Comparison of two intelligent models to estimate the instantaneous ...
Indian Academy of Sciences (India)
Mostafa Zamani Mohiabadi
2017-07-25
Jul 25, 2017 ... 2014) has combined empirical models and a Bayesian neural network (BNN) model to estimate daily global solar radiation on a horizon- tal surface in Ghardaıa, Algeria. In their model, the maximum and minimum air temperatures of the year 2006 have been used to estimate the coefficients of the empirical ...
International Nuclear Information System (INIS)
Mahlman, J.D.; Moxim, W.J.
1978-01-01
An 11-level general circulation model with seasonal variation is used to perform an experiment on the dispersion of passive tracers. Specially constructed time-dependent winds from this model are used as input to a separate tracer model. The methodologies employed to construct the tracer model are described.The experiment presented is the evolution of a hypothetical instantaneous source of tracer on 1 Janaury with maximum initial concentration at 65 mb, 36 0 N, 180 0 E. The tracer is assumed to have no sources or sinks in the stratosphere, but is subject to removal processes in the lower troposphere.The experimental results reveal a number of similarities to observed tracer behavior, including the average poleward-downward slope of mixing ratio isopleths, strong tracer gradients across the tropopause, intrusion of tracer into the Southern Hemisphere lower stratosphere, and the long-term interhemispheric exchange rate. The model residence times show behavior intermediate to those exhibited for particulate radioactive debris and gaseous C 14 O 2 . This suggests that caution should be employed when either radioactive debris or C 14 O 2 data are used to develop empirical models for prediction of gaseous tracers which are efficiently removed in the troposphere.In this experiment, the tracer mixing ratio and potential vorticity evolve to very high correlations. Mechanisms for this correlation are discussed. The zonal mean tracer balances exhibit complex behavior among the various transport terms. At early stages, the tracer evolution is dominated by eddy effects. Later, a very large degree of self-cancellation between mean cell and eddy effects is observed. During seasonal transitions, however, this self-cancellation diminishes markedly, leading to significant changes in the zonal mean tracer distribution. A possible theoretical explanation is presented
Comparison of two intelligent models to estimate the instantaneous ...
Indian Academy of Sciences (India)
... they are 85.46 (w/m2), 3.08 (w/m2) and 5.41, respectively. As the results indicate, both models are able to estimate the amount of radiation well, while the neural network has a higher accuracy. The output of the modes for six other cities of Iran, with similar climate conditions, also proves the ability of the proposed models.
Valenza, Gaetano; Citi, Luca; Scilingo, Enzo Pasquale; Barbieri, Riccardo
2014-01-01
Measures of entropy have been proved as powerful quantifiers of complex nonlinear systems, particularly when applied to stochastic series of heartbeat dynamics. Despite the remarkable achievements obtained through standard definitions of approximate and sample entropy, a time-varying definition of entropy characterizing the physiological dynamics at each moment in time is still missing. To this extent, we propose two novel measures of entropy based on the inho-mogeneous point-process theory. The RR interval series is modeled through probability density functions (pdfs) which characterize and predict the time until the next event occurs as a function of the past history. Laguerre expansions of the Wiener-Volterra autoregressive terms account for the long-term nonlinear information. As the proposed measures of entropy are instantaneously defined through such probability functions, the proposed indices are able to provide instantaneous tracking of autonomic nervous system complexity. Of note, the distance between the time-varying phase-space vectors is calculated through the Kolmogorov-Smirnov distance of two pdfs. Experimental results, obtained from the analysis of RR interval series extracted from ten healthy subjects during stand-up tasks, suggest that the proposed entropy indices provide instantaneous tracking of the heartbeat complexity, also allowing for the definition of complexity variability indices.
Neutronic modeling for a Gas-cooled Fast Reactor assuming coated fuel particles
International Nuclear Information System (INIS)
Golfier, H.; Buiron, C.; Poinot, B.; Pothet, J. F.; Salavy, E.; Studer
2004-01-01
The modeling of gas cooled fast reactor (GCFR) with the SAPHYR system and in particular APOLLO2 code assuming coated fuel particles, was investigated. It aims to estimate the APOLLO2 code accuracy, solving the neutron transport equation in range of fast neutron reactors. A two level PIJ/SN APOLLO2 scheme is proposed in which the first level is devoted to the self-shielding and the leakage calculation on a cell configuration. The efficiency of a new treatment of adsorption and scattering rates in the self-shielding module of the multigroup transport code APOLLO2 has been evaluated. The results show that two-level scheme provides promising results with 172-group cross section libraries, which confirm the APOLLO2 scheme as a tool for reactor designs. (authors)
An All Sky Instantaneous Shortwave Solar Radiation Model for Mountainous Terrain
Zhang, S.; Li, X.; She, J.
2017-12-01
In mountainous terrain, solar radiation shows high heterogeneity in space and time because of strong terrain shading effects and significant variability of cloud cover. While existing GIS-based solar radiation models simulate terrain shading effects with relatively high accuracy and models based on satellite datasets consider fine scale cloud attenuation processes, none of these models have considered the geometrical relationships between sun, cloud, and terrain, which are important over mountainous terrain. In this research we propose sky cloud maps to represent cloud distribution in a hemispherical sky using MODIS cloud products. By overlaying skyshed (visible area in the hemispherical sky derived from DEM), sky map, and sky cloud maps, we are able to consider both terrain shading effects and anisotropic cloud attenuation in modeling instantaneous direct and diffuse solar radiation in mountainous terrain. The model is evaluated with field observations from three automatic weather stations in the Tizinafu watershed in the Kunlun Mountains of northwestern China. Overall, under all sky conditions, the model overestimates instantaneous global solar radiation with a mean absolute relative difference (MARD) of 22%. The model is also evaluated under clear sky (clearness index of more than 0.75) and partly cloudy sky (clearness index between 0.35 and 0.75) conditions with MARDs of 5.98% and 23.65% respectively. The MARD for very cloudy sky (clearness index less than 0.35) is relatively high. But these days occur less than 1% of the time. The model is sensitive to DEM data error, algorithms used in delineating skyshed, and errors in MODIS atmosphere and cloud products. Our model provides a novel approach for solar radiation modeling in mountainous areas.
Instantaneous thermal modeling of the DC-link capacitor in PhotoVoltaic systems
DEFF Research Database (Denmark)
Yang, Yongheng; Ma, Ke; Wang, Huai
2015-01-01
, instantaneous thermal modeling approaches considering mission profiles for the DC-link capacitor in single-phase PV systems are explored in this paper. These thermal modelling approaches are based on: a) fast Fourier transform, b) look-up tables, and c) ripple current reconstruction. Moreover, the thermal...... thermal loading from the operating conditions. As a consequence, it offers new insights into the temperature monitoring and reliability-oriented design of the DC-link capacitors, and thus a more reliable operation of single-phase grid-connected PV systems can be enhanced. Study results on a 3-kW single......-phase grid-connected PV system have been adopted to demonstrate a look-up table based modelling approach, where real-field daily ambient conditions are considered....
Tat, Roya; Allah Taleizadeh, Ata; Esmaeili, Maryam
2015-05-01
This paper develops an economic order quantity model for non-instantaneous deteriorating items with and without shortages to investigate the performance of the vendor-managed inventory (VMI) system. This model is developed for a two-level supply chain consisting of a single supplier and single retailer with a single non-instantaneous deteriorating item. A numerical example and sensitivity analysis are provided to illustrate how increasing or reducing the related parameters change the optimal values of the decision variables of the two proposed models. The results show that VMI works better and charges lower cost in all conditions.
Kamarianakis, Yiannis; Gao, H Oliver
2010-02-15
Collecting and analyzing high frequency emission measurements has become very usual during the past decade as significantly more information with respect to formation conditions can be collected than from regulated bag measurements. A challenging issue for researchers is the accurate time-alignment between tailpipe measurements and engine operating variables. An alignment procedure should take into account both the reaction time of the analyzers and the dynamics of gas transport in the exhaust and measurement systems. This paper discusses a statistical modeling framework that compensates for variable exhaust transport delay while relating tailpipe measurements with engine operating covariates. Specifically it is shown that some variants of the smooth transition regression model allow for transport delays that vary smoothly as functions of the exhaust flow rate. These functions are characterized by a pair of coefficients that can be estimated via a least-squares procedure. The proposed models can be adapted to encompass inherent nonlinearities that were implicit in previous instantaneous emissions modeling efforts. This article describes the methodology and presents an illustrative application which uses data collected from a diesel bus under real-world driving conditions.
Three-dimensional instantaneous dynamics modeling of present-day Aegean subduction
Glerum, Anne; Thieulot, Cedric; Pranger, Casper; van Hinsbergen, Douwe; Fraters, Menno; Spakman, Wim
2015-04-01
The Aegean region (Eastern Mediterranean) is exemplary of the interaction between crustal tectonics, plate motion, subduction and mantle flow: African subduction underneath the region has been continuous for at least the last 100 My, leading to about 2100-2500 km of subducted lithosphere residing in the mantle (van Hinsbergen et al., 2005). During this subduction, decoupled upper continental and oceanic crust accreted into a wedge of stacked nappes. In turn, these nappes have been significantly extended, predominantly during the last 25 My, due to the retreat of the African slab relative to Eurasia (van Hinsbergen and Schmid, 2012). As a first step to better understanding the coupling of the tectonic evolution of the crust and the underlying mantle dynamics, we are developing 3-D numerical models of the instantaneous dynamics of the present-day Aegean subduction system using the finite element code ASPECT (Kronbichler et al., 2012). The instantaneous models are set up with initial slab geometries derived from tomography and realistic plate boundary configurations and incorporate the major crustal weak zones of the overriding plate. Our modeling results in predictions of flow fields and stress, strain rate and rotation rate fields for the present-day tectonic setting of the Aegean region. By comparing our various model predictions to the widely available observations, such as focal mechanisms, GPS velocities and seismic anisotropy, we aim at an improved understanding of how mantle flow, subduction morphology and possibly slab segmentation, as well as the rheological behavior of the overriding plate, control present-day tectonic deformation. We expect to show preliminary results of this comparison. Kronbichler, M., Heister, T. and Bangerth, W. (2012), High Accuracy Mantle Convection Simulation through Modern Numerical Methods, Geophysical Journal International, 191, 12-29. Van Hinsbergen, D. J. J., Hafkenscheid, E., Spakman, W., Meulenkamp, J. E. and Wortel, R. (2005
Instantaneous Metabolic Cost of Walking: Joint-Space Dynamic Model with Subject-Specific Heat Rate.
Directory of Open Access Journals (Sweden)
Dustyn Roberts
Full Text Available A subject-specific model of instantaneous cost of transport (ICOT is introduced from the joint-space formulation of metabolic energy expenditure using the laws of thermodynamics and the principles of multibody system dynamics. Work and heat are formulated in generalized coordinates as functions of joint kinematic and dynamic variables. Generalized heat rates mapped from muscle energetics are estimated from experimental walking metabolic data for the whole body, including upper-body and bilateral data synchronization. Identified subject-specific energetic parameters-mass, height, (estimated maximum oxygen uptake, and (estimated maximum joint torques-are incorporated into the heat rate, as opposed to the traditional in vitro and subject-invariant muscle parameters. The total model metabolic energy expenditure values are within 5.7 ± 4.6% error of the measured values with strong (R2 > 0.90 inter- and intra-subject correlations. The model reliably predicts the characteristic convexity and magnitudes (0.326-0.348 of the experimental total COT (0.311-0.358 across different subjects and speeds. The ICOT as a function of time provides insights into gait energetic causes and effects (e.g., normalized comparison and sensitivity with respect to walking speed and phase-specific COT, which are unavailable from conventional metabolic measurements or muscle models. Using the joint-space variables from commonly measured or simulated data, the models enable real-time and phase-specific evaluations of transient or non-periodic general tasks that use a range of (aerobic energy pathway similar to that of steady-state walking.
International Nuclear Information System (INIS)
Capilla, J. E.; Rodrigo, J.; Gomez Hernandez, J. J.
2003-01-01
Characterizing the uncertainty of flow and mass transport models requires the definition of stochastic models to describe hydrodynamic parameters. Porosity and hydraulic conductivity (K) are two of these parameters that exhibit a high degree of spatial variability. K is usually the parameter whose variability influence to a more extended degree solutes movement. In fracture media, it is critical to properly characterize K in the most altered zones where flow and solutes migration tends to be concentrated. However, K measurements use to be scarce and sparse. This fact calls to consider stochastic models that allow quantifying the uncertainty of flow and mass transport predictions. This paper presents a convective transport problem solved in a 3D block of fractured crystalline rock. the case study is defined based on data from a real geological formation. As the scarcity of K data in fractures does not allow supporting classical multi Gaussian assumptions for K in fractures, the non multi Gaussian hypothesis has been explored, comparing mass transport results for alternative Gaussian and non-Gaussian assumptions. The latter hypothesis allows reproducing high spatial connectivity for extreme values of K. This feature is present in nature, might lead to reproduce faster solute pathways, and therefore should be modeled in order to obtain reasonably safe prediction of contaminants migration in a geological formation. The results obtained for the two alternative hypotheses show a remarkable impact of the K random function model in solutes movement. (Author) 9 refs
Sensitivity of Attitude Determination on the Model Assumed for ISAR Radar Mappings
Lemmens, S.; Krag, H.
2013-09-01
Inverse synthetic aperture radars (ISAR) are valuable instrumentations for assessing the state of a large object in low Earth orbit. The images generated by these radars can reach a sufficient quality to be used during launch support or contingency operations, e.g. for confirming the deployment of structures, determining the structural integrity, or analysing the dynamic behaviour of an object. However, the direct interpretation of ISAR images can be a demanding task due to the nature of the range-Doppler space in which these images are produced. Recently, a tool has been developed by the European Space Agency's Space Debris Office to generate radar mappings of a target in orbit. Such mappings are a 3D-model based simulation of how an ideal ISAR image would be generated by a ground based radar under given processing conditions. These radar mappings can be used to support a data interpretation process. E.g. by processing predefined attitude scenarios during an observation sequence and comparing them with actual observations, one can detect non-nominal behaviour. Vice versa, one can also estimate the attitude states of the target by fitting the radar mappings to the observations. It has been demonstrated for the latter use case that a coarse approximation of the target through an 3D-model is already sufficient to derive the attitude information from the generated mappings. The level of detail required for the 3D-model is determined by the process of generating ISAR images, which is based on the theory of scattering bodies. Therefore, a complex surface can return an intrinsically noisy ISAR image. E.g. when many instruments on a satellite are visible to the observer, the ISAR image can suffer from multipath reflections. In this paper, we will further analyse the sensitivity of the attitude fitting algorithms to variations in the dimensions and the level of detail of the underlying 3D model. Moreover, we investigate the ability to estimate the orientations of different
Directory of Open Access Journals (Sweden)
2016-01-01
Full Text Available The search of optimal variants for composite repair patches allows to increase the service life of a damaged air- plane structure. To sensibly choose the way of repair, it is necessary to have a computational complex to predict the stress- strain condition of "structure-adhesive-patch" system and to take into account the damage growth considering the material properties change. The variant of the computational complex based on inclusion method is proposed.For calculation purposes the repair bonded joint is divided into two areas: a metal plate with patch-shaped hole and a "patch-adhesive layer-skin" composite plate (inclusion.Calculation stages:Evaluation of the patch influence to the skin stress-strain condition, stress distribution between skin and patch in the case of no damage. Calculation of the stress-strain condition is performed separately for the skin with hole and for the inclusion; solutions are coupled based on strain compatibility.Definition of the damage growth parameters at new stress-strain condition due to bonded patch existence. Skincrack stress intensity factors are found to identify the crack growth velocity. Patch is modelled as a set of "springs" bridging the crack.Degradation analysis of elasticity properties for the patch material.Repair effectiveness is evaluated with respect to crack growth velocity reduction in the initial material in compari- son with the case of the patch absence.Calculation example for the crack repair effectiveness depending on number of loading cycles for the 7075-T6 aluminum skin is given. Repair patches are carbon-epoxy, glass-epoxy and boron-epoxy material systems with quasi- isotropic layup and GLARE hybrid metal-polymeric material.The analysis shows the high effectiveness of the carbon-epoxy patch. Due to low stiffness, the glass-epoxy patchdemonstrates the least effectiveness. GLARE patch containing the fiberglass plies oriented across the crack has the same effectiveness as the carbon and
Bamia, Christina; White, Ian R; Kenward, Michael G
2013-07-10
Linear mixed models are often used for the analysis of data from clinical trials with repeated quantitative outcomes. This paper considers linear mixed models where a particular form is assumed for the treatment effect, in particular constant over time or proportional to time. For simplicity, we assume no baseline covariates and complete post-baseline measures, and we model arbitrary mean responses for the control group at each time. For the variance-covariance matrix, we consider an unstructured model, a random intercepts model and a random intercepts and slopes model. We show that the treatment effect estimator can be expressed as a weighted average of the observed time-specific treatment effects, with weights depending on the covariance structure and the magnitude of the estimated variance components. For an assumed constant treatment effect, under the random intercepts model, all weights are equal, but in the random intercepts and slopes and the unstructured models, we show that some weights can be negative: thus, the estimated treatment effect can be negative, even if all time-specific treatment effects are positive. Our results suggest that particular models for the treatment effect combined with particular covariance structures may result in estimated treatment effects of unexpected magnitude and/or direction. Methods are illustrated using a Parkinson's disease trial. Copyright © 2012 John Wiley & Sons, Ltd.
Tang, Ronglin; Li, Zhao-Liang
2017-10-01
Surface evapotranspiration (ET) is one of the key components in global hydrological cycle and energy budget on Earth. This paper designs a theoretical relationship between daily and instantaneous ETs with a multiplication of multiple fractions through a mathematical derivation of the physics-based Penman-Monteith equation and further develops five methods for converting remotely sensed instantaneous ET to daily values, one of which is equivalent to the conventional constant evaporative fraction (EF) method. The five methods are then evaluated and intercompared using long-term ground-based eddy covariance system-measured half-hourly latent heat flux (LE) and three groups of Moderate Resolution Imaging Spectroradiometer-based instantaneous LE data sets collected from April 2009 to late October 2011 at the Yucheng station. Overall, the constant decoupling factor (Ω) method, the constant surface resistance (Rc) method, and the constant ratio of surface resistance to aerodynamic resistance (Rc/Ra) method could produce daily LE estimates that are in reasonably good agreement with the ground-based eddy covariance measurements, whereas the constant EF method and the constant Priestley-Taylor parameter (α) method underestimate the daily LE with larger biases and root-mean-square errors. The former three methods are of more solid physical foundation and can effectively capture the effect of temporally variable meteorological factors on the diurnal pattern of surface ET. They provide good alternatives to the nowadays commonly applied methods for the conversion of remotely sensed instantaneous ET to daily values.
3D instantaneous dynamics modeling of present-day Aegean subduction
Glerum, Anne; Spakman, Wim; van Hinsbergen, Douwe; Pranger, Casper
2017-04-01
To study the sensitivity of surface observables to subduction and mantle flow, i.e. the coupling of crustal tectonics and the underlying mantle dynamics, we have developed 3D numerical models of the instantaneous crust-mantle dynamics of the eastern Mediterranean. These models comprise both a realistic crust-lithosphere system and the underlying mantle. The focus for this presentation lies on the regional crustal flow response to the present-day Aegean subduction system. Our curved model domain measures 40°x40°x2900km with the Aegean subduction system taken as the geographic center. Model set-ups are based on geological and geophysical data of the eastern Mediterranean. We first create a 3D synthetic geometry of the crust-lithosphere system in a stand-alone program, including the present-day configuration of the plates in the region and crust and lithosphere thickness variations abstracted from Moho and LAB maps (Faccenna et al., 2014, Carafa et al., 2015). In addition we construct the geometry of the Aegean slab from a seismic tomography model (UU-P07; Amaru, 2007) and earthquake hypocenters (NCEDC, 2014). Geometries are then imported into the finite element code ASPECT (Kronbichler et al., 2012) using specially designed plugins. The mantle initial temperature conditions can include deviations from an adiabatic profile obtained from conversion of the UU-P07 seismic velocity anomalies to temperature anomalies using a depth-dependent scaling (Karato, 2008). We model compressible mantle flow for which material properties are obtained from thermodynamics P-T lookup-tables (Perple_X, Connolly, 2009) in combination with nonlinear viscoplastic rheology laws. Sublithospheric flow through the lateral model boundaries is left free via open boundary conditions (Chertova et al., 2012), while plate motion is prescribed at the model sides in terms of relative as well as absolute plate motion velocities (e.g. Doubrovine et al., 2012). So far, we used a free-slip surface, but
Mechanical deformation model of the western United States instantaneous strain-rate field
Pollitz, F.F.; Vergnolle, M.
2006-01-01
We present a relationship between the long-term fault slip rates and instantaneous velocities as measured by Global Positioning System (GPS) or other geodetic measurements over a short time span. The main elements are the secularly increasing forces imposed by the bounding Pacific and Juan de Fuca (JdF) plates on the North American plate, viscoelastic relaxation following selected large earthquakes occurring on faults that are locked during their respective interseismic periods, and steady slip along creeping portions of faults in the context of a thin-plate system. In detail, the physical model allows separate treatments of faults with known geometry and slip history, faults with incomplete characterization (i.e. fault geometry but not necessarily slip history is available), creeping faults, and dislocation sources distributed between the faults. We model the western United States strain-rate field, derived from 746 GPS velocity vectors, in order to test the importance of the relaxation from historic events and characterize the tectonic forces imposed by the bounding Pacific and JdF plates. Relaxation following major earthquakes (M ??? 8.0) strongly shapes the present strain-rate field over most of the plate boundary zone. Equally important are lateral shear transmitted across the Pacific-North America plate boundary along ???1000 km of the continental shelf, downdip forces distributed along the Cascadia subduction interface, and distributed slip in the lower lithosphere. Post-earthquake relaxation and tectonic forcing, combined with distributed deep slip, constructively interfere near the western margin of the plate boundary zone, producing locally large strain accumulation along the San Andreas fault (SAF) system. However, they destructively interfere further into the plate interior, resulting in smaller and more variable strain accumulation patterns in the eastern part of the plate boundary zone. Much of the right-lateral strain accumulation along the SAF
Huang, J; Vieland, V J
2001-01-01
It is well known that the asymptotic null distribution of the homogeneity lod score (LOD) does not depend on the genetic model specified in the analysis. When appropriately rescaled, the LOD is asymptotically distributed as 0.5 chi(2)(0) + 0.5 chi(2)(1), regardless of the assumed trait model. However, because locus heterogeneity is a common phenomenon, the heterogeneity lod score (HLOD), rather than the LOD itself, is often used in gene mapping studies. We show here that, in contrast with the LOD, the asymptotic null distribution of the HLOD does depend upon the genetic model assumed in the analysis. In affected sib pair (ASP) data, this distribution can be worked out explicitly as (0.5 - c)chi(2)(0) + 0.5chi(2)(1) + cchi(2)(2), where c depends on the assumed trait model. E.g., for a simple dominant model (HLOD/D), c is a function of the disease allele frequency p: for p = 0.01, c = 0.0006; while for p = 0.1, c = 0.059. For a simple recessive model (HLOD/R), c = 0.098 independently of p. This latter (recessive) distribution turns out to be the same as the asymptotic distribution of the MLS statistic under the possible triangle constraint, which is asymptotically equivalent to the HLOD/R. The null distribution of the HLOD/D is close to that of the LOD, because the weight c on the chi(2)(2) component is small. These results mean that the cutoff value for a test of size alpha will tend to be smaller for the HLOD/D than the HLOD/R. For example, the alpha = 0.0001 cutoff (on the lod scale) for the HLOD/D with p = 0.05 is 3.01, while for the LOD it is 3.00, and for the HLOD/R it is 3.27. For general pedigrees, explicit analytical expression of the null HLOD distribution does not appear possible, but it will still depend on the assumed genetic model. Copyright 2001 S. Karger AG, Basel
Reinoso, J.; Paggi, M.; Linder, C.
2017-06-01
Fracture of technological thin-walled components can notably limit the performance of their corresponding engineering systems. With the aim of achieving reliable fracture predictions of thin structures, this work presents a new phase field model of brittle fracture for large deformation analysis of shells relying on a mixed enhanced assumed strain (EAS) formulation. The kinematic description of the shell body is constructed according to the solid shell concept. This enables the use of fully three-dimensional constitutive models for the material. The proposed phase field formulation integrates the use of the (EAS) method to alleviate locking pathologies, especially Poisson thickness and volumetric locking. This technique is further combined with the assumed natural strain method to efficiently derive a locking-free solid shell element. On the computational side, a fully coupled monolithic framework is consistently formulated. Specific details regarding the corresponding finite element formulation and the main aspects associated with its implementation in the general purpose packages FEAP and ABAQUS are addressed. Finally, the applicability of the current strategy is demonstrated through several numerical examples involving different loading conditions, and including linear and nonlinear hyperelastic constitutive models.
Directory of Open Access Journals (Sweden)
Vinod Kumar Mishra
2013-06-01
Full Text Available Purpose: The purpose of this paper to develop an inventory model for instantaneous deteriorating items with the consideration of the facts that the deterioration rate can be controlled by using the preservation technology (PT and the holding cost & demand rate both are linear function of time which was treated as constant in most of the deteriorating inventory model. Design/methodology/approach: Developed the mathematical equation of deterministic deteriorating inventory model in which demand rate and holding cost both is linear function of time, deterioration rate is constant, backlogging rate is variable and depend on the length of the next replenishment, shortages are allowed and partially backlogged and obtain an analytical solution which optimizes the total cost of the proposed inventory model. Findings: The model can be applied for optimizing the total inventory cost of deteriorating items inventory for such business enterprises where they use the preservation technology to control the deterioration rate under other assumptions of the model. Originality/value: The inventory system for deteriorating items has been an object of study for a long time, but little is known about the effect of investing in reducing the rate of product deterioration and their significant impact in the business. The proposed model is effective as well as efficient for the business organization that uses the preservation technology to reduce the deterioration rate of the instantaneous deteriorating items of the inventory.
Wildhaber, Mark L.; Lamberson, Peter J.
2004-01-01
Various mechanisms of habitat choice in fishes based on food and/or temperature have been proposed: optimal foraging for food alone; behavioral thermoregulation for temperature alone; and behavioral energetics and discounted matching for food and temperature combined. Along with development of habitat choice mechanisms, there has been a major push to develop and apply to fish populations individual-based models that incorporate various forms of these mechanisms. However, it is not known how the wide variation in observed and hypothesized mechanisms of fish habitat choice could alter fish population predictions (e.g. growth, size distributions, etc.). We used spatially explicit, individual-based modeling to compare predicted fish populations using different submodels of patch choice behavior under various food and temperature distributions. We compared predicted growth, temperature experience, food consumption, and final spatial distribution using the different models. Our results demonstrated that the habitat choice mechanism assumed in fish population modeling simulations was critical to predictions of fish distribution and growth rates. Hence, resource managers who use modeling results to predict fish population trends should be very aware of and understand the underlying patch choice mechanisms used in their models to assure that those mechanisms correctly represent the fish populations being modeled.
Chang, Daniel Y.; Rowe, Neil C.
2013-05-01
While conducting a cutting-edge research in a specific domain, we realize that (1) requirements clarity and correctness are crucial to our success [1], (2) hardware is hard to change, most work is in software requirements development, coding and testing [2], (3) requirements are constantly changing, so that configurability, reusability, scalability, adaptability, modularity and testability are important non-functional attributes [3], (4) cross-domain knowledge is necessary for complex systems [4], and (5) if our research is successful, the results could be applied to other domains with similar problems. In this paper, we propose to use model-driven requirements engineering (MDRE) to model and guide our requirements/development, since models are easy to understand, execute, and modify. The domain for our research is Electronic Warfare (EW) real-time ultra-wide instantaneous bandwidth (IBW1) signal simulation. The proposed four MDRE models are (1) Switch-and-Filter architecture, (2) multiple parallel data bit streams alignment, (3) post-ADC and pre-DAC bits re-mapping, and (4) Discrete Fourier Transform (DFT) filter bank. This research is unique since the instantaneous bandwidth we are dealing with is in gigahertz range instead of conventional megahertz.
Energy Technology Data Exchange (ETDEWEB)
Wall, Casey J. [Department of Atmospheric Sciences, University of Washington, Seattle, Washington; Hartmann, Dennis L. [Department of Atmospheric Sciences, University of Washington, Seattle, Washington; Ma, Po-Lun [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington
2017-12-01
Instantaneous, coincident, footprint-level satellite observations of cloud properties and radiation taken during austral summer over the Southern Ocean are used to study relationships between clouds and large-scale meteorology. Cloud properties are very sensitive to the strength of vertical motion in the middle-troposphere, and low-cloud properties are sensitive to estimated inversion strength, low-level temperature advection, and sea surface temperature. These relationships are quantified. An index for the meteorological anomalies associated with midlatitude cyclones is presented, and it is used to reveal the sensitivity of clouds to the meteorology within the warm- and cold-sector of cyclones. The observed relationships between clouds and meteorology are compared to those in the Community Atmosphere Model version 5 (CAM5) using satellite simulators. Low-clouds simulated by CAM5 are too few, too bright, and contain too much ice, and low-clouds located in the cold-sector of cyclones are too sensitive to variations in the meteorology. The latter two biases are dramatically reduced when CAM5 is coupled with an updated boundary layer parameterization know as Cloud Layers Unified by Binormals (CLUBB). More generally, this study demonstrates that examining the instantaneous timescale is a powerful approach to understanding the physical processes that control clouds and how they are represented in climate models. Such an evaluation goes beyond the cloud climatology and exposes model bias under various meteorological conditions.
Nakahara, Shinji; Kawamura, Takashi; Ichikawa, Masao; Wakai, Susumu
2006-01-01
Previous research has indicated that unbelted drivers are at higher risk of involvement in fatal crashes than belted drivers, suggesting selective recruitment that high-risk drivers are unlikely to become belt users. However, how the risk of involvement in fatal crashes among unbelted drivers varies according to the level of seat belt use among general drivers has yet to be clearly quantified. We, therefore, developed mathematical models describing the risk of fatal crashes in relation to seat belt use among the general public, and explored how these models fitted to changes in driver mortality and changes in observed seat belt use using Japanese data. Mortality data between 1979 and 1994 were obtained from vital statistics, and mortality data in the daytime and nighttime between 1980 and 2001 and belt use data between 1979 and 2001 were obtained from the National Police Agency. Regardless of the data set analyzed, exponential models, assuming that high-risk drivers would gradually become belt users in order of increasing risk as seat belt use among general motorists reached high levels, showed the best fit. Our models provide an insight into behavioral changes among high-risk drivers and support the selective recruitment hypothesis.
Wandera, Loise; Mallick, Kaniska; Kiely, Gerard; Roupsard, Olivier; Peichl, Mathias; Magliulo, Vincenzo
2017-04-01
Upscaling instantaneous evapotranspiration retrieved at any specific time-of-day (ETi) to daily evapotranspiration (ETd) is a key challenge in mapping regional ET using polar orbiting sensors. Various studies have unanimously cited the shortwave incoming radiation (RS) to be the most robust reference variable explaining the ratio between ETd and ETi . This study aims to contribute in ETi upscaling for global studies using the ratio between daily and instantaneous incoming shortwave radiation (RSd / RSi) as a factor for converting ETi to ETd. This paper proposes an artificial neural network (ANN) machine-learning algorithm first to predict RSd from RSi followed by using the RSd / RSi ratio to convert ETi to ETd across different terrestrial ecosystems. Using RSi and RSd observations from multiple sub-networks of the FLUXNET database spread across different climates and biomes (to represent inputs that would typically be obtainable from remote sensors during the overpass time) in conjunction with some astronomical variables (e.g. solar zenith angle, day length, exoatmospheric shortwave radiation), we developed the ANN model for reproducing RSd and further used it to upscale ETi to ETd. The efficiency of the ANN is evaluated for different morning and afternoon times of day, under varying sky conditions, and also at different geographic locations. RS-based upscaled ETd produced a significant linear relation (R 2 = 0.65 to 0.69), low bias (-0.31 to -0.56 MJ m-2 d -1 ; approx. 4 %), and good agreement (RMSE 1.55 to 1.86 MJ m-2 d -1 ; approx. 10 %) with the observed ETd, although a systematic overestimation of ETd was also noted under persistent cloudy sky conditions. Inclusion of soil moisture and rainfall information in ANN training reduced the systematic overestimation tendency in predominantly overcast days. An intercomparison with existing upscaling method at daily, 8-day, monthly, and yearly temporal resolution revealed a robust performance of the ANNdriven RS
Non-instantaneous impulses in differential equations
Agarwal, Ravi; O'Regan, Donal
2017-01-01
This monograph is the first published book devoted to the theory of differential equations with non-instantaneous impulses. It aims to equip the reader with mathematical models and theory behind real life processes in physics, biology, population dynamics, ecology and pharmacokinetics. The authors examine a wide scope of differential equations with non-instantaneous impulses through three comprehensive chapters, providing an all-rounded and unique presentation on the topic, including: - Ordinary differential equations with non-instantaneous impulses (scalar and n-dimensional case) - Fractional differential equa tions with non-instantaneous impulses (with Caputo fractional derivatives of order q ϵ (0, 1)) - Ordinary differential equations with non-instantaneous impulses occurring at random moments (with exponential, Erlang, or Gamma distribution) Each chapter focuses on theory, proofs and examples, and contains numerous graphs to enrich the reader’s understanding. Additionally, a carefully selected bibliogr...
Directory of Open Access Journals (Sweden)
J. Y. Ding
2011-01-01
Full Text Available The linear unit hydrograph used in hydrologic design analysis and flood forecasting is known as the transfer function and the kernel function in time series analysis and systems theory, respectively. This paper reviews the use of an input-dependent or variable kernel in a linear convolution integral as a quasi-nonlinear approach to unify nonlinear overland flow, channel routing and catchment runoff processes. The conceptual model of a variable instantaneous unit hydrograph (IUH is characterized by a nonlinear storage-discharge relation, q = c^{N}s^{N}, where the storage exponent N is an index or degree of watershed nonlinearity, and the scale parameter c is a discharge coefficient. When the causative rainfall excess intensity of a unit hydrograph is known, parameters N and c can be determined directly from its shape factor, which is the product of the unit peak ordinate and the time to peak, an application of the statistical method of moments in its simplest form. The 2-parameter variable IUH model is calibrated by the shape factor method and verified by convolution integral using both the direct and inverse Bakhmeteff varied-flow functions on two watersheds of vastly different sizes, each having a family of four or five unit hydrographs as reported by the well-known Minshall (1960 paper and the seldom-quoted Childs (1958 one, both located in the US. For an 11-hectare catchment near Edwardsville in southern Illinois, calibration for four moderate storms shows an average N value of 1.79, which is 7% higher than the theoretical value of 1.67 by Manning friction law, while the heaviest storm, which is three to six times larger than the next two events in terms of the peak discharge and runoff volume, follows the Chezy law of 1.5. At the other end of scale, for the Naugatuck River at Thomaston in Connecticut having a drainage area of 186.2 km^{2}, the average calibrated
DEFF Research Database (Denmark)
Brand, Marek; Thorsen, Jan Eric; Svendsen, Svend
2012-01-01
as much as possible. This requires a review and improvement of a DH network, in-house substations, and the whole domestic hot water (DHW) supply system, with the focus on user comfort, hygiene, overall cost and energy efficiency. This paper describes some practical approaches to the implementation of low......-temperature district heating (LTDH) with an entry-to-substation temperature around 50 °C. To this end we developed a numerical model for an instantaneous LTDH substation that takes into consideration the effect of service pipes. The model has been verified and can be used for the further optimization of the whole...
ISAR imaging using the instantaneous range instantaneous Doppler method
CSIR Research Space (South Africa)
Wazna, TM
2015-10-01
Full Text Available In Inverse Synthetic Aperture Radar (ISAR) imaging, the Range Instantaneous Doppler (RID) method is used to compensate for the nonuniform rotational motion of the target that degrades the Doppler resolution of the ISAR image. The Instantaneous Range...
Compilation of Instantaneous Source Functions for Varying ...
African Journals Online (AJOL)
In this series, thirty-two(32) different models were identified for the normal and vertically inverted letter 'P' two-layered reservoir with a horizontal well in each layer. Relevant instantaneous source functions were also derived and tabulated for all the identified models.
A Spatial Model for the Instantaneous Estimation of Wind Power at a Large Number of Unobserved Sites
DEFF Research Database (Denmark)
Lenzi, Amanda; Guillot, Gilles; Pinson, Pierre
2015-01-01
We propose a hierarchical Bayesian spatial model to obtain predictive densities of wind power at a set of un-monitored locations. The model consists of a mixture of Gamma density for the non-zero values and degenerated distributions at zero. The spatial dependence is described through a common Ga...
Directory of Open Access Journals (Sweden)
Marcos Carrasco-Benavides
2014-11-01
Full Text Available A study was carried out to parameterize the METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration model for estimating instantaneous values of albedo (shortwave albedo (αi, net radiation (Rni and soil heat flux (Gi, sensible (Hi and latent heat (LEi over a drip-irrigated Merlot vineyard (location: 35°25′ LS; 71°32′ LW; 125 m.a.s. (l. The experiment was carried out in a plot of 4.25 ha, processing 15 Landsat images, which were acquired from 2006 to 2009. An automatic weather station was placed inside the experimental plot to measure αi, Rni and Gi. In the same tower an Eddy Covariance (EC system was mounted to measure Hi and LEi. Specific sub-models to estimate Gi, leaf area index (LAI and aerodynamic roughness length for momentum transfer (zom were calibrated for the Merlot vineyard as an improvement to the original METRIC model. Results indicated that LAI, zom and Gi were estimated using the calibrated functions with errors of 4%, 2% and 17%, while those were computed using the original functions with errors of 58%, 81%, and 5%, respectively. At the time of satellite overpass, comparisons between measured and estimated values indicated that METRIC overestimated αi in 21% and Rni in 11%. Also, METRIC using the calibrated functions overestimated Hi and LEi with errors of 16% and 17%, respectively while it using the original functions overestimated Hi and LEi with errors of 13% and 15%, respectively. Finally, LEi was estimated with root mean square error (RMSE between 43 and 60 W∙m−2 and mean absolute error (MAE between 35 and 48 W∙m−2 for both calibrated and original functions, respectively. These results suggested that biases observed for instantaneous pixel-by-pixel values of Rni, Gi and other intermediate components of the algorithm were presumably absorbed into the computation of sensible heat flux as a result of the internal self-calibration of METRIC.
Wang, Fumin; Gonsamo, Alemu; Chen, Jing M; Black, T Andrew; Zhou, Bin
2014-11-01
Daily canopy photosynthesis is usually temporally upscaled from instantaneous (i.e., seconds) photosynthesis rate. The nonlinear response of photosynthesis to meteorological variables makes the temporal scaling a significant challenge. In this study, two temporal upscaling schemes of daily photosynthesis, the integrated daily model (IDM) and the segmented daily model (SDM), are presented by considering the diurnal variations of meteorological variables based on a coupled photosynthesis-stomatal conductance model. The two models, as well as a simple average daily model (SADM) with daily average meteorological inputs, were validated using the tower-derived gross primary production (GPP) to assess their abilities in simulating daily photosynthesis. The results showed IDM closely followed the seasonal trend of the tower-derived GPP with an average RMSE of 1.63 g C m(-2) day(-1), and an average Nash-Sutcliffe model efficiency coefficient (E) of 0.87. SDM performed similarly to IDM in GPP simulation but decreased the computation time by >66%. SADM overestimated daily GPP by about 15% during the growing season compared to IDM. Both IDM and SDM greatly decreased the overestimation by SADM, and improved the simulation of daily GPP by reducing the RMSE by 34 and 30%, respectively. The results indicated that IDM and SDM are useful temporal upscaling approaches, and both are superior to SADM in daily GPP simulation because they take into account the diurnally varying responses of photosynthesis to meteorological variables. SDM is computationally more efficient, and therefore more suitable for long-term and large-scale GPP simulations.
Mechanism of instantaneous coal outbursts
Energy Technology Data Exchange (ETDEWEB)
Guan, P.; Wang, H.Y.; Zhang, Y.X. [Peking University, Beijing (China). School of Earth & Space Science
2009-10-15
Thousands of mine workers die every year from mining accidents, and instantaneous coal outbursts in underground coal mines are one of the major killers. Various models for these outbursts have been proposed, but the precise mechanism is still unknown. We hypothesize that the mechanism of coal outbursts is similar to magma fragmentation during explosive volcanic eruptions; i.e., it is caused by high gas pressure inside coal but low ambient pressure on it, breaking coal into pieces and releasing the high-pressure gas in a shock wave. Hence, coal outbursts may be regarded as another type of gas-driven eruption, in addition to explosive volcanic, lake, and possible ocean eruptions. We verify the hypothesis by experiments using a shock-tube apparatus. Knowing the mechanism of coal outbursts is the first step in developing prediction and mitigation measures. The new concept of gas-driven solid eruption is also important to a better understanding of salt-gas outbursts, rock-gas outbursts, and mud volcano eruptions.
The instantaneous frequency rate spectrogram
Czarnecki, Krzysztof
2016-01-01
An accelerogram of the instantaneous phase of signal components referred to as an instantaneous frequency rate spectrogram (IFRS) is presented as a joint time-frequency distribution. The distribution is directly obtained by processing the short-time Fourier transform (STFT) locally. A novel approach to amplitude demodulation based upon the reassignment method is introduced as a useful by-product. Additionally, an estimator of energy density versus the instantaneous frequency rate (IFR) is proposed and referred to as the IFR profile. The energy density is estimated based upon both the classical energy spectrogram and the IFRS smoothened by the median filter. Moreover, the impact of an analyzing window width, additive white Gaussian noise and observation time is tested. Finally, the introduced method is used for the analysis of the acoustic emission of an automotive engine. The recording of the engine of a Lamborghini Gallardo is analyzed as an example.
'instantaneous velocimetry' using an interferometer
Indian Academy of Sciences (India)
2017-02-08
Feb 8, 2017 ... The experiment involves setting up a one-dimensional non-stationary heat flow inside the solid via step-temperature excitation to launch a spectrum of dissimilar 'moving isothermal surfaces' at the origin. Moving isothermal surfaces exhibit macroscale. 'rectilinear translatory motion'; the instantaneous ...
Kuai, L.; Bowman, K. W.; Worden, H. M.; Paulot, F.; Paynter, D.; Oman, L.; Strode, S. A.; Rozanov, E.; Stenke, A.; Revell, L. E.; Plummer, D. A.
2017-12-01
The estimated ozone radiative forcing (RF) from chemical-climate models range widely from +0.2 to +0.6 Wm-2. The reason has never been well understood. Since the ozone absorption in the 9.6 μm band contributes 97% of the O3 longwave RF, the variation of outgoing longwave radiation (OLR) due to ozone is dominant by this band. The observed TOA flux over 9.6 µm ozone band by Thermal Emission Spectrometer (TES) shows the global distribution has unique spatial patterns. In addition, the simulated TOA fluxes over 9.6 µm ozone band by different models have never been evaluated against observations. The bias of TOA flux from model could be primarily contributed by the bias of temperature, water vapor and ozone. Furthermore, the sensitivity of TOA flux to tropospheric ozone (instantaneous radiative kernel, IRK) may also affected by these biases (Kuai et al., 2017). The bias in TOA flux would eventually propagate into model calculations of ozone RF and cause divergence of the predictions of future climate by models. In this study, we applied the observation-based IRK product by AURA TES to attribute the CCMI model bias in TOA flux over 9.6 µm ozone band to ozone, water vapor, air temperature, and surface temperature. The comparisons of the three CCMI models (AM3, SOCOL3 and GEOCCM) to TES observations suggest that 1) all models underestimate the TOA flux at tropics and subtropics. 2) The TOA flux bias is comparable similar by AM3 and GEOSCC (-0.2 to -0.3 W/m2) however is larger for the relative young model, SOCOL3 (-0.4 to -0.6 W/m2). 3) The contributions by surface temperature are similarly moderate (-0.2 W/m2). 4) The contribution of ozone is largest by SOCOL3 (-0.3 W/m2), smallest by GEOSCCM (less than 0.1 W/m2) and moderate by AM3 (-0.2 W/m2). 5) Overall, the contributions by atmospheric temperature are all small (less than 0.1 W/m2). 6) The contribution of water vapor is negative and small by both SOCOL3 and GEOSCCM (0.1 W/m2) however large and positive by AM3 (0
Existence of mild solutions to partial differential equations with non-instantaneous impulses
Directory of Open Access Journals (Sweden)
Pengyu Chen
2016-09-01
Full Text Available In this article, we study the existence of piecewise-continuous mild solutions for the initial value problems for a class of semilinear evolution equations. These equations have non-instantaneous impulses in Banach spaces and the corresponding solution semigroup is noncompact. We assume that the nonlinear term satisfies certain local growth condition and a noncompactness measure condition. Also we assume the non-instantaneous impulsive functions satisfy some Lipschitz conditions. An example is given to illustrate our results.
Directory of Open Access Journals (Sweden)
T. IKONEN
2008-12-01
Full Text Available The effects of kappa-beta-casein genotypes and b-lactoglobulin genotypes on the renneting properties and composition of milk were estimated for 174 and 155 milk samples of 59 Finnish Ayrshire and 55 Finnish Friesian cows, respectively. As well as the random additive genetic and permanent environmental effects of a cow, the model included the fixed effects for parity, lactation stage, season, kappa-beta-casein genotypes and b-lactoglobulin genotypes. Favourable renneting properties were associated with kappa-beta-casein genotypes ABA 1 A 2 , ABA 1 A 1 and AAA 1 A 2 in the Finnish Ayrshire, and with ABA 2 B, AAA 1 A 3 , AAA 2 A 3 , ABA 1 A 2 and ABA 2 A 2 in the Finnish Friesian. The favourable effect of these genotypes on curd firming time and on firmness of the curd was partly due to their association with a high kappa-casein concentration in the milk. The effect of the kappa-casein E allele on renneting properties was unfavourable compared with that of the kappa-casein B allele, and possibly with that of the A allele. The beta-lactoglobulin genotypes had no effect on renneting properties but they had a clear effect on the protein composition of milk. The beta-lactoglobulin AA genotype was associated with a high whey protein % and beta-lactoglobulin concentration and the BB genotype with a high casein % and casein number.;
Energy Technology Data Exchange (ETDEWEB)
Berretta, Ana Lucia Olmedo
1999-07-01
The hydraulic conductivity is one of the most important parameters to understand the movement of water in the unsaturated zone. Reliable estimations are difficult to obtain, once the hydraulic conductivity is highly variable. This study was carried out at 'Escola Superior de Agricultura Luiz de Queiroz', Universidade de Sao Paulo, in a Kandiudalfic Eutrudox soil. The hydraulic conductivity was determined by a direct and an indirect method. The instantaneous profile method was described and the hydraulic conductivity as a function of soil water content was determined by solving the Richards equation. Tensiometers were used to estimate the total soil water potential, and the neutron probe and the soil retention curve were used to estimate soil water content in the direct method. The neutron probe showed to be not adequately sensible to the changes of soil water content in this soil. Despite of the soil retention curve provides best correlation values to soil water content as a function of water redistribution time, the soil water content in this soil did not vary too much till the depth of 50 cm, reflecting the influence of the presence of a Bt horizon. The soil retention curve was well fitted by the van Genuchten model used as an indirect method. The values of the van Genuchten and the experimental relative hydraulic conductivity obtained by the instantaneous profile method provided a good correlation. However, the values estimated by the model were always lower than that ones obtained experimentally. (author)
Communicating Instantaneous Air Quality Data: Pilot Project
Communicating Instantaneous Air Quality Data: Pilot ProjectEPA is launching a pilot project to test a new tool for making instantaneous outdoor air quality data useful for the public. The new “sensor scale” is designed to be used with sensors
Maximization of instantaneous wind penetration using particle ...
African Journals Online (AJOL)
In this paper, a new methodology has been proposed for attaining the maximum instantaneous wind penetration by the optimization of grid control parameters. Particle Swarm Optimization (PSO) based algorithm has been developed to obtain the maximum instantaneous penetration. The developed algorithm has been ...
Oscillator strength of instantaneous diatomic sodium molecules
Energy Technology Data Exchange (ETDEWEB)
Perny, G.
1991-10-01
We introduce definitely the notion of instantaneous molecules, real or fictitious, in spite of its utilization in certain fields of the supraconductivity, genetics and advanced medical research. Calculation of the oscillator strength of instantaneous sodium diatomic molecules gives (f{sub mol})sup(Na{sub 2(i)})=6,86. This method is transposable at lithium and other Ia elements. (orig.).
Oscillator strength of instantaneous diatomic sodium molecules
Perny, G.
1991-12-01
We introduce definitely the notion of instantaneous molecules, real or fictitious, in spite of its utilization in certain fields of the supraconductivity, genetics and advanced medical research. Calculation of the oscillator strength of instantaneous sodium diatomic molecules gives [ f mol]Na 2( i)=6,86. This method is transposable at lithium and other Ia elements.
Regularization of Instantaneous Frequency Attribute Computations
Yedlin, M. J.; Margrave, G. F.; Van Vorst, D. G.; Ben Horin, Y.
2014-12-01
We compare two different methods of computation of a temporally local frequency:1) A stabilized instantaneous frequency using the theory of the analytic signal.2) A temporally variant centroid (or dominant) frequency estimated from a time-frequency decomposition.The first method derives from Taner et al (1979) as modified by Fomel (2007) and utilizes the derivative of the instantaneous phase of the analytic signal. The second method computes the power centroid (Cohen, 1995) of the time-frequency spectrum, obtained using either the Gabor or Stockwell Transform. Common to both methods is the necessity of division by a diagonal matrix, which requires appropriate regularization.We modify Fomel's (2007) method by explicitly penalizing the roughness of the estimate. Following Farquharson and Oldenburg (2004), we employ both the L curve and GCV methods to obtain the smoothest model that fits the data in the L2 norm.Using synthetic data, quarry blast, earthquakes and the DPRK tests, our results suggest that the optimal method depends on the data. One of the main applications for this work is the discrimination between blast events and earthquakesFomel, Sergey. " Local seismic attributes." , Geophysics, 72.3 (2007): A29-A33.Cohen, Leon. " Time frequency analysis theory and applications." USA: Prentice Hall, (1995).Farquharson, Colin G., and Douglas W. Oldenburg. "A comparison of automatic techniques for estimating the regularization parameter in non-linear inverse problems." Geophysical Journal International 156.3 (2004): 411-425.Taner, M. Turhan, Fulton Koehler, and R. E. Sheriff. " Complex seismic trace analysis." Geophysics, 44.6 (1979): 1041-1063.
Automatic traveltime picking using instantaneous traveltime
Saragiotis, Christos
2013-02-08
Event picking is used in many steps of seismic processing. We present an automatic event picking method that is based on a new attribute of seismic signals, instantaneous traveltime. The calculation of the instantaneous traveltime consists of two separate but interrelated stages. First, a trace is mapped onto the time-frequency domain. Then the time-frequency representation is mapped back onto the time domain by an appropriate operation. The computed instantaneous traveltime equals the recording time at those instances at which there is a seismic event, a feature that is used to pick the events. We analyzed the concept of the instantaneous traveltime and demonstrated the application of our automatic picking method on dynamite and Vibroseis field data.
Compilation of Instantaneous Source Functions for Varying ...
African Journals Online (AJOL)
Compilation of Instantaneous Source Functions for Varying Architecture of a Layered Reservoir with Mixed Boundaries and Horizontal Well Completion Part IV: Normal and Inverted Letter 'h' and 'H' Architecture.
Compilation of Instantaneous Source Functions for Varying ...
African Journals Online (AJOL)
Compilation of Instantaneous Source Functions for Varying Architecture of a Layered Reservoir with Mixed Boundaries and Horizontal Well Completion Part III: B-Shaped Architecture with Vertical Well in the Upper Layer.
Zare, Yasser; Rhim, Sungsoo; Garmabi, Hamid; Rhee, Kyong Yop
2018-04-01
The networks of nanoparticles in nanocomposites cause solid-like behavior demonstrating a constant storage modulus at low frequencies. This study examines the storage modulus of poly (lactic acid)/poly (ethylene oxide)/carbon nanotubes (CNT) nanocomposites. The experimental data of the storage modulus in the plateau regions are obtained by a frequency sweep test. In addition, a simple model is developed to predict the constant storage modulus assuming the properties of the interphase regions and the CNT networks. The model calculations are compared with the experimental results, and the parametric analyses are applied to validate the predictability of the developed model. The calculations properly agree with the experimental data at all polymer and CNT concentrations. Moreover, all parameters acceptably modulate the constant storage modulus. The percentage of the networked CNT, the modulus of networks, and the thickness and modulus of the interphase regions directly govern the storage modulus of nanocomposites. The outputs reveal the important roles of the interphase properties in the storage modulus. Copyright © 2018 Elsevier Ltd. All rights reserved.
Directory of Open Access Journals (Sweden)
A. K. Bhunia
2011-04-01
Full Text Available In this paper, a single item deterministic inventory model with two separate warehouses called owned warehouse/show-room (OW and rented warehouse (RW is developed. The proposed model of this paper also considers a realistic assumption regarding the storage capacity of the rented warehouse. Demand is a function of selling price, advertisement of an item and displayed inventory level in OW. The stocks of RW are shipped to OW under bulk release pattern where shortages are not allowed. We discuss different scenarios of the proposed model to address relative size of stock dependency parameters and the capacity of owned warehouse. For each scenario, the corresponding problem is formulated as a constrained mixed integer nonlinear programming problem with three integer and two non-integer variables and a real coded genetic algorithm (RCGA is developed to solve the resulted problem. The proposed model of the paper is also examined using some numerical examples and sensitivity analysis is performed.
International Nuclear Information System (INIS)
Wang, Z.; Cao, X.W.
2007-01-01
The Chinese Experimental Fast Reactor (CEFR) is under installation and commissioning right now. It is essential to investigate core disruptive accidents (CDAs) for the evaluation of CEFR's safety characteristic. As part-I preliminary investigation, accident of total instantaneous blockage (TIB) in single subassembly scale is modeled and analyzed. The degradation scenario has been calculated by a fluid-dynamics analysis code for liquid-metal fast reactors (LMFRs). For further investigation of accident process and influence to the neighboring bundles, seven subassembly domain is then simulated and calculated as part-II investigation. Total instantaneous blockage is assumed to occur in the center subassembly under normal operating conditions and consequences to neighboring assemblies are studied. The result shows that the key events, such as sodium boiling, clad melting, fuel particles relocation, hexcan melt-through and melt propagation into neighboring six assemblies symmetrically are adequately simulated. From comparison and discussion of the CEFR's results with the SCARABEE tests and Superphenix (SPX1)-type reactor simulation, it is concluded that all the key events appear in the same sequence whereas the propagation is limited in neighboring six assemblies. The discrepancy is probably due to less fuel inventory and better cooling capacity in CEFR subassembly design. TIB calculations help to give a better understanding and prediction of hypothetical accident scenario in subassembly blockage accidents for CEFR
DEFF Research Database (Denmark)
Ghoreishi, Maryam; Mirzazadeh, Abolfazl; Nakhai Kamalabadi, Isa
2014-01-01
. The effects of time value of money are studied using the Discounted Cash Flow approach. The main objective is to determine the optimal selling price, the optimal length of the production period, and the optimal length of inventory cycle simultaneously such that the present value of total profit is maximized....... An efficient algorithm is presented to find the optimal solution of the developed model. Finally, a numerical example is extracted to solve the presented inventory model using our proposed algorithm, and the effects of the customer returns, inflation, and delay in payments are also discussed....
DEFF Research Database (Denmark)
Morillas, Laura; Villagarcia, Luis; Domingo, Francisco
2014-01-01
The temperature-based two-source model (TSM) of Norman et al. (1995) has not been properly evaluated under the water stress conditions that are typical in natural Mediterranean drylands. In such areas, the asynchrony between precipitation and energy supply strongly reduces evapotranspiration, E (or...... factors showing the strongest effect on the TSM accuracy. In contrast with results observed in other ecosystems, in this Mediterranean tussock grassland the TSM accuracy was not clearly reduced by cloudiness and it was improved under highly stressed vegetation conditions. The parallel resistances scheme...
International Nuclear Information System (INIS)
Walrand, Stephan; Hanin, François-Xavier; Pauwels, Stanislas; Jamar, François
2012-01-01
Clinical trials on 177 Lu– 90 Y therapy used empirical activity ratios. Radionuclides (RN) with larger beta maximal range could favourably replace 90 Y. Our aim is to provide RN dose-deposition kernels and to compare the tumour control probability (TCP) of RN combinations. Dose kernels were derived by integration of the mono-energetic beta-ray dose distributions (computed using Monte Carlo) weighted by their respective beta spectrum. Nine homogeneous spherical tumours (1–25 mm in diameter) and four spherical tumours including a lattice of cold, but alive, spheres (1, 3, 5, 7 mm in diameter) were modelled. The TCP for 93 Y, 90 Y and 125 Sn in combination with 177 Lu in variable proportions (that kept constant the renal cortex biological effective dose) were derived by 3D dose kernel convolution. For a mean tumour-absorbed dose of 180 Gy, 2 mm homogeneous tumours and tumours including 3 mm diameter cold alive spheres were both well controlled (TCP > 0.9) using a 75–25% combination of 177 Lu and 90 Y activity. However, 125 Sn– 177 Lu achieved a significantly better result by controlling 1 mm-homogeneous tumour simultaneously with tumours including 5 mm diameter cold alive spheres. Clinical trials using RN combinations should use RN proportions tuned to the patient dosimetry. 125 Sn production and its coupling to somatostatin analogue appear feasible. Assuming similar pharmacokinetics 125 Sn is the best RN for combination with 177 Lu in peptide receptor radiotherapy justifying pharmacokinetics studies in rodent of 125 Sn-labelled somatostatin analogues. (paper)
Instantaneous flow rate of vitreous cutter probes.
Rossi, Tommaso; Querzoli, Giorgio; Angelini, Giampiero; Rossi, Alessandro; Malvasi, Carlo; Iossa, Mario; Ripandelli, Guido
2014-11-20
We report on instantaneous volumetric flow rate of vitreous cutters measured by means of particle image velocimetry (PIV). In an in vitro experimental study, vitreous cutters mounting a regular blade (RB) or modified Twedge blade (TB) engineered for higher flow were connected to a console machine equipped with a double peristaltic and Venturi pump, and immersed in balanced salt solution (BSS). Instantaneous flow was measured on aspiration tubing sections proximal to the cutter hand piece. Measures settings were as follows: (1) regular functioning at 3000 and 6000 cuts per minute (cpm) with 300 mm Hg aspiration with both pumps, (2) aspiration tubing clamped proximal to pump cassette, and (3) aspiration tubing clamped proximal to hand piece, and (4) flow fluctuation as a function of cut rate also was calculated. For main outcome measures, instantaneous volumetric flow rate in mL/min and flow fluctuation measured as the standard deviation of flow rate were measured. Regular functioning shows sinusoidal flow oscillating at cut rate frequency, with amplitude between ±50 mL/min at 3000 cpm and ±35 mL/min at 6000 cpm. The TB always determined a bimodal wave and neither blade nor pump type influenced the sinusoidal pattern of flow. Clamping aspiration tubing zeroes flow, but does not influence fluctuation frequency or amplitude. Clamping at the hand piece determined a significantly higher oscillation. Oscillation amplitude retain a typical resonance pattern with significant changes in function of cut rate and resonance occurs at approximately 4000 cpm. Cutter blade action determines instantaneous flow rate fluctuation that interferes significantly with cutter suction and hampers a steady suction through cutter port. In a surgical scenario, this translates into a higher risk of inadvertent retinal entrapment and lower predictability of cutter behavior, especially at frequency approaching resonance. Copyright 2014 The Association for Research in Vision and Ophthalmology
Observation of Brownian motion in liquids at short times: instantaneous velocity and memory loss.
Kheifets, Simon; Simha, Akarsh; Melin, Kevin; Li, Tongcang; Raizen, Mark G
2014-03-28
Measurement of the instantaneous velocity of Brownian motion of suspended particles in liquid probes the microscopic foundations of statistical mechanics in soft condensed matter. However, instantaneous velocity has eluded experimental observation for more than a century since Einstein's prediction of the small length and time scales involved. We report shot-noise-limited, high-bandwidth measurements of Brownian motion of micrometer-sized beads suspended in water and acetone by an optical tweezer. We observe the hydrodynamic instantaneous velocity of Brownian motion in a liquid, which follows a modified energy equipartition theorem that accounts for the kinetic energy of the fluid displaced by the moving bead. We also observe an anticorrelated thermal force, which is conventionally assumed to be uncorrelated.
Quantifying instantaneous performance in alpine ski racing.
Federolf, Peter Andreas
2012-01-01
Alpine ski racing is a popular sport in many countries and a lot of research has gone into optimising athlete performance. Two factors influence athlete performance in a ski race: speed and the chosen path between the gates. However, to date there is no objective, quantitative method to determine instantaneous skiing performance that takes both of these factors into account. The purpose of this short communication was to define a variable quantifying instantaneous skiing performance and to study how this variable depended on the skiers' speed and on their chosen path. Instantaneous skiing performance was defined as time loss per elevation difference dt/dz, which depends on the skier's speed v(z), and the distance travelled per elevation difference ds/dz. Using kinematic data collected in an earlier study, it was evaluated how these variables can be used to assess the individual performance of six ski racers in two slalom turns. The performance analysis conducted in this study might be a useful tool not only for athletes and coaches preparing for competition, but also for sports scientists investigating skiing techniques or engineers developing and testing skiing equipment.
Instantaneous aerosol dynamics in a turbulent flow
Zhou, Kun
2012-01-01
Dibutyl phthalate aerosol particles evolution dynamics in a turbulent mixing layer is simulated by means of direct numerical simulation for the flow field and the direct quadrature method of moments for the aerosol evolution. Most par-ticles are nucleated in a thin layer region corresponding to a specific narrow temperature range near the cool stream side. However, particles undergo high growth rate on the hot stream side due to condensation. Coagulation decreases the total particle number density at a rate which is highly correlated to the in-stantaneous number density.
Assessment of movement distribution in the lumbar spine using the instantaneous axis of rotation
Energy Technology Data Exchange (ETDEWEB)
Park, Ki Won [Trine University, Angola (Indonesia)
2014-12-15
The position of the torso and the magnitude of exertion are thought to influence the distribution pattern of intervertebral movements within the lumbar spine. Abnormal intervertebral movements have been correlated with the risk of spine injuries. Since the capability to measure movement distribution within the lumbar spine noninvasively is limited, a convenient method to diagnose joint motion function was proposed. The goal of this research was to test the efficacy of the instantaneous axis of rotation for assessment of the distribution of movement within the lumbar spine. The proposed method was evaluated in the bio mechanical model. The results showed that the location of instantaneous axis of rotation lowered with increased trunk exertion force, and slightly moved higher with increased trunk angle. Recognizing that abnormal location of the instantaneous axis of rotation correlated with spinal pain, these results suggest potential the location of the instantaneous axis of rotation relates to the risk of low back pain on distributed spinal kinematics.
Instantaneous flywheel torque of IC engine grey-box identification
Milašinović, A.; Knežević, D.; Milovanović, Z.; Škundrić, J.
2018-01-01
In this paper a mathematical model developed for the identification of excitation torque acting on the IC engine flywheel is presented. The excitation torque gained through internal combustion of the fuel in the IC engine is transmitted from the flywheel to the transmission. The torque is not constant but variable and is a function of the crank angle. The verification of the mathematical model was done on a 4-cylinder 4-stroke diesel engine for which the in-cylinder pressure was measured in one cylinder and the instantaneous angular speed of the crankshaft at its free end. The research was conducted on a hydraulic engine brake. Inertial forces of all rotational parts, from flywheel to the turbine wheel of the engine brake, are acting on the flywheel due to the nonuniform motion of the flywheel. It is known from the theory of turbomachinery that the torque on the hydraulic brake is a quadratic function of angular speed. Due to that and the variable angular speed of the turbine wheel of the engine brake, the torque during one engine cycle is also variable. The motivation for this research was the idea (intention) to determine the instantaneous torque acting on the flywheel as a function of the crank angle with a mathematical model without any measuring and based on this to determine the quality of work of specific cylinders of the multi-cylinder engine. The crankshaft was considered elastic and also its torsional vibrations were taken into account.
Moore, Catrin E.; Pan-Ngum, Wirichada; Wijedoru, Lalith P. M.; Sona, Soeng; Nga, Tran Vu Thieu; Duy, Pham Thanh; Vinh, Phat Voong; Chheng, Kheng; Kumar, Varun; Emary, Kate; Carter, Michael; White, Lisa; Baker, Stephen; Day, Nicholas P. J.; Parry, Christopher M.
2014-01-01
Rapid diagnostic tests are needed for typhoid fever (TF) diagnosis in febrile children in endemic areas. Five hundred children admitted to the hospital in Cambodia between 2009 and 2010 with documented fever (≥ 38°C) were investigated using blood cultures (BCs), Salmonella Typhi/Paratyphi A real-time polymerase chain reactions (PCRs), and a Typhoid immunoglobulin M flow assay (IgMFA). Test performance was determined by conventional methods and Bayesian latent class modeling. There were 32 cases of TF (10 BC- and PCR-positive cases, 14 BC-positive and PCR-negative cases, and 8 BC-negative and PCR-positive cases). IgMFA sensitivity was 59.4% (95% confidence interval = 41–76), and specificity was 97.8% (95% confidence interval = 96–99). The model estimate sensitivity for BC was 81.0% (95% credible interval = 54–99). The model estimate sensitivity for PCR was 37.8% (95% credible interval = 26–55), with a specificity of 98.2% (95% credible interval = 97–99). The model estimate sensitivity for IgMFA (≥ 2+) was 77.9% (95% credible interval = 58–90), with a specificity of 97.5% (95% credible interval = 95–100). The model estimates of IgMFA sensitivity and specificity were comparable with BCs and better than estimates using conventional analysis. PMID:24218407
Entanglement consumption of instantaneous nonlocal quantum measurements
International Nuclear Information System (INIS)
Clark, S R; Jaksch, D; Connor, A J; Popescu, S
2010-01-01
Relativistic causality has dramatic consequences on the measurability of nonlocal variables and poses the fundamental question of whether it is physically meaningful to speak about the value of nonlocal variables at a particular time. Recent work has shown that by weakening the role of the measurement in preparing eigenstates of the variable, it is in fact possible to measure all nonlocal observables instantaneously by exploiting entanglement. However, for these measurement schemes to succeed with certainty, an infinite amount of entanglement must be distributed initially and all this entanglement is necessarily consumed. In this work, we sharpen the characterization of instantaneous nonlocal measurements by explicitly devising schemes in which only a finite amount of the initially distributed entanglement is ever utilized. This enables us to determine an upper bound to the average consumption for the most general cases of nonlocal measurements. This includes the tasks of state verification, where the measurement verifies if the system is in a given state, and verification measurements of a general set of eigenstates of an observable. Despite its finiteness, the growth of entanglement consumption is found to display an extremely unfavourable exponential of an exponential scaling with either the number of qubits needed to contain the Schmidt rank of the target state or the total number of qubits in the system for an operator measurement. This scaling is seen to be a consequence of the combination of the generic exponential scaling of unitary decompositions combined with the highly recursive structure of our scheme required to overcome the no-signalling constraint of relativistic causality.
Oleari, Claudio; Melgosa, Manuel; Huertas, Rafael
2011-11-01
The most widely used color-difference formulas are based on color-difference data obtained under D65 illumination or similar and for a 10° visual field; i.e., these formulas hold true for the CIE 1964 observer adapted to D65 illuminant. This work considers the psychometric color-vision model based on the Optical Society of America-Uniform Color Scales (OSA-UCS) system previously published by the first author [J. Opt. Soc. Am. A 21, 677 (2004); Color Res. Appl. 30, 31 (2005)] with the additional hypothesis that complete illuminant adaptation with perfect color constancy exists in the visual evaluation of color differences. In this way a computational procedure is defined for color conversion between different illuminant adaptations, which is an alternative to the current chromatic adaptation transforms. This color conversion allows the passage between different observers, e.g., CIE 1964 and CIE 1931. An application of this color conversion is here made in the color-difference evaluation for any observer and in any illuminant adaptation: these transformations convert tristimulus values related to any observer and illuminant adaptation to those related to the observer and illuminant adaptation of the definition of the color-difference formulas, i.e., to the CIE 1964 observer adapted to the D65 illuminant, and then the known color-difference formulas can be applied. The adaptations to the illuminants A, C, F11, D50, Planckian and daylight at any color temperature and for CIE 1931 and CIE 1964 observers are considered as examples, and all the corresponding transformations are given for practical use.
Navier-Stokes-Voigt Equations with Memory in 3D Lacking Instantaneous Kinematic Viscosity
Di Plinio, Francesco; Giorgini, Andrea; Pata, Vittorino; Temam, Roger
2017-11-01
We consider a Navier-Stokes-Voigt fluid model where the instantaneous kinematic viscosity has been completely replaced by a memory term incorporating hereditary effects, in presence of Ekman damping. Unlike the classical Navier-Stokes-Voigt system, the energy balance involves the spatial gradient of the past history of the velocity rather than providing an instantaneous control on the high modes. In spite of this difficulty, we show that our system is dissipative in the dynamical systems sense and even possesses regular global and exponential attractors of finite fractal dimension. Such features of asymptotic well-posedness in absence of instantaneous high modes dissipation appear to be unique within the realm of dynamical systems arising from fluid models.
Navier-Stokes-Voigt Equations with Memory in 3D Lacking Instantaneous Kinematic Viscosity
Di Plinio, Francesco; Giorgini, Andrea; Pata, Vittorino; Temam, Roger
2018-04-01
We consider a Navier-Stokes-Voigt fluid model where the instantaneous kinematic viscosity has been completely replaced by a memory term incorporating hereditary effects, in presence of Ekman damping. Unlike the classical Navier-Stokes-Voigt system, the energy balance involves the spatial gradient of the past history of the velocity rather than providing an instantaneous control on the high modes. In spite of this difficulty, we show that our system is dissipative in the dynamical systems sense and even possesses regular global and exponential attractors of finite fractal dimension. Such features of asymptotic well-posedness in absence of instantaneous high modes dissipation appear to be unique within the realm of dynamical systems arising from fluid models.
Examining roles pharmacists assume in disasters: a content analytic approach.
Ford, Heath; Dallas, Cham E; Harris, Curt
2013-12-01
Numerous practice reports recommend roles pharmacists may adopt during disasters. This study examines the peer-reviewed literature for factors that explain the roles pharmacists assume in disasters and the differences in roles and disasters when stratified by time. Quantitative content analysis was used to gather data consisting of words and phrases from peer-reviewed pharmacy literature regarding pharmacists' roles in disasters. Negative binomial regression and Kruskal-Wallis nonparametric models were applied to the data. Pharmacists' roles in disasters have not changed significantly since the 1960s. Pharmaceutical supply remains their preferred role, while patient management and response integration roles decrease in context of common, geographically widespread disasters. Policy coordination roles, however, significantly increase in nuclear terrorism planning. Pharmacists' adoption of nonpharmaceutical supply roles may represent a problem of accepting a paradigm shift in nontraditional roles. Possible shortages of personnel in future disasters may change the pharmacists' approach to disaster management.
Three-dimensional instantaneous velocity field measurement using ...
Indian Academy of Sciences (India)
2014-02-13
Feb 13, 2014 ... In the present study, a digital holography microscope has been developed to study instantaneous 3D ... Rv. 1. Introduction. Digital holography is a nonintrusive optical technique having immense potential for 3D .... microscope (DHM) for 3D instantaneous velocity field measurements in microchannels.
Instantaneous signal attenuation method for analysis of PFG fractional diffusions
Lin, Guoxing
2016-08-01
An instantaneous signal attenuation (ISA) method for analyzing pulsed field gradient (PFG) fractional diffusion (FD) has been developed, which is modified from the propagator approach developed in 2001 by Lin et al. for analyzing PFG normal diffusion. Both, the current ISA method and the propagator method have the same fundamental basis that the total signal attenuation (SA) is the accumulation of all the ISA, and the ISA is the average SA of the whole diffusion system at each moment. However, the manner of calculating ISA is different. Unlike the use of the instantaneous propagator in the propagator method, the current method directly calculates ISA as A(K(t‧), t‧ + dt‧)/A(K(t‧), t‧), where A(K(t‧), t‧ + dt‧) and A(K(t‧), t‧) are the SA. This modification makes the current method applicable to PFG FD as the instantaneous propagator may not be obtainable in FD. The ISA method was applied to study PFG SA including the effect of finite gradient pulse widths (FGPW) for free FD, restricted FD and the FD affected by a non-homogeneous gradient field. The SA expressions were successfully obtained for all three types of free FDs while other current methods still have difficulty in obtaining all of them. The results from this method agree with reported results such as that obtained by the effective phase shift diffusion equation (EPSDE) method. The M-Wright phase distribution approximation was also used to derive an SA expression for time FD as a comparison, which agrees with ISA method. Additionally, the continuous-time random walk (CTRW) simulation was performed to simulate the SA of PFG FD, and the simulation results agree with the analytical results. Particularly, the CTRW simulation results give good support to the analytical results including FGPW effect for free FD and restricted time FD based on a fractional derivative model where there have been no corresponding theoretical reports to date. The theoretical SA expressions including FGPW obtained
Faes, Luca; Erla, Silvia; Porta, Alberto; Nollo, Giandomenico
2013-08-28
We present an approach for the quantification of directional relations in multiple time series exhibiting significant zero-lag interactions. To overcome the limitations of the traditional multivariate autoregressive (MVAR) modelling of multiple series, we introduce an extended MVAR (eMVAR) framework allowing either exclusive consideration of time-lagged effects according to the classic notion of Granger causality, or consideration of combined instantaneous and lagged effects according to an extended causality definition. The spectral representation of the eMVAR model is exploited to derive novel frequency domain causality measures that generalize to the case of instantaneous effects the known directed coherence (DC) and partial DC measures. The new measures are illustrated in theoretical examples showing that they reduce to the known measures in the absence of instantaneous causality, and describe peculiar aspects of directional interaction among multiple series when instantaneous causality is non-negligible. Then, the issue of estimating eMVAR models from time-series data is faced, proposing two approaches for model identification and discussing problems related to the underlying model assumptions. Finally, applications of the framework on cardiovascular variability series and multichannel EEG recordings are presented, showing how it allows one to highlight patterns of frequency domain causality consistent with well-interpretable physiological interaction mechanisms.
Teaching of Intonation Patterns to the Deaf Using the Instantaneous Pitch-Period Indicator.
Dolansky, Ladislav; And Others
The research was concerned with the experimental use of Model II of the Instantaneous Pitch-Period Indicator (IPPI) with deaf subjects, and with the design and construction of a portable unit. Deaf adults and deaf children participated in training programs designed to develop more effective patterns of speech using the IPPI for visual monitoring…
Directory of Open Access Journals (Sweden)
Christine Ward-Paige
Full Text Available BACKGROUND: Increasingly, underwater visual censuses (UVC are used to assess fish populations. Several studies have demonstrated the effectiveness of protected areas for increasing fish abundance or provided insight into the natural abundance and structure of reef fish communities in remote areas. Recently, high apex predator densities (>100,000 individuals x km(-2 and biomasses (>4 tonnes x ha(-1 have been reported for some remote islands suggesting the occurrence of inverted trophic biomass pyramids. However, few studies have critically evaluated the methods used for sampling conspicuous and highly mobile fish such as sharks. Ideally, UVC are done instantaneously, however, researchers often count animals that enter the survey area after the survey has started, thus performing non-instantaneous UVC. METHODOLOGY/PRINCIPAL FINDINGS: We developed a simulation model to evaluate counts obtained by divers deploying non-instantaneous belt-transect and stationary-point-count techniques. We assessed how fish speed and survey procedure (visibility, diver speed, survey time and dimensions affect observed fish counts. Results indicate that the bias caused by fish speed alone is huge, while survey procedures had varying effects. Because the fastest fishes tend to be the largest, the bias would have significant implications on their biomass contribution. Therefore, caution is needed when describing abundance, biomass, and community structure based on non-instantaneous UVC, especially for highly mobile species such as sharks. CONCLUSIONS/SIGNIFICANCE: Based on our results, we urge that published literature state explicitly whether instantaneous counts were made and that survey procedures be accounted for when non-instantaneous counts are used. Using published density and biomass values of communities that include sharks we explore the effect of this bias and suggest that further investigation may be needed to determine pristine shark abundances and the
Instantaneous interactions of hadrons on the light cone
International Nuclear Information System (INIS)
Hyer, T.
1994-01-01
Hadron wave functions are most naturally defined in the framework of light-cone quantization, a Hamiltonian formulation quantized at equal light-cone ''time'' τ≡t+z. One feature of the light-cone perturbation theory is the presence of instantaneous interactions, which complicate the consideration of processes involving bound states. We show that these interactions can be written in a simple and general form, parametrized by an instantaneous contribution ψ to the hadronic wave function. We use the rotational invariance of Feynman diagrams to relate this instantaneous piece of the meson wave function to the propagating part, and to obtain constraints relating wave functions and quark fragmentation amplitudes
How Afghanistan Can Assume Ownership for the Ongoing Conflict
National Research Council Canada - National Science Library
Horn, Sr, John M
2008-01-01
In view of United States global commitments and larger Global War on Terror (GWOT) strategy, the ultimate security goal in Afghanistan must be for the Afghans to assume ownership of the counterinsurgency struggle...
Waiblinger, Christian; Brugger, Dominik; Schwarz, Cornelius
2015-04-01
Which physical parameter of vibrissa deflections is extracted by the rodent tactile system for discrimination? Particularly, it remains unclear whether perception has access to instantaneous kinematic parameters (i.e., the details of the trajectory) or relies on temporally integration of the movement trajectory such as frequency (e.g., spectral information) and intensity (e.g., mean speed). Here, we use a novel detection of change paradigm in head-fixed rats, which presents pulsatile vibrissa stimuli in seamless sequence for discrimination. This procedure ensures that processes of decision making can directly tap into sensory signals (no memory functions involved). We find that discrimination performance based on instantaneous kinematic cues far exceeds the ones provided by frequency and intensity. Neuronal modeling based on barrel cortex single units shows that small populations of sensitive neurons provide a transient signal that optimally fits the characteristic of the subject's perception. The present study is the first to show that perceptual read-out is superior in situations allowing the subject to base perception on detailed trajectory cues, that is, instantaneous kinematic variables. A possible impact of this finding on tactile systems of other species is suggested by evidence for instantaneous coding also in primates. © The Author 2013. Published by Oxford University Press.
Malott, Spencer; O'Carroll, Denis M.; Robinson, Clare E.
2017-09-01
Wave-induced water exchange and groundwater flows in beach aquifers impact the fate of contaminants including nutrients, fecal bacteria, and nonaqueous phase liquids (NAPLs). Waves induce high-frequency fluxes in shallow beach sediments. In addition, the phase-averaged effect of waves (wave setup) drives deeper flow recirculations through a beach aquifer. Field data of shallow instantaneous and time-averaged vertical head gradients (fluxes) are first compared with deeper time-averaged fluxes over a period of varying wave conditions. The time-averaged fluxes are equivalent to that which would be simulated assuming a phase-averaged water surface (i.e., wave setup). Based on this comparison, the need to simulate phase-resolved wave motion versus the simplified phase-averaged water surface in predicting contaminant fate is evaluated. While high-frequency fluxes cause large surface water volumes to filter through beach sediments, the exchanging water has a short residence time (colloidal contaminants (e.g., particulate organic matter and fecal bacteria) as sediment interactions affect their transport and residence time. Finally, multiphase simulations illustrate the differential effect of considering instantaneous versus time-averaged fluxes on the downward migration of NAPL in beach sediments. This study provides an important foundation for future field and modeling efforts focused on understanding and predicting contaminant transport in wave-influenced beaches.
Constraining the instantaneous aerosol influence on cloud albedo
Energy Technology Data Exchange (ETDEWEB)
Gryspeerdt, Edward; Quaas, Johannes; Ferrachat, Sylvaine; Gettelman, Andrew; Ghan, Steven; Lohmann, Ulrike; Morrison, Hugh; Neubauer, David; Partridge, Daniel G.; Stier, Philip; Takemura, Toshihiko; Wang, Hailong; Wang, Minghuai; Zhang, Kai
2017-04-26
Much of the uncertainty in estimates of the anthropogenic forcing of climate change comes from uncertainties in the instantaneous effect of aerosols on cloud albedo, known as the Twomey effect or the radiative forcing from aerosol–cloud interactions (RFaci), a component of the total or effective radiative forcing. Because aerosols serving as cloud condensation nuclei can have a strong influence on the cloud droplet number concentration (Nd), previous studies have used the sensitivity of the Nd to aerosol properties as a constraint on the strength of the RFaci. However, recent studies have suggested that relationships between aerosol and cloud properties in the present-day climate may not be suitable for determining the sensitivity of the Nd to anthropogenic aerosol perturbations. Using an ensemble of global aerosol–climate models, this study demonstrates how joint histograms between Nd and aerosol properties can account for many of the issues raised by previous studies. It shows that if the anthropogenic contribution to the aerosol is known, the RFaci can be diagnosed to within 20% of its actual value. The accuracy of different aerosol proxies for diagnosing the RFaci is investigated, confirming that using the aerosol optical depth significantly underestimates the strength of the aerosol–cloud interactions in satellite data.
Constraining the instantaneous aerosol influence on cloud albedo
Quaas, Johannes; Ferrachat, Sylvaine; Gettelman, Andrew; Ghan, Steven; Lohmann, Ulrike; Morrison, Hugh; Neubauer, David; Partridge, Daniel G.; Takemura, Toshihiko; Wang, Hailong; Wang, Minghuai; Zhang, Kai
2017-01-01
Much of the uncertainty in estimates of the anthropogenic forcing of climate change comes from uncertainties in the instantaneous effect of aerosols on cloud albedo, known as the Twomey effect or the radiative forcing from aerosol–cloud interactions (RFaci), a component of the total or effective radiative forcing. Because aerosols serving as cloud condensation nuclei can have a strong influence on the cloud droplet number concentration (Nd), previous studies have used the sensitivity of the Nd to aerosol properties as a constraint on the strength of the RFaci. However, recent studies have suggested that relationships between aerosol and cloud properties in the present-day climate may not be suitable for determining the sensitivity of the Nd to anthropogenic aerosol perturbations. Using an ensemble of global aerosol–climate models, this study demonstrates how joint histograms between Nd and aerosol properties can account for many of the issues raised by previous studies. It shows that if the anthropogenic contribution to the aerosol is known, the RFaci can be diagnosed to within 20% of its actual value. The accuracy of different aerosol proxies for diagnosing the RFaci is investigated, confirming that using the aerosol optical depth significantly underestimates the strength of the aerosol–cloud interactions in satellite data. PMID:28446614
Modeling Fish Growth in Low Dissolved Oxygen
Neilan, Rachael Miller
2013-01-01
This article describes a computational project designed for undergraduate students as an introduction to mathematical modeling. Students use an ordinary differential equation to describe fish weight and assume the instantaneous growth rate depends on the concentration of dissolved oxygen. Published laboratory experiments suggest that continuous…
Application of instantaneous spectral analysis and acoustic ...
Indian Academy of Sciences (India)
44
Advanced seismic attributes technology is useful in the qualitative and quantitative. 125 reservoir characterization. .... is preferred in the present study, where the amplitude attenuation, synthetic wedge modeling, and. 219 ...... Petrophysical Analysis: A Case Study From The Southern Indus Basin, Pakistan; J. 574. Earth Sci.
Benchmark calculations of present-day instantaneous radiative forcing in clear, aerosol-free skies
Pincus, Robert; Evans, K. Franklin; Manners, James; Paynter, David; Mlawer, Eli
2017-04-01
At the root of the effective radiative forcing driving climate change is the change in radiative flux at the top of the atmosphere due to changes in atmospheric composition - the so-called "instantaneous radiative forcing" (IRF). Estimates of global mean present-day instantaneous radiative forcing under cloud- and aerosol-free conditions show surprising diversity given the level of understanding of spectroscopy and radiative transfer. Much of this diversity, especially in estimates from climate models, is artificial, reflecting only differing errors and approximations in radiative transfer parameterizations. Calculations with more accurate line-by-line models have been considered far too expensive to be practical on a global scale. We report here on benchmark calculations of present-day instantaneous radiative forcing by greenhouse gases in the absence of clouds and aerosols made with very high spectral-resolution models. The problem is made computationally practical by defining a set of roughly 100 atmospheric profiles and associated weights obtained from present-day atmospheric conditions as represented by reanalysis via simulated annealing to reproduce global- and regional-mean fluxes with sampling errors of less than 1% (verified by cross-validation with independent radiative transfer models). Cloud- and aerosol-free IRF is then computed from these profiles using present-day and pre-industrial greenhouse gas concentrations. We report on results from two line-by-line and one high-resolution k-distribution model.
Djebbi, Ramzi
2015-08-19
The instantaneous traveltime is able to reduce the non-linearity of full waveform inversion (FWI) that originates from the wrapping of the phase. However, the adjoint state method in this case requires a total of 5 modeling calculations to compute the gradient. Also, considering the larger modeling cost for anisotropic wavefield extrapolation and the necessity to use a line-search algorithm to estimate a step length that depends on the parameters scale, we propose to calculate the gradient based on the instantaneous traveltime sensitivity kernels. We, specifically, use the sensitivity kernels computed using dynamic ray-tracing to build the gradient. The resulting update is computed using a matrix decomposition and accordingly the computational cost is reduced. We consider a simple example where an anomaly is embedded into a constant background medium and we compute the update for the VTI wave equation parameterized using vh, η and ε.
Instantaneous Non-Local Computation of Low T-Depth Quantum Circuits
DEFF Research Database (Denmark)
Speelman, Florian
2016-01-01
applications in the context of foundations of quantum physics and in distributed computing. The best known general construction for instantaneous non-local quantum computation requires a pre-shared state which is exponentially large in the number of qubits involved in the operation, while efficient......-depth of a quantum circuit, able to perform non-local computation of quantum circuits with a (poly-)logarithmic number of layers of T gates with quasi-polynomial entanglement. Our proofs combine ideas from blind and delegated quantum computation with the garden-hose model, a combinatorial model of communication......Instantaneous non-local quantum computation requires multiple parties to jointly perform a quantum operation, using pre-shared entanglement and a single round of simultaneous communication. We study this task for its close connection to position-based quantum cryptography, but it also has natural...
Instantaneous frequency tracking method for composite cable-stayed bridge
Zhong, Rumian; Zong, Zhouhong; Pai, P. Frank; Ruan, Xuewei; Niu, Jie
2018-02-01
This paper presents an instantaneous frequency (IF) tracking method based on conjugate-pair decomposition, and describes a signal filtering methodology that is employed to eliminate unwanted frequencies. The proposed methodology is verified and compared with Hilbert-Huang transform method by numerical simulation, steel beams and composite cable-stayed bridge experiment. The results show the proposed method has good robustness, adaptability and anti-noise capability which can be used to accurately extract the instantaneous frequency in complex environments; in addition, the extracted frequencies are close to each other using conjugate-pair decomposition and Hilbert-Huang transform. Moreover, the proposed method may be further applied in structural damage identification.
On Instantaneous Power Dissipation in Class B Amplifier
Directory of Open Access Journals (Sweden)
Hristo Zhivomirov
2014-08-01
Full Text Available The present paper describes the analysis of the instantaneous power dissipation by the two active components in a class B power amplifier. Attention is paid to restrictions of the instantaneous power dissipation relations in reference literature, and the consequences of their misuse. A new generalized equation that takes into account the power dissipated by the two active devices is proposed. The theoretical statement is substantiated by Matlab® numeric computation and visualization, Cadence OrCAD® simulations and measurements of a real-world audio power amplifier performed by NI USB-6211 measurement complex.
Three-dimensional instantaneous velocity field measurement using ...
Indian Academy of Sciences (India)
2014-02-13
Feb 13, 2014 ... set equal to 20 μl/min. The instantaneous 3D velocity field is obtained by correlating the particles obtained from the 3D numerical reconstruction of holograms using particle tracking velocimetry. (PTV). Keywords. Holography; velocity measurements; laminar flow in microchannel. PACS Nos 42.40.–i; 06.30.
Three-dimensional instantaneous velocity field measurement using ...
Indian Academy of Sciences (India)
2014-02-13
Feb 13, 2014 ... ... Singh P K Panigrahi. Contributed Papers Volume 82 Issue 2 February 2014 pp 439-444 ... Abstract. In the present study, a digital holography microscope has been developed to study instantaneous 3D velocity field in a square channel of 1000 × 1000 2 cross-section. The flow field is seeded with ...
Instantaneous Rayleigh scattering from excitons localized in monolayer islands
DEFF Research Database (Denmark)
Langbein, Wolfgang; Leosson, Kristjan; Jensen, Jacob Riis
2000-01-01
We show that the initial dynamics of Rayleigh scattering from excitons in quantum wells can be either instantaneous or delayed, depending on the exciton ensemble studied. For excitation of the entire exciton resonance, a finite rise time given by the inverse inhomogeneous broadening: of the exciton...
Voltage sag source location based on instantaneous energy detection
DEFF Research Database (Denmark)
Chen, Zhe; Xinzhou, Dong; Wei, Kong
2007-01-01
Voltage sag is the major power quality problem, which could disrupt the operation of sensitive equipment. This paper presents the applications of instantaneous energy direction for voltage sag source detection. Simulations have been performed to provide the analysis for system with distributed...... generation units. The studies show that the presented method can effectively detect the location of the voltage sag source....
Instantaneous planar pressure determination from PIV in turbulent flow
De Kat, R.; Van Oudheusden, B.W.
2011-01-01
This paper deals with the determination of instantaneous planar pressure fields from velocity data obtained by particle image velocimetry (PIV) in turbulent flow. The operating principles of pressure determination using a Eulerian or a Lagrangian approach are described together with theoretical
Directory of Open Access Journals (Sweden)
Dayong Ning
2016-03-01
Full Text Available The acoustic signals of internal combustion engines contain valuable information about the condition of engines. These signals can be used to detect incipient faults in engines. However, these signals are complex and composed of a faulty component and other noise signals of background. As such, engine conditions’ characteristics are difficult to extract through wavelet transformation and acoustic emission techniques. In this study, an instantaneous frequency analysis method was proposed. A new time–frequency model was constructed using a fixed amplitude and a variable cycle sine function to fit adjacent points gradually from a time domain signal. The instantaneous frequency corresponds to single value at any time. This study also introduced instantaneous frequency calculation on the basis of an inverse trigonometric fitting method at any time. The mean value of all local maximum values was then considered to identify the engine condition automatically. Results revealed that the mean of local maximum values under faulty conditions differs from the normal mean. An experiment case was also conducted to illustrate the availability of the proposed method. Using the proposed time–frequency model, we can identify engine condition and determine abnormal sound produced by faulty engines.
Inhomogeneous point-process entropy: An instantaneous measure of complexity in discrete systems
Valenza, Gaetano; Citi, Luca; Scilingo, Enzo Pasquale; Barbieri, Riccardo
2014-05-01
Measures of entropy have been widely used to characterize complexity, particularly in physiological dynamical systems modeled in discrete time. Current approaches associate these measures to finite single values within an observation window, thus not being able to characterize the system evolution at each moment in time. Here, we propose a new definition of approximate and sample entropy based on the inhomogeneous point-process theory. The discrete time series is modeled through probability density functions, which characterize and predict the time until the next event occurs as a function of the past history. Laguerre expansions of the Wiener-Volterra autoregressive terms account for the long-term nonlinear information. As the proposed measures of entropy are instantaneously defined through probability functions, the novel indices are able to provide instantaneous tracking of the system complexity. The new measures are tested on synthetic data, as well as on real data gathered from heartbeat dynamics of healthy subjects and patients with cardiac heart failure and gait recordings from short walks of young and elderly subjects. Results show that instantaneous complexity is able to effectively track the system dynamics and is not affected by statistical noise properties.
MERRA 3D Analyzed State, Meteorology Instantaneous 6-hourly (eta-coord, 2/3x1/2L72) V5.2.0
National Aeronautics and Space Administration — The MAI6NVANA or inst6_3d_ana_Nv data product is the MERRA Data Assimilation System 3-Dimensional instantaneous, on model levels, at native resolution. MERRA, or the...
Beyond an assumed mother–child symbiosis in nutritional guidelines
DEFF Research Database (Denmark)
Nielsen, Annemette; Michaelsen, Kim F.; Holm, Lotte
2014-01-01
of the child and the interest and focus of the mother. The aim of this qualitative study was to explore mothers’ concerns and feeding practices in the context of everyday life. A total of 45 mothers with children either seven months old or 13 months old participated. The results showed that the need to find......Researchers question the implications of the way in which “motherhood” is constructed in public health discourse. Current nutritional guidelines for Danish parents of young children are part of this discourse. They are shaped by an assumed symbiotic relationship between the nutritional needs...... practical solutions for the whole family in a busy everyday life, to socialise the child into the family and society at large, and to create personal relief from the strain small children put on time and energy all served as socially acceptable reasons for knowingly departing from nutritional...
Representation of Instantaneous and Short-term Loudness in the Human Cortex
Directory of Open Access Journals (Sweden)
Andrew eThwaites
2016-04-01
Full Text Available Acoustic signals pass through numerous transforms in the auditory system before perceptual attributes such as loudness and pitch are derived. However, relatively little is known as to exactly when these transformations happen, and where, cortically or sub-cortically, they occur. In an effort to examine this, we investigated the latencies and locations of cortical entrainment to two transforms predicted by a model of loudness perception for time-varying sounds: the transforms were instantaneous loudness and short-term loudness, where the latter is hypothesized to be derived from the former and therefore should occur later in time. Entrainment of cortical activity was estimated by electro- and magneto-encephalographic (EMEG activity, recorded while healthy subjects listened to continuous speech. There was entrainment to instantaneous loudness bilaterally at 45 ms, 100 ms and 165 ms, in Heschl’s gyrus, dorsal lateral sulcus and Heschl’s gyrus respectively. Entrainment to short-term loudness was found in both the dorsal lateral sulcus and superior temporal sulcus at 275 ms. These results suggest that short-term loudness is derived from instantaneous loudness, and that this derivation occurs after processing in sub-cortical structures.
Instantaneous Optical Wall-Temperature of Vertical Two-Phase Annular Flow
Fehring, Brian; Livingston-Jha, Simon; Morse, Roman; Chan, Jason; Doherty, James; Brueggeman, Colby; Nellis, Gregory; Dressler, Kristofer; Berson, ArganthaëL.; Multiphase Flow Visualization; Analysis Laboratory at University of Wisconsin-Madison Team
2017-11-01
We present a non-invasive optical technique for measuring the instantaneous temperature at the inner wall of a flow duct. The technique is used to characterize a fully-developed vertical annular flow of R245fa refrigerant. The test section includes transparent heating windows made of glass coated with fluorine-doped tin-oxide. A 15 mW helium-neon laser is directed through a prism mounted on one of the glass windows and reflected off of the interface between the 150-micron-thick liquid film and the inside wall of the testing section window. The intensity of the laser light reflected at the liquid film-window interface depends on the index of refraction of liquid R245fa, which itself depends on the temperature of the fluid. The intensity of the reflected light is measured using a photodiode and calibrated to a light reflectance model based on the Fresnel equations and Snell's law. Instantaneous temperature data is combined with optical liquid film thickness measurements to calculate the local instantaneous heat transfer coefficient at the wall.
Instantaneous power theory and applications to power conditioning
Akagi, Hirofumi; Aredes, Mauricio
2017-01-01
This new edition, written by a team of experts in the field, is fully updated with information on the latest electric power technology. The instantaneous power theory, or “the p-q theory,” makes clear the physical meaning of what instantaneous real and imaginary power is in a three-phase circuit. Moreover, it provides insight into how energy flows from a source to a load, or circulates between phases, in a three-phase circuit. This theory can be used in the design and understanding of FACTS (Flexible AC Transmission System) compensators. The book introduces many concepts in the field of active filtering that are unique to this edition. It provides a study tool for final year undergraduate students, graduate students and engineers dealing ith harmonic pollution problems, reactive power compensation or power quality in general.
A Deterministic Entropy Based on the Instantaneous Phase Space Volume
Diebner, Hans H.; Rössler, Otto E.
1998-02-01
A deterministic entropic measure is derived for the time evolution of Newtonian N-particle systems based on the volume of the instantaneously occupied phase space (IOPS). This measure is found as a natural extension of Boltzmann's entropy. The instantaneous arrangement of the particles is exploited in the form of spatial correlations. The new entropy is a bridge between the time-dependent Boltzmann entropy, formulated on the basis of densities in the one-particle phase space, and the static Gibbs entropy which uses densities in the full phase space. We apply the new concept in a molecular dynamics simulation (MDS) using an exactly time reversible "discrete Newtonian equation of motion" recently derived from the fundamental principle of least action in discretized space-time. The simulation therefore is consistent with micro-time-reversibility. Entropy becomes an exact momentary observable in both time directions in fulfillment of a dream of Boltzmann.
Wave electromagnetic fields induced by instantaneous braking of charges
International Nuclear Information System (INIS)
Kon'kov, V.L.; Novikova, G.P.
1981-01-01
Exact expressions for wave electromagnetic fields during instantaneous braking of two differently charged discs uniformly moving in the opposite directions have been derived. Analysis of their properties has been made. It is shown that electromagnetic wave fields during instantaneous braking of charges have a tearing nature and the Umov-Poynting theorem in the integral form is realized only at a certain value of parameter α which determines charges rates at the moment of braking. The value of parameter α is in the ranges from 0.5 to √3/2. The wave field is formed already in the absence of motion of charged discs. It is a good example confirming the conclusion that in the case of nonstationary electromagnetic fields, performance of reaction force of the wave field can differ fram radiation energy [ru
Analysis of nonlinear behavior of loudspeakers using the instantaneous frequency
DEFF Research Database (Denmark)
Huang, Hai; Jacobsen, Finn
2003-01-01
It is well know that the weakest link in a sound reproduction chain is the loudspeaker. The most significant effect on the sound quality is nonlinear distortion of loudspeakers. Many methods are applied to analyze the nonlinear distortion of loudspeakers. Almost all of the methods are based...... on the Fourier transform. In this work, a new method using the instantaneous frequency is introduced for describing and characterizing loudspeaker nonlinearities. First, numerical integration is applied to simulate the nonlinearities of loudspeakers caused by two nonlinear parameters, force factor and stiffness......, separately. Then, a practical loudspeaker is used in an experiment and its nonlinear characteristics are analyzed with the instantaneous frequency. The results provide a clear physical interpretation of the nonlinearities of loudspeakers and will be useful for understanding the nonlinear behavior...
Application of MySQL in instantaneous profile gauge system
International Nuclear Information System (INIS)
Guo Xiaojing; Miao Jichen; Wu Zhifang
2011-01-01
As equipment in the hot rolling plate plant for online measurement of strip steel, the instantaneous profile gauge is used to measure instant crown of hot rolling strips and feed back the crown to the rolling mill to adjust strip profile. During the measurement, a large amount of data need to be stored reasonably for query, display, computation and other processing, while a database management software can make it happen. Based on such features of MySQL as small size, fast speed, low cost and open source codes, a database function was implemented in the instantaneous profile gauge for data storage, query and maintenance, by applying MySQL database management system and integrating with the control interface. (authors)
Isolation of Indonesian Cananga oil by instantaneous controlled pressure drop
2008-01-01
The isolation of cananga oil by a new process, Instantaneous Controlled Pressure Drop (DIC), was investigated. This process consists in heating the dry cananga (Cananga odorata Hook. fil. et Thomson,forma macrophylla) flowers for a short time period by steam, followed by an abrupt pressure drop into a vacuum (about 5 kPa). This pressure drop provokes auto-vaporization of the volatile compounds, puffing of flowers, breaking of cell walls and cooling. The effect of the process parameters, namel...
Automatic first-break picking using the instantaneous traveltime attribute
Saragiotis, Christos
2012-01-01
Picking the first breaks is an important step in seismic processing. The large volume of the seismic data calls for automatic and objective picking. We introduce a new automatic first-break picker, which uses specifically designed time windows and an iterative procedure based on the instantaneous traveltime attribute. The method is fast as it only uses a few FFT\\'s per trace. We demonstrate the effectiveness of this automatic method by applying it on real test data.
Voltage Sag Source Location Based on Instantaneous Energy Detection
DEFF Research Database (Denmark)
Chen, Zhe; Kong, Wei; Dong, Xinzhou
2008-01-01
Voltage sag is a major power quality problem, which could disrupt the operation of voltage-sensitive equipment. This paper presents the method based on variation components-based instantaneous energy for voltage sag source detection. Simulations have been performed to provide the thorough analysis...... for system with distributed generation units. The studies show that the presented method can effectively detect the location of voltage sag source....
Smooth and fast versus instantaneous quenches in quantum field theory
International Nuclear Information System (INIS)
Das, Sumit R.; Galante, Damián A.; Myers, Robert C.
2015-01-01
We examine in detail the relationship between smooth fast quantum quenches, characterized by a time scale δt, and instantaneous quenches, within the framework of exactly solvable mass quenches in free scalar field theory. Our earlier studies http://dx.doi.org/10.1103/PhysRevLett.112.171601 and http://dx.doi.org/10.1007/JHEP02(2015)167 highlighted that the two protocols remain distinct in the limit δt→0 because of the relation of the quench rate to the UV cut-off, i.e., 1/δt≪Λ always holds in the fast smooth quenches while 1/δt∼Λ for instantaneous quenches. Here we study UV finite quantities like correlators at finite spatial distances and the excess energy produced above the final ground state energy. We show that at late times and large distances (compared to the quench time scale) the smooth quench correlator approaches that for the instantaneous quench. At early times, we find that for small spatial separation and small δt, the correlator scales universally with δt, exactly as in the scaling of renormalized one point functions found in earlier work. At larger separation, the dependence on δt drops out. The excess energy density is finite (for finite mδt) and scales in a universal fashion for all d. However, the scaling behaviour produces a divergent result in the limit mδt→0 for d≥4, just as in an instantaneous quench, where it is UV divergent for d≥4. We argue that similar results hold for arbitrary interacting theories: the excess energy density produced is expected to diverge for scaling dimensions Δ>d/2.
Smooth and fast versus instantaneous quenches in quantum field theory
Energy Technology Data Exchange (ETDEWEB)
Das, Sumit R. [Department of Physics and Astronomy, University of Kentucky,505 Rose St, Lexington, KY 40506 (United States); Galante, Damián A. [Department of Applied Mathematics, University of Western Ontario,1151 Richmond Street, London, ON N6A 5B7 (Canada); Perimeter Institute for Theoretical Physics,55 Caroline St N, Waterloo, ON N2L 2Y5 (Canada); Kavli Institute for Theoretical Physics, University of California,Kohn Hall, Santa Barbara, CA 93106 (United States); Myers, Robert C. [Perimeter Institute for Theoretical Physics,55 Caroline St N, Waterloo, ON N2L 2Y5 (Canada)
2015-08-17
We examine in detail the relationship between smooth fast quantum quenches, characterized by a time scale δt, and instantaneous quenches, within the framework of exactly solvable mass quenches in free scalar field theory. Our earlier studies http://dx.doi.org/10.1103/PhysRevLett.112.171601 and http://dx.doi.org/10.1007/JHEP02(2015)167 highlighted that the two protocols remain distinct in the limit δt→0 because of the relation of the quench rate to the UV cut-off, i.e., 1/δt≪Λ always holds in the fast smooth quenches while 1/δt∼Λ for instantaneous quenches. Here we study UV finite quantities like correlators at finite spatial distances and the excess energy produced above the final ground state energy. We show that at late times and large distances (compared to the quench time scale) the smooth quench correlator approaches that for the instantaneous quench. At early times, we find that for small spatial separation and small δt, the correlator scales universally with δt, exactly as in the scaling of renormalized one point functions found in earlier work. At larger separation, the dependence on δt drops out. The excess energy density is finite (for finite mδt) and scales in a universal fashion for all d. However, the scaling behaviour produces a divergent result in the limit mδt→0 for d≥4, just as in an instantaneous quench, where it is UV divergent for d≥4. We argue that similar results hold for arbitrary interacting theories: the excess energy density produced is expected to diverge for scaling dimensions Δ>d/2.
Installation and commissioning of instantaneous dose rate monitoring system
Iaydjiev, Plamen
2018-01-01
INRNE-Sofia was working on the installation and commissioning of new instantaneous dose rate monitoring system for the GIF++ facility at CERN. The final device, containing an 8-channels readout board was designed and tested at the CERN facility during November 2017, in an irradiation campaign supported by the AIDA-2020 TA program. The system is designed to be fully integrated in the GIF++ control system and the data measured are available to the users.
Instantaneous phase mapping deflectometry for dynamic deformable mirror characterization
Trumper, Isaac; Choi, Heejoo
2017-09-01
We present an instantaneous phase mapping deflectometry (PMD) system in the context of measuring a continuous surface deformable mirror (DM). Deflectometry has a high dynamic range, enabling the full range of surfaces generated by the DM to be measured. The recent development of an instantaneous PMD system leverages the simple setup of the PMD system to measure dynamic objects with accuracy similar to an interferometer. To demonstrate the capabilities of this technology, we perform a linearity measurement of the actuator motion in a continuous surface DM, which is critical for closed loop control in adaptive optics applications. We measure the entire set of actuators across the DM as they traverse their full range of motion with a Shack-Hartman wavefront sensor, thereby obtaining the influence function. Given the influence function of each actuator, the DM can produce specific Zernike terms on its surface. We then measure the linearity of the Zernike modes available in the DM software using the instantaneous PMD system. By obtaining the relationship between modes, we can more accurately generate surface profiles composed of Zernike terms. This ability is useful for other dynamic freeform metrology applications that utilize the DM as a null component.
Instantaneous response to loading of biphasic connective tissue models
Czech Academy of Sciences Publication Activity Database
Hlaváček, Miroslav
2007-01-01
Roč. 52, č. 2 (2007), s. 149-161 ISSN 0001-7043 R&D Projects: GA ČR(CZ) GA103/07/0043 Institutional research plan: CEZ:AV0Z20710524 Keywords : articular cartilage * equilibrium compliance * instentaneous compliance Subject RIV: JJ - Other Materials
Comparison of two intelligent models to estimate the instantaneous ...
Indian Academy of Sciences (India)
Mostafa Zamani Mohiabadi
2017-07-25
Jul 25, 2017 ... Solar radiation incident on the earth's surface is a fundamental input for many aspects of climatology, hydrology, biology, and architecture. In addition, it is an important parameter in solar energy applications. Due to the high cost of the measuring instruments of solar radiation, many researchers.
The behavior of the instantaneous Poynting vector of symmetrical laser beams
CSIR Research Space (South Africa)
Litvin, IA
2012-06-01
Full Text Available In this work we investigate the behavior of the instantaneous Poynting vector of symmetrical paraxial laser beams, namely the modification of the instantaneous Poynting vector and the radiation pattern during propagation in free space for a variety...
Trajectory Simulation of Meteors Assuming Mass Loss and Fragmentation
Allen, Gary A., Jr.; Prabhu, Dinesh K.; Saunders, David A
2015-01-01
Program used to simulate atmospheric flight trajectories of entry capsules [1] Includes models of atmospheres of different planetary destinations - Earth, Mars, Venus, Jupiter, Saturn, Uranus, Titan, ... Solves 3--degrees of freedom (3DoF) equations for a single body treated as a point mass. Also supports 6-DoF trajectory simula4on and Monte Carlo analyses. Uses Fehlberg--Runge--Kuna (4th-5th order) time integraion with automaic step size control. Includes rotating spheroidal planet with gravitational field having a J2 harmonic. Includes a variety of engineering aerodynamic and heat flux models. Capable of specifying events - heatshield jettison, parachute deployment, etc. - at predefined altitudes or Mach number. Has material thermal response models of typical aerospace materials integrated.
Garcia, Cristian F.; Rivera, Marco E.; Rodriguez, Jose R.; Wheeler, Patrick; Pena, Ruben S.
2017-01-01
This paper presents the experimental valida¬tion of a predictive current control strategy with minimiza¬tion of the instantaneous reactive input power for a Four-Leg Indirect Matrix Converter (4Leg-IMC). The topology includes an input matrix converter stage, which provides the dc voltage for a four-leg voltage source converter (VSC) output stage. The VSC’s fourth leg provides a path for the zero sequence load current. The control technique is based on a finite control set model predictive con...
Color-singlet instantaneous potential in the coulomb gauge QCD
International Nuclear Information System (INIS)
Nakagawa, Yoshiyuki; Toki, Hiroshi; Nakamura, Atsushi; Saito, Takuya
2007-01-01
We study the Coulomb gauge confinement mechanism in the quenched lattice QCD simulations. It is found that the color-Coulomb instantaneous potential in the color-singlet channel between two quarks grows linearly at large distances; namely, the color-Coulomb interaction is a source of color confinement. However, the linearity of this potential remains even in the quark-gluon plasma phase. We discuss the relation between this thermal Coulomb-string tension and a magnetic scaling introduced as an infrared cutoff of the thermal QCD theory. (author)
Laboratory and field evaluation of instantaneous-reading dust instruments
International Nuclear Information System (INIS)
Thompson, E.M.; Treaftis, H.N.; Tomb, T.F.
1984-01-01
A study was conducted to evaluate two instantaneous-reading dust monitors that utilize the attenuation of beta rays to determine respirable mass-dust concentrations. The one monitor utilizes impaction to deposit the sample on a mylar substrate while the other monitor collects the sample on a glass fiber filter. Measurements obtained using test aerosols of coal, limestone, and silica dusts were compared to measurements obtained with the approved personal coal mine dust sampler. Instrument linearity was synthetically checked using mylar and formvar films of varying thickness. The monitor employing the glass fiber filters was also tested in underground coal mines
Is Polar Amplification Deeper and Stronger than Dynamicists Assume?
Scheff, J.; Maroon, E.
2017-12-01
In the CMIP multi-model mean under strong future warming, Arctic amplification is confined to the lower troposphere, so that the meridional gradient of warming reverses around 500 mb and the upper troposphere is characterized by strong "tropical amplification" in which warming weakens with increasing latitude. This model-derived pattern of warming maxima in the upper-level tropics and lower-level Arctic has become a canonical assumption driving theories of the large-scale circulation response to climate change. Yet, several lines of evidence and reasoning suggest that Arctic amplification may in fact extend through the entire depth of the troposphere, and/or may be stronger than commonly modeled. These include satellite Microwave Sounding Unit (MSU) temperature trends as a function of latitude and vertical level, the recent discovery that the extratropical negative cloud phase feedback in models is largely spurious, and the very strong polar amplification observed in past warm and lukewarm climates. Such a warming pattern, with deep, dominant Arctic amplification, would have very different implications for the circulation than a canonical CMIP-like warming: instead of slightly shifting poleward and strengthening, eddies, jets and cells might shift equatorward and considerably weaken. Indeed, surface winds have been mysteriously weakening ("stilling") at almost all stations over the last half-century or so, there has been no poleward shift in northern hemisphere circulation metrics, and past warm climates' subtropics were apparently quite wet (and their global ocean circulations were weak.) To explore these possibilities more deeply, we examine the y-z structure of warming and circulation changes across a much broader range of models, scenarios and time periods than the CMIP future mean, and use an MSU simulator to compare them to the satellite warming record. Specifically, we examine whether the use of historical (rather than future) forcing, AMIP (rather than CMIP
Instantaneous power flow determination for single-phase UPFC
Energy Technology Data Exchange (ETDEWEB)
Dobrucky, B.; Drozdy, S.; Pokorny, M.; Pavlanin, R. [Zilina Univ., Zilina (Slovakia)
2007-07-01
The parallel shunt active filter in a unified power flow conditioner (UPFC) can filter and compensate the reactive power of basic and higher current harmonics. This paper reported on a study in which a new theory of orthogonal transform was used to control a single-phase UPFC system and transform it into a two-axes system. In addition to estimating the load current phase shifts, the study also determined the instantaneous active and reactive powers. The new theory is based on the premise that ordinary single-phase quantity can be complemented by a virtual fictitious phase so that both of them will create an orthogonal system, as is usual in three-phase systems. The theory uses efficient methods of analysis, such as time-sub-optimal determination of fundamental harmonics; average- and/or root-mean-square values; or instantaneous reactive power methods. The load current phase shift can be used to compensate for voltage drops. This paper outlined a practical application of the method in a case of active and reactive power determination for single-phase UPFC. It also presented some examples of the successful simulation experiments results focused on regulation output voltage of UPFC. 9 refs., 13 figs., 1 appendix.
Instantaneous Frequency and Damping from Transient Ring-Down Data
Energy Technology Data Exchange (ETDEWEB)
Kuether, Robert J.; Brake, Matthew Robert
2015-10-01
Broadband impact excitation in structural dynamics is a common technique used to detect and characterize nonlinearities in mechanical systems since it excites many frequencies of a structure at once and can be applied with a variety of boundary conditions. Non-stationary time signals from transient ring-down measurements require time-frequency analysis tools to observe variations in frequency and energy dissipation as the response evolves. This work uses the short-time Fourier transform to estimate the instantaneous frequency and damping ratio from either measured or simulated transient ring-down data. By combining the discrete Fourier transform with an expanding or contracting window function that moves along the time axis, the resulting spectrum is used to estimate the instantaneous frequencies, damping and complex Fourier coefficients. This method is demonstrated on a multi-degree-of-freedom beam with a cubic spring attachment, and investigates the amplitudefrequency dependence in connection to the undamped nonlinear normal modes. A second example shows the results from experiment ring-down response on a beam with a lap joint, and reveals how the system behaves as energy dissipates.
International Nuclear Information System (INIS)
Roy, Sukanta; Ducoin, Antoine
2016-01-01
Highlights: • Two-dimensional unsteady simulations on a novel Savonius-style wind turbine. • Instantaneous behavior of drag and lift coefficients, and corresponding moment arms. • Effect of tip speed ratio on the instantaneous force coefficients and moments arms. • Effect of force coefficients and moment arms on the instantaneous moment and power. • Analysis of power and moment coefficients at different tip speed ratios. - Abstract: This paper aims to present a transient analysis on the forces acting on a novel two-bladed Savonius-style wind turbine. Two-dimensional unsteady Reynolds Averaged Navier Stokes equations are solved using shear stress transport k–ω turbulence model at a Reynolds number of 1.23 × 10 5 . The instantaneous longitudinal drag and lateral lift forces acting on each of the blades and their acting points are calculated. The corresponding moment arms responsible for the torque generation are obtained. Further, the effect of tip speed ratio on the force coefficients, moment arms and overall turbine performances are observed. Throughout the paper, the obtained results for the new design are discussed with reference to conventional semi-circular design of Savonius turbines. A significant performance improvement is achieved with the new design due to its increased lift and moment arm contribution as compared to the conventional design. More interestingly, the present study sets a platform for future aerodynamic research and improvements for Savonius-style wind turbines.
Instantaneous flow field above the free end of finite-height cylinders and prisms
International Nuclear Information System (INIS)
Rostamy, N.; Sumner, D.; Bergstrom, D.J.; Bugg, J.D.
2013-01-01
Highlights: • PIV measurements of the flow above the free end of finite-height bodies. • Effect of cross-sectional shape of the models on the instantaneous flow. • Small-scale structures generated by the separated shear layer were revealed. • Effect of aspect ratio on the reattachment of the separated flow on the free end. -- Abstract: The flow above the free ends of surface-mounted finite-height circular cylinders and square prisms was studied experimentally using particle image velocimetry (PIV). Cylinders and prisms with aspect ratios of AR = 9, 7, 5, and 3 were tested at a Reynolds number of Re = 4.2 × 10 4 . The bodies were mounted normal to a ground plane and were partially immersed in a turbulent zero-pressure-gradient boundary layer, where the boundary layer thickness relative to the body width was δ/D = 1.6. PIV measurements were made above the free ends of the bodies in a vertical plane aligned with the flow centreline. The present PIV results provide insight into the effects of aspect ratio and body shape on the instantaneous flow field. The recirculation zone under the separated shear layer is larger for the square prism of AR = 3 compared to the more slender prism of AR = 9. Also, for a square prism with low aspect ratio (AR = 3), the influence of the reverse flow over the free end surface becomes more significant compared to that for a higher aspect ratio (AR = 9). For the circular cylinder, a cross-stream vortex forms within the recirculation zone. As the aspect ratio of the cylinder decreases, the reattachment point of the separated flow on the free end surface moves closer to the trailing edge. For both the square prism and circular cylinder cases, the instantaneous velocity vector field and associated in-plane vorticity field revealed small-scale structures mostly generated by the separated shear layer
Assuming too much? Participatory water resource governance in South Africa.
Brown, Julia
2011-01-01
This paper argues that participation in natural resource management, which is often coupled with moves for more local ownership of decision making, is based on three sets of assumptions: about the role of the state, the universality of application of such approaches and the transformatory potential of institutional reform. The validity of these assumptions requires investigation in view of the rapid institutionalisation and scaling-up of participatory approaches, particularly in developing country contexts. Post-apartheid South Africa is widely recognised as a pioneer of participatory and devolutionary approaches, particularly in the field of water resources. It is 12 years since the promulgation of the forward-thinking 1998 National Water Act, and thus an opportune moment to reflect on South Africa's experiences of participatory governance. Drawing on empirical research covering the establishment of the first Catchment Management Agency, and the transformation of existing Irrigation Boards into more inclusive Water User Associations in the Inkomati Water Management Area, it emerges that there may be fundamental weaknesses in the participatory model and underlying assumptions, and indeed such approaches may actually reinforce inequitable outcomes: the legacy of long-established institutional frameworks and powerful actors therein continues to exert influence in post-apartheid South Africa, and has the potential to subvert the democratic and redistributive potential of the water reforms. It is argued that a reassessment of the role of the state is necessary: where there is extreme heterogeneity in challenging catchments more, rather than less, state intervention may be required to uphold the interests of marginalised groups and effect redistribution.
Diurnal cycle of the dust instantaneous direct radiative forcing over the Arabian Peninsula
Osipov, Sergey
2015-08-27
In this study we attempted to better quantify radiative effects of dust over the Arabian Peninsula and their dependence on input parameters. For this purpose we have developed a stand-alone column radiation transport model coupled with the Mie, T-matrix and geometric optics calculations and driven by reanalysis meteorological fields and atmospheric composition. Numerical experiments were carried out for a wide range of aerosol optical depths, including extreme values developed during the dust storm on 18–20 March 2012. Comprehensive ground-based observations and satellite retrievals were used to estimate aerosol optical properties, validate calculations and carry out radiation closure. The broadband surface albedo, fluxes at the bottom and top of the atmosphere as well as instantaneous dust radiative forcing were estimated both from the model and observations. Diurnal cycle of the shortwave instantaneous dust direct radiative forcing was studied for a range of aerosol and surface characteristics representative of the Arabian Peninsula. Mechanisms and parameters responsible for diurnal variability of the radiative forcing were evaluated. We found that intrinsic variability of the surface albedo and its dependence on atmospheric conditions, along with anisotropic aerosol scattering, are mostly responsible for diurnal effects.
Continuous-Variable Instantaneous Quantum Computing is Hard to Sample.
Douce, T; Markham, D; Kashefi, E; Diamanti, E; Coudreau, T; Milman, P; van Loock, P; Ferrini, G
2017-02-17
Instantaneous quantum computing is a subuniversal quantum complexity class, whose circuits have proven to be hard to simulate classically in the discrete-variable realm. We extend this proof to the continuous-variable (CV) domain by using squeezed states and homodyne detection, and by exploring the properties of postselected circuits. In order to treat postselection in CVs, we consider finitely resolved homodyne detectors, corresponding to a realistic scheme based on discrete probability distributions of the measurement outcomes. The unavoidable errors stemming from the use of finitely squeezed states are suppressed through a qubit-into-oscillator Gottesman-Kitaev-Preskill encoding of quantum information, which was previously shown to enable fault-tolerant CV quantum computation. Finally, we show that, in order to render postselected computational classes in CVs meaningful, a logarithmic scaling of the squeezing parameter with the circuit size is necessary, translating into a polynomial scaling of the input energy.
Instantaneous chemical profiles of banknotes by ambient mass spectrometry.
Eberlin, Livia S; Haddad, Renato; Sarabia Neto, Ramon C; Cosso, Ricardo G; Maia, Denison R J; Maldaner, Adriano O; Zacca, Jorge Jardim; Sanvido, Gustavo B; Romão, Wanderson; Vaz, Boniek G; Ifa, Demian R; Dill, Allison; Cooks, R Graham; Eberlin, Marcos N
2010-10-01
Using two desorption/ionization techniques (DESI and EASI) and Brazilian real, US$ dollar, and euro bills as proof-of-principle techniques and samples, direct analysis by ambient mass spectrometry is shown to function as an instantaneous, reproducible, and non-destructive method for chemical analysis of banknotes. Characteristic chemical profiles were observed for the authentic bills and for the counterfeit bills made using different printing processes (inkjet, laserjet, phaser and off-set printers). Detection of real-world counterfeit bills and identification of the counterfeiting method has also been demonstrated. Chemically selective 2D imaging of banknotes has also been used to confirm counterfeiting. The nature of some key diagnostic ions has also been investigated via high accuracy FTMS measurements. The general applicability of ambient MS analysis for anti-counterfeiting strategies particularly via the use of "invisible ink" markers is discussed.
Sundara Rajan, R.; Uthayakumar, R.
2017-12-01
In this paper we develop an economic order quantity model to investigate the optimal replenishment policies for instantaneous deteriorating items under inflation and trade credit. Demand rate is a linear function of selling price and decreases negative exponentially with time over a finite planning horizon. Shortages are allowed and partially backlogged. Under these conditions, we model the retailer's inventory system as a profit maximization problem to determine the optimal selling price, optimal order quantity and optimal replenishment time. An easy-to-use algorithm is developed to determine the optimal replenishment policies for the retailer. We also provide optimal present value of profit when shortages are completely backlogged as a special case. Numerical examples are presented to illustrate the algorithm provided to obtain optimal profit. And we also obtain managerial implications from numerical examples to substantiate our model. The results show that there is an improvement in total profit from complete backlogging rather than the items being partially backlogged.
Tsao, Yu-Chung
2016-02-01
This study models a joint location, inventory and preservation decision-making problem for non-instantaneous deteriorating items under delay in payments. An outside supplier provides a credit period to the wholesaler which has a distribution system with distribution centres (DCs). The non-instantaneous deteriorating means no deterioration occurs in the earlier stage, which is very useful for items such as fresh food and fruits. This paper also considers that the deteriorating rate will decrease and the reservation cost will increase as the preservation effort increases. Therefore, how much preservation effort should be made is a crucial decision. The objective of this paper is to determine the optimal locations and number of DCs, the optimal replenishment cycle time at DCs, and the optimal preservation effort simultaneously such that the total network profit is maximised. The problem is formulated as piecewise nonlinear functions and has three different cases. Algorithms based on piecewise nonlinear optimisation are provided to solve the joint location and inventory problem for all cases. Computational analysis illustrates the solution procedures and the impacts of the related parameters on decisions and profits. The results of this study can serve as references for business managers or administrators.
Kawamura, Hironao; Kozuka, Masahiro; Itamoto, Naoki; Shinjo, Kazuo; Ishii, Masaru
Lightning faults on transmission lines often cause instantaneous voltage drops in power systems. Influences of instantaneous voltage drops become increasingly serious in high technology industries etc. As countermeasures of instantaneous voltage drops, uninterruptible power supplies (UPS) are employed. On the other hand, line surge arresters are installed on transmission lines increasingly as one of the effective countermeasures of double-circuit faults caused by lightning strokes. Additionally, the arresters are effective as one of the reduction methods for the frequency of instantaneous voltage drops. In this paper, the frequency of instantaneous voltage drops reduced by installation of line surge arresters on transmission lines is estimated by employing EMTP analysis. Also, the accuracy of the method in estimating the frequency of instantaneous voltage drops in power systems is evaluated through comparison with experience.
International Nuclear Information System (INIS)
Viera, Juan P.; Payri, Raul; Swantek, Andrew B.; Duke, Daniel J.; Sovis, Nicolas; Kastengren, Alan L.; Powell, Christopher F.
2016-01-01
Highlights: • A direct-acting prototype diesel injector is utilized to control needle lift. • The effects of partial needle lift on rate of injection are analyzed. • Time-resolved needle lift is measured from fast phase-contrast X-ray images. • The link between instantaneous needle lift and rate of injection is analyzed. - Abstract: Internal combustion engines have been and still are key players in today’s world. Ever increasing fuel consumption standards and the ongoing concerns about exhaust emissions have pushed the industry to research new concepts and develop new technologies that address these challenges. To this end, the diesel direct injection system has recently seen the introduction of direct-acting piezoelectric injectors, which provide engineers with direct control over the needle lift, and thus instantaneous rate of injection (ROI). Even though this type of injector has been studied previously, no direct link between the instantaneous needle lift and the resulting rate of injection has been quantified. This study presents an experimental analysis of the relationship between instantaneous partial needle lifts and the corresponding ROI. A prototype direct-acting injector was utilized to produce steady injections of different magnitude by partially lifting the needle. The ROI measurements were carried out at CMT-Motores Térmicos utilizing a standard injection rate discharge curve indicator based on the Bosch method (anechoic tube). The needle lift measurements were performed at the Advanced Photon Source at Argonne National Laboratory. The analysis seeks both to contribute to the current understanding of the influence that partial needle lifts have over the instantaneous ROI and to provide experimental data with parametric variations useful for numerical model validations. Results show a strong relationship between the steady partial needle lift and the ROI. The effect is non-linear, and also strongly dependent on the injection pressure. The
Emergency cricothyrotomy for trismus caused by instantaneous rigor in cardiac arrest patients.
Lee, Jae Hee; Jung, Koo Young
2012-07-01
Instantaneous rigor as muscle stiffening occurring in the moment of death (or cardiac arrest) can be confused with rigor mortis. If trismus is caused by instantaneous rigor, orotracheal intubation is impossible and a surgical airway should be secured. Here, we report 2 patients who had emergency cricothyrotomy for trismus caused by instantaneous rigor. This case report aims to help physicians understand instantaneous rigor and to emphasize the importance of securing a surgical airway quickly on the occurrence of trismus. Copyright © 2012 Elsevier Inc. All rights reserved.
Instantaneous input electrical power measurements of HITU transducer
International Nuclear Information System (INIS)
Karaboece, B; Guelmez, Y; Rajagapol, S; Shaw, A
2011-01-01
HITU (High Intensity Theraupetic Ultrasound) transducers are widely used in therapeutic ultrasound in medicine. The output ultrasonic power of HITU transducer can be measured in number of methods described in IEC 61161 standard [1]. New IEC standards specifically for measurement of HITU equipment are under development. The ultrasound power radiated from a transducer is dependent on applied input electrical voltage and current and consequently power. But, up to now, no standardised method has been developed and adopted for the input electrical power measurements. Hence, a workpackage was carried out for the establishment of such method in the frequency range of 1 to 3 MHz as a part of EURAMET EMRP Era-net plus 'External Beam Cancer Therapy' project. Several current shunts were developed and evaluated. Current measurements were also realized with Philips current probe and preamplifier at NPL and Agilent current probe at UME. In this paper, a method for the measurement of instantaneous electrical power delivered to a reactive ultrasound transducer in the required frequency range is explored.
Covert waking brain activity reveals instantaneous sleep depth.
Directory of Open Access Journals (Sweden)
Scott M McKinney
Full Text Available The neural correlates of the wake-sleep continuum remain incompletely understood, limiting the development of adaptive drug delivery systems for promoting sleep maintenance. The most useful measure for resolving early positions along this continuum is the alpha oscillation, an 8-13 Hz electroencephalographic rhythm prominent over posterior scalp locations. The brain activation signature of wakefulness, alpha expression discloses immediate levels of alertness and dissipates in concert with fading awareness as sleep begins. This brain activity pattern, however, is largely ignored once sleep begins. Here we show that the intensity of spectral power in the alpha band actually continues to disclose instantaneous responsiveness to noise--a measure of sleep depth--throughout a night of sleep. By systematically challenging sleep with realistic and varied acoustic disruption, we found that sleepers exhibited markedly greater sensitivity to sounds during moments of elevated alpha expression. This result demonstrates that alpha power is not a binary marker of the transition between sleep and wakefulness, but carries rich information about immediate sleep stability. Further, it shows that an empirical and ecologically relevant form of sleep depth is revealed in real-time by EEG spectral content in the alpha band, a measure that affords prediction on the order of minutes. This signal, which transcends the boundaries of classical sleep stages, could potentially be used for real-time feedback to novel, adaptive drug delivery systems for inducing sleep.
Adaptive Window Zero-Crossing-Based Instantaneous Frequency Estimation
Directory of Open Access Journals (Sweden)
Sekhar S Chandra
2004-01-01
Full Text Available We address the problem of estimating instantaneous frequency (IF of a real-valued constant amplitude time-varying sinusoid. Estimation of polynomial IF is formulated using the zero-crossings of the signal. We propose an algorithm to estimate nonpolynomial IF by local approximation using a low-order polynomial, over a short segment of the signal. This involves the choice of window length to minimize the mean square error (MSE. The optimal window length found by directly minimizing the MSE is a function of the higher-order derivatives of the IF which are not available a priori. However, an optimum solution is formulated using an adaptive window technique based on the concept of intersection of confidence intervals. The adaptive algorithm enables minimum MSE-IF (MMSE-IF estimation without requiring a priori information about the IF. Simulation results show that the adaptive window zero-crossing-based IF estimation method is superior to fixed window methods and is also better than adaptive spectrogram and adaptive Wigner-Ville distribution (WVD-based IF estimators for different signal-to-noise ratio (SNR.
Development and evaluation of an instantaneous atmospheric corrosion rate monitor
Mansfeld, F.; Jeanjaquet, S. L.; Kendig, M. W.; Roe, D. K.
1985-06-01
A research program was carried out in which a new instantaneous atmospheric corrosion rate monitor (ACRM) was developed and evaluated, and equipment was constructed which will allow the use of many sensors in an economical way in outdoor exposures. In the first task, the ACRM was developed and tested in flow chambers in which relative humidity and gaseous and particulate pollutant levels can be controlled. Diurnal cycles and periods of rain were simulated. The effects of aerosols were studied. A computerized system was used for collection, storage, and analysis of the electrochemical data. In the second task, a relatively inexpensive electronics system for control of the ACRM and measurement of atmospheric corrosion rates was designed and built. In the third task, calibration of deterioration rates of various metallic and nonmetallic materials with the response of the ACRMs attached to these materials was carried out under controlled environmental conditions using the system developed in the second task. A Quality Assurance project plan was prepared with inputs from the Rockwell International Environmental Monitoring and Service Center and Quality Assurance System audits were performed.
Instantaneous Frequency Analysis on Nonlinear EMIC Emissions: Arase Observation
Shoji, M.; Yoshizumi, M.; Omura, Y.; Kasaba, Y.; Ishisaka, K.; Matsuda, S.; Kasahara, Y.; Yagitani, S.; Matsuoka, A.; Teramoto, M.; Takashima, T.; Shinohara, I.
2017-12-01
In the inner magnetosphere, electromagnetic ion cyclotron (EMIC) waves cause nonlinear interactions with energetic protons. The waves drastically modify the proton distribution function, resulting in the particle loss in the radiation belt. Arase spacecraft, launched in late 2016, observed a nonlinear EMIC falling tone emission in the high magnetic latitude (MLAT) region of the inner magnetosphere. The wave growth with sub-packet structures of the falling tone emission is found by waveform data from PWE/EFD instrument. The evolution of the instantaneous frequency of the electric field of the EMIC falling tone emission is analyzed by Hilbert-Huang transform (HHT). We find several sub-packets with rising frequency in the falling tone wave. A self-consistent hybrid simulation suggested the complicate frequency evolution of the EMIC sub-packet emissions in the generation region. The intrinsic mode functions of Arase data derived from HHT are compared with the simulation data. The origin of the falling tone emission in the high MLAT region is also discussed.
Instantaneous input electrical power measurements of HITU transducer
Energy Technology Data Exchange (ETDEWEB)
Karaboece, B; Guelmez, Y [Tuebitak Ulusal Metroloji Enstituesue (UME), P.K. 54 41470 Gebze-Kocaeli (Turkey); Rajagapol, S; Shaw, A, E-mail: baki.karaboce@ume.tubitak.gov.t [National Physical Laboratory (NPL), Hampton Road, Teddington TW11 0LW (United Kingdom)
2011-02-01
HITU (High Intensity Theraupetic Ultrasound) transducers are widely used in therapeutic ultrasound in medicine. The output ultrasonic power of HITU transducer can be measured in number of methods described in IEC 61161 standard [1]. New IEC standards specifically for measurement of HITU equipment are under development. The ultrasound power radiated from a transducer is dependent on applied input electrical voltage and current and consequently power. But, up to now, no standardised method has been developed and adopted for the input electrical power measurements. Hence, a workpackage was carried out for the establishment of such method in the frequency range of 1 to 3 MHz as a part of EURAMET EMRP Era-net plus 'External Beam Cancer Therapy' project. Several current shunts were developed and evaluated. Current measurements were also realized with Philips current probe and preamplifier at NPL and Agilent current probe at UME. In this paper, a method for the measurement of instantaneous electrical power delivered to a reactive ultrasound transducer in the required frequency range is explored.
Instantaneous stiffness and hysteresis of dynamic elastic response prosthetic feet.
Webber, Christina M; Kaufman, Kenton
2017-10-01
Dynamic elastic response prosthetic feet are designed to mimic the functional characteristics of the native foot/ankle joint. Numerous designs of dynamic elastic response feet exist which make the prescription process difficult, especially because of the lack of empirical evidence describing the objective performance characteristics of the feet. To quantify the mechanical properties of available dynamic elastic response prosthetic feet, specifically the stiffness and hysteresis. Mechanical testing of dynamic elastic response prosthetic feet. Static Proof Testing in accordance with ISO 10328 was conducted on seven dynamic elastic response prosthetic feet. Load-displacement data were used to calculate the instantaneous stiffness in both the heel and forefoot regions, as well as hysteresis associated with each foot. Heel stiffness was greater than forefoot stiffness for all feet. The heel of the glass composite prosthetic foot was stiffer than the carbon fiber feet and it exhibited less hysteresis. Two different carbon fiber feet had the stiffest forefoot regions. Mechanical testing is a reproducible method that can be used to provide objective evidence about dynamic elastic response prosthetic foot performance and aid in the prescription process. Clinical relevance The quantitative stiffness and hysteresis data from this study can be used by prosthetists to aid the prescription process and make it more objective.
Osipov, Sergey
2015-04-01
To better quantify radiative effects of dust over the Arabian Peninsula we have developed a standalone column radiation transport model coupled with the Mie calculations and driven by reanalysis meteorological fields and atmospheric composition. Numerical experiments are carried out for a wide range of aerosol optical depths, including extreme values developed during the dust storm on 18-20 March 2012. Comprehensive ground-based observations and satellite retrievals are used to estimate aerosol optical properties, validate calculations and carry out radiation closure. The broadband surface albedo, fluxes at the bottom and top of the atmosphere as well as instantaneous dust radiative forcing are estimated both from the model and from observations. Diurnal cycle of the the shortwave instantaneous dust direct radiative forcing is studied for a range of aerosol and surface characteristics representative for the Arabian Peninsula. Mechanisms and parameters responsible for diurnal variability of the radiative forcing are evaluated. We found that intrinsic variability of the surface albedo and its dependence on atmospheric conditions along with anisotropic aerosol scattering are mostly responsible for diurnal effects. We also discuss estimates of the climatological dust instantaneous direct radiative forcing over land and the Red Sea using two approaches. The first approach is based on the probability density function of the aerosol optical depth, and the second is based on the climatologically average Spinning Enhanced Visible and Infrared Imager (SEVIRI) aerosol optical depth. Results are compared with Geostationary Earth Radiation Budget (GERB) derived top of the atmosphere climatological forcing over the Red Sea.
Quantifying Uncertainty in Instantaneous Orbital Data Products of TRMM over Indian Subcontinent
Jayaluxmi, I.; Nagesh, D.
2013-12-01
In the last 20 years, microwave radiometers have taken satellite images of earth's weather proving to be a valuable tool for quantitative estimation of precipitation from space. However, along with the widespread acceptance of microwave based precipitation products, it has also been recognized that they contain large uncertainties. While most of the uncertainty evaluation studies focus on the accuracy of rainfall accumulated over time (e.g., season/year), evaluation of instantaneous rainfall intensities from satellite orbital data products are relatively rare. These instantaneous products are known to potentially cause large uncertainties during real time flood forecasting studies at the watershed scale. Especially over land regions, where the highly varying land surface emissivity offer a myriad of complications hindering accurate rainfall estimation. The error components of orbital data products also tend to interact nonlinearly with hydrologic modeling uncertainty. Keeping these in mind, the present study fosters the development of uncertainty analysis using instantaneous satellite orbital data products (version 7 of 1B11, 2A25, 2A23) derived from the passive and active sensors onboard Tropical Rainfall Measuring Mission (TRMM) satellite, namely TRMM microwave imager (TMI) and Precipitation Radar (PR). The study utilizes 11 years of orbital data from 2002 to 2012 over the Indian subcontinent and examines the influence of various error sources on the convective and stratiform precipitation types. Analysis conducted over the land regions of India investigates three sources of uncertainty in detail. These include 1) Errors due to improper delineation of rainfall signature within microwave footprint (rain/no rain classification), 2) Uncertainty offered by the transfer function linking rainfall with TMI low frequency channels and 3) Sampling errors owing to the narrow swath and infrequent visits of TRMM sensors. Case study results obtained during the Indian summer
Errors resulting from assuming opaque Lambertian clouds in TOMS ozone retrieval
International Nuclear Information System (INIS)
Liu, X.; Newchurch, M.J.; Loughman, R.; Bhartia, P.K.
2004-01-01
Accurate remote sensing retrieval of atmospheric constituents over cloudy areas is very challenging because of insufficient knowledge of cloud parameters. Cloud treatments are highly idealized in most retrieval algorithms. Using a radiative transfer model treating clouds as scattering media, we investigate the effects of assuming opaque Lambertian clouds and employing a Partial Cloud Model (PCM) on Total Ozone Mapping Spectrometer (TOMS) ozone retrievals, especially for tropical high-reflectivity clouds. Assuming angularly independent cloud reflection is good because the Ozone Retrieval Errors (OREs) are within 1.5% of the total ozone (i.e., within TOMS retrieval precision) when Cloud Optical Depth (COD)≥20. Because of Intra-Cloud Ozone Absorption ENhancement (ICOAEN), assuming opaque clouds can introduce large OREs even for optically thick clouds. For a water cloud of COD 40 spanning 2-12 km with 20.8 Dobson Unit (DU) ozone homogeneously distributed in the cloud, the ORE is 17.8 DU in the nadir view. The ICOAEN effect depends greatly on solar zenith angle, view zenith angle, and intra-cloud ozone amount and distribution. The TOMS PCM is good because negative errors from the cloud fraction being underestimated partly cancel other positive errors. At COD≤5, the TOMS algorithm retrieves approximately the correct total ozone because of compensating errors. With increasing COD up to 20-40, the overall positive ORE increases and is finally dominated by the ICOAEN effect. The ICOAEN effect is typically 5-13 DU on average over the Atlantic and Africa and 1-7 DU over the Pacific for tropical high-altitude (cloud top pressure ≤300 hPa) and high-reflectivity (reflectivity ≥ 80%) clouds. Knowledge of TOMS ozone retrieval errors has important implications for remote sensing of ozone/trace gases from other satellite instruments
National Aeronautics and Space Administration — The MAI6NVANA or inst6_3d_ana_Nv data product is the MERRA Data Assimilation System 3-Dimensional instantaneous, on model levels, at native resolution. MERRA, or the...
16 CFR Appendix D4 to Part 305 - Water Heaters-Instantaneous-Gas
2010-01-01
... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Water Heaters-Instantaneous-Gas D4 Appendix...) Pt. 305, App. D4 Appendix D4 to Part 305—Water Heaters-Instantaneous-Gas Range Information CAPACITY FIRST HOUR RATING Range of Estimated Annual Operating Costs (Dollars/Year) Natural Gas ($/year) Low High...
49 CFR 568.7 - Requirements for manufacturers who assume legal responsibility for a vehicle.
2010-10-01
... MANUFACTURED IN TWO OR MORE STAGES § 568.7 Requirements for manufacturers who assume legal responsibility for a vehicle. (a) If an incomplete vehicle manufacturer assumes legal responsibility for all duties and... 49 CFR 567.5(f). (b) If an intermediate manufacturer of a vehicle assumes legal responsibility for...
Depth-averaged instantaneous currents in a tidally dominated shelf sea from glider observations
Merckelbach, Lucas
2016-12-01
Ocean gliders have become ubiquitous observation platforms in the ocean in recent years. They are also increasingly used in coastal environments. The coastal observatory system COSYNA has pioneered the use of gliders in the North Sea, a shallow tidally energetic shelf sea. For operational reasons, the gliders operated in the North Sea are programmed to resurface every 3-5 h. The glider's dead-reckoning algorithm yields depth-averaged currents, averaged in time over each subsurface interval. Under operational conditions these averaged currents are a poor approximation of the instantaneous tidal current. In this work an algorithm is developed that estimates the instantaneous current (tidal and residual) from glider observations only. The algorithm uses a first-order Butterworth low pass filter to estimate the residual current component, and a Kalman filter based on the linear shallow water equations for the tidal component. A comparison of data from a glider experiment with current data from an acoustic Doppler current profilers deployed nearby shows that the standard deviations for the east and north current components are better than 7 cm s-1 in near-real-time mode and improve to better than 6 cm s-1 in delayed mode, where the filters can be run forward and backward. In the near-real-time mode the algorithm provides estimates of the currents that the glider is expected to encounter during its next few dives. Combined with a behavioural and dynamic model of the glider, this yields predicted trajectories, the information of which is incorporated in warning messages issued to ships by the (German) authorities. In delayed mode the algorithm produces useful estimates of the depth-averaged currents, which can be used in (process-based) analyses in case no other source of measured current information is available.
Energy Technology Data Exchange (ETDEWEB)
Araiza M, E.; Ortiz V, J.; Martinez C, E.; Amador G, R.; Castillo D, R., E-mail: enrique.araiza@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)
2016-09-15
This work presents the results of the simulation of the instantaneous closing of the water hammer, of a recirculation loop using two different arrangements in the loops. One of these arrangements corresponds to the traditional model that uses only two jet pumps to simulate the twenty pumps of the two recirculation loops of a BWR. The second nodalization models each of the ten jet pumps of each recirculation loop. The results obtained from the execution of both models are compared, using important variables such as pressures and mass costs for the same components of both models. In addition, the maximum pressure value generated on the pipe located upstream of the water hammer, relative to the design pressure of the pipe, is compared for each arrangement. (Author)
Elastic-plastic and creep analyses by assumed stress finite elements
International Nuclear Information System (INIS)
Pian, T.H.H.; Spilker, R.L.; Lee, S.W.
1975-01-01
A formulation is presented of incremental finite element solutions for both initial stress and initial strain problems based on modified complementary energy principle with relaxed inter-element continuity requirement. The corresponding finite element model is the assumed stress hybrid model which has stress parameters in the interior of each element and displacements at the individual nodes as unknowns. The formulation includes an important consideration that the states of stress and strain and the beginning of each increment may not satisfy the equilibrium and compatibility equations. These imbalance and mismatch conditions all lead to correction terms for the equivalent nodal forces of the matrix equations. The initial stress method is applied to elastic-plastic analysis of structures. In this case the stress parameters for the individual elements can be eliminated resulting to a system of equations with only nodal displacements as unknowns. Two different complementary energy principles can be formulated, in one of which the equilibrium of the final state of stress is maintained while in the other the equilibrium of the stress increments is maintained. Each of these two different formulations can be combined with different iterative schemes to be used at each incremental steps of the elastic-plastic analysis. It is also indicated clearly that for the initial stress method the state of stress at the beginning of each increments is in general, not in equilibrium and an imbalance correction is needed. Results of a comprehensive evaluation of various solution procedures by the initial stress method using the assumed stress hybrid elements are presented. The example used is the static response of a thick wall cylinder of elastic-perfectly plastic material under internal pressure. Solid of revolution elements with rectangular cross sections are used
Chen, Yu-Chun; Tang, Ping-Han; Wu, Ten-Ming
2013-11-01
By exploiting the instantaneous normal mode (INM) analysis for models of flexible molecules, we investigate intermolecular and intramolecular vibrations of water from the atomic point of view. With two flexible SPC/E models, our investigations include three aspects about their INM spectra, which are separated into the unstable, intermolecular, bending, and stretching bands. First, the O- and H-atom contributions in the four INM bands are calculated and their stable INM spectra are compared with the power spectra of the atomic velocity autocorrelation functions. The unstable and intermolecular bands of the flexible models are also compared with those of the SPC/E model of rigid molecules. Second, we formulate the inverse participation ratio (IPR) of the INMs, respectively, for the O- and H-atom and molecule. With the IPRs, the numbers of the three species participated in the INMs are estimated so that the localization characters of the INMs in each band are studied. Further, by the ratio of the IPR of the H atom to that of the O atom, we explore the number of involved OH bond per molecule participated in the INMs. Third, by classifying simulated molecules into subensembles according to the geometry of their local environments or their H-bond configurations, we examine the local-structure effects on the bending and stretching INM bands. All of our results are verified to be insensible to the definition of H-bond. Our conclusions about the intermolecular and intramolecular vibrations in water are given.
Chen, Yu-Chun; Tang, Ping-Han; Wu, Ten-Ming
2013-11-28
By exploiting the instantaneous normal mode (INM) analysis for models of flexible molecules, we investigate intermolecular and intramolecular vibrations of water from the atomic point of view. With two flexible SPC/E models, our investigations include three aspects about their INM spectra, which are separated into the unstable, intermolecular, bending, and stretching bands. First, the O- and H-atom contributions in the four INM bands are calculated and their stable INM spectra are compared with the power spectra of the atomic velocity autocorrelation functions. The unstable and intermolecular bands of the flexible models are also compared with those of the SPC/E model of rigid molecules. Second, we formulate the inverse participation ratio (IPR) of the INMs, respectively, for the O- and H-atom and molecule. With the IPRs, the numbers of the three species participated in the INMs are estimated so that the localization characters of the INMs in each band are studied. Further, by the ratio of the IPR of the H atom to that of the O atom, we explore the number of involved OH bond per molecule participated in the INMs. Third, by classifying simulated molecules into subensembles according to the geometry of their local environments or their H-bond configurations, we examine the local-structure effects on the bending and stretching INM bands. All of our results are verified to be insensible to the definition of H-bond. Our conclusions about the intermolecular and intramolecular vibrations in water are given.
Directory of Open Access Journals (Sweden)
Chandra K. Jaggi
2016-06-01
Full Text Available The present study investigates an inventory model for non-instantaneous deteriorating items under inflationary conditions with partially backlogged shortages. In today’s market structure consumers are looking for goods for which there is a delay in deterioration. At the same time, the consumers’ willingness to wait has been decreased over time, which leads to lost sales. Moreover in financial decision-making, the effects of inflation and time value of money cannot be oblivious to an inventory system. In this scenario, managing inventory of goods remains a challenging task for the decision makers, who may also have to rent warehouse under different prevailing factors such as, bulk discount, limited space in the retail outlet, or increasing inflation rates. With a focus on reduction of costs and increasing customer service, warehouse decision models are crucial for an organization’s profitability. Hence a mathematical model has been developed in the view of above scenario, in order to determine the optimal policy for the decision maker, by minimizing the present worth of total cost. The optimization procedure has been illustrated by a numerical example and detailed sensitivity analysis of the optimal solution has been performed to showcase the effect of various parameters. Managerial implications has also been presented to aid the decision making process.
Geomagnetic Components D, H, X, Y, Z, and R 10-second Instantaneous Measurements
National Oceanic and Atmospheric Administration, Department of Commerce — These data are generated as part of the International Magnetospheric Study. The file consists of 10-second instantaneous measurements for the geomagnetic components...
Energy Technology Data Exchange (ETDEWEB)
Sato, T.; Nishiyama, A. [Fuji Denki Reiki Co. Ltd., Tokyo (Japan)
1999-08-10
The market of automatic tea service machines demands sanitation, reduction in time required for pouring tea, feeding the material, cleaning the inside of the machine, the maintenance and service of the machine, and excellent design. To meet these demands, Fuji Electric has changed the former configuration and components for functions and has developed a new series of instantaneous automatic tea service machines based on a new concept. This paper outlines the advantages of the instantaneous cooling tank and improvements in handling. (author)
Processing of Instantaneous Angular Speed Signal for Detection of a Diesel Engine Failure
Directory of Open Access Journals (Sweden)
Adam Charchalis
2013-01-01
Full Text Available Continuous monitoring of diesel engine performance under its operating is critical for the prediction of malfunction development and subsequently functional failure detection. Analysis of instantaneous angular speed (IAS of the crankshaft is considered as one of the nonintrusive and effective methods of the detection of combustion quality deterioration. In this paper results of experimental verification of fuel system's malfunction detecting, using optical encoder for IAS recording are presented. The implemented method relies on the comparison of measurement results, recorded under healthy and faulty conditions of the engine. Elaborated dynamic model of angular speed variations enables us to build templates of engine behavior. Recorded during experiment, values of cylinder pressure were taken for the approximation of pressure basic waveform. The main task of data processing is smoothing the raw angular speed signal. The noise is due to sensor mount vibrations, signal emitter machining, engine body vibrations, and crankshaft torsional vibrations. Smoothing of the measurement data was carried out by the implementation of the Savitzky-Golay filter. Measured signal after smoothing was compared with the model of IAS run.
39 CFR 3060.40 - Calculation of the assumed Federal income tax.
2010-07-01
... Federal income tax. (a) The assumed Federal income tax on competitive products income shall be based on the Postal Service theoretical competitive products enterprise income statement for the relevant year... 39 Postal Service 1 2010-07-01 2010-07-01 false Calculation of the assumed Federal income tax...
Trujillo, Anna C.; Gregory, Irene M.
2014-01-01
Control-theoretic modeling of human operator's dynamic behavior in manual control tasks has a long, rich history. There has been significant work on techniques used to identify the pilot model of a given structure. This research attempts to go beyond pilot identification based on experimental data to develop a predictor of pilot behavior. Two methods for pre-dicting pilot stick input during changing aircraft dynamics and deducing changes in pilot behavior are presented This approach may also have the capability to detect a change in a subject due to workload, engagement, etc., or the effects of changes in vehicle dynamics on the pilot. With this ability to detect changes in piloting behavior, the possibility now exists to mediate human adverse behaviors, hardware failures, and software anomalies with autono-my that may ameliorate these undesirable effects. However, appropriate timing of when au-tonomy should assume control is dependent on criticality of actions to safety, sensitivity of methods to accurately detect these adverse changes, and effects of changes in levels of auto-mation of the system as a whole.
Yu, S. D.; Zhang, X.
2010-05-01
This paper presents a method for determining the instantaneous angular speed and instantaneous angular acceleration of the crankshaft in a reciprocating engine and propeller dynamical system from electrical pulse signals generated by a magnetic encoder. The method is based on accurate determination of the measured global mean angular speed and precise values of times when leading edges of individual magnetic teeth pass through the magnetic sensor. Under a steady-state operating condition, a discrete deviation time vs. shaft rotational angle series of uniform interval is obtained and used for accurate determination of the crankshaft speed and acceleration. The proposed method for identifying sub- and super-harmonic oscillations in the instantaneous angular speeds and accelerations is new and efficient. Experiments were carried out on a three-cylinder four-stroke Saito 450R model aircraft engine and a Solo propeller in connection with a 64-teeth Admotec KL2202 magnetic encoder and an HS-4 data acquisition system. Comparisons with an independent data processing scheme indicate that the proposed method yields noise-free instantaneous angular speeds and is superior to the finite difference based methods commonly used in the literature.
Influence of instantaneous wave effects on contaminant transport in beach aquifers
Robinson, C. E.; Malott, S. S.; O'Carroll, D. M.
2016-12-01
when instantaneous versus phase-averaged wave effects are considered. The study findings are needed for predicting contaminant behavior in coastal environments as well as to help frame a conceptual understanding of contaminant fate that can be validated by future field and modeling studies in wave-influenced coastal settings.
"Body-In-The-Loop": Optimizing Device Parameters Using Measures of Instantaneous Energetic Cost.
Felt, Wyatt; Selinger, Jessica C; Donelan, J Maxwell; Remy, C David
2015-01-01
This paper demonstrates methods for the online optimization of assistive robotic devices such as powered prostheses, orthoses and exoskeletons. Our algorithms estimate the value of a physiological objective in real-time (with a body "in-the-loop") and use this information to identify optimal device parameters. To handle sensor data that are noisy and dynamically delayed, we rely on a combination of dynamic estimation and response surface identification. We evaluated three algorithms (Steady-State Cost Mapping, Instantaneous Cost Mapping, and Instantaneous Cost Gradient Search) with eight healthy human subjects. Steady-State Cost Mapping is an established technique that fits a cubic polynomial to averages of steady-state measures at different parameter settings. The optimal parameter value is determined from the polynomial fit. Using a continuous sweep over a range of parameters and taking into account measurement dynamics, Instantaneous Cost Mapping identifies a cubic polynomial more quickly. Instantaneous Cost Gradient Search uses a similar technique to iteratively approach the optimal parameter value using estimates of the local gradient. To evaluate these methods in a simple and repeatable way, we prescribed step frequency via a metronome and optimized this frequency to minimize metabolic energetic cost. This use of step frequency allows a comparison of our results to established techniques and enables others to replicate our methods. Our results show that all three methods achieve similar accuracy in estimating optimal step frequency. For all methods, the average error between the predicted minima and the subjects' preferred step frequencies was less than 1% with a standard deviation between 4% and 5%. Using Instantaneous Cost Mapping, we were able to reduce subject walking-time from over an hour to less than 10 minutes. While, for a single parameter, the Instantaneous Cost Gradient Search is not much faster than Steady-State Cost Mapping, the Instantaneous
Evans, J.D.; Kember, G.C.; Major, G.
1992-01-01
The somatic shunt cable model for neurones is extended to the case in which several equivalent cylinders, not necessarily of the same electrotonic length, emanate from the cell soma. The cable equation is assumed to hold in each cylinder and is solved with sealed end conditions and a lumped soma boundary condition at a common origin. A Green's function (G) is defined, corresponding to the voltage response to an instantaneous current pulse at an arbitrary point along one of the cylinders. An e...
Instantaneous angular speed monitoring of gearboxes under non-cyclic stationary load conditions
Stander, C. J.; Heyns, P. S.
2005-07-01
Recent developments in the condition monitoring and asset management market have led to the commercialisation of online vibration-monitoring systems. These systems are primarily utilised to monitor large mineral mining equipment such as draglines, continuous miners and hydraulic shovels. Online monitoring systems make diagnostic information continuously available for asset management, production outsourcing and maintenance alliances with equipment manufacturers. However, most online vibration-monitoring systems are based on conventional vibration-monitoring technologies, which are prone to giving false equipment deterioration warnings on gears that operate under fluctuating load conditions. A simplified mathematical model of a gear system was developed to illustrate the feasibility of monitoring the instantaneous angular speed (IAS) as a means of monitoring the condition of gears that are subjected to fluctuating load conditions. A distinction is made between cyclic stationary load modulation and non-cyclic stationary load modulation. It is shown that rotation domain averaging will suppress the modulation caused by non-cyclic stationary load conditions but will not suppress the modulation caused by cyclic stationary load conditions. An experimental investigation on a test rig indicated that the IAS of a gear shaft could be monitored with a conventional shaft encoder to indicate a deteriorating gear fault condition.
Assuming it is all about conditions : Framing a simulation model for complex, adaptive urban space
Yamu, Claudia; de Roo, Gert; Frankhauser, Pierre
2016-01-01
In this paper, we explore the route beyond the conventional, linear attitude within planning and its rationality debate. We combine our theoretical reasoning with a multiscale approach and with fractal-like argumentation which results in a frame of conditions which is supported by the outline of a
Directory of Open Access Journals (Sweden)
Yang Zhao
2015-01-01
Full Text Available This paper presents a microfluidics-based approach capable of continuously characterizing instantaneous Young’s modulus (Einstantaneous and specific membrane capacitance (Cspecific membrane of suspended single cells. In this method, cells were aspirated through a constriction channel while the cellular entry process into the constriction channel was recorded using a high speed camera and the impedance profiles at two frequencies (1 kHz and 100 kHz were simultaneously measured by a lock-in amplifier. Numerical simulations were conducted to model cellular entry process into the constriction channel, focusing on two key parameters: instantaneous aspiration length (Linstantaneous and transitional aspiration length (Ltransitional, which was further translated to Einstantaneous. An equivalent distribution circuit model for a cell travelling in the constriction channel was used to determine Cspecific membrane. A non-small-cell lung cancer cell line 95C (n = 354 was used to evaluate this technique, producing Einstantaneous of 2.96 ± 0.40 kPa and Cspecific membrane of 1.59 ± 0.28 μF/cm2. As a platform for continuous and simultaneous characterization of cellular Einstantaneous and Cspecific membrane, this approach can facilitate a more comprehensive understanding of cellular biophysical properties.
Nessel, James; Zemba, Michael; Luini, Lorenzo; Riva, Carlo
2015-01-01
Rain attenuation is strongly dependent on the rain rate, but also on the rain drop size distribution (DSD). Typically, models utilize an average drop size distribution, such as those developed by Laws and Parsons, or Marshall and Palmer. However, individual rain events may possess drop size distributions which could be significantly different from the average and will impact, for example, fade mitigation techniques which utilize channel performance estimates from a signal at a different frequency. Therefore, a good understanding of the characteristics and variability of the raindrop size distribution is extremely important in predicting rain attenuation and instantaneous frequency scaling parameters on an event-toevent basis. Since June 2014, NASA Glenn Research Center (GRC) and the Politecnico di Milano (POLIMI) have measured the attenuation due to rain in Milan, Italy, on the 20/40 GHz beacon signal broadcast from the Alphasat TDP#5 Aldo Paraboni Q/V-band Payload. Concomitant with these measurements are the measurements of drop size distribution and rain rate utilizing a Thies Clima laser precipitation monitor (disdrometer). In this paper, we discuss the comparison of the predicted rain attenuation at 20 and 40 GHz derived from the drop size distribution data with the measured rain attenuation. The results are compared on statistical and real-time bases. We will investigate the performance of the rain attenuation model, instantaneous frequency scaling, and the distribution of the scaling factor. Further, seasonal rain characteristics will be analysed.
Monti, Alessandro; Médigue, Claire; Mangin, Laurence
2002-12-01
Time-frequency distributions, such as smoothed pseudo Wigner-Ville distribution (SPWVD), complex demodulation (CDM), and provide useful time-varying spectral parameter estimators. However, each of these methods has limitations that a joint utilization could largely reduce, due to their interesting complementary features. The aim of this paper is to validate the joint SPWVD-CDM method on synthetic and real cardiovascular time series with normal and reduced variability such as in autonomic blockade or autonomic deficiency. We propose two indexes related to the noise present in the signal and to the dispersion of the power spectrum in order to validate instantaneous parameter estimation. In the low-frequency band, the interpretation of the instantaneous frequency and phase of cardiovascular time-series should be discarded in many real-life situations. Conversely, in the high frequency band, under paced breathing, the reliability of the instantaneous parameters is demonstrated even in conditions of reduced cardiovascular variability.
Rishab, Paudel; Ishikawa, Hiroki; Naitoh, Haruo
This paper presents a novel strategy for torque ripple minimization with instantaneous current feedback compensation for switched reluctance motors (SRMs). The authors have already proposed suitable reference current profiles and a control algorithm to obtain an instantaneously flat torque of an SRM and confirmed the effectiveness of the algorithm by performing experiment in the low-speed range. In the high-speed range, however, the winding current cannot track the reference current owing to the lack of necessary voltage. In this study, mathematical analyses on the inability to trace the current profiles are performed. A new current control with compensation of the current profiles with instantaneous feedback is proposed. The validity of the proposed control is demonstrated by the experimental results.
Prospects for carbon capture and sequestration technologies assuming their technological learning
International Nuclear Information System (INIS)
Riahi, Keywan; Rubin, Edward S.; Schrattenholzer, Leo
2004-01-01
This paper analyzes potentials of carbon capture and sequestration technologies (CCS) in a set of long-term energy-economic-environmental scenarios based on alternative assumptions for technological progress of CCS. In order to get a reasonable guide to future technological progress in managing CO 2 emissions, we review past experience in controlling sulfur dioxide emissions (SO 2 ) from power plants. By doing so, we quantify a 'learning curve' for CCS, which describes the relationship between the improvement of costs due to accumulation of experience in CCS construction. We incorporate the learning curve into the energy modeling framework MESSAGE-MACRO and develop greenhouse gas emissions scenarios of economic, demographic, and energy demand development, where alternative policy cases lead to the stabilization of atmospheric CO 2 concentrations at 550 parts per million by volume (ppmv) by the end of the 21st century. Due to the assumed technological learning, costs of the emissions reduction for CCS drop rapidly and in parallel with the massive introduction of CCS on the global scale. Compared to scenarios based on static cost assumptions for CCS, the contribution of carbon sequestration is about 50 percent higher in the case of learning resulting in cumulative sequestration of CO 2 ranging from 150 to 250 billion (10 9 ) tons carbon during the 21st century. The results illustrate that carbon capture and sequestration is one of the obvious priority candidates for long-term technology policies and enhanced R and D efforts to hedge against the risk associated with high environmental impacts of climate change
Instantaneous Tunneling Flight Time for Wavepacket Transmission through Asymmetric Barriers.
Petersen, Jakob; Pollak, Eli
2018-04-12
The time it takes a particle to tunnel through the asymmetric Eckart barrier potential is investigated using Gaussian wavepackets, where the barrier serves as a model for the potential along a chemical reaction coordinate. We have previously shown that the, in principle experimentally measurable, tunneling flight time, which determines the time taken by the transmitted particle to traverse the barrier, vanishes for symmetric potentials like the Eckart and square barrier [ Petersen , J. ; Pollak , E. J. Phys. Chem. Lett. 2017 , 9 , 4017 ]. Here we show that the same result is obtained for the asymmetric Eckart barrier potential, and therefore, the zero tunneling flight time seems to be a general result for one-dimensional time-independent potentials. The wavepacket dynamics is simulated using both an exact quantum mechanical method and a classical Wigner prescription. The excellent agreement between the two methods shows that quantum coherences are not important in pure one-dimensional tunneling and reinforces the conclusion that the tunneling flight time vanishes.
Assuming a Pharmacy Organization Leadership Position: A Guide for Pharmacy Leaders.
Shay, Blake; Weber, Robert J
2015-11-01
Important and influential pharmacy organization leadership positions, such as president, board member, or committee chair, are volunteer positions and require a commitment of personal and professional time. These positions provide excellent opportunities for leadership development, personal promotion, and advancement of the profession. In deciding to assume a leadership position, interested individuals must consider the impact on their personal and professional commitments and relationships, career planning, employer support, current and future department projects, employee support, and personal readiness. This article reviews these factors and also provides an assessment tool that leaders can use to determine their readiness to assume leadership positions. By using an assessment tool, pharmacy leaders can better understand their ability to assume an important and influential leadership position while achieving job and personal goals.
Modeling auditory evoked brainstem responses to transient stimuli
DEFF Research Database (Denmark)
Rønne, Filip Munch; Dau, Torsten; Harte, James
2012-01-01
A quantitative model is presented that describes the formation of auditory brainstem responses (ABR) to tone pulses, clicks and rising chirps as a function of stimulation level. The model computes the convolution of the instantaneous discharge rates using the “humanized” nonlinear auditory......-nerve (AN) model of Zilany and Bruce (2007) and an empirically derived unitary response function which is assumed to reflect contributions from different cell populations within the auditory brainstem, recorded at a given pair of electrodes on the scalp. It is shown that the model accounts for the decrease...
Bowing-reactivity trends in EBR-II assuming zero-swelling ducts
International Nuclear Information System (INIS)
Meneghetti, D.
1994-01-01
Predicted trends of duct-bowing reactivities for the Experimental Breeder Reactor II (EBR-II) are correlated with predicted row-wise duct deflections assuming use of idealized zero-void-swelling subassembly ducts. These assume no irradiation induced swellings of ducts but include estimates of the effects of irradiation-creep relaxation of thermally induced bowing stresses. The results illustrate the manners in which at-power creeps may affect subsequent duct deflections at zero power and thereby the trends of the bowing component of a subsequent power reactivity decrement
Numerical analysis of dependence between adapted mesh and assumed error indicator
Kucwaj, Jan
2018-01-01
The paper considers the influence of the assumed error indicator on the final adapted mesh. Provided that threshold values of an error are increased by applying the adaptive procedure, it turns out that final mesh depends on the assumed error indicator. In the paper, there were used the standard error estimates and the error indicator proposed by the author. The proposed error indicator is based on applying hierarchically generalized finite difference method (FDM). In the case of the proposed error indicator, the final adapted mesh is the most optimal for the exact solution.
Van Gompel, Jamie J; Chang, Su-Youne; Goerss, Stephan J; Kim, In Yong; Kimble, Christopher; Bennet, Kevin E; Lee, Kendall H
2010-08-01
Deep brain stimulation (DBS) is effective when there appears to be a distortion in the complex neurochemical circuitry of the brain. Currently, the mechanism of DBS is incompletely understood; however, it has been hypothesized that DBS evokes release of neurochemicals. Well-established chemical detection systems such as microdialysis and mass spectrometry are impractical if one is assessing changes that are happening on a second-to-second time scale or for chronically used implanted recordings, as would be required for DBS feedback. Electrochemical detection techniques such as fast-scan cyclic voltammetry (FSCV) and amperometry have until recently remained in the realm of basic science; however, it is enticing to apply these powerful recording technologies to clinical and translational applications. The Wireless Instantaneous Neurochemical Concentration Sensor (WINCS) currently is a research device designed for human use capable of in vivo FSCV and amperometry, sampling at subsecond time resolution. In this paper, the authors review recent advances in this electrochemical application to DBS technologies. The WINCS can detect dopamine, adenosine, and serotonin by FSCV. For example, FSCV is capable of detecting dopamine in the caudate evoked by stimulation of the subthalamic nucleus/substantia nigra in pig and rat models of DBS. It is further capable of detecting dopamine by amperometry and, when used with enzyme linked sensors, both glutamate and adenosine. In conclusion, WINCS is a highly versatile instrument that allows near real-time (millisecond) detection of neurochemicals important to DBS research. In the future, the neurochemical changes detected using WINCS may be important as surrogate markers for proper DBS placement as well as the sensor component for a "smart" DBS system with electrochemical feedback that allows automatic modulation of stimulation parameters. Current work is under way to establish WINCS use in humans.
Directory of Open Access Journals (Sweden)
Heike Wendt
2017-03-01
Full Text Available Abstract Background Large-scale cross-national studies designed to measure student achievement use different social, cultural, economic and other background variables to explain observed differences in that achievement. Prior to their inclusion into a prediction model, these variables are commonly scaled into latent background indices. To allow cross-national comparisons of the latent indices, measurement invariance is assumed. However, it is unclear whether the assumption of measurement invariance has some influence on the results of the prediction model, thus challenging the reliability and validity of cross-national comparisons of predicted results. Methods To establish the effect size attributed to different degrees of measurement invariance, we rescaled the ‘home resource for learning index’ (HRL for the 37 countries ( $$n=166,709$$ n = 166 , 709 students that participated in the IEA’s combined ‘Progress in International Reading Literacy Study’ (PIRLS and ‘Trends in International Mathematics and Science Study’ (TIMSS assessments of 2011. We used (a two different measurement models [one-parameter model (1PL and two-parameter model (2PL] with (b two different degrees of measurement invariance, resulting in four different models. We introduced the different HRL indices as predictors in a generalized linear mixed model (GLMM with mathematics achievement as the dependent variable. We then compared three outcomes across countries and by scaling model: (1 the differing fit-values of the measurement models, (2 the estimated discrimination parameters, and (3 the estimated regression coefficients. Results The least restrictive measurement model fitted the data best, and the degree of assumed measurement invariance of the HRL indices influenced the random effects of the GLMM in all but one country. For one-third of the countries, the fixed effects of the GLMM also related to the degree of assumed measurement invariance. Conclusion The
The Quest for Instantaneous Perfection and the Demand for "Push-Button" Administration
Batagiannis, Stella C.
2009-01-01
Educational leaders in the United States are faced with a society seeking instantaneous perfection, immediate and perfect solutions. In education, this leads to a demand for push-button administration and an abandonment of trust in educators' judgment. As exemplified by the No Child Left Behind Act (2002), the search for quick fixes results in…
The instantaneous torque-angular velocity relation in plantar flexion during jumping
van Ingen Schenau, G J; Bobbert, M F; Huijing, P A; Woittiez, R D
Torques, angular velocities, and power of the ankle joint during plantar flexion were measured in jumping experiments in order to achieve insight into shape and magnitude of the instantaneous torque-angular velocity relation in a complex movement. Twelve trained subjects performed maximal vertical
DEFF Research Database (Denmark)
Henriksen, Niels Engholm; Møller, Klaus Braagaard
2003-01-01
In molecular electronic transitions, a vertical transition can be induced by an ultrashort laser pulse. That is, a replica of the initial nuclear state-times the transition dipole moment of the electronic transition-can be created instantaneously (on the time scale of nuclear motion) in the excited...
On-chip photonic-assisted instantaneous microwave frequency measurement system
Marpaung, D.A.I.
2013-01-01
A novel instantaneous frequency measurement system based on a programmable photonic chip frequency discriminator is experimentally demonstrated. The microwave signal whose frequency is to be measured is used to modulate the phase of an optical carrier. An optical ring resonator (ORR) in an add-drop
Use of the Instantaneous Wave-free Ratio or Fractional Flow Reserve in PCI
Davies, Justin E.; Sen, Sayan; Dehbi, Hakim-Moulay; Al-Lamee, Rasha; Petraco, Ricardo; Nijjer, Sukhjinder S.; Bhindi, Ravinay; Lehman, Sam J.; Walters, Darren; Sapontis, James; Janssens, Luc; Vrints, Christiaan J.; Khashaba, Ahmed; Laine, Mika; van Belle, Eric; Krackhardt, Florian; Bojara, Waldemar; Going, Olaf; Härle, Tobias; Indolfi, Ciro; Niccoli, Giampaolo; Ribichini, Flavo; Tanaka, Nobuhiro; Yokoi, Hiroyoshi; Takashima, Hiroaki; Kikuta, Yuetsu; Erglis, Andrejs; Vinhas, Hugo; Canas Silva, Pedro; Baptista, Sérgio B.; Alghamdi, Ali; Hellig, Farrel; Koo, Bon-Kwon; Nam, Chang-Wook; Shin, Eun-Seok; Doh, Joon-Hyung; Brugaletta, Salvatore; Alegria-Barrero, Eduardo; Meuwissen, Martijin; Piek, Jan J.; van Royen, Niels; Sezer, Murat; Di Mario, Carlo; Gerber, Robert T.; Malik, Iqbal S.; Sharp, Andrew S. P.; Talwar, Suneel; Tang, Kare; Samady, Habib; Altman, John; Seto, Arnold H.; Singh, Jasvindar; Jeremias, Allen; Matsuo, Hitoshi; Kharbanda, Rajesh K.; Patel, Manesh R.; Serruys, Patrick; Escaned, Javier
2017-01-01
Coronary revascularization guided by fractional flow reserve (FFR) is associated with better patient outcomes after the procedure than revascularization guided by angiography alone. It is unknown whether the instantaneous wave-free ratio (iFR), an alternative measure that does not require the
Correction for adiabatic effects in lethe calculated instantaneous gas consumption of scuba dives
Schellart, Nico A. M.; Le Péchon, Jean-Claude
2015-01-01
Introduction: In scuba-diving practice, instantaneous gas consumption is generally calculated from the fall in cylinder pressure without considering the effects of water temperature (heat transfer) and adiabatic processes. We aimed to develop a simple but precise method for calculating the
Varley, Matthew C; Fairweather, Ian H; Aughey, Robert J
2012-01-01
In this study, we assessed the validity and reliability of 5 and 10 Hz global positioning systems (GPS) for measuring instantaneous velocity during acceleration, deceleration, and constant velocity while straight-line running. Three participants performed 80 running trials while wearing two GPS units each (5 Hz, V2.0 and 10 Hz, V4.0; MinimaxX, Catapult Innovations, Scoresby, VIC, Australia). The criterion measure used to assess GPS validity was instantaneous velocity recorded using a tripod-mounted laser. Validity was established using the standard error of the estimate (± 90% confidence limits). Reliability was determined using typical error (± 90% confidence limits, expressed as coefficient of variation) and Pearson's correlation. The 10 Hz GPS devices were two to three times more accurate than the 5 Hz devices when compared with a criterion value for instantaneous velocity during tasks completed at a range of velocities (coefficient of variation 3.1-11.3%). Similarly, the 10 Hz GPS units were up to six-fold more reliable for measuring instantaneous velocity than the 5 Hz units (coefficient of variation 1.9-6.0%). Newer GPS may provide an acceptable tool for the measurement of constant velocity, acceleration, and deceleration during straight-line running and have sufficient sensitivity for detecting changes in performance in team sport. However, researchers must account for the inherent match-to-match variation reported when using these devices.
Instantaneous response spectrum in seismic testing of nuclear power plant equipment
International Nuclear Information System (INIS)
Morrone, A.
1977-01-01
This paper presents the concept of instantaneous response spectrum (IRS) as the response of single degree of freedom oscillators at a particular time. It demonstrates that a shake table random motion whose standard TRS envelops the RRS does not necessarily satisfy the enveloping requirement instantaneously. That is, any one (or more) instantaneous required response spectrum (IRRS) is not enveloped by any instantaneous test response spectrum (ITRS). Response spectra from different time histories, including single frequency sine beat motion used in resonance testing, are compared for enveloping with maximum response and with the actual response at particular times. These comparisons are given for the enveloping of RRS and IRRS derived with a time history response calculated at a particular building elevation of a nuclear power plant. For the test motion, several of the most severe ITRS derived with a modified EL Centro motion and with a sine beat motion with ten cycles per beat were used. It is shown that although the TRS with the modified EL Centro motion enveloped the given RRS, the selected modified EL Centro ITRS did not envelop the corresponding IRRS. With the sine beat motion, even though the TRS did not fully envelop the given RRS, the resulting sine beat ITRS did not require a larger factor for full IRRS enveloping than those of the modified EL Centro motion
Zemba, Michael; Nessel, James; Houts, Jacquelynne; Luini, Lorenzo; Riva, Carlo
2016-01-01
The rain rate data and statistics of a location are often used in conjunction with models to predict rain attenuation. However, the true attenuation is a function not only of rain rate, but also of the drop size distribution (DSD). Generally, models utilize an average drop size distribution (Laws and Parsons or Marshall and Palmer. However, individual rain events may deviate from these models significantly if their DSD is not well approximated by the average. Therefore, characterizing the relationship between the DSD and attenuation is valuable in improving modeled predictions of rain attenuation statistics. The DSD may also be used to derive the instantaneous frequency scaling factor and thus validate frequency scaling models. Since June of 2014, NASA Glenn Research Center (GRC) and the Politecnico di Milano (POLIMI) have jointly conducted a propagation study in Milan, Italy utilizing the 20 and 40 GHz beacon signals of the Alphasat TDP#5 Aldo Paraboni payload. The Ka- and Q-band beacon receivers provide a direct measurement of the signal attenuation while concurrent weather instrumentation provides measurements of the atmospheric conditions at the receiver. Among these instruments is a Thies Clima Laser Precipitation Monitor (optical disdrometer) which yields droplet size distributions (DSD); this DSD information can be used to derive a scaling factor that scales the measured 20 GHz data to expected 40 GHz attenuation. Given the capability to both predict and directly observe 40 GHz attenuation, this site is uniquely situated to assess and characterize such predictions. Previous work using this data has examined the relationship between the measured drop-size distribution and the measured attenuation of the link]. The focus of this paper now turns to a deeper analysis of the scaling factor, including the prediction error as a function of attenuation level, correlation between the scaling factor and the rain rate, and the temporal variability of the drop size
The Ability to Assume the Upright Position in Blind and Sighted Children.
Gipsman, Sandra Curtis
To investigate the ability of 48 blind and partially sighted children (8 to 10 and 12 to 14 years old) to assume the upright position, Ss were given six trials in which they were requested to move themselves from a tilted starting position in a specially constructed chair to an upright position. No significant differences were found between three…
Anti-periodic solutions for recurrent neural networks without assuming global Lipschitz conditions
Directory of Open Access Journals (Sweden)
Hong Zhang
2010-04-01
Full Text Available In this paper we study recurrent neural networks with time-varying delays and continuously distributed delays. Without assuming global Lipschitz conditions on the activation functions, we establish the existence and local exponential stability of anti-periodic solutions.
Does the Advice to Assume the Knee-Chest Position at the 36th to ...
African Journals Online (AJOL)
of the intervention group assumed the knee-chest position for 15 minutes three times a day for one week. The control group had 53 cases. The study and control groups were reviewed after a week to assess the fetal presentation. The version rate was 61% and 20% in intervention and in control groups, respectively (P value ...
Erkelens, J.S.; Hendriks, R.C.; Heusdens, R.
2008-01-01
This letter considers the estimation of speech signals contaminated by additive noise in the discrete Fourier transform (DFT) domain. Existing complex-DFT estimators assume independency of the real and imaginary parts of the speech DFT coefficients, although this is not in line with measurements. In
International Nuclear Information System (INIS)
Takeda, H.; Isha, H.
1981-01-01
The paper is concerned with the displacement-assumed-finite elements by applying the reduced numerical integration technique in structural problems. The first part is a general consideration on the technique. Its purpose is to examine a variational interpretation of the finite element displacement formulation with the reduced integration technique in structural problems. The formulation is critically studied from a standpoint of the natural stiffness approach. It is shown that these types of elements are equivalent to a certain type of displacement and stress assumed mixed elements. The rank deficiency of the stiffness matrix of these elements is interpreted as a problem in the transformation from the natural system to a Cartesian system. It will be shown that a variational basis of the equivalent mixed formulation is closely related to the Hellinger-Reissner's functional. It is presented that for simple elements, e.g. bilinear quadrilateral plane stress and plate bending there are corresponding mixed elements from the functional. For relatively complex types of these elements, it is shown that they are equivalent to localized mixed elements from the Hellinger-Reissner's functional. In the second part, typical finite elements with the reduced integration technique are studied to demonstrate this equivalence. A bilinear displacement and rotation assumed shear beam element, a bilinear displacement assumed quadrilateral plane stress element and a bilinear deflection and rotation assumed quadrilateral plate bending element are examined to present equivalent mixed elements. Not only the theoretical consideration is presented but numerical studies are shown to demonstrate the effectiveness of these elements in practical analysis. (orig.)
Koller, Jeffrey R; Gates, Deanna H; Ferris, Daniel P; Remy, C David
2017-02-01
Lower extremity robotic prostheses and exoskeletons can require tuning a large number of control parameters on a subject-specific basis to reduce users' metabolic power during locomotion. We refer to the functional relationship between control parameter configurations and users' metabolic power as the metabolic cost landscape. Standard practice for estimating a metabolic cost landscape, and thus identifying optimal parameter configurations, is to vary control parameters while measuring steady-state metabolic power during walking. This approach is time consuming, tedious, and inefficient. We have developed an instantaneous cost mapping analysis that allows for an estimate of the metabolic cost landscape without the explicit need for steady-state measurements. Here we present novel methods to quantify the confidence in an estimated metabolic cost landscape, allowing for an objective subject-specific comparison of protocols regardless of which metabolic analysis is used. We validated these techniques by estimating metabolic cost landscapes for healthy subjects walking with bilateral robotic ankle exoskeletons using a standard practice protocol and two innovative protocols that use an instantaneous cost mapping analysis. All cost landscapes were a function of the devices' actuation timing. Results showed that for this device a protocol using an instantaneous cost mapping analysis could accurately identify optimal parameter configurations in 20 min, where the standard practice protocol required 42 min. Additionally, using an instantaneous cost mapping analysis with the standard practice's parameter exploration significantly improved fit confidence. These methods could greatly improve real-time optimization of robotic assistive devices or studies focused on biomechanical manipulations of locomotion. We are presenting novel subject-specific metabolic cost landscape confidence analyses. These confidence analyses can greatly improve experimental design, intersubject
Describing and compensating gas transport dynamics for accurate instantaneous emission measurement
Weilenmann, Martin; Soltic, Patrik; Ajtay, Delia
Instantaneous emission measurements on chassis dynamometers and engine test benches are becoming increasingly usual for car-makers and for environmental emission factor measurement and calculation, since much more information about the formation conditions can be extracted than from the regulated bag measurements (integral values). The common exhaust gas analysers for the "regulated pollutants" (carbon monoxide, total hydrocarbons, nitrogen oxide, carbon dioxide) allow measurement at a rate of one to ten samples per second. This gives the impression of having after-the-catalyst emission information with that chronological precision. It has been shown in recent years, however, that beside the reaction time of the analysers, the dynamics of gas transport in both the exhaust system of the car and the measurement system last significantly longer than 1 s. This paper focuses on the compensation of all these dynamics convoluting the emission signals. Most analysers show linear and time-invariant reaction dynamics. Transport dynamics can basically be split into two phenomena: a pure time delay accounting for the transport of the gas downstream and a dynamic signal deformation since the gas is mixed by turbulence along the way. This causes emission peaks to occur which are smaller in height and longer in time at the sensors than they are after the catalyst. These dynamics can be modelled using differential equations. Both mixing dynamics and time delay are constant for modelling a raw gas analyser system, since the flow in that system is constant. In the exhaust system of the car, however, the parameters depend on the exhaust volume flow. For gasoline cars, the variation in overall transport time may be more than 6 s. It is shown in this paper how all these processes can be described by invertible mathematical models with the focus on the more complex case of the car's exhaust system. Inversion means that the sharp emission signal at the catalyst out location can be
Palanivel, M.; Priyan, S.; Mala, P.
2017-11-01
In the current global market, organizations use many promotional tools to increase their sales. One such tool is sales teams' initiatives or promotional policies, i.e., free gifts, discounts, packaging, etc. This phenomenon motivates the retailer/or buyer to order a large inventory lot so as to take full benefit of promotional policies. In view of this the present paper considers a two-warehouse (owned and rented) inventory problem for a non-instantaneous deteriorating item with inflation and time value of money over a finite planning horizon. Here, demand depends on the sales team's initiatives and shortages are partially backlogged at a rate dependent on the duration of waiting time up to the arrival of next lot. We design an algorithm to obtain the optimal replenishment strategies. Numerical analysis is also given to show the applicability of the proposed model in real-world two-warehouse inventory problems.
VANSTEENIS, HG; TULEN, JHM; MULDER, LJM
This paper compares two methods to estimate heart rate variability spectra i.e., the spectrum of counts and the instantaneous heart rate spectrum. Contrary to Fourier techniques based on equidistant sampling of the interbeat intervals, the spectrum of counts of the instantaneous heart rate spectrum
Project of computer program for designing the steel with the assumed CCT diagram
S. Malara; J. Trzaska; L.A. Dobrzański
2007-01-01
Purpose: The aim of this paper was developing a project of computer aided method for designing the chemicalcomposition of steel with the assumed CCT diagram.Design/methodology/approach: The purpose has been achieved in four stages. At the first stage characteristicpoints of CCT diagram have been determined. At the second stage neural networks have been developed, andnext CCT diagram terms of similarity have been worked out- at the third one. In the last one steel chemicalcomposition optimizat...
Yerramsetti, Ashok; Marchette, Steven A; Shelton, Amy L
2013-07-01
Orientation dependence in spatial memory has often been interpreted in terms of accessibility: Object locations are encoded relative to a reference orientation that affords the most accurate access to spatial memory. An open question, however, is whether people naturally use this "preferred" orientation whenever recalling the space. We tested this question by asking participants to locate buildings on a familiar campus from various imagined locations, without specifying the heading to be assumed. We then used these pointing judgments to infer the approximate heading participants assumed at each location. Surprisingly, each location showed a unique assumed heading that was consistent across participants and seemed to reflect episodic or visual properties of the space. This result suggests that although locations are encoded relative to a reference orientation, other factors may influence how people choose to access the stored information and whether they appeal to long-term spatial memory or other more sensory-based stores. PsycINFO Database Record (c) 2013 APA, all rights reserved.
The impact of assumed knowledge entry standards on undergraduate mathematics teaching in Australia
King, Deborah; Cattlin, Joann
2015-10-01
Over the last two decades, many Australian universities have relaxed their selection requirements for mathematics-dependent degrees, shifting from hard prerequisites to assumed knowledge standards which provide students with an indication of the prior learning that is expected. This has been regarded by some as a positive move, since students who may be returning to study, or who are changing career paths but do not have particular prerequisite study, now have more flexible pathways. However, there is mounting evidence to indicate that there are also significant negative impacts associated with assumed knowledge approaches, with large numbers of students enrolling in degrees without the stated assumed knowledge. For students, there are negative impacts on pass rates and retention rates and limitations to pathways within particular degrees. For institutions, the necessity to offer additional mathematics subjects at a lower level than normal and more support services for under-prepared students impacts on workloads and resources. In this paper, we discuss early research from the First Year in Maths project, which begins to shed light on the realities of a system that may in fact be too flexible.
A New MPPT Control for Photovoltaic Panels by Instantaneous Maximum Power Point Tracking
Tokushima, Daiki; Uchida, Masato; Kanbei, Satoshi; Ishikawa, Hiroki; Naitoh, Haruo
This paper presents a new maximum power point tracking control for photovoltaic (PV) panels. The control can be categorized into the Perturb and Observe (P & O) method. It utilizes instantaneous voltage ripples at PV panel output terminals caused by the switching of a chopper connected to the panel in order to identify the direction for the maximum power point (MPP). The tracking for the MPP is achieved by a feedback control of the average terminal voltage of the panel. Appropriate use of the instantaneous and the average values of the PV voltage for the separate purposes enables both the quick transient response and the good convergence with almost no ripples simultaneously. The tracking capability is verified experimentally with a 2.8 W PV panel under a controlled experimental setup. A numerical comparison with a conventional P & O confirms that the proposed control extracts much more power from the PV panel.
Zapata, TomáS. R.; Allmendinger, Richard W.
1996-10-01
Analysis of synorogenic deposits preserved near the thrust front zone of the Precordillera fold and thrust belt and in the Bermejo foreland basin in central Argentina documents the evolution of deformation during the last 5 Myr as well as the thrust system kinematics. Seismic lines across the area display examples of progressive and instantaneous limb rotations. The easternmost thrust plate of the Central Precordillera, the Niquivil thrust, experienced episodic motion in two main stages: a first thrust movement as a fault-propagation fold and a second movement as a high-angle anticlinal breakthrough fault after a period of quiescence. Growth strata deposited in the La Pareja intermontane basin and the Las Salinas and Bermejo anticline recorded continuous growth of Eastern Precordilleran structures beginning at ˜2.7 Ma, with uplift rates of ˜0.3 mm/yr for the Niquivil anticline, 1.08 mm/yr for the Las Salinas anticline, and between ˜0.6 and 0.38 mm/yr during the last ˜2 Myr for the Bermejo anticline. Once the Eastern Precordillera began to grow, the propagation of the Niquivil thrust stopped, restricting the deformation to the young Vallecito out-of sequence thrust. The complex geometry of growth strata deposited on the back limb of the Las Salinas anticline can be explained by using a model of a two-step fault propagation fold with constant layer thickness. The Bermejo anticline of the Eastern Precordillera is formed by the simultaneous propagation of a shallow fault, responsible for the fold shape, and a deep fault that produced vertical uplift. A growth triangle that documents instantaneous forelimb rotation for a fault-propagation fold is recorded for the first time in a published seismic line.
Instantaneous mechanical fastening of quasi-isotropic CFRP laminates by a self-piercing rivet
上田, 政人; 三宅, 崇太郎; 長谷川, 寛幸; 平野, 義鎭; Ueda, Masahito; Miyake, Sotaro; Hasegawa, Hiroyuki; Hirano, Yoshiyasu
2012-01-01
A modified self-piercing rivet (SPR) has been proposed to mechanically fasten CFRP laminates. The modified SPR consists of a rivet body and two flat washers. The two flat washers were used to suppress delamination in the CFRP laminates at the point of piercing. The advantages of the modified SPR for fastening CFRP laminates are instantaneous process time and low cost. Any pretreatments such as surface treatments or hole drilling are not required. In this study, the viability of the modified S...
Similarity, agreement, and assumed similarity in proxy end-of-life decision making.
McDade-Montez, Elizabeth; Watson, David; Beer, Andrew
2013-12-01
Medical decisions near the end of life are often made by proxies who can be inaccurate in their judgments of patient preferences. Given that accuracy in surrogate decision making is an important goal in end-of-life decision making, and in light of that previously seen levels of accuracy reflect substantial disagreement, error, or both, this study examined both relationship and individual factors that potentially affect surrogate accuracy. Specifically, this study examined similarity, agreement, and assumed similarity-a process whereby raters use their own traits and preferences to rate another person-in spousal ratings of end-of-life treatment. This study expands on previous research by examining the potential influence of relationship factors and assumed similarity on end-of-life decision making among a sample of newlyweds. Newly married couples (n = 197) completed self and spouse measures of hypothetical end-of-life preferences and scales assessing marital satisfaction, personality, and attitudes. Results indicate a moderate level of similarity on husband and wife self-rated end-of-life treatment preferences (rs = .18-.29) and a moderate level of agreement between self and proxy ratings (rs = .17-.41). The largest correlations were seen between self ratings and proxy ratings (e.g., husband self ratings and husband proxy ratings of wife preferences, rs = .46-.69), reflecting strong assumed similarity in proxy ratings. For wives, similarity with husbands on a few attitudinal variables (i.e., spirituality, moral strictness, and conservatism) influenced proxy accuracy. Recognizing the potential impact of personal preferences on proxy ratings, as well as the potential influence of relationship factors, may help improve proxy accuracy and end-of-life care for patients and families.
VizieR Online Data Catalog: Stellar parameters and assumed wind parameters (Cazorla+, 2017)
Cazorla, C.; Morel, T.; Naze, Y.; Rauw, G.; Semaan, T.; Daflon, S.; Oey, S.
2017-03-01
Stellar parameters derived for the stars in our sample and assumed wind parameters for our hotter stars. Because macroturbulent velocities cannot be determined reliably for fast rotators (Sect. 4.2), all values in column 6 are upper limits. Column 7 provides the multiplicity status (see Sect. 4.1 for the classification criterion and Appendix C for the RV studies of each individual object). The runaway status is based on literature studies (references are given on a star-to-star basis in Appendix C). Columns 15, 16, and 17 of the table presenting the results for the hotter stars list the assumed wind parameters. For stars with the lowest temperatures (typically B0.5 stars), the carbon abundance cannot be firmly determined due to the weakness of the CIII lines at these temperatures. Besides, NII lines may also be very weak for the hottest stars studied with DETAIL/SURFACE. In these cases, we provide upper limits for both carbon and nitrogen abundances. They correspond to predicted lines becoming detectable, i.e., having a depth significantly exceeding the local noise. Similarly, CMFGEN fits may converge towards very high or very low CNO abundances. In both cases, the upper or lower limits were determined from the chi2 curves and correspond to the limit of their flat minimum. Since the CNO abundances are measured relative to the hydrogen content (assumed to be constant in our study), a correction should in principle be applied to the CNO abundances of stars that exhibit a very high helium abundance (and therefore have a reduced hydrogen abundance). However, we found this correction to be negligible (<~0.1dex) even for the most He-rich stars. The 1σ errors on the parameters are given in dedicated columns. (2 data files).
Instantaneous and cumulative influences of competition on impulsive choices in domestic chicks.
Directory of Open Access Journals (Sweden)
Hidetoshi eAmita
2011-09-01
Full Text Available This study examined instantaneous and cumulative effects of competitive interactions on impulsiveness in the inter-temporal choices in domestic chicks. Chicks were trained to peck colored beads to gain delayed food rewards (1 or 6 grains of millet delivered after a delay ranging between 0–4.5 s, and were tested in binary choices between a small-short delay option (SS and a large-long delay alternative (LL. To examine whether competitive foraging instantaneously changes impulsiveness, we intraindividually compared choices between two consecutive tests in different contexts, one with competitors and another without. We found that (1 the number of the choice of LL was not influenced by competition in the tests, but (2 the operant peck latency was shortened by competition, suggesting a socially enhanced incentive for food. To further examine the lasting changes, two groups of chicks were consecutively trained and tested daily for 2 weeks according to a behavioral titration procedure, one with competitors and another without. Inter-group comparisons of the choices revealed that (3 choice impulsiveness gradually decreased along development, while (4 the chicks trained in competition maintained a higher level of impulsiveness. These results suggest that competitive foraging causes impulsive choices not by direct/contextual modification. Causal link between the instantaneous enhancement of incentive and the gradual effects on impulsivity remains to be examined. Some (yet unspecified factors may be indirectly involved.
Instantaneous current and field structure of a gun-driven spheromak for two gun polarities
Woodruff, S.; Nagata, M.
2002-12-01
The instantaneous plasma structure of the SPHEX spheromak is determined here by numerically processing data from insertable Rogowski and magnetic field probes. Data is presented and compared for two modes of gun operation: with the central electrode biased positively and negatively. It is found that while the mean-, or even instantaneous-, field structure would give the impression of a roughly axisymmetric spheromak, the instantaneous current structure does not. Hundred per cent variations in J measured at the magnetic axis can be explained by the rotation of a current filament that has a width equal to half of the radius of the flux-conserving first wall. In positive gun operation, current leaves the filament in the confinement region leading to high wall current there. In negative gun operation, wall current remains low as all injected current returns to the gun through the plasma. The plasma, in either instance, is strongly asymmetric. We discuss evidence for the existence of the current filament in other gun-driven spheromaks and coaxial plasma thrusters.
Use of capacitive sensors with the instantaneous profile method to determine hydraulic conductivity
Directory of Open Access Journals (Sweden)
Eurileny Lucas de Almeida
Full Text Available ABSTRACT Due to the need to monitor soil water tension continuously, the instantaneous profile method is considered laborious, requiring a lot of time, and especially manpower, to set up and maintain. The aim of this work was to evaluate the possibility of using capacitive sensors in place of tensiometers with the instantaneous profile method in an area of the Lower Acaraú Irrigated Perimeter. The experiment was carried out in a Eutrophic Red-Yellow Argisol. The sensors were installed 15, 30, 45 and 60 cm from the surface, and powered by photovoltaic panels, using a power manager to charge the battery and to supply power at night. Records from the capacitive sensors were collected every five minutes and stored on a data acquisition board. With the simultaneous measurement of soil moisture obtained by the sensors, and the total soil water potential from the soil water retention curve, it was possible to determine the hydraulic conductivity as a function of the volumetric water content for each period using the Richards equation. At the end of the experiment, the advantage of using capacitive sensors with the instantaneous profile method was confirmed as an alternative to using a tensiometer. The main advantages of using capacitive sensors were to make the method less laborious and to allow moisture readings at higher tensions in soils of a sandy texture.
Sequential least-square reconstruction of instantaneous pressure field around a body from TR-PIV
Jeon, Young Jin; Gomit, G.; Earl, T.; Chatellier, L.; David, L.
2018-02-01
A procedure is introduced to obtain an instantaneous pressure field around a wing from time-resolved particle image velocimetry (TR-PIV) and particle image accelerometry (PIA). The instantaneous fields of velocity and material acceleration are provided by the recently introduced multi-frame PIV method, fluid trajectory evaluation based on ensemble-averaged cross-correlation (FTEE). The integration domain is divided into several subdomains in accordance with the local reliability. The near-edge and near-body regions are determined based on the recorded image of the wing. The instantaneous wake region is assigned by a combination of a self-defined criterion and binary morphological processes. The pressure is reconstructed from a minimization process of the difference between measured and reconstructed pressure gradients in a least-square sense. This is solved sequentially according to a decreasing order of reliability of each subdomain to prevent a propagation of error from the less reliable near-body region to the free-stream. The present procedure is numerically assessed by synthetically generated 2D particle images based on a numerical simulation. Volumetric pressure fields are then evaluated from tomographic TR-PIV of a flow around a 30-degree-inclined NACA0015 airfoil. A possibility of using a different scheme to evaluate material acceleration for a specific subdomain is presented. Moreover, this 3D application allows the investigation of the effect of the third component of the pressure gradient by which the wake region seems to be affected.
Chulya, Abhisak; Mullen, Robert L.
1989-01-01
A linear finite strip plate element based on Mindlin-Reissner plate theory is developed. The analysis is suitable for both thin and thick plates. In the formulation, new transverse shear strains are introduced and assumed constant in each two-node linear strip. The element stiffness matrix is explicitly formulated for efficient computation and computer implementation. Numerical results showing the efficiency and predictive capability of the element for the analysis of plates are presented for different support and loading conditions and a wide range of thicknesses. No sign of shear locking is observed with the newly developed element.
Improved finite strip Mindlin plate bending element using assumed shear strain distributions
Chulya, Abhisak; Thompson, Robert L.
1988-01-01
A linear finite strip plate element based on Mindlin/Reissner plate theory is developed. The analysis is suitable for both thin and thick plates. In the formulation new transverse shear strains are introduced and assumed constant in each two-code linear strip. The element stiffness matrix is explicitly formulated for efficient computation and computer implementation. Numerical results showing the efficiency and predictive capability of the element for the analysis of plates are presented for different support and loading conditions and a wide range of thicknesses. No sign of shear locking phenomenon was observed with the newly developed element.
Comparison between two-phase and one-phase SLIPI for instantaneous imaging of transient sprays
Mishra, Yogeshwar Nath; Kristensson, Elias; Koegl, Matthias; Jönsson, Joakim; Zigan, Lars; Berrocal, Edouard
2017-09-01
Imaging through optically dense sprays is challenging due to the detection of multiple light scattering, which blurs the recorded images and limits visibility. Structured laser illumination planar imaging (SLIPI) is a technique that is capable of reducing the intensity contribution that stems from multiple scattering in a light sheet imaging configuration. The conventional SLIPI approach is based on recording three modulated sub-images successively, each having a different spatial phase, and has, therefore, been mostly used for temporally averaged imaging. To circumvent this limitation and image spray dynamics, `instantaneous' two-phase (2p) and single-phase (1p) SLIPI approaches have recently been developed. The purpose of the work presented here is to compare these two approaches in terms of optical design, image post-processing routines, multiple scattering suppression ability, and spatial resolution. The two approaches are used to image a transient direct-injection spark-ignition ethanol spray, for both liquid laser-induced fluorescence and Mie scattering detection. The capabilities of the approaches for multiple scattering suppression and image formation have also been numerically modeled by means of Monte Carlo simulation. This article shows that both approaches efficiently suppress the contribution from multiple light scattering, providing images with an intensity profile close to the corresponding single scattering case. Experimentally, this suppression renders both an improvement in image contrast and the removal of undesired stray light components that could be interpreted as signal. However, while 2p-SLIPI preserves most of the initial spatial resolution, 1p-SLIPI results in a loss of spatial resolution, where high-frequency image information is not visible anymore. Thus, there is a trade-off between preserving the most detailed information of the spray structure—with 2p-SLIPI—and being able to record an SLIPI image from a single modulated image
Shonkwiler, K. B.; Ham, J. M.; Williams, C. M.
2013-12-01
Ammonia (NH3) that volatilizes from confined animal feeding operations (CAFOs) can form aerosols that travel long distances where such aerosols can deposit in sensitive regions, potentially causing harm to local ecosystems. However, quantifying the emissions of ammonia from CAFOs through direct measurement is very difficult and costly to perform. A system was therefore developed at Colorado State University for conditionally sampling NH3 concentrations based on weather parameters measured using inexpensive equipment. These systems use passive diffusive cartridges (Radiello, Sigma-Aldrich, St. Louis, MO, USA) that provide time-averaged concentrations representative of a two-week deployment period. The samplers are exposed by a robotic mechanism so they are only deployed when wind is from the direction of the CAFO at 1.4 m/s or greater. These concentration data, along with other weather variables measured during each sampler deployment period, can then be used in a simple inverse model (FIDES, UMR Environnement et Grandes Cultures, Thiverval-Grignon, France) to estimate emissions. There are not yet any direct comparisons of the modeled emissions derived from time-averaged concentration data to modeled emissions from more sophisticated backward Lagrangian stochastic (bLs) techniques that utilize instantaneous measurements of NH3 concentration. In the summer and autumn of 2013, a suite of robotic passive sampler systems were deployed at a 25,000-head cattle feedlot at the same time as an open-path infrared (IR) diode laser (GasFinder2, Boreal Laser Inc., Edmonton, Alberta, Canada) which continuously measured ammonia concentrations instantaneously over a 225-m path. This particular laser is utilized in agricultural settings, and in combination with a bLs model (WindTrax, Thunder Beach Scientific, Inc., Halifax, Nova Scotia, Canada), has become a common method for estimating NH3 emissions from a variety of agricultural and industrial operations. This study will first
Fernández, David Lorente
2015-01-01
This chapter uses a comparative approach to examine the maintenance of Indigenous practices related with Learning by Observing and Pitching In in two generations--parent generation and current child generation--in a Central Mexican Nahua community. In spite of cultural changes and the increase of Western schooling experience, these practices persist, to different degrees, as a Nahua cultural heritage with close historical relations to the key value of cuidado (stewardship). The chapter explores how children learn the value of cuidado in a variety of everyday activities, which include assuming responsibility in many social situations, primarily in cultivating corn, raising and protecting domestic animals, health practices, and participating in family ceremonial life. The chapter focuses on three main points: (1) Cuidado (assuming responsibility for), in the Nahua socio-cultural context, refers to the concepts of protection and "raising" as well as fostering other beings, whether humans, plants, or animals, to reach their potential and fulfill their development. (2) Children learn cuidado by contributing to family endeavors: They develop attention and self-motivation; they are capable of responsible actions; and they are able to transform participation to achieve the status of a competent member of local society. (3) This collaborative participation allows children to continue the cultural tradition and to preserve a Nahua heritage at a deeper level in a community in which Nahuatl language and dress have disappeared, and people do not identify themselves as Indigenous. © 2015 Elsevier Inc. All rights reserved.
An efficient Mindlin finite strip plate element based on assumed strain distribution
Chulya, Abhisak; Thompson, Robert L.
1988-01-01
A simple two node, linear, finite strip plate bending element based on Mindlin-Reissner plate theory for the analysis of very thin to thick bridges, plates, and axisymmetric shells is presented. The new transverse shear strains are assumed for constant distribution in the two node linear strip. The important aspect is the choice of the points that relate the nodal displacements and rotations through the locking transverse shear strains. The element stiffness matrix is explicitly formulated for efficient computation and ease in computer implementation. Numerical results showing the efficiency and predictive capability of the element for analyzing plates with different supports, loading conditions, and a wide range of thicknesses are given. The results show no sign of the shear locking phenomenon.
Compositional Synthesis of Controllers from Scenario-Based Assume-Guarantee Specifications
DEFF Research Database (Denmark)
Greenyer, Joel; Kindler, Ekkart
2013-01-01
to avoid flaws in the product or costly iterations during its development. We propose to use Modal Sequence Diagrams (MSDs), a formal, yet intuitive formalism for specifying the interaction of a system with its environment, and developed a formal synthesis approach that allows us to detect inconsistencies...... and even to automatically synthesize controllers from MSD specifications. The technique is suited for specifications of technical systems with real-time constraints and environment assumptions. However, synthesis is computationally expensive. In order to employ synthesis also for larger specifications, we...... present, in this paper, a novel assume-guarantee-style compositional synthesis technique for MSD specifications. We provide evaluation results underlining the benefit of our approach and formally justify its correctness....
A Study on the Instantaneous Turbulent Flow Field in a 90-Degree Elbow Pipe with Circular Section
Directory of Open Access Journals (Sweden)
Shiming Wang
2016-01-01
Full Text Available Based on the special application of 90-degree elbow pipe in the HTR-PM, the large eddy simulation was selected to calculate the instantaneous flow field in the 90-degree elbow pipe combining with the experimental results. The characteristics of the instantaneous turbulent flow field under the influence of flow separation and secondary flow were studied by analyzing the instantaneous pressure information at specific monitoring points and the instantaneous velocity field on the cross section of the elbow. The pattern and the intensity of the Dean vortex and the small scale eddies change over time and induce the asymmetry of the flow field. The turbulent disturbance upstream and the flow separation near the intrados couple with the vortexes of various scales. Energy is transferred from large scale eddies to small scale eddies and dissipated by the viscous stress in the end.
Li, Bing; Zhang, Xining; Wu, Tingting
2018-03-01
Recently, Instantaneous Angular Speed (IAS) measurement is successfully established and prevalently applied to a wide variety of machines due to the hypothesis that the speed fluctuation of rotating machinery carries plentiful dynamic responses. Nevertheless, exploration and application based on angular signal are still insufficient. Under the same hypothesis, in this paper, we introduced an extended algorithm named Instantaneous Angular Phase Demodulation (IAPD), together with the selection of optimal sideband family to extract the Instantaneous Angular Displacement Fluctuation (IADF) signal. In order to evaluate the performance of IADF signal, an effective approach was demonstrated using IADF signal to address the fault detection and diagnosis issue. After extracting the IADF signal, a much effective method was developed to deal with the large amount of data generated during the signal collection process. Then, we used the well-developed techniques, i.e., empirical mode decomposition (EMD) and envelope analysis, to undertake the signal de-noising and feature extraction task. The effectiveness and capability of the IADF signal were evaluated by two kinds of gearboxes under differentconditions in practice. In particular, the prevalent IAS signal and vibration signal were also involved and testified by the proposed procedure. Experimental results demonstrated that by means of the IADF signal, the combination of EMD and envelope analysis not only provided accurate identification results with a higher signal-to-noise ratio, but was also capable of revealing the fault characteristics significantly and effectively. In contrast, although the IAS signal had the potential ability to diagnose the serious fault, it failed for the slight crack case. Moreover, the same procedure even its improvements, i.e., ensemble empirical mode decomposition and local mean decomposition, all failed to recognize the faults in terms of vibration signals. Copyright © 2018 ISA. Published by
Kristiawan, Magdalena; Sobolik, Vaclav; Al Haddad, Mazen; Allaf, Karim
2008-01-01
The isolation of Indonesian cananga oil was carried out by a new process, instantaneous controlled pressure drop (DIC). Dry cananga flowers (Cananga odorata Hook. fil. et Thomson, forma macrophylla) were exposed for a short time to saturated steam and then the pressure was abruptly decreased to a vacuum level (about 5 kPa). This abrupt pressure drop provokes auto-vaporization of the superheated volatile compounds, expansion and breaking of the cell walls and instantaneous cooling. In this ...
Receive antenna selection for underlay cognitive radio with instantaneous interference constraint
Hanif, Muhammad Fainan
2015-06-01
Receive antenna selection is a low complexity scheme to reap diversity benefits.We analyze the performance of a receive antenna selection scheme in spectrum sharing systems where the antenna that results in highest signal-to-interference plus noise ratio at the secondary receiver is selected to improve the performance of secondary transmission. Exact and asymptotic behaviours of the received SINR are derived for both general and interference limited scenarios over general fading environment. These results are then applied to the outage and average bit error rate analysis when the secondary transmitter changes the transmit power in finite discrete levels to satisfy the instantaneous interference constraint at the primary receiver.
Backstroke swimming: exploring gender differences in passive drag and instantaneous net drag force.
Formosa, Danielle P; Sayers, Mark Gregory Leigh; Burkett, Brendan
2013-12-01
This study explored and quantified gender differences in passive drag and instantaneous net drag force profile for elite backstroke swimmers (FINA points 938 ± 71). Nine female and ten male backstroke swimmers completed eight maximum speed trials. During the passive drag condition participants were towed at the speed achieved within the maximum effort backstroke swimming trials, while holding a supine stationary streamline position. The remaining trials, swimmers performed their natural swimming stroke, while attached to an assisted towing device. Male participant's passive (P backstroke swimming provides further insight into stroke technique of this sport.
The analysis of instantaneous tool displacements during precise ball end milling
Directory of Open Access Journals (Sweden)
Wojciechowski Szymon
2017-01-01
Full Text Available The paper presents the quantitative and qualitative analysis of monolithic ball end mill’s instantaneous displacements generated during precise milling of inclined surfaces. The conducted experiment involves the measurements of tool’s joining part displacements with the application of laser displacement sensor and cutting forces with piezoelectric dynamometer. The milling tests were carried out for the hardened alloy 55NiCrMoV6 steel in a range of variable feed per tooth and surface inclination angle values. The obtained results can be applied for the selection of effective milling parameters allowing the improvement of machined surface finish.
DEFF Research Database (Denmark)
Harrod, Steven; Kelton, W. David
2006-01-01
with piecewise-constant instantaneous rate functions, a capability that has been implemented in commercial simulation software. They test these algorithms in C programs and make comparisons of accuracy, speed, and variability across disparate rate functions and microprocessor architectures. Choice of optimal......Nonstationary Poisson processes are appropriate in many applications, including disease studies, transportation, finance, and social policy. The authors review the risks of ignoring nonstationarity in Poisson processes and demonstrate three algorithms for generation of Poisson processes...... algorithm could not be predicted without knowledge of microprocessor architecture....
Lower vehicular primary emissions of NO2 in Europe than assumed in policy projections
Grange, Stuart K.; Lewis, Alastair C.; Moller, Sarah J.; Carslaw, David C.
2017-12-01
Many European countries do not meet legal air quality standards for ambient nitrogen dioxide (NO2) near roads; a problem that has been forecasted to persist to 2030. Although European air quality standards regulate NO2 concentrations, emissions standards for new vehicles instead set limits for NOx—the combination of nitric oxide (NO) and NO2. From around 1990 onwards, the total emissions of NOx declined significantly in Europe, but roadside concentrations of NO2—a regulated species—declined much less than expected. This discrepancy has been attributed largely to the increasing usage of diesel vehicles in Europe and more directly emitted tailpipe NO2. Here we apply a data-filtering technique to 130 million hourly measurements of NOx, NO2 and ozone (O3) from roadside monitoring stations across 61 urban areas in Europe over the period 1990-2015 to estimate the continent-wide trends of directly emitted NO2. We find that the ratio of NO2 to NOx emissions increased from 1995 to around 2010 but has since stabilized at a level that is substantially lower than is assumed in some key emissions inventories. The proportion of NOx now being emitted directly from road transport as NO2 is up to a factor of two smaller than the estimates used in policy projections. We therefore conclude that there may be a faster attainment of roadside NO2 air quality standards across Europe than is currently expected.
Oseso, Linda; Magaret, Amalia S; Jerome, Keith R; Fox, Julie; Wald, Anna
2016-09-01
Current treatment of genital herpes is focused on ameliorating signs and symptoms but is not curative. However, as potential herpes simplex virus (HSV) cure approaches are tested in the laboratory, we aimed to assess the interest in such studies by persons with genital herpes and the willingness to assume risks associated with experimental therapy. We constructed an anonymous online questionnaire that was posted on websites that provide information regarding genital herpes. The questions collected demographic and clinical information on adults who self-reported as having genital herpes, and assessed attitudes toward and willingness to participate in HSV cure clinical research. Seven hundred eleven participants provided sufficient responses to be included in the analysis. Sixty-six percent were women; the median age was 37 years, and the median time since genital HSV diagnosis was 4.7 years. The willingness to participate in trials increased from 59.0% in phase 1 to 68.5% in phase 2, and 81.2% in phase 3 trials, and 40% reported willingness to participate even in the absence of immediate, personal benefits. The most desirable outcome was the elimination of risk for transmission to sex partner or neonate. The mean perceived severity of receiving a diagnosis of genital HSV-2 was 4.2 on a scale of 1 to 5. Despite suppressive therapy available, persons with genital herpes are interested in participating in clinical research aimed at curing HSV, especially in more advanced stages of development.
Rocca, Jennifer D.; Hall, Edward K.; Lennon, Jay T.; Evans, Sarah E.; Waldrop, Mark P.; Cotner, James B.; Nemergut, Diana R.; Graham, Emily B.; Wallenstein, Matthew D.
2015-01-01
For any enzyme-catalyzed reaction to occur, the corresponding protein-encoding genes and transcripts are necessary prerequisites. Thus, a positive relationship between the abundance of gene or transcripts and corresponding process rates is often assumed. To test this assumption, we conducted a meta-analysis of the relationships between gene and/or transcript abundances and corresponding process rates. We identified 415 studies that quantified the abundance of genes or transcripts for enzymes involved in carbon or nitrogen cycling. However, in only 59 of these manuscripts did the authors report both gene or transcript abundance and rates of the appropriate process. We found that within studies there was a significant but weak positive relationship between gene abundance and the corresponding process. Correlations were not strengthened by accounting for habitat type, differences among genes or reaction products versus reactants, suggesting that other ecological and methodological factors may affect the strength of this relationship. Our findings highlight the need for fundamental research on the factors that control transcription, translation and enzyme function in natural systems to better link genomic and transcriptomic data to ecosystem processes.
Stanke, Monika; Adamowicz, Ludwik
2013-10-03
In this work, we describe how the energies obtained in molecular calculations performed without assuming the Born-Oppenheimer (BO) approximation can be augmented with corrections accounting for the leading relativistic effects. Unlike the conventional BO approach, where these effects only concern the relativistic interactions between the electrons, the non-BO approach also accounts for the relativistic effects due to the nuclei and due to the coupling of the coupled electron-nucleus motion. In the numerical sections, the results obtained with the two approaches are compared. The first comparison concerns the dissociation energies of the two-electron isotopologues of the H2 molecule, H2, HD, D2, T2, and the HeH(+) ion. The comparison shows that, as expected, the differences in the relativistic contributions obtained with the two approaches increase as the nuclei become lighter. The second comparison concerns the relativistic corrections to all 23 pure vibrational states of the HD(+) ion. An interesting charge asymmetry caused by the nonadiabatic electron-nucleus interaction appears in this system, and this effect significantly increases with the vibration excitation. The comparison of the non-BO results with the results obtained with the conventional BO approach, which in the lowest order does not describe the charge-asymmetry effect, reveals how this effect affects the values of the relativistic corrections.
Directory of Open Access Journals (Sweden)
Selami KESLER
2009-01-01
Full Text Available The power flow of the rotor circuit is controlled by different methods in induction machines used for producing high torque in applications involved great power and constant output power with constant frequency in wind turbines. The voltage with slip frequency can be applied on rotor windings to produce controlled high torque and obtain optimal power factor and speed control. In this study, firstly, the dynamic effects of the voltage applying on rotor windings through the rings in slip-ring induction machines are researched and undesirable aspects of the method are exposed with simulations supported by experiments. Afterwards, a fuzzy logic based inverter model on rotor side is proposed with a view to improving the dynamic effects, controlling high torque producing and adjusting machine speed in instantaneous forced conditions. For the simulation model of the system in which the stator side is directly connected to the grid in steady state operation, a C/C++ algorithm is developed and the results obtained for different load conditions are discussed.
An HF and lower VHF spectrum assessment system exploiting instantaneously wideband capture
Barnes, Rod I.; Singh, Malkiat; Earl, Fred
2017-09-01
We report on a spectral environment evaluation and recording (SEER) system, for instantaneously wideband spectral capture and characterization in the HF and lower VHF band, utilizing a direct digital receiver coupled to a data recorder. The system is designed to contend with a wide variety of electromagnetic environments and to provide accurately calibrated spectral characterization and display from very short (ms) to synoptic scales. The system incorporates a novel RF front end involving automated gain and equalization filter selection which provides an analogue frequency-dependent gain characteristic that mitigates the high dynamic range found across the HF and lower VHF spectrum. The system accurately calibrates its own internal noise and automatically subtracts this from low variance, external spectral estimates, further extending the dynamic range over which robust characterization is possible. Laboratory and field experiments demonstrate that the implementation of these concepts has been effective. Sensitivity to varying antenna load impedance of the internal noise reduction process has been examined. Examples of software algorithms to provide extraction and visualization of spectral behavior over narrowband, wideband, short, and synoptic scales are provided. Application in HF noise spectral density monitoring, spectral signal strength assessment, and electromagnetic interference detection is possible with examples provided. The instantaneously full bandwidth collection provides some innovative applications, and this is demonstrated by the collection of discrete lightning emissions, which form fast ionograms called "flashagrams" in power-delay-frequency plots.
Griffin, Peter; Cooper, Clayton; Glick, Joshua; Terndrup, Thomas E
2014-08-01
Several studies have demonstrated subpar chest compression (CC) performance by trained health care professionals. The objective of this study was to determine the immediate and sustained effect of instantaneous audiovisual feedback on CC quality. A prospective, randomized, crossover study measuring the effect of audiovisual feedback training on the performance of CCs by health care providers and medical students in a simulated cardiopulmonary arrest scenario was performed. Compression rate, hand placement, depth, and recoil were collected using 60-second epochs of CC on a simulation mannequin. Data from 200 initial enrollments and 100 tested 1 year later were analyzed by evaluators using standard criterion. At initial testing, feedback trainees demonstrated significantly improved depth compliance, recoil compliance, and accuracy of hand placement. One year later, the previous year's control group now receiving feedback demonstrated immediate improvement in depth, hand placement, and rate. In the feedback group, the only statistically significant improvement from initial baseline to the baseline 1 year later was an 18% improvement in depth compliance. However, the same improvement rate was seen in the control group. Improved depth compliance performance was correlated to the number of cardiopulmonary resuscitation training sessions received external to the study. Instantaneous audiovisual feedback training on CC quality produces immediate improvements in compression rate, hand placement, as well as depth and recoil compliance. These improvements, however, are not retained 1 year later. Improved depth performance may be correlated to an increased training frequency.
Engineering evaluation of alternatives: Managing the assumed leak from single-shell Tank 241-T-101
International Nuclear Information System (INIS)
Brevick, C.H.; Jenkins, C.
1996-02-01
At mid-year 1992, the liquid level gage for Tank 241-T-101 indicated that 6,000 to 9,000 gal had leaked. Because of the liquid level anomaly, Tank 241-T-101 was declared an assumed leaker on October 4, 1992. SSTs liquid level gages have been historically unreliable. False readings can occur because of instrument failures, floating salt cake, and salt encrustation. Gages frequently self-correct and tanks show no indication of leak. Tank levels cannot be visually inspected and verified because of high radiation fields. The gage in Tank 241-T-101 has largely corrected itself since the mid-year 1992 reading. Therefore, doubt exists that a leak has occurred, or that the magnitude of the leak poses any immediate environmental threat. While reluctance exists to use valuable DST space unnecessarily, there is a large safety and economic incentive to prevent or mitigate release of tank liquid waste into the surrounding environment. During the assessment of the significance of the Tank 241-T-101 liquid level gage readings, Washington State Department of Ecology determined that Westinghouse Hanford Company was not in compliance with regulatory requirements, and directed transfer of the Tank 241-T-101 liquid contents into a DST. Meanwhile, DOE directed WHC to examine reasonable alternatives/options for safe interim management of Tank 241-T-101 wastes before taking action. The five alternatives that could be used to manage waste from a leaking SST are: (1) No-Action, (2) In-Tank Stabilization, (3) External Tank Stabilization, (4) Liquid Retrieval, and (5) Total Retrieval. The findings of these examinations are reported in this study
Assuming Regge trajectories in holographic QCD: from OPE to Chiral Perturbation Theory
Cappiello, Luigi; Greynat, David
2015-01-01
The Soft Wall model in holographic QCD has Regge trajectories but wrong operator product expansion (OPE) for the two-point vectorial QCD Green function. We correct analytically this problem and describe the axial sector and chiral symmetry breaking. The low energy chiral parameters, $F_{\\pi}$ and $L_{10}$ , are well described analytically by the model in terms of Regge spacing and QCD condensates. The model nicely supports and extends previous theoretical analyses advocating Digamma function to study QCD two-point functions in different momentum regions.
Directory of Open Access Journals (Sweden)
Meyer Karin
2001-11-01
Full Text Available Abstract A random regression model for the analysis of "repeated" records in animal breeding is described which combines a random regression approach for additive genetic and other random effects with the assumption of a parametric correlation structure for within animal covariances. Both stationary and non-stationary correlation models involving a small number of parameters are considered. Heterogeneity in within animal variances is modelled through polynomial variance functions. Estimation of parameters describing the dispersion structure of such model by restricted maximum likelihood via an "average information" algorithm is outlined. An application to mature weight records of beef cow is given, and results are contrasted to those from analyses fitting sets of random regression coefficients for permanent environmental effects.
Energy Technology Data Exchange (ETDEWEB)
Tonnsen, R.R.; Miskimins, J.L. [Colorado School of Mines, Golden, CO (United States)
2010-07-01
This paper presented an alternative view of deep coalbed methane (CBM) permeability, questioning the assumption of using constant pore volume compressibility for modelling permeability changes that would be part of deep CBM production. The sensitivity of coal permeability to changes in stress has led to the assumption that deep coals have limited permeability, but this belief takes for granted that a coal's porosity/cleat system maintains a constant pore volume compressibility during changing stress conditions. Exponentially declining (variable) pore volume compressibility was employed to model changes in permeability related to changing stress conditions within the coalbed. The assumption of constant or variable pore volume compressibility affects modelled permeability changes. Deep coals may maintain higher values during production than previously indicated. The modelled compressibility and permeability results were applied to the simulation of deep CBM reservoirs to determine the practical difference the compressibility assumption has on a coal's simulated production. With the assumption of variable pore volume compressibility, the modelled permeability decreases less than previously indicated, resulting in greater production. The simulation results may justify exploration for deeper CBM reservoirs, although economic production rates are shown to be possible only when the coal is modelled with zero water saturation in the cleat system. 21 refs., 4 tabs., 9 figs.
Sun, W.; Loeb, N. G.; Kato, S.
2003-01-01
An algorithm that determines the 670-nm top-of-atmosphere (TOA) albedo of ice clouds over ocean using Polarization and Directionality of the Earth's Reflectance ( POLDER) multidirectional measurements is developed. A plane-parallel layer of ice cloud with various optical thicknesses and light scattering phase functions is assumed. For simplicity, we use a double Henyey-Greenstein phase function to approximate the volume-averaged phase function of the ice clouds. A multidirectional reflectance best-fit match between theoretical and POLDER reflectances is used to infer effective cloud optical thickness, phase function and TOA albedo. Sensitivity tests show that while the method does not provide accurate independent retrievals of effective cloud optical depth and phase function, TOA albedo retrievals are accurate to within similar to 3% for both a single layer of ice clouds or a multilayer system of ice clouds and water clouds. When the method is applied to POLDER measurements and retrieved albedos are compared with albedos based on empirical angular distribution models (ADMs), zonal albedo differences are generally smaller than similar to 3%. When albedos are compared with those on the POLDER-I ERB and Cloud product, the differences can reach similar to 15% at small solar zenith angles.
Assuming Regge trajectories in holographic QCD: from OPE to chiral perturbation theory
Energy Technology Data Exchange (ETDEWEB)
Cappiello, Luigi; Greynat, David [Universita di Napoli ' ' Federico II' ' , Dipartimento di Fisica, Naples (Italy); INFN-Sezione di Napoli, Naples (Italy); D' Ambrosio, Giancarlo [INFN-Sezione di Napoli, Naples (Italy); CERN Theory Division, Geneva 23 (Switzerland)
2015-10-15
The soft wall model in holographic QCD has Regge trajectories but wrong operator product expansion (OPE) for the two-point vectorial QCD Green function. We modify the dilaton potential to comply with the OPE. We study also the axial two-point function using the same modified dilaton field and an additional scalar field to address chiral symmetry breaking. OPE is recovered adding a boundary term and low energy chiral parameters, F{sub π} and L{sub 10}, are well described analytically by the model in terms of Regge spacing and QCD condensates. The model nicely supports and extends previous theoretical analyses advocating Digamma function to study QCD two-point functions in different momentum regions. (orig.)
Assuming Regge trajectories in holographic QCD: from OPE to Chiral Perturbation Theory
Cappiello, Luigi; Greynat, David
2015-01-01
The soft wall model in holographic QCD has Regge trajectories but wrong operator product expansion (OPE) for the two-point vectorial QCD Green function. We modify the dilaton potential to comply OPE. We study also the axial two-point function using the same modified dilaton field and an additional scalar field to address chiral symmetry breaking. OPE is recovered adding a boundary term and low energy chiral parameters, $F_\\pi$ and $L_{10}$, are well described analytically by the model in terms of Regge spacing and QCD condensates. The model nicely supports and extends previous theoretical analyses advocating Digamma function to study QCD two-point functions in different momentum regions.
Villegas, Arturo; Diez, Francisco J.
2013-11-01
Time-resolved measurements of instantaneous pressure fields and aerodynamic loads are obtained for rotating airfoils. These allowed evaluating temporal variations in the flow field and were able to capture the evolution of vortex shedding in the wake of the rotating blade. The results show the influence of vortex shedding in the instantaneous loads. These measurements involve obtaining first the velocity field from TR-PIV. This is used to calculate the pressure field from the Poisson pressure equation, and later the forces from the integral momentum equation. The robustness of the measurements is analyzed by calculating the PIV uncertainty, and the independence of the calculated forces. Experimental mean aerodynamic forces are compared to theoretical predictions from the Blade Element Momentum theory (BEM) showing good agreement. The instantaneous pressure varied with time only in the wake due to vortex shedding. This is the first time the evolution of the instantaneous pressure field has been resolved for a rotating airfoil. The contribution to the instantaneous forces from each term in the integral momentum equation is evaluated. The analysis shows that the larger contributions to the normal force coefficient are from the unsteady and the pressure terms while the larger contribution to the tangential force coefficient is from the convective term. The method can be used to measure unsteady forces in rotating airfoils, providing useful information not just for computational studies, but also for aerodynamics, material and structural optimization and safety purposes.
Design-based Sample and Probability Law-Assumed Sample: Their Role in Scientific Investigation.
Ojeda, Mario Miguel; Sahai, Hardeo
2002-01-01
Discusses some key statistical concepts in probabilistic and non-probabilistic sampling to provide an overview for understanding the inference process. Suggests a statistical model constituting the basis of statistical inference and provides a brief review of the finite population descriptive inference and a quota sampling inferential theory.…
Toothbrush probe for instantaneous measurement of radial profile in tokamak boundary plasma
Energy Technology Data Exchange (ETDEWEB)
Uehara, Kazuya; Sengoku, Seio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Amemiya, Hiroshi
1997-04-01
A new probe for the instantaneous measurement of radial profiles of the boundary scrape-off layer (SOL) plasma has been developed in a tokamak. Five asymmetric double-probe chips are aligned in parallel to a strong magnetic field in the boundary plasma in a tokamak. This probe is named the `toothbrush probe` and can measure the ion temperature as well as the electron temperature and the plasma density in the SOL plasma within only one tokamak plasma shot. First, only one asymmetric probe is mounted on the divertor plate and it is tried to determine the ion temperature. Then, a manufactured toothbrush probe is mounted in the SOL plasma and the radial plasma profiles are simultaneously obtained. Data on the e-folding length of the plasma profile obtained by the toothbrush probe can determine the information on the transport properties such as the diffusion coefficient and the thermal conductivity of electrons and ions. (author)
Transmit Antenna Selection for Underlay Cognitive Radio with Instantaneous Interference Constraint
Hanif, Muhammad
2016-03-28
Cognitive radio (CR) technology addresses the problem of spectrum under-utilization. In underlay CR mode, the secondary users are allowed to communicate provided that their transmission is not detrimental to primary user communication. Transmit antenna selection is one of the low-complexity methods to increase the capacity of wireless communication systems. In this article, we propose and analyze the performance benefit of a transmit antenna selection scheme for underlay secondary system that ensures the instantaneous interference caused by the secondary transmitter to the primary receiver is below a predetermined level. Closed-form expressions of the secondary link outage probability, higher order amount of fading, and ergodic capacity are derived for the proposed scheme. Monte-carlo simulations are also carried out to confirm various mathematical results presented in this article.
Sediment suspension in oscillatory flow: measurements of instantaneous concentration at high shear
DEFF Research Database (Denmark)
Staub, Carsten; Jonsson, Ivar G; Svendsen, Ib A.
1996-01-01
Different syphon type suspended load probes were used together with a specially developed ''carousel'' sampler for measurements of the instantaneous sediment concentration in turbulent oscillatory flow over a sand bed, Shields parameters were well above the ripple/flat bed transition region......, resulting in intense sediment transport over a flat bed, The measurements were performed at different levels in a large oscillating water tunnel. They showed some characteristic features of the temporal concentration variation at fixed levels, including a pronounced effect of the orientation of the suction...... concentration are also presented. The analysis is partly based on Wilson's finding that in sheet flow the equivalent bed roughness is nearly proportional with the Shields parameter, resulting in a roughness/grain diameter ratio much larger than 2.5, the figure often adopted for a flat bed, but without sheet...
Instantaneous, phase-averaged, and time-averaged pressure from particle image velocimetry
de Kat, Roeland
2015-11-01
Recent work on pressure determination using velocity data from particle image velocimetry (PIV) resulted in approaches that allow for instantaneous and volumetric pressure determination. However, applying these approaches is not always feasible (e.g. due to resolution, access, or other constraints) or desired. In those cases pressure determination approaches using phase-averaged or time-averaged velocity provide an alternative. To assess the performance of these different pressure determination approaches against one another, they are applied to a single data set and their results are compared with each other and with surface pressure measurements. For this assessment, the data set of a flow around a square cylinder (de Kat & van Oudheusden, 2012, Exp. Fluids 52:1089-1106) is used. RdK is supported by a Leverhulme Trust Early Career Fellowship.
Audio analysis of statistically instantaneous signals with mixed Gaussian probability distributions
Naik, Ganesh R.; Wang, Wenwu
2012-10-01
In this article, a novel method is proposed to measure the separation qualities of statistically instantaneous audio signals with mixed Gaussian probability distributions. This study evaluates the impact of the Probability Distribution Function (PDF) of the mixed signals on the outcomes of both sub- and super-Gaussian distributions. Different Gaussian measures are evaluated by using various spectral-distortion measures. It aims to compare the different audio mixtures from both super-Gaussian and sub-Gaussian perspectives. Extensive computer simulation confirms that the separated sources always have super-Gaussian characteristics irrespective of the PDF of the signals or mixtures. The result based on the objective measures demonstrates the effectiveness of source separation in improving the quality of the separated audio sources.
Instantaneous Purified Orbit: A New Tool for Analysis of Nonstationary Vibration of Rotor System
Directory of Open Access Journals (Sweden)
Shi Dongfeng
2001-01-01
Full Text Available In some circumstances, vibration signals of large rotating machinery possess time-varying characteristics to some extent. Traditional diagnosis methods, such as FFT spectrum and orbit diagram, are confronted with a huge challenge to deal with this problem. This work aims at studying the four intrinsic drawbacks of conventional vibration signal processing method and instantaneous purified orbit (IPO on the basis of improved Fourier spectrum (IFS to analyze nonstationary vibration. On account of integration, the benefits of short period Fourier transform (SPFT and regular holospectrum, this method can intuitively reflect vibration characteristics of’a rotor system by means of parameter analysis for corresponding frequency ellipses. Practical examples, such as transient vibration in run-up stages and bistable condition of rotor show that IPO is a powerful tool for diagnosis and analysis of the vibration behavior of rotor systems.
Instantaneous band gap collapse in VO{sub 2} caused by photocarrier doping
Energy Technology Data Exchange (ETDEWEB)
Herzog, Marc; Wegkamp, Daniel; Wolf, Martin; Staehler, Julia [Fritz-Haber-Institut der MPG, Berlin (Germany); Xian, Lede; Cudazzo, Pierluigi [Univ. del Pais Vasco, San Sebastian (Spain); European Theoretical Spectroscopy Facility (ETSF) (France); Gatti, Matteo [European Theoretical Spectroscopy Facility (ETSF) (France); Ecole Polytechnique, Palaiseau (France); McGahan, Christina L.; Marvel, Robert E.; Haglund, Richard F. [Vanderbilt Univ., Nashville, Tennessee (United States); Rubio, Angel [Fritz-Haber-Institut der MPG, Berlin (Germany); Univ. del Pais Vasco, San Sebastian (Spain); European Theoretical Spectroscopy Facility (ETSF) (France); MPI for the Structure and Dynamics of Matter, Hamburg (Germany)
2015-07-01
We have investigated the controversially discussed mechanism of the insulator-to-metal transition (IMT) in VO{sub 2} by means of femtosecond time-resolved photoelectron spectroscopy (trPES). Our data show that photoexcitation transforms insulating monoclinic VO{sub 2} quasi-instantaneously into a metal without an 80 fs structural bottleneck for the photoinduced electronic phase transition. First-principles many-body perturbation theory calculations reveal an ultrahigh sensitivity of the VO{sub 2} band gap to variations of the dynamically screened Coulomb interaction thus supporting the fully electronically driven isostructural IMT indicated by our trPES results. We conclude that the ultrafast band structure renormalization is caused by photoexcitation of carriers from localized V 3d valence states, strongly changing the screening before significant hot-carrier relaxation or ionic motion has occurred.
Measurement of instantaneous rotational speed using double-sine-varying-density fringe pattern
Zhong, Jianfeng; Zhong, Shuncong; Zhang, Qiukun; Peng, Zhike
2018-03-01
Fast and accurate rotational speed measurement is required both for condition monitoring and faults diagnose of rotating machineries. A vision- and fringe pattern-based rotational speed measurement system was proposed to measure the instantaneous rotational speed (IRS) with high accuracy and reliability. A special double-sine-varying-density fringe pattern (DSVD-FP) was designed and pasted around the shaft surface completely and worked as primary angular sensor. The rotational angle could be correctly obtained from the left and right fringe period densities (FPDs) of the DSVD-FP image sequence recorded by a high-speed camera. The instantaneous angular speed (IAS) between two adjacent frames could be calculated from the real-time rotational angle curves, thus, the IRS also could be obtained accurately and efficiently. Both the measurement principle and system design of the novel method have been presented. The influence factors on the sensing characteristics and measurement accuracy of the novel system, including the spectral centrobaric correction method (SCCM) on the FPD calculation, the noise sources introduce by the image sensor, the exposure time and the vibration of the shaft, were investigated through simulations and experiments. The sampling rate of the high speed camera could be up to 5000 Hz, thus, the measurement becomes very fast and the change in rotational speed was sensed within 0.2 ms. The experimental results for different IRS measurements and characterization of the response property of a servo motor demonstrated the high accuracy and fast measurement of the proposed technique, making it attractive for condition monitoring and faults diagnosis of rotating machineries.
Assume-Guarantee Verification of Software Components in SOFA 2 Framework
Czech Academy of Sciences Publication Activity Database
Parízek, P.; Plášil, František
2010-01-01
Roč. 4, č. 3 (2010), s. 210-221 ISSN 1751-8806 R&D Projects: GA AV ČR 1ET400300504 Grant - others:GA MŠk(CZ) 7E08004 Institutional research plan: CEZ:AV0Z10300504 Keywords : components * software verification * model checking Subject RIV: JC - Computer Hardware ; Software Impact factor: 0.671, year: 2010
International Nuclear Information System (INIS)
Nomura, Yasushi; Okuno, Hiroshi; Miyoshi, Yoshinori
2004-03-01
Firstly, concerning the methods to set burnup for depletion calculation linked with criticality safety evaluation taking burnup credit into consideration, the upper 50 cm averaged burnups approved by regulations in European countries and USA are comparatively evaluated. Secondary, errors produced by different shapes of axial spent fuel burnup distribution assumed for criticality calculation, bias errors associated with depletion calculation compensated by correction factors applied to calculated nuclide isotopic composition, and statistic errors exerted by variation of irradiation history parameters used as input data for depletion calculation, are separately evaluated by performing criticality analyses with the spent fuel transport cask model of OECD/NEA Burnup Credit Criticality Benchmark. As a result, methods are proposed to set equivalent burnups reduced from a given burnup so as to compensate these errors to obtain criticality calculation results on the conservative side. Finally, 'Equivalent Uniform Burnup' and Equivalent Initial Enrichment' which are derived by incorporating these errors synthetically, are described to mention possibility of their common usage irrespective of difference in spent fuel transport cask specification. (author)
Factor screening in a 12 Run Plackett-Burman design assuming four active factors
Jin, Yingzi
2016-01-01
In this thesis we perform factor screening in a non-regular two-level design by reducing the number of possible sets of active factors to a certain number. The 12 Run Plackett-Burman(PB) design with four active factors is mainly concerned. Our proposed method works through picking up the 6 effects with the highest absolute value out of 10 in each projection model. To evaluate this method, we used the same example as was used in Tyssedal and Shahrukh\\cite{tyssedal2016factor} where variable sel...
International Nuclear Information System (INIS)
Miller, C.W.; Hoffman, F.O.; Shaeffer, D.L.
1978-01-01
In environmental radiological assessments, the depletion of airborne plumes by dry deposition processes and the subsequent contamination of ground and vegetation have been estimated through the use of a parameter termed the 'deposition velocity'. The sensitivity of environmental assessment models to changes in values of deposition velocity is here examined so that the effect of potential variations of deposition velocity on calculations of radiation dose can be determined. The results show that until more data are available great care must be exercised when applying theoretical ideas and scientific judgement in the selection of a value of the deposition velocity to be used in calculating the dose to man as a result of deposition. (U.K.)
LMFBR Emergency Deployment Assuming 45 year Time-Delay Excess CO{sub 2} Removal
Energy Technology Data Exchange (ETDEWEB)
Schenewerk, William Ernest [5060 San Rafael Avenue, Los Angeles, CA, 90042-3239 (United States)
2008-07-01
Atmospheric CO{sub 2} is presently increasing 2.25% per year in proportion to 2.25% per year exponential fossil fuel consumption increase. CO{sub 2} removal is modeled as being proportional to 45-year-earlier CO{sub 2} amount above 280 ppmV-C. This is: Exp (-0.0225/year * 45 years) = 0.36 fraction CO{sub 2} removed from anthropological emissions, apparently by seawater. LMFBRs use 15 year doubling time. Deploying 30000 GWe atomic power by year-2080 results in CO{sub 2} doubling year-2065 if World primary energy consumption continues increasing 2.25% per year. CO{sub 2} remains roughly twice pre-industrial until year-2100. Beginning year-2080, CO{sub 2} declines at 2.25% per year. CO{sub 2} will presumably decline back to roughly the year-2000 value by year-2200 if the 45-year-delay sink remains effective. LMFBR and GCFR fleet expands to 30000 GWe by 2080. 1000 GWe LWR fleet consumes 5 Mt HM (Heavy Metal). Breeder first cores require 1 Mt HM. (author)
Historical Carbon Dioxide Emissions Caused by Land-Use Changes are Possibly Larger than Assumed
Arneth, A.; Sitch, S.; Pongratz, J.; Stocker, B. D.; Ciais, P.; Poulter, B.; Bayer, A. D.; Bondeau, A.; Calle, L.; Chini, L. P.;
2017-01-01
The terrestrial biosphere absorbs about 20% of fossil-fuel CO2 emissions. The overall magnitude of this sink is constrained by the difference between emissions, the rate of increase in atmospheric CO2 concentrations, and the ocean sink. However, the land sink is actually composed of two largely counteracting fluxes that are poorly quantified: fluxes from land-use change andCO2 uptake by terrestrial ecosystems. Dynamic global vegetation model simulations suggest that CO2 emissions from land-use change have been substantially underestimated because processes such as tree harvesting and land clearing from shifting cultivation have not been considered. As the overall terrestrial sink is constrained, a larger net flux as a result of land-use change implies that terrestrial uptake of CO2 is also larger, and that terrestrial ecosystems might have greater potential to sequester carbon in the future. Consequently, reforestation projects and efforts to avoid further deforestation could represent important mitigation pathways, with co-benefits for biodiversity. It is unclear whether a larger land carbon sink can be reconciled with our current understanding of terrestrial carbon cycling. Our possible underestimation of the historical residual terrestrial carbon sink adds further uncertainty to our capacity to predict the future of terrestrial carbon uptake and losses.
Physico-statistical approach to assess the core damage variability due to a total instantaneous blockage of SFR fuel sub-assembly
Energy Technology Data Exchange (ETDEWEB)
Marie, N., E-mail: nathalie.marie@cea.fr [CEA, DEN, DER, Saint Paul Lez Durance, F-13108 (France); Marrel, A. [CEA, DEN, DER, Saint Paul Lez Durance, F-13108 (France); Seiler, J.M. [CEA, DEN, DTN, Grenoble, F-38054 (France); Bertrand, F. [CEA, DEN, DER, Saint Paul Lez Durance, F-13108 (France)
2016-02-15
Highlights: • Physico-statistical tool for SFR safety for Total Instantaneous Blockage accident. • 0D/1D but realistic physical models to describe the phenomenological event tree. • Twenty-seven uncertain parameters identified to cover all realistic accidental transients. • Uncertainty propagation performed via a Monte-Carlo sampling. • Quantification of safety margins: 18.1% of cases above the safety criterion. - Abstract: Within the framework of the generation IV Sodium Fast Reactors (SFR) R&D program of CEA (French commissariat à l’énergie atomique et aux énergies alternatives), the safety in case of accidents is assessed. These accidental scenarios involve very complex transient phenomena. To get round the difficulty of modelling them, only ‘Bounding’ (most damaging) accidental conditions have been up to now studied for the safety demonstration. These transients are simulated with very complex multi-physical codes (such as SIMMER) which nevertheless include some adjusted and not well known parameters and require a long CPU (process) time preventing their direct use for uncertainty propagation and sensitivity studies, especially in case of a high number of uncertain input parameters. To cope with these constraints, a new physico-statistical approach is followed in parallel by the CEA. This approach involves the fast-running description of extended accident sequences coupling analytical models for the main physical phenomena in combination with advanced statistical analysis techniques. The efficiency of the methodology for the reactor safety analysis is demonstrated here for one type of accident – the Total Instantaneous Blockage (TIB) – which involves an extended range of complex physical phenomena. From the establishment of the physical models describing the TIB phenomenology, 27 uncertain input parameters and their associated probability distributions are identified. A propagation of these input parameter uncertainties is performed via a
Continuous modeling of internal-energy transfers in rarefied-gas flows
Choquet, I.; Marmignon, C.
A relationship between the mean probability and the instantaneous probability for energy transfer on the molecular scale in rarefied-gas flows is obtained, assuming that the effective collision cross section depends only on the relative velocity. A method for the exact solution of this equation is introduced which leads to Boyd's expressions for rotational-translation transfer and which extends the validity domain of the vibration-translation model. The results obtained demonstrate that it is necessary to take into account the internal-energy dependence of the effective collision cross section if a suitable equilibrium temperature is to be obtained.
DEFF Research Database (Denmark)
Hubalek, Friedrich; Posedel, Petra
expressions for the asymptotic covariance matrix. We develop in detail the martingale estimating function approach for a bivariate model, that is not a diffusion, but admits jumps. We do not use ergodicity arguments. We assume that both, logarithmic returns and instantaneous variance are observed...... on a discrete grid of fixed width, and the observation horizon tends to infinity. This anaysis is a starting point and benchmark for further developments concerning optimal martingale estimating functions, and for theoretical and empirical investigations, that replace the (actually unobserved) variance process...
Jiang, Weimin
An instantaneous secondary organic aerosol yield (IAY) is a different quantity than an overall aerosol yield (OAY), both qualitatively and quantitatively. Starting from Odum's OAY equation, this paper derives and presents a new equation for the calculation of IAY values. As examples, the two-product form of the equation is applied to 10 representative aromatic and biogenic reactive organic gas (ROG) experiments in the literature. Values of IAY and OAY corresponding to wide ranges of organic aerosol mass concentrations ( M0) are calculated using the new IAY equation in this paper and the original Odum's OAY equation. These IAY and OAY values are shown through aerosol yield curves, which are the plots of IAY or OAY versus M0. Comparative analysis of the IAY and OAY curves shows that both IAY and OAY increase monotonically with M0 and they approach a common maximum value when M0 becomes very high. However, when M0 approaches zero, OAY also approaches zero but IAY approaches a fixed positive value for a given ROG. At any given M0 value, the value of IAY is always higher than that of OAY. The relative differences between IAY and OAY are especially significant under typical ambient and experimental M0 levels. IAY values can be orders of magnitude higher than OAY values and are much better representations of aerosol yields under these M0 levels. When it is used for secondary organic aerosols (SOA) estimation and modelling, the new IAY equation will significantly improve the underestimation of SOA formation caused by directly using the original OAY equation. More sophisticated SOA algorithms could also be developed based on the IAY equation presented here.
DEFF Research Database (Denmark)
Wubs, Martijn
2010-01-01
Qubits driven by resonant strong pulses are studied and a parameter regime is explored in which the dynamics can be solved in closed form. Instantaneous coherent destruction of tunneling can be seen for longer pulses, whereas shorter pulses allow a fast preparation of the qubit state. Results...... are compared with recent experiments of pulsed nitrogen-vacancy center spin qubits in diamond....
Czech Academy of Sciences Publication Activity Database
Kristiawan, M.; Sobolík, Václav; Al-Haddad, M.; Allaf, K.
2008-01-01
Roč. 47, 1 (2008) , s. 66-75 ISSN 0255-2701 Institutional research plan: CEZ:AV0Z40720504 Keywords : cananga oil * essential oil isolation * instantaneous controlled pressure drop (DIC) Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.518, year: 2008
Czech Academy of Sciences Publication Activity Database
Kristiawan, M.; Sobolík, Václav; Al Haddad, M.; Allaf, K.
2007-01-01
Roč. 40, 11 (2007) , s. 1021-1029 ISSN 0021-9592. [IWPI2006. Kobe, 15.10.2006-18.10.2006] Institutional research plan: CEZ:AV0Z40720504 Keywords : cananga oil * instantaneous controlled pressure Drop * steam distillation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.594, year: 2007
A mathematical model of a fishery with variable market price: sustainable fishery/over-exploitation.
Mansal, Fulgence; Nguyen-Huu, Tri; Auger, Pierre; Balde, Moussa
2014-09-01
We present a mathematical bioeconomic model of a fishery with a variable price. The model describes the time evolution of the resource, the fishing effort and the price which is assumed to vary with respect to supply and demand. The supply is the instantaneous catch while the demand function is assumed to be a monotone decreasing function of price. We show that a generic market price equation (MPE) can be derived and has to be solved to calculate non trivial equilibria of the model. This MPE can have 1, 2 or 3 equilibria. We perform the analysis of local and global stability of equilibria. The MPE is extended to two cases: an age-structured fish population and a fishery with storage of the resource.
Quantifying stream nutrient uptake from ambient to saturation with instantaneous tracer additions
Covino, T. P.; McGlynn, B. L.; McNamara, R.
2009-12-01
Stream nutrient tracer additions and spiraling metrics are frequently used to quantify stream ecosystem behavior. However, standard approaches limit our understanding of aquatic biogeochemistry. Specifically, the relationship between in-stream nutrient concentration and stream nutrient spiraling has not been characterized. The standard constant rate (steady-state) approach to stream spiraling parameter estimation, either through elevating nutrient concentration or adding isotopically labeled tracers (e.g. 15N), provides little information regarding the stream kinetic curve that represents the uptake-concentration relationship analogous to the Michaelis-Menten curve. These standard approaches provide single or a few data points and often focus on estimating ambient uptake under the conditions at the time of the experiment. Here we outline and demonstrate a new method using instantaneous nutrient additions and dynamic analyses of breakthrough curve (BTC) data to characterize the full relationship between spiraling metrics and nutrient concentration. We compare the results from these dynamic analyses to BTC-integrated, and standard steady-state approaches. Our results indicate good agreement between these three approaches but we highlight the advantages of our dynamic method. Specifically, our new dynamic method provides a cost-effective and efficient approach to: 1) characterize full concentration-spiraling metric curves; 2) estimate ambient spiraling metrics; 3) estimate Michaelis-Menten parameters maximum uptake (Umax) and the half-saturation constant (Km) from developed uptake-concentration kinetic curves, and; 4) measure dynamic nutrient spiraling in larger rivers where steady-state approaches are impractical.
SciReader enables reading of medical content with instantaneous definitions.
Gradie, Patrick R; Litster, Megan; Thomas, Rinu; Vyas, Jay; Schiller, Martin R
2011-01-25
A major problem patients encounter when reading about health related issues is document interpretation, which limits reading comprehension and therefore negatively impacts health care. Currently, searching for medical definitions from an external source is time consuming, distracting, and negatively impacts reading comprehension and memory of the material. SciReader was built as a Java application with a Flex-based front-end client. The dictionary used by SciReader was built by consolidating data from several sources and generating new definitions with a standardized syntax. The application was evaluated by measuring the percentage of words defined in different documents. A survey was used to test the perceived effect of SciReader on reading time and comprehension. We present SciReader, a web-application that simplifies document interpretation by allowing users to instantaneously view medical, English, and scientific definitions as they read any document. This tool reveals the definitions of any selected word in a small frame at the top of the application. SciReader relies on a dictionary of ~750,000 unique Biomedical and English word definitions. Evaluation of the application shows that it maps ~98% of words in several different types of documents and that most users tested in a survey indicate that the application decreases reading time and increases comprehension. SciReader is a web application useful for reading medical and scientific documents. The program makes jargon-laden content more accessible to patients, educators, health care professionals, and the general public.
Yang, Tingting; Zhong, Yujia; Tao, Dashuai; Li, Xinming; Zang, Xiaobei; Lin, Shuyuan; Jiang, Xin; Li, Zhihong; Zhu, Hongwei
2017-09-01
In nature, some animals change their deceptive coloration for camouflage, temperature preservation or communication. This astonishing function has inspired scientists to replicate the color changing abilities of animals with artificial skin. Recently, some studies have focused on the smart materials and devices with reversible color changing or light-emitting properties for instantaneous strain visualization. However, most of these works only show eye-detectable appearance change when subjected to large mechanical deformation (100%-500% strain), and conspicuous color change at small strain remains rarely explored. In the present study, we developed a user-interactive electronic skin with human-readable optical output by assembling a highly sensitive resistive strain sensor with a stretchable organic electrochromic device (ECD) together. We explored the substrate effect on the electromechanical behavior of graphene and designed a strategy of modulus-gradient structure to employ graphene as both the highly sensitive strain sensing element and the insensitive stretchable electrode of the ECD layer. Subtle strain (0-10%) was enough to evoke an obvious color change, and the RGB value of the color quantified the magnitude of the applied strain. Such high sensitivity to smaller strains (0-10%) with color changing capability will potentially enhance the function of wearable devices, robots and prosthetics in the future.
Khan, MD Shahrukh Adnan; Kuni, Sharsad Kara; Rajkumar, Rajprasad; Syed, Anas; Hawladar, Masum; Rahman, Md. Moshiur
2017-12-01
In this paper, an extensive effort has been made to design and develop a prototype in a laboratory setup environment in order to investigate experimentally the response of a novel Supercapacitor based energy harvesting circuit; particularly the phenomena of instantaneous charging and discharging cycle is analysed. To maximize battery lifespan and storage capacity, charging/discharging cycles need to be optimized in such a way, it ultimately enhances the system performances reliably. Keeping this into focus, an Arduino-MOSFET based control system is developed to charge the Supercapacitor from a low wind Vertical Axis Turbine (VAWT) and discharge it through a 6V battery. With a wind speed of 5m/s, the wind turbine requires approximately 8.1 hours to charge the 6V battery through Supercapacitor bank that constitutes 18 cycles in which each cycle consumes 27 minutes. The overall performance of the proposed system was quite convincing in a sense that the efficiency of the developed Energy Harvesting Circuit EHC raises to 19% in comparison to direct charging of the battery from the Vertical wind turbine. At low wind speed, such value of efficiency margin is quite encouraging which essentially validates the system design.
Instantaneous Pressure Field Calculation from PIV Data with Least-Square Reconstruction
Zhang, Jiacheng; Scalo, Carlo; Vlachos, Pavlos
2016-11-01
A method using least-square reconstruction of instantaneous pressure fields from PIV velocity measurements is introduced and applied to both planar and volumetric flow data. Pressure gradients are computed on a staggered grid from flow acceleration. An overdetermined system of linear equations which relates the pressure and the computed pressure gradients is formulated. The pressure field is estimated as the least-square solution of the overdetermined system. The flow acceleration is approximated by the vortex-in-cell procedure, providing the pressure field from a single velocity snapshot. The least-square method is compared against the omni-directional pressure gradient integration and solving the pressure Poisson equation. The results demonstrate that the omni-directional integration and the least-square method are more robust to the noise in velocity measurements than the pressure Poisson solver. In addition, the computational cost of the least square method is much lower than the omni-directional integration, and very easily extendable to volumetric data retaining computational efficiency. The least-square method maintains higher accuracy than the pressure Poisson equation while retaining a similar computational burden.
Vorticity generation by the instantaneous release of energy near a reflective boundary
Moresco, P.; Harris, T. E.; Jodoin, V.
2014-08-01
The instantaneous release of energy in a localized area of a gas results in the formation of a low-density region and a series of shock and expansion waves. If this process occurs near a boundary, the shock reflections can interact with the density inhomogeneity, leading to the baroclinic generation of vorticity and the subsequent organization of the flow into several structures, including a vortex ring. By means of numerical simulations we illustrate the qualitative changes that occur in the pressure wave patterns and vorticity distribution as the distance from the area of energy release to the boundary is varied. Those changes are shown to be related to the combined effect of the shock waves that, respectively, initially move away and towards the center of the low-density region. In particular, we describe how for small enough offset distances the shocks internal to the inhomogeneity can make a substantial contribution to the vorticity field, influencing the circulation and characteristics of the resulting flow structures.
[Analysis on instantaneous spatial pattern of thermal force field in Harbin].
Zhu, Ning; Wang, Cheng; Zhou, Hongze; Li, Min
2003-11-01
The spatial pattern of urban thermal force field is not only the dominant content in assessing city ecological environment, but also an important base for city green system planning. The status of spatial pattern of thermal force field in Harbin was analyzed with RS and GIS techniques. Based on the instantaneous radiation temperature of the land surfaces in the city when the TM image was sensed remotely, all the patches were divided into 3 levels, i.e., low radiation temperature ( 28 degrees C) were uneven in their areas. The biggest area in these patches was 1489 hm2, and the smallest one was 0.72 hm2. The proportion of the patches with an area less than 1 hm2, between 1-5 hm2, and more than 5 hm2 was 95.02%, 3.46%, and 1.58%, respectively. There were 3 types of spatial patterns of the super-thermal radiation patches, i.e., round form (the average radiation temperature was 30.8 degrees C), ring form (the average radiation temperature was 27 degrees C), and pieces form (the average radiation temperature was 24.7 degrees C). Daowai District and Daoli District were round form, districts along the ring routes of railway in the city were ring form, and Nangang District and Dongli District were pieces form. Some advices to resolve the problem of 'heat island effect' influenced by the factors including greenland covering rate, greenland area and building dimension were discussed.
Arce-Guevara, Valdemar E.; Alba-Cadena, Alfonso; Mendez, Martín O.
Quadrature bandpass filters take a real-valued signal and output an analytic signal from which the instantaneous amplitude and phase can be computed. For this reason, they represent a useful tool to extract time-varying, narrow-band information from electrophysiological signals such as electroencephalogram (EEG) or electrocardiogram. One of the defining characteristics of quadrature filters is its null response to negative frequencies. However, when the frequency band of interest is close to 0 Hz, a careless filter design could let through negative frequencies, producing distortions in the amplitude and phase of the output. In this work, three types of quadrature filters (Ideal, Gabor and Sinusoidal) have been evaluated using both artificial and real EEG signals. For the artificial signals, the performance of each filter was measured in terms of the distortion in amplitude and phase, and sensitivity to noise and bandwidth selection. For the real EEG signals, a qualitative evaluation of the dynamics of the synchronization between two EEG channels was performed. The results suggest that, while all filters under study behave similarly under noise, they differ in terms of their sensitivity to bandwidth choice. In this study, the Sinusoidal filter showed clear advantages for the estimation of low-frequency EEG synchronization.
Williams, Terrie M; Wolfe, Lisa; Davis, Tracy; Kendall, Traci; Richter, Beau; Wang, Yiwei; Bryce, Caleb; Elkaim, Gabriel Hugh; Wilmers, Christopher C
2014-10-03
Pumas (Puma concolor) live in diverse, often rugged, complex habitats. The energy they expend for hunting must account for this complexity but is difficult to measure for this and other large, cryptic carnivores. We developed and deployed a physiological SMART (species movement, acceleration, and radio tracking) collar that used accelerometry to continuously monitor energetics, movements, and behavior of free-ranging pumas. This felid species displayed marked individuality in predatory activities, ranging from low-cost sit-and-wait behaviors to constant movements with energetic costs averaging 2.3 times those predicted for running mammals. Pumas reduce these costs by remaining cryptic and precisely matching maximum pouncing force (overall dynamic body acceleration = 5.3 to 16.1g) to prey size. Such instantaneous energetics help to explain why most felids stalk and pounce, and their analysis represents a powerful approach for accurately forecasting resource demands required for survival by large, mobile predators. Copyright © 2014, American Association for the Advancement of Science.
Hanif, Muhammad
2017-03-31
The high hardware cost associated with multiple antennas at the secondary transmitter of an underlay cognitive radio (CR) can be reduced by antenna selection. This paper analyzes different power adaptive transmit antenna selection (TAS) schemes for an underlay CR, which ensure that the instantaneous interference caused by the secondary transmitter to the primary receiver is below a predetermined level. We consider the optimal continuous power adaptive TAS and present a low-complexity antenna and power level selection scheme, named sequential antenna and power level selection scheme (SAPS), for discrete power adaptation. Exact statistical characterizations of the signal-to-interference plus noise ratio at the secondary receiver are derived for the considered schemes. Based on the newly derived statistics, we prove that the considered schemes achieve the highest diversity order equaling the number of antennas at the secondary transmitter. Further, we also derive a closed-form expression of the ergodic capacity for the underlay CR with SAPS scheme. Finally, we show that the proposed scheme outperforms existing schemes in terms of ergodic capacity.
Kimble, Christopher J; Johnson, David M; Winter, Bruce A; Whitlock, Sidney V; Kressin, Kenneth R; Horne, April E; Robinson, Justin C; Bledsoe, Jonathan M; Tye, Susannah J; Chang, Su-Youne; Agnesi, Filippo; Griessenauer, Christoph J; Covey, Daniel; Shon, Young-Min; Bennet, Kevin E; Garris, Paul A; Lee, Kendall H
2009-01-01
The Wireless Instantaneous Neurotransmitter Concentration Sensing System (WINCS) measures extracellular neurotransmitter concentration in vivo and displays the data graphically in nearly real time. WINCS implements two electroanalytical methods, fast-scan cyclic voltammetry (FSCV) and fixed-potential amperometry (FPA), to measure neurotransmitter concentrations at an electrochemical sensor, typically a carbon-fiber microelectrode. WINCS comprises a battery-powered patient module and a custom software application (WINCSware) running on a nearby personal computer. The patient module impresses upon the electrochemical sensor either a constant potential (for FPA) or a time-varying waveform (for FSCV). A transimpedance amplifier converts the resulting current to a signal that is digitized and transmitted to the base station via a Bluetooth radio link. WINCSware controls the operational parameters for FPA or FSCV, and records the transmitted data stream. Filtered data is displayed in various formats, including a background-subtracted plot of sequential FSCV scans - a representation that enables users to distinguish the signatures of various analytes with considerable specificity. Dopamine, glutamate, adenosine and serotonin were selected as analytes for test trials. Proof-of-principle tests included in vitro flow-injection measurements and in vivo measurements in rat and pig. Further testing demonstrated basic functionality in a 3-Tesla MRI unit. WINCS was designed in compliance with consensus standards for medical electrical device safety, and it is anticipated that its capability for real-time intraoperative monitoring of neurotransmitter release at an implanted sensor will prove useful for advancing functional neurosurgery.
Bendas, Ehab R; Abdelbary, Aly A
2014-07-01
Recently, great attention has been paid to nanocapsules. The interest of these structures is due to their promising applications as drug delivery systems. The objective of this study was to develop novel enteric coating technique based on instantaneous encapsulation of the acid-labile drug, omeprazole in innovative enteric nanocapsules. Omeprazole enteric nanocapsules were formulated by varying the type and amount of the enteric polymer. The particle size (PS), polydispersity index (PDI), zeta potential (ZP) and encapsulation efficiency (EE) values of the prepared enteric nanocapsules were determined. A full 2(1)×3(1) factorial design was used for planning and analysis of the experimental trials to select the optimized formulation. The highest desirability value was 0.7463 for formula E3 (containing 200mg hydroxypropyl methylcellulose phthalate (HPMCP)). The stability of omeprazole was reflected by the absence of the exothermal peak when the drug was encapsulated as detected by differential scanning calorimetry (DSC) thermograms. In vitro drug release study confirmed the USP specifications required to meet the key formulation characteristics of gastro-resistance. In vivo pharmacological assessment showed that the optimized nanocapsules were able to protect rat stomach against ulcer formation compared to the aqueous suspension of the drug which showed less significant protection. Copyright © 2014 Elsevier B.V. All rights reserved.
Development of an instantaneous local fuel-concentration measurement probe: an engine application
Guibert, P.; Boutar, Z.; Lemoyne, L.
2003-11-01
This work presents a new tool which can deliver instantaneous local measurements of fuel concentration in an engine cylinder with a high temporal resolution, particularly during compression strokes. Fuel concentration is represented by means of equivalence fuel-air ratio, i.e. the real engine mass ratio of fuel to air divided by the same ratio in ideal stoichiometry conditions. Controlling the mixture configuration for any strategy in a spark ignition engine and for auto-ignition combustion has a dominant effect on the subsequent processes of ignition, flame propagation and auto-ignition combustion progression, pollutant formation under lean or even stoichiometric operating conditions. It is extremely difficult, under a transient operation, to control the equivalence air/fuel ratio precisely at a required value and at the right time. This requires the development of a highly accurate equivalence air/fuel ratio control system and a tool to measure using crank angle (CA) resolution. Although non-intrusive laser techniques have considerable advantages, they are most of the time inappropriate due to their optical inaccessibility or the complex experimental set-up involved. Therefore, as a response to the demand for a relatively simple fuel-concentration measurement system a probe is presented that replaces a spark plug and allows the engine to run completely normally. The probe is based on hot-wire like apparatus, but involves catalytic oxidation at the wire surface. The development, characteristics and calibration of the probe are presented followed by applications to in-cylinder engine measurements.
International Nuclear Information System (INIS)
Wang, Zuo-Cai; Chen, Gen-Da
2013-01-01
In this study, the recently developed analytical mode decomposition with Hilbert transform was extended to the decomposition of a non-stationary and nonlinear signal with two or more amplitude-decaying and frequency-changing components. The bisecting frequency in the analytical mode decomposition became time-varying, and could be selected between any two adjacent instantaneous frequencies estimated from a preliminary wavelet analysis. The mathematical foundation for this new extension was integration of the bisecting frequency over time so that the original time series is actually decomposed in the phase domain. Parametric studies indicated that the analytically derived components are insensitive to the selection of bisecting frequency and the presence of up to 20% noise, sufficiently accurate when the sampling rate meets the Nyquist–Shannon sampling criterion, and applicable to both narrowband and wideband frequency modulations even when the signal amplitude decays over time. The proposed analytical mode decomposition is superior to the empirical mode decomposition and wavelet analysis in the preservation of signal amplitude, frequency and phase relations. It can be directly applied for system identification of buildings with time-varying stiffness. (paper)
Front-Crawl Instantaneous Velocity Estimation Using a Wearable Inertial Measurement Unit
Directory of Open Access Journals (Sweden)
Kamiar Aminian
2012-09-01
Full Text Available Monitoring the performance is a crucial task for elite sports during both training and competition. Velocity is the key parameter of performance in swimming, but swimming performance evaluation remains immature due to the complexities of measurements in water. The purpose of this study is to use a single inertial measurement unit (IMU to estimate front crawl velocity. Thirty swimmers, equipped with an IMU on the sacrum, each performed four different velocity trials of 25 m in ascending order. A tethered speedometer was used as the velocity measurement reference. Deployment of biomechanical constraints of front crawl locomotion and change detection framework on acceleration signal paved the way for a drift-free integration of forward acceleration using IMU to estimate the swimmers velocity. A difference of 0.6 ± 5.4 cm·s−1 on mean cycle velocity and an RMS difference of 11.3 cm·s−1 in instantaneous velocity estimation were observed between IMU and the reference. The most important contribution of the study is a new practical tool for objective evaluation of swimming performance. A single body-worn IMU provides timely feedback for coaches and sport scientists without any complicated setup or restraining the swimmer’s natural technique.
Directory of Open Access Journals (Sweden)
Jaco H. Visser
2012-03-01
Full Text Available The accumulating-type (or integrating-type NOx sensor principle offers two operation modes to measure low levels of NOx: The direct signal gives the total amount dosed over a time interval and its derivative the instantaneous concentration. With a linear sensor response, no baseline drift, and both response times and recovery times in the range of the gas exchange time of the test bench (5 to 7 s, the integrating sensor is well suited to reliably detect low levels of NOx. Experimental results are presented demonstrating the sensor’s integrating properties for the total amount detection and its sensitivity to both NO and to NO2. We also show the correlation between the derivative of the sensor signal and the known gas concentration. The long-term detection of NOx in the sub-ppm range (e.g., for air quality measurements is discussed. Additionally, a self-adaption of the measurement range taking advantage of the temperature dependency of the sensitivity is addressed.
An Instantaneous Low-Cost Point-of-Care Anemia Detection Device
Directory of Open Access Journals (Sweden)
Jaime Punter-Villagrasa
2015-02-01
Full Text Available We present a small, compact and portable device for point-of-care instantaneous early detection of anemia. The method used is based on direct hematocrit measurement from whole blood samples by means of impedance analysis. This device consists of a custom electronic instrumentation and a plug-and-play disposable sensor. The designed electronics rely on straightforward standards for low power consumption, resulting in a robust and low consumption device making it completely mobile with a long battery life. Another approach could be powering the system based on other solutions like indoor solar cells, or applying energy-harvesting solutions in order to remove the batteries. The sensing system is based on a disposable low-cost label-free three gold electrode commercial sensor for 50 µL blood samples. The device capability for anemia detection has been validated through 24 blood samples, obtained from four hospitalized patients at Hospital Clínic. As a result, the response, effectiveness and robustness of the portable point-of-care device to detect anemia has been proved with an accuracy error of 2.83% and a mean coefficient of variation of 2.57% without any particular case above 5%.
International Nuclear Information System (INIS)
Wundt, B.J.; Jentschura, U.D.
2012-01-01
We investigate the coupling of the electromagnetic sources (charge and current densities) to the scalar and vector potentials in classical electrodynamics, using Green function techniques. As is well known, the scalar potential shows an action-at-a-distance behavior in Coulomb gauge. The conundrum generated by the instantaneous interaction has intrigued physicists for a long time. Starting from the differential equations that couple the sources to the potentials, we here show in a concise derivation, using the retarded Green function, how the instantaneous interaction cancels in the calculation of the electric field. The time derivative of a specific additional term in the vector potential, present only in Coulomb gauge, yields a supplementary contribution to the electric field which cancels the gradient of the instantaneous Coulomb gauge scalar potential, as required by gauge invariance. This completely eliminates the contribution of the instantaneous interaction from the electric field. It turns out that a careful formulation of the retarded Green function, inspired by field theory, is required in order to correctly treat boundary terms in partial integrations. Finally, compact integral representations are derived for the Liénard–Wiechert potentials (scalar and vector) in Coulomb gauge which manifestly contain two compensating action-at-a-distance terms. - Highlights: ► We investigate action-at-a-distance effects in electrodynamics in detail. ► We calculate the instantaneous interactions for scalar and vector potentials. ► The cancellation mechanism involves the retarded Green function. ► The mechanism is confirmed on the example of moving point charges. ► The Green function has to be treated with care for nontrivial boundary terms.
Inversion assuming weak scattering
DEFF Research Database (Denmark)
Xenaki, Angeliki; Gerstoft, Peter; Mosegaard, Klaus
2013-01-01
due to the complex nature of the field. A method based on linear inversion is employed to infer information about the statistical properties of the scattering field from the obtained cross-spectral matrix. A synthetic example based on an active high-frequency sonar demonstrates that the proposed...
2010-10-01
... 42 Public Health 1 2010-10-01 2010-10-01 false Do Self-Governance Tribes become Federal agencies... HEALTH AND HUMAN SERVICES TRIBAL SELF-GOVERNANCE Construction Nepa Process § 137.286 Do Self-Governance... Self-Governance Tribes are required to assume Federal environmental responsibilities for projects in...
2010-10-01
... 42 Public Health 1 2010-10-01 2010-10-01 false May Self-Governance Tribes carry out construction... OF HEALTH AND HUMAN SERVICES TRIBAL SELF-GOVERNANCE Construction Nepa Process § 137.291 May Self-Governance Tribes carry out construction projects without assuming these Federal environmental...
2010-04-01
... different types of energy resources? 224.64 Section 224.64 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF... Requirements § 224.64 How may a tribe assume management of development of different types of energy resources... develop that type of energy resource and will trigger the public notice and opportunity for comment...
Effects of an assumed cosmic ray-modulated low global cloud cover on the Earth's temperature
Energy Technology Data Exchange (ETDEWEB)
Ramirez, J.; Mendoza, B. [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico); Mendoza, V.; Adem, J. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: victor@atmosfera.unam.mx
2006-07-15
We have used the Thermodynamic Model of the Climate to estimate the effect of variations in the low cloud cover on the surface temperature of the Earth in the Northern Hemisphere during the period 1984-1994. We assume that the variations in the low cloud cover are proportional to the variation of the cosmic ray flux measured during the same period. The results indicate that the effect in the surface temperature is more significant in the continents, where for July of 1991, we have found anomalies of the order of 0.7 degrees Celsius for the southeastern of Asia and 0.5 degrees Celsius for the northeast of Mexico. For an increase of 0.75% in the low cloud cover, the surface temperature computed by the model in the North Hemisphere presents a decrease of {approx} 0.11 degrees Celsius; however, for a decrease of 0.90% in the low cloud cover, the model gives an increase in the surface temperature of {approx} 0.15 degrees Celsius, these two cases correspond to a climate sensitivity factor for the case of forcing by duplication of atmospheric CO{sub 2}. These decreases or increases in surface temperature by increases of decreases in low clouds cover are ten times greater than the overall variability of the non-forced model time series. [Spanish] Hemos usado el Modelo Termodinamico del Clima para estimar el efecto de variaciones en la cubierta de nubes bajas sobre la temperatura superficial de la Tierra en el Hemisferio Norte durante el periodo 1984 - 1994. Suponemos que las variaciones en la cubierta de nubes bajas son proporcionales a las variaciones del flujo de rayos cosmicos medido durante el mismo periodo. Los resultados indican que el efecto en la temperatura es mas significativo en los continentes, donde para julio de 1991, hemos encontrado anomalias del orden de 0.7 grados Celsius sobre el sureste de Asia y 0.5 grados Celsius al noreste de Mexico. Para un incremento de 0.75% en la cubierta de nubes bajas, la temperatura de la superficie calculada por el modelo en
Real-time multi-peak tractography for instantaneous connectivity display.
Chamberland, Maxime; Whittingstall, Kevin; Fortin, David; Mathieu, David; Descoteaux, Maxime
2014-01-01
The computerized process of reconstructing white matter tracts from diffusion MRI (dMRI) data is often referred to as tractography. Tractography is nowadays central in structural connectivity since it is the only non-invasive technique to obtain information about brain wiring. Most publicly available tractography techniques and most studies are based on a fixed set of tractography parameters. However, the scale and curvature of fiber bundles can vary from region to region in the brain. Therefore, depending on the area of interest or subject (e.g., healthy control vs. tumor patient), optimal tracking parameters can be dramatically different. As a result, a slight change in tracking parameters may return different connectivity profiles and complicate the interpretation of the results. Having access to tractography parameters can thus be advantageous, as it will help in better isolating those which are sensitive to certain streamline features and potentially converge on optimal settings which are area-specific. In this work, we propose a real-time fiber tracking (RTT) tool which can instantaneously compute and display streamlines. To achieve such real-time performance, we propose a novel evolution equation based on the upsampled principal directions, also called peaks, extracted at each voxel of the dMRI dataset. The technique runs on a single Computer Processing Unit (CPU) without the need for Graphical Unit Processing (GPU) programming. We qualitatively illustrate and quantitatively evaluate our novel multi-peak RTT technique on phantom and human datasets in comparison with the state of the art offline tractography from MRtrix, which is robust to fiber crossings. Finally, we show how our RTT tool facilitates neurosurgical planning and allows one to find fibers that infiltrate tumor areas, otherwise missing when using the standard default tracking parameters.
Active power compensator of the current harmonics based on the instantaneous power theory
Directory of Open Access Journals (Sweden)
Marian GAICEANU
2005-12-01
Full Text Available The quality of the electrical current becomes a major concern. The proliferation of the power electronic converters, which are used extensively to control electrical apparatus in industrial and commercial applications (dc and ac variable speed motor drives, induction furnaces, power line conditioners, and industrial power supplies, is at the origin of the AC current distribution network pollution and the reactive power demand. These power electronic converters typically draw non-sinusoidal currents from the utility, causing interference with adjacent sensitive loads and limit the utilization of the available electrical supply. The quality of the electrical current thus becomes a significant concern for the distributors of energy and their customers. Recent progress as regards technology of the power electronics brings a capacity of compensation and correction of the harmonic distortion generated by the nonlinear loads. In this paper a parallel active filter prototype capable of reducing the total harmonic distortion in the supply for most current source or adjustable speed drive type loads is presented. A 33 kVA active power filter was developed for harmonic and reactive power compensation based on the instantaneous power theory. The active filter configuration requires the measurement of both the load and filter currents. Experimental results from a prototype active power filter confirm the suitability of the proposed approach. The actual 33kVA prototype converter has been built and tested in the SIEI S.p.A. (Italy laboratory under the Marie Curie Post Doctoral research. The active power compensator is controlled by a high performance DSP platform, resulting in the following active filter features: source current reduction up to the 25th harmonic, 10% THD achievable for current source type loads, efficiency above 97%, does not cause resonance with other loads, operation in the presence of unbalanced loads, reactive power and harmonics
Coelho, A C; Cannon, D T; Cao, R; Porszasz, J; Casaburi, R; Knorst, M M; Rossiter, H B
2015-03-01
A rapid switch from hyperbolic to isokinetic cycling allows the velocity-specific decline in maximal power to be measured, i.e., fatigue. We reasoned that, should the baseline relationship between isokinetic power (Piso) and electromyography (EMG) be reproducible, then contributions to fatigue may be isolated from 1) the decline in muscle activation (muscle activation fatigue); and 2) the decline in Piso at a given activation (muscle fatigue). We hypothesized that the EMG-Piso relationship is linear, velocity dependent, and reliable for instantaneous fatigue assessment at intolerance during and following whole body exercise. Healthy participants (n = 13) completed short (5 s) variable-effort isokinetic bouts at 50, 70, and 100 rpm to characterize baseline EMG-Piso. Repeated ramp incremental exercise tests were terminated with maximal isokinetic cycling (5 s) at 70 rpm. Individual baseline EMG-Piso relationships were linear (r(2) = 0.95 ± 0.04) and velocity dependent (analysis of covariance). Piso at intolerance (two legs, 335 ± 88 W) was ∼45% less than baseline [630 ± 156 W, confidence interval of the difference (CIDifference) 211, 380 W, P fatigue and muscle fatigue (one leg) were 97 ± 55 and 60 ± 50 W, respectively. Mean bias ± limits of agreement for reproducibility were as follows: baseline Piso 1 ± 30 W; Piso at 0-min recovery 3 ± 35 W; and EMG at Piso 3 ± 14%. EMG power is linear, velocity dependent, and reproducible. Deviation from this relationship at the limit of tolerance can quantify the "activation" and "muscle" related components of fatigue during cycling. Copyright © 2015 the American Physiological Society.
Three days rush venom immunotherapy in bee allergy: safe, inexpensive and instantaneously effective.
Goldberg, Arnon; Yogev, Ayala; Confino-Cohen, Ronit
2011-01-01
Rush venom immunotherapy (VIT) is highly effective in vespid venom allergy, but comparable data regarding bee venom (BV) allergy are sparse. We evaluated its safety, efficacy and cost in BV-allergic patients. Conventional or rush VIT were offered to all patients with systemic reaction to insect sting. Rush VIT was also given to hyperreactive patients who failed to reach the maintenance dose with conventional VIT due to multiple systemic reactions. In BV-allergic patients, honeybee sting challenge was performed within 1 week after reaching the maintenance dose. 179 patients, some of them allergic to more than one venom, received 246 rush VIT courses. Bee VIT was administered to 132 patients (73.7%); 173 patients (96.6%) reached the maintenance dose. The incidence of systemic reactions was 29.6%. They were more common in VIT with BV than with vespid venoms (31.1 and 16.3%, respectively, p = 0.01). After excluding the hyperreactive subgroup (n = 20), this difference was not significant (23.7 and 16%, respectively, p = 0.19). Despite the high incidence of systemic reactions (15 of 20, 75%) among hyperreactive patients, 17 patients (85%) achieved the maintenance dose. Sting challenges resulted in systemic reaction in 4 of 8 (50%) hyperreactive patients and in 2 of 47 (4.3%) ordinary patients. The cost of rush VIT was 41% of that of conventional VIT. Rush VIT with BV is safe, instantaneously effective, less expensive and enables most patients with previous failures of conventional VIT to reach the maintenance dose. Copyright © 2011 S. Karger AG, Basel.
International Nuclear Information System (INIS)
Antonopoulos, Antonis K.; Hountalas, Dimitrios T.
2012-01-01
Highlights: ► The effect of in-cycle speed fluctuation on cylinder pressure measurement is investigated. ► A phasing error is introduced when sampling cylinder pressure at constant time intervals. ► The phasing error increases with the increase of engine load and decrease of engine speed. ► Measurement using constant sampling rate affects estimation of HRR, ignition angle etc. - Abstract: Diesel engine cylinder pressure measurements are widely used in field and lab applications to support among other control, monitoring and diagnostic applications. There are two methods to measure cylinder pressure, the use of a crank angle encoder, which guarantees pressure samples at fixed crank angles, and the use of constant time sampling rate. The last is frequently used due to its simplicity or because of practical restrictions. However, in order to perform thermodynamic calculations it is necessary to attribute a crank angle value to each measured pressure value. But if the in-cycle rotational speed fluctuates and this is neglected, an error will result in the values derived from the processing of the measured cylinder pressure. For this reason in the present work an experimental investigation is conducted on a single cylinder diesel test engine to identify the aforementioned problem. During the tests cylinder pressure and instantaneous speed were recorded using an accurate crank angle reference. These where then used to simulate the measurement of cylinder pressure digitized using a fixed time step. The comparison of the two cylinder pressure traces and the thermodynamic parameters derived from them, reveals the introduction of an error which depends on engine load and speed.
Real-time multi-peak tractography for instantaneous connectivity display
Directory of Open Access Journals (Sweden)
Maxime eChamberland
2014-05-01
Full Text Available The computerized process of reconstructing white matter tracts from diffusion MRI (dMRI data is often referred to as tractography. Tractography is nowadays central in structural connectivity since it is the only non-invasive technique to obtain information about brain wiring. Most publicly available tractography techniques and most studies are based on a fixed set of tractography parameters. However, the scale and curvature of fiber bundles can vary from region to region in the brain. Therefore, depending on the area of interest or subject (e.g. healthy control vs. tumor patient, optimal tracking parameters can be dramatically different. As a result, a slight change in tracking parameters may return different connectivity profiles and complicate the interpretation of the results. Having access to tractography parameters can thus be advantageous, as it will help in better isolating those which are sensitive to certain streamline features and potentially converge on optimal settings which are area-specific. In this work, we propose a real-time fiber tracking (RTT tool which can instantaneously compute and display streamlines. To achieve such real-time performance, we propose a novel evolution equation based on the upsampled principal directions, also called peaks, extracted at each voxel of the dMRI dataset. The technique runs on a single Computer Processing Unit (CPU without the need for Graphical Unit Processing (GPU programming. We qualitatively illustrate and quantitatively evaluate our novel multi-peak RTT technique on phantom and human datasets in comparison with the state of the art offline tractography from MRtrix, which is robust to fiber crossings. Finally, we show how our RTT tool facilitates neurosurgical planning and allows one to find fibers that infiltrate tumor areas, otherwise missing when using the standard default tracking parameters.
Directory of Open Access Journals (Sweden)
D. T. Do
2017-09-01
Full Text Available In this investigation, we consider wireless powered relaying systems, where energy is scavenged by a relay via radio frequency (RF signals. We explore hybrid time switching-based and power splitting-based relaying protocol (HTPSR and compare performance of Amplify-and-Forward (AF with Decode-and-Forward (DF scheme under imperfect channel state information (CSI. Most importantly, the instantaneous rate, achievable bit error rate (BER are determined in the closed-form expressions under the impact of imperfect CSI. Through numerical analysis, we evaluate system insights via different parameters such as power splitting (PS and time switching (TS ratio of the considered HTPSR which affect outage performance and BER. It is noted that DF relaying networks outperform AF relaying networks. Besides that, the numerical results are given to prove the optimization problems of PS and TS ratio to obtain optimal instantaneous rate.
Valenza, G.; Greco, A.; Gentili, C.; Lanata, A.; Sebastiani, L.; Menicucci, D.; Gemignani, A.; Scilingo, E. P.
2016-01-01
Emotion perception, occurring in brain areas such as the prefrontal cortex and amygdala, involves autonomic responses affecting cardiovascular dynamics. However, how such brain–heart dynamics is further modulated by emotional valence (pleasantness/unpleasantness), also considering different arousing levels (the intensity of the emotional stimuli), is still unknown. To this extent, we combined electroencephalographic (EEG) dynamics and instantaneous heart rate estimates to study emotional proc...
Directory of Open Access Journals (Sweden)
Valentina Lo Mauro
2014-09-01
Full Text Available The present work describes an analysis of the metamorphosis of temporality in late modernity and the changes that this transformation gives to the forms of identity and psychopathological vulnerability, particularly in the relationship between the temporal dimension of instantaneity and borderline phenomenology. It is dealt with in depth artistic production, through which it is possible to re-cross the clinical experience of the therapeutic relationship.Keywords: Istantaneity; Borderline phenomenolgy; Art production
Goker, A.; Gedik, E.
2013-09-01
We investigate the effect of contact material on the instantaneous thermoelectric response of a quantum dot pushed suddenly into the Kondo regime via a gate voltage using time dependent non-crossing approximation and linear response Onsager relations. We utilize graphene and metal contacts for this purpose. Instantaneous thermopower displays sinusoidal oscillations whose frequency is proportional to the energy separation between the van Hove singularity in the contact density of states and the Fermi level for both cases, regardless of the asymmetry factor at the onset of the Kondo timescale. The amplitude of the oscillations increases with decreasing temperature, saturating around the Kondo temperature. We also calculate the instantaneous figure of merit and show that the oscillations taking place at temperatures above the Kondo temperature are enhanced more than the ones occurring at lower temperatures due to the violation of the Wiedemann-Franz law. Graphene emerges as a more promising electrode candidate than ordinary metals in single electron devices since it can minimize these oscillations.
Park, Seong-Ryong; Wallace, James M.
1993-11-01
The necessary assumption that the instantaneous flow field seen by hot-wire probes with two or more sensors is uniform, i.e. that all sensors are cooled by identically the same instantaneous velocity field, is often quite erroneous in highly sheared turbulent flow, such as near the wall in a turbulent boundary layer. Intense local shear layers occur, resulting in large instantaneous velocity gradients across the sensing volume of the probe. The effects of these neglected velocity gradients on the ability of a four-sensor probe, consisting of a pair of orthogonal X-arrays, to measure the three velocity and the streamwise vorticity components is assessed. This is done by determining the synthetic response of the probe to the turbulent boundary layer database of Balint et al. (1991), in which all the velocity gradients are known. The effects of neglecting the binormal components of velocity which cool each sensor are also assessed, when the probe is treated as two uncoupled X-arrays. A small improvement to the probe's coupled X-array response is found when an estimate of the mean wall-normal velocity gradient is incorporated in the response equations.
Wu, T. Y.; Chen, J. C.; Wang, C. C.
2012-07-01
The objective of this research is to investigate the feasibility of utilizing the instantaneous dimensionless frequency (DLF) normalization and Hilbert-Huang Transform (HHT) to characterize the different gear faults in case of variable rotating speed. The normalized DLF of the vibration signals are calculated based on the rotating speed of shaft and the instantaneous frequencies of Intrinsic Mode Functions (IMFs) which are decomposed by Empirical Mode Decomposition (EMD) process. The faulty gear features on DLF-energy distribution of vibration signal can be extracted without the presence of shaft rotating speed, so that the proposed approach can be applied for characterizing the malfunctions of gearbox system under variable shaft rotating speed. A test rig of gear transmission system is performed to illustrate the gear faults, including worn tooth, broken tooth and gear unbalance. Different methods to determine the instantaneous frequency are employed to verify the consistence of characterization results. The DLF-energy distributions of vibration signals are investigated in different faulty gear conditions. The analysis results demonstrate the capability and effectiveness of the proposed approach for characterizing the gear malfunctions at the DLFs corresponding to the meshing frequency as well as the shaft rotating frequency. The support vector machine (SVM) is then employed to classify the vibration patterns of gear transmission system at different malfunctions. Using the energy distribution at the characteristic DLFs as the features, the different fault types of gear can be identified by SVM with high accuracy.
Bilal, Jalal A; Gasim, Gasim I; Karsani, Amani H; Elbashir, Leana M; Adam, Ishag
2016-04-01
Estimating malaria parasite count is needed for estimating the severity of the disease and during the follow-up. This study was conducted to determine the malaria parasite density among children using actual white blood cell (WBC) and the assumed WBC counts (8.0 × 10(9)/l). A cross-sectional study was conducted at New Halfa Hospital, Sudan. WBC count and count of asexual malaria parasite were performed on blood films. One hundred and three children were enrolled. The mean (SD) WBCs was 6.2 (2.9) cells × 10(9)/l. The geometric mean (SD) of the parasite count using the assumed WBCs (8.0 × 10(9)/l cells/μl) was significantly higher than that estimated using the actual WBC count [7345.76 (31,038.56) vs. 5965 (28,061.57) rings/μl,p = 0.042]. Malaria parasitemia based on assumed (8.0 × 10(9)/) WBCs is higher than parasitemia based on actual WBCs. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Behavior of instantaneous lateral velocity and flow pulsation in duct flow with cylindrical rod
International Nuclear Information System (INIS)
Lee, Chi Young; Shin, Chang Hwan; Park, Ju Yong; Oh, Dong Seok; Chun, Tae Hyun; In, Wang Kee
2012-01-01
Recently, KAERI (Korea Atomic Energy Research Institute) has examined and developed a dual cooled annular fuel. Dual cooled annular fuel allows the coolant to flow through the inner channel as well as the outer channel. Due to inner channel, the outer diameter of dual cooled annular fuel (15.9 mm) is larger than that of conventional cylindrical solid fuel (9.5 mm). Hence, dual cooled annular fuel assembly becomes a tight lattice fuel bundle configuration to maintain the same array size and guide tube locations as cylindrical solid fuel assembly. P/Ds (pitch between rods to rod diameter ratio) of dual cooled annular and cylindrical solid fuel assemblies are 1.08 and 1.35, respectively. This difference of P/D could change the behavior of turbulent flow in rod bundle. Our research group has investigated a turbulent flow parallel to the fuel rods using two kinds of simulated 3x3 rod bundles. To measure the turbulent rod bundle flow, PIV (Particle Image Velocimetry) and MIR (Matching Index of Refraction) techniques were used. In a simulated dual cooled annular fuel bundle (i.e., P/D=1.08), the quasi periodic oscillating flow motion in the lateral direction, called the flow pulsation, was observed, which significantly increased the lateral turbulence intensity at the rod gap center. The flow pulsation was visualized and measured clearly and successfully by PIV and MIR techniques. Such a flow motion may have influence on the fluid induced vibration, heat transfer, CHF (Critical Heat Flux), and flow mixing between subchannels in rod bundle flow. On the other hand, in a simulated cylindrical solid fuel bundle (i.e., P/D=1.35), the peak of turbulence intensity at the gap center was not measured due to an irregular motion of the lateral flow. This study implies that the behavior of lateral velocity in rod bundle flow is greatly influenced by the P/D (i.e., gap distance). In this work, the influence of gap distance on behavior of instantaneous lateral velocity and flow
Long, Run; Prezhdo, Oleg V
2014-03-19
Photoexcitation of the plasmon band in metallic nanoparticles adsorbed on a TiO2 surface initiates many important photovoltaic and photocatalytic processes. The traditional view on the photoinduced charge separation involves excitation of a surface plasmon, its subsequent dephasing into electron-hole pairs, followed by electron transfer (ET) from the metal nanoparticle into TiO2. We use nonadiabatic molecular dynamics combined with time-domain density functional theory to demonstrate that an electron appears inside TiO2 immediately upon photoexcitation with a high probability (~50%), bypassing the intermediate step of electron-hole thermalization inside the nanoparticle. By providing a detailed, atomistic description of the charge separation, energy relaxation, and electron-hole recombination processes, the simulation rationalizes why the experimentally observed ultrafast photoinduced ET in an Au-TiO2 system is possible in spite of the fast energy relaxation. The simulation shows that the photogenerated plasmon is highly delocalized onto TiO2, and thus, it is shared by the electron donor and acceptor materials. In the 50% of the cases remaining after the instantaneous photogeneration of the charge-separated state, the electron injects into TiO2 on a sub-100 fs time scale by the nonadiabatic mechanism due to high density of acceptor states. The electron-phonon relaxation parallels the injection and is slower, resulting in a transient heating of the TiO2 surface by 40 K. Driven by entropy, the electron moves further into TiO2 bulk. If the electron remains trapped at the TiO2 surface, it recombines with the hole on a picosecond time scale. The obtained ET and recombination times are in excellent agreement with the experiment. The delocalized plasmon state observed in our study establishes a novel concept for plasmonic photosensitization of wide band gap semiconductors, leading to efficient conversion of photons to charge carriers and to hybrid materials with a wide
The impact of tissue Doppler index E/e' ratio on instantaneous wave-free ratio.
Arashi, Hiroyuki; Yamaguchi, Junichi; Ri, Tonre; Otsuki, Hisao; Nakao, Masashi; Kamishima, Kazuho; Jujo, Kentaro; Minami, Yuichiro; Ogawa, Hiroshi; Hagiwara, Nobuhisa
2018-03-01
The instantaneous wave-free ratio (iFR) is a vasodilator-free, invasive pressure wire index of the functional severity of coronary stenosis and is calculated under resting conditions. In a recent study, iFR was found to be more closely linked to coronary flow reserve (CFR) than fractional flow reserve (FFR). E/e' is a surrogate marker of left ventricular (LV) filling pressure and LV diastolic dysfunction. Coronary resting flow was found to be increased in patients with elevated E/e', and higher coronary resting flow was associated with lower CFR. Higher baseline coronary flow induces a greater loss of translesional pressure and may affect iFR. However, no reports have examined the impact of E/e' on iFR. The purpose of this study was to assess the relationship between iFR and E/e' compared with FFR. We retrospectively examined 103 consecutive patients (142 with stenosis) whose iFR, FFR, and E/e' were measured simultaneously. The mean age, LV mass index, and systolic blood pressure of patients with elevated E/e' were higher than those of patients with normal E/e'. Although no significant differences were observed in mean FFR values and % diameter stenosis, the mean iFR value in patients with elevated E/e' was significantly lower than that in patients with normal E/e'. The iFR was negatively correlated with E/e', while there was no correlation between FFR and E/e'. Multivariate analysis showed that E/e' and % diameter stenosis were independent determinants of iFR. E/e' ratio affects iFR values. Our results suggest that FFR mainly reflects the functional severity of the epicardial stenosis whereas iFR could potentially be influenced by not only epicardial stenosis but also other factors related to LV filling pressure or LV diastolic dysfunction. Further research is needed to understand the underlying mechanisms that influence the evaluation of iFR in patients with elevated E/e'. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights
Energy Technology Data Exchange (ETDEWEB)
Enomoto, Y.; Hagihara, Y. [Musashi Institute of Technology, Tokyo (Japan); Kimura, S. [Nissan Motor Co. Ltd., Tokyo (Japan); Adachi, K. [Daido Hoxan Inc., Sapporo (Japan); Nagano, H. [Riso Kagaku Corp., Tokyo (Japan); Ishii, A. [Mitani Sangyo Co. Ltd., Tokyo (Japan)
1998-08-25
To evaluate the effectiveness of low heat rejection engine under heat loss condition, instantaneous heat fluxes flowing into ceramic piston surface and aluminum alloy (Loex) piston surface using thin film thermocouple were measured, and both were compared. As a result, in the working stroke, the instantaneous heat flux flowing into ceramic piston surface was larger than the instantaneous heat flux flowing into Loex piston surface. Accordingly, it became clear that reduction of heat loss was not effected when ceramics that thermal conductivity is small was used for combustion chamber wall. 21 refs., 14 figs.
Hassan, Junaid; Qu, Zhi; Bergaust, Linda L; Bakken, Lars R
2016-01-01
Denitrifying bacteria accumulate [Formula: see text], NO, and N2O, the amounts depending on transcriptional regulation of core denitrification genes in response to O2-limiting conditions. The genes include nar, nir, nor and nosZ, encoding [Formula: see text]-, [Formula: see text]-, NO- and N2O reductase, respectively. We previously constructed a dynamic model to simulate growth and respiration in batch cultures of Paracoccus denitrificans. The observed denitrification kinetics were adequately simulated by assuming a stochastic initiation of nir-transcription in each cell with an extremely low probability (0.5% h-1), leading to product- and substrate-induced transcription of nir and nor, respectively, via NO. Thus, the model predicted cell diversification: after O2 depletion, only a small fraction was able to grow by reducing [Formula: see text]. Here we have extended the model to simulate batch cultivation with [Formula: see text], i.e., [Formula: see text], NO, N2O, and N2 kinetics, measured in a novel experiment including frequent measurements of [Formula: see text]. Pa. denitrificans reduced practically all [Formula: see text] to [Formula: see text] before initiating gas production. The [Formula: see text] production is adequately simulated by assuming stochastic nar-transcription, as that for nirS, but with a higher probability (0.035 h-1) and initiating at a higher O2 concentration. Our model assumes that all cells express nosZ, thus predicting that a majority of cells have only N2O-reductase (A), while a minority (B) has [Formula: see text]-, NO- and N2O-reductase. Population B has a higher cell-specific respiration rate than A because the latter can only use N2O produced by B. Thus, the ratio [Formula: see text] is low immediately after O2 depletion, but increases throughout the anoxic phase because B grows faster than A. As a result, the model predicts initially low but gradually increasing N2O concentration throughout the anoxic phase, as observed. The
Angelidis, Christine
2013-04-01
Remote assessment of instantaneous changes in water chemistry after liming in a Nova Scotia catchment ANGELIDIS, C.1, STERLING, S.1, BREEN, A.2, BIAGI, K.1., and CLAIR, T.A.1 1Dalhousie University, christine.angelidis@dal.ca, 2Bluenose Coastal Action Foundation, andrew@coastalaction.org Southwestern Nova Scotia has some of the most acidic freshwaters in North America due to its location downwind of the major emission sources in eastern Canada and the US and due to a resistant geology which offers little acid buffering capacity (Clair et al. 2007). Because of the poor buffering and regionally high runoff values, hydrological events such as snowmelt and rain storms are frequent and can cause sudden changes in water chemistry which can have devastating effects on freshwater biota due to increases in acidity and metals (Dennis and Clair in press). Clair et al. (2001) have estimated the potential frequency of acidic episodes in this region based on a number of hydrological factors, though the technology available at the time to monitor short-term changes was not dependable. Recent advances in equipment have made the assessment of the frequency and severity of acidic episodes easier and more accurate, allowing better interpretation and prediction of hydrogeochemical changes with variations in weather and deposition patterns. Here we take advantage of these recent advances to monitor water chemistry in an experimental catchment, and explore the response to catchment liming. Catchment liming is one way of mitigating the effects of acid deposition in sensitive areas. We limed a 50 ha catchment at a rate of 5 t/ha in the Gold River watershed of southwest Nova Scotia to examine the interactions between application of lime with the geological and climatological conditions of this region and acid episode frequency. In order to assess changes of episode frequency caused by liming, we established two mobile environmental monitoring platforms in the catchment: a control site
Gaudot, Ianis; Beucler, Éric; Mocquet, Antoine; Schimmel, Martin; Le Feuvre, Mathieu
2016-04-01
In order to detect possible signal redundancies in the seismic ambient wavefield, we develop a new method based on pairwise comparisons among a set of synchronous time-series. This approach is based on instantaneous phase coherence statistics. The first and second moments of the pairwise phase coherence distribution are used to characterize the phase randomness. Both theory and synthetic experiments show that, for perfect phase randomness, the theoretical values of the mean and variance are equal to 0 and 1 - 2/π, respectively. As a consequence, any deviation from these values indicates the presence of a redundant phase in the raw continuous signal. Using the ergodicity property of a random signal, we split an initial time-series into a set of synchronous signals. This allows us to detect and to quantify the repetitiveness of any possible temporally persistent and spatially localized source, during a given period of observation. In the case of the detection of a redundant phase, individual coherences (one trace against all others) quantify the contribution of each time-series independently. A previously detected 26 s period microseismic source located near the Gulf of Guinea is used to illustrate one of the possible ways of handling phase coherence statistics. We use the continuous vertical component data recorded during the month of 2004 August by four broad-band stations of the Federation of Digital Seismography Network. To compute coherence statistics among a set composed of a sufficient number of synchronous traces, the raw seismic signal is split into 372 2-hr sliding time windows. Only the basic signal processing steps (including removing the mean, trend and the instrumental response) are applied. After bandpass filtering the data between 23 and 32 s periods, the 2-hr time-series are cross-correlated, leading to a set of 372 synchronous cross-correlations for each station pair. We observe that, for all station pairs, the mean overall coherence value is close
Segel, Michael J; Bobrovsky, Ben-Zion; Gabbay, Itay E; Ben-Dov, Issahar; Reuveny, Ronen; Gabbay, Uri
2017-05-01
The Cardio-vascular reserve index (CVRI) had been empirically validated in diverse morbidities as a quantitative estimate of the reserve assumed by the cardiovascular reserve hypothesis. This work evaluates whether CVRI during exercise complies with the cardiovascular reserve hypothesis. Retrospective study based on a database of patients who underwent cardio-pulmonary exercise testing (CPX) for diverse indications. Patient's physiological measurements were retrieved at four predefined CPX stages (rest, anaerobic threshold, peak exercise and after 2min of recovery). CVRI was individually calculated retrospectively at each stage. Mean CVRI at rest was 0.81, significantly higher (p0.05). CVRI after 2min of recovery rose considerably, most in the group with the best exercise capacity and least in those with the lowest exercise capacity. CVRI during exercise fits the pattern predicted by the cardiovascular reserve hypothesis. CVRI decreased with exercise reaching a minimum at peak exercise and rising with recovery. The CVRI nadir at peak exercise, similar across groups classified by exercise capacity, complies with the assumed exhaustion threshold. The clinical utility of CVRI should be further evaluated. Copyright © 2017 Elsevier B.V. All rights reserved.
Zito, Sarah; Morton, John; Vankan, Dianne; Paterson, Mandy; Bennett, Pauleen C; Rand, Jacquie; Phillips, Clive J C
2016-01-01
Most cats surrendered to nonhuman animal shelters are identified as unowned, and the surrender reason for these cats is usually simply recorded as "stray." A cross-sectional study was conducted with people surrendering cats to 4 Australian animal shelters. Surrenderers of unowned cats commonly gave surrender reasons relating to concern for the cat and his/her welfare. Seventeen percent of noncaregivers had considered adopting the cat. Barriers to assuming ownership most commonly related to responsible ownership concerns. Unwanted kittens commonly contributed to the decision to surrender for both caregivers and noncaregivers. Nonowners gave more surrender reasons than owners, although many owners also gave multiple surrender reasons. These findings highlight the multifactorial nature of the decision-making process leading to surrender and demonstrate that recording only one reason for surrender does not capture the complexity of the surrender decision. Collecting information about multiple reasons for surrender, particularly reasons for surrender of unowned cats and barriers to assuming ownership, could help to develop strategies to reduce the number of cats surrendered.
National Aeronautics and Space Administration — The MAI1NXINT or inst1_2d_int_Nx data product is the MERRA Data Assimilation System 2-Dimensional vertical integral that is Instantaneous single-level at the native...
MERRA 3D Analyzed State, Meteorology Instantaneous Diurnal (p-coord, 2/3x1/2L42) V5.2.0
National Aeronautics and Space Administration — The MAIUNPANA or instU_3d_ana_Np data product is the MERRA Data Assimilation System 3-Dimensional instantaneous, on pressure levels, at native resolution. MERRA, or...
MERRA 3D Analyzed State, Meteorology Instantaneous 6-hourly (p-coord, 2/3x1/2L42) V5.2.0
National Aeronautics and Space Administration — The MAI6NPANA or inst6_3d_ana_Np data product is the MERRA Data Assimilation System 3-Dimensional instantaneous, on pressure levels, at native resolution. MERRA, or...
MERRA 3D Analyzed State, Meteorology Instantaneous Monthly (p-coord, 2/3x1/2L42) V5.2.0
National Aeronautics and Space Administration — The MAIMNPANA or instM_3d_ana_Np data product is the MERRA Data Assimilation System 3-Dimensional instantaneous, on pressure levels, at native resolution. MERRA, or...
National Oceanic and Atmospheric Administration, Department of Commerce — The file is comprised of instantaneous absolute values of the geomagnetic components D, H, and Z or X, Y, and Z at 1-minute intervals. These values were derived...
Energy Technology Data Exchange (ETDEWEB)
Oweis, Ghanem F.; Ceccio, Steven L. [University of Michigan, Department of Mechanical Engineering, Ann Arbor, MI (United States)
2005-05-01
The instantaneous and time-averaged flow fields in the tip region of a ducted marine propulsor are examined. In this flow, a primary tip-leakage vortex interacts with a secondary, co-rotating trailing edge vortex and other co- and counter-rotating vorticity found in the blade wake. Planar particle imaging velocimetry (PIV) is used to examine the flow in a plane approximately perpendicular to the mean axis of the primary vortex. An identification procedure is used to characterize multiple regions of compact vorticity in the flow fields as series of Gaussian vortices. Significant differences are found between the vortex properties from the time-averaged flow fields and the average vortex properties identified in the instantaneous flow fields. Variability in the vortical flow field results from spatial wandering of the vortices, correlated fluctuations of the vortex strength and core size, and both correlated and uncorrelated fluctuations in the relative positions of the vortices. This variability leads to pseudo-turbulent velocity fluctuations. Corrections for some of this variability are performed on the instantaneous flow fields. The resulting processed flow fields reveal a significant increase in flow variability in a region relatively far downstream of the blade trailing edge, a phenomenon that is masked through the process of simple averaging. This increased flow variability is also accompanied by the inception of discrete vortex cavitation bubbles, which is an unexpected result, since the mean flow pressures in the region of inception are much higher than the vapor pressure of the liquid. This suggests that unresolved fine-scale vortex interactions and stretching may be occurring in the region of increased flow variability. (orig.)
Oweis, Ghanem F.; Ceccio, Steven L.
2005-05-01
The instantaneous and time-averaged flow fields in the tip region of a ducted marine propulsor are examined. In this flow, a primary tip-leakage vortex interacts with a secondary, co-rotating trailing edge vortex and other co- and counter-rotating vorticity found in the blade wake. Planar particle imaging velocimetry (PIV) is used to examine the flow in a plane approximately perpendicular to the mean axis of the primary vortex. An identification procedure is used to characterize multiple regions of compact vorticity in the flow fields as series of Gaussian vortices. Significant differences are found between the vortex properties from the time-averaged flow fields and the average vortex properties identified in the instantaneous flow fields. Variability in the vortical flow field results from spatial wandering of the vortices, correlated fluctuations of the vortex strength and core size, and both correlated and uncorrelated fluctuations in the relative positions of the vortices. This variability leads to pseudo-turbulent velocity fluctuations. Corrections for some of this variability are performed on the instantaneous flow fields. The resulting processed flow fields reveal a significant increase in flow variability in a region relatively far downstream of the blade trailing edge, a phenomenon that is masked through the process of simple averaging. This increased flow variability is also accompanied by the inception of discrete vortex cavitation bubbles, which is an unexpected result, since the mean flow pressures in the region of inception are much higher than the vapor pressure of the liquid. This suggests that unresolved fine-scale vortex interactions and stretching may be occurring in the region of increased flow variability.
Directory of Open Access Journals (Sweden)
M. Ignaccolo
2012-02-01
Full Text Available We investigate the variability of the shape of the renormalized drop diameter instantaneous distribution using of the third order central moment: the skewness. Disdrometer data, collected at Darwin Australia, are considered either as whole or as divided in convective and stratiform precipitation intervals. We show that in all cases the distribution of the skewness is strongly peaked around 0.64. This allows to identify a most common distribution of renormalized drop diameters and two main variations, one with larger and one with smaller skewness. The distributions shapes are independent from the stratiform vs. convective classification.
Description of Muzzle Blast by Modified Ideal Scaling Models
Directory of Open Access Journals (Sweden)
Kevin S. Fansler
1998-01-01
Full Text Available Gun blast data from a large variety of weapons are scaled and presented for both the instantaneous energy release and the constant energy deposition rate models. For both ideal explosion models, similar amounts of data scatter occur for the peak overpressure but the instantaneous energy release model correlated the impulse data significantly better, particularly for the region in front of the gun. Two parameters that characterize gun blast are used in conjunction with the ideal scaling models to improve the data correlation. The gun-emptying parameter works particularly well with the instantaneous energy release model to improve data correlation. In particular, the impulse, especially in the forward direction of the gun, is correlated significantly better using the instantaneous energy release model coupled with the use of the gun-emptying parameter. The use of the Mach disc location parameter improves the correlation only marginally. A predictive model is obtained from the modified instantaneous energy release correlation.
International Nuclear Information System (INIS)
Kolar, Miroslav; LeNeveu, Dennis M.
1995-02-01
One of the strategies for the disposal of nuclear fuel waste is to use very long-lived containers. There is a finite chance that a very small number of these containers would have initial manufacturing defects that would lead to pinhole-type failures at the time of, or shortly after, emplacement. If the vast majority of the containers are sufficiently long-lived, only the release from the initially defected containers need be considered in modeling release rates from the disposal vault. It has been assumed that the readily leachable fraction of the used fuel would dominate releases. This readily leachable fraction (often referred to as the instant release fraction) has been modeled as a point source at the location of the pinhole in the container. Containers are considered to be emplaced in long disposal rooms backfilled with clay mixed with crushed rock or sand. Numerical calculations are done for 129 I because it has the longest half-life among the readily leachable radionuclides that would be released from a failed container. (author). 13 refs., 1 tab., 18 figs
Photography of poetry: becomings of fabulation, expanding durations and instantaneous movements
Directory of Open Access Journals (Sweden)
Laila Melchior
2015-02-01
Full Text Available The passing of time in Alessandra Sanguinetti's photographs refer to aspects of the moving image if we assume its inherent qualities of change and duration. Those are images of an encounter between cinema and photography which contaminate each other reciprocally with its own processes by expanding towards each other. There is a real durational quality that comes from the referent (the daily life of the photographed characters which turns up into fabulation giving access to other beings and other specificities of time, all of them living in the image. That is the realm of the imaginary documentary in which images evoke bifurcations, take shape and gain movement inasmuch as they cease to allude to a given and objective notion of the real referring rather to a broader notion of time as indeterminate forms of duration. The ten years that goes by during the photographic essay 'The adventures of Guille and Belinda and The enigmatic meaning of their dreams' appears therefore to be shot in a single afternoon. The durations and becomings in the passage from the characters childhoods to their adult lives - or from a superficial game to an intense performative encounter with theirselves and Sanguinetti - are based in a free indirect speech form. This particular photographic fashion of the free indirect speech comes to light by the means of apparatuses, understood in a broad sense. Those apparatuses guide the photographic and relational processes leading to the creation of slits between objectivity and subjectivity that ultimately act in order to favor temporal and immaterial aspects in the images.
Park, Sung-Bin; Noh, Yeon-Sik; Park, Sung-Jun; Yoon, Hyoung-Ro
2008-02-01
In this paper, an improved algorithm for the extraction of respiration signal from the electrocardiogram (ECG) in home healthcare is proposed. The whole system consists of two-lead electrocardiogram acquisition using conductive textile electrodes located in bed, baseline fluctuation elimination, R-wave detection, adjustment of sudden change in R-wave area using moving average, and optimal lead selection. In order to solve the problems of previous algorithms for the ECG-derived respiration (EDR) signal acquisition, we are proposing a method for the optimal lead selection. An optimal EDR signal among the three EDR signals derived from each lead (and arctangent of their ratio) is selected by estimating the instantaneous frequency using the Hilbert transform, and then choosing the signal with minimum variation of the instantaneous frequency. The proposed algorithm was tested on 15 male subjects, and we obtained satisfactory respiration signals that showed high correlation (r(2) > 0.8) with the signal acquired from the chest-belt respiration sensor.
Directory of Open Access Journals (Sweden)
Juan Felipe Martínez Plata
2012-01-01
Full Text Available This work concerned uncertainty analysis for constructing stage–discharge rating curves to estimate error or uncertainty regarding calculated discharges, considering different discharge measurement availability scenarios. A methodology was used for creating artificial samples of discharge measurements from real data observed in the field and the effect of variation on measurement quantity and distribution concerning instantaneous discharge uncertainty was then studied. The results indicated that discharge uncertainty mostly depends on the number of river discharge measurements used for rating curve calibration and on the extent of extrapolation outside the range of measured river water levels. This research found that uncertainty regarding instantaneous discharges calculated for the area within average level values could be as high as 14% when the rating curve was calibrated with few measurements. Uncertainty can reach 20% and 60% for high and low water level values, respectively, or even higher depending on the extent of rating curve extrapolation. This work established that 35 discharge measurements for rating curve calibration were needed to fulfill World Meteorological Organization standards concerning discharge defined for low water level values.
Sklansky, Mark S; DeVore, Greggory R; Wong, Pierre C
2004-02-01
Random fetal motion, rapid fetal heart rates, and cumbersome processing algorithms have limited reconstructive approaches to 3-dimensional fetal cardiac imaging. Given the recent development of real-time, instantaneous volume-rendered sonographic displays of volume data, we sought to apply this technology to fetal cardiac imaging. We obtained 1 to 6 volume data sets on each of 30 fetal hearts referred for formal fetal echocardiography. Each volume data set was acquired over 2 to 8 seconds and stored on the system's hard drive. Rendered images were subsequently processed to optimize translucency, smoothing, and orientation and cropped to reveal "surgeon's eye views" of clinically relevant anatomic structures. Qualitative comparison was made with conventional fetal echocardiography for each subject. Volume-rendered displays identified all major abnormalities but failed to identify small ventricular septal defects in 2 patients. Important planes and views not visualized during the actual scans were generated with minimal processing of rendered image displays. Volume-rendered displays tended to have slightly inferior image quality compared with conventional 2-dimensional images. Real-time 3-dimensional echocardiography with instantaneous volume-rendered displays of the fetal heart represents a new approach to fetal cardiac imaging with tremendous clinical potential.
International Nuclear Information System (INIS)
Martinez-Martinez, Sinuhe; Messai, Nadhir; Jeannot, Jean-Philippe; Nuzillard, Danielle
2015-01-01
The total instantaneous blockage (TIB) of an assembly in the core of a sodium-cooled fast reactor (SFR) is investigated. Such incident could appear as an abnormal rise in temperature on the assemblies neighbouring the blockage. Its detection relies on a dataset of temperature measurements of the assemblies making up the core of the French Phenix Nuclear Reactor. The data are provided by the French Commission of Atomic and Alternatives Energies (CEA). Here, two strategies are proposed depending on whether the sensor measurement of the suspected assembly is reliable or not. The proposed methodology implements a time-lagged feed-forward neural (TLFFN) Network in order to predict the one-step-ahead temperature of a given assembly. The incident is declared if the difference between the predicted process and the actual one exceeds a threshold. In these simulated conditions, the method is efficient to detect small gradients as expected in reality. - Highlights: • We study the total instantaneous blockage (TIB) of a sodium-cooled fast reactor. • The TIB symptom is simulated as an abrupt rise on temperature (0.1–1 °C/s). • The goal is to improve the early detection of the incident. • Two strategies laying on neural networks are proposed. • TIB is detected in 3 s for 1 °C/s and 18–21 s for 0.1 °C/s
Formosa, Danielle P; Sayers, Mark G L; Burkett, Brendan
2014-01-01
This study used both an instantaneous net drag force profile and a symmetry timing to evaluate the effect of the breathing action on stroke coordination. Twenty elite swimmers completed a total of six randomised front-crawl towing trials: (i) three breathing trials and (ii) three non-breathing trials. The net drag force was measured using an assisted towing device mounted upon a Kistler force platform, and this equipment towed the swimmer at a constant speed. The net drag force profile was used to create a stroke symmetry index for each swimming trial. Analysis using the symmetry indices identified that the majority of participants demonstrated an asymmetrical instantaneous net drag force stroke profile in both the breathing and non-breathing conditions, despite no significant differences in the time from finger-tip entry to finger-tip exit. Within the breathing condition, the faster swimmers compared to the slower swimmers demonstrated a lesser percentage of overlap between stroke phases on their breathing stroke side. During the non-breathing condition, the faster participants compared to the slower swimmers recorded a reduction in the percentage of overlap between stroke phases and less duration in the underwater stroke on their breathing stroke side. This study identified that the majority of participants demonstrated an asymmetrical net drag force profile within both conditions; however, asymmetry was less prevalent when examining with only the timing symmetry index.
Directory of Open Access Journals (Sweden)
Kara Shuttleworth
2017-05-01
Full Text Available BackgroundThe instantaneous wave-free ratio (iFR is a novel method to assess the ischemic potential of coronary artery stenoses. Clinical trial data have shown that iFR has acceptable diagnostic agreement with fractional flow reserve (FFR, the reference standard for the functional assessment of coronary stenoses. This study compares iFR measurements with FFR measurements in a real world, single-center setting.Methods and resultsInstantaneous wave-free ratio and FFR were measured in 50 coronary artery lesions in 42 patients, with FFR ≤ 0.8 classified as functionally significant. An iFR-only technique, using a treatment cut-off value, iFR ≤ 0.89, provided a classification agreement of 84% with FFR ≤ 0.80. Use of a hybrid iFR–FFR technique, incorporating FFR measurement for lesions within the iFR gray zone of 0.86–0.93, would improve classification agreement with FFR to 94%, with diagnosis achieved without the need for hyperemia in 57% patients.ConclusionThis study in a real-world setting demonstrated good classification agreement between iFR and FFR. Use of a hybrid iFR–FFR technique would achieve high diagnostic accuracy while minimizing adenosine use, compared with routine FFR.
Honarvar, Mohammad; Sahebjavaher, Ramin; Sinkus, Ralph; Rohling, Robert; Salcudean, Septimiu E
2013-12-01
In elasticity imaging, the shear modulus is obtained from measured tissue displacement data by solving an inverse problem based on the wave equation describing the tissue motion. In most inversion approaches, the wave equation is simplified using local homogeneity and incompressibility assumptions. This causes a loss of accuracy and therefore imaging artifacts in the resulting elasticity images. In this paper we present a new curl-based finite element method inversion technique that does not rely upon these simplifying assumptions. As done in previous research, we use the curl operator to eliminate the dilatational term in the wave equation, but we do not make the assumption of local homogeneity. We evaluate our approach using simulation data from a virtual tissue phantom assuming time harmonic motion and linear, isotropic, elastic behavior of the tissue. We show that our reconstruction results are superior to those obtained using previous curl-based methods with homogeneity assumption. We also show that with our approach, in the 2-D case, multi-frequency measurements provide better results than single-frequency measurements. Experimental results from magnetic resonance elastography of a CIRS elastography phantom confirm our simulation results and further demonstrate, in a quantitative and repeatable manner, that our method is accurate and robust.
Vidybida, Alexander
2015-09-01
We consider a class of spiking neuron models, defined by a set of conditions which are typical for basic threshold-type models like leaky integrate-and-fire, or binding neuron model and also for some artificial neurons. A neuron is fed with a point renewal process. A relation between the three probability density functions (PDF): (i) PDF of input interspike intervals ISIs, (ii) PDF of output interspike intervals of a neuron with a feedback and (iii) PDF for that same neuron without feedback is derived. This allows to calculate any one of the three PDFs provided the remaining two are given. Similar relation between corresponding means and variances is derived. The relations are checked exactly for the binding neuron model stimulated with Poisson stream.
Chen, Ya-Chen; Hsiao, Tzu-Chien
2016-10-06
Thoracoabdominal asynchrony is often adopted to discriminate respiratory diseases in clinics. Conventionally, Lissajous figure analysis is the most frequently used estimation of the phase difference in thoracoabdominal asynchrony. However, the temporal resolution of the produced results is low and the estimation error increases when the signals are not sinusoidal. Other previous studies have reported time-domain procedures with the use of band-pass filters for phase-angle estimation. Nevertheless, the band-pass filters need calibration for phase delay elimination. To improve the estimation, we propose a novel method (named as instantaneous phase difference) that is based on complementary ensemble empirical mode decomposition for estimating the instantaneous phase relation between measured thoracic wall movement and abdominal wall movement. To validate the proposed method, experiments on simulated time series and human-subject respiratory data with two breathing types (i.e., thoracic breathing and abdominal breathing) were conducted. Latest version of Lissajous figure analysis and automatic phase estimation procedure were compared. The simulation results show that the standard deviations of the proposed method were lower than those of two other conventional methods. The proposed method performed more accurately than the two conventional methods. For the human-subject respiratory data, the results of the proposed method are in line with those in the literature, and the correlation analysis result reveals that they were positively correlated with the results generated by the two conventional methods. Furthermore, the standard deviation of the proposed method was also the smallest. To summarize, this study proposes a novel method for estimating instantaneous phase differences. According to the findings from both the simulation and human-subject data, our approach was demonstrated to be effective. The method offers the following advantages: (1) improves the temporal
Directory of Open Access Journals (Sweden)
Jakob Winter
2018-03-01
Full Text Available Helminth infections of the gastrointestinal tract and lungs can lead to devastating economical losses to the pastoral based animal production. Farm animals can suffer from malnutrition, tissue damage, and blood loss resulting in impaired production traits and reproduction parameters. In Austria, pastures grazed by sheep, goats, and cattle overlap with the habitats of several species of wild cervids (roe deer, red deer, sika deer, and fallow deer and bovids (mouflon, chamois, and ibex, and transmission of parasites between different ruminant species seems likely. A complete and updated overview on the occurrence of helminths of domestic and wild ruminants in Austria is presented. Based on these data, intersections of the host spectrum of the determined parasites were depicted. The “liability index” was applied to identify the ruminant species, which most likely transmit parasites between each other. A degree for host specificity was calculated for each parasite species based on the average taxonomic distance of their host species. Of the 73 identified helminth species 42 were identified as generalists, and 14 transmission experiments supported the assumed broad host specificity for 14 generalists and 1 specialist helminth species. Overall, 61 helminths were found to infect more than one host species, and 4 were found in all 10 ruminant species investigated. From these analyses, it can be concluded that a number of helminth parasites of the gastrointestinal tract and the lungs are potentially transmitted between domestic and wild ruminants in Austria. For some parasites and host species, experimental evidence is in support for possible transmission, while for other such studies are lacking. Host preference of different genotypes of the same parasite species may have a confounding effect on the evaluation of cross-transmission, but so far this has not been evaluated systematically in helminths in Austria. Further studies focusing on
Parametric roll due to hull instantaneous volumetric changes and speed variations
DEFF Research Database (Denmark)
Vidic-Perunovic, Jelena; Jensen, Jørgen Juncher
2009-01-01
to e.g. added resistance has been accounted for in the model by the surge velocity. The ship roll motion due to a regular wave critical for parametric roll occurrence has been simulated, as well as the ship roll response in a severe stochastic sea. The present method has been compared with other...
DEFF Research Database (Denmark)
Thim, Troels; Götberg, Matthias; Fröbert, Ole
2017-01-01
OBJECTIVES: The aim of this study was to examine the level of agreement between acute instantaneous wave-free ratio (iFR) measured across nonculprit stenoses in patients with ST-segment elevation myocardial infarction (STEMI) and iFR measured at a staged follow-up procedure. BACKGROUND: Acute full...... revascularization of nonculprit stenoses in STEMI is debated and currently guided by angiography. Acute functional assessment of nonculprit stenoses may be considered. METHODS: Immediately after successful primary culprit intervention for STEMI, nonculprit coronary stenoses were evaluated with iFR and left...... untreated. Follow-up evaluation with iFR was performed at a later stage. iFR acute iFR was 0.89 (interquartile range: 0.82 to 0.94; n = 156), and median follow-up i...
Kim, Wangdo; Espanha, Margarida M; Veloso, António P; Araújo, Duarte; João, Filipa; Carrão, Luis; Kohles, Sean S
2013-03-27
Traditional locomotion studies emphasize an optimization of the desired movement trajectories while ignoring sensory feedback. We propose an information based theory that locomotion is neither triggered nor commanded but controlled. The basis for this control is the information derived from perceiving oneself in the world. Control therefore lies in the human-environment system. In order to test this hypothesis, we derived a mathematical foundation characterizing the energy that is required to perform a rotational twist, with small amplitude, of the instantaneous axes of the knee (IAK). We have found that the joint's perception of the ground reaction force may be replaced by the co-perception of muscle activation with appropriate intensities. This approach generated an accurate comparison with known joint forces and appears appropriate in so far as predicting the effect on the knee when it is free to twist about the IAK.
Haddad, Renato; Catharino, Rodrigo Ramos; Marques, Lygia Azevedo; Eberlin, Marcos Nogueira
2008-11-01
Perfume counterfeiting is an illegal worldwide practice that involves huge economic losses and potential consumer risk. EASI is a simple, easily performed and rapidly implemented desorption/ionization technique for ambient mass spectrometry (MS). Herein we demonstrate that EASI-MS allows nearly instantaneous perfume typification and counterfeit detection. Samples are simply sprayed onto a glass rod or paper surface and, after a few seconds of ambient drying, a profile of the most polar components of the perfume is acquired. These components provide unique and reproducible chemical signatures for authentic perfume samples. Counterfeiting is readily recognized since the exact set and relative proportions of the more polar chemicals, sometimes at low concentrations, are unknown or hard to reproduce by the counterfeiters and hence very distinct and variable EASI-MS profiles are observed for the counterfeit samples.
Melchinger, Albrecht E; Technow, Frank; Dhillon, Baldev S
2011-12-01
Recent progress in genotyping and doubled haploid (DH) techniques has created new opportunities for development of improved selection methods in numerous crops. Assuming a finite number of unlinked loci (ℓ) and a given total number (n) of individuals to be genotyped, we compared, by theory and simulations, three methods of marker-assisted selection (MAS) for gene stacking in DH lines derived from biparental crosses: (1) MAS for high values of the marker score (T, corresponding to the total number of target alleles) in the F(2) generation and subsequently among DH lines derived from the selected F(2) individual (Method 1), (2) MAS for augmented F(2) enrichment and subsequently for T among DH lines from the best carrier F(2) individual (Method 2), and (3) MAS for T among DH lines derived from the F(1) generation (Method 3). Our objectives were to (a) determine the optimum allocation of resources to the F(2) ([Formula: see text]) and DH generations [Formula: see text] for Methods 1 and 2 by simulations, (b) compare the efficiency of all three methods for gene stacking by simulations, and (c) develop theory to explain the general effect of selection on the segregation variance and interpret our simulation results. By theory, we proved that for smaller values of ℓ, the segregation variance of T among DH lines derived from F(2) individuals, selected for high values of T, can be much smaller than expected in the absence of selection. This explained our simulation results, showing that for Method 1, it is best to genotype more F(2) individuals than DH lines ([Formula: see text]), whereas under Method 2, the optimal ratio [Formula: see text] was close to 0.5. However, for ratios deviating moderately from the optimum, the mean [Formula: see text] of T in the finally selected DH line ([Formula: see text]) was hardly reduced. Method 3 had always the lowest mean [Formula: see text] of [Formula: see text] except for small numbers of loci (ℓ = 4) and is favorable only if
LINE-BY-LINE CALCULATION OF SPECTRA FROM DIATOMIC MOLECULES AND ATOMS ASSUMING A VOIGT LINE PROFILE
Whiting, E. E.
1994-01-01
This program predicts the spectra resulting from electronic transitions of diatomic molecules and atoms in local thermodynamic equilibrium. The program produces a spectrum by accounting for the contribution of each rotational and atomic line considered. The integrated intensity of each line is distributed in the spectrum by an approximate Voigt profile. The program can produce spectra for optically thin gases or for cases where simultaneous emission and absorption occurs. In addition, the program can compute the spectrum resulting from the absorption of incident radiation by a column of cold gas or the high-temperature, self-absorbed emission spectrum from a nonisothermal gas. The computed spectrum can be output directly or combined with a slit function and sensitivity calibration to predict the output of a grating spectrograph or a fixed wavelength radiometer. Specifically, the program has the capability to include the following features in any computations: (1) Parallel transitions, in which spin splitting and lambda doubling are ignored (ignoring spin splitting and/or lambda doubling means that the total multiple strength is assumed to reside in a single "effective" line), (2) Perpendicular transitions, in which spin splitting and lambda doubling are ignored, (3) Sigma Pi transitions, in which lambda doubling is ignored, (4) Atomic lines, (5) Option to terminate rotational line calculations when the molecule dissociates due to rotation, (6) Option to include the alternation of line intensities for homonuclear molecules, (7) Use of an approximate Voigt profile for the line shape, and (8) Radiative energy transport in a nonisothermal gas. The output options available in the program are: (1) Tabulation of the spontaneous emission spectrum (i.e., optically thin spectrum) for a 1.0 cm path length, (2) Tabulation of the "true" spectrum, which incorporates spontaneous emission, induced emission, absorption, and externally incident radiation through the equation of
Non-instantaneous gas recycling and chemical evolution in N-body disk galaxies
Czech Academy of Sciences Publication Activity Database
Jungwiert, Bruno; Carraro, G.; Dalla Vecchia, C.
2004-01-01
Roč. 289, 3-4 (2004), s. 441-444 ISSN 0004-640X. [From observations to self-consistent modelling of the ISM in galaxies. Porto, 03.09.2002-05.09.2002] R&D Projects: GA ČR GP202/01/D075 Institutional research plan: CEZ:AV0Z1003909 Keywords : N-body simulations * galaxy evolution * gas recycling Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.597, year: 2004
Lima, Rui; Wada, Shigeo; Takeda, Motohiro; Tsubota, Ken-ichi; Yamaguchi, Takami
2007-01-01
A confocal microparticle image velocimetry (micro-PIV) system was used to obtain detailed information on the velocity profiles for the flow of pure water (PW) and in vitro blood (haematocrit up to 17%) in a 100-microm-square microchannel. All the measurements were made in the middle plane of the microchannel at a constant flow rate and low Reynolds number (Re=0.025). The averaged ensemble velocity profiles were found to be markedly parabolic for all the working fluids studied. When comparing the instantaneous velocity profiles of the three fluids, our results indicated that the profile shape depended on the haematocrit. Our confocal micro-PIV measurements demonstrate that the root mean square (RMS) values increase with the haematocrit implying that it is important to consider the information provided by the instantaneous velocity fields, even at low Re. The present study also examines the potential effect of the RBCs on the accuracy of the instantaneous velocity measurements.
Using hidden Markov models to deal with availability bias on line transect surveys.
Borchers, D L; Zucchini, W; Heide-Jørgensen, M P; Cañadas, A; Langrock, R
2013-09-01
We develop estimators for line transect surveys of animals that are stochastically unavailable for detection while within detection range. The detection process is formulated as a hidden Markov model with a binary state-dependent observation model that depends on both perpendicular and forward distances. This provides a parametric method of dealing with availability bias when estimates of availability process parameters are available even if series of availability events themselves are not. We apply the estimators to an aerial and a shipboard survey of whales, and investigate their properties by simulation. They are shown to be more general and more flexible than existing estimators based on parametric models of the availability process. We also find that methods using availability correction factors can be very biased when surveys are not close to being instantaneous, as can estimators that assume temporal independence in availability when there is temporal dependence. © 2013, The International Biometric Society.
DEFF Research Database (Denmark)
Kim, Hyosung; Blaabjerg, Frede; Bak-Jensen, Birgitte
2002-01-01
This paper proposes a novel power compensation algorithm in three-phase four-wire systems by using p-q-r theory. The p-q-r theory is compared with two previous instantaneous power theories, p-q theory and cross-vector theory. The p-q-r theory provides two-degrees of freedom to control the system...... currents by only compensating the instantaneous imaginary power without using any energy storage element. The definition of powers maintains power conservation, and agrees well with the general understanding of power. Simulation results show the superiority of p-q-r theory both in definition...
Mass conservation for instantaneous sources in FEM3 simulations of material dispersion
International Nuclear Information System (INIS)
Rodean, H.C.
1987-11-01
This report presents the results of a systematic study in which it is shown that the numerical integration errors in determining material mass content are negligible; the material phase-change model by itself is not a cause of material mass variation; and a linear relation between fractional mass change and fractional density change at the source center for given mesh and source geometries exists over a range of values from 10 -5 to 10 -1 . This suggests that the omission of the ∂ rho/∂t term from the mass conservation equation is the cause of the observed non-conservation of mass by FEM3. It is shown that these mass variations can be minimized by minimizing the initial density gradients in the source region. 5 refs., 18 figs., 4 tabs
Mass conservation for instantaneous sources in FEM3 simulations of material dispersion
Energy Technology Data Exchange (ETDEWEB)
Rodean, H.C.
1987-11-01
This report presents the results of a systematic study in which it is shown that the numerical integration errors in determining material mass content are negligible; the material phase-change model by itself is not a cause of material mass variation; and a linear relation between fractional mass change and fractional density change at the source center for given mesh and source geometries exists over a range of values from 10/sup -5/ to 10/sup -1/. This suggests that the omission of the par. delta rho/par. deltat term from the mass conservation equation is the cause of the observed non-conservation of mass by FEM3. It is shown that these mass variations can be minimized by minimizing the initial density gradients in the source region. 5 refs., 18 figs., 4 tabs.
Near-instantaneous Bayesian inversion and uncertainty estimation: Sampling from the prior
Valentine, A. P.; Kaeufl, P.; De Wit, R. W. L.; Trampert, J.
2015-12-01
Ideally, uncertainty estimation should be treated as an intrinsic part of solving an inverse problem, and techniques such as Markov Chain Monte Carlo (MCMC) inversion provide a route to achieving this. However, these approaches involve `posterior sampling', and the (often significant) computational investment is entirely targeted towards one specific dataset. In those cases where similar inverse problems must be solved repeatedly (perhaps for multiple locations on the Earth's surface), or where results must be obtained within very limited timescales (e.g. earthquake early warning), this presents a barrier to use of methods such as MCMC. In such cases, approaches based on `prior sampling' may be preferable. This separates the computationally-expensive step (generating samples in the joint data-model space) from the dataset-specific inversion stage, and permits one set of samples to be recycled for many different datasets. The essential difference between prior and posterior sampling is the stage at which the solution is conditioned on a given dataset. We show that prior sampling can be implemented effectively, using learning algorithms to assimilate and apply information on the mapping between data and model spaces. We illustrate that this can be successfully applied in a range of geophysical problems. By comparing solutions based on prior sampling to those obtained via posterior sampling, we show that results are compatible---although the less focussed nature of prior sampling typically leads to more conservative uncertainty estimates in any given case. Nevertheless, for certain classes of problems, prior sampling appears to be a promising way forward.
Zhang, Jianhua; Yin, Zhong; Wang, Rubin
2017-01-01
The identification of the temporal variations in human operator cognitive task-load (CTL) is crucial for preventing possible accidents in human-machine collaborative systems. Recent literature has shown that the change of discrete CTL level during human-machine system operations can be objectively recognized using neurophysiological data and supervised learning technique. The objective of this work is to design subject-specific multi-class CTL classifier to reveal the complex unknown relationship between the operator's task performance and neurophysiological features by combining target class labeling, physiological feature reduction and selection, and ensemble classification techniques. The psychophysiological data acquisition experiments were performed under multiple human-machine process control tasks. Four or five target classes of CTL were determined by using a Gaussian mixture model and three human performance variables. By using Laplacian eigenmap, a few salient EEG features were extracted, and heart rates were used as the input features of the CTL classifier. Then, multiple support vector machines were aggregated via majority voting to create an ensemble classifier for recognizing the CTL classes. Finally, the obtained CTL classification results were compared with those of several existing methods. The results showed that the proposed methods are capable of deriving a reasonable number of target classes and low-dimensional optimal EEG features for individual human operator subjects.
Studying the instantaneous velocity field in gas-sheared liquid films in a horizontal duct
Vasques, Joao; Tokarev, Mikhail; Cherdantsev, Andrey; Hann, David; Hewakandamby, Buddhika; Azzopardi, Barry
2016-11-01
In annular flow, the experimental validation of the basic assumptions on the liquid velocity profile is vital for developing theoretical models of the flow. However, the study of local velocity of liquid in gas-sheared films has proven to be a challenging task due to the highly curved and disturbed moving interface of the phases, small scale of the area of interrogation, high velocity gradients and irregular character of the flow. This study reports on different optical configurations and interface-tracking methods employed in a horizontal duct in order to obtain high-resolution particle image velocimetry (PIV) data in such types of complex flows. The experimental envelope includes successful measurements in 2D and 3D waves regimes, up to the disturbance wave regime. Preliminary data show the presence of complex structures in the liquid phase, which includes re-circulation areas below the liquid interface due to the gas-shearing action, together with non-uniform transverse movements of the liquid phase close to the wall due to the presence of 3D waves at the interface. With the aid of the moving interface-tracking, PIV, time-resolved particle-tracking velocimetry and vorticity measurements were performed.
International Nuclear Information System (INIS)
Fairclough, M.P.; Goodill, D.R.; Tymons, B.J.
1985-03-01
This report describes an assessment of conditioned radioactive waste arisings from existing and committed nuclear installations, DOE Revised Scheme 1, and from an assumed nuclear power generation scenario, DOE Revised Scheme 3, representing a moderate growth in nuclear generation. Radioactive waste arise from 3 main groups of installations and activities: i. existing and committed commercial reactors; ii. fuel reprocessing plants, iii. research, industrial and medical activities. Stage 2 decommissioning wastes are considered together with WAGR decommissioning and the 1983 Sea Dump Consignment. The study uses the SIMULATION 2 code which models waste material flows through a system of waste treatment and packaging to disposal. With a knowledge of the accumulations and average production rates of untreated wastes and their isotopic compositions (or total activities), the rates at which conditioned wastes become available for transportation and disposal are calculated, with specific activity levels. The data for the inventory calculations have previously been documented. Some recent revisions and assumptions concerning future operation of nuclear facilities are presented in this report. (author)
Improved Analytical Model of a Permanent-Magnet Brushless DC Motor
Kumar, P.; Bauer, P.
2008-01-01
In this paper, we develop a comprehensive model of a permanent-magnet brushless DC (BLDC) motor. An analytical model for determining instantaneous air-gap field density is developed. This instantaneous field distribution can be further used to determine the cogging torque, induced back electromotive
Directory of Open Access Journals (Sweden)
S. V. Bordusov
2010-01-01
Full Text Available The paper presents results of investigations pertaining to the possibility of regulating instantaneous power output in a magnetron of M-105 (M-112-type by changing the capacity value of a capacitor in structure diagram for doubling voltage of high-voltage power supply on the basis of a step-up transformer operating in the saturation regime.
Raef, Abdelmoneam; Totten, Matthew; Vohs, Andrew; Linares, Aria
2017-12-01
Thin hydrocarbon reservoir facies pose resolution challenges and waveform-signature opportunities in seismic reservoir characterization and prospect identification. In this study, we present a case study, where instantaneous frequency variation in response to a thin hydrocarbon pay zone is analyzed and integrated with other independent information to explain drilling results and optimize future drilling decisions. In Morrison NE Field, some wells with poor economics have resulted from well-placement incognizant of reservoir heterogeneities. The study area in Clark County, Kanas, USA, has been covered by a surface 3D seismic reflection survey in 2010. The target horizon is the Viola limestone, which continues to produce from 7 of the 12 wells drilled within the survey area. Seismic attributes extraction and analyses were conducted with emphasis on instantaneous attributes and amplitude anomalies to better understand and predict reservoir heterogeneities and their control on hydrocarbon entrapment settings. We have identified a higher instantaneous frequency, lower amplitude seismic facies that is in good agreement with distinct lithofacies that exhibit better (higher porosity) reservoir properties, as inferred from well-log analysis and petrographic inspection of well cuttings. This study presents a pre-drilling, data-driven approach of identifying sub-resolution reservoir seismic facies in a carbonate formation. This workflow will assist in placing new development wells in other locations within the area. Our low amplitude high instantaneous frequency seismic reservoir facies have been corroborated by findings based on well logs, petrographic analysis data, and drilling results.
Hsue, Bih-Jen; Miller, Freeman; Su, Fong-Chin
2009-04-01
As a companion research subsequent to analyzing displacement of center of mass (COM) and center of pressure (COP) in Part I, the purposes of this study were to quantify dynamic stability using magnitudes and patterns of instantaneous velocity and acceleration of COM and COP of the children with cerebral palsy (CP) during walking, and compare the data with those of the typically developing (TD) children. The instantaneous velocity and acceleration of COM and COP were acquired by calculating the first and second derivatives of displacement data presented in Part I. Velocity and acceleration of COM and COP were normalized by each participant's leg length to eliminate the influence of individual's stature. The results indicate that the preferred walking speed is significantly higher in TD groups than hemiplegic group (Hemi) and diplegic group (Di). The peak values of instantaneous velocity and acceleration of COM in vertical, medio-lateral (ML) and antero-posterior (AP) directions and velocity and acceleration of COP in ML direction were significantly higher in Di group than TD group. Both CP groups showed great variability in COM and COP parameters. Therefore, although Di group demonstrated higher peak values than Hemi group, the only significant difference between two groups was instantaneous COP velocity in ML direction. The findings of this study suggest that this assessment may be of value for research or clinical evaluation of dynamic balance dysfunction during walking and provide comparisons and insights for specific treatments or surgical interventions for the children with CP.
National Oceanic and Atmospheric Administration, Department of Commerce — This data file is comprised of instantaneous values of the geomagnetic components D, H, and Z or X, Y, and Z at 2.5-minute intervals. These values were derived from...
Directory of Open Access Journals (Sweden)
Nabeel Ali Khan
2017-02-01
Full Text Available The instantaneous frequency (IF of a non-stationary signal is usually estimated from a time-frequency distribution (TFD. The IF of heart rate variability (HRV is an important parameter because the power in a frequency band around the IF can be used for the interpretation and analysis of the respiratory rate but also for a more accurate analysis of heart rate (HR signals. In this study, we compare the performance of five states of the art kernel-based time-frequency distributions (TFDs in terms of their ability to accurately estimate the IF of HR signals. The selected TFDs include three widely used fixed kernel methods: the modified B distribution, the S-method and the spectrogram; and two adaptive kernel methods: the adaptive optimal kernel TFD and the recently developed adaptive directional TFD. The IF of the respiratory signal, which is usually easier to estimate as the respiratory signal is a mono-component with small amplitude variations with time, is used as a reference to examine the accuracy of the HRV IF estimates. Experimental results indicate that the most reliable estimates are obtained using the adaptive directional TFD in comparison to other commonly used methods such as the adaptive optimal kernel TFD and the modified B distribution.
Aguiar, Anna Carolina Fornero; Gücker, Björn; Brauns, Mario; Hille, Sandra; Boëchat, Iola Gonçalves
2015-07-01
The aim of this study was to assess land use effects on the density, biomass, and instantaneous secondary production (IP) of benthic invertebrates in a fifth-order tropical river. Invertebrates were sampled at 11 stations along the Rio das Mortes (upper Rio Grande, Southeast Brazil) in the dry and the rainy season 2010/2011. Invertebrates were counted, determined, and measured to estimate their density, biomass, and IP. Water chemical characteristics, sediment heterogeneity, and habitat structural integrity were assessed in parallel. Total invertebrate density, biomass, and IP were higher in the dry season than those in the rainy season, but did not differ significantly among sampling stations along the river. However, taxon-specific density, biomass, and IP differed similarly among sampling stations along the river and between seasons, suggesting that these metrics had the same bioindication potential. Variability in density, biomass, and IP was mainly explained by seasonality and the percentage of sandy sediment in the riverbed, and not directly by urban or agricultural land use. Our results suggest that the consistently high degradation status of the river, observed from its headwaters to mouth, weakened the response of the invertebrate community to specific land use impacts, so that only local habitat characteristics and seasonality exerted effects.
Beresford, D V; Sutcliffe, J F
2010-06-01
The instantaneous rate of population increase was used to assess the ability of attractive targets coated with permethrin to control stable fly populations on 3 dairy farms in south central Ontario, Canada. Two attractive targets were deployed over 10 wk in 2001 at each of 6 dairy farms. Three farms were outfitted with 2 untreated targets and 3 were outfitted with 2 targets treated with permethrin [Ectiban-impregnated Coroplast (Ectiban: Schering-Plough Canada Inc., Pointe-Claire, Québec, Canada; Coroplast: Great Pacific Enterprises Inc., Granby, Québec, Canada)]. Population growth rate was measured in terms of degree-days above a 10 degrees C developmental threshold (r(DD10)). The r(DD10) at the 3 treated dairy farms were significantly lower than r(DD10) at the 3 neighboring untreated dairy farms (mean r(DD10): treated=0.0088, untreated=0.013), but not in the previous year when targets were not installed (mean r(DD10): treated=0.012, untreated=0.015). This supports a long-term approach to management that lowers population growth rates in those regions where stable fly numbers increase exponentially from spring until winter, by shortening the period of economic impact of this pest. 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Bobbitt, Percy J.; Maglieri, Domenic J.; Banks, Daniel W.; Fuchs, Aaron W.
2011-01-01
Wedge and conical shaped probes for the measurement of free-stream flow quantities at supersonic speeds have been tested in both wind tunnel and flight. These probes have improved capabilities over similar ones used in the past. Through the use of miniature pressure sensors, that are located inside the probes, they are able to provide instantaneous measurements of a time-varying environment. Detailed herein are the results of the tests in NASA Langley Researcher Center s Unitary Plan Wind Tunnel (UPWT) at Mach numbers of 1.6, 1.8 and 2.0, as well as flight tests carried out at the NASA Dryden Flight Research Center (DFRC) on its F-15 aircraft up to Mach numbers of 1.9. In the flight tests the probes were attached to a fixture on the underside of the F-15 fuselage. Problems controlling the velocity of the flow through the conical probe, required for accurate temperature measurements, are noted, as well as some calibration problems of the miniature pressure sensors that impact the accuracy of the measurements.
Karimzadeh, Foroozan; Boostani, Reza; Seraj, Esmaeil; Sameni, Reza
2018-02-01
During the past decades, a great body of research has been devoted to automatic sleep stage scoring using the electroencephalogram (EEG). However, the results are not yet satisfactory to be used as a standard procedure in clinical studies. In this study, using recent developments in robust EEG phase extraction, a novel set of EEG-based features containing the Shannon entropy of the instantaneous analytical form envelope and frequencies of the EEG are proposed for sleep stage scoring. The proposed feature set is used to construct a distributed decision-tree classifier, with binary K-nearest neighbor classifiers at each decision node. The decision-tree structure is designed by brute-force-search over various combinations of the proposed feature set. The performance of the proposed approach is evaluated over two available sleep EEG data sets acquired using single-channel EEG. The first set contains 20 healthy young subjects containing equal number of male and female, and the second one has been acquired from 140 adult subjects from both genders, with sleep disorder. The performance of the proposed method is tested versus state-of-the-art classifiers. The results demonstrate that the proposed method, resulted in overall accuracies of 88.97% and 83.17% over the two data sets, respectively. Considering the high performance and simplicity of the proposed scheme, the method can be of interest for clinical sleep disorder studies.
Directory of Open Access Journals (Sweden)
Kelly N. Salb
2016-01-01
Full Text Available Ankle instantaneous axis of rotation (IAR measurements represent a more complete parameter for characterizing joint motion. However, few studies have implemented this measurement to study normal, injured, or pathological foot ankle biomechanics. A novel testing protocol was developed to simulate aspects of in vivo foot ankle mechanics during mid-stance gait in a human cadaveric specimen. A lower leg was mounted in a robotic testing platform with the tibia upright and foot flat on the baseplate. Axial tibia loads (ATLs were controlled as a function of a vertical ground reaction force (vGRF set at half body weight (356 N and a 50% vGRF (178 N Achilles tendon load. Two specimens were repetitively loaded over 10 degrees of dorsiflexion and 20 degrees of plantar flexion. Platform axes were controlled within 2 microns and 0.008 degrees resulting in ATL measurements within ±2 N of target conditions. Mean ATLs and IAR values were not significantly different between cycles of motion, but IAR values were significantly different between dorsiflexion and plantar flexion. A linear regression analysis showed no significant differences between slopes of plantar flexion paths. The customized robotic platform and advanced testing protocol produced repeatable and accurate measurements of the IAR, useful for assessing foot ankle biomechanics under different loading scenarios and foot conditions.
Sanabria-DeLong, Naomi; Crosby, Alfred J.; Tew, Gregory N.
2014-01-01
Poly(lactide) – block – poly(ethylene oxide) – block – poly(lactide) [PLA-PEO-PLA] triblock copolymers are known to form physical hydrogels in water, due to the polymer's amphiphilicity. Their mechanical properties, biocompatibility, and biodegradability have made them attractive for use as soft tissue scaffolds. However, the network junction points are not covalently crosslinked and in a highly aqueous environment these hydrogels adsorb more water, transform from gel to sol, and lose the designed mechanical properties. In this report, a hydrogel was formed by using a novel two step approach. In the first step end-functionalized PLA-PEOPLA triblock was self-assembled into a physical hydrogel through hydrophobic micelle network junctions, and then, in the second step, this self-assembled physical network structure was locked into place by photocrosslinking the terminal acrylate groups. In contrast to physical hydrogels, the photocrosslinked gels remained intact in phosphate buffered solution at body temperature. The swelling, degradation, and mechanical properties were characterized and demonstrated extended degradation time (~ 65 days), exponential decrease in modulus with degradation time, and tunable shear modulus (1.6 – 133 kPa) by varying concentration. We also discuss the various constitutive relationships (Hookean, Neo-Hookean, and Mooney-Rivlin) that can be used to describe the stress-strain behavior of these hydrogels. The chosen model and assumptions used for data fitting influences the obtained modulus values by as much as a factor of 3.5, demonstrating the importance of clearly stating one's data fitting parameters so that accurate comparisons can be made within the literature. PMID:18817440
Compact instantaneous water heater
Energy Technology Data Exchange (ETDEWEB)
Azevedo, Jorge G.W.; Machado, Antonio R.; Ferraz, Andre D.; Rocha, Ivan C.C. da; Konishi, Ricardo [Companhia de Gas de Santa Catarina (SCGAS), Florianopolis, SC (Brazil); Lehmkuhl, Willian A.; Francisco Jr, Roberto W.; Hatanaka, Ricardo L.; Pereira, Fernando M.; Oliveira, Amir A.M. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)
2012-07-01
This paper presents an experimental study of combustion in an inert porous medium in a liquid heating device application. This project aims to increase efficiency in the application of natural gas in residential and commercial sectors with the use of advanced combustion and heat transfer. The goal is to facilitate the development of a high performance compact water heater allowing hot water supply for up to two simultaneous showers. The experiment consists in a cylindrical porous burner with an integrated annular water heat exchanger. The reactants were injected radially into the burner and the flame stabilizes within the porous matrix. The water circulates in a coiled pipe positioned at the center of the burner. This configuration allows for heat transfer by conduction and radiation from the solid matrix to the heat exchanger. This article presented preliminary experimental results of a new water heater based on an annular porous burner. The range of equivalence ratios tested varied from 0.65 to 0.8. The power range was varied from 3 to 5 kW. Increasing the equivalence ratio or decreasing the total power input of the burner resulted in increased thermal efficiencies of the water heater. Thermal efficiencies varying from 60 to 92% were obtained. The condition for the goal of a comfortable bath was 20 deg C for 8-12 L/min. This preliminary prototype has achieved water temperature of 11deg C for 5 L/min. Further optimizations will be necessary in order to achieve intense heating with high thermal efficiency. (author)
Dynamics of gastropod infection by first-stage larvae of protostrongylid nematodes--a model.
Rezác, P; Kindlmann, P; Dostálková, I; Holasová, E
1993-12-01
For the description of the dynamics of snail infection by the 1st-stage larvae of protostrongylid nematodes, Skorping (1988) used the miracidia-snail model (Anderson, 1978). Here it is shown that, in contrast to miracidia, in protostrongylids the instantaneous rate of infection, alpha, is strongly dependent on the experimental design (factors like host size and size of the experimental arena). With respect to this, Anderson's model is modified by incorporation of the experimental design. The parameter alpha in its new sense as the rate of penetration (probability that the infective larva will penetrate into the host during a time unit) is shown to remain dependent, although much less so, on the experimental design. Only the inclusion of the assumed effect of mucus, which decreases the rate of penetration, yields a parameter alpha 0 (the initial rate of penetration), which is completely independent of the design of the experiment, is species-specific, and also gives the best fit to the empirical data. As the above-mentioned factors can strongly influence the value of the instantaneous rate of infection in the laboratory experiments, alpha 0 is more suitable as a measure of either the larval infectivity for the snail or snail susceptibility to infection by the protostrongylid larvae.
On the necessary complexity of modeling of the Polar Mesosphere Summer Echo Overshoot Effect
Biebricher, Alexander; Havnes, Ove; Bast, Radovan
2012-06-01
Recent numerical studies of the Polar Mesosphere Summer Echo (PMSE) Overshoot Effect predict the basic shape of the Overshoot Characteristic Curve (OCC) to undergo dramatic changes as the frequency of the radar decreases. Principally, this may render earlier modeling, which assumed near-instantaneous diffusion of electrons and ions, moot and exacerbate algebraic analysis of OCC obtained in the future with, e.g. the MORRO-radar (56 MHz) and a synchronized radio wave emitter, both at or near the European Incoherent Scatter (EISCAT) Scientific Association's site in Ramfjordmoen near Tromsø, Norway. Since, however, by far the most observational results on the PMSE Overshoot Effect have been assembled with the help of the Very High Frequency (VHF, 224 MHz) radar and the an Ultra High Frequency (UHF, 929 MHz) radar, both at the EISCAT site, we examine more closely whether near-instantaneous diffusion is a valid assumption for these particular frequencies. We show that, indeed, the earlier less complex and analytically more accessible model can still be considered sufficient for most, if not all, existing experimental data.
Convenient models of the atmosphere: optics and solar radiation
Alexander, Ginsburg; Victor, Frolkis; Irina, Melnikova; Sergey, Novikov; Dmitriy, Samulenkov; Maxim, Sapunov
2017-11-01
Simple optical models of clear and cloudy atmosphere are proposed. Four versions of atmospheric aerosols content are considered: a complete lack of aerosols in the atmosphere, low background concentration (500 cm-3), high concentrations (2000 cm-3) and very high content of particles (5000 cm-3). In a cloud scenario, the model of external mixture is assumed. The values of optical thickness and single scattering albedo for 13 wavelengths are calculated in the short wavelength range of 0.28-0.90 µm, with regard to the molecular absorption bands, that is simulated with triangle function. A comparison of the proposed optical parameters with results of various measurements and retrieval (lidar measurement, sampling, processing radiation measurements) is presented. For a cloudy atmosphere models of single-layer and two-layer atmosphere are proposed. It is found that cloud optical parameters with assuming the "external mixture" agrees with retrieved values from airborne observations. The results of calculating hemispherical fluxes of the reflected and transmitted solar radiation and the radiative divergence are obtained with the Delta-Eddington approach. The calculation is done for surface albedo values of 0, 0.5, 0.9 and for spectral values of the sandy surface. Four values of solar zenith angle: 0°, 30°, 40° and 60° are taken. The obtained values are compared with data of radiative airborne observations. Estimating the local instantaneous radiative forcing of atmospheric aerosols and clouds for considered models is presented together with the heating rate.
Modeling the kinetics of essential oil hydrodistillation from plant materials
Directory of Open Access Journals (Sweden)
Milojević Svetomir Ž.
2013-01-01
Full Text Available The present work deals with modeling the kinetics of essential oils extraction from plant materials by water and steam distillation. The experimental data were obtained by studying the hydrodistillation kinetics of essential oil from juniper berries. The literature data on the kinetics of essential oils hydrodistillation from different plant materials were also included into the modeling. A physical model based on simultaneous washing and diffusion of essential oil from plant materials were developed to describe the kinetics of essential oils hydrodistillation, and two other simpler models were derived from this physical model assuming either instantaneous washing followed by diffusion or diffusion with no washing (i.e. the first-order kinetics. The main goal was to compare these models and suggest the optimum ones for water and steam distillation and for different plant materials. All three models described well the experimental kinetic data on water distillation irrespective of the type of distillation equipment and its scale, the type of plant materials and the operational conditions. The most applicable one is the model involving simultaneous washing and diffusion of the essential oil. However, this model was generally inapplicable for steam distillation of essential oils, except for juniper berries. For this hydrodistillation technique, the pseudo first-order model was shown to be the best one. In a few cases, a variation of the essential oil yield with time was observed to be sigmoidal and was modeled by the Boltzmann sigmoid function.
Zhang, Qingxue; Zhou, Dian; Zeng, Xuan
2017-11-01
long-term wearable instantaneous heart rate (IHR) monitoring is essential to enable pervasive heart health and fitness management. In this paper, a novel framework is proposed to robustly estimate the IHR from electrocardiogram (ECG) signals corrupted by large amounts of daily motion artifacts, which are one of the major impediments against the long-term IHR monitoring. the corrupted ECG signals are first projected to a high-dimensional phase space, where the constructed phase portraits of heartbeats are of many new geometrical properties and are expected to be powerful patterns more immune to the motion artifacts. Afterwards, a multiview dynamic time warping approach is applied on the constructed phase portraits, to effectively capture motion artifacts-induced inconsistencies and reveal heartbeats-related consistencies from corrupted signals. Finally, the phase portraits of heartbeats in the multidimensional phase space can be identified, and then, the IHR estimates are achieved. the proposed framework is evaluated on a wrist-ECG dataset acquired by a semicustomized platform and also a public ECG dataset. With a signal-to-noise ratio as low as -9 dB, the mean absolute error and root mean square error of the estimated IHR are 2.5 beats per minute (BPM) and 7.0 BPM, respectively. these results demonstrate that our framework can effectively identify the heartbeats from ECG signals continuously corrupted by intense and random motion artifacts and estimate the IHR. the proposed framework greatly outperforms previously reported approaches and is expected to contribute to long-term IHR monitoring. long-term wearable instantaneous heart rate (IHR) monitoring is essential to enable pervasive heart health and fitness management. In this paper, a novel framework is proposed to robustly estimate the IHR from electrocardiogram (ECG) signals corrupted by large amounts of daily motion artifacts, which are one of the major impediments against the long-term IHR monitoring. the
Directory of Open Access Journals (Sweden)
Jacek Paziewski
2018-01-01
Full Text Available This study addresses the potential contribution of the first pair of Galileo FOC satellites sent into incorrect highly eccentric orbits for geodetic and surveying applications. We began with an analysis of the carrier to noise density ratio and the stochastic properties of GNSS measurements. The investigations revealed that the signal power of E14 & E18 satellites is higher than for regular Galileo satellites, what is related to their lower altitude over the experiment area. With regard to the noise of the observables, there are no significant differences between all Galileo satellites. Furthermore, the study confirmed that the precision of Galileo data is higher than that of GPS, especially in the case of code measurements. Next analysis considered selected domains of precise instantaneous medium-range positioning: ambiguity resolution and coordinate accuracy as well as observable residuals. On the basis of test solutions, with and without E14 & E18 data, we found that these satellites did not noticeably influence the ambiguity resolution process. The discrepancy in ambiguity success rate between test solutions did not exceed 2%. The differences between standard deviations of the fixed coordinates did not exceed 1 mm for horizontal components. The standard deviation of the L1/E1 phase residuals, corresponding to regular GPS and Galileo, and E14 & E18 satellite signals, was at a comparable level, in the range of 6.5–8.7 mm. The study revealed that the Galileo satellites with incorrect orbits were fully usable in most geodetic, surveying and many other post-processed applications and may be beneficial especially for positioning during obstructed visibility of satellites. This claim holds true when providing precise ephemeris of satellites.
Wang, Shibin; Chen, Xuefeng; Selesnick, Ivan W.; Guo, Yanjie; Tong, Chaowei; Zhang, Xingwu
2018-02-01
Synchrosqueezing transform (SST) can effectively improve the readability of the time-frequency (TF) representation (TFR) of nonstationary signals composed of multiple components with slow varying instantaneous frequency (IF). However, for signals composed of multiple components with fast varying IF, SST still suffers from TF blurs. In this paper, we introduce a time-frequency analysis (TFA) method called matching synchrosqueezing transform (MSST) that achieves a highly concentrated TF representation comparable to the standard TF reassignment methods (STFRM), even for signals with fast varying IF, and furthermore, MSST retains the reconstruction benefit of SST. MSST captures the philosophy of STFRM to simultaneously consider time and frequency variables, and incorporates three estimators (i.e., the IF estimator, the group delay estimator, and a chirp-rate estimator) into a comprehensive and accurate IF estimator. In this paper, we first introduce the motivation of MSST with three heuristic examples. Then we introduce a precise mathematical definition of a class of chirp-like intrinsic-mode-type functions that locally can be viewed as a sum of a reasonably small number of approximate chirp signals, and we prove that MSST does indeed succeed in estimating chirp-rate and IF of arbitrary functions in this class and succeed in decomposing these functions. Furthermore, we describe an efficient numerical algorithm for the practical implementation of the MSST, and we provide an adaptive IF extraction method for MSST reconstruction. Finally, we verify the effectiveness of the MSST in practical applications for machine fault diagnosis, including gearbox fault diagnosis for a wind turbine in variable speed conditions and rotor rub-impact fault diagnosis for a dual-rotor turbofan engine.
Dixon, Kevin W.; Krueger, Gretchen M.; Rojas, Victoria A.; Hubbard, David C.
1989-09-01
Helmet mounted displays provide required field of regard, out of the cockpit visual imagery for tactical training while maintaining acceptable luminance and resolution levels. An important consideration for visual system designers is the horizontal and vertical dimensions of the instantaneous field of view. This study investigated the effect of various instantaneous field of view sizes on the performance of low level flight and 30 degree manual dive bomb tasks. An in-simulator transfer of training design allowed pilots to be trained in an instantaneous field of view condition and transferred to a wide FOV condition for testing. The selected instantaneous field of view sizes cover the range of current and proposed helmet mounted displays. The field of view sizes used were 127° H x 67° V, 140° H x 80° V, 160° H x 80° V, and 180° H x 80° V. The 300° H x 150° V size provided a full field of view control condition. An A-10 dodecahedron simulator configured with a color light valve display, computer generated imagery, and a Polhemus magnetic head tracker provided the cockpit and display apparatus. The Polhemus magnetic head tracker allowed the electronically masked field of view sizes to be moved on the seven window display of the dodecahedron. The dependent measures were: 1) Number of trials to reach criterion for low level flight tasks and dive bombs, 2) Performance measures of the low level flight route, 3) Performance measures of the dive bombing task, and 4) Subjective questionnaire data. Thirty male instructor pilots from Williams AFB, Arizona served as subjects for the study. The results revealed significant field of view effects for the number of trials required to reach criterion in the two smallest FOV conditions for right 180° turns and dive bomb training. The data also revealed pilots performed closer to the desired pitch angle for all but the two smallest conditions. The questionnaire data revealed that pilots felt their performance was degraded
International Nuclear Information System (INIS)
Kaigawa, R.; Uesugi, T.; Yoshida, T.; Merdes, S.; Klenk, R.
2009-01-01
CuInSe 2 (CIS) films are successfully prepared by means of non-vacuum, instantaneous, direct synthesis from elemental In, Cu, Se particles precursor films without prior synthesis of CIS nanoparticle precursors and without selenization with H 2 Se or Se vapor. Our precursor films were prepared on metal substrates by spraying the solvent with added elemental In, Cu, and Se particles. Precursor films were instantaneously sintered using a spot welding machine. When the electric power was fixed to 0.6 kVA, elemental In, Cu, or Se peaks were not observed and only peaks of CIS are observed by X-ray diffraction (XRD) on the film sintered for 7/8 s. We can observe XRD peaks indicative of the chalcopyrite-type structure, such as (101), (103) and (211) diffraction peaks. We conclude that the synthesized CIS crystals have chalcopyrite-type structure with high crystallinity
2010-07-01
... direct responsibility for the costs of preparing and transporting my mobile home? 302-10.206 Section 302... ALLOWANCES TRANSPORTATION AND STORAGE OF PROPERTY 10-ALLOWANCES FOR TRANSPORTATION OF MOBILE HOMES AND BOATS... responsibility for the costs of preparing and transporting my mobile home? Yes, your agency may assume direct...
Directory of Open Access Journals (Sweden)
Octavian PREOTU
2011-06-01
Full Text Available The paper analyzes, in parallel, common aspects and differences in the behavior of classical configuration versus canard configuration aircraft in the presence of vertical gusts, assuming the hypothesis of an elastic fuselage. The effects of the main constructional dimensions of the horizontal empennage on lift cancelling and horizontal empennage control are being analyzed
Directory of Open Access Journals (Sweden)
Yu Zheng
2016-01-01
Full Text Available The therapeutic effects of acupuncture in decreasing blood pressure are ambiguous and underlying acupuncture in hypertension treatment has not been investigated. Our objective was to observe the change of quality of life and compare the differences in brain functional connectivity by investigating instantaneous and short-term acupuncture treatment in essential hypertension patients. A total of 30 patients were randomly divided into the LR3 group and sham acupoint group. Subjects received resting-state fMRI among preacupuncture, postinstantaneous, and short-term acupuncture treatment in two groups. Hypothalamus was selected as the seed point to analyze the changes in connectivity. We found three kinds of results: (1 There was statistical difference in systolic blood pressure in LR3 group after the short-term treatment and before acupuncture. (2 Compared with sham acupoint, acupuncture at LR3 instantaneous effects in the functional connectivity with seed points was more concentrated in the frontal lobe. (3 Compared with instantaneous effects, acupuncture LR3 short-term effects in the functional connectivity with seed points had more regions in frontal lobe, cerebellum, and insula. These brain areas constituted a neural network structure with specific functions that could explain the mechanism of therapy in hypertension patients by LR3 acupoint.
Di Stefano, Danilo Alessio; Arosio, Paolo
2016-01-01
Bone density at implant placement sites is one of the key factors affecting implant primary stability, which is a determinant for implant osseointegration and rehabilitation success. Site-specific bone density assessment is, therefore, of paramount importance. Recently, an implant micromotor endowed with an instantaneous torque-measuring system has been introduced. The aim of this study was to assess the reliability of this system. Five blocks with different densities (0.16, 0.26, 0.33, 0.49, and 0.65 g/cm(3)) were used. A single trained operator measured the density of one of them (0.33 g/cm(3)), by means of five different devices (20 measurements/device). The five resulting datasets were analyzed through the analysis of variance (ANOVA) model to investigate interdevice variability. As differences were not significant (P = .41), the five devices were each assigned to a different operator, who collected 20 density measurements for each block, both under irrigation (I) and without irrigation (NI). Measurements were pooled and averaged for each block, and their correlation with the actual block-density values was investigated using linear regression analysis. The possible effect of irrigation on density measurement was additionally assessed. Different devices provided reproducible, homogenous results. No significant interoperator variability was observed. Within the physiologic range of densities (> 0.30 g/cm(3)), the linear regression analysis showed a significant linear correlation between the mean torque measurements and the actual bone densities under both drilling conditions (r = 0.990 [I], r = 0.999 [NI]). Calibration lines were drawn under both conditions. Values collected under irrigation were lower than those collected without irrigation at all densities. The NI/I mean torque ratio was shown to decrease linearly with density (r = 0.998). The mean error introduced by the device-operator system was less than 10% in the range of normal jawbone density
International Nuclear Information System (INIS)
Zwingelstein, Gilles; Thabet, Gabriel.
1977-01-01
Control algorithms for components of nuclear power plants are currently based on external diagnostic methods. Modeling and identification techniques for autoregressive moving average models (ARMA) for stochastic processes are described. The identified models provide a means of estimating the power spectral density with improved accuracy and computer time compared with the classical methods. They are particularly will suited for on-line estimation of the power spectral density. The observable stochastic process y (t) is modeled assuming that it is the output of a linear filter driven by Gaussian while noise w (t). Two identification schemes were tested to find the orders m and n of the ARMA (m,n) models and to estimate the parameters of the recursion equation relating the input and output signals. The first scheme consists in transforming the ARMA model to an autoregressive model. The parameters of this AR model are obtained using least squares estimation techniques. The second scheme consists in finding the parameters of the ARMA by nonlinear programming techniques. The power spectral density of y(t) is instantaneously deduced from these ARMA models [fr
Comparison of Kinetic Models for Dual-Tracer Receptor Concentration Imaging in Tumors
Hamzei, Nazanin; Samkoe, Kimberley S; Elliott, Jonathan T; Holt, Robert W; Gunn, Jason R; Hasan, Tayyaba; Pogue, Brian W; Tichauer, Kenneth M
2014-01-01
Molecular differences between cancerous and healthy tissue have become key targets for novel therapeutics specific to tumor receptors. However, cancer cell receptor expression can vary within and amongst different tumors, making strategies that can quantify receptor concentration in vivo critical for the progression of targeted therapies. Recently a dual-tracer imaging approach capable of providing quantitative measures of receptor concentration in vivo was developed. It relies on the simultaneous injection and imaging of receptor-targeted tracer and an untargeted tracer (to account for non-specific uptake of the targeted tracer). Early implementations of this approach have been structured on existing “reference tissue” imaging methods that have not been optimized for or validated in dual-tracer imaging. Using simulations and mouse tumor model experimental data, the salient findings in this study were that all widely used reference tissue kinetic models can be used for dual-tracer imaging, with the linearized simplified reference tissue model offering a good balance of accuracy and computational efficiency. Moreover, an alternate version of the full two-compartment reference tissue model can be employed accurately by assuming that the K1s of the targeted and untargeted tracers are similar to avoid assuming an instantaneous equilibrium between bound and free states (made by all other models). PMID:25414912
Stokes, M.; Perron, J. T.
2017-12-01
Freshwater systems host exceptionally species-rich communities whose spatial structure is dictated by the topology of the river networks they inhabit. Over geologic time, river networks are dynamic; drainage basins shrink and grow, and river capture establishes new connections between previously separated regions. It has been hypothesized that these changes in river network structure influence the evolution of life by exchanging and isolating species, perhaps boosting biodiversity in the process. However, no general model exists to predict the evolutionary consequences of landscape change. We couple a neutral community model of freshwater organisms to a landscape evolution model in which the river network undergoes drainage divide migration and repeated river capture. Neutral community models are macro-ecological models that include stochastic speciation and dispersal to produce realistic patterns of biodiversity. We explore the consequences of three modes of speciation - point mutation, time-protracted, and vicariant (geographic) speciation - by tracking patterns of diversity in time and comparing the final result to an equilibrium solution of the neutral model on the final landscape. Under point mutation, a simple model of stochastic and instantaneous speciation, the results are identical to the equilibrium solution and indicate the dominance of the species-area relationship in forming patterns of diversity. The number of species in a basin is proportional to its area, and regional species richness reaches its maximum when drainage area is evenly distributed among sub-basins. Time-protracted speciation is also modeled as a stochastic process, but in order to produce more realistic rates of diversification, speciation is not assumed to be instantaneous. Rather, each new species must persist for a certain amount of time before it is considered to be established. When vicariance (geographic speciation) is included, there is a transient signature of increased
Directory of Open Access Journals (Sweden)
Mihoko Sakurai
2012-12-01
Full Text Available A survey of the municipal government ICT divisions during and after the 2011 Great East Japan Earthquake and Tsunami crisis reveals the need for creative responses for “beyond assumed level” disasters. Complexity and diversity of the damage were simply too great for any plans to assume. Resident needs toward the municipal governments were also diverse and changed quickly as the time went by. The research also indicates that there would be ways to strengthen the capabilities to execute such spontaneous responses. Creative solutions executed during the 3.11 crisis were supported by the existence of open source software available on the net and skilled engineers that were capable of exploiting them. Frugal information system will be useful to improve preparedness for creative responses
National Aeronautics and Space Administration — The MAI6NPANA or inst6_3d_ana_Np data product is the MERRA Data Assimilation System 3-Dimensional instantaneous, on pressure levels, at native resolution. MERRA, or...
Directory of Open Access Journals (Sweden)
Dong Hoon Yi
2018-01-01
Full Text Available The migration of extensive social groups towards specific spawning grounds in vast and diverse ocean environments is an integral part of the regular spawning process of many oceanic fish species. Oceanic fish in such migrations typically seek locations with environmental parameters that maximize the probability of successful spawning and egg/larval survival. The 3D spatio-temporal dynamics of these behavioral processes are largely unknown due to technical difficulties in sensing the ocean environment over wide areas. Here, we use ocean acoustic waveguide remote sensing (OAWRS to instantaneously image immense herring groups over continental-shelf-scale areas at the Georges Bank spawning ground. Via multi-spectral OAWRS measurements, we capture a shift in swimbladder resonance peak correlated with the herring groups’ up-slope spawning migration, enabling 3D spatial behavioral dynamics to be instantaneously inferred over thousands of square kilometers. We show that herring groups maintain near-bottom vertical distributions with negative buoyancy throughout the migration. We find a spatial correlation greater than 0.9 between the average herring group depth and corresponding seafloor depth for migratory paths along the bathymetric gradient. This is consistent with herring groups maintaining near-seafloor paths to both search for optimal spawning conditions and reduce the risk of predator attacks during the migration to shallower waters where near-surface predators are more dangerous. This analysis shows that multi-spectral resonance sensing with OAWRS can be used as an effective tool to instantaneously image and continuously monitor the behavioral dynamics of swimbladder-bearing fish group behavior in three spatial dimensions over continental-shelf scales.
Zhou, Li-Xue; Ding, Hong; Jia, Cai-Xia; Li, Yan; Wei, Qing
2008-07-01
At present, the investigation of microbubble contrast agents is a hot spot. Although these contrast agents can increase the ultrasound detection rate of tumor vessels, they lack tissue specificity. This study was to evaluate the impact of instantaneous uniformity of SonoVue microbubbles on binding characteristics, including the adhesion rate and stability, of a new contrast agent targeted to choriocarcinoma cells (JARs) in vitro, in order to establish a foundation to explore targeted ultrasound imaging for localization of tumor cell antigens and increase the early diagnostic rate for tumors. The objects were divided into three groups: the uneven microbubble group (n=10), the uniform microbubble group (n=10) and the tiny microbubble group (n=10). The rosette formation rate was counted. JARs were calculated by flow cytometry (FCM). The shape of the rosette was recorded. The targeted contrast agent was prepared by mixing SonoVue microbubbles of different uniformity with rabbit anti-human chorionic gonadotrophin (HCG) antibody. The binding rates of the contrast agent to JARs before and after PBS rinse were analyzed. The binding rate was significantlylower in the uneven microbubble group (60.4+/-1.5)% than in the uniform microbubble group (84.3+/-5.5)% and the tiny microbubble group (90.6+/-6.8)% (P0.05). The binding rates of the targeted microbubbles labeled with fluorescence to JARs were 72.9%, 81.03% and 88.5% in the uneven microbubble group, the uniform microbubble group and the tiny microbubble group, respectively (PSonoVue microbubbles to JARs is related to instantaneous uniformity of the microbubble, which is determined by the shaking method before preparation. Improving instantaneous uniformity of SonoVue microbubbles may increase the binding rate and stability of targeted microbubbles to JARs, thus to improve the image of JARs.
International Nuclear Information System (INIS)
Fobel, Ryan; Fobel, Christian; Wheeler, Aaron R.
2013-01-01
We introduce DropBot: an open-source instrument for digital microfluidics (http://microfluidics.utoronto.ca/dropbot). DropBot features two key functionalities for digital microfluidics: (1) real-time monitoring of instantaneous drop velocity (which we propose is a proxy for resistive forces), and (2) application of constant electrostatic driving forces through compensation for amplifier-loading and device capacitance. We anticipate that this system will enhance insight into failure modes and lead to new strategies for improved device reliability, and will be useful for the growing number of users who are adopting digital microfluidics for automated, miniaturized laboratory operation.
Directory of Open Access Journals (Sweden)
Mu-Tzu Shih
2015-02-01
Full Text Available Depth of anaesthesia (DoA is an important measure for assessing the degree to which the central nervous system of a patient is depressed by a general anaesthetic agent, depending on the potency and concentration with which anaesthesia is administered during surgery. We can monitor the DoA by observing the patient’s electroencephalography (EEG signals during the surgical procedure. Typically high frequency EEG signals indicates the patient is conscious, while low frequency signals mean the patient is in a general anaesthetic state. If the anaesthetist is able to observe the instantaneous frequency changes of the patient’s EEG signals during surgery this can help to better regulate and monitor DoA, reducing surgical and post-operative risks. This paper describes an approach towards the development of a 3D real-time visualization application which can show the instantaneous frequency and instantaneous amplitude of EEG simultaneously by using empirical mode decomposition (EMD and the Hilbert–Huang transform (HHT. HHT uses the EMD method to decompose a signal into so-called intrinsic mode functions (IMFs. The Hilbert spectral analysis method is then used to obtain instantaneous frequency data. The HHT provides a new method of analyzing non-stationary and nonlinear time series data. We investigate this approach by analyzing EEG data collected from patients undergoing surgical procedures. The results show that the EEG differences between three distinct surgical stages computed by using sample entropy (SampEn are consistent with the expected differences between these stages based on the bispectral index (BIS, which has been shown to be quantifiable measure of the effect of anaesthetics on the central nervous system. Also, the proposed filtering approach is more effective compared to the standard filtering method in filtering out signal noise resulting in more consistent results than those provided by the BIS. The proposed approach is therefore
Jusoh, W J; Heaney, J G; Goldsmith, R E
2001-06-01
Consumers' self-assessments of materialism and status consumption may be influenced by external economic conditions. In this study, 239 Malaysian students were asked to describe their levels of materialism using Richins and Dawson's 1992 Materialism scale and status consumption using Eastman, Goldsmith, and Flynn's 1999 Status Consumption Scale. Half the students were told to respond assuming that they were in an expanding economy, and half as if the economy was in a recession. Comparison of the groups' mean scores showed no statistically significant differences.
A two-temperature model for shocked porous explosive
Lambourn, Brian; Handley, Caroline
2017-01-01
Mesoscale calculations of hotpots created by a shock wave in a porous explosive show that the hotspots do not cool in times of order at least a microsecond. This suggests that simple models of porosity like the Snowplough model, which assume that a shocked porous explosive jumps to a point on the Hugoniot that is instantaneously in thermodynamic equilibrium, are not correct. A two-temperature model of shocked porous explosive has been developed in which a small fraction of the material, representing the hotspots, has a high temperature, but the bulk of the material is cooler than the temperature calculated by the Snowplough model. In terms of the mean state of the material, it is shown that the two-temperature model only minimally affects the pressure vs. volume and shock velocity vs. particle velocity plot of the Hugoniot, but that the mean state lies slightly off the equation of state surface. The results of the model are compared with two dimensional mesoscale calculations.
ZMOTTO- MODELING THE INTERNAL COMBUSTION ENGINE
Zeleznik, F. J.
1994-01-01
The ZMOTTO program was developed to model mathematically a spark-ignited internal combustion engine. ZMOTTO is a large, general purpose program whose calculations can be established at five levels of sophistication. These five models range from an ideal cycle requiring only thermodynamic properties, to a very complex representation demanding full combustion kinetics, transport properties, and poppet valve flow characteristics. ZMOTTO is a flexible and computationally economical program based on a system of ordinary differential equations for cylinder-averaged properties. The calculations assume that heat transfer is expressed in terms of a heat transfer coefficient and that the cylinder average of kinetic plus potential energies remains constant. During combustion, the pressures of burned and unburned gases are assumed equal and their heat transfer areas are assumed proportional to their respective mass fractions. Even the simplest ZMOTTO model provides for residual gas effects, spark advance, exhaust gas recirculation, supercharging, and throttling. In the more complex models, 1) finite rate chemistry replaces equilibrium chemistry in descriptions of both the flame and the burned gases, 2) poppet valve formulas represent fluid flow instead of a zero pressure drop flow, and 3) flame propagation is modeled by mass burning equations instead of as an instantaneous process. Input to ZMOTTO is determined by the model chosen. Thermodynamic data is required for all models. Transport properties and chemical kinetics data are required only as the model complexity grows. Other input includes engine geometry, working fluid composition, operating characteristics, and intake/exhaust data. ZMOTTO accommodates a broad spectrum of reactants. The program will calculate many Otto cycle performance parameters for a number of consecutive cycles (a cycle being an interval of 720 crankangle degrees). A typical case will have a number of initial ideal cycles and progress through levels
International Nuclear Information System (INIS)
Kim, Sang-won; Jang, Gun-hyeon; Kim, Chang-beom; Go, Jae-dong; Ahn, Hyeong-jun; Rhyu, Jung; Chung, Sang-ki
2008-01-01
Article 122 of the Atomic Energy Act sets forth that 'executives and employees of an agency engaged in an entrusted work or its associated specialized agency, in the application of any punishment as per the Criminal Act or other laws, shall be regarded as civil servants,' stipulating that the scope of legal fictions to assume such persons are civil servants should be applicable to any punishment as per the Criminal Act or other laws. Accordingly, the executives and employees of an entrusted agency or its associated specialized agency are subject to the punishments not only for acceptance of graft but also for dereliction of duty or divulgence of classified information. In addition, they are also subject to increased punishment in accordance with other laws, for example, such special laws as Law Concerning Increased Punishment for Specified Crimes and Law Concerning Increased Punishment for Specified Economic Crimes
Kisu, I; Kato, Y; Yamada, Y; Matsubara, K; Obara, H; Emoto, K; Adachi, M; Umene, K; Nogami, Y; Banno, K; Kitagawa, Y; Aoki, D
2016-05-01
Clinical studies of uterus transplantation have been performed to treat uterine factor infertility. Because the uterus is a pelvic visceral organ, the method of perfusion for the procurement of vital organs from a brain-dead donor should be modified for removal of the uterus. Herein, we report the results of a preliminary study in cynomolgus monkeys of a new perfusion method for uterus transplantation with assumed procurement of a uterus from a brain-dead donor. Cynomolgus monkeys were used; thoracolaparotomy was performed on the donor. A perfusion catheter was then placed into the unilateral femoral artery and/or external iliac artery. Cross-clamping was performed for the aorta under the diaphragm and the inferior vena cava was divided in the pleural space. The perfusion solution was then administered via the catheter to perfuse all organs in the abdominal cavity, including those in the pelvic cavity. After the perfusion, gross observation and histopathological examination of abdominal organs were conducted. Gross findings showed that all abdominal organs turned white in all specimens, indicating favorable perfusion of the uterus and all other organs in the abdomen. Pathological findings showed that almost no hemocytes were observed in the vessels of each organ. With perfusion via the femoral artery and/or external iliac artery, all organs in the abdominal cavity, including the uterus, could be perfused. It was suggested that this technique could be useful for uterus transplantation assuming the procurement of a uterus from a brain-dead donor. Copyright © 2016 Elsevier Inc. All rights reserved.
Sato Processes in Default Modeling
DEFF Research Database (Denmark)
Kokholm, Thomas; Nicolato, Elisa
In reduced form default models, the instantaneous default intensity is classically the modeling object. Survival probabilities are then given by the Laplace transform of the cumulative hazard defined as the integrated intensity process. Instead, recent literature has shown a tendency towards...
Sato Processes in Default Modeling
DEFF Research Database (Denmark)
Kokholm, Thomas; Nicolato, Elisa
2010-01-01
In reduced form default models, the instantaneous default intensity is the classical modeling object. Survival probabilities are then given by the Laplace transform of the cumulative hazard defined as the integrated intensity process. Instead, recent literature tends to specify the cumulative...
Directory of Open Access Journals (Sweden)
Jimmy Boon Som Ong
Full Text Available The "classical model" for sexually transmitted infections treats partnerships as instantaneous events summarized by partner change rates, while individual-based and pair models explicitly account for time within partnerships and gaps between partnerships. We compared predictions from the classical and pair models over a range of partnership and gap combinations. While the former predicted similar or marginally higher prevalence at the shortest partnership lengths, the latter predicted self-sustaining transmission for gonorrhoea (GC and Chlamydia (CT over much broader partnership and gap combinations. Predictions on the critical level of condom use (C(c required to prevent transmission also differed substantially when using the same parameters. When calibrated to give the same disease prevalence as the pair model by adjusting the infectious duration for GC and CT, and by adjusting transmission probabilities for HIV, the classical model then predicted much higher C(c values for GC and CT, while C(c predictions for HIV were fairly close. In conclusion, the two approaches give different predictions over potentially important combinations of partnership and gap lengths. Assuming that it is more correct to explicitly model partnerships and gaps, then pair or individual-based models may be needed for GC and CT since model calibration does not resolve the differences.
Modeling and numerical simulation of multi-component flow in porous media
International Nuclear Information System (INIS)
Saad, B.
2011-01-01
This work deals with the modelization and numerical simulation of two phase multi-component flow in porous media. The study is divided into two parts. First we study and prove the mathematical existence in a weak sense of two degenerate parabolic systems modeling two phase (liquid and gas) two component (water and hydrogen) flow in porous media. In the first model, we assume that there is a local thermodynamic equilibrium between both phases of hydrogen by using the Henry's law. The second model consists of a relaxation of the previous model: the kinetic of the mass exchange between dissolved hydrogen and hydrogen in the gas phase is no longer instantaneous. The second part is devoted to the numerical analysis of those models. Firstly, we propose a numerical scheme to compare numerical solutions obtained with the first model and numerical solutions obtained with the second model where the characteristic time to recover the thermodynamic equilibrium goes to zero. Secondly, we present a finite volume scheme with a phase-by-phase upstream weighting scheme without simplified assumptions on the state law of gas densities. We also validate this scheme on a 2D test cases. (author)
Probabilistic predictive modelling of carbon nanocomposites for medical implants design.
Chua, Matthew; Chui, Chee-Kong
2015-04-01
Modelling of the mechanical properties of carbon nanocomposites based on input variables like percentage weight of Carbon Nanotubes (CNT) inclusions is important for the design of medical implants and other structural scaffolds. Current constitutive models for the mechanical properties of nanocomposites may not predict well due to differences in conditions, fabrication techniques and inconsistencies in reagents properties used across industries and laboratories. Furthermore, the mechanical properties of the designed products are not deterministic, but exist as a probabilistic range. A predictive model based on a modified probabilistic surface response algorithm is proposed in this paper to address this issue. Tensile testing of three groups of different CNT weight fractions of carbon nanocomposite samples displays scattered stress-strain curves, with the instantaneous stresses assumed to vary according to a normal distribution at a specific strain. From the probabilistic density function of the experimental data, a two factors Central Composite Design (CCD) experimental matrix based on strain and CNT weight fraction input with their corresponding stress distribution was established. Monte Carlo simulation was carried out on this design matrix to generate a predictive probabilistic polynomial equation. The equation and method was subsequently validated with more tensile experiments and Finite Element (FE) studies. The method was subsequently demonstrated in the design of an artificial tracheal implant. Our algorithm provides an effective way to accurately model the mechanical properties in implants of various compositions based on experimental data of samples. Copyright © 2015 Elsevier Ltd. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Watanabe, Edson H.; Aredes, Mauricio [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Lab. de Eletronica de Potencia]. E-mail: watanabe@coe.ufrj.br, aredes@cce.ufrj.br
1998-07-01
A tutorial about the instantaneous active and reactive power theory, which is valid for balanced and unbalanced three-phase systems, with and without harmonics is presented. Based on this theory the basic concepts involving the operation and design of shunt and series active and passive filters are also discussed. The advantage of the association of active and passive filters are also discussed. The association of shunt and series active filters to form the UPQC (Universal Power Quality Conditions), which guarantees the total compensation of voltage and current harmonics is also presented. As a result of the generalization of the UPFC (Unified Power Flow Controller) associated with the UPQC, the UPLC (Universal Active Power Line Conditioner) is proposed to compensate voltage and current harmonics as well as to control the power flow in a transmission line and regulate the ac bus voltage. (author)
Fang, Daniel Z; Patil, Teja; Belitskaya-Levy, Ilana; Yeung, Marianne; Posley, Keith; Allaudeen, Nazima
2017-11-17
Efficient and effective communication between providers is critical to quality patient care within a hospital system. Hands free communication devices (HFCD) allow instantaneous, closed-loop communication between physicians and other members of a multidisciplinary team, providing a communication advantage over traditional pager systems. HFCD have been shown to decrease emergency room interruptions, improve nursing communication, improve speed of information flow, and eliminate health care waste. We evaluated the integration of an HFCD with an existing alphanumeric paging system on an acute inpatient medicine service. We conducted a prospective, observational, survey-based study over twenty-four weeks in an academic tertiary care center with attending physicians and residents. Our intervention involved the implementation of an HFCD alongside the existing paging system. Fifty-six pre and post surveys evaluated the perception of improvement in communication and the integration of the HFCD into existing workflow. We saw significant improvements in the ability of an HFCD to help physicians communicate thoughts clearly, communicate thoughts effectively, reach team members, reach ancillary staff, and stay informed about patients. Physicians also reported better workflow integration during admissions, rounds, discharge, and teaching sessions. Qualitative data from post surveys demonstrated that the greatest strengths of the HFCD included the ability to reach colleagues and staff quickly, provide instant access to individuals of the care team, and improve overall communication. Integration of an instantaneous, hands free, closed loop communication system alongside the existing pager system can provide improvements in the perceptions of communication and workflow integration in an academic medicine service. Future studies are needed to correlate these subjective findings with objective measures of quality and safety.
Weinstein, R B
1995-04-01
Previous laboratory measurements of the energetics and biomechanics of locomotion have defined performance limits for the ghost crab Ocypode quadrata. To discover whether these animals naturally operate within these limits, a novel infrared videotaping system was used to observe nocturnally active ghost crabs in the field for three-dimensional motion analysis (N = 27) and focal animal sampling (N = 24). Instantaneous movement velocity, movement duration, pause duration and stride frequency were determined from video tapes. Voluntarily active crabs moved at a mean instantaneous velocity of 8 cm s-1. Stressed crabs (i.e. those captured and released into the field site) moved at a mean velocity of 83 cm s-1. The mean movement and pause period durations of voluntarily active animals moving along the beach were 11.2 and 23.4 s, respectively. Stressed crabs had much shorter movement (1.4 s) and pause (7.6 s) durations. Despite the differences in mean movement and pause duration, both voluntarily active and stressed crabs moved for an average of approximately 30% of the observation period. These data indicate that voluntarily active ghost crabs primarily move at velocities that can be sustained aerobically and that their performance is not likely to be altered by moving intermittently. By contrast, stressed crabs move at faster speeds that are closer to the limits of their continuous locomotor performance (e.g. escape behavior and aggressive encounters). In the laboratory, the endurance capacity of crabs moving continuously at these rapid speeds is only a few seconds. However, in the field, the stressed crabs are able to move intermittently for more than a few seconds, yet they do not fatigue. These observations suggest that the performance limits of the stressed crabs are increased by moving intermittently.
März, Karoline; Adler, Werner; Matta, Ragai-Edward; Wolf, Linda; Wichmann, Manfred; Bergauer, Bastian
2017-05-01
Orthodontists influence dental occlusion directly. To suggest any link between dental occlusion and body posture is highly contentious, as evidenced by the literature. Rasterstereography, an optical technique that enables three-dimensional (3D) body measurements to be collected, has not yet been used to impartially examine whether different occlusal positions could instantaneously alter spine and body posture. We therefore set out to use this technique to nonsubjectively evaluate this question under static conditions. Optical body scans were collected for 44 subjects, using the Diers formetric 4D system, for seven different mandible positions. In total, ten spinal and body posture parameters were assessed (trunk inclination, trunk imbalance, pelvic tilt, pelvic torsion, fleche cervicale, fleche lombaire, kyphotic angle, lordotic angle, surface rotation, and lateral deviation) for each mandible position and compared with scans performed with habitual intercuspation (HIC). Significant body posture deviations were found for the fleche cervicale (position of the mandible: right eccentrically), fleche lombaire (positions of the mandible: physiologic rest position, cotton rolls on both sides, bite elevation 1 mm), and the kyphotic angle (positions of the mandible: cotton rolls on both sides, right eccentrically). No other significant differences were detected. Data for the parameters that varied with different dental occlusions generated high standard deviations. Therefore, within the limitations of this pilot study, we could not conclusively associate dental occlusion to an instantaneous impact on the tested parameters. The posture changes that we detected could also have arisen from individual neuromuscular compensation; a possibility that must now be ruled-in, or out, by further research studies with a higher number of subjects.
Energy Technology Data Exchange (ETDEWEB)
Goncalez, Tifani T. [Universidade Federal do Rio Grande do Sul (PROMEC/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica; Segatto, Cynthia F.; Vilhena, Marco Tullio, E-mail: csegatto@pq.cnpq.b, E-mail: vilhena@pq.cnpq.b [Universidade Federal do Rio Grande do Sul (DMPA/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Matematica Aplicada
2011-07-01
In this work, we report an analytical solution for the set of S{sub N} equations for the angular flux, in a rectangle, using the double Laplace transform technique. Its main idea comprehends the steps: application of the Laplace transform in one space variable, solution of the resulting equation by the LTS{sub N} method and reconstruction of the double Laplace transformed angular flux using the inversion theorem of the Laplace transform. We must emphasize that we perform the Laplace inversion by the LTS{sub N} method in the x direction, meanwhile we evaluate the inversion in the y direction performing the calculation of the corresponding line integral solution by the Stefest method. We have also to figure out that the application of Laplace transform to this type of boundary value problem introduces additional unknown functions associated to the partial derivatives of the angular flux at boundary. Based on the good results attained by the nodal LTS{sub N} method, we assume that the angular flux at boundary is also approximated by an exponential function. By analytical we mean that no approximation is done along the solution derivation except for the exponential hypothesis for the exiting angular flux at boundary. For sake of completeness, we report numerical comparisons of the obtained results against the ones of the literature. (author)
Yamaguchi, Naoya; Hiramatsu, Kazuhiro; Shibata, Yoshihisa; Yoshihara, Motoi; Aoba, Taro; Kamiya, Tadahiro; Koike, Yoshio; Fujita, Takeru; Maeda, Chikara; Ito, Kisuke; Kanbara, Yuichi; Nishimura, Motonobu; Kobayashi, Ryutarou; Dei, Hideyuki; Takimoto, Aitaro; Nonaka, Yukiko; Kato, Takehito
2017-11-01
A 60-year old woman had been hospitalized in a psychiatric hospital for 40 years for schizophrenia. An X-ray was performed when she fell, which showed needles in the abdominal field. After additional examinations and questioning, the patient was diagnosed with needles in the abdominal cavity, which were assumed to have been ingested and to have perforated the GI tract 40 years ago. They were removed by laparoscopic surgery. The needles were found in the omentum and near the left ovary. There were no inflammatory reactions around them. There have been previous reports about the removal of intra-abdominal foreign bodies, but foreign body reaction occurred in most of the reports. Our case had the longest period from ingestion of the foreign bodies to their removal. Laparoscopy and intraoperative fluoroscopy are useful for removing intra-abdominal foreign bodies because of their ability to help discriminate between structures and to navigate in real time. © 2017 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and John Wiley & Sons Australia, Ltd.
Energy Technology Data Exchange (ETDEWEB)
Zhou, Shui-Ting; Huang, Hong-Wu [Hunan University, Changsha (China); Chiu, Yi-Jui; Yu, Guo-Fei [Xiamen University of Technology, Xiamen (China); Yang, Chia-Hao [Taipei Chengshih University of Science and Technology, Taipei (China); Jian, Sheng-Rui [I-Shou University, Kaohsiung (China)
2017-02-15
The Assumed mode method (AMM) and Finite element method (FEM) were used. Their results were compared to investigate the coupled shaft-torsion, disk-transverse, and blade-bending vibrations in a flexible-disk rotor system. The blades were grouped with a spring. The flexible-disk rotor system was divided into three modes of coupled vibrations: Shaft-disk-blade, disk-blade, and blade-blade. Two new modes of coupled vibrations were introduced, namely, lacing wires-blade and lacing wires-disk-blade. The patterns of change of the natural frequencies and mode shapes of the system were discussed. The results showed the following: first, mode shapes and natural frequencies varied, and the results of the AMM and FEM differed; second, numerical calculation results showed three influencing factors on natural frequencies, namely, the lacing wire constant, the lacing wire location, and the flexible disk; lastly, the flexible disk could affect the stability of the system as reflected in the effect of the rotational speed.
Modified Ammonia Removal Model Based on Equilibrium and Mass Transfer Principles
International Nuclear Information System (INIS)
Shanableh, A.; Imteaz, M.
2010-01-01
Yoon et al. 1 presented an approximate mathematical model to describe ammonia removal from an experimental batch reactor system with gaseous headspace. The development of the model was initially based on assuming instantaneous equilibrium between ammonia in the aqueous and gas phases. In the model, a 'saturation factor, β' was defined as a constant and used to check whether the equilibrium assumption was appropriate. The authors used the trends established by the estimated β values to conclude that the equilibrium assumption was not valid. The authors presented valuable experimental results obtained using a carefully designed system and the model used to analyze the results accounted for the following effects: speciation of ammonia between NH 3 and NH 4 + as a function of pH: temperature dependence of the reactions constants; and air flow rate. In this article, an alternative model based on the exact solution of the governing mass-balance differential equations was developed and used to describe ammonia removal without relying on the use of the saturation factor. The modified model was also extended to mathematically describe the pH dependence of the ammonia removal rate, in addition to accounting for the speciation of ammonia, temperature dependence of reactions constants, and air flow rate. The modified model was used to extend the analysis of the original experimental data presented by Yoon et al. 1 and the results matched the theory in an excellent manner
Energy Technology Data Exchange (ETDEWEB)
Eleftheriou, G., E-mail: gelefthe@central.ntua.gr [Department of Physics, National Technical University of Athens (Greece); Institute of Oceanography, Hellenic Centre for Marine Research (Greece); Monte, L., E-mail: monte.luigi@fastwebnet.it [ENEA, Roma (Italy); Brittain, J.E. [Natural History Museum, University of Oslo (Norway); Tsabaris, C. [Institute of Oceanography, Hellenic Centre for Marine Research (Greece)
2015-11-15
A radiological model for {sup 137}Cs and {sup 90}Sr dispersion in the marine environment of the Thermaikos Gulf, Greece, and the river catchments draining into the Gulf, is presented. The model, developed and implemented within the MOIRA-PLUS decision support system, integrates appropriate site-specific information. The model's performance has been tested using the available empirical {sup 137}Cs activity concentration data in abiotic and biotic components of the gulf since the Chernobyl accident. Further, this paper describes the results of a modelling exercise performed within the IAEA's EMRAS II international modelling programme to estimate the environmental sensitivity of this characteristic Mediterranean coastal marine environment following radioactive contamination. The radiation doses to humans after a single hypothetical instantaneous deposition of 1000 Bq m{sup −2}, assuming that all of their food intake from the marine pathway comes from the local environment, were calculated. The obtained results are consistent with estimates from other models for different coastal marine environments in the frame of the above-mentioned EMRAS exercise. - Highlights: • The Decision Support System (DSS) MOIRA-PLUS was customised to Thermaikos Gulf. • Model results were compared with empirical data to adjust parameter values. • The environmental sensitivity of the Gulf to {sup 90}Sr and {sup 137}Cs pollution was assessed. • Radiation doses from marine and fresh water pathways were compared. • The dose from fresh water pathways is notably higher than that from marine pathways.
International Nuclear Information System (INIS)
Eleftheriou, G.; Monte, L.; Brittain, J.E.; Tsabaris, C.
2015-01-01
A radiological model for 137 Cs and 90 Sr dispersion in the marine environment of the Thermaikos Gulf, Greece, and the river catchments draining into the Gulf, is presented. The model, developed and implemented within the MOIRA-PLUS decision support system, integrates appropriate site-specific information. The model's performance has been tested using the available empirical 137 Cs activity concentration data in abiotic and biotic components of the gulf since the Chernobyl accident. Further, this paper describes the results of a modelling exercise performed within the IAEA's EMRAS II international modelling programme to estimate the environmental sensitivity of this characteristic Mediterranean coastal marine environment following radioactive contamination. The radiation doses to humans after a single hypothetical instantaneous deposition of 1000 Bq m −2 , assuming that all of their food intake from the marine pathway comes from the local environment, were calculated. The obtained results are consistent with estimates from other models for different coastal marine environments in the frame of the above-mentioned EMRAS exercise. - Highlights: • The Decision Support System (DSS) MOIRA-PLUS was customised to Thermaikos Gulf. • Model results were compared with empirical data to adjust parameter values. • The environmental sensitivity of the Gulf to 90 Sr and 137 Cs pollution was assessed. • Radiation doses from marine and fresh water pathways were compared. • The dose from fresh water pathways is notably higher than that from marine pathways
Gintautas, Vadas; Hubler, Alfred
2006-03-01
As worldwide computer resources increase in power and decrease in cost, real-time simulations of physical systems are becoming increasingly prevalent, from laboratory models to stock market projections and entire ``virtual worlds'' in computer games. Often, these systems are meticulously designed to match real-world systems as closely as possible. We study the limiting behavior of a virtual horizontally driven pendulum coupled to its real-world counterpart, where the interaction occurs on a time scale that is much shorter than the time scale of the dynamical system. We find that if the physical parameters of the virtual system match those of the real system within a certain tolerance, there is a qualitative change in the behavior of the two-pendulum system as the strength of the coupling is increased. Applications include a new method to measure the physical parameters of a real system and the use of resonance spectroscopy to refine a computer model. As virtual systems better approximate real ones, even very weak interactions may produce unexpected and dramatic behavior. The research is supported by the National Science Foundation Grant No. NSF PHY 01-40179, NSF DMS 03-25939 ITR, and NSF DGE 03-38215.
Foam rheology: a model of viscous phenomena
International Nuclear Information System (INIS)
Kraynik, A.M.; Hansen, M.G.
1987-01-01
A theoretical model for foam rheology that includes viscous forces is developed by considering the deformation of two-dimensional, spatially periodic cells in simple shearing and planar extensional flow. The undeformed hexagonal cells are separated by thin liquid films. Plateau border curvature and liquid drainage between films is neglected. Interfacial tension and viscous tractions due to stretching lamellar liquid determine the individual film tensions. The network motion is described by a system of nonlinear ordinary differential equations for which numerical solutions are obtained. Coalescense and disproportionation of Plateau borders results in the relative separation of cells and provides a mechanism for yielding and flow. This process is assumed to occur when a film's length reduces to its thickness. The time and position dependence of the cell-scale dynamics are computed explicitly. The effective continuum stress of the foam is described by instantaneous and time-averaged quantities. The capillary number, a dimensionless deformation rate, represents the relative importance of viscous and surface tension effects. The small-capillary-number or quasistatic response determines a yield stress. The dependence of the shear and normal stress material functions upon deformation rate, foam structure and physical properties is determined. A plausible mechanism for shear-induced material failure, which would determine a shear strength, is revealed for large capillary numbers. The mechanism involves large cell distortion and film thinning, which provide favorable conditions for film rupture
A Probabilistic Model of Spin and Spin Measurements
Niehaus, Arend
2016-01-01
Several theoretical publications on the Dirac equation published during the last decades have shown that, an interpretation is possible, which ascribes the origin of electron spin and magnetic moment to an autonomous circular motion of the point-like charged particle around a fixed centre. In more recent publications an extension of the original so called "Zitterbewegung Interpretation" of quantum mechanics was suggested, in which the spin results from an average of instantaneous spin vectors over a Zitterbewegung period. We argue that, the corresponding autonomous motion of the electron should, if it is real, determine non-relativistic spin measurements. Such a direct connection with the established formal quantum mechanical description of spin measurements, into which spin is introduced as a "non-classical" quantity has, to our knowledge, not been reported. In the present work we show that, under certain "model assumptions" concerning the proposed autonomous motion, results of spin measurements, including measurements of angular correlations in singlet systems, can indeed be correctly described using classical probabilities. The success of the model is evidence for the "reality" of the assumed autonomous motion. The resulting model violates the Bell—inequalities to the same extent as quantum mechanics.
Physical modelling of a rapid boron dilution transient
Energy Technology Data Exchange (ETDEWEB)
Anderson, N.G.; Hemstroem, B.; Karlsson, R. [Vattenfall Utveckling AB, Aelvkarleby (Sweden); Jacobson, S. [Vattenfall AB, Ringhals, Vaeroebacka (Sweden)
1995-09-01
The analysis of boron dilution accidents in pressurised water reactors has traditionally assumed that mixing is instantaneous and complete everywhere, eliminating in this way the possibility of concentration inhomogeneities. Situations can nevertheless arise where a volume of coolant with a low boron concentration may eventually enter the core and generate a severe reactivity transient. The work presented in this paper deals with a category of Rapid Boron Dilution Events characterised by a rapid start of a Reactor Coolant Pump (RCP) with a plug of relatively unborated water present in the RCS pipe. Model tests have been made at Vattenfall Utveckling AB in a simplified 1:5 scale model of a Westinghouse PWR. Conductivity measurements are used to determine dimensionless boron concentration. The main purpose of this experimental work is to define an experimental benchmark against which a mathematical model can be tested. The final goal is to be able to numerically predict Boron Dilution Transients. This work has been performed as a part of a Co-operative Agreement with Electricite` de France (EDF).
A model of proto-object based saliency
Russell, Alexander F.; Mihalaş, Stefan; von der Heydt, Rudiger; Niebur, Ernst; Etienne-Cummings, Ralph
2013-01-01
Organisms use the process of selective attention to optimally allocate their computational resources to the instantaneously most relevant subsets of a visual scene, ensuring that they can parse the scene in real time. Many models of bottom-up attentional selection assume that elementary image features, like intensity, color and orientation, attract attention. Gestalt psychologists, how-ever, argue that humans perceive whole objects before they analyze individual features. This is supported by recent psychophysical studies that show that objects predict eye-fixations better than features. In this report we present a neurally inspired algorithm of object based, bottom-up attention. The model rivals the performance of state of the art non-biologically plausible feature based algorithms (and outperforms biologically plausible feature based algorithms) in its ability to predict perceptual saliency (eye fixations and subjective interest points) in natural scenes. The model achieves this by computing saliency as a function of proto-objects that establish the perceptual organization of the scene. All computational mechanisms of the algorithm have direct neural correlates, and our results provide evidence for the interface theory of attention. PMID:24184601
Directory of Open Access Journals (Sweden)
Xiyang He
2015-12-01
Full Text Available Many applications, such as marine navigation, land vehicles location, etc., require real time precise positioning under medium or long baseline conditions. In this contribution, we develop a model of real-time kinematic decimeter-level positioning with BeiDou Navigation Satellite System (BDS triple-frequency signals over medium distances. The ambiguities of two extra-wide-lane (EWL combinations are fixed first, and then a wide lane (WL combination is reformed based on the two EWL combinations for positioning. Theoretical analysis and empirical analysis is given of the ambiguity fixing rate and the positioning accuracy of the presented method. The results indicate that the ambiguity fixing rate can be up to more than 98% when using BDS medium baseline observations, which is much higher than that of dual-frequency Hatch-Melbourne-Wübbena (HMW method. As for positioning accuracy, decimeter level accuracy can be achieved with this method, which is comparable to that of carrier-smoothed code differential positioning method. Signal interruption simulation experiment indicates that the proposed method can realize fast high-precision positioning whereas the carrier-smoothed code differential positioning method needs several hundreds of seconds for obtaining high precision results. We can conclude that a relatively high accuracy and high fixing rate can be achieved for triple-frequency WL method with single-epoch observations, displaying significant advantage comparing to traditional carrier-smoothed code differential positioning method.
Temporal structures in shell models
DEFF Research Database (Denmark)
Okkels, F.
2001-01-01
The intermittent dynamics of the turbulent Gledzer, Ohkitani, and Yamada shell-model is completely characterized by a single type of burstlike structure, which moves through the shells like a front. This temporal structure is described by the dynamics of the instantaneous configuration of the shell...
Directory of Open Access Journals (Sweden)
N. Zhao
2017-07-01
Full Text Available In the context of global warming attributable to the increasing levels of CO2, severe drought may be more frequent in areas that already experience chronic water shortages (semiarid areas. This necessitates research on the interactions between increased levels of CO2 and drought and their effect on plant photosynthesis. It is commonly reported that 13C fractionation occurs as CO2 gas diffuses from the atmosphere to the substomatal cavity. Few researchers have investigated 13C fractionation at the site of carboxylation to cytoplasm before sugars are exported outward from the leaf. This process typically progresses in response to variations in environmental conditions (i.e., CO2 concentrations and water stress, including in their interaction. Therefore, saplings of two typical plant species (Platycladus orientalis and Quercus variabilis from semiarid areas of northern China were selected and cultivated in growth chambers with orthogonal treatments (four CO2 concentration ([CO2] × five soil volumetric water content (SWC. The δ13C of water-soluble compounds extracted from leaves of saplings was determined for an assessment of instantaneous water use efficiency (WUEcp after cultivation. Instantaneous water use efficiency derived from gas-exchange measurements (WUEge was integrated to estimate differences in δ13C signal variation before leaf-level translocation of primary assimilates. The WUEge values in P. orientalis and Q. variabilis both decreased with increased soil moisture at 35–80 % of field capacity (FC and increased with elevated [CO2] by increasing photosynthetic capacity and reducing transpiration. Instantaneous water use efficiency (iWUE according to environmental changes differed between the two species. The WUEge in P. orientalis was significantly greater than that in Q. variabilis, while an opposite tendency was observed when comparing WUEcp between the two species. Total 13C fractionation at the site of
Zhao, Na; Meng, Ping; He, Yabing; Yu, Xinxiao
2017-07-01
In the context of global warming attributable to the increasing levels of CO2, severe drought may be more frequent in areas that already experience chronic water shortages (semiarid areas). This necessitates research on the interactions between increased levels of CO2 and drought and their effect on plant photosynthesis. It is commonly reported that 13C fractionation occurs as CO2 gas diffuses from the atmosphere to the substomatal cavity. Few researchers have investigated 13C fractionation at the site of carboxylation to cytoplasm before sugars are exported outward from the leaf. This process typically progresses in response to variations in environmental conditions (i.e., CO2 concentrations and water stress), including in their interaction. Therefore, saplings of two typical plant species (Platycladus orientalis and Quercus variabilis) from semiarid areas of northern China were selected and cultivated in growth chambers with orthogonal treatments (four CO2 concentration ([CO2]) × five soil volumetric water content (SWC)). The δ13C of water-soluble compounds extracted from leaves of saplings was determined for an assessment of instantaneous water use efficiency (WUEcp) after cultivation. Instantaneous water use efficiency derived from gas-exchange measurements (WUEge) was integrated to estimate differences in δ13C signal variation before leaf-level translocation of primary assimilates. The WUEge values in P. orientalis and Q. variabilis both decreased with increased soil moisture at 35-80 % of field capacity (FC) and increased with elevated [CO2] by increasing photosynthetic capacity and reducing transpiration. Instantaneous water use efficiency (iWUE) according to environmental changes differed between the two species. The WUEge in P. orientalis was significantly greater than that in Q. variabilis, while an opposite tendency was observed when comparing WUEcp between the two species. Total 13C fractionation at the site of carboxylation to cytoplasm before sugar
International Nuclear Information System (INIS)
Jimeno, Austin Ed B.; Chakraborty, Soma
2015-01-01
Polymeric electrolytic complexes are solutions of charged/ionized chains. These solutions of positive and negative charge can be combined to make instantaneous networks bonded by electrostatic interactions, a gel network. These electrostatic interaction allows for easy application in injectable gels as the network can be temporarily distributed with the application of force and reformed on the relief of it. Possible applications for these injectable gels include drug delivery and wound-healing. κ-Carrageenan, dextran sulfate, alginate, and chitosan are polyelectrolytic biocompatible polymers which are widely studied and used for a variety of biomedical applications. Gel networks are made by combining a negatively-charged (κ-Carrageenan, dextran sulfate, or alginate) and positively charged (chitosan) solutions. The strong electrostatic interaction between the opposite charges from the gel network and the inherent biocompatibility of the polymers allow future biomedical applications. Quat 188-modified chitosan has additional sites for electrostatic bonding, can be dissolved in neutral, basic, and acidic pH, and has shown inherent antibacterial activity. The objectives of this study are the following: to formulate chitosan-based gels mixing solutions of chitosan with solutions of either κ-Carrageenan, dextran sulfate, or alginate, study the gelation of the gels as function of time and pH (4, 7, and 9) using UV-Vis, characterize the chitosan-based gels through DSC and DMA, characterize the physiological degradation of the chitosan-based gels, and compare results with those from Quat 188-modified chitosan-based gels. Polyelectrolytic solutions of chitosan and negatively-charged biopolymer of similar viscosities were mixed. It was determined from the UV-Vis spectroscopy of the chitosan-carrageenan gels under pH7 buffer that the increase of concentration by a factor of 5 for 0.006M-0.0095M and 1.25 for 0.0095M-0.0150M Chitosan-Carrageenan gels improved gelation by the
Escaned, Javier; Echavarría-Pinto, Mauro; Garcia-Garcia, Hector M.; van de Hoef, Tim P.; de Vries, Ton; Kaul, Prashant; Raveendran, Ganesh; Altman, John D.; Kurz, Howard I.; Brechtken, Johannes; Tulli, Mark; von Birgelen, Clemens; Schneider, Joel E.; Khashaba, Ahmed A.; Jeremias, Allen; Baucum, Jim; Moreno, Raul; Meuwissen, Martijn; Mishkel, Gregory; van Geuns, Robert-Jan; Levite, Howard; Lopez-Palop, Ramon; Mayhew, Marc; Serruys, Patrick W.; Samady, Habib; Piek, Jan J.; Lerman, Amir; Khashaba, A.; Lasorda, D.; Meuwissen, M.; Levite, H.; Allaqaband, S.; Roberts, J.; Nseir, G.; Jones, S.; Samady, H.; van Geuns, R.; Raveendran, G.; Preli, R.; Blankenship, J.; Baucum, J.; Orlando, Q.; Escaned, J.; Palop, R.; Moreno, R.; Legutko, J.; Möllman, H.; Tulli, M.; Stables, R.; Gulati, R.; Powers, E.; Gil, R.; Carrabus, B.; Reczuch, K.; Brechtken, J.; Schneider, J.; Della Siega, A.; Mahoney, P.; Altman, J.; Mishkel, G.; Jeremias, A.; von Birgelen, C.; Kaul, P.; Fernandes, V.; Kurz, H.; Mayhew, M.; Tai, Z.
2015-01-01
The purpose of this study was to assess the diagnostic accuracy of the instantaneous wave-free ratio (iFR) to characterize, outside of a pre-specified range of values, stenosis severity, as defined by fractional flow reserve (FFR) ≤0.80, in a prospective, independent, controlled, core
Cook, Christopher M; Ahmad, Yousif; Shun-Shin, Matthew J; Nijjer, Sukhjinder; Petraco, Ricardo; Al-Lamee, Rasha; Mayet, Jamil; Francis, Darrel P; Sen, Sayan; Davies, Justin E
2016-04-01
Small drifts in intracoronary pressure measurements (±2 mm Hg) can affect stenosis categorization using pressure indices. This has not previously been assessed for fractional flow reserve (FFR), instantaneous wave-free ratio (iFR), and whole-cycle distal pressure/proximal pressure (Pd/Pa) indices. Four hundred forty-seven stenoses were assessed with FFR, iFR, and whole-cycle Pd/Pa. Cut point values for significance were predefined as ≤0.8, Pa indices were recalculated and stenosis misclassification quantified. Median (±median absolute deviation) values for FFR, iFR, and whole-cycle Pd/Pa were 0.81 (±0.11), 0.90 (±0.07), and 0.93 (±0.06), respectively. For the cut point of FFR, iFR, and whole-cycle Pd/Pa, 34.6% (155), 50.1% (224), and 62.2% (278) of values, respectively, lay within ±0.05 U. With ±2 mm Hg pressure wire drift, 21% (94), 25% (110), and 33% (148) of the study population were misclassified with FFR, iFR, and whole-cycle Pd/Pa, respectively. Both FFR and iFR had significantly lower misclassification than whole-cycle Pd/Pa (PPa is more vulnerable to such reclassification than FFR and iFR. © 2016 The Authors.
International Nuclear Information System (INIS)
Selmi, A.L.; Padilha Filho, J.G.; Lins, B.T.; Mendes, G.M.; Eimantas, G.C.
2007-01-01
The instantaneous center of motion (ICM) and velocity vector (Vv), after transection of the cranial cruciate ligament (CCL) followed by a fascial strip reconstruction in association with intercondylar notchplasty (IN), were studied in nine adult dogs. The right stifle was submitted to IN followed by fascial strip reconstruction of the CCL (GI) while in the left stifle IN was not performed (GC). Dogs were evaluated the day prior to surgery, immediately after surgery and at 30, 90 and 180 days postoperatively (po), time at which a subgroup of three dogs were euthanatized. The ICM and resulting Vv were determined by radiographic examination of the stifle. All the stifles presented normally positioned ICM and Vv before surgery. No changes were observed in ICM or Vv in all stifles following intra-articular repair, in association or not with IN, throughout the evaluation period, despite the fact that three dogs in GC and two in GI presented a positive cranial drawer sign immediately following surgery, two dogs in GC and GI at 30 days po, and one single dog in each group thereafter until 180 days po. It is concluded that articular repair, in association with IN or not, did not alter stifle biomechanics, in respect to ICM and Vv [pt
Directory of Open Access Journals (Sweden)
Yan Li
Full Text Available Reactive oxygen species (ROS have been established to participate in stomatal closure induced by live microbes and microbe-associated molecular patterns (MAMPs. Chlorella as a beneficial microorganism can be expected to trigger stomatal closure via ROS production. Here, we reported that Chlorella induced stomatal closure in a dose-and time-dependent manner in epidermal peels of Vicia faba. Using pharmacological methods in this work, we found that the Chlorella-induced stomatal closure was almost completely abolished by a hydrogen peroxide (H2O2 scavenger, catalase (CAT, significantly suppressed by an NADPH oxidase inhibitor, diphenylene iodonium chloride (DPI, and slightly affected by a peroxidase inhibitor, salicylhydroxamic acid (SHAM, suggesting that ROS production involved in Chlorella-induced stomatal closure is mainly mediated by DPI-sensitive NADPH oxidase. Additionally, Exogenous application of optimal concentrations of Chlorella suspension improved instantaneous water use efficiency (WUEi in Vicia faba via a reduction in leaf transpiration rate (E without a parallel reduction in net photosynthetic rate (Pn assessed by gas-exchange measurements. The chlorophyll fluorescence and content analysis further demonstrated that short-term use of Chlorella did not influence plant photosynthetic reactions center. These results preliminarily reveal that Chlorella can trigger stomatal closure via NADPH oxidase-dependent ROS production in epidermal strips and improve WUEi in leave levels.
Li, Yan; Xu, Shan-Shan; Gao, Jing; Pan, Sha; Wang, Gen-Xuan
2014-01-01
Reactive oxygen species (ROS) have been established to participate in stomatal closure induced by live microbes and microbe-associated molecular patterns (MAMPs). Chlorella as a beneficial microorganism can be expected to trigger stomatal closure via ROS production. Here, we reported that Chlorella induced stomatal closure in a dose-and time-dependent manner in epidermal peels of Vicia faba. Using pharmacological methods in this work, we found that the Chlorella-induced stomatal closure was almost completely abolished by a hydrogen peroxide (H2O2) scavenger, catalase (CAT), significantly suppressed by an NADPH oxidase inhibitor, diphenylene iodonium chloride (DPI), and slightly affected by a peroxidase inhibitor, salicylhydroxamic acid (SHAM), suggesting that ROS production involved in Chlorella-induced stomatal closure is mainly mediated by DPI-sensitive NADPH oxidase. Additionally, Exogenous application of optimal concentrations of Chlorella suspension improved instantaneous water use efficiency (WUEi) in Vicia faba via a reduction in leaf transpiration rate (E) without a parallel reduction in net photosynthetic rate (Pn) assessed by gas-exchange measurements. The chlorophyll fluorescence and content analysis further demonstrated that short-term use of Chlorella did not influence plant photosynthetic reactions center. These results preliminarily reveal that Chlorella can trigger stomatal closure via NADPH oxidase-dependent ROS production in epidermal strips and improve WUEi in leave levels.
'instantaneous velocimetry' using an interferometer
Indian Academy of Sciences (India)
2017-02-08
Feb 8, 2017 ... The experimental set-up consists of a laser source, a microscopic objective, a pin hole with an observer plane, a camera, a Peltier heater and a solid sample. When a monochromatic light source is switched ON, the light passes through the microscopic objective and the pin hole produces a 'slowly diverging.
Abdallah, J.; Adam, W.; Adzic, P.; Albrecht, T.; Alderweireld, T.; Alemany-Fernandez, R.; Allmendinger, T.; Allport, P.P.; Amaldi, U.; Amapane, N.; Amato, S.; Anashkin, E.; Andreazza, A.; Andringa, S.; Anjos, N.; Antilogus, P.; Apel, W.D.; Arnoud, Y.; Ask, S.; Asman, B.; Augustin, J.E.; Augustinus, A.; Baillon, P.; Ballestrero, A.; Bambade, P.; Barbier, R.; Bardin, D.; Barker, G.J.; Baroncelli, A.; Battaglia, M.; Baubillier, M.; Becks, K.H.; Begalli, M.; Behrmann, A.; Ben-Haim, E.; Benekos, N.; Benvenuti, A.; Berat, C.; Berggren, M.; Berntzon, L.; Bertrand, D.; Besancon, M.; Besson, N.; Bloch, D.; Blom, M.; Bluj, M.; Bonesini, M.; Boonekamp, M.; Booth, P.S.L.; Borisov, G.; Botner, O.; Bouquet, B.; Bowcock, T.J.V.; Boyko, I.; Bracko, M.; Brenner, R.; Brodet, E.; Bruckman, P.; Brunet, J.M.; Bugge, L.; Buschmann, P.; Calvi, M.; Camporesi, T.; Canale, V.; Carena, F.; Castro, Nuno Filipe; Cavallo, F.; Chapkin, M.; Charpentier, Ph.; Checchia, P.; Chierici, R.; Chliapnikov, P.; Chudoba, J.; Chung, S.U.; Cieslik, K.; Collins, P.; Contri, R.; Cosme, G.; Cossutti, F.; Costa, M.J.; Crennell, D.; Cuevas, J.; D'Hondt, J.; Dalmau, J.; da Silva, T.; Da Silva, W.; Della Ricca, G.; De Angelis, A.; De Boer, W.; De Clercq, C.; De Lotto, B.; De Maria, N.; De Min, A.; de Paula, L.; Di Ciaccio, L.; Di Simone, A.; Doroba, K.; Drees, J.; Dris, M.; Eigen, G.; Ekelof, T.; Ellert, M.; Elsing, M.; Espirito Santo, M.C.; Fanourakis, G.; Fassouliotis, D.; Feindt, M.; Fernandez, J.; Ferrer, A.; Ferro, F.; Flagmeyer, U.; Foeth, H.; Fokitis, E.; Fulda-Quenzer, F.; Fuster, J.; Gandelman, M.; Garcia, C.; Gavillet, Ph.; Gazis, Evangelos; Gokieli, R.; Golob, B.; Gomez-Ceballos, G.; Goncalves, P.; Graziani, E.; Grosdidier, G.; Grzelak, K.; Guy, J.; Haag, C.; Hallgren, A.; Hamacher, K.; Hamilton, K.; Haug, S.; Hauler, F.; Hedberg, V.; Hennecke, M.; Herr, H.; Hoffman, J.; Holmgren, S.O.; Holt, P.J.; Houlden, M.A.; Hultqvist, K.; Jackson, John Neil; Jarlskog, G.; Jarry, P.; Jeans, D.; Johansson, Erik Karl; Johansson, P.D.; Jonsson, P.; Joram, C.; Jungermann, L.; Kapusta, Frederic; Katsanevas, S.; Katsoufis, E.; Kernel, G.; Kersevan, B.P.; Kerzel, U.; Kiiskinen, A.; King, B.T.; Kjaer, N.J.; Kluit, P.; Kokkinias, P.; Kourkoumelis, C.; Kouznetsov, O.; Krumstein, Z.; Kucharczyk, M.; Lamsa, J.; Leder, G.; Ledroit, Fabienne; Leinonen, L.; Leitner, R.; Lemonne, J.; Lepeltier, V.; Lesiak, T.; Liebig, W.; Liko, D.; Lipniacka, A.; Lopes, J.H.; Lopez, J.M.; Loukas, D.; Lutz, P.; Lyons, L.; MacNaughton, J.; Malek, A.; Maltezos, S.; Mandl, F.; Marco, J.; Marco, R.; Marechal, B.; Margoni, M.; Marin, J.C.; Mariotti, C.; Markou, A.; Martinez-Rivero, C.; Masik, J.; Mastroyiannopoulos, N.; Matorras, F.; Matteuzzi, C.; Mazzucato, F.; Mazzucato, M.; McNulty, R.; Meroni, C.; Migliore, E.; Mitaroff, W.; Mjoernmark, U.; Moa, T.; Moch, M.; Monig, Klaus; Monge, R.; Montenegro, J.; Moraes, D.; Moreno, S.; Morettini, P.; Mueller, U.; Muenich, K.; Mulders, M.; Mundim, L.; Murray, W.; Muryn, B.; Myatt, G.; Myklebust, T.; Nassiakou, M.; Navarria, F.; Nawrocki, K.; Nicolaidou, R.; Nikolenko, M.; Oblakowska-Mucha, A.; Obraztsov, V.; Olshevski, A.; Onofre, A.; Orava, R.; Osterberg, K.; Ouraou, A.; Oyanguren, A.; Paganoni, M.; Paiano, S.; Palacios, J.P.; Palka, H.; Papadopoulou, Th.D.; Pape, L.; Parkes, C.; Parodi, F.; Parzefall, U.; Passeri, A.; Passon, O.; Peralta, L.; Perepelitsa, V.; Perrotta, A.; Petrolini, A.; Piedra, J.; Pieri, L.; Pierre, F.; Pimenta, M.; Piotto, E.; Podobnik, T.; Poireau, V.; Pol, M.E.; Polok, G.; Pozdniakov, V.; Pukhaeva, N.; Pullia, A.; Rames, J.; Read, Alexander L.; Rebecchi, P.; Rehn, J.; Reid, D.; Reinhardt, R.; Renton, P.; Richard, F.; Ridky, J.; Rivero, M.; Rodriguez, D.; Romero, A.; Ronchese, P.; Roudeau, P.; Rovelli, T.; Ruhlmann-Kleider, V.; Ryabtchikov, D.; Sadovsky, A.; Salmi, L.; Salt, J.; Sander, C.; Savoy-Navarro, A.; Schwickerath, U.; Segar, A.; Sekulin, R.; Siebel, M.; Sisakian, A.; Smadja, G.; Smirnova, O.; Sokolov, A.; Sopczak, A.; Sosnowski, R.; Spassov, T.; Stanitzki, M.; Stocchi, A.; Strauss, J.; Stugu, B.; Szczekowski, M.; Szeptycka, M.; Szumlak, T.; Tabarelli, T.; Taffard, A.C.; Tegenfeldt, F.; Timmermans, Jan; Tkatchev, L.; Tobin, M.; Todorovova, S.; Tome, B.; Tonazzo, A.; Tortosa, P.; Travnicek, P.; Treille, D.; Tristram, G.; Trochimczuk, M.; Troncon, C.; Turluer, M.L.; Tyapkin, I.A.; Tyapkin, P.; Tzamarias, S.; Uvarov, V.; Valenti, G.; Van Dam, Piet; Van Eldik, J.; Van Lysebetten, A.; van Remortel, N.; Van Vulpen, I.; Vegni, G.; Veloso, F.; Venus, W.; Verdier, P.; Verzi, V.; Vilanova, D.; Vitale, L.; Vrba, V.; Wahlen, H.; Washbrook, A.J.; Weiser, C.; Wicke, D.; Wickens, J.; Wilkinson, G.; Winter, M.; Witek, M.; Yushchenko, O.; Zalewska, A.; Zalewski, P.; Zavrtanik, D.; Zhuravlov, V.; Zimine, N.I.; Zintchenko, A.; Zupan, M.
2004-01-01
Searches for pair-production of supersymmetric particles under the assumption of non-conservation of R-parity with a dominant LLEbar or UbarDbarDbar term have been performed using the data collected by the DELPHI experiment at LEP in e+e- collisions at centre-of-mass energies from 192 up to 208 GeV. No excess of data above Standard Model expectations was observed. The results were used to constrain the MSSM parameter space and to derive limits on the masses of supersymmetric particles.
Barberis, Lucas; Peruani, Fernando
2016-12-01
We study a minimal cognitive flocking model, which assumes that the moving entities navigate using the available instantaneous visual information exclusively. The model consists of active particles, with no memory, that interact by a short-ranged, position-based, attractive force, which acts inside a vision cone (VC), and lack velocity-velocity alignment. We show that this active system can exhibit—due to the VC that breaks Newton's third law—various complex, large-scale, self-organized patterns. Depending on parameter values, we observe the emergence of aggregates or millinglike patterns, the formation of moving—locally polar—files with particles at the front of these structures acting as effective leaders, and the self-organization of particles into macroscopic nematic structures leading to long-ranged nematic order. Combining simulations and nonlinear field equations, we show that position-based active models, as the one analyzed here, represent a new class of active systems fundamentally different from other active systems, including velocity-alignment-based flocking systems. The reported results are of prime importance in the study, interpretation, and modeling of collective motion patterns in living and nonliving active systems.
Energy Technology Data Exchange (ETDEWEB)
Lukic, S
2004-10-15
The work presented in this thesis is situated in the context of the GEDEON program of neutron cross-section measurements. This program is motivated by the perspectives recently opened by projects of nuclear waste treatment and energy production. There is an obvious lack of experimental data on (n,xn) reactions in the databases, especially in the case of very radioactive isotopes. An important technique to measure cross-sections of these reactions is the prompt {gamma}-ray spectroscopy at white pulsed neutron beams with very high instantaneous flux. In this work, inelastic scattering and (n,xn) reactions cross-section measurements were performed on a lead sample from threshold to 20 MeV by prompt {gamma}-ray spectroscopy at the white neutron beam generated by GELINA facility in Geel, Belgium. Digital methods were developed to treat HPGe CLOVER detector signals and separate {gamma}-rays induced by the fastest neutrons from those belonging to the flash. Partial cross-sections for the production of several transitions in natural lead were measured and analyzed using theoretical calculations in order to separate the contributions of different reactions leading to the same residual isotope. Total cross-sections of the reactions in question were estimated. The results were compared to the TALYSS code theoretical calculations, as well as to other experimental results. This experiment has served to validate the method and it opens the way to measure (n,xn) reactions cross-sections with high instantaneous neutron flux on actinides, particularly the U{sup 233}(n,2n) reaction which is important for the thorium cycle. (author)
Modeling of Evaporation Losses in Sewage Sludge Drying Bed ...
African Journals Online (AJOL)
A model for evaporation losses in sewage sludge drying bed was derived from first principles. This model was developed based on the reasoning that the rate at which evaporation is taking place is directly proportional to the instantaneous quantity of water in the sludge. The aim of this work was to develop a model to assist ...
Rtimi, Sami; Sanjines, Rosendo; Pulgarin, Cesar; Kiwi, John
2016-01-13
The first evidence for Cu-Ag (50%/50%) nanoparticulate hybrid coatings is presented leading to a complete and almost instantaneous bacterial inactivation in the dark (≤5 min). Dark bacterial inactivation times on Cu-Ag (50%/50%) were observed to coincide with the times required by actinic light irradiation. This provides the evidence that the bimetal Cu-Ag driven inactivation predominates over a CuO/Cu2O and Ag2O oxides inducing a semiconductor driven behavior. Cu- or Ag-coated polyurethane (PU) catheters led to bacterial inactivation needing about ∼30 min. The accelerated bacterial inactivation by Cu-Ag coated on 3D catheters sputtered was investigated in a detailed way. The release of Cu/Ag ions during bacterial inactivation was followed by inductively coupled plasma mass-spectrometry (ICP-MS) and the amount of Cu and Ag-ions released were below the cytotoxicity levels permitted by the sanitary regulations. By stereomicroscopy the amount of live/dead cells were followed during the bacterial inactivation time. By Fourier transform infrared spectroscopy (FTIR), the systematic shift of the -(CH2) band stretching of the outer lipo-polysaccharide bilayer (LPS) was followed to monitor the changes leading to cell lysis. A hydrophobic to hydrophilic transformation of the Cu-Ag PU catheter surface under light was observed within 30 min followed concomitantly to a longer back transformation to the hydrophobic initial state in the dark. Physical insight is provided for the superior performance of Cu-Ag films compared to Cu or Ag films in view of the drastic acceleration of the bacterial inactivation observed on bimetal Cu-Ag films coating PU catheters. A mechanism of bacterial inactivation is suggested that is consistent with the findings reported in this study.
Wang, Ke; Zhao, Yang; Chen, Deyong; Huang, Chengjun; Fan, Beiyuan; Long, Rong; Hsieh, Chia-Hsun; Wang, Junbo; Wu, Min-Hsien; Chen, Jian
2017-06-19
This paper presents the instrumentation of a microfluidic analyzer enabling the characterization of single-cell biophysical properties, which includes seven key components: a microfluidic module, a pressure module, an imaging module, an impedance module, two LabVIEW platforms for instrument operation and raw data processing, respectively, and a Python code for data translation. Under the control of the LabVIEW platform for instrument operation, the pressure module flushes single cells into the microfluidic module with raw biophysical parameters sampled by the imaging and impedance modules and processed by the LabVIEW platform for raw data processing, which were further translated into intrinsic cellular biophysical parameters using the code developed in Python. Based on this system, specific membrane capacitance, cytoplasm conductivity, and instantaneous Young's modulus of three cell types were quantified as 2.76 ± 0.57 μF/cm², 1.00 ± 0.14 S/m, and 3.79 ± 1.11 kPa for A549 cells ( n cell = 202); 1.88 ± 0.31 μF/cm², 1.05 ± 0.16 S/m, and 3.74 ± 0.75 kPa for 95D cells ( n cell = 257); 2.11 ± 0.38 μF/cm², 0.87 ± 0.11 S/m, and 5.39 ± 0.89 kPa for H460 cells ( n cell = 246). As a semi-automatic instrument with a throughput of roughly 1 cell per second, this prototype instrument can be potentially used for the characterization of cellular biophysical properties.
Götberg, Matthias; Christiansen, Evald H; Gudmundsdottir, Ingibjörg; Sandhall, Lennart; Omerovic, Elmir; James, Stefan K; Erlinge, David; Fröbert, Ole
2015-11-01
Instantaneous wave-free ratio (iFR) is a new hemodynamic resting index for assessment of coronary artery stenosis severity. iFR uses high frequency sampling to calculate a gradient across a coronary lesion during a period of diastole. The index has been tested against fractional flow reserve (FFR) and found to have an overall classification agreement of 80% to 85%. Whether the level of disagreement is clinically relevant is unknown. Clinical outcome data on iFR are scarce. This study is a registry-based randomized clinical trial, which is a novel strategy using health quality registries as on-line platforms for randomization, case record forms, and follow-up. iFR-SWEDEHEART is a multicenter, prospective, randomized, controlled, clinical open-label clinical trial. Two thousand patients with stable angina or acute coronary syndrome and an indication for physiology-guided assessment of one or more coronary stenoses will be randomized 1:1 to either iFR- or FFR-guided intervention. The randomization will be conducted online in the Swedish web-based system for enhancement and development of evidence-based care in heart disease evaluated according to recommended therapies (SWEDEHEART) registry. The trial has a non-inferiority design, with a primary combined end point of all-cause death, non-fatal myocardial infarction, and unplanned revascularization at 12 months. End points will be identified through national registries and undergo central blind adjudication to ensure data quality. The iFR-SWEDEHEART trial is an registry-based randomized clinical trial evaluating the safety and efficacy of the diagnostic method iFR compared to FFR. Copyright © 2015 Elsevier Inc. All rights reserved.
Sanabria-DeLong, Naomi; Crosby, Alfred J; Tew, Gregory N
2008-10-01
Poly(lactide)-block-poly(ethylene oxide)-block-poly(lactide) (PLA-PEO-PLA) triblock copolymers are known to form physical hydrogels in water as a result of the polymer's amphiphilicity. Their mechanical properties, biocompatibility, and biodegradability have made them attractive for use as soft tissue scaffolds. However, the network junction points are not covalently cross-linked, and in a highly aqueous environment these hydrogels adsorb more water, transform from gel to sol, and lose the designed mechanical properties. In this article, a hydrogel was formed by the use of a novel two-step approach. In the first step, the end-functionalized PLA-PEO-PLA triblock was self-assembled into a physical hydrogel through hydrophobic micelle network junctions, and in the second step, this self-assembled physical network structure was locked into place by photo-cross-linking the terminal acrylate groups. In contrast with physical hydrogels, the photo-cross-linked gels remained intact in phosphate-buffered solution at body temperature. The swelling, degradation, and mechanical properties were characterized, and they demonstrated an extended degradation time (approximately 65 days), an exponential decrease in modulus with degradation time, and a tunable shear modulus (1.6-133 kPa). We also discuss the various constitutive relationships (Hookean, neo-Hookean, and Mooney-Rivlin) that can be used to describe the stress-strain behavior of these hydrogels. The chosen model and assumptions used for data fitting influenced the obtained modulus values by as much as a factor of 3.5, which demonstrates the importance of clearly stating one's data fitting parameters so that accurate comparisons can be made within the literature.
Dhavalikar, R.; Hensley, D.; Maldonado-Camargo, L.; Croft, L. R.; Ceron, S.; Goodwill, P. W.; Conolly, S. M.; Rinaldi, C.
2016-08-01
Magnetic particle imaging (MPI) is an emerging tomographic imaging technology that detects magnetic nanoparticle tracers by exploiting their non-linear magnetization properties. In order to predict the behavior of nanoparticles in an imager, it is possible to use a non-imaging MPI relaxometer or spectrometer to characterize the behavior of nanoparticles in a controlled setting. In this paper we explore the use of ferrohydrodynamic magnetization equations for predicting the response of particles in an MPI relaxometer. These include a magnetization equation developed by Shliomis (Sh) which has a constant relaxation time and a magnetization equation which uses a field-dependent relaxation time developed by Martsenyuk, Raikher and Shliomis (MRSh). We compare the predictions from these models with measurements and with the predictions based on the Langevin function that assumes instantaneous magnetization response of the nanoparticles. The results show good qualitative and quantitative agreement between the ferrohydrodynamic models and the measurements without the use of fitting parameters and provide further evidence of the potential of ferrohydrodynamic modeling in MPI.
Painlevé's paradox and dynamic jamming in simple models of passive dynamic walking
Or, Yizhar
2014-02-01
Painlevé's paradox occurs in the rigid-body dynamics of mechanical systems with frictional contacts at configurations where the instantaneous solution is either indeterminate or inconsistent. Dynamic jamming is a scenario where the solution starts with consistent slippage and then converges in finite time to a configuration of inconsistency, while the contact force grows unbounded. The goal of this paper is to demonstrate that these two phenomena are also relevant to the field of robotic walking, and can occur in two classical theoretical models of passive dynamic walking — the rimless wheel and the compass biped. These models typically assume sticking contact and ignore the possibility of foot slippage, an assumption which requires sufficiently large ground friction. Nevertheless, even for large friction, a perturbation that involves foot slippage can be kinematically enforced due to external forces, vibrations, or loose gravel on the surface. In this work, the rimless wheel and compass biped models are revisited, and it is shown that the periodic solutions under sticking contact can suffer from both Painlevé's paradox and dynamic jamming when given a perturbation of foot slippage. Thus, avoidance of these phenomena and analysis of orbital stability with respect to perturbations that include slippage are of crucial importance for robotic legged locomotion.
International Nuclear Information System (INIS)
Kwon, Kye-Si
2010-01-01
In situ techniques to measure the drop-on-demand (DOD) drop formation curve and the instantaneous jetting speed curve are developed such that ligament behavior and satellite behavior of inkjet droplets can be analyzed effectively. It is known that the droplet jetting behavior differs by ink properties and the driving waveform voltage. In this study, to reduce possible droplet placement errors due to satellite drops or long ligaments during printing, waveform effects on drop formation are investigated based on the measured DOD drop formation curve and the instantaneous jetting speed curve. Experimental results show that a dwell time greater than the so-called efficient dwell time was effective in reducing placement errors due to satellite drops during the printing process
Extending the radial diffusion model of Falthammar to non-dipole background field
Energy Technology Data Exchange (ETDEWEB)
Cunningham, Gregory Scott [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-05-26
A model for radial diffusion caused by electromagnetic disturbances was published by Falthammar (1965) using a two-parameter model of the disturbance perturbing a background dipole magnetic field. Schulz and Lanzerotti (1974) extended this model by recognizing the two parameter perturbation as the leading (non--dipole) terms of the Mead Williams magnetic field model. They emphasized that the magnetic perturbation in such a model induces an electric ield that can be calculated from the motion of field lines on which the particles are ‘frozen’. Roederer and Zhang (2014) describe how the field lines on which the particles are frozen can be calculated by tracing the unperturbed field lines from the minimum-B location to the ionospheric footpoint, and then tracing the perturbed field (which shares the same ionospheric footpoint due to the frozen -in condition) from the ionospheric footpoint back to a perturbed minimum B location. The instantaneous change n Roederer L*, dL*/dt, can then be computed as the product (dL*/dphi)*(dphi/dt). dL*/Dphi is linearly dependent on the perturbation parameters (to first order) and is obtained by computing the drift across L*-labeled perturbed field lines, while dphi/dt is related to the bounce-averaged gradient-curvature drift velocity. The advantage of assuming a dipole background magnetic field, as in these previous studies, is that the instantaneous dL*/dt can be computed analytically (with some approximations), as can the DLL that results from integrating dL*/dt over time and computing the expected value of (dL*)^2. The approach can also be applied to complex background magnetic field models like T89 or TS04, on top of which the small perturbations are added, but an analytical solution is not possible and so a numerical solution must be implemented. In this talk, I discuss our progress in implementing a numerical solution to the calculation of DL*L* using arbitrary background field models with simple electromagnetic
Luther's thought assumed form in polemics
DEFF Research Database (Denmark)
Vind, Anna
2014-01-01
Luther’s polemic reflects not self-confidence but confidence in God’s Word. His polemic arose in the context of the university disputation, which sought truth and examined skills through disputation. Luther discovered God’s Word’s ability to serve as weapon against his foes. In several literary...... genres Luther’s versatile use of a range of polemical devices countered positions he regarded as false. The necessity of opposing such positions provoked his expansion and deepening of formulations of doctrine and ecclesiastical practice on various topics, including Christian freedom, the external...... character of God’s Word, and other doctrines. Luther’s polemic also served pastoral purposes, defending the faithful against error....
Is CERN Council assuming its responsibilities?
Association du personnel
2008-01-01
Before the June official meetings, the Staff Association handed over a letter (see following page) to the President of CERN Council in support of the recommendation of the Governing Board of the Pension Fund to increase contributions by 0.76%, as a step towards a better balance of our Fund.
development of an integrated production inventory model for a ...
African Journals Online (AJOL)
... production inventory system is extended for non-instantaneous production and integrated with concept of inventory models with cost changes. Integer multiple parameters are used as a check factor for cost minimization. A numerical example is also presented. KeyWords Inventory, Production, Optimization, Modeling
A CFD-informed quasi-steady model of flapping wing aerodynamics.
Nakata, Toshiyuki; Liu, Hao; Bomphrey, Richard J
2015-11-01
Aerodynamic performance and agility during flapping flight are determined by the combination of wing shape and kinematics. The degree of morphological and kinematic optimisation is unknown and depends upon a large parameter space. Aimed at providing an accurate and computationally inexpensive modelling tool for flapping-wing aerodynamics, we propose a novel CFD (computational fluid dynamics)-informed quasi-steady model (CIQSM), which assumes that the aerodynamic forces on a flapping wing can be decomposed into the quasi-steady forces and parameterised based on CFD results. Using least-squares fitting, we determine a set of proportional coefficients for the quasi-steady model relating wing kinematics to instantaneous aerodynamic force and torque; we calculate power with the product of quasi-steady torques and angular velocity. With the quasi-steady model fully and independently parameterised on the basis of high-fidelity CFD modelling, it is capable of predicting flapping-wing aerodynamic forces and power more accurately than the conventional blade element model (BEM) does. The improvement can be attributed to, for instance, taking into account the effects of the induced downwash and the wing tip vortex on the force generation and power consumption. Our model is validated by comparing the aerodynamics of a CFD model and the present quasi-steady model using the example case of a hovering hawkmoth. It demonstrates that the CIQSM outperforms the conventional BEM while remaining computationally cheap, and hence can be an effective tool for revealing the mechanisms of optimization and control of kinematics and morphology in flapping-wing flight for both bio-flyers and unmanned air systems.
Numerical modelling of accretion, sintering and differentiation of asteroid 4 Vesta
Neumann, W.; Breuer, D.; Spohn, T.
2012-09-01
The Dawn mission provided more precise values of e.g. the mass, the bulk density and the dimensions of the asteroid 4 Vesta. The ground-based observations prior to the mission indicated a dry, basaltic surface composition meaning that the body is differentiated and has been resurfaced by basaltic lava flows. The latter distinguishes Vesta from primordial planetesimals like 21 Lutetia which retained its native surface material (and may still be partially differentiated[1]). The differentiated interior is confirmed by the mass concentration towards the centre of Vesta measured by Dawn. In fact, the core is expected to have 214-226 km in diameter[2]. In the present study numerical calculations of the thermochemical evolution of the asteroid 4 Vesta have been performed adopting the new data obtained by the Dawn mission. We have used the thermal evolution model by [3], which includes accretion (based on the accretion model by [4]), sintering of the accreting porous material due to hot pressing[5], associated changes of the material properties (such as density and thermal conductivity), melting, convective heat transport and differentiation by porous flow of chondritic planetesimals. The heat transport by melt segregation is modeled assuming melt flow in porous media and by supplementing the energy balance equation with additional advection terms. The advection terms for iron and silicate melts are calculated using the Darcy flow equation. This approach is valid for melt fractions large enough such that the melt forms an interconnected network but lower than the rheological critical melt fraction (≈50%). In particular we compare the evolution scenarios arising from the instantaneous (Fig. 1)accretion of Vesta at different formation times t0 (relative to the formation of the calcium-aluminum rich inclusions) with those arising from various noninstantaneous accretion rates. This is important due to the competition between heating in the interior and heat loss through the
Directory of Open Access Journals (Sweden)
P. Räisänen
2017-12-01
Full Text Available Snow consists of non-spherical grains of various shapes and sizes. Still, in radiative transfer calculations, snow grains are often treated as spherical. This also applies to the computation of snow albedo in the Snow, Ice, and Aerosol Radiation (SNICAR model and in the Los Alamos sea ice model, version 4 (CICE4, both of which are employed in the Community Earth System Model and in the Norwegian Earth System Model (NorESM. In this study, we evaluate the effect of snow grain shape on climate simulated by NorESM in a slab ocean configuration of the model. An experiment with spherical snow grains (SPH is compared with another (NONSPH in which the snow shortwave single-scattering properties are based on a combination of three non-spherical snow grain shapes optimized using measurements of angular scattering by blowing snow. The key difference between these treatments is that the asymmetry parameter is smaller in the non-spherical case (0.77–0.78 in the visible region than in the spherical case ( ≈ 0.89. Therefore, for the same effective snow grain size (or equivalently, the same specific projected area, the snow broadband albedo is higher when assuming non-spherical rather than spherical snow grains, typically by 0.02–0.03. Considering the spherical case as the baseline, this results in an instantaneous negative change in net shortwave radiation with a global-mean top-of-the-model value of ca. −0.22 W m−2. Although this global-mean radiative effect is rather modest, the impacts on the climate simulated by NorESM are substantial. The global annual-mean 2 m air temperature in NONSPH is 1.17 K lower than in SPH, with substantially larger differences at high latitudes. The climatic response is amplified by strong snow and sea ice feedbacks. It is further demonstrated that the effect of snow grain shape could be largely offset by adjusting the snow grain size. When assuming non-spherical snow grains with the parameterized grain
Räisänen, Petri; Makkonen, Risto; Kirkevåg, Alf; Debernard, Jens B.
2017-12-01
Snow consists of non-spherical grains of various shapes and sizes. Still, in radiative transfer calculations, snow grains are often treated as spherical. This also applies to the computation of snow albedo in the Snow, Ice, and Aerosol Radiation (SNICAR) model and in the Los Alamos sea ice model, version 4 (CICE4), both of which are employed in the Community Earth System Model and in the Norwegian Earth System Model (NorESM). In this study, we evaluate the effect of snow grain shape on climate simulated by NorESM in a slab ocean configuration of the model. An experiment with spherical snow grains (SPH) is compared with another (NONSPH) in which the snow shortwave single-scattering properties are based on a combination of three non-spherical snow grain shapes optimized using measurements of angular scattering by blowing snow. The key difference between these treatments is that the asymmetry parameter is smaller in the non-spherical case (0.77-0.78 in the visible region) than in the spherical case ( ≈ 0.89). Therefore, for the same effective snow grain size (or equivalently, the same specific projected area), the snow broadband albedo is higher when assuming non-spherical rather than spherical snow grains, typically by 0.02-0.03. Considering the spherical case as the baseline, this results in an instantaneous negative change in net shortwave radiation with a global-mean top-of-the-model value of ca. -0.22 W m-2. Although this global-mean radiative effect is rather modest, the impacts on the climate simulated by NorESM are substantial. The global annual-mean 2 m air temperature in NONSPH is 1.17 K lower than in SPH, with substantially larger differences at high latitudes. The climatic response is amplified by strong snow and sea ice feedbacks. It is further demonstrated that the effect of snow grain shape could be largely offset by adjusting the snow grain size. When assuming non-spherical snow grains with the parameterized grain size increased by ca. 70 %, the
REVIEW: Going beyond the LIBOR model
Javaheri, Alireza
2004-06-01
Having a mostly equity derivatives background, I was concerned that I would find this book too complex. I therefore started reading it with misgiving. However, the first thing Rebonato does is to give a concise yet thorough history of the evolution of interest-rate derivatives. Starting with the famous Black model, one assumes that either the forward rate or the swap rate (fixed rate) is log-normal. Using the forward rate would allow us to deal with the `pull to par' phenomenon: the fact that the price of a bond must be par at its maturity. Note that, as Rebonato points out, some were even ignoring this phenomenon and using the Black - Scholes pricing formula. The justification was that in their cases, the bond maturity was far beyond the option maturity. This model has been, and still is, popular due to its simplicity and the fact that it allows us to price many vanilla instruments (caps and swaptions) exactly. However, as Rebonato keeps telling us, this exact replication is deceiving. Indeed they take place under different probability measures and, therefore, the replications are inconsistent with one another. This means that if you were to price an exotic derivative with multiple call dates or exercise dates, you would not have one internally plausible framework to do so. Then came the short-rate models such as the Vasicek model or the Cox, Ingersoll and Ross (CIR) model. They treated the instantaneous short interest rate as the driving force of the term structure. This short rate therefore followed a stochastic differential equation (SDE) of its own which was mean reverting. However, these models did not guarantee matching of the market. An extension to these models, mainly by Hull and White on the one hand and Jamshidian on the other hand, was the following: make the drift term a time-dependent deterministic function that we would resolve in order to match various vanilla prices. But once again, the same issue raises its ugly head. If we are pricing non
Gas Removal in the Ursa Minor Galaxy: Linking Hydrodynamics and Chemical Evolution Models
Energy Technology Data Exchange (ETDEWEB)
Caproni, Anderson; Lanfranchi, Gustavo Amaral; Baio, Gabriel Henrique Campos; Kowal, Grzegorz [Núcleo de Astrofísica Teórica, Universidade Cruzeiro do Sul, R. Galvão Bueno 868, Liberdade, 01506-000, São Paulo, SP (Brazil); Falceta-Gonçalves, Diego, E-mail: anderson.caproni@cruzeirodosul.edu.br [Escola de Artes, Ciências e Humanidades, Universidade de São Paulo, Rua Arlindo Bettio 1000, CEP 03828-000 São Paulo (Brazil)
2017-04-01
We present results from a non-cosmological, three-dimensional hydrodynamical simulation of the gas in the dwarf spheroidal galaxy Ursa Minor. Assuming an initial baryonic-to-dark-matter ratio derived from the cosmic microwave background radiation, we evolved the galactic gas distribution over 3 Gyr, taking into account the effects of the types Ia and II supernovae. For the first time, we used in our simulation the instantaneous supernovae rates derived from a chemical evolution model applied to spectroscopic observational data of Ursa Minor. We show that the amount of gas that is lost in this process is variable with time and radius, being the highest rates observed during the initial 600 Myr in our simulation. Our results indicate that types Ia and II supernovae must be essential drivers of the gas loss in Ursa Minor galaxy (and probably in other similar dwarf galaxies), but it is ultimately the combination of galactic winds powered by these supernovae and environmental effects (e.g., ram-pressure stripping) that results in the complete removal of the gas content.
Energy Technology Data Exchange (ETDEWEB)
Caro, F
2004-11-15
This work deals with the modelling and numerical simulation of liquid-vapor phase transition phenomena. The study is divided into two part: first we investigate phase transition phenomena with a Van Der Waals equation of state (non monotonic equation of state), then we adopt an alternative approach with two equations of state. In the first part, we study the classical viscous criteria for selecting weak solutions of the system used when the equation of state is non monotonic. Those criteria do not select physical solutions and therefore we focus a more recent criterion: the visco-capillary criterion. We use this criterion to exactly solve the Riemann problem (which imposes solving an algebraic scalar non linear equation). Unfortunately, this step is quite costly in term of CPU which prevent from using this method as a ground for building Godunov solvers. That is why we propose an alternative approach two equations of state. Using the least action principle, we propose a phase changing two-phase flow model which is based on the second thermodynamic principle. We shall then describe two equilibrium submodels issued from the relaxations processes when instantaneous equilibrium is assumed. Despite the weak hyperbolicity of the last sub-model, we propose stable numerical schemes based on a two-step strategy involving a convective step followed by a relaxation step. We show the ability of the system to simulate vapor bubbles nucleation. (author)
Efficient use of the velocity gradients tensor in flow modelling
Passchier, C.W.
1987-01-01
For models of fabric development in rocks, with vorticity as a variable parameter, the choice of an unsuitable reference frame for instantaneous flow can hamper clear presentation of results. The orientation of most fabric elements which develop in deforming rocks is attached to some principal
Flow diagnostics downstream of a tribladed rotor model
DEFF Research Database (Denmark)
Naumov, I. V.; Rahmanov, V. V.; Okulov, Valery
2012-01-01
This paper presents results of a study of vortex wake structures and measurements of instantaneous 3D velocity fields downstream of a triblade turbine model. Two operation modes of flow around the rotor with different tip speed ratios were tested. Initially the wake structures were visualized and...
Pusateri, Elise Noel
An Electromagnetic Pulse (EMP) can severely disrupt the use of electronic devices in its path causing a significant amount of infrastructural damage. EMP can also cause breakdown of the surrounding atmosphere during lightning discharges. This makes modeling EMP phenomenon an important research effort in many military and atmospheric physics applications. EMP events include high-energy Compton electrons or photoelectrons that ionize air and produce low energy conduction electrons. A sufficient number of conduction electrons will damp or alter the EMP through conduction current. Therefore, it is important to understand how conduction electrons interact with air in order to accurately predict the EMP evolution and propagation in the air. It is common for EMP simulation codes to use an equilibrium ohmic model for computing the conduction current. Equilibrium ohmic models assume the conduction electrons are always in equilibrium with the local instantaneous electric field, i.e. for a specific EMP electric field, the conduction electrons instantaneously reach steady state without a transient process. An equilibrium model will work well if the electrons have time to reach their equilibrium distribution with respect to the rise time or duration of the EMP. If the time to reach equilibrium is comparable or longer than the rise time or duration of the EMP then the equilibrium model would not accurately predict the conduction current necessary for the EMP simulation. This is because transport coefficients used in the conduction current calculation will be found based on equilibrium reactions rates which may differ significantly from their non-equilibrium values. We see this deficiency in Los Alamos National Laboratory's EMP code, CHAP-LA (Compton High Altitude Pulse-Los Alamos), when modeling certain EMP scenarios at high altitudes, such as upward EMP, where the ionization rate by secondary electrons is over predicted by the equilibrium model, causing the EMP to short
Emde, Claudia; Barlakas, Vasileios; Cornet, Céline; Evans, Frank; Wang, Zhen; Labonotte, Laurent C.; Macke, Andreas; Mayer, Bernhard; Wendisch, Manfred
2018-04-01
Initially unpolarized solar radiation becomes polarized by scattering in the Earth's atmosphere. In particular molecular scattering (Rayleigh scattering) polarizes electromagnetic radiation, but also scattering of radiation at aerosols, cloud droplets (Mie scattering) and ice crystals polarizes. Each atmospheric constituent produces a characteristic polarization signal, thus spectro-polarimetric measurements are frequently employed for remote sensing of aerosol and cloud properties. Retrieval algorithms require efficient radiative transfer models. Usually, these apply the plane-parallel approximation (PPA), assuming that the atmosphere consists of horizontally homogeneous layers. This allows to solve the vector radiative transfer equation (VRTE) efficiently. For remote sensing applications, the radiance is considered constant over the instantaneous field-of-view of the instrument and each sensor element is treated independently in plane-parallel approximation, neglecting horizontal radiation transport between adjacent pixels (Independent Pixel Approximation, IPA). In order to estimate the errors due to the IPA approximation, three-dimensional (3D) vector radiative transfer models are required. So far, only a few such models exist. Therefore, the International Polarized Radiative Transfer (IPRT) working group of the International Radiation Commission (IRC) has initiated a model intercomparison project in order to provide benchmark results for polarized radiative transfer. The group has already performed an intercomparison for one-dimensional (1D) multi-layer test cases [phase A, 1]. This paper presents the continuation of the intercomparison project (phase B) for 2D and 3D test cases: a step cloud, a cubic cloud, and a more realistic scenario including a 3D cloud field generated by a Large Eddy Simulation (LES) model and typical background aerosols. The commonly established benchmark results for 3D polarized radiative transfer are available at the IPRT website (http
Energy Technology Data Exchange (ETDEWEB)
Baldwin, D.G. (Univ. of Colorado, Boulder (USA)); Coakley, J.A. (Oregon State Univ., Corvallis (USA))
1991-03-20
The Earth Radiation Budget Experiment (ERBE) uses bidirectional models to estimate radiative fluxes from observed radiances. The anisotropy of the radiance field derived from these models is compared with that observed with the ERBE scanner on the Earth Radiation Budget Satellite (ERBS). The bidirectional models used by ERBE were derived from NIMBUS 7 Earth radiation budget (ERB) scanner observations. Because of probable differences in the radiometric calibrations of the ERB and ERBE scanners and because of differences in their field of view sizes, the authors expect to find systematic differences of a few percent between the NIMBUS 7 ERB-derived radiation field anisotropy and the ERBS scanner-observed anisotropy. The differences expected are small compared with the variability of the anisotropy which arises from the variability in cloud cover allowed to occur within the individual scene types. By averaging over groups of 40 ERBE scanner scan lines (equivalent to an average over approximately 2,000 km) for a period of a month, they detect significant differences between the modeled and observed anisotropy for particular scene types and Sun-Earth-satellite viewing geometries. For a typical 2.5{degree} latitude-longitude region these differences give rise to a bias in the radiative flux that is at least 0.3% for the monthly mean and an rms error that is at least 4% for instantaneous observations. By comparing the fluxes derived using the observed anisotropy with those derived assuming isotropic reflection, they conclude that a reasonable estimate for the maximum error due to the use of incorrect bidirectional models is a bias of approximately 4% for a typical 2.5{degree} latitude-longitude, monthly mean and an rms error of 15%.
Power-based electric vehicle energy consumption model: Model development and validation
International Nuclear Information System (INIS)
Fiori, Chiara; Ahn, Kyoungho; Rakha, Hesham A.
2016-01-01
Highlights: • The study developed an instantaneous energy consumption model (VT-CPEM) for EVs. • The model captures instantaneous braking energy regeneration. • The model can be used for transportation modeling and vehicle applications (e.g. eco-routing). • The proposed model can be easily calibrated using publically available EV data. • Usages of air conditioning and heating systems reduce EV energy consumption by up to 10% and 24%, respectively. - Abstract: The limited drive range (The maximum distance that an EV can travel.) of Electric Vehicles (EVs) is one of the major challenges that EV manufacturers are attempting to overcome. To this end, a simple, accurate, and efficient energy consumption model is needed to develop real-time eco-driving and eco-routing systems that can enhance the energy efficiency of EVs and thus extend their travel range. Although numerous publications have focused on the modeling of EV energy consumption levels, these studies are limited to measuring energy consumption of an EV’s control algorithm, macro-project evaluations, or simplified well-to-wheels analyses. Consequently, this paper addresses this need by developing a simple EV energy model that computes an EV’s instantaneous energy consumption using second-by-second vehicle speed, acceleration and roadway grade data as input variables. In doing so, the model estimates the instantaneous braking energy regeneration. The proposed model can be easily implemented in the following applications: in-vehicle, Smartphone eco-driving, eco-routing and transportation simulation software to quantify the network-wide energy consumption levels for a fleet of EVs. One of the main advantages of EVs is their ability to recover energy while braking using a regenerative braking system. State-of-the-art vehicle energy consumption models consider an average constant regenerative braking energy efficiency or regenerative braking factors that are mainly dependent on the vehicle’s average
Modeling the viscoplastic and damage behavior in deep argillaceous rocks
International Nuclear Information System (INIS)
Souley, M.; Armand, G.; Su, K.; Ghoreychi, M.
2011-01-01
In order to demonstrate the feasibility of a radioactive waste repository in the Callovo-Oxfordian clay-stone formation, the French national radioactive waste management agency (ANDRA) started in 2000 to build an underground research laboratory at Bure (East of France). One of the key issues is to understand long term behavior of the drifts. More than 400 m horizontal galleries at the main level of -490 m have been instrumented since April 2005. The continuous measurements of convergence of the galleries are available, allowing a better understanding of the time-dependent response of the clay-stone at natural scale. Results indicate that the viscoplastic strain rates observed in the undamaged area far from the gallery walls are of the same order of magnitude as those obtained on rock samples, whereas those recorded in the damaged or fractured zone near the gallery walls are one to two orders of magnitude higher, indicating the significant influence of damage or/and macro-fractures on the viscoplastic strains. Based on these observations, a macroscopic viscoplastic model which aims to improve the viscoplastic strain prediction in the EDZ is proposed and implemented in FLAC 3Dc . Both the instantaneous and the time-dependent behavior are considered in the model. The short term response is assumed to be elastoplastic with strain hardening/softening whereas the time-dependent behavior is based on the concepts of visco-plasticity (Lemaitre's model). Finally, the damage-induced viscoplastic strains changes is examined through the plastic deformation (assumed to approach the damage rate).In order to verify both constitutive equations and their implementations, several simulations are performed: (a) triaxial tests at different confining pressures; (b) single- and multi-stage creep tests; (c) relaxation tests with different total axial strain levels, etc. Finally, an example of a blind prediction of the excavation of a drift parallel to the horizontal minor stress,
Modeling the viscoplastic and damage behavior in deep argillaceous rocks
Souley, Mountaka; Armand, Gilles; Su, Kun; Ghoreychi, Mehdi
In order to demonstrate the feasibility of a radioactive waste repository in the Callovo-Oxfordian claystone formation, the French national radioactive waste management agency (ANDRA) started in 2000 to build an underground research laboratory at Bure (East of France). One of the key issues is to understand long term behavior of the drifts. More than 400 m horizontal galleries at the main level of -490 m have been instrumented since April 2005. The continuous measurements of convergence of the galleries are available, allowing a better understanding of the time-dependent response of the claystone at natural scale. Results indicate that the viscoplastic strain rates observed in the undamaged area far from the gallery walls are of the same order of magnitude as those obtained on rock samples, whereas those recorded in the damaged or fractured zone near the gallery walls are one to two orders of magnitude higher, indicating the significant influence of damage or/and macro-fractures on the viscoplastic strains. Based on these observations, a macroscopic viscoplastic model which aims to improve the viscoplastic strain prediction in the EDZ is proposed and implemented in FLAC3 D©. Both the instantaneous and the time-dependent behavior are considered in the model. The short term response is assumed to be elactoplastic with strain hardening/softening whereas the time-dependent behavior is based on the concepts of viscoplasticity (Lemaıˆtre’s model). Finally, the damage-induced viscoplastic strains changes is examined through the plastic deformation (assumed to approach the damage rate). In order to verify both constitutive equations and their implementations, several simulations are performed: (a) triaxial tests at different confining pressures; (b) single- and multi-stage creep tests; (c) relaxation tests with different total axial strain levels, etc. Finally, an example of a blind prediction of the excavation of a drift parallel to the horizontal minor stress,
MERRA Chem 3D IAU Edge Pressure, Instantaneous 3-Hourly (eta coord, 2/3x1/2L73) V5.2.0
National Aeronautics and Space Administration — The MAI3NECHM or inst3_3d_chm_Ne data product is the MERRA Data Assimilation System Chemistry 3-Dimensional chemistry on layer Edges that is time averaged, 3D model...
Off-Gas Adsorption Model Capabilities and Recommendations
Energy Technology Data Exchange (ETDEWEB)
Lyon, Kevin L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Welty, Amy K. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Law, Jack [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ladshaw, Austin [Georgia Inst. of Technology, Atlanta, GA (United States); Yiacoumi, Sotira [Georgia Inst. of Technology, Atlanta, GA (United States); Tsouris, Costas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2016-03-01
Off-gas treatment is required to reduce emissions from aqueous fuel reprocessing. Evaluating the products of innovative gas adsorption research requires increased computational simulation capability to more effectively transition from fundamental research to operational design. Early modeling efforts produced the Off-Gas SeParation and REcoverY (OSPREY) model that, while efficient in terms of computation time, was of limited value for complex systems. However, the computational and programming lessons learned in development of the initial model were used to develop Discontinuous Galerkin OSPREY (DGOSPREY), a more effective model. Initial comparisons between OSPREY and DGOSPREY show that, while OSPREY does reasonably well to capture the initial breakthrough time, it displays far too much numerical dispersion to accurately capture the real shape of the breakthrough curves. DGOSPREY is a much better tool as it utilizes a more stable set of numerical methods. In addition, DGOSPREY has shown the capability to capture complex, multispecies adsorption behavior, while OSPREY currently only works for a single adsorbing species. This capability makes DGOSPREY ultimately a more practical tool for real world simulations involving many different gas species. While DGOSPREY has initially performed very well, there is still need for improvement. The current state of DGOSPREY does not include any micro-scale adsorption kinetics and therefore assumes instantaneous adsorption. This is a major source of error in predicting water vapor breakthrough because the kinetics of that adsorption mechanism is particularly slow. However, this deficiency can be remedied by building kinetic kernels into DGOSPREY. Another source of error in DGOSPREY stems from data gaps in single species, such as Kr and Xe, isotherms. Since isotherm data for each gas is currently available at a single temperature, the model is unable to predict adsorption at temperatures outside of the set of data currently
Extending Participatory Sensing to Personal Exposure Using Microscopic Land Use Regression Models.
Dekoninck, Luc; Botteldooren, Dick; Int Panis, Luc
2017-05-31
Personal exposure is sensitive to the personal features and behavior of the individual, and including interpersonal variability will improve the health and quality of life evaluations. Participatory sensing assesses the spatial and temporal variability of environmental indicators and is used to quantify this interpersonal variability. Transferring the participatory sensing information to a specific study population is a basic requirement for epidemiological studies in the near future. We propose a methodology to reduce the void between participatory sensing and health research. Instantaneous microscopic land-use regression modeling (µLUR) is an innovative approach. Data science techniques extract the activity-specific and route-sensitive spatiotemporal variability from the data. A data workflow to prepare and apply µLUR models to any mobile population is presented. The µLUR technique and data workflow are illustrated with models for exposure to traffic related Black Carbon. The example µLURs are available for three micro-environments; bicycle, in-vehicle, and indoor. Instantaneous noise assessments supply instantaneous traffic information to the µLURs. The activity specific models are combined into an instantaneous personal exposure model for Black Carbon. An independent external validation reached a correlation of 0.65. The µLURs can be applied to simulated behavioral patterns of individuals in epidemiological cohorts for advanced health and policy research.
Extending Participatory Sensing to Personal Exposure Using Microscopic Land Use Regression Models
Directory of Open Access Journals (Sweden)
Luc Dekoninck
2017-05-01
Full Text Available Personal exposure is sensitive to the personal features and behavior of the individual, and including interpersonal variability will improve the health and quality of life evaluations. Participatory sensing assesses the spatial and temporal variability of environmental indicators and is used to quantify this interpersonal variability. Transferring the participatory sensing information to a specific study population is a basic requirement for epidemiological studies in the near future. We propose a methodology to reduce the void between participatory sensing and health research. Instantaneous microscopic land-use regression modeling (µLUR is an innovative approach. Data science techniques extract the activity-specific and route-sensitive spatiotemporal variability from the data. A data workflow to prepare and apply µLUR models to any mobile population is presented. The µLUR technique and data workflow are illustrated with models for exposure to traffic related Black Carbon. The example µLURs are available for three micro-environments; bicycle, in-vehicle, and indoor. Instantaneous noise assessments supply instantaneous traffic information to the µLURs. The activity specific models are combined into an instantaneous personal exposure model for Black Carbon. An independent external validation reached a correlation of 0.65. The µLURs can be applied to simulated behavioral patterns of individuals in epidemiological cohorts for advanced health and policy research.
Hecksher, Tina; Olsen, Niels Boye; Dyre, Jeppe C
2017-04-21
This paper presents data for supercooled squalane's frequency-dependent shear modulus covering frequencies from 10 mHz to 30 kHz and temperatures from 168 K to 190 K; measurements are also reported for the glass phase down to 146 K. The data reveal a strong mechanical beta process. A model is proposed for the shear response of the metastable equilibrium liquid phase of supercooled liquids. The model is an electrical equivalent-circuit characterized by additivity of the dynamic shear compliances of the alpha and beta processes. The nontrivial parts of the alpha and beta processes are each represented by a "Cole-Cole retardation element" defined as a series connection of a capacitor and a constant-phase element, resulting in the Cole-Cole compliance function well-known from dielectrics. The model, which assumes that the high-frequency decay of the alpha shear compliance loss varies with the angular frequency as ω -1/2 , has seven parameters. Assuming time-temperature superposition for the alpha and beta processes separately, the number of parameters varying with temperature is reduced to four. The model provides a better fit to the data than an equally parametrized Havriliak-Negami type model. From the temperature dependence of the best-fit model parameters, the following conclusions are drawn: (1) the alpha relaxation time conforms to the shoving model; (2) the beta relaxation loss-peak frequency is almost temperature independent; (3) the alpha compliance magnitude, which in the model equals the inverse of the instantaneous shear modulus, is only weakly temperature dependent; (4) the beta compliance magnitude decreases by a factor of three upon cooling in the temperature range studied. The final part of the paper briefly presents measurements of the dynamic adiabatic bulk modulus covering frequencies from 10 mHz to 10 kHz in the temperature range from 172 K to 200 K. The data are qualitatively similar to the shear modulus data by having a significant beta process
Thermohaline circulation in the North Atlantic and its simulation with a box model
Averyanova, E. A.; Polonsky, A. B.; Sannikov, V. F.
2017-05-01
Features of the North Atlantic thermohaline circulation response to periodic, stochastic, and instantaneous forcing are studied using a four-box model. The present-day circulation is shown to be characterized by a stable quasi-periodic oscillatory mode that manifests itself as the Atlantic Multidecadal Oscillation. The thermohaline catastrophe is unlikely in the modern climate epoch.
Fitting the CDO correlation skew: a tractable structural jump-diffusion model
DEFF Research Database (Denmark)
Willemann, Søren
2007-01-01
allowing for instantaneous calibration to heterogeneous CDS curves and fast computation of CDO tranche spreads. We calibrate the model to CDX and iTraxx data from February 2007 and achieve a satisfactory fit. To price the senior tranches for both indices, we require a risk-neutral probability of a market...
Directory of Open Access Journals (Sweden)
Sergio Flores Pedroso
2006-01-01
Full Text Available Através da história do ensino de línguas não-maternas, a relação entre essa especialidade e a literatura tem sido favorecida por uma aprovação consensual cuja pertinência é questionada aqui. Tal aprovação se apresenta mais fincada no imaginário e na tradição do que em contribuições que a literatura realmente possa trazer para essa especialidade. Isso, considerando as prioridades a partir das quais as diversas teorias hoje atuantes no ensino de línguas não-maternas organizam o trabalho didático. Este trabalho discute a legitimação do funcionamento do literário nesse tipo de ensino porque considera que os próprios conceitos genéricos tradicionais de literatura com que ainda se opera não são consistentes com o que exige a prática pedagógica.Throughout the history of foreign language teaching, the relationship between literature and foreign language teaching has been assumed as pertinent. This paper questions that assumption and explains its consensual bases as supported more by the imagination and by the tradition than by the contributions that literature can bring to foreign language teaching. Considering the priorities at the foundations of the several theories that organize the didactic work, the own generic concepts of literature with which those theories work are not consistent with the pedagogic practice needs. This paper discusses a way of approach to literature having in view to meet those needs.
Directory of Open Access Journals (Sweden)
Yap Hoon
2017-02-01
Full Text Available In this paper, a refined reference current generation algorithm based on instantaneous power (pq theory is proposed, for operation of an indirect current controlled (ICC three-level neutral-point diode clamped (NPC inverter-based shunt active power filter (SAPF under non-sinusoidal source voltage conditions. SAPF is recognized as one of the most effective solutions to current harmonics due to its flexibility in dealing with various power system conditions. As for its controller, pq theory has widely been applied to generate the desired reference current due to its simple implementation features. However, the conventional dependency on self-tuning filter (STF in generating reference current has significantly limited mitigation performance of SAPF. Besides, the conventional STF-based pq theory algorithm is still considered to possess needless features which increase computational complexity. Furthermore, the conventional algorithm is mostly designed to suit operation of direct current controlled (DCC SAPF which is incapable of handling switching ripples problems, thereby leading to inefficient mitigation performance. Therefore, three main improvements are performed which include replacement of STF with mathematical-based fundamental real power identifier, removal of redundant features, and generation of sinusoidal reference current. To validate effectiveness and feasibility of the proposed algorithm, simulation work in MATLAB-Simulink and laboratory test utilizing a TMS320F28335 digital signal processor (DSP are performed. Both simulation and experimental findings demonstrate superiority of the proposed algorithm over the conventional algorithm.
Energy Technology Data Exchange (ETDEWEB)
Blandin, Christophe [Institut National Polytechnique, 38 - Grenoble (France)
1998-02-20
The objective of this work was conceiving and experimentally optimizing the SPNDs (Self-Powdered Neutron Detector) able to control fast power transients in test reactors and also to cope with requirements of surveillanceand protection of EDF reactors. Thus, different SPND emitters of platinum, gadolinium, hafnium and cobalt were provided according to their nature with sheathing and stainless steel plugs as well as with zirconium over-sheathing in order to render them faster, more selective and adapted for wear checking. Special experimental devices were designed for measuring inside the Siloe reactor the promptness of the signals from SPND, on one hand, and their sensitivity to thermal and epithermal neutrons as well as to gamma rays, on the other hand. The follow-up of power transients in test reactors is ensured by the instantaneous measurement of thermal and epithermal neutron flux as well as of gamma field by means of three special SPND with gadolinium, hafnium and platinum. Also, we have defined the characteristics of a new SPND with cobalt, that delivers a current of unique neutronic origin, able to ensure the surveillance and protection of a power reactor over a period of at least six years.
Tertre, E.; Hubert, F.; Bruzac, S.; Pacreau, M.; Ferrage, E.; Prêt, D.
2013-07-01
The present study aims at testing the validity of using an Na+/Ca2+ ion-exchange model, derived from batch data to interpret experimental Ca2+-for-Na+ exchange breakthrough curves obtained on vermiculite (a common swelling clay mineral in surface environments). The ion-exchange model was constructed considering the multi-site nature of the vermiculite surface as well as the exchange of all aqueous species (Mg2+ derived from the dissolution of the solid and H+). The proposed ion-exchange model was then coupled with a transport model, and the predicted breakthrough curves were compared with the experimental ones obtained using a well stirred flow-through reactor. For a given solute residence time in the reactor (typically 50 min), our thermodynamic model based on instantaneous equilibrium was found to accurately reproduce several of the experimental breakthrough curves, depending on the Na+ and Ca2+ concentrations of the influents pumped through the reactor. However the model failed to reproduce experimental breakthrough curves obtained at high flow rates and low chemical gradient between the exchanger phase and the solution. An alternative model based on a hybrid equilibrium/kinetic approach was thus used and allowed predicting experimental data. Based on these results, we show that a simple parameter can be used to differentiate between thermodynamic and kinetic control of the exchange reaction with water flow. The results of this study are relevant for natural systems where two aquatic environments having contrasted chemistries interact. Indeed, the question regarding the attainment of a full equilibrium in such a system during the contact time of the aqueous phase with the particle/colloid remains most often open. In this context, we show that when a river (a flow of fresh water) encounters marine colloids, a systematic full equilibrium can be assumed (i.e., the absence of kinetic effects) when the residence time of the solute in 1 m3 of the system is ⩾6200 h.
Application of instantaneous spectral analysis and acoustic ...
Indian Academy of Sciences (India)
44
Institute of geophysics and geomatics, China University of Geosciences, Wuhan, China. 6. ¹. {mtayyab.naseer1} .... hydrocarbon-bearing sands, for example, sand point bars, crevasse splays, and barrier bars, sand. 53 .... underway the exploration activity of the Miano gas field in 1993 with the discovery of a natural. 95.
Stride length: measuring its instantaneous value
International Nuclear Information System (INIS)
Campiglio, G C; Mazzeo, J R
2007-01-01
Human gait has been studied from different viewpoints: kinematics, dynamics, sensibility and others. Many of its characteristics still remain open to research, both for normal gait and for pathological gait. Objective measures of some of its most significant spatial/temporal parameters are important in this context. Stride length, one of these parameters, is defined as the distance between two consecutive contacts of one foot with ground. On this work we present a device designed to provide automatic measures of stride length. Its features make it particularly appropriate for the evaluation of pathological gait
Instantaneous frequencies of a chaotic system
Indian Academy of Sciences (India)
Time–frequency analysis; wavelets; Hamiltonian systems. PACS Nos 05.45.-a; 32.80.Rm. 1. Introduction ... Aix-Marseille II et du Sud Toulon-Var. Laboratoire affilié `a la FRUMAM (FR 2291). ... time–frequency analysis of signals, of which the wavelet transform is but one exam- ple [2], form the corner-stone of our method.
Estimating Instantaneous Energetic Cost During Gait Adaptation
2014-08-31
energetic penalties imposed by various gait disabilities, and the 30 evaluation of the effectiveness of rehabilitation interventions at mitigating...Jarasch R. Energy expenditure and biomechanical characteristics of 412 lower limb amputee gait:: The influence of prosthetic alignment and
Instantaneous frequencies of a chaotic system
Indian Academy of Sciences (India)
fined as ridges of the time–frequency landscape. Using the wavelet transform of a single trajectory, it can characterize key dynamical properties like the extent of chaos, resonance transitions and trappings. Keywords. Time–frequency analysis; wavelets; Hamiltonian systems. PACS Nos 05.45.-a; 32.80.Rm. 1. Introduction.
Structural relaxation monitored by instantaneous shear modulus
DEFF Research Database (Denmark)
Olsen, Niels Boye; Dyre, Jeppe; Christensen, Tage Emil
1998-01-01
time definition based on a recently proposed expression for the relaxation time, where G [infinity] reflects the fictive temperature. All parameters entering the reduced time were determined from independent measurements of the frequency-dependent shear modulus of the equilibrium liquid....
Energy Technology Data Exchange (ETDEWEB)
Shankaran, Harish, E-mail: harish.shankaran@pnnl.gov [Computational Biology and Bioinformatics Group, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Adeshina, Femi [National Homeland Security Research Center, United States Environmental Protection Agency, Washington, DC 20460 (United States); Teeguarden, Justin G. [Systems Toxicology Group, Pacific Northwest National Laboratory, Richland, WA 99352 (United States)
2013-12-15
Provisional Advisory Levels (PALs) are tiered exposure limits for toxic chemicals in air and drinking water that are developed to assist in emergency responses. Physiologically-based pharmacokinetic (PBPK) modeling can support this process by enabling extrapolations across doses, and exposure routes, thereby addressing gaps in the available toxicity data. Here, we describe the development of a PBPK model for Fentanyl – a synthetic opioid used clinically for pain management – to support the establishment of PALs. Starting from an existing model for intravenous Fentanyl, we first optimized distribution and clearance parameters using several additional IV datasets. We then calibrated the model using pharmacokinetic data for various formulations, and determined the absorbed fraction, F, and time taken for the absorbed amount to reach 90% of its final value, t90. For aerosolized pulmonary Fentanyl, F = 1 and t90 < 1 min indicating complete and rapid absorption. The F value ranged from 0.35 to 0.74 for oral and various transmucosal routes. Oral Fentanyl was absorbed the slowest (t90 ∼ 300 min); the absorption of intranasal Fentanyl was relatively rapid (t90 ∼ 20–40 min); and the various oral transmucosal routes had intermediate absorption rates (t90 ∼ 160–300 min). Based on these results, for inhalation exposures, we assumed that all of the Fentanyl inhaled from the air during each breath directly, and instantaneously enters the arterial circulation. We present model predictions of Fentanyl blood concentrations in oral and inhalation scenarios relevant for PAL development, and provide an analytical expression that can be used to extrapolate between oral and inhalation routes for the derivation of PALs. - Highlights: • We develop a Fentanyl PBPK model for relating external dose to internal levels. • We calibrate the model to oral and inhalation exposures using > 50 human datasets. • Model predictions are in good agreement with the available
Energy Technology Data Exchange (ETDEWEB)
Comins, H.N.; McMurtrie, R.E. (Univ. of New South Wales, Kensington (Australia))
1993-11-01
Established process-based models of forest biomass production in relation to atmospheric CO[sub 2] concentration (McMurtrie 1991) and soil carbon/nutrient dynamics (Parton et al. 1987) are integrated to derive the [open quotes]Generic Decomposition and Yield[close quotes] model (G'DAY). The model is used to describe how photosynthesis and nutritional factors interact to determine the productivity of forest growing under nitrogen-limited conditions. A simulated instantaneous doubling of atmospheric CO[sub 2] concentration lead to a growth response that is initially large (27% above productivity at current CO[sub 2]) but declines to <10% elevation within 5 yr. The decline occurs because increases in photosynthetic carbon gain at elevated CO[sub 2] are not matched by increases in nutrient supply. Lower foliar N concentrations at elevated CO[sub 2] have two countervailing effects on forest production: decreased rates of N cycling between vegetation and soils (with negative consequences for productivity), and reduced rates of N loss through gaseous emission, fire, and leaching. Theoretical analysis reveals that there is an enduring response to CO[sub 2] enrichment, but that the magnitude of the long-term equilibrium response is extremely sensitive to the assumed rate of gaseous emission resulting from mineralization of nitrogen. Theory developed to analyze G'DAY is applicable to other published production-decomposition models describing the partitioning of soil carbon among compartments with widely differing decay-time constants. 37 refs., 9 figs., 2 tabs.
Numerical modelling of landscape and sediment flux response to precipitation rate change
Directory of Open Access Journals (Sweden)
J. J. Armitage
2018-02-01
Full Text Available Laboratory-scale experiments of erosion have demonstrated that landscapes have a natural (or intrinsic response time to a change in precipitation rate. In the last few decades there has been growth in the development of numerical models that attempt to capture landscape evolution over long timescales. However, there is still an uncertainty regarding the validity of the basic assumptions of mass transport that are made in deriving these models. In this contribution we therefore return to a principal assumption of sediment transport within the mass balance for surface processes; we explore the sensitivity of the classic end-member landscape evolution models and the sediment fluxes they produce to a change in precipitation rates. One end-member model takes the mathematical form of a kinetic wave equation and is known as the stream power model, in which sediment is assumed to be transported immediately out of the model domain. The second end-member model is the transport model and it takes the form of a diffusion equation, assuming that the sediment flux is a function of the water flux and slope. We find that both of these end-member models have a response time that has a proportionality to the precipitation rate that follows a negative power law. However, for the stream power model the exponent on the water flux term must be less than one, and for the transport model the exponent must be greater than one, in order to match the observed concavity of natural systems. This difference in exponent means that the transport model generally responds more rapidly to an increase in precipitation rates, on the order of 105 years for post-perturbation sediment fluxes to return to within 50 % of their initial values, for theoretical landscapes with a scale of 100×100 km. Additionally from the same starting conditions, the amplitude of the sediment flux perturbation in the transport model is greater, with much larger sensitivity to catchment size. An
Numerical modelling of landscape and sediment flux response to precipitation rate change
Armitage, John J.; Whittaker, Alexander C.; Zakari, Mustapha; Campforts, Benjamin
2018-02-01
Laboratory-scale experiments of erosion have demonstrated that landscapes have a natural (or intrinsic) response time to a change in precipitation rate. In the last few decades there has been growth in the development of numerical models that attempt to capture landscape evolution over long timescales. However, there is still an uncertainty regarding the validity of the basic assumptions of mass transport that are made in deriving these models. In this contribution we therefore return to a principal assumption of sediment transport within the mass balance for surface processes; we explore the sensitivity of the classic end-member landscape evolution models and the sediment fluxes they produce to a change in precipitation rates. One end-member model takes the mathematical form of a kinetic wave equation and is known as the stream power model, in which sediment is assumed to be transported immediately out of the model domain. The second end-member model is the transport model and it takes the form of a diffusion equation, assuming that the sediment flux is a function of the water flux and slope. We find that both of these end-member models have a response time that has a proportionality to the precipitation rate that follows a negative power law. However, for the stream power model the exponent on the water flux term must be less than one, and for the transport model the exponent must be greater than one, in order to match the observed concavity of natural systems. This difference in exponent means that the transport model generally responds more rapidly to an increase in precipitation rates, on the order of 105 years for post-perturbation sediment fluxes to return to within 50 % of their initial values, for theoretical landscapes with a scale of 100×100 km. Additionally from the same starting conditions, the amplitude of the sediment flux perturbation in the transport model is greater, with much larger sensitivity to catchment size. An important finding is that
Tectonic predictions with mantle convection models
Coltice, Nicolas; Shephard, Grace E.
2018-04-01
Over the past 15 yr, numerical models of convection in Earth's mantle have made a leap forward: they can now produce self-consistent plate-like behaviour at the surface together with deep mantle circulation. These digital tools provide a new window into the intimate connections between plate tectonics and mantle dynamics, and can therefore be used for tectonic predictions, in principle. This contribution explores this assumption. First, initial conditions at 30, 20, 10 and 0 Ma are generated by driving a convective flow with imposed plate velocities at the surface. We then compute instantaneous mantle flows in response to the guessed temperature fields without imposing any boundary conditions. Plate boundaries self-consistently emerge at correct locations with respect to reconstructions, except for small plates close to subduction zones. As already observed for other types of instantaneous flow calculations, the structure of the top boundary layer and upper-mantle slab is the dominant character that leads to accurate predictions of surface velocities. Perturbations of the rheological parameters have little impact on the resulting surface velocities. We then compute fully dynamic model evolution from 30 and 10 to 0 Ma, without imposing plate boundaries or plate velocities. Contrary to instantaneous calculations, errors in kinematic predictions are substantial, although the plate layout and kinematics in several areas remain consistent with the expectations for the Earth. For these calculations, varying the rheological parameters makes a difference for plate boundary evolution. Also, identified errors in initial conditions contribute to first-order kinematic errors. This experiment shows that the tectonic predictions of dynamic models over 10 My are highly sensitive to uncertainties of rheological parameters and initial temperature field in comparison to instantaneous flow calculations. Indeed, the initial conditions and the rheological parameters can be good enough
Konrad, Wilfried; Katul, Gabriel; Roth-Nebelsick, Anita; Grein, Michaela
2017-06-01
To address questions related to the acceleration or deceleration of the global hydrological cycle or links between the carbon and water cycles over land, reliable data for past climatic conditions based on proxies are required. In particular, the reconstruction of palaeoatmospheric CO2 content (Ca) is needed to assist the separation of natural from anthropogenic Ca variability and to explore phase relations between Ca and air temperature Ta time series. Both Ta and Ca are needed to fingerprint anthropogenic signatures in vapor pressure deficit, a major driver used to explain acceleration or deceleration phases in the global hydrological cycle. Current approaches to Ca reconstruction rely on a robust inverse correlation between measured stomatal density in leaves (ν) of many plant taxa and Ca. There are two methods that exploit this correlation: The first uses calibration curves obtained from extant species assumed to represent the fossil taxa, thereby restricting the suitable taxa to those existing today. The second is a hybrid eco-hydrological/physiological approach that determines Ca with the aid of systems of equations based on quasi-instantaneous leaf-gas exchange theories and fossil stomatal data collected along with other measured leaf anatomical traits and parameters. In this contribution, a reduced order model (ROM) is proposed that derives Ca from a single equation incorporating the aforementioned stomatal data, basic climate (e.g. temperature), estimated biochemical parameters of assimilation and isotope data. The usage of the ROM is then illustrated by applying it to isotopic and anatomical measurements from three extant species. The ROM derivation is based on a balance between the biochemical demand and atmospheric supply of CO2 that leads to an explicit expression linking stomatal conductance to internal CO2 concentration (Ci) and Ca. The resulting expression of stomatal conductance from the carbon economy of the leaf is then equated to another
The nontopological soliton model
International Nuclear Information System (INIS)
Wilets, L.
1988-01-01
The nontopological soliton model introduced by Friedberg and Lee, and variations of it, provide a method for modeling QCD which can effectively include the dynamics of hadronic collisions as well as spectra. Absolute color confinement is effected by the assumed dielectric properties of the medium. A recently proposed version of the model is chirally invariant. 32 refs., 5 figs., 1 tab
Alvin, Zikiar; Laurence, Graham G.; Coleman, Bernell R.; Zhao, Aiqiu; Hajj-Moussa, Majd; Haddad, Georges E.
2011-01-01
Summary Background Early development of cardiac hypertrophy may be beneficial but sustained hypertrophic activation leads to myocardial dysfunction. Regulation of the repolarizing currents can be modulated by the activation of humoral factors, such as angiotensin II (ANG II) through protein kinases. The aim of this work is to assess the regulation of IK and IK1 by ANG II through the PI3-K pathway in hypertrophied ventricular myocytes. Material/Methods Cardiac eccentric hypertrophy was induced through volume-overload in adult male rats by aorto-caval shunt (3 weeks). After one week half of the rats were given captopril (2 weeks; 0.5 g/l/day) and the other half served as control. The voltage-clamp and western blot techniques were used to measure the delayed outward rectifier potassium current (IK) and the instantaneous inward rectifier potassium current (IK1) and Akt activity, respectively. Results Hypertrophied cardiomyocytes showed reduction in IK and IK1. Treatment with captopril alleviated this difference seen between sham and shunt cardiomyocytes. Acute administration of ANG II (10−6M) to cardiocytes treated with captopril reduced IK and IK1 in shunts, but not in sham. Captopril treatment reversed ANG II effects on IK and IK1 in a PI3-K-independent manner. However in the absence of angiotensin converting enzyme inhibition, ANG II increased both IK and IK1 in a PI3-K-dependent manner in hypertrophied cardiomyocytes. Conclusions Thus, captopril treatment reveals a negative effect of ANG II on IK and IK1, which is PI3-K independent, whereas in the absence of angiotensin converting enzyme inhibition IK and IK1 regulation is dependent upon PI3-K. PMID:21709626
Ansheles, A A; Sergienko, B V; Darenskiy, I D; Gramovich, V V; Zharova, A E; Mitroshkin, G M; Matchin, G Y; Atanesyan, V R
2017-08-01
To compare the diagnostic accuracy of instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) with noninvasive methods in assessment of the functional significance of moderate coronary stenoses in patients with chronic ischemic heart disease (IHD). We included in this study 50 patients with chronic or suspected IHD and moderate coronary stenoses (50-70%; 74 stenoses). Values of iFR and FFR were determined within 10 days after noninvasive stress tests (combination of stress-echo and SPECT). The values of iFR and FFR were compared with the results of noninvasive methods by ROC-analysis. Coronary artery stenosis was considered functionally important if at least one of noninvasive tests (stress-echo or SPECT) demonstrated positive result. The results of noninvasive stress-tests were positive in 14 patients (28%). ROC area under the curve (AUC) for iFR - 0.961±0.019 (95%CI 0.888-0.992). The best cut-off point for iFR is 0.92 (sensitivity 100, specificity 84%). ROC AUC for FFR - 0.893±0.041 (95%CI 0.79-0.96). The best cut-off point for FFR is 0.81 (sensitivity 100% and specificity 69%). There was no significant difference between iFR and FFR ROC-curves (р=0.0845). The values of iFR and FFR have equivalent agreement with the results of noninvasive tests commonly used to detect myocardial ischemia in patients with moderate coronary stenoses.
Directory of Open Access Journals (Sweden)
Johann F Petit Suárez
2011-06-01
Full Text Available En este artículo se propone un algoritmo basado en filtros sintonizados para extraer las componentes instantáneas de secuencia positiva, negativa y cero (+,-,0 de señales de tensión y/o corrientes desequilibradas y distorsionadas. El trabajo se encuentra justificado en la necesidad de disponer de nuevos algoritmos que puedan ser utilizados en la medición de parámetros que afectan a la calidad de la energía eléctrica con el fin de diagnosticar y compensar las perturbaciones presentes en las señales de tensión y/o corriente. El desempeño del algoritmo es evaluado mediante simulaciones en Matlab/Simulink y por medio de su implementación en tiempo real en la tarjeta de desarrollo dSPACE 1104. Los resultados obtenidos muestran la eficacia del algoritmo propuesto.In this paper a new algorithm based on tuned filters to extract the positive, negative and zero sequence instantaneous components of distorted and unbalanced electrical signals is shown. The new algorithm can be used in applications such as signal parameter estimation, power quality analysis and it can be useful for estimating the reference signal of some compensation devices used to improve the power quality. The algorithm performance is evaluated by simulations in Matlab/Simulink and through its implementation in real time on a dSPACE 1104 development board. In addition, the experimental setup results show an outstanding performance.
Modelling an advanced ManPAD with dual band detectors and a rosette scanning seeker head
Birchenall, Richard P.; Richardson, Mark A.; Butters, Brian; Walmsley, Roy
2012-01-01
Man Portable Air Defence Systems (ManPADs) have been a favoured anti aircraft weapon since their appearance on the military proliferation scene in the mid 1960s. Since this introduction there has been a 'cat and mouse' game of Missile Countermeasures (CMs) and the aircraft protection counter counter measures (CCMs) as missile designers attempt to defeat the aircraft platform protection equipment. Magnesium Teflon Viton (MTV) flares protected the target aircraft until the missile engineers discovered the art of flare rejection using techniques including track memory and track angle bias. These early CCMs relied upon CCM triggering techniques such as the rise rate method which would just sense a sudden increase in target energy and assume that a flare CM had been released by the target aircraft. This was not as reliable as was first thought as aspect changes (bringing another engine into the field of view) or glint from the sun could inadvertently trigger a CCM when not needed. The introduction of dual band detectors in the 1980s saw a major advance in CCM capability allowing comparisons between two distinct IR bands to be made thus allowing the recognition of an MTV flare to occur with minimal false alarms. The development of the rosette scan seeker in the 1980s complemented this advancement allowing the scene in the missile field of view (FOV) to be scanned by a much smaller (1/25) instantaneous FOV (IFOV) with the spectral comparisons being made at each scan point. This took the ManPAD from a basic IR energy detector to a pseudo imaging system capable of analysing individual elements of its overall FOV allowing more complex and robust CCM to be developed. This paper continues the work published in [1,2] and describes the method used to model an advanced ManPAD with a rosette scanning seeker head and robust CCMs similar to the Raytheon Stinger RMP.
Uffmann, Kai; Gruetter, Rolf
2007-11-15
A novel approach for the mathematical modeling of (13)C label incorporation into amino acids via the TCA cycle that eliminates the explicit calculation of the labeling of the TCA cycle intermediates is described, resulting in one differential equation per measurable time course of labeled amino acid. The equations demonstrate that both glutamate C4 and C3 labeling depend in a predictable manner on both transmitochondrial exchange rate, V(X), and TCA cycle rate, V(TCA). For example, glutamate C4 labeling alone does not provide any information on either V(X) or V(TCA) but rather a composite "flux". Interestingly, glutamate C3 simultaneously receives label not only from pyruvate C3 but also from glutamate C4, described by composite precursor functions that depend in a probabilistic way on the ratio of V(X) to V(TCA): An initial rate of labeling of glutamate C3 (or C2) being close to zero is indicative of a high V(X)/V(TCA). The derived analytical solution of these equations shows that, when the labeling of the precursor pool pyruvate reaches steady state quickly compared with the turnover rate of the measured amino acids, instantaneous labeling can be assumed for pyruvate. The derived analytical solution has acceptable errors compared with experimental uncertainty, thus obviating precise knowledge on the labeling kinetics of the precursor. In conclusion, a substantial reformulation of the modeling of label flow via the TCA cycle turnover into the amino acids is presented in the current study. This approach allows one to determine metabolic rates by fitting explicit mathematical functions to measured time courses.
A realistic model for quantum theory with a locality property
International Nuclear Information System (INIS)
Eberhard, P.H.
1987-04-01
A model reproducing the predictions of relativistic quantum theory to any desired degree of accuracy is described in this paper. It involves quantities that are independent of the observer's knowledge, and therefore can be called real, and which are defined at each point in space, and therefore can be called local in a rudimentary sense. It involves faster-than-light, but not instantaneous, action at distance
Immune Response to Electromagnetic Fields through Cybernetic Modeling
Godina-Nava, J. J.; Segura, M. A. Rodríguez; Cadena, S. Reyes; Sierra, L. C. Gaitán
2008-08-01
We study the optimality of the humoral immune response through a mathematical model, which involves the effect of electromagnetic fields over the large lymphocytes proliferation. Are used the so called cybernetic variables in the context of the matching law of microeconomics or mathematical psychology, to measure the large lymphocytes population and to maximize the instantaneous antibody production rate in time during the immunologic response in order to most efficiently inactivate the antigen.
Immune Response to Electromagnetic Fields through Cybernetic Modeling
International Nuclear Information System (INIS)
Godina-Nava, J. J.; Segura, M. A. Rodriguez; Cadena, S. Reyes; Sierra, L. C. Gaitan
2008-01-01
We study the optimality of the humoral immune response through a mathematical model, which involves the effect of electromagnetic fields over the large lymphocytes proliferation. Are used the so called cybernetic variables in the context of the matching law of microeconomics or mathematical psychology, to measure the large lymphocytes population and to maximize the instantaneous antibody production rate in time during the immunologic response in order to most efficiently inactivate the antigen
COTHERM: Modelling fluid-rock interactions in Icelandic geothermal systems
Thien, Bruno; Kosakowski, Georg; Kulik, Dmitrii
2014-05-01
Mineralogical alteration of reservoir rocks, driven by fluid circulation in natural or enhanced geothermal systems, is likely to influence the long-term performance of geothermal power generation. A key factor is the change of porosity due to dissolution of primary minerals and precipitation of secondary phases. Porosity changes will affect fluid circulation and solute transport, which, in turn, influence mineralogical alteration. This study is part of the Sinergia COTHERM project (COmbined hydrological, geochemical and geophysical modeling of geotTHERMal systems) that is an integrative research project aimed at improving our understanding of the sub-surface processes in magmatically-driven natural geothermal systems. We model the mineralogical and porosity evolution of Icelandic geothermal systems with 1D and 2D reactive transport models. These geothermal systems are typically high enthalphy systems where a magmatic pluton is located at a few kilometers depth. The shallow plutons increase the geothermal gradient and trigger the circulation of hydrothermal waters with a steam cap forming at shallow depth. We investigate two contrasting geothermal systems: Krafla, for which the water recharge consists of meteoritic water; and Reykjanes, for which the water recharge mainly consists of seawater. The initial rock composition is a fresh basalt. We use the GEM-Selektor geochemical modeling package [1] for calculation of kinetically controlled mineral equilibria between the rock and the ingression water. We consider basalt minerals dissolution kinetics according to Palandri & Kharaka [2]. Reactive surface areas are assumed to be geometric surface areas, and are corrected using a spherical-particle surface/mass relationship. For secondary minerals, we consider the partial equilibrium assuming that the primary mineral dissolution is slow, and the secondary mineral precipitation is fast. Comparison of our modeling results with the mineralogical assemblages observed in the
Modeling Earth's surface topography: decomposition of the static and dynamic components
Guerri, M.; Cammarano, F.; Tackley, P. J.
2017-12-01
Isolating the portion of topography supported by mantle convection, the so-called dynamic topography, would give us precious information on vigor and style of the convection itself. Contrasting results on the estimate of dynamic topography motivate us to analyse the sources of uncertainties affecting its modeling. We obtain models of mantle and crust density, leveraging on seismic and mineral physics constraints. We use the models to compute isostatic topography and residual topography maps. Estimates of dynamic topography and associated synthetic geoid are obtained by instantaneous mantle flow modeling. We test various viscosity profiles and 3D viscosity distributions accounting for inferred lateral variations in temperature. We find that the patterns of residual and dynamic topography are robust, with an average correlation coefficient of 0.74 and 0.71, respectively. The amplitudes are however poorly constrained. For the static component, the considered lithospheric mantle density models result in topographies that differ, on average, 720 m, with peaks reaching 1.7 km. The crustal density models produce variations in isostatic topography averaging 350 m, with peaks of 1 km. For the dynamic component, we obtain peak-to-peak topography amplitude exceeding 3 km for all the tested mantle density and viscosity models. Such values of dynamic topography produce geoid undulations that are not in agreement with observations. Assuming chemical heterogeneities in the lower mantle, in correspondence with the LLSVPs (Large Low Shear wave Velocity Provinces), helps to decrease the amplitudes of dynamic topography and geoid, but reduces the correlation between synthetic and observed geoid. The correlation coefficients between the residual and dynamic topography maps is always less than 0.55. In general, our results indicate that, i) current knowledge of crust density, mantle density and mantle viscosity is still limited, ii) it is important to account for all the various
Ku, Jerry C.; Tong, Li; Greenberg, Paul S.
1996-01-01
This is a computational and experimental study for soot formation and radiative heat transfer in jet diffusion flames under normal gravity (1-g) and microgravity (0-g) conditions. Instantaneous soot volume fraction maps are measured using a full-field imaging absorption technique developed by the authors. A compact, self-contained drop rig is used for microgravity experiments in the 2.2-second drop tower facility at NASA Lewis Research Center. On modeling, we have coupled flame structure and soot formation models with detailed radiation transfer calculations. Favre-averaged boundary layer equations with a k-e-g turbulence model are used to predict the flow field, and a conserved scalar approach with an assumed Beta-pdf are used to predict gaseous species mole fraction. Scalar transport equations are used to describe soot volume fraction and number density distributions, with formation and oxidation terms modeled by one-step rate equations and thermophoretic effects included. An energy equation is included to couple flame structure and radiation analyses through iterations, neglecting turbulence-radiation interactions. The YIX solution for a finite cylindrical enclosure is used for radiative heat transfer calculations. The spectral absorption coefficient for soot aggregates is calculated from the Rayleigh solution using complex refractive index data from a Drude- Lorentz model. The exponential-wide-band model is used to calculate the spectral absorption coefficient for H20 and C02. It is shown that when compared to results from true spectral integration, the Rosseland mean absorption coefficient can provide reasonably accurate predictions for the type of flames studied. The soot formation model proposed by Moss, Syed, and Stewart seems to produce better fits to experimental data and more physically sound than the simpler model by Khan et al. Predicted soot volume fraction and temperature results agree well with published data for a normal gravity co-flow laminar
A simulation of water pollution model parameter estimation
Kibler, J. F.
1976-01-01
A parameter estimation procedure for a water pollution transport model is elaborated. A two-dimensional instantaneous-release shear-diffusion model serves as representative of a simple transport process. Pollution concentration levels are arrived at via modeling of a remote-sensing system. The remote-sensed data are simulated by adding Gaussian noise to the concentration level values generated via the transport model. Model parameters are estimated from the simulated data using a least-squares batch processor. Resolution, sensor array size, and number and location of sensor readings can be found from the accuracies of the parameter estimates.
Spädtke, P
2013-01-01
Modeling of technical machines became a standard technique since computer became powerful enough to handle the amount of data relevant to the specific system. Simulation of an existing physical device requires the knowledge of all relevant quantities. Electric fields given by the surrounding boundary as well as magnetic fields caused by coils or permanent magnets have to be known. Internal sources for both fields are sometimes taken into account, such as space charge forces or the internal magnetic field of a moving bunch of charged particles. Used solver routines are briefly described and some bench-marking is shown to estimate necessary computing times for different problems. Different types of charged particle sources will be shown together with a suitable model to describe the physical model. Electron guns are covered as well as different ion sources (volume ion sources, laser ion sources, Penning ion sources, electron resonance ion sources, and H$^-$-sources) together with some remarks on beam transport.
The emission factor of volatile isoprenoids: caveats, model algorithms, response shapes and scaling
Niinemets, Ü.; Monson, R. K.; Arneth, A.; Ciccioli, P.; Kesselmeier, J.; Kuhn, U.; Noe, S. M.; Peñuelas, J.; Staudt, M.
2010-02-01
In models of plant volatile isoprenoid emissions, the instantaneous compound emission rate typically scales with the plant's emission capacity under specified environmental conditions, also defined as the emission factor, ES. In the most widely employed plant isoprenoid emission models, the algorithms developed by Guenther and colleagues (1991, 1993), instantaneous variation of the steady-state emission rate is described as the product of ES and light and temperature response functions. When these models are employed in the in atmospheric chemistry modeling community, species-specific ES values and parameter values defining the instantaneous response curves are typically considered as constant. In the current review, we argue that ES is largely a modeling concept, importantly depending on our understanding of which environmental factors affect isoprenoid emissions, and consequently need standardization during ES determination. In particular, there is now increasing consensus that variations in atmospheric CO2 concentration, in addition to variations in light and temperature, need to be included in the emission models. Furthermore, we demonstrate that for less volatile isoprenoids, mono- and sesquiterpenes, the emissions are often jointly controlled by the compound synthesis and volatility, and because of these combined biochemical and physico-chemical properties, specification of ES as a constant value is incapable of describing instantaneous emissions within the sole assumptions of fluctuating light and temperature, as are used in the standard algorithms. The definition of ES also varies depending on the degree of aggregation of ES values in different parameterization schemes (leaf- vs. canopy- or region-level, species vs. plant functional type level), and various aggregated ES schemes are not compatible for different integration models. The summarized information collectively emphasizes the need to update model algorithms by including missing environmental and
Niinemets, Ü.; Monson, R. K.; Arneth, A.; Ciccioli, P.; Kesselmeier, J.; Kuhn, U.; Noe, S. M.; Peñuelas, J.; Staudt, M.
2010-06-01
In models of plant volatile isoprenoid emissions, the instantaneous compound emission rate typically scales with the plant's emission potential under specified environmental conditions, also called as the emission factor, ES. In the most widely employed plant isoprenoid emission models, the algorithms developed by Guenther and colleagues (1991, 1993), instantaneous variation of the steady-state emission rate is described as the product of ES and light and temperature response functions. When these models are employed in the atmospheric chemistry modeling community, species-specific ES values and parameter values defining the instantaneous response curves are often taken as initially defined. In the current review, we argue that ES as a characteristic used in the models importantly depends on our understanding of which environmental factors affect isoprenoid emissions, and consequently need standardization during experimental ES determinations. In particular, there is now increasing consensus that in addition to variations in light and temperature, alterations in atmospheric and/or within-leaf CO2 concentrations may need to be included in the emission models. Furthermore, we demonstrate that for less volatile isoprenoids, mono- and sesquiterpenes, the emissions are often jointly controlled by the compound synthesis and volatility. Because of these combined biochemical and physico-chemical drivers, specification of ES as a constant value is incapable of describing instantaneous emissions within the sole assumptions of fluctuating light and temperature as used in the standard algorithms. The definition of ES also varies depending on the degree of aggregation of ES values in different parameterization schemes (leaf- vs. canopy- or region-scale, species vs. plant functional type levels) and various aggregated ES schemes are not compatible for different integration models. The summarized information collectively emphasizes the need to update model algorithms by including
From spiking neuron models to linear-nonlinear models.
Directory of Open Access Journals (Sweden)
Srdjan Ostojic
Full Text Available Neurons transform time-varying inputs into action potentials emitted stochastically at a time dependent rate. The mapping from current input to output firing rate is often represented with the help of phenomenological models such as the linear-nonlinear (LN cascade, in which the output firing rate is estimated by applying to the input successively a linear temporal filter and a static non-linear transformation. These simplified models leave out the biophysical details of action potential generation. It is not a priori clear to which extent the input-output mapping of biophysically more realistic, spiking neuron models can be reduced to a simple linear-nonlinear cascade. Here we investigate this question for the leaky integrate-and-fire (LIF, exponential integrate-and-fire (EIF and conductance-based Wang-Buzsáki models in presence of background synaptic activity. We exploit available analytic results for these models to determine the corresponding linear filter and static non-linearity in a parameter-free form. We show that the obtained functions are identical to the linear filter and static non-linearity determined using standard reverse correlation analysis. We then quantitatively compare the output of the corresponding linear-nonlinear cascade with numerical simulations of spiking neurons, systematically varying the parameters of input signal and background noise. We find that the LN cascade provides accurate estimates of the firing rates of spiking neurons in most of parameter space. For the EIF and Wang-Buzsáki models, we show that the LN cascade can be reduced to a firing rate model, the timescale of which we determine analytically. Finally we introduce an adaptive timescale rate model in which the timescale of the linear filter depends on the instantaneous firing rate. This model leads to highly accurate estimates of instantaneous firing rates.
Analytical Model for Hook Anchor Pull-Out
DEFF Research Database (Denmark)
Brincker, Rune; Ulfkjær, Jens Peder; Adamsen, Peter
1995-01-01
A simple analytical model for the pull-out of a hook anchor is presented. The model is based on a simplified version of the fictitious crack model. It is assumed that the fracture process is the pull-off of a cone shaped concrete part, simplifying the problem by assuming pure rigid body motions...
Analytical Model for Hook Anchor Pull-out
DEFF Research Database (Denmark)
Brincker, Rune; Ulfkjær, J. P.; Adamsen, P.
A simple analytical model for the pull-out of a hook anchor is presented. The model is based on a simplified version of the fictitious crack model. It is assumed that the fracture process is the pull-off of a cone shaped concrete part, simplifying the problem by assuming pure rigid body motions...
Conformally flat tilted Bianchi Type-V cosmological models in ...
Indian Academy of Sciences (India)
the complete determination of these quantities, we assume two extra conditions. First we assume that the space-time is conformally flat which leads to. 1008 .... Discussions. The model starts expanding with a big-bang at М = 0 and the expansion in the model stops at М = ∞ and = -2(Т + 2)¬. The model in general represents.
Acharya, Ranadip; Bansal, Rohan; Gambone, Justin J.; Das, Suman
2014-12-01
Scanning laser epitaxy (SLE) is a new laser-based additive manufacturing technology under development at the Georgia Institute of Technology. SLE is aimed at the creation of equiaxed, directionally solidified, and single-crystal deposits of nickel-based superalloys through the melting of alloy powders onto superalloy substrates using a fast scanning Nd:YAG laser beam. The fast galvanometer control movement of the laser (0.2 to 2 m/s) and high-resolution raster scanning (20 to 200 µm line spacing) enables superior thermal control over the solidification process and allows the production of porosity-free, crack-free deposits of more than 1000 µm thickness. Here, we present a combined thermal and fluid flow model of the SLE process applied to alloy CMSX-4 with temperature-dependent thermo-physical properties. With the scanning beam described as a moving line source, the instantaneous melt pool assumes a convex hull shape with distinct leading edge and trailing edge characteristics. Temperature gradients at the leading and trailing edges are of order 2 × 105 and 104 K/m, respectively. Detailed flow analysis provides insights on the flow characteristics of the powder incorporating into the melt pool, showing velocities of order 1 × 10-4 m/s. The Marangoni effect drives this velocity from 10 to 15 times higher depending on the operating parameters. Prediction of the solidification microstructure is based on conditions at the trailing edge of the melt pool. Time tracking of solidification history is incorporated into the model to couple the microstructure prediction model to the thermal-fluid flow model, and to predict the probability of the columnar-to-equiaxed transition. Qualitative agreement is obtained between simulation and experimental result.
Flashover of a vacuum-insulator interface: A statistical model
Directory of Open Access Journals (Sweden)
W. A. Stygar
2004-07-01
Full Text Available We have developed a statistical model for the flashover of a 45° vacuum-insulator interface (such as would be found in an accelerator subject to a pulsed electric field. The model assumes that the initiation of a flashover plasma is a stochastic process, that the characteristic statistical component of the flashover delay time is much greater than the plasma formative time, and that the average rate at which flashovers occur is a power-law function of the instantaneous value of the electric field. Under these conditions, we find that the flashover probability is given by 1-exp(-E_{p}^{β}t_{eff}C/k^{β}, where E_{p} is the peak value in time of the spatially averaged electric field E(t, t_{eff}≡∫[E(t/E_{p}]^{β}dt is the effective pulse width, C is the insulator circumference, k∝exp(λ/d, and β and λ are constants. We define E(t as V(t/d, where V(t is the voltage across the insulator and d is the insulator thickness. Since the model assumes that flashovers occur at random azimuthal locations along the insulator, it does not apply to systems that have a significant defect, i.e., a location contaminated with debris or compromised by an imperfection at which flashovers repeatedly take place, and which prevents a random spatial distribution. The model is consistent with flashover measurements to within 7% for pulse widths between 0.5 ns and 10 μs, and to within a factor of 2 between 0.5 ns and 90 s (a span of over 11 orders of magnitude. For these measurements, E_{p} ranges from 64 to 651 kV/cm, d from 0.50 to 4.32 cm, and C from 4.96 to 95.74 cm. The model is significantly more accurate, and is valid over a wider range of parameters, than the J. C. Martin flashover relation that has been in use since 1971 [J. C. Martin on Pulsed Power, edited by T. H. Martin, A. H. Guenther, and M. Kristiansen (Plenum, New York, 1996]. We have generalized the statistical model to estimate the total-flashover probability of an
Stabilization Control of an Autonomous Bicycle: Modeled as an Acrobot with Angular Limitation
Nilsen, Jørgen Herje
2014-01-01
With an inverted pendulum mounted on the bicycle frame, the system is corresponding to a bicyclist who applies balancing torque from the hip. This thesis present a mathematical system model of the autonomous bicycle, modeled as an inverted double pendulum with actuation at the joint connecting the two system links, better known as an Acrobot. The Acrobot is a well-known underactuated robot manipulator, which implies that only the mounted inverted pendulum can obtain instantaneous acceleration...
Ultrasonic-assisted manufacturing processes: Variational model and numerical simulations
Siddiq, Amir
2012-04-01
We present a computational study of ultrasonic assisted manufacturing processes including sheet metal forming, upsetting, and wire drawing. A fully variational porous plasticity model is modified to include ultrasonic softening effects and then utilized to account for instantaneous softening when ultrasonic energy is applied during deformation. Material model parameters are identified via inverse modeling, i.e. by using experimental data. The versatility and predictive ability of the model are demonstrated and the effect of ultrasonic intensity on the manufacturing process at hand is investigated and compared qualitatively with experimental results reported in the literature. © 2011 Elsevier B.V. All rights reserved.
Modeling of Static Characteristics of Switched Reluctance Motor
Directory of Open Access Journals (Sweden)
Ali Asghar Memon
2013-01-01
Full Text Available To investigate the running characteristics of a switched reluctance motor, the static characteristics and related input data tables are required. The static characteristics comprise of flux linkage, co-energy and static torque characteristics. The co-energy and static torque are calculated once data of magnetization characteristics is available. The data of co-energy is required for the calculation of static torque characteristics. The simulation model includes the data of static characteristics for prediction of the instantaneous and steady state performance of the motor. In this research a computer based procedure of experiments is carried out for measurement of the magnetization characteristics. For every set of measurements, the removal of eddy current is carefully addressed. The experiments are carried out on an existing 8/6 pole rotary switched reluctance motor. Additionally, the instantaneous phase current, instantaneous torque and flux waveforms are produced by using linear, which is by default and spline data interpolation separately. The information obtained from theses simulation results will help in an improved simulation model for predicting the performance of the machine.
Directory of Open Access Journals (Sweden)
R.I. Parovik
2012-06-01
Full Text Available In a model of radioactive decay of radon in the sample (222Rn. The model assumes that the probability of the decay of radon and its half-life depends on the fractal properties of the geological environment. The dependencies of the decay parameters of the fractal dimension of the medium.
Directory of Open Access Journals (Sweden)
Katherine Kay
Full Text Available Mechanism-based pharmacokinetic-pharmacodynamic (PK/PD modelling is the standard computational technique for simulating drug treatment of infectious diseases with the potential to enhance our understanding of drug treatment outcomes, drug deployment strategies, and dosing regimens. Standard methodologies assume only a single drug is used, it acts only in its unconverted form, and that oral drugs are instantaneously absorbed across the gut wall to their site of action. For drugs with short half-lives, this absorption period accounts for a significant period of their time in the body. Treatment of infectious diseases often uses combination therapies, so we refined and substantially extended the PK/PD methodologies to incorporate (i time lags and drug concentration profiles resulting from absorption across the gut wall and, if required, conversion to another active form; (ii multiple drugs within a treatment combination; (iii differing modes of action of drugs in the combination: additive, synergistic, antagonistic; (iv drugs converted to an active metabolite with a similar mode of action. This methodology was applied to a case study of two first-line malaria treatments based on artemisinin combination therapies (ACTs, artemether-lumefantrine and artesunate-mefloquine where the likelihood of increased artemisinin tolerance/resistance has led to speculation on their continued long-term effectiveness. We note previous estimates of artemisinin kill rate were underestimated by a factor of seven, both the unconverted and converted form of the artemisinins kill parasites and the extended PK/PD methodology produced results consistent with field observations. The simulations predict that a potentially rapid decline in ACT effectiveness is likely to occur as artemisinin resistance spreads, emphasising the importance of containing the spread of artemisinin resistance before it results in widespread drug failure. We found that PK/PD data is generally very
Numerical model of crustal accretion and cooling rates of fast-spreading mid-ocean ridges
Directory of Open Access Journals (Sweden)
P. Machetel
2013-10-01
Full Text Available We designed a thermo-mechanical numerical model for fast-spreading mid-ocean ridge with variable viscosity, hydrothermal cooling, latent heat release, sheeted dyke layer, and variable melt intrusion possibilities. The model allows for modulating several accretion possibilities such as the "gabbro glacier" (G, the "sheeted sills" (S or the "mixed shallow and MTZ lenses" (M. These three crustal accretion modes have been explored assuming viscosity contrasts of 2 to 3 orders of magnitude between strong and weak phases and various hydrothermal cooling conditions depending on the cracking temperatures value. Mass conservation (stream-function, momentum (vorticity and temperature equations are solved in 2-D cartesian geometry using 2-D, alternate direction, implicit and semi-implicit finite-difference scheme. In a first step, an Eulerian approach is used solving iteratively the motion and temperature equations until reaching steady states. With this procedure, the temperature patterns and motions that are obtained for the various crustal intrusion modes and hydrothermal cooling hypotheses display significant differences near the mid-ocean ridge axis. In a second step, a Lagrangian approach is used, recording the thermal histories and cooling rates of tracers travelling from the ridge axis to their final emplacements in the crust far from the mid-ocean ridge axis. The results show that the tracer's thermal histories are depending on the temperature patterns and the crustal accretion modes near the mid-ocean ridge axis. The instantaneous cooling rates obtained from these thermal histories betray these discrepancies and might therefore be used to characterize the crustal accretion mode at the ridge axis. These deciphering effects are even more pronounced if we consider the average cooling rates occurring over a prescribed temperature range. Two situations were tested at 1275–1125 °C and 1050–850 °C. The first temperature range covers mainly the
Directory of Open Access Journals (Sweden)
Eduardo G. Souza
2006-06-01
Full Text Available Reflectance measurements of crop plants and canopies show promise for guiding within-season, variable-rate nitrogen (N application. Most research results have been obtained around solar noon with clear skies. However, for practical application, the system must work under cloudy skies or away from solar noon. The objective of this work was to assess the effect of cloud conditions on reflectance measurements of a corn canopy. The approach was to estimate an instantaneous sky clearness index (ICI which could be used to correct field radiometer data for variations in cloud cover, such that the same reflectance reading would be obtained (and the same N recommendation made for the same plants regardless of cloud conditions. Readings were taken from morning until night over 11 days with a range of sky conditions (sunny, overcast, partly cloudy. Data from clear days were used to estimate the theoretical expected spectral global radiation incident on a horizontal surface. The ICI was calculated as the ratio between the actual spectral global radiation and the corresponding theoretical global radiation. Analysis of the ICI for each band showed that the influence of cloudiness was different for each band. Thus, the cloud effect could not be compensated by the use of a band ratio or vegetation index.Medidas da reflectância das folhas das plantas mostram-se promissoras para a aplicação de nitrogênio a taxa variável; entretanto, a maioria dos resultados de pesquisa foi obtida ao redor do meio-dia solar e com céu aberto, porém para aplicações práticas um sistema tem que trabalhar debaixo de céu nublado e fora do meio-dia solar. O objetivo deste trabalho foi avaliar o efeito de condições de nuvem em medidas de reflectância de milho. A abordagem foi calcular um índice instantâneo de clareza do céu (ICI que pode ser usado para corrigir dados de radiômetros de campo para variações em cobertura de nuvem, tal que essas reflectâncias seriam
Directory of Open Access Journals (Sweden)
J. A. Valladares
2010-09-01
Full Text Available
The service, one of the more important actions in volleyball has been conditioned by the experienced evolution by this sport over the past decades, what has brought important changes in the execution of the technique of the service just as in the tactical systems used by the teams. According to an observational model, a methodological proposal developed in five phases has ensued for analysis and assessment of the level of risk that they assume them players of volleyball in juvenile category in the service regarding the obtained efficacy. In that one methodology has been identified and established the variables that affect it, stops at a later time quantifying and examining the level of risk in terms of the kind of service and of the trajectory described all by himself. The obtained data (2.237 cases were examined statistically to come to an end that this category does not appraise a command and control itself enough as if to evidence a tactical obvious intentionality that players would assume a voluntary risk level and once the situation was adapted of the match.
KEY WORDS: volleyball, service, risk level, efficacy.
La evolución experimentada por el voleibol a lo largo de las últimas décadas ha condicionado en gran medida una de las acciones de juego más importantes, el servicio, lo que ha traído consigo notables cambios en la ejecución técnica del saque, así como en los sistemas tácticos empleados por los equipos. Atendiendo a un modelo observacional, se ha seguido una propuesta metodológica desarrollada en cinco fases para el análisis y valoración del nivel de riesgo que asumen las jugadoras de voleibol en categoría juvenil en el servicio con respecto a la eficacia obtenida. En dicha metodología se han identificado y establecido las variables que lo afectan, para posteriormente cuantificar y
24 CFR 203.512 - Free assumability; exceptions.
2010-04-01
... AUTHORITIES SINGLE FAMILY MORTGAGE INSURANCE Servicing Responsibilities General Requirements § 203.512 Free..., agree to or enforce legal restrictions on conveyance, as defined in § 203.41(a)(3) of this part, or... descent. (c) Investors and secondary residences. The mortgagee shall not approve the sale of other...
THE MODIFICATION OF THE INDIVIDUAL EMPLOYMENT CONTRACT ASSUMING UNPREDICTABILITY
Directory of Open Access Journals (Sweden)
Ana Vidat
2012-11-01
Full Text Available Adapting a gainful occupation to technological or economical development may require the amendment of individual labor contract under which the activity is performed, taking into account the intrinsic dynamics of employment. If the parties, by agreement, determine the content of the individual labor contract, all in agreement, may agree at any time to amend it according to art. 41 para. 1 of the Labour Code. And trough the provisions of civil law – common law for the employment law – are established legal the review of the effects of the legal actdue because of the breakage contractual balance due to change in the circumstances envisaged by the parties in the moment of conclusion of the legal act (the so-called theory of unpredictability, rebus sic stantibus – exception to the principle "pacta sunt servanda". Recourse to the legal document review because its effects are other than the parties agreed to establish and be binding in the moment of conclusion of that agreement. In the present paper we will refer to administrative contracts, given the subject of this paper – namely that the common law for individual employment contract is the civil law rules applicable to civil contracts. So in this paper does not refer to former commercial contracts, since the new Civil Code was achieved unification of private law matter – giving up the commercial contracts.
Assume the Mantle: Strategic Leadership in the Confederate West
2011-03-01
of the 2d Cavalry Regiment (1855); selected by President Buchanan to lead the Utah Expedition against the Mormons (1857); and Commander of the US...compliment with compound interest. His hatred of Jeff Davis amounts to a religion . With him it colors all things.”50 And with him, the last of the
Family size: implicit policies and assumed psychological outcomes.
Thompson, V D
1977-01-01
Negative stereotypes are attached to childless or 1-child couples and to only children. People choosing to have fewer than the socially predicted 2-child norm are responding to rational, individual norms instead of exterior normative pressures. Research has shown that only or widely spaced children benefit from adult contact during development. There is an inverse relationship between intelligence and family size. Only and 1st-born personality characteristics tend to contradict the negative stereotypes. Different reasons why couples choose to have children do not differentially determine the health of the children or the marriage.
Accurate or Assumed: Visual Learning in Children with ASD
Trembath, David; Vivanti, Giacomo; Iacono, Teresa; Dissanayake, Cheryl
2015-01-01
Children with autism spectrum disorder (ASD) are often described as visual learners. We tested this assumption in an experiment in which 25 children with ASD, 19 children with global developmental delay (GDD), and 17 typically developing (TD) children were presented a series of videos via an eye tracker in which an actor instructed them to…
May We Continue Informing or May We Assume the Change?
Directory of Open Access Journals (Sweden)
María Orfa Rojas
2006-10-01
Full Text Available Traditional educative systems, had convertstudents in passive recipient, who are keepingRecibido: Marzo 3 de 2006.Aceptado: Abril 17 de 2006.* Ph.D, Profesora titular.** Ph.D, Profesora principal.+ M.D., MSc, Profesora principal, Unidad de Bioquímica,Instituto de Ciencias Básicas, Facultad de Medicina,Colegio Mayor Universidad del Rosario.Autor correspondiente: María Orfa Rojas, Unidad deBioquímica, Facultad de Medicina de la Universidaddel Rosario, mariaorfarojas@yahoo.comArtículo de reflexióninformation without any possibility to processand apply it for the solution of daily problems.General discussion between educative researchers,had been establish the necessity to changethe educative strategies that have been supportingthose situations, looking for an integraleducation of the individual in terms of the capacityto argue, to create, to innovate, to developby him self with independence.Governments, institutions and the politicsrequirements, that handle the globalization andthe human development based in the knowledgeeconomy, demand changes in the pedagogicalsystem strategies in spite of the barriers fromthe traditional educative system. Responding tothese necessity, the Biochemistry Departmentbelong to the Basic Sciences Institute from theMedicine Faculty in the University of Rosario,is applying a different pedagogical strategy.
From Relational Interfaces to Assume-Guarantee Contracts
2014-03-18
5] A. Benveniste, B. Caillaud, A. Ferrari, L. Mangeruca, R. Passerone , and C. Sofronis, “Multiple viewpoint contract-based specification and design...in FMCO, 2008. [6] A. Benveniste, B. Caillaud, D. Nickovic, R. Passerone , J.-B. Raclet, P. Reinkemeier et al., “Contracts for System Design,” INRIA...contracts in component-based design,” in FASE, 2012, pp. 43–58. [8] S. Quinton, S. Graf, and R. Passerone , “Contract-based reasoning for component systems
As Patient Navigation Expands and Evolves, Nurses Assume Many Roles
It can be difficult to access care in our labyrinthine health care system. Oncology nurses are joining the ranks of patient navigators—a diverse group of people who help patients at all stages of cancer care, from screening and diagnosis to treatment and survivorship.
Don’t Assume Deaf Students are Visual Learners
Marschark, Marc; Paivio, Allan; Spencer, Linda J.; Durkin, Andreana; Borgna, Georgianna; Convertino, Carol; Machmer, Elizabeth
2016-01-01
In the education of deaf learners, from primary school to postsecondary settings, it frequently is suggested that deaf students are visual learners. That assumption appears to be based on the visual nature of signed languages—used by some but not all deaf individuals—and the fact that with greater hearing losses, deaf students will rely relatively more on vision than audition. However, the questions of whether individuals with hearing loss are more likely to be visual learners than verbal learners or more likely than hearing peers to be visual learners have not been empirically explored. Several recent studies, in fact, have indicated that hearing learners typically perform as well or better than deaf learners on a variety of visual-spatial tasks. The present study used two standardized instruments to examine learning styles among college deaf students who primarily rely on sign language or spoken language and their hearing peers. The visual-verbal dimension was of particular interest. Consistent with recent indirect findings, results indicated that deaf students are no more likely than hearing students to be visual learners and are no stronger in their visual skills and habits than their verbal skills and habits, nor are deaf students’ visual orientations associated with sign language skills. The results clearly have specific implications for the educating of deaf learners. PMID:28344430
24 CFR 203.41 - Free assumability; exceptions.
2010-04-01
... otherwise provided in the HOME Investment Partnerships (HOME) and the Homeownership and Opportunity for... limitations applicable in the jurisdiction. (3) Except as otherwise required by the HOME and HOPE programs... that the holder of the right of entry for condition broken also executes the mortgage, and that the...
The assumed relation between occupation and inequality in health
DEFF Research Database (Denmark)
Madsen, Jacob; Kanstrup, Anne Marie; Josephsson, Staffan
2016-01-01
in health, high-risk areas of health, and engagement in health for low-income adult citizens have been described and conceptualized in contemporary occupational science and therapy literature. Material and methods: A structured literature review of 37 publications in occupational science and therapy...... on assumptions regarding the relation between occupation and inequality in health, and statements on the need to explore this relation. Conclusion: Basic theory and reasoning, as well as empirical studies, on inequality in health are missing in occupational science and therapy. Based on the findings...