  15. Inverted OLEDs for flexible displays

    NASA Astrophysics Data System (ADS)

    Kim, Jang-Joo; Lee, Jeong-Hwan; Kim, Ji Whan; Kim, Sei-Yong; Yoo, Seung-Jun; Wang, Po-Sheng; Wu, Chih-I.

    2012-09-01

    We reported a couple of methods to improve electron injection from the ITO electrode, thereby to fabricate efficient inverted bottom emission organic light emitting diodes (IBOLEDs). The first method is to use an n-doped electron transporting layer (ETL) as the electron injection layer. Electron only device characteristics and UPS measurements confirmed that B3PYMPM homo-junction has the lowest injection barrier at the interface among three different ETLs, resulting in the highest maximum EQE of 19.8% at low voltage in IBOLEDs. The energy barrier between n-ETL and ETL is one of the most important factors for high performance inverted OLEDs. The second method is to use an organic p-n junction as an electron injection layer, where the p-n junction generated electrons and holes under reverse bias, which corresponds to the forward bias in the OLEDs. The organic p-n junction composed of a p-CuPc/n-Bphen layer shows almost the same electron injection characteristics for the cathodes with different work functions whereas the injection characteristics of the n-Bphen EIL significantly depend on the work function of the cathode. These facts indicate that the organic p-n junction can be efficiently applied as an electron injection layer for high performance flexible organic electronics, regardless of the electrodes.

  16. Multi-scale environmental accounting: methodological lessons from the application of NAMEA at sub-national levels.

    PubMed

    Dalmazzone, Silvana; La Notte, Alessandra

    2013-11-30

    Extending the application of integrated environmental and economic accounts from the national to the local level of government serves several purposes. They can be used not only as an instrument for communicating on the state of the environment and reporting the results of policies, but also as an operational tool - for setting the objectives and designing policies - if made available to the local authorities who have responsibility over the administration of natural resources, land use and conservation policies. The aim of the paper is to test the feasibility of applying hybrid flow accounts at the intermediate and local government levels. As an illustration, NAMEA for air emissions and wastes is applied to a Region, a Province and a Municipality, thus covering the three nested levels of local government in Italy. The study identifies the main issues raised by multi-scale environmental accounting and provides an applied discussion of feasible solutions. PMID:24141065

  17. Evaluation of multi-level social learning for sustainable landscapes: perspective of a development initiative in Bergslagen, Sweden.

    PubMed

    Axelsson, Robert; Angelstam, Per; Myhrman, Lennart; Sdbom, Stefan; Ivarsson, Milis; Elbakidze, Marine; Andersson, Kenneth; Cupa, Petr; Diry, Christian; Doyon, Frederic; Drotz, Marcus K; Hjorth, Arne; Hermansson, Jan Olof; Kullberg, Thomas; Lickers, F Henry; McTaggart, Johanna; Olsson, Anders; Pautov, Yurij; Svensson, Lennart; Trnblom, Johan

    2013-03-01

    To implement policies about sustainable landscapes and rural development necessitates social learning about states and trends of sustainability indicators, norms that define sustainability, and adaptive multi-level governance. We evaluate the extent to which social learning at multiple governance levels for sustainable landscapes occur in 18 local development initiatives in the network of Sustainable Bergslagen in Sweden. We mapped activities over time, and interviewed key actors in the network about social learning. While activities resulted in exchange of experiences and some local solutions, a major challenge was to secure systematic social learning and make new knowledge explicit at multiple levels. None of the development initiatives used a systematic approach to secure social learning, and sustainability assessments were not made systematically. We discuss how social learning can be improved, and how a learning network of development initiatives could be realized. PMID:23475659

  18. Perturbational treatment of spin-orbit coupling for generally applicable high-level multi-reference methods

    SciTech Connect

    Mai, Sebastian; Marquetand, Philipp; Gonzlez, Leticia; Mller, Thomas; Plasser, Felix; Lischka, Hans

    2014-08-21

    An efficient perturbational treatment of spin-orbit coupling within the framework of high-level multi-reference techniques has been implemented in the most recent version of the COLUMBUS quantum chemistry package, extending the existing fully variational two-component (2c) multi-reference configuration interaction singles and doubles (MRCISD) method. The proposed scheme follows related implementations of quasi-degenerate perturbation theory (QDPT) model space techniques. Our model space is built either from uncontracted, large-scale scalar relativistic MRCISD wavefunctions or based on the scalar-relativistic solutions of the linear-response-theory-based multi-configurational averaged quadratic coupled cluster method (LRT-MRAQCC). The latter approach allows for a consistent, approximatively size-consistent and size-extensive treatment of spin-orbit coupling. The approach is described in detail and compared to a number of related techniques. The inherent accuracy of the QDPT approach is validated by comparing cuts of the potential energy surfaces of acrolein and its S, Se, and Te analoga with the corresponding data obtained from matching fully variational spin-orbit MRCISD calculations. The conceptual availability of approximate analytic gradients with respect to geometrical displacements is an attractive feature of the 2c-QDPT-MRCISD and 2c-QDPT-LRT-MRAQCC methods for structure optimization and ab inito molecular dynamics simulations.

  19. Why we need multi-level health workforce governance: Case studies from nursing and medicine in Germany.

    PubMed

    Kuhlmann, Ellen; Larsen, Christa

    2015-12-01

    Health workforce needs have moved up on the reform agendas, but policymaking often remains 'piece-meal work' and does not respond to the complexity of health workforce challenges. This article argues for innovation in healthcare governance as a key to greater sustainability of health human resources. The aim is to develop a multi-level approach that helps to identify gaps in governance and improve policy interventions. Pilot research into nursing and medicine in Germany, carried out between 2013 and 2015 using a qualitative methodology, serves to illustrate systems-based governance weaknesses. Three explorative cases address major responses to health workforce shortages, comprising migration/mobility of nurses, reform of nursing education, and gender-sensitive work management of hospital doctors. The findings illustrate a lack of connections between transnational/EU and organizational governance, between national and local levels, occupational and sector governance, and organizations/hospital management and professional development. Consequently, innovations in the health workforce need a multi-level governance approach to get transformative potential and help closing the existing gaps in governance. PMID:26321192

  20. Testing Interventions to Motivate and Educate (TIME): A multi-level intervention to improve colorectal cancer screening☆

    PubMed Central

    Krok-Schoen, Jessica L.; Young, Gregory S.; Pennell, Michael L.; Reiter, Paul L.; Katz, Mira L.; Post, Douglas M.; Tatum, Cathy M.; Paskett, Electra D.

    2015-01-01

    Objective To test the effectiveness of a colorectal cancer (CRC) screening intervention directed at three levels (clinic, provider, patient) in a primary care setting. Method We conducted a group randomized trial (Clinical Trials registration no. NCT01568151) among 10 primary care clinics in Columbus, Ohio that were randomized to a study condition (intervention or usual care). We determined the effect of a multi-level, stepped behavioral intervention on receipt of a CRC screening test among average-risk patients from these clinics over the study period. Results Patients (n = 527) who were outside of CRC screening recommendations were recruited. Overall, 35.4% of participants in the intervention clinics had received CRC screening by the end of the study compared to 35.1% of participants who were in the usual care clinics. Time to CRC screening was also similar across arms (HR = 0.97, 95% CI = 0.65–1.45). Conclusion The multi-level intervention was not effective in increasing CRC screening among participants who needed a test, perhaps due to low participation of patients in the stepped intervention. Future studies utilizing evidence-based strategies to encourage CRC screening are needed. PMID:26046014

  1. A use case driven object-oriented design methodology for the design of multi-level workflow schemas

    NASA Astrophysics Data System (ADS)

    Chen, Pei-Hung

    Traditional workflow schema design largely involves manual processes. It begins with business-process models and ends with delivering a workflow schema that can be executed by a workflow management system. However, little effort has been made to develop methodological approaches for workflow design [BARE99]. As a consequence, this thesis develops a design methodology which will enable workflow designers to model complex business processes in a simple and straightforward manner and easily generate workflow schemas. Our methodology is a use case based approach to algorithmic multi-level workflow schema generation. It begins with an initial analysis phase to capture requirement specifications, and incorporates workflow technology to support business process modeling that captures business processes as workflow specifications. In the process, we extend the interaction diagram for modeling workflow applications and for integrating business rules. Consequently, the extended interaction diagrams, named workflow based interaction diagrams, can support process-related concepts, including static and dynamic rules, multiple use case scenarios, event scheduling and delay features. We develop automatic conversion algorithms, which enable designers to generate different levels of workflow schemas automatically based on the workflow-based interaction diagrams generated from the use case analysis. The workflow schemas produced can be specified at different designers can further create a multi-level web interface based on these workflow schemas to support state and process defined data views and decision trees simultaneously.

  2. Review of PV Inverter Technology Cost and Performance Projections

    SciTech Connect

    Navigant Consulting Inc.

    2006-01-01

    The National Renewable Energy Laboratory (NREL) has a major responsibility in the implementation of the U.S. Department of Energy's (DOE's) Solar Energy Technologies Program. Sandia National Laboratories (SNL) has a major role in supporting inverter development, characterization, standards, certifications, and verifications. The Solar Energy Technologies Program recently published a Multiyear Technical Plan, which establishes a goal of reducing the Levelized Energy Cost (LEC) for photovoltaic (PV) systems to $0.06/kWh by 2020. The Multiyear Technical Plan estimates that, in order to meet the PV system goal, PV inverter prices will need to decline to $0.25-0.30 Wp by 2020. DOE determined the need to conduct a rigorous review of the PV Program's technical and economic targets, including the target set for PV inverters. NREL requested that Navigant Consulting Inc.(NCI) conduct a review of historical and projected cost and performance improvements for PV inverters, including identification of critical barriers identified and the approaches government might use to address them.

  3. Study of turbulence of Lower Hybrid Drift Instability origin with the Multi Level Multi Domain semi-implicit adaptive PIC method

    NASA Astrophysics Data System (ADS)

    Innocenti, Maria Elena; Beck, Arnaud; Markidis, Stefano; Lapenta, Giovanni

    2015-04-01

    We study turbulence generated by the Lower Hybrid Drift Instability (LHDI [1]) in the terrestrial magnetosphere. The problem is not only of interest per se, but also for the implications it can have for the so-called turbulent reconnection. The LHDI evolution is simulated with the PIC Multi Level Multi Domain code Parsek2D-MLMD [2,3], which simulates different parts of the domain with different spatial and temporal resolutions. This allows to satisfy, at a low computing cost, the two necessary requirements for LHDI turbulence simulations: 1) a large domain, to capture the high wavelength branch of the LHDI and of the secondary kink instability and 2) high resolution, to cover the high wavenumber part of the power spectrum and to capture the wavenumber at which the turbulent cascade ends. The turbulent cascade proceeds seamlessly from the coarse (low resolution) to the refined (high resolution) grid, the only one resolved enough to capture its end, which is studied here and related to wave-particle interaction processes. We also comment upon the role of smoothing (a common technique used in PIC simulations to reduce particle noise, [4]) in simulations of turbulence and on how its effects on power spectra may be easily mistaken, in absence of accurate convergence studies, for the end of the inertial range. [1] P. Gary, Theory of space plasma microinstabilities, Cambridge Atmospheric and Space Science Series, 2005. [2] M. E. Innocenti, G. Lapenta, S. Markidis, A. Beck, A. Vapirev, Journal of Computational Physics 238 (2013) 115 - 140. [3] M. E. Innocenti, A. Beck, T. Ponweiser, S. Markidis, G. Lapenta, Computer Physics Communications (accepted) (2014). [4] C. K. Birdsall, A. B. Langdon, Plasma physics via computer simulation, Taylor and Francis, 2004.

  4. Maxwell consideration of polaritonic quasi-particle Hamiltonians in multi-level systems

    NASA Astrophysics Data System (ADS)

    Richter, Steffen; Michalsky, Tom; Fricke, Lennart; Sturm, Chris; Franke, Helena; Grundmann, Marius; Schmidt-Grund, Rdiger

    2015-12-01

    We address the problem of the correct description of light-matter coupling for excitons and cavity photons in the case of systems with multiple photon modes or excitons, respectively. In the literature, two different approaches for the phenomenological coupling Hamiltonian can be found: Either one single Hamiltonian with a basis whose dimension equals the sum of photonic modes and excitonic resonances is used. Or a set of independent Hamiltonians, one for each photon mode, is chosen. Both are usually used equivalently for the same kind of multi-photonic systems which cannot be correct. However, identifying the suitable Hamiltonian is difficult when modeling experimental data. By means of numerical transfer matrix calculations, we demonstrate the scope of application of each approach: The first one holds only for the coupling of a single photon state to several excitons, while in the case of multiple photon modes, separate Hamiltonians must be used for each photon mode.

  5. Commodity multi-processor systems in the ATLAS level-2 trigger

    SciTech Connect

    Abolins, M.; Blair, R.; Bock, R.; Bogaerts, A.; Dawson, J.; Ermoline, Y.; Hauser, R.; Kugel, A.; Lay, R.; Muller, M.; Noffz, K.-H.; Pope, B.; Schlereth, J.; Werner, P.

    2000-05-23

    Low cost SMP (Symmetric Multi-Processor) systems provide substantial CPU and I/O capacity. These features together with the ease of system integration make them an attractive and cost effective solution for a number of real-time applications in event selection. In ATLAS the authors consider them as intelligent input buffers (active ROB complex), as event flow supervisors or as powerful processing nodes. Measurements of the performance of one off-the-shelf commercial 4-processor PC with two PCI buses, equipped with commercial FPGA based data source cards (microEnable) and running commercial software are presented and mapped on such applications together with a long-term program of work. The SMP systems may be considered as an important building block in future data acquisition systems.

  6. Multi-level kinetic model explaining diverse roles of isozymes in prokaryotes.

    PubMed

    Jablonsky, Jiri; Schwarz, Doreen; Hagemann, Martin

    2014-01-01

    Current standard methods for kinetic and genomic modeling cannot provide deep insight into metabolic regulation. Here, we developed and evaluated a multi-scale kinetic modeling approach applicable to any prokaryote. Specifically, we highlight the primary metabolism of the cyanobacterium Synechococcus elongatus PCC 7942. The model bridges metabolic data sets from cells grown at different CO2 conditions by integrating transcriptomic data and isozymes. Identification of the regulatory roles of isozymes allowed the calculation and explanation of the absolute metabolic concentration of 3-phosphoglycerate. To demonstrate that this method can characterize any isozyme, we determined the function of two glycolytic glyceraldehyde-3-phosphate dehydrogenases: one co-regulates high concentrations of the 3-phosphoglycerate, the other shifts the bifurcation point in hexose regulation, and both improve biomass production. Moreover, the regulatory roles of multiple phosphoglycolate phosphatases were defined for varying (non-steady) CO2 conditions, suggesting their protective role against toxic photorespiratory intermediates. PMID:25127487

  7. Glucose level determination with a multi-enzymatic cascade reaction in a functionalized glass chip.

    PubMed

    Costantini, Francesca; Tiggelaar, Roald; Sennato, Simona; Mura, Francesco; Schlautmann, Stefan; Bordi, Federico; Gardeniers, Han; Manetti, Cesare

    2013-09-01

    In this work we show the functionalization of the interior of microfluidic glass chips with poly(2-hydroxyethyl methacrylate) polymer brushes as anchors for co-immobilization of the enzymes glucose-oxidase and horseradish peroxidase. The formation of the brush layer and subsequent immobilization of these enzymes have been characterized on flat surfaces by atomic force microscopy and Fourier transform infrared spectroscopy, and studied inside glass chips by field emission scanning microscopy. Enzyme-functionalized glass chips have been applied for performing a multi-enzymatic cascade reaction for the fast (20 s) determination of glucose in human blood samples and the result is in excellent agreement with values obtained from the conventional hospital laboratory. The limit of detection of this bi-enzymatic method is 60 μM. With the advantages of high selectivity and reproducibility, this functionalization method can be used for improving the efficiency of glucose sensors. PMID:23831561

  8. Multi-level single mode 2D polymer waveguide optical interconnects using nano-imprint lithography.

    PubMed

    Khan, Muhammad Umar; Justice, John; Petäjä, Jarno; Korhonen, Tia; Boersma, Arjen; Wiegersma, Sjoukje; Karppinen, Mikko; Corbett, Brian

    2015-06-01

    Single and multi-layer passive optical interconnects using single mode polymer waveguides are demonstrated using UV nano-imprint lithography. The fabrication tolerances associated with imprint lithography are investigated and we show a way to experimentally quantify a small variation in index contrast between core and cladding of fabricated devices. 1x2 splitting devices based on directional couplers and multimode interference interferometers are demonstrated to have less than 0.45 dB insertion loss with 0.02 ± 0.01 dB power imbalance between the outputs. We demonstrate an 'optical via' with an insertion loss less than 0.45 dB to transfer light from one optical signal plane to another. A 1x4 two-dimensional optical port is experimentally demonstrated to spatially split the input power with an insertion loss of 1.2 dB. PMID:26072823

  9. High-level Multi-Resistant and Virulent Escherichia coli in Abeokuta, Nigeria.

    PubMed

    Akinduti, Paul Akinniyi; Aboderin, Bukola W; Oloyede, Rasaq; Ogiogwa, Joseph I; Motayo, Babatunde O; Ejilude, Oluwaseun

    2016-01-01

    Multi-resistant Escherichia coli (E. coli) strains co-harboring virulence genes is a cause of high morbidity in Abeokuta, Nigeria. This study was designed to determine some virulent factors among enteropathogenic E. coli in Abeokuta, Nigeria. Approximately non-repetitive 102 isolates of E. coli were recovered from clinical samples from two health facilities in Abeokuta. Biotyping using API and antibiotic susceptibility was determined, and eae and flic genes were assayed by PCR. Antibiotic resistance relatedness was performed by DendroUPGMA. Results showed that 48.0% and 52.0 % were intestinal and extra-intestinal E. coli, ampicillin recorded 100% resistance, amoxycilli/clavulanic acid 64.7%, cotrimoxazole 57.8% and 56.8% resistance against cefotaxime, at MIC >16 ug/mL, 100%, 57.8%, and 50% have MIC50 to ampicillin, tetracycline, and ceftazidime, while 74.5% and 48.0% have MIC90 to ampicillin and ceftazidime. Significant rates of 4.9%, 7.8%, and 9.8% flic, eae, and flic/eae genes were found in intestinal isolates, while 2.9%, 2.0%, and 3.9% were found in extra-intestinal (P < 0.05). Two major clades of the resistant isolates reveal significant antibiotic relatedness among intestinal and extra-intestinal isolates, at 54% resistance similarities with very high multi-antibiotic resistance index of 1.0 (MARI). A high rate of undetected virulent E. coli pathotypes with high resistance could trigger unprecedented morbidity and mortality, mostly among children and the elderly. PMID:26263915

  10. Inverted File Compression through Document Identifier Reassignment.

    ERIC Educational Resources Information Center

    Shieh, Wann-Yun; Chen, Tien-Fu; Shann, Jean Jyh-Jiun; Chung, Chung-Ping

    2003-01-01

    Discusses the use of inverted files in information retrieval systems and proposes a document identifier reassignment method to reduce the average gap values in an inverted file. Highlights include the d-gap technique; document similarity; heuristic algorithms; file compression; and performance evaluation from a simulation environment. (LRW)

  11. Self-oscillating inverter with bipolar transistors

    NASA Astrophysics Data System (ADS)

    Baciu, I.; Cunţan, C. D.; Floruţa, M.

    2016-02-01

    The paper presents a self-oscillating inverter manufactured with bipolar transistors that supplies a high-amplitude alternating voltage to a fluorescent tube with a burned filament. The inverter is supplied from a low voltage accumulator that can be charged from a photovoltaic panel through a voltage regulator.

  12. Multi-level IRT with Measurement Error in the Predictor Variables. Research Report 98-16.

    ERIC Educational Resources Information Center

    Fox, Jean-Paul; Glas, Cees A. W.

    A two-level regression model is imposed on the ability parameters in an item response theory (IRT) model. The advantage of using latent rather than observed scores as dependent variables of a multilevel model is that this offers the possibility of separating the influence of item difficulty and ability level and modeling response variation and

  13. The Multi-Level Classroom or the One Room Little Red School-House Revisited.

    ERIC Educational Resources Information Center

    Courchene, Robert

    1984-01-01

    Describes language lab listening activity designed to serve needs of the English as a second language class comprised of students at different levels of language proficiency, divergent native languages, multicultural backgrounds, and varying levels of formal education. Multilevel tasks are drawn from a common text, allowing students to do

  14. Predictors of Self-Directed Learning for Low-Qualified Employees: A Multi-Level Analysis

    ERIC Educational Resources Information Center

    Raemdonck, Isabel; van der Leeden, Rien; Valcke, Martin; Segers, Mien; Thijssen, Jo

    2012-01-01

    Purpose: This study aims to examine which variables at the level of the individual employee and at the company level are predictors of self-directed learning in low-qualified employees. Methodology: Results were obtained from a sample of 408 low-qualified employees from 35 different companies. The companies were selected from the energy sector,…

  15. Predictors of Self-Directed Learning for Low-Qualified Employees: A Multi-Level Analysis

    ERIC Educational Resources Information Center

    Raemdonck, Isabel; van der Leeden, Rien; Valcke, Martin; Segers, Mien; Thijssen, Jo

    2012-01-01

    Purpose: This study aims to examine which variables at the level of the individual employee and at the company level are predictors of self-directed learning in low-qualified employees. Methodology: Results were obtained from a sample of 408 low-qualified employees from 35 different companies. The companies were selected from the energy sector,

  16. The Multi-Level Classroom or the One Room Little Red School-House Revisited.

    ERIC Educational Resources Information Center

    Courchene, Robert

    1984-01-01

    Describes language lab listening activity designed to serve needs of the English as a second language class comprised of students at different levels of language proficiency, divergent native languages, multicultural backgrounds, and varying levels of formal education. Multilevel tasks are drawn from a common text, allowing students to do…

  17. Practical Loop Transformations for Tensor Contraction Expressions on Multi-Level Memory Hierarchies

    SciTech Connect

    Ma, Wenjing; Krishnamoorthy, Sriram; Agrawal, Gagan

    2011-04-01

    Modern architectures are characterized by deeper levels of memory hierarchy, often explicitly addressable. Optimizing applications for such architectures requires careful management of the data movement across all these levels. In this paper, we focus on the problem of mapping tensor contractions to memory hierarchies with more than two levels, specifically addressing placement of memory allocation and data movement statements, choice of loop fusions, and tile size selection. Existing algorithms to find an integrated solution to this problem even for two-level memory hierarchies has been shown to be expensive. We improve upon this work by focusing on the first-order cost components, simplifying the analysis required and reducing the number of candidates to be evaluated. We have evaluated our framework on a cluster of GPUs. Using five tensor contraction expressions, we show that fusion at multiple levels improves performance, and our framework is effective in determining protable transformations.

  18. Phoenix Scoop Inverted Showing Rasp

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image taken by the Surface Stereo Imager on Sol 49, or the 49th Martian day of the mission (July 14, 2008), shows the silver colored rasp protruding from NASA's Phoenix Mars Lander's Robotic Arm scoop. The scoop is inverted and the rasp is pointing up.

    Shown with its forks pointing toward the ground is the thermal and electrical conductivity probe, at the lower right. The Robotic Arm Camera is pointed toward the ground.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is led by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  19. Coherent coupling and energy transfer enhancement via multi-exciton levels in semiconductor nanocrystals

    NASA Astrophysics Data System (ADS)

    Al-Ahmadi, Ameenah; Ulloa, Sergio

    2008-03-01

    The theory of coherent energy transfer (ET) in nanocrystal (NC) systems [1] is generalized for multiexciton levels. The relevant excitonic states in an isolated NC can be described by an effective four-level system, consisting of the ground level, two degenerate single exciton levels, and the biexciton level. We study the dynamics of a single donor-acceptor pair via the equation of motion for the density matrix of the system and consider analytical limits as well as numerical solutions. We show that the enhancement of the ET efficiency introduced by the biexciton levels is limited due to the coherent coupling of the exciton-biexciton levels in the donor-acceptor pair. The saturation of the ET rate in the donor-acceptor pair suggests a new mechanism to control the dipole-dipole coupling strength in NC systems, and we present here its dependence on structure parameters. [1] A. N. Al-Ahmadi and S. E. Ulloa, Phys. Rev. B 70, 201302(R) (2004).

  20. Nanostructured Inverted Organic Photovoltaic Cells

    NASA Astrophysics Data System (ADS)

    Thomas, Michael

    Organic photovoltaic cells (OPVs)are promising devices for inexpensive power generation from sunlight. Organic semiconductors, the basic materials for OPVs, can be fabricated using a broad range of fabrication technologies from vapor deposition to solution processing. Upon light absorption, a strongly bound exciton is generated which can diffuse to a donor-acceptor heterojunction. At this interface it can be dissociated into free charge carriers which can be collected by the device electrodes. A major challenge for OPVs are short exciton diffusion lengths of up to 20 nm. Morphology engineering is required in order to harvest the exciton before it recombines and improve OPV performance. This work focuses on the study of nanostructured morphologies for use in inverted architecture OPVs. Glancing angle deposition (GLAD)is employed to fabricate nanocolumnar acceptor films. Through combining these nanostructured C60 films with a conjugated polymer donor P3CBT and a small molecule 3-Q, inverted OPVs are fabricated with the goal to analyze effect of morphology engineering on device performance. A major challenge was that C60 were found to be soluble in most commonly used organic solvents such as dichlorobenzene or chloroform. Although this challenge has limited the donor choice and therefore has limited device performance, a significant effect of morphology engineering could be observed. All GLAD structured C60 OPVs outperformed state of the art architectures such as planar films and bulk heterojunctions fabricated with the same materials. For P3CBT in particular the GLAD structured devices exhibited a twofold increase in power conversion efficiency compared with bulk heterojunctions and a fourfold increase compared with planar devices. In a further study, the acceptor materials PTCDA and C60 were co-evaporated into a single film. PTCDA is stable against non-polar organic solvents while C60 provides a high electron mobility. Nanocolumnar acceptor blended PTCDA:C60 films were proven to remain stable when treated with dichlorobenzene. Furthermore, optical and electronic properties of these acceptor blends were investigated.

  1. A new non-overlapping concept to improve the Hybrid Particle Level Set method in multi-phase fluid flows

    NASA Astrophysics Data System (ADS)

    Archer, Philip J.; Bai, Wei

    2015-02-01

    A novel non-overlapping concept is augmented to the Hybrid Particle Level Set (HPLS) method to improve its accuracy and suitability for the modelling of multi-phase fluid flows. The concept addresses shortcomings in the reseeding algorithm, which maintains resolution of the surface at runtime. These shortcomings result in the misplacement of newly seeded particles in the opposite signed domain and necessitate a restriction on the distance that a particle can escape without deletion, which reduces the effectiveness of the method. The non-overlapping concept judges the suitability of potential new particles based on information already contained within the particle representation of the surface. By preventing the misplacement of particles it is possible to significantly relax the distance restriction thereby increasing the accuracy of the HPLS method in multi-phase flows. To demonstrate its robustness and efficiency, the concept is examined with a number of challenging test cases, including both level-set-only simulations and two-phase fluid flows.

  2. Multi-level consistency tests in paleointensity determinations from the welded tuffs of the Aso pyroclastic-flow deposits

    NASA Astrophysics Data System (ADS)

    Mochizuki, Nobutatsu; Maruuchi, Toru; Yamamoto, Yuhji; Shibuya, Hidetoshi

    2013-10-01

    We have performed multi-level consistency tests in an LTD-DHT Shaw paleointensity study on the welded tuffs of the Aso pyroclastic-flow deposits (Aso-1, Aso-2, Aso-3, and Aso-4) in order to obtain reliable mean paleointensities from each unit. For a unit-level consistency test, we collected samples at three or more sites in each unit. To enhance a site-level consistency test, we conducted paleointensity experiments on both whole-rock and glass samples from the same sites. Thermal demagnetization curves of the samples indicate that the main magnetic carrier is titanium-poor titanomagnetite to pure magnetite. Hysteresis parameters are different among the sites of the same units. Also, differences in unblocking spectra and hysteresis parameters are recognized between the whole-rock and glass samples from the same sites. Therefore, these samples of various properties are expected to work effectively for multi-level consistency test. Twenty-nine out of 65 whole-rock samples and 10 out of 31 glass samples gave accepted paleointensity results. At the site-level, consistency of paleointensity estimates is observed with the exception of one site. Two paleointensity estimates from glass samples of a site of Aso-4 are inconsistent and are excluded from further analysis. At the unit-level, consistency or inconsistency among the sites is observed for individual units. For Aso-1, inconsistency in paleointensity estimates among the sites is observed and we can recognize more reliable results from two sites. For Aso-2, consistency in paleointensity estimates from glass and whole-rock samples supports the acceptance of a site. For Aso-3, all paleointensity estimates from two sites are thought to be reliable because consistency between the site-means of the two sites as well as site-level consistency between the glass and whole-rock samples for each site is recognized. For Aso-4, some difference among the sites is observed, but there is no obvious reason to exclude the results of particular sites. Overall, both the site-level and unit-level consistency checks work effectively in these samples which confirm the reliability of the paleointensity estimates or highlights the erroneous ones. On the basis of the reliable paleointensity estimates, unit-mean values are obtained as 24.9 2.2 (1?) ?T (N = 9) for Aso-1, 22.9 1.6 ?T (N = 5) for Aso-2, 28.3 3.4 ?T (N = 10) for Aso-3, and 40.1 6.2 ?T (N = 7) for Aso-4.

  3. Inflammation response at the transcriptional level of HepG2 cells induced by multi-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Piret, Jean-Pascal; Vankoningsloo, Sbastien; Nol, Florence; Mejia Mendoza, Jorge; Lucas, Stphane; Saout, Christelle; Toussaint, Olivier

    2011-07-01

    Poor information are currently available about the biological effects of multi-walled carbon nanotubes (MWCNT) on the liver. In this study, we evaluated the effects of MWCNT at the transcriptional level on the classical in vitro model of HepG2 hepatocarcinoma cells. The expression levels of 96 transcript species implicated in the inflammatory and immune responses was studied after a 24h incubation of HepG2 cells in presence of raw MWCNT dispersed in water by stirring. Among the 46 transcript species detected, only a few transcripts including mRNA coding for interleukine-7, chemokines receptor of the C-C families CCR7, as well as Endothelin-1, were statistically more abundant after treatment with MWCNT. Altogether, these data indicate that MWCNT can only induce a weak inflammatory response in HepG2 cells.

  4. Advances in series resonant inverter technology and its effect on spacecraft employing electric propulsion

    NASA Technical Reports Server (NTRS)

    Robson, R. R.

    1982-01-01

    The efficiency of transistorized Series Resonant Inverters (SRIs), which is higher than that of silicon-controlled rectifier alternatives, reduces spacecraft radiator requirements by 40% and may eliminate the need for heat pipes on 30-cm ion thruster systems. Recently developed 10- and 25-kW inverters have potential applications in gas thrusters, and represent the first spaceborne SRI designs for such power levels. Attention is given to the design and control system approaches employed in these inverter designs to improve efficiency and reduce weight, along with the impact of such improved parameters on electric propulsion systems.

  5. Multi-level magmatic system of El Hierro Island (Canary Islands) constrained by multi-satellite radar interferometry measurements during the 2011-2012 eruption

    NASA Astrophysics Data System (ADS)

    Gonzalez, P. J.; Samsonov, S. V.; Pepe, S.; Tiampo, K. F.; Tizzani, P.; Fernandez, J.; Sansosti, E.

    2012-12-01

    Starting from July 2011, anomalous seismicity was observed at El Hierro Island (Canary Islands, Spain). During the following three months, seismic activity increased both in number of events and in magnitude, while expanding over a large area. In early October 2011 the process led to a submarine eruption, with some uncertainty about the location and timing of vent(s) opening. The site of the eruption was ~10 km from the initial and main earthquake loci, indicative of significant lateral migration. Here, we conduct a multi-frequency, multi-sensor interferometric analysis of space-borne radar images acquired using three different satellites (Radarsat-2, ASAR-ENVISAT and COSMO-SkyMed). Radar interferometry is used to measure the deformation that occurred from December 2009 to July 2012. InSAR data fully captures both the pre-, co- and post-eruptive phases. Subsequently, elastic modeling of the ground deformation is employed to constrain the dynamics associated with the magmatic and eruptive activity. This study represents one of the first geodetically-constrained active magmatic plumbing system model for any of the Canary Islands volcanoes, and one of the few examples of geodetic measurement of submarine volcanic activity to date. It reveals a complex magmatic system with multiple levels of stagnation, a deeper central system (~8.5 km depth) and a shallower magma reservoir at the flank of the southern rift (~4 km depth). Before eruption, magma propagated ~5 km downrift towards the eruption fissure. From mid-November 2011 to early January 2012 the system was continuously recharged from source(s) deeper than 10 km, which contributed to a relatively atypical long duration for a basaltic eruption (~5 months). The submarine eruption finished on early March 2012. However, on June 24, 2012 the seismic activity resumed and intense ground deformation has been recorded. The anomalous seismicity continued for a month depicting a clear, but different migration path with respect to the previous period. At the time of the writing of this abstract (early August 2012), the activity has subsided. The most recently acquired InSAR (Radarsat-2 and COSMO-SkyMed) data will be presented and interpreted. The El Hierro Island magmatic plumbing system is a much more complex system that previously believed. It is composed with at least three main stagnation levels, i) a petrologically-constrained level at 20-26 km depth, ii) a level at the moho, base of the oceanic crust at 8-12 km depth, and iii) a 4 km depth level at the base of the volcanic edifice, coinciding with the typical seafloor depth at El Hierro region. Acknowledgments: Our research was supported by an Ontario Early Researcher Award, the CSRN NSERC Strategic Network Grant, and the NSERC, and the Banting Postdoctoral Fellowship. Additional support was provided by the Spanish MICINN project AYA2010-17448, and the Moncloa Campus of Excellence (UCM-UPM, CSIC). Data was provided by ESA (European Space Agency) through project CAT1:6745; CSA (Canadian Space Agency) by SOAR-E project #28209; and ASI (Italian Space Agency) SAR4Volcanoes project (agreement I/034/11/0).

  6. Improved current control makes inverters the power sources of choice

    SciTech Connect

    Yamamoto, H.; Harada, S.; Ueyama, T.

    1997-02-01

    It is now generally understood that by increasing the operating or switching frequency of a power source the size of the main transformer and main reactor can be shrunk. Thus, a 300-A DC welding power source weighing well under 100 lb can be produced. This makes the inverter power source an ideal choice for applications requiring equipment maneuverability. It is also generally understood that due to higher switching frequencies, a smoother output is obtained from inverter power sources. In the late 1980s, the company developed a new double-inverter power source by which inverted DC weld output is inverted back to AC weld output. This product was the first of its kind in the world. Again, the small compact size of this product was of great interest. Utilizing current waveform control, it was realized that fast response switching from electrode negative to electrode positive could be accurately controlled, offering benefits such as AC GTA welding with high-frequency start only, even at a low welding current. The primary benefit is the ability to limit the electrode positive half cycle to less than 5%. The electrode positive half cycle is responsible for tungsten erosion, which also creates the balling effect of a tungsten electrode. By limiting the electrode positive portion of the AC cycle to a very low level, a rather sharp point can be maintained on the tungsten, which creates a very concentrated, focused arc column. This ability provides excellent joint penetration in fillet welding of aluminum alloys, especially on thick plate. It also reduces the heat-affected zone in AC GTA welding of aluminum.

  7. Fractal multi-level organisation of human groups in a virtual world

    NASA Astrophysics Data System (ADS)

    Fuchs, Benedikt; Sornette, Didier; Thurner, Stefan

    2014-10-01

    Humans are fundamentally social. They form societies which consist of hierarchically layered nested groups of various quality, size, and structure. The anthropologic literature has classified these groups as support cliques, sympathy groups, bands, cognitive groups, tribes, linguistic groups, and so on. Anthropologic data show that, on average, each group consists of approximately three subgroups. However, a general understanding of the structural dependence of groups at different layers is largely missing. We extend these early findings to a very large high-precision large-scale internet-based social network data. We analyse the organisational structure of a complete, multi-relational, large social multiplex network of a human society consisting of about 400,000 odd players of an open-ended massive multiplayer online game for which we know all about their various group memberships at different layers. Remarkably, the online players' society exhibits the same type of structured hierarchical layers as found in hunter-gatherer societies. Our findings suggest that the hierarchical organisation of human society is deeply nested in human psychology.

  8. Retrieval of tea polyphenol at leaf level using spectral transformation and multi-variate statistical approach

    NASA Astrophysics Data System (ADS)

    Dutta, Dibyendu; Das, Prabir Kumar; Bhunia, Uttam Kumar; Singh, Upasana; Singh, Shalini; Sharma, Jaswant Raj; Dadhwal, Vinay Kumar

    2015-04-01

    In the present study, field based hyperspectral data was used to estimate the tea (Camellia sinensis L.) polyphenol at Deha Tea garden of Assam state, India. Leaf reflectance spectra were first filtered for noise and then transformed into normalized and first derivative reflectance for further analysis. Stepwise discriminant analysis was carried out to select sensitive bands for a range of polyphenol concentration by minimizing the effects of other factors such as age of the bushes and management practices. The wavelengths at 358, 369, 484, 845, 916, 1387, 1420, 1435, 1621 and 2294 nm were identified as sensitive to tea polyphenol, among which 2294 nm was found to be the most recurring band. The noise removed selected bands, their transformed derivatives and principal components were regressed with the tea polyphenol using univariate and multi-variate analysis. In univariate analysis the correlation was very poor with RMSE more than 3.0. A significant improvement in R2 values were observed when multivariate analyses like stepwise multiple linear regression (SMLR) and partial least square regression (PLSR) was carried out. The PLSR of first derivative reflectance was most accurate (R2 = 0.81 and RMSE = 1.39 mg g-1) among all the uni- and multivariate analysis for predicting the polyphenol of fresh tea leaves.

  9. Fractal multi-level organisation of human groups in a virtual world

    PubMed Central

    Fuchs, Benedikt; Sornette, Didier; Thurner, Stefan

    2014-01-01

    Humans are fundamentally social. They form societies which consist of hierarchically layered nested groups of various quality, size, and structure. The anthropologic literature has classified these groups as support cliques, sympathy groups, bands, cognitive groups, tribes, linguistic groups, and so on. Anthropologic data show that, on average, each group consists of approximately three subgroups. However, a general understanding of the structural dependence of groups at different layers is largely missing. We extend these early findings to a very large high-precision large-scale internet-based social network data. We analyse the organisational structure of a complete, multi-relational, large social multiplex network of a human society consisting of about 400,000 odd players of an open-ended massive multiplayer online game for which we know all about their various group memberships at different layers. Remarkably, the online players' society exhibits the same type of structured hierarchical layers as found in hunter-gatherer societies. Our findings suggest that the hierarchical organisation of human society is deeply nested in human psychology. PMID:25283998

  10. Factor analysis using mixed models of multi-environment trials with different levels of unbalancing.

    PubMed

    Nuvunga, J J; Oliveira, L A; Pamplona, A K A; Silva, C P; Lima, R R; Balestre, M

    2015-01-01

    This study aimed to analyze the robustness of mixed models for the study of genotype-environment interactions (G x E). Simulated unbalancing of real data was used to determine if the method could predict missing genotypes and select stable genotypes. Data from multi-environment trials containing 55 maize hybrids, collected during the 2005-2006 harvest season, were used in this study. Analyses were performed in two steps: the variance components were estimated by restricted maximum likelihood, using the expectation-maximization (EM) algorithm, and factor analysis (FA) was used to calculate the factor scores and relative position of each genotype in the biplot. Random unbalancing of the data was performed by removing 10, 30, and 50% of the plots; the scores were then re-estimated using the FA model. It was observed that 10, 30, and 50% unbalancing exhibited mean correlation values of 0.7, 0.6, and 0.56, respectively. Overall, the genotypes classified as stable in the biplot had smaller prediction error sum of squares (PRESS) value and prediction amplitude of ellipses. Therefore, our results revealed the applicability of the PRESS statistic to evaluate the performance of stable genotypes in the biplot. This result was confirmed by the sizes of the prediction ellipses, which were smaller for the stable genotypes. Therefore, mixed models can confidently be used to evaluate stability in plant breeding programs, even with highly unbalanced data. PMID:26600484

  11. A variational approach to multi-phase motion of gas, liquid and solid based on the level set method

    NASA Astrophysics Data System (ADS)

    Yokoi, Kensuke

    2009-07-01

    We propose a simple and robust numerical algorithm to deal with multi-phase motion of gas, liquid and solid based on the level set method [S. Osher, J.A. Sethian, Front propagating with curvature-dependent speed: Algorithms based on Hamilton-Jacobi formulation, J. Comput. Phys. 79 (1988) 12; M. Sussman, P. Smereka, S. Osher, A level set approach for capturing solution to incompressible two-phase flow, J. Comput. Phys. 114 (1994) 146; J.A. Sethian, Level Set Methods and Fast Marching Methods, Cambridge University Press, 1999; S. Osher, R. Fedkiw, Level Set Methods and Dynamics Implicit Surface, Applied Mathematical Sciences, vol. 153, Springer, 2003]. In Eulerian framework, to simulate interaction between a moving solid object and an interfacial flow, we need to define at least two functions (level set functions) to distinguish three materials. In such simulations, in general two functions overlap and/or disagree due to numerical errors such as numerical diffusion. In this paper, we resolved the problem using the idea of the active contour model [M. Kass, A. Witkin, D. Terzopoulos, Snakes: active contour models, International Journal of Computer Vision 1 (1988) 321; V. Caselles, R. Kimmel, G. Sapiro, Geodesic active contours, International Journal of Computer Vision 22 (1997) 61; G. Sapiro, Geometric Partial Differential Equations and Image Analysis, Cambridge University Press, 2001; R. Kimmel, Numerical Geometry of Images: Theory, Algorithms, and Applications, Springer-Verlag, 2003] introduced in the field of image processing.

  12. Design of QoS-Aware Multi-Level MAC-Layer for Wireless Body Area Network.

    PubMed

    Hu, Long; Zhang, Yin; Feng, Dakui; Hassan, Mohammad Mehedi; Alelaiwi, Abdulhameed; Alamri, Atif

    2015-12-01

    With the advances in wearable computing and various wireless technologies, there is an increasing trend to outsource body signals from wireless body area network (WBAN) to outside world including cyber space, healthcare big data clouds, etc. Since the environmental and physiological data collected by multimodal sensors have different importance, the provisioning of quality of service (QoS) for the sensory data in WBAN is a critical issue. This paper proposes multiple level-based QoS design at WBAN media access control layer in terms of user level, data level and time level. In the proposed QoS provisioning scheme, different users have different priorities, various sensory data collected by different sensor nodes have different importance, while data priority for the same sensor node varies over time. The experimental results show that the proposed multi-level based QoS provisioning solution in WBAN yields better performance for meeting QoS requirements of personalized healthcare applications while achieving energy saving. PMID:26490150

  13. Multi-decadal sea level fluctuations in the North Pacific based on the historical ocean hydrographic data

    NASA Astrophysics Data System (ADS)

    Suzuki, T.; Ishii, M.

    2012-12-01

    Using a historical ocean hydrographic data, decadal to multi-decadal baroclinic sea level changes from 1951 to 2007 in the North Pacific are investigated. The fluctuations of the baroclinic sea level anomalies are decomposed to the first baroclinic mode and the rest, considering two oceanic physical processes: dynamical response of the main pycnocline to wind forcing and steric contribution of substantial water mass density change in the upper ocean. The first baroclinic sea level change exhibits the changes in the subtropical gyre in the North Pacific as suggested by previous studies. The sea level change around the Kuroshio Extension (KE) has bi-decadal and penta-decadal fluctuations, which are mainly explained as the first baroclinic response to the basin-scale wind stress change. In addition to this, the rest of baroclinic modes are not negligible around the KE recirculation region over penta-decadal fluctuation. This fluctuation results from mainly density change of the upper ocean, which is consistent with the heat transport change due to the changes in the strength of the Kuroshio and the KE shown in the first mode. The fluctuations of the composite of the rest modes are also dominant in the central North Pacific, in which ocean surface heat flux plays an important role. These sea level changes affect ocean surface currents as well as that in the first mode.

  14. GROMACS: High performance molecular simulations through multi-level parallelism from laptops to supercomputers

    NASA Astrophysics Data System (ADS)

    Abraham, Mark James; Murtola, Teemu; Schulz, Roland; Pll, Szilrd; Smith, Jeremy C.; Hess, Berk; Lindahl, Erik

    2015-09-01

    GROMACS is one of the most widely used open-source and free software codes in chemistry, used primarily for dynamical simulations of biomolecules. It provides a rich set of calculation types, preparation and analysis tools. Several advanced techniques for free-energy calculations are supported. In version 5, it reaches new performance heights, through several new and enhanced parallelization algorithms. These work on every level; SIMD registers inside cores, multithreading, heterogeneous CPU-GPU acceleration, state-of-the-art 3D domain decomposition, and ensemble-level parallelization through built-in replica exchange and the separate Copernicus framework. The latest best-in-class compressed trajectory storage format is supported.

  15. [A pyramidal multiphase level set algorithm for multi-object segmentation of 3-D medical images].

    PubMed

    Zheng, Gang; Wang, Huinan

    2008-10-01

    The Chan and Vese (C-V) model using one level set function can only represent one object and one background by the sign of the level set function and is not able to express multiple sub-objects of the object region in three-dimensional (3-D) medical images. To deal with the problem, the two-dimensional (2-D) C-V model is firstly extended to the 3-D model. Secondly, a key technique,designated as the technique of painting background, ensures that the evolving curve stops only inside the object following the theory of simultaneous brightness contrast. Thirdly, a pyramidal multiphase level set algorithm for segmentation is developed by the 3-D C-V model and the proposed technique. Finally, experimental results show that the proposed algorithm is able to partition a given image into multiple objects (n-1 level sets for n objects). Also, the algorithm is especially effective for the detection of sub-objects with weak boundaries. PMID:19024432

  16. Water in the Middle East, a Secondary and College Level Multi-Media Study.

    ERIC Educational Resources Information Center

    Manneberg, Eliezer

    The secondary and college level guide outlines a course of study on the Middle East, with emphasis on water problems of the area. Among the course objectives are the following: (1) make generalizations about particular Middle Eastern cultures and support them with evidence; (2) interpret environmental and social data from specific Middle Eastern

  17. Multi-level model for 2D human motion analysis and description

    NASA Astrophysics Data System (ADS)

    Foures, Thomas; Joly, Philippe

    2003-01-01

    This paper deals with the proposition of a model for human motion analysis in a video. Its main caracteristic is to adapt itself automatically to the current resolution, the actual quality of the picture, or the level of precision required by a given application, due to its possible decomposition into several hierarchical levels. The model is region-based to address some analysis processing needs. The top level of the model is only defined with 5 ribbons, which can be cut into sub-ribbons regarding to a given (or an expected) level of details. Matching process between model and current picture consists in the comparison of extracted subject shape with a graphical rendering of the model built on the base of some computed parameters. The comparison is processed by using a chamfer matching algorithm. In our developments, we intend to realize a platform of interaction between a dancer and tools synthetizing abstract motion pictures and music in the conditions of a real-time dialogue between a human and a computer. In consequence, we use this model in a perspective of motion description instead of motion recognition: no a priori gestures are supposed to be recognized as far as no a priori application is specially targeted. The resulting description will be made following a Description Scheme compliant with the movement notation called "Labanotation".

  18. Facilitating Pervasive Planning: Multi-Level Institutional Planning. AIR Forum 1979 Paper.

    ERIC Educational Resources Information Center

    Mims, R. Sue

    Ways in which planning can be enhanced across organizational levels within higher education institutions are outlined, and examples of institutional planning are analyzed from centralized/decentralized perspectives. Generalizations about planning are drawn with particular attention to ways in which effective human planning behavior can be

  19. Overpopulation, Gender Differences and Cultural Attitudes: A Multi-level Lesson Plan for (ESL) College Students.

    ERIC Educational Resources Information Center

    Miles, Norma D.

    1996-01-01

    Provides a number of reading and discussion exercises on issue-oriented questions (such as "overpopulation") that may be used for just about any level of English-as-a-Second-Language instruction. Suggests a role-play exercise in imitation of the television show "Dating Game." (TB)

  20. Evaluating the Impacts of ICT Use: A Multi-Level Analysis with Hierarchical Linear Modeling

    ERIC Educational Resources Information Center

    Song, Hae-Deok; Kang, Taehoon

    2012-01-01

    The purpose of this study is to evaluate the impacts of ICT use on achievements by considering not only ICT use, but also the process and background variables that influence ICT use at both the student- and school-level. This study was conducted using data from the 2010 Survey of Seoul Education Longitudinal Research. A Hierarchical Linear

  1. A SiC MOSFET Based Inverter for Wireless Power Transfer Applications

    SciTech Connect

    Onar, Omer C; Chinthavali, Madhu Sudhan; Campbell, Steven L; Ning, Puqi; White, Cliff P; Miller , John M.

    2014-01-01

    In a wireless power transfer (WPT) system, efficiency of the power conversion stages is crucial so that the WPT technology can compete with the conventional conductive charging systems. Since there are 5 or 6 power conversion stages, each stage needs to be as efficient as possible. SiC inverters are crucial in this case; they can handle high frequency operation and they can operate at relatively higher temperatures resulting in reduces cost and size for the cooling components. This study presents the detailed power module design, development, and fabrication of a SiC inverter. The proposed inverter has been tested at three center frequencies that are considered for the WPT standardization. Performance of the inverter at the same target power transfer level is analyzed along with the other system components. In addition, another SiC inverter has been built in authors laboratory by using the ORNL designed and developed SiC modules. It is shown that the inverter with ORNL packaged SiC modules performs simular to that of the inverter having commercially available SiC modules.

  2. The multi-millennial Antarctic commitment to future sea-level rise

    NASA Astrophysics Data System (ADS)

    Golledge, N. R.; Kowalewski, D. E.; Naish, T. R.; Levy, R. H.; Fogwill, C. J.; Gasson, E. G. W.

    2015-10-01

    Atmospheric warming is projected to increase global mean surface temperatures by 0.3 to 4.8 degrees Celsius above pre-industrial values by the end of this century. If anthropogenic emissions continue unchecked, the warming increase may reach 8-10 degrees Celsius by 2300 (ref. 2). The contribution that large ice sheets will make to sea-level rise under such warming scenarios is difficult to quantify because the equilibrium-response timescale of ice sheets is longer than those of the atmosphere or ocean. Here we use a coupled ice-sheet/ice-shelf model to show that if atmospheric warming exceeds 1.5 to 2 degrees Celsius above present, collapse of the major Antarctic ice shelves triggers a centennial- to millennial-scale response of the Antarctic ice sheet in which enhanced viscous flow produces a long-term commitment (an unstoppable contribution) to sea-level rise. Our simulations represent the response of the present-day Antarctic ice-sheet system to the oceanic and climatic changes of four representative concentration pathways (RCPs) from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. We find that substantial Antarctic ice loss can be prevented only by limiting greenhouse gas emissions to RCP 2.6 levels. Higher-emissions scenarios lead to ice loss from Antarctic that will raise sea level by 0.6-3 metres by the year 2300. Our results imply that greenhouse gas emissions in the next few decades will strongly influence the long-term contribution of the Antarctic ice sheet to global sea level.

  3. The multi-millennial Antarctic commitment to future sea-level rise.

    PubMed

    Golledge, N R; Kowalewski, D E; Naish, T R; Levy, R H; Fogwill, C J; Gasson, E G W

    2015-10-15

    Atmospheric warming is projected to increase global mean surface temperatures by 0.3 to 4.8 degrees Celsius above pre-industrial values by the end of this century. If anthropogenic emissions continue unchecked, the warming increase may reach 8-10 degrees Celsius by 2300 (ref. 2). The contribution that large ice sheets will make to sea-level rise under such warming scenarios is difficult to quantify because the equilibrium-response timescale of ice sheets is longer than those of the atmosphere or ocean. Here we use a coupled ice-sheet/ice-shelf model to show that if atmospheric warming exceeds 1.5 to 2 degrees Celsius above present, collapse of the major Antarctic ice shelves triggers a centennial- to millennial-scale response of the Antarctic ice sheet in which enhanced viscous flow produces a long-term commitment (an unstoppable contribution) to sea-level rise. Our simulations represent the response of the present-day Antarctic ice-sheet system to the oceanic and climatic changes of four representative concentration pathways (RCPs) from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. We find that substantial Antarctic ice loss can be prevented only by limiting greenhouse gas emissions to RCP 2.6 levels. Higher-emissions scenarios lead to ice loss from Antarctic that will raise sea level by 0.6-3 metres by the year 2300. Our results imply that greenhouse gas emissions in the next few decades will strongly influence the long-term contribution of the Antarctic ice sheet to global sea level. PMID:26469052

  4. A machine learning approach to multi-level ECG signal quality classification.

    PubMed

    Li, Qiao; Rajagopalan, Cadathur; Clifford, Gari D

    2014-12-01

    Current electrocardiogram (ECG) signal quality assessment studies have aimed to provide a two-level classification: clean or noisy. However, clinical usage demands more specific noise level classification for varying applications. This work outlines a five-level ECG signal quality classification algorithm. A total of 13 signal quality metrics were derived from segments of ECG waveforms, which were labeled by experts. A support vector machine (SVM) was trained to perform the classification and tested on a simulated dataset and was validated using data from the MIT-BIH arrhythmia database (MITDB). The simulated training and test datasets were created by selecting clean segments of the ECG in the 2011 PhysioNet/Computing in Cardiology Challenge database, and adding three types of real ECG noise at different signal-to-noise ratio (SNR) levels from the MIT-BIH Noise Stress Test Database (NSTDB). The MITDB was re-annotated for five levels of signal quality. Different combinations of the 13 metrics were trained and tested on the simulated datasets and the best combination that produced the highest classification accuracy was selected and validated on the MITDB. Performance was assessed using classification accuracy (Ac), and a single class overlap accuracy (OAc), which assumes that an individual type classified into an adjacent class is acceptable. An Ac of 80.26% and an OAc of 98.60% on the test set were obtained by selecting 10 metrics while 57.26% (Ac) and 94.23% (OAc) were the numbers for the unseen MITDB validation data without retraining. By performing the fivefold cross validation, an Ac of 88.07±0.32% and OAc of 99.34±0.07% were gained on the validation fold of MITDB. PMID:25306242

  5. ADORA2A Gene variation, caffeine, and emotional processing: a multi-level interaction on startle reflex.

    PubMed

    Domschke, Katharina; Gajewska, Agnieszka; Winter, Bernward; Herrmann, Martin J; Warrings, Bodo; Mhlberger, Andreas; Wosnitza, Katherina; Glotzbach, Evelyn; Conzelmann, Annette; Dlugos, Andrea; Fobker, Manfred; Jacob, Christian; Arolt, Volker; Reif, Andreas; Pauli, Paul; Zwanzger, Peter; Deckert, Jrgen

    2012-02-01

    There is converging evidence for genetic, biochemical, and neuropsychological factors to increase the risk for anxiety and anxiety disorders. The pathogenesis of anxiety disorders is assumed to be influenced by a complex interaction of these individual risk factors on several levels, affecting intermediate phenotypes of anxiety such as the startle reflex. Thus, in the present double-blind, placebo-controlled study we attempted to paradigmatically investigate a multi-level pathogenetic model of anxiety by testing the effect of 300?mg caffeine citrate as an antagonist at the adenosine A2A receptor vs placebo on the emotion-potentiated (unpleasant, neutral, and pleasant International Affective Picture System pictures) startle reflex in 110 healthy individuals (male=56, female=54) stratified for the adenosine A2A receptor (ADORA2A) 1976T>C polymorphism (rs5751876). In addition to the expected main effect of picture category (highest startle amplitude for unpleasant, lowest for pleasant pictures) groups across all ADORA2A 1976T>C genotype and intervention (caffeine vs placebo) groups, an interaction effect of genotype, intervention, and picture category was discerned: In ADORA2A 1976TT risk genotype carriers, highest startle magnitudes were observed after caffeine administration in response to unpleasant pictures, with this effect arising particularly from the female subgroup. Our data point to a complex, multi-level, and potentially gender-specific pathogenetic model of anxiety, with genetic and biochemical factors interactively increasing the risk of maladaptive emotional processing and thereby possibly also anxiety disorders. The present findings may eventually aid in improving primary and secondary prevention by sharpening the risk profiles of anxiety-prone individuals. PMID:22012471

  6. ADORA2A Gene Variation, Caffeine, and Emotional Processing: A Multi-level Interaction on Startle Reflex

    PubMed Central

    Domschke, Katharina; Gajewska, Agnieszka; Winter, Bernward; Herrmann, Martin J; Warrings, Bodo; Mühlberger, Andreas; Wosnitza, Katherina; Glotzbach, Evelyn; Conzelmann, Annette; Dlugos, Andrea; Fobker, Manfred; Jacob, Christian; Arolt, Volker; Reif, Andreas; Pauli, Paul; Zwanzger, Peter; Deckert, Jürgen

    2012-01-01

    There is converging evidence for genetic, biochemical, and neuropsychological factors to increase the risk for anxiety and anxiety disorders. The pathogenesis of anxiety disorders is assumed to be influenced by a complex interaction of these individual risk factors on several levels, affecting intermediate phenotypes of anxiety such as the startle reflex. Thus, in the present double-blind, placebo-controlled study we attempted to paradigmatically investigate a multi-level pathogenetic model of anxiety by testing the effect of 300 mg caffeine citrate as an antagonist at the adenosine A2A receptor vs placebo on the emotion-potentiated (unpleasant, neutral, and pleasant International Affective Picture System pictures) startle reflex in 110 healthy individuals (male=56, female=54) stratified for the adenosine A2A receptor (ADORA2A) 1976T>C polymorphism (rs5751876). In addition to the expected main effect of picture category (highest startle amplitude for unpleasant, lowest for pleasant pictures) groups across all ADORA2A 1976T>C genotype and intervention (caffeine vs placebo) groups, an interaction effect of genotype, intervention, and picture category was discerned: In ADORA2A 1976TT risk genotype carriers, highest startle magnitudes were observed after caffeine administration in response to unpleasant pictures, with this effect arising particularly from the female subgroup. Our data point to a complex, multi-level, and potentially gender-specific pathogenetic model of anxiety, with genetic and biochemical factors interactively increasing the risk of maladaptive emotional processing and thereby possibly also anxiety disorders. The present findings may eventually aid in improving primary and secondary prevention by sharpening the risk profiles of anxiety-prone individuals. PMID:22012471

  7. Static Characteristics of the Ferroelectric Transistor Inverter

    NASA Technical Reports Server (NTRS)

    Mitchell, Cody; Laws, crystal; MacLeond, Todd C.; Ho, Fat D.

    2010-01-01

    The inverter is one of the most fundamental building blocks of digital logic, and it can be used as the foundation for understanding more complex logic gates and circuits. This paper presents the characteristics of an inverter circuit using a ferroelectric field-effect transistor. The voltage transfer characteristics are analyzed with respect to varying parameters such as supply voltage, input voltage, and load resistance. The effects of the ferroelectric layer between the gate and semiconductor are examined, and comparisons are made between the inverters using ferroelectric transistors and those using traditional MOSFETs.

  8. Response to Natural Hazards: Multi-Level Governance Challenges in Newfoundland & Labrador, Canada

    NASA Astrophysics Data System (ADS)

    Catto, N.; Tomblin, S.

    2009-04-01

    Newfoundland and Labrador's perspective on emergency measures in response to natural hazards is shaped by several factors. Climate, meteorology, and terrain are the dominant factors both in the occurrence of events and the responses to them. The economy, dominated by resource-based activities, is a significant influence in accentuating exposure to natural hazards. In this situation, the role of earth scientists is critical. However, effective input from geographers, geomorphologists, and climatologists requires an understanding of the governance regime. For emergency services, both formal public policy responses, informal mechanisms, and the interfacing that exists between public policy mechanisms and social forces are significant. In an era where more and more problems are considered as "interdependent", and require different governmental, social, and professional expertise forces to come together to address objectives, there is interest in exploring and analyzing patterns of communication, interactions and policy learning across inherited silos. A major political-policy struggle is the challenge of managing rural-urban differences in capacity and perspective. Another challenge involves finding ways for professions to merge their protocols and cultures. Embracing best practices associated with natural hazards and emergency preparedness is influenced by the power and independence of various groups involved. Critical events provide windows of opportunity for urging new approaches, but whether these become institutionalized or not normally depends on the interplay of ideas, interests, individuals, and institutions. In coping with natural hazards, renewing governance required finding new incentives to integrate across jurisdictions and disciplinary and governmental-society boundaries. Perception and response to natural hazards is very much connected with the historical-policy context. The pace of effective response indicates the impact of culture, capacity, institutions, and interests in the struggle to shift priorities, especially if these are being imposed externally. Emergency planning involves contestation, shifting priorities, building knowledge capacity, and merging policy and jurisdictional networks based on best practices. It requires renewing governance, coordinating planning, data collection, building infrastructure and establishing a common vision where different interests can work together to promote common values and objectives. However, emergency planning is difficult to change and reform based on a common vision and approach, because the inherited formal and informal structures tend to be very complex multi-disciplinary systems. Not only does this pose difficulties in renewing governance, establishing clear lines of authority, and responsibility across jurisdictions, it is very difficult for previously unrecognized groups to participate. Natural hazard researchers, unfortunately, frequently fit into this latter category.

  9. DAHITI - an innovative approach for estimating water level time series over inland waters using multi-mission satellite altimetry

    NASA Astrophysics Data System (ADS)

    Schwatke, C.; Dettmering, D.; Bosch, W.; Seitz, F.

    2015-10-01

    Satellite altimetry has been designed for sea level monitoring over open ocean areas. However, for some years, this technology has also been used to retrieve water levels from reservoirs, wetlands and in general any inland water body, although the radar altimetry technique has been especially applied to rivers and lakes. In this paper, a new approach for the estimation of inland water level time series is described. It is used for the computation of time series of rivers and lakes available through the web service "Database for Hydrological Time Series over Inland Waters" (DAHITI). The new method is based on an extended outlier rejection and a Kalman filter approach incorporating cross-calibrated multi-mission altimeter data from Envisat, ERS-2, Jason-1, Jason-2, TOPEX/Poseidon, and SARAL/AltiKa, including their uncertainties. The paper presents water level time series for a variety of lakes and rivers in North and South America featuring different characteristics such as shape, lake extent, river width, and data coverage. A comprehensive validation is performed by comparisons with in situ gauge data and results from external inland altimeter databases. The new approach yields rms differences with respect to in situ data between 4 and 36 cm for lakes and 8 and 114 cm for rivers. For most study cases, more accurate height information than from other available altimeter databases can be achieved.

  10. Kalman filter approach for estimating water level time series over inland water using multi-mission satellite altimetry

    NASA Astrophysics Data System (ADS)

    Schwatke, C.; Dettmering, D.; Bosch, W.; Seitz, F.

    2015-05-01

    Satellite altimetry has been designed for sea level monitoring over open ocean areas. However, since some years, this technology is also used for observing inland water levels of lakes and rivers. In this paper, a new approach for the estimation of inland water level time series is described. It is used for the computation of time series available through the web service "Database for Hydrological Time Series over Inland Water" (DAHITI). The method is based on a Kalman filter approach incorporating multi-mission altimeter observations and their uncertainties. As input data, cross-calibrated altimeter data from Envisat, ERS-2, Jason-1, Jason-2, Topex/Poseidon, and SARAL/AltiKa are used. The paper presents water level time series for a variety of lakes and rivers in North and South America featuring different characteristics such as shape, lake extent, river width, and data coverage. A comprehensive validation is performed by comparison with in-situ gauge data and results from external inland altimeter databases. The new approach yields RMS differences with respect to in-situ data between 4 and 38 cm for lakes and 12 and 139 cm for rivers, respectively. For most study cases, more accurate height information than from available other altimeter data bases can be achieved.

  11. toyLIFE: a computational framework to study the multi-level organisation of the genotype-phenotype map

    PubMed Central

    Arias, Clemente F.; Catalán, Pablo; Manrubia, Susanna; Cuesta, José A.

    2014-01-01

    The genotype-phenotype map is an essential object to understand organismal complexity and adaptability. However, its experimental characterisation is a daunting task. Thus, simple models have been proposed and investigated. They have revealed that genotypes differ in their robustness to mutations; phenotypes are represented by a broadly varying number of genotypes, and simple point mutations suffice to navigate the space of genotypes while maintaining a phenotype. Nonetheless, most current models focus only on one level of the map (folded molecules, gene regulatory networks, or networks of metabolic reactions), so that many relevant questions cannot be addressed. Here we introduce toyLIFE, a multi-level model for the genotype-phenotype map based on simple genomes and interaction rules from which a complex behaviour at upper levels emerges —remarkably plastic gene regulatory networks and metabolism. toyLIFE is a tool that permits the investigation of how different levels are coupled, in particular how and where mutations affect phenotype or how the presence of certain metabolites determines the dynamics of toyLIFE gene regulatory networks. The model can easily incorporate evolution through more complex mutations, recombination, or gene duplication and deletion, thus opening an avenue to explore extended genotype-phenotype maps. PMID:25520296

  12. A Multi-Level Geographical Study of Italian Political Elections from Twitter Data

    PubMed Central

    Caldarelli, Guido; Chessa, Alessandro; Pammolli, Fabio; Pompa, Gabriele; Puliga, Michelangelo; Riccaboni, Massimo; Riotta, Gianni

    2014-01-01

    In this paper we present an analysis of the behavior of Italian Twitter users during national political elections. We monitor the volumes of the tweets related to the leaders of the various political parties and we compare them to the elections results. Furthermore, we study the topics that are associated with the co-occurrence of two politicians in the same tweet. We cannot conclude, from a simple statistical analysis of tweet volume and their time evolution, that it is possible to precisely predict the election outcome (or at least not in our case of study that was characterized by a too-close-to-call scenario). On the other hand, we found that the volume of tweets and their change in time provide a very good proxy of the final results. We present this analysis both at a national level and at smaller levels, ranging from the regions composing the country to macro-areas (North, Center, South). PMID:24802857

  13. Circadian rhythms and mood: Opportunities for multi-level analyses in genomics and neuroscience

    PubMed Central

    Li, Jun Z

    2014-01-01

    In the healthy state, both circadian rhythm and mood are stable against perturbations, yet they are capable of adjusting to altered internal cues or ongoing changes in external conditions. The dual demands of stability and flexibility are met by the collective properties of complex neural networks. Disruption of this balance underlies both circadian rhythm abnormality and mood disorders. However, we do not fully understand the network properties that govern the crosstalk between the circadian system and mood regulation. This puzzle reflects a challenge at the center of neurobiology, and its solution requires the successful integration of existing data across all levels of neural organization, from molecules, cells, circuits, network dynamics, to integrated mental function. This essay discusses several open questions confronting the cross-level synthesis, and proposes that circadian regulation, and its role in mood, stands as a uniquely tractable system to study the causal mechanisms of neural adaptation. PMID:24853393

  14. A multi-level geographical study of Italian political elections from Twitter data.

    PubMed

    Caldarelli, Guido; Chessa, Alessandro; Pammolli, Fabio; Pompa, Gabriele; Puliga, Michelangelo; Riccaboni, Massimo; Riotta, Gianni

    2014-01-01

    In this paper we present an analysis of the behavior of Italian Twitter users during national political elections. We monitor the volumes of the tweets related to the leaders of the various political parties and we compare them to the elections results. Furthermore, we study the topics that are associated with the co-occurrence of two politicians in the same tweet. We cannot conclude, from a simple statistical analysis of tweet volume and their time evolution, that it is possible to precisely predict the election outcome (or at least not in our case of study that was characterized by a "too-close-to-call" scenario). On the other hand, we found that the volume of tweets and their change in time provide a very good proxy of the final results. We present this analysis both at a national level and at smaller levels, ranging from the regions composing the country to macro-areas (North, Center, South). PMID:24802857

  15. Application of a CBPR Framework to Inform a Multi-level Tobacco Cessation Intervention in Public Housing Neighborhoods

    PubMed Central

    Tingen, Martha S.; Jarriel, Stacey Crawford; Caleb, Maudesta; Simmons, Alisha; Brunson, Juanita; Mueller, Martina; Ahluwalia, Jasjit S.; Newman, Susan D.; Cox, Melissa J.; Magwood, Gayenell; Hurman, Christina

    2015-01-01

    African American women in urban, high poverty neighborhoods have high rates of smoking, difficulties with quitting, and disproportionate tobacco-related health disparities. Prior research utilizing conventional “outsider driven” interventions targeted to individuals has failed to show effective cessation outcomes. This paper describes the application of a community-based participatory research (CBPR) framework to inform a culturally situated, ecological based, multi-level tobacco cessation intervention in public housing neighborhoods. The CBPR framework encompasses problem identification, planning and feasibility/pilot testing, implementation, evaluation, and dissemination. There have been multiple partners in this process including public housing residents, housing authority administrators, community health workers, tenant associations, and academic investigators. The advisory process has evolved from an initial small steering group to our current institutional community advisory boards. Our decade-long CBPR journey produced design innovations, promising preliminary outcomes, and a full-scaled implementation study in two states. Challenges include sustaining engagement with evolving study partners, maintaining equity and power in the partnerships, and long-term sustainability of the intervention. Implications include applicability of the framework with other CBPR partnerships, especially scaling up evolutionary grassroots involvement to multi-regional partnerships. PMID:22124619

  16. Application of a CBPR framework to inform a multi-level tobacco cessation intervention in public housing neighborhoods.

    PubMed

    Andrews, Jeannette O; Tingen, Martha S; Jarriel, Stacey Crawford; Caleb, Maudesta; Simmons, Alisha; Brunson, Juanita; Mueller, Martina; Ahluwalia, Jasjit S; Newman, Susan D; Cox, Melissa J; Magwood, Gayenell; Hurman, Christina

    2012-09-01

    African American women in urban, high poverty neighborhoods have high rates of smoking, difficulties with quitting, and disproportionate tobacco-related health disparities. Prior research utilizing conventional "outsider driven" interventions targeted to individuals has failed to show effective cessation outcomes. This paper describes the application of a community-based participatory research (CBPR) framework to inform a culturally situated, ecological based, multi-level tobacco cessation intervention in public housing neighborhoods. The CBPR framework encompasses problem identification, planning and feasibility/pilot testing, implementation, evaluation, and dissemination. There have been multiple partners in this process including public housing residents, housing authority administrators, community health workers, tenant associations, and academic investigators. The advisory process has evolved from an initial small steering group to our current institutional community advisory boards. Our decade-long CBPR journey produced design innovations, promising preliminary outcomes, and a full-scaled implementation study in two states. Challenges include sustaining engagement with evolving study partners, maintaining equity and power in the partnerships, and long-term sustainability of the intervention. Implications include applicability of the framework with other CBPR partnerships, especially scaling up evolutionary grassroots involvement to multi-regional partnerships. PMID:22124619

  17. On combining multi-normalization and ancillary measures for the optimal score level fusion of fingerprint and voice biometrics

    NASA Astrophysics Data System (ADS)

    Mohammed Anzar, Sharafudeen Thaha; Sathidevi, Puthumangalathu Savithri

    2014-12-01

    In this paper, we have considered the utility of multi-normalization and ancillary measures, for the optimal score level fusion of fingerprint and voice biometrics. An efficient matching score preprocessing technique based on multi-normalization is employed for improving the performance of the multimodal system, under various noise conditions. Ancillary measures derived from the feature space and the score space are used in addition to the matching score vectors, for weighing the modalities, based on their relative degradation. Reliability (dispersion) and the separability (inter-/intra-class distance and d-prime statistics) measures under various noise conditions are estimated from the individual modalities, during the training/validation stage. The `best integration weights' are then computed by algebraically combining these measures using the weighted sum rule. The computed integration weights are then optimized against the recognition accuracy using techniques such as grid search, genetic algorithm and particle swarm optimization. The experimental results show that, the proposed biometric solution leads to considerable improvement in the recognition performance even under low signal-to-noise ratio (SNR) conditions and reduces the false acceptance rate (FAR) and false rejection rate (FRR), making the system useful for security as well as forensic applications.

  18. Assessing the effectiveness of interventions to promote advance directives among older adults: a systematic review and multi-level analysis.

    PubMed

    Bravo, Gina; Dubois, Marie-France; Wagneur, Bernard

    2008-10-01

    Many studies have investigated the effectiveness of interventions in promoting advance directives (ADs) but there is uncertainty as to what works best, and in whom. We conducted a systematic review of the evidence in this regard, using both classical meta-analysis approaches and multi-level analyses. Eleven databases were searched for relevant reports published through March 2007. All prospective studies were eligible, whether involving a single group or several and, in the latter case, regardless of the allocation mechanism. Outcomes included formal and informal ADs assessed by chart review or self-report. Heterogeneous sets of outcomes were pooled under a random-effects model. The search yielded 55 studies, half of which targeted outpatients. Most groups of subjects were educated in a single session led by one healthcare professional. Outcomes were measured within six months of the intervention in 73% of cases. The largest set of single-arm studies yielded an overall AD completion rate of 45.6%. Across randomized trials, the largest pooled odds ratio was 4.0, decreasing to 2.6 when all comparative studies were included. Multi-variable analyses identified the provision of oral information over multiple sessions as the most successful intervention. This was true regardless of the target population. These findings support the effectiveness of educational interventions in increasing the formulation of ADs and provide practical advice on how best to achieve this goal. PMID:18644667

  19. Fulfilling Dreams in Adult Education: Managing the Multi-Level Classroom

    ERIC Educational Resources Information Center

    Haley, Rebecca J.

    2008-01-01

    Have you ever wondered how Laura Ingalls Wilder taught all of her students in the little one-room school house in The Little House on the Prairie series? How did she teach students on so many different levels and all at the same time? Well, that is exactly what it is like in most adult education classrooms today. The purpose of this paper is to

  20. A Multi-Center Assessment of Nutrient Levels and Foods Provided by Hospital Patient Menus

    PubMed Central

    Trang, Susan; Fraser, Jackie; Wilkinson, Lori; Steckham, Katherine; Oliphant, Heather; Fletcher, Heather; Tzianetas, Roula; Arcand, JoAnne

    2015-01-01

    Diets of high nutritional quality can aid in the prevention and management of malnutrition in hospitalized patients. This study evaluated the nutritional quality of hospital patient menus. At three large acute care hospitals in Ontario, Canada, 84 standard menus were evaluated, which included regular and carbohydrate-controlled diets and 3000 mg and 2000 mg sodium diets. Mean levels of calories, macronutrients and vitamins and minerals provided were calculated. Comparisons were made with the Dietary Reference Intakes (DRI) and Canada’s Food Guide (CFG) recommendations. Calorie levels ranged from 1281 to 3007 kcal, with 45% of menus below 1600 kcal. Protein ranged from 49 to 159 g (0.9–1.1 g/kg/day). Energy and protein levels were highest in carbohydrate-controlled menus. All regular and carbohydrate-controlled menus provided macronutrients within the Acceptable Macronutrient Distribution Ranges. The proportion of regular diet menus meeting the DRIs: 0% for fiber; 7% for calcium; 57% for vitamin C; and 100% for iron. Compared to CFG recommended servings, 35% met vegetables and fruit and milk and alternatives, 11% met grain products and 8% met meat and alternatives. These data support the need for frequent monitoring and evaluation of menus, food procurement and menu planning policies and for sufficient resources to ensure menu quality. PMID:26569294

  1. Evaluating regional differences in breast-feeding in French maternity units: a multi-level approach

    PubMed Central

    Bonet, Mercedes; Blondel, Batrice; Khoshnood, Babak

    2010-01-01

    Objectives To study how individual and regional characteristics might explain regional variations in breastfeeding rates in maternity units and to identify outlier regions with very low or high breastfeeding rates. Design Individual characteristics (mother and infant) were collected during hospital stay. All newborns fed entirely or partly on breast milk were considered breastfed. Regional characteristics were extracted from census data. Statistical analysis included multilevel models and estimation of empirical Bayes residuals to identify outlier regions. Setting all births in all administrative regions in France in 2003. Subjects a national representative sample of 13 186 live births. Results Breastfeeding rates in maternity units varied from 43% to 80% across regions. Differences in the distribution of individual characteristics accounted for 55% of these variations. We identified two groups of regions with the lowest and the highest breastfeeding rates, after adjusting for individual-level characteristics. In addition to maternal occupation and nationality, the social characteristics of regions, particularly the populations educational level and the percentage of non-French residents, were significantly associated with breastfeeding rates. Conclusions Social characteristics at both the individual and regional levels influence breastfeeding rates in maternity units. Promotion policies should be directed at specific regions, groups within the community, and categories of mothers, to reduce the gaps and increase the overall breastfeeding rate. PMID:20576192

  2. A Multi-Center Assessment of Nutrient Levels and Foods Provided by Hospital Patient Menus.

    PubMed

    Trang, Susan; Fraser, Jackie; Wilkinson, Lori; Steckham, Katherine; Oliphant, Heather; Fletcher, Heather; Tzianetas, Roula; Arcand, JoAnne

    2015-11-01

    Diets of high nutritional quality can aid in the prevention and management of malnutrition in hospitalized patients. This study evaluated the nutritional quality of hospital patient menus. At three large acute care hospitals in Ontario, Canada, 84 standard menus were evaluated, which included regular and carbohydrate-controlled diets and 3000 mg and 2000 mg sodium diets. Mean levels of calories, macronutrients and vitamins and minerals provided were calculated. Comparisons were made with the Dietary Reference Intakes (DRI) and Canada's Food Guide (CFG) recommendations. Calorie levels ranged from 1281 to 3007 kcal, with 45% of menus below 1600 kcal. Protein ranged from 49 to 159 g (0.9-1.1 g/kg/day). Energy and protein levels were highest in carbohydrate-controlled menus. All regular and carbohydrate-controlled menus provided macronutrients within the Acceptable Macronutrient Distribution Ranges. The proportion of regular diet menus meeting the DRIs: 0% for fiber; 7% for calcium; 57% for vitamin C; and 100% for iron. Compared to CFG recommended servings, 35% met vegetables and fruit and milk and alternatives, 11% met grain products and 8% met meat and alternatives. These data support the need for frequent monitoring and evaluation of menus, food procurement and menu planning policies and for sufficient resources to ensure menu quality. PMID:26569294

  3. Dynamic multi-source X-ray tomography using a spacetime level set method

    NASA Astrophysics Data System (ADS)

    Niemi, Esa; Lassas, Matti; Kallonen, Aki; Harhanen, Lauri; Hmlinen, Keijo; Siltanen, Samuli

    2015-06-01

    A novel variant of the level set method is introduced for dynamic X-ray tomography. The target is allowed to change in time while being imaged by one or several source-detector pairs at a relatively high frame-rate. The algorithmic approach is motivated by the results in [22], showing that the modified level set method can tolerate highly incomplete projection data in stationary tomography. Furthermore, defining the level set function in spacetime enforces temporal continuity in the dynamic tomography context considered here. The tomographic reconstruction is found as a minimizer of a nonlinear functional. The functional contains a regularization term penalizing the L2 norms of up to n derivatives of the reconstruction. The case n = 1 is shown to be equivalent to a convex Tikhonov problem that has a unique minimizer. For n ? 2 the existence of a minimizer is proved under certain assumptions on the signal-to-noise ratio and the size of the regularization parameter. Numerical examples with both simulated and measured dynamic X-ray data are included, and the proposed method is found to yield reconstructions superior to standard methods such as FBP or non-negativity constrained Tikhonov regularization and favorably comparable to those of total variation regularization. Furthermore, the methodology can be adapted to a wide range of measurement arrangements with one or more X-ray sources.

  4. A multi-level model of blood lead as a function of air lead.

    PubMed

    Richmond-Bryant, Jennifer; Meng, Qingyu; Davis, J Allen; Cohen, Jonathan; Svendsgaard, David; Brown, James S; Tuttle, Lauren; Hubbard, Heidi; Rice, Joann; Kirrane, Ellen; Vinikoor-Imler, Lisa; Kotchmar, Dennis; Hines, Erin; Ross, Mary

    2013-09-01

    National and local declines in lead (Pb) in blood (PbB) over the past several years coincide with the decline in ambient air Pb (PbA) concentrations. The objective of this work is to evaluate how the relationship between PbB levels and PbA levels has changed following the phase out of leaded gasoline and tightened controls on industrial Pb emissions over the past 30 years among a national population sample. Participant-level data from the National Health and Nutrition Examination Survey (NHANES) were employed for two time periods (1988-1994 and 1999-2008), and the model was corrected for housing, demographic, socioeconomic, and other covariates present in NHANES. NHANES data for PbB and covariates were merged with PbA data from the U.S. Environmental Protection Agency. Linear mixed effects models (LMEs) were run to assess the relationship of PbB with PbA; sample weights were omitted, given biases encountered with the use of sample weights in LMEs. The 1988-1994 age-stratified results found that ln(PbB) was statistically significantly associated with ln(PbA) for all age groups. The consistent influence of PbA on PbB across age groups for the years 1988-1994 suggests a ubiquitous exposure unrelated to age of the sample population. The comparison of effect estimates for ln(PbA) shows a statistically significant effect estimate and ANOVA results for ln(PbB) for the 6- to 11-year and 12- to 19-year age groups during 1999-2008. The more recent finding suggests that PbA has less consistent influence on PbB compared with other factors. PMID:23727994

  5. Multi-Level Adaptive Techniques (MLAT) for singular-perturbation problems

    NASA Technical Reports Server (NTRS)

    Brandt, A.

    1978-01-01

    The multilevel (multigrid) adaptive technique, a general strategy of solving continuous problems by cycling between coarser and finer levels of discretization is described. It provides very fast general solvers, together with adaptive, nearly optimal discretization schemes. In the process, boundary layers are automatically either resolved or skipped, depending on a control function which expresses the computational goal. The global error decreases exponentially as a function of the overall computational work, in a uniform rate independent of the magnitude of the singular-perturbation terms. The key is high-order uniformly stable difference equations, and uniformly smoothing relaxation schemes.

  6. Temperature control in wafer-level testing of large multi-segment electromigration test structures

    NASA Technical Reports Server (NTRS)

    Zamani, Nasser; Lin, Yu-Sang

    1988-01-01

    The paper describes two methods for maintaining a constant metallization temperature throughout a wafer-level isothermal electromigration test of large multisegment test structures where Joule-heating is high and chip to chuck thermal contact is poor. In the first method, an initial calibration of Joule heating versus metal temperature is carried out. During the isothermal electromigration test, the Joule heating is continuously monitored and the chuck temperature is adjusted based on the calibration results to maintain a constant metal temperature. In the second method, temperature sensors are fabricated on the chip and then the sensors are used to monitor the chip temperature directly. The chuck temperature is then adjusted as needed.

  7. A Multi-Level Systems Perspective for the Science of Team Science

    PubMed Central

    Brner, Katy; Contractor, Noshir; Falk-Krzesinski, Holly J.; Fiore, Stephen M.; Hall, Kara L.; Keyton, Joann; Spring, Bonnie; Stokols, Daniel; Trochim, William; Uzzi, Brian

    2012-01-01

    This Commentary describes recent research progress and professional developments in the study of scientific teamwork, an area of inquiry termed the science of team science (SciTS, pronounced sahyts). It proposes a systems perspective that incorporates a mixed-methods approach to SciTS that is commensurate with the conceptual, methodological, and translational complexities addressed within the SciTS field. The theoretically grounded and practically useful framework is intended to integrate existing and future lines of SciTS research to facilitate the fields evolution as it addresses key challenges spanning macro, meso, and micro levels of analysis. PMID:20844283

  8. A multi-level systems perspective for the science of team science.

    PubMed

    Brner, Katy; Contractor, Noshir; Falk-Krzesinski, Holly J; Fiore, Stephen M; Hall, Kara L; Keyton, Joann; Spring, Bonnie; Stokols, Daniel; Trochim, William; Uzzi, Brian

    2010-09-15

    This Commentary describes recent research progress and professional developments in the study of scientific teamwork, an area of inquiry termed the "science of team science" (SciTS, pronounced "sahyts"). It proposes a systems perspective that incorporates a mixed-methods approach to SciTS that is commensurate with the conceptual, methodological, and translational complexities addressed within the SciTS field. The theoretically grounded and practically useful framework is intended to integrate existing and future lines of SciTS research to facilitate the field's evolution as it addresses key challenges spanning macro, meso, and micro levels of analysis. PMID:20844283

  9. A Reliable Energy-Efficient Multi-Level Routing Algorithm for Wireless Sensor Networks Using Fuzzy Petri Nets

    PubMed Central

    Yu, Zhenhua; Fu, Xiao; Cai, Yuanli; Vuran, Mehmet C.

    2011-01-01

    A reliable energy-efficient multi-level routing algorithm in wireless sensor networks is proposed. The proposed algorithm considers the residual energy, number of the neighbors and centrality of each node for cluster formation, which is critical for well-balanced energy dissipation of the network. In the algorithm, a knowledge-based inference approach using fuzzy Petri nets is employed to select cluster heads, and then the fuzzy reasoning mechanism is used to compute the degree of reliability in the route sprouting tree from cluster heads to the base station. Finally, the most reliable route among the cluster heads can be constructed. The algorithm not only balances the energy load of each node but also provides global reliability for the whole network. Simulation results demonstrate that the proposed algorithm effectively prolongs the network lifetime and reduces the energy consumption. PMID:22163802

  10. Compact Verilog-A model of phase-change RAM transient behaviors for multi-level applications

    NASA Astrophysics Data System (ADS)

    Jung, Chul-Moon; Lee, Eun-Sub; Min, Kyeong-Sik; (Steve Kang, Sung-Mo

    2011-10-01

    A new phase-change RAM (PCRAM) model is proposed in this paper for multi-level-cell (MLC) applications. The proposed model has been verified to reproduce the electrical behaviors well in various partial states. Moreover, it has been shown that the programming transient behaviors with various quenching times could be estimated using the proposed model. The new unified PCRAM model which describes three different regions of PCRAM with only one equation has three times smaller discrepancy between the model and measurement than the previous piecewise linear model. For the continuity in PCRAM resistance, the new model shows smooth transition at the boundaries between different regions, whereas some abrupt changes in PCRAM resistance were found in the piecewise model. The compactness with the simple parameter extraction, the continuity for the reliable simulation and the accuracy in the negative differential resistance region make the proposed model useful and suitable in developing the future MLC PCRAM circuits.

  11. Multi-level detection of toxic stress in the mudpuppy (amphibian, salamander)

    SciTech Connect

    Gendron, A.D.; Fortin, R.; Hontela, A.; Bishop, C.A.; Van Der Kraak, G.

    1994-12-31

    Worldwide reports of declining amphibian populations highlight the need for ecotoxicological research on amphibians. The authors have investigated the response to toxic stress in the mudpuppy. Sites (N = 9) along mixed pollution gradients in the St. Lawrence/Ottawa Rivers systems were sampled on two consecutive winters (1992-93). Elevated concentrations of organochlorine pesticides, PCBs, and PCDFs detected in female gonads at the most contaminated sites, led the investigation toward signs of reproductive dysfunction. High levels of skeletal deformities were observed in the most polluted group where mudpuppies were found significantly more at risk to develop limb defects than at the reference site. The frequencies of terata, including oligodactyly and polydactyly, significantly increased with the intensity of exposure to recognized teratogens, in the St. Lawrence River system. The finding of deformities in adults could signal a more important impact during early life stages. The shift toward older t the most impacted site suggest a decrease in recruitment, that is consistent with lower survival of embryos developing under a toxic stress. Among site differences in other indicators of reproductive performance such as fecundity, gonado-somatic indices, circulating levels of 17{beta}-estradiol, testosterone, and corticosterone in females with vitellogenic eggs, were not detected.

  12. Light-Enhanced Fluorescence of Multi-Level Cavitands Possessing Pyridazine Upper rim.

    PubMed

    Janosi, Tibor Zoltan; Makkai, Geza; Kegl, Timea; Matyus, Peter; Kollar, Laszlo; Erostyak, Janos

    2016-03-01

    Completely different fluorescence behaviour of cavitands based on a same calix[4]resorcinarene compound was observed. While the fluorescence intensity of the parent compound, tetramethyl-cavitand (1) slowly faded as a result of UV-light exposure, the emission of the three-level cavitand with pyridazine moieties at the upper rim (5a) was enhanced by the excitation in the UV-region. The structure of fluorescence emission (characterized by excitation-emission matrices) and the absorption of 5a remained unaltered. The analysis of fluorescence decay curves reveals the presence of two separated components assigned to two individual emitting species. The measured significant increase of the average lifetime and quantum yield is the consequence of the UV-light induced transition between the different states of 5a. These observations can be explained by the structural difference between 5a and 1. As a counterpart of the naked cavitand (1) with methyl substituents at the upper rim only, 5a has three additional moieties benzene, triazole and pyridazine levels. Computational studies proved the existence of two conformational isomers of 5a. Upon ultraviolet light excitation a "dark" to "light" conformational transition occurs between the two isomers. This hypothesis was confirmed by anisotropy decay measurements. PMID:26715516

  13. Non-stationary return levels of CMIP5 multi-model temperature extremes

    NASA Astrophysics Data System (ADS)

    Cheng, Linyin; Phillips, Thomas J.; AghaKouchak, Amir

    2015-05-01

    The objective of this study is to evaluate to what extent the CMIP5 climate model simulations of the climate of the twentieth century can represent observed warm monthly temperature extremes under a changing environment. The biases and spatial patterns of 2-, 10-, 25-, 50- and 100-year return levels of the annual maxima of monthly mean temperature (hereafter, annual temperature maxima) from CMIP5 simulations are compared with those of Climatic Research Unit (CRU) observational data considered under a non-stationary assumption. The results show that CMIP5 climate models collectively underestimate the mean annual maxima over arid and semi-arid regions that are most subject to severe heat waves and droughts. Furthermore, the results indicate that most climate models tend to underestimate the historical annual temperature maxima over the United States and Greenland, while generally disagreeing in their simulations over cold regions. Return level analysis shows that with respect to the spatial patterns of the annual temperature maxima, there are good agreements between the CRU observations and most CMIP5 simulations. However, the magnitudes of the simulated annual temperature maxima differ substantially across individual models. Discrepancies are generally larger over higher latitudes and cold regions.

  14. Theoretical investigation of the oceanic inverted barometer response

    NASA Technical Reports Server (NTRS)

    Dickman, S. R.

    1988-01-01

    Dynamic tidal theory is generalized in order to predict the oceanic response to atmospheric pressure variations. The oceans are found to exhibit distinct dynamic behavior when forced at periods less than one week; depending on the harmonic type of forcing, the amplitude of the response can differ by about 20 percent or more from the static response. Even at roughly two months the traditional 'inverted barometer' may not be sufficiently accurate for applications in which detection of long-term sea level trends or vertical crustal motion is the goal. For forcing at periods of order one year the oceanic response differs by at most a few percent from the static (not the inverted barometer) response; thus calculations of meteorological excitation of the annual and Chandler wobbles can employ the static approximation without reservation.

  15. Integrated Inverter For Driving Multiple Electric Machines

    DOEpatents

    Su, Gui-Jia [Knoxville, TN; Hsu, John S [Oak Ridge, TN

    2006-04-04

    An electric machine drive (50) has a plurality of inverters (50a, 50b) for controlling respective electric machines (57, 62), which may include a three-phase main traction machine (57) and two-phase accessory machines (62) in a hybrid or electric vehicle. The drive (50) has a common control section (53, 54) for controlling the plurality of inverters (50a, 50b) with only one microelectronic processor (54) for controlling the plurality of inverters (50a, 50b), only one gate driver circuit (53) for controlling conduction of semiconductor switches (S1-S10) in the plurality of inverters (50a, 50b), and also includes a common dc bus (70), a common dc bus filtering capacitor (C1) and a common dc bus voltage sensor (67). The electric machines (57, 62) may be synchronous machines, induction machines, or PM machines and may be operated in a motoring mode or a generating mode.

  16. Inverted organic electronic and optoelectronic devices

    NASA Astrophysics Data System (ADS)

    Small, Cephas E.

    The research and development of organic electronics for commercial application has received much attention due to the unique properties of organic semiconductors and the potential for low-cost high-throughput manufacturing. For improved large-scale processing compatibility and enhanced device stability, an inverted geometry has been employed for devices such as organic light emitting diodes and organic photovoltaic cells. These improvements are attributed to the added flexibility to incorporate more air-stable materials into the inverted device geometry. However, early work on organic electronic devices with an inverted geometry typically showed reduced device performance compared to devices with a conventional structure. In the case of organic light emitting diodes, inverted devices typically show high operating voltages due to insufficient carrier injection. Here, a method for enhancing hole injection in inverted organic electronic devices is presented. By incorporating an electron accepting interlayer into the inverted device, a substantial enhancement in hole injection efficiency was observed as compared to conventional devices. Through a detailed carrier injection study, it is determined that the injection efficiency enhancements in the inverted devices are due to enhanced charge transfer at the electron acceptor/organic semiconductor interface. A similar situation is observed for organic photovoltaic cells, in which devices with an inverted geometry show limited carrier extraction in early studies. In this work, enhanced carrier extraction is demonstrated for inverted polymer solar cells using a surface-modified ZnO-polymer composite electron-transporting layer. The insulating polymer in the composite layer inhibited aggregation of the ZnO nanoparticles, while the surface-modification of the composite interlayer improved the electronic coupling with the photoactive layer. As a result, inverted polymer solar cells with power conversion efficiencies of over 8% were obtained. To further study carrier extraction in inverted polymer solar cells, the active layer thickness dependence of the efficiency was investigated. For devices with active layer thickness < 200 nm, power conversion efficiencies over 8% was obtained. This result is important for demonstrating improved large-scale processing compatibility. Above 200 nm, significant reduction in cell efficiency were observed. A detailed study of the loss processes that contributed to the reduction in efficiency for thick-film devices are presented.

  17. Multi-Level Models of Internalizing Disorders and Translational Developmental Science: Seeking Etiological Insights that can Inform Early Intervention Strategies.

    PubMed

    Allen, Nicholas B; Dahl, Ronald E

    2015-07-01

    This commentary discusses the articles in this special section with an emphasis on the specific utility of multivariate, multi-level models in developmental psychopathology for ultimately contributing to both etiologic insights and translational advances. These issues are considered not only in terms of the specific papers, but also within a larger set of questions regarding the opportunities (and challenges) currently facing the field. We describe why we believe this an exciting time for integrative team-science approaches to tackle these challenges--a time that holds great promise for rapid advances in integrative developmental science that includes a biological level of mechanistic understanding. In order to facilitate this, we outline a range of approaches within both translational neuroscience and translational developmental science that can be used as frameworks for understanding how such research can provide etiologic insights regarding real-world targets at the level of social, behavioral, and affective processes that can be modified during key developmental windows of opportunity. We conclude that a "construct validity" framework, where biological data form a critical, but not privileged, component of key etiological mechanisms, combined with a developmental perspective on key period of sensitivity to intervention effects, is most likely to provide significant translational outcomes. PMID:25947071

  18. Critical Infrastructures as Complex Systems: A Multi-level Protection Architecture

    NASA Astrophysics Data System (ADS)

    Assogna, Pierluigi; Bertocchi, Glauco; Dicarlo, Antonio; Milicchio, Franco; Paoluzzi, Alberto; Scorzelli, Giorgio; Vicentino, Michele; Zollo, Roberto

    This paper describes a security platform as a complex system of holonic communities, that are hierarchically organized, but self-reconfigurable when some of them are detached or cannot otherwise operate. Furthermore, every possible subset of holons may work autonomously, while maintaining self-conscience of its own mission, action lines and goals. Each holonic unit, either elementary or composite, retains some capabilities for sensing (perception), transmissive apparatus (communication), computational processes (elaboration), authentication/authorization (information security), support for data exchange (visualization & interaction), actuators (mission), ambient representation (geometric reasoning), knowledge representation (logic reasoning), situation representation and forecasting (simulation), intelligent feedback (command & control). The higher the organizational level of the holonic unit, the more complex and sophisticated each of its characteristic features.

  19. Wafer-level fabrication of multi-element glass lenses: lens doublet with improved optical performances.

    PubMed

    Albero, Jorge; Perrin, Stéphane; Passilly, Nicolas; Krauter, Johann; Gauthier-Manuel, Ludovic; Froehly, Luc; Lullin, Justine; Bargiel, Sylwester; Osten, Wolfgang; Gorecki, Christophe

    2016-01-01

    This Letter reports on the fabrication of glass lens doublets arranged in arrays and realized at wafer level by means of micro-fabrication. The technique is based on the accurate vertical assembly of separately fabricated glass lens arrays. Since each one of these arrays is obtained by glass melting in silicon cavities, silicon is employed as a spacer in order to build a well-aligned and robust optical module. It is shown that optical performance achieved by the lens doublet is better than for a single lens of equivalent numerical aperture, thanks to lower optical aberrations. The technique has good potential to match the optical requirements of miniature imaging systems. PMID:26696167

  20. Stepping up ELISpot: Multi-Level Analysis in FluoroSpot Assays.

    PubMed

    Janetzki, Sylvia; Rueger, Markus; Dillenbeck, Tomas

    2014-01-01

    ELISpot is one of the most commonly used immune monitoring assays, which allows the functional assessment of the immune system at the single cell level. With its outstanding sensitivity and ease of performance, the assay has recently advanced from the mere single function cell analysis to multifunctional analysis by implementing detection reagents that are labeled with fluorophores (FluoroSpot), allowing the detection of secretion patterns of two or more analytes in a single well. However, the automated evaluation of such assays presents various challenges for image analysis. Here we dissect the technical and methodological requirements for a reliable analysis of FluoroSpot assays, introduce important quality control measures and provide advice for proper interpretation of results obtained by automated imaging systems. PMID:25437440

  1. Efficient Multi-Level Modeling and Monitoring of End-use Energy Profile in Commercial Buildings

    NASA Astrophysics Data System (ADS)

    Kang, Zhaoyi

    In this work, modeling and monitoring of end-use power consumption in commercial buildings are investigated through both Top-Down and Bottom-Up approaches. In the Top-Down approach, an adaptive support vector regression (ASVR) model is developed to accommodate the nonlinearity and nonstationarity of the macro-level time series, thus providing a framework for the modeling and diagnosis of end-use power consumption. In the Bottom-Up approach, an appliance-data-driven stochastic model is built to predict each end-use sector of a commercial building. Power disaggregation is studied as a technique to facilitate Bottom-Up prediction. In Bottom-Up monitoring and diagnostic detection, a new dimensionality reduction technique is explored to facilitate the analysis of multivariate binary behavioral signals in building end-uses.

  2. Probing single- to multi-cell level charge transport in Geobacter sulfurreducens DL-1.

    PubMed

    Jiang, Xiaocheng; Hu, Jinsong; Petersen, Emily R; Fitzgerald, Lisa A; Jackan, Charles S; Lieber, Alexander M; Ringeisen, Bradley R; Lieber, Charles M; Biffinger, Justin C

    2013-01-01

    Microbial fuel cells, in which living microorganisms convert chemical energy into electricity, represent a potentially sustainable energy technology for the future. Here we report the single-bacterium level current measurements of Geobacter sulfurreducens DL-1 to elucidate the fundamental limits and factors determining maximum power output from a microbial fuel cell. Quantized stepwise current outputs of 92(33) and 196(20)?fA are generated from microelectrode arrays confined in isolated wells. Simultaneous cell imaging/tracking and current recording reveals that the current steps are directly correlated with the contact of one or two cells with the electrodes. This work establishes the amount of current generated by an individual Geobacter cell in the absence of a biofilm and highlights the potential upper limit of microbial fuel cell performance for Geobacter in thin biofilms. PMID:24202068

  3. Clanistics: a multi-level perspective for harvesting unrooted gene trees.

    PubMed

    Lapointe, Franois-Joseph; Lopez, Philippe; Boucher, Yan; Koenig, Jeremy; Bapteste, Eric

    2010-08-01

    Prokaryotic evolution takes place within and between genomes, when significant amounts of genes are transferred and recombined between interacting genetic partners. These non-tree-like evolutionary processes, intertwined with events of vertical descent, lead to a massive production of unrooted trees in which branches, nodes and groupings have different biological meanings than for the rooted trees usually studied by phylogenetics. Such unrooted gene trees can not only inform us about organismal phylogeny, but also about the variety of evolutionary, genetic, functional and ecological relationships affecting a plurality of evolutionary units, at multiple levels - from genes, groups of genes, organisms and consortia, to communities. Here we introduce new notions designed to analyze unrooted trees with more depth and accuracy. We demonstrate how a clanistic perspective can significantly improve our knowledge of evolutionary processes and relationships for most evolving systems, whether they are mobile genetic elements or cellular genomes. PMID:20605718

  4. On the capability of deep level transient spectroscopy for characterizing multi-crystalline silicon

    SciTech Connect

    Mchedlidze, T.; Nacke, M.; Hieckmann, E.; Weber, J.

    2014-01-07

    The suitability of the deep level transient spectroscopy (DLTS) technique in exploring locations with high and degraded carrier lifetimes containing grain-boundaries (GBs) in multicrystalline silicon (mc-Si) wafers was studied. The types and locations of GBs were determined in mc-Si samples by electron backscatter diffraction. Mesa-type Schottky diodes were prepared at (along) GBs and at reference, GB-free locations. Detected DLTS signals varied strongly along the same GB. Experiments with dislocation networks, model structures for GBs, showed that GB-related traps may be explored only using special arrangement of a GB and the diode contacts. Iron-related carrier traps were detected in locations with degraded carrier lifetimes. Densities of the traps for near-GB and for GB free locations were compared to the lifetime measurement results.

  5. Ultra-Compact Transputer-Based Controller for High-Level, Multi-Axis Coordination

    NASA Technical Reports Server (NTRS)

    Zenowich, Brian; Crowell, Adam; Townsend, William T.

    2013-01-01

    The design of machines that rely on arrays of servomotors such as robotic arms, orbital platforms, and combinations of both, imposes a heavy computational burden to coordinate their actions to perform coherent tasks. For example, the robotic equivalent of a person tracing a straight line in space requires enormously complex kinematics calculations, and complexity increases with the number of servo nodes. A new high-level architecture for coordinated servo-machine control enables a practical, distributed transputer alternative to conventional central processor electronics. The solution is inherently scalable, dramatically reduces bulkiness and number of conductor runs throughout the machine, requires only a fraction of the power, and is designed for cooling in a vacuum.

  6. Stepping up ELISpot: Multi-Level Analysis in FluoroSpot Assays

    PubMed Central

    Janetzki, Sylvia; Rueger, Markus; Dillenbeck, Tomas

    2014-01-01

    ELISpot is one of the most commonly used immune monitoring assays, which allows the functional assessment of the immune system at the single cell level. With its outstanding sensitivity and ease of performance, the assay has recently advanced from the mere single function cell analysis to multifunctional analysis by implementing detection reagents that are labeled with fluorophores (FluoroSpot), allowing the detection of secretion patterns of two or more analytes in a single well. However, the automated evaluation of such assays presents various challenges for image analysis. Here we dissect the technical and methodological requirements for a reliable analysis of FluoroSpot assays, introduce important quality control measures and provide advice for proper interpretation of results obtained by automated imaging systems. PMID:25437440

  7. Multi-level security for computer networking: SAC digital network approach

    SciTech Connect

    Griess, W.; Poutre, D.L.

    1983-10-01

    For telecommunications systems simultaneously handling data of different security levels, multilevel secure (MLS) operation permits maximum use of resources by automatically providing protection to users with various clearances and needs-to-know. The strategic air command (SAC) is upgrading the primary record data system used to command and control its strategic forces. The upgrade, called the SAC Digital Network (SACDIN), is designed to provide multilevel security to support users and external interfaces, with allowed accesses ranging from unclassified to top secret. SACDIN implements a security kernel based upon the Bell and Lapadula security model. This study presents an overview of the SACDIN security architecture and describes the basic message flow across the MLS network. 7 references.

  8. Numerical Simulation of Rolling-Airframes Using a Multi-Level Cartesian Method

    NASA Technical Reports Server (NTRS)

    Murman, Scott M.; Aftosmis, Michael J.; Berger, Marsha J.; Kwak, Dochan (Technical Monitor)

    2002-01-01

    A supersonic rolling missile with two synchronous canard control surfaces is analyzed using an automated, inviscid, Cartesian method. Sequential-static and time-dependent dynamic simulations of the complete motion are computed for canard dither schedules for level flight, pitch, and yaw maneuver. The dynamic simulations are compared directly against both high-resolution viscous simulations and relevant experimental data, and are also utilized to compute dynamic stability derivatives. The results show that both the body roll rate and canard dither motion influence the roll-averaged forces and moments on the body. At the relatively, low roll rates analyzed in the current work these dynamic effects are modest, however the dynamic computations are effective in predicting the dynamic stability derivatives which can be significant for highly-maneuverable missiles.

  9. Reciprocal Psychological Aggression in Couples: A Multi-Level Analysis in a Community Sample.

    PubMed

    Cuenca Montesino, Mara Luisa; Graa Gmez, Jos Luis; Martnez Arias, Rosario

    2015-09-01

    The present study analyzes reciprocal psychological aggression assessed by the Conflict Tactics Scale-Revised (CTS-2) in a sample of 590 adult couples from the Region of Madrid. Psychological aggression is the most frequent form of partner aggression. Results showed high percentages of psychological aggression perpetrated and suffered in men and women and showed significant statistical differences in severe psychological aggression in the case of women. Partner agreement about acts of psychological aggression was significant, albeit at moderate levels. Generalized Hierarchical Linear Models with the HLM-6.0 program were proposed to examine reciprocal psychological aggression. The models confirmed the pattern of reciprocal psychological aggression and also that couples are more aggressive when they are younger. Duration of cohabitation was not a predictor of reciprocal psychological partner aggression. PMID:25315486

  10. Tight Interconnection and Multi-Level Control of Arabidopsis MYB44 in MAPK Cascade Signalling

    PubMed Central

    2013-01-01

    Abiotic stress poses a huge, ever-increasing problem to plants and agriculture. The dissection of signalling pathways mediating stress tolerance is a prerequisite to develop more resistant plant species. Mitogen-activated protein kinase (MAPK) cascades are universal signalling modules. In Arabidopsis, the MAPK MPK3 and its upstream regulator MAPK kinase MKK4 initiate the adaptation response to numerous abiotic and biotic stresses. Yet, molecular steps directly linked with MKK4 – MPK3 activation are largely unknown. Starting with a yeast-two-hybrid screen for interacting partners of MKK4, we identified a transcription factor, MYB44. MYB44 is controlled at multiple levels by and strongly inter-connected with MAPK signalling. As we had shown earlier, stress-induced expression of the MYB44 gene is regulated by a MPK3-targeted bZIP transcription factor VIP1. At the protein level, MYB44 interacts with MPK3 in vivo. MYB44 is phosphorylated by MPK3 in vitro at a single residue, Ser145. Although replacement of Ser145 by a non-phosphorylatable (S145A) or phosphomimetic (S145D) residue did not alter MYB44 subcellular localisation, dimerization behaviour nor DNA-binding characteristics, abiotic stress tolerance tests in stable transgenic Arabidopsis plants clearly related S145 phosphorylation to MYB44 function: Compared to Arabidopsis wild type plants, MYB44 overexpressing lines exhibit an enhanced tolerance to osmotic stress and are slightly more sensitive to abscisic acid. Interestingly, overexpression of the S145A variant revealed that impaired phosphorylation does not render the MYB44 protein non-functional. Instead, S145A lines are highly sensitive to abiotic stress, and thereby remarkably similar to mpk3-deficient plants. Its in vivo interaction with the nuclear sub-pools of both MPK3 and MKK4 renders MYB44 the first plant transcription factor to have a second function as putative MAPK cascade scaffolding protein. PMID:23437396

  11. A multi-level study of recombinant Pichia pastoris in different oxygen conditions

    PubMed Central

    2010-01-01

    Background Yeasts are attractive expression platforms for many recombinant proteins, and there is evidence for an important interrelation between the protein secretion machinery and environmental stresses. While adaptive responses to such stresses are extensively studied in Saccharomyces cerevisiae, little is known about their impact on the physiology of Pichia pastoris. We have recently reported a beneficial effect of hypoxia on recombinant Fab secretion in P. pastoris chemostat cultivations. As a consequence, a systems biology approach was used to comprehensively identify cellular adaptations to low oxygen availability and the additional burden of protein production. Gene expression profiling was combined with proteomic analyses and the 13C isotope labelling based experimental determination of metabolic fluxes in the central carbon metabolism. Results The physiological adaptation of P. pastoris to hypoxia showed distinct traits in relation to the model yeast S. cerevisiae. There was a positive correlation between the transcriptomic, proteomic and metabolic fluxes adaptation of P. pastoris core metabolism to hypoxia, yielding clear evidence of a strong transcriptional regulation component of key pathways such as glycolysis, pentose phosphate pathway and TCA cycle. In addition, the adaptation to reduced oxygen revealed important changes in lipid metabolism, stress responses, as well as protein folding and trafficking. Conclusions This systems level study helped to understand the physiological adaptations of cellular mechanisms to low oxygen availability in a recombinant P. pastoris strain. Remarkably, the integration of data from three different levels allowed for the identification of differences in the regulation of the core metabolism between P. pastoris and S. cerevisiae. Detailed comparative analysis of the transcriptomic data also led to new insights into the gene expression profiles of several cellular processes that are not only susceptible to low oxygen concentrations, but might also contribute to enhanced protein secretion. PMID:20969759

  12. What's Driving You Crazy? A Question To Drive Collaborative, Inquiry-Based Middle School Reform. Part II: Private and Multi-Level Schools.

    ERIC Educational Resources Information Center

    Deering, Paul D.; And Others

    2003-01-01

    Describes how the question "What's driving you crazy?" is used by Hawaii middle-level educators to improve working conditions and meet students' needs by making schools more developmentally responsive. Focuses on the 6-step collaborative, inquiry-based innovation process at two private, multi-level schools embedded within K-8 or 6-12 campuses.

  13. Automatic load sharing in inverter modules

    NASA Technical Reports Server (NTRS)

    Nagano, S.

    1979-01-01

    Active feedback loads transistor equally with little power loss. Circuit is suitable for balancing modular inverters in spacecraft, computer power supplies, solar-electric power generators, and electric vehicles. Current-balancing circuit senses differences between collector current for power transistor and average value of load currents for all power transistors. Principle is effective not only in fixed duty-cycle inverters but also in converters operating at variable duty cycles.

  14. Base drive for paralleled inverter systems

    NASA Technical Reports Server (NTRS)

    Nagano, S. (inventor)

    1980-01-01

    In a paralleled inverter system, a positive feedback current derived from the total current from all of the modules of the inverter system is applied to the base drive of each of the power transistors of all modules, thereby to provide all modules protection against open or short circuit faults occurring in any of the modules, and force equal current sharing among the modules during turn on of the power transistors.

  15. Work Station For Inverting Solar Cells

    NASA Technical Reports Server (NTRS)

    Feder, H.; Frasch, W.

    1982-01-01

    Final work station along walking-beam conveyor of solar-array assembly line turns each pretabbed solar cell over, depositing it back-side-up onto landing pad, which centers cell without engaging collector surface. Solar cell arrives at inverting work station collector-side-up with two interconnect tabs attached to collector side. Cells are inverted so that second soldering operation takes place in plain view of operator. Inversion protects collector from damage when handled at later stages of assembly.

  16. Multi-level phase change memory devices with Ge2Sb2Te5 layers separated by a thermal insulating Ta2O5 barrier layer

    NASA Astrophysics Data System (ADS)

    Gyanathan, Ashvini; Yeo, Yee-Chia

    2011-12-01

    This work investigates multi-level phase change random access memory (PCRAM) devices comprising two Ge2Sb2Te5 (GST) layers sandwiching a thermal insulating Ta2O5 barrier layer. The PCRAM cell comprises a phase change material stack between a top and a bottom electrode. The phase change material stack comprises a nitrogen doped GST (NGST) layer on a thin Ta2O5 barrier layer on an undoped GST layer. It is demonstrated that one of the phase change layers in the GST stack can be selectively amorphized by using a voltage pulse. This enables multi-level resistance switching. The differences in resistivities, as well as the different melting and crystallization temperatures of both the NGST and GST layers, contribute to the multi-level switching dynamics of the PCRAM device. The thermal conductivity of Ta2O5 with respect to GST is also another factor influencing the multi-level switching. Extensive electrical characterization of the PCRAM devices was performed. Thermal analysis was used to examine the physics behind the multi-level switching mechanism of these devices.

  17. Multi-level assessment of chronic toxicity of estuarine sediments with the amphipod Gammarus locusta: II. Organism and population-level endpoints.

    PubMed

    Costa, Filipe O; Neuparth, Teresa; Correia, Ana D; Costa, Maria Helena

    2005-07-01

    This study aimed to test the performance of the amphipod Gammarus locusta (L.) in chronic sediment toxicity tests. It constitutes part of a multi-level assessment of chronic toxicity of estuarine sediments, integrating organism and population-level endpoints with biochemical markers responses. Here we account for organism and population-level effects, while biomarker responses were reported in a companion article. Five moderately contaminated sediments from Sado and Tagus estuaries were tested, comprising 3 muddy and 2 sandy sediments. These sediments either did not show acute toxicity or were diluted with control sediment as much as required to remove acute toxicity. Subsequent chronic tests consisted of 28-day exposures with survival, individual growth and reproductive traits as endpoints. Two of the muddy sediments induced higher growth rates in the amphipods, and improved reproductive traits. This was understood to be a consequence of the amount of organic matter in the sediment, which was nutritionally beneficial to the amphipods, while concurrently decreasing contaminant bioavailability. Biomarker responses did not reveal toxicant-induced stress in amphipods exposed to these sediments. One of the sandy sediments was acutely toxic at 50% dilution, but in contrast stimulated amphipod growth when diluted 75%. This was presumed to be an indication of a hormetic response. Finally the two remaining contaminated sediments showed pronounced chronic toxicity, affecting survival and reproduction. The sex ratio of survivors was highly biased towards females, and offspring production was severely impaired. The particulars of the responses of this amphipod were examined, as well as strengths versus limitations of the sediment test. This study illustrates the utility of this chronic test for toxicity assessment of contaminated estuarine sediments, with potential application all along Atlantic Europe. PMID:15649529

  18. The fourth level of social structure in a multi-level society: ecological and social functions of clans in hamadryas baboons.

    PubMed

    Schreier, Amy L; Swedell, Larissa

    2009-11-01

    Hamadryas baboons are known for their complex, multi-level social structure consisting of troops, bands, and one-male units (OMUs) [Kummer, 1968. Social organization of hamadryas baboons. Chicago: The University of Chicago Press. 189p]. Abegglen [1984. On socialization in hamadryas baboons: a field study. Lewisburg, PA: Bucknell University Press. 207p.] observed a fourth level of social structure comprising several OMUs that rested near one another on sleeping cliffs, traveled most closely together during daily foraging, and sometimes traveled as subgroups independently from the rest of the band. Abegglen called these associations "clans" and suggested that they consisted of related males. Here we confirm the existence of clans in a second wild hamadryas population, a band of about 200 baboons at the Filoha site in lowland Ethiopia. During all-day follows from December 1997 through September 1998 and March 2005 through February 2006, data were collected on activity patterns, social interactions, nearest neighbors, band fissions, and takeovers. Association indices were computed for each dyad of leader males, and results of cluster analyses indicated that in each of the two observation periods this band comprised two large clans ranging in size from 7 to 13 OMUs. All band fissions occurred along clan lines, and most takeovers involved the transfer of females within the same clan. Our results support the notion that clans provide an additional level of flexibility to deal with the sparse distribution of resources in hamadryas habitats. The large clan sizes at Filoha may simply be the largest size that the band can split into and still obtain enough food during periods of food scarcity. Our results also suggest that both male and female relationships play a role in the social cohesion of clans and that males exchange females within clans but not between them. PMID:19670312

  19. Real-time multi-step-ahead water level forecasting by recurrent neural networks for urban flood control

    NASA Astrophysics Data System (ADS)

    Chang, Fi-John; Chen, Pin-An; Lu, Ying-Ray; Huang, Eric; Chang, Kai-Yao

    2014-09-01

    Urban flood control is a crucial task, which commonly faces fast rising peak flows resulting from urbanization. To mitigate future flood damages, it is imperative to construct an on-line accurate model to forecast inundation levels during flood periods. The Yu-Cheng Pumping Station located in Taipei City of Taiwan is selected as the study area. Firstly, historical hydrologic data are fully explored by statistical techniques to identify the time span of rainfall affecting the rise of the water level in the floodwater storage pond (FSP) at the pumping station. Secondly, effective factors (rainfall stations) that significantly affect the FSP water level are extracted by the Gamma test (GT). Thirdly, one static artificial neural network (ANN) (backpropagation neural network-BPNN) and two dynamic ANNs (Elman neural network-Elman NN; nonlinear autoregressive network with exogenous inputs-NARX network) are used to construct multi-step-ahead FSP water level forecast models through two scenarios, in which scenario I adopts rainfall and FSP water level data as model inputs while scenario II adopts only rainfall data as model inputs. The results demonstrate that the GT can efficiently identify the effective rainfall stations as important inputs to the three ANNs; the recurrent connections from the output layer (NARX network) impose more effects on the output than those of the hidden layer (Elman NN) do; and the NARX network performs the best in real-time forecasting. The NARX network produces coefficients of efficiency within 0.9-0.7 (scenario I) and 0.7-0.5 (scenario II) in the testing stages for 10-60-min-ahead forecasts accordingly. This study suggests that the proposed NARX models can be valuable and beneficial to the government authority for urban flood control.

  20. Sea level change in the Gulf of Thailand from GPS-corrected tide gauge data and multi-satellite altimetry

    NASA Astrophysics Data System (ADS)

    Trisirisatayawong, Itthi; Naeije, Marc; Simons, Wim; Fenoglio-Marc, Luciana

    2011-04-01

    Investigation of long-term tidal data and short-term altimetry measurements reveals that sea level in the Gulf of Thailand is rising significantly faster than global average rates. Upward land motion detected from repeated precise GPS campaign measurements is used to correct the apparent sea level change from tide gauge, yielding absolute long-term trends as follows: Sattahip (1942-2004) 5.0 1.3 mm/yr, Ko Sichang (1940-1999) 4.5 1.3 mm/yr and Ko Mattaphon (1964-2004) 4.4 1.1 mm/yr. Dual-crossover minimization of multi-mission altimetry data covering the 1993-2009 period reveals the following absolute sea level rates: Sattahip 4.8 0.7 mm/yr, Ko Sichang 5.8 0.8 mm/yr, Ko Lak 3.6 0.7 mm/yr and Ko Mattaphon 3.2 0.7 mm/yr. In other parts of the Gulf, the 1993-2009 rising rates are also in the range of 3 to 5.5 mm/yr. In the entire Gulf we don't find any evidence of sea level falling. At Ko Lak where the collocation of Topex-class altimetry ground track and the tidal station is extremely good, vertical land motion derived from the difference of sea level change rates detected by altimetry and tidal data is used to correct the apparent rate, yielding an absolute long-term (1940-2004) rate of 3.0 1.5 mm/yr. The differences between the altimetry-based rates and the absolute tide gauge sea level trends can be explained by interannual variations like ENSO and decadal variations due to solar activity and lunar nutation. Post-2004 tidal data have been treated separately in our study because reliable values of region-wide vertical co-seismic displacements and post-seismic velocities caused by the 2004 Mw9.2 Sumatra-Andaman earthquake are still not accurately known. Exclusion of these data will not significantly change the determined long-term absolute sea level change rates because of the relatively short time span of post-earthquake sea level data compared to the complete tidal record. The impact of fast rising sea level combined with high rates of post-seismic downward crustal motions as indicated by GPS data makes coastal areas and river estuaries along the Gulf of Thailand highly vulnerable to flooding, particularly the low-lying city of Bangkok.