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Sample records for predicting field performance

  1. Thermal system field performance predictions from laboratory and field measurements

    NASA Astrophysics Data System (ADS)

    Burks, Stephen D.; Haefner, David P.; Teaney, Brian P.; Doe, Joshua M.

    2016-05-01

    Laboratory measurements on thermal imaging systems are critical to understanding their performance in a field environment. However, it is rarely a straightforward process to directly inject thermal measurements into thermal performance modeling software to acquire meaningful results. Some of the sources of discrepancies between laboratory and field measurements are sensor gain and level, dynamic range, sensor display and display brightness, and the environment where the sensor is operating. If measurements for the aforementioned parameters could be performed, a more accurate description of sensor performance in a particular environment is possible. This research will also include the procedure for turning both laboratory and field measurements into a system model.

  2. PREDICTING FIELD PERFORMANCE OF HERBACEOUS SPECIES FOR PHYTOREMEDIATION OF PERCHLORATE

    EPA Science Inventory

    Results of these short-term experiments coupled with ecological knowledge of the nine herbaceous plant species tested suggest that several species may by successful in on-site remediation of perchlorate. The two wetland species which appear to be most suitable for field experimen...

  3. A target detection model predicting field observer performance in maritime scenes

    NASA Astrophysics Data System (ADS)

    Culpepper, Joanne B.; Wheaton, Vivienne C.

    2014-10-01

    The U.S. Army's target acquisition models, the ACQUIRE and Target Task Performance (TTP) models, have been employed for many years to assess the performance of thermal infrared sensors. In recent years, ACQUIRE and the TTP models have been adapted to assess the performance of visible sensors. These adaptations have been primarily focused on the performance of an observer viewing a display device. This paper describes an implementation of the TTP model to predict field observer performance in maritime scenes. Predictions of the TTP model implementation were compared to observations of a small watercraft taken in a field trial. In this field trial 11 Australian Navy observers viewed a small watercraft in an open ocean scene. Comparisons of the observed probability of detection to predictions of the TTP model implementation showed the normalised RSS metric overestimated the probability of detection. The normalised Pixel Contrast using a literature value for V50 yielded a correlation of 0.58 between the predicted and observed probability of detection. With a measured value of N50 or V50 for the small watercraft used in this investigation, this implementation of the TTP model may yield stronger correlation with observed probability of detection.

  4. Accomplishments and Compromises in Prediction Research for World Records and Best Performances in Track and Field and Swimming

    ERIC Educational Resources Information Center

    Liu, Yuanlong; Paul, Stanley; Fu, Frank H.

    2012-01-01

    The conductors of this study reviewed prediction research and studied the accomplishments and compromises in predicting world records and best performances in track and field and swimming. The results of the study showed that prediction research only promises to describe the historical trends in track and field and swimming performances, to study…

  5. Predictions of long-term performance of granular iron permeable reactive barriers: field-scale evaluation.

    PubMed

    Jeen, Sung-Wook; Gillham, Robert W; Przepiora, Andrzej

    2011-04-01

    Long-term performance is a key consideration for the granular iron permeable reactive barrier (PRB) technology because the economic benefit relies on sustainable operation for substantial periods of time. However, predictions on the long-term performance have been limited mainly because of the lack of reliable modeling tools. This study evaluated the predictive capability of a recently-developed reactive transport model at two field-scale PRBs, both having relatively high concentrations of dissolved carbonate in the native groundwater. The first site, with 8 years of available monitoring data, was a funnel-and-gate installation, with a low groundwater velocity through the gate (about 0.12 m d(-1)). The loss in iron reactivity caused by secondary mineral precipitation was small, maintaining relatively high removal rates for chlorinated organics. The simulated concentrations for most constituents in the groundwater were within the range of the monitoring data. The second site, with monitoring data available for 5 years, was a continuous wall PRB, designed for a groundwater velocity of 0.9 m d(-1). A comparison of measured and simulated aqueous concentrations suggested that the average groundwater velocity through the PRB could be lower than the design value by a factor of two or more. The distribution and amounts of carbonate minerals measured in core samples supported the decreased groundwater velocity used in the simulation. The generally good agreement between the simulated and measured aqueous and solid-phase data suggest that the model could be an effective tool for predicting long-term performance of granular iron PRBs, particularly in groundwater with high concentrations of carbonate. PMID:21237528

  6. The Ahuachapan geothermal field, El Salvador: Exploitation model, performance predictions, economic analysis

    SciTech Connect

    Ripperda, M.; Bodvarsson, G.S.; Lippmann, M.J.; Witherspoon, P.A.; Goranson, C.

    1991-05-01

    The Earth Sciences Division of Lawrence Berkeley Laboratory (LBL) is conducting a reservoir evaluation study of the Ahuachapan geothermal field in El Salvador. This work is being performed in cooperation with the Comision Ejecutiva Hidroelectrica del Rio Lempa (CEL) and the Los Alamos National Laboratory (LANL) with funding from the US Agency for International Development (USAID). This report describes the work done during the second year of the study (FY89--90). The first year's report included (1) the development of geological and conceptual models of the field, (2) the evaluation of the reservoir's initial thermodynamic and chemical conditions and their changes during exploitation, (3) the evaluation of interference test data and the observed reservoir pressure decline and (4) the development of a natural state model for the field. In the present report the results of reservoir engineering studies to evaluate different production-injection scenarios for the Ahuachapan geothermal field are discussed. The purpose of the work was to evaluate possible reservoir management options to enhance as well as to maintain the productivity of the field during a 30-year period (1990--2020). The ultimate objective was to determine the feasibility of increasing the electrical power output at Ahuachapan from the current level of about 50 MW{sub e} to the total installed capacity of 95 MW{sub e}. 20 refs., 75 figs., 10 tabs.

  7. Testing the near field/far field model performance for prediction of particulate matter emissions in a paint factory.

    PubMed

    Koivisto, A J; Jensen, A C Ø; Levin, M; Kling, K I; Maso, M Dal; Nielsen, S H; Jensen, K A; Koponen, I K

    2015-01-01

    A Near Field/Far Field (NF/FF) model is a well-accepted tool for precautionary exposure assessment but its capability to estimate particulate matter (PM) concentrations is not well studied. The main concern is related to emission source characterization which is not as well defined for PM emitters compared to e.g. for solvents. One way to characterize PM emission source strength is by using the material dustiness index which is scaled to correspond to industrial use by using modifying factors, such as handling energy factors. In this study we investigate how well the NF/FF model predicts PM concentration levels in a paint factory. PM concentration levels were measured during big bag and small bag powder pouring. Rotating drum dustiness indices were determined for the specific powders used and applied in the NF/FF model to predict mass concentrations. Modeled process specific concentration levels were adjusted to be similar to the measured concentration levels by adjusting the handling energy factor. The handling energy factors were found to vary considerably depending on the material and process even-though they have the same values as modifying factors in the exposure models. This suggests that the PM source characteristics and process-specific handling energies should be studied in more detail to improve the model-based exposure assessment. PMID:25407261

  8. The productive performance prediction of some wells in Hachijojima hydrothermal field, Japan

    SciTech Connect

    Nobuhiro Demboya; Jun-ichi Ishikawa; Nobuyuki Iwai; Yoneko Tada

    1993-01-28

    New Energy and Industrial Technology Development Organization (NEDO) did "Geothermal Development Promotion Survey" in the Hachijojima Island which is a volcanic island with 70km² located in the Izu-Mariana Island Arc. In that national project, NEDO drilled 8 wells in the field and the maximum temperature of the field was 317°C at 1200m depth of a well. Of these survey NEDO confirmed the existence of geothermal reservoir, and using a well named HJ-5, NEDO did short time discharge test. The authors calculated borehole temperature and pressure under production the of the well in comparison with the measured data. The authors also calculated productive performance of another well named HJ-8.

  9. Can laboratory-based tennis profiles predict field tests of tennis performance?

    PubMed

    Perry, Arlette C; Wang, Xuewen; Feldman, Brandon B; Ruth, Tiffany; Signorile, Joseph

    2004-02-01

    The present study examined the impact of physical characteristics of adolescent competitive tennis players (13-18 years) on field tests of tennis performance. Results (n = 33) showed that boys were taller (p = 0.001), possessed greater wingspan (p = 0.030), had greater maximum oxygen consumption (p = 0.001), and performed better on isokinetic strength measurements. Multiple regression analyses controlling for age and sex showed that height (p = 0.025), maximum minute ventilation (p = 0.005), and isokinetic strength measurements significantly and positively affected ball velocity. Knee extension average power was the only variable to positively and significantly affect ball placement (p = 0.040); however, several isokinetic strength measurements negatively affected ball placement. For the nondominant side, down-the-line strokes showed reduced accuracy (p = 0.001) and ball velocity (p = 0.001) compared with cross-court strokes. Given our results, resistance training may be beneficial for the performance of on-court tennis play. PMID:14971970

  10. Macropore flow at the field scale: predictive performance of empirical models and X-ray CT analyzed macropore characteristics

    NASA Astrophysics Data System (ADS)

    Naveed, M.; Moldrup, P.; Schaap, M.; Tuller, M.; Kulkarni, R.; Vögel, H.-J.; Wollesen de Jonge, L.

    2015-11-01

    Predictions of macropore flow is important for maintaining both soil and water quality as it governs key related soil processes e.g. soil erosion and subsurface transport of pollutants. However, macropore flow currently cannot be reliably predicted at the field scale because of inherently large spatial variability. The aim of this study was to perform field scale characterization of macropore flow and investigate the predictive performance of (1) current empirical models for both water and air flow, and (2) X-ray CT derived macropore network characteristics. For this purpose, 65 cylindrical soil columns (6 cm diameter and 3.5 cm height) were extracted from the topsoil (5 to 8.5 cm depth) in a 15 m × 15 m grid from an agricultural loamy field located in Silstrup, Denmark. All soil columns were scanned with an industrial CT scanner (129 μm resolution) and later used for measurements of saturated water permeability, air permeability and gas diffusivity at -30 and -100 cm matric potentials. Distribution maps for both water and air permeabilities and gas diffusivity reflected no spatial correlation irrespective of the soil texture and organic matter maps. Empirical predictive models for both water and air permeabilities showed poor performance as they were not able to realistically capture macropore flow because of poor correlations with soil texture and bulk density. The tested empirical model predicted well gas diffusivity at -100 cm matric potential, but relatively failed at -30 cm matric potential particularly for samples with biopore flow. Image segmentation output of the four employed methods was nearly the same, and matched well with measured air-filled porosity at -30 cm matric potential. Many of the CT derived macropore network characteristics were strongly interrelated. Most of the macropore network characteristics were also strongly correlated with saturated water permeability, air permeability, and gas diffusivity. The correlations between macropore

  11. PREVAPORATION PERFORMANCE PREDICTION SOFTWARE

    EPA Science Inventory

    The Pervaporation, Performance, Prediction Software and Database (PPPS&D) computer software program is currently being developed within the USEPA, NRMRL. The purpose of the PPPS&D program is to educate and assist potential users in identifying opportunities for using pervaporati...

  12. Uncertainty in Predicted Neighborhood-Scale Green Stormwater Infrastructure Performance Informed by field monitoring of Hydrologic Abstractions

    NASA Astrophysics Data System (ADS)

    Smalls-Mantey, L.; Jeffers, S.; Montalto, F. A.

    2013-12-01

    Human alterations to the environment provide infrastructure for housing and transportation but have drastically changed local hydrology. Excess stormwater runoff from impervious surfaces generates erosion, overburdens sewer infrastructure, and can pollute receiving bodies. Increased attention to green stormwater management controls is based on the premise that some of these issues can be mitigated by capturing or slowing the flow of stormwater. However, our ability to predict actual green infrastructure facility performance using physical or statistical methods needs additional validation, and efforts to incorporate green infrastructure controls into hydrologic models are still in their infancy stages. We use more than three years of field monitoring data to derive facility specific probability density functions characterizing the hydrologic abstractions provided by a stormwater treatment wetland, streetside bioretention facility, and a green roof. The monitoring results are normalized by impervious area treated, and incorporated into a neighborhood-scale agent model allowing probabilistic comparisons of the stormwater capture outcomes associated with alternative urban greening scenarios. Specifically, we compare the uncertainty introduced into the model by facility performance (as represented by the variability in the abstraction), to that introduced by both precipitation variability, and spatial patterns of emergence of different types of green infrastructure. The modeling results are used to update a discussion about the potential effectiveness of urban green infrastructure implementation plans.

  13. EVA Performance Prediction

    NASA Technical Reports Server (NTRS)

    Peacock, Brian; Maida, James; Rajulu, Sudhakar

    2004-01-01

    out for EVA activities are based more on extensive domain experience than any formal analytic structure. Conversely, physical task analysis for industrial and structured evidence from training and EV A contexts. Again on earth there is considerable evidence of human performance degradation due to encumbrance and fatigue. These industrial models generally take the form of a discounting equation. The development of performance estimates for space operations, such as timeline predictions for EVA is generally based on specific input from training activity, for example in the NBL or KC135. uniformed services tasks on earth are much more formalized. Human performance data in the space context has two sources: first there is the micro analysis of performance in structured tasks by the space physiology community and second there is the less structured evidence from training and EV A contexts.

  14. Validation of a simple model to predict the performance of methane oxidation systems, using field data from a large scale biocover test field.

    PubMed

    Geck, Christoph; Scharff, Heijo; Pfeiffer, Eva-Maria; Gebert, Julia

    2016-10-01

    On a large scale test field (1060m(2)) methane emissions were monitored over a period of 30months. During this period, the test field was loaded at rates between 14 and 46gCH4m(-2)d(-1). The total area was subdivided into 60 monitoring grid fields at 17.7m(2) each, which were individually surveyed for methane emissions and methane oxidation efficiency. The latter was calculated both from the direct methane mass balance and from the shift of the carbon dioxide - methane ratio between the base of the methane oxidation layer and the emitted gas. The base flux to each grid field was back-calculated from the data on methane oxidation efficiency and emission. Resolution to grid field scale allowed the analysis of the spatial heterogeneity of all considered fluxes. Higher emissions were measured in the upslope area of the test field. This was attributed to the capillary barrier integrated into the test field resulting in a higher diffusivity and gas permeability in the upslope area. Predictions of the methane oxidation potential were estimated with the simple model Methane Oxidation Tool (MOT) using soil temperature, air filled porosity and water tension as input parameters. It was found that the test field could oxidize 84% of the injected methane. The MOT predictions seemed to be realistic albeit the higher range of the predicted oxidations potentials could not be challenged because the load to the field was too low. Spatial and temporal emission patterns were found indicating heterogeneity of fluxes and efficiencies in the test field. No constant share of direct emissions was found as proposed by the MOT albeit the mean share of emissions throughout the monitoring period was in the range of the expected emissions. PMID:27426022

  15. Laboratory Performance Predicts the Success of Field Releases in Inbred Lines of the Egg Parasitoid Trichogramma pretiosum (Hymenoptera: Trichogrammatidae)

    PubMed Central

    Coelho, Aloisio; Rugman-Jones, Paul F.; Reigada, Carolina; Stouthamer, Richard; Parra, José R. P.

    2016-01-01

    In this study we assessed the relationship between the laboratory and field performance of different isofemale lines of Trichogramma pretiosum Riley. In comparative assays, we used three rare mitochondrial haplotypes as genetic markers of the isofemale lines, and by introgressing these mitochondrial haplotypes into each of 15 genetically different nuclear lines, also tested the assumption that mitochondria are neutral markers. In a laboratory trial, 45 isofemale lines (15 nuclear genotypes x three mitochondrial haplotypes) were ranked in three categories (best, intermediate and worst) according to the mean offspring production and the proportion of female offspring. Subsequently, lines from each of the three categories were selected for field releases to quantify field parasitism on Ephestia kuehniella. Temporally separate releases were done in a transgenic Bt cornfield, with four plots, each with 50 points of recapture. The points of recapture consisted of trap cards with eggs of E. kuehniella collected daily. The trap cards were maintained in the laboratory at 25°C until the adult wasps emerged, and the maternal identity of the wasps was determined using qPCR and high-resolution melt curve analysis to determine the mitochondrial haplotype. The results showed that these measures of laboratory performance (fecundity and offspring sex ratio) were good predictors of field success in T. pretiosum. We also report strong evidence discrediting the assumption that mitochondria are neutral, in view of the correlation between performance and mitochondrial haplotype. PMID:26730735

  16. PREDICTING TURBINE STAGE PERFORMANCE

    NASA Technical Reports Server (NTRS)

    Boyle, R. J.

    1994-01-01

    This program was developed to predict turbine stage performance taking into account the effects of complex passage geometries. The method uses a quasi-3D inviscid-flow analysis iteratively coupled to calculated losses so that changes in losses result in changes in the flow distribution. In this manner the effects of both the geometry on the flow distribution and the flow distribution on losses are accounted for. The flow may be subsonic or shock-free transonic. The blade row may be fixed or rotating, and the blades may be twisted and leaned. This program has been applied to axial and radial turbines, and is helpful in the analysis of mixed flow machines. This program is a combination of the flow analysis programs MERIDL and TSONIC coupled to the boundary layer program BLAYER. The subsonic flow solution is obtained by a finite difference, stream function analysis. Transonic blade-to-blade solutions are obtained using information from the finite difference, stream function solution with a reduced flow factor. Upstream and downstream flow variables may vary from hub to shroud and provision is made to correct for loss of stagnation pressure. Boundary layer analyses are made to determine profile and end-wall friction losses. Empirical loss models are used to account for incidence, secondary flow, disc windage, and clearance losses. The total losses are then used to calculate stator, rotor, and stage efficiency. This program is written in FORTRAN IV for batch execution and has been implemented on an IBM 370/3033 under TSS with a central memory requirement of approximately 4.5 Megs of 8 bit bytes. This program was developed in 1985.

  17. Comparing performances of logistic regression and neural networks for predicting melatonin excretion patterns in the rat exposed to ELF magnetic fields.

    PubMed

    Jahandideh, Samad; Abdolmaleki, Parviz; Movahedi, Mohammad Mehdi

    2010-02-01

    Various studies have been reported on the bioeffects of magnetic field exposure; however, no consensus or guideline is available for experimental designs relating to exposure conditions as yet. In this study, logistic regression (LR) and artificial neural networks (ANNs) were used in order to analyze and predict the melatonin excretion patterns in the rat exposed to extremely low frequency magnetic fields (ELF-MF). Subsequently, on a database containing 33 experiments, performances of LR and ANNs were compared through resubstitution and jackknife tests. Predictor variables were more effective parameters and included frequency, polarization, exposure duration, and strength of magnetic fields. Also, five performance measures including accuracy, sensitivity, specificity, Matthew's Correlation Coefficient (MCC) and normalized percentage, better than random (S) were used to evaluate the performance of models. The LR as a conventional model obtained poor prediction performance. Nonetheless, LR distinguished the duration of magnetic fields as a statistically significant parameter. Also, horizontal polarization of magnetic fields with the highest logit coefficient (or parameter estimate) with negative sign was found to be the strongest indicator for experimental designs relating to exposure conditions. This means that each experiment with horizontal polarization of magnetic fields has a higher probability to result in "not changed melatonin level" pattern. On the other hand, ANNs, a more powerful model which has not been introduced in predicting melatonin excretion patterns in the rat exposed to ELF-MF, showed high performance measure values and higher reliability, especially obtaining 0.55 value of MCC through jackknife tests. Obtained results showed that such predictor models are promising and may play a useful role in defining guidelines for experimental designs relating to exposure conditions. In conclusion, analysis of the bioelectromagnetic data could result in

  18. Scaling maximal oxygen uptake to predict cycling time-trial performance in the field: a non-linear approach.

    PubMed

    Nevill, A M; Jobson, S A; Palmer, G S; Olds, T S

    2005-08-01

    The purpose of the present article is to identify the most appropriate method of scaling VO2max for differences in body mass when assessing the energy cost of time-trial cycling. The data from three time-trial cycling studies were analysed (N = 79) using a proportional power-function ANCOVA model. The maximum oxygen uptake-to-mass ratio found to predict cycling speed was VO2max(m)(-0.32) precisely the same as that derived by Swain for sub-maximal cycling speeds (10, 15 and 20 mph). The analysis was also able to confirm a proportional curvilinear association between cycling speed and energy cost, given by (VO2max(m)(-0.32))0.41. The model predicts, for example, that for a male cyclist (72 kg) to increase his average speed from 30 km h(-1) to 35 km h(-1), he would require an increase in VO2max from 2.36 l min(-1) to 3.44 l min(-1), an increase of 1.08 l min(-1). In contrast, for the cyclist to increase his mean speed from 40 km h(-1) to 45 km h(-1), he would require a greater increase in VO2max from 4.77 l min(-1) to 6.36 l min(-1), i.e. an increase of 1.59 l min(-1). The model is also able to accommodate other determinants of time-trial cycling, e.g. the benefit of cycling with a side wind (5% faster) compared with facing a predominately head/tail wind (P<0.05). Future research could explore whether the same scaling approach could be applied to, for example, alternative measures of recording power output to improve the prediction of time-trial cycling performance. PMID:15906080

  19. A predictive analytic model for high-performance tunneling field-effect transistors approaching non-equilibrium Green's function simulations

    SciTech Connect

    Salazar, Ramon B. E-mail: hilatikh@purdue.edu; Appenzeller, Joerg; Ilatikhameneh, Hesameddin E-mail: hilatikh@purdue.edu; Rahman, Rajib; Klimeck, Gerhard

    2015-10-28

    A new compact modeling approach is presented which describes the full current-voltage (I-V) characteristic of high-performance (aggressively scaled-down) tunneling field-effect-transistors (TFETs) based on homojunction direct-bandgap semiconductors. The model is based on an analytic description of two key features, which capture the main physical phenomena related to TFETs: (1) the potential profile from source to channel and (2) the elliptic curvature of the complex bands in the bandgap region. It is proposed to use 1D Poisson's equations in the source and the channel to describe the potential profile in homojunction TFETs. This allows to quantify the impact of source/drain doping on device performance, an aspect usually ignored in TFET modeling but highly relevant in ultra-scaled devices. The compact model is validated by comparison with state-of-the-art quantum transport simulations using a 3D full band atomistic approach based on non-equilibrium Green's functions. It is shown that the model reproduces with good accuracy the data obtained from the simulations in all regions of operation: the on/off states and the n/p branches of conduction. This approach allows calculation of energy-dependent band-to-band tunneling currents in TFETs, a feature that allows gaining deep insights into the underlying device physics. The simplicity and accuracy of the approach provide a powerful tool to explore in a quantitatively manner how a wide variety of parameters (material-, size-, and/or geometry-dependent) impact the TFET performance under any bias conditions. The proposed model presents thus a practical complement to computationally expensive simulations such as the 3D NEGF approach.

  20. A predictive analytic model for high-performance tunneling field-effect transistors approaching non-equilibrium Green's function simulations

    NASA Astrophysics Data System (ADS)

    Salazar, Ramon B.; Ilatikhameneh, Hesameddin; Rahman, Rajib; Klimeck, Gerhard; Appenzeller, Joerg

    2015-10-01

    A new compact modeling approach is presented which describes the full current-voltage (I-V) characteristic of high-performance (aggressively scaled-down) tunneling field-effect-transistors (TFETs) based on homojunction direct-bandgap semiconductors. The model is based on an analytic description of two key features, which capture the main physical phenomena related to TFETs: (1) the potential profile from source to channel and (2) the elliptic curvature of the complex bands in the bandgap region. It is proposed to use 1D Poisson's equations in the source and the channel to describe the potential profile in homojunction TFETs. This allows to quantify the impact of source/drain doping on device performance, an aspect usually ignored in TFET modeling but highly relevant in ultra-scaled devices. The compact model is validated by comparison with state-of-the-art quantum transport simulations using a 3D full band atomistic approach based on non-equilibrium Green's functions. It is shown that the model reproduces with good accuracy the data obtained from the simulations in all regions of operation: the on/off states and the n/p branches of conduction. This approach allows calculation of energy-dependent band-to-band tunneling currents in TFETs, a feature that allows gaining deep insights into the underlying device physics. The simplicity and accuracy of the approach provide a powerful tool to explore in a quantitatively manner how a wide variety of parameters (material-, size-, and/or geometry-dependent) impact the TFET performance under any bias conditions. The proposed model presents thus a practical complement to computationally expensive simulations such as the 3D NEGF approach.

  1. Experimental prediction of performance by superconducting cables

    NASA Technical Reports Server (NTRS)

    Brooks, J. M.; Purcell, J. R.

    1969-01-01

    Broken superconductor method of short sample testing makes possible the prediction of the performance of well cooled, stabilized, superconducting cable coils. It yields a field-versus-current curve for a short sample of cable. Plots are given for the superconductor and copper currents at various magnetic field strengths.

  2. Program Predicts Nonlinear Inverter Performance

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

  3. Initial Cognitive Performance Predicts Longitudinal Aviator Performance

    PubMed Central

    Jo, Booil; Adamson, Maheen M.; Kennedy, Quinn; Noda, Art; Hernandez, Beatriz; Zeitzer, Jamie M.; Friedman, Leah F.; Fairchild, Kaci; Scanlon, Blake K.; Murphy, Greer M.; Taylor, Joy L.

    2011-01-01

    Objectives. The goal of the study was to improve prediction of longitudinal flight simulator performance by studying cognitive factors that may moderate the influence of chronological age. Method. We examined age-related change in aviation performance in aircraft pilots in relation to baseline cognitive ability measures and aviation expertise. Participants were aircraft pilots (N = 276) aged 40–77.9. Flight simulator performance and cognition were tested yearly; there were an average of 4.3 (± 2.7; range 1–13) data points per participant. Each participant was classified into one of the three levels of aviation expertise based on Federal Aviation Administration pilot proficiency ratings: least, moderate, or high expertise. Results. Addition of measures of cognitive processing speed and executive function to a model of age-related change in aviation performance significantly improved the model. Processing speed and executive function performance interacted such that the slowest rate of decline in flight simulator performance was found in aviators with the highest scores on tests of these abilities. Expertise was beneficial to pilots across the age range studied; however, expertise did not show evidence of reducing the effect of age. Discussion. These data suggest that longitudinal performance on an important real-world activity can be predicted by initial assessment of relevant cognitive abilities. PMID:21586627

  4. Predictive performance models and multiple task performance

    NASA Technical Reports Server (NTRS)

    Wickens, Christopher D.; Larish, Inge; Contorer, Aaron

    1989-01-01

    Five models that predict how performance of multiple tasks will interact in complex task scenarios are discussed. The models are shown in terms of the assumptions they make about human operator divided attention. The different assumptions about attention are then empirically validated in a multitask helicopter flight simulation. It is concluded from this simulation that the most important assumption relates to the coding of demand level of different component tasks.

  5. Action perception predicts action performance

    PubMed Central

    Bailey, Heather R.; Kurby, Christopher A.; Giovannetti, Tania; Zacks, Jeffrey M.

    2013-01-01

    Everyday action impairments often are observed in demented older adults, and they are common potential barriers to functional independence. We evaluated whether the ability to segment and efficiently encode activities is related to the ability to execute activities. Further, we evaluated whether brain regions important for segmentation also were important for action performance. Cognitively healthy older adults and those with very mild or mild dementia of the Alzheimer's type watched and segmented movies of everyday activities and then completed the Naturalistic Action Test. Structural MRI was used to measure volume in the dorsolateral prefrontal cortex (DLPFC), medial temporal lobes (MTL), posterior cortex, and anterior cingulate cortex (ACC). Dementia status and the ability to segment everyday activities strongly predicted naturalistic action performance, and MTL volume largely accounted for this relationship. In addition, the current results supported the Omission-Commission Model: Different cognitive and neurological mechanisms predicted different types of action error. Segmentation, dementia severity, and MTL volume predicted everyday omission errors, DLPFC volume predicted commission errors, and ACC volume predicted action additions. These findings suggest that event segmentation may be critical for effective action production, and that the segmentation and production of activities may recruit the same event representation system. PMID:23851113

  6. TRITIUM RESERVOIR STRUCTURAL PERFORMANCE PREDICTION

    SciTech Connect

    Lam, P.S.; Morgan, M.J

    2005-11-10

    The burst test is used to assess the material performance of tritium reservoirs in the surveillance program in which reservoirs have been in service for extended periods of time. A materials system model and finite element procedure were developed under a Savannah River Site Plant-Directed Research and Development (PDRD) program to predict the structural response under a full range of loading and aged material conditions of the reservoir. The results show that the predicted burst pressure and volume ductility are in good agreement with the actual burst test results for the unexposed units. The material tensile properties used in the calculations were obtained from a curved tensile specimen harvested from a companion reservoir by Electric Discharge Machining (EDM). In the absence of exposed and aged material tensile data, literature data were used for demonstrating the methodology in terms of the helium-3 concentration in the metal and the depth of penetration in the reservoir sidewall. It can be shown that the volume ductility decreases significantly with the presence of tritium and its decay product, helium-3, in the metal, as was observed in the laboratory-controlled burst tests. The model and analytical procedure provides a predictive tool for reservoir structural integrity under aging conditions. It is recommended that benchmark tests and analysis for aged materials be performed. The methodology can be augmented to predict performance for reservoir with flaws.

  7. Synoptic Solar Magnetic Fields: Explored and Predicted

    NASA Astrophysics Data System (ADS)

    Lundstedt, H.; Wik, M.; Wintoft, P.

    2006-12-01

    Solar synoptic maps provide an important visualization of global patterns. Maps are available of sub-surface flows, photospheric and coronal magnetic fields. We have carried out a multiresolution analysis (MRA) of longitudinally averaged synoptic magnetograms. The magnetograms were observed at Wilcox Solar Observatory (WSO), Stanford and with Michelson Doppler Imager (MDI) onboard SOHO of ESA/NASA. We performed a multilevel wavelet decomposition of the solar magnetic field signal for each latitude. Trends and periods in the decomposed signal are shown. Solar cycle 24 is discussed. Predictions of the synoptic magnetic fields, using neural networks, have been developed. With the launch of Solar Dynamics Observatory (SDO), real-time synoptic maps will be available. That would be of great importance for real-time predictions of space weather effects.

  8. Predicting performance of parallel computations

    NASA Technical Reports Server (NTRS)

    Mak, Victor W.; Lundstrom, Stephen F.

    1990-01-01

    An accurate and computationally efficient method for predicting the performance of a class of parallel computations running on concurrent systems is described. A parallel computation is modeled as a task system with precedence relationships expressed as a series-parallel directed acyclic graph. Resources in a concurrent system are modeled as service centers in a queuing network model. Using these two models as inputs, the method outputs predictions of expected execution time of the parallel computation and the concurrent system utilization. The method is validated against both detailed simulation and actual execution on a commercial multiprocessor. Using 100 test cases, the average error of the prediction when compared to simulation statistics is 1.7 percent, with a standard deviation of 1.5 percent; the maximum error is about 10 percent.

  9. Conrad: gene prediction using conditional random fields.

    PubMed

    DeCaprio, David; Vinson, Jade P; Pearson, Matthew D; Montgomery, Philip; Doherty, Matthew; Galagan, James E

    2007-09-01

    We present Conrad, the first comparative gene predictor based on semi-Markov conditional random fields (SMCRFs). Unlike the best standalone gene predictors, which are based on generalized hidden Markov models (GHMMs) and trained by maximum likelihood, Conrad is discriminatively trained to maximize annotation accuracy. In addition, unlike the best annotation pipelines, which rely on heuristic and ad hoc decision rules to combine standalone gene predictors with additional information such as ESTs and protein homology, Conrad encodes all sources of information as features and treats all features equally in the training and inference algorithms. Conrad outperforms the best standalone gene predictors in cross-validation and whole chromosome testing on two fungi with vastly different gene structures. The performance improvement arises from the SMCRF's discriminative training methods and their ability to easily incorporate diverse types of information by encoding them as feature functions. On Cryptococcus neoformans, configuring Conrad to reproduce the predictions of a two-species phylo-GHMM closely matches the performance of Twinscan. Enabling discriminative training increases performance, and adding new feature functions further increases performance, achieving a level of accuracy that is unprecedented for this organism. Similar results are obtained on Aspergillus nidulans comparing Conrad versus Fgenesh. SMCRFs are a promising framework for gene prediction because of their highly modular nature, simplifying the process of designing and testing potential indicators of gene structure. Conrad's implementation of SMCRFs advances the state of the art in gene prediction in fungi and provides a robust platform for both current application and future research. PMID:17690204

  10. Predicting edge seal performance from accelerated testing

    NASA Astrophysics Data System (ADS)

    Hardikar, Kedar; Vitkavage, Dan; Saproo, Ajay; Krajewski, Todd

    2014-10-01

    Degradation in performance of a PV module attributable to moisture ingress has received significant attention in PV reliability research. Assessment of field performance of PV modules against moisture ingress through product-level testing in temperature-humidity control chambers poses challenges. Development of a meaningful acceleration factor model is challenging due to different rates of degradation of components embedded in a PV module, when exposed to moisture. Test results are typically a convolution of moisture barrier performance of the edge seal and degradation of laminated components when exposed to moisture. It is desirable to have an alternate method by which moisture barrier performance of the edge seal in its end product form can be assessed in any given field conditions, independent of particular cell design. In this work, a relatively inexpensive test technique was developed to test the edge seal in its end product form in a manner that is decoupled from other components of the PV module. A theoretical framework was developed to assess moisture barrier performance of edge seal with desiccants subjected to different conditions. This framework enables the analysis of test results from accelerated tests and prediction of the field performance of the edge seal. Results from this study lead to the conclusion that the edge seal on certain Miasole glass-glass modules studied is effective for the most aggressive weather conditions examined, beyond the intended service.

  11. Predicting Older Driver On-Road Performance by Means of the Useful Field of View and Trail Making Test Part B

    PubMed Central

    Wang, Yanning; Crizzle, Alexander M.; Winter, Sandra M.; Lanford, Desiree N.

    2013-01-01

    The Useful Field of View® (UFOV) and Trail Making Test Part B (Trails B) are measures of divided attention. We determined which measure was more accurate in predicting on-road outcomes among drivers (N = 198, mean age = 73.86, standard deviation = 6.05). Receiver operating characteristic curves for the UFOV (Risk Index [RI] and Subtests 1–3) and Trails B significantly predicted on-road outcomes. Contrasting Trails B with the UFOV RI and subtests, the only difference was found between the UFOV RI and Trails B, indicating the UFOV RI was the best predictor of on-road outcomes. Misclassifications of drivers totaled 28 for the UFOV RI, 62 for Trails B, and 58 for UFOV Subtest 2. The UFOV RI is a superior test in predicting on-road outcomes, but the Trails B has acceptable accuracy and is comparable to the other UFOV subtests. PMID:23968796

  12. DKIST Polarization Modeling and Performance Predictions

    NASA Astrophysics Data System (ADS)

    Harrington, David

    2016-05-01

    Calibrating the Mueller matrices of large aperture telescopes and associated coude instrumentation requires astronomical sources and several modeling assumptions to predict the behavior of the system polarization with field of view, altitude, azimuth and wavelength. The Daniel K Inouye Solar Telescope (DKIST) polarimetric instrumentation requires very high accuracy calibration of a complex coude path with an off-axis f/2 primary mirror, time dependent optical configurations and substantial field of view. Polarization predictions across a diversity of optical configurations, tracking scenarios, slit geometries and vendor coating formulations are critical to both construction and contined operations efforts. Recent daytime sky based polarization calibrations of the 4m AEOS telescope and HiVIS spectropolarimeter on Haleakala have provided system Mueller matrices over full telescope articulation for a 15-reflection coude system. AEOS and HiVIS are a DKIST analog with a many-fold coude optical feed and similar mirror coatings creating 100% polarization cross-talk with altitude, azimuth and wavelength. Polarization modeling predictions using Zemax have successfully matched the altitude-azimuth-wavelength dependence on HiVIS with the few percent amplitude limitations of several instrument artifacts. Polarization predictions for coude beam paths depend greatly on modeling the angle-of-incidence dependences in powered optics and the mirror coating formulations. A 6 month HiVIS daytime sky calibration plan has been analyzed for accuracy under a wide range of sky conditions and data analysis algorithms. Predictions of polarimetric performance for the DKIST first-light instrumentation suite have been created under a range of configurations. These new modeling tools and polarization predictions have substantial impact for the design, fabrication and calibration process in the presence of manufacturing issues, science use-case requirements and ultimate system calibration

  13. Predicting Visual Distraction Using Driving Performance Data

    PubMed Central

    Kircher, Katja; Ahlstrom, Christer

    2010-01-01

    Behavioral variables are often used as performance indicators (PIs) of visual or internal distraction induced by secondary tasks. The objective of this study is to investigate whether visual distraction can be predicted by driving performance PIs in a naturalistic setting. Visual distraction is here defined by a gaze based real-time distraction detection algorithm called AttenD. Seven drivers used an instrumented vehicle for one month each in a small scale field operational test. For each of the visual distraction events detected by AttenD, seven PIs such as steering wheel reversal rate and throttle hold were calculated. Corresponding data were also calculated for time periods during which the drivers were classified as attentive. For each PI, means between distracted and attentive states were calculated using t-tests for different time-window sizes (2 – 40 s), and the window width with the smallest resulting p-value was selected as optimal. Based on the optimized PIs, logistic regression was used to predict whether the drivers were attentive or distracted. The logistic regression resulted in predictions which were 76 % correct (sensitivity = 77 % and specificity = 76 %). The conclusion is that there is a relationship between behavioral variables and visual distraction, but the relationship is not strong enough to accurately predict visual driver distraction. Instead, behavioral PIs are probably best suited as complementary to eye tracking based algorithms in order to make them more accurate and robust. PMID:21050615

  14. Far field fallout prediction techniques. Doctoral thesis

    SciTech Connect

    Bigelow, W.S. Jr.

    1983-12-01

    A calculational technique for use in predicting fallout far downwind from nuclear bursts is developed and validated. Possible siting strategies for the next generation of missiles might invite a concentrated attack by thousands of nuclear warheads. The resulting fallout field could consist of the superposition of thousands of single burst patterns. The downwind extent of damaging radiation levels would extend beyond the distances to which calculations are usually performed for single bursts. Numerical models currently available cannot be extended to these large downwind distances because of the artificial pattern break up inherent in their numerical quadrature and because of prohibitive computing requirements. Two approaches to this problem are taken here. First, a numerical smoothing which conserves radioactivity is developed to help prevent pattern break up. This is partially successful in that it extends the predictive range farther downwind, but not far enough. The second approach is to abandon the numerical quadrature -- known as disc tossing -- and adopt a whole cloud smearing approach. The key function needed for the smearing approach, the fractional arrival rate of activity on the ground, is derived directly from physical principles and validated by comparison with an extensive series of numerical (disc tosser) predictions.

  15. Efficient prediction designs for random fields

    PubMed Central

    Müller, Werner G; Pronzato, Luc; Rendas, Joao; Waldl, Helmut

    2015-01-01

    For estimation and predictions of random fields, it is increasingly acknowledged that the kriging variance may be a poor representative of true uncertainty. Experimental designs based on more elaborate criteria that are appropriate for empirical kriging (EK) are then often non-space-filling and very costly to determine. In this paper, we investigate the possibility of using a compound criterion inspired by an equivalence theorem type relation to build designs quasi-optimal for the EK variance when space-filling designs become unsuitable. Two algorithms are proposed, one relying on stochastic optimization to explicitly identify the Pareto front, whereas the second uses the surrogate criteria as local heuristic to choose the points at which the (costly) true EK variance is effectively computed. We illustrate the performance of the algorithms presented on both a simple simulated example and a real oceanographic dataset. © 2014 The Authors. Applied Stochastic Models in Business and Industry published by John Wiley & Sons, Ltd. PMID:26300698

  16. The Real World Significance of Performance Prediction

    ERIC Educational Resources Information Center

    Pardos, Zachary A.; Wang, Qing Yang; Trivedi, Shubhendu

    2012-01-01

    In recent years, the educational data mining and user modeling communities have been aggressively introducing models for predicting student performance on external measures such as standardized tests as well as within-tutor performance. While these models have brought statistically reliable improvement to performance prediction, the real world…

  17. Microgravity Geyser and Flow Field Prediction

    NASA Technical Reports Server (NTRS)

    Hochstein, J. I.; Marchetta, J. G.; Thornton, R. J.

    2006-01-01

    Modeling and prediction of flow fields and geyser formation in microgravity cryogenic propellant tanks was investigated. A computational simulation was used to reproduce the test matrix of experimental results performed by other investigators, as well as to model the flows in a larger tank. An underprediction of geyser height by the model led to a sensitivity study to determine if variations in surface tension coefficient, contact angle, or jet pipe turbulence significantly influence the simulations. It was determined that computational geyser height is not sensitive to slight variations in any of these items. An existing empirical correlation based on dimensionless parameters was re-examined in an effort to improve the accuracy of geyser prediction. This resulted in the proposal for a re-formulation of two dimensionless parameters used in the correlation; the non-dimensional geyser height and the Bond number. It was concluded that the new non-dimensional geyser height shows little promise. Although further data will be required to make a definite judgement, the reformulation of the Bond number provided correlations that are more accurate and appear to be more general than the previously established correlation.

  18. Trends in reservoir performance prediction

    SciTech Connect

    Mackenzie, A.S.

    1994-12-31

    Stronger links between geoscience and petroleum engineering are being fostered by new tools and organizations. These linkages are improving the effectiveness of business decisions concerning reservoir performance, and are generating new challenges for the next generation of tools.

  19. Magnetic fields and scintillator performance

    SciTech Connect

    Green, D.; Ronzhin, A.; Hagopian, V.

    1995-06-01

    Experimental data have shown that the light output of a scintillator depends on the magnitude of the externally applied magnetic fields, and that this variation can affect the calorimeter calibration and possibly resolution. The goal of the measurements presented here is to study the light yield of scintillators in high magnetic fields in conditions that are similar to those anticipated for the LHC CMS detector. Two independent measurements were performed, the first at Fermilab and the second at the National High Magnetic Field Laboratory at Florida State University.

  20. Performance degradation in predicting topsoil organic carbon contents using reflectance spectra from lab, field to SPOT scales over a periurban region

    NASA Astrophysics Data System (ADS)

    Vaudour, E.; Gilliot, J. M.; Bel, L.; De Junet, A.; Michelin, J.; Hadjar, D.; Cambier, P.; Houot, S.; Coquet, Y.

    2012-04-01

    Within the framework of the French Gessol3 Programme (Prostock project), this study aims at comparing various observation scales for predicting topsoil organic carbon (SOC) content using Vis-NIR-SWIR reflectance spectra successively collected at the lab, in bare agricultural fields or extracted from atmospherically corrected multispectral SPOT images of very high (2.5 m) and medium low (20 m) spatial resolutions. The spatial coverage is that of a large periurban area (221 km2) characterized by cereal cropping systems and contrasting soil types. Considering either regional (entire periurban area) or local (a 6 ha-experimental field) scales, SOC contents were estimated from Partial Least Squares Regression (PLSR) modelling of lab and field spectra, for a number of latent variables comprised between 1 and 20. Regression robustness was evaluated through a series of 500-1000 bootstrapped datasets of calibration/validation samples generated amongst a total of 165 sampled sites. The optimal number of latent variables (BestComp) was chosen considering the lowest median validation Root Mean Square Error (RMSE) and for this BestComp, calibration/validation sets leading to minimum, median and maximum validation RMSE were considered. For satellite images, SOC contents were estimated from multiple linear (ML) modelling and the calibration/validation set leading to lowest calibration RMSE was selected for applying regression equation to the image pixels with bare soils. RMSE, bias and uncertainty were compared between the different models. At the regional scale, PLSR lab and field-based SOC models resulted in median validation RMSE values of ~3 g.kg-1and ~4 g.kg-1 respectively (≤0.95 g.kg-1 locally for lab-based models), while ML image-based SOC models resulted in median validation RMSE values between ~4-6.6 g.kg-1. Using an additional independent set of pixels with bare soils, ML models applied to the SPOT images were 'post-validated' resulting in validation RMSE values of ~4

  1. A nozzle internal performance prediction method

    NASA Technical Reports Server (NTRS)

    Carlson, John R.

    1992-01-01

    A prediction method was written and incorporated into a three-dimensional Navier-Stokes code (PAB3D) for the calculation of nozzle internal performance. The following quantities are calculated: (1) discharge coefficient; (2) normal, side, and axial thrust ratios; (3) rolling, pitching, and yawing moments; and (4) effective pitch and yaw vector angles. Four different case studies are presented to confirm the applicability of the methodology. Internal and, in most situations, external flow-field regions are required to be modeled. The computed nozzle discharge coefficient matches both the level and the trend of the experimental data within quoted experimental data accuracy (0.5 percent). Moment and force ratios are generally within 1 to 2 percent of the absolute level of experimental data, with the trends of data matched accurately.

  2. Program Predicts Performance of Optical Parametric Oscillators

    NASA Technical Reports Server (NTRS)

    Cross, Patricia L.; Bowers, Mark

    2006-01-01

    A computer program predicts the performances of solid-state lasers that operate at wavelengths from ultraviolet through mid-infrared and that comprise various combinations of stable and unstable resonators, optical parametric oscillators (OPOs), and sum-frequency generators (SFGs), including second-harmonic generators (SHGs). The input to the program describes the signal, idler, and pump beams; the SFG and OPO crystals; and the laser geometry. The program calculates the electric fields of the idler, pump, and output beams at three locations (inside the laser resonator, just outside the input mirror, and just outside the output mirror) as functions of time for the duration of the pump beam. For each beam, the electric field is used to calculate the fluence at the output mirror, plus summary parameters that include the centroid location, the radius of curvature of the wavefront leaving through the output mirror, the location and size of the beam waist, and a quantity known, variously, as a propagation constant or beam-quality factor. The program provides a typical Windows interface for entering data and selecting files. The program can include as many as six plot windows, each containing four graphs.

  3. The Prediction of Long-Term Coating Performance from Short-Term Electrochemical Data. Part 2; Comparison of Electrochemical Data to Field Exposure Results for Coatings on Steel

    NASA Technical Reports Server (NTRS)

    Contu, F.; Taylor, S. R.; Calle, L. M.; Hintze, P. E.; Curran, J. P.; Li, W.

    2009-01-01

    The pace of coatings development is limited by the time required to assess their corrosion protection properties. This study takes a step f orward from Part I in that it correlates the corrosion performance of organic coatings assessed by a series of short-term electrochemical measurement with 18-month beachside exposure results of duplicate pan els. A series of 19 coating systems on A36 steel substrates were test ed in a completely blind study using the damage tolerance test (DTT). In the DTT, a through-film pinhole defect is created, and the electro chemical characteristics of the defect are then monitored over the ne xt 4 to 7 days while immersed in 0.SM NaCl. The open circuit potentia l, anodic potentiostatic polarization tests and electrochemical imped ance spectroscopy were used to study the corrosion behavior of the co ating systems. The beachside exposure tests were conducted at the Ken nedy Space Center according to ASTM D610-01. It was found that for 79 % of the coatings systems examined, the 18 month beachside exposure r esults could be predicted by two independent laboratory tests obtained within 7 days.

  4. Evaluation testbed for ATD performance prediction (ETAPP)

    NASA Astrophysics Data System (ADS)

    Ralph, Scott K.; Eaton, Ross; Snorrason, Magnús; Irvine, John; Vanstone, Steve

    2007-04-01

    Automatic target detection (ATD) systems process imagery to detect and locate targets in imagery in support of a variety of military missions. Accurate prediction of ATD performance would assist in system design and trade studies, collection management, and mission planning. A need exists for ATD performance prediction based exclusively on information available from the imagery and its associated metadata. We present a predictor based on image measures quantifying the intrinsic ATD difficulty on an image. The modeling effort consists of two phases: a learning phase, where image measures are computed for a set of test images, the ATD performance is measured, and a prediction model is developed; and a second phase to test and validate performance prediction. The learning phase produces a mapping, valid across various ATR algorithms, which is even applicable when no image truth is available (e.g., when evaluating denied area imagery). The testbed has plug-in capability to allow rapid evaluation of new ATR algorithms. The image measures employed in the model include: statistics derived from a constant false alarm rate (CFAR) processor, the Power Spectrum Signature, and others. We present performance predictors for two trained ATD classifiers, one constructed using using GENIE Pro TM, a tool developed at Los Alamos National Laboratory, and the other eCognition TM, developed by Definiens (http://www.definiens.com/products). We present analyses of the two performance predictions, and compare the underlying prediction models. The paper concludes with a discussion of future research.

  5. Predictions of Performance in Career Education.

    ERIC Educational Resources Information Center

    Novick, M. R.; And Others

    Prediction weights for educational programs in 22 vocational and technical fields are provided using ability scores from the American College Testing Program (ACT) Career Planning Profile and a Bayesian regression theory. The criterion variable studies was first-semester grade-point average. Each vocational-technical program analyzed was…

  6. A statistical model for predicting muscle performance

    NASA Astrophysics Data System (ADS)

    Byerly, Diane Leslie De Caix

    The objective of these studies was to develop a capability for predicting muscle performance and fatigue to be utilized for both space- and ground-based applications. To develop this predictive model, healthy test subjects performed a defined, repetitive dynamic exercise to failure using a Lordex spinal machine. Throughout the exercise, surface electromyography (SEMG) data were collected from the erector spinae using a Mega Electronics ME3000 muscle tester and surface electrodes placed on both sides of the back muscle. These data were analyzed using a 5th order Autoregressive (AR) model and statistical regression analysis. It was determined that an AR derived parameter, the mean average magnitude of AR poles, significantly correlated with the maximum number of repetitions (designated Rmax) that a test subject was able to perform. Using the mean average magnitude of AR poles, a test subject's performance to failure could be predicted as early as the sixth repetition of the exercise. This predictive model has the potential to provide a basis for improving post-space flight recovery, monitoring muscle atrophy in astronauts and assessing the effectiveness of countermeasures, monitoring astronaut performance and fatigue during Extravehicular Activity (EVA) operations, providing pre-flight assessment of the ability of an EVA crewmember to perform a given task, improving the design of training protocols and simulations for strenuous International Space Station assembly EVA, and enabling EVA work task sequences to be planned enhancing astronaut performance and safety. Potential ground-based, medical applications of the predictive model include monitoring muscle deterioration and performance resulting from illness, establishing safety guidelines in the industry for repetitive tasks, monitoring the stages of rehabilitation for muscle-related injuries sustained in sports and accidents, and enhancing athletic performance through improved training protocols while reducing

  7. Experimental evaluation of radiosity for room sound-field prediction.

    PubMed

    Hodgson, Murray; Nosal, Eva-Marie

    2006-08-01

    An acoustical radiosity model was evaluated for how it performs in predicting real room sound fields. This was done by comparing radiosity predictions with experimental results for three existing rooms--a squash court, a classroom, and an office. Radiosity predictions were also compared with those by ray tracing--a "reference" prediction model--for both specular and diffuse surface reflection. Comparisons were made for detailed and discretized echograms, sound-decay curves, sound-propagation curves, and the variations with frequency of four room-acoustical parameters--EDT, RT, D50, and C80. In general, radiosity and diffuse ray tracing gave very similar predictions. Predictions by specular ray tracing were often very different. Radiosity agreed well with experiment in some cases, less well in others. Definitive conclusions regarding the accuracy with which the rooms were modeled, or the accuracy of the radiosity approach, were difficult to draw. The results suggest that radiosity predicts room sound fields with some accuracy, at least as well as diffuse ray tracing and, in general, better than specular ray tracing. The predictions of detailed echograms are less accurate, those of derived room-acoustical parameters more accurate. The results underline the need to develop experimental methods for accurately characterizing the absorptive and reflective characteristics of room surfaces, possible including phase. PMID:16938969

  8. High Performance Field Reversed Configurations

    NASA Astrophysics Data System (ADS)

    Binderbauer, Michl

    2014-10-01

    The field-reversed configuration (FRC) is a prolate compact toroid with poloidal magnetic fields. FRCs could lead to economic fusion reactors with high power density, simple geometry, natural divertor, ease of translation, and possibly capable of burning aneutronic fuels. However, as in other high-beta plasmas, there are stability and confinement concerns. These concerns can be addressed by introducing and maintaining a significant fast ion population in the system. This is the approach adopted by TAE and implemented for the first time in the C-2 device. Studying the physics of FRCs driven by Neutral Beam (NB) injection, significant improvements were made in confinement and stability. Early C-2 discharges had relatively good confinement, but global power losses exceeded the available NB input power. The addition of axially streaming plasma guns, magnetic end plugs as well as advanced surface conditioning leads to dramatic reductions in turbulence driven losses and greatly improved stability. As a result, fast ion confinement significantly improved and allowed for build-up of a dominant fast particle population. Under such appropriate conditions we achieved highly reproducible, long-lived, macroscopically stable FRCs with record lifetimes. This demonstrated many beneficial effects of large orbit particles and their performance impact on FRCs Together these achievements point to the prospect of beam-driven FRCs as a path toward fusion reactors. This presentation will review and expand on key results and present context for their interpretation.

  9. Performance Monitoring in Monkey Frontal Eye Field

    PubMed Central

    Yu, Dian; Ferrera, Vincent P.

    2014-01-01

    The frontal eye fields (FEF) are thought to mediate response selection during oculomotor decision tasks. In addition, many FEF neurons have robust postsaccadic responses, but their role in postchoice evaluative processes (online performance monitoring) is only beginning to become apparent. Here we report error-related neural activity in FEF while monkeys performed a biased speed-categorization task that enticed the animals to make impulsive errors. Twenty-three percent of cells in macaque FEF coded an internally generated error-related signal, and many of the same cells also coded task difficulty. The observed responses are primarily consistent with three related concepts that have been associated with performance monitoring: (1) response conflict; (2) uncertainty; and (3) reward prediction. Overall, our findings suggest a novel role for the FEF as part of the neural network that evaluates the preceding choice to optimize behavior in the future. PMID:24478349

  10. Predicting Language Performance in Hearing Impaired Children.

    ERIC Educational Resources Information Center

    Monsees, Edna K.

    The 2-year study evaluated the language performance of 69 hearing impaired, preschool children born following the rubella epidemic of the early 1960's in order to develop an instrument for objectively assessing language achievement and a predictive index of language achievement. Two language rating scales were developed which were tied to the…

  11. Why Do Spatial Abilities Predict Mathematical Performance?

    ERIC Educational Resources Information Center

    Tosto, Maria Grazia; Hanscombe, Ken B.; Haworth, Claire M. A.; Davis, Oliver S. P.; Petrill, Stephen A.; Dale, Philip S.; Malykh, Sergey; Plomin, Robert; Kovas, Yulia

    2014-01-01

    Spatial ability predicts performance in mathematics and eventual expertise in science, technology and engineering. Spatial skills have also been shown to rely on neuronal networks partially shared with mathematics. Understanding the nature of this association can inform educational practices and intervention for mathematical underperformance.…

  12. What predicts performance during clinical psychology training?

    PubMed Central

    Scior, Katrina; Bradley, Caroline E; Potts, Henry W W; Woolf, Katherine; de C Williams, Amanda C

    2014-01-01

    Objectives While the question of who is likely to be selected for clinical psychology training has been studied, evidence on performance during training is scant. This study explored data from seven consecutive intakes of the UK's largest clinical psychology training course, aiming to identify what factors predict better or poorer outcomes. Design Longitudinal cross-sectional study using prospective and retrospective data. Method Characteristics at application were analysed in relation to a range of in-course assessments for 274 trainee clinical psychologists who had completed or were in the final stage of their training. Results Trainees were diverse in age, pre-training experience, and academic performance at A-level (advanced level certificate required for university admission), but not in gender or ethnicity. Failure rates across the three performance domains (academic, clinical, research) were very low, suggesting that selection was successful in screening out less suitable candidates. Key predictors of good performance on the course were better A-levels and better degree class. Non-white students performed less well on two outcomes. Type and extent of pre-training clinical experience on outcomes had varied effects on outcome. Research supervisor ratings emerged as global indicators and predicted nearly all outcomes, but may have been biased as they were retrospective. Referee ratings predicted only one of the seven outcomes examined, and interview ratings predicted none of the outcomes. Conclusions Predicting who will do well or poorly in clinical psychology training is complex. Interview and referee ratings may well be successful in screening out unsuitable candidates, but appear to be a poor guide to performance on the course. Practitioner points While referee and selection interview ratings did not predict performance during training, they may be useful in screening out unsuitable candidates at the application stage High school final academic performance

  13. Predicting pavement distress in oil field areas

    SciTech Connect

    Mason, J.M.; Scullion, T.; Stampley, B.E.

    1984-05-01

    A study on oil field traffic characteristics was performed and a procedure was developed for assessing current and future effects of oil field truck traffic on surface-treated (stage construction type) pavements. A computer program calculates several types of pavement distress and serviceability parameters to evaluate pavement performance under various axle load repetitions. Stepwise regression analysis of 132 surface-treated pavement sections led to the development of individual distress equations for rutting, raveling, flushing, alligator cracking, patching, longitudinal and transverse cracking, and failures (potholes). The versatility of the program provides a means of anticipating early pavement failures due to increased axle load repetitions. The program also provides the basic framework for computing the effects of other ''special-use'' truck traffic demands.

  14. Predicting pavement distress in oil field areas

    SciTech Connect

    Mason, J.M.; Scullion, T.; Stampley, B.E.

    1983-05-01

    A study on oil field traffic characteristics was performed and a procedure was developed for assessing current and future effects of oil field truck traffic on surface-treated (stage construction type) pavements. A computer program calculates several types of pavement distress and serviceability parameters to evaluate pavement performance under various axle load repetitions. Stepwise regression analysis of 132 surface-treated pavement sections led to the development of individual distress equations for rutting, raveling, flushing, alligator cracking, patching, longitudinal and transverse cracking, and failures (potholes). The versatility of the program provides a means of anticipating early pavement failures due to increased axle load repetitions. The program also provides the basic framework for computing the effects of other ''special-use'' truck traffic demands.

  15. A decision-support tool to predict spray deposition of insecticides in commercial potato fields and its implications for their performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In conventional and most IPM programs, application of insecticides continues to be the most important responsive pest control tactic. For both immediate and long-term optimization and sustainability of insecticide applications, it is paramount to study the factors affecting the performance of insect...

  16. Performance optimization in electric field gradient focusing.

    PubMed

    Sun, Xuefei; Farnsworth, Paul B; Tolley, H Dennis; Warnick, Karl F; Woolley, Adam T; Lee, Milton L

    2009-01-01

    Electric field gradient focusing (EFGF) is a technique used to simultaneously separate and concentrate biomacromolecules, such as proteins, based on the opposing forces of an electric field gradient and a hydrodynamic flow. Recently, we reported EFGF devices fabricated completely from copolymers functionalized with poly(ethylene glycol), which display excellent resistance to protein adsorption. However, the previous devices did not provide the predicted linear electric field gradient and stable current. To improve performance, Tris-HCl buffer that was previously doped in the hydrogel was replaced with a phosphate buffer containing a salt (i.e., potassium chloride, KCl) with high mobility ions. The new devices exhibited stable current, good reproducibility, and a linear electric field distribution in agreement with the shaped gradient region design due to improved ion transport in the hydrogel. The field gradient was calculated based on theory to be approximately 5.76 V/cm(2) for R-phycoerythrin when the applied voltage was 500 V. The effect of EFGF separation channel dimensions was also investigated; a narrower focused band was achieved in a smaller diameter channel. The relationship between the bandwidth and channel diameter is consistent with theory. Three model proteins were resolved in an EFGF channel of this design. The improved device demonstrated 14,000-fold concentration of a protein sample (from 2 ng/mL to 27 microg/mL). PMID:19081099

  17. Computer Program Predicts Turbine-Stage Performance

    NASA Technical Reports Server (NTRS)

    Boyle, Robert J.; Haas, Jeffrey E.; Katsanis, Theodore

    1988-01-01

    MTSBL updated version of flow-analysis programs MERIDL and TSONIC coupled to boundary-layer program BLAYER. Method uses quasi-three-dimensional, inviscid, stream-function flow analysis iteratively coupled to calculated losses so changes in losses result in changes in flow distribution. Manner effects both configuration on flow distribution and flow distribution on losses taken into account in prediction of performance of stage. Written in FORTRAN IV.

  18. Performance predictions for the Keck telescope adaptive optics system

    SciTech Connect

    Gavel, D.T.; Olivier, S.S.

    1995-08-07

    The second Keck ten meter telescope (Keck-11) is slated to have an infrared-optimized adaptive optics system in the 1997--1998 time frame. This system will provide diffraction-limited images in the 1--3 micron region and the ability to use a diffraction-limited spectroscopy slit. The AO system is currently in the preliminary design phase and considerable analysis has been performed in order to predict its performance under various seeing conditions. In particular we have investigated the point-spread function, energy through a spectroscopy slit, crowded field contrast, object limiting magnitude, field of view, and sky coverage with natural and laser guide stars.

  19. IR system field performance with superresolution

    NASA Astrophysics Data System (ADS)

    Fanning, Jonathan; Miller, Justin; Park, Jennifer; Tener, Gene; Reynolds, Joseph; O'Shea, Patrick; Halford, Carl; Driggers, Ron

    2007-04-01

    Superresolution processing is currently being used to improve the performance of infrared imagers through an increase in sampling, the removal of aliasing, and the reduction of fixed-pattern noise. The performance improvement of superresolution has not been previously tested on military targets. This paper presents the results of human perception experiments to determine field performance on the NVESD standard military eight (8)-target set using a prototype LWIR camera. These experiments test and compare human performance of both still images and movie clips, each generated with and without superresolution processing. Lockheed Martin's XR® algorithm is tested as a specific example of a modern combined superresolution and image processing algorithm. Basic superresolution with no additional processing is tested to help determine the benefit of separate processes. The superresolution processing is modeled in NVThermIP for comparison to the perception test. The measured range to 70% probability of identification using XR® is increased by approximately 34% while the 50% range is increased by approximately 19% for this camera. A comparison case is modeled using a more undersampled commercial MWIR sensor that predicts a 45% increase in range performance from superresolution.

  20. Predicting sample size required for classification performance

    PubMed Central

    2012-01-01

    Background Supervised learning methods need annotated data in order to generate efficient models. Annotated data, however, is a relatively scarce resource and can be expensive to obtain. For both passive and active learning methods, there is a need to estimate the size of the annotated sample required to reach a performance target. Methods We designed and implemented a method that fits an inverse power law model to points of a given learning curve created using a small annotated training set. Fitting is carried out using nonlinear weighted least squares optimization. The fitted model is then used to predict the classifier's performance and confidence interval for larger sample sizes. For evaluation, the nonlinear weighted curve fitting method was applied to a set of learning curves generated using clinical text and waveform classification tasks with active and passive sampling methods, and predictions were validated using standard goodness of fit measures. As control we used an un-weighted fitting method. Results A total of 568 models were fitted and the model predictions were compared with the observed performances. Depending on the data set and sampling method, it took between 80 to 560 annotated samples to achieve mean average and root mean squared error below 0.01. Results also show that our weighted fitting method outperformed the baseline un-weighted method (p < 0.05). Conclusions This paper describes a simple and effective sample size prediction algorithm that conducts weighted fitting of learning curves. The algorithm outperformed an un-weighted algorithm described in previous literature. It can help researchers determine annotation sample size for supervised machine learning. PMID:22336388

  1. Developing a gas rocket performance prediction technique

    NASA Technical Reports Server (NTRS)

    Morgenthaler, J. H.; Moon, L. F.; Stepien, W. R.

    1974-01-01

    A simple, semi-empirical performance correlation/prediction technique applicable to gaseous and liquid propellant rocket engines is presented. Excellent correlations were attained for over 100 test firings by adjusting the computation of the gaseous mixing of an unreactive, coaxial jet using a correlation factor, F, which resulted in prediction of the experimental combustion efficiency for each firing. Static pressure, mean velocity and turbulence intensity in the developing region of non-reactive coaxial jets, typical of those of coaxial injector elements were determined. Detailed profiles were obtained at twelve axial locations (extending from the nozzle exit for a distance of five diameters) downstream from a single element of the Bell Aerospace H2/O2 19-element coaxial injector. These data are compared with analytical predictions made using both eddy viscosity and turbulence kinetic energy mixing models and available computer codes. Comparisons were disappointing, demonstrating the necessity of developing improved turbulence models and computational techniques before detailed predictions of practical coaxial free jet flows are attempted.

  2. Prediction of tilted capillary barrier performance

    SciTech Connect

    Webb, S.W.; McCord, J.T.; Dwyer, S.F.

    1997-04-01

    Capillary barriers, consisting of tilted fine-over-coarse layers under unsaturated conditions, have been suggested as landfill covers to divert water infiltration away from sensitive underground regions, especially for arid and semi-arid regions. The Hydrological Evaluation of Landfill Performance (HELP) computer code is an evaluation tool for landfill covers used by designers and regulators. HELP is a quasi-two-dimensional model that predicts moisture movement into and through the underground soil and waste layers. Processes modeled within HELP include precipitation, runoff, evapotranspiration, unsaturated vertical drainage, saturated lateral drainage, and leakage through liners. Unfortunately, multidimensional unsaturated flow phenomena that are necessary for evaluating tilted capillary barriers are not included in HELP. Differences between the predictions of the HELP and those from a multidimensional unsaturated flow code are presented to assess the two different approaches. Comparisons are presented for the landfill covers including capillary barrier configurations at the Alternative Landfill Cover Demonstration (ALCD) being conducted at Sandia.

  3. Hypersonic Interceptor Performance Evaluation Center aero-optics performance predictions

    NASA Astrophysics Data System (ADS)

    Sutton, George W.; Pond, John E.; Snow, Ronald; Hwang, Yanfang

    1993-06-01

    This paper describes the Hypersonic Interceptor Performance Evaluation Center's (HIPEC) aerooptics performance predictions capability. It includes code results for three dimensional shapes and comparisons to initial experiments. HIPEC consists of a collection of aerothermal, aerodynamic computational codes which are capable of covering the entire flight regime from subsonic to hypersonic flow and include chemical reactions and turbulence. Heat transfer to the various surfaces is calculated as an input to cooling and ablation processes. HIPEC also has aero-optics codes to determine the effect of the mean flowfield and turbulence on the tracking and imaging capability of on-board optical sensors. The paper concentrates on the latter aspects.

  4. Evaluating cotton stripper field performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton strippers are used primarily in the Southern High Plains due to the specific cotton varieties grown. Typically, cotton strippers cost about two-thirds the price of a cotton picker and range from one-half to one-fourth the horsepower. A cotton stripper also has a higher field and harvesting ef...

  5. Comparing theories' performance in predicting violence.

    PubMed

    Haas, Henriette; Cusson, Maurice

    2015-01-01

    The stakes of choosing the best theory as a basis for violence prevention and offender rehabilitation are high. However, no single theory of violence has ever been universally accepted by a majority of established researchers. Psychiatry, psychology and sociology are each subdivided into different schools relying upon different premises. All theories can produce empirical evidence for their validity, some of them stating the opposite of each other. Calculating different models with multivariate logistic regression on a dataset of N = 21,312 observations and ninety-two influences allowed a direct comparison of the performance of operationalizations of some of the most important schools. The psychopathology model ranked as the best model in terms of predicting violence right after the comprehensive interdisciplinary model. Next came the rational choice and lifestyle model and third the differential association and learning theory model. Other models namely the control theory model, the childhood-trauma model and the social conflict and reaction model turned out to have low sensitivities for predicting violence. Nevertheless, all models produced acceptable results in predictions of a non-violent outcome. PMID:25637261

  6. Texture metric that predicts target detection performance

    NASA Astrophysics Data System (ADS)

    Culpepper, Joanne B.

    2015-12-01

    Two texture metrics based on gray level co-occurrence error (GLCE) are used to predict probability of detection and mean search time. The two texture metrics are local clutter metrics and are based on the statistics of GLCE probability distributions. The degree of correlation between various clutter metrics and the target detection performance of the nine military vehicles in complex natural scenes found in the Search_2 dataset are presented. Comparison is also made between four other common clutter metrics found in the literature: root sum of squares, Doyle, statistical variance, and target structure similarity. The experimental results show that the GLCE energy metric is a better predictor of target detection performance when searching for targets in natural scenes than the other clutter metrics studied.

  7. Prediction of Gas Injection Performance for Heterogeneous Reservoirs

    SciTech Connect

    Franklin M. Orr, Jr; Martin J. Blunt

    1998-03-31

    This project performs research in four main areas: laboratory experiments to measure three-phase relative permeability; network modeling to predict three-phase relative perme- ability; benchmark simulations of gas injection and waterfl ooding at the field scale; and the development of fast streamline techniques to study field-scale oil. The aim of the work is to achieve a comprehensive description of gas injection processes from the pore to the core to the reservoir scale. In this report we provide a detailed description of our measurements of three-phase relative permeability.

  8. Machine characterization and benchmark performance prediction

    NASA Technical Reports Server (NTRS)

    Saavedra-Barrera, Rafael H.

    1988-01-01

    From runs of standard benchmarks or benchmark suites, it is not possible to characterize the machine nor to predict the run time of other benchmarks which have not been run. A new approach to benchmarking and machine characterization is reported. The creation and use of a machine analyzer is described, which measures the performance of a given machine on FORTRAN source language constructs. The machine analyzer yields a set of parameters which characterize the machine and spotlight its strong and weak points. Also described is a program analyzer, which analyzes FORTRAN programs and determines the frequency of execution of each of the same set of source language operations. It is then shown that by combining a machine characterization and a program characterization, we are able to predict with good accuracy the run time of a given benchmark on a given machine. Characterizations are provided for the Cray-X-MP/48, Cyber 205, IBM 3090/200, Amdahl 5840, Convex C-1, VAX 8600, VAX 11/785, VAX 11/780, SUN 3/50, and IBM RT-PC/125, and for the following benchmark programs or suites: Los Alamos (BMK8A1), Baskett, Linpack, Livermore Loops, Madelbrot Set, NAS Kernels, Shell Sort, Smith, Whetstone and Sieve of Erathostenes.

  9. Misleading performance in the supercomputing field

    NASA Technical Reports Server (NTRS)

    Bailey, David H.

    1992-01-01

    The problems of misleading performance reporting and the evident lack of careful refereeing in the supercomputing field are discussed in detail. Included are some examples that have appeared in recently published scientific papers. Some guidelines for reporting performance are presented the adoption of which would raise the level of professionalism and reduce the level of confusion in the field of supercomputing.

  10. Collective hormonal profiles predict group performance.

    PubMed

    Akinola, Modupe; Page-Gould, Elizabeth; Mehta, Pranjal H; Lu, Jackson G

    2016-08-30

    Prior research has shown that an individual's hormonal profile can influence the individual's social standing within a group. We introduce a different construct-a collective hormonal profile-which describes a group's hormonal make-up. We test whether a group's collective hormonal profile is related to its performance. Analysis of 370 individuals randomly assigned to work in 74 groups of three to six individuals revealed that group-level concentrations of testosterone and cortisol interact to predict a group's standing across groups. Groups with a collective hormonal profile characterized by high testosterone and low cortisol exhibited the highest performance. These collective hormonal level results remained reliable when controlling for personality traits and group-level variability in hormones. These findings support the hypothesis that groups with a biological propensity toward status pursuit (high testosterone) coupled with reduced stress-axis activity (low cortisol) engage in profit-maximizing decision-making. The current work extends the dual-hormone hypothesis to the collective level and provides a neurobiological perspective on the factors that determine who rises to the top across, not just within, social hierarchies. PMID:27528679

  11. Why do spatial abilities predict mathematical performance?

    PubMed

    Tosto, Maria Grazia; Hanscombe, Ken B; Haworth, Claire M A; Davis, Oliver S P; Petrill, Stephen A; Dale, Philip S; Malykh, Sergey; Plomin, Robert; Kovas, Yulia

    2014-05-01

    Spatial ability predicts performance in mathematics and eventual expertise in science, technology and engineering. Spatial skills have also been shown to rely on neuronal networks partially shared with mathematics. Understanding the nature of this association can inform educational practices and intervention for mathematical underperformance. Using data on two aspects of spatial ability and three domains of mathematical ability from 4174 pairs of 12-year-old twins, we examined the relative genetic and environmental contributions to variation in spatial ability and to its relationship with different aspects of mathematics. Environmental effects explained most of the variation in spatial ability (~70%) and in mathematical ability (~60%) at this age, and the effects were the same for boys and girls. Genetic factors explained about 60% of the observed relationship between spatial ability and mathematics, with a substantial portion of the relationship explained by common environmental influences (26% and 14% by shared and non-shared environments respectively). These findings call for further research aimed at identifying specific environmental mediators of the spatial-mathematics relationship. PMID:24410830

  12. Prediction of Gas Injection Performance for Heterogeneous Reservoirs

    SciTech Connect

    Blunt, Martin J.; Orr, Jr., Franklin M.

    1999-12-20

    This report describes research carried out in the Department of Petroleum Engineering at Stanford University from September 1998 - September 1998 under the third year of a three-year Department of Energy (DOE) grant on the ''Prediction of Gas Injection Performance for Heterogeneous Reservoirs''. The research effort is an integrated study of the factors affecting gas injection, from the pore scale to the field scale, and involves theoretical analysis, laboratory experiments and numerical simulation. The research is divided into four main areas: (1) Pore scale modeling of three-phase flow in porous media; (2) Laboratory experiments and analysis of factors influencing gas injection performance at the core scale with an emphasis on the fundamentals of three-phase flow; (3) Benchmark simulations of gas injection at the field scale; and (4) Development of streamline-based reservoir simulator.

  13. Changes in Memory Prediction Accuracy: Age and Performance Effects

    ERIC Educational Resources Information Center

    Pearman, Ann; Trujillo, Amanda

    2013-01-01

    Memory performance predictions are subjective estimates of possible memory task performance. The purpose of this study was to examine possible factors related to changes in word list performance predictions made by younger and older adults. Factors included memory self-efficacy, actual performance, and perceptions of performance. The current study…

  14. Performance of catalyzed hydrazine in field applications

    SciTech Connect

    Allgood, T.B.

    1987-01-01

    The performance of newly developed oxygen scavengers for boilers is often compared to sulfite and hydrazine. Catalyzed hydrazine out-performs hydrazine and might be preferred when catalyzed sulfite cannot be used. Data from a Midwest Utility confirms that, under field conditions, catalyzed hydrazine out-performance hydrazine and carbohydrazine when feedwater oxygen and iron levels were critical. Catalyzed hydrazine might be preferred when high performance and economics are the primary concerns.

  15. PREDICTION OF CHEMICAL RESIDUES IN AQUATIC ORGANISMS FOR A FIELD DISCHARGE SITUATION.

    EPA Science Inventory

    A field study was performed which compared predicted and measured concentrations of chemicals in receiving water organisms from three sampling locations on Five Mile Creek, Birmingham, Al. Two point source discharges, both from coke manufacturing facilities, were included in the ...

  16. Predicting vegetation-stabilized dune field morphology

    NASA Astrophysics Data System (ADS)

    Barchyn, Thomas E.; Hugenholtz, Chris H.

    2012-09-01

    The morphology of vegetation-stabilized dune fields on the North American Great Plains (NAGP) mostly comprises parabolic dunes; stabilized barchan and transverse dunes are rare, with the exception of transverse and barchan mega-dunes in the Nebraska Sand Hills. We present a hypothesis from a numerical dune field model explaining the vegetation-stabilized morphology of dunes under unidirectional wind. Simulations with a range of initial dune morphologies (closely-spaced transverse to disperse barchans) indicate that stabilized morphology is determined by the ratio of slipface deposition rate to deposition tolerance of vegetation. Slipface deposition rate is related to dune height, flux, and celerity. With a fixed depositional tolerance, large, slow-moving dunes have low slipface deposition rates and ‘freeze’ in place once vegetation is introduced. Relatively small, fast dunes have high slipface deposition rates and evolve into parabolic dunes, often colliding during stabilization. Our hypothesis could explain differences in stabilized morphology across the NAGP and elsewhere.

  17. Genomic Prediction of Testcross Performance in Canola (Brassica napus).

    PubMed

    Jan, Habib U; Abbadi, Amine; Lücke, Sophie; Nichols, Richard A; Snowdon, Rod J

    2016-01-01

    Genomic selection (GS) is a modern breeding approach where genome-wide single-nucleotide polymorphism (SNP) marker profiles are simultaneously used to estimate performance of untested genotypes. In this study, the potential of genomic selection methods to predict testcross performance for hybrid canola breeding was applied for various agronomic traits based on genome-wide marker profiles. A total of 475 genetically diverse spring-type canola pollinator lines were genotyped at 24,403 single-copy, genome-wide SNP loci. In parallel, the 950 F1 testcross combinations between the pollinators and two representative testers were evaluated for a number of important agronomic traits including seedling emergence, days to flowering, lodging, oil yield and seed yield along with essential seed quality characters including seed oil content and seed glucosinolate content. A ridge-regression best linear unbiased prediction (RR-BLUP) model was applied in combination with 500 cross-validations for each trait to predict testcross performance, both across the whole population as well as within individual subpopulations or clusters, based solely on SNP profiles. Subpopulations were determined using multidimensional scaling and K-means clustering. Genomic prediction accuracy across the whole population was highest for seed oil content (0.81) followed by oil yield (0.75) and lowest for seedling emergence (0.29). For seed yieId, seed glucosinolate, lodging resistance and days to onset of flowering (DTF), prediction accuracies were 0.45, 0.61, 0.39 and 0.56, respectively. Prediction accuracies could be increased for some traits by treating subpopulations separately; a strategy which only led to moderate improvements for some traits with low heritability, like seedling emergence. No useful or consistent increase in accuracy was obtained by inclusion of a population substructure covariate in the model. Testcross performance prediction using genome-wide SNP markers shows considerable

  18. Genomic Prediction of Testcross Performance in Canola (Brassica napus)

    PubMed Central

    Jan, Habib U.; Abbadi, Amine; Lücke, Sophie; Nichols, Richard A.; Snowdon, Rod J.

    2016-01-01

    Genomic selection (GS) is a modern breeding approach where genome-wide single-nucleotide polymorphism (SNP) marker profiles are simultaneously used to estimate performance of untested genotypes. In this study, the potential of genomic selection methods to predict testcross performance for hybrid canola breeding was applied for various agronomic traits based on genome-wide marker profiles. A total of 475 genetically diverse spring-type canola pollinator lines were genotyped at 24,403 single-copy, genome-wide SNP loci. In parallel, the 950 F1 testcross combinations between the pollinators and two representative testers were evaluated for a number of important agronomic traits including seedling emergence, days to flowering, lodging, oil yield and seed yield along with essential seed quality characters including seed oil content and seed glucosinolate content. A ridge-regression best linear unbiased prediction (RR-BLUP) model was applied in combination with 500 cross-validations for each trait to predict testcross performance, both across the whole population as well as within individual subpopulations or clusters, based solely on SNP profiles. Subpopulations were determined using multidimensional scaling and K-means clustering. Genomic prediction accuracy across the whole population was highest for seed oil content (0.81) followed by oil yield (0.75) and lowest for seedling emergence (0.29). For seed yieId, seed glucosinolate, lodging resistance and days to onset of flowering (DTF), prediction accuracies were 0.45, 0.61, 0.39 and 0.56, respectively. Prediction accuracies could be increased for some traits by treating subpopulations separately; a strategy which only led to moderate improvements for some traits with low heritability, like seedling emergence. No useful or consistent increase in accuracy was obtained by inclusion of a population substructure covariate in the model. Testcross performance prediction using genome-wide SNP markers shows considerable

  19. How Coriolis meter design affects field performance

    SciTech Connect

    Levien, A.; Dudiak, A.

    1995-12-31

    Although many possibilities exist for the design of Coriolis flowmeters, a common set of fundamental physical principles affect practical meter design. Design criteria such as tube geometry, alloy section, operating frequencies, stress levels, and tubing wall thickness have varying impacts on meter performance. Additionally, field conditions such as changing temperature, pressure, pipeline stress and vibration affect measurement performance. The challenge created in Coriolis flow meter design is to maximize the sensitivity of the meter Coriolis forces, while minimizing the impact of outside environmental influences. Data are presented on the physical principles that affect Coriolis flowmeters, and how the various aspects of meter design influence field performance.

  20. Predictions of H-mode performance in ITER

    SciTech Connect

    Budny, R. V.; Andre, R.; Bateman, G.; Halpern, F.; Kessel, C. E.; Kritz, A.; McCune, D.

    2008-03-03

    Time-dependent integrated predictive modeling is carried out using the PTRANSP code to predict fusion power and parameters such as alpha particle density and pressure in ITER H-mode plasmas. Auxiliary heating by negative ion neutral beam injection and ion cyclotron heating of He3 minority ions are modeled, and the GLF23 transport model is used in the prediction of the evolution of plasma temperature profiles. Effects of beam steering, beam torque, plasma rotation, beam current drive, pedestal temperatures, sawtooth oscillations, magnetic diffusion, and accumulation of He ash are treated self-consistently. Variations in assumptions associated with physics uncertainties for standard base-line DT H-mode plasmas (with Ip=15 MA, BTF=5.3 T, and Greenwald fraction=0.86) lead to a range of predictions for DT fusion power PDT and quasi-steady state fusion QDT (≡ PDT/Paux). Typical predictions assuming Paux = 50-53 MW yield PDT = 250- 720 MW and QDT = 5 - 14. In some cases where Paux is ramped down or shut off after initial flat-top conditions, quasi-steady QDT can be considerably higher, even infinite. Adverse physics assumptions such as existence of an inward pinch of the helium ash and an ash recycling coefficient approaching unity lead to very low values for PDT. Alternative scenarios with different heating and reduced performance regimes are also considered including plasmas with only H or D isotopes, DT plasmas with toroidal field reduced 10 or 20%, and discharges with reduced beam voltage. In full-performance D-only discharges, tritium burn-up is predicted to generate central tritium densities up to 1016/m3 and DT neutron rates up to 5×1016/s, compared with the DD neutron rates of 6×1017/s. Predictions with the toroidal field reduced 10 or 20% below the planned 5.3 T and keeping the same q98, Greenwald fraction, and Βη indicate that the fusion yield PDT and QDT will be lower by about a factor of two (scaling as B3.5).

  1. Misleading Performance Reporting in the Supercomputing Field

    NASA Technical Reports Server (NTRS)

    Bailey, David H.; Kutler, Paul (Technical Monitor)

    1992-01-01

    In a previous humorous note, I outlined twelve ways in which performance figures for scientific supercomputers can be distorted. In this paper, the problem of potentially misleading performance reporting is discussed in detail. Included are some examples that have appeared in recent published scientific papers. This paper also includes some proposed guidelines for reporting performance, the adoption of which would raise the level of professionalism and reduce the level of confusion in the field of supercomputing.

  2. Low thrust viscous nozzle flow fields prediction

    NASA Technical Reports Server (NTRS)

    Liaw, Goang-Shin

    1987-01-01

    An existing Navier-Stokes code (PARC2D) was used to compute the nozzle flow field. Grids were generated by the interactive grid generator codes TBGG and GENIE. All computations were made on the NASA/MSFC CRAY X-MP computer. Comparisons were made between the computations and MSFC in-house wall pressure measurements for CO2 flow through a conical nozzle having an area ratio of 40. Satisfactory agreements exist between the computations and measurements for different stagnation pressures of 29.4, 14.7, and 7.4 psia, at stagnation temperature of 1060 R. However, agreements did not match precisely near the nozzle exit. Several reasons for the lack of agreement are possible. The computational code assumes a constant gas gamma, whereas the gamma i.e. the specific heat ratio for CO2 varied from 1.22 in the plenum chamber to 1.38 at the nozzle exit. The computations also assumes adiabatic and no-slip walls. Both assumptions may not be correct. Finally, it is possible that condensation occurs during the nozzle expansion at the low stagnation pressure. The next phase of the work will incorporate variable gamma and slip wall boundary conditions in the computational code and develop a more accurate computer code.

  3. Predicting Students' Performance in Elements of Statistics

    ERIC Educational Resources Information Center

    Li, Kuiyuan; Uvah, Josaphat; Amin, Raid

    2012-01-01

    In this paper, we assess students' performance in Elements of Statistics, one of the popular courses in general education, using data from UWF (University of West Florida) for fall 2008, fall 2009, and fall 2010 semesters. We analyze associations between students' performance in the course and several performance related factors including: college…

  4. Free light fields can change the predictions of hybrid inflation

    SciTech Connect

    Matsuda, Tomohiro

    2012-04-01

    We show that the free light scalar fields that may exist in the inflationary Universe can change the predictions of the hybrid inflation model. Possible signatures are discussed, which can be used to discriminate the sources of the spectrum.

  5. Standard target sets for field sensor performance measurements

    NASA Astrophysics Data System (ADS)

    O'Connor, John D.; O'Shea, Patrick; Palmer, John E.; Deaver, Dawne M.

    2006-05-01

    The US Army Night Vision and Electronic Sensors Directorate (NVESD) Modeling and Simulation Division develops sensors models (FLIR 92, NV Therm, NV Therm IP) that predict the comparative performance of electro-optical sensors. The NVESD modeling branch developed a 12-vehicle, 12-aspect target signature set in 1998 with a known cycle criteria. It will be referred to as the 12-target set. This 12-target set has and will continue to be the modeling "gold standard" for laboratory human perception experiments supporting sensor performance modeling, and has been employed in dozens of published experiments. The 12-target set is, however, too costly for most acquisition field tests and evaluations. The authors developed an 8-vehicle 3-aspect target set, referred to as the 8- target set, and measured its discrimination task difficulty, (N50 and V50). Target identification (ID) range performance predictions for several sensors were made based on those V50/N50 values. A field collection of the 8-target set using those sensors provided imagery for a human perception study. The human perception study found excellent agreement between predicted and measured range performance. The goal of this development is to create a "silver standard" target set that is as dependable in measuring sensor performance as the "gold standard", and is affordable for Milestone A and other field trials.

  6. Predicting Death from Behavioral Test Performance

    ERIC Educational Resources Information Center

    Botwinick, Jack; And Others

    1978-01-01

    This study described several brief behavioral measures which, with further validation, could be useful in predicting the deaths of older adults within a five-year period following testing. Such tests can be used in routine biomedical examinations, alerting the physician to possible problems in the future. (Author)

  7. Prediction of Mechanical Properties of Polymers With Various Force Fields

    NASA Technical Reports Server (NTRS)

    Odegard, Gregory M.; Clancy, Thomas C.; Gates, Thomas S.

    2005-01-01

    The effect of force field type on the predicted elastic properties of a polyimide is examined using a multiscale modeling technique. Molecular Dynamics simulations are used to predict the atomic structure and elastic properties of the polymer by subjecting a representative volume element of the material to bulk and shear finite deformations. The elastic properties of the polyimide are determined using three force fields: AMBER, OPLS-AA, and MM3. The predicted values of Young s modulus and shear modulus of the polyimide are compared with experimental values. The results indicate that the mechanical properties of the polyimide predicted with the OPLS-AA force field most closely matched those from experiment. The results also indicate that while the complexity of the force field does not have a significant effect on the accuracy of predicted properties, small differences in the force constants and the functional form of individual terms in the force fields determine the accuracy of the force field in predicting the elastic properties of the polyimide.

  8. Prediction of Gas Injection Performance for Heterogeneous Reservoirs

    SciTech Connect

    Blunt, Martin J.; Orr, Franklin M.

    1999-05-17

    This report describes research carried out in the Department of Petroleum Engineering at Stanford University from September 1997 - September 1998 under the second year of a three-year grant from the Department of Energy on the "Prediction of Gas Injection Performance for Heterogeneous Reservoirs." The research effort is an integrated study of the factors affecting gas injection, from the pore scale to the field scale, and involves theoretical analysis, laboratory experiments, and numerical simulation. The original proposal described research in four areas: (1) Pore scale modeling of three phase flow in porous media; (2) Laboratory experiments and analysis of factors influencing gas injection performance at the core scale with an emphasis on the fundamentals of three phase flow; (3) Benchmark simulations of gas injection at the field scale; and (4) Development of streamline-based reservoir simulator. Each state of the research is planned to provide input and insight into the next stage, such that at the end we should have an integrated understanding of the key factors affecting field scale displacements.

  9. Rotary-wing aerodynamics. Volume 2: Performance prediction of helicopters

    NASA Technical Reports Server (NTRS)

    Keys, C. N.; Stephniewski, W. Z. (Editor)

    1979-01-01

    Application of theories, as well as, special methods of procedures applicable to performance prediction are illustrated first, on an example of the conventional helicopter and then, winged and tandem configurations. Performance prediction of conventional helicopters in hover and vertical ascent are investigated. Various approaches to performance prediction in forward translation are presented. Performance problems are discussed only this time, a wing is added to the baseline configuration, and both aircraft are compared with respect to their performance. This comparison is extended to a tandem. Appendices on methods for estimating performance guarantees and growth of aircraft concludes this volume.

  10. Germination and emergence tests for predicting switchgrass field establishment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of switchgrass (Panicum virgatum L.) seed quality tests on field establishment has not been addressed. Our objective was to evaluate the ability of seed quality tests to predict field establishment. Standard Association of Official Seed Analysts (AOSA) tests are based on the percentage of...

  11. Performance analysis and prediction in triathlon.

    PubMed

    Ofoghi, Bahadorreza; Zeleznikow, John; Macmahon, Clare; Rehula, Jan; Dwyer, Dan B

    2016-01-01

    Performance in triathlon is dependent upon factors that include somatotype, physiological capacity, technical proficiency and race strategy. Given the multidisciplinary nature of triathlon and the interaction between each of the three race components, the identification of target split times that can be used to inform the design of training plans and race pacing strategies is a complex task. The present study uses machine learning techniques to analyse a large database of performances in Olympic distance triathlons (2008-2012). The analysis reveals patterns of performance in five components of triathlon (three race "legs" and two transitions) and the complex relationships between performance in each component and overall performance in a race. The results provide three perspectives on the relationship between performance in each component of triathlon and the final placing in a race. These perspectives allow the identification of target split times that are required to achieve a certain final place in a race and the opportunity to make evidence-based decisions about race tactics in order to optimise performance. PMID:26177783

  12. Prediction of Ground Magnetic Field Fluctuations from Upstream Solar Wind

    NASA Astrophysics Data System (ADS)

    Weigel, R. S.; Vassiliadis, D.; Horton, W.; Klimas, A. J.

    2001-12-01

    A study of the predictability of temporal fluctuations in auroral--zone ground magnetic fields is presented. The fluctuation measure considered is the absolute value of the horizontal field time derivative (dH/dt) averaged over a 15--30~minute interval. This averaging time allows for a prediction lead time of approximately 30--45~minutes, depending on the solar wind speed. The fluctuation level is predicted using a neural network mapping of solar wind plasma and field data from the ACE satellite. Various solar wind inputs to the network are considered to determine which variables contain the most information, or drives, ground magnetic field fluctuations. The predictability of ground magnetic field fluctuations, which are responsible for ground induction currents (GICs), is shown to depend strongly on both local time and latitude. For some magnetometers, the predictability is found to be highest at local times that have the highest average fluctuation level and lowest at local times that have the lowest average fluctuation level. A maximum of 50% of the variability in a time series composed of 30~minute averages of |dH/dt| can be explained by the solar wind. When time delayed values of the fluctuation level at nearby magnetometer stations are included, up to 70% of of the variance in the |dH/dt| time series can be predicted.

  13. A predictive model of human performance.

    NASA Technical Reports Server (NTRS)

    Walters, R. F.; Carlson, L. D.

    1971-01-01

    An attempt is made to develop a model describing the overall responses of humans to exercise and environmental stresses for prediction of exhaustion vs an individual's physical characteristics. The principal components of the model are a steady state description of circulation and a dynamic description of thermal regulation. The circulatory portion of the system accepts changes in work load and oxygen pressure, while the thermal portion is influenced by external factors of ambient temperature, humidity and air movement, affecting skin blood flow. The operation of the model is discussed and its structural details are given.

  14. Field performance of a premium heating oil

    SciTech Connect

    Santa, T.; Jetter, S.

    1997-01-01

    As part of ongoing research to provide quality improvements to heating oil, Mobil Oil together with Santa Fuel conducted a field trial to investigate the performance of a new premium heating oil. This premium heating oil contains an additive system designed to minimize sludge related problems in the fuel delivery system of residential home heating systems. The additive used was similar to others reported at this and earlier BNL conferences, but was further developed to enhance its performance in oil heat systems. The premium heating oil was bulk additized and delivered to a subset of the customer base. The performance of this premium heating oil is discussed.

  15. Statistical validation of event predictors: A comparative study based on the field of seizure prediction

    SciTech Connect

    Feldwisch-Drentrup, Hinnerk; Schulze-Bonhage, Andreas; Timmer, Jens; Schelter, Bjoern

    2011-06-15

    The prediction of events is of substantial interest in many research areas. To evaluate the performance of prediction methods, the statistical validation of these methods is of utmost importance. Here, we compare an analytical validation method to numerical approaches that are based on Monte Carlo simulations. The comparison is performed in the field of the prediction of epileptic seizures. In contrast to the analytical validation method, we found that for numerical validation methods insufficient but realistic sample sizes can lead to invalid high rates of false positive conclusions. Hence we outline necessary preconditions for sound statistical tests on above chance predictions.

  16. Analysis of factors that predict clinical performance in medical school.

    PubMed

    White, Casey B; Dey, Eric L; Fantone, Joseph C

    2009-10-01

    Academic achievement indices including GPAs and MCAT scores are used to predict the spectrum of medical student academic performance types. However, use of these measures ignores two changes influencing medical school admissions: student diversity and affirmative action, and an increased focus on communication skills. To determine if GPA and MCAT predict performance in medical school consistently across students, and whether either predicts clinical performance in clerkships. A path model was developed to examine relationships among indices of medical student performance during the first three years of medical school for five cohorts of medical students. A structural equation approach was used to calculate the coefficients hypothesized in the model for majority and minority students. Significant differences between majority and minority students were observed. MCAT scores, for example, did not predict performance of minority students in the first year of medical school but did predict performance of majority students. This information may be of use to medical school admissions and resident selection committees. PMID:18030590

  17. Challenges of Student Selection: Predicting Academic Performance

    ERIC Educational Resources Information Center

    van der Merwe, D.; de Beer, M.

    2006-01-01

    Finding accurate predictors of tertiary academic performance, specifically for disadvantaged students, is essential because of budget constraints and the need of the labour market to address employment equity. Increased retention, throughput and decreased dropout rates are vital. When making admission decisions, the under preparedness of students…

  18. Predicting ICME Magnetic Fields with a Numerical Flux Rope Model

    NASA Astrophysics Data System (ADS)

    Manchester, W.; van der Holst, B.; Sokolov, I.

    2014-12-01

    Coronal mass ejections (CMEs) are a dramatic manifestation of solar activity that release vast amounts of plasma into the heliosphere, and have many effects on the interplanetary medium and on planetary atmospheres, and are the major driver of space weather. CMEs occur with the formation and expulsion of large-scale flux ropes from the solar corona, which are routinely observed in interplanetary space. Simulating and predicting the structure and dynamics of these ICME magnetic fields is essential to the progress of heliospheric science and space weather prediction. We combine observations made by different observing techniques of CME events to develop a numerical model capable of predicting the magnetic field of interplanetary coronal mass ejections (ICMES). Photospheric magnetic field measurements from SOHO/MDI and SDO/HMI are used to specify a coronal magnetic flux rope that drives the CMEs. We examine halo CMEs events that produced clearly observed magnetic clouds at Earth and present our model predictions of these events with an emphasis placed on the z component of the magnetic field. Comparison of the MHD model predictions with coronagraph observations and in-situ data allow us to robustly determine the parameters that define the initial state of the driving flux rope, thus providing a predictive model.

  19. Third Graders' Performance Predictions: Calibration Deflections and Academic Success

    ERIC Educational Resources Information Center

    Ots, Aivar

    2013-01-01

    This study focuses on third grade pupils' (9 to 10 years old) ability to predict their performance in a given task and on the correspondence between the accuracy and adequacy of the predictions on the one hand, and the academic achievement on the other. The study involved 713 pupils from 29 Estonian schools. The pupils' performance predictions…

  20. Does finger sense predict addition performance?

    PubMed

    Newman, Sharlene D

    2016-05-01

    The impact of fingers on numerical and mathematical cognition has received a great deal of attention recently. However, the precise role that fingers play in numerical cognition is unknown. The current study explores the relationship between finger sense, arithmetic and general cognitive ability. Seventy-six children between the ages of 5 and 12 participated in the study. The results of stepwise multiple regression analyses demonstrated that while general cognitive ability including language processing was a predictor of addition performance, finger sense was not. The impact of age on the relationship between finger sense, and addition was further examined. The participants were separated into two groups based on age. The results showed that finger gnosia score impacted addition performance in the older group but not the younger group. These results appear to support the hypothesis that fingers provide a scaffold for calculation and that if that scaffold is not properly built, it has continued differential consequences to mathematical cognition. PMID:26993292

  1. Performance evaluation of infrared imaging system in field test

    NASA Astrophysics Data System (ADS)

    Wang, Chensheng; Guo, Xiaodong; Ren, Tingting; Zhang, Zhi-jie

    2014-11-01

    Infrared imaging system has been applied widely in both military and civilian fields. Since the infrared imager has various types and different parameters, for system manufacturers and customers, there is great demand for evaluating the performance of IR imaging systems with a standard tool or platform. Since the first generation IR imager was developed, the standard method to assess the performance has been the MRTD or related improved methods which are not perfect adaptable for current linear scanning imager or 2D staring imager based on FPA detector. For this problem, this paper describes an evaluation method based on the triangular orientation discrimination metric which is considered as the effective and emerging method to evaluate the synthesis performance of EO system. To realize the evaluation in field test, an experiment instrument is developed. And considering the importance of operational environment, the field test is carried in practical atmospheric environment. The test imagers include panoramic imaging system and staring imaging systems with different optics and detectors parameters (both cooled and uncooled). After showing the instrument and experiment setup, the experiment results are shown. The target range performance is analyzed and discussed. In data analysis part, the article gives the range prediction values obtained from TOD method, MRTD method and practical experiment, and shows the analysis and results discussion. The experimental results prove the effectiveness of this evaluation tool, and it can be taken as a platform to give the uniform performance prediction reference.

  2. Mining Behavior Based Safety Data to Predict Safety Performance

    SciTech Connect

    Jeffrey C. Joe

    2010-06-01

    The Idaho National Laboratory (INL) operates a behavior based safety program called Safety Observations Achieve Results (SOAR). This peer-to-peer observation program encourages employees to perform in-field observations of each other's work practices and habits (i.e., behaviors). The underlying premise of conducting these observations is that more serious accidents are prevented from occurring because lower level “at risk” behaviors are identified and corrected before they can propagate into culturally accepted “unsafe” behaviors that result in injuries or fatalities. Although the approach increases employee involvement in safety, the premise of the program has not been subject to sufficient empirical evaluation. The INL now has a significant amount of SOAR data on these lower level “at risk” behaviors. This paper describes the use of data mining techniques to analyze these data to determine whether they can predict if and when a more serious accident will occur.

  3. Predicting performance of annual safety outcomes.

    PubMed

    Guria, J; Mara, K

    2001-05-01

    A control chart system was developed in an earlier paper to identify the occurrence of actual risk changes or deviation from the expected levels of road crash fatalities during the course of a year. This paper discusses the development of a prediction method for estimating number of fatalities during a year. The method then provides a mechanism for estimating the likelihood of meeting a pre-set target or any other outcome. At any point of time in a year, the attainability of a target for the year, depends not only on safety outcomes during the remainder of the year but also on outcomes up to that point in the year. High week to week variability would indicate that it can be difficult to achieve the intended maximum goal. The control charts developed earlier, indicate if the current trend differs from the expected trend or that required to achieve the target. This paper determines the probability of achieving the target given the past outcomes of the year. It also determines the level of outcome for the year based on the past trend and in the absence of any special programmes. The paper discusses the New Zealand application as an example. PMID:11235800

  4. Driving and Low Vision: Validity of Assessments for Predicting Performance of Drivers

    ERIC Educational Resources Information Center

    Strong, J. Graham; Jutai, Jeffrey W.; Russell-Minda, Elizabeth; Evans, Mal

    2008-01-01

    The authors conducted a systematic review to examine whether vision-related assessments can predict the driving performance of individuals who have low vision. The results indicate that measures of visual field, contrast sensitivity, cognitive and attention-based tests, and driver screening tools have variable utility for predicting real-world…

  5. Rotary atomizers - Performance understanding and prediction

    NASA Astrophysics Data System (ADS)

    Matsumoto, S.; Belcher, D. W.; Crosby, E. J.

    The general design features of commercial rotary atomizers used in the chemical process industries are reviewed relative to application and performance requirements. Desired knowledge about atomizer design and spray-cloud characteristics are summarized and compared to available information. The status of understanding based on analysis and experimentation is surveyed. Generally unconsidered aspects of flow within the atomizer body, disengagement from the atomizer periphery, spray cloud configuration, degree of atomization and feedstock properties are discussed. Certain phenomena related to the atomization of multiphase feedstocks are noted.

  6. Law school performance predicted by explanatory style.

    PubMed

    Satterfield, J M; Monahan, J; Seligman, M E

    1997-01-01

    The explanatory styles of 387 law students were assessed prior to law school using the Attributional Style Questionnaire (ASQ). Longitudinal performance measures were collected throughout law school and related to each student's initial explanatory style. In contrast to studies with undergraduates, students who made stable, global, and internal attributions for negative events combined with the converse attributions for success (typically called pessimists) outperformed more optimistic students on measures of grade point averages and law journal success. We discuss the limitations of current attributional research methodologies and suggest the prudent and cautious perspective necessary for law or skill-based professions may account for our findings. PMID:9160992

  7. Predicted thermal performance of triple vacuum glazing

    SciTech Connect

    Fang, Yueping; Hyde, Trevor J.; Hewitt, Neil

    2010-12-15

    The simulated triple vacuum glazing (TVG) consists of three 4 mm thick glass panes with two vacuum gaps, with each internal glass surface coated with a low-emittance coating with an emittance of 0.03. The two vacuum gaps are sealed by an indium based sealant and separated by a stainless steel pillar array with a height of 0.12 mm and a pillar diameter of 0.3 mm spaced at 25 mm. The thermal transmission at the centre-of-glazing area of the TVG was predicted to be 0.26 W m{sup -2} K{sup -1}. The simulation results show that although the thermal conductivity of solder glass (1 W m{sup -1} K{sup -1}) and indium (83.7 W m{sup -1} K{sup -1}) are very different, the difference in thermal transmission of TVGs resulting from the use of an indium and a solder glass edge seal was 0.01 W m{sup -2} K{sup -1}. This is because the edge seal is so thin (0.12 mm), consequently there is a negligible temperature drop across it irrespective of the material that the seal is made from relative to the total temperature difference across the glazing. The results also show that there is a relatively large increase in the overall thermal conductance of glazings without a frame when the width of the indium edge seal is increased. Increasing the rebate depth in a solid wood frame decreased the heat transmission of the TVG. The overall heat transmission of the simulated 0.5 m by 0.5 m TVG was 32.6% greater than that of the 1 m by 1 m TVG, since heat conduction through the edge seal of the small glazing has a larger contribution to the total glazing heat transfer than that of the larger glazing system. (author)

  8. Predicting unit performance by assessing transformational and transactional leadership.

    PubMed

    Bass, Bernard M; Avolio, Bruce J; Jung, Dong I; Berson, Yair

    2003-04-01

    How do leadership ratings collected from units operating under stable conditions predict subsequent performance of those units operating under high stress and uncertainty? To examine this question, the authors calculated the predictive relationships for the transformational and transactional leadership of 72 light infantry rifle platoon leaders for ratings of unit potency, cohesion, and performance for U.S. Army platoons participating in combat simulation exercises. Both transformational and transactional contingent reward leadership ratings of platoon leaders and sergeants positively predicted unit performance. The relationship of platoon leadership to performance was partially mediated through the unit's level of potency and cohesion. Implications, limitations, and future directions for leadership research are discussed. PMID:12731705

  9. Does IQ Really Predict Job Performance?

    PubMed Central

    Richardson, Ken; Norgate, Sarah H.

    2015-01-01

    IQ has played a prominent part in developmental and adult psychology for decades. In the absence of a clear theoretical model of internal cognitive functions, however, construct validity for IQ tests has always been difficult to establish. Test validity, therefore, has always been indirect, by correlating individual differences in test scores with what are assumed to be other criteria of intelligence. Job performance has, for several reasons, been one such criterion. Correlations of around 0.5 have been regularly cited as evidence of test validity, and as justification for the use of the tests in developmental studies, in educational and occupational selection and in research programs on sources of individual differences. Here, those correlations are examined together with the quality of the original data and the many corrections needed to arrive at them. It is concluded that considerable caution needs to be exercised in citing such correlations for test validation purposes. PMID:26405429

  10. Cruise performance and range prediction reconsidered

    NASA Astrophysics Data System (ADS)

    Torenbeek, Egbert

    1997-05-01

    A unified analytical treatment of the cruise performance of subsonic transport aircraft is derived, valid for gas turbine powerplant installations: turboprop, turbojet and turbofan powered aircraft. Different from the classical treatment the present article deals with compressibility effects on the aerodynamic characteristics. Analytical criteria are derived for optimum cruise lift coefficient and Mach number, with and without constraints on the altitude and engine rating. A simple alternative to the Bréguet range equation is presented which applies to several practical cruising flight techniques: flight at constant altitude and Mach number and stepped cruise/climb. A practical non-iterative procedure for computing mission and reserve fuel loads in the preliminary design stage is proposed.

  11. Reliable predictions of waste performance in a geologic repository

    SciTech Connect

    Pigford, T.H.; Chambre, P.L.

    1985-08-01

    Establishing reliable estimates of long-term performance of a waste repository requires emphasis upon valid theories to predict performance. Predicting rates that radionuclides are released from waste packages cannot rest upon empirical extrapolations of laboratory leach data. Reliable predictions can be based on simple bounding theoretical models, such as solubility-limited bulk-flow, if the assumed parameters are reliably known or defensibly conservative. Wherever possible, performance analysis should proceed beyond simple bounding calculations to obtain more realistic - and usually more favorable - estimates of expected performance. Desire for greater realism must be balanced against increasing uncertainties in prediction and loss of reliability. Theoretical predictions of release rate based on mass-transfer analysis are bounding and the theory can be verified. Postulated repository analogues to simulate laboratory leach experiments introduce arbitrary and fictitious repository parameters and are shown not to agree with well-established theory. 34 refs., 3 figs., 2 tabs.

  12. Performance Reports: Mirror alignment system performance prediction comparison between SAO and EKC

    NASA Technical Reports Server (NTRS)

    Tananbaum, H. D.; Zhang, J. P.

    1994-01-01

    The objective of this study is to perform an independent analysis of the residual high resolution mirror assembly (HRMA) mirror distortions caused by force and moment errors in the mirror alignment system (MAS) to statistically predict the HRMA performance. These performance predictions are then compared with those performed by Kodak to verify their analysis results.

  13. Evaluation of Turbulence Models Performance in Predicting Incipient Cavitation in an Enlarged Step-Nozzle

    NASA Astrophysics Data System (ADS)

    Naseri, H.; Koukouvinis, P.; Gavaises, M.

    2015-12-01

    Predictive capability of RANS and LES models to calculate incipient cavitation of water in a step nozzle is assessed. The RANS models namely, Realizable k-ε, SST k-ω and Reynolds Stress Model did not predict any cavitation, due to the limitation of RANS models to predict the low pressure vortex cores. LES WALE model was able to predict the cavitation by capturing the shear layer instability and vortex shedding. The performance of a barotropic cavitation model and Rayleigh-Plesset-based cavitation models was compared using WALE model. Although the phase change formulation is different in these models, the predicted cavitation and flow field were not significantly different.

  14. Predictions and experiments of the VAWT viscous flow field. [Vertical Axis Wind Turbine

    SciTech Connect

    Paraschivoiu, I.; Rajagopalan, R.G.; Masson, C.

    1987-06-01

    The first objective of the work was to compare the aerodynamic loads and performance predicted by the double-multiple-streamtube model with the viscous-flow-field analysis of a vertical-axis wind turbine. Second, to check the validity of the two performance/load models, their predictions were compared with available experimental data. When the dynamic effects at low tip-speed ratios (dynamic stall) and added mass and circulatory effects at high tip-speed ratios were included, significant improvement was obtained in the prediction of the aerodynamic characteristics of the turbine, such as induced velocities and instantaneous blade forces. 11 references.

  15. Technique for Predicting the RF Field Strength Inside an Enclosure

    NASA Technical Reports Server (NTRS)

    Hallett, M.; Reddell, J.

    1998-01-01

    This Memorandum presents a simple analytical technique for predicting the RF electric field strength inside an enclosed volume in which radio frequency radiation occurs. The technique was developed to predict the radio frequency (RF) field strength within a launch vehicle's fairing from payloads launched with their telemetry transmitters radiating and to the impact of the radiation on the vehicle and payload. The RF field strength is shown to be a function of the surface materials and surface areas. The method accounts for RF energy losses within exposed surfaces, through RF windows, and within multiple layers of dielectric materials which may cover the surfaces. This Memorandum includes the rigorous derivation of all equations and presents examples and data to support the validity of the technique.

  16. Well performance graph simplifies field calculations

    SciTech Connect

    De Ghetto, G.

    1987-05-01

    Graphic Methods are widely employed in order to understand overall well behavior using only surface parameters. The authors propose a new graphic method, used successfully by Agip for oil and gas wells in Italy, Libya, Nigeria and Tunisia. The well performance graph helps solve many production problems, including estimation of: inflow performance relationship; causes of rate decline throughout well life; and production rate and bottomhole flowing pressure for various pressures upstream of the surface choke, and vice-versa. This method differs from others by using flow behavior through the choke for both critical and subcritical conditions. Equations describing flow through the formation, string and surface choke are also used. Results are quite reliable when these theoretical equations are calibrated with field data, either from the well concerned or from nearby wells producing the same fluid. This article describes the technique as it applies to oil wells. The methodology for gas wells is similar.

  17. Predicting Test Performance: A Content Valid Approach to Screening Applicants.

    ERIC Educational Resources Information Center

    Pannone, Ronald D.

    1984-01-01

    Examined the validity of a rationally developed biographical questionnaire for predicting content valid test performance for electrician applicants (N=221). Results showed that the utility of the questionnaire in screening applicant populations was both statistically and practically significant. (LLL)

  18. Prediction of Student Performance Through Pretesting in Food and Nutrition

    ERIC Educational Resources Information Center

    Carruth, Betty Ruth; Lamb, Mina W.

    1971-01-01

    Attempts to develop an objective pretest for identifying students' levels of knowledge in food and nutrition prior to class instruction and for predicting student performance on the final examination. (Editor/MU)

  19. An Approach to Performance Prediction for Parallel Applications

    SciTech Connect

    Ipek, E; de Supinski, B R; Schulz, M; McKee, S A

    2005-05-17

    Accurately modeling and predicting performance for large-scale applications becomes increasingly difficult as system complexity scales dramatically. Analytic predictive models are useful, but are difficult to construct, usually limited in scope, and often fail to capture subtle interactions between architecture and software. In contrast, we employ multilayer neural networks trained on input data from executions on the target platform. This approach is useful for predicting many aspects of performance, and it captures full system complexity. Our models are developed automatically from the training input set, avoiding the difficult and potentially error-prone process required to develop analytic models. This study focuses on the high-performance, parallel application SMG2000, a much studied code whose variations in execution times are still not well understood. Our model predicts performance on two large-scale parallel platforms within 5%-7% error across a large, multi-dimensional parameter space.

  20. An Activity for Predicting Performances in the 1984 Summer Olympics.

    ERIC Educational Resources Information Center

    Henningsen, Jacqueline

    1984-01-01

    Techniques that students can use to make predictions about performances in the Olympics include point estimation. This is used to estimate a single value using a set of data. A worksheet for students is included. (MNS)

  1. Predicted NETD performance of a polarized infrared imaging sensor

    NASA Astrophysics Data System (ADS)

    Preece, Bradley; Hodgkin, Van A.; Thompson, Roger; Leonard, Kevin; Krapels, Keith

    2014-05-01

    Polarization filters are commonly used as a means of increasing the contrast of a scene thereby increasing sensor range performance. The change in the signal to noise ratio (SNR) is a function of the polarization of the target and background, the type and orientation of the polarization filter(s), and the overall transparency of the filter. However, in the mid-wave and longwave infrared bands (MWIR and LWIR), the noise equivalent temperature difference (NETD), which directly affects the SNR, is a function of the filter's re-emission and its reflected temperature radiance. This paper presents a model, by means of a Stokes vector input, that can be incorporated into the Night Vision Integrated Performance Model (NV-IPM) in order to predict the change in SNR, NETD, and noise equivalent irradiance (NEI) for infrared polarimeter imaging systems. The model is then used to conduct a SNR trade study, using a modeled Stokes vector input, for a notional system looking at a reference target. Future laboratory and field measurements conducted at Night Vision Electronic Sensors Directorate (NVESD) will be used to update, validate, and mature the model of conventional infrared systems equipped with polarization filters.

  2. A non-geometrically similar model for predicting the wake field of full-scale ships

    NASA Astrophysics Data System (ADS)

    Guo, Chunyu; Zhang, Qi; Shen, Yu

    2015-07-01

    The scale effect leads to large discrepancies between the wake fields of model-scale and actual ships, and causes differences in cavitation performance and exciting forces tests in predicting the performance of actual ships. Therefore, when test data from ship models are directly applied to predict the performance of actual ships, test results must be subjected to empirical corrections. This study proposes a method for the reverse design of the hull model. Compared to a geometrically similar hull model, the wake field generated by the modified model is closer to that of an actual ship. A non- geometrically similar model of a Korean Research Institute of Ship and Ocean Engineering (KRISO)'s container ship (KCS) was designed. Numerical simulations were performed using this model, and its results were compared with full-scale calculation results. The deformation method of getting the wake field of full-scale ships by the non-geometrically similar model is applied to the KCS successfully.

  3. Dual-stroke heat pump field performance

    NASA Astrophysics Data System (ADS)

    Veyo, S. E.

    1984-11-01

    Two nearly identical proprototype systems, each employing a unique dual-stroke compressor, were built and tested. One was installed in an occupied residence in Jeannette, Pa. It has provided the heating and cooling required from that time to the present. The system has functioned without failure of any prototypical advanced components, although early field experience did suffer from deficiencies in the software for the breadboard micro processor control system. Analysis of field performance data indicates a heating performance factor (HSPF) of 8.13 Stu/Wa, and a cooling energy efficiency (SEER) of 8.35 Scu/Wh. Data indicate that the beat pump is oversized for the test house since the observed lower balance point is 3 F whereas 17 F La optimum. Oversizing coupled with the use of resistance heat ot maintain delivered air temperature warmer than 90 F results in the consumption of more resistance heat than expected, more unit cycling, and therefore lower than expected energy efficiency. Our analysis indicates that with optimal mixing the dual stroke heat pump will yield as HSFF 30% better than a single capacity heat pump representative of high efficiency units in the market place today for the observed weather profile.

  4. COMPASS: A Framework for Automated Performance Modeling and Prediction

    SciTech Connect

    Lee, Seyong; Meredith, Jeremy S; Vetter, Jeffrey S

    2015-01-01

    Flexible, accurate performance predictions offer numerous benefits such as gaining insight into and optimizing applications and architectures. However, the development and evaluation of such performance predictions has been a major research challenge, due to the architectural complexities. To address this challenge, we have designed and implemented a prototype system, named COMPASS, for automated performance model generation and prediction. COMPASS generates a structured performance model from the target application's source code using automated static analysis, and then, it evaluates this model using various performance prediction techniques. As we demonstrate on several applications, the results of these predictions can be used for a variety of purposes, such as design space exploration, identifying performance tradeoffs for applications, and understanding sensitivities of important parameters. COMPASS can generate these predictions across several types of applications from traditional, sequential CPU applications to GPU-based, heterogeneous, parallel applications. Our empirical evaluation demonstrates a maximum overhead of 4%, flexibility to generate models for 9 applications, speed, ease of creation, and very low relative errors across a diverse set of architectures.

  5. The joint effects of personality and workplace social exchange relationships in predicting task performance and citizenship performance.

    PubMed

    Kamdar, Dishan; Van Dyne, Linn

    2007-09-01

    This field study examines the joint effects of social exchange relationships at work (leader-member exchange and team-member exchange) and employee personality (conscientiousness and agreeableness) in predicting task performance and citizenship performance. Consistent with trait activation theory, matched data on 230 employees, their coworkers, and their supervisors demonstrated interactions in which high quality social exchange relationships weakened the positive relationships between personality and performance. Results demonstrate the benefits of consonant predictions in which predictors and outcomes are matched on the basis of specific targets. We discuss theoretical and practical implications. PMID:17845086

  6. Predicting dynamic performance limits for servosystems with saturating nonlinearities

    NASA Technical Reports Server (NTRS)

    Webb, J. A., Jr.; Blech, R. A.

    1979-01-01

    A generalized treatment for a system with a single saturating nonlinearity is presented and compared with frequency response plots obtained from an analog model of the system. Once the amplitude dynamics are predicted with the limit lines, an iterative technique is employed to determine the system phase response. The saturation limit line technique is used in conjunction with velocity and acceleration limits to predict the performance of an electro-hydraulic servosystem containing a single-stage servovalve. Good agreement was obtained between predicted performance and experimental data.

  7. PREDICTION INTERVALS FOR INTEGRALS OF GAUSSIAN RANDOM FIELDS.

    PubMed

    De Oliveira, Victor; Kone, Bazoumana

    2015-03-01

    Methodology is proposed for the construction of prediction intervals for integrals of Gaussian random fields over bounded regions (called block averages in the geostatistical literature) based on observations at a finite set of sampling locations. Two bootstrap calibration algorithms are proposed, termed indirect and direct, aimed at improving upon plug-in prediction intervals in terms of coverage probability. A simulation study is carried out that illustrates the effectiveness of both procedures, and these procedures are applied to estimate block averages of chromium traces in a potentially contaminated region in Switzerland. PMID:25431507

  8. PREDICTION INTERVALS FOR INTEGRALS OF GAUSSIAN RANDOM FIELDS

    PubMed Central

    De Oliveira, Victor; Kone, Bazoumana

    2014-01-01

    Methodology is proposed for the construction of prediction intervals for integrals of Gaussian random fields over bounded regions (called block averages in the geostatistical literature) based on observations at a finite set of sampling locations. Two bootstrap calibration algorithms are proposed, termed indirect and direct, aimed at improving upon plug-in prediction intervals in terms of coverage probability. A simulation study is carried out that illustrates the effectiveness of both procedures, and these procedures are applied to estimate block averages of chromium traces in a potentially contaminated region in Switzerland. PMID:25431507

  9. Predicting the performance and innovativeness of scientists and engineers.

    PubMed

    Keller, Robert T

    2012-01-01

    A study of 644 scientists and engineers from 5 corporate research and development organizations investigated hypotheses generated from an interactionist framework of 4 individual characteristics as longitudinal predictors of performance and innovativeness. An innovative orientation predicted 1-year-later and 5-years-later supervisory job performance ratings and 5-years-later counts of patents and publications. An internal locus of control predicted 5-years-later patents and publications, and self-esteem predicted performance ratings for both times and patents. Team-level nonroutine tasks moderated the individual-level relationships between an innovative orientation and performance ratings and patents such that the relationships were stronger in a nonroutine task environment. Implications for an interactionist framework of performance and innovativeness for knowledge workers are discussed. PMID:21875172

  10. FRONTIER FIELDS: HIGH-REDSHIFT PREDICTIONS AND EARLY RESULTS

    SciTech Connect

    Coe, Dan; Bradley, Larry; Zitrin, Adi

    2015-02-20

    The Frontier Fields program is obtaining deep Hubble and Spitzer Space Telescope images of new ''blank'' fields and nearby fields gravitationally lensed by massive galaxy clusters. The Hubble images of the lensed fields are revealing nJy sources (AB mag > 31), the faintest galaxies yet observed. The full program will transform our understanding of galaxy evolution in the first 600 million years (z > 9). Previous programs have yielded a dozen or so z > 9 candidates, including perhaps fewer than expected in the Ultra Deep Field and more than expected in shallower Hubble images. In this paper, we present high-redshift (z > 6) number count predictions for the Frontier Fields and candidates in three of the first Hubble images. We show the full Frontier Fields program may yield up to ∼70 z > 9 candidates (∼6 per field). We base this estimate on an extrapolation of luminosity functions observed between 4 < z < 8 and gravitational lensing models submitted by the community. However, in the first two deep infrared Hubble images obtained to date, we find z ∼ 8 candidates but no strong candidates at z > 9. We defer quantitative analysis of the z > 9 deficit (including detection completeness estimates) to future work including additional data. At these redshifts, cosmic variance (field-to-field variation) is expected to be significant (greater than ±50%) and include clustering of early galaxies formed in overdensities. The full Frontier Fields program will significantly mitigate this uncertainty by observing six independent sightlines each with a lensing cluster and nearby blank field.

  11. Auditory performance in an open sound field

    NASA Astrophysics Data System (ADS)

    Fluitt, Kim F.; Letowski, Tomasz; Mermagen, Timothy

    2003-04-01

    Detection and recognition of acoustic sources in an open field are important elements of situational awareness on the battlefield. They are affected by many technical and environmental conditions such as type of sound, distance to a sound source, terrain configuration, meteorological conditions, hearing capabilities of the listener, level of background noise, and the listener's familiarity with the sound source. A limited body of knowledge about auditory perception of sources located over long distances makes it difficult to develop models predicting auditory behavior on the battlefield. The purpose of the present study was to determine the listener's abilities to detect, recognize, localize, and estimate distances to sound sources from 25 to 800 m from the listing position. Data were also collected for meteorological conditions (wind direction and strength, temperature, atmospheric pressure, humidity) and background noise level for each experimental trial. Forty subjects (men and women, ages 18 to 25) participated in the study. Nine types of sounds were presented from six loudspeakers in random order; each series was presented four times. Partial results indicate that both detection and recognition declined at distances greater than approximately 200 m and distance estimation was grossly underestimated by listeners. Specific results will be presented.

  12. Deciphering and prediction of plant dynamics under field conditions.

    PubMed

    Izawa, Takeshi

    2015-04-01

    Elucidation of plant dynamics under fluctuating natural environments is a challenging goal in plant physiology. Recently, using a computer statistics integrating a series of transcriptome data of field-grown rice leaves during an entire crop season and several corresponding environmental data such as solar radiation and ambient temperature, most parts of transcriptome have been modeled. This reveals the detailed contributions of developmental timing, circadian clocks and each environmental factor to transcriptome dynamics in the field and can predict transcriptome dynamics under given environments. Furthermore, some traits such as flowering time in natural environments have been shown to be predicted by mathematical models based on gene-networks parameterized with data obtained in the laboratory, and phenology models refined by knowledge of molecular genetics. New molecular physiology is beginning in plant science. PMID:25706440

  13. Prediction of Gymnastic Performance from Arousal and Anxiety Measures.

    ERIC Educational Resources Information Center

    Basler, Marilyn L.; And Others

    This study predicts gymnastic performance, arousal, and anxiety measures from past performances. Pulse rate and the Palmar Sweat Index were utilized as indicants of arousal. Anxiety was assessed by means of the State-Trait Anxiety Inventory. Eighteen members of the Ithaca College women's varsity gymnastic team were tested throughout the 1973-74…

  14. Evaluation of abutment scour prediction equations with field data

    USGS Publications Warehouse

    Benedict, S.T.; Deshpande, N.; Aziz, N.M.

    2007-01-01

    The U.S. Geological Survey, in cooperation with FHWA, compared predicted abutment scour depths, computed with selected predictive equations, with field observations collected at 144 bridges in South Carolina and at eight bridges from the National Bridge Scour Database. Predictive equations published in the 4th edition of Evaluating Scour at Bridges (Hydraulic Engineering Circular 18) were used in this comparison, including the original Froehlich, the modified Froehlich, the Sturm, the Maryland, and the HIRE equations. The comparisons showed that most equations tended to provide conservative estimates of scour that at times were excessive (as large as 158 ft). Equations also produced underpredictions of scour, but with less frequency. Although the equations provide an important resource for evaluating abutment scour at bridges, the results of this investigation show the importance of using engineering judgment in conjunction with these equations.

  15. Predicting Course Performance in Freshman and Sophomore Physics Courses: Women Are More Predictable than Men.

    ERIC Educational Resources Information Center

    McCammon, Susan; And Others

    1988-01-01

    Investigates the extent to which thinking skills and mathematical competency would predict the course performance of freshman and sophomore science majors enrolled in physics courses. Finds that algebra ability and critical thinking skills were the best predictors. (Author/YP)

  16. Prediction of Muscle Performance During Dynamic Repetitive Exercise

    NASA Technical Reports Server (NTRS)

    Byerly, D. L.; Byerly, K. A.; Sognier, M. A.; Squires, W. G.

    2002-01-01

    A method for predicting human muscle performance was developed. Eight test subjects performed a repetitive dynamic exercise to failure using a Lordex spinal machine. Electromyography (EMG) data was collected from the erector spinae. Evaluation of the EMG data using a 5th order Autoregressive (AR) model and statistical regression analysis revealed that an AR parameter, the mean average magnitude of AR poles, can predict performance to failure as early as the second repetition of the exercise. Potential applications to the space program include evaluating on-orbit countermeasure effectiveness, maximizing post-flight recovery, and future real-time monitoring capability during Extravehicular Activity.

  17. Reading performance is predicted by more than phonological processing

    PubMed Central

    Kibby, Michelle Y.; Lee, Sylvia E.; Dyer, Sarah M.

    2014-01-01

    We compared three phonological processing components (phonological awareness, rapid automatized naming and phonological memory), verbal working memory, and attention control in terms of how well they predict the various aspects of reading: word recognition, pseudoword decoding, fluency and comprehension, in a mixed sample of 182 children ages 8–12 years. Participants displayed a wide range of reading ability and attention control. Multiple regression was used to determine how well the phonological processing components, verbal working memory, and attention control predict reading performance. All equations were highly significant. Phonological memory predicted word identification and decoding. In addition, phonological awareness and rapid automatized naming predicted every aspect of reading assessed, supporting the notion that phonological processing is a core contributor to reading ability. Nonetheless, phonological processing was not the only predictor of reading performance. Verbal working memory predicted fluency, decoding and comprehension, and attention control predicted fluency. Based upon our results, when using Baddeley’s model of working memory it appears that the phonological loop contributes to basic reading ability, whereas the central executive contributes to fluency and comprehension, along with decoding. Attention control was of interest as some children with ADHD have poor reading ability even if it is not sufficiently impaired to warrant diagnosis. Our finding that attention control predicts reading fluency is consistent with prior research which showed sustained attention plays a role in fluency. Taken together, our results suggest that reading is a highly complex skill that entails more than phonological processing to perform well. PMID:25285081

  18. Product component genealogy modeling and field-failure prediction

    DOE PAGESBeta

    King, Caleb; Hong, Yili; Meeker, William Q.

    2016-04-13

    Many industrial products consist of multiple components that are necessary for system operation. There is an abundance of literature on modeling the lifetime of such components through competing risks models. During the life-cycle of a product, it is common for there to be incremental design changes to improve reliability, to reduce costs, or due to changes in availability of certain part numbers. These changes can affect product reliability but are often ignored in system lifetime modeling. By incorporating this information about changes in part numbers over time (information that is readily available in most production databases), better accuracy can bemore » achieved in predicting time to failure, thus yielding more accurate field-failure predictions. This paper presents methods for estimating parameters and predictions for this generational model and a comparison with existing methods through the use of simulation. Our results indicate that the generational model has important practical advantages and outperforms the existing methods in predicting field failures.« less

  19. Protein Secondary Structure Prediction Using Deep Convolutional Neural Fields.

    PubMed

    Wang, Sheng; Peng, Jian; Ma, Jianzhu; Xu, Jinbo

    2016-01-01

    Protein secondary structure (SS) prediction is important for studying protein structure and function. When only the sequence (profile) information is used as input feature, currently the best predictors can obtain ~80% Q3 accuracy, which has not been improved in the past decade. Here we present DeepCNF (Deep Convolutional Neural Fields) for protein SS prediction. DeepCNF is a Deep Learning extension of Conditional Neural Fields (CNF), which is an integration of Conditional Random Fields (CRF) and shallow neural networks. DeepCNF can model not only complex sequence-structure relationship by a deep hierarchical architecture, but also interdependency between adjacent SS labels, so it is much more powerful than CNF. Experimental results show that DeepCNF can obtain ~84% Q3 accuracy, ~85% SOV score, and ~72% Q8 accuracy, respectively, on the CASP and CAMEO test proteins, greatly outperforming currently popular predictors. As a general framework, DeepCNF can be used to predict other protein structure properties such as contact number, disorder regions, and solvent accessibility. PMID:26752681

  20. Predictive value of ventilatory inflection points determined under field conditions.

    PubMed

    Heyde, Christian; Mahler, Hubert; Roecker, Kai; Gollhofer, Albert

    2016-05-01

    The aim of this study was to evaluate the predictive potential provided by two ventilatory inflection points (VIP1 and VIP2) examined in field without using gas analysis systems and uncomfortable facemasks. A calibrated respiratory inductance plethysmograph (RIP) and a computerised routine were utilised, respectively, to derive ventilation and to detect VIP1 and VIP2 during a standardised field ramp test on a 400 m running track on 81 participants. In addition, average running speed of a competitive 1000 m run (S1k) was observed as criterion. The predictive value of running speed at VIP1 (SVIP1) and the speed range between VIP1 and VIP2 in relation to VIP2 (VIPSPAN) was analysed via regression analysis. VIPSPAN rather than running speed at VIP2 (SVIP2) was operationalised as a predictor to consider the covariance between SVIP1 and SVIP2. SVIP1 and VIPSPAN, respectively, provided 58.9% and 22.9% of explained variance in regard to S1k. Considering covariance, the timing of two ventilatory inflection points provides predictive value in regard to a competitive 1000 m run. This is the first study to apply computerised detection of ventilatory inflection points in a field setting independent on measurements of the respiratory gas exchange and without using any facemasks. PMID:26190229

  1. Protein Secondary Structure Prediction Using Deep Convolutional Neural Fields

    PubMed Central

    Wang, Sheng; Peng, Jian; Ma, Jianzhu; Xu, Jinbo

    2016-01-01

    Protein secondary structure (SS) prediction is important for studying protein structure and function. When only the sequence (profile) information is used as input feature, currently the best predictors can obtain ~80% Q3 accuracy, which has not been improved in the past decade. Here we present DeepCNF (Deep Convolutional Neural Fields) for protein SS prediction. DeepCNF is a Deep Learning extension of Conditional Neural Fields (CNF), which is an integration of Conditional Random Fields (CRF) and shallow neural networks. DeepCNF can model not only complex sequence-structure relationship by a deep hierarchical architecture, but also interdependency between adjacent SS labels, so it is much more powerful than CNF. Experimental results show that DeepCNF can obtain ~84% Q3 accuracy, ~85% SOV score, and ~72% Q8 accuracy, respectively, on the CASP and CAMEO test proteins, greatly outperforming currently popular predictors. As a general framework, DeepCNF can be used to predict other protein structure properties such as contact number, disorder regions, and solvent accessibility. PMID:26752681

  2. Protein Secondary Structure Prediction Using Deep Convolutional Neural Fields

    NASA Astrophysics Data System (ADS)

    Wang, Sheng; Peng, Jian; Ma, Jianzhu; Xu, Jinbo

    2016-01-01

    Protein secondary structure (SS) prediction is important for studying protein structure and function. When only the sequence (profile) information is used as input feature, currently the best predictors can obtain ~80% Q3 accuracy, which has not been improved in the past decade. Here we present DeepCNF (Deep Convolutional Neural Fields) for protein SS prediction. DeepCNF is a Deep Learning extension of Conditional Neural Fields (CNF), which is an integration of Conditional Random Fields (CRF) and shallow neural networks. DeepCNF can model not only complex sequence-structure relationship by a deep hierarchical architecture, but also interdependency between adjacent SS labels, so it is much more powerful than CNF. Experimental results show that DeepCNF can obtain ~84% Q3 accuracy, ~85% SOV score, and ~72% Q8 accuracy, respectively, on the CASP and CAMEO test proteins, greatly outperforming currently popular predictors. As a general framework, DeepCNF can be used to predict other protein structure properties such as contact number, disorder regions, and solvent accessibility.

  3. Field performance of a premium heating oil

    SciTech Connect

    Santa, T.; Jetter, S.M.

    1996-07-01

    As part of our ongoing research to provide quality improvements to heating oil, Mobil Oil together with Santa Fuel, Inc., conducted a field trial to investigate the performance of a new premium heating oil. This premium heating oil contains an additive system designed to minimize sludge related problems in the fuel delivery system of residential home heating systems. The additive used was similar to others reported at this and earlier BNL conferences, but was further developed to enhance its performance in oil heat systems. The premium heating oil was bulk additized and delivered to a subset of the customer base. Fuel related, unscheduled service calls were monitored in this test area, as well as in a similar baseline area that did not receive the premium heating oil. Overall, the premium fuel provided a 45% reduction in the occurrence of fuel related, unscheduled service calls as compared to the baseline area. Within this population, there was a reduction of 38% in systems with 275 gallon tanks, and 55% in systems that had >275 gallon tanks showing that the additive is effective in the various configurations of residential oil heat systems. In addition, photographic documentation collected at two accounts supported this improvement by clearly showing that the equipment remained cleaner with the premium heating oil than with regular heating oil. Based on these results, a full marketing trial of this new product has been initiated by Mobil and Santa Fuel, Inc., during the 1995-1996 heating season.

  4. Recent progress towards predicting aircraft ground handling performance

    NASA Technical Reports Server (NTRS)

    Yager, T. J.; White, E. J.

    1981-01-01

    Capability implemented in simulating aircraft ground handling performance is reviewed and areas for further expansion and improvement are identified. Problems associated with providing necessary simulator input data for adequate modeling of aircraft tire/runway friction behavior are discussed and efforts to improve tire/runway friction definition, and simulator fidelity are described. Aircraft braking performance data obtained on several wet runway surfaces are compared to ground vehicle friction measurements. Research to improve methods of predicting tire friction performance are discussed.

  5. Predicting Performance in Higher Education Using Proximal Predictors

    PubMed Central

    Niessen, A. Susan M.; Meijer, Rob R.; Tendeiro, Jorge N.

    2016-01-01

    We studied the validity of two methods for predicting academic performance and student-program fit that were proximal to important study criteria. Applicants to an undergraduate psychology program participated in a selection procedure containing a trial-studying test based on a work sample approach, and specific skills tests in English and math. Test scores were used to predict academic achievement and progress after the first year, achievement in specific course types, enrollment, and dropout after the first year. All tests showed positive significant correlations with the criteria. The trial-studying test was consistently the best predictor in the admission procedure. We found no significant differences between the predictive validity of the trial-studying test and prior educational performance, and substantial shared explained variance between the two predictors. Only applicants with lower trial-studying scores were significantly less likely to enroll in the program. In conclusion, the trial-studying test yielded predictive validities similar to that of prior educational performance and possibly enabled self-selection. In admissions aimed at student-program fit, or in admissions in which past educational performance is difficult to use, a trial-studying test is a good instrument to predict academic performance. PMID:27073859

  6. On the predictiveness of single-field inflationary models

    NASA Astrophysics Data System (ADS)

    Burgess, C. P.; Patil, Subodh P.; Trott, Michael

    2014-06-01

    We re-examine the predictiveness of single-field inflationary models and discuss how an unknown UV completion can complicate determining inflationary model parameters from observations, even from precision measurements. Besides the usual naturalness issues associated with having a shallow inflationary potential, we describe another issue for inflation, namely, unknown UV physics modifies the running of Standard Model (SM) parameters and thereby introduces uncertainty into the potential inflationary predictions. We illustrate this point using the minimal Higgs Inflationary scenario, which is arguably the most predictive single-field model on the market, because its predictions for A S , r and n s are made using only one new free parameter beyond those measured in particle physics experiments, and run up to the inflationary regime. We find that this issue can already have observable effects. At the same time, this UV-parameter dependence in the Renormalization Group allows Higgs Inflation to occur (in principle) for a slightly larger range of Higgs masses. We comment on the origin of the various UV scales that arise at large field values for the SM Higgs, clarifying cut off scale arguments by further developing the formalism of a non-linear realization of SU L (2) × U(1) in curved space. We discuss the interesting fact that, outside of Higgs Inflation, the effect of a non-minimal coupling to gravity, even in the SM, results in a non-linear EFT for the Higgs sector. Finally, we briefly comment on post BICEP2 attempts to modify the Higgs Inflation scenario.

  7. Tailor-made force fields for crystal-structure prediction.

    PubMed

    Neumann, Marcus A

    2008-08-14

    A general procedure is presented to derive a complete set of force-field parameters for flexible molecules in the crystalline state on a case-by-case basis. The force-field parameters are fitted to the electrostatic potential as well as to accurate energies and forces generated by means of a hybrid method that combines solid-state density functional theory (DFT) calculations with an empirical van der Waals correction. All DFT calculations are carried out with the VASP program. The mathematical structure of the force field, the generation of reference data, the choice of the figure of merit, the optimization algorithm, and the parameter-refinement strategy are discussed in detail. The approach is applied to cyclohexane-1,4-dione, a small flexible ring. The tailor-made force field obtained for cyclohexane-1,4-dione is used to search for low-energy crystal packings in all 230 space groups with one molecule per asymmetric unit, and the most stable crystal structures are reoptimized in a second step with the hybrid method. The experimental crystal structure is found as the most stable predicted crystal structure both with the tailor-made force field and the hybrid method. The same methodology has also been applied successfully to the four compounds of the fourth CCDC blind test on crystal-structure prediction. For the five aforementioned compounds, the root-mean-square deviations between lattice energies calculated with the tailor-made force fields and the hybrid method range from 0.024 to 0.053 kcal/mol per atom around an average value of 0.034 kcal/mol per atom. PMID:18642947

  8. Proactive Supply Chain Performance Management with Predictive Analytics

    PubMed Central

    Stefanovic, Nenad

    2014-01-01

    Today's business climate requires supply chains to be proactive rather than reactive, which demands a new approach that incorporates data mining predictive analytics. This paper introduces a predictive supply chain performance management model which combines process modelling, performance measurement, data mining models, and web portal technologies into a unique model. It presents the supply chain modelling approach based on the specialized metamodel which allows modelling of any supply chain configuration and at different level of details. The paper also presents the supply chain semantic business intelligence (BI) model which encapsulates data sources and business rules and includes the data warehouse model with specific supply chain dimensions, measures, and KPIs (key performance indicators). Next, the paper describes two generic approaches for designing the KPI predictive data mining models based on the BI semantic model. KPI predictive models were trained and tested with a real-world data set. Finally, a specialized analytical web portal which offers collaborative performance monitoring and decision making is presented. The results show that these models give very accurate KPI projections and provide valuable insights into newly emerging trends, opportunities, and problems. This should lead to more intelligent, predictive, and responsive supply chains capable of adapting to future business environment. PMID:25386605

  9. Proactive supply chain performance management with predictive analytics.

    PubMed

    Stefanovic, Nenad

    2014-01-01

    Today's business climate requires supply chains to be proactive rather than reactive, which demands a new approach that incorporates data mining predictive analytics. This paper introduces a predictive supply chain performance management model which combines process modelling, performance measurement, data mining models, and web portal technologies into a unique model. It presents the supply chain modelling approach based on the specialized metamodel which allows modelling of any supply chain configuration and at different level of details. The paper also presents the supply chain semantic business intelligence (BI) model which encapsulates data sources and business rules and includes the data warehouse model with specific supply chain dimensions, measures, and KPIs (key performance indicators). Next, the paper describes two generic approaches for designing the KPI predictive data mining models based on the BI semantic model. KPI predictive models were trained and tested with a real-world data set. Finally, a specialized analytical web portal which offers collaborative performance monitoring and decision making is presented. The results show that these models give very accurate KPI projections and provide valuable insights into newly emerging trends, opportunities, and problems. This should lead to more intelligent, predictive, and responsive supply chains capable of adapting to future business environment. PMID:25386605

  10. TAS: A Transonic Aircraft/Store flow field prediction code

    NASA Technical Reports Server (NTRS)

    Thompson, D. S.

    1983-01-01

    A numerical procedure has been developed that has the capability to predict the transonic flow field around an aircraft with an arbitrarily located, separated store. The TAS code, the product of a joint General Dynamics/NASA ARC/AFWAL research and development program, will serve as the basis for a comprehensive predictive method for aircraft with arbitrary store loadings. This report described the numerical procedures employed to simulate the flow field around a configuration of this type. The validity of TAS code predictions is established by comparison with existing experimental data. In addition, future areas of development of the code are outlined. A brief description of code utilization is also given in the Appendix. The aircraft/store configuration is simulated using a mesh embedding approach. The computational domain is discretized by three meshes: (1) a planform-oriented wing/body fine mesh, (2) a cylindrical store mesh, and (3) a global Cartesian crude mesh. This embedded mesh scheme enables simulation of stores with fins of arbitrary angular orientation.

  11. Field theory and diffusion creep predictions in polycrystalline aggregates

    NASA Astrophysics Data System (ADS)

    Villani, A.; Busso, E. P.; Forest, S.

    2015-07-01

    In polycrystals, stress-driven vacancy diffusion at high homologous temperatures leads to inelastic deformation. In this work, a novel continuum mechanics framework is proposed to describe the strain fields resulting from such a diffusion-driven process in a polycrystalline aggregate where grains and grain boundaries are explicitly considered. The choice of an anisotropic eigenstrain in the grain boundary region provides the driving force for the diffusive creep processes. The corresponding inelastic strain rate is shown to be related to the gradient of the vacancy flux. Dislocation driven deformation is then introduced as an additional mechanism, through standard crystal plasticity constitutive equations. The fully coupled diffusion-mechanical model is implemented into the finite element method and then used to describe the biaxial creep behaviour of FCC polycrystalline aggregates. The corresponding results revealed for the first time that such a coupled diffusion-stress approach, involving the gradient of the vacancy flux, can accurately predict the well-known macroscopic strain rate dependency on stress and grain size in the diffusion creep regime. They also predict strongly heterogeneous viscoplastic strain fields, especially close to grain boundaries triple junctions. Finally, a smooth transition from Herring and Coble to dislocation creep behaviour is predicted and compared to experimental results for copper.

  12. A free wake method for performance prediction of VAWT

    NASA Astrophysics Data System (ADS)

    Ilin, S.; Dumitrescu, H.; Cardos, V.; Dumitrache, A.

    2012-09-01

    Based on the lifting line theory and a free vortex wake model, a method including dynamic stall effects is presented for predicting the performance of a three-dimensional vertical-axis wind turbine (VAWT). A vortex model is used in which the wake is composed of trailing streamwise and shedding spanwise vortices, whose strengths are equal to the change in the bound vortex strength as dictated by Helmholtz and Kelvin's theorems. Performance parameters are calculated by application of the Biot-Savart law along with the Kutta-Joukowski theorem and a semi-empirical dynamic stall model. Predictions are shown to compare favorably with existing experimental data.

  13. Prediction of muscle performance during dynamic repetitive movement

    NASA Technical Reports Server (NTRS)

    Byerly, D. L.; Byerly, K. A.; Sognier, M. A.; Squires, W. G.

    2003-01-01

    BACKGROUND: During long-duration spaceflight, astronauts experience progressive muscle atrophy and often perform strenuous extravehicular activities. Post-flight, there is a lengthy recovery period with an increased risk for injury. Currently, there is a critical need for an enabling tool to optimize muscle performance and to minimize the risk of injury to astronauts while on-orbit and during post-flight recovery. Consequently, these studies were performed to develop a method to address this need. METHODS: Eight test subjects performed a repetitive dynamic exercise to failure at 65% of their upper torso weight using a Lordex spinal machine. Surface electromyography (SEMG) data was collected from the erector spinae back muscle. The SEMG data was evaluated using a 5th order autoregressive (AR) model and linear regression analysis. RESULTS: The best predictor found was an AR parameter, the mean average magnitude of AR poles, with r = 0.75 and p = 0.03. This parameter can predict performance to failure as early as the second repetition of the exercise. CONCLUSION: A method for predicting human muscle performance early during dynamic repetitive exercise was developed. The capability to predict performance to failure has many potential applications to the space program including evaluating countermeasure effectiveness on-orbit, optimizing post-flight recovery, and potential future real-time monitoring capability during extravehicular activity.

  14. Predicting Poor Physical Performance after Total Knee Arthroplasty

    PubMed Central

    Bade, Michael J; Wolfe, Pamela; Zeni, Joseph A; Stevens-Lapsley, Jennifer E.; Snyder-Mackler, Lynn

    2012-01-01

    The purpose of this study was to develop a preliminary decision algorithm predicting functional performance outcomes to aid in the decision of when to undergo total knee arthroplasty (TKA). One hundred nineteen patients undergoing primary unilateral TKA were evaluated before and 6 months after TKA. A regression tree analysis using a recursive partitioning function was performed with the Timed Up and Go (TUG) time, Six-Minute Walk (6MW) distance, and Stair Climbing Test (SCT) time as measured 6 months after TKA as the primary outcomes. Preoperative measures of functional performance, joint performance, anthropometrics, demographics, and self reported status were evaluated as predictors of the primary outcomes 6 months after surgery. Individuals taking ≥ 10.1 seconds on the TUG and aged 72 years or older before surgery had the poorest performance on the TUG 6 months after surgery. Individuals walking < 314 meters on the 6MW before surgery had the poorest performance on the 6MW test 6 months after surgery. Individuals taking ≥ 17 seconds to complete the SCT and scoring < 40 on the SF-36 mental component score before surgery had the poorest performance on the SCT 6 months after surgery. Poorer performance preoperatively on the 6MW, SCT, and TUG, was related to poorer performance in the same measure after TKA. Age and decreased mental health were secondary predictors of poorer performance at 6 months on the TUG and SCT, respectively. These measures may help further develop models predicting thresholds for poor outcomes after TKA. PMID:22539338

  15. The Predictive Performance and Stability of Six Species Distribution Models

    PubMed Central

    Huang, Min-Yi; Fan, Wei-Yi; Wang, Zhi-Gao

    2014-01-01

    Background Predicting species’ potential geographical range by species distribution models (SDMs) is central to understand their ecological requirements. However, the effects of using different modeling techniques need further investigation. In order to improve the prediction effect, we need to assess the predictive performance and stability of different SDMs. Methodology We collected the distribution data of five common tree species (Pinus massoniana, Betula platyphylla, Quercus wutaishanica, Quercus mongolica and Quercus variabilis) and simulated their potential distribution area using 13 environmental variables and six widely used SDMs: BIOCLIM, DOMAIN, MAHAL, RF, MAXENT, and SVM. Each model run was repeated 100 times (trials). We compared the predictive performance by testing the consistency between observations and simulated distributions and assessed the stability by the standard deviation, coefficient of variation, and the 99% confidence interval of Kappa and AUC values. Results The mean values of AUC and Kappa from MAHAL, RF, MAXENT, and SVM trials were similar and significantly higher than those from BIOCLIM and DOMAIN trials (p<0.05), while the associated standard deviations and coefficients of variation were larger for BIOCLIM and DOMAIN trials (p<0.05), and the 99% confidence intervals for AUC and Kappa values were narrower for MAHAL, RF, MAXENT, and SVM. Compared to BIOCLIM and DOMAIN, other SDMs (MAHAL, RF, MAXENT, and SVM) had higher prediction accuracy, smaller confidence intervals, and were more stable and less affected by the random variable (randomly selected pseudo-absence points). Conclusions According to the prediction performance and stability of SDMs, we can divide these six SDMs into two categories: a high performance and stability group including MAHAL, RF, MAXENT, and SVM, and a low performance and stability group consisting of BIOCLIM, and DOMAIN. We highlight that choosing appropriate SDMs to address a specific problem is an important

  16. Predictive performance of a model of anaesthetic uptake with desflurane.

    PubMed

    Kennedy, R

    2006-04-01

    We have previously shown that a model of anaesthetic uptake and distribution, developed for use as a teaching tool, is able to predict end-tidal isoflurane and sevoflurane concentrations at least as well as commonly used propofol models predict blood levels of propofol. Models with good predictive performance may be useful as part of real-time prediction systems. The aim of this study was to assess the performance of this model with desflurane. Twenty adult patients undergoing routine anaesthesia were studied. The total fresh gas flow and vaporizor settings were collected at 10-second intervals from the anaesthetic machine. These data were used as inputs to the model, which had been initialized for patient weight and desflurane. Output of the model is a predicted end-tidal value at each point in time. These values were compared with measured end-tidal desflurane using a standard statistical technique of Varvel and colleagues. Data was analysed from 19 patients. Median performance error was 78% (95% CI 8-147), median absolute performance error 77% (6-149), divergence 10.6%/h (-80-101) and wobble 8.9% (-6-24). The predictive performance of this model with desflurane was poor, with considerable variability between patients. The reasons for the difference between desflurane and our previous results with isoflurane and sevoflurane are not obvious, but may provide important clues to the necessary components for such models. The data collected in this study may assist in the development and evaluation of improved models. PMID:16617640

  17. [The quality control based on the predictable performance].

    PubMed

    Zheng, D X

    2016-09-01

    The clinical performance can only be evaluated when it comes to the last step in the conventional way of prosthesis. However, it often causes the failure because of the unconformity between the expectation and final performance. Resulting from this kind of situation, quality control based on the predictable results has been suggested. It is a new idea based on the way of reverse thinking, and focuses on the need of patient and puts the final performance of the prosthesis to the first place. With the prosthodontically driven prodedure, dentists can complete the unification with the expectation and the final performance. PMID:27596338

  18. Key issues influencing the performance of near-field barriers

    SciTech Connect

    Tasker, P.W.; Wisbey, S.J.; Boyle, C.B.

    1993-12-31

    In developing a national strategy for the disposal of radioactive wastes, each country will consider isolation options that are appropriate to the types of waste that are produced. The options are developed in response to specific national regulatory requirements, and thus will focus on different aspects of performance. However, there are a number of technical concerns that are common to all programmes. The major issues concerning the behavior of the chemical and physical barriers in the near field of a radioactive waste repository are discussed in this paper. The description of key issue has been divided into the following categories: barrier design, barrier evolution, scientific understanding through modelling, and validation of performance. The near-field barriers are selected and designed to provide appropriate radionuclide containment and control. Factors affecting the evolution of these barriers, such as container degradation and gas generation, determine the subsequent release of radionuclides to the human environment. Modelling repository evolution is therefore an integral feature of performance assessments, and issues such as the treatment of inhomogeneities and non-equilibrium chemistry may need to be addressed. However, the use of mathematical and computer models implies a requirement for validation. The use of demonstration experiments and natural analogues builds confidence in the predictions of repository performance models, and provides a degree of validation for otherwise inaccessible timescales.

  19. Near-field noise predictions of an aircraft in cruise

    NASA Technical Reports Server (NTRS)

    Rawls, John W., Jr.

    1987-01-01

    The physics of the coupling of sound waves with the boundary layer is not yet well understood. It is believed, however, that for effective coupling of the sound waves and instability waves in the boundary layer, a matching of both frequency and wave number must occur. This requires that the sound field be accurately defined in both space and time. Currently analytical prediction methods lack sufficient accuracy to predict the noise levels from components of a turbofan engine. Although empirical methods do not yield the detail required for an analysis of the receptivity of sound by a boundary layer, valuable insight can be gained as to the changes in noise levels that might be expected under various operating conditions and aircraft configurations.

  20. Predictive Potential Field-Based Collision Avoidance for Multicopters

    NASA Astrophysics Data System (ADS)

    Nieuwenhuisen, M.; Schadler, M.; Behnke, S.

    2013-08-01

    Reliable obstacle avoidance is a key to navigating with UAVs in the close vicinity of static and dynamic obstacles. Wheel-based mobile robots are often equipped with 2D or 3D laser range finders that cover the 2D workspace sufficiently accurate and at a high rate. Micro UAV platforms operate in a 3D environment, but the restricted payload prohibits the use of fast state-of-the-art 3D sensors. Thus, perception of small obstacles is often only possible in the vicinity of the UAV and a fast collision avoidance system is necessary. We propose a reactive collision avoidance system based on artificial potential fields, that takes the special dynamics of UAVs into account by predicting the influence of obstacles on the estimated trajectory in the near future using a learned motion model. Experimental evaluation shows that the prediction leads to smoother trajectories and allows to navigate collision-free through passageways.

  1. Zonal procedure for predicting the hover performance of a helicopter rotor

    NASA Astrophysics Data System (ADS)

    Moulton, Marvin Allyn

    The prediction of the performance of rotorcraft is complicated by the need to simultaneously account for many disparate elements in a single problem. To date, most CFD (Computational Fluid Dynamics) analyses of rotorcraft have been concerned with the computation of the flow on isolated elements-such as the flow on the blade surface. The treatment of realistic configurations requires the development of a methodology which can include a wide range of flow elements-especially, the main rotor and its wake system. This dissertation concerns the development of a new scheme for computing the flow of a complete rotor/wake system and applying this to predict the hover performance of a helicopter rotor. Navier-Stokes solvers are needed for predicting viscous effects, but do not have the ability to compute extensive wake regions without numerical dissipation. On the other hand, a vorticity embedded code can easily handle the wake but cannot predict the surface viscous flow. Therefore, this problem requires a zonal approach. To predict the profile power, a Navier-Stokes analysis is used near the blade surface. To avoid dissipation of the wake, the far field convection scheme is based on a full- potential solver equipped with vorticity embedding. Application of the zonal procedure to predict the hover performance of the Sikorsky UH-60A rotor provides the first evaluation of this method. Performance predictions of the Army AH-64A rotor demonstrate a new ability to predict hovering flows into the stall regime.

  2. Predictive Bias and Sensitivity in NRC Fuel Performance Codes

    SciTech Connect

    Geelhood, Kenneth J.; Luscher, Walter G.; Senor, David J.; Cunningham, Mitchel E.; Lanning, Donald D.; Adkins, Harold E.

    2009-10-01

    The latest versions of the fuel performance codes, FRAPCON-3 and FRAPTRAN were examined to determine if the codes are intrinsically conservative. Each individual model and type of code prediction was examined and compared to the data that was used to develop the model. In addition, a brief literature search was performed to determine if more recent data have become available since the original model development for model comparison.

  3. Prediction of Airplane Sonic-Boom Pressure Fields

    NASA Technical Reports Server (NTRS)

    Carlson, Harry W.; McLean, F. Edward; Middleton, Wilbur D.

    1965-01-01

    This paper presents a discussion of the sensitivity of supersonic-transport design and operation to sonic-boom considerations and shows the necessity for a study of these problems early in the development program. Methods of predicting pressure signatures are outlined and examples of the correlation of these estimates with wind-tunnel and flight measurements are shown. Estimates of sonic-boom characteristics for a representative supersonic transport show that in the critical transonic acceleration portion of the flight, overpressures somewhat lower than estimated by the use of far-field assumptions may be expected. Promising design possibilities for the achievement of further overpressure reductions are explored.

  4. Predicting waste stabilization pond performance using an ecological simulation model

    SciTech Connect

    New, G.R.

    1987-01-01

    Waste stabilization ponds (lagoons) are often favored in small communities because of their low cost and ease of operation. Most models currently used to predict performance are empirical or fail to address the primary lagoon cell. Empirical methods for predicting lagoon performance have been found to be off as much as 248 percent when used on a system other than the one they were developed for. Also, the present models developed for the primary cell lack the ability to predict parameters other than biochemical oxygen demand (BOD) and nitrogen. Oxygen consumption is usually estimated from BOD utilization. LAGOON is a fortran program which models the biogeochemical processes characteristic of the primary cell of facultative lagoons. Model parameters can be measured from lagoons in the vicinity of a proposed lagoon or estimated from laboratory studies. The model was calibrated utilizing a subset of the Corinne Utah lagoon data then validated utilizing a subset of the Corinne Utah data.

  5. Internal performance predictions for Langley scramjet engine module

    NASA Technical Reports Server (NTRS)

    Pinckney, S. Z.

    1978-01-01

    A one dimensional theoretical method for the prediction of the internal performance of a scramjet engine is presented. The effects of changes in vehicle forebody flow parameters and characteristics on predicted thrust for the scramjet engine were evaluated using this method, and results are presented. A theoretical evaluation of the effects of changes in the scramjet engine's internal parameters is also presented. Theoretical internal performance predictions, in terms thrust coefficient and specific impulse, are provided for the scramjet engine for free stream Mach numbers of 5, 6, and 7 free stream dynamic pressure of 23,940 N/sq m forebody surface angles of 4.6 deg to 14.6 deg, and fuel equivalence ratio of 1.0.

  6. Performance prediction for 3D filtering of multichannel images

    NASA Astrophysics Data System (ADS)

    Rubel, Oleksii; Kozhemiakin, Ruslan A.; Abramov, Sergey K.; Lukin, Vladimir V.; Vozel, Benoit; Chehdi, Kacem

    2015-10-01

    Performance of denoising based on discrete cosine transform applied to multichannel remote sensing images corrupted by additive white Gaussian noise is analyzed. Images obtained by satellite Earth Observing-1 (EO-1) mission using hyperspectral imager instrument (Hyperion) that have high input SNR are taken as test images. Denoising performance is characterized by improvement of PSNR. For hard-thresholding 3D DCT-based denoising, simple statistics (probabilities to be less than a certain threshold) are used to predict denoising efficiency using curves fitted into scatterplots. It is shown that the obtained curves (approximations) provide prediction of denoising efficiency with high accuracy. Analysis is carried out for different numbers of channels processed jointly. Universality of prediction for different number of channels is proven.

  7. Classification performance prediction using parametric scattering feature models

    NASA Astrophysics Data System (ADS)

    Chiang, Hung-Chih; Moses, Randolph L.; Potter, Lee C.

    2000-08-01

    We consider a method for estimating classification performance of a model-based synthetic aperture radar (SAR) automatic target recognition system. Target classification is performed by comparing an unordered feature set extracted from a measured SAR image chip with an unordered feature set predicted from a hypothesized target class and pose. A Bayes likelihood metric that incorporates uncertainty in both the predicted and extracted feature vectors is used to compute the match score. Evaluation of the match likelihoods requires a correspondence between the unordered predicted and extracted feature sets. This is a bipartite graph matching problem with insertions and deletions; we show that the optimal match can be found in polynomial time. We extend the results in 1 to estimate classification performance for a ten-class SAR ATR problem. We consider a synthetic classification problem to validate the classifier and to address resolution and robustness questions in the likelihood scoring method. Specifically, we consider performance versus SAR resolution, performance degradation due to mismatch between the assumed and actual feature statistics, and performance impact of correlated feature attributes.

  8. Prediction of Nine Month Performance from Neonatal and Developmental Criteria.

    ERIC Educational Resources Information Center

    Sweet, John F., Jr.; And Others

    This study investigated the ability of the Neonatal Behavioral Assessment Scale (NBAS), in combination with neonatal histories and developmental assessments, to predict mental and motor performance of 9-month-old infants on the Bayley Scales of Infant Development (BSID). Fourteen normal, full-term infants and 10 average-for-gestational-age,…

  9. A model for analytical performance prediction of hypervapotron

    SciTech Connect

    Baxi, C.B.; Falter, H.

    1992-07-01

    A hypervapotron is a water-cooled device which combines the advantages of finned surfaces with the large heat transfer rates possible during boiling heat transfer. Hypervapotrons have been used as beam dumps in the past and plans are under way to use them for divertor cooling in the Joint European Torus (JET). Experiments at JET have shows that a surface heat flux of 25 MW/m{sup 2} can be achieved in hypervapotrons. This performance makes such a device very attractive for cooling of divertor of the International Thermonuclear Experimental Reactor (ITER). This paper presents an analytical method to predict the thermal performance of the hypervapotrons. Preliminary results show an excellent agreement between experimental results and analytical prediction over a wide range of flow velocities, pressures, subcooling temperatures and heat fluxes. This paper also presents the predicted performance of hypervapotron made of materials other than copper. After further development and verification, the analytical method could be used for optimizing designs and performance prediction.

  10. The Role of Means Efficacy When Predicting Creative Performance

    ERIC Educational Resources Information Center

    Simmons, Aneika L.; Payne, Stephanie C.; Pariyothorn, Matthew M.

    2014-01-01

    According to the "Internal-External Efficacy model", self-efficacy is an insufficient explanation for self-regulated behavior because it ignores the influence of external resources. Applying this theory of motivation to the prediction of creative performance, the extent to which means efficacy or the belief in the utility of external…

  11. Image processing system performance prediction and product quality evaluation

    NASA Technical Reports Server (NTRS)

    Stein, E. K.; Hammill, H. B. (Principal Investigator)

    1976-01-01

    The author has identified the following significant results. A new technique for image processing system performance prediction and product quality evaluation was developed. It was entirely objective, quantitative, and general, and should prove useful in system design and quality control. The technique and its application to determination of quality control procedures for the Earth Resources Technology Satellite NASA Data Processing Facility are described.

  12. Prediction of Military Turnover Using Intentions, Satisfaction, and Performance.

    ERIC Educational Resources Information Center

    Knapp, Deirdre J.; And Others

    Although researchers have examined the link between job attitudes and turnover, some studies claim that civilian samples may not be generalizable to military personnel. This paper addresses two central questions: (1) To what extent does job satisfaction, job performance, and reenlistment intentions predict reenlistment behavior?; (2) To what…

  13. Analysis of Factors that Predict Clinical Performance in Medical School

    ERIC Educational Resources Information Center

    White, Casey B.; Dey, Eric L.; Fantone, Joseph C.

    2009-01-01

    Academic achievement indices including GPAs and MCAT scores are used to predict the spectrum of medical student academic performance types. However, use of these measures ignores two changes influencing medical school admissions: student diversity and affirmative action, and an increased focus on communication skills. To determine if GPA and MCAT…

  14. Process for predicting structural performance of mechanical systems

    DOEpatents

    Gardner, David R.; Hendrickson, Bruce A.; Plimpton, Steven J.; Attaway, Stephen W.; Heinstein, Martin W.; Vaughan, Courtenay T.

    1998-01-01

    A process for predicting the structural performance of a mechanical system represents the mechanical system by a plurality of surface elements. The surface elements are grouped according to their location in the volume occupied by the mechanical system so that contacts between surface elements can be efficiently located. The process is well suited for efficient practice on multiprocessor computers.

  15. Predicting Introductory Programming Performance: A Multi-Institutional Multivariate Study

    ERIC Educational Resources Information Center

    Bergin, Susan; Reilly, Ronan

    2006-01-01

    A model for predicting student performance on introductory programming modules is presented. The model uses attributes identified in a study carried out at four third-level institutions in the Republic of Ireland. Four instruments were used to collect the data and over 25 attributes were examined. A data reduction technique was applied and a…

  16. Human transfer functions used to predict system performance parameters

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Automatic, parameter-tracking, model-matching technique compares the responses of a human operator with those of an analog computer model of a human operator to predict and analyze the performance of mechanical or electromechanical systems prior to construction. Transfer functions represent the input-output relation of an operator controlling a closed-loop system.

  17. Process for predicting structural performance of mechanical systems

    DOEpatents

    Gardner, D.R.; Hendrickson, B.A.; Plimpton, S.J.; Attaway, S.W.; Heinstein, M.W.; Vaughan, C.T.

    1998-05-19

    A process for predicting the structural performance of a mechanical system represents the mechanical system by a plurality of surface elements. The surface elements are grouped according to their location in the volume occupied by the mechanical system so that contacts between surface elements can be efficiently located. The process is well suited for efficient practice on multiprocessor computers. 12 figs.

  18. Prediction and Quantification of Individual Athletic Performance of Runners.

    PubMed

    Blythe, Duncan A J; Király, Franz J

    2016-01-01

    We present a novel, quantitative view on the human athletic performance of individual runners. We obtain a predictor for running performance, a parsimonious model and a training state summary consisting of three numbers by application of modern validation techniques and recent advances in machine learning to the thepowerof10 database of British runners' performances (164,746 individuals, 1,417,432 performances). Our predictor achieves an average prediction error (out-of-sample) of e.g. 3.6 min on elite Marathon performances and 0.3 seconds on 100 metres performances, and a lower error than the state-of-the-art in performance prediction (30% improvement, RMSE) over a range of distances. We are also the first to report on a systematic comparison of predictors for running performance. Our model has three parameters per runner, and three components which are the same for all runners. The first component of the model corresponds to a power law with exponent dependent on the runner which achieves a better goodness-of-fit than known power laws in the study of running. Many documented phenomena in quantitative sports science, such as the form of scoring tables, the success of existing prediction methods including Riegel's formula, the Purdy points scheme, the power law for world records performances and the broken power law for world record speeds may be explained on the basis of our findings in a unified way. We provide strong evidence that the three parameters per runner are related to physiological and behavioural parameters, such as training state, event specialization and age, which allows us to derive novel physiological hypotheses relating to athletic performance. We conjecture on this basis that our findings will be vital in exercise physiology, race planning, the study of aging and training regime design. PMID:27336162

  19. Prediction and Quantification of Individual Athletic Performance of Runners

    PubMed Central

    2016-01-01

    We present a novel, quantitative view on the human athletic performance of individual runners. We obtain a predictor for running performance, a parsimonious model and a training state summary consisting of three numbers by application of modern validation techniques and recent advances in machine learning to the thepowerof10 database of British runners’ performances (164,746 individuals, 1,417,432 performances). Our predictor achieves an average prediction error (out-of-sample) of e.g. 3.6 min on elite Marathon performances and 0.3 seconds on 100 metres performances, and a lower error than the state-of-the-art in performance prediction (30% improvement, RMSE) over a range of distances. We are also the first to report on a systematic comparison of predictors for running performance. Our model has three parameters per runner, and three components which are the same for all runners. The first component of the model corresponds to a power law with exponent dependent on the runner which achieves a better goodness-of-fit than known power laws in the study of running. Many documented phenomena in quantitative sports science, such as the form of scoring tables, the success of existing prediction methods including Riegel’s formula, the Purdy points scheme, the power law for world records performances and the broken power law for world record speeds may be explained on the basis of our findings in a unified way. We provide strong evidence that the three parameters per runner are related to physiological and behavioural parameters, such as training state, event specialization and age, which allows us to derive novel physiological hypotheses relating to athletic performance. We conjecture on this basis that our findings will be vital in exercise physiology, race planning, the study of aging and training regime design. PMID:27336162

  20. Predicting Subcontractor Performance Using Web-Based Evolutionary Fuzzy Neural Networks

    PubMed Central

    2013-01-01

    Subcontractor performance directly affects project success. The use of inappropriate subcontractors may result in individual work delays, cost overruns, and quality defects throughout the project. This study develops web-based Evolutionary Fuzzy Neural Networks (EFNNs) to predict subcontractor performance. EFNNs are a fusion of Genetic Algorithms (GAs), Fuzzy Logic (FL), and Neural Networks (NNs). FL is primarily used to mimic high level of decision-making processes and deal with uncertainty in the construction industry. NNs are used to identify the association between previous performance and future status when predicting subcontractor performance. GAs are optimizing parameters required in FL and NNs. EFNNs encode FL and NNs using floating numbers to shorten the length of a string. A multi-cut-point crossover operator is used to explore the parameter and retain solution legality. Finally, the applicability of the proposed EFNNs is validated using real subcontractors. The EFNNs are evolved using 22 historical patterns and tested using 12 unseen cases. Application results show that the proposed EFNNs surpass FL and NNs in predicting subcontractor performance. The proposed approach improves prediction accuracy and reduces the effort required to predict subcontractor performance, providing field operators with web-based remote access to a reliable, scientific prediction mechanism. PMID:23864830

  1. Performance Study and CFD Predictions of a Ducted Fan System

    NASA Technical Reports Server (NTRS)

    Abrego, Anita I.; Chang, I-Chung; Bulaga, Robert W.; Rutkowski, Michael (Technical Monitor)

    2002-01-01

    An experimental investigation was completed in the NASA Ames 7 by 10-Foot Wind Tunnel to study the performance characteristics of a ducted fan. The goal of this effort is to study the effect of ducted fan geometry and utilize Computational Fluid Dynamics (CFD) analysis to provide a baseline for correlation. A 38-inch diameter, 10-inch chord duct with a five-bladed fixed-pitch fan was tested. Duct performance data were obtained in hover, vertical climb, and forward flight test conditions. This paper will present a description of the test, duct performance results and correlation with CFD predictions.

  2. Performance predictions for an SSME configuration with an enlarged throat

    NASA Technical Reports Server (NTRS)

    Nickerson, G. R.; Dang, L. D.

    1985-01-01

    The Two Dimensional Kinetics (TDK) computer program that was recently developed for NASA was used to predict the performance of a Large Throat Configuration of the Space Shuttle Main Engine (SSME). Calculations indicate that the current design SSME contains a shock wave that is induced by the nozzle wall shape. In the Large Throat design an even stronger shock wave is predicted. Because of the presence of this shock wave, earlier performance predictions that have neglected shock wave effects have been questioned. The JANNAF thrust chamber performance prediction procedures given in a reference were applied. The analysis includes the effects of two dimensional reacting flow with a shock wave. The effects of the boundary layer with a regenatively cooled wall are also included. A Purdue computer program was used to compute axially symmetric supersonic nozzle flows with an induced shock, but is restricted to flows with a constant ratio of specific heats. Thus, the TDK program was also run with ths assumption and the results of the two programs were compared.

  3. Predictions and Performance on the PACT Teaching Event: Case Studies of High and Low Performers

    ERIC Educational Resources Information Center

    Sandholtz, Judith Haymore

    2012-01-01

    In an earlier study, the author and her colleague explored the extent to which supervisors' perspectives about candidates' performance corresponded with outcomes from a summative performance assessment (Sandholtz & Shea, 2012). They specifically examined the relationship between university supervisors' predictions and candidates' performance on…

  4. Aquatic Exposure Predictions of Insecticide Field Concentrations Using a Multimedia Mass-Balance Model.

    PubMed

    Knäbel, Anja; Scheringer, Martin; Stehle, Sebastian; Schulz, Ralf

    2016-04-01

    Highly complex process-driven mechanistic fate and transport models and multimedia mass balance models can be used for the exposure prediction of pesticides in different environmental compartments. Generally, both types of models differ in spatial and temporal resolution. Process-driven mechanistic fate models are very complex, and calculations are time-intensive. This type of model is currently used within the European regulatory pesticide registration (FOCUS). Multimedia mass-balance models require fewer input parameters to calculate concentration ranges and the partitioning between different environmental media. In this study, we used the fugacity-based small-region model (SRM) to calculate predicted environmental concentrations (PEC) for 466 cases of insecticide field concentrations measured in European surface waters. We were able to show that the PECs of the multimedia model are more protective in comparison to FOCUS. In addition, our results show that the multimedia model results have a higher predictive power to simulate varying field concentrations at a higher level of field relevance. The adaptation of the model scenario to actual field conditions suggests that the performance of the SRM increases when worst-case conditions are replaced by real field data. Therefore, this study shows that a less complex modeling approach than that used in the regulatory risk assessment exhibits a higher level of protectiveness and predictiveness and that there is a need to develop and evaluate new ecologically relevant scenarios in the context of pesticide exposure modeling. PMID:26889709

  5. Prediction of Gas Lubricated Foil Journal Bearing Performance

    NASA Technical Reports Server (NTRS)

    Carpino, Marc; Talmage, Gita

    2003-01-01

    This report summarizes the progress in the first eight months of the project. The objectives of this research project are to theoretically predict the steady operating conditions and the rotor dynamic coefficients of gas foil journal bearings. The project is currently on or ahead of schedule with the development of a finite element code that predicts steady bearing performance characteristics such as film thickness, pressure, load, and drag. Graphical results for a typical bearing are presented in the report. Project plans for the next year are discussed.

  6. Predictive Measures of Locomotor Performance on an Unstable Walking Surface

    NASA Technical Reports Server (NTRS)

    Bloomberg, J. J.; Peters, B. T.; Mulavara, A. P.; Caldwell, E. E.; Batson, C. D.; De Dios, Y. E.; Gadd, N. E.; Goel, R.; Wood, S. J.; Cohen, H. S.; Oddsson, L. I.; Seidler, R. D.

    2016-01-01

    Locomotion requires integration of visual, vestibular, and somatosensory information to produce the appropriate motor output to control movement. The degree to which these sensory inputs are weighted and reorganized in discordant sensory environments varies by individual and may be predictive of the ability to adapt to novel environments. The goals of this project are to: 1) develop a set of predictive measures capable of identifying individual differences in sensorimotor adaptability, and 2) use this information to inform the design of training countermeasures designed to enhance the ability of astronauts to adapt to gravitational transitions improving balance and locomotor performance after a Mars landing and enhancing egress capability after a landing on Earth.

  7. Improving the performance of predictive process modeling for large datasets

    PubMed Central

    Finley, Andrew O.; Sang, Huiyan; Banerjee, Sudipto; Gelfand, Alan E.

    2009-01-01

    Advances in Geographical Information Systems (GIS) and Global Positioning Systems (GPS) enable accurate geocoding of locations where scientific data are collected. This has encouraged collection of large spatial datasets in many fields and has generated considerable interest in statistical modeling for location-referenced spatial data. The setting where the number of locations yielding observations is too large to fit the desired hierarchical spatial random effects models using Markov chain Monte Carlo methods is considered. This problem is exacerbated in spatial-temporal and multivariate settings where many observations occur at each location. The recently proposed predictive process, motivated by kriging ideas, aims to maintain the richness of desired hierarchical spatial modeling specifications in the presence of large datasets. A shortcoming of the original formulation of the predictive process is that it induces a positive bias in the non-spatial error term of the models. A modified predictive process is proposed to address this problem. The predictive process approach is knot-based leading to questions regarding knot design. An algorithm is designed to achieve approximately optimal spatial placement of knots. Detailed illustrations of the modified predictive process using multivariate spatial regression with both a simulated and a real dataset are offered. PMID:20016667

  8. Real-time Tsunami Inundation Prediction Using High Performance Computers

    NASA Astrophysics Data System (ADS)

    Oishi, Y.; Imamura, F.; Sugawara, D.

    2014-12-01

    Recently off-shore tsunami observation stations based on cabled ocean bottom pressure gauges are actively being deployed especially in Japan. These cabled systems are designed to provide real-time tsunami data before tsunamis reach coastlines for disaster mitigation purposes. To receive real benefits of these observations, real-time analysis techniques to make an effective use of these data are necessary. A representative study was made by Tsushima et al. (2009) that proposed a method to provide instant tsunami source prediction based on achieving tsunami waveform data. As time passes, the prediction is improved by using updated waveform data. After a tsunami source is predicted, tsunami waveforms are synthesized from pre-computed tsunami Green functions of linear long wave equations. Tsushima et al. (2014) updated the method by combining the tsunami waveform inversion with an instant inversion of coseismic crustal deformation and improved the prediction accuracy and speed in the early stages. For disaster mitigation purposes, real-time predictions of tsunami inundation are also important. In this study, we discuss the possibility of real-time tsunami inundation predictions, which require faster-than-real-time tsunami inundation simulation in addition to instant tsunami source analysis. Although the computational amount is large to solve non-linear shallow water equations for inundation predictions, it has become executable through the recent developments of high performance computing technologies. We conducted parallel computations of tsunami inundation and achieved 6.0 TFLOPS by using 19,000 CPU cores. We employed a leap-frog finite difference method with nested staggered grids of which resolution range from 405 m to 5 m. The resolution ratio of each nested domain was 1/3. Total number of grid points were 13 million, and the time step was 0.1 seconds. Tsunami sources of 2011 Tohoku-oki earthquake were tested. The inundation prediction up to 2 hours after the

  9. Estimation of Turbulent Wall Jet Velocity Fields for Noise Prediction

    NASA Astrophysics Data System (ADS)

    Nickels, Adam; Ukeiley, Lawrence; Reger, Robert; Cattafesta, Louis

    2015-11-01

    Estimation of the time-dependent turbulent velocity field of a planar wall jet based on discrete surface pressure measurements is performed using stochastic estimation in both the time and frequency domain. Temporally-resolved surface pressure measurements are measured simultaneously with planar Particle Image Velocimetry (PIV) snapshots, obtained at a relatively reduced rate. Proper Orthogonal Decomposition (POD) is then applied to both the surface pressure probes and the PIV snapshots, allowing for the isolation of portions of the wall pressure and velocity field signals that are well correlated. Using the time-varying pressure expansion coefficients as unconditional variables, velocity expansion coefficients are estimated and used to produce reconstructed estimates of the velocity field. Optimization in terms of number of unconditional probes employed, location of probes, and effects of PIV discretization are investigated with regards to the resulting estimates. Coupled with this analysis, Poisson's equation for fluctuating pressure is solved such that the necessary source terms of an acoustic analogy can be calculated for estimates of the far-field acoustics. Specifically in this work, the effects of using estimated velocity fields to solve for the hydrodynamic pressure and acoustic pressure will be studied.

  10. Temporal prediction errors modulate task-switching performance.

    PubMed

    Limongi, Roberto; Silva, Angélica M; Góngora-Costa, Begoña

    2015-01-01

    We have previously shown that temporal prediction errors (PEs, the differences between the expected and the actual stimulus' onset times) modulate the effective connectivity between the anterior cingulate cortex and the right anterior insular cortex (rAI), causing the activity of the rAI to decrease. The activity of the rAI is associated with efficient performance under uncertainty (e.g., changing a prepared behavior when a change demand is not expected), which leads to hypothesize that temporal PEs might disrupt behavior-change performance under uncertainty. This hypothesis has not been tested at a behavioral level. In this work, we evaluated this hypothesis within the context of task switching and concurrent temporal predictions. Our participants performed temporal predictions while observing one moving ball striking a stationary ball which bounced off with a variable temporal gap. Simultaneously, they performed a simple color comparison task. In some trials, a change signal made the participants change their behaviors. Performance accuracy decreased as a function of both the temporal PE and the delay. Explaining these results without appealing to ad hoc concepts such as "executive control" is a challenge for cognitive neuroscience. We provide a predictive coding explanation. We hypothesize that exteroceptive and proprioceptive minimization of PEs would converge in a fronto-basal ganglia network which would include the rAI. Both temporal gaps (or uncertainty) and temporal PEs would drive and modulate this network respectively. Whereas the temporal gaps would drive the activity of the rAI, the temporal PEs would modulate the endogenous excitatory connections of the fronto-striatal network. We conclude that in the context of perceptual uncertainty, the system is not able to minimize perceptual PE, causing the ongoing behavior to finalize and, in consequence, disrupting task switching. PMID:26379568

  11. Temporal prediction errors modulate task-switching performance

    PubMed Central

    Limongi, Roberto; Silva, Angélica M.; Góngora-Costa, Begoña

    2015-01-01

    We have previously shown that temporal prediction errors (PEs, the differences between the expected and the actual stimulus’ onset times) modulate the effective connectivity between the anterior cingulate cortex and the right anterior insular cortex (rAI), causing the activity of the rAI to decrease. The activity of the rAI is associated with efficient performance under uncertainty (e.g., changing a prepared behavior when a change demand is not expected), which leads to hypothesize that temporal PEs might disrupt behavior-change performance under uncertainty. This hypothesis has not been tested at a behavioral level. In this work, we evaluated this hypothesis within the context of task switching and concurrent temporal predictions. Our participants performed temporal predictions while observing one moving ball striking a stationary ball which bounced off with a variable temporal gap. Simultaneously, they performed a simple color comparison task. In some trials, a change signal made the participants change their behaviors. Performance accuracy decreased as a function of both the temporal PE and the delay. Explaining these results without appealing to ad hoc concepts such as “executive control” is a challenge for cognitive neuroscience. We provide a predictive coding explanation. We hypothesize that exteroceptive and proprioceptive minimization of PEs would converge in a fronto-basal ganglia network which would include the rAI. Both temporal gaps (or uncertainty) and temporal PEs would drive and modulate this network respectively. Whereas the temporal gaps would drive the activity of the rAI, the temporal PEs would modulate the endogenous excitatory connections of the fronto-striatal network. We conclude that in the context of perceptual uncertainty, the system is not able to minimize perceptual PE, causing the ongoing behavior to finalize and, in consequence, disrupting task switching. PMID:26379568

  12. A comprehensive performance evaluation on the prediction results of existing cooperative transcription factors identification algorithms

    PubMed Central

    2014-01-01

    Background Eukaryotic transcriptional regulation is known to be highly connected through the networks of cooperative transcription factors (TFs). Measuring the cooperativity of TFs is helpful for understanding the biological relevance of these TFs in regulating genes. The recent advances in computational techniques led to various predictions of cooperative TF pairs in yeast. As each algorithm integrated different data resources and was developed based on different rationales, it possessed its own merit and claimed outperforming others. However, the claim was prone to subjectivity because each algorithm compared with only a few other algorithms and only used a small set of performance indices for comparison. This motivated us to propose a series of indices to objectively evaluate the prediction performance of existing algorithms. And based on the proposed performance indices, we conducted a comprehensive performance evaluation. Results We collected 14 sets of predicted cooperative TF pairs (PCTFPs) in yeast from 14 existing algorithms in the literature. Using the eight performance indices we adopted/proposed, the cooperativity of each PCTFP was measured and a ranking score according to the mean cooperativity of the set was given to each set of PCTFPs under evaluation for each performance index. It was seen that the ranking scores of a set of PCTFPs vary with different performance indices, implying that an algorithm used in predicting cooperative TF pairs is of strength somewhere but may be of weakness elsewhere. We finally made a comprehensive ranking for these 14 sets. The results showed that Wang J's study obtained the best performance evaluation on the prediction of cooperative TF pairs in yeast. Conclusions In this study, we adopted/proposed eight performance indices to make a comprehensive performance evaluation on the prediction results of 14 existing cooperative TFs identification algorithms. Most importantly, these proposed indices can be easily applied to

  13. Roadmap Toward a Predictive Performance-based Commercial Energy Code

    SciTech Connect

    Rosenberg, Michael I.; Hart, Philip R.

    2014-10-01

    Energy codes have provided significant increases in building efficiency over the last 38 years, since the first national energy model code was published in late 1975. The most commonly used path in energy codes, the prescriptive path, appears to be reaching a point of diminishing returns. The current focus on prescriptive codes has limitations including significant variation in actual energy performance depending on which prescriptive options are chosen, a lack of flexibility for designers and developers, and the inability to handle control optimization that is specific to building type and use. This paper provides a high level review of different options for energy codes, including prescriptive, prescriptive packages, EUI Target, outcome-based, and predictive performance approaches. This paper also explores a next generation commercial energy code approach that places a greater emphasis on performance-based criteria. A vision is outlined to serve as a roadmap for future commercial code development. That vision is based on code development being led by a specific approach to predictive energy performance combined with building specific prescriptive packages that are designed to be both cost-effective and to achieve a desired level of performance. Compliance with this new approach can be achieved by either meeting the performance target as demonstrated by whole building energy modeling, or by choosing one of the prescriptive packages.

  14. The Rigors of Predictive Validation: Some Comments on "A Job Learning Approach to Performance Prediction"

    ERIC Educational Resources Information Center

    Cohen, Stephen L.; Penner, Louis A.

    1976-01-01

    In a recent article in this journal (EJ 130 391) Siegel and Bergman described a "miniature job training and evaluation" approach to performance prediction. This research highlights their methodology's strengths and weaknesses in light of standard procedures recommended in developing any set of predictors. (Author/RK)

  15. Contextual predictability enhances reading performance in patients with schizophrenia.

    PubMed

    Fernández, Gerardo; Guinjoan, Salvador; Sapognikoff, Marcelo; Orozco, David; Agamennoni, Osvaldo

    2016-07-30

    In the present work we analyzed fixation duration in 40 healthy individuals and 18 patients with chronic, stable SZ during reading of regular sentences and proverbs. While they read, their eye movements were recorded. We used lineal mixed models to analyze fixation durations. The predictability of words N-1, N, and N+1 exerted a strong influence on controls and SZ patients. The influence of the predictabilities of preceding, current, and upcoming words on SZ was clearly reduced for proverbs in comparison to regular sentences. Both controls and SZ readers were able to use highly predictable fixated words for an easier reading. Our results suggest that SZ readers might compensate attentional and working memory deficiencies by using stored information of familiar texts for enhancing their reading performance. The predictabilities of words in proverbs serve as task-appropriate cues that are used by SZ readers. To the best of our knowledge, this is the first study using eyetracking for measuring how patients with SZ process well-defined words embedded in regular sentences and proverbs. Evaluation of the resulting changes in fixation durations might provide a useful tool for understanding how SZ patients could enhance their reading performance. PMID:27236087

  16. Computational prediction of isolated performance of an axisymmetric nozzle at Mach number 0.90

    NASA Technical Reports Server (NTRS)

    Carlson, John R.

    1994-01-01

    An improved ability to predict external propulsive performance was incorporated into the three-dimensional Navier-Stokes code PAB3D. The improvements are the ability to account for skin friction and external pressure forces. Performance parameters for two axisymmetric supersonic cruise nozzle configurations were calculated to test the improved methodology. Internal and external flow-field regions were computed using a two-equation kappa-epsilon turbulent viscous-stress model. The computed thrust-minus-drag ratios were within 1 percent of the absolute level of experimental data and the trends of data were predicted accurately. The predicted trend of integrated nozzle pressure drag matched the trend of the integrated experimental pressure drag over a range of nozzle pressure ratios, but absolute drag levels were not accurately predicted.

  17. Prediction of incidence and surface roughness effects on turbine performance

    NASA Technical Reports Server (NTRS)

    Boyle, R. J.

    1993-01-01

    The results of a Navier-Stokes analysis for predicting the change in turbine efficiency due to a change in either incidence or surface roughness is discussed. It was experimentally determined by Boynton, Tabibzadeh, and Hudson that polishing the SSME high pressure fuel turbine blades improved turbine efficiency by about 2 points over a wide range of operating conditions. These conditions encompassed the range of incidence seen by the turbine blading during flight. It is also necessary to be able to predict turbine performance at various operating points for future rocket turbopump applications. The code RVCQ3D, developed by Rod Chima, was used to determine the effects of changes in incidence angle on turbine blade row efficiency. The midspan Navier-Stokes results were used in conjunction with an inviscid flow analysis code to predict the efficiency of the two stage SSME over a wide range of operating conditions for smooth and rough turbine blades. The use of the Navier-Stokes analysis to predict changes in turbine efficiency due to variation in incidence angles was found to be superior to other incidence loss correlations available in the literature. The sensitivity of the Navier-Stokes results to grid parameters is discussed. The effects of the surface roughness were accounted for using the Cebeci-Chang rough wall turbulence model. This model was implemented in the code RVCQ3D. The implementation of this model for predicting the change in efficiency is also discussed.

  18. The ensemble performance index: an improved measure for assessing ensemble pose prediction performance.

    PubMed

    Korb, Oliver; McCabe, Patrick; Cole, Jason

    2011-11-28

    We present a theoretical study on the performance of ensemble docking methodologies considering multiple protein structures. We perform a theoretical analysis of pose prediction experiments which is completely unbiased, as we make no assumptions about specific scoring functions, search paradigms, protein structures, or ligand data sets. We introduce a novel interpretable measure, the ensemble performance index (EPI), for the assessment of scoring performance in ensemble docking, which will be applied to simulated and real data sets. PMID:21962010

  19. Planar Near-Field Phase Retrieval Using GPUs for Accurate THz Far-Field Prediction

    NASA Astrophysics Data System (ADS)

    Junkin, Gary

    2013-04-01

    With a view to using Phase Retrieval to accurately predict Terahertz antenna far-field from near-field intensity measurements, this paper reports on three fundamental advances that achieve very low algorithmic error penalties. The first is a new Gaussian beam analysis that provides accurate initial complex aperture estimates including defocus and astigmatic phase errors, based only on first and second moment calculations. The second is a powerful noise tolerant near-field Phase Retrieval algorithm that combines Anderson's Plane-to-Plane (PTP) with Fienup's Hybrid-Input-Output (HIO) and Successive Over-Relaxation (SOR) to achieve increased accuracy at reduced scan separations. The third advance employs teraflop Graphical Processing Units (GPUs) to achieve practically real time near-field phase retrieval and to obtain the optimum aperture constraint without any a priori information.

  20. A novel prediction method about single components of analog circuits based on complex field modeling.

    PubMed

    Zhou, Jingyu; Tian, Shulin; Yang, Chenglin

    2014-01-01

    Few researches pay attention to prediction about analog circuits. The few methods lack the correlation with circuit analysis during extracting and calculating features so that FI (fault indicator) calculation often lack rationality, thus affecting prognostic performance. To solve the above problem, this paper proposes a novel prediction method about single components of analog circuits based on complex field modeling. Aiming at the feature that faults of single components hold the largest number in analog circuits, the method starts with circuit structure, analyzes transfer function of circuits, and implements complex field modeling. Then, by an established parameter scanning model related to complex field, it analyzes the relationship between parameter variation and degeneration of single components in the model in order to obtain a more reasonable FI feature set via calculation. According to the obtained FI feature set, it establishes a novel model about degeneration trend of analog circuits' single components. At last, it uses particle filter (PF) to update parameters for the model and predicts remaining useful performance (RUP) of analog circuits' single components. Since calculation about the FI feature set is more reasonable, accuracy of prediction is improved to some extent. Finally, the foregoing conclusions are verified by experiments. PMID:25147853

  1. Prediction of the far field noise from wind energy farms

    NASA Technical Reports Server (NTRS)

    Shepherd, K. P.; Hubbard, H. H.

    1986-01-01

    The basic physical factors involved in making predictions of wind turbine noise and an approach which allows for differences in the machines, the wind energy farm configurations and propagation conditions are reviewed. Example calculations to illustrate the sensitivity of the radiated noise to such variables as machine size, spacing and numbers, and such atmosphere variables as absorption and wind direction are presented. It is found that calculated far field distances to particular sound level contours are greater for lower values of atmospheric absorption, for a larger total number of machines, for additional rows of machines and for more powerful machines. At short and intermediate distances, higher sound pressure levels are calculated for closer machine spacings, for more powerful machines, for longer row lengths and for closer row spacings.

  2. Field Differentiation and LOGO Performance among Zimbabwean Schoolgirls.

    ERIC Educational Resources Information Center

    Wilson, David; And Others

    1990-01-01

    Examines the relationship of field differences to LOGO performance among Black and White Zimbabwean schoolgirls. Finds field independence and performance were related among both groups and remained significant when the intelligence variant was eliminated. Suggests field differentiation is an important concomitant of LOGO competence and simply not…

  3. Gatekeeping in Field Performance: Is Grade Inflation a Given?

    ERIC Educational Resources Information Center

    Sowbel, Lynda R.

    2011-01-01

    This field note presents the results of a pilot study that explored the use of a new non-numerically rated field performance tool, a vignette matching measure for MSW students. Evaluation of performance in the field has proved to be a difficult task because few if any measures, including competency-based measures, have known levels of reliability…

  4. Recent Progress Towards Predicting Aircraft Ground Handling Performance

    NASA Technical Reports Server (NTRS)

    Yager, T. J.; White, E. J.

    1981-01-01

    The significant progress which has been achieved in development of aircraft ground handling simulation capability is reviewed and additional improvements in software modeling identified. The problem associated with providing necessary simulator input data for adequate modeling of aircraft tire/runway friction behavior is discussed and efforts to improve this complex model, and hence simulator fidelity, are described. Aircraft braking performance data obtained on several wet runway surfaces is compared to ground vehicle friction measurements and, by use of empirically derived methods, good agreement between actual and estimated aircraft braking friction from ground vehilce data is shown. The performance of a relatively new friction measuring device, the friction tester, showed great promise in providing data applicable to aircraft friction performance. Additional research efforts to improve methods of predicting tire friction performance are discussed including use of an instrumented tire test vehicle to expand the tire friction data bank and a study of surface texture measurement techniques.

  5. Field Dependency and Performance in Mathematics

    ERIC Educational Resources Information Center

    Onwumere, Onyebuchi; Reid, Norman

    2014-01-01

    Mathematics is an important school subject but one which often poses problems for learners. It has been found that learners do not possess the cognitive capacity to handle understanding procedures, representations, concepts, and applications at the same time. while the extent of field dependency may hold the key to one way by which the working…

  6. Evaluation of PV Module Field Performance

    SciTech Connect

    Wohlgemuth, John; Silverman, Timothy; Miller, David C.; McNutt, Peter; Kempe, Michael; Deceglie, Michael

    2015-06-14

    This paper describes an effort to inspect and evaluate PV modules in order to determine what failure or degradation modes are occurring in field installations. This paper will report on the results of six site visits, including the Sacramento Municipal Utility District (SMUD) Hedge Array, Tucson Electric Power (TEP) Springerville, Central Florida Utility, Florida Solar Energy Center (FSEC), the TEP Solar Test Yard, and University of Toledo installations. The effort here makes use of a recently developed field inspection data collection protocol, and the results were input into a corresponding database. The results of this work have also been used to develop a draft of the IEC standard for climate and application specific accelerated stress testing beyond module qualification. TEP Solar Test Yard, and University of Toledo installations. The effort here makes use of a recently developed field inspection data collection protocol, and the results were input into a corresponding database. The results of this work have also been used to develop a draft of the IEC standard for climate and application specific accelerated stress testing beyond module qualification. TEP Solar Test Yard, and University of Toledo installations. The effort here makes use of a recently developed field inspection data collection protocol, and the results were input into a corresponding database. The results of this work have also been used to develop a draft of the IEC standard for climate and application specific accelerated stress testing beyond module qualification.

  7. Alkaline flood prediction studies, Ranger VII pilot, Wilmington Field, California

    SciTech Connect

    Mayer, E.H.; Breit, V.S.

    1982-01-01

    The paper discusses: (1) The design of a simulator to model alkaline displacement mechanisms and the current state-of-the-art understanding of in-situ caustic consumption. (2) Assimilation of laboratory core flood and rock consumption data. Use of this data in 1-D and 2-D limited area simulations, and a 3-D model of the entire pilot project. (3) Simulation studies of alkaline flood behavior in a small 2-D area of the field for various concentrations, slug sizes, long term consumption functions and two relative permeability adjustment mechanisms. (4) Scale up of 2-D simulation results, and their use in a 271 acre 1.097 x 10/sup 6/m/sup 2/), 7 layered 3-D model of the pilot. (5) Comparison of 3-D simulator results with initial field alkaline flood performance. (6) Recommended additional application of the simulator methods developed in this pilot and in other alkaline floods. 10 refs.

  8. Methods to improve neural network performance in daily flows prediction

    NASA Astrophysics Data System (ADS)

    Wu, C. L.; Chau, K. W.; Li, Y. S.

    2009-06-01

    SummaryIn this paper, three data-preprocessing techniques, moving average (MA), singular spectrum analysis (SSA), and wavelet multi-resolution analysis (WMRA), were coupled with artificial neural network (ANN) to improve the estimate of daily flows. Six models, including the original ANN model without data preprocessing, were set up and evaluated. Five new models were ANN-MA, ANN-SSA1, ANN-SSA2, ANN-WMRA1, and ANN-WMRA2. The ANN-MA was derived from the raw ANN model combined with the MA. The ANN-SSA1, ANN-SSA2, ANN-WMRA1 and ANN-WMRA2 were generated by using the original ANN model coupled with SSA and WMRA in terms of two different means. Two daily flow series from different watersheds in China (Lushui and Daning) were used in six models for three prediction horizons (i.e., 1-, 2-, and 3-day-ahead forecast). The poor performance on ANN forecast models was mainly due to the existence of the lagged prediction. The ANN-MA, among six models, performed best and eradicated the lag effect. The performances from the ANN-SSA1 and ANN-SSA2 were similar, and the performances from the ANN-WMRA1 and ANN-WMRA2 were also similar. However, the models based on the SSA presented better performance than the models based on the WMRA at all forecast horizons, which meant that the SSA is more effective than the WMRA in improving the ANN performance in the current study. Based on an overall consideration including the model performance and the complexity of modeling, the ANN-MA model was optimal, then the ANN model coupled with SSA, and finally the ANN model coupled with WMRA.

  9. Probabilistic Analysis of Gas Turbine Field Performance

    NASA Technical Reports Server (NTRS)

    Gorla, Rama S. R.; Pai, Shantaram S.; Rusick, Jeffrey J.

    2002-01-01

    A gas turbine thermodynamic cycle was computationally simulated and probabilistically evaluated in view of the several uncertainties in the performance parameters, which are indices of gas turbine health. Cumulative distribution functions and sensitivity factors were computed for the overall thermal efficiency and net specific power output due to the thermodynamic random variables. These results can be used to quickly identify the most critical design variables in order to optimize the design, enhance performance, increase system availability and make it cost effective. The analysis leads to the selection of the appropriate measurements to be used in the gas turbine health determination and to the identification of both the most critical measurements and parameters. Probabilistic analysis aims at unifying and improving the control and health monitoring of gas turbine aero-engines by increasing the quality and quantity of information available about the engine's health and performance.

  10. Predictive factors for masticatory performance in Duchenne muscular dystrophy.

    PubMed

    van Bruggen, H W; van de Engel-Hoek, L; Steenks, M H; Bronkhorst, E M; Creugers, N H J; de Groot, I J M; Kalaykova, S I

    2014-08-01

    Patients with Duchenne muscular dystrophy (DMD) report masticatory and swallowing problems. Such problems may cause complications such as choking, and feeling of food sticking in the throat. We investigated whether masticatory performance in DMD is objectively impaired, and explored predictive factors for compromised mastication. Twenty-three patients and 23 controls filled out two questionnaires about mandibular function, and underwent a clinical examination of the masticatory system and measurements of anterior bite force and masticatory performance. In the patients, moreover, quantitative ultrasound of the tongue and motor function measurement was performed. The patients were categorized into ambulatory stage (early or late), early non-ambulatory stage, or late non-ambulatory stage. Masticatory performance, anterior bite force and occlusal contacts were all reduced in the patient group compared to the controls (all p < 0.001). Mastication abnormalities were present early in the disease process prior to a reduction of motor function measurement. The early non-ambulatory and late non-ambulatory stage groups showed less masticatory performance compared to the ambulatory stage group (p < 0.028 and p < 0.010, respectively). Multiple linear regression analysis revealed that stage of the disease was the strongest independent risk factor for the masticatory performance (R(2) = 0.52). Anterior bite force, occlusal contacts and masticatory performance in DMD are severely reduced. PMID:24969130

  11. Fuzzy regression modeling for tool performance prediction and degradation detection.

    PubMed

    Li, X; Er, M J; Lim, B S; Zhou, J H; Gan, O P; Rutkowski, L

    2010-10-01

    In this paper, the viability of using Fuzzy-Rule-Based Regression Modeling (FRM) algorithm for tool performance and degradation detection is investigated. The FRM is developed based on a multi-layered fuzzy-rule-based hybrid system with Multiple Regression Models (MRM) embedded into a fuzzy logic inference engine that employs Self Organizing Maps (SOM) for clustering. The FRM converts a complex nonlinear problem to a simplified linear format in order to further increase the accuracy in prediction and rate of convergence. The efficacy of the proposed FRM is tested through a case study - namely to predict the remaining useful life of a ball nose milling cutter during a dry machining process of hardened tool steel with a hardness of 52-54 HRc. A comparative study is further made between four predictive models using the same set of experimental data. It is shown that the FRM is superior as compared with conventional MRM, Back Propagation Neural Networks (BPNN) and Radial Basis Function Networks (RBFN) in terms of prediction accuracy and learning speed. PMID:20945519

  12. TankSIM: A Cryogenic Tank Performance Prediction Program

    NASA Technical Reports Server (NTRS)

    Bolshinskiy, L. G.; Hedayat, A.; Hastings, L. J.; Moder, J. P.; Schnell, A. R.; Sutherlin, S. G.

    2015-01-01

    Accurate prediction of the thermodynamic state of the cryogenic propellants in launch vehicle tanks is necessary for mission planning and successful execution. Cryogenic propellant storage and transfer in space environments requires that tank pressure be controlled. The pressure rise rate is determined by the complex interaction of external heat leak, fluid temperature stratification, and interfacial heat and mass transfer. If the required storage duration of a space mission is longer than the period in which the tank pressure reaches its allowable maximum, an appropriate pressure control method must be applied. Therefore, predictions of the pressurization rate and performance of pressure control techniques in cryogenic tanks are required for development of cryogenic fluid long-duration storage technology and planning of future space exploration missions. This paper describes an analytical tool, Tank System Integrated Model (TankSIM), which can be used for modeling pressure control and predicting the behavior of cryogenic propellant for long-term storage for future space missions. It is written in the FORTRAN 90 language and can be compiled with any Visual FORTRAN compiler. A thermodynamic vent system (TVS) is used to achieve tank pressure control. Utilizing TankSIM, the following processes can be modeled: tank self-pressurization, boiloff, ullage venting, and mixing. Details of the TankSIM program and comparisons of its predictions with test data for liquid hydrogen and liquid methane will be presented in the final paper.

  13. Foraging Ecology Predicts Learning Performance in Insectivorous Bats

    PubMed Central

    Clarin, Theresa M. A.; Ruczyński, Ireneusz; Page, Rachel A.

    2013-01-01

    Bats are unusual among mammals in showing great ecological diversity even among closely related species and are thus well suited for studies of adaptation to the ecological background. Here we investigate whether behavioral flexibility and simple- and complex-rule learning performance can be predicted by foraging ecology. We predict faster learning and higher flexibility in animals hunting in more complex, variable environments than in animals hunting in more simple, stable environments. To test this hypothesis, we studied three closely related insectivorous European bat species of the genus Myotis that belong to three different functional groups based on foraging habitats: M. capaccinii, an open water forager, M. myotis, a passive listening gleaner, and M. emarginatus, a clutter specialist. We predicted that M. capaccinii would show the least flexibility and slowest learning reflecting its relatively unstructured foraging habitat and the stereotypy of its natural foraging behavior, while the other two species would show greater flexibility and more rapid learning reflecting the complexity of their natural foraging tasks. We used a purposefully unnatural and thus species-fair crawling maze to test simple- and complex-rule learning, flexibility and re-learning performance. We found that M. capaccinii learned a simple rule as fast as the other species, but was slower in complex rule learning and was less flexible in response to changes in reward location. We found no differences in re-learning ability among species. Our results corroborate the hypothesis that animals’ cognitive skills reflect the demands of their ecological niche. PMID:23755146

  14. Performance and wake predictions of HAWTs in wind farms

    SciTech Connect

    Leclerc, C.; Masson, C.; Paraschivoiu, I.

    1997-12-31

    The present contribution proposes and describes a promising way towards performance prediction of an arbitrary array of turbines. It is based on the solution of the time-averaged, steady-state, incompressible Navier-Stokes equations with an appropriate turbulence closure model. The turbines are represented by distributions of momentum sources in the Navier-Stokes equations. In this paper, the applicability and viability of the proposed methodology is demonstrated using an axisymmetric implementation. The k-{epsilon} model has been chosen for the closure of the time-averaged, turbulent flow equations and the properties of the incident flow correspond to those of a neutral atmospheric boundary layer. The proposed mathematical model is solved using a Control-Volume Finite Element Method (CVFEM). Detailed results have been obtained using the proposed method for an isolated wind turbine and for two turbines one behind another. In the case of an isolated turbine, accurate wake velocity deficit predictions are obtained and an increase in power due to atmospheric turbulence is found in agreement with measurements. In the case of two turbines, the proposed methodology provides an appropriate modelling of the wind-turbine wake and a realistic prediction of the performance degradation of the downstream turbine.

  15. Predicting performance in competitive apnoea diving. Part I: static apnoea.

    PubMed

    Schagatay, Erika

    2009-06-01

    Ever since the first deep diving competitions were organized, there has been debate about when the ultimate limits of human apnoeic performance will be reached, and which factors will determine these limits. Divers have thus far surpassed all former predictions by physiologists in depth and time. The common factor for all competitive apnoea disciplines is apnoeic duration, which can be prolonged by any means that increase total gas storage or tolerance to asphyxia, or reduce metabolic rate. These main factors can be broken down further into several physiological or psychophysiological factors, which are identified in this review. Like in other sports, the main aim in competitive apnoea is to extend human performance beyond the known limits. While a beginner may extend apnoeic duration by getting closer to his or her personal limit, the elite diver can only extend the duration further by pushing the individual physiological limit further by training. In order to achieve this, it is essential to identify the performance predicting factors of apnoea sports and which factors can be affected by training, work that has only just begun. This is the first of two papers reviewing the main factors predicting performance in competitive apnoea diving, which focuses on static apnoea, while the following paper will review dynamic distance and depth disciplines. Great improvements have been made in all diving disciplines in recent years and the 10-minute barrier in resting 'static apnoea' has been broached. Despite this, current training methods and the strategies employed suggest that duration can be prolonged still further, and divers themselves suggest the ultimate limit will be 15 minutes, which appears physiologically possible, for example, with further development of techniques to reduce metabolic rate. PMID:22753202

  16. Development of a massively parallel parachute performance prediction code

    SciTech Connect

    Peterson, C.W.; Strickland, J.H.; Wolfe, W.P.; Sundberg, W.D.; McBride, D.D.

    1997-04-01

    The Department of Energy has given Sandia full responsibility for the complete life cycle (cradle to grave) of all nuclear weapon parachutes. Sandia National Laboratories is initiating development of a complete numerical simulation of parachute performance, beginning with parachute deployment and continuing through inflation and steady state descent. The purpose of the parachute performance code is to predict the performance of stockpile weapon parachutes as these parachutes continue to age well beyond their intended service life. A new massively parallel computer will provide unprecedented speed and memory for solving this complex problem, and new software will be written to treat the coupled fluid, structure and trajectory calculations as part of a single code. Verification and validation experiments have been proposed to provide the necessary confidence in the computations.

  17. Advanced electric field computation for RF sheaths prediction with TOPICA

    NASA Astrophysics Data System (ADS)

    Milanesio, Daniele; Maggiora, Riccardo

    2012-10-01

    The design of an Ion Cyclotron (IC) launcher is not only driven by its coupling properties, but also by its capability of maintaining low parallel electric fields in front of it, in order to provide good power transfer to plasma and to reduce the impurities production. However, due to the impossibility to verify the antenna performances before the starting of the operations, advanced numerical simulation tools are the only alternative to carry out a proper antenna design. With this in mind, it should be clear that the adoption of a code, such as TOPICA [1], able to precisely take into account a realistic antenna geometry and an accurate plasma description, is extremely important to achieve these goals. Because of the recently introduced features that allow to compute the electric field distribution everywhere inside the antenna enclosure and in the plasma column, the TOPICA code appears to be the only alternative to understand which elements may have a not negligible impact on the antenna design and then to suggest further optimizations in order to mitigate RF potentials. The present work documents the evaluation of the electric field map from actual antennas, like the Tore Supra Q5 and the JET A2 launchers, and the foreseen ITER IC antenna. [4pt] [1] D. Milanesio et al., Nucl. Fusion 49, 115019 (2009).

  18. Phase errors and predicted spectral performance of a prototype undulator

    SciTech Connect

    Dejus, R.J.; Vassrman, I.; Moog, E.R.; Gluskin, E.

    1994-08-01

    A prototype undulator has been used to study different magnetic end-configurations and shimming techniques for straightening the beam trajectory. Field distributions obtained by Hall probe measurements were analyzed in terms of trajectory, phase errors, and on-axis brightness for the purpose of correlating predicted spectral intensity with the calculated phase errors. Two device configurations were analyzed. One configuration had a full-strength first magnet at each end and the next-to-last pole was recessed to make the trajectory through the middle of the undulator parallel to the undulator axis. For the second configuration, the first permanent magnet at each end was replaced by a half-strength magnet to reduce the trajectory displacement and the next-to-last pole was adjusted appropriately, and shims were added to straighten the trajectory. Random magnetic field errors can cause trajectory deviations that will affect the optimum angle for viewing the emitted radiation, and care must be taken to select the appropriate angle when calculating the phase errors. This angle may be calculated from the average trajectory angle evaluated at the location of the poles. For the second configuration, we find an rms phase error of less than 3{degrees} and predict 87% of the ideal value of the on-axis brightness for the third harmonic. We have also analyzed the gap dependence of the phase errors and spectral brightness and have found that the rms phase error remain small at all gap settings.

  19. Predicting introductory programming performance: A multi-institutional multivariate study

    NASA Astrophysics Data System (ADS)

    Bergin, Susan; Reilly, Ronan

    2006-12-01

    A model for predicting student performance on introductory programming modules is presented. The model uses attributes identified in a study carried out at four third-level institutions in the Republic of Ireland. Four instruments were used to collect the data and over 25 attributes were examined. A data reduction technique was applied and a logistic regression model using 10-fold stratified cross validation was developed. The model used three attributes: Leaving Certificate Mathematics result (final mathematics examination at second level), number of hours playing computer games while taking the module and programming self-esteem. Prediction success was significant with 80% of students correctly classified. The model also works well on a per-institution level. A discussion on the implications of the model is provided and future work is outlined.

  20. A high performance field-reversed configuration

    SciTech Connect

    Binderbauer, M. W.; Tajima, T.; Steinhauer, L. C.; Garate, E.; Tuszewski, M.; Smirnov, A.; Gota, H.; Barnes, D.; Deng, B. H.; Thompson, M. C.; Trask, E.; Yang, X.; Putvinski, S.; Rostoker, N.; Andow, R.; Aefsky, S.; Bolte, N.; Bui, D. Q.; Ceccherini, F.; Clary, R.; and others

    2015-05-15

    Conventional field-reversed configurations (FRCs), high-beta, prolate compact toroids embedded in poloidal magnetic fields, face notable stability and confinement concerns. These can be ameliorated by various control techniques, such as introducing a significant fast ion population. Indeed, adding neutral beam injection into the FRC over the past half-decade has contributed to striking improvements in confinement and stability. Further, the addition of electrically biased plasma guns at the ends, magnetic end plugs, and advanced surface conditioning led to dramatic reductions in turbulence-driven losses and greatly improved stability. Together, these enabled the build-up of a well-confined and dominant fast-ion population. Under such conditions, highly reproducible, macroscopically stable hot FRCs (with total plasma temperature of ∼1 keV) with record lifetimes were achieved. These accomplishments point to the prospect of advanced, beam-driven FRCs as an intriguing path toward fusion reactors. This paper reviews key results and presents context for further interpretation.

  1. A high performance field-reversed configurationa)

    NASA Astrophysics Data System (ADS)

    Binderbauer, M. W.; Tajima, T.; Steinhauer, L. C.; Garate, E.; Tuszewski, M.; Schmitz, L.; Guo, H. Y.; Smirnov, A.; Gota, H.; Barnes, D.; Deng, B. H.; Thompson, M. C.; Trask, E.; Yang, X.; Putvinski, S.; Rostoker, N.; Andow, R.; Aefsky, S.; Bolte, N.; Bui, D. Q.; Ceccherini, F.; Clary, R.; Cheung, A. H.; Conroy, K. D.; Dettrick, S. A.; Douglass, J. D.; Feng, P.; Galeotti, L.; Giammanco, F.; Granstedt, E.; Gupta, D.; Gupta, S.; Ivanov, A. A.; Kinley, J. S.; Knapp, K.; Korepanov, S.; Hollins, M.; Magee, R.; Mendoza, R.; Mok, Y.; Necas, A.; Primavera, S.; Onofri, M.; Osin, D.; Rath, N.; Roche, T.; Romero, J.; Schroeder, J. H.; Sevier, L.; Sibley, A.; Song, Y.; Van Drie, A. D.; Walters, J. K.; Waggoner, W.; Yushmanov, P.; Zhai, K.

    2015-05-01

    Conventional field-reversed configurations (FRCs), high-beta, prolate compact toroids embedded in poloidal magnetic fields, face notable stability and confinement concerns. These can be ameliorated by various control techniques, such as introducing a significant fast ion population. Indeed, adding neutral beam injection into the FRC over the past half-decade has contributed to striking improvements in confinement and stability. Further, the addition of electrically biased plasma guns at the ends, magnetic end plugs, and advanced surface conditioning led to dramatic reductions in turbulence-driven losses and greatly improved stability. Together, these enabled the build-up of a well-confined and dominant fast-ion population. Under such conditions, highly reproducible, macroscopically stable hot FRCs (with total plasma temperature of ˜1 keV) with record lifetimes were achieved. These accomplishments point to the prospect of advanced, beam-driven FRCs as an intriguing path toward fusion reactors. This paper reviews key results and presents context for further interpretation.

  2. Lessons from application of the UNRES force field to predictions of structures of CASP10 targets

    PubMed Central

    He, Yi; Mozolewska, Magdalena A.; Krupa, Paweł; Sieradzan, Adam K.; Wirecki, Tomasz K.; Liwo, Adam; Kachlishvili, Khatuna; Rackovsky, Shalom; Jagieła, Dawid; Ślusarz, Rafał; Czaplewski, Cezary R.; Ołdziej, Stanisław; Scheraga, Harold A.

    2013-01-01

    The performance of the physics-based protocol, whose main component is the United Residue (UNRES) physics-based coarse-grained force field, developed in our laboratory for the prediction of protein structure from amino acid sequence, is illustrated. Candidate models are selected, based on probabilities of the conformational families determined by multiplexed replica-exchange simulations, from the 10th Community Wide Experiment on the Critical Assessment of Techniques for Protein Structure Prediction (CASP10). For target T0663, classified as a new fold, which consists of two domains homologous to those of known proteins, UNRES predicted the correct symmetry of packing, in which the domains are rotated with respect to each other by 180° in the experimental structure. By contrast, models obtained by knowledge-based methods, in which each domain is modeled very accurately but not rotated, resulted in incorrect packing. Two UNRES models of this target were featured by the assessors. Correct domain packing was also predicted by UNRES for the homologous target T0644, which has a similar structure to that of T0663, except that the two domains are not rotated. Predictions for two other targets, T0668 and T0684_D2, are among the best ones by global distance test score. These results suggest that our physics-based method has substantial predictive power. In particular, it has the ability to predict domain–domain orientations, which is a significant advance in the state of the art. PMID:23980156

  3. The Influence of Viscous Effects on Ice Accretion Prediction and Airfoil Performance Predictions

    NASA Technical Reports Server (NTRS)

    Kreeger, Richard E.; Wright, William B.

    2005-01-01

    A computational study was conducted to evaluate the effectiveness of using a viscous flow solution in an ice accretion code and the resulting accuracy of aerodynamic performance prediction. Ice shapes were obtained for one single-element and one multi-element airfoil using both potential flow and Navier-Stokes flowfields in the LEWICE ice accretion code. Aerodynamics were then calculated using a Navier-Stokes flow solver.

  4. System performance predictions for Space Station Freedom's electric power system

    NASA Technical Reports Server (NTRS)

    Kerslake, Thomas W.; Hojnicki, Jeffrey S.; Green, Robert D.; Follo, Jeffrey C.

    1993-01-01

    Space Station Freedom Electric Power System (EPS) capability to effectively deliver power to housekeeping and user loads continues to strongly influence Freedom's design and planned approaches for assembly and operations. The EPS design consists of silicon photovoltaic (PV) arrays, nickel-hydrogen batteries, and direct current power management and distribution hardware and cabling. To properly characterize the inherent EPS design capability, detailed system performance analyses must be performed for early stages as well as for the fully assembled station up to 15 years after beginning of life. Such analyses were repeatedly performed using the FORTRAN code SPACE (Station Power Analysis for Capability Evaluation) developed at the NASA Lewis Research Center over a 10-year period. SPACE combines orbital mechanics routines, station orientation/pointing routines, PV array and battery performance models, and a distribution system load-flow analysis to predict EPS performance. Time-dependent, performance degradation, low earth orbit environmental interactions, and EPS architecture build-up are incorporated in SPACE. Results from two typical SPACE analytical cases are presented: (1) an electric load driven case and (2) a maximum EPS capability case.

  5. Predicting the protein targets for athletic performance-enhancing substances

    PubMed Central

    2013-01-01

    Background The World Anti-Doping Agency (WADA) publishes the Prohibited List, a manually compiled international standard of substances and methods prohibited in-competition, out-of-competition and in particular sports. It would be ideal to be able to identify all substances that have one or more performance-enhancing pharmacological actions in an automated, fast and cost effective way. Here, we use experimental data derived from the ChEMBL database (~7,000,000 activity records for 1,300,000 compounds) to build a database model that takes into account both structure and experimental information, and use this database to predict both on-target and off-target interactions between these molecules and targets relevant to doping in sport. Results The ChEMBL database was screened and eight well populated categories of activities (Ki, Kd, EC50, ED50, activity, potency, inhibition and IC50) were used for a rule-based filtering process to define the labels “active” or “inactive”. The “active” compounds for each of the ChEMBL families were thereby defined and these populated our bioactivity-based filtered families. A structure-based clustering step was subsequently performed in order to split families with more than one distinct chemical scaffold. This produced refined families, whose members share both a common chemical scaffold and bioactivity against a common target in ChEMBL. Conclusions We have used the Parzen-Rosenblatt machine learning approach to test whether compounds in ChEMBL can be correctly predicted to belong to their appropriate refined families. Validation tests using the refined families gave a significant increase in predictivity compared with the filtered or with the original families. Out of 61,660 queries in our Monte Carlo cross-validation, belonging to 19,639 refined families, 41,300 (66.98%) had the parent family as the top prediction and 53,797 (87.25%) had the parent family in the top four hits. Having thus validated our approach, we used

  6. Neighborhood Integration and Connectivity Predict Cognitive Performance and Decline

    PubMed Central

    Watts, Amber; Ferdous, Farhana; Moore, Keith Diaz; Burns, Jeffrey M.

    2015-01-01

    Objective Neighborhood characteristics may be important for promoting walking, but little research has focused on older adults, especially those with cognitive impairment. We evaluated the role of neighborhood characteristics on cognitive function and decline over a 2-year period adjusting for measures of walking. Method In a study of 64 older adults with and without mild Alzheimer's disease (AD), we evaluated neighborhood integration and connectivity using geographical information systems data and space syntax analysis. In multiple regression analyses, we used these characteristics to predict 2-year declines in factor analytically derived cognitive scores (attention, verbal memory, mental status) adjusting for age, sex, education, and self-reported walking. Results Neighborhood integration and connectivity predicted cognitive performance at baseline, and changes in cognitive performance over 2 years. The relationships between neighborhood characteristics and cognitive performance were not fully explained by self-reported walking. Discussion Clearer definitions of specific neighborhood characteristics associated with walkability are needed to better understand the mechanisms by which neighborhoods may impact cognitive outcomes. These results have implications for measuring neighborhood characteristics, design and maintenance of living spaces, and interventions to increase walking among older adults. We offer suggestions for future research measuring neighborhood characteristics and cognitive function. PMID:26504889

  7. Numerical simulation of a twin screw expander for performance prediction

    NASA Astrophysics Data System (ADS)

    Papes, Iva; Degroote, Joris; Vierendeels, Jan

    2015-08-01

    With the increasing use of twin screw expanders in waste heat recovery applications, the performance prediction of these machines plays an important role. This paper presents a mathematical model for calculating the performance of a twin screw expander. From the mass and energy conservation laws, differential equations are derived which are then solved together with the appropriate Equation of State in the instantaneous control volumes. Different flow processes that occur inside the screw expander such as filling (accompanied by a substantial pressure loss) and leakage flows through the clearances are accounted for in the model. The mathematical model employs all geometrical parameters such as chamber volume, suction and leakage areas. With R245fa as working fluid, the Aungier Redlich-Kwong Equation of State has been used in order to include real gas effects. To calculate the mass flow rates through the leakage paths formed inside the screw expander, flow coefficients are considered as constant and they are derived from 3D Computational Fluid Dynamic calculations at given working conditions and applied to all other working conditions. The outcome of the mathematical model is the P-V indicator diagram which is compared to CFD results of the same twin screw expander. Since CFD calculations require significant computational time, developed mathematical model can be used for the faster performance prediction.

  8. Cortical structure predicts success in performing musical transformation judgments.

    PubMed

    Foster, Nicholas E V; Zatorre, Robert J

    2010-10-15

    Recognizing melodies by their interval structure, or "relative pitch," is a fundamental aspect of musical perception. By using relative pitch, we are able to recognize tunes regardless of the key in which they are played. We sought to determine the cortical areas important for relative pitch processing using two morphometric techniques. Cortical differences have been reported in musicians within right auditory cortex (AC), a region considered important for pitch-based processing, and we have previously reported a functional correlation between relative pitch processing in the anterior intraparietal sulcus (IPS). We addressed the hypothesis that regional variation of cortical structure within AC and IPS is related to relative pitch ability using two anatomical techniques, cortical thickness (CT) analysis and voxel-based morphometry (VBM) of magnetic resonance imaging data. Persons with variable amounts of formal musical training were tested on a melody transposition task, as well as two musical control tasks and a speech control task. We found that gray matter concentration and cortical thickness in right Heschl's sulcus and bilateral IPS both predicted relative pitch task performance and correlated to a lesser extent with performance on the two musical control tasks. After factoring out variance explained by musical training, only relative pitch performance was predicted by cortical structure in these regions. These results directly demonstrate the functional relevance of previously reported anatomical differences in the auditory cortex of musicians. The findings in the IPS provide further support for the existence of a multimodal network for systematic transformation of stimulus information in this region. PMID:20600982

  9. WRF Performance Skills in Predicting Rainfall Over the Philippines

    NASA Astrophysics Data System (ADS)

    Perez, G. J. P.; Combinido, J. S.

    2014-12-01

    The Weather Research and Forecasting (WRF) model has been used for predicting rainfall over the Philippines. The period of October 2013 to May 2014 is chosen for the evaluation because of the unprecedented number of new ground instruments (300 to 500 automated rain gauges). It also gives us a good statistical representation of wet and dry seasons in the country. The WRF model configuration makes use of NCEP FNL for the initial boundary condition. Hindcasts are produced at 12-km resolution with 12 hours up to 144 hours lead-time. To assess the predictability of rainfall, we look at the dichotomous case, wherein we evaluate if the model is able to predict correctly the number of rainfall events. The left column in Figure 1 shows the monthly Percent Correct and Critical Success Index (CSI) for different lead-time. Percent Correct represents how well the model performs, 1 being the highest score, with equal bearing on correct positives and correct negatives. On the other hand, CSI is a balanced score that accounts for false alarm and missed events - it has a range of 0 to 1, where 1 means perfect forecast. Results show that during the wet season (October, November and December), PC is approximately 0.7 while in dry season (January, February and March), PC reaches values of around 0.9, which suggests improvement in the performance from wet to dry season. The increase in performance is attributed to the increase in number of correct negatives during the dry season. The CSI score, which excludes the correct negatives, shows that the ability of WRF to predict rainfall events drastically decline in December or during the transition from wet to dry season. This is due to the inability of WRF to pinpoint exact locations of small convective rainfall events. The predictability of actual rainfall values is indicated by the Mean Absolute Errors (MAE) and Root Mean Square Errors (RMSE) in Figure 1. The MAE for 3-hour accumulated rainfall is smallest during the dry season.

  10. Application of Phase-field Method in Predicting Gas Bubble Microstructure Evolution in Nuclear Fuels

    SciTech Connect

    Hu, Shenyang Y.; Li, Yulan; Sun, Xin; Gao, Fei; Devanathan, Ramaswami; Henager, Charles H.; Khaleel, Mohammad A.

    2010-04-30

    Fission product accumulation and gas bubble microstructure evolution in nuclear fuels strongly affect thermo-mechanical properties such as thermal conductivity, gas release, volumetric swelling and cracking, and hence the fuel performance. In this paper, a general phase-field model is developed to predict gas bubble formation and evolution. Important materials processes and thermodynamic properties including the generation of gas atoms and vacancies, sinks for vacancies and gas atoms, the elastic interaction among defects, gas re-solution, and inhomogeneity of elasticity and diffusivity are accounted for in the model. The simulations demonstrate the potential application of the phase-field method in investigating 1) heterogeneous nucleation of gas bubbles at defects; 2) effect of elastic interaction, inhomogeneity of material properties, and gas re-solution on gas bubble microstructures; and 3) effective properties from the output of phase-field simulations such as distribution of defects, gas bubbles, and stress fields.

  11. Thermal Model Predictions of Advanced Stirling Radioisotope Generator Performance

    NASA Technical Reports Server (NTRS)

    Wang, Xiao-Yen J.; Fabanich, William Anthony; Schmitz, Paul C.

    2014-01-01

    This paper presents recent thermal model results of the Advanced Stirling Radioisotope Generator (ASRG). The three-dimensional (3D) ASRG thermal power model was built using the Thermal Desktop(trademark) thermal analyzer. The model was correlated with ASRG engineering unit test data and ASRG flight unit predictions from Lockheed Martin's (LM's) I-deas(trademark) TMG thermal model. The auxiliary cooling system (ACS) of the ASRG is also included in the ASRG thermal model. The ACS is designed to remove waste heat from the ASRG so that it can be used to heat spacecraft components. The performance of the ACS is reported under nominal conditions and during a Venus flyby scenario. The results for the nominal case are validated with data from Lockheed Martin. Transient thermal analysis results of ASRG for a Venus flyby with a representative trajectory are also presented. In addition, model results of an ASRG mounted on a Cassini-like spacecraft with a sunshade are presented to show a way to mitigate the high temperatures of a Venus flyby. It was predicted that the sunshade can lower the temperature of the ASRG alternator by 20 C for the representative Venus flyby trajectory. The 3D model also was modified to predict generator performance after a single Advanced Stirling Convertor failure. The geometry of the Microtherm HT insulation block on the outboard side was modified to match deformation and shrinkage observed during testing of a prototypic ASRG test fixture by LM. Test conditions and test data were used to correlate the model by adjusting the thermal conductivity of the deformed insulation to match the post-heat-dump steady state temperatures. Results for these conditions showed that the performance of the still-functioning inboard ACS was unaffected.

  12. A hybrid numerical technique for predicting the aerodynamic and acoustic fields of advanced turboprops

    NASA Technical Reports Server (NTRS)

    Homicz, G. F.; Moselle, J. R.

    1985-01-01

    A hybrid numerical procedure is presented for the prediction of the aerodynamic and acoustic performance of advanced turboprops. A hybrid scheme is proposed which in principle leads to a consistent simultaneous prediction of both fields. In the inner flow a finite difference method, the Approximate-Factorization Alternating-Direction-Implicit (ADI) scheme, is used to solve the nonlinear Euler equations. In the outer flow the linearized acoustic equations are solved via a Boundary-Integral Equation (BIE) method. The two solutions are iteratively matched across a fictitious interface in the flow so as to maintain continuity. At convergence the resulting aerodynamic load prediction will automatically satisfy the appropriate free-field boundary conditions at the edge of the finite difference grid, while the acoustic predictions will reflect the back-reaction of the radiated field on the magnitude of the loading source terms, as well as refractive effects in the inner flow. The equations and logic needed to match the two solutions are developed and the computer program implementing the procedure is described. Unfortunately, no converged solutions were obtained, due to unexpectedly large running times. The reasons for this are discussed and several means to alleviate the situation are suggested.

  13. Performance prediction for windmills with linkage-guided blades

    SciTech Connect

    Nahas, M.N.; Akyurt, M. )

    1992-01-01

    Three windmills with linkage-guided blades that were previously described by the authors are future studied to predict their performance. The present paper concentrates on the guiding mechanisms of the active power producing surfaces (or blades) and on the output torque. Also investigated here is the effect of the orientation of these blades with respect to their guiding links. The fluctuation in the output torque of one-blade windmills has led to the investigation of the output torque that can be obtained from three-bladed machines. These latter windmills are found to reduce the fluctuation in the output torque considerably. Areas for further improvement are discussed.

  14. Predicting the optimized thermoelectric performance of MgAgSb

    NASA Astrophysics Data System (ADS)

    Sheng, C. Y.; Liu, H. J.; Fan, D. D.; Cheng, L.; Zhang, J.; Wei, J.; Liang, J. H.; Jiang, P. H.; Shi, J.

    2016-05-01

    Using first-principles method and Boltzmann theory, we provide an accurate prediction of the electronic band structure and thermoelectric transport properties of α-MgAgSb. Our calculations demonstrate that only when an appropriate exchange-correlation functional is chosen can we correctly reproduce the semiconducting nature of this compound. By fine tuning the carrier concentration, the thermoelectric performance of α-MgAgSb can be significantly optimized, which exhibits a strong temperature dependence and gives a maximum ZT value of 1.7 at 550 K. We also provide a simple map by which one can efficiently find the best doping atoms and optimal doping content.

  15. Accurate Structure Prediction and Conformational Analysis of Cyclic Peptides with Residue-Specific Force Fields.

    PubMed

    Geng, Hao; Jiang, Fan; Wu, Yun-Dong

    2016-05-19

    Cyclic peptides (CPs) are promising candidates for drugs, chemical biology tools, and self-assembling nanomaterials. However, the development of reliable and accurate computational methods for their structure prediction has been challenging. Here, 20 all-trans CPs of 5-12 residues selected from Cambridge Structure Database have been simulated using replica-exchange molecular dynamics with four different force fields. Our recently developed residue-specific force fields RSFF1 and RSFF2 can correctly identify the crystal-like conformations of more than half CPs as the most populated conformation. The RSFF2 performs the best, which consistently predicts the crystal structures of 17 out of 20 CPs with rmsd < 1.1 Å. We also compared the backbone (ϕ, ψ) sampling of residues in CPs with those in short linear peptides and in globular proteins. In general, unlike linear peptides, CPs have local conformational free energies and entropies quite similar to globular proteins. PMID:27128113

  16. Analytical Prediction and Optimization of Far-Field Pyroshock Test Procedures

    NASA Astrophysics Data System (ADS)

    Lacher, Alexander; Jungel, Nikolas; von Wagner, Utz; Bager, Annette

    2012-07-01

    The simulation of far-field pyroshocks is mainly performed by the use of mechanical or mechatronic devices such as hammer pendulums, shakers and piezoactors. Latter show limitations concerning frequency and acceleration ranges which does not hold for hammer pendulums or bolt guns. Their controllability, however, is rather unsatisfactory and there still exists a general lack of computational prediction tools for usually time consuming and costly far-field pyroshock tests. Mechanical minimal models of existing hammer test devices are presented and investigated by the use of the finite element and analytical methods. The tedious mechanical impact problem is reduced by introducing a nonlinear compressive spring connecting striking partners. Computational test results are verified by experiments and optimized by an evolution strategy allowing for determination of optimum test parameters. The algorithms developed are the basis for fast and efficient predictions of pyroshock tests.

  17. Analytic prediction of sidelobe statistics for matched-field processing

    NASA Astrophysics Data System (ADS)

    Tracey, Brian; Lee, Nigel; Zurk, Lisa

    2002-05-01

    Underwater source localization using matched-field processing (MFP) is complicated by the relatively high sidelobe levels characteristic of MFP ambiguity surfaces. An understanding of sidelobe statistics is expected to aid in designing robust detection and localization algorithms. MFP sidelobe levels are influenced by the underwater channel, array design, and mismatch between assumed and actual environmental parameters. In earlier work [J. Acoust. Soc. Am. 108, 2645 (2000)], a statistical approach was used to derive analytic expressions for the probability distribution function of the Bartlett ambiguity surface. The distribution was shown to depend on the orthogonality of the mode shapes as sampled by the array. Extensions to a wider class of array geometries and to broadband processing will be shown. Numerical results demonstrating the accuracy of the analytic results and exploring their range of validity will be presented. Finally, analytic predictions will be compared to data from the Santa Barbara Channel experiment. [Work sponsored by DARPA under Air Force Contract F19628-00-C0002. Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the Department of Defense.

  18. Predicting Native English-Like Performance by Native Japanese Speakers

    PubMed Central

    Ingvalson, Erin M.; McClelland, James L.; Holt, Lori L.

    2011-01-01

    This study tested the predictions of the Speech Learning Model (SLM, Flege, 1988) on the case of native Japanese (NJ) speakers’ perception and production of English /ɹ / and /l/. NJ speakers’ degree of foreign accent, intelligibility of /ɹ –l/ productions, and ability to perceive natural speech /ɹ –l/ were assessed as a function of length of residency in North America, age of arrival in North America, years of student status in an English environment, and percentage of Japanese usage. Additionally, the extent to which NJ speakers’ utilized the F3 onset cue when differentiating /ɹ –l/ in perception and production was assessed, this cue having previously been shown to be the most reliable indicator of category membership. As predicted, longer residencies predicted more native English-like accents, more intelligible productions, and more accurate natural speech identifications; however, no changes were observed in F3 reliance, indicating that though performance improves it does so through reliance on other cues. PMID:22021941

  19. Planetary Suit Hip Bearing Model for Predicting Design vs. Performance

    NASA Technical Reports Server (NTRS)

    Cowley, Matthew S.; Margerum, Sarah; Harvil, Lauren; Rajulu, Sudhakar

    2011-01-01

    , the suited performance trends were comparable between the model and the suited subjects. With the three off-nominal bearing configurations compared to the nominal bearing configurations, human subjects showed decreases in hip flexion of 64%, 6%, and 13% and in hip abduction of 59%, 2%, and 20%. Likewise the solid model showed decreases in hip flexion of 58%, 1%, and 25% and in hip abduction of 56%, 0%, and 30%, under the same condition changes from the nominal configuration. Differences seen between the model predictions and the human subject performance data could be attributed to the model lacking dynamic elements and performing kinematic analysis only, the level of fit of the subjects with the suit, the levels of the subject s suit experience.

  20. Performance and Prediction: Bayesian Modelling of Fallible Choice in Chess

    NASA Astrophysics Data System (ADS)

    Haworth, Guy; Regan, Ken; di Fatta, Giuseppe

    Evaluating agents in decision-making applications requires assessing their skill and predicting their behaviour. Both are well developed in Poker-like situations, but less so in more complex game and model domains. This paper addresses both tasks by using Bayesian inference in a benchmark space of reference agents. The concepts are explained and demonstrated using the game of chess but the model applies generically to any domain with quantifiable options and fallible choice. Demonstration applications address questions frequently asked by the chess community regarding the stability of the rating scale, the comparison of players of different eras and/or leagues, and controversial incidents possibly involving fraud. The last include alleged under-performance, fabrication of tournament results, and clandestine use of computer advice during competition. Beyond the model world of games, the aim is to improve fallible human performance in complex, high-value tasks.

  1. Numerical Prediction of SERN Performance using WIND code

    NASA Technical Reports Server (NTRS)

    Engblom, W. A.

    2003-01-01

    Computational results are presented for the performance and flow behavior of single-expansion ramp nozzles (SERNs) during overexpanded operation and transonic flight. Three-dimensional Reynolds-Averaged Navier Stokes (RANS) results are obtained for two vehicle configurations, including the NASP Model 5B and ISTAR RBCC (a variant of X-43B) using the WIND code. Numerical predictions for nozzle integrated forces and pitch moments are directly compared to experimental data for the NASP Model 5B, and adequate-to-excellent agreement is found. The sensitivity of SERN performance and separation phenomena to freestream static pressure and Mach number is demonstrated via a matrix of cases for both vehicles. 3-D separation regions are shown to be induced by either lateral (e.g., sidewall) shocks or vertical (e.g., cowl trailing edge) shocks. Finally, the implications of this work to future preliminary design efforts involving SERNs are discussed.

  2. Prediction Versus Reality: The Use of Mathematical Models to Predict Elite Performance in Swimming and Athletics at the Olympic Games

    PubMed Central

    Heazlewood, Timothy

    2006-01-01

    A number of studies have attempted to predict future Olympic performances in athletics and swimming based on trends displayed in previous Olympic Games. Some have utilised linear models to plot and predict change, whereas others have utilised multiple curve estimation methods based on inverse, sigmoidal, quadratic, cubic, compound, logistic, growth and exponential functions. The non linear models displayed closer fits to the actual data and were used to predict performance changes 10’s, 100’s and 1000’s of years into the future. Some models predicted that in some events male and female times and distances would crossover and females would eventually display superior performance to males. Predictions using mathematical models based on pre-1996 athletics and pre-1998 swimming performances were evaluated based on how closely they predicted sprints and jumps, and freestyle swimming performances for both male and females at the 2000 and 2004 Olympic Games. The analyses revealed predictions were closer for the shorter swimming events where men’s 50m and women’s 50m and 100m actual times were almost identical to predicted times. For both men and women, as the swim distances increased the accuracy of the predictive model decreased, where predicted times were 4.5-7% faster than actual times achieved. The real trends in some events currently displaying performance declines were not foreseen by the mathematical models, which predicted consistent improvements across all athletic and swimming events selected for in this study. Key Points Prediction of future Olympic performance based on previous performance trends. Application of non-linear mathematical equations resulting in better fitting models. Application of mathematical predictive models to the Olympic sports of athletics and swimming. Accuracy of mathematical models in predicting sprint events in running and swimming. A research approach to predict future Olympic performance and set future performance standards

  3. Alkaline flood prediction studies, Ranger VII pilot, Wilmington Field, California

    SciTech Connect

    Mayer, E.H.; Breit, V.S.

    1986-01-01

    This paper discusses the design of a simulator to model alkaline displacement mechanisms, along with the current understanding of in-situ caustic consumption. Assimilation of laboratory coreflood and rock consumption data, and their use in one- and two-dimensional (1D and 2D) limited area simulations and in three-dimensional (3D) models of the entire pilot project are given. This paper also reports simulation studies of alkaline flood behavior in a small 2D area of a field for various concentrations, slug sizes, long-term consumption functions, and two relative-permeability adjustment mechanisms. The scale-up of 2D simulation results and their use in a 271-acre (1096.7-ha), seven-layered, 3D model of the pilot are also discussed and 3D simulator results are compared with initial field alkaline flood performance. Finally, recommended additional applications of the simulator methods developed in this pilot and in other alkaline floods are discussed.

  4. A phenomenological performance model for applied-field MPD thrusters

    NASA Astrophysics Data System (ADS)

    Albertoni, R.; Paganucci, F.; Andrenucci, M.

    2015-02-01

    A theoretical model for the performance prediction of applied-field magnetoplasmadynamic thrusters (MPDTs) is presented. MPD thrusters have been long regarded as leading candidates for near-term, thrust-demanding missions due to their substantial thrust density and specific impulse even at moderate power levels (50-200 kW). However, the complicated physics behind the acceleration mechanism as well as the challenging on-ground testing have delayed their development and optimization leading to a slow but constant decline of interest in such a technology. Despite several theoretical efforts in the last few decades, no complete and definitive understanding of the scaling relations governing their performance is yet available. In this work, a simple phenomenological model for both the thrust and the terminal voltage is presented and discussed. The validity of the model is then assessed through a systematic comparison with the experimental data available in the literature. It was found that the suggested model can actually capture most of the characteristic features of this class of thrusters within a 20% error for a wide range of operational conditions.

  5. Increased Genomic Prediction Accuracy in Wheat Breeding Through Spatial Adjustment of Field Trial Data

    PubMed Central

    Lado, Bettina; Matus, Ivan; Rodríguez, Alejandra; Inostroza, Luis; Poland, Jesse; Belzile, François; del Pozo, Alejandro; Quincke, Martín; Castro, Marina; von Zitzewitz, Jarislav

    2013-01-01

    In crop breeding, the interest of predicting the performance of candidate cultivars in the field has increased due to recent advances in molecular breeding technologies. However, the complexity of the wheat genome presents some challenges for applying new technologies in molecular marker identification with next-generation sequencing. We applied genotyping-by-sequencing, a recently developed method to identify single-nucleotide polymorphisms, in the genomes of 384 wheat (Triticum aestivum) genotypes that were field tested under three different water regimes in Mediterranean climatic conditions: rain-fed only, mild water stress, and fully irrigated. We identified 102,324 single-nucleotide polymorphisms in these genotypes, and the phenotypic data were used to train and test genomic selection models intended to predict yield, thousand-kernel weight, number of kernels per spike, and heading date. Phenotypic data showed marked spatial variation. Therefore, different models were tested to correct the trends observed in the field. A mixed-model using moving-means as a covariate was found to best fit the data. When we applied the genomic selection models, the accuracy of predicted traits increased with spatial adjustment. Multiple genomic selection models were tested, and a Gaussian kernel model was determined to give the highest accuracy. The best predictions between environments were obtained when data from different years were used to train the model. Our results confirm that genotyping-by-sequencing is an effective tool to obtain genome-wide information for crops with complex genomes, that these data are efficient for predicting traits, and that correction of spatial variation is a crucial ingredient to increase prediction accuracy in genomic selection models. PMID:24082033

  6. Prediction of the Aero-Acoustic Performance of Open Rotors

    NASA Technical Reports Server (NTRS)

    VanZante, Dale; Envia, Edmane

    2014-01-01

    The rising cost of jet fuel has renewed interest in contrarotating open rotor propulsion systems. Contemporary design methods offer the potential to maintain the inherently high aerodynamic efficiency of open rotors while greatly reducing their noise output, something that was not feasible in the 1980's designs. The primary source mechanisms of open rotor noise generation are thought to be the front rotor wake and tip vortex interacting with the aft rotor. In this paper, advanced measurement techniques and high-fidelity prediction tools are used to gain insight into the relative importance of the contributions to the open rotor noise signature of the front rotor wake and rotor tip vortex. The measurements include three-dimensional particle image velocimetry of the intra-rotor flowfield and the acoustic field of a model-scale open rotor. The predictions provide the unsteady flowfield and the associated acoustic field. The results suggest that while the front rotor tip vortex can have a significant influence on the blade passing tone noise produced by the aft rotor, the front rotor wake plays the decisive role in the generation of the interaction noise produced as a result of the unsteady aerodynamic interaction of the two rotors. At operating conditions typical of takeoff and landing operations, the interaction noise level is easily on par with that generated by the individual rotors, and in some cases is even higher. This suggests that a comprehensive approach to reducing open rotor noise should include techniques for mitigating the wake of the front rotor as well as eliminating the interaction of the front rotor tip vortex with the aft rotor blade tip.

  7. Predicting performance in competitive apnea diving. Part III: deep diving.

    PubMed

    Schagatay, Erika

    2011-12-01

    The first of these reviews described the physiological factors defining the limits of static apnea, while the second examined performance in apneic distance swimming. This paper reviews the factors determining performance in depth disciplines, where hydrostatic pressure is added to the stressors associated with apnea duration and physical work. Apneic duration is essential for performance in all disciplines, and is prolonged by any means that increases gas storage or tolerance to asphyxia or reduces metabolic rate. For underwater distance swimming, the main challenge is to restrict metabolism despite the work of swimming, and to redirect blood flow to allow the most vital functions. Here, work economy, local tissue energy and oxygen stores, anaerobic capacity of the muscles, and possibly technical improvements will be essential for further development. In the depth disciplines, direct pressure effects causing barotrauma, the narcotic effects of gases, decompression sickness (DCS) and possibly air embolism during ascent need to be taken into account, as does the risk of hypoxia when the dive cannot be rapidly interrupted before the surface is reached again. While in most deep divers apneic duration is not the main limitation thus far, greater depths may call for exceptionally long apneas and slower ascents to avoid DCS. Narcotic effects may also affect the ultimate depth limit, which the divers currently performing 'constant weight with fins' dives predict to be around 156 metres' sea water. To reach these depths, serious physiological challenges have to be met, technical developments needed and safety procedures developed concomitantly. PMID:22183699

  8. Predicting the Impacts of Intravehicular Displays on Driving Performance with Human Performance Modeling

    NASA Technical Reports Server (NTRS)

    Mitchell, Diane Kuhl; Wojciechowski, Josephine; Samms, Charneta

    2012-01-01

    A challenge facing the U.S. National Highway Traffic Safety Administration (NHTSA), as well as international safety experts, is the need to educate car drivers about the dangers associated with performing distraction tasks while driving. Researchers working for the U.S. Army Research Laboratory have developed a technique for predicting the increase in mental workload that results when distraction tasks are combined with driving. They implement this technique using human performance modeling. They have predicted workload associated with driving combined with cell phone use. In addition, they have predicted the workload associated with driving military vehicles combined with threat detection. Their technique can be used by safety personnel internationally to demonstrate the dangers of combining distracter tasks with driving and to mitigate the safety risks.

  9. Burst muscle performance predicts the speed, acceleration, and turning performance of Anna's hummingbirds.

    PubMed

    Segre, Paolo S; Dakin, Roslyn; Zordan, Victor B; Dickinson, Michael H; Straw, Andrew D; Altshuler, Douglas L

    2015-01-01

    Despite recent advances in the study of animal flight, the biomechanical determinants of maneuverability are poorly understood. It is thought that maneuverability may be influenced by intrinsic body mass and wing morphology, and by physiological muscle capacity, but this hypothesis has not yet been evaluated because it requires tracking a large number of free flight maneuvers from known individuals. We used an automated tracking system to record flight sequences from 20 Anna's hummingbirds flying solo and in competition in a large chamber. We found that burst muscle capacity predicted most performance metrics. Hummingbirds with higher burst capacity flew with faster velocities, accelerations, and rotations, and they used more demanding complex turns. In contrast, body mass did not predict variation in maneuvering performance, and wing morphology predicted only the use of arcing turns and high centripetal accelerations. Collectively, our results indicate that burst muscle capacity is a key predictor of maneuverability. PMID:26583753

  10. Predictive hydrogeochemical modelling of bauxite residue sand in field conditions.

    PubMed

    Wissmeier, Laurin; Barry, David A; Phillips, Ian R

    2011-07-15

    The suitability of residue sand (the coarse fraction remaining from Bayer's process of bauxite refining) for constructing the surface cover of closed bauxite residue storage areas was investigated. Specifically, its properties as a medium for plant growth are of interest to ensure residue sand can support a sustainable ecosystem following site closure. The geochemical evolution of the residue sand under field conditions, its plant nutrient status and soil moisture retention were studied by integrated modelling of geochemical and hydrological processes. For the parameterization of mineral reactions, amounts and reaction kinetics of the mineral phases natron, calcite, tricalcium aluminate, sodalite, muscovite and analcime were derived from measured acid neutralization curves. The effective exchange capacity for ion adsorption was measured using three independent exchange methods. The geochemical model, which accounts for mineral reactions, cation exchange and activity corrected solution speciation, was formulated in the geochemical modelling framework PHREEQC, and partially validated in a saturated-flow column experiment. For the integration of variably saturated flow with multi-component solute transport in heterogeneous 2D domains, a coupling of PHREEQC with the multi-purpose finite-element solver COMSOL was established. The integrated hydrogeochemical model was applied to predict water availability and quality in a vertical flow lysimeter and a cover design for a storage facility using measured time series of rainfall and evaporation from southwest Western Australia. In both scenarios the sand was fertigated and gypsum-amended. Results show poor long-term retention of fertilizer ions and buffering of the pH around 10 for more than 5 y of leaching. It was concluded that fertigation, gypsum amendment and rainfall leaching alone were insufficient to render the geochemical conditions of residue sand suitable for optimal plant growth within the given timeframe. The

  11. Preliminary analytical results using surface current integration for predicting effects of surface pillows on RF performance

    NASA Technical Reports Server (NTRS)

    Farrell, C. E.; Strange, D. A.

    1982-01-01

    An overview of the fast integral RF evaluation (FIRE) program is presented. This program uses surface current integration to evaluate RF performance of antenna systems. It requires modeling of surfaces in X, Y, Z coordinates along equally spaced X and Y grids with Z in the focal directon. The far field contribution of each surface point includes the effects of the Z-component of surface current which is not included in the aperture integration technique. Because of this, surface current integration is the most effective and inclusive technique for predicting RF performance on non-ideal reflectors. Results obtained from use of the FIRE program and an aperture integration program to predict RF performance of a LSS antenna concept are presented.

  12. Performance Prediction of the NCAT Test Track Pavements Using Mechanistic Models

    NASA Astrophysics Data System (ADS)

    LaCroix, Andrew Thomas

    In the pavement industry in the United States of America, there is an increasing desire to improve the pavement construction quality and life for new and rehabilitated pavements. In order to improve the quality of the pavements, the Federal Highway Administration (FHWA) has pursued a performance-related specification (PRS) for over 20 years. The goal of PRS is to provide material and construction (M/C) properties that correlate well with pavement performance. In order to improve upon the PRS projects developed in WesTrack (NCHRP 9-20) and the MEPDG-based PRS (NCHRP 9-22), a set of PRS tests and models are proposed to provide a critical link between pavement performance and M/C properties. The PRS testing is done using the asphalt mixture performance tester (AMPT). The proposed PRS focuses on rutting and fatigue cracking of asphalt mixtures. The mixtures are characterized for their stiffness, fatigue behavior, and rutting resistance using a dynamic modulus (|E*|) test, a fatigue test, and a triaxial stress sweep (TSS) test, respectively. Information from the fatigue test characterizes the simplified viscoelastic continuum damage (S-VECD) model. Once the stiffness is reduced to a certain level, the material develops macro-cracks and fails. The TSS test is used to characterize a viscoplastic (VP) model. The VP model allows the prediction of the rut depth beneath the center of the wheel. The VECD and VP models are used within a layered viscoelastic (LVE) pavement model to predict fatigue and rutting performance of pavements. The PRS is evaluated by comparing the predictions to the field performance at the NCAT pavement test track in Opelika, Alabama. The test track sections evaluated are part of the 2009 test cycle group experiment, which focused on WMA, high RAP (50%), and a combination of both. The fatigue evaluation shows that all sections would last at least 18 years at the same traffic rate. The sections do not show any cracking, suggesting the sections are well

  13. Prediction of performance on the RCMP physical ability requirement evaluation.

    PubMed

    Stanish, H I; Wood, T M; Campagna, P

    1999-08-01

    The Royal Canadian Mounted Police use the Physical Ability Requirement Evaluation (PARE) for screening applicants. The purposes of this investigation were to identify those field tests of physical fitness that were associated with PARE performance and determine which most accurately classified successful and unsuccessful PARE performers. The participants were 27 female and 21 male volunteers. Testing included measures of aerobic power, anaerobic power, agility, muscular strength, muscular endurance, and body composition. Multiple regression analysis revealed a three-variable model for males (70-lb bench press, standing long jump, and agility) explaining 79% of the variability in PARE time, whereas a one-variable model (agility) explained 43% of the variability for females. Analysis of the classification accuracy of the males' data was prohibited because 91% of the males passed the PARE. Classification accuracy of the females' data, using logistic regression, produced a two-variable model (agility, 1.5-mile endurance run) with 93% overall classification accuracy. PMID:10457510

  14. Design and Performance Analysis of Incremental Networked Predictive Control Systems.

    PubMed

    Pang, Zhong-Hua; Liu, Guo-Ping; Zhou, Donghua

    2016-06-01

    This paper is concerned with the design and performance analysis of networked control systems with network-induced delay, packet disorder, and packet dropout. Based on the incremental form of the plant input-output model and an incremental error feedback control strategy, an incremental networked predictive control (INPC) scheme is proposed to actively compensate for the round-trip time delay resulting from the above communication constraints. The output tracking performance and closed-loop stability of the resulting INPC system are considered for two cases: 1) plant-model match case and 2) plant-model mismatch case. For the former case, the INPC system can achieve the same output tracking performance and closed-loop stability as those of the corresponding local control system. For the latter case, a sufficient condition for the stability of the closed-loop INPC system is derived using the switched system theory. Furthermore, for both cases, the INPC system can achieve a zero steady-state output tracking error for step commands. Finally, both numerical simulations and practical experiments on an Internet-based servo motor system illustrate the effectiveness of the proposed method. PMID:26186798

  15. Predicting the performance of a spatial gamut mapping algorithm

    NASA Astrophysics Data System (ADS)

    Bakke, Arne M.; Farup, Ivar; Hardeberg, Jon Y.

    2009-01-01

    Gamut mapping algorithms are currently being developed to take advantage of the spatial information in an image to improve the utilization of the destination gamut. These algorithms try to preserve the spatial information between neighboring pixels in the image, such as edges and gradients, without sacrificing global contrast. Experiments have shown that such algorithms can result in significantly improved reproduction of some images compared with non-spatial methods. However, due to the spatial processing of images, they introduce unwanted artifacts when used on certain types of images. In this paper we perform basic image analysis to predict whether a spatial algorithm is likely to perform better or worse than a good, non-spatial algorithm. Our approach starts by detecting the relative amount of areas in the image that are made up of uniformly colored pixels, as well as the amount of areas that contain details in out-of-gamut areas. A weighted difference is computed from these numbers, and we show that the result has a high correlation with the observed performance of the spatial algorithm in a previously conducted psychophysical experiment.

  16. Retrostructural model to predict biomass formulations for barrier performance.

    PubMed

    Zhu Ryberg, Y Z; Edlund, U; Albertsson, A-C

    2012-08-13

    Barrier performance and retrostructural modeling of the macromolecular components demonstrate new design principles for film formulations based on renewable wood hydrolysates. Hardwood hydrolysates, which contain a fair share of lignin coexisting with poly- and oligosaccharides, offer excellent oxygen-barrier performance. A Hansen solubility parameter (HSP) model has been developed to convert the complex hydrolysate structural compositions into relevant matrix oxygen-permeability data allowing a systematic prediction of how the biomass should be formulated to generate an efficient barrier. HSP modeling suggests that the molecular packing ability plays a key role in the barrier performance. The actual size and distribution of free volume holes in the matrices were quantified in the subnanometer scale with Positron annihilation lifetime spectroscopy (PALS) verifying the affinity-driven assembly of macromolecular segments in a densely packed morphology and regulating the diffusion of small permeants through the matrix. The model is general and can be adapted to determine the macromolecular affinities of any hydrolysate biomass based on chemical composition. PMID:22804452

  17. Geoscience Laser Ranging System design and performance predictions

    NASA Technical Reports Server (NTRS)

    Anderson, Kent L.

    1991-01-01

    The Geoscience Laser System (GLRS) will be a high-precision distance-measuring instrument planned for deployment on the EOS-B platform. Its primary objectives are to perform ranging measurements to ground targets to monitor crustal deformation and tectonic plate motions, and nadir-looking altimetry to determine ice sheet thicknesses, surface topography, and vertical profiles of clouds and aerosols. The system uses a mode-locked, 3-color Nd:YAG laser source, a Microchannel Plate-PMT for absolute time-of-flight (TOF) measurement (at 532 nm), a streak camera for TOF 2-color dispersion measurement (532 nm and 355 nm), and a Si avalanche photodiode for altimeter waveform detection (1064 nm). The performance goals are to make ranging measurements to ground targets with about 1 cm accuracy, and altimetry height measurements over ice with 10 cm accuracy. This paper presents an overview of the design concept developed during a phase B study. System engineering issues and trade studies are discussed, with particular attention to error budgets and performance predictions.

  18. Evaluation of predictive tools for cell culture clarification performance.

    PubMed

    Senczuk, Anna; Petty, Krista; Thomas, Anne; McNerney, Thomas; Moscariello, John; Yigzaw, Yinges

    2016-03-01

    Recent advances in the productivity of industrial mammalian cell culture processes have resulted in part in increased cell density. This increase and the associated increase in cellular debris are known to challenge harvest operations, however this understanding is limited and largely qualitative. Part of the issue arises from the heterogeneous size and composition of cellular debris, which makes harvest feed stream extremely difficult to characterize. Improved characterization methods would facilitate the development of clarification approaches that are consistent and scalable. This work describes how both particle size and cholesterol analysis can be used to characterize the feed stream. Particle size analysis by focused beam reflectance and dynamic light scattering are shown to be predictive of centrate filterability under certain harvest conditions. Because of the particle size range limitations of each detector, their applicability is limited to a particular stage or method of clarification. The measurement of cholesterol present in the cell culture supernatant or centrate was successfully used in providing relative amount of lysed cellular debris and enabled us to predict clarification performance of acid precipitated harvest regardless of particle size distribution profile. PMID:26332572

  19. Zero-G Thermodynamic Venting System (TVS) Performance Prediction Program

    NASA Technical Reports Server (NTRS)

    Nguyen, Han

    1994-01-01

    This report documents the Zero-g Thermodynamic Venting System (TVS) performance prediction computer program. The zero-g TVS is a device that destratifies and rejects environmentally induced zero-g thermal gradients in the LH2 storage transfer system. A recirculation pump and spray injection manifold recirculates liquid throughout the length of the tank thereby destratifying both the ullage gas and liquid bulk. Heat rejection is accomplished by the opening of the TVS control valve which allows a small flow rate to expand to a low pressure thereby producing a low temperature heat sink which is used to absorb heat from the recirculating liquid flow. The program was written in FORTRAN 77 language on the HP-9000 and IBM PC computers. It can be run on various platforms with a FORTRAN compiler.

  20. Predicting variations of perceptual performance across individuals from neural activity using pattern classifiers.

    PubMed

    Das, Koel; Giesbrecht, Barry; Eckstein, Miguel P

    2010-07-15

    Within the past decade computational approaches adopted from the field of machine learning have provided neuroscientists with powerful new tools for analyzing neural data. For instance, previous studies have applied pattern classification algorithms to electroencephalography data to predict the category of presented visual stimuli, human observer decision choices and task difficulty. Here, we quantitatively compare the ability of pattern classifiers and three ERP metrics (peak amplitude, mean amplitude, and onset latency of the face-selective N170) to predict variations across individuals' behavioral performance in a difficult perceptual task identifying images of faces and cars embedded in noise. We investigate three different pattern classifiers (Classwise Principal Component Analysis, CPCA; Linear Discriminant Analysis, LDA; and Support Vector Machine, SVM), five training methods differing in the selection of training data sets and three analyses procedures for the ERP measures. We show that all three pattern classifier algorithms surpass traditional ERP measurements in their ability to predict individual differences in performance. Although the differences across pattern classifiers were not large, the CPCA method with training data sets restricted to EEG activity for trials in which observers expressed high confidence about their decisions performed the highest at predicting perceptual performance of observers. We also show that the neural activity predicting the performance across individuals was distributed through time starting at 120ms, and unlike the face-selective ERP response, sustained for more than 400ms after stimulus presentation, indicating that both early and late components contain information correlated with observers' behavioral performance. Together, our results further demonstrate the potential of pattern classifiers compared to more traditional ERP techniques as an analysis tool for modeling spatiotemporal dynamics of the human brain and

  1. Performance of FFT methods in local gravity field modelling

    NASA Technical Reports Server (NTRS)

    Forsberg, Rene; Solheim, Dag

    1989-01-01

    Fast Fourier transform (FFT) methods provide a fast and efficient means of processing large amounts of gravity or geoid data in local gravity field modelling. The FFT methods, however, has a number of theoretical and practical limitations, especially the use of flat-earth approximation, and the requirements for gridded data. In spite of this the method often yields excellent results in practice when compared to other more rigorous (and computationally expensive) methods, such as least-squares collocation. The good performance of the FFT methods illustrate that the theoretical approximations are offset by the capability of taking into account more data in larger areas, especially important for geoid predictions. For best results good data gridding algorithms are essential. In practice truncated collocation approaches may be used. For large areas at high latitudes the gridding must be done using suitable map projections such as UTM, to avoid trivial errors caused by the meridian convergence. The FFT methods are compared to ground truth data in New Mexico (xi, eta from delta g), Scandinavia (N from delta g, the geoid fits to 15 cm over 2000 km), and areas of the Atlantic (delta g from satellite altimetry using Wiener filtering). In all cases the FFT methods yields results comparable or superior to other methods.

  2. Metamaterial magnetoinductive lens performance as a function of field strength.

    PubMed

    Algarín, José M; Freire, Manuel J; Breuer, Felix; Behr, Volker C

    2014-10-01

    Metamaterials are artificial composites that exhibit exotic electromagnetic properties, as the ability of metamaterial slabs to behave like lenses with sub-wavelength resolution for the electric or the magnetic field. In previous works, the authors investigated magnetic resonance imaging (MRI) applications of metamaterial slabs that behave like lenses for the radiofrequency magnetic field. In particular, the authors investigated the ability of MRI metamaterial lenses to increase the signal-to-noise ratio (SNR) of surface coils, and to localize the field of view (FOV) of the coils, which is of interest for parallel MRI (pMRI) applications. A metamaterial lens placed between a surface coil and the tissue enhances the sensitivity of the coil. Although the metamaterial lens introduces losses which add to the losses of the tissue, the enhancement of the sensitivity can compensate these additional losses and the SNR of the coil is increased. In a previous work, an optimization procedure was followed to find a metamaterial structure with minimum losses that will maximize the SNR. This structure was termed magnetoinductive (MI) lens by the authors. The properties of surface coils in the presence of MI lenses were investigated in previous works at the proton frequency of 1.5 T systems. The different frequency dependence of the losses in both the MI lenses and the tissue encouraged us to investigate the performance of MI lenses at different frequencies. Thus, in the present work, the SNR and the pMRI ability of MI lenses are investigated as a function of field strength. A numerical analysis is carried out with an algorithm developed by the authors to predict the SNR behavior of a surface coil loaded with a MI lens at the proton frequencies of 0.5 T, 1.5 T and 3 T systems. The results show that, at 0.5 T, there is a gain in the SNR for short distances, but the SNR is highly degraded at deeper distances. However, at 1.5 T and 3T, the MI lenses provide a gain in the SNR up to a

  3. Can formative quizzes predict or improve summative exam performance?*

    PubMed Central

    Zhang, Niu; Henderson, Charles N.R.

    2015-01-01

    Objective Despite wide use, the value of formative exams remains unclear. We evaluated the possible benefits of formative assessments in a physical examination course at our chiropractic college. Methods Three hypotheses were examined: (1) Receiving formative quizzes (FQs) will increase summative exam (SX) scores, (2) writing FQ questions will further increase SE scores, and (3) FQs can predict SX scores. Hypotheses were tested across three separate iterations of the class. Results The SX scores for the control group (Class 3) were significantly less than those of Classes 1 and 2, but writing quiz questions and taking FQs (Class 1) did not produce significantly higher SX scores than only taking FQs (Class 2). The FQ scores were significant predictors of SX scores, accounting for 52% of the SX score. Sex, age, academic degrees, and ethnicity were not significant copredictors. Conclusion Our results support the assertion that FQs can improve written SX performance, but students producing quiz questions didn't further increase SX scores. We concluded that nonthreatening FQs may be used to enhance student learning and suggest that they also may serve to identify students who, without additional remediation, will perform poorly on subsequent summative written exams. PMID:25517737

  4. Computational Predictions of the Performance Wright 'Bent End' Propellers

    NASA Technical Reports Server (NTRS)

    Wang, Xiang-Yu; Ash, Robert L.; Bobbitt, Percy J.; Prior, Edwin (Technical Monitor)

    2002-01-01

    Computational analysis of two 1911 Wright brothers 'Bent End' wooden propeller reproductions have been performed and compared with experimental test results from the Langley Full Scale Wind Tunnel. The purpose of the analysis was to check the consistency of the experimental results and to validate the reliability of the tests. This report is one part of the project on the propeller performance research of the Wright 'Bent End' propellers, intend to document the Wright brothers' pioneering propeller design contributions. Two computer codes were used in the computational predictions. The FLO-MG Navier-Stokes code is a CFD (Computational Fluid Dynamics) code based on the Navier-Stokes Equations. It is mainly used to compute the lift coefficient and the drag coefficient at specified angles of attack at different radii. Those calculated data are the intermediate results of the computation and a part of the necessary input for the Propeller Design Analysis Code (based on Adkins and Libeck method), which is a propeller design code used to compute the propeller thrust coefficient, the propeller power coefficient and the propeller propulsive efficiency.

  5. Performance predicting factors in prolonged exhausting exercise of varying intensity.

    PubMed

    Björklund, Glenn; Pettersson, Sofia; Schagatay, Erika

    2007-03-01

    Several endurance sports, e.g. road cycling, have a varying intensity profile during competition. At present, few laboratory tests take this intensity profile into consideration. Thus, the purpose of this study was to examine the prognostic value of heart rate (HR), lactate (La(-1)), potassium (K(+)), and respiratory exchange ratio (RER) performance at an exhausting cycling exercise with varying intensity. Eight national level cyclists performed two cycle tests each on a cycle ergometer: (1) a incremental test to establish VO(2max), maximum power (W (max)), and lactate threshold (VO(2LT)), and (2) a variable intensity protocol (VIP). Exercise intensity for the VIP was based upon the VO(2max) obtained during the incremental test. The VIP consisted of six high intense (HI) workloads at 90% of VO(2max) for 3 min each, interspersed by five middle intense (MI) workloads at 70% of VO(2max )for 6 min each. VO(2 )and HR were continuously measured throughout the tests. Venous blood samples were taken before, during, and after the test. Increases in HR, La(-), K(+), and RER were observed when workload changed from MI to HI workload (P < 0.05). Potassium and RER decreased after transition from HI to MI workloads (P < 0.05). There was a negative correlation between time to exhaustion and decrease in La(-) concentration during the first MI (r = -0.714; P = 0.047). Furthermore, time to exhaustion correlated with VO(2LT )calculated from the ramp test (r = 0.738; P = 0.037). Our results suggest that the magnitude of decrease of La(-1) between the first HI workload and the consecutive MI workload could predict performance during prolonged exercise with variable intensity. PMID:17186302

  6. Predicting Student Academic Performance in an Engineering Dynamics Course: A Comparison of Four Types of Predictive Mathematical Models

    ERIC Educational Resources Information Center

    Huang, Shaobo; Fang, Ning

    2013-01-01

    Predicting student academic performance has long been an important research topic in many academic disciplines. The present study is the first study that develops and compares four types of mathematical models to predict student academic performance in engineering dynamics--a high-enrollment, high-impact, and core course that many engineering…

  7. Use of Boundary Layer Transition Detection to Validate Full-Scale Flight Performance Predictions

    NASA Technical Reports Server (NTRS)

    Hamner, Marvine; Owens, L. R., Jr.; Wahls, R. A.; Yeh, David

    1999-01-01

    Full-scale flight performance predictions can be made using CFD or a combination of CFD and analytical skin-friction predictions. However, no matter what method is used to obtain full-scale flight performance predictions knowledge of the boundary layer state is critical. The implementation of CFD codes solving the Navier-Stokes equations to obtain these predictions is still a time consuming, expensive process. In addition, to ultimately obtain accurate performance predictions the transition location must be fixed in the CFD model. An example, using the M2.4-7A geometry, of the change in Navier-Stokes solution with changes in transition and in turbulence model will be shown. Oil flow visualization using the M2.4-7A 4.0% scale model in the 14'x22' wind tunnel shows that fixing transition at 10% x/c in the CFD model best captures the flow physics of the wing flow field. A less costly method of obtaining full-scale performance predictions is the use of non-linear Euler codes or linear CFD codes, such as panel methods, combined with analytical skin-friction predictions. Again, knowledge of the boundary layer state is critical to the accurate determination of full-scale flight performance. Boundary layer transition detection has been performed at 0.3 and 0.9 Mach numbers over an extensive Reynolds number range using the 2.2% scale Reference H model in the NTF. A temperature sensitive paint system was used to determine the boundary layer state for these conditions. Data was obtained for three configurations: the baseline, undeflected flaps configuration; the transonic cruise configuration; and, the high-lift configuration. It was determined that at low Reynolds number conditions, in the 8 to 10 million Reynolds number range, the baseline configuration has extensive regions of laminar flow, in fact significantly more than analytical skin-friction methods predict. This configuration is fully turbulent at about 30 million Reynolds number for both 0.3 and 0.9, Mach numbers

  8. Predicting Undergraduates' Persistence in Science, Technology, Engineering, and Math Fields

    ERIC Educational Resources Information Center

    Koch, Amanda Joy

    2013-01-01

    A national shortage of workers in Science, Technology, Engineering, and Math (STEM) occupations has led to efforts to identify why people leave these fields. Lower persistence rates in STEM for females than for males have also led to examinations of features that cause females to leave STEM fields. The current study examines individual- and…

  9. Calculation of the Lightning Potential Index and electric field in numerical weather prediction models

    NASA Astrophysics Data System (ADS)

    Dementyeva, S. O.; Ilin, N. V.; Mareev, E. A.

    2015-03-01

    Modern methods for predicting thunderstorms and lightnings with the use of high-resolution numerical models are considered. An analysis of the Lightning Potential Index (LPI) is performed for various microphysics parameterizations with the use of the Weather Research and Forecasting (WRF) model. The maximum index values are shown to depend significantly on the type of parameterization. This makes it impossible to specify a single threshold LPI for various parameterizations as a criterion for the occurrence of lightning flashes. The topographic LPI maps underestimate the sizes of regions of likely thunderstorm-hazard events. Calculating the electric field under the assumption that ice and graupel are the main charge carriers is considered a new algorithm of lightning prediction. The model shows that the potential difference (between the ground and cloud layer at a given altitude) sufficient to generate a discharge is retained in a larger region than is predicted by the LPI. The main features of the spatial distribution of the electric field and potential agree with observed data.

  10. Frontoparietal white matter integrity predicts haptic performance in chronic stroke

    PubMed Central

    Borstad, Alexandra L.; Choi, Seongjin; Schmalbrock, Petra; Nichols-Larsen, Deborah S.

    2015-01-01

    strongly correlated with the shared variance across tracts in the control, but not in the poststroke participants. A moderate to good relationship was found between ipsilesional T–M1 MD and affected hand HASTe score (r = − 0.62, p = 0.006) and less affected hand HASTe score (r = − 0.53, p = 0.022). Regression analysis revealed approximately 90% of the variance in affected hand HASTe score was predicted by the white matter integrity in the frontoparietal network (as indexed by MD) in poststroke participants while 87% of the variance in HASTe score was predicted in control participants. This study demonstrates the importance of frontoparietal white matter in mediating haptic performance and specifically identifies that T–M1 and precuneus interhemispheric tracts may be appropriate targets for piloting rehabilitation interventions, such as noninvasive brain stimulation, when the goal is to improve poststroke haptic performance. PMID:26759788

  11. Frontoparietal white matter integrity predicts haptic performance in chronic stroke.

    PubMed

    Borstad, Alexandra L; Choi, Seongjin; Schmalbrock, Petra; Nichols-Larsen, Deborah S

    2016-01-01

    strongly correlated with the shared variance across tracts in the control, but not in the poststroke participants. A moderate to good relationship was found between ipsilesional T-M1 MD and affected hand HASTe score (r = - 0.62, p = 0.006) and less affected hand HASTe score (r = - 0.53, p = 0.022). Regression analysis revealed approximately 90% of the variance in affected hand HASTe score was predicted by the white matter integrity in the frontoparietal network (as indexed by MD) in poststroke participants while 87% of the variance in HASTe score was predicted in control participants. This study demonstrates the importance of frontoparietal white matter in mediating haptic performance and specifically identifies that T-M1 and precuneus interhemispheric tracts may be appropriate targets for piloting rehabilitation interventions, such as noninvasive brain stimulation, when the goal is to improve poststroke haptic performance. PMID:26759788

  12. Investigation of the relative significance of individual environmental parameters to sonar performance prediction uncertainty

    NASA Astrophysics Data System (ADS)

    Wang, Ding; Xu, Wen; Schmidt, Henrik

    2002-11-01

    A large part of sonar performance prediction uncertainty is associated with the uncertain ocean acoustic environment. Optimal in situ measurement strategy, i.e. adaptively capturing the most critical uncertain environmental parameters within operational constrains can minimize the sonar performance prediction uncertainty. Understanding the relative significance of individual environmental parameters to sonar performance prediction uncertainty is fundamental to the heuristics to determine the most critical environmental parameters. Based on this understanding, the optimal parametrization of ocean acoustic environments can be defined, which will significantly simplify the adaptively sampling pattern. As an example, the matched-field processing is used to localize an unknown sound source position in a realistic ocean environment. Typical shallow water environmental models are used with some of the properties being stochastic variables. The ratio of the main lobe peak to the maximum side lobe peak of the ambiguity function and the main lobe peak displacement due to mismatch are chosen as performance metrics, respectively, in two different scenarios. The relative significance of some environmental parameters such as sediment thickness, weights of empirical orthogonal functions (EOFs) has been computed. Some preliminary results are discussed.

  13. The dark and bright sides of self-efficacy in predicting learning, innovative and risky performances.

    PubMed

    Salanova, Marisa; Lorente, Laura; Martínez, Isabel M

    2012-11-01

    The objective of this study is to analyze the different role that efficacy beliefs play in the prediction of learning, innovative and risky performances. We hypothesize that high levels of efficacy beliefs in learning and innovative performances have positive consequences (i.e., better academic and innovative performance, respectively), whereas in risky performances they have negative consequences (i.e., less safety performance). To achieve this objective, three studies were conducted, 1) a two-wave longitudinal field study among 527 undergraduate students (learning setting), 2) a three-wave longitudinal lab study among 165 participants performing innovative group tasks (innovative setting), and 3) a field study among 228 construction workers (risky setting). As expected, high levels of efficacy beliefs have positive or negative consequences on performance depending on the specific settings. Unexpectedly, however, we found no time x self-efficacy interaction effect over time in learning and innovative settings. Theoretical and practical implications within the social cognitive theory of A. Bandura framework are discussed. PMID:23156920

  14. Performance predictions of VAWTs with NLF airfoil blades

    SciTech Connect

    Masson, C.; Leclerc, C.; Paraschivoiu, I.

    1997-02-01

    The successful design of an efficient Vertical Axis Wind Turbine (VAWT) can be obtained only when appropriate airfoil sections have been selected. Most VAWTs currently operating worldwide use blades of symmetrical NACA airfoil series. As these blades were designed for aviation applications, Sandia National Laboratories developed a family of airfoils specifically designed for VAWTs in order to decrease the Cost of Energy (COE) of the VAWT (Berg, 1990). Objectives formulated for the blade profile were: modest values of maximum lift coefficient, low drag at low angle of attack, high drag at high angle of attack, sharp stall, and low thickness-to-chord ratio. These features are similar to those of Natural Laminar Flow airfoils (NLF) and gave birth to the SNLA airfoil series. This technical brief illustrates the benefits and losses resulting from using NLF airfoils on VAWT blades. To achieve this goal, the streamtube model of Paraschivoiu (1988) is used to predict the performance of VAWTs equipped with blades of various airfoil shapes. The airfoil shapes considered are the conventional airfoils NACA 0018 and NACA 0021, and the SNLA 0018/50 airfoil designed at Sandia. Furthermore, the potential benefit of reducing the airfoil drag is clearly illustrated by the presentation of the individual contributions of lift and drag to power.

  15. Hydrogen recombination kinetics and nuclear thermal rocket performance prediction

    SciTech Connect

    Wetzel, K.K.; Solomon, W.C.

    1994-07-01

    The rate constants for the hydrogen three-body collisional recombination reaction with atomic and molecular hydrogen acting as third bodies have been determined by numerous investigators during the past 30 yr, but these rates exhibit significant scatter. The discrepancies in the rate constants determined by different investigators are as great as two orders of magnitude in the temperature range of interest for nuclear thermal rocket (NTR) operation, namely, 2000-3300 K. The impact of this scatter on our ability to predict the specific impulse (I(sub sp)) delivered by a 30-klbf NTR has been determined for chamber pressures and temperatures from, respectively, 20-1000 psia and 2700-3300 K. The variation in I(sub sp) produced by using the different rate constants is as great as 10%, or 100 s. This variation also obscures the influence of chamber pressure on I(sub sp); using fast kinetics, low pressures yield significantly improved performance, while using slow or nominal kinetics, the pressure dependence of I(sub sp) is negligible. Because the flow composition freezes at very small area ratios, optimization of the nozzle contour in the near-throat region maximizes recombination. Vibrational relaxation is found to produce negligible losses in I(sub sp). 36 refs.

  16. Individual Differences in Nonsymbolic Ratio Processing Predict Symbolic Math Performance.

    PubMed

    Matthews, Percival G; Lewis, Mark Rose; Hubbard, Edward M

    2016-02-01

    What basic capacities lay the foundation for advanced numerical cognition? Are there basic nonsymbolic abilities that support the understanding of advanced numerical concepts, such as fractions? To date, most theories have posited that previously identified core numerical systems, such as the approximate number system (ANS), are ill-suited for learning fraction concepts. However, recent research in developmental psychology and neuroscience has revealed a ratio-processing system (RPS) that is sensitive to magnitudes of nonsymbolic ratios and may be ideally suited for supporting fraction concepts. We provide evidence for this hypothesis by showing that individual differences in RPS acuity predict performance on four measures of mathematical competence, including a university entrance exam in algebra. We suggest that the nonsymbolic RPS may support symbolic fraction understanding much as the ANS supports whole-number concepts. Thus, even abstract mathematical concepts, such as fractions, may be grounded not only in higher-order logic and language, but also in basic nonsymbolic processing abilities. PMID:26710824

  17. Visualization of Force Fields in Protein Structure Prediction

    SciTech Connect

    Crawford, Clark; Kreylos, Oliver; Hamann, Bernd; Crivelli, Silvia

    2005-04-26

    The force fields used in molecular computational biology are not mathematically defined in such a way that their mathematical representation would facilitate the straightforward application of volume visualization techniques. To visualize energy, it is necessary to define a spatial mapping for these fields. Equipped with such a mapping, we can generate volume renderings of the internal energy states in a molecule. We describe our force field, the spatial mapping that we used for energy, and the visualizations that we produced from this mapping. We provide images and animations that offer insight into the computational behavior of the energy optimization algorithms that we employ.

  18. Comparison of Flux-Surface Aligned Curvilinear Coordinate Systems and Neoclassical Magnetic Field Predictions

    NASA Astrophysics Data System (ADS)

    Collart, T. G.; Stacey, W. M.

    2015-11-01

    Several methods are presented for extending the traditional analytic ``circular'' representation of flux-surface aligned curvilinear coordinate systems to more accurately describe equilibrium plasma geometry and magnetic fields in DIII-D. The formalism originally presented by Miller is extended to include different poloidal variations in the upper and lower hemispheres. A coordinate system based on separate Fourier expansions of major radius and vertical position greatly improves accuracy in edge plasma structure representation. Scale factors and basis vectors for a system formed by expanding the circular model minor radius can be represented using linear combinations of Fourier basis functions. A general method for coordinate system orthogonalization is presented and applied to all curvilinear models. A formalism for the magnetic field structure in these curvilinear models is presented, and the resulting magnetic field predictions are compared against calculations performed in a Cartesian system using an experimentally based EFIT prediction for the Grad-Shafranov equilibrium. Supported by: US DOE under DE-FG02-00ER54538.

  19. Burst muscle performance predicts the speed, acceleration, and turning performance of Anna’s hummingbirds

    PubMed Central

    Segre, Paolo S; Dakin, Roslyn; Zordan, Victor B; Dickinson, Michael H; Straw, Andrew D; Altshuler, Douglas L

    2015-01-01

    Despite recent advances in the study of animal flight, the biomechanical determinants of maneuverability are poorly understood. It is thought that maneuverability may be influenced by intrinsic body mass and wing morphology, and by physiological muscle capacity, but this hypothesis has not yet been evaluated because it requires tracking a large number of free flight maneuvers from known individuals. We used an automated tracking system to record flight sequences from 20 Anna's hummingbirds flying solo and in competition in a large chamber. We found that burst muscle capacity predicted most performance metrics. Hummingbirds with higher burst capacity flew with faster velocities, accelerations, and rotations, and they used more demanding complex turns. In contrast, body mass did not predict variation in maneuvering performance, and wing morphology predicted only the use of arcing turns and high centripetal accelerations. Collectively, our results indicate that burst muscle capacity is a key predictor of maneuverability. DOI: http://dx.doi.org/10.7554/eLife.11159.001 PMID:26583753

  20. Technique for Predicting the Radio Frequency Field Strength Inside an Enclosure

    NASA Technical Reports Server (NTRS)

    Hallett, Michael P.; Reddell, Jerry P.

    1997-01-01

    This technical memo represents a simple analytical technique for predicting the Radio Frequency (RF) field inside an enclosed volume in which radio frequency occurs. The technique was developed to predict the RF field strength within a launch vehicle fairing in which some payloads desire to launch with their telemetry transmitter radiating. This technique considers both the launch vehicle and the payload aspects.

  1. Prediction of mandibular rotation: an empirical test of clinician performance.

    PubMed

    Baumrind, S; Korn, E L; West, E E

    1984-11-01

    An experiment was conducted in an attempt to determine empirically how effective a number of expert clinicians were at differentiating "backward rotators" from "forward rotators" on the basis of head-film information which might reasonably have been available to them prior to instituting treatment for the correction of Class II malocclusion. As a result of a previously reported ongoing study, pre- and posttreatment head films were available for 188 patients treated in the mixed dentition for the correction of Class II malocclusion and for 50 untreated Class II subjects. These subjects were divided into 14 groups (average size of group, 17; range, 6 to 23) solely on the basis of type of treatment and the clinician from whose clinic the records had originated. From within each group, we selected the two or three subjects who had exhibited the most extreme backward rotation and the two or three subjects who had exhibited the most extreme forward rotation of the mandible during the interval between films. The sole criterion for classification was magnitude of change in the mandibular plane angle of Downs between the pre- and posttreatment films of each patient. The resulting sample contained 32 backward-rotator subjects and 32 forward-rotator subjects. Five expert judges (mean clinical experience, 28 years) were asked to identify the backward-rotator subjects by examination of the pretreatment films. The findings may be summarized as follows: (1) No judge performed significantly better than chance. (2) There was strong evidence that the judges used a shared, though relatively ineffective, set of rules in making their discriminations between forward and backward rotators. (3) Statistical analysis of the predictive power of a set of standard cephalometric measurements which had previously been made for this set of subjects indicated that the numerical data also failed to identify potential backward rotators at a rate significantly better than chance. We infer from these

  2. Using a bias aware Ensemble Kalman Filter to predict soil moisture in a layered field

    NASA Astrophysics Data System (ADS)

    Erdal, Daniel; Neuweiler, Insa; Wollschläger, Ute

    2014-05-01

    When modeling and predicting flow in the unsaturated zone, one problem are the strong heterogeneities in the system that occur on all scales and have in principle to be accounted for in the flow model. In general, however, our knowledge of subsurface structure often is poor and the internal structure of the model may be subject to strong simplifications. When modeling flow, models may have an inherent modeling error. In this work, we consider external bias corrections to account for unresolved subsurface structure within an Ensemble Kalman Filter (EnKF) state and parameter estimation process. We assimilate and predict local spatially distributed data from a heterogeneous soil using a homogeneous flow model. We apply the data assimilation scheme to a set of TDR observations taken over a long series in a layered plot (published in Wollschlaeger et al, 2009). Different assimilation and prediction intervals are tested as well as different parameter models. It is shown that the homogeneous model itself cannot be used to make prediction with the EnKF. When the bias corrections are introduced, however, the result clearly improves and the resulting model can be used to make reasonable predictions of local water content. It is also shown that in the proposed assimilation setup, the commonly used van Genuchten parameter model does not result in a better performance than the much simpler Russo-Gardner model, hence suggesting that the simpler model should be used for the assimilation. It will also be demonstrated that models that include the layering explicitly, might not lead to improved predictions, if the heterogeneous structure is not implemented correctly. Literature: Wollschlaeger, U., T. Pfaff and K. Roth (2009). Field-scale apparent hydraulic parameterisation obtained from TDR time series and inverse modelling, Hydrol. Earth. Sci., 13, 1953-1966.

  3. Predicting cotton yield of small field plots in a cotton breeding program using UAV imagery data

    NASA Astrophysics Data System (ADS)

    Maja, Joe Mari J.; Campbell, Todd; Camargo Neto, Joao; Astillo, Philip

    2016-05-01

    One of the major criteria used for advancing experimental lines in a breeding program is yield performance. Obtaining yield performance data requires machine picking each plot with a cotton picker, modified to weigh individual plots. Harvesting thousands of small field plots requires a great deal of time and resources. The efficiency of cotton breeding could be increased significantly while the cost could be decreased with the availability of accurate methods to predict yield performance. This work is investigating the feasibility of using an image processing technique using a commercial off-the-shelf (COTS) camera mounted on a small Unmanned Aerial Vehicle (sUAV) to collect normal RGB images in predicting cotton yield on small plot. An orthonormal image was generated from multiple images and used to process multiple, segmented plots. A Gaussian blur was used to eliminate the high frequency component of the images, which corresponds to the cotton pixels, and used image subtraction technique to generate high frequency pixel images. The cotton pixels were then separated using k-means cluster with 5 classes. Based on the current work, the calculated percentage cotton area was computed using the generated high frequency image (cotton pixels) divided by the total area of the plot. Preliminary results showed (five flights, 3 altitudes) that cotton cover on multiple pre-selected 227 sq. m. plots produce an average of 8% which translate to approximately 22.3 kgs. of cotton. The yield prediction equation generated from the test site was then use on a separate validation site and produced a prediction error of less than 10%. In summary, the results indicate that a COTS camera with an appropriate image processing technique can produce results that are comparable to expensive sensors.

  4. Estimating the magnitude of prediction uncertainties for field-scale P loss models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Models are often used to predict phosphorus (P) loss from agricultural fields. While it is commonly recognized that model predictions are inherently uncertain, few studies have addressed prediction uncertainties using P loss models. In this study, an uncertainty analysis for the Annual P Loss Estima...

  5. Optimal sampling and sample preparation for NIR-based prediction of field scale soil properties

    NASA Astrophysics Data System (ADS)

    Knadel, Maria; Peng, Yi; Schelde, Kirsten; Thomsen, Anton; Deng, Fan; Humlekrog Greve, Mogens

    2013-04-01

    The representation of local soil variability with acceptable accuracy and precision is dependent on the spatial sampling strategy and can vary with a soil property. Therefore, soil mapping can be expensive when conventional soil analyses are involved. Visible near infrared spectroscopy (vis-NIR) is considered a cost-effective method due to labour savings and relative accuracy. However, savings may be offset by the costs associated with number of samples and sample preparation. The objective of this study was to find the most optimal way to predict field scale total organic carbon (TOC) and texture. To optimize the vis-NIR calibrations the effects of sample preparation and number of samples on the predictive ability of models with regard to the spatial distribution of TOC and texture were investigated. Conditioned Latin hypercube sampling (cLHs) method was used to select 125 sampling locations from an agricultural field in Denmark, using electromagnetic induction (EMI) and digital elevation model (DEM) data. The soil samples were scanned in three states (field moist, air dried and sieved to 2 mm) with a vis-NIR spectrophotometer (LabSpec 5100, ASD Inc., USA). The Kennard-Stone algorithm was applied to select 50 representative soil spectra for the laboratory analysis of TOC and texture. In order to investigate how to minimize the costs of reference analysis, additional smaller subsets (15, 30 and 40) of samples were selected for calibration. The performance of field calibrations using spectra of soils at the three states as well as using different numbers of calibration samples was compared. Final models were then used to predict the remaining 75 samples. Maps of predicted soil properties where generated with Empirical Bayesian Kriging. The results demonstrated that regardless the state of the scanned soil, the regression models and the final prediction maps were similar for most of the soil properties. Nevertheless, as expected, models based on spectra from field

  6. Performance predictions of a focused ion beam from a laser cooled and compressed atomic beam

    SciTech Connect

    Haaf, G. ten; Wouters, S. H. W.; Vredenbregt, E. J. D.; Mutsaers, P. H. A.; Geer, S. B. van der

    2014-12-28

    Focused ion beams are indispensable tools in the semiconductor industry because of their ability to image and modify structures at the nanometer length scale. Here, we report on performance predictions of a new type of focused ion beam based on photo-ionization of a laser cooled and compressed atomic beam. Particle tracing simulations are performed to investigate the effects of disorder-induced heating after ionization in a large electric field. They lead to a constraint on this electric field strength which is used as input for an analytical model which predicts the minimum attainable spot size as a function of, amongst others, the flux density of the atomic beam, the temperature of this beam, and the total current. At low currents (I < 10 pA), the spot size will be limited by a combination of spherical aberration and brightness, while at higher currents, this is a combination of chromatic aberration and brightness. It is expected that a nanometer size spot is possible at a current of 1 pA. The analytical model was verified with particle tracing simulations of a complete focused ion beam setup. A genetic algorithm was used to find the optimum acceleration electric field as a function of the current. At low currents, the result agrees well with the analytical model, while at higher currents, the spot sizes found are even lower due to effects that are not taken into account in the analytical model.

  7. The Large Binocular Camera image simulator: predicting the performances of LBC

    NASA Astrophysics Data System (ADS)

    Grazian, Andrea; Fontana, Adriano; De Santis, Cristian; Gallozzi, Stefano; Giallongo, Emanuele

    2004-09-01

    The LBC (Large Binocular Camera) Image Simulator is a package for generating artificial images in the typical FITS format. It operates on real or artificial images, simulating the expected performances of real instruments including several observing conditions (filters, air-mass, flat-field, exposure time) and creating images with the LBC instrumental artifacts (optical deformations, noise, CCD architectures). This simulator can be used also to produce artificial images for other existing and future telescopes, since it is very flexible on its structure. The main aim of LBCSIM is to support the development of pipeline and data analysis procedure able to cope with wide field imaging and fast reduction of huge amount of photometric data. The software consists of three stand alone programs written in C language, using IRAF and running under Linux OS. The LBC Image Simulator is built with particular attention to the Virtual Observatory and Data Grid applications. In this paper, we first describe the software, the performances and several tests carried out before the public release and some examples for the users. In particular, we compared the Hubble Deep Field South (HDFS) as seen by FORS1 with a simulated image and found that the agreement is good. Then, we use this software to predict the expected performances of the LBC instrument by means of realistic simulations of deep field observations with the LBT telescope.

  8. Does High School Performance Predict College Math Placement?

    ERIC Educational Resources Information Center

    Kowski, Lynne E.

    2013-01-01

    Predicting student success has long been a question of interest for postsecondary admission counselors throughout the United States. Past research has examined the validity of several methods designed for predicting undergraduate success. High school record, standardized test scores, extracurricular activities, and combinations of all three have…

  9. Predicting polarization performance of high-numerical aperture inspection lenses

    NASA Astrophysics Data System (ADS)

    Fahr, Stephan; Werschnik, Jan; Bening, Matthias; Uhlendorf, Kristina

    2015-09-01

    Along the course of increasing through-put and improving signal to noise ratio in optical wafer and mask inspection, demands on wave front aberrations and polarization characteristics are ever increasing. The system engineers and optical designers involved in the development of such optical systems will be responsible for specifying the quality of the optical material and the mechanical tolerances. Among optical designers it is well established how to estimate the wave front error of assembled and adjusted optical devices via sensitivity or Monte-Carlo analysis. However, when compared with the scalar problem of wave front estimation, the field of polarization control deems to pose a more complex problem due to its vectorial nature. Here we show our latest results in how to model polarization affecting aspects. In the realm of high numerical aperture (NA) inspection optics we will focus on the impact of coatings, stress induced birefringence due to non-perfect lens mounting, and finally the birefringence of the optical material. With all these tools at hand, we have a more complete understanding of the optical performance of our assembled optical systems. Moreover, we are able to coherently develop optical systems meeting demanding wave front criteria as well as high end polarization specifications.

  10. Ring-field TMA for PRISMA: theory, optical design, and performance measurements

    NASA Astrophysics Data System (ADS)

    Calamai, Luciano; Barsotti, Stefano; Fossati, Enrico; Formaro, Roberto; Thompson, Kevin P.

    2015-09-01

    PRISMA (PRecursore IperSpettrale della Missione Applicativa) Hyperspectral Payload is an Electro-Optical instrument developed in Selex ES for the dedicated ASI (Italian Space Agency) mission for Earth observation. The performance requirements for this mission are stringent and have led to an instrument design that is based on a Ring-Field Three Mirror Anastigmat (Ring-Field TMA), a two channel prism dispersion based spectrometer (VNIR and SWIR), and a Panchromatic Camera. The Ring-Field TMA contains three mirrors (two conics and one conic with some higher order correction). Exceptional performance has been achieved by not only introducing 3rd order astigmatism to balance the 5th astigmatism at the ring field zone as is traditional in an Offner-type design but, additionally, 3rd order coma has been controlled to align the balance of the linear and field cubic coma terms at the same ring field zone. The predicted wavefront performance of the design over the field of view will be highlighted. An assembly and alignment procedure for the Ring-Field TMA has been developed from the results of the sensitivity and tolerances analysis. The tilt and decenter sensitivity of the design form is nearly exclusively determined by 3rd order binodal astigmatism. The nodal position is linear with perturbation, which greatly simplifies the decisions on alignment compensators. The manufactured mirrors of the Ring-Field TMA have been aligned at Selex ES and as will be reported the preliminary results in terms of optical quality are in good agreement with the predicted as-built performance, both on-axis and in the field.

  11. Predicting the Suitability of Fields for Rainfed Corn Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Timely irrigation of corn increases yield and reduces earworm damage and aflatoxin production. However, the costs of fuel, fertilizers, and other crop inputs have increased greatly in recent years and many producers cannot afford the investment required to be able to irrigate all of their fields. Wi...

  12. Does intrinsic motivation fuel the prosocial fire? Motivational synergy in predicting persistence, performance, and productivity.

    PubMed

    Grant, Adam M

    2008-01-01

    Researchers have obtained conflicting results about the role of prosocial motivation in persistence, performance, and productivity. To resolve this discrepancy, I draw on self-determination theory, proposing that prosocial motivation is most likely to predict these outcomes when it is accompanied by intrinsic motivation. Two field studies support the hypothesis that intrinsic motivation moderates the association between prosocial motivation and persistence, performance, and productivity. In Study 1, intrinsic motivation strengthened the relationship between prosocial motivation and the overtime hour persistence of 58 firefighters. In Study 2, intrinsic motivation strengthened the relationship between prosocial motivation and the performance and productivity of 140 fundraising callers. Callers who reported high levels of both prosocial and intrinsic motivations raised more money 1 month later, and this moderated association was mediated by a larger number of calls made. I discuss implications for theory and research on work motivation. PMID:18211134

  13. Field theoretical prediction of a property of the tropical cyclone

    NASA Astrophysics Data System (ADS)

    Spineanu, F.; Vlad, M.

    2014-01-01

    The large scale atmospheric vortices (tropical cyclones, tornadoes) are complex physical systems combining thermodynamics and fluid-mechanical processes. The late phase of the evolution towards stationarity consists of the vorticity concentration, a well known tendency to self-organization , an universal property of the two-dimensional fluids. It may then be expected that the stationary state of the tropical cyclone has the same nature as the vortices of many other systems in nature: ideal (Euler) fluids, superconductors, Bose-Einsetin condensate, cosmic strings, etc. Indeed it was found that there is a description of the atmospheric vortex in terms of a classical field theory. It is compatible with the more conventional treatment based on conservation laws, but the field theoretical model reveals properties that are almost inaccessible to the conventional formulation: it identifies the stationary states as being close to self-duality. This is of highest importance: the self-duality is known to be the origin of all coherent structures known in natural systems. Therefore the field theoretical (FT) formulation finds that the cuasi-coherent form of the atmospheric vortex (tropical cyclone) at stationarity is an expression of this particular property. In the present work we examine a strong property of the tropical cyclone, which arises in the FT formulation in a natural way: the equality of the masses of the particles associated to the matter field and respectively to the gauge field in the FT model is translated into the equality between the maximum radial extension of the tropical cyclone and the Rossby radius. For the cases where the FT model is a good approximation we calculate characteristic quantities of the tropical cyclone and find good comparison with observational data.

  14. MRS Photodiode, LED and extruded scintillator performance in magnetic field

    SciTech Connect

    Beznosko, D.; Blazey, G.; Dyshkant, A.; Francis, K.; Kubik, D.; Rykalin, V.; Zutshi, V.; /Northern Illinois U.

    2005-05-01

    The experimental results on the performance of the MRS (Metal/Resistor/Semiconductor) photodiode in the strong magnetic field of 4.4T, and the possible impact of the quench of the magnet at 4.5T on sensor's operation are reported. In addition, the experimental results on the performance of the extruded scintillator and WLS fiber, and various LEDs in the magnetic fields of 1.8T and 2.3T respectively, are detailed. The measurement method used is being described.

  15. Prediction of Human Glomerular Filtration Rate from Preterm Neonates to Adults: Evaluation of Predictive Performance of Several Empirical Models.

    PubMed

    Mahmood, Iftekhar; Staschen, Carl-Michael

    2016-03-01

    The objective of this study was to evaluate the predictive performance of several allometric empirical models (body weight dependent, age dependent, fixed exponent 0.75, a data-dependent single exponent, and maturation models) to predict glomerular filtration rate (GFR) in preterm and term neonates, infants, children, and adults without any renal disease. In this analysis, the models were developed from GFR data obtained from inulin clearance (preterm neonates to adults; n = 93) and the predictive performance of these models were evaluated in 335 subjects (preterm neonates to adults). The primary end point was the prediction of GFR from the empirical allometric models and the comparison of the predicted GFR with measured GFR. A prediction error within ±30% was considered acceptable. Overall, the predictive performance of the four models (BDE, ADE, and two maturation models) for the prediction of mean GFR was good across all age groups but the prediction of GFR in individual healthy subjects especially in neonates and infants was erratic and may be clinically unacceptable. PMID:26801317

  16. Diagnostic Performance 1 H after Simulation Training Predicts Learning

    ERIC Educational Resources Information Center

    Consoli, Anna; Fraser, Kristin; Ma, Irene; Sobczak, Matthew; Wright, Bruce; McLaughlin, Kevin

    2013-01-01

    Although simulation training improves post-training performance, it is unclear how well performance soon after simulation training predicts longer term outcomes (i.e., learning). Here our objective was to assess the predictive value of performance 1 h post-training of performance 6 weeks later. We trained 84 first year medical students a simulated…

  17. Magnetic field of the planet Uranus: predictions, measurements, and interpretation

    SciTech Connect

    Dolginov, S.S.

    1987-09-01

    The magnitude and tilt of the eccentric dipole of Uranus are examined in the framework of a processing dynamo model. It is shown that the unique parameters of the magnetic field of Uranus are connected with the fact that, unlike the other planets, the magnetic field of Uranus is generated in two bordering regions whose highly conducting materials differ sharply in density: the density anti rho = 12 g x cm/sup -3/ in a core with an upper boundary r = 0.3R/sub U/, and anti rho = 3.1 g x cm/sup -3/ in an ocean with an upper boundary r = 0.6R/sub U/. The upper boundary of the magnetically active region in the ocean is determined by the magnetic pressure P = 1.9 Mbar, at which the ocean material is metallized.

  18. Influence of grid bar shape on field cleaner performance - field testing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A test was conducted to evaluate the influence of grid bar cross sectional shape on cotton stripper field cleaner performance in terms of cleaning efficiency, seed cotton loss, and fiber and yarn quality. Three field cleaner configurations were tested on a cotton stripper harvester operating under f...

  19. Evaluation of asphalt-rubber membrane field performance

    NASA Astrophysics Data System (ADS)

    Shuler, S.; Gallaway, B. M.; Epps, J. A.

    1982-05-01

    This report presents a record of asphalt-rubber membrane field performance in Texas. An evaluation of performance is presented for forty-five separate projects in thirteen state highway districts. Approximately 850 lane miles of highways are represented by materials constructed as stress absorbing membranes (asphalt-rubber seal coats beneath asphalt concrete overlay). All projects reviewed were constructed between June, 1976 and September, 1981.

  20. In-Flight Performance of Wide Field Camera 3

    NASA Technical Reports Server (NTRS)

    Kimble, Randy

    2010-01-01

    Wide Field Camera 3 (WFC3), a powerful new UVNisible/IR imager, was installed into HST during Servicing Mission 4. After a successful commissioning in the Servicing Mission Orbital Verification program, WFC3 has been engaged in an exciting program of scientific observations. I review here the in-flight scientific performance of the instrument, addressing such topics as image quality, sensitivity, detector performance, and stability.

  1. First Assessments of Predicted ICESat-2 Performance Using Aircraft Data

    NASA Technical Reports Server (NTRS)

    Neumann, Thomas; Markus, Thorsten; Cook, William; Hancock, David; Brenner, Anita; Kelly, Brunt; DeMarco, Eugenia; Reed, Daniel; Walsh, Kaitlin

    2012-01-01

    The Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) is a next-generation laser altimeter designed to continue key observations of ice sheet elevation change, sea ice freeboard, vegetation canopy height, earth surface elevation, and sea surface height. Scheduled for launch in mid-2016, ICESat-2 will use a high repetition rate (10 kHz), small footprint (10 m nominal ground diameter) laser, and a single-photon-sensitive detection strategy (photon counting) to measure precise range to the earth's surface. Using green light (532 nm), the six beams of ICESat-2 will provide improved spatial coverage compared with the single beam of ICESat, while the differences in transmit energy among the beams provide a large dynamic range. The six beams are arranged into three pairs of beams which allow slopes to measured on an orbit-by-orbit basis. In order to evaluate models of predicted ICESat-2 performance and provide ICESat-2-like data for algorithm development, an airborne ICESat-2 simulator was developed and first flown in 2010. This simulator, the Multiple Altimeter Beam Experimental Lidar (MABEL) was most recently deployed to Iceland in April 2012 and collected approx 85 hours of science data over land ice, sea ice, and calibration targets. MABEL uses a similar photon-counting measurement strategy to what will be used on ICESat-2. MABEL collects data in 16 green channels and an additional 8 channels in the infrared aligned across the direction of flight. By using NASA's ER-2 aircraft flying at 20km altitude, MABEL flies as close to space as is practical, and collects data through approx 95% of the atmosphere. We present background on the MABEL instrument, and data from the April 2012 deployment to Iceland. Among the 13 MABEL flights, we collected data over the Greenland ice sheet interior and outlet glaciers in the southwest and western Greenland, sea ice data over the Nares Strait and Greenland Sea, and a number of small glaciers and ice caps in Iceland and Svalbard

  2. Soil and Nitrogen redistribution in a small Mediterranean cereal field: modelling predictions and field measurements

    NASA Astrophysics Data System (ADS)

    López-Vicente, Manuel, , Dr.; Quijano, M. Sc. Laura; Gaspar, Leticia, , Dr.; Palazón, M. Sc. Leticia; Navas, Ana, , Dr.

    2015-04-01

    Cultivation is one of the main factors triggering soil erosion and the loss of fertile soil accelerates and in some cases causes soil degradation and crop yield reduction. Patterns of erosion, delivery and deposition of soil particles appear to be closely linked to that of soil nutrients. In this study, we assess the rates of soil and nutrient (soil nitrogen) redistribution and budget in a rain-fed cereal experimental plot (0.65 ha; Ebro river basin, NE Spain) caused by water erosion. The study area has a mean slope of 7%, it is classed as a closed-hydrological unit due to the cutting-connectivity effect of the landscape linear elements (LLEs), it has only one outlet and runoff directly reach La Reina gully. Climate is continental Mediterranean with two humid periods (average annual rainfall depth of 556 mm). Rainfall events of high intensity happen in June, July, September and October, with average values of maximum rainfall intensity in 30 min higher than 4 mm h-1 and above 6 mm h-1 in October. Soils are classified as Haplic Calcisols with an average and maximum values of soil organic matter of 1.5% and 2.4% respectively, high carbonate contents (ca. 39%) and texture is silt loam. The field has been cultivated for more than 150 years and consequently the soil is thoroughly mixed in the plough layer (25-30 cm). The cereal field was last harvested in June 2007 and from that date onwards the field has remained fallow for research purposes. Before fallowing the field was managed with minimum tillage during 15 years. Vegetation clearance practices were implemented to prevent scrub growth and so the soil surface has remained almost bare since that date. A total of 222 topsoil (5 cm depth) samples were collected following a regular 5x5 metre grid. Soil nitrogen content (%) was determined by the dry combustion method using a Leco TruSpec carbon and nitrogen analyzer (LECO Corporation, St. Joseph, MI, USA). Soil nitrogen was detected by determining the NOx gas evolved

  3. A paradigm for data-driven predictive modeling using field inversion and machine learning

    NASA Astrophysics Data System (ADS)

    Parish, Eric J.; Duraisamy, Karthik

    2016-01-01

    We propose a modeling paradigm, termed field inversion and machine learning (FIML), that seeks to comprehensively harness data from sources such as high-fidelity simulations and experiments to aid the creation of improved closure models for computational physics applications. In contrast to inferring model parameters, this work uses inverse modeling to obtain corrective, spatially distributed functional terms, offering a route to directly address model-form errors. Once the inference has been performed over a number of problems that are representative of the deficient physics in the closure model, machine learning techniques are used to reconstruct the model corrections in terms of variables that appear in the closure model. These reconstructed functional forms are then used to augment the closure model in a predictive computational setting. As a first demonstrative example, a scalar ordinary differential equation is considered, wherein the model equation has missing and deficient terms. Following this, the methodology is extended to the prediction of turbulent channel flow. In both of these applications, the approach is demonstrated to be able to successfully reconstruct functional corrections and yield accurate predictive solutions while providing a measure of model form uncertainties.

  4. In-situ estimates of environmental uncertainty on sonar performance prediction

    NASA Astrophysics Data System (ADS)

    Heaney, Kevin D.

    2005-04-01

    Oceanographic and geo-acoustic variability in the shallow water can dominate acoustic propagation. Sonar performance predictions using archival sound speed and geo-acoustic information do not contain any information about variability or uncertainty in the environment and its likely impact on sonar performance prediction. Using measurements from the NATO Undersea Research Centres BOUNDARY 2003 sea test, an approach is presented that estimates the uncertainty and transfers it through the acoustic propagation and the sonar equation to sonar performance. The sound speed field is characterized by an Empirical Orthogonal Function decomposition of the measured profiles. The geo-acoustic uncertainty is considered to be a normal distribution around the inverted geo-acoustic parameters (from 4 separate inversions). Dynamic ambient noise variability is measured from the array beamformer output. Uncertainty in propagation is quantified in terms of sound speed, geo-acoustic, and ambient noise uncertainty. The uncertainty in sonar performance, due to environmental uncertainty, is then displayed to the operator. [Work supported by the ONR Capturing Uncertainty DRI.

  5. Theoretical Predictions and Experimental Assessments of the Performance of Alumina RF Windows

    SciTech Connect

    Karen Ann Cummings

    1998-07-01

    Radio frequency (RF) windows are the most likely place for catastrophic failure to occur in input power couplers for particle accelerators. Reliable RF windows are essential for the success of the Accelerator Production of Tritium (APT) program because there are over 1000 windows on the accelerator, and it takes more than one day to recover from a window failure. The goals of this research are to analytically predict the lifetime of the windows, to develop a conditioning procedure, and to evaluate the performance of the RF windows. The analytical goal is to predict the lifetime of the windows. The probability of failure is predicted by the combination of a finite element model of the window, Weibull probabilistic analysis, and fracture mechanics. The window assembly is modeled in a finite element electromagnetic code in order to calculate the electric fields in the window. The geometry (i.e. mesh) and electric fields are input into a translator program to generate the mesh and boundary conditions for a finite element thermal structural code. The temperatures and stresses are determined in the thermal/structural code. The geometry and thermal structural results are input into another translator program to generate an input file for the reliability code. Material, geometry and service data are also input into the reliability code. To obtain accurate Weibull and fatigue data for the analytical model, four point bend tests were done. The analytical model is validated by comparing the measurements to the calculations. The lifetime of the windows is then determined using the reliability code. The analytical model shows the window has a good thermal mechanical design and that fast fracture is unlikely to occur below a power level of 9 Mw. The experimental goal is to develop a conditioning procedure and evaluate the performance of RF windows. During the experimental evaluation, much was learned about processing of the windows to improve the RF performance. Methods of

  6. Prediction of hybrid performance in maize using molecular markers and joint analyses of hybrids and parental inbreds.

    PubMed

    Schrag, Tobias A; Möhring, Jens; Melchinger, Albrecht E; Kusterer, Barbara; Dhillon, Baldev S; Piepho, Hans-Peter; Frisch, Matthias

    2010-01-01

    The identification of superior hybrids is important for the success of a hybrid breeding program. However, field evaluation of all possible crosses among inbred lines requires extremely large resources. Therefore, efforts have been made to predict hybrid performance (HP) by using field data of related genotypes and molecular markers. In the present study, the main objective was to assess the usefulness of pedigree information in combination with the covariance between general combining ability (GCA) and per se performance of parental lines for HP prediction. In addition, we compared the prediction efficiency of AFLP and SSR marker data, estimated marker effects separately for reciprocal allelic configurations (among heterotic groups) of heterozygous marker loci in hybrids, and imputed missing AFLP marker data for marker-based HP prediction. Unbalanced field data of 400 maize dent x flint hybrids from 9 factorials and of 79 inbred parents were subjected to joint analyses with mixed linear models. The inbreds were genotyped with 910 AFLP and 256 SSR markers. Efficiency of prediction (R (2)) was estimated by cross-validation for hybrids having no or one parent evaluated in testcrosses. Best linear unbiased prediction of GCA and specific combining ability resulted in the highest efficiencies for HP prediction for both traits (R (2) = 0.6-0.9), if pedigree and line per se data were used. However, without such data, HP for grain yield was more efficiently predicted using molecular markers. The additional modifications of the marker-based approaches had no clear effect. Our study showed the high potential of joint analyses of hybrids and parental inbred lines for the prediction of performance of untested hybrids. PMID:19916002

  7. Aerodynamic Performance Predictions of Single and Twin Jet Afterbodies

    NASA Technical Reports Server (NTRS)

    Carlson, John R.; Pao, S. Paul; Abdol-Hamid, Khaled S.; Jones, William T.

    1995-01-01

    The multiblock three-dimensional Navier-Stokes method PAB3D was utilized by the Component Integration Branch (formerly Propulsion Aerodynamics Branch) at the NASA-Langley Research Center in an international study sponsored by AGARD Working Group #17 for the assessment of the state-of-the-art of propulsion-airframe integration testing techniques and CFD prediction technologies. Three test geometries from ONERA involving fundamental flow physics and four geometries from NASA-LaRC involving realistic flow interactions of wing, body, tail, and jet plumes were chosen by the Working Group. An overview of results on four (1 ONERA and 3 LaRC) of the seven test cases is presented. External static pressures, integrated pressure drag and total drag were calculated for the Langley test cases and jet plume velocity profiles and turbulent viscous stresses were calculated for the ONERA test case. Only selected data from these calculations are presented in this paper. The complete data sets calculated by the participants will be presented in an AGARD summary report. Predicted surface static pressures compared favorably with experimental data for the Langley geometries. Predicted afterbody drag compared well with experiment. Predicted nozzle drag was typically low due to over-compression of the flow near the trailing edge. Total drag was typically high. Predicted jet plume quantities on the ONERA case compared generally well with data.

  8. Ion Thruster Discharge Performance Per Magnetic Field Topography

    NASA Technical Reports Server (NTRS)

    Wirz, Richard E.; Goebel, Dan

    2006-01-01

    DC-ION is a detailed computational model for predicting the plasma characteristics of rain-cusp ion thrusters. The advanced magnetic field meshing algorithm used by DC-ION allows precise treatment of the secondary electron flow. This capability allows self-consistent estimates of plasma potential that improves the overall consistency of the results of the discharge model described in Reference [refJPC05mod1]. Plasma potential estimates allow the model to predict the onset of plasma instabilities, and important shortcoming of the previous model for optimizing the design of discharge chambers. A magnetic field mesh simplifies the plasma flow calculations, for both the ions and the secondary electrons, and significantly reduces numerical diffusion that can occur with meshes not aligned with the magnetic field. Comparing the results of this model to experimental data shows that the behavior of the primary electrons, and the precise manner of their confinement, dictates the fundamental efficiency of ring-cusp. This correlation is evident in simulations of the conventionally sized NSTAR thruster (30 cm diameter) and the miniature MiXI thruster (3 cm diameter).

  9. Holland Type as a Moderator of Personality-Performance Predictions.

    ERIC Educational Resources Information Center

    Fritzsche, Barbara A.; McIntire, Sandra A.; Yost, Amy Powell

    2002-01-01

    Data from 559 undergraduates provided modest evidence that Holland's taxonomy of work environments moderated the relationship between personality and performance. The traits of agreeableness and conscientiousness were better predictors of performance in certain environments. The important relationship between personality and performance may be…

  10. The Prediction of Academic and Clinical Performance in Medical School

    ERIC Educational Resources Information Center

    Gough, Harrison G.; Hall, Wallace B.

    1975-01-01

    A study of medical student performance showed the clinical performance factor more or less unpredictable from aptitude and premedical academic achievement indices while the academic performance factor was forecast with acceptable accuracy by equations based on the Medical College Admissions Test and premedical grade point average. (JT)

  11. Prediction of Performance of a Cavitating Propeller in Oblique Inflow

    NASA Astrophysics Data System (ADS)

    Tian, Ye; Kinnas, Spyros A.

    2015-12-01

    A cavitating propeller subject to an oblique inflow in a cavitating tunnel is simulated using potential flow methods coupled with a Reynolds-averaged Navier-Stokes (RANS) solver. The propeller is mainly modelled using a panel method, while the inflow to the propeller is evaluated by coupling a Vortex-Lattice Method (VLM) with the RANS solver. The effects of the tunnel wall are incorporated into the calculated effective inflow to the propeller. The predicted propeller forces and cavity pattern are correlated with experiment. The fully wetted open water characteristics of the propeller predicted by the panel method are presented as well.

  12. Flow Field and Acoustic Predictions for Three-Stream Jets

    NASA Technical Reports Server (NTRS)

    Simmons, Shaun Patrick; Henderson, Brenda S.; Khavaran, Abbas

    2014-01-01

    Computational fluid dynamics was used to analyze a three-stream nozzle parametric design space. The study varied bypass-to-core area ratio, tertiary-to-core area ratio and jet operating conditions. The flowfield solutions from the Reynolds-Averaged Navier-Stokes (RANS) code Overflow 2.2e were used to pre-screen experimental models for a future test in the Aero-Acoustic Propulsion Laboratory (AAPL) at the NASA Glenn Research Center (GRC). Flowfield solutions were considered in conjunction with the jet-noise-prediction code JeNo to screen the design concepts. A two-stream versus three-stream computation based on equal mass flow rates showed a reduction in peak turbulent kinetic energy (TKE) for the three-stream jet relative to that for the two-stream jet which resulted in reduced acoustic emission. Additional three-stream solutions were analyzed for salient flowfield features expected to impact farfield noise. As tertiary power settings were increased there was a corresponding near nozzle increase in shear rate that resulted in an increase in high frequency noise and a reduction in peak TKE. As tertiary-to-core area ratio was increased the tertiary potential core elongated and the peak TKE was reduced. The most noticeable change occurred as secondary-to-core area ratio was increased thickening the secondary potential core, elongating the primary potential core and reducing peak TKE. As forward flight Mach number was increased the jet plume region decreased and reduced peak TKE.

  13. Prediction of directional reflectance of a corn field under stress

    NASA Technical Reports Server (NTRS)

    Suits, G. H.; Safir, G.; Ellingbroe, A. H.

    1972-01-01

    A vegetative canopy model concept is developed and used to calculate the directional spectral reflectance of a corn field under stress. The problem has been idealized by assuming that the canopy is represented in several layers of uniform but randomly distributed biological components; horizontal and vertical projection of leaves, for example, replaces the actual leaf. An accumulative horizontal projection leads to a quantitative horizontal leaf area index while accumulated vertical projections provide the vertical leaf index area for each layer. The spectral properties of the projections are obtained from the spectral properties of the biological components. These techniques together with soil reflectance data provide a physical description for the vegetative canopy and adequately interprete multispectral scanning data.

  14. Performance Modeling: Understanding the Present and Predicting theFuture

    SciTech Connect

    Bailey, David H.; Snavely, Allan

    2005-11-30

    We present an overview of current research in performance modeling, focusing on efforts underway in the Performance Evaluation Research Center (PERC). Using some new techniques, we are able to construct performance models that can be used to project the sustained performance of large-scale scientific programs on different systems, over a range of job and system sizes. Such models can be used by vendors in system designs, by computing centers in system acquisitions, and by application scientists to improve the performance of their codes.

  15. Predictive Effects of Online Peer Feedback Types on Performance Quality

    ERIC Educational Resources Information Center

    Yu, Fu-Yun; Wu, Chun-Ping

    2013-01-01

    This study examined the individual and combined predictive effects of two types of feedback (i.e., quantitative ratings and descriptive comments) in online peer-assessment learning systems on the quality of produced work. A total of 233 students participated in the study for six weeks. An online learning system that allows students to contribute…

  16. Prediction of performance of centrifugal pumps during starts under pressure

    NASA Technical Reports Server (NTRS)

    Rostafinski, W.

    1969-01-01

    Method which calculates start-up characteristics of centrifugal pumps reveals a capacity to predict pressure drop characteristics of pumps with vaned diffusers. Calculations are based on pump geometry, design-point flow, speed, and pressure rise, and the pump characteristic within range of approximately ten percent of the design-point flow.

  17. Predicting Student Performance in a Collaborative Learning Environment

    ERIC Educational Resources Information Center

    Olsen, Jennifer K.; Aleven, Vincent; Rummel, Nikol

    2015-01-01

    Student models for adaptive systems may not model collaborative learning optimally. Past research has either focused on modeling individual learning or for collaboration, has focused on group dynamics or group processes without predicting learning. In the current paper, we adjust the Additive Factors Model (AFM), a standard logistic regression…

  18. Personality Predicts Academic Performance: Exploring the Moderating Role of Gender

    ERIC Educational Resources Information Center

    Nguyen, N. T.; Allen, Larry C.; Fraccastoro, K.

    2005-01-01

    In this study, students' personality traits were investigated in relation to course grade in an undergraduate management course taught by the same professor and overall college grade point average (GPA). Conscientiousness positively and significantly predicted overall GPA over and beyond other personality traits of agreeableness, extroversion,…

  19. Using glint to perform geometric signature prediction and pose estimation

    NASA Astrophysics Data System (ADS)

    Paulson, Christopher; Zelnio, Edmund; Gorham, LeRoy; Wu, Dapeng

    2012-05-01

    We consider two problems in this paper. The rst problem is to construct a dictionary of elements without using synthetic data or a subset of the data collection; the second problem is to estimate the orientation of the vehicle, independent of the elevation angle. These problems are important to the SAR community because it will alleviate the cost to create the dictionary and reduce the number of elements in the dictionary needed for classication. In order to accomplish these tasks, we utilize the glint phenomenology, which is usually viewed as a hindrance in most algorithms but is valuable information in our research. One way to capitalize on the glint information is to predict the location of the int by using geometry of the single and double bounce phenomenology. After qualitative examination of the results, we were able to deduce that the geometry information was sucient for accurately predicting the location of the glint. Another way that we exploited the glint characteristics was by using it to extract the angle feature which we will use to do the pose estimation. Using this technique we were able to predict the cardinal heading of the vehicle within +/-2° with 96:6% having 0° error. Now this research will have an impact on the classication of SAR images because the geometric prediction will reduce the cost and time to develop and maintain the database for SAR ATR systems and the pose estimation will reduce the computational time and improve accuracy of vehicle classication.

  20. Prediction of Preclinical Operative Dentistry Performance in Two Instructional Methods.

    ERIC Educational Resources Information Center

    Boyd, Marcia; And Others

    1980-01-01

    The accuracy of manual and academic variables in predicting preclinical operative technique was evaluated. Correlations were low, but significant using the Perceptual Motor Ability Test (PMAT) of the Dental Admission Test. Students with low or average two-dimension scores on the PMAT benefited from an alternate teaching method. (JSR)

  1. Academic Performance, Popularity, and Depression Predict Adolescent Substance Use.

    ERIC Educational Resources Information Center

    Diego, Miguel A.; Field, Tiffany M.; Sanders, Christopher E.

    2003-01-01

    Eighty-nine high school seniors completed a questionnaire on their feelings and activities, including their use of drugs. Adolescents with a low grade point average, high popularity, and high depression were more likely to smoke cigarettes, drink alcohol, and smoke marijuana than were their peers. Cigarette and alcohol use predicted marijuana use,…

  2. Theta coupling between V4 and prefrontal cortex predicts visual short-term memory performance.

    PubMed

    Liebe, Stefanie; Hoerzer, Gregor M; Logothetis, Nikos K; Rainer, Gregor

    2012-03-01

    Short-term memory requires communication between multiple brain regions that collectively mediate the encoding and maintenance of sensory information. It has been suggested that oscillatory synchronization underlies intercortical communication. Yet, whether and how distant cortical areas cooperate during visual memory remains elusive. We examined neural interactions between visual area V4 and the lateral prefrontal cortex using simultaneous local field potential (LFP) recordings and single-unit activity (SUA) in monkeys performing a visual short-term memory task. During the memory period, we observed enhanced between-area phase synchronization in theta frequencies (3-9 Hz) of LFPs together with elevated phase locking of SUA to theta oscillations across regions. In addition, we found that the strength of intercortical locking was predictive of the animals' behavioral performance. This suggests that theta-band synchronization coordinates action potential communication between V4 and prefrontal cortex that may contribute to the maintenance of visual short-term memories. PMID:22286175

  3. Predicting Undergraduates' Persistence in Science, Technology, Engineering, and Math Fields

    NASA Astrophysics Data System (ADS)

    Koch, Amanda Joy

    A national shortage of workers in Science, Technology, Engineering, and Math (STEM) occupations has led to efforts to identify why people leave these fields. Lower persistence rates in STEM for females than for males have also led to examinations of features that cause females to leave STEM fields. The current study examines individual- and school-level features that influence undergraduate students' decisions to leave STEM majors, focusing on potential explanations for why females are more likely than males to leave. Persistence in STEM was examined in three samples: (a) persistence through the second year of college in a sample of high school seniors interested in STEM majors; (b) persistence through the fourth year of college in a sample of second year undergraduate STEM majors; and (c) persistence through the second, third, and fourth years of college in a sample of high school seniors interested in STEM majors. Differences between persistence in male-dominated and non-male-dominated STEM majors were also examined. In all samples, gender differences were found for most individual-level predictors, with males tending to score higher than females on measures such as SAT-Math, self-rated STEM ability, and high school extracurricular activities and awards in STEM. On the other hand, females earned better high school grades and had stronger relative non-STEM ability and achievement than males. Bivariate analyses indicated that those who persisted in STEM majors typically had higher scores than those who did not persist for SAT-Math, high school achievement, STEM course taking, undergraduate STEM grades, self-rated STEM ability, interest in STEM, extracurricular activities and awards in STEM, degree goals, and socioeconomic status. Multivariate analyses identified SAT-Math as one of the best predictors of persistence in high school samples, and undergraduate STEM GPA was one of the best predictors in the samples of second year undergraduates. In several samples, a

  4. Field measurement and model prediction of infiltration in treated wastewater irrigated clayey soil

    NASA Astrophysics Data System (ADS)

    Albalasmeh, Ammar; Gharaibeh, Mamoun; Ghezzehei, Teamrat

    2016-04-01

    Soil water infiltration is a critical process in designing irrigation systems, especially if traded wastewater (TWW) is being used. In this study, the ability of seven different infiltration models (Kostiakov, Modified Kostiakov, Philip, Horton, Holaton, SCS (US-Soil Conservation Service) and Huggins and Monke) were compared to estimate and assess those models' parameters, and to evaluate their prediction ability for TWW irrigated soils. The field measurements were conducted in TWW irrigated soils using a hood infiltrometer. Six comparison criteria including Mean error, Geometric mean error, Root mean square error, Coefficient of determination, F-Statistic and Akaike information criterion were used to determine the best performing model with the least number of fitting parameters. The research indicated that three-parameter models had the best description of the relationship between cumulative infiltration and time in the researched TWW irrigated soils.

  5. Predicted Effect of Geomagnetic Field on CALET Measurements

    NASA Astrophysics Data System (ADS)

    Rauch, Brian

    2014-03-01

    The CALorimetric Electron Telescope (CALET), comprised of the main calorimeter (CAL) and Gamma-ray Burst Monitor (CGBM) subsystem, is under construction for launch to the ISS. CAL consists of a scintillator Charge Detector (CHD), a 3 radiation length (X0) deep scintillating fiber Imaging Calorimeter (IMC), and a 27 X0 deep PWO Total Absorption Calorimeter (TASC). The primary objectives of CAL are to measure energy spectra of electrons from 1GeV to 20 TeV and nuclei through iron up to 1,000 TeV, and to detect gamma-rays above 10 GeV. Earth's geomagnetic field in the 51.6° inclination ISS orbit will affect the observed fluxes of charged particles. Rigidity cutoffs based on geomagnetic latitude and East-West angle will introduce structure to the charged particle energy spectra. They can also be exploited to facilitate the measurement of distinct positron and electron fluxes between ~3-20 GeV, and the relative abundances of the rare ultra-heavy (UH) nuclei (30 <= Z <= 40) by using the cutoffs to select nuclei near and above the CHD minimum ionization threshold so that they can be identified using the CHD and top IMC layers without requiring energy determination in the TASC. In 5-years CAL would collect ~2 × the UH statistics of TIGER. This research was supported by NASA at Washington University under Grant Number NNX11AE02G.

  6. Uncertainty in reservoir prediction: Example of shelf edge delta field

    SciTech Connect

    Durand, J.; Lecanu, H. ); Drullion, G. )

    1993-09-01

    Four wells have been drilled to appraise an oil field occurring in middle to upper Miocene sandstones of the eastern offshore Niger Delta. Because the reservoir thickness is below seismic resolution, the reservoir model is based on cores, high-resolution dipmeter tools, and conventional wireline logs. The model developed with the first three wells consists of dip-oriented elongate marine sandbodies occurring in an estuary mouth that were identified from cores and microresistivity response. They are interpreted to be located in the outer zone of the estuary dominated by tidal processes. Foreset dip azimuths measured from the Formation Micro Scanner suggest straight-crested bed forms and show that sand transport was dominantly to the west and northwest. This direction is interpreted to be the net export direction of the deltaic distributary system to the sea. The tidal mouth bars are stacked in seaward-stepping or landward-stepping patterns and are time transgressive. The reservoir was expected to progressively disappear westward. Facies revealed in cores from the fourth well drilled in a westward direction differ from the model proposed above. Vertically dipping beds are overlapped by normal-dipping tidal sandbars interbedded with gravity flow facies. Dipmeter study and facies characteristics suggest an olistolitic block progressively overlain by deltaic progradation due to the destabilization of the delta front in an extensional stress regime. On seismic profiles, a major listric normal fault associated with roll-over structure confirms this upgraded reservoir interpretation.

  7. Field Performance of a Genetically Engineered Strain of Pink Bollworm

    PubMed Central

    Simmons, Gregory S.; McKemey, Andrew R.; Morrison, Neil I.; O'Connell, Sinead; Tabashnik, Bruce E.; Claus, John; Fu, Guoliang; Tang, Guolei; Sledge, Mickey; Walker, Adam S.; Phillips, Caroline E.; Miller, Ernie D.; Rose, Robert I.; Staten, Robert T.; Donnelly, Christl A.; Alphey, Luke

    2011-01-01

    Pest insects harm crops, livestock and human health, either directly or by acting as vectors of disease. The Sterile Insect Technique (SIT) – mass-release of sterile insects to mate with, and thereby control, their wild counterparts – has been used successfully for decades to control several pest species, including pink bollworm, a lepidopteran pest of cotton. Although it has been suggested that genetic engineering of pest insects provides potential improvements, there is uncertainty regarding its impact on their field performance. Discrimination between released and wild moths caught in monitoring traps is essential for estimating wild population levels. To address concerns about the reliability of current marking methods, we developed a genetically engineered strain of pink bollworm with a heritable fluorescent marker, to improve discrimination of sterile from wild moths. Here, we report the results of field trials showing that this engineered strain performed well under field conditions. Our data show that attributes critical to SIT in the field – ability to find a mate and to initiate copulation, as well as dispersal and persistence in the release area – were comparable between the genetically engineered strain and a standard strain. To our knowledge, these represent the first open-field experiments with a genetically engineered insect. The results described here provide encouragement for the genetic control of insect pests. PMID:21931649

  8. ROPS performance during field upset and static testing.

    PubMed

    Harris, J R; McKenzie, E A; Etherton, J R; Cantis, D M; Ronaghi, M

    2010-01-01

    Agriculture remains one of the most hazardous occupations in the U.S. By conservative estimates, tractor overturns alone claim 120 lives annually. A rollover protective structure (ROPS) and a seatbelt are a highly effective engineering safety control that can prevent many of these fatalities and reduce the severity of injuries associated with tractor overturn. SAE J2194 is a consensus performance standard established for agricultural ROPS. According to this standard, satisfactory ROPS performance can be demonstrated through static testing, field upset testing, or impact testing. A previous modeling study suggested that static testing may underpredict the strain induced in a ROPS during afield upset. In the current study, field upset testing and laboratory static testing results were compared. Field upset testing included six rear and six side upset tests performed according to SAE J2194 guidelines. Additionally, static testing was performed on a ROPS of the same model. The results support findings from the modeling study. Near the lowest sections of the ROPS, the plastic strain resulting from rear upset testing exceeded the plastic strain from static testing for 18 of 24 data points. Conversely, the ROPS plastic strain from side upset testing was typically less than plastic strain from laboratory static testing. However, data indicate that the side upset test may not be very repeatable. This study suggests that the longitudinal loading energy criterion for static testing might not be a conservative predictor of rear upset ROPS response. PMID:20222267

  9. An analysis for high speed propeller-nacelle aerodynamic performance prediction. Volume 1: Theory and application

    NASA Technical Reports Server (NTRS)

    Egolf, T. Alan; Anderson, Olof L.; Edwards, David E.; Landgrebe, Anton J.

    1988-01-01

    A computer program, the Propeller Nacelle Aerodynamic Performance Prediction Analysis (PANPER), was developed for the prediction and analysis of the performance and airflow of propeller-nacelle configurations operating over a forward speed range inclusive of high speed flight typical of recent propfan designs. A propeller lifting line, wake program was combined with a compressible, viscous center body interaction program, originally developed for diffusers, to compute the propeller-nacelle flow field, blade loading distribution, propeller performance, and the nacelle forebody pressure and viscous drag distributions. The computer analysis is applicable to single and coaxial counterrotating propellers. The blade geometries can include spanwise variations in sweep, droop, taper, thickness, and airfoil section type. In the coaxial mode of operation the analysis can treat both equal and unequal blade number and rotational speeds on the propeller disks. The nacelle portion of the analysis can treat both free air and tunnel wall configurations including wall bleed. The analysis was applied to many different sets of flight conditions using selected aerodynamic modeling options. The influence of different propeller nacelle-tunnel wall configurations was studied. Comparisons with available test data for both single and coaxial propeller configurations are presented along with a discussion of the results.

  10. Wind field near complex terrain using numerical weather prediction model

    NASA Astrophysics Data System (ADS)

    Chim, Kin-Sang

    The PennState/NCAR MM5 model was modified to simulate an idealized flow pass through a 3D obstacle in the Micro- Alpha Scale domain. The obstacle used were the idealized Gaussian obstacle and the real topography of Lantau Island of Hong Kong. The Froude number under study is ranged from 0.22 to 1.5. Regime diagrams for both the idealized Gaussian obstacle and Lantau island were constructed. This work is divided into five parts. The first part is the problem definition and the literature review of the related publications. The second part briefly discuss as the PennState/NCAR MM5 model and a case study of long- range transport is included. The third part is devoted to the modification and the verification of the PennState/NCAR MM5 model on the Micro-Alpha Scale domain. The implementation of the Orlanski (1976) open boundary condition is included with the method of single sounding initialization of the model. Moreover, an upper dissipative layer, Klemp and Lilly (1978), is implemented on the model. The simulated result is verified by the Automatic Weather Station (AWS) data and the Wind Profiler data. Four different types of Planetary Boundary Layer (PBL) parameterization schemes have been investigated in order to find out the most suitable one for Micro-Alpha Scale domain in terms of both accuracy and efficiency. Bulk Aerodynamic type of PBL parameterization scheme is found to be the most suitable PBL parameterization scheme. Investigation of the free- slip lower boundary condition is performed and the simulated result is compared with that with friction. The fourth part is the use of the modified PennState/NCAR MM5 model for an idealized flow simulation. The idealized uniform flow used is nonhydrostatic and has constant Froude number. Sensitivity test is performed by varying the Froude number and the regime diagram is constructed. Moreover, nondimensional drag is found to be useful for regime identification. The model result is also compared with the analytic

  11. TankSIM: A Cryogenic Tank Performance Prediction Program

    NASA Technical Reports Server (NTRS)

    Bolshinskiy, L. G.; Hedayat, A.; Hastings, L. J.; Moder, J. P.; Schnell, A. R.; Sutherlin, S. G.

    2015-01-01

    Developed for predicting the behavior of cryogenic liquids inside propellant tanks under various environmental and operating conditions. Provides a multi-node analysis of pressurization, ullage venting and thermodynamic venting systems (TVS) pressure control using axial jet or spray bar TVS. Allows user to combine several different phases for predicting the liquid behavior for the entire flight mission timeline or part of it. Is a NASA in-house code, based on FORTRAN 90-95 and Intel Visual FORTRAN compiler, but can be used on any other platform (Unix-Linux, Compaq Visual FORTRAN, etc.). The last Version 7, released on December 2014, included detailed User's Manual. Includes the use of several RefPROP subroutines for calculating fluid properties.

  12. Work Ethic and Academic Performance: Predicting Citizenship and Counterproductive Behavior

    ERIC Educational Resources Information Center

    Meriac, John P.

    2012-01-01

    In this study, work ethic was examined as a predictor of academic performance, compared with standardized test scores and high school grade point average (GPA). Academic performance was expanded to include student organizational citizenship behavior (OCB) and student counterproductive behavior, comprised of cheating and disengagement, in addition…

  13. An Alternative Method to Predict Performance: Canonical Redundancy Analysis.

    ERIC Educational Resources Information Center

    Dawson-Saunders, Beth; Doolen, Deane R.

    1981-01-01

    The relationships between predictors of performance and subsequent measures of clinical performance in medical school were examined for two classes at Southern Illinois University of Medicine. Canonical redundancy analysis was used to evaluate the association between six academic and three biographical preselection characteristics and four…

  14. Architecture School Performance Predicted from ASAT, Intellective and Nonintellective Measures.

    ERIC Educational Resources Information Center

    Lunneborg, Clifford E.; Lunneborg, Patricia W.

    This study is part of a continuing search for measures of divergent thinking and for better predictors of performance in occupational areas depending on such ways of thinking. Traditional predictors of college performance, i.e., high school GPA and tests of verbal and quantitative aptitude have always worked much better estimating success in…

  15. Evaluation of initial collector field performance at the Langley Solar Building Test Facility

    NASA Technical Reports Server (NTRS)

    Boyle, R. J.; Knoll, R. H.; Jensen, R. N.

    1977-01-01

    The thermal performance of the solar collector field for the NASA Langley Solar Building Test Facility is given for October 1976 through January 1977. An 1180 square meter solar collector field with seven collector designs helped to provide hot water for the building heating system and absorption air conditioner. The collectors were arranged in 12 rows with nominally 51 collectors per row. Heat transfer rates for each row are calculated and recorded along with sensor, insolation, and weather data every 5 minutes using a mini-computer. The agreement between the experimental and predicted collector efficiencies was generally within five percentage points.

  16. Evaluation of initial collector field performance at the Langley Solar Building Test Facility

    NASA Technical Reports Server (NTRS)

    Boyle, R. J.; Jensen, R. N.; Knoll, R. H.

    1977-01-01

    The thermal performance of the solar collector field for the NASA Langley Solar Building Test Facility is given for October 1976 through January 1977. A 1,180 square meter solar collector field with seven collector designs helped to provide hot water for the building heating system and absorption air conditioner. The collectors were arranged in 12 rows with nominally 51 collectors per row. Heat transfer rates for each row were calculated and recorded along with sensor, insolation, and weather data every five minutes using a minicomputer. The agreement between the experimental and predicted collector efficiencies was generally within five percentage points.

  17. Prediction of Gas Injection Performance for Heterogeneous Reservoirs

    SciTech Connect

    Blunt, M.J.; Orr, F.M. Jr.

    2001-03-26

    This report was an integrated study of the physics and chemistry affecting gas injection, from the pore scale to the field scale, and involved theoretical analysis, laboratory experiments and numerical simulation. Specifically, advances were made on streamline-based simulation, analytical solutions to 1D compositional displacements, and modeling and experimental measures of three-phase flow.

  18. Ocean wind field measurement performance of the ERS-1 scatterometer

    NASA Technical Reports Server (NTRS)

    Hans, P.; Schuessler, H.

    1984-01-01

    The Active Microwave Instrumentation (AMI), which will be implemented on the ERS-1, is a 5.3 GHz multipurpose radar for land surface imaging, ocean wave spectrum measurement and wind observations over oceans. The imaging and wave measurements apply Synthetic Aperture Radar (SAR) techniques, while wind field detection is performed by the Scatterometer as part of the AMI. The Scatterometer system design was developed and optimized with the aid of a performance simulator. This paper, aimed at giving an overview, is presented about the: (1) ERS-1 Scatterometer system design; (2) Error budget; and the (3) Overall calibration concept.

  19. Performance of field measuring probes for SSC magnets

    SciTech Connect

    Thomas, R.; Ganetis, G.; Herrera, J.; Hogue, R.; Jain, A.; Louie, W.; Marone, A.; Wanderer, P.

    1993-12-31

    Several years of experience have been acquired on the operation of probes (``moles``) constructed for the measurement of the multipole components of the magnetic fields of SSC magnets. The field is measured by rotating coils contained in a 2.4-m long tube that is pulled through the aperture of the magnet by an external device-the transporter. In addition to the measuring coils, the tube contains motors for rotating the coil and a system for sensing local vertical using gravity sensors to provide an absolute reference for the field measurements. We describe the steps that must be taken in order to ensure accurate, repeatable measurements; the design changes that have been motivated by difficulties encountered (noise, vibration, variations in temperature); and other performance issues. The mechanical interface between the probe and the hewn tube of the magnet is also described.

  20. REVIEW OF MECHANISTIC UNDERSTANDING AND MODELING AND UNCERTAINTY ANALYSIS METHODS FOR PREDICTING CEMENTITIOUS BARRIER PERFORMANCE

    SciTech Connect

    Langton, C.; Kosson, D.

    2009-11-30

    Cementitious barriers for nuclear applications are one of the primary controls for preventing or limiting radionuclide release into the environment. At the present time, performance and risk assessments do not fully incorporate the effectiveness of engineered barriers because the processes that influence performance are coupled and complicated. Better understanding the behavior of cementitious barriers is necessary to evaluate and improve the design of materials and structures used for radioactive waste containment, life extension of current nuclear facilities, and design of future nuclear facilities, including those needed for nuclear fuel storage and processing, nuclear power production and waste management. The focus of the Cementitious Barriers Partnership (CBP) literature review is to document the current level of knowledge with respect to: (1) mechanisms and processes that directly influence the performance of cementitious materials (2) methodologies for modeling the performance of these mechanisms and processes and (3) approaches to addressing and quantifying uncertainties associated with performance predictions. This will serve as an important reference document for the professional community responsible for the design and performance assessment of cementitious materials in nuclear applications. This review also provides a multi-disciplinary foundation for identification, research, development and demonstration of improvements in conceptual understanding, measurements and performance modeling that would be lead to significant reductions in the uncertainties and improved confidence in the estimating the long-term performance of cementitious materials in nuclear applications. This report identifies: (1) technology gaps that may be filled by the CBP project and also (2) information and computational methods that are in currently being applied in related fields but have not yet been incorporated into performance assessments of cementitious barriers. The various

  1. Thermal Model Predictions of Advanced Stirling Radioisotope Generator Performance

    NASA Technical Reports Server (NTRS)

    Wang, Xiao-Yen J.; Fabanich, William Anthony; Schmitz, Paul C.

    2014-01-01

    This presentation describes the capabilities of three-dimensional thermal power model of advanced stirling radioisotope generator (ASRG). The performance of the ASRG is presented for different scenario, such as Venus flyby with or without the auxiliary cooling system.

  2. Prediction of noise field of a propfan at angle of attack

    NASA Technical Reports Server (NTRS)

    Envia, Edmane

    1991-01-01

    A method for predicting the noise field of a propfan operating at an angle of attack to the oncoming flow is presented. The method takes advantage of the high-blade-count of the advanced propeller designs to provide an accurate and efficient formula for predicting their noise field. The formula, which is written in terms of the Airy function and its derivative, provides a very attractive alternative to the use of numerical integration. A preliminary comparison shows rather favorable agreement between the predictions from the present method and the experimental data.

  3. Review of miscible flood performance, Intisar 'D' field, Socialist people's Libyan Arab Jamahiriya

    SciTech Connect

    DesBrisay, C.L.; El Ghussein, B.; Holst, P.H.; Misellati, A.

    1981-01-01

    The Intisar 'D' reservoir is a major oil field in the Sirte Basin of the Socialist People's Libyan Arab Jamahiriya. The field has been developed with bottom-water injection for pressure support and crestal high pressure miscible gas injection for enhanced oil recovery and gas conservation. This paper presents details of the reservoir performance and simulation study. Field performance results, have been history matched with a three-dimensional, 1,615-grid, two-component black oil simulator. The simulator prediction runs indicate that the final oil recovery efficiency for this dual displacement process will be approximately 70 percent. This high recovery is attributed to effective miscible displacement and gravity drainage together with efficient bottom-water displacement. 4 refs.

  4. Automated Performance Prediction of Message-Passing Parallel Programs

    NASA Technical Reports Server (NTRS)

    Block, Robert J.; Sarukkai, Sekhar; Mehra, Pankaj; Woodrow, Thomas S. (Technical Monitor)

    1995-01-01

    The increasing use of massively parallel supercomputers to solve large-scale scientific problems has generated a need for tools that can predict scalability trends of applications written for these machines. Much work has been done to create simple models that represent important characteristics of parallel programs, such as latency, network contention, and communication volume. But many of these methods still require substantial manual effort to represent an application in the model's format. The NIK toolkit described in this paper is the result of an on-going effort to automate the formation of analytic expressions of program execution time, with a minimum of programmer assistance. In this paper we demonstrate the feasibility of our approach, by extending previous work to detect and model communication patterns automatically, with and without overlapped computations. The predictions derived from these models agree, within reasonable limits, with execution times of programs measured on the Intel iPSC/860 and Paragon. Further, we demonstrate the use of MK in selecting optimal computational grain size and studying various scalability metrics.

  5. Prediction of performance of large synchronous machines with skewed stators

    NASA Astrophysics Data System (ADS)

    Troitskaia, Svetlana G.

    Large synchronous machines produce the majority of electric energy in Canada. To improve quality of the electric energy, manufacturers skew stators of these machines, Skewing causes axial shifting of magnetic fields, so that power losses in these machines differ from the losses in unskewed machines Numerical methods are incapable of analyzing a large skewed machine in a reasonable time. To evaluate losses, fast simulation tools have been needed to aid designers of skewed synchronous generators at a preliminary stage of design. This work is devoted to analytical modeling of harmonic magnetic fields, harmonic currents and high-frequency energy losses in large synchronous generators with skewed stators. A fast and accurate simulation tool has been developed on the basis of the model; it can be used for preliminary design of a skewed synchronous machine.

  6. Could the deep squat jump predict weightlifting performance?

    PubMed

    Vizcaya, Francisco J; Viana, Oscar; del Olmo, Miguel Fernandez; Acero, Rafael Martin

    2009-05-01

    This research was carried out with the aim of describing the deep squat jump (DSJ) and comparing it with the squat (SJ) and countermovement (CMJ) jumps, to introduce it as a strength testing tool in the monitoring and control of training in strength and power sports. Forty-eight male subjects (21 weightlifters, 12 triathletes, and 15 physical education students) performed 3 trials of DSJ, SJ, and CMJ with a 1-minute rest among them. For the weightlifters, snatch and clean and jerk results during the Spanish Championship 2004 and the 35th EU Championships 2007 were collected to study the relationship among vertical jumps and weightlifters' performance. A 1-way analysis of variance (ANOVA) showed significant differences between groups in the vertical jumps, with the highest jumps for the weightlifters and the lowest for the triathletes. An ANOVA for repeated measures (type of jump) showed better results for DSJ and CMJ than SJ in all groups. A linear regression analysis was performed to determine the association between weightlifting and vertical jump performances. Correlations among the weightlifting performance and the vertical jumps were also calculated and determined using Pearson r. Results have shown that both CMJ and DSJ are strongly correlated with weightlifting ability. Therefore, both measures can be useful for coaches as a strength testing tool in the monitoring and control of training in weightlifting. PMID:19387408

  7. Predicted performance of an integrated modular engine system

    NASA Technical Reports Server (NTRS)

    Binder, Michael; Felder, James L.

    1993-01-01

    Space vehicle propulsion systems are traditionally comprised of a cluster of discrete engines, each with its own set of turbopumps, valves, and a thrust chamber. The Integrated Modular Engine (IME) concept proposes a vehicle propulsion system comprised of multiple turbopumps, valves, and thrust chambers which are all interconnected. The IME concept has potential advantages in fault-tolerance, weight, and operational efficiency compared with the traditional clustered engine configuration. The purpose of this study is to examine the steady-state performance of an IME system with various components removed to simulate fault conditions. An IME configuration for a hydrogen/oxygen expander cycle propulsion system with four sets of turbopumps and eight thrust chambers has been modeled using the Rocket Engine Transient Simulator (ROCETS) program. The nominal steady-state performance is simulated, as well as turbopump thrust chamber and duct failures. The impact of component failures on system performance is discussed in the context of the system's fault tolerant capabilities.

  8. Results of model intercomparison : predicted vs. measured system performance.

    SciTech Connect

    Stein, Joshua S.

    2010-10-01

    This is a blind modeling study to illustrate the variability expected between PV performance model results. Objectives are to answer: (1) What is the modeling uncertainty; (2) Do certain models do better than others; (3) How can performance modeling be improved; and (4) What are the sources of uncertainty? Some preliminary conclusions are: (1) Large variation seen in model results; (2) Variation not entirely consistent across systems; (3) Uncertainty in assigning derates; (4) Discomfort when components are not included in database - Is there comfort when the components are in the database?; and (5) Residual analysis will help to uncover additional patterns in the models.

  9. Nonlinear Dynamic Inversion Baseline Control Law: Architecture and Performance Predictions

    NASA Technical Reports Server (NTRS)

    Miller, Christopher J.

    2011-01-01

    A model reference dynamic inversion control law has been developed to provide a baseline control law for research into adaptive elements and other advanced flight control law components. This controller has been implemented and tested in a hardware-in-the-loop simulation; the simulation results show excellent handling qualities throughout the limited flight envelope. A simple angular momentum formulation was chosen because it can be included in the stability proofs for many basic adaptive theories, such as model reference adaptive control. Many design choices and implementation details reflect the requirements placed on the system by the nonlinear flight environment and the desire to keep the system as basic as possible to simplify the addition of the adaptive elements. Those design choices are explained, along with their predicted impact on the handling qualities.

  10. Measurement, Prediction, and Training of Harmonic Audiation and Performance Skills.

    ERIC Educational Resources Information Center

    Humphreys, Jere T.

    1986-01-01

    Investigated music majors' ability to harmonize notated melodies and recorded melodies with chord symbols, and to perform harmonic accompaniments to recorded melodies. Results showed, among other findings, that subjects (n = 45) improved ability to harmonize simple melodic patterns and that melodic echo-playing ability was highly correlated with…

  11. Predicting Performance on a Firefighter's Ability Test from Fitness Parameters

    ERIC Educational Resources Information Center

    Michaelides, Marcos A.; Parpa, Koulla M.; Thompson, Jerald; Brown, Barry

    2008-01-01

    The purpose of this project was to identify the relationships between various fitness parameters such as upper body muscular endurance, upper and lower body strength, flexibility, body composition and performance on an ability test (AT) that included simulated firefighting tasks. A second intent was to create a regression model that would predict…

  12. Goal Orientations Predict Academic Performance beyond Intelligence and Personality

    ERIC Educational Resources Information Center

    Steinmayr, Ricarda; Bipp, Tanja; Spinath, Birgit

    2011-01-01

    Goal orientations are thought to be an important predictor of scholastic achievement. The present paper investigated the joint influence of goal orientations, intelligence, and personality on school performance in a sample of N=520 11th and 12th graders (303 female; mean age M=16.94 years). Intelligence, the Big Five factors of personality…

  13. Students' Metacomprehension Knowledge: Components That Predict Comprehension Performance

    ERIC Educational Resources Information Center

    Zabrucky, Karen M.; Moore, DeWayne; Agler, Lin-Miao Lin; Cummings, Andrea M.

    2015-01-01

    In the present study, we assessed students' metacomprehension knowledge and examined the components of knowledge most related to comprehension of expository texts. We used the Revised Metacomprehension Scale (RMCS) to investigate the relations between students' metacomprehension knowledge and comprehension performance. Students who evaluated and…

  14. Translation Ambiguity but Not Word Class Predicts Translation Performance

    ERIC Educational Resources Information Center

    Prior, Anat; Kroll, Judith F.; Macwhinney, Brian

    2013-01-01

    We investigated the influence of word class and translation ambiguity on cross-linguistic representation and processing. Bilingual speakers of English and Spanish performed translation production and translation recognition tasks on nouns and verbs in both languages. Words either had a single translation or more than one translation. Translation…

  15. Leadership Styles and Organizational Performance: A Predictive Analysis

    ERIC Educational Resources Information Center

    Kieu, Hung Q.

    2010-01-01

    Leadership is critically important because it affects the health of the organization. Research has found that leadership is one of the most significant contributors to organizational performance. Expanding and replicating previous research, and focusing on the specific telecommunications sector, this study used multiple correlation and regression…

  16. Competitive Learning Neural Network Ensemble Weighted by Predicted Performance

    ERIC Educational Resources Information Center

    Ye, Qiang

    2010-01-01

    Ensemble approaches have been shown to enhance classification by combining the outputs from a set of voting classifiers. Diversity in error patterns among base classifiers promotes ensemble performance. Multi-task learning is an important characteristic for Neural Network classifiers. Introducing a secondary output unit that receives different…

  17. The Validity of Physical Aggression in Predicting Adolescent Academic Performance

    ERIC Educational Resources Information Center

    Loveland, James M.; Lounsbury, John W.; Welsh, Deborah; Buboltz, Walter C.

    2007-01-01

    Background: Aggression has a long history in academic research as both a criterion and a predictor variable and it is well documented that aggression is related to a variety of poor academic outcomes such as: lowered academic performance, absenteeism and lower graduation rates. However, recent research has implicated physical aggression as being…

  18. Resilience Does Not Predict Academic Performance in Gross Anatomy

    ERIC Educational Resources Information Center

    Elizondo-Omana, Rodrigo Enrique; Garcia-Rodriguez, Maria de los Angeles; Hinojosa-Amaya, Jose Miguel; Villarreal-Silva, Eliud Enrique; Avilan, Rosa Ivette Guzman; Cruz, Juan Jose Bazaldua; Guzman-Lopez, Santos

    2010-01-01

    Few studies have evaluated resilience in an academic environment as it relates to academic success or failure. This work sought to assess resilience in regular and remedial students of gross anatomy during the first and second semesters of medical school and to correlate this personal trait with academic performance. Two groups of students were…

  19. Predicting Postfeedback Performance from Students' Confidence in Their Responses.

    ERIC Educational Resources Information Center

    Bender, Timothy A.

    The model of feedback processing proposed by R. W. Kulhavy and W. A. Stock (1989) was studied in a traditional classroom setting in which methods of assessing students' response confidence as predictors of postfeedback performance were also examined. The relationship between confidence ratings at the time of the test and confidence assessed prior…

  20. Predicting Supervisor, Peer, and Self Ratings of Intern Performance

    ERIC Educational Resources Information Center

    Kegel-Flom, Penelope

    1975-01-01

    Relationships between the ratings of interns by their supervisors, their peers, and the interns themselves on four dimensions are compared and analyzed in relationship to earlier measures of aptitude, achievement, and personality. Findings reported show supervisor ratings to be highest and admission variables to be unrelated to intern performance.…

  1. Inhibitory Control Predicts Language Switching Performance in Trilingual Speech Production

    ERIC Educational Resources Information Center

    Linck, Jared A.; Schwieter, John W.; Sunderman, Gretchen

    2012-01-01

    This study investigated the role of domain-general inhibitory control in trilingual speech production. Taking an individual differences approach, we examined the relationship between performance on a non-linguistic measure of inhibitory control (the Simon task) and a multilingual language switching task for a group of fifty-six native English (L1)…

  2. HIGH RESOLUTION PREDICTION OF GAS INJECTION PROCESS PERFORMANCE FOR HETEROGENEOUS RESERVOIRS

    SciTech Connect

    Franklin M. Orr, Jr.

    2001-03-31

    This report outlines progress in the second 3 months of the first year of the DOE project ''High Resolution Prediction of Gas Injection Process Performance for Heterogeneous Reservoirs.'' The development of an automatic technique for analytical solution of one-dimensional gas flow problems with volume change on mixing is described. The aim of this work is to develop a set of ultra-fast compositional simulation tools that can be used to make field-scale predictions of the performance of gas injection processes. To achieve the necessary accuracy, these tools must satisfy the fundamental physics and chemistry of the displacement from the pore to the reservoir scales. Thus this project focuses on four main research areas: (1) determination of the most appropriate methods of mapping multicomponent solutions to streamlines and streamtubes in 3D; (2) development of techniques for automatic generation of analytical solutions for one-dimensional flow along a streamline; (3) experimental investigations to improve the representation of physical mechanisms that govern displacement efficiency along a streamline; and (4) theoretical and experimental investigations to establish the limitations of the streamline/streamtube approach. In this report they briefly review the status of the research effort in each area. They then give a more in depth discussion of their development of techniques for analytic solutions along a streamline including volume change on mixing for arbitrary numbers of components.

  3. Mean Platelet Volume (MPV) Predicts Middle Distance Running Performance

    PubMed Central

    Lippi, Giuseppe; Salvagno, Gian Luca; Danese, Elisa; Skafidas, Spyros; Tarperi, Cantor; Guidi, Gian Cesare; Schena, Federico

    2014-01-01

    Background Running economy and performance in middle distance running depend on several physiological factors, which include anthropometric variables, functional characteristics, training volume and intensity. Since little information is available about hematological predictors of middle distance running time, we investigated whether some hematological parameters may be associated with middle distance running performance in a large sample of recreational runners. Methods The study population consisted in 43 amateur runners (15 females, 28 males; median age 47 years), who successfully concluded a 21.1 km half-marathon at 75–85% of their maximal aerobic power (VO2max). Whole blood was collected 10 min before the run started and immediately thereafter, and hematological testing was completed within 2 hours after sample collection. Results The values of lymphocytes and eosinophils exhibited a significant decrease compared to pre-run values, whereas those of mean corpuscular volume (MCV), platelets, mean platelet volume (MPV), white blood cells (WBCs), neutrophils and monocytes were significantly increased after the run. In univariate analysis, significant associations with running time were found for pre-run values of hematocrit, hemoglobin, mean corpuscular hemoglobin (MCH), red blood cell distribution width (RDW), MPV, reticulocyte hemoglobin concentration (RetCHR), and post-run values of MCH, RDW, MPV, monocytes and RetCHR. In multivariate analysis, in which running time was entered as dependent variable whereas age, sex, blood lactate, body mass index, VO2max, mean training regimen and the hematological parameters significantly associated with running performance in univariate analysis were entered as independent variables, only MPV values before and after the trial remained significantly associated with running time. After adjustment for platelet count, the MPV value before the run (p = 0.042), but not thereafter (p = 0.247), remained significantly

  4. Transport of simazine in unsaturated sandy soil and predictions of its leaching under hypothetical field conditions.

    PubMed

    Suárez, Francisco; Bachmann, Jaime; Muñoz, José F; Ortiz, Cristian; Tyler, Scott W; Alister, Claudio; Kogan, Marcelo

    2007-12-01

    The potential contamination of groundwater by herbicides is often controlled by processes in the vadose zone, through which herbicides travel before entering groundwater. In the vadose zone, both physical and chemical processes affect the fate and transport of herbicides, therefore it is important to represent these processes by mathematical models to predict contaminant movement. To simulate the movement of simazine, a herbicide commonly used in Chilean vineyards, batch and miscible displacement column experiments were performed on a disturbed sandy soil to quantify the primary parameters and processes of simazine transport. Chloride (Cl(-)) was used as a non-reactive tracer, and simazine as the reactive tracer. The Hydrus-1D model was used to estimate the parameters by inversion from the breakthrough curves of the columns and to evaluate the potential groundwater contamination in a sandy soil from the Casablanca Valley, Chile. The two-site, chemical non-equilibrium model was observed to best represent the experimental results of the miscible displacement experiments in laboratory soil columns. Predictions of transport under hypothetical field conditions using the same soil from the column experiments were made for 40 years by applying herbicide during the first 20 years, and then halting the application and considering different rates of groundwater recharge. For recharge rates smaller than 84 mm year(-1), the predicted concentration of simazine at a depth of 1 m is below the U.S. EPA's maximum contaminant levels (4 microg L(-1)). After eight years of application at a groundwater recharge rate of 180 mm year(-1) (approximately 50% of the annual rainfall), simazine was found to reach the groundwater (located at 1 m depth) at a higher concentration (more than 40 microg L(-1)) than the existing guidelines in the USA and Europe. PMID:17604874

  5. Moffett Field Funnel and Gate TCE Treatment System: Interpretation of Field Performance using Reactive Transport Modeling

    SciTech Connect

    Yabusaki, Steven B.; Cantrell, Kirk J.; Sass, B. M.

    2001-06-30

    A multicomponent reactive transport simulator was used to understand the behavior of chemical components, including TCE and cis-1,2-DCE, in groundwater transported through the pilot-scale funnel and gate chemical treatment system at Moffett Field, California. Field observations indicated that zero-valent iron emplaced in the gate to effect the destruction of chlorinated hydrocarbons also resulted in increases in pH and hydrocarbons, as well as decreases in EH, alkalinity, dissolved O2 and CO2, and major ions (i.e., Ca, Mg, Cl, sulfate, nitrate). Of concern are chemical transformations that may reduce the effectiveness or longevity of the iron cell and/or create secondary contaminants. A coupled model of transport and reaction processes was developed to account for mobile and immobile components undergoing equilibrium and kinetic reactions including TCE degradation, parallel iron dissolution reactions, precipitation of secondary minerals, and complexation reactions. The model reproduced solution chemistry observed in the iron cell using reaction parameters from the literature and laboratory studies. Mineral precipitation in the iron zone, which is critical to correctly predicting the aqueous concentrations, was predicted to account for up to 3 percent additional mineral volume annually. Interplay between rates of transport and rates of reaction in the field was key to understanding system behavior.

  6. Using the 2 x 2 Framework of Achievement Goals to Predict Achievement Emotions and Academic Performance

    ERIC Educational Resources Information Center

    Putwain, David W.; Sander, Paul; Larkin, Derek

    2013-01-01

    Previous work has established how achievement emotions are related to the trichotomous model of achievement goals, and how they predict academic performance. In our study we examine relations using an additional, mastery-avoidance goal, and whether outcome-focused emotions are predicted by mastery as well as performance goals. Results showed that…

  7. A Bayesian Performance Prediction Model for Mathematics Education: A Prototypical Approach for Effective Group Composition

    ERIC Educational Resources Information Center

    Bekele, Rahel; McPherson, Maggie

    2011-01-01

    This research work presents a Bayesian Performance Prediction Model that was created in order to determine the strength of personality traits in predicting the level of mathematics performance of high school students in Addis Ababa. It is an automated tool that can be used to collect information from students for the purpose of effective group…

  8. Improved Fuzzy Modelling to Predict the Academic Performance of Distance Education Students

    ERIC Educational Resources Information Center

    Yildiz, Osman; Bal, Abdullah; Gulsecen, Sevinc

    2013-01-01

    It is essential to predict distance education students' year-end academic performance early during the course of the semester and to take precautions using such prediction-based information. This will, in particular, help enhance their academic performance and, therefore, improve the overall educational quality. The present study was on the…

  9. THE RELATIONSHIP OF CERTAIN PREDICTION AND SELF-EVALUATION DISCREPANCIES TO ART PERFORMANCE AND ART JUDGMENT.

    ERIC Educational Resources Information Center

    HARVEY, THEODORE E.

    NINTH-GRADE STUDENTS WERE SELECTED AS A SAMPLE TO STUDY THE RELATIONSHIP OF CERTAIN PREDICTION AND SELF-EVALUATION DISCREPANCIES TO ART PERFORMANCE AND ART JUDGMENT. STUDENTS WERE REQUIRED TO DEVELOP AN OIL CRAYON DRAWING, RESULTING FROM AN IMAGINARY SENTENCE SPOKEN TO AND SEEN BY ALL PARTICIPANTS. PREDICTIONS OF PERFORMANCE WERE ASKED PRIOR TO…

  10. Grayscale performance enhancement for time-multiplexing light field rendering.

    PubMed

    Su, Chen; Zhong, Qing; Peng, Yifan; Xu, Liang; Wang, Rui; Li, Haifeng; Liu, Xu

    2015-12-14

    One of the common approaches to compensate for the grayscale performance limitation in time-multiplexing light field displays is to employ a halftone technique. We propose an ordered-dithering halftone algorithm based on a 3-dimension super-mask to increase the gray levels of the time-multiplexing light field display. Our method makes full use of the overlapping perceived pixels which are caused by the time-multiplexing design, such that effectively trading-off the spatial resolution and color performance. A real-time rendering time-multiplexing display prototype is built to validate the proposed halftone algorithm. We conducted a user study to evaluate the quality of display scenes dithered by different super-mask configuration, which showed the consistency with the parameters we pre-calculated. The 3D ordered-dithering algorithm is able to present better visual perception than the conventional halftone algorithms with respect to grayscale representation, and flexible to be applied in different time-multiplexing light field display systems. PMID:26699051

  11. Evaluation of Turbulence-Model Performance as Applied to Jet-Noise Prediction

    NASA Technical Reports Server (NTRS)

    Woodruff, S. L.; Seiner, J. M.; Hussaini, M. Y.; Erlebacher, G.

    1998-01-01

    The accurate prediction of jet noise is possible only if the jet flow field can be predicted accurately. Predictions for the mean velocity and turbulence quantities in the jet flowfield are typically the product of a Reynolds-averaged Navier-Stokes solver coupled with a turbulence model. To evaluate the effectiveness of solvers and turbulence models in predicting those quantities most important to jet noise prediction, two CFD codes and several turbulence models were applied to a jet configuration over a range of jet temperatures for which experimental data is available.

  12. Electric field-treated MEAs for improved fuel cell performance

    NASA Astrophysics Data System (ADS)

    Wang, Zhi-Tao; Wang, Yu-Xin; Xu, Li; Gao, Qi-Jun; Wei, Guo-Qiang; Lu, Jun

    In this paper, electric field assisted fabrication of membrane electrode assemblies (MEAs) for fuel cells is proposed, with the aim of improving the electronic and ionic connections in the catalyst layers and increasing the efficiency of catalyst utilization. Anodic and cathodic electrodes have been prepared by the perpendicular application of a low-frequency ac electric field to the catalyst ink spread on the surface of a gas diffusion layer (GDL) while the ink is drying. The thus prepared electrodes were hot-pressed onto a Nafion membrane to form the MEAs. Direct methanol fuel cells (DMFCs) with the electric field-treated MEAs (E-MEA) showed a substantial improvement in performance as compared with common MEAs (C-MEA) without electric field treatment. Under the same operating conditions, the maximum power density of a DMFC was increased from 42.3 to 60.0 mW cm -2 when a C-MEA was replaced by an E-MEA treated with a 5000 V cm -1 and 0.1 Hz ac electric field. Electrochemical impedance spectroscopy (EIS) measurements have shown that the through-plane ohmic resistances in the E-MEAs are lower than that in the C-MEA, while both the electronic and ionic resistances of the catalyst layer in the in-plane direction are higher for the E-MEAs, suggesting the formation of an oriented structure in the catalyst layers under the electric field treatment. EIS measurements have also shown that both the total reaction resistance and the anode reaction resistance in the E-MEAs are lower than in the C-MEA. Based on cyclic voltammetry (CV) data, it has been shown that Pt utilization in the cathode reaches a maximum of 62% for the E-MEA, as opposed to 37% for the C-MEA.

  13. Prediction of STN-DBS Electrode Implantation Track in Parkinson's Disease by Using Local Field Potentials.

    PubMed

    Telkes, Ilknur; Jimenez-Shahed, Joohi; Viswanathan, Ashwin; Abosch, Aviva; Ince, Nuri F

    2016-01-01

    Optimal electrophysiological placement of the DBS electrode may lead to better long term clinical outcomes. Inter-subject anatomical variability and limitations in stereotaxic neuroimaging increase the complexity of physiological mapping performed in the operating room. Microelectrode single unit neuronal recording remains the most common intraoperative mapping technique, but requires significant expertise and is fraught by potential technical difficulties including robust measurement of the signal. In contrast, local field potentials (LFPs), owing to their oscillatory and robust nature and being more correlated with the disease symptoms, can overcome these technical issues. Therefore, we hypothesized that multiple spectral features extracted from microelectrode-recorded LFPs could be used to automate the identification of the optimal track and the STN localization. In this regard, we recorded LFPs from microelectrodes in three tracks from 22 patients during DBS electrode implantation surgery at different depths and aimed to predict the track selected by the neurosurgeon based on the interpretation of single unit recordings. A least mean square (LMS) algorithm was used to de-correlate LFPs in each track, in order to remove common activity between channels and increase their spatial specificity. Subband power in the beta band (11-32 Hz) and high frequency range (200-450 Hz) were extracted from the de-correlated LFP data and used as features. A linear discriminant analysis (LDA) method was applied both for the localization of the dorsal border of STN and the prediction of the optimal track. By fusing the information from these low and high frequency bands, the dorsal border of STN was localized with a root mean square (RMS) error of 1.22 mm. The prediction accuracy for the optimal track was 80%. Individual beta band (11-32 Hz) and the range of high frequency oscillations (200-450 Hz) provided prediction accuracies of 72 and 68% respectively. The best prediction

  14. Prediction of STN-DBS Electrode Implantation Track in Parkinson's Disease by Using Local Field Potentials

    PubMed Central

    Telkes, Ilknur; Jimenez-Shahed, Joohi; Viswanathan, Ashwin; Abosch, Aviva; Ince, Nuri F.

    2016-01-01

    Optimal electrophysiological placement of the DBS electrode may lead to better long term clinical outcomes. Inter-subject anatomical variability and limitations in stereotaxic neuroimaging increase the complexity of physiological mapping performed in the operating room. Microelectrode single unit neuronal recording remains the most common intraoperative mapping technique, but requires significant expertise and is fraught by potential technical difficulties including robust measurement of the signal. In contrast, local field potentials (LFPs), owing to their oscillatory and robust nature and being more correlated with the disease symptoms, can overcome these technical issues. Therefore, we hypothesized that multiple spectral features extracted from microelectrode-recorded LFPs could be used to automate the identification of the optimal track and the STN localization. In this regard, we recorded LFPs from microelectrodes in three tracks from 22 patients during DBS electrode implantation surgery at different depths and aimed to predict the track selected by the neurosurgeon based on the interpretation of single unit recordings. A least mean square (LMS) algorithm was used to de-correlate LFPs in each track, in order to remove common activity between channels and increase their spatial specificity. Subband power in the beta band (11–32 Hz) and high frequency range (200–450 Hz) were extracted from the de-correlated LFP data and used as features. A linear discriminant analysis (LDA) method was applied both for the localization of the dorsal border of STN and the prediction of the optimal track. By fusing the information from these low and high frequency bands, the dorsal border of STN was localized with a root mean square (RMS) error of 1.22 mm. The prediction accuracy for the optimal track was 80%. Individual beta band (11–32 Hz) and the range of high frequency oscillations (200–450 Hz) provided prediction accuracies of 72 and 68% respectively. The best

  15. Ski jump takeoff performance predictions for a mixed-flow, remote-lift STOVL aircraft

    NASA Technical Reports Server (NTRS)

    Birckelbaw, Lourdes G.

    1992-01-01

    A ski jump model was developed to predict ski jump takeoff performance for a short takeoff and vertical landing (STOVL) aircraft. The objective was to verify the model with results from a piloted simulation of a mixed flow, remote lift STOVL aircraft. The prediction model is discussed. The predicted results are compared with the piloted simulation results. The ski jump model can be utilized for basic research of other thrust vectoring STOVL aircraft performing a ski jump takeoff.

  16. Performance Predictions of Supersonic Intakes with Isentropic-Compression Forebody

    NASA Astrophysics Data System (ADS)

    Nakashima, K.; Saito, Tsutomu

    Intake is an important component of next generation air-breathing engines such as Ram/Scram jet engines, as well as conventional jet-propulsion systems. The supersonic intake decelerates compresses the air inflow by shocks or compression waves to appropriate flow conditions for a specific engine system. The performance of supersonic intakes is evaluated mainly by the mass flow rate and the total pressure recovery rate.

  17. Power and Performance Management in Nonlinear Virtualized Computing Systems via Predictive Control.

    PubMed

    Wen, Chengjian; Mu, Yifen

    2015-01-01

    The problem of power and performance management captures growing research interest in both academic and industrial field. Virtulization, as an advanced technology to conserve energy, has become basic architecture for most data centers. Accordingly, more sophisticated and finer control are desired in virtualized computing systems, where multiple types of control actions exist as well as time delay effect, which make it complicated to formulate and solve the problem. Furthermore, because of improvement on chips and reduction of idle power, power consumption in modern machines shows significant nonlinearity, making linear power models(which is commonly adopted in previous work) no longer suitable. To deal with this, we build a discrete system state model, in which all control actions and time delay effect are included by state transition and performance and power can be defined on each state. Then, we design the predictive controller, via which the quadratic cost function integrating performance and power can be dynamically optimized. Experiment results show the effectiveness of the controller. By choosing a moderate weight, a good balance can be achieved between performance and power: 99.76% requirements can be dealt with and power consumption can be saved by 33% comparing to the case with open loop controller. PMID:26225769

  18. Power and Performance Management in Nonlinear Virtualized Computing Systems via Predictive Control

    PubMed Central

    Wen, Chengjian; Mu, Yifen

    2015-01-01

    The problem of power and performance management captures growing research interest in both academic and industrial field. Virtulization, as an advanced technology to conserve energy, has become basic architecture for most data centers. Accordingly, more sophisticated and finer control are desired in virtualized computing systems, where multiple types of control actions exist as well as time delay effect, which make it complicated to formulate and solve the problem. Furthermore, because of improvement on chips and reduction of idle power, power consumption in modern machines shows significant nonlinearity, making linear power models(which is commonly adopted in previous work) no longer suitable. To deal with this, we build a discrete system state model, in which all control actions and time delay effect are included by state transition and performance and power can be defined on each state. Then, we design the predictive controller, via which the quadratic cost function integrating performance and power can be dynamically optimized. Experiment results show the effectiveness of the controller. By choosing a moderate weight, a good balance can be achieved between performance and power: 99.76% requirements can be dealt with and power consumption can be saved by 33% comparing to the case with open loop controller. PMID:26225769

  19. Soil Moisture Performance Prediction for the NPOESS Microwave Imager/Sounder (MIS)

    NASA Astrophysics Data System (ADS)

    Li, L.; McWilliams, G.

    2009-12-01

    Soil moisture is a key environmental variable in the global water, energy and carbon cycles and in environmental assessment and prediction. It greatly affects a broad range of scientific and operational applications in hydrology, climate studies and agriculture. Soil moisture is also a desired input parameter to Numerical Weather Prediction (NWP) models since it controls the land-atmosphere interaction, such as dust emission and heating/moistening of the lower atmosphere. It is also a critical battlespace environment variable affecting military operations. The soil moisture content is critically related to trafficability as well as being a vital determinant of thermal and electromagnetic signatures that are vital to the operational ground mission in C4ISR (command, control, communications, computers, intelligence, surveillance, and reconnaissance). The National Polar-orbiting Operational Environmental Satellite System’s (NPOESS) Microwave Imager/Sounder (MIS) instrument is in development, with soil moisture sensing depth as one of the two Key Performance Parameters (KPPs). The other one is ocean surface wind speed precision. Based on the current design, the MIS sensor shares many channel configurations similar to the WindSat instrument, which provides an opportunity to predict MIS soil moisture performance using WindSat data. The WindSat land surface algorithm is a physically-based algorithm used to retrieve simultaneously the soil moisture, land surface temperature and vegetation water content for a range of surface types except for snow, frozen, rainy and flood surfaces. The algorithm has been rigorously validated against global in-situ data and has demonstrated great science potential in study of soil moisture response to precipitation, ITCZ (Intertropical Convergence Zone) propagation, drought detection, and heat wave evolution. The evaluation results suggest that the WindSat data products meet IORD II threshold soil moisture requirements. To approximate MIS

  20. Effectiveness of Genomic Prediction of Maize Hybrid Performance in Different Breeding Populations and Environments

    PubMed Central

    Windhausen, Vanessa S.; Atlin, Gary N.; Hickey, John M.; Crossa, Jose; Jannink, Jean-Luc; Sorrells, Mark E.; Raman, Babu; Cairns, Jill E.; Tarekegne, Amsal; Semagn, Kassa; Beyene, Yoseph; Grudloyma, Pichet; Technow, Frank; Riedelsheimer, Christian; Melchinger, Albrecht E.

    2012-01-01

    Genomic prediction is expected to considerably increase genetic gains by increasing selection intensity and accelerating the breeding cycle. In this study, marker effects estimated in 255 diverse maize (Zea mays L.) hybrids were used to predict grain yield, anthesis date, and anthesis-silking interval within the diversity panel and testcross progenies of 30 F2-derived lines from each of five populations. Although up to 25% of the genetic variance could be explained by cross validation within the diversity panel, the prediction of testcross performance of F2-derived lines using marker effects estimated in the diversity panel was on average zero. Hybrids in the diversity panel could be grouped into eight breeding populations differing in mean performance. When performance was predicted separately for each breeding population on the basis of marker effects estimated in the other populations, predictive ability was low (i.e., 0.12 for grain yield). These results suggest that prediction resulted mostly from differences in mean performance of the breeding populations and less from the relationship between the training and validation sets or linkage disequilibrium with causal variants underlying the predicted traits. Potential uses for genomic prediction in maize hybrid breeding are discussed emphasizing the need of (1) a clear definition of the breeding scenario in which genomic prediction should be applied (i.e., prediction among or within populations), (2) a detailed analysis of the population structure before performing cross validation, and (3) larger training sets with strong genetic relationship to the validation set. PMID:23173094

  1. Research of performance prediction to energy on hydraulic turbine

    NASA Astrophysics Data System (ADS)

    Quan, H.; Li, R. N.; Li, Q. F.; Han, W.; Su, Q. M.

    2012-11-01

    Refer to the low specific speed Francis turbine blade design principle and double-suction pump structure. Then, design a horizontal double-channel hydraulic turbine Francis. Through adding different guide vane airfoil and and no guide vane airfoil on the hydraulic conductivity components to predict hydraulic turbine energy and using Fluent software to numerical simulation that the operating conditions and point. The results show that the blade pressure surface and suction surface pressure is low when the hydraulic turbine installation is added standard positive curvature of the guide vane and modified positive curvature of guide vane. Therefore, the efficiency of energy recovery is low. However, the pressure of negative curvature guide vane and symmetric guide vane added on hydraulic turbine installations is larger than that of the former ones, and it is conducive to working of runner. With the decreasing of guide vane opening, increasing of inlet angle, flow state gets significantly worse. Then, others obvious phenomena are that the reflux and horizontal flow appeared in blade pressure surface. At the same time, the vortex was formed in Leaf Road, leading to the loss of energy. Through analyzing the distribution of pressure, velocity, flow lines of over-current flow in the the back hydraulic conductivity components in above programs we can known that the hydraulic turbine installation added guide vane is more reasonable than without guide vanes, it is conducive to improve efficiency of energy conversion.

  2. Revised MITG design, fabrication procedure, and performance predictions

    SciTech Connect

    Schock, A.

    1983-01-01

    The design, analysis, and key features of the Modular Isotopic Thermoelectric Generator (MITG) were described in a 1981 IECEC paper; and the design, fabrication, testing, and post-test analysis of test assemblies simulating prototypical MITG modules were described in preceding papers in these proceedings. These analyses succeeded in identifying and explaining the principal causes of thermal-stress problems encountered in the tests, and in confirming the effectiveness of design changes for alleviating them. The present paper presents additional design improvements for solving these and other problems, and describes new thermoelectric material properties generated by independent laboratories over the past two years. Based on these changes and on a revised fabrication procedure, it presents a reoptimization of the MITG design and computes the power-to-weight ratio for the revised design. That ratio is appreciably lower than the 1981 prediction, primarily because of changes in material properties; but it is still much higher than the specific power of current-generation RTGs.

  3. Which psychosocial factors best predict cognitive performance in older adults?

    PubMed

    Zahodne, Laura B; Nowinski, Cindy J; Gershon, Richard C; Manly, Jennifer J

    2014-05-01

    Negative affect (e.g., depression) is associated with accelerated age-related cognitive decline and heightened dementia risk. Fewer studies examine positive psychosocial factors (e.g., emotional support, self-efficacy) in cognitive aging. Preliminary reports suggest that these variables predict slower cognitive decline independent of negative affect. No reports have examined these factors in a single model to determine which best relate to cognition. Data from 482 individuals 55 and older came from the normative sample for the NIH Toolbox for the Assessment of Neurological and Behavioral Function. Negative and positive psychosocial factors, executive functioning, working memory, processing speed, and episodic memory were measured with the NIH Toolbox Emotion and Cognition modules. Confirmatory factor analysis and structural equation modeling characterized independent relations between psychosocial factors and cognition. Psychosocial variables loaded onto negative and positive factors. Independent of education, negative affect and health status, greater emotional support was associated with better task-switching and processing speed. Greater self-efficacy was associated with better working memory. Negative affect was not independently associated with any cognitive variables. Findings support the conceptual distinctness of negative and positive psychosocial factors in older adults. Emotional support and self-efficacy may be more closely tied to cognition than other psychosocial variables. PMID:24685143

  4. Morphology predicts suction feeding performance in centrarchid fishes.

    PubMed

    Carroll, Andrew M; Wainwright, Peter C; Huskey, Stephen H; Collar, David C; Turingan, Ralph G

    2004-10-01

    Suction feeding fish differ in their capacity to generate subambient pressure while feeding, and these differences appear to relate to morphological variation. We developed a morphological model of force transmission in the fish head and parameterized it with measurements from individual fish. The model was applied to 45 individuals from five species of centrarchid fishes: Lepomis macrochirus, Lepomis punctatus, Lepomis microlophus, Micropterus salmoides and Pomoxis nigromaculatus. Measurements of epaxial cross-sectional area, epaxial moment arm, buccal area and buccal area moment arm were combined to estimate pressure generation capacity for individual fish. This estimation was correlated with pressure measured in fish feeding on elusive prey to test the model's ability to predict pressure generation from morphology. The model explained differences in pressure generation found among individuals (P<0.001, r2=0.71) and produced a realistic estimate of normalized muscle stress during suction feeding (68.5+/-6.7 kPa). Fish with smaller mouths, larger epaxial cross-sectional area and longer epaxial moments, such as L. macrochirus (bluegill sunfish), generated lower pressures than fish with larger mouths, smaller cross-sectional area and shorter moments, such as M. salmoides (largemouth bass). These results reveal a direct trade-off between morphological requirements of feeding on larger prey (larger mouth size relative to body depth) and the ability to generate subambient pressure while suction feeding on elusive prey. PMID:15472018

  5. Autonomous Path-Following by Approximate Inverse Dynamics and Vector Field Prediction

    NASA Astrophysics Data System (ADS)

    Gerlach, Adam R.

    In this dissertation, we develop two general frameworks for the navigation and control of autonomous vehicles that must follow predefined paths. These frameworks are designed such that they inherently provide accurate navigation and control of a wide class of systems directly from a model of the vehicle's dynamics. The first framework introduced is the inverse dynamics by radial basis function (IDRBF) algorithm, which exploits the best approximation property of radial basis functions to accurately approximate the inverse dynamics of non-linear systems. This approximation is then used with the known, desired state of the system at a future time point to generate the system input that must be applied to reach the desired state in the specified time interval. The IDRBF algorithm is then tested on two non-linear dynamic systems, and accurate path-following is demonstrated. The second framework introduced is the predictive vector field (PVF) algorithm. The PVF algorithm uses the equations of motion and constraints of the system to predict a set of reachable states by sampling the system's configuration space. By finding and minimizing a continuous mapping between the system's configuration space and a cost space relating the reachable states of the system with a vector field (VF), one can determine the system inputs required to follow the VF. The PVF algorithm is then tested on the Dubin's vehicle and aircraft models, and accurate path-following is demonstrated. As the PVF algorithm's performance is dependent on the quality of the underlying system model and VF, algorithms are introduced for automatically generating VFs for constant altitude paths defined by a series of waypoints and for handling modeling uncertainties. Additionally, we provide a mathematical proof showing that this method can automatically produce VFs of the desired form. To handle modeling uncertainties, we enhance the PVF algorithm with the Gaussian process machine learning framework, enabling the

  6. High performance CLSM field mixing and pumping test results

    SciTech Connect

    Rajendran, N.; Langton, C.A.

    1997-05-14

    An improved low bleed water CLSM mix was field tested on May 13, 1997 at the Throop portable auger batching plant. Production and pumping tests were very successful. The four cubic yards of material pumped into a ply wood form where it flowed 48 feet (the entire length of the form). The CLSM slurry was very uniform, self leveling, cohesive, showed no segregation, and had no bleed water. Properties of the High Performance CLSM were the same for material collected at the auger and at the end of the pipeline except for the air content which was 5.5% at the auger and 3.2% at the end of the pipeline. This is exactly what was expected and indicates that this CLSM is easy to mix and pump in the Throop/BSRI equipment. CLSM Mix TW-10 is recommended for Tank Closure based on the field batching and pumping tests.

  7. Off-Design Performance Prediction of Gas Turbines without the use of Compressor or Turbine Characteristics

    NASA Astrophysics Data System (ADS)

    Suraweera, Janitha Kanishka

    A new method of predicting gas turbine off-design performance is presented. This method, referred to as the core control method, is based on the idea that performance across a gas turbine depends on a single parameter that controls the energy input to the said gas turbine. It is shown that only the design-point performance of a gas turbine is needed to predict its off-design performance, and that neither compressor nor turbine characteristics are required. A thermodynamic model is developed for predicting the off-design performance of a single-spool turbojet and a two-spool gas generator with a free power turbine. This model is further developed to simulate the effects of handling bleed schedules, performance limiters and performance deterioration. The core control method is then used to predict the off-design performance of a Rolls-Royce Viper Mark 521 as a proof-of-concept, after which, the new and deteriorated off-design performance of three Rolls-Royce RB211-24GT gas turbines is predicted. In addition to the discussions on the involved theories and the performance predictions, the process by which the deteriorated RB211-24GT performance data was analyzed, and the sources and propagation of measurement uncertainties are also discussed.

  8. Cognition and procedure representational requirements for predictive human performance models

    NASA Technical Reports Server (NTRS)

    Corker, K.

    1992-01-01

    Models and modeling environments for human performance are becoming significant contributors to early system design and analysis procedures. Issues of levels of automation, physical environment, informational environment, and manning requirements are being addressed by such man/machine analysis systems. The research reported here investigates the close interaction between models of human cognition and models that described procedural performance. We describe a methodology for the decomposition of aircrew procedures that supports interaction with models of cognition on the basis of procedures observed; that serves to identify cockpit/avionics information sources and crew information requirements; and that provides the structure to support methods for function allocation among crew and aiding systems. Our approach is to develop an object-oriented, modular, executable software representation of the aircrew, the aircraft, and the procedures necessary to satisfy flight-phase goals. We then encode in a time-based language, taxonomies of the conceptual, relational, and procedural constraints among the cockpit avionics and control system and the aircrew. We have designed and implemented a goals/procedures hierarchic representation sufficient to describe procedural flow in the cockpit. We then execute the procedural representation in simulation software and calculate the values of the flight instruments, aircraft state variables and crew resources using the constraints available from the relationship taxonomies. The system provides a flexible, extensible, manipulative and executable representation of aircrew and procedures that is generally applicable to crew/procedure task-analysis. The representation supports developed methods of intent inference, and is extensible to include issues of information requirements and functional allocation. We are attempting to link the procedural representation to models of cognitive functions to establish several intent inference methods

  9. Prediction of the performance of inbred lines derived from a population cross in autumn-sown onions (Allium cepa L.).

    PubMed

    Werner, C P; Kearsey, M J; Crowther, T C; Dowker, B D

    1990-04-01

    A design and model are presented to allow the prediction, in early generations, of the mean and distribution of recombinant inbred lines derived from a cross between two parental populations or partially inbred lines. The procedure has been tested in autumn-sown onions (in the UK) using a wide cross between the openpollinated Japanese cultivar, Senshyu, and a partially inbred line derived from the European cultivar, Rawska. The early generations used for prediction included the first self-pollinated generation of the two parental populations and the F3 generation produced from the hybrid population. The predictions were tested by reference to the field performance of a random array of inbred lines, which were produced by single-seed descent (SSD) and had been selfed for three generations. The early generations, used for prediction, and a sample of SSD lines were raised alongside each other in each of two seasons. Within each season, good agreement was found between the predicted and observed performance of the recombinant inbred lines for three characters - yield, quality and maturity. This is used as evidence of the validity of the genetical model and the assumptions made. The effects of genotype x environment interactions prevented predictions made in one season being reliably applied to those made in the other and, therefore, reduce the attraction of this type of prediction study to the plant breeder. PMID:24226455

  10. The Hurricane Imaging Radiometer (HIRAD): Instrument Status and Performance Predictions

    NASA Technical Reports Server (NTRS)

    Ruf, Christopher; Bailey, M. C.; Gross, Steven; Hood, Robbie; James, Mark; Johnson, James; Jones, Linwood; Miller, Timothy; Uhlhorn, Eric

    2009-01-01

    The Hurricane Imaging Radiometer (HIRAD) is an innovative radiometer which offers new and unique remotely sensed observations of both extreme oceanic wind events and strong precipitation. It is based on the airborne Stepped Frequency Microwave Radiometer (SFMR) [Uhlhorn and Black, 2004]. The HIRAD instrument advances beyond the current nadir viewing SFMR to an equivalent wide-swath SFMR imager using passive microwave synthetic thinned aperture radiometer (STAR) technology [Ruf et al., 1988]. This sensor operates over 4-7 GHz, where the required tropical cyclone remote sensing physics has been validated by both SFMR and WindSat radiometer [Bettenhausen et al., 2006; Brown et al., 2006]. HIRAD incorporates a new and unique array antenna design along with several technologies successfully demonstrated by the Lightweight Rain Radiometer instrument [Ruf et al., 2002; Ruf and Principe, 2003]. HIRAD will be a compact, lightweight, low-power instrument with no moving parts that will produce wide-swath imagery of ocean winds and rain in hurricane conditions. Accurate observations of surface ocean vector winds (OVW) with high spatial and temporal resolution are required for understanding and predicting tropical cyclones. The Hurricane Imaging Radiometer (HIRAD) is an innovative architecture which offers new and unique remotely sensed observations of both extreme oceanic wind events and strong precipitation. It is based on the airborne Stepped Frequency Microwave Radiometer (SFMR), which is a proven remote sensing technique for observing tropical cyclone (TC) ocean surface wind speeds and rain rates. The proposed HIRAD instrument advances beyond the current nadir viewing SFMR to an equivalent wide-swath SFMR imager using passive microwave synthetic thinned aperture radiometer (STAR) technology combined with a a unique array antenna design. The overarching design concept of HIRAD is to combine the multi-frequency C-band observing strategy of the SFMR with STAR technology to

  11. From field to region yield predictions in response to pedo-climatic variations in Eastern Canada

    NASA Astrophysics Data System (ADS)

    JÉGO, G.; Pattey, E.; Liu, J.

    2013-12-01

    The increase in global population coupled with new pressures to produce energy and bioproducts from agricultural land requires an increase in crop productivity. However, the influence of climate and soil variations on crop production and environmental performance is not fully understood and accounted for to define more sustainable and economical management strategies. Regional crop modeling can be a great tool for understanding the impact of climate variations on crop production, for planning grain handling and for assessing the impact of agriculture on the environment, but it is often limited by the availability of input data. The STICS ("Simulateur mulTIdisciplinaire pour les Cultures Standard") crop model, developed by INRA (France) is a functional crop model which has a built-in module to optimize several input parameters by minimizing the difference between calculated and measured output variables, such as Leaf Area Index (LAI). STICS crop model was adapted to the short growing season of the Mixedwood Plains Ecozone using field experiments results, to predict biomass and yield of soybean, spring wheat and corn. To minimize the numbers of inference required for regional applications, 'generic' cultivars rather than specific ones have been calibrated in STICS. After the calibration of several model parameters, the root mean square error (RMSE) of yield and biomass predictions ranged from 10% to 30% for the three crops. A bit more scattering was obtained for LAI (20%performed the best in STICS and to make a preliminary verification of the sensitivity of the biomass prediction to climate variations. Using RS data to re-initialize input parameters that are not readily available (e.g. seeding date) is considered an effective way

  12. Near-field performance assessment for the Saltstone Disposal Facility

    SciTech Connect

    Seitz, R.R.; Dicke, C.A.; Walton, J.C.

    1993-12-31

    A near-field performance assessment (PA) was conducted for the Saltstone Disposal Facility (SDF) at the Savannah River Site in South Carolina. The analysis was conducted in four parts: general screening calculations, degradation calculations, and flow and transport through the fractured and nonfractured facility. Modeling approaches and example sensitivity analysis results from the simulations of the fractured facility are discussed. Design considerations that may not be apparent without addressing flow and transport through fractures and lessons learned during the process are also presented.

  13. Predicting Performance: A Comparison of University Supervisors' Predictions and Teacher Candidates' Scores on a Teaching Performance Assessment

    ERIC Educational Resources Information Center

    Sandholtz, Judith Haymore; Shea, Lauren M.

    2012-01-01

    The implementation of teaching performance assessments has prompted a range of concerns. Some educators question whether these assessments provide information beyond what university supervisors gain through their formative evaluations and classroom observations of candidates. This research examines the relationship between supervisors' predictions…

  14. A new modeling and simulation method for important statistical performance prediction of single photon avalanche diode detectors

    NASA Astrophysics Data System (ADS)

    Xu, Yue; Xiang, Ping; Xie, Xiaopeng; Huang, Yang

    2016-06-01

    This paper presents a new modeling and simulation method to predict the important statistical performance of single photon avalanche diode (SPAD) detectors, including photon detection efficiency (PDE), dark count rate (DCR) and afterpulsing probability (AP). Three local electric field models are derived for the PDE, DCR and AP calculations, which show analytical dependence of key parameters such as avalanche triggering probability, impact ionization rate and electric field distributions that can be directly obtained from Geiger mode Technology Computer Aided Design (TCAD) simulation. The model calculation results are proven to be in good agreement with the reported experimental data in the open literature, suggesting that the proposed modeling and simulation method is very suitable for the prediction of SPAD statistical performance.

  15. Performance prediction of electrohydrodynamic thrusters by the perturbation method

    NASA Astrophysics Data System (ADS)

    Shibata, H.; Watanabe, Y.; Suzuki, K.

    2016-05-01

    In this paper, we present a novel method for analyzing electrohydrodynamic (EHD) thrusters. The method is based on a perturbation technique applied to a set of drift-diffusion equations, similar to the one introduced in our previous study on estimating breakdown voltage. The thrust-to-current ratio is generalized to represent the performance of EHD thrusters. We have compared the thrust-to-current ratio obtained theoretically with that obtained from the proposed method under atmospheric air conditions, and we have obtained good quantitative agreement. Also, we have conducted a numerical simulation in more complex thruster geometries, such as the dual-stage thruster developed by Masuyama and Barrett [Proc. R. Soc. A 469, 20120623 (2013)]. We quantitatively clarify the fact that if the magnitude of a third electrode voltage is low, the effective gap distance shortens, whereas if the magnitude of the third electrode voltage is sufficiently high, the effective gap distance lengthens.

  16. Prediction of the Effect of Vortex Generators on Airfoil Performance

    NASA Astrophysics Data System (ADS)

    Sørensen, Niels N.; Zahle, F.; Bak, C.; Vronsky, T.

    2014-06-01

    Vortex Generators (VGs) are widely used by the wind turbine industry, to control the flow over blade sections. The present work describes a computational fluid dynamic procedure that can handle a geometrical resolved VG on an airfoil section. After describing the method, it is applied to two different airfoils at a Reynolds number of 3 million, the FFA- W3-301 and FFA-W3-360, respectively. The computations are compared with wind tunnel measurements from the Stuttgart Laminar Wind Tunnel with respect to lift and drag variation as function of angle of attack. Even though the method does not exactly capture the measured performance, it can be used to compare different VG setups qualitatively with respect to chord- wise position, inter and intra-spacing and inclination of the VGs already in the design phase.

  17. Correlation of Apollo oxygen tank thermodynamic performance predictions

    NASA Technical Reports Server (NTRS)

    Patterson, H. W.

    1971-01-01

    Parameters necessary to analyze the stratified performance of the Apollo oxygen tanks include g levels, tank elasticity, flow rates and pressurized volumes. Methods for estimating g levels and flow rates from flight plans prior to flight, and from quidance and system data for use in the post flight analysis are described. Equilibrium thermodynamic equations are developed for the effects of tank elasticity and pressurized volumes on the tank pressure response and their relative magnitudes are discussed. Correlations of tank pressures and heater temperatures from flight data with the results of a stratification model are shown. Heater temperatures were also estimated with empirical heat transfer agreement with flight data when fluid properties were averaged rather than evaluated at the mean film temperature.

  18. Aerodynamic performance prediction of horizontal axis wind turbines

    NASA Technical Reports Server (NTRS)

    Jeng, D. R.; Keith, T. G.; Aliakbarkhanafjeh, A.

    1981-01-01

    A new method for calculating the aerodynamic performance of horizontal axis wind turbines is described. The method, entitled the helical vortex method, directly calculates the local induced velocity due to helical vortices that originate at the rotor blade. Furthermore, the method does not require a specified circulation distribution. Results of the method are compared to similar results obtained from Wilson PROP code methods as well as to existing experimental data taken from a Mod-O wind turbine. It is shown that results of the proposed method agree well with experimental values of the power output both near cut-in and at rated wind speeds. Further, it is found that the method does not experience some of the numerical difficulties encountered by the PROP code when run at low wind velocities.

  19. Prediction of pilot-aircraft stability boundaries and performance contours

    NASA Technical Reports Server (NTRS)

    Stengel, R. F.; Broussard, J. R.

    1977-01-01

    Control-theoretic pilot models can provide important new insights regarding the stability and performance characteristics of the pilot-aircraft system. Optimal-control pilot models can be formed for a wide range of flight conditions, suggesting that the human pilot can maintain stability if he adapts his control strategy to the aircraft's changing dynamics. Of particular concern is the effect of sub-optimal pilot adaptation as an aircraft transitions from low to high angle-of-attack during rapid maneuvering, as the changes in aircraft stability and control response can be extreme. This paper examines the effects of optimal and sub-optimal effort during a typical 'high-g' maneuver, and it introduces the concept of minimum-control effort (MCE) adaptation. Limited experimental results tend to support the MCE adaptation concept.

  20. Trends in the predictive performance of raw ensemble weather forecasts

    NASA Astrophysics Data System (ADS)

    Hemri, Stephan; Scheuerer, Michael; Pappenberger, Florian; Bogner, Konrad; Haiden, Thomas

    2015-04-01

    Over the last two decades the paradigm in weather forecasting has shifted from being deterministic to probabilistic. Accordingly, numerical weather prediction (NWP) models have been run increasingly as ensemble forecasting systems. The goal of such ensemble forecasts is to approximate the forecast probability distribution by a finite sample of scenarios. Global ensemble forecast systems, like the European Centre for Medium-Range Weather Forecasts (ECMWF) ensemble, are prone to probabilistic biases, and are therefore not reliable. They particularly tend to be underdispersive for surface weather parameters. Hence, statistical post-processing is required in order to obtain reliable and sharp forecasts. In this study we apply statistical post-processing to ensemble forecasts of near-surface temperature, 24-hour precipitation totals, and near-surface wind speed from the global ECMWF model. Our main objective is to evaluate the evolution of the difference in skill between the raw ensemble and the post-processed forecasts. The ECMWF ensemble is under continuous development, and hence its forecast skill improves over time. Parts of these improvements may be due to a reduction of probabilistic bias. Thus, we first hypothesize that the gain by post-processing decreases over time. Based on ECMWF forecasts from January 2002 to March 2014 and corresponding observations from globally distributed stations we generate post-processed forecasts by ensemble model output statistics (EMOS) for each station and variable. Parameter estimates are obtained by minimizing the Continuous Ranked Probability Score (CRPS) over rolling training periods that consist of the n days preceding the initialization dates. Given the higher average skill in terms of CRPS of the post-processed forecasts for all three variables, we analyze the evolution of the difference in skill between raw ensemble and EMOS forecasts. The fact that the gap in skill remains almost constant over time, especially for near

  1. SEISMIC RESPONSE PREDICTION OF NUPEC'S FIELD MODEL TESTS OF NPP STRUCTURES WITH ADJACENT BUILDING EFFECT.

    SciTech Connect

    XU,J.COSTANTINO,C.HOFMAYER,C.ALI,S.

    2004-03-04

    As part of a verification test program for seismic analysis computer codes for Nuclear Power Plant (NPP) structures, the Nuclear Power Engineering Corporation (NUPEC) of Japan has conducted a series of field model tests to address the dynamic cross interaction (DCI) effect on the seismic response of NPP structures built in close proximity to each other. The program provided field data to study the methodologies commonly associated with seismic analyses considering the DCI effect. As part of a collaborative program between the United States and Japan on seismic issues related to NPP applications, the U.S. Nuclear Regulatory Commission sponsored a program at Brookhaven National Laboratory (BNL) to perform independent seismic analyses which applied common analysis procedures to predict the building response to recorded earthquake events for the test models with DCI effect. In this study, two large-scale DCI test model configurations were analyzed: (1) twin reactor buildings in close proximity and (2) adjacent reactor and turbine buildings. This paper describes the NUPEC DCI test models, the BNL analysis using the SASSI 2000 program, and comparisons between the BNL analysis results and recorded field responses. To account for large variability in the soil properties, the conventional approach of computing seismic responses with the mean, mean plus and minus one-standard deviation soil profiles is adopted in the BNL analysis and the three sets of analysis results were used in the comparisons with the test data. A discussion is also provided in the paper to address (1) the capability of the analysis methods to capture the DCI effect, and (2) the conservatism of the practice for considering soil variability in seismic response analysis for adjacent NPP structures.

  2. High performance ultrasonic field simulation on complex geometries

    NASA Astrophysics Data System (ADS)

    Chouh, H.; Rougeron, G.; Chatillon, S.; Iehl, J. C.; Farrugia, J. P.; Ostromoukhov, V.

    2016-02-01

    Ultrasonic field simulation is a key ingredient for the design of new testing methods as well as a crucial step for NDT inspection simulation. As presented in a previous paper [1], CEA-LIST has worked on the acceleration of these simulations focusing on simple geometries (planar interfaces, isotropic materials). In this context, significant accelerations were achieved on multicore processors and GPUs (Graphics Processing Units), bringing the execution time of realistic computations in the 0.1 s range. In this paper, we present recent works that aim at similar performances on a wider range of configurations. We adapted the physical model used by the CIVA platform to design and implement a new algorithm providing a fast ultrasonic field simulation that yields nearly interactive results for complex cases. The improvements over the CIVA pencil-tracing method include adaptive strategies for pencil subdivisions to achieve a good refinement of the sensor geometry while keeping a reasonable number of ray-tracing operations. Also, interpolation of the times of flight was used to avoid time consuming computations in the impulse response reconstruction stage. To achieve the best performance, our algorithm runs on multi-core superscalar CPUs and uses high performance specialized libraries such as Intel Embree for ray-tracing, Intel MKL for signal processing and Intel TBB for parallelization. We validated the simulation results by comparing them to the ones produced by CIVA on identical test configurations including mono-element and multiple-element transducers, homogeneous, meshed 3D CAD specimens, isotropic and anisotropic materials and wave paths that can involve several interactions with interfaces. We show performance results on complete simulations that achieve computation times in the 1s range.

  3. Carbon diffusion in supersaturated ferrite: a comparison of mean-field and atomistic predictions

    NASA Astrophysics Data System (ADS)

    Lawrence, B.; Sinclair, C. W.; Perez, M.

    2014-09-01

    Hillert's mean-field elastic prediction of the diffusivity of carbon in ferrite is regularly used to explain the experimental observation of slow diffusion of carbon in supersaturated ferrite. With increasing carbon supersaturation, the appropriateness of assuming that many-body carbon interactions can be ignored needs to be re-examined. In this work, we have sought to evaluate the limits of such mean-field predictions for activation barrier prediction by comparing such models with molecular dynamics simulations. The results of this analysis show that even at extremely high levels of supersaturation (up to 8 at% C), mean-field elasticity models can be used with confidence when the effects of carbon concentration on the energy of carbon at octahedral and tetrahedral sites are considered. The reasons for this finding and its consequences are discussed.

  4. A Complete Procedure for Predicting and Improving the Performance of HAWT's

    NASA Astrophysics Data System (ADS)

    Al-Abadi, Ali; Ertunç, Özgür; Sittig, Florian; Delgado, Antonio

    2014-06-01

    A complete procedure for predicting and improving the performance of the horizontal axis wind turbine (HAWT) has been developed. The first process is predicting the power extracted by the turbine and the derived rotor torque, which should be identical to that of the drive unit. The BEM method and a developed post-stall treatment for resolving stall-regulated HAWT is incorporated in the prediction. For that, a modified stall-regulated prediction model, which can predict the HAWT performance over the operating range of oncoming wind velocity, is derived from existing models. The model involves radius and chord, which has made it more general in applications for predicting the performance of different scales and rotor shapes of HAWTs. The second process is modifying the rotor shape by an optimization process, which can be applied to any existing HAWT, to improve its performance. A gradient- based optimization is used for adjusting the chord and twist angle distribution of the rotor blade to increase the extraction of the power while keeping the drive torque constant, thus the same drive unit can be kept. The final process is testing the modified turbine to predict its enhanced performance. The procedure is applied to NREL phase-VI 10kW as a baseline turbine. The study has proven the applicability of the developed model in predicting the performance of the baseline as well as the optimized turbine. In addition, the optimization method has shown that the power coefficient can be increased while keeping same design rotational speed.

  5. Field of view selection for optimal airborne imaging sensor performance

    NASA Astrophysics Data System (ADS)

    Goss, Tristan M.; Barnard, P. Werner; Fildis, Halidun; Erbudak, Mustafa; Senger, Tolga; Alpman, Mehmet E.

    2014-05-01

    The choice of the Field of View (FOV) of imaging sensors used in airborne targeting applications has major impact on the overall performance of the system. Conducting a market survey from published data on sensors used in stabilized airborne targeting systems shows a trend of ever narrowing FOVs housed in smaller and lighter volumes. This approach promotes the ever increasing geometric resolution provided by narrower FOVs, while it seemingly ignores the influences the FOV selection has on the sensor's sensitivity, the effects of diffraction, the influences of sight line jitter and collectively the overall system performance. This paper presents a trade-off methodology to select the optimal FOV for an imaging sensor that is limited in aperture diameter by mechanical constraints (such as space/volume available and window size) by balancing the influences FOV has on sensitivity and resolution and thereby optimizing the system's performance. The methodology may be applied to staring array based imaging sensors across all wavebands from visible/day cameras through to long wave infrared thermal imagers. Some examples of sensor analysis applying the trade-off methodology are given that highlights the performance advantages that can be gained by maximizing the aperture diameters and choosing the optimal FOV for an imaging sensor used in airborne targeting applications.

  6. Performance Prediction Method of CO2 Cycle for Air Cooling

    NASA Astrophysics Data System (ADS)

    Koyama, Shigeru; Xue, Jun; Kuwahara, Ken

    From the perspective of global environmental protection and energy-saving, the research and development on high-efficiency heat pump and refrigeration systems using environment-friendly refrigerants have become one of the most important issues in the air-conditioning and refrigeration sector. In the present work, a steady-state model of the CO2 transcritical cycle for air cooling, which consists of a rotary compressor, a fin-tube gas cooler,a fin-tube evaporator and an expansion valve, has been developed. The detailed model of fin-tube heat exchanger has been constructed by means of the finite volume method, in which the local heat transfer and flow characteristics are evaluated. It should be noted that the effects of the dew condensation generated on the cooling surface are considered in the evaporator model. As a calculation example, the effects of the indoor air wet-bulb temperature on the cycle performance have been examined with this developed simulator.

  7. Working memory capacity predicts conflict-task performance.

    PubMed

    Gulbinaite, Rasa; Johnson, Addie

    2014-01-01

    The relationship between the ability to maintain task goals and working memory capacity (WMC) is firmly established, but evidence for WMC-related differences in conflict processing is mixed. We investigated whether WMC (measured using two complex-span tasks) mediates differences in adjustments of cognitive control in response to conflict. Participants performed a Simon task in which congruent and incongruent trials were equiprobable, but in which the proportion of congruency repetitions (congruent trials followed by congruent trials or incongruent trials followed by incongruent trials) and thus the need for trial-by-trial adjustments in cognitive control varied by block. The overall Simon effect did not depend on WMC capacity. However, for the low-WMC participants the Simon effect decreased as the proportion of congruency repetitions decreased, whereas for the high- and average-WMC participants it was relatively constant across conditions. Distribution analysis of the Simon effect showed more evidence for the inhibition of stimulus location in the low- than in the high-WMC participants, especially when the proportion of congruency repetitions was low. We hypothesize that low-WMC individuals exhibit more interference from task-irrelevant information due to weaker preparatory control prior to stimulus presentation and, thus, stronger reliance on reactive recruitment of cognitive control. PMID:24199908

  8. Energy deposition via magnetoplasmadynamic acceleration: II. modeling and performance predictions

    NASA Astrophysics Data System (ADS)

    Mikellides, P. G.; England, B.; Gilland, J. H.

    2009-02-01

    A time-dependent, two-dimensional, axisymmetric magnetohydrodynamics code is employed to model, validate and extend the experimentally-limited performance characteristics of a gigawatt-level plasma source that utilized magnetoplasmadynamic (MPD) acceleration for gas energy deposition. Accurate modeling required an upgrade of the code's circuit routines to properly capture the pulse-forming-network current waveform which also serves as the primary variable for validation. Comparisons with experimentally deduced current waveforms were in good agreement for all power levels. The simulations also produced values for the plasma voltage which were compared with the measured voltage across the electrodes. The trend agreement was encouraging while the magnitude of the discrepancy is approximately constant and interpreted as a representation of the electrode fall voltage. Force computations captured the expected electromagnetic acceleration trends and serve as further verification. They also allow examination of the device as a very high power MPD thruster operating at power levels in excess of 180 MW. The computations offer insights into the plasma's characteristics at different power levels through two-dimensional distributions of pertinent parameters and identify design guidelines for effective stagnation temperature values as a function of the mass-flow rate.

  9. Performance of field emission cathodes in xenon environments

    SciTech Connect

    Marrese, C.M.; Polk, J.E.; Jensen, K.L.; Gallimore, A.D.; Spindt, C.; Fink, R.L.; Tolt, Z.L.; Palmer, W.D.

    1999-07-01

    Field emission (FE) cathodes are currently being considered to supply electrons in electric propulsion systems for propellant ionization and ion beam neutralization. Hollow cathodes with thermionic electron emitters typically used with Hall and ion thrusters require propellant and heaters for operation. Therefore there are lower limits on their size and power. Because FE cathodes do not require propellant or heaters they can be used with small and micropropulsion systems. The primary concern with integrating these two technologies is cathode lifetime. An FE cathode must be capable of operation in a plasma environment where xenon pressures exceed 2 x 10{sup {minus}6} Torr. Experiments were conducted at the Jet Propulsion Laboratory to evaluate the performance of silicon and molybdenum microtip field emission array cathodes, and carbon film cathodes in xenon pressures up to 2 x 10{sup {minus}5} Torr. Experimental and modeling results were used to determine energy thresholds for sputtering silicon and molybdenum by xenon ions. Experiments and theoretical results are presented for performance degradation in xenon environments.

  10. Prediction of natural disasters basing of chrono-and-information field characters

    NASA Astrophysics Data System (ADS)

    Sapunov, Valentin

    2013-04-01

    Living organisms are able to predict some future events particular catastrophic incidents. This is adaptive characters producing by evolution. The more energy produces incident the more possibility to predict one. Wild animals escaped natural hazards including tsunami (e.g. extremal tsunami in Asia December 2004). Living animals are able to predict strong phenomena of obscure nature. For example majority of animals escaped Tungus catastrophe taking place in Siberia at 1908. Wild animals are able to predict nuclear weapon experiences. The obscure characters are not typical for human, but they are fixed under probability 15%. Such were summarized by L.Vasiliev (1961). Effective theory describing such a characters is absent till now. N.Kozyrev (1991) suggested existence of unknown physical field (but gravitation and electro magnetic). The field was named "time" or "chrono". Some characters of the field appeared to be object of physical experiment. Kozyrev suggested specific role of the field for function of living organisms. Transition of biological information throw space (telepathy) and time (proscopy) may be based on characters of such a field. Hence physical chrono-and-information field is under consideration. Animals are more familiar with such a field than human. Evolutionary process experienced with possibility of extremal development of contact with such a field using highest primates. This mode of evolution appeared to stay obscure producing probable species "Wildman" (Bigfoot). Specific adaptive fitches suggest impossibility to study of such a species by usual ecological approaches. The perspective way for study of mysterious phenomena of physic is researches of this field characters.

  11. Predicting the sun's polar magnetic fields with a surface flux transport model

    SciTech Connect

    Upton, Lisa; Hathaway, David H. E-mail: lar0009@uah.edu

    2014-01-01

    The Sun's polar magnetic fields are directly related to solar cycle variability. The strength of the polar fields at the start (minimum) of a cycle determine the subsequent amplitude of that cycle. In addition, the polar field reversals at cycle maximum alter the propagation of galactic cosmic rays throughout the heliosphere in fundamental ways. We describe a surface magnetic flux transport model that advects the magnetic flux emerging in active regions (sunspots) using detailed observations of the near-surface flows that transport the magnetic elements. These flows include the axisymmetric differential rotation and meridional flow and the non-axisymmetric cellular convective flows (supergranules), all of which vary in time in the model as indicated by direct observations. We use this model with data assimilated from full-disk magnetograms to produce full surface maps of the Sun's magnetic field at 15 minute intervals from 1996 May to 2013 July (all of sunspot cycle 23 and the rise to maximum of cycle 24). We tested the predictability of this model using these maps as initial conditions, but with daily sunspot area data used to give the sources of new magnetic flux. We find that the strength of the polar fields at cycle minimum and the polar field reversals at cycle maximum can be reliably predicted up to 3 yr in advance. We include a prediction for the cycle 24 polar field reversal.

  12. Predicting wind field in the Bay of Bengal from scatterometer observations using genetic algorithm

    NASA Astrophysics Data System (ADS)

    Sharma, Rashmi; Sarkar, Abhijit; Agarwal, Neeraj; Kumar, Raj; Basu, Sujit

    2007-02-01

    A technique based on genetic algorithm (GA) is applied for predicting wind field in the Bay of Bengal (BOB) using satellite scatterometer observations. Empirical orthogonal function (EOF) analysis is used for compressing the spatial variability into a set of eigenmodes. The time series of each principal component (PC) is subjected to singular spectrum analysis (SSA) and GA is applied to the resulting filtered time series. The forecast PCs are weighted by the spatial eigenmodes for computing forecast wind fields. Predictions made up to 5 days in advance are found to be superior to forecast by persistence method.

  13. Prediction of sound fields in acoustical cavities using the boundary element method. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Kipp, C. R.; Bernhard, R. J.

    1985-01-01

    A method was developed to predict sound fields in acoustical cavities. The method is based on the indirect boundary element method. An isoparametric quadratic boundary element is incorporated. Pressure, velocity and/or impedance boundary conditions may be applied to a cavity by using this method. The capability to include acoustic point sources within the cavity is implemented. The method is applied to the prediction of sound fields in spherical and rectangular cavities. All three boundary condition types are verified. Cases with a point source within the cavity domain are also studied. Numerically determined cavity pressure distributions and responses are presented. The numerical results correlate well with available analytical results.

  14. Exchange and electric fields enhanced spin thermoelectric performance of germanene nano-ribbon.

    PubMed

    Zheng, Jun; Chi, Feng; Guo, Yong

    2015-07-29

    The spin thermoelectric performance in a germanene nano-ribbon is studied by using the nonequilibrium Green's function method. We demonstrate theoretically that the temperature bias [Formula: see text] can generate spin thermopower when an exchange field breaks the edge states of germanene leads. However, the spin thermoelectric efficiency is quite low with its maximum [Formula: see text]. When applying strong electric field in the central region, a relatively large spin-dependent band gap can be opened, and hence the spin figure of merit is predicted to be more than 100 times larger than the case without external field. The remarkably enhancement of [Formula: see text] (larger than one) comes from the suppression of the thermal conductance and the improvement of the spin Seebeck effect. These striking properties make ferromagnetic leads germanene nano-ribbon a promising pure spin thermoelectric nanogenerator. PMID:26139695

  15. Performance prediction of four-contact vertical Hall-devices using a conformal mapping technique

    NASA Astrophysics Data System (ADS)

    Yang, Huang; Yue, Xu; Yufeng, Guo

    2015-12-01

    Instead of the conventional design with five contacts in the sensor active area, innovative vertical Hall devices (VHDs) with four contacts and six contacts are asymmetrical in structural design but symmetrical in the current flow that can be well fit for the spinning current technique for offset elimination. In this article, a conformal mapping calculation method is used to predict the performance of asymmetrical VHD embedded in a deep n-well with four contacts. Furthermore, to make the calculation more accurate, the junction field effect is also involved into the conformal mapping method. The error between calculated and simulated results is less than 5% for the current-related sensitivity, and approximately 13% for the voltage-related sensitivity. This proves that such calculations can be used to predict the optimal structure of the vertical Hall-devices. Project supported by the Natural Science Foundation of Jiangsu Province, China (Nos. BK20131379, BK20141431) and the Graduate Research and Innovation Projects of Jiangsu Province (No. SJLX_0373).

  16. A Unified Model of Performance: Validation of its Predictions across Different Sleep/Wake Schedules

    PubMed Central

    Ramakrishnan, Sridhar; Wesensten, Nancy J.; Balkin, Thomas J.; Reifman, Jaques

    2016-01-01

    Study Objectives: Historically, mathematical models of human neurobehavioral performance developed on data from one sleep study were limited to predicting performance in similar studies, restricting their practical utility. We recently developed a unified model of performance (UMP) to predict the effects of the continuum of sleep loss—from chronic sleep restriction (CSR) to total sleep deprivation (TSD) challenges—and validated it using data from two studies of one laboratory. Here, we significantly extended this effort by validating the UMP predictions across a wide range of sleep/wake schedules from different studies and laboratories. Methods: We developed the UMP on psychomotor vigilance task (PVT) lapse data from one study encompassing four different CSR conditions (7 d of 3, 5, 7, and 9 h of sleep/night), and predicted performance in five other studies (from four laboratories), including different combinations of TSD (40 to 88 h), CSR (2 to 6 h of sleep/night), control (8 to 10 h of sleep/night), and nap (nocturnal and diurnal) schedules. Results: The UMP accurately predicted PVT performance trends across 14 different sleep/wake conditions, yielding average prediction errors between 7% and 36%, with the predictions lying within 2 standard errors of the measured data 87% of the time. In addition, the UMP accurately predicted performance impairment (average error of 15%) for schedules (TSD and naps) not used in model development. Conclusions: The unified model of performance can be used as a tool to help design sleep/wake schedules to optimize the extent and duration of neurobehavioral performance and to accelerate recovery after sleep loss. Citation: Ramakrishnan S, Wesensten NJ, Balkin TJ, Reifman J. A unified model of performance: validation of its predictions across different sleep/wake schedules. SLEEP 2016;39(1):249–262. PMID:26518594

  17. Validation of a Previously Developed Geospatial Model That Predicts the Prevalence of Listeria monocytogenes in New York State Produce Fields

    PubMed Central

    Weller, Daniel; Shiwakoti, Suvash; Bergholz, Peter; Grohn, Yrjo; Wiedmann, Martin

    2015-01-01

    Technological advancements, particularly in the field of geographic information systems (GIS), have made it possible to predict the likelihood of foodborne pathogen contamination in produce production environments using geospatial models. Yet, few studies have examined the validity and robustness of such models. This study was performed to test and refine the rules associated with a previously developed geospatial model that predicts the prevalence of Listeria monocytogenes in produce farms in New York State (NYS). Produce fields for each of four enrolled produce farms were categorized into areas of high or low predicted L. monocytogenes prevalence using rules based on a field's available water storage (AWS) and its proximity to water, impervious cover, and pastures. Drag swabs (n = 1,056) were collected from plots assigned to each risk category. Logistic regression, which tested the ability of each rule to accurately predict the prevalence of L. monocytogenes, validated the rules based on water and pasture. Samples collected near water (odds ratio [OR], 3.0) and pasture (OR, 2.9) showed a significantly increased likelihood of L. monocytogenes isolation compared to that for samples collected far from water and pasture. Generalized linear mixed models identified additional land cover factors associated with an increased likelihood of L. monocytogenes isolation, such as proximity to wetlands. These findings validated a subset of previously developed rules that predict L. monocytogenes prevalence in produce production environments. This suggests that GIS and geospatial models can be used to accurately predict L. monocytogenes prevalence on farms and can be used prospectively to minimize the risk of preharvest contamination of produce. PMID:26590280

  18. Subjective preference evaluation of sound fields by performing singers

    NASA Astrophysics Data System (ADS)

    Noson, Dennis

    2003-08-01

    A model of the auditory process is proposed for performing singers, which incorporates the added signal from bone conduction, as well as the psychological distance for subjective preference of the performer from the acoustic sound field of the stage. The explanatory power of previous scientific studies of vocal stage acoustics has been limited by a lack of an underlying theory of performer preference. Ando's theory, using the autocorrelation function (ACF) for parametrizing temporal factors, was applied to interpretation of singer sound field preference determined by the pair comparison method. Melisma style singing (no lyrics) was shown to increase the preferred delay time of reflections from a mean of 14 ms with lyrics to 23 ms without (p<0.05). The extent of the shift in preferred time delay was shown to be directly related to minima of the effective duration of the running ACF, (τe)min, calculated from each singer's voice. Voice matching experiments for singers demonstrated a strong overestimate of the voice outside the head compared with the singer's own voice (22.4 dB overestimate, p<0.01). Individual singer melisma singing delay preferences were compared for ``ah'' versus ``hum'' syllables, and the increased delay preference (41 ms) was shown to be correlated with (τe)min (r2<0.68, p<0.01). When the proposed bone conduction model was applied, using the measured overestimate of sound level of the singer's own voice for each singer (9.9 dB mean overestimate difference between ``ah'' and ``hum,'' p<0.01), the relationship of singer preference to (τe)min was improved (r2=0.97, p<0.01). Thesis advisor: Yoichi Ando Copies of this thesis are available from the author by inquiry at BRC Acoustics, 1741 First Avenue South, Seattle, WA 98134 USA. E-mail address: dnoson@brcacoustics.com

  19. Relationships Between Anaerobic Performance, Field Tests and Game Performance of Sitting Volleyball Players

    PubMed Central

    Marszalek, Jolanta; Molik, Bartosz; Gomez, Miguel Angel; Skučas, Kęstutis; Lencse-Mucha, Judit; Rekowski, Witold; Pokvytyte, Vaida; Rutkowska, Izabela; Kaźmierska-Kowalewska, Kalina

    2015-01-01

    The aim of this study was to evaluate relationships between anaerobic performance, field tests, game performance and anthropometric variables of sitting volleyball players. Twenty elite Polish sitting volleyball players were tested using the 30 s Wingate Anaerobic Test for arm crank ergometer and participated in six physical field tests. Heights in position to block and to spike, as well as arm reach were measured. Players were observed during the game on the court in terms of effectiveness of the serve, block, attack, receive and defense. Pearson analysis and the Spearman’s rank correlation coefficient were used. The strongest correlations were found between the chest pass test and mean power and peak power (r=.846; p=.001 and r=.708; p=.0005, respectively), and also between the T-test and peak power (r= −.718; p=.001). Mean power correlated with the 3 m test (r= −.540; p=.014), the 5 m test (r= −.592; p=.006), and the T-test (r= −.582; p=.007). Peak power correlated with the 3 m test (r= −.632; p=.003), the 5 m test (r= −.613; p=.004), speed & agility (r= −.552; p=.012) and speed & endurance (r=−.546; p=.013). Significant correlations were observed between anthropometric parameters and anaerobic performance variables (p≤.001), and also between anthropometric parameters and field tests (p≤.05). Game performance and physical fitness of sitting volleyball players depended on their anthropometric variables: reach of arms, the position to block and to spike. The chest pass test could be used as a non-laboratory field test of anaerobic performance of sitting volleyball players. PMID:26834870

  20. Relationships Between Anaerobic Performance, Field Tests and Game Performance of Sitting Volleyball Players.

    PubMed

    Marszalek, Jolanta; Molik, Bartosz; Gomez, Miguel Angel; Skučas, Kęstutis; Lencse-Mucha, Judit; Rekowski, Witold; Pokvytyte, Vaida; Rutkowska, Izabela; Kaźmierska-Kowalewska, Kalina

    2015-11-22

    The aim of this study was to evaluate relationships between anaerobic performance, field tests, game performance and anthropometric variables of sitting volleyball players. Twenty elite Polish sitting volleyball players were tested using the 30 s Wingate Anaerobic Test for arm crank ergometer and participated in six physical field tests. Heights in position to block and to spike, as well as arm reach were measured. Players were observed during the game on the court in terms of effectiveness of the serve, block, attack, receive and defense. Pearson analysis and the Spearman's rank correlation coefficient were used. The strongest correlations were found between the chest pass test and mean power and peak power (r=.846; p=.001 and r=.708; p=.0005, respectively), and also between the T-test and peak power (r= -.718; p=.001). Mean power correlated with the 3 m test (r= -.540; p=.014), the 5 m test (r= -.592; p=.006), and the T-test (r= -.582; p=.007). Peak power correlated with the 3 m test (r= -.632; p=.003), the 5 m test (r= -.613; p=.004), speed & agility (r= -.552; p=.012) and speed & endurance (r=-.546; p=.013). Significant correlations were observed between anthropometric parameters and anaerobic performance variables (p≤.001), and also between anthropometric parameters and field tests (p≤.05). Game performance and physical fitness of sitting volleyball players depended on their anthropometric variables: reach of arms, the position to block and to spike. The chest pass test could be used as a non-laboratory field test of anaerobic performance of sitting volleyball players. PMID:26834870

  1. Lift-Off Acoustics Prediction of Clustered Rocket Engines in the Near Field

    NASA Technical Reports Server (NTRS)

    Vu, Bruce; Plotkin, Ken

    2010-01-01

    This slide presentation presents a method of predicting acoustics during lift-off of the clustered rocket engines in the near field. Included is a definition of the near field, and the use of deflectors and shielding. There is discussion about the use of PAD, a software system designed to calculate the acoustic levels from the lift of of clustered rocket enginee, including updates to extend the calculation to directivity, water suppression, and clustered nozzles.

  2. Premium performance heating oil - Part 2, Field trial results

    SciTech Connect

    Jetter, S.M.; Hoskin, D.; McClintock, W.R.

    1996-07-01

    Limited field trial results of a heating oil additive package developed to minimize unscheduled maintenance indicate that it achieves its goal of keeping heating oil systems cleaner. The multifunctional additive package was developed to provide improved fuel oxidation stability, improved corrosion protection, and dispersency. This combination of performance benefits was chosen because we believed it would retard the formation of sludge, as well as allow sludge already present to be carried through the system without fouling the fuel system components (dispersency should keep sludge particles small so they pass through the filtering system). Since many unscheduled maintenance calls are linked to fouling of the fuel filtering system, the overall goal of this technology is to reduce these maintenance calls. Photographic evidence shows that the additive package not only reduces the amount of sludge formed, but even removes existing sludge from filters and pump strainers. This {open_quotes}clean-up{close_quotes} performance is provided trouble free: we found no indication that nozzle/burner performance was impaired by dispersing sludge from filters and pump strainers. Qualitative assessments from specific accounts that used the premium heating oil also show marked reductions in unscheduled maintenance.

  3. Noise predictions of a high bypass turbofan engine using the Lockheed Near-Field Noise Prediction Program

    NASA Technical Reports Server (NTRS)

    Rawls, J. W., Jr.

    1986-01-01

    The prediction of engine noise during cruise using the Near-Field Noise Prediction Program developed by Lockheed is examined. Test conditions were established which simulate the operation of a high bypass turbofan engine under a wide range of operating conditions. These test conditions include variations in altitude, flight Mach number and thrust setting. Based on the results of noise prediction made using the Lockheed program, an evaluation of the impact of these test conditions on the overall sound pressure level(OASPL)and the one-third octave band spectra is made. An evaluation of the sensitivity of flight condition parameters is also made. The primary noise source from a high bypass turbofan was determined to be fan broadband shock noise. This noise source can be expected to be present during normal cruising conditions. When present, fan broadband shock noise usually dominates at all frequencies and all directivity angles. Other noise sources of importance are broadband shock noise from the primary jet, fan noise, fan mixing noise and turbine noise.

  4. Predicting Modes of the Unsteady Vorticity Field near the Trailing Edge of a Blade

    NASA Technical Reports Server (NTRS)

    Devenport, William J.; Spitz, Nicolas; Envia, Edmane (Technical Monitor)

    2003-01-01

    Progress on predicting modes of the unsteady velocity/vorticity field of a turbulent boundary layer from Reynolds stress statistics is described. Prediction of these modes, that provide the source terms for trailing edge noise predictions in aircraft engine fans and other configurations, will allow for the first time detailed viscous flow effects to be included in such noise calculations. The key accomplishments of this work in FY02 are: (1) The development of a Matlab code for the prediction of modes in two- and three-dimensional boundary layers, previously applied to plane wakes; (2) Predictions with the code using a constant lengthscale formulation in a fully developed turbulence channel flow. Comparison of these boundary layer predictions with available DNS simulation results; and (3) Formulation of an improved model using a variable lengthscale proportional to mixing length. Turbulent channel flow predictions and comparison with DNS results. This work is being carried out in continuous communication and collaboration with the Glegg research group at Florida Atlantic University, which will be incorporating mode predictions into engine noise calculations.

  5. The state of the art of predicting noise-induced sleep disturbance in field settings.

    PubMed

    Fidell, Sanford; Tabachnick, Barbara; Pearsons, Karl S

    2010-01-01

    Several relationships between intruding noises (largely aircraft) and sleep disturbance have been inferred from the findings of a handful of field studies. Comparisons of sleep disturbance rates predicted by the various relationships are complicated by inconsistent data collection methods and definitions of predictor variables and predicted quantities. None of the relationships is grounded in theory-based understanding, and some depend on questionable statistical assumptions and analysis procedures. The credibility, generalizability, and utility of sleep disturbance predictions are also limited by small and nonrepresentative samples of test participants, and by restricted (airport-specific and relatively short duration) circumstances of exposure. Although expedient relationships may be the best available, their predictions are of only limited utility for policy analysis and regulatory purposes, because they account for very little variance in the association between environmental noise and sleep disturbance, have characteristically shallow slopes, have not been well validated in field settings, are highly context-dependent, and do not squarely address the roles and relative importance of nonacoustic factors in sleep disturbance. Such relationships offer the appearance more than the substance of precision and objectivity. Truly useful, population-level prediction and genuine understanding of noise-induced sleep disturbance will remain beyond reach for the foreseeable future, until the findings of field studies of broader scope and more sophisticated design become available. PMID:20472953

  6. The influence of the tropics on the prediction of ultralong waves. I - Tropical wind field

    NASA Technical Reports Server (NTRS)

    Baker, W. E.; Paegle, J.

    1983-01-01

    The effects of tropical wind data from the FGGE and tropical latent heating on numerical modeling of ultralong waves are considered in a two-part study. The model studied is the global fourth-order GLAS general circulation model, an energy-conserving format with horizontal differences calculated with fourth-order accuracy. Data assimilation experiments were performed with and without the wind data, with account taken of eastward and northward wind components, the geopotential height, and the relative humidity, all over pressure surfaces. The initial conditions were used to generate six pairs of forecasts, and the tropical wind error decreased after two days of prediction when the initial conditions contained the wind data. The deviations from the measured planetary wave data were attributed to differences in the initial rotational wind field, which varied on a three-day basis. The latent heat initial data had a five-day period and extended its influence beyond the tropical zone. The tropical heat sources sustained the tropical westerlies in the GLAS model, and removal of the tropical heat sources reversed the wind to easterlies.

  7. Impact of graphene polycrystallinity on the performance of graphene field-effect transistors

    SciTech Connect

    Jiménez, David; Chaves, Ferney; Cummings, Aron W.; Van Tuan, Dinh; Kotakoski, Jani; Roche, Stephan

    2014-01-27

    We have used a multi-scale physics-based model to predict how the grain size and different grain boundary morphologies of polycrystalline graphene will impact the performance metrics of graphene field-effect transistors. We show that polycrystallinity has a negative impact on the transconductance, which translates to a severe degradation of the maximum and cutoff frequencies. On the other hand, polycrystallinity has a positive impact on current saturation, and a negligible effect on the intrinsic gain. These results reveal the complex role played by graphene grain boundaries and can be used to guide the further development and optimization of graphene-based electronic devices.

  8. A Prediction Model for Community Colleges Using Graduation Rate as the Performance Indicator

    ERIC Educational Resources Information Center

    Moosai, Susan

    2010-01-01

    In this thesis a prediction model using graduation rate as the performance indicator is obtained for community colleges for three cohort years, 2003, 2004, and 2005 in the states of California, Florida, and Michigan. Multiple Regression analysis, using an aggregate of seven predictor variables, was employed in determining this prediction model.…

  9. Predicting Academic Performance in Children with Language Impairment: The Role of Parent Report

    ERIC Educational Resources Information Center

    Hall, Nancy E.; Segarra, Veronica Rosa

    2007-01-01

    This study examines the ability of preschool speech-language measures and parent report in predicting later academic performance. Preschool measures of speech, language and communication for 35 children with language impairment were analyzed for their ability to predict reading, writing, spelling, and mathematics in these same children at age…

  10. Analyzing Log Files to Predict Students' Problem Solving Performance in a Computer-Based Physics Tutor

    ERIC Educational Resources Information Center

    Lee, Young-Jin

    2015-01-01

    This study investigates whether information saved in the log files of a computer-based tutor can be used to predict the problem solving performance of students. The log files of a computer-based physics tutoring environment called Andes Physics Tutor was analyzed to build a logistic regression model that predicted success and failure of students'…

  11. Actuarial Prediction of Performance in a Six-Year A.B.-M.D. Program

    ERIC Educational Resources Information Center

    Hess, Thomas G.; Brown, Donald R.

    1977-01-01

    Four actuarial equations for predicting an academic performance criterion were developed and assessed at the University of Michigan. It was concluded that appropriately done actuarial prediction of an individual criterion is more efficient than the efforts of an admissions committee. (LBH)

  12. Predicting Story Goodness Performance from Cognitive Measures Following Traumatic Brain Injury

    ERIC Educational Resources Information Center

    Le, Karen; Coelho, Carl; Mozeiko, Jennifer; Krueger, Frank; Grafman, Jordan

    2012-01-01

    Purpose: This study examined the prediction of performance on measures of the Story Goodness Index (SGI; Le, Coelho, Mozeiko, & Grafman, 2011) from executive function (EF) and memory measures following traumatic brain injury (TBI). It was hypothesized that EF and memory measures would significantly predict SGI outcomes. Method: One hundred…

  13. Goal orientation and work role performance: predicting adaptive and proactive work role performance through self-leadership strategies.

    PubMed

    Marques-Quinteiro, Pedro; Curral, Luís Alberto

    2012-01-01

    This article explores the relationship between goal orientation, self-leadership dimensions, and adaptive and proactive work role performances. The authors hypothesize that learning orientation, in contrast to performance orientation, positively predicts proactive and adaptive work role performances and that this relationship is mediated by self-leadership behavior-focused strategies. It is posited that self-leadership natural reward strategies and thought pattern strategies are expected to moderate this relationship. Workers (N = 108) from a software company participated in this study. As expected, learning orientation did predict adaptive and proactive work role performance. Moreover, in the relationship between learning orientation and proactive work role performance through self-leadership behavior-focused strategies, a moderated mediation effect was found for self-leadership natural reward and thought pattern strategies. In the end, the authors discuss the results and implications are discussed and future research directions are proposed. PMID:23094471

  14. Field Performance of Heat Pump Water Heaters in the Northeast

    SciTech Connect

    Shapiro, C.; Puttagunta, S.

    2013-08-01

    Heat pump water heaters (HPWHs) are finally entering the mainstream residential water heater market. Potential catalysts are increased consumer demand for higher energy efficiency electric water heating and a new Federal water heating standard that effectively mandates use of HPWHs for electric storage water heaters with nominal capacities greater than 55 gallons. When compared to electric resistance water heating, the energy and cost savings potential of HPWHs is tremendous. Converting all electric resistance water heaters to HPWHs could save American consumers 7.8 billion dollars annually ($182 per household) in water heating operating costs and cut annual residential source energy consumption for water heating by 0.70 quads. Steven Winter Associates, Inc. embarked on one of the first in situ studies of these newly released HPWH products through a partnership with two sponsoring electric utility companies, National Grid and NSTAR, and one sponsoring energy efficiency service program administrator, Cape Light Compact. Recent laboratory studies have measured performance of HPWHs under various operating conditions, but publicly available field studies have not been as available. This evaluation attempts to provide publicly available field data on new HPWHs by monitoring the performance of three recently released products (General Electric GeoSpring(tm), A.O. Smith Voltex(r), and Stiebel Eltron Accelera(r)300). Fourteen HPWHs were installed in Massachusetts and Rhode Island and monitored for over a year. Of the 14 units, ten were General Electric models (50 gallon units), two were Stiebel Eltron models (80 gallon units), and two were A.O. Smith models (one 60-gallon and one 80-gallon unit).

  15. Mentoring Support and Power: A Three Year Predictive Field Study on Protege Networking and Career Success

    ERIC Educational Resources Information Center

    Blickle, Gerhard; Witzki, Alexander H.; Schneider, Paula B.

    2009-01-01

    Career success of early employees was analyzed from a power perspective and a developmental network perspective. In a predictive field study with 112 employees mentoring support and mentors' power were assessed in the first wave, employees' networking was assessed after two years, and career success (i.e. income and hierarchical position) and…

  16. SENSITIVITY OF REGIONAL OXIDANT MODEL PREDICTIONS TO PROGNOSTIC AND DIAGNOSTIC METEOROLOGICAL FIELDS

    EPA Science Inventory

    Objective analysis and diagnostic methods are used to provide hourly meteorological fields to many air quality simulation models. he viability of using prognostic predictions from the Mesoscale Model Version 4 together with four-dimensional data assimilation techniques (MM4-FDDA)...

  17. Statistical models for the prediction of field scale, spatial salinity patterns from soil conductivity survey data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A practical linear regression based methodology for the prediction of field scale, spatial salinity patterns from soil conductivity survey data is presented in this chapter. The connection between an ordinary linear regression model and the geostatistical mixed linear model is reviewed, along with ...

  18. Prediction of the Acoustic Field Associated with Instability Wave Source Model for a Compressible Jet

    NASA Technical Reports Server (NTRS)

    Golubev, Vladimir; Mankbadi, Reda R.; Dahl, Milo D.; Kiraly, L. James (Technical Monitor)

    2002-01-01

    This paper provides preliminary results of the study of the acoustic radiation from the source model representing spatially-growing instability waves in a round jet at high speeds. The source model is briefly discussed first followed by the analysis of the produced acoustic directivity pattern. Two integral surface techniques are discussed and compared for prediction of the jet acoustic radiation field.

  19. “Buzz-saw” noise: Prediction of the rotor-alone pressure field

    NASA Astrophysics Data System (ADS)

    McAlpine, A.; Schwaller, P. J. G.; Fisher, M. J.; Tester, B. J.

    2012-10-01

    Public expectations of lower environmental noise levels, and increasingly stringent legislative limits on aircraft noise, result in noise being a critical technical issue in the development of jet engines. Noise at take-off, when the engines are at high-power operating conditions, is a key reference level for engine noise certification. "Buzz-saw" noise is the dominant fan tone noise from modern high-bypass-ratio turbofan aircraft engines during take-off. Rotor-alone tones are the key component of buzz-saw noise. The rotor-alone pressure field is cut-off at subsonic fan tip speeds; buzz-saw noise is associated with supersonic fan tip speeds, or equivalently, high power engine operating conditions. A recent series of papers has described new work concerning the prediction of buzz-saw noise. The prediction method is based on modelling the nonlinear propagation of one-dimensional sawtooth waveforms. A sawtooth waveform is a simplified representation of the rotor-alone pressure field. Previous validation of the prediction method focussed entirely on reproducing the spectral characteristics of buzz-saw noise; this was dictated at that time by the availability of spectral data only for comparison between measurement and prediction. In this paper, full validation of the method by comparing measurement and prediction of the rotor-alone pressure field is published for the first time. It is shown that results from the modelling based on a one-dimensional sawtooth waveform capture the essential features of the rotor-alone pressure field as it propagates upstream inside a hard-walled inlet duct. This verifies that predictions of the buzz-saw noise spectrum, which are in good agreement with the measured data, are based on a model which reproduces the key physics of the noise generation process. Validation results for the rotor-alone pressure field in an acoustically lined inlet duct are also shown. Comparisons of the measured and predicted rotor-alone pressure field are more

  20. Metal accumulation in the earthworm Lumbricus rubellus. Model predictions compared to field data

    USGS Publications Warehouse

    Veltman, K.; Huijbregts, M.A.J.; Vijver, M.G.; Peijnenburg, W.J.G.M.; Hobbelen, P.H.F.; Koolhaas, J.E.; van Gestel, C.A.M.; van Vliet, P.C.J.; 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. ?? 2006 Elsevier Ltd. All rights reserved.

  1. Field strength prediction for mobile radio with the aid of a topographic data bank

    NASA Astrophysics Data System (ADS)

    Lorenz, R. W.

    Okumura's classical study (1968) and numerous measurements in Germany are used to develop a field strength prediction method for mobile radio. A topographic data bank is developed that contains information on the altitude above sea level and the environmental clutter for areas of 100 x 150 sq m. The work is restricted to quasi-smooth terrain, and special attention is paid to the influence of environmental clutter and the range of field strength fluctuations. The prediction errors are indicated and values for the local probabilities are listed for two different kinds of built-up areas, forests and open terrain. Some discrepancies between measured values and the predicted values of the Okumura model are also explained.

  2. Field strength prediction behind lossy dielectric obstacles by using the UTD

    NASA Astrophysics Data System (ADS)

    van Dooren, G. A. J.; Herben, M. H. A. J.

    1993-05-01

    A comparison is made between the measured and theoretically predicted field strength in the shadow region of a lossy dielectric obstacle. The field is measured along a cylindrical arc behind the obstacle at a frequency of 50 GHz. The theoretical model uses the uniform theory of diffraction including corner, edge-to-edge, and edge-to-corner diffraction, heuristically extended to include effects of nonperfect conductivity. The agreement between the measured and theoretically derived results is excellent for both orthogonal polarizations considered. The field behind a lossy block-shaped obstacle proves to be less polarization dependent than behind a perfectly conducting one.

  3. An action-incongruent secondary task modulates prediction accuracy in experienced performers: evidence for motor simulation.

    PubMed

    Mulligan, Desmond; Lohse, Keith R; Hodges, Nicola J

    2016-07-01

    We provide behavioral evidence that the human motor system is involved in the perceptual decision processes of skilled performers, directly linking prediction accuracy to the (in)ability of the motor system to activate in a response-specific way. Experienced and non-experienced dart players were asked to predict, from temporally occluded video sequences, the landing position of a dart thrown previously by themselves (self) or another (other). This prediction task was performed while additionally performing (a) an action-incongruent secondary motor task (right arm force production), (b) a congruent secondary motor task (mimicking) or (c) an attention-matched task (tone-monitoring). Non-experienced dart players were not affected by any of the secondary task manipulations, relative to control conditions, yet prediction accuracy decreased for the experienced players when additionally performing the force-production, motor task. This interference effect was present for 'self' as well as 'other' decisions, reducing the accuracy of experienced participants to a novice level. The mimicking (congruent) secondary task condition did not interfere with (or facilitate) prediction accuracy for either group. We conclude that visual-motor experience moderates the process of decision making, such that a seemingly visual-cognitive prediction task relies on activation of the motor system for experienced performers. This fits with a motor simulation account of action prediction in sports and other tasks, and alerts to the specificity of these simulative processes. PMID:26021748

  4. Performance and reliability of empirical mobility relationships for the prediction of Debris Flow inundated areas

    NASA Astrophysics Data System (ADS)

    Simoni, Alessandro; Berti, Matteo; Mammoliti, Maria

    2010-05-01

    Empirical mobility relationships can be used for preliminary DF Hazard assessment. An adaptation of the original relationships has been proposed for alpine debris flows (DFLOWZ model; Berti and Simoni, 2007). Once a reference debris flow volume is chosen, the code DFLOWZ allows to estimate the area potentially affected by the event based on the mutual relationships between channel cross-sectional area, planimetric area of the deposit and overall volume. We back-analyzed 25 DF events occurred in the Bolzano province (Italy), ranging in volume from 3,000 to 300,000 m3 and evalutated the performance of the automated method through an objective reliability index. Our aim is: - evaluate the effects of uncertainty associated with the empirical mobility relationships; - assess other possible sources of error or violations of the assumptions that underlie the model. Results indicate that a high-resolution DEM (≤ 2.5 m) is essential to get a reliable inundation prediction over a fan. The code itself performs well, in a wide range of situations, demonstrating the conceptual correctness of underlying assumptions. The most relevant source of error remains the uncertainty associated with the empirical mobility relationships, due mainly to errors in volume measurements of DF deposits. Their improvement can be achieved through the collection of high quality field data of DF events.

  5. Sphere: complete laboratory performance and prediction for on-sky first light

    NASA Astrophysics Data System (ADS)

    Sauvage, Jean-François; Beuzit, Jean-Luc; Roelfsema, Ronald; Feldt, Markus; Dohlen, Kjetil; Mouillet, David; Puget, Pascal; Wildi, Francois; Abe, Lyu; Baruffolo, Andrea; Baudoz, Pierre; Bazzon, Andreas; Boccaletti, Anthony; Buey, Tristan; Carbillet, Marcel; Charton, Julien; Claudi, Riccardo; Costille, Anne; Delboulbé, Alain; Desidera, Silvano; Dominik, Carsten; Downing, Mark; Fabron, Christophe; Feautrier, Philippe; Fedrigo, Enrico; Fusco, Thierry; Giro, Enrico; Gluck, Laurence; Gratton, Raffaele; Henning, Thomas; Hubin, Norbert; Kasper, Markus; Lagrange, Anne-Marie; Langlois, Maud; Le Mignant, David; Lizon, Jean-Louis; Madec, Fabrice; Magnard, Yves; Martinez, Patrice; Mesa, Dino; Möller-Nilsson, Ole; Moulin, Thibaut; Moutou, Claire; Pavlov, Alexey; Perret, Denis; Petit, Cyril; Pragt, Johan; Rabou, Patrick; Rochat, Sylvain; Salasnich, Bernardo; Rousset, Gérard; Schmid, Hans-Martin; Sevin, Arnaud; Soenke, Christian; Stadler, Eric; Suarez, Marcos; Turatto, Massimo; Udry, Stéphane; Vigan, Arthur; Vakili, Farrokh; Zins, Gérard; Zurlo, Alice

    2013-09-01

    Direct imaging of exoplanet is one of the most exciting field of planetology today. The light coming from exoplanet orbiting their host star witnesses for the chemical composition of the atmosphere, and the potential biomarkers for life. However, the faint flux to be imaged, very close to the huge flux of the parent star, makes this kind of observation extremely difficult to perform from the ground. The direct imaging instruments (SPHERE [1], GPI [2]) are nowaday reaching lab maturity. Such instrument imply the coordination of XAO for atmospherical turbulence real-time correction, coronagraphy for star light extinction, IR Dual band camera, IFS, and visible polarimetry. The imaging modes include single and double difference (spectral and angular). The SPHERE project is now at the end of AIT phase. This paper presents the very last results obtained in laboratory, with realistic working conditions. These AIT results allows one to predict on-sky performance, that should come within the next weeks after re-installation at Very Large Telescope at Paranal.

  6. The Validity of Conscientiousness Is Overestimated in the Prediction of Job Performance

    PubMed Central

    2015-01-01

    Introduction Sensitivity analyses refer to investigations of the degree to which the results of a meta-analysis remain stable when conditions of the data or the analysis change. To the extent that results remain stable, one can refer to them as robust. Sensitivity analyses are rarely conducted in the organizational science literature. Despite conscientiousness being a valued predictor in employment selection, sensitivity analyses have not been conducted with respect to meta-analytic estimates of the correlation (i.e., validity) between conscientiousness and job performance. Methods To address this deficiency, we reanalyzed the largest collection of conscientiousness validity data in the personnel selection literature and conducted a variety of sensitivity analyses. Results Publication bias analyses demonstrated that the validity of conscientiousness is moderately overestimated (by around 30%; a correlation difference of about .06). The misestimation of the validity appears to be due primarily to suppression of small effects sizes in the journal literature. These inflated validity estimates result in an overestimate of the dollar utility of personnel selection by millions of dollars and should be of considerable concern for organizations. Conclusion The fields of management and applied psychology seldom conduct sensitivity analyses. Through the use of sensitivity analyses, this paper documents that the existing literature overestimates the validity of conscientiousness in the prediction of job performance. Our data show that effect sizes from journal articles are largely responsible for this overestimation. PMID:26517553

  7. Assessment of an analytical procedure for predicting supersonic ejector nozzle performance

    NASA Technical Reports Server (NTRS)

    Anderson, B. H.

    1974-01-01

    The ability of analysis to predict ejector nozzle characteristics over a wide range of conditions and to study the relation between design parameters and performance is assessed. The analytical method investigated provided an accurate and economical method for predicting the performance of supersonic ejector nozzles. The factors which had the greatest influence over ejector nozzle behavior were those which influenced the initial expansion and recompression process.

  8. Field-evolved resistance to Bt maize by western corn rootworm: predictions from the laboratory and effects in the field.

    PubMed

    Gassmann, Aaron J

    2012-07-01

    Crops engineered to produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) provide an effective management tool for many key insect pests. However, pest species have repeatedly demonstrated their ability to adapt to management practices. Results from laboratory selection experiments illustrate the capacity of pest species to evolve Bt resistance. Furthermore, resistance has been documented to Bt sprays in the field and greenhouse, and more recently, by some pests to Bt crops in the field. In 2009, fields were discovered in Iowa (USA) with populations of western corn rootworm, Diabrotica virgifera virgifera LeConte, that had evolved resistance to maize that produces the Bt toxin Cry3Bb1. Fields with resistant insects in 2009 had been planted to Cry3Bb1 maize for at least three consecutive years and as many as 6years. Computer simulation models predicted that the western corn rootworm might evolve resistance to Bt maize in as few as 3years. Laboratory and field data for interactions between western corn rootworm and Bt maize indicate that currently commercialized products are not high-dose events, which increases the risk of resistance evolution because non-recessive resistance traits may enhance survival on Bt maize. Furthermore, genetic analysis of laboratory strains of western corn rootworm has found non-recessive inheritance of resistance. Field studies conducted in two fields identified as harboring Cry3Bb1-resistant western corn rootworm found that survival of western corn rootworm did not differ between Cry3Bb1 maize and non-Bt maize and that root injury to Cry3Bb1 maize was higher than injury to other types of Bt maize or to maize roots protected with a soil insecticide. These first cases of field-evolved resistance to Bt maize by western corn rootworm provide an early warning and point to the need to apply better integrated pest management practices when using Bt maize to manage western corn rootworm. PMID:22537837

  9. Mathematical formulation to predict the harmonics of the superconducting Large Hadron Collider magnets. II. Dynamic field changes and scaling laws

    NASA Astrophysics Data System (ADS)

    Sammut, Nicholas J.; Bottura, Luca; Bauer, Pierre; Velev, George; Pieloni, Tatiana; Micallef, Joseph

    2007-08-01

    A superconducting particle accelerator like the LHC (Large Hadron Collider) at CERN, can only be controlled well if the effects of the magnetic field multipoles on the beam are compensated. The demands on a control system solely based on beam feedback may be too high for the requirements to be reached at the specified bandwidth and accuracy. Therefore, we designed a suitable field description for the LHC (FIDEL) as part of the machine control baseline to act as a feed-forward magnetic field prediction system. FIDEL consists of a physical and empirical parametric field model based on magnetic measurements at warm and in cryogenic conditions. The performance of FIDEL is particularly critical at injection when the field decays, and in the initial part of the acceleration when the field snaps back. These dynamic components are both current and time dependent and are not reproducible from cycle to cycle since they also depend on the magnet powering history. In this paper a qualitative and quantitative description of the dynamic field behavior substantiated by a set of scaling laws is presented.

  10. Prediction of circulation control performance characteristics for Super STOL and STOL applications

    NASA Astrophysics Data System (ADS)

    Naqvi, Messam Abbas

    due to the lack of a simple prediction capability. This research effort was focused on the creation of a rapid prediction capability of Circulation Control Aerodynamic Characteristics which could help designers with rapid performance estimates for design space exploration. A morphological matrix was created with the available set of options which could be chosen to create this prediction capability starting with purely analytical physics based modeling to high fidelity CFD codes. Based on the available constraints, and desired accuracy meta-models have been created around the two dimensional circulation control performance results computed using Navier Stokes Equations (Computational Fluid Dynamics). DSS2, a two dimensional RANS code written by Professor Lakshmi Sankar was utilized for circulation control airfoil characteristics. The CFD code was first applied to the NCCR 1510-7607N airfoil to validate the model with available experimental results. It was then applied to compute the results of a fractional factorial design of experiments array. Metamodels were formulated using the neural networks to the results obtained from the Design of Experiments. Additional validation runs were performed to validate the model predictions. Metamodels are not only capable of rapid performance prediction, but also help generate the relation trends of response matrices with control variables and capture the complex interactions between control variables. Quantitative as well as qualitative assessments of results were performed by computation of aerodynamic forces & moments and flow field visualizations. Wing characteristics in three dimensions were obtained by integration over the whole wing using Prandtl's Wing Theory. The baseline Super STOL configuration [3] was then analyzed with the application of circulation control technology. The desired values of lift and drag to achieve the target values of Takeoff & Landing performance were compared with the optimal configurations obtained

  11. Predicting space telerobotic operator training performance from human spatial ability assessment

    NASA Astrophysics Data System (ADS)

    Liu, Andrew M.; Oman, Charles M.; Galvan, Raquel; Natapoff, Alan

    2013-11-01

    Our goal was to determine whether existing tests of spatial ability can predict an astronaut's qualification test performance after robotic training. Because training astronauts to be qualified robotics operators is so long and expensive, NASA is interested in tools that can predict robotics performance before training begins. Currently, the Astronaut Office does not have a validated tool to predict robotics ability as part of its astronaut selection or training process. Commonly used tests of human spatial ability may provide such a tool to predict robotics ability. We tested the spatial ability of 50 active astronauts who had completed at least one robotics training course, then used logistic regression models to analyze the correlation between spatial ability test scores and the astronauts' performance in their evaluation test at the end of the training course. The fit of the logistic function to our data is statistically significant for several spatial tests. However, the prediction performance of the logistic model depends on the criterion threshold assumed. To clarify the critical selection issues, we show how the probability of correct classification vs. misclassification varies as a function of the mental rotation test criterion level. Since the costs of misclassification are low, the logistic models of spatial ability and robotic performance are reliable enough only to be used to customize regular and remedial training. We suggest several changes in tracking performance throughout robotics training that could improve the range and reliability of predictive models.

  12. CFD predictions of near-field pressure signatures of a low-boom aircraft

    NASA Technical Reports Server (NTRS)

    Fouladi, Kamran; Baize, Daniel G.

    1992-01-01

    A three dimensional Euler marching code has been utilized to predict near-field pressure signatures of an aircraft with low boom characteristics. Computations were extended to approximately six body lengths aft of the aircraft in order to obtain pressure data at three body lengths below the aircraft for a cruise Mach number of 1.6. The near-field pressure data were extrapolated to the ground using a Whitham based method. The distance below the aircraft where the pressure data are attained is defined in this paper as the 'separation distance.' The influences of separation distances and the still highly three-dimensional flow field on the predicted ground pressure signatures and boom loudness are presented in this paper.

  13. HIGH RESOLUTION PREDICTION OF GAS INJECTION PROCESS PERFORMANCE FOR HETEROGENEOUS RESERVOIRS

    SciTech Connect

    Thomas A. Hewett; Franklin M. Orr Jr.

    2000-12-31

    Gas injection in oil reservoirs offers huge potential for improved oil recovery. However, successful design of a gas injection process requires a detailed understanding of a variety of different significant processes, including the phase behavior of multicomponent mixtures and the approach to multi-contact miscibility in the reservoir, the flow of oil, water and gas underground, and the interaction of phase behavior reservoir heterogeneity and gravity on overall performance at the field scale. This project attempts to tackle all these issues using a combination of theoretical, numerical and laboratory studies of gas injection. The aim of this work is to develop a set of ultra-fast compositional simulation tools that can be used to make field-scale predictions of the performance of gas injection processes. To achieve the necessary accuracy, these tools must satisfy the fundamental physics and chemistry of the displacement from the pore to the reservoir scales. Thus this project focuses on four main research areas: (1) determination of the most appropriate methods of mapping multicomponent solutions to streamlines and streamtubes in 3D; (2) development of techniques for automatic generation of analytical solutions for one-dimensional flow along a streamline; (3) experimental investigations to improve the representation of physical mechanisms that govern displacement efficiency along a streamline; and (4) Theoretical and experimental investigations to establish the limitations of the streamline/streamtube approach. In this report they briefly review the status of the research effort in each area. They then give a more in depth discussion of the development of a CT scanning technique which can measure compositions in a two-phase, three-component system in-situ.

  14. Measurements of High-Contrast Starshade Performance in the Field

    NASA Astrophysics Data System (ADS)

    Smith, Daniel; Glassman, Tiffany M.; Warwick, Steve; Novicki, Megan; Richards, Michael; Patterson, Keith; Harness, Anthony

    2016-01-01

    The external Starshade is a method for the direct detection and spectral characterization of terrestrial planets around other stars, a key goal identified in ASTRO2010. In an effort to validate the starlight-suppression performance of the Starshade, we have measured contrast better than 1X10-9 using 60 cm Starshades at points just beyond the Starshade tips. These measurements were made over a 50% spectral bandpass, using an incoherent light source (a white LED), and in challenging outdoor test environments. Our experimental setup is designed to provide Starshade to telescope separation and telescope aperture size that are scaled as closely as possible to the flight system. The measurements confirm not only the overall starlight-suppression capability of the Starshade concept but also the robustness of the setup to optical disturbances such as atmospheric effects at the test site. The spectral coverage is limited only by the optics and detectors in our test setup, not by the Starshade itself. Here we describe our latest results as well as detailed comparisons of the measured results to model predictions. Plans and status of the next phase of ground testing are also discussed.

  15. The effects of magnetic field in plume region on the performance of multi-cusped field thruster

    SciTech Connect

    Hu, Peng Liu, Hui Yu, Daren; Gao, Yuanyuan; Mao, Wei

    2015-10-15

    The performance characteristics of a Multi-cusped Field Thruster depending on the magnetic field in the plume region were investigated. Five magnetic field shielding rings were separately mounted near the exit of discharge channel to decrease the strength of magnetic field in the plume region in different levels, while the magnetic field in the upstream was well maintained. The test results show that the electron current increases with the decrease of magnetic field strength in the plume region, which gives rise to higher propellant utilization and lower current utilization. On the other hand, the stronger magnetic field in the plume region improves the performance at low voltages (high current mode) while lower magnetic field improves the performance at high voltages (low current mode). This work can provide some optimal design ideas of the magnetic strength in the plume region to improve the performance of thruster.

  16. Predicted performance of a 10.6 micron pulsed coherent laser radar

    NASA Astrophysics Data System (ADS)

    Harrison, Kenneth W.

    1987-01-01

    Theoretical predictions are made for the S/N ratio effects of atmospheric turbulence, target features, and receiver configuration on the performance of a 10.6-micron pulsed coherent laser radar. The predictions obtained are compared with experimental data for two target types: terrain consisting of soil and trees, and a silage tower. It is predicted that the terrain target should be detectable with a 50-mm aperture at ranges of up to 2.5 km for 50 percent of the time; this performance has been achieved in practice.

  17. Improvement in the prediction of solar wind conditions using near-real time solar magnetic field updates

    NASA Astrophysics Data System (ADS)

    Arge, C. N.; Pizzo, V. J.

    2000-05-01

    The Wang-Sheeley model is an empirical model that can predict the background solar wind speed and interplanetary magnetic field (IMF) polarity. We make a number of modifications to the basic technique that greatly improve the performance and reliability of the model. First, we establish a continuous empirical function that relates magnetic expansion factor to solar wind velocity at the source surface. Second, we propagate the wind from the source surface to the Earth using the assumption of radial streams and a simple scheme to account for their interactions. Third, we develop and apply a method for identifying and removing problematic magnetograms from the Wilcox Solar Observatory (WSO). Fourth, we correct WSO line-of-sight magnetograms for polar field strength modulation effects that result from the annual variation in the solar b angle. Fifth, we explore a number of techniques to optimize construction of daily updated synoptic maps from the WSO magnetograms. We report on a comprehensive statistical analysis comparing Wang-Sheeley model predictions with the WIND satellite data set during a 3-year period centered about the May 1996 solar minimum. The predicted and observed solar wind speeds have a statistically significant correlation (~0.4) and an average fractional deviation of 0.15. When a single (6-month) period with large data gaps is excluded from the comparison, the solar wind speed is correctly predicted to within 10-15%. The IMF polarity is correctly predicted ~75% of the time. The solar wind prediction technique presented here has direct applications to space weather research and forecasting.

  18. Predicting law enforcement officer job performance with the Personality Assessment Inventory.

    PubMed

    Lowmaster, Sara E; Morey, Leslie C

    2012-01-01

    This study examined the descriptive and predictive characteristics of the Personality Assessment Inventory (PAI; Morey, 1991) in a sample of 85 law enforcement officer candidates. Descriptive results indicate that mean PAI full-scale and subscale scores are consistently lower than normative community sample scores, with some exceptions noted typically associated with defensive responding. Predictive validity was examined by relating PAI full-scale and subscale scores to supervisor ratings in the areas of job performance, integrity problems, and abuse of disability status. Modest correlations were observed for all domains; however, predictive validity was moderated by defensive response style, with greater predictive validity observed among less defensive responders. These results suggest that the PAI's full scales and subscales are able to predict law enforcement officers' performance, but their utility is appreciably improved when taken in the context of indicators of defensive responding. PMID:22224672

  19. Full-field dynamic strain prediction on a wind turbine using displacements of optical targets measured by stereophotogrammetry

    NASA Astrophysics Data System (ADS)

    Baqersad, Javad; Niezrecki, Christopher; Avitabile, Peter

    2015-10-01

    Health monitoring of rotating structures (e.g. wind turbines and helicopter blades) has historically been a challenge due to sensing and data transmission problems. Unfortunately mechanical failure in many structures initiates at components on or inside the structure where there is no sensor located to predict the failure. In this paper, a wind turbine was mounted with a semi-built-in configuration and was excited using a mechanical shaker. A series of optical targets was distributed along the blades and the fixture and the displacement of those targets during excitation was measured using a pair of high speed cameras. Measured displacements with three dimensional point tracking were transformed to all finite element degrees of freedom using a modal expansion algorithm. The expanded displacements were applied to the finite element model to predict the full-field dynamic strain on the surface of the structure as well as within the interior points. To validate the methodology of dynamic strain prediction, the predicted strain was compared to measured strain by using six mounted strain-gages. To verify if a simpler model of the turbine can be used for the expansion, the expansion process was performed both by using the modes of the entire turbine and modes of a single cantilever blade. The results indicate that the expansion approach can accurately predict the strain throughout the turbine blades from displacements measured by using stereophotogrammetry.

  20. Predictive uncertainty analysis of a highly heterogeneous field-scale groundwater model using null-space Monte Carlo

    NASA Astrophysics Data System (ADS)

    Hart, D.; Yoon, H.; McKenna, S. A.

    2011-12-01

    Quantification of prediction uncertainty resulting from estimated parameters is critical to provide accurate predictive models for field-scale groundwater flow and transport problems. We examine and compare two approaches to defining predictive uncertainty where both approaches utilize pilot points to parameterize spatially heterogeneous fields. The first approach is the independent calibration of multiple initial "seed" fields created through geostatistical simulation and conditioned to observation data, resulting in an ensemble of calibrated property fields that defines uncertainty in the calibrated parameters. The second approach is the null-space Monte Carlo (NSMC) method that employs a decomposition of the Jacobian matrix from a single calibration to define a minimum number of linear combinations of parameters that account for the majority of the sensitivity of the overall calibration to the observed data. Random vectors are applied to the remaining linear combinations of parameters, the null space, to create an ensemble of fields, each of which remains calibrated to the data. We compare these two approaches using a highly-parameterized groundwater model of the Culebra dolomite in southeastern New Mexico. Observation data include two decades of steady-state head measurements and pumping test results. The predictive performance measure is advective travel time from a point to a prescribed boundary. Calibrated parameters at a set of pilot points include transmissivity, the horizontal hydraulic anisotropy, the storativity, and a section of recharge (> 1200 parameters in total). First, we calibrate 200 multiple random seed fields generated through geostatistical simulation conditioned to observation data. The 11 fields that contain the best and worst scenarios in terms of calibration and travel time analysis among the best 100 calibrated results provide a basis for the NSMC method. The NSMC method is used to generate 200 calibration-constrained parameter fields

  1. Individual differences in autistic trait load in the general population predict visual working memory performance.

    PubMed

    Richmond, Lauren L; Thorpe, Melissa; Berryhill, Marian E; Klugman, Joshua; Olson, Ingrid R

    2013-06-01

    Prior studies have reported instances of both intact and impaired working memory (WM) performance in people with autism spectrum disorder (ASD). In order to investigate the relation between autistic traits that extend into the normal population and WM, 104 normal college-aged students who varied in their levels of autistic traits were tested. The loading of ASD-associated traits in the normal population leads to differing predictions about WM performance. ASD traits related to a local processing style (or "attention to detail") might enhance WM while ASD-associated traits related to difficulty switching attention and reorienting focus (or "social interaction") might impair WM performance. To assess these predictions, participants filled out the Autism Spectrum Quotient (AQ) and performed a working memory task with both visual and verbal variants. AQ scores were then broken into "attention to detail" and "social interaction" factors, as proposed by Hoekstra and colleagues. The results showed that AQ scores did not predict verbal WM performance but they did predict visual WM performance. The social interaction and attention to detail factors of the AQ had opposing relationships with visual WM performance: A higher level of social difficulty was associated with significantly poorer visual WM performance while a higher level of attention to detail was associated with enhanced visual WM performance. Further investigation of the relation between AQ and WM using the original five-factor model proposed by Baron-Cohen and colleagues (2001) revealed an association between impoverished imagination and visual WM overall. PMID:23121303

  2. A study of methods which predict supersonic flow fields from body geometry, distance, and Mach number

    NASA Technical Reports Server (NTRS)

    Mack, R. J.

    1973-01-01

    A study of seven methods for predicting flow-field pressure signatures from the parameters Mach number, body geometry, and field-path distance has been made. The methods included the method of characteristics, which served as a standard of comparison; a shock-capturing method; three Whitham theory methods; a modified characteristics method; and a bicharacteristics method. Results from each method were also compared with recently obtained wind-tunnel data for a cone-cylinder model at Mach numbers of 2.96 and 4.63 with ratios of radial distance to cone length of 2 and 5. The comparisons at a Mach number of 2.96 showed that signatures from all the methods correlated well with wind-tunnel data and with the signatures predicted by the method of characteristics. At a Mach number of 4.63, however, the agreement between the signatures obtained in the wind tunnel and those predicted by theory varied from good to poor, as did the agreement between the signatures obtained by the method of characteristics and the other six methods. It should be noted that these results and comparisons indicate pressure prediction capabilities only for the near-field flow about bodies of revolution.

  3. BNL PREDICTION OF NUPECS FIELD MODEL TESTS OF NPP STRUCTURES SUBJECT TO SMALL TO MODERATE MAGNITUDE EARTHQUAKES.

    SciTech Connect

    XU,J.; COSTANTINO,C.; HOFMAYER,C.; MURPHY,A.; KITADA,Y.

    2003-08-17

    As part of a verification test program for seismic analysis codes for NPP structures, the Nuclear Power Engineering Corporation (NUPEC) of Japan has conducted a series of field model test programs to ensure the adequacy of methodologies employed for seismic analyses of NPP structures. A collaborative program between the United States and Japan was developed to study seismic issues related to NPP applications. The US Nuclear Regulatory Commission (NRC) and its contractor, Brookhaven National Laboratory (BNL), are participating in this program to apply common analysis procedures to predict both free field and soil-structure Interaction (SSI) responses to recorded earthquake events, including embedment and dynamic cross interaction (DCI) effects. This paper describes the BNL effort to predict seismic responses of the large-scale realistic model structures for reactor and turbine buildings at the NUPEC test facility in northern Japan. The NUPEC test program has collected a large amount of recorded earthquake response data (both free-field and in-structure) from these test model structures. The BNL free-field analyses were performed with the CARES program while the SSI analyses were preformed using the SASS12000 computer code. The BNL analysis includes both embedded and excavated conditions, as well as the DCI effect, The BNL analysis results and their comparisons to the NUPEC recorded responses are presented in the paper.

  4. BNL PREDICTION OF NUPECS FIELD MODEL TESTS OF NPP STRUCTURES SUBJECT TO SMALL TO MODERATE MAGNITUDE EARTHQUAKES.

    SciTech Connect

    XU,J.; COSTANTINO,C.; HOFMAYER,C.; MURPHY,A.; KITADA,Y.

    2003-08-17

    As part of a verification test program for seismic analysis codes for NPP structures, the Nuclear Power Engineering Corporation (NUPEC) of Japan has conducted a series of field model test programs to ensure the adequacy of methodologies employed for seismic analyses of NPP structures. A collaborative program between the United States and Japan was developed to study seismic issues related to NPP applications. The US Nuclear Regulatory Commission (NRC) and its contractor, Brookhaven National Laboratory (BNL), are participating in this program to apply common analysis procedures to predict both free field and soil-structure interaction (SSI) responses to recorded earthquake events, including embedment and dynamic cross interaction (DCI) effects. This paper describes the BNL effort to predict seismic responses of the large-scale realistic model structures for reactor and turbine buildings at the NUPEC test facility in northern Japan. The NUPEC test program has collected a large amount of recorded earthquake response data (both free-field and in-structure) from these test model structures. The BNL free-field analyses were performed with the CARES program while the SSI analyses were preformed using the SASS12000 computer code. The BNL analysis includes both embedded and excavated conditions, as well as the DCI effect, The BNL analysis results and their comparisons to the NUPEC recorded responses are presented in the paper.

  5. Performance predictions for mechanical excavators in Yucca Mountain tuffs; Yucca Mountain Site Characterization Project

    SciTech Connect

    Ozdemir, L.; Gertsch, L.; Neil, D.; Friant, J.

    1992-09-01

    The performances of several mechanical excavators are predicted for use in the tuffs at Yucca Mountain: Tunnel boring machines, the Mobile Miner, a roadheader, a blind shaft borer, a vertical wheel shaft boring machine, raise drills, and V-Moles. Work summarized is comprised of three parts: Initial prediction using existing rock physical property information; Measurement of additional rock physical properties; and Revision of the initial predictions using the enhanced database. The performance predictions are based on theoretical and empirical relationships between rock properties and the forces-experienced by rock cutters and bits during excavation. Machine backup systems and excavation design aspects, such as curves and grades, are considered in determining excavator utilization factors. Instanteous penetration rate, advance rate, and cutter costs are the fundamental performance indicators.

  6. An Empirical Method for Fast Prediction of Rarefied Flow Field around a Vertical Plate

    NASA Astrophysics Data System (ADS)

    He, Tao; Wang, Jiang-Feng

    2016-06-01

    Numerical study is conducted to investigate the effects of free-stream Knudsen (Kn) number on rarefied flow field around a vertical plate employing an unstructured DSMC method, and an empirical method for fast prediction of flow-field structure at different Kn numbers in a given inflow velocity is proposed. First, the flow at a velocity 7500m/s is simulated using a perfect-gas model with free-stream Kn changing from 0.035 to 13.36. The flow-field characteristics in these cases with varying Kn numbers are analyzed and a linear-expansion phenomenon as a function of the square of Kn is discovered. An empirical method is proposed for fast flow-field prediction at different Kn based on the least-square-fitting method. Further, the effects of chemical reactions on flow field are investigated to verify the applicability of the empirical method in the real gas conditions. Three of the cases in perfect-gas flow are simulated again by introducing five-species air chemical module. The flow properties with and without chemical reactions are compared. In the end, the variation of chemical-reaction flow field as a function of Kn is analyzed and it is shown that the empirical method are also suitable when considering chemical reactions.

  7. Variability of the ocean-induced magnetic field predicted at sea surface and at satellite altitudes

    NASA Technical Reports Server (NTRS)

    Glazman, Roman E.; Golubev, Yury N.

    2005-01-01

    Spatial and temporal variability of the magnetic field component induced by ocean circulation is investigated on the basis of a standard thin-shell approximation of electro- and magneto-static equations. Well-known difficulties of numerical solution of the governing equations are resolved by reducing the problem to an equation for the electric field potential,(ef) as opposed to a more conventional approach focused on the vertical jump, (psi), of the magnetic field potential across a combined ocean/ marine-sediment-layer spherical shell. The present formulation permits using more realistic input data on ocean currents and ultimately yields much greater (by at least an order of magnitude) values of the magnetic field at sea surface than predicted in earlier studies. Such large values are comparable to, and in some cases exceed, magnetic field variations caused by lithospheric and ionospheric sources on monthly to interannual timescales. At the 400-km altitude (of CHAMP satellite), the field attains 6 nT. The model predictions show favorable comparisons with some in situ measurements as well as with Challenging Minisatellite Payload (CHAMP) satellite magnetometer data.

  8. Visual Attention Measures Predict Pedestrian Detection in Central Field Loss: A Pilot Study

    PubMed Central

    Alberti, Concetta F.; Horowitz, Todd; Bronstad, P. Matthew; Bowers, Alex R.

    2014-01-01

    Purpose The ability of visually impaired people to deploy attention effectively to maximize use of their residual vision in dynamic situations is fundamental to safe mobility. We conducted a pilot study to evaluate whether tests of dynamic attention (multiple object tracking; MOT) and static attention (Useful Field of View; UFOV) were predictive of the ability of people with central field loss (CFL) to detect pedestrian hazards in simulated driving. Methods 11 people with bilateral CFL (visual acuity 20/30-20/200) and 11 age-similar normally-sighted drivers participated. Dynamic and static attention were evaluated with brief, computer-based MOT and UFOV tasks, respectively. Dependent variables were the log speed threshold for 60% correct identification of targets (MOT) and the increase in the presentation duration for 75% correct identification of a central target when a concurrent peripheral task was added (UFOV divided and selective attention subtests). Participants drove in a simulator and pressed the horn whenever they detected pedestrians that walked or ran toward the road. The dependent variable was the proportion of timely reactions (could have stopped in time to avoid a collision). Results UFOV and MOT performance of CFL participants was poorer than that of controls, and the proportion of timely reactions was also lower (worse) (84% and 97%, respectively; p = 0.001). For CFL participants, higher proportions of timely reactions correlated significantly with higher (better) MOT speed thresholds (r = 0.73, p = 0.01), with better performance on the UFOV divided and selective attention subtests (r = −0.66 and −0.62, respectively, p<0.04), with better contrast sensitivity scores (r = 0.54, p = 0.08) and smaller scotomas (r = −0.60, p = 0.05). Conclusions Our results suggest that brief laboratory-based tests of visual attention may provide useful measures of functional visual ability of individuals with CFL relevant to more

  9. Individual and population pharmacokinetic compartment analysis: a graphic procedure for quantification of predictive performance

    PubMed Central

    Eksborg, Staffan

    2013-01-01

    Objectives Pharmacokinetic studies are important for optimizing of drug dosing, but requires proper validation of the used pharmacokinetic procedures. However, simple and reliable statistical methods suitable for evaluation of the predictive performance of pharmacokinetic analysis are essentially lacking. The aim of the present study was to construct and evaluate a graphic procedure for quantification of predictive performance of individual and population pharmacokinetic compartment analysis. Methods Original data from previously published pharmacokinetic compartment analyses after intravenous, oral, and epidural administration, and digitized data, obtained from published scatter plots of observed vs predicted drug concentrations from population pharmacokinetic studies using the NPEM algorithm and NONMEM computer program and Bayesian forecasting procedures, were used for estimating the predictive performance according to the proposed graphical method and by the method of Sheiner and Beal. Results The graphical plot proposed in the present paper proved to be a useful tool for evaluation of predictive performance of both individual and population compartment pharmacokinetic analysis. Conclusion The proposed method is simple to use and gives valuable information concerning time- and concentration-dependent inaccuracies that might occur in individual and population pharmacokinetic compartment analysis. Predictive performance can be quantified by the fraction of concentration ratios within arbitrarily specified ranges, e.g. within the range 0.8–1.2.

  10. Risk Prediction Modeling of Sequencing Data Using a Forward Random Field Method

    PubMed Central

    Wen, Yalu; He, Zihuai; Li, Ming; Lu, Qing

    2016-01-01

    With the advance in high-throughput sequencing technology, it is feasible to investigate the role of common and rare variants in disease risk prediction. While the new technology holds great promise to improve disease prediction, the massive amount of data and low frequency of rare variants pose great analytical challenges on risk prediction modeling. In this paper, we develop a forward random field method (FRF) for risk prediction modeling using sequencing data. In FRF, subjects’ phenotypes are treated as stochastic realizations of a random field on a genetic space formed by subjects’ genotypes, and an individual’s phenotype can be predicted by adjacent subjects with similar genotypes. The FRF method allows for multiple similarity measures and candidate genes in the model, and adaptively chooses the optimal similarity measure and disease-associated genes to reflect the underlying disease model. It also avoids the specification of the threshold of rare variants and allows for different directions and magnitudes of genetic effects. Through simulations, we demonstrate the FRF method attains higher or comparable accuracy over commonly used support vector machine based methods under various disease models. We further illustrate the FRF method with an application to the sequencing data obtained from the Dallas Heart Study. PMID:26892725

  11. Prediction of intrinsic motivation and sports performance using 2 x 2 achievement goal framework.

    PubMed

    Li, Chiung-Huang; Chi, Likang; Yeh, Suh-Ruu; Guo, Kwei-Bin; Ou, Cheng-Tsung; Kao, Chun-Chieh

    2011-04-01

    The purpose of this study was to examine the influence of 2 x 2 achievement goals on intrinsic motivation and performance in handball. Participants were 164 high school athletes. All completed the 2 x 2 Achievement Goals Questionnaire for Sport and the Intrinsic Motivation subscale of the Sport Motivation Scale; the coach for each team rated his athletes' overall sports performance. Using simultaneous-regression analyses, mastery-approach goals positively predicted both intrinsic motivation and performance in sports, whereas performance-avoidance goals negatively predicted sports performance. These results suggest that athletes who pursue task mastery and improvement of their competence perform well and enjoy their participation. In contrast, those who focus on avoiding normative incompetence perform poorly. PMID:21675576

  12. Predicting the Electric Field Distribution in the Brain for the Treatment of Glioblastoma

    PubMed Central

    Miranda, Pedro C.; Mekonnen, Abeye; Salvador, Ricardo; Basser, Peter J.

    2014-01-01

    The use of alternating electric fields has been recently proposed for the treatment of recurrent glioblastoma. In order to predict the electric field distribution in the brain during the application of such tumor treating fields (TTF), we constructed a realistic head model from MRI data and placed transducer arrays on the scalp to mimic an FDA-approved medical device. Values for the tissue dielectric properties were taken from the literature; values for the device parameters were obtained from the manufacturer. The finite element method was used to calculate the electric field distribution in the brain. We also included a “virtual lesion” in the model to simulate the presence of an idealized tumor. The calculated electric field in the brain varied mostly between 0.5 and 2.0 V/cm and exceeded 1.0 V/cm in 60% of the total brain volume. Regions of local field enhancement occurred near interfaces between tissues with different conductivities wherever the electric field was perpendicular to those interfaces. These increases were strongest near the ventricles but were also present outside the tumor’s necrotic core and in some parts of the gray matter-white matter interface. The electric field values predicted in this model brain are in reasonably good agreement with those that have been shown to reduce cancer cell proliferation in vitro. The electric field distribution is highly non-uniform and depends on tissue geometry and dielectric properties. This could explain some of the variability in treatment outcomes. The proposed modeling framework could be used to better understand the physical basis of TTF efficacy through retrospective analysis and to improve TTF treatment planning. PMID:25003941

  13. Utility of Microcosm Studies for Predicting Phylloplane Bacterium Population Sizes in the Field

    PubMed Central

    Kinkel, L. L.; Wilson, M.; Lindow, S. E.

    1996-01-01

    Population sizes of two ice nucleation-active strains of Pseudomonas syringae were compared on leaves in controlled environments and in the field to determine the ability of microcosm studies to predict plant habitat preferences in the field. The P. syringae strains investigated were the parental strains of recombinant deletion mutant strains deficient in ice nucleation activity that had been field tested for their ability to control plant frost injury. The population size of the P. syringae strains was measured after inoculation at three field locations on up to 40 of the same plant species that were studied in the growth chamber. There was seldom a significant relationship between the mean population size of a given P. syringae strain incubated under either wet or dry conditions in microcosms and the mean population size which could be recovered from the same species when inoculated in the field. Specifically, on some plant species, the population size recovered from leaves in the field was substantially greater than from that species in a controlled environment, while for other plant species field populations were significantly smaller than those observed under controlled conditions. Population sizes of inoculated P. syringae strains, however, were frequently highly positively correlated with the indigenous bacterial population size on the same plant species in the field, suggesting that the ability of a particular plant species to support introduced bacterial strains is correlated with its ability to support large bacterial populations or that indigenous bacteria enhance the survival of introduced strains. Microcosm studies therefore seem most effective at assessing possible differences between parental and recombinant strains under a given environmental regime but are limited in their ability to predict the specific population sizes or plant habitat preferences of bacteria on leaves under field conditions. PMID:16535405

  14. Predicting the electric field distribution in the brain for the treatment of glioblastoma

    NASA Astrophysics Data System (ADS)

    Miranda, Pedro C.; Mekonnen, Abeye; Salvador, Ricardo; Basser, Peter J.

    2014-08-01

    The use of alternating electric fields has been recently proposed for the treatment of recurrent glioblastoma. In order to predict the electric field distribution in the brain during the application of such tumor treating fields (TTF), we constructed a realistic head model from MRI data and placed transducer arrays on the scalp to mimic an FDA-approved medical device. Values for the tissue dielectric properties were taken from the literature; values for the device parameters were obtained from the manufacturer. The finite element method was used to calculate the electric field distribution in the brain. We also included a ‘virtual lesion’ in the model to simulate the presence of an idealized tumor. The calculated electric field in the brain varied mostly between 0.5 and 2.0 V cm - 1 and exceeded 1.0 V cm - 1 in 60% of the total brain volume. Regions of local field enhancement occurred near interfaces between tissues with different conductivities wherever the electric field was perpendicular to those interfaces. These increases were strongest near the ventricles but were also present outside the tumor’s necrotic core and in some parts of the gray matter-white matter interface. The electric field values predicted in this model brain are in reasonably good agreement with those that have been shown to reduce cancer cell proliferation in vitro. The electric field distribution is highly non-uniform and depends on tissue geometry and dielectric properties. This could explain some of the variability in treatment outcomes. The proposed modeling framework could be used to better understand the physical basis of TTF efficacy through retrospective analysis and to improve TTF treatment planning.

  15. Predicting characteristics of rainfall driven estrogen runoff and transport from swine AFO spray fields.

    PubMed

    Lee, Boknam; Kullman, Seth W; Yost, Erin E; Meyer, Michael T; Worley-Davis, Lynn; Williams, C Michael; Reckhow, Kenneth H

    2015-11-01

    Animal feeding operations (AFOs) have been implicated as potentially major sources of estrogenic contaminants into the aquatic environment due to the relatively minimal treatment of waste and potential mobilization and transport of waste components from spray fields. In this study a Bayesian network (BN) model was developed to inform management decisions and better predict the transport and fate of natural steroidal estrogens from these sites. The developed BN model integrates processes of surface runoff and sediment loss with the modified universal soil loss equation (MUSLE) and the soil conservation service curve number (SCS-CN) runoff model. What-if scenario simulations of lagoon slurry wastes to the spray fields were conducted for the most abundant natural estrogen estrone (E1) observed in the system. It was found that E1 attenuated significantly after 2 months following waste slurry application in both spring and summer seasons, with the overall attenuation rate predicted to be higher in the summer compared to the spring. Using simulations of rainfall events in conjunction with waste slurry application rates, it was predicted that the magnitude of E1 runoff loss is significantly higher in the spring as compared to the summer months, primarily due to spray field crop management plans. Our what-if scenario analyses suggest that planting Bermuda grass in the spray fields is likely to reduce runoff losses of natural estrogens near the water bodies and ecosystems, as compared to planting of soybeans. PMID:26102057

  16. Ab initio prediction of protein structure with both all-atom and simplified force fields

    NASA Astrophysics Data System (ADS)

    Scheraga, Harold

    2004-03-01

    Using only a physics-based ab initio method, and both all-atom (ECEPP/3) and simplified united-residue (UNRES) force fields, global optimization of both potential functions with Monte Carlo-plus-Minimization (MCM) and Conformational Space Annealing (CSA), respectively, provides predicted structures of proteins without use of knowledge-based information. The all-atom approach has been applied to the 46-residue protein A, and the UNRES approach has been applied to larger CASP targets. The predicted structures will be described.

  17. Predicting the Interplanetary Magnetic Field using Approaches Based on Data Mining and Physical Models

    NASA Astrophysics Data System (ADS)

    Riley, P.; Russell, C. T.; de Koning, C. A.; Biesecker, D. A.; Linker, J.; Owens, M. J.; Lugaz, N.; Martens, P.; Angryk, R.; Reinard, A.; Ulrich, R. K.; Horbury, T. S.; Pizzo, V. J.; Liu, Y.; Hoeksema, T.

    2015-12-01

    An accurate prediction of the interplanetary magnetic field, and, in particular, its z-component (Bz) is a crucial capability for any space weather forecasting system, and yet, thus far, it has remained largely elusive (a point exemplified by the fact that no prediction center currently provides a forecast for Bz). In this presentation, we discuss the various physical processes that can produce non-zero values of Bz and summarize a selection of promising approaches that may ultimately lead to reliable forecasts of Bz. We describe the first steps we have taken to develop a framework for assessing these techniques, and show preliminary results of their efficacy.

  18. Performance of the High Field Fusion Reactor (FIRE) and a Proposed Alternate Design

    NASA Astrophysics Data System (ADS)

    Kritz, Arnold H.; Onjun, Thawatchai; Bateman, Glenn; Mazzucato, Ernesto

    2000-10-01

    Predictions of α-power production in FIRE and the Mazzucato proposed high-field tokamaks are examined using the Multi-Mode-95 (MMM95) and the Mixed-Bohm/gyro-Bohm (JETTO) transport models in the BALDUR transport code. Simulations of plasma evolution in the proposed tokamaks using the MMM95 model predict, after 16 seconds of 30 MW auxiliary heating, a fusion Q of 2.7 (for the FIRE design) and 8.2 (for the Mazzucato design) assuming an edge temperature of 2 keV. Our simulations show that significantly higher values Q result when the plasma current together with the magnetic field are increased, or when the plasma edge temperature is increased. The performance is moderately improved with density peaking; whereas, performance is degraded with increased Z_eff. The α-power production is found to depend on the rate at which the auxiliary heating power is turned off. The α-power remains higher when the auxiliary power is reduced gradually rather than abruptly. For plasmas with central ion temperatures greater than 10 keV, it is possible to turn off the auxiliary power with α-power remaining finite.

  19. A Guide to Learning Curve Technology to Enhance Performance Prediction in Vocational Evaluation. Research Utilization Report.

    ERIC Educational Resources Information Center

    McCray, Paul M.; Blakemore, Thomas F.

    The primary purpose of this monograph is to describe how learning curves can be applied to vocational evaluation procedures to enhance the reliability and accuracy of performance prediction. Particular emphasis is placed on describing two techniques known as the "best 20 percent method" and the "Performance Analyzer and Enhancer." The latter is a…

  20. Interactions of Team Mental Models and Monitoring Behaviors Predict Team Performance in Simulated Anesthesia Inductions

    ERIC Educational Resources Information Center

    Burtscher, Michael J.; Kolbe, Michaela; Wacker, Johannes; Manser, Tanja

    2011-01-01

    In the present study, we investigated how two team mental model properties (similarity vs. accuracy) and two forms of monitoring behavior (team vs. systems) interacted to predict team performance in anesthesia. In particular, we were interested in whether the relationship between monitoring behavior and team performance was moderated by team…

  1. Predicting Examination Performance Using an Expanded Integrated Hierarchical Model of Test Emotions and Achievement Goals

    ERIC Educational Resources Information Center

    Putwain, Dave; Deveney, Carolyn

    2009-01-01

    The aim of this study was to examine an expanded integrative hierarchical model of test emotions and achievement goal orientations in predicting the examination performance of undergraduate students. Achievement goals were theorised as mediating the relationship between test emotions and performance. 120 undergraduate students completed…

  2. The Prediction of College Student Academic Performance and Retention: Application of Expectancy and Goal Setting Theories

    ERIC Educational Resources Information Center

    Friedman, Barry A.; Mandel, Rhonda G.

    2010-01-01

    Student retention and performance in higher education are important issues for educators, students, and the nation facing critical professional labor shortages. Expectancy and goal setting theories were used to predict academic performance and college student retention. Students' academic expectancy motivation at the start of the college…

  3. Predicting One Mile and Two Mile Run Performance from Physiological Measures.

    ERIC Educational Resources Information Center

    Sucec, A. A.

    Twenty-three male distance runners between the ages of 16 and 23 who had achieved a ten-minute or better two-mile performance were tested to determine physical and physiological characteristics to be used in predictive research regarding running performance. Relative body fat ratio, metabolic data, and oxygen intake capability were among the…

  4. In Silico Modeling of Gastrointestinal Drug Absorption: Predictive Performance of Three Physiologically Based Absorption Models.

    PubMed

    Sjögren, Erik; Thörn, Helena; Tannergren, Christer

    2016-06-01

    Gastrointestinal (GI) drug absorption is a complex process determined by formulation, physicochemical and biopharmaceutical factors, and GI physiology. Physiologically based in silico absorption models have emerged as a widely used and promising supplement to traditional in vitro assays and preclinical in vivo studies. However, there remains a lack of comparative studies between different models. The aim of this study was to explore the strengths and limitations of the in silico absorption models Simcyp 13.1, GastroPlus 8.0, and GI-Sim 4.1, with respect to their performance in predicting human intestinal drug absorption. This was achieved by adopting an a priori modeling approach and using well-defined input data for 12 drugs associated with incomplete GI absorption and related challenges in predicting the extent of absorption. This approach better mimics the real situation during formulation development where predictive in silico models would be beneficial. Plasma concentration-time profiles for 44 oral drug administrations were calculated by convolution of model-predicted absorption-time profiles and reported pharmacokinetic parameters. Model performance was evaluated by comparing the predicted plasma concentration-time profiles, Cmax, tmax, and exposure (AUC) with observations from clinical studies. The overall prediction accuracies for AUC, given as the absolute average fold error (AAFE) values, were 2.2, 1.6, and 1.3 for Simcyp, GastroPlus, and GI-Sim, respectively. The corresponding AAFE values for Cmax were 2.2, 1.6, and 1.3, respectively, and those for tmax were 1.7, 1.5, and 1.4, respectively. Simcyp was associated with underprediction of AUC and Cmax; the accuracy decreased with decreasing predicted fabs. A tendency for underprediction was also observed for GastroPlus, but there was no correlation with predicted fabs. There were no obvious trends for over- or underprediction for GI-Sim. The models performed similarly in capturing dependencies on dose and

  5. Transport studies in high-performance field reversed configuration plasmas

    NASA Astrophysics Data System (ADS)

    Gupta, S.; Barnes, D. C.; Dettrick, S. A.; Trask, E.; Tuszewski, M.; Deng, B. H.; Gota, H.; Gupta, D.; Hubbard, K.; Korepanov, S.; Thompson, M. C.; Zhai, K.; Tajima, T.

    2016-05-01

    A significant improvement of field reversed configuration (FRC) lifetime and plasma confinement times in the C-2 plasma, called High Performance FRC regime, has been observed with neutral beam injection (NBI), improved edge stability, and better wall conditioning [Binderbauer et al., Phys. Plasmas 22, 056110 (2015)]. A Quasi-1D (Q1D) fluid transport code has been developed and employed to carry out transport analysis of such C-2 plasma conditions. The Q1D code is coupled to a Monte-Carlo code to incorporate the effect of fast ions, due to NBI, on the background FRC plasma. Numerically, the Q1D transport behavior with enhanced transport coefficients (but with otherwise classical parametric dependencies) such as 5 times classical resistive diffusion, classical thermal ion conductivity, 20 times classical electron thermal conductivity, and classical fast ion behavior fit with the experimentally measured time evolution of the excluded flux radius, line-integrated density, and electron/ion temperature. The numerical study shows near sustainment of poloidal flux for nearly 1 ms in the presence of NBI.

  6. Comparison of Performance Predictions for New Low-Thrust Trajectory Tools

    NASA Technical Reports Server (NTRS)

    Polsgrove, Tara; Kos, Larry; Hopkins, Randall; Crane, Tracie

    2006-01-01

    Several low thrust trajectory optimization tools have been developed over the last 3% years by the Low Thrust Trajectory Tools development team. This toolset includes both low-medium fidelity and high fidelity tools which allow the analyst to quickly research a wide mission trade space and perform advanced mission design. These tools were tested using a set of reference trajectories that exercised each tool s unique capabilities. This paper compares the performance predictions of the various tools against several of the reference trajectories. The intent is to verify agreement between the high fidelity tools and to quantify the performance prediction differences between tools of different fidelity levels.

  7. Investigating the discrepancy between the predicted and actual energy performance of buildings

    NASA Astrophysics Data System (ADS)

    Demanuele, Christine

    The threat of climate change has increased the demand for energy efficiency in buildings, with various stakeholders requesting more accurate predictions of energy consumption, and energy consultants coming under increased pressure to guarantee the energy performance of buildings. This study aims to investigate the factors causing the discrepancy which currently exists between the predicted and actual energy performance of buildings, which will lead to a deeper understanding of this discrepancy and, ultimately, more accurate energy predictions. As part of this study, a non-domestic building in London was modelled and monitored, so as to identify the main contributors to the discrepancy between the predicted and actual energy consumption. In addition, sensitivity analysis was carried out on a number of input variables to establish the set of influential parameters, and to determine whether using such techniques would successfully predict the range in which building energy consumption is likely to fall. The results show that the uncertainty calculated from differential sensitivity analysis encompasses the actual energy performance of the building. The most variable and influential parameters are those which are controlled by occupants, therefore it is paramount that management and occupants are well-informed about the building operation for energy targets to be achieved. Although the sensitivity analysis methods employed are impractical for commercial use, it is possible to develop simpler methods, encompassing all stages of building design and operation, which would decrease the discrepancy between the actual and predicted energy performance of buildings. Such techniques would be invaluable to energy consultants, for whom the cost resting on uncertainties in predictions is substantial due to more demanding clients and fines liable to be paid if energy predictions go wrong. A better understanding of the discrepancy, together with more accurate predictions, would

  8. Prediction of Coal ash leaching behavior in acid mine water, comparison of laboratory and field studies

    SciTech Connect

    ANNA, KNOX

    2005-01-10

    Strongly alkaline fluidized bed combustion ash is commonly used to control acid mine drainage in West Virginia coal mines. Objectives include acid neutralization and immobilization of the primary AMD pollutants: iron, aluminum and manganese. The process has been successful in controlling AMD though doubts remain regarding mobilization of other toxic elements present in the ash. In addition, AMD contains many toxic elements in low concentrations. And, each mine produces AMD of widely varying quality. So, predicting the effect of a particular ash on a given coal mine's drainage quality is of particular interest. In this chapter we compare the results of a site-specific ash leaching procedure with two large-scale field applications of FBC ash. The results suggested a high degree of predictability for roughly half of the 25 chemical parameters and poor predictability for the remainder. Of these, seven parameters were successfully predicted on both sites: acidity, Al, B, Ba, Fe, Ni and Zn while electrical conductivity, Ca, Cd, SO4, Pb and Sb were not successfully predicted on either site. Trends for the remaining elements: As, Ag, Be, Cu, Cr, Hg, Mg, Mn, pH, Se Tl and V were successfully predicted on one but not both mine sites.

  9. Investigation of the validity of radiosity for sound-field prediction in cubic rooms

    NASA Astrophysics Data System (ADS)

    Nosal, Eva-Marie; Hodgson, Murray; Ashdown, Ian

    2004-12-01

    This paper explores acoustical (or time-dependent) radiosity using predictions made in four cubic enclosures. The methods and algorithms used are those presented in a previous paper by the same authors [Nosal, Hodgson, and Ashdown, J. Acoust. Soc. Am. 116(2), 970-980 (2004)]. First, the algorithm, methods, and conditions for convergence are investigated by comparison of numerous predictions for the four cubic enclosures. Here, variables and parameters used in the predictions are varied to explore the effect of absorption distribution, the necessary conditions for convergence of the numerical solution to the analytical solution, form-factor prediction methods, and the computational requirements. The predictions are also used to investigate the effect of absorption distribution on sound fields in cubic enclosures with diffusely reflecting boundaries. Acoustical radiosity is then compared to predictions made in the four enclosures by a ray-tracing model that can account for diffuse reflection. Comparisons are made of echograms, room-acoustical parameters, and discretized echograms. .

  10. Investigation of the validity of radiosity for sound-field prediction in cubic rooms.

    PubMed

    Nosal, Eva-Marie; Hodgson, Murray; Ashdown, Ian

    2004-12-01

    This paper explores acoustical (or time-dependent) radiosity using predictions made in four cubic enclosures. The methods and algorithms used are those presented in a previous paper by the same authors [Nosal, Hodgson, and Ashdown, J. Acoust. Soc. Am. 116(2), 970-980 (2004)]. First, the algorithm, methods, and conditions for convergence are investigated by comparison of numerous predictions for the four cubic enclosures. Here, variables and parameters used in the predictions are varied to explore the effect of absorption distribution, the necessary conditions for convergence of the numerical solution to the analytical solution, form-factor prediction methods, and the computational requirements. The predictions are also used to investigate the effect of absorption distribution on sound fields in cubic enclosures with diffusely reflecting boundaries. Acoustical radiosity is then compared to predictions made in the four enclosures by a ray-tracing model that can account for diffuse reflection. Comparisons are made of echograms, room-acoustical parameters, and discretized echograms. PMID:15658702

  11. Characterization, performance, and prediction of a lead-acid battery under simulated electric vehicle driving requirements

    NASA Technical Reports Server (NTRS)

    Ewashinka, J. G.; Bozek, J. M.

    1981-01-01

    A state-of-the-art 6-V battery module in current use by the electric vehicle industry was tested at the NASA Lewis Research Center to determine its performance characteristics under the SAE J227a driving schedules B, C, and D. The primary objective of the tests was to determine the effects of periods of recuperation and long and short periods of electrical regeneration in improving the performance of the battery module and hence extendng the vehicle range. A secondary objective was to formulate a computer program that would predict the performance of this battery module for the above driving schedules. The results show excellent correlation between the laboratory tests and predicted results. The predicted performance compared with laboratory tests was within +2.4 to -3.7 percent for the D schedule, +0.5 to -7.1 percent for the C schedule, and better than -11.4 percent for the B schedule.

  12. Characterization, performance, and prediction of a lead-acid battery under simulated electric vehicle driving requirements

    NASA Astrophysics Data System (ADS)

    Ewashinka, J. G.; Bozek, J. M.

    1981-05-01

    A state-of-the-art 6-V battery module in current use by the electric vehicle industry was tested at the NASA Lewis Research Center to determine its performance characteristics under the SAE J227a driving schedules B, C, and D. The primary objective of the tests was to determine the effects of periods of recuperation and long and short periods of electrical regeneration in improving the performance of the battery module and hence extendng the vehicle range. A secondary objective was to formulate a computer program that would predict the performance of this battery module for the above driving schedules. The results show excellent correlation between the laboratory tests and predicted results. The predicted performance compared with laboratory tests was within +2.4 to -3.7 percent for the D schedule, +0.5 to -7.1 percent for the C schedule, and better than -11.4 percent for the B schedule.

  13. Geologic CO2 Sequestration: Predicting and Confirming Performance in Oil Reservoirs and Saline Aquifers

    NASA Astrophysics Data System (ADS)

    Johnson, J. W.; Nitao, J. J.; Newmark, R. L.; Kirkendall, B. A.; Nimz, G. J.; Knauss, K. G.; Ziagos, J. P.

    2002-05-01

    Reducing anthropogenic CO2 emissions ranks high among the grand scientific challenges of this century. In the near-term, significant reductions can only be achieved through innovative sequestration strategies that prevent atmospheric release of large-scale CO2 waste streams. Among such strategies, injection into confined geologic formations represents arguably the most promising alternative; and among potential geologic storage sites, oil reservoirs and saline aquifers represent the most attractive targets. Oil reservoirs offer a unique "win-win" approach because CO2 flooding is an effective technique of enhanced oil recovery (EOR), while saline aquifers offer immense storage capacity and widespread distribution. Although CO2-flood EOR has been widely used in the Permian Basin and elsewhere since the 1980s, the oil industry has just recently become concerned with the significant fraction of injected CO2 that eludes recycling and is therefore sequestered. This "lost" CO2 now has potential economic value in the growing emissions credit market; hence, the industry's emerging interest in recasting CO2 floods as co-optimized EOR/sequestration projects. The world's first saline aquifer storage project was also catalyzed in part by economics: Norway's newly imposed atmospheric emissions tax, which spurred development of Statoil's unique North Sea Sleipner facility in 1996. Successful implementation of geologic sequestration projects hinges on development of advanced predictive models and a diverse set of remote sensing, in situ sampling, and experimental techniques. The models are needed to design and forecast long-term sequestration performance; the monitoring techniques are required to confirm and refine model predictions and to ensure compliance with environmental regulations. We have developed a unique reactive transport modeling capability for predicting sequestration performance in saline aquifers, and used it to simulate CO2 injection at Sleipner; we are now

  14. Performance predictions for an intermediate-sized VAWT based on performance of the 34-M VAWT test bed

    SciTech Connect

    Dodd, H.M. )

    1989-01-01

    The DOE/Sandia 34-m Vertical Axis Wind Turbine (VAWT) Test Bed is a research turbine that has been in operation for over a year. With the advanced technology components incorporated in the turbine (including airfoils, structures and variable speed operation), its performance can be used to predict next generation commercial VAWT potential. This paper begins with the predicted and measured performance results obtained from the Test Bed and applies these results to a hypothetical commercial machine of the same size. The effects of a number of parameters are included in the performance analyses. First, the importance of siting considerations are presented, including wind frequency distributions (both real and Rayleigh) and mean wind speed and wind shear effects. Next, the paper shows the relative contribution of variable speed operation to improved performance and discusses other aspects of variable speed. The predicted performance of a 34-m VAWT is compared to existing machines, with annual energy capture per unit of swept area being the primary comparative metric. Finally, some cost of energy considerations associated with these technological advances are covered. 10 refs., 6 figs.

  15. Performance predictions for an intermediate-sized VAWT based on performance of the 34-m VAWT test bed

    NASA Astrophysics Data System (ADS)

    Dodd, Henry M.

    The DOE/Sandia 34-m Vertical Axis Wind Turbine (VAWT) Test Bed is a research turbine that has been in operation for over a year. With the advanced technology components incorporated in the turbine (including airfoils, structures and variable speed operation), its performance can be used to predict next generation commercial VAWT potential. This paper begins with the predicted and measured performance results obtained from the Test Bed and applies these results to a hypothetical commercial machine of the same size. The effects of a number of parameters are included in the performance analyses. First, the importance of siting considerations are presented, including wind frequency distributions (both real and Rayleigh) and mean wind speed and wind shear effects. Next, the paper shows the relative contribution of variable speed operation to improved performance and discusses other aspects of variable speed. The predicted performance of a 34-m VAWT is compared to existing machines, with annual energy capture per unit of swept area being the primary comparative metric. Finally, some cost of energy considerations associated with these technological advances are covered.

  16. Validity of the UKCAT in applicant selection and predicting exam performance in UK dental students.

    PubMed

    Lala, Rizwana; Wood, Duncan; Baker, Sarah

    2013-09-01

    The United Kingdom's Clinical Aptitude Test (UKCAT) aims to assess candidates' "natural talent" for dentistry. The aim of this study was to determine the validity of the UKCAT for dental school applicant selection. The relationship of the UKCAT with demographic and academic variables was examined, assessing if the likelihood of being offered a place at a UK dental school was predicted by demographic factors and academic selection tools (predicted grades and existing school results). Finally, the validity of these selection tools in predicting first-year dental exam performance was assessed. Correlational and regression analyses showed that females and poorer students were more likely to have lower UKCAT scores. Gender and social class did not, however, predict first-year dental exam performance. UKCAT scores predicted the likelihood of the candidate being offered a place in the dental course; however, they did not predict exam performance during the first year of the course. Indeed, the only predictor of dental exam performance was existing school results. These findings argue against the use of the UKCAT as the sole determinant in dental applicant selection, instead highlighting the value of using existing school results. PMID:24002854

  17. Predicting plasticity: acute context-dependent changes to vocal performance predict long-term age-dependent changes.

    PubMed

    James, Logan S; Sakata, Jon T

    2015-10-01

    Understanding the factors that predict and guide variation in behavioral change can lend insight into mechanisms of motor plasticity and individual differences in behavior. The performance of adult birdsong changes with age in a manner that is similar to rapid context-dependent changes to song. To reveal mechanisms of vocal plasticity, we analyzed the degree to which variation in the direction and magnitude of age-dependent changes to Bengalese finch song could be predicted by variation in context-dependent changes. Using a repeated-measures design, we found that variation in age-dependent changes to the timing, sequencing, and structure of vocal elements ("syllables") was significantly predicted by variation in context-dependent changes. In particular, the degree to which the duration of intersyllable gaps, syllable sequencing at branch points, and fundamental frequency of syllables within spontaneous [undirected (UD)] songs changed over time was correlated with the degree to which these features changed from UD song to female-directed (FD) song in young-adult finches (FDyoung). As such, the structure of some temporal features of UD songs converged over time onto the structure of FDyoung songs. This convergence suggested that the FDyoung song could serve as a stable target for vocal motor plasticity. Consequently, we analyzed the stability of FD song and found that the temporal structure of FD song changed significantly over time in a manner similar to UD song. Because FD song is considered a state of heightened performance, these data suggest that age-dependent changes could reflect practice-related improvements in vocal motor performance. PMID:26311186

  18. Energy Production Calculations with Field Flow Models and Windspeed Predictions with Statistical Methods

    NASA Astrophysics Data System (ADS)

    Rüstemoǧlu, Sevinç; Barutçu, Burak; Sibel Menteş, Å.ž.

    2010-05-01

    wind prediction. Statistical methods' preditictions as time series are included and the similartiy rates are compared for each method. The algorithms which are performed in MATLAB, gave the similarity results of each model. According to the Neural Networks results which are found to be the most successful method for prediction within these three statistical models, the windspeed similarity rate between the original measurements and the prediction set which includes 1 year period between 2003 and 2004, is evaluated as % 94.7. For wind direction, the similarity rate is %81.61. High noise margin and ability to learn the characteristics of the signal are important advantages of Neural Networks for compatible windspeed and direction predictions compared with measurements.

  19. A prescribed wake rotor inflow and flow field prediction analysis, user's manual and technical approach

    NASA Technical Reports Server (NTRS)

    Egolf, T. A.; Landgrebe, A. J.

    1982-01-01

    A user's manual is provided which includes the technical approach for the Prescribed Wake Rotor Inflow and Flow Field Prediction Analysis. The analysis is used to provide the rotor wake induced velocities at the rotor blades for use in blade airloads and response analyses and to provide induced velocities at arbitrary field points such as at a tail surface. This analysis calculates the distribution of rotor wake induced velocities based on a prescribed wake model. Section operating conditions are prescribed from blade motion and controls determined by a separate blade response analysis. The analysis represents each blade by a segmented lifting line, and the rotor wake by discrete segmented trailing vortex filaments. Blade loading and circulation distributions are calculated based on blade element strip theory including the local induced velocity predicted by the numerical integration of the Biot-Savart Law applied to the vortex wake model.

  20. Predicting the critical density of topological defects in O(N) scalar field theories

    SciTech Connect

    Antunes, Nuno D.; Bettencourt, Luis M. A.; Yates, Andrew

    2001-09-15

    O(N) symmetric {lambda}{phi}{sup 4} field theories describe many critical phenomena in the laboratory and in the early Universe. Given N and D{<=}3, the spatial dimension, these models exhibit topological defect classical solutions that in some cases fully determine their critical behavior. For N=2 and D=3, it has been observed that the defect density is seemingly a universal quantity at T{sub c}. We prove this conjecture and show how to predict its value based on the universal critical exponents of the field theory. Analogously, for general N and D we predict the universal critical densities of domain walls and monopoles, for which no detailed thermodynamic study exists, to our knowledge. Remarkably this procedure can be inverted, producing an algorithm for generating typical defect networks at criticality, in contrast with the usual procedure [Vachaspati and Vilenkin, Phys. Rev. D 30, 2036 (1984)], which applies only in the unphysical limit of infinite temperature.