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Sample records for performance evaluation model

  1. Model Performance Evaluation and Scenario Analysis (MPESA)

    EPA Pesticide Factsheets

    Model Performance Evaluation and Scenario Analysis (MPESA) assesses the performance with which models predict time series data. The tool was developed Hydrological Simulation Program-Fortran (HSPF) and the Stormwater Management Model (SWMM)

  2. Performance Evaluation of Dense Gas Dispersion Models.

    NASA Astrophysics Data System (ADS)

    Touma, Jawad S.; Cox, William M.; Thistle, Harold; Zapert, James G.

    1995-03-01

    This paper summarizes the results of a study to evaluate the performance of seven dense gas dispersion models using data from three field experiments. Two models (DEGADIS and SLAB) are in the public domain and the other five (AIRTOX, CHARM, FOCUS, SAFEMODE, and TRACE) are proprietary. The field data used are the Desert Tortoise pressurized ammonia releases, Burro liquefied natural gas spill tests, and the Goldfish anhydrous hydrofluoric acid spill experiments. Desert Tortoise and Goldfish releases were simulated as horizontal jet releases, and Burro as a liquid pool. Performance statistics were used to compare maximum observed concentrations and plume half-width to those predicted by each model. Model performance varied and no model exhibited consistently good performance across all three databases. However, when combined across the three databases, all models performed within a factor of 2. Problems encountered are discussed in order to help future investigators.

  3. Performance Evaluation Model for Application Layer Firewalls

    PubMed Central

    Yang, Wu; Dong, Hui; Zhang, Jiangchuan

    2016-01-01

    Application layer firewalls protect the trusted area network against information security risks. However, firewall performance may affect user experience. Therefore, performance analysis plays a significant role in the evaluation of application layer firewalls. This paper presents an analytic model of the application layer firewall, based on a system analysis to evaluate the capability of the firewall. In order to enable users to improve the performance of the application layer firewall with limited resources, resource allocation was evaluated to obtain the optimal resource allocation scheme in terms of throughput, delay, and packet loss rate. The proposed model employs the Erlangian queuing model to analyze the performance parameters of the system with regard to the three layers (network, transport, and application layers). Then, the analysis results of all the layers are combined to obtain the overall system performance indicators. A discrete event simulation method was used to evaluate the proposed model. Finally, limited service desk resources were allocated to obtain the values of the performance indicators under different resource allocation scenarios in order to determine the optimal allocation scheme. Under limited resource allocation, this scheme enables users to maximize the performance of the application layer firewall. PMID:27893803

  4. Performance Evaluation Model for Application Layer Firewalls.

    PubMed

    Xuan, Shichang; Yang, Wu; Dong, Hui; Zhang, Jiangchuan

    2016-01-01

    Application layer firewalls protect the trusted area network against information security risks. However, firewall performance may affect user experience. Therefore, performance analysis plays a significant role in the evaluation of application layer firewalls. This paper presents an analytic model of the application layer firewall, based on a system analysis to evaluate the capability of the firewall. In order to enable users to improve the performance of the application layer firewall with limited resources, resource allocation was evaluated to obtain the optimal resource allocation scheme in terms of throughput, delay, and packet loss rate. The proposed model employs the Erlangian queuing model to analyze the performance parameters of the system with regard to the three layers (network, transport, and application layers). Then, the analysis results of all the layers are combined to obtain the overall system performance indicators. A discrete event simulation method was used to evaluate the proposed model. Finally, limited service desk resources were allocated to obtain the values of the performance indicators under different resource allocation scenarios in order to determine the optimal allocation scheme. Under limited resource allocation, this scheme enables users to maximize the performance of the application layer firewall.

  5. Model Performance Evaluation and Scenario Analysis (MPESA) Tutorial

    EPA Science Inventory

    This tool consists of two parts: model performance evaluation and scenario analysis (MPESA). The model performance evaluation consists of two components: model performance evaluation metrics and model diagnostics. These metrics provides modelers with statistical goodness-of-fit m...

  6. Model Performance Evaluation and Scenario Analysis (MPESA) Tutorial

    EPA Science Inventory

    This tool consists of two parts: model performance evaluation and scenario analysis (MPESA). The model performance evaluation consists of two components: model performance evaluation metrics and model diagnostics. These metrics provides modelers with statistical goodness-of-fit m...

  7. Optical Storage Performance Modeling and Evaluation.

    ERIC Educational Resources Information Center

    Behera, Bailochan; Singh, Harpreet

    1990-01-01

    Evaluates different types of storage media for long-term archival storage of large amounts of data. Existing storage media are reviewed, including optical disks, optical tape, magnetic storage, and microfilm; three models are proposed based on document storage requirements; performance analysis is considered; and cost effectiveness is discussed.…

  8. Iowa Flood Center Model Performance Evaluation

    NASA Astrophysics Data System (ADS)

    Quintero, F.; Krajewski, W. F.; Mantilla, R.; Seo, B. C.

    2016-12-01

    We evaluated the performance of a hydrologic model which produces real-time flow forecasts. The model was developed by the Iowa Flood Center (IFC) and it is implemented operationally to produce streamflow forecast for the communities of the state of Iowa in the United States. The model parameters are calibration-free. It has a parsimonious structure that reproduces the more significant processes involved in the transformation from rainfall to runoff. The operational model uses a rainfall forcing produced by IFC, derived from the combination of rainfall fields of seven NEXRAD radars. This rainfall forcing does not include bias adjustment from rain gauges, due to the non-existence of a raingage network that enable the correction in real-time. Therefore, the model was also evaluated using the bias-adjusted rainfall product Stage IV. We used six years of IFC rainfall and Stage IV to evaluate the performance of the hydrologic model and the sensitivity of the flow simulations to the model input. The model was not calibrated to any particular rainfall product. The distributed structure of the model allows obtaining results at any channel of the drainage network. We produced simulated hydrographs at about 140 locations with different sub-basin spatial scales, where USGS streamflow observations are available. We compared flow simulations to observations and obtained several metrics of error including Nash Sutcliffe efficiency, normalized root mean square error, volume error and time to peak error. We also evaluated the number of occurrences of hits and false alarms of discharge forecasts exceeding flood stage.

  9. Performance Evaluation Modeling of Network Sensors

    NASA Technical Reports Server (NTRS)

    Clare, Loren P.; Jennings, Esther H.; Gao, Jay L.

    2003-01-01

    Substantial benefits are promised by operating many spatially separated sensors collectively. Such systems are envisioned to consist of sensor nodes that are connected by a communications network. A simulation tool is being developed to evaluate the performance of networked sensor systems, incorporating such metrics as target detection probabilities, false alarms rates, and classification confusion probabilities. The tool will be used to determine configuration impacts associated with such aspects as spatial laydown, and mixture of different types of sensors (acoustic, seismic, imaging, magnetic, RF, etc.), and fusion architecture. The QualNet discrete-event simulation environment serves as the underlying basis for model development and execution. This platform is recognized for its capabilities in efficiently simulating networking among mobile entities that communicate via wireless media. We are extending QualNet's communications modeling constructs to capture the sensing aspects of multi-target sensing (analogous to multiple access communications), unimodal multi-sensing (broadcast), and multi-modal sensing (multiple channels and correlated transmissions). Methods are also being developed for modeling the sensor signal sources (transmitters), signal propagation through the media, and sensors (receivers) that are consistent with the discrete event paradigm needed for performance determination of sensor network systems. This work is supported under the Microsensors Technical Area of the Army Research Laboratory (ARL) Advanced Sensors Collaborative Technology Alliance.

  10. Model Performance Evaluation and Scenario Analysis (MPESA) Tutorial

    EPA Pesticide Factsheets

    The model performance evaluation consists of metrics and model diagnostics. These metrics provides modelers with statistical goodness-of-fit measures that capture magnitude only, sequence only, and combined magnitude and sequence errors.

  11. Evaluating Models of Human Performance: Safety-Critical Systems Applications

    NASA Technical Reports Server (NTRS)

    Feary, Michael S.

    2012-01-01

    This presentation is part of panel discussion on Evaluating Models of Human Performance. The purpose of this panel is to discuss the increasing use of models in the world today and specifically focus on how to describe and evaluate models of human performance. My presentation will focus on discussions of generating distributions of performance, and the evaluation of different strategies for humans performing tasks with mixed initiative (Human-Automation) systems. I will also discuss issues with how to provide Human Performance modeling data to support decisions on acceptability and tradeoffs in the design of safety critical systems. I will conclude with challenges for the future.

  12. Hydrologic Evaluation of Landfill Performance (HELP) Model

    EPA Pesticide Factsheets

    The program models rainfall, runoff, infiltration, and other water pathways to estimate how much water builds up above each landfill liner. It can incorporate data on vegetation, soil types, geosynthetic materials, initial moisture conditions, slopes, etc.

  13. Models for evaluating the performability of degradable computing systems

    NASA Technical Reports Server (NTRS)

    Wu, L. T.

    1982-01-01

    Recent advances in multiprocessor technology established the need for unified methods to evaluate computing systems performance and reliability. In response to this modeling need, a general modeling framework that permits the modeling, analysis and evaluation of degradable computing systems is considered. Within this framework, several user oriented performance variables are identified and shown to be proper generalizations of the traditional notions of system performance and reliability. Furthermore, a time varying version of the model is developed to generalize the traditional fault tree reliability evaluation methods of phased missions.

  14. The CREATIVE Decontamination Performance Evaluation Model

    DTIC Science & Technology

    2008-06-01

    Model to Describe Penetration of Skin by Sorbed Liquids by Contact”, CRDEC-CR-87100 5. Clarke, A., “Spreading and Imbibition of Liquid Drops on...δy and δz = f•δx δt ≤ δx2 2 D ( 2 + 1/f2) C @ next time step UNCLASSIFIED/UNLIMITED UNCLASSIFIED/UNLIMITED Finite Difference Application Drop ...boundaries: 1) Drop : constant source until drop disappears 2) Base of substrate considered impenetrable 3) Sides and top of coupon allow mass to escape

  15. Metrics for evaluating performance and uncertainty of Bayesian network models

    Treesearch

    Bruce G. Marcot

    2012-01-01

    This paper presents a selected set of existing and new metrics for gauging Bayesian network model performance and uncertainty. Selected existing and new metrics are discussed for conducting model sensitivity analysis (variance reduction, entropy reduction, case file simulation); evaluating scenarios (influence analysis); depicting model complexity (numbers of model...

  16. Solid rocket booster performance evaluation model. Volume 4: Program listing

    NASA Technical Reports Server (NTRS)

    1974-01-01

    All subprograms or routines associated with the solid rocket booster performance evaluation model are indexed in this computer listing. An alphanumeric list of each routine in the index is provided in a table of contents.

  17. Performance models for automatic evaluation of virtual scanning keyboards.

    PubMed

    Bhattacharya, Samit; Samanta, Debasis; Basu, Anupam

    2008-10-01

    Virtual scanning keyboards are commonly used augmentative communication aids by persons with severe speech and motion impairments. Designers of virtual scanning keyboards face problems in evaluating alternate designs and hence in choosing the better design among alternatives. Automatic evaluation of designs will be helpful to designers in making the appropriate design choice. In this paper, we present performance models for virtual scanning keyboards that can be used for automatic evaluation. The proposed models address the limitations present in the reported work on similar models. We compared the model predictions with results from user trials and established the validity of the proposed models.

  18. Evaluating Organic Aerosol Model Performance: Impact of two Embedded Assumptions

    NASA Astrophysics Data System (ADS)

    Jiang, W.; Giroux, E.; Roth, H.; Yin, D.

    2004-05-01

    Organic aerosols are important due to their abundance in the polluted lower atmosphere and their impact on human health and vegetation. However, modeling organic aerosols is a very challenging task because of the complexity of aerosol composition, structure, and formation processes. Assumptions and their associated uncertainties in both models and measurement data make model performance evaluation a truly demanding job. Although some assumptions are obvious, others are hidden and embedded, and can significantly impact modeling results, possibly even changing conclusions about model performance. This paper focuses on analyzing the impact of two embedded assumptions on evaluation of organic aerosol model performance. One assumption is about the enthalpy of vaporization widely used in various secondary organic aerosol (SOA) algorithms. The other is about the conversion factor used to obtain ambient organic aerosol concentrations from measured organic carbon. These two assumptions reflect uncertainties in the model and in the ambient measurement data, respectively. For illustration purposes, various choices of the assumed values are implemented in the evaluation process for an air quality model based on CMAQ (the Community Multiscale Air Quality Model). Model simulations are conducted for the Lower Fraser Valley covering Southwest British Columbia, Canada, and Northwest Washington, United States, for a historical pollution episode in 1993. To understand the impact of the assumed enthalpy of vaporization on modeling results, its impact on instantaneous organic aerosol yields (IAY) through partitioning coefficients is analysed first. The analysis shows that utilizing different enthalpy of vaporization values causes changes in the shapes of IAY curves and in the response of SOA formation capability of reactive organic gases to temperature variations. These changes are then carried into the air quality model and cause substantial changes in the organic aerosol modeling

  19. Faculty performance evaluation: the CIPP-SAPS model.

    PubMed

    Mitcham, M

    1981-11-01

    The issues of faculty performance evaluation for allied health professionals are addressed. Daniel Stufflebeam's CIPP (content-input-process-product) model is introduced and its development in a CIPP-SAPS (self-administrative-peer-student) model is pursued. Data sources for the SAPS portion of the model are discussed. A suggestion for the use of the CIPP-SAPS model within a teaching contract plan is explored.

  20. Faculty Performance Evaluation: The CIPP-SAPS Model.

    ERIC Educational Resources Information Center

    Mitcham, Maralynne

    1981-01-01

    The issues of faculty performance evaluation for allied health professionals are addressed. Daniel Stufflebeam's CIPP (content-imput-process-product) model is introduced and its development into a CIPP-SAPS (self-administrative-peer- student) model is pursued. (Author/CT)

  1. Solid rocket booster performance evaluation model. Volume 2: Users manual

    NASA Technical Reports Server (NTRS)

    1974-01-01

    This users manual for the solid rocket booster performance evaluation model (SRB-II) contains descriptions of the model, the program options, the required program inputs, the program output format and the program error messages. SRB-II is written in FORTRAN and is operational on both the IBM 370/155 and the MSFC UNIVAC 1108 computers.

  2. Evaluating human performance modeling for system assessment: Promise and problems

    NASA Technical Reports Server (NTRS)

    Patterson, Robert W.; Young, Michael J.

    1992-01-01

    The development and evaluation of computational human performance models is examined. An intention is to develop models which can be used to interact with system prototypes and simulations to perform system assessment. Currently LR is working on a set of models emulating cognitive, psychomotor, auditory, and visual activity for multiple operator positions of a command and control simulation system. These models, developed in conjunction with BBN Systems and Technologies, function within the simulation environment and allow for both unmanned system assessment and manned (human-in-loop) assessment of system interface and team interactions. These are relatively generic models with built-in flexibility which allows modification of some model parameters. These models have great potential for improving the efficiency and effectiveness of system design, test, and evaluation. However, the extent of the practical utility of these models is unclear. Initial verification efforts comparing model performance within the simulation to actual human operators on a similar, independent simulation have been performed and current efforts are directed at comparing human and model performance within the same simulation environment.

  3. New performance evaluation models for character detection in images

    NASA Astrophysics Data System (ADS)

    Wang, YanWei; Ding, XiaoQing; Liu, ChangSong; Wang, Kongqiao

    2010-02-01

    Detection of characters regions is a meaningful research work for both highlighting region of interest and recognition for further information processing. A lot of researches have been performed on character localization and extraction and this leads to the great needs of performance evaluation scheme to inspect detection algorithms. In this paper, two probability models are established to accomplish evaluation tasks for different applications respectively. For highlighting region of interest, a Gaussian probability model, which simulates the property of a low-pass Gaussian filter of human vision system (HVS), was constructed to allocate different weights to different character parts. It reveals the greatest potential to describe the performance of detectors, especially, when the result detected is an incomplete character, where other methods cannot effectively work. For the recognition destination, we also introduced a weighted probability model to give an appropriate description for the contribution of detection results to final recognition results. The validity of performance evaluation models proposed in this paper are proved by experiments on web images and natural scene images. These models proposed in this paper may also be able to be applied in evaluating algorithms of locating other objects, like face detection and more wide experiments need to be done to examine the assumption.

  4. A Spectral Evaluation of Models Performances in Mediterranean Oak Woodlands

    NASA Astrophysics Data System (ADS)

    Vargas, R.; Baldocchi, D. D.; Abramowitz, G.; Carrara, A.; Correia, A.; Kobayashi, H.; Papale, D.; Pearson, D.; Pereira, J.; Piao, S.; Rambal, S.; Sonnentag, O.

    2009-12-01

    Ecosystem processes are influenced by climatic trends at multiple temporal scales including diel patterns and other mid-term climatic modes, such as interannual and seasonal variability. Because interactions between biophysical components of ecosystem processes are complex, it is important to test how models perform in frequency (e.g. hours, days, weeks, months, years) and time (i.e. day of the year) domains in addition to traditional tests of annual or monthly sums. Here we present a spectral evaluation using wavelet time series analysis of model performance in seven Mediterranean Oak Woodlands that encompass three deciduous and four evergreen sites. We tested the performance of five models (CABLE, ORCHIDEE, BEPS, Biome-BGC, and JULES) on measured variables of gross primary production (GPP) and evapotranspiration (ET). In general, model performance fails at intermediate periods (e.g. weeks to months) likely because these models do not represent the water pulse dynamics that influence GPP and ET at these Mediterranean systems. To improve the performance of a model it is critical to identify first where and when the model fails. Only by identifying where a model fails we can improve the model performance and use them as prognostic tools and to generate further hypotheses that can be tested by new experiments and measurements.

  5. Maintenance personnel performance simulation (MAPPS) model: overview and evaluation efforts

    SciTech Connect

    Knee, H.E.; Haas, P.M.; Siegel, A.I.; Bartter, W.D.; Wolf, J.J.; Ryan, T.G.

    1984-01-01

    The development of the MAPPS model has been completed and the model is currently undergoing evaluation. These efforts are addressing a number of identified issues concerning practicality, acceptability, usefulness, and validity. Preliminary analysis of the evaluation data that has been collected indicates that MAPPS will provide comprehensive and reliable data for PRA purposes and for a number of other applications. The MAPPS computer simulation model provides the user with a sophisticated tool for gaining insights into tasks performed by NPP maintenance personnel. Its wide variety of input parameters and output data makes it extremely flexible for application to a number of diverse applications. With the demonstration of favorable model evaluation results, the MAPPS model will represent a valuable source of NPP maintainer reliability data and provide PRA studies with a source of data on maintainers that has previously not existed.

  6. Evaluation of performance of predictive models for deoxynivalenol in wheat.

    PubMed

    van der Fels-Klerx, H J

    2014-02-01

    The aim of this study was to evaluate the performance of two predictive models for deoxynivalenol contamination of wheat at harvest in the Netherlands, including the use of weather forecast data and external model validation. Data were collected in a different year and from different wheat fields than data used for model development. The two models were run for six preset scenarios, varying in the period for which weather forecast data were used, from zero-day (historical data only) to a 13-day period around wheat flowering. Model predictions using forecast weather data were compared to those using historical data. Furthermore, model predictions using historical weather data were evaluated against observed deoxynivalenol contamination of the wheat fields. Results showed that the use of weather forecast data rather than observed data only slightly influenced model predictions. The percent of correct model predictions, given a threshold of 1,250 μg/kg (legal limit in European Union), was about 95% for the two models. However, only three samples had a deoxynivalenol concentration above this threshold, and the models were not able to predict these samples correctly. It was concluded that two- week weather forecast data can reliable be used in descriptive models for deoxynivalenol contamination of wheat, resulting in more timely model predictions. The two models are able to predict lower deoxynivalenol contamination correctly, but model performance in situations with high deoxynivalenol contamination needs to be further validated. This will need years with conducive environmental conditions for deoxynivalenol contamination of wheat. © 2013 Society for Risk Analysis.

  7. Performance evaluation and modeling techniques for parallel processors

    SciTech Connect

    Dimpsey, R.T.

    1992-01-01

    This thesis addresses the issue of application performance under real operational conditions. A technique is introduced which accurately models the behavior of an application in real workloads. The methodology can evaluate the performance of the application as well as predict the effects on performance of certain system design changes. The constructed model is based on measurements obtained during normal machine operation and captures various performance issues including multiprogramming and system overheads, and contentions for resources. Methodologies to measure multiprogramming overhead (MPO) are introduced and illustrated on an Alliant FX/8, an Alliant Fx/80, and the Cedar parallel supercomputer. The measurements collected suggest that multiprogramming and system overheads can significantly impact application performance. The mean MPO incurred by PERFECT benchmarks executing in real workloads on an Alliant FX/80 is found to consume 16% of the processing power. Flor applications executing Cedar, between 10% and 60% of the application completion time is attributable to overhead caused by multiprogramming. Measurements also identify a Cedar FORTRAN construct (SDOALL) which is susceptible to performance degradation due to multiprogramming. Using the MPO measurements, the application performance model discussed above is constructed for computationally bound, parallel jobs executing on an Alliant FX/80. It is shown that the model can predict application completion time under real workloads. This is illustrated with several examples from the Perfect Benchmark suite. It is also shown that the model can predict the performance impact of system design changes. For example, the completion times of applications under a new scheduling policy are predicted. The model-building methodology is then validated with a number of empirical experiments.

  8. Solid rocket booster performance evaluation model. Volume 1: Engineering description

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The space shuttle solid rocket booster performance evaluation model (SRB-II) is made up of analytical and functional simulation techniques linked together so that a single pass through the model will predict the performance of the propulsion elements of a space shuttle solid rocket booster. The available options allow the user to predict static test performance, predict nominal and off nominal flight performance, and reconstruct actual flight and static test performance. Options selected by the user are dependent on the data available. These can include data derived from theoretical analysis, small scale motor test data, large motor test data and motor configuration data. The user has several options for output format that include print, cards, tape and plots. Output includes all major performance parameters (Isp, thrust, flowrate, mass accounting and operating pressures) as a function of time as well as calculated single point performance data. The engineering description of SRB-II discusses the engineering and programming fundamentals used, the function of each module, and the limitations of each module.

  9. Performance Evaluation of 3d Modeling Software for Uav Photogrammetry

    NASA Astrophysics Data System (ADS)

    Yanagi, H.; Chikatsu, H.

    2016-06-01

    UAV (Unmanned Aerial Vehicle) photogrammetry, which combines UAV and freely available internet-based 3D modeling software, is widely used as a low-cost and user-friendly photogrammetry technique in the fields such as remote sensing and geosciences. In UAV photogrammetry, only the platform used in conventional aerial photogrammetry is changed. Consequently, 3D modeling software contributes significantly to its expansion. However, the algorithms of the 3D modelling software are black box algorithms. As a result, only a few studies have been able to evaluate their accuracy using 3D coordinate check points. With this motive, Smart3DCapture and Pix4Dmapper were downloaded from the Internet and commercial software PhotoScan was also employed; investigations were performed in this paper using check points and images obtained from UAV.

  10. Evaluation of detection model performance in power-law noise

    NASA Astrophysics Data System (ADS)

    Burgess, Arthur E.

    2001-06-01

    Two alternative forced-choice (2AFC) nodule detection performances of a number of model observers were evaluated for detection of simulated nodules in filtered power-law (1/f3) noise. The models included the ideal observer, the channelized Fisher-Hotelling (FH) model with two different basis function sets, the non-prewhitening matched filter with an eye filter (NPWE), and the Rose model with no DC response (RoseNDC). Detectability of the designer nodule signal was investigated. It has equation s((rho) )equalsA*Rect((rho) /2)(1-(rho) 2)v, where (rho) is a normalized distance (r/R), R is the nodule radius and A is signal amplitude. The nodule profile can be changed (designed) by changing the value of v. For example, the result is a sharp-edged, flat-topped disc for v equal to zero and the projection of a sphere for v equal to 0.5. Human observer experiments were done with nodules based on v equal to 0, 0.5 and 1.5. For the v equal to 1.5 case, human results could be well fitted using a variety of models. The human CD diagram slopes were -0.12, +0.27 and +0.44 for v equal to 0, 0.5 and 1.5 respectively.

  11. Proper bibeta ROC model: algorithm, software, and performance evaluation

    NASA Astrophysics Data System (ADS)

    Chen, Weijie; Hu, Nan

    2016-03-01

    Semi-parametric models are often used to fit data collected in receiver operating characteristic (ROC) experiments to obtain a smooth ROC curve and ROC parameters for statistical inference purposes. The proper bibeta model as recently proposed by Mossman and Peng enjoys several theoretical properties. In addition to having explicit density functions for the latent decision variable and an explicit functional form of the ROC curve, the two parameter bibeta model also has simple closed-form expressions for true-positive fraction (TPF), false-positive fraction (FPF), and the area under the ROC curve (AUC). In this work, we developed a computational algorithm and R package implementing this model for ROC curve fitting. Our algorithm can deal with any ordinal data (categorical or continuous). To improve accuracy, efficiency, and reliability of our software, we adopted several strategies in our computational algorithm including: (1) the LABROC4 categorization to obtain the true maximum likelihood estimation of the ROC parameters; (2) a principled approach to initializing parameters; (3) analytical first-order and second-order derivatives of the likelihood function; (4) an efficient optimization procedure (the L-BFGS algorithm in the R package "nlopt"); and (5) an analytical delta method to estimate the variance of the AUC. We evaluated the performance of our software with intensive simulation studies and compared with the conventional binormal and the proper binormal-likelihood-ratio models developed at the University of Chicago. Our simulation results indicate that our software is highly accurate, efficient, and reliable.

  12. Evaluation of multidimensional models of WAIS-IV subtest performance.

    PubMed

    McFarland, Dennis J

    The present study examined the extent to which the covariance structure of the WAIS-IV is best accounted for by models that assume that test performance is the result of group-level factors and multiple independent general factors. Structural models with one to four general factors were evaluated with either four or five group-level factors. Simulations based on four general factors were run to clarify the adequacy of the estimates of the allocation of covariance by the models. Four independent general factors provided better fit than a single general factor for either model with four or five group-level factors. While one of the general factors had much larger loadings than all other factors, simulation results suggested that this might be an artifact of the statistical procedure rather than a reflection of the nature of individual differences in cognitive abilities. These results argue against the contention that clinical interpretation of cognitive test batteries should primarily be at the level of general intelligence. It is a fallacy to assume that factor analysis can reveal the structure of human abilities. Test validity should not be based solely on the results of modeling the covariance of test batteries.

  13. Experimental performance evaluation of human balance control models.

    PubMed

    Huryn, Thomas P; Blouin, Jean-Sébastien; Croft, Elizabeth A; Koehle, Michael S; Van der Loos, H F Machiel

    2014-11-01

    Two factors commonly differentiate proposed balance control models for quiet human standing: 1) intermittent muscle activation and 2) prediction that overcomes sensorimotor time delays. In this experiment we assessed the viability and performance of intermittent activation and prediction in a balance control loop that included the neuromuscular dynamics of human calf muscles. Muscles were driven by functional electrical stimulation (FES). The performance of the different controllers was compared based on sway patterns and mechanical effort required to balance a human body load on a robotic balance simulator. All evaluated controllers balanced subjects with and without a neural block applied to their common peroneal and tibial nerves, showing that the models can produce stable balance in the absence of natural activation. Intermittent activation required less stimulation energy than continuous control but predisposed the system to increased sway. Relative to intermittent control, continuous control reproduced the sway size of natural standing better. Prediction was not necessary for stable balance control but did improve stability when control was intermittent, suggesting a possible benefit of a predictor for intermittent activation. Further application of intermittent activation and predictive control models may drive prolonged, stable FES-controlled standing that improves quality of life for people with balance impairments.

  14. An evaluation of sex-age-kill (SAK) model performance

    USGS Publications Warehouse

    Millspaugh, Joshua J.; Skalski, John R.; Townsend, Richard L.; Diefenbach, Duane R.; Boyce, Mark S.; Hansen, Lonnie P.; Kammermeyer, Kent

    2009-01-01

    The sex-age-kill (SAK) model is widely used to estimate abundance of harvested large mammals, including white-tailed deer (Odocoileus virginianus). Despite a long history of use, few formal evaluations of SAK performance exist. We investigated how violations of the stable age distribution and stationary population assumption, changes to male or female harvest, stochastic effects (i.e., random fluctuations in recruitment and survival), and sampling efforts influenced SAK estimation. When the simulated population had a stable age distribution and λ > 1, the SAK model underestimated abundance. Conversely, when λ < 1, the SAK overestimated abundance. When changes to male harvest were introduced, SAK estimates were opposite the true population trend. In contrast, SAK estimates were robust to changes in female harvest rates. Stochastic effects caused SAK estimates to fluctuate about their equilibrium abundance, but the effect dampened as the size of the surveyed population increased. When we considered both stochastic effects and sampling error at a deer management unit scale the resultant abundance estimates were within ±121.9% of the true population level 95% of the time. These combined results demonstrate extreme sensitivity to model violations and scale of analysis. Without changes to model formulation, the SAK model will be biased when λ ≠ 1. Furthermore, any factor that alters the male harvest rate, such as changes to regulations or changes in hunter attitudes, will bias population estimates. Sex-age-kill estimates may be precise at large spatial scales, such as the state level, but less so at the individual management unit level. Alternative models, such as statistical age-at-harvest models, which require similar data types, might allow for more robust, broad-scale demographic assessments.

  15. Novel Planar Electromagnetic Sensors: Modeling and Performance Evaluation

    PubMed Central

    Mukhopadhyay, Subhas C.

    2005-01-01

    High performance planar electromagnetic sensors, their modeling and a few applications have been reported in this paper. The researches employing planar type electromagnetic sensors have started quite a few years back with the initial emphasis on the inspection of defects on printed circuit board. The use of the planar type sensing system has been extended for the evaluation of near-surface material properties such as conductivity, permittivity, permeability etc and can also be used for the inspection of defects in the near-surface of materials. Recently the sensor has been used for the inspection of quality of saxophone reeds and dairy products. The electromagnetic responses of planar interdigital sensors with pork meats have been investigated.

  16. Evaluation of Turbulence-Model Performance in Jet Flows

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    The importance of reducing jet noise in both commercial and military aircraft applications has made jet acoustics a significant area of research. A technique for jet noise prediction commonly employed in practice is the MGB approach, based on the Lighthill acoustic analogy. This technique requires as aerodynamic input mean flow quantities and turbulence quantities like the kinetic energy and the dissipation. The purpose of the present paper is to assess existing capabilities for predicting these aerodynamic inputs. Two modern Navier-Stokes flow solvers, coupled with several modern turbulence models, are evaluated by comparison with experiment for their ability to predict mean flow properties in a supersonic jet plume. Potential weaknesses are identified for further investigation. Another comparison with similar intent is discussed by Barber et al. The ultimate goal of this research is to develop a reliable flow solver applicable to the low-noise, propulsion-efficient, nozzle exhaust systems being developed in NASA focused programs. These programs address a broad range of complex nozzle geometries operating in high temperature, compressible, flows. Seiner et al. previously discussed the jet configuration examined here. This convergent-divergent nozzle with an exit diameter of 3.6 inches was designed for an exhaust Mach number of 2.0 and a total temperature of 1680 F. The acoustic and aerodynamic data reported by Seiner et al. covered a range of jet total temperatures from 104 F to 2200 F at the fully-expanded nozzle pressure ratio. The aerodynamic data included centerline mean velocity and total temperature profiles. Computations were performed independently with two computational fluid dynamics (CFD) codes, ISAAC and PAB3D. Turbulence models employed include the k-epsilon model, the Gatski-Speziale algebraic-stress model and the Girimaji model, with and without the Sarkar compressibility correction. Centerline values of mean velocity and mean temperature are

  17. Simulation Modeling and Performance Evaluation of Space Networks

    NASA Technical Reports Server (NTRS)

    Jennings, Esther H.; Segui, John

    2006-01-01

    In space exploration missions, the coordinated use of spacecraft as communication relays increases the efficiency of the endeavors. To conduct trade-off studies of the performance and resource usage of different communication protocols and network designs, JPL designed a comprehensive extendable tool, the Multi-mission Advanced Communications Hybrid Environment for Test and Evaluation (MACHETE). The design and development of MACHETE began in 2000 and is constantly evolving. Currently, MACHETE contains Consultative Committee for Space Data Systems (CCSDS) protocol standards such as Proximity-1, Advanced Orbiting Systems (AOS), Packet Telemetry/Telecommand, Space Communications Protocol Specification (SCPS), and the CCSDS File Delivery Protocol (CFDP). MACHETE uses the Aerospace Corporation s Satellite Orbital Analysis Program (SOAP) to generate the orbital geometry information and contact opportunities. Matlab scripts provide the link characteristics. At the core of MACHETE is a discrete event simulator, QualNet. Delay Tolerant Networking (DTN) is an end-to-end architecture providing communication in and/or through highly stressed networking environments. Stressed networking environments include those with intermittent connectivity, large and/or variable delays, and high bit error rates. To provide its services, the DTN protocols reside at the application layer of the constituent internets, forming a store-and-forward overlay network. The key capabilities of the bundling protocols include custody-based reliability, ability to cope with intermittent connectivity, ability to take advantage of scheduled and opportunistic connectivity, and late binding of names to addresses. In this presentation, we report on the addition of MACHETE models needed to support DTN, namely: the Bundle Protocol (BP) model. To illustrate the use of MACHETE with the additional DTN model, we provide an example simulation to benchmark its performance. We demonstrate the use of the DTN protocol

  18. Simulation Modeling and Performance Evaluation of Space Networks

    NASA Technical Reports Server (NTRS)

    Jennings, Esther H.; Segui, John

    2006-01-01

    In space exploration missions, the coordinated use of spacecraft as communication relays increases the efficiency of the endeavors. To conduct trade-off studies of the performance and resource usage of different communication protocols and network designs, JPL designed a comprehensive extendable tool, the Multi-mission Advanced Communications Hybrid Environment for Test and Evaluation (MACHETE). The design and development of MACHETE began in 2000 and is constantly evolving. Currently, MACHETE contains Consultative Committee for Space Data Systems (CCSDS) protocol standards such as Proximity-1, Advanced Orbiting Systems (AOS), Packet Telemetry/Telecommand, Space Communications Protocol Specification (SCPS), and the CCSDS File Delivery Protocol (CFDP). MACHETE uses the Aerospace Corporation s Satellite Orbital Analysis Program (SOAP) to generate the orbital geometry information and contact opportunities. Matlab scripts provide the link characteristics. At the core of MACHETE is a discrete event simulator, QualNet. Delay Tolerant Networking (DTN) is an end-to-end architecture providing communication in and/or through highly stressed networking environments. Stressed networking environments include those with intermittent connectivity, large and/or variable delays, and high bit error rates. To provide its services, the DTN protocols reside at the application layer of the constituent internets, forming a store-and-forward overlay network. The key capabilities of the bundling protocols include custody-based reliability, ability to cope with intermittent connectivity, ability to take advantage of scheduled and opportunistic connectivity, and late binding of names to addresses. In this presentation, we report on the addition of MACHETE models needed to support DTN, namely: the Bundle Protocol (BP) model. To illustrate the use of MACHETE with the additional DTN model, we provide an example simulation to benchmark its performance. We demonstrate the use of the DTN protocol

  19. Evaluating Organizational Performance: Rational, Natural, and Open System Models

    ERIC Educational Resources Information Center

    Martz, Wes

    2013-01-01

    As the definition of organization has evolved, so have the approaches used to evaluate organizational performance. During the past 60 years, organizational theorists and management scholars have developed a comprehensive line of thinking with respect to organizational assessment that serves to inform and be informed by the evaluation discipline.…

  20. Hydrologic and water quality models: Performance measures and evaluation criteria

    USDA-ARS?s Scientific Manuscript database

    Performance measures and corresponding criteria constitute an important aspect of calibration and validation of any hydrological and water quality (H/WQ) model. As new and improved methods and information are developed, it is essential that performance measures and criteria be updated. Therefore, th...

  1. Evaluating performances of simplified physically based landslide susceptibility models.

    NASA Astrophysics Data System (ADS)

    Capparelli, Giovanna; Formetta, Giuseppe; Versace, Pasquale

    2015-04-01

    Rainfall induced shallow landslides cause significant damages involving loss of life and properties. Prediction of shallow landslides susceptible locations is a complex task that involves many disciplines: hydrology, geotechnical science, geomorphology, and statistics. Usually to accomplish this task two main approaches are used: statistical or physically based model. This paper presents a package of GIS based models for landslide susceptibility analysis. It was integrated in the NewAge-JGrass hydrological model using the Object Modeling System (OMS) modeling framework. The package includes three simplified physically based models for landslides susceptibility analysis (M1, M2, and M3) and a component for models verifications. It computes eight goodness of fit indices (GOF) by comparing pixel-by-pixel model results and measurements data. Moreover, the package integration in NewAge-JGrass allows the use of other components such as geographic information system tools to manage inputs-output processes, and automatic calibration algorithms to estimate model parameters. The system offers the possibility to investigate and fairly compare the quality and the robustness of models and models parameters, according a procedure that includes: i) model parameters estimation by optimizing each of the GOF index separately, ii) models evaluation in the ROC plane by using each of the optimal parameter set, and iii) GOF robustness evaluation by assessing their sensitivity to the input parameter variation. This procedure was repeated for all three models. The system was applied for a case study in Calabria (Italy) along the Salerno-Reggio Calabria highway, between Cosenza and Altilia municipality. The analysis provided that among all the optimized indices and all the three models, Average Index (AI) optimization coupled with model M3 is the best modeling solution for our test case. This research was funded by PON Project No. 01_01503 "Integrated Systems for Hydrogeological Risk

  2. The Rasch Model for Evaluating Italian Student Performance

    ERIC Educational Resources Information Center

    Camminatiello, Ida; Gallo, Michele; Menini, Tullio

    2010-01-01

    In 1997 the Organisation for Economic Co-operation and Development (OECD) launched the OECD Programme for International Student Assessment (PISA) for collecting information about 15-year-old students in participating countries. Our study analyses the PISA 2006 cognitive test for evaluating the Italian student performance in mathematics, reading…

  3. Evaluating performances of simplified physically based models for landslide susceptibility

    NASA Astrophysics Data System (ADS)

    Formetta, G.; Capparelli, G.; Versace, P.

    2015-12-01

    Rainfall induced shallow landslides cause loss of life and significant damages involving private and public properties, transportation system, etc. Prediction of shallow landslides susceptible locations is a complex task that involves many disciplines: hydrology, geotechnical science, geomorphology, and statistics. Usually to accomplish this task two main approaches are used: statistical or physically based model. Reliable models' applications involve: automatic parameters calibration, objective quantification of the quality of susceptibility maps, model sensitivity analysis. This paper presents a methodology to systemically and objectively calibrate, verify and compare different models and different models performances indicators in order to individuate and eventually select the models whose behaviors are more reliable for a certain case study. The procedure was implemented in package of models for landslide susceptibility analysis and integrated in the NewAge-JGrass hydrological model. The package includes three simplified physically based models for landslides susceptibility analysis (M1, M2, and M3) and a component for models verifications. It computes eight goodness of fit indices by comparing pixel-by-pixel model results and measurements data. Moreover, the package integration in NewAge-JGrass allows the use of other components such as geographic information system tools to manage inputs-output processes, and automatic calibration algorithms to estimate model parameters. The system was applied for a case study in Calabria (Italy) along the Salerno-Reggio Calabria highway, between Cosenza and Altilia municipality. The analysis provided that among all the optimized indices and all the three models, the optimization of the index distance to perfect classification in the receiver operating characteristic plane (D2PC) coupled with model M3 is the best modeling solution for our test case.

  4. Evaluating hydrological model performance using information theory-based metrics

    USDA-ARS?s Scientific Manuscript database

    The accuracy-based model performance metrics not necessarily reflect the qualitative correspondence between simulated and measured streamflow time series. The objective of this work was to use the information theory-based metrics to see whether they can be used as complementary tool for hydrologic m...

  5. Photovoltaic performance models: an evaluation with actual field data

    NASA Astrophysics Data System (ADS)

    TamizhMani, Govindasamy; Ishioye, John-Paul; Voropayev, Arseniy; Kang, Yi

    2008-08-01

    Prediction of energy production is crucial to the design and installation of the building integrated photovoltaic systems. This prediction should be attainable based on the commonly available parameters such as system size, orientation and tilt angle. Several commercially available as well as free downloadable software tools exist to predict energy production. Six software models have been evaluated in this study and they are: PV Watts, PVsyst, MAUI, Clean Power Estimator, Solar Advisor Model (SAM) and RETScreen. This evaluation has been done by comparing the monthly, seasonaly and annually predicted data with the actual, field data obtained over a year period on a large number of residential PV systems ranging between 2 and 3 kWdc. All the systems are located in Arizona, within the Phoenix metropolitan area which lies at latitude 33° North, and longitude 112 West, and are all connected to the electrical grid.

  6. Towards Modeling Realistic Mobility for Performance Evaluations in MANET

    NASA Astrophysics Data System (ADS)

    Aravind, Alex; Tahir, Hassan

    Simulation modeling plays crucial role in conducting research on complex dynamic systems like mobile ad hoc networks and often the only way. Simulation has been successfully applied in MANET for more than two decades. In several recent studies, it is observed that the credibility of the simulation results in the field has decreased while the use of simulation has steadily increased. Part of this credibility crisis has been attributed to the simulation of mobility of the nodes in the system. Mobility has such a fundamental influence on the behavior and performance of mobile ad hoc networks. Accurate modeling and knowledge of mobility of the nodes in the system is not only helpful but also essential for the understanding and interpretation of the performance of the system under study. Several ideas, mostly in isolation, have been proposed in the literature to infuse realism in the mobility of nodes. In this paper, we attempt a holistic analysis of creating realistic mobility models and then demonstrate creation and analysis of realistic mobility models using a software tool we have developed. Using our software tool, desired mobility of the nodes in the system can be specified, generated, analyzed, and then the trace can be exported to be used in the performance studies of proposed algorithms or systems.

  7. Performance Evaluation of the Prototype Model NEXT Ion Thruster

    NASA Technical Reports Server (NTRS)

    Herman, Daniel A.; Soulas, George C.; Patterson, Michael J.

    2008-01-01

    The performance testing results of the first prototype model NEXT ion engine, PM1, are presented. The NEXT program has developed the next generation ion propulsion system to enhance and enable Discovery, New Frontiers, and Flagship-type NASA missions. The PM1 thruster exhibits operational behavior consistent with its predecessors, the engineering model thrusters, with substantial mass savings, enhanced thermal margins, and design improvements for environmental testing compliance. The dry mass of PM1 is 12.7 kg. Modifications made in the thruster design have resulted in improved performance and operating margins, as anticipated. PM1 beginning-of-life performance satisfies all of the electric propulsion thruster mission-derived technical requirements. It demonstrates a wide range of throttleability by processing input power levels from 0.5 to 6.9 kW. At 6.9 kW, the PM1 thruster demonstrates specific impulse of 4190 s, 237 mN of thrust, and a thrust efficiency of 0.71. The flat beam profile, flatness parameters vary from 0.66 at low-power to 0.88 at full-power, and advanced ion optics reduce localized accelerator grid erosion and increases margins for electron backstreaming, impingement-limited voltage, and screen grid ion transparency. The thruster throughput capability is predicted to exceed 750 kg of xenon, an equivalent of 36,500 hr of continuous operation at the full-power operating condition.

  8. Work performance evaluation using the exercising rat model

    SciTech Connect

    Stavert, D.M.; Lehnert, B.E.

    1987-01-01

    A treadmill-metabolic chamber system and a stress testing protocol have been developed to evaluate aerobic work performance on exercising rats that have inhaled toxic substances. The chamber with an enclosed treadmill provides the means to measure the physiologic status of rats during maximal work intensities in terms of O/sub 2/ consumption (V/sub 02/) and CO/sub 2/ production (V/sub c02/). The metabolic chamber can also accommodate instrumented rats for more detailed analyses of their cardiopulmonary status, e.g., ECG, cardiac output, arterial blood gases and pH, and arterial and venous blood pressures. For such studies, an arterial/venous catheter preparation is required. Because of the severe metabolic alterations after such surgery, a post surgical recovery strategy using hyperalimentation was developed to ensure maximal performance of instrumented animals during stress testing. Actual work performance studies are conducted using an eight minute stress test protocol in which the rat is subjected to increasing external work. The metabolic state of the animal is measured from resting levels to maximum oxygen consumption (V/sub 02max/). V/sub 02max/ has been shown to be reproducible in individual rats and is a sensitive indicator of oxidant gas-induced pulmonary damage. 3 tabs.

  9. Validation of Ultrafilter Performance Model Based on Systematic Simulant Evaluation

    SciTech Connect

    Russell, Renee L.; Billing, Justin M.; Smith, Harry D.; Peterson, Reid A.

    2009-11-18

    Because of limited availability of test data with actual Hanford tank waste samples, a method was developed to estimate expected filtration performance based on physical characterization data for the Hanford Tank Waste Treatment and Immobilization Plant. A test with simulated waste was analyzed to demonstrate that filtration of this class of waste is consistent with a concentration polarization model. Subsequently, filtration data from actual waste samples were analyzed to demonstrate that centrifuged solids concentrations provide a reasonable estimate of the limiting concentration for filtration.

  10. Performance evaluation of four directional emissivity analytical models with thermal SAIL model and airborne images.

    PubMed

    Ren, Huazhong; Liu, Rongyuan; Yan, Guangjian; Li, Zhao-Liang; Qin, Qiming; Liu, Qiang; Nerry, Françoise

    2015-04-06

    Land surface emissivity is a crucial parameter in the surface status monitoring. This study aims at the evaluation of four directional emissivity models, including two bi-directional reflectance distribution function (BRDF) models and two gap-frequency-based models. Results showed that the kernel-driven BRDF model could well represent directional emissivity with an error less than 0.002, and was consequently used to retrieve emissivity with an accuracy of about 0.012 from an airborne multi-angular thermal infrared data set. Furthermore, we updated the cavity effect factor relating to multiple scattering inside canopy, which improved the performance of the gap-frequency-based models.

  11. visCOS: An R-package to evaluate model performance of hydrological models

    NASA Astrophysics Data System (ADS)

    Klotz, Daniel; Herrnegger, Mathew; Wesemann, Johannes; Schulz, Karsten

    2016-04-01

    The evaluation of model performance is a central part of (hydrological) modelling. Much attention has been given to the development of evaluation criteria and diagnostic frameworks. (Klemeš, 1986; Gupta et al., 2008; among many others). Nevertheless, many applications exist for which objective functions do not yet provide satisfying summaries. Thus, the necessity to visualize results arises in order to explore a wider range of model capacities, be it strengths or deficiencies. Visualizations are usually devised for specific projects and these efforts are often not distributed to a broader community (e.g. via open source software packages). Hence, the opportunity to explicitly discuss a state-of-the-art presentation technique is often missed. We therefore present a comprehensive R-package for evaluating model performance by visualizing and exploring different aspects of hydrological time-series. The presented package comprises a set of useful plots and visualization methods, which complement existing packages, such as hydroGOF (Zambrano-Bigiarini et al., 2012). It is derived from practical applications of the hydrological models COSERO and COSEROreg (Kling et al., 2014). visCOS, providing an interface in R, represents an easy-to-use software package for visualizing and assessing model performance and can be implemented in the process of model calibration or model development. The package provides functions to load hydrological data into R, clean the data, process, visualize, explore and finally save the results in a consistent way. Together with an interactive zoom function of the time series, an online calculation of the objective functions for variable time-windows is included. Common hydrological objective functions, such as the Nash-Sutcliffe Efficiency and the Kling-Gupta Efficiency, can also be evaluated and visualized in different ways for defined sub-periods like hydrological years or seasonal sections. Many hydrologists use long-term water-balances as a

  12. Data Mining Meets Performance Evaluation: Fast Algorithms for Modeling Bursty Traffic

    DTIC Science & Technology

    2001-04-01

    Data Mining Meets Performance Evaluation: Fast Algorithms for Modeling Bursty Traffic Mengzhi Wang Tara Madhyastha Ngai Hang Chan Spiros...2001 4. TITLE AND SUBTITLE Data Mining Meets Performance Evaluation: Fast Algorithms for Modeling Bursty Traffic 5a. CONTRACT NUMBER 5b. GRANT

  13. Evaluation of the Service Review Model with Performance Scorecards

    ERIC Educational Resources Information Center

    Szabo, Thomas G.; Williams, W. Larry; Rafacz, Sharlet D.; Newsome, William; Lydon, Christina A.

    2012-01-01

    The current study combined a management technique termed "Service Review" with performance scorecards to enhance staff and consumer behavior in a human service setting consisting of 11 supervisors and 56 front-line staff working with 9 adult consumers with challenging behaviors. Results of our intervention showed that service review and…

  14. Evaluation of the Service Review Model with Performance Scorecards

    ERIC Educational Resources Information Center

    Szabo, Thomas G.; Williams, W. Larry; Rafacz, Sharlet D.; Newsome, William; Lydon, Christina A.

    2012-01-01

    The current study combined a management technique termed "Service Review" with performance scorecards to enhance staff and consumer behavior in a human service setting consisting of 11 supervisors and 56 front-line staff working with 9 adult consumers with challenging behaviors. Results of our intervention showed that service review and…

  15. Modeling soil vapor extraction to evaluate performance of a system

    SciTech Connect

    Struttman, T.J. ); Zachary, S.P. )

    1992-01-01

    The site described, located in northeast Ohio, originally had a 5,000 gallon UST that was used to supply gasoline. The tank was determined to be leaking from the fill port. Soil borings were augured to depth of 35 feet to determine the extent of soil contamination. At 20 to 30 feet in depth, contamination extended radially 50 to 60 feet. The estimated 1,600 cubic yard volume, as well as the proximity of existing buildings, made excavation, removal and disposal not cost effective. The depth of contaminated soils made bioremediation impractical. It was determined that sufficient information was available to install a vapor extraction system. The system includes 4 wells that can be individually drafted, a common vapor demister, and a 200 scfm induced draft fan. Vapor probes were installed to monitor both vacuum pressure and vapor concentration. The remediation was streamlined by focusing on installation of equipment and optimization of the system dynamics (operation). Data are collected monthly on individual well pressures, gas concentrations and mass loading in the exhaust. Analysis of these data yields radius of influence and contaminant mass withdrawal values. The draft to individual wells can be adjusted when needed to optimize system withdrawals. A model was developed, based on MODFLOW, and adapted to vapor extraction using known gas flow equations. The model was verified with known observed data. The results of this model were compared with data from the above site to determine appropriateness of using the model to design SVE system.

  16. The performance evaluation model of mining project founded on the weight optimization entropy value method

    NASA Astrophysics Data System (ADS)

    Mao, Chao; Chen, Shou

    2017-01-01

    According to the traditional entropy value method still have low evaluation accuracy when evaluating the performance of mining projects, a performance evaluation model of mineral project founded on improved entropy is proposed. First establish a new weight assignment model founded on compatible matrix analysis of analytic hierarchy process (AHP) and entropy value method, when the compatibility matrix analysis to achieve consistency requirements, if it has differences between subjective weights and objective weights, moderately adjust both proportions, then on this basis, the fuzzy evaluation matrix for performance evaluation. The simulation experiments show that, compared with traditional entropy and compatible matrix analysis method, the proposed performance evaluation model of mining project based on improved entropy value method has higher accuracy assessment.

  17. Assessment of classical performance measures and signature indices from Flow Duration Curves for model evaluation.

    NASA Astrophysics Data System (ADS)

    Ley, Rita; Hellebrand, Hugo; Casper, Markus C.; Fenicia, Fabrizio

    2015-04-01

    The result of model evaluation is strongly influenced by the choice of the used performance measures. There exist a large variety of performance measures, each with its strengths and weaknesses. Although all of them represent the ability of a hydrological model to reproduce observed stream flow, it is unclear which one is most appropriate for specific applications. The objective of this study is to investigate which performance measure is best suited to find a best performing model structure for a single basin out of multiple model structures. We compare the usability of a new performance measure, the Standardized Signature Index Sum, with several classical statistical performance measures and hydrological performance measures like the Root Mean Square Error or the Nash and Sutcliffe Efficiency. In contrast to the classical and hydrological performance measures, the Standardized Signature Index Sum is based on the comparison of observed and simulated Flow Duration Curves (FDCs). It combines the performance for different parts of the FDC to one measure considering the whole FDC and therefore the whole hydrograph. For this purpose 12 model structures were generated using the SUPERFLEX modeling framework and applied to 53 meso-scale basins in Rhineland Palatinate (Germany). For all calibrated models based on the 12 model structures and 53 basins, we calculate several performance measures and compare their usability to identify a best performing model structure for each basin. In many cases the classical performance measures and the hydrological performance measures assigned similar values to seemingly different hydrographs simulated with different model structures. Therefore, these measures are not well suited for model comparison. The proposed Standardized Signature Index Sum is more effective in revealing differences between model results. Furthermore, it provides information in which part of the hydrograph and how a model fails. The Signature Index Sum allows for a

  18. A model for evaluating the social performance of construction waste management

    SciTech Connect

    Yuan Hongping

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Scant attention is paid to social performance of construction waste management (CWM). Black-Right-Pointing-Pointer We develop a model for assessing the social performance of CWM. Black-Right-Pointing-Pointer With the model, the social performance of CWM can be quantitatively simulated. - Abstract: It has been determined by existing literature that a lot of research efforts have been made to the economic performance of construction waste management (CWM), but less attention is paid to investigation of the social performance of CWM. This study therefore attempts to develop a model for quantitatively evaluating the social performance of CWM by using a system dynamics (SD) approach. Firstly, major variables affecting the social performance of CWM are identified and a holistic system for assessing the social performance of CWM is formulated in line with feedback relationships underlying these variables. The developed system is then converted into a SD model through the software iThink. An empirical case study is finally conducted to demonstrate application of the model. Results of model validation indicate that the model is robust and reasonable to reflect the situation of the real system under study. Findings of the case study offer helpful insights into effectively promoting the social performance of CWM of the project investigated. Furthermore, the model exhibits great potential to function as an experimental platform for dynamically evaluating effects of management measures on improving the social performance of CWM of construction projects.

  19. An integrated radiance throughput model for hypersonic interceptor seeker performance evaluation

    NASA Astrophysics Data System (ADS)

    Wyman, Charles L.; Andrzejewski, Joseph; Calhoun, Ronnie

    1992-05-01

    The integrated radiance throughput model is discussed that encompasses the trajectory dynamics and the atmospheric interactions involved in hypersonic endoatmospheric interceptors for strategic and theater missile defenses. The model is intended for medium fidelity performance analysis to enable overall systems performance evaluations and trades. The model is implemented to provide rapid results for numerous mission scenarios and geometries using various emerging window and seeker technologies.

  20. Smart low flow signature metrics for an improved overall performance evaluation of hydrological models

    NASA Astrophysics Data System (ADS)

    Pfannerstill, Matthias; Guse, Björn; Fohrer, Nicola

    2014-03-01

    Hydrological models have to be calibrated accurately to provide reasonable model results. For a concise model evaluation, the different phases of the hydrograph have to be considered in multi-metric frameworks with appropriate performance metrics. Low and high flows need to be reproduced simultaneously without neglecting the other phases of the hydrograph. In this paper, we highlight the relevance of very low and low flows with separate performance metrics. We present a multi-metric evaluation framework to identify calibration runs, which represent the different phases of the hydrograph precisely. A stepwise evaluation was done with commonly used statistical performance metrics (Nash-Sutcliffe, percent bias) and signature metrics, which are based on the flow duration curve (FDC). In order to consider a fairly balanced evaluation between high and low flow phases, we divided the flow duration curve into segments of high, medium and low flow phases, and additionally into very high and very low flow phases. The model performance in these segments was evaluated separately with the root mean square error (RMSE). Our results show that this evaluation method leads to an improved selection of good calibration runs to enhance the overall model performance by the refined segmentation of FDC. By combining performance metrics for high flow conditions with low flow conditions, this study demonstrates the challenge of calibrating a model with a satisfactory performance in high and low phases simultaneously. Consequently, we conclude that an additional performance metric for very low flows should be included in model analyzes to improve the overall performance in all phases of the hydrograph.

  1. The third phase of AQMEII: evaluation strategy and multi-model performance analysis

    NASA Astrophysics Data System (ADS)

    Solazzo, Efisio; Galmarini, Stefano; Hogrefe, Christian

    2016-04-01

    AQMEII (Air Quality Model Evaluation International Initiative) is an extraordinary effort promoting policy-relevant research on regional air quality model evaluation across the European and North American atmospheric modelling communities, providing the ideal platform for advancing the evaluation of air quality models at the regional scale. This study presents a comprehensive overview of the multi-model evaluation results achieved in the ongoing third phase of AQMEII. Sixteen regional-scale chemistry transport modelling systems have simulated the air quality for the year 2010 over the two continental areas of Europe and North America, providing pollutant concentration values at the surface as well as vertical profiles. The performance of the modelling systems have been evaluated against observational data for ozone, CO, NO2, PM10, PM2.5, wind speed and temperature, offering a valuable opportunity to learn about the models' behaviour by performing model-to-model and model-to-measurement comparisons. We make use of the error apportionment strategy, a novel approach to model evaluation developed within AQMEII that combines elements of operational and diagnostic evaluation. This method apportions the model error to its spectral components, thereby identifying the space/timescale at which it is most relevant and, when possible, to infer which process/es could have generated it. We investigate the deviation between modelled and observed time series of pollutants through a revised formulation for breaking down the mean square error into bias, variance, and the minimum achievable MSE (mMSE). Each of the error components is analysed independently and apportioned to specific processes based on the corresponding timescale (long scale, synoptic, diurnal, and intra-day). Compared to a conventional operational evaluation approach, the new method allows for a more precise identification of where each portion of the model error predominantly occurs. Information about the nature of

  2. Validating the ACE Model for Evaluating Student Performance Using a Teaching-Learning Process Based on Computational Modeling Systems

    ERIC Educational Resources Information Center

    Louzada, Alexandre Neves; Elia, Marcos da Fonseca; Sampaio, Fábio Ferrentini; Vidal, Andre Luiz Pestana

    2014-01-01

    The aim of this work is to adapt and test, in a Brazilian public school, the ACE model proposed by Borkulo for evaluating student performance as a teaching-learning process based on computational modeling systems. The ACE model is based on different types of reasoning involving three dimensions. In addition to adapting the model and introducing…

  3. Optical modeling and physical performances evaluations for the JT-60SA ECRF antenna

    SciTech Connect

    Platania, P. Figini, L.; Farina, D.; Micheletti, D.; Moro, A.; Sozzi, C.; Isayama, A.; Kobayashi, T.; Moriyama, S.

    2015-12-10

    The purpose of this work is the optical modeling and physical performances evaluations of the JT-60SA ECRF launcher system. The beams have been simulated with the electromagnetic code GRASP® and used as input for ECCD calculations performed with the beam tracing code GRAY, capable of modeling propagation, absorption and current drive of an EC Gaussion beam with general astigmatism. Full details of the optical analysis has been taken into account to model the launched beams. Inductive and advanced reference scenarios has been analysed for physical evaluations in the full poloidal and toroidal steering ranges for two slightly different layouts of the launcher system.

  4. Optical modeling and physical performances evaluations for the JT-60SA ECRF antenna

    NASA Astrophysics Data System (ADS)

    Platania, P.; Figini, L.; Farina, D.; Isayama, A.; Kobayashi, T.; Micheletti, D.; Moriyama, S.; Moro, A.; Sozzi, C.

    2015-12-01

    The purpose of this work is the optical modeling and physical performances evaluations of the JT-60SA ECRF launcher system. The beams have been simulated with the electromagnetic code GRASP® and used as input for ECCD calculations performed with the beam tracing code GRAY, capable of modeling propagation, absorption and current drive of an EC Gaussion beam with general astigmatism. Full details of the optical analysis has been taken into account to model the launched beams. Inductive and advanced reference scenarios has been analysed for physical evaluations in the full poloidal and toroidal steering ranges for two slightly different layouts of the launcher system.

  5. A mixed integer bi-level DEA model for bank branch performance evaluation by Stackelberg approach

    NASA Astrophysics Data System (ADS)

    Shafiee, Morteza; Lotfi, Farhad Hosseinzadeh; Saleh, Hilda; Ghaderi, Mehdi

    2016-11-01

    One of the most complicated decision making problems for managers is the evaluation of bank performance, which involves various criteria. There are many studies about bank efficiency evaluation by network DEA in the literature review. These studies do not focus on multi-level network. Wu (Eur J Oper Res 207:856-864, 2010) proposed a bi-level structure for cost efficiency at the first time. In this model, multi-level programming and cost efficiency were used. He used a nonlinear programming to solve the model. In this paper, we have focused on multi-level structure and proposed a bi-level DEA model. We then used a liner programming to solve our model. In other hand, we significantly improved the way to achieve the optimum solution in comparison with the work by Wu (2010) by converting the NP-hard nonlinear programing into a mixed integer linear programming. This study uses a bi-level programming data envelopment analysis model that embodies internal structure with Stackelberg-game relationships to evaluate the performance of banking chain. The perspective of decentralized decisions is taken in this paper to cope with complex interactions in banking chain. The results derived from bi-level programming DEA can provide valuable insights and detailed information for managers to help them evaluate the performance of the banking chain as a whole using Stackelberg-game relationships. Finally, this model was applied in the Iranian bank to evaluate cost efficiency.

  6. A model for evaluating the social performance of construction waste management.

    PubMed

    Yuan, Hongping

    2012-06-01

    It has been determined by existing literature that a lot of research efforts have been made to the economic performance of construction waste management (CWM), but less attention is paid to investigation of the social performance of CWM. This study therefore attempts to develop a model for quantitatively evaluating the social performance of CWM by using a system dynamics (SD) approach. Firstly, major variables affecting the social performance of CWM are identified and a holistic system for assessing the social performance of CWM is formulated in line with feedback relationships underlying these variables. The developed system is then converted into a SD model through the software iThink. An empirical case study is finally conducted to demonstrate application of the model. Results of model validation indicate that the model is robust and reasonable to reflect the situation of the real system under study. Findings of the case study offer helpful insights into effectively promoting the social performance of CWM of the project investigated. Furthermore, the model exhibits great potential to function as an experimental platform for dynamically evaluating effects of management measures on improving the social performance of CWM of construction projects.

  7. Modeling and performance evaluation of flexible manufacturing systems using Petri nets

    SciTech Connect

    Callotta, M.P.; Cimenez, C.; Tazza, M.

    1996-12-31

    A timed Petri net approach is used to model resource allocation-utilization-release patterns for performance evaluation. First, simple resource utilization sequences are derived from a directed graph representing the process plan of parts. Second, the place-transitions sequences are connected introducing places whose marking models the resources needed to perform the manufacturing operation indicated in the process plan. Time is introduced as a permanence time of tokens at the place-transition sequence, modeling the utilization time of resources. The corresponding model leads to a simultaneous resource possession problem. Finally, flow equations for the description of the quantitative behavior of the resulting timed Petri net are presented. A major conclusion of the paper is that performance evaluation can be adequately abstracted and analytically solved, in a simple way, even in presence of complicating factors like resource sharing and routing flexibility in process plans.

  8. Assessing the quality of classification models: Performance measures and evaluation procedures

    NASA Astrophysics Data System (ADS)

    Cichosz, Paweł

    2011-06-01

    This article systematically reviews techniques used for the evaluation of classification models and provides guidelines for their proper application. This includes performance measures assessing the model's performance on a particular dataset and evaluation procedures applying the former to appropriately selected data subsets to produce estimates of their expected values on new data. Their common purpose is to assess model generalization capabilities, which are crucial for judging the applicability and usefulness of both classification and any other data mining models. The review presented in this article is expected to be sufficiently in-depth and complete for most practical needs, while remaining clear and easy to follow with little prior knowledge. Issues that receive special attention include incorporating instance weights to performance measures, combining the same set of evaluation procedures with arbitrary performance measures, and avoiding pitfalls related to separating data subsets used for evaluation from those used for model creation. With the classification task unquestionably being one of the central data mining tasks and the vastly increasing number of data mining applications — not only in business, but also in engineering and research — this is expected to be interesting and useful for a wide audience. All presented techniques are accompanied by simple R language implementations and usage examples, which — whereas created to serve the illustration purpose mostly — can be actually used in practice.

  9. Assessing the quality of classification models: Performance measures and evaluation procedures

    NASA Astrophysics Data System (ADS)

    Cichosz, Paweł

    2011-06-01

    This article systematically reviews techniques used for the evaluation of classification models and provides guidelines for their proper application. This includes performance measures assessing the model's performance on a particular dataset and evaluation procedures applying the former to appropriately selected data subsets to produce estimates of their expected values on new data. Their common purpose is to assess model generalization capabilities, which are crucial for judging the applicability and usefulness of both classification and any other data mining models. The review presented in this article is expected to be sufficiently in-depth and complete for most practical needs, while remaining clear and easy to follow with little prior knowledge. Issues that receive special attention include incorporating instance weights to performance measures, combining the same set of evaluation procedures with arbitrary performance measures, and avoiding pitfalls related to separating data subsets used for evaluation from those used for model creation. With the classification task unquestionably being one of the central data mining tasks and the vastly increasing number of data mining applications — not only in business, but also in engineering and research — this is expected to be interesting and useful for a wide audience. All presented techniques are accompanied by simple R language implementations and usage examples, which — whereas created to serve the illustration purpose mostly — can be actually used in practice.

  10. Important Physiological Parameters and Physical Activity Data for Evaluating Exposure Modeling Performance: a Synthesis

    EPA Science Inventory

    The purpose of this report is to develop a database of physiological parameters needed for understanding and evaluating performance of the APEX and SHEDS exposure/intake dose rate model used by the Environmental Protection Agency (EPA) as part of its regulatory activities. The A...

  11. Important Physiological Parameters and Physical Activity Data for Evaluating Exposure Modeling Performance: a Synthesis

    EPA Science Inventory

    The purpose of this report is to develop a database of physiological parameters needed for understanding and evaluating performance of the APEX and SHEDS exposure/intake dose rate model used by the Environmental Protection Agency (EPA) as part of its regulatory activities. The A...

  12. Stochastic performance modeling and evaluation of obstacle detectability with imaging range sensors

    NASA Technical Reports Server (NTRS)

    Matthies, Larry; Grandjean, Pierrick

    1993-01-01

    Statistical modeling and evaluation of the performance of obstacle detection systems for Unmanned Ground Vehicles (UGVs) is essential for the design, evaluation, and comparison of sensor systems. In this report, we address this issue for imaging range sensors by dividing the evaluation problem into two levels: quality of the range data itself and quality of the obstacle detection algorithms applied to the range data. We review existing models of the quality of range data from stereo vision and AM-CW LADAR, then use these to derive a new model for the quality of a simple obstacle detection algorithm. This model predicts the probability of detecting obstacles and the probability of false alarms, as a function of the size and distance of the obstacle, the resolution of the sensor, and the level of noise in the range data. We evaluate these models experimentally using range data from stereo image pairs of a gravel road with known obstacles at several distances. The results show that the approach is a promising tool for predicting and evaluating the performance of obstacle detection with imaging range sensors.

  13. Source term model evaluations for the low-level waste facility performance assessment

    SciTech Connect

    Yim, M.S.; Su, S.I.

    1995-12-31

    The estimation of release of radionuclides from various waste forms to the bottom boundary of the waste disposal facility (source term) is one of the most important aspects of LLW facility performance assessment. In this work, several currently used source term models are comparatively evaluated for the release of carbon-14 based on a test case problem. The models compared include PRESTO-EPA-CPG, IMPACTS, DUST and NEFTRAN-II. Major differences in assumptions and approaches between the models are described and key parameters are identified through sensitivity analysis. The source term results from different models are compared and other concerns or suggestions are discussed.

  14. Evaluating Nextgen Closely Spaced Parallel Operations Concepts with Validated Human Performance Models: Flight Deck Guidelines

    NASA Technical Reports Server (NTRS)

    Hooey, Becky Lee; Gore, Brian Francis; Mahlstedt, Eric; Foyle, David C.

    2013-01-01

    The objectives of the current research were to develop valid human performance models (HPMs) of approach and land operations; use these models to evaluate the impact of NextGen Closely Spaced Parallel Operations (CSPO) on pilot performance; and draw conclusions regarding flight deck display design and pilot-ATC roles and responsibilities for NextGen CSPO concepts. This document presents guidelines and implications for flight deck display designs and candidate roles and responsibilities. A companion document (Gore, Hooey, Mahlstedt, & Foyle, 2013) provides complete scenario descriptions and results including predictions of pilot workload, visual attention and time to detect off-nominal events.

  15. Performance evaluation of four grid-based dispersion models in complex terrain

    NASA Astrophysics Data System (ADS)

    Tesche, T. W.; Haney, J. L.; Morris, R. E.

    Four numerical grid-based dispersion models (Mathew/ADPIC, SMOG, Hybrid, and 2DFLOW) were adapted to the Geysers-Calistoga geothermal area in northern California. The models were operated using five intensive meteorological and tracer diffusion data sets collected during the 1981 ASCOT field experiment at the Geysers (three nocturnal drainage and two daytime valley stagnation episodes). The 2DFLOW and Hybrid Models were found to perform best for drainage and limited-mixing conditions, respectively. These two models were subsequently evaluated using data from five 1980 ASCOT drainage experiments. The Hybrid Model was also tested using data from nine limited-mixing and downwash tracer experiments performed at the Geysers prior to the ASCOT program. Overall, the 2DFLOW Model performed best for drainage flow conditions, whereas the Hybrid Model performed best for valley stagnation (limited-mixing) and moderate crossridge wind conditions. To aid new source review studies at the Geysers, a series of source-receptor transfer matrices were generated for several different meteorological regimes under a variety of emission scenarios using the Hybrid Model. These matrices supply ready estimates of cumulative hydrogen sulfide impacts from various geothermal sources in the region.

  16. Wind farms providing secondary frequency regulation: Evaluating the performance of model-based receding horizon control

    NASA Astrophysics Data System (ADS)

    Shapiro, Carl R.; Meyers, Johan; Meneveau, Charles; Gayme, Dennice F.

    2016-09-01

    We investigate the use of wind farms to provide secondary frequency regulation for a power grid. Our approach uses model-based receding horizon control of a wind farm that is tested using a large eddy simulation (LES) framework. In order to enable real-time implementation, the control actions are computed based on a time-varying one-dimensional wake model. This model describes wake advection and interactions, both of which play an important role in wind farm power production. This controller is implemented in an LES model of an 84-turbine wind farm represented by actuator disk turbine models. Differences between the velocities at each turbine predicted by the wake model and measured in LES are used for closed-loop feedback. The controller is tested on two types of regulation signals, “RegA” and “RegD”, obtained from PJM, an independent system operator in the eastern United States. Composite performance scores, which are used by PJM to qualify plants for regulation, are used to evaluate the performance of the controlled wind farm. Our results demonstrate that the controlled wind farm consistently performs well, passing the qualification threshold for all fastacting RegD signals. For the RegA signal, which changes over slower time scales, the controlled wind farm's average performance surpasses the threshold, but further work is needed to enable the controlled system to achieve qualifying performance all of the time.

  17. Towards a benchmark simulation model for plant-wide control strategy performance evaluation of WWTPs.

    PubMed

    Jeppsson, U; Rosen, C; Alex, J; Copp, J; Gernaey, K V; Pons, M N; Vanrolleghem, P A

    2006-01-01

    The COST/IWA benchmark simulation model has been available for seven years. Its primary purpose has been to create a platform for control strategy benchmarking of activated sludge processes. The fact that the benchmark has resulted in more than 100 publications, not only in Europe but also worldwide, demonstrates the interest in such a tool within the research community In this paper, an extension of the benchmark simulation model no 1 (BSM1) is proposed. This extension aims at facilitating control strategy development and performance evaluation at a plant-wide level and, consequently, includes both pre-treatment of wastewater as well as the processes describing sludge treatment. The motivation for the extension is the increasing interest and need to operate and control wastewater treatment systems not only at an individual process level but also on a plant-wide basis. To facilitate the changes, the evaluation period has been extended to one year. A prolonged evaluation period allows for long-term control strategies to be assessed and enables the use of control handles that cannot be evaluated in a realistic fashion in the one-week BSM1 evaluation period. In the paper, the extended plant layout is proposed and the new suggested process models are described briefly. Models for influent file design, the benchmarking procedure and the evaluation criteria are also discussed. And finally, some important remaining topics, for which consensus is required, are identified.

  18. Evaluating stream health based environmental justice model performance at different spatial scales

    NASA Astrophysics Data System (ADS)

    Daneshvar, Fariborz; Nejadhashemi, A. Pouyan; Zhang, Zhen; Herman, Matthew R.; Shortridge, Ashton; Marquart-Pyatt, Sandra

    2016-07-01

    This study evaluated the effects of spatial resolution on environmental justice analysis concerning stream health. The Saginaw River Basin in Michigan was selected since it is an area of concern in the Great Lakes basin. Three Bayesian Conditional Autoregressive (CAR) models (ordinary regression, weighted regression and spatial) were developed for each stream health measure based on 17 socioeconomic and physiographical variables at three census levels. For all stream health measures, spatial models had better performance compared to the two non-spatial ones at the census tract and block group levels. Meanwhile no spatial dependency was found at the county level. Multilevel Bayesian CAR models were also developed to understand the spatial dependency at the three levels. Results showed that considering level interactions improved models' prediction. Residual plots also showed that models developed at the block group and census tract (in contrary to county level models) are able to capture spatial variations.

  19. MODELING AND PERFORMANCE EVALUATION FOR AVIATION SECURITY CARGO INSPECTION QUEUING SYSTEM

    SciTech Connect

    Allgood, Glenn O; Olama, Mohammed M; Rose, Terri A; Brumback, Daryl L

    2009-01-01

    Beginning in 2010, the U.S. will require that all cargo loaded in passenger aircraft be inspected. This will require more efficient processing of cargo and will have a significant impact on the inspection protocols and business practices of government agencies and the airlines. In this paper, we conduct performance evaluation study for an aviation security cargo inspection queuing system for material flow and accountability. The overall performance of the aviation security cargo inspection system is computed, analyzed, and optimized for the different system dynamics. Various performance measures are considered such as system capacity, residual capacity, and throughput. These metrics are performance indicators of the system s ability to service current needs and response capacity to additional requests. The increased physical understanding resulting from execution of the queuing model utilizing these vetted performance measures will reduce the overall cost and shipping delays associated with the new inspection requirements.

  20. Evaluating Performance of Components

    NASA Technical Reports Server (NTRS)

    Katz, Daniel; Tisdale, Edwin; Norton, Charles

    2004-01-01

    Parallel Component Performance Benchmarks is a computer program developed to aid the evaluation of the Common Component Architecture (CCA) - a software architecture, based on a component model, that was conceived to foster high-performance computing, including parallel computing. More specifically, this program compares the performances (principally by measuring computing times) of componentized versus conventional versions of the Parallel Pyramid 2D Adaptive Mesh Refinement library - a software library that is used to generate computational meshes for solving physical problems and that is typical of software libraries in use at NASA s Jet Propulsion Laboratory.

  1. Modeling and Performance Evaluation of Backoff Misbehaving Nodes in CSMA/CA Networks

    DTIC Science & Technology

    2011-08-01

    Modeling and Performance Evaluation of Backoff Misbehaving Nodes in CSMA/CA Networks Zhuo Lu, Student Member, IEEE, Wenye Wang, Senior Member, IEEE...and Cliff Wang Abstract—Backoff misbehavior , in which a wireless node deliberately manipulates its backoff time, can induce significant network... misbehavior , little attention has been focused on quantifying the gain of backoff misbehaviors . In this paper, to assess the gain that misbehaving nodes can

  2. Review and evaluation of performance measures for survival prediction models in external validation settings.

    PubMed

    Rahman, M Shafiqur; Ambler, Gareth; Choodari-Oskooei, Babak; Omar, Rumana Z

    2017-04-18

    When developing a prediction model for survival data it is essential to validate its performance in external validation settings using appropriate performance measures. Although a number of such measures have been proposed, there is only limited guidance regarding their use in the context of model validation. This paper reviewed and evaluated a wide range of performance measures to provide some guidelines for their use in practice. An extensive simulation study based on two clinical datasets was conducted to investigate the performance of the measures in external validation settings. Measures were selected from categories that assess the overall performance, discrimination and calibration of a survival prediction model. Some of these have been modified to allow their use with validation data, and a case study is provided to describe how these measures can be estimated in practice. The measures were evaluated with respect to their robustness to censoring and ease of interpretation. All measures are implemented, or are straightforward to implement, in statistical software. Most of the performance measures were reasonably robust to moderate levels of censoring. One exception was Harrell's concordance measure which tended to increase as censoring increased. We recommend that Uno's concordance measure is used to quantify concordance when there are moderate levels of censoring. Alternatively, Gönen and Heller's measure could be considered, especially if censoring is very high, but we suggest that the prediction model is re-calibrated first. We also recommend that Royston's D is routinely reported to assess discrimination since it has an appealing interpretation. The calibration slope is useful for both internal and external validation settings and recommended to report routinely. Our recommendation would be to use any of the predictive accuracy measures and provide the corresponding predictive accuracy curves. In addition, we recommend to investigate the characteristics

  3. Seasonal versus Episodic Performance Evaluation for an Eulerian Photochemical Air Quality Model

    SciTech Connect

    Jin, Ling; Brown, Nancy J.; Harley, Robert A.; Bao, Jian-Wen; Michelson, Sara A; Wilczak, James M

    2010-04-16

    This study presents detailed evaluation of the seasonal and episodic performance of the Community Multiscale Air Quality (CMAQ) modeling system applied to simulate air quality at a fine grid spacing (4 km horizontal resolution) in central California, where ozone air pollution problems are severe. A rich aerometric database collected during the summer 2000 Central California Ozone Study (CCOS) is used to prepare model inputs and to evaluate meteorological simulations and chemical outputs. We examine both temporal and spatial behaviors of ozone predictions. We highlight synoptically driven high-ozone events (exemplified by the four intensive operating periods (IOPs)) for evaluating both meteorological inputs and chemical outputs (ozone and its precursors) and compare them to the summer average. For most of the summer days, cross-domain normalized gross errors are less than 25% for modeled hourly ozone, and normalized biases are between {+-}15% for both hourly and peak (1 h and 8 h) ozone. The domain-wide aggregated metrics indicate similar performance between the IOPs and the whole summer with respect to predicted ozone and its precursors. Episode-to-episode differences in ozone predictions are more pronounced at a subregional level. The model performs consistently better in the San Joaquin Valley than other air basins, and episodic ozone predictions there are similar to the summer average. Poorer model performance (normalized peak ozone biases <-15% or >15%) is found in the Sacramento Valley and the Bay Area and is most noticeable in episodes that are subject to the largest uncertainties in meteorological fields (wind directions in the Sacramento Valley and timing and strength of onshore flow in the Bay Area) within the boundary layer.

  4. The Third Phase of AQMEII: Evaluation Strategy and Multi-Model Performance Analysis

    EPA Science Inventory

    AQMEII (Air Quality Model Evaluation International Initiative) is an extraordinary effort promoting policy-relevant research on regional air quality model evaluation across the European and North American atmospheric modelling communities, providing the ideal platform for advanci...

  5. The Third Phase of AQMEII: Evaluation Strategy and Multi-Model Performance Analysis

    EPA Science Inventory

    AQMEII (Air Quality Model Evaluation International Initiative) is an extraordinary effort promoting policy-relevant research on regional air quality model evaluation across the European and North American atmospheric modelling communities, providing the ideal platform for advanci...

  6. Evaluation of nonlinear chromatographic performance by frontal analysis using a simple multi-plate mathematical model.

    PubMed

    Hao, Weiqiang; Wang, Junde

    2005-01-21

    A multi-plate (MP) mathematical model was proposed by frontal analysis to evaluate nonlinear chromatographic performance. One of its advantages is that the parameters may be easily calculated from experimental data. Moreover, there is a good correlation between it and the equilibrium-dispersive (E-D) or Thomas models. This shows that it can well accommodate both types of band broadening that is comprised of either diffusion-dominated processes or kinetic sorption processes. The MP model can well describe experimental breakthrough curves that were obtained from membrane affinity chromatography and column reversed-phase liquid chromatography. Furthermore, the coefficients of mass transfer may be calculated according to the relationship between the MP model and the E-D or Thomas models.

  7. Modeling, control design, and performance evaluation of high speed ground vehicle dynamics

    SciTech Connect

    Faye, I.; Kortum, W.; Schwartz, W. )

    1989-01-01

    The interest in developing high speed ground transportation systems is one reason for directing attention to the modeling and simulation of the dynamic behavior of vehicle systems. Rail-guided vehicles; i.e., conventional railways, advanced railway systems, or magnetically levitated trains, represent the practical implementation of such ground transportation systems. One computer program that is well suited for the analysis of rail-guided vehicles is the multibody program MEDYNA. This paper demonstrates the application of MEDYNA for control law design and to performance evaluation of such advanced vehicles. A brief description is made of the modeling requirements of magnetically levitated systems, along with a summary of some of the related capabilities and computational methods of MEDNYA. As a case study, analysis of a vehicle based on the German Transrapid system is presented. System matrices of a simplified vehicle model are established and control design is performed with the aid of MATLAB. Performance evaluation is studied with a complex model of the Transrapid vehicle and elastic guideways.

  8. Methodologies for evaluating performance and assessing uncertainty of atmospheric dispersion models

    NASA Astrophysics Data System (ADS)

    Chang, Joseph C.

    This thesis describes methodologies to evaluate the performance and to assess the uncertainty of atmospheric dispersion models, tools that predict the fate of gases and aerosols upon their release into the atmosphere. Because of the large economic and public-health impacts often associated with the use of the dispersion model results, these models should be properly evaluated, and their uncertainty should be properly accounted for and understood. The CALPUFF, HPAC, and VLSTRACK dispersion modeling systems were applied to the Dipole Pride (DP26) field data (˜20 km in scale), in order to demonstrate the evaluation and uncertainty assessment methodologies. Dispersion model performance was found to be strongly dependent on the wind models used to generate gridded wind fields from observed station data. This is because, despite the fact that the test site was a flat area, the observed surface wind fields still showed considerable spatial variability, partly because of the surrounding mountains. It was found that the two components were comparable for the DP26 field data, with variability more important than uncertainty closer to the source, and less important farther away from the source. Therefore, reducing data errors for input meteorology may not necessarily increase model accuracy due to random turbulence. DP26 was a research-grade field experiment, where the source, meteorological, and concentration data were all well-measured. Another typical application of dispersion modeling is a forensic study where the data are usually quite scarce. An example would be the modeling of the alleged releases of chemical warfare agents during the 1991 Persian Gulf War, where the source data had to rely on intelligence reports, and where Iraq had stopped reporting weather data to the World Meteorological Organization since the 1981 Iran-Iraq-war. Therefore the meteorological fields inside Iraq must be estimated by models such as prognostic mesoscale meteorological models, based on

  9. Engineering Process Model for High-Temperature Electrolysis System Performance Evaluation

    SciTech Connect

    Carl M. Stoots; James E. O'Brien; Michael G. McKellar; Grant L. Hawkes

    2005-11-01

    In order to evaluate the potential hydrogen production performance of large-scale High-Temperature Electrolysis (HTE) operations, we have developed an engineering process model at INL using the commercial systems-analysis code HYSYS. Using this code, a detailed process flowsheet has been defined that includes all of the components that would be present in an actual plant such as pumps, compressors, heat exchangers, turbines, and the electrolyzer. Since the electrolyzer is not a standard HYSYS component, a custom one-dimensional electrolyzer model was developed for incorporation into the overall HYSYS process flowsheet. This electrolyzer model allows for the determination of the operating voltage, gas outlet temperatures, and electrolyzer efficiency for any specified inlet gas flow rates, current density, cell active area, and external heat loss or gain. The one-dimensional electrolyzer model was validated by comparison with results obtained from a fully 3-D computational fluid dynamics model developed using FLUENT. This report provides details on the one-dimensional electrolyzer model, the HYSYS process model for a 300 MW HTE plant, and some representative results of parametric studies performed using the HYSYS process model.

  10. Evaluating climate model performance in the tropics with retrievals of water isotopic composition from Aura TES

    NASA Astrophysics Data System (ADS)

    Field, Robert D.; Kim, Daehyun; LeGrande, Allegra N.; Worden, John; Kelley, Maxwell; Schmidt, Gavin A.

    2014-08-01

    We evaluate the NASA Goddard Institute for Space Studies ModelE2 general circulation model over the tropics against water isotope (HDO/H2O) retrievals from the Aura Tropospheric Emission Spectrometer. Observed isotopic distributions are distinct from other observable quantities and can therefore act as an independent constraint. We perform a small ensemble of simulations with physics perturbations to the cumulus and planetary boundary layer schemes. We examine the degree to which model-data agreement could be used to constrain a select group of internal processes in the model, namely, condensate evaporation, entrainment strength, and updraft mass flux. All are difficult to parameterize but exert strong influence over model performance. We find that the water isotope composition is more sensitive to physics changes than precipitation, temperature, or relative humidity in the lower and upper tropical tropospheres. Among the processes considered, this is most closely, and fairly exclusively, related to midtropospheric entrainment strength. Our study indicates that water isotope observations could provide useful constraints on model parameterizations.

  11. Modeling network infrastructure and performance evaluation for PACS: DICOM over ethernet-based TCP/IP

    NASA Astrophysics Data System (ADS)

    Arvanitis, Theodoros N.; Roth, David

    2001-08-01

    Studies of information and process modeling have demonstrated the importance and clinical impact of Picture Archiving and Communication Systems in the efficient operational management of imaging within the clinical setting. The appropriate identification of both clinical and technology requirements for the planning and deployment of such systems is essential to achieve cost-effectiveness in use. The understanding of the complexities of clinically viable network topologies and architectures for PACS can be achieved through realistic simulations and modeling. The purpose of this paper is to provide a methodology for modeling the DICOM session and application layer entities over Ethernet-based TCP/IP, by using the OPNET Modeler, and derive performance evaluation metrics for different PACS network topologies.

  12. Conceptualization of a robust performance assessment and evaluation model for consolidating community water systems.

    PubMed

    Rogers, Jeffrey W; Louis, Garrick E

    2009-02-01

    Community water systems (CWS) face significant competing forces for change from decreasing water resource availability, stricter water quality regulations, decreasing federal subsidies, increasing public scrutiny, decreasing financial health, and increasing infrastructure replacement costs. These competing forces necessitate increasing consolidation responses among financially stressed CWS. Consolidation responses allow financially stressed CWS to increase levels of service by taking advantage of economy of scale benefits, such as eliminating service duplications across administration and operational functions. Consolidation responses also promote improved financial accountability among consolidating CWS, especially when operating as integral subsystems of a larger regional drinking water supply (RDWS) system. The goal of this paper is to propose a conceptual model for robust performance assessment and evaluation (PAE) among consolidating CWS. The objectives of this paper are to conceptualize methods for: (1) consistent performance assessment and (2) uniform summative performance evaluation among consolidating CWS. The expected outcome from implementing robust PAE among consolidating CWS is increased levels of service through transparent benchmarking and improved financial accountability. The proposed robust PAE model provides the basis for constructing decision support system (DSS) tools that estimate efficient solutions for allocating limited financial resources among consolidating CWS. The paper is a significant departure from current CWS PAE approaches in two ways. First, it provides a goal-oriented approach for robust PAE among consolidating CWS. Second, it constructs efficiency-based performance metrics to temporally and spatially monitor the degree of attainment of the RDWS systems' goal.

  13. Evaluation of Blade-Strike Models for Estimating the Biological Performance of Large Kaplan Hydro Turbines

    SciTech Connect

    Deng, Zhiqun; Carlson, Thomas J.; Ploskey, Gene R.; Richmond, Marshall C.

    2005-11-30

    BioIndex testing of hydro-turbines is sought as an analog to the hydraulic index testing conducted on hydro-turbines to optimize their power production efficiency. In BioIndex testing the goal is to identify those operations within the range identified by Index testing where the survival of fish passing through the turbine is maximized. BioIndex testing includes the immediate tailrace region as well as the turbine environment between a turbine's intake trashracks and the exit of its draft tube. The US Army Corps of Engineers and the Department of Energy have been evaluating a variety of means, such as numerical and physical turbine models, to investigate the quality of flow through a hydro-turbine and other aspects of the turbine environment that determine its safety for fish. The goal is to use these tools to develop hypotheses identifying turbine operations and predictions of their biological performance that can be tested at prototype scales. Acceptance of hypotheses would be the means for validation of new operating rules for the turbine tested that would be in place when fish were passing through the turbines. The overall goal of this project is to evaluate the performance of numerical blade strike models as a tool to aid development of testable hypotheses for bioIndexing. Evaluation of the performance of numerical blade strike models is accomplished by comparing predictions of fish mortality resulting from strike by turbine runner blades with observations made using live test fish at mainstem Columbia River Dams and with other predictions of blade strike made using observations of beads passing through a 1:25 scale physical turbine model.

  14. The School Improvement Model: Tailoring a Teacher and Administrator Performance Evaluation System to Meet the Needs of the School Organization.

    ERIC Educational Resources Information Center

    Walker, Retia Scott

    Described here are the planning and development stages of the Teacher Performance Evaluation (TPE) system and the Administrator Performance Evaluation (APE) system that are components of the School Improvement Model project undertaken by schools in Iowa and Minnesota. One goal is an evaluation system tailored to fit the needs of the school…

  15. Performance evaluation of RANS-based turbulence models in simulating a honeycomb heat sink

    NASA Astrophysics Data System (ADS)

    Subasi, Abdussamet; Ozsipahi, Mustafa; Sahin, Bayram; Gunes, Hasan

    2017-07-01

    As well-known, there is not a universal turbulence model that can be used to model all engineering problems. There are specific applications for each turbulence model that make it appropriate to use, and it is vital to select an appropriate model and wall function combination that matches the physics of the problem considered. Therefore, in this study, performance of six well-known Reynolds-Averaged Navier-Stokes ( RANS) based turbulence models which are the Standard k {{-}} ɛ, the Renormalized Group k- ɛ, the Realizable k- ɛ, the Reynolds Stress Model, the k- ω and the Shear Stress Transport k- ω and accompanying wall functions which are the standard, the non-equilibrium and the enhanced are evaluated via 3D simulation of a honeycomb heat sink. The CutCell method is used to generate grid for the part including heat sink called test section while a hexahedral mesh is employed to discretize to inlet and outlet sections. A grid convergence study is conducted for verification process while experimental data and well-known correlations are used to validate the numerical results. Prediction of pressure drop along the test section, mean base plate temperature of the heat sink and temperature at the test section outlet are regarded as a measure of the performance of employed models and wall functions. The results indicate that selection of turbulence models and wall functions has a great influence on the results and, therefore, need to be selected carefully. Hydraulic and thermal characteristics of the honeycomb heat sink can be determined in a reasonable accuracy using RANS- based turbulence models provided that a suitable turbulence model and wall function combination is selected.

  16. Performance evaluation of RANS-based turbulence models in simulating a honeycomb heat sink

    NASA Astrophysics Data System (ADS)

    Subasi, Abdussamet; Ozsipahi, Mustafa; Sahin, Bayram; Gunes, Hasan

    2017-02-01

    As well-known, there is not a universal turbulence model that can be used to model all engineering problems. There are specific applications for each turbulence model that make it appropriate to use, and it is vital to select an appropriate model and wall function combination that matches the physics of the problem considered. Therefore, in this study, performance of six well-known Reynolds-Averaged Navier-Stokes (RANS) based turbulence models which are the Standard k - ɛ, the Renormalized Group k - ɛ, the Realizable k - ɛ, the Reynolds Stress Model, the k - ω and the Shear Stress Transport k - ω and accompanying wall functions which are the standard, the non-equilibrium and the enhanced are evaluated via 3D simulation of a honeycomb heat sink. The CutCell method is used to generate grid for the part including heat sink called test section while a hexahedral mesh is employed to discretize to inlet and outlet sections. A grid convergence study is conducted for verification process while experimental data and well-known correlations are used to validate the numerical results. Prediction of pressure drop along the test section, mean base plate temperature of the heat sink and temperature at the test section outlet are regarded as a measure of the performance of employed models and wall functions. The results indicate that selection of turbulence models and wall functions has a great influence on the results and, therefore, need to be selected carefully. Hydraulic and thermal characteristics of the honeycomb heat sink can be determined in a reasonable accuracy using RANS-based turbulence models provided that a suitable turbulence model and wall function combination is selected.

  17. Performance Evaluation and Modeling Techniques for Parallel Processors. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Dimpsey, Robert Tod

    1992-01-01

    In practice, the performance evaluation of supercomputers is still substantially driven by singlepoint estimates of metrics (e.g., MFLOPS) obtained by running characteristic benchmarks or workloads. With the rapid increase in the use of time-shared multiprogramming in these systems, such measurements are clearly inadequate. This is because multiprogramming and system overhead, as well as other degradations in performance due to time varying characteristics of workloads, are not taken into account. In multiprogrammed environments, multiple jobs and users can dramatically increase the amount of system overhead and degrade the performance of the machine. Performance techniques, such as benchmarking, which characterize performance on a dedicated machine ignore this major component of true computer performance. Due to the complexity of analysis, there has been little work done in analyzing, modeling, and predicting the performance of applications in multiprogrammed environments. This is especially true for parallel processors, where the costs and benefits of multi-user workloads are exacerbated. While some may claim that the issue of multiprogramming is not a viable one in the supercomputer market, experience shows otherwise. Even in recent massively parallel machines, multiprogramming is a key component. It has even been claimed that a partial cause of the demise of the CM2 was the fact that it did not efficiently support time-sharing. In the same paper, Gordon Bell postulates that, multicomputers will evolve to multiprocessors in order to support efficient multiprogramming. Therefore, it is clear that parallel processors of the future will be required to offer the user a time-shared environment with reasonable response times for the applications. In this type of environment, the most important performance metric is the completion of response time of a given application. However, there are a few evaluation efforts addressing this issue.

  18. U1108 performance model

    NASA Technical Reports Server (NTRS)

    Trachta, G.

    1976-01-01

    A model of Univac 1108 work flow has been developed to assist in performance evaluation studies and configuration planning. Workload profiles and system configurations are parameterized for ease of experimental modification. Outputs include capacity estimates and performance evaluation functions. The U1108 system is conceptualized as a service network; classical queueing theory is used to evaluate network dynamics.

  19. Evaluation of the performance of smoothing functions in generalized additive models for spatial variation in disease.

    PubMed

    Siangphoe, Umaporn; Wheeler, David C

    2015-01-01

    Generalized additive models (GAMs) with bivariate smoothing functions have been applied to estimate spatial variation in risk for many types of cancers. Only a handful of studies have evaluated the performance of smoothing functions applied in GAMs with regard to different geographical areas of elevated risk and different risk levels. This study evaluates the ability of different smoothing functions to detect overall spatial variation of risk and elevated risk in diverse geographical areas at various risk levels using a simulation study. We created five scenarios with different true risk area shapes (circle, triangle, linear) in a square study region. We applied four different smoothing functions in the GAMs, including two types of thin plate regression splines (TPRS) and two versions of locally weighted scatterplot smoothing (loess). We tested the null hypothesis of constant risk and detected areas of elevated risk using analysis of deviance with permutation methods and assessed the performance of the smoothing methods based on the spatial detection rate, sensitivity, accuracy, precision, power, and false-positive rate. The results showed that all methods had a higher sensitivity and a consistently moderate-to-high accuracy rate when the true disease risk was higher. The models generally performed better in detecting elevated risk areas than detecting overall spatial variation. One of the loess methods had the highest precision in detecting overall spatial variation across scenarios and outperformed the other methods in detecting a linear elevated risk area. The TPRS methods outperformed loess in detecting elevated risk in two circular areas.

  20. Evaluation of the Performance of Smoothing Functions in Generalized Additive Models for Spatial Variation in Disease

    PubMed Central

    Siangphoe, Umaporn; Wheeler, David C.

    2015-01-01

    Generalized additive models (GAMs) with bivariate smoothing functions have been applied to estimate spatial variation in risk for many types of cancers. Only a handful of studies have evaluated the performance of smoothing functions applied in GAMs with regard to different geographical areas of elevated risk and different risk levels. This study evaluates the ability of different smoothing functions to detect overall spatial variation of risk and elevated risk in diverse geographical areas at various risk levels using a simulation study. We created five scenarios with different true risk area shapes (circle, triangle, linear) in a square study region. We applied four different smoothing functions in the GAMs, including two types of thin plate regression splines (TPRS) and two versions of locally weighted scatterplot smoothing (loess). We tested the null hypothesis of constant risk and detected areas of elevated risk using analysis of deviance with permutation methods and assessed the performance of the smoothing methods based on the spatial detection rate, sensitivity, accuracy, precision, power, and false-positive rate. The results showed that all methods had a higher sensitivity and a consistently moderate-to-high accuracy rate when the true disease risk was higher. The models generally performed better in detecting elevated risk areas than detecting overall spatial variation. One of the loess methods had the highest precision in detecting overall spatial variation across scenarios and outperformed the other methods in detecting a linear elevated risk area. The TPRS methods outperformed loess in detecting elevated risk in two circular areas. PMID:25983545

  1. Energy harvesting from the discrete gust response of a piezoaeroelastic wing: Modeling and performance evaluation

    NASA Astrophysics Data System (ADS)

    Xiang, Jinwu; Wu, Yining; Li, Daochun

    2015-05-01

    The objective of this paper is to investigate energy harvesting from the unfavorable gust response of a piezoelectric wing. An aeroelectroelastic model is built for the evaluation and improvement of the harvesting performance. The structural model is built based on the Euler-Bernoulli beam theory. The unsteady aerodynamics, combined with 1-cosine gust load, are obtained from Jones' approximation of the Wagner function. The state-space equation of the aeroelectroelastic model is derived and solved numerically. The energy conversion efficiency and output density are defined to evaluate the harvesting performance. The effects of the sizes and location of the piezoelectric transducers, the load resistance in the external circuit, and the locations of the elastic axis and gravity center axis of the wing are studied, respectively. The results show that, under a given width of the transducers in chordwise direction, there are one thickness of the transducers corresponding to highest conversion efficiency and one smaller optimal value for the output density. The conversion efficiency has an approximate linear relationship with the width. As the transducers are placed at the wing root, a maximum conversion efficiency is reached under a certain length in the spanwise direction, whereas a smaller length helps reaching a larger output density. One optimal resistance is found to maximize the conversion efficiency. The rearward shift of either the elastic axis or gravity center axis improves the energy output while reducing the conversion efficiency.

  2. A diagram for evaluating multiple aspects of model performance in simulating vector fields

    NASA Astrophysics Data System (ADS)

    Xu, Zhongfeng; Hou, Zhaolu; Han, Ying; Guo, Weidong

    2016-12-01

    Vector quantities, e.g., vector winds, play an extremely important role in climate systems. The energy and water exchanges between different regions are strongly dominated by wind, which in turn shapes the regional climate. Thus, how well climate models can simulate vector fields directly affects model performance in reproducing the nature of a regional climate. This paper devises a new diagram, termed the vector field evaluation (VFE) diagram, which is a generalized Taylor diagram and able to provide a concise evaluation of model performance in simulating vector fields. The diagram can measure how well two vector fields match each other in terms of three statistical variables, i.e., the vector similarity coefficient, root mean square length (RMSL), and root mean square vector difference (RMSVD). Similar to the Taylor diagram, the VFE diagram is especially useful for evaluating climate models. The pattern similarity of two vector fields is measured by a vector similarity coefficient (VSC) that is defined by the arithmetic mean of the inner product of normalized vector pairs. Examples are provided, showing that VSC can identify how close one vector field resembles another. Note that VSC can only describe the pattern similarity, and it does not reflect the systematic difference in the mean vector length between two vector fields. To measure the vector length, RMSL is included in the diagram. The third variable, RMSVD, is used to identify the magnitude of the overall difference between two vector fields. Examples show that the VFE diagram can clearly illustrate the extent to which the overall RMSVD is attributed to the systematic difference in RMSL and how much is due to the poor pattern similarity.

  3. Performance Evaluation of Public Hospital Information Systems by the Information System Success Model

    PubMed Central

    Cho, Kyoung Won; Bae, Sung-Kwon; Ryu, Ji-Hye; Kim, Kyeong Na; An, Chang-Ho

    2015-01-01

    Objectives This study was to evaluate the performance of the newly developed information system (IS) implemented on July 1, 2014 at three public hospitals in Korea. Methods User satisfaction scores of twelve key performance indicators of six IS success factors based on the DeLone and McLean IS Success Model were utilized to evaluate IS performance before and after the newly developed system was introduced. Results All scores increased after system introduction except for the completeness of medical records and impact on the clinical environment. The relationships among six IS factors were also analyzed to identify the important factors influencing three IS success factors (Intention to Use, User Satisfaction, and Net Benefits). All relationships were significant except for the relationships among Service Quality, Intention to Use, and Net Benefits. Conclusions The results suggest that hospitals should not only focus on systems and information quality; rather, they should also continuously improve service quality to improve user satisfaction and eventually reach full the potential of IS performance. PMID:25705557

  4. Measuring Information Security Performance with 10 by 10 Model for Holistic State Evaluation.

    PubMed

    Bernik, Igor; Prislan, Kaja

    Organizations should measure their information security performance if they wish to take the right decisions and develop it in line with their security needs. Since the measurement of information security is generally underdeveloped in practice and many organizations find the existing recommendations too complex, the paper presents a solution in the form of a 10 by 10 information security performance measurement model. The model-ISP 10×10M is composed of ten critical success factors, 100 key performance indicators and 6 performance levels. Its content was devised on the basis of findings presented in the current research studies and standards, while its structure results from an empirical research conducted among information security professionals from Slovenia. Results of the study show that a high level of information security performance is mostly dependent on measures aimed at managing information risks, employees and information sources, while formal and environmental factors have a lesser impact. Experts believe that information security should evolve systematically, where it's recommended that beginning steps include technical, logical and physical security controls, while advanced activities should relate predominantly strategic management activities. By applying the proposed model, organizations are able to determine the actual level of information security performance based on the weighted indexing technique. In this manner they identify the measures they ought to develop in order to improve the current situation. The ISP 10×10M is a useful tool for conducting internal system evaluations and decision-making. It may also be applied to a larger sample of organizations in order to determine the general state-of-play for research purposes.

  5. Unified performance evaluation of health centers with integrated model of data envelopment analysis and bargaining game.

    PubMed

    Jahangoshai Rezaee, Mustafa; Moini, Alireza; Haji-Ali Asgari, Fatema

    2012-12-01

    This paper introduces a new integrated approach to measure unified efficiency of the healthcare systems. Health centers as an important part of the healthcare systems are considered for evaluation. For this purpose, we define two categories of inputs to measure performance of health centers based on medical human resources and characteristics of spatial information by using geographic information system (GIS). Catching the balance in the spatial distribution of populations and services is one of the main problems in health centers evaluation. On the other hand, data envelopment analysis (DEA) is widely applied for measuring efficiency of the healthcare systems. But, the conventional DEA models may fail to integrated several categories of measures. In this paper, DEA and bargaining game model are integrated for evaluation of health centers. In other words, two categories of measures are used to measure unified efficiency for each health center in the competitive environment. Two models according to constant return to scale (CRS) and variable return to scale (VRS) assumptions are developed. The case study of health centers under supervising of Tehran university of medical sciences (TMUS) is presented to show the abilities of the proposed approach.

  6. Integrating Soft Set Theory and Fuzzy Linguistic Model to Evaluate the Performance of Training Simulation Systems

    PubMed Central

    Chang, Kuei-Hu; Chang, Yung-Chia; Chain, Kai; Chung, Hsiang-Yu

    2016-01-01

    The advancement of high technologies and the arrival of the information age have caused changes to the modern warfare. The military forces of many countries have replaced partially real training drills with training simulation systems to achieve combat readiness. However, considerable types of training simulation systems are used in military settings. In addition, differences in system set up time, functions, the environment, and the competency of system operators, as well as incomplete information have made it difficult to evaluate the performance of training simulation systems. To address the aforementioned problems, this study integrated analytic hierarchy process, soft set theory, and the fuzzy linguistic representation model to evaluate the performance of various training simulation systems. Furthermore, importance–performance analysis was adopted to examine the influence of saving costs and training safety of training simulation systems. The findings of this study are expected to facilitate applying military training simulation systems, avoiding wasting of resources (e.g., low utility and idle time), and providing data for subsequent applications and analysis. To verify the method proposed in this study, the numerical examples of the performance evaluation of training simulation systems were adopted and compared with the numerical results of an AHP and a novel AHP-based ranking technique. The results verified that not only could expert-provided questionnaire information be fully considered to lower the repetition rate of performance ranking, but a two-dimensional graph could also be used to help administrators allocate limited resources, thereby enhancing the investment benefits and training effectiveness of a training simulation system. PMID:27598390

  7. Integrating Soft Set Theory and Fuzzy Linguistic Model to Evaluate the Performance of Training Simulation Systems.

    PubMed

    Chang, Kuei-Hu; Chang, Yung-Chia; Chain, Kai; Chung, Hsiang-Yu

    2016-01-01

    The advancement of high technologies and the arrival of the information age have caused changes to the modern warfare. The military forces of many countries have replaced partially real training drills with training simulation systems to achieve combat readiness. However, considerable types of training simulation systems are used in military settings. In addition, differences in system set up time, functions, the environment, and the competency of system operators, as well as incomplete information have made it difficult to evaluate the performance of training simulation systems. To address the aforementioned problems, this study integrated analytic hierarchy process, soft set theory, and the fuzzy linguistic representation model to evaluate the performance of various training simulation systems. Furthermore, importance-performance analysis was adopted to examine the influence of saving costs and training safety of training simulation systems. The findings of this study are expected to facilitate applying military training simulation systems, avoiding wasting of resources (e.g., low utility and idle time), and providing data for subsequent applications and analysis. To verify the method proposed in this study, the numerical examples of the performance evaluation of training simulation systems were adopted and compared with the numerical results of an AHP and a novel AHP-based ranking technique. The results verified that not only could expert-provided questionnaire information be fully considered to lower the repetition rate of performance ranking, but a two-dimensional graph could also be used to help administrators allocate limited resources, thereby enhancing the investment benefits and training effectiveness of a training simulation system.

  8. New earth system model for optical performance evaluation of space instruments.

    PubMed

    Ryu, Dongok; Kim, Sug-Whan; Breault, Robert P

    2017-03-06

    In this study, a new global earth system model is introduced for evaluating the optical performance of space instruments. Simultaneous imaging and spectroscopic results are provided using this global earth system model with fully resolved spatial, spectral, and temporal coverage of sub-models of the Earth. The sun sub-model is a Lambertian scattering sphere with a 6-h scale and 295 lines of solar spectral irradiance. The atmospheric sub-model has a 15-layer three-dimensional (3D) ellipsoid structure. The land sub-model uses spectral bidirectional reflectance distribution functions (BRDF) defined by a semi-empirical parametric kernel model. The ocean is modeled with the ocean spectral albedo after subtracting the total integrated scattering of the sun-glint scatter model. A hypothetical two-mirror Cassegrain telescope with a 300-mm-diameter aperture and 21.504 mm × 21.504-mm focal plane imaging instrument is designed. The simulated image results are compared with observational data from HRI-VIS measurements during the EPOXI mission for approximately 24 h from UTC Mar. 18, 2008. Next, the defocus mapping result and edge spread function (ESF) measuring result show that the distance between the primary and secondary mirror increases by 55.498 μm from the diffraction-limited condition. The shift of the focal plane is determined to be 5.813 mm shorter than that of the defocused focal plane, and this result is confirmed through the estimation of point spread function (PSF) measurements. This study shows that the earth system model combined with an instrument model is a powerful tool that can greatly help the development phase of instrument missions.

  9. Explanatory models of muscle performance in acromegaly patients evaluated by knee isokinetic dynamometry: Implications for rehabilitation.

    PubMed

    Lopes, Agnaldo José; Ferreira, Arthur Sá; Walchan, Evelyn Mendes; Soares, Mauricio Santos; Bunn, Priscila Santos; Guimarães, Fernando Silva

    2016-10-01

    To evaluate the effects of demographics and hormonal variations on knee muscle performance in patients with acromegaly and develop explanatory models of peripheral muscle function in these individuals. This was a cross-sectional study in which 53 acromegalics and 27 healthy subjects underwent knee isokinetic dynamometry to evaluate the peak torque value for leg extension at 75°/s (PTE75) and 240°/s (PTE240). Separate multivariable linear regression models for the prediction of PTE75 and PTE240 were tested using variables commonly used as predictors in the clinical setting and other specific variables related to acromegaly. The final prediction model for PTE75 (R(2)=0.888; adjusted R(2)=0.820, SE of bias=16.2Nm, p<0.001) was -0.221×growth hormone+36.791×sexmale=1-27.407×statusactive=1-0.690×age+148.071. The final prediction model for PTE240 (R(2)=0.816; adjusted R(2)=0.805, SE of bias=8.8Nm, p<0.001) was -0.174×growth hormone+12.522×sexmale=1-0.520×age+98.099. In acromegalics, high growth hormone levels, female gender, and older age are associated with reduced muscle strength and endurance. Additionally, active disease negatively affects peripheral muscle strength in these patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Modelling and temporal performances evaluation of networked control systems using (max, +) algebra

    NASA Astrophysics Data System (ADS)

    Ammour, R.; Amari, S.

    2015-01-01

    In this paper, we address the problem of temporal performances evaluation of producer/consumer networked control systems. The aim is to develop a formal method for evaluating the response time of this type of control systems. Our approach consists on modelling, using Petri nets classes, the behaviour of the whole architecture including the switches that support multicast communications used by this protocol. (max, +) algebra formalism is then exploited to obtain analytical formulas of the response time and the maximal and minimal bounds. The main novelty is that our approach takes into account all delays experienced at the different stages of networked automation systems. Finally, we show how to apply the obtained results through an example of networked control system.

  11. Solid rocket booster performance evaluation model. Volume 3: Sample case. [propellant combustion simulation/internal ballistics

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The solid rocket booster performance evaluation model (SRB-11) is used to predict internal ballistics in a sample motor. This motor contains a five segmented grain. The first segment has a 14 pointed star configuration with a web which wraps partially around the forward dome. The other segments are circular in cross-section and are tapered along the interior burning surface. Two of the segments are inhibited on the forward face. The nozzle is not assumed to be submerged. The performance prediction is broken into two simulation parts: the delivered end item specific impulse and the propellant properties which are required as inputs for the internal ballistics module are determined; and the internal ballistics for the entire burn duration of the motor are simulated.

  12. A PERFORMANCE EVALUATION OF THE 2004 RELEASE OF MODELS-3 CMAQ

    EPA Science Inventory

    This performance evaluation compares a full annual simulation (2001) of CMAQ (Version4.4) covering the contiguous United States against monitoring data from four nationwide networks. This effort, which represents one of the most spatially and temporally comprehensive performance...

  13. A PERFORMANCE EVALUATION OF THE 2004 RELEASE OF MODELS-3 CMAQ

    EPA Science Inventory

    This performance evaluation compares a full annual simulation (2001) of CMAQ (Version4.4) covering the contiguous United States against monitoring data from four nationwide networks. This effort, which represents one of the most spatially and temporally comprehensive performance...

  14. Modeling and dynamic performance evaluation of target capture in robotic systems

    SciTech Connect

    Koevecses, J.; Cleghorn, W.L.; Fenton, R.G.

    2000-04-01

    In this paper, a dynamic system consisting of a robot manipulator and a target is analyzed. The target is considered in a general way as a dynamic subsystem having finite mass and moments of inertia (e.g., a rigid body or a second robot). The situation investigated is when the robot establishes interaction with the target in such a way that it intercepts and captures a reference element of the target. The analysis of target capture is divided into three phases in terms of time: the precapture, free motion (finite motion); the transition from free to constrained motion in the vicinity of interception and capture (impulsive motion); and the postcapture, constrained motion (finite motion). The greatest attention is paid to the analysis of the phase of transition, the impulsive motion, and dynamics of the system. Based on the use of impulsive constraints and the Jourdainian formulation of analytical dynamics, a novel approach is proposed for the dynamic modeling of target capture by a robot manipulator. The proposed approach is suitable to handle both finite and impulsive motions in a common analytical framework. Based on the dynamic model developed and using a geometric representation of the system's dynamics, a detailed analysis and a performance evaluation framework are presented for the phase of transition. Both rigid and structurally flexible models of robots are considered. For the performance evaluation analyses, two main concepts are proposed and corresponding performance measures are derived. These tools may be used in the analysis, design, and control of time-varying robotic systems. The dynamic system of a three-link robot arm capturing a rigid body is used to illustrate the material presented.

  15. Performance and evaluation of a coupled prognostic model TAPM over a mountainous complex terrain industrial area

    NASA Astrophysics Data System (ADS)

    Matthaios, Vasileios N.; Triantafyllou, Athanasios G.; Albanis, Triantafyllos A.; Sakkas, Vasileios; Garas, Stelios

    2017-04-01

    Atmospheric modeling is considered an important tool with several applications such as prediction of air pollution levels, air quality management, and environmental impact assessment studies. Therefore, evaluation studies must be continuously made, in order to improve the accuracy and the approaches of the air quality models. In the present work, an attempt is made to examine the air pollution model (TAPM) efficiency in simulating the surface meteorology, as well as the SO2 concentrations in a mountainous complex terrain industrial area. Three configurations under different circumstances, firstly with default datasets, secondly with data assimilation, and thirdly with updated land use, ran in order to investigate the surface meteorology for a 3-year period (2009-2011) and one configuration applied to predict SO2 concentration levels for the year of 2011.The modeled hourly averaged meteorological and SO2 concentration values were statistically compared with those from five monitoring stations across the domain to evaluate the model's performance. Statistical measures showed that the surface temperature and relative humidity are predicted well in all three simulations, with index of agreement (IOA) higher than 0.94 and 0.70 correspondingly, in all monitoring sites, while an overprediction of extreme low temperature values is noted, with mountain altitudes to have an important role. However, the results also showed that the model's performance is related to the configuration regarding the wind. TAPM default dataset predicted better the wind variables in the center of the simulation than in the boundaries, while improvement in the boundary horizontal winds implied the performance of TAPM with updated land use. TAPM assimilation predicted the wind variables fairly good in the whole domain with IOA higher than 0.83 for the wind speed and higher than 0.85 for the horizontal wind components. Finally, the SO2 concentrations were assessed by the model with IOA varied from 0

  16. Measuring Information Security Performance with 10 by 10 Model for Holistic State Evaluation

    PubMed Central

    2016-01-01

    Organizations should measure their information security performance if they wish to take the right decisions and develop it in line with their security needs. Since the measurement of information security is generally underdeveloped in practice and many organizations find the existing recommendations too complex, the paper presents a solution in the form of a 10 by 10 information security performance measurement model. The model—ISP 10×10M is composed of ten critical success factors, 100 key performance indicators and 6 performance levels. Its content was devised on the basis of findings presented in the current research studies and standards, while its structure results from an empirical research conducted among information security professionals from Slovenia. Results of the study show that a high level of information security performance is mostly dependent on measures aimed at managing information risks, employees and information sources, while formal and environmental factors have a lesser impact. Experts believe that information security should evolve systematically, where it’s recommended that beginning steps include technical, logical and physical security controls, while advanced activities should relate predominantly strategic management activities. By applying the proposed model, organizations are able to determine the actual level of information security performance based on the weighted indexing technique. In this manner they identify the measures they ought to develop in order to improve the current situation. The ISP 10×10M is a useful tool for conducting internal system evaluations and decision-making. It may also be applied to a larger sample of organizations in order to determine the general state-of-play for research purposes. PMID:27655001

  17. Evaluation of blade-strike models for estimating the biological performance of large Kaplan hydro turbines

    SciTech Connect

    Deng, Z.; Carlson, T. J.; Ploskey, G. R.; Richmond, M. C.

    2005-11-01

    Bio-indexing of hydro turbines has been identified as an important means to optimize passage conditions for fish by identifying operations for existing and new design turbines that minimize the probability of injury. Cost-effective implementation of bio-indexing requires the use of tools such as numerical and physical turbine models to generate hypotheses for turbine operations that can be tested at prototype scales using live fish. Blade strike has been proposed as an index variable for the biological performance of turbines. Report reviews an evaluation of the use of numerical blade-strike models as a means with which to predict the probability of blade strike and injury of juvenile salmon smolt passing through large Kaplan turbines on the mainstem Columbia River.

  18. Computational fluid dynamics model of WTP clearwell: Evaluation of critical parameters influencing model performance

    SciTech Connect

    Ducoste, J.; Brauer, R.

    1999-07-01

    Analysis of a computational fluid dynamics (CFD) model for a water treatment plant clearwell was done. Model parameters were analyzed to determine their influence on the effluent-residence time distribution (RTD) function. The study revealed that several model parameters could have significant impact on the shape of the RTD function and consequently raise the level of uncertainty on accurate predictions of clearwell hydraulics. The study also revealed that although the modeler could select a distribution of values for some of the model parameters, most of these values can be ruled out by requiring the difference between the calculated and theoretical hydraulic retention time to within 5% of the theoretical value.

  19. Apprentice Performance Evaluation.

    ERIC Educational Resources Information Center

    Gast, Clyde W.

    The Granite City (Illinois) Steel apprentices are under a performance evaluation from entry to graduation. Federally approved, the program is guided by joint apprenticeship committees whose monthly meetings include performance evaluation from three information sources: journeymen, supervisors, and instructors. Journeymen's evaluations are made…

  20. Formative Evaluation in the Performance Context.

    ERIC Educational Resources Information Center

    Dick, Walter; King, Debby

    1994-01-01

    Reviews the traditional formative evaluation model used by instructional designers; summarizes Kirkpatrick's model of evaluation; proposes the integration of part of Kirkpatrick's model with traditional formative evaluation; and discusses performance-context formative evaluation. (three references) (LRW)

  1. Performance evaluation of regional climate model to simulate sub-seasonal variability of Indian Summer Monsoon

    NASA Astrophysics Data System (ADS)

    Umakanth, U.; Kesarkar, Amit P.

    2017-07-01

    The study aims to evaluate the regional climate model (RegCM) over South Asian (SA) CORDEX domain to represent seasonal and sub-seasonal variability of Indian Summer Monsoon (ISM). The model's ability is evaluated by conducting two sets of experiments using one-tier approach of coupling the RegCM with a simple mixed-layer slab ocean model (SOM) and the two-tier approach of prescribing sea surface temperature (SST) to RegCM. Two model experiments are initialized at 1st January 2000 for a period of 13 year continuous simulation at a spatial resolution of 50 km. It is found that, one-tier approach realistically represents the spatial distribution of precipitation with significant improvement noticed over central India (CI) and head Bay of Bengal (BoB) regions. In addition, it also fairly reproduced the observed mean meridional circulation response to the diabatic heating produced during ISM. Most importantly, in one-tier approach the model could able to represent the observed SST and precipitation (P) relationship with significant improvement in correlation and model response time. An important result is the representation of northwest-southeast tilt of precipitation anomalies during active/break phase of monsoon. Additionally, the lagged response of vertical profiles of specific humidity, omega, vorticity and divergence over CI with respect to peak rainfall anomaly (active phase) are relatively better represented in one-tier approach. In brief, coupling improves the performance of RegCM in simulating the space-time characteristics of monsoon ISO mode.

  2. Evaluation of GLAS Demonstration Model Loop Heat Pipe Thermal Vacuum Performance with Various Fluid Charges

    NASA Technical Reports Server (NTRS)

    Baker, Charles; Butler, Dan; Ku, Jentung; Grob, Eric; Swanson, Ted; Nikitkin, Michael; Paquin, Krista C. (Technical Monitor)

    2001-01-01

    Two loop heat pipes (LHPs) are to be used for tight thermal control of the Geoscience Laser Altimeter System (GLAS) instrument, planned for flight in late 2001. The LHPs are charged with Propylene as a working fluid. One LHP will be used to transport 110 W from a laser a radiator, the other will transport 190 W from electronic boxes to a separate radiator. The application includes a large amount of thermal mass in each LHP system and low initial startup powers. This along with some non-ideal flight design compromises, such as a less than ideal charge level for this design concept with a symmetrical secondary wick, lead to inadequate performance of the flight LHPs during the flight thermal vacuum test in October of 2000. This presentation focuses on identifying; the sources of the flight test difficulties by modifying the charge and test setup of the successfully tested Development Model Loop Heat Pipe (DM LHP). While very similar to the flight design, the DM L14P did have several significant difference in design and method of testing. These differences were evaluated for affect on performance by conforming the DM LHP to look more like the flight units. The major difference that was evaluated was the relative fill level of the working fluid within the concentrically design LHP compensation chamber. Other differences were also assessed through performance testing including starter heater size and "hot biasing" of major interior components. Performance was assessed with respect to startup, low power operation, conductance, and control heater power. The results of the testing showed that performance improves as initial charge increases, and when the starter heater is made smaller. The "hot biasing" of the major components did not appear to have a detrimental effect. As a result of test results of the DM LHP, modifications are being made to the flight units to increase the fluid charge and increase the watt-density of the starter heater.

  3. Evaluation of GLAS Demonstration Model Loop Heat Pipe Thermal Vacuum Performance with Various Fluid Charges

    NASA Technical Reports Server (NTRS)

    Baker, Charles; Butler, Dan; Ku, Jentung; Grob, Eric; Swanson, Ted; Nikitkin, Michael; Paquin, Krista C. (Technical Monitor)

    2001-01-01

    Two loop heat pipes (LHPs) are to be used for tight thermal control of the Geoscience Laser Altimeter System (GLAS) instrument, planned for flight in late 2001. The LHPs are charged with Propylene as a working fluid. One LHP will be used to transport 110 W from a laser a radiator, the other will transport 190 W from electronic boxes to a separate radiator. The application includes a large amount of thermal mass in each LHP system and low initial startup powers. This along with some non-ideal flight design compromises, such as a less than ideal charge level for this design concept with a symmetrical secondary wick, lead to inadequate performance of the flight LHPs during the flight thermal vacuum test in October of 2000. This presentation focuses on identifying; the sources of the flight test difficulties by modifying the charge and test setup of the successfully tested Development Model Loop Heat Pipe (DM LHP). While very similar to the flight design, the DM L14P did have several significant difference in design and method of testing. These differences were evaluated for affect on performance by conforming the DM LHP to look more like the flight units. The major difference that was evaluated was the relative fill level of the working fluid within the concentrically design LHP compensation chamber. Other differences were also assessed through performance testing including starter heater size and "hot biasing" of major interior components. Performance was assessed with respect to startup, low power operation, conductance, and control heater power. The results of the testing showed that performance improves as initial charge increases, and when the starter heater is made smaller. The "hot biasing" of the major components did not appear to have a detrimental effect. As a result of test results of the DM LHP, modifications are being made to the flight units to increase the fluid charge and increase the watt-density of the starter heater.

  4. EO/IR sensor model for evaluating multispectral imaging system performance

    NASA Astrophysics Data System (ADS)

    Richwine, Robert; Sood, Ashok K.; Balcerak, Raymond S.; Freyvogel, Ken

    2007-04-01

    This paper discusses the capabilities of a EO/IR sensor model developed to provide a robust means for comparative assessments of infrared FPA's and sensors operating in the infrared spectral bands that coincide with the atmospheric windows - SW1 (1.0-1.8μm), sMW (2-2.5μm), MW (3-5μm), and LW (8-12μm). The applications of interest include thermal imaging, threat warning, missile interception, UAV surveillance, forest fire and agricultural crop health assessments, and mine detection. As a true imaging model it also functions as an assessment tool for single-band and multi-color imagery. The detector model characterizes InGaAs, InSb, HgCdTe, QWIP and microbolometer sensors for spectral response, dark currents and noise. The model places the specified FPA into an optical system, evaluates system performance (NEI, NETD, MRTD, and SNR) and creates two-point corrected imagery complete with 3-D noise image effects. Analyses are possible for both passive and active laser illuminated scenes for simulated state-of-the-art IR FPA's and Avalanche Photodiode Detector (APD) arrays. Simulated multispectral image comparisons expose various scene components of interest which are illustrated using the imaging model. This model has been exercised here as a predictive tool for the performance of state-of-the-art detector arrays in optical systems in the five spectral bands (atmospheric windows) from the SW to the LW and as a potential testbed for prototype sensors. Results of the analysis will be presented for various targets for each of the focal plane technologies for a variety of missions.

  5. Evaluating and Improving the Performance of Common Land Model Using FLUXNET Data

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Dai, Y. J.; Dickinson, R. E.

    2015-12-01

    Common Land Model(CoLM), combined the best features of LSM, BATS, and IAP94, has been widely applied and shown its good quality. However, land surface processes are crucial for weather and climate model initialization, hence it's necessary to constrain land surface model performances using observational data. In our preliminary work, eddy covariance measurements from 20 FLUXNET sites with over 100 site-years were used to evaluate CoLM while simulating energy balance fluxes in different climate conditions and vegetation categories. And the results show CoLM simulates well for all four energy fluxes, with sensible heat flux(H) better than latent heat flux(LE), net radiation (Rnet) the best. In terms of different vegetation categories, CoLM performs the best on evergreen needle-leaf forest among the 8 selected land cover types, and shows significant priority at evergreen broadleaf forest. Although a good agreement of simulation and observation is found on seasonal cycles at the 20 sample sites, it produces extreme bias mostly at summer noon, but not shows consistent bias among different seasons. This underestimate was associated with the weakness in simulating of soil water in dry seasons and incomplete description of photosynthesis as well, that's why we will first focus on implementing mesophyll diffusion in CoLM to improve the physical process of photosynthesis.

  6. The performance evaluation of WinOSPM model for urban street canyons of Nantes in France.

    PubMed

    Gokhale, Sharad B; Rebours, Arnaud; Pavageau, Michel

    2005-01-01

    was done to evaluate the models performance using index of agreement and correlation coefficient. The index of agreement (d) and correlation coefficient (r) for all the streets show that estimated concentration levels are in good agreement with that of measurements. From the index of agreements, it can be inferred that model has very less potential for errors. The model's sensitivity to building-exceptions was also tested for the rue de Strasbourg. Results did not reflect this feature very well. It is perceived that the influence of this feature might have been suppressed in averaging the annual hourly values. This influence is apparently seen in hourly average time series variations. Finally, WinOSPM model was found a simple but very useful model. It could very well represent the detailed flow and dispersion conditions in urban streets.

  7. Evaluating NARCCAP model performance for frequencies of severe-storm environments

    NASA Astrophysics Data System (ADS)

    Gilleland, Eric; Bukovsky, Melissa; Williams, Christopher L.; McGinnis, Seth; Ammann, Caspar M.; Brown, Barbara G.; Mearns, Linda O.

    2016-11-01

    An important topic for climate change investigation is the behavior of severe weather under future scenarios. Given the fine-scale nature of the phenomena, such changes can only be analyzed indirectly, for example, through large-scale indicators of environments conducive to severe weather. Climate models can account for changing physics over time, but if they cannot capture the relevant distributional properties of the current climate, then their use for inferring future regimes is limited. In this study, high-resolution climate models from the North American Regional Climate Change Assessment Program (NARCCAP) are evaluated for the present climate state using cutting-edge spatial verification techniques recently popularized in the meteorology literature. While climate models are not intended to predict variables on a day-by-day basis, like weather models, they should be expected to mimic distributional properties of these processes, which is how they are increasingly used and therefore this study assesses the degree to which the models are actually suitable for this purpose. Of particular value for social applications would be to better simulate extremes, rather than inferring means of variables, which may only change by small increments thereby making it difficult to interpret in terms of the impact on society. In this study, it is found that the relatively high-resolution NARCCAP climate model runs capture areas, spatial patterns, and placement of the most common severe-storm environments reasonably well, but all of them underpredict the spatial extent of these high-frequency zones. Some of the models generally perform better than others, but some models capture spatial patterns of the highest frequency severe-storm environment areas better than they do more moderate frequency regions.

  8. Transport modeling and multivariate adaptive regression splines for evaluating performance of ASR systems in freshwater aquifers

    NASA Astrophysics Data System (ADS)

    Forghani, Ali; Peralta, Richard C.

    2017-10-01

    The study presents a procedure using solute transport and statistical models to evaluate the performance of aquifer storage and recovery (ASR) systems designed to earn additional water rights in freshwater aquifers. The recovery effectiveness (REN) index quantifies the performance of these ASR systems. REN is the proportion of the injected water that the same ASR well can recapture during subsequent extraction periods. To estimate REN for individual ASR wells, the presented procedure uses finely discretized groundwater flow and contaminant transport modeling. Then, the procedure uses multivariate adaptive regression splines (MARS) analysis to identify the significant variables affecting REN, and to identify the most recovery-effective wells. Achieving REN values close to 100% is the desire of the studied 14-well ASR system operator. This recovery is feasible for most of the ASR wells by extracting three times the injectate volume during the same year as injection. Most of the wells would achieve RENs below 75% if extracting merely the same volume as they injected. In other words, recovering almost all the same water molecules that are injected requires having a pre-existing water right to extract groundwater annually. MARS shows that REN most significantly correlates with groundwater flow velocity, or hydraulic conductivity and hydraulic gradient. MARS results also demonstrate that maximizing REN requires utilizing the wells located in areas with background Darcian groundwater velocities less than 0.03 m/d. The study also highlights the superiority of MARS over regular multiple linear regressions to identify the wells that can provide the maximum REN. This is the first reported application of MARS for evaluating performance of an ASR system in fresh water aquifers.

  9. Performance Metrics for Climate Model Evaluation: Application to CMIP5 Precipitation Simulations

    NASA Astrophysics Data System (ADS)

    Mehran, A.; AghaKouchak, A.; Phillips, T. J.

    2013-12-01

    Validation of gridded climate model simulations is fundamental to future improvements in model developments. Among the metrics, the contingency table, which includes a number of categorical indices, is extensively used in evaluation studies. While the categorical indices offer invaluable information, they do not provide any insight into the volume of the variable detected correctly/incorrectly. In this study, the contingency table categorical metrics are extended to volumetric indices for evaluation of gridded data. The suggested indices include (a) Volumetric Hit Index (VHI): volume of correctly detected simulations relative to the volume of the correctly detected simulations and missed observations; (b) Volumetric False Alarm Ratio (VFAR): volume of false simulations relative to the sum of simulations; (c) Volumetric Miss Index (VMI): volume of missed observations relative to the sum of missed observations and correctly detected simulations; and (d) the Volumetric Critical Success Index (VCSI). The latter provides an overall measure of volumetric performance including volumetric hits, false alarms and misses. Numerous studies have emphasized that climate simulations are subject to various biases and uncertainties. The objective of this study is to cross-validate 34 Coupled Model Inter-comparison Project Phase 5 (CMIP5) historical simulations of precipitation against the Global Precipitation Climatology Project (GPCP) data using the proposed performance metrics, quantifying model pattern discrepancies and biases for both entire data distributions and their upper tails. The results of the Volumetric Hit Index (VHI) analysis of the total monthly precipitation amounts show that most CMIP5 simulations are in good agreement with GPCP patterns in many areas, but their replication of observed precipitation over arid regions and certain sub-continental regions (e.g., northern Eurasia, eastern Russia, central Australia) is problematical. Overall, the VHI of the multi-model

  10. Evaluation of odometry algorithm performances using a railway vehicle dynamic model

    NASA Astrophysics Data System (ADS)

    Allotta, B.; Pugi, L.; Ridolfi, A.; Malvezzi, M.; Vettori, G.; Rindi, A.

    2012-05-01

    In modern railway Automatic Train Protection and Automatic Train Control systems, odometry is a safety relevant on-board subsystem which estimates the instantaneous speed and the travelled distance of the train; a high reliability of the odometry estimate is fundamental, since an error on the train position may lead to a potentially dangerous overestimation of the distance available for braking. To improve the odometry estimate accuracy, data fusion of different inputs coming from a redundant sensor layout may be used. Simplified two-dimensional models of railway vehicles have been usually used for Hardware in the Loop test rig testing of conventional odometry algorithms and of on-board safety relevant subsystems (like the Wheel Slide Protection braking system) in which the train speed is estimated from the measures of the wheel angular speed. Two-dimensional models are not suitable to develop solutions like the inertial type localisation algorithms (using 3D accelerometers and 3D gyroscopes) and the introduction of Global Positioning System (or similar) or the magnetometer. In order to test these algorithms correctly and increase odometry performances, a three-dimensional multibody model of a railway vehicle has been developed, using Matlab-Simulink™, including an efficient contact model which can simulate degraded adhesion conditions (the development and prototyping of odometry algorithms involve the simulation of realistic environmental conditions). In this paper, the authors show how a 3D railway vehicle model, able to simulate the complex interactions arising between different on-board subsystems, can be useful to evaluate the odometry algorithm and safety relevant to on-board subsystem performances.

  11. Resampling and extreme-value statistics in air-quality-model performance evaluation

    SciTech Connect

    Rao, S.T.; Sistla, G.; Pagnotti, V.; Petersen, W.B.; Irwin, J.S.

    1985-01-01

    Specific data-analysis techniques that will reveal the performance of air-quality models in simulating the measured concentrations' cumulative distribution are discussed. The paper presents two types of analysis to compare model predictions with the measurements. In one analysis, extreme-value statistics and the fitting of tail exponential distributions to both measured and predicted values are used in various ways to see if the measured and predicted values fit such distributions and to what degree the higher values of the cumulative frequency distributions coincide. In the second analysis, a resampling (bootstrap technique is used to develop non-parametric confidence intervals for the entire cumulative distribution of the measured concentrations, and to derive empirical distributions for central tendency statistics and for differences between measured and predicted mean and median values. The analysis is focused so as to show (1) why the resampling is necessary and the degree to which mistaken judgments can be made with and without the technique, and (2) comparisons between the discriminating capabilities of 'tail fit' type model evaluation and one using the resampling technique. It is shown that both the bootstrap and extreme value statistics are needed to quantify the uncertainty associated with the model predictions.

  12. Performance evaluation and model analysis of BTEX contaminated air in corn-cob biofilter system.

    PubMed

    Rahul; Mathur, Anil Kumar; Balomajumder, Chandrajit

    2013-04-01

    Biofiltration of BTEX with corn-cob packing material have been performed for a period of 68 days in five distinct phases. The overall performance of a biofilter has been evaluated in terms of its elimination capacity by using 3-D mesh techniques. Maximum removal efficiency was found more than 99.85% of all four compounds at an EBRT of 3.06 min in phase I for an inlet BTEX concentration of 0.0970, 0.0978, 0.0971 and 0.0968 g m(-3), respectively. Nearly 100% removal achieved at average BTEX loadings of 20.257 g m(-3) h(-1) to biofilter. A maximum elimination capacity (EC) of 20.239 g m(-3) h(-1) of the biofilter was obtained at inlet BTEX load of 20.391 g m(-3) h(-1). Moreover, using convection-diffusion reaction (CDR) model for biofilter depth shows good agreement with the experimental values for benzene, toluene and ethyl benzene, but for o-xylene the model results deviated from the experimental. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Evaluation of Contamination Inspection and Analysis Methods through Modeling System Performance

    NASA Technical Reports Server (NTRS)

    Seasly, Elaine; Dever, Jason; Stuban, Steven M. F.

    2016-01-01

    Contamination is usually identified as a risk on the risk register for sensitive space systems hardware. Despite detailed, time-consuming, and costly contamination control efforts during assembly, integration, and test of space systems, contaminants are still found during visual inspections of hardware. Improved methods are needed to gather information during systems integration to catch potential contamination issues earlier and manage contamination risks better. This research explores evaluation of contamination inspection and analysis methods to determine optical system sensitivity to minimum detectable molecular contamination levels based on IEST-STD-CC1246E non-volatile residue (NVR) cleanliness levels. Potential future degradation of the system is modeled given chosen modules representative of optical elements in an optical system, minimum detectable molecular contamination levels for a chosen inspection and analysis method, and determining the effect of contamination on the system. By modeling system performance based on when molecular contamination is detected during systems integration and at what cleanliness level, the decision maker can perform trades amongst different inspection and analysis methods and determine if a planned method is adequate to meet system requirements and manage contamination risk.

  14. Field significance of performance measures in the context of regional climate model evaluation. Part 2: precipitation

    NASA Astrophysics Data System (ADS)

    Ivanov, Martin; Warrach-Sagi, Kirsten; Wulfmeyer, Volker

    2017-02-01

    A new approach for rigorous spatial analysis of the downscaling performance of regional climate model (RCM) simulations is introduced. It is based on a multiple comparison of the local tests at the grid cells and is also known as `field' or `global' significance. The block length for the local resampling tests is precisely determined to adequately account for the time series structure. New performance measures for estimating the added value of downscaled data relative to the large-scale forcing fields are developed. The methodology is exemplarily applied to a standard EURO-CORDEX hindcast simulation with the Weather Research and Forecasting (WRF) model coupled with the land surface model NOAH at 0.11 ∘ grid resolution. Daily precipitation climatology for the 1990-2009 period is analysed for Germany for winter and summer in comparison with high-resolution gridded observations from the German Weather Service. The field significance test controls the proportion of falsely rejected local tests in a meaningful way and is robust to spatial dependence. Hence, the spatial patterns of the statistically significant local tests are also meaningful. We interpret them from a process-oriented perspective. While the downscaled precipitation distributions are statistically indistinguishable from the observed ones in most regions in summer, the biases of some distribution characteristics are significant over large areas in winter. WRF-NOAH generates appropriate stationary fine-scale climate features in the daily precipitation field over regions of complex topography in both seasons and appropriate transient fine-scale features almost everywhere in summer. As the added value of global climate model (GCM)-driven simulations cannot be smaller than this perfect-boundary estimate, this work demonstrates in a rigorous manner the clear additional value of dynamical downscaling over global climate simulations. The evaluation methodology has a broad spectrum of applicability as it is

  15. On the current state of the Hydrologic Evaluation of Landfill Performance (HELP) model.

    PubMed

    Berger, Klaus U

    2015-04-01

    The Hydrologic Evaluation of Landfill Performance (HELP) model is the most widely applied model to calculate the water balance of cover and bottom liner systems for landfills. The paper summarizes the 30 year history of the model from HELP version 1 to HELP 3.95 D and includes references to the three current and simultaneously available versions (HELP 3.07, Visual HELP 2.2, and HELP 3.95 D). A sufficient validation is an essential precondition for the use of any model in planning. The paper summarizes validation approaches for HELP 3 focused on cover systems in the literature. Furthermore, measurement results are compared to simulation results of HELP 3.95 D for (1) a test field with a compacted clay liner in the final cover of the landfill Hamburg-Georgswerder from 1988 to 1995 and (2) a test field with a 2.3m thick so-called water balance layer on the landfill Deetz near Berlin from 2004 to 2011. On the Georgswerder site actual evapotranspiration was well reproduced by HELP on the yearly average as well as in the seasonal course if precipitation data with 10% systematic measurement errors were used. However, the increase of liner leakage due to the deterioration of the clayey soil liner was not considered by the model. On the landfill Deetz HELP overestimated largely the percolation through the water balance layer resulting from an extremely wet summer due to an underestimation of the water storage in the layer and presumably also due to an underestimation of the actual evapotranspiration. Finally based on validation results and requests from the practice, plans for improving the model to a future version HELP 4 D are described.

  16. Model performance evaluation (validation and calibration) in model-based studies of therapeutic interventions for cardiovascular diseases : a review and suggested reporting framework.

    PubMed

    Haji Ali Afzali, Hossein; Gray, Jodi; Karnon, Jonathan

    2013-04-01

    Decision analytic models play an increasingly important role in the economic evaluation of health technologies. Given uncertainties around the assumptions used to develop such models, several guidelines have been published to identify and assess 'best practice' in the model development process, including general modelling approach (e.g., time horizon), model structure, input data and model performance evaluation. This paper focuses on model performance evaluation. In the absence of a sufficient level of detail around model performance evaluation, concerns regarding the accuracy of model outputs, and hence the credibility of such models, are frequently raised. Following presentation of its components, a review of the application and reporting of model performance evaluation is presented. Taking cardiovascular disease as an illustrative example, the review investigates the use of face validity, internal validity, external validity, and cross model validity. As a part of the performance evaluation process, model calibration is also discussed and its use in applied studies investigated. The review found that the application and reporting of model performance evaluation across 81 studies of treatment for cardiovascular disease was variable. Cross-model validation was reported in 55 % of the reviewed studies, though the level of detail provided varied considerably. We found that very few studies documented other types of validity, and only 6 % of the reviewed articles reported a calibration process. Considering the above findings, we propose a comprehensive model performance evaluation framework (checklist), informed by a review of best-practice guidelines. This framework provides a basis for more accurate and consistent documentation of model performance evaluation. This will improve the peer review process and the comparability of modelling studies. Recognising the fundamental role of decision analytic models in informing public funding decisions, the proposed

  17. Modelling and evaluation of nitrogen removal performance in subsurface flow and free water surface constructed wetlands.

    PubMed

    Tunçsiper, B; Ayaz, S C; Akça, L

    2006-01-01

    With the aim of protecting drinking water sources in rural regions, pilot-scale subsurface water flow (SSF) and free water surface flow (FWS) constructed wetland systems were evaluated for removal efficiencies of nitrogenous pollutants in tertiary stage treated wastewaters (effluent from the Pasaköy biological nutrient removal plant). Five different hydraulic application rates and emergent (Canna, Cyperus, Typhia sp., Phragmites sp., Juncus, Poaceae, Paspalum and Iris) and floating (Pistia, Salvina and Lemna) plant species were assayed. The average annual NH4-N, NO3-N and organic-N treatment efficiencies were 81, 40 and 74% in SSFs and 76, 59 and 75% in FWSs, respectively. Two types of the models (first-order plug flow and multiple regression) were tried to estimate the system performances. Nitrification, denitrification and ammonification rate constants (k20) values in SSF and FWS systems were 0.898 d-1 and 0.541 d(-1), 0.486 d(-1) and 0.502 d(-1), 0.986 d(-1) and 0.908, respectively. Results show that the first-order plug flow model clearly estimates slightly higher or lower values than observed when compared with the other model.

  18. Regionalized PM2.5 Community Multiscale Air Quality model performance evaluation across a continuous spatiotemporal domain

    NASA Astrophysics Data System (ADS)

    Reyes, Jeanette M.; Xu, Yadong; Vizuete, William; Serre, Marc L.

    2017-01-01

    The regulatory Community Multiscale Air Quality (CMAQ) model is a means to understanding the sources, concentrations and regulatory attainment of air pollutants within a model's domain. Substantial resources are allocated to the evaluation of model performance. The Regionalized Air quality Model Performance (RAMP) method introduced here explores novel ways of visualizing and evaluating CMAQ model performance and errors for daily Particulate Matter ≤ 2.5 μm (PM2.5) concentrations across the continental United States. The RAMP method performs a non-homogenous, non-linear, non-homoscedastic model performance evaluation at each CMAQ grid. This work demonstrates that CMAQ model performance, for a well-documented 2001 regulatory episode, is non-homogeneous across space/time. The RAMP correction of systematic errors outperforms other model evaluation methods as demonstrated by a 22.1% reduction in Mean Square Error compared to a constant domain wide correction. The RAMP method is able to accurately reproduce simulated performance with a correlation of r = 76.1%. Most of the error coming from CMAQ is random error with only a minority of error being systematic. Areas of high systematic error are collocated with areas of high random error, implying both error types originate from similar sources. Therefore, addressing underlying causes of systematic error will have the added benefit of also addressing underlying causes of random error.

  19. Regionalized PM2.5 Community Multiscale Air Quality model performance evaluation across a continuous spatiotemporal domain.

    PubMed

    Reyes, Jeanette M; Xu, Yadong; Vizuete, William; Serre, Marc L

    2017-01-01

    The regulatory Community Multiscale Air Quality (CMAQ) model is a means to understanding the sources, concentrations and regulatory attainment of air pollutants within a model's domain. Substantial resources are allocated to the evaluation of model performance. The Regionalized Air quality Model Performance (RAMP) method introduced here explores novel ways of visualizing and evaluating CMAQ model performance and errors for daily Particulate Matter ≤ 2.5 micrometers (PM2.5) concentrations across the continental United States. The RAMP method performs a non-homogenous, non-linear, non-homoscedastic model performance evaluation at each CMAQ grid. This work demonstrates that CMAQ model performance, for a well-documented 2001 regulatory episode, is non-homogeneous across space/time. The RAMP correction of systematic errors outperforms other model evaluation methods as demonstrated by a 22.1% reduction in Mean Square Error compared to a constant domain wide correction. The RAMP method is able to accurately reproduce simulated performance with a correlation of r = 76.1%. Most of the error coming from CMAQ is random error with only a minority of error being systematic. Areas of high systematic error are collocated with areas of high random error, implying both error types originate from similar sources. Therefore, addressing underlying causes of systematic error will have the added benefit of also addressing underlying causes of random error.

  20. Performance evaluation of Al-Zahra academic medical center based on Iran balanced scorecard model

    PubMed Central

    Raeisi, Ahmad Reza; Yarmohammadian, Mohammad Hossein; Bakhsh, Roghayeh Mohammadi; Gangi, Hamid

    2012-01-01

    Background: Growth and development in any country's national health system, without an efficient evaluation system, lacks the basic concepts and tools necessary for fulfilling the system's goals. The balanced scorecard (BSC) is a technique widely used to measure the performance of an organization. The basic core of the BSC is guided by the organization's vision and strategies, which are the bases for the formation of four perspectives of BSC. The goal of this research is the performance evaluation of Al-Zahra Academic Medical Center in Isfahan University of Medical Sciences, based on Iran BSC model. Materials and Methods: This is a combination (quantitative–qualitative) research which was done at Al-Zahra Academic Medical Center in Isfahan University of Medical Sciences in 2011. The research populations were hospital managers at different levels. Sampling method was purposive sampling in which the key informed personnel participated in determining the performance indicators of hospital as the BSC team members in focused discussion groups. After determining the conceptual elements in focused discussion groups, the performance objectives (targets) and indicators of hospital were determined and sorted in perspectives by the group discussion participants. Following that, the performance indicators were calculated by the experts according to the predetermined objectives; then, the score of each indicator and the mean score of each perspective were calculated. Results: Research findings included development of the organizational mission, vision, values, objectives, and strategies. The strategies agreed upon by the participants in the focus discussion group included five strategies, which were customer satisfaction, continuous quality improvement, development of human resources, supporting innovation, expansion of services and improving the productivity. Research participants also agreed upon four perspectives for the Al-Zahra hospital BSC. In the patients and community

  1. Performance evaluation of groundwater model hydrostratigraphy from airborne electromagnetic data and lithological borehole logs

    NASA Astrophysics Data System (ADS)

    Marker, P. A.; Foged, N.; He, X.; Christiansen, A. V.; Refsgaard, J. C.; Auken, E.; Bauer-Gottwein, P.

    2015-09-01

    Large-scale hydrological models are important decision support tools in water resources management. The largest source of uncertainty in such models is the hydrostratigraphic model. Geometry and configuration of hydrogeological units are often poorly determined from hydrogeological data alone. Due to sparse sampling in space, lithological borehole logs may overlook structures that are important for groundwater flow at larger scales. Good spatial coverage along with high spatial resolution makes airborne electromagnetic (AEM) data valuable for the structural input to large-scale groundwater models. We present a novel method to automatically integrate large AEM data sets and lithological information into large-scale hydrological models. Clay-fraction maps are produced by translating geophysical resistivity into clay-fraction values using lithological borehole information. Voxel models of electrical resistivity and clay fraction are classified into hydrostratigraphic zones using k-means clustering. Hydraulic conductivity values of the zones are estimated by hydrological calibration using hydraulic head and stream discharge observations. The method is applied to a Danish case study. Benchmarking hydrological performance by comparison of performance statistics from comparable hydrological models, the cluster model performed competitively. Calibrations of 11 hydrostratigraphic cluster models with 1-11 hydraulic conductivity zones showed improved hydrological performance with an increasing number of clusters. Beyond the 5-cluster model hydrological performance did not improve. Due to reproducibility and possibility of method standardization and automation, we believe that hydrostratigraphic model generation with the proposed method has important prospects for groundwater models used in water resources management.

  2. Application of Wavelet Filters in an Evaluation of Photochemical Model Performance

    EPA Science Inventory

    Air quality model evaluation can be enhanced with time-scale specific comparisons of outputs and observations. For example, high-frequency (hours to one day) time scale information in observed ozone is not well captured by deterministic models and its incorporation into model pe...

  3. Application of Wavelet Filters in an Evaluation of Photochemical Model Performance

    EPA Science Inventory

    Air quality model evaluation can be enhanced with time-scale specific comparisons of outputs and observations. For example, high-frequency (hours to one day) time scale information in observed ozone is not well captured by deterministic models and its incorporation into model pe...

  4. Modeling and performance evaluation of the DPS25 packet switching multiprocessor system

    NASA Astrophysics Data System (ADS)

    Mitropoulos, Spyridon

    1987-05-01

    A packet switching communication network is evaluated via queue network modeling theory. Direct access memory systems, busses linking the network processors, commutation and signal processors, and virtual reference circuits are considered. All models are developed with the help of the QNAP2 program and listings of the models are given. The method is illustrated with results from simulations at the various system levels.

  5. Urban climate model MUKLIMO_3 in prediction mode - evaluation of model performance based on the case study of Vienna

    NASA Astrophysics Data System (ADS)

    Hollosi, Brigitta; Zuvela-Aloise, Maja

    2017-04-01

    To reduce negative health impacts of extreme heat load in urban areas is the application of early warning systems that use weather forecast models to predict forthcoming heat events of utmost importance. In the state-of-the-art operational heat warning systems the meteorological information relies on the weather forecast from the regional numerical models and monitoring stations that do not include details of urban structure. In this study, the dynamical urban climate model MUKLIMO3 (horizontal resolution of 100 - 200 m) is initialized with the vertical profiles from the archived daily forecast data of the ZAMG from the hydrostatic ALARO numerical weather prediction model run at 0600 UTC to simulate the development of the urban heat island in Vienna on a daily basis. The aim is to evaluate the performance of the urban climate model, so far applied only for climatological studies, in a weather prediction mode using the summer period 2011-2015 as a test period. The focus of the investigation is on assessment of the urban heat load during the day-time. The model output has been evaluated against the monitoring data at the weather stations in the area of the city. The model results for daily maximum temperature show good agreement with the observations, especially at the urban and suburban stations where the mean bias is low. The results are highly dependent on the input data from the meso-scale model that leads to larger deviation from observations if the prediction is not representative for the given day. This study can be used to support urban planning strategies and to improve existing practices to alert decision-makers and the public to impending dangers of excessive heat.

  6. Inter-comparison and performance evaluation of chemistry transport models over Indian region

    NASA Astrophysics Data System (ADS)

    Govardhan, Gaurav R.; Nanjundiah, Ravi S.; Satheesh, S. K.; Moorthy, K. Krishna; Takemura, Toshihiko

    2016-01-01

    Aerosol loading over the South Asian region has the potential to affect the monsoon rainfall, Himalayan glaciers and regional air-quality, with implications for the billions in this region. While field campaigns and network observations provide primary data, they tend to be location/season specific. Numerical models are useful to regionalize such location-specific data. Studies have shown that numerical models underestimate the aerosol scenario over the Indian region, mainly due to shortcomings related to meteorology and the emission inventories used. In this context, we have evaluated the performance of two such chemistry-transport models: WRF-Chem and SPRINTARS over an India-centric domain. The models differ in many aspects including physical domain, horizontal resolution, meteorological forcing and so on etc. Despite these differences, both the models simulated similar spatial patterns of Black Carbon (BC) mass concentration, (with a spatial correlation of 0.9 with each other), and a reasonable estimates of its concentration, though both of them under-estimated vis-a-vis the observations. While the emissions are lower (higher) in SPRINTARS (WRF-Chem), overestimation of wind parameters in WRF-Chem caused the concentration to be similar in both models. Additionally, we quantified the underestimations of anthropogenic BC emissions in the inventories used these two models and three other widely used emission inventories. Our analysis indicates that all these emission inventories underestimate the emissions of BC over India by a factor that ranges from 1.5 to 2.9. We have also studied the model simulations of aerosol optical depth over the Indian region. The models differ significantly in simulations of AOD, with WRF-Chem having a better agreement with satellite observations of AOD as far as the spatial pattern is concerned. It is important to note that in addition to BC, dust can also contribute significantly to AOD. The models differ in simulations of the spatial

  7. Field significance of performance measures in the context of regional climate model evaluation. Part 1: temperature

    NASA Astrophysics Data System (ADS)

    Ivanov, Martin; Warrach-Sagi, Kirsten; Wulfmeyer, Volker

    2017-03-01

    A new approach for rigorous spatial analysis of the downscaling performance of regional climate model (RCM) simulations is introduced. It is based on a multiple comparison of the local tests at the grid cells and is also known as "field" or "global" significance. New performance measures for estimating the added value of downscaled data relative to the large-scale forcing fields are developed. The methodology is exemplarily applied to a standard EURO-CORDEX hindcast simulation with the Weather Research and Forecasting (WRF) model coupled with the land surface model NOAH at 0.11 ∘ grid resolution. Monthly temperature climatology for the 1990-2009 period is analysed for Germany for winter and summer in comparison with high-resolution gridded observations from the German Weather Service. The field significance test controls the proportion of falsely rejected local tests in a meaningful way and is robust to spatial dependence. Hence, the spatial patterns of the statistically significant local tests are also meaningful. We interpret them from a process-oriented perspective. In winter and in most regions in summer, the downscaled distributions are statistically indistinguishable from the observed ones. A systematic cold summer bias occurs in deep river valleys due to overestimated elevations, in coastal areas due probably to enhanced sea breeze circulation, and over large lakes due to the interpolation of water temperatures. Urban areas in concave topography forms have a warm summer bias due to the strong heat islands, not reflected in the observations. WRF-NOAH generates appropriate fine-scale features in the monthly temperature field over regions of complex topography, but over spatially homogeneous areas even small biases can lead to significant deteriorations relative to the driving reanalysis. As the added value of global climate model (GCM)-driven simulations cannot be smaller than this perfect-boundary estimate, this work demonstrates in a rigorous manner the

  8. Undergraduate Engineering Students' Beliefs, Coping Strategies, and Academic Performance: An Evaluation of Theoretical Models

    ERIC Educational Resources Information Center

    Hsieh, Pei-Hsuan; Sullivan, Jeremy R.; Sass, Daniel A.; Guerra, Norma S.

    2012-01-01

    Research has identified factors associated with academic success by evaluating relations among psychological and academic variables, although few studies have examined theoretical models to understand the complex links. This study used structural equation modeling to investigate whether the relation between test anxiety and final course grades was…

  9. Undergraduate Engineering Students' Beliefs, Coping Strategies, and Academic Performance: An Evaluation of Theoretical Models

    ERIC Educational Resources Information Center

    Hsieh, Pei-Hsuan; Sullivan, Jeremy R.; Sass, Daniel A.; Guerra, Norma S.

    2012-01-01

    Research has identified factors associated with academic success by evaluating relations among psychological and academic variables, although few studies have examined theoretical models to understand the complex links. This study used structural equation modeling to investigate whether the relation between test anxiety and final course grades was…

  10. Goal Setting and Performance Evaluation with Different Starting Positions: The Modeling Dilemma.

    ERIC Educational Resources Information Center

    Pray, Thomas F.; Gold, Steven

    1991-01-01

    Reviews 10 computerized business simulations used to teach business policy courses, discusses problems with measuring performance, and presents a statistically based approach to assessing performance that permits individual team goal setting as part of the computer model, and allows simulated firms to start with different financial and operating…

  11. Evaluating performance of simplified physically based models for shallow landslide susceptibility

    NASA Astrophysics Data System (ADS)

    Formetta, Giuseppe; Capparelli, Giovanna; Versace, Pasquale

    2016-11-01

    Rainfall-induced shallow landslides can lead to loss of life and significant damage to private and public properties, transportation systems, etc. Predicting locations that might be susceptible to shallow landslides is a complex task and involves many disciplines: hydrology, geotechnical science, geology, hydrogeology, geomorphology, and statistics. Two main approaches are commonly used: statistical or physically based models. Reliable model applications involve automatic parameter calibration, objective quantification of the quality of susceptibility maps, and model sensitivity analyses. This paper presents a methodology to systemically and objectively calibrate, verify, and compare different models and model performance indicators in order to identify and select the models whose behavior is the most reliable for particular case studies.The procedure was implemented in a package of models for landslide susceptibility analysis and integrated in the NewAge-JGrass hydrological model. The package includes three simplified physically based models for landslide susceptibility analysis (M1, M2, and M3) and a component for model verification. It computes eight goodness-of-fit indices by comparing pixel-by-pixel model results and measurement data. The integration of the package in NewAge-JGrass uses other components, such as geographic information system tools, to manage input-output processes, and automatic calibration algorithms to estimate model parameters. The system was applied for a case study in Calabria (Italy) along the Salerno-Reggio Calabria highway, between Cosenza and Altilia. The area is extensively subject to rainfall-induced shallow landslides mainly because of its complex geology and climatology. The analysis was carried out considering all the combinations of the eight optimized indices and the three models. Parameter calibration, verification, and model performance assessment were performed by a comparison with a detailed landslide inventory map for the

  12. Evaluating well-mixed room and near-field-far-field model performance under highly controlled conditions.

    PubMed

    Arnold, Susan F; Shao, Yuan; Ramachandran, Gurumurthy

    2017-06-01

    Exposure judgments made without personal exposure data and based instead on subjective inputs tend to underestimate exposure, with exposure judgment accuracy not significantly more accurate than random chance. Therefore, objective inputs that contribute to more accurate decision making are needed. Models have been shown anecdotally to be useful in accurately predicting exposure but their use in occupational hygiene has been limited. This may be attributable to a general lack of guidance on model selection and use and scant model input data. The lack of systematic evaluation of the models is also an important factor. This research addresses the need to systematically evaluate two widely applicable models, the Well-Mixed Room (WMR) and Near-Field-Far-Field (NF-FF) models. The evaluation, conducted under highly controlled conditions in an exposure chamber, allowed for model inputs to be accurately measured and controlled, generating over 800 pairs of high quality measured and modeled exposure estimates. By varying conditions in the chamber one at a time, model performance across a range of conditions was evaluated using two sets of criteria: the ASTM Standard 5157 and the AIHA Exposure Assessment categorical criteria. Model performance for the WMR model was excellent, with ASTM performance criteria met for 88-97% of the pairs across the three chemicals used in the study, and 96% categorical agreement observed. Model performance for the NF-FF model, impacted somewhat by the size of the chamber was nevertheless good to excellent. NF modeled estimates met modified ASTM criteria for 67-84% of the pairs while 69-91% of FF modeled estimates met these criteria. Categorical agreement was observed for 72% and 96% of NF and FF pairs, respectively. These results support the use of the WMR and NF-FF models in guiding decision making towards improving exposure judgment accuracy.

  13. Evaluation of the complexity and performance of marine planktonic trophic models.

    PubMed

    Leles, Suzana G; Valentin, Jean L; Figueiredo, Gisela M

    2016-01-01

    Planktonic models represent a powerful tool for creating hypotheses and making predictions about the functioning of marine ecosystems. Their complexity varies according to the number of state variables and the choice of functional forms. We evaluated plankton models during the last 15 years (n =145) with the aims of understanding why they differ in complexity, evaluating model robustness, and describing studies of plankton modelling around the globe. We classified models into four groups: Nutrient-Phytoplankton-Zooplankton (NPZ), Nutrient-Phytoplankton-Zooplankton-Detritus (NPZD), Size-Structured (SS) and Plankton-Functional-Type (PFT). Our results revealed that the number of state variables varied according to the question being addressed: NPZ models were more frequently applied in physical-biological studies, while PFT models were more applied for investigating biogeochemical cycles. Most models were based on simple functional forms which neglect important feedback related to control of plankton dynamics. Modelling studies sometimes failed to describe sensitivity analysis, calibration and validation. The importance of testing different functional forms was commonly overlooked, and the lack of empirical data affected the verification of model robustness. Lastly, we highlight the need to develop modelling studies in the Southern Hemisphere, including Brazil, in order to provide predictions that assist the management of marine ecosystems.

  14. Applying the Many-Facet Rasch Model to Evaluate PowerPoint Presentation Performance in Higher Education

    ERIC Educational Resources Information Center

    Basturk, Ramazan

    2008-01-01

    This study investigated the usefulness of the many-facet Rasch model (MFRM) in evaluating the quality of performance related to PowerPoint presentations in higher education. The Rasch Model utilizes item response theory stating that the probability of a correct response to a test item/task depends largely on a single parameter, the ability of the…

  15. Applying the Many-Facet Rasch Model to Evaluate PowerPoint Presentation Performance in Higher Education

    ERIC Educational Resources Information Center

    Basturk, Ramazan

    2008-01-01

    This study investigated the usefulness of the many-facet Rasch model (MFRM) in evaluating the quality of performance related to PowerPoint presentations in higher education. The Rasch Model utilizes item response theory stating that the probability of a correct response to a test item/task depends largely on a single parameter, the ability of the…

  16. A strategic management model for evaluation of health, safety and environmental performance.

    PubMed

    Abbaspour, Majid; Toutounchian, Solmaz; Roayaei, Emad; Nassiri, Parvin

    2012-05-01

    Strategic health, safety, and environmental management system (HSE-MS) involves systematic and cooperative planning in each phase of the lifecycle of a project to ensure that interaction among the industry group, client, contractor, stakeholder, and host community exists with the highest level of health, safety, and environmental standard performances. Therefore, it seems necessary to assess the HSE-MS performance of contractor(s) by a comparative strategic management model with the aim of continuous improvement. The present Strategic Management Model (SMM) has been illustrated by a case study and the results show that the model is a suitable management tool for decision making in a contract environment, especially in oil and gas fields and based on accepted international standards within the framework of management deming cycle. To develop this model, a data bank has been created, which includes the statistical data calculated by converting the HSE performance qualitative data into quantitative values. Based on this fact, the structure of the model has been formed by defining HSE performance indicators according to the HSE-MS model. Therefore, 178 indicators have been selected which have been grouped into four attributes. Model output provides quantitative measures of HSE-MS performance as a percentage of an ideal level with maximum possible score for each attribute. Defining the strengths and weaknesses of the contractor(s) is another capability of this model. On the other hand, this model provides a ranking that could be used as the basis for decision making at the contractors' pre-qualification phase or during the execution of the project.

  17. Evaluating steam trap performance

    SciTech Connect

    Fuller, N.Y.

    1985-08-08

    This paper presents a method for evaluating the performance level of steam traps by preparing an economic analysis of several types to determine the equivalent uniform annual cost. A series of tests on steam traps supplied by six manufacturers provided data for determining the relative efficiencies of each unit. The comparison was made using a program developed for the Texas Instruments T1-59 programmable calculator to evaluate overall steam trap economics.

  18. Modeling and Performance Evaluation of Backoff Misbehaving Nodes in CSMA/CA Networks

    DTIC Science & Technology

    2012-08-01

    range of backoff misbehaviors on network performance in CSMA/CA-based wireless networks. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17...Layer Misbeha- vior in Wireless Networks,” ACM Trans. Information and Systems Security , vol. 11, no. 4, pp. 19:1-19:28, July 2008. [10] S. Choi, K...Park, and C. kwon Kim, “On the Performance Characteristics of WLANs : Revisited,” Proc. ACM SIGMETRICS Int’l Conf. Measurement and Modeling of Computer

  19. Discrete tyre model application for evaluation of vehicle limit handling performance

    NASA Astrophysics Data System (ADS)

    Siramdasu, Y.; Taheri, S.

    2016-11-01

    The goal of this study is twofold, first, to understand the transient and nonlinear effects of anti-lock braking systems (ABS), road undulations and driving dynamics on lateral performance of tyre and second, to develop objective handling manoeuvres and respective metrics to characterise these effects on vehicle behaviour. For studying the transient and nonlinear handling performance of the vehicle, the variations of relaxation length of tyre and tyre inertial properties play significant roles [Pacejka HB. Tire and vehicle dynamics. 3rd ed. Butterworth-Heinemann; 2012]. To accurately simulate these nonlinear effects during high-frequency vehicle dynamic manoeuvres, requires a high-frequency dynamic tyre model (? Hz). A 6 DOF dynamic tyre model integrated with enveloping model is developed and validated using fixed axle high-speed oblique cleat experimental data. Commercially available vehicle dynamics software CarSim® is used for vehicle simulation. The vehicle model was validated by comparing simulation results with experimental sinusoidal steering tests. The validated tyre model is then integrated with vehicle model and a commercial grade rule-based ABS model to perform various objective simulations. Two test scenarios of ABS braking in turn on a smooth road and accelerating in a turn on uneven and smooth roads are considered. Both test cases reiterated that while the tyre is operating in the nonlinear region of slip or slip angle, any road disturbance or high-frequency brake torque input variations can excite the inertial belt vibrations of the tyre. It is shown that these inertial vibrations can directly affect the developed performance metrics and potentially degrade the handling performance of the vehicle.

  20. The Effect of a Recorded Model on Band Students' Performance Self-Evaluations, Achievement, and Attitude

    ERIC Educational Resources Information Center

    Morrison, Steven J.; Montemayor, Mark; Wiltshire, Eric S.

    2004-01-01

    In this study, the effectiveness of recorded models in the context of ensemble rehearsals was examined. Over a 5-week treatment period, directors of three middle/junior high and two high school bands systematically included professional recordings as part of their preparation of selected pieces. Students completed weekly self-evaluation reports…

  1. Evaluating ice sheet model performance over the last glacial cycle using paleo data

    NASA Astrophysics Data System (ADS)

    Robinson, Alexander; Alvarez-Solas, Jorge; Montoya, Marisa

    2015-04-01

    Estimating the past evolution of ice sheets is important for improving our understanding of their role in the Earth system and for quantifying their contribution to sea-level changes. Limited but significant paleo data and proxies are available to give insights into past changes that are valid, at least, on a local scale. Meanwhile, models can be used to provide a mechanistic picture of ice sheet changes. Combined data-model comparisons are therefore useful exercises that allow models to be confronted with real-world information and lead to better understanding of the mechanisms driving changes. In turn, models can potentially be used to validate the data by providing a physical explanation for observed phenomena. Here we focus on the evolution of the Greenland ice sheet through the last glacial cycle to highlight common problems and potential opportunities for data-model comparisons. We will present several examples of how present generation model results are inconsistent with estimates from paleo data, either in terms of the boundary forcing given to the model or the resulting characteristics of the ice sheet. We also propose a set of data-model comparisons as the starting point for developing a more standardized paleo model performance check. Incorporating such a test into modeling efforts could generate new insights in coupled climate - ice sheet modeling.

  2. Modeling and simulation of a VTOL UAV for landing gear performance evaluation

    NASA Astrophysics Data System (ADS)

    Chan, Brendan J.; Sandu, Corina; Ko, Andy; Streett, Tim

    2007-04-01

    A multibody dynamics model of a Vertical Take-off and Landing (VTOL) Unmanned Aerial Vehicle (UAV) is presented in this study. The scope of the project was to investigate a lightweight landing gear which has a stable and robust landing performance. Two original designs of the landing gear for the module of interest have been modeled and analyzed in this study. Two new designs have also been developed, modeled, and analyzed. A limited analysis of the forces that occur in the legs/struts has also been performed, to account for possible failure of the members due to buckling. The model incorporates a sloped surface of deformable terrain for stability analysis of the landing scenarios, and unilateral constraints to model the ground reaction forces upon contact. The lift forces on the UAV are modeled as mathematical relations dependent on the speed of the ducted fan to enable the variation of the impact velocities and the different landing scenarios. The simulations conducted illustrate that initial conditions at landing have a big impact on the stability of the module. The two new designs account for the worst possible scenario, and, for the material properties given, end with a larger weight than the one of the original design with three legs and a ring. Simulation data from several landing scenarios are presented in this paper, with analysis of the difference in performance among the different designs.

  3. Performance Evaluation Process.

    ERIC Educational Resources Information Center

    1998

    This document contains four papers from a symposium on the performance evaluation process and human resource development (HRD). "Assessing the Effectiveness of OJT (On the Job Training): A Case Study Approach" (Julie Furst-Bowe, Debra Gates) is a case study of the effectiveness of OJT in one of a high-tech manufacturing company's product…

  4. Modeling and evaluation of hand-eye coordination of surgical robotic system on task performance.

    PubMed

    Gao, Yuanqian; Wang, Shuxin; Li, Jianmin; Li, Aimin; Liu, Hongbin; Xing, Yuan

    2017-05-04

    Robotic-assisted minimally invasive surgery changes the direct hand and eye coordination in traditional surgery to indirect instrument and camera coordination, which affects the ergonomics, operation performance, and safety. A camera, two instruments, and a target, as the descriptors, are used to construct the workspace correspondence and geometrical relationships in a surgical operation. A parametric model with a set of parameters is proposed to describe the hand-eye coordination of the surgical robot. From the results, optimal values and acceptable ranges of these parameters are identified from two tasks. A 90° viewing angle had the longest completion time; 60° instrument elevation angle and 0° deflection angle had better performance; there is no significant difference among manipulation angles and observing distances on task performance. This hand-eye coordination model provides evidence for robotic design, surgeon training, and robotic initialization to achieve dexterous and safe manipulation in surgery. Copyright © 2017 John Wiley & Sons, Ltd.

  5. A 4-Step Process Evaluation Model to Assess the Success of Performance Based Logistics Contracts

    DTIC Science & Technology

    2009-03-01

    2007, pp 74-116. Kaplan , R., S., Norton , D., P., “The Balanced Scorecard : Translating Strategy into Action”, New York: Harvard Business School...Defining desired levels of performance: Kaplan and Norton (1996) offered an integrated approach from defining the mission of the company to...d) “The scarcest resource in an organization is a manager’s time.” ( Kaplan and Cooper,. 1997, p.144) The evaluation of the metrics individually

  6. A parametric analysis microcomputer model for evaluating the thermodynamic performance of a reciprocating Brayton cycle engine

    SciTech Connect

    Tsongas, G.A. ); White, T.J. )

    1989-10-01

    A Brayton open-cycle engine is under development. It operates similarly to a gas turbine engine, but uses reciprocating piston compressor and expander components. The design appears to have a number of advantages, including multifuel capability, the potential for lower cost, and the ability to be scaled to small sizes without significant loss in efficiency. An interactive microcomputer model has been developed that analyzes the thermodynamic performance of the engine. The model incorporates all the important irreversibilities found in piston devices, including heat transfer, mechanical friction, pressure losses, and mass loss and recirculation. There are 38 input parameters to the model. Key independent operating parameters are maximum temperature, compressor rpm, and pressure ratio. The development of the model and its assumptions are outlined in this paper. The emphasis is on model applications.

  7. Performance evaluation model of a pilot food waste collection system in Suzhou City, China.

    PubMed

    Wen, Zongguo; Wang, Yuanjia; De Clercq, Djavan

    2015-05-01

    This paper analyses the food waste collection and transportation (C&T) system in a pilot project in Suzhou by using a novel performance evaluation method. The method employed to conduct this analysis involves a unified performance evaluation index containing qualitative and quantitative indicators applied to data from Suzhou City. Two major inefficiencies were identified: a) low system efficiency due to insufficient processing capacity of commercial food waste facilities; and b) low waste resource utilization due to low efficiency of manual sorting. The performance evaluation indicated that the pilot project collection system's strong points included strong economics, low environmental impact and low social impact. This study also shows that Suzhou's integrated system has developed a comprehensive body of laws and clarified regulatory responsibilities for each of the various government departments to solve the problems of commercial food waste management. Based on Suzhou's experience, perspectives and lessons can be drawn for other cities and areas where food waste management systems are in the planning stage, or are encountering operational problems.

  8. Analytical performance evaluation of SAR ATR with inaccurate or estimated models

    NASA Astrophysics Data System (ADS)

    DeVore, Michael D.

    2004-09-01

    Hypothesis testing algorithms for automatic target recognition (ATR) are often formulated in terms of some assumed distribution family. The parameter values corresponding to a particular target class together with the distribution family constitute a model for the target's signature. In practice such models exhibit inaccuracy because of incorrect assumptions about the distribution family and/or because of errors in the assumed parameter values, which are often determined experimentally. Model inaccuracy can have a significant impact on performance predictions for target recognition systems. Such inaccuracy often causes model-based predictions that ignore the difference between assumed and actual distributions to be overly optimistic. This paper reports on research to quantify the effect of inaccurate models on performance prediction and to estimate the effect using only trained parameters. We demonstrate that for large observation vectors the class-conditional probabilities of error can be expressed as a simple function of the difference between two relative entropies. These relative entropies quantify the discrepancies between the actual and assumed distributions and can be used to express the difference between actual and predicted error rates. Focusing on the problem of ATR from synthetic aperture radar (SAR) imagery, we present estimators of the probabilities of error in both ideal and plug-in tests expressed in terms of the trained model parameters. These estimators are defined in terms of unbiased estimates for the first two moments of the sample statistic. We present an analytical treatment of these results and include demonstrations from simulated radar data.

  9. Evacuation performance evaluation tool.

    PubMed

    Farra, Sharon; Miller, Elaine T; Gneuhs, Matthew; Timm, Nathan; Li, Gengxin; Simon, Ashley; Brady, Whittney

    2016-01-01

    Hospitals conduct evacuation exercises to improve performance during emergency events. An essential aspect in this process is the creation of reliable and valid evaluation tools. The objective of this article is to describe the development and implications of a disaster evacuation performance tool that measures one portion of the very complex process of evacuation. Through the application of the Delphi technique and DeVellis's framework, disaster and neonatal experts provided input in developing this performance evaluation tool. Following development, content validity and reliability of this tool were assessed. Large pediatric hospital and medical center in the Midwest. The tool was pilot tested with an administrative, medical, and nursing leadership group and then implemented with a group of 68 healthcare workers during a disaster exercise of a neonatal intensive care unit (NICU). The tool has demonstrated high content validity with a scale validity index of 0.979 and inter-rater reliability G coefficient (0.984, 95% CI: 0.948-0.9952). The Delphi process based on the conceptual framework of DeVellis yielded a psychometrically sound evacuation performance evaluation tool for a NICU.

  10. An evaluation of the predictive performance of distributional models for flora and fauna in north-east New South Wales.

    PubMed

    Pearce, J; Ferrier, S; Scotts, D

    2001-06-01

    To use models of species distributions effectively in conservation planning, it is important to determine the predictive accuracy of such models. Extensive modelling of the distribution of vascular plant and vertebrate fauna species within north-east New South Wales has been undertaken by linking field survey data to environmental and geographical predictors using logistic regression. These models have been used in the development of a comprehensive and adequate reserve system within the region. We evaluate the predictive accuracy of models for 153 small reptile, arboreal marsupial, diurnal bird and vascular plant species for which independent evaluation data were available. The predictive performance of each model was evaluated using the relative operating characteristic curve to measure discrimination capacity. Good discrimination ability implies that a model's predictions provide an acceptable index of species occurrence. The discrimination capacity of 89% of the models was significantly better than random, with 70% of the models providing high levels of discrimination. Predictions generated by this type of modelling therefore provide a reasonably sound basis for regional conservation planning. The discrimination ability of models was highest for the less mobile biological groups, particularly the vascular plants and small reptiles. In the case of diurnal birds, poor performing models tended to be for species which occur mainly within specific habitats not well sampled by either the model development or evaluation data, highly mobile species, species that are locally nomadic or those that display very broad habitat requirements. Particular care needs to be exercised when employing models for these types of species in conservation planning.

  11. Evaluating the Sensitivity of Agricultural Model Performance to Different Climate Inputs: Supplemental Material

    NASA Technical Reports Server (NTRS)

    Glotter, Michael J.; Ruane, Alex C.; Moyer, Elisabeth J.; Elliott, Joshua W.

    2015-01-01

    Projections of future food production necessarily rely on models, which must themselves be validated through historical assessments comparing modeled and observed yields. Reliable historical validation requires both accurate agricultural models and accurate climate inputs. Problems with either may compromise the validation exercise. Previous studies have compared the effects of different climate inputs on agricultural projections but either incompletely or without a ground truth of observed yields that would allow distinguishing errors due to climate inputs from those intrinsic to the crop model. This study is a systematic evaluation of the reliability of a widely used crop model for simulating U.S. maize yields when driven by multiple observational data products. The parallelized Decision Support System for Agrotechnology Transfer (pDSSAT) is driven with climate inputs from multiple sources reanalysis, reanalysis that is bias corrected with observed climate, and a control dataset and compared with observed historical yields. The simulations show that model output is more accurate when driven by any observation-based precipitation product than when driven by non-bias-corrected reanalysis. The simulations also suggest, in contrast to previous studies, that biased precipitation distribution is significant for yields only in arid regions. Some issues persist for all choices of climate inputs: crop yields appear to be oversensitive to precipitation fluctuations but under sensitive to floods and heat waves. These results suggest that the most important issue for agricultural projections may be not climate inputs but structural limitations in the crop models themselves.

  12. Evaluating the performance of thermal sensation prediction with a biophysical model.

    PubMed

    Schweiker, M; Kingma, B R M; Wagner, A

    2017-09-01

    Neutral thermal sensation is expected for a human body in heat balance in near-steady-state thermal environments. The physiological thermoneutral zone (TNZ) is defined as the range of operative temperatures where the body can maintain such heat balance by actively adjusting body tissue insulation, but without regulatory increases in metabolic rate or sweating. These basic principles led to the hypothesis that thermal sensation relates to the operative temperature distance from the thermoneutral centroid (dTNZop ). This hypothesis was confirmed by data from respiratory climate chamber experiments. This paper explores the potential of such biophysical model for the prediction of thermal sensation under increased contextual variance. Data (798 votes, 47 participants) from a controlled office environment were used to analyze the predictive performance of the dTNZop model. The results showed a similar relationship between dTNZop and thermal sensation between the dataset used here and the previously used dataset. The predictive performance had the same magnitude as that of the PMV model; however, potential benefits of using a biophysical model are discussed. In conclusion, these findings confirm the potential of the biophysical model with regard to the understanding and prediction of human thermal sensation. Further work remains to make benefit of its full potential. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Evaluation of Model Results and Measured Performance of Net-Zero Energy Homes in Hawaii: Preprint

    SciTech Connect

    Norton, P.; Kiatreungwattana, K.; Kelly, K. J.

    2013-03-01

    The Kaupuni community consists of 19 affordable net-zero energy homes that were built within the Waianae Valley of Oahu, Hawaii in 2011. The project was developed for the native Hawaiian community led by the Department of Hawaiian Homelands. This paper presents a comparison of the modeled and measured energy performance of the homes. Over the first year of occupancy, the community as a whole performed within 1% of the net-zero energy goals. The data show a range of performance from house to house with the majority of the homes consistently near or exceeding net-zero, while a few fall short of the predicted net-zero energy performance. The impact of building floor plan, weather, and cooling set point on this comparison is discussed. The project demonstrates the value of using building energy simulations as a tool to assist the project to achieve energy performance goals. Lessons learned from the energy performance monitoring has had immediate benefits in providing feedback to the homeowners, and will be used to influence future energy efficient designs in Hawaii and other tropical climates.

  14. Evaluating the performance of ENVI-met model in diurnal cycles for different meteorological conditions

    NASA Astrophysics Data System (ADS)

    Acero, Juan A.; Arrizabalaga, Jon

    2016-11-01

    Urban areas are known to modify meteorological variables producing important differences in small spatial scales (i.e. microscale). These affect human thermal comfort conditions and the dispersion of pollutants, especially those emitted inside the urban area, which finally influence quality of life and the use of public open spaces. In this study, the diurnal evolution of meteorological variables measured in four urban spaces is compared with the results provided by ENVI-met (v 4.0). Measurements were carried out during 3 days with different meteorological conditions in Bilbao in the north of the Iberian Peninsula. The evaluation of the model accuracy (i.e. the degree to which modelled values approach measured values) was carried out with several quantitative difference metrics. The results for air temperature and humidity show a good agreement of measured and modelled values independently of the regional meteorological conditions. However, in the case of mean radiant temperature and wind speed, relevant differences are encountered highlighting the limitation of the model to estimate these meteorological variables precisely during diurnal cycles, in the considered evaluation conditions (sites and weather).

  15. Performance Evaluation of Color Models in the Fusion of Functional and Anatomical Images.

    PubMed

    Ganasala, Padma; Kumar, Vinod; Prasad, A D

    2016-05-01

    Fusion of the functional image with an anatomical image provides additional diagnostic information. It is widely used in diagnosis, treatment planning, and follow-up of oncology. Functional image is a low-resolution pseudo color image representing the uptake of radioactive tracer that gives the important metabolic information. Whereas, anatomical image is a high-resolution gray scale image that gives structural details. Fused image should consist of all the anatomical details without any changes in the functional content. This is achieved through fusion in de-correlated color model and the choice of color model has greater impact on the fusion outcome. In the present work, suitability of different color models for functional and anatomical image fusion is studied. After converting the functional image into de-correlated color model, the achromatic component of functional image is fused with an anatomical image by using proposed nonsubsampled shearlet transform (NSST) based image fusion algorithm to get new achromatic component with all the anatomical details. This new achromatic and original chromatic channels of functional image are converted to RGB format to get fused functional and anatomical image. Fusion is performed in different color models. Different cases of SPECT-MRI images are used for this color model study. Based on visual and quantitative analysis of fused images, the best color model for the stated purpose is determined.

  16. On shrinkage and model extrapolation in the evaluation of clinical center performance

    PubMed Central

    Varewyck, Machteld; Goetghebeur, Els; Eriksson, Marie; Vansteelandt, Stijn

    2014-01-01

    We consider statistical methods for benchmarking clinical centers based on a dichotomous outcome indicator. Borrowing ideas from the causal inference literature, we aim to reveal how the entire study population would have fared under the current care level of each center. To this end, we evaluate direct standardization based on fixed versus random center effects outcome models that incorporate patient-specific baseline covariates to adjust for differential case-mix. We explore fixed effects (FE) regression with Firth correction and normal mixed effects (ME) regression to maintain convergence in the presence of very small centers. Moreover, we study doubly robust FE regression to avoid outcome model extrapolation. Simulation studies show that shrinkage following standard ME modeling can result in substantial power loss relative to the considered alternatives, especially for small centers. Results are consistent with findings in the analysis of 30-day mortality risk following acute stroke across 90 centers in the Swedish Stroke Register. PMID:24812420

  17. Performance evaluation of continuity of care records (CCRs): parsing models in a mobile health management system.

    PubMed

    Chen, Hung-Ming; Liou, Yong-Zan

    2014-10-01

    In a mobile health management system, mobile devices act as the application hosting devices for personal health records (PHRs) and the healthcare servers construct to exchange and analyze PHRs. One of the most popular PHR standards is continuity of care record (CCR). The CCR is expressed in XML formats. However, parsing is an expensive operation that can degrade XML processing performance. Hence, the objective of this study was to identify different operational and performance characteristics for those CCR parsing models including the XML DOM parser, the SAX parser, the PULL parser, and the JSON parser with regard to JSON data converted from XML-based CCR. Thus, developers can make sensible choices for their target PHR applications to parse CCRs when using mobile devices or servers with different system resources. Furthermore, the simulation experiments of four case studies are conducted to compare the parsing performance on Android mobile devices and the server with large quantities of CCR data.

  18. A Predictive Performance Model to Evaluate the Contention Cost in Application Servers

    SciTech Connect

    Chen, Shiping; Gorton, Ian )

    2002-12-04

    In multi-tier enterprise systems, application servers are key components that implement business logic and provide application services. To support a large number of simultaneous accesses from clients over the Internet and intranet, most application servers use replication and multi-threading to handle concurrent requests. While multiple processes and multiple threads enhance the processing bandwidth of servers, they also increase the contention for resources in application servers. This paper investigates this issue empirically based on a middleware benchmark. A cost model is proposed to estimate the overall performance of application servers, including the contention overhead. This model is then used to determine the optimal degree of the concurrency of application servers for a specific client load. A case study based on CORBA is presented to validate our model and demonstrate its application.

  19. Modeling and Evaluating Pilot Performance in NextGen: Review of and Recommendations Regarding Pilot Modeling Efforts, Architectures, and Validation Studies

    NASA Technical Reports Server (NTRS)

    Wickens, Christopher; Sebok, Angelia; Keller, John; Peters, Steve; Small, Ronald; Hutchins, Shaun; Algarin, Liana; Gore, Brian Francis; Hooey, Becky Lee; Foyle, David C.

    2013-01-01

    NextGen operations are associated with a variety of changes to the national airspace system (NAS) including changes to the allocation of roles and responsibilities among operators and automation, the use of new technologies and automation, additional information presented on the flight deck, and the entire concept of operations (ConOps). In the transition to NextGen airspace, aviation and air operations designers need to consider the implications of design or system changes on human performance and the potential for error. To ensure continued safety of the NAS, it will be necessary for researchers to evaluate design concepts and potential NextGen scenarios well before implementation. One approach for such evaluations is through human performance modeling. Human performance models (HPMs) provide effective tools for predicting and evaluating operator performance in systems. HPMs offer significant advantages over empirical, human-in-the-loop testing in that (1) they allow detailed analyses of systems that have not yet been built, (2) they offer great flexibility for extensive data collection, (3) they do not require experimental participants, and thus can offer cost and time savings. HPMs differ in their ability to predict performance and safety with NextGen procedures, equipment and ConOps. Models also vary in terms of how they approach human performance (e.g., some focus on cognitive processing, others focus on discrete tasks performed by a human, while others consider perceptual processes), and in terms of their associated validation efforts. The objectives of this research effort were to support the Federal Aviation Administration (FAA) in identifying HPMs that are appropriate for predicting pilot performance in NextGen operations, to provide guidance on how to evaluate the quality of different models, and to identify gaps in pilot performance modeling research, that could guide future research opportunities. This research effort is intended to help the FAA

  20. Performance Evaluation and Modeling of Erosion Resistant Turbine Engine Thermal Barrier Coatings

    NASA Technical Reports Server (NTRS)

    Miller, Robert A.; Zhu, Dongming; Kuczmarski, Maria

    2008-01-01

    The erosion resistant turbine thermal barrier coating system is critical to the rotorcraft engine performance and durability. The objective of this work was to determine erosion resistance of advanced thermal barrier coating systems under simulated engine erosion and thermal gradient environments, thus validating a new thermal barrier coating turbine blade technology for future rotorcraft applications. A high velocity burner rig based erosion test approach was established and a new series of rare earth oxide- and TiO2/Ta2O5- alloyed, ZrO2-based low conductivity thermal barrier coatings were designed and processed. The low conductivity thermal barrier coating systems demonstrated significant improvements in the erosion resistance. A comprehensive model based on accumulated strain damage low cycle fatigue is formulated for blade erosion life prediction. The work is currently aiming at the simulated engine erosion testing of advanced thermal barrier coated turbine blades to establish and validate the coating life prediction models.

  1. Evaluation of a model to predict anomalous-observer performance with the 100-hue test.

    PubMed

    Moreland, Jack; Cheung, Vien; Westland, Stephen

    2014-04-01

    Two subjects, protanomalous and deuteranomalous, performed the Farnsworth-Munsell 100-hue test with and without prescribed ColorView spectacle aids under simulated D65 lighting. Errors were greater with aids than without. Using spectral measurements of test reflectance, aid transmittance and lighting, chromaticities of the 100-hue caps were calculated with and without aids in the uniform chromaticity diagrams for protanomaly and protanomaly [Ophthalmol. Physiol. Opt.30, 685 (2010).]. Errors were modeled from chromatic spacing on a smoothed 100-hue locus together with a distractor term, derived from the distances of raw data from that locus. Good correspondence was found between the measured test and model profiles for the major maxima as well as other aspects of shape and position.

  2. Modeling and performance evaluation of a robotic treatment couch for tumor tracking.

    PubMed

    Jöhl, Alexander; Lang, Stephanie; Ehrbar, Stefanie; Guckenberger, Matthias; Klöck, Stephan; Meboldt, Mirko; Schmid Daners, Marianne

    2016-10-01

    Tumor motion during radiation therapy increases the irradiation of healthy tissue. However, this problem may be mitigated by moving the patient via the treatment couch such that the tumor motion relative to the beam is minimized. The treatment couch poses limitations to the potential mitigation, thus the performance of the Protura (CIVCO) treatment couch was characterized and numerically modeled. The unknown parameters were identified using chirp signals and verified with one-dimensional tumor tracking. The Protura tracked chirp signals well up to 0.2 Hz in both longitudinal and vertical directions. If only the vertical or only the longitudinal direction was tracked, the Protura tracked well up to 0.3 Hz. However, there was unintentional yet substantial lateral motion in the former case. And during vertical motion, the extension caused rotation of the Protura around the lateral axis. The numerical model matched the Protura up to 0.3 Hz. Even though the Protura was designed for static positioning, it was able to reduce the tumor motion by 69% (median). The correlation coefficient between the tumor motion reductions of the Protura and the model was 0.99. Therefore, the model allows tumor-tracking results of the Protura to be predicted.

  3. Evaluation of Round Window Stimulation Performance in Otosclerosis Using Finite Element Modeling

    PubMed Central

    Yang, Shanguo; Xu, Dan; Liu, Xiaole

    2016-01-01

    Round window (RW) stimulation is a new type of middle ear implant's application for treating patients with middle ear disease, such as otosclerosis. However, clinical outcomes show a substantial degree of variability. One source of variability is the variation in the material properties of the ear components caused by the disease. To investigate the influence of the otosclerosis on the performance of the RW stimulation, a human ear finite element model including middle ear and cochlea was established based on a set of microcomputerized tomography section images of a human temporal bone. Three characteristic changes of the otosclerosis in the auditory system were simulated in the FE model: stapedial annular ligament stiffness enlargement, stapedial abnormal bone growth, and partial fixation of the malleus. The FE model was verified by comparing the model-predicted results with published experimental measurements. The equivalent sound pressure (ESP) of RW stimulation was calculated via comparing the differential intracochlear pressure produced by the RW stimulation and the normal eardrum sound stimulation. The results show that the increase of stapedial annular ligament and partial fixation of the malleus decreases RW stimulation's ESP prominently at lower frequencies. In contrast, the stapedial abnormal bone growth deteriorates RW stimulation's ESP severely at higher frequencies. PMID:27034709

  4. Evaluation of Round Window Stimulation Performance in Otosclerosis Using Finite Element Modeling.

    PubMed

    Yang, Shanguo; Xu, Dan; Liu, Xiaole

    2016-01-01

    Round window (RW) stimulation is a new type of middle ear implant's application for treating patients with middle ear disease, such as otosclerosis. However, clinical outcomes show a substantial degree of variability. One source of variability is the variation in the material properties of the ear components caused by the disease. To investigate the influence of the otosclerosis on the performance of the RW stimulation, a human ear finite element model including middle ear and cochlea was established based on a set of microcomputerized tomography section images of a human temporal bone. Three characteristic changes of the otosclerosis in the auditory system were simulated in the FE model: stapedial annular ligament stiffness enlargement, stapedial abnormal bone growth, and partial fixation of the malleus. The FE model was verified by comparing the model-predicted results with published experimental measurements. The equivalent sound pressure (ESP) of RW stimulation was calculated via comparing the differential intracochlear pressure produced by the RW stimulation and the normal eardrum sound stimulation. The results show that the increase of stapedial annular ligament and partial fixation of the malleus decreases RW stimulation's ESP prominently at lower frequencies. In contrast, the stapedial abnormal bone growth deteriorates RW stimulation's ESP severely at higher frequencies.

  5. Design, modeling, and performance evaluation of a novel large-motion SMA actuator

    NASA Astrophysics Data System (ADS)

    Shahinpoor, Mohsen; Wang, Guoping

    1995-05-01

    Presented are a number of novel designs for large-motion shape-memory alloy (SMA) actuators that may minimize the performance constraints associated with such actuators. Shape-memory alloy (SMA) actuators suffer from two performance constraints, namely small strains (epsilon) , such that (epsilon) models are presented for large motion SMA actuators. The dynamic modeling is preceded by a model of a small motion SMA linear actuator. This model considers the dynamic response of contractile fiber bundles embedded in or around elastic springs that are either linear helical compression springs or hyperelastic springs such as rubber-like materials. The proposed theory presents a description of such processes for resilient shape-memory alloy fiber bundles. We consider the fiber bundle of SMA to be either in a serial configuration with a linear tension spring or a parallel configuration circumscribed inside a helical compression spring with flat heads or in parallel with a number of helical compression spring, end-capped by two parallel circular plates with embedded electrodes to which the ends of the SMA fibers are secured. Thus, the fibers can be electrically heated and subsequently contracted to either expand the tension spring or compress the helical compression spring back and forth. Design details are first described. In essence the dynamic behavior of the actuator depends on the frictional

  6. Performance Evaluation of O-Ring Seals in Model 9975 Packaging Assemblies (U)

    SciTech Connect

    Skidmore, Eric

    1998-12-28

    The Materials Consultation Group of SRTC has completed a review of existing literature and data regarding the useable service life of Viton{reg_sign} GLT fluoroelastomer O-rings currently used in the Model 9975 packaging assemblies. Although the shipping and transportation period is normally limited to 2 years, it is anticipated that these packages will be used for longer-term storage of Pu-bearing materials in KAMS (K-Area Materials Storage) prior to processing or disposition in the APSF (Actinide Packaging and Storage Facility). Based on the service conditions and review of available literature, Materials Consultation concludes that there is sufficient existing data to establish the technical basis for storage of Pu-bearing materials using Parker Seals O-ring compound V835-75 (or equivalent) for up to 10 years following the 2-year shipping period. Although significant physical deterioration of the O-rings and release of product is not expected, definite changes in physical properties will occur. However, due to the complex relationship between elastomer formulation, seal properties, and competing degradation mechanisms, the actual degree of property variation and impact upon seal performance is difficult to predict. Therefore, accelerated aging and/or surveillance programs are recommended to validate the assumptions outlined in this report and to assess the long-term performance of O-ring seals under actual service conditions. Such programs could provide a unique opportunity to develop nonexistent long-term performance data, as well as address storage extension issues if necessary.

  7. Performance evaluation of ionospheric time delay forecasting models using GPS observations at a low-latitude station

    NASA Astrophysics Data System (ADS)

    Sivavaraprasad, G.; Venkata Ratnam, D.

    2017-07-01

    Ionospheric delay is one of the major atmospheric effects on the performance of satellite-based radio navigation systems. It limits the accuracy and availability of Global Positioning System (GPS) measurements, related to critical societal and safety applications. The temporal and spatial gradients of ionospheric total electron content (TEC) are driven by several unknown priori geophysical conditions and solar-terrestrial phenomena. Thereby, the prediction of ionospheric delay is challenging especially over Indian sub-continent. Therefore, an appropriate short/long-term ionospheric delay forecasting model is necessary. Hence, the intent of this paper is to forecast ionospheric delays by considering day to day, monthly and seasonal ionospheric TEC variations. GPS-TEC data (January 2013-December 2013) is extracted from a multi frequency GPS receiver established at K L University, Vaddeswaram, Guntur station (geographic: 16.37°N, 80.37°E; geomagnetic: 7.44°N, 153.75°E), India. An evaluation, in terms of forecasting capabilities, of three ionospheric time delay models - an Auto Regressive Moving Average (ARMA) model, Auto Regressive Integrated Moving Average (ARIMA) model, and a Holt-Winter's model is presented. The performances of these models are evaluated through error measurement analysis during both geomagnetic quiet and disturbed days. It is found that, ARMA model is effectively forecasting the ionospheric delay with an accuracy of 82-94%, which is 10% more superior to ARIMA and Holt-Winter's models. Moreover, the modeled VTEC derived from International Reference Ionosphere, IRI (IRI-2012) model and new global TEC model, Neustrelitz TEC Model (NTCM-GL) have compared with forecasted VTEC values of ARMA, ARIMA and Holt-Winter's models during geomagnetic quiet days. The forecast results are indicating that ARMA model would be useful to set up an early warning system for ionospheric disturbances at low latitude regions.

  8. Performance evaluation of WAVEWATCH III model in the Persian Gulf using different wind resources

    NASA Astrophysics Data System (ADS)

    Kazeminezhad, Mohammad Hossein; Siadatmousavi, Seyed Mostafa

    2017-07-01

    The third-generation wave model, WAVEWATCH III, was employed to simulate bulk wave parameters in the Persian Gulf using three different wind sources: ERA-Interim, CCMP, and GFS-Analysis. Different formulations for whitecapping term and the energy transfer from wind to wave were used, namely the Tolman and Chalikov (J Phys Oceanogr 26:497-518, 1996), WAM cycle 4 (BJA and WAM4), and Ardhuin et al. (J Phys Oceanogr 40(9):1917-1941, 2010) (TEST405 and TEST451 parameterizations) source term packages. The obtained results from numerical simulations were compared to altimeter-derived significant wave heights and measured wave parameters at two stations in the northern part of the Persian Gulf through statistical indicators and the Taylor diagram. Comparison of the bulk wave parameters with measured values showed underestimation of wave height using all wind sources. However, the performance of the model was best when GFS-Analysis wind data were used. In general, when wind veering from southeast to northwest occurred, and wind speed was high during the rotation, the model underestimation of wave height was severe. Except for the Tolman and Chalikov (J Phys Oceanogr 26:497-518, 1996) source term package, which severely underestimated the bulk wave parameters during stormy condition, the performances of other formulations were practically similar. However, in terms of statistics, the Ardhuin et al. (J Phys Oceanogr 40(9):1917-1941, 2010) source terms with TEST405 parameterization were the most successful formulation in the Persian Gulf when compared to in situ and altimeter-derived observations.

  9. Performance Evaluation Test of the Orbit Screen Model 68A and the Komplet Model 48-25 Rock Crusher

    DTIC Science & Technology

    2008-08-01

    screen and on a Komplet Italia , s.r.l., Model 48-25 rock crusher. The test was conducted during August 2008 at a U.S. Army test site in central... Italia , s.r.l., Model 48-25 Rock Crusher.......................................................... 2 2.3 ASV SR-80 Rubber-Tracked Skid-Steer Loader... Italia , s.r.l., Rock Crusher Testing ......................................................................... 16 5.1 Crushing Performance Test

  10. Scalable modeling and performance evaluation of dynamic RED router using fluid-flow approximation

    NASA Astrophysics Data System (ADS)

    Ohsaki, Hiroyuki; Yamamoto, Hideyuki; Imase, Makoto

    2005-10-01

    In recent years, AQM (Active Queue Management) mechanisms, which support the end-to-end congestion control mechanism of TCP (Transmission Control Protocol), have been widely studied in the literature. AQM mechanism is a congestion controller at a router for suppressing and stabilizing its queue length (i.e., the number of packets in the buffer) by actively discarding arriving packets. Although a number of AQM mechanisms have been proposed, behaviors of those AQM mechanisms other than RED (Random Early Detection) have not been fully investigated. In this paper, using fluid-flow approximation, we analyze steady state behavior of DRED (Dynamic RED), which is designed with a control theoretic approach. More specifically, we model several network components such as congestion control mechanism of TCP, DRED router, and link propagation delay as independent SISO (Single-Input Single-Output) continuous-time systems. By interconnecting those SISO models, we obtain a continuous-time model for the entire network. Unlike other fluid-based modeling approaches, our analytic approach is scalable; our analytic approach is scalable in terms of the number of TCP connections and DRED routers since both input and output of all continuous-time systems are uniformly defined as a packet transmission rate. By performing steady-state analysis, we derive TCP throughput, average queue length of DRED router, and packet loss probability. Through several numerical examples, we quantitatively show that DRED has an intrinsic problem in high-speed networks; i.e., DRED cannot stabilize its queue length when the bottleneck link bandwidth is high. We also validate accuracy of our analytic approach by comparing analytic results with simulation ones.

  11. A parametric multiclass Bayes error estimator for the multispectral scanner spatial model performance evaluation

    NASA Technical Reports Server (NTRS)

    Mobasseri, B. G.; Mcgillem, C. D.; Anuta, P. E. (Principal Investigator)

    1978-01-01

    The author has identified the following significant results. The probability of correct classification of various populations in data was defined as the primary performance index. The multispectral data being of multiclass nature as well, required a Bayes error estimation procedure that was dependent on a set of class statistics alone. The classification error was expressed in terms of an N dimensional integral, where N was the dimensionality of the feature space. The multispectral scanner spatial model was represented by a linear shift, invariant multiple, port system where the N spectral bands comprised the input processes. The scanner characteristic function, the relationship governing the transformation of the input spatial, and hence, spectral correlation matrices through the systems, was developed.

  12. Evaluation of tests of central nervous system performance after hypoxemia for a model for cognitive impairment.

    PubMed

    van der Post, J; Noordzij, L A W; de Kam, M L; Blauw, G J; Cohen, A F; van Gerven, J M A

    2002-12-01

    The sensitivity of several neurophysiological and cognitive tests to different levels of hypoxia was investigated. Cerebral hypoxia in healthy volunteers may be a disease model for dementia or other forms of brain dysfunction. Twelve healthy subjects were included in a randomized, single-blind, placebo-controlled, three-period cross-over trial. They received three air/N2 gas mixtures via mask breathing [aimed at peripheral oxygen saturation (SPO2) values of > 97% (placebo), 90% and 80%, with normal end-tidal CO2]. Central nervous system effects were tested regularly for 130 min by saccadic and smooth pursuit eye movements, electro-encephalogram, visual analogue scales and cognitive tests. Treatments were well tolerated. Compared to SPO2 90%, SPO2 80% reduced saccadic peak velocity by 16.4 degrees/s [confidence interval (CI) -26.3, -6.4], increased occipital delta power by 14.3% (CI 3.6, 25.1), and significantly increased most cognitive reaction times. SPO2 80% also decreased correct responses for the binary choice task and serial word recognition [-1.3 (-2.2, -0.3) and -3.5 (-6.2, -0.8), respectively] compared to SPO2 90%. Cognitive performance was decreased by SPO2 80% and increased by SPO2 90% compared to placebo. Sensitive effect measurements can be identified for these interventions. The applicability as a model for cognitive impairment should be investigated further.

  13. Integrated DEA Models and Grey System Theory to Evaluate Past-to-Future Performance: A Case of Indian Electricity Industry

    PubMed Central

    Wang, Chia-Nan; Tran, Thanh-Tuyen

    2015-01-01

    The growth of economy and population together with the higher demand in energy has created many concerns for the Indian electricity industry whose capacity is at 211 gigawatts mostly in coal-fired plants. Due to insufficient fuel supply, India suffers from a shortage of electricity generation, leading to rolling blackouts; thus, performance evaluation and ranking the industry turn into significant issues. By this study, we expect to evaluate the rankings of these companies under control of the Ministry of Power. Also, this research would like to test if there are any significant differences between the two DEA models: Malmquist nonradial and Malmquist radial. Then, one advance model of MPI would be chosen to see these companies' performance in recent years and next few years by using forecasting results of Grey system theory. Totally, the realistic data 14 are considered to be in this evaluation after the strict selection from the whole industry. The results found that all companies have not shown many abrupt changes on their scores, and it is always not consistently good or consistently standing out, which demonstrated the high applicable usability of the integrated methods. This integrated numerical research gives a better “past-present-future” insights into performance evaluation in Indian electricity industry. PMID:25821854

  14. Integrated DEA models and grey system theory to evaluate past-to-future performance: a case of Indian electricity industry.

    PubMed

    Wang, Chia-Nan; Nguyen, Nhu-Ty; Tran, Thanh-Tuyen

    2015-01-01

    The growth of economy and population together with the higher demand in energy has created many concerns for the Indian electricity industry whose capacity is at 211 gigawatts mostly in coal-fired plants. Due to insufficient fuel supply, India suffers from a shortage of electricity generation, leading to rolling blackouts; thus, performance evaluation and ranking the industry turn into significant issues. By this study, we expect to evaluate the rankings of these companies under control of the Ministry of Power. Also, this research would like to test if there are any significant differences between the two DEA models: Malmquist nonradial and Malmquist radial. Then, one advance model of MPI would be chosen to see these companies' performance in recent years and next few years by using forecasting results of Grey system theory. Totally, the realistic data 14 are considered to be in this evaluation after the strict selection from the whole industry. The results found that all companies have not shown many abrupt changes on their scores, and it is always not consistently good or consistently standing out, which demonstrated the high applicable usability of the integrated methods. This integrated numerical research gives a better "past-present-future" insights into performance evaluation in Indian electricity industry.

  15. Simulation of air quality over Central-Eastern Europe - Performance evaluation of WRF-CAMx modelling system

    NASA Astrophysics Data System (ADS)

    Maciejewska, Katarzyna; Juda-Rezler, Katarzyna; Reizer, Magdalena

    2013-04-01

    The main goal of presented work is to evaluate the accuracy of modelling the atmospheric transport and transformation on regional scale, performed with 25 km grid spacing. The coupled Mesoscale Weather Model - Chemical Transport Model (CTM) has been applied for Europe under European-American AQMEII project (Air Quality Modelling Evaluation International Initiative - http://aqmeii.jrc.ec.europa.eu/). The modelling domain was centered over Denmark (57.00°N, 10.00°E) with 172 x 172 grid points in x and y direction. The map projection choice was Lambert conformal. In the applied modelling system the Comprehensive Air Quality Model with extensions (CAMx) from ENVIRON International Corporation (Novato, California) was coupled off-line to the Weather Research and Forecasting (WRF), developed by National Center for Atmospheric Research (NCAR). WRF-CAMx simulations have been carried out for 2006. The anthropogenic emisions database has been provided by TNO (Netherlands Organisation for Applied Scientific Research) under AQMEII initiative. Area and line emissions were proceeded by emission model EMIL (Juda-Rezler et al., 2012) [1], while for the point sources the EPS3 model (Emission Processor v.3 from ENVIRON) was implemented in order to obtain vertical distribution of emission. Boundary conditions were acquired from coupling the GEMS (Global and regional Earth-system Monitoring using Satellite and in-situ data) modelling system results with satellite observations. The modelling system has been evaluated for the area of Central-Eastern Europe, regarding ozone and particulate matter (PM) concentrations. For each pollutant measured data from rural background AirBase and EMEP stations, with more than 75% of daily data, has been used. Original 'operational' evaluation methodology, proposed by Juda-Rezler et al. (2012) was applied. Selected set of metrics consists of 5 groups: bias measures, error measures, correlation measures, measures of model variance and spread, which

  16. Observed versus modelled u-, g-, r-, i-, z-band photometry of local galaxies - evaluation of model performance

    NASA Astrophysics Data System (ADS)

    Hansson, K. S. Alexander; Lisker, Thorsten; Grebel, Eva K.

    2012-12-01

    We test how well available stellar population models can reproduce observed u-, g-, r-, i-, z-band photometry of the local galaxy population (0.02 ≤ z ≤ 0.03) as probed by the Sloan Digital Sky Survey (SDSS). Our study is conducted from the perspective of a user of the models, who has observational data in hand and seeks to convert them into physical quantities. Stellar population models for galaxies are created by synthesizing star formation histories and chemical enrichments using single stellar populations from several groups (STARBURST99, GALAXEV, the Maraston models, GALEV). The role of dust is addressed through a simplistic, but observationally motivated, dust model that couples the amplitude of the extinction to the star formation history, metallicity and the viewing angle. Moreover, the influence of emission lines is considered (for the subset of models for which this component is included). The performance of the models is investigated by (1) comparing their prediction with the observed galaxy population in the SDSS using the (u - g)-(r - i) and (g - r)-(i - z) colour planes, (2) comparing predicted stellar mass and luminosity weighted ages and metallicities, specific star formation rates, mass-to-light ratios and total extinctions with literature values from studies based on spectroscopy. Strong differences between the various models are seen with several models occupying regions in the colour-colour diagrams where no galaxies are observed. We would therefore like to emphasize the importance of the choice of model. Using our preferred model we find that the star formation history, metallicity and also dust content can be constrained over a large part of the parameter space through the use of u-, g-, r-, i-, z-band photometry. However, strong local degeneracies are present due to overlap of models with high and low extinction in certain parts of the colour space.

  17. Functional Performance Evaluation

    NASA Technical Reports Server (NTRS)

    Greenisen, Michael C.; Hayes, Judith C.; Siconolfi, Steven F.; Moore, Alan D.

    1999-01-01

    The Extended Duration Orbiter Medical Project (EDOMP) was established to address specific issues associated with optimizing the ability of crews to complete mission tasks deemed essential to entry, landing, and egress for spaceflights lasting up to 16 days. The main objectives of this functional performance evaluation were to investigate the physiological effects of long-duration spaceflight on skeletal muscle strength and endurance, as well as aerobic capacity and orthostatic function. Long-duration exposure to a microgravity environment may produce physiological alterations that affect crew ability to complete critical tasks such as extravehicular activity (EVA), intravehicular activity (IVA), and nominal or emergency egress. Ultimately, this information will be used to develop and verify countermeasures. The answers to three specific functional performance questions were sought: (1) What are the performance decrements resulting from missions of varying durations? (2) What are the physical requirements for successful entry, landing, and emergency egress from the Shuttle? and (3) What combination of preflight fitness training and in-flight countermeasures will minimize in-flight muscle performance decrements? To answer these questions, the Exercise Countermeasures Project looked at physiological changes associated with muscle degradation as well as orthostatic intolerance. A means of ensuring motor coordination was necessary to maintain proficiency in piloting skills, EVA, and IVA tasks. In addition, it was necessary to maintain musculoskeletal strength and function to meet the rigors associated with moderate altitude bailout and with nominal or emergency egress from the landed Orbiter. Eight investigations, referred to as Detailed Supplementary Objectives (DSOs) 475, 476, 477, 606, 608, 617, 618, and 624, were conducted to study muscle degradation and the effects of exercise on exercise capacity and orthostatic function (Table 3-1). This chapter is divided into

  18. ATAMM enhancement and multiprocessor performance evaluation

    NASA Technical Reports Server (NTRS)

    Stoughton, John W.; Mielke, Roland R.; Som, Sukhamoy; Obando, Rodrigo; Malekpour, Mahyar R.; Jones, Robert L., III; Mandala, Brij Mohan V.

    1991-01-01

    ATAMM (Algorithm To Architecture Mapping Model) enhancement and multiprocessor performance evaluation is discussed. The following topics are included: the ATAMM model; ATAMM enhancement; ADM (Advanced Development Model) implementation of ATAMM; and ATAMM support tools.

  19. Performance evaluation of AERMOD, CALPUFF, and legacy air dispersion models using the Winter Validation Tracer Study dataset

    NASA Astrophysics Data System (ADS)

    Rood, Arthur S.

    2014-06-01

    The performance of the steady-state air dispersion models AERMOD and Industrial Source Complex 2 (ISC2), and Lagrangian puff models CALPUFF and RATCHET were evaluated using the Winter Validation Tracer Study dataset. The Winter Validation Tracer Study was performed in February 1991 at the former Rocky Flats Environmental Technology Site near Denver, Colorado. Twelve, 11-h tests were conducted where a conservative tracer was released and measured hourly at 140 samplers in concentric rings 8 km and 16 km from the release point. Performance objectives were unpaired maximum one- and nine-hour average concentration, location of plume maximum, plume impact area, arc-integrated concentration, unpaired nine-hour average concentration, and paired ensemble means. Performance objectives were aimed at addressing regulatory compliance, and dose reconstruction assessment questions. The objective of regulatory compliance is not to underestimate maximum concentrations whereas for dose reconstruction, the objective is an unbiased estimate of concentration in space and time. Performance measures included the fractional bias, normalized mean square error, geometric mean, geometric mean variance, correlation coefficient, and fraction of observations within a factor of two. The Lagrangian puff models tended to exhibit the smallest variance, highest correlation, and highest number of predictions within a factor of two compared to the steady-state models at both the 8-km and 16-km distance. Maximum one- and nine-hour average concentrations were less likely to be under-predicted by the steady-state models compared to the Lagrangian puff models. The characteristic of the steady-state models not to under-predict maximum concentrations make them well suited for regulatory compliance demonstration, whereas the Lagrangian puff models are better suited for dose reconstruction and long range transport.

  20. Using modeling and simulation to evaluate stability and traction performance of a track-laying robotic vehicle

    NASA Astrophysics Data System (ADS)

    Gunter, D. D.; Bylsma, W. W.; Edgar, K.; Letherwood, M. D.; Gorsich, D. J.

    2005-05-01

    DOD has been involved in the research, development and acquisition of unmanned ground vehicle systems to support the troops in the field while minimizing the risks associated with supplying these troops. Engineers and scientists at TARDEC are using computer based modeling and simulation (M&S) to investigate how modifications to unmanned ground vehicles impact their mobility and stability, and to predict performance levels attainable for these types of vehicle systems. The objective of this paper will be to describe the computerbased modeling, simulation, and limited field testing effort that has been undertaken to investigate the dynamic performance of an unmanned tracked vehicle system while conducting a full matrix of tests designed to evaluate system shock, vibration, dynamic stability and off road mobility characteristics. In this paper we will describe the multi-body modeling methodology used as well as the characteristic data incorporated to define the models and their subsystems. The analysis undertaken is applying M&S to baseline the dynamic performance of the vehicle, and comparing these results with performance levels recorded for several manned vehicle systems. We will identify the virtual test matrix over which we executed the models. Finally we will describe our efforts to visualize our findings through the use of computer generated animations of the vehicle system negotiating various virtual automotive tests making up the test matrix.

  1. Validation of alternative models in genetic evaluation of racing performance in North Swedish and Norwegian cold-blooded trotters.

    PubMed

    Olsen, H F; Klemetsdal, G; Odegård, J; Arnason, T

    2012-04-01

    There have been several approaches to the estimation of breeding values of performance in trotters, and the objective of this study was to validate different alternatives for genetic evaluation of racing performance in the North Swedish and Norwegian cold-blooded trotters. The current bivariate approach with the traits racing status (RACE) and earnings (EARN) was compared with a threshold-linear animal model and the univariate alternative with the performance trait only. The models were compared based on cross-validation of standardized earnings, using mean-squared errors of prediction (MSEP) and the correlation between the phenotype (Y) and the estimated breeding value (EBV). Despite possible effects of selection, a rather high estimate of heritability of EARN was found in our univariate analysis. The genetic trend estimate for EARN was clearly higher in the bivariate specification than in the univariate model, as a consequence of the considerable size of estimated heritability of RACE and its high correlation with EARN (approximately 0.8). RACE is highly influenced by ancestry rather than the on-farm performance of the horse itself. Consequently, the use of RACE in the genetic analysis may inflate the genetic trend of EARN because of a double counting of pedigree information. Although, because of the higher predictive ability of the bivariate specification, the improved ranking of animals within a year-class and the inability to discriminate between models for genetic trend, we propose to base prediction of breeding values on the current bivariate model.

  2. Performance evaluation of partial differential equation models in electronic speckle pattern interferometry and the delta-mollification phase map method.

    PubMed

    Tang, Chen; Zhang, Fang; Li, Botao; Yan, Haiqing

    2006-10-01

    The ordinary differential equation (ODE) and partial differential equation (PDE) image- processing methods have been applied to reduce noise and enhance the contrast of electronic speckle pattern interferometry fringe patterns. We evaluate the performance of a few representative PDE denoising models quantitatively with two parameters called image fidelity and speckle index, and then we choose a good denoising model. Combining this denoising model with the ODE enhancement method, we make it possible to perform contrast enhancement and denoising simultaneously. Second, we introduce the delta-mollification method to smooth the unwrapped phase map. Finally, based on PDE image processing, delta mollification and some traditional techniques, an approach of phase extraction from a single fringe pattern is tested for computer-simulated and experimentally obtained fringe patterns. The method works well under a high noise level and limited visibility and can extract accurate phase values.

  3. RLS Instrument Radiometric Model: Instrument performance theoretical evaluation and experimental checks

    NASA Astrophysics Data System (ADS)

    Quintana, César; Ramos, Gonzalo; Moral, Andoni; Rodriguez, Jose Antonio; Pérez, Carlos; Hutchinson, Ian; INGLEY, Richard; Rull, Fernando

    2016-10-01

    Raman Laser Spectrometer (RLS) is one of the Pasteur payload instruments located at the Rover of the ExoMars mission and within the ESA's Aurora Exploration Programme. RLS will explore the Mars surface composition through the Raman spectroscopy technique. The instrument is divided into several units: a laser for Raman emission stimulation, an internal optical head (iOH) for sample excitation and for Raman emission recovering, a spectrometer with a CCD located at its output (SPU), the optical harness (OH) for the units connection, from the laser to the excitation path of the iOH and from the iOH reception path to the spectrometer, and the corresponding electronics for the CCD operation.Due to the variability of the samples to be analyzed on Mars, a radiometry prediction for the instrument performance results to be of the critical importance. In such a framework, and taking into account the SNR (signal to noise ratio) required for the achievement of successful results from the scientific point of view (a proper information about the Mars surface composition), a radiometric model has been developed to provide the requirements for the different units, i.e. the laser irradiance, the iOH, OH, and SPU throughputs, and the samples that will be possible to be analyzed in terms of its Raman emission and the relationship of the Raman signal with respect to fluorescence emission, among others.The radiometric model fundamentals (calculations and approximations), as well as the first results obtained during the bread board characterization campaign are here reported on.

  4. Forest soil carbon stock estimates in a nationwide inventory: evaluating performance of the ROMULv and Yasso07 models in Finland

    NASA Astrophysics Data System (ADS)

    Lehtonen, Aleksi; Linkosalo, Tapio; Peltoniemi, Mikko; Sievänen, Risto; Mäkipää, Raisa; Tamminen, Pekka; Salemaa, Maija; Nieminen, Tiina; Ťupek, Boris; Heikkinen, Juha; Komarov, Alexander

    2016-11-01

    Dynamic soil models are needed for estimating impact of weather and climate change on soil carbon stocks and fluxes. Here, we evaluate performance of Yasso07 and ROMULv models against forest soil carbon stock measurements. More specifically, we ask if litter quantity, litter quality and weather data are sufficient drivers for soil carbon stock estimation. We also test whether inclusion of soil water holding capacity improves reliability of modelled soil carbon stock estimates. Litter input of trees was estimated from stem volume maps provided by the National Forest Inventory, while understorey vegetation was estimated using new biomass models. The litter production rates of trees were based on earlier research, while for understorey biomass they were estimated from measured data. We applied Yasso07 and ROMULv models across Finland and ran those models into steady state; thereafter, measured soil carbon stocks were compared with model estimates. We found that the role of understorey litter input was underestimated when the Yasso07 model was parameterised, especially in northern Finland. We also found that the inclusion of soil water holding capacity in the ROMULv model improved predictions, especially in southern Finland. Our simulations and measurements show that models using only litter quality, litter quantity and weather data underestimate soil carbon stock in southern Finland, and this underestimation is due to omission of the impact of droughts to the decomposition of organic layers. Our results also imply that the ecosystem modelling community and greenhouse gas inventories should improve understorey litter estimation in the northern latitudes.

  5. Methodology to evaluate the performance of simulation models for alternative compiler and operating system configurations

    USDA-ARS?s Scientific Manuscript database

    Simulation modelers increasingly require greater flexibility for model implementation on diverse operating systems, and they demand high computational speed for efficient iterative simulations. Additionally, model users may differ in preference for proprietary versus open-source software environment...

  6. Evaluating the catching performance of aerodynamic rain gauges through field comparisons and CFD modelling

    NASA Astrophysics Data System (ADS)

    Pollock, Michael; Colli, Matteo; Stagnaro, Mattia; Lanza, Luca; Quinn, Paul; Dutton, Mark; O'Donnell, Greg; Wilkinson, Mark; Black, Andrew; O'Connell, Enda

    2016-04-01

    Accurate rainfall measurement is a fundamental requirement in a broad range of applications including flood risk and water resource management. The most widely used method of measuring rainfall is the rain gauge, which is often also considered to be the most accurate. In the context of hydrological modelling, measurements from rain gauges are interpolated to produce an areal representation, which forms an important input to drive hydrological models and calibrate rainfall radars. In each stage of this process another layer of uncertainty is introduced. The initial measurement errors are propagated through the chain, compounding the overall uncertainty. This study looks at the fundamental source of error, in the rainfall measurement itself; and specifically addresses the largest of these, the systematic 'wind-induced' error. Snowfall is outside the scope. The shape of a precipitation gauge significantly affects its collection efficiency (CE), with respect to a reference measurement. This is due to the airflow around the gauge, which causes a deflection in the trajectories of the raindrops near the gauge orifice. Computational Fluid-Dynamic (CFD) simulations are used to evaluate the time-averaged airflows realized around the EML ARG100, EML SBS500 and EML Kalyx-RG rain gauges, when impacted by wind. These gauges have a similar aerodynamic profile - a shape comparable to that of a champagne flute - and they are used globally. The funnel diameter of each gauge, respectively, is 252mm, 254mm and 127mm. The SBS500 is used by the UK Met Office and the Scottish Environmental Protection Agency. Terms of comparison are provided by the results obtained for standard rain gauge shapes manufactured by Casella and OTT which, respectively, have a uniform and a tapered cylindrical shape. The simulations were executed for five different wind speeds; 2, 5, 7, 10 and 18 ms-1. Results indicate that aerodynamic gauges have a different impact on the time-averaged airflow patterns

  7. A quantitative method to evaluate the performance of topographic correction models used to improve land cover identification

    NASA Astrophysics Data System (ADS)

    Park, Sung-Hwan; Jung, Hyung-Sup; Choi, Jaewon; Jeon, Seongwoo

    2017-10-01

    Topographic correction methods have been widely used prior to land cover identification in sloping terrain because the topographic variation on the Earth's surface can interfere with the classifications. The topographic correction involves the normalization of brightness or surface reflectance values from the slanted to the horizontal plane. Several topographic correction models have been proposed, and a quantitative evaluation method is needed for these models because the performance can vary according to the surface cover types and spectral bands. In this study, we proposed an efficient method to evaluate the performance of topographic correction models through measuring the histogram structural similarity (HSSIM) index estimated from the sunlit and sun-shaded slope areas before and after the correction. We tested the HSSIM index by using three different land cover types derived from Landsat-8 Operational Land Imager (OLI) images and eight commonly used topographic correction models. When the proposed HSSIM index was compared with the visual analysis technique, the results matched exactly. Using the HSSIM index, the best correction methods were then determined, and the best ones included the statistical-empirical or SCS+C methods (where SCS+C refers to the sun-canopy-sensor plus C-correction) for the R, G, and B bands and the Minnaert+SCS method for the NIR, SWIR-1, and SWIR-2 bands. These results indicate that (i) the HSSIM index enables quantitative performance evaluations of topographic correction models and (ii) the HSSIM index can be used to determine the best topographic correction method for particular land cover identification applications.

  8. Evaluation of global climate model on performances of precipitation simulation and prediction in the Huaihe River basin

    NASA Astrophysics Data System (ADS)

    Wu, Yenan; Zhong, Ping-an; Xu, Bin; Zhu, Feilin; Fu, Jisi

    2017-06-01

    Using climate models with high performance to predict the future climate changes can increase the reliability of results. In this paper, six kinds of global climate models that selected from the Coupled Model Intercomparison Project Phase 5 (CMIP5) under Representative Concentration Path (RCP) 4.5 scenarios were compared to the measured data during baseline period (1960-2000) and evaluate the simulation performance on precipitation. Since the results of single climate models are often biased and highly uncertain, we examine the back propagation (BP) neural network and arithmetic mean method in assembling the precipitation of multi models. The delta method was used to calibrate the result of single model and multimodel ensembles by arithmetic mean method (MME-AM) during the validation period (2001-2010) and the predicting period (2011-2100). We then use the single models and multimodel ensembles to predict the future precipitation process and spatial distribution. The result shows that BNU-ESM model has the highest simulation effect among all the single models. The multimodel assembled by BP neural network (MME-BP) has a good simulation performance on the annual average precipitation process and the deterministic coefficient during the validation period is 0.814. The simulation capability on spatial distribution of precipitation is: calibrated MME-AM > MME-BP > calibrated BNU-ESM. The future precipitation predicted by all models tends to increase as the time period increases. The order of average increase amplitude of each season is: winter > spring > summer > autumn. These findings can provide useful information for decision makers to make climate-related disaster mitigation plans.

  9. Fit-for-purpose: species distribution model performance depends on evaluation criteria - Dutch Hoverflies as a case study.

    PubMed

    Aguirre-Gutiérrez, Jesús; Carvalheiro, Luísa G; Polce, Chiara; van Loon, E Emiel; Raes, Niels; Reemer, Menno; Biesmeijer, Jacobus C

    2013-01-01

    Understanding species distributions and the factors limiting them is an important topic in ecology and conservation, including in nature reserve selection and predicting climate change impacts. While Species Distribution Models (SDM) are the main tool used for these purposes, choosing the best SDM algorithm is not straightforward as these are plentiful and can be applied in many different ways. SDM are used mainly to gain insight in 1) overall species distributions, 2) their past-present-future probability of occurrence and/or 3) to understand their ecological niche limits (also referred to as ecological niche modelling). The fact that these three aims may require different models and outputs is, however, rarely considered and has not been evaluated consistently. Here we use data from a systematically sampled set of species occurrences to specifically test the performance of Species Distribution Models across several commonly used algorithms. Species range in distribution patterns from rare to common and from local to widespread. We compare overall model fit (representing species distribution), the accuracy of the predictions at multiple spatial scales, and the consistency in selection of environmental correlations all across multiple modelling runs. As expected, the choice of modelling algorithm determines model outcome. However, model quality depends not only on the algorithm, but also on the measure of model fit used and the scale at which it is used. Although model fit was higher for the consensus approach and Maxent, Maxent and GAM models were more consistent in estimating local occurrence, while RF and GBM showed higher consistency in environmental variables selection. Model outcomes diverged more for narrowly distributed species than for widespread species. We suggest that matching study aims with modelling approach is essential in Species Distribution Models, and provide suggestions how to do this for different modelling aims and species' data

  10. The EMEFS model evaluation

    SciTech Connect

    Barchet, W.R. ); Dennis, R.L. ); Seilkop, S.K. ); Banic, C.M.; Davies, D.; Hoff, R.M.; Macdonald, A.M.; Mickle, R.E.; Padro, J.; Puckett, K. ); Byun, D.; McHenry, J.N.

    1991-12-01

    The binational Eulerian Model Evaluation Field Study (EMEFS) consisted of several coordinated data gathering and model evaluation activities. In the EMEFS, data were collected by five air and precipitation monitoring networks between June 1988 and June 1990. Model evaluation is continuing. This interim report summarizes the progress made in the evaluation of the Regional Acid Deposition Model (RADM) and the Acid Deposition and Oxidant Model (ADOM) through the December 1990 completion of a State of Science and Technology report on model evaluation for the National Acid Precipitation Assessment Program (NAPAP). Because various assessment applications of RADM had to be evaluated for NAPAP, the report emphasizes the RADM component of the evaluation. A protocol for the evaluation was developed by the model evaluation team and defined the observed and predicted values to be used and the methods by which the observed and predicted values were to be compared. Scatter plots and time series of predicted and observed values were used to present the comparisons graphically. Difference statistics and correlations were used to quantify model performance. 64 refs., 34 figs., 6 tabs.

  11. Experimental Evaluation of the Performance of the TAP-1 Supercavitating Hydrofoil Model at 80 Knots

    DTIC Science & Technology

    1975-07-01

    8217ODobay, G. F. and N. L. Ficken , "Supercavitating and Ventilated Performance of Three Hydrofoil Sections," NSRDC Report 1828, Jan 1964 53 i~4. q3 Without...34Performance Characteristics of the BuShips Parent Foil," NSROC Report 2084, Aug 1965 1l. Dobay, G. F. and N. L. Ficken , "Supercavitating and Ventilated

  12. Evaluation of Blade-Strike Models for Estimating the Biological Performance of Kaplan Turbines

    SciTech Connect

    Deng, Zhiqun; Carlson, Thomas J.; Ploskey, Gene R.; Richmond, Marshall C.; Dauble, Dennis D.

    2007-11-10

    Bio-indexing of hydroturbines is an important means to optimize passage conditions for fish by identifying operations for existing and new design turbines that minimize the probability of injury. Cost-effective implementation of bio-indexing requires the use of tools such as numerical and physical turbine models to generate hypotheses for turbine operations that can be tested at prototype scales using live fish. Numerical deterministic and stochastic blade strike models were developed for a 1:25-scale physical turbine model built by the U.S. Army Corps of Engineers for the original design turbine at McNary Dam and for prototype-scale original design and replacement minimum gap runner (MGR) turbines at Bonneville Dam's first powerhouse. Blade strike probabilities predicted by both models were comparable with the overall trends in blade strike probability observed in both prototype-scale live fish survival studies and physical turbine model using neutrally buoyant beads. The predictions from the stochastic model were closer to the experimental data than the predictions from the deterministic model because the stochastic model included more realistic consideration of the aspect of fish approaching to the leading edges of turbine runner blades. Therefore, the stochastic model should be the preferred method for the prediction of blade strike and injury probability for juvenile salmon and steelhead using numerical blade-strike models.

  13. Data envelopment analysis model for the appraisal and relative performance evaluation of nurses at an intensive care unit.

    PubMed

    Osman, Ibrahim H; Berbary, Lynn N; Sidani, Yusuf; Al-Ayoubi, Baydaa; Emrouznejad, Ali

    2011-10-01

    The appraisal and relative performance evaluation of nurses are very important and beneficial for both nurses and employers in an era of clinical governance, increased accountability and high standards of health care services. They enhance and consolidate the knowledge and practical skills of nurses by identification of training and career development plans as well as improvement in health care quality services, increase in job satisfaction and use of cost-effective resources. In this paper, a data envelopment analysis (DEA) model is proposed for the appraisal and relative performance evaluation of nurses. The model is validated on thirty-two nurses working at an Intensive Care Unit (ICU) at one of the most recognized hospitals in Lebanon. The DEA was able to classify nurses into efficient and inefficient ones. The set of efficient nurses was used to establish an internal best practice benchmark to project career development plans for improving the performance of other inefficient nurses. The DEA result confirmed the ranking of some nurses and highlighted injustice in other cases that were produced by the currently practiced appraisal system. Further, the DEA model is shown to be an effective talent management and motivational tool as it can provide clear managerial plans related to promoting, training and development activities from the perspective of nurses, hence increasing their satisfaction, motivation and acceptance of appraisal results. Due to such features, the model is currently being considered for implementation at ICU. Finally, the ratio of the number DEA units to the number of input/output measures is revisited with new suggested values on its upper and lower limits depending on the type of DEA models and the desired number of efficient units from a managerial perspective.

  14. Evaluating the performance of the Lee-Carter method and its variants in modelling and forecasting Malaysian mortality

    NASA Astrophysics Data System (ADS)

    Zakiyatussariroh, W. H. Wan; Said, Z. Mohammad; Norazan, M. R.

    2014-12-01

    This study investigated the performance of the Lee-Carter (LC) method and it variants in modeling and forecasting Malaysia mortality. These include the original LC, the Lee-Miller (LM) variant and the Booth-Maindonald-Smith (BMS) variant. These methods were evaluated using Malaysia's mortality data which was measured based on age specific death rates (ASDR) for 1971 to 2009 for overall population while those for 1980-2009 were used in separate models for male and female population. The performance of the variants has been examined in term of the goodness of fit of the models and forecasting accuracy. Comparison was made based on several criteria namely, mean square error (MSE), root mean square error (RMSE), mean absolute deviation (MAD) and mean absolute percentage error (MAPE). The results indicate that BMS method was outperformed in in-sample fitting for overall population and when the models were fitted separately for male and female population. However, in the case of out-sample forecast accuracy, BMS method only best when the data were fitted to overall population. When the data were fitted separately for male and female, LCnone performed better for male population and LM method is good for female population.

  15. Evaluation of the performance of ionospheric models at solar maximum using COSMIC slant TEC measurements

    NASA Astrophysics Data System (ADS)

    Dymond, K. F.; Coker, C.; Metzler, C.; McDonald, S. E.

    2017-03-01

    We report the results of a model validation study that assessed how well several ionospheric models captured the slant total electron content, especially at low latitudes near the equatorial ionization anomaly, where horizontal and vertical density gradients are large. We assessed NeQuick, IRI-2007, IRI-2012, SAMI-3, and the Utah State University version of the Global Assimilation of Ionospheric Measurements (GAIM) model. We used slant total electron content measurements made by the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) constellation during 5 May to 20 June 2012 to test GAIM, NeQuick, IRI-2007, and IRI-2012 and during 1 October 2011 to 31 December 2011 to test SAMI-3, as the SAMI-3 model runs were not available for the 2012 time frame. We found that the GAIM data assimilation model showed the lowest biases, although all of the models typically agreed with the COSMIC measurements to 8% in the worst case. One area of concern with all of the models was that the mean percentage difference between the COSMIC measurements and the calculated total electron content (TEC) showed significant scatter, >15% at the 1 sigma level; this was attributed to all of the models not capturing the density gradients near the equatorial ionization anomaly (EIA). All of the models underestimated the topside electron density and thus also the ionospheric slab thickness. Since ionospheric models are often validated using near-vertical TEC measurements and the vertical TEC is the product of the electron density at the F region peak and the slab thickness, our results suggest that the peak density values in the models may be too high.

  16. GROUND-WATER MODEL TESTING: SYSTEMATIC EVALUATION AND TESTING OF CODE FUNCTIONALITY AND PERFORMANCE

    EPA Science Inventory

    Effective use of ground-water simulation codes as management decision tools requires the establishment of their functionality, performance characteristics, and applicability to the problem at hand. This is accomplished through application of a systematic code-testing protocol and...

  17. GROUND-WATER MODEL TESTING: SYSTEMATIC EVALUATION AND TESTING OF CODE FUNCTIONALITY AND PERFORMANCE

    EPA Science Inventory

    Effective use of ground-water simulation codes as management decision tools requires the establishment of their functionality, performance characteristics, and applicability to the problem at hand. This is accomplished through application of a systematic code-testing protocol and...

  18. Maritime Platform Sleep and Performance Study: Evaluating the SAFTE Model for Maritime Workplace Application

    DTIC Science & Technology

    2012-06-01

    the t statistic (t), p-values (p), and sample correlations (r) ...........29  Table 3.  Actigraphy determined sleep metrics by ship status (blocked on...crew performance levels with the predicted performance based on sleep obtained as measure through actigraphy , I analyze the accuracy of current...moderate sleep restrictions can change sleep architecture and seriously impair waking neurobehavioral functions in healthy adults (Van Dongen et al., 2003

  19. Evaluating the performance of a glacier erosion model applied to Peyto Glacier, Alberta, Canada

    NASA Astrophysics Data System (ADS)

    Vogt, R.; Mlynowski, T. J.; Menounos, B.

    2013-12-01

    Glaciers are effective agents of erosion for many mountainous regions, but primary rates of erosion are difficult to quantify due to unknown conditions at the glacier bed. We develop a numerical model of subglacial erosion and passively couple it to a vertically integrated ice flow model (UBC regional glaciation model). The model accounts for seasonal changes in water pressure at the glacier bed which affect rates of abrasion and quarrying. We apply our erosion model to Peyto Glacier, and compare estimates of glacier erosion to the mass of fine sediment contained in a lake immediately down valley from the glacier. A series of experiments with our model and ones based on subglacial sliding rates are run to explore model sensitivity to bedrock hardness, seasonal hydrology, changes in mass balance, and longer-term dimensional changes of the glacier. Our experiments show that, as expected, erosion rates are most sensitive to bedrock hardness and changes in glacier mass balance. Silt and clay contained in Peyto Lake primarily originate from the glacier, and represent sediments derived from abrasion and comminution of material produced by quarrying. Average specific sediment yield during the period AD1917-1970 from the lake is 467×190 Mg km-2yr-1 and reaches a maximum of 928 Mg km-2yr-1 in AD1941. Converting to a specific sediment yield, modelled average abrasion and quarrying rates during the comparative period are 142×44 Mg km-2yr-1 and 1167×213 Mg km-2yr-1 respectively. Modelled quarrying accounts for approximately 85-95% of the erosion occurring beneath the glacier. The basal sliding model estimates combined abrasion and quarrying. During the comparative period, estimated yields average 427×136 Mg km-2yr-1, lower than the combined abrasion and quarrying models. Both models predict maximum sediment yield when Peyto Glacier reached its maximum extent. The simplistic erosion model shows higher sensitivity to climate, as seen by accentuated sediment yield peaks

  20. Algorithm performance evaluation

    NASA Astrophysics Data System (ADS)

    Smith, Richard N.; Greci, Anthony M.; Bradley, Philip A.

    1995-03-01

    Traditionally, the performance of adaptive antenna systems is measured using automated antenna array pattern measuring equipment. This measurement equipment produces a plot of the receive gain of the antenna array as a function of angle. However, communications system users more readily accept and understand bit error rate (BER) as a performance measure. The work reported on here was conducted to characterize adaptive antenna receiver performance in terms of overall communications system performance using BER as a performance measure. The adaptive antenna system selected for this work featured a linear array, least mean square (LMS) adaptive algorithm and a high speed phase shift keyed (PSK) communications modem.

  1. A Fast All-sky Radiation Model for Solar applications (FARMS): Algorithm and performance evaluation

    SciTech Connect

    Xie, Yu; Sengupta, Manajit; Dudhia, Jimy

    2016-10-01

    Radiative transfer (RT) models simulating broadband solar radiation have been widely used by atmospheric scientists to model solar resources for various energy applications such as operational forecasting. Due to the complexity of solving the RT equation, the computation under cloudy conditions can be extremely time-consuming, though many approximations (e.g., two-stream approach and delta-M truncation scheme) have been utilized. Thus, a more efficient RT model is crucial for model developers as a new option for approximating solar radiation at the land surface with minimal loss of accuracy. In this study, we developed a fast all-sky radiation model for solar applications (FARMS) using the simplified clear-sky RT model, REST2, and simulated cloud transmittances and reflectances from the Rapid Radiation Transfer Model (RRTM) with a 16-stream Discrete Ordinates Radiative Transfer (DISORT). Simulated lookup tables (LUTs) of cloud transmittances and reflectances are created by varying cloud optical thicknesses, cloud particle sizes, and solar zenith angles. Equations with optimized parameters are fitted to the cloud transmittances and reflectances to develop the model. The all-sky solar irradiance at the land surface can then be computed rapidly by combining REST2 with the cloud transmittances and reflectances. This new RT model is more than 1,000 times faster than those currently utilized in solar resource assessment and forecasting because it does not explicitly solve the RT equation for each individual cloud condition. Our results indicate that the accuracy of the fast radiative transfer model is comparable to or better than two-stream approximation in term of computing cloud transmittance and solar radiation.

  2. An evaluation of 1D loss model collections for the off-design performance prediction of automotive turbocharger compressors

    NASA Astrophysics Data System (ADS)

    Harley, P.; Spence, S.; Early, J.; Filsinger, D.; Dietrich, M.

    2013-12-01

    Single-zone modelling is used to assess different collections of impeller 1D loss models. Three collections of loss models have been identified in literature, and the background to each of these collections is discussed. Each collection is evaluated using three modern automotive turbocharger style centrifugal compressors; comparisons of performance for each of the collections are made. An empirical data set taken from standard hot gas stand tests for each turbocharger is used as a baseline for comparison. Compressor range is predicted in this study; impeller diffusion ratio is shown to be a useful method of predicting compressor surge in 1D, and choke is predicted using basic compressible flow theory. The compressor designer can use this as a guide to identify the most compatible collection of losses for turbocharger compressor design applications. The analysis indicates the most appropriate collection for the design of automotive turbocharger centrifugal compressors.

  3. BPACK -- A computer model package for boiler reburning/co-firing performance evaluations. User`s manual, Volume 1

    SciTech Connect

    Wu, K.T.; Li, B.; Payne, R.

    1992-06-01

    This manual presents and describes a package of computer models uniquely developed for boiler thermal performance and emissions evaluations by the Energy and Environmental Research Corporation. The model package permits boiler heat transfer, fuels combustion, and pollutant emissions predictions related to a number of practical boiler operations such as fuel-switching, fuels co-firing, and reburning NO{sub x} reductions. The models are adaptable to most boiler/combustor designs and can handle burner fuels in solid, liquid, gaseous, and slurried forms. The models are also capable of performing predictions for combustion applications involving gaseous-fuel reburning, and co-firing of solid/gas, liquid/gas, gas/gas, slurry/gas fuels. The model package is conveniently named as BPACK (Boiler Package) and consists of six computer codes, of which three of them are main computational codes and the other three are input codes. The three main codes are: (a) a two-dimensional furnace heat-transfer and combustion code: (b) a detailed chemical-kinetics code; and (c) a boiler convective passage code. This user`s manual presents the computer model package in two volumes. Volume 1 describes in detail a number of topics which are of general users` interest, including the physical and chemical basis of the models, a complete description of the model applicability, options, input/output, and the default inputs. Volume 2 contains a detailed record of the worked examples to assist users in applying the models, and to illustrate the versatility of the codes.

  4. Evaluation models and evaluation use

    PubMed Central

    Contandriopoulos, Damien; Brousselle, Astrid

    2012-01-01

    The use of evaluation results is at the core of evaluation theory and practice. Major debates in the field have emphasized the importance of both the evaluator’s role and the evaluation process itself in fostering evaluation use. A recent systematic review of interventions aimed at influencing policy-making or organizational behavior through knowledge exchange offers a new perspective on evaluation use. We propose here a framework for better understanding the embedded relations between evaluation context, choice of an evaluation model and use of results. The article argues that the evaluation context presents conditions that affect both the appropriateness of the evaluation model implemented and the use of results. PMID:23526460

  5. Application of Lidar Data to the Performance Evaluations of CMAQ Model

    EPA Science Inventory

    The Tropospheric Ozone (O3) Lidar Network (TOLNet) provides time/height O3 measurements from near the surface to the top of the troposphere to describe in high-fidelity spatial-temporal distributions, which is uniquely useful to evaluate the temporal evolution of O3 profiles in a...

  6. Application of Lidar Data to the Performance Evaluations of CMAQ Model

    EPA Science Inventory

    The Tropospheric Ozone (O3) Lidar Network (TOLNet) provides time/height O3 measurements from near the surface to the top of the troposphere to describe in high-fidelity spatial-temporal distributions, which is uniquely useful to evaluate the temporal evolution of O3 profiles in a...

  7. Surface characteristics modeling and performance evaluation of urban building materials using LiDAR data.

    PubMed

    Li, Xiaolu; Liang, Yu

    2015-05-20

    Analysis of light detection and ranging (LiDAR) intensity data to extract surface features is of great interest in remote sensing research. One potential application of LiDAR intensity data is target classification. A new bidirectional reflectance distribution function (BRDF) model is derived for target characterization of rough and smooth surfaces. Based on the geometry of our coaxial full-waveform LiDAR system, the integration method is improved through coordinate transformation to establish the relationship between the BRDF model and intensity data of LiDAR. A series of experiments using typical urban building materials are implemented to validate the proposed BRDF model and integration method. The fitting results show that three parameters extracted from the proposed BRDF model can distinguish the urban building materials from perspectives of roughness, specular reflectance, and diffuse reflectance. A comprehensive analysis of these parameters will help characterize surface features in a physically rigorous manner.

  8. Performance evaluation of dual-frequency driving plate ultrasonic motor based on an analytical model.

    PubMed

    Pang, Yafei; Yang, Ming; Chen, Xuying; He, Wei; Li, Shiyang; Li, Chaodong

    2011-08-01

    An analytical model is presented to explain the effects of dual-frequency drive on the plate ultrasonic motor in this paper. The experimental prototype is a plate ultrasonic motor using single-phase asymmetric excitation, which can work under a single vibration or multiple vibration modes. Based on the linear superposition of vibrations with two different excitation frequencies, an analytical model is established using the classic Coulomb friction model, and the non-load rotation speed and maximum stall torque are deduced. Moreover, some crucial parameters such as preload and dead-zone in dual-frequency superposition model are identified or modified automatically by searching for the maximum correlation coefficient between simulation and experimental data using single-frequency drive. It is found that simulation and experiment results agree well when no excitation frequency component is at resonance.

  9. Distributed Space Mission Design for Earth Observation Using Model-Based Performance Evaluation

    NASA Technical Reports Server (NTRS)

    Nag, Sreeja; LeMoigne-Stewart, Jacqueline; Cervantes, Ben; DeWeck, Oliver

    2015-01-01

    Distributed Space Missions (DSMs) are gaining momentum in their application to earth observation missions owing to their unique ability to increase observation sampling in multiple dimensions. DSM design is a complex problem with many design variables, multiple objectives determining performance and cost and emergent, often unexpected, behaviors. There are very few open-access tools available to explore the tradespace of variables, minimize cost and maximize performance for pre-defined science goals, and therefore select the most optimal design. This paper presents a software tool that can multiple DSM architectures based on pre-defined design variable ranges and size those architectures in terms of predefined science and cost metrics. The tool will help a user select Pareto optimal DSM designs based on design of experiments techniques. The tool will be applied to some earth observation examples to demonstrate its applicability in making some key decisions between different performance metrics and cost metrics early in the design lifecycle.

  10. Artificial intelligence modeling to evaluate field performance of photocatalytic asphalt pavement for ambient air purification.

    PubMed

    Asadi, Somayeh; Hassan, Marwa; Nadiri, Ataallah; Dylla, Heather

    2014-01-01

    In recent years, the application of titanium dioxide (TiO₂) as a photocatalyst in asphalt pavement has received considerable attention for purifying ambient air from traffic-emitted pollutants via photocatalytic processes. In order to control the increasing deterioration of ambient air quality, urgent and proper risk assessment tools are deemed necessary. However, in practice, monitoring all process parameters for various operating conditions is difficult due to the complex and non-linear nature of air pollution-based problems. Therefore, the development of models to predict air pollutant concentrations is very useful because it can provide early warnings to the population and also reduce the number of measuring sites. This study used artificial neural network (ANN) and neuro-fuzzy (NF) models to predict NOx concentration in the air as a function of traffic count (Tr) and climatic conditions including humidity (H), temperature (T), solar radiation (S), and wind speed (W) before and after the application of TiO₂ on the pavement surface. These models are useful for modeling because of their ability to be trained using historical data and because of their capability for modeling highly non-linear relationships. To build these models, data were collected from a field study where an aqueous nano TiO₂ solution was sprayed on a 0.2-mile of asphalt pavement in Baton Rouge, LA. Results of this study showed that the NF model provided a better fitting to NOx measurements than the ANN model in the training, validation, and test steps. Results of a parametric study indicated that traffic level, relative humidity, and solar radiation had the most influence on photocatalytic efficiency.

  11. THE ATMOSPHERIC MODEL EVALUATION TOOL

    EPA Science Inventory

    This poster describes a model evaluation tool that is currently being developed and applied for meteorological and air quality model evaluation. The poster outlines the framework and provides examples of statistical evaluations that can be performed with the model evaluation tool...

  12. THE ATMOSPHERIC MODEL EVALUATION TOOL

    EPA Science Inventory

    This poster describes a model evaluation tool that is currently being developed and applied for meteorological and air quality model evaluation. The poster outlines the framework and provides examples of statistical evaluations that can be performed with the model evaluation tool...

  13. Vender Performance Evaluation.

    ERIC Educational Resources Information Center

    Grant, Joan; Perelmuter, Susan

    1978-01-01

    Vendor selection can mean success or failure of an approval plan; this study evaluates three book vendors by comparing their plans on the bases of speed, bibliographic accuracy, and discounts. (Author/CWM)

  14. Performance evaluation and channel modeling of MIMO free space optical communication system

    NASA Astrophysics Data System (ADS)

    Deng, Tianping; Lu, Yimin; Lu, Gang; Peng, Kai

    2005-11-01

    Free space optical communication systems represent one of the most promising approaches for addressing the emerging broadband access market, it can provide high bandwidth with no physical contact, but are hampered by signal fading effects due to particulate scattering caused by atmospheric turbulence. In this paper, we propose a new channel model of MIMO free space optical communication system. The physics meaning of this model is very clear, and its format is very simple. Mathematic results show that MIMO is a very effective way for intensity fluctuation reduction induced by turbulence, thus reduce the bit-error-rate of the system.

  15. OBJECTIVE REDUCTION OF THE SPACE-TIME DOMAIN DIMENSIONALITY FOR EVALUATING MODEL PERFORMANCE

    EPA Science Inventory

    In the United States, photochemical air quality models are the principal tools used by governmental agencies to develop emission reduction strategies aimed at achieving National Ambient Air Quality Standards (NAAQS). Before they can be applied with confidence in a regulatory sett...

  16. Evaluation of the Logistic Model for GAC Performance in Water Treatment

    EPA Science Inventory

    Full-scale field measurement and rapid small-scale column test data from the Greater Cincinnati (Ohio) Water Works (GCWW) were used to calibrate and investigate the application of the logistic model for simulating breakthrough of total organic carbon (TOC) in granular activated c...

  17. OBJECTIVE REDUCTION OF THE SPACE-TIME DOMAIN DIMENSIONALITY FOR EVALUATING MODEL PERFORMANCE

    EPA Science Inventory

    In the United States, photochemical air quality models are the principal tools used by governmental agencies to develop emission reduction strategies aimed at achieving National Ambient Air Quality Standards (NAAQS). Before they can be applied with confidence in a regulatory sett...

  18. Evaluation of the Logistic Model for GAC Performance in Water Treatment

    EPA Science Inventory

    Full-scale field measurement and rapid small-scale column test data from the Greater Cincinnati (Ohio) Water Works (GCWW) were used to calibrate and investigate the application of the logistic model for simulating breakthrough of total organic carbon (TOC) in granular activated c...

  19. Development and Evaluation of a Performance Modeling Flight Test Approach Based on Quasi Steady-State Maneuvers

    NASA Technical Reports Server (NTRS)

    Yechout, T. R.; Braman, K. B.

    1984-01-01

    The development, implementation and flight test evaluation of a performance modeling technique which required a limited amount of quasisteady state flight test data to predict the overall one g performance characteristics of an aircraft. The concept definition phase of the program include development of: (1) the relationship for defining aerodynamic characteristics from quasi steady state maneuvers; (2) a simplified in flight thrust and airflow prediction technique; (3) a flight test maneuvering sequence which efficiently provided definition of baseline aerodynamic and engine characteristics including power effects on lift and drag; and (4) the algorithms necessary for cruise and flight trajectory predictions. Implementation of the concept include design of the overall flight test data flow, definition of instrumentation system and ground test requirements, development and verification of all applicable software and consolidation of the overall requirements in a flight test plan.

  20. Validating Human Behavioral Models for Combat Simulations Using Techniques for the Evaluation of Human Performance

    DTIC Science & Technology

    2004-01-01

    Bayesian-Network, Neural-Network, Agent-Based, and Multi - Agent System . ISBN: 1-56555-268-7 739 SCSC 󈧇 Rule-Based A rule-based or...situational awareness based on their previous knowledge of the world and current sensory inputs. [11] ISBN: 1-56555-268-7 740 SCSC 󈧇 Multi - Agent System (MAS...A multi - agent system (MAS) is a behavior model representation with autonomous or semi- autonomous software agents that produce

  1. Man vs. Machine: An interactive poll to evaluate hydrological model performance of a manual and an automatic calibration

    NASA Astrophysics Data System (ADS)

    Wesemann, Johannes; Burgholzer, Reinhard; Herrnegger, Mathew; Schulz, Karsten

    2017-04-01

    In recent years, a lot of research in hydrological modelling has been invested to improve the automatic calibration of rainfall-runoff models. This includes for example (1) the implementation of new optimisation methods, (2) the incorporation of new and different objective criteria and signatures in the optimisation and (3) the usage of auxiliary data sets apart from runoff. Nevertheless, in many applications manual calibration is still justifiable and frequently applied. The hydrologist performing the manual calibration, with his expert knowledge, is able to judge the hydrographs simultaneously concerning details but also in a holistic view. This integrated eye-ball verification procedure available to man can be difficult to formulate in objective criteria, even when using a multi-criteria approach. Comparing the results of automatic and manual calibration is not straightforward. Automatic calibration often solely involves objective criteria such as Nash-Sutcliffe Efficiency Coefficient or the Kling-Gupta-Efficiency as a benchmark during the calibration. Consequently, a comparison based on such measures is intrinsically biased towards automatic calibration. Additionally, objective criteria do not cover all aspects of a hydrograph leaving questions concerning the quality of a simulation open. This contribution therefore seeks to examine the quality of manually and automatically calibrated hydrographs by interactively involving expert knowledge in the evaluation. Simulations have been performed for the Mur catchment in Austria with the rainfall-runoff model COSERO using two parameter sets evolved from a manual and an automatic calibration. A subset of resulting hydrographs for observation and simulation, representing the typical flow conditions and events, will be evaluated in this study. In an interactive crowdsourcing approach experts attending the session can vote for their preferred simulated hydrograph without having information on the calibration method that

  2. Evaluating Health Risk Models

    PubMed Central

    2010-01-01

    SUMMARY Interest in targeted disease prevention has stimulated development of models that assign risks to individuals, using their personal covariates. We need to evaluate these models and quantify the gains achieved by expanding a model to include additional covariates. This paper reviews several performance measures and shows how they are related. Examples are used to show that appropriate performance criteria for a risk model depend upon how the model is used. Application of the performance measures to risk models for hypothetical populations and for US women at risk of breast cancer illustrate two additional points. First, model performance is constrained by the distribution of risk-determining covariates in the population. This complicates the comparison of two models when applied to populations with different covariate distributions. Second, all summary performance measures obscure model features of relevance to its utility for the application at hand, such as performance in specific subgroups of the population. In particular, the precision gained by adding covariates to a model can be small overall, but large in certain subgroups. We propose new ways to identify these subgroups and to quantify how much they gain by measuring the additional covariates. Those with largest gains could be targeted for cost-efficient covariate assessment. PMID:20623821

  3. Proposal for a Conceptual Model for Evaluating Lean Product Development Performance: A Study of LPD Enablers in Manufacturing Companies

    NASA Astrophysics Data System (ADS)

    Osezua Aikhuele, Daniel; Mohd Turan, Faiz

    2016-02-01

    The instability in today's market and the emerging demands for mass customized products by customers, are driving companies to seek for cost effective and time efficient improvements in their production system and this have led to real pressure for the adaptation of new developmental architecture and operational parameters to remain competitive in the market. Among such developmental architecture adopted, is the integration of lean thinking in the product development process. However, due to lack of clear understanding of the lean performance and its measurements, many companies are unable to implement and fully integrate the lean principle into their product development process and without a proper performance measurement, the performance level of the organizational value stream will be unknown and the specific area of improvement as it relates to the LPD program cannot be tracked. Hence, it will result in poor decision making in the LPD implementation. This paper therefore seeks to present a conceptual model for evaluation of LPD performances by identifying and analysing the core existing LPD enabler (Chief Engineer, Cross-functional teams, Set-based engineering, Poka-yoke (mistakeproofing), Knowledge-based environment, Value-focused planning and development, Top management support, Technology, Supplier integration, Workforce commitment and Continuous improvement culture) for assessing the LPD performance.

  4. Rank and Order: Evaluating the Performance of SNPs for Individual Assignment in a Non-Model Organism

    PubMed Central

    Storer, Caroline G.; Pascal, Carita E.; Roberts, Steven B.; Templin, William D.; Seeb, Lisa W.; Seeb, James E.

    2012-01-01

    Single nucleotide polymorphisms (SNPs) are valuable tools for ecological and evolutionary studies. In non-model species, the use of SNPs has been limited by the number of markers available. However, new technologies and decreasing technology costs have facilitated the discovery of a constantly increasing number of SNPs. With hundreds or thousands of SNPs potentially available, there is interest in comparing and developing methods for evaluating SNPs to create panels of high-throughput assays that are customized for performance, research questions, and resources. Here we use five different methods to rank 43 new SNPs and 71 previously published SNPs for sockeye salmon: FST, informativeness (In), average contribution to principal components (LC), and the locus-ranking programs BELS and WHICHLOCI. We then tested the performance of these different ranking methods by creating 48- and 96-SNP panels of the top-ranked loci for each method and used empirical and simulated data to obtain the probability of assigning individuals to the correct population using each panel. All 96-SNP panels performed similarly and better than the 48-SNP panels except for the 96-SNP BELS panel. Among the 48-SNP panels, panels created from FST, In, and LC ranks performed better than panels formed using the top-ranked loci from the programs BELS and WHICHLOCI. The application of ranking methods to optimize panel performance will become more important as more high-throughput assays become available. PMID:23185290

  5. Rank and order: evaluating the performance of SNPs for individual assignment in a non-model organism.

    PubMed

    Storer, Caroline G; Pascal, Carita E; Roberts, Steven B; Templin, William D; Seeb, Lisa W; Seeb, James E

    2012-01-01

    Single nucleotide polymorphisms (SNPs) are valuable tools for ecological and evolutionary studies. In non-model species, the use of SNPs has been limited by the number of markers available. However, new technologies and decreasing technology costs have facilitated the discovery of a constantly increasing number of SNPs. With hundreds or thousands of SNPs potentially available, there is interest in comparing and developing methods for evaluating SNPs to create panels of high-throughput assays that are customized for performance, research questions, and resources. Here we use five different methods to rank 43 new SNPs and 71 previously published SNPs for sockeye salmon: F(ST), informativeness (I(n)), average contribution to principal components (LC), and the locus-ranking programs BELS and WHICHLOCI. We then tested the performance of these different ranking methods by creating 48- and 96-SNP panels of the top-ranked loci for each method and used empirical and simulated data to obtain the probability of assigning individuals to the correct population using each panel. All 96-SNP panels performed similarly and better than the 48-SNP panels except for the 96-SNP BELS panel. Among the 48-SNP panels, panels created from F(ST), I(n), and LC ranks performed better than panels formed using the top-ranked loci from the programs BELS and WHICHLOCI. The application of ranking methods to optimize panel performance will become more important as more high-throughput assays become available.

  6. IR DIAL performance modeling

    SciTech Connect

    Sharlemann, E.T.

    1994-07-01

    We are developing a DIAL performance model for CALIOPE at LLNL. The intent of the model is to provide quick and interactive parameter sensitivity calculations with immediate graphical output. A brief overview of the features of the performance model is given, along with an example of performance calculations for a non-CALIOPE application.

  7. Evaluation of Vessel Sealing Performance Among Ultrasonic Devices in a Porcine Model.

    PubMed

    Tanaka, Ryota; Gitelis, Matthew; Meiselman, Danny; Abar, Bijan; Zapf, Matthew; Carbray, JoAnn; Vigneswaran, Yalini; Zhao, Jin-Cheng; Ujiki, Michael

    2015-08-01

    As new technologies emerge, it is imperative to define which new devices are most likely to provide a reproducible, effective result for the patient and surgeon. The purpose of our study was to analyze 3 commercially available ultrasonic energy devices; the Sonicision (SC), the Harmonic ACE (HA), and the THUNDERBEAT (TB). Eight female Yorkshire pigs were used for data collection and vessel harvest. Three devices were evaluated and compared with each other with respect to seal failure and cutting speed in vivo. After vessel harvest, one end of the fragment was sent for histological evaluation, and the other was used for burst pressure measurement testing in a blinded fashion. The coagulation and cut levels of all the generators were set up at a similar and constant level. Eighty-four vessels (47 arteries and 37 veins) were tested. Mean vessel diameter was equal among the groups. Cutting speed was significantly faster with TB (3.4 ± 0.7 seconds) than SC or HA (5.8 ± 2.4 and 6.1 ± 3.1 seconds; P < .0001). Burst pressure trended higher after ligation with TB (505.4 ± 349.4 mm Hg) than SC and HA (435.8 ± 403.0 and 437.6 ± 291.3 mm Hg). There were 2 seal failures in the SC group and HA group and none in the TB group. Histologically, the perpendicular width of tissue seal with TB (1.250 ± 0.55 mm) was significantly longer than that of the SC and the HA (0.772 ± 0.23 and 0.686 ± 0.23 mm; P < .0001). TB has proven to provide the most rapid and reliable seal. Therefore, TB may be safer and may decrease time during surgical procedures. © The Author(s) 2015.

  8. Performance evaluation of Maxwell and Cercignani-Lampis gas-wall interaction models in the modeling of thermally driven rarefied gas transport

    NASA Astrophysics Data System (ADS)

    Liang, Tengfei; Li, Qi; Ye, Wenjing

    2013-07-01

    A systematic study on the performance of two empirical gas-wall interaction models, the Maxwell model and the Cercignani-Lampis (CL) model, in the entire Knudsen range is conducted. The models are evaluated by examining the accuracy of key macroscopic quantities such as temperature, density, and pressure, in three benchmark thermal problems, namely the Fourier thermal problem, the Knudsen force problem, and the thermal transpiration problem. The reference solutions are obtained from a validated hybrid DSMC-MD algorithm developed in-house. It has been found that while both models predict temperature and density reasonably well in the Fourier thermal problem, the pressure profile obtained from Maxwell model exhibits a trend that opposes that from the reference solution. As a consequence, the Maxwell model is unable to predict the orientation change of the Knudsen force acting on a cold cylinder embedded in a hot cylindrical enclosure at a certain Knudsen number. In the simulation of the thermal transpiration coefficient, although all three models overestimate the coefficient, the coefficient obtained from CL model is the closest to the reference solution. The Maxwell model performs the worst. The cause of the overestimated coefficient is investigated and its link to the overly constrained correlation between the tangential momentum accommodation coefficient and the tangential energy accommodation coefficient inherent in the models is pointed out. Directions for further improvement of models are suggested.

  9. Performance evaluation of a web-based system to exchange Electronic Health Records using Queueing model (M/M/1).

    PubMed

    de la Torre, Isabel; Díaz, Francisco Javier; Antón, Míriam; Martínez, Mario; Díez, José Fernando; Boto, Daniel; López, Miguel; Hornero, Roberto; López, María Isabel

    2012-04-01

    Response time measurement of a web-based system is essential to evaluate its performance. This paper shows a comparison of the response times of a Web-based system for Ophthalmologic Electronic Health Records (EHRs), TeleOftalWeb. It makes use of different database models like Oracle 10 g, dbXML 2.0, Xindice 1.2, and eXist 1.1.1. The system's modelling, which uses Tandem Queue networks, will allow us to estimate the service times of the different components of the system (CPU, network and databases). In order to calculate those times, associated to the different databases, benchmarking techniques are used. The final objective of the comparison is to choose the database system resulting in the lowest response time to TeleOftalWeb and to compare the obtained results using a new benchmarking.

  10. Instrument performance evaluation

    SciTech Connect

    Swinth, K.L.

    1993-03-01

    Deficiencies exist in both the performance and the quality of health physics instruments. Recognizing the implications of such deficiencies for the protection of workers and the public, in the early 1980s the DOE and the NRC encouraged the development of a performance standard and established a program to test a series of instruments against criteria in the standard. The purpose of the testing was to establish the practicality of the criteria in the standard, to determine the performance of a cross section of available instruments, and to establish a testing capability. Over 100 instruments were tested, resulting in a practical standard and an understanding of the deficiencies in available instruments. In parallel with the instrument testing, a value-impact study clearly established the benefits of implementing a formal testing program. An ad hoc committee also met several times to establish recommendations for the voluntary implementation of a testing program based on the studies and the performance standard. For several reasons, a formal program did not materialize. Ongoing tests and studies have supported the development of specific instruments and have helped specific clients understand the performance of their instruments. The purpose of this presentation is to trace the history of instrument testing to date and suggest the benefits of a centralized formal program.

  11. Combustion modeling and performance evaluation in a full-scale rotary kiln incinerator.

    PubMed

    Chen, K S; Hsu, W T; Lin, Y C; Ho, Y T; Wu, C H

    2001-06-01

    This work summarizes the results of numerical investigations and in situ measurements for turbulent combustion in a full-scale rotary kiln incinerator (RKI). The three-dimensional (3D) governing equations for mass, momentum, energy, and species, together with the kappa - epsilon turbulence model, are formulated and solved using a finite volume method. Volatile gases from solid waste were simulated by gaseous CH4 distributed nonuniformly along the kiln bed. The combustion process was considered to be a two-step stoichiometric reaction for primary air mixed with CH4 gas in the combustion chamber. The mixing-controlled eddy-dissipation model (EDM) was employed to predict the conversion rates of CH4, O2, CO2, and CO. The results of the prediction show that reverse flows occur near the entrance of the first combustion chamber (FCC) and the turning point at the entrance to the second combustion chamber (SCC). Temperature and species are nonuniform and are vertically stratified. Meanwhile, additional mixing in the SCC enhances postflame oxidation. A combustion efficiency of up to 99.96% can be achieved at approximately 150% excess air and 20-30% secondary air. Reasonable agreement is achieved between numerical predictions and in situ measurements.

  12. Evaluating the Performance of a Climate-Driven Mortality Model during Heat Waves and Cold Spells in Europe

    PubMed Central

    Lowe, Rachel; Ballester, Joan; Creswick, James; Robine, Jean-Marie; Herrmann, François R.; Rodó, Xavier

    2015-01-01

    The impact of climate change on human health is a serious concern. In particular, changes in the frequency and intensity of heat waves and cold spells are of high relevance in terms of mortality and morbidity. This demonstrates the urgent need for reliable early-warning systems to help authorities prepare and respond to emergency situations. In this study, we evaluate the performance of a climate-driven mortality model to provide probabilistic predictions of exceeding emergency mortality thresholds for heat wave and cold spell scenarios. Daily mortality data corresponding to 187 NUTS2 regions across 16 countries in Europe were obtained from 1998–2003. Data were aggregated to 54 larger regions in Europe, defined according to similarities in population structure and climate. Location-specific average mortality rates, at given temperature intervals over the time period, were modelled to account for the increased mortality observed during both high and low temperature extremes and differing comfort temperatures between regions. Model parameters were estimated in a Bayesian framework, in order to generate probabilistic simulations of mortality across Europe for time periods of interest. For the heat wave scenario (1–15 August 2003), the model was successfully able to anticipate the occurrence or non-occurrence of mortality rates exceeding the emergency threshold (75th percentile of the mortality distribution) for 89% of the 54 regions, given a probability decision threshold of 70%. For the cold spell scenario (1–15 January 2003), mortality events in 69% of the regions were correctly anticipated with a probability decision threshold of 70%. By using a more conservative decision threshold of 30%, this proportion increased to 87%. Overall, the model performed better for the heat wave scenario. By replacing observed temperature data in the model with forecast temperature, from state-of-the-art European forecasting systems, probabilistic mortality predictions could

  13. Evaluating the performance of a climate-driven mortality model during heat waves and cold spells in Europe.

    PubMed

    Lowe, Rachel; Ballester, Joan; Creswick, James; Robine, Jean-Marie; Herrmann, François R; Rodó, Xavier

    2015-01-23

    The impact of climate change on human health is a serious concern. In particular, changes in the frequency and intensity of heat waves and cold spells are of high relevance in terms of mortality and morbidity. This demonstrates the urgent need for reliable early-warning systems to help authorities prepare and respond to emergency situations. In this study, we evaluate the performance of a climate-driven mortality model to provide probabilistic predictions of exceeding emergency mortality thresholds for heat wave and cold spell scenarios. Daily mortality data corresponding to 187 NUTS2 regions across 16 countries in Europe were obtained from 1998-2003. Data were aggregated to 54 larger regions in Europe, defined according to similarities in population structure and climate. Location-specific average mortality rates, at given temperature intervals over the time period, were modelled to account for the increased mortality observed during both high and low temperature extremes and differing comfort temperatures between regions. Model parameters were estimated in a Bayesian framework, in order to generate probabilistic simulations of mortality across Europe for time periods of interest. For the heat wave scenario (1-15 August 2003), the model was successfully able to anticipate the occurrence or non-occurrence of mortality rates exceeding the emergency threshold (75th percentile of the mortality distribution) for 89% of the 54 regions, given a probability decision threshold of 70%. For the cold spell scenario (1-15 January 2003), mortality events in 69% of the regions were correctly anticipated with a probability decision threshold of 70%. By using a more conservative decision threshold of 30%, this proportion increased to 87%. Overall, the model performed better for the heat wave scenario. By replacing observed temperature data in the model with forecast temperature, from state-of-the-art European forecasting systems, probabilistic mortality predictions could

  14. Modelling Performance: Opening Pandora's Box.

    ERIC Educational Resources Information Center

    McNamara, T. F.

    1995-01-01

    This paper argues that it is necessary for researchers and test developers in the area of language performance testing to have a clear understanding of the role of underlying performance capacities in second language performance. It critically evaluates the models proposed by Hymes, Canale and Swain, and Bachman. (71 references) (MDM)

  15. Modelling Performance: Opening Pandora's Box.

    ERIC Educational Resources Information Center

    McNamara, T. F.

    1995-01-01

    This paper argues that it is necessary for researchers and test developers in the area of language performance testing to have a clear understanding of the role of underlying performance capacities in second language performance. It critically evaluates the models proposed by Hymes, Canale and Swain, and Bachman. (71 references) (MDM)

  16. Numerical and experimental evaluation of the impact performance of advanced high-strength steel sheets based on a damage model

    NASA Astrophysics Data System (ADS)

    Ma, Ning; Park, Taejoon; Kim, Dongun; Kim, Chongmin; Chung, Kwansoo

    2010-06-01

    The impact performance in a Charpy impact test was experimentally and numerically studied for the advanced high-strength steel sheets (AHSS) TWIP940 and TRIP590 as well as the high-strength grade known as 340R. To characterize the mechanical properties, uni-axial simple tension tests were conducted to determine the anisotropic properties and strain rate sensitivities of these materials. In particular, the high-speed strain-rate sensitivity of TRIP590 and 340R (rate sensitive) was also characterized to account for the high strain rates involved in the Charpy impact test. To evaluate fracture behavior in the Charpy impact test, a new damage model including a triaxiality-dependent fracture criterion and hardening behavior with stiffness deterioration was introduced. The model was calibrated via numerical simulations and experiments involving simple tension and V-notch tests. The new damage model along with the anisotropic yield function Hill 1948 was incorporated into the ABAQUS/Explicit FEM code, which performed reasonably well to predict the impact energy absorbed during the Charpy impact test.

  17. Performance evaluation of the Enraf-Nonius Model 872 radar gage

    SciTech Connect

    Peters, T.J.; Park, W.R.

    1992-12-01

    There are indications that the Enraf-Nonius Radar Gage installed in Tank 241-SY-101 may not be providing an accurate reading of the true surface level in the waste tank. The Pacific Northwest Laboratory (PNL) performed an initial study to determine the effect of the following items on the distance read by the gage: Tank riser; Material permittivity and conductivity Foam; Proportion of supernatant to solid material in the field of view of the instrument; Physical geometry of the supernatant and solid material changing in the field of view with respect to time; and Varying water content in the solid material. The results of the tests indicate that distance measured by the radar gage is affected by the permittivity, conductivity, and angle of the target surface. These parameters affect the complex input impedance of the signal received by the radar gage to measure the distance to the target. In Tank 101-SY, the radar gage is placed on top of a 12 in. diameter riser. The riser affects the field of view of the instrument, and a much smaller target surface is detected when the radar beam propagates through a riser. In addition, the riser acts as a waveguide, and standing waves are enhanced between the target surface and the radar gage. The result is a change in the level measured by the radar gage due to changing properties of the target surface even when the distance to the target does not change. The test results indicate that the radar will not detect dry crust or foam. However, if the crust or foam is stirred so that it becomes wet, then the crust or foam became detectable. The level read using the radar gage decreased as the moisture in the crust or foam evaporated.

  18. Performance evaluation of the Enraf-Nonius Model 872 radar gage

    SciTech Connect

    Peters, T.J.; Park, W.R.

    1992-12-01

    There are indications that the Enraf-Nonius Radar Gage installed in Tank 241-SY-101 may not be providing an accurate reading of the true surface level in the waste tank. The Pacific Northwest Laboratory (PNL) performed an initial study to determine the effect of the following items on the distance read by the gage: Tank riser; Material permittivity and conductivity Foam; Proportion of supernatant to solid material in the field of view of the instrument; Physical geometry of the supernatant and solid material changing in the field of view with respect to time; and Varying water content in the solid material. The results of the tests indicate that distance measured by the radar gage is affected by the permittivity, conductivity, and angle of the target surface. These parameters affect the complex input impedance of the signal received by the radar gage to measure the distance to the target. In Tank 101-SY, the radar gage is placed on top of a 12 in. diameter riser. The riser affects the field of view of the instrument, and a much smaller target surface is detected when the radar beam propagates through a riser. In addition, the riser acts as a waveguide, and standing waves are enhanced between the target surface and the radar gage. The result is a change in the level measured by the radar gage due to changing properties of the target surface even when the distance to the target does not change. The test results indicate that the radar will not detect dry crust or foam. However, if the crust or foam is stirred so that it becomes wet, then the crust or foam became detectable. The level read using the radar gage decreased as the moisture in the crust or foam evaporated.

  19. Modeling and performance evaluation of a modified Orwell protocol under symmetrical and asymmetrical traffic distributions

    NASA Astrophysics Data System (ADS)

    Holifield, Phil; Terrell, Trevor; Mars, Philip

    1995-02-01

    With the emergence of Broadband ISDN and the adoption of ATM as its transport mechanism there is a growing interest in slotted ring networks both for high speed packet switching and for multimedia LAN applications. This paper describes a slotted ring testbed which uses a modified Orwell protocol for media access, and which has enabled a study of the modified Orwell protocol under symmetrical and asymmetrical traffic flow distributions. The architecture of the slotted ring testbed is outlined, and analytical models for the protocol are presented for different traffic flow distributions. The analytical results are compared to experimental results obtained from the testbed. The suitability of the reset rate as an indicator of available bandwidth in an access control mechanism is considered, and it is shown that for constant traffic flow and traffic statistics the reset rate works well as an indicator of potential network congestion. Under changing traffic distributions and traffic arrival statistics, additional indicators of congestion are required. On-going work into access control for the test-bed in a integrated services environment is outlined.

  20. Assessing Change in Latent Skills across Time with Longitudinal Cognitive Diagnosis Modeling: An Evaluation of Model Performance

    ERIC Educational Resources Information Center

    Kaya, Yasemin; Leite, Walter L.

    2017-01-01

    Cognitive diagnosis models are diagnostic models used to classify respondents into homogenous groups based on multiple categorical latent variables representing the measured cognitive attributes. This study aims to present longitudinal models for cognitive diagnosis modeling, which can be applied to repeated measurements in order to monitor…

  1. Formative evaluation of a telemedicine model for delivering clinical neurophysiology services part I: Utility, technical performance and service provider perspective

    PubMed Central

    2010-01-01

    Background Formative evaluation is conducted in the early stages of system implementation to assess how it works in practice and to identify opportunities for improving technical and process performance. A formative evaluation of a teleneurophysiology service was conducted to examine its technical and sociological dimensions. Methods A teleneurophysiology service providing routine EEG investigation was established. Service use, technical performance and satisfaction of clinical neurophysiology personnel were assessed qualitatively and quantitatively. These were contrasted with a previously reported analysis of the need for teleneurophysiology, and examination of expectation and satisfaction with clinical neurophysiology services in Ireland. A preliminary cost-benefit analysis was also conducted. Results Over the course of 40 clinical sessions during 20 weeks, 142 EEG investigations were recorded and stored on a file server at a satellite centre which was 130 miles away from the host clinical neurophysiology department. Using a virtual private network, the EEGs were accessed by a consultant neurophysiologist at the host centre for interpretation. The model resulted in a 5-fold increase in access to EEG services as well as reducing average waiting times for investigation by a half. Technically the model worked well, although a temporary loss of virtual private network connectivity highlighted the need for clarity in terms of responsibility for troubleshooting and repair of equipment problems. Referral quality, communication between host and satellite centres, quality of EEG recordings, and ease of EEG review and reporting indicated that appropriate organisational processes were adopted by the service. Compared to traditional CN service delivery, the teleneurophysiology model resulted in a comparable unit cost per EEG. Conclusion Observations suggest that when traditional organisational boundaries are crossed challenges associated with the social dimension of service

  2. Evaluation of nutrition models to estimate performance of young dairy calves: a meta-analytical study under tropical conditions.

    PubMed

    Souza, V L; Drackley, J K; Almeida, R; Bittar, C M M; Albertini, T Z; Morrison, S Y; Lanna, D P D

    2016-12-01

    Mathematical models are important tools to estimate nutritional requirements and animal growth. Very few calf models generated from other countries with different feeding programs, environment and production systems have been evaluated. The objective of this paper is to evaluate two calf models: (i) the National Research Council (NRC) in 2001 and (ii) the updates published by Van Amburgh and Drackley in 2005 and inputted into Agricultural Modeling and Training Systems (AMTS, version 3.5.8). Data from 16 previous studies involving 51 diets for dairy calves under tropical conditions (n=485 calves, initial BW 37.5±4.35 kg and weaning weight of 62.0±10.16 kg) were used. The calves were fed with whole milk, milk replacer or fermented colostrum, plus starter (20.9±1.78% of CP). The accuracy of the average daily gain (ADG) prediction was evaluated by mean bias, mean square prediction error (MSPE), concordance correlation coefficient, bias correction factor (Cb), and regression between the observed and predicted values. The ADG observed from birth to weaning was 0.452±0.121 kg/day. Calves fed with whole milk had greater ADG compared with calves fed milk replacer (0.477 v. 0.379 kg/day) during the milk-feeding period. When all data were pooled (n=51 diets), predictions had a mean bias of -0.019 and 0.068 kg/day for energy-allowable gain using NRC and AMTS models, respectively. The regression equation between observed and predicted values obtained from energy of diets showed an intercept different from zero (P0.05) indicate that the AMTS growth model resulted in accurate predictions for calves fed with milk replacer. However, within these latter two approaches, the goodness of fit (R 2) was low, representing low precision. The weight gain estimated by the energy available from the diet was overestimated by 19 g/day when calculated by the NRC and underestimated by 68 g/day when calculated by AMTS. The reasons for this discrepancy need to be understood, for only then new

  3. The statistical performance of an MCF-7 cell culture assay evaluated using generalized linear mixed models and a score test.

    PubMed

    Rey deCastro, B; Neuberg, Donna

    2007-05-30

    Biological assays often utilize experimental designs where observations are replicated at multiple levels, and where each level represents a separate component of the assay's overall variance. Statistical analysis of such data usually ignores these design effects, whereas more sophisticated methods would improve the statistical power of assays. This report evaluates the statistical performance of an in vitro MCF-7 cell proliferation assay (E-SCREEN) by identifying the optimal generalized linear mixed model (GLMM) that accurately represents the assay's experimental design and variance components. Our statistical assessment found that 17beta-oestradiol cell culture assay data were best modelled with a GLMM configured with a reciprocal link function, a gamma error distribution, and three sources of design variation: plate-to-plate; well-to-well, and the interaction between plate-to-plate variation and dose. The gamma-distributed random error of the assay was estimated to have a coefficient of variation (COV) = 3.2 per cent, and a variance component score test described by X. Lin found that each of the three variance components were statistically significant. The optimal GLMM also confirmed the estrogenicity of five weakly oestrogenic polychlorinated biphenyls (PCBs 17, 49, 66, 74, and 128). Based on information criteria, the optimal gamma GLMM consistently out-performed equivalent naive normal and log-normal linear models, both with and without random effects terms. Because the gamma GLMM was by far the best model on conceptual and empirical grounds, and requires only trivially more effort to use, we encourage its use and suggest that naive models be avoided when possible. Copyright 2006 John Wiley & Sons, Ltd.

  4. CMIP5 Global Climate Model Performance Evaluation and Climate Scenario Development over the South-Central United States

    NASA Astrophysics Data System (ADS)

    Rosendahl, D. H.; Rupp, D. E.; Mcpherson, R. A.; Moore, B., III

    2015-12-01

    Future climate change projections from Global Climate Models (GCMs) are the primary drivers of regional downscaling and impacts research - from which relevant information for stakeholders is generated at the regional and local levels. Therefore understanding uncertainties in GCMs is a fundamental necessity if the scientific community is to provide useful and reliable future climate change information that can be utilized by end users and decision makers. Two different assessments of the Coupled Model Intercomparison Project Phase 5 (CMIP5) GCM ensemble were conducted for the south-central United States. The first was a performance evaluation over the historical period for metrics of near surface meteorological variables (e.g., temperature, precipitation) and system-based phenomena, which include large-scale processes that can influence the region (e.g., low-level jet, ENSO). These metrics were used to identify a subset of models of higher performance across the region which were then used to constrain future climate change projections. A second assessment explored climate scenario development where all model climate change projections were assumed equally likely and future projections with the highest impact were identified (e.g., temperature and precipitation combinations of hottest/driest, hottest/wettest, and highest variability). Each of these assessments identify a subset of models that may prove useful to regional downscaling and impacts researchers who may be restricted by the total number of GCMs they can utilize. Results from these assessments will be provided as well as a discussion on when each would be useful and appropriate to use.

  5. CMAQ Model Evaluation Framework

    EPA Pesticide Factsheets

    CMAQ is tested to establish the modeling system’s credibility in predicting pollutants such as ozone and particulate matter. Evaluation of CMAQ has been designed to assess the model’s performance for specific time periods and for specific uses.

  6. Evaluating stress as a challenge is associated with superior attentional control and motor skill performance: testing the predictions of the biopsychosocial model of challenge and threat.

    PubMed

    Vine, Samuel J; Freeman, Paul; Moore, Lee J; Chandra-Ramanan, Roy; Wilson, Mark R

    2013-09-01

    The biopsychosocial model of challenge and threat (Blascovich, 2008) suggests that individuals who evaluate a performance situation as a challenge will perform better than those who evaluate it as a threat. However, limited research has examined (a) the influence of challenge and threat evaluations on learned motor performance under pressure and (b) the attentional processes by which this effect occurs. In the present study 52 novices performed a motor task (laparoscopic surgery), for which optimal visual attentional control has been established. Participants performed a Baseline trial (when the task was novel) and were then trained to proficiency before performing under pressurized conditions designed to increase anxiety (Pressure). At Baseline, regression analyses were performed to examine the relationship between challenge/threat evaluations and the outcome variables (performance, cardiovascular response, and visual attention). At Pressure, hierarchical regression analyses (controlling for the degree of learning) were performed to examine the relationship between challenge/threat evaluations and the outcome variables. At both Baseline and Pressure tests evaluating the task as more of a challenge was associated with more effective attentional control and superior performance. In the Baseline test, evaluating the task as more of a challenge was associated with differential cardiovascular responses. Although there is some support for an attentional explanation of differential performance effects, additional analyses did not reveal mediators of the relationship between challenge/threat evaluations and motor performance. The findings have implications for the training and performance of motor skills in pressurized environments (e.g., surgery, sport, aviation).

  7. Evaluation of Performance Based Logistics

    DTIC Science & Technology

    2006-08-01

    logistics warehouse provider (see Figure 11 below). NAVICP-P 3PL Warehouse Provider Lockheed Martin Michelin Government Prime Contractor Subcontractor...Evaluation of Performance Based Logistics by Jacques S. Gansler and William Lucyshyn August...REPORT DATE AUG 2006 2. REPORT TYPE 3. DATES COVERED 00-00-2006 to 00-00-2006 4. TITLE AND SUBTITLE Evaluation of Performance Based Logistics

  8. Evaluating and Improving Teacher Performance.

    ERIC Educational Resources Information Center

    Manatt, Richard P.

    This workbook, coordinated with Manatt Teacher Performance Evaluation (TPE) workshops, summarizes large group presentation in sequence with the transparancies used. The first four modules of the workbook deal with the state of the art of evaluating and improving teacher performance; the development of the TPE system, including selection of…

  9. Photovoltaic array performance model.

    SciTech Connect

    Kratochvil, Jay A.; Boyson, William Earl; King, David L.

    2004-08-01

    This document summarizes the equations and applications associated with the photovoltaic array performance model developed at Sandia National Laboratories over the last twelve years. Electrical, thermal, and optical characteristics for photovoltaic modules are included in the model, and the model is designed to use hourly solar resource and meteorological data. The versatility and accuracy of the model has been validated for flat-plate modules (all technologies) and for concentrator modules, as well as for large arrays of modules. Applications include system design and sizing, 'translation' of field performance measurements to standard reporting conditions, system performance optimization, and real-time comparison of measured versus expected system performance.

  10. Application and validation of an advanced gastrointestinal in vitro model for the evaluation of drug product performance in pharmaceutical development.

    PubMed

    Barker, Richard; Abrahamsson, Bertil; Kruusmägi, Martin

    2014-11-01

    Methods to understand and predict the oral bioavailability of drug products are a prioritized research area within the pharmaceutical industry. Models to predict oral bioavailability have the potential to reduce risk, time, and cost in development as well as decrease the need for animal studies. The TNO intestinal model (TIM-1) is an advanced dissolution model deployed by AstraZeneca since 2008. This article presents a systematic evaluation of TIM-1 against in vivo data. The relative performance of compounds and formulations tested in TIM-1 and in vivo was compared both by a qualitative analysis and a linear regression analysis of relative exposure measures between test and reference formulations in TIM-1 and in vivo. The TIM-1 correctly predicted in vivo rank order in 84% and 79% of cases for AUC and Cmax , respectively, when using the 3-h time point. There was only one case for Cmax in which TIM-1 did not predict an in vivo difference. The correlation coefficient (R(2) ) between relative (test vs. reference formulations) fraction available in TIM-1 after 3 h and AUC was 0.78. Thus, this study suggests that the TIM-1 system can be used to assess the risk for significant differences in exposure between formulations and compound modifications. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  11. IrBurst Modeling and Performance Evaluation for Large Data Block Exchange over High-Speed IrDA Links

    NASA Astrophysics Data System (ADS)

    Alam, Mohammad Shah; Shawkat, Shamim Ara; Kitazumi, Gontaro; Matsumoto, Mitsuji

    IrBurst, recently proposed by IrDA, is a high speed information transmission protocol. In this paper, a mathematical model is developed which leads to derivation of the IrBurst throughput over the IrDA protocol stack. Based on this model, we compare the performance of IrBurst and existing OBEX protocol in order to investigate the suitability of IrBurst protocol for exchange of large data blocks over high-speed IrDA links. Furthermore, the model allows the evaluation of the impact of the link layer parameters, such as window size and frame length, and physical layer parameters, such as minimum turnaround time, on system through-put for high-speed IrDA links and in the presence of transmission errors. Consequently, an effective Automatic Repeat Request (ARQ) scheme is proposed at link layer to maximize the throughput efficiency for IrBurst protocol as well as for next generation high speed IrDA links. Simulation result indicates that employment of our proposed ARQ scheme results in significant improvement of IrBurst throughput efficiency at high bit error rates.

  12. Multiprocessor performance modeling with ADAS

    NASA Technical Reports Server (NTRS)

    Hayes, Paul J.; Andrews, Asa M.

    1989-01-01

    A graph managing strategy referred to as the Algorithm to Architecture Mapping Model (ATAMM) appears useful for the time-optimized execution of application algorithm graphs in embedded multiprocessors and for the performance prediction of graph designs. This paper reports the modeling of ATAMM in the Architecture Design and Assessment System (ADAS) to make an independent verification of ATAMM's performance prediction capability and to provide a user framework for the evaluation of arbitrary algorithm graphs. Following an overview of ATAMM and its major functional rules are descriptions of the ADAS model of ATAMM, methods to enter an arbitrary graph into the model, and techniques to analyze the simulation results. The performance of a 7-node graph example is evaluated using the ADAS model and verifies the ATAMM concept by substantiating previously published performance results.

  13. Multiprocessor performance modeling with ADAS

    NASA Technical Reports Server (NTRS)

    Hayes, Paul J.; Andrews, Asa M.

    1989-01-01

    A graph managing strategy referred to as the Algorithm to Architecture Mapping Model (ATAMM) appears useful for the time-optimized execution of application algorithm graphs in embedded multiprocessors and for the performance prediction of graph designs. This paper reports the modeling of ATAMM in the Architecture Design and Assessment System (ADAS) to make an independent verification of ATAMM's performance prediction capability and to provide a user framework for the evaluation of arbitrary algorithm graphs. Following an overview of ATAMM and its major functional rules are descriptions of the ADAS model of ATAMM, methods to enter an arbitrary graph into the model, and techniques to analyze the simulation results. The performance of a 7-node graph example is evaluated using the ADAS model and verifies the ATAMM concept by substantiating previously published performance results.

  14. Evaluating, interpreting, and communicating performance of hydrologic/water quality models considering intended use: A review and recommendations

    USDA-ARS?s Scientific Manuscript database

    Previous publications have outlined recommended practices for hydrologic and water quality (H/WQ) modeling, but none have formulated comprehensive guidelines for the final stage of modeling applications, namely evaluation, interpretation, and communication of model results and the consideration of t...

  15. Family incivility and job performance: a moderated mediation model of psychological distress and core self-evaluation.

    PubMed

    Lim, Sandy; Tai, Kenneth

    2014-03-01

    This study extends the stress literature by exploring the relationship between family incivility and job performance. We examine whether psychological distress mediates the link between family incivility and job performance. We also investigate how core self-evaluation might moderate this mediated relationship. Data from a 2-wave study indicate that psychological distress mediates the relationship between family incivility and job performance. In addition, core self-evaluation moderates the relationship between family incivility and psychological distress but not the relationship between psychological distress and job performance. The results hold while controlling for general job stress, family-to-work conflict, and work-to-family conflict. The findings suggest that family incivility is linked to poor performance at work, and psychological distress and core self-evaluation are key mechanisms in the relationship.

  16. Use of Mathematical Models in the Design and Performance Evaluation of a Surfactant Flushing Demonstration at the Bachman Road Site

    NASA Astrophysics Data System (ADS)

    Abriola, L. M.; Drummond, C. D.; Lemke, L. D.; Rathfelder, K. M.; Pennell, K. D.

    2001-05-01

    This presentation provides an overview of the design and performance evaluation of a surfactant enhanced remediation pilot demonstration conducted in the summer of 2000 at a former dry cleaning facility in Oscoda, Michigan, USA. The unconfined contaminated formation is composed of relatively homogeneous glacial outwash sands, underlain by a thick clay layer. Core samples have revealed the presence of a reasonably persistent coarse sand and gravel layer at a depth of 11-16 feet and a sand/silt/clay transition zone at the base of the aquifer. A narrow tetrachloroethylene (PCE) plume emanates from the suspected source area, beneath the former dry cleaning building, and discharges into Lake Huron, approximately 700 feet down gradient. There is little evidence of microbial plume attenuation at the site. Aqueous samples from multilevel piezometers installed beneath the building have confirmed the presence of residual PCE within the coarse sand and gravel layer and have detected consistently high PCE concentrations at the base of the aquifer. The actual distribution and volume of entrapped PCE, however, is unknown. A surfactant injection and recovery scheme was designed and implemented to effectively flush the identified source area beneath the building. In this scheme, a line of water injection wells was installed behind the surfactant injection points to control surfactant delivery and maximize solubilized plume capture. Prior to surfactant injection, conservative and partitioning tracer tests were also conducted to confirm sweep and estimate source zone mass. Mass recovery calculations indicate that more than 94% of the injected surfactant and approximately 19 liters of PCE were recovered during the test. This volume of DNAPL is consistent with estimated low saturations within the swept zone. Single and multiphase transport models were employed to aid in remedial design and predict system performance. For the model simulations, input parameters were determined from

  17. Quantification of leachate discharged to groundwater using the water balance method and the hydrologic evaluation of landfill performance (HELP) model.

    PubMed

    Alslaibi, Tamer M; Abustan, Ismail; Mogheir, Yunes K; Afifi, Samir

    2013-01-01

    Landfills are a source of groundwater pollution in Gaza Strip. This study focused on Deir Al Balah landfill, which is a unique sanitary landfill site in Gaza Strip (i.e., it has a lining system and a leachate recirculation system). The objective of this article is to assess the generated leachate quantity and percolation to the groundwater aquifer at a specific site, using the approaches of (i) the hydrologic evaluation of landfill performance model (HELP) and (ii) the water balance method (WBM). The results show that when using the HELP model, the average volume of leachate discharged from Deir Al Balah landfill during the period 1997 to 2007 was around, 6800 m3/year. Meanwhile, the average volume of leachate percolated through the clay layer was 550 m3/year, which represents around 8% of the generated leachate. Meanwhile, the WBM indicated that the average volume of leachate discharged from Deir Al Balah landfill during the same period was around 7660 m3/year--about half of which comes from the moisture content of the waste, while the remainder comes from the infiltration of precipitation and re-circulated leachate. Therefore, the estimated quantity of leachate to groundwater by these two methods was very close. However, compared with the measured leachate quantity, these results were overestimated and indicated a dangerous threat to the groundwater aquifer, as there was no separation between municipal, hazardous and industrial wastes, in the area.

  18. Evaluating Model Performance of an Ensemble-based Chemical Data Assimilation System During INTEX-B Field Mission

    NASA Technical Reports Server (NTRS)

    Arellano, A. F., Jr.; Raeder, K.; Anderson, J. L.; Hess, P. G.; Emmons, L. K.; Edwards, D. P.; Pfister, G. G.; Campos, T. L.; Sachse, G. W.

    2007-01-01

    We present a global chemical data assimilation system using a global atmosphere model, the Community Atmosphere Model (CAM3) with simplified chemistry and the Data Assimilation Research Testbed (DART) assimilation package. DART is a community software facility for assimilation studies using the ensemble Kalman filter approach. Here, we apply the assimilation system to constrain global tropospheric carbon monoxide (CO) by assimilating meteorological observations of temperature and horizontal wind velocity and satellite CO retrievals from the Measurement of Pollution in the Troposphere (MOPITT) satellite instrument. We verify the system performance using independent CO observations taken on board the NSFINCAR C-130 and NASA DC-8 aircrafts during the April 2006 part of the Intercontinental Chemical Transport Experiment (INTEX-B). Our evaluations show that MOPITT data assimilation provides significant improvements in terms of capturing the observed CO variability relative to no MOPITT assimilation (i.e. the correlation improves from 0.62 to 0.71, significant at 99% confidence). The assimilation provides evidence of median CO loading of about 150 ppbv at 700 hPa over the NE Pacific during April 2006. This is marginally higher than the modeled CO with no MOPITT assimilation (-140 ppbv). Our ensemble-based estimates of model uncertainty also show model overprediction over the source region (i.e. China) and underprediction over the NE Pacific, suggesting model errors that cannot be readily explained by emissions alone. These results have important implications for improving regional chemical forecasts and for inverse modeling of CO sources and further demonstrate the utility of the assimilation system in comparing non-coincident measurements, e.g. comparing satellite retrievals of CO with in-situ aircraft measurements. The work described above also brought to light several short-comings of the data assimilation approach for CO profiles. Because of the limited vertical

  19. Evaluating Model Performance of an Ensemble-based Chemical Data Assimilation System During INTEX-B Field Mission

    NASA Technical Reports Server (NTRS)

    Arellano, A. F., Jr.; Raeder, K.; Anderson, J. L.; Hess, P. G.; Emmons, L. K.; Edwards, D. P.; Pfister, G. G.; Campos, T. L.; Sachse, G. W.

    2007-01-01

    We present a global chemical data assimilation system using a global atmosphere model, the Community Atmosphere Model (CAM3) with simplified chemistry and the Data Assimilation Research Testbed (DART) assimilation package. DART is a community software facility for assimilation studies using the ensemble Kalman filter approach. Here, we apply the assimilation system to constrain global tropospheric carbon monoxide (CO) by assimilating meteorological observations of temperature and horizontal wind velocity and satellite CO retrievals from the Measurement of Pollution in the Troposphere (MOPITT) satellite instrument. We verify the system performance using independent CO observations taken on board the NSFINCAR C-130 and NASA DC-8 aircrafts during the April 2006 part of the Intercontinental Chemical Transport Experiment (INTEX-B). Our evaluations show that MOPITT data assimilation provides significant improvements in terms of capturing the observed CO variability relative to no MOPITT assimilation (i.e. the correlation improves from 0.62 to 0.71, significant at 99% confidence). The assimilation provides evidence of median CO loading of about 150 ppbv at 700 hPa over the NE Pacific during April 2006. This is marginally higher than the modeled CO with no MOPITT assimilation (-140 ppbv). Our ensemble-based estimates of model uncertainty also show model overprediction over the source region (i.e. China) and underprediction over the NE Pacific, suggesting model errors that cannot be readily explained by emissions alone. These results have important implications for improving regional chemical forecasts and for inverse modeling of CO sources and further demonstrate the utility of the assimilation system in comparing non-coincident measurements, e.g. comparing satellite retrievals of CO with in-situ aircraft measurements. The work described above also brought to light several short-comings of the data assimilation approach for CO profiles. Because of the limited vertical

  20. Evaluation of the performance of the WRF 1-Dimensional Lake model over the East Africa Great Lakes

    NASA Astrophysics Data System (ADS)

    Gudoshava, M.; Semazzi, F. H. M.

    2015-12-01

    This study seeks to investigate the performance of the 1-Dimensional lake model coupled to WRF over East Africa. The Africa Great lakes exert a great influence on the climate of the region and a number of studies have shown how the lake influences the circulation and the total precipitation over the region. The lakes have highly variable depths, with Lake Victoria having an average depth of 40m and Lake Tanganyika a depth of 450m. The Lake model for WRF was tested and calibrated for the Great lakes, however it was not tested for tropical lakes. We hypothesize that the inclusion of a 1-dimensional lake will reduce the precipitation bias as compared to the WRF model without the lake model. In addition initializing the lake temperature using a vertical temperature profile that closes resembles the one over these lakes will greatly reduce the spin up time. The simulations utilized three nested domains at 36, 12 and 4km. The 4km domain is centered over Lake Victoria Basin, while the 12 km domain includes all the lakes in East Africa. The Tropical Rainfall Measuring Mission (TRMM) datasets are used in evaluating the precipitation, and the following statistics were calculated: root mean square error, standard deviation of the model and observations and mean bias. The results show that the use of the 1-dimensional lake model improves the precipitation over the region considerably compared to an uncoupled model. The asymmetrical rainfall pattern is evident in the simulations. However using the default vertical temperature profile with a three-month spin up is not adequate to transfer heat to the bottom of the lake. Hence the temperatures are still very cold at the bottom. A nine-month spin up improves the lake surface temperatures and lake temperatures at the bottom. A two year spin up greatly improves the lake surface temperatures and hence the total precipitation over the lake. Thus longer spin up time allows for adequate heat transfer in the lake. Initializing the

  1. Design and performance evaluation of a simplified dynamic model for combined sewer overflows in pumped sewer systems

    NASA Astrophysics Data System (ADS)

    van Daal-Rombouts, Petra; Sun, Siao; Langeveld, Jeroen; Bertrand-Krajewski, Jean-Luc; Clemens, François

    2016-07-01

    Optimisation or real time control (RTC) studies in wastewater systems increasingly require rapid simulations of sewer systems in extensive catchments. To reduce the simulation time calibrated simplified models are applied, with the performance generally based on the goodness of fit of the calibration. In this research the performance of three simplified and a full hydrodynamic (FH) model for two catchments are compared based on the correct determination of CSO event occurrences and of the total discharged volumes to the surface water. Simplified model M1 consists of a rainfall runoff outflow (RRO) model only. M2 combines the RRO model with a static reservoir model for the sewer behaviour. M3 comprises the RRO model and a dynamic reservoir model. The dynamic reservoir characteristics were derived from FH model simulations. It was found that M2 and M3 are able to describe the sewer behaviour of the catchments, contrary to M1. The preferred model structure depends on the quality of the information (geometrical database and monitoring data) available for the design and calibration of the model. Finally, calibrated simplified models are shown to be preferable to uncalibrated FH models when performing optimisation or RTC studies.

  2. Evaluation of atmospheric nitrogen deposition model performance in the context of U.S. critical load assessments

    NASA Astrophysics Data System (ADS)

    Williams, Jason J.; Chung, Serena H.; Johansen, Anne M.; Lamb, Brian K.; Vaughan, Joseph K.; Beutel, Marc

    2017-02-01

    Air quality models are widely used to estimate pollutant deposition rates and thereby calculate critical loads and critical load exceedances (model deposition > critical load). However, model operational performance is not always quantified specifically to inform these applications. We developed a performance assessment approach designed to inform critical load and exceedance calculations, and applied it to the Pacific Northwest region of the U.S. We quantified wet inorganic N deposition performance of several widely-used air quality models, including five different Community Multiscale Air Quality Model (CMAQ) simulations, the Tdep model, and 'PRISM x NTN' model. Modeled wet inorganic N deposition estimates were compared to wet inorganic N deposition measurements at 16 National Trends Network (NTN) monitoring sites, and to annual bulk inorganic N deposition measurements at Mount Rainier National Park. Model bias (model - observed) and error (|model - observed|) were expressed as a percentage of regional critical load values for diatoms and lichens. This novel approach demonstrated that wet inorganic N deposition bias in the Pacific Northwest approached or exceeded 100% of regional diatom and lichen critical load values at several individual monitoring sites, and approached or exceeded 50% of critical loads when averaged regionally. Even models that adjusted deposition estimates based on deposition measurements to reduce bias or that spatially-interpolated measurement data, had bias that approached or exceeded critical loads at some locations. While wet inorganic N deposition model bias is only one source of uncertainty that can affect critical load and exceedance calculations, results demonstrate expressing bias as a percentage of critical loads at a spatial scale consistent with calculations may be a useful exercise for those performing calculations. It may help decide if model performance is adequate for a particular calculation, help assess confidence in

  3. Room for Improvement: Performance Evaluations.

    ERIC Educational Resources Information Center

    Webb, Gisela

    1989-01-01

    Describes a performance management approach to library personnel management that stresses communication, clarification of goals, and reinforcement of new practices and behaviors. Each phase of the evaluation process (preparation, rating, administrative review, appraisal interview, and follow-up) and special evaluations to be used in cases of…

  4. EVALUATING THE PERFORMANCE OF REGIONAL-SCALE PHOTOCHEMICAL MODELING SYSTEMS: PART II--OZONE PREDICTIONS. (R825260)

    EPA Science Inventory

    In this paper, the concept of scale analysis is applied to evaluate ozone predictions from two regional-scale air quality models. To this end, seasonal time series of observations and predictions from the RAMS3b/UAM-V and MM5/MAQSIP (SMRAQ) modeling systems for ozone were spectra...

  5. EVALUATING THE PERFORMANCE OF REGIONAL-SCALE PHOTOCHEMICAL MODELING SYSTEMS: PART I--METEOROLOGICAL PREDICTIONS. (R825260)

    EPA Science Inventory

    In this study, the concept of scale analysis is applied to evaluate two state-of-science meteorological models, namely MM5 and RAMS3b, currently being used to drive regional-scale air quality models. To this end, seasonal time series of observations and predictions for temperatur...

  6. The supervisor's performance appraisal: evaluating the evaluator.

    PubMed

    McConnell, C R

    1993-04-01

    The focus of much performance appraisal in the coming decade or so will likely be on the level of customer satisfaction achieved through performance. Ultimately, evaluating the evaluator--that is, appraising the supervisor--will likely become a matter of assessing how well the supervisor's department meets the needs of its customers. Since meeting the needs of one's customers can well become the strongest determinant of organizational success or failure, it follows that relative success in ensuring these needs are met can become the primary indicator of one's relative success as a supervisor. This has the effect of placing the emphasis on supervisory performance exactly at the point it belongs, right on the bottom-line results of the supervisor's efforts.

  7. Evaluation of performance of a BLSS model in long-term operation in dynamic and steady states

    NASA Astrophysics Data System (ADS)

    Gros, Jean-Bernard; Tikhomirov, Alex; Ushakova, Sofya; Velitchko, Vladimir; Tikhomirova, Natalia; Lasseur, Christophe

    Evaluation of performance of a BLSS model, including higher plants for food production and biodegradation of human waste, in long-term operation in dynamic and steady states was performed. The model system was conceived for supplying vegetarian food and oxygen to 0.07 human. The following data were obtained in steady-state operating conditions. Average rate of wheat, chufa, radish, lettuce and Salicornia edible biomass accumulation were 8.7, 5.5, 0.6, 0.6 and metricconverterProductID2.5 g2.5 g per day respectively. Thus, to mimic the vegetarian edible biomass consumption by a human it was necessary to withdraw 17.9 g/d from total mass ex-change. Simultaneously, human mineralized exometabolites (artificial mineralized urine, AMU) in the amount of approximately 7% of a daily norm were introduced into the nutrient solu-tion for irrigation of the plants cultivated on a neutral substrate (expanded clay aggregate). The estimated value of 5.8 g/d of wheat and Salicornia inedible biomass was introduced in the soil-like substrate (SLS) to fully meet the plants need in nitrogen. The rest of wheat and Salicornia inedible biomass, 5.7 g/d, was stored. Thus in all, 23.6g of vegetarian dry matter had been stored. Assuming edible biomass is eaten up by the human, the closure coefficient of the vegetarian biomass inclusion into matter recycling amounted to 88%. The analysis of the long-term model operation showed that the main factors limiting increase of recycling processes were the following: a) Partly unbalanced mineral composition of daily human waste with daily needs of plants culti-` vated in the system. Thus, when fully satisfied with respect to nitrogen, the plants experienced a lack of macro elements such as P, Mg and Ca by more than 50%; b) Partly unbalanced mineral composition of edible biomass of the plants cultivated in the SLS with that of inedible biomass of the plants cultivated by hydroponic method on neutral substrate introduced in the SLS; c) Accumulation of

  8. Evaluation of the Mesoscale Meteorological Model (MM5)-Community Multi-Scale Air Quality Model (CMAQ) performance in hindcast and forecast of ground-level ozone.

    PubMed

    Nghiem, Le Hoang; Kim Oanh, Nguyen Thi

    2008-10-01

    This paper presents the first attempt to apply the Mesoscale Meteorological Model (MM5)-Community Multi-Scale Air Quality Model (CMAQ) model system to simulate ground-level ozone (O3) over the continental Southeast Asia (CSEA) region for both hindcast and forecast purposes. Hindcast simulation was done over the CSEA domain for two historical O3 episodes, January 26-29, 2004 (January episode, northeast monsoon) and March 24-26, 2004 (March episode, southwest monsoon). Experimental forecast was done for next-day hourly O3 during January 2006 over the central part of Thailand (CENTHAI). Available data from 20 ambient monitoring stations in Thailand and 3 stations in Ho Chi Minh City, Vietnam, were used for the episode analysis and for the model performance evaluation. The year 2000 anthropogenic emission inventory prepared by the Center for Global and Regional Environmental Research at the University of Iowa was projected to the simulation year on the basis of the regional average economic growth rate. Hourly emission in urban areas was prepared using ambient carbon monoxide concentration as a surrogate for the emission intensity. Biogenic emissions were estimated based on data from the Global Emissions Inventory Activity. Hindcast simulations (CSEA) were performed with 0.5 degree x 0.5 degree resolution, whereas forecast simulations (CENTHAI) were done with 0.1 degree x 0.1 degree hourly emission input data. MM5-CMAQ model system performance during the selected episodes satisfactorily met U.S. Environmental Protection Agency criteria for O3 for most simulated days. The experiment forecast for next-day hourly O3 in January 2006 yielded promising results. Modeled plumes of ozone in both hindcast and forecast cases agreed with the main wind fields and extended over considerable downwind distances from large urban areas.

  9. Avoidance temperament and social-evaluative threat in college students' math performance: a mediation model of math and test anxiety.

    PubMed

    Liew, Jeffrey; Lench, Heather C; Kao, Grace; Yeh, Yu-Chen; Kwok, Oi-man

    2014-01-01

    Standardized testing has become a common form of student evaluation with high stakes, and limited research exists on understanding the roles of students' personality traits and social-evaluative threat on their academic performance. This study examined the roles of avoidance temperament (i.e., fear and behavioral inhibition) and evaluative threat (i.e., fear of failure and being viewed as unintelligent) in standardized math test and course grades in college students. Undergraduate students (N=184) from a large public university were assessed on temperamental fear and behavioral inhibition. They were then given 15 minutes to complete a standardized math test. After the test, students provided data on evaluative threat and their math performance (scores on standardized college entrance exam and average grades in college math courses). Results indicate that avoidance temperament was linked to social-evaluative threat and low standardized math test scores. Furthermore, evaluative threat mediated the influence of avoidance temperament on both types of math performance. Results have educational and clinical implications, particularly for students at risk for test anxiety and underperformance. Interventions targeting emotion regulation and stress management skills may help individuals reduce their math and test anxieties.

  10. Hydrologic Evaluation of Landfill Performance (HELP) Model: B (Set Includes, A- User's Guide for Version 3 w/disks, B-Engineering Documentation for Version 3

    EPA Science Inventory

    The Hydrologic Evaluation of Landfill Performance (HELP) computer program is a quasi-two-dimensional hydrologic model of water movement across, into, through and out of landfills. The model accepts weather, soil and design data. Landfill systems including various combinations o...

  11. Hydrologic Evaluation of Landfill Performance (HELP) Model: B (Set Includes, A- User's Guide for Version 3 w/disks, B-Engineering Documentation for Version 3

    EPA Science Inventory

    The Hydrologic Evaluation of Landfill Performance (HELP) computer program is a quasi-two-dimensional hydrologic model of water movement across, into, through and out of landfills. The model accepts weather, soil and design data. Landfill systems including various combinations o...

  12. Developing a performance evaluation functional model for cities impacted by a natural hazard: application to a city affected by flooding

    NASA Astrophysics Data System (ADS)

    Bambara, G.; Peyras, L.; Felix, H.; Serre, D.

    2014-06-01

    The experience feedback on a crisis that hit a city is frequently used as a "recollection" tool. However, it may not be held in itself as a tool for analyzing a city's performance. The city, considered as a complex system, was modeled using a functional analysis method. Based on such modeling, two risk analysis methods (Failure Mode and Effect Analysis and Event Tree Method) were deployed and adjusted. Lastly, a qualitative reasoning model had been used for get the scenario modeling of the urban crisis. Such functional model was deployed on a case study.

  13. The Effect of Social Roles and Performance Cues on Self-Evaluations: Evidence for an Interpersonal Model of Loneliness.

    ERIC Educational Resources Information Center

    Vitkus, John

    Vitkus and Horowitz (1987) found that lonely people demonstrated adequate social behavior when they were assigned to controlling interpersonal roles. Despite this successful performance, they evaluated themselves and their behavior negatively. Study 1 replicated these findings and extended them to naturalistic interactions. In a hypothetical…

  14. Using the coupled wake boundary layer model to evaluate the effect of turbulence intensity on wind farm performance

    NASA Astrophysics Data System (ADS)

    Stevens, Richard J. A. M.; Gayme, Dennice; Meneveau, Charles

    2015-06-01

    We use the recently introduced coupled wake boundary layer (CWBL) model to predict the effect of turbulence intensity on the performance of a wind farm. The CWBL model combines a standard wake model with a “top-down” approach to get improved predictions for the power output compared to a stand-alone wake model. Here we compare the CWBL model results for different turbulence intensities with the Horns Rev field measurements by Hansen et al., Wind Energy 15, 183196 (2012). We show that the main trends as function of the turbulence intensity are captured very well by the model and discuss differences between the field measurements and model results based on comparisons with LES results from Wu and Porté-Agel, Renewable Energy 75, 945-955 (2015).

  15. Repository Integration Program: RIP performance assessment and strategy evaluation model theory manual and user`s guide

    SciTech Connect

    1995-11-01

    This report describes the theory and capabilities of RIP (Repository Integration Program). RIP is a powerful and flexible computational tool for carrying out probabilistic integrated total system performance assessments for geologic repositories. The primary purpose of RIP is to provide a management tool for guiding system design and site characterization. In addition, the performance assessment model (and the process of eliciting model input) can act as a mechanism for integrating the large amount of available information into a meaningful whole (in a sense, allowing one to keep the ``big picture`` and the ultimate aims of the project clearly in focus). Such an integration is useful both for project managers and project scientists. RIP is based on a `` top down`` approach to performance assessment that concentrates on the integration of the entire system, and utilizes relatively high-level descriptive models and parameters. The key point in the application of such a ``top down`` approach is that the simplified models and associated high-level parameters must incorporate an accurate representation of their uncertainty. RIP is designed in a very flexible manner such that details can be readily added to various components of the model without modifying the computer code. Uncertainty is also handled in a very flexible manner, and both parameter and model (process) uncertainty can be explicitly considered. Uncertainty is propagated through the integrated PA model using an enhanced Monte Carlo method. RIP must rely heavily on subjective assessment (expert opinion) for much of its input. The process of eliciting the high-level input parameters required for RIP is critical to its successful application. As a result, in order for any project to successfully apply a tool such as RIP, an enormous amount of communication and cooperation must exist between the data collectors, the process modelers, and the performance. assessment modelers.

  16. Energy performance evaluation of AAC

    NASA Astrophysics Data System (ADS)

    Aybek, Hulya

    The U.S. building industry constitutes the largest consumer of energy (i.e., electricity, natural gas, petroleum) in the world. The building sector uses almost 41 percent of the primary energy and approximately 72 percent of the available electricity in the United States. As global energy-generating resources are being depleted at exponential rates, the amount of energy consumed and wasted cannot be ignored. Professionals concerned about the environment have placed a high priority on finding solutions that reduce energy consumption while maintaining occupant comfort. Sustainable design and the judicious combination of building materials comprise one solution to this problem. A future including sustainable energy may result from using energy simulation software to accurately estimate energy consumption and from applying building materials that achieve the potential results derived through simulation analysis. Energy-modeling tools assist professionals with making informed decisions about energy performance during the early planning phases of a design project, such as determining the most advantageous combination of building materials, choosing mechanical systems, and determining building orientation on the site. By implementing energy simulation software to estimate the effect of these factors on the energy consumption of a building, designers can make adjustments to their designs during the design phase when the effect on cost is minimal. The primary objective of this research consisted of identifying a method with which to properly select energy-efficient building materials and involved evaluating the potential of these materials to earn LEED credits when properly applied to a structure. In addition, this objective included establishing a framework that provides suggestions for improvements to currently available simulation software that enhance the viability of the estimates concerning energy efficiency and the achievements of LEED credits. The primary objective

  17. GUIDANCE FOR THE PERFORMANCE EVALUATION OF THREE-DIMENSIONAL AIR QUALITY MODELING SYSTEMS FOR PARTICULATE MATTER AND VISIBILITY

    EPA Science Inventory

    The National Ambient Air Quality Standards for particulate matter (PM) and the federal regional haze regulations place some emphasis on the assessment of fine particle (PM; 5) concentrations. Current air quality models need to be improved and evaluated against observations to a...

  18. Ion thruster performance model

    NASA Technical Reports Server (NTRS)

    Brophy, J. R.

    1984-01-01

    A model of ion thruster performance is developed for high flux density, cusped magnetic field thruster designs. This model is formulated in terms of the average energy required to produce an ion in the discharge chamber plasma and the fraction of these ions that are extracted to form the beam. The direct loss of high energy (primary) electrons from the plasma to the anode is shown to have a major effect on thruster performance. The model provides simple algebraic equations enabling one to calculate the beam ion energy cost, the average discharge chamber plasma ion energy cost, the primary electron density, the primary-to-Maxwellian electron density ratio and the Maxwellian electron temperature. Experiments indicate that the model correctly predicts the variation in plasma ion energy cost for changes in propellant gas (Ar, Kr and Xe), grid transparency to neutral atoms, beam extraction area, discharge voltage, and discharge chamber wall temperature. The model and experiments indicate that thruster performance may be described in terms of only four thruster configuration dependent parameters and two operating parameters. The model also suggests that improved performance should be exhibited by thruster designs which extract a large fraction of the ions produced in the discharge chamber, which have good primary electron and neutral atom containment and which operate at high propellant flow rates.

  19. Development of a Performance Evaluation Tool (MMSOFE) for Detection of Failures with Multiple Model Adaptive Estimation (MMAE)

    DTIC Science & Technology

    1993-12-01

    Calculate the coefficient value which precedes the exponential used to calculate the density. 8. Perform calculations for Bayesian multiple model ...predicted standard deviations. 4. Figure B.8: One figure with two plots relating to the MMAE/ Bayesian parameter estimation: * One plot of the mean...CONTROLS THE CALCULATIONS RELATED TO C MULTIPLE MODEL CALCULATIONS. THE TABLE BELOW GIVES C MORE DETAIL ABOUT WHAT HAPPENS IN THE INDIVIDUAL OUTPUT C

  20. Skylab experiment performance evaluation manual

    NASA Technical Reports Server (NTRS)

    Meyers, J. E.

    1972-01-01

    A series of preparation analyses used for evaluating the performance of the Skylab corollary experiments under preflight, in-flight, and postflight conditions is given. Experiment continegency plan work-around procedure and malfunction analyses are presented in order to assist in making the experiment operationally succesful.

  1. Reliable estimations of extreme low flows by integrating very low flows in the model performance evaluation with a multi-metric framework

    NASA Astrophysics Data System (ADS)

    Pfannerstill, Matthias; Guse, Björn; Fohrer, Nicola

    2014-05-01

    Hydrological models are helpful tools to predict hydrological extremes and to understand the main governing processes for flood and drought events. For reliable predictions of extremes in future simulation such as climate change estimations, a precise representation of high and low flows in hydrological models is required. As a consequence, the hydrological models have to be calibrated accurately to provide reasonable model results for the different phases of the hydrograph simultaneously. For this challenge, the different phases of the hydrograph have to be considered in multi-metric frameworks with appropriate performance metrics. Low flows need to be reproduced together with high flows without neglecting the other phases of the hydrograph. In our study, we highlight the relevance of model evaluation for very low and low flows with separate performance metrics to achieve a satisfying model performance for the low flow prediction together with the overall discharge reproduction. Therefore, we present a multi-metric evaluation framework to identify calibration runs with a precise representation of the hydrograph. In order to consider a fairly balanced evaluation between high and low flow phases, we divided the flow duration curve into segments of high, medium and low flow phases, and additionally into extreme high and extreme low flow phases. The model performance was evaluated stepwise for these segments separately with the root mean square error (RMSE) together with further application of the Nash-Sutcliffe efficiency and the percent bias for the whole discharge. Our results show that this evaluation method leads to an improved selection of model runs with enhanced overall model performance by the refined segmentation of FDC. By combining performance metrics for high flow conditions with low flow conditions, this study demonstrates the challenge of calibrating a model with a satisfactory performance in high and low phases simultaneously. Consequently, we conclude

  2. ESMValTool (v1.0) - a community diagnostic and performance metrics tool for routine evaluation of Earth System Models in CMIP

    NASA Astrophysics Data System (ADS)

    Eyring, V.; Righi, M.; Evaldsson, M.; Lauer, A.; Wenzel, S.; Jones, C.; Anav, A.; Andrews, O.; Cionni, I.; Davin, E. L.; Deser, C.; Ehbrecht, C.; Friedlingstein, P.; Gleckler, P.; Gottschaldt, K.-D.; Hagemann, S.; Juckes, M.; Kindermann, S.; Krasting, J.; Kunert, D.; Levine, R.; Loew, A.; Mäkelä, J.; Martin, G.; Mason, E.; Phillips, A.; Read, S.; Rio, C.; Roehrig, R.; Senftleben, D.; Sterl, A.; van Ulft, L. H.; Walton, J.; Wang, S.; Williams, K. D.

    2015-09-01

    A community diagnostics and performance metrics tool for the evaluation of Earth System Models (ESMs) has been developed that allows for routine comparison of single or multiple models, either against predecessor versions or against observations. The priority of the effort so far has been to target specific scientific themes focusing on selected Essential Climate Variables (ECVs), a range of known systematic biases common to ESMs, such as coupled tropical climate variability, monsoons, Southern Ocean processes, continental dry biases and soil hydrology-climate interactions, as well as atmospheric CO2 budgets, tropospheric and stratospheric ozone, and tropospheric aerosols. The tool is being developed in such a way that additional analyses can easily be added. A set of standard namelists for each scientific topic reproduces specific sets of diagnostics or performance metrics that have demonstrated their importance in ESM evaluation in the peer-reviewed literature. The Earth System Model Evaluation Tool (ESMValTool) is a community effort open to both users and developers encouraging open exchange of diagnostic source code and evaluation results from the CMIP ensemble. This will facilitate and improve ESM evaluation beyond the state-of-the-art and aims at supporting such activities within the Coupled Model Intercomparison Project (CMIP) and at individual modelling centres. Ultimately, we envisage running the ESMValTool alongside the Earth System Grid Federation (ESGF) as part of a more routine evaluation of CMIP model simulations while utilizing observations available in standard formats (obs4MIPs) or provided by the user.

  3. ESMValTool (v1.0) - a community diagnostic and performance metrics tool for routine evaluation of Earth system models in CMIP

    NASA Astrophysics Data System (ADS)

    Eyring, Veronika; Righi, Mattia; Lauer, Axel; Evaldsson, Martin; Wenzel, Sabrina; Jones, Colin; Anav, Alessandro; Andrews, Oliver; Cionni, Irene; Davin, Edouard L.; Deser, Clara; Ehbrecht, Carsten; Friedlingstein, Pierre; Gleckler, Peter; Gottschaldt, Klaus-Dirk; Hagemann, Stefan; Juckes, Martin; Kindermann, Stephan; Krasting, John; Kunert, Dominik; Levine, Richard; Loew, Alexander; Mäkelä, Jarmo; Martin, Gill; Mason, Erik; Phillips, Adam S.; Read, Simon; Rio, Catherine; Roehrig, Romain; Senftleben, Daniel; Sterl, Andreas; van Ulft, Lambertus H.; Walton, Jeremy; Wang, Shiyu; Williams, Keith D.

    2016-05-01

    A community diagnostics and performance metrics tool for the evaluation of Earth system models (ESMs) has been developed that allows for routine comparison of single or multiple models, either against predecessor versions or against observations. The priority of the effort so far has been to target specific scientific themes focusing on selected essential climate variables (ECVs), a range of known systematic biases common to ESMs, such as coupled tropical climate variability, monsoons, Southern Ocean processes, continental dry biases, and soil hydrology-climate interactions, as well as atmospheric CO2 budgets, tropospheric and stratospheric ozone, and tropospheric aerosols. The tool is being developed in such a way that additional analyses can easily be added. A set of standard namelists for each scientific topic reproduces specific sets of diagnostics or performance metrics that have demonstrated their importance in ESM evaluation in the peer-reviewed literature. The Earth System Model Evaluation Tool (ESMValTool) is a community effort open to both users and developers encouraging open exchange of diagnostic source code and evaluation results from the Coupled Model Intercomparison Project (CMIP) ensemble. This will facilitate and improve ESM evaluation beyond the state-of-the-art and aims at supporting such activities within CMIP and at individual modelling centres. Ultimately, we envisage running the ESMValTool alongside the Earth System Grid Federation (ESGF) as part of a more routine evaluation of CMIP model simulations while utilizing observations available in standard formats (obs4MIPs) or provided by the user.

  4. Performance and evaluation of real-time multicomputer control systems

    NASA Technical Reports Server (NTRS)

    Shin, K. G.

    1983-01-01

    New performance measures, detailed examples, modeling of error detection process, performance evaluation of rollback recovery methods, experiments on FTMP, and optimal size of an NMR cluster are discussed.

  5. Composite Load Model Evaluation

    SciTech Connect

    Lu, Ning; Qiao, Hong

    2007-09-30

    The WECC load modeling task force has dedicated its effort in the past few years to develop a composite load model that can represent behaviors of different end-user components. The modeling structure of the composite load model is recommended by the WECC load modeling task force. GE Energy has implemented this composite load model with a new function CMPLDW in its power system simulation software package, PSLF. For the last several years, Bonneville Power Administration (BPA) has taken the lead and collaborated with GE Energy to develop the new composite load model. Pacific Northwest National Laboratory (PNNL) and BPA joint force and conducted the evaluation of the CMPLDW and test its parameter settings to make sure that: • the model initializes properly, • all the parameter settings are functioning, and • the simulation results are as expected. The PNNL effort focused on testing the CMPLDW in a 4-bus system. An exhaustive testing on each parameter setting has been performed to guarantee each setting works. This report is a summary of the PNNL testing results and conclusions.

  6. Evaluation of the performance of four chemical transport models in predicting the aerosol chemical composition in Europe in 2005

    NASA Astrophysics Data System (ADS)

    Prank, Marje; Sofiev, Mikhail; Tsyro, Svetlana; Hendriks, Carlijn; Semeena, Valiyaveetil; Vazhappilly Francis, Xavier; Butler, Tim; Denier van der Gon, Hugo; Friedrich, Rainer; Hendricks, Johannes; Kong, Xin; Lawrence, Mark; Righi, Mattia; Samaras, Zissis; Sausen, Robert; Kukkonen, Jaakko; Sokhi, Ranjeet

    2016-05-01

    Four regional chemistry transport models were applied to simulate the concentration and composition of particulate matter (PM) in Europe for 2005 with horizontal resolution ~ 20 km. The modelled concentrations were compared with the measurements of PM chemical composition by the European Monitoring and Evaluation Programme (EMEP) monitoring network. All models systematically underestimated PM10 and PM2.5 by 10-60 %, depending on the model and the season of the year, when the calculated dry PM mass was compared with the measurements. The average water content at laboratory conditions was estimated between 5 and 20 % for PM2.5 and between 10 and 25 % for PM10. For majority of the PM chemical components, the relative underestimation was smaller than it was for total PM, exceptions being the carbonaceous particles and mineral dust. Some species, such as sea salt and NO3-, were overpredicted by the models. There were notable differences between the models' predictions of the seasonal variations of PM, mainly attributable to different treatments or omission of some source categories and aerosol processes. Benzo(a)pyrene concentrations were overestimated by all the models over the whole year. The study stresses the importance of improving the models' skill in simulating mineral dust and carbonaceous compounds, necessity for high-quality emissions from wildland fires, as well as the need for an explicit consideration of aerosol water content in model-measurement comparison.

  7. Using multi-year data to evaluate performance of one-layer and multi-layer models in snow hydrology: an example from Col De Porte

    NASA Astrophysics Data System (ADS)

    Avanzi, Francesco; De Michele, Carlo; Morin, Samuel; Carmagnola, Carlo Maria; Ghezzi, Antonio; Lejeune, Yves

    2016-04-01

    Snow mass dynamics prediction represents an important task for snow hydrologists, since snow on the ground influences local/global water availability and streamflow timing and amount. Different modeling tools have been formulated for decades to predict snowmelt runoff dynamics and therefore to integrate snow mass dynamics in watershed hydrology modeling. Typical variables of interest include snow depth, snow bulk density, snow water equivalent (SWE) and snowmelt runoff. All these variables have been monitored at several locations worldwide for several decades in order to evaluate model performance. As a result, several multi-year datasets are now available to perform extensive evaluation tests. In this presentation, we report an example of these evaluations by discussing the performance of two models of different complexity in reproducing observed data of snow dynamics at a site in French Alps (Col De Porte, 1325 m AMSL), where 18 continuous-time years of observations are available. We consider Crocus as an example of multi-layer physically-based complex models and HyS (De Michele et al. 2013) as an example of a one-layer temperature-index models. Using multi-year data allows us to compare models performance over long periods of time, thus considering different climatic and snow conditions. Moreover, the use of continuous-time data allows to evaluate models performance at different temporal resolutions. De Michele, C., Avanzi, F., Ghezzi, A., and Jommi, C.: Investigating the dynamics of bulk snow density in dry and wet conditions using a one-dimensional model, The Cryosphere, 7, 433-444, doi:10.5194/tc-7-433-2013, 2013.

  8. Development of System-level Performance Measures for Evaluation of Models of Care for Inflammatory Arthritis in Canada.

    PubMed

    Barber, Claire E H; Marshall, Deborah A; Mosher, Dianne P; Akhavan, Pooneh; Tucker, Lori; Houghton, Kristin; Batthish, Michelle; Levy, Deborah M; Schmeling, Heinrike; Ellsworth, Janet; Tibollo, Heidi; Grant, Sean; Khodyakov, Dmitry; Lacaille, Diane

    2016-03-01

    To develop system-level performance measures for evaluating the care of patients with inflammatory arthritis (IA), including rheumatoid arthritis (RA), psoriatic arthritis, ankylosing spondylitis, and juvenile idiopathic arthritis. This study involved several methodological phases. Over multiple rounds, various participants were asked to help define a set of candidate measurement themes. A systematic search was conducted of existing guidelines and measures. A set of 6 performance measures was defined and presented to 50 people, including patients with IA, rheumatologists, allied health professionals, and researchers using a 3-round, online, modified Delphi process. Participants rated the validity, feasibility, relevance, and likelihood of use of the measures. Measures with median ratings ≥ 7 for validity and relevance were included in the final set. Six performance measures were developed evaluating the following aspects of care, with each measure being applied separately for each type of IA except where specified: waiting times for rheumatology consultation for patients with new onset IA, percentage of patients with IA seen by a rheumatologist, percentage of patients with IA seen in yearly followup by a rheumatologist, percentage of patients with RA treated with a disease-modifying antirheumatic drug (DMARD), time to DMARD therapy in RA, and number of rheumatologists per capita. The first set of system-level performance measures for IA care in Canada has been developed with broad input. The measures focus on timely access to care and initiation of appropriate treatment for patients with IA, and are likely to be of interest to other arthritis care systems internationally.

  9. NCCDS performance model

    NASA Technical Reports Server (NTRS)

    Richmond, Eric; Vallone, Antonio

    1994-01-01

    The NASA/GSFC Network Control Center (NCC) provides communication services between ground facilities and spacecraft missions in near-earth orbit that use the Space Network. The NCC Data System (NCCDS) provides computational support and is expected to be highly utilized by the service requests needed in the future years. A performance model of the NCCDS has been developed to assess the future workload and possible enhancements. The model computes message volumes from mission request profiles and SN resource levels and generates the loads for NCCDS configurations as a function of operational scenarios and processing activities. The model has been calibrated using the results of benchmarks performed on the operational NCCDS facility and used to assess some future SN service request scenarios.

  10. A novel hybrid MCDM model for performance evaluation of research and technology organizations based on BSC approach.

    PubMed

    Varmazyar, Mohsen; Dehghanbaghi, Maryam; Afkhami, Mehdi

    2016-10-01

    Balanced Scorecard (BSC) is a strategic evaluation tool using both financial and non-financial indicators to determine the business performance of organizations or companies. In this paper, a new integrated approach based on the Balanced Scorecard (BSC) and multi-criteria decision making (MCDM) methods are proposed to evaluate the performance of research centers of research and technology organization (RTO) in Iran. Decision-Making Trial and Evaluation Laboratory (DEMATEL) are employed to reflect the interdependencies among BSC perspectives. Then, Analytic Network Process (ANP) is utilized to weight the indices influencing the considered problem. In the next step, we apply four MCDM methods including Additive Ratio Assessment (ARAS), Complex Proportional Assessment (COPRAS), Multi-Objective Optimization by Ratio Analysis (MOORA), and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) for ranking of alternatives. Finally, the utility interval technique is applied to combine the ranking results of MCDM methods. Weighted utility intervals are computed by constructing a correlation matrix between the ranking methods. A real case is presented to show the efficacy of the proposed approach.

  11. ATR performance modeling concepts

    NASA Astrophysics Data System (ADS)

    Ross, Timothy D.; Baker, Hyatt B.; Nolan, Adam R.; McGinnis, Ryan E.; Paulson, Christopher R.

    2016-05-01

    Performance models are needed for automatic target recognition (ATR) development and use. ATRs consume sensor data and produce decisions about the scene observed. ATR performance models (APMs) on the other hand consume operating conditions (OCs) and produce probabilities about what the ATR will produce. APMs are needed for many modeling roles of many kinds of ATRs (each with different sensing modality and exploitation functionality combinations); moreover, there are different approaches to constructing the APMs. Therefore, although many APMs have been developed, there is rarely one that fits a particular need. Clarified APM concepts may allow us to recognize new uses of existing APMs and identify new APM technologies and components that better support coverage of the needed APMs. The concepts begin with thinking of ATRs as mapping OCs of the real scene (including the sensor data) to reports. An APM is then a mapping from explicit quantized OCs (represented with less resolution than the real OCs) and latent OC distributions to report distributions. The roles of APMs can be distinguished by the explicit OCs they consume. APMs used in simulations consume the true state that the ATR is attempting to report. APMs used online with the exploitation consume the sensor signal and derivatives, such as match scores. APMs used in sensor management consume neither of those, but estimate performance from other OCs. This paper will summarize the major building blocks for APMs, including knowledge sources, OC models, look-up tables, analytical and learned mappings, and tools for signal synthesis and exploitation.

  12. Application of 2D numerical model to unsteady performance evaluation of vertical-axis tidal current turbine

    NASA Astrophysics Data System (ADS)

    Liu, Zhen; Qu, Hengliang; Shi, Hongda; Hu, Gexing; Hyun, Beom-Soo

    2016-12-01

    Tidal current energy is renewable and sustainable, which is a promising alternative energy resource for the future electricity supply. The straight-bladed vertical-axis turbine is regarded as a useful tool to capture the tidal current energy especially under low-speed conditions. A 2D unsteady numerical model based on Ansys-Fluent 12.0 is established to conduct the numerical simulation, which is validated by the corresponding experimental data. For the unsteady calculations, the SST model, 2×105 and 0.01 s are selected as the proper turbulence model, mesh number, and time step, respectively. Detailed contours of the velocity distributions around the rotor blade foils have been provided for a flow field analysis. The tip speed ratio (TSR) determines the azimuth angle of the appearance of the torque peak, which occurs once for a blade in a single revolution. It is also found that simply increasing the incident flow velocity could not improve the turbine performance accordingly. The peaks of the averaged power and torque coefficients appear at TSRs of 2.1 and 1.8, respectively. Furthermore, several shapes of the duct augmentation are proposed to improve the turbine performance by contracting the flow path gradually from the open mouth of the duct to the rotor. The duct augmentation can significantly enhance the power and torque output. Furthermore, the elliptic shape enables the best performance of the turbine. The numerical results prove the capability of the present 2D model for the unsteady hydrodynamics and an operating performance analysis of the vertical tidal stream turbine.

  13. EVALUATION OF THE COMMUNITY MULTISCALE AIR QUALITY (CMAQ) MODEL VERSION 4.5: UNCERTAINTIES AND SENSITIVITIES IMPACTING MODEL PERFORMANCE: PART II - PARTICULATE MATTER

    EPA Science Inventory

    This paper presents an analysis of the CMAQ v4.5 model performance for particulate matter and its chemical components for the simulated year 2001. This is part two is two part series of papers that examines the model performance of CMAQ v4.5.

  14. EVALUATION OF THE COMMUNITY MULTISCALE AIR QUALITY (CMAQ) MODEL VERSION 4.5: UNCERTAINTIES AND SENSITIVITIES IMPACTING MODEL PERFORMANCE: PART II - PARTICULATE MATTER

    EPA Science Inventory

    This paper presents an analysis of the CMAQ v4.5 model performance for particulate matter and its chemical components for the simulated year 2001. This is part two is two part series of papers that examines the model performance of CMAQ v4.5.

  15. Performance Evaluation of K-DEMO Cable-in-conduit Conductors Using the Florida Electro-Mechanical Cable Model

    SciTech Connect

    Zhai, Yuhu

    2013-07-16

    The United States ITER Project Office (USIPO) is responsible for design of the Toroidal Field (TF) insert coil, which will allow validation of the performance of significant lengths of the conductors to be used in the full scale TF coils in relevant conditions of field, current density and mechanical strain. The Japan Atomic Energy Agency (JAEA) will build the TF insert which will be tested at the Central Solenoid Model Coil (CSMC) Test facility at JAEA, Naka, Japan. Three dimensional mathematical model of TF Insert was created based on the initial design geometry data, and included the following features: orthotropic material properties of superconductor material and insulation; external magnetic field from CSMC, temperature dependent properties of the materials; pre-compression and plastic deformation in lap joint. Major geometrical characteristics of the design were preserved including cable jacket and insulation shape, mandrel outline, and support clamps and spacers. The model is capable of performing coupled structural, thermal, and electromagnetic analysis using ANSYS. Numerical simulations were performed for room temperature conditions; cool down to 4K, and the operating regime with 68kA current at 11.8 Tesla background field. Numerical simulations led to the final design of the coil producing the required strain levels on the cable, while simultaneously satisfying the ITER magnet structural design criteria.

  16. Evaluating judge performance in sport.

    PubMed

    Looney, Marilyn A

    2004-01-01

    Many sports, such as, gymnastics, diving, ski jumping, and figure skating, use judges' scores to determine the winner of a competition. These judges use some type of rating scale when judging performances (e.g., figure skating: 0.0 - 6.0). Sport governing bodies have the responsibility of setting and enforcing quality control parameters for judge performance. Given the judging scandals in figure skating at the 1998 and 2002 Olympics, judge performance in sport is receiving greater scrutiny. The purpose of this article is to illustrate how results from Rasch analyses can be used to provide in-depth feedback to judges about their scoring patterns. Nine judges' scores for 20 pairs of figure skaters who competed at the 2002 Winter Olympics were analyzed using a four-faceted (skater pair ability, skating aspect difficulty, program difficulty, and judge severity) Rasch rating scale model that was not common to all judges. Fit statistics, the logical ordering of skating aspects, skating programs, and separation indices all indicated a good fit of the data to the model. The type of feedback that can be given to judges about their scoring pattern was illustrated for one judge (USA) whose performance was flagged as being unpredictable. Feedback included a detailed description of how the rating scale was used; for example, 10% of all marks given by the American judge were unexpected by the model (Z > |2|). Three figures illustrated differences between the judge's observed and expected marks arranged according to the pairs' skating order and final placement in the competition. Scores which may represent "nationalistic bias" or a skating order influence were flagged by looking at these figures. If sport governing bodies wish to improve the performance of their judges, they need to employ methods that monitor the internal consistency of each judge as a many-facet Rasch analysis does.

  17. A new performance evaluation tool

    SciTech Connect

    Kindl, F.H.

    1996-12-31

    The paper describes a Steam Cycle Diagnostic Program (SCDP), that has been specifically designed to respond to the increasing need of electric power generators for periodic performance monitoring, and quick identification of the causes for any observed increase in fuel consumption. There is a description of program objectives, modeling and test data inputs, results, underlying program logic, validation of program accuracy by comparison with acceptance test quality data, and examples of program usage.

  18. Performance evaluation of ant colony optimization-based solution strategies on the mixed-model assembly line balancing problem

    NASA Astrophysics Data System (ADS)

    Akpinar, Sener; Mirac Bayhan, G.

    2014-06-01

    The aim of this article is to compare the performances of iterative ant colony optimization (ACO)-based solution strategies on a mixed-model assembly line balancing problem of type II (MMALBP-II) by addressing some particular features of real-world assembly line balancing problems such as parallel workstations and zoning constraints. To solve the problem, where the objective is to minimize the cycle time (i.e. maximize the production rate) for a predefined number of workstations in an existing assembly line, two ACO-based approaches which differ in the mission assigned to artificial ants are used. Furthermore, each ACO-based approach is conducted with two different pheromone release strategies: global and local pheromone updating rules. The four ACO-based approaches are used for solving 20 representative MMALBP-II to compare their performance in terms of computational time and solution quality. Detailed comparison results are presented.

  19. Performance Evaluation of Nano-JASMINE

    NASA Astrophysics Data System (ADS)

    Hatsutori, Y.; Kobayashi, Y.; Gouda, N.; Yano, T.; Murooka, J.; Niwa, Y.; Yamada, Y.

    We report the results of performance evaluation of the first Japanese astrometry satellite, Nano-JASMINE. It is a very small satellite and weighs only 35 kg. It aims to carry out astrometry measurement of nearby bright stars (z ≤ 7.5 mag) with an accuracy of 3 milli-arcseconds. Nano-JASMINE will be launched by Cyclone-4 rocket in August 2011 from Brazil. The current status is in the process of evaluating the performances. A series of performance tests and numerical analysis were conducted. As a result, the engineering model (EM) of the telescope was measured to be achieving a diffraction-limited performance and confirmed that it has enough performance for scientific astrometry.

  20. Performance Evaluation of Nano-JASMINE

    NASA Astrophysics Data System (ADS)

    Hatsutori, Y.; Kobayashi, Y.; Gouda, N.; Yano, T.; Murooka, J.; Niwa, Y.; Yamada, Y.

    2011-02-01

    We report the results of performance evaluation of the first Japanese astrometry satellite, Nano-JASMINE. It is a very small satellite and weighs only 35 kg. It aims to carry out astrometry measurement of nearby bright stars (z ≤ 7.5 mag) with an accuracy of 3 milli-arcseconds. Nano-JASMINE will be launched by Cyclone-4 rocket in August 2011 from Brazil. The current status is in the process of evaluating the performances. A series of performance tests and numerical analysis were conducted. As a result, the engineering model (EM) of the telescope was measured to be achieving a diffraction-limited performance and confirmed that it has enough performance for scientific astrometry.

  1. Performance evaluation and modeling of a conformal filter (CF) based real-time standoff hazardous material detection sensor

    NASA Astrophysics Data System (ADS)

    Nelson, Matthew P.; Tazik, Shawna K.; Bangalore, Arjun S.; Treado, Patrick J.; Klem, Ethan; Temple, Dorota

    2017-05-01

    Hyperspectral imaging (HSI) systems can provide detection and identification of a variety of targets in the presence of complex backgrounds. However, current generation sensors are typically large, costly to field, do not usually operate in real time and have limited sensitivity and specificity. Despite these shortcomings, HSI-based intelligence has proven to be a valuable tool, thus resulting in increased demand for this type of technology. By moving the next generation of HSI technology into a more adaptive configuration, and a smaller and more cost effective form factor, HSI technologies can help maintain a competitive advantage for the U.S. armed forces as well as local, state and federal law enforcement agencies. Operating near the physical limits of HSI system capability is often necessary and very challenging, but is often enabled by rigorous modeling of detection performance. Specific performance envelopes we consistently strive to improve include: operating under low signal to background conditions; at higher and higher frame rates; and under less than ideal motion control scenarios. An adaptable, low cost, low footprint, standoff sensor architecture we have been maturing includes the use of conformal liquid crystal tunable filters (LCTFs). These Conformal Filters (CFs) are electro-optically tunable, multivariate HSI spectrometers that, when combined with Dual Polarization (DP) optics, produce optimized spectral passbands on demand, which can readily be reconfigured, to discriminate targets from complex backgrounds in real-time. With DARPA support, ChemImage Sensor Systems (CISS™) in collaboration with Research Triangle Institute (RTI) International are developing a novel, real-time, adaptable, compressive sensing short-wave infrared (SWIR) hyperspectral imaging technology called the Reconfigurable Conformal Imaging Sensor (RCIS) based on DP-CF technology. RCIS will address many shortcomings of current generation systems and offer improvements in

  2. METAPHOR (version 1): Users guide. [performability modeling

    NASA Technical Reports Server (NTRS)

    Furchtgott, D. G.

    1979-01-01

    General information concerning METAPHOR, an interactive software package to facilitate performability modeling and evaluation, is presented. Example systems are studied and their performabilities are calculated. Each available METAPHOR command and array generator is described. Complete METAPHOR sessions are included.

  3. Small wind turbine performance evaluation using field test data and a coupled aero-electro-mechanical model

    NASA Astrophysics Data System (ADS)

    Wallace, Brian D.

    A series of field tests and theoretical analyses were performed on various wind turbine rotor designs at two Penn State residential-scale wind-electric facilities. This work involved the prediction and experimental measurement of the electrical and aerodynamic performance of three wind turbines; a 3 kW rated Whisper 175, 2.4 kW rated Skystream 3.7, and the Penn State designed Carolus wind turbine. Both the Skystream and Whisper 175 wind turbines are OEM blades which were originally installed at the facilities. The Carolus rotor is a carbon-fiber composite 2-bladed machine, designed and assembled at Penn State, with the intent of replacing the Whisper 175 rotor at the off-grid system. Rotor aerodynamic performance is modeled using WT_Perf, a National Renewable Energy Laboratory developed Blade Element Momentum theory based performance prediction code. Steady-state power curves are predicted by coupling experimentally determined electrical characteristics with the aerodynamic performance of the rotor simulated with WT_Perf. A dynamometer test stand is used to establish the electromechanical efficiencies of the wind-electric system generator. Through the coupling of WT_Perf and dynamometer test results, an aero-electro-mechanical analysis procedure is developed and provides accurate predictions of wind system performance. The analysis of three different wind turbines gives a comprehensive assessment of the capability of the field test facilities and the accuracy of aero-electro-mechanical analysis procedures. Results from this study show that the Carolus and Whisper 175 rotors are running at higher tip-speed ratios than are optimum for power production. The aero-electro-mechanical analysis predicted the high operating tip-speed ratios of the rotors and was accurate at predicting output power for the systems. It is shown that the wind turbines operate at high tip-speeds because of a miss-match between the aerodynamic drive torque and the operating torque of the wind

  4. Evaluating the Performance of the CPTEC-INPE/FCT-UNESP Troposphere Dynamic Model Using the VRS Concept

    NASA Astrophysics Data System (ADS)

    Alves, D. B.; Dalbelo, L. F.; Monico, J. F.; Sapucci, L. F.

    2007-05-01

    Nowadays, the use of Zenithal Tropospheric Delay (ZTD) prediction from Numeric Weather Prediction (NWP) models is a good alternative to minimize the effects of the troposphere in the radio frequency signs for real time and/or pos-processed applications. This process is denominated here after ZTD dynamic modeling. In Brazil, the procedure used to compute the ZTD by the NWP model was jointly developed by researchers from UNESP (São Paulo State University) and CPTEC (Center for Weather Forecasting and Climate Studies) of the INPE (National Institute for Space Research). The ZTD values are provided for all South America twice a day with predictions for a period of 66 hours. The database and the quality analysis are available by CPTEC-INPE in http:satelite.cptec.inpe.br/htmldocs/ztd/zenital.htm. In order to test the performance of the ZTD dynamic modeling in positioning applications, some experiments were carried out. Besides, the results obtained with dynamic modeling were compared with those obtained by Hopfield empirical model. These two tropospheric models were used to generate a VRS (Virtual Reference Station). In the VRS concept developed in this research, a reference station is generated near the user using data provided by a reference network station and atmospheric models. Therefore, the VRS data are not provided by a real receiver. But, the idea is that the VRS data resemble as much as possible a real receiver data at the same location. Therefore, the user has the possibility of using the VRS as if it were a real reference station in your proximities, and to accomplish the relative positioning with a single frequency receiver. This method was implemented in an software which has been developed at UNESP. In order to test the discussed method it was accomplished two experiments using data from two different networks: (a) Brazilian Continuous GPS Network (RBMC) and some extra stations; (b) GPS Active Network of West of São Paulo State. Using the first network

  5. Towards Fully Coupled Atmosphere-Hydrology Model Systems: Recent Developments and Performance Evaluation For Different Climate Regions

    NASA Astrophysics Data System (ADS)

    Kunstmann, Harald; Fersch, Benjamin; Rummler, Thomas; Wagner, Sven; Arnault, Joel; Senatore, Alfonso; Gochis, David

    2015-04-01

    Limitations in the adequate representation of terrestrial hydrologic processes controlling the land-atmosphere coupling are assumed to be a significant factor currently limiting prediction skills of regional atmospheric models. The necessity for more comprehensive process descriptions accounting for the interdependencies between water- and energy fluxes at the compartmental interfaces are driving recent developments in hydrometeorological modeling towards more sophisticated treatment of terrestrial hydrologic processes. It is particularly the lateral surface and subsurface water fluxes that are neglected in standard regional atmospheric models. Current developments in enhanced lateral hydrological process descriptions in the WRF model system will be presented. Based on WRF and WRF-Hydro, new modules and concepts for integrating the saturated zone by a 2-dim groundwater scheme and coupling approaches to the unsaturated zone will be presented. The fully coupled model system allows to model the complete regional water cycle, from the top of the atmosphere, via the boundary layer, the land surface, the unsaturated zone and the saturated zone till the flow in the river beds. With this increasing complexity, that also allows to describe the complex interaction of the regional water cycle on different spatial and temporal scales, the reliability and predictability of model simulations can only be shown, if performance is tested for a variety of hydrological variables for different climatological environments. We will show results of fully coupled simulations for the regions of sempiternal humid Southern Bavaria/Germany (rivers Isar and Ammer) and semiarid to subhumid Westafrica (river Sissilli). In both regions, in addition to streamflow measurements, also the validation of heat fluxes is possible via Eddy-Covariance stations within hydrometeorological testbeds. In the German Isar/Ammer region, e.g., we apply the extended WRF-Hydro modeling system in 3km atmospheric- grid

  6. How do current irrigation practices perform? Evaluation of different irrigation scheduling approaches based on experiements and crop model simulations

    NASA Astrophysics Data System (ADS)

    Seidel, Sabine J.; Werisch, Stefan; Barfus, Klemens; Wagner, Michael; Schütze, Niels; Laber, Hermann

    2014-05-01

    The increasing worldwide water scarcity, costs and negative off-site effects of irrigation are leading to the necessity of developing methods of irrigation that increase water productivity. Various approaches are available for irrigation scheduling. Traditionally schedules are calculated based on soil water balance (SWB) calculations using some measure of reference evaporation and empirical crop coeffcients. These crop-specific coefficients are provided by the FAO but are also available for different regions (e.g. Germany). The approach is simple but there are several inaccuracies due to simplifications and limitations such as poor transferability. Crop growth models - which simulate the main physiological plant processes through a set of assumptions and calibration parameter - are widely used to support decision making, but also for yield gap or scenario analyses. One major advantage of mechanistic models compared to empirical approaches is their spatial and temporal transferability. Irrigation scheduling can also be based on measurements of soil water tension which is closely related to plant stress. Advantages of precise and easy measurements are able to be automated but face difficulties of finding the place where to probe especially in heterogenous soils. In this study, a two-year field experiment was used to extensively evaluate the three mentioned irrigation scheduling approaches regarding their efficiency on irrigation water application with the aim to promote better agronomic practices in irrigated horticulture. To evaluate the tested irrigation scheduling approaches, an extensive plant and soil water data collection was used to precisely calibrate the mechanistic crop model Daisy. The experiment was conducted with white cabbage (Brassica oleracea L.) on a sandy loamy field in 2012/13 near Dresden, Germany. Hereby, three irrigation scheduling approaches were tested: (i) two schedules were estimated based on SWB calculations using different crop

  7. Evaluating the performance of CMIP3 and CMIP5 global climate models over the north-east Atlantic region

    NASA Astrophysics Data System (ADS)

    Perez, Jorge; Menendez, Melisa; Mendez, Fernando J.; Losada, Inigo J.

    2014-11-01

    One of the main sources of uncertainty in estimating climate projections affected by global warming is the choice of the global climate model (GCM). The aim of this study is to evaluate the skill of GCMs from CMIP3 and CMIP5 databases in the north-east Atlantic Ocean region. It is well known that the seasonal and interannual variability of surface inland variables (e.g. precipitation and snow) and ocean variables (e.g. wave height and storm surge) are linked to the atmospheric circulation patterns. Thus, an automatic synoptic classification, based on weather types, has been used to assess whether GCMs are able to reproduce spatial patterns and climate variability. Three important factors have been analyzed: the skill of GCMs to reproduce the synoptic situations, the skill of GCMs to reproduce the historical inter-annual variability and the consistency of GCMs experiments during twenty-first century projections. The results of this analysis indicate that the most skilled GCMs in the study region are UKMO-HadGEM2, ECHAM5/MPI-OM and MIROC3.2(hires) for CMIP3 scenarios and ACCESS1.0, EC-EARTH, HadGEM2-CC, HadGEM2-ES and CMCC-CM for CMIP5 scenarios. These models are therefore recommended for the estimation of future regional multi-model projections of surface variables driven by the atmospheric circulation in the north-east Atlantic Ocean region.

  8. A Discrete Event Simulation Model for Evaluating the Performances of an M/G/C/C State Dependent Queuing System

    PubMed Central

    Khalid, Ruzelan; M. Nawawi, Mohd Kamal; Kawsar, Luthful A.; Ghani, Noraida A.; Kamil, Anton A.; Mustafa, Adli

    2013-01-01

    M/G/C/C state dependent queuing networks consider service rates as a function of the number of residing entities (e.g., pedestrians, vehicles, and products). However, modeling such dynamic rates is not supported in modern Discrete Simulation System (DES) software. We designed an approach to cater this limitation and used it to construct the M/G/C/C state-dependent queuing model in Arena software. Using the model, we have evaluated and analyzed the impacts of various arrival rates to the throughput, the blocking probability, the expected service time and the expected number of entities in a complex network topology. Results indicated that there is a range of arrival rates for each network where the simulation results fluctuate drastically across replications and this causes the simulation results and analytical results exhibit discrepancies. Detail results that show how tally the simulation results and the analytical results in both abstract and graphical forms and some scientific justifications for these have been documented and discussed. PMID:23560037

  9. Numerical Prediction of Cold Season Fog Events over Complex Terrain: the Performance of the WRF Model During MATERHORN-Fog and Early Evaluation

    NASA Astrophysics Data System (ADS)

    Pu, Zhaoxia; Chachere, Catherine N.; Hoch, Sebastian W.; Pardyjak, Eric; Gultepe, Ismail

    2016-09-01

    A field campaign to study cold season fog in complex terrain was conducted as a component of the Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) Program from 07 January to 01 February 2015 in Salt Lake City and Heber City, Utah, United States. To support the field campaign, an advanced research version of the Weather Research and Forecasting (WRF) model was used to produce real-time forecasts and model evaluation. This paper summarizes the model performance and preliminary evaluation of the model against the observations. Results indicate that accurately forecasting fog is challenging for the WRF model, which produces large errors in the near-surface variables, such as relative humidity, temperature, and wind fields in the model forecasts. Specifically, compared with observations, the WRF model overpredicted fog events with extended duration in Salt Lake City because it produced higher moisture, lower wind speeds, and colder temperatures near the surface. In contrast, the WRF model missed all fog events in Heber City, as it reproduced lower moisture, higher wind speeds, and warmer temperatures against observations at the near-surface level. The inability of the model to produce proper levels of near-surface atmospheric conditions under fog conditions reflects uncertainties in model physical parameterizations, such as the surface layer, boundary layer, and microphysical schemes.

  10. Evaluation of the imputation performance of the program IMPUTE in an admixed sample from Mexico City using several model designs

    PubMed Central

    2012-01-01

    Background We explored the imputation performance of the program IMPUTE in an admixed sample from Mexico City. The following issues were evaluated: (a) the impact of different reference panels (HapMap vs. 1000 Genomes) on imputation; (b) potential differences in imputation performance between single-step vs. two-step (phasing and imputation) approaches; (c) the effect of different INFO score thresholds on imputation performance and (d) imputation performance in common vs. rare markers. Methods The sample from Mexico City comprised 1,310 individuals genotyped with the Affymetrix 5.0 array. We randomly masked 5% of the markers directly genotyped on chromosome 12 (n = 1,046) and compared the imputed genotypes with the microarray genotype calls. Imputation was carried out with the program IMPUTE. The concordance rates between the imputed and observed genotypes were used as a measure of imputation accuracy and the proportion of non-missing genotypes as a measure of imputation efficacy. Results The single-step imputation approach produced slightly higher concordance rates than the two-step strategy (99.1% vs. 98.4% when using the HapMap phase II combined panel), but at the expense of a lower proportion of non-missing genotypes (85.5% vs. 90.1%). The 1,000 Genomes reference sample produced similar concordance rates to the HapMap phase II panel (98.4% for both datasets, using the two-step strategy). However, the 1000 Genomes reference sample increased substantially the proportion of non-missing genotypes (94.7% vs. 90.1%). Rare variants (<1%) had lower imputation accuracy and efficacy than common markers. Conclusions The program IMPUTE had an excellent imputation performance for common alleles in an admixed sample from Mexico City, which has primarily Native American (62%) and European (33%) contributions. Genotype concordances were higher than 98.4% using all the imputation strategies, in spite of the fact that no Native American samples are present in the HapMap and

  11. Prospective safety performance evaluation on construction sites.

    PubMed

    Wu, Xianguo; Liu, Qian; Zhang, Limao; Skibniewski, Miroslaw J; Wang, Yanhong

    2015-05-01

    This paper presents a systematic Structural Equation Modeling (SEM) based approach for Prospective Safety Performance Evaluation (PSPE) on construction sites, with causal relationships and interactions between enablers and the goals of PSPE taken into account. According to a sample of 450 valid questionnaire surveys from 30 Chinese construction enterprises, a SEM model with 26 items included for PSPE in the context of Chinese construction industry is established and then verified through the goodness-of-fit test. Three typical types of construction enterprises, namely the state-owned enterprise, private enterprise and Sino-foreign joint venture, are selected as samples to measure the level of safety performance given the enterprise scale, ownership and business strategy are different. Results provide a full understanding of safety performance practice in the construction industry, and indicate that the level of overall safety performance situation on working sites is rated at least a level of III (Fair) or above. This phenomenon can be explained that the construction industry has gradually matured with the norms, and construction enterprises should improve the level of safety performance as not to be eliminated from the government-led construction industry. The differences existing in the safety performance practice regarding different construction enterprise categories are compared and analyzed according to evaluation results. This research provides insights into cause-effect relationships among safety performance factors and goals, which, in turn, can facilitate the improvement of high safety performance in the construction industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Evaluation of SUNY satellite-to-irradiance model performance using ECMWF GEMS daily aerosol optical depth reanalysis data

    NASA Astrophysics Data System (ADS)

    Itterly, Kyle F.

    The current version of the State University of New York (SUNY) radiative transfer model (RTM) uses climatological monthly averages derived from a National Renewable Energy Labs (NREL) gridded dataset to parameterize aerosol optical depth (AOD), water vapor and ozone. This is mostly due to the limited availability of high spatially and temporally resolved observations. Several global chemical transport models are analyzed and compared in depth to determine which daily AOD dataset should be implemented into the SUNY Model. After thorough comparison, the chemical transport model chosen was the Global and regional Earth-system Monitoring using satellite and in-situ data (GEMS) model developed by the European Center for Medium Range Weather Forecasts (ECMWF). Using daily AOD values instead of monthly climatological values, the SUNY Model better captures events of extreme aerosol loadings, which greatly improves the accuracy in calculations of direct normal irradiance (DNI) and to a lesser extent, global horizontal irradiance (GHI). In clear-sky conditions with the sun directly overhead, a change in AOD from 0.1 to 0.5 is found to cause a 55% (20%) decrease in DNI (GHI) for Desert Rock, Nevada in January. A calibration scheme is applied to the daily GEMS AOD reanalysis data. For each site, the monthly means of the GEMS daily AOD are corrected by a factor to match the currently used monthly climatological AOD in order to avoid large errors caused by changing the magnitude of the monthly average AOD. The performance of the SUNY model improved significantly for many of the stations analyzed in this work after applying the daily-calibrated GEMS AOD. The Root Mean Squared Error (RMSE) was the most notable statistical improvement, which measures the model’s precision compared to the observed measurements from a ground station, and many other statistical improvements are also evident. All 7 SURFRAD locations showed improvements in DNI RMSE after using the calibrated GEMS

  13. Evaluating Performance Portability of OpenACC

    SciTech Connect

    Sabne, Amit J; Sakdhnagool, Putt; Lee, Seyong; Vetter, Jeffrey S

    2015-01-01

    Accelerator-based heterogeneous computing is gaining momentum in High Performance Computing arena. However, the increased complexity of the accelerator architectures demands more generic, high-level programming models. OpenACC is one such attempt to tackle the problem. While the abstraction endowed by OpenACC offers productivity, it raises questions on its portability. This paper evaluates the performance portability obtained by OpenACC on twelve OpenACC programs on NVIDIA CUDA, AMD GCN, and Intel MIC architectures. We study the effects of various compiler optimizations and OpenACC program settings on these architectures to provide insights into the achieved performance portability.

  14. Presentation of the EURODELTA III intercomparison exercise - evaluation of the chemistry transport models' performance on criteria pollutants and joint analysis with meteorology

    NASA Astrophysics Data System (ADS)

    Bessagnet, Bertrand; Pirovano, Guido; Mircea, Mihaela; Cuvelier, Cornelius; Aulinger, Armin; Calori, Giuseppe; Ciarelli, Giancarlo; Manders, Astrid; Stern, Rainer; Tsyro, Svetlana; García Vivanco, Marta; Thunis, Philippe; Pay, Maria-Teresa; Colette, Augustin; Couvidat, Florian; Meleux, Frédérik; Rouïl, Laurence; Ung, Anthony; Aksoyoglu, Sebnem; María Baldasano, José; Bieser, Johannes; Briganti, Gino; Cappelletti, Andrea; D'Isidoro, Massimo; Finardi, Sandro; Kranenburg, Richard; Silibello, Camillo; Carnevale, Claudio; Aas, Wenche; Dupont, Jean-Charles; Fagerli, Hilde; Gonzalez, Lucia; Menut, Laurent; Prévôt, André S. H.; Roberts, Pete; White, Les

    2016-10-01

    The EURODELTA III exercise has facilitated a comprehensive intercomparison and evaluation of chemistry transport model performances. Participating models performed calculations for four 1-month periods in different seasons in the years 2006 to 2009, allowing the influence of different meteorological conditions on model performances to be evaluated. The exercise was performed with strict requirements for the input data, with few exceptions. As a consequence, most of differences in the outputs will be attributed to the differences in model formulations of chemical and physical processes. The models were evaluated mainly for background rural stations in Europe. The performance was assessed in terms of bias, root mean square error and correlation with respect to the concentrations of air pollutants (NO2, O3, SO2, PM10 and PM2.5), as well as key meteorological variables. Though most of meteorological parameters were prescribed, some variables like the planetary boundary layer (PBL) height and the vertical diffusion coefficient were derived in the model preprocessors and can partly explain the spread in model results. In general, the daytime PBL height is underestimated by all models. The largest variability of predicted PBL is observed over the ocean and seas. For ozone, this study shows the importance of proper boundary conditions for accurate model calculations and then on the regime of the gas and particle chemistry. The models show similar and quite good performance for nitrogen dioxide, whereas they struggle to accurately reproduce measured sulfur dioxide concentrations (for which the agreement with observations is the poorest). In general, the models provide a close-to-observations map of particulate matter (PM2.5 and PM10) concentrations over Europe rather with correlations in the range 0.4-0.7 and a systematic underestimation reaching -10 µg m-3 for PM10. The highest concentrations are much more underestimated, particularly in wintertime. Further evaluation of

  15. Applying Human-performance Models to Designing and Evaluating Nuclear Power Plants: Review Guidance and Technical Basis

    SciTech Connect

    O'Hara, J.M.

    2009-11-30

    Human performance models (HPMs) are simulations of human behavior with which we can predict human performance. Designers use them to support their human factors engineering (HFE) programs for a wide range of complex systems, including commercial nuclear power plants. Applicants to U.S. Nuclear Regulatory Commission (NRC) can use HPMs for design certifications, operating licenses, and license amendments. In the context of nuclear-plant safety, it is important to assure that HPMs are verified and validated, and their usage is consistent with their intended purpose. Using HPMs improperly may generate misleading or incorrect information, entailing safety concerns. The objective of this research was to develop guidance to support the NRC staff's reviews of an applicant's use of HPMs in an HFE program. The guidance is divided into three topical areas: (1) HPM Verification, (2) HPM Validation, and (3) User Interface Verification. Following this guidance will help ensure the benefits of HPMs are achieved in a technically sound, defensible manner. During the course of developing this guidance, I identified several issues that could not be addressed; they also are discussed.

  16. Guidelines for Model Evaluation.

    DTIC Science & Technology

    1979-01-01

    by a decisionmaker. The full-scale evaluation of a complex model can be an expensive, time- consuming effort requiring diverse talents and skills...relative to PIES, were documented in a report to the Congress. 2/ An important side- effect of that document was that a foundation was laid for model...while for model evaluation there are no generally accepted standards or methods. Hence, GAO perceives the need to expand upon the lessons learned in

  17. SEASAT SAR performance evaluation study

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The performance of the SEASAT synthetic aperture radar (SAR) sensor was evaluated using data processed by the MDA digital processor. Two particular aspects are considered the location accuracy of image data, and the calibration of the measured backscatter amplitude of a set of corner reflectors. The image location accuracy was assessed by selecting identifiable targets in several scenes, converting their image location to UTM coordinates, and comparing the results to map sheets. The error standard deviation is measured to be approximately 30 meters. The amplitude was calibrated by measuring the responses of the Goldstone corner reflector array and comparing the results to theoretical values. A linear regression of the measured against theoretical values results in a slope of 0.954 with a correlation coefficient of 0.970.

  18. Climate models and model evaluation

    SciTech Connect

    Gates, W.L.

    1994-12-31

    This brief overview addresses aspects of the nature, uses, evaluation and limitations of climate models. A comprehensive global modeling capability has been achieved only for the physical climate system, which is characterized by processes that serve to transport and exchange momentum, heat and moisture within and between the atmosphere, ocean and land surface. The fundamental aim of climate modeling, and the justification for the use of climate models, is the need to achieve a quantitative understanding of the operation of the climate system and to exploit any potential predictability that may exist.

  19. Technical note: Fu-Liou-Gu and Corti-Peter model performance evaluation for radiative retrievals from cirrus clouds

    NASA Astrophysics Data System (ADS)

    Lolli, Simone; Campbell, James R.; Lewis, Jasper R.; Gu, Yu; Welton, Ellsworth J.

    2017-06-01

    We compare, for the first time, the performance of a simplified atmospheric radiative transfer algorithm package, the Corti-Peter (CP) model, versus the more complex Fu-Liou-Gu (FLG) model, for resolving top-of-the-atmosphere radiative forcing characteristics from single-layer cirrus clouds obtained from the NASA Micro-Pulse Lidar Network database in 2010 and 2011 at Singapore and in Greenbelt, Maryland, USA, in 2012. Specifically, CP simplifies calculation of both clear-sky longwave and shortwave radiation through regression analysis applied to radiative calculations, which contributes significantly to differences between the two. The results of the intercomparison show that differences in annual net top-of-the-atmosphere (TOA) cloud radiative forcing can reach 65 %. This is particularly true when land surface temperatures are warmer than 288 K, where the CP regression analysis becomes less accurate. CP proves useful for first-order estimates of TOA cirrus cloud forcing, but may not be suitable for quantitative accuracy, including the absolute sign of cirrus cloud daytime TOA forcing that can readily oscillate around zero globally.

  20. Quantitative performance of advanced resolution recovery strategies on SPECT images: evaluation with use of digital phantom models.

    PubMed

    Onishi, Hideo; Motomura, Nobutoku; Fujino, Koichi; Natsume, Takahiro; Haramoto, Yasuhiro

    2013-01-01

    Several resolution recovery (RR) methods have been developed. This study was aimed to validate the following performance of the advanced RR methods: Evolution, Astonish, Flash3D, and 3D-OSEM. We compared the advanced RR method with filtered back projection (FBP) and standard order-subset expectation maximization (OSEM) using resolution (RES), cylinder/sphere (CYS), and myocardial (MYD) digital phantoms. The RES phantom was placed in three spheres. Sixteen spheres (hot and cold) were then placed in a concentric configuration (diameter: 96-9.6 mm) inside the CYS phantom. The MYD phantom was created by computer simulation with the use of an electron γ-shower 4 (EGS4) and it included two left ventricular defects in the myocardium. The performance was evaluated at source-to-detector distances (R-distance) of 166, 200, and 250 mm with reconstruction parameters (product of subset and iteration: SI) with use of the resolution recovery factor, count recovery, normalized mean square error (NMSE), and %CV. According to increased SI updates, the value of the FWHM decreased, and the effect was more obvious as the R-distance increased. The spatial resolution of the advanced RR method was 20 % better than that of FBP and OSEM. The resolution recovery ratio was 80 %, and the count recovery was maintained only in objects with a diameter of >30 mm in the advanced RR method. The NMSE and %CV was 50 and 30 % improved over FBP and OSEM, respectively. The advanced RR method caused overestimation due to Gibbs's phenomenon in the marginal region when the diameter of the sphere was 16-28.8 mm.

  1. Project Performance Evaluation Using Deep Belief Networks

    NASA Astrophysics Data System (ADS)

    Nguvulu, Alick; Yamato, Shoso; Honma, Toshihisa

    A Project Assessment Indicator (PAI) Model has recently been applied to evaluate monthly project performance based on 15 project elements derived from the project management (PM) knowledge areas. While the PAI Model comprehensively evaluates project performance, it lacks objectivity and universality. It lacks objectivity because experts assign model weights intuitively based on their PM skills and experience. It lacks universality because the allocation of ceiling scores to project elements is done ad hoc based on the empirical rule without taking into account the interactions between the project elements. This study overcomes these limitations by applying a DBN approach where the model automatically assigns weights and allocates ceiling scores to the project elements based on the DBN weights which capture the interaction between the project elements. We train our DBN on 5 IT projects of 12 months duration and test it on 8 IT projects with less than 12 months duration. We completely eliminate the manual assigning of weights and compute ceiling scores of project elements based on DBN weights. Our trained DBN evaluates monthly project performance of the 8 test projects based on the 15 project elements to within a monthly relative error margin of between ±1.03 and ±3.30%.

  2. Two Decades of WRF/CMAQ simulations over the continental United States: New approaches for performing dynamic model evaluation and determining confidence limits for ozone exceedances

    EPA Science Inventory

    Confidence in the application of models for forecasting and regulatory assessments is furthered by conducting four types of model evaluation: operational, dynamic, diagnostic, and probabilistic. Operational model evaluation alone does not reveal the confidence limits that can be ...

  3. Two Decades of WRF/CMAQ simulations over the continental United States: New approaches for performing dynamic model evaluation and determining confidence limits for ozone exceedances

    EPA Science Inventory

    Confidence in the application of models for forecasting and regulatory assessments is furthered by conducting four types of model evaluation: operational, dynamic, diagnostic, and probabilistic. Operational model evaluation alone does not reveal the confidence limits that can be ...

  4. Evaluation of the clinical performance of ultrahigh molecular weight polyethylene fiber cable using a dog osteosynthesis model.

    PubMed

    Oe, Kenichi; Jingushi, Seiya; Iida, Hirokazu; Tomita, Naohide

    2013-01-01

    The purpose of this study was to assess the removability and biological reactivity of an ultrahigh molecular weight polyethylene (UHMWPE) fiber cable as a new biomaterial for osteosynthesis. We used a pull-out test and an implantation test to analyze the performance of the UHMWPE fiber cable using a dog model, and compared its characteristics with those of a wire cable and a soft wire. In the pull-out test, the UHMWPE fiber cable was as easy to remove as the soft wire, and both the UHMWPE fiber cable and the soft wire were significantly easier to remove than the wire cable. The fixation capability and the biological reactivity of the UHMWPE fiber cable were examined in an osteosynthesis model of the dog greater trochanter, and were compared with those of the soft wire. The bone union rate, assessed radiographically, was very similar when using the UHMWPE fiber cable and the soft wire. However, in the soft wire group, both the surface of the greater trochanter under the fixation material and the penetration area around the fixation material showed an increased tendency toward a biological reaction, including inflammation and granulation tissue formation, as compared to the UHMWPE fiber cable group. The UHMWPE fiber cable was as easily removed from the bone tissue as the soft wire, and was easier to remove than the wire cable. Additionally, the UHMWPE fiber cable caused reduced biological reactivity with the surrounding tissue, as compared with the soft wire. In conclusion, the UHMWPE fiber cable appeared to be a suitable fixation material for osteosynthesis.

  5. Evaluation of solar pond performance

    SciTech Connect

    Wittenberg, L.J.

    1980-01-01

    The City of Miamisburg, Ohio, constructed during 1978 a large, salt-gradient solar pond as part of its community park development project. The thermal energy stored in the pond is being used to heat an outdoor swimming pool in the summer and an adjacent recreational building during part of the winter. This solar pond, which occupies an area of 2020 m/sup 2/ (22,000 sq. ft.), was designed from experience obtained at smaller research ponds located at Ohio State University, the University of New Mexico and similar ponds operated in Israel. During the summer of 1979, the initial heat (40,000 kWh, 136 million Btu) was withdrawn from the solar pond to heat the outdoor swimming pool. All of the data collection systems were installed and functioned as designed so that operational data were obtained. The observed performance of the pond was compared with several of the predicted models for this type of pond. (MHR)

  6. Using a shared governance structure to evaluate the implementation of a new model of care: the shared experience of a performance improvement committee.

    PubMed

    Myers, Mary; Parchen, Debra; Geraci, Marilla; Brenholtz, Roger; Knisely-Carrigan, Denise; Hastings, Clare

    2013-10-01

    Sustaining change in the behaviors and habits of experienced practicing nurses can be frustrating and daunting, even when changes are based on evidence. Partnering with an active shared governance structure to communicate change and elicit feedback is an established method to foster partnership, equity, accountability, and ownership. Few recent exemplars in the literature link shared governance, change management, and evidence-based practice to transitions in care models. This article describes an innovative staff-driven approach used by nurses in a shared governance performance improvement committee to use evidence-based practice in determining the best methods to evaluate the implementation of a new model of care.

  7. Using a Shared Governance Structure to Evaluate the Implementation of a New Model of Care: The Shared Experience of a Performance Improvement Committee

    PubMed Central

    Myers, Mary; Parchen, Debra; Geraci, Marilla; Brenholtz, Roger; Knisely-Carrigan, Denise; Hastings, Clare

    2013-01-01

    Sustaining change in the behaviors and habits of experienced practicing nurses can be frustrating and daunting, even when changes are based on evidence. Partnering with an active shared governance structure to communicate change and elicit feedback is an established method to foster partnership, equity, accountability and ownership. Few recent exemplars in the literature link shared governance, change management and evidence-based practice to transitions in care models. This article describes an innovative staff-driven approach used by nurses in a shared governance performance improvement committee to use evidence based practice in determining the best methods to evaluate the implementation of a new model of care. PMID:24061583

  8. 48 CFR 2936.604 - Performance evaluation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 7 2011-10-01 2011-10-01 false Performance evaluation... Performance evaluation. (a) The HCA must establish procedures to evaluate architect-engineer contractor performance as required in FAR 36.604. Normally, the performance report must be prepared by the...

  9. A system-level mathematical model for evaluation of power train performance of load-leveled electric-vehicles

    NASA Technical Reports Server (NTRS)

    Purohit, G. P.; Leising, C. J.

    1984-01-01

    The power train performance of load leveled electric vehicles can be compared with that of nonload leveled systems by use of a simple mathematical model. This method of measurement involves a number of parameters including the degree of load leveling and regeneration, the flywheel mechanical to electrical energy fraction, and efficiencies of the motor, generator, flywheel, and transmission. Basic efficiency terms are defined and representative comparisons of a variety of systems are presented. Results of the study indicate that mechanical transfer of energy into and out of the flywheel is more advantageous than electrical transfer. An optimum degree of load leveling may be achieved in terms of the driving cycle, battery characteristics, mode of mechanization, and the efficiency of the components. For state of the art mechanically coupled flyheel systems, load leveling losses can be held to a reasonable 10%; electrically coupled systems can have losses that are up to six times larger. Propulsion system efficiencies for mechanically coupled flywheel systems are predicted to be approximately the 60% achieved on conventional nonload leveled systems.

  10. Preclinical Performance Evaluation of Percutaneous Glucose Biosensors

    PubMed Central

    Soto, Robert J.; Schoenfisch, Mark H.

    2015-01-01

    The utility of continuous glucose monitoring devices remains limited by an obstinate foreign body response (FBR) that degrades the analytical performance of the in vivo sensor. A number of novel materials that resist or delay the FBR have been proposed as outer, tissue-contacting glucose sensor membranes as a strategy to improve sensor accuracy. Traditionally, researchers have examined the ability of a material to minimize the host response by assessing adsorbed cell morphology and tissue histology. However, these techniques do not adequately predict in vivo glucose sensor function, necessitating sensor performance evaluation in a relevant animal model prior to human testing. Herein, the effects of critical experimental parameters, including the animal model and data processing methods, on the reliability and usefulness of preclinical sensor performance data are considered. PMID:26085566

  11. Performance evaluation of an automotive thermoelectric generator

    NASA Astrophysics Data System (ADS)

    Dubitsky, Andrei O.

    Around 40% of the total fuel energy in typical internal combustion engines (ICEs) is rejected to the environment in the form of exhaust gas waste heat. Efficient recovery of this waste heat in automobiles can promise a fuel economy improvement of 5%. The thermal energy can be harvested through thermoelectric generators (TEGs) utilizing the Seebeck effect. In the present work, a versatile test bench has been designed and built in order to simulate conditions found on test vehicles. This allows experimental performance evaluation and model validation of automotive thermoelectric generators. An electrically heated exhaust gas circuit and a circulator based coolant loop enable integrated system testing of hot and cold side heat exchangers, thermoelectric modules (TEMs), and thermal interface materials at various scales. A transient thermal model of the coolant loop was created in order to design a system which can maintain constant coolant temperature under variable heat input. Additionally, as electrical heaters cannot match the transient response of an ICE, modelling was completed in order to design a relaxed exhaust flow and temperature history utilizing the system thermal lag. This profile reduced required heating power and gas flow rates by over 50%. The test bench was used to evaluate a DOE/GM initial prototype automotive TEG and validate analytical performance models. The maximum electrical power generation was found to be 54 W with a thermal conversion efficiency of 1.8%. It has been found that thermal interface management is critical for achieving maximum system performance, with novel designs being considered for further improvement.

  12. Hydrological evaluation of landfill performance (HELP) model assessment of the geology at Los Alamos National Laboratory, Technical Area 54, Material Disposal Area J

    SciTech Connect

    Vigil-Holterman, L.

    2002-01-01

    The purpose of this paper is: (1) conduct HELP model variations in weather data, profile characteristics, and hydraulic conductivities for major rock units; (2) compare and contrast the results of simulations; (3) obtain an estimation of leakage through the landfill from the surface to the aquifer; and (4) evaluate contaminant transport to the aquifer utilizing leakage estimation. The conclusions of this paper are: (1) the HELP model is useful to assess landfill design alternatives or the performance of a pre-existing landfill; (2) model results using site-specific data incorporated into the Weather Generator (Trail 4), varied significantly from generalized runs (Trials 1-3), consequently, models that lack site-specific data should be used cautiously; and (3) data from this study suggest that there will not be significant downward percolation of leachate from the surface of the landfill cap to the aquifer-leachate transport rates have been calculated to be slow.

  13. Performance Evaluation of a Data Validation System

    NASA Technical Reports Server (NTRS)

    Wong, Edmond (Technical Monitor); Sowers, T. Shane; Santi, L. Michael; Bickford, Randall L.

    2005-01-01

    Online data validation is a performance-enhancing component of modern control and health management systems. It is essential that performance of the data validation system be verified prior to its use in a control and health management system. A new Data Qualification and Validation (DQV) Test-bed application was developed to provide a systematic test environment for this performance verification. The DQV Test-bed was used to evaluate a model-based data validation package known as the Data Quality Validation Studio (DQVS). DQVS was employed as the primary data validation component of a rocket engine health management (EHM) system developed under NASA's NGLT (Next Generation Launch Technology) program. In this paper, the DQVS and DQV Test-bed software applications are described, and the DQV Test-bed verification procedure for this EHM system application is presented. Test-bed results are summarized and implications for EHM system performance improvements are discussed.

  14. Cavitation performance evaluation for a condensate pump

    NASA Astrophysics Data System (ADS)

    Yu, A.; Yu, W. P.; Pan, Z. B.; Luo, X. W.; Ji, B.; Y Xu, H.

    2013-12-01

    Cavitation in a condensate pump with specific speed of 95 m·m3s-1·min-1 was treated in this study. Cavitation performance for the pump was tested experimentally, and the steady state cavitating flows in the pump impeller were simulated by RANS method as well as a homogeneous cavitation model. It is noted that cavitating flow simulation reasonably depicted cavitation development in the pump. Compared to the tested results, the numerical simulation basically predicted later performance drops due to cavitation. Unfortunately, the cavitation simulation at the operation condition of 50% best efficiency point could not predict the head drop up to 3%. By applying the concept of relative cavity length cavitation performance evaluation is achieved. For better application, future study is necessary to establish the relation between relative cavity length and performance drop.

  15. Evaluating GC/MS Performance

    SciTech Connect

    Alcaraz, A; Dougan, A

    2006-11-26

    and Water Check': By selecting View - Diagnostics/Vacuum Control - Vacuum - Air and Water Check. A Yes/No dialogue box will appear; select No (use current values). It is very important to select No! Otherwise the tune values are drastically altered. The software program will generate a water/air report similar to figure 3. Evaluating the GC/MS system with a performance standard: This procedure should allow the analyst to verify that the chromatographic column and associated components are working adequately to separate the various classes of chemical compounds (e.g., hydrocarbons, alcohols, fatty acids, aromatics, etc.). Use the same GC/MS conditions used to collect the system background and solvent check (part 1 of this document). Figure 5 is an example of a commercial GC/MS column test mixture used to evaluate GC/MS prior to analysis.

  16. Evaluating the Performance Improvement Preferences of Disability Service Managers: An Exploratory Study Using Gilbert's Behavior Engineering Model

    ERIC Educational Resources Information Center

    Wooderson, John R.; Cuskelly, Monica; Meyer, Kim A.

    2017-01-01

    Background: Front-line managers play an important role in managing the performance of staff working in services for people with intellectual disability, but little is known about the practices they prefer to use to improve staff performance and whether these align with what research has shown to be effective. Method: This study comprised two…

  17. 48 CFR 36.604 - Performance evaluation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Performance evaluation. 36.604 Section 36.604 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION SPECIAL... Performance evaluation. See 42.1502(f) for the requirements for preparing past performance evaluations for...

  18. 13 CFR 304.4 - Performance evaluations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Performance evaluations. 304.4... ECONOMIC DEVELOPMENT DISTRICTS § 304.4 Performance evaluations. (a) EDA shall evaluate the management standards, financial accountability and program performance of each District Organization within three...

  19. A Model Performance

    ERIC Educational Resources Information Center

    Thornton, Bradley D.; Smalley, Robert A.

    2008-01-01

    Building information modeling (BIM) uses three-dimensional modeling concepts, information technology and interoperable software to design, construct and operate a facility. However, BIM can be more than a tool for virtual modeling--it can provide schools with a 3-D walkthrough of a project while it still is on the electronic drawing board. BIM can…

  20. A Model Performance

    ERIC Educational Resources Information Center

    Thornton, Bradley D.; Smalley, Robert A.

    2008-01-01

    Building information modeling (BIM) uses three-dimensional modeling concepts, information technology and interoperable software to design, construct and operate a facility. However, BIM can be more than a tool for virtual modeling--it can provide schools with a 3-D walkthrough of a project while it still is on the electronic drawing board. BIM can…

  1. 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.

  2. 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.

  3. Behavioral patterns of environmental performance evaluation programs.

    PubMed

    Li, Wanxin; Mauerhofer, Volker

    2016-11-01

    During the past decades numerous environmental performance evaluation programs have been developed and implemented on different geographic scales. This paper develops a taxonomy of environmental management behavioral patterns in order to provide a practical comparison tool for environmental performance evaluation programs. Ten such programs purposively selected are mapped against the identified four behavioral patterns in the form of diagnosis, negotiation, learning, and socialization and learning. Overall, we found that schemes which serve to diagnose environmental abnormalities are mainly externally imposed and have been developed as a result of technical debates concerning data sources, methodology and ranking criteria. Learning oriented scheme is featured by processes through which free exchange of ideas, mutual and adaptive learning can occur. Scheme developed by higher authority for influencing behaviors of lower levels of government has been adopted by the evaluated to signal their excellent environmental performance. The socializing and learning classified evaluation schemes have incorporated dialogue, participation, and capacity building in program design. In conclusion we consider the 'fitness for purpose' of the various schemes, the merits of our analytical model and the future possibilities of fostering capacity building in the realm of wicked environmental challenges. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Error Reduction Program. [combustor performance evaluation codes

    NASA Technical Reports Server (NTRS)

    Syed, S. A.; Chiappetta, L. M.; Gosman, A. D.

    1985-01-01

    The details of a study to select, incorporate and evaluate the best available finite difference scheme to reduce numerical error in combustor performance evaluation codes are described. The combustor performance computer programs chosen were the two dimensional and three dimensional versions of Pratt & Whitney's TEACH code. The criteria used to select schemes required that the difference equations mirror the properties of the governing differential equation, be more accurate than the current hybrid difference scheme, be stable and economical, be compatible with TEACH codes, use only modest amounts of additional storage, and be relatively simple. The methods of assessment used in the selection process consisted of examination of the difference equation, evaluation of the properties of the coefficient matrix, Taylor series analysis, and performance on model problems. Five schemes from the literature and three schemes developed during the course of the study were evaluated. This effort resulted in the incorporation of a scheme in 3D-TEACH which is usuallly more accurate than the hybrid differencing method and never less accurate.

  5. Performance Evaluation of Various Parameterization Schemes in Weather Research and Forecasting (WRF) Model : A Case Study Subtropical Urban Agglomeration National Capital Region (NCR), India

    NASA Astrophysics Data System (ADS)

    Sindhwani, R.; Kumar, S.; Goyal, P.

    2015-12-01

    Meteorological parameters play a very significant and crucial role in simulating regional air quality. This study has been carried to evaluate the performance of WRF model to various combinations of physical parameterization schemes for predicting surface and upper air meteorology around the capital city of India, Delhi popularly known as National Capital Region (NCR). Eight sensitivity experiments has been conducted to find the best combination of the parameterization schemes for the study area during summer (4th - 18th April, 2010 ) season. The model predicted surface temperatures at 2m, relative humidity at 2m and wind speeds at 10m are compared with the observations from Central Pollution Control Board (at Dwarka and Shadipur monitoring stations) and Indian Meteorological Department (VIDP and VIDD stations) whereas the upper-air potential temperature profile and wind speed profile are validated using Wyoming Weather Web data archive at VIDD station. The qualitative and quantitative analysis of simulations indicate that for temperature and relative humidity, the combination consisting of Yonsei Unversity (YSU) as the Planetary Boundary Layer (PBL) scheme, the Monin Obhukhov as the surface layer (SL) scheme along with NOAH land surface model (LSM) has been found to be performing better than other combinations. The combination consisting of Mellor Yamada Janjic (Eta) as the PBL scheme, Monin Obhukhov Janjic (Eta) as the SL scheme and Noah LSM performs reasonably well in reproducing the observed wind conditions. This indicates that the selection of parameterization schemes may depend on the intended application of the model for a given region.

  6. On Models and Methods for Performance Measurement.

    DTIC Science & Technology

    1982-03-01

    Method I This form was originally defined and used by Rasch (1960) to develop a measurement model for measuring capability by observing dichotomous ...A performance quality model was defined. Illustrations of two performance models were provided through examples . DO I, OR 1473 CITION OF I NOV SS IS...persons who are to be evaluated by tests in which items are scored with dichotomous responses. 2. Model 11 should be used to assess capabilities of persons

  7. PERFORMANCE EVALUATION OF TYPE I MARINE SANITATION DEVICES

    EPA Science Inventory

    This performance test was designed to evaluate the effectiveness of two Type I Marine Sanitation Devices (MSDs): the Electro Scan Model EST 12, manufactured by Raritan Engineering Company, Inc., and the Thermopure-2, manufactured by Gross Mechanical Laboratories, Inc. Performance...

  8. PERFORMANCE EVALUATION OF TYPE I MARINE SANITATION DEVICES

    EPA Science Inventory

    This performance test was designed to evaluate the effectiveness of two Type I Marine Sanitation Devices (MSDs): the Electro Scan Model EST 12, manufactured by Raritan Engineering Company, Inc., and the Thermopure-2, manufactured by Gross Mechanical Laboratories, Inc. Performance...

  9. Performance evaluation of carbon dioxide-alkanolamine- water system by equation of state/excess Gibbs energy models

    NASA Astrophysics Data System (ADS)

    Suleman, H.; Maulud, A. S.; Man, Z.

    2016-06-01

    Numerous thermodynamic techniques have been applied to correlate carbon dioxide- alkanolamine-water systems, with varying accuracy and complexity. With advent of high pressure carbon dioxide absorption in industry, the development of high pressure thermodynamic models have became an exigency. Equation of state/excess Gibbs energy models promises a substantial improvement in this field. Many researchers have shown application of these models to high pressure vapour liquid equilibria of said system with good correlation. However, no study shows the range of application of these models in presence of other competitive techniques. Therefore, this study quantitatively describes the range of application of equation of state/excess Gibbs energy models to carbon dioxide-alkanolamine systems. The model uses Linear Combination of Vidal and Michelsen mixing rule for correlation of carbon dioxide absorption in single aqueous monoethanolamine, diethanolamine and methyldiethanolamine mixtures. The results show that correlation of equation of state/excess Gibbs energy models show a transient change at carbon dioxide loadings of 0.8. Therefore, these models are applicable to the above mentioned system for carbon dioxide loadings beyond 0.8 mol/mol and higher. The observations are similar in behaviour for all tested alkanolamines and are therefore generalized for the system.

  10. Performance evaluation of traveling wave ultrasonic motor based on a model with visco-elastic friction layer on stator.

    PubMed

    Qu, Jianjun; Sun, Fengyan; Zhao, Chunsheng

    2006-12-01

    A new visco-elastic contact model of traveling wave ultrasonic motor (TWUSM) is proposed. In this model, the rotor is assumed to be rigid body and the friction material on stator teeth surface to be visco-elastic body. Both load characteristics of TWUSM, such as rotation speed, torque and efficiency, and effects of interface parameters between stator and rotor on output characteristic of TWUSM can be calculated and simulated numerically by using MATLAB method based on this model. This model is compared with that one of compliant slider and rigid stator. The results show that this model can obtain bigger stall torque. The simulated results are compared with test results, and found that their load characteristics have good agreement.

  11. Integrated Assessment Model Evaluation

    NASA Astrophysics Data System (ADS)

    Smith, S. J.; Clarke, L.; Edmonds, J. A.; Weyant, J. P.

    2012-12-01

    Integrated assessment models of climate change (IAMs) are widely used to provide insights into the dynamics of the coupled human and socio-economic system, including emission mitigation analysis and the generation of future emission scenarios. Similar to the climate modeling community, the integrated assessment community has a two decade history of model inter-comparison, which has served as one of the primary venues for model evaluation and confirmation. While analysis of historical trends in the socio-economic system has long played a key role in diagnostics of future scenarios from IAMs, formal hindcast experiments are just now being contemplated as evaluation exercises. Some initial thoughts on setting up such IAM evaluation experiments are discussed. Socio-economic systems do not follow strict physical laws, which means that evaluation needs to take place in a context, unlike that of physical system models, in which there are few fixed, unchanging relationships. Of course strict validation of even earth system models is not possible (Oreskes etal 2004), a fact borne out by the inability of models to constrain the climate sensitivity. Energy-system models have also been grappling with some of the same questions over the last quarter century. For example, one of "the many questions in the energy field that are waiting for answers in the next 20 years" identified by Hans Landsberg in 1985 was "Will the price of oil resume its upward movement?" Of course we are still asking this question today. While, arguably, even fewer constraints apply to socio-economic systems, numerous historical trends and patterns have been identified, although often only in broad terms, that are used to guide the development of model components, parameter ranges, and scenario assumptions. IAM evaluation exercises are expected to provide useful information for interpreting model results and improving model behavior. A key step is the recognition of model boundaries, that is, what is inside

  12. Performance evaluation of linear time-series ionospheric Total Electron Content model over low latitude Indian GPS stations

    NASA Astrophysics Data System (ADS)

    Dabbakuti, J. R. K. Kumar; Venkata Ratnam, D.

    2017-10-01

    Precise modeling of the ionospheric Total Electron Content (TEC) is a critical aspect of Positioning, Navigation, and Timing (PNT) services intended for the Global Navigation Satellite Systems (GNSS) applications as well as Earth Observation System (EOS), satellite communication, and space weather forecasting applications. In this paper, linear time series modeling has been carried out on ionospheric TEC at two different locations at Koneru Lakshmaiah University (KLU), Guntur (geographic 16.44° N, 80.62° E; geomagnetic 7.55° N) and Bangalore (geographic 12.97° N, 77.59° E; geomagnetic 4.53° N) at the northern low-latitude region, for the year 2013 in the 24th solar cycle. The impact of the solar and geomagnetic activity on periodic oscillations of TEC has been investigated. Results confirm that the correlation coefficient of the estimated TEC from the linear model TEC and the observed GPS-TEC is around 93%. Solar activity is the key component that influences ionospheric daily averaged TEC while periodic component reveals the seasonal dependency of TEC. Furthermore, it is observed that the influence of geomagnetic activity component on TEC is different at both the latitudes. The accuracy of the model has been assessed by comparing the International Reference Ionosphere (IRI) 2012 model TEC and TEC measurements. Moreover, the absence of winter anomaly is remarkable, as determined by the Root Mean Square Error (RMSE) between the linear model TEC and GPS-TEC. On the contrary, the IRI2012 model TEC evidently failed to predict the absence of winter anomaly in the Equatorial Ionization Anomaly (EIA) crest region. The outcome of this work will be useful for improving the ionospheric now-casting models under various geophysical conditions.

  13. How Successful Is Performance Evaluation?

    ERIC Educational Resources Information Center

    Gray, Frank

    We should no longer be wondering if we should have performance appraisal, rather we should be researching the elements necessary for it to be successfully implemented and to ensure that we receive maximum benefits for improved learning for our students. Performance appraisal can be defined as "a positive, systematic, individualized due…

  14. A Proposed RTN Officer Performance Evaluation System

    DTIC Science & Technology

    1989-12-01

    studiod at the Naval Postpraduate School and practical theories relating to personnel management and performance evaluation. 4 The research method includes...various systems are discussed as the researcher perceives them. The fact that there is probably no agreed upon, fool-proof method of evaluating an...Performance Evaluation System. The research methodology Includes the following three componen: (1) a study of pertinent performance evaluation

  15. Model based evaluation of the effect of pH and electrode geometry on microbial fuel cell performance.

    PubMed

    Picioreanu, Cristian; van Loosdrecht, Mark C M; Curtis, Thomas P; Scott, Keith

    2010-04-01

    A mathematical model for microbial fuel cells (MFC) which integrates macro-scale time-dependent mass balances for solutes and biomass in the anodic liquid with a micro-scale individual-based two-dimensional biofilm model is developed. Computational fluid dynamics and Nernst-Plank mass and charge balances with diffusion, electromigration, convection and electroneutrality in the biofilm are combined to calculate spatial pH distribution and solutes speciation. Soluble redox mediators are the electron shuttle between microbial cells and the electrode. The model describes the generally observed variations of pH, solute concentrations and electrical current produced over time from electroactive biofilms. Numerical simulations also show the effect of bicarbonate buffer and mass transfer through the proton exchange membrane on the microbial population within a mixed anaerobic digestion sludge consortium of methanogenic and electrogenic microorganisms. In addition, the new modeling approach opens the way to study the influence of fluid flow and any two- or three-dimensional biofilm and electrode geometry on the MFC output parameters. Hydrodynamic calculations show that porous bio-electrodes with greater specific surface area do not necessarily produce more current, as long as convection through the pores is absent. An innovative model solution strategy combines in a very efficient and flexible way MATLAB, COMSOL finite element and Java codes.

  16. EVALUATING THE PERFORMANCE OF REGIONAL-SCALE PHOTOCHEMICAL MODELING SYSTEMS. PART III-PRECURSOR PREDICTIONS. (R825260)

    EPA Science Inventory

    Abstract

    Two regional-scale photochemical modeling systems, RAMS/UAM-V and MM5/MAQSIP, are used to simulate precursor concentrations for 4 June¯31 August 1995 period. The time series of simulated and observed precursor concentrations are spectrally deco...

  17. EVALUATING THE PERFORMANCE OF REGIONAL-SCALE PHOTOCHEMICAL MODELING SYSTEMS. PART III-PRECURSOR PREDICTIONS. (R825260)

    EPA Science Inventory

    Abstract

    Two regional-scale photochemical modeling systems, RAMS/UAM-V and MM5/MAQSIP, are used to simulate precursor concentrations for 4 June¯31 August 1995 period. The time series of simulated and observed precursor concentrations are spectrally deco...

  18. On the use of the post-closure method uncertainty band to evaluate the performance of land surface models against eddy covariance flux data

    NASA Astrophysics Data System (ADS)

    Ingwersen, J.; Imukova, K.; Högy, P.; Streck, T.

    2014-12-01

    The energy balance of eddy covariance (EC) flux data is normally not closed. Therefore, at least if used for modeling, EC flux data are usually post-closed, i.e. the measured turbulent fluxes are adjusted so as to close the energy balance. At the current state of knowledge, however, it is not clear how to partition the missing energy in the right way. Eddy flux data therefore contain some uncertainty due to the unknown nature of the energy balance gap, which should be considered in model evaluation and the interpretation of simulation results. We propose to construct the post-closure method uncertainty band (PUB), which essentially designates the differences between non-adjusted flux data and flux data adjusted with the three post-closure methods (Bowen ratio, latent heat flux (LE) and sensible heat flux (H) method). To demonstrate this approach, simulations with the NOAH-MP land surface model were evaluated based on EC measurements conducted at a winter wheat stand in Southwest Germany in 2011, and the performance of the Jarvis and Ball-Berry stomatal resistance scheme was compared. The width of the PUB of the LE was up to 110 W m-2 (21% of net radiation). Our study shows that it is crucial to account for the uncertainty of EC flux data originating from lacking energy balance closure. Working with only a single post-closing method might result in severe misinterpretations in model-data comparisons.

  19. On the use of the post-closure methods uncertainty band to evaluate the performance of land surface models against eddy covariance flux data

    NASA Astrophysics Data System (ADS)

    Ingwersen, J.; Imukova, K.; Högy, P.; Streck, T.

    2015-04-01

    The energy balance of eddy covariance (EC) flux data is normally not closed. Therefore, at least if used for modelling, EC flux data are usually post-closed, i.e. the measured turbulent fluxes are adjusted so as to close the energy balance. At the current state of knowledge, however, it is not clear how to partition the missing energy in the right way. Eddy flux data therefore contain some uncertainty due to the unknown nature of the energy balance gap, which should be considered in model evaluation and the interpretation of simulation results. We propose to construct the post-closure methods uncertainty band (PUB), which essentially designates the differences between non-adjusted flux data and flux data adjusted with the three post-closure methods (Bowen ratio, latent heat flux (LE) and sensible heat flux (H) method). To demonstrate this approach, simulations with the NOAH-MP land surface model were evaluated based on EC measurements conducted at a winter wheat stand in southwest Germany in 2011, and the performance of the Jarvis and Ball-Berry stomatal resistance scheme was compared. The width of the PUB of the LE was up to 110 W m-2 (21% of net radiation). Our study shows that it is crucial to account for the uncertainty in EC flux data originating from lacking energy balance closure. Working with only a single post-closing method might result in severe misinterpretations in model-data comparisons.

  20. On the use of the post-closure methods uncertainty band to evaluate the performance of land surface models against eddy covariance flux data

    NASA Astrophysics Data System (ADS)

    Ingwersen, Joachim; Imukova, Kristina; Högy, Petra; Streck, Thilo

    2017-04-01

    The energy balance of eddy covariance (EC) flux data is normally not closed. Therefore, at least if used for modeling, EC flux data are usually post-closed, i.e. the measured turbulent fluxes are adjusted so as to close the energy balance. At the current state of knowledge, however, it is not clear how to partition the missing energy in the right way. Eddy flux data therefore contain some uncertainty due to the unknown nature of the energy balance gap, which should be considered in model evaluation and the interpretation of simulation results. We propose to construct the post-closure method uncertainty band (PUB), which essentially designates the differences between non-adjusted flux data and flux data adjusted with the three post-closure methods (Bowen ratio, latent heat flux (LE) and sensible heat flux (H) method). To demonstrate this approach, simulations with the NOAH-MP land surface model were evaluated based on EC measurements conducted at a winter wheat stand in Southwest Germany in 2011, and the performance of the Jarvis and Ball-Berry stomatal resistance scheme was compared. The width of the PUB of the LE was up to 110 W/m2 (21% of net radiation). Our study shows that it is crucial to account for the uncertainty of EC flux data originating from lacking energy balance closure. Working with only a single post-closing method might result in severe misinterpretations in model-data comparisons.

  1. Seismic Performance Evaluation of Concentrically Braced Frames

    NASA Astrophysics Data System (ADS)

    Hsiao, Po-Chien

    Concentrically braced frames (CBFs) are broadly used as lateral-load resisting systems in buildings throughout the US. In high seismic regions, special concentrically braced frames (SCBFs) where ductility under seismic loading is necessary. Their large elastic stiffness and strength efficiently sustains the seismic demands during smaller, more frequent earthquakes. During large, infrequent earthquakes, SCBFs exhibit highly nonlinear behavior due to brace buckling and yielding and the inelastic behavior induced by secondary deformation of the framing system. These response modes reduce the system demands relative to an elastic system without supplemental damping. In design the re reduced demands are estimated using a response modification coefficient, commonly termed the R factor. The R factor values are important to the seismic performance of a building. Procedures put forth in FEMAP695 developed to R factors through a formalized procedure with the objective of consistent level of collapse potential for all building types. The primary objective of the research was to evaluate the seismic performance of SCBFs. To achieve this goal, an improved model including a proposed gusset plate connection model for SCBFs that permits accurate simulation of inelastic deformations of the brace, gusset plate connections, beams and columns and brace fracture was developed and validated using a large number of experiments. Response history analyses were conducted using the validated model. A series of different story-height SCBF buildings were designed and evaluated. The FEMAP695 method and an alternate procedure were applied to SCBFs and NCBFs. NCBFs are designed without ductile detailing. The evaluation using P695 method shows contrary results to the alternate evaluation procedure and the current knowledge in which short-story SCBF structures are more venerable than taller counterparts and NCBFs are more vulnerable than SCBFs.

  2. Performance evaluation of IVC systems.

    PubMed

    Brandstetter, H; Scheer, M; Heinekamp, C; Gippner-Steppert, C; Loge, O; Ruprecht, L; Thull, B; Wagner, R; Wilhelm, P; Scheuber, H-P

    2005-01-01

    An expert Working Group was set up in December 2000 to develop recommendations for users and industry on the evaluation of proper function and operation of individually ventilated cage (IVC) systems. The full report of their recommendations is in two parts--'Part 1: Test Instructions' and 'Part 2: Evaluation Criteria'--both of which have been published in full on the Laboratory Animals Ltd website. They can be found at http://www.lal.org.uk/IVC/index.html. Evaluation of and feedback on the recommendations to further refine their use and scientific basis is encouraged. This Summary Report provides a brief overview of the background to the development of the full report and the issues it addresses.

  3. VPPA weld model evaluation

    NASA Technical Reports Server (NTRS)

    Mccutcheon, Kimble D.; Gordon, Stephen S.; Thompson, Paul A.

    1992-01-01

    NASA uses the Variable Polarity Plasma Arc Welding (VPPAW) process extensively for fabrication of Space Shuttle External Tanks. This welding process has been in use at NASA since the late 1970's but the physics of the process have never been satisfactorily modeled and understood. In an attempt to advance the level of understanding of VPPAW, Dr. Arthur C. Nunes, Jr., (NASA) has developed a mathematical model of the process. The work described in this report evaluated and used two versions (level-0 and level-1) of Dr. Nunes' model, and a model derived by the University of Alabama at Huntsville (UAH) from Dr. Nunes' level-1 model. Two series of VPPAW experiments were done, using over 400 different combinations of welding parameters. Observations were made of VPPAW process behavior as a function of specific welding parameter changes. Data from these weld experiments was used to evaluate and suggest improvements to Dr. Nunes' model. Experimental data and correlations with the model were used to develop a multi-variable control algorithm for use with a future VPPAW controller. This algorithm is designed to control weld widths (both on the crown and root of the weld) based upon the weld parameters, base metal properties, and real-time observation of the crown width. The algorithm exhibited accuracy comparable to that of the weld width measurements for both aluminum and mild steel welds.

  4. Performance Evaluation of Alcohol-Gasoline Blends in 1980 Model Automobiles. Phase II. Methanol-Gasoline Blends.

    DTIC Science & Technology

    1984-01-01

    weight percent, and included fuels with and without isobutanol co-solvent. Ten of the fourteen 1980 model cars from the Phase I portion of the... products , or organizations constitute endorsement or recommendation for use or non-use. I.4. -p ’.1, vt. .4 2 -p. ’V 4. 4. .1 *~1.~ ’S V. -V a..). S...Trial Blends ................................... 22 3-4 - Changes in Vapor/Liquid Ratios Between Methanol and Methanol/ Isobutanol Blends

  5. 48 CFR 2936.604 - Performance evaluation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CONTRACTING REQUIREMENTS CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Architect-Engineer Services 2936.604 Performance evaluation. (a) The HCA must establish procedures to evaluate architect-engineer contractor... reports must be made using Standard Form 1421, Performance Evaluation (Architect-Engineer) as...

  6. 13 CFR 304.4 - Performance evaluations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Performance evaluations. 304.4 Section 304.4 Business Credit and Assistance ECONOMIC DEVELOPMENT ADMINISTRATION, DEPARTMENT OF COMMERCE ECONOMIC DEVELOPMENT DISTRICTS § 304.4 Performance evaluations. (a) EDA shall evaluate the...

  7. Improving Teacher Performance through Evaluation and Supervision.

    ERIC Educational Resources Information Center

    Drake, Jackson M.

    To guarantee an efficient educational system, effective evaluation and supervision of teacher performance are necessary. However, the evaluation of teacher performance presents two major problems: first, no clear definition or measure of effective teaching exists, and second, evaluation is perceived to have conflicting purposes, either as a…

  8. What makes a top research medical school? A call for a new model to evaluate academic physicians and medical school performance.

    PubMed

    Goldstein, Matthew J; Lunn, Mitchell R; Peng, Lily

    2015-05-01

    Since the publication of the Flexner Report in 1910, the medical education enterprise has undergone many changes to ensure that medical schools meet a minimum standard for the curricula and clinical training they offer students. Although the efforts of the licensing and accrediting bodies have raised the quality of medical education, the educational processes that produce the physicians who provide the best patient care and conduct the best biomedical research have not been identified. Comparative analyses are powerful tools to understand the differences between institutions, but they are challenging to carry out. As a result, the analysis performed by U.S. News & World Report (USN&WR) has become the default tool to compare U.S. medical schools. Medical educators must explore more rigorous and equitable approaches to analyze and understand the performance of medical schools. In particular, a better understanding and more thorough evaluation of the most successful institutions in producing academic physicians with biomedical research careers are needed. In this Perspective, the authors present a new model to evaluate medical schools' production of academic physicians who advance medicine through basic, clinical, translational, and implementation science research. This model is based on relevant and accessible objective criteria that should replace the subjective criteria used in the current USN&WR rankings system. By fostering a national discussion about the most meaningful criteria that should be measured and reported, the authors hope to increase transparency of assessment standards and ultimately improve educational quality.

  9. Consistency in Piano Performance Evaluation.

    ERIC Educational Resources Information Center

    Wapnick, Joel; And Others

    1993-01-01

    Reports on a study of the use of musical scores and rating scales by 80 pianists who listened to 21 trials of solo piano music. Found that the use of musical scores and rating scales did not improve interrater reliability. Discovered that the subjects were less consistent when evaluating slow musical pieces than faster pieces. (CFR)

  10. Distributed Explosive Performance Model

    DTIC Science & Technology

    1998-01-01

    18 Analytic Code ( DEPAC ). DEPAC is a restructured and an upgraded one-stop code of the previous version of the Linear Explosive Array Performance...findings1. 3. Developed the initial version of DEPAC (LEAP and LAM) 3. 4. Released three Technical Results (TRs). 5. Established the methodology for quick...the input files for each run for CTH, process the data generated by CTH, and create the input database files for DEPAC . The line charge is composed of

  11. Performance evaluation of generalized MSK

    NASA Astrophysics Data System (ADS)

    Galko, P.; Pasupathy, S.

    The computation of the performance of several optimal and suboptimal receivers for generalized MSK is discussed. The optimal receivers considered are Viterbi receivers and the optimal receivers based on a finite observation interval. Two suboptimal receivers, (1) optimized linear receivers based on finite observation intervals and (2) linear receivers based on approximating generalized MSK as an OQPSK signal, are considered as well. It is shown that the former receiver's performance may be computed exactly, while for the latter receiver it is possible to provide arbitrarily tight bounds on the performance. These analyses are illustrated by application to the two popular generalized MSK schemes of duobinary MSK (or FSOQ) and (1 + D)squared/4 MSK.

  12. 48 CFR 236.604 - Performance evaluation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Architect-Engineer Services 236.604 Performance evaluation. (a) Preparation of performance reports. Use DD Form 2631, Performance Evaluation (Architect-Engineer), instead of SF 1421. (2) Prepare a...

  13. Performance evaluation of ocean color satellite models for deriving accurate chlorophyll estimates in the Gulf of Saint Lawrence

    NASA Astrophysics Data System (ADS)

    Montes-Hugo, M.; Bouakba, H.; Arnone, R.

    2014-06-01

    The understanding of phytoplankton dynamics in the Gulf of the Saint Lawrence (GSL) is critical for managing major fisheries off the Canadian East coast. In this study, the accuracy of two atmospheric correction techniques (NASA standard algorithm, SA, and Kuchinke's spectral optimization, KU) and three ocean color inversion models (Carder's empirical for SeaWiFS (Sea-viewing Wide Field-of-View Sensor), EC, Lee's quasi-analytical, QAA, and Garver- Siegel-Maritorena semi-empirical, GSM) for estimating the phytoplankton absorption coefficient at 443 nm (aph(443)) and the chlorophyll concentration (chl) in the GSL is examined. Each model was validated based on SeaWiFS images and shipboard measurements obtained during May of 2000 and April 2001. In general, aph(443) estimates derived from coupling KU and QAA models presented the smallest differences with respect to in situ determinations as measured by High Pressure liquid Chromatography measurements (median absolute bias per cruise up to 0.005, RMSE up to 0.013). A change on the inversion approach used for estimating aph(443) values produced up to 43.4% increase on prediction error as inferred from the median relative bias per cruise. Likewise, the impact of applying different atmospheric correction schemes was secondary and represented an additive error of up to 24.3%. By using SeaDAS (SeaWiFS Data Analysis System) default values for the optical cross section of phytoplankton (i.e., aph(443) = aph(443)/chl = 0.056 m2mg-1), the median relative bias of our chl estimates as derived from the most accurate spaceborne aph(443) retrievals and with respect to in situ determinations increased up to 29%.

  14. Predicting Radiation Induced Performance Decrements of AH-1 Helicopter Crews. Volume 2. Evaluation of Modeling and Simulation Techniques for Predicting Radiation Induced Performance Decrements

    DTIC Science & Technology

    1993-03-01

    X E-2 jerk joule 1J) 1.000 0 XOOX E#9 jouleikilogram IJ/Kgl (radiation dose absorbed) Gray IGyv 1.000000 kilotons teraJoules 4.183 kip 11000 Ibfl...newton (N) 4.448 222 X E*3 kip /tnch 2 (ksti kilo pascal tkPa) 6.894 757 X E+3 ktap newton-secondim 2 IN-s/M 2) 1.000 000 X E-2 micron meter (mI 1.000 000...designed as a research tool for following performance changes over time, treatments, dosages or levels ( Thorne , Genser, Sing & Hegge, 1985). The WRPAB

  15. Particle Concentrations Inside a Tavern Before and After Prohibition of Smoking: Evaluating the Performance of an Indoor Air Quality Model.

    PubMed

    Ott, Wayne; Switzer, Paul; Robinson, John

    1996-12-01

    Measurements were made of respirable suspended particles (RSP) in a large sports tavern on 26 dates over approximately two years in which smoking was allowed, followed by measurements on 50 dates during the year after smoking was prohibited. The smoking prohibition occurred without warning when the city government passed a regulation restricting smoking in local restaurants and taverns. Two follow-up field surveys, consisting of 24 and 26 visits, respectively, were conducted to measure changes in RSP levels after smoking was prohibited. No decrease in tavern attendance was evident after smoking was prohibited. During the smoking period, the average RSP concentration was 56.8 |ig/m3 above the outdoor concentrations, but the average abruptly dropped to 5.9 ug/m3 above outdoor levels-a 90% decrease- on 24 visits in the first two months immediately after smoking was prohibited (first follow-up study). A second set of 26 follow-up visits (matched by time of day, day of the week, and season to the earlier smoking visits) yielded an average concentration of 12.9 jig/m3 above the outdoor levels, or an overall decrease in the average RSP concentration of 77% compared with the smoking period. During the smoking period, RSP concentrations more than 100 ug/m3 above outdoor levels occurred on 30.7% of the visits. During the 50 nonsmoking visits, 92% of the RSP concentrations were less than 20 u,g/m3 above outdoor levels, and no concentration exceeded 100 ug/m3 on any nonsmoking visit. The data show there was a striking decline in indoor RSP concentrations in the tavern after smoking was prohibited. The indoor concentration observed in the nonsmoking periods (9.1 u.g/m3 average for all nonsmoking visits) was attributed to cooking and resuspended dust. A mathematical model based on the mass balance equation was developed that included smoking, cooking, and resuspended dust. Using cigarette emission rates from the literature, the tavern volume of 521 m3, and the air exchange rate

  16. Model Validation and Performance Evaluation for The Multi-Tethered Aerostat Subsystem of the Large Adaptive Reflector

    NASA Astrophysics Data System (ADS)

    Nahon, Meyer; Lambert, Casey; Chalmers, Dean; Bo, Wen

    2004-06-01

    The Canadian design for the Square Kilometre Array radio telescope includes a large multi-tethered aerostat to support the telescope’s receiver. To validate this design concept, two parallel tracks have been undertaken: a numerical simulation of the multi-tethered aerostat system has been assembled, and a one-third scale prototype of the system has been constructed. This paper describes the experimental facility, presents results from initial tests of the uncontrolled system and compares these results to the predictions of the computer model of the system. Generally, the results compare very favourably. Using the simulation, we arrive at two important design philosophies to be used in the design of the full-scale system: (a) perturbations on the confluence point should be minimized, and (b) the system stiffness should be maximized to ensure minimum response to disturbances.

  17. Infrasound Sensor Models and Evaluations

    SciTech Connect

    KROMER,RICHARD P.; MCDONALD,TIMOTHY S.

    2000-07-31

    Sandia National Laboratories has continued to evaluate the performance of infrasound sensors that are candidates for use by the International Monitoring System (IMS) for the Comprehensive Nuclear-Test-Ban Treaty Organization. The performance criteria against which these sensors are assessed are specified in ``Operational Manual for Infra-sound Monitoring and the International Exchange of Infrasound Data''. This presentation includes the results of efforts concerning two of these sensors: (1) Chaparral Physics Model 5; and (2) CEA MB2000. Sandia is working with Chaparral Physics in order to improve the capability of the Model 5 (a prototype sensor) to be calibrated and evaluated. With the assistance of the Scripps Institution of Oceanography, Sandia is also conducting tests to evaluate the performance of the CEA MB2000. Sensor models based on theoretical transfer functions and manufacturer specifications for these two devices have been developed. This presentation will feature the results of coherence-based data analysis of signals from a huddle test, utilizing several sensors of both types, in order to verify the sensor performance.

  18. Perspectives on human performance modelling

    SciTech Connect

    Pew, R.W.; Baron, S.

    1983-11-01

    A combination of psychologically-based and control-theoretic approaches to human performance modelling results in other models which have the potential for unifying related works in psychology, artificial intelligence, and system-oriented supervisory control. 33 references.

  19. GPS User Equipment Performance Evaluation.

    DTIC Science & Technology

    1979-11-01

    Unit Device Controller Assembly ( UDCA ) * Satellite Signal Generator Assembly (SSGA) • Dynanic Frequency Synthesizer Assembly (DFSA) * Jamming...Post Run Data (PR)) under operator control. The UDCA performs the following primary functions: * Receive digital data from I)I’A, buffer and transfer to...collected by the 1IJKA, reformatted, and sent to the I)IA, and vice versa, via a data bus interface. The UDCA consists of the following elcliiti S

  20. Lubricant Evaluation and Performance 2

    DTIC Science & Technology

    1994-02-01

    POWER DIRECTORATE WRIGHT LABORATORY AIR FORCE MATERIEL COMMAND WRIGHT-PATrERSON AIR FORCE BASE , OHIO 45433-7103 94 5 10 011 NOTICE When government...INTRODUCTION I R DEVELOPMENT OF IMPROVED METHODS FOR MEASURING LUBRICANT PERFORMANCE 3 1 OXIDATIVE STABILITY OF ESTER BASE LUBRICANTS 3 a. Introduction 3 b...7) Conclusions 134 i. Stability Testing of Cyclophosphazene Based Fluids 134 (1) Introduction 134 (2) Effect of Metal Specimens 134 (3) Effect of a

  1. Performance Evaluation of PBL Schemes of ARW Model in Simulating Thermo-Dynamical Structure of Pre-Monsoon Convective Episodes over Kharagpur Using STORM Data Sets

    NASA Astrophysics Data System (ADS)

    Madala, Srikanth; Satyanarayana, A. N. V.; Srinivas, C. V.; Tyagi, Bhishma

    2016-05-01

    In the present study, advanced research WRF (ARW) model is employed to simulate convective thunderstorm episodes over Kharagpur (22°30'N, 87°20'E) region of Gangetic West Bengal, India. High-resolution simulations are conducted using 1 × 1 degree NCEP final analysis meteorological fields for initial and boundary conditions for events. The performance of two non-local [Yonsei University (YSU), Asymmetric Convective Model version 2 (ACM2)] and two local turbulence kinetic energy closures [Mellor-Yamada-Janjic (MYJ), Bougeault-Lacarrere (BouLac)] are evaluated in simulating planetary boundary layer (PBL) parameters and thermodynamic structure of the atmosphere. The model-simulated parameters are validated with available in situ meteorological observations obtained from micro-meteorological tower as well has high-resolution DigiCORA radiosonde ascents during STORM-2007 field experiment at the study location and Doppler Weather Radar (DWR) imageries. It has been found that the PBL structure simulated with the TKE closures MYJ and BouLac are in better agreement with observations than the non-local closures. The model simulations with these schemes also captured the reflectivity, surface pressure patterns such as wake-low, meso-high, pre-squall low and the convective updrafts and downdrafts reasonably well. Qualitative and quantitative comparisons reveal that the MYJ followed by BouLac schemes better simulated various features of the thunderstorm events over Kharagpur region. The better performance of MYJ followed by BouLac is evident in the lesser mean bias, mean absolute error, root mean square error and good correlation coefficient for various surface meteorological variables as well as thermo-dynamical structure of the atmosphere relative to other PBL schemes. The better performance of the TKE closures may be attributed to their higher mixing efficiency, larger convective energy and better simulation of humidity promoting moist convection relative to non

  2. INTEGRATED WATER TREATMENT SYSTEM PERFORMANCE EVALUATION

    SciTech Connect

    SEXTON RA; MEEUWSEN WE

    2009-03-12

    This document describes the results of an evaluation of the current Integrated Water Treatment System (IWTS) operation against design performance and a determination of short term and long term actions recommended to sustain IWTS performance.

  3. Robotic Manipulator Control Performance Evaluation.

    DTIC Science & Technology

    1986-08-01

    compensation of a PUMA was addressed and Backes, Leininger and Chung [5], and Zhang and Paul 11111 model friction in an identical fashion. Also at that...1237- 42, June 6-8, 1984. 5. Backes, P. G., Leininger , G. G. and Chung, C., "Real- Time Cartesian Coordinate Hybrid Control of a PUMA 560...Manipulators," Report RSD- TR-10-82, University of Michigan College of Engineering at Ann Arbor, August 1982. 15. Chung, C. H. and Leininger , G., "Adaptive

  4. S-191 sensor performance evaluation

    NASA Technical Reports Server (NTRS)

    Hughes, C. L.

    1975-01-01

    A final analysis was performed on the Skylab S-191 spectrometer data received from missions SL-2, SL-3, and SL-4. The repeatability and accuracy of the S-191 spectroradiometric internal calibration was determined by correlation to the output obtained from well-defined external targets. These included targets on the moon and earth as well as deep space. In addition, the accuracy of the S-191 short wavelength autocalibration was flight checked by correlation of the earth resources experimental package S-191 outputs and the Backup Unit S-191 outputs after viewing selected targets on the moon.

  5. Evaluation of the performance of SiBcrop model in predicting carbon fluxes and crop yields in the croplands of the US mid continental region

    NASA Astrophysics Data System (ADS)

    Lokupitiya, E.; Denning, S.; Paustian, K.; Corbin, K.; Baker, I.; Schaefer, K.

    2008-12-01

    The accurate representation of phenology, physiology, and major crop variables is important in the land- atmosphere carbon models being used to predict carbon and other exchanges of the man-made cropland ecosystems. We evaluated the performance of SiBcrop model (which is the Simple Biosphere model (SiB) with a new scheme for crop phenology and physiology) in predicting carbon exchanges of the US mid continental region which has several major crops. The use of the new phenology scheme within SiB remarkably improved the prediction of LAI and carbon fluxes for corn, soybean, and wheat crops as compared with the observed data at several Ameriflux eddy covariance flux tower sites with those crops. SiBcrop better predicted the onset and end of the growing season, harvest, interannual variability associated with crop rotation, day time carbon draw down, and day to day variability in the carbon exchanges. The model has been coupled with RAMS, the regional Atmospheric Modeling System (developed at Colorado State University), and the coupled SiBcrop-RAMS has predicted better carbon and other fluxes compared to the original SiB-RAMS. SiBcrop also predicted daily variation in biomass in different plant pools (i.e. roots, leaves, stems, and products). In this study, we further evaluated the performance of SiBcrop by comparing the yield estimates based on the grain/seed biomass at harvest predicted by SiBcrop for relevant major crops, against the county-level crop yields reported by the US National Agricultural Statistics Service (NASS). Initially, the model runs were based on crop maps scaled at 40 km resolution; the maps were used to derive the fraction of corn, soybean, and wheat at each grid cell across the US Mid Continental Intensive (MCI) region under the North American Carbon Program (NACP). The yield biomass carbon values (at harvest) predicted for each grid cell by SiBcrop were extrapolated to derive the county-level yield biomass carbon values, which were then

  6. Performance Evaluation of the SPT-140

    NASA Technical Reports Server (NTRS)

    Manzella, David; Sarmiento, Charles; Sankovic, John; Haag, Tom

    1997-01-01

    As part of an on-going cooperative program with industry, an engineering model SPT-140 Hall thruster, which may be suitable for orbit insertion and station-keeping of geosynchronous communication satellites, was evaluated with respect to thrust and radiated electromagnetic interference at the NASA Lewis Research Center. Performance measurements were made using a laboratory model propellant feed system and commercial power supplies. The engine was operated in a space simulation chamber capable of providing background pressures of 4 x 10(exp -6) Torr or less during thruster operation. Thrust was measured at input powers ranging from 1.5 to 5 kilowatts with two different output filter configurations. The broadband electromagnetic emission spectra generated by the engine was also measured for a range of frequencies from 0.01 to 18,000 Mhz. These results are compared to the noise threshold of the measurement system and MIL-STD-461C where appropriate.

  7. Pragmatic geometric model evaluation

    NASA Astrophysics Data System (ADS)

    Pamer, Robert

    2015-04-01

    Quantification of subsurface model reliability is mathematically and technically demanding as there are many different sources of uncertainty and some of the factors can be assessed merely in a subjective way. For many practical applications in industry or risk assessment (e. g. geothermal drilling) a quantitative estimation of possible geometric variations in depth unit is preferred over relative numbers because of cost calculations for different scenarios. The talk gives an overview of several factors that affect the geometry of structural subsurface models that are based upon typical geological survey organization (GSO) data like geological maps, borehole data and conceptually driven construction of subsurface elements (e. g. fault network). Within the context of the trans-European project "GeoMol" uncertainty analysis has to be very pragmatic also because of different data rights, data policies and modelling software between the project partners. In a case study a two-step evaluation methodology for geometric subsurface model uncertainty is being developed. In a first step several models of the same volume of interest have been calculated by omitting successively more and more input data types (seismic constraints, fault network, outcrop data). The positions of the various horizon surfaces are then compared. The procedure is equivalent to comparing data of various levels of detail and therefore structural complexity. This gives a measure of the structural significance of each data set in space and as a consequence areas of geometric complexity are identified. These areas are usually very data sensitive hence geometric variability in between individual data points in these areas is higher than in areas of low structural complexity. Instead of calculating a multitude of different models by varying some input data or parameters as it is done by Monte-Carlo-simulations, the aim of the second step of the evaluation procedure (which is part of the ongoing work) is to

  8. A bivariate measurement error model for nitrogen and potassium intakes to evaluate the performance of regression calibration in the European Prospective Investigation into Cancer and Nutrition study.

    PubMed

    Ferrari, P; Roddam, A; Fahey, M T; Jenab, M; Bamia, C; Ocké, M; Amiano, P; Hjartåker, A; Biessy, C; Rinaldi, S; Huybrechts, I; Tjønneland, A; Dethlefsen, C; Niravong, M; Clavel-Chapelon, F; Linseisen, J; Boeing, H; Oikonomou, E; Orfanos, P; Palli, D; Santucci de Magistris, M; Bueno-de-Mesquita, H B; Peeters, P H M; Parr, C L; Braaten, T; Dorronsoro, M; Berenguer, T; Gullberg, B; Johansson, I; Welch, A A; Riboli, E; Bingham, S; Slimani, N

    2009-11-01

    Within the European Prospective Investigation into Cancer and Nutrition (EPIC) study, the performance of 24-h dietary recall (24-HDR) measurements as reference measurements in a linear regression calibration model is evaluated critically at the individual (within-centre) and aggregate (between-centre) levels by using unbiased estimates of urinary measurements of nitrogen and potassium intakes. Between 1995 and 1999, 1072 study subjects (59% women) from 12 EPIC centres volunteered to collect 24-h urine samples. Log-transformed questionnaire, 24-HDR and urinary measurements of nitrogen and potassium intakes were analysed in a multivariate measurement error model to estimate the validity of coefficients and error correlations in self-reported dietary measurements. In parallel, correlations between means of 24-HDR and urinary measurements were computed. Linear regression calibration models were used to estimate the regression dilution (attenuation) factors. After adjustment for sex, centre, age, body mass index and height, the validity coefficients for 24-HDRs were 0.285 (95% confidence interval: 0.194, 0.367) and 0.371 (0.291, 0.446) for nitrogen and potassium intakes, respectively. The attenuation factors estimated in a linear regression calibration model were 0.368 (0.228, 0.508) for nitrogen and 0.500 (0.361, 0.639) for potassium intakes; only the former was different from the estimate obtained using urinary measurements in the measurement error model. The aggregate-level correlation coefficients between means of urinary and 24-HDR measurements were 0.838 (0.637, 0.932) and 0.756 (0.481, 0.895) for nitrogen and potassium intakes, respectively. This study suggests that 24-HDRs can be used as reference measurements at the individual and aggregate levels for potassium intake, whereas, for nitrogen intake, good performance is observed for between-centre calibration, but some limitations are apparent at the individual level.

  9. Performance evaluation and modeling of a submerged membrane bioreactor treating combined municipal and industrial wastewater using radial basis function artificial neural networks.

    PubMed

    Mirbagheri, Seyed Ahmad; Bagheri, Majid; Boudaghpour, Siamak; Ehteshami, Majid; Bagheri, Zahra

    2015-01-01

    Treatment process models are efficient tools to assure proper operation and better control of wastewater treatment systems. The current research was an effort to evaluate performance of a submerged membrane bioreactor (SMBR) treating combined municipal and industrial wastewater and to simulate effluent quality parameters of the SMBR using a radial basis function artificial neural network (RBFANN). The results showed that the treatment efficiencies increase and hydraulic retention time (HRT) decreases for combined wastewater compared with municipal and industrial wastewaters. The BOD, COD, [Formula: see text] and total phosphorous (TP) removal efficiencies for combined wastewater at HRT of 7 hours were 96.9%, 96%, 96.7% and 92%, respectively. As desirable criteria for treating wastewater, the TBOD/TP ratio increased, the BOD and COD concentrations decreased to 700 and 1000 mg/L, respectively and the BOD/COD ratio was about 0.5 for combined wastewater. The training procedures of the RBFANN models were successful for all predicted components. The train and test models showed an almost perfect match between the experimental and predicted values of effluent BOD, COD, [Formula: see text] and TP. The coefficient of determination (R(2)) values were higher than 0.98 and root mean squared error (RMSE) values did not exceed 7% for train and test models.

  10. Colorimetric evaluation of display performance

    NASA Astrophysics Data System (ADS)

    Kosmowski, Bogdan B.

    2001-08-01

    The development of information techniques, using new technologies, physical phenomena and coding schemes, enables new application areas to be benefited form the introduction of displays. The full utilization of the visual perception of a human operator, requires the color coding process to be implemented. The evolution of displays, from achromatic (B&W) and monochromatic, to multicolor and full-color, enhances the possibilities of information coding, creating however a need for the quantitative methods of display parameter assessment. Quantitative assessment of color displays, restricted to photometric measurements of their parameters, is an estimate leading to considerable errors. Therefore, the measurements of a display's color properties have to be based on spectral measurements of the display and its elements. The quantitative assessment of the display system parameters should be made using colorimetric systems like CIE1931, CIE1976 LAB or LUV. In the paper, the constraints on the measurement method selection for the color display evaluation are discussed and the relations between their qualitative assessment and the ergonomic conditions of their application are also presented. The paper presents the examples of using LUV colorimetric system and color difference (Delta) E in the optimization of color liquid crystal displays.

  11. Evaluating iterative reconstruction performance in computed tomography

    SciTech Connect

    Chen, Baiyu Solomon, Justin; Ramirez Giraldo, Juan Carlos; Samei, Ehsan

    2014-12-15

    Purpose: Iterative reconstruction (IR) offers notable advantages in computed tomography (CT). However, its performance characterization is complicated by its potentially nonlinear behavior, impacting performance in terms of specific tasks. This study aimed to evaluate the performance of IR with both task-specific and task-generic strategies. Methods: The performance of IR in CT was mathematically assessed with an observer model that predicted the detection accuracy in terms of the detectability index (d′). d′ was calculated based on the properties of the image noise and resolution, the observer, and the detection task. The characterizations of image noise and resolution were extended to accommodate the nonlinearity of IR. A library of tasks was mathematically modeled at a range of sizes (radius 1–4 mm), contrast levels (10–100 HU), and edge profiles (sharp and soft). Unique d′ values were calculated for each task with respect to five radiation exposure levels (volume CT dose index, CTDI{sub vol}: 3.4–64.8 mGy) and four reconstruction algorithms (filtered backprojection reconstruction, FBP; iterative reconstruction in imaging space, IRIS; and sinogram affirmed iterative reconstruction with strengths of 3 and 5, SAFIRE3 and SAFIRE5; all provided by Siemens Healthcare, Forchheim, Germany). The d′ values were translated into the areas under the receiver operating characteristic curve (AUC) to represent human observer performance. For each task and reconstruction algorithm, a threshold dose was derived as the minimum dose required to achieve a threshold AUC of 0.9. A task-specific dose reduction potential of IR was calculated as the difference between the threshold doses for IR and FBP. A task-generic comparison was further made between IR and FBP in terms of the percent of all tasks yielding an AUC higher than the threshold. Results: IR required less dose than FBP to achieve the threshold AUC. In general, SAFIRE5 showed the most significant dose reduction

  12. Evaluating iterative reconstruction performance in computed tomography.

    PubMed

    Chen, Baiyu; Ramirez Giraldo, Juan Carlos; Solomon, Justin; Samei, Ehsan

    2014-12-01

    Iterative reconstruction (IR) offers notable advantages in computed tomography (CT). However, its performance characterization is complicated by its potentially nonlinear behavior, impacting performance in terms of specific tasks. This study aimed to evaluate the performance of IR with both task-specific and task-generic strategies. The performance of IR in CT was mathematically assessed with an observer model that predicted the detection accuracy in terms of the detectability index (d'). d' was calculated based on the properties of the image noise and resolution, the observer, and the detection task. The characterizations of image noise and resolution were extended to accommodate the nonlinearity of IR. A library of tasks was mathematically modeled at a range of sizes (radius 1-4 mm), contrast levels (10-100 HU), and edge profiles (sharp and soft). Unique d' values were calculated for each task with respect to five radiation exposure levels (volume CT dose index, CTDIvol: 3.4-64.8 mGy) and four reconstruction algorithms (filtered backprojection reconstruction, FBP; iterative reconstruction in imaging space, IRIS; and sinogram affirmed iterative reconstruction with strengths of 3 and 5, SAFIRE3 and SAFIRE5; all provided by Siemens Healthcare, Forchheim, Germany). The d' values were translated into the areas under the receiver operating characteristic curve (AUC) to represent human observer performance. For each task and reconstruction algorithm, a threshold dose was derived as the minimum dose required to achieve a threshold AUC of 0.9. A task-specific dose reduction potential of IR was calculated as the difference between the threshold doses for IR and FBP. A task-generic comparison was further made between IR and FBP in terms of the percent of all tasks yielding an AUC higher than the threshold. IR required less dose than FBP to achieve the threshold AUC. In general, SAFIRE5 showed the most significant dose reduction potentials (11-54 mGy, 77%-84%), followed by

  13. An urban energy performance evaluation system and its computer implementation.

    PubMed

    Wang, Lei; Yuan, Guan; Long, Ruyin; Chen, Hong

    2017-12-15

    To improve the urban environment and effectively reflect and promote urban energy performance, an urban energy performance evaluation system was constructed, thereby strengthening urban environmental management capabilities. From the perspectives of internalization and externalization, a framework of evaluation indicators and key factors that determine urban energy performance and explore the reasons for differences in performance was proposed according to established theory and previous studies. Using the improved stochastic frontier analysis method, an urban energy performance evaluation and factor analysis model was built that brings performance evaluation and factor analysis into the same stage for study. According to data obtained for the Chinese provincial capitals from 2004 to 2013, the coefficients of the evaluation indicators and key factors were calculated by the urban energy performance evaluation and factor analysis model. These coefficients were then used to compile the program file. The urban energy performance evaluation system developed in this study was designed in three parts: a database, a distributed component server, and a human-machine interface. Its functions were designed as login, addition, edit, input, calculation, analysis, comparison, inquiry, and export. On the basis of these contents, an urban energy performance evaluation system was developed using Microsoft Visual Studio .NET 2015. The system can effectively reflect the status of and any changes in urban energy performance. Beijing was considered as an example to conduct an empirical study, which further verified the applicability and convenience of this evaluation system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Laser Plasma Microthruster Performance Evaluation

    NASA Astrophysics Data System (ADS)

    Luke, James R.; Phipps, Claude R.

    2003-05-01

    The micro laser plasma thruster (μLPT) is a sub-kilogram thruster that is capable of meeting the Air Force requirements for the Attitude Control System on a 100-kg class small satellite. The μLPT uses one or more 4W diode lasers to ablate a solid fuel, producing a jet of hot gas or plasma which creates thrust with a high thrust/power ratio. A pre-prototype continuous thrust experiment has been constructed and tested. The continuous thrust experiment uses a 505 mm long continuous loop fuel tape, which consists of a black laser-absorbing fuel material on a transparent plastic substrate. When the laser is operated continuously, the exhaust plume and thrust vector are steered in the direction of the tape motion. Thrust steering can be avoided by pulsing the laser. A torsion pendulum thrust stand has been constructed and calibrated. Many fuel materials and substrates have been tested. Best performance from a non-energetic fuel material was obtained with black polyvinyl chloride (PVC), which produced an average of 70 μN thrust and coupling coefficient (Cm) of 190 μN/W. A proprietary energetic material was also tested, in which the laser initiates a non-propagating detonation. This material produced 500 μN of thrust.

  15. Towards Systematic Benchmarking of Climate Model Performance

    NASA Astrophysics Data System (ADS)

    Gleckler, P. J.

    2014-12-01

    The process by which climate models are evaluated has evolved substantially over the past decade, with the Coupled Model Intercomparison Project (CMIP) serving as a centralizing activity for coordinating model experimentation and enabling research. Scientists with a broad spectrum of expertise have contributed to the CMIP model evaluation process, resulting in many hundreds of publications that have served as a key resource for the IPCC process. For several reasons, efforts are now underway to further systematize some aspects of the model evaluation process. First, some model evaluation can now be considered routine and should not require "re-inventing the wheel" or a journal publication simply to update results with newer models. Second, the benefit of CMIP research to model development has not been optimal because the publication of results generally takes several years and is usually not reproducible for benchmarking newer model versions. And third, there are now hundreds of model versions and many thousands of simulations, but there is no community-based mechanism for routinely monitoring model performance changes. An important change in the design of CMIP6 can help address these limitations. CMIP6 will include a small set standardized experiments as an ongoing exercise (CMIP "DECK": ongoing Diagnostic, Evaluation and Characterization of Klima), so that modeling groups can submit them at any time and not be overly constrained by deadlines. In this presentation, efforts to establish routine benchmarking of existing and future CMIP simulations will be described. To date, some benchmarking tools have been made available to all CMIP modeling groups to enable them to readily compare with CMIP5 simulations during the model development process. A natural extension of this effort is to make results from all CMIP simulations widely available, including the results from newer models as soon as the simulations become available for research. Making the results from routine

  16. Using the Many-Facet Rasch Model to Evaluate Standard-Setting Judgments: Setting Performance Standards for Advanced Placement® Examinations

    ERIC Educational Resources Information Center

    Kaliski, Pamela; Wind, Stefanie A.; Engelhard, George, Jr.; Morgan, Deanna; Plake, Barbara; Reshetar, Rosemary

    2012-01-01

    The Many-Facet Rasch (MFR) Model is traditionally used to evaluate the quality of ratings on constructed response assessments; however, it can also be used to evaluate the quality of judgments from panel-based standard setting procedures. The current study illustrates the use of the MFR Model by examining the quality of ratings obtained from a…

  17. Performance evaluation of a non-hydrostatic regional climate model over the Mediterranean/Black Sea area and climate projections for the XXI century

    NASA Astrophysics Data System (ADS)

    Mercogliano, Paola; Bucchignani, Edoardo; Montesarchio, Myriam; Zollo, Alessandra Lucia

    2013-04-01

    In the framework of the Work Package 4 (Developing integrated tools for environmental assessment) of PERSEUS Project, high resolution climate simulations have been performed, with the aim of furthering knowledge in the field of climate variability at regional scale, its causes and impacts. CMCC is a no profit centre whose aims are the promotion, research coordination and scientific activities in the field of climate changes. In this work, we show results of numerical simulation performed over a very wide area (13W-46E; 29-56N) at spatial resolution of 14 km, which includes the Mediterranean and Black Seas, using the regional climate model COSMO-CLM. It is a non-hydrostatic model for the simulation of atmospheric processes, developed by the DWD-Germany for weather forecast services; successively, the model has been updated by the CLM-Community, in order to develop climatic applications. It is the only documented numerical model system in Europe designed for spatial resolutions down to 1 km with a range of applicability encompassing operational numerical weather prediction, regional climate modelling the dispersion of trace gases and aerosol and idealised studies and applicable in all regions of the world for a wide range of available climate simulations from global climate and NWP models. Different reasons justify the development of a regional model: the first is the increasing number of works in literature asserting that regional models have also the features to provide more detailed description of the climate extremes, that are often more important then their mean values for natural and human systems. The second one is that high resolution modelling shows adequate features to provide information for impact assessment studies. At CMCC, regional climate modelling is a part of an integrated simulation system and it has been used in different European and African projects to provide qualitative and quantitative evaluation of the hydrogeological and public health risks

  18. Evaluation of performance of bacterial culture of feces and serum ELISA across stages of Johne's disease in cattle using a Bayesian latent class model.

    PubMed

    Espejo, L A; Zagmutt, F J; Groenendaal, H; Muñoz-Zanzi, C; Wells, S J

    2015-11-01

    The objective of this study was to evaluate the performance of bacterial culture of feces and serum ELISA to correctly identify cows with Mycobacterium avium ssp. paratuberculosis (MAP) at heavy, light, and non-fecal-shedding levels. A total of 29,785 parallel test results from bacterial culture of feces and serum ELISA were collected from 17 dairy herds in Minnesota, Pennsylvania, and Colorado. Samples were obtained from adult cows from dairy herds enrolled for up to 10 yr in the National Johne's Disease Demonstration Herd Project. A Bayesian latent class model was fitted to estimate the probabilities that bacterial culture of feces (using 72-h sedimentation or 30-min centrifugation methods) and serum ELISA results correctly identified cows as high positive, low positive, or negative given that cows were heavy, light, and non-shedders, respectively. The model assumed that no gold standard test was available and conditional independency existed between diagnostic tests. The estimated conditional probabilities that bacterial culture of feces correctly identified heavy shedders, light shedders, and non-shedders were 70.9, 32.0, and 98.5%, respectively. The same values for the serum ELISA were 60.6, 18.7, and 99.5%, respectively. Differences in diagnostic test performance were observed among states. These results improve the interpretation of results from bacterial culture of feces and serum ELISA for detection of MAP and MAP antibody (respectively), which can support on-farm infection control decisions and can be used to evaluate disease-testing strategies, taking into account the accuracy of these tests.

  19. Theory and Practice on Teacher Performance Evaluation

    ERIC Educational Resources Information Center

    Yonghong, Cai; Chongde, Lin

    2006-01-01

    Teacher performance evaluation plays a key role in educational personnel reform, so it has been an important yet difficult issue in educational reform. Previous evaluations on teachers failed to make strict distinction among the three dominant types of evaluation, namely, capability, achievement, and effectiveness. Moreover, teacher performance…

  20. Using Business Performance To Evaluate Multimedia Training in Manufacturing.

    ERIC Educational Resources Information Center

    Lachenmaier, Lynn S.; Moor, William C.

    1997-01-01

    Discusses training evaluation and shows how an abbreviated form of Kirkpatrick's four-level evaluation model can be used effectively to evaluate multimedia-based manufacturing training. Topics include trends in manufacturing training, quantifying performance improvement, and statistical comparisons using the Mann-Whitney test and the Tukey Quick…

  1. Modeling and simulation of biopharmaceutical performance.

    PubMed

    Zhang, X; Lionberger, R A

    2014-05-01

    Biopharmaceutical performance refers to the influence of pharmaceutical formulation variables on in vivo performance. New drug product success depends on formulation design for sufficient bioavailability for clinically desired dosing. Regulatory interest in biopharmaceutical performance includes batch-to-batch consistency, acceptability of postapproval changes, and evaluation of bioequivalence (BE) for generic drug products. This Commentary summarizes biopharmaceutical modeling and simulation in the US Food and Drug Administration (FDA) Office of Generic Drugs (OGD) for orally administered generic drugs.

  2. Performance of Information Criteria for Spatial Models.

    PubMed

    Lee, Hyeyoung; Ghosh, Sujit K

    2009-01-01

    Model choice is one of the most crucial aspect in any statistical data analysis. It is well known that most models are just an approximation to the true data generating process but among such model approximations it is our goal to select the "best" one. Researchers typically consider a finite number of plausible models in statistical applications and the related statistical inference depends on the chosen model. Hence model comparison is required to identify the "best" model among several such candidate models. This article considers the problem of model selection for spatial data. The issue of model selection for spatial models has been addressed in the literature by the use of traditional information criteria based methods, even though such criteria have been developed based on the assumption of independent observations. We evaluate the performance of some of the popular model selection critera via Monte Carlo simulation experiments using small to moderate samples. In particular, we compare the performance of some of the most popular information criteria such as Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC), and Corrected AIC (AICc) in selecting the true model. The ability of these criteria to select the correct model is evaluated under several scenarios. This comparison is made using various spatial covariance models ranging from stationary isotropic to nonstationary models.

  3. Validation of performance assessment models

    SciTech Connect

    Bergeron, M.P.; Kincaid, C.T.

    1991-11-01

    The purpose of model validation in a low-level waste site performance assessment is to increase confidence in predictions of the migration and fate of future releases from the wastes. Unlike the process of computer code verification, model validation is a site-specific process that requires site-specific data. This paper provides an overview of the topic of model validation and describes the general approaches, strategies, and limitations of model validation being considered by various researchers concerned with the subject.

  4. Performance Evaluation of Emerging High Performance Computing Technologies using WRF

    NASA Astrophysics Data System (ADS)

    Newby, G. B.; Morton, D.

    2008-12-01

    The Arctic Region Supercomputing Center (ARSC) has evaluated multicore processors and other emerging processor technologies for a variety of high performance computing applications in the earth and space sciences, especially climate and weather applications. A flagship effort has been to assess dual core processor nodes on ARSC's Midnight supercomputer, in which two-socket systems were compared to eight-socket systems. Midnight is utilized for ARSC's twice-daily weather research and forecasting (WRF) model runs, available at weather.arsc.edu. Among other findings on Midnight, it was found that the Hypertransport system for interconnecting Opteron processors, memory, and other subsystems does not scale as well on eight-socket (sixteen processor) systems as well as two-socket (four processor) systems. A fundamental limitation is the cache snooping operation performed whenever a computational thread accesses main memory. This increases memory latency as the number of processor sockets increases. This is particularly noticeable on applications such as WRF that are primarily CPU-bound, versus applications that are bound by input/output or communication. The new Cray XT5 supercomputer at ARSC features quad core processors, and will host a variety of scaling experiments for WRF, CCSM4, and other models. Early results will be presented, including a series of WRF runs for Alaska with grid resolutions under 2km. ARSC will discuss a set of standardized test cases for the Alaska domain, similar to existing test cases for CONUS. These test cases will provide different configuration sizes and resolutions, suitable for single processors up to thousands. Beyond multi-core Opteron-based supercomputers, ARSC has examined WRF and other applications on additional emerging technologies. One such technology is the graphics processing unit, or GPU. The 9800-series nVidia GPU was evaluated with the cuBLAS software library. While in-socket GPUs might be forthcoming in the future, current

  5. Evaluation and Specification of Instructional Materials and Management Procedures through Use of a Pupil Performance Profile and a Predictive Model. Final Report.

    ERIC Educational Resources Information Center

    Haring, Norris G.; Berman, Mark L.

    Reported project objectives were to develop a pupil performance profile which describes the effects of specific instructional materials and management procedures on student performance and to develop a model which predicts pupil performance in a given set of materials under particular conditions. Instructional materials (Mathematics, M.W.…

  6. BioVapor Model Evaluation

    EPA Science Inventory

    General background on modeling and specifics of modeling vapor intrusion are given. Three classical model applications are described and related to the problem of petroleum vapor intrusion. These indicate the need for model calibration and uncertainty analysis. Evaluation of Bi...

  7. BioVapor Model Evaluation

    EPA Science Inventory

    General background on modeling and specifics of modeling vapor intrusion are given. Three classical model applications are described and related to the problem of petroleum vapor intrusion. These indicate the need for model calibration and uncertainty analysis. Evaluation of Bi...

  8. LANDSAT-4 horizon scanner performance evaluation

    NASA Technical Reports Server (NTRS)

    Bilanow, S.; Chen, L. C.; Davis, W. M.; Stanley, J. P.

    1984-01-01

    Representative data spans covering a little more than a year since the LANDSAT-4 launch were analyzed to evaluate the flight performance of the satellite's horizon scanner. High frequency noise was filtered out by 128-point averaging. The effects of Earth oblateness and spacecraft altitude variations are modeled, and residual systematic errors are analyzed. A model for the predicted radiance effects is compared with the flight data and deficiencies in the radiance effects modeling are noted. Correction coefficients are provided for a finite Fourier series representation of the systematic errors in the data. Analysis of the seasonal dependence of the coefficients indicates the effects of some early mission problems with the reference attitudes which were computed by the onboard computer using star trackers and gyro data. The effects of sun and moon interference, unexplained anomalies in the data, and sensor noise characteristics and their power spectrum are described. The variability of full orbit data averages is shown. Plots of the sensor data for all the available data spans are included.

  9. Evaluating the performance of coupled snow-soil models in SURFEXv8 to simulate the permafrost thermal regime at a high Arctic site

    NASA Astrophysics Data System (ADS)

    Barrere, Mathieu; Domine, Florent; Decharme, Bertrand; Morin, Samuel; Vionnet, Vincent; Lafaysse, Matthieu

    2017-09-01

    Climate change projections still suffer from a limited representation of the permafrost-carbon feedback. Predicting the response of permafrost temperature to climate change requires accurate simulations of Arctic snow and soil properties. This study assesses the capacity of the coupled land surface and snow models ISBA-Crocus and ISBA-ES to simulate snow and soil properties at Bylot Island, a high Arctic site. Field measurements complemented with ERA-Interim reanalyses were used to drive the models and to evaluate simulation outputs. Snow height, density, temperature, thermal conductivity and thermal insulance are examined to determine the critical variables involved in the soil and snow thermal regime. Simulated soil properties are compared to measurements of thermal conductivity, temperature and water content. The simulated snow density profiles are unrealistic, which is most likely caused by the lack of representation in snow models of the upward water vapor fluxes generated by the strong temperature gradients within the snowpack. The resulting vertical profiles of thermal conductivity are inverted compared to observations, with high simulated values at the bottom of the snowpack. Still, ISBA-Crocus manages to successfully simulate the soil temperature in winter. Results are satisfactory in summer, but the temperature of the top soil could be better reproduced by adequately representing surface organic layers, i.e., mosses and litter, and in particular their water retention capacity. Transition periods (soil freezing and thawing) are the least well reproduced because the high basal snow thermal conductivity induces an excessively rapid heat transfer between the soil and the snow in simulations. Hence, global climate models should carefully consider Arctic snow thermal properties, and especially the thermal conductivity of the basal snow layer, to perform accurate predictions of the permafrost evolution under climate change.

  10. Actinide Sorption in a Brine/Dolomite Rock System: Evaluating the Degree of Conservatism in Kd Ranges used in Performance Assessment Modeling for the WIPP Nuclear Waste Repository

    NASA Astrophysics Data System (ADS)

    Dittrich, T. M.; Reed, D. T.

    2015-12-01

    The Waste Isolation Pilot Plant (WIPP) near Carlsbad, NM is the only operating nuclear waste repository in the US and has been accepting transuranic (TRU) waste since 1999. The WIPP is located in a salt deposit approximately 650 m below the surface and performance assessment (PA) modeling for a 10,000 year period is required to recertify the operating license with the US EPA every five years. The main pathway of concern for environmental release of radioactivity is a human intrusion caused by drilling into a pressurized brine reservoir below the repository. This could result in the flooding of the repository and subsequent transport in the high transmissivity layer (dolomite-rich Culebra formation) above the waste disposal rooms. We evaluate the degree of conservatism in the estimated sorption partition coefficients (Kds) ranges used in the PA based on an approach developed with granite rock and actinides (Dittrich and Reimus, 2015; Dittrich et al., 2015). Sorption onto the waste storage material (Fe drums) may also play a role in mobile actinide concentrations. We will present (1) a conceptual overview of how Kds are used in the PA model, (2) technical background of the evolution of the ranges and (3) results from batch and column experiments and model predictions for Kds with WIPP dolomite and clays, brine with various actinides, and ligands (e.g., acetate, citrate, EDTA) that could promote transport. The current Kd ranges used in performance models are based on oxidation state and are 5-400, 0.5-10,000, 0.03-200, and 0.03-20 mL g-1 for elements with oxidation states of III, IV, V, and VI, respectively. Based on redox conditions predicted in the brines, possible actinide species include Pu(III), Pu(IV), U(IV), U(VI), Np(IV), Np(V), Am(III), and Th(IV). We will also discuss the challenges of upscaling from lab experiments to field scale predictions, the role of colloids, and the effect of engineered barrier materials (e.g., MgO) on transport conditions. Dittrich

  11. Conductor gestures influence evaluations of ensemble performance

    PubMed Central

    Morrison, Steven J.; Price, Harry E.; Smedley, Eric M.; Meals, Cory D.

    2014-01-01

    Previous research has found that listener evaluations of ensemble performances vary depending on the expressivity of the conductor’s gestures, even when performances are otherwise identical. It was the purpose of the present study to test whether this effect of visual information was evident in the evaluation of specific aspects of ensemble performance: articulation and dynamics. We constructed a set of 32 music performances that combined auditory and visual information and were designed to feature a high degree of contrast along one of two target characteristics: articulation and dynamics. We paired each of four music excerpts recorded by a chamber ensemble in both a high- and low-contrast condition with video of four conductors demonstrating high- and low-contrast gesture specifically appropriate to either articulation or dynamics. Using one of two equivalent test forms, college music majors and non-majors (N = 285) viewed sixteen 30 s performances and evaluated the quality of the ensemble’s articulation, dynamics, technique, and tempo along with overall expressivity. Results showed significantly higher evaluations for performances featuring high rather than low conducting expressivity regardless of the ensemble’s performance quality. Evaluations for both articulation and dynamics were strongly and positively correlated with evaluations of overall ensemble expressivity. PMID:25104944

  12. Performance Evaluation of Undulator Radiation at CEBAF

    SciTech Connect

    Chuyu Liu, Geoffrey Krafft, Guimei Wang

    2010-05-01

    The performance of undulator radiation (UR) at CEBAF with a 3.5 m helical undulator is evaluated and compared with APS undulator-A radiation in terms of brilliance, peak brilliance, spectral flux, flux density and intensity distribution.

  13. Nickel cadmium battery performance modelling

    NASA Technical Reports Server (NTRS)

    Clark, K.; Halpert, G.; Timmerman, P.

    1989-01-01

    The development of a model to predict cell/battery behavior given databases of temperature is described. The model accommodates batteries of various structural as well as thermal designs. Cell internal design modifications can be accommodated as long as the databases reflect the cell's performance characteristics. Operational parameters can be varied to simulate any number of charge or discharge methods under any orbital regime. The flexibility of the model stems from the broad scope of input variables and allows the prediction of battery performance under simulated mission or test conditions.

  14. Evaluation Theory, Models, and Applications

    ERIC Educational Resources Information Center

    Stufflebeam, Daniel L.; Shinkfield, Anthony J.

    2007-01-01

    "Evaluation Theory, Models, and Applications" is designed for evaluators and students who need to develop a commanding knowledge of the evaluation field: its history, theory and standards, models and approaches, procedures, and inclusion of personnel as well as program evaluation. This important book shows how to choose from a growing…

  15. Improvement of Automotive Part Supplier Performance Evaluation

    NASA Astrophysics Data System (ADS)

    Kongmunee, Chalermkwan; Chutima, Parames

    2016-05-01

    This research investigates the problem of the part supplier performance evaluation in a major Japanese automotive plant in Thailand. Its current evaluation scheme is based on experiences and self-opinion of the evaluators. As a result, many poor performance suppliers are still considered as good suppliers and allow to supply parts to the plant without further improvement obligation. To alleviate this problem, the brainstorming session among stakeholders and evaluators are formally conducted. The result of which is the appropriate evaluation criteria and sub-criteria. The analytical hierarchy process is also used to find suitable weights for each criteria and sub-criteria. The results show that a newly developed evaluation method is significantly better than the previous one in segregating between good and poor suppliers.

  16. Evaluation of high-performance computing software

    SciTech Connect

    Browne, S.; Dongarra, J.; Rowan, T.

    1996-12-31

    The absence of unbiased and up to date comparative evaluations of high-performance computing software complicates a user`s search for the appropriate software package. The National HPCC Software Exchange (NHSE) is attacking this problem using an approach that includes independent evaluations of software, incorporation of author and user feedback into the evaluations, and Web access to the evaluations. We are applying this approach to the Parallel Tools Library (PTLIB), a new software repository for parallel systems software and tools, and HPC-Netlib, a high performance branch of the Netlib mathematical software repository. Updating the evaluations with feed-back and making it available via the Web helps ensure accuracy and timeliness, and using independent reviewers produces unbiased comparative evaluations difficult to find elsewhere.

  17. EVALUATION OF THE COMMUNITY MULTISCALE AIR QUALITY (CMAQ) MODEL VERSION 4.5: UNCERTAINTIES AND SENSITIVITIES IMPACTING MODEL PERFORMANCE: PART I - OZONE

    EPA Science Inventory

    This study examines ozone (O3) predictions from the Community Multiscale Air Quality (CMAQ) model version 4.5 and discusses potential factors influencing the model results. Daily maximum 8-hr average O3 levels are largely underpredicted when observed O...

  18. EVALUATION OF THE COMMUNITY MULTISCALE AIR QUALITY (CMAQ) MODEL VERSION 4.5: UNCERTAINTIES AND SENSITIVITIES IMPACTING MODEL PERFORMANCE: PART I - OZONE

    EPA Science Inventory

    This study examines ozone (O3) predictions from the Community Multiscale Air Quality (CMAQ) model version 4.5 and discusses potential factors influencing the model results. Daily maximum 8-hr average O3 levels are largely underpredicted when observed O...

  19. Assessment beyond Performance: Phenomenography in Educational Evaluation

    ERIC Educational Resources Information Center

    Micari, Marina; Light, Gregory; Calkins, Susanna; Streitwieser, Bernhard

    2007-01-01

    Increasing calls for accountability in education have promoted improvements in quantitative evaluation approaches that measure student performance; however, this has often been to the detriment of qualitative approaches, reducing the richness of educational evaluation as an enterprise. In this article the authors assert that it is not merely…

  20. Building Leadership Talent through Performance Evaluation

    ERIC Educational Resources Information Center

    Clifford, Matthew

    2015-01-01

    Most states and districts scramble to provide professional development to support principals, but "principal evaluation" is often lost amid competing priorities. Evaluation is an important method for supporting principal growth, communicating performance expectations to principals, and improving leadership practice. It provides leaders…

  1. Neglected Areas in Evaluating Writing Performance.

    ERIC Educational Resources Information Center

    Keech, Catharine Lucas

    The heavy concentration of time and funds to measure writing performance is the major reason other areas deserving scrutiny are so often neglected by evaluators. Three failings typical of the field of writing assessment as it is conducted for the purpose of program evaluation are: (1) a failure to view writing as a multiple construct; (2) a…

  2. Reference Service Standards, Performance Criteria, and Evaluation.

    ERIC Educational Resources Information Center

    Schwartz, Diane G.; Eakin, Dottie

    1986-01-01

    Describes process by which reference service standards were developed at a university medical library and their impact on the evaluation of work of librarians. Highlights include establishment of preliminary criteria, literature review, reference service standards, performance evaluation, peer review, and staff development. Checklist of reference…

  3. Automatic Singing Performance Evaluation for Untrained Singers

    NASA Astrophysics Data System (ADS)

    Cao, Chuan; Li, Ming; Wu, Xiao; Suo, Hongbin; Liu, Jian; Yan, Yonghong

    In this letter, we present an automatic approach of objective singing performance evaluation for untrained singers by relating acoustic measurements to perceptual ratings of singing voice quality. Several acoustic parameters and their combination features are investigated to find objective correspondences of the perceptual evaluation criteria. Experimental results show relative strong correlation between perceptual ratings and the combined features and the reliability of the proposed evaluation system is tested to be comparable to human judges.

  4. Course Evaluation. II: Interpretation of Student Performance on Evaluative Tests

    ERIC Educational Resources Information Center

    Aikenhead, Glen S.

    1974-01-01

    Reports the results of a comparative evaluation of Harvard Project Physics (HPP) and non-HPP student performance, and demonstrates the ability of a new test construction paradigm to generate valuable feedback for curriculum developers, teachers, and students. (JR)

  5. Modeling road-cycling performance.

    PubMed

    Olds, T S; Norton, K I; Lowe, E L; Olive, S; Reay, F; Ly, S

    1995-04-01

    This paper presents a complete set of equations for a "first principles" mathematical model of road-cycling performance, including corrections for the effect of winds, tire pressure and wheel radius, altitude, relative humidity, rotational kinetic energy, drafting, and changed drag. The relevant physiological, biophysical, and environmental variables were measured in 41 experienced cyclists completing a 26-km road time trial. The correlation between actual and predicted times was 0.89 (P < or = 0.0001), with a mean difference of 0.74 min (1.73% of mean performance time) and a mean absolute difference of 1.65 min (3.87%). Multiple simulations were performed where model inputs were randomly varied using a normal distribution about the measured values with a SD equivalent to the estimated day-to-day variability or technical error of measurement in each of the inputs. This analysis yielded 95% confidence limits for the predicted times. The model suggests that the main physiological factors contributing to road-cycling performance are maximal O2 consumption, fractional utilization of maximal O2 consumption, mechanical efficiency, and projected frontal area. The model is then applied to some practical problems in road cycling: the effect of drafting, the advantage of using smaller front wheels, the effects of added mass, the importance of rotational kinetic energy, the effect of changes in drag due to changes in bicycle configuration, the normalization of performances under different conditions, and the limits of human performance.

  6. An Operational Systems Approach Toward the Evaluation of Library School Faculty: The Fried Transdisciplinary Model of Technological and Social Organization Applied to the Academic Institution's Policies and Practices Related to Faculty Performance and Working Environment.

    ERIC Educational Resources Information Center

    DeHart, Florence E.

    Present evaluation techniques depend heavily upon student input, with little or no reference to the circumstances under which faculty work. Using the Fried Transdisciplinary Model in evaluating faculty would do much to alleviate this situation. Questions about quality of performance would still be considered under the Task Requisites Zone of the…

  7. Principal Performance Areas and Principal Evaluation.

    ERIC Educational Resources Information Center

    Fletcher, Thomas E.; McInerney, William D.

    1995-01-01

    Summarizes a study that surveyed Indiana superintendents and examined their principal-evaluation instruments. Superintendents were asked which of 21 performance domains were most important and whether these were currently being assessed. Respondents generally agreed that all 21 performance domains identified by the National Policy Board for…

  8. Translation from UML to Markov Model: A Performance Modeling Framework

    NASA Astrophysics Data System (ADS)

    Khan, Razib Hayat; Heegaard, Poul E.

    Performance engineering focuses on the quantitative investigation of the behavior of a system during the early phase of the system development life cycle. Bearing this on mind, we delineate a performance modeling framework of the application for communication system that proposes a translation process from high level UML notation to Continuous Time Markov Chain model (CTMC) and solves the model for relevant performance metrics. The framework utilizes UML collaborations, activity diagrams and deployment diagrams to be used for generating performance model for a communication system. The system dynamics will be captured by UML collaboration and activity diagram as reusable specification building blocks, while deployment diagram highlights the components of the system. The collaboration and activity show how reusable building blocks in the form of collaboration can compose together the service components through input and output pin by highlighting the behavior of the components and later a mapping between collaboration and system component identified by deployment diagram will be delineated. Moreover the UML models are annotated to associate performance related quality of service (QoS) information which is necessary for solving the performance model for relevant performance metrics through our proposed framework. The applicability of our proposed performance modeling framework in performance evaluation is delineated in the context of modeling a communication system.

  9. Developing a Computerized Performance Based Curriculum Model.

    ERIC Educational Resources Information Center

    Hagmeier, Jerry; And Others

    In developing a model for institutional assessment, John Wood Community College (JWCC), in Quincy, Illinois, decided to use student learning as the foundation of evaluation, as opposed to the activities and services offered by the college. This performance-based approach to institutional assessment was then expanded to reshape the process by which…

  10. MPD Thruster Performance Analytic Models

    NASA Technical Reports Server (NTRS)

    Gilland, James; Johnston, Geoffrey

    2007-01-01

    Magnetoplasmadynamic (MPD) thrusters are capable of accelerating quasi-neutral plasmas to high exhaust velocities using Megawatts (MW) of electric power. These characteristics make such devices worthy of consideration for demanding, far-term missions such as the human exploration of Mars or beyond. Assessment of MPD thrusters at the system and mission level is often difficult due to their status as ongoing experimental research topics rather than developed thrusters. However, in order to assess MPD thrusters utility in later missions, some adequate characterization of performance, or more exactly, projected performance, and system level definition are required for use in analyses. The most recent physical models of self-field MPD thrusters have been examined, assessed, and reconfigured for use by systems and mission analysts. The physical models allow for rational projections of thruster performance based on physical parameters that can be measured in the laboratory. The models and their implications for the design of future MPD thrusters are presented.

  11. MPD Thruster Performance Analytic Models

    NASA Technical Reports Server (NTRS)

    Gilland, James; Johnston, Geoffrey

    2003-01-01

    Magnetoplasmadynamic (MPD) thrusters are capable of accelerating quasi-neutral plasmas to high exhaust velocities using Megawatts (MW) of electric power. These characteristics make such devices worthy of consideration for demanding, far-term missions such as the human exploration of Mars or beyond. Assessment of MPD thrusters at the system and mission level is often difficult due to their status as ongoing experimental research topics rather than developed thrusters. However, in order to assess MPD thrusters utility in later missions, some adequate characterization of performance, or more exactly, projected performance, and system level definition are required for use in analyses. The most recent physical models of self-field MPD thrusters have been examined, assessed, and reconfigured for use by systems and mission analysts. The physical models allow for rational projections of thruster performance based on physical parameters that can be measured in the laboratory. The models and their implications for the design of future MPD thrusters are presented.

  12. Evaluating the performance of clinical dietitians.

    PubMed

    Gates, G E; Holdt, C S

    1993-05-01

    The purposes of this study were to describe how clinical managers evaluate the performance of clinical dietitians and to examine managers' opinions about performance appraisal. Managers from 55 acute-care hospitals in seven midwestern states responded to a telephone survey about their appraisal of the performance of clinical dietitians. Most of the clinical managers had developed criteria with written standards for evaluating performance. Respondents evaluated the dietitians once a year and relied primarily on chart audits, other work samples, and critical incidents to judge performance. Managers in 32 of the hospitals asked their subordinates to complete a self-appraisal, and almost all of the managers negotiated with the dietitians to identify goals for professional improvement. Respondents' reasons for conducting performance appraisals were indicative of a participative management style. During the interviews, many clinical managers requested help in improving their performance appraisal systems, which suggests a need for additional training in conducting performance appraisals. The findings indicate that most clinical managers were following recommended guidelines for conducting performance appraisals.

  13. Supplier Performance Evaluation and Rating System (SPEARS)

    SciTech Connect

    Oged, M.; Warner, D.; Gurbuz, E.

    1993-03-01

    The SSCL Magnet Quality Assurance Department has implemented a Supplier Performance Evaluation and Rating System (SPEARS) to assess supplier performance throughout the development and production stages of the SSCL program. The main objectives of SPEARS are to promote teamwork and recognize performance. This paper examines the current implementation of SPEARS. MSD QA supports the development and production of SSCsuperconducting magnets while implementing the requirements of DOE Order 5700.6C. The MSD QA program is based on the concept of continuous improvement in quality and productivity. The QA program requires that procurement of items and services be controlled to assure conformance to specification. SPEARS has been implemented to meet DOE requirements and to enhance overall confidence in supplier performance. Key elements of SPEARS include supplier evaluation and selection as well as evaluation of furnished quality through source inspection, audit, and receipt inspection. These elements are described in this paper.

  14. Effects of Performers' External Characteristics on Performance Evaluations.

    ERIC Educational Resources Information Center

    Bermingham, Gudrun A.

    2000-01-01

    States that fairness has been a major concern in the field of music adjudication. Reviews the research literature to reveal information about three external characteristics (race, gender, and physical attractiveness) that may affect judges' performance evaluations and influence fairness of music adjudication. Includes references. (CMK)

  15. Impact of Full-Day Head Start Prekindergarten Class Model on Student Academic Performance, Cognitive Skills, and Learning Behaviors by the End of Grade 2. Evaluation Brief

    ERIC Educational Resources Information Center

    Zhao, Huafang; Modarresi, Shahpar

    2013-01-01

    This brief describes the impact of the Montgomery County (Maryland) Public Schools (MCPS) 2007-2008 full-day Head Start prekindergarten (pre-K) class model on student academic performance, cognitive skills, and learning behaviors by the end of Grade 2. This is the fourth impact study of the MCPS full-day Head Start pre-K class model. The following…

  16. Performance evaluation of Space Shuttle SRB parachutes from air drop and scaled model wind tunnel tests. [Solid Rocket Booster recovery system

    NASA Technical Reports Server (NTRS)

    Moog, R. D.; Bacchus, D. L.; Utreja, L. R.

    1979-01-01

    The aerodynamic performance characteristics have been determined for the Space Shuttle Solid Rocket Booster drogue, main, and pilot parachutes. The performance evaluation on the 20-degree conical ribbon parachutes is based primarily on air drop tests of full scale prototype parachutes. In addition, parametric wind tunnel tests were performed and used in parachute configuration development and preliminary performance assessments. The wind tunnel test data are compared to the drop test results and both sets of data are used to determine the predicted performance of the Solid Rocket Booster flight parachutes. Data from other drop tests of large ribbon parachutes are also compared with the Solid Rocket Booster parachute performance characteristics. Parameters assessed include full open terminal drag coefficients, reefed drag area, opening characteristics, clustering effects, and forebody interference.

  17. Models for Automated Tube Performance Calculations

    SciTech Connect

    C. Brunkhorst

    2002-12-12

    High power radio-frequency systems, as typically used in fusion research devices, utilize vacuum tubes. Evaluation of vacuum tube performance involves data taken from tube operating curves. The acquisition of data from such graphical sources is a tedious process. A simple modeling method is presented that will provide values of tube currents for a given set of element voltages. These models may be used as subroutines in iterative solutions of amplifier operating conditions for a specific loading impedance.

  18. Using a landslide inventory from online news to evaluate the performance of warning models for rainfall-induced landslides in Italy

    NASA Astrophysics Data System (ADS)

    Pecoraro, Gaetano; Calvello, Michele

    2017-04-01

    In Italy rainfall-induced landslides pose a significant and widespread hazard, resulting in a large number of casualties and enormous economic damages. Mitigation of such a diffuse risk cannot be attained with structural measures only. With respect to the risk to life, early warning systems represent a viable and useful tool for landslide risk mitigation over wide areas. Inventories of rainfall-induced landslides are critical to support investigations of where and when landslides have happened and may occur in the future, i.e. to establish reliable correlations between rainfall characteristics and landslide occurrences. In this work a parametric study has been conducted to evaluate the performance of correlation models between rainfall and landslides over the Italian territory using the "FraneItalia" database, an inventory of landslides retrieved from online Italian journalistic news. The information reported for each record of this database always include: the site of occurrence of the landslides, the date of occurrence, the source of the news. Multiple landslides occurring in the same date, within the same province or region, are inventoried together in one single record of the database, in this case also reporting the number of landslides of the event. Each record the database may also include, if the related information is available: hour of occurrence; typology, volume and material of the landslide; activity phase; effects on people, structures, infrastructures, cars or other elements. The database currently contains six complete years of data (2010-2015), including more than 4000 landslide reports, most of them triggered by rainfall. For the aim of this study, different rainfall-landslides correlation models have been tested by analysing the reported landslides, within all the 144 zones identified by the national civil protection for weather-related warnings in Italy, in relation to satellite-based precipitations estimates from the Global Precipitation

  19. Large Signal Evaluation of Nonlinear HBT Model

    NASA Astrophysics Data System (ADS)

    Angelov, Iltcho; Inoue, Akira; Watanabe, Shinsuke

    The performance of recently developed Large Signal (LS) HBT model was evaluated with extensive LS measurements like Power spectrum, Load pull and Inter-modulation investigations. Proposed model has adopted temperature dependent leakage resistance and a simplified capacitance models. The model was implemented in ADS as SDD. Important feature of the model is that the main model parameters are taken directly from measurements in rather simple and understandable way. Results show good accuracy despite the simplicity of the model. To our knowledge the HBT model is one of a few HBT models which can handle high current & Power HBT devices, with significantly less model parameters with good accuracy.

  20. Evaluation of the performance of a meso-scale NWP model to forecast solar irradiance on Reunion Island for photovoltaic power applications

    NASA Astrophysics Data System (ADS)

    Kalecinski, Natacha; Haeffelin, Martial; Badosa, Jordi; Periard, Christophe

    2013-04-01

    Solar photovoltaic power is a predominant source of electrical power on Reunion Island, regularly providing near 30% of electrical power demand for a few hours per day. However solar power on Reunion Island is strongly modulated by clouds in small temporal and spatial scales. Today regional regulations require that new solar photovoltaic plants be combined with storage systems to reduce electrical power fluctuations on the grid. Hence cloud and solar irradiance forecasting becomes an important tool to help optimize the operation of new solar photovoltaic plants on Reunion Island. Reunion Island, located in the South West of the Indian Ocean, is exposed to persistent trade winds, most of all in winter. In summer, the southward motion of the ITCZ brings atmospheric instabilities on the island and weakens trade winds. This context together with the complex topography of Reunion Island, which is about 60 km wide, with two high summits (3070 and 2512 m) connected by a 1500 m plateau, makes cloudiness very heterogeneous. High cloudiness variability is found between mountain and coastal areas and between the windward, leeward and lateral regions defined with respect to the synoptic wind direction. A detailed study of local dynamics variability is necessary to better understand cloud life cycles around the island. In the presented work, our approach to explore the short-term solar irradiance forecast at local scales is to use the deterministic output from a meso-scale numerical weather prediction (NWP) model, AROME, developed by Meteo France. To start we evaluate the performance of the deterministic forecast from AROME by using meteorological measurements from 21 meteorological ground stations widely spread around the island (and with altitudes from 8 to 2245 m). Ground measurements include solar irradiation, wind speed and direction, relative humidity, air temperature, precipitation and pressure. Secondly we study in the model the local dynamics and thermodynamics that

  1. Evaluating student performance in clinical dietetics.

    PubMed

    Novascone, M A

    1985-06-01

    The focus of this study was on the development and field-testing of a set of behaviorally anchored rating scales for evaluating the clinical performance of dietetic students. The scales emphasized the application of skills and knowledge. A variation of the Smith-Kendall technique was used to develop the scales. The 42 participants involved in instrument development included dietetic students, didactic and clinical instructors, and dietetic practitioners. The completed instrument contained 8 dimension statements and 70 behavioral anchors. The instrument was field-tested in 16 clinical rotations within 8 dietetic education programs. Evaluators not only rated student performance but also critiqued the format and content of the scales. The mid-to-upper portions of each scale were used most frequently, and little score variation within or across programs was noted. The scales were deemed appropriate for formative evaluation; however, some evaluators who had to grade students' performance expressed a desire for performance standards defined in terms of grades. Because the process used to develop the instrument facilitated the articulation of performance criteria, it is recommended as a practical approach to setting performance standards.

  2. Evaluate reformer performance at a glance

    SciTech Connect

    Nag, A.

    1996-02-01

    Catalytic reforming is becoming increasingly important in replacing octane lost as the removal of lead from worldwide gasoline pools continues. A method has been developed that can quickly evaluate the performance of any catalytic reformer. The catalytic naphtha reforming process primarily involves three well-known reactions. These are aromatization of naphthenes, cyclization of paraffins and hydrocracking of paraffins. Hydrogen is produced in the process of aromatization and dehydrocyclization of paraffins. Reformer performance is normally evaluated with a reformate analysis (PONA) and yield of C{sub 5{sup +}} reformate. This method of quick evaluation of reformer performance is based upon the main assumption that the increase in hydrocarbon moles in the process is equal to the number of C{single_bond}C bond ruptures and one mole of hydrogen is absorbed to saturate the same. This new method calculates aromatization efficiency, paraffin conversion, aromatic selectivity and finally the paraffin, naphthene and aromatic content of C{sub 5{sup +}} reformate.

  3. Smith Newton Vehicle Performance Evaluation (Brochure)

    SciTech Connect

    Not Available

    2012-08-01

    The Fleet Test and Evaluation Team at the U.S. Department of Energy's National Renewable Energy Laboratory is evaluating and documenting the performance of electric and plug-in hybrid electric drive systems in medium-duty trucks across the nation. Through this project, Smith Electric Vehicles will build and deploy 500 all-electric medium-duty trucks. The trucks will be deployed in diverse climates across the country.

  4. Performance Evaluation and Benchmarking of Intelligent Systems

    SciTech Connect

    Madhavan, Raj; Messina, Elena; Tunstel, Edward

    2009-09-01

    To design and develop capable, dependable, and affordable intelligent systems, their performance must be measurable. Scientific methodologies for standardization and benchmarking are crucial for quantitatively evaluating the performance of emerging robotic and intelligent systems technologies. There is currently no accepted standard for quantitatively measuring the performance of these systems against user-defined requirements; and furthermore, there is no consensus on what objective evaluation procedures need to be followed to understand the performance of these systems. The lack of reproducible and repeatable test methods has precluded researchers working towards a common goal from exchanging and communicating results, inter-comparing system performance, and leveraging previous work that could otherwise avoid duplication and expedite technology transfer. Currently, this lack of cohesion in the community hinders progress in many domains, such as manufacturing, service, healthcare, and security. By providing the research community with access to standardized tools, reference data sets, and open source libraries of solutions, researchers and consumers will be able to evaluate the cost and benefits associated with intelligent systems and associated technologies. In this vein, the edited book volume addresses performance evaluation and metrics for intelligent systems, in general, while emphasizing the need and solutions for standardized methods. To the knowledge of the editors, there is not a single book on the market that is solely dedicated to the subject of performance evaluation and benchmarking of intelligent systems. Even books that address this topic do so only marginally or are out of date. The research work presented in this volume fills this void by drawing from the experiences and insights of experts gained both through theoretical development and practical implementation of intelligent systems in a variety of diverse application domains. The book presents

  5. Using multifractals to evaluate oceanographic model skill

    NASA Astrophysics Data System (ADS)

    Skákala, Jozef; Cazenave, Pierre W.; Smyth, Timothy J.; Torres, Ricardo

    2016-08-01

    We are in an era of unprecedented data volumes generated from observations and model simulations. This is particularly true from satellite Earth Observations (EO) and global scale oceanographic models. This presents us with an opportunity to evaluate large-scale oceanographic model outputs using EO data. Previous work on model skill evaluation has led to a plethora of metrics. The paper defines two new model skill evaluation metrics. The metrics are based on the theory of universal multifractals and their purpose is to measure the structural similarity between the model predictions and the EO data. The two metrics have the following advantages over the standard techniques: (a) they are scale-free and (b) they carry important part of information about how model represents different oceanographic drivers. Those two metrics are then used in the paper to evaluate the performance of the FVCOM model in the shelf seas around the south-west coast of the UK.

  6. DRACS thermal performance evaluation for FHR

    SciTech Connect

    Lv, Q.; Lin, H. C.; Kim, I. H.; Sun, X.; Christensen, R. N.; Blue, T. E.; Yoder, G. L.; Wilson, D. F.; Sabharwall, P.

    2015-03-01

    Direct Reactor Auxiliary Cooling System (DRACS) is a passive decay heat removal system proposed for the Fluoride-salt-cooled High-temperature Reactor (FHR) that combines coated particle fuel and a graphite moderator with a liquid fluoride salt as the coolant. The DRACS features three coupled natural circulation/convection loops, relying completely on buoyancy as the driving force. These loops are coupled through two heat exchangers, namely, the DRACS Heat Exchanger and the Natural Draft Heat Exchanger. In addition, a fluidic diode is employed to minimize the parasitic flow into the DRACS primary loop and correspondingly the heat loss to the DRACS during normal operation of the reactor, and to keep the DRACS ready for activation, if needed, during accidents. To help with the design and thermal performance evaluation of the DRACS, a computer code using MATLAB has been developed. This code is based on a one-dimensional formulation and its principle is to solve the energy balance and integral momentum equations. By discretizing the DRACS system in the axial direction, a bulk mean temperature is assumed for each mesh cell. The temperatures of all the cells, as well as the mass flow rates in the DRACS loops, are predicted by solving the governing equations that are obtained by integrating the energy conservation equation over each cell and integrating the momentum conservation equation over each of the DRACS loops. In addition, an intermediate heat transfer loop equipped with a pump has also been modeled in the code. This enables the study of flow reversal phenomenon in the DRACS primary loop, associated with the pump trip process. Experimental data from a High-Temperature DRACS Test Facility (HTDF) are not available yet to benchmark the code. A preliminary code validation is performed by using natural circulation experimental data available in the literature, which are as closely relevant as possible. The code is subsequently applied to the HTDF that is under

  7. Smith Newton Vehicle Performance Evaluation - Cumulative (Brochure)

    SciTech Connect

    Not Available

    2014-08-01

    The Fleet Test and Evaluation Team at the U.S. Department of Energy's National Renewable Energy Laboratory is evaluating and documenting the performance of electric and plug-in hybrid electric drive systems in medium-duty trucks across the nation. U.S. companies participating in this evaluation project received funding from the American Recovery and Reinvestment Act to cover part of the cost of purchasing these vehicles. Through this project, Smith Electric Vehicles is building and deploying 500 all-electric medium-duty trucks that will be deployed by a variety of companies in diverse climates across the country.

  8. Performance evaluations of demountable electrical connections

    NASA Astrophysics Data System (ADS)

    Niemann, R. C.; Cha, Y. S.; Hull, J. R.; Buckles, W. E.; Daugherty, M. A.

    Electrical conductors operating in cryogenic environments can require demountable connections along their lengths. The connections must have low resistance and high reliability and should allow ready assembly and disassembly. In this work, the performance of two types of connections has been evaluated. The first connection type is a clamped surface-to-surface joint. The second connection type is a screwed joint that incorporates male and female machine-thread components. The connections for copper conductors have been evaluated experimentally at 77 K. Experimental variables included thread surface treatment and assembly methods. The results of the evaluations are presented.

  9. Evaluation of Outbreak Detection Performance Using Multi-Stream Syndromic Surveillance for Influenza-Like Illness in Rural Hubei Province, China: A Temporal Simulation Model Based on Healthcare-Seeking Behaviors

    PubMed Central

    Fan, Yunzhou; Wang, Ying; Jiang, Hongbo; Yang, Wenwen; Yu, Miao; Yan, Weirong; Diwan, Vinod K.; Xu, Biao; Dong, Hengjin; Palm, Lars; Nie, Shaofa

    2014-01-01

    Background Syndromic surveillance promotes the early detection of diseases outbreaks. Although syndromic surveillance has increased in developing countries, performance on outbreak detection, particularly in cases of multi-stream surveillance, has scarcely been evaluated in rural areas. Objective This study introduces a temporal simulation model based on healthcare-seeking behaviors to evaluate the performance of multi-stream syndromic surveillance for influenza-like illness. Methods Data were obtained in six towns of rural Hubei Province, China, from April 2012 to June 2013. A Susceptible-Exposed-Infectious-Recovered model generated 27 scenarios of simulated influenza A (H1N1) outbreaks, which were converted into corresponding simulated syndromic datasets through the healthcare-behaviors model. We then superimposed converted syndromic datasets onto the baselines obtained to create the testing datasets. Outbreak performance of single-stream surveillance of clinic visit, frequency of over the counter drug purchases, school absenteeism, and multi-stream surveillance of their combinations were evaluated using receiver operating characteristic curves and activity monitoring operation curves. Results In the six towns examined, clinic visit surveillance and school absenteeism surveillance exhibited superior performances of outbreak detection than over the counter drug purchase frequency surveillance; the performance of multi-stream surveillance was preferable to signal-stream surveillance, particularly at low specificity (Sp <90%). Conclusions The temporal simulation model based on healthcare-seeking behaviors offers an accessible method for evaluating the performance of multi-stream surveillance. PMID:25409025

  10. Performance Evaluation of NoSQL Databases: A Case Study

    DTIC Science & Technology

    2015-02-01

    Performance Evaluation of NoSQL Databases : A Case Study John Klein, Ian Gorton, Neil Ernst, Patrick Donohoe Software Engineering Institute...The choice of a particular NoSQL database imposes a specific distributed software architecture and data model, and is a major determinant of the...overall system throughput. NoSQL database performance is in turn strongly influenced by how well the data model and query capabilities fit the

  11. Visual Performance Prediction Using Schematic Eye Models

    NASA Astrophysics Data System (ADS)

    Schwiegerling, James Theodore

    The goal of visual modeling is to predict the visual performance or a change in performance of an individual from a model of the human visual system. In designing a model of the human visual system, two distinct functions are considered. The first is the production of an image incident on the retina by the optical system of the eye, and the second is the conversion of this image into a perceived image by the retina and brain. The eye optics are evaluated using raytracing techniques familiar to the optical engineer. The effect of the retinal and brain function are combined with the raytracing results by analyzing the modulation of the retinal image. Each of these processes is important far evaluating the performance of the entire visual system. Techniques for converting the abstract system performance measures used by optical engineers into clinically -applicable measures such as visual acuity and contrast sensitivity are developed in this dissertation. Furthermore, a methodology for applying videokeratoscopic height data to the visual model is outlined. These tools are useful in modeling the visual effects of corrective lenses, ocular maladies and refractive surgeries. The modeling techniques are applied to examples of soft contact lenses, keratoconus, radial keratotomy, photorefractive keratectomy and automated lamellar keratoplasty. The modeling tools developed in this dissertation are meant to be general and modular. As improvements to the measurements of the properties and functionality of the various visual components are made, the new information can be incorporated into the visual system model. Furthermore, the examples discussed here represent only a small subset of the applications of the visual model. Additional ocular maladies and emerging refractive surgeries can be modeled as well.

  12. Evaluating the performance of a new model for predicting the growth of Clostridium perfringens in cooked, uncured meat and poultry products under isothermal, heating, and dynamically cooling conditions

    USDA-ARS?s Scientific Manuscript database

    Clostridium perfringens Type A is a significant public health threat and may germinate, outgrow, and multiply during cooling of cooked meats. This study evaluates a new C. perfringens growth model in IPMP Dynamic Prediction using the same criteria and cooling data in Mohr and others (2015), but inc...

  13. Data management system performance modeling

    NASA Technical Reports Server (NTRS)

    Kiser, Larry M.

    1993-01-01

    This paper discusses analytical techniques that have been used to gain a better understanding of the Space Station Freedom's (SSF's) Data Management System (DMS). The DMS is a complex, distributed, real-time computer system that has been redesigned numerous times. The implications of these redesigns have not been fully analyzed. This paper discusses the advantages and disadvantages for static analytical techniques such as Rate Monotonic Analysis (RMA) and also provides a rationale for dynamic modeling. Factors such as system architecture, processor utilization, bus architecture, queuing, etc. are well suited for analysis with a dynamic model. The significance of performance measures for a real-time system are discussed.

  14. Data management system performance modeling

    NASA Technical Reports Server (NTRS)

    Kiser, Larry M.

    1993-01-01

    This paper discusses analytical techniques that have been used to gain a better understanding of the Space Station Freedom's (SSF's) Data Management System (DMS). The DMS is a complex, distributed, real-time computer system that has been redesigned numerous times. The implications of these redesigns have not been fully analyzed. This paper discusses the advantages and disadvantages for static analytical techniques such as Rate Monotonic Analysis (RMA) and also provides a rationale for dynamic modeling. Factors such as system architecture, processor utilization, bus architecture, queuing, etc. are well suited for analysis with a dynamic model. The significance of performance measures for a real-time system are discussed.

  15. 48 CFR 436.604 - Performance evaluation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Architect-Engineer Service 436.604... require a performance evaluation report on the work done by the architect-engineer after the completion of or during the construction of the designed project....

  16. Simplified method for video performance evaluation

    NASA Astrophysics Data System (ADS)

    Harshbarger, John H.

    1996-04-01

    Meaningful performance evaluation of video equipment can be complex, requiring specialized equipment in which results must be interpreted by technically trained operators. The alternative to this has been to attempt evaluation by visual inspection of patterns such as the SMPTE RP-133 Medical Imaging Standard. However this involves subjective interpretation and does not indicate the point in a system at which degradation has occurred. The video waveform of such a pattern is complex and not suitable for quantitative analysis. The principal factors which influence quality of a video image on a day-to-day basis are resolution, gray scale and color, if employed. If these qualities are transmitted and displayed without degradation beyond acceptable limits, suitable performance is assured. Performance evaluation by inspection of the image produced on a video display monitor is subject to interpretation; this is resolved by inserting, at the display, the original 'perfect' electronically generated waveform to serve as a reference. Thus the viewer has a specific visual comparison as the basis for performance evaluation. Another valuable feature of the test pattern insert is that a test segment can be placed on recorded images. Thus each image recalled by tape playback or from digital storage will carry an integral means for quality assurance.

  17. GENERAL METHODS FOR REMEDIAL PERFORMANCE EVALUATIONS

    EPA Science Inventory

    This document was developed by an EPA-funded project to explain technical considerations and principles necessary to evaluated the performance of ground-water contamination remediations at hazardous waste sites. This is neither a "cookbook", nor an encyclopedia of recommended fi...

  18. Performance Evaluation of a Semantic Perception Classifier

    DTIC Science & Technology

    2013-09-01

    Performance Evaluation of a Semantic Perception Classifier by Craig Lennon, Barry Bodt, Marshal Childers, Rick Camden, Arne Suppe, Luis...Camden and Nicoleta Florea Engility Corporation Luis Navarro-Serment and Arne Suppe Carnegie Mellon University...Lennon, Barry Bodt, Marshal Childers, Rick Camden,* Arne Suppe, † Luis Navarro-Serment, † and Nicoleta Florea* 5d. PROJECT NUMBER 5e. TASK

  19. Performance evaluation of an air solar collector

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Indoor tests on signal-glazed flat-plate collector are described in report. Marhsall Space Flight Center solar simulator is used to make tests. Test included evaluations on thermal performance under various combinations of flow rate, incident flux, inlet temperature, and wind speed. Results are presented in graph/table form.

  20. ASBESTOS IN DRINKING WATER PERFORMANCE EVALUATION STUDIES

    EPA Science Inventory

    Performance evaluations of laboratories testing for asbestos in drinking water according to USEPA Test Method 100.1 or 100.2 are complicated by the difficulty of providing stable sample dispersions of asbestos in water. Reference samples of a graduated series of chrysotile asbes...

  1. ASBESTOS IN DRINKING WATER PERFORMANCE EVALUATION STUDIES

    EPA Science Inventory

    Performance evaluations of laboratories testing for asbestos in drinking water according to USEPA Test Method 100.1 or 100.2 are complicated by the difficulty of providing stable sample dispersions of asbestos in water. Reference samples of a graduated series of chrysotile asbest...

  2. EVALUATION OF CONFOCAL MICROSCOPY SYSTEM PERFORMANCE

    EPA Science Inventory

    BACKGROUND. The confocal laser scanning microscope (CLSM) has enormous potential in many biological fields. Currently there is a subjective nature in the assessment of a confocal microscope's performance by primarily evaluating the system with a specific test slide provided by ea...

  3. The Performance Evaluation of Corporate Universities

    ERIC Educational Resources Information Center

    Cappiello, Giuseppe; Pedrini, Giulio

    2017-01-01

    The aim of this paper is to illustrate the phenomenon of corporate universities from the perspective of the evaluation of their performance. Corporate universities have a hybrid nature that can be referred to both as a business unit and as a higher education institution. Having reviewed the literature on corporate universities and performance…

  4. Performance Evaluation for Non-Teaching Professionals.

    ERIC Educational Resources Information Center

    Panebianco, Anthony F.

    The program Performance Evaluation for Non-Teaching Professionals at the State University of New York Institute of Technology at Utica/Rome provides periodic assessments as required by institutional policy. The system is intended to establish a standard for judging quality of an employee's work and a rational and uniform basis for appraising…

  5. Performance evaluation of lightweight piezocomposite curved actuator

    NASA Astrophysics Data System (ADS)

    Goo, Nam Seo; Kim, Cheol; Park, Hoon C.; Yoon, Kwang J.

    2001-07-01

    A numerical method for the performance evaluation of LIPCA actuators is proposed using a finite element method. Fully-coupled formulations for piezo-electric materials are introduced and eight-node incompatible elements used. After verifying the developed code, the behavior of LIPCA actuators is investigated.

  6. GENERAL METHODS FOR REMEDIAL PERFORMANCE EVALUATIONS

    EPA Science Inventory

    This document was developed by an EPA-funded project to explain technical considerations and principles necessary to evaluated the performance of ground-water contamination remediations at hazardous waste sites. This is neither a "cookbook", nor an encyclopedia of recommended fi...

  7. Measures of Searcher Performance: A Psychometric Evaluation.

    ERIC Educational Resources Information Center

    Wildemuth, Barbara M.; And Others

    1993-01-01

    Describes a study of medical students that was conducted to evaluate measures of performance on factual searches of INQUIRER, a full-text database in microbiology. Measures relating to recall, precision, search term overlap, and efficiency are discussed; reliability and construct validity are considered; and implications for future research are…

  8. 48 CFR 36.604 - Performance evaluation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Performance evaluation. 36.604 Section 36.604 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Architect-Engineer Services 36.604...

  9. 48 CFR 36.604 - Performance evaluation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Performance evaluation. 36.604 Section 36.604 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Architect-Engineer Services 36.604...

  10. 48 CFR 236.604 - Performance evaluation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Performance evaluation. 236.604 Section 236.604 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS...

  11. 48 CFR 436.604 - Performance evaluation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 4 2014-10-01 2014-10-01 false Performance evaluation. 436.604 Section 436.604 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Architect-Engineer Service 436.604...

  12. 48 CFR 236.604 - Performance evaluation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Performance evaluation. 236.604 Section 236.604 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS...

  13. 48 CFR 436.604 - Performance evaluation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 4 2013-10-01 2013-10-01 false Performance evaluation. 436.604 Section 436.604 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Architect-Engineer Service 436.604...

  14. 48 CFR 2936.604 - Performance evaluation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Performance evaluation. 2936.604 Section 2936.604 Federal Acquisition Regulations System DEPARTMENT OF LABOR GENERAL CONTRACTING REQUIREMENTS CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Architect-Engineer Services 2936.604...

  15. 48 CFR 236.604 - Performance evaluation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Performance evaluation. 236.604 Section 236.604 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS...

  16. 48 CFR 236.604 - Performance evaluation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Performance evaluation. 236.604 Section 236.604 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS...

  17. 48 CFR 36.604 - Performance evaluation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Performance evaluation. 36.604 Section 36.604 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Architect-Engineer Services 36.604...

  18. 48 CFR 436.604 - Performance evaluation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Performance evaluation. 436.604 Section 436.604 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Architect-Engineer Service 436.604...