WorldWideScience

Sample records for model results compare

  1. Computations for the 1:5 model of the THTR pressure vessel compared with experimental results

    International Nuclear Information System (INIS)

    Stangenberg, F.

    1972-01-01

    In this report experimental results measured at the 1:5-model of the prestressed concrete pressure vessel of the THTR-nuclear power station Schmehausen in 1971, are compared with the results of axis-symmetrical computations. Linear-elastic computations were performed as well as approximate computations for overload pressures taking into consideration the influences of the load history (prestressing, temperature, creep) and the effects of the steel components. (orig.) [de

  2. Comparative Results on 3D Navigation of Quadrotor using two Nonlinear Model based Controllers

    Science.gov (United States)

    Bouzid, Y.; Siguerdidjane, H.; Bestaoui, Y.

    2017-01-01

    Recently the quadrotors are being increasingly employed in both military and civilian areas where a broad range of nonlinear flight control techniques are successfully implemented. With this advancement, it has become necessary to investigate the efficiency of these flight controllers by studying theirs features and compare their performance. In this paper, the control of Unmanned Aerial Vehicle (UAV) quadrotor, using two different approaches, is presented. The first controller is Nonlinear PID (NLPID) whilst the second one is Nonlinear Internal Model Control (NLIMC) that are used for the stabilization as well as for the 3D trajectory tracking. The numerical simulations have shown satisfactory results using nominal system model or disturbed model for both of them. The obtained results are analyzed with respect to several criteria for the sake of comparison.

  3. Comparability of results from pair and classical model formulations for different sexually transmitted infections.

    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.

  4. Recent results on the spatiotemporal modelling and comparative analysis of Black Death and bubonic plague epidemics

    Science.gov (United States)

    Christakos, G.; Olea, R.A.; Yu, H.-L.

    2007-01-01

    Background: This work demonstrates the importance of spatiotemporal stochastic modelling in constructing maps of major epidemics from fragmentary information, assessing population impacts, searching for possible etiologies, and performing comparative analysis of epidemics. Methods: Based on the theory previously published by the authors and incorporating new knowledge bases, informative maps of the composite space-time distributions were generated for important characteristics of two major epidemics: Black Death (14th century Western Europe) and bubonic plague (19th-20th century Indian subcontinent). Results: The comparative spatiotemporal analysis of the epidemics led to a number of interesting findings: (1) the two epidemics exhibited certain differences in their spatiotemporal characteristics (correlation structures, trends, occurrence patterns and propagation speeds) that need to be explained by means of an interdisciplinary effort; (2) geographical epidemic indicators confirmed in a rigorous quantitative manner the partial findings of isolated reports and time series that Black Death mortality was two orders of magnitude higher than that of bubonic plague; (3) modern bubonic plague is a rural disease hitting harder the small villages in the countryside whereas Black Death was a devastating epidemic that indiscriminately attacked large urban centres and the countryside, and while the epidemic in India lasted uninterruptedly for five decades, in Western Europe it lasted three and a half years; (4) the epidemics had reverse areal extension features in response to annual seasonal variations. Temperature increase at the end of winter led to an expansion of infected geographical area for Black Death and a reduction for bubonic plague, reaching a climax at the end of spring when the infected area in Western Europe was always larger than in India. Conversely, without exception, the infected area during winter was larger for the Indian bubonic plague; (5) during the

  5. Interannual sedimentary effluxes of alkalinity in the southern North Sea: Model results compared with summer observations.

    Science.gov (United States)

    Paetsch, Johannes; Kuehn, Wilfried; Six, Katharina

    2016-04-01

    Alkalinity generation in the sediment of the southern North Sea is the focus of several recent studies. One motivation for these efforts is the potentially enhanced buffering capacity of anthropogenic CO2 invasion into the corresponding pelagic system. An adaptation of a global multilayer sediment model (Heinze et al., 1999) in combination with a pelagic ecosystem model for shelf sea dynamics was used to study the benthic reactions on very different annual cycles (2001 - 2009) including the River Elbe summer flooding in 2002. The focus of this study is the efflux of alkalinity, their different contributors (aerobic respiration, denitrification, net sulfate reduction, calcite dissolution, nitrification) and their seasonal and interannual cycles. Similar to the observations covering the southern North Sea (Brenner et al., 2015) the model results show large horizontal gradients from the near-shore high productive areas with benthic remineralization up to Rmin = 10.6 mol C m-2 yr-1 and TA generation RTA = 2 mol C m-2 yr-1 to off-shore moderate productive areas with mean Rmin = 2.5 mol C m-2 yr-1 and mean TA generation RTA = 0.4 mol C m-2 yr-1. Beside calcite dissolution, aerobic respiration (producing ammonium) and denitrification are the largest contributors to alkalinity generation. Nitrification is reducing alkalinity in the sediment. Due to low regenerated primary production in summer, the year 2001 exhibits the lowest input of particulate organic matter into the sediment (POCexp=2.3 mol C m-2 yr-1), while the year 2003 exhibits the highest export production (POCexp=2.6 mol C m-2 yr-1). The biogeochemical reactions and the effluxes from the sediment follow these pelagic amplitudes with a time lag of about one year with damped amplitudes. References Brenner, H., Braeckman, U., Le Guitton, M., Meysman, F.J.R., 2015. The impact of sedimentary alkalinity release on the water column CO2 system in the North Sea. Biogeosiences Discussion, 12(15): 12395-12453. Heinze, C

  6. Recent results on the spatiotemporal modelling and comparative analysis of Black Death and bubonic plague epidemics.

    Science.gov (United States)

    Christakos, G; Olea, R A; Yu, H-L

    2007-09-01

    This work demonstrates the importance of spatiotemporal stochastic modelling in constructing maps of major epidemics from fragmentary information, assessing population impacts, searching for possible etiologies, and performing comparative analysis of epidemics. Based on the theory previously published by the authors and incorporating new knowledge bases, informative maps of the composite space-time distributions were generated for important characteristics of two major epidemics: Black Death (14th century Western Europe) and bubonic plague (19th-20th century Indian subcontinent). The comparative spatiotemporal analysis of the epidemics led to a number of interesting findings: (1) the two epidemics exhibited certain differences in their spatiotemporal characteristics (correlation structures, trends, occurrence patterns and propagation speeds) that need to be explained by means of an interdisciplinary effort; (2) geographical epidemic indicators confirmed in a rigorous quantitative manner the partial findings of isolated reports and time series that Black Death mortality was two orders of magnitude higher than that of bubonic plague; (3) modern bubonic plague is a rural disease hitting harder the small villages in the countryside whereas Black Death was a devastating epidemic that indiscriminately attacked large urban centres and the countryside, and while the epidemic in India lasted uninterruptedly for five decades, in Western Europe it lasted three and a half years; (4) the epidemics had reverse areal extension features in response to annual seasonal variations. Temperature increase at the end of winter led to an expansion of infected geographical area for Black Death and a reduction for bubonic plague, reaching a climax at the end of spring when the infected area in Western Europe was always larger than in India. Conversely, without exception, the infected area during winter was larger for the Indian bubonic plague; (5) during the Indian epidemic, the disease

  7. Comparative Climates of the Trappist-1 Planetary System: Results from a Simple Climate-vegetation Model

    Science.gov (United States)

    Alberti, Tommaso; Carbone, Vincenzo; Lepreti, Fabio; Vecchio, Antonio

    2017-07-01

    The recent discovery of the planetary system hosted by the ultracool dwarf star TRAPPIST-1 could open new paths for investigations of the planetary climates of Earth-sized exoplanets, their atmospheres, and their possible habitability. In this paper, we use a simple climate-vegetation energy-balance model to study the climate of the seven TRAPPIST-1 planets and the climate dependence on various factors: the global albedo, the fraction of vegetation that could cover their surfaces, and the different greenhouse conditions. The model allows us to investigate whether liquid water could be maintained on the planetary surfaces (I.e., by defining a “surface water zone (SWZ)”) in different planetary conditions, with or without the presence of a greenhouse effect. It is shown that planet TRAPPIST-1d seems to be the most stable from an Earth-like perspective, since it resides in the SWZ for a wide range of reasonable values of the model parameters. Moreover, according to the model, outer planets (f, g, and h) cannot host liquid water on their surfaces, even with Earth-like conditions, entering a snowball state. Although very simple, the model allows us to extract the main features of the TRAPPIST-1 planetary climates.

  8. Comparative Climates of the Trappist-1 Planetary System: Results from a Simple Climate-vegetation Model

    Energy Technology Data Exchange (ETDEWEB)

    Alberti, Tommaso; Carbone, Vincenzo; Lepreti, Fabio [Dipartimento di Fisica, Università della Calabria, Ponte P. Bucci, Cubo 31C, I-87036, Rende (CS) (Italy); Vecchio, Antonio, E-mail: tommaso.alberti@unical.it, E-mail: tommasoalberti89@gmail.com [LESIA—Observatoire de Paris, PSL Research University, 5 place Jules Janssen, F-92190, Meudon (France)

    2017-07-20

    The recent discovery of the planetary system hosted by the ultracool dwarf star TRAPPIST-1 could open new paths for investigations of the planetary climates of Earth-sized exoplanets, their atmospheres, and their possible habitability. In this paper, we use a simple climate-vegetation energy-balance model to study the climate of the seven TRAPPIST-1 planets and the climate dependence on various factors: the global albedo, the fraction of vegetation that could cover their surfaces, and the different greenhouse conditions. The model allows us to investigate whether liquid water could be maintained on the planetary surfaces (i.e., by defining a “surface water zone (SWZ)”) in different planetary conditions, with or without the presence of a greenhouse effect. It is shown that planet TRAPPIST-1d seems to be the most stable from an Earth-like perspective, since it resides in the SWZ for a wide range of reasonable values of the model parameters. Moreover, according to the model, outer planets (f, g, and h) cannot host liquid water on their surfaces, even with Earth-like conditions, entering a snowball state. Although very simple, the model allows us to extract the main features of the TRAPPIST-1 planetary climates.

  9. Model-theoretic Optimization Approach to Triathlon Performance Under Comparative Static Conditions – Results Based on The Olympic Games 2012

    Directory of Open Access Journals (Sweden)

    Michael Fröhlich

    2013-10-01

    Full Text Available In Olympic-distance triathlon, time minimization is the goal in all three disciplines and the two transitions. Running is the key to winning, whereas swimming and cycling performance are less significantly associated with overall competition time. A comparative static simulation calculation based on the individual times of each discipline was done. Furthermore, the share of the discipline in the total time proved that increasing the scope of running training results in an additional performance development. Looking at the current development in triathlon and taking the Olympic Games in London 2012 as an initial basis for model-theoretic simulations of performance development, the first fact that attracts attention is that running becomes more and more the crucial variable in terms of winning a triathlon. Run times below 29:00 minutes in Olympic-distance triathlon will be decisive for winning. Currently, cycle training time is definitely overrepresented. The share of swimming is considered optimal.

  10. Comparing results from multiple imputation and dynamic marginal structural models for estimating when to start antiretroviral therapy.

    Science.gov (United States)

    Shepherd, Bryan E; Liu, Qi; Mercaldo, Nathaniel; Jenkins, Cathy A; Lau, Bryan; Cole, Stephen R; Saag, Michael S; Sterling, Timothy R

    2016-10-30

    Optimal timing of initiating antiretroviral therapy has been a controversial topic in HIV research. Two highly publicized studies applied different analytical approaches, a dynamic marginal structural model and a multiple imputation method, to different observational databases and came up with different conclusions. Discrepancies between the two studies' results could be due to differences between patient populations, fundamental differences between statistical methods, or differences between implementation details. For example, the two studies adjusted for different covariates, compared different thresholds, and had different criteria for qualifying measurements. If both analytical approaches were applied to the same cohort holding technical details constant, would their results be similar? In this study, we applied both statistical approaches using observational data from 12,708 HIV-infected persons throughout the USA. We held technical details constant between the two methods and then repeated analyses varying technical details to understand what impact they had on findings. We also present results applying both approaches to simulated data. Results were similar, although not identical, when technical details were held constant between the two statistical methods. Confidence intervals for the dynamic marginal structural model tended to be wider than those from the imputation approach, although this may have been due in part to additional external data used in the imputation analysis. We also consider differences in the estimands, required data, and assumptions of the two statistical methods. Our study provides insights into assessing optimal dynamic treatment regimes in the context of starting antiretroviral therapy and in more general settings. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Global stratospheric hydrogen peroxide distribution from MIPAS-Envisat full resolution spectra compared to KASIMA model results

    Directory of Open Access Journals (Sweden)

    S. Versick

    2012-06-01

    Full Text Available MIPAS-ENVISAT full resolution spectra were analyzed to obtain a global distribution of hydrogen peroxide (H2O2 in the stratosphere. H2O2 acts as reservoir gas for the HOx family (= H+OH+HO2 and thus, observations of H2O2 provide a better understanding of the HOx chemistry in the atmosphere. A retrieval approach based on constrained least squares fitting was developed and applied to small dedicated spectral analysis windows with maximum H2O2 information and minimum contribution of interfering gases. Due to a low signal to noise ratio in the measured spectra single profiles cannot be used for scientific interpretation and about 100 profiles have to be averaged temporally or spatially. Our retrievals of H2O2 from MIPAS measurements provide meaningful results between approximately 20 and 60 km. A possible impact by the high uncertainty of the reaction rate constant for HO2 + HO2→H2O2 + O2 in our 3D-CTM KASIMA is discussed. We find best agreement between model and observations for applying rate constants according to Christensen et al. (2002 however, a mismatch in vertical profile shape remains. The observations were compared to the model results of KASIMA focusing on low to mid latitudes. Good agreement in spatial distribution and in temporal evolution was found. Highest vmr of H2O2 in the stratosphere were observed and modeled in low latitudes shortly after equinox at about 30 km. The modelled diurnal cycle with lowest vmr shortly after sunrise and highest vmr in the afternoon is confirmed by the MIPAS observations.

  12. MODELING OF THE PROCESS OF FORMATION OF INDIVIDUAL MARKETING DEMAND: A COMPARATIVE ANALYSIS AND GENERALIZATION OF THE PRECEDING CORRESPONDING RESULTS

    Directory of Open Access Journals (Sweden)

    Anatoly V. Korotkov

    2015-01-01

    Full Text Available The article focuses on the modeling of series-STI formation of individual market demand. The analysis, and then sum-of three well-known inmarketing models, which exhaust the currentlyknown approaches is revised. The article shows that all three models have a signifi cant difference in the number of stages and terminology. The obtained results are the basis for the developmentof the author’s model of gradual development of demand - «need - desire - requirement -demand» or abbreviated as «model NDRD» and can be considered as a contribution to the methodology of study a demand.

  13. Palaeotemperature reconstructions of the European permafrost zone during Oxygen Isotope Stage 3 compared with climate model results.

    NARCIS (Netherlands)

    van Huissteden, J.; Vandenberghe, J.; Pollard, D.

    2003-01-01

    A palaeotemperature reconstruction based on periglacial phenomena in Europe north of approximately 51 °N, is compared with high-resolution regional climate model simulations of the marine oxygen isotope Stage 3 (Stage 3) palaeoclimate. The experiments represent Stage 3 warm (interstadial), Stage 3

  14. Preliminary comparative assessment and elements of equivalence of air pollution measurement results of portable monitoring stations with using stochastic models

    Science.gov (United States)

    Owczarek, Tomasz; Rogulski, Mariusz; Badyda, Artur

    2018-01-01

    This article is an attempt to assess the suitability of new non-reference mobile measuring devices for the analysis of PM10 concentrations. The aim is to compare the concentration daily values measured by these devices with the concentrations obtained by the reference device. It also examines the possibility of building models that correct these values to equivalent reference values. The analysis allows to conclude that the properties of the obtained measurements indicate a good chance of constructing an effective model of correcting the concentration values. Comparison of frequency, time variation and correlation of concentrations indicates the ability to demonstrate the equivalence of mobile devices with the reference method.

  15. Vehicle Speed Determination in Case of Road Accident by Software Method and Comparing of Results with the Mathematical Model

    Directory of Open Access Journals (Sweden)

    Hoxha Gezim

    2017-11-01

    Full Text Available The paper addresses the problem to vehicle speed calculation at road accidents. To determine the speed are used the PC Crash software and Virtual Crash. With both methods are analysed concrete cases of road accidents. Calculation methods and comparing results are present for analyse. These methods consider several factors such are: the front part of the vehicle, the technical feature of the vehicle, car angle, remote relocation after the crash, road conditions etc. Expected results with PC Crash software and Virtual Crash are shown in tabular graphics and compared in mathematical methods.

  16. Vehicle Speed Determination in Case of Road Accident by Software Method and Comparing of Results with the Mathematical Model

    OpenAIRE

    Hoxha Gezim; Shala Ahmet; Likaj Rame

    2017-01-01

    The paper addresses the problem to vehicle speed calculation at road accidents. To determine the speed are used the PC Crash software and Virtual Crash. With both methods are analysed concrete cases of road accidents. Calculation methods and comparing results are present for analyse. These methods consider several factors such are: the front part of the vehicle, the technical feature of the vehicle, car angle, remote relocation after the crash, road conditions etc. Expected results with PC Cr...

  17. Comparing Active Vision Models

    NARCIS (Netherlands)

    Croon, G.C.H.E. de; Sprinkhuizen-Kuyper, I.G.; Postma, E.O.

    2009-01-01

    Active vision models can simplify visual tasks, provided that they can select sensible actions given incoming sensory inputs. Many active vision models have been proposed, but a comparative evaluation of these models is lacking. We present a comparison of active vision models from two different

  18. Comparing active vision models

    NARCIS (Netherlands)

    Croon, G.C.H.E. de; Sprinkhuizen-Kuyper, I.G.; Postma, E.O.

    2009-01-01

    Active vision models can simplify visual tasks, provided that they can select sensible actions given incoming sensory inputs. Many active vision models have been proposed, but a comparative evaluation of these models is lacking. We present a comparison of active vision models from two different

  19. Preliminary comparative assessment of PM10 hourly measurement results from new monitoring stations type using stochastic and exploratory methodology and models

    Science.gov (United States)

    Czechowski, Piotr Oskar; Owczarek, Tomasz; Badyda, Artur; Majewski, Grzegorz; Rogulski, Mariusz; Ogrodnik, Paweł

    2018-01-01

    The paper presents selected preliminary stage key issues proposed extended equivalence measurement results assessment for new portable devices - the comparability PM10 concentration results hourly series with reference station measurement results with statistical methods. In article presented new portable meters technical aspects. The emphasis was placed on the comparability the results using the stochastic and exploratory methods methodology concept. The concept is based on notice that results series simple comparability in the time domain is insufficient. The comparison of regularity should be done in three complementary fields of statistical modeling: time, frequency and space. The proposal is based on model's results of five annual series measurement results new mobile devices and WIOS (Provincial Environmental Protection Inspectorate) reference station located in Nowy Sacz city. The obtained results indicate both the comparison methodology completeness and the high correspondence obtained new measurements results devices with reference.

  20. Underwater floating robot-fish: a comparative analysis of the results of mathematical modelling and full-scale tests of the prototype

    Directory of Open Access Journals (Sweden)

    Jatsun Sergey

    2017-01-01

    Full Text Available The article presents a comparative analysis of the results of computer mathematical modelling of the motion of the underwater robot-fish implemented by using the MATLAB / Simulink package and fullscale tests of an experimental model developed in the laboratory of mechatronics and robotics of the SouthWest State University.

  1. Comparing root architectural models

    Science.gov (United States)

    Schnepf, Andrea; Javaux, Mathieu; Vanderborght, Jan

    2017-04-01

    Plant roots play an important role in several soil processes (Gregory 2006). Root architecture development determines the sites in soil where roots provide input of carbon and energy and take up water and solutes. However, root architecture is difficult to determine experimentally when grown in opaque soil. Thus, root architectural models have been widely used and been further developed into functional-structural models that are able to simulate the fate of water and solutes in the soil-root system (Dunbabin et al. 2013). Still, a systematic comparison of the different root architectural models is missing. In this work, we focus on discrete root architecture models where roots are described by connected line segments. These models differ (a) in their model concepts, such as the description of distance between branches based on a prescribed distance (inter-nodal distance) or based on a prescribed time interval. Furthermore, these models differ (b) in the implementation of the same concept, such as the time step size, the spatial discretization along the root axes or the way stochasticity of parameters such as root growth direction, growth rate, branch spacing, branching angles are treated. Based on the example of two such different root models, the root growth module of R-SWMS and RootBox, we show the impact of these differences on simulated root architecture and aggregated information computed from this detailed simulation results, taking into account the stochastic nature of those models. References Dunbabin, V.M., Postma, J.A., Schnepf, A., Pagès, L., Javaux, M., Wu, L., Leitner, D., Chen, Y.L., Rengel, Z., Diggle, A.J. Modelling root-soil interactions using three-dimensional models of root growth, architecture and function (2013) Plant and Soil, 372 (1-2), pp. 93 - 124. Gregory (2006) Roots, rhizosphere and soil: the route to a better understanding of soil science? European Journal of Soil Science 57: 2-12.

  2. Atmospheric Deposition Modeling Results

    Data.gov (United States)

    U.S. Environmental Protection Agency — This asset provides data on model results for dry and total deposition of sulfur, nitrogen and base cation species. Components include deposition velocities, dry...

  3. Experiments on the Model Testing of the 2nd Phase of Die Casting Process Compared with the Results of Numerical Simulation

    Directory of Open Access Journals (Sweden)

    Dańko R.

    2015-12-01

    Full Text Available Experiments of filling the model moulds cavity of various inner shapes inserted in rectangular cavity of the casting die (dimensions: 280 mm (height × 190 mm (width × 10 mm (depth by applying model liquids of various density and viscosity are presented in the paper. Influence of die venting as well as inlet system area and inlet velocity on the volumetric rate of filling of the model liquid - achieved by means of filming the process in the system of a cold-chamber casting die was tested. Experiments compared with the results of simulation performed by means of the calculation module Novacast (Novaflow&Solid for the selected various casting conditions - are also presented in the paper.

  4. Comparing reconstructed past variations and future projections of the Baltic Sea ecosystem—first results from multi-model ensemble simulations

    DEFF Research Database (Denmark)

    Meier, H E Markus; Andersson, Helén C; Arheimer, Berit

    2012-01-01

    Multi-model ensemble simulations for the marine biogeochemistry and food web of the Baltic Sea were performed for the period 1850–2098, and projected changes in the future climate were compared with the past climate environment. For the past period 1850–2006, atmospheric, hydrological and nutrien...... only little attention to adaptation and mitigation strategies, more information is needed to raise public awareness of the possible impacts of climate change on marine ecosystems....... in a biomass decline during the latter part of this century, even when combined with lower fishing pressure. Despite considerable shortcomings of state-of-the-art models, this study suggests that the future Baltic Sea ecosystem may unprecedentedly change compared to the past 150 yr. As stakeholders today pay...

  5. Comparing dynamic recording of infiltration by X-Ray tomography to the results of a dual porosity model for structured soils

    Science.gov (United States)

    Lissy, Anne-Sophie; Sammartino, Stephane; Di Pietro, Liliana; Lecompte, François; Ruy, Stephane

    2017-04-01

    With climate change, preferential flow phenomenon in soil could be predominant in Mediterranean zone. Understanding this phenomenon becomes a fundamental issue for preserving the water resource in quantity (drinking water) and quality (pesticide content). Non-invasive imaging technics, as X-ray tomography, allow studying water infiltration in laboratory with time-lapse imaging to visualize preferential flow path in soil columns (Sammartino et al. 2012). The modeling of water flow with a dual porosity model (matrix and macropores) integrates these fast flow phenomena (Ilhem 2014). These models, however needs more explicit links with the soil structure. The comparison of experimental results of infiltration (dynamics images and mass data) and modeling could improve our comprehension of preferential flow phenomenon and allow a better integration of the functional macroporosity (i.e. which drains water infiltration during a rain event) in such mass transfer models (Sammartino et al. 2015). Soil columns (Ø 12 cm - hauteur 13 cm, clay-loamy & medium sandy loam) have been sampled in the field to preserve their structure (field plowed or not). Several rains have been simulated in the laboratory and the last one was performed in an X-ray medical scanner (Siemens Somatom® 128 slices) at the CIRE platform (INRA, Centre - Val de Loire). Total and functional macro porosities were identified from time lapse tridimensional images. Water dynamics in the porosities was characterized from the identification and analysis of voxels filled by water. With an image resolution of 350μm only water in the largest macropores can be identified. The modeling of these experiments was carried out via the VirtualSoil platform (UMR Emmah, Avignon; www6.inra.fr/vsoil) using a water flow model coupling Darcy-Richards and KDW equations (Di Pietro et al., 2003). The simulated water flux drained by macropores is similar to the experimental hydrograph obtained for rainfalls on soils close to the

  6. Structural modifications in the arterial wall during physiological aging and as a result of diabetes mellitus in a mouse model: are the changes comparable?

    Science.gov (United States)

    Prévost, G; Bulckaen, H; Gaxatte, C; Boulanger, E; Béraud, G; Creusy, C; Puisieux, F; Fontaine, P

    2011-04-01

    Vascular accelerated aging represents the major cause of morbidity and mortality in subjects with diabetes mellitus. In the present study, our aim was to compare premature functional and morphological changes in the arterial wall resulting from streptozotocin (STZ)-induced diabetes mellitus in mice over a short-term period with those that develop during physiological aging. The effect of aminoguanidine (AG) on the prevention of these alterations in the diabetic group was also analyzed. The vascular relaxation response to acetylcholine (ACh) in the mouse was tested in isolated segments of phenylephrine (Phe)-precontracted aorta at 2, 4 and 8 weeks (wk) of STZ-induced diabetes and compare to 12- and 84-wk-old mice. Aortic structural changes were investigated, and receptor for AGE (RAGE) aortic expression was quantified by western blot. Compared to the 12-wk control group (76 ± 5%), significant endothelium-dependant relaxation (EDR) impairment was found in the group of 12-wk-old mice, which underwent a 4-wk diabetes-inducing STZ treatment (12wk-4WD) (52 ± 4%; P aging preventive effect on the structural changes of the arterial wall. Our study compared EDR linked to physiological aging with that observed in the case of STZ-induced diabetes over a short-term period, and demonstrated the beneficial effect of AG. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  7. Comparing PD results with visual inspection

    International Nuclear Information System (INIS)

    Rossi, A.; Stone, G.C.

    2005-01-01

    ENEL is the main generation utility in Italy, with more than 200 hydro units and 120 turbine generators, totaling 39,000 MW of capacity. To help identify the maintenance needs of the stator windings in these units, ENEL has been gradually equipping the generators with partial discharge (PD) sensors that facilitate an on-line measurement of the PD. The paper describes results from several machines that have PD. In all cases, the high PD was confirmed by visual inspections. Although PD usually found the units with severe insulation problems, it was not always possible to determine the causes of the deterioration from the PD pattern. (author)

  8. A USCLIVAR Project to Assess and Compare the Responses of Global Climate Models to Drought-Related SST Forcing Patterns: Overview and Results

    Science.gov (United States)

    Schubert, Siegfried; Wang, Hailan; Koster, Randal; Weaver, Scott; Gutzler, David; Dai, Aiguo; Delworth, Tom; Deser, Clara; Findell, Kristen; Fu, Rong; hide

    2009-01-01

    The USCLI VAR working group on drought recently initiated a series of global climate model simulations forced with idealized SST anomaly patterns, designed to address a number of uncertainties regarding the impact of SST forcing and the role of land-atmosphere feedbacks on regional drought. Specific questions that the runs are designed to address include: What are the mechanisms that maintain drought across the seasonal cycle and from one year to the next? What is the role of the leading patterns of SST variability, and what are the physical mechanisms linking the remote SST forcing to regional drought, including the role of land-atmosphere coupling? The runs were carried out with five different atmospheric general circulation models (AGCM5), and one coupled atmosphere-ocean model in which the model was continuously nudged to the imposed SST forcing. This paper provides an overview of the experiments and some initial results focusing on the responses to the leading patterns of annual mean SST variability consisting of a Pacific El Nino/Southern Oscillation (ENSO)-like pattern, a pattern that resembles the Atlantic Multi-decadal Oscillation (AMO), and a global trend pattern. One of the key findings is that all the AGCMs produce broadly similar (though different in detail) precipitation responses to the Pacific forcing pattern, with a cold Pacific leading to reduced precipitation and a warm Pacific leading to enhanced precipitation over most of the United States. While the response to the Atlantic pattern is less robust, there is general agreement among the models that the largest precipitation response over the U.S. tends to occur when the two oceans have anomalies of opposite sign. That is, a cold Pacific and warm Atlantic tend to produce the largest precipitation reductions, whereas a warm Pacific and cold Atlantic tend to produce the greatest precipitation enhancements. Further analysis of the response over the U.S. to the Pacific forcing highlights a number of

  9. Mercury methylation, export and bioaccumulation in rice agriculture - model results from comparative and experimental studies in 3 regions of the California Delta, USA

    Science.gov (United States)

    Windham-Myers, L.; Fleck, J.; Eagles-Smith, C.; Ackerman, J.

    2013-12-01

    Seasonally flooded wetland ecosystems are often poised for mercury (Hg) methylation, thus becoming sources of methylmercury (MeHg) to in situ and downstream biota. The seasonal flooding associated with cultivation of rice (Oryza sativa) also generates MeHg, which may be stored in sediment or plants, bioaccumulated into fauna, degraded or exported, depending on hydrologic and seasonal conditions. While many U.S. waters are regulated for total Hg concentrations based on fish targets, California's Sacramento-San Joaquin Delta (Delta) will soon implement the first MeHg total maximum daily load (TMDL) control program. Since 2007, a conceptual model (DRERIP-MCM) and several ecosystem-level studies have been advanced to better understand the mechanisms behind Hg methylation, export and bioaccumulation within Delta wetlands, including rice agriculture. Three Delta rice-growing regions (Yolo Bypass, Cosumnes River, Central Delta) of varied soil characteristics, mining influences and hydrology, were monitored over full crop years to evaluate annual MeHg dynamics. In addition to fish tissue Hg accumulation, a broad suite of biogeochemical and hydrologic indices were assessed and compared between wetland types, seasons, and regions. In general, Delta rice fields were found to export MeHg during the post-harvest winter season, and promote MeHg uptake in fish and rice grain during the summer growing season. As described in a companion presentation (Eagles-Smith et al., this session), the experimental Cosumnes River study suggests that rice-derived dissolved organic carbon (DOC) fuels MeHg production and uptake into aquatic foodwebs. Explicit DRERIP-MCM linkages for the role of rice-DOC in MeHg production, export and bioaccumulation were verified across two summers (2011, 2012): rice biomass and root productivity influenced porewater DOC availability and microbial processes, which drove sediment MeHg production and flux to surface water, promoting MeHg bioaccumulation in fish

  10. Information Uncertainty to Compare Qualitative Reasoning Security Risk Assessment Results

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, Gregory M [Los Alamos National Laboratory; Key, Brian P [Los Alamos National Laboratory; Zerkle, David K [Los Alamos National Laboratory; Shevitz, Daniel W [Los Alamos National Laboratory

    2009-01-01

    The security risk associated with malevolent acts such as those of terrorism are often void of the historical data required for a traditional PRA. Most information available to conduct security risk assessments for these malevolent acts is obtained from subject matter experts as subjective judgements. Qualitative reasoning approaches such as approximate reasoning and evidential reasoning are useful for modeling the predicted risk from information provided by subject matter experts. Absent from these approaches is a consistent means to compare the security risk assessment results. Associated with each predicted risk reasoning result is a quantifiable amount of information uncertainty which can be measured and used to compare the results. This paper explores using entropy measures to quantify the information uncertainty associated with conflict and non-specificity in the predicted reasoning results. The measured quantities of conflict and non-specificity can ultimately be used to compare qualitative reasoning results which are important in triage studies and ultimately resource allocation. Straight forward extensions of previous entropy measures are presented here to quantify the non-specificity and conflict associated with security risk assessment results obtained from qualitative reasoning models.

  11. RESULTS OF THE SHORT COMPARATIVE ANALYSIS OF MATHEMATICAL MODELS OF INFLUENCE OF THE IONOSPHERE OF THE EARTH ON ULTRA BROADBAND SIGNALS X-RANGE

    Directory of Open Access Journals (Sweden)

    M. M. Kasperovich

    2015-01-01

    Full Text Available For range portrait formation at usage ultrabroadband linearly frequency-modulated signal in radar it is necessary to consider all distortions of an electromagnetic wave on a radio route. At observation over circumterraneousobjects the signal transits through an ionosphere. The electromagnetic wave in it will be exposed to non-linearity distortions, which transform of signal time structure. It leads to distance error origin. For its compensating it is necessary to use the mathematical model of signal distortions in an ionosphere.

  12. Comparing linear probability model coefficients across groups

    DEFF Research Database (Denmark)

    Holm, Anders; Ejrnæs, Mette; Karlson, Kristian Bernt

    2015-01-01

    This article offers a formal identification analysis of the problem in comparing coefficients from linear probability models between groups. We show that differences in coefficients from these models can result not only from genuine differences in effects, but also from differences in one or more...... of the following three components: outcome truncation, scale parameters and distributional shape of the predictor variable. These results point to limitations in using linear probability model coefficients for group comparisons. We also provide Monte Carlo simulations and real examples to illustrate...... these limitations, and we suggest a restricted approach to using linear probability model coefficients in group comparisons....

  13. Comparative study of void fraction models

    International Nuclear Information System (INIS)

    Borges, R.C.; Freitas, R.L.

    1985-01-01

    Some models for the calculation of void fraction in water in sub-cooled boiling and saturated vertical upward flow with forced convection have been selected and compared with experimental results in the pressure range of 1 to 150 bar. In order to know the void fraction axial distribution it is necessary to determine the net generation of vapour and the fluid temperature distribution in the slightly sub-cooled boiling region. It was verified that the net generation of vapour was well represented by the Saha-Zuber model. The selected models for the void fraction calculation present adequate results but with a tendency to super-estimate the experimental results, in particular the homogeneous models. The drift flux model is recommended, followed by the Armand and Smith models. (F.E.) [pt

  14. VEMAP 1: Selected Model Results

    Data.gov (United States)

    National Aeronautics and Space Administration — The Vegetation/Ecosystem Modeling and Analysis Project (VEMAP) was a multi-institutional, international effort addressing the response of biogeography and...

  15. Comparing Results from Constant Comparative and Computer Software Methods: A Reflection about Qualitative Data Analysis

    Science.gov (United States)

    Putten, Jim Vander; Nolen, Amanda L.

    2010-01-01

    This study compared qualitative research results obtained by manual constant comparative analysis with results obtained by computer software analysis of the same data. An investigated about issues of trustworthiness and accuracy ensued. Results indicated that the inductive constant comparative data analysis generated 51 codes and two coding levels…

  16. VEMAP 1: Selected Model Results

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: The Vegetation/Ecosystem Modeling and Analysis Project (VEMAP) was a multi-institutional, international effort addressing the response of biogeography and...

  17. Results of steel containment vessel model test

    International Nuclear Information System (INIS)

    Luk, V.K.; Ludwigsen, J.S.; Hessheimer, M.F.; Komine, Kuniaki; Matsumoto, Tomoyuki; Costello, J.F.

    1998-05-01

    A series of static overpressurization tests of scale models of nuclear containment structures is being conducted by Sandia National Laboratories for the Nuclear Power Engineering Corporation of Japan and the US Nuclear Regulatory Commission. Two tests are being conducted: (1) a test of a model of a steel containment vessel (SCV) and (2) a test of a model of a prestressed concrete containment vessel (PCCV). This paper summarizes the conduct of the high pressure pneumatic test of the SCV model and the results of that test. Results of this test are summarized and are compared with pretest predictions performed by the sponsoring organizations and others who participated in a blind pretest prediction effort. Questions raised by this comparison are identified and plans for posttest analysis are discussed

  18. Comparing the Discrete and Continuous Logistic Models

    Science.gov (United States)

    Gordon, Sheldon P.

    2008-01-01

    The solutions of the discrete logistic growth model based on a difference equation and the continuous logistic growth model based on a differential equation are compared and contrasted. The investigation is conducted using a dynamic interactive spreadsheet. (Contains 5 figures.)

  19. The Danish national passenger modelModel specification and results

    DEFF Research Database (Denmark)

    Rich, Jeppe; Hansen, Christian Overgaard

    2016-01-01

    , the paper provides a description of a large-scale forecast model with a discussion of the linkage between population synthesis, demand and assignment. Secondly, the paper gives specific attention to model specification and in particular choice of functional form and cost-damping. Specifically we suggest...... a family of logarithmic spline functions and illustrate how it is applied in the model. Thirdly and finally, we evaluate model sensitivity and performance by evaluating the distance distribution and elasticities. In the paper we present results where the spline-function is compared with more traditional...... function types and it is indicated that the spline-function provides a better description of the data. Results are also provided in the form of a back-casting exercise where the model is tested in a back-casting scenario to 2002....

  20. Is it Worth Comparing Different Bankruptcy Models?

    Directory of Open Access Journals (Sweden)

    Miroslava Dolejšová

    2015-01-01

    Full Text Available The aim of this paper is to compare the performance of small enterprises in the Zlín and Olomouc Regions. These enterprises were assessed using the Altman Z-Score model, the IN05 model, the Zmijewski model and the Springate model. The batch selected for this analysis included 16 enterprises from the Zlín Region and 16 enterprises from the Olomouc Region. Financial statements subjected to the analysis are from 2006 and 2010. The statistical data analysis was performed using the one-sample z-test for proportions and the paired t-test. The outcomes of the evaluation run using the Altman Z-Score model, the IN05 model and the Springate model revealed the enterprises to be financially sound, but the Zmijewski model identified them as being insolvent. The one-sample z-test for proportions confirmed that at least 80% of these enterprises show a sound financial condition. A comparison of all models has emphasized the substantial difference produced by the Zmijewski model. The paired t-test showed that the financial performance of small enterprises had remained the same during the years involved. It is recommended that small enterprises assess their financial performance using two different bankruptcy models. They may wish to combine the Zmijewski model with any bankruptcy model (the Altman Z-Score model, the IN05 model or the Springate model to ensure a proper method of analysis.

  1. Wellness Model of Supervision: A Comparative Analysis

    Science.gov (United States)

    Lenz, A. Stephen; Sangganjanavanich, Varunee Faii; Balkin, Richard S.; Oliver, Marvarene; Smith, Robert L.

    2012-01-01

    This quasi-experimental study compared the effectiveness of the Wellness Model of Supervision (WELMS; Lenz & Smith, 2010) with alternative supervision models for developing wellness constructs, total personal wellness, and helping skills among counselors-in-training. Participants were 32 master's-level counseling students completing their…

  2. Comparing models of Red Knot population dynamics

    Science.gov (United States)

    McGowan, Conor P.

    2015-01-01

    Predictive population modeling contributes to our basic scientific understanding of population dynamics, but can also inform management decisions by evaluating alternative actions in virtual environments. Quantitative models mathematically reflect scientific hypotheses about how a system functions. In Delaware Bay, mid-Atlantic Coast, USA, to more effectively manage horseshoe crab (Limulus polyphemus) harvests and protect Red Knot (Calidris canutus rufa) populations, models are used to compare harvest actions and predict the impacts on crab and knot populations. Management has been chiefly driven by the core hypothesis that horseshoe crab egg abundance governs the survival and reproduction of migrating Red Knots that stopover in the Bay during spring migration. However, recently, hypotheses proposing that knot dynamics are governed by cyclical lemming dynamics garnered some support in data analyses. In this paper, I present alternative models of Red Knot population dynamics to reflect alternative hypotheses. Using 2 models with different lemming population cycle lengths and 2 models with different horseshoe crab effects, I project the knot population into the future under environmental stochasticity and parametric uncertainty with each model. I then compare each model's predictions to 10 yr of population monitoring from Delaware Bay. Using Bayes' theorem and model weight updating, models can accrue weight or support for one or another hypothesis of population dynamics. With 4 models of Red Knot population dynamics and only 10 yr of data, no hypothesis clearly predicted population count data better than another. The collapsed lemming cycle model performed best, accruing ~35% of the model weight, followed closely by the horseshoe crab egg abundance model, which accrued ~30% of the weight. The models that predicted no decline or stable populations (i.e. the 4-yr lemming cycle model and the weak horseshoe crab effect model) were the most weakly supported.

  3. Revisiting Runoff Model Calibration: Airborne Snow Observatory Results Allow Improved Modeling Results

    Science.gov (United States)

    McGurk, B. J.; Painter, T. H.

    2014-12-01

    Deterministic snow accumulation and ablation simulation models are widely used by runoff managers throughout the world to predict runoff quantities and timing. Model fitting is typically based on matching modeled runoff volumes and timing with observed flow time series at a few points in the basin. In recent decades, sparse networks of point measurements of the mountain snowpacks have been available to compare with modeled snowpack, but the comparability of results from a snow sensor or course to model polygons of 5 to 50 sq. km is suspect. However, snowpack extent, depth, and derived snow water equivalent have been produced by the NASA/JPL Airborne Snow Observatory (ASO) mission for spring of 20013 and 2014 in the Tuolumne River basin above Hetch Hetchy Reservoir. These high-resolution snowpack data have exposed the weakness in a model calibration based on runoff alone. The U.S. Geological Survey's Precipitation Runoff Modeling System (PRMS) calibration that was based on 30-years of inflow to Hetch Hetchy produces reasonable inflow results, but modeled spatial snowpack location and water quantity diverged significantly from the weekly measurements made by ASO during the two ablation seasons. The reason is that the PRMS model has many flow paths, storages, and water transfer equations, and a calibrated outflow time series can be right for many wrong reasons. The addition of a detailed knowledge of snow extent and water content constrains the model so that it is a better representation of the actual watershed hydrology. The mechanics of recalibrating PRMS to the ASO measurements will be described, and comparisons in observed versus modeled flow for both a small subbasin and the entire Hetch Hetchy basin will be shown. The recalibrated model provided a bitter fit to the snowmelt recession, a key factor for water managers as they balance declining inflows with demand for power generation and ecosystem releases during the final months of snow melt runoff.

  4. Comparing flood loss models of different complexity

    Science.gov (United States)

    Schröter, Kai; Kreibich, Heidi; Vogel, Kristin; Riggelsen, Carsten; Scherbaum, Frank; Merz, Bruno

    2013-04-01

    Any deliberation on flood risk requires the consideration of potential flood losses. In particular, reliable flood loss models are needed to evaluate cost-effectiveness of mitigation measures, to assess vulnerability, for comparative risk analysis and financial appraisal during and after floods. In recent years, considerable improvements have been made both concerning the data basis and the methodological approaches used for the development of flood loss models. Despite of that, flood loss models remain an important source of uncertainty. Likewise the temporal and spatial transferability of flood loss models is still limited. This contribution investigates the predictive capability of different flood loss models in a split sample cross regional validation approach. For this purpose, flood loss models of different complexity, i.e. based on different numbers of explaining variables, are learned from a set of damage records that was obtained from a survey after the Elbe flood in 2002. The validation of model predictions is carried out for different flood events in the Elbe and Danube river basins in 2002, 2005 and 2006 for which damage records are available from surveys after the flood events. The models investigated are a stage-damage model, the rule based model FLEMOps+r as well as novel model approaches which are derived using data mining techniques of regression trees and Bayesian networks. The Bayesian network approach to flood loss modelling provides attractive additional information concerning the probability distribution of both model predictions and explaining variables.

  5. Comparative Analysis of Results of Online and Offline Customer Satisfaction

    Directory of Open Access Journals (Sweden)

    Jovović Milorad

    2017-05-01

    Full Text Available The logic that customer satisfaction is the starting point of marketing and business activities is based on the assumption that customer satisfaction leads to customer loyalty, keeping in mind all of the positive effects that customer loyalty has on business success of an organization. Because of this, marketing and management theory and practice dedicate particular attention to the concepts of customer satisfaction and loyalty. In this paper we will use the surveys of customers of banking services not only to show the levels of their satisfaction and loyalty, but also to make a comparative analysis of data obtained through online and offline research. This approach was made possible because the research was carried out on a sample which was divided in two groups. All of the participants answered the questions from a unique questionnaire, however, one group took the survey via the Internet (online while data from the other group of participants was collected in the field by using printed questionnaires (offline. The findings of the comparative analysis of online and offline survey results are presented in the final part of the paper.

  6. Comparative Study of Bancruptcy Prediction Models

    Directory of Open Access Journals (Sweden)

    Isye Arieshanti

    2013-09-01

    Full Text Available Early indication of bancruptcy is important for a company. If companies aware of  potency of their bancruptcy, they can take a preventive action to anticipate the bancruptcy. In order to detect the potency of a bancruptcy, a company can utilize a a model of bancruptcy prediction. The prediction model can be built using a machine learning methods. However, the choice of machine learning methods should be performed carefully. Because the suitability of a model depends on the problem specifically. Therefore, in this paper we perform a comparative study of several machine leaning methods for bancruptcy prediction. According to the comparative study, the performance of several models that based on machine learning methods (k-NN, fuzzy k-NN, SVM, Bagging Nearest Neighbour SVM, Multilayer Perceptron(MLP, Hybrid of MLP + Multiple Linear Regression, it can be showed that fuzzy k-NN method achieve the best performance with accuracy 77.5%

  7. Comparing coefficients of nested nonlinear probability models

    DEFF Research Database (Denmark)

    Kohler, Ulrich; Karlson, Kristian Bernt; Holm, Anders

    2011-01-01

    In a series of recent articles, Karlson, Holm and Breen have developed a method for comparing the estimated coeffcients of two nested nonlinear probability models. This article describes this method and the user-written program khb that implements the method. The KHB-method is a general decomposi......In a series of recent articles, Karlson, Holm and Breen have developed a method for comparing the estimated coeffcients of two nested nonlinear probability models. This article describes this method and the user-written program khb that implements the method. The KHB-method is a general...

  8. Pancreaticojejunostomy vs. pancreaticogastrostomy following pancreaticoduodenectomy: results of comparative study.

    Science.gov (United States)

    Makni, A; Bedioui, H; Jouini, M; Chebbi, F; Ksantini, R; Fetirich, F; Rebai, W; Daghfous, A; Ayedi, S; Kacem, M; Ben Safta, Z

    2011-08-01

    Several techniques have been proposed for reconstructing pancreatico-digestive continuity, which the first goal is reducing the rate of pancreatic leakage after pancreaticoduodenectomy. Only a limited number studies have been carried out. Our objective is to compare the results of pancreaticojejunostomy versus pancreaticogastrostomy following pancreaticoduodenectomy. This is a retrospective and comparative study about 80 patients who underwent pancreaticoduodenectomy. These patients were divided into two groups: pancreaticojejunostomy (group PJ) and pancreaticogastrostomy (group PG). The PJ group included 39 patients, while 41 patients were included in the PG group. There were no differences between the two groups concerning: patients' demographics, risk factors, indication, mean duration of surgery, texture of pancreatic tissue, need for intraoperative blood transfusion and postoperative prophylactic octreotide. Overall, the mortality postoperative rate was 7.5% (N.=6), the incidence of surgical complications was 50% (51.3% in PJ, 48.8% in PG; P=0.823, not significant). Pancreatic fistula was the most frequent complication, occurring in 17.5% of patients (25.6% in PJ and 9.8% in PG; P=0.062, almost significant). 7.7% of patients who underwent PJ and 14.6% of patients who underwent PG required a second surgical intervention (P=0.326, not significant). There were no differences between the two groups PG and PJ concerning: Postoperative hemorrhage (P=0.63), biliary fistula (P=0.09), acute pancreatitis (P=0.95), delayed gastric emptying (P=0.33). The mean postoperative hospitalisation period stay was similar in both groups (P=0.63) There were not any significant differences between the two groups in the overall postoperative complication rate, the incidence of postoperative haemorrhage, biliary fistula, acute pancreatitis, and delayed.

  9. Scale Model Thruster Acoustic Measurement Results

    Science.gov (United States)

    Vargas, Magda; Kenny, R. Jeremy

    2013-01-01

    The Space Launch System (SLS) Scale Model Acoustic Test (SMAT) is a 5% scale representation of the SLS vehicle, mobile launcher, tower, and launch pad trench. The SLS launch propulsion system will be comprised of the Rocket Assisted Take-Off (RATO) motors representing the solid boosters and 4 Gas Hydrogen (GH2) thrusters representing the core engines. The GH2 thrusters were tested in a horizontal configuration in order to characterize their performance. In Phase 1, a single thruster was fired to determine the engine performance parameters necessary for scaling a single engine. A cluster configuration, consisting of the 4 thrusters, was tested in Phase 2 to integrate the system and determine their combined performance. Acoustic and overpressure data was collected during both test phases in order to characterize the system's acoustic performance. The results from the single thruster and 4- thuster system are discussed and compared.

  10. Comparative test results for two ODE solvers: EPISODE and GEAR

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, G.D.; Hindmarsh, A.C.; Jackson, K.R.; Brown, H.G.

    1977-03-01

    This is a sequel to the paper ''A comparison of two ODE codes: GEAR and EPISODE,'' and is concerned with the testing of two superficially similar ODE packages, GEAR and EPISODE. Fourteen basic test problems, some with several cases, are the basis for the testing. These problems represent several types--nonlinear systems with real and complex eigenvalues, linear systems with varied diagonal dominance, linear scalar problems, stiff and nonstiff problems, chemical kinetics with and without diurnal effect, and systems arising from the use of the numerical method of lines. Some problems are included in order to examine the options and error returns. The test results are presented in two forms: raw output and a comparative display of operation counts and of timings for the best method in the GEAR package and the best method in the EPISODE package. This approach allows a comparison of the consequences of the fixed-step interpolate strategy (GEAR) for changing step size against the truly variable step size strategy (EPISODE). It is concluded that EPISODE is generally faster than GEAR for problems involving wave fronts or transients on the interior of the interval of integration. For linear or simply decaying problems, these roles are usually reversed. 19 figures, 116 tables.

  11. Modeling and Field Results from Seismic Stimulation

    International Nuclear Information System (INIS)

    Majer, E.; Pride, S.; Lo, W.; Daley, T.; Nakagawa, Seiji; Sposito, Garrison; Roberts, P.

    2006-01-01

    Modeling the effect of seismic stimulation employing Maxwell-Boltzmann theory shows that the important component of stimulation is mechanical rather than fluid pressure effects. Modeling using Biot theory (two phases) shows that the pressure effects diffuse too quickly to be of practical significance. Field data from actual stimulation will be shown to compare to theory

  12. Commentary: Monotremes and marsupials: Comparative models to ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Biosciences; Volume 37; Issue 4. Commentary: Monotremes and marsupials: Comparative models to better understand the function of milk. Sanjana Kuruppath Swathi Bisana Julie A Sharp Christophe Lefevre Satish Kumar Kevin R Nicholas. Volume 37 Issue 4 September 2012 pp 581-588 ...

  13. Making the results of bottom-up energy savings comparable

    Directory of Open Access Journals (Sweden)

    Moser Simon

    2012-01-01

    Full Text Available The Energy Service Directive (ESD has pushed forward the issue of energy savings calculations without clarifying the methodological basis. Savings achieved in the Member States are calculated with rather non-transparent and hardly comparable Bottom-up (BU methods. This paper develops the idea of parallel evaluation tracks separating the Member States’ issue of ESD verification and comparable savings calculations. Comparability is ensured by developing a standardised BU calculation kernel for different energy efficiency improvement (EEI actions which simultaneously depicts the different calculation options in a structured way (e.g. baseline definition, system boundaries, double counting. Due to the heterogeneity of BU calculations the approach requires a central database where Member States feed in input data on BU actions according to a predefined structure. The paper demonstrates the proposed approach including a concrete example of application.

  14. Comparing numerically exact and modelled static friction

    Directory of Open Access Journals (Sweden)

    Krengel Dominik

    2017-01-01

    Full Text Available Currently there exists no mechanically consistent “numerically exact” implementation of static and dynamic Coulomb friction for general soft particle simulations with arbitrary contact situations in two or three dimension, but only along one dimension. We outline a differential-algebraic equation approach for a “numerically exact” computation of friction in two dimensions and compare its application to the Cundall-Strack model in some test cases.

  15. Comparative analysis of Goodwin's business cycle models

    Science.gov (United States)

    Antonova, A. O.; Reznik, S.; Todorov, M. D.

    2016-10-01

    We compare the behavior of solutions of Goodwin's business cycle equation in the form of neutral delay differential equation with fixed delay (NDDE model) and in the form of the differential equations of 3rd, 4th and 5th orders (ODE model's). Such ODE model's (Taylor series expansion of NDDE in powers of θ) are proposed in N. Dharmaraj and K. Vela Velupillai [6] for investigation of the short periodic sawthooth oscillations in NDDE. We show that the ODE's of 3rd, 4th and 5th order may approximate the asymptotic behavior of only main Goodwin's mode, but not the sawthooth modes. If the order of the Taylor series expansion exceeds 5, then the approximate ODE becomes unstable independently of time lag θ.

  16. A Comparative Analysis of Task Modeling Notations

    Directory of Open Access Journals (Sweden)

    Jean Vanderdonckt

    2012-03-01

    paper a comparative analysis of selected models involving multiple users in an interaction is provided in order to identify concepts which are underexplored in today's multi-user interaction task modeling. This comparative analysis is based on three families of criteria: information criteria, conceptual coverage, and expressiveness. Merging the meta-models of the selected models enables to come up with a broader meta-model that could be instantiated in most situations involving multi-user interaction, like workflow information systems, CSCW.

  17. Comparative Study of Smeared Cracking Models for Concrete Structures

    Directory of Open Access Journals (Sweden)

    Samuel Silva Penna

    2014-02-01

    Full Text Available The article shows how the constitutive modeling of concrete has evolved since the initial attempts to characterize the medium cracked as continuous, moving from smeared cracking, damage and microplane models, until the current tendency to design different models according to a single theoretical framework. A generic formulation for smeared cracking models, including fixed and rotational models, as well as degradation in tension and in compression, is provided. Using this formulation, three models are generated by specifying the laws of degradation. A comparative study of models, based on computer simulations of a beam subjected to shear at four points, is presented. The results are compared, between themselves and with experimental results, providing a critical analysis of the models.

  18. Comparing models of offensive cyber operations

    CSIR Research Space (South Africa)

    Grant, T

    2015-10-01

    Full Text Available would be needed by a Cyber Security Operations Centre in order to perform offensive cyber operations?". The analysis was performed, using as a springboard seven models of cyber-attack, and resulted in the development of what is described as a canonical...

  19. Comparative PGAA and NAA results of geological samples and standards

    International Nuclear Information System (INIS)

    Gmeling, K.; Simonits, A.; Sziklai, L.I.; Parkanyi, D.

    2014-01-01

    Concentrations of major and trace elements in volcanic rock and soil samples, including geological standard reference materials, were determined by neutron activation analysis (NAA) and prompt gamma activation analysis (PGAA), both using the k 0-standardization method. The paper highlights the different experimental procedures, such as sample preparation, data collection and spectrum evaluation. In geological samples, PGAA gives precise results for major elements (Si, Ti, Al, Fe, Mn, Mg, Ca, Na, K and - as a unique method - for H), for some of the light trace elements as B and Cl, as well as for Sc, S, Cr, Co, Ni, Cd, Nd, Sm and Gd. NAA is sensitive for the rare earth elements, and for many major (Ti, Al, Fe, Mn, Mg, Ca, Na, K) and trace elements (e.g.: Sc, V, Cr, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Zr, As, Sb, Ce, Ba, Hf, Ta, W). For most major elements the results obtained by the two methods show good agreement. The comparison of the results obtained for trace elements is not always possible, since PGAA is less sensitive and concentrations are often below its detection limits. Nevertheless, the complementarity of NAA and PGAA allows nearly panoramic analysis of geological materials. (author)

  20. Comparative analysis of radiotherapeutic results in locally widespread laryngeal carcinomas

    International Nuclear Information System (INIS)

    Goldobenko, G.V.; Kudryavtseva, G.T.; Sidorchenkov, V.O.; Mardynskij, Yu.S.; Senyukov, M.V.

    1981-01-01

    The results of different procedures of radiotherapy of 118 patients with locally widespread laryngeal carcinomas are analyzed. 30 of them received a telegamma therapy, 20 a combined radiotherapy, 36 an electron therapy, 32 an electron therapy with synchronization of the tumor cell cycle by 5-fluorourazil. The therapeutic results were evaluated according to the regression extent of the tumor and to the duration of the period without recurrence. The best immediate effect was obtained by electron therapy (55.5 +- 8.3% of patients), in the other groups there was a complete regression of the tumor in 28-33% of the patients. Recurrences developed in the first 3 years in all patient groups with predominance in the first 2 years. A further tumor growth occurred after complete (about 40-54% of patients) as well as after partial regression of the tumor (about 78-86%). All groups showed the same late results independently of the method of treatment: 5 years and more 27.8-29.3% of the patients are living without recurrences. Radiation responses of the skin and of the mucosa developed significantly more seldom in electron and combined therapy. (author)

  1. A physiological production model for cacao : results of model simulations

    NARCIS (Netherlands)

    Zuidema, P.A.; Leffelaar, P.A.

    2002-01-01

    CASE2 is a physiological model for cocoa (Theobroma cacao L.) growth and yield. This report introduces the CAcao Simulation Engine for water-limited production in a non-technical way and presents simulation results obtained with the model.

  2. Comparative analysis of design models for concrete corbels

    Directory of Open Access Journals (Sweden)

    D. L. Araújo

    Full Text Available ABSTRACT The main objective of this paper is performing a comparative analysis of some design models for precast concrete corbels. For this, it was analyzed design models from Brazilian (NBR 9062 and European (EUROCODE 2 Codes and a US design handbook (PCI. Moreover, three analytical models showed in the literature are analyzed. The objective of this comparative is identifying the best design models to represent the failure load of concrete corbels by the tie yields or by the concrete crushing. Moreover, it is intended to evaluate the contribution of horizontal stirrups to resistance of concrete corbels. For this, a database was assembled from test results of concrete corbels carried out by several researchers and they are showed in the literature. The design models were applied to this database and from statistical tools, adjustments coefficients are recommended to be applied on these design models to take into account the results dispersion found in the analysis.

  3. Interpreting Results from the Multinomial Logit Model

    DEFF Research Database (Denmark)

    Wulff, Jesper

    2015-01-01

    This article provides guidelines and illustrates practical steps necessary for an analysis of results from the multinomial logit model (MLM). The MLM is a popular model in the strategy literature because it allows researchers to examine strategic choices with multiple outcomes. However, there seem...... to be systematic issues with regard to how researchers interpret their results when using the MLM. In this study, I present a set of guidelines critical to analyzing and interpreting results from the MLM. The procedure involves intuitive graphical representations of predicted probabilities and marginal effects...... suitable for both interpretation and communication of results. The pratical steps are illustrated through an application of the MLM to the choice of foreign market entry mode....

  4. Methods and models used in comparative risk studies

    International Nuclear Information System (INIS)

    Devooght, J.

    1983-01-01

    Comparative risk studies make use of a large number of methods and models based upon a set of assumptions incompletely formulated or of value judgements. Owing to the multidimensionality of risks and benefits, the economic and social context may notably influence the final result. Five classes of models are briefly reviewed: accounting of fluxes of effluents, radiation and energy; transport models and health effects; systems reliability and bayesian analysis; economic analysis of reliability and cost-risk-benefit analysis; decision theory in presence of uncertainty and multiple objectives. Purpose and prospect of comparative studies are assessed in view of probable diminishing returns for large generic comparisons [fr

  5. Comparing holographic dark energy models with statefinder

    International Nuclear Information System (INIS)

    Cui, Jing-Lei; Zhang, Jing-Fei

    2014-01-01

    We apply the statefinder diagnostic to the holographic dark energy models, including the original holographic dark energy (HDE) model, the new holographic dark energy model, the new agegraphic dark energy (NADE) model, and the Ricci dark energy model. In the low-redshift region the holographic dark energy models are degenerate with each other and with the ΛCDM model in the H(z) and q(z) evolutions. In particular, the HDE model is highly degenerate with the ΛCDM model, and in the HDE model the cases with different parameter values are also in strong degeneracy. Since the observational data are mainly within the low-redshift region, it is very important to break this lowredshift degeneracy in the H(z) and q(z) diagnostics by using some quantities with higher order derivatives of the scale factor. It is shown that the statefinder diagnostic r(z) is very useful in breaking the low-redshift degeneracies. By employing the statefinder diagnostic the holographic dark energy models can be differentiated efficiently in the low-redshift region. The degeneracy between the holographic dark energy models and the ΛCDM model can also be broken by this method. Especially for the HDE model, all the previous strong degeneracies appearing in the H(z) and q(z) diagnostics are broken effectively. But for the NADE model, the degeneracy between the cases with different parameter values cannot be broken, even though the statefinder diagnostic is used. A direct comparison of the holographic dark energy models in the r-s plane is also made, in which the separations between the models (including the ΛCDM model) can be directly measured in the light of the current values {r 0 , s 0 } of the models. (orig.)

  6. Comparative analysis of Vening-Meinesz Moritz isostatic models ...

    Indian Academy of Sciences (India)

    We compare three different numerical schemes of treating the Moho density contrast in gravimetric inverse problems for finding the Moho depths. The results are validated using the global crustal model. CRUST2.0, which is determined based purely on seismic data. Firstly, the gravimetric recovery of the. Moho depths is ...

  7. CMS standard model Higgs boson results

    Directory of Open Access Journals (Sweden)

    Garcia-Abia Pablo

    2013-11-01

    Full Text Available In July 2012 CMS announced the discovery of a new boson with properties resembling those of the long-sought Higgs boson. The analysis of the proton-proton collision data recorded by the CMS detector at the LHC, corresponding to integrated luminosities of 5.1 fb−1 at √s = 7 TeV and 19.6 fb−1 at √s = 8 TeV, confirm the Higgs-like nature of the new boson, with a signal strength associated with vector bosons and fermions consistent with the expectations for a standard model (SM Higgs boson, and spin-parity clearly favouring the scalar nature of the new boson. In this note I review the updated results of the CMS experiment.

  8. A comparative study of seven human cochlear filter models.

    Science.gov (United States)

    Saremi, Amin; Beutelmann, Rainer; Dietz, Mathias; Ashida, Go; Kretzberg, Jutta; Verhulst, Sarah

    2016-09-01

    Auditory models have been developed for decades to simulate characteristics of the human auditory system, but it is often unknown how well auditory models compare to each other or perform in tasks they were not primarily designed for. This study systematically analyzes predictions of seven publicly-available cochlear filter models in response to a fixed set of stimuli to assess their capabilities of reproducing key aspects of human cochlear mechanics. The following features were assessed at frequencies of 0.5, 1, 2, 4, and 8 kHz: cochlear excitation patterns, nonlinear response growth, frequency selectivity, group delays, signal-in-noise processing, and amplitude modulation representation. For each task, the simulations were compared to available physiological data recorded in guinea pigs and gerbils as well as to human psychoacoustics data. The presented results provide application-oriented users with comprehensive information on the advantages, limitations and computation costs of these seven mainstream cochlear filter models.

  9. Comparative Distributions of Hazard Modeling Analysis

    Directory of Open Access Journals (Sweden)

    Rana Abdul Wajid

    2006-07-01

    Full Text Available In this paper we present the comparison among the distributions used in hazard analysis. Simulation technique has been used to study the behavior of hazard distribution modules. The fundamentals of Hazard issues are discussed using failure criteria. We present the flexibility of the hazard modeling distribution that approaches to different distributions.

  10. Comparing models of offensive cyber operations

    CSIR Research Space (South Africa)

    Grant, T

    2012-03-01

    Full Text Available system, few represent target selection, attack planning, and Denial of Service attacks, and none specifically represent attack coordination within distributed groups. Finally, a canonical model has been constructed by rational reconstruction (Habermas... logical form? (Habermas, 1976). RR has been applied in computing research to redesign a seminal expert system (Cendrowski & Bramer, 1984) and to formalise Boyd?s (1996) Observe-Orient-Decide-Act (OODA) loop (Grant & Kooter, 2005). In the research...

  11. Immersive visualization of dynamic CFD model results

    International Nuclear Information System (INIS)

    Comparato, J.R.; Ringel, K.L.; Heath, D.J.

    2004-01-01

    With immersive visualization the engineer has the means for vividly understanding problem causes and discovering opportunities to improve design. Software can generate an interactive world in which collaborators experience the results of complex mathematical simulations such as computational fluid dynamic (CFD) modeling. Such software, while providing unique benefits over traditional visualization techniques, presents special development challenges. The visualization of large quantities of data interactively requires both significant computational power and shrewd data management. On the computational front, commodity hardware is outperforming large workstations in graphical quality and frame rates. Also, 64-bit commodity computing shows promise in enabling interactive visualization of large datasets. Initial interactive transient visualization methods and examples are presented, as well as development trends in commodity hardware and clustering. Interactive, immersive visualization relies on relevant data being stored in active memory for fast response to user requests. For large or transient datasets, data management becomes a key issue. Techniques for dynamic data loading and data reduction are presented as means to increase visualization performance. (author)

  12. Linkage of PRA models. Phase 1, Results

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C.L.; Knudsen, J.K.; Kelly, D.L.

    1995-12-01

    The goal of the Phase I work of the ``Linkage of PRA Models`` project was to postulate methods of providing guidance for US Nuclear Regulator Commission (NRC) personnel on the selection and usage of probabilistic risk assessment (PRA) models that are best suited to the analysis they are performing. In particular, methods and associated features are provided for (a) the selection of an appropriate PRA model for a particular analysis, (b) complementary evaluation tools for the analysis, and (c) a PRA model cross-referencing method. As part of this work, three areas adjoining ``linking`` analyses to PRA models were investigated: (a) the PRA models that are currently available, (b) the various types of analyses that are performed within the NRC, and (c) the difficulty in trying to provide a ``generic`` classification scheme to groups plants based upon a particular plant attribute.

  13. Engineering Glass Passivation Layers -Model Results

    Energy Technology Data Exchange (ETDEWEB)

    Skorski, Daniel C.; Ryan, Joseph V.; Strachan, Denis M.; Lepry, William C.

    2011-08-08

    The immobilization of radioactive waste into glass waste forms is a baseline process of nuclear waste management not only in the United States, but worldwide. The rate of radionuclide release from these glasses is a critical measure of the quality of the waste form. Over long-term tests and using extrapolations of ancient analogues, it has been shown that well designed glasses exhibit a dissolution rate that quickly decreases to a slow residual rate for the lifetime of the glass. The mechanistic cause of this decreased corrosion rate is a subject of debate, with one of the major theories suggesting that the decrease is caused by the formation of corrosion products in such a manner as to present a diffusion barrier on the surface of the glass. Although there is much evidence of this type of mechanism, there has been no attempt to engineer the effect to maximize the passivating qualities of the corrosion products. This study represents the first attempt to engineer the creation of passivating phases on the surface of glasses. Our approach utilizes interactions between the dissolving glass and elements from the disposal environment to create impermeable capping layers. By drawing from other corrosion studies in areas where passivation layers have been successfully engineered to protect the bulk material, we present here a report on mineral phases that are likely have a morphological tendency to encrust the surface of the glass. Our modeling has focused on using the AFCI glass system in a carbonate, sulfate, and phosphate rich environment. We evaluate the minerals predicted to form to determine the likelihood of the formation of a protective layer on the surface of the glass. We have also modeled individual ions in solutions vs. pH and the addition of aluminum and silicon. These results allow us to understand the pH and ion concentration dependence of mineral formation. We have determined that iron minerals are likely to form a complete incrustation layer and we plan

  14. Comparing National Water Model Inundation Predictions with Hydrodynamic Modeling

    Science.gov (United States)

    Egbert, R. J.; Shastry, A.; Aristizabal, F.; Luo, C.

    2017-12-01

    The National Water Model (NWM) simulates the hydrologic cycle and produces streamflow forecasts, runoff, and other variables for 2.7 million reaches along the National Hydrography Dataset for the continental United States. NWM applies Muskingum-Cunge channel routing which is based on the continuity equation. However, the momentum equation also needs to be considered to obtain better estimates of streamflow and stage in rivers especially for applications such as flood inundation mapping. Simulation Program for River NeTworks (SPRNT) is a fully dynamic model for large scale river networks that solves the full nonlinear Saint-Venant equations for 1D flow and stage height in river channel networks with non-uniform bathymetry. For the current work, the steady-state version of the SPRNT model was leveraged. An evaluation on SPRNT's and NWM's abilities to predict inundation was conducted for the record flood of Hurricane Matthew in October 2016 along the Neuse River in North Carolina. This event was known to have been influenced by backwater effects from the Hurricane's storm surge. Retrospective NWM discharge predictions were converted to stage using synthetic rating curves. The stages from both models were utilized to produce flood inundation maps using the Height Above Nearest Drainage (HAND) method which uses the local relative heights to provide a spatial representation of inundation depths. In order to validate the inundation produced by the models, Sentinel-1A synthetic aperture radar data in the VV and VH polarizations along with auxiliary data was used to produce a reference inundation map. A preliminary, binary comparison of the inundation maps to the reference, limited to the five HUC-12 areas of Goldsboro, NC, yielded that the flood inundation accuracies for NWM and SPRNT were 74.68% and 78.37%, respectively. The differences for all the relevant test statistics including accuracy, true positive rate, true negative rate, and positive predictive value were found

  15. Bayesian models for comparative analysis integrating phylogenetic uncertainty

    Science.gov (United States)

    2012-01-01

    Background Uncertainty in comparative analyses can come from at least two sources: a) phylogenetic uncertainty in the tree topology or branch lengths, and b) uncertainty due to intraspecific variation in trait values, either due to measurement error or natural individual variation. Most phylogenetic comparative methods do not account for such uncertainties. Not accounting for these sources of uncertainty leads to false perceptions of precision (confidence intervals will be too narrow) and inflated significance in hypothesis testing (e.g. p-values will be too small). Although there is some application-specific software for fitting Bayesian models accounting for phylogenetic error, more general and flexible software is desirable. Methods We developed models to directly incorporate phylogenetic uncertainty into a range of analyses that biologists commonly perform, using a Bayesian framework and Markov Chain Monte Carlo analyses. Results We demonstrate applications in linear regression, quantification of phylogenetic signal, and measurement error models. Phylogenetic uncertainty was incorporated by applying a prior distribution for the phylogeny, where this distribution consisted of the posterior tree sets from Bayesian phylogenetic tree estimation programs. The models were analysed using simulated data sets, and applied to a real data set on plant traits, from rainforest plant species in Northern Australia. Analyses were performed using the free and open source software OpenBUGS and JAGS. Conclusions Incorporating phylogenetic uncertainty through an empirical prior distribution of trees leads to more precise estimation of regression model parameters than using a single consensus tree and enables a more realistic estimation of confidence intervals. In addition, models incorporating measurement errors and/or individual variation, in one or both variables, are easily formulated in the Bayesian framework. We show that BUGS is a useful, flexible general purpose tool for

  16. Image based 3D city modeling : Comparative study

    Directory of Open Access Journals (Sweden)

    S. P. Singh

    2014-06-01

    result. For Large city reconstruction; CityEngine is a good product. Agisoft Photoscan software creates much better 3D model with good texture quality and automatic processing. So this image based comparative study is useful for 3D city user community. Thus this study will provide a good roadmap for geomatics user community to create photo-realistic virtual 3D city model by using image based techniques.

  17. Comparative evaluation of fiber fuse models

    International Nuclear Information System (INIS)

    Davis, D.D.; Mettler, S.C.; DiGiovanni, D.J.

    1997-01-01

    A phenomenon which results in the catastrophic destruction of the guiding properties of an optical fiber has been observed at laser power densities on the order of 3 x 10 6 watts/cm 2 in the core. This phenomenon is characterized by the propagation of a bright visible light from the point of initiation toward the laser source. The term 'fiber fuse' has been used because of the similarity in appearance to a burning fuse. The fiber fuse has been shown to start when the end of the fiber is contacted. It has also been initiated spontaneously from mechanical splices. This paper reports experimental data gathered on the fiber fuse and discusses their relationship to proposed physical mechanisms

  18. Coupled Michigan MHD - Rice Convection Model Results

    Science.gov (United States)

    de Zeeuw, D.; Sazykin, S.; Wolf, D.; Gombosi, T.; Powell, K.

    2002-12-01

    A new high performance Rice Convection Model (RCM) has been coupled to the adaptive-grid Michigan MHD model (BATSRUS). This fully coupled code allows us to self-consistently simulate the physics in the inner and middle magnetosphere. A study will be presented of the basic characteristics of the inner and middle magnetosphere in the context of a single coupled-code run for idealized storm inputs. The analysis will include region-2 currents, shielding of the inner magnetosphere, partial ring currents, pressure distribution, magnetic field inflation, and distribution of pV^gamma.

  19. Graphical interpretation of numerical model results

    International Nuclear Information System (INIS)

    Drewes, D.R.

    1979-01-01

    Computer software has been developed to produce high quality graphical displays of data from a numerical grid model. The code uses an existing graphical display package (DISSPLA) and overcomes some of the problems of both line-printer output and traditional graphics. The software has been designed to be flexible enough to handle arbitrarily placed computation grids and a variety of display requirements

  20. A CFD analysis of the actuator disc flow compared with momentum theory results

    Energy Technology Data Exchange (ETDEWEB)

    Aagaard Madsen, H. [Risoe National Laboratory, Roskilde (Denmark)

    1997-08-01

    The blade element momentum (BEM) model is still used in many aerodynamic and aeroelastic models for design and load calculations. This is due to its simplicity, robustness, computational speed and good accuracy for a wide range of applications. The question about accuracy is however closely connected to the airfoil section data and therefore correlation/lack of correlation with experimental results can both be due to the specific input data used and due to the induced velocity field predicted by the BEM method. It is also well-known that the BEM method for some applications is used under operational conditions that violates the assumptions made for the development of the model, e.g. operation in yaw and operation at high loading. The main objective with the present study is to investigate this part of the BEM method (the momentum strip theory MST) on which the determination of the induced velocities is based. This is done by comparing the results of the MST model with velocities predicted on basis of the Navier Stokes equations for the flow through an actuator disc. (au)

  1. Comparing Transformation Possibilities of Topological Functioning Model and BPMN in the Context of Model Driven Architecture

    Directory of Open Access Journals (Sweden)

    Solomencevs Artūrs

    2016-05-01

    Full Text Available The approach called “Topological Functioning Model for Software Engineering” (TFM4SE applies the Topological Functioning Model (TFM for modelling the business system in the context of Model Driven Architecture. TFM is a mathematically formal computation independent model (CIM. TFM4SE is compared to an approach that uses BPMN as a CIM. The comparison focuses on CIM modelling and on transformation to UML Sequence diagram on the platform independent (PIM level. The results show the advantages and drawbacks the formalism of TFM brings into the development.

  2. Ignalina NPP Safety Analysis: Models and Results

    International Nuclear Information System (INIS)

    Uspuras, E.

    1999-01-01

    Research directions, linked to safety assessment of the Ignalina NPP, of the scientific safety analysis group are presented: Thermal-hydraulic analysis of accidents and operational transients; Thermal-hydraulic assessment of Ignalina NPP Accident Localization System and other compartments; Structural analysis of plant components, piping and other parts of Main Circulation Circuit; Assessment of RBMK-1500 reactor core and other. Models and main works carried out last year are described. (author)

  3. Modeling clicks beyond the first result page

    NARCIS (Netherlands)

    Chuklin, A.; Serdyukov, P.; de Rijke, M.

    2013-01-01

    Most modern web search engines yield a list of documents of a fixed length (usually 10) in response to a user query. The next ten search results are usually available in one click. These documents either replace the current result page or are appended to the end. Hence, in order to examine more

  4. Microplasticity of MMC. Experimental results and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Maire, E. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France)); Lormand, G. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France)); Gobin, P.F. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France)); Fougeres, R. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France))

    1993-11-01

    The microplastic behavior of several MMC is investigated by means of tension and compression tests. This behavior is assymetric : the proportional limit is higher in tension than in compression but the work hardening rate is higher in compression. These differences are analysed in terms of maxium of the Tresca's shear stress at the interface (proportional limit) and of the emission of dislocation loops during the cooling (work hardening rate). On another hand, a model is proposed to calculate the value of the yield stress, describing the composite as a material composed of three phases : inclusion, unaffected matrix and matrix surrounding the inclusion having a gradient in the density of the thermally induced dilocations. (orig.).

  5. Comparing Numerical and Analog Models of Oblique Convergence With Nature

    Science.gov (United States)

    Koster, K.; Haq, S. S.; Flesch, L. M.

    2011-12-01

    Relative plate motion at convergent plate boundaries is rarely perfectly margin-normal, instead it typically exhibits some obliquity to the overlying plate. The resulting margin-parallel component of plate motion can have a considerable influence in determining the distribution and style of large-scale deformation at the margin. In accretionary prisms and fold and thrust belts oblique plate motion and the resulting deformation frequently results in spatially segregated dip-slip and strike-slip faulting in the deforming wedge. Analog modeling has demonstrated that the type of shearing structures that occur in response to this motion is strongly correlated with the vertical variation in rheology, where ductile layers at depth will localize strike-slip deformation. Additionally, we have performed numerical simulations where we solve force-balance equations for Stokes flow for oblique wedges with similar geometries and rheologies using the finite element software COMSOL. Using frictional and layered, frictional over viscous, rheologies we further constrain the role that rheological complexity plays in determining the style and distribution of deformation and of stress. In our numerical models, we have simulated a range of obliquities as well as layered rheologies to determine internal stresses in actively deforming wedges. Results from our numerical experiments are in agreement with available kinematic data from comparable analog experiments, suggesting our numerical method is also viable and suitable for modeling natural settings. Numerical models that simulated frictional wedges were characterized by diffusely distributed shear throughout the pro-wedge at low obliquities, and weakly partitioned strain, similar to analog results. However, the localization of shear in rheologically complex numerical models occurred across a narrower zone at comparable obliquities in both numerical and analog results, corresponding to the location where there the transition in basal

  6. Saccharomyces cerevisiae as a model organism: a comparative study.

    Directory of Open Access Journals (Sweden)

    Hiren Karathia

    Full Text Available BACKGROUND: Model organisms are used for research because they provide a framework on which to develop and optimize methods that facilitate and standardize analysis. Such organisms should be representative of the living beings for which they are to serve as proxy. However, in practice, a model organism is often selected ad hoc, and without considering its representativeness, because a systematic and rational method to include this consideration in the selection process is still lacking. METHODOLOGY/PRINCIPAL FINDINGS: In this work we propose such a method and apply it in a pilot study of strengths and limitations of Saccharomyces cerevisiae as a model organism. The method relies on the functional classification of proteins into different biological pathways and processes and on full proteome comparisons between the putative model organism and other organisms for which we would like to extrapolate results. Here we compare S. cerevisiae to 704 other organisms from various phyla. For each organism, our results identify the pathways and processes for which S. cerevisiae is predicted to be a good model to extrapolate from. We find that animals in general and Homo sapiens in particular are some of the non-fungal organisms for which S. cerevisiae is likely to be a good model in which to study a significant fraction of common biological processes. We validate our approach by correctly predicting which organisms are phenotypically more distant from S. cerevisiae with respect to several different biological processes. CONCLUSIONS/SIGNIFICANCE: The method we propose could be used to choose appropriate substitute model organisms for the study of biological processes in other species that are harder to study. For example, one could identify appropriate models to study either pathologies in humans or specific biological processes in species with a long development time, such as plants.

  7. GPM Microwave Imager Engineering Model Results

    Science.gov (United States)

    Newell, David; Krimchansky, Sergey

    2010-01-01

    The Global Precipitation Measurement (GPM) Microwave Imager (GMI) Instrument is being developed by Ball Aerospace and Technology Corporation (BATC) for the GPM program at NASA Goddard. The Global Precipitation Measurement (GPM) mission is an international effort managed by the National Aeronautics and Space Administration (NASA) to improve climate, weather, and hydro-meteorological predictions through more accurate and more frequent precipitation measurements. The GPM Microwave Imager (GMI) will be used to make calibrated, radiometric measurements from space at multiple microwave frequencies and polarizations. GMI will be placed on the GPM Core Spacecraft together with the Dualfrequency Precipitation Radar (DPR). The DPR is two-frequency precipitation measurement radar, which will operate in the Ku-band and Ka-band of the microwave spectrum. The Core Spacecraft will make radiometric and radar measurements of clouds and precipitation and will be the central element ofGPM's space segment. The data products from GPM will provide information concerning global precipitation on a frequent, near-global basis to meteorologists and scientists making weather forecasts and performing research on the global energy and water cycle, precipitation, hydrology, and related disciplines. In addition, radiometric measurements from GMI and radar measurements from the DPR will be used together to develop a retrieval transfer standard for the purpose of calibrating precipitation retrieval algorithms. This calibration standard will establish a reference against which other retrieval algorithms using only microwave radiometers (and without the benefit of the DPR) on other satellites in the GPM constellation will be compared.

  8. Comparative Studies of Population Synthesis Models in the ...

    Indian Academy of Sciences (India)

    Comparative Studies of Population Synthesis Models in the Framework of Modified Strömgren Filters ... The study conveys a good agreement of GALEV models with modified Strömgren colours but with poor UV model predictions and observed globular cluster data, while the spectroscopic models perform badly because of ...

  9. Comparative analysis of design models for concrete corbels

    OpenAIRE

    Araújo, D. L.; Silva Neto, A. P.; Lobo, F. A.; Debs, M. K. El

    2016-01-01

    ABSTRACT The main objective of this paper is performing a comparative analysis of some design models for precast concrete corbels. For this, it was analyzed design models from Brazilian (NBR 9062) and European (EUROCODE 2) Codes and a US design handbook (PCI). Moreover, three analytical models showed in the literature are analyzed. The objective of this comparative is identifying the best design models to represent the failure load of concrete corbels by the tie yields or by the concrete crus...

  10. Comparing Productivity Simulated with Inventory Data Using Different Modelling Technologies

    Science.gov (United States)

    Klopf, M.; Pietsch, S. A.; Hasenauer, H.

    2009-04-01

    The Lime Stone National Park in Austria was established in 1997 to protect sensible lime stone soils from degradation due to heavy forest management. Since 1997 the management activities were successively reduced and standing volume and coarse woody debris (CWD) increased and degraded soils began to recover. One option to study the rehabilitation process towards natural virgin forest state is the use of modelling technology. In this study we will test two different modelling approaches for their applicability to Lime Stone National Park. We will compare standing tree volume simulated resulting from (i) the individual tree growth model MOSES, and (ii) the species and management sensitive adaptation of the biogeochemical-mechanistic model Biome-BGC. The results from the two models are compared with filed observations form repeated permanent forest inventory plots of the Lime Stone National Park in Austria. The simulated CWD predictions of the BGC-model were compared with dead wood measurements (standing and lying dead wood) recorded at the permanent inventory plots. The inventory was established between 1994 and 1996 and remeasured from 2004 to 2005. For this analysis 40 plots of this inventory were selected which comprise the required dead wood components and are dominated by a single tree species. First we used the distance dependant individual tree growth model MOSES to derive the standing timber and the amount of mortality per hectare. MOSES is initialized with the inventory data at plot establishment and each sampling plot is treated as forest stand. The Biome-BGC is a process based biogeochemical model with extensions for Austrian tree species, a self initialization and a forest management tool. The initialization for the actual simulations with the BGC model was done as follows: We first used spin up runs to derive a balanced forest vegetation, similar to an undisturbed forest. Next we considered the management history of the past centuries (heavy clear cuts

  11. Hydroclimatology of the Nile: results from a regional climate model

    Directory of Open Access Journals (Sweden)

    Y. A. Mohamed

    2005-01-01

    Full Text Available This paper presents the result of the regional coupled climatic and hydrologic model of the Nile Basin. For the first time the interaction between the climatic processes and the hydrological processes on the land surface have been fully coupled. The hydrological model is driven by the rainfall and the energy available for evaporation generated in the climate model, and the runoff generated in the catchment is again routed over the wetlands of the Nile to supply moisture for atmospheric feedback. The results obtained are quite satisfactory given the extremely low runoff coefficients in the catchment. The paper presents the validation results over the sub-basins: Blue Nile, White Nile, Atbara river, the Sudd swamps, and the Main Nile for the period 1995 to 2000. Observational datasets were used to evaluate the model results including radiation, precipitation, runoff and evaporation data. The evaporation data were derived from satellite images over a major part of the Upper Nile. Limitations in both the observational data and the model are discussed. It is concluded that the model provides a sound representation of the regional water cycle over the Nile. The sources of atmospheric moisture to the basin, and location of convergence/divergence fields could be accurately illustrated. The model is used to describe the regional water cycle in the Nile basin in terms of atmospheric fluxes, land surface fluxes and land surface-climate feedbacks. The monthly moisture recycling ratio (i.e. locally generated/total precipitation over the Nile varies between 8 and 14%, with an annual mean of 11%, which implies that 89% of the Nile water resources originates from outside the basin physical boundaries. The monthly precipitation efficiency varies between 12 and 53%, and the annual mean is 28%. The mean annual result of the Nile regional water cycle is compared to that of the Amazon and the Mississippi basins.

  12. Results of the eruptive column model inter-comparison study

    Science.gov (United States)

    Costa, Antonio; Suzuki, Yujiro; Cerminara, M.; Devenish, Ben J.; Esposti Ongaro, T.; Herzog, Michael; Van Eaton, Alexa; Denby, L.C.; Bursik, Marcus; de' Michieli Vitturi, Mattia; Engwell, S.; Neri, Augusto; Barsotti, Sara; Folch, Arnau; Macedonio, Giovanni; Girault, F.; Carazzo, G.; Tait, S.; Kaminski, E.; Mastin, Larry G.; Woodhouse, Mark J.; Phillips, Jeremy C.; Hogg, Andrew J.; Degruyter, Wim; Bonadonna, Costanza

    2016-01-01

    This study compares and evaluates one-dimensional (1D) and three-dimensional (3D) numerical models of volcanic eruption columns in a set of different inter-comparison exercises. The exercises were designed as a blind test in which a set of common input parameters was given for two reference eruptions, representing a strong and a weak eruption column under different meteorological conditions. Comparing the results of the different models allows us to evaluate their capabilities and target areas for future improvement. Despite their different formulations, the 1D and 3D models provide reasonably consistent predictions of some of the key global descriptors of the volcanic plumes. Variability in plume height, estimated from the standard deviation of model predictions, is within ~ 20% for the weak plume and ~ 10% for the strong plume. Predictions of neutral buoyancy level are also in reasonably good agreement among the different models, with a standard deviation ranging from 9 to 19% (the latter for the weak plume in a windy atmosphere). Overall, these discrepancies are in the range of observational uncertainty of column height. However, there are important differences amongst models in terms of local properties along the plume axis, particularly for the strong plume. Our analysis suggests that the simplified treatment of entrainment in 1D models is adequate to resolve the general behaviour of the weak plume. However, it is inadequate to capture complex features of the strong plume, such as large vortices, partial column collapse, or gravitational fountaining that strongly enhance entrainment in the lower atmosphere. We conclude that there is a need to more accurately quantify entrainment rates, improve the representation of plume radius, and incorporate the effects of column instability in future versions of 1D volcanic plume models.

  13. COMPARING OF DEPOSIT MODEL AND LIFE INSURANCE MODEL IN MACEDONIA

    Directory of Open Access Journals (Sweden)

    TATJANA ATANASOVA-PACHEMSKA

    2016-02-01

    Full Text Available In conditions of the continuous decline of the interest rates for bank deposits, and at a time when uncertainty about the future is increasing, physical and legal persons have doubts how to secure their future or how and where to invest their funds and thus to “fertilize” and increase their savings. Individuals usually choose to put their savings in the bank for a certain period, and for that period to receive certain interest, or decide to invest their savings in different types of life insurance and thus to "take care" of their life, their future and the future of their families. In mathematics are developed many models that relate to the compounding and the insurance. This paper is a comparison of the deposit model and the model of life insurance

  14. Ionospheric topside models compared with experimental electron density profiles

    Directory of Open Access Journals (Sweden)

    S. M. Radicella

    2005-06-01

    Full Text Available Recently an increasing number of topside electron density profiles has been made available to the scientific community on the Internet. These data are important for ionospheric modeling purposes, since the experimental information on the electron density above the ionosphere maximum of ionization is very scarce. The present work compares NeQuick and IRI models with the topside electron density profiles available in the databases of the ISIS2, IK19 and Cosmos 1809 satellites. Experimental electron content from the F2 peak up to satellite height and electron densities at fixed heights above the peak have been compared under a wide range of different conditions. The analysis performed points out the behavior of the models and the improvements needed to be assessed to have a better reproduction of the experimental results. NeQuick topside is a modified Epstein layer, with thickness parameter determined by an empirical relation. It appears that its performance is strongly affected by this parameter, indicating the need for improvements of its formulation. IRI topside is based on Booker's approach to consider two parts with constant height gradients. It appears that this formulation leads to an overestimation of the electron density in the upper part of the profiles, and overestimation of TEC.

  15. Comparing pharmacophore models derived from crystallography and NMR ensembles

    Science.gov (United States)

    Ghanakota, Phani; Carlson, Heather A.

    2017-11-01

    NMR and X-ray crystallography are the two most widely used methods for determining protein structures. Our previous study examining NMR versus X-Ray sources of protein conformations showed improved performance with NMR structures when used in our Multiple Protein Structures (MPS) method for receptor-based pharmacophores (Damm, Carlson, J Am Chem Soc 129:8225-8235, 2007). However, that work was based on a single test case, HIV-1 protease, because of the rich data available for that system. New data for more systems are available now, which calls for further examination of the effect of different sources of protein conformations. The MPS technique was applied to Growth factor receptor bound protein 2 (Grb2), Src SH2 homology domain (Src-SH2), FK506-binding protein 1A (FKBP12), and Peroxisome proliferator-activated receptor-γ (PPAR-γ). Pharmacophore models from both crystal and NMR ensembles were able to discriminate between high-affinity, low-affinity, and decoy molecules. As we found in our original study, NMR models showed optimal performance when all elements were used. The crystal models had more pharmacophore elements compared to their NMR counterparts. The crystal-based models exhibited optimum performance only when pharmacophore elements were dropped. This supports our assertion that the higher flexibility in NMR ensembles helps focus the models on the most essential interactions with the protein. Our studies suggest that the "extra" pharmacophore elements seen at the periphery in X-ray models arise as a result of decreased protein flexibility and make very little contribution to model performance.

  16. Parmodel: a web server for automated comparative modeling of proteins.

    Science.gov (United States)

    Uchôa, Hugo Brandão; Jorge, Guilherme Eberhart; Freitas Da Silveira, Nelson José; Camera, João Carlos; Canduri, Fernanda; De Azevedo, Walter Filgueira

    2004-12-24

    Parmodel is a web server for automated comparative modeling and evaluation of protein structures. The aim of this tool is to help inexperienced users to perform modeling, assessment, visualization, and optimization of protein models as well as crystallographers to evaluate structures solved experimentally. It is subdivided in four modules: Parmodel Modeling, Parmodel Assessment, Parmodel Visualization, and Parmodel Optimization. The main module is the Parmodel Modeling that allows the building of several models for a same protein in a reduced time, through the distribution of modeling processes on a Beowulf cluster. Parmodel automates and integrates the main softwares used in comparative modeling as MODELLER, Whatcheck, Procheck, Raster3D, Molscript, and Gromacs. This web server is freely accessible at .

  17. Modeling Results For the ITER Cryogenic Fore Pump. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Pfotenhauer, John M. [University of Wisconsin, Madison, WI (United States); Zhang, Dongsheng [University of Wisconsin, Madison, WI (United States)

    2014-03-31

    A numerical model characterizing the operation of a cryogenic fore-pump (CFP) for ITER has been developed at the University of Wisconsin – Madison during the period from March 15, 2011 through June 30, 2014. The purpose of the ITER-CFP is to separate hydrogen isotopes from helium gas, both making up the exhaust components from the ITER reactor. The model explicitly determines the amount of hydrogen that is captured by the supercritical-helium-cooled pump as a function of the inlet temperature of the supercritical helium, its flow rate, and the inlet conditions of the hydrogen gas flow. Furthermore the model computes the location and amount of hydrogen captured in the pump as a function of time. Throughout the model’s development, and as a calibration check for its results, it has been extensively compared with the measurements of a CFP prototype tested at Oak Ridge National Lab. The results of the model demonstrate that the quantity of captured hydrogen is very sensitive to the inlet temperature of the helium coolant on the outside of the cryopump. Furthermore, the model can be utilized to refine those tests, and suggests methods that could be incorporated in the testing to enhance the usefulness of the measured data.

  18. GEOQUIMICO : an interactive tool for comparing sorption conceptual models (surface complexation modeling versus K[D])

    International Nuclear Information System (INIS)

    Hammond, Glenn E.; Cygan, Randall Timothy

    2007-01-01

    Within reactive geochemical transport, several conceptual models exist for simulating sorption processes in the subsurface. Historically, the K D approach has been the method of choice due to ease of implementation within a reactive transport model and straightforward comparison with experimental data. However, for modeling complex sorption phenomenon (e.g. sorption of radionuclides onto mineral surfaces), this approach does not systematically account for variations in location, time, or chemical conditions, and more sophisticated methods such as a surface complexation model (SCM) must be utilized. It is critical to determine which conceptual model to use; that is, when the material variation becomes important to regulatory decisions. The geochemical transport tool GEOQUIMICO has been developed to assist in this decision-making process. GEOQUIMICO provides a user-friendly framework for comparing the accuracy and performance of sorption conceptual models. The model currently supports the K D and SCM conceptual models. The code is written in the object-oriented Java programming language to facilitate model development and improve code portability. The basic theory underlying geochemical transport and the sorption conceptual models noted above is presented in this report. Explanations are provided of how these physicochemical processes are instrumented in GEOQUIMICO and a brief verification study comparing GEOQUIMICO results to data found in the literature is given

  19. Comparative examination of two methods for modeling autoimmune uveitis

    Directory of Open Access Journals (Sweden)

    Svetlana V. Aksenova

    2017-09-01

    Full Text Available Introduction: Uveitis is a disease of the uveal tract, characterized by a variety of causes and clinical manifestations. The internal antigens prevail often in the pathogenesis of the disease and develop the so-called autoimmune reactions. The uveitis treatment has an important medico-social significance because of the high prevalence of uveitis, the significant rate of the disease in young people, and high disability. The article compares the efficiency of two methods for modeling autoimmune uveitis. Materials and Methods: The research was conducted on 6 rabbits of the Chinchilla breed (12 eyes. Two models of experimental uveitis were reproduced on rabbits using normal horse serum during the research. A clinical examination of the inflammatory process course in the eyes was carried out by biomicroscopy using a slit lamp, and a direct ophthalmoscope. Histological and immunological examinations were conducted by the authors of the article. Results: The faster-reproducing and vivid clinical picture of the disease was observed in the second group. The obvious changes in the immunological status of the animals were noted also: an increase in the number of leukocytes, neutrophils, HCT-active neutrophils, and activation of phagocytosis. Discussion and Conclusions: The research has showed that the second model of uveitis is the most convenient working variant, which is characterized by high activity and duration of the inflammatory process in the eye.

  20. Family models: comparing and contrasting the Olson Circumplex Model with the Beavers Systems Model.

    Science.gov (United States)

    Beavers, W R; Voeller, M N

    1983-03-01

    There is an increasing interest in and need for family models. One such model is the Olson Circumplex Model, previously reported in this journal (18). This model is compared and contrasted with the Beavers Systems Model, which was also developed from empirical data and has had extensive use in family assessment. Though both are cross-sectional, process-oriented, and capable of providing structure for family research, we believe there are certain short-comings in the Olson model that make it less clinically useful than the Beavers Systems Model. These include definitional problems and a total reliance on curvilinear dimensions with a grid approach to family typology that does not acknowledge a separation/individuation continuum. Our model avoids these deficiencies and includes a continuum of functional competence that reflects the development and differentiation of many living systems, including the family.

  1. A comparative study of machine learning models for ethnicity classification

    Science.gov (United States)

    Trivedi, Advait; Bessie Amali, D. Geraldine

    2017-11-01

    This paper endeavours to adopt a machine learning approach to solve the problem of ethnicity recognition. Ethnicity identification is an important vision problem with its use cases being extended to various domains. Despite the multitude of complexity involved, ethnicity identification comes naturally to humans. This meta information can be leveraged to make several decisions, be it in target marketing or security. With the recent development of intelligent systems a sub module to efficiently capture ethnicity would be useful in several use cases. Several attempts to identify an ideal learning model to represent a multi-ethnic dataset have been recorded. A comparative study of classifiers such as support vector machines, logistic regression has been documented. Experimental results indicate that the logical classifier provides a much accurate classification than the support vector machine.

  2. Predicting the fate of biodiversity using species' distribution models: enhancing model comparability and repeatability.

    Directory of Open Access Journals (Sweden)

    Genoveva Rodríguez-Castañeda

    Full Text Available Species distribution modeling (SDM is an increasingly important tool to predict the geographic distribution of species. Even though many problems associated with this method have been highlighted and solutions have been proposed, little has been done to increase comparability among studies. We reviewed recent publications applying SDMs and found that seventy nine percent failed to report methods that ensure comparability among studies, such as disclosing the maximum probability range produced by the models and reporting on the number of species occurrences used. We modeled six species of Falco from northern Europe and demonstrate that model results are altered by (1 spatial bias in species' occurrence data, (2 differences in the geographic extent of the environmental data, and (3 the effects of transformation of model output to presence/absence data when applying thresholds. Depending on the modeling decisions, forecasts of the future geographic distribution of Falco ranged from range contraction in 80% of the species to no net loss in any species, with the best model predicting no net loss of habitat in Northern Europe. The fact that predictions of range changes in response to climate change in published studies may be influenced by decisions in the modeling process seriously hampers the possibility of making sound management recommendations. Thus, each of the decisions made in generating SDMs should be reported and evaluated to ensure conclusions and policies are based on the biology and ecology of the species being modeled.

  3. Students' Difficulties in Reading Images. Comparing Results from Four National Research Groups.

    Science.gov (United States)

    Pinto, Roser; Ametller, Jaume

    2002-01-01

    Compares the results of four studies made under the auspices of the Science Teacher Training in an Information Society (STTIS) project researching the difficulties students have in reading images. The studies are compared under such categories as pre-eminence of narrative readings, real-world versus symbolic elements, verbal elements, and…

  4. Hydrogen Station Cost Estimates: Comparing Hydrogen Station Cost Calculator Results with other Recent Estimates

    Energy Technology Data Exchange (ETDEWEB)

    Melaina, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Penev, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-09-01

    This report compares hydrogen station cost estimates conveyed by expert stakeholders through the Hydrogen Station Cost Calculation (HSCC) to a select number of other cost estimates. These other cost estimates include projections based upon cost models and costs associated with recently funded stations.

  5. Lithium-ion battery models: a comparative study and a model-based powerline communication

    Directory of Open Access Journals (Sweden)

    F. Saidani

    2017-09-01

    Full Text Available In this work, various Lithium-ion (Li-ion battery models are evaluated according to their accuracy, complexity and physical interpretability. An initial classification into physical, empirical and abstract models is introduced. Also known as white, black and grey boxes, respectively, the nature and characteristics of these model types are compared. Since the Li-ion battery cell is a thermo-electro-chemical system, the models are either in the thermal or in the electrochemical state-space. Physical models attempt to capture key features of the physical process inside the cell. Empirical models describe the system with empirical parameters offering poor analytical, whereas abstract models provide an alternative representation. In addition, a model selection guideline is proposed based on applications and design requirements. A complex model with a detailed analytical insight is of use for battery designers but impractical for real-time applications and in situ diagnosis. In automotive applications, an abstract model reproducing the battery behavior in an equivalent but more practical form, mainly as an equivalent circuit diagram, is recommended for the purpose of battery management. As a general rule, a trade-off should be reached between the high fidelity and the computational feasibility. Especially if the model is embedded in a real-time monitoring unit such as a microprocessor or a FPGA, the calculation time and memory requirements rise dramatically with a higher number of parameters. Moreover, examples of equivalent circuit models of Lithium-ion batteries are covered. Equivalent circuit topologies are introduced and compared according to the previously introduced criteria. An experimental sequence to model a 20 Ah cell is presented and the results are used for the purposes of powerline communication.

  6. Diabetes and quality of life: Comparing results from utility instruments and Diabetes-39.

    Science.gov (United States)

    Chen, Gang; Iezzi, Angelo; McKie, John; Khan, Munir A; Richardson, Jeff

    2015-08-01

    To compare the Diabetes-39 (D-39) with six multi-attribute utility (MAU) instruments (15D, AQoL-8D, EQ-5D, HUI3, QWB, and SF-6D), and to develop mapping algorithms which could be used to transform the D-39 scores into the MAU scores. Self-reported diabetes sufferers (N=924) and members of the healthy public (N=1760), aged 18 years and over, were recruited from 6 countries (Australia 18%, USA 18%, UK 17%, Canada 16%, Norway 16%, and Germany 15%). Apart from the QWB which was distributed normally, non-parametric rank tests were used to compare subgroup utilities and D-39 scores. Mapping algorithms were estimated using ordinary least squares (OLS) and generalised linear models (GLM). MAU instruments discriminated between diabetes patients and the healthy public; however, utilities varied between instruments. The 15D, SF-6D, AQoL-8D had the strongest correlations with the D-39. Except for the HUI3, there were significant differences by gender. Mapping algorithms based on the OLS estimator consistently gave better goodness-of-fit results. The mean absolute error (MAE) values ranged from 0.061 to 0.147, the root mean square error (RMSE) values 0.083 to 0.198, and the R-square statistics 0.428 and 0.610. Based on MAE and RMSE values the preferred mapping is D-39 into 15D. R-square statistics and the range of predicted utilities indicate the preferred mapping is D-39 into AQoL-8D. Utilities estimated from different MAU instruments differ significantly and the outcome of a study could depend upon the instrument used. The algorithms reported in this paper enable D-39 data to be mapped into utilities predicted from any of six instruments. This provides choice for those conducting cost-utility analyses. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Thermal-Chemical Model Of Subduction: Results And Tests

    Science.gov (United States)

    Gorczyk, W.; Gerya, T. V.; Connolly, J. A.; Yuen, D. A.; Rudolph, M.

    2005-12-01

    Seismic structures with strong positive and negative velocity anomalies in the mantle wedge above subduction zones have been interpreted as thermally and/or chemically induced phenomena. We have developed a thermal-chemical model of subduction, which constrains the dynamics of seismic velocity structure beneath volcanic arcs. Our simulations have been calculated over a finite-difference grid with (201×101) to (201×401) regularly spaced Eulerian points, using 0.5 million to 10 billion markers. The model couples numerical thermo-mechanical solution with Gibbs energy minimization to investigate the dynamic behavior of partially molten upwellings from slabs (cold plumes) and structures associated with their development. The model demonstrates two chemically distinct types of plumes (mixed and unmixed), and various rigid body rotation phenomena in the wedge (subduction wheel, fore-arc spin, wedge pin-ball). These thermal-chemical features strongly perturb seismic structure. Their occurrence is dependent on the age of subducting slab and the rate of subduction.The model has been validated through a series of test cases and its results are consistent with a variety of geological and geophysical data. In contrast to models that attribute a purely thermal origin for mantle wedge seismic anomalies, the thermal-chemical model is able to simulate the strong variations of seismic velocity existing beneath volcanic arcs which are associated with development of cold plumes. In particular, molten regions that form beneath volcanic arcs as a consequence of vigorous cold wet plumes are manifest by > 20% variations in the local Poisson ratio, as compared to variations of ~ 2% expected as a consequence of temperature variation within the mantle wedge.

  8. THE FLAT TAX - A COMPARATIVE STUDY OF THE EXISTING MODELS

    Directory of Open Access Journals (Sweden)

    Schiau (Macavei Laura - Liana

    2011-07-01

    Full Text Available In the two last decades the flat tax systems have spread all around the globe from East and Central Europe to Asia and Central America. Many specialists consider this phenomenon a real fiscal revolution, but others see it as a mistake as long as the new systems are just a feint of the true flat tax designed by the famous Stanford University professors Robert Hall and Alvin Rabushka. In this context this paper tries to determine which of the existing flat tax systems resemble the true flat tax model by comparing and contrasting their main characteristics with the features of the model proposed by Hall and Rabushka. The research also underlines the common features and the differences between the existing models. The idea of this kind of study is not really new, others have done it but the comparison was limited to one country. For example Emil Kalchev from New Bulgarian University has asses the Bulgarian income system, by comparing it with the flat tax and concluding that taxation in Bulgaria is not simple, neutral and non-distortive. Our research is based on several case studies and on compare and contrast qualitative and quantitative methods. The study starts form the fiscal design drawn by the two American professors in the book The Flat Tax. Four main characteristics of the flat tax system were chosen in order to build the comparison: fiscal design, simplicity, avoidance of double taxation and uniformity of the tax rates. The jurisdictions chosen for the case study are countries all around the globe with fiscal systems which are considered flat tax systems. The results obtained show that the fiscal design of Hong Kong is the only flat tax model which is built following an economic logic and not a legal sense, being in the same time a simple and transparent system. Others countries as Slovakia, Albania, Macedonia in Central and Eastern Europe fulfill the requirement regarding the uniformity of taxation. Other jurisdictions avoid the double

  9. Comparative performance of high-fidelity training models for flexible ureteroscopy: Are all models effective?

    Directory of Open Access Journals (Sweden)

    Shashikant Mishra

    2011-01-01

    Full Text Available Objective: We performed a comparative study of high-fidelity training models for flexible ureteroscopy (URS. Our objective was to determine whether high-fidelity non-virtual reality (VR models are as effective as the VR model in teaching flexible URS skills. Materials and Methods: Twenty-one trained urologists without clinical experience of flexible URS underwent dry lab simulation practice. After a warm-up period of 2 h, tasks were performed on a high-fidelity non-VR (Uro-scopic Trainer TM ; Endo-Urologie-Modell TM and a high-fidelity VR model (URO Mentor TM . The participants were divided equally into three batches with rotation on each of the three stations for 30 min. Performance of the trainees was evaluated by an expert ureteroscopist using pass rating and global rating score (GRS. The participants rated a face validity questionnaire at the end of each session. Results: The GRS improved statistically at evaluation performed after second rotation (P<0.001 for batches 1, 2 and 3. Pass ratings also improved significantly for all training models when the third and first rotations were compared (P<0.05. The batch that was trained on the VR-based model had more improvement on pass ratings on second rotation but could not achieve statistical significance. Most of the realistic domains were higher for a VR model as compared with the non-VR model, except the realism of the flexible endoscope. Conclusions: All the models used for training flexible URS were effective in increasing the GRS and pass ratings irrespective of the VR status.

  10. XCluSim: a visual analytics tool for interactively comparing multiple clustering results of bioinformatics data

    Science.gov (United States)

    2015-01-01

    Background Though cluster analysis has become a routine analytic task for bioinformatics research, it is still arduous for researchers to assess the quality of a clustering result. To select the best clustering method and its parameters for a dataset, researchers have to run multiple clustering algorithms and compare them. However, such a comparison task with multiple clustering results is cognitively demanding and laborious. Results In this paper, we present XCluSim, a visual analytics tool that enables users to interactively compare multiple clustering results based on the Visual Information Seeking Mantra. We build a taxonomy for categorizing existing techniques of clustering results visualization in terms of the Gestalt principles of grouping. Using the taxonomy, we choose the most appropriate interactive visualizations for presenting individual clustering results from different types of clustering algorithms. The efficacy of XCluSim is shown through case studies with a bioinformatician. Conclusions Compared to other relevant tools, XCluSim enables users to compare multiple clustering results in a more scalable manner. Moreover, XCluSim supports diverse clustering algorithms and dedicated visualizations and interactions for different types of clustering results, allowing more effective exploration of details on demand. Through case studies with a bioinformatics researcher, we received positive feedback on the functionalities of XCluSim, including its ability to help identify stably clustered items across multiple clustering results. PMID:26328893

  11. Medaka: a promising model animal for comparative population genomics

    Directory of Open Access Journals (Sweden)

    Watanabe Koji

    2009-05-01

    Full Text Available Abstract Background Within-species genome diversity has been best studied in humans. The international HapMap project has revealed a tremendous amount of single-nucleotide polymorphisms (SNPs among humans, many of which show signals of positive selection during human evolution. In most of the cases, however, functional differences between the alleles remain experimentally unverified due to the inherent difficulty of human genetic studies. It would therefore be highly useful to have a vertebrate model with the following characteristics: (1 high within-species genetic diversity, (2 a variety of gene-manipulation protocols already developed, and (3 a completely sequenced genome. Medaka (Oryzias latipes and its congeneric species, tiny fresh-water teleosts distributed broadly in East and Southeast Asia, meet these criteria. Findings Using Oryzias species from 27 local populations, we conducted a simple screening of nonsynonymous SNPs for 11 genes with apparent orthology between medaka and humans. We found medaka SNPs for which the same sites in human orthologs are known to be highly differentiated among the HapMap populations. Importantly, some of these SNPs show signals of positive selection. Conclusion These results indicate that medaka is a promising model system for comparative population genomics exploring the functional and adaptive significance of allelic differentiations.

  12. Comparing Intrinsic Connectivity Models for the Primary Auditory Cortices

    Science.gov (United States)

    Hamid, Khairiah Abdul; Yusoff, Ahmad Nazlim; Mohamad, Mazlyfarina; Hamid, Aini Ismafairus Abd; Manan, Hanani Abd

    2010-07-01

    This fMRI study is about modeling the intrinsic connectivity between Heschl' gyrus (HG) and superior temporal gyrus (STG) in human primary auditory cortices. Ten healthy male subjects participated and required to listen to white noise stimulus during the fMRI scans. Two intrinsic connectivity models comprising bilateral HG and STG were constructed using statistical parametric mapping (SPM) and dynamic causal modeling (DCM). Group Bayes factor (GBF), positive evidence ratio (PER) and Bayesian model selection (BMS) for group studies were used in model comparison. Group results indicated significant bilateral asymmetrical activation (puncorr < 0.001) in HG and STG. Comparison results showed strong evidence of Model 2 as the preferred model (STG as the input center) with GBF value of 5.77 × 1073 The model is preferred by 6 out of 10 subjects. The results were supported by BMS results for group studies. One-sample t-test on connection values obtained from Model 2 indicates unidirectional parallel connections from STG to bilateral HG (p<0.05). Model 2 was determined to be the most probable intrinsic connectivity model between bilateral HG and STG when listening to white noise.

  13. A comparative review of radiation-induced cancer risk models

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Hee; Kim, Ju Youl [FNC Technology Co., Ltd., Yongin (Korea, Republic of); Han, Seok Jung [Risk and Environmental Safety Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-06-15

    With the need for a domestic level 3 probabilistic safety assessment (PSA), it is essential to develop a Korea-specific code. Health effect assessments study radiation-induced impacts; in particular, long-term health effects are evaluated in terms of cancer risk. The objective of this study was to analyze the latest cancer risk models developed by foreign organizations and to compare the methodology of how they were developed. This paper also provides suggestions regarding the development of Korean cancer risk models. A review of cancer risk models was carried out targeting the latest models: the NUREG model (1993), the BEIR VII model (2006), the UNSCEAR model (2006), the ICRP 103 model (2007), and the U.S. EPA model (2011). The methodology of how each model was developed is explained, and the cancer sites, dose and dose rate effectiveness factor (DDREF) and mathematical models are also described in the sections presenting differences among the models. The NUREG model was developed by assuming that the risk was proportional to the risk coefficient and dose, while the BEIR VII, UNSCEAR, ICRP, and U.S. EPA models were derived from epidemiological data, principally from Japanese atomic bomb survivors. The risk coefficient does not consider individual characteristics, as the values were calculated in terms of population-averaged cancer risk per unit dose. However, the models derived by epidemiological data are a function of sex, exposure age, and attained age of the exposed individual. Moreover, the methodologies can be used to apply the latest epidemiological data. Therefore, methodologies using epidemiological data should be considered first for developing a Korean cancer risk model, and the cancer sites and DDREF should also be determined based on Korea-specific studies. This review can be used as a basis for developing a Korean cancer risk model in the future.

  14. Comparative Paleomagnetic Study of the Quaternary-Pliocene Sedimentation Rates in the Arctic Basin: First Results

    Science.gov (United States)

    Elkina, D.; Piskarev, A.

    2017-12-01

    Accurate dating of marine sediments from the Arctic Basin continues to remain a subject of great debates over the last decades. Due to the lack of adequate materials for biostratigraphy, and isotope analyses, paleomagnetic reconstructions came on line here but still yielded ambivalent interpretations. Moreover, sedimentation rates, estimated for isolated morphological features in the Arctic Ocean, are often extended to the whole Basin and, therefore, lead to significant approximations of the sedimentation pattern distribution. Paleomagnetic study of two sediment cores up to 8 meter long, collected at the Mendeleev Rise, and the Lomonosov Ridge, have provided the opportunity to compare sedimentation regimes on these two profound structures of the Arctic Basin. Cores PS72/396 and PS87/023 were carried out along the cruises of RV Polarstern at the Mendeleev Rise (Stein et. al, 2010), and the Lomonosov Ridge (Stein, 2015) respectively. Measurements of natural remanent magnetization (NRM) and anhysteretic remanence (ARM) acquisition with the following alternating field (AF) demagnetization were performed on u-channel samples, obtained from the cores, at the Center for Geo-Environmental Research and Modeling (GEOMODEL) of the Research Park, St. Petersburg State University. According to preliminary results, core PS72/396 has shown a change from positive to negative inclinations at ca. 120 cm below sea floor (cmbsf), prevailed up to ca. 360 cmbsf where it gets back to the positive ones. This trend is comparable with some previous paleomagnetic results, conducted on cores from the Mendeleev Rise (Piskarev et al., 2013; Elkina, 2014). In contrast, for core PS87/023, a relevant drop to negative inclinations can be observed only after 330 cmbsf. That could signify a dramatic difference in sedimentation rates between the sites during the Quaternary and Pliocene. Nevertheless, a rather complicated picture of the AF data assumes effects of secondary overprints, having influenced

  15. Disaggregation of Rainy Hours: Compared Performance of Various Models.

    Science.gov (United States)

    Ben Haha, M.; Hingray, B.; Musy, A.

    In the urban environment, the response times of catchments are usually short. To de- sign or to diagnose waterworks in that context, it is necessary to describe rainfall events with a good time resolution: a 10mn time step is often necessary. Such in- formation is not always available. Rainfall disaggregation models have thus to be applied to produce from rough rainfall data that short time resolution information. The communication will present the performance obtained with several rainfall dis- aggregation models that allow for the disaggregation of rainy hours into six 10mn rainfall amounts. The ability of the models to reproduce some statistical character- istics of rainfall (mean, variance, overall distribution of 10mn-rainfall amounts; ex- treme values of maximal rainfall amounts over different durations) is evaluated thanks to different graphical and numerical criteria. The performance of simple models pre- sented in some scientific papers or developed in the Hydram laboratory as well as the performance of more sophisticated ones is compared with the performance of the basic constant disaggregation model. The compared models are either deterministic or stochastic; for some of them the disaggregation is based on scaling properties of rainfall. The compared models are in increasing complexity order: constant model, linear model (Ben Haha, 2001), Ormsbee Deterministic model (Ormsbee, 1989), Ar- tificial Neuronal Network based model (Burian et al. 2000), Hydram Stochastic 1 and Hydram Stochastic 2 (Ben Haha, 2001), Multiplicative Cascade based model (Olsson and Berndtsson, 1998), Ormsbee Stochastic model (Ormsbee, 1989). The 625 rainy hours used for that evaluation (with a hourly rainfall amount greater than 5mm) were extracted from the 21 years chronological rainfall series (10mn time step) observed at the Pully meteorological station, Switzerland. The models were also evaluated when applied to different rainfall classes depending on the season first and on the

  16. Comparative evaluation of life cycle assessment models for solid waste management

    International Nuclear Information System (INIS)

    Winkler, Joerg; Bilitewski, Bernd

    2007-01-01

    This publication compares a selection of six different models developed in Europe and America by research organisations, industry associations and governmental institutions. The comparison of the models reveals the variations in the results and the differences in the conclusions of an LCA study done with these models. The models are compared by modelling a specific case - the waste management system of Dresden, Germany - with each model and an in-detail comparison of the life cycle inventory results. Moreover, a life cycle impact assessment shows if the LCA results of each model allows for comparable and consecutive conclusions, which do not contradict the conclusions derived from the other models' results. Furthermore, the influence of different level of detail in the life cycle inventory of the life cycle assessment is demonstrated. The model comparison revealed that the variations in the LCA results calculated by the models for the case show high variations and are not negligible. In some cases the high variations in results lead to contradictory conclusions concerning the environmental performance of the waste management processes. The static, linear modelling approach chosen by all models analysed is inappropriate for reflecting actual conditions. Moreover, it was found that although the models' approach to LCA is comparable on a general level, the level of detail implemented in the software tools is very different

  17. Comparing the staffing models of outsourcing in selected companies

    OpenAIRE

    Chaloupková, Věra

    2010-01-01

    This thesis deals with problems of takeover of employees in outsourcing. The capital purpose is to compare the staffing model of outsourcing in selected companies. To compare in selected companies I chose multi-criteria analysis. This thesis is dividend into six chapters. The first charter is devoted to the theoretical part. In this charter describes the basic concepts as outsourcing, personal aspects, phase of the outsourcing projects, communications and culture. The rest of thesis is devote...

  18. Spinal cord stimulation: modeling results and clinical data

    NARCIS (Netherlands)

    Struijk, Johannes J.; Struijk, J.J.; Holsheimer, J.; Barolat, Giancarlo; He, Jiping

    1992-01-01

    The potential distribution in volume couductor models of the spinal cord at cervical, midthoracic and lowthoracic levels, due to epidural stimulation, was calculated. Treshold stimuli of modeled myelhated dorsal column and dorsal root fibers were calculated and were compared with perception

  19. Comparing i-Tree modeled ozone deposition with field measurements in a periurban Mediterranean forest

    Science.gov (United States)

    A. Morani; D. Nowak; S. Hirabayashi; G. Guidolotti; M. Medori; V. Muzzini; S. Fares; G. Scarascia Mugnozza; C. Calfapietra

    2014-01-01

    Ozone flux estimates from the i-Tree model were compared with ozone flux measurements using the Eddy Covariance technique in a periurban Mediterranean forest near Rome (Castelporziano). For the first time i-Tree model outputs were compared with field measurements in relation to dry deposition estimates. Results showed generally a...

  20. Comparative assessment of PV plant performance models considering climate effects

    DEFF Research Database (Denmark)

    Tina, Giuseppe; Ventura, Cristina; Sera, Dezso

    2017-01-01

    . The methodological approach is based on comparative tests of the analyzed models applied to two PV plants installed respectively in north of Denmark (Aalborg) and in the south of Italy (Agrigento). The different ambient, operating and installation conditions allow to understand how these factors impact the precision...

  1. a comparative study of models for correlated binary data with ...

    African Journals Online (AJOL)

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    significance. Next, several subsets of predictors are compared through the AIC criterion, whenever applicable. Key words/phrases: Beta-binomial, bootstrap, correlated binary data, model selection, overdispersion. *. Current address: University of Hannover, Bioinformatic Unit, Herrenhauser Strasse 2, D-30419 Hannover, ...

  2. A comparative study of models for correlated binary data with ...

    African Journals Online (AJOL)

    Various methods of modeling correlated binary data are compared as applied to data from health services research. The methods include the standard logistic regression, a simple adjustment of the standard errors of logistic regression by a single inflator, the weighted logistic regression, the generalized estimating equation ...

  3. Design of thermolabile bacteriophage repressor mutants by comparative molecular modeling

    NARCIS (Netherlands)

    Nauta, A; vandenBurg, B; Karsens, H; Venema, G; Kok, J; Burg, Bertus van den

    1997-01-01

    Comparative molecular modeling was performed with repressor protein Rro of the temperate Lactococcus lactis bacteriophage r1t using the known 3D-structures of related repressors in order to obtain thermolabile derivatives of Rro. Rro residues presumed to stabilize a nonhomologous but structurally

  4. Conceptualizations of Creativity: Comparing Theories and Models of Giftedness

    Science.gov (United States)

    Miller, Angie L.

    2012-01-01

    This article reviews seven different theories of giftedness that include creativity as a component, comparing and contrasting how each one conceptualizes creativity as a part of giftedness. The functions of creativity vary across the models, suggesting that while the field of gifted education often cites the importance of creativity, the…

  5. Comparative analysis of Vening-Meinesz Moritz isostatic models ...

    Indian Academy of Sciences (India)

    global gravity model and the DTM2006.0 global topographic/bathymetric model are used to generate the isostatic gravity anomalies. The comparison of numerical results reveals that the optimal isostatic inverse scheme should take into consideration both the variable depth and density of compensation. This is achieved by ...

  6. A comparative study of click models for web search

    NARCIS (Netherlands)

    Grotov, A.; Chuklin, A.; Markov, I.; Stout, L.; Xumara, F.; de Rijke, M.; Mothe, J.; Savoy, J.; Kamps, J.; Pinel-Sauvagnat, K.; Jones, G.J.F.; SanJuan, E.; Cappellato, L.; Ferro, N.

    2015-01-01

    Click models have become an essential tool for understanding user behavior on a search engine result page, running simulated experiments and predicting relevance. Dozens of click models have been proposed, all aiming to tackle problems stemming from the complexity of user behavior or of contemporary

  7. Criteria for comparing economic impact models of tourism

    NARCIS (Netherlands)

    Klijs, J.; Heijman, W.J.M.; Korteweg Maris, D.; Bryon, J.

    2012-01-01

    There are substantial differences between models of the economic impacts of tourism. Not only do the nature and precision of results vary, but data demands, complexity and underlying assumptions also differ. Often, it is not clear whether the models chosen are appropriate for the specific situation

  8. Some results regarding the comparison of the Earth's atmospheric models

    Directory of Open Access Journals (Sweden)

    Šegan S.

    2005-01-01

    Full Text Available In this paper we examine air densities derived from our realization of aeronomic atmosphere models based on accelerometer measurements from satellites in a low Earth's orbit (LEO. Using the adapted algorithms we derive comparison parameters. The first results concerning the adjustment of the aeronomic models to the total-density model are given.

  9. A Comparative Study of Neural Networks and Fuzzy Systems in Modeling of a Nonlinear Dynamic System

    Directory of Open Access Journals (Sweden)

    Metin Demirtas

    2011-07-01

    Full Text Available The aim of this paper is to compare the neural networks and fuzzy modeling approaches on a nonlinear system. We have taken Permanent Magnet Brushless Direct Current (PMBDC motor data and have generated models using both approaches. The predictive performance of both methods was compared on the data set for model configurations. The paper describes the results of these tests and discusses the effects of changing model parameters on predictive and practical performance. Modeling sensitivity was used to compare for two methods.

  10. Dermal uptake of phthalates from clothing: Comparison of model to human participant results

    DEFF Research Database (Denmark)

    Morrison, G. C.; Weschler, Charles J.; Beko, G.

    2017-01-01

    In this research, we extend a model of transdermal uptake of phthalates to include a layer of clothing. When compared with experimental results, this model better estimates dermal uptake of diethylphthalate and di-n-butylphthalate (DnBP) than a previous model. The model predictions are consistent...

  11. Comparing interval estimates for small sample ordinal CFA models.

    Science.gov (United States)

    Natesan, Prathiba

    2015-01-01

    Robust maximum likelihood (RML) and asymptotically generalized least squares (AGLS) methods have been recommended for fitting ordinal structural equation models. Studies show that some of these methods underestimate standard errors. However, these studies have not investigated the coverage and bias of interval estimates. An estimate with a reasonable standard error could still be severely biased. This can only be known by systematically investigating the interval estimates. The present study compares Bayesian, RML, and AGLS interval estimates of factor correlations in ordinal confirmatory factor analysis models (CFA) for small sample data. Six sample sizes, 3 factor correlations, and 2 factor score distributions (multivariate normal and multivariate mildly skewed) were studied. Two Bayesian prior specifications, informative and relatively less informative were studied. Undercoverage of confidence intervals and underestimation of standard errors was common in non-Bayesian methods. Underestimated standard errors may lead to inflated Type-I error rates. Non-Bayesian intervals were more positive biased than negatively biased, that is, most intervals that did not contain the true value were greater than the true value. Some non-Bayesian methods had non-converging and inadmissible solutions for small samples and non-normal data. Bayesian empirical standard error estimates for informative and relatively less informative priors were closer to the average standard errors of the estimates. The coverage of Bayesian credibility intervals was closer to what was expected with overcoverage in a few cases. Although some Bayesian credibility intervals were wider, they reflected the nature of statistical uncertainty that comes with the data (e.g., small sample). Bayesian point estimates were also more accurate than non-Bayesian estimates. The results illustrate the importance of analyzing coverage and bias of interval estimates, and how ignoring interval estimates can be misleading

  12. Impact Flash Physics: Modeling and Comparisons With Experimental Results

    Science.gov (United States)

    Rainey, E.; Stickle, A. M.; Ernst, C. M.; Schultz, P. H.; Mehta, N. L.; Brown, R. C.; Swaminathan, P. K.; Michaelis, C. H.; Erlandson, R. E.

    2015-12-01

    Hypervelocity impacts frequently generate an observable "flash" of light with two components: a short-duration spike due to emissions from vaporized material, and a long-duration peak due to thermal emissions from expanding hot debris. The intensity and duration of these peaks depend on the impact velocity, angle, and the target and projectile mass and composition. Thus remote sensing measurements of planetary impact flashes have the potential to constrain the properties of impacting meteors and improve our understanding of impact flux and cratering processes. Interpreting impact flash measurements requires a thorough understanding of how flash characteristics correlate with impact conditions. Because planetary-scale impacts cannot be replicated in the laboratory, numerical simulations are needed to provide this insight for the solar system. Computational hydrocodes can produce detailed simulations of the impact process, but they lack the radiation physics required to model the optical flash. The Johns Hopkins University Applied Physics Laboratory (APL) developed a model to calculate the optical signature from the hot debris cloud produced by an impact. While the phenomenology of the optical signature is understood, the details required to accurately model it are complicated by uncertainties in material and optical properties and the simplifications required to numerically model radiation from large-scale impacts. Comparisons with laboratory impact experiments allow us to validate our approach and to draw insight regarding processes that occur at all scales in impact events, such as melt generation. We used Sandia National Lab's CTH shock physics hydrocode along with the optical signature model developed at APL to compare with a series of laboratory experiments conducted at the NASA Ames Vertical Gun Range. The experiments used Pyrex projectiles to impact pumice powder targets with velocities ranging from 1 to 6 km/s at angles of 30 and 90 degrees with respect to

  13. Verification of aseismic design model by using experimental results

    International Nuclear Information System (INIS)

    Mizuno, N.; Sugiyama, N.; Suzuki, T.; Shibata, Y.; Miura, K.; Miyagawa, N.

    1985-01-01

    A lattice model is applied as an analysis model for an aseismic design of the Hamaoka nuclear reactor building. With object to verify an availability of this design model, two reinforced concrete blocks are constructed on the ground and the forced vibration tests are carried out. The test results are well followed by simulation analysis using the lattice model. Damping value of the ground obtained from the test is more conservative than the design value. (orig.)

  14. Mathematical modelling of human growth: A comparative study.

    Science.gov (United States)

    Guo, Shumei; Siervogel, Roger M; Roche, Alex F; Chumlea, Wm Cameron

    1992-01-01

    Kernel regression is a nonparametric procedure that provides good approximations to individual serial data. The method is useful and flexible when a parametric method is inappropriate due to restricted assumptions on the shape of the curve. In the present study, we compared kernel regression in fitting human stature growth with two models, one of which incorporates the possible existence of the midgrowth spurt while the other does not. Two families of mathematical functions and a nonparametric kernel regression were fitted to serial measures of stature on 227 participants enrolled in the Fels Longitudinal Study. The growth parameters that describe the timing, magnitude, and duration of the growth spurt, such as midgrowth spurt and pubertal spurts, were derived from the fitted models and kernel regression for each participant. The two parametric models and kernel regression were compared in regard to their overall goodness of fit and their capabilities to quantify the timing, rate of increase, and duration of the growth events. The Preece-Baines model does not describe the midgrowth spurt. The dervied growth parameters from the Preece-Baines model show an earlier onset and a longer duration of the pubertal spurt, and a slower increase in velocity. The kernel regression with bandwidth 2 years and a second-order polynomial kernel function yields relatively good fits compared with the triple logistic model. The derived biological parameters for the pubertal spurt are similar between the kernel regression and the triple logistic model. Kernel regression estimates an earlier onset and a more rapid increase of velocity for the midgrowth spurt. Copyright © 1992 Wiley-Liss, Inc., A Wiley Company.

  15. The Estimation of Knowledge Solidity Based on the Comparative Analysis of Different Test Results

    Directory of Open Access Journals (Sweden)

    Y. K. Khenner

    2012-01-01

    Full Text Available At present, the testing techniques of knowledge estimation are widely spread in educational system. However, this method is seriously criticized including its application to the Unified State Examinations. The research is aimed at studying the limitations of testing techniques. The authors recommend a new way of knowledge solid- ity estimation bases on the comparative results analysis of various kinds of tests. While testing the large group of students, the authors found out that the results of the closed and open tests substantially differ. The comparative analysis demonstrates that the open tests assessment of the knowledge solidity is more adequate than that of the closed ones. As the research is only based on a single experiment, the authors recommend using this method further, substantiating the findings concerning the differences in tests results, and analyzing the advantages and disadvantages of the tests in question. 

  16. River suspended sediment modelling using the CART model: A comparative study of machine learning techniques.

    Science.gov (United States)

    Choubin, Bahram; Darabi, Hamid; Rahmati, Omid; Sajedi-Hosseini, Farzaneh; Kløve, Bjørn

    2018-02-15

    Suspended sediment load (SSL) modelling is an important issue in integrated environmental and water resources management, as sediment affects water quality and aquatic habitats. Although classification and regression tree (CART) algorithms have been applied successfully to ecological and geomorphological modelling, their applicability to SSL estimation in rivers has not yet been investigated. In this study, we evaluated use of a CART model to estimate SSL based on hydro-meteorological data. We also compared the accuracy of the CART model with that of the four most commonly used models for time series modelling of SSL, i.e. adaptive neuro-fuzzy inference system (ANFIS), multi-layer perceptron (MLP) neural network and two kernels of support vector machines (RBF-SVM and P-SVM). The models were calibrated using river discharge, stage, rainfall and monthly SSL data for the Kareh-Sang River gauging station in the Haraz watershed in northern Iran, where sediment transport is a considerable issue. In addition, different combinations of input data with various time lags were explored to estimate SSL. The best input combination was identified through trial and error, percent bias (PBIAS), Taylor diagrams and violin plots for each model. For evaluating the capability of the models, different statistics such as Nash-Sutcliffe efficiency (NSE), Kling-Gupta efficiency (KGE) and percent bias (PBIAS) were used. The results showed that the CART model performed best in predicting SSL (NSE=0.77, KGE=0.8, PBIAS<±15), followed by RBF-SVM (NSE=0.68, KGE=0.72, PBIAS<±15). Thus the CART model can be a helpful tool in basins where hydro-meteorological data are readily available. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Water calorimetry with thermistor bridge operated in DC and AC mode: comparative results

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, A.S.; Laitano, R.F.; Petrocchi, A. [Ist. Nazionale di Metrologia delle Radiazioni Ionizzanti, ENEA, Roma (Italy)

    1997-09-01

    An experimental study was carried out to find out the optimal conditions for measuring the output signal in a water calorimeter. To this end the thermistor bridge of the calorimeter was operated in AC and in DC mode, respectively. A comparative analysis of these two alternative methods was the made. In the AC mode measurement a lock-in amplifier based experimental assembly was used and compared to the more conventional system based on a high-sensitivty DC amplifier. The AC system resulted to be preferable as far as the short term and long term reproducibility is concerned. (orig.)

  18. Comparison of blade-strike modeling results with empirical data

    Energy Technology Data Exchange (ETDEWEB)

    Ploskey, Gene R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carlson, Thomas J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2004-03-01

    This study is the initial stage of further investigation into the dynamics of injury to fish during passage through a turbine runner. As part of the study, Pacific Northwest National Laboratory (PNNL) estimated the probability of blade strike, and associated injury, as a function of fish length and turbine operating geometry at two adjacent turbines in Powerhouse 1 of Bonneville Dam. Units 5 and 6 had identical intakes, stay vanes, wicket gates, and draft tubes, but Unit 6 had a new runner and curved discharge ring to minimize gaps between the runner hub and blades and between the blade tips and discharge ring. We used a mathematical model to predict blade strike associated with two Kaplan turbines and compared results with empirical data from biological tests conducted in 1999 and 2000. Blade-strike models take into consideration the geometry of the turbine blades and discharges as well as fish length, orientation, and distribution along the runner. The first phase of this study included a sensitivity analysis to consider the effects of difference in geometry and operations between families of turbines on the strike probability response surface. The analysis revealed that the orientation of fish relative to the leading edge of a runner blade and the location that fish pass along the blade between the hub and blade tip are critical uncertainties in blade-strike models. Over a range of discharges, the average prediction of injury from blade strike was two to five times higher than average empirical estimates of visible injury from shear and mechanical devices. Empirical estimates of mortality may be better metrics for comparison to predicted injury rates than other injury measures for fish passing at mid-blade and blade-tip locations.

  19. Steel Containment Vessel Model Test: Results and Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Costello, J.F.; Hashimote, T.; Hessheimer, M.F.; Luk, V.K.

    1999-03-01

    A high pressure test of the steel containment vessel (SCV) model was conducted on December 11-12, 1996 at Sandia National Laboratories, Albuquerque, NM, USA. The test model is a mixed-scaled model (1:10 in geometry and 1:4 in shell thickness) of an improved Mark II boiling water reactor (BWR) containment. A concentric steel contact structure (CS), installed over the SCV model and separated at a nominally uniform distance from it, provided a simplified representation of a reactor shield building in the actual plant. The SCV model and contact structure were instrumented with strain gages and displacement transducers to record the deformation behavior of the SCV model during the high pressure test. This paper summarizes the conduct and the results of the high pressure test and discusses the posttest metallurgical evaluation results on specimens removed from the SCV model.

  20. Results from the coupled Michigan MHD model and the Rice Convection Model

    Science.gov (United States)

    de Zeeuw, D.; Sazykin, S.; Wolf, R.; Gombosi, T.; Powell, K.

    A new high performance Rice Convection Model (RCM) has been coupled to the adaptive-grid Michigan MHD model (BATSRUS). This fully coupled code allows us to self-consistently simulate the physics in the inner and middle magnetosphere. A study will be presented of the basic characteristics of the inner and middle magnetosphere in the context of a single coupled-code run with steady inputs. The analysis will include region-2 currents, shielding of the inner magnetosphere, partial ring currents, pressure distribution, magnetic field inflation, and distribution of pV^gamma. The coupled-code simulation will be compared with results from RCM runs and algorithms.

  1. Identifiability Results for Several Classes of Linear Compartment Models.

    Science.gov (United States)

    Meshkat, Nicolette; Sullivant, Seth; Eisenberg, Marisa

    2015-08-01

    Identifiability concerns finding which unknown parameters of a model can be estimated, uniquely or otherwise, from given input-output data. If some subset of the parameters of a model cannot be determined given input-output data, then we say the model is unidentifiable. In this work, we study linear compartment models, which are a class of biological models commonly used in pharmacokinetics, physiology, and ecology. In past work, we used commutative algebra and graph theory to identify a class of linear compartment models that we call identifiable cycle models, which are unidentifiable but have the simplest possible identifiable functions (so-called monomial cycles). Here we show how to modify identifiable cycle models by adding inputs, adding outputs, or removing leaks, in such a way that we obtain an identifiable model. We also prove a constructive result on how to combine identifiable models, each corresponding to strongly connected graphs, into a larger identifiable model. We apply these theoretical results to several real-world biological models from physiology, cell biology, and ecology.

  2. Comparative modeling of InP solar cell structures

    Science.gov (United States)

    Jain, R. K.; Weinberg, I.; Flood, D. J.

    1991-01-01

    The comparative modeling of p(+)n and n(+)p indium phosphide solar cell structures is studied using a numerical program PC-1D. The optimal design study has predicted that the p(+)n structure offers improved cell efficiencies as compared to n(+)p structure, due to higher open-circuit voltage. The various cell material and process parameters to achieve the maximum cell efficiencies are reported. The effect of some of the cell parameters on InP cell I-V characteristics was studied. The available radiation resistance data on n(+)p and p(+)p InP solar cells are also critically discussed.

  3. 3D Conformal radiotherapy for gastric cancer-results of a comparative planning study

    International Nuclear Information System (INIS)

    Leong, Trevor; Willis, David; Joon, Daryl Lim; Condron, Sara; Hui, Andrew; Ngan, Samuel Y.K.

    2005-01-01

    Background and purpose: Many radiation oncologists are reluctant to use anteroposterior-posteroanterior (AP-PA) field arrangements when treating gastric cancer with adjuvant postoperative radiotherapy due to concerns about normal tissue toxicity, particularly in relation to the kidneys and spinal cord. In this report, we describe a multiple-field conformal radiotherapy technique, and compare this technique to the more commonly used AP-PA technique that was used in the recently reported Intergroup study (INT0116). Materials and methods: Fifteen patients with stages II-IV adenocarcinoma of the stomach were treated with adjuvant postoperative chemoradiotherapy using a standardised 3D conformal radiotherapy technique that consisted of a 'split-field', mono-isocentric arrangement employing 6 radiation fields. For each patient, a second radiotherapy treatment plan was generated utilising AP-PA fields. The two techniques were then compared for target volume coverage and dose to normal tissues using dose volume histogram (DVH) analysis. Results: The conformal technique provides more adequate coverage of the target volume with 99% of the planning target volume (PTV) receiving 95% of the prescribed dose, compared to 93% using AP-PA fields. Comparative DVHs for the right kidney, left kidney and spinal cord demonstrate lower radiation doses using the conformal technique, and although the liver dose is higher, it is still well below liver tolerance. Conclusions: 3D conformal radiotherapy produces superior dose distributions and reduced radiation doses to the kidneys and spinal cord compared to AP-PA techniques, with the potential to reduce treatment toxicity

  4. Comparing the Floating Point Systems, Inc. AP-190L to representative scientific computers: some benchmark results

    International Nuclear Information System (INIS)

    Brengle, T.A.; Maron, N.

    1980-01-01

    Results are presented of comparative timing tests made by running a typical FORTRAN physics simulation code on the following machines: DEC PDP-10 with KI processor; DEC PDP-10, KI processor, and FPS AP-190L; CDC 7600; and CRAY-1. Factors such as DMA overhead, code size for the AP-190L, and the relative utilization of floating point functional units for the different machines are discussed. 1 table

  5. Results of the Marine Ice Sheet Model Intercomparison Project, MISMIP

    Directory of Open Access Journals (Sweden)

    F. Pattyn

    2012-05-01

    Full Text Available Predictions of marine ice-sheet behaviour require models that are able to robustly simulate grounding line migration. We present results of an intercomparison exercise for marine ice-sheet models. Verification is effected by comparison with approximate analytical solutions for flux across the grounding line using simplified geometrical configurations (no lateral variations, no effects of lateral buttressing. Unique steady state grounding line positions exist for ice sheets on a downward sloping bed, while hysteresis occurs across an overdeepened bed, and stable steady state grounding line positions only occur on the downward-sloping sections. Models based on the shallow ice approximation, which does not resolve extensional stresses, do not reproduce the approximate analytical results unless appropriate parameterizations for ice flux are imposed at the grounding line. For extensional-stress resolving "shelfy stream" models, differences between model results were mainly due to the choice of spatial discretization. Moving grid methods were found to be the most accurate at capturing grounding line evolution, since they track the grounding line explicitly. Adaptive mesh refinement can further improve accuracy, including fixed grid models that generally perform poorly at coarse resolution. Fixed grid models, with nested grid representations of the grounding line, are able to generate accurate steady state positions, but can be inaccurate over transients. Only one full-Stokes model was included in the intercomparison, and consequently the accuracy of shelfy stream models as approximations of full-Stokes models remains to be determined in detail, especially during transients.

  6. Integrating coalescent and ecological niche modeling in comparative phylogeography.

    Science.gov (United States)

    Carstens, Bryan C; Richards, Corinne L

    2007-06-01

    Understanding the factors that contribute to the formation of population genetic structure is a central goal of phylogeographic research, but achieving this goal can be complicated by the stochastic variance inherent to genetic processes. Statistical approaches to testing phylogeographic hypotheses accommodate this stochasticity by evaluating competing models of putative historical population structure, often by simulating null distributions of the expected variance. The effectiveness of these tests depends on the biological realism of the models. Information from the fossil record can aid in reconstructing the historical distributions of some taxa. However, for the majority of taxa, which lack sufficient fossils, paleodistributional modeling can provide valuable spatial-geographic data concerning ancestral distributions. Paleodistributional models are generated by projecting ecological niche models, which predict the current distribution of each species, onto a model of past climatic conditions. Here, we generate paleodistributional models describing the suitable habitat during the last glacial maximum for lineages from the mesic forests of the Pacific Northwest of North America, and use these models to generate alternative phylogeographic hypotheses. Coalescent simulations are then used to test these hypotheses to improve our understanding of the historical events that promoted the formation of population genetic structure in this ecosystem. Results from Pacific Northwest mesic forest organisms demonstrate the utility of these combined approaches. Paleodistribution models and population genetic structure are congruent across three amphibian lineages, suggesting that they have responded in a concerted manner to environmental change. Two other species, a willow and a water vole, despite being currently codistributed and having similar population genetic structure, were predicted by the paleodistributional model to have had markedly different distributions during

  7. Social inclusion of the people with mental health issues: Compare international results.

    Science.gov (United States)

    Santos, Jussara Carvalho Dos; Barros, Sônia; Huxley, Peter John

    2018-03-01

    Social inclusion of people with mental health issues is an aim of the World Health Organisation. Many countries have adopted that objective, including Brazil and the United Kingdom and both have focused treatment in the community. The aim of this article is to compare international results using the same inclusion instrument. The samples in this study were 225 people with mental health issues in community services in São Paulo, Brazil. Their results are compared to findings from 168 people with similar mental health issues in Hong Kong, China, and from the United Kingdom - a nationally representative sample of 212 people without mental health issues. The instrument used to measure a social inclusion called Social and Communities Opportunities Profile (SCOPE) has been validated for use in the United Kingdom, China and Brazil. The results are that people with mental health issues have worse social inclusion when compared to general population. Between the people with mental health issues, the sample of São Paulo has the lowest social inclusion index but, in relation to access to the Brazilian revised mental health services, that sample has a similarly high inclusion rating to the general population of the United Kingdom. Findings are important to understand mental health in the community context, as well as their adversities and potentialities.

  8. Comparing Neural Networks and ARMA Models in Artificial Stock Market

    Czech Academy of Sciences Publication Activity Database

    Krtek, Jiří; Vošvrda, Miloslav

    2011-01-01

    Roč. 18, č. 28 (2011), s. 53-65 ISSN 1212-074X R&D Projects: GA ČR GD402/09/H045 Institutional research plan: CEZ:AV0Z10750506 Keywords : neural networks * vector ARMA * artificial market Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2011/E/krtek-comparing neural networks and arma models in artificial stock market.pdf

  9. Results on the symmetries of integrable fermionic models on chains

    International Nuclear Information System (INIS)

    Dolcini, F.; Montorsi, A.

    2001-01-01

    We investigate integrable fermionic models within the scheme of the graded quantum inverse scattering method, and prove that any symmetry imposed on the solution of the Yang-Baxter equation reflects on the constants of motion of the model; generalizations with respect to known results are discussed. This theorem is shown to be very effective when combined with the polynomial R-matrix technique (PRT): we apply both of them to the study of the extended Hubbard models, for which we find all the subcases enjoying several kinds of (super)symmetries. In particular, we derive a geometrical construction expressing any gl(2,1)-invariant model as a linear combination of EKS and U-supersymmetric models. Further, we use the PRT to obtain 32 integrable so(4)-invariant models. By joint use of the Sutherland's species technique and η-pairs construction we propose a general method to derive their physical features, and we provide some explicit results

  10. Births resulting from assisted reproductive technology: comparing birth certificate and National ART Surveillance System Data, 2011.

    Science.gov (United States)

    Thoma, Marie E; Boulet, Sheree; Martin, Joyce A; Kissin, Dmitry

    2014-12-10

    This report compares data on births resulting from assisted reproductive technology (ART) procedures from 2011 birth certificates with data from the 2011 National ART Surveillance System (NASS) among the subset of jurisdictions that adopted the 2003 revised birth certificate as of January 1, 2011, with information on ART. Birth certificate data are based on 100% of births registered in 27 states and the District of Columbia. NASS data included all ART cycles initiated in 2010 or 2011 for which a live birth in 2011 was reported. The same reporting area was used for both data sources and represents 67% of all births in the United States in 2011. A ratio was computed by dividing the percentage of births resulting from ART procedures for NASS data by the percentage for birth certificate data. A ratio of 1.0 represents equivalent levels of reporting. Because this reporting area is not a random sample of births, the results are not generalizable to the United States as a whole. Overall, the percentage of births resulting from ART procedures was 2.06 times higher for NASS data (1.44%) compared with birth certificate data (0.70%). The ratio for each jurisdiction varied from 1.04 for Utah and Wisconsin to 7.50 for Florida. Higher-risk groups had more consistent reporting. between data sources [e.g., triplet or higher-order multiples (1.36) compared with singletons (2.11)]. Births resulting from ART procedures appear to be underreported on the birth certificate; however, the magnitude of underreporting varied by jurisdiction and maternal-infant health characteristics.

  11. Delta-tilde interpretation of standard linear mixed model results

    DEFF Research Database (Denmark)

    Brockhoff, Per Bruun; Amorim, Isabel de Sousa; Kuznetsova, Alexandra

    2016-01-01

    data set and compared to actual d-prime calculations based on Thurstonian regression modeling through the ordinal package. For more challenging cases we offer a generic "plug-in" implementation of a version of the method as part of the R-package SensMixed. We discuss and clarify the bias mechanisms...

  12. Estimating, Testing, and Comparing Specific Effects in Structural Equation Models: The Phantom Model Approach

    Science.gov (United States)

    Macho, Siegfried; Ledermann, Thomas

    2011-01-01

    The phantom model approach for estimating, testing, and comparing specific effects within structural equation models (SEMs) is presented. The rationale underlying this novel method consists in representing the specific effect to be assessed as a total effect within a separate latent variable model, the phantom model that is added to the main…

  13. Comparative analysis of INTOR-like designs: Status and preliminary results

    International Nuclear Information System (INIS)

    Flanagan, C.A.; Galambos, J.D.; Peng, P.K.M.; Reid, R.L.; Strickler, D.J.

    1987-07-01

    This document provides an interim status report on the INTOR tasks related to the critical analysis of INTOR-like designs. At the INTOR Workshop in December 1986, and updated at the INTOR related Specialists' Meeting in March 1987, a series of comparative analysis studies was established. Initial results were targeted for completion for the July INTOR meeting and final results completed for the November INTOR meeting. The goal of the analytic comparisons is to evaluate and determine the specific impact of how different choices affect the design. The results of such an analytic determination should allow the international community to identify and agree upon which aspects of choice have what influence on the International Thermonuclear Experimental Reactor (ITER) design

  14. Multiple sclerosis risk sharing scheme: two year results of clinical cohort study with historical comparator.

    Science.gov (United States)

    Boggild, Mike; Palace, Jackie; Barton, Pelham; Ben-Shlomo, Yoav; Bregenzer, Thomas; Dobson, Charles; Gray, Richard

    2009-12-02

    To generate evidence on the longer term cost effectiveness of disease modifying treatments in patients with relapsing-remitting multiple sclerosis. Prospective cohort study with historical comparator. Specialist multiple sclerosis clinics in 70 centres in the United Kingdom. Patients with relapsing-remitting multiple sclerosis who started treatment from May 2002 to April 2005 under the UK risk sharing scheme. Treatment with interferon beta or glatiramer acetate in accordance with guidelines of the UK Association of British Neurologists. Observed utility weighted progression in disability at two years' follow-up assessed on the expanded disability status scale (EDSS) compared with that expected by applying the progression rates in a comparator dataset, modified for patients receiving treatment by multiplying by the hazard ratio derived separately for each disease modifying treatment from the randomised trials. In the primary per protocol analysis, progression in disability was worse than that predicted and worse than that in the untreated comparator dataset ("deviation score" of 113%; excess in mean disability status scale 0.28). In sensitivity analyses, however, the deviation score varied from -72% (using raw baseline disability status scale scores, rather than applying a "no improvement" algorithm) to 156% (imputing missing data for year two from progression rates for year one). It is too early to reach any conclusion about the cost effectiveness of disease modifying treatments from this first interim analysis. Important methodological issues, including the need for additional comparator datasets, the potential bias from missing data, and the impact of the "no improvement" rule, will need to be addressed and long term follow-up of all patients is essential to secure meaningful results. Future analyses of the cohort are likely to be more informative, not least because they will be less sensitive to short term fluctuations in disability.

  15. Atterberg Limits Prediction Comparing SVM with ANFIS Model

    Directory of Open Access Journals (Sweden)

    Mohammad Murtaza Sherzoy

    2017-03-01

    Full Text Available Support Vector Machine (SVM and Adaptive Neuro-Fuzzy inference Systems (ANFIS both analytical methods are used to predict the values of Atterberg limits, such as the liquid limit, plastic limit and plasticity index. The main objective of this study is to make a comparison between both forecasts (SVM & ANFIS methods. All data of 54 soil samples are used and taken from the area of Peninsular Malaysian and tested for different parameters containing liquid limit, plastic limit, plasticity index and grain size distribution and were. The input parameter used in for this case are the fraction of grain size distribution which are the percentage of silt, clay and sand. The actual and predicted values of Atterberg limit which obtained from the SVM and ANFIS models are compared by using the correlation coefficient R2 and root mean squared error (RMSE value.  The outcome of the study show that the ANFIS model shows higher accuracy than SVM model for the liquid limit (R2 = 0.987, plastic limit (R2 = 0.949 and plastic index (R2 = 0966. RMSE value that obtained for both methods have shown that the ANFIS model has represent the best performance than SVM model to predict the Atterberg Limits as a whole.

  16. COMPARATIVE STUDY ON MAIN SOLVENCY ASSESSMENT MODELS FOR INSURANCE FIELD

    Directory of Open Access Journals (Sweden)

    Daniela Nicoleta SAHLIAN

    2015-07-01

    Full Text Available During the recent financial crisis of insurance domain, there were imposed new aspects that have to be taken into account concerning the risks management and surveillance activity. The insurance societies could develop internal models in order to determine the minimum capital requirement imposed by the new regulations that are to be adopted on 1 January 2016. In this respect, the purpose of this research paper is to offer a real presentation and comparing with the main solvency regulation systems used worldwide, the accent being on their common characteristics and current tendencies. Thereby, we would like to offer a better understanding of the similarities and differences between the existent solvency regimes in order to develop the best regime of solvency for Romania within the Solvency II project. The study will show that there are clear differences between the existent Solvency I regime and the new approaches based on risk and will also point out the fact that even the key principles supporting the new solvency regimes are convergent, there are a lot of approaches for the application of these principles. In this context, the question we would try to find the answer is "how could the global solvency models be useful for the financial surveillance authority of Romania for the implementation of general model and for the development of internal solvency models according to the requirements of Solvency II" and "which would be the requirements for the implementation of this type of approach?". This thing makes the analysis of solvency models an interesting exercise.

  17. Comparing droplet activation parameterisations against adiabatic parcel models using a novel inverse modelling framework

    Science.gov (United States)

    Partridge, Daniel; Morales, Ricardo; Stier, Philip

    2015-04-01

    Many previous studies have compared droplet activation parameterisations against adiabatic parcel models (e.g. Ghan et al., 2001). However, these have often involved comparisons for a limited number of parameter combinations based upon certain aerosol regimes. Recent studies (Morales et al., 2014) have used wider ranges when evaluating their parameterisations, however, no study has explored the full possible multi-dimensional parameter space that would be experienced by droplet activations within a global climate model (GCM). It is important to be able to efficiently highlight regions of the entire multi-dimensional parameter space in which we can expect the largest discrepancy between parameterisation and cloud parcel models in order to ascertain which regions simulated by a GCM can be expected to be a less accurate representation of the process of cloud droplet activation. This study provides a new, efficient, inverse modelling framework for comparing droplet activation parameterisations to more complex cloud parcel models. To achieve this we couple a Markov Chain Monte Carlo algorithm (Partridge et al., 2012) to two independent adiabatic cloud parcel models and four droplet activation parameterisations. This framework is computationally faster than employing a brute force Monte Carlo simulation, and allows us to transparently highlight which parameterisation provides the closest representation across all aerosol physiochemical and meteorological environments. The parameterisations are demonstrated to perform well for a large proportion of possible parameter combinations, however, for certain key parameters; most notably the vertical velocity and accumulation mode aerosol concentration, large discrepancies are highlighted. These discrepancies correspond for parameter combinations that result in very high/low simulated values of maximum supersaturation. By identifying parameter interactions or regimes within the multi-dimensional parameter space we hope to guide

  18. Channel Verification Results for the SCME models in a Multi-Probe Based MIMO OTA Setup

    DEFF Research Database (Denmark)

    Fan, Wei; Carreño, Xavier; S. Ashta, Jagjit

    2013-01-01

    , where the focus is on comparing results from various proposed methods. Channel model verification is necessary to ensure that the target channel models are correctly implemented inside the test area. This paper shows that the all the key parameters of the SCME models, i.e., power delay profile, temporal...

  19. A comparative study of independent particle model based ...

    Indian Academy of Sciences (India)

    We find that among these three independent particle model based methods, the ss-VSCF method provides most accurate results in the thermal averages followed by t-SCF and the v-VSCF is the least accurate. However, the ss-VSCF is found to be computationally very expensive for the large molecules. The t-SCF gives ...

  20. Applying fuzzy logic to comparative distribution modelling: a case study with two sympatric amphibians.

    Science.gov (United States)

    Barbosa, A Márcia; Real, Raimundo

    2012-01-01

    We modelled the distributions of two toads (Bufo bufo and Epidalea calamita) in the Iberian Peninsula using the favourability function, which makes predictions directly comparable for different species and allows fuzzy logic operations to relate different models. The fuzzy intersection between individual models, representing favourability for the presence of both species simultaneously, was compared with another favourability model built on the presences shared by both species. The fuzzy union between individual models, representing favourability for the presence of any of the two species, was compared with another favourability model based on the presences of either or both of them. The fuzzy intersections between favourability for each species and the complementary of favourability for the other (corresponding to the logical operation "A and not B") were compared with models of exclusive presence of one species versus the exclusive presence of the other. The results of modelling combined species data were highly similar to those of fuzzy logic operations between individual models, proving fuzzy logic and the favourability function valuable for comparative distribution modelling. We highlight several advantages of fuzzy logic over other forms of combining distribution models, including the possibility to combine multiple species models for management and conservation planning.

  1. Comparative Analysis of Different Measurement Techniques for MLC Characterization: Preliminary Results

    International Nuclear Information System (INIS)

    Larraga-Gutierrez, J. M.; Ballesteros-Zebadua, P.; Garcia-Garduno, O. A.; Martinez-Davalos, A.; Rodriguez-Villafuerte, M.; Moreno-Jimenez, S.; Celis, M. A.

    2008-01-01

    Radiation transmission, leakage and beam penumbra are essential dosimetric parameters related to the commissioning of a multileaf collimation system. This work shows a comparative analysis of commonly used film detectors: X-OMAT V2 and EDR2 radiographic films, and GafChromic EBT registered radiochromic film. The results show that X-OMAT over-estimates radiation leakage and 80-20% beam penumbra. However, according to the reference values reported by the manufacturer for these dosimetric parameters, all three films are adequate for MLC dosimetric characterization, but special care must be taken when X-OMAT V2 film is used due to its low energy photon dependence

  2. Comparing Papanicolaou test results obtained during pregnancy and post-partum.

    Science.gov (United States)

    Suzuki, Kazuhiro; Furuhashi, Madoka; Kawamura, Takuya; Kubo, Michiko; Osato, Kazuhiro; Yamawaki, Takaharu

    2017-04-01

    Cervical cancer onset initially occurs during youth. Papanicolaou tests performed in early pregnancy can detect cervical cancer; however, Papanicolaou tests during pregnancy have been noted to be inaccurate, reflecting changes associated with pregnancy. Therefore, we assessed the effect of pregnancy on Papanicolaou test results. Of 1351 pregnant women who delivered at Ise Red Cross Hospital between January 2010 and December 2014, 1213 underwent Papanicolaou tests at early pregnancy and post-partum. We compared the Papanicolaou test results. The results of the Papanicolaou test were different in 32 patients. Of the 1191 patients negative for intraepithelial lesions or malignancy in early pregnancy, 16 had other cytological abnormalities post-partum. We performed therapeutic conization post-partum in four patients. The Papanicolaou test results in early pregnancy of the four patients were negative for intraepithelial lesions or malignancy in one patient, atypical squamous cells of undetermined significance in one and high-grade squamous intraepithelial lesion in two. The results of the Papanicolaou test during pregnancy may not be accurate because of the influence of hormones associated with pregnancy. Taking advantage of the one-month post-partum screening visit can lead to early detection and treatment of cervical cancer in young people. © 2017 Japan Society of Obstetrics and Gynecology.

  3. Comparing online and telephone survey results in the context of a skin cancer prevention campaign evaluation.

    Science.gov (United States)

    Hollier, L P; Pettigrew, S; Slevin, T; Strickland, M; Minto, C

    2017-03-01

    A large proportion of health promotion campaign evaluation research has historically been conducted via telephone surveys. However, there are concerns about the continued viability of this form of surveying in providing relevant and representative data. Online surveys are an increasingly popular alternative, and as such there is a need to assess the comparability between data collected using the two different methods to determine the implications for longitudinal comparisons. The present study compared these survey modes in the context of health promotion evaluation research. Data were collected via computer-assisted telephone interviewing and an online panel. In total, 688 and 606 respondents aged between 14 and 45 years completed the online and telephone surveys, respectively. Online respondents demonstrated higher awareness of the advertisement, rated the advertisement as more personally relevant and had better behavioural outcomes compared with the telephone respondents. The results indicate significant differences between the telephone and online surveys on most measures used to assess the effectiveness of a health promotion advertising campaign. Health promotion practitioners could consider the combination of both methods to overcome the deterioration in telephone survey response rates and the likely differences in respondent outcomes. © The Author 2016. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Clinical results in carcinoma of the cervix: radium compared to caesium using remote afterloading

    International Nuclear Information System (INIS)

    Jackson, S.M.; Fairey, R.N.; Kornelsen, R.O.; Young, M.E.J.; Wong, F.L.

    1989-01-01

    In 1979 the Cancer Control Agency of British Columbia changed from radium to remote controlled afterloaded caesium in the treatment of carcinoma of the cervix. In 3 years prior to the change, 139 patients received radium as part of their treatment and in the 3 years after the change, 158 patients received caesium. Overall referral patterns, patient and cancer demographics, and treatment policies were stable throughout the 6-year period. Radiotherapy technique, dose, dose distribution and dose rate were comparable for both radium and caesium treated patients. The results of treatment in the two time periods showed no difference in survival, local tumour control or complications. The use of afterloading has not compromised treatment results and has allowed better nursing care for patients and protection from radiation for all staff. (author)

  5. Laboratory compaction test methods and results compared with attainable field densities on subbase materials

    International Nuclear Information System (INIS)

    Hoffman, G.L.; Cumberledge, G.; Koehler, W.C.

    1976-01-01

    With the extensive use of aggregate material in highway construction (primarily subbase) in Pennsylvania, the Pennsylvania Department of Transportation (PennDOT) initiated an indepth analysis of results of laboratory and field compaction tests on aggregates. This study determined what field and laboratory tests are best correlated to produce the optimum compaction control technique for subbase materials. Results of approximately 500 sand cone and nuclear field densities in crushed limestone, gravel, and slag material at 17 construction sites throughout the state are summarized and compared. Laboratory density tests on material from each of these field test sites include vibratory, standard moisture-density, modified moisture density, the Marshall test, and the vibratory hammer test. Regression correlation analyses are performed between maximum attainable field and laboratory densities. Estimating linear equations for predicting relationships between field and laboratory maximum densities are developed and their significance is discussed

  6. Prospective study comparing laparoscopic and open adenomectomy: Surgical and functional results.

    Science.gov (United States)

    Garcia-Segui, A; Angulo, J C

    Open adenomectomy (OA) is the surgery of choice for large volume benign prostatic hyperplasia, and laparoscopic adenomectomy (LA) represents a minimally invasive alternative. We present a long-term, prospective study comparing both techniques. The study consecutively included 199 patients with benign prostatic hyperplasia and prostate volumes>80g who were followed for more than 12 months. The patients underwent OA (n=97) or LA (n=102). We recorded and compared demographic and perioperative data, functional results and complications using a descriptive statistical analysis. The mean age was 69.2±7.7 years (range 42-87), and the mean prostate volume (measured by TRUS) was 112.1±32.7mL (range 78-260). There were no baseline differences among the groups in terms of age, ASA scale, prostate volume, PSA levels, Qmax, IPSS, QoL or treatments prior to the surgery. The surgical time (P<.0001) and catheter time (P<.0002) were longer in the LA group. Operative bleeding (P<.0001), transfusion rate (P=.0015) and mean stay (P<.0001) were significantly lower in the LA group. The LA group had a lower rate of complications (P=.04), but there were no significant differences between the groups in terms of major complications (Clavien score≥3) (P=.13) or in the rate of late complications (at one year) (P=.66). There were also no differences between the groups in the functional postoperative results: IPSS (P=.17), QoL (P=.3) and Qmax (P=.17). LA is a reasonable, safe and effective alternative that results in less bleeding, fewer transfusions, shorter hospital stays and lower morbidity than OA. LA has similar functional results to OA, at the expense of longer surgical times and longer catheter times. Copyright © 2016 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Comparative flood damage model assessment: towards a European approach

    Science.gov (United States)

    Jongman, B.; Kreibich, H.; Apel, H.; Barredo, J. I.; Bates, P. D.; Feyen, L.; Gericke, A.; Neal, J.; Aerts, J. C. J. H.; Ward, P. J.

    2012-12-01

    There is a wide variety of flood damage models in use internationally, differing substantially in their approaches and economic estimates. Since these models are being used more and more as a basis for investment and planning decisions on an increasingly large scale, there is a need to reduce the uncertainties involved and develop a harmonised European approach, in particular with respect to the EU Flood Risks Directive. In this paper we present a qualitative and quantitative assessment of seven flood damage models, using two case studies of past flood events in Germany and the United Kingdom. The qualitative analysis shows that modelling approaches vary strongly, and that current methodologies for estimating infrastructural damage are not as well developed as methodologies for the estimation of damage to buildings. The quantitative results show that the model outcomes are very sensitive to uncertainty in both vulnerability (i.e. depth-damage functions) and exposure (i.e. asset values), whereby the first has a larger effect than the latter. We conclude that care needs to be taken when using aggregated land use data for flood risk assessment, and that it is essential to adjust asset values to the regional economic situation and property characteristics. We call for the development of a flexible but consistent European framework that applies best practice from existing models while providing room for including necessary regional adjustments.

  8. Bipolar mixed features - Results from the comparative effectiveness for bipolar disorder (Bipolar CHOICE) study.

    Science.gov (United States)

    Tohen, Mauricio; Gold, Alexandra K; Sylvia, Louisa G; Montana, Rebecca E; McElroy, Susan L; Thase, Michael E; Rabideau, Dustin J; Nierenberg, Andrew A; Reilly-Harrington, Noreen A; Friedman, Edward S; Shelton, Richard C; Bowden, Charles L; Singh, Vivek; Deckersbach, Thilo; Ketter, Terence A; Calabrese, Joseph R; Bobo, William V; McInnis, Melvin G

    2017-08-01

    DSM-5 changed the criteria from DSM-IV for mixed features in mood disorder episodes to include non-overlapping symptoms of depression and hypomania/mania. It is unknown if, by changing these criteria, the same group would qualify for mixed features. We assessed how those meeting DSM-5 criteria for mixed features compare to those meeting DSM-IV criteria. We analyzed data from 482 adult bipolar patients in Bipolar CHOICE, a randomized comparative effectiveness trial. Bipolar diagnoses were confirmed through the MINI International Neuropsychiatric Interview (MINI). Presence and severity of mood symptoms were collected with the Bipolar Inventory of Symptoms Scale (BISS) and linked to DSM-5 and DSM-IV mixed features criteria. Baseline demographics and clinical variables were compared between mood episode groups using ANOVA for continuous variables and chi-square tests for categorical variables. At baseline, the frequency of DSM-IV mixed episodes diagnoses obtained with the MINI was 17% and with the BISS was 20%. Using DSM-5 criteria, 9% of participants met criteria for hypomania/mania with mixed features and 12% met criteria for a depressive episode with mixed features. Symptom severity was also associated with increased mixed features with a high rate of mixed features in patients with mania/hypomania (63.8%) relative to those with depression (8.0%). Data on mixed features were collected at baseline only and thus do not reflect potential patterns in mixed features within this sample across the study duration. The DSM-5 narrower, non-overlapping definition of mixed episodes resulted in fewer patients who met mixed criteria compared to DSM-IV. Copyright © 2017. Published by Elsevier B.V.

  9. Domain analysis and modeling to improve comparability of health statistics.

    Science.gov (United States)

    Okada, M; Hashimoto, H; Ohida, T

    2001-01-01

    Health statistics is an essential element to improve the ability of managers of health institutions, healthcare researchers, policy makers, and health professionals to formulate appropriate course of reactions and to make decisions based on evidence. To ensure adequate health statistics, standards are of critical importance. A study on healthcare statistics domain analysis is underway in an effort to improve usability and comparability of health statistics. The ongoing study focuses on structuring the domain knowledge and making the knowledge explicit with a data element dictionary being the core. Supplemental to the dictionary are a domain term list, a terminology dictionary, and a data model to help organize the concepts constituting the health statistics domain.

  10. [Comparability study of analytical results between a group of clinical laboratories].

    Science.gov (United States)

    Alsius-Serra, A; Ballbé-Anglada, M; López-Yeste, M L; Buxeda-Figuerola, M; Guillén-Campuzano, E; Juan-Pereira, L; Colomé-Mallolas, C; Caballé-Martín, I

    2015-01-01

    To describe the study of the comparability of the measurements levels of biological tests processed in biochemistry in Catlab's 4 laboratories. Quality requirements, coefficients of variation and total error (CV% and TE %) were established. Controls were verified with the precision requirements (CV%) in each test and each individual laboratory analyser. Fresh serum samples were used for the comparability study. The differences were analysed using a Microsoft Access® application that produces modified Bland-Altman plots. The comparison of 32 biological parameters that are performed in more than one laboratory and/or analyser generated 306 Bland-Altman graphs. Of these, 101 (33.1%) fell within the accepted range of values based on biological variability, and 205 (66.9%) required revision. Data were re-analysed based on consensus minimum specifications for analytical quality (consensus of the Asociación Española de Farmacéuticos Analistas (AEFA), the Sociedad Española de Bioquímica Clínica y Patología Molecular (SEQC), the Asociación Española de Biopatología Médica (AEBM) and the Sociedad Española de Hematología y Hemoterapia (SEHH), October 2013). With the new specifications, 170 comparisons (56%) fitted the requirements and 136 (44%) required additional review. Taking into account the number of points that exceeded the requirement, random errors, range of results in which discrepancies were detected, and range of clinical decision, it was shown that the 44% that required review were acceptable, and the 32 tests were comparable in all laboratories and analysers. The analysis of the results showed that the consensus requirements of the 4 scientific societies were met. However, each laboratory should aim to meet stricter criteria for total error. Copyright © 2015 SECA. Published by Elsevier Espana. All rights reserved.

  11. Convergence models for cylindrical caverns and the resulting ground subsidence

    Energy Technology Data Exchange (ETDEWEB)

    Haupt, W.; Sroka, A.; Schober, F.

    1983-02-01

    The authors studied the effects of different convergence characteristics on surface soil response for the case of narrow, cylindrical caverns. Maximum ground subsidence - a parameter of major importance in this type of cavern - was calculated for different convergence models. The models were established without considering the laws of rock mechanics and rheology. As a result, two limiting convergence models were obtained that describe an interval of expectation into which all other models fit. This means that ground movements over cylindrical caverns can be calculated ''on the safe side'', correlating the trough resulting on the surface with the convergence characterisitcs of the cavern. Among other applications, the method thus permits monitoring of caverns.

  12. The comparative analysis of results of surgical treatment of myasthenia in the remote periods of disease

    Directory of Open Access Journals (Sweden)

    L. Zaslavsky

    2016-01-01

    Full Text Available Based on long-term follow-up to perform comparative analysis of long-term results of surgical treatment of myasthenia. A retrospective analysis of long-term results of surgical treatment of 146 patients with myasthenia has been carried out. We used the modified Keynes classification to estimate the severity of myasthenia and to summarize the data relating to therapy volume and treatment results. In dependence on the type of thymus lesion patients were divided into two groups. Thymus hyperplasia was verified at — 106 (72.6 % patients, tumor lesion of the thymus gland (thymoma — at 40 (27.4 % ones. The results were estimated in the following periods after thymectomy: 1—2 years, 3—4 years, 5—6 years, 7 — 9 years, 10—14 years, and over 15 years. Short- and longterm results of surgical treatment of myasthenia for the patients without tumor lesions of the thymus gland were significantly better. Positive effects of surgical treatment of myasthenia in patients with hyperplasia are observed after 1 year of surgery (p = 0.0023, and the best results are observed after 5 — 6 year of the disease, then after 7 — 9 year one notes some deterioration of state (p = 0.026. In the myasthenia patients with thymoma one notes the similar trends in dynamics of state, but in general, the results are significantly (p = 0.042 badly than in the group of the patients with hyperplasia. Starting from the first year after operation treatment the patients with myasthenia with thymus hyperplasia have statistically significant (p = 0.048 decrease of average doses of glucocorticoids, and anticholinesterase drugs. The statistically best treatment results were noted for the patients operated at the first year of the disease. Positive result of surgical treatment of myasthenia is noted both in the short- and long-term period and at thymomas. In the group of patients with thymoma one has noted significantly badly results in comparison with group of hyperplasia. It is

  13. Meteorological Uncertainty of atmospheric Dispersion model results (MUD)

    DEFF Research Database (Denmark)

    Havskov Sørensen, Jens; Amstrup, Bjarne; Feddersen, Henrik

    . However, recent developments in numerical weather prediction (NWP) include probabilistic forecasting techniques, which can be utilised also for atmospheric dispersion models. The ensemble statistical methods developed and applied to NWP models aim at describing the inherent uncertainties......The MUD project addresses assessment of uncertainties of atmospheric dispersion model predictions, as well as optimum presentation to decision makers. Previously, it has not been possible to estimate such uncertainties quantitatively, but merely to calculate the 'most likely' dispersion scenario...... of the meteorological model results. These uncertainties stem from e.g. limits in meteorological obser-vations used to initialise meteorological forecast series. By perturbing the initial state of an NWP model run in agreement with the available observa-tional data, an ensemble of meteorological forecasts is produced...

  14. Meteorological Uncertainty of atmospheric Dispersion model results (MUD)

    DEFF Research Database (Denmark)

    Havskov Sørensen, Jens; Amstrup, Bjarne; Feddersen, Henrik

    ’ dispersion scenario. However, recent developments in numerical weather prediction (NWP) include probabilistic forecasting techniques, which can be utilised also for long-range atmospheric dispersion models. The ensemble statistical methods developed and applied to NWP models aim at describing the inherent......The MUD project addresses assessment of uncertainties of atmospheric dispersion model predictions, as well as possibilities for optimum presentation to decision makers. Previously, it has not been possible to estimate such uncertainties quantitatively, but merely to calculate the ‘most likely...... uncertainties of the meteorological model results. These uncertainties stem from e.g. limits in meteorological observations used to initialise meteorological forecast series. By perturbing e.g. the initial state of an NWP model run in agreement with the available observational data, an ensemble...

  15. Preliminary results of the comparative study between EO-1/Hyperion and ALOS/PALSAR

    Science.gov (United States)

    Koizumi, E.; Furuta, R.; Yamamoto, A.

    2011-12-01

    [Introduction]Hyper-spectral remote sensing images have been used for land-cover classification due to their high spectral resolutions. Synthetic Aperture Radar (SAR) remote sensing data are also useful to probe surface condition because radar image reflects surface geometry, although there are not so many reports about the land-cover detection with combination use of both hyper-spectral data and SAR data. Among SAR sensors, L-band SAR is thought to be useful tool to find physical properties because its comparatively long wave length can through small objects on surface. We are comparing the result of land cover classification and/or physical values from hyper-spectral and L-band SAR data to find the relationship between these two quite different sensors and to confirm the possibility of the combined analysis of hyper-spectral and L-band SAR data, and in this presentation we will report the preliminary result of this study. There are only few sources of both hyper-spectral and L-band SAR data from the space in this time, however, several space organizations plan to launch new satellites on which hyper-spectral or L-band SAR equipments are mounted in next few years. So, the importance of the combined analysis will increase more than ever. [Target Area]We are performing and planning analyses on the following areas in this study. (a)South of Cairo, Nile river area, Egypt, for sand, sandstone, limestone, river, crops. (b)Mount Sakurajima, Japan, for igneous rock and other related geological property. [Methods and Results]EO-1 Hyperion data are analyzed in this study as hyper-spectral data. The Hyperion equipment has 242 channels but some of them include full noise or have no data. We selected channels for analysis by checking each channel, and select about 150 channels (depend on the area). Before analysis, the atmospheric correction of ATCOR-3 was applied for the selected channels. The corrected data were analyzed by unsupervised classification or principal component

  16. The 2013 European Seismic Hazard Model: key components and results

    OpenAIRE

    Jochen Woessner; Danciu Laurentiu; Domenico Giardini; Helen Crowley; Fabrice Cotton; G. Grünthal; Gianluca Valensise; Ronald Arvidsson; Roberto Basili; Mine Betül Demircioglu; Stefan Hiemer; Carlo Meletti; Roger W. Musson; Andrea N. Rovida; Karin Sesetyan

    2015-01-01

    The 2013 European Seismic Hazard Model (ESHM13) results from a community-based probabilistic seismic hazard assessment supported by the EU-FP7 project “Seismic Hazard Harmonization in Europe” (SHARE, 2009–2013). The ESHM13 is a consistent seismic hazard model for Europe and Turkey which overcomes the limitation of national borders and includes a through quantification of the uncertainties. It is the first completed regional effort contributing to the “Global Earthquake Model” initiative. It m...

  17. Results of a model for premixed combustion oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Janus, M.C.; Richards, G.A.

    1996-09-01

    Combustion oscillations are receiving renewed research interest due to increasing use of lean premix (LPM) combustion to gas turbines. A simple, nonlinear model for premixed combustion is described in this paper. The model was developed to help explain specific experimental observations and to provide guidance for development of active control schemes based on nonlinear concepts. The model can be used to quickly examine instability trends associated with changes in equivalence ratio, mass flow rate, geometry, ambient conditions, etc. The model represents the relevant processes occurring in a fuel nozzle and combustor which are analogous to current LPM turbine combustors. Conservation equations for the fuel nozzle and combustor are developed from simple control volume analysis, providing a set of ordinary differential equations that can be solved on a personal computer. Combustion is modeled as a stirred reactor, with a bimolecular reaction rate between fuel and air. A variety of numerical results and comparisons to experimental data are presented to demonstrate the utility of the model. Model results are used to understand the fundamental mechanisms which drive combustion oscillations, effects of inlet air temperature and nozzle geometry on instability, and effectiveness of open loop control schemes.

  18. Summary of FY15 results of benchmark modeling activities

    Energy Technology Data Exchange (ETDEWEB)

    Arguello, J. Guadalupe [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-08-01

    Sandia is participating in the third phase of an is a contributing partner to a U.S.-German "Joint Project" entitled "Comparison of current constitutive models and simulation procedures on the basis of model calculations of the thermo-mechanical behavior and healing of rock salt." The first goal of the project is to check the ability of numerical modeling tools to correctly describe the relevant deformation phenomena in rock salt under various influences. Achieving this goal will lead to increased confidence in the results of numerical simulations related to the secure storage of radioactive wastes in rock salt, thereby enhancing the acceptance of the results. These results may ultimately be used to make various assertions regarding both the stability analysis of an underground repository in salt, during the operating phase, and the long-term integrity of the geological barrier against the release of harmful substances into the biosphere, in the post-operating phase.

  19. Building v/s Exploring Models: Comparing Learning of Evolutionary Processes through Agent-based Modeling

    Science.gov (United States)

    Wagh, Aditi

    Two strands of work motivate the three studies in this dissertation. Evolutionary change can be viewed as a computational complex system in which a small set of rules operating at the individual level result in different population level outcomes under different conditions. Extensive research has documented students' difficulties with learning about evolutionary change (Rosengren et al., 2012), particularly in terms of levels slippage (Wilensky & Resnick, 1999). Second, though building and using computational models is becoming increasingly common in K-12 science education, we know little about how these two modalities compare. This dissertation adopts agent-based modeling as a representational system to compare these modalities in the conceptual context of micro-evolutionary processes. Drawing on interviews, Study 1 examines middle-school students' productive ways of reasoning about micro-evolutionary processes to find that the specific framing of traits plays a key role in whether slippage explanations are cued. Study 2, which was conducted in 2 schools with about 150 students, forms the crux of the dissertation. It compares learning processes and outcomes when students build their own models or explore a pre-built model. Analysis of Camtasia videos of student pairs reveals that builders' and explorers' ways of accessing rules, and sense-making of observed trends are of a different character. Builders notice rules through available blocks-based primitives, often bypassing their enactment while explorers attend to rules primarily through the enactment. Moreover, builders' sense-making of observed trends is more rule-driven while explorers' is more enactment-driven. Pre and posttests reveal that builders manifest a greater facility with accessing rules, providing explanations manifesting targeted assembly. Explorers use rules to construct explanations manifesting non-targeted assembly. Interviews reveal varying degrees of shifts away from slippage in both

  20. Comparative Analysis Of Three Largest World Models Of Business Excellence

    Directory of Open Access Journals (Sweden)

    Jasminka Samardžija

    2009-07-01

    Full Text Available Business excellence has become the strongest means of achieving competitive advantage of companies while total management of quality has become the road that ensures support of excellent results recognized by many world companies. Despite many differences, we can conclude that models have many common elements. By the audit in 2005, the DP and MBNQA moved the focus from excellence of product, i.e service, onto the excellence of quality of the entire organization process. Thus, the quality got strategic dimension instead of technical one and the accent passed from the technical quality on the total excellence of all organization processes. The joint movement goes to the direction of good management and appreciation of systems thinking. The very structure of EFOM model criteria itself is adjusted to strategic dimension of quality and that is why the model underwent only short audits within the criteria themselves. Essentially, the model remained unchanged. In all models, the accent is on the satisfaction of buyers, employees and community. National rewards for quality have an important role in promotion and giving a prize to excellence in organization performances. Moreover, they raise quality standards of companies and the country profile as a whole. Considering the GDP per capita and the percentage of certification level of companies, Croatia has all the predispositions for introduction the EFQM model of business excellence with the basic aim of deficit decrease in foreign trade balance and strengthening of competitiveness as the necessary preliminary work for the entrance in the competitive market of the EU. Quality management was introduced in many organizations. The methods used at that time developed in the course of years, and what are to predict is the continuation of the evolution road model as well as the method of business excellence.

  1. Pore water pressure variations in Subpermafrost groundwater : Numerical modeling compared with experimental modeling

    Science.gov (United States)

    Rivière, Agnès.; Goncalves, Julio; Jost, Anne; Font, Marianne

    2010-05-01

    Development and degradation of permafrost directly affect numerous hydrogeological processes such as thermal regime, exchange between river and groundwater, groundwater flows patterns and groundwater recharge (Michel, 1994). Groundwater in permafrost area is subdivided into two zones: suprapermafrost and subpermafrost which are separated by permafrost. As a result of the volumetric expansion of water upon freezing and assuming ice lenses and frost heave do not form freezing in a saturated aquifer, the progressive formation of permafrost leads to the pressurization of the subpermafrost groundwater (Wang, 2006). Therefore disappearance or aggradation of permafrost modifies the confined or unconfined state of subpermafrost groundwater. Our study focuses on modifications of pore water pressure of subpermafrost groundwater which could appear during thawing and freezing of soil. Numerical simulation allows elucidation of some of these processes. Our numerical model accounts for phase changes for coupled heat transport and variably saturated flow involving cycles of freezing and thawing. The flow model is a combination of a one-dimensional channel flow model which uses Manning-Strickler equation and a two-dimensional vertically groundwater flow model using Richards equation. Numerical simulation of heat transport consisted in a two dimensional model accounting for the effects of latent heat of phase change of water associated with melting/freezing cycles which incorporated the advection-diffusion equation describing heat-transfer in porous media. The change of hydraulic conductivity and thermal conductivity are considered by our numerical model. The model was evaluated by comparing predictions with data from laboratory freezing experiments. Experimental design was undertaken at the Laboratory M2C (Univesité de Caen-Basse Normandie, CNRS, France). The device consisted of a Plexiglas box insulated on all sides except on the top. Precipitation and ambient temperature are

  2. Prospective study comparing laparoscopic and open radical cystectomy: Surgical and oncological results.

    Science.gov (United States)

    Esquinas, C; Alonso, J M; Mateo, E; Dotor, A; Martín, A M; Dorado, J F; Arance, I; Angulo, J C

    2018-03-01

    Laparoscopic radical cystectomy with lymphadenectomy and urinary diversion is an increasingly widespread operation. Studies are needed to support the oncological effectiveness and safety of this minimally invasive approach. A nonrandomised, comparative prospective study between open radical cystectomy (ORC) and laparoscopic radical cystectomy (LRC) was conducted in a university hospital. The main objective was to compare cancer-specific survival. The secondary objective was to compare the surgical results and complications according to the Clavien-Dindo scale. We treated 156 patients with high-grade invasive bladder cancer with either ORC (n=70) or LRC (n=86). The mean follow-up was 33.5±23.8 (range 12-96) months. The mean age was 66.9+9.4 years, and the male to female ratio was 19:1. Both groups were equivalent in age, stage, positive lymph nodes, in situ carcinoma, preoperative obstructive uropathy, adjuvant chemotherapy and type of urinary diversion. There were no differences between the groups in terms of cancer-specific survival (log-rank; P=.71). The histopathology stage was the only independent variable that predicted the prognosis. The hospital stay (P=.01) and operative transfusion rates (P=.002) were less for LRC. The duration of the surgery was greater for LRC (P<.001). There were no differences in the total complications rate (p=.62) or major complications (P=.69). The risk of evisceration (P=.02), surgical wound infection (P=.005) and pneumonia (P=.017) was greater for ORC. The risk of rectal lesion (P=.017) and urethrorectal fistulae (P=.065) was greater for LRC. LRC is an equivalent treatment to ORC in terms of oncological efficacy and is advantageous in terms of transfusion rates and hospital stays but not in terms of operating room time and overall safety. Studies are needed to better define the specific safety profile for each approach. Copyright © 2017 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. [Results of arthrodiastasis in postraumatic ankle osteoarthritis in a young population: prospective comparative study].

    Science.gov (United States)

    Herrera-Pérez, M; Pais-Brito, J L; de Bergua-Domingo, J; Aciego de Mendoza, M; Guerra-Ferraz, A; Cortés-García, P; Déniz-Rodríguez, B

    2013-01-01

    The most common cause of osteoarthritis of the ankle is post-traumatic, and although tibiotalar arthrodesis remains the surgical gold standard, a number of techniques have been described to preserve joint mobility, such as joint distraction arthroplasty or arthrodiastasis. To evaluate the functional outcome and changes in Visual Analogue Scale (VAS) for pain after the application of the distraction arthroplasty for post-traumatic ankle osteoarthritis. A prospective comparative study of a group of 10 young patients with post-traumatic ankle osteoarthritis treated by synovectomy and arthrodiastasis, compared to a control group of 10 patients treated by isolated synovectomy. Results were calculated using the AOFAS scale and the VAS for pain before and after treatment. As regards the pain measured by VAS, no difference was observed between the two groups before surgery (P=.99), but there was a difference at 3 months (P<.001), 6 months (P=.005), and 12 months (P=.006). No differences were observed in the AOFAS scale between the two groups before surgery (P=.99), or at 3 months (P<.99), but there was a difference at 6 months (P<.001). Ankle arthrodiastasis is effective in reducing pain in post-traumatic ankle arthropathy, and is superior to isolated synovectomy. © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

  4. How do farm models compare when estimating greenhouse gas emissions from dairy cattle production?

    DEFF Research Database (Denmark)

    Hutchings, Nicholas John; Özkan, Şeyda; de Haan, M

    2018-01-01

    feed imported. This was because the models differed in their description of biophysical responses and feedback mechanisms, and in the extent to which management functions were internalised. We conclude that comparing the results of different farm-scale models when applied to a range of scenarios would...

  5. Comparing and interpreting laboratory results of Hg oxidation by a chlorine species

    International Nuclear Information System (INIS)

    Agarwal, Hans; Romero, Carlos E.; Stenger, Harvey G.

    2007-01-01

    Several researchers have performed experimental work in attempts to explain the effects of various flue-gas components on the oxidation of elemental mercury (Hg 0 ). Some have concluded that water (H 2 O) inhibits Hg oxidation by chlorine (Cl 2 ). In recently published work, it was found that sulfur dioxide (SO 2 ) and nitric oxide (NO) also have an inhibitory effect on Hg oxidation. This paper aims to serve three purposes. First, to present data obtained in a laboratory scale apparatus, designed to test the effects of Cl 2 on the oxidation of Hg 0 with respect to temperature. The results show that as temperature increases, Cl 2 is less effective as an Hg oxidizing agent. Second, this paper presents a consolidation of data taken from several sources, where the effects of various flue-gas components on the oxidation of Hg 0 is observed and discussed. The summary of these results shows the following general trends: at high temperatures, hydrogen chloride (HCl) is the primary chlorine species responsible for Hg 0 oxidation, while at lower temperatures, Cl 2 is the dominant species. Third, a simple two reaction model is suggested to predict the experimental data shown in this paper. The results show that the predicted percent Hg oxidation values correspond very well with the observed experimental values

  6. [Gonalgia: treatment with therapeutic local anesthesia. Results of a controlled comparative study versus diclofenac].

    Science.gov (United States)

    Berenfeld, A; Bessing, W D; Bisplinghoff, U; Bittner, G; Matthiesen, H O; Tilscher, H; Ramm, S; Ebeling, L; Schmitz, H

    1991-12-10

    The effectiveness and tolerance of therapeutic local anesthesia (TLA) with lidocaine was compared with those of oral diclofenac in a controlled, open, randomized study involving 76 patients with gonalgia due to gonarthrosis or patellar chondropathy. During the course of the three-week (maximum) treatment, the summed score of pain at rest, pain on movement, and restricted mobility, taken as the target parameter of effectiveness, decreased significantly more markedly (p = 0.008) under TLA, than under diclofenac. Side effects involving mainly the gastrointestinal tract occurred significantly more frequently in the diclofenac group (p = 0.012). The results of this study indicate that in the treatment of localized joint pain of degenerative genesis, TLA with lidocaine is superior to NSAID treatment in terms of effectiveness and tolerance.

  7. Comparative evaluation results of CMS replacement resist for e-beam reticle fabrication

    CERN Document Server

    Kobayashi, H; Asakawa, K; Yokoya, Y; Wada, T

    1999-01-01

    Looking for a CMS replacement resist is an urgent assignment for e- beam reticle fabrication, which enables us to maintain flexibility of reticle fabrications. The CMS-EX series was discontinued in 1995, and its stored resin will be used up completely soon in this year 1999. We then tried to find a replacement resist, and examined commercially available resists SEL-N1000, SEL-N1100 and ZEN4400. We studied their behavior to post-spin baking temperature, in order to bring out their potential, by investigating isolated clear pattern fidelity in details as it was the most tough one to make by a negative-working resist. This paper describes our comparative evaluation results of commercially available negative-working resists to determine a CMS- EX-S replacement for e-beam reticle fabrication. (4 refs).

  8. Curriculum inventory: Modeling, sharing and comparing medical education programs.

    Science.gov (United States)

    Ellaway, Rachel H; Albright, Susan; Smothers, Valerie; Cameron, Terri; Willett, Timothy

    2014-03-01

    Abstract descriptions of how curricula are structured and run. The American National Standards Institute (ANSI) MedBiquitous Curriculum Inventory Standard provides a technical syntax through which a wide range of different curricula can be expressed and subsequently compared and analyzed. This standard has the potential to shift curriculum mapping and reporting from a somewhat disjointed and institution-specific undertaking to something that is shared among multiple medical schools and across whole medical education systems. Given the current explosion of different models of curricula (time-free, competency-based, socially accountable, distributed, accelerated, etc.), the ability to consider this diversity using a common model has particular value in medical education management and scholarship. This article describes the development and structure of the Curriculum Inventory Standard as a way of standardizing the modeling of different curricula for audit, evaluation and research purposes. It also considers the strengths and limitations of the current standard and the implications for a medical education world in which this level of commonality, precision, and accountability for curricular practice is the norm rather than the exception.

  9. Comparing Plusoptix A09 photorefractometer results with autorefractometer using Bland-Altman analysis

    Directory of Open Access Journals (Sweden)

    Ayse Dolar Bilg

    2017-03-01

    Full Text Available AIM: To evaluate the accuracy of the Plusoptix A09 photorefraction with and without cycloplegia compared to an autorefractometer in pediatric patients.METHODS: We assessed the refractive status of 180 eyes in 90 pediatric patients. Refractions were measured with the Plusoptix A09 photorefractor(Plusoptix GmbH, Nürnberg, Germanywith and without cycloplegia and compared with those obtained by autorefractometer(Topcon KR-8900, Tokyo, Japanafter cycloplegia. Spherical equivalent, spherical power cylindrical power and cylindrical axis J0, J45 values measurements were analyzed with Bland-Altman analysis. RESULTS: The mean age of the patients was 7.48±3.01(range 3 to 13y. Between the non-cycloplegic Plusoptix A09 photorefractometer and the cycloplegic autorefractometer measurements, there was significant difference between spherical power and spherical equivalent values(PP>0.05. Between the cycloplegic Plusoptix A09 photorefractometer and the cycloplegic autorefractometer measurements, there was significant difference between spherical power and spherical equivalent values(PP>0.05. Bland-Altman correlation analysis revealed an excellent correlation for the spherical power, cylindrical power and spherical equivalent measurements, but poor correlation for J0 and J45 values between the non-cycloplegic, cycloplegic Plusoptix A09 and the cycloplegic autorefractometer measurements.CONCLUSION: To determine refractive errors in children, the Plusoptix A09 measurements with and without cycloplegia can give reliable results. But it is inadequate when measuring the cylindrical axis and high refractive values. This device can be an effective option to detect and screen refractive errors in uncooperative children.

  10. The Eccentric Satellites Problem: Comparing Milky Way Satellite Orbital Properties to Simulation Results

    Science.gov (United States)

    Haji, Umran; Pryor, Carlton; Applebaum, Elaad; Brooks, Alyson

    2018-01-01

    We compare the orbital properties of the satellite galaxies of the Milky Way to those of satellites found in simulated Milky Way-like systems as a means of testing cosmological simulations of galaxy formation. The particular problem that we are investigating is a discrepancy in the distribution of orbital eccentricities. Previous studies of Milky Way-mass systems analyzed in a semi-analytic ΛCDM cosmological model have found that the satellites tend to have significantly larger fractions of their kinetic energy invested in radial motion with respect to their central galaxy than do the real-world Milky Way satellites. We analyze several high-resolution ("zoom-in") hydrodynamical simulations of Milky Way-mass galaxies and their associated satellite systems to investigate why previous works found Milky Way-like systems to be rare. We find a possible relationship between a quiescent galactic assembly history and a distribution of satellite kinematics resembling that of the Milky Way. This project has been supported by funding from National Science Foundation grant PHY-1560077.

  11. Comparative Modeling of a Parabolic Trough Collectors Solar Power Plant with MARS Models

    Directory of Open Access Journals (Sweden)

    Jose Ramón Rogada

    2017-12-01

    Full Text Available Power plants producing energy through solar fields use a heat transfer fluid that lends itself to be influenced and changed by different variables. In solar power plants, a heat transfer fluid (HTF is used to transfer the thermal energy of solar radiation through parabolic collectors to a water vapor Rankine cycle. In this way, a turbine is driven that produces electricity when coupled to an electric generator. These plants have a heat transfer system that converts the solar radiation into heat through a HTF, and transfers that thermal energy to the water vapor heat exchangers. The best possible performance in the Rankine cycle, and therefore in the thermal plant, is obtained when the HTF reaches its maximum temperature when leaving the solar field (SF. In addition, it is necessary that the HTF does not exceed its own maximum operating temperature, above which it degrades. The optimum temperature of the HTF is difficult to obtain, since the working conditions of the plant can change abruptly from moment to moment. Guaranteeing that this HTF operates at its optimal temperature to produce electricity through a Rankine cycle is a priority. The oil flowing through the solar field has the disadvantage of having a thermal limit. Therefore, this research focuses on trying to make sure that this fluid comes out of the solar field with the highest possible temperature. Modeling using data mining is revealed as an important tool for forecasting the performance of this kind of power plant. The purpose of this document is to provide a model that can be used to optimize the temperature control of the fluid without interfering with the normal operation of the plant. The results obtained with this model should be necessarily contrasted with those obtained in a real plant. Initially, we compare the PID (proportional–integral–derivative models used in previous studies for the optimization of this type of plant with modeling using the multivariate adaptive

  12. Results of a clinical trial comparing conservative and modified radical mastectomy for early breast cancer

    International Nuclear Information System (INIS)

    Du Xianghui; Wang Yuezhen; Wu Lie; Zhu Yuan; Yang Hongjian; Zou Dehong

    2005-01-01

    Objective: The influence of conservative mastectomy plus postoperative radiation (CM + RT) in local control, distant failure, cosmetic and psychological outcome for early stage breast cancer was evaluated comparing with modified radical mastectomy. Methods: Between January 1998 and December 2003, 68 early stage breast cancer patients underwent CM + RT. During the save period, 76 similar patients were treated by modified radical mastectomy (MRM + RT). The cosmetic results evaluated as 'excellent', 'fair' or 'poor' using specific guide lines together with their psychological changes. Sex life and marital stability were also recorded. All patients were female with median age of 44.5 years (range, 28-62 years). Guidelines for patient selection reported by National Breast Cancer Cooperative Group was adhered to. In general, CM consisted of wide local excision with the breast conserved and postoperative radiotherapy to the entire breast with tangential fields followed by a boost to the tumor bed. All patients also received adjuvant chemotherapy with CAF. Patients with positive ER or PR assay results received tamoxifen for 5 years. In the 76 MRM + RT patients, the post operative radiotherapy and chemotherapy were given as clinically indicated. Results: There was no failure locally in all. In CM + RT group, the cause of failure was bone metastasis in 1 and mutiple metastasis in 2. In the MRM + RT group, the cause of failure was bone metastasis in 2, brain metastasis in 1 and mutiple metastases in 1. The cosmetic scores were 91.2% excellent, 5.6% fair and 2.9% poor. Conclusions: Breast preservation by conservative mastectomy is preferable to mastectomy in appropriately selected patients as it provides equivalent survival but giving good cosmetic results. (authors)

  13. Relationship Marketing results: proposition of a cognitive mapping model

    Directory of Open Access Journals (Sweden)

    Iná Futino Barreto

    2015-12-01

    Full Text Available Objective - This research sought to develop a cognitive model that expresses how marketing professionals understand the relationship between the constructs that define relationship marketing (RM. It also tried to understand, using the obtained model, how objectives in this field are achieved. Design/methodology/approach – Through cognitive mapping, we traced 35 individual mental maps, highlighting how each respondent understands the interactions between RM elements. Based on the views of these individuals, we established an aggregate mental map. Theoretical foundation – The topic is based on a literature review that explores the RM concept and its main elements. Based on this review, we listed eleven main constructs. Findings – We established an aggregate mental map that represents the RM structural model. Model analysis identified that CLV is understood as the final result of RM. We also observed that the impact of most of the RM elements on CLV is brokered by loyalty. Personalization and quality, on the other hand, proved to be process input elements, and are the ones that most strongly impact others. Finally, we highlight that elements that punish customers are much less effective than elements that benefit them. Contributions - The model was able to insert core elements of RM, but absent from most formal models: CLV and customization. The analysis allowed us to understand the interactions between the RM elements and how the end result of RM (CLV is formed. This understanding improves knowledge on the subject and helps guide, assess and correct actions.

  14. Wave-current interactions: model development and preliminary results

    Science.gov (United States)

    Mayet, Clement; Lyard, Florent; Ardhuin, Fabrice

    2013-04-01

    The coastal area concentrates many uses that require integrated management based on diagnostic and predictive tools to understand and anticipate the future of pollution from land or sea, and learn more about natural hazards at sea or activity on the coast. The realistic modelling of coastal hydrodynamics needs to take into account various processes which interact, including tides, surges, and sea state (Wolf [2008]). These processes act at different spatial scales. Unstructured-grid models have shown the ability to satisfy these needs, given that a good mesh resolution criterion is used. We worked on adding a sea state forcing in a hydrodynamic circulation model. The sea state model is the unstructured version of WAVEWATCH III c (Tolman [2008]) (which version is developed at IFREMER, Brest (Ardhuin et al. [2010]) ), and the hydrodynamic model is the 2D barotropic module of the unstructured-grid finite element model T-UGOm (Le Bars et al. [2010]). We chose to use the radiation stress approach (Longuet-Higgins and Stewart [1964]) to represent the effect of surface waves (wind waves and swell) in the barotropic model, as previously done by Mastenbroek et al. [1993]and others. We present here some validation of the model against academic cases : a 2D plane beach (Haas and Warner [2009]) and a simple bathymetric step with analytic solution for waves (Ardhuin et al. [2008]). In a second part we present realistic application in the Ushant Sea during extreme event. References Ardhuin, F., N. Rascle, and K. Belibassakis, Explicit wave-averaged primitive equations using a generalized Lagrangian mean, Ocean Modelling, 20 (1), 35-60, doi:10.1016/j.ocemod.2007.07.001, 2008. Ardhuin, F., et al., Semiempirical Dissipation Source Functions for Ocean Waves. Part I: Definition, Calibration, and Validation, J. Phys. Oceanogr., 40 (9), 1917-1941, doi:10.1175/2010JPO4324.1, 2010. Haas, K. A., and J. C. Warner, Comparing a quasi-3D to a full 3D nearshore circulation model: SHORECIRC and

  15. High-resolution chronologies for loess: comparing AMS 14C and optical dating results

    Science.gov (United States)

    Lang, A.; Hatté, C.; Rousseau, D.-D.; Antoine, P.; Fontugne, M.; Zöller, L.; Hambach, U.

    2003-05-01

    The Nußloch loess section in South West Germany is famous in Central Europe for its thick deposits from the Last Glacial Maximum. It has therefore been intensively studied during the past few years and offers an excellent opportunity to compare the performance of different dating techniques covering the period 15-45 ka. Here we present results from optical and AMS 14C dating. The silt-sized polymineral fraction of the clastic sediments and a multiple-aliquot approach was used for IR-OSL dating. 14C dating was carried out on organic macro-remnants and humin fractions extracted from the sediments. With the exception of samples taken from the uppermost 1.5 m of the section, IR-OSL and calibrated 14C-AMS ages are consistent over the entire period. The inconsistencies in the upper meters are thought to be due to disturbances during soil formation in the Holocene. The good agreement obtained on the remaining sequence demonstrates the high accuracy of both methods when studying loess sections: for the IR-OSL ages no significant age underestimations are obvious. The results clearly document that accurate chronologies can be developed for such continental sedimentary sequences. This gives access to archives that can now be studied with a high temporal resolution and allows the establishment of new paleoclimatic proxies for the study of terrestrial responses to past climatic changes.

  16. Marginal production in the Gulf of Mexico - II. Model results

    International Nuclear Information System (INIS)

    Kaiser, Mark J.; Yu, Yunke

    2010-01-01

    In the second part of this two-part article on marginal production in the Gulf of Mexico, we estimate the number of committed assets in water depth less than 1000 ft that are expected to be marginal over a 60-year time horizon. We compute the expected quantity and value of the production and gross revenue streams of the gulf's committed asset inventory circa. January 2007 using a probabilistic model framework. Cumulative hydrocarbon production from the producing inventory is estimated to be 1056 MMbbl oil and 13.3 Tcf gas. Marginal production from the committed asset inventory is expected to contribute 4.1% of total oil production and 5.4% of gas production. A meta-evaluation procedure is adapted to present the results of sensitivity analysis. Model results are discussed along with a description of the model framework and limitations of the analysis. (author)

  17. Marginal production in the Gulf of Mexico - II. Model results

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, Mark J.; Yu, Yunke [Center for Energy Studies, Louisiana State University, Baton Rouge, LA 70803 (United States)

    2010-08-15

    In the second part of this two-part article on marginal production in the Gulf of Mexico, we estimate the number of committed assets in water depth less than 1000 ft that are expected to be marginal over a 60-year time horizon. We compute the expected quantity and value of the production and gross revenue streams of the gulf's committed asset inventory circa. January 2007 using a probabilistic model framework. Cumulative hydrocarbon production from the producing inventory is estimated to be 1056 MMbbl oil and 13.3 Tcf gas. Marginal production from the committed asset inventory is expected to contribute 4.1% of total oil production and 5.4% of gas production. A meta-evaluation procedure is adapted to present the results of sensitivity analysis. Model results are discussed along with a description of the model framework and limitations of the analysis. (author)

  18. Simulating SOFIA's image jitter performance and how the results compare to in-flight measurements

    Science.gov (United States)

    Graf, Friederike; Reinacher, Andreas; Spohr, Daniel; Jakob, Holger; Fasoulas, Stefanos

    2017-09-01

    SOFIA, the Stratospheric Observatory for Infrared Astronomy is an airborne telescope and in full operation since 2014. It has already successfully conducted over 400 flights and can be equipped with eight different science instruments which range from the visible to the far infrared wavelength regime. In order to reach SOFIA's scientific goals, the telescope has to provide a stable platform with the ambitous image jitter requirements of less than 0.4 "rms. Such a steady operating environment is especially important for slit spectrometers like EXES (Echelon - Cross - Echelle Spectrograph), that aim to keep the star in the area of a very thin slit for integration. Currently, image motion is mainly caused by deformation and excitation of the telescope structure in a wide range of frequencies. These disturbances are counteracted by the so-called Flexible Body Compensation system which uses a set of accelerometers to estimate the resulting image motion. To better study optimization possibilities of SOFIA's control system, a simulation tool has been developed which not only implements system identification data and analytically derived models, but also allows the implementation and verification with sensor data from in flight measurements. Results of the simulation as well as in flight measurements will be presented and improvement strategies will be discussed.

  19. Studies on the comparability of the results from different methods for the radioimmunological determination of digoxin

    International Nuclear Information System (INIS)

    Dwenger, A.; Trautschold, I.

    1978-01-01

    Three iodine-125-digoxin radioimmunoassay kits (A Amersham Buchler; B Boehringer Mannheim; C Schwarz Mann/Becton Dickinson) were evaluated with respect to assay quality and comparability of the results. Intra- and interassay variances were calculated for the following types of samples: Three media (a pool serum; b artificial human serum; c buffer solution with albumin and globulin) containing pure digoxin, sera from a pharmacokinetic study, sera with different concentrations of proteins, a hemolytic serum and sera with digitoxin and metabolites of spironolactone. The intra-assay precision depended on the medium of the sample and was higher for samples with identical digoxin concentrations in an identical medium (e.g. CV for 2 μg/l in medium a for kit A: 4.3% for kit B: 7.0%; for kit C: 2.2%) than for samples with identical antigen concentrations in different media (CV for 2 μg/l in media a, b and c for kit A: 6.4%; for kit B: 9.1%; for kit C: 4.3%). The mean recovery in the range 0.5-4 μg/l depended on the kind of medium (a, b or c) and varied for kit A from 84.4% to 100.8%, for kit B from 112.0% to 119.6%, and for kit C from 98.0% to 104.5%. Decreasing serum protein concentrations to less than one half of the physiological concentration gave false negative results for kit A and fals positive results for kit C; for kit B this dependency was not be observed, but there was a decrease of reproducibility. (orig./AJ) [de

  20. Results of CO2 Laser-assisted Deep Sclerectomy as Compared With Conventional Deep Sclerectomy.

    Science.gov (United States)

    Greifner, Gabriel; Roy, Sylvain; Mermoud, André

    2016-07-01

    To evaluate the efficacy of CO2 laser-assisted sclerectomy surgery (CLASS) compared with classic nonpenetrating deep sclerectomy (NPDS) with implant in medically uncontrolled glaucoma patients. Patients who underwent primary filtration surgery with CO2 laser system at the time interval between July 2010 and April 2011 were identified, their medical files were reviewed, and their results were compared with matched control group who underwent classic NPDS with intrascleral implant at the same time period. Intraocular pressure (IOP) was measured at baseline, 1 week, and 3, 6, 12, 18, and 24 months, respectively. Main outcome measures were: IOP, use of supplemental medical therapy, and failure (5 mm Hg>IOP>18 mm Hg, reoperation for glaucoma, or loss of light perception). A total of 58 patients were reviewed, including 27 in the CLASS group and 31 in the NPDS group. For the CLASS group the follow-up (mean±SD) was 20.7±6.8 months, the mean preoperative IOP was 23.3±8.2 mm Hg (range, 10 to 38 mm Hg), and the mean number of antiglaucoma medication before surgery was 3.0±1.0 (range, 1 to 4). At final follow-up visits, the mean IOP was 11.7±3.1 mm Hg (range, 6 to 19 mm Hg), and the mean number of antiglaucoma medication was reduced to 1.0±1.6 (PCO2-laser ablation system allows precise and easy creation of the scleral space and ablation of Schlemm canal. This technique has been shown to be as efficient as the standard NPDS surgery in terms of IOP-lowering effect. This would render the deep sclerectomy an easier glaucoma surgery.

  1. Comparative Research on RC Equivalent Circuit Models for Lithium-Ion Batteries of Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Lijun Zhang

    2017-09-01

    Full Text Available Equivalent circuit models are a hot research topic in the field of lithium-ion batteries for electric vehicles, and scholars have proposed a variety of equivalent circuit models, from simple to complex. On one hand, a simple model cannot simulate the dynamic characteristics of batteries; on the other hand, it is difficult to apply a complex model to a real-time system. At present, there are few systematic comparative studies on equivalent circuit models of lithium-ion batteries. The representative first-order resistor-capacitor (RC model and second-order RC model commonly used in the literature are studied comparatively in this paper. Firstly, the parameters of the two models are identified experimentally; secondly, the simulation model is built in Matlab/Simulink environment, and finally the output precision of these two models is verified by the actual data. The results show that in the constant current condition, the maximum error of the first-order RC model is 1.65% and the maximum error for the second-order RC model is 1.22%. In urban dynamometer driving schedule (UDDS condition, the maximum error of the first-order RC model is 1.88%, and for the second-order RC model the maximum error is 1.69%. This is of great instructional significance to the application in practical battery management systems for the equivalent circuit model of lithium-ion batteries of electric vehicles.

  2. The animal model determines the results of Aeromonas virulence factors

    Directory of Open Access Journals (Sweden)

    Alejandro Romero

    2016-10-01

    Full Text Available The selection of an experimental animal model is of great importance in the study of bacterial virulence factors. Here, a bath infection of zebrafish larvae is proposed as an alternative model to study the virulence factors of A. hydrophila. Intraperitoneal infections in mice and trout were compared with bath infections in zebrafish larvae using specific mutants. The great advantage of this model is that bath immersion mimics the natural route of infection, and injury to the tail also provides a natural portal of entry for the bacteria. The implication of T3SS in the virulence of A. hydrophila was analysed using the AH-1::aopB mutant. This mutant was less virulent than the wild-type strain when inoculated into zebrafish larvae, as described in other vertebrates. However, the zebrafish model exhibited slight differences in mortality kinetics only observed using invertebrate models. Infections using the mutant AH-1∆vapA lacking the gene coding for the surface S-layer suggested that this protein was not totally necessary to the bacteria once it was inside the host, but it contributed to the inflammatory response. Only when healthy zebrafish larvae were infected did the mutant produce less mortality than the wild type. Variations between models were evidenced using the AH-1∆rmlB, which lacks the O-antigen lipopolysaccharide (LPS, and the AH-1∆wahD, which lacks the O-antigen LPS and part of the LPS outer-core. Both mutants showed decreased mortality in all of the animal models, but the differences between them were only observed in injured zebrafish larvae, suggesting that residues from the LPS outer core must be important for virulence. The greatest differences were observed using the AH-1ΔFlaB-J (lacking polar flagella and unable to swim and the AH-1::motX (non-motile but producing flagella. They were as pathogenic as the wild-type strain when injected into mice and trout, but no mortalities were registered in zebrafish larvae. This study

  3. Health literacy in Europe: comparative results of the European health literacy survey (HLS-EU).

    Science.gov (United States)

    Sørensen, Kristine; Pelikan, Jürgen M; Röthlin, Florian; Ganahl, Kristin; Slonska, Zofia; Doyle, Gerardine; Fullam, James; Kondilis, Barbara; Agrafiotis, Demosthenes; Uiters, Ellen; Falcon, Maria; Mensing, Monika; Tchamov, Kancho; van den Broucke, Stephan; Brand, Helmut

    2015-12-01

    Health literacy concerns the capacities of people to meet the complex demands of health in modern society. In spite of the growing attention for the concept among European health policymakers, researchers and practitioners, information about the status of health literacy in Europe remains scarce. This article presents selected findings from the first European comparative survey on health literacy in populations. The European health literacy survey (HLS-EU) was conducted in eight countries: Austria, Bulgaria, Germany, Greece, Ireland, the Netherlands, Poland and Spain (n = 1000 per country, n = 8000 total sample). Data collection was based on Eurobarometer standards and the implementation of the HLS-EU-Q (questionnaire) in computer-assisted or paper-assisted personal interviews. The HLS-EU-Q constructed four levels of health literacy: insufficient, problematic, sufficient and excellent. At least 1 in 10 (12%) respondents showed insufficient health literacy and almost 1 in 2 (47%) had limited (insufficient or problematic) health literacy. However, the distribution of levels differed substantially across countries (29-62%). Subgroups within the population, defined by financial deprivation, low social status, low education or old age, had higher proportions of people with limited health literacy, suggesting the presence of a social gradient which was also confirmed by raw bivariate correlations and a multivariate linear regression model. Limited health literacy represents an important challenge for health policies and practices across Europe, but to a different degree for different countries. The social gradient in health literacy must be taken into account when developing public health strategies to improve health equity in Europe. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association.

  4. Microbial comparative pan-genomics using binomial mixture models

    Directory of Open Access Journals (Sweden)

    Ussery David W

    2009-08-01

    Full Text Available Abstract Background The size of the core- and pan-genome of bacterial species is a topic of increasing interest due to the growing number of sequenced prokaryote genomes, many from the same species. Attempts to estimate these quantities have been made, using regression methods or mixture models. We extend the latter approach by using statistical ideas developed for capture-recapture problems in ecology and epidemiology. Results We estimate core- and pan-genome sizes for 16 different bacterial species. The results reveal a complex dependency structure for most species, manifested as heterogeneous detection probabilities. Estimated pan-genome sizes range from small (around 2600 gene families in Buchnera aphidicola to large (around 43000 gene families in Escherichia coli. Results for Echerichia coli show that as more data become available, a larger diversity is estimated, indicating an extensive pool of rarely occurring genes in the population. Conclusion Analyzing pan-genomics data with binomial mixture models is a way to handle dependencies between genomes, which we find is always present. A bottleneck in the estimation procedure is the annotation of rarely occurring genes.

  5. Comparing predictive models of glioblastoma multiforme built using multi-institutional and local data sources.

    Science.gov (United States)

    Singleton, Kyle W; Hsu, William; Bui, Alex A T

    2012-01-01

    The growing amount of electronic data collected from patient care and clinical trials is motivating the creation of national repositories where multiple institutions share data about their patient cohorts. Such efforts aim to provide sufficient sample sizes for data mining and predictive modeling, ultimately improving treatment recommendations and patient outcome prediction. While these repositories offer the potential to improve our understanding of a disease, potential issues need to be addressed to ensure that multi-site data and resultant predictive models are useful to non-contributing institutions. In this paper we examine the challenges of utilizing National Cancer Institute datasets for modeling glioblastoma multiforme. We created several types of prognostic models and compared their results against models generated using data solely from our institution. While overall model performance between the data sources was similar, different variables were selected during model generation, suggesting that mapping data resources between models is not a straightforward issue.

  6. Fuel assembly bow: analytical modeling and resulting design improvements

    International Nuclear Information System (INIS)

    Stabel, J.; Huebsch, H.P.

    1995-01-01

    The bowing of fuel assemblies may result in a contact between neighbouring fuel assemblies and in connection with a vibration to a resulting wear or even perforation at the corners of the spacer grids of neighbouring assemblies. Such events allowed reinsertion of a few fuel assemblies in Germany only after spacer repair. In order to identify the most sensitive parameters causing the observed bowing of fuel assemblies a new computer model was develop which takes into a account the highly nonlinear behaviour of the interaction between fuel rods and spacers. As a result of the studies performed with this model, design improvements such as a more rigid connection between guide thimbles and spacer grids, could be defined. First experiences with this improved design show significantly better fuel behaviour. (author). 5 figs., 1 tabs

  7. Static response of deformable microchannels: a comparative modelling study

    Science.gov (United States)

    Shidhore, Tanmay C.; Christov, Ivan C.

    2018-02-01

    We present a comparative modelling study of fluid–structure interactions in microchannels. Through a mathematical analysis based on plate theory and the lubrication approximation for low-Reynolds-number flow, we derive models for the flow rate-pressure drop relation for long shallow microchannels with both thin and thick deformable top walls. These relations are tested against full three-dimensional two-way-coupled fluid–structure interaction simulations. Three types of microchannels, representing different elasticity regimes and having been experimentally characterized previously, are chosen as benchmarks for our theory and simulations. Good agreement is found in most cases for the predicted, simulated and measured flow rate-pressure drop relationships. The numerical simulations performed allow us to also carefully examine the deformation profile of the top wall of the microchannel in any cross section, showing good agreement with the theory. Specifically, the prediction that span-wise displacement in a long shallow microchannel decouples from the flow-wise deformation is confirmed, and the predicted scaling of the maximum displacement with the hydrodynamic pressure and the various material and geometric parameters is validated.

  8. Comparative analyses reveal discrepancies among results of commonly used methods for Anopheles gambiaemolecular form identification

    Directory of Open Access Journals (Sweden)

    Pinto João

    2011-08-01

    Full Text Available Abstract Background Anopheles gambiae M and S molecular forms, the major malaria vectors in the Afro-tropical region, are ongoing a process of ecological diversification and adaptive lineage splitting, which is affecting malaria transmission and vector control strategies in West Africa. These two incipient species are defined on the basis of single nucleotide differences in the IGS and ITS regions of multicopy rDNA located on the X-chromosome. A number of PCR and PCR-RFLP approaches based on form-specific SNPs in the IGS region are used for M and S identification. Moreover, a PCR-method to detect the M-specific insertion of a short interspersed transposable element (SINE200 has recently been introduced as an alternative identification approach. However, a large-scale comparative analysis of four widely used PCR or PCR-RFLP genotyping methods for M and S identification was never carried out to evaluate whether they could be used interchangeably, as commonly assumed. Results The genotyping of more than 400 A. gambiae specimens from nine African countries, and the sequencing of the IGS-amplicon of 115 of them, highlighted discrepancies among results obtained by the different approaches due to different kinds of biases, which may result in an overestimation of MS putative hybrids, as follows: i incorrect match of M and S specific primers used in the allele specific-PCR approach; ii presence of polymorphisms in the recognition sequence of restriction enzymes used in the PCR-RFLP approaches; iii incomplete cleavage during the restriction reactions; iv presence of different copy numbers of M and S-specific IGS-arrays in single individuals in areas of secondary contact between the two forms. Conclusions The results reveal that the PCR and PCR-RFLP approaches most commonly utilized to identify A. gambiae M and S forms are not fully interchangeable as usually assumed, and highlight limits of the actual definition of the two molecular forms, which might

  9. Methodology and Results of Mathematical Modelling of Complex Technological Processes

    Science.gov (United States)

    Mokrova, Nataliya V.

    2018-03-01

    The methodology of system analysis allows us to draw a mathematical model of the complex technological process. The mathematical description of the plasma-chemical process was proposed. The importance the quenching rate and initial temperature decrease time was confirmed for producing the maximum amount of the target product. The results of numerical integration of the system of differential equations can be used to describe reagent concentrations, plasma jet rate and temperature in order to achieve optimal mode of hardening. Such models are applicable both for solving control problems and predicting future states of sophisticated technological systems.

  10. Modeling vertical loads in pools resulting from fluid injection. [BWR

    Energy Technology Data Exchange (ETDEWEB)

    Lai, W.; McCauley, E.W.

    1978-06-15

    Table-top model experiments were performed to investigate pressure suppression pool dynamics effects due to a postulated loss-of-coolant accident (LOCA) for the Peachbottom Mark I boiling water reactor containment system. The results guided subsequent conduct of experiments in the /sup 1///sub 5/-scale facility and provided new insight into the vertical load function (VLF). Model experiments show an oscillatory VLF with the download typically double-spiked followed by a more gradual sinusoidal upload. The load function contains a high frequency oscillation superimposed on a low frequency one; evidence from measurements indicates that the oscillations are initiated by fluid dynamics phenomena.

  11. Modeling vertical loads in pools resulting from fluid injection

    International Nuclear Information System (INIS)

    Lai, W.; McCauley, E.W.

    1978-01-01

    Table-top model experiments were performed to investigate pressure suppression pool dynamics effects due to a postulated loss-of-coolant accident (LOCA) for the Peachbottom Mark I boiling water reactor containment system. The results guided subsequent conduct of experiments in the 1 / 5 -scale facility and provided new insight into the vertical load function (VLF). Model experiments show an oscillatory VLF with the download typically double-spiked followed by a more gradual sinusoidal upload. The load function contains a high frequency oscillation superimposed on a low frequency one; evidence from measurements indicates that the oscillations are initiated by fluid dynamics phenomena

  12. Some results on the dynamics generated by the Bazykin model

    Directory of Open Access Journals (Sweden)

    Georgescu, R M

    2006-07-01

    Full Text Available A predator-prey model formerly proposed by A. Bazykin et al. [Bifurcation diagrams of planar dynamical systems (1985] is analyzed in the case when two of the four parameters are kept fixed. Dynamics and bifurcation results are deduced by using the methods developed by D. K. Arrowsmith and C. M. Place [Ordinary differential equations (1982], S.-N. Chow et al. [Normal forms and bifurcation of planar fields (1994], Y. A. Kuznetsov [Elements of applied bifurcation theory (1998], and A. Georgescu [Dynamic bifurcation diagrams for some models in economics and biology (2004]. The global dynamic bifurcation diagram is constructed and graphically represented. The biological interpretation is presented, too.

  13. Comparing results of clinical versus ultrasonographic examination in developmental dysplasia of hip

    Directory of Open Access Journals (Sweden)

    Hamidreza Arti

    2013-01-01

    Full Text Available Background: Developmental dysplasia of hip (DDH is one of the congenital anomalies in newborns that if not diagnosed and treated on time can lead to a severe disability. Although clinical examination is a very useful way for screening, but in some patients, a confirmatory diagnostic method such as ultrasonography is needed. The aim of the present study is to compare the sensitivity and specificity of clinical examination and ultrasonography in early detecting of DDH. Materials and Methods: A total of 5800 of newborns were examined by orthopedic surgeon as a screening method. The newborns with risk factors or suspicious on clinical examination were introduced to repeat clinical and ultrasonographic examination of hip. The results were collected and recorded by a check list and then the sensitivity and specificity of clinical examination were calculated. Results: Of 5701 newborns (11402 hips who were studied by two methods of clinical examination and ultrasonography (by Graf method, the overall incidence of DDH was 29 per 1000. Only 94 hips (13.5% of 694 disordered ones according to clinical examination were involved on ultrasonographic evaluation. A total of 240 hips of 334 (72% involved hips according to ultrasonography (Graf type IIb or more were diagnosed normal on clinical examination, considering ultrasonography as a gold standard method of evaluating DDH, the sensitivity and specificity of clinical examination were calculated 28.1% and 94.5%, respectively. Conclusion: According to the present study, ultrasonogeraphic examination has a high valuable in screening of DDH and the clinical examination done by an experienced orthopedic surgeon has an acceptable value in primary screening of DDH in developing countries for detecting of healthy neonates, but if the newborn has a risk factor or is suspicious on clinical examination, it will be necessary to get assistance from ultrasonography by an experienced sonographer.

  14. MR elastography of liver fibrosis: preliminary results comparing spin-echo and echo-planar imaging

    Energy Technology Data Exchange (ETDEWEB)

    Huwart, Laurent; Salameh, Najat; Peeters, Frank; Beers, Bernard E. van [Universite Catholique de Louvain, St-Luc University Hospital, Diagnostic Radiology Unit, Brussels (Belgium); Beek, Leon ter [Philips Medical Systems, Best (Netherlands); Vicaut, Eric [Universite Paris Diderot, Hopital Lariboisiere, Paris (France); Sinkus, Ralph [Universite Paris Diderot, Laboratoire Ondes et Acoustique, Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris, Paris (France)

    2008-11-15

    The purpose of this study was to prospectively compare the performance of magnetic resonance (MR) elastography using echo-planar and spin-echo imaging for staging of hepatic fibrosis. Twenty-four patients who had liver biopsy for suspicion of chronic liver disease had MR elastography performed with both spin-echo and echo-planar sequences. At histology, the fibrosis stage was assessed according to METAVIR. The data acquisition time was about 20 min using spin-echo, and only 2 min using echo-planar imaging. The hepatic signal-to-noise ratios were similar on both images (22.51 {+-} 5.37 for spin-echo versus 21.02 {+-} 4.76 for echo-planar, p = 0.33). The elasticity measurements and the fibrosis stages were strongly correlated. The Spearman correlation coefficients were r = 0.91 (p < 0.01) with spin-echo and r = 0.84 (p < 0.01) with echo-planar sequences. These correlation coefficients did not differ significantly (p = 0.17). A strong correlation was also observed between spin-echo and echo-planar elasticity (r = 0.83, p < 0.001), without systematic bias. The results of our study showed that echo-planar imaging substantially decreased the data acquisition time of MR elastography, while maintaining the image quality and diagnostic performance for staging of liver fibrosis. This suggests that echo-planar MR elastography could replace spin-echo MR elastography in clinical practice. (orig.)

  15. Achieving interoperability for metadata registries using comparative object modeling.

    Science.gov (United States)

    Park, Yu Rang; Kim, Ju Han

    2010-01-01

    Achieving data interoperability between organizations relies upon agreed meaning and representation (metadata) of data. For managing and registering metadata, many organizations have built metadata registries (MDRs) in various domains based on international standard for MDR framework, ISO/IEC 11179. Following this trend, two pubic MDRs in biomedical domain have been created, United States Health Information Knowledgebase (USHIK) and cancer Data Standards Registry and Repository (caDSR), from U.S. Department of Health & Human Services and National Cancer Institute (NCI), respectively. Most MDRs are implemented with indiscriminate extending for satisfying organization-specific needs and solving semantic and structural limitation of ISO/IEC 11179. As a result it is difficult to address interoperability among multiple MDRs. In this paper, we propose an integrated metadata object model for achieving interoperability among multiple MDRs. To evaluate this model, we developed an XML Schema Definition (XSD)-based metadata exchange format. We created an XSD-based metadata exporter, supporting both the integrated metadata object model and organization-specific MDR formats.

  16. Initial CGE Model Results Summary Exogenous and Endogenous Variables Tests

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Brian Keith [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Boero, Riccardo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rivera, Michael Kelly [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-07

    The following discussion presents initial results of tests of the most recent version of the National Infrastructure Simulation and Analysis Center Dynamic Computable General Equilibrium (CGE) model developed by Los Alamos National Laboratory (LANL). The intent of this is to test and assess the model’s behavioral properties. The test evaluated whether the predicted impacts are reasonable from a qualitative perspective. This issue is whether the predicted change, be it an increase or decrease in other model variables, is consistent with prior economic intuition and expectations about the predicted change. One of the purposes of this effort is to determine whether model changes are needed in order to improve its behavior qualitatively and quantitatively.

  17. The European COPHES/DEMOCOPHES project: towards transnational comparability and reliability of human biomonitoring results.

    Science.gov (United States)

    Schindler, Birgit Karin; Esteban, Marta; Koch, Holger Martin; Castano, Argelia; Koslitz, Stephan; Cañas, Ana; Casteleyn, Ludwine; Kolossa-Gehring, Marike; Schwedler, Gerda; Schoeters, Greet; Hond, Elly Den; Sepai, Ovnair; Exley, Karen; Bloemen, Louis; Horvat, Milena; Knudsen, Lisbeth E; Joas, Anke; Joas, Reinhard; Biot, Pierre; Aerts, Dominique; Lopez, Ana; Huetos, Olga; Katsonouri, Andromachi; Maurer-Chronakis, Katja; Kasparova, Lucie; Vrbík, Karel; Rudnai, Peter; Naray, Miklos; Guignard, Cedric; Fischer, Marc E; Ligocka, Danuta; Janasik, Beata; Reis, M Fátima; Namorado, Sónia; Pop, Cristian; Dumitrascu, Irina; Halzlova, Katarina; Fabianova, Eleonora; Mazej, Darja; Tratnik, Janja Snoj; Berglund, Marika; Jönsson, Bo; Lehmann, Andrea; Crettaz, Pierre; Frederiksen, Hanne; Nielsen, Flemming; McGrath, Helena; Nesbitt, Ian; De Cremer, Koen; Vanermen, Guido; Koppen, Gudrun; Wilhelm, Michael; Becker, Kerstin; Angerer, Jürgen

    2014-07-01

    COPHES/DEMOCOPHES has its origins in the European Environment and Health Action Plan of 2004 to "develop a coherent approach on human biomonitoring (HBM) in Europe". Within this twin-project it was targeted to collect specimens from 120 mother-child-pairs in each of the 17 participating European countries. These specimens were investigated for six biomarkers (mercury in hair; creatinine, cotinine, cadmium, phthalate metabolites and bisphenol A in urine). The results for mercury in hair are described in a separate paper. Each participating member state was requested to contract laboratories, for capacity building reasons ideally within its borders, carrying out the chemical analyses. To ensure comparability of analytical data a Quality Assurance Unit (QAU) was established which provided the participating laboratories with standard operating procedures (SOP) and with control material. This material was specially prepared from native, non-spiked, pooled urine samples and was tested for homogeneity and stability. Four external quality assessment exercises were carried out. Highly esteemed laboratories from all over the world served as reference laboratories. Web conferences after each external quality assessment exercise functioned as a new and effective tool to improve analytical performance, to build capacity and to educate less experienced laboratories. Of the 38 laboratories participating in the quality assurance exercises 14 laboratories qualified for cadmium, 14 for creatinine, 9 for cotinine, 7 for phthalate metabolites and 5 for bisphenol A in urine. In the last of the four external quality assessment exercises the laboratories that qualified for DEMOCOPHES performed the determinations in urine with relative standard deviations (low/high concentration) of 18.0/2.1% for cotinine, 14.8/5.1% for cadmium, 4.7/3.4% for creatinine. Relative standard deviations for the newly emerging biomarkers were higher, with values between 13.5 and 20.5% for bisphenol A and

  18. The comparing results of carcinoma between three-phase and delayed whole body bone scan

    International Nuclear Information System (INIS)

    Si Hongwei; Li Xianfeng

    2004-01-01

    Purpose: Three phase bone scan is an imaging technology in nuclear medicine, which composed of blood flow phase, blood pool phase and delayed phase and the last one is often performed in routine works in department of nuclear medicine. The purpose of this study is to evaluate the merit of three-phase bone scan.Methods: In this study, we chose 54 patients who were having an regional pain which caused by benign or malignant carcinoma that diagnosed by CT, X-ray, ECT, MRI or other examinations. The imaging were acquired simultaneously from both anterior and posterior views, after a bolus injection of 1110 MBq technetium-99m-labelled methylene diphosphonate (MDP), blood phase contains 20 frame sand 3 seconds per frame, blood pool phase contains 5 frames and 1 minute per frame, delayed phase was performed 2.5 hour later. According to the results of three-phase bone scan, the patients were divided into 2 groups: normal and abnormal groups. The abnormal group includes early phase positive,delay positive and all three phase positive sets. The comparing among the 3 sets were analyzed by chi-square test and other statistic means.Results: There were 54 patients who had suffered lung cancer, breast cancer and other cancer,involved in this study, 34 males and 20 females, ranged age 17 to 88 years, were normal in 15 cases,positive in 22 cases, the results in delayed phase were positive in 9 cases, blood flow and blood pool phase showed blood flow changes in 4 cases and soft tissue tumors were seen in 4 cases. Three phase bone scan was more sensitive than delayed whole body bone scan in detecting the abnormal sites (p 0.05) The sensitivity of detecting tumors in blood flow and blood pool phase,delayed phase were respectively lower than in three phase bone scan (p<0.001).Conclusion: It is more sensitivity of detecting tumor lesions in three phase bone scan than in delayed phase whole body bone scan and the changes of blood flow and soft tissue can be seen in three phase bone scan

  19. Comparing gender awareness in Dutch and Swedish first-year medical students - results from a questionaire

    Directory of Open Access Journals (Sweden)

    Andersson Jenny

    2012-01-01

    Full Text Available Abstract Background To ascertain good and appropriate healthcare for both women and men implementation of gender perspectives in medical education is needed. For a successful implementation, knowledge about students' attitudes and beliefs about men, women, and gender is crucial. The aim of this study was to compare attitudes to gender and gender stereotyping among Dutch and Swedish male and female medical students. Methods In this cross-sectional study, we measured the attitudes and assumptions about gender among 1096 first year medical students (616 Dutch and 480 Swedish with the validated Nijmegen Gender Awareness in Medicine Scale (N-GAMS. The response rate was 94% in the Netherlands and 93% in Sweden. Univariate analysis of variance (ANOVA was used to compare the scores between Dutch and Swedish male and female students. Linear regressions were used to analyze the importance of the background variables. Results There were significant differences in attitudes to gender between Dutch and Swedish students. The Swedish students expressed less stereotypical thinking about patients and doctors and the Dutch were more sensitive to gender differences. The students' sex mattered for gender stereotyping, with male students in both countries agreeing more with stereotypical statements. Students' age, father's birth country and mother's education level had some impact on the outcome. Conclusions There are differences between cultures as well as between men and women in gender awareness that need to be considered when implementing gender in medical education. This study suggests that to arouse the students' interest in gender issues and make them aware of the significance of gender in medical work, the examples used in discussions need to be relevant and challenging in the context of the specific country. Due to different levels of knowledge and different attitudes within the student population it is important to create a climate for dialogue where

  20. Comparative Evaluation of Some Crop Yield Prediction Models ...

    African Journals Online (AJOL)

    A computer program was adopted from the work of Hill et al. (1982) to calibrate and test three of the existing yield prediction models using tropical cowpea yieldÐweather data. The models tested were Hanks Model (first and second versions). Stewart Model (first and second versions) and HallÐButcher Model. Three sets of ...

  1. Comparative Evaluation of Some Crop Yield Prediction Models ...

    African Journals Online (AJOL)

    (1982) to calibrate and test three of the existing yield prediction models using tropical cowpea yieldÐweather data. The models tested were Hanks Model (first and second versions). Stewart Model (first and second versions) and HallÐButcher Model. Three sets of cowpea yield-water use and weather data were collected.

  2. Interaction between subducting plates: results from numerical and analogue modeling

    Science.gov (United States)

    Kiraly, Agnes; Capitanio, Fabio A.; Funiciello, Francesca; Faccenna, Claudio

    2016-04-01

    The tectonic setting of the Alpine-Mediterranean area is achieved during the late Cenozoic subduction, collision and suturing of several oceanic fragments and continental blocks. In this stage, processes such as interactions among subducting slabs, slab migrations and related mantle flow played a relevant role on the resulting tectonics. Here, we use numerical models to first address the mantle flow characteristic in 3D. During the subduction of a single plate the strength of the return flow strongly depends on the slab pull force, that is on the plate's buoyancy, however the physical properties of the slab, such as density, viscosity or width, do not affect largely the morphology of the toroidal cell. Instead, dramatic effects on the geometry and the dynamics of the toroidal cell result in models where the thickness of the mantle is varied. The vertical component of the vorticity vector is used to define the characteristic size of the toroidal cell, which is ~1.2-1.3 times the mantle depth. This latter defines the range of viscous stress propagation through the mantle and consequent interactions with other slabs. We thus further investigate on this setup where two separate lithospheric plates subduct in opposite sense, developing opposite polarities and convergent slab retreat, and model different initial sideways distance between the plates. The stress profiles in time illustrate that the plates interacts when slabs are at the characteristic distance and the two slabs toroidal cells merge. Increased stress and delayed slab migrations are the results. Analogue models of double-sided subduction show similar maximum distance and allow testing the additional role of stress propagated through the plates. We use a silicon plate subducting on its two opposite margins, which is either homogeneous or comprises oceanic and continental lithospheres, differing in buoyancy. The modeling results show that the double-sided subduction is strongly affected by changes in plate

  3. First experiments results about the engineering model of Rapsodie

    International Nuclear Information System (INIS)

    Chalot, A.; Ginier, R.; Sauvage, M.

    1964-01-01

    This report deals with the first series of experiments carried out on the engineering model of Rapsodie and on an associated sodium facility set in a laboratory hall of Cadarache. It conveys more precisely: 1/ - The difficulties encountered during the erection and assembly of the engineering model and a compilation of the results of the first series of experiments and tests carried out on this installation (loading of the subassemblies preheating, thermal chocks...). 2/ - The experiments and tests carried out on the two prototypes control rod drive mechanisms which brought to the choice for the design of the definitive drive mechanism. As a whole, the results proved the validity of the general design principles adopted for Rapsodie. (authors) [fr

  4. Workshop to transfer VELMA watershed model results to ...

    Science.gov (United States)

    An EPA Western Ecology Division (WED) watershed modeling team has been working with the Snoqualmie Tribe Environmental and Natural Resources Department to develop VELMA watershed model simulations of the effects of historical and future restoration and land use practices on streamflow, stream temperature, and other habitat characteristics affecting threatened salmon populations in the 100 square mile Tolt River watershed in Washington state. To date, the WED group has fully calibrated the watershed model to simulate Tolt River flows with a high degree of accuracy under current and historical conditions and practices, and is in the process of simulating long-term responses to specific watershed restoration practices conducted by the Snoqualmie Tribe and partners. On July 20-21 WED Researchers Bob McKane, Allen Brookes and ORISE Fellow Jonathan Halama will be attending a workshop at the Tolt River site in Carnation, WA, to present and discuss modeling results with the Snoqualmie Tribe and other Tolt River watershed stakeholders and land managers, including the Washington Departments of Ecology and Natural Resources, U.S. Forest Service, City of Seattle, King County, and representatives of the Northwest Indian Fisheries Commission. The workshop is being co-organized by the Snoqualmie Tribe, EPA Region 10 and WED. The purpose of this 2-day workshop is two-fold. First, on Day 1, the modeling team will perform its second site visit to the watershed, this time focus

  5. Meteorological uncertainty of atmospheric dispersion model results (MUD)

    International Nuclear Information System (INIS)

    Havskov Soerensen, J.; Amstrup, B.; Feddersen, H.

    2013-08-01

    The MUD project addresses assessment of uncertainties of atmospheric dispersion model predictions, as well as possibilities for optimum presentation to decision makers. Previously, it has not been possible to estimate such uncertainties quantitatively, but merely to calculate the 'most likely' dispersion scenario. However, recent developments in numerical weather prediction (NWP) include probabilistic forecasting techniques, which can be utilised also for long-range atmospheric dispersion models. The ensemble statistical methods developed and applied to NWP models aim at describing the inherent uncertainties of the meteorological model results. These uncertainties stem from e.g. limits in meteorological observations used to initialise meteorological forecast series. By perturbing e.g. the initial state of an NWP model run in agreement with the available observational data, an ensemble of meteorological forecasts is produced from which uncertainties in the various meteorological parameters are estimated, e.g. probabilities for rain. Corresponding ensembles of atmospheric dispersion can now be computed from which uncertainties of predicted radionuclide concentration and deposition patterns can be derived. (Author)

  6. Some results on hyperscaling in the 3D Ising model

    Energy Technology Data Exchange (ETDEWEB)

    Baker, G.A. Jr. [Los Alamos National Lab., NM (United States). Theoretical Div.; Kawashima, Naoki [Univ. of Tokyo (Japan). Dept. of Physics

    1995-09-01

    The authors review exact studies on finite-sized 2 dimensional Ising models and show that the point for an infinite-sized model at the critical temperature is a point of nonuniform approach in the temperature-size plane. They also illuminate some strong effects of finite-size on quantities which do not diverge at the critical point. They then review Monte Carlo studies for 3 dimensional Ising models of various sizes (L = 2--100) at various temperatures. From these results they find that the data for the renormalized coupling constant collapses nicely when plotted against the correlation length, determined in a system of edge length L, divided by L. They also find that {zeta}{sub L}/L {ge} 0.26 is definitely too large for reliable studies of the critical value, g*, of the renormalized coupling constant. They have reasonable evidence that {zeta}{sub L}/L {approx} 0.1 is adequate for results that are within one percent of those for the infinite system size. On this basis, they have conducted a series of Monte Carlo calculations with this condition imposed. These calculations were made practical by the development of improved estimators for use in the Swendsen-Wang cluster method. The authors found from these results, coupled with a reversed limit computation (size increases with the temperature fixed at the critical temperature), that g* > 0, although there may well be a sharp downward drop in g as the critical temperature is approached in accord with the predictions of series analysis. The results support the validity of hyperscaling in the 3 dimensional Ising model.

  7. Presenting results of software model checker via debugging interface

    OpenAIRE

    Kohan, Tomáš

    2012-01-01

    Title: Presenting results of software model checker via debugging interface Author: Tomáš Kohan Department: Department of Software Engineering Supervisor of the master thesis: RNDr. Ondřej Šerý, Ph.D., Department of Distributed and Dependable Systems Abstract: This thesis is devoted to design and implementation of the new debugging interface of the Java PathFinder application. As a suitable inte- face container was selected the Eclipse development environment. The created interface should vis...

  8. Comparative Analysis of Behavioral Models for Adaptive Learning in Changing Environments.

    Science.gov (United States)

    Marković, Dimitrije; Kiebel, Stefan J

    2016-01-01

    Probabilistic models of decision making under various forms of uncertainty have been applied in recent years to numerous behavioral and model-based fMRI studies. These studies were highly successful in enabling a better understanding of behavior and delineating the functional properties of brain areas involved in decision making under uncertainty. However, as different studies considered different models of decision making under uncertainty, it is unclear which of these computational models provides the best account of the observed behavioral and neuroimaging data. This is an important issue, as not performing model comparison may tempt researchers to over-interpret results based on a single model. Here we describe how in practice one can compare different behavioral models and test the accuracy of model comparison and parameter estimation of Bayesian and maximum-likelihood based methods. We focus our analysis on two well-established hierarchical probabilistic models that aim at capturing the evolution of beliefs in changing environments: Hierarchical Gaussian Filters and Change Point Models. To our knowledge, these two, well-established models have never been compared on the same data. We demonstrate, using simulated behavioral experiments, that one can accurately disambiguate between these two models, and accurately infer free model parameters and hidden belief trajectories (e.g., posterior expectations, posterior uncertainties, and prediction errors) even when using noisy and highly correlated behavioral measurements. Importantly, we found several advantages of Bayesian inference and Bayesian model comparison compared to often-used Maximum-Likelihood schemes combined with the Bayesian Information Criterion. These results stress the relevance of Bayesian data analysis for model-based neuroimaging studies that investigate human decision making under uncertainty.

  9. [Comparative analysis of conventional pulmonary function test results in children with asthma or cough variant asthma].

    Science.gov (United States)

    Yuan, Jie; An, Shu-Hua; Gao, Wen-Jie; Du, Wen-Jin; Sun, Jun-Feng; Zhang, Man; Yao, Cong-Zhuo

    2013-03-01

    To compare the conventional pulmonary function test results of children with asthma or cough variant asthma (CVA). A total of 140 children, who were diagnosed with asthma or CVA from May 2010 to May 2011, were divided into acute asthma attack (n=50), asthma remission (n=50) and CVA groups (n=40); 30 healthy children were included as a control group. The forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), forced expiratory flow after 25% of vital capacity has been expelled (FEF25), forced expiratory flow after 50% of vital capacity has been expelled (FEF50), forced expiratory flow after 75% of vital capacity has been expelled (FEF75) and maximal midexpiratory flow (MMEF75/25) were measured. The mean percent predicted values of all the above indices were lower than 80% in the acute asthma attack group, with FEF50, FEF75 and MMEF75/25 declining markedly; the mean percent predicted values of FEF75 and MMEF75/25 were lower than 80% in the CVA group. All the pulmonary function indices in the acute asthma attack group were lower than those in the control group. The mean percent predicted values of FVC, FEV1, FEF25 and MMEF75/25 in the asthma remission and CVA groups were lower than in the control group. All the pulmonary function indices in the acute asthma attack group were lower than in the asthma remission and CVA groups, but there were no significant differences between the asthma remission and CVA groups. There is small and large airway dysfunction, particularly small airway dysfunction, in children with acute asthma attack. Children with CVA present mainly with mild small airway dysfunction, as do those with asthma in remission.

  10. Review of Current Standard Model Results in ATLAS

    CERN Document Server

    Brandt, Gerhard; The ATLAS collaboration

    2018-01-01

    This talk highlights results selected from the Standard Model research programme of the ATLAS Collaboration at the Large Hadron Collider. Results using data from $p-p$ collisions at $\\sqrt{s}=7,8$~TeV in LHC Run-1 as well as results using data at $\\sqrt{s}=13$~TeV in LHC Run-2 are covered. The status of cross section measurements from soft QCD processes and jet production as well as photon production are presented. The presentation extends to vector boson production with associated jets. Precision measurements of the production of $W$ and $Z$ bosons, including a first measurement of the mass of the $W$ bosons, $m_W$, are discussed. The programme to measure electroweak processes with di-boson and tri-boson final states is outlined. All presented measurements are compatible with Standard Model descriptions and allow to further constrain it. In addition they allow to probe new physics which would manifest through extra gauge couplings, or Standard Model gauge couplings deviating from their predicted value.

  11. Flexible Survival Strategies of Pseudomonas aeruginosa in Biofilms Result in Increased Fitness Compared with Candida albicans *

    Science.gov (United States)

    Purschke, Frauke Gina; Hiller, Ekkehard; Trick, Iris; Rupp, Steffen

    2012-01-01

    The majority of microorganisms persist in nature as surface-attached communities often surrounded by an extracellular matrix, called biofilms. Most natural biofilms are not formed by a single species but by multiple species. Microorganisms not only cooperate as in some multispecies biofilms but also compete for available nutrients. The Gram-negative bacterium Pseudomonas aeruginosa and the polymorphic fungus Candida albicans are two opportunistic pathogens that are often found coexisting in a human host. Several models of mixed biofilms have been reported for these organisms showing antagonistic behavior. To investigate the interaction of P. aeruginosa and C. albicans in more detail, we analyzed the secretome of single and mixed biofilms of both organisms using MALDI-TOF MS/MS at several time points. Overall 247 individual proteins were identified, 170 originated from P. aeruginosa and 77 from C. albicans. Only 39 of the 131 in mixed biofilms identified proteins were assigned to the fungus whereby the remaining 92 proteins belonged to P. aeruginosa. In single-species biofilms, both organisms showed a higher diversity of proteins with 73 being assigned to C. albicans and 154 to P. aeruginosa. Most interestingly, P. aeruginosa in the presence of C. albicans secreted 16 proteins in significantly higher amounts or exclusively among other virulence factors such as exotoxin A and iron acquisition systems. In addition, the high affinity iron-binding siderophore pyoverdine was identified in mixed biofilms but not in bacterial biofilms, indicating that P. aeruginosa increases its capability to sequester iron in competition with C. albicans. In contrast, C. albicans metabolism was significantly reduced, including a reduction in detectable iron acquisition proteins. The results obtained in this study show that microorganisms not only compete with the host for essential nutrients but also strongly with the present microflora in order to gain a competitive advantage. PMID

  12. Comparative study of boron transport models in NRC Thermal-Hydraulic Code Trace

    Energy Technology Data Exchange (ETDEWEB)

    Olmo-Juan, Nicolás; Barrachina, Teresa; Miró, Rafael; Verdú, Gumersindo; Pereira, Claubia, E-mail: nioljua@iqn.upv.es, E-mail: tbarrachina@iqn.upv.es, E-mail: rmiro@iqn.upv.es, E-mail: gverdu@iqn.upv.es, E-mail: claubia@nuclear.ufmg.br [Institute for Industrial, Radiophysical and Environmental Safety (ISIRYM). Universitat Politècnica de València (Spain); Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2017-07-01

    Recently, the interest in the study of various types of transients involving changes in the boron concentration inside the reactor, has led to an increase in the interest of developing and studying new models and tools that allow a correct study of boron transport. Therefore, a significant variety of different boron transport models and spatial difference schemes are available in the thermal-hydraulic codes, as TRACE. According to this interest, in this work it will be compared the results obtained using the different boron transport models implemented in the NRC thermal-hydraulic code TRACE. To do this, a set of models have been created using the different options and configurations that could have influence in boron transport. These models allow to reproduce a simple event of filling or emptying the boron concentration in a long pipe. Moreover, with the aim to compare the differences obtained when one-dimensional or three-dimensional components are chosen, it has modeled many different cases using only pipe components or a mix of pipe and vessel components. In addition, the influence of the void fraction in the boron transport has been studied and compared under close conditions to BWR commercial model. A final collection of the different cases and boron transport models are compared between them and those corresponding to the analytical solution provided by the Burgers equation. From this comparison, important conclusions are drawn that will be the basis of modeling the boron transport in TRACE adequately. (author)

  13. COMPAR

    International Nuclear Information System (INIS)

    Kuefner, K.

    1976-01-01

    COMPAR works on FORTRAN arrays with four indices: A = A(i,j,k,l) where, for each fixed k 0 ,l 0 , only the 'plane' [A(i,j,k 0 ,l 0 ), i = 1, isub(max), j = 1, jsub(max)] is held in fast memory. Given two arrays A, B of this type COMPAR has the capability to 1) re-norm A and B ind different ways; 2) calculate the deviations epsilon defined as epsilon(i,j,k,l): =[A(i,j,k,l) - B(i,j,k,l)] / GEW(i,j,k,l) where GEW (i,j,k,l) may be chosen in three different ways; 3) calculate mean, standard deviation and maximum in the array epsilon (by several intermediate stages); 4) determine traverses in the array epsilon; 5) plot these traverses by a printer; 6) simplify plots of these traverses by the PLOTEASY-system by creating input data blocks for this system. The main application of COMPAR is given (so far) by the comparison of two- and three-dimensional multigroup neutron flux-fields. (orig.) [de

  14. Comparative nonlinear modeling of renal autoregulation in rats: Volterra approach versus artificial neural networks

    DEFF Research Database (Denmark)

    Chon, K H; Holstein-Rathlou, N H; Marsh, D J

    1998-01-01

    In this paper, feedforward neural networks with two types of activation functions (sigmoidal and polynomial) are utilized for modeling the nonlinear dynamic relation between renal blood pressure and flow data, and their performance is compared to Volterra models obtained by use of the leading...... kernel estimation method based on Laguerre expansions. The results for the two types of artificial neural networks and the Volterra models are comparable in terms of normalized mean square error (NMSE) of the respective output prediction for independent testing data. However, the Volterra models obtained...... via the Laguerre expansion technique achieve this prediction NMSE with approximately half the number of free parameters relative to either neural-network model. However, both approaches are deemed effective in modeling nonlinear dynamic systems and their cooperative use is recommended in general....

  15. Comparative systems biology between human and animal models based on next-generation sequencing methods.

    Science.gov (United States)

    Zhao, Yu-Qi; Li, Gong-Hua; Huang, Jing-Fei

    2013-04-01

    Animal models provide myriad benefits to both experimental and clinical research. Unfortunately, in many situations, they fall short of expected results or provide contradictory results. In part, this can be the result of traditional molecular biological approaches that are relatively inefficient in elucidating underlying molecular mechanism. To improve the efficacy of animal models, a technological breakthrough is required. The growing availability and application of the high-throughput methods make systematic comparisons between human and animal models easier to perform. In the present study, we introduce the concept of the comparative systems biology, which we define as "comparisons of biological systems in different states or species used to achieve an integrated understanding of life forms with all their characteristic complexity of interactions at multiple levels". Furthermore, we discuss the applications of RNA-seq and ChIP-seq technologies to comparative systems biology between human and animal models and assess the potential applications for this approach in the future studies.

  16. Challenges in validating model results for first year ice

    Science.gov (United States)

    Melsom, Arne; Eastwood, Steinar; Xie, Jiping; Aaboe, Signe; Bertino, Laurent

    2017-04-01

    In order to assess the quality of model results for the distribution of first year ice, a comparison with a product based on observations from satellite-borne instruments has been performed. Such a comparison is not straightforward due to the contrasting algorithms that are used in the model product and the remote sensing product. The implementation of the validation is discussed in light of the differences between this set of products, and validation results are presented. The model product is the daily updated 10-day forecast from the Arctic Monitoring and Forecasting Centre in CMEMS. The forecasts are produced with the assimilative ocean prediction system TOPAZ. Presently, observations of sea ice concentration and sea ice drift are introduced in the assimilation step, but data for sea ice thickness and ice age (or roughness) are not included. The model computes the age of the ice by recording and updating the time passed after ice formation as sea ice grows and deteriorates as it is advected inside the model domain. Ice that is younger than 365 days is classified as first year ice. The fraction of first-year ice is recorded as a tracer in each grid cell. The Ocean and Sea Ice Thematic Assembly Centre in CMEMS redistributes a daily product from the EUMETSAT OSI SAF of gridded sea ice conditions which include "ice type", a representation of the separation of regions between those infested by first year ice, and those infested by multi-year ice. The ice type is parameterized based on data for the gradient ratio GR(19,37) from SSMIS observations, and from the ASCAT backscatter parameter. This product also includes information on ambiguity in the processing of the remote sensing data, and the product's confidence level, which have a strong seasonal dependency.

  17. `Dem DEMs: Comparing Methods of Digital Elevation Model Creation

    Science.gov (United States)

    Rezza, C.; Phillips, C. B.; Cable, M. L.

    2017-12-01

    Topographic details of Europa's surface yield implications for large-scale processes that occur on the moon, including surface strength, modification, composition, and formation mechanisms for geologic features. In addition, small scale details presented from this data are imperative for future exploration of Europa's surface, such as by a potential Europa Lander mission. A comparison of different methods of Digital Elevation Model (DEM) creation and variations between them can help us quantify the relative accuracy of each model and improve our understanding of Europa's surface. In this work, we used data provided by Phillips et al. (2013, AGU Fall meeting, abs. P34A-1846) and Schenk and Nimmo (2017, in prep.) to compare DEMs that were created using Ames Stereo Pipeline (ASP), SOCET SET, and Paul Schenk's own method. We began by locating areas of the surface with multiple overlapping DEMs, and our initial comparisons were performed near the craters Manannan, Pwyll, and Cilix. For each region, we used ArcGIS to draw profile lines across matching features to determine elevation. Some of the DEMs had vertical or skewed offsets, and thus had to be corrected. The vertical corrections were applied by adding or subtracting the global minimum of the data set to create a common zero-point. The skewed data sets were corrected by rotating the plot so that it had a global slope of zero and then subtracting for a zero-point vertical offset. Once corrections were made, we plotted the three methods on one graph for each profile of each region. Upon analysis, we found relatively good feature correlation between the three methods. The smoothness of a DEM depends on both the input set of images and the stereo processing methods used. In our comparison, the DEMs produced by SOCET SET were less smoothed than those from ASP or Schenk. Height comparisons show that ASP and Schenk's model appear similar, alternating in maximum height. SOCET SET has more topographic variability due to its

  18. The utility of comparative models and the local model quality for protein crystal structure determination by Molecular Replacement

    Directory of Open Access Journals (Sweden)

    Pawlowski Marcin

    2012-11-01

    Full Text Available Abstract Background Computational models of protein structures were proved to be useful as search models in Molecular Replacement (MR, a common method to solve the phase problem faced by macromolecular crystallography. The success of MR depends on the accuracy of a search model. Unfortunately, this parameter remains unknown until the final structure of the target protein is determined. During the last few years, several Model Quality Assessment Programs (MQAPs that predict the local accuracy of theoretical models have been developed. In this article, we analyze whether the application of MQAPs improves the utility of theoretical models in MR. Results For our dataset of 615 search models, the real local accuracy of a model increases the MR success ratio by 101% compared to corresponding polyalanine templates. On the contrary, when local model quality is not utilized in MR, the computational models solved only 4.5% more MR searches than polyalanine templates. For the same dataset of the 615 models, a workflow combining MR with predicted local accuracy of a model found 45% more correct solution than polyalanine templates. To predict such accuracy MetaMQAPclust, a “clustering MQAP” was used. Conclusions Using comparative models only marginally increases the MR success ratio in comparison to polyalanine structures of templates. However, the situation changes dramatically once comparative models are used together with their predicted local accuracy. A new functionality was added to the GeneSilico Fold Prediction Metaserver in order to build models that are more useful for MR searches. Additionally, we have developed a simple method, AmIgoMR (Am I good for MR?, to predict if an MR search with a template-based model for a given template is likely to find the correct solution.

  19. Comparing Entrepreneurship Intention: A Multigroup Structural Equation Modeling Approach

    Directory of Open Access Journals (Sweden)

    Sabrina O. Sihombing

    2012-04-01

    Full Text Available Unemployment is one of the main social and economic problems that many countries face nowadays. One strategic way to overcome this problem is by fostering entrepreneurship spirit especially for unem-ployment graduates. Entrepreneurship is becoming an alternative Job for students after they graduate. This is because entrepreneurship of fers major benefits, such as setting up one’s own business and the pos sibility of having significant financial rewards than working for others. Entrepreneurship is then offered by many universities. This research applies the theory of planned behavior (TPB by incorporating attitude toward success as an antecedent variable of the attitude to examine students’ intention to become an entrepreneur. The objective of this research is to compare entrepreneurship intention between business students and non-business students. A self-administered questionnaire was used to collect data for this study. Questionnaires were distributed to respondents by applying the drop-off/pick-up method. A number of 294 by questionnaires were used in the analysis. Data were analyzed by using structural equation modeling. Two out of four hypotheses were confirmed. These hypotheses are the relationship between the attitude toward becoming an entrepreneur and the intention to try becoming an entrepreneur, and the relationship perceived behavioral control and intention to try becoming an entrepreneur. This paper also provides a discussion and offers directions for future research.

  20. Comparing Entrepreneurship Intention: A Multigroup Structural Equation Modeling Approach

    Directory of Open Access Journals (Sweden)

    Sabrina O. Sihombing

    2012-04-01

    Full Text Available Unemployment is one of the main social and economic problems that many countries face nowadays. One strategic way to overcome this problem is by fostering entrepreneurship spirit especially for unem ployment graduates. Entrepreneurship is becoming an alternative Job for students after they graduate. This is because entrepreneurship of-fers major benefits, such as setting up one’s own business and the pos-sibility of having significant financial rewards than working for others. Entrepreneurship is then offered by many universities. This research applies the theory of planned behavior (TPB by incorporating attitude toward success as an antecedent variable of the attitude to examine students’ intention to become an entrepreneur. The objective of this research is to compare entrepreneurship intention between business students and non-business students. A self-administered questionnaire was used to collect data for this study. Questionnaires were distributed to respondents by applying the drop-off/pick-up method. A number of 294 by questionnaires were used in the analysis. Data were analyzed by using structural equation modeling. Two out of four hypotheses were confirmed. These hypotheses are the relationship between the attitude toward becoming an entrepreneur and the intention to try becoming an entrepreneur, and the relationship perceived behavioral control and intention to try becoming an entrepreneur. This paper also provides a discussion and offers directions for future research.

  1. Modelling carbon stocks and fluxes in the wood product sector: a comparative review.

    Science.gov (United States)

    Brunet-Navarro, Pau; Jochheim, Hubert; Muys, Bart

    2016-07-01

    In addition to forest ecosystems, wood products are carbon pools that can be strategically managed to mitigate climate change. Wood product models (WPMs) simulating the carbon balance of wood production, use and end of life can complement forest growth models to evaluate the mitigation potential of the forest sector as a whole. WPMs can be used to compare scenarios of product use and explore mitigation strategies. A considerable number of WPMs have been developed in the last three decades, but there is no review available analysing their functionality and performance. This study analyses and compares 41 WPMs. One surprising initial result was that we discovered the erroneous implementation of a few concepts and assumptions in some of the models. We further described and compared the models using six model characteristics (bucking allocation, industrial processes, carbon pools, product removal, recycling and substitution effects) and three model-use characteristics (system boundaries, model initialization and evaluation of results). Using a set of indicators based on the model characteristics, we classified models using a hierarchical clustering technique and differentiated them according to their increasing degrees of complexity and varying levels of user support. For purposes of simulating carbon stock in wood products, models with a simple structure may be sufficient, but to compare climate change mitigation options, complex models are needed. The number of models has increased substantially over the last ten years, introducing more diversity and accuracy. Calculation of substitution effects and recycling has also become more prominent. However, the lack of data is still an important constraint for a more realistic estimation of carbon stocks and fluxes. Therefore, if the sector wants to demonstrate the environmental quality of its products, it should make it a priority to provide reliable life cycle inventory data, particularly regarding aspects of time and

  2. Comparative analysis of business rules and business process modeling languages

    Directory of Open Access Journals (Sweden)

    Audrius Rima

    2013-03-01

    Full Text Available During developing an information system is important to create clear models and choose suitable modeling languages. The article analyzes the SRML, SBVR, PRR, SWRL, OCL rules specifying language and UML, DFD, CPN, EPC and IDEF3 BPMN business process modeling language. The article presents business rules and business process modeling languages theoretical comparison. The article according to selected modeling aspects of the comparison between different business process modeling languages ​​and business rules representation languages sets. Also, it is selected the best fit of language set for three layer framework for business rule based software modeling.

  3. Comparative Analysis of River Flow Modelling by Using Supervised Learning Technique

    Science.gov (United States)

    Ismail, Shuhaida; Mohamad Pandiahi, Siraj; Shabri, Ani; Mustapha, Aida

    2018-04-01

    The goal of this research is to investigate the efficiency of three supervised learning algorithms for forecasting monthly river flow of the Indus River in Pakistan, spread over 550 square miles or 1800 square kilometres. The algorithms include the Least Square Support Vector Machine (LSSVM), Artificial Neural Network (ANN) and Wavelet Regression (WR). The forecasting models predict the monthly river flow obtained from the three models individually for river flow data and the accuracy of the all models were then compared against each other. The monthly river flow of the said river has been forecasted using these three models. The obtained results were compared and statistically analysed. Then, the results of this analytical comparison showed that LSSVM model is more precise in the monthly river flow forecasting. It was found that LSSVM has he higher r with the value of 0.934 compared to other models. This indicate that LSSVM is more accurate and efficient as compared to the ANN and WR model.

  4. Regionalization of climate model results for the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Kauker, F. [Alfred-Wegener-Institut fuer Polar- und Meeresforschung, Bremerhaven (Germany); Storch, H. von [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Hydrophysik

    2000-07-01

    A dynamical downscaling for the North Sea is presented. The numerical model used for the study is the coupled ice-ocean model OPYC. In a hindcast of the years 1979 to 1993 it was forced with atmospheric forcing of the ECMWF reanalysis. The models capability in simulating the observed mean state and variability in the North Sea is demonstrated by the hindcast. Two time scale ranges, from weekly to seasonal and the longer-than-seasonal time scales are investigated. Shorter time scales, for storm surges, are not captured by the model formulation. The main modes of variability of sea level, sea-surface circulation, sea-surface temperature, and sea-surface salinity are described and connections to atmospheric phenomena, like the NAO, are discussed. T106 ''time-slice'' simulations with a ''2 x CO{sub 2}'' horizon are used to estimate the effects of a changing climate on the shelf sea ''North Sea''. The ''2 x CO{sub 2}'' changes in the surface forcing are accompanied by changes in the lateral oceanic boundary conditions taken from a global coupled climate model. For ''2 x CO{sub 2}'' the time mean sea level increases up to 25 cm in the German Bight in the winter, where 15 cm are due to the surface forcing and 10 cm due to thermal expansion. This change is compared to the ''natural'' variability as simulated in the ECMWF integration and found to be not outside the range spanned by it. The variability of sea level on the weekly-to-seasonal time-scales is significantly reduced in the scenario integration. The variability on the longer-than-seasonal time-scales in the control and scenario runs is much smaller then in the ECMWF integration. This is traced back to the use of ''time-slice'' experiments. Discriminating between locally forced changes and changes induced at the lateral oceanic boundaries of the model in the circulation and

  5. Measurement model choice influenced randomized controlled trial results.

    Science.gov (United States)

    Gorter, Rosalie; Fox, Jean-Paul; Apeldoorn, Adri; Twisk, Jos

    2016-11-01

    In randomized controlled trials (RCTs), outcome variables are often patient-reported outcomes measured with questionnaires. Ideally, all available item information is used for score construction, which requires an item response theory (IRT) measurement model. However, in practice, the classical test theory measurement model (sum scores) is mostly used, and differences between response patterns leading to the same sum score are ignored. The enhanced differentiation between scores with IRT enables more precise estimation of individual trajectories over time and group effects. The objective of this study was to show the advantages of using IRT scores instead of sum scores when analyzing RCTs. Two studies are presented, a real-life RCT, and a simulation study. Both IRT and sum scores are used to measure the construct and are subsequently used as outcomes for effect calculation. The bias in RCT results is conditional on the measurement model that was used to construct the scores. A bias in estimated trend of around one standard deviation was found when sum scores were used, where IRT showed negligible bias. Accurate statistical inferences are made from an RCT study when using IRT to estimate construct measurements. The use of sum scores leads to incorrect RCT results. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. PRELIMINARY RESULTS OF COMPARATIVE PHARMACOECONOMIC PROSPECTIVE STUDY OF DIFFERENT THERAPIES OF ARTERIAL HYPERTENSION

    Directory of Open Access Journals (Sweden)

    E. I. Tarlovskaya

    2015-12-01

    Full Text Available Aim. To carry out a comparative pharmacoeconomic analysis of two different types of antihypertensive therapy in patients with arterial hypertension (HT. Material and methods. 38 patients with essential HT (aged 18 to 70 years, 11 males and 27 females associated with metabolic syndrome, and having a history of previous ineffective antihypertensive therapy were included into the study. The patients were randomized into 2 groups. Patients of V/A group received a fixed combination of valsartan and amlodipine (Exforge, Novartis in dose of 5/160 and 10/160 mg depending on blood pressure (BP level. Patients of L/A group received losartan (Lorista, KRKA in dose of 100 mg and amlodipine (Tenox, KRKA in dose of 5 and 10 mg. Treatment duration was 24 weeks. If target level of BP was not achieved during 12 weeks, indapamide retard was added to the therapies (Ravel SR, KRKA. Dinamics of BP and left ventricular mass index (LVMI were considered. Cost-effectiveness method of analysis was used. Results. In V/A group 75% of patients achieved target BP levels for 24 weeks, while in L/A group — 33.3% of patients, and 16.7% of patients more after indapamide addition. L/A therapy cost was lower in comparison with this of V/A therapy: 57864.24 vs 156671.0 rubles per 24 weeks, respectively. Calculation shows that additional cost of 669.23 rubles during 24 weeks is needed to achieve BP target level in every next patient when V/A therapy is used instead of L/A therapy. LVMI reduction by 1% took 1015.13 rubles cost in V/A group and almost 6 times more in L/A group. Conclusion. Pharmacoeconomic analysis revealed that generic combination of L/A is the most cost-effective for BP reduction. Very low cost is required to achieve additional effect with original fixed V/A combination. V/A combination is the most economical for the left ventricular hypertrophy reduction. Thus, V/A combination is rational for use in HT patients with severe target-organs damage.

  7. Photovoltaic Grid-Connected Modeling and Characterization Based on Experimental Results

    Science.gov (United States)

    Humada, Ali M.; Hojabri, Mojgan; Sulaiman, Mohd Herwan Bin; Hamada, Hussein M.; Ahmed, Mushtaq N.

    2016-01-01

    A grid-connected photovoltaic (PV) system operates under fluctuated weather condition has been modeled and characterized based on specific test bed. A mathematical model of a small-scale PV system has been developed mainly for residential usage, and the potential results have been simulated. The proposed PV model based on three PV parameters, which are the photocurrent, IL, the reverse diode saturation current, Io, the ideality factor of diode, n. Accuracy of the proposed model and its parameters evaluated based on different benchmarks. The results showed that the proposed model fitting the experimental results with high accuracy compare to the other models, as well as the I-V characteristic curve. The results of this study can be considered valuable in terms of the installation of a grid-connected PV system in fluctuated climatic conditions. PMID:27035575

  8. A Comparative Study of Spectral Auroral Intensity Predictions From Multiple Electron Transport Models

    Science.gov (United States)

    Grubbs, Guy; Michell, Robert; Samara, Marilia; Hampton, Donald; Hecht, James; Solomon, Stanley; Jahn, Jorg-Micha

    2018-01-01

    It is important to routinely examine and update models used to predict auroral emissions resulting from precipitating electrons in Earth's magnetotail. These models are commonly used to invert spectral auroral ground-based images to infer characteristics about incident electron populations when in situ measurements are unavailable. In this work, we examine and compare auroral emission intensities predicted by three commonly used electron transport models using varying electron population characteristics. We then compare model predictions to same-volume in situ electron measurements and ground-based imaging to qualitatively examine modeling prediction error. Initial comparisons showed differences in predictions by the GLobal airglOW (GLOW) model and the other transport models examined. Chemical reaction rates and radiative rates in GLOW were updated using recent publications, and predictions showed better agreement with the other models and the same-volume data, stressing that these rates are important to consider when modeling auroral processes. Predictions by each model exhibit similar behavior for varying atmospheric constants, energies, and energy fluxes. Same-volume electron data and images are highly correlated with predictions by each model, showing that these models can be used to accurately derive electron characteristics and ionospheric parameters based solely on multispectral optical imaging data.

  9. Comparing the engineering program feeders from SiF and convention models

    Science.gov (United States)

    Roongruangsri, Warawaran; Moonpa, Niwat; Vuthijumnonk, Janyawat; Sangsuwan, Kampanart

    2018-01-01

    This research aims to compare the relationship between two types of engineering program feeder models within the technical education systems of Rajamangala University of Technology Lanna (RMUTL), Chiangmai, Thailand. To illustrate, the paper refers to two typologies of feeder models, which are the convention and the school in factory (SiF) models. The new SiF model is developed through a collaborative educational process between the sectors of industry, government and academia, using work-integrated learning. The research methodology were use to compared features of the the SiF model with conventional models in terms of learning outcome, funding budget for the study, the advantages and disadvantages from the point of view of students, professors, the university, government and industrial partners. The results of this research indicate that the developed SiF feeder model is the most pertinent ones as it meet the requirements of the university, the government and the industry. The SiF feeder model showed the ability to yield positive learning outcomes with low expenditures per student for both the family and the university. In parallel, the sharing of knowledge between university and industry became increasingly important in the process, which resulted in the improvement of industrial skills for professors and an increase in industrial based research for the university. The SiF feeder model meets its demand of public policy in supporting a skilled workforce for the industry, which could be an effective tool for the triple helix educational model of Thailand.

  10. Loss of spent fuel pool cooling PRA: Model and results

    Energy Technology Data Exchange (ETDEWEB)

    Siu, N.; Khericha, S.; Conroy, S.; Beck, S.; Blackman, H.

    1996-09-01

    This letter report documents models for quantifying the likelihood of loss of spent fuel pool cooling; models for identifying post-boiling scenarios that lead to core damage; qualitative and quantitative results generated for a selected plant that account for plant design and operational practices; a comparison of these results and those generated from earlier studies; and a review of available data on spent fuel pool accidents. The results of this study show that for a representative two-unit boiling water reactor, the annual probability of spent fuel pool boiling is 5 {times} 10{sup {minus}5} and the annual probability of flooding associated with loss of spent fuel pool cooling scenarios is 1 {times} 10{sup {minus}3}. Qualitative arguments are provided to show that the likelihood of core damage due to spent fuel pool boiling accidents is low for most US commercial nuclear power plants. It is also shown that, depending on the design characteristics of a given plant, the likelihood of either: (a) core damage due to spent fuel pool-associated flooding, or (b) spent fuel damage due to pool dryout, may not be negligible.

  11. SR-Site groundwater flow modelling methodology, setup and results

    Energy Technology Data Exchange (ETDEWEB)

    Selroos, Jan-Olof (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Follin, Sven (SF GeoLogic AB, Taeby (Sweden))

    2010-12-15

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken three groundwater flow modelling studies. These are performed within the SR-Site project and represent time periods with different climate conditions. The simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. Three time periods are addressed; the Excavation and operational phases, the Initial period of temperate climate after closure, and the Remaining part of the reference glacial cycle. The present report is a synthesis of the background reports describing the modelling methodology, setup, and results. It is the primary reference for the conclusions drawn in a SR-Site specific context concerning groundwater flow during the three climate periods. These conclusions are not necessarily provided explicitly in the background reports, but are based on the results provided in these reports. The main results and comparisons presented in the present report are summarised in the SR-Site Main report.

  12. Loss of spent fuel pool cooling PRA: Model and results

    International Nuclear Information System (INIS)

    Siu, N.; Khericha, S.; Conroy, S.; Beck, S.; Blackman, H.

    1996-09-01

    This letter report documents models for quantifying the likelihood of loss of spent fuel pool cooling; models for identifying post-boiling scenarios that lead to core damage; qualitative and quantitative results generated for a selected plant that account for plant design and operational practices; a comparison of these results and those generated from earlier studies; and a review of available data on spent fuel pool accidents. The results of this study show that for a representative two-unit boiling water reactor, the annual probability of spent fuel pool boiling is 5 x 10 -5 and the annual probability of flooding associated with loss of spent fuel pool cooling scenarios is 1 x 10 -3 . Qualitative arguments are provided to show that the likelihood of core damage due to spent fuel pool boiling accidents is low for most US commercial nuclear power plants. It is also shown that, depending on the design characteristics of a given plant, the likelihood of either: (a) core damage due to spent fuel pool-associated flooding, or (b) spent fuel damage due to pool dryout, may not be negligible

  13. Communication about results of comparative effectiveness studies: a pharmaceutical industry view.

    Science.gov (United States)

    Perfetto, Eleanor M; Bailey, John E; Gans-Brangs, Kathleen R; Romano, Steven J; Rosenthal, Norman R; Willke, Richard J

    2012-10-01

    This article provides a perspective from the pharmaceutical industry on a hypothetical comparative effectiveness research case, highlighting tension between the reality of conducting comparative effectiveness research and the regulation of biopharmaceutical industry communication. Specifically, under current law and regulations, Aesculapion, the hypothetical maker of the fictional migraine headache drug Hemikrane, would have limited ability to communicate findings or to respond to inaccurate "what-if" scenario communications. Principles for communicating drug information could increase decision makers' access to information while making it easier for them to assess the quality and potential biases of different information sources. The article proposes two complementary approaches: formal Food and Drug Administration guidance clarifying how industry can participate meaningfully and proactively in the comparative effectiveness research discourse, possibly based on 1997 legislation governing communication of "health care economic information"; and stakeholder collaboration on development and adoption of voluntary "good communication principles."

  14. A computational approach to compare regression modelling strategies in prediction research.

    Science.gov (United States)

    Pajouheshnia, Romin; Pestman, Wiebe R; Teerenstra, Steven; Groenwold, Rolf H H

    2016-08-25

    It is often unclear which approach to fit, assess and adjust a model will yield the most accurate prediction model. We present an extension of an approach for comparing modelling strategies in linear regression to the setting of logistic regression and demonstrate its application in clinical prediction research. A framework for comparing logistic regression modelling strategies by their likelihoods was formulated using a wrapper approach. Five different strategies for modelling, including simple shrinkage methods, were compared in four empirical data sets to illustrate the concept of a priori strategy comparison. Simulations were performed in both randomly generated data and empirical data to investigate the influence of data characteristics on strategy performance. We applied the comparison framework in a case study setting. Optimal strategies were selected based on the results of a priori comparisons in a clinical data set and the performance of models built according to each strategy was assessed using the Brier score and calibration plots. The performance of modelling strategies was highly dependent on the characteristics of the development data in both linear and logistic regression settings. A priori comparisons in four empirical data sets found that no strategy consistently outperformed the others. The percentage of times that a model adjustment strategy outperformed a logistic model ranged from 3.9 to 94.9 %, depending on the strategy and data set. However, in our case study setting the a priori selection of optimal methods did not result in detectable improvement in model performance when assessed in an external data set. The performance of prediction modelling strategies is a data-dependent process and can be highly variable between data sets within the same clinical domain. A priori strategy comparison can be used to determine an optimal logistic regression modelling strategy for a given data set before selecting a final modelling approach.

  15. A comparative study of turbulence models for dissolved air flotation flow analysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Min A; Lee, Kyun Ho; Chung, Jae Dong [School of Mechanical and Aerospace Engineering, Sejong University, Seoul (Korea, Republic of); Seo, Seung Ho [Tops Engineering Co, Ltd., Gwangmyeong (Korea, Republic of)

    2015-07-15

    The dissolved air flotation (DAF) system is a water treatment process that removes contaminants by attaching micro bubbles to them, causing them to float to the water surface. In the present study, two-phase flow of air-water mixture is simulated to investigate changes in the internal flow analysis of DAF systems caused by using different turbulence models. Internal micro bubble distribution, velocity, and computation time are compared between several turbulence models for a given DAF geometry and condition. As a result, it is observed that the standard κ-ε model, which has been frequently used in previous research, predicts somewhat different behavior than other turbulence models.

  16. A comparative study of turbulence models for dissolved air flotation flow analysis

    International Nuclear Information System (INIS)

    Park, Min A; Lee, Kyun Ho; Chung, Jae Dong; Seo, Seung Ho

    2015-01-01

    The dissolved air flotation (DAF) system is a water treatment process that removes contaminants by attaching micro bubbles to them, causing them to float to the water surface. In the present study, two-phase flow of air-water mixture is simulated to investigate changes in the internal flow analysis of DAF systems caused by using different turbulence models. Internal micro bubble distribution, velocity, and computation time are compared between several turbulence models for a given DAF geometry and condition. As a result, it is observed that the standard κ-ε model, which has been frequently used in previous research, predicts somewhat different behavior than other turbulence models

  17. Results of the benchmark for blade structural models, part A

    DEFF Research Database (Denmark)

    Lekou, D.J.; Chortis, D.; Belen Fariñas, A.

    2013-01-01

    Task 2.2 of the InnWind.Eu project. The benchmark is based on the reference wind turbine and the reference blade provided by DTU [1]. "Structural Concept developers/modelers" of WP2 were provided with the necessary input for a comparison numerical simulation run, upon definition of the reference blade......A benchmark on structural design methods for blades was performed within the InnWind.Eu project under WP2 “Lightweight Rotor” Task 2.2 “Lightweight structural design”. The present document is describes the results of the comparison simulation runs that were performed by the partners involved within...

  18. Preliminary results of steel containment vessel model test

    International Nuclear Information System (INIS)

    Matsumoto, T.; Komine, K.; Arai, S.

    1997-01-01

    A high pressure test of a mixed-scaled model (1:10 in geometry and 1:4 in shell thickness) of a steel containment vessel (SCV), representing an improved boiling water reactor (BWR) Mark II containment, was conducted on December 11-12, 1996 at Sandia National Laboratories. This paper describes the preliminary results of the high pressure test. In addition, the preliminary post-test measurement data and the preliminary comparison of test data with pretest analysis predictions are also presented

  19. A Comparative Metroscope Model for Urban Information Flows

    Science.gov (United States)

    Fink, J. H.; Shandas, V.; Beaudoin, F.

    2011-12-01

    One of the most promising ways to achieve global sustainability goals of climate stabilization, poverty reduction, and biodiversity preservation is to make the world's cities more efficient, equitable, and healthful. While each city must follow a unique and somewhat idiosyncratic path toward these linked goals based on its history, geography, demography, and politics, movement in this direction can accelerate if cities can learn from each other more effectively. Such learning requires the identification of common characteristics and methodologies. We have created a framework for organizing and applying urban information flows, which we refer to as "Metroscopes." Metroscopes, which are analogous to the large instruments that have advanced the physical and life sciences, integrate six elements: data collection and input; classification through the use of metrics; data storage and retrieval; analytics and modeling; decision support including visualization and scenario generation; and assessment of the effectiveness of policy choices. Standards for each of these elements can be agreed upon by relevant urban science and policy sub-communities, and then can evolve as technologies and practices advance. We are implementing and calibrating this approach using data and relationships from Portland (OR), Phoenix (AZ) and London (UK). Elements that are being integrated include the Global City Indicators Facility at University of Toronto, the J-Earth database system and Decision Theater from Arizona State University, urban mobility analyses performed by the SENSEable City Lab at MIT, and Portland's Ecodistrict approach for urban management. Individual Metroscopes can be compared directly from one city to another, or with larger assemblages of cities like those being classified by ICLEI's STAR program, the Clinton Climate Initiative's C40, and Siemens Green Cities Index. This large-scale integration of urban data sets and approaches and its systematic comparison are key steps

  20. THE ECONOMIC IMPACT OF BGH ON THE NEW YORK STATE DAIRY SECTOR: COMPARATIVE STATIC RESULTS

    OpenAIRE

    Magrath, William B.; Tauer, Loren W.

    1986-01-01

    The price and quantity effects of a forthcoming biotechnology product, bovine growth hormone (bGH), are explored in a simple partial equilibrium model. The model is based on previous theoretical work on technological change but is developed in terms of a sector output. A particular output curve is estimated using data from a random sample of New York State dairy farms. Information on the farm level production effects of bGH is used to shift the output curve and to solve for equilibrium levels...

  1. Comparative digital cartilage histology for human and common osteoarthritis models

    Directory of Open Access Journals (Sweden)

    Pedersen DR

    2013-02-01

    Full Text Available Douglas R Pedersen, Jessica E Goetz, Gail L Kurriger, James A MartinDepartment of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA, USAPurpose: This study addresses the species-specific and site-specific details of weight-bearing articular cartilage zone depths and chondrocyte distributions among humans and common osteoarthritis (OA animal models using contemporary digital imaging tools. Histological analysis is the gold-standard research tool for evaluating cartilage health, OA severity, and treatment efficacy. Historically, evaluations were made by expert analysts. However, state-of-the-art tools have been developed that allow for digitization of entire histological sections for computer-aided analysis. Large volumes of common digital cartilage metrics directly complement elucidation of trends in OA inducement and concomitant potential treatments.Materials and methods: Sixteen fresh human knees, 26 adult New Zealand rabbit stifles, and 104 bovine lateral plateaus were measured for four cartilage zones and the cell densities within each zone. Each knee was divided into four weight-bearing sites: the medial and lateral plateaus and femoral condyles.Results: One-way analysis of variance followed by pairwise multiple comparisons (Holm–Sidak method at a significance of 0.05 clearly confirmed the variability between cartilage depths at each site, between sites in the same species, and between weight-bearing articular cartilage definitions in different species.Conclusion: The present study clearly demonstrates multisite, multispecies differences in normal weight-bearing articular cartilage, which can be objectively quantified by a common digital histology imaging technique. The clear site-specific differences in normal cartilage must be taken into consideration when characterizing the pathoetiology of OA models. Together, these provide a path to consistently analyze the volume and variety of histologic slides necessarily generated

  2. Comparing satellite SAR and wind farm wake models

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Vincent, P.; Husson, R.

    2015-01-01

    . These extend several tens of kilometres downwind e.g. 70 km. Other SAR wind maps show near-field fine scale details of wake behind rows of turbines. The satellite SAR wind farm wake cases are modelled by different wind farm wake models including the PARK microscale model, the Weather Research and Forecasting...... (WRF) model in high resolution and WRF with coupled microscale parametrization....

  3. A regional climate model for northern Europe: model description and results from the downscaling of two GCM control simulations

    Science.gov (United States)

    Rummukainen, M.; Räisänen, J.; Bringfelt, B.; Ullerstig, A.; Omstedt, A.; Willén, U.; Hansson, U.; Jones, C.

    This work presents a regional climate model, the Rossby Centre regional Atmospheric model (RCA1), recently developed from the High Resolution Limited Area Model (HIRLAM). The changes in the HIRLAM parametrizations, necessary for climate-length integrations, are described. A regional Baltic Sea ocean model and a modeling system for the Nordic inland lake systems have been coupled with RCA1. The coupled system has been used to downscale 10-year time slices from two different general circulation model (GCM) simulations to provide high-resolution regional interpretation of large-scale modeling. A selection of the results from the control runs, i.e. the present-day climate simulations, are presented: large-scale free atmospheric fields, the surface temperature and precipitation results and results for the on-line simulated regional ocean and lake surface climates. The regional model modifies the surface climate description compared to the GCM simulations, but it is also substantially affected by the biases in the GCM simulations. The regional model also improves the representation of the regional ocean and the inland lakes, compared to the GCM results.

  4. A regional climate model for northern Europe: model description and results from the downscaling of two GCM control simulations

    Energy Technology Data Exchange (ETDEWEB)

    Rummukainen, M.; Raeisaenen, J.; Bringfelt, B.; Ullerstig, A.; Omstedt, A.; Willen, U.; Hansson, U.; Jones, C. [Rossby Centre, Swedish Meteorological and Hydrological Inst., Norrkoeping (Sweden)

    2001-03-01

    This work presents a regional climate model, the Rossby Centre regional Atmospheric model (RCA1), recently developed from the High Resolution Limited Area Model (HIRLAM). The changes in the HIRLAM parametrizations, necessary for climate-length integrations, are described. A regional Baltic Sea ocean model and a modeling system for the Nordic inland lake systems have been coupled with RCA1. The coupled system has been used to downscale 10-year time slices from two different general circulation model (GCM) simulations to provide high-resolution regional interpretation of large-scale modeling. A selection of the results from the control runs, i.e. the present-day climate simulations, are presented: large-scale free atmospheric fields, the surface temperature and precipitation results and results for the on-line simulated regional ocean and lake surface climates. The regional model modifies the surface climate description compared to the GCM simulations, but it is also substantially affected by the biases in the GCM simulations. The regional model also improves the representation of the regional ocean and the inland lakes, compared to the GCM results. (orig.)

  5. Mississippi Communities for Healthy Living: Results of a 6-Month Nutrition Education Comparative Effectiveness Trial

    Science.gov (United States)

    Landry, Alicia S.; Thomson, Jessica L.; Huye, Holly F.; Yadrick, Kathy; Connell, Carol L.

    2017-01-01

    Background: Improving the diet of communities experiencing health inequities can be challenging given that multiple dietary components are low in quality. Mississippi Communities for Healthy Living was designed to test the comparative effectiveness of nutrition education using a single- versus multiple-message approach to improve the diet of adult…

  6. Determinants of health policy impact: comparative results of a European policymaker study.

    NARCIS (Netherlands)

    Rütten, A.; Lüschen, G.; Lengerke, T. von; Abel, T.; Kannas, L.; Rodríguez Diaz, J.A.; Vinck, J.; Zee, J. van der

    2003-01-01

    OBJECTIVES: This article will use a new theoretical framework for the analysis of health policy impact introduced by Rutten et al. (2003). In particular, it will report on a comparative European study of policymakers' perception and evaluation of specific determinants of the policy impact, both in

  7. Why Returning to VET? Results of a Qualitative Comparative Study about English and German Car Mechatronics

    Science.gov (United States)

    Gericke, Erika

    2017-01-01

    Educational choices, especially the influence of class on these choices have been a subject of lively international debate. However, thus far, there has been little international and comparative research with respect to vocational and education training (VET) decision making from a subject-oriented perspective. This paper considers…

  8. Comparative Analysis of ANN and SVM Models Combined with Wavelet Preprocess for Groundwater Depth Prediction

    Directory of Open Access Journals (Sweden)

    Ting Zhou

    2017-10-01

    Full Text Available Reliable prediction of groundwater depth fluctuations has been an important component in sustainable water resources management. In this study, a data-driven prediction model combining discrete wavelet transform (DWT preprocess and support vector machine (SVM was proposed for groundwater depth forecasting. Regular artificial neural networks (ANN, regular SVM, and wavelet preprocessed artificial neural networks (WANN models were also developed for comparison. These methods were applied to the monthly groundwater depth records over a period of 37 years from ten wells in the Mengcheng County, China. Relative absolute error (RAE, Pearson correlation coefficient (r, root mean square error (RMSE, and Nash-Sutcliffe efficiency (NSE were adopted for model evaluation. The results indicate that wavelet preprocess extremely improved the training and test performance of ANN and SVM models. The WSVM model provided the most precise and reliable groundwater depth prediction compared with ANN, SVM, and WSVM models. The criterion of RAE, r, RMSE, and NSE values for proposed WSVM model are 0.20, 0.97, 0.18 and 0.94, respectively. Comprehensive comparisons and discussion revealed that wavelet preprocess extremely improves the prediction precision and reliability for both SVM and ANN models. The prediction result of SVM model is superior to ANN model in generalization ability and precision. Nevertheless, the performance of WANN is superior to SVM model, which further validates the power of data preprocess in data-driven prediction models. Finally, the optimal model, WSVM, is discussed by comparing its subseries performances as well as model performance stability, revealing the efficiency and universality of WSVM model in data driven prediction field.

  9. A comparative analysis of pricing models for enterprise cloud platforms

    CSIR Research Space (South Africa)

    Mvelase, P

    2013-09-01

    Full Text Available virtual enterprise (VE)-enabled cloud enterprise architecture for small medium and micro enterprises (SMMEs) against EC2 pricing model to prove that our pricing model is more suitable for small medium and micro enterprises (SMMEs). This model is based...

  10. Emissions measurements from vegetation fires: A comparative evaluation of methods and results

    Science.gov (United States)

    D. E. Ward; L. F. Radke

    1993-01-01

    Fires in the open environment produce a diversity of combustion products. Special techniques are needed to characterize the emissions ranging from microcombustion-evolved gas analysis to airborne monitoring of the full-scale phenomenon. This chapter discusses the advantages and disadvantages of each, the use of data in models for full-scale fires, and provides a...

  11. General vs health specialized search engine: a blind comparative evaluation of top search results.

    Science.gov (United States)

    Pletneva, Natalia; Ruiz de Castaneda, Rafael; Baroz, Frederic; Boyer, Celia

    2014-01-01

    This paper presents the results of a blind comparison of top ten search results retrieved by Google.ch (French) and Khresmoi for everyone, a health specialized search engine. Participants--students of the Faculty of Medicine of the University of Geneva had to complete three tasks and select their preferred results. The majority of the participants have largely preferred Google results while Khresmoi results showed potential to compete in specific topics. The coverage of the results seems to be one of the reasons. The second being that participants do not know how to select quality and transparent health web pages. More awareness, tools and education about the matter is required for the students of Medicine to be able to efficiently distinguish trustworthy online health information.

  12. Comparative Validation of Realtime Solar Wind Forecasting Using the UCSD Heliospheric Tomography Model

    Science.gov (United States)

    MacNeice, Peter; Taktakishvili, Alexandra; Jackson, Bernard; Clover, John; Bisi, Mario; Odstrcil, Dusan

    2011-01-01

    The University of California, San Diego 3D Heliospheric Tomography Model reconstructs the evolution of heliospheric structures, and can make forecasts of solar wind density and velocity up to 72 hours in the future. The latest model version, installed and running in realtime at the Community Coordinated Modeling Center(CCMC), analyzes scintillations of meter wavelength radio point sources recorded by the Solar-Terrestrial Environment Laboratory(STELab) together with realtime measurements of solar wind speed and density recorded by the Advanced Composition Explorer(ACE) Solar Wind Electron Proton Alpha Monitor(SWEPAM).The solution is reconstructed using tomographic techniques and a simple kinematic wind model. Since installation, the CCMC has been recording the model forecasts and comparing them with ACE measurements, and with forecasts made using other heliospheric models hosted by the CCMC. We report the preliminary results of this validation work and comparison with alternative models.

  13. Comparative evaluation of statistical and mechanistic models of Escherichia coli at beaches in southern Lake Michigan

    Science.gov (United States)

    Safaie, Ammar; Wendzel, Aaron; Ge, Zhongfu; Nevers, Meredith; Whitman, Richard L.; Corsi, Steven R.; Phanikumar, Mantha S.

    2016-01-01

    Statistical and mechanistic models are popular tools for predicting the levels of indicator bacteria at recreational beaches. Researchers tend to use one class of model or the other, and it is difficult to generalize statements about their relative performance due to differences in how the models are developed, tested, and used. We describe a cooperative modeling approach for freshwater beaches impacted by point sources in which insights derived from mechanistic modeling were used to further improve the statistical models and vice versa. The statistical models provided a basis for assessing the mechanistic models which were further improved using probability distributions to generate high-resolution time series data at the source, long-term “tracer” transport modeling based on observed electrical conductivity, better assimilation of meteorological data, and the use of unstructured-grids to better resolve nearshore features. This approach resulted in improved models of comparable performance for both classes including a parsimonious statistical model suitable for real-time predictions based on an easily measurable environmental variable (turbidity). The modeling approach outlined here can be used at other sites impacted by point sources and has the potential to improve water quality predictions resulting in more accurate estimates of beach closures.

  14. Towards consensus in comparative chemical characterization modeling for LCIA

    DEFF Research Database (Denmark)

    Hauschild, Michael Zwicky; Bachmann, Till; Huijbregts, Mark

    2006-01-01

    The Task Force on Toxic Impacts under the UNEP/SETAC Life Cycle Initiative is developing recommendations on characterization models and characterization factors for human toxicity and ecotoxicity impacts in Life Cycle Impact Assessment (LCIA). Building on experience from earlier model development...... unnecessary differences. Based on the adapted set of models and their outcomes, and on the earlier guidelines for fate modeling, overall guidelines for toxicity modeling in LCIA were developed. In line with these overall guidelines, a simple consensus model was developed. This model is collectively owned...... and to be the basis of the “recommended practice” for calculation of characterization factors for chemicals under authority of the UNEP/SETAC Life Cycle Initiative....

  15. Per-oral endoscopic myotomy for achalasia. Are results comparable to laparoscopic Heller myotomy?

    Science.gov (United States)

    Kumagai, Koshi; Tsai, Jon A; Thorell, Anders; Lundell, Lars; Håkanson, Bengt

    2015-05-01

    Per-oral endoscopic myotomy (POEM) has recently been introduced as a minimal invasive alternative to conventional treatment for achalasia. This study aimed to clarify the feasibility and the short-term clinical efficacy of POEM as compared to laparoscopic Heller myotomy (LHM). Treatment outcomes were prospectively recorded and compared between the procedures in a nonrandomized fashion. Reduction rate (RR) in timed barium esophagogram (TBE) was calculated at 1, 2 and 5 min after barium ingestion as: RR = 1- postoperative barium height/preoperative barium height. Risk factors for treatment failure defined as the proportion of patients with RR <0.5 (1 min) and gastroesophageal reflux (GER) after POEM were analyzed. Forty-two consecutive patients who underwent POEM were compared to 41 patients who had a LHM during the immediate time period prior to the introduction of POEM. Ninety percent of the cases reported complete symptom relief after POEM. The percentage of esophageal emptying and RR in TBE improved dramatically by both procedures without significant difference. A longer operation time (odds ratio [OR] 32.80, 95%CI 2.99-359.82, p = 0.004) and younger age (OR 26.81, 95%CI 2.09-344.03, p = 0.012) were the independent predictors of treatment failure after POEM. GER was observed in seven patients where previous dilatation (OR 8.59, 95%CI 1.16-63.45, p = 0.035) and higher body mass index (OR 8.69, 95%CI 1.13-66.63, p = 0.037) were the independent predictors for symptomatic GER after POEM. POEM seems to be a safe and effective treatment option for achalasia in the short-term perspective; an effect well comparable to LHM.

  16. Characterizing cavities in model inclusion molecules: a comparative study.

    Science.gov (United States)

    Torrens, F; Sánchez-Marín, J; Nebot-Gil, I

    1998-04-01

    We have selected fullerene-60 and -70 cavities as model systems in order to test several methods for characterizing inclusion molecules. The methods are based on different technical foundations such as a square and triangular tessellation of the molecule taken as a unitary sphere, spherical tessellation of the molecular surface, numerical integration of the atomic volumes and surfaces, triangular tessellation of the molecular surface, and a cubic lattice approach to a molecular space. Accurate measures of the molecular volume and surface area have been performed with the pseudo-random Monte Carlo (MCVS) and uniform Monte Carlo (UMCVS) methods. These calculations serve as a reference for the rest of the methods. The SURMO2 and MS methods have not recognized the cavities and may not be convenient for intercalation compounds. The programs that have detected the cavities never exceed 5% deviation relative to the reference values for molecular volume and surface area. The GEPOL algorithm, alone or combined with TOPO, shows results in good agreement with those of the UMCVS reference. The uniform random number generator provides the fastest convergence for UMCVS and a correct estimate of the standard deviations. The effect of the internal cavity on the accessible surfaces has been calculated.

  17. A Comparative Study of Theoretical Graph Models for Characterizing Structural Networks of Human Brain

    Directory of Open Access Journals (Sweden)

    Xiaojin Li

    2013-01-01

    Full Text Available Previous studies have investigated both structural and functional brain networks via graph-theoretical methods. However, there is an important issue that has not been adequately discussed before: what is the optimal theoretical graph model for describing the structural networks of human brain? In this paper, we perform a comparative study to address this problem. Firstly, large-scale cortical regions of interest (ROIs are localized by recently developed and validated brain reference system named Dense Individualized Common Connectivity-based Cortical Landmarks (DICCCOL to address the limitations in the identification of the brain network ROIs in previous studies. Then, we construct structural brain networks based on diffusion tensor imaging (DTI data. Afterwards, the global and local graph properties of the constructed structural brain networks are measured using the state-of-the-art graph analysis algorithms and tools and are further compared with seven popular theoretical graph models. In addition, we compare the topological properties between two graph models, namely, stickiness-index-based model (STICKY and scale-free gene duplication model (SF-GD, that have higher similarity with the real structural brain networks in terms of global and local graph properties. Our experimental results suggest that among the seven theoretical graph models compared in this study, STICKY and SF-GD models have better performances in characterizing the structural human brain network.

  18. Commenting on Research Results in Applied Linguistics and Education: A Comparative Genre-Based Investigation

    Science.gov (United States)

    Lim, Jason Miin-Hwa

    2010-01-01

    As university students are frequently given the tasks of writing research reports to fulfil their respective programme requirements, teaching novice writers to present the results of their reports understandably constitutes an essential component of English lessons at tertiary level. While past research has shown that results are consistently…

  19. Comparative genome-scale metabolic modeling of actinomycetes : The topology of essential core metabolism

    NARCIS (Netherlands)

    Alam, Mohammad Tauqeer; Medema, Marnix H.; Takano, Eriko; Breitling, Rainer; Gojobori, Takashi

    2011-01-01

    Actinomycetes are highly important bacteria. On one hand, some of them cause severe human and plant diseases, on the other hand, many species are known for their ability to produce antibiotics. Here we report the results of a comparative analysis of genome-scale metabolic models of 37 species of

  20. Comparative genome-scale metabolic modeling of actinomycetes: the topology of essential core metabolism.

    NARCIS (Netherlands)

    Alam, M.T.; Medema, M.H.; Takano, E.; Breitling, R.

    2011-01-01

    Actinomycetes are highly important bacteria. On one hand, some of them cause severe human and plant diseases, on the other hand, many species are known for their ability to produce antibiotics. Here we report the results of a comparative analysis of genome-scale metabolic models of 37 species of

  1. Mathematical model comparing of the multi-level economics systems

    Science.gov (United States)

    Brykalov, S. M.; Kryanev, A. V.

    2017-12-01

    The mathematical model (scheme) of a multi-level comparison of the economic system, characterized by the system of indices, is worked out. In the mathematical model of the multi-level comparison of the economic systems, the indicators of peer review and forecasting of the economic system under consideration can be used. The model can take into account the uncertainty in the estimated values of the parameters or expert estimations. The model uses the multi-criteria approach based on the Pareto solutions.

  2. Comparing spatial diversification and meta-population models in the Indo-Australian Archipelago.

    Science.gov (United States)

    Chalmandrier, Loïc; Albouy, Camille; Descombes, Patrice; Sandel, Brody; Faurby, Soren; Svenning, Jens-Christian; Zimmermann, Niklaus E; Pellissier, Loïc

    2018-03-01

    Reconstructing the processes that have shaped the emergence of biodiversity gradients is critical to understand the dynamics of diversification of life on Earth. Islands have traditionally been used as model systems to unravel the processes shaping biological diversity. MacArthur and Wilson's island biogeographic model predicts diversity to be based on dynamic interactions between colonization and extinction rates, while treating islands themselves as geologically static entities. The current spatial configuration of islands should influence meta-population dynamics, but long-term geological changes within archipelagos are also expected to have shaped island biodiversity, in part by driving diversification. Here, we compare two mechanistic models providing inferences on species richness at a biogeographic scale: a mechanistic spatial-temporal model of species diversification and a spatial meta-population model. While the meta-population model operates over a static landscape, the diversification model is driven by changes in the size and spatial configuration of islands through time. We compare the inferences of both models to floristic diversity patterns among land patches of the Indo-Australian Archipelago. Simulation results from the diversification model better matched observed diversity than a meta-population model constrained only by the contemporary landscape. The diversification model suggests that the dynamic re-positioning of islands promoting land disconnection and reconnection induced an accumulation of particularly high species diversity on Borneo, which is central within the island network. By contrast, the meta-population model predicts a higher diversity on the mainlands, which is less compatible with empirical data. Our analyses highlight that, by comparing models with contrasting assumptions, we can pinpoint the processes that are most compatible with extant biodiversity patterns.

  3. Introducing Disappointment Dynamics and Comparing Behaviors in Evolutionary Games: Some Simulation Results

    Directory of Open Access Journals (Sweden)

    Tassos Patokos

    2014-01-01

    Full Text Available The paper presents an evolutionary model, based on the assumption that agents may revise their current strategies if they previously failed to attain the maximum level of potential payoffs. We offer three versions of this reflexive mechanism, each one of which describes a distinct type: spontaneous agents, rigid players, and ‘satisficers’. We use simulations to examine the performance of these types. Agents who change their strategies relatively easily tend to perform better in coordination games, but antagonistic games generally lead to more favorable outcomes if the individuals only change their strategies when disappointment from previous rounds surpasses some predefined threshold.

  4. TVT compared with TVT-O and TOT: results from the Norwegian National Incontinence Registry.

    Science.gov (United States)

    Dyrkorn, Ole A; Kulseng-Hanssen, Sigurd; Sandvik, Leiv

    2010-11-01

    The aim of this study is to compare the outcome and complication rates of the tension-free vaginal tape (TVT) operations with the transobturator vaginal tape (TVT-O and TOT) operations in the treatment of urinary stress incontinence. This is a multicenter, prospective cohort study. Preoperative and postoperative assessments included a validated Stress and Urge Incontinence Questionnaire, a 24-h pad test, and a standardized stress test. The study included 5,942 women--4,281 women had a TVT operation and 731 and 373 women had TVT-O and TOT operations, respectively. Median follow-up time was 8 months. Women in the TVT group had less leakage during stress test and fewer subjective stress incontinence symptoms, and were more satisfied with the operation compared with the women in TVT-O and TOT groups, but more complications were reported after TVT operation. The TVT operation is more efficient than TVT-O and TOT operations in treating stress incontinent women.

  5. Comparing adults who use cannabis medically with those who use recreationally: Results from a national sample.

    Science.gov (United States)

    Lin, Lewei A; Ilgen, Mark A; Jannausch, Mary; Bohnert, Kipling M

    2016-10-01

    Cannabis has been legalized for medical use in almost half of the states in the U.S. Although laws in these states make the distinction between medical and recreational use of cannabis, the prevalence of people using medical cannabis and how distinct this group is from individuals using cannabis recreationally is unknown at a national level. Data came from the 2013 National Survey on Drug Use and Health (NSDUH). All adults endorsing past year cannabis use who reported living in a state that had legalized medical cannabis were divided into recreational cannabis use only and medical cannabis use. Demographic and clinical characteristics were compared across these two groups. 17% of adults who used cannabis in the past year used cannabis medically. There were no significant differences between those who used medically versus recreationally in race, education, past year depression and prevalence of cannabis use disorders. In adjusted analyses, those with medical cannabis use were more likely to have poorer health and lower levels of alcohol use disorders and non-cannabis drug use. A third of those who reported medical cannabis use endorsed daily cannabis use compared to 11% in those who reported recreational use exclusively. Adults who use medical and recreational cannabis shared some characteristics, but those who used medical cannabis had higher prevalence of poor health and daily cannabis use. As more states legalize cannabis for medical use, it is important to better understand similarities and differences between people who use cannabis medically and recreationally. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Comparative evaluation of kinetic, equilibrium and semi-equilibrium models for biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

    Buragohain, Buljit [Center for Energy, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Chakma, Sankar; Kumar, Peeush [Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Mahanta, Pinakeswar [Center for Energy, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Moholkar, Vijayanand S. [Center for Energy, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India)

    2013-07-01

    Modeling of biomass gasification has been an active area of research for past two decades. In the published literature, three approaches have been adopted for the modeling of this process, viz. thermodynamic equilibrium, semi-equilibrium and kinetic. In this paper, we have attempted to present a comparative assessment of these three types of models for predicting outcome of the gasification process in a circulating fluidized bed gasifier. Two model biomass, viz. rice husk and wood particles, have been chosen for analysis, with gasification medium being air. Although the trends in molar composition, net yield and LHV of the producer gas predicted by three models are in concurrence, significant quantitative difference is seen in the results. Due to rather slow kinetics of char gasification and tar oxidation, carbon conversion achieved in single pass of biomass through the gasifier, calculated using kinetic model, is quite low, which adversely affects the yield and LHV of the producer gas. Although equilibrium and semi-equilibrium models reveal relative insensitivity of producer gas characteristics towards temperature, the kinetic model shows significant effect of temperature on LHV of the gas at low air ratios. Kinetic models also reveal volume of the gasifier to be an insignificant parameter, as the net yield and LHV of the gas resulting from 6 m and 10 m riser is same. On a whole, the analysis presented in this paper indicates that thermodynamic models are useful tools for quantitative assessment of the gasification process, while kinetic models provide physically more realistic picture.

  7. Position-sensitive transition edge sensor modeling and results

    Energy Technology Data Exchange (ETDEWEB)

    Hammock, Christina E-mail: chammock@milkyway.gsfc.nasa.gov; Figueroa-Feliciano, Enectali; Apodaca, Emmanuel; Bandler, Simon; Boyce, Kevin; Chervenak, Jay; Finkbeiner, Fred; Kelley, Richard; Lindeman, Mark; Porter, Scott; Saab, Tarek; Stahle, Caroline

    2004-03-11

    We report the latest design and experimental results for a Position-Sensitive Transition-Edge Sensor (PoST). The PoST is motivated by the desire to achieve a larger field-of-view without increasing the number of readout channels. A PoST consists of a one-dimensional array of X-ray absorbers connected on each end to a Transition Edge Sensor (TES). Position differentiation is achieved through a comparison of pulses between the two TESs and X-ray energy is inferred from a sum of the two signals. Optimizing such a device involves studying the available parameter space which includes device properties such as heat capacity and thermal conductivity as well as TES read-out circuitry parameters. We present results for different regimes of operation and the effects on energy resolution, throughput, and position differentiation. Results and implications from a non-linear model developed to study the saturation effects unique to PoSTs are also presented.

  8. comparative analysis of two mathematical models for prediction

    African Journals Online (AJOL)

    Abstract. A mathematical modeling for prediction of compressive strength of sandcrete blocks was performed using statistical analysis for the sandcrete block data ob- tained from experimental work done in this study. The models used are Scheffes and Osadebes optimization theories to predict the compressive strength of ...

  9. Comparative homology modeling of human rhodopsin with several ...

    African Journals Online (AJOL)

    The molecular structure of rhodopsin has been studied by cryo-electron microscopic, Nuclear Magnetic Resonance (NMR) and X-ray crystallographic techniques in bovine. A humble effort has been ... Key words: Homology modeling, human rhodopsin, bovine templates, sequence alignment, model building, energy profiles.

  10. Mental Models about Seismic Effects: Students' Profile Based Comparative Analysis

    Science.gov (United States)

    Moutinho, Sara; Moura, Rui; Vasconcelos, Clara

    2016-01-01

    Nowadays, meaningful learning takes a central role in science education and is based in mental models that allow the representation of the real world by individuals. Thus, it is essential to analyse the student's mental models by promoting an easier reconstruction of scientific knowledge, by allowing them to become consistent with the curricular…

  11. A comparative study of explicit and implicit modelling of ...

    Indian Academy of Sciences (India)

    Further, for both speaker identification and verification tasks the explicit modelling provides relatively more complimentary information to the state-of-the-art vocal tract features. The contribution of the explicit features is relatively more robust against noise. We suggest that the explicit approach can be used to model the ...

  12. Comparative Studies of Population Synthesis Models in the ...

    Indian Academy of Sciences (India)

    2014-01-08

    Jan 8, 2014 ... Strömgren photometry to measure reliable parameter-sensitive colours and estimate precise model ages and metallicities. The assessment of. Rakos/Schulz ... Overall, the assessment finds modified Strömgren photometry ... The history of stellar population modelling dates back to the attempts by Crampin.

  13. Comparative study of Moore and Mealy machine models adaptation ...

    African Journals Online (AJOL)

    Information and Communications Technology has influenced the need for automated machines that can carry out important production procedures and, automata models are among the computational models used in design and construction of industrial processes. The production process of the popular African Black Soap ...

  14. comparative study of moore and mealy machine models adaptation

    African Journals Online (AJOL)

    user

    Information and Communications Technology has influenced the need for automated machines that can carry out important production procedures and, automata models are among the computational models used in design and construction of industrial processes. The production process of the popular African Black Soap ...

  15. Comparative Analysis of Two Mathematical Models for Prediction of ...

    African Journals Online (AJOL)

    A mathematical modeling for prediction of compressive strength of sandcrete blocks was performed using statistical analysis for the sandcrete block data obtained from experimental work done in this study. The models used are Scheffe's and Osadebe's optimization theories to predict the compressive strength of sandcrete ...

  16. Comparative overview on the result of studies carried through to date

    International Nuclear Information System (INIS)

    Kuebler, K.

    1989-01-01

    The numerous expertises available show that it is not in fact unfeasible technically for the Federal Republic of Germany to opt out of nuclear power. This result is not an unimportant one for politics. But the expertises do not indicate that we should opt out of nuclear power now. In spite of all expertises, a comprehensive appraisal of nuclear power in the Federal Republic of Germany in economic, ecological, and socio-political respects is still lacking. So our political decisions must be taken on the basis of principles of common sense and certain calculating results within relatively narrow system boundaries. (orig/HSCH) [de

  17. A comparative study of Northern Ireland's estuaries based on the results of beam trawl fish surveys

    Science.gov (United States)

    Harrison, Trevor D.; Armour, Neil D.; McNeill, Michael T.; Moorehead, Peter W.

    2017-11-01

    The fish communities of Northern Ireland's estuaries were described and compared using data collected with a modified beam trawl over a six year period from 2009 to 2014. Multivariate analyses identified four estuary groups based on variations in their physico-chemical attributes. These groups broadly corresponded with the distribution and variation of estuary geomorphic types identified around the Irish coast. The dominant fish species captured were also among the main species reported in other North East Atlantic estuaries. A significant link between the estuary types and their fish communities was found; each estuary group contained a somewhat distinctive fish community. The fish communities also showed a significant relationship with the physico-chemical characteristics of the estuaries. Differences in fish species composition are attributed to habitat and environmental preferences of key estuary-associated species.

  18. Different pathways but same result? Comparing chemistry and biological effects of burned and decomposed litter

    Science.gov (United States)

    Mazzoleni, Stefano; Bonanomi, Giuliano; Incerti, Guido; El-Gawad, Ahmed M. Abd; Sarker, Tushar Chandra; Cesarano, Gaspare; Saulino, Luigi; Saracino, Antonio; Castro Rego, Francisco

    2017-04-01

    Litter burning and biological decomposition are oxidative processes co-occurring in many terrestrial ecosystems, producing organic matter with different chemical properties and differently affecting plant growth and soil microbial activity. Here, we tested the chemical convergence hypothesis (i.e. materials with different initial chemistry tend to converge towards a common profile, with similar biological effects, as the oxidative process advances) for burning and decomposition. We compared the molecular composition of 63 organic materials - 7 litter types either fresh, decomposed for 30, 90, 180 days, or heated at 100, 200, 300, 400, 500 °C - as assessed by 13C NMR. We used litter water extracts (5% dw) as treatments in bioassays on plant (Lepidium sativum) and fungal (Aspergillus niger) growth, and a washed quartz sand amended with litter materials (0.5 % dw) to assess heterotrophic respiration by CO2 flux chamber. We observed different molecular variations for materials either burning (i.e. a sharp increase of aromatic C and a decrease of most other fractions above 200 °C) or decomposing (i.e. early increase of alkyl, methoxyl and N-alkyl C and decrease of O-alkyl and di-O-alkyl C fractions). Soil respiration and fungal growth progressively decreased with litter age and temperature. Plant growth underwent an inhibitory effect by untreated litter, more and less rapidly released over decomposing and burning materials, respectively. Correlation analysis between NMR and bioassay data showed that opposite responses for soil respiration and fungi, compared to plants, are related to essentially the same C molecular types. Our findings suggest a functional convergence of decomposed and burnt organic substrates, emerging from the balance between the bioavailability of labile C sources and the presence of recalcitrant and pyrogenic compounds, oppositely affecting different trophic levels.

  19. Some gender issues in educational computer use: results of an international comparative survey

    NARCIS (Netherlands)

    Janssen Reinen, I.A.M.; Plomp, T.

    1993-01-01

    In the framework of the Computers in Education international study of the International Association for the Evaluation of Educational Achievement (IEA), data have been collected concerning the use of computers in 21 countries. This article examines some results regarding the involvement of women in

  20. Changes in Quality of Life Perceptions in Saskatoon, Saskatchewan: Comparing Survey Results from 2001 and 2004

    Science.gov (United States)

    Williams, Allison; Kitchen, Peter; Randall, James; Muhajarine, Nazeem

    2008-01-01

    There is a growing interest in quality of life (QoL) as an integrated approach to addressing key social, environmental and economic determinants of health. The University of Saskatchewan's Community-University Institute for Social Research (CUISR) has examined the process and results of a multi-stakeholder approach to the ongoing sustainability of…

  1. Exploratory Visual Analysis of Statistical Results from Microarray Experiments Comparing High and Low Grade Glioma

    Directory of Open Access Journals (Sweden)

    Jason H. Moore

    2007-01-01

    Full Text Available The biological interpretation of gene expression microarray results is a daunting challenge. For complex diseases such as cancer, wherein the body of published research is extensive, the incorporation of expert knowledge provides a useful analytical framework. We have previously developed the Exploratory Visual Analysis (EVA software for exploring data analysis results in the context of annotation information about each gene, as well as biologically relevant groups of genes. We present EVA as a fl exible combination of statistics and biological annotation that provides a straightforward visual interface for the interpretation of microarray analyses of gene expression in the most commonly occurring class of brain tumors, glioma. We demonstrate the utility of EVA for the biological interpretation of statistical results by analyzing publicly available gene expression profi les of two important glial tumors. The results of a statistical comparison between 21 malignant, high-grade glioblastoma multiforme (GBM tumors and 19 indolent, low-grade pilocytic astrocytomas were analyzed using EVA. By using EVA to examine the results of a relatively simple statistical analysis, we were able to identify tumor class-specifi c gene expression patterns having both statistical and biological signifi cance. Our interactive analysis highlighted the potential importance of genes involved in cell cycle progression, proliferation, signaling, adhesion, migration, motility, and structure, as well as candidate gene loci on a region of Chromosome 7 that has been implicated in glioma. Because EVA does not require statistical or computational expertise and has the fl exibility to accommodate any type of statistical analysis, we anticipate EVA will prove a useful addition to the repertoire of computational methods used for microarray data analysis. EVA is available at no charge to academic users and can be found at http://www.epistasis.org.

  2. Comparing sensitivity analysis methods to advance lumped watershed model identification and evaluation

    Directory of Open Access Journals (Sweden)

    Y. Tang

    2007-01-01

    Full Text Available This study seeks to identify sensitivity tools that will advance our understanding of lumped hydrologic models for the purposes of model improvement, calibration efficiency and improved measurement schemes. Four sensitivity analysis methods were tested: (1 local analysis using parameter estimation software (PEST, (2 regional sensitivity analysis (RSA, (3 analysis of variance (ANOVA, and (4 Sobol's method. The methods' relative efficiencies and effectiveness have been analyzed and compared. These four sensitivity methods were applied to the lumped Sacramento soil moisture accounting model (SAC-SMA coupled with SNOW-17. Results from this study characterize model sensitivities for two medium sized watersheds within the Juniata River Basin in Pennsylvania, USA. Comparative results for the 4 sensitivity methods are presented for a 3-year time series with 1 h, 6 h, and 24 h time intervals. The results of this study show that model parameter sensitivities are heavily impacted by the choice of analysis method as well as the model time interval. Differences between the two adjacent watersheds also suggest strong influences of local physical characteristics on the sensitivity methods' results. This study also contributes a comprehensive assessment of the repeatability, robustness, efficiency, and ease-of-implementation of the four sensitivity methods. Overall ANOVA and Sobol's method were shown to be superior to RSA and PEST. Relative to one another, ANOVA has reduced computational requirements and Sobol's method yielded more robust sensitivity rankings.

  3. Comparative study of stability in different TCP/RED models

    International Nuclear Information System (INIS)

    Nga, J.H.C.; Iu, H.H.C.; Ling, S.H.; Lam, H.K.

    2008-01-01

    This paper studies the stability issue of the average queue length of a Transmission Control Protocol (TCP) model when interacting with Random Early Detection (RED). The model used for the study has shown period doubling bifurcation (PDB) and border collision bifurcation (BCB) in the average queue size at certain values of parameters when original RED is deployed. In this paper, we adopt a gentle version of RED and a newly derived RED algorithm into the model to study the improvement in stability of average queue size of the system

  4. Portal Vein Embolization before Right Hepatectomy: Improved Results Using n-Butyl-Cyanoacrylate Compared to Microparticles Plus Coils

    Energy Technology Data Exchange (ETDEWEB)

    Guiu, Boris, E-mail: boris.guiu@chu-dijon.fr; Bize, Pierre; Gunthern, Daniel [Centre Hospitalo-Univeristaire Vaudois, Digestive and Oncologic Imaging and Interventional Radiology Unit, Department of Radiology and Interventional Radiology (Switzerland); Demartines, Nicolas; Halkic, Nermin [Centre Hospitalo-Univeristaire Vaudois, Department of Visceral Surgery (Switzerland); Denys, Alban [Centre Hospitalo-Univeristaire Vaudois, Digestive and Oncologic Imaging and Interventional Radiology Unit, Department of Radiology and Interventional Radiology (Switzerland)

    2013-10-15

    Background: There is currently no consensus in the literature on which embolic agent induces the greatest degree of liver hypertrophy after portal vein embolization (PVE). Only experimental results in a pig model have demonstrated an advantage of n-butyl-cyanoacrylate (NBCA) over 3 other embolic materials (hydrophilic gel, small and large polyvinyl alcohol particles) for PVE. Therefore, the aim of this human study was to retrospectively compare the results of PVE using NBCA with those using spherical microparticles plus coils. Methods: A total of 34 patients underwent PVE using either NBCA (n = 20), or spherical microparticles plus coils (n = 14). PVE was decided according to preoperative volumetry on the basis of contrast-enhanced CT. Groups were compared for age, sex, volume of the left lobe before PVE and future remnant liver ratio (FRL) (volume of the left lobe/total liver volume - tumor volume). The primary end point was the increase in left lobe volume 1 month after PVE. Secondary end points were procedure complications and biological tolerance. Results: Both groups were similar in terms of age, sex ratio, left lobe volume, and FRL before PVE. NBCA induced a greater increase in volume after PVE than did microparticles plus coils (respectively, +74 {+-} 69 % and +23 {+-} 14 %, p < 0.05). The amount of contrast medium used for the procedure was significantly larger when microparticles and coils rather than NBCA were used (respectively, 264 {+-} 43 ml and 162 {+-} 34 ml, p < 0.01). The rate of PVE complications as well as the biological tolerance was similar in both groups. Conclusion: NBCA seems more effective than spherical microparticles plus coils to induce left-lobe hypertrophy.

  5. The Nitrogen Footprint Tool for Institutions: Comparing Results for a Diverse Group of Institutions

    Science.gov (United States)

    Castner, E.; Leach, A. M.; Galloway, J. N.; Hastings, M. G.; Lantz-Trissel, J.; Leary, N.; Kimiecik, J.; de la Reguera, E.

    2015-12-01

    Anthropogenic production of reactive nitrogen (Nr) has drastically altered the nitrogen cycle over the past few decades by causing it to accumulate in the environment. A nitrogen footprint (NF) estimates the amount of Nr released to the environment as a result of an entity's activities. The Nitrogen Footprint Tool (NFT) for universities and institutions provides a standardized method for quantifying the NF for the activities and operations of these entities. The NFT translates data on energy use, food purchasing, sewage treatment, and fertilizer use to the amount of Nr lost to the environment using NOx and N2O emission factors, virtual nitrogen factors (VNFs) for food production, N reduction rates from wastewater treatment, and nitrogen uptake factors for fertilizer. As part of the Nitrogen Footprint Project supported by the EPA, seven institutions (colleges, universities, and research institutions) have completed NFT assessments: University of Virginia, University of New Hampshire, Brown University, Dickinson College, Colorado State University, Eastern Mennonite University, and the Marine Biological Laboratory. The results of these assessments reveal the magnitude of impacts on the global nitrogen cycle by different activities and sectors, and will allow these institutions to set NF reduction goals along with management decisions based on scenarios and projections in the NFT. The trends revealed in early analysis of the results include geographic differences based on regional energy sources and local sewage treatment, as well as operational differences that stem from institution type and management. As an example of the impact of management, the amount and type of food served directly impacts the food production NF, which is a large percentage of the total NF for all institutions (35-75%). Comparison of these first NF results will shed light on the primary activities of institutions that add Nr to the environment and examine the differences between them.

  6. Comparative results of end colostomy for low rectal cancer using alloplastic material

    Directory of Open Access Journals (Sweden)

    I. G. Gataullin

    2012-01-01

    Full Text Available The results of research on the causes affecting in the development of para-colostomy complications after abdomino-perineal extirpation of the rectum for cancer patients, who were treated by us from 2005 to 2012 found that the development of complications para-colostomy affects in the age of patient, comorbidity, severity of anemia, and obesity. Allocation of risk and patient groups at increased risk for complications allows differentiated approach to their prevention.

  7. Comparing large-scale computational approaches to epidemic modeling: Agent-based versus structured metapopulation models

    Directory of Open Access Journals (Sweden)

    Merler Stefano

    2010-06-01

    Full Text Available Abstract Background In recent years large-scale computational models for the realistic simulation of epidemic outbreaks have been used with increased frequency. Methodologies adapt to the scale of interest and range from very detailed agent-based models to spatially-structured metapopulation models. One major issue thus concerns to what extent the geotemporal spreading pattern found by different modeling approaches may differ and depend on the different approximations and assumptions used. Methods We provide for the first time a side-by-side comparison of the results obtained with a stochastic agent-based model and a structured metapopulation stochastic model for the progression of a baseline pandemic event in Italy, a large and geographically heterogeneous European country. The agent-based model is based on the explicit representation of the Italian population through highly detailed data on the socio-demographic structure. The metapopulation simulations use the GLobal Epidemic and Mobility (GLEaM model, based on high-resolution census data worldwide, and integrating airline travel flow data with short-range human mobility patterns at the global scale. The model also considers age structure data for Italy. GLEaM and the agent-based models are synchronized in their initial conditions by using the same disease parameterization, and by defining the same importation of infected cases from international travels. Results The results obtained show that both models provide epidemic patterns that are in very good agreement at the granularity levels accessible by both approaches, with differences in peak timing on the order of a few days. The relative difference of the epidemic size depends on the basic reproductive ratio, R0, and on the fact that the metapopulation model consistently yields a larger incidence than the agent-based model, as expected due to the differences in the structure in the intra-population contact pattern of the approaches. The age

  8. Comparative analysis of zonal systems for macro-level crash modeling.

    Science.gov (United States)

    Cai, Qing; Abdel-Aty, Mohamed; Lee, Jaeyoung; Eluru, Naveen

    2017-06-01

    Macro-level traffic safety analysis has been undertaken at different spatial configurations. However, clear guidelines for the appropriate zonal system selection for safety analysis are unavailable. In this study, a comparative analysis was conducted to determine the optimal zonal system for macroscopic crash modeling considering census tracts (CTs), state-wide traffic analysis zones (STAZs), and a newly developed traffic-related zone system labeled traffic analysis districts (TADs). Poisson lognormal models for three crash types (i.e., total, severe, and non-motorized mode crashes) are developed based on the three zonal systems without and with consideration of spatial autocorrelation. The study proposes a method to compare the modeling performance of the three types of geographic units at different spatial configurations through a grid based framework. Specifically, the study region is partitioned to grids of various sizes and the model prediction accuracy of the various macro models is considered within these grids of various sizes. These model comparison results for all crash types indicated that the models based on TADs consistently offer a better performance compared to the others. Besides, the models considering spatial autocorrelation outperform the ones that do not consider it. Based on the modeling results and motivation for developing the different zonal systems, it is recommended using CTs for socio-demographic data collection, employing TAZs for transportation demand forecasting, and adopting TADs for transportation safety planning. The findings from this study can help practitioners select appropriate zonal systems for traffic crash modeling, which leads to develop more efficient policies to enhance transportation safety. Copyright © 2017 Elsevier Ltd and National Safety Council. All rights reserved.

  9. A randomized trial comparing TVT with TVT-O: 12-month results.

    Science.gov (United States)

    Rinne, Kirsi; Laurikainen, Eija; Kivelä, Arre; Aukee, Pauliina; Takala, Teuvo; Valpas, Antti; Nilsson, Carl Gustaf

    2008-08-01

    The aim of this randomized clinical trial was to compare the cure rate and the rate of complications of the tension-free vaginal tape (TVT) with those of the tension free vaginal tape obturator (TVT-O) procedure after one year of follow-up. The study was powered to show a ten per cent difference in cure rate and/or rate of complications. Of the initially treated 267 women 134 in the TVT group and 131 in the TVT-O group were evaluated. A cough stress test and a 24 h pad test were used as objective outcome measures. Subjective outcome was assessed by different condition-specific quality of life questionnaires and general health by the EQ-5D questionnaire. Objective cure rate was 95.5% in the TVT patients and 93.1% in TVT-O patients. Subjective cure rates showed significant improvement at one the year follow up in both groups. No significant differences in cure rates between groups were seen. The complication rate was equal in both groups.

  10. Comparing ranibizumab monotherapy and combination with single photodynamic therapy in wet AMD: retreatment and morphologic results.

    Science.gov (United States)

    Hatz, Katja; Schneider, Ulrike; Henrich, Bernhard; Braun, Beatrice; Sacu, Stefan; Prünte, Christian

    2017-06-26

    To evaluate retreatment indications/morphologic responses to ranibizumab monotherapy and combination with verteporfin photodynamic therapy (PDT). A total of 40 patients received 3 monthly intravitreal ranibizumab 0.3 mg injections combined with either PDT or sham PDT at baseline (1:1) followed by as-needed ranibizumab based on predetermined vision/anatomical criteria. Retreatment criteria were visual acuity (VA) loss (59%/58%), central retinal thickness (CRT) increase (27%/26%), or both (14%/16%). One month before retreatment, intraretinal cysts (IRC) were present in 84%/74%, subretinal fluid (SRF) in 70%/63%, and at least one of them in 84%/89% of eyes. A significant decrease in mean leakage area, IRC, and SRF as well as a reduction in presence of hemorrhages and hard exudates occurred in both treatment groups at 12 months (compared to baseline). Retreatment indications were mostly based on VA loss, probably due to the quantitative optical coherence tomography criterion. Intraretinal cysts and SRF were earlier predictors for recurring choroidal neovascularization (CNV) activity than CRT/VA changes. Both treatment strategies were equally potent in reducing CNV activity.

  11. [Tenoxicam (texamen) in the treatment of acute cervicalgia: results of an open comparative trial].

    Science.gov (United States)

    Azimova, Iu E; Tabeeva, G R

    2014-01-01

    Acute cervical pain is one of the most common reasons for a visit to a doctor and temporal disability. We studied efficacy and safety of the nonsteroid anti-inflammatory drug tenoxicam (texamen) in the treatment of acute cervical pain in myofascial syndrome. A trial included 50 people (42 women and 8 men, mean age 42,2±6,8 years) with acute cephalgia. A main group (30 patients) received tenoxicam in dose 20 mg daily in the morning during 7 days with simultaneous therapeutic exercises with elements of postisometric relaxation of cervical muscles. A control group (20 patients) received myorelaxants and massage of a cervical-collar zone. The analgesic effect was more rapid in patients treated with texamen compared to controls. Statistically significant differences were seen in 1-3 days of treatment. In the main group, the analgesic effect long, only 16,6% of patients reported the aggravation of pain in the evening hours during the first day of treatment and 10% in the 2nd day; 23,3% patients of the main group used an additional dose of texamen, another nonsteroid anti-inflammatory drug (ibuprofen) or triptan to stop pain. The introduction of nonsteroid anti-inflammatory drugs, in particular texamen, in the complex treatment of acute cephalgia can significantly reduce pain syndrome.

  12. Comparative study of short term results in two multidrug regimens in multibacillary leprosy.

    Science.gov (United States)

    Singh, R P; Tiwari, V D; Chattopadhyay, S P

    1993-01-01

    Thirty lepromatous and Borderline lepromatous leprosy patients were treated with multidrug therapy in an open trial. Fifteen of them received the standard WHO multidrug regimen ie., rifampicin 600 mg and clofazimine 300 mg monthly, supervised, and dapsone 100 mg daily and clofazimine 100 mg on alternate days as self administered; the other 15 received a modified multidrug therapy regimen comprising of rifampicin 600 mg, clofazimine 100 mg and dapsone 100 mg daily for 21 days as suggested by the Indian Association of Leprologists, followed by the standard WHO regimen. The observation period was six months. Clinical, bacteriological, histological and immunological parameters were studied. The fall in morphological index was much faster in patients receiving modified multidrug therapy regimen compared to those receiving the standard WHO regimen. Otherwise, there was no difference between the two groups of patients. Five patients developed type I (upgrading) reaction with one developing ulnar nerve paralysis. No untoward effects of drugs were noted in the study subjects except for darkening of skin colour of all the patients.

  13. A Comparative Study of Three Methodologies for Modeling Dynamic Stall

    Science.gov (United States)

    Sankar, L.; Rhee, M.; Tung, C.; ZibiBailly, J.; LeBalleur, J. C.; Blaise, D.; Rouzaud, O.

    2002-01-01

    During the past two decades, there has been an increased reliance on the use of computational fluid dynamics methods for modeling rotors in high speed forward flight. Computational methods are being developed for modeling the shock induced loads on the advancing side, first-principles based modeling of the trailing wake evolution, and for retreating blade stall. The retreating blade dynamic stall problem has received particular attention, because the large variations in lift and pitching moments encountered in dynamic stall can lead to blade vibrations and pitch link fatigue. Restricting to aerodynamics, the numerical prediction of dynamic stall is still a complex and challenging CFD problem, that, even in two dimensions at low speed, gathers the major difficulties of aerodynamics, such as the grid resolution requirements for the viscous phenomena at leading-edge bubbles or in mixing-layers, the bias of the numerical viscosity, and the major difficulties of the physical modeling, such as the turbulence models, the transition models, whose both determinant influences, already present in static maximal-lift or stall computations, are emphasized by the dynamic aspect of the phenomena.

  14. Psychobiological model of temperament and character: Validation and cross-cultural comparations

    Directory of Open Access Journals (Sweden)

    Džamonja-Ignjatović Tamara

    2005-01-01

    Full Text Available The paper presents research results regarding Psychobiological model of personality by Robert Cloninger. The primary research goal was to test the new TCI-5 inventory and compare our results with US normative data. We also analyzed the factor structure of the model and the reliability of basic TCI-5 scales and sub-scales. The sample consisted of 473 subjects from the normal population, age range between 18-50 years. Results showed significant differences between Serbian and American samples. Compared to the American sample, Novelty seeking was higher in the Serbian sample, while Persistence Self-directedness and Cooperativeness were lower. For the most part results of the present study confirmed a seven factor structure model although some sub-scales did not coincide with basic dimensions as predicted by the theoretical model. Therefore certain theoretical revisions of the model are required in order to fit in the empirical findings. Similarly, the discrepancy between the theoretical and empirical was also noticed regarding the reliability of TCI-5 scales. They also need to be re-examined. Thus the results of the study showed satisfactory reliability of Persistence (.90, Self-directedness (.89 and Harm avoidance (.87, but low reliability of the Novelty seeking (.78, Reward dependence (.79 and Self-transcendence (.78.

  15. Ten year results of a randomised trial comparing two conservative treatment strategies for small size breast cancer

    International Nuclear Information System (INIS)

    Mariani, L.; Salvadori, B.; Marubini, E.; Conti, A.R.; Rovini, D.; Cusumano, F.; Rosolin, T.; Andreola, S.; Zucali, R.; Rilke, F.; Veronesi, U.

    1998-01-01

    We report the 10-year results of a randomised clinical trial in which two different breast conservation treatment strategies were compared in women with small, non-metastatic primary breast cancer: quadrantectomy, axillary dissection and radiotherapy (QUART) versus tumorectomy and axillary dissection followed by external radiotherapy and a boost with 192 Ir implantation (TART). No second surgery was given to women with affected surgical margins. Axillary node positive women received adjuvant medical therapy. From 1985-1987, this trial accrued 705 patients, 360 in the QUART and 345 in the TART arm. Crude cumulative incidence curves for intrabreast tumour recurrence (IBTR) and metastases as first events and mortality curves in each of the two treatment arms were computed. A crude cumulative incidence curve of IBTR as a second event (in women who had already had a local recurrence) was also computed. The two groups were compared in terms of hazard for IBTR, metastases or death occurrence by using Cox regression models, both with and without adjustment for patient age, tumour size, number of metastatic axillary nodes and histology. Possible interactions between the aforementioned prognostic factors and the type of surgery were also investigated. The two groups were well matched for baseline patient and tumour characteristics, the only exception being resection margins, which were more often positive in the TART group. At the Cox model, a significant difference between groups was detected for IBTR (P<0.0001), but not for distant metastases and overall survival. In particular, 5- and 10-year estimates of crude cumulative incidence of IBTR were 4.7 and 7.4% in the QUART group, and 11.6 and 18.6% in the TART group. The difference was not substantially affected by patient or disease characteristics. Likewise, the status of resection margins in women who underwent TART treatment did not significantly influence the risk of occurrence of IBTRs. Finally, the rate of second IBTR

  16. Senior student nurse proficiency: A comparative study of two clinical immersion models.

    Science.gov (United States)

    Kumm, Sharon; Godfrey, Nelda; Richards, Veronica; Hulen, Jennifer; Ray, Kristin

    2016-09-01

    This study focused on identifying the best clinical learning model that would support nursing practice readiness following each immersion experience. Practicum preceptors completed surveys in which evaluated student preparation/readiness by assessing clinical knowledge, technical skills, critical thinking, communication, professionalism, management of responsibilities, and overall performance. The study results yielded no statistical significance when comparing both models. Future research is needed to analyze the impact of clinical hours offered in the senior immersion experience along with the curriculum content differences among various models of clinical experiences in undergraduate nursing programs to ensure practice readiness of nursing graduates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. A comparative study of spherical and flat-Earth geopotential modeling at satellite elevations

    Science.gov (United States)

    Parrott, M. H.; Hinze, W. J.; Braile, L. W.

    1985-01-01

    Flat-Earth and spherical-Earth geopotential modeling of crustal anomaly sources at satellite elevations are compared by computing gravity and scalar magnetic anomalies perpendicular to the strike of variably dimensioned rectangular prisms at altitudes of 150, 300, and 450 km. Results indicate that the error caused by the flat-Earth approximation is less than 10% in most geometric conditions. Generally, error increase with larger and wider anomaly sources at higher altitudes. For most crustal source modeling applications at conventional satellite altitudes, flat-Earth modeling can be justified and is numerically efficient.

  18. Dermal uptake of phthalates from clothing: comparison of model to human participant results

    DEFF Research Database (Denmark)

    Morrison, Glenn; Weschler, Charles J.; Bekö, Gabriel

    2016-01-01

    In this research, we extend a model of transdermal uptake of phthalates to include a layer of clothing. When compared with experimental results, this model better estimates dermal uptake of diethylphthalate (DEP) and di-n-butylphthalate (DnBP) than a previous model. It also demonstrates that uptake...... is sensitive to both the gap between skin and clothing and the time clothing is allowed to adsorb phthalates. The model predictions are consistent with the observation that exposed clothing increases dermal uptake when compared with uptake observed in bare-skin participants. Extension of this model beyond...... the cotton-phthalate system will be challenging until data on partition coefficients are quantified for other combinations of SVOCs, fabric materials and environmental conditions....

  19. The use of the k - {epsilon} turbulence model within the Rossby Centre regional ocean climate model: parameterization development and results

    Energy Technology Data Exchange (ETDEWEB)

    Markus Meier, H.E. [Swedish Meteorological and Hydrological Inst., Norrkoeping (Sweden). Rossby Centre

    2000-09-01

    As mixing plays a dominant role for the physics of an estuary like the Baltic Sea (seasonal heat storage, mixing in channels, deep water mixing), different mixing parameterizations for use in 3D Baltic Sea models are discussed and compared. For this purpose two different OGCMs of the Baltic Sea are utilized. Within the Swedish regional climate modeling program, SWECLIM, a 3D coupled ice-ocean model for the Baltic Sea has been coupled with an improved version of the two-equation k - {epsilon} turbulence model with corrected dissipation term, flux boundary conditions to include the effect of a turbulence enhanced layer due to breaking surface gravity waves and a parameterization for breaking internal waves. Results of multi-year simulations are compared with observations. The seasonal thermocline is simulated satisfactory and erosion of the halocline is avoided. Unsolved problems are discussed. To replace the controversial equation for dissipation the performance of a hierarchy of k-models has been tested and compared with the k - {epsilon} model. In addition, it is shown that the results of the mixing parameterization depend very much on the choice of the ocean model. Finally, the impact of two mixing parameterizations on Baltic Sea climate is investigated. In this case the sensitivity of mean SST, vertical temperature and salinity profiles, ice season and seasonal cycle of heat fluxes is quite large.

  20. Agility training in young elite soccer players: promising results compared to change of direction drills.

    Science.gov (United States)

    Chaalali, A; Rouissi, M; Chtara, M; Owen, A; Bragazzi, N L; Moalla, W; Chaouachi, A; Amri, M; Chamari, K

    2016-12-01

    The aim of this study was to compare the effect of two different training programmes - change of direction (COD) vs. agility (AG) - on straight sprint (SS), COD and AG test performances in young elite soccer players. Thirty-two soccer players (age: 14.5±0.9 years; height: 171.2±5.1 cm; body mass: 56.4±7.1 kg, body fat: 10.3±2.3%) participated in a short-term (6 weeks) training study. Players were randomly assigned to two experimental groups - training with change of direction drills (COD-G, n=11) or using agility training (AG-G, n= 11) - and to a control group (CON-G, n=10). All players completed the following tests before and after training: straight sprint (15m SS), 15 m agility run with (15m-AR-B) and without a ball (15m-AR), 5-0-5 agility test, reactive agility test (RAT), and RAT test with ball (RAT-B). A significant group effect was observed for all tests (pagility test, COD-G improved significantly more (5.41%; ES=1.15 and 3.41; ES=0.55 respectively) than AG-G (3.65%; ES=1.05 and 2.24; ES=0.35 respectively) and CON-G (1.62%; ES=0.96 and 0.97; ES=0.19 respectively). Improvements in RAT and RAT-B were larger (9.37%; ES=2.28 and 7.73%; ES=2.99 respectively) in RAT-G than the other groups. In conclusion, agility performance amongst young elite soccer could be improved using COD training. Nevertheless, including a conditioning programme for agility may allow a high level of athletic performance to be achieved.

  1. Flexible Graduate is Successful Graduate. Key Factors of Successful Job Interview, Results of a Comparative Analysis

    Directory of Open Access Journals (Sweden)

    Vendolska Iva

    2016-06-01

    Full Text Available The conditions on the labour market have changed dramatically in the last twenty years and the importance of human resources has increased. A company has to find, keep, and educate those workers who are able to adapt quickly to changes in the market. Such a company is then able to innovate constantly, which ensures its long-term competitiveness. Moreover, after finishing their education young people experience problems when seeking suitable employment. University graduates face stronger competition from other graduates when seeking employment. This target risk group of university graduates in particular is included in the primary research, together with the other side of the labour market, employers. The importance of individual criteria that are pivotal for employers during job interviews was examined on the basis of an anonymous questionnaire. 18 criteria were assessed and compared on a scale from 1 to 5. The correlation between the rate of importance of the given criterion and the group of respondents was tested. It was discovered that the criterion employers consider the most important is the flexibility and adaptability of a job candidate. This criterion is followed by willingness to learn, loyalty, and self-reliance. Those considered least important were these criteria: a stay abroad, courses/certificates, and studying at a particular university. On the other hand, the students consider the most important criteria to be foreign language skills, followed by communication skills, and willingness to learn and an internship during their studies. The criteria that were seen as the most important were: self-confidence, experience of a stay abroad, and the particular university that the student graduated from. The most significant difference in the assessment of the criteria between the employers and students was identified as being an internship during one’s studies.

  2. Summary of comparative results integrated nonthermal treatment and integrated thermal treatment systems studies

    International Nuclear Information System (INIS)

    1996-12-01

    In July 1994, the Idaho National Engineering Laboratory (INEL), under a contract from U.S. Department of Energy's (DOE) Environment Management Office of Science and Technology (OST, EM-50) published a report entitled open-quotes Integrated Thermal Treatment System Study - Phase 1 Resultsclose quotes (EGG-MS-11211). This report was the culmination of over a year of analysis involving scientists and engineers within the DOE complex and from private industry. The purpose of that study was open-quotes to conduct a systematic engineering evaluation of a variety of mixed low level waste (MLLW) treatment system alternatives.close quotes The study also open-quotes identified the research and development, demonstrations, and testing and evaluation needed to assure unit operability in the most promising alternative system.close quotes This study evaluated ten primary thermal treatment technologies, organized into complete open-quotes cradle-to-graveclose quotes systems (including complete engineering flow sheets), to treat DOE MLLW and calculated mass balances and 20-year total life cycle costs (TLCC) for all systems. The waste input used was a representative heterogenous mixture of typical DOE MLLW. An additional study was conducted, and then, based on response to these studies, additional work was started to investigate and evaluate non-thermal treatment options on a footing comparable to the effort devoted to thermal options. This report attempts to present a summary overview of the thermal and non-thermal treatment technologies which were examined in detail in the process of the above mentioned reviews

  3. Results of EPRI/ANL DCH investigations and model development

    International Nuclear Information System (INIS)

    Spencer, B.W.; Sienicki, J.J.; Sehgal, B.R.; Merilo, M.

    1988-01-01

    The results of a series of five experiments are described addressing the severity and mitigation of direct containment heating. The tests were performed in a 1:30 linear scale mockup of the Zion PWR containment system using a reactor-material corium melt consisting of 60% UO 2 , 16% ZrO 2 , 24% SSt at nominally 2800C initial temperature. A ''worst-case'' type test involving unimpeded corium dispersal through an air atmosphere in a closed vessel produced an atmosphere heatup of 323K, equivalent to a DCH efficiency of 62%. With the addition of structural features which impeded the corium dispersal, representative of dispersal pathway features at Zion, the DCH efficiency was reduced to 1--5%. (This important result is scale dependent and requires larger scale tests such as the SURTSEY program at SNL plus mechanistic modeling for application to the reactor system.) With the addition of water in the cavity region, there was no measurable heatup of the atmosphere. This was attributable to the vigorous codispersal of water with corium which prevented the temperature of the atmosphere from significantly exceeding T/sub sat/. In this case the DCH load was replaced by the more benign ''steam spike'' from corium quench. Significant oxidation of the corium constituents occurred in the tests, adding chemical energy to the system and producing hydrogen. Overall, the results suggest that with consideration of realistic, plant specific, mitigating features, DCH may be no worse and possibly far less severe than the previously examined steam spike. Implications for accident management are addressed. 17 refs., 7 figs., 4 tabs

  4. Results and Comparison from the SAM Linear Fresnel Technology Performance Model: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, M. J.

    2012-04-01

    This paper presents the new Linear Fresnel technology performance model in NREL's System Advisor Model. The model predicts the financial and technical performance of direct-steam-generation Linear Fresnel power plants, and can be used to analyze a range of system configurations. This paper presents a brief discussion of the model formulation and motivation, and provides extensive discussion of the model performance and financial results. The Linear Fresnel technology is also compared to other concentrating solar power technologies in both qualitative and quantitative measures. The Linear Fresnel model - developed in conjunction with the Electric Power Research Institute - provides users with the ability to model a variety of solar field layouts, fossil backup configurations, thermal receiver designs, and steam generation conditions. This flexibility aims to encompass current market solutions for the DSG Linear Fresnel technology, which is seeing increasing exposure in fossil plant augmentation and stand-alone power generation applications.

  5. Comparing large-scale computational approaches to epidemic modeling: agent-based versus structured metapopulation models.

    Science.gov (United States)

    Ajelli, Marco; Gonçalves, Bruno; Balcan, Duygu; Colizza, Vittoria; Hu, Hao; Ramasco, José J; Merler, Stefano; Vespignani, Alessandro

    2010-06-29

    In recent years large-scale computational models for the realistic simulation of epidemic outbreaks have been used with increased frequency. Methodologies adapt to the scale of interest and range from very detailed agent-based models to spatially-structured metapopulation models. One major issue thus concerns to what extent the geotemporal spreading pattern found by different modeling approaches may differ and depend on the different approximations and assumptions used. We provide for the first time a side-by-side comparison of the results obtained with a stochastic agent-based model and a structured metapopulation stochastic model for the progression of a baseline pandemic event in Italy, a large and geographically heterogeneous European country. The agent-based model is based on the explicit representation of the Italian population through highly detailed data on the socio-demographic structure. The metapopulation simulations use the GLobal Epidemic and Mobility (GLEaM) model, based on high-resolution census data worldwide, and integrating airline travel flow data with short-range human mobility patterns at the global scale. The model also considers age structure data for Italy. GLEaM and the agent-based models are synchronized in their initial conditions by using the same disease parameterization, and by defining the same importation of infected cases from international travels. The results obtained show that both models provide epidemic patterns that are in very good agreement at the granularity levels accessible by both approaches, with differences in peak timing on the order of a few days. The relative difference of the epidemic size depends on the basic reproductive ratio, R0, and on the fact that the metapopulation model consistently yields a larger incidence than the agent-based model, as expected due to the differences in the structure in the intra-population contact pattern of the approaches. The age breakdown analysis shows that similar attack rates are

  6. Anatomy of the Andean subduction zone: three-dimensional density model upgraded and compared against global-scale models

    Science.gov (United States)

    Tassara, Andrés.; Echaurren, Andrés.

    2012-04-01

    We present an upgraded version of a previously published 3-D density model of the Andean subduction zone between 18°S and 45°S. This model consists of 3-D bodies of constant density, which geometry is constrained by independent seismic data and is triangulated from vertical cross-sections. These bodies define the first-order morphology and internal structure of the subducted Nazca slab and South American Plate. The new version of the density model results after forward modelling the Bouguer anomaly as computed from the most recent version of the Earth Gravitational Model (EGM2008). The 3-D density model incorporates new seismic information to better constrain the geometry of the subducted slab and continental Moho (CMH) and has a trench-parallel resolution doubling the resolution of the previous model. As an example of the potential utility of our model, we compare the geometry of the subducted slab and CMH against the corresponding global models Slab1.0 and Crust2.0, respectively. This exercise demonstrates that, although global models provide a good first-order representation of the slab and upper-plate crustal geometries, they show large discrepancies (up to ±40 km) with our upgraded model for some well-constrained areas. The geometries of the slab, lithosphere-asthenosphere boundary below the continent, CMH and intracrustal density discontinuity that we present here as Supporting Information can be used to study Andean geodynamic processes from a wide range of quantitative approaches.

  7. ANITA Air Monitoring on the International Space Station: Results Compared to Other Measurements

    Science.gov (United States)

    Honne, A.; Schumann-Olsen, H.; Kaspersen, K.; Limero, T.; Macatangay, A.; Mosebach, H.; Kampf, D.; Mudgett, P. D.; James, J. T.; Tan, G.; hide

    2009-01-01

    ANITA (Analysing Interferometer for Ambient Air) is a flight experiment precursor for a permanent continuous air quality monitoring system on the ISS (International Space Station). For the safety of the crew, ANITA can detect and quantify quasi-online and simultaneously 33 gas compounds in the air with ppm or sub-ppm detection limits. The autonomous measurement system is based on FTIR (Fourier Transform Infra-Red spectroscopy). The system represents a versatile air quality monitor, allowing for the first time the detection and monitoring of trace gas dynamics in a spacecraft atmosphere. ANITA operated on the ISS from September 2007 to August 2008. This paper summarizes the results of ANITA s air analyses with emphasis on comparisons to other measurements. The main basis of comparison is NASA s set of grab samples taken onboard the ISS and analysed on ground applying various GC-based (Gas Chromatography) systems.

  8. Comparative study on the results of consecutive oral cholecystography and intravenous cholangiography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung Hee; Park, Yang Ok; Yoo, Ho Joon [Korea General Hospital, Seoul (Korea, Republic of)

    1974-04-15

    Since its introduction in 1924, oral cholecystography has been used as a screening method in the diagnosis of the gallbladder disease. Recently, intravenous cholangiography has become a most valuable method in the diagnosis of biliary tract pathology because of its advantage of simultaneous visualization of the gallbladder and bile ducts in a short time. However, opinions vary considerably as to the significance of nonvisualization of the gallbladder with oral cholecystography. In attempt to evaluate how much intravenous cholangiography does contribute to the diagnosis in the cases that the gallbladder cannot be opacified or can only faintly visualized by the oral method, we have made a clinical observation in 168 patients, in whom intravenous cholangiography had been performed within a week following oral cholecystography, at Korea General Hospital during the last three years from January 1969 to December 1971. The results obtained are summarized as follows; 1. The results of oral cholecystography in 168 cases were as follow; well opacification of the gallbladder in 10 cases, faint opacification in 46 cases and nonopacification in 112 cases. 2. In 37.5% (42 cases) of 112 gallbladder not opacified by the oral method, the gallbladder was subsequently opacified by the intravenous method, and 11.6% (14 cases) turned out to be normal when examined by the intravenous method. 3. Further demonstration of abnormalities could be obtained with the aid intravenous cholangiography in 28 cases (16.6%); cholelithiasis in 12 cases and choledocholithiasis in 16 cases. 4. In every cases of 14 patients whose gallbladder were virtually not opacified by both oral and intravenous methods bit the common bile ducts could be opacified by intravenous cholangiography, definite abnormalities were identified in the gallbladder at surgery.

  9. THE MOTOR LEARNING, MEMORY, KNOWLEDGE OF RESULTS: COMPARATIVE ANALYSIS OF HOMOGENEOUS GROUPS

    Directory of Open Access Journals (Sweden)

    Francesco Perrotta

    2009-12-01

    Full Text Available There is ample experimental evidence of the positive-fixing motor task of having both a lower relativefrequency (FR which is provided with the knowledge of the result (CR to the subject of learning, The outcomeof the response, both the application of the formulation of a subjective estimate of first CR (SS.It 'was, however, suggested the possibility of an interaction between these two variables,meaning thatthe individual, when he has to make an estimate subjective error, would benefit from greater FR. Taking up aninteresting research is shown in a dissertation in Physiotherapy (Giulia Days 2000/01 Which is credited withhaving carried out a rigorous investigation and Articles The authors of this paper have wanted to see exactlyProposing given to 60 young subjects, righthanded and in good health, and the same working hypothesis, butwith a different device (Biodex System 4: a simple right elbow flexion with isokinetic contraction at 30 degrees/ second. Subjects were asked:1 to Assess Whether or not the mistake made after the end of the year,2 CR was provided after each trial (100% FR, or after a trial every five (20% FR3 to mark the difference between the subjects who did not Had Gold SS to make an the latter was askedimmediately after the conclusion of the trial, of perform a simple calculation. All subjects performed 20 sets of10 repetitions each during a single session of practice. The next day was made a test of retention (consisting of 1 set of 15 repetitions without CR or SS The comparison between the groups at the retention test was performed with Analysis of variance, before and after adjustment for the initial conditions. The results showed that afteradjustment the group of subjects who received the CR with 100% FR and formulation of SS during the period of practice, a test of retention in a Significantly better.

  10. A Duality Result for the Generalized Erlang Risk Model

    Directory of Open Access Journals (Sweden)

    Lanpeng Ji

    2014-11-01

    Full Text Available In this article, we consider the generalized Erlang risk model and its dual model. By using a conditional measure-preserving correspondence between the two models, we derive an identity for two interesting conditional probabilities. Applications to the discounted joint density of the surplus prior to ruin and the deficit at ruin are also discussed.

  11. Comparative Mineralogy of Comets and Exo-Systems Using the Deep Impact Results

    Science.gov (United States)

    Lisse, Carey M.

    2006-09-01

    We have used the infrared mineralogical model derived from the Spitzer IRS observations of the Deep Impact experiment to study the nature of the dust in the cometary systems 9P/Tempel 1 (Lisse et al. 2006), C/Hale-Bopp 1995 O1 (Crovisier et al. 1997), 73P/Schwassmann-Wachmann 3 (Sitko et al. 2007), and 29P/Schwassmann-Wachmann 1 (Stansberry et al. 2004), the YSO HD100546 (Malfait et al. 1998), and the debris disk found around the K0V star HD69830 (Beichman et al. 2005). The comets show common emission signatures due to silicates, carbonates, water ice, amorphous carbon, and sulfides. There are differences - unlike Tempel 1, no Fe-rich olivines or polycyclic aromatic hydrocarbons (PAHs) are found in Hale-Bopp, while HD100546 is lacking in carbonates and phyllosilicates but does demonstrate a huge PAH feature. The dust from SW1 and SW3 is much less crystalline, 30%, and does not show strong evidence for phyllosilicates. Located beyond the ice line, SW1 and Hale-Bopp emitted copious amounts of water ice, SW3 at 1.47 AU emitted only water gas. The material around HD100546 appears to be very fresh, rich in PAHs and amorphous silicates; that incorporated into Hale-Bopp, SW1, and SW3 to be middle aged; and that incorporated into Tempel 1 to be mature. Lacking in carbonaceous and ferrous materials but including small, icy, ephemeral grains, the composition of the HD 69830 dust resembles that of a disrupted P or D-type asteroid. The amount of mass responsible for the observed emission is the equivalent of a 6 km radius, 2500 kg m-3 sphere, while the effective temperature of the dust implies that the bulk of the observed material is at 0.5 AU from the central source, between the second and third Neptune-sized planets. The ephemeral nature of the dust implies that ongoing collisional fragmentation is occurring.

  12. Comparative analysis of hourly and dynamic power balancing models for validating future energy scenarios

    DEFF Research Database (Denmark)

    Pillai, Jayakrishnan R.; Heussen, Kai; Østergaard, Poul Alberg

    2011-01-01

    , the model is verified on the basis of the existing energy mix on Bornholm as an islanded energy system. Future energy scenarios for the year 2030 are analysed to study a feasible technology mix for a higher share of wind power. Finally, the results of the hourly simulations are compared to dynamic frequency...... simulations incorporating the Vehicle-to-grid technology. The results indicate how the EnergyPLAN model may be improved in terms of intra-hour variability, stability and ancillary services to achieve a better reflection of energy and power capacity requirements....

  13. Microbial comparative pan-genomics using binomial mixture models

    DEFF Research Database (Denmark)

    Ussery, David; Snipen, L; Almøy, T

    2009-01-01

    The size of the core- and pan-genome of bacterial species is a topic of increasing interest due to the growing number of sequenced prokaryote genomes, many from the same species. Attempts to estimate these quantities have been made, using regression methods or mixture models. We extend the latter...... occurring genes in the population. CONCLUSION: Analyzing pan-genomics data with binomial mixture models is a way to handle dependencies between genomes, which we find is always present. A bottleneck in the estimation procedure is the annotation of rarely occurring genes....

  14. Energy modeling and comparative assessment beyond the market

    International Nuclear Information System (INIS)

    Rogner, H.-H.; Langlois, L.; McDonald, A.; Jalal, I.

    2004-01-01

    Market participants engage in constant comparative assessment of prices, available supplies, consumer options. Such implicit comparative assessment is a sine qua non for decision making in, and the smooth function of, competitive markets, but it is not always sufficient for policy makers who make decisions based on priorities other than or in addition to market prices. Supplementary mechanisms are needed to make explicit, to expose for consideration and to incorporate into their decision making processes, broader factors that are not necessarily reflected directly in the market price of a good or service. These would include, for example, employment, environment, national security or trade considerations. They would include long-term considerations, e.g., global warming or greatly diminished future supplies of oil and gas. This paper explores different applications of comparative assessment beyond the market, reviews different approaches for accomplishing such evaluations, and presents some tools available for conducting various types of extra-market comparative assessment, including those currently in use by Member States of the IAEA.(author)

  15. The desmoid tumour: Therapeutic results of surgical intervention as compared to those achieved with radiotherapy

    International Nuclear Information System (INIS)

    Weindler, J.

    1983-01-01

    Discussion of the case reports of nine patients treated for desmoid tumours in the light of 62 such cases described in the relevant literature between 1975 and 1979. Among the patients analysed for the purposes of this study 9 had desmoid tumours treated at our clinic, while the other 60 cases were described in the relevant literature of the past 5 years. The methods used in this cohort were surgery for 37 patients, radiation for 20 patients, excision and post-surgical radiation for 5 patients and various other treatments for the remaining cases. Careful analysis and assessment of the results led to the conclusion that the vast majority of desmoids can be expected to show a satisfactory response to radiation, even though no clear therapeutic superiority could be established for either radical excision or radiation. If surgery is chosen, this should be carried out with the aim of removing all of the tumour. In circumstances precluding radical excision it appears wise to use post-surgical radiation. Follow-up examinations should be carried out in all patients so as to permit immediate diagnosis and treatment of any recurrent tumours. Each desmoid tumour is to be treated on an individual basis. In small tumours it is safer to remove not only the lesion itself but also some of the surrounding intact tissue, tumours at a more advanced stage should be subjected to radiation or both surgery and subsequent radiotherapy. (orig./MG) [de

  16. Waste glass corrosion modeling: Comparison with experimental results

    International Nuclear Information System (INIS)

    Bourcier, W.L.

    1994-01-01

    Models for borosilicate glass dissolution must account for the processes of (1) kinetically-controlled network dissolution, (2) precipitation of secondary phases, (3) ion exchange, (4) rate-limiting diffusive transport of silica through a hydrous surface reaction layer, and (5) specific glass surface interactions with dissolved cations and anions. Current long-term corrosion models for borosilicate glass employ a rate equation consistent with transition state theory embodied in a geochemical reaction-path modeling program that calculates aqueous phase speciation and mineral precipitation/dissolution. These models are currently under development. Future experimental and modeling work to better quantify the rate-controlling processes and validate these models are necessary before the models can be used in repository performance assessment calculations

  17. Comparing observed and modelled growth of larval herring (Clupea harengusz: Testing individual-based model parameterisations

    Directory of Open Access Journals (Sweden)

    Helena M. Hauss

    2009-10-01

    Full Text Available Experiments that directly test larval fish individual-based model (IBM growth predictions are uncommon since it is difficult to simultaneously measure all relevant metabolic and behavioural attributes. We compared observed and modelled somatic growth of larval herring (Clupea harengus in short-term (50 degree-day laboratory trials conducted at 7 and 13°C in which larvae were either unfed or fed ad libitum on different prey sizes (~100 to 550 µm copepods, Acartia tonsa. The larval specific growth rate (SGR, % DW d-1 was generally overestimated by the model, especially for larvae foraging on large prey items. Model parameterisations were adjusted to explore the effect of 1 temporal variability in foraging of individuals, and 2 reduced assimilation efficiency due to rapid gut evacuation at high feeding rates. With these adjustments, the model described larval growth well across temperatures, prey sizes, and larval sizes. Although the experiments performed verified the growth model, variability in growth and foraging behaviour among larvae shows that it is necessary to measure both the physiology and feeding behaviour of the same individual. This is a challenge for experimentalists but will ultimately yield the most valuable data to adequately model environmental impacts on the survival and growth of marine fish early life stages.

  18. Comparing the performance of species distribution models of

    NARCIS (Netherlands)

    Valle , M.; van Katwijk, M.M.; de Jong, D.J.; Bouma, T.; Schipper, A.M.; Chust, G.; Benito, B.M.; Garmendia, J.M.; Borja, A.

    2013-01-01

    Intertidal seagrasses show high variability in their extent and location, with local extinctions and (re-)colonizations being inherent in their population dynamics. Suitable habitats are identified usually using Species Distribution Models (SDM), based upon the overall distribution of the species;

  19. Modeling blood pressure: Comparative study of seemingly unrelated ...

    African Journals Online (AJOL)

    Most authors have focused on Systolic Blood Pressure(SBP) and Diastolic Blood Pressure(DBP) separately. The effect of some identified risk factors on SBP and DBP can be estimated separately since they are affected by different factors.This study is aimed at developing a model that can appropriately capture the ...

  20. A Mathematical Model for the Comparative Study of the Blast ...

    African Journals Online (AJOL)

    This paper presents a mathematical model of the study of the blast response of aluminium and steel panels. These panels are deemed sufficient to provided protective barrier against explosions, especially from terrorists. With the maximum deflection being the damage criteria used, the behaviour of both panel is studied.

  1. Comparing State SAT Scores Using a Mixture Modeling Approach

    Science.gov (United States)

    Kim, YoungKoung Rachel

    2009-01-01

    Presented at the national conference for AERA (American Educational Research Association) in April 2009. The large variability of SAT taker population across states makes state-by-state comparisons of the SAT scores challenging. Using a mixture modeling approach, therefore, the current study presents a method of identifying subpopulations in terms…

  2. A comparative study of explicit and implicit modelling of ...

    Indian Academy of Sciences (India)

    tion to the state-of-the-art vocal tract features. The contribution of the explicit features is relatively more robust against noise. We suggest that the explicit approach can be used to model the subsegmental excitation information for speaker recognition. Keywords. Speaker-specific excitation source information; subsegmental; ...

  3. comparative analysis of path loss prediction models for urban

    African Journals Online (AJOL)

    A. Obota, O. Simeonb, J. Afolayanc. Department of Electrical/Electronics & Computer Engineering, University of Uyo, Akwa. Ibom State .... assignments, proper determination of electric field strength, interference analysis, handover .... model based on extensive drive test measure- ments made in Japan at several frequencies.

  4. Classifying and comparing spatial models of fire dynamics

    Science.gov (United States)

    Geoffrey J. Cary; Robert E. Keane; Mike D. Flannigan

    2007-01-01

    Wildland fire is a significant disturbance in many ecosystems worldwide and the interaction of fire with climate and vegetation over long time spans has major effects on vegetation dynamics, ecosystem carbon budgets, and patterns of biodiversity. Landscape-Fire-Succession Models (LFSMs) that simulate the linked processes of fire and vegetation development in a spatial...

  5. Locating Pleistocene Refugia: Comparing Phylogeographic and Ecological Niche Model Predictions

    Science.gov (United States)

    2007-07-01

    how well ‘back- casting ’ of ecological niche models can complement phylogeo- graphic approaches in identifying refugia. A clear advantage of the ENM...records: a test case using cryptic geckos in Madagascar. Journal of Biogeography 34: 102–117. 47. Araújo MB, Whittaker RJ, Ladle RJ, Erhard M (2005

  6. Nature of Science and Models: Comparing Portuguese Prospective Teachers' Views

    Science.gov (United States)

    Torres, Joana; Vasconcelos, Clara

    2015-01-01

    Despite the relevance of nature of science and scientific models in science education, studies reveal that students do not possess adequate views regarding these topics. Bearing in mind that both teachers' views and knowledge strongly influence students' educational experiences, the main scope of this study was to evaluate Portuguese prospective…

  7. Argonne Fuel Cycle Facility ventilation system -- modeling and results

    International Nuclear Information System (INIS)

    Mohr, D.; Feldman, E.E.; Danielson, W.F.

    1995-01-01

    This paper describes an integrated study of the Argonne-West Fuel Cycle Facility (FCF) interconnected ventilation systems during various operations. Analyses and test results include first a nominal condition reflecting balanced pressures and flows followed by several infrequent and off-normal scenarios. This effort is the first study of the FCF ventilation systems as an integrated network wherein the hydraulic effects of all major air systems have been analyzed and tested. The FCF building consists of many interconnected regions in which nuclear fuel is handled, transported and reprocessed. The ventilation systems comprise a large number of ducts, fans, dampers, and filters which together must provide clean, properly conditioned air to the worker occupied spaces of the facility while preventing the spread of airborne radioactive materials to clean am-as or the atmosphere. This objective is achieved by keeping the FCF building at a partial vacuum in which the contaminated areas are kept at lower pressures than the other worker occupied spaces. The ventilation systems of FCF and the EBR-II reactor are analyzed as an integrated totality, as demonstrated. We then developed the network model shown in Fig. 2 for the TORAC code. The scope of this study was to assess the measured results from the acceptance/flow balancing testing and to predict the effects of power failures, hatch and door openings, single-failure faulted conditions, EBR-II isolation, and other infrequent operations. The studies show that the FCF ventilation systems am very controllable and remain stable following off-normal events. In addition, the FCF ventilation system complex is essentially immune to reverse flows and spread of contamination to clean areas during normal and off-normal operation

  8. ExEP yield modeling tool and validation test results

    Science.gov (United States)

    Morgan, Rhonda; Turmon, Michael; Delacroix, Christian; Savransky, Dmitry; Garrett, Daniel; Lowrance, Patrick; Liu, Xiang Cate; Nunez, Paul

    2017-09-01

    EXOSIMS is an open-source simulation tool for parametric modeling of the detection yield and characterization of exoplanets. EXOSIMS has been adopted by the Exoplanet Exploration Programs Standards Definition and Evaluation Team (ExSDET) as a common mechanism for comparison of exoplanet mission concept studies. To ensure trustworthiness of the tool, we developed a validation test plan that leverages the Python-language unit-test framework, utilizes integration tests for selected module interactions, and performs end-to-end crossvalidation with other yield tools. This paper presents the test methods and results, with the physics-based tests such as photometry and integration time calculation treated in detail and the functional tests treated summarily. The test case utilized a 4m unobscured telescope with an idealized coronagraph and an exoplanet population from the IPAC radial velocity (RV) exoplanet catalog. The known RV planets were set at quadrature to allow deterministic validation of the calculation of physical parameters, such as working angle, photon counts and integration time. The observing keepout region was tested by generating plots and movies of the targets and the keepout zone over a year. Although the keepout integration test required the interpretation of a user, the test revealed problems in the L2 halo orbit and the parameterization of keepout applied to some solar system bodies, which the development team was able to address. The validation testing of EXOSIMS was performed iteratively with the developers of EXOSIMS and resulted in a more robust, stable, and trustworthy tool that the exoplanet community can use to simulate exoplanet direct-detection missions from probe class, to WFIRST, up to large mission concepts such as HabEx and LUVOIR.

  9. Comparing the results of DAADD and ABC of children included in autism spectrum disorders.

    Science.gov (United States)

    Barbosa, Milene Rossi Pereira; Fernandes, Fernanda Dreux Miranda

    2014-01-01

    To verify if there are characteristic behaviors of the different diagnosis included in the autism spectrum according to the Differential Assessment of Autism and Other Developmental Disorders (DAADD) and to the Autism Behavior Checklist (ABC). Participants were 45 individuals and their respective speech-language therapists. All therapists are graduate students working with the children for at least 1 year. This time was considered sufficient to the therapists to have the information required by the DAADD questionnaire. It is comprised by 3 protocols specifically designed to children with 2 to 4 years, 4 to 6 years and 6 to 8 years, the same criteria used to separate the research groups, G1, G2 and G3, respectively. Data referring to the ABC were retrieved from the subject's files at the Laboratório de Investigação Fonoaudiológica nos Distúrbios do Espectro do Autismo (Research Laboratory on Language Disorders in the Autism Spectrum) of the School of Medicine, Universidade de São Paulo, where it is routinely applied during the annual assessment. Answers to the different areas of DAADD are similar to the different areas of ABC. These data show data the diagnosis by DAADD is easier in older children. Although there is no significant difference, the large occurrence of Rett's syndrome diagnosis according to the DAADD was associated to higher risk for autism according to the ABC in G1. With increasing age this tendency decreases and either in G2 and G3 Autism is the most frequent diagnosis. Although the results of both questionnaires tend to agree more with increasing age, the DAADD is more sensitive in the different ages while the ABC if more specific only to older children.

  10. [Comparative assessment of cryosurgical treatment results in allergic and non-allergic rhinitis].

    Science.gov (United States)

    Zielińska-Bliżniewska, Hanna; Repetowski, Marcin; Miłoński, Jarosław; Olszewski, Jurek

    2011-01-01

    The aim of the work was to assess the treatment efficiency in patients with allergic and non-allergic vasomotor rhinitis after cryoablation procedures. The study covered 60 patients, including 32 women and 28 men, aged 18-66. The patients were divided into two groups: I - 30 patients with chronic allergic rhinitis, II - 30 patients with non-allergic vasomotor rhinitis. The study methodology involved: an otorhinolaryngological interview with a questionnaire and an allergological interview, an objective otolaryngological and rhinomanometrical examination with Homoth apparatus, a subjective evaluation questionnaire for nasal blockage intensification (the scale ranging from 0 to 10), skin tests to aeorallergens and food allergens (Allergopharma Co.), nasal endoscopy with a straight rigid Eleps endoscope before the treatment and 3 months following it. The cryoablation of nasal conchas was performed under local infiltration anesthesia (1% Xylokaina solution) using the Cryo-S apparatus from CryoFlex Poland Company and a flat probe in a spatula shape (L-50) that was placed on the outer surfaces of the inferior nasal concha. The inferior nasal concha cryoablation resulted in a statistically significant improvement in the subjective assessment scale in group I by 82.6% and group II by 141.2%. In the endoscopic examination 3 months following the cryoablation a good nasal patency was achieved in 63.3% patients from group I and 76.7% patients from group II. The conducted studies show a better nasal passages patency in patients with non-allergic rhinitis than in those with allergic rhinitis. Cryoablation procedures on the inferior nasal conchas are not the primary therapy, but together with other methods they can immensely improve the life comfort of a rhinitis patient. Copyright © 2011 Polish Otolaryngology Society. Published by Elsevier Urban & Partner (Poland). All rights reserved.

  11. COMPARATIVE STUDY ON METHODS FOR 3D MODELLING OF URBAN AREAS

    Directory of Open Access Journals (Sweden)

    E. Oniga

    2012-07-01

    Full Text Available This article presents (comparatively the methodology for creating a 3D model of the urban area, based on terrestrial laser scanner, traditional technologies of terrestrial photogrammetry and aerial images. We are reviewing the data sources, their preliminary processing to be brought in a common system and the software used for this purpose. The case study presents the comparative results obtained using the methods listed above. To obtain the 3D models with terrestrial laser scanner systems have been used the dates achieved with ScanStation 2. To obtain the 3D model drawn by traditional photogrammetric methods using the UMK terrestrial camera, have been used auxiliary dates from topographic measurements with GPS systems and total stations as well as the current topographic plans. For the 3D model creation based on the dates taken with aerial digital cameras, were used the aerial images, taken with the ADS40 photogrammetric aerial camera. The comparative study between the three methods was accomplished by analyzing the object space representation fidelity, the precision of the 3D models obtained by comparison of the distances, areas and volumes, comparing the execution time and execution costs. The article presents the conclusions, the advantages and disadvantages of the three technologies based on the criteria listed above.

  12. Final model independent result of DAMA/LIBRA-phase1

    Energy Technology Data Exchange (ETDEWEB)

    Bernabei, R.; D' Angelo, S.; Di Marco, A. [Universita di Roma ' ' Tor Vergata' ' , Dipartimento di Fisica, Rome (Italy); INFN, sez. Roma ' ' Tor Vergata' ' , Rome (Italy); Belli, P. [INFN, sez. Roma ' ' Tor Vergata' ' , Rome (Italy); Cappella, F.; D' Angelo, A.; Prosperi, D. [Universita di Roma ' ' La Sapienza' ' , Dipartimento di Fisica, Rome (Italy); INFN, sez. Roma, Rome (Italy); Caracciolo, V.; Castellano, S.; Cerulli, R. [INFN, Laboratori Nazionali del Gran Sasso, Assergi (Italy); Dai, C.J.; He, H.L.; Kuang, H.H.; Ma, X.H.; Sheng, X.D.; Wang, R.G. [Chinese Academy, IHEP, Beijing (China); Incicchitti, A. [INFN, sez. Roma, Rome (Italy); Montecchia, F. [INFN, sez. Roma ' ' Tor Vergata' ' , Rome (Italy); Universita di Roma ' ' Tor Vergata' ' , Dipartimento di Ingegneria Civile e Ingegneria Informatica, Rome (Italy); Ye, Z.P. [Chinese Academy, IHEP, Beijing (China); University of Jing Gangshan, Jiangxi (China)

    2013-12-15

    The results obtained with the total exposure of 1.04 ton x yr collected by DAMA/LIBRA-phase1 deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. during 7 annual cycles (i.e. adding a further 0.17 ton x yr exposure) are presented. The DAMA/LIBRA-phase1 data give evidence for the presence of Dark Matter (DM) particles in the galactic halo, on the basis of the exploited model independent DM annual modulation signature by using highly radio-pure NaI(Tl) target, at 7.5{sigma} C.L. Including also the first generation DAMA/NaI experiment (cumulative exposure 1.33 ton x yr, corresponding to 14 annual cycles), the C.L. is 9.3{sigma} and the modulation amplitude of the single-hit events in the (2-6) keV energy interval is: (0.0112{+-}0.0012) cpd/kg/keV; the measured phase is (144{+-}7) days and the measured period is (0.998{+-}0.002) yr, values well in agreement with those expected for DM particles. No systematic or side reaction able to mimic the exploited DM signature has been found or suggested by anyone over more than a decade. (orig.)

  13. Innovation ecosystem model for commercialization of research results

    Directory of Open Access Journals (Sweden)

    Vlăduţ Gabriel

    2017-07-01

    Full Text Available Innovation means Creativity and Added value recognise by the market. The first step in creating a sustainable commercialization of research results, Technological Transfer – TT mechanism, on one hand is to define the “technology” which will be transferred and on other hand to define the context in which the TT mechanism work, the ecosystem. The focus must be set on technology as an entity, not as a science or a study of the practical industrial arts and certainly not any specific applied science. The transfer object, the technology, must rely on a subjectively determined but specifiable set of processes and products. Focusing on the product is not sufficient to the transfer and diffusion of technology. It is not merely the product that is transferred but also knowledge of its use and application. The innovation ecosystem model brings together new companies, experienced business leaders, researchers, government officials, established technology companies, and investors. This environment provides those new companies with a wealth of technical expertise, business experience, and access to capital that supports innovation in the early stages of growth.

  14. Blade element momentum modeling of inflow with shear in comparison with advanced model results

    DEFF Research Database (Denmark)

    Aagaard Madsen, Helge; Riziotis, V.; Zahle, Frederik

    2012-01-01

    shear is present in the inflow. This gives guidance to how the BEM modeling of shear should be implemented. Another result from the advanced vortex model computations is a clear indication of influence of the ground, and the general tendency is a speed up effect of the flow through the rotor giving...

  15. Comparative study of various models of experimental hydrocephalus.

    Science.gov (United States)

    Matsumoto, S; Hirayama, A; Yamasaki, S; Shirataki, K; Fujiwara, K

    1975-01-01

    The authors present morphological findings in the brains of rabbits, dogs, cats, rats, and mice that have been used as experimental hydrocephalic models. The methods used were as follows: (1) silicone oil injection into the cisterna magna and the neighboring basal cisterns in rabbits by the method of Wisniewski; (2) kaolin administration into the cisterna magna in rabbits and dogs (Dixon); (3) ballooning method with Foley's catheter into the 4th ventricle in rabbits (Milho-rat); (4) plug formation with small pieces of laminalia into the cisterna magna in rabbits by our method; (5) Hy-3 hereditary hydrocephalic mouse bred by Gruenberg; (6) ligation of the placental vessels of the pregnant rat at 13 days of gestation by our method, and (7) transplacental intraperitoneal administration of ethylnitrosourea in a pregnant rat at 9.5 days of gestation. The models with silicone oil, kaolin, laminalia, and ballooning methods produced obstructive hydrocephalus with various grades of ventricular dilatation. The models with the ethylnitrosourea-induced method, ligation of placental vessels, and Hy-3 mouse produced prenatal hydrocephalus. Dilatation of the ventricular system and histological abnormalities do not occur as a uniform process.

  16. Regionalization of climate model results for the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Kauker, F.

    1999-07-01

    A dynamical downscaling is presented that allows an estimation of potential effects of climate change on the North Sea. Therefore, the ocean general circulation model OPYC is adapted for application on a shelf by adding a lateral boundary formulation and a tide model. In this set-up the model is forced, first, with data from the ECMWF reanalysis for model validation and the study of the natural variability, and, second, with data from climate change experiments to estimate the effects of climate change on the North Sea. (orig.)

  17. A Comparative Data-Based Modeling Study on Respiratory CO2 Gas Exchange during Mechanical Ventilation

    Directory of Open Access Journals (Sweden)

    Chang-Sei eKim

    2016-02-01

    Full Text Available The goal of this study is to derive a minimally complex but credible model of respiratory CO2 gas exchange that may be used in systematic design and pilot testing of closed-loop end-tidal CO2 controllers in mechanical ventilation. We first derived a candidate model that captures the essential mechanisms involved in the respiratory CO2 gas exchange process. Then, we simplified the candidate model to derive two lower-order candidate models. We compared these candidate models for predictive capability and reliability using experimental data collected from 25 pediatric subjects undergoing dynamically varying mechanical ventilation during surgical procedures. A two-compartment model equipped with transport delay to account for CO2 delivery between the lungs and the tissues showed modest but statistically significant improvement in predictive capability over the same model without transport delay. Aggregating the lungs and the tissues into a single compartment further degraded the predictive fidelity of the model. In addition, the model equipped with transport delay demonstrated superior reliability to the one without transport delay. Further, the respiratory parameters derived from the model equipped with transport delay, but not the one without transport delay, were physiologically plausible. The results suggest that gas transport between the lungs and the tissues must be taken into account to accurately reproduce the respiratory CO2 gas exchange process under conditions of wide-ranging and dynamically varying mechanical ventilation conditions.

  18. A Multi-model Study on Warm Precipitation Biases in Global Models Compared to Satellite Observations

    Science.gov (United States)

    Jing, X.; Suzuki, K.; Guo, H.; Goto, D.; Ogura, T.; Koshiro, T.; Mulmenstadt, J.

    2017-12-01

    The cloud-to-precipitation transition process in warm clouds simulated by state-of-the-art global climate models (GCMs), including both traditional climate models and a global cloud-resolving model, is evaluated against A-Train satellites observations. The models and satellite observations are compared in the form of the statistics obtained from combined analysis of multiple satellite observables that probe signatures of the cloud-to-precipitation transition process. One common problem identified among these models is the too frequent occurrence of warm precipitation. The precipitation is found to form when the cloud particle size and the liquid water path (LWP) are both much smaller than those in observations. The too efficient formation of precipitation is found to be compensated for by errors of cloud microphysical properties, such as underestimated cloud particle size and LWP, to an extent that varies among the models. However, this does not completely cancel the precipitation formation bias. Robust errors are also found in the evolution of cloud microphysical properties in precipitation process in some GCMs, implying unrealistic interaction between precipitation and cloud water. Nevertheless, auspicious information is found for future improvement of warm precipitation representations: the adoption of more realistic autoconversion scheme or subgrid variability scheme is shown to improve the triggering of precipitation and evolution of cloud microphysical properties.

  19. Clinical Prediction Models for Cardiovascular Disease: Tufts Predictive Analytics and Comparative Effectiveness Clinical Prediction Model Database.

    Science.gov (United States)

    Wessler, Benjamin S; Lai Yh, Lana; Kramer, Whitney; Cangelosi, Michael; Raman, Gowri; Lutz, Jennifer S; Kent, David M

    2015-07-01

    Clinical prediction models (CPMs) estimate the probability of clinical outcomes and hold the potential to improve decision making and individualize care. For patients with cardiovascular disease, there are numerous CPMs available although the extent of this literature is not well described. We conducted a systematic review for articles containing CPMs for cardiovascular disease published between January 1990 and May 2012. Cardiovascular disease includes coronary heart disease, heart failure, arrhythmias, stroke, venous thromboembolism, and peripheral vascular disease. We created a novel database and characterized CPMs based on the stage of development, population under study, performance, covariates, and predicted outcomes. There are 796 models included in this database. The number of CPMs published each year is increasing steadily over time. Seven hundred seventeen (90%) are de novo CPMs, 21 (3%) are CPM recalibrations, and 58 (7%) are CPM adaptations. This database contains CPMs for 31 index conditions, including 215 CPMs for patients with coronary artery disease, 168 CPMs for population samples, and 79 models for patients with heart failure. There are 77 distinct index/outcome pairings. Of the de novo models in this database, 450 (63%) report a c-statistic and 259 (36%) report some information on calibration. There is an abundance of CPMs available for a wide assortment of cardiovascular disease conditions, with substantial redundancy in the literature. The comparative performance of these models, the consistency of effects and risk estimates across models and the actual and potential clinical impact of this body of literature is poorly understood. © 2015 American Heart Association, Inc.

  20. MSFC Stream Model Preliminary Results: Modeling Recent Leonid and Perseid Encounters

    Science.gov (United States)

    Cooke, William J.; Moser, Danielle E.

    2004-01-01

    The cometary meteoroid ejection model of Jones and Brown (1996b) was used to simulate ejection from comets 55P/Tempel-Tuttle during the last 12 revolutions, and the last 9 apparitions of 109P/Swift-Tuttle. Using cometary ephemerides generated by the Jet Propulsion Laboratory s (JPL) HORIZONS Solar System Data and Ephemeris Computation Service, two independent ejection schemes were simulated. In the first case, ejection was simulated in 1 hour time steps along the comet s orbit while it was within 2.5 AU of the Sun. In the second case, ejection was simulated to occur at the hour the comet reached perihelion. A 4th order variable step-size Runge-Kutta integrator was then used to integrate meteoroid position and velocity forward in time, accounting for the effects of radiation pressure, Poynting-Robertson drag, and the gravitational forces of the planets, which were computed using JPL s DE406 planetary ephemerides. An impact parameter was computed for each particle approaching the Earth to create a flux profile, and the results compared to observations of the 1998 and 1999 Leonid showers, and the 1993 and 2004 Perseids.

  1. Effect of geometry of rice kernels on drying modeling results

    Science.gov (United States)

    Geometry of rice grain is commonly represented by sphere, spheroid or ellipsoid shapes in the drying models. Models using simpler shapes are easy to solve mathematically, however, deviation from the true grain shape might lead to large errors in predictions of drying characteristics such as, moistur...

  2. Quark cluster model of nuclei and lepton scattering results

    International Nuclear Information System (INIS)

    Vary, J.P.; Iowa State Univ. of Science and Technology, Ames

    1984-01-01

    A review of the quark cluster model (QCM) of nuclei is presented along with applications to deep inelastic lepton scattering and elastic lepton scattering experiments. In addition a sample comparison is made with high momentum transfer (p, π) data. The QCM prediction for the ratio of nuclear structure functions in the x > 1 domain is discussed as a critical test of the model

  3. How to: understanding SWAT model uncertainty relative to measured results

    Science.gov (United States)

    Watershed models are being relied upon to contribute to most policy-making decisions of watershed management, and the demand for an accurate accounting of complete model uncertainty is rising. Generalized likelihood uncertainty estimation (GLUE) is a widely used method for quantifying uncertainty i...

  4. Comparing the MOLAP the ROLAP storage models Marysol

    Directory of Open Access Journals (Sweden)

    N Tamayo

    2006-09-01

    Full Text Available Data Warehouses (DWs, supported by OLAP, have played a key role in helping company decision-making du- ring the last few years. DWs can be stored in ROLAP and/or MOLAP data storage systems. Data is stored in a relational database in ROLAP and in multidimensional matrices in MOLAP. This paper presents a comparative example, analysing the performance and advantages and disadvantages of ROLAP and MOLAP in a specific database management system (DBMS. An overview of DBMS is also given to see how these technologies are being incorporated.

  5. Comparative assay of fluorescent antibody test results among twelve European National Reference Laboratories using various anti-rabies conjugates

    DEFF Research Database (Denmark)

    Robardet, E.; Andrieu, S.; Rasmussen, Thomas Bruun

    2013-01-01

    Twelve National Reference Laboratories (NRLs) for rabies have undertaken a comparative assay to assess the comparison of fluorescent antibody test (FAT) results using five coded commercial anti-rabies conjugates (Biorad, Bioveta, Fujirebio, Millipore, and SIFIN conjugates). Homogenized positive...

  6. results

    Directory of Open Access Journals (Sweden)

    Salabura Piotr

    2017-01-01

    Full Text Available HADES experiment at GSI is the only high precision experiment probing nuclear matter in the beam energy range of a few AGeV. Pion, proton and ion beams are used to study rare dielectron and strangeness probes to diagnose properties of strongly interacting matter in this energy regime. Selected results from p + A and A + A collisions are presented and discussed.

  7. Comparing artificial neural networks, general linear models and support vector machines in building predictive models for small interfering RNAs.

    Directory of Open Access Journals (Sweden)

    Kyle A McQuisten

    2009-10-01

    Full Text Available Exogenous short interfering RNAs (siRNAs induce a gene knockdown effect in cells by interacting with naturally occurring RNA processing machinery. However not all siRNAs induce this effect equally. Several heterogeneous kinds of machine learning techniques and feature sets have been applied to modeling siRNAs and their abilities to induce knockdown. There is some growing agreement to which techniques produce maximally predictive models and yet there is little consensus for methods to compare among predictive models. Also, there are few comparative studies that address what the effect of choosing learning technique, feature set or cross validation approach has on finding and discriminating among predictive models.Three learning techniques were used to develop predictive models for effective siRNA sequences including Artificial Neural Networks (ANNs, General Linear Models (GLMs and Support Vector Machines (SVMs. Five feature mapping methods were also used to generate models of siRNA activities. The 2 factors of learning technique and feature mapping were evaluated by complete 3x5 factorial ANOVA. Overall, both learning techniques and feature mapping contributed significantly to the observed variance in predictive models, but to differing degrees for precision and accuracy as well as across different kinds and levels of model cross-validation.The methods presented here provide a robust statistical framework to compare among models developed under distinct learning techniques and feature sets for siRNAs. Further comparisons among current or future modeling approaches should apply these or other suitable statistically equivalent methods to critically evaluate the performance of proposed models. ANN and GLM techniques tend to be more sensitive to the inclusion of noisy features, but the SVM technique is more robust under large numbers of features for measures of model precision and accuracy. Features found to result in maximally predictive models are

  8. A simplified MHD model of capillary Z-Pinch compared with experiments

    Energy Technology Data Exchange (ETDEWEB)

    Shapolov, A.A.; Kiss, M.; Kukhlevsky, S.V. [Institute of Physics, University of Pecs (Hungary)

    2016-11-15

    The most accurate models of the capillary Z-pinches used for excitation of soft X-ray lasers and photolithography XUV sources currently are based on the magnetohydrodynamics theory (MHD). The output of MHD-based models greatly depends on details in the mathematical description, such as initial and boundary conditions, approximations of plasma parameters, etc. Small experimental groups who develop soft X-ray/XUV sources often use the simplest Z-pinch models for analysis of their experimental results, despite of these models are inconsistent with the MHD equations. In the present study, keeping only the essential terms in the MHD equations, we obtained a simplified MHD model of cylindrically symmetric capillary Z-pinch. The model gives accurate results compared to experiments with argon plasmas, and provides simple analysis of temporal evolution of main plasma parameters. The results clarify the influence of viscosity, heat flux and approximations of plasma conductivity on the dynamics of capillary Z-pinch plasmas. The model can be useful for researchers, especially experimentalists, who develop the soft X-ray/XUV sources. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Comparative analysis of calculation models of railway subgrade

    Directory of Open Access Journals (Sweden)

    I.O. Sviatko

    2013-08-01

    Full Text Available Purpose. In transport engineering structures design, the primary task is to determine the parameters of foundation soil and nuances of its work under loads. It is very important to determine the parameters of shear resistance and the parameters, determining the development of deep deformations in foundation soils, while calculating the soil subgrade - upper track structure interaction. Search for generalized numerical modeling methods of embankment foundation soil work that include not only the analysis of the foundation stress state but also of its deformed one. Methodology. The analysis of existing modern and classical methods of numerical simulation of soil samples under static load was made. Findings. According to traditional methods of analysis of ground masses work, limitation and the qualitative estimation of subgrade deformations is possible only indirectly, through the estimation of stress and comparison of received values with the boundary ones. Originality. A new computational model was proposed in which it will be applied not only classical approach analysis of the soil subgrade stress state, but deformed state will be also taken into account. Practical value. The analysis showed that for accurate analysis of ground masses work it is necessary to develop a generalized methodology for analyzing of the rolling stock - railway subgrade interaction, which will use not only the classical approach of analyzing the soil subgrade stress state, but also take into account its deformed one.

  10. Modeling the radiation transfer of discontinuous canopies: results for gap probability and single-scattering contribution

    Science.gov (United States)

    Zhao, Feng; Zou, Kai; Shang, Hong; Ji, Zheng; Zhao, Huijie; Huang, Wenjiang; Li, Cunjun

    2010-10-01

    In this paper we present an analytical model for the computation of radiation transfer of discontinuous vegetation canopies. Some initial results of gap probability and bidirectional gap probability of discontinuous vegetation canopies, which are important parameters determining the radiative environment of the canopies, are given and compared with a 3- D computer simulation model. In the model, negative exponential attenuation of light within individual plant canopies is assumed. Then the computation of gap probability is resolved by determining the entry points and exiting points of the ray with the individual plants via their equations in space. For the bidirectional gap probability, which determines the single-scattering contribution of the canopy, a gap statistical analysis based model was adopted to correct the dependence of gap probabilities for both solar and viewing directions. The model incorporates the structural characteristics, such as plant sizes, leaf size, row spacing, foliage density, planting density, leaf inclination distribution. Available experimental data are inadequate for a complete validation of the model. So it was evaluated with a three dimensional computer simulation model for 3D vegetative scenes, which shows good agreement between these two models' results. This model should be useful to the quantification of light interception and the modeling of bidirectional reflectance distributions of discontinuous canopies.

  11. Comparative study of cost models for tokamak DEMO fusion reactors

    International Nuclear Information System (INIS)

    Oishi, Tetsutarou; Yamazaki, Kozo; Arimoto, Hideki; Ban, Kanae; Kondo, Takuya; Tobita, Kenji; Goto, Takuya

    2012-01-01

    Cost evaluation analysis of the tokamak-type demonstration reactor DEMO using the PEC (physics-engineering-cost) system code is underway to establish a cost evaluation model for the DEMO reactor design. As a reference case, a DEMO reactor with reference to the SSTR (steady state tokamak reactor) was designed using PEC code. The calculated total capital cost was in the same order of that proposed previously in cost evaluation studies for the SSTR. Design parameter scanning analysis and multi regression analysis illustrated the effect of parameters on the total capital cost. The capital cost was predicted to be inside the range of several thousands of M$s in this study. (author)

  12. Comparing different CFD wind turbine modelling approaches with wind tunnel measurements

    Science.gov (United States)

    Kalvig, Siri; Manger, Eirik; Hjertager, Bjørn

    2014-12-01

    The performance of a model wind turbine is simulated with three different CFD methods: actuator disk, actuator line and a fully resolved rotor. The simulations are compared with each other and with measurements from a wind tunnel experiment. The actuator disk is the least accurate and most cost-efficient, and the fully resolved rotor is the most accurate and least cost-efficient. The actuator line method is believed to lie in between the two ends of the scale. The fully resolved rotor produces superior wake velocity results compared to the actuator models. On average it also produces better results for the force predictions, although the actuator line method had a slightly better match for the design tip speed. The open source CFD tool box, OpenFOAM, was used for the actuator disk and actuator line calculations, whereas the market leading commercial CFD code, ANSYS/FLUENT, was used for the fully resolved rotor approach.

  13. Sustainable recycling model : A comparative analysis between India and Tanzania

    NARCIS (Netherlands)

    Uiterkamp, Bob Jan Schoot; Azadi, Hossein; Ho, Peter

    Higher economic growth in developing countries has caused higher amounts of wastes. Local government authorities in these countries usually fail to provide adequate services to dispose the increasing amounts of waste, resulting in threats for both the population and environment health. There is

  14. Comparative analysis of Vening-Meinesz Moritz isostatic models ...

    Indian Academy of Sciences (India)

    ... the combined least-squares approach for a simultaneous estimation of both Moho parameters. We demonstrate that the result obtained using this method has the best agreement with the CRUST2.0 Moho depths. The numerical experiments are conducted at the regional study area of New Zealand's continental shelf.

  15. New analytic results for speciation times in neutral models.

    Science.gov (United States)

    Gernhard, Tanja

    2008-05-01

    In this paper, we investigate the standard Yule model, and a recently studied model of speciation and extinction, the "critical branching process." We develop an analytic way-as opposed to the common simulation approach-for calculating the speciation times in a reconstructed phylogenetic tree. Simple expressions for the density and the moments of the speciation times are obtained. Methods for dating a speciation event become valuable, if for the reconstructed phylogenetic trees, no time scale is available. A missing time scale could be due to supertree methods, morphological data, or molecular data which violates the molecular clock. Our analytic approach is, in particular, useful for the model with extinction, since simulations of birth-death processes which are conditioned on obtaining n extant species today are quite delicate. Further, simulations are very time consuming for big n under both models.

  16. Box photosynthesis modeling results for WRF/CMAQ LSM

    Data.gov (United States)

    U.S. Environmental Protection Agency — Box Photosynthesis model simulations for latent heat and ozone at 6 different FLUXNET sites. This dataset is associated with the following publication: Ran, L., J....

  17. Results of comparative RBMK neutron computation using VNIIEF codes (cell computation, 3D statics, 3D kinetics). Final report

    Energy Technology Data Exchange (ETDEWEB)

    Grebennikov, A.N.; Zhitnik, A.K.; Zvenigorodskaya, O.A. [and others

    1995-12-31

    In conformity with the protocol of the Workshop under Contract {open_quotes}Assessment of RBMK reactor safety using modern Western Codes{close_quotes} VNIIEF performed a neutronics computation series to compare western and VNIIEF codes and assess whether VNIIEF codes are suitable for RBMK type reactor safety assessment computation. The work was carried out in close collaboration with M.I. Rozhdestvensky and L.M. Podlazov, NIKIET employees. The effort involved: (1) cell computations with the WIMS, EKRAN codes (improved modification of the LOMA code) and the S-90 code (VNIIEF Monte Carlo). Cell, polycell, burnup computation; (2) 3D computation of static states with the KORAT-3D and NEU codes and comparison with results of computation with the NESTLE code (USA). The computations were performed in the geometry and using the neutron constants presented by the American party; (3) 3D computation of neutron kinetics with the KORAT-3D and NEU codes. These computations were performed in two formulations, both being developed in collaboration with NIKIET. Formulation of the first problem maximally possibly agrees with one of NESTLE problems and imitates gas bubble travel through a core. The second problem is a model of the RBMK as a whole with imitation of control and protection system controls (CPS) movement in a core.

  18. Results of comparative RBMK neutron computation using VNIIEF codes (cell computation, 3D statics, 3D kinetics). Final report

    International Nuclear Information System (INIS)

    Grebennikov, A.N.; Zhitnik, A.K.; Zvenigorodskaya, O.A.

    1995-01-01

    In conformity with the protocol of the Workshop under Contract open-quotes Assessment of RBMK reactor safety using modern Western Codesclose quotes VNIIEF performed a neutronics computation series to compare western and VNIIEF codes and assess whether VNIIEF codes are suitable for RBMK type reactor safety assessment computation. The work was carried out in close collaboration with M.I. Rozhdestvensky and L.M. Podlazov, NIKIET employees. The effort involved: (1) cell computations with the WIMS, EKRAN codes (improved modification of the LOMA code) and the S-90 code (VNIIEF Monte Carlo). Cell, polycell, burnup computation; (2) 3D computation of static states with the KORAT-3D and NEU codes and comparison with results of computation with the NESTLE code (USA). The computations were performed in the geometry and using the neutron constants presented by the American party; (3) 3D computation of neutron kinetics with the KORAT-3D and NEU codes. These computations were performed in two formulations, both being developed in collaboration with NIKIET. Formulation of the first problem maximally possibly agrees with one of NESTLE problems and imitates gas bubble travel through a core. The second problem is a model of the RBMK as a whole with imitation of control and protection system controls (CPS) movement in a core

  19. New Results in Optical Modelling of Quantum Well Solar Cells

    Directory of Open Access Journals (Sweden)

    Silvian Fara

    2012-01-01

    Full Text Available This project brought further advancements to the quantum well solar cell concept proposed by Keith Barnham. In this paper, the optical modelling of MQW solar cells was analyzed and we focussed on the following topics: (i simulation of the refraction index and the reflectance, (ii simulation of the absorption coefficient, (iii simulation of the quantum efficiency for the absorption process, (iv discussion and modelling of the quantum confinement effect, and (v evaluation of datasheet parameters of the MQW cell.

  20. Some Econometric Results for the Blanchard-Watson Bubble Model

    DEFF Research Database (Denmark)

    Johansen, Soren; Lange, Theis

    The purpose of the present paper is to analyse a simple bubble model suggested by Blanchard and Watson. The model is defined by y(t) =s(t)¿y(t-1)+e(t), t=1,…,n, where s(t) is an i.i.d. binary variable with p=P(s(t)=1), independent of e(t) i.i.d. with mean zero and finite variance. We take ¿>1 so ...

  1. Comparative Analysis of Soft Computing Models in Prediction of Bending Rigidity of Cotton Woven Fabrics

    Science.gov (United States)

    Guruprasad, R.; Behera, B. K.

    2015-10-01

    Quantitative prediction of fabric mechanical properties is an essential requirement for design engineering of textile and apparel products. In this work, the possibility of prediction of bending rigidity of cotton woven fabrics has been explored with the application of Artificial Neural Network (ANN) and two hybrid methodologies, namely Neuro-genetic modeling and Adaptive Neuro-Fuzzy Inference System (ANFIS) modeling. For this purpose, a set of cotton woven grey fabrics was desized, scoured and relaxed. The fabrics were then conditioned and tested for bending properties. With the database thus created, a neural network model was first developed using back propagation as the learning algorithm. The second model was developed by applying a hybrid learning strategy, in which genetic algorithm was first used as a learning algorithm to optimize the number of neurons and connection weights of the neural network. The Genetic algorithm optimized network structure was further allowed to learn using back propagation algorithm. In the third model, an ANFIS modeling approach was attempted to map the input-output data. The prediction performances of the models were compared and a sensitivity analysis was reported. The results show that the prediction by neuro-genetic and ANFIS models were better in comparison with that of back propagation neural network model.

  2. Comparative Analysis of Market Volatility in Indian Banking and IT Sectors by using Average Decline Model

    OpenAIRE

    Kirti AREKAR; Rinku JAIN

    2017-01-01

    The stock market volatility is depends on three major features, complete volatility, volatility fluctuations, and volatility attention and they are calculate by the statistical techniques. Comparative analysis of market volatility for two major index i.e. banking & IT sector in Bombay stock exchange (BSE) by using average decline model. The average degeneration process in volatility has being used after very high and low stock returns. The results of this study explain significant decline in...

  3. Lattice Hamiltonian approach to the Schwinger model. Further results from the strong coupling expansion

    International Nuclear Information System (INIS)

    Szyniszewski, Marcin; Manchester Univ.; Cichy, Krzysztof; Poznan Univ.; Kujawa-Cichy, Agnieszka

    2014-10-01

    We employ exact diagonalization with strong coupling expansion to the massless and massive Schwinger model. New results are presented for the ground state energy and scalar mass gap in the massless model, which improve the precision to nearly 10 -9 %. We also investigate the chiral condensate and compare our calculations to previous results available in the literature. Oscillations of the chiral condensate which are present while increasing the expansion order are also studied and are shown to be directly linked to the presence of flux loops in the system.

  4. Comparing CISNET Breast Cancer Incidence and Mortality Predictions to Observed Clinical Trial Results of Mammography Screening from Ages 40 to 49.

    Science.gov (United States)

    van den Broek, Jeroen J; van Ravesteyn, Nicolien T; Mandelblatt, Jeanne S; Huang, Hui; Ergun, Mehmet Ali; Burnside, Elizabeth S; Xu, Cong; Li, Yisheng; Alagoz, Oguzhan; Lee, Sandra J; Stout, Natasha K; Song, Juhee; Trentham-Dietz, Amy; Plevritis, Sylvia K; Moss, Sue M; de Koning, Harry J

    2018-04-01

    The UK Age trial compared annual mammography screening of women ages 40 to 49 years with no screening and found a statistically significant breast cancer mortality reduction at the 10-year follow-up but not at the 17-year follow-up. The objective of this study was to compare the observed Age trial results with the Cancer Intervention and Surveillance Modeling Network (CISNET) breast cancer model predicted results. Five established CISNET breast cancer models used data on population demographics, screening attendance, and mammography performance from the Age trial together with extant natural history parameters to project breast cancer incidence and mortality in the control and intervention arm of the trial. The models closely reproduced the effect of annual screening from ages 40 to 49 years on breast cancer incidence. Restricted to breast cancer deaths originating from cancers diagnosed during the intervention phase, the models estimated an average 15% (range across models, 13% to 17%) breast cancer mortality reduction at the 10-year follow-up compared with 25% (95% CI, 3% to 42%) observed in the trial. At the 17-year follow-up, the models predicted 13% (range, 10% to 17%) reduction in breast cancer mortality compared with the non-significant 12% (95% CI, -4% to 26%) in the trial. The models underestimated the effect of screening on breast cancer mortality at the 10-year follow-up. Overall, the models captured the observed long-term effect of screening from age 40 to 49 years on breast cancer incidence and mortality in the UK Age trial, suggesting that the model structures, input parameters, and assumptions about breast cancer natural history are reasonable for estimating the impact of screening on mortality in this age group.

  5. Comparing Three-Dimensional Geophysical Models of Mount St. Helens

    Science.gov (United States)

    Creager, K. C.; Ulberg, C. W.; Vidale, J. E.; Levander, A.; Kiser, E.; Abers, G. A.; Crosbie, K.; Mann, M. E.; Moran, S. C.; Denlinger, R. P.; Thelen, W. A.; Hansen, S. M.; Schmandt, B.; Schultz, A.; Bowles-martinez, E.; Bedrosian, P.; Peacock, J.; Hill, G.

    2017-12-01

    The iMUSH project integrates active- and passive-source seismic experiments with magnetotelluric (MT) observations and petrology to better understand the structure and dynamics of the Mount St. Helens (MSH) magmatic system from the subducted plate to the surface. The geophysical experiments included a two-year, 70-element broadband array with 10-km station spacing within 50 km of the MSH edifice, 23 shots recorded by geophones at 6000 sites including 900 Nodal stations, and 147 wideband MT stations with 6-km nominal station spacing. We have determined 3-D models of P-wave, S-wave and P/S-wave velocity as well as 3-D electrical resistivity. Our models from independent data sets and methodologies exhibit remarkable similarity. A narrow low-VP and VS anomaly as well as a high VP/VS and conductivity anomaly is well imaged by nearly all methods at about 6-15 km beneath MSH and coincides with a previously inferred magma storage volume. The St. Helens seismic zone (SHZ), which cuts through MSH with a NNW-SSE orientation, coincides with a narrow, vertical, planar zone of high electrical conductivity and low VP from the near surface to 15 km depth where we lose resolution. The continental Moho shows strong reflectivity east of the SHZ, but is weak to non-existent to the west, perhaps because this marks the eastern edge of hydrous mineral stability in the cold mantle wedge. Farther north, a similar high-conductivity feature is imaged along the west Rainer seismic zone. High Vp/Vs and high electrical conductivity extend under the Indian Heaven volcanic field at depths of 5-15 km, potentially associated with regions of partial melt and/or fluids. Mid- to lower-crustal velocities are generally fast to the west of MSH, consistent with the presence of the accreted Siletz terrane, and slow to the east suggesting both a change in composition and higher temperatures. Moderate lower-crustal resistivity is also present to the east, and is consistent with a small degree of partial melt

  6. A Comparative Analysis of Community Wind Power DevelopmentModels

    Energy Technology Data Exchange (ETDEWEB)

    Bolinger, Mark; Wiser, Ryan; Wind, Tom; Juhl, Dan; Grace, Robert; West, Peter

    2005-05-20

    For years, farmers in the United States have looked with envy on their European counterparts ability to profitably farm the wind through ownership of distributed, utility-scale wind projects. Only within the past few years, however, has farmer- or community-owned windpower development become a reality in the United States. The primary hurdle to this type of development in the United States has been devising and implementing suitable business and legal structures that enable such projects to take advantage of tax-based federal incentives for windpower. This article discusses the limitations of such incentives in supporting farmer- or community-owned wind projects, describes four ownership structures that potentially overcome such limitations, and finally conducts comparative financial analysis on those four structures, using as an example a hypothetical 1.5 MW farmer-owned project located in the state of Oregon. We find that material differences in the competitiveness of each structure do exist, but that choosing the best structure for a given project will largely depend on the conditions at hand; e.g., the ability of the farmer(s) to utilize tax credits, preference for individual versus cooperative ownership, and the state and utility service territory in which the project will be located.

  7. Spheroid model study comparing the biocompatibility of Biodentine and MTA.

    Science.gov (United States)

    Pérard, Matthieu; Le Clerc, Justine; Watrin, Tanguy; Meary, Fleur; Pérez, Fabienne; Tricot-Doleux, Sylvie; Pellen-Mussi, Pascal

    2013-06-01

    The primary objective of this study was to assess the biological effects of a new dentine substitute based on Ca₃SiO₅ (Biodentine™) for use in pulp-capping treatment, on pseudo-odontoblastic (MDPC-23) and pulp (Od-21) cells. The secondary objective was to evaluate the effects of Biodentine and mineral trioxide aggregate (MTA) on gene expression in cultured spheroids. We used the acid phosphatase assay to compare the biocompatibility of Biodentine and MTA. Cell differentiation was investigated by RT-qPCR. We investigated the expression of genes involved in odontogenic differentiation (Runx2), matrix secretion (Col1a1, Spp1) and mineralisation (Alp). ANOVA and PLSD tests were used for data analysis. MDPC-23 cells cultured in the presence of MTA had higher levels of viability than those cultured in the presence of Biodentine and control cells on day 7 (P = 0.0065 and P = 0.0126, respectively). For Od-21 cells, proliferation rates on day 7 were significantly lower in the presence of Biodentine or MTA than for control (P Biodentine and in control cells. Biodentine and MTA may modify the proliferation of pulp cell lines. Their effects may fluctuate over time, depending on the cell line considered. The observed similarity between Biodentine and MTA validates the indication for direct pulp-capping claimed by the manufacturers.

  8. National Models of Technological Development: a Comparative Analysis

    Directory of Open Access Journals (Sweden)

    Evgeniy V. Balatskiy

    2017-12-01

    Full Text Available In the article, suggestions are made for the development of methodological approaches to using factor analysis of technological development of countries and revealing the related weaknesses. The article presents an overview of the ideas for the study of such categories as national innovation system, its elements – the scientific and technological sector and approaches to efficiency measurement and comparative analysis of national innovation systems of different countries. For the purposes of assessing the scientific and technological potential of countries, a method of constructing a scientific-technological balance which links the efficiency of the national economy to the sphere of generation of knowledge and technologies, is proposed. Analysis of the relative scientific and technological parameters showed that each country has its advantages and disadvantages for research and technological development. In particular, in China, the scale of research sector is not adequate to the scale of the national economy and its growth rate; Poland has been experiencing low returns from the sphere of applied research; in Russia the bottleneck for scientific and technological development is low efficiency of the scientific work expressed in the publication activity. Overall, the study showed that the scientific and technological balance constructing method is a successful one in assessing the impact of knowledge generation and technology development on the level of productivity in the economy.

  9. Water Management in the Camargue Biosphere Reserve: Insights from Comparative Mental Models Analysis

    Directory of Open Access Journals (Sweden)

    Raphael Mathevet

    2011-03-01

    Full Text Available Mental models are the cognitive representations of the world that frame how people interact with the world. Learning implies changing these mental models. The successful management of complex social-ecological systems requires the coordination of actions to achieve shared goals. The coordination of actions requires a level of shared understanding of the system or situation; a shared or common mental model. We first describe the elicitation and analysis of mental models of different stakeholder groups associated with water management in the Camargue Biosphere Reserve in the Rhône River delta on the French Mediterranean coast. We use cultural consensus analysis to explore the degree to which different groups shared mental models of the whole system, of stakeholders, of resources, of processes, and of interactions among these last three. The analysis of the elicited data from this group structure enabled us to tentatively explore the evidence for learning in the nonstatute Water Board; comprising important stakeholders related to the management of the central Rhône delta. The results indicate that learning does occur and results in richer mental models that are more likely to be shared among group members. However, the results also show lower than expected levels of agreement with these consensual mental models. Based on this result, we argue that a careful process and facilitation design can greatly enhance the functioning of the participatory process in the Water Board. We conclude that this methodology holds promise for eliciting and comparing mental models. It enriches group-model building and participatory approaches with a broader view of social learning and knowledge-sharing issues.

  10. Dihydrocodeine Overdoses in a Neonate and in a 14-year-old Girl Who Were Both Genotyped as Cytochrome P450 2D6*1/*10-*36: Comparing Developmental Ages and Drug Monitoring Data With the Results of Pharmacokinetic Modeling.

    Science.gov (United States)

    Shimizu, Makiko; Kondo, Tatsuki; Fukuoka, Tetsuya; Tanaka, Toshihiro; Yamazaki, Hiroshi

    2018-04-01

    A high activity of cytochrome P450 2D6 (CYP2D6) reportedly leads to toxicity of dihydrocodeine/codeine by increasing toxic potential of their metabolite dihydromorphine/morphine, which are further metabolized to highly active dihydromorphine 6-O-glucuronide and the less active morphine 3-O-glucorinide but rapidly excreted into urine as water-soluble forms. A case of acute respiratory depression after administration of prescribed dihydrocodeine phosphate (2.0 mg/d divided twice a day for 2 days) to a 1-month-old baby boy genotyped as CYP2D6*1/*10-*36 is described. The case is compared with that of a 14-year-old girl, also genotyped as CYP2D6*1/*10-*36, presenting in an agitated state after an overdose (37 mg) of dihydrocodeine phosphate taken as simultaneous ingestion of multiple over-the-counter tablets. In contrast to the rapid clearance of dihydrocodeine from blood in the 14-year-old girl (apparent half-life of 3 hours), the 1-month-old baby boy still had high serum concentrations of dihydrocodeine (400 nmol/L) and dihydromorphine (1.9 nmol/L) 21 hours after the last oral administration of dihydrocodeine-containing cough mixture. The rapid clearance in the 14-year-old girl was mainly attributed to dihydrocodeine glucuronidation and partly attributed to dihydromorphine formation, as determined by liquid chromatography-tandem mass spectrometry analyses. However, the conjugation ratios of dihydrocodeine and dihydromorphine in the neonate were low in comparison with those in the 14-year-old girl and with those measured in 3-, 6-, and 13-year-old control subjects, resulting from the poorly developed glucuronidation potential of the neonate. The current observations suggest that the CYP2D6*1/*10-*36 genotype seen in the 2 Japanese patients may not significantly contribute to the likelihood of dihydrocodeine overdose but highlight the importance of considering age when prescribing dihydrocodeine.

  11. Comparative analysis of the planar capacitor and IDT piezoelectric thin-film micro-actuator models

    International Nuclear Information System (INIS)

    Myers, Oliver J; Anjanappa, M; Freidhoff, Carl B

    2011-01-01

    A comparison of the analysis of similarly developed microactuators is presented. Accurate modeling and simulation techniques are vital for piezoelectrically actuated microactuators. Coupling analytical and numerical modeling techniques with variational design parameters, accurate performance predictions can be realized. Axi-symmetric two-dimensional and three-dimensional static deflection and harmonic models of a planar capacitor actuator are presented. Planar capacitor samples were modeled as unimorph diaphragms with sandwiched piezoelectric material. The harmonic frequencies were calculated numerically and compared well to predicted values and deformations. The finite element modeling reflects the impact of the d 31 piezoelectric constant. Two-dimensional axi-symmetric models of circularly interdigitated piezoelectrically membranes are also presented. The models include the piezoelectric material and properties, the membrane materials and properties, and incorporates various design considerations of the model. These models also include the electro-mechanical coupling for piezoelectric actuation and highlight a novel approach to take advantage of the higher d 33 piezoelectric coupling coefficient. Performance is evaluated for varying parameters such as electrode pitch, electrode width, and piezoelectric material thickness. The models also showed that several of the design parameters were naturally coupled. The static numerical models correlate well with the maximum static deflection of the experimental devices. Finally, this paper deals with the development of numerical harmonic models of piezoelectrically actuated planar capacitor and interdigitated diaphragms. The models were able to closely predict the first two harmonics, conservatively predict the third through sixth harmonics and predict the estimated values of center deflection using plate theory. Harmonic frequency and deflection simulations need further correlation by conducting extensive iterative

  12. Activity Modelling and Comparative Evaluation of WSN MAC Security Attacks

    DEFF Research Database (Denmark)

    Pawar, Pranav M.; Nielsen, Rasmus Hjorth; Prasad, Neeli R.

    2012-01-01

    Applications of wireless sensor networks (WSNs) are growing tremendously in the domains of habitat, tele-health, industry monitoring, vehicular networks, home automation and agriculture. This trend is a strong motivation for malicious users to increase their focus on WSNs and to develop and initi......Applications of wireless sensor networks (WSNs) are growing tremendously in the domains of habitat, tele-health, industry monitoring, vehicular networks, home automation and agriculture. This trend is a strong motivation for malicious users to increase their focus on WSNs and to develop...... and initiate security attacks that disturb the normal functioning of the network in a severe manner. Such attacks affect the performance of the network by increasing the energy consumption, by reducing throughput and by inducing long delays. Of all existing WSN attacks, MAC layer attacks are considered...... the most harmful as they directly affect the available resources and thus the nodes’ energy consumption. The first endeavour of this paper is to model the activities of MAC layer security attacks to understand the flow of activities taking place when mounting the attack and when actually executing it...

  13. Comparative study on the wake deflection behind yawed wind turbine models

    Science.gov (United States)

    Schottler, Jannik; Mühle, Franz; Bartl, Jan; Peinke, Joachim; Adaramola, Muyiwa S.; Sætran, Lars; Hölling, Michael

    2017-05-01

    In this wind tunnel campaign, detailed wake measurements behind two different model wind turbines in yawed conditions were performed. The wake deflections were quantified by estimating the rotor-averaged available power within the wake. By using two different model wind turbines, the influence of the rotor design and turbine geometry on the wake deflection caused by a yaw misalignment of 30° could be judged. It was found that the wake deflections three rotor diameters downstream were equal while at six rotor diameters downstream insignificant differences were observed. The results compare well with previous experimental and numerical studies.

  14. Cold Nuclear Matter effects on J/psi production at RHIC: comparing shadowing models

    Energy Technology Data Exchange (ETDEWEB)

    Ferreiro, E.G.; /Santiago de Compostela U.; Fleuret, F.; /Ecole Polytechnique; Lansberg, J.P.; /SLAC; Rakotozafindrabe, A.; /SPhN, DAPNIA, Saclay

    2009-06-19

    We present a wide study on the comparison of different shadowing models and their influence on J/{psi} production. We have taken into account the possibility of different partonic processes for the c{bar c}-pair production. We notice that the effect of shadowing corrections on J/{psi} production clearly depends on the partonic process considered. Our results are compared to the available data on dAu collisions at RHIC energies. We try different break up cross section for each of the studied shadowing models.

  15. A comparative analysis of 9 multi-model averaging approaches in hydrological continuous streamflow simulation

    Science.gov (United States)

    Arsenault, Richard; Gatien, Philippe; Renaud, Benoit; Brissette, François; Martel, Jean-Luc

    2015-10-01

    This study aims to test whether a weighted combination of several hydrological models can simulate flows more accurately than the models taken individually. In addition, the project attempts to identify the most efficient model averaging method and the optimal number of models to include in the weighting scheme. In order to address the first objective, streamflow was simulated using four lumped hydrological models (HSAMI, HMETS, MOHYSE and GR4J-6), each of which were calibrated with three different objective functions on 429 watersheds. The resulting 12 hydrographs (4 models × 3 metrics) were weighted and combined with the help of 9 averaging methods which are the simple arithmetic mean (SAM), Akaike information criterion (AICA), Bates-Granger (BGA), Bayes information criterion (BICA), Bayesian model averaging (BMA), Granger-Ramanathan average variant A, B and C (GRA, GRB and GRC) and the average by SCE-UA optimization (SCA). The same weights were then applied to the hydrographs in validation mode, and the Nash-Sutcliffe Efficiency metric was measured between the averaged and observed hydrographs. Statistical analyses were performed to compare the accuracy of weighted methods to that of individual models. A Kruskal-Wallis test and a multi-objective optimization algorithm were then used to identify the most efficient weighted method and the optimal number of models to integrate. Results suggest that the GRA, GRB, GRC and SCA weighted methods perform better than the individual members. Model averaging from these four methods were superior to the best of the individual members in 76% of the cases. Optimal combinations on all watersheds included at least one of each of the four hydrological models. None of the optimal combinations included all members of the ensemble of 12 hydrographs. The Granger-Ramanathan average variant C (GRC) is recommended as the best compromise between accuracy, speed of execution, and simplicity.

  16. Financial impact of errors in business forecasting: a comparative study of linear models and neural networks

    Directory of Open Access Journals (Sweden)

    Claudimar Pereira da Veiga

    2012-08-01

    Full Text Available The importance of demand forecasting as a management tool is a well documented issue. However, it is difficult to measure costs generated by forecasting errors and to find a model that assimilate the detailed operation of each company adequately. In general, when linear models fail in the forecasting process, more complex nonlinear models are considered. Although some studies comparing traditional models and neural networks have been conducted in the literature, the conclusions are usually contradictory. In this sense, the objective was to compare the accuracy of linear methods and neural networks with the current method used by the company. The results of this analysis also served as input to evaluate influence of errors in demand forecasting on the financial performance of the company. The study was based on historical data from five groups of food products, from 2004 to 2008. In general, one can affirm that all models tested presented good results (much better than the current forecasting method used, with mean absolute percent error (MAPE around 10%. The total financial impact for the company was 6,05% on annual sales.

  17. The Comparative Study of Collaborative Learning and SDLC Model to develop IT Group Projects

    Directory of Open Access Journals (Sweden)

    Sorapak Pukdesree

    2017-11-01

    Full Text Available The main objectives of this research were to compare the attitudes of learners between applying SDLC model with collaborative learning and typical SDLC model and to develop electronic courseware as group projects. The research was a quasi-experimental research. The populations of the research were students who took Computer Organization and Architecture course in the academic year 2015. There were 38 students who participated to the research. The participants were divided voluntary into two groups including an experimental group with 28 students using SDLC model with collaborative learning and a control group with 10 students using typical SDLC model. The research instruments were attitude questionnaire, semi-structured interview and self-assessment questionnaire. The collected data was analysed by arithmetic mean, standard deviation, and independent sample t-test. The results of the questionnaire revealed that the attitudes of the learners using collaborative learning and SDLC model were statistically significant difference between the mean score for experimental group and control group at a significance level of 0.05. The independent statistical analyses were significantly different between the two groups at a significance level of 0.05. The results of the interviewing revealed that most of the learners had the corresponding opinions that collaborative learning was very useful with highest level of their attitudes comparing with the previous methodology. Learners had left some feedbacks that collaborative learning should be applied to other courses.

  18. Metal accumulation in the earthworm Lumbricus rubellus. Model predictions compared to field data

    International Nuclear Information System (INIS)

    Veltman, Karin; Huijbregts, Mark A.J.; Vijver, Martina G.; Peijnenburg, Willie J.G.M.; Hobbelen, Peter H.F.; Koolhaas, Josee E.; Gestel, Cornelis A.M. van; Vliet, Petra C.J. van; Jan Hendriks, A.

    2007-01-01

    The mechanistic bioaccumulation model OMEGA (Optimal Modeling for Ecotoxicological Applications) is used to estimate accumulation of zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb) in the earthworm Lumbricus rubellus. Our validation to field accumulation data shows that the model accurately predicts internal cadmium concentrations. In addition, our results show that internal metal concentrations in the earthworm are less than linearly (slope < 1) related to the total concentration in soil, while risk assessment procedures often assume the biota-soil accumulation factor (BSAF) to be constant. Although predicted internal concentrations of all metals are generally within a factor 5 compared to field data, incorporation of regulation in the model is necessary to improve predictability of the essential metals such as zinc and copper. - Earthworm metal concentrations are less than linearly related to total soil concentrations and predicted pore water concentrations

  19. Results from Development of Model Specifications for Multifamily Energy Retrofits

    Energy Technology Data Exchange (ETDEWEB)

    Brozyna, K.

    2012-08-01

    Specifications, modeled after CSI MasterFormat, provide the trade contractors and builders with requirements and recommendations on specific building materials, components and industry practices that comply with the expectations and intent of the requirements within the various funding programs associated with a project. The goal is to create a greater level of consistency in execution of energy efficiency retrofits measures across the multiple regions a developer may work. IBACOS and Mercy Housing developed sample model specifications based on a common building construction type that Mercy Housing encounters.

  20. Results From Development of Model Specifications for Multifamily Energy Retrofits

    Energy Technology Data Exchange (ETDEWEB)

    Brozyna, Kevin [IBACOS, Inc., Pittsburgh, PA (United States)

    2012-08-01

    Specifications, modeled after CSI MasterFormat, provide the trade contractors and builders with requirements and recommendations on specific building materials, components and industry practices that comply with the expectations and intent of the requirements within the various funding programs associated with a project. The goal is to create a greater level of consistency in execution of energy efficiency retrofits measures across the multiple regions a developer may work. IBACOS and Mercy Housing developed sample model specifications based on a common building construction type that Mercy Housing encounters.

  1. Soil gas and radon entry into a simple test structure: Comparison of experimental and modelling results

    DEFF Research Database (Denmark)

    Andersen, C.E.; Søgaard-Hansen, J.; Majborn, B.

    1994-01-01

    A radon test structure has been established at a field site at Riso National Laboratory. Measurements have been made of soil gas entry rates, pressure couplings and radon depletion. The experimental results have been compared with results obtained from measured soil parameters and a two......-dimensional steady-state numerical model of Darcy flow and combined diffusive and advective transport of radon. For most probe locations, the calculated values of the pressure couplings and the radon depletion agree well with the measured values, thus verifying important elements of the Darcy flow approximation......, and the ability of the model to treat combined diffusive and advective transport of radon. However, the model gives an underestimation of the soil gas entry rate. Even if it is assumed that the soil has a permeability equal to the highest of the measured values, the model underestimates the soil gas entry rate...

  2. A Calibration of the Wierzbicki-Xue Damage Model Using Charpy Test Results

    Directory of Open Access Journals (Sweden)

    Kim Jong-Bong

    2015-01-01

    Full Text Available Damage models are frequently used to predict fractures in large deformation problems such as penetration of a projectile into a target. Though many damage models have been proposed so far, coefficients of each model have been provided for only a few materials. In this study, the coefficients of the Wierzbicki-Xue (2005 damage model for tungsten heavy alloy (DX2HCMF are determined using the Charpy impact test. The Wierzbicki-Xue fracture criterion is implemented into NET3D code in which a node-split algorithm is built in. By comparing the energy absorbed in the Charpy test with the results of finite element analysis, the fracture model coefficients are determined.

  3. Analysis of inelastic neutron scattering results on model compounds ...

    Indian Academy of Sciences (India)

    J Tomkinson heterobicyclic molecules could form a reasonable base of model compounds to un- derstand the eigenvectors of one interesting molecular system; the nitrogenous het- erocyclic bases of the nucleotides. Low energy molecular vibrational eigenvectors involve atomic displacements over the molecule as a whole ...

  4. Some Results On The Modelling Of TSS Manufacturing Lines

    Directory of Open Access Journals (Sweden)

    Viorel MÎNZU

    2000-12-01

    Full Text Available This paper deals with the modelling of a particular class of manufacturing lines, governed by a decentralised control strategy so that they balance themselves. Such lines are known as “bucket brigades” and also as “TSS lines”, after their first implementation, at Toyota, in the 70’s. A first study of their behaviour was based upon modelling as stochastic dynamic systems, which emphasised, in the frame of the so-called “Normative Model”, a sufficient condition for self-balancing, that means for autonomous functioning at a steady production rate (stationary behaviour. Under some particular conditions, a simulation analysis of TSS lines could be made on non-linear block diagrams, showing that the state trajectories are piecewise continuous in between occurrences of certain discrete events, which determine their discontinuity. TSS lines may therefore be modelled as hybrid dynamic systems, more specific, with autonomous switching and autonomous impulses (jumps. A stability analysis of such manufacturing lines is allowed by modelling them as hybrid dynamic systems with discontinuous motions.

  5. Some results for the dynamic (s, S) inventory model *

    NARCIS (Netherlands)

    H.C. Tijms

    1971-01-01

    textabstractSummary The periodic review, single item, stationary (s, S) inventory model is considered. There is a fixed lead time, a linear purchase cost, a fixed set‐up cost, a holding and shortage cost function, a discount factor 0 < α≤ 1 and backlogging of unfilled demand. The solution for the

  6. Recent numerical results on the two dimensional Hubbard model

    Energy Technology Data Exchange (ETDEWEB)

    Parola, A.; Sorella, S.; Baroni, S.; Car, R.; Parrinello, M.; Tosatti, E. (SISSA, Trieste (Italy))

    1989-12-01

    A new method for simulating strongly correlated fermionic systems, has been applied to the study of the ground state properties of the 2D Hubbard model at various fillings. Comparison has been made with exact diagonalizations in the 4 x 4 lattices where very good agreement has been verified in all the correlation functions which have been studied: charge, magnetization and momentum distribution. (orig.).

  7. Analytical results for the Sznajd model of opinion formation

    Czech Academy of Sciences Publication Activity Database

    Slanina, František; Lavička, H.

    2003-01-01

    Roč. 35, - (2003), s. 279-288 ISSN 1434-6028 R&D Projects: GA ČR GA202/01/1091 Institutional research plan: CEZ:AV0Z1010914 Keywords : agent models * sociophysics Subject RIV: BE - Theoretical Physics Impact factor: 1.457, year: 2003

  8. Comparative Analysis of Bulge Deformation between 2D and 3D Finite Element Models

    Directory of Open Access Journals (Sweden)

    Qin Qin

    2014-02-01

    Full Text Available Bulge deformation of the slab is one of the main factors that affect slab quality in continuous casting. This paper describes an investigation into bulge deformation using ABAQUS to model the solidification process. A three-dimensional finite element analysis model of the slab solidification process has been first established because the bulge deformation is closely related to slab temperature distributions. Based on slab temperature distributions, a three-dimensional thermomechanical coupling model including the slab, the rollers, and the dynamic contact between them has also been constructed and applied to a case study. The thermomechanical coupling model produces outputs such as the rules of bulge deformation. Moreover, the three-dimensional model has been compared with a two-dimensional model to discuss the differences between the two models in calculating the bulge deformation. The results show that the platform zone exists in the wide side of the slab and the bulge deformation is affected strongly by the ratio of width-to-thickness. The indications are also that the difference of the bulge deformation for the two modeling ways is little when the ratio of width-to-thickness is larger than six.

  9. Comparative effectiveness of colony-stimulating factors in febrile neutropenia prophylaxis: how results are affected by research design.

    Science.gov (United States)

    Henk, Henry J; Li, Xiaoyan; Becker, Laura K; Xu, Hairong; Gong, Qi; Deeter, Robert G; Barron, Richard L

    2015-01-01

    To examine the impact of research design on results in two published comparative effectiveness studies. Guidelines for comparative effectiveness research have recommended incorporating disease process in study design. Based on the recommendations, we develop a checklist of considerations and apply the checklist in review of two published studies on comparative effectiveness of colony-stimulating factors. Both studies used similar administrative claims data, but different methods, which resulted in directionally different estimates. Major design differences between the two studies include: whether the timing of intervention in disease process was identified and whether study cohort and outcome assessment period were defined based on this temporal relationship. Disease process and timing of intervention should be incorporated into the design of comparative effectiveness studies.

  10. Multiple data sets and modelling choices in a comparative LCA of disposable beverage cups.

    Science.gov (United States)

    van der Harst, Eugenie; Potting, José; Kroeze, Carolien

    2014-10-01

    This study used multiple data sets and modelling choices in an environmental life cycle assessment (LCA) to compare typical disposable beverage cups made from polystyrene (PS), polylactic acid (PLA; bioplastic) and paper lined with bioplastic (biopaper). Incineration and recycling were considered as waste processing options, and for the PLA and biopaper cup also composting and anaerobic digestion. Multiple data sets and modelling choices were systematically used to calculate average results and the spread in results for each disposable cup in eleven impact categories. The LCA results of all combinations of data sets and modelling choices consistently identify three processes that dominate the environmental impact: (1) production of the cup's basic material (PS, PLA, biopaper), (2) cup manufacturing, and (3) waste processing. The large spread in results for impact categories strongly overlaps among the cups, however, and therefore does not allow a preference for one type of cup material. Comparison of the individual waste treatment options suggests some cautious preferences. The average waste treatment results indicate that recycling is the preferred option for PLA cups, followed by anaerobic digestion and incineration. Recycling is slightly preferred over incineration for the biopaper cups. There is no preferred waste treatment option for the PS cups. Taking into account the spread in waste treatment results for all cups, however, none of these preferences for waste processing options can be justified. The only exception is composting, which is least preferred for both PLA and biopaper cups. Our study illustrates that using multiple data sets and modelling choices can lead to considerable spread in LCA results. This makes comparing products more complex, but the outcomes more robust. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Phase Partitioning of Common Alcohols With BTEX Compounds in Water: Comparison Between Modeling and Experimental Results

    Science.gov (United States)

    Lee, K. Y.

    2007-12-01

    This study compares the modeling and experimental results on the equilibrium phase partitioning behavior of three common alcohols (ethanol, isopropanol, and methanol) in a two-phase system consisting of water and a BTEX compound. A previously developed computer program is used to generate ternary phase diagrams for each alcohol-water-NAPL mixture combination, where the required activity coefficients are estimated using the UNIFAC model. A set of laboratory experiments is conducted to determine the maximum single-phase water content for every alcohol-water-NAPL mixture combination considered in this study, where the initial volume composition is 85 percent alcohol and 15 percent NAPL. Comparison of experimental results against UNIFAC- derived modeling results shows good agreement for mixtures containing ethanol and methanol, but relatively poor agreement for mixtures containing isopropanol.

  12. Latest results from the EU project AVATAR: Aerodynamic modelling of 10 MW wind turbines

    DEFF Research Database (Denmark)

    Schepers O. Ceyhan, J. G.; Boorsma, K.; Gonzalez, A.

    2016-01-01

    This paper presents the most recent results from the EU project AVATAR in which aerodynamic models are improved and validated for wind turbines on a scale of 10 MW and more. Measurements on a DU 00-W-212 airfoil are presented which have been taken in the pressurized DNW-HDG wind tunnel up...... to a Reynolds number of 15 Million. These measurements are compared with measurements in the LM wind tunnel for Reynolds numbers of 3 and 6 Million and with calculational results. In the analysis of results special attention is paid to high Reynolds numbers effects. CFD calculations on airfoil performance...... results from 3D rotor models where a comparison is made between results from vortex wake methods and BEM methods at yawed conditions....

  13. Dynamic model of the electrorheological fluid based on measurement results

    International Nuclear Information System (INIS)

    Krivenkov, K; Ulrich, S; Bruns, R

    2013-01-01

    To develop modern applications for vibration decoupling based on electrorheological fluids with suitable control strategies, an appropriate mathematical model of the ERF is necessary. The devices mostly used have annular-shape electrorheological valves. This requires the use of flow channels to measure the static and dynamic properties of the electrorheological fluids in similar flow conditions. Particularly for the identification of the dynamic behavior of the fluids, the influences of the non-electrorheological properties on the overall system must be taken into account. In this contribution three types of parameters with several nonlinear dependencies for the mapping of the static and dynamic properties of the ERF are considered: electro-rheological, hydraulic and electrical. The mathematical model introduced can precisely demonstrate the static and dynamic behavior of the electrorheological fluid and can be used for the future design of real systems for vibration decoupling or other systems with high dynamic requirements.

  14. Comparing regional precipitation and temperature extremes in climate model and reanalysis products

    Directory of Open Access Journals (Sweden)

    Oliver Angélil

    2016-09-01

    Full Text Available A growing field of research aims to characterise the contribution of anthropogenic emissions to the likelihood of extreme weather and climate events. These analyses can be sensitive to the shapes of the tails of simulated distributions. If tails are found to be unrealistically short or long, the anthropogenic signal emerges more or less clearly, respectively, from the noise of possible weather. Here we compare the chance of daily land-surface precipitation and near-surface temperature extremes generated by three Atmospheric Global Climate Models typically used for event attribution, with distributions from six reanalysis products. The likelihoods of extremes are compared for area-averages over grid cell and regional sized spatial domains. Results suggest a bias favouring overly strong attribution estimates for hot and cold events over many regions of Africa and Australia, and a bias favouring overly weak attribution estimates over regions of North America and Asia. For rainfall, results are more sensitive to geographic location. Although the three models show similar results over many regions, they do disagree over others. Equally, results highlight the discrepancy amongst reanalyses products. This emphasises the importance of using multiple reanalysis and/or observation products, as well as multiple models in event attribution studies.

  15. 1-g model loading tests: methods and results

    Czech Academy of Sciences Publication Activity Database

    Feda, Jaroslav

    1999-01-01

    Roč. 2, č. 4 (1999), s. 371-381 ISSN 1436-6517. [Int.Conf. on Soil - Structure Interaction in Urban Civ. Engineering. Darmstadt, 08.10.1999-09.10.1999] R&D Projects: GA MŠk OC C7.10 Keywords : shallow foundation * model tests * sandy subsoil * bearing capacity * subsoil failure * volume deformation Subject RIV: JM - Building Engineering

  16. Comparing in Cylinder Pressure Modelling of a DI Diesel Engine Fuelled on Alternative Fuel Using Two Tabulated Chemistry Approaches.

    Science.gov (United States)

    Ngayihi Abbe, Claude Valery; Nzengwa, Robert; Danwe, Raidandi

    2014-01-01

    The present work presents the comparative simulation of a diesel engine fuelled on diesel fuel and biodiesel fuel. Two models, based on tabulated chemistry, were implemented for the simulation purpose and results were compared with experimental data obtained from a single cylinder diesel engine. The first model is a single zone model based on the Krieger and Bormann combustion model while the second model is a two-zone model based on Olikara and Bormann combustion model. It was shown that both models can predict well the engine's in-cylinder pressure as well as its overall performances. The second model showed a better accuracy than the first, while the first model was easier to implement and faster to compute. It was found that the first method was better suited for real time engine control and monitoring while the second one was better suited for engine design and emission prediction.

  17. Sharing brain mapping statistical results with the neuroimaging data model

    Science.gov (United States)

    Maumet, Camille; Auer, Tibor; Bowring, Alexander; Chen, Gang; Das, Samir; Flandin, Guillaume; Ghosh, Satrajit; Glatard, Tristan; Gorgolewski, Krzysztof J.; Helmer, Karl G.; Jenkinson, Mark; Keator, David B.; Nichols, B. Nolan; Poline, Jean-Baptiste; Reynolds, Richard; Sochat, Vanessa; Turner, Jessica; Nichols, Thomas E.

    2016-01-01

    Only a tiny fraction of the data and metadata produced by an fMRI study is finally conveyed to the community. This lack of transparency not only hinders the reproducibility of neuroimaging results but also impairs future meta-analyses. In this work we introduce NIDM-Results, a format specification providing a machine-readable description of neuroimaging statistical results along with key image data summarising the experiment. NIDM-Results provides a unified representation of mass univariate analyses including a level of detail consistent with available best practices. This standardized representation allows authors to relay methods and results in a platform-independent regularized format that is not tied to a particular neuroimaging software package. Tools are available to export NIDM-Result graphs and associated files from the widely used SPM and FSL software packages, and the NeuroVault repository can import NIDM-Results archives. The specification is publically available at: http://nidm.nidash.org/specs/nidm-results.html. PMID:27922621

  18. Bayesian meta-analysis models for microarray data: a comparative study

    Directory of Open Access Journals (Sweden)

    Song Joon J

    2007-03-01

    Full Text Available Abstract Background With the growing abundance of microarray data, statistical methods are increasingly needed to integrate results across studies. Two common approaches for meta-analysis of microarrays include either combining gene expression measures across studies or combining summaries such as p-values, probabilities or ranks. Here, we compare two Bayesian meta-analysis models that are analogous to these methods. Results Two Bayesian meta-analysis models for microarray data have recently been introduced. The first model combines standardized gene expression measures across studies into an overall mean, accounting for inter-study variability, while the second combines probabilities of differential expression without combining expression values. Both models produce the gene-specific posterior probability of differential expression, which is the basis for inference. Since the standardized expression integration model includes inter-study variability, it may improve accuracy of results versus the probability integration model. However, due to the small number of studies typical in microarray meta-analyses, the variability between studies is challenging to estimate. The probability integration model eliminates the need to model variability between studies, and thus its implementation is more straightforward. We found in simulations of two and five studies that combining probabilities outperformed combining standardized gene expression measures for three comparison values: the percent of true discovered genes in meta-analysis versus individual studies; the percent of true genes omitted in meta-analysis versus separate studies, and the number of true discovered genes for fixed levels of Bayesian false discovery. We identified similar results when pooling two independent studies of Bacillus subtilis. We assumed that each study was produced from the same microarray platform with only two conditions: a treatment and control, and that the data sets

  19. The development of substance use in adolescence: results from comparing two longitudinal studies in England and Germany

    Directory of Open Access Journals (Sweden)

    Mariotti Luca

    2011-07-01

    Full Text Available This paper compares the development of alcohol and cannabis use in two English and German adolescent cohorts, using longitudinal data from ongoing studies located in Peterborough and Duisburg respectively. We set out the two studies and detail the steps taken to make the comparisons presented. Unusually, this paper assesses this development simultaneously in both cohorts, using an under-utilized variation of a well-known technique (multiple-group multiple-cohort latent growth curve modelling. In keeping with expectations from other research, there are large differences in the proportions of young people in the two countries using cannabis and alcohol. The Peterborough cohort embarked on earlier initiation of both alcohol and cannabis use, and increase their frequency of use very quickly. Despite a one year chronological gap between the two study cohorts, the 13 year old Peterborough group drink (until drunk and smoke cannabis at the same level as the 15 year old versions of their German counterparts. Although there are some methodological differences between the two projects, the results appear to be valid.In questo articolo viene svolta una comparazione sullo sviluppo, nel corso dell’adolescenza, del consumo di droghe leggere e alcol tra un campione di giovani tedeschi e inglesi, utilizzando i dati di due studi longitudinali panel condotti rispettivamente in Germania e in Inghilterra. Per questo confronto viene utilizzata una tecnica particolare (multiple-group multiple-cohort latent growth curve modelling che permette di osservare similitudini e differenze nello sviluppo individuale del consumo di queste sostanze nel corso del tempo, con un’attenzione particolare alle differenze tra le due coorti. Nonostante alcune differenze di tipo metodologico tra i due studi, e comunque in sintonia con studi precedenti, si notano importanti differenze tra i due campioni. Il campione inglese infatti mostra un livello di consumo più alto rispetto a

  20. DISCRETE DEFORMATION WAVE DYNAMICS IN SHEAR ZONES: PHYSICAL MODELLING RESULTS

    Directory of Open Access Journals (Sweden)

    S. A. Bornyakov

    2016-01-01

    Full Text Available Observations of earthquake migration along active fault zones [Richter, 1958; Mogi, 1968] and related theoretical concepts [Elsasser, 1969] have laid the foundation for studying the problem of slow deformation waves in the lithosphere. Despite the fact that this problem has been under study for several decades and discussed in numerous publications, convincing evidence for the existence of deformation waves is still lacking. One of the causes is that comprehensive field studies to register such waves by special tools and equipment, which require sufficient organizational and technical resources, have not been conducted yet.The authors attempted at finding a solution to this problem by physical simulation of a major shear zone in an elastic-viscous-plastic model of the lithosphere. The experiment setup is shown in Figure 1 (A. The model material and boundary conditions were specified in accordance with the similarity criteria (described in detail in [Sherman, 1984; Sherman et al., 1991; Bornyakov et al., 2014]. The montmorillonite clay-and-water paste was placed evenly on two stamps of the installation and subject to deformation as the active stamp (1 moved relative to the passive stamp (2 at a constant speed. The upper model surface was covered with fine sand in order to get high-contrast photos. Photos of an emerging shear zone were taken every second by a Basler acA2000-50gm digital camera. Figure 1 (B shows an optical image of a fragment of the shear zone. The photos were processed by the digital image correlation method described in [Sutton et al., 2009]. This method estimates the distribution of components of displacement vectors and strain tensors on the model surface and their evolution over time [Panteleev et al., 2014, 2015].Strain fields and displacements recorded in the optical images of the model surface were estimated in a rectangular box (220.00×72.17 mm shown by a dot-and-dash line in Fig. 1, A. To ensure a sufficient level of

  1. Cognitive models of choice: comparing decision field theory to the proportional difference model.

    Science.gov (United States)

    Scheibehenne, Benjamin; Rieskamp, Jörg; González-Vallejo, Claudia

    2009-07-01

    People often face preferential decisions under risk. To further our understanding of the cognitive processes underlying these preferential choices, two prominent cognitive models, decision field theory (DFT; Busemeyer & Townsend, 1993) and the proportional difference model (PD; González-Vallejo, 2002), were rigorously tested against each other. In two consecutive experiments, the participants repeatedly had to choose between monetary gambles. The first experiment provided the reference to estimate the models' free parameters. From these estimations, new gamble pairs were generated for the second experiment such that the two models made maximally divergent predictions. In the first experiment, both models explained the data equally well. However, in the second generalization experiment, the participants' choices were much closer to the predictions of DFT. The results indicate that the stochastic process assumed by DFT, in which evidence in favor of or against each option accumulates over time, described people's choice behavior better than the trade-offs between proportional differences assumed by PD. Copyright © 2009 Cognitive Science Society, Inc.

  2. Constraining performance assessment models with tracer test results: a comparison between two conceptual models

    Science.gov (United States)

    McKenna, Sean A.; Selroos, Jan-Olof

    Tracer tests are conducted to ascertain solute transport parameters of a single rock feature over a 5-m transport pathway. Two different conceptualizations of double-porosity solute transport provide estimates of the tracer breakthrough curves. One of the conceptualizations (single-rate) employs a single effective diffusion coefficient in a matrix with infinite penetration depth. However, the tracer retention between different flow paths can vary as the ratio of flow-wetted surface to flow rate differs between the path lines. The other conceptualization (multirate) employs a continuous distribution of multiple diffusion rate coefficients in a matrix with variable, yet finite, capacity. Application of these two models with the parameters estimated on the tracer test breakthrough curves produces transport results that differ by orders of magnitude in peak concentration and time to peak concentration at the performance assessment (PA) time and length scales (100,000 years and 1,000 m). These differences are examined by calculating the time limits for the diffusive capacity to act as an infinite medium. These limits are compared across both conceptual models and also against characteristic times for diffusion at both the tracer test and PA scales. Additionally, the differences between the models are examined by re-estimating parameters for the multirate model from the traditional double-porosity model results at the PA scale. Results indicate that for each model the amount of the diffusive capacity that acts as an infinite medium over the specified time scale explains the differences between the model results and that tracer tests alone cannot provide reliable estimates of transport parameters for the PA scale. Results of Monte Carlo runs of the transport models with varying travel times and path lengths show consistent results between models and suggest that the variation in flow-wetted surface to flow rate along path lines is insignificant relative to variability in

  3. A Comparative Study of the Proposed Models for the Components of the National Health Information System

    Science.gov (United States)

    Ahmadi, Maryam; Damanabi, Shahla; Sadoughi, Farahnaz

    2014-01-01

    Introduction: National Health Information System plays an important role in ensuring timely and reliable access to Health information, which is essential for strategic and operational decisions that improve health, quality and effectiveness of health care. In other words, using the National Health information system you can improve the quality of health data, information and knowledge used to support decision making at all levels and areas of the health sector. Since full identification of the components of this system – for better planning and management influential factors of performanceseems necessary, therefore, in this study different attitudes towards components of this system are explored comparatively. Methods: This is a descriptive and comparative kind of study. The society includes printed and electronic documents containing components of the national health information system in three parts: input, process and output. In this context, search for information using library resources and internet search were conducted, and data analysis was expressed using comparative tables and qualitative data. Results: The findings showed that there are three different perspectives presenting the components of national health information system Lippeveld and Sauerborn and Bodart model in 2000, Health Metrics Network (HMN) model from World Health Organization in 2008, and Gattini’s 2009 model. All three models outlined above in the input (resources and structure) require components of management and leadership, planning and design programs, supply of staff, software and hardware facilities and equipment. Plus, in the “process” section from three models, we pointed up the actions ensuring the quality of health information system, and in output section, except for Lippeveld Model, two other models consider information products and use and distribution of information as components of the national health information system. Conclusion: the results showed that all the

  4. Comparative testing of dark matter models with 15 HSB and 15 LSB galaxies

    Science.gov (United States)

    Kun, E.; Keresztes, Z.; Simkó, A.; Szűcs, G.; Gergely, L. Á.

    2017-12-01

    Context. We assemble a database of 15 high surface brightness (HSB) and 15 low surface brightness (LSB) galaxies, for which surface brightness density and spectroscopic rotation curve data are both available and representative for various morphologies. We use this dataset to test the Navarro-Frenk-White, the Einasto, and the pseudo-isothermal sphere dark matter models. Aims: We investigate the compatibility of the pure baryonic model and baryonic plus one of the three dark matter models with observations on the assembled galaxy database. When a dark matter component improves the fit with the spectroscopic rotational curve, we rank the models according to the goodness of fit to the datasets. Methods: We constructed the spatial luminosity density of the baryonic component based on the surface brightness profile of the galaxies. We estimated the mass-to-light (M/L) ratio of the stellar component through a previously proposed color-mass-to-light ratio relation (CMLR), which yields stellar masses independent of the photometric band. We assumed an axissymetric baryonic mass model with variable axis ratios together with one of the three dark matter models to provide the theoretical rotational velocity curves, and we compared them with the dataset. In a second attempt, we addressed the question whether the dark component could be replaced by a pure baryonic model with fitted M/L ratios, varied over ranges consistent with CMLR relations derived from the available stellar population models. We employed the Akaike information criterion to establish the performance of the best-fit models. Results: For 7 galaxies (2 HSB and 5 LSB), neither model fits the dataset within the 1σ confidence level. For the other 23 cases, one of the models with dark matter explains the rotation curve data best. According to the Akaike information criterion, the pseudo-isothermal sphere emerges as most favored in 14 cases, followed by the Navarro-Frenk-White (6 cases) and the Einasto (3 cases) dark

  5. Using RosettaLigand for small molecule docking into comparative models.

    Directory of Open Access Journals (Sweden)

    Kristian W Kaufmann

    Full Text Available Computational small molecule docking into comparative models of proteins is widely used to query protein function and in the development of small molecule therapeutics. We benchmark RosettaLigand docking into comparative models for nine proteins built during CASP8 that contain ligands. We supplement the study with 21 additional protein/ligand complexes to cover a wider space of chemotypes. During a full docking run in 21 of the 30 cases, RosettaLigand successfully found a native-like binding mode among the top ten scoring binding modes. From the benchmark cases we find that careful template selection based on ligand occupancy provides the best chance of success while overall sequence identity between template and target do not appear to improve results. We also find that binding energy normalized by atom number is often less than -0.4 in native-like binding modes.

  6. Beware the black box: investigating the sensitivity of FEA simulations to modelling factors in comparative biomechanics

    Directory of Open Access Journals (Sweden)

    Christopher W. Walmsley

    2013-11-01

    Full Text Available Finite element analysis (FEA is a computational technique of growing popularity in the field of comparative biomechanics, and is an easily accessible platform for form-function analyses of biological structures. However, its rapid evolution in recent years from a novel approach to common practice demands some scrutiny in regards to the validity of results and the appropriateness of assumptions inherent in setting up simulations. Both validation and sensitivity analyses remain unexplored in many comparative analyses, and assumptions considered to be ‘reasonable’ are often assumed to have little influence on the results and their interpretation.Here we report an extensive sensitivity analysis where high resolution finite element (FE models of mandibles from seven species of crocodile were analysed under loads typical for comparative analysis: biting, shaking, and twisting. Simulations explored the effect on both the absolute response and the interspecies pattern of results to variations in commonly used input parameters. Our sensitivity analysis focuses on assumptions relating to the selection of material properties (heterogeneous or homogeneous, scaling (standardising volume, surface area, or length, tooth position (front, mid, or back tooth engagement, and linear load case (type of loading for each feeding type.Our findings show that in a comparative context, FE models are far less sensitive to the selection of material property values and scaling to either volume or surface area than they are to those assumptions relating to the functional aspects of the simulation, such as tooth position and linear load case. Results show a complex interaction between simulation assumptions, depending on the combination of assumptions and the overall shape of each specimen. Keeping assumptions consistent between models in an analysis does not ensure that results can be generalised beyond the specific set of assumptions used. Logically, different

  7. Feedforward Object-Vision Models Only Tolerate Small Image Variations Compared to Human

    Directory of Open Access Journals (Sweden)

    Masoud eGhodrati

    2014-07-01

    Full Text Available Invariant object recognition is a remarkable ability of primates' visual system that its underlying mechanism has constantly been under intense investigations. Computational modelling is a valuable tool toward understanding the processes involved in invariant object recognition. Although recent computational models have shown outstanding performances on challenging image databases, they fail to perform well when images with more complex variations of the same object are applied to them. Studies have shown that making sparse representation of objects by extracting more informative visual features through a feedforward sweep can lead to higher recognition performances. Here, however, we show that when the complexity of image variations is high, even this approach results in poor performance compared to humans. To assess the performance of models and humans in invariant object recognition tasks, we built a parametrically controlled image database consisting of several object categories varied in different dimensions and levels, rendered from 3D planes. Comparing the performance of several object recognition models with human observers shows that only in low-level image variations the models perform similar to humans in categorization tasks. Furthermore, the results of our behavioral experiments demonstrate that, even under difficult experimental conditions (i.e. briefly presented masked stimuli with complex image variations, human observers performed outstandingly well, suggesting that the models are still far from resembling humans in invariant object recognition. Taken together, we suggest that learning sparse informative visual features, although desirable, is not a complete solution for future progresses in object-vision modelling. We show that this approach is not of significant help in solving the computational crux of object recognition (that is invariant object recognition when the identity-preserving image variations become more complex.

  8. A comparative study of slope failure prediction using logistic regression, support vector machine and least square support vector machine models

    Science.gov (United States)

    Zhou, Lim Yi; Shan, Fam Pei; Shimizu, Kunio; Imoto, Tomoaki; Lateh, Habibah; Peng, Koay Swee

    2017-08-01

    A comparative study of logistic regression, support vector machine (SVM) and least square support vector machine (LSSVM) models has been done to predict the slope failure (landslide) along East-West Highway (Gerik-Jeli). The effects of two monsoon seasons (southwest and northeast) that occur in Malaysia are considered in this study. Two related factors of occurrence of slope failure are included in this study: rainfall and underground water. For each method, two predictive models are constructed, namely SOUTHWEST and NORTHEAST models. Based on the results obtained from logistic regression models, two factors (rainfall and underground water level) contribute to the occurrence of slope failure. The accuracies of the three statistical models for two monsoon seasons are verified by using Relative Operating Characteristics curves. The validation results showed that all models produced prediction of high accuracy. For the results of SVM and LSSVM, the models using RBF kernel showed better prediction compared to the models using linear kernel. The comparative results showed that, for SOUTHWEST models, three statistical models have relatively similar performance. For NORTHEAST models, logistic regression has the best predictive efficiency whereas the SVM model has the second best predictive efficiency.

  9. MCNP Modeling Results for Location of Buried TRU Waste Drums

    International Nuclear Information System (INIS)

    Steinman, D K; Schweitzer, J S

    2006-01-01

    In the 1960's, fifty-five gallon drums of TRU waste were buried in shallow pits on remote U.S. Government facilities such as the Idaho National Engineering Laboratory (now split into the Idaho National Laboratory and the Idaho Completion Project [ICP]). Subsequently, it was decided to remove the drums and the material that was in them from the burial pits and send the material to the Waste Isolation Pilot Plant in New Mexico. Several technologies have been tried to locate the drums non-intrusively with enough precision to minimize the chance for material to be spread into the environment. One of these technologies is the placement of steel probe holes in the pits into which wireline logging probes can be lowered to measure properties and concentrations of material surrounding the probe holes for evidence of TRU material. There is also a concern that large quantities of volatile organic compounds (VOC) are also present that would contaminate the environment during removal. In 2001, the Idaho National Engineering and Environmental Laboratory (INEEL) built two pulsed neutron wireline logging tools to measure TRU and VOC around the probe holes. The tools are the Prompt Fission Neutron (PFN) and the Pulsed Neutron Gamma (PNG), respectively. They were tested experimentally in surrogate test holes in 2003. The work reported here estimates the performance of the tools using Monte-Carlo modelling prior to field deployment. A MCNP model was constructed by INEEL personnel. It was modified by the authors to assess the ability of the tools to predict quantitatively the position and concentration of TRU and VOC materials disposed around the probe holes. The model was used to simulate the tools scanning the probe holes vertically in five centimetre increments. A drum was included in the model that could be placed near the probe hole and at other locations out to forty-five centimetres from the probe-hole in five centimetre increments. Scans were performed with no chlorine in the

  10. NASA Air Force Cost Model (NAFCOM): Capabilities and Results

    Science.gov (United States)

    McAfee, Julie; Culver, George; Naderi, Mahmoud

    2011-01-01

    NAFCOM is a parametric estimating tool for space hardware. Uses cost estimating relationships (CERs) which correlate historical costs to mission characteristics to predict new project costs. It is based on historical NASA and Air Force space projects. It is intended to be used in the very early phases of a development project. NAFCOM can be used at the subsystem or component levels and estimates development and production costs. NAFCOM is applicable to various types of missions (crewed spacecraft, uncrewed spacecraft, and launch vehicles). There are two versions of the model: a government version that is restricted and a contractor releasable version.

  11. Solar activity variations of ionosonde measurements and modeling results

    Czech Academy of Sciences Publication Activity Database

    Altadill, D.; Arrazola, D.; Blanch, E.; Burešová, Dalia

    2008-01-01

    Roč. 42, č. 4 (2008), s. 610-616 ISSN 0273-1177 R&D Projects: GA AV ČR 1QS300120506 Grant - others:MCYT(ES) REN2003-08376-C02-02; CSIC(XE) 2004CZ0002; AGAUR(XE) 2006BE00112; AF Research Laboratory(XE) FA8718-L-0072 Institutional research plan: CEZ:AV0Z30420517 Keywords : mid-latitude ionosphere * bottomside modeling * ionospheric variability Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 0.860, year: 2008 http://www.sciencedirect.com/science/journal/02731177

  12. Characteristics of the Inner and Middle Magnetosphere: Results From the Coupled Michigan MHD Model and the Rice Convection Model

    Science.gov (United States)

    De Zeeuw, D.; Sazykin, S.; Wolf, D.; Gombosi, T.; Powell, K.

    2002-05-01

    A new high performance Rice Convection Model (RCM) has been coupled to the adaptive-grid Michigan MHD model (BATSRUS). This fully coupled code allows us to self-consistently simulate the physics in the inner and middle magnetosphere. A study will be presented of the basic characteristics of the inner and middle magnetosphere in the context of a single coupled-code run with steady inputs. The analysis will include region-2 currents, shielding of the inner magnetosphere, partial ring currents, pressure distribution, magnetic field inflation, and distribution of pV**gamma. The coupled-code simulation will be compared with results from RCM runs and algorithms.

  13. Comparing Models of Nature of Science Dimensionality Based on the Next Generation Science Standards

    Science.gov (United States)

    Harrison, George M.; Seraphin, Kanesa Duncan; Philippoff, Joanna; Vallin, Lisa M.; Brandon, Paul R.

    2015-05-01

    Instruments measuring understanding of the nature of science (NOS) are required if educational institutions intend to use benchmarks or examine the effects of interventions targeting students' NOS development. Compared to other constructs, NOS understanding is complex, having been the subject of debate among scholars in both its substance and its dimensionality. This complexity invites challenges in defining what is to be measured. Drawing from the perspective that policy reform documents provide pragmatic consensus-based definitions of NOS, this study investigated how well the dimensionality described in the NOS component of the Next Generation Science Standards (NGSS) framework matched the empirical structure of data collected from a set of secondary-school students' responses to an NOS instrument comprising multiple-choice and Likert-scale items. Using multidimensional item response modeling to compare structures of NOS dimensionality, we found that treating NOS as comprising multiple dimensions-as defined by the themes in the NGSS NOS framework-resulted in a better fitting model than when treating NOS as a single dimension. The multidimensional model also had fewer poorly functioning items and revealed NOS profiles that otherwise would have been masked in a model treating NOS as a single dimension. These results provide support for the NOS NGSS framework and contribute to the ongoing discussion about the dimensionality of NOS.

  14. Alfven waves in the auroral ionosphere: A numerical model compared with measurements

    International Nuclear Information System (INIS)

    Knudsen, D.J.; Kelley, M.C.; Vickrey, J.F.

    1992-01-01

    The authors solve a linear numerical model of Alfven waves reflecting from the high-latitude ionosphere, both to better understanding the role of the ionosphere in the magnetosphere/ionosphere coupling process and to compare model results with in situ measurements. They use the model to compute the frequency-dependent amplitude and phase relations between the meridional electric and the zonal magnetic fields due to Alfven waves. These relations are compared with measurements taken by an auroral sounding rocket flow in the morningside oval and by the HILAT satellite traversing the oval at local noon. The sounding rocket's trajectory was mostly parallel to the auroral oval, and is measured enhanced fluctuating field energy in regions of electron precipitation. The rocket-measured phase data are in excellent agreement with the Alfven wave model, and the relation between the modeled and the measured by HILAT are related by the height-integrated Pedersen conductivity Σ p , indicating that the measured field fluctuations were due mainly to structured field-aligned current systems. A reason for the relative lack of Alfven wave energy in the HILAT measurements could be the fact that the satellite traveled mostly perpendicular to the oval and therefore quickly traversed narrow regions of electron precipitation and associated wave activity

  15. Climate change adaptation: Comparing climate model projections of flooding against flood estimation by continuous simulation

    Science.gov (United States)

    Smith, A.; Bates, P. D.; Freer, J. E.

    2012-12-01

    Modelled assessments of climate change impacts on flooding are now increasingly used to inform adaptation and mitigation policy. These modelled assessments are typically driven by Global and Regional Climate Models (GCM/RCM). However, opinion is divided on how best to proceed, particularly with regards to the feasibility and practicality of using climate model outputs to inform management strategies. Here RCM driven projections of extreme discharges are compared against the uncertainty present in the observed record. The run-off model HBV_light is applied, within the Generalised Likelihood Uncertainty Estimation (GLUE) framework, to the Upper Avon catchment in the Midlands of England, in the U.K. A 48 year observational record of rainfall and discharge was used, with non-behavioural parameter sets being rejected through an evaluation of continuous hydrograph simulation and annual maximum discharge. The output of an RCM ensemble was used, with differing ensemble approaches, to assess climate change impacts on extreme discharge. A daily stochastic rainfall generator was then applied to the observational record and used to simulate 2000 years of discharge. RCM driven changes in extreme discharge could then be compared against the variability present in the observed record. The results suggest that coping with present uncertainty in the observed record is already a significant challenge, with the range of uncertainty in a 1 in 100 year event eclipsing the uncertainty present in climate projections.

  16. Updating Finite Element Model of a Wind Turbine Blade Section Using Experimental Modal Analysis Results

    Directory of Open Access Journals (Sweden)

    Marcin Luczak

    2014-01-01

    Full Text Available This paper presents selected results and aspects of the multidisciplinary and interdisciplinary research oriented for the experimental and numerical study of the structural dynamics of a bend-twist coupled full scale section of a wind turbine blade structure. The main goal of the conducted research is to validate finite element model of the modified wind turbine blade section mounted in the flexible support structure accordingly to the experimental results. Bend-twist coupling was implemented by adding angled unidirectional layers on the suction and pressure side of the blade. Dynamic test and simulations were performed on a section of a full scale wind turbine blade provided by Vestas Wind Systems A/S. The numerical results are compared to the experimental measurements and the discrepancies are assessed by natural frequency difference and modal assurance criterion. Based on sensitivity analysis, set of model parameters was selected for the model updating process. Design of experiment and response surface method was implemented to find values of model parameters yielding results closest to the experimental. The updated finite element model is producing results more consistent with the measurement outcomes.

  17. Comparing stochastic differential equations and agent-based modelling and simulation for early-stage cancer.

    Science.gov (United States)

    Figueredo, Grazziela P; Siebers, Peer-Olaf; Owen, Markus R; Reps, Jenna; Aickelin, Uwe

    2014-01-01

    There is great potential to be explored regarding the use of agent-based modelling and simulation as an alternative paradigm to investigate early-stage cancer interactions with the immune system. It does not suffer from some limitations of ordinary differential equation models, such as the lack of stochasticity, representation of individual behaviours rather than aggregates and individual memory. In this paper we investigate the potential contribution of agent-based modelling and simulation when contrasted with stochastic versions of ODE models using early-stage cancer examples. We seek answers to the following questions: (1) Does this new stochastic formulation produce similar results to the agent-based version? (2) Can these methods be used interchangeably? (3) Do agent-based models outcomes reveal any benefit when compared to the Gillespie results? To answer these research questions we investigate three well-established mathematical models describing interactions between tumour cells and immune elements. These case studies were re-conceptualised under an agent-based perspective and also converted to the Gillespie algorithm formulation. Our interest in this work, therefore, is to establish a methodological discussion regarding the usability of different simulation approaches, rather than provide further biological insights into the investigated case studies. Our results show that it is possible to obtain equivalent models that implement the same mechanisms; however, the incapacity of the Gillespie algorithm to retain individual memory of past events affects the similarity of some results. Furthermore, the emergent behaviour of ABMS produces extra patters of behaviour in the system, which was not obtained by the Gillespie algorithm.

  18. Verification of simulation model with COBRA-IIIP code by confrontment of experimental results

    International Nuclear Information System (INIS)

    Silva Galetti, M.R. da; Pontedeiro, A.C.; Oliveira Barroso, A.C. de

    1985-01-01

    It is presented an evaluation of the COBRA IIIP/MIT code (of thermal hydraulic analysis by subchannels), comparing their results with experimental data obtained in stationary and transient regimes. It was done a study to calculate the spatial and temporal critical heat flux. It is presented a sensitivity study of simulation model related to the turbulent mixture and the number of axial intervals. (M.C.K.) [pt

  19. Combining forming results via weld models to powerful numerical assemblies

    NARCIS (Netherlands)

    Kose, K.; Rietman, Bert

    2004-01-01

    Forming simulations generally give satisfying results with respect to thinning, stresses, changed material properties and, with a proper springback calculation, the geometric form. The joining of parts by means of welding yields an extra change of the material properties and the residual stresses.

  20. Assessing intrinsic and specific vulnerability models ability to indicate groundwater vulnerability to groups of similar pesticides: A comparative study

    Science.gov (United States)

    Douglas, Steven; Dixon, Barnali; Griffin, Dale W.

    2018-01-01

    With continued population growth and increasing use of fresh groundwater resources, protection of this valuable resource is critical. A cost effective means to assess risk of groundwater contamination potential will provide a useful tool to protect these resources. Integrating geospatial methods offers a means to quantify the risk of contaminant potential in cost effective and spatially explicit ways. This research was designed to compare the ability of intrinsic (DRASTIC) and specific (Attenuation Factor; AF) vulnerability models to indicate groundwater vulnerability areas by comparing model results to the presence of pesticides from groundwater sample datasets. A logistic regression was used to assess the relationship between the environmental variables and the presence or absence of pesticides within regions of varying vulnerability. According to the DRASTIC model, more than 20% of the study area is very highly vulnerable. Approximately 30% is very highly vulnerable according to the AF model. When groundwater concentrations of individual pesticides were compared to model predictions, the results were mixed. Model predictability improved when concentrations of the group of similar pesticides were compared to model results. Compared to the DRASTIC model, the AF model more accurately predicts the distribution of the number of contaminated wells within each vulnerability class.

  1. Atmosphere and permafrost in the Arctic: results from a new regional coupled atmosphere-land model

    Science.gov (United States)

    Matthes, Heidrun; Rinke, Annette; Zhou, Xu; Dethloff, Klaus

    2017-04-01

    Frozen ground is one of the key components of the land part of the Arctic climate system. A reliable representation of the exchanges of energy, water and gases (CO2 and CH4) between frozen ground and the atmosphere is essential for simulating the present day Arctic coupled climate system realistically and its future changes with some confidence. Regional atmosphere-snow-permafrost interactions can be best studied with Regional Climate Models (RCMs) due to their high horizontal resolution compared to Global Climate Models. For this purpose, the sophisticated land model CLM4 was integrated into the Arctic regional climate model HIRHAM5 (HIRHAM5-CLM4). To validate this model, it was run over the ERAInterim period (1979-2014) and the model results were compared to a similar simulation of HIRHAM5, using the inbuilt land model, as well as to station observations. The comparison focuses on the models ability to represent observations on permafrost like permafrost extent, active layer thickness (ALT) and soil temperature profiles, as well as on the representation of the Arctic atmosphere. The representation of ALT and soil temperature profiles is significantly improved in HIRHAM5-CLM4 compared to HIRHAM5. Averaged over the period 2000-2011, the bias to station observations of ALT is reduced from -1.3 m to -0.3 m, the Arctic wide winter soil temperature root mean square is reduced from up to 14.4K to a maximum of 5K. Arctic climatology of 2m air temperature and mean sea level pressure are well represented in both HIRHAM5-CLM4 and HIRHAM5, HIRHAM5-CLM4 reduces the air temperature bias averaged over 1979-2014 over Eastern and Central Siberia in winter by 0.5K. Using CLM4 in HIRHAM5 impacts the simulation of local circulation patterns and influences the occurrence of baroclinic cyclones.

  2. Comparison of the 1981 INEL dispersion data with results from a number of different models

    Energy Technology Data Exchange (ETDEWEB)

    Lewellen, W S; Sykes, R I; Parker, S F

    1985-05-01

    The results from simulations by 12 different dispersion models are compared with observations from an extensive field experiment conducted by the Nuclear Regulatory Commission at the Idaho National Engineering Laboratory in July, 1981. Comparisons were made on the bases of hourly SF/sub 6/ samples taken at the surface, out to approximately 10 km from the 46 m release tower, both during and following 7 different 8-hour releases. Comparisons are also made for total integrated doses collected out to approximately 40 km. Three classes of models are used. Within the limited range appropriate for Class A models this data comparison shows that neither the puff models or the transport and diffusion models agree with the data any better than the simple Gaussian plume models. The puff and transport and diffusion models do show a slight edge in performance in comparison with the total dose over the extended range approximate for class B models. The best model results for the hourly samples show approximately 40% calculated within a factor of two when a 15/sup 0/ uncertainty in plume position is permitted and it is assumed that higher data samples may occur at stations between the actual sample sites. This is increased to 60% for the 12 hour integrated dose and 70% for the total integrated dose when the same performance measure is used. None of the models reproduce the observed patchy dose patterns. This patchiness is consistent with the discussion of the inherent uncertainty associated with time averaged plume observations contained in our companion reports on the scientific critique of available models.

  3. Comparative study: TQ and Lean Production ownership models in health services

    Directory of Open Access Journals (Sweden)

    Natalia Yuri Eiro

    2015-10-01

    Full Text Available Objective: compare the application of Total Quality (TQ models used in processes of a health service, cases of lean healthcare and literature from another institution that has also applied this model.Method: this is a qualitative research that was conducted through a descriptive case study.Results:through critical analysis of the institutions studied it was possible to make a comparison between the traditional quality approach checked in one case and the theoretical and practice lean production approach used in another case and the specifications are described below.Conclusion: the research identified that the lean model was better suited for people that work systemically and generate the flow. It also pointed towards some potential challenges in the introduction and implementation of lean methods in health.

  4. Model unspecific search in CMS. Results at 8 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Albert, Andreas; Duchardt, Deborah; Hebbeker, Thomas; Knutzen, Simon; Lieb, Jonas; Meyer, Arnd; Pook, Tobias; Roemer, Jonas [III. Physikalisches Institut A, RWTH Aachen University (Germany)

    2016-07-01

    In the year 2012, CMS collected a total data set of approximately 20 fb{sup -1} in proton-proton collisions at √(s)=8 TeV. Dedicated searches for physics beyond the standard model are commonly designed with the signatures of a given theoretical model in mind. While this approach allows for an optimised sensitivity to the sought-after signal, it may cause unexpected phenomena to be overlooked. In a complementary approach, the Model Unspecific Search in CMS (MUSiC) analyses CMS data in a general way. Depending on the reconstructed final state objects (e.g. electrons), collision events are sorted into classes. In each of the classes, the distributions of selected kinematic variables are compared to standard model simulation. An automated statistical analysis is performed to quantify the agreement between data and prediction. In this talk, the analysis concept is introduced and selected results of the analysis of the 2012 CMS data set are presented.

  5. 5-year results comparing mineral trioxide aggregate and adhesive resin composite for root-end sealing in apical surgery

    DEFF Research Database (Denmark)

    von Arx, Thomas; Hänni, Stefan; Jensen, Simon Storgård

    2014-01-01

    observers). Two different methods of root-end preparation and filling (primary study parameters) were to be compared (mineral trioxide aggregate [MTA] vs adhesive resin composite [COMP]) without randomization. RESULTS: A total of 271 patients and teeth from a 1-year follow-up sample of 339 could be re...

  6. Functional results following fractures of the proximal humerus. A controlled clinical study comparing two periods of immobilization

    DEFF Research Database (Denmark)

    Kristiansen, B; Angermann, P; Larsen, T K

    1989-01-01

    In order to compare 1 and 3 weeks of immobilization following proximal humeral fractures a prospective controlled trial was performed in 85 patients. Clinical follow-up according to the Neer assessment system was done after 1, 3, 6, 12, and 24 months. One week of immobilization resulted in a better...

  7. Exploring the uncertainties of early detection results: model-based interpretation of mayo lung project

    Directory of Open Access Journals (Sweden)

    Berman Barbara

    2011-03-01

    Full Text Available Abstract Background The Mayo Lung Project (MLP, a randomized controlled clinical trial of lung cancer screening conducted between 1971 and 1986 among male smokers aged 45 or above, demonstrated an increase in lung cancer survival since the time of diagnosis, but no reduction in lung cancer mortality. Whether this result necessarily indicates a lack of mortality benefit for screening remains controversial. A number of hypotheses have been proposed to explain the observed outcome, including over-diagnosis, screening sensitivity, and population heterogeneity (initial difference in lung cancer risks between the two trial arms. This study is intended to provide model-based testing for some of these important arguments. Method Using a micro-simulation model, the MISCAN-lung model, we explore the possible influence of screening sensitivity, systematic error, over-diagnosis and population heterogeneity. Results Calibrating screening sensitivity, systematic error, or over-diagnosis does not noticeably improve the fit of the model, whereas calibrating population heterogeneity helps the model predict lung cancer incidence better. Conclusions Our conclusion is that the hypothesized imperfection in screening sensitivity, systematic error, and over-diagnosis do not in themselves explain the observed trial results. Model fit improvement achieved by accounting for population heterogeneity suggests a higher risk of cancer incidence in the intervention group as compared with the control group.

  8. The Witten-Sakai-Sugimoto model: A brief review and some recent results

    Science.gov (United States)

    Rebhan, Anton

    2015-05-01

    A brief review of the Witten-Sakai-Sugimoto model is given, which is a top-down holographic model of low-energy QCD with chiral quarks derived from type-IIA superstring theory. The main predictions of the model, in particular concerning meson spectra, the gluon condensate, the QCD string tension, the mass of the η' and of baryons are discussed and compared quantitatively with available experimental and/or lattice results. Then some recent results of potential interest to the physics program at the future FAIR facility are presented: The spectrum of glueballs and their decay rates into pions, and the phase diagram of QCD at finite temperature, density, and magnetic field strength.

  9. The Witten-Sakai-Sugimoto model: A brief review and some recent results

    Directory of Open Access Journals (Sweden)

    Rebhan Anton

    2015-01-01

    Full Text Available A brief review of the Witten-Sakai-Sugimoto model is given, which is a top-down holographic model of low-energy QCD with chiral quarks derived from type-IIA superstring theory. The main predictions of the model, in particular concerning meson spectra, the gluon condensate, the QCD string tension, the mass of the η′ and of baryons are discussed and compared quantitatively with available experimental and/or lattice results. Then some recent results of potential interest to the physics program at the future FAIR facility are presented: The spectrum of glueballs and their decay rates into pions, and the phase diagram of QCD at finite temperature, density, and magnetic field strength.

  10. Influence of Different Modeling Strategies for CFRP on Finite Element Simulation Results

    Directory of Open Access Journals (Sweden)

    Liu Xueshu

    2016-01-01

    Full Text Available Numerical simulation is used to predict the behavior and response of carbon fiber reinforced plastic (CFRP. Sometimes zero thickness of interface layer is introduced into the numerical model to investigate the inter-layer behavior like delamination. To investigate the influence of critical volume-type defect like void, usually appeared in matrix rich region at the interface between layers, on mechanical properties of CFRP, numerical models with different interface thickness were created and tensile property and three-point bending simulation results were compared to experimental ones. It is found that accurate result is obtained with increasing of the interface thickness and up to 20% that of layer thickness is recommended to model the matrix rich region.

  11. A comparative study of two prediction models for brain tumor progression

    Science.gov (United States)

    Zhou, Deqi; Tran, Loc; Wang, Jihong; Li, Jiang

    2015-03-01

    calculated as average over the four patients. Experimental results show that both the manifold learning and deep neural network models produced better results compared to using raw data and principle component analysis (PCA), and the deep learning model is a better method than manifold learning on this data set. The averaged sensitivity and specificity by deep learning are comparable with these by the manifold learning approach while its precision is considerably higher. This means that the predicted abnormal points by deep learning are more likely to correspond to the actual progression region.

  12. A comparative study of the proposed models for the components of the national health information system.

    Science.gov (United States)

    Ahmadi, Maryam; Damanabi, Shahla; Sadoughi, Farahnaz

    2014-04-01

    National Health Information System plays an important role in ensuring timely and reliable access to Health information, which is essential for strategic and operational decisions that improve health, quality and effectiveness of health care. In other words, using the National Health information system you can improve the quality of health data, information and knowledge used to support decision making at all levels and areas of the health sector. Since full identification of the components of this system - for better planning and management influential factors of performanceseems necessary, therefore, in this study different attitudes towards components of this system are explored comparatively. This is a descriptive and comparative kind of study. The society includes printed and electronic documents containing components of the national health information system in three parts: input, process and output. In this context, search for information using library resources and internet search were conducted, and data analysis was expressed using comparative tables and qualitative data. The findings showed that there are three different perspectives presenting the components of national health information system Lippeveld and Sauerborn and Bodart model in 2000, Health Metrics Network (HMN) model from World Health Organization in 2008, and Gattini's 2009 model. All three models outlined above in the input (resources and structure) require components of management and leadership, planning and design programs, supply of staff, software and hardware facilities and equipment. Plus, in the "process" section from three models, we pointed up the actions ensuring the quality of health information system, and in output section, except for Lippeveld Model, two other models consider information products and use and distribution of information as components of the national health information system. the results showed that all the three models have had a brief discussion about the

  13. Results of an interactively coupled atmospheric chemistry - general circulation model. Comparison with observations

    Energy Technology Data Exchange (ETDEWEB)

    Hein, R.; Dameris, M.; Schnadt, C. [and others

    2000-01-01

    An interactively coupled climate-chemistry model which enables a simultaneous treatment of meteorology and atmospheric chemistry and their feedbacks is presented. This is the first model, which interactively combines a general circulation model based on primitive equations with a rather complex model of stratospheric and tropospheric chemistry, and which is computational efficient enough to allow long-term integrations with currently available computer resources. The applied model version extends from the Earth's surface up to 10 hPa with a relatively high number (39) of vertical levels. We present the results of a present-day (1990) simulation and compare it to available observations. We focus on stratospheric dynamics and chemistry relevant to describe the stratospheric ozone layer. The current model version ECHAM4.L39(DLR)/CHEM can realistically reproduce stratospheric dynamics in the Arctic vortex region, including stratospheric warming events. This constitutes a major improvement compared to formerly applied model versions. However, apparent shortcomings in Antarctic circulation and temperatures persist. The seasonal and interannual variability of the ozone layer is simulated in accordance with observations. Activation and deactivation of chlorine in the polar stratospheric vortices and their interhemispheric differences are reproduced. The consideration of the chemistry feedback on dynamics results in an improved representation of the spatial distribution of stratospheric water vapor concentrations, i.e., the simulated meriodional water vapor gradient in the stratosphere is realistic. The present model version constitutes a powerful tool to investigate, for instance, the combined direct and indirect effects of anthropogenic trace gas emissions, and the future evolution of the ozone layer. (orig.)

  14. The Multipole Plasma Trap-PIC Modeling Results

    Science.gov (United States)

    Hicks, Nathaniel; Bowman, Amanda; Godden, Katarina

    2017-10-01

    A radio-frequency (RF) multipole structure is studied via particle-in-cell computer modeling, to assess the response of quasi-neutral plasma to the imposed RF fields. Several regimes, such as pair plasma, antimatter plasma, and conventional (ion-electron) plasma are considered. In the case of equal charge-to-mass ratio of plasma species, the effects of the multipole field are symmetric between positive and negative particles. In the case of a charge-to-mass disparity, the multipole RF parameters (frequency, voltage, structure size) may be chosen such that the light species (e.g. electrons) is strongly confined, while the heavy species (e.g. positive ions) does not respond to the RF field. In this case, the trapped negative space charge creates a potential well that then traps the positive species. 2D and 3D particle-in-cell simulations of this concept are presented, to assess plasma response and trapping dependences on multipole order, consequences of the formation of an RF plasma sheath, and the effects of an axial magnetic field. The scalings of trapped plasma parameters are explored in each of the mentioned regimes, to guide the design of prospective experiments investigating each. Supported by U.S. NSF/DOE Partnership in Basic Plasma Science and Engineering Grant PHY-1619615.

  15. Modeling Framework and Results to Inform Charging Infrastructure Investments

    Energy Technology Data Exchange (ETDEWEB)

    Melaina, Marc W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wood, Eric W [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-01

    The plug-in electric vehicle (PEV) market is experiencing rapid growth with dozens of battery electric (BEV) and plug-in hybrid electric (PHEV) models already available and billions of dollars being invested by automotive manufacturers in the PEV space. Electric range is increasing thanks to larger and more advanced batteries and significant infrastructure investments are being made to enable higher power fast charging. Costs are falling and PEVs are becoming more competitive with conventional vehicles. Moreover, new technologies such as connectivity and automation hold the promise of enhancing the value proposition of PEVs. This presentation outlines a suite of projects funded by the U.S. Department of Energy's Vehicle Technology Office to conduct assessments of the economic value and charging infrastructure requirements of the evolving PEV market. Individual assessments include national evaluations of PEV economic value (assuming 73M PEVs on the road in 2035), national analysis of charging infrastructure requirements (with community and corridor level resolution), and case studies of PEV ownership in Columbus, OH and Massachusetts.

  16. NTCP modelling of lung toxicity after SBRT comparing the universal survival curve and the linear quadratic model for fractionation correction

    International Nuclear Information System (INIS)

    Wennberg, Berit M.; Baumann, Pia; Gagliardi, Giovanna

    2011-01-01

    Background. In SBRT of lung tumours no established relationship between dose-volume parameters and the incidence of lung toxicity is found. The aim of this study is to compare the LQ model and the universal survival curve (USC) to calculate biologically equivalent doses in SBRT to see if this will improve knowledge on this relationship. Material and methods. Toxicity data on radiation pneumonitis grade 2 or more (RP2+) from 57 patients were used, 10.5% were diagnosed with RP2+. The lung DVHs were corrected for fractionation (LQ and USC) and analysed with the Lyman- Kutcher-Burman (LKB) model. In the LQ-correction α/β = 3 Gy was used and the USC parameters used were: α/β = 3 Gy, D 0 = 1.0 Gy, n = 10, α 0.206 Gy-1 and d T = 5.8 Gy. In order to understand the relative contribution of different dose levels to the calculated NTCP the concept of fractional NTCP was used. This might give an insight to the questions of whether 'high doses to small volumes' or 'low doses to large volumes' are most important for lung toxicity. Results and Discussion. NTCP analysis with the LKB-model using parameters m = 0.4, D50 = 30 Gy resulted for the volume dependence parameter (n) with LQ correction n = 0.87 and with USC correction n = 0.71. Using parameters m = 0.3, D 50 = 20 Gy n = 0.93 with LQ correction and n 0.83 with USC correction. In SBRT of lung tumours, NTCP modelling of lung toxicity comparing models (LQ,USC) for fractionation correction, shows that low dose contribute less and high dose more to the NTCP when using the USC-model. Comparing NTCP modelling of SBRT data and data from breast cancer, lung cancer and whole lung irradiation implies that the response of the lung is treatment specific. More data are however needed in order to have a more reliable modelling

  17. A Comparative study of two RVE modelling methods for chopped carbon fiber SMC

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhangxing; Li, Yi; Shao, Yimin; Huang, Tianyu; Xu, Hongyi; Li, Yang; Chen, Wei; Zeng, Danielle; Avery, Katherine; Kang, HongTae; Su, Xuming

    2017-04-06

    To achieve vehicle light-weighting, the chopped carbon fiber sheet molding compound (SMC) is identified as a promising material to replace metals. However, there are no effective tools and methods to predict the mechanical property of the chopped carbon fiber SMC due to the high complexity in microstructure features and the anisotropic properties. In this paper, the Representative Volume Element (RVE) approach is used to model the SMC microstructure. Two modeling methods, the Voronoi diagram-based method and the chip packing method, are developed for material RVE property prediction. The two methods are compared in terms of the predicted elastic modulus and the predicted results are validated using the Digital Image Correlation (DIC) tensile test results. Furthermore, the advantages and shortcomings of these two methods are discussed in terms of the required input information and the convenience of use in the integrated processing-microstructure-property analysis.

  18. Modeling and comparative study of various detection techniques for FMCW LIDAR using optisystem

    Science.gov (United States)

    Elghandour, Ahmed H.; Ren, Chen D.

    2013-09-01

    In this paper we investigated the different detection techniques especially direct detection, coherent heterodyne detection and coherent homodyne detection on FMCW LIDAR system using Optisystem package. A model for target, propagation channel and various detection techniques were developed using Optisystem package and then a comparative study among various detection techniques for FMCW LIDAR systems is done analytically and simulated using the developed model. Performance of direct detection, heterodyne detection and homodyne detection for FMCW LIDAR system was calculated and simulated using Optisystem package. The output simulated performance was checked using simulated results of MATLAB simulator. The results shows that direct detection is sensitive to the intensity of the received electromagnetic signal and has low complexity system advantage over the others detection architectures at the expense of the thermal noise is the dominant noise source and the sensitivity is relatively poor. In addition to much higher detection sensitivity can be achieved using coherent optical mixing which is performed by heterodyne and homodyne detection.

  19. Comparative analysis of mathematical models of the ship from the standpoint of controllability of the variances

    Directory of Open Access Journals (Sweden)

    Pashentsev S. V.

    2017-12-01

    Full Text Available The paper has shown the choice of the mathematical model of the ship with the help of which in the future will be investigated the process of control of the vessel from deviations of two spaced points of the ship's diametric plane from certain lines called aiming. Two mathematical models of the tanker differing structurally are considered: by type and set of differential equations for their description, which are identified parametrically, i. e. the coefficients describing the model equations have been found. To assess the adequacy of the models, their work on the example of the standard maneuver "Zigzag" with the comparative analysis of results between the data and full-scale tests has been tested. The type of maneuver has been chosen on the basis of proximity of the ship characteristic movements to those that occur when the vessel is steered by deviation. Further research has been carried out by performing the managing for deviations in relation to the set of aiming lines. The control quality indicator of quadratic form which assesses the management effectiveness of each model has been introduced. In this calculation case, a mathematical model of the "speed – drift angle – angular speed of rotation" type presented by Japanese engineers has been proposed for the study of complex controls of the tanker of Project 214 on deviations. The model has given estimates of the quality of controls going to "stock". This will allow in further works on the subject on the basis of this mathematical model to obtain results and make the decisions that lead to fewer managerial risks.

  20. Comparative Study on a Solving Model and Algorithm for a Flush Air Data Sensing System

    Directory of Open Access Journals (Sweden)

    Yanbin Liu

    2014-05-01

    Full Text Available With the development of high-performance aircraft, precise air data are necessary to complete challenging tasks such as flight maneuvering with large angles of attack and high speed. As a result, the flush air data sensing system (FADS was developed to satisfy the stricter control demands. In this paper, comparative stuides on the solving model and algorithm for FADS are conducted. First, the basic principles of FADS are given to elucidate the nonlinear relations between the inputs and the outputs. Then, several different solving models and algorithms of FADS are provided to compute the air data, including the angle of attck, sideslip angle, dynamic pressure and static pressure. Afterwards, the evaluation criteria of the resulting models and algorithms are discussed to satisfy the real design demands. Futhermore, a simulation using these algorithms is performed to identify the properites of the distinct models and algorithms such as the measuring precision and real-time features. The advantages of these models and algorithms corresponding to the different flight conditions are also analyzed, furthermore, some suggestions on their engineering applications are proposed to help future research.

  1. Task decomposition: a framework for comparing diverse training models in human brain plasticity studies

    Directory of Open Access Journals (Sweden)

    Emily B. J. Coffey

    2013-10-01

    Full Text Available Training studies, in which the structural or functional neurophysiology is compared before and after expertise is acquired, are increasingly being used as models for understanding the human brain’s potential for reorganization. It is proving difficult to use these results to answer basic and important questions like how task training leads to both specific and general changes in behaviour and how these changes correspond with modifications in the brain. The main culprit is the diversity of paradigms used as complex task models. An assortment of activities ranging from juggling to deciphering Morse code has been reported. Even when working in the same general domain, few researchers use similar training models. New ways to meaningfully compare complex tasks are needed. We propose a method for characterizing and deconstructing the task requirements of complex training paradigms, which is suitable for application to both structural and functional neuroimaging studies. We believe this approach will aid brain plasticity research by making it easier to compare training paradigms, identify ‘missing puzzle pieces’, and encourage researchers to design training protocols to bridge these gaps.

  2. THE EFFECTS OF COOPERATIVE LEARNING MODEL GROUP INVESTIGATION AND MOTIVATION TOWARD PHYSICS LEARNING RESULTS MAN TANJUNGBALAI

    Directory of Open Access Journals (Sweden)

    Amalia Febri Aristi

    2014-12-01

    Full Text Available This study aimed to determine: (1 Is there a difference in student's learning outcomes with the application of learning models Investigation Group and Direct Instruction teaching model. (2 Is there a difference in students' motivation with the application of learning models Investigation Group and Direct Instruction teaching model, (3 Is there an interaction between learning models Investigation Group and Direct Instruction to improve students' motivation in learning outcomes Physics. This research is a quasi experimental. The study population was a student of class XII Tanjung Balai MAN. Random sample selection is done by randomizing the class. The instrument used consisted of: (1 achievement test (2 students' motivation questionnaire. The tests are used to obtain the data is shaped essay. The data in this study were analyzed using ANOVA analysis of two paths. The results showed that: (1 there were differences in learning outcomes between students who used the physics model of Group Investigation learning compared with students who used the Direct Instruction teaching model. (2 There was a difference in student's learning outcomes that had a low learning motivation and high motivation to learn both in the classroom and in the classroom Investigation Group Direct Instruction. (3 There was interaction between learning models Instruction Direct Group Investigation and motivation to learn in improving learning outcomes Physics.

  3. Butter increased total and LDL cholesterol compared with olive oil but resulted in higher HDL cholesterol compared with a habitual diet.

    Science.gov (United States)

    Engel, Sara; Tholstrup, Tine

    2015-08-01

    Butter is known to have a cholesterol-raising effect and, therefore, has often been included as a negative control in dietary studies, whereas the effect of moderate butter intake has not been elucidated to our knowledge. We compared the effects of moderate butter intake, moderate olive oil intake, and a habitual diet on blood lipids, high-sensitivity C-reactive protein (hsCRP), glucose, and insulin. The study was a controlled, double-blinded, randomized 2 × 5-wk crossover dietary intervention study with a 14-d run-in period during which subjects consumed their habitual diets. The study included 47 healthy men and women (mean ± SD total cholesterol: 5.22 ± 0.90 mmol/L) who substituted a part of their habitual diets with 4.5% of energy from butter or refined olive oil. Study subjects were 70% women with a mean age and body mass index (in kg/m²) of 40.4 y and 23.5, respectively. Butter intake increased total cholesterol and LDL cholesterol more than did olive oil intake (P butter period than in the olive oil and run-in periods (P butter resulted in increases in total cholesterol and LDL cholesterol compared with the effects of olive oil intake and a habitual diet (run-in period). Furthermore, moderate butter intake was also followed by an increase in HDL cholesterol compared with the habitual diet. We conclude that hypercholesterolemic people should keep their consumption of butter to a minimum, whereas moderate butter intake may be considered part of the diet in the normocholesterolemic population. © 2015 American Society for Nutrition.

  4. Quantifying Uncertainty in Model Predictions for the Pliocene (Plio-QUMP): Initial results

    Science.gov (United States)

    Pope, J.O.; Collins, M.; Haywood, A.M.; Dowsett, H.J.; Hunter, S.J.; Lunt, D.J.; Pickering, S.J.; Pound, M.J.

    2011-01-01

    Examination of the mid-Pliocene Warm Period (mPWP; ~. 3.3 to 3.0. Ma BP) provides an excellent opportunity to test the ability of climate models to reproduce warm climate states, thereby assessing our confidence in model predictions. To do this it is necessary to relate the uncertainty in model simulations of mPWP climate to uncertainties in projections of future climate change. The uncertainties introduced by the model can be estimated through the use of a Perturbed Physics Ensemble (PPE). Developing on the UK Met Office Quantifying Uncertainty in Model Predictions (QUMP) Project, this paper presents the results from an initial investigation using the end members of a PPE in a fully coupled atmosphere-ocean model (HadCM3) running with appropriate mPWP boundary conditions. Prior work has shown that the unperturbed version of HadCM3 may underestimate mPWP sea surface temperatures at higher latitudes. Initial results indicate that neither the low sensitivity nor the high sensitivity simulations produce unequivocally improved mPWP climatology relative to the standard. Whilst the high sensitivity simulation was able to reconcile up to 6 ??C of the data/model mismatch in sea surface temperatures in the high latitudes of the Northern Hemisphere (relative to the standard simulation), it did not produce a better prediction of global vegetation than the standard simulation. Overall the low sensitivity simulation was degraded compared to the standard and high sensitivity simulations in all aspects of the data/model comparison. The results have shown that a PPE has the potential to explore weaknesses in mPWP modelling simulations which have been identified by geological proxies, but that a 'best fit' simulation will more likely come from a full ensemble in which simulations that contain the strengths of the two end member simulations shown here are combined. ?? 2011 Elsevier B.V.

  5. Modeling Nonlinear Power Amplifiers in OFDM Systems from Subsampled Data: A Comparative Study Using Real Measurements

    Directory of Open Access Journals (Sweden)

    Santamaría Ignacio

    2003-01-01

    Full Text Available A comparative study among several nonlinear high-power amplifier (HPA models using real measurements is carried out. The analysis is focused on specific models for wideband OFDM signals, which are known to be very sensitive to nonlinear distortion. Moreover, unlike conventional techniques, which typically use a single-tone test signal and power measurements, in this study the models are fitted using subsampled time-domain data. The in-band and out-of-band (spectral regrowth performances of the following models are evaluated and compared: Saleh's model, envelope polynomial model (EPM, Volterra model, the multilayer perceptron (MLP model, and the smoothed piecewise-linear (SPWL model. The study shows that the SPWL model provides the best in-band characterization of the HPA. On the other hand, the Volterra model provides a good trade-off between model complexity (number of parameters and performance.

  6. Comparing supply and demand models for future photovoltaic power generation in the USA

    Energy Technology Data Exchange (ETDEWEB)

    Basore, Paul A. [US Department of Energy, Washington DC 20585 USA; Cole, Wesley J. [National Renewable Energy Laboratory, Golden CO 80401 USA

    2018-02-22

    We explore the plausible range of future deployment of photovoltaic generation capacity in the USA using a supply-focused model based on supply-chain growth constraints and a demand-focused model based on minimizing the overall cost of the electricity system. Both approaches require assumptions based on previous experience and anticipated trends. For each of the models, we assign plausible ranges for the key assumptions and then compare the resulting PV deployment over time. Each model was applied to 2 different future scenarios: one in which PV market penetration is ultimately constrained by the uncontrolled variability of solar power and one in which low-cost energy storage or some equivalent measure largely alleviates this constraint. The supply-focused and demand-focused models are in substantial agreement, not just in the long term, where deployment is largely determined by the assumed market penetration constraints, but also in the interim years. For the future scenario without low-cost energy storage or equivalent measures, the 2 models give an average plausible range of PV generation capacity in the USA of 150 to 530 GWdc in 2030 and 260 to 810 GWdc in 2040. With low-cost energy storage or equivalent measures, the corresponding ranges are 160 to 630 GWdc in 2030 and 280 to 1200 GWdc in 2040. The latter range is enough to supply 10% to 40% of US electricity demand in 2040, based on current demand growth.

  7. Stirling cryocooler test results and design model verification

    International Nuclear Information System (INIS)

    Shimko, M.A.; Stacy, W.D.; McCormick, J.A.

    1990-01-01

    This paper reports on progress in developing a long-life Stirling cycle cryocooler for space borne applications. It presents the results from tests on a preliminary breadboard version of the cryocooler used to demonstrate the feasibility of the technology and to validate the regenerator design code used in its development. This machine achieved a cold-end temperature of 65 K while carrying a 1/2 Watt cooling load. The basic machine is a double-acting, flexure-bearing, split Stirling design with linear electromagnetic drives for the expander and compressors. Flat metal diaphragms replace pistons for both sweeping and sealing the machine working volumes. In addition, the double-acting expander couples to a laminar-channel counterflow recuperative heat exchanger for regeneration. A PC compatible design code was developed for this design approach that calculates regenerator loss including heat transfer irreversibilities, pressure drop, and axial conduction in the regenerator walls

  8. Stress Resultant Based Elasto-Viscoplastic Thick Shell Model

    Directory of Open Access Journals (Sweden)

    Pawel Woelke

    2012-01-01

    Full Text Available The current paper presents enhancement introduced to the elasto-viscoplastic shell formulation, which serves as a theoretical base for the finite element code EPSA (Elasto-Plastic Shell Analysis [1–3]. The shell equations used in EPSA are modified to account for transverse shear deformation, which is important in the analysis of thick plates and shells, as well as composite laminates. Transverse shear forces calculated from transverse shear strains are introduced into a rate-dependent yield function, which is similar to Iliushin's yield surface expressed in terms of stress resultants and stress couples [12]. The hardening rule defined by Bieniek and Funaro [4], which allows for representation of the Bauschinger effect on a moment-curvature plane, was previously adopted in EPSA and is used here in the same form. Viscoplastic strain rates are calculated, taking into account the transverse shears. Only non-layered shells are considered in this work.

  9. Intensity-Modulated Radiotherapy Results in Significant Decrease in Clinical Toxicities Compared With Conventional Wedge-Based Breast Radiotherapy

    International Nuclear Information System (INIS)

    Harsolia, Asif; Kestin, Larry; Grills, Inga; Wallace, Michelle; Jolly, Shruti; Jones, Cortney; Lala, Moinaktar; Martinez, Alvaro; Schell, Scott; Vicini, Frank A.

    2007-01-01

    Purpose: We have previously demonstrated that intensity-modulated radiotherapy (IMRT) with a static multileaf collimator process results in a more homogenous dose distribution compared with conventional wedge-based whole breast irradiation (WBI). In the present analysis, we reviewed the acute and chronic toxicity of this IMRT approach compared with conventional wedge-based treatment. Methods and Materials: A total of 172 patients with Stage 0-IIB breast cancer were treated with lumpectomy followed by WBI. All patients underwent treatment planning computed tomography and received WBI (median dose, 45 Gy) followed by a boost to 61 Gy. Of the 172 patients, 93 (54%) were treated with IMRT, and the 79 patients (46%) treated with wedge-based RT in a consecutive fashion immediately before this cohort served as the control group. The median follow-up was 4.7 years. Results: A significant reduction in acute Grade 2 or worse dermatitis, edema, and hyperpigmentation was seen with IMRT compared with wedges. A trend was found toward reduced acute Grade 3 or greater dermatitis (6% vs. 1%, p = 0.09) in favor of IMRT. Chronic Grade 2 or worse breast edema was significantly reduced with IMRT compared with conventional wedges. No difference was found in cosmesis scores between the two groups. In patients with larger breasts (≥1,600 cm 3 , n = 64), IMRT resulted in reduced acute (Grade 2 or greater) breast edema (0% vs. 36%, p <0.001) and hyperpigmentation (3% vs. 41%, p 0.001) and chronic (Grade 2 or greater) long-term edema (3% vs. 30%, p 0.007). Conclusion: The use of IMRT in the treatment of the whole breast results in a significant decrease in acute dermatitis, edema, and hyperpigmentation and a reduction in the development of chronic breast edema compared with conventional wedge-based RT

  10. State regulation of nuclear sector: comparative study of Argentina and Brazil models

    International Nuclear Information System (INIS)

    Monteiro Filho, Joselio Silveira

    2004-08-01

    This research presents a comparative assessment of the regulation models of the nuclear sector in Argentina - under the responsibility of the Autoridad Regulatoria Nuclear (ARN), and Brazil - under the responsibility of Comissao Nacional de Energia Nuclear (CNEN), trying to identify which model is more adequate aiming the safe use of nuclear energy. Due to the methodology adopted, the theoretical framework resulted in criteria of analysis that corresponds to the characteristics of the Brazilian regulatory agencies created for other economic sector during the State reform staring in the middle of the nineties. Later, these criteria of analysis were used as comparison patterns between the regulation models of the nuclear sectors of Argentina and Brazil. The comparative assessment showed that the regulatory structure of the nuclear sector in Argentina seems to be more adequate, concerning the safe use of nuclear energy, than the model adopted in Brazil by CNEN, because its incorporates the criteria of functional, institutional and financial independence, competence definitions, technical excellence and transparency, indispensable to the development of its functions with autonomy, ethics, exemption and agility. (author)

  11. Comparison of Experimental Surface and Flow Field Measurements to Computational Results of the Juncture Flow Model

    Science.gov (United States)

    Roozeboom, Nettie H.; Lee, Henry C.; Simurda, Laura J.; Zilliac, Gregory G.; Pulliam, Thomas H.

    2016-01-01

    Wing-body juncture flow fields on commercial aircraft configurations are challenging to compute accurately. The NASA Advanced Air Vehicle Program's juncture flow committee is designing an experiment to provide data to improve Computational Fluid Dynamics (CFD) modeling in the juncture flow region. Preliminary design of the model was done using CFD, yet CFD tends to over-predict the separation in the juncture flow region. Risk reduction wind tunnel tests were requisitioned by the committee to obtain a better understanding of the flow characteristics of the designed models. NASA Ames Research Center's Fluid Mechanics Lab performed one of the risk reduction tests. The results of one case, accompanied by CFD simulations, are presented in this paper. Experimental results suggest the wall mounted wind tunnel model produces a thicker boundary layer on the fuselage than the CFD predictions, resulting in a larger wing horseshoe vortex suppressing the side of body separation in the juncture flow region. Compared to experimental results, CFD predicts a thinner boundary layer on the fuselage generates a weaker wing horseshoe vortex resulting in a larger side of body separation.

  12. Error statistics of hidden Markov model and hidden Boltzmann model results

    Directory of Open Access Journals (Sweden)

    Newberg Lee A

    2009-07-01

    Full Text Available Abstract Background Hidden Markov models and hidden Boltzmann models are employed in computational biology and a variety of other scientific fields for a variety of analyses of sequential data. Whether the associated algorithms are used to compute an actual probability or, more generally, an odds ratio or some other score, a frequent requirement is that the error statistics of a given score be known. What is the chance that random data would achieve that score or better? What is the chance that a real signal would achieve a given score threshold? Results Here we present a novel general approach to estimating these false positive and true positive rates that is significantly more efficient than are existing general approaches. We validate the technique via an implementation within the HMMER 3.0 package, which scans DNA or protein sequence databases for patterns of interest, using a profile-HMM. Conclusion The new approach is faster than general naïve sampling approaches, and more general than other current approaches. It provides an efficient mechanism by which to estimate error statistics for hidden Markov model and hidden Boltzmann model results.

  13. A Comparative Structural Equation Modeling Investigation of the Relationships among Teaching, Cognitive and Social Presence

    Science.gov (United States)

    Kozan, Kadir

    2016-01-01

    The present study investigated the relationships among teaching, cognitive, and social presence through several structural equation models to see which model would better fit the data. To this end, the present study employed and compared several different structural equation models because different models could fit the data equally well. Among…

  14. Modeling results for a linear simulator of a divertor

    Energy Technology Data Exchange (ETDEWEB)

    Hooper, E.B.; Brown, M.D.; Byers, J.A.; Casper, T.A.; Cohen, B.I.; Cohen, R.H.; Jackson, M.C.; Kaiser, T.B.; Molvik, A.W.; Nevins, W.M.; Nilson, D.G.; Pearlstein, L.D.; Rognlien, T.D.

    1993-06-23

    A divertor simulator, IDEAL, has been proposed by S. Cohen to study the difficult power-handling requirements of the tokamak program in general and the ITER program in particular. Projections of the power density in the ITER divertor reach {approximately} 1 Gw/m{sup 2} along the magnetic fieldlines and > 10 MW/m{sup 2} on a surface inclined at a shallow angle to the fieldlines. These power densities are substantially greater than can be handled reliably on the surface, so new techniques are required to reduce the power density to a reasonable level. Although the divertor physics must be demonstrated in tokamaks, a linear device could contribute to the development because of its flexibility, the easy access to the plasma and to tested components, and long pulse operation (essentially cw). However, a decision to build a simulator requires not just the recognition of its programmatic value, but also confidence that it can meet the required parameters at an affordable cost. Accordingly, as reported here, it was decided to examine the physics of the proposed device, including kinetic effects resulting from the intense heating required to reach the plasma parameters, and to conduct an independent cost estimate. The detailed role of the simulator in a divertor program is not explored in this report.

  15. Modeling results for a linear simulator of a divertor

    International Nuclear Information System (INIS)

    Hooper, E.B.; Brown, M.D.; Byers, J.A.; Casper, T.A.; Cohen, B.I.; Cohen, R.H.; Jackson, M.C.; Kaiser, T.B.; Molvik, A.W.; Nevins, W.M.; Nilson, D.G.; Pearlstein, L.D.; Rognlien, T.D.

    1993-01-01

    A divertor simulator, IDEAL, has been proposed by S. Cohen to study the difficult power-handling requirements of the tokamak program in general and the ITER program in particular. Projections of the power density in the ITER divertor reach ∼ 1 Gw/m 2 along the magnetic fieldlines and > 10 MW/m 2 on a surface inclined at a shallow angle to the fieldlines. These power densities are substantially greater than can be handled reliably on the surface, so new techniques are required to reduce the power density to a reasonable level. Although the divertor physics must be demonstrated in tokamaks, a linear device could contribute to the development because of its flexibility, the easy access to the plasma and to tested components, and long pulse operation (essentially cw). However, a decision to build a simulator requires not just the recognition of its programmatic value, but also confidence that it can meet the required parameters at an affordable cost. Accordingly, as reported here, it was decided to examine the physics of the proposed device, including kinetic effects resulting from the intense heating required to reach the plasma parameters, and to conduct an independent cost estimate. The detailed role of the simulator in a divertor program is not explored in this report

  16. Comparing Apples to Apples: Paleoclimate Model-Data comparison via Proxy System Modeling

    Science.gov (United States)

    Dee, Sylvia; Emile-Geay, Julien; Evans, Michael; Noone, David

    2014-05-01

    The wealth of paleodata spanning the last millennium (hereinafter LM) provides an invaluable testbed for CMIP5-class GCMs. However, comparing GCM output to paleodata is non-trivial. High-resolution paleoclimate proxies generally contain a multivariate and non-linear response to regional climate forcing. Disentangling the multivariate environmental influences on proxies like corals, speleothems, and trees can be complex due to spatiotemporal climate variability, non-stationarity, and threshold dependence. Given these and other complications, many paleodata-GCM comparisons take a leap of faith, relating climate fields (e.g. precipitation, temperature) to geochemical signals in proxy data (e.g. δ18O in coral aragonite or ice cores) (e.g. Braconnot et al., 2012). Isotope-enabled GCMs are a step in the right direction, with water isotopes providing a connector point between GCMs and paleodata. However, such studies are still rare, and isotope fields are not archived as part of LM PMIP3 simulations. More importantly, much of the complexity in how proxy systems record and transduce environmental signals remains unaccounted for. In this study we use proxy system models (PSMs, Evans et al., 2013) to bridge this conceptual gap. A PSM mathematically encodes the mechanistic understanding of the physical, geochemical and, sometimes biological influences on each proxy. To translate GCM output to proxy space, we have synthesized a comprehensive, consistently formatted package of published PSMs, including δ18O in corals, tree ring cellulose, speleothems, and ice cores. Each PSM is comprised of three sub-models: sensor, archive, and observation. For the first time, these different components are coupled together for four major proxy types, allowing uncertainties due to both dating and signal interpretation to be treated within a self-consistent framework. The output of this process is an ensemble of many (say N = 1,000) realizations of the proxy network, all equally plausible

  17. Results of an interactively coupled atmospheric chemistry – general circulation model: Comparison with observations

    Directory of Open Access Journals (Sweden)

    R. Hein

    2001-04-01

    Full Text Available The coupled climate-chemistry model ECHAM4.L39(DLR/CHEM is presented which enables a simultaneous treatment of meteorology and atmospheric chemistry and their feedbacks. This is the first model which interactively combines a general circulation model with a chemical model, employing most of the important reactions and species necessary to describe the stratospheric and upper tropospheric ozone chemistry, and which is computationally fast enough to allow long-term integrations with currently available computer resources. This is possible as the model time-step used for the chemistry can be chosen as large as the integration time-step for the dynamics. Vertically the atmosphere is discretized by 39 levels from the surface up to the top layer which is centred at 10 hPa, with a relatively high vertical resolution of approximately 700 m near the extra-tropical tropopause. We present the results of a control simulation representing recent conditions (1990 and compare it to available observations. The focus is on investigations of stratospheric dynamics and chemistry relevant to describe the stratospheric ozone layer. ECHAM4.L39(DLR/CHEM reproduces main features of stratospheric dynamics in the arctic vortex region, including stratospheric warming events. This constitutes a major improvement compared to earlier model versions. However, apparent shortcomings in Antarctic circulation and temperatures persist. The seasonal and interannual variability of the ozone layer is simulated in accordance with observations. Activation and deactivation of chlorine in the polar stratospheric vortices and their inter-hemispheric differences are reproduced. Considering methane oxidation as part of the dynamic-chemistry feedback results in an improved representation of the spatial distribution of stratospheric water vapour concentrations. The current model constitutes a powerful tool to investigate, for instance, the combined direct and indirect effects of anthropogenic

  18. Results of an interactively coupled atmospheric chemistry – general circulation model: Comparison with observations

    Directory of Open Access Journals (Sweden)

    R. Hein

    Full Text Available The coupled climate-chemistry model ECHAM4.L39(DLR/CHEM is presented which enables a simultaneous treatment of meteorology and atmospheric chemistry and their feedbacks. This is the first model which interactively combines a general circulation model with a chemical model, employing most of the important reactions and species necessary to describe the stratospheric and upper tropospheric ozone chemistry, and which is computationally fast enough to allow long-term integrations with currently available computer resources. This is possible as the model time-step used for the chemistry can be chosen as large as the integration time-step for the dynamics. Vertically the atmosphere is discretized by 39 levels from the surface up to the top layer which is centred at 10 hPa, with a relatively high vertical resolution of approximately 700 m near the extra-tropical tropopause. We present the results of a control simulation representing recent conditions (1990 and compare it to available observations. The focus is on investigations of stratospheric dynamics and chemistry relevant to describe the stratospheric ozone layer. ECHAM4.L39(DLR/CHEM reproduces main features of stratospheric dynamics in the arctic vortex region, including stratospheric warming events. This constitutes a major improvement compared to earlier model versions. However, apparent shortcomings in Antarctic circulation and temperatures persist. The seasonal and interannual variability of the ozone layer is simulated in accordance with observations. Activation and deactivation of chlorine in the polar stratospheric vortices and their inter-hemispheric differences are reproduced. Considering methane oxidation as part of the dynamic-chemistry feedback results in an improved representation of the spatial distribution of stratospheric water vapour concentrations. The current model constitutes a powerful tool to investigate, for instance, the combined direct and indirect effects of anthropogenic

  19. Can different primary care databases produce comparable estimates of burden of disease: results of a study exploring venous leg ulceration.

    Science.gov (United States)

    Petherick, Emily S; Pickett, Kate E; Cullum, Nicky A

    2015-08-01

    Primary care databases from the UK have been widely used to produce evidence on the epidemiology and health service usage of a wide range of conditions. To date there have been few evaluations of the comparability of estimates between different sources of these data. To estimate the comparability of two widely used primary care databases, the Health Improvement Network Database (THIN) and the General Practice Research Database (GPRD) using venous leg ulceration as an exemplar condition. Cross prospective cohort comparison. GPRD and the THIN databases using data from 1998 to 2006. A data set was extracted from both databases containing all cases of persons aged 20 years or greater with a database diagnosis of venous leg ulceration recorded in the databases for the period 1998-2006. Annual rates of incidence and prevalence of venous leg ulceration were calculated within each database and standardized to the European standard population and compared using standardized rate ratios. Comparable estimates of venous leg ulcer incidence from the GPRD and THIN databases could be obtained using data from 2000 to 2006 and of prevalence using data from 2001 to 2006. Recent data collected by these two databases are more likely to produce comparable results of the burden venous leg ulceration. These results require confirmation in other disease areas to enable researchers to have confidence in the comparability of findings from these two widely used primary care research resources. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Comparing Cognitive Models of Domain Mastery and Task Performance in Algebra: Validity Evidence for a State Assessment

    Science.gov (United States)

    Warner, Zachary B.

    2013-01-01

    This study compared an expert-based cognitive model of domain mastery with student-based cognitive models of task performance for Integrated Algebra. Interpretations of student test results are limited by experts' hypotheses of how students interact with the items. In reality, the cognitive processes that students use to solve each item may be…

  1. Compare Energy Use in Variable Refrigerant Flow Heat Pumps Field Demonstration and Computer Model

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Chandan; Raustad, Richard

    2013-07-01

    Variable Refrigerant Flow (VRF) heat pumps are often regarded as energy efficient air-conditioning systems which offer electricity savings as well as reduction in peak electric demand while providing improved individual zone setpoint control. One of the key advantages of VRF systems is minimal duct losses which provide significant reduction in energy use and duct space. However, there is limited data available to show their actual performance in the field. Since VRF systems are increasingly gaining market share in the US, it is highly desirable to have more actual field performance data of these systems. An effort was made in this direction to monitor VRF system performance over an extended period of time in a US national lab test facility. Due to increasing demand by the energy modeling community, an empirical model to simulate VRF systems was implemented in the building simulation program EnergyPlus. This paper presents the comparison of energy consumption as measured in the national lab and as predicted by the program. For increased accuracy in the comparison, a customized weather file was created by using measured outdoor temperature and relative humidity at the test facility. Other inputs to the model included building construction, VRF system model based on lab measured performance, occupancy of the building, lighting/plug loads, and thermostat set-points etc. Infiltration model inputs were adjusted in the beginning to tune the computer model and then subsequent field measurements were compared to the simulation results. Differences between the computer model results and actual field measurements are discussed. The computer generated VRF performance closely resembled the field measurements.

  2. Comparative analysis of elements and models of implementation in local-level spatial plans in Serbia

    Directory of Open Access Journals (Sweden)

    Stefanović Nebojša

    2017-01-01

    Full Text Available Implementation of local-level spatial plans is of paramount importance to the development of the local community. This paper aims to demonstrate the importance of and offer further directions for research into the implementation of spatial plans by presenting the results of a study on models of implementation. The paper describes the basic theoretical postulates of a model for implementing spatial plans. A comparative analysis of the application of elements and models of implementation of plans in practice was conducted based on the spatial plans for the local municipalities of Arilje, Lazarevac and Sremska Mitrovica. The analysis includes four models of implementation: the strategy and policy of spatial development; spatial protection; the implementation of planning solutions of a technical nature; and the implementation of rules of use, arrangement and construction of spaces. The main results of the analysis are presented and used to give recommendations for improving the elements and models of implementation. Final deliberations show that models of implementation are generally used in practice and combined in spatial plans. Based on the analysis of how models of implementation are applied in practice, a general conclusion concerning the complex character of the local level of planning is presented and elaborated. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 36035: Spatial, Environmental, Energy and Social Aspects of Developing Settlements and Climate Change - Mutual Impacts and Grant no. III 47014: The Role and Implementation of the National Spatial Plan and Regional Development Documents in Renewal of Strategic Research, Thinking and Governance in Serbia

  3. Dynamic simulation of friction-induced vibrations in a light railway bogie while curving compared with measurement results

    Science.gov (United States)

    Kurzeck, Bernhard; Hecht, Markus

    2010-12-01

    It is a frequently observed phenomenon that curving of railway vehicles can involve friction-induced oscillations. The study presented in this paper investigates vibrations with a frequency of 80 Hz occurring at a light rail vehicle in Stuttgart in curves with radii between 50 and 200 m. The aim of the investigation was to identify the oscillation and transmission mechanism, and the dominant parameters within this. As the cause could not be clearly identified from the measurements, a multi-body simulation in the time domain was used. The model consisted of both vehicle and track and considered the structural dynamics of the wheelset and bogie frame up to 200 Hz. The system was modelled using the commercial MBS software SIMPACK. The identified model describes the oscillations observed at the real vehicle. The results proved to be useful in minimising the vibrations at the real vehicles.

  4. Comparing wall modeled LES and prescribed boundary layer approach in infinite wind farm simulations

    DEFF Research Database (Denmark)

    Sarlak, Hamid; Mikkelsen, Robert; Sørensen, Jens Nørkær

    2015-01-01

    This paper aims at presenting a simple and computationally fast method for simulation of the Atmospheric Boundary Layer (ABL) and comparing the results with the commonly used wall-modelled Large Eddy Simulation (WMLES). The simple method, called Prescribed Mean Shear and Turbulence (PMST) hereafter...... inexpensive, is high flexibility meaning that the imposed boundary layer can be read from another CFD simulation, or from site measurements. For fundamental studies focusing on the wake structures rather than ABL for example, the grid can be refined in the rotor region and any desired shear layer can...

  5. Comparative Analysis of Market Volatility in Indian Banking and IT Sectors by using Average Decline Model

    Directory of Open Access Journals (Sweden)

    Kirti AREKAR

    2017-12-01

    Full Text Available The stock market volatility is depends on three major features, complete volatility, volatility fluctuations, and volatility attention and they are calculate by the statistical techniques. Comparative analysis of market volatility for two major index i.e. banking & IT sector in Bombay stock exchange (BSE by using average decline model. The average degeneration process in volatility has being used after very high and low stock returns. The results of this study explain significant decline in volatility fluctuations, attention, and level between epochs of pre and post particularly high stock returns.

  6. Comparing the effects of community service and imprisonment on reconviction: results from a quasi-experimental Danish study

    DEFF Research Database (Denmark)

    Klement, Christian

    2015-01-01

    Objective This study compares reconviction rates for Danish offenders sentenced to community service and imprisonment. A large general sample of offenders (n = 1602) is examined. Methods The study relies on a quasi-experimental design and uses propensity score matching as well as logistic...... service eligibility assessments and registry databases, provide powerful controls over potential selection mechanisms in the multivariate analyses. Furthermore, contrary to previous studies, the current study limits itself to subjects officially assessed and deemed eligible for community service sentences....... Results Imprisonment is associated with a higher rate of recidivism and the result is statistically significant at conventional statistical levels. Conclusions Community service (CS) compared to imprisonment appears to cause a lower reconviction rate in general. Additional research is needed to shed light...

  7. Comparing thixotropic and Herschel–Bulkley parameterizations for continuum models of avalanches and subaqueous debris flows

    Directory of Open Access Journals (Sweden)

    C.-H. Jeon

    2018-01-01

    Full Text Available Avalanches and subaqueous debris flows are two cases of a wide range of natural hazards that have been previously modeled with non-Newtonian fluid mechanics approximating the interplay of forces associated with gravity flows of granular and solid–liquid mixtures. The complex behaviors of such flows at unsteady flow initiation (i.e., destruction of structural jamming and flow stalling (restructuralization imply that the representative viscosity–stress relationships should include hysteresis: there is no reason to expect the timescale of microstructure destruction is the same as the timescale of restructuralization. The non-Newtonian Herschel–Bulkley relationship that has been previously used in such models implies complete reversibility of the stress–strain relationship and thus cannot correctly represent unsteady phases. In contrast, a thixotropic non-Newtonian model allows representation of initial structural jamming and aging effects that provide hysteresis in the stress–strain relationship. In this study, a thixotropic model and a Herschel–Bulkley model are compared to each other and to prior laboratory experiments that are representative of an avalanche and a subaqueous debris flow. A numerical solver using a multi-material level-set method is applied to track multiple interfaces simultaneously in the simulations. The numerical results are validated with analytical solutions and available experimental data using parameters selected based on the experimental setup and without post hoc calibration. The thixotropic (time-dependent fluid model shows reasonable agreement with all the experimental data. For most of the experimental conditions, the Herschel–Bulkley (time-independent model results were similar to the thixotropic model, a critical exception being conditions with a high yield stress where the Herschel–Bulkley model did not initiate flow. These results indicate that the thixotropic relationship is promising for

  8. Comparing the Goodness of Different Statistical Criteria for Evaluating the Soil Water Infiltration Models

    Directory of Open Access Journals (Sweden)

    S. Mirzaee

    2016-02-01

    Full Text Available Introduction: The infiltration process is one of the most important components of the hydrologic cycle. Quantifying the infiltration water into soil is of great importance in watershed management. Prediction of flooding, erosion and pollutant transport all depends on the rate of runoff which is directly affected by the rate of infiltration. Quantification of infiltration water into soil is also necessary to determine the availability of water for crop growth and to estimate the amount of additional water needed for irrigation. Thus, an accurate model is required to estimate infiltration of water into soil. The ability of physical and empirical models in simulation of soil processes is commonly measured through comparisons of simulated and observed values. For these reasons, a large variety of indices have been proposed and used over the years in comparison of infiltration water into soil models. Among the proposed indices, some are absolute criteria such as the widely used root mean square error (RMSE, while others are relative criteria (i.e. normalized such as the Nash and Sutcliffe (1970 efficiency criterion (NSE. Selecting and using appropriate statistical criteria to evaluate and interpretation of the results for infiltration water into soil models is essential because each of the used criteria focus on specific types of errors. Also, descriptions of various goodness of fit indices or indicators including their advantages and shortcomings, and rigorous discussions on the suitability of each index are very important. The objective of this study is to compare the goodness of different statistical criteria to evaluate infiltration of water into soil models. Comparison techniques were considered to define the best models: coefficient of determination (R2, root mean square error (RMSE, efficiency criteria (NSEI and modified forms (such as NSEjI, NSESQRTI, NSElnI and NSEiI. Comparatively little work has been carried out on the meaning and

  9. One-year results of a prospective randomized, evaluator-blinded, multicenter study comparing TVT and TVT Secur.

    OpenAIRE

    Andrada Hamer, Maria; Larsson, Per-Göran; Teleman, Pia; Bergqvist, Christina Eten; Persson, Jan

    2012-01-01

    INTRODUCTION AND HYPOTHESIS: The aim of this prospective randomized multicenter study was to compare retropubic tension-free vaginal tape (TVT) with TVT Secur in terms of efficacy and safety. METHODS: We set out to enrol 280 stress urinary incontinent (SUI) women with a half-time interim analysis of short-term cure and adverse events. The short-term results have previously been published. Of the133 randomized women, 125 underwent surgery, and 121 (TVT n = 61, TVT Secur n = 60)...

  10. Selection of comparative cases in land appraisal based on cloud model and gray relevancy theory

    Science.gov (United States)

    Yang, Liu; Liu, Yanfang; Liu, Wei; Song, Xinying; Xu, Xiongjie

    2008-10-01

    There is a traditional approach named market comparative method, which is used to appraise land price by putting a focus on comparing cases. A review of the developing history of this method highlights some persistent challenges. In this paper, this existing approach is extended through coupling the cloud model, a data-mining technique, with gray relevancy theory. This approach allows the construction of quantitative measurement according to qualitative concept (attribute), simulating human cognizing process. This novel method admits hierarchical describing and exploration of the relationship and proximity between district factors and individual factors. By 1-D cloud generator, we obtain several rules in terms of linguistic atom which confirm the number of overlap cloud. Each rule corresponds to a rule's rear that achieves uncertainty ratiocination. In order to prove applicability of this method, it is applied to the selection of comparative cases in land appraisal of Wuhan City. Experimental results show most cases can be correctly discriminated and the better comparative cases are acceptable. Compared with other approaches, this method has better performance in land appraisal.

  11. Comparing Free-Free and Shaker Table Model Correlation Methods Using Jim Beam

    Science.gov (United States)

    Ristow, James; Smith, Kenneth Wayne, Jr.; Johnson, Nathaniel; Kinney, Jackson

    2018-01-01

    Finite element model correlation as part of a spacecraft program has always been a challenge. For any NASA mission, the coupled system response of the spacecraft and launch vehicle can be determined analytically through a Coupled Loads Analysis (CLA), as it is not possible to test the spacecraft and launch vehicle coupled system before launch. The value of the CLA is highly dependent on the accuracy of the frequencies and mode shapes extracted from the spacecraft model. NASA standards require the spacecraft model used in the final Verification Loads Cycle to be correlated by either a modal test or by comparison of the model with Frequency Response Functions (FRFs) obtained during the environmental qualification test. Due to budgetary and time constraints, most programs opt to correlate the spacecraft dynamic model during the environmental qualification test, conducted on a large shaker table. For any model correlation effort, the key has always been finding a proper definition of the boundary conditions. This paper is a correlation case study to investigate the difference in responses of a simple structure using a free-free boundary, a fixed boundary on the shaker table, and a base-drive vibration test, all using identical instrumentation. The NAVCON Jim Beam test structure, featured in the IMAC round robin modal test of 2009, was selected as a simple, well recognized and well characterized structure to conduct this investigation. First, a free-free impact modal test of the Jim Beam was done as an experimental control. Second, the Jim Beam was mounted to a large 20,000 lbf shaker, and an impact modal test in this fixed configuration was conducted. Lastly, a vibration test of the Jim Beam was conducted on the shaker table. The free-free impact test, the fixed impact test, and the base-drive test were used to assess the effect of the shaker modes, evaluate the validity of fixed-base modeling assumptions, and compare final model correlation results between these

  12. Comparative results of gastric submucosal injection with hydroxypropyl methylcellulose, carboxymethylcellulose and normal saline solution in a porcine model Resultados comparativos de injeção submucosa gástrica com hidroximetil celulose, carboximetilcelulose e soro fisiológico em modelo suíno

    Directory of Open Access Journals (Sweden)

    Luciano Lenz

    2010-06-01

    Full Text Available CONTEXT: Endoscopic mucosal resection is an established modality for excision of sessile lesions in the gastrointestinal tract. Submucosal fluid injection creates a cushion and may prevent thermal injury and perforation. OBJECTIVES: This blind study investigated the performance of three different solutions to create submucosal fluid cushions in porcine stomach. METHODS: Three solutions were injected in the stomach of nine pigs BR1: normal saline solution, carboxymethylcellulose 0.5% and hydroxypropyl methylcellulose 0.25%. In each pig, submucosal injections with 6 mL per test-solution were performed. One drop of methylene blue was added to all injections for better visualization. The time for the bleb to disappear was recorded. RESULTS: The overall median time of visible submucosal cushion was 37 minutes (range 12-60 min for hydroxypropyl methylcellulose, 31 minutes for carboxymethylcellulose (range 10-43 min and 19 minutes for normal saline solution (range 8-37 min. There was no statistically significant difference neither between normal saline solution and carboxymethylcellulose (P = 0.146 nor carboxymethylcellulose and hydroxypropyl methylcellulose (P = 0.119 but the median duration of hydroxypropyl methylcellulose was significantly longer than normal saline solution (P = 0.039. CONCLUSIONS: The length of hydroxypropyl methylcellulose submucosal fluid cushion is longer in comparison with normal saline solution. The median time for carboxymethylcellulose was not longer than normal saline solution. Hydroxypropyl methylcellulose, in the concentration of 0.25%, may be a durable alternative for submucosal injection.CONTEXTO: A ressecção endoscópica mucosa é uma modalidade estabelecida para a excisão de lesões sésseis no trato gastrointestinal. A injeção de fluídos na submucosa cria uma coxim que pode prevenir lesão térmica e perfuração. OBJETIVO: Este estudo cego investiga o desempenho de três diferentes soluções para criar um

  13. A blended design in acute care training: similar learning results, less training costs compared with a traditional format.

    Science.gov (United States)

    Dankbaar, Mary E W; Storm, Diana J; Teeuwen, Irene C; Schuit, Stephanie C E

    2014-09-01

    Introduction There is a demand for more attractive and efficient training programmes in postgraduate health care training. This retrospective study aims to show the effectiveness of a blended versus traditional face-to-face training design. For nurses in postgraduate Acute and Intensive Care training, the effectiveness of a blended course design was compared with a traditional design. Methods In a first pilot study 57 students took a traditional course (2-h lecture and 2-h workshop) and 46 students took a blended course (2-h lecture and 2-h online self-study material). Test results were compared for both groups. After positive results in the pilot study, the design was replicated for the complete programme in Acute and Intensive Care. Now 16 students followed the traditional programme (11 days face-to-face education) and 31 students did the blended programme (7 days face-to-face and 40 h online self-study). An evaluation was done after the pilot and course costs were calculated. Results Results show that the traditional and blended groups were similar regarding the main characteristics and did not differ in learning results for both the pilot and the complete programme. Student evaluations of both designs were positive; however, the blended group were more confident that they had achieved the learning objectives. Training costs were reduced substantially. Conclusion The blended training design offers an effective and attractive training solution, leading to a significant reduction in costs.

  14. Tuning supersymmetric models at the LHC: A comparative analysis at two-loop level

    CERN Document Server

    Ghilencea, D M; Park, M

    2012-01-01

    We provide a comparative study of the fine tuning amount (Delta) at the two-loop leading log level in supersymmetric models commonly used in SUSY searches at the LHC. These are the constrained MSSM (CMSSM), non-universal Higgs masses models (NUHM1, NUHM2), non-universal gaugino masses model (NUGM) and GUT related gaugino masses models (NUGMd). Two definitions of the fine tuning are used, the first (Delta_{max}) measures maximal fine-tuning wrt individual parameters while the second (Delta_q) adds their contribution in "quadrature". As a direct result of two theoretical constraints (the EW minimum conditions), fine tuning (Delta_q) emerges as a suppressing factor (effective prior) of the averaged likelihood (under the priors), under the integral of the global probability of measuring the data (Bayesian evidence p(D)). For each model, there is little difference between Delta_q, Delta_{max} in the region allowed by the data, with similar behaviour as functions of the Higgs, gluino, stop mass or SUSY scale (m_{su...

  15. The impact of air traffic in the NAFC. Model results and measurements

    Energy Technology Data Exchange (ETDEWEB)

    Wauben, W.M.F.; Velthoven, P.F.J. van; Kelder, H.M. [Koninklijk Nederlands Meteorologisch Inst., De Bilt (Netherlands)

    1997-12-31

    The impact of aircraft emissions on the atmospheric composition has been investigated with a global chemistry transport model. The model calculations show that aircraft emissions of nitrogen oxides contribute to about 40-80% of the background values of nitrogen oxides in the North Atlantic Flight Corridor (NAFC), and lead to an increase of the background ozone concentrations by about 3-4% in winter and 5-7% in summer. The three-dimensional distributions of ozone, nitrogen oxides and nitric acid, calculated by using analysed meteorological data, have been compared with airborne measurements performed in the North Atlantic Flight Corridor as part of the EC POLINAT project. The agreement between modelled results and observations is reasonably good for ozone, but worse for nitrogen oxides and nitric acid. (author) 12 refs.

  16. Comparison of TS and ANN Models with the Results of Emission Scenarios in Rainfall Prediction

    Directory of Open Access Journals (Sweden)

    S. Babaei Hessar

    2016-02-01

    Full Text Available Introduction: Precipitation is one of the most important and sensitive parameters of the tropical climate that influence the catchments hydrological regime. The prediction of rainfall is vital for strategic planning and water resources management. Despite its importance, statistical rainfall forecasting, especially for long-term, has been proven to be a great challenge due to the dynamic nature of climate phenomena and random fluctuations involved in the process. Various methods, such as time series and artificial neural network models, have been proposed to predict the level of rainfall. But there is not enough attention to global warming and climate change issues. The main aim of this study is to investigate the conformity of artificial neural network and time series models with climate scenarios. Materials and Methods: For this study, 50 years of daily rainfall data (1961 to 2010 of the synoptic station of Urmia, Tabriz and Khoy was investigated. Data was obtained from Meteorological Organization of Iran. In the present study, the results of two Artificial Neural Network (ANN and Time Seri (TS methods were compared with the result of the Emission Scenarios (A2 & B1. HadCM3 model in LARS-WG software was used to generate rainfall for the next 18 years (2011-2029. The results of models were compared with climate scenarios over the next 18 years in the three synoptic stations located in the basin of the Lake Urmia. At the first stage, the best model of time series method was selected. The precipitation was estimated for the next 18 years using these models. For the same period, precipitation was forecast using artificial neural networks. Finally, the results of two models were compared with data generated under two scenarios (B1 and A2 in LARS-WG. Results and Discussion: Different order of AR, MA and ARMA was examined to select the best model of TS The results show that AR(1 was suitable for Tabriz and Khoy stations .In the Urmia station MA(1 was

  17. PV Performance Modeling Methods and Practices: Results from the 4th PV Performance Modeling Collaborative Workshop.

    Energy Technology Data Exchange (ETDEWEB)

    Stein, Joshua [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-03-01

    In 2014, the IEA PVPS Task 13 added the PVPMC as a formal activity to its technical work plan for 2014-2017. The goal of this activity is to expand the reach of the PVPMC to a broader international audience and help to reduce PV performance modeling uncertainties worldwide. One of the main deliverables of this activity is to host one or more PVPMC workshops outside the US to foster more international participation within this collaborative group. This report reviews the results of the first in a series of these joint IEA PVPS Task 13/PVPMC workshops. The 4th PV Performance Modeling Collaborative Workshop was held in Cologne, Germany at the headquarters of TÜV Rheinland on October 22-23, 2015.

  18. Comparative modeling of Bronze Age land use in the Malatya Plain (Turkey)

    Science.gov (United States)

    Arıkan, Bülent; Restelli, Francesca Balossi; Masi, Alessia

    2016-03-01

    Computational modeling in archeology has proven to be a useful tool in quantifying changes in the paleoenvironment. This especially useful method combines data from diverse disciplines to answer questions focusing on the complex and non-linear aspects of human-environment interactions. The research presented here uses various proxy records to compare the changes in climate during the Bronze Age in the Malatya Plain in eastern Anatolia, which is situated at the northern extremity of northern Mesopotamia. Extensive agropastoral land use modeling was applied to three sites of different size and function in the Malatya Plain during the Early Bronze Age I period to simulate the varying scale and intensity of human impacts in relation to changes in the level of social organization, demography, and temporal length. The results suggest that even in land use types subjected to a light footprint, the scale and intensity of anthropogenic impacts change significantly in relation to the level of social organization.

  19. Deposition and removal of fugitive dust in the arid southwestern United States: measurements and model results.

    Science.gov (United States)

    Etyemezian, Vic; Ahonen, Sean; Nikolic, Djordje; Gillies, John; Kuhns, Hampden; Gillette, Dale; Veranth, John

    2004-09-01

    This work was motivated by the need to better reconcile emission factors for fugitive dust with the amount of geologic material found on ambient filter samples. The deposition of particulate matter with aerodynamic diameter less than or equal to 10 microm (PM10), generated by travel over an unpaved road, over the first 100 m of transport downwind of the road was examined at Ft. Bliss, near El Paso, TX. The field conditions, typical for warm days in the arid southwestern United States, represented sparsely vegetated terrain under neutral to unstable atmospheric conditions. Emission fluxes of PM10 dust were obtained from towers downwind of the unpaved road at 7, 50, and 100 m. The horizontal flux measurements at the 7 m and 100 m towers indicated that PM10 deposition to the vegetation and ground was too small to measure. The data indicated, with 95% confidence, that the loss of PM10 between the source of emission at the unpaved road, represented by the 7 m tower, and a point 100 m downwind was less than 9.5%. A Gaussian model was used to simulate the plume. Values of the vertical standard deviation sigma(z) and the deposition velocity Vd were similar to the U.S. Environmental Protection Agency (EPA) ISC3 model. For the field conditions, the model predicted that removal of PM10 unpaved road dust by deposition over the distance between the point of emission and 100 m downwind would be less than 5%. However, the model results also indicated that particles larger than 10 microm (aerodynamic diameter) would deposit more appreciably. The model was consistent with changes observed in size distributions between 7 m and 100 m downwind, which were measured with optical particle counters. The Gaussian model predictions were also compared with another study conducted over rough terrain and stable atmospheric conditions. Under such conditions, measured PM10 removal rates over 95 m of downwind transport were reported to be between 86% and 89%, whereas the Gaussian model predicted

  20. A comparative study of generalized linear mixed modelling and artificial neural network approach for the joint modelling of survival and incidence of Dengue patients in Sri Lanka

    Science.gov (United States)

    Hapugoda, J. C.; Sooriyarachchi, M. R.

    2017-09-01

    Survival time of patients with a disease and the incidence of that particular disease (count) is frequently observed in medical studies with the data of a clustered nature. In many cases, though, the survival times and the count can be correlated in a way that, diseases that occur rarely could have shorter survival times or vice versa. Due to this fact, joint modelling of these two variables will provide interesting and certainly improved results than modelling these separately. Authors have previously proposed a methodology using Generalized Linear Mixed Models (GLMM) by joining the Discrete Time Hazard model with the Poisson Regression model to jointly model survival and count model. As Aritificial Neural Network (ANN) has become a most powerful computational tool to model complex non-linear systems, it was proposed to develop a new joint model of survival and count of Dengue patients of Sri Lanka by using that approach. Thus, the objective of this study is to develop a model using ANN approach and compare the results with the previously developed GLMM model. As the response variables are continuous in nature, Generalized Regression Neural Network (GRNN) approach was adopted to model the data. To compare the model fit, measures such as root mean square error (RMSE), absolute mean error (AME) and correlation coefficient (R) were used. The measures indicate the GRNN model fits the data better than the GLMM model.