WorldWideScience

Sample records for modeling performance assessment

  1. Behavior model for performance assessment.

    Energy Technology Data Exchange (ETDEWEB)

    Borwn-VanHoozer, S. A.

    1999-07-23

    Every individual channels information differently based on their preference of the sensory modality or representational system (visual auditory or kinesthetic) we tend to favor most (our primary representational system (PRS)). Therefore, some of us access and store our information primarily visually first, some auditorily, and others kinesthetically (through feel and touch); which in turn establishes our information processing patterns and strategies and external to internal (and subsequently vice versa) experiential language representation. Because of the different ways we channel our information, each of us will respond differently to a task--the way we gather and process the external information (input), our response time (process), and the outcome (behavior). Traditional human models of decision making and response time focus on perception, cognitive and motor systems stimulated and influenced by the three sensory modalities, visual, auditory and kinesthetic. For us, these are the building blocks to knowing how someone is thinking. Being aware of what is taking place and how to ask questions is essential in assessing performance toward reducing human errors. Existing models give predications based on time values or response times for a particular event, and may be summed and averaged for a generalization of behavior(s). However, by our not establishing a basic understanding of the foundation of how the behavior was predicated through a decision making strategy process, predicative models are overall inefficient in their analysis of the means by which behavior was generated. What is seen is the end result.

  2. Behavior model for performance assessment

    International Nuclear Information System (INIS)

    Brown-VanHoozer, S. A.

    1999-01-01

    Every individual channels information differently based on their preference of the sensory modality or representational system (visual auditory or kinesthetic) we tend to favor most (our primary representational system (PRS)). Therefore, some of us access and store our information primarily visually first, some auditorily, and others kinesthetically (through feel and touch); which in turn establishes our information processing patterns and strategies and external to internal (and subsequently vice versa) experiential language representation. Because of the different ways we channel our information, each of us will respond differently to a task--the way we gather and process the external information (input), our response time (process), and the outcome (behavior). Traditional human models of decision making and response time focus on perception, cognitive and motor systems stimulated and influenced by the three sensory modalities, visual, auditory and kinesthetic. For us, these are the building blocks to knowing how someone is thinking. Being aware of what is taking place and how to ask questions is essential in assessing performance toward reducing human errors. Existing models give predications based on time values or response times for a particular event, and may be summed and averaged for a generalization of behavior(s). However, by our not establishing a basic understanding of the foundation of how the behavior was predicated through a decision making strategy process, predicative models are overall inefficient in their analysis of the means by which behavior was generated. What is seen is the end result

  3. Evaluation of models in performance assessment

    International Nuclear Information System (INIS)

    Dormuth, K.W.

    1993-01-01

    The reliability of models used for performance assessment for high-level waste repositories is a key factor in making decisions regarding the management of high-level waste. Model reliability may be viewed as a measure of the confidence that regulators and others have in the use of these models to provide information for decision making. The degree of reliability required for the models will increase as implementation of disposal proceeds and decisions become increasingly important to safety. Evaluation of the models by using observations of real systems provides information that assists the assessment analysts and reviewers in establishing confidence in the conclusions reached in the assessment. A continuing process of model calibration, evaluation, and refinement should lead to increasing reliability of models as implementation proceeds. However, uncertainty in the model predictions cannot be eliminated, so decisions will always be made under some uncertainty. Examples from the Canadian program illustrate the process of model evaluation using observations of real systems and its relationship to performance assessment. 21 refs., 2 figs

  4. Tailored model abstraction in performance assessments

    International Nuclear Information System (INIS)

    Kessler, J.H.

    1995-01-01

    Total System Performance Assessments (TSPAs) are likely to be one of the most significant parts of making safety cases for the continued development and licensing of geologic repositories for the disposal of spent fuel and HLW. Thus, it is critical that the TSPA model capture the 'essence' of the physical processes relevant to demonstrating the appropriate regulation is met. But how much detail about the physical processes must be modeled and understood before there is enough confidence that the appropriate essence has been captured? In this summary the level of model abstraction that is required is discussed. Approaches for subsystem and total system performance analyses are outlined, and the role of best estimate models is examined. It is concluded that a conservative approach for repository performance, based on limited amount of field and laboratory data, can provide sufficient confidence for a regulatory decision

  5. Assessing Ecosystem Model Performance in Semiarid Systems

    Science.gov (United States)

    Thomas, A.; Dietze, M.; Scott, R. L.; Biederman, J. A.

    2017-12-01

    In ecosystem process modelling, comparing outputs to benchmark datasets observed in the field is an important way to validate models, allowing the modelling community to track model performance over time and compare models at specific sites. Multi-model comparison projects as well as models themselves have largely been focused on temperate forests and similar biomes. Semiarid regions, on the other hand, are underrepresented in land surface and ecosystem modelling efforts, and yet will be disproportionately impacted by disturbances such as climate change due to their sensitivity to changes in the water balance. Benchmarking models at semiarid sites is an important step in assessing and improving models' suitability for predicting the impact of disturbance on semiarid ecosystems. In this study, several ecosystem models were compared at a semiarid grassland in southwestern Arizona using PEcAn, or the Predictive Ecosystem Analyzer, an open-source eco-informatics toolbox ideal for creating the repeatable model workflows necessary for benchmarking. Models included SIPNET, DALEC, JULES, ED2, GDAY, LPJ-GUESS, MAESPA, CLM, CABLE, and FATES. Comparison between model output and benchmarks such as net ecosystem exchange (NEE) tended to produce high root mean square error and low correlation coefficients, reflecting poor simulation of seasonality and the tendency for models to create much higher carbon sources than observed. These results indicate that ecosystem models do not currently adequately represent semiarid ecosystem processes.

  6. Performance assessment modeling of pyrometallurgical process wasteforms

    International Nuclear Information System (INIS)

    Nutt, W.M.; Hill, R.N.; Bullen, D.B.

    1995-01-01

    Performance assessment analyses have been completed to estimate the behavior of high-level nuclear wasteforms generated from the pyrometallurgical processing of liquid metal reactor (LMR) and light water reactor (LWR) spent nuclear fuel. Waste emplaced in the proposed repository at Yucca Mountain is investigated as the basis for the study. The resulting cumulative actinide and fission product releases to the accessible environment within a 100,000 year period from the various pyrometallurgical process wasteforms are compared to those of directly disposed LWR spent fuel using the same total repository system model. The impact of differing radionuclide transport models on the overall release characteristics is investigated

  7. Probabilistic Radiological Performance Assessment Modeling and Uncertainty

    Science.gov (United States)

    Tauxe, J.

    2004-12-01

    A generic probabilistic radiological Performance Assessment (PA) model is presented. The model, built using the GoldSim systems simulation software platform, concerns contaminant transport and dose estimation in support of decision making with uncertainty. Both the U.S. Nuclear Regulatory Commission (NRC) and the U.S. Department of Energy (DOE) require assessments of potential future risk to human receptors of disposal of LLW. Commercially operated LLW disposal facilities are licensed by the NRC (or agreement states), and the DOE operates such facilities for disposal of DOE-generated LLW. The type of PA model presented is probabilistic in nature, and hence reflects the current state of knowledge about the site by using probability distributions to capture what is expected (central tendency or average) and the uncertainty (e.g., standard deviation) associated with input parameters, and propagating through the model to arrive at output distributions that reflect expected performance and the overall uncertainty in the system. Estimates of contaminant release rates, concentrations in environmental media, and resulting doses to human receptors well into the future are made by running the model in Monte Carlo fashion, with each realization representing a possible combination of input parameter values. Statistical summaries of the results can be compared to regulatory performance objectives, and decision makers are better informed of the inherently uncertain aspects of the model which supports their decision-making. While this information may make some regulators uncomfortable, they must realize that uncertainties which were hidden in a deterministic analysis are revealed in a probabilistic analysis, and the chance of making a correct decision is now known rather than hoped for. The model includes many typical features and processes that would be part of a PA, but is entirely fictitious. This does not represent any particular site and is meant to be a generic example. A

  8. Assessing The Performance of Hydrological Models

    Science.gov (United States)

    van der Knijff, Johan

    The performance of hydrological models is often characterized using the coefficient of efficiency, E. The sensitivity of E to extreme streamflow values, and the difficulty of deciding what value of E should be used as a threshold to identify 'good' models or model parameterizations, have proven to be serious shortcomings of this index. This paper reviews some alternative performance indices that have appeared in the litera- ture. Legates and McCabe (1999) suggested a more generalized form of E, E'(j,B). Here, j is a parameter that controls how much emphasis is put on extreme streamflow values, and B defines a benchmark or 'null hypothesis' against which the results of the model are tested. E'(j,B) was used to evaluate a large number of parameterizations of a conceptual rainfall-runoff model, using 6 different combinations of j and B. First, the effect of j and B is explained. Second, it is demonstrated how the index can be used to explicitly test hypotheses about the model and the data. This approach appears to be particularly attractive if the index is used as a likelihood measure within a GLUE-type analysis.

  9. New Diagnostics to Assess Model Performance

    Science.gov (United States)

    Koh, Tieh-Yong

    2013-04-01

    The comparison of model performance between the tropics and the mid-latitudes is particularly problematic for observables like temperature and humidity: in the tropics, these observables have little variation and so may give an apparent impression that model predictions are often close to observations; on the contrary, they vary widely in mid-latitudes and so the discrepancy between model predictions and observations might be unnecessarily over-emphasized. We have developed a suite of mathematically rigorous diagnostics that measures normalized errors accounting for the observed and modeled variability of the observables themselves. Another issue in evaluating model performance is the relative importance of getting the variance of an observable right versus getting the modeled variation to be in phase with the observed. The correlation-similarity diagram was designed to analyse the pattern error of a model by breaking it down into contributions from amplitude and phase errors. A final and important question pertains to the generalization of scalar diagnostics to analyse vector observables like wind. In particular, measures of variance and correlation must be properly derived to avoid the mistake of ignoring the covariance between north-south and east-west winds (hence wrongly assuming that the north-south and east-west directions form a privileged vector basis for error analysis). There is also a need to quantify systematic preferences in the direction of vector wind errors, which we make possible by means of an error anisotropy diagram. Although the suite of diagnostics is mentioned with reference to model verification here, it is generally applicable to quantify differences between two datasets (e.g. from two observation platforms). Reference publication: Koh, T. Y. et al. (2012), J. Geophys. Res., 117, D13109, doi:10.1029/2011JD017103. also available at http://www.ntu.edu.sg/home/kohty

  10. Persistence Modeling for Assessing Marketing Strategy Performance

    NARCIS (Netherlands)

    M.G. Dekimpe (Marnik); D.M. Hanssens (Dominique)

    2003-01-01

    textabstractThe question of long-run market response lies at the heart of any marketing strategy that tries to create a sustainable competitive advantage for the firm or brand. A key challenge, however, is that only short-run results of marketing actions are readily observable. Persistence modeling

  11. An Empirical Study of a Solo Performance Assessment Model

    Science.gov (United States)

    Russell, Brian E.

    2015-01-01

    The purpose of this study was to test a hypothesized model of solo music performance assessment. Specifically, this study investigates the influence of technique and musical expression on perceptions of overall performance quality. The Aural Musical Performance Quality (AMPQ) measure was created to measure overall performance quality, technique,…

  12. ASSESSING INDIVIDUAL PERFORMANCE ON INFORMATION TECHNOLOGY ADOPTION: A NEW MODEL

    OpenAIRE

    Diah Hari Suryaningrum

    2012-01-01

    This paper aims to propose a new model in assessing individual performance on information technology adoption. The new model to assess individual performance was derived from two different theories: decomposed theory of planned behavior and task-technology fit theory. Although many researchers have tried to expand these theories, some of their efforts might lack of theoretical assumptions. To overcome this problem and enhance the coherence of the integration, I used a theory from social scien...

  13. Conceptual adsorption models and open issues pertaining to performance assessment

    International Nuclear Information System (INIS)

    Serne, R.J.

    1992-01-01

    Recently several articles have been published that question the appropriateness of the distribution coefficient, Rd, concept to quantify radionuclide migration. Several distinct issues surrounding the modeling of nuclide retardation. The first section defines adsorption terminology and discusses various adsorption processes. The next section describes five commonly used adsorption conceptual models, specifically emphasizing what attributes that affect adsorption are explicitly accommodated in each model. I also review efforts to incorporate each adsorption model into performance assessment transport computer codes. The five adsorption conceptual models are (1) the constant Rd model, (2) the parametric Rd model, (3) isotherm adsorption models, (4) mass action adsorption models, and (5) surface-complexation with electrostatics models. The final section discusses the adequacy of the distribution ratio concept, the adequacy of transport calculations that rely on constant retardation factors and the status of incorporating sophisticated adsorption models into transport codes. 86 refs., 1 fig., 1 tab

  14. Some considerations for validation of repository performance assessment models

    International Nuclear Information System (INIS)

    Eisenberg, N.

    1991-01-01

    Validation is an important aspect of the regulatory uses of performance assessment. A substantial body of literature exists indicating the manner in which validation of models is usually pursued. Because performance models for a nuclear waste repository cannot be tested over the long time periods for which the model must make predictions, the usual avenue for model validation is precluded. Further impediments to model validation include a lack of fundamental scientific theory to describe important aspects of repository performance and an inability to easily deduce the complex, intricate structures characteristic of a natural system. A successful strategy for validation must attempt to resolve these difficulties in a direct fashion. Although some procedural aspects will be important, the main reliance of validation should be on scientific substance and logical rigor. The level of validation needed will be mandated, in part, by the uses to which these models are put, rather than by the ideal of validation of a scientific theory. Because of the importance of the validation of performance assessment models, the NRC staff has engaged in a program of research and international cooperation to seek progress in this important area. 2 figs., 16 refs

  15. Radionuclide release rates from spent fuel for performance assessment modeling

    International Nuclear Information System (INIS)

    Curtis, D.B.

    1994-01-01

    In a scenario of aqueous transport from a high-level radioactive waste repository, the concentration of radionuclides in water in contact with the waste constitutes the source term for transport models, and as such represents a fundamental component of all performance assessment models. Many laboratory experiments have been done to characterize release rates and understand processes influencing radionuclide release rates from irradiated nuclear fuel. Natural analogues of these waste forms have been studied to obtain information regarding the long-term stability of potential waste forms in complex natural systems. This information from diverse sources must be brought together to develop and defend methods used to define source terms for performance assessment models. In this manuscript examples of measures of radionuclide release rates from spent nuclear fuel or analogues of nuclear fuel are presented. Each example represents a very different approach to obtaining a numerical measure and each has its limitations. There is no way to obtain an unambiguous measure of this or any parameter used in performance assessment codes for evaluating the effects of processes operative over many millennia. The examples are intended to suggest by example that in the absence of the ability to evaluate accuracy and precision, consistency of a broadly based set of data can be used as circumstantial evidence to defend the choice of parameters used in performance assessments

  16. The Network Performance Assessment Model - Regulation with a Reference Network

    International Nuclear Information System (INIS)

    Larsson, Mats B.O.

    2003-11-01

    A new model - the Network Performance Assessment Model - has been developed gradually since 1998, in order to evaluate and benchmark local electricity grids. The model is intended to be a regulation tool for the Swedish local electricity networks, used by the Swedish Energy Agency. At spring 2004 the Network Performance Assessment Model will run into operation, based on the companies' results for 2003. The mission of the Network Performance Assessment Model is to evaluate the networks from a costumers' point of view and establish a fair price level. In order to do that, the performance of the operator is evaluated. The performances are assessed in correspondence to a price level that the consumer is considered to accept, can agree to as fair and is prepared to pay. This price level is based on an average cost, based on the cost of an efficient grid that will be built today, with already known technology. The performances are accounted in Customer Values. Those Customer Values are what can be created by someone but can't be created better by someone else. The starting point is to look upon the companies from a customers' point of view. The factors that can't be influenced by the companies are evaluated by fixed rules, valid to all companies. The rules reflect the differences. The cost for a connection is evaluated from the actual facts, i.e. the distances between the subscribers and the demanded capacity by the subscriber. This is done by the creation of a reference network, with a capacity to fulfill the demand from the subscriber. This is an efficient grid with no spare capacity and no excess capacity. The companies' existing grid are without importance, as well as holds for dimensioning as technology. Those factors which the company can influence, for an example connection reliability, are evaluated from a customer perspective by measuring the actual reliability, measured as the number and length of the interruption. When implemented to the regulation the Network

  17. PORFLOW Modeling Supporting The H-Tank Farm Performance Assessment

    International Nuclear Information System (INIS)

    Jordan, J. M.; Flach, G. P.; Westbrook, M. L.

    2012-01-01

    Numerical simulations of groundwater flow and contaminant transport in the vadose and saturated zones have been conducted using the PORFLOW code in support of an overall Performance Assessment (PA) of the H-Tank Farm. This report provides technical detail on selected aspects of PORFLOW model development and describes the structure of the associated electronic files. The PORFLOW models for the H-Tank Farm PA, Rev. 1 were updated with grout, solubility, and inventory changes. The aquifer model was refined. In addition, a set of flow sensitivity runs were performed to allow flow to be varied in the related probabilistic GoldSim models. The final PORFLOW concentration values are used as input into a GoldSim dose calculator

  18. PORFLOW Modeling Supporting The H-Tank Farm Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, J. M.; Flach, G. P.; Westbrook, M. L.

    2012-08-31

    Numerical simulations of groundwater flow and contaminant transport in the vadose and saturated zones have been conducted using the PORFLOW code in support of an overall Performance Assessment (PA) of the H-Tank Farm. This report provides technical detail on selected aspects of PORFLOW model development and describes the structure of the associated electronic files. The PORFLOW models for the H-Tank Farm PA, Rev. 1 were updated with grout, solubility, and inventory changes. The aquifer model was refined. In addition, a set of flow sensitivity runs were performed to allow flow to be varied in the related probabilistic GoldSim models. The final PORFLOW concentration values are used as input into a GoldSim dose calculator.

  19. Spatial variability and parametric uncertainty in performance assessment models

    International Nuclear Information System (INIS)

    Pensado, Osvaldo; Mancillas, James; Painter, Scott; Tomishima, Yasuo

    2011-01-01

    The problem of defining an appropriate treatment of distribution functions (which could represent spatial variability or parametric uncertainty) is examined based on a generic performance assessment model for a high-level waste repository. The generic model incorporated source term models available in GoldSim ® , the TDRW code for contaminant transport in sparse fracture networks with a complex fracture-matrix interaction process, and a biosphere dose model known as BDOSE TM . Using the GoldSim framework, several Monte Carlo sampling approaches and transport conceptualizations were evaluated to explore the effect of various treatments of spatial variability and parametric uncertainty on dose estimates. Results from a model employing a representative source and ensemble-averaged pathway properties were compared to results from a model allowing for stochastic variation of transport properties along streamline segments (i.e., explicit representation of spatial variability within a Monte Carlo realization). We concluded that the sampling approach and the definition of an ensemble representative do influence consequence estimates. In the examples analyzed in this paper, approaches considering limited variability of a transport resistance parameter along a streamline increased the frequency of fast pathways resulting in relatively high dose estimates, while those allowing for broad variability along streamlines increased the frequency of 'bottlenecks' reducing dose estimates. On this basis, simplified approaches with limited consideration of variability may suffice for intended uses of the performance assessment model, such as evaluation of site safety. (author)

  20. A Fuzzy Knowledge Representation Model for Student Performance Assessment

    DEFF Research Database (Denmark)

    Badie, Farshad

    Knowledge representation models based on Fuzzy Description Logics (DLs) can provide a foundation for reasoning in intelligent learning environments. While basic DLs are suitable for expressing crisp concepts and binary relationships, Fuzzy DLs are capable of processing degrees of truth/completene....../completeness about vague or imprecise information. This paper tackles the issue of representing fuzzy classes using OWL2 in a dataset describing Performance Assessment Results of Students (PARS)....

  1. Assessment of performance of survival prediction models for cancer prognosis

    Directory of Open Access Journals (Sweden)

    Chen Hung-Chia

    2012-07-01

    Full Text Available Abstract Background Cancer survival studies are commonly analyzed using survival-time prediction models for cancer prognosis. A number of different performance metrics are used to ascertain the concordance between the predicted risk score of each patient and the actual survival time, but these metrics can sometimes conflict. Alternatively, patients are sometimes divided into two classes according to a survival-time threshold, and binary classifiers are applied to predict each patient’s class. Although this approach has several drawbacks, it does provide natural performance metrics such as positive and negative predictive values to enable unambiguous assessments. Methods We compare the survival-time prediction and survival-time threshold approaches to analyzing cancer survival studies. We review and compare common performance metrics for the two approaches. We present new randomization tests and cross-validation methods to enable unambiguous statistical inferences for several performance metrics used with the survival-time prediction approach. We consider five survival prediction models consisting of one clinical model, two gene expression models, and two models from combinations of clinical and gene expression models. Results A public breast cancer dataset was used to compare several performance metrics using five prediction models. 1 For some prediction models, the hazard ratio from fitting a Cox proportional hazards model was significant, but the two-group comparison was insignificant, and vice versa. 2 The randomization test and cross-validation were generally consistent with the p-values obtained from the standard performance metrics. 3 Binary classifiers highly depended on how the risk groups were defined; a slight change of the survival threshold for assignment of classes led to very different prediction results. Conclusions 1 Different performance metrics for evaluation of a survival prediction model may give different conclusions in

  2. Lysimeter data as input to performance assessment models

    International Nuclear Information System (INIS)

    McConnell, J.W. Jr.

    1998-01-01

    The Field Lysimeter Investigations: Low-Level Waste Data Base Development Program is obtaining information on the performance of radioactive waste forms in a disposal environment. Waste forms fabricated using ion-exchange resins from EPICOR-117 prefilters employed in the cleanup of the Three Mile Island (TMI) Nuclear Power Station are being tested to develop a low-level waste data base and to obtain information on survivability of waste forms in a disposal environment. The program includes reviewing radionuclide releases from those waste forms in the first 7 years of sampling and examining the relationship between code input parameters and lysimeter data. Also, lysimeter data are applied to performance assessment source term models, and initial results from use of data in two models are presented

  3. Uncertainty assessment in building energy performance with a simplified model

    Directory of Open Access Journals (Sweden)

    Titikpina Fally

    2015-01-01

    Full Text Available To assess a building energy performance, the consumption being predicted or estimated during the design stage is compared to the measured consumption when the building is operational. When valuing this performance, many buildings show significant differences between the calculated and measured consumption. In order to assess the performance accurately and ensure the thermal efficiency of the building, it is necessary to evaluate the uncertainties involved not only in measurement but also those induced by the propagation of the dynamic and the static input data in the model being used. The evaluation of measurement uncertainty is based on both the knowledge about the measurement process and the input quantities which influence the result of measurement. Measurement uncertainty can be evaluated within the framework of conventional statistics presented in the Guide to the Expression of Measurement Uncertainty (GUM as well as by Bayesian Statistical Theory (BST. Another choice is the use of numerical methods like Monte Carlo Simulation (MCS. In this paper, we proposed to evaluate the uncertainty associated to the use of a simplified model for the estimation of the energy consumption of a given building. A detailed review and discussion of these three approaches (GUM, MCS and BST is given. Therefore, an office building has been monitored and multiple temperature sensors have been mounted on candidate locations to get required data. The monitored zone is composed of six offices and has an overall surface of 102 m2.

  4. Assigning probability distributions to input parameters of performance assessment models

    International Nuclear Information System (INIS)

    Mishra, Srikanta

    2002-02-01

    This study presents an overview of various approaches for assigning probability distributions to input parameters and/or future states of performance assessment models. Specifically,three broad approaches are discussed for developing input distributions: (a) fitting continuous distributions to data, (b) subjective assessment of probabilities, and (c) Bayesian updating of prior knowledge based on new information. The report begins with a summary of the nature of data and distributions, followed by a discussion of several common theoretical parametric models for characterizing distributions. Next, various techniques are presented for fitting continuous distributions to data. These include probability plotting, method of moments, maximum likelihood estimation and nonlinear least squares analysis. The techniques are demonstrated using data from a recent performance assessment study for the Yucca Mountain project. Goodness of fit techniques are also discussed, followed by an overview of how distribution fitting is accomplished in commercial software packages. The issue of subjective assessment of probabilities is dealt with in terms of the maximum entropy distribution selection approach, as well as some common rules for codifying informal expert judgment. Formal expert elicitation protocols are discussed next, and are based primarily on the guidance provided by the US NRC. The Bayesian framework for updating prior distributions (beliefs) when new information becomes available is discussed. A simple numerical approach is presented for facilitating practical applications of the Bayes theorem. Finally, a systematic framework for assigning distributions is presented: (a) for the situation where enough data are available to define an empirical CDF or fit a parametric model to the data, and (b) to deal with the situation where only a limited amount of information is available

  5. Assigning probability distributions to input parameters of performance assessment models

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Srikanta [INTERA Inc., Austin, TX (United States)

    2002-02-01

    This study presents an overview of various approaches for assigning probability distributions to input parameters and/or future states of performance assessment models. Specifically,three broad approaches are discussed for developing input distributions: (a) fitting continuous distributions to data, (b) subjective assessment of probabilities, and (c) Bayesian updating of prior knowledge based on new information. The report begins with a summary of the nature of data and distributions, followed by a discussion of several common theoretical parametric models for characterizing distributions. Next, various techniques are presented for fitting continuous distributions to data. These include probability plotting, method of moments, maximum likelihood estimation and nonlinear least squares analysis. The techniques are demonstrated using data from a recent performance assessment study for the Yucca Mountain project. Goodness of fit techniques are also discussed, followed by an overview of how distribution fitting is accomplished in commercial software packages. The issue of subjective assessment of probabilities is dealt with in terms of the maximum entropy distribution selection approach, as well as some common rules for codifying informal expert judgment. Formal expert elicitation protocols are discussed next, and are based primarily on the guidance provided by the US NRC. The Bayesian framework for updating prior distributions (beliefs) when new information becomes available is discussed. A simple numerical approach is presented for facilitating practical applications of the Bayes theorem. Finally, a systematic framework for assigning distributions is presented: (a) for the situation where enough data are available to define an empirical CDF or fit a parametric model to the data, and (b) to deal with the situation where only a limited amount of information is available.

  6. THE PENA BLANCA NATURAL ANALOGUE PERFORMANCE ASSESSMENT MODEL

    Energy Technology Data Exchange (ETDEWEB)

    G. Saulnier and W. Statham

    2006-04-16

    The Nopal I uranium mine in the Sierra Pena Blanca, Chihuahua, Mexico serves as a natural analogue to the Yucca Mountain repository. The Pena Blanca Natural Analogue Performance Assessment Model simulates the mobilization and transport of radionuclides that are released from the mine and transported to the saturated zone. The Pena Blanca Natural Analogue Performance Assessment Model uses probabilistic simulations of hydrogeologic processes that are analogous to the processes that occur at the Yucca Mountain site. The Nopal I uranium deposit lies in fractured, welded, and altered rhyolitic ash-flow tuffs that overlie carbonate rocks, a setting analogous to the geologic formations at the Yucca Mountain site. The Nopal I mine site has the following analogous characteristics as compared to the Yucca Mountain repository site: (1) Analogous source--UO{sub 2} uranium ore deposit = spent nuclear fuel in the repository; (2) Analogous geology--(i.e. fractured, welded, and altered rhyolitic ash-flow tuffs); (3) Analogous climate--Semiarid to arid; (4) Analogous setting--Volcanic tuffs overlie carbonate rocks; and (5) Analogous geochemistry--Oxidizing conditions Analogous hydrogeology: The ore deposit lies in the unsaturated zone above the water table.

  7. Models used to assess the performance of photovoltaic systems.

    Energy Technology Data Exchange (ETDEWEB)

    Stein, Joshua S.; Klise, Geoffrey T.

    2009-12-01

    This report documents the various photovoltaic (PV) performance models and software developed and utilized by researchers at Sandia National Laboratories (SNL) in support of the Photovoltaics and Grid Integration Department. In addition to PV performance models, hybrid system and battery storage models are discussed. A hybrid system using other distributed sources and energy storage can help reduce the variability inherent in PV generation, and due to the complexity of combining multiple generation sources and system loads, these models are invaluable for system design and optimization. Energy storage plays an important role in reducing PV intermittency and battery storage models are used to understand the best configurations and technologies to store PV generated electricity. Other researcher's models used by SNL are discussed including some widely known models that incorporate algorithms developed at SNL. There are other models included in the discussion that are not used by or were not adopted from SNL research but may provide some benefit to researchers working on PV array performance, hybrid system models and energy storage. The paper is organized into three sections to describe the different software models as applied to photovoltaic performance, hybrid systems, and battery storage. For each model, there is a description which includes where to find the model, whether it is currently maintained and any references that may be available. Modeling improvements underway at SNL include quantifying the uncertainty of individual system components, the overall uncertainty in modeled vs. measured results and modeling large PV systems. SNL is also conducting research into the overall reliability of PV systems.

  8. Construction Of A Performance Assessment Model For Zakat Management Institutions

    Directory of Open Access Journals (Sweden)

    Sri Fadilah

    2016-12-01

    Full Text Available The objective of the research is to examine the performance evaluation using Balanced Scorecard model. The research is conducted due to a big gap existing between zakat (alms and religious tax in Islam with its potential earn of as much as 217 trillion rupiahs and the realization of the collected zakat fund that is only reached for three trillion. This indicates that the performance of zakat management organizations in collecting the zakat is still very low. On the other hand, the quantity and the quality of zakat management organizations have to be improved. This means the performance evaluation model as a tool to evaluate performance is needed. The model construct is making a performance evaluation model that can be implemented to zakat management organizations. The organizational performance with Balanced Scorecard evaluation model will be effective if it is supported by three aspects, namely:  PI, BO and TQM. This research uses explanatory method and data analysis tool of SEM/PLS. Data collecting technique are questionnaires, interviews and documentation. The result of this research shows that PI, BO and TQM simultaneously and partially gives a significant effect on organizational performance.

  9. Activity-Based Costing Model for Assessing Economic Performance.

    Science.gov (United States)

    DeHayes, Daniel W.; Lovrinic, Joseph G.

    1994-01-01

    An economic model for evaluating the cost performance of academic and administrative programs in higher education is described. Examples from its application at Indiana University-Purdue University Indianapolis are used to illustrate how the model has been used to control costs and reengineer processes. (Author/MSE)

  10. THE PENA BLANCA NATURAL ANALOGUE PERFORMANCE ASSESSMENT MODEL

    International Nuclear Information System (INIS)

    G.J. Saulnier Jr; W. Statham

    2006-01-01

    The Nopal I uranium mine in the Sierra Pena Blanca, Chihuahua, Mexico serves as a natural analogue to the Yucca Mountain repository. The Pena Blanca Natural Analogue Performance Assessment Model simulates the mobilization and transport of radionuclides that are released from the mine and transported to the saturated zone. the Pena Blanca Natural Analogue Model uses probabilistic simulations of hydrogeologic processes that are analogous to the processes that occur at the Yucca Mountain site. The Nopal I uranium deposit lies in fractured, welded, and altered rhyolitic ash flow tuffs that overlie carbonate rocks, a setting analogous to the geologic formations at the Yucca Mountain site. The Nopal I mine site has the following characteristics as compared to the Yucca Mountain repository site. (1) Analogous source: UO 2 uranium ore deposit = spent nuclear fuel in the repository; (2) Analogous geologic setting: fractured, welded, and altered rhyolitic ash flow tuffs overlying carbonate rocks; (3) Analogous climate: Semiarid to arid; (4) Analogous geochemistry: Oxidizing conditions; and (5) Analogous hydrogeology: The ore deposit lies in the unsaturated zone above the water table. The Nopal I deposit is approximately 8 ± 0.5 million years old and has been exposed to oxidizing conditions during the last 3.2 to 3.4 million years. The Pena Blanca Natural Analogue Model considers that the uranium oxide and uranium silicates in the ore deposit were originally analogous to uranium-oxide spent nuclear fuel. The Pena Blanca site has been characterized using field and laboratory investigations of its fault and fracture distribution, mineralogy, fracture fillings, seepage into the mine adits, regional hydrology, and mineralization that shows the extent of radionuclide migration. Three boreholes were drilled at the Nopal I mine site in 2003 and these boreholes have provided samples for lithologic characterization, water-level measurements, and water samples for laboratory analysis

  11. THE PENA BLANCA NATURAL ANALOGUE PERFORMANCE ASSESSMENT MODEL

    Energy Technology Data Exchange (ETDEWEB)

    G.J. Saulnier Jr; W. Statham

    2006-03-10

    The Nopal I uranium mine in the Sierra Pena Blanca, Chihuahua, Mexico serves as a natural analogue to the Yucca Mountain repository. The Pena Blanca Natural Analogue Performance Assessment Model simulates the mobilization and transport of radionuclides that are released from the mine and transported to the saturated zone. the Pena Blanca Natural Analogue Model uses probabilistic simulations of hydrogeologic processes that are analogous to the processes that occur at the Yucca Mountain site. The Nopal I uranium deposit lies in fractured, welded, and altered rhyolitic ash flow tuffs that overlie carbonate rocks, a setting analogous to the geologic formations at the Yucca Mountain site. The Nopal I mine site has the following characteristics as compared to the Yucca Mountain repository site. (1) Analogous source: UO{sub 2} uranium ore deposit = spent nuclear fuel in the repository; (2) Analogous geologic setting: fractured, welded, and altered rhyolitic ash flow tuffs overlying carbonate rocks; (3) Analogous climate: Semiarid to arid; (4) Analogous geochemistry: Oxidizing conditions; and (5) Analogous hydrogeology: The ore deposit lies in the unsaturated zone above the water table. The Nopal I deposit is approximately 8 {+-} 0.5 million years old and has been exposed to oxidizing conditions during the last 3.2 to 3.4 million years. The Pena Blanca Natural Analogue Model considers that the uranium oxide and uranium silicates in the ore deposit were originally analogous to uranium-oxide spent nuclear fuel. The Pena Blanca site has been characterized using field and laboratory investigations of its fault and fracture distribution, mineralogy, fracture fillings, seepage into the mine adits, regional hydrology, and mineralization that shows the extent of radionuclide migration. Three boreholes were drilled at the Nopal I mine site in 2003 and these boreholes have provided samples for lithologic characterization, water-level measurements, and water samples for laboratory

  12. Modeling Logistic Performance in Quantitative Microbial Risk Assessment

    NARCIS (Netherlands)

    Rijgersberg, H.; Tromp, S.O.; Jacxsens, L.; Uyttendaele, M.

    2010-01-01

    In quantitative microbial risk assessment (QMRA), food safety in the food chain is modeled and simulated. In general, prevalences, concentrations, and numbers of microorganisms in media are investigated in the different steps from farm to fork. The underlying rates and conditions (such as storage

  13. Simplified Predictive Models for CO2 Sequestration Performance Assessment

    Science.gov (United States)

    Mishra, Srikanta; RaviGanesh, Priya; Schuetter, Jared; Mooney, Douglas; He, Jincong; Durlofsky, Louis

    2014-05-01

    We present results from an ongoing research project that seeks to develop and validate a portfolio of simplified modeling approaches that will enable rapid feasibility and risk assessment for CO2 sequestration in deep saline formation. The overall research goal is to provide tools for predicting: (a) injection well and formation pressure buildup, and (b) lateral and vertical CO2 plume migration. Simplified modeling approaches that are being developed in this research fall under three categories: (1) Simplified physics-based modeling (SPM), where only the most relevant physical processes are modeled, (2) Statistical-learning based modeling (SLM), where the simulator is replaced with a "response surface", and (3) Reduced-order method based modeling (RMM), where mathematical approximations reduce the computational burden. The system of interest is a single vertical well injecting supercritical CO2 into a 2-D layered reservoir-caprock system with variable layer permeabilities. In the first category (SPM), we use a set of well-designed full-physics compositional simulations to understand key processes and parameters affecting pressure propagation and buoyant plume migration. Based on these simulations, we have developed correlations for dimensionless injectivity as a function of the slope of fractional-flow curve, variance of layer permeability values, and the nature of vertical permeability arrangement. The same variables, along with a modified gravity number, can be used to develop a correlation for the total storage efficiency within the CO2 plume footprint. In the second category (SLM), we develop statistical "proxy models" using the simulation domain described previously with two different approaches: (a) classical Box-Behnken experimental design with a quadratic response surface fit, and (b) maximin Latin Hypercube sampling (LHS) based design with a Kriging metamodel fit using a quadratic trend and Gaussian correlation structure. For roughly the same number of

  14. Literature Review and Assessment of Plant and Animal Transfer Factors Used in Performance Assessment Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, David E.; Cataldo, Dominic A.; Napier, Bruce A.; Krupka, Kenneth M.; Sasser, Lyle B.

    2003-07-20

    A literature review and assessment was conducted by Pacific Northwest National Laboratory (PNNL) to update information on plant and animal radionuclide transfer factors used in performance-assessment modeling. A group of 15 radionuclides was included in this review and assessment. The review is composed of four main sections, not including the Introduction. Section 2.0 provides a review of the critically important issue of physicochemical speciation and geochemistry of the radionuclides in natural soil-water systems as it relates to the bioavailability of the radionuclides. Section 3.0 provides an updated review of the parameters of importance in the uptake of radionuclides by plants, including root uptake via the soil-groundwater system and foliar uptake due to overhead irrigation. Section 3.0 also provides a compilation of concentration ratios (CRs) for soil-to-plant uptake for the 15 selected radionuclides. Section 4.0 provides an updated review on radionuclide uptake data for animal products related to absorption, homeostatic control, approach to equilibration, chemical and physical form, diet, and age. Compiled transfer coefficients are provided for cow’s milk, sheep’s milk, goat’s milk, beef, goat meat, pork, poultry, and eggs. Section 5.0 discusses the use of transfer coefficients in soil, plant, and animal modeling using regulatory models for evaluating radioactive waste disposal or decommissioned sites. Each section makes specific suggestions for future research in its area.

  15. Sensitivity of hydrological performance assessment analysis to variations in material properties, conceptual models, and ventilation models

    Energy Technology Data Exchange (ETDEWEB)

    Sobolik, S.R.; Ho, C.K.; Dunn, E. [Sandia National Labs., Albuquerque, NM (United States); Robey, T.H. [Spectra Research Inst., Albuquerque, NM (United States); Cruz, W.T. [Univ. del Turabo, Gurabo (Puerto Rico)

    1996-07-01

    The Yucca Mountain Site Characterization Project is studying Yucca Mountain in southwestern Nevada as a potential site for a high-level nuclear waste repository. Site characterization includes surface- based and underground testing. Analyses have been performed to support the design of an Exploratory Studies Facility (ESF) and the design of the tests performed as part of the characterization process, in order to ascertain that they have minimal impact on the natural ability of the site to isolate waste. The information in this report pertains to sensitivity studies evaluating previous hydrological performance assessment analyses to variation in the material properties, conceptual models, and ventilation models, and the implications of this sensitivity on previous recommendations supporting ESF design. This document contains information that has been used in preparing recommendations for Appendix I of the Exploratory Studies Facility Design Requirements document.

  16. Sensitivity of hydrological performance assessment analysis to variations in material properties, conceptual models, and ventilation models

    International Nuclear Information System (INIS)

    Sobolik, S.R.; Ho, C.K.; Dunn, E.; Robey, T.H.; Cruz, W.T.

    1996-07-01

    The Yucca Mountain Site Characterization Project is studying Yucca Mountain in southwestern Nevada as a potential site for a high-level nuclear waste repository. Site characterization includes surface- based and underground testing. Analyses have been performed to support the design of an Exploratory Studies Facility (ESF) and the design of the tests performed as part of the characterization process, in order to ascertain that they have minimal impact on the natural ability of the site to isolate waste. The information in this report pertains to sensitivity studies evaluating previous hydrological performance assessment analyses to variation in the material properties, conceptual models, and ventilation models, and the implications of this sensitivity on previous recommendations supporting ESF design. This document contains information that has been used in preparing recommendations for Appendix I of the Exploratory Studies Facility Design Requirements document

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

    DEFF Research Database (Denmark)

    Tina, Giuseppe; Ventura, Cristina; Sera, Dezso

    2017-01-01

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

  18. Model-supported selection of distribution coefficients for performance assessment

    International Nuclear Information System (INIS)

    Ochs, M.; Lothenbach, B.; Shibata, Hirokazu; Yui, Mikazu

    1999-01-01

    A thermodynamic speciation/sorption model is used to illustrate typical problems encountered in the extrapolation of batch-type K d values to repository conditions. For different bentonite-groundwater systems, the composition of the corresponding equilibrium solutions and the surface speciation of the bentonite is calculated by treating simultaneously solution equilibria of soluble components of the bentonite as well as ion exchange and acid/base reactions at the bentonite surface. K d values for Cs, Ra, and Ni are calculated by implementing the appropriate ion exchange and surface complexation equilibria in the bentonite model. Based on this approach, hypothetical batch experiments are contrasted with expected conditions in compacted backfill. For each of these scenarios, the variation of K d values as a function of groundwater composition is illustrated for Cs, Ra, and Ni. The applicability of measured, batch-type K d values to repository conditions is discussed. (author)

  19. SR 97 - Alternative models project. Discrete fracture network modelling for performance assessment of Aberg

    International Nuclear Information System (INIS)

    Dershowitz, B.; Eiben, T.; Follin, S.; Andersson, Johan

    1999-08-01

    As part of studies into the siting of a deep repository for nuclear waste, Swedish Nuclear Fuel and Waste Management Company (SKB) has commissioned the Alternative Models Project (AMP). The AMP is a comparison of three alternative modeling approaches for geosphere performance assessment for a single hypothetical site. The hypothetical site, arbitrarily named Aberg is based on parameters from the Aespoe Hard Rock Laboratory in southern Sweden. The Aberg model domain, boundary conditions and canister locations are defined as a common reference case to facilitate comparisons between approaches. This report presents the results of a discrete fracture pathways analysis of the Aberg site, within the context of the SR 97 performance assessment exercise. The Aberg discrete fracture network (DFN) site model is based on consensus Aberg parameters related to the Aespoe HRL site. Discrete fracture pathways are identified from canister locations in a prototype repository design to the surface of the island or to the sea bottom. The discrete fracture pathways analysis presented in this report is used to provide the following parameters for SKB's performance assessment transport codes FARF31 and COMP23: * F-factor: Flow wetted surface normalized with regards to flow rate (yields an appreciation of the contact area available for diffusion and sorption processes) [TL -1 ]. * Travel Time: Advective transport time from a canister location to the environmental discharge [T]. * Canister Flux: Darcy flux (flow rate per unit area) past a representative canister location [LT -1 ]. In addition to the above, the discrete fracture pathways analysis in this report also provides information about: additional pathway parameters such as pathway length, pathway width, transport aperture, reactive surface area and transmissivity, percentage of canister locations with pathways to the surface discharge, spatial pattern of pathways and pathway discharges, visualization of pathways, and statistical

  20. SR 97 - Alternative models project. Discrete fracture network modelling for performance assessment of Aberg

    Energy Technology Data Exchange (ETDEWEB)

    Dershowitz, B.; Eiben, T. [Golder Associates Inc., Seattle (United States); Follin, S.; Andersson, Johan [Golder Grundteknik KB, Stockholm (Sweden)

    1999-08-01

    As part of studies into the siting of a deep repository for nuclear waste, Swedish Nuclear Fuel and Waste Management Company (SKB) has commissioned the Alternative Models Project (AMP). The AMP is a comparison of three alternative modeling approaches for geosphere performance assessment for a single hypothetical site. The hypothetical site, arbitrarily named Aberg is based on parameters from the Aespoe Hard Rock Laboratory in southern Sweden. The Aberg model domain, boundary conditions and canister locations are defined as a common reference case to facilitate comparisons between approaches. This report presents the results of a discrete fracture pathways analysis of the Aberg site, within the context of the SR 97 performance assessment exercise. The Aberg discrete fracture network (DFN) site model is based on consensus Aberg parameters related to the Aespoe HRL site. Discrete fracture pathways are identified from canister locations in a prototype repository design to the surface of the island or to the sea bottom. The discrete fracture pathways analysis presented in this report is used to provide the following parameters for SKB's performance assessment transport codes FARF31 and COMP23: * F-factor: Flow wetted surface normalized with regards to flow rate (yields an appreciation of the contact area available for diffusion and sorption processes) [TL{sup -1}]. * Travel Time: Advective transport time from a canister location to the environmental discharge [T]. * Canister Flux: Darcy flux (flow rate per unit area) past a representative canister location [LT{sup -1}]. In addition to the above, the discrete fracture pathways analysis in this report also provides information about: additional pathway parameters such as pathway length, pathway width, transport aperture, reactive surface area and transmissivity, percentage of canister locations with pathways to the surface discharge, spatial pattern of pathways and pathway discharges, visualization of pathways, and

  1. Econometric model as a regulatory tool in electricity distribution - Case Network Performance Assessment Model

    International Nuclear Information System (INIS)

    Honkapuro, S.; Lassila, J.; Viljainen, S.; Tahvanainen, K.; Partanen, J.

    2004-01-01

    Electricity distribution companies operate in the state of natural monopolies since building of parallel networks is not cost-effective. Monopoly companies do not have pressure from the open markets to keep their prices and costs at reasonable level. The regulation of these companies is needed to prevent the misuse of the monopoly position. Regulation is usually focused either on the profit of company or on the price of electricity. In this document, the usability of an econometric model in the regulation of electricity distribution companies is evaluated. Regulation method which determines allowed income for each company with generic computation model can be seen as an econometric model. As the special case of an econometric model, the method called Network Performance Assessment Model, NPAM (Naetnyttomodellen in Swedish), is analysed. NPAM is developed by Swedish Energy Agency (STEM) for the regulation of electricity distribution companies. Both theoretical analysis and calculations of an example network area are presented in this document to find the major directing effects of the model. The parameters of NPAM, which are used in the calculations of this research report, were dated on 30th of March 2004. These parameters were most recent available at the time when analysis was done. However, since NPAM is under development, the parameters have been constantly changing. Therefore slightly changes in the results can occur if calculations were made with latest parameters. However, main conclusions are same and do not depend on exact parameters. (orig.)

  2. Econometric model as a regulatory tool in electricity distribution. Case network performance assessment model

    International Nuclear Information System (INIS)

    Honkapuro, S.; Lassila, J.; Viljainen, S.; Tahvanainen, K.; Partanen, J.

    2004-01-01

    Electricity distribution companies operate in the state of natural monopolies since building of parallel networks is not cost- effective. Monopoly companies do not have pressure from the open markets to keep their prices and costs at reasonable level. The regulation of these companies is needed to prevent the misuse of the monopoly position. Regulation is usually focused either on the profit of company or on the price of electricity. Regulation method which determines allowed income for each company with generic computation model can be seen as an econometric model. In this document, the usability of an econometric model in the regulation of electricity distribution companies is evaluated. As the special case of an econometric model, the method called Network Performance Assessment Model, NPAM (Naetnyttomodellen in Swedish), is analysed. NPAM is developed by Swedish Energy Agency (STEM) for the regulation of electricity distribution companies. Both theoretical analysis and calculations of an example network area are presented in this document to find the major directing effects of the model. The parameters of NPAM, which are used in the calculations of this research report, were dated on 30th of March 2004. These parameters were most recent ones available at the time when analysis was done. However, since NPAM have been under development, the parameters have been constantly changing. Therefore slight changes might occur in the numerical results of calculations if they were made with the latest set of parameters. However, main conclusions are same and do not depend on exact parameters

  3. Performance Requirements Modeling andAssessment for Active Power Ancillary Services

    DEFF Research Database (Denmark)

    Bondy, Daniel Esteban Morales; Thavlov, Anders; Tougaard, Janus Bundsgaard Mosbæk

    2017-01-01

    system operation, a reliable service delivery is required, yet it may not be appropriate to apply conventional performance requirements to new technologies and methods. The service performance requirements and assessment methods therefore need to be generalized and standardized in order to include future...... ancillary service sources. This paper develops a modeling method for ancillary services performance requirements, including performance and verification indices. The use of the modeling method and the indices is exemplified in two case studies....

  4. Assessing the performance of prediction models: A framework for traditional and novel measures

    NARCIS (Netherlands)

    E.W. Steyerberg (Ewout); A.J. Vickers (Andrew); N.R. Cook (Nancy); T.A. Gerds (Thomas); M. Gonen (Mithat); N. Obuchowski (Nancy); M. Pencina (Michael); M.W. Kattan (Michael)

    2010-01-01

    textabstractThe performance of prediction models can be assessed using a variety of methods and metrics. Traditional measures for binary and survival outcomes include the Brier score to indicate overall model performance, the concordance (or c) statistic for discriminative ability (or area under the

  5. Bayesian Comparison of Alternative Graded Response Models for Performance Assessment Applications

    Science.gov (United States)

    Zhu, Xiaowen; Stone, Clement A.

    2012-01-01

    This study examined the relative effectiveness of Bayesian model comparison methods in selecting an appropriate graded response (GR) model for performance assessment applications. Three popular methods were considered: deviance information criterion (DIC), conditional predictive ordinate (CPO), and posterior predictive model checking (PPMC). Using…

  6. Process of performance assessment

    International Nuclear Information System (INIS)

    King, C.M.; Halford, D.K.

    1987-01-01

    Performance assessment is the process used to evaluate the environmental consequences of disposal of radioactive waste in the biosphere. An introductory review of the subject is presented. Emphasis is placed on the process of performance assessment from the standpoint of defining the process. Performance assessment, from evolving experience at DOE sites, has short-term and long-term subprograms, the components of which are discussed. The role of mathematical modeling in performance assessment is addressed including the pros and cons of current approaches. Finally, the system/site/technology issues as the focal point of this symposium are reviewed

  7. Maneuver Performance Assessment of the Cassini Spacecraft Through Execution-Error Modeling and Analysis

    Science.gov (United States)

    Wagner, Sean

    2014-01-01

    The Cassini spacecraft has executed nearly 300 maneuvers since 1997, providing ample data for execution-error model updates. With maneuvers through 2017, opportunities remain to improve on the models and remove biases identified in maneuver executions. This manuscript focuses on how execution-error models can be used to judge maneuver performance, while providing a means for detecting performance degradation. Additionally, this paper describes Cassini's execution-error model updates in August 2012. An assessment of Cassini's maneuver performance through OTM-368 on January 5, 2014 is also presented.

  8. SR 97. Alternative models project. Channel network modelling of Aberg. Performance assessment using CHAN3D

    International Nuclear Information System (INIS)

    Gylling, B.; Moreno, L.; Neretnieks, I.

    1999-06-01

    In earlier papers, discussions of the mechanisms which are important in performance assessment in fractured media are given. The influence of the mechanisms have been demonstrated using CHAN3D. In this study CHAN3D has been used to simulate production of input data to COMP23 and FARF31. CHAN3D has been integrated with COMP23 in earlier studies, but it has not been used before to calculate input data to FARF31. In the normal use of CHAN3D, the transport part of the concept simulates far field migration. The task in this study was to produce input data according to a specification and using a defined hypothetical repository located at Aespoe HRL as a platform. During the process of applying CHAN3D to the site, the scaling of conductivity was studied, using both data from Aespoe HRL and synthetic data. From the realisations performed, ensemble statistics of water travel time, flux at repository scale, flow-wetted surface and F-ratio values were calculated. Two typical realisations were studied in more detail. The results for three specified canister positions were also highlighted. Exit locations for the released particles were studied. In each realisation statistics were calculated over the entities. The values were post-processed to obtain performance measures of higher order. From the averaging over all the realisations it can be concluded that the Monte Carlo stability is reached for the ensemble statistics. The presence of fracture zones has a large influence on flow and transport in the rock. However, for a single canister the result may be very different between realisations. In some realisations there may be a fast path to a fracture zone whereas in other realisations the opposite may be valid. From the calculation of the flow over the boundaries between the regional model and the smaller local model the consistency seem to be acceptable considering that a perfect match of properties is hard to obtain

  9. Methods to assess performance of models estimating risk of death in intensive care patients: a review.

    Science.gov (United States)

    Cook, D A

    2006-04-01

    Models that estimate the probability of death of intensive care unit patients can be used to stratify patients according to the severity of their condition and to control for casemix and severity of illness. These models have been used for risk adjustment in quality monitoring, administration, management and research and as an aid to clinical decision making. Models such as the Mortality Prediction Model family, SAPS II, APACHE II, APACHE III and the organ system failure models provide estimates of the probability of in-hospital death of ICU patients. This review examines methods to assess the performance of these models. The key attributes of a model are discrimination (the accuracy of the ranking in order of probability of death) and calibration (the extent to which the model's prediction of probability of death reflects the true risk of death). These attributes should be assessed in existing models that predict the probability of patient mortality, and in any subsequent model that is developed for the purposes of estimating these probabilities. The literature contains a range of approaches for assessment which are reviewed and a survey of the methodologies used in studies of intensive care mortality models is presented. The systematic approach used by Standards for Reporting Diagnostic Accuracy provides a framework to incorporate these theoretical considerations of model assessment and recommendations are made for evaluation and presentation of the performance of models that estimate the probability of death of intensive care patients.

  10. On the importance of observational data properties when assessing regional climate model performance of extreme precipitation

    DEFF Research Database (Denmark)

    Sunyer Pinya, Maria Antonia; Sørup, Hjalte Jomo Danielsen; Christensen, Ole Bøssing

    2013-01-01

    In recent years, there has been an increase in the number of climate studies addressing changes in extreme precipitation. A common step in these studies involves the assessment of the climate model performance. This is often measured by comparing climate model output with observational data. In t...

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

    International Nuclear Information System (INIS)

    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

  12. Business performance assessment and the EFQM Excellence Model 2010 (case study

    Directory of Open Access Journals (Sweden)

    Mária Antošová

    2015-01-01

    Full Text Available The application of the latest management methods becomes today, during the ongoing European integration processes, a requisite for the success of the business within the environment of international markets. In this paper, the authors pay attention to the expansion of the organizational knowledge base with an application of a new management method. They are dealing with assessment of the organization performance, the issue of its effectiveness and the increasing economic efficiency, on an example of a selected mining company as a case study. In order to detect weaknesses in the company reviewed and to offer suggestions for improvement, which may move the company towards prosperity, the authors carried out the performance assessment by using the EFQM Excellence Model 2010. The aim of this paper is to introduce the business performance assessment model in terms of the European standards that will allow the use of latest management methods in the environment of both the Slovak and European companies.

  13. Assessing the Performance of a Northern Gulf of Mexico Tidal Model Using Satellite Imagery

    Directory of Open Access Journals (Sweden)

    Stephen C. Medeiros

    2013-11-01

    Full Text Available Tidal harmonic analysis simulations along with simulations spanning four specific historical time periods in 2003 and 2004 were conducted to test the performance of a northern Gulf of Mexico tidal model. A recently developed method for detecting inundated areas based on integrated remotely sensed data (i.e., Radarsat-1, aerial imagery, LiDAR, Landsat 7 ETM+ was applied to assess the performance of the tidal model. The analysis demonstrates the applicability of the method and its agreement with traditional performance assessment techniques such as harmonic resynthesis and water level time series analysis. Based on the flooded/non-flooded coastal areas estimated by the integrated remotely sensed data, the model is able to adequately reproduce the extent of inundation within four sample areas from the coast along the Florida panhandle, correctly identifying areas as wet or dry over 85% of the time. Comparisons of the tidal model inundation to synoptic (point-in-time inundation areas generated from the remotely sensed data generally agree with the results of the traditional performance assessment techniques. Moreover, this approach is able to illustrate the spatial distribution of model inundation accuracy allowing for targeted refinement of model parameters.

  14. Some concepts of model uncertainty for performance assessments of nuclear waste repositories

    International Nuclear Information System (INIS)

    Eisenberg, N.A.; Sagar, B.; Wittmeyer, G.W.

    1994-01-01

    Models of the performance of nuclear waste repositories will be central to making regulatory decisions regarding the safety of such facilities. The conceptual model of repository performance is represented by mathematical relationships, which are usually implemented as one or more computer codes. A geologic system may allow many conceptual models, which are consistent with the observations. These conceptual models may or may not have the same mathematical representation. Experiences in modeling the performance of a waste repository representation. Experiences in modeling the performance of a waste repository (which is, in part, a geologic system), show that this non-uniqueness of conceptual models is a significant source of model uncertainty. At the same time, each conceptual model has its own set of parameters and usually, it is not be possible to completely separate model uncertainty from parameter uncertainty for the repository system. Issues related to the origin of model uncertainty, its relation to parameter uncertainty, and its incorporation in safety assessments are discussed from a broad regulatory perspective. An extended example in which these issues are explored numerically is also provided

  15. Using Performance Assessment Model in Physics Laboratory to Increase Students’ Critical Thinking Disposition

    Science.gov (United States)

    Emiliannur, E.; Hamidah, I.; Zainul, A.; Wulan, A. R.

    2017-09-01

    Performance Assessment Model (PAM) has been developed to represent the physics concepts which able to be devided into five experiments: 1) acceleration due to gravity; 2) Hooke’s law; 3) simple harmonic motion; 4) work-energy concepts; and 5) the law of momentum conservation. The aim of this study was to determine the contribution of PAM in physics laboratory to increase students’ Critical Thinking Disposition (CTD) at senior high school. Subject of the study were 11th grade consist 32 students of a senior high school in Lubuk Sikaping, West Sumatera. The research used one group pretest-postest design. Data was collected through essay test and questionnaire about CTD. Data was analyzed using quantitative way with N-gain value. This study concluded that performance assessmet model effectively increases the N-gain at medium category. It means students’ critical thinking disposition significant increase after implementation of performance assessment model in physics laboratory.

  16. An Assessment of Mean Areal Precipitation Methods on Simulated Stream Flow: A SWAT Model Performance Assessment

    Directory of Open Access Journals (Sweden)

    Sean Zeiger

    2017-06-01

    Full Text Available Accurate mean areal precipitation (MAP estimates are essential input forcings for hydrologic models. However, the selection of the most accurate method to estimate MAP can be daunting because there are numerous methods to choose from (e.g., proximate gauge, direct weighted average, surface-fitting, and remotely sensed methods. Multiple methods (n = 19 were used to estimate MAP with precipitation data from 11 distributed monitoring sites, and 4 remotely sensed data sets. Each method was validated against the hydrologic model simulated stream flow using the Soil and Water Assessment Tool (SWAT. SWAT was validated using a split-site method and the observed stream flow data from five nested-scale gauging sites in a mixed-land-use watershed of the central USA. Cross-validation results showed the error associated with surface-fitting and remotely sensed methods ranging from −4.5 to −5.1%, and −9.8 to −14.7%, respectively. Split-site validation results showed the percent bias (PBIAS values that ranged from −4.5 to −160%. Second order polynomial functions especially overestimated precipitation and subsequent stream flow simulations (PBIAS = −160 in the headwaters. The results indicated that using an inverse-distance weighted, linear polynomial interpolation or multiquadric function method to estimate MAP may improve SWAT model simulations. Collectively, the results highlight the importance of spatially distributed observed hydroclimate data for precipitation and subsequent steam flow estimations. The MAP methods demonstrated in the current work can be used to reduce hydrologic model uncertainty caused by watershed physiographic differences.

  17. Seismic assessment and performance of nonstructural components affected by structural modeling

    Energy Technology Data Exchange (ETDEWEB)

    Hur, Jieun; Althoff, Eric; Sezen, Halil; Denning, Richard; Aldemir, Tunc [Ohio State University, Columbus (United States)

    2017-03-15

    Seismic probabilistic risk assessment (SPRA) requires a large number of simulations to evaluate the seismic vulnerability of structural and nonstructural components in nuclear power plants. The effect of structural modeling and analysis assumptions on dynamic analysis of 3D and simplified 2D stick models of auxiliary buildings and the attached nonstructural components is investigated. Dynamic characteristics and seismic performance of building models are also evaluated, as well as the computational accuracy of the models. The presented results provide a better understanding of the dynamic behavior and seismic performance of auxiliary buildings. The results also help to quantify the impact of uncertainties associated with modeling and analysis of simplified numerical models of structural and nonstructural components subjected to seismic shaking on the predicted seismic failure probabilities of these systems.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yim, M.S.; Su, S.I. [North Carolina State Univ., Raleigh, NC (United States)

    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.

  19. Biosphere Modeling and Analyses in Support of Total System Performance Assessment

    International Nuclear Information System (INIS)

    Tappen, J. J.; Wasiolek, M. A.; Wu, D. W.; Schmitt, J. F.; Smith, A. J.

    2002-01-01

    The Nuclear Waste Policy Act of 1982 established the obligations of and the relationship between the U.S. Environmental Protection Agency (EPA), the U.S. Nuclear Regulatory Commission (NRC), and the U.S. Department of Energy (DOE) for the management and disposal of high-level radioactive wastes. In 1985, the EPA promulgated regulations that included a definition of performance assessment that did not consider potential dose to a member of the general public. This definition would influence the scope of activities conducted by DOE in support of the total system performance assessment program until 1995. The release of a National Academy of Sciences (NAS) report on the technical basis for a Yucca Mountain-specific standard provided the impetus for the DOE to initiate activities that would consider the attributes of the biosphere, i.e. that portion of the earth where living things, including man, exist and interact with the environment around them. The evolution of NRC and EPA Yucca Mountain-specific regulations, originally proposed in 1999, was critical to the development and integration of biosphere modeling and analyses into the total system performance assessment program. These proposed regulations initially differed in the conceptual representation of the receptor of interest to be considered in assessing performance. The publication in 2001 of final regulations in which the NRC adopted standard will permit the continued improvement and refinement of biosphere modeling and analyses activities in support of assessment activities

  20. Biosphere Modeling and Analyses in Support of Total System Performance Assessment

    International Nuclear Information System (INIS)

    Jeff Tappen; M.A. Wasiolek; D.W. Wu; J.F. Schmitt

    2001-01-01

    The Nuclear Waste Policy Act of 1982 established the obligations of and the relationship between the U.S. Environmental Protection Agency (EPA), the U.S. Nuclear Regulatory Commission (NRC), and the U.S. Department of Energy (DOE) for the management and disposal of high-level radioactive wastes. In 1985, the EPA promulgated regulations that included a definition of performance assessment that did not consider potential dose to a member of the general public. This definition would influence the scope of activities conducted by DOE in support of the total system performance assessment program until 1995. The release of a National Academy of Sciences (NAS) report on the technical basis for a Yucca Mountain-specific standard provided the impetus for the DOE to initiate activities that would consider the attributes of the biosphere, i.e. that portion of the earth where living things, including man, exist and interact with the environment around them. The evolution of NRC and EPA Yucca Mountain-specific regulations, originally proposed in 1999, was critical to the development and integration of biosphere modeling and analyses into the total system performance assessment program. These proposed regulations initially differed in the conceptual representation of the receptor of interest to be considered in assessing performance. The publication in 2001 of final regulations in which the NRC adopted standard will permit the continued improvement and refinement of biosphere modeling and analyses activities in support of assessment activities

  1. Probabilistic performance-assessment modeling of the mixed waste landfill at Sandia National Laboratories.

    Energy Technology Data Exchange (ETDEWEB)

    Peace, Gerald (Jerry) L. (.); Goering, Timothy James (GRAM, Inc.); Miller, Mark Laverne; Ho, Clifford Kuofei

    2007-01-01

    A probabilistic performance assessment has been conducted to evaluate the fate and transport of radionuclides (americium-241, cesium-137, cobalt-60, plutonium-238, plutonium-239, radium-226, radon-222, strontium-90, thorium-232, tritium, uranium-238), heavy metals (lead and cadmium), and volatile organic compounds (VOCs) at the Mixed Waste Landfill (MWL). Probabilistic analyses were performed to quantify uncertainties inherent in the system and models for a 1,000-year period, and sensitivity analyses were performed to identify parameters and processes that were most important to the simulated performance metrics. Comparisons between simulated results and measured values at the MWL were made to gain confidence in the models and perform calibrations when data were available. In addition, long-term monitoring requirements and triggers were recommended based on the results of the quantified uncertainty and sensitivity analyses.

  2. SUMO, System performance assessment for a high-level nuclear waste repository: Mathematical models

    International Nuclear Information System (INIS)

    Eslinger, P.W.; Miley, T.B.; Engel, D.W.; Chamberlain, P.J. II.

    1992-09-01

    Following completion of the preliminary risk assessment of the potential Yucca Mountain Site by Pacific Northwest Laboratory (PNL) in 1988, the Office of Civilian Radioactive Waste Management (OCRWM) of the US Department of Energy (DOE) requested the Performance Assessment Scientific Support (PASS) Program at PNL to develop an integrated system model and computer code that provides performance and risk assessment analysis capabilities for a potential high-level nuclear waste repository. The system model that has been developed addresses the cumulative radionuclide release criteria established by the US Environmental Protection Agency (EPA) and estimates population risks in terms of dose to humans. The system model embodied in the SUMO (System Unsaturated Model) code will also allow benchmarking of other models being developed for the Yucca Mountain Project. The system model has three natural divisions: (1) source term, (2) far-field transport, and (3) dose to humans. This document gives a detailed description of the mathematics of each of these three divisions. Each of the governing equations employed is based on modeling assumptions that are widely accepted within the scientific community

  3. Model of practical skill performance as an instrument for supervision and formative assessment

    DEFF Research Database (Denmark)

    Nielsen, Carsten; Sommer, Irene; Larsen, Karin

    2012-01-01

    learning are sparsely researched in the field of clinical education for nursing students. This paper reports on an action research study that promoted and investigated use of The Model of Practical Skill Performance as a learning tool during nursing students’ clinical placement. Clinical supervisors...... as during practice, performance and formative assessment of practical skills learning. It provided a common language about practical skills and enhanced the participants’ understanding of professionalism in practical nursing skill. In conclusion, the model helped to highlight the complexity in mastering...

  4. Analysis report for WIPP colloid model constraints and performance assessment parameters

    Energy Technology Data Exchange (ETDEWEB)

    Mariner, Paul E.; Sassani, David Carl

    2014-03-01

    An analysis of the Waste Isolation Pilot Plant (WIPP) colloid model constraints and parameter values was performed. The focus of this work was primarily on intrinsic colloids, mineral fragment colloids, and humic substance colloids, with a lesser focus on microbial colloids. Comments by the US Environmental Protection Agency (EPA) concerning intrinsic Th(IV) colloids and Mg-Cl-OH mineral fragment colloids were addressed in detail, assumptions and data used to constrain colloid model calculations were evaluated, and inconsistencies between data and model parameter values were identified. This work resulted in a list of specific conclusions regarding model integrity, model conservatism, and opportunities for improvement related to each of the four colloid types included in the WIPP performance assessment.

  5. Proposal for a Method for Business Model Performance Assessment: Toward an Experimentation Tool for Business Model Innovation

    Directory of Open Access Journals (Sweden)

    Antonio Batocchio

    2017-04-01

    Full Text Available The representation of business models has been recently widespread, especially in the pursuit of innovation. However, defining a company’s business model is sometimes limited to discussion and debates. This study observes the need for performance measurement so that business models can be data-driven. To meet this goal, the work proposed as a hypothesis the creation of a method that combines the practices of the Balanced Scorecard with a method of business models representation – the Business Model Canvas. Such a combination was based on study of conceptual adaptation, resulting in an application roadmap. A case study application was performed to check the functionality of the proposition, focusing on startup organizations. It was concluded that based on the performance assessment of the business model it is possible to propose the search for change through experimentation, a path that can lead to business model innovation.

  6. Modelling tools for assessing bioremediation performance and risk of chlorinated solvents in clay tills

    DEFF Research Database (Denmark)

    Chambon, Julie Claire Claudia

    of future remediation of chlorinated ethenes in low-permeability settings. In conclusion, this PhD-project has developed our understanding on transport and degradation processes of chlorinated solvents in clay tills, and this knowledge was used to develop modelling tools for assessment of risk...... are trapped in the low-permeability matrix and can then slowly back diffuse to the fracture network, forming a long-term secondary contamination source to the underlying aquifers. Because of the complex transport and degradation processes and the mass transfer limitations, risk assessment and remediation...... design are challenging. This thesis presents the development and application of analytical and numerical models to improve our understanding of transport and degradation processes in clay tills, which is crucial for assessing bioremediation performance and risk to groundwater. A set of modelling tools...

  7. Integrated performance assessment model for waste policy package behavior and radionuclide release

    International Nuclear Information System (INIS)

    Kossik, R.; Miller, I.; Cunnane, M.

    1992-01-01

    Golder Associates Inc. (GAI) has developed a probabilistic total system performance assessment and strategy evaluation model (RIP) which can be applied in an iterative manner to evaluate repository site suitability and guide site characterization. This paper describes one component of the RIP software, the waste package behavior and radionuclide release model. The waste package component model considers waste package failure by various modes, matrix alteration/dissolution, and radionuclide mass transfer. Model parameters can be described as functions of local environmental conditions. The waste package component model is coupled to component models for far-field radionuclide transport and disruptive events. The model has recently been applied to the proposed repository at Yucca Mountain

  8. Integrated performance assessment model for waste package behavior and radionuclide release

    International Nuclear Information System (INIS)

    Kossik, R.; Miller, I.; Cunnane, M.

    1992-01-01

    Golder Associates Inc. (GAI) has developed a probabilistic total system performance assessment and strategy evaluation model (RIP) which can be applied in an iterative manner to evaluate repository site suitability and guide site characterization. This paper describes one component of the RIP software, the waste package behavior and radionuclide release model. The waste package component model considers waste package failure by various modes, matrix alteration/dissolution, and radionuclide mass transfer. Model parameters can be described as functions of local environmental conditions. The waste package component model is coupled to component models for far-field radionuclide transport and disruptive events. The model has recently been applied to the proposed repository at Yucca Mountain

  9. Performance assessment of sealing systems. Conceptual and integrated modelling of plugs and seals

    International Nuclear Information System (INIS)

    Ruebel, Andre; Buhmann, Dieter; Kindlein, Jonathan; Lauke, Thomas

    2016-08-01

    The long-time isolation of radionuclides from the biosphere is the goal of the storage of radioactive waste in deep geological repositories. For repositories in rock salt, this goal is achieved on the one hand by the impermeable undisturbed part of the salt host rock formation and on the other hand by crushed salt, which is used to backfill the mine openings in the emplacement areas and galleries created during the construction of the repository. The crushed salt backfill is compacted over time and achieves a sufficiently high hydraulic resistance to avoid inflow of brines into the emplacement areas of the repository in the long-term. Plugs and seals must additionally provide their sealing function during the early post closure phase, until the compaction of the backfill is adequate and the permeability of the backfill is sufficiently low. To assess the future development of the waste repository, an adequate knowledge of the material behaviour is necessary and related mathematical models must be developed to be able to perform predictions on the long-term safety of the repository. An integrated performance assessment model was formulated that describes the long-term behaviour of a sealing built from salt concrete. The average permeability of the sealing changes with time after its emplacement from various processes of which two were regarded in a constitutive model: first, the healing of the EDZ in the host rock around the sealing, and second, the corrosion of the salt concrete material resulting from brine attack. Empirical parameter model functions were defined for both processes to reflect the actual behaviour. The mathematical model was implemented in the integrated performance assessment model LOPOS which is used by GRS as near-field model for repositories in salt. Deterministic and probabilistic calculations were performed with realistic parameters showing how the permeability of the sealing decreases during the first 2 000 years due to the healing of the EDZ

  10. Performance assessment of sealing systems. Conceptual and integrated modelling of plugs and seals

    Energy Technology Data Exchange (ETDEWEB)

    Ruebel, Andre; Buhmann, Dieter; Kindlein, Jonathan; Lauke, Thomas

    2016-08-15

    The long-time isolation of radionuclides from the biosphere is the goal of the storage of radioactive waste in deep geological repositories. For repositories in rock salt, this goal is achieved on the one hand by the impermeable undisturbed part of the salt host rock formation and on the other hand by crushed salt, which is used to backfill the mine openings in the emplacement areas and galleries created during the construction of the repository. The crushed salt backfill is compacted over time and achieves a sufficiently high hydraulic resistance to avoid inflow of brines into the emplacement areas of the repository in the long-term. Plugs and seals must additionally provide their sealing function during the early post closure phase, until the compaction of the backfill is adequate and the permeability of the backfill is sufficiently low. To assess the future development of the waste repository, an adequate knowledge of the material behaviour is necessary and related mathematical models must be developed to be able to perform predictions on the long-term safety of the repository. An integrated performance assessment model was formulated that describes the long-term behaviour of a sealing built from salt concrete. The average permeability of the sealing changes with time after its emplacement from various processes of which two were regarded in a constitutive model: first, the healing of the EDZ in the host rock around the sealing, and second, the corrosion of the salt concrete material resulting from brine attack. Empirical parameter model functions were defined for both processes to reflect the actual behaviour. The mathematical model was implemented in the integrated performance assessment model LOPOS which is used by GRS as near-field model for repositories in salt. Deterministic and probabilistic calculations were performed with realistic parameters showing how the permeability of the sealing decreases during the first 2 000 years due to the healing of the EDZ

  11. Development of an analytical model to assess fuel property effects on combustor performance

    Science.gov (United States)

    Sutton, R. D.; Troth, D. L.; Miles, G. A.; Riddlebaugh, S. M.

    1987-01-01

    A generalized first-order computer model has been developed in order to analytically evaluate the potential effect of alternative fuels' effects on gas turbine combustors. The model assesses the size, configuration, combustion reliability, and durability of the combustors required to meet performance and emission standards while operating on a broad range of fuels. Predictions predicated on combustor flow-field determinations by the model indicate that fuel chemistry, as defined by hydrogen content, exerts a significant influence on flame retardation, liner wall temperature, and smoke emission.

  12. Evolution in performance assessment modeling as a result of regulatory review

    Energy Technology Data Exchange (ETDEWEB)

    Rowat, J.H.; Dolinar, G.M.; Stephens, M.E. [AECL Chalk River Labs., Ontario (Canada)] [and others

    1995-12-31

    AECL is planning to build the IRUS (Intrusion Resistant Underground Structure) facility for near-surface disposal of LLRW. The PSAR (preliminary safety assessment report) was subject to an initial regulatory review during mid-1992. The regulatory authority provided comments on many aspects of the safety assessment documentation including a number of questions on specific PA (Performance Assessment) modelling assumptions. As a result of these comments as well as a separate detailed review of the IRUS disposal concept, changes were made to the conceptual and mathematical models. The original disposal concept included a non-sorbing vault backfill, with a strong reliance on the wasteform as a barrier. This concept was altered to decrease reliance on the wasteform by replacing the original backfill with a sand/clinoptilolite mix, which is a better sorber of metal cations. This change lead to changes in the PA models which in turn altered the safety case for the facility. This, and other changes that impacted performance assessment modelling are the subject of this paper.

  13. Constraining performance assessment models with tracer test results: a comparison between two conceptual models

    Science.gov (United States)

    McKenna, Sean A.; Selroos, Jan-Olof

    Tracer tests are conducted to ascertain solute transport parameters of a single rock feature over a 5-m transport pathway. Two different conceptualizations of double-porosity solute transport provide estimates of the tracer breakthrough curves. One of the conceptualizations (single-rate) employs a single effective diffusion coefficient in a matrix with infinite penetration depth. However, the tracer retention between different flow paths can vary as the ratio of flow-wetted surface to flow rate differs between the path lines. The other conceptualization (multirate) employs a continuous distribution of multiple diffusion rate coefficients in a matrix with variable, yet finite, capacity. Application of these two models with the parameters estimated on the tracer test breakthrough curves produces transport results that differ by orders of magnitude in peak concentration and time to peak concentration at the performance assessment (PA) time and length scales (100,000 years and 1,000 m). These differences are examined by calculating the time limits for the diffusive capacity to act as an infinite medium. These limits are compared across both conceptual models and also against characteristic times for diffusion at both the tracer test and PA scales. Additionally, the differences between the models are examined by re-estimating parameters for the multirate model from the traditional double-porosity model results at the PA scale. Results indicate that for each model the amount of the diffusive capacity that acts as an infinite medium over the specified time scale explains the differences between the model results and that tracer tests alone cannot provide reliable estimates of transport parameters for the PA scale. Results of Monte Carlo runs of the transport models with varying travel times and path lengths show consistent results between models and suggest that the variation in flow-wetted surface to flow rate along path lines is insignificant relative to variability in

  14. Tropospheric Ozone Assessment Report: Assessment of global-scale model performance for global and regional ozone distributions, variability, and trends

    Directory of Open Access Journals (Sweden)

    P. J. Young

    2018-01-01

    Full Text Available The goal of the Tropospheric Ozone Assessment Report (TOAR is to provide the research community with an up-to-date scientific assessment of tropospheric ozone, from the surface to the tropopause. While a suite of observations provides significant information on the spatial and temporal distribution of tropospheric ozone, observational gaps make it necessary to use global atmospheric chemistry models to synthesize our understanding of the processes and variables that control tropospheric ozone abundance and its variability. Models facilitate the interpretation of the observations and allow us to make projections of future tropospheric ozone and trace gas distributions for different anthropogenic or natural perturbations. This paper assesses the skill of current-generation global atmospheric chemistry models in simulating the observed present-day tropospheric ozone distribution, variability, and trends. Drawing upon the results of recent international multi-model intercomparisons and using a range of model evaluation techniques, we demonstrate that global chemistry models are broadly skillful in capturing the spatio-temporal variations of tropospheric ozone over the seasonal cycle, for extreme pollution episodes, and changes over interannual to decadal periods. However, models are consistently biased high in the northern hemisphere and biased low in the southern hemisphere, throughout the depth of the troposphere, and are unable to replicate particular metrics that define the longer term trends in tropospheric ozone as derived from some background sites. When the models compare unfavorably against observations, we discuss the potential causes of model biases and propose directions for future developments, including improved evaluations that may be able to better diagnose the root cause of the model-observation disparity. Overall, model results should be approached critically, including determining whether the model performance is acceptable for

  15. Assessing the Performance of Thermal Inertia and Hydrus Models to Estimate Surface Soil Water Content

    Directory of Open Access Journals (Sweden)

    Amro Negm

    2017-09-01

    Full Text Available The knowledge of soil water content (SWC dynamics in the upper soil layer is important for several hydrological processes. Due to the difficulty of assessing the spatial and temporal SWC dynamics in the field, some model-based approaches have been proposed during the last decade. The main objective of this work was to assess the performance of two approaches to estimate SWC in the upper soil layer under field conditions: the physically-based thermal inertia and the Hydrus model. Their validity was firstly assessed under controlled laboratory conditions. Thermal inertia was firstly validated in laboratory conditions using the transient line heat source (TLHS method. Then, it was applied in situ to analyze the dynamics of soil thermal properties under two extreme conditions of soil-water status (well-watered and air-dry, using proximity remote-sensed data. The model performance was assessed using sensor-based measurements of soil water content acquired through frequency (FDR and time domain reflectometry (TDR. During the laboratory experiment, the Root Mean Square Error (RMSE was 0.02 m3 m−3 for the Hydrus model and 0.05 m3 m−3 for the TLHS model approach. On the other hand, during the in situ experiment, the temporal variability of SWCs simulated by the Hydrus model and the corresponding values measured by the TDR method evidenced good agreement (RMSE ranging between 0.01 and 0.005 m3 m−3. Similarly, the average of the SWCs derived from the thermal diffusion model was fairly close to those estimated by Hydrus (spatially averaged RMSE ranging between 0.03 and 0.02 m3 m−3.

  16. Performance Assessment Modeling and Sensitivity Analyses of Generic Disposal System Concepts.

    Energy Technology Data Exchange (ETDEWEB)

    Sevougian, S. David; Freeze, Geoffrey A.; Gardner, William Payton; Hammond, Glenn Edward; Mariner, Paul

    2014-09-01

    directly, rather than through simplified abstractions. It also a llows for complex representations of the source term, e.g., the explicit representation of many individual waste packages (i.e., meter - scale detail of an entire waste emplacement drift). This report fulfills the Generic Disposal System Analysis Work Packa ge Level 3 Milestone - Performance Assessment Modeling and Sensitivity Analyses of Generic Disposal System Concepts (M 3 FT - 1 4 SN08080 3 2 ).

  17. Performance assessment model development and analysis of radionuclide transport in the unsaturated zone, Yucca Mountain, Nevada

    Science.gov (United States)

    Robinson, Bruce A.; Li, Chunhong; Ho, Clifford K.

    2003-05-01

    This paper describes the development and use of a particle-tracking model to perform radionuclide-transport simulations in the unsaturated zone at Yucca Mountain, Nevada. The goal of the effort was to produce a computational model that can be coupled to the project's calibrated 3D site-scale flow model so that the results of that effort could be incorporated directly into the Total System Performance Assessment (TSPA) analyses. The transport model simulates multiple species (typically 20 or more) with complex time-varying and spatially varying releases from the potential repository. Water-table rise, climate-change scenarios, and decay chains are additional features of the model. A cell-based particle-tracking method was employed that includes a dual-permeability formulation, advection, longitudinal dispersion, matrix diffusion, and colloid-facilitated transport. This paper examines the transport behavior of several key radionuclides through the unsaturated zone using the calibrated 3D unsaturated flow fields. Computational results illustrate the relative importance of fracture flow, matrix diffusion, and lateral diversion on the distribution of travel times from the simulated repository to the water table for various climatic conditions. Results also indicate rapid transport through fractures for a portion of the released mass. Further refinement of the model will address several issues, including conservatism in the transport model, the assignment of parameters in the flow and transport models, and the underlying assumptions used to support the conceptual models of flow and transport in the unsaturated zone at Yucca Mountain.

  18. The development of performance-based practical assessment model at civil engineering workshop in state polytechnic

    Science.gov (United States)

    Kristinayanti, W. S.; Mas Pertiwi, I. G. A. I.; Evin Yudhi, S.; Lokantara, W. D.

    2018-01-01

    Assessment is an important element in education that shall oversees students’ competence not only in terms of cognitive aspect, but alsothe students’ psychomotorin a comprehensive way. Civil Engineering Department at Bali State Polytechnic,as a vocational education institution, emphasizes on not only the theoretical foundation of the study, but also the application throughpracticum in workshop-based learning. We are aware of a need for performance-based assessment for these students, which would be essential for the student’s all-round performance in their studies.We try to develop a performance-based practicum assessment model that is needed to assess student’s ability in workshop-based learning. This research was conducted in three stages, 1) learning needs analysis, 2) instruments development, and 3) testing of instruments. The study uses rubrics set-up to test students’ competence in the workshop and test the validity. We obtained 34-point valid statement out of 35, and resulted in value of Cronbach’s alpha equal to 0.977. In expert test we obtained a value of CVI = 0.75 which means that the drafted assessment is empirically valid within thetrial group.

  19. Context for performance assessment

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1997-01-01

    In developing its recommendations on performance assessment for disposal of low-level radioactive waste, Scientific committee 87-3 of the National Council on Radiation Protection and Measurements (NCRP) has considered a number of topics that provide a context for the development of suitable approaches to performance assessment. This paper summarizes the Committee' discussions on these topics, including (1) the definition of low-level waste and its sources and properties, as they affect the variety of wastes that must be considered, (2) fundamental objectives and principles of radioactive waste disposal and their application to low-level waste, (3) current performance objectives for low-level waste disposal in the US, with particular emphasis on such unresolved issues of importance to performance assessment as the time frame for compliance, requirements for protection of groundwater and surface water, inclusion of doses from radon, demonstrating compliance with fixed performance objectives using highly uncertain model projections, and application of the principle that releases to the environment should be maintained as low as reasonably achievable (ALARA), (4) the role of active and passive institutional controls over disposal sites, (5) the role of the inadvertent human intruder in low-level waste disposal, (6) model validation and confidence in model outcomes, and (7) the concept of reasonable assurance of compliance

  20. Modeling and performance assessment in QinetiQ of EO and IR airborne reconnaissance systems

    Science.gov (United States)

    Williams, John W.; Potter, Gary E.

    2002-11-01

    QinetiQ are the technical authority responsible for specifying the performance requirements for the procurement of airborne reconnaissance systems, on behalf of the UK MoD. They are also responsible for acceptance of delivered systems, overseeing and verifying the installed system performance as predicted and then assessed by the contractor. Measures of functional capability are central to these activities. The conduct of these activities utilises the broad technical insight and wide range of analysis tools and models available within QinetiQ. This paper focuses on the tools, methods and models that are applicable to systems based on EO and IR sensors. The tools, methods and models are described, and representative output for systems that QinetiQ has been responsible for is presented. The principle capability applicable to EO and IR airborne reconnaissance systems is the STAR (Simulation Tools for Airborne Reconnaissance) suite of models. STAR generates predictions of performance measures such as GRD (Ground Resolved Distance) and GIQE (General Image Quality) NIIRS (National Imagery Interpretation Rating Scales). It also generates images representing sensor output, using the scene generation software CAMEO-SIM and the imaging sensor model EMERALD. The simulated image 'quality' is fully correlated with the predicted non-imaging performance measures. STAR also generates image and table data that is compliant with STANAG 7023, which may be used to test ground station functionality.

  1. Source-term model for the SYVAC3-NSURE performance assessment code

    International Nuclear Information System (INIS)

    Rowat, J.H.; Rattan, D.S.; Dolinar, G.M.

    1996-11-01

    Radionuclide contaminants in wastes emplaced in disposal facilities will not remain in those facilities indefinitely. Engineered barriers will eventually degrade, allowing radioactivity to escape from the vault. The radionuclide release rate from a low-level radioactive waste (LLRW) disposal facility, the source term, is a key component in the performance assessment of the disposal system. This report describes the source-term model that has been implemented in Ver. 1.03 of the SYVAC3-NSURE (Systems Variability Analysis Code generation 3-Near Surface Repository) code. NSURE is a performance assessment code that evaluates the impact of near-surface disposal of LLRW through the groundwater pathway. The source-term model described here was developed for the Intrusion Resistant Underground Structure (IRUS) disposal facility, which is a vault that is to be located in the unsaturated overburden at AECL's Chalk River Laboratories. The processes included in the vault model are roof and waste package performance, and diffusion, advection and sorption of radionuclides in the vault backfill. The model presented here was developed for the IRUS vault; however, it is applicable to other near-surface disposal facilities. (author). 40 refs., 6 figs

  2. Uncertainty and Sensitivity of Alternative Rn-222 Flux Density Models Used in Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Greg J. Shott, Vefa Yucel, Lloyd Desotell

    2007-06-01

    Performance assessments for the Area 5 Radioactive Waste Management Site on the Nevada Test Site have used three different mathematical models to estimate Rn-222 flux density. This study describes the performance, uncertainty, and sensitivity of the three models which include the U.S. Nuclear Regulatory Commission Regulatory Guide 3.64 analytical method and two numerical methods. The uncertainty of each model was determined by Monte Carlo simulation using Latin hypercube sampling. The global sensitivity was investigated using Morris one-at-time screening method, sample-based correlation and regression methods, the variance-based extended Fourier amplitude sensitivity test, and Sobol's sensitivity indices. The models were found to produce similar estimates of the mean and median flux density, but to have different uncertainties and sensitivities. When the Rn-222 effective diffusion coefficient was estimated using five different published predictive models, the radon flux density models were found to be most sensitive to the effective diffusion coefficient model selected, the emanation coefficient, and the radionuclide inventory. Using a site-specific measured effective diffusion coefficient significantly reduced the output uncertainty. When a site-specific effective-diffusion coefficient was used, the models were most sensitive to the emanation coefficient and the radionuclide inventory.

  3. Uncertainty and Sensitivity of Alternative Rn-222 Flux Density Models Used in Performance Assessment

    International Nuclear Information System (INIS)

    Greg J. Shott, Vefa Yucel, Lloyd Desotell Non-Nstec Authors: G. Pyles and Jon Carilli

    2007-01-01

    Performance assessments for the Area 5 Radioactive Waste Management Site on the Nevada Test Site have used three different mathematical models to estimate Rn-222 flux density. This study describes the performance, uncertainty, and sensitivity of the three models which include the U.S. Nuclear Regulatory Commission Regulatory Guide 3.64 analytical method and two numerical methods. The uncertainty of each model was determined by Monte Carlo simulation using Latin hypercube sampling. The global sensitivity was investigated using Morris one-at-time screening method, sample-based correlation and regression methods, the variance-based extended Fourier amplitude sensitivity test, and Sobol's sensitivity indices. The models were found to produce similar estimates of the mean and median flux density, but to have different uncertainties and sensitivities. When the Rn-222 effective diffusion coefficient was estimated using five different published predictive models, the radon flux density models were found to be most sensitive to the effective diffusion coefficient model selected, the emanation coefficient, and the radionuclide inventory. Using a site-specific measured effective diffusion coefficient significantly reduced the output uncertainty. When a site-specific effective-diffusion coefficient was used, the models were most sensitive to the emanation coefficient and the radionuclide inventory

  4. Development of a unit cell model for interim performance assessment of vitrified low level waste disposal

    International Nuclear Information System (INIS)

    Kline, N.W.

    1995-09-01

    The unit cell modeling approach has been developed and used in analysis of some design options for a vitrified low level waste disposal facility. The unit cell modeling approach is likely to be useful in interim performance assessment for the facility. The present unit cell model will probably need to be refitted in terms of some model parameters for the latter purpose. Two present disposal facility concepts differ in the length of a capillary barrier proposed to limit effective recharge through the top of the facility. Results of the study summarized herein suggest design of a capillary barrier which can reduce a recharge rate of 0.1 cm/yr by one or two orders of magnitude seems feasible for both concepts. A benchmark comparison of the unit cell model against a full facility model shows comparable predictive accuracy in less than one percent of the computer time. Results suggest that model parameters include capillary barrier performance, inter-canister spacing, rate of moisture withdrawal due to glass corrosion, contaminant inventory, and the well interceptor factor. It is also important that variations of waste form hydraulic parameters suggest that transport through the waste form is dominated by diffusion

  5. Modeling and Quantification of Team Performance in Human Reliability Analysis for Probabilistic Risk Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey C. JOe; Ronald L. Boring

    2014-06-01

    Probabilistic Risk Assessment (PRA) and Human Reliability Assessment (HRA) are important technical contributors to the United States (U.S.) Nuclear Regulatory Commission’s (NRC) risk-informed and performance based approach to regulating U.S. commercial nuclear activities. Furthermore, all currently operating commercial NPPs in the U.S. are required by federal regulation to be staffed with crews of operators. Yet, aspects of team performance are underspecified in most HRA methods that are widely used in the nuclear industry. There are a variety of "emergent" team cognition and teamwork errors (e.g., communication errors) that are 1) distinct from individual human errors, and 2) important to understand from a PRA perspective. The lack of robust models or quantification of team performance is an issue that affects the accuracy and validity of HRA methods and models, leading to significant uncertainty in estimating HEPs. This paper describes research that has the objective to model and quantify team dynamics and teamwork within NPP control room crews for risk informed applications, thereby improving the technical basis of HRA, which improves the risk-informed approach the NRC uses to regulate the U.S. commercial nuclear industry.

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

    Science.gov (United States)

    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

  7. Use of simplified models in the performance assessment of a high-level waste repository system in Japan

    International Nuclear Information System (INIS)

    Pensado, Osvaldo; Mohanty, Sitakanta; Kanno, Takeshi; Tochigi, Yoshikatsu

    2005-01-01

    This paper explores simplifications to the H12 performance assessment model to enhance performance in Monte Carlo analyses. It is shown that similar reference case results to those of the H12 model can be derived by describing the buffer material surrounding a waste package as a planar body. Other possible simplifications to the performance assessment model in areas related to the stratification of the host rock transmissivity domain and solubility constraints in the buffer material are explored. (author)

  8. Modelling and assessment of dependent performance shaping factors through Analytic Network Process

    International Nuclear Information System (INIS)

    De Ambroggi, Massimiliano; Trucco, Paolo

    2011-01-01

    Despite continuous progresses in research and applications, one of the major weaknesses of current HRA methods dwells in their limited capability of modelling the mutual influences between performance shaping factors (PSFs). Indeed at least two types of dependencies between PSFs can be defined: (i) dependency between the states of the PSFs; (ii) dependency between the influences (impacts) of the PSFs on the human performance. This paper introduces a method, based on Analytic Network Process (ANP), for the quantification of the latter, where the overall contribution of each PSF (weight) to the human error probability (HEP) is eventually returned. The core of the method is the modelling process, articulated into two steps: firstly, a qualitative network of dependencies between PSFs is identified, then, the importance of each PSF is quantitatively assessed using ANP. The model allows to distinguish two components of the PSF influence: direct influence that is the influence that the considered PSF is able to express by itself, notwithstanding the presence of other PSFs and indirect influence that is the incremental influence of the considered PSF through its influence on other PSFs. A case study in Air Traffic Control is presented where the proposed approach is integrated into the cognitive simulator PROCOS. The results demonstrated a significant modification of the influence of PSFs over the operator performance when dependencies are taken into account, underlining the importance of considering not only the possible correlation between the states of PSFs but also their mutual dependency in affecting human performance in complex systems.

  9. The different parts played by hydrodynamic modelling in performance assessment of low level radwaste repository

    International Nuclear Information System (INIS)

    Dewiere, L.; Lavie, J.; Andre, P.; Andre Jehan, R.; Peaudecerf, P.

    1993-01-01

    According to the relevant Fundamental Safety Rule, the ''Centre de Stockage de l'Aube'' (CSA) has been built on a simple aquifer system perfectly isolated from underlying aquifers and with well defined outflow locations. In addition, each repository cell must be out of reach of the highest free surface water level. The site hydrogeological study has been conducted through a very large site characterization work. Early hydrogeological site modelling and characterization work made it possible to gather hydrogeological field data into a coherent conceptual model expressed through a simple computer tool. This first stage made up of qualification and development phases was followed by applications on the aquifer behaviour and on the highest water level evaluation. Hydrogeological modelling has played a key role in the French disposal concept from site selection to the final performance assessment. (author). 6 refs., 8 figs

  10. Waste package performance assessment

    International Nuclear Information System (INIS)

    Lester, D.H.

    1981-01-01

    This paper describes work undertaken to assess the life-expectancy and post-failure nuclide release behavior of high-level and waste packages in a geologic repository. The work involved integrating models of individual phenomena (such as heat transfer, corrosion, package deformation, and nuclide transport) and using existing data to make estimates of post-emplacement behavior of waste packages. A package performance assessment code was developed to predict time to package failure in a flooded repository and subsequent transport of nuclides out of the leaking package. The model has been used to evaluate preliminary package designs. The results indicate, that within the limitation of model assumptions and data base, packages lasting a few hundreds of years could be developed. Very long lived packages may be possible but more comprehensive data are needed to confirm this

  11. Unit cell modeling in support of interim performance assessment for low level tank waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Kline, N.W., Westinghouse Hanford

    1996-08-01

    A unit cell model is used to simulate the base analysis case and related sensitivity cases for the interim performance assessment of low level tank waste disposal. Simulation case results are summarized in terms of fractional contaminant release rates to the vadose zone and to the water table at the unconfined aquifer. Results suggest that the crushed glass water conditioning layer at the top of the facility and the chemical retardation pad at the bottom of the facility can be important components of the facility. Results also suggest that the release rates to the water table are dominated by the release rate from the waste form.

  12. Rodent model for assessing the long term safety and performance of peripheral nerve recording electrodes

    Science.gov (United States)

    Vasudevan, Srikanth; Patel, Kunal; Welle, Cristin

    2017-02-01

    Objective. In the US alone, there are approximately 185 000 cases of limb amputation annually, which can reduce the quality of life for those individuals. Current prosthesis technology could be improved by access to signals from the nervous system for intuitive prosthesis control. After amputation, residual peripheral nerves continue to convey motor signals and electrical stimulation of these nerves can elicit sensory percepts. However, current technology for extracting information directly from peripheral nerves has limited chronic reliability, and novel approaches must be vetted to ensure safe long-term use. The present study aims to optimize methods to establish a test platform using rodent model to assess the long term safety and performance of electrode interfaces implanted in the peripheral nerves. Approach. Floating Microelectrode Arrays (FMA, Microprobes for Life Sciences) were implanted into the rodent sciatic nerve. Weekly in vivo recordings and impedance measurements were performed in animals to assess performance and physical integrity of electrodes. Motor (walking track analysis) and sensory (Von Frey) function tests were used to assess change in nerve function due to the implant. Following the terminal recording session, the nerve was explanted and the health of axons, myelin and surrounding tissues were assessed using immunohistochemistry (IHC). The explanted electrodes were visualized under high magnification using scanning electrode microscopy (SEM) to observe any physical damage. Main results. Recordings of axonal action potentials demonstrated notable session-to-session variability. Impedance of the electrodes increased upon implantation and displayed relative stability until electrode failure. Initial deficits in motor function recovered by 2 weeks, while sensory deficits persisted through 6 weeks of assessment. The primary cause of failure was identified as lead wire breakage in all of animals. IHC indicated myelinated and unmyelinated axons

  13. SITE-94. Adaptation of mechanistic sorption models for performance assessment calculations

    International Nuclear Information System (INIS)

    Arthur, R.C.

    1996-10-01

    Sorption is considered in most predictive models of radionuclide transport in geologic systems. Most models simulate the effects of sorption in terms of empirical parameters, which however can be criticized because the data are only strictly valid under the experimental conditions at which they were measured. An alternative is to adopt a more mechanistic modeling framework based on recent advances in understanding the electrical properties of oxide mineral-water interfaces. It has recently been proposed that these 'surface-complexation' models may be directly applicable to natural systems. A possible approach for adapting mechanistic sorption models for use in performance assessments, using this 'surface-film' concept, is described in this report. Surface-acidity parameters in the Generalized Two-Layer surface complexation model are combined with surface-complexation constants for Np(V) sorption ob hydrous ferric oxide to derive an analytical model enabling direct calculation of corresponding intrinsic distribution coefficients as a function of pH, and Ca 2+ , Cl - , and HCO 3 - concentrations. The surface film concept is then used to calculate whole-rock distribution coefficients for Np(V) sorption by altered granitic rocks coexisting with a hypothetical, oxidized Aespoe groundwater. The calculated results suggest that the distribution coefficients for Np adsorption on these rocks could range from 10 to 100 ml/g. Independent estimates of K d for Np sorption in similar systems, based on an extensive review of experimental data, are consistent, though slightly conservative, with respect to the calculated values. 31 refs

  14. Investigation of modern methods of probalistic sensitivity analysis of final repository performance assessment models (MOSEL)

    International Nuclear Information System (INIS)

    Spiessl, Sabine; Becker, Dirk-Alexander

    2017-06-01

    Sensitivity analysis is a mathematical means for analysing the sensitivities of a computational model to variations of its input parameters. Thus, it is a tool for managing parameter uncertainties. It is often performed probabilistically as global sensitivity analysis, running the model a large number of times with different parameter value combinations. Going along with the increase of computer capabilities, global sensitivity analysis has been a field of mathematical research for some decades. In the field of final repository modelling, probabilistic analysis is regarded a key element of a modern safety case. An appropriate uncertainty and sensitivity analysis can help identify parameters that need further dedicated research to reduce the overall uncertainty, generally leads to better system understanding and can thus contribute to building confidence in the models. The purpose of the project described here was to systematically investigate different numerical and graphical techniques of sensitivity analysis with typical repository models, which produce a distinctly right-skewed and tailed output distribution and can exhibit a highly nonlinear, non-monotonic or even non-continuous behaviour. For the investigations presented here, three test models were defined that describe generic, but typical repository systems. A number of numerical and graphical sensitivity analysis methods were selected for investigation and, in part, modified or adapted. Different sampling methods were applied to produce various parameter samples of different sizes and many individual runs with the test models were performed. The results were evaluated with the different methods of sensitivity analysis. On this basis the methods were compared and assessed. This report gives an overview of the background and the applied methods. The results obtained for three typical test models are presented and explained; conclusions in view of practical applications are drawn. At the end, a recommendation

  15. Investigation of modern methods of probalistic sensitivity analysis of final repository performance assessment models (MOSEL)

    Energy Technology Data Exchange (ETDEWEB)

    Spiessl, Sabine; Becker, Dirk-Alexander

    2017-06-15

    Sensitivity analysis is a mathematical means for analysing the sensitivities of a computational model to variations of its input parameters. Thus, it is a tool for managing parameter uncertainties. It is often performed probabilistically as global sensitivity analysis, running the model a large number of times with different parameter value combinations. Going along with the increase of computer capabilities, global sensitivity analysis has been a field of mathematical research for some decades. In the field of final repository modelling, probabilistic analysis is regarded a key element of a modern safety case. An appropriate uncertainty and sensitivity analysis can help identify parameters that need further dedicated research to reduce the overall uncertainty, generally leads to better system understanding and can thus contribute to building confidence in the models. The purpose of the project described here was to systematically investigate different numerical and graphical techniques of sensitivity analysis with typical repository models, which produce a distinctly right-skewed and tailed output distribution and can exhibit a highly nonlinear, non-monotonic or even non-continuous behaviour. For the investigations presented here, three test models were defined that describe generic, but typical repository systems. A number of numerical and graphical sensitivity analysis methods were selected for investigation and, in part, modified or adapted. Different sampling methods were applied to produce various parameter samples of different sizes and many individual runs with the test models were performed. The results were evaluated with the different methods of sensitivity analysis. On this basis the methods were compared and assessed. This report gives an overview of the background and the applied methods. The results obtained for three typical test models are presented and explained; conclusions in view of practical applications are drawn. At the end, a recommendation

  16. The Integration and Abstraction of EBS Models in Yucca Mountain Performance Assessment

    International Nuclear Information System (INIS)

    S.D. Sevougian; V. Jain; A.V. Luik

    2006-01-01

    The safety strategy for geological disposal of radioactive waste at Yucca Mountain relies on a multi-barrier system to contain the waste and isolate it from the biosphere. The multi-barrier system consists of the natural barrier provided by the geological setting and the engineered barrier system (EBS). In the case of Yucca Mountain (YM) the geologic setting is the unsaturated-zone host rock, consisting of about 600 meters of layered ash-flow volcanic tuffs above the water table, and the saturated zone beneath the water table. Both the unsaturated and saturated rocks are part of a closed hydrologic basin in a desert surface environment. The waste is to be buried about halfway between the desert surface and the water table. The primary engineered barriers at YM consist of metal components that are highly durable in an oxidizing environment. The two primary components of the engineered barrier system are highly corrosion-resistant metal waste packages, made from a nickel-chromium-molybdenum alloy, Alloy 22, and titanium drip shields that protect the waste packages from corrosive dripping water and falling rocks. Design and performance assessment of the EBS requires models that describe how the EBS and near field behave under anticipated repository-relevant conditions. These models must describe coupled hydrologic, thermal, chemical, and mechanical (THCM) processes that drive radionuclide transport in a highly fractured host rock, consisting of a relatively permeable network of conductive fractures in a setting of highly impermeable tuff rock matrix. An integrated performance assessment of the EBS must include a quantification of the uncertainties that arise from (1) incomplete understanding of processes and (2) from lack of data representative of the large spatial scales and long time scales relevant to radioactive waste disposal (e.g., long-term metal corrosion rates and heterogeneities in rock properties over the large 5 km 2 emplacement area of the repository). A

  17. Texas' performance assessment work

    International Nuclear Information System (INIS)

    Charbeneau, R.J.; Hertel, N.E.; Pollard, C.G.

    1990-01-01

    The Texas Low-Level Radioactive Waste Disposal Authority is completing two years of detailed on-site suitability studies of a potential low-level radioactive waste disposal site in Hudspeth County, Texas. The data from these studies have been used to estimate site specific parameters needed to do a performance assessment of the site. The radiological impacts of the site have been analyzed as required for a license application. The approach adopted for the performance assessment was to use simplified and yet conservative assumptions with regard to releases, radionuclide transport, and dose calculations. The methodologies employed in the performance assessment are reviewed in the paper. Rather than rely on a single computer code, a modular approach to the performance assessment was selected. The HELP code was used to calculate the infiltration rate through the trench covers and the amount of leachate released from this arid site. Individual pathway analyses used spreadsheet calculations. These calculations were compared with those from other computer models including CRRIS, INGDOS, PATHRAE, and MICROSHIELD copyright, and found to yield conservative estimates of the effective whole body dose. The greatest difficulty in performing the radiological assessment of the site was the selection of reasonable source terms for release into the environment. A surface water pathway is unreasonable for the site. Though also unlikely, the groundwater pathway with exposure through a site boundary well was found to yield the largest calculated dose. The more likely pathway including transport of leachate from the facility through the unsaturated zone and returning to the ground surface yields small doses. All calculated doses associated with normal releases of radioactivity are below the regulatory limits

  18. Performance Assessment of the VSC Using Two Model Predictive Control Schemes

    DEFF Research Database (Denmark)

    Al hasheem, Mohamed; Abdelhakim, Ahmed; Dragicevic, Tomislav

    2018-01-01

    Finite control set model predictive control (FCS-MPC) methods in different power electronics application are gaining high attention due to their simplicity and fast dynamics. This paper introduces an experimental assessment of the two-level three-phase voltage source converter (2L-VSC) using two...... FCS-MPC algorithms. In order to perform such comparative evaluation, the 2L-VSC efficiency and total harmonics distortion voltage (THDv) have been measured where considering a linear load and non-linear load. The new algorithm gives better results than the conventional algorithm in terms of the THD...... and 2L-VSC efficiency. The results also demonstrate the performance of the system using carrier based pulse width modulation (CB-PWM). These findings have been validated for both linear and non-linear loads through experimental verification on 4 kW 2L-VSC prototype. It can be concluded that a comparable...

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

    Science.gov (United States)

    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

  20. An updated fracture-flow model for total-system performance assessment of Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Gauthier, J.H. [Spectra Research Inst., Albuquerque, NM (United States)

    1994-07-01

    Improvements have been made to the fracture-flow model being used in the total-system performance assessment of a potential high-level radioactive waste repository at Yucca Mountain, Nevada. The ``weeps model`` now includes (1) weeps of varied sizes, (2) flow-pattern fluctuations caused by climate change, and (3) flow-pattern perturbations caused by repository heat generation. Comparison with the original weeps model indicates that allowing weeps of varied sizes substantially reduces the number of weeps and the number of containers contacted by weeps. However, flow-pattern perturbations caused by either climate change or repository heat generation greatly increases the number of containers contacted by weeps. In preliminary total-system calculations, using a phenomenological container-failure and radionuclide-release model, the weeps model predicts that radionuclide releases from a high-level radioactive waste repository at Yucca Mountain will be below the EPA standard specified in 40 CFR 191, but that the maximum radiation dose to an individual could be significant. Specific data from the site are required to determine the validity of the weep-flow mechanism and to better determine the parameters to which the dose calculation is sensitive.

  1. An updated fracture-flow model for total-system performance assessment of Yucca Mountain

    International Nuclear Information System (INIS)

    Gauthier, J.H.

    1994-01-01

    Improvements have been made to the fracture-flow model being used in the total-system performance assessment of a potential high-level radioactive waste repository at Yucca Mountain, Nevada. The ''weeps model'' now includes (1) weeps of varied sizes, (2) flow-pattern fluctuations caused by climate change, and (3) flow-pattern perturbations caused by repository heat generation. Comparison with the original weeps model indicates that allowing weeps of varied sizes substantially reduces the number of weeps and the number of containers contacted by weeps. However, flow-pattern perturbations caused by either climate change or repository heat generation greatly increases the number of containers contacted by weeps. In preliminary total-system calculations, using a phenomenological container-failure and radionuclide-release model, the weeps model predicts that radionuclide releases from a high-level radioactive waste repository at Yucca Mountain will be below the EPA standard specified in 40 CFR 191, but that the maximum radiation dose to an individual could be significant. Specific data from the site are required to determine the validity of the weep-flow mechanism and to better determine the parameters to which the dose calculation is sensitive

  2. The Development and Application of a Value-Driven Aircraft Maintenance Operations Performance Assessment Model combined with Real Options Analysis

    NARCIS (Netherlands)

    Goossens, H.G.; Beelaerts van Blokland, W.W.A.; Curran, R.

    2011-01-01

    This research paper presents the results from the development of an Aircraft Maintenance Operations Performance Assessment Model (AMOPAM). The AMOPAM is able to assess the differences in performance in between two different states or scenarios of aircraft maintenance operations and is able to

  3. An updated fracture-flow model for total-system performance assessment of Yucca Mountain

    International Nuclear Information System (INIS)

    Gauthier, J.H.

    1994-01-01

    Improvements have been made to the fracture-flow model being used in the total-system performance assessment of a potential high-level radioactive waste repository at Yucca Mountain, Nevada. The open-quotes weeps modelclose quotes now includes (1) weeps of varied sizes, (2) flow-pattern fluctuations caused by climate change, and (3) flow-pattern perturbations caused by repository heat generation. Comparison with the original weeps model indicates that allowing weeps of varied sizes substantially reduces the number of weeps and the number of containers contacted by weeps. However, flow-pattern perturbations caused by either climate change or repository heat generation greatly increases the number of containers contacted by weeps. In preliminary total-system calculations, using a phenomenological container-failure and radionuclide-release model, the weeps model predicts that radionuclide releases from a high-level radioactive waste repository at Yucca Mountain will be below the EPA standard specified in 40 CFR 191, but that the maximum radiation dose to an individual could be significant. Specific data from the site are required to determine the validity of the weep-flow mechanism and to better determine the parameters to which the dose calculation is sensitive

  4. CRYSTAL: A model of a fractured rock geosphere for performance assessment within SKI Project-90

    International Nuclear Information System (INIS)

    Worgan, K.; Robinson, P.

    1992-02-01

    A one-dimensional model of a fractured rock geosphere (CRYSTAL) has been developed, which forms part of the toolkit for the Swedish Nuclear Power Inspectorates reference repository performance assessment programme (Project-90). CRYSTAL predicts the transport of arbitrary-length decay chains by advection, diffusion and surface sorption in the fractures and sideways diffusion into the rock matrix. The model equations are solved in Laplace transform space, and inverted numerically to the time domain. This approach avoids time-stepping and consequently is numerically very efficient. The interface of CRYSTAL with the time-series output from a near-field model, such as CALIBRE, is achieved using the method of convolution. The response of the geosphere to delta-function inputs from each nuclide is combined with the time series outputs from the near-field, to obtain the nuclide flux emerging from the far-field. The method is sufficiently flexible to allow for any general time-series input from CALIBRE or any other near-field model. Although CRYSTAL was developed to handle one-dimensional transport in a fractured rock, the equations solved are sufficiently general for it to be used in other applications, e.g. in a porous system. (au)

  5. A Management Maturity Model (MMM for project-based organisational performance assessment

    Directory of Open Access Journals (Sweden)

    Craig Langston

    2016-12-01

    Full Text Available Common sense suggests that organisations are more likely to deliver successful projects if they have systems in place that reflect a mature project environment based on a culture of continuous improvement. This paper develops and discusses a Management Maturity Model (MMM to assess the maturity of project management organisations through a customisable, systematic, strategic and practical methodology inspired from the seminal work of Darwin, Deming, Drucker and Daniel. The model presented is relevant to organisations, such as construction and engineering companies, that prefer to use the Project Management Body of Knowledge (PMBOK™ Guide published by the Project Management Institute (PMI, but without the disadvantages of excessive time and cost commitments and a ‘one size fits all’ approach linked to rigid increments of maturity. It offers a game-changing advance in the application of project-based organisational performance assessment compared to existing market solutions that are unnecessarily complex. The feasibility of MMM is field-tested using a medium-sized data centre infrastructure firm in Tehran.

  6. Lightning Protection Performance Assessment of Transmission Line Based on ATP model Automatic Generation

    Directory of Open Access Journals (Sweden)

    Luo Hanwu

    2016-01-01

    Full Text Available This paper presents a novel method to solve the initial lightning breakdown current by combing ATP and MATLAB simulation software effectively, with the aims to evaluate the lightning protection performance of transmission line. Firstly, the executable ATP simulation model is generated automatically according to the required information such as power source parameters, tower parameters, overhead line parameters, grounding resistance and lightning current parameters, etc. through an interface program coded by MATLAB. Then, the data are extracted from the generated LIS files which can be obtained by executing the ATP simulation model, the occurrence of transmission lie breakdown can be determined by the relative data in LIS file. The lightning current amplitude should be reduced when the breakdown occurs, and vice the verse. Thus the initial lightning breakdown current of a transmission line with given parameters can be determined accurately by continuously changing the lightning current amplitude, which is realized by a loop computing algorithm that is coded by MATLAB software. The method proposed in this paper can generate the ATP simulation program automatically, and facilitates the lightning protection performance assessment of transmission line.

  7. Effect of alternative conceptual models in a preliminary performance assessment for the waste isolation pilot plant

    International Nuclear Information System (INIS)

    Helton, J.C.; Bean, J.E.; Berglund, J.W.; Beyeler, W.; Garner, J.W.; Iuzzolino, H.J.; Marietta, M.G.; Rudeen, D.K.; Schreiber, J.D.; Swift, P.N.; Tierney, M.S.; Vaughn, P.

    1995-01-01

    The most appropriate conceptual model for performance assessment (PA) at the waste isolation pilot plant (WIPP) is believed to include gas generation resulting from corrosion and microbial action in the repository, and a dual-porosity (matrix and fracture porosity) representation for the solute transport in the Culebra dolomite member of the Rustler formation. Under these assumptions, complementary cummulative distribution functions (CCDFs) which summarize the radionuclide releases to the accessible environment, resulting from both cutting removal and groundwater transport, fall substantially below the release limits promulgated by the US Environmental Protection Agency (EPA), with the releases being dominated by cuttings removal. To provide additional views, the following alternative conceptual models were considered as part of a preliminary PA for the WIPP: no gas generation in the repository and a dual-porosity transport model in the Culebra; gas generation in the repository and a single-porosity (fracture porosity) transport model in the Culebra; no gas generation in the repository and a single-porosity transport model in the Culebra; gas generation in the repository and a dual-porosity transport model in the Culebra, without chemical retardation; gas generation in the repository, chemical retardation in the Culebra, and extremes of climatic variation. These variations relate to groundwater transport, so do not affect the releases resulting from cuttings removal. Several of these variations substantially increase the importance of releases resulting from groundwater transport relative to releases resulting from cuttings removal. However, the total amount of releases generally remained small, with the CCDFs which summarize the releases to the accessible environment falling below the EPA release limits

  8. Performance Degradation Assessment Method for Cracked Rotor Based on Multi-observation Hidden Markov Model

    Directory of Open Access Journals (Sweden)

    Lijun ZHANG

    2014-09-01

    Full Text Available Reliability of rotating machinery has a significant relation with personal safety and economic efficiency. With the development of science and technology, the improvement of performance degradation of machinery becomes increasingly higher. Research of traditional reliability theory depends on failure data. Some lifetime data result in little or even no failure. For mechanical equipment, degradation data may contain useful information about machinery reliability. Service condition of rotating machinery suffers from a long period of deterioration time until functional failure occurs. However, normal or failure status of rotating machinery is simply defined by traditional fault diagnosis methods. A machinery performance degradation assessment method for the cracked rotor based on multi-observation Hidden Markov Model is proposed for rotating machinery in run-up and shutdown processes. The proposed method can reflect the change of the performance of rotating machinery effectively. Finally, dynamics simulation data of the cracked rotor with gradually decreasing stiffness is used to validate the feasibility of the proposed method.

  9. A conceptual performance assessment model of the dissolved actinide source term for the WIPP

    International Nuclear Information System (INIS)

    Weiner, R.F.; Stockman, C.T.; Wang, Y.; Novak, C.F.

    1996-01-01

    This paper presents a performance assessment model of dissolved actinide concentrations for the Waste Isolation Pilot Plant (WIPP). The model assesses the concentration of each actinide oxidation state and combines these concentrations with an oxidation state distribution. The chemical behavior of actinides in the same oxidation state is presumed to be very similar for almost all situations, but exceptions arising from experimental evidence are accommodated. The code BRAGFLO calculates the gas pressure, brine mass, gas volume, and mass of remaining Fe and cellulosics for each time step and computational cell. The total CO 2 in the repository and dissolved Ca(OH) 2 is estimated. Lookup tables are constructed for pmH and f(CO 2 ) as a function of brine type and volume, moles of CO 2 , and Ca(OH) 2 . Amounts of five soluble complexants are considered. A model based on the formulation of Harvie et al. produces tables of solubilities for each actinide oxidation state as a function of pmH, f(CO 2 ), brine composition, and complexant. Experimental data yield lookup tables of fractions of Th, U, Np, Pu, and Am in each oxidation state as a function of f(CO 2 ) and complexant. The tables are then used to provide a concentration of a particular actinide at particular values of pmH and f(CO 2 ). Under steady-state conditions, the oxidation state of each actinide that is most stable in the particular chemical environment controls the concentration of that actinide in solution. In the absence of steady-state conditions, the oxidation state distribution of interest is that of the dissolved actinide, and the oxidation states may be treated as if they were separate compounds

  10. Preliminary performance assessment for the Waste Isolation Pilot Plant, December 1992. Volume 3, Model parameters: Sandia WIPP Project

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-29

    This volume documents model parameters chosen as of July 1992 that were used by the Performance Assessment Department of Sandia National Laboratories in its 1992 preliminary performance assessment of the Waste Isolation Pilot Plant (WIPP). Ranges and distributions for about 300 modeling parameters in the current secondary data base are presented in tables for the geologic and engineered barriers, global materials (e.g., fluid properties), and agents that act upon the WIPP disposal system such as climate variability and human-intrusion boreholes. The 49 parameters sampled in the 1992 Preliminary Performance Assessment are given special emphasis with tables and graphics that provide insight and sources of data for each parameter.

  11. Matrix Diffusion for Performance Assessment - Experimental Evidence, Modelling Assumptions and Open Issues

    International Nuclear Information System (INIS)

    Jakob, A.

    2004-07-01

    In this report a comprehensive overview on the matrix diffusion of solutes in fractured crystalline rocks is presented. Some examples from observations in crystalline bedrock are used to illustrate that matrix diffusion indeed acts on various length scales. Fickian diffusion is discussed in detail followed by some considerations on rock porosity. Due to the fact that the dual-porosity medium model is a very common and versatile method for describing solute transport in fractured porous media, the transport equations and the fundamental assumptions, approximations and simplifications are discussed in detail. There is a variety of geometrical aspects, processes and events which could influence matrix diffusion. The most important of these, such as, e.g., the effect of the flow-wetted fracture surface, channelling and the limited extent of the porous rock for matrix diffusion etc., are addressed. In a further section open issues and unresolved problems related to matrix diffusion are mentioned. Since matrix diffusion is one of the key retarding processes in geosphere transport of dissolved radionuclide species, matrix diffusion was consequently taken into account in past performance assessments of radioactive waste repositories in crystalline host rocks. Some issues regarding matrix diffusion are site-specific while others are independent of the specific situation of a planned repository for radioactive wastes. Eight different performance assessments from Finland, Sweden and Switzerland were considered with the aim of finding out how matrix diffusion was addressed, and whether a consistent picture emerges regarding the varying methodology of the different radioactive waste organisations. In the final section of the report some conclusions are drawn and an outlook is given. An extensive bibliography provides the reader with the key papers and reports related to matrix diffusion. (author)

  12. The process of performance assessment

    International Nuclear Information System (INIS)

    King, C.M.; Halford, D.K.

    1986-01-01

    An introductory review of the subject of ''Performance Assessment'' will be presented. Emphasis will be placed on the process of performance assessment from the standpoint of defining the process. Performance assessment, from evolving experience at DOE sites, has short-term and long-term subprograms, the components of which will be discussed. The role of mathematical modeling in performance assessment will be addressed including the pros and cons of current approaches. Finally, the ''system/site/technology'' issues as the focal point of this symposium will be reviewed

  13. NRC performance assessment program

    International Nuclear Information System (INIS)

    Coplan, S.M.

    1986-01-01

    The U.S. Nuclear Regulatory Commission's (NRC) performance assessment program includes the development of guidance to the U.S. Department of Energy (DOE) on preparation of a license application and on conducting the studies to support a license application. The nature of the licensing requirements of 10 CFR Part 60 create a need for performance assessments by the DOE. The NRC and DOE staffs each have specific roles in assuring the adequacy of those assessments. Performance allocation is an approach for determining what testing and analysis will be needed during site characterization to assure that an adequate data base is available to support the necessary performance assessments. From the standpoint of establishing is implementable methodology, the most challenging performance assessment needed for licensing is the one that will be used to determine compliance with the U.S. Environmental Protection Agency's (EPA) containment requirement

  14. A Model for Predicting Student Performance on High-Stakes Assessment

    Science.gov (United States)

    Dammann, Matthew Walter

    2010-01-01

    This research study examined the use of student achievement on reading and math state assessments to predict success on the science state assessment. Multiple regression analysis was utilized to test the prediction for all students in grades 5 and 8 in a mid-Atlantic state. The prediction model developed from the analysis explored the combined…

  15. The Relationship between Students' Performance on Conventional Standardized Mathematics Assessments and Complex Mathematical Modeling Problems

    Science.gov (United States)

    Kartal, Ozgul; Dunya, Beyza Aksu; Diefes-Dux, Heidi A.; Zawojewski, Judith S.

    2016-01-01

    Critical to many science, technology, engineering, and mathematics (STEM) career paths is mathematical modeling--specifically, the creation and adaptation of mathematical models to solve problems in complex settings. Conventional standardized measures of mathematics achievement are not structured to directly assess this type of mathematical…

  16. Performance Assessment of a Low-Level Radioactive Waste Disposal Site using GoldSim Integrated Systems Model

    Science.gov (United States)

    Merrell, G.; Singh, A.; Tauxe, J.; Perona, R.; Dornsife, W.; grisak, G. E.; Holt, R. M.

    2011-12-01

    Texas Commission on Environmental Quality has approved licenses for four landfills at the Waste Control Specialists (WCS) site located in Andrews County, West Texas. The site includes a hazardous waste landfill and three landfills for radioactive waste. An updated performance assessment is necessary prior to acceptance of waste at the landfills. The updated performance assessment a) provides for more realistic and flexible dose modeling capabilities, b) addresses all plausible release and accident scenarios as they relate to the performance objectives, c) includes impact of climate and hydrologic scenarios that may impact long-term performance of the landfill, d) addresses impact of cover naturalization and degradation on the landfill, and e) incorporates uncertainty and sensitivity analysis for critical parameters. For the updated performance assessment, WCS has developed an integrated systems level performance assessment model using the GoldSim platform. GoldSim serves as a model for integrating all of the major components of a performance assessment, which include the radionuclide source term, facility design, environmental transport pathways, exposure scenarios, and radiological doses. Unlike many computer models that are based on first principles, GoldSim is a systems level model that can be used to integrate and abstract more complex sub-models into one system. This can then be used to assess the results into a unified model of the disposal system and environment. In this particular application, the GoldSim model consists of a) hydrogeologic model that simulates flow and transport through the Dockum geologic unit that underlies all of the waste facilities, b) waste cells that represent the containment unit and simulate degradation of waste forms, radionuclide leaching, and partitioning into the liquid and vapor phase within the waste unit, c) a cover system model that simulates upward diffusive transport from the underground repository to the atmosphere. In

  17. The Five-Factor Model Personality Assessment for Improved Student Design Team Performance

    Science.gov (United States)

    Ogot, Madara; Okudan, Gul E.

    2006-01-01

    Researchers have long noted the correlation of various personality traits and team performance. Studies relating aggregate team personality traits to team performance are scattered in the literature and may not always be relevant to engineering design teams. This paper synthesizes the results from applicable Five-Factor Model (FFM)-based…

  18. The assessment of the performance of covariance-based structural equation modeling and partial least square path modeling

    Science.gov (United States)

    Aimran, Ahmad Nazim; Ahmad, Sabri; Afthanorhan, Asyraf; Awang, Zainudin

    2017-05-01

    Structural equation modeling (SEM) is the second generation statistical analysis technique developed for analyzing the inter-relationships among multiple variables in a model. Previous studies have shown that there seemed to be at least an implicit agreement about the factors that should drive the choice between covariance-based structural equation modeling (CB-SEM) and partial least square path modeling (PLS-PM). PLS-PM appears to be the preferred method by previous scholars because of its less stringent assumption and the need to avoid the perceived difficulties in CB-SEM. Along with this issue has been the increasing debate among researchers on the use of CB-SEM and PLS-PM in studies. The present study intends to assess the performance of CB-SEM and PLS-PM as a confirmatory study in which the findings will contribute to the body of knowledge of SEM. Maximum likelihood (ML) was chosen as the estimator for CB-SEM and was expected to be more powerful than PLS-PM. Based on the balanced experimental design, the multivariate normal data with specified population parameter and sample sizes were generated using Pro-Active Monte Carlo simulation, and the data were analyzed using AMOS for CB-SEM and SmartPLS for PLS-PM. Comparative Bias Index (CBI), construct relationship, average variance extracted (AVE), composite reliability (CR), and Fornell-Larcker criterion were used to study the consequence of each estimator. The findings conclude that CB-SEM performed notably better than PLS-PM in estimation for large sample size (100 and above), particularly in terms of estimations accuracy and consistency.

  19. Assessing the performance of prediction models: a framework for traditional and novel measures

    DEFF Research Database (Denmark)

    Steyerberg, Ewout W; Vickers, Andrew J; Cook, Nancy R

    2010-01-01

    (NRI), and integrated discrimination improvement (IDI). Moreover, decision-analytic measures have been proposed, including decision curves to plot the net benefit achieved by making decisions based on model predictions.We aimed to define the role of these relatively novel approaches in the evaluation...... be important for a prediction model. Decision-analytic measures should be reported if the predictive model is to be used for clinical decisions. Other measures of performance may be warranted in specific applications, such as reclassification metrics to gain insight into the value of adding a novel predictor...... of the performance of prediction models. For illustration, we present a case study of predicting the presence of residual tumor versus benign tissue in patients with testicular cancer (n = 544 for model development, n = 273 for external validation).We suggest that reporting discrimination and calibration will always...

  20. Development of a model for assessing the impact of information assurance functionality on secure messaging system performance

    Science.gov (United States)

    Belur, Sheela V.; Gloster, Jonathan

    2007-04-01

    An analytical performance model for a generic secure messaging system is formulated as a multi-class queuing network. The model includes assessment of the impact of security features such as secret key encryption/ decryption, signature generation/verification, and certificate validation, on overall performance. Findings of sensitivity analysis with respect to message rate, WAN transmission link, SSL encryption, message size, and distance between servers is also presented. Finally, the description of how the model can be adopted for making performance based architectural design options is outlined.

  1. Enhanced science-stakeholder communication to improve ecosystem model performances for climate change impact assessments

    DEFF Research Database (Denmark)

    Jonsson, Anna Maria; Anderbrant, Olle; Holmer, Jennie

    2015-01-01

    In recent years, climate impact assessments of relevance to the agricultural and forestry sectors have received considerable attention. Current ecosystem models commonly capture the effect of a warmer climate on biomass production, but they rarely sufficiently capture potential losses caused...... modelling with policy and strategies for sustainable management. In this paper we give a brief overview of different ecosystem modelling methods, discuss how to include ecological and management aspects, and highlight the importance of science–stakeholder communication. By this, we hope to stimulate...

  2. Assessing the performance of regional landslide early warning models: the EDuMaP method

    Science.gov (United States)

    Calvello, M.; Piciullo, L.

    2016-01-01

    A schematic of the components of regional early warning systems for rainfall-induced landslides is herein proposed, based on a clear distinction between warning models and warning systems. According to this framework an early warning system comprises a warning model as well as a monitoring and warning strategy, a communication strategy and an emergency plan. The paper proposes the evaluation of regional landslide warning models by means of an original approach, called the "event, duration matrix, performance" (EDuMaP) method, comprising three successive steps: identification and analysis of the events, i.e., landslide events and warning events derived from available landslides and warnings databases; definition and computation of a duration matrix, whose elements report the time associated with the occurrence of landslide events in relation to the occurrence of warning events, in their respective classes; evaluation of the early warning model performance by means of performance criteria and indicators applied to the duration matrix. During the first step the analyst identifies and classifies the landslide and warning events, according to their spatial and temporal characteristics, by means of a number of model parameters. In the second step, the analyst computes a time-based duration matrix with a number of rows and columns equal to the number of classes defined for the warning and landslide events, respectively. In the third step, the analyst computes a series of model performance indicators derived from a set of performance criteria, which need to be defined by considering, once again, the features of the warning model. The applicability, potentialities and limitations of the EDuMaP method are tested and discussed using real landslides and warning data from the municipal early warning system operating in Rio de Janeiro (Brazil).

  3. Experimental Validation of a Domestic Stratified Hot Water Tank Model in Modelica for Annual Performance Assessment

    DEFF Research Database (Denmark)

    Carmo, Carolina; Dumont, Olivier; Nielsen, Mads Pagh

    2015-01-01

    The use of stratified hot water tanks in solar energy systems - including ORC systems - as well as heat pump systems is paramount for a better performance of these systems. However, the availability of effective and reliable models to predict the annual performance of stratified hot water tanks...... coupled with energy system solutions is limited. In this poster, a discretized model of a stratified tank developed in Modelica is presented. The physical phenoma to be considered are the thermal transfers by conduction and convection – stratification, heat loss to ambient, charging and discharging...

  4. Comparative assessment of students' performance and perceptions on objective structured practical models in undergraduate pathology teaching.

    Science.gov (United States)

    Htwe, Than Than; Ismail, Sabaridah Binti; Low, Gary Kim Kuan

    2014-09-01

    Assessment is an important factor that drives student learning, as students tend to mainly focus on the material to be assessed. The current practice in teaching pathology extensively applies objective-structured practical examination for the assessment of students. As students will have to deal with real patients during clinical years, it is preferred that students learn and practise via potted specimens and slides instead of picture plates. This study aimed to assess the preferred assesment method of pathology practical exercises. This was a cross-sectional survey carried out in two consecutive batches of Phase 2 medical students. Student competency was assessed using both the traditional (TD) (i.e. use of potted specimens and slides) and picture plate (PP) methods. To compare the two assessment methods, we compared the mean scores obtained by the students and examined student perception of the two methods. The mean scores obtained via the PP method were significantly higher than those obtained via the TD method for almost all the components tested. We found that students performed significantly better (p visuals, thus aiding understanding, than the TD method. The findings of this study are valuable in identifying and improving our current teaching and assessment methods of medical students, in line with advancements in information technology.

  5. Comparative assessment of students’ performance and perceptions on objective structured practical models in undergraduate pathology teaching

    Science.gov (United States)

    Htwe, Than Than; Ismail, Sabaridah Binti; Low, Gary Kim Kuan

    2014-01-01

    INTRODUCTION Assessment is an important factor that drives student learning, as students tend to mainly focus on the material to be assessed. The current practice in teaching pathology extensively applies objective-structured practical examination for the assessment of students. As students will have to deal with real patients during clinical years, it is preferred that students learn and practise via potted specimens and slides instead of picture plates. This study aimed to assess the preferred assesment method of pathology practical exercises. METHODS This was a cross-sectional survey carried out in two consecutive batches of Phase 2 medical students. Student competency was assessed using both the traditional (TD) (i.e. use of potted specimens and slides) and picture plate (PP) methods. To compare the two assessment methods, we compared the mean scores obtained by the students and examined student perception of the two methods. RESULTS The mean scores obtained via the PP method were significantly higher than those obtained via the TD method for almost all the components tested. CONCLUSION We found that students performed significantly better (p visuals, thus aiding understanding, than the TD method. The findings of this study are valuable in identifying and improving our current teaching and assessment methods of medical students, in line with advancements in information technology. PMID:25273936

  6. Multi-crew Model Analytic Assessment of Landing Performance and Decision-making Demands

    Science.gov (United States)

    Milgram, P.; Vanderwijngaart, R.; Veerbeek, H.; Bleeker, O. F.

    1984-01-01

    Some of the relative merits of the PROCRU approach to modelling multi-crew flight deck activity during approach to landing are discussed. On the basis of two realistic flight scenarios, the ability of the model to simulate different vectored approaches is demonstrated. A secondary exemplary analysis of a nominal and an accelerated final approach is performed, illustrating the potential of the expected net gain (ENGP) functions as a measure of decision-making load.

  7. Modelling of Radionuclide Transport by Groundwater Motion in Fractured Bedrock for Performance Assessment Purposes

    International Nuclear Information System (INIS)

    Woerman, Anders; Shulan Xu

    2003-10-01

    Field data of physical properties in heterogeneous crystalline bedrock, like fracture zones, fracture connectivity, matrix porosity and fracture aperture, is associated with uncertainty that can have a significant impact on the analysis of solute transport in fractured rock. The purpose of this study is to develop a performance assessment (PA) model for analyses of radionuclide transport in the geosphere, in which the model takes into account both the effect of heterogeneities of hydrological and geochemical rock properties. By using a travel time description of radionuclide transport in rock fractures, we decompose the transport problem into a one-dimensional mass transfer problem along a distribution of transport pathways and a multi-dimensional flow problem in the fractured bedrock. The hydraulic/flow problem is solved based on a statistical discrete-fracture model (DFM) that represents the network of fractures around the repository and in the surrounding geosphere. A Monte Carlo technique reflects the fact that the representation of the fracture network is uncertain. If the flow residence time PDF exhibits multiple peaks or in another way shows a more erratic hydraulic response on the network scale, the three-dimensional travel time approach is superior to a one-dimensional transport modeling. Examples taken from SITE 94, a study performed by the Swedish Nuclear Power Inspectorate, showed that such cases can be found in safety assessments based on site data. The solute transport is formulated based on partial, differential equations and perturbations (random spatial variability in bedrock properties) are introduced in the coefficients to reflect an uncertainty of the exact appearance of the bedrock associated with the discrete data collection. The combined approach for water flow and solute transport, thereby, recognises an uncertainty in our knowledge in both 1) bedrock properties along individual pathways and 2) the distribution of pathways. Solutions to the

  8. Assess and Predict Automatic Generation Control Performances for Thermal Power Generation Units Based on Modeling Techniques

    Science.gov (United States)

    Zhao, Yan; Yang, Zijiang; Gao, Song; Liu, Jinbiao

    2018-02-01

    Automatic generation control(AGC) is a key technology to maintain real time power generation and load balance, and to ensure the quality of power supply. Power grids require each power generation unit to have a satisfactory AGC performance, being specified in two detailed rules. The two rules provide a set of indices to measure the AGC performance of power generation unit. However, the commonly-used method to calculate these indices is based on particular data samples from AGC responses and will lead to incorrect results in practice. This paper proposes a new method to estimate the AGC performance indices via system identification techniques. In addition, a nonlinear regression model between performance indices and load command is built in order to predict the AGC performance indices. The effectiveness of the proposed method is validated through industrial case studies.

  9. Modeling The Inhalation Exposure Pathway In Performance Assessment Of Geologic Radioactive Waste Repository At Yucca Mountain

    International Nuclear Information System (INIS)

    M.A. Wasiolek

    2006-01-01

    Inhalation exposure pathway modeling has recently been investigated as one of the tasks of the BIOPROTA Project (BIOPROTA 2005). BIOPROTA was set up to address the key uncertainties in long term assessments of contaminant releases into the environment arising from radioactive waste disposal. Participants of this international Project include national authorities and agencies, both regulators and operators, with responsibility for achieving safe and acceptable radioactive waste management. The objective of the inhalation task was to investigate the calculation of doses arising from inhalation of particles suspended from soils within which long-lived radionuclides, particularly alpha emitters, had accumulated. It was recognized that site-specific conditions influence the choice of conceptual model and input parameter values. Therefore, one of the goals of the task was to identify the circumstances in which different processes included in specific inhalation exposure pathway models were important. This paper discusses evaluation of processes and modeling assumptions specific to the proposed repository at Yucca Mountain as compared to the typical approaches and other models developed for different assessments and project specific contexts. Inhalation of suspended particulates that originate from contaminated soil is an important exposure pathway, particularly for exposure to actinides such as uranium, neptunium and plutonium. Radionuclide accumulation in surface soil arises from irrigation of soil with contaminated water over many years. The level of radionuclide concentration in surface soil depends on the assumed duration of irrigation. Irrigation duration is one of the parameters used on biosphere models and it depends on a specific assessment context. It is one of the parameters addressed in this paper from the point of view of assessment context for the proposed repository at Yucca Mountain. The preferred model for the assessment of inhalation exposure uses

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  11. A contribution of cognitive decision models to clinical assessment: decomposing performance on the Bechara gambling task.

    Science.gov (United States)

    Busemeyer, Jerome R; Stout, Julie C

    2002-09-01

    The Bechara simulated gambling task is a popular method of examining decision-making deficits exhibited by people with brain damage, psychopathology, antisocial personality, or drug abuse problems. However, performance on this task is confounded by complex interdependencies between cognitive, motivational, and response processes, making it difficult to sort out and identify the specific processes responsible for the observed behavioral deficits. The authors compare 3 competing cognitive decision models of the Bechara task in terms of their ability to explain the performance deficits observed in Huntington's disease patients as compared with healthy populations and people with Parkinson's disease. The parameters of the best fitting model are used to decompose the observed performance deficit of the Huntington patients into cognitive, motivational, and response sources.

  12. Assessing the Performance of Clostridium perfringens Cooling Models for Cooked, Uncured Meat and Poultry Products.

    Science.gov (United States)

    Mohr, T B; Juneja, V K; Thippareddi, H H; Schaffner, D W; Bronstein, P A; Silverman, M; Cook, L V

    2015-08-01

    Heat-resistant spores of Clostridium perfringens may germinate and multiply in cooked meat and poultry products when the rate and extent of cooling does not occur in a timely manner. Therefore, six cooling models (PMP 7.0 broth model; PMIP uncured beef, chicken, and pork models; Smith-Schaffner version 3; and UK IFR ComBase Perfringens Predictor) were evaluated for relative performance in predicting growth of C. perfringens under dynamic temperature conditions encountered during cooling of cooked, uncured meat and poultry products. The predicted growth responses from the models were extensively compared with those observed in food. Data from 188 time-temperature cooling profiles (176 for single-rate exponential cooling and 12 for dual-rate exponential cooling) were collected from 17 independent sources (16 peer-reviewed publications and one report) for model evaluation. Data were obtained for a variety of cooked products, including meat and poultry slurries, ground meat and poultry products with and without added ingredients (e.g., potato starch, sodium triphosphate, and potassium tetrapyrophosphate), and processed products such as ham and roast beef. Performance of the models was evaluated using three sets of criteria, and accuracy was defined within a 1- to 2-log range. The percentages of accurate, fail-safe, or fail-dangerous predictions for each cooling model differed depending on which criterion was used to evaluate the data set. Nevertheless, the combined percentages of accurate and fail-safe predictions based on the three performance criteria were 34.66 to 42.61% for the PMP 7.0 beef broth model, 100% for the PMIP cooling models for uncured beef, uncured pork and uncured chicken, 80.11 to 93.18% for the Smith-Schaffner cooling model, and 74.43 to 85.23% for the UK IFR ComBase Perfringens Predictor model during single-rate exponential chilling. Except for the PMP 7.0 broth model, the other five cooling models (PMIP, Smith-Schaffner, and UK IFR ComBase) are

  13. Modeling and controller performance assessment for a switched reluctance motor drive based on setpoint relay.

    Science.gov (United States)

    dos Reis, L L N; Coelho, A A R; Almeida, O M; Campos, J C T

    2009-04-01

    This paper considers the implementation of a current control method for switched reluctance motors (SRMs) and presents a novel approach to the accurate on-line modeling of an SRM drive. A simple autotuning technique for the SRM drives using a PWM controller is considered. Furthermore, conventional PI control and Internal Model Control (IMC) are considered to validate this method and present corresponding robust control analysis for the process. The control structures are comparatively analyzed using standard robustness measures for stability and performance. The proposed PWM controller is simulated and a hardware prototype is then implemented using digital signal processor control to evaluate the method using a 12/8, three-phase SRM. The experimental results of the SRM drive model validates the performance of the current loop.

  14. A Novel Approach for Assessing the Performance of Sustainable Urbanization Based on Structural Equation Modeling: A China Case Study

    Directory of Open Access Journals (Sweden)

    Liudan Jiao

    2016-09-01

    Full Text Available The rapid urbanization process has brought problems to China, such as traffic congestion, air pollution, water pollution and resources scarcity. Sustainable urbanization is commonly appreciated as an effective way to promote the sustainable development. The proper understanding of the sustainable urbanization performance is critical to provide governments with support in making urban development strategies and policies for guiding the sustainable development. This paper utilizes the method of Structural equation modeling (SEM to establish an assessment model for measuring sustainable urbanization performance. Four unobserved endogenous variables, economic variable, social variable, environment variable and resource variable, and 21 observed endogenous variables comprise the SEM model. A case study of the 31 provinces in China demonstrates the validity of the SEM model and the analysis results indicated that the assessment model could help make more effective policies and strategies for improving urban sustainability by recognizing the statue of sustainable urbanization.

  15. [Model oriented assessment of literacy performance in children with cochlear implants].

    Science.gov (United States)

    Fiori, A; Reichmuth, K; Matulat, P; Schmidt, C M; Dinnesen, A G

    2006-07-01

    Although most hearing-impaired children lag behind normally hearing children in literacy acquisition, this aspect has hardly been addressed in the evaluation of language acquisition after cochlear implantation. The present study investigated written language abilities in 8 school-age children with cochlear implants. Neurolinguistic dual-route-models of written language processing indicate that literacy acquisition leads to the establishment of two distinct reading and writing strategies: a lexical one for the quick processing of known words and a sublexical one for decoding unfamiliar words or nonwords letter by letter. 8 school-aged children were investigated, a very heterogeneous group concerning age of onset of hearing impairment, educational placement, and competences in sign language. However, this range is typical of the group of CI-children. The aim was to investigate if children with cochlear implants are able to establish both strategies or if they need to find a differential and individual access to written language. Performance within the Salzburger Lese-Rechtschreib-Test was evaluated. Individual performance of each subject was analysed. Performance varied substantially ranging from only rudimentary spoken and written language abilities in two children to age-equivalent performance in three of them. Severe qualitative differences in written language processing were shown in the remaining three subjects. Suggestions for remediation were made and a re-test was carried out after 12 months. Their individual profiles of performance are described in detail. The present study stresses the importance of a thorough investigation of written language performance in the evaluation of language acquisition after cochlear implantation. The results draw a very heterogeneous picture of performance. Model-oriented testing and analysis of performance prove to be sensible in at least a subpopulation of children with cochlear implants. Based on a better understanding of

  16. Assessment of Efficiency and Performance in Tsunami Numerical Modeling with GPU

    Science.gov (United States)

    Yalciner, Bora; Zaytsev, Andrey

    2017-04-01

    Non-linear shallow water equations (NSWE) are used to solve the propagation and coastal amplification of long waves and tsunamis. Leap Frog scheme of finite difference technique is one of the satisfactory numerical methods which is widely used in these problems. Tsunami numerical models are necessary for not only academic but also operational purposes which need faster and accurate solutions. Recent developments in information technology provide considerably faster numerical solutions in this respect and are becoming one of the crucial requirements. Tsunami numerical code NAMI DANCE uses finite difference numerical method to solve linear and non-linear forms of shallow water equations for long wave problems, specifically for tsunamis. In this study, the new code is structured for Graphical Processing Unit (GPU) using CUDA API. The new code is applied to different (analytical, experimental and field) benchmark problems of tsunamis for tests. One of those applications is 2011 Great East Japan tsunami which was instrumentally recorded on various types of gauges including tide and wave gauges and offshore GPS buoys cabled Ocean Bottom Pressure (OBP) gauges and DART buoys. The accuracy of the results are compared with the measurements and fairly well agreements are obtained. The efficiency and performance of the code is also compared with the version using multi-core Central Processing Unit (CPU). Dependence of simulation speed with GPU on linear or non-linear solutions is also investigated. One of the results is that the simulation speed is increased up to 75 times comparing to the process time in the computer using single 4/8 thread multi-core CPU. The results are presented with comparisons and discussions. Furthermore how multi-dimensional finite difference problems fits towards GPU architecture is also discussed. The research leading to this study has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement No

  17. Preliminary Review of Models, Assumptions, and Key Data used in Performance Assessments and Composite Analysis at the Idaho National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Arthur S. Rood; Swen O. Magnuson

    2009-07-01

    This document is in response to a request by Ming Zhu, DOE-EM to provide a preliminary review of existing models and data used in completed or soon to be completed Performance Assessments and Composite Analyses (PA/CA) documents, to identify codes, methodologies, main assumptions, and key data sets used.

  18. Micro gas turbine configurations with carbon capture – Performance assessment using a validated thermodynamic model

    International Nuclear Information System (INIS)

    Mansouri Majoumerd, Mohammad; Nikpey Somehsaraei, Homam; Assadi, Mohsen; Breuhaus, Peter

    2014-01-01

    The expected increase in distributed power generation, especially in Europe, and the necessity for a reduction in greenhouse gas emissions requires an evaluation of carbon capture application at small-scale combined heat and power plants. In this regard, a micro gas turbine (MGT), a Turbec T100, has been selected for further investigation as a baseline. A thermodynamic model validated against data obtained from a test rig has been extended to enable modeling of a CO 2 capture unit. In addition, two innovative cycles, an exhaust gas recirculation (EGR) cycle and a humid air turbine (HAT) cycle, have been investigated using the selected micro gas turbine model with a focus on improved carbon capture efficiency. The thermodynamic performance indicators of all cycles, namely, the baseline MGT cycle, the EGR cycle, and the HAT cycle, all with capture unit, are presented. The results show a considerable improvement in cycle efficiency for the HAT cycle (25.8%), compared to the baseline MGT (23.0%) and EGR (22.5%) cycles. However, the surge margin is reduced markedly for the HAT cycle. It is shown that the effect of EGR on the operation of the micro gas turbine is marginal. The effects of varying ambient air temperature on the performance of all cycles as well as the effect of different recirculation percentages on the performance of the EGR cycle have also been investigated. The results confirm that the performance in the EGR cycle is less sensitive to the change in ambient temperature, compared to the other cycles. The marginal effect of various recirculation percentages on the performance of the EGR cycle is also shown in this paper. - Highlights: • A validated MGT model based on a Turbec T100 is presented. • CO 2 capture unit is integrated to the baseline MGT model. • Micro gas turbine using EGR and HAT cycles with CO 2 capture is also investigated. • Effects of ambient temperature variation on the cycles' performance are presented. • A considerable

  19. Performance Assessment of Turbulence Models for the Prediction of the Reactor Internal Flow in the Scale-down APR+

    International Nuclear Information System (INIS)

    Lee, Gonghee; Bang, Youngseok; Woo, Swengwoong; Kim, Dohyeong; Kang, Minku

    2013-01-01

    The types of errors in CFD simulation can be divided into the two main categories: numerical errors and model errors. Turbulence model is one of the important sources for model errors. In this study, in order to assess the prediction performance of Reynolds-averaged Navier-Stokes (RANS)-based two equations turbulence models for the analysis of flow distribution inside a 1/5 scale-down APR+, the simulation was conducted with the commercial CFD software, ANSYS CFX V. 14. In this study, in order to assess the prediction performance of turbulence models for the analysis of flow distribution inside a 1/5 scale-down APR+, the simulation was conducted with the commercial CFD software, ANSYS CFX V. 14. Both standard k-ε model and SST model predicted the similar flow pattern inside reactor. Therefore it was concluded that the prediction performance of both turbulence models was nearly same. Complex thermal-hydraulic characteristics exist inside reactor because the reactor internals consist of fuel assembly, control rod assembly, and the internal structures. Either flow distribution test for the scale-down reactor model or computational fluid dynamics (CFD) simulation have been conducted to understand these complex thermal-hydraulic features inside reactor

  20. Ranking of Performance Assessment Measures at Tehran Hotel by Combining DEMATEL, ANP, and SERVQUAL Models under Fuzzy Condition

    Directory of Open Access Journals (Sweden)

    Mehrdad Kargari

    2018-01-01

    Full Text Available An effective hybrid model has been proposed by combining ANP, SERVQUAL, and DEMATEL techniques. This model aims to meet different purposes of the hotels and diverse needs of customers at different stages, that is, reservation, reception, accommodation, catering, and check-out. High quality services are ensured when customer expectations have been provided at the expectation level of the customers or beyond that. SERVQUAL model is used to assess the performance of the organizations in terms of five dimensions: responsiveness, empathy, reliability, assurance, and tangibles. Super matrix calculations and pair comparisons required in ANP model have been carried out using DEMATEL model in order to measure the influence of performance assessment measures on each other. In this paper, SERVQUAL model parameters have been considered as the expectations of the hotel clients. Then these customer expectations have been analyzed using DEMATEL model and finally have been ranked using ANP model. Parameters of SERVQUAL model are comprised of verbal and vague criteria in terms of the responses provided by the organizations and customers. This has led to fuzzy conditions in this research. The hybrid model provided better results compared with each individual model, in terms of meeting customer satisfaction and the organization’s objectives.

  1. Simplified predictive models for CO2 sequestration performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Srikanta [Battelle Memorial Inst., Columbus, OH (United States); Ganesh, Priya [Battelle Memorial Inst., Columbus, OH (United States); Schuetter, Jared [Battelle Memorial Inst., Columbus, OH (United States); He, Jincong [Battelle Memorial Inst., Columbus, OH (United States); Jin, Zhaoyang [Battelle Memorial Inst., Columbus, OH (United States); Durlofsky, Louis J. [Battelle Memorial Inst., Columbus, OH (United States)

    2015-09-30

    CO2 sequestration in deep saline formations is increasingly being considered as a viable strategy for the mitigation of greenhouse gas emissions from anthropogenic sources. In this context, detailed numerical simulation based models are routinely used to understand key processes and parameters affecting pressure propagation and buoyant plume migration following CO2 injection into the subsurface. As these models are data and computation intensive, the development of computationally-efficient alternatives to conventional numerical simulators has become an active area of research. Such simplified models can be valuable assets during preliminary CO2 injection project screening, serve as a key element of probabilistic system assessment modeling tools, and assist regulators in quickly evaluating geological storage projects. We present three strategies for the development and validation of simplified modeling approaches for CO2 sequestration in deep saline formations: (1) simplified physics-based modeling, (2) statisticallearning based modeling, and (3) reduced-order method based modeling. In the first category, a set of full-physics compositional simulations is used to develop correlations for dimensionless injectivity as a function of the slope of the CO2 fractional-flow curve, variance of layer permeability values, and the nature of vertical permeability arrangement. The same variables, along with a modified gravity number, can be used to develop a correlation for the total storage efficiency within the CO2 plume footprint. Furthermore, the dimensionless average pressure buildup after the onset of boundary effects can be correlated to dimensionless time, CO2 plume footprint, and storativity contrast between the reservoir and caprock. In the second category, statistical “proxy models” are developed using the simulation domain described previously with two approaches: (a) classical Box-Behnken experimental design with a quadratic response surface, and (b) maximin

  2. ASSESSMENT OF CONDENSATION HEAT TRANSFER MODEL TO EVALUATE PERFORMANCE OF THE PASSIVE AUXILIARY FEEDWATER SYSTEM

    Directory of Open Access Journals (Sweden)

    YUN-JE CHO

    2013-11-01

    Full Text Available As passive safety features for nuclear power plants receive increasing attention, various studies have been conducted to develop safety systems for 3rd-generation (GEN-III nuclear power plants that are driven by passive systems. The Passive Auxiliary Feedwater System (PAFS is one of several passive safety systems being designed for the Advanced Power Reactor Plus (APR+, and extensive studies are being conducted to complete its design and to verify its feasibility. Because the PAFS removes decay heat from the reactor core under transient and accident conditions, it is necessary to evaluate the heat removal capability of the PAFS under hypothetical accident conditions. The heat removal capability of the PAFS is strongly dependent on the heat transfer at the condensate tube in Passive Condensation Heat Exchanger (PCHX. To evaluate the model of heat transfer coefficient for condensation, the Multi-dimensional Analysis of Reactor Safety (MARS code is used to simulate the experimental results from PAFS Condensing Heat Removal Assessment Loop (PASCAL. The Shah model, a default model for condensation heat transfer coefficient in the MARS code, under-predicts the experimental data from the PASCAL. To improve the calculation result, The Thome model and the new version of the Shah model are implemented and compared with the experimental data.

  3. A mathematical model for the performance assessment of engineering barriers of a typical near surface radioactive waste disposal facility

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, Raphaela N.; Rotunno Filho, Otto C. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Lab. de Hidrologia e Estudos do Meio Ambiente]. E-mail: otto@hidro.ufrj.br; Ruperti Junior, Nerbe J.; Lavalle Filho, Paulo F. Heilbron [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)]. E-mail: nruperti@cnen.gov.br

    2005-07-01

    This work proposes a mathematical model for the performance assessment of a typical radioactive waste disposal facility based on the consideration of a multiple barrier concept. The Generalized Integral Transform Technique is employed to solve the Advection-Dispersion mass transfer equation under the assumption of saturated one-dimensional flow, to obtain solute concentrations at given times and locations within the medium. A test-case is chosen in order to illustrate the performance assessment of several configurations of a multi barrier system adopted for the containment of sand contaminated with Ra-226 within a trench. (author)

  4. Alternate source term models for Yucca Mountain performance assessment based on natural analog data and secondary mineral solubility

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, W.M.; Codell, R.B.

    1999-07-01

    Performance assessment calculations for the proposed high level radioactive waste repository at Yucca Mountain, Nevada, were conducted using the Nuclear Regulatory Commission Total-System Performance Assessment (TPA 3.2) code to test conceptual models and parameter values for the source term based on data from the Pena Blanca, Mexico, natural analog site and based on a model for coprecipitation and solubility of secondary schoepite. In previous studies the value for the maximum constant oxidative alteration rate of uraninite at the Nopal I uranium body at Pena Blanca was estimated. Scaling this rate to the mass of uranium for the proposed Yucca Mountain repository yields an oxidative alteration rate of 22 kg/y, which was assumed to be an upper limit on the release rate from the proposed repository. A second model was developed assuming releases of radionuclides are based on the solubility of secondary schoepite as a function of temperature and solution chemistry. Releases of uranium are given by the product of uranium concentrations at equilibrium with schoepite and the flow of water through the waste packages. For both models, radionuclides other than uranium and those in the cladding and gap fraction were modeled to be released at a rate proportional to the uranium release rate, with additional elemental solubility limits applied. Performance assessment results using the Pena Blanca oxidation rate and schoepite solubility models for Yucca Mountain were compared to the TPA 3.2 base case model, in which release was based on laboratory studies of spent fuel dissolution, cladding and gap release, and solubility limits. Doses calculated using the release rate based on natural analog data and the schoepite solubility models were smaller than doses generated using the base case model. These results provide a degree of confidence in safety predictions using the base case model and an indication of how conservatism in the base case model may be reduced in future analyses.

  5. Energy performance assessment methodology

    Energy Technology Data Exchange (ETDEWEB)

    Platzer, W.J. [Fraunhofer Inst. for Solar Energy Systems, Freiburg (Germany)

    2006-01-15

    The energy performance of buildings are intimately connected to the energy performance of building envelopes. The better we understand the relation between the quality of the envelope and the energy consumption of the building, the better we can improve both. We have to consider not only heating but all service energies related to the human comfort in the building, such as cooling, ventilation, lighting as well. The complexity coming from this embracing approach is not to be underestimated. It is less and less possible to realted simple characteristic performance indicators of building envelopes (such as the U-value) to the overall energy performance. On the one hand much more paramters (e.g. light transmittance) come into the picture we have to assess the product quality in a multidimensional world. Secondly buildings more and more have to work on a narrow optimum: For an old, badly insulated building all solar gains are useful for a high-performance building with very good insulation and heat recovery systems in the ventilation overheating becomes more likely. Thus we have to control the solar gains, and sometimes we need high gains, sometimes low ones. And thirdly we see that the technology within the building and the user patterns and interactions as well influence the performance of a building envelope. The aim of this project within IEA Task27 was to improve our knowledge on the complex situation and also to give a principal approach how to assess the performance of the building envelope. The participants have contributed to this aim not pretending that we have reached the end. (au)

  6. Assessing the Impact of Equipment Aging on System Performance Using Simulation Modeling Methods

    International Nuclear Information System (INIS)

    Gupta, N. K.

    2005-01-01

    The radiological Inductively Coupled Plasma Mass Spectrometer (ICP-MS) is used to analyze the radioactive samples collected from different radioactive material processing operations at Savannah River Site (SRS). The expeditious processing of these samples is important for safe and reliable operations at SRS. As the radiological (RAD) ICP-MS machine ages, the experience shows that replacement parts and repairs are difficult to obtain on time for reliable operations after 5 years of service. A discrete event model using commercial software EXTEND was prepared to assess the impact on sample turn around times as the ICP-MS gets older. The model was prepared using the sample statistics from the previous 4 years. Machine utilization rates were calculated for the new machine, 5 year old machine, 10 year old machine, and a 12 year old machine. Computer simulations were run for these periods and the sample delay times calculated. The model was validated against the sample statistics collected from the previous 4 quarters. 90% confidence intervals were calculated for the 10th, 25th, 50th, and 90th quantiles of the samples. The simulation results show that if 50% of the samples are needed on time for efficient site operations, a 10 year old machine could take nearly 50 days longer to process these samples than a 5-year old machine. This simulation effort quantifies the impact on sample turn around time as the ICP-MS gets older

  7. Scenario sensitivity analyses performed on the PRESTO-EPA LLW risk assessment models

    International Nuclear Information System (INIS)

    Bandrowski, M.S.

    1988-01-01

    The US Environmental Protection Agency (EPA) is currently developing standards for the land disposal of low-level radioactive waste. As part of the standard development, EPA has performed risk assessments using the PRESTO-EPA codes. A program of sensitivity analysis was conducted on the PRESTO-EPA codes, consisting of single parameter sensitivity analysis and scenario sensitivity analysis. The results of the single parameter sensitivity analysis were discussed at the 1987 DOE LLW Management Conference. Specific scenario sensitivity analyses have been completed and evaluated. Scenario assumptions that were analyzed include: site location, disposal method, form of waste, waste volume, analysis time horizon, critical radionuclides, use of buffer zones, and global health effects

  8. Performance assessment modeling of high level nuclear wasteforms from the pyroprocess fuel cycle

    International Nuclear Information System (INIS)

    Nutt, W.M.; Hill, R.N.; Bullen, D.B.

    1995-01-01

    Several performance assessment (PA) analyses have been completed to estimate the release to the accessible environment of radionuclides from spent light water reactor (LWR) fuel emplaced in the proposed Yucca Mountain repository. Probabilistic methods were utilized based on the complexity of the repository system. Recent investigations have been conducted to identify the merits of a pyroprocess fuel cycle. This cycle utilizes high temperature molten salts and metals to partially separate actinides and fission products. In a closed liquid metal reactor (LMR) fuel cycle, this allows recycling of nearly all of the actinides. In a once-through cycle, this isolates the actinides for storage into a wasteform which can be specifically tailored for their retention. With appropriate front-end treatment, this Process can also be used to treat LWR spent fuel

  9. Performance of a Deep-Learning Neural Network Model in Assessing Skeletal Maturity on Pediatric Hand Radiographs.

    Science.gov (United States)

    Larson, David B; Chen, Matthew C; Lungren, Matthew P; Halabi, Safwan S; Stence, Nicholas V; Langlotz, Curtis P

    2018-04-01

    Purpose To compare the performance of a deep-learning bone age assessment model based on hand radiographs with that of expert radiologists and that of existing automated models. Materials and Methods The institutional review board approved the study. A total of 14 036 clinical hand radiographs and corresponding reports were obtained from two children's hospitals to train and validate the model. For the first test set, composed of 200 examinations, the mean of bone age estimates from the clinical report and three additional human reviewers was used as the reference standard. Overall model performance was assessed by comparing the root mean square (RMS) and mean absolute difference (MAD) between the model estimates and the reference standard bone ages. Ninety-five percent limits of agreement were calculated in a pairwise fashion for all reviewers and the model. The RMS of a second test set composed of 913 examinations from the publicly available Digital Hand Atlas was compared with published reports of an existing automated model. Results The mean difference between bone age estimates of the model and of the reviewers was 0 years, with a mean RMS and MAD of 0.63 and 0.50 years, respectively. The estimates of the model, the clinical report, and the three reviewers were within the 95% limits of agreement. RMS for the Digital Hand Atlas data set was 0.73 years, compared with 0.61 years of a previously reported model. Conclusion A deep-learning convolutional neural network model can estimate skeletal maturity with accuracy similar to that of an expert radiologist and to that of existing automated models. © RSNA, 2017 An earlier incorrect version of this article appeared online. This article was corrected on January 19, 2018.

  10. Comparative Analysis of Infrared Thermography and CFD Modelling for Assessing the Thermal Performance of Buildings

    Directory of Open Access Journals (Sweden)

    Carlos Morón

    2018-03-01

    Full Text Available Energy consumption in the building sector has increased significantly in the developed countries over the last decades. For this reason, the new European standards have become stricter in terms of energy saving. This paper establishes a comparison between using infrared thermography for technical building inspection and modelling with Computational Flow Dynamics (CFD tools for the study of thermal performance of the building. The results show that the use of this type of tools gives a reliable response with the difference in thermal changes lower than 0.5 °C with respect to the data taken in situ. Moreover, these simulators of flow dynamics allow to evaluate the efficiency of proposed measures for energy savings and to obtain a reliable approximation to thermal comfort applying the improvement, deepening in the surface analysis of infrared thermography before performing rehabilitation project. In this research, Predicted Mean Vote Index (PMV comfort index of 0.7 for a living room and 0.6 for a bedroom were obtained, that corresponds to C class that includes values in the range of −0.7 < PMV < 0.7 according to the standard UNE-EN 7730.

  11. Nuclear Energy Advanced Modeling and Simulation (NEAMS) waste Integrated Performance and Safety Codes (IPSC) : gap analysis for high fidelity and performance assessment code development.

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joon H.; Siegel, Malcolm Dean; Arguello, Jose Guadalupe, Jr.; Webb, Stephen Walter; Dewers, Thomas A.; Mariner, Paul E.; Edwards, Harold Carter; Fuller, Timothy J.; Freeze, Geoffrey A.; Jove-Colon, Carlos F.; Wang, Yifeng

    2011-03-01

    This report describes a gap analysis performed in the process of developing the Waste Integrated Performance and Safety Codes (IPSC) in support of the U.S. Department of Energy (DOE) Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Campaign. The goal of the Waste IPSC is to develop an integrated suite of computational modeling and simulation capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive waste storage or disposal system. The Waste IPSC will provide this simulation capability (1) for a range of disposal concepts, waste form types, engineered repository designs, and geologic settings, (2) for a range of time scales and distances, (3) with appropriate consideration of the inherent uncertainties, and (4) in accordance with rigorous verification, validation, and software quality requirements. The gap analyses documented in this report were are performed during an initial gap analysis to identify candidate codes and tools to support the development and integration of the Waste IPSC, and during follow-on activities that delved into more detailed assessments of the various codes that were acquired, studied, and tested. The current Waste IPSC strategy is to acquire and integrate the necessary Waste IPSC capabilities wherever feasible, and develop only those capabilities that cannot be acquired or suitably integrated, verified, or validated. The gap analysis indicates that significant capabilities may already exist in the existing THC codes although there is no single code able to fully account for all physical and chemical processes involved in a waste disposal system. Large gaps exist in modeling chemical processes and their couplings with other processes. The coupling of chemical processes with flow transport and mechanical deformation remains challenging. The data for extreme environments (e.g., for elevated temperature and high ionic strength media) that are

  12. Generation and performance assessment of the global TanDEM-X digital elevation model

    Science.gov (United States)

    Rizzoli, Paola; Martone, Michele; Gonzalez, Carolina; Wecklich, Christopher; Borla Tridon, Daniela; Bräutigam, Benjamin; Bachmann, Markus; Schulze, Daniel; Fritz, Thomas; Huber, Martin; Wessel, Birgit; Krieger, Gerhard; Zink, Manfred; Moreira, Alberto

    2017-10-01

    The primary objective of the TanDEM-X mission is the generation of a global, consistent, and high-resolution digital elevation model (DEM) with unprecedented global accuracy. The goal is achieved by exploiting the interferometric capabilities of the two twin SAR satellites TerraSAR-X and TanDEM-X, which fly in a close orbit formation, acting as an X-band single-pass interferometer. Between December 2010 and early 2015 all land surfaces have been acquired at least twice, difficult terrain up to seven or eight times. The acquisition strategy, data processing, and DEM calibration and mosaicking have been systematically monitored and optimized throughout the entire mission duration, in order to fulfill the specification. The processing of all data has finally been completed in September 2016 and this paper reports on the final performance of the TanDEM-X global DEM and presents the acquisition and processing strategy which allowed to obtain the final DEM quality. The results confirm the outstanding global accuracy of the delivered product, which can be now utilized for both scientific and commercial applications.

  13. SIMPLIFIED PREDICTIVE MODELS FOR CO₂ SEQUESTRATION PERFORMANCE ASSESSMENT RESEARCH TOPICAL REPORT ON TASK #3 STATISTICAL LEARNING BASED MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Srikanta; Schuetter, Jared

    2014-11-01

    We compare two approaches for building a statistical proxy model (metamodel) for CO₂ geologic sequestration from the results of full-physics compositional simulations. The first approach involves a classical Box-Behnken or Augmented Pairs experimental design with a quadratic polynomial response surface. The second approach used a space-filling maxmin Latin Hypercube sampling or maximum entropy design with the choice of five different meta-modeling techniques: quadratic polynomial, kriging with constant and quadratic trend terms, multivariate adaptive regression spline (MARS) and additivity and variance stabilization (AVAS). Simulations results for CO₂ injection into a reservoir-caprock system with 9 design variables (and 97 samples) were used to generate the data for developing the proxy models. The fitted models were validated with using an independent data set and a cross-validation approach for three different performance metrics: total storage efficiency, CO₂ plume radius and average reservoir pressure. The Box-Behnken–quadratic polynomial metamodel performed the best, followed closely by the maximin LHS–kriging metamodel.

  14. Power performance assessment. Final report

    International Nuclear Information System (INIS)

    Frandsen, S.

    1998-12-01

    In the increasingly commercialised wind power marketplace, the lack of precise assessment methods for the output of an investment is becoming a barrier for wider penetration of wind power. Thus, addressing this problem, the overall objectives of the project are to reduce the financial risk in investment in wind power projects by significantly improving the power performance assessment methods. Ultimately, if this objective is successfully met, the project may also result in improved tuning of the individual wind turbines and in optimisation methods for wind farm operation. The immediate, measurable objectives of the project are: To prepare a review of existing contractual aspects of power performance verification procedures of wind farms; to provide information on production sensitivity to specific terrain characteristics and wind turbine parameters by analyses of a larger number of wind farm power performance data available to the proposers; to improve the understanding of the physical parameters connected to power performance in complex environment by comparing real-life wind farm power performance data with 3D computational flow models and 3D-turbulence wind turbine models; to develop the statistical framework including uncertainty analysis for power performance assessment in complex environments; and to propose one or more procedures for power performance evaluation of wind power plants in complex environments to be applied in contractual agreements between purchasers and manufacturers on production warranties. Although the focus in this project is on power performance assessment the possible results will also be of benefit to energy yield forecasting, since the two tasks are strongly related. (au) JOULE III. 66 refs.; In Co-operation Renewable Energy System Ltd. (GB); Centre for Renewable Energy (GR); Aeronautic Research Centre (SE); National Engineering Lab. (GB); Public Power Cooperation (GR)

  15. A Multi-Methods Approach to HRA and Human Performance Modeling: A Field Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Jacques Hugo; David I Gertman

    2012-06-01

    The Advanced Test Reactor (ATR) is a research reactor at the Idaho National Laboratory is primarily designed and used to test materials to be used in other, larger-scale and prototype reactors. The reactor offers various specialized systems and allows certain experiments to be run at their own temperature and pressure. The ATR Canal temporarily stores completed experiments and used fuel. It also has facilities to conduct underwater operations such as experiment examination or removal. In reviewing the ATR safety basis, a number of concerns were identified involving the ATR canal. A brief study identified ergonomic issues involving the manual handling of fuel elements in the canal that may increase the probability of human error and possible unwanted acute physical outcomes to the operator. In response to this concern, that refined the previous HRA scoping analysis by determining the probability of the inadvertent exposure of a fuel element to the air during fuel movement and inspection was conducted. The HRA analysis employed the SPAR-H method and was supplemented by information gained from a detailed analysis of the fuel inspection and transfer tasks. This latter analysis included ergonomics, work cycles, task duration, and workload imposed by tool and workplace characteristics, personal protective clothing, and operational practices that have the potential to increase physical and mental workload. Part of this analysis consisted of NASA-TLX analyses, combined with operational sequence analysis, computational human performance analysis (CHPA), and 3D graphical modeling to determine task failures and precursors to such failures that have safety implications. Experience in applying multiple analysis techniques in support of HRA methods is discussed.

  16. A Multi-Methods Approach to HRA and Human Performance Modeling: A Field Assessment

    International Nuclear Information System (INIS)

    Hugo, Jacques; Gertman, David I.

    2012-01-01

    The Advanced Test Reactor (ATR) is a research reactor at the Idaho National Laboratory is primarily designed and used to test materials to be used in other, larger-scale and prototype reactors. The reactor offers various specialized systems and allows certain experiments to be run at their own temperature and pressure. The ATR Canal temporarily stores completed experiments and used fuel. It also has facilities to conduct underwater operations such as experiment examination or removal. In reviewing the ATR safety basis, a number of concerns were identified involving the ATR canal. A brief study identified ergonomic issues involving the manual handling of fuel elements in the canal that may increase the probability of human error and possible unwanted acute physical outcomes to the operator. In response to this concern, that refined the previous HRA scoping analysis by determining the probability of the inadvertent exposure of a fuel element to the air during fuel movement and inspection was conducted. The HRA analysis employed the SPAR-H method and was supplemented by information gained from a detailed analysis of the fuel inspection and transfer tasks. This latter analysis included ergonomics, work cycles, task duration, and workload imposed by tool and workplace characteristics, personal protective clothing, and operational practices that have the potential to increase physical and mental workload. Part of this analysis consisted of NASA-TLX analyses, combined with operational sequence analysis, computational human performance analysis (CHPA), and 3D graphical modeling to determine task failures and precursors to such failures that have safety implications. Experience in applying multiple analysis techniques in support of HRA methods is discussed.

  17. An integrated environmental modeling framework for performing Quantitative Microbial Risk Assessments

    Science.gov (United States)

    Standardized methods are often used to assess the likelihood of a human-health effect from exposure to a specified hazard, and inform opinions and decisions about risk management and communication. A Quantitative Microbial Risk Assessment (QMRA) is specifically adapted to detail ...

  18. GIFMod: A Flexible Modeling Framework For Hydraulic and Water Quality Performance Assessment of Stormwater Green Infrastructure

    Science.gov (United States)

    A flexible framework has been created for modeling multi-dimensional hydrological and water quality processes within stormwater green infrastructures (GIs). The framework models a GI system using a set of blocks (spatial features) and connectors (interfaces) representing differen...

  19. Performance assessment of the Greater Confinement Disposal facility on the Nevada Test Site: Comparing the performance of two conceptual site models

    International Nuclear Information System (INIS)

    Baer, T.A.; Price, L.L.; Gallegos, D.P.

    1993-01-01

    A small amount of transuranic (TRU) waste has been disposed of at the Greater Confinement Disposal (GCD) site located on the Nevada Test Site's (NTS) Radioactive Waste Management Site (RWMS). The waste has been buried in several deep (37 m) boreholes dug into the floor of an alluvial basin. For the waste to remain in its current configuration, the DOE must demonstrate compliance of the site with the TRU disposal requirements, 40 CFR 191. Sandia's approach to process modelling in performance assessment is to use demonstrably conservative models of the site. Choosing the most conservative model, however, can be uncertain. As an example, diffusion of contaminants upward from the buried waste in the vadose zone water is the primary mechanism of release. This process can be modelled as straight upward planar diffusion or as spherical diffusion in all directions. The former has high fluxes but low release areas, the latter has lower fluxes but is spread over a greater area. We have developed analytic solutions to a simple test problem for both models and compared the total integrated discharges. The spherical diffusion conceptual model results in at least five times greater release to the accessible environment than the planar model at all diffusivities. Modifying the planar model to allow for a larger release, however, compensated for the smaller original planar discharge and resulted in a new planar model that was more conservative that the spherical model except at low diffusivities

  20. Validation of transport models for use in repository performance assessments: a view illustrated for INTRAVAL test case 1b

    International Nuclear Information System (INIS)

    Jackson, C.P.; Lever, D.A.; Sumner, P.J.

    1991-03-01

    We present our views on validation. We consider that validation is slightly different for general models and specific models. We stress the importance of presenting for review the case for (or against) a model. We outline a formal framework for validation, which helps to ensure that all the issues are addressed. Our framework includes calibration, testing predictions, comparison with alternative models, which we consider particularly important, analysis of discrepancies, presentation, consideration of implications and suggested improved experiments. We illustrate the approach by application to an INTRAVAL test case based on laboratory experiments. Three models were considered: a simple model that included the effects of advection, dispersion and equilibrium sorption, a model that also included the effects of rock-matrix diffusion, and a model with kinetic sorption. We show that the model with rock-matrix diffusion is the only one to provide a good description of the data. We stress the implications of extrapolating to larger length and time scales for repository performance assessments. (author)

  1. Methodology for NDA performance assessment

    International Nuclear Information System (INIS)

    Cuypers, M.; Franklin, M.; Guardini, S.

    1986-01-01

    In the framework of the RandD programme of the Joint Research Centre of the Commission of the European Communities, a considerable effort is being dedicated to performance assessment of NDA techniques taking account of field conditions. By taking account of field conditions is meant measurement samples of the size encountered in practice and training which allows inspectors to design cost efficient verification plans for the real situations encountered in the field. Special laboratory facilities referred to as PERLA are being constructed for this purpose. These facilities will be used for measurement experiments and for training. In this paper, performance assessment is discussed under the headings of measurement capability and in-field effectiveness. Considerable emphasis is given to the role of method specific measurement error models. The authors outline the advantages of giving statistical error models a sounder basis in the physical phenomenology of the measurement method

  2. Total System Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Yong Soo; Kang, Chul Hyung; Lee, Youn Myoung; Han, Ji Woong; Choi, Jong Won; Hahn, Pil Soo; Park, Jeong Hwa; Jeong, Mi Seon

    2007-06-15

    Based on the KAERI FEP list developed through the previous studies, the KAERI FEP Encyclopedia has been developed. Current version is 1.0 which includes all relevant FEPs to compose of two references and all alternative scenarios. Many interaction FEPs between scenario defining FEP(SDF) are created throughout the study. FEPs are classified into many Integrated FEP(IFEP) which eventually become the elements of the RES matrix. The FEAS program one of the component of the KAERI's CYPRUS information system is added to develop the FEP, RES, AC, AMF and finally scenarios. It assists to create transparent way to deal with assessment from the stage of the planning of the R and D to the final stage of the external audit and regulatory body review. Even though MASCOT-K and compartment analysis codes such as AMBER, GoldSim and Ecolego are excellent for TSPA they by in heritage possess a certain limitation especially to identify a proper migration cross sectional area when a relatively big component intersects with a tiny one such as a fracture. It is truly 3D phenomena in nature. MDPSA code is developed which is expected to overcome limitations in compartment models while successfully deals with natural disruptive events. The R and D target for the TSPA is to develop the sufficient scenarios and their variation cases to understand the safety of KRS in every possible aspect. For this, reference scenarios, alternative scenarios covering engineered barrier failure and natural events are developed and assessed respectively for around 100 cases. The stylized template to assess the Korean reference biosphere is developed using the AMBER. Three critical groups, agricultural, freshwater and marine water fishing groups are identified to assess the DCF following the guidelines of ICRP. Based on the QA principles of T2R3, the web based QA system is developed using the procedures in the USNRC 10CFR50 Appendix B. The QA system is combined with the PAID and FEAS to create the

  3. Total System Performance Assessment

    International Nuclear Information System (INIS)

    Hwang, Yong Soo; Kang, Chul Hyung; Lee, Youn Myoung; Han, Ji Woong; Choi, Jong Won; Hahn, Pil Soo; Park, Jeong Hwa; Jeong, Mi Seon

    2007-06-01

    Based on the KAERI FEP list developed through the previous studies, the KAERI FEP Encyclopedia has been developed. Current version is 1.0 which includes all relevant FEPs to compose of two references and all alternative scenarios. Many interaction FEPs between scenario defining FEP(SDF) are created throughout the study. FEPs are classified into many Integrated FEP(IFEP) which eventually become the elements of the RES matrix. The FEAS program one of the component of the KAERI's CYPRUS information system is added to develop the FEP, RES, AC, AMF and finally scenarios. It assists to create transparent way to deal with assessment from the stage of the planning of the R and D to the final stage of the external audit and regulatory body review. Even though MASCOT-K and compartment analysis codes such as AMBER, GoldSim and Ecolego are excellent for TSPA they by in heritage possess a certain limitation especially to identify a proper migration cross sectional area when a relatively big component intersects with a tiny one such as a fracture. It is truly 3D phenomena in nature. MDPSA code is developed which is expected to overcome limitations in compartment models while successfully deals with natural disruptive events. The R and D target for the TSPA is to develop the sufficient scenarios and their variation cases to understand the safety of KRS in every possible aspect. For this, reference scenarios, alternative scenarios covering engineered barrier failure and natural events are developed and assessed respectively for around 100 cases. The stylized template to assess the Korean reference biosphere is developed using the AMBER. Three critical groups, agricultural, freshwater and marine water fishing groups are identified to assess the DCF following the guidelines of ICRP. Based on the QA principles of T2R3, the web based QA system is developed using the procedures in the USNRC 10CFR50 Appendix B. The QA system is combined with the PAID and FEAS to create the comprehensive

  4. Performance assessment and parameterization of the SWAP-WOFOST model for peat soil under agricultural use in northern Europe.

    Science.gov (United States)

    Bertram, Sascha; Bechtold, Michel; Hendriks, Rob; Piayda, Arndt; Regina, Kristiina; Myllys, Merja; Tiemeyer, Bärbel

    2017-04-01

    Peat soils form a major share of soil suitable for agriculture in northern Europe. Successful agricultural production depends on hydrological and pedological conditions, local climate and agricultural management. Climate change impact assessment on food production and development of mitigation and adaptation strategies require reliable yield forecasts under given emission scenarios. Coupled soil hydrology - crop growth models, driven by regionalized future climate scenarios are a valuable tool and widely used for this purpose. Parameterization on local peat soil conditions and crop breed or grassland specie performance, however, remains a major challenge. The subject of this study is to evaluate the performance and sensitivity of the SWAP-WOFOST coupled soil hydrology and plant growth model with respect to the application on peat soils under different regional conditions across northern Europe. Further, the parameterization of region-specific crop and grass species is discussed. First results of the model application and parameterization at deep peat sites in southern Finland are presented. The model performed very well in reproducing two years of observed, daily ground water level data on four hydrologically contrasting sites. Naturally dry and wet sites could be modelled with the same performance as sites with active water table management by regulated drains in order to improve peat conservation. A simultaneous multi-site calibration scheme was used to estimate plant growth parameters of the local oat breed. Cross-site validation of the modelled yields against two years of observations proved the robustness of the chosen parameter set and gave no indication of possible overparameterization. This study proves the suitability of the coupled SWAP-WOFOST model for the prediction of crop yields and water table dynamics of peat soils in agricultural use under given climate conditions.

  5. Assessment of the service performance of drainage system and transformation of pipeline network based on urban combined sewer system model.

    Science.gov (United States)

    Peng, Hai-Qin; Liu, Yan; Wang, Hong-Wu; Ma, Lu-Ming

    2015-10-01

    In recent years, due to global climate change and rapid urbanization, extreme weather events occur to the city at an increasing frequency. Waterlogging is common because of heavy rains. In this case, the urban drainage system can no longer meet the original design requirements, resulting in traffic jams and even paralysis and post a threat to urban safety. Therefore, it provides a necessary foundation for urban drainage planning and design to accurately assess the capacity of the drainage system and correctly simulate the transport effect of drainage network and the carrying capacity of drainage facilities. This study adopts InfoWorks Integrated Catchment Management (ICM) to present the two combined sewer drainage systems in Yangpu District, Shanghai (China). The model can assist the design of the drainage system. Model calibration is performed based on the historical rainfall events. The calibrated model is used for the assessment of the outlet drainage and pipe loads for the storm scenario currently existing or possibly occurring in the future. The study found that the simulation and analysis results of the drainage system model were reliable. They could fully reflect the service performance of the drainage system in the study area and provide decision-making support for regional flood control and transformation of pipeline network.

  6. Use of GIS and 3D Modeling for Development and Conceptualization of a Performance Assessment Model for Decommissioning of a Complex Site

    International Nuclear Information System (INIS)

    Esh, D. W.; Gross, A. J.; Thaggard, M.

    2006-01-01

    Geographic Information Systems (GIS) and 3D geo-spatial modeling were employed to facilitate development and conceptualization of a performance assessment (PA) model that will be used to evaluate the health impacts of residual radioactivity at a former nuclear materials processing facility site in New York. Previous operations have resulted in a number of different sources of radiological contamination that must be assessed during site decommissioning. A performance assessment model is being developed to estimate radiological dose to potential receptors through the simulation of the release and transport of radionuclides, and exposure to residual contamination for hundreds to thousands of years in the future. A variety of inputs are required to parameterize the performance assessment model, such as: distance from the waste to surface water bodies, thickness of geologic units for saturated transport, saturated thickness of the geologic units, and spatial and temporal average of percent of waste that is saturated. GIS and 3D modeling are used to analyze and abstract aleatory uncertainty associated with the dimensionality of the geologic system into epistemic uncertainty for one- and two-dimensional process models for flow and transport of radionuclides. Three-dimensional geo-spatial modeling was used to develop the geologic framework and the geometrical representation of the residual contamination within the geologic framework. GIS was used in the initial development and parameterization of the transport pathways, to provide spatial context to the PA model, and to link it to the 3D geologic framework and contamination geometry models. Both the GIS and 3-D modeling were used to interpret the results of runs of the PA model. (authors)

  7. Preliminary assessment of the performance of a global coupled atmosphere-ocean model

    International Nuclear Information System (INIS)

    Cubasch, U.

    1990-01-01

    A low-resolution version of the ECMWF global atmosphere model has been coupled to a global ocean model developed at the Max Planck Institute in Hamburg. The atmosphere model is driven by the sea surface temperature and the ice thickness calculated by the ocean model, which, in return, is driven by the wind stress, the heat flux and the freshwater flux diagnosed by the atmosphere model. Even though each model reaches stationarity when integrated on its own, the coupling of both creates problems, since the fields calculated by each model are not consistent with the ones the other model has to have in order to stay stationary, because some of the fluxes are not balanced. In the coupled experiment the combined ocean-atmosphere system drifts toward a colder state. To counteract this problem, a flux correction has been applied which balances the mean biases of each model. This method almost eliminates the climate drift of the coupled model. Problems still arise over ice covered regions

  8. Assessment of three turbulence model performances in predicting water jet flow plunging into a liquid pool

    Directory of Open Access Journals (Sweden)

    Zidouni Kendil Faiza

    2010-01-01

    Full Text Available The main purpose of the current study is to numerically investigate, through computational fluid dynamics modeling, a water jet injected vertically downward through a straight circular pipe into a water bath. The study also aims to obtain a better understanding of jet behavior, air entrainment and the dispersion of bubbles in the developing flow region. For these purposes, three dimensional air and water flows were modeled using the volume of fluid technique. The equations in question were formulated using the density and viscosity of a 'gas-liquid mixture', described in terms of the phase volume fraction. Three turbulence models with a high Reynolds number have been considered i. e. the standard k-e model, realizable k-e model, and Reynolds stress model. The predicted flow patterns for the realizable k-e model match well with experimental measurements found in available literature. Nevertheless, some discrepancies regarding velocity relaxation and turbulent momentum distribution in the pool are still observed for both the standard k-e and the Reynolds stress model.

  9. Maximizing Energy Savings Reliability in BC Hydro Industrial Demand-side Management Programs: An Assessment of Performance Incentive Models

    Science.gov (United States)

    Gosman, Nathaniel

    of alternative performance incentive program models to manage DSM risk in BC. Three performance incentive program models were assessed and compared to BC Hydro's current large industrial DSM incentive program, Power Smart Partners -- Transmission Project Incentives, itself a performance incentive-based program. Together, the selected program models represent a continuum of program design and implementation in terms of the schedule and level of incentives provided, the duration and rigour of measurement and verification (M&V), energy efficiency measures targeted and involvement of the private sector. A multi criteria assessment framework was developed to rank the capacity of each program model to manage BC large industrial DSM risk factors. DSM risk management rankings were then compared to program costeffectiveness, targeted energy savings potential in BC and survey results from BC industrial firms on the program models. The findings indicate that the reliability of DSM energy savings in the BC large industrial sector can be maximized through performance incentive program models that: (1) offer incentives jointly for capital and low-cost operations and maintenance (O&M) measures, (2) allow flexible lead times for project development, (3) utilize rigorous M&V methods capable of measuring variable load, process-based energy savings, (4) use moderate contract lengths that align with effective measure life, and (5) integrate energy management software tools capable of providing energy performance feedback to customers to maximize the persistence of energy savings. While this study focuses exclusively on the BC large industrial sector, the findings of this research have applicability to all energy utilities serving large, energy intensive industrial sectors.

  10. Microcomputer simulation model for facility performance assessment: a case study of nuclear spent fuel handling facility operations

    Energy Technology Data Exchange (ETDEWEB)

    Chockie, A.D.; Hostick, C.J.; Otis, P.T.

    1985-10-01

    A microcomputer based simulation model was recently developed at the Pacific Northwest Laboratory (PNL) to assist in the evaluation of design alternatives for a proposed facility to receive, consolidate and store nuclear spent fuel from US commercial power plants. Previous performance assessments were limited to deterministic calculations and Gantt chart representations of the facility operations. To insure that the design of the facility will be adequate to meet the specified throughput requirements, the simulation model was used to analyze such factors as material flow, equipment capability and the interface between the MRS facility and the nuclear waste transportation system. The simulation analysis model was based on commercially available software and application programs designed to represent the MRS waste handling facility operations. The results of the evaluation were used by the design review team at PNL to identify areas where design modifications should be considered. 4 figs.

  11. Is there a relationship between health care models and their performance assessment? The results of an extensive review

    Directory of Open Access Journals (Sweden)

    Ferruccio Pelone

    2008-06-01

    evaluate health care systems performance is recognized, there is not agreement on what concepts and dimensions of performance should be measured. Our study underlines an interesting link between the domains/dimensions of performance assessment and models of health care systems.

  12. Tracking Student Achievement in Music Performance: Developing Student Learning Objectives for Growth Model Assessments

    Science.gov (United States)

    Wesolowski, Brian C.

    2015-01-01

    Student achievement growth data are increasingly used for assessing teacher effectiveness and tracking student achievement in the classroom. Guided by the student learning objective (SLO) framework, music teachers are now responsible for collecting, tracking, and reporting student growth data. Often, the reported data do not accurately reflect the…

  13. An Assessment of the CF Submarine Watch Schedule Variants for Impact on Modeled Crew Performance

    National Research Council Canada - National Science Library

    Paul, Michel A; Gray, Gary W; Nesthus, Thomas E; Miller, James C

    2008-01-01

    .... Therefore DRDC Toronto was tasked to conduct an at-sea trial, this time using real actigraphically-derived sleep data in order to more accurately model the impact of the watch schedule on crew cognitive effectiveness...

  14. U.S. and Australian Mine Warfare Sonar Performance Assessment Using SWAT and Hodgson Models

    National Research Council Canada - National Science Library

    Dubsky, Barbra

    2000-01-01

    The purpose of this thesis was to investigate a shallow coastal region to compile a detailed environmental picture of its sediment composition and water characteristics and from this model MCM sonar...

  15. An Assessment of the CF Submarine Watch Schedule Variants for Impact on Modeled Crew Performance

    National Research Council Canada - National Science Library

    Paul, Michel A; Gray, Gary W; Nesthus, Thomas E; Miller, James C

    2008-01-01

    In support of the Board of Inquiry (BOI) investigating the October 2005 fire on board HMCS Chicoutirni, DRDC Toronto was asked to model crew cognitive effectiveness at the time of the fire and at the time of casualty evacuation...

  16. On integrating modeling software for application to total-system performance assessment

    International Nuclear Information System (INIS)

    Lewis, L.C.; Wilson, M.L.

    1994-05-01

    We examine the processes and methods used to facilitate collaboration in software development between two organizations at separate locations -- Lawrence Livermore National Laboratory (LLNL) in California and Sandia National Laboratories (SNL) in New Mexico. Our software development process integrated the efforts of these two laboratories. Software developed at LLNL to model corrosion and failure of waste packages and subsequent releases of radionuclides was incorporated as a source term into SNLs computer models for fluid flow and radionuclide transport through the geosphere

  17. Flight Attendant Work/Rest Patterns, Alertness, and Performance Assessment: Field Validation of Biomathematical Fatigue Modeling

    Science.gov (United States)

    2012-09-01

    several dynamic components such as a homeostatic sleep reservoir, circadian oscillator, and sleep inertia function (see Figure 1). Final cognitive...for example, via differences in sleep need, sleep inertia , or circadian phasing and amplitude. As we have seen in the present study and others...safety risks. The Sleep , Activity, Fatigue, and Task Effectiveness model (SAFTE; Hursh et al., 2004) is among the more mature fatigue models currently

  18. Quality assurance criteria for Waste Isolation Pilot Plant performance assessment modeling

    International Nuclear Information System (INIS)

    1995-07-01

    The US Department of Energy (DOE) is developing the Waste Isolation Pilot Plant (WIPP) as a deep geologic repository for transuranic (TRU) and TRU-mixed wastes generated by DOE Defense Program activities. Regulatory agencies, including the Environmental Protection Agency (EPA) and New Mexico Environment Department, will be forced to rely upon system modeling to determine the potential compliance of the WIPP facility with federal regulations. Specifically, long-term modeling efforts are focused on compliance with 40 CFR Part 268, ''Land Disposal Restrictions,'' and 40 CFR Part 191, ''Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level, and Transuranic Radioactive Wastes.'' DOE plans to use the similar conceptual models and numerical codes to demonstrate compliance under both of these regulations. Sandia National Laboratories (SNL) has been developing a system model that will be used to demonstrate potential waste migration from the WIPP facility. Because the geologic system underlying the WIPP site is not completely understood, the software code to model the system must be developed to exacting standards for its predictions to be reliable and defensible. This is a complex model that consists of many submodules used to describe various migration pathways and processes that affect potential waste migration

  19. Georgia's Teacher Performance Assessment

    Science.gov (United States)

    Fenton, Anne Marie; Wetherington, Pamela

    2016-01-01

    Like most states, Georgia until recently depended on an assessment of content knowledge to award teaching licenses, along with a licensure recommendation from candidates' educator preparation programs. While the content assessment reflected candidates' grasp of subject matter, licensure decisions did not hinge on direct, statewide assessment of…

  20. Sensitivity analysis of a discrete fracture network model for performance assessment of Aberg

    International Nuclear Information System (INIS)

    Outters, N.; Shuttle, D.

    2000-12-01

    This report presents a sensitivity analysis of pathway simulations in a DFN model. The DFN model consists of two sets of stochastic fractures at different scales and the canister locations of a hypothetical repository layout. The hydrogeological base case model is defined by constant head boundary conditions on the edges of a 2000 x 2000 x 1000 m 3 block. The pathway analysis carried out by the program PAWorks provides pathway parameters (pathway length, pathway width, transport aperture, reactive surface area, pathway transmissivity), canister statistics (average number of pathways per canister, percentage of canister locations with pathways) and visualisation of pathways. The project provided the following results from the alternative cases: Case 1: Model with a 100 m thick fracture network at the repository scale instead of 50 m in the base case. The model is little sensitive to the increase of the thickness of the local fracture network. Case 2: Model including fracture networks where the mean size and size standard deviation is twice the ones used in the base case. The travel times to the biosphere is slightly shortened by increasing the fracture diameter. Case 3: Two models with alternative hydraulic boundary conditions: two different flux boundary conditions are tested instead of head boundary conditions in the base case. The advective travel time is shortened by changing the boundary conditions in both alternative cases; in some cases it is reduced to less than a year. Case 4: Study of alternative pathway search algorithms: the pathway search is here based on minimum travel time. The pathway search algorithm of PAWorks based on minimum travel time gives much more optimistic results than the base case where the maximum flow rate was used. The mean travel time is about 5000 years. Due to editorial reasons only a subset of all this information is treated in this report

  1. The international hydrocoin project. Groundwater hydrology modelling strategies for performance assessment of nuclear waste disposal

    International Nuclear Information System (INIS)

    1990-01-01

    The international co-operation project HYDROCOIN for studying groundwater flow modelling in the context of radioactive waste disposal was initiated in 1984. Thirteen organizations from ten countries and two international organizations have participated in the project which has been managed by the Swedish Nuclear Power Inspectorate, SKI. This report summarizes the results from the second phase of HYDROCOIN, Level 2, which has addressed the issue of validation by testing the capabilities of groundwater flow models to describe five field and laboratory experiments: . Thermal convection and conduction around a field heat transfer experiment in a quarry, . A laboratory experiment with thermal convection as a model for variable density flow, . A small groundwater flow system in fractured monzonitic gneiss, . Three-dimensional regional groundwater flow in low permeability rocks, and . Soil water redistribution near the surface at a field site. The five test cases cover various media of interest for final disposal such as low permeability saturated rock, unsaturated rock, and salt formations. They also represent a variety of spatial and temporal scales. From model simulations on the five test cases conclusions are drawn regarding the applicability of the models to the experimental and field situations and the usefulness of the available data bases. The results are evaluated with regard to the steps in an ideal validation process. The data bases showed certain limitations for validation purposes with respect to independent data sets for calibration and validation. In spite of this, the HYDROCOIN Level 2 efforts have significantly contributed to an increased confidence in the applicability of groundwater flow models to different situations relevant to final disposal. Furthermore, the work has given much insight into the validation process and specific recommendations for further validation efforts are made

  2. Enhanced DEA model with undesirable output and interval data for rice growing farmers performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Sahubar Ali Mohd. Nadhar, E-mail: sahubar@uum.edu.my; Ramli, Razamin, E-mail: razamin@uum.edu.my; Baten, M. D. Azizul, E-mail: baten-math@yahoo.com [School of Quantitative Sciences, UUM College of Arts and Sciences, Universiti Utara Malaysia, 06010 Sintok, Kedah (Malaysia)

    2015-12-11

    Agricultural production process typically produces two types of outputs which are economic desirable as well as environmentally undesirable outputs (such as greenhouse gas emission, nitrate leaching, effects to human and organisms and water pollution). In efficiency analysis, this undesirable outputs cannot be ignored and need to be included in order to obtain the actual estimation of firms efficiency. Additionally, climatic factors as well as data uncertainty can significantly affect the efficiency analysis. There are a number of approaches that has been proposed in DEA literature to account for undesirable outputs. Many researchers has pointed that directional distance function (DDF) approach is the best as it allows for simultaneous increase in desirable outputs and reduction of undesirable outputs. Additionally, it has been found that interval data approach is the most suitable to account for data uncertainty as it is much simpler to model and need less information regarding its distribution and membership function. In this paper, an enhanced DEA model based on DDF approach that considers undesirable outputs as well as climatic factors and interval data is proposed. This model will be used to determine the efficiency of rice farmers who produces undesirable outputs and operates under uncertainty. It is hoped that the proposed model will provide a better estimate of rice farmers’ efficiency.

  3. Assessing the performance of variational methods for mixed logistic regression models

    NARCIS (Netherlands)

    Rijmen, F.P.J.; Vomlel, J.

    2008-01-01

    We present a variational estimation method for the mixed logistic regression model. The method is based on a lower bound approximation of the logistic function [Jaakkola, J.S. and Jordan, M.I., 2000, Bayesian parameter estimation via variational methods. Statistics Computing, 10, 25-37.]. Based on

  4. Enhanced DEA model with undesirable output and interval data for rice growing farmers performance assessment

    Science.gov (United States)

    Khan, Sahubar Ali Mohd. Nadhar; Ramli, Razamin; Baten, M. D. Azizul

    2015-12-01

    Agricultural production process typically produces two types of outputs which are economic desirable as well as environmentally undesirable outputs (such as greenhouse gas emission, nitrate leaching, effects to human and organisms and water pollution). In efficiency analysis, this undesirable outputs cannot be ignored and need to be included in order to obtain the actual estimation of firms efficiency. Additionally, climatic factors as well as data uncertainty can significantly affect the efficiency analysis. There are a number of approaches that has been proposed in DEA literature to account for undesirable outputs. Many researchers has pointed that directional distance function (DDF) approach is the best as it allows for simultaneous increase in desirable outputs and reduction of undesirable outputs. Additionally, it has been found that interval data approach is the most suitable to account for data uncertainty as it is much simpler to model and need less information regarding its distribution and membership function. In this paper, an enhanced DEA model based on DDF approach that considers undesirable outputs as well as climatic factors and interval data is proposed. This model will be used to determine the efficiency of rice farmers who produces undesirable outputs and operates under uncertainty. It is hoped that the proposed model will provide a better estimate of rice farmers' efficiency.

  5. Assessment of Student Performance for Course Examination Using Rasch Measurement Model: A Case Study of Information Technology Fundamentals Course

    Directory of Open Access Journals (Sweden)

    Amir Mohamed Talib

    2018-01-01

    Full Text Available This paper describes a measurement model that is used to measure the student performance in the final examination of Information Technology (IT Fundamentals (IT280 course in the Information Technology (IT Department, College of Computer & Information Sciences (CCIS, Al-Imam Mohammad Ibn Saud Islamic University (IMSIU. The assessment model is developed based on students’ mark entries of final exam results for the second year IT students, which are compiled and tabulated for evaluation using Rasch Measurement Model, and it can be used to measure the students’ performance towards the final examination of the course. A study on 150 second year students (male = 52; female = 98 was conducted to measure students’ knowledge and understanding for IT280 course according to the three level of Bloom’s Taxonomy. The results concluded that students can be categorized as poor (10%, moderate (42%, good (18%, and successful (24% to achieve Level 3 of Bloom’s Taxonomy. This study shows that the students’ performance for the set of IT280 final exam questions was comparatively good. The result generated from this study can be used to guide us to determine the appropriate improvement of teaching method and the quality of question prepared.

  6. Assessment of performance and utility of mortality prediction models in a single Indian mixed tertiary intensive care unit.

    Science.gov (United States)

    Sathe, Prachee M; Bapat, Sharda N

    2014-01-01

    To assess the performance and utility of two mortality prediction models viz. Acute Physiology and Chronic Health Evaluation II (APACHE II) and Simplified Acute Physiology Score II (SAPS II) in a single Indian mixed tertiary intensive care unit (ICU). Secondary objectives were bench-marking and setting a base line for research. In this observational cohort, data needed for calculation of both scores were prospectively collected for all consecutive admissions to 28-bedded ICU in the year 2011. After excluding readmissions, discharges within 24 h and age predicted mortality had strong association with true mortality (R (2) = 0.98 for APACHE II and R (2) = 0.99 for SAPS II). Both models performed poorly in formal Hosmer-Lemeshow goodness-of-fit testing (Chi-square = 12.8 (P = 0.03) for APACHE II, Chi-square = 26.6 (P = 0.001) for SAPS II) but showed good discrimination (area under receiver operating characteristic curve 0.86 ± 0.013 SE (P care and comparing performances of different units without customization. Considering comparable performance and simplicity of use, efforts should be made to adapt SAPS II.

  7. MODELING THE DETERMINANTS OF EXPORTS AND IMPORTS: ASSESSMENT OF THE MACEDONIAN COMPETITIVE PERFORMANCES

    Directory of Open Access Journals (Sweden)

    Goce PETRESKI

    2009-01-01

    Full Text Available So far Macedonia has undergone an unsuccessful attempt to transition,distinguished by low growth rates, high unemployment, extensive poverty,balance of payments unfavorable position, technological lag etc. The externalsector, as a core element to growth perspectives of a small open economy iscritically dependant upon the export competitiveness. Consequently, thispaper will address some critical points of the Macedonian economy,particularly the vulnerability of the external sector alongside with the priceand trade liberalization. The set of analyses is to be carried out to explore theforeign trade structure, current account developments, as well as the majoraspects of qualitative competitiveness. In addition, we have examined theimpact of macroeconomic variables on exports and imports within theselected timeframe. We have therefore applied a comprehensive approach ofdynamic modeling based upon a vector - autoregression model determinedto control for endogeneity and set to estimate the long - run equilibriumrelations, as well as the short-run dynamics of the key variables.

  8. Assessing the Accuracy and Performance of Implicit Solvent Models for Drug Molecules: Conformational Ensemble Approaches

    Czech Academy of Sciences Publication Activity Database

    Kolář, Michal; Fanfrlík, Jindřich; Lepšík, Martin; Forti, F.; Luque, F. J.; Hobza, Pavel

    2013-01-01

    Roč. 117, č. 19 (2013), s. 5950-5962 ISSN 1520-6106 R&D Projects: GA ČR GBP208/12/G016 Grant - others:Operational Program Research and Development for Innovations(XE) CZ 1.05/2.1.00/03/0058 Institutional support: RVO:61388963 Keywords : continuum solvation models * free-energy perturbation * partition-coefficients * HIV1-protease Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.377, year: 2013

  9. Assessing the performance of variational methods for mixed logistic regression models

    Czech Academy of Sciences Publication Activity Database

    Rijmen, F.; Vomlel, Jiří

    2008-01-01

    Roč. 78, č. 8 (2008), s. 765-779 ISSN 0094-9655 R&D Projects: GA MŠk 1M0572 Grant - others:GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : Mixed models * Logistic regression * Variational methods * Lower bound approximation Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.353, year: 2008

  10. A unified model for energy and environmental performance assessment of natural gas-fueled poly-generation systems

    International Nuclear Information System (INIS)

    Chicco, Gianfranco; Mancarella, Pierluigi

    2008-01-01

    Poly-generation systems for combined production of manifold energy vectors such as electricity, heat at different enthalpy levels (for instance, in the form of hot water and steam), and cooling power from a unique source of primary energy (typically natural gas) are increasingly spreading, above all on a small-scale basis (below 1 MW e ), owing to their enhanced energy, environmental and economic characteristics. Availability of suitable tools for assessing the performance of such systems is therefore fundamental. In this paper, a unified general model is proposed for assessing the energy and CO 2 emission performance of any type of poly-generation system with natural gas as the energy input. In particular, the classical energy saving model for cogeneration systems is extended to include in the analysis further energy vectors by defining the novel PPES (Poly-generation Primary Energy Saving) indicator. In addition, equivalent efficiencies for CO 2 emission assessment are defined and used in the formulation of the new PCO2ER (Poly-generation CO 2 Emission Reduction) indicator, specifically introduced for environmental analysis. The formal analogy between the PPES and the PCO2ER indicators is highlighted. Numerical applications are provided to show the effectiveness of the proposed models and to quantify the typical benefits that poly-generation systems can bring. In particular, the new indicators are of relevant interest for both energy planners and policy makers, above all in the outlook of formulating financial incentive strategies, as it already occurs for cogeneration systems, or of participating to specific energy-related markets such as the ones for trading white certificates or emission allowances

  11. Management of the Area 5 Radioactive Waste Management Site using Decision-based, Probabilistic Performance Assessment Modeling

    International Nuclear Information System (INIS)

    Carilli, J.; Crowe, B.; Black, P.; Tauxe, J.; Stockton, T.; Catlett, K.; Yucel, V.

    2003-01-01

    Low-level radioactive waste from cleanup activities at the Nevada Test Site and from multiple sites across the U.S. Department of Energy (DOE) complex is disposed at two active Radioactive Waste Management Sites (RWMS) on the Nevada Test Site. These facilities, which are managed by the DOE National Nuclear Security Administration Nevada Site Office, were recently designated as one of two regional disposal centers and yearly volumes of disposed waste now exceed 50,000 m3 (> 2 million ft3). To safely and cost-effectively manage the disposal facilities, the Waste Management Division of Environmental Management has implemented decision-based management practices using flexible and problem-oriented probabilistic performance assessment modeling. Deterministic performance assessments and composite analyses were completed originally for the Area 5 and Area 3 RWMSs located in, respectively, Frenchman Flat and Yucca Flat on the Nevada Test Site. These documents provide the technical bases for issuance of disposal authorization statements for continuing operation of the disposal facilities. Both facilities are now in a maintenance phase that requires testing of conceptual models, reduction of uncertainty, and site monitoring all leading to eventual closure of the facilities and transition to long-term stewardship

  12. Assessing Organizational Performance

    International Development Research Centre (IDRC) Digital Library (Canada)

    Carroll Salomon

    He is recognized for his expertise in the areas of organisational theory, development, assessment ... Background. Several years ago the International Development Research Centre (IDRC) and Universalia Management ... understood as its structure, governance, leadership, strategic plans and niche management. Human.

  13. Preliminary melter performance assessment report

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, M.L.; Eyler, L.L.; Mahoney, L.A.; Cooper, M.F.; Whitney, L.D.; Shafer, P.J.

    1994-08-01

    The Melter Performance Assessment activity, a component of the Pacific Northwest Laboratory`s (PNL) Vitrification Technology Development (PVTD) effort, was designed to determine the impact of noble metals on the operational life of the reference Hanford Waste Vitrification Plant (HWVP) melter. The melter performance assessment consisted of several activities, including a literature review of all work done with noble metals in glass, gradient furnace testing to study the behavior of noble metals during the melting process, research-scale and engineering-scale melter testing to evaluate effects of noble metals on melter operation, and computer modeling that used the experimental data to predict effects of noble metals on the full-scale melter. Feed used in these tests simulated neutralized current acid waste (NCAW) feed. This report summarizes the results of the melter performance assessment and predicts the lifetime of the HWVP melter. It should be noted that this work was conducted before the recent Tri-Party Agreement changes, so the reference melter referred to here is the Defense Waste Processing Facility (DWPF) melter design.

  14. OLEM Performance Assessment Information

    Data.gov (United States)

    U.S. Environmental Protection Agency — This asset includes a variety of data sets that measure the performance of Office of Land and Emergency Management (OLEM) programs in support of the Office of the...

  15. Performance Assessment Institute-NV

    Energy Technology Data Exchange (ETDEWEB)

    Lombardo, Joesph [Univ. of Nevada, Las Vegas, NV (United States)

    2012-12-31

    The National Supercomputing Center for Energy and the Environment’s intention is to purchase a multi-purpose computer cluster in support of the Performance Assessment Institute (PA Institute). The PA Institute will serve as a research consortium located in Las Vegas Nevada with membership that includes: national laboratories, universities, industry partners, and domestic and international governments. This center will provide a one-of-a-kind centralized facility for the accumulation of information for use by Institutions of Higher Learning, the U.S. Government, and Regulatory Agencies and approved users. This initiative will enhance and extend High Performance Computing (HPC) resources in Nevada to support critical national and international needs in "scientific confirmation". The PA Institute will be promoted as the leading Modeling, Learning and Research Center worldwide. The program proposes to utilize the existing supercomputing capabilities and alliances of the University of Nevada Las Vegas as a base, and to extend these resource and capabilities through a collaborative relationship with its membership. The PA Institute will provide an academic setting for interactive sharing, learning, mentoring and monitoring of multi-disciplinary performance assessment and performance confirmation information. The role of the PA Institute is to facilitate research, knowledge-increase, and knowledge-sharing among users.

  16. Performance Assessment Transport Modeling of Uranium at the Area 5 Radioactive Waste Management Site at the Nevada National Security Site

    International Nuclear Information System (INIS)

    2010-01-01

    Following is a brief summary of the assumptions that are pertinent to the radioactive isotope transport in the GoldSim Performance Assessment model of the Area 5 Radioactive Waste Management Site, with special emphasis on the water-phase reactive transport of uranium, which includes depleted uranium products. The Area 5 PA model assumes activity disposed in trenches is well mixed within the native alluvium of the trench at the time the facility is closed. Waste containers and waste forms are assumed not to limit the release of radionuclides for transport. In the Area 5 RWMS PA model, the pathways that are considered to bring radioactivity in the waste zone to the surface soils of the closure covers are (1) plant uptake, (2) burrowing animal activity, and (3) advection/dispersion/diffusion in the pore water. Water-phase transport is a minor component of the transport, which is dominated by plant uptake and burrowing animal activity. Because the soil column is mostly dry, upward water flux rates are extremely small, resulting in small advective/dispersive transport of radioactive isotopes in pore water of the unsaturated zone. Reactive transport of radioactive elements in the Area 5 soil pore water are modeled using element-specific partition coefficients (Kds) that partition radioactivity between pore water and soil of the disposal cell, and solubility limits that control the solubility of elements in pore water. Geochemical modeling is not performed in the Area 5 RWMS GoldSim PA model; however, Kds and solubility limits were derived from previous geochemical modeling performed using Area 5 geochemical data. Kds for uranium were developed based on geochemical modeling using the mineral characteristics of soil (alluvium) and the chemical characteristics of water at the site (Carle et al., 2002). In the GoldSim model, uranium Kd is represented with a lognormal distribution with a mean value of 0.8 milliliter per gram (taken from Figure 4.11, Page 4-19 of Carle et al

  17. The role of a detailed aqueous phase source release model in the LANL area G performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Vold, E.L.; Shuman, R.; Hollis, D.K. [Los Alamos National Lab., NM (United States)] [and others

    1995-12-31

    A preliminary draft of the Performance Assessment for the Los Alamos National Laboratory (LANL) low-level radioactive waste disposal facility at Area G is currently being completed as required by Department of Energy orders. A detailed review of the inventory data base records and the existing models for source release led to the development of a new modeling capability to describe the liquid phase transport from the waste package volumes. Nuclide quantities are sorted down to four waste package release categories for modeling: rapid release, soil, concrete/sludge, and corrosion. Geochemistry for the waste packages was evaluated in terms of the equilibrium coefficients, Kds, and elemental solubility limits, Csl, interpolated from the literature. Percolation calculations for the base case closure cover show a highly skewed distribution with an average of 4 mm/yr percolation from the disposal unit bottom. The waste release model is based on a compartment representation of the package efflux, and depends on package size, percolation rate or Darcy flux, retardation coefficient, and moisture content.

  18. Technical Approach for Determining Key Parameters Needed for Modeling the Performance of Cast Stone for the Integrated Disposal Facility Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Yabusaki, Steven B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Serne, R. Jeffrey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rockhold, Mark L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Guohui [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Westsik, Joseph H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-30

    Washington River Protection Solutions (WRPS) and its contractors at Pacific Northwest National Laboratory (PNNL) and Savannah River National Laboratory (SRNL) are conducting a development program to develop / refine the cementitious waste form for the wastes treated at the ETF and to provide the data needed to support the IDF PA. This technical approach document is intended to provide guidance to the cementitious waste form development program with respect to the waste form characterization and testing information needed to support the IDF PA. At the time of the preparation of this technical approach document, the IDF PA effort is just getting started and the approach to analyze the performance of the cementitious waste form has not been determined. Therefore, this document looks at a number of different approaches for evaluating the waste form performance and describes the testing needed to provide data for each approach. Though the approach addresses a cementitious secondary aqueous waste form, it is applicable to other waste forms such as Cast Stone for supplemental immobilization of Hanford LAW. The performance of Cast Stone as a physical and chemical barrier to the release of contaminants of concern (COCs) from solidification of Hanford liquid low activity waste (LAW) and secondary wastes processed through the Effluent Treatment Facility (ETF) is of critical importance to the Hanford Integrated Disposal Facility (IDF) total system performance assessment (TSPA). The effectiveness of cementitious waste forms as a barrier to COC release is expected to evolve with time. PA modeling must therefore anticipate and address processes, properties, and conditions that alter the physical and chemical controls on COC transport in the cementitious waste forms over time. Most organizations responsible for disposal facility operation and their regulators support an iterative hierarchical safety/performance assessment approach with a general philosophy that modeling provides

  19. Modeling Np and Pu transport with a surface complexation model and spatially variant sorption capacities: Implications for reactive transport modeling and performance assessments of nuclear waste disposal sites

    Science.gov (United States)

    Glynn, P.D.

    2003-01-01

    simulation conditions. Functional behaviors that cannot be fit include concentration trend reversals and radionuclide desorption spikes. Other simulation results are fit successfully but the fitted parameters (Kd and dispersivity) vary significantly depending on simulation conditions (e.g. "infiltration" vs. "cleanup" conditions). Notably, an increase in the variance of the specified sorption capacities results in a marked increase in the dispersion of the radionuclides. The results presented have implications for the simulation of radionuclide migration in performance assessments of nuclear waste-disposal sites, for the future monitoring of those sites, and more generally for modeling contaminant transport in ground-water environments. ?? 2003 Published by Elsevier Science Ltd.

  20. The role of a detailed aqueous phase source release model in the LANL Area G performance assessment

    International Nuclear Information System (INIS)

    Vold, E.L.; Hollis, D.; Longmire, P.; Springer, E.; Birdsell, K.; Shuman, R.

    1996-01-01

    The Performance Assessment for the LANL Low-Level Radioactive Waste (LLRW) Disposal Facility, Area G, is on-going. A detailed review of the inventory data base records and the existing models for source release led to the development of a new modeling capability to describe the liquid phase aqueous transport from the waste package volumes. Inventory is sorted into four release form categories and screened in a comparison of leachate concentrations to the drinking water limit. Percolation through the disposal unit is prescribed in an independent surface water balance model incorporating site rainfall statistics. Waste package types and the disposal unit matrix have independently specified solubility limits and solid-liquid phase partition coefficients, or Kd values. Analytic solutions for inventory limited release of each nuclide in each of the four different waste package release forms are computed. Isotopic contributions are summed over elements to limit the waste package liquid phase concentrations to the elemental solubility limits. Time dependent releases from the waste packages for each nuclide which may be inventory or solubility limited are specified as model output which is provided as the source term to the unsaturated transport model. The waste package efflux is distributed over the 2-D unsaturated zone model grid points corresponding to the cross-sections for 5 representative disposal units within the mesa top. Results show the Area G release is dominated by the inventory in the rapid release waste form (Kd = 0), which percolates from the waste packages over 5--100 years and from the disposal unit over 50--1,000 years. Nuclides in waste package categories with larger Kd values are released proportionately slower. U and Th are the main nuclides of concern released as solubility limited nuclides from the historical inventory at Area G

  1. Introduction to radiological performance assessment

    International Nuclear Information System (INIS)

    Moss, G.

    1995-02-01

    A radiological performance assessment is conducted to provide reasonable assurance that performance objectives for low-level radioactive waste (LLW) disposal will be met. Beginning in the early stages of development, a radiological performance assessment continues through the operational phase, and is instrumental in the postclosure of the facility. Fundamental differences exist in the regulation of commercial and defense LLW, but the radiological performance assessment process is essentially the same for both. The purpose of this document is to describe that process in a concise and straightforward manner. This document focuses on radiological performance assessment as it pertains to commercial LLW disposal, but is applicable to US Department of Energy sites as well. Included are discussions on performance objectives, site characterization, and how a performance assessment is conducted. A case study is used to illustrate how the process works as a whole. A bibliography is provided to assist in locating additional information

  2. Review and perspectives on spallings release models in the 1996 performance assessment for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Knowles, M.K.; Hansen, F.D.; Thompson, T.W.; Schatz, J.F.; Gross, M.

    2000-01-01

    The Waste Isolation Pilot Plant was licensed for disposal of transuranic wastes generated by the US Department of Energy. The facility consists of a repository mined in a bedded salt formation, approximately 650 m below the surface. Regulations promulgated by the US Environmental Protection Agency require that performance assessment calculations for the repository include the possibility that an exploratory drilling operation could penetrate the waste disposal areas at some time in the future. Release of contaminated solids could reach the surface during a drilling intrusion. One of the mechanisms for release, known as spallings, can occur if gas pressures in the repository exceed the hydrostatic pressure of a column of drilling mud. Calculation of solids releases for spallings depends critically on the conceptual models for the waste, for the spallings process, and assumptions regarding driller parameters and practices. This paper presents a review of the evolution of these models during the regulatory review of the Compliance Certification Application for the repository. A summary and perspectives on the implementation of conservative assumptions in model development are also provided

  3. Review and perspectives on spallings release models in the 1996 performance assessment for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Knowles, M.K; Hansen, F.D.; Thompson, T.W.; Schatz, J.F.; Gross, M.

    2000-01-01

    The Waste Isolation Pilot Plant was licensed for disposal of transuranic wastes generated by the US Department of Energy. The facility consists of a repository mined in a bedded salt formation, approximately 650 m below the surface. Regulations promulgated by the US Environmental Protection Agency require that performance assessment calculations for the repository include the possibility that an exploratory drilling operation could penetrate the waste disposal areas at some time in the future. Release of contaminated solids could reach the surface during a drilling intrusion. One of the mechanisms for release, known as spallings, can occur if gas pressures in the repository exceed the hydrostatic pressure of a column of drilling mud. Calculation of solids releases for spallings depends critically on the conceptual models for the waste, for the spallings process, and assumptions regarding driller parameters and practices. The paper presents a review of the evolution of these models during regulatory review of the Compliance Certification Application for the repository. A summary and perspectives on the implementation of conservative assumptions in model development are also provided

  4. Operational human performance reliability assessment (OHPRA)

    International Nuclear Information System (INIS)

    Haas, P.M.; Swanson, P.J.; Connelly, E.M.

    1993-01-01

    Operational Human Performance Reliability Assessment (OHPRA) is an approach for assessing human performance that is being developed in response to demands from modern process industries for practical and effective tools to assess and improve human performance, and therefore overall system performance and safety. The single most distinguishing feature of the approach is that is defines human performance in open-quotes operationalclose quotes terms. OHPRA is focused not on generation of human error probabilities, but on practical analysis of human performance to aid management in (1) identifying open-quotes fixableclose quotes problems and (2) providing input on the importance and nature of potential improvements. Development of the model in progress uses a unique approach for eliciting expert strategies for assessing performance. A PC-based model incorporating this expertise is planned. A preliminary version of the approach has already been used successfully to identify practical human performance problems in reactor and chemical process plant operations

  5. Technology Performance Level Assessment Methodology.

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Jesse D.; Bull, Diana L; Malins, Robert Joseph; Costello, Ronan Patrick; Aurelien Babarit; Kim Nielsen; Claudio Bittencourt Ferreira; Ben Kennedy; Kathryn Dykes; Jochem Weber

    2017-04-01

    The technology performance level (TPL) assessments can be applied at all technology development stages and associated technology readiness levels (TRLs). Even, and particularly, at low TRLs the TPL assessment is very effective as it, holistically, considers a wide range of WEC attributes that determine the techno-economic performance potential of the WEC farm when fully developed for commercial operation. The TPL assessment also highlights potential showstoppers at the earliest possible stage of the WEC technology development. Hence, the TPL assessment identifies the technology independent “performance requirements.” In order to achieve a successful solution, the entirety of the performance requirements within the TPL must be considered because, in the end, all the stakeholder needs must be achieved. The basis for performing a TPL assessment comes from the information provided in a dedicated format, the Technical Submission Form (TSF). The TSF requests information from the WEC developer that is required to answer the questions posed in the TPL assessment document.

  6. Effect of changes over time in the performance of a customized SAPS-II model on the quality of care assessment

    NARCIS (Netherlands)

    Minne, Lilian; Eslami, Saeid; de Keizer, Nicolette; de Jonge, Evert; de Rooij, Sophia E.; Abu-Hanna, Ameen

    2012-01-01

    Purpose: The aim of our study was to explore, using an innovative method, the effect of temporal changes in the mortality prediction performance of an existing model on the quality of care assessment. The prognostic model (rSAPS-II) was a recalibrated Simplified Acute Physiology Score-II model

  7. Aggregating validity indicators: The salience of domain specificity and the indeterminate range in multivariate models of performance validity assessment.

    Science.gov (United States)

    Erdodi, Laszlo A

    2017-11-07

    This study was designed to examine the "domain specificity" hypothesis in performance validity tests (PVTs) and the epistemological status of an "indeterminate range" when evaluating the credibility of a neuropsychological profile using a multivariate model of performance validity assessment. While previous research suggests that aggregating PVTs produces superior classification accuracy compared to individual instruments, the effect of the congruence between the criterion and predictor variable on signal detection and the issue of classifying borderline cases remain understudied. Data from a mixed clinical sample of 234 adults referred for cognitive evaluation (M Age  = 46.6; M Education  = 13.5) were collected. Two validity composites were created: one based on five verbal PVTs (EI-5 VER ) and one based on five nonverbal PVTs (EI-5 NV ) and compared against several other PVTs. Overall, language-based tests of cognitive ability were more sensitive to elevations on the EI-5 VER compared to visual-perceptual tests; whereas, the opposite was observed with the EI-5 NV . However, the match between predictor and criterion variable had a more complex relationship with classification accuracy, suggesting the confluence of multiple factors (sensory modality, cognitive domain, testing paradigm). An "indeterminate range" of performance validity emerged that was distinctly different from both the Pass and the Fail group. Trichotomized criterion PVTs (Pass-Borderline-Fail) had a negative linear relationship with performance on tests of cognitive ability, providing further support for an "in-between" category separating the unequivocal Pass and unequivocal Fail classification range. The choice of criterion variable can influence classification accuracy in PVT research. Establishing a Borderline range between Pass and Fail more accurately reflected the distribution of scores on multiple PVTs. The traditional binary classification system imposes an artificial dichotomy on

  8. Model Performance Evaluation and Scenario Analysis (MPESA)

    Science.gov (United States)

    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)

  9. Quality assurance in performance assessments

    Energy Technology Data Exchange (ETDEWEB)

    Maul, P.R.; Watkins, B.M.; Salter, P.; Mcleod, R [QuantiSci Ltd, Henley-on-Thames (United Kingdom)

    1999-01-01

    Following publication of the Site-94 report, SKI wishes to review how Quality Assurance (QA) issues could be treated in future work both in undertaking their own Performance Assessment (PA) calculations and in scrutinising documents supplied by SKB (on planning a repository for spent fuels in Sweden). The aim of this report is to identify the key QA issues and to outline the nature and content of a QA plan which would be suitable for SKI, bearing in mind the requirements and recommendations of relevant standards. Emphasis is on issues which are specific to Performance Assessments for deep repositories for radioactive wastes, but consideration is also given to issues which need to be addressed in all large projects. Given the long time over which the performance of a deep repository system must be evaluated, the demonstration that a repository is likely to perform satisfactorily relies on the use of computer-generated model predictions of system performance. This raises particular QA issues which are generally not encountered in other technical areas (for instance, power station operations). The traceability of the arguments used is a key QA issue, as are conceptual model uncertainty, and code verification and validation; these were all included in the consideration of overall uncertainties in the Site-94 project. Additionally, issues which are particularly relevant to SKI include: How QA in a PA fits in with the general QA procedures of the organisation undertaking the work. The relationship between QA as applied by the regulator and the implementor of a repository development programme. Section 2 introduces the discussion of these issues by reviewing the standards and guidance which are available from national and international organisations. This is followed in Section 3 by a review of specific issues which arise from the Site-94 exercise. An outline procedure for managing QA issues in SKI is put forward as a basis for discussion in Section 4. It is hoped that

  10. Quality assurance in performance assessments

    International Nuclear Information System (INIS)

    Maul, P.R.; Watkins, B.M.; Salter, P.; Mcleod, R

    1999-01-01

    Following publication of the Site-94 report, SKI wishes to review how Quality Assurance (QA) issues could be treated in future work both in undertaking their own Performance Assessment (PA) calculations and in scrutinising documents supplied by SKB (on planning a repository for spent fuels in Sweden). The aim of this report is to identify the key QA issues and to outline the nature and content of a QA plan which would be suitable for SKI, bearing in mind the requirements and recommendations of relevant standards. Emphasis is on issues which are specific to Performance Assessments for deep repositories for radioactive wastes, but consideration is also given to issues which need to be addressed in all large projects. Given the long time over which the performance of a deep repository system must be evaluated, the demonstration that a repository is likely to perform satisfactorily relies on the use of computer-generated model predictions of system performance. This raises particular QA issues which are generally not encountered in other technical areas (for instance, power station operations). The traceability of the arguments used is a key QA issue, as are conceptual model uncertainty, and code verification and validation; these were all included in the consideration of overall uncertainties in the Site-94 project. Additionally, issues which are particularly relevant to SKI include: How QA in a PA fits in with the general QA procedures of the organisation undertaking the work. The relationship between QA as applied by the regulator and the implementor of a repository development programme. Section 2 introduces the discussion of these issues by reviewing the standards and guidance which are available from national and international organisations. This is followed in Section 3 by a review of specific issues which arise from the Site-94 exercise. An outline procedure for managing QA issues in SKI is put forward as a basis for discussion in Section 4. It is hoped that

  11. Comparative performance of diabetes-specific and general population-based cardiovascular risk assessment models in people with diabetes mellitus.

    Science.gov (United States)

    Echouffo-Tcheugui, J-B; Kengne, A P

    2013-10-01

    Multivariable models for estimating cardiovascular disease (CVD) risk in people with diabetes comprise general population-based models and those from diabetic cohorts. Whether one set of models should receive preference is unclear. We evaluated the evidence on direct comparisons of the performance of general population vs diabetes-specific CVD risk models in people with diabetes. MEDLINE and EMBASE databases were searched up to March 2013. Two reviewers independently identified studies that compared the performance of general CVD models vs diabetes-specific ones in the same group of people with diabetes. Independent, dual data extraction on study design, risk models, outcomes; and measures of performance was conducted. Eleven articles reporting on 22 pair wise comparisons of a diabetes-specific model (UKPDS, ADVANCE and DCS risk models) to a general population model (three variants of the Framingham model, Prospective Cardiovascular Münster [PROCAM] score, CardioRisk Manager [CRM], Joint British Societies Coronary Risk Chart [JBSRC], Progetto Cuore algorithm and the CHD-Riskard algorithm) were eligible. Absolute differences in C-statistic of diabetes-specific vs general population-based models varied from -0.13 to 0.09. Comparisons for other performance measures were unusual. Outcomes definitions were congruent with those applied during model development. In 14 comparisons, the UKPDS, ADVANCE or DCS diabetes-specific models were superior to the general population CVD risk models. Authors reported better C-statistic for models they developed. The limited existing evidence suggests a possible discriminatory advantage of diabetes-specific over general population-based models for CVD risk stratification in diabetes. More robust head-to-head comparisons are needed to confirm this trend and strengthen recommendations. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  12. An Examination of Pennsylvania's Classroom Diagnostic Testing as a Predictive Model of Pennsylvania System of School Assessment Performance

    Science.gov (United States)

    Matsanka, Christopher

    2017-01-01

    The purpose of this non-experimental quantitative study was to investigate the relationship between Pennsylvania's Classroom Diagnostic Tools (CDT) interim assessments and the state-mandated Pennsylvania System of School Assessment (PSSA) and to create linear regression equations that could be used as models to predict student performance on the…

  13. Performance assessment of geospatial simulation models of land-use change--a landscape metric-based approach.

    Science.gov (United States)

    Sakieh, Yousef; Salmanmahiny, Abdolrassoul

    2016-03-01

    Performance evaluation is a critical step when developing land-use and cover change (LUCC) models. The present study proposes a spatially explicit model performance evaluation method, adopting a landscape metric-based approach. To quantify GEOMOD model performance, a set of composition- and configuration-based landscape metrics including number of patches, edge density, mean Euclidean nearest neighbor distance, largest patch index, class area, landscape shape index, and splitting index were employed. The model takes advantage of three decision rules including neighborhood effect, persistence of change direction, and urbanization suitability values. According to the results, while class area, largest patch index, and splitting indices demonstrated insignificant differences between spatial pattern of ground truth and simulated layers, there was a considerable inconsistency between simulation results and real dataset in terms of the remaining metrics. Specifically, simulation outputs were simplistic and the model tended to underestimate number of developed patches by producing a more compact landscape. Landscape-metric-based performance evaluation produces more detailed information (compared to conventional indices such as the Kappa index and overall accuracy) on the model's behavior in replicating spatial heterogeneity features of a landscape such as frequency, fragmentation, isolation, and density. Finally, as the main characteristic of the proposed method, landscape metrics employ the maximum potential of observed and simulated layers for a performance evaluation procedure, provide a basis for more robust interpretation of a calibration process, and also deepen modeler insight into the main strengths and pitfalls of a specific land-use change model when simulating a spatiotemporal phenomenon.

  14. Performance Assessment National Review Group

    International Nuclear Information System (INIS)

    Lieberman, J.A.; Davis, S.N.; Harleman, D.R.F.

    1985-02-01

    Performance assessment involves predicting the potential radiological impact of a nuclear waste disposal system, taking into account all of the natural and engineered components of the system. It includes the analysis and evaluation of predicted system and component performance to determine compliance with regulatory performance criteria. In the context of the nuclear waste management program, performance assessment has five major purposes: to assist in the evaluation and selection of repository sites; to guide the research, development, and testing programs; to assist in the evaluation of repository designs; to assist in the evaluation of the design and performance of engineered barriers; and to show regulatory compliance and support repository licensing. Current performance assessment methodologies are still in the developmental stage. Only the simplest of bounding calculations have produced quantitative predictions of radionuclide releases. The methodologies require considerable extension and validation before they can provide answers suitable for project decisions and licensing. 135 refs., 9 figs., 1 tab

  15. Multiprocessor performance modeling with ADAS

    Science.gov (United States)

    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.

  16. Comparing Cognitive Models of Domain Mastery and Task Performance in Algebra: Validity Evidence for a State Assessment

    Science.gov (United States)

    Warner, Zachary B.

    2013-01-01

    This study compared an expert-based cognitive model of domain mastery with student-based cognitive models of task performance for Integrated Algebra. Interpretations of student test results are limited by experts' hypotheses of how students interact with the items. In reality, the cognitive processes that students use to solve each item may be…

  17. The international intraval project to study validation of geosphere transport models for performance assessment of nuclear waste disposal

    International Nuclear Information System (INIS)

    1990-01-01

    INTRAVAL is an international project concerned with the use of mathematical models for predicting the potential transport of radioactive substances in the geosphere. Such models are used to help assess the longterm safety of radioactive waste disposal systems. The INTRAVAL project was established to evaluate the validity of these models. Results from a set of selected laboratory and field experiments as well as studies of occurrences of radioactive substances in nature (natural analogues) are compared in a systematic way with model predictions. Discrepancies between observations and predictions are discussed and analyzed

  18. Well performance model

    International Nuclear Information System (INIS)

    Thomas, L.K.; Evans, C.E.; Pierson, R.G.; Scott, S.L.

    1992-01-01

    This paper describes the development and application of a comprehensive oil or gas well performance model. The model contains six distinct sections: stimulation design, tubing and/or casing flow, reservoir and near-wellbore calculations, production forecasting, wellbore heat transmission, and economics. These calculations may be performed separately or in an integrated fashion with data and results shared among the different sections. The model analysis allows evaluation of all aspects of well completion design, including the effects on future production and overall well economics

  19. Groundwater age and lifetime expectancy modelling approach for site characterization and performance assessment of radwaste repository in clay formation

    International Nuclear Information System (INIS)

    Cornaton, F.; Perrochet, P.; Benabderrahmane, H.

    2010-01-01

    variables that are combined and used to assess the repository performance regarding its emplacement in the transposition zone. Age and lifetime expectancy distributions are solved considering advection and dispersion/diffusion processes according to the approach proposed by Cornaton and Perrochet (2006). Advective-dispersive age solutions are compared to available age dates of pore water within the two main calcareous aquifers (Dogger and Oxfordian) that embed the Callovo-Oxfordian host formation. Such a comparison is helpful for the consolidation of the flow calibration, the estimation of the transport porosity field (since porosity is age generator) and for analyzing the internal water mixing processes and hydraulic behavior of major faults. Lifetime expectancy solutions are used to predict the response at the biosphere resulting from contaminant mass input occurring at a series of hypothetical repository locations. Lifetime expectancy solutions combined with age solutions provide the distribution of total residence times within the domain (i.e the total time required to travel from recharge to discharge). The latter is used to map in the 3-D space the low- and high-speed flow zones at the local scale. Finally, the behavior of age solutions is investigated when the hydraulic regime is rendered transient in response to the climatic evolution during the past Million years and to the climatic projection for the coming Million years. Transient age solutions at actual time are useful to analyze the effect of the temporal flow regime variations on the measured age dates and on ages simulated under steady-flow conditions. (authors)

  20. NIF capsule performance modeling

    Directory of Open Access Journals (Sweden)

    Weber S.

    2013-11-01

    Full Text Available Post-shot modeling of NIF capsule implosions was performed in order to validate our physical and numerical models. Cryogenic layered target implosions and experiments with surrogate targets produce an abundance of capsule performance data including implosion velocity, remaining ablator mass, times of peak x-ray and neutron emission, core image size, core symmetry, neutron yield, and x-ray spectra. We have attempted to match the integrated data set with capsule-only simulations by adjusting the drive and other physics parameters within expected uncertainties. The simulations include interface roughness, time-dependent symmetry, and a model of mix. We were able to match many of the measured performance parameters for a selection of shots.

  1. Assessing the 20th century performance of global climate models and application to climate change adaptation planning

    Science.gov (United States)

    Geil, Kerrie

    Rapid environmental changes linked to human-induced increases in atmospheric greenhouse gas concentrations have been observed on a global scale over recent decades. Given the relative certainty of continued change across many earth systems, the information output from climate models is an essential resource for adaptation planning. But in the face of many known modeling deficiencies, how confident can we be in model projections of future climate? It stands to reason that a realistic simulation of the present climate is at least a necessary (but likely not sufficient) requirement for a model's ability to realistically simulate the climate of the future. Here, I present the results of three studies that evaluate the 20th century performance of global climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5). (Abstract shortened by ProQuest.).

  2. DOE site performance assessment activities

    International Nuclear Information System (INIS)

    1990-07-01

    Information on performance assessment capabilities and activities was collected from eight DOE sites. All eight sites either currently dispose of low-level radioactive waste (LLW) or plan to dispose of LLW in the near future. A survey questionnaire was developed and sent to key individuals involved in DOE Order 5820.2A performance assessment activities at each site. The sites surveyed included: Hanford Site (Hanford), Idaho National Engineering Laboratory (INEL), Los Alamos National Laboratory (LANL), Nevada Test Site (NTS), Oak Ridge National Laboratory (ORNL), Paducah Gaseous Diffusion Plant (Paducah), Portsmouth Gaseous Diffusion Plant (Portsmouth), and Savannah River Site (SRS). The questionnaire addressed all aspects of the performance assessment process; from waste source term to dose conversion factors. This report presents the information developed from the site questionnaire and provides a comparison of site-specific performance assessment approaches, data needs, and ongoing and planned activities. All sites are engaged in completing the radioactive waste disposal facility performance assessment required by DOE Order 5820.2A. Each site has achieved various degrees of progress and have identified a set of critical needs. Within several areas, however, the sites identified common needs and questions

  3. Assessing performance of Bayesian state-space models fit to Argos satellite telemetry locations processed with Kalman filtering.

    Science.gov (United States)

    Silva, Mónica A; Jonsen, Ian; Russell, Deborah J F; Prieto, Rui; Thompson, Dave; Baumgartner, Mark F

    2014-01-01

    Argos recently implemented a new algorithm to calculate locations of satellite-tracked animals that uses a Kalman filter (KF). The KF algorithm is reported to increase the number and accuracy of estimated positions over the traditional Least Squares (LS) algorithm, with potential advantages to the application of state-space methods to model animal movement data. We tested the performance of two Bayesian state-space models (SSMs) fitted to satellite tracking data processed with KF algorithm. Tracks from 7 harbour seals (Phoca vitulina) tagged with ARGOS satellite transmitters equipped with Fastloc GPS loggers were used to calculate the error of locations estimated from SSMs fitted to KF and LS data, by comparing those to "true" GPS locations. Data on 6 fin whales (Balaenoptera physalus) were used to investigate consistency in movement parameters, location and behavioural states estimated by switching state-space models (SSSM) fitted to data derived from KF and LS methods. The model fit to KF locations improved the accuracy of seal trips by 27% over the LS model. 82% of locations predicted from the KF model and 73% of locations from the LS model were Argos data. On average, 88% of whale locations estimated by KF models fell within the 95% probability ellipse of paired locations from LS models. Precision of KF locations for whales was generally higher. Whales' behavioural mode inferred by KF models matched the classification from LS models in 94% of the cases. State-space models fit to KF data can improve spatial accuracy of location estimates over LS models and produce equally reliable behavioural estimates.

  4. Performance assessment - risk assessment vive la differences

    International Nuclear Information System (INIS)

    Nitschke, R.L.

    1997-01-01

    In the sister worlds of radioactive waste management disposal and environmental restoration, there are two similar processes and computational approaches for determining the acceptability of the proposed activities. While similar, these two techniques can lead to confusion and misunderstanding if the differences are not recognized and appreciated. In the case of radioactive waste management, the performance assessment process is used to determine compliance with certain prescribed 'performance objectives'. These objectives are designed to ensure that the disposal of radioactive (high-level, low-level, and/or transuranic) waste will be protective of human health and the environment. The environmental link is primarily through assuring protection of the groundwater as a resource. In the case of environmental restoration, the risk assessment process is used to determine the proper remedial action response, if any, for a past hazardous waste release. The process compares the 'no action' or 'leave as is' option with both carcinogenic and noncarcinogenic values for human health to determine the need for any action and to help to help determine just what the appropriate action would need to be. The impacts to the ecological system are evaluated in a slightly, different but similar fashion. Now the common objectives between these two processes notwithstanding. There are some key and fundamental differences that need to be answered that make direct comparisons or a common approach inappropriate. Failure to recognize this can lead to confusion and misunderstanding. This can be particularly problematic when one is faced with an active disposal facility located within the boundaries of an environmental restoration site as is the case at the Idaho National Engineering Laboratory (INEL). Through a critical evaluation of the performance assessment and risk assessment processes, highlighting both similarities and differences, it is hoped that greater understanding and appreciation

  5. Performance of Models for Flash Flood Warning and Hazard Assessment: The 2015 Kali Gandaki Landslide Dam Breach in Nepal

    Directory of Open Access Journals (Sweden)

    Jeremy D. Bricker

    2017-02-01

    Full Text Available The 2015 magnitude 7.8 Gorkha earthquake and its aftershocks weakened mountain slopes in Nepal. Co- and postseismic landsliding and the formation of landslide-dammed lakes along steeply dissected valleys were widespread, among them a landslide that dammed the Kali Gandaki River. Overtopping of the landslide dam resulted in a flash flood downstream, though casualties were prevented because of timely evacuation of low-lying areas. We hindcast the flood using the BREACH physically based dam-break model for upstream hydrograph generation, and compared the resulting maximum flow rate with those resulting from various empirical formulas and a simplified hydrograph based on published observations. Subsequent modeling of downstream flood propagation was compromised by a coarse-resolution digital elevation model with several artifacts. Thus, we used a digital-elevation-model preprocessing technique that combined carving and smoothing to derive topographic data. We then applied the 1-dimensional HEC-RAS model for downstream flood routing, and compared it to the 2-dimensional Delft-FLOW model. Simulations were validated using rectified frames of a video recorded by a resident during the flood in the village of Beni, allowing estimation of maximum flow depth and speed. Results show that hydrological smoothing is necessary when using coarse topographic data (such as SRTM or ASTER, as using raw topography underestimates flow depth and speed and overestimates flood wave arrival lag time. Results also show that the 2-dimensional model produces more accurate results than the 1-dimensional model but the 1-dimensional model generates a more conservative result and can be run in a much shorter time. Therefore, a 2-dimensional model is recommended for hazard assessment and planning, whereas a 1-dimensional model would facilitate real-time warning declaration.

  6. Assessing the performance of community-available global MHD models using key system parameters and empirical relationships

    Science.gov (United States)

    Gordeev, E.; Sergeev, V.; Honkonen, I.; Kuznetsova, M.; Rastätter, L.; Palmroth, M.; Janhunen, P.; Tóth, G.; Lyon, J.; Wiltberger, M.

    2015-12-01

    Global magnetohydrodynamic (MHD) modeling is a powerful tool in space weather research and predictions. There are several advanced and still developing global MHD (GMHD) models that are publicly available via Community Coordinated Modeling Center's (CCMC) Run on Request system, which allows the users to simulate the magnetospheric response to different solar wind conditions including extraordinary events, like geomagnetic storms. Systematic validation of GMHD models against observations still continues to be a challenge, as well as comparative benchmarking of different models against each other. In this paper we describe and test a new approach in which (i) a set of critical large-scale system parameters is explored/tested, which are produced by (ii) specially designed set of computer runs to simulate realistic statistical distributions of critical solar wind parameters and are compared to (iii) observation-based empirical relationships for these parameters. Being tested in approximately similar conditions (similar inputs, comparable grid resolution, etc.), the four models publicly available at the CCMC predict rather well the absolute values and variations of those key parameters (magnetospheric size, magnetic field, and pressure) which are directly related to the large-scale magnetospheric equilibrium in the outer magnetosphere, for which the MHD is supposed to be a valid approach. At the same time, the models have systematic differences in other parameters, being especially different in predicting the global convection rate, total field-aligned current, and magnetic flux loading into the magnetotail after the north-south interplanetary magnetic field turning. According to validation results, none of the models emerges as an absolute leader. The new approach suggested for the evaluation of the models performance against reality may be used by model users while planning their investigations, as well as by model developers and those interesting to quantitatively

  7. A standardized patient model to teach and assess professionalism and communication skills: the effect of personality type on performance.

    Science.gov (United States)

    Lifchez, Scott D; Redett, Richard J

    2014-01-01

    Teaching and assessing professionalism and interpersonal communication skills can be more difficult for surgical residency programs than teaching medical knowledge or patient care, for which many structured educational curricula and assessment tools exist. Residents often learn these skills indirectly, by observing the behavior of their attendings when communicating with patients and colleagues. The purpose of this study was to assess the results of an educational curriculum we created to teach and assess our residents in professionalism and communication. We assessed resident and faculty prior education in delivering bad news to patients. Residents then participated in a standardized patient (SP) encounter to deliver bad news to a patient's family regarding a severe burn injury. Residents received feedback from the encounter and participated in an education curriculum on communication skills and professionalism. As a part of this curriculum, residents underwent assessment of communication style using the Myers-Briggs type inventory. The residents then participated in a second SP encounter discussing a severe pulmonary embolus with a patient's family. Resident performance on the SP evaluation correlated with an increased comfort in delivering bad news. Comfort in delivering bad news did not correlate with the amount of prior education on the topic for either residents or attendings. Most of our residents demonstrated an intuitive thinking style (NT) on the Myers-Briggs type inventory, very different from population norms. The lack of correlation between comfort in delivering bad news and prior education on the subject may indicate the difficulty in imparting communication and professionalism skills to residents effectively. Understanding communication style differences between our residents and the general population can help us teach professionalism and communication skills more effectively. With the next accreditation system, residency programs would need to

  8. Risk assessment of student performance in the International Foundations of Medicine Clinical Science Examination by the use of statistical modeling.

    Science.gov (United States)

    David, Michael C; Eley, Diann S; Schafer, Jennifer; Davies, Leo

    2016-01-01

    The primary aim of this study was to assess the predictive validity of cumulative grade point average (GPA) for performance in the International Foundations of Medicine (IFOM) Clinical Science Examination (CSE). A secondary aim was to develop a strategy for identifying students at risk of performing poorly in the IFOM CSE as determined by the National Board of Medical Examiners' International Standard of Competence. Final year medical students from an Australian university medical school took the IFOM CSE as a formative assessment. Measures included overall IFOM CSE score as the dependent variable, cumulative GPA as the predictor, and the factors age, gender, year of enrollment, international or domestic status of student, and language spoken at home as covariates. Multivariable linear regression was used to measure predictor and covariate effects. Optimal thresholds of risk assessment were based on receiver-operating characteristic (ROC) curves. Cumulative GPA (nonstandardized regression coefficient [B]: 81.83; 95% confidence interval [CI]: 68.13 to 95.53) and international status (B: -37.40; 95% CI: -57.85 to -16.96) from 427 students were found to be statistically associated with increased IFOM CSE performance. Cumulative GPAs of 5.30 (area under ROC [AROC]: 0.77; 95% CI: 0.72 to 0.82) and 4.90 (AROC: 0.72; 95% CI: 0.66 to 0.78) were identified as being thresholds of significant risk for domestic and international students, respectively. Using cumulative GPA as a predictor of IFOM CSE performance and accommodating for differences in international status, it is possible to identify students who are at risk of failing to satisfy the National Board of Medical Examiners' International Standard of Competence.

  9. Assessment by Finite Element Modeling Indicates That Surgical Intramuscular Aponeurotomy Performed Closer to the Tendon Enhances Intended Acute Effects in Extramuscularly Connected Muscle

    NARCIS (Netherlands)

    Yucesoy, C.A.; Huijing, P.A.J.B.M.

    2009-01-01

    The effects of location of aponeurotomy on the muscular mechanics of extramuscularly connected muscle were assessed. Using finite element modeling, extensor digitorum longus muscle of the rat was studied for the effects of aponeurotomy performed in each of three locations on the proximal

  10. PERFORMANCE ASSESSMENT FOR FIELD SPORTS

    Directory of Open Access Journals (Sweden)

    Christopher Carling

    2009-03-01

    Full Text Available DESCRIPTION The book covers the various sport science assessment procedures for sports such as soccer, rugby, field hockey and lacrosse. It provides detailed and clear information about laboratory and field-based methods that can be used to assess and improve both individual and team performance. PURPOSE The book aims to provide a contemporary reference tool for selection of appropriate testing procedures for sports across a range of scientific disciplines. FEATURES The text begins with a chapter on the rationales for performance assessments, the use of technology and the necessity for procedures to conform to scientific rigor, explaining the importance of test criteria. This chapter ends by emphasizing the importance of the feedback process and vital considerations for the practitioner when interpreting the data, selecting which information is most important and how to deliver this back to the athlete or coach in order to deliver a positive performance outcome. The next two chapters focus on psychological assessments with respect to skill acquisition, retention and execution providing a variety of qualitative and quantitative options, underpinned with scientific theory and contextualized in order to improve the understanding of the application of these methods to improve anticipation and decision-making to enhance game intelligence.Chapter 4 provides coverage of match analysis techniques in order to make assessments of technical, tactical and physical performances. Readers learn about a series of methodologies ranging from simplistic pen and paper options through to sophisticated technological systems with some exemplar data also provided. Chapters 5 through 7 cover the physiological based assessments, including aerobic, anaerobic and anthropometric procedures. Each chapter delivers a theoretical opening section before progressing to various assessment options and the authors make great efforts to relate to sport-specific settings. The final

  11. The International hydrocoin project. Groundwater hydrology modelling strategies for performance assessment of nuclear waste disposal. Summary report

    International Nuclear Information System (INIS)

    1992-01-01

    In 1984 the Swedish Nuclear Power Inspectorate, SKI, initiated the international cooperation project HYDROCOIN for the study of groundwater flow modelling in the context of radioactive waste disposal. The objective of HYDROCOIN was to improve knowledge of the influence of various strategies for groundwater flow modelling for the safety assessment of final repositories for radioactive wastes. The study comprised: the impact on the groundwater flow calculations of different solution algorithms, the capabilities of different models to describe field tests and bench-scale experiments, and the impact on the groundwater flow calculations of incorporating various physical phenomena. The work was conducted at three levels addressing code verification (Level 1), model validation (Level 2), and sensitivity and uncertainty analysis of groundwater flow calculations (Level 3). This report gives an overview and summary of test cases of HYDROCOIN Level 1, the issue of validation groundwater flow models (HYDROCOIN Level 2), the methodologies used in uncertainty and sensitivity analysis (HYDROCOIN Level 3). 108 figs., 24 tabs., 2 appendices

  12. Software Quality Assurance Plan for GoldSim Models Supporting the Area 3 and Area 5 Radioactive Waste Management Site Performance Assessment Program

    International Nuclear Information System (INIS)

    Gregory J. Shott, Vefa Yucel

    2007-01-01

    This Software Quality Assurance Plan (SQAP) applies to the development and maintenance of GoldSim models supporting the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) performance assessments (PAs) and composite analyses (CAs). Two PA models have been approved by the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO) as of November 2006 for the PA maintenance work undertaken by National Security Technologies, LLC (NSTec). NNSA/NSO asked NSTec to assume the custodianship of the models for future development and maintenance. The models were initially developed by Neptune and Company (N and C)

  13. Software Quality Assurance Plan for GoldSim Models Supporting the Area 3 and Area 5 Radioactive Waste Management Sites Performance Assessment Program

    Energy Technology Data Exchange (ETDEWEB)

    Gregory J. Shott, Vefa Yucel

    2007-01-03

    This Software Quality Assurance Plan (SQAP) applies to the development and maintenance of GoldSim models supporting the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) performance assessments (PAs) and composite analyses (CAs). Two PA models have been approved by the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO) as of November 2006 for the PA maintenance work undertaken by National Security Technologies, LLC (NSTec). NNSA/NSO asked NSTec to assume the custodianship of the models for future development and maintenance. The models were initially developed by Neptune and Company (N&C).

  14. An Automated Home-Cage System to Assess Learning and Performance of a Skilled Motor Task in a Mouse Model of Huntington's Disease.

    Science.gov (United States)

    Woodard, Cameron L; Bolaños, Federico; Boyd, James D; Silasi, Gergely; Murphy, Timothy H; Raymond, Lynn A

    2017-01-01

    Behavioral testing is a critical step in assessing the validity of rodent models of neurodegenerative disease, as well as evaluating the efficacy of pharmacological interventions. In models of Huntington's disease (HD), a gradual progression of impairments is observed across ages, increasing the need for sensitive, high-throughput and longitudinal assessments. Recently, a number of automated systems have been developed to perform behavioral profiling of animals within their own home-cage, allowing for 24-h monitoring and minimizing experimenter interaction. However, as of yet, few of these have had functionality for the assessment of skilled motor learning, a relevant behavior for movement disorders such as HD. To address this, we assess a lever positioning task within the mouse home-cage. Animals first acquire a simple operant response, before moving to a second phase where they must learn to hold the lever for progressively longer in a rewarded position range. Testing with this paradigm has revealed the presence of distinct phenotypes in the YAC128 mouse model of HD at three early symptomatic time points. YAC128 mice at two months old, but not older, had a motor learning deficit when required to adapt their response to changes in task requirements. In contrast, six-month-old YAC128 mice had disruptions of normal circadian activity and displayed kinematic abnormalities during performance of the task, suggesting an impairment in motor control. This system holds promise for facilitating high throughput behavioral assessment of HD mouse models for preclinical therapeutic screening.

  15. Air Conditioner Compressor Performance Model

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Ning; Xie, YuLong; Huang, Zhenyu

    2008-09-05

    During the past three years, the Western Electricity Coordinating Council (WECC) Load Modeling Task Force (LMTF) has led the effort to develop the new modeling approach. As part of this effort, the Bonneville Power Administration (BPA), Southern California Edison (SCE), and Electric Power Research Institute (EPRI) Solutions tested 27 residential air-conditioning units to assess their response to delayed voltage recovery transients. After completing these tests, different modeling approaches were proposed, among them a performance modeling approach that proved to be one of the three favored for its simplicity and ability to recreate different SVR events satisfactorily. Funded by the California Energy Commission (CEC) under its load modeling project, researchers at Pacific Northwest National Laboratory (PNNL) led the follow-on task to analyze the motor testing data to derive the parameters needed to develop a performance models for the single-phase air-conditioning (SPAC) unit. To derive the performance model, PNNL researchers first used the motor voltage and frequency ramping test data to obtain the real (P) and reactive (Q) power versus voltage (V) and frequency (f) curves. Then, curve fitting was used to develop the P-V, Q-V, P-f, and Q-f relationships for motor running and stalling states. The resulting performance model ignores the dynamic response of the air-conditioning motor. Because the inertia of the air-conditioning motor is very small (H<0.05), the motor reaches from one steady state to another in a few cycles. So, the performance model is a fair representation of the motor behaviors in both running and stalling states.

  16. Assessment of Energy Performance and Emission Control Using Alternative Fuels in Cement Industry through a Process Model

    Directory of Open Access Journals (Sweden)

    Azad Rahman

    2017-12-01

    Full Text Available Cement manufacturing is one of the most energy intensive processes and is accountable for substantial pollutant emissions. Increasing energy costs compel stakeholders and researchers to search for alternative options to improve energy performance and reduce CO2 emissions. Alternative fuels offer a realistic solution towards the reduction of the usage of fossil fuels and the mitigation of pollutant emissions. This paper developed a process model of a precalciner kiln system in the cement industry using Aspen Plus software to simulate the effect of five alternative fuels on pollutant emissions and energy performance. The alternatives fuels used were tyre, municipal solid waste (MSW, meat and bone meal (MBM, plastic waste and sugarcane bagasse. The model was developed on the basis of energy and mass balance of the system and was validated against data from a reference cement plant. This study also investigated the effect of these alternative fuels on the quality of the clinker. The results indicated that up to a 4.4% reduction in CO2 emissions and up to a 6.4% reduction in thermal energy requirement could be achieved using these alternative fuels with 20% mix in coal. It was also found that the alternative fuels had minimum influence on the clinker quality except in the case of MSW. Overall, MBM was found to be a better option as it is capable on reducing energy requirement and CO2 emissions more than others. The outcomes of the study offer better understanding of the effects of solid alternative fuels to achieve higher energy performance and on mitigating pollutant emissions in cement industry.

  17. Summary of Conceptual Models and Data Needs to Support the INL Remote-Handled Low-Level Waste Disposal Facility Performance Assessment and Composite Analysis

    International Nuclear Information System (INIS)

    Sondrup, A. Jeff; Schafter, Annette L.; Rood, Arthur S.

    2010-01-01

    An overview of the technical approach and data required to support development of the performance assessment, and composite analysis are presented for the remote handled low-level waste disposal facility on-site alternative being considered at Idaho National Laboratory. Previous analyses and available data that meet requirements are identified and discussed. Outstanding data and analysis needs are also identified and summarized. The on-site disposal facility is being evaluated in anticipation of the closure of the Radioactive Waste Management Complex at the INL. An assessment of facility performance and of the composite performance are required to meet the Department of Energy's Low-Level Waste requirements (DOE Order 435.1, 2001) which stipulate that operation and closure of the disposal facility will be managed in a manner that is protective of worker and public health and safety, and the environment. The corresponding established procedures to ensure these protections are contained in DOE Manual 435.1-1, Radioactive Waste Management Manual (DOE M 435.1-1 2001). Requirements include assessment of (1) all-exposure pathways, (2) air pathway, (3) radon, and (4) groundwater pathway doses. Doses are computed from radionuclide concentrations in the environment. The performance assessment and composite analysis are being prepared to assess compliance with performance objectives and to establish limits on concentrations and inventories of radionuclides at the facility and to support specification of design, construction, operation and closure requirements. Technical objectives of the PA and CA are primarily accomplished through the development of an establish inventory, and through the use of predictive environmental transport models implementing an overarching conceptual framework. This document reviews the conceptual model, inherent assumptions, and data required to implement the conceptual model in a numerical framework. Available site-specific data and data sources

  18. Summary of Conceptual Models and Data Needs to Support the INL Remote-Handled Low-Level Waste Disposal Facility Performance Assessment and Composite Analysis

    Energy Technology Data Exchange (ETDEWEB)

    A. Jeff Sondrup; Annette L. Schafter; Arthur S. Rood

    2010-09-01

    An overview of the technical approach and data required to support development of the performance assessment, and composite analysis are presented for the remote handled low-level waste disposal facility on-site alternative being considered at Idaho National Laboratory. Previous analyses and available data that meet requirements are identified and discussed. Outstanding data and analysis needs are also identified and summarized. The on-site disposal facility is being evaluated in anticipation of the closure of the Radioactive Waste Management Complex at the INL. An assessment of facility performance and of the composite performance are required to meet the Department of Energy’s Low-Level Waste requirements (DOE Order 435.1, 2001) which stipulate that operation and closure of the disposal facility will be managed in a manner that is protective of worker and public health and safety, and the environment. The corresponding established procedures to ensure these protections are contained in DOE Manual 435.1-1, Radioactive Waste Management Manual (DOE M 435.1-1 2001). Requirements include assessment of (1) all-exposure pathways, (2) air pathway, (3) radon, and (4) groundwater pathway doses. Doses are computed from radionuclide concentrations in the environment. The performance assessment and composite analysis are being prepared to assess compliance with performance objectives and to establish limits on concentrations and inventories of radionuclides at the facility and to support specification of design, construction, operation and closure requirements. Technical objectives of the PA and CA are primarily accomplished through the development of an establish inventory, and through the use of predictive environmental transport models implementing an overarching conceptual framework. This document reviews the conceptual model, inherent assumptions, and data required to implement the conceptual model in a numerical framework. Available site-specific data and data sources

  19. Examination of the use of continuum versus discontinuum models for design and performance assessment for the Yucca Mountain site

    International Nuclear Information System (INIS)

    Board, M.

    1989-08-01

    This report examines the use of continuum and discontinuum numerical methods for analysis of the thermomechanical response of the rock mass at Yucca Mountain. Continuum numerical methods consider the rock to be a solid, unfractured body, whereas the discontinuum method is formulated specifically to account for the effects of discrete fractures. The fractures within the rock introduce overall non-linear material response due to slip and separation of rock blocks. Continuum models attempt to simulate this response through the use of non-linear constitutive laws. Discontinuum methods attempt to simulate the true response of the rock mass by correctly modeling the behavior of the joints as well as the deformability of the intact rock blocks. It is shown that, as the joint spacing, s, becomes small with respect to the size of the excavations, the behavior of the jointed rock approaches that of a solid with a form of elasto-plastic constitutive behavior. It is concluded that a continuum model with a form of ''ubiquitous'' or ''compliant joint'' plasticity law is probably sufficient for analysis of the thermomechanical response of excavations in welded tuff. However, one of the questions concerning Yucca Mountain which remains is the effect of fault structures on the stability performance of the repository, particularly under thermal and dynamic loads. Here, a true discontinuum approach seems necessary. 45 refs., 42 figs., 4 tabs

  20. Performance assessment of coupled processes

    International Nuclear Information System (INIS)

    Pigford, T.H.

    1987-01-01

    The author considers all processes to be coupled. For example, a waste package heats the surrounding rock and its pore water, creating gradients in density and pressure that result in increased water flow. That process can be described as coupled, in that the flow is a consequence of heating. In a narrower sense, one speaks also of the more weakly coupled transport processes, expressed by the Onsager reciprocal relations, that state that a transport current, i.e., flux, of heat is accompanied by a small transport current of material, as evidenced in isotope separation by thermal diffusion, the Thompson effect in thermoelectricity, etc. This paper presents a performance assessment of coupled processes

  1. Mean absolute error and root mean square error: which is the better metric for assessing model performance?

    Science.gov (United States)

    Brassington, Gary

    2017-04-01

    The mean absolute error (MAE) and root mean square error (RMSE) are two metrics that are often used interchangeably as measures of ocean forecast accuracy. Recent literature has debated which of these should be preferred though their conclusions have largely been based on empirical arguments. We note that in general, RM SE2 = M AE2 + V ARk [|ɛ|] PIC PIC such that RMSE includes both the MAE as well as additional information related to the variance (biased estimator) of the errors ɛ with sample size k. The greater sensitivity of RMSE to a small number of outliers is directly attributable to the variance of absolute error. Further statistical properties for both metrics are derived and compared based on the assumption that the errors are Gaussian. For an unbiased (or bias corrected) model both MAE and RMSE are shown to estimate the total error standard deviation to within a constant coefficient such that ° -- M AE ≈ 2/πRM SE PIC . Both metrics have comparable behaviour in response to model bias and asymptote to the model bias as the bias increases. MAE is shown to be an unbiased estimator while RMSE is a biased estimator. MAE also has a lower sample variance compared with RMSE indicating MAE is the most robust choice. For real-time applications where there is a likelihood of "bad" observations we recommend ° - ° ---° - π- -1- π- π- TESD = 2 M AE ± √k- 2 - 1 2M AE PIC as an unbiased estimator of the total error standard deviation with error estimates (one standard deviation) based on the sample variance and defined as a scaling of the MAE itself. A sample size (k) on the order of 90 and 9000 provides an error scaling of 10% and 1% respectively. Nonetheless if the model performance is being analysed using a large sample of delayed-mode quality controlled observations then RMSE might be preferred where the second moment sensitivity to large model errors is important. Alternatively for model intercomparisons the information might compactly represented by a

  2. 5th Total System Performance Assessment Workshop

    International Nuclear Information System (INIS)

    Hwang, Yong Soo; Lee, Youn Myoung; Kang, Chul Hyung; Lee, Sung Ho

    2009-07-01

    Research items on safety assessment of high-level waste repository have been proposed by external invited experts outside KAERI and discussed extensively during the annual 5th performance assessment workshop prepared by safety assessment group in KAERI. This could be useful to set up R and D plans necessary for the next phase of mid- and long-term reaserch area regarding the safety assessment of high-level waste repository. Through the research and the presentation, HLW-related research and development area including such specific research items as current status of HLW safety assessment research, current requirement for the licensing of the repository system, priority on research area, data base building for the safety assessment, source-term modeling as well as safety case, among many others, have been discussed and summarized

  3. Swimming performance assessment in fishes.

    Science.gov (United States)

    Tierney, Keith B

    2011-05-20

    Swimming performance tests of fish have been integral to studies of muscle energetics, swimming mechanics, gas exchange, cardiac physiology, disease, pollution, hypoxia and temperature. This paper describes a flexible protocol to assess fish swimming performance using equipment in which water velocity can be controlled. The protocol involves one to several stepped increases in flow speed that are intended to cause fish to fatigue. Step speeds and their duration can be set to capture swimming abilities of different physiological and ecological relevance. Most frequently step size is set to determine critical swimming velocity (U(crit;)), which is intended to capture maximum sustained swimming ability. Traditionally this test has consisted of approximately ten steps each of 20 min duration. However, steps of shorter duration (e.g. 1 min) are increasingly being utilized to capture acceleration ability or burst swimming performance. Regardless of step size, swimming tests can be repeated over time to gauge individual variation and recovery ability. Endpoints related to swimming such as measures of metabolic rate, fin use, ventilation rate, and of behavior, such as the distance between schooling fish, are often included before, during and after swimming tests. Given the diversity of fish species, the number of unexplored research questions, and the importance of many species to global ecology and economic health, studies of fish swimming performance will remain popular and invaluable for the foreseeable future.

  4. Improving the performance of a Seawater Greenhouse desalination system by assessment of simulation models for different condensers

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoudi, Hacene [Laboratory of Water and Environment, Hassiba Ben Bouali University, Chlef BP151 (Algeria); Faculty of Sciences and Engineering Sciences, Hassiba Ben Bouali University, Chlef BP151 (Algeria); Spahis, Nawel [Faculty of Sciences and Engineering Sciences, Hassiba Ben Bouali University, Chlef BP151 (Algeria); Abdul-Wahab, Sabah A. [College of Engineering, P.O. Box 33, Sultan Qaboos University, Al-Khod 123, Muscat (Oman); Sablani, Shyam S. [Biological Systems Engineering, Washington State University, Pullman, WA (United States); Goosen, Mattheus F.A. [Alfaisal University, P.O. Box 50927, Riyadh 11533 (Saudi Arabia)

    2010-10-15

    The main aim of this paper was the development of a mathematical model for a new proposed passive condenser in order to enhance the performance of a humidification-dehumidification Seawater Greenhouse desalination system. Seawater Greenhouse desalination is used to create a cool environment and at the same time to produce fresh water for irrigation of crops grown inside the unit. The condenser in particular is currently one of the main bottlenecks in the commercialization of the technology. In addition to the current pump driven condenser, two new designs were considered: a passive cooling system with a condenser immersed in a water basin, and an external passive condenser connected to a basin of water placed on top of the cooling unit. The simulated condensate values for the proposed passive cooling condenser were compared with that of the actual measured values of the installed condenser. Preliminary results suggest that the passive condenser has a much greater water production capacity than the existing pump driven system. While the model for the proposed system still needs to be validated experimentally the initial study indicates that the passive containment cooling system is a promising improvement in the further development of greenhouse desalination. (author)

  5. Groundwater flow inverse modeling in non-MultiGaussian media: performance assessment of the normal-score Ensemble Kalman Filter

    Directory of Open Access Journals (Sweden)

    L. Li

    2012-02-01

    Full Text Available The normal-score ensemble Kalman filter (NS-EnKF is tested on a synthetic aquifer characterized by the presence of channels with a bimodal distribution of its hydraulic conductivities. This is a clear example of an aquifer that cannot be characterized by a multiGaussian distribution. Fourteen scenarios are analyzed which differ among them in one or various of the following aspects: the prior random function model, the boundary conditions of the flow problem, the number of piezometers used in the assimilation process, or the use of covariance localization in the implementation of the Kalman filter. The performance of the NS-EnKF is evaluated through the ensemble mean and variance maps, the connectivity patterns of the individual conductivity realizations and the degree of reproduction of the piezometric heads. The results show that (i the localized NS-EnKF can characterize the non-multiGaussian underlying hydraulic distribution even when an erroneous prior random function model is used, (ii localization plays an important role to prevent filter inbreeding and results in a better logconductivity characterization, and (iii the NS-EnKF works equally well under very different flow configurations.

  6. DRSPALL: Impact of the Modification of the Numerical Spallings Model on Waste Isolation Pilot Plant Performance Assessment.

    Energy Technology Data Exchange (ETDEWEB)

    Kicker, Dwayne Curtis [Stoller Newport News Nuclear, Inc., Carlsbad, NM (United States); Herrick, Courtney G. [Sandia National Lab. (SNL-NM), Carlsbad, NM (United States); Zeitler, Todd [Sandia National Lab. (SNL-NM), Carlsbad, NM (United States); Malama, Bwalya [Sandia National Lab. (SNL-NM), Carlsbad, NM (United States); Rudeen, David Keith [GRAM Inc., Albuquerque, NM (United States); Gilkey, Amy P. [GRAM Inc., Albuquerque, NM (United States)

    2016-01-01

    The numerical code DRSPALL (from direct release spallings) is written to calculate the volume of Waste Isolation Pilot Plant (WIPP) solid waste subject to material failure and transport to the surface as a result of a hypothetical future inadvertent drilling intrusion. An error in the implementation of the DRSPALL finite difference equations was discovered as documented in Software Problem Report (SPR) 13-001. The modifications to DRSPALL to correct the finite difference equations are detailed, and verification and validation testing has been completed for the modified DRSPALL code. The complementary cumulative distribution function (CCDF) of spallings releases obtained using the modified DRSPALL is higher compared to that found in previous WIPP performance assessment (PA) calculations. Compared to previous PAs, there was an increase in the number of vectors that result in a nonzero spallings volume, which generally translates to an increase in spallings releases. The overall mean CCDFs for total releases using the modified DRSPALL are virtually unchanged, thus the modification to DRSPALL did not impact WIPP PA calculation results.

  7. Microbial Performance of Food Safety Control and Assurance Activities in a Fresh Produce Processing Sector Measured Using a Microbial Assessment Scheme and Statistical Modeling

    DEFF Research Database (Denmark)

    Njage, Patrick Murigu Kamau; Sawe, Chemutai Tonui; Onyango, Cecilia Moraa

    2017-01-01

    Current approaches such as inspections, audits, and end product testing cannot detect the distribution and dynamics of microbial contamination. Despite the implementation of current food safety management systems, foodborne outbreaks linked to fresh produce continue to be reported. A microbial...... assessment scheme and statistical modeling were used to systematically assess the microbial performance of core control and assurance activities in five Kenyan fresh produce processing and export companies. Generalized linear mixed models and correlated random-effects joint models for multivariate clustered...... data followed by empirical Bayes estimates enabled the analysis of the probability of contamination across critical sampling locations (CSLs) and factories as a random effect. Salmonella spp. and Listeria monocytogenes were not detected in the final products. However, none of the processors attained...

  8. Performance Assessment and Translation of Physiologically Based Pharmacokinetic Models From acslX to Berkeley Madonna, MATLAB, and R Language: Oxytetracycline and Gold Nanoparticles As Case Examples.

    Science.gov (United States)

    Lin, Zhoumeng; Jaberi-Douraki, Majid; He, Chunla; Jin, Shiqiang; Yang, Raymond S H; Fisher, Jeffrey W; Riviere, Jim E

    2017-07-01

    Many physiologically based pharmacokinetic (PBPK) models for environmental chemicals, drugs, and nanomaterials have been developed to aid risk and safety assessments using acslX. However, acslX has been rendered sunset since November 2015. Alternative modeling tools and tutorials are needed for future PBPK applications. This forum article aimed to: (1) demonstrate the performance of 4 PBPK modeling software packages (acslX, Berkeley Madonna, MATLAB, and R language) tested using 2 existing models (oxytetracycline and gold nanoparticles); (2) provide a tutorial of PBPK model code conversion from acslX to Berkeley Madonna, MATLAB, and R language; (3) discuss the advantages and disadvantages of each software package in the implementation of PBPK models in toxicology, and (4) share our perspective about future direction in this field. Simulation results of plasma/tissue concentrations/amounts of oxytetracycline and gold from different models were compared visually and statistically with linear regression analyses. Simulation results from the original models were correlated well with results from the recoded models, with time-concentration/amount curves nearly superimposable and determination coefficients of 0.86-1.00. Step-by-step explanations of the recoding of the models in different software programs are provided in the Supplementary Data. In summary, this article presents a tutorial of PBPK model code conversion for a small molecule and a nanoparticle among 4 software packages, and a performance comparison of these software packages in PBPK model implementation. This tutorial helps beginners learn PBPK modeling, provides suggestions for selecting a suitable tool for future projects, and may lead to the transition from acslX to alternative modeling tools. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  9. Improved power performance assessment methods

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, S.; Antoniou, I.; Dahlberg, J.A. [and others

    1999-03-01

    The uncertainty of presently-used methods for retrospective assessment of the productive capacity of wind farms is unacceptably large. The possibilities of improving the accuracy have been investigated and are reported. A method is presented that includes an extended power curve and site calibration. In addition, blockage effects with respect to reference wind speed measurements are analysed. It is found that significant accuracy improvements are possible by the introduction of more input variables such as turbulence and wind shear, in addition to mean wind speed and air density. Also, the testing of several or all machines in the wind farm - instead of only one or two - may provide a better estimate of the average performance. (au)

  10. Statistical model based iterative reconstruction (MBIR) in clinical CT systems. Part II. Experimental assessment of spatial resolution performance

    International Nuclear Information System (INIS)

    Li, Ke; Chen, Guang-Hong; Garrett, John; Ge, Yongshuai

    2014-01-01

    Purpose: Statistical model based iterative reconstruction (MBIR) methods have been introduced to clinical CT systems and are being used in some clinical diagnostic applications. The purpose of this paper is to experimentally assess the unique spatial resolution characteristics of this nonlinear reconstruction method and identify its potential impact on the detectabilities and the associated radiation dose levels for specific imaging tasks. Methods: The thoracic section of a pediatric phantom was repeatedly scanned 50 or 100 times using a 64-slice clinical CT scanner at four different dose levels [CTDI vol =4, 8, 12, 16 (mGy)]. Both filtered backprojection (FBP) and MBIR (Veo ® , GE Healthcare, Waukesha, WI) were used for image reconstruction and results were compared with one another. Eight test objects in the phantom with contrast levels ranging from 13 to 1710 HU were used to assess spatial resolution. The axial spatial resolution was quantified with the point spread function (PSF), while the z resolution was quantified with the slice sensitivity profile. Both were measured locally on the test objects and in the image domain. The dependence of spatial resolution on contrast and dose levels was studied. The study also features a systematic investigation of the potential trade-off between spatial resolution and locally defined noise and their joint impact on the overall image quality, which was quantified by the image domain-based channelized Hotelling observer (CHO) detectability index d′. Results: (1) The axial spatial resolution of MBIR depends on both radiation dose level and image contrast level, whereas it is supposedly independent of these two factors in FBP. The axial spatial resolution of MBIR always improved with an increasing radiation dose level and/or contrast level. (2) The axial spatial resolution of MBIR became equivalent to that of FBP at some transitional contrast level, above which MBIR demonstrated superior spatial resolution than FBP (and

  11. Evaluation of vegetable protein in canine diets: Assessment of performance and apparent ileal amino acid digestibility using a broiler model.

    Science.gov (United States)

    Fiacco, D C; Lowe, J A; Wiseman, J; White, G A

    2018-02-01

    Recent technological advances in the human food industry with respect to meat processing have decreased the availability of animal proteins to the pet food industry which typically formulates diets with an excess of animal protein. In the long term, this is not sustainable; thus, alternative protein sources need to be investigated. This study examined three canine diets, comparing a typical animal protein-based diet (control) with two experimental diets where the animal protein was substituted in part with vegetable protein (formulated based either on total protein or amino acid content) using a broiler model. Each diet was fed to six cages each containing two birds from day 15, 18 cages in total (36 birds). Excreta were collected from days 19 to 21. On day 23, birds were euthanized and weighed, and their ileal digesta were collected and pooled for each cage. In addition, one leg per cage was collected for evaluation of muscle mass. Results showed no significant difference in animal performance (feed intake or live weight gain) or muscle to leg proportion across the diets. Birds fed the control diet and the diet balanced for amino acid content exhibited the greatest coefficients of apparent metabolizability for nitrogen (p animal with vegetable protein generally had greater ileal digestibility of amino acids compared to birds fed the control (animal protein) diet. Analysis of excreta showed no dietary difference in terms of dry matter content; however, birds fed the diet balanced for total protein and the diet balanced for amino acid content had significantly greater excreta nitrogen than the control (p = .038). Overall, the study suggests vegetable proteins when formulated based on amino acid content are a viable alternative to animal proteins in canine diets. © 2017 Blackwell Verlag GmbH.

  12. Expert judgement in performance assessment

    International Nuclear Information System (INIS)

    Wilmot, R.D.; Galson, D.A.

    2000-01-01

    This report is a pilot study that systematically describes the various types of expert judgement that are made throughout the development of a PA, and summarizes existing tools and practices for dealing with expert judgements. The report also includes recommendations for further work in the area of expert judgement. Expert judgements can be classified in a number of ways, including classification according to why the judgements are made and according to how the judgements are made. In terms of why judgements are made, there is a broad distinction between: Judgements concerning data that are made because alternatives are not feasible; and Judgements about the conduct of a PA that are made because there are no alternative approaches for making the decision. In the case of how judgements are made, the report distinguishes between non-elicited judgements made by individuals, non-elicited judgements made by groups, and elicited judgements made by individuals or groups. These types of judgement can generally be distinguished by the extent of the associated documentation, and hence their traceability. Tools for assessing judgements vary depending on the type of judgements being examined. Key tools are peer review, an appropriate QA regime, documentation, and elicitation. Dialogue with stake holders is also identified as important in establishing whether judgements are justified in the context in which they are used. The PA process comprises a number of stages, from establishing the assessment context, through site selection and repository design, to scenario and model development and parametrisation. The report discusses how judgements are used in each of these stages, and identifies which of the tools and procedures for assessing judgements are most appropriate at each stage. Recommendations for further work include the conduct of a trial expert elicitation to gain experience in the advantages and disadvantages of this technique, the development of guidance for peer

  13. Endoscopy nurse-administered propofol sedation performance. Development of an assessment tool and a reliability testing model

    DEFF Research Database (Denmark)

    Jensen, Jeppe Thue; Konge, Lars; Møller, Ann

    2014-01-01

    -like fashion. Consensus was achieved on 17 items. Validity evidence was gathered in a case-control study in a full-scale simulation setting. Six experienced nurses and six novice nurses were filmed in two scenarios for assessment according to the assessment tool by three content expert raters. RESULTS: A total...... of training and for future certification. The aim of this study was to develop an assessment tool for measuring competency in propofol sedation and to explore the reliability and validity of the tool. MATERIAL AND METHODS: The nurse-administered propofol assessment tool (NAPSAT) was developed in a Delphi......OBJECTIVE: A gold standard of skills required for nurse-administered propofol sedation (NAPS) for gastroenterological endoscopic procedures has been proposed but not established. Due to the potentially hazardous nature of NAPS, an assessment tool is needed to objectively judge the adequacy...

  14. Radioactive Waste Management Complex performance assessment: Draft

    Energy Technology Data Exchange (ETDEWEB)

    Case, M.J.; Maheras, S.J.; McKenzie-Carter, M.A.; Sussman, M.E.; Voilleque, P.

    1990-06-01

    A radiological performance assessment of the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory was conducted to demonstrate compliance with appropriate radiological criteria of the US Department of Energy and the US Environmental Protection Agency for protection of the general public. The calculations involved modeling the transport of radionuclides from buried waste, to surface soil and subsurface media, and eventually to members of the general public via air, ground water, and food chain pathways. Projections of doses were made for both offsite receptors and individuals intruding onto the site after closure. In addition, uncertainty analyses were performed. Results of calculations made using nominal data indicate that the radiological doses will be below appropriate radiological criteria throughout operations and after closure of the facility. Recommendations were made for future performance assessment calculations.

  15. Preliminary assessment of Ignitor performances

    Energy Technology Data Exchange (ETDEWEB)

    Johner, J

    2000-04-01

    Thermal equilibrium O-D calculations are shown to give useful information in the case of non-stationary discharges if a proper generalization of the plasma amplification factor Q* is chosen. With this definition, Q*={infinity} corresponds to a plasma state where P{sub {alpha}} P{sub loss}. This approach is used for a preliminary assessment of Ignitor performances. For parabolic density and temperature profiles, it is shown that Q{sup *}={infinity} can be obtained in this machine only for an enhancement factor H{sub L} with respect to ITER-97P(th) scaling law of the energy confinement time of the order of 1.9. Using ITER-FEAT assumptions for the density and temperature profiles, it is shown that Q{sup *}={infinity} can be obtained in H-mode with IPB98(y,2) scaling of the energy confinement time. Analysis of the reference operating point of Ignitor proposed by Coppi et al. shows that their alpha power and energy content can be reproduced only with peaked density and temperature profiles. With such profiles, Q{sup *}={infinity} still requires an enhancement factor H{sub L} of 1.44. (author)

  16. 24 CFR 115.206 - Performance assessments; Performance standards.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Performance assessments; Performance standards. 115.206 Section 115.206 Housing and Urban Development Regulations Relating to Housing... AGENCIES Certification of Substantially Equivalent Agencies § 115.206 Performance assessments; Performance...

  17. SITE-94. Discrete-feature modelling of the Aespoe Site: 3. Predictions of hydrogeological parameters for performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Geier, J.E. [Golder Associates AB, Uppsala (Sweden)

    1996-12-01

    A 3-dimensional, discrete-feature hydrological model is developed. The model integrates structural and hydrologic data for the Aespoe site, on scales ranging from semi regional fracture zones to individual fractures in the vicinity of the nuclear waste canisters. Predicted parameters for the near field include fracture spacing, fracture aperture, and Darcy velocity at each of forty canister deposition holes. Parameters for the far field include discharge location, Darcy velocity, effective longitudinal dispersion coefficient and head gradient, flow porosity, and flow wetted surface, for each canister source that discharges to the biosphere. Results are presented in the form of statistical summaries for a total of 42 calculation cases, which treat a set of 25 model variants in various combinations. The variants for the SITE-94 Reference Case model address conceptual and parametric uncertainty related to the site-scale hydrogeologic model and its properties, the fracture network within the repository, effective semi regional boundary conditions for the model, and the disturbed-rock zone around the repository tunnels and shafts. Two calculation cases simulate hydrologic conditions that are predicted to occur during future glacial episodes. 30 refs.

  18. Model performance analysis and model validation in logistic regression

    Directory of Open Access Journals (Sweden)

    Rosa Arboretti Giancristofaro

    2007-10-01

    Full Text Available In this paper a new model validation procedure for a logistic regression model is presented. At first, we illustrate a brief review of different techniques of model validation. Next, we define a number of properties required for a model to be considered "good", and a number of quantitative performance measures. Lastly, we describe a methodology for the assessment of the performance of a given model by using an example taken from a management study.

  19. A multi-decadal assessment of the performance of gauge- and model-based rainfall products over Saudi Arabia: Climatology, anomalies and trends

    KAUST Repository

    El Kenawy, Ahmed M.

    2015-05-15

    Many arid and semi-arid regions have sparse precipitation observing networks, which limits the capacity for detailed hydrological modelling, water resources management and flood forecasting efforts. The objective of this work is to evaluate the utility of relatively high-spatial resolution rainfall products to reproduce observed multi-decadal rainfall characteristics such as climatologies, anomalies and trends over Saudi Arabia. Our study compares the statistical characteristics of rainfall from 53 observatories over the reference period 1965-2005, with rainfall data from six widely used gauge-based products, including APHRODITE, GPCC, PRINCETON, UDEL, CRU and PREC/L. In addition, the performance of three global climate models (GCMs), including CCSM4, EC-EARTH and MRI-I-CGCM3, integrated as part of the Fifth Coupled Model Intercomparison Project (CMIP5), was also evaluated. Results indicate that the gauge-based products were generally skillful in reproducing rainfall characteristics in Saudi Arabia. In most cases, the gauge-based products were also able to capture the annual cycle, anomalies and climatologies of observed data, although significant inter-product variability was observed, depending on the assessment metric being used. In comparison, the GCM-based products generally exhibited poor performance, with larger biases and very weak correlations, particularly during the summertime. Importantly, all products generally failed to reproduce the observed long-term seasonal and annual trends in the region, particularly during the dry seasons (summer and autumn). Overall, this work suggests that selected gauge-based products with daily (APHRODITE and PRINCETON) and monthly (GPCC and CRU) resolutions show superior performance relative to other products, implying that they may be the most appropriate data source from which multi-decadal variations of rainfall can be investigated at the regional scale over Saudi Arabia. Discriminating these skillful products is

  20. Making Performance Assessments a Part of Accountability

    Science.gov (United States)

    Haun, Billy

    2018-01-01

    The purpose of this commentary is to describe recent efforts in Virginia to develop and use performance assessments, including the challenges that emerged during this process and key considerations for states that integrate performance assessment into their systems. Performance assessments can play an important role in preparing students for…

  1. Performance assessment of retrospective meteorological inputs for use in air quality modeling during TexAQS 2006

    Science.gov (United States)

    Ngan, Fong; Byun, Daewon; Kim, Hyuncheol; Lee, Daegyun; Rappenglück, Bernhard; Pour-Biazar, Arastoo

    2012-07-01

    To achieve more accurate meteorological inputs than was used in the daily forecast for studying the TexAQS 2006 air quality, retrospective simulations were conducted using objective analysis and 3D/surface analysis nudging with surface and upper observations. Model ozone using the assimilated meteorological fields with improved wind fields shows better agreement with the observation compared to the forecasting results. In the post-frontal conditions, important factors for ozone modeling in terms of wind patterns are the weak easterlies in the morning for bringing in industrial emissions to the city and the subsequent clockwise turning of the wind direction induced by the Coriolis force superimposing the sea breeze, which keeps pollutants in the urban area. Objective analysis and nudging employed in the retrospective simulation minimize the wind bias but are not able to compensate for the general flow pattern biases inherited from large scale inputs. By using an alternative analyses data for initializing the meteorological simulation, the model can re-produce the flow pattern and generate the ozone peak location closer to the reality. The inaccurate simulation of precipitation and cloudiness cause over-prediction of ozone occasionally. Since there are limitations in the meteorological model to simulate precipitation and cloudiness in the fine scale domain (less than 4-km grid), the satellite-based cloud is an alternative way to provide necessary inputs for the retrospective study of air quality.

  2. Effects of Uncertainty and Spatial Variability on Seepage into Drifts in the Yucca Mountain Total system Performance Assessment Model

    International Nuclear Information System (INIS)

    Kalinich, D. A.; Wilson, M. L.

    2001-01-01

    Seepage into the repository drifts is an important factor in total-system performance. Uncertainty and spatial variability are considered in the seepage calculations. The base-case results show 13.6% of the waste packages (WPs) have seepage. For 5th percentile uncertainty, 4.5% of the WPs have seepage and the seepage flow decreased by a factor of 2. For 95th percentile uncertainty, 21.5% of the WPs have seepage and the seepage flow increased by a factor of 2. Ignoring spatial variability resulted in seepage on 100% of the WPs, with a factor of 3 increase in the seepage flow

  3. Numerical Modelling for the Thermal Performance Assessment of a Semi-Opaque Façade with a Multilayer of Nano-Structured and Phase Change Materials

    Directory of Open Access Journals (Sweden)

    Carla Balocco

    2017-10-01

    Full Text Available The aim of our present study was to assess and compare the thermo-physical and energy behaviour of different integrated building façades, using a multi-physics simulation approach. Advanced integrated façades composed of opaque modules, one of them with a phase change materials (PCM layer, the others with multilayer panels, combined with transparent ones, consisting of nano-structured materials and new-generation photovoltaic systems, were investigated. A multi-physics approach was used for the design optimization of the studied components and evaluation of their thermo-physical and heat transfer performance. In particular, computational fluid dynamics (CFD multi-physics transient simulations were performed to assess air temperature and velocity fields inside the ventilated cavities. Analysis of heat and mass exchange through all the components was assessed during heating and cooling mode of a reference building. The typical Mediterranean climate was considered. Results comparison allowed the dynamic heat transfer evaluation of the multilayer façades as a function of variable climatic conditions, and their flexibility and adaptability exploitation, when different energy strategies are pursued. The multi-physics modelling approach used, proved to be a strong tool for the energy design optimization and energy sustainability evaluation of different advance materials and building components.

  4. Principles of Sonar Performance Modeling

    NARCIS (Netherlands)

    Ainslie, M.A.

    2010-01-01

    Sonar performance modelling (SPM) is concerned with the prediction of quantitative measures of sonar performance, such as probability of detection. It is a multidisciplinary subject, requiring knowledge and expertise in the disparate fields of underwater acoustics, acoustical oceanography, sonar

  5. The Use of Numerical Models in Support of Site Characterization and Performance Assessment Studies of Geological Repositories. Results of an IAEA Coordinated Research Project 2005-2010

    International Nuclear Information System (INIS)

    2013-10-01

    The siting, development and operation of waste disposal facilities, and the related safety issues, have been described in many IAEA publications. The safe management and disposal of radioactive waste from the nuclear fuel cycle remains a necessary condition for future development of nuclear energy. In particular, the disposal of high level waste and spent nuclear fuel in geological repositories, despite having been studied worldwide over the past several decades, still requires full scale demonstration through safe implementation, as planned at the national level in Finland and Sweden by 2020 and 2023, respectively, and in France by 2025. Safety assessment techniques are currently applicable to potential facility location and development through a quite large range of approaches and methodologies. By implementing research activities through coordinated research projects (CRPs), the IAEA enables research institutes in both developing and developed Member States to collaborate on research topics of common interest. In response to requests by several Member States in different networks and platforms dealing with waste disposal, in 2005 a CRP on The Use of Numerical Models in Support of Site Characterization and Performance Assessment Studies of Geological Repositories was proposed and developed to transfer modelling expertise and numerical simulation technology to countries needing them for their national nuclear waste management programmes. All Member States involved in this CRP have acquired the scientific basis for, and expertise in, the site characterization process, including test design, data analysis, model calibration, model validation, predictive modelling, sensitivity analysis and uncertainty propagation analysis. This expertise is documented in this publication, in which numerical modelling is used to address the pertinent issue of site characterization and its impact on safety, using data and information from a potential repository site

  6. Predictive Model Assessment for Count Data

    National Research Council Canada - National Science Library

    Czado, Claudia; Gneiting, Tilmann; Held, Leonhard

    2007-01-01

    .... In case studies, we critique count regression models for patent data, and assess the predictive performance of Bayesian age-period-cohort models for larynx cancer counts in Germany. Key words: Calibration...

  7. Use of thermodynamic sorption models to derive radionuclide Kd values for performance assessment: Selected results and recommendations of the NEA sorption project

    Science.gov (United States)

    Ochs, M.; Davis, J.A.; Olin, M.; Payne, T.E.; Tweed, C.J.; Askarieh, M.M.; Altmann, S.

    2006-01-01

    For the safe final disposal and/or long-term storage of radioactive wastes, deep or near-surface underground repositories are being considered world-wide. A central safety feature is the prevention, or sufficient retardation, of radionuclide (RN) migration to the biosphere. To this end, radionuclide sorption is one of the most important processes. Decreasing the uncertainty in radionuclide sorption may contribute significantly to reducing the overall uncertainty of a performance assessment (PA). For PA, sorption is typically characterised by distribution coefficients (Kd values). The conditional nature of Kd requires different estimates of this parameter for each set of geochemical conditions of potential relevance in a RN's migration pathway. As it is not feasible to measure sorption for every set of conditions, the derivation of Kd for PA must rely on data derived from representative model systems. As a result, uncertainty in Kd is largely caused by the need to derive values for conditions not explicitly addressed in experiments. The recently concluded NEA Sorption Project [1] showed that thermodynamic sorption models (TSMs) are uniquely suited to derive K d as a function of conditions, because they allow a direct coupling of sorption with variable solution chemistry and mineralogy in a thermodynamic framework. The results of the project enable assessment of the suitability of various TSM approaches for PA-relevant applications as well as of the potential and limitations of TSMs to model RN sorption in complex systems. ?? by Oldenbourg Wissenschaftsverlag.

  8. Contractor Performance Assessment Reporting System

    Data.gov (United States)

    US Agency for International Development — CPARS is a web-based system used to input data on contractor performance. Reports from the system are used as an aid in awarding contracts to contractors that...

  9. Application of an Artificial Stomach-Duodenum Reduced Gastric pH Dog Model for Formulation Principle Assessment and Mechanistic Performance Understanding.

    Science.gov (United States)

    Lee, Chen-Ming; Luner, Paul E; Locke, Karen; Briggs, Katherine

    2017-08-01

    The objective of this study was to develop an artificial stomach-duodenum (ASD) dissolution model as an in vitro evaluation tool that would simulate the gastrointestinal physiology of gastric pH-reduced dogs as a method to assess formulations for a poorly soluble free acid compound with ng/mL solubility. After establishing the ASD model with well-controlled duodenum pH, 5 formulations each applying different solubilization principles were developed and their performance in the ASD model and in vivo in dogs was evaluated. Excellent correlations were obtained between dog area under the curve (AUC) and ASD AUC of 5 formulations evaluated with simulated intestinal fluid (r 2  = 0.987) and fasted-state simulated intestinal fluid (r 2  = 0.989) as the duodenum dissolution medium, indicating that the approach of infusing NaOH into duodenum compartment to maintain duodenum pH of an ASD worked properly in simulating gastric pH-reduced dog. Raman spectroscopy was used to study drug dissolution kinetics associated with different solubilization principles and the results suggested that the solubilization principles performed as designed. Spectroscopic results also identified that the compound formed a gel during dissolution and hypromellose maintained the drug-gelled state to avoid further solid form conversion. The implication of the compound physical gelation to drug dissolution kinetics and in vivo exposure are discussed. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  10. Nanotechnologies: Risk assessment model

    Science.gov (United States)

    Giacobbe, F.; Monica, L.; Geraci, D.

    2009-05-01

    The development and use of nanomaterials has grown widely in the last years. Hence, it is necessary to carry out a careful and aimed risk assessment for the safety of the workers. The objective of this research is a specific assessment model finalized to the workplaces where the personnel work manipulating nanoparticles. This model mainly takes into account the number of exposed workers, the dimensions of particles, the information found in the safety data sheets and the uncertainties about the danger level coming from the exposition to nanomaterials. The evaluation algorithm considers the normal work conditions, the abnormal (e.g. breakdown air filter) and emergency situations (e.g. package cracking). It has been necessary to define several risk conditions in order to quantify the risk by increasing levels ("low", "middle" and "high" level). Each level includes appropriate behavioural procedures. In particular for the high level, it is advisable that the user carries out urgent interventions finalized to reduce the risk level (e.g. the utilization of vacuum box for the manipulation, high efficiency protection PPE, etc). The model has been implemented in a research laboratory where titanium dioxide and carbon nanotubes are used. The outcomes taken out from such specific evaluation gave a risk level equal to middle.

  11. Nanotechnologies: Risk assessment model

    International Nuclear Information System (INIS)

    Giacobbe, F; Monica, L; Geraci, D

    2009-01-01

    The development and use of nanomaterials has grown widely in the last years. Hence, it is necessary to carry out a careful and aimed risk assessment for the safety of the workers. The objective of this research is a specific assessment model finalized to the workplaces where the personnel work manipulating nanoparticles. This model mainly takes into account the number of exposed workers, the dimensions of particles, the information found in the safety data sheets and the uncertainties about the danger level coming from the exposition to nanomaterials. The evaluation algorithm considers the normal work conditions, the abnormal (e.g. breakdown air filter) and emergency situations (e.g. package cracking). It has been necessary to define several risk conditions in order to quantify the risk by increasing levels ('low', 'middle' and 'high' level). Each level includes appropriate behavioural procedures. In particular for the high level, it is advisable that the user carries out urgent interventions finalized to reduce the risk level (e.g. the utilization of vacuum box for the manipulation, high efficiency protection PPE, etc). The model has been implemented in a research laboratory where titanium dioxide and carbon nanotubes are used. The outcomes taken out from such specific evaluation gave a risk level equal to middle.

  12. Characterising performance of environmental models

    NARCIS (Netherlands)

    Bennett, N.D.; Croke, B.F.W.; Guariso, G.; Guillaume, J.H.A.; Hamilton, S.H.; Jakeman, A.J.; Marsili-Libelli, S.; Newham, L.T.H.; Norton, J.; Perrin, C.; Pierce, S.; Robson, B.; Seppelt, R.; Voinov, A.; Fath, B.D.; Andreassian, V.

    2013-01-01

    In order to use environmental models effectively for management and decision-making, it is vital to establish an appropriate level of confidence in their performance. This paper reviews techniques available across various fields for characterising the performance of environmental models with focus

  13. Integrated Assessment Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Edmonds, James A.; Calvin, Katherine V.; Clarke, Leon E.; Janetos, Anthony C.; Kim, Son H.; Wise, Marshall A.; McJeon, Haewon C.

    2012-10-31

    This paper discusses the role of Integrated Assessment models (IAMs) in climate change research. IAMs are an interdisciplinary research platform, which constitutes a consistent scientific framework in which the large-scale interactions between human and natural Earth systems can be examined. In so doing, IAMs provide insights that would otherwise be unavailable from traditional single-discipline research. By providing a broader view of the issue, IAMs constitute an important tool for decision support. IAMs are also a home of human Earth system research and provide natural Earth system scientists information about the nature of human intervention in global biogeophysical and geochemical processes.

  14. Performance Assessment in Courts - The Swiss Case

    Directory of Open Access Journals (Sweden)

    Andreas Lienhard

    2014-12-01

    Full Text Available Abstract Performance assessments have become commonplace in management, even in the public sector. With the increasing pressure on courts to perform while making efficient use of resources, performance assessments in the justice system are also gaining in importance. However, the need for judicial independence poses special challenges for performance assessments in courts. Against this background, this article conducts a constitutional appraisal, and contrasts the need for judicial independence with the principles governing effectiveness and efficiency, self-government and supervision, and appointment and re-appointment. A duty to guarantee justice can be derived from this that does not in principle exclude the performance assessment of judges, but even renders it essential, subject to compliance with certain requirements. In these circumstances, it seems hardly surprising that numerous countries conduct performance assessments of judges and also that various international institutions have developed principles for this purpose, a summary of which is presented – in Switzerland’s case based on a recently conducted survey. In the field of conflict between the guaranteeing justice and protecting the judiciary, the following key questions arise in particular: What is the purpose of performance assessments and what are the consequences?What is subjected to a performance assessment and what are the assessment criteria?How is performance recorded as the basis for the performance assessment?Who is subjected to a performance assessment, and must a distinction be made between judges in higher and lower courts?Who carries out the performance assessment and what methods of protecting one’s rights are available?Who should receive the results of the performance assessment?The contribution sketches out possible answers to these key questions and aims to encourage academics and practitioners to give further consideration to this subject.

  15. Simplified Predictive Models for CO2 Sequestration Performance Assessment: Research Topical Report on Task #4 - Reduced-Order Method (ROM) Based Models

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Srikanta; Jin, Larry; He, Jincong; Durlofsky, Louis

    2015-06-30

    Reduced-order models provide a means for greatly accelerating the detailed simulations that will be required to manage CO2 storage operations. In this work, we investigate the use of one such method, POD-TPWL, which has previously been shown to be effective in oil reservoir simulation problems. This method combines trajectory piecewise linearization (TPWL), in which the solution to a new (test) problem is represented through a linearization around the solution to a previously-simulated (training) problem, with proper orthogonal decomposition (POD), which enables solution states to be expressed in terms of a relatively small number of parameters. We describe the application of POD-TPWL for CO2-water systems simulated using a compositional procedure. Stanford’s Automatic Differentiation-based General Purpose Research Simulator (AD-GPRS) performs the full-order training simulations and provides the output (derivative matrices and system states) required by the POD-TPWL method. A new POD-TPWL capability introduced in this work is the use of horizontal injection wells that operate under rate (rather than bottom-hole pressure) control. Simulation results are presented for CO2 injection into a synthetic aquifer and into a simplified model of the Mount Simon formation. Test cases involve the use of time-varying well controls that differ from those used in training runs. Results of reasonable accuracy are consistently achieved for relevant well quantities. Runtime speedups of around a factor of 370 relative to full- order AD-GPRS simulations are achieved, though the preprocessing needed for POD-TPWL model construction corresponds to the computational requirements for about 2.3 full-order simulation runs. A preliminary treatment for POD-TPWL modeling in which test cases differ from training runs in terms of geological parameters (rather than well controls) is also presented. Results in this case involve only small differences between

  16. Performance of hedging strategies in interval models

    NARCIS (Netherlands)

    Roorda, Berend; Engwerda, Jacob; Schumacher, J.M.

    2005-01-01

    For a proper assessment of risks associated with the trading of derivatives, the performance of hedging strategies should be evaluated not only in the context of the idealized model that has served as the basis of strategy development, but also in the context of other models. In this paper we

  17. Some viewpoints on reference biospheres in Finnish performance assessments

    International Nuclear Information System (INIS)

    Rasilainen, K.; Kattilakoski, E.; Suolanen, V.; Vieno, T.; Vuori, S.

    2002-01-01

    Viewpoints are presented concerning biosphere studies in performance assessments of nuclear waste disposal. The points are based on experiences from several Finnish performance assessments. The latest performance assessment for spent fuel disposal, TILA-99, was considered in the Decision in Principle process for the site selection of the repository. The points given are also based on experiences from participation in international projects dealing with biosphere modelling, for instance BIOMOVS and BIOMASS. (author)

  18. Performance assessment in algebra learning process

    Science.gov (United States)

    Lestariani, Ida; Sujadi, Imam; Pramudya, Ikrar

    2017-12-01

    The purpose of research to describe the implementation of performance assessment on algebra learning process. The subject in this research is math educator of SMAN 1 Ngawi class X. This research includes descriptive qualitative research type. Techniques of data collecting are done by observation method, interview, and documentation. Data analysis technique is done by data reduction, data presentation, and conclusion. The results showed any indication that the steps taken by the educator in applying the performance assessment are 1) preparing individual worksheets and group worksheets, 2) preparing rubric assessments for independent worksheets and groups and 3) making performance assessments rubric to learners’ performance results with individual or groups task.

  19. Machine performance assessment and enhancement for a hexapod machine

    Energy Technology Data Exchange (ETDEWEB)

    Mou, J.I. [Arizona State Univ., Tempe, AZ (United States); King, C. [Sandia National Labs., Livermore, CA (United States). Integrated Manufacturing Systems Center

    1998-03-19

    The focus of this study is to develop a sensor fused process modeling and control methodology to model, assess, and then enhance the performance of a hexapod machine for precision product realization. Deterministic modeling technique was used to derive models for machine performance assessment and enhancement. Sensor fusion methodology was adopted to identify the parameters of the derived models. Empirical models and computational algorithms were also derived and implemented to model, assess, and then enhance the machine performance. The developed sensor fusion algorithms can be implemented on a PC-based open architecture controller to receive information from various sensors, assess the status of the process, determine the proper action, and deliver the command to actuators for task execution. This will enhance a hexapod machine`s capability to produce workpieces within the imposed dimensional tolerances.

  20. Performance assessment of a microsprinkler

    Directory of Open Access Journals (Sweden)

    Edivaldo Lopes Thomaz

    2014-04-01

    Full Text Available Surface hydrological processes are essential to the understanding and prediction of soil erosion. Several equipments are used to measure infiltration rate, runoff and soil loss. However, researchers build their own equipment due to the specific sites where the measurements are performed. This study evaluated the performance of a microsprinkler developed to measure the hydrological processes on unpaved rural roads. The microsprinkler is portable, lightweight, easy to operate, and also low cost. The measured parameters refer to different physical aspects of the rainfall produced as: intensity, drop size, kinetic energy and the simulation area. The microsprinkler was tested at different heights and pressures. The main results obtained: the intensity of simulated rainfall was 71.4 - 148.3 mmh-1, the drop size ranged from 0.3 to 1.2 mm (mean 0.7 mm, the kinetic energy of rainfall varied between 51 and 77% compared with a natural rainfall of similar intensity, and the simulation area had 0.28 - 0.56 m2 (mean 0.40 m2. The parameters obtained in this study are within the limit of others simulators reported in the literature.

  1. Competency Assessment Using Key Performance Indicators

    OpenAIRE

    Elena Alexandra Toader; Laura Brad

    2015-01-01

    The paper proposes a method for computing the scores of the key performance indicators resulted in the competency assessment process. The key performance indicators are estimated considering four performance levels that an IT professional can obtain at the end of the assessment process. We suggest as the best approach for estimating the performance key indicators an online questionnaire filled by 60 employees that work in IT Romanian companies. The results provide evidence that the difference...

  2. Field performance assessment and optimization

    Energy Technology Data Exchange (ETDEWEB)

    Alba, Juan Carlos [Ziff Energy Group (Canada)

    2011-07-01

    Ziff Energy Group is a company with a presence in over 60 countries, where it operates in the oil and gas industry, particularly the heavy oil sector. The aim of this presentation is to show the benefits of benchmarking in the heavy oil industry. Heavy oil is defined as oil with a gravity between 10 and 20 API and a viscosity of 100 to 10,000 cp; resources are distributed through all the continents. Benchmarking consists in analyzing performance, looking for new ways to improve it, and implementing those new methods; benchmarking thus promotes measurement and improvement within a company. However, benchmarking in the heavy oil sector presents challenges, due to the difference of the oil play properties, the different cultures inherent in each company, and the abundance of data. This presentation demonstrated that, despite the challenges, benchmarking is a useful tool for optimizing heavy oil operations.

  3. Firm Sustainability Performance Index Modeling

    Directory of Open Access Journals (Sweden)

    Che Wan Jasimah Bt Wan Mohamed Radzi

    2015-12-01

    Full Text Available The main objective of this paper is to bring a model for firm sustainability performance index by applying both classical and Bayesian structural equation modeling (parametric and semi-parametric modeling. Both techniques are considered to the research data collected based on a survey directed to the China, Taiwan, and Malaysia food manufacturing industry. For estimating firm sustainability performance index we consider three main indicators include knowledge management, organizational learning, and business strategy. Based on the both Bayesian and classical methodology, we confirmed that knowledge management and business strategy have significant impact on firm sustainability performance index.

  4. Performance assessment strategy for low-level waste disposal sites

    International Nuclear Information System (INIS)

    Starmer, R.J.; Deering, L.G.; Weber, M.F.

    1988-01-01

    This paper describes US Nuclear Regulatory Commission (NRC) staff views on predicting the performance of low-level radioactive waste disposal facilities. Under the Atomic Energy Act, as amended, and the Low Level Radioactive Waste Policy Act, as amended, the NRC and Agreement States license land disposal of low-level radioactive waste (LLW) using the requirements in 10 CFR Part 61 or comparable state requirements. The purpose of this paper is to briefly describe regulatory requirements for performance assessment in low-level waste licensing, a strategy for performance assessments to support license applications, and NRC staff licensing evaluation of performance assessments. NRC's current activities in developing a performance assessment methodology will provide an overall systems modeling approach for assessing the performance of LLW disposal facilities. NRC staff will use the methodology to evaluate performance assessments conducted by applicants for LLW disposal facilities. The methodology will be made available to states and other interested parties

  5. The effect of reproductive performance on the dairy cattle herd value assessed by integrating a daily dynamic programming model with a daily Markov chain model.

    Science.gov (United States)

    Kalantari, A S; Cabrera, V E

    2012-10-01

    The objective of this study was to determine the effect of reproductive performance on dairy cattle herd value. Herd value was defined as the herd's average retention payoff (RPO). Individual cow RPO is the expected profit from keeping the cow compared with immediate replacement. First, a daily dynamic programming model was developed to calculate the RPO of all cow states in a herd. Second, a daily Markov chain model was applied to estimate the herd demographics. Finally, the herd value was calculated by aggregating the RPO of all cows in the herd. Cow states were described by 5 milk yield classes (76, 88, 100, 112, and 124% with respect to the average), 9 lactations, 750 d in milk, and 282 d in pregnancy. Five different reproductive programs were studied (RP1 to RP5). Reproductive program 1 used 100% timed artificial insemination (TAI; 42% conception rate for first TAI and 30% for second and later services) and the other programs combined TAI with estrus detection. The proportion of cows receiving artificial insemination after estrus detection ranged from 30 to 80%, and conception rate ranged from 25 to 35%. These 5 reproductive programs were categorized according to their 21-d pregnancy rate (21-d PR), which is an indication of the rate that eligible cows become pregnant every 21 d. The 21-d PR was 17% for RP1, 14% for RP2, 16% for RP3, 18% for RP4, and 20% for RP5. Results showed a positive relationship between 21-d PR and herd value. The most extreme herd value difference between 2 reproductive programs was $77/cow per yr for average milk yield (RP5 - RP2), $13/cow per yr for lowest milk yield (RP5 - RP1), and $160/cow per yr for highest milk yield (RP5 - RP2). Reproductive programs were ranked based on their calculated herd value. With the exception of the best reproductive program (RP5), all other programs showed some level of ranking change according to milk yield. The most dramatic ranking change was observed in RP1, which moved from being the worst ranked

  6. Performance Assessment of Mergers and Acquisitions

    DEFF Research Database (Denmark)

    Wang, Daojuan; Moini, Hamid

    2012-01-01

    Corporate mergers and acquisitions (M&As) have been increasing popular during these decades. However, a majority of research show failure rate (40% - 80%) has not significantly changed. This “success paradox” triggers us to reflect on performance assessment of M&As: how the performance of M...... on the performance measures and benchmarks adopted in M&A research field and the relevant empirical results. We find that the definitions of performance varied in terms of accounting, financial, operational and perceptual metrics. And performance assessment is sensitive to the definition of performance, methodology...

  7. Thermodynamics, data estimation and performance assessment

    International Nuclear Information System (INIS)

    Grenthe, I.

    2002-01-01

    Performance assessment provides a narrative of a system and its development. One may use a literary metaphor; the procedure is like writing a novel where the 'chapters' are the various sub-systems and where both the 'plot' and the 'grammar' are based on scientific and other information, some hard facts and other more or less reliable guesses. I will begin with some general remarks on models, which may provide a useful starting point for what follows. - Models never provide complete descriptions of real systems; they are used to highlight certain aspects of them and to answer 'what-if' questions; - Modelling is an iterative process that provides guidance as to what are important phenomena and what is less relevant for the description of the system and its function; - It is necessary to distinguish between model uncertainties and parameter uncertainties; - It is often better to estimate a quantity for which no data are available than to exclude the particular process where it is needed. Thermodynamics provide not only numerical values for different chemical processes, but more important a theory framework that can be used for the estimation of data. I will not discuss activity coefficient corrections of thermodynamic data, an important area that has already been addressed by Professor Fanghaenel. In the following overview I will be using examples of estimations of different kinds to illustrate what can be accomplished using thermodynamics in combination with chemical theories. (author)

  8. Performance Evaluation of a Dedicated Preclinical PET/CT System for the Assessment of Mineralization Process in a Mouse Model of Atherosclerosis.

    Science.gov (United States)

    Rucher, Guillaume; Cameliere, Lucie; Fendri, Jihene; Abbas, Ahmed; Dupont, Kevin; Kamel, Said; Delcroix, Nicolas; Dupont, Axel; Berger, Ludovic; Manrique, Alain

    2018-04-30

    The purpose of this study was to assess the impact of positron emission tomography/X-ray computed tomography (PET/CT) acquisition and reconstruction parameters on the assessment of mineralization process in a mouse model of atherosclerosis. All experiments were performed on a dedicated preclinical PET/CT system. CT was evaluated using five acquisition configurations using both a tungsten wire phantom for in-plane resolution assessment and a bar pattern phantom for cross-plane resolution. Furthermore, the radiation dose of these acquisition configurations was calculated. The PET system was assessed using longitudinal line sources to determine the optimal reconstruction parameters by measuring central resolution and its coefficient of variation. An in vivo PET study was performed using uremic ApoE -/- , non-uremic ApoE -/- , and control mice to evaluate optimal PET reconstruction parameters for the detection of sodium [ 18 F]fluoride (Na[ 18 F]F) aortic uptake and for quantitative measurement of Na[ 18 F]F bone influx (Ki) with a Patlak analysis. For CT, the use of 1 × 1 and 2 × 2 binning detector mode increased both in-plane and cross-plane resolution. However, resolution improvement (163 to 62 μm for in-plane resolution) was associated with an important radiation dose increase (1.67 to 32.78 Gy). With PET, 3D-ordered subset expectation maximization (3D-OSEM) algorithm increased the central resolution compared to filtered back projection (1.42 ± 0.35 mm vs. 1.91 ± 0.08, p PET resolution for preclinical study (FWHM = 0.98 mm). These PET reconstruction parameters allowed the detection of Na[ 18 F]F aortic uptake in 3/14 ApoE -/- mice and demonstrated a decreased Ki in uremic ApoE -/- compared to non-uremic ApoE -/- and control mice (p PET. In addition, improving the CT resolution was associated with a dramatic radiation dose increase.

  9. Preliminary geohydrologic conceptual model of the Los Medanos region near the Waste Isolation Pilot Plant for the purpose of performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Brinster, K.F. (Science Applications International Corp., Albuquerque, NM (USA))

    1991-01-01

    This report describes a geohydrologic conceptual model of the northern Delaware Basin to be used in modeling three-dimensional, regional ground-water flow for assessing the performance of the Waste Isolation Pilot Plant (WIPP) in the Los Medanos region near Carlsbad, New Mexico. Geochemical and hydrological evidence indicates that flow is transient in the Rustler Formation and the Capitan aquifer in response to changing geologic, hydrologic, and climatic conditions. Before the Pleistocene, ground-water flow in the Rustler Formation was generally eastward, but uneven tilting of the Delaware Basin lowered the regional base level and formed fractures in the evaporitic sequence of rocks approximately parallel to the basin axis. Dissolution along the fractures, coupled with erosion, formed Nash Draw. Also, the drop in base level resulted in an increase in the carrying power of the Pecos River, which began incising the Capitan/aquifer near Carlsbad, New Mexico. Erosion and downcutting released hydraulic pressure that caused a reversal in Rustler ground-water flow direction near the WIPP. Flow in the Rustler west of the WIPP is toward Nash Draw and eventually toward Malaga Bend; flow south of the WIPP is toward Malaga Bend. 126 refs., 70 figs., 18 tabs.

  10. Preliminary geohydrologic conceptual model of the Los Medanos region near the Waste Isolation Pilot Plant for the purpose of performance assessment

    International Nuclear Information System (INIS)

    Brinster, K.F.

    1991-01-01

    This report describes a geohydrologic conceptual model of the northern Delaware Basin to be used in modeling three-dimensional, regional ground-water flow for assessing the performance of the Waste Isolation Pilot Plant (WIPP) in the Los Medanos region near Carlsbad, New Mexico. Geochemical and hydrological evidence indicates that flow is transient in the Rustler Formation and the Capitan aquifer in response to changing geologic, hydrologic, and climatic conditions. Before the Pleistocene, ground-water flow in the Rustler Formation was generally eastward, but uneven tilting of the Delaware Basin lowered the regional base level and formed fractures in the evaporitic sequence of rocks approximately parallel to the basin axis. Dissolution along the fractures, coupled with erosion, formed Nash Draw. Also, the drop in base level resulted in an increase in the carrying power of the Pecos River, which began incising the Capitan/aquifer near Carlsbad, New Mexico. Erosion and downcutting released hydraulic pressure that caused a reversal in Rustler ground-water flow direction near the WIPP. Flow in the Rustler west of the WIPP is toward Nash Draw and eventually toward Malaga Bend; flow south of the WIPP is toward Malaga Bend. 126 refs., 70 figs., 18 tabs

  11. MODELING SUPPLY CHAIN PERFORMANCE VARIABLES

    Directory of Open Access Journals (Sweden)

    Ashish Agarwal

    2005-01-01

    Full Text Available In order to understand the dynamic behavior of the variables that can play a major role in the performance improvement in a supply chain, a System Dynamics-based model is proposed. The model provides an effective framework for analyzing different variables affecting supply chain performance. Among different variables, a causal relationship among different variables has been identified. Variables emanating from performance measures such as gaps in customer satisfaction, cost minimization, lead-time reduction, service level improvement and quality improvement have been identified as goal-seeking loops. The proposed System Dynamics-based model analyzes the affect of dynamic behavior of variables for a period of 10 years on performance of case supply chain in auto business.

  12. Performance assessment of LLW disposal facilities

    International Nuclear Information System (INIS)

    Rogers, V.

    1988-01-01

    The overall performance of a low-level radioactive waste (LLW) disposal facility is determined by the facility design and the site environment. Recently, disposal facilities being considered have included engineered barriers such as concrete vaults or modular concrete canisters. The role that these engineered barriers play in facility performance should be adequately characterized in the performance assessment. The manner in which engineered barriers have been incorporated in performance assessments recently conducted by Rogers and Associates Engineering Corporation (RAE) personnel provides several insights into the method of analyzing engineered barriers and overall disposal facility performance. The overall performance objective is to minimize the radiation dose potentially received by members of the public and disposal facility workers. Consequently, the end point of the RAE performance assessments, completed in the last year, is peak annual doses to members of the critical population group

  13. Hydrological Assessment of Model Performance and Scenario Analyses of Land Use Change and Climate Change in lowlands of Veneto Region (Italy)

    Science.gov (United States)

    Pijl, Anton; Brauer, Claudia; Sofia, Giulia; Teuling, Ryan; Tarolli, Paolo

    2017-04-01

    Growing water-related challenges in lowland areas of the world call for good assessment of our past and present actions, in order to guide our future decisions. The novel Wageningen Lowland Runoff Simulator (WALRUS; Brauer et al., 2014) was developed to simulate hydrological processes and has showed promising performance in recent studies in the Netherlands. Here the model was applied to a coastal basin of 2800 ha in the Veneto Region (northern Italy) to test model performance and evaluate scenario analyses of land use change and climate change. Located partially below sea-level, the reclaimed area is facing persistent land transformation and climate change trends, which alter not only the processes in the catchment but also the demands from it (Tarolli and Sofia, 2016). Firstly results of the calibration (NSE = 0.77; year simulation, daily resolution) and validation (NSE = 0.53; idem) showed that the model is able to reproduce the dominant hydrological processes of this lowland area (e.g. discharge and groundwater fluxes). Land use scenarios between 1951 and 2060 were constructed using demographic models, supported by orthographic interpretation techniques. Climate scenarios were constructed by historical records and future projections by COSMO-CLM regional climate model (Rockel et al., 2008) under the RCP4.5 pathway. WALRUS simulations showed that the land use changes result in a wetter catchment with more discharge, and the climatic changes cause more extremes with longer droughts and stronger rain events. These changes combined show drier summers (-33{%} rainfall, +27{%} soil moisture deficit) and wetter (+13{%} rainfall) and intenser (+30{%} rain intensity) autumn and winters in the future. The simulated discharge regime -particularly peak flow- follows these polarising trends, in good agreement with similar studies in the geographical zone (e.g. Vezzoli et al., 2015). This will increase the pressure on the fully-artificial drainage and agricultural systems

  14. Performance assessment for low-level radioactive waste disposal

    International Nuclear Information System (INIS)

    Cook, J.R.; Hsu, R.H.; Wilhite, E.L.; Yu, A.D.

    1996-01-01

    In October 1994 the Savannah River Site became the first US DOE complex to use concrete vaults to dispose of low-level radioactive solid waste and better prevent soil and groundwater contamination. This article describes the design and gives a performance assessment of the vaults. Topics include the following: Performance objectives; scope; the performance assessment process-assemble a multidisciplinary working group; collect available data; define credible pathways/scenarios; develop conceptual models; conduct screening and detailed model calculations; assess sensitivity/uncertainty; integrate and interpret results; report. 9 figs., 3 tabs

  15. Modelling soil and soil to plant transfer processes of radionuclides and toxic chemicals at long time scales for performance assessment of Radwaste disposal

    Science.gov (United States)

    Albrecht, Achim; Miquel, Stephan

    2015-04-01

    Performance assessments for surface nuclear waste disposal facilities require simulation of transfer processes from the waste canisters to a reference group living near-by. Such simulations need to be extended over several hundred to hundred thousand years, depending on waste type, restraining possibilities to represent short term system complexity and variability. Related modelling can be simplified as long as processes are represented conservatively with assessment endpoints estimated larger compared to more realistic modelling approaches. The indicators are doses for radionuclides (RN) and risk factors for toxic chemicals (TC, i.e. heavy metals, nitrate). We discuss a new simulation tool (SCM-Andra-multilayer-model, SAMM) that, among others, allows to model situations where RN/TC move through a soil profile characterised by temporal undersaturation and root growth (soil-plant subsystem of the biosphere model compared to the adjacent saturated geosphere). SAMM describes all relevant transfer and reaction processes (advection, diffusion, root transport, radioactive decay, chemical reactions incl. sorption - desorption) using well known differential equations solved numerically within MATLAB with scenario description and parameterisation defined in Excel sheets. With this conservative approach in mind, we apply global parameters for which the solid-solution (Kd) or soil-to-plant (TF) distribution coefficients are the most relevant. Empirical data are available for homogeneous situations, such as one compartment pot experiments, but rare for entire soil profiles. Similarly soil hydrology, in particular upward and downward advective fluxes are modelled using an empirical approach solely based on key soil hydrological parameters (precipitation, evapotranspiration, irrigation, water table level) and the soil porosity. Variability of soil hydrology in space and time, likely to change drastically even on hourly bases (i.e. intense precipitation event) or within a single

  16. Photovoltaic performance models - A report card

    Science.gov (United States)

    Smith, J. H.; Reiter, L. R.

    1985-01-01

    Models for the analysis of photovoltaic (PV) systems' designs, implementation policies, and economic performance, have proliferated while keeping pace with rapid changes in basic PV technology and extensive empirical data compiled for such systems' performance. Attention is presently given to the results of a comparative assessment of ten well documented and widely used models, which range in complexity from first-order approximations of PV system performance to in-depth, circuit-level characterizations. The comparisons were made on the basis of the performance of their subsystem, as well as system, elements. The models fall into three categories in light of their degree of aggregation into subsystems: (1) simplified models for first-order calculation of system performance, with easily met input requirements but limited capability to address more than a small variety of design considerations; (2) models simulating PV systems in greater detail, encompassing types primarily intended for either concentrator-incorporating or flat plate collector PV systems; and (3) models not specifically designed for PV system performance modeling, but applicable to aspects of electrical system design. Models ignoring subsystem failure or degradation are noted to exclude operating and maintenance characteristics as well.

  17. Overuse Injury Assessment Model

    National Research Council Canada - National Science Library

    Stuhmiller, James H; Shen, Weixin; Sih, Bryant

    2005-01-01

    .... Previously, we developed a preliminary model that predicted the stress fracture rate and used biomechanical modeling, nonlinear optimization for muscle force, and bone structural analysis to estimate...

  18. Relative performance of empirical and physical models in assessing the seasonal and annual glacier surface mass balance of Saint-Sorlin Glacier (French Alps

    Directory of Open Access Journals (Sweden)

    M. Réveillet

    2018-04-01

    Full Text Available This study focuses on simulations of the seasonal and annual surface mass balance (SMB of Saint-Sorlin Glacier (French Alps for the period 1996–2015 using the detailed SURFEX/ISBA-Crocus snowpack model. The model is forced by SAFRAN meteorological reanalysis data, adjusted with automatic weather station (AWS measurements to ensure that simulations of all the energy balance components, in particular turbulent fluxes, are accurately represented with respect to the measured energy balance. Results indicate good model performance for the simulation of summer SMB when using meteorological forcing adjusted with in situ measurements. Model performance however strongly decreases without in situ meteorological measurements. The sensitivity of the model to meteorological forcing indicates a strong sensitivity to wind speed, higher than the sensitivity to ice albedo. Compared to an empirical approach, the model exhibited better performance for simulations of snow and firn melting in the accumulation area and similar performance in the ablation area when forced with meteorological data adjusted with nearby AWS measurements. When such measurements were not available close to the glacier, the empirical model performed better. Our results suggest that simulations of the evolution of future mass balance using an energy balance model require very accurate meteorological data. Given the uncertainties in the temporal evolution of the relevant meteorological variables and glacier surface properties in the future, empirical approaches based on temperature and precipitation could be more appropriate for simulations of glaciers in the future.

  19. Relative performance of empirical and physical models in assessing the seasonal and annual glacier surface mass balance of Saint-Sorlin Glacier (French Alps)

    Science.gov (United States)

    Réveillet, Marion; Six, Delphine; Vincent, Christian; Rabatel, Antoine; Dumont, Marie; Lafaysse, Matthieu; Morin, Samuel; Vionnet, Vincent; Litt, Maxime

    2018-04-01

    This study focuses on simulations of the seasonal and annual surface mass balance (SMB) of Saint-Sorlin Glacier (French Alps) for the period 1996-2015 using the detailed SURFEX/ISBA-Crocus snowpack model. The model is forced by SAFRAN meteorological reanalysis data, adjusted with automatic weather station (AWS) measurements to ensure that simulations of all the energy balance components, in particular turbulent fluxes, are accurately represented with respect to the measured energy balance. Results indicate good model performance for the simulation of summer SMB when using meteorological forcing adjusted with in situ measurements. Model performance however strongly decreases without in situ meteorological measurements. The sensitivity of the model to meteorological forcing indicates a strong sensitivity to wind speed, higher than the sensitivity to ice albedo. Compared to an empirical approach, the model exhibited better performance for simulations of snow and firn melting in the accumulation area and similar performance in the ablation area when forced with meteorological data adjusted with nearby AWS measurements. When such measurements were not available close to the glacier, the empirical model performed better. Our results suggest that simulations of the evolution of future mass balance using an energy balance model require very accurate meteorological data. Given the uncertainties in the temporal evolution of the relevant meteorological variables and glacier surface properties in the future, empirical approaches based on temperature and precipitation could be more appropriate for simulations of glaciers in the future.

  20. Development of the Conceptual Models for Chemical Conditions and Hydrology Used in the 1996 Performance Assessment for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    LARSON, KURT W.

    2000-01-01

    The Waste Isolation Pilot Plant (WIPP) is a US Department of Energy (DOE) facility for the permanent disposal of defense-related transuranic (TRU) waste. US Environmental Protection Agency (EPA) regulations specify that the DOE must demonstrate on a sound basis that the WIPP disposal system will effectively contain long-lived alpha-emitting radionuclides within its boundaries for 10,000 years following closure. In 1996, the DOE submitted the ''40 CFR Part 191 Compliance Certification Application for the Waste Isolation Pilot Plant'' (CCA) to the EPA. The CCA proposed that the WIPP site complies with EPA's regulatory requirements. Contained within the CCA are descriptions of the scientific research conducted to characterize the properties of the WIPP site and the probabilistic performance assessment (PA) conducted to predict the containment properties of the WIPP disposal system. In May 1998, the EPA certified that the TRU waste disposal at the WIPP complies with its regulations. Waste disposal operations at WIPP commenced on March 28, 1999. The 1996 WIPP PA model of the disposal system included conceptual and mathematical representations of key hydrologic and geochemical processes. These key processes were identified over a 22-year period involving data collection, data interpretation, computer models, and sensitivity studies to evaluate the importance of uncertainty and of processes that were difficult to evaluate by other means. Key developments in the area of geochemistry were the evaluation of gas generation mechanisms in the repository; development of a model of chemical conditions in the repository and actinide concentrations in brine; selecting MgO backfill and demonstrating its effects experimentally; and determining the chemical retardation capability of the Culebra. Key developments in the area of hydrology were evacuating the potential for groundwater to dissolve the Salado Formation (the repository host formation), development of a regional model for

  1. Development of the Conceptual Models for Chemical Conditions and Hydrology Used in the 1996 Performance Assessment for the Waste Isolation Pilot Plant

    Energy Technology Data Exchange (ETDEWEB)

    LARSON, KURT W

    2000-05-24

    The Waste Isolation Pilot Plant (WIPP) is a US Department of Energy (DOE) facility for the permanent disposal of defense-related transuranic (TRU) waste. US Environmental Protection Agency (EPA) regulations specify that the DOE must demonstrate on a sound basis that the WIPP disposal system will effectively contain long-lived alpha-emitting radionuclides within its boundaries for 10,000 years following closure. In 1996, the DOE submitted the ''40 CFR Part 191 Compliance Certification Application for the Waste Isolation Pilot Plant'' (CCA) to the EPA. The CCA proposed that the WIPP site complies with EPA's regulatory requirements. Contained within the CCA are descriptions of the scientific research conducted to characterize the properties of the WIPP site and the probabilistic performance assessment (PA) conducted to predict the containment properties of the WIPP disposal system. In May 1998, the EPA certified that the TRU waste disposal at the WIPP complies with its regulations. Waste disposal operations at WIPP commenced on March 28, 1999. The 1996 WIPP PA model of the disposal system included conceptual and mathematical representations of key hydrologic and geochemical processes. These key processes were identified over a 22-year period involving data collection, data interpretation, computer models, and sensitivity studies to evaluate the importance of uncertainty and of processes that were difficult to evaluate by other means. Key developments in the area of geochemistry were the evaluation of gas generation mechanisms in the repository; development of a model of chemical conditions in the repository and actinide concentrations in brine; selecting MgO backfill and demonstrating its effects experimentally; and determining the chemical retardation capability of the Culebra. Key developments in the area of hydrology were evacuating the potential for groundwater to dissolve the Salado Formation (the repository host formation), development

  2. Assessing the Effectiveness of a Hybrid-Flipped Model of Learning on Fluid Mechanics Instruction: Overall Course Performance, Homework, and Far- and Near-Transfer of Learning

    Science.gov (United States)

    Harrison, David J.; Saito, Laurel; Markee, Nancy; Herzog, Serge

    2017-01-01

    To examine the impact of a hybrid-flipped model utilising active learning techniques, the researchers inverted one section of an undergraduate fluid mechanics course, reduced seat time, and engaged in active learning sessions in the classroom. We compared this model to the traditional section on four performance measures. We employed a propensity…

  3. Personality, Assessment Methods and Academic Performance

    Science.gov (United States)

    Furnham, Adrian; Nuygards, Sarah; Chamorro-Premuzic, Tomas

    2013-01-01

    This study examines the relationship between personality and two different academic performance (AP) assessment methods, namely exams and coursework. It aimed to examine whether the relationship between traits and AP was consistent across self-reported versus documented exam results, two different assessment techniques and across different…

  4. Performance Assessment Framework for Private Finance Initiative Projects in Malaysia

    Directory of Open Access Journals (Sweden)

    Lop Nor Suzila

    2016-01-01

    Full Text Available Private Finance Initiative (PFI is viewed as restructuring the previous privatisation concept in delivering value for money for the Malaysian public infrastructure. Among the restructuring efforts in the privatisation is specifying the standard assessment of private concessionaires’ performance through the execution of key performance indicators (KPIs where the private concessionaires’ performance is benchmarked against the government’s standard. KPIs have served as useful tools in assessing performance of PFI projects. However, there is still lacking on determination methods performed to define and measure this KPIs and the absence of guidelines or a framework is also an issue in the implementation of the PFI procurement in Malaysia. Therefore, the objectives of this paper is to investigate the notion of performance assessment model approaches globally (i.e. UK, China, Australia, Serbia and Malaysia and to identify direction for PFI performance assessment tools (KPIs to be practiced in Malaysia. Based on the consideration of these models, this research paper propose an initial framework of performance assessment for PFI projects in Malaysia. The framework is deliberate to cover the performance of PFI at the operation and maintenance phase. The outcomes of this paper can serve as a theoretical base for the development of comprehensive and effective performance assessment for PFI projects in Malaysia.

  5. Construct Validity of Three Clerkship Performance Assessments

    Science.gov (United States)

    Lee, Ming; Wimmers, Paul F.

    2010-01-01

    This study examined construct validity of three commonly used clerkship performance assessments: preceptors' evaluations, OSCE-type clinical performance measures, and the NBME [National Board of Medical Examiners] medicine subject examination. Six hundred and eighty-six students taking the inpatient medicine clerkship from 2003 to 2007…

  6. Physician Performance Assessment: Prevention of Cardiovascular Disease

    Science.gov (United States)

    Lipner, Rebecca S.; Weng, Weifeng; Caverzagie, Kelly J.; Hess, Brian J.

    2013-01-01

    Given the rising burden of healthcare costs, both patients and healthcare purchasers are interested in discerning which physicians deliver quality care. We proposed a methodology to assess physician clinical performance in preventive cardiology care, and determined a benchmark for minimally acceptable performance. We used data on eight…

  7. Assessing irrigation performance by using remote sensing

    NARCIS (Netherlands)

    Bandara, K.M.P.S.

    2006-01-01

    Keywords: Performance indicators, performance assessment, diagnostic approach, SEBAL, target level, grain yield, water productivity, error estimation, spatio-temporal resolution.

    In

  8. Conceptual framework for performance assessment: competency, competence and performance in the context of assessments in healthcare--deciphering the terminology.

    Science.gov (United States)

    Khan, Kamran; Ramachandran, Sankaranarayanan

    2012-01-01

    The definitions of performance, competence and competency are not very clear in the literature. The assessment of performance and the selection of tools for this purpose depend upon a deep understanding of each of the above terms and the factors influencing performance. In this article, we distinguish between competence and competency and explain the relationship of competence and performance in the light of the Dreyfus model of skills acquisition. We briefly critique the application of the principles described by Miller to the modern assessment tools and distinguish between assessment of actual performance in workplace settings and the observed performance, demonstrated by the candidates in the workplace or simulated settings. We describe a modification of the Dreyfus model applicable to assessments in healthcare and propose a new model for the assessment of performance and performance rating scale (PRS) based on this model. We propose that the use of adapted versions of this PRS will result in benchmarking of performance and allowing the candidates to track their progression of skills in various areas of clinical practice.

  9. Integrated STEM Assessment Model

    Science.gov (United States)

    Bicer, Ali; Capraro, Robert M.; Capraro, Mary M.

    2017-01-01

    Previous research identified a strong correlation between mathematics and science performance albeit for small samples of students. Even though there was a high correlation between mathematics and science performance, researchers examining students' STEM achievement investigated mathematics and science achievement separately. The present study…

  10. Overuse Injury Assessment Model

    National Research Council Canada - National Science Library

    Stuhmiller, James H; Shen, Weixin; Sih, Bryant

    2005-01-01

    ... bone stresses and strains from kinematic and ground reaction force measures. We broaden the work to address not only the overuse injuries, but the performance enhancement and metabolic demands associated with training...

  11. Assessment of Student Music Performances Using Deep Neural Networks

    Directory of Open Access Journals (Sweden)

    Kumar Ashis Pati

    2018-03-01

    Full Text Available Music performance assessment is a highly subjective task often relying on experts to gauge both the technical and aesthetic aspects of the performance from the audio signal. This article explores the task of building computational models for music performance assessment, i.e., analyzing an audio recording of a performance and rating it along several criteria such as musicality, note accuracy, etc. Much of the earlier work in this area has been centered around using hand-crafted features intended to capture relevant aspects of a performance. However, such features are based on our limited understanding of music perception and may not be optimal. In this article, we propose using Deep Neural Networks (DNNs for the task and compare their performance against a baseline model using standard and hand-crafted features. We show that, using input representations at different levels of abstraction, DNNs can outperform the baseline models across all assessment criteria. In addition, we use model analysis techniques to further explain the model predictions in an attempt to gain useful insights into the assessment process. The results demonstrate the potential of using supervised feature learning techniques to better characterize music performances.

  12. A statistical model for predicting muscle performance

    Science.gov (United States)

    Byerly, Diane Leslie De Caix

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

  13. Irrigation in dose assessments models

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, Ulla; Barkefors, Catarina [Studsvik RadWaste AB, Nykoeping (Sweden)

    2004-05-01

    SKB has carried out several safety analyses for repositories for radioactive waste, one of which was SR 97, a multi-site study concerned with a future deep bedrock repository for high-level waste. In case of future releases due to unforeseen failure of the protective multiple barrier system, radionuclides may be transported with groundwater and may reach the biosphere. Assessments of doses have to be carried out with a long-term perspective. Specific models are therefore employed to estimate consequences to man. It has been determined that the main pathway for nuclides from groundwater or surface water to soil is via irrigation. Irrigation may cause contamination of crops directly by e.g. interception or rain-splash, and indirectly via root-uptake from contaminated soil. The exposed people are in many safety assessments assumed to be self-sufficient, i.e. their food is produced locally where the concentration of radionuclides may be the highest. Irrigation therefore plays an important role when estimating consequences. The present study is therefore concerned with a more extensive analysis of the role of irrigation for possible future doses to people living in the area surrounding a repository. Current irrigation practices in Sweden are summarised, showing that vegetables and potatoes are the most common crops for irrigation. In general, however, irrigation is not so common in Sweden. The irrigation model used in the latest assessments is described. A sensitivity analysis is performed showing that, as expected, interception of irrigation water and retention on vegetation surfaces are important parameters. The parameters used to describe this are discussed. A summary is also given how irrigation is proposed to be handled in the international BIOMASS (BIOsphere Modelling and ASSessment) project and in models like TAME and BIOTRAC. Similarities and differences are pointed out. Some numerical results are presented showing that surface contamination in general gives the

  14. Irrigation in dose assessments models

    International Nuclear Information System (INIS)

    Bergstroem, Ulla; Barkefors, Catarina

    2004-05-01

    SKB has carried out several safety analyses for repositories for radioactive waste, one of which was SR 97, a multi-site study concerned with a future deep bedrock repository for high-level waste. In case of future releases due to unforeseen failure of the protective multiple barrier system, radionuclides may be transported with groundwater and may reach the biosphere. Assessments of doses have to be carried out with a long-term perspective. Specific models are therefore employed to estimate consequences to man. It has been determined that the main pathway for nuclides from groundwater or surface water to soil is via irrigation. Irrigation may cause contamination of crops directly by e.g. interception or rain-splash, and indirectly via root-uptake from contaminated soil. The exposed people are in many safety assessments assumed to be self-sufficient, i.e. their food is produced locally where the concentration of radionuclides may be the highest. Irrigation therefore plays an important role when estimating consequences. The present study is therefore concerned with a more extensive analysis of the role of irrigation for possible future doses to people living in the area surrounding a repository. Current irrigation practices in Sweden are summarised, showing that vegetables and potatoes are the most common crops for irrigation. In general, however, irrigation is not so common in Sweden. The irrigation model used in the latest assessments is described. A sensitivity analysis is performed showing that, as expected, interception of irrigation water and retention on vegetation surfaces are important parameters. The parameters used to describe this are discussed. A summary is also given how irrigation is proposed to be handled in the international BIOMASS (BIOsphere Modelling and ASSessment) project and in models like TAME and BIOTRAC. Similarities and differences are pointed out. Some numerical results are presented showing that surface contamination in general gives the

  15. Ecosystem Model Skill Assessment. Yes We Can!

    Science.gov (United States)

    Olsen, Erik; Fay, Gavin; Gaichas, Sarah; Gamble, Robert; Lucey, Sean; Link, Jason S.

    2016-01-01

    Need to Assess the Skill of Ecosystem Models Accelerated changes to global ecosystems call for holistic and integrated analyses of past, present and future states under various pressures to adequately understand current and projected future system states. Ecosystem models can inform management of human activities in a complex and changing environment, but are these models reliable? Ensuring that models are reliable for addressing management questions requires evaluating their skill in representing real-world processes and dynamics. Skill has been evaluated for just a limited set of some biophysical models. A range of skill assessment methods have been reviewed but skill assessment of full marine ecosystem models has not yet been attempted. Northeast US Atlantis Marine Ecosystem Model We assessed the skill of the Northeast U.S. (NEUS) Atlantis marine ecosystem model by comparing 10-year model forecasts with observed data. Model forecast performance was compared to that obtained from a 40-year hindcast. Multiple metrics (average absolute error, root mean squared error, modeling efficiency, and Spearman rank correlation), and a suite of time-series (species biomass, fisheries landings, and ecosystem indicators) were used to adequately measure model skill. Overall, the NEUS model performed above average and thus better than expected for the key species that had been the focus of the model tuning. Model forecast skill was comparable to the hindcast skill, showing that model performance does not degenerate in a 10-year forecast mode, an important characteristic for an end-to-end ecosystem model to be useful for strategic management purposes. Skill Assessment Is Both Possible and Advisable We identify best-practice approaches for end-to-end ecosystem model skill assessment that would improve both operational use of other ecosystem models and future model development. We show that it is possible to not only assess the skill of a complicated marine ecosystem model, but that

  16. Performance assessment modelling for the geological siting regions for the L/ILW and HLW repositories in the context of the Swiss site selection plan - 59306

    International Nuclear Information System (INIS)

    Poller, Andreas; Schneider, Juerg W.; Zuidema, Piet; Holocher, Johannes; Mayer, Gerhard

    2012-01-01

    In Switzerland, the Nuclear Energy Law requires the disposal of all radioactive waste in deep geological repositories. The procedure for selecting the repository sites is defined in the Sectoral Plan for Deep Geological Repositories and consists of three stages. In Stage 1, the National Cooperative for the Disposal of Radioactive Waste (Nagra) proposed geological siting regions based on criteria relating to safety and engineering feasibility. As part of Stage 2, Nagra has to select at least one site within each siting region, to carry out a provisional safety analysis for each site and a safety-based comparison of the sites. In order to achieve these objectives, the state of knowledge of the geological conditions in the siting regions has to be sufficient to perform the provisional safety analyses. In October 2010, Nagra submitted a report which documents Nagra's technical-scientific assessment of this precondition, based on a comprehensive list of processes and parameters relevant for safety and engineering feasibility. A part of this assessment consists of test calculations for the provisional safety analyses. This paper summarizes how the numerous test calculations have been identified, how the concepts of radionuclide release from the repository are implemented into numerical codes and how input data and results are organized in order to ensure transparency and traceability. In preparation for the provisional safety analyses in Stage 2 of the Swiss Sectoral Plan for Deep Geological Repositories, Nagra compiled all existing information on the proposed siting regions from many different sources and evaluated the overall state of knowledge with a formal analysis of which processes and parameters are relevant for long-term safety and engineering feasibility (Nagra 2010). The analysis was partly based on a large number of test calculations for the provisional safety analysis which were derived from the requirements for the provisional safety analyses specified by

  17. Overuse Injury Assessment Model

    Science.gov (United States)

    2006-03-01

    bones in celiac disease patients." Am J Gastroenterol 98(2): 382-390. Ferretti, J. L. 1997. "Noninvasive Assessment of Bone Architecture and...altered gait pretest anthropometry diet and nutrition genetics endocrine status and hormones bone disease (pathology) age initial bone health state...and between subjects can be expected. Consequently large numbers of subject are required to obtain statistically significant results. Even with

  18. Overuse Injury Assessment Model

    Science.gov (United States)

    2007-08-01

    Training and Doctrine Command) personnel. Research User: Interested in performance and injury outcomes from the individual level to the group...576. Nonaka, K., Fukuda , S., Aoki, K., Yoshida, T., & Ohya, K. (2006). "Regional distinctions in cortical bone mineral density measured by pQCT can

  19. Modelagem para avaliação de desempenho ambiental em operações de manufatura Modelling for environmental performance assessment in manufacturing operations

    Directory of Open Access Journals (Sweden)

    Miguel Afonso Sellitto

    2010-01-01

    Full Text Available O objetivo deste artigo foi apresentar e testar um método de construção de modelos para a mensuração de desempenho ambiental em operações de manufatura. O método de pesquisa foi o estudo de caso múltiplo. O desempenho ambiental de uma operação de manufatura foi tratado como uma grandeza intangível, composta por cinco construtos latentes: emissões atmosféricas; efluentes líquidos; resíduos sólidos; uso de recursos naturais e gestão interna; e atendimento a legislações e certificações. Os quatro primeiros são de impacto direto, enquanto que o último foi considerado condição intermediária e necessária para os demais. Os significados dos construtos foram apreendidos por indicadores e mensurados qualitativamente por questionários respondidos por gestores de cinco operações: operação avícola, fabricação mecânica, fabricação de materiais elétricos, fabricação de rações e estamparia de aço. Os resultados foram estudados e comparados e forneceram subsídios para a eventual reformulação de estratégias de ação ambientais inseridas nas estratégias de operação das empresas.This paper presents and tests a method for building models to measure environmental performance in manufacturing operations. The research method was the multiple case study. Environmental performance of a manufacturing operation was treated as an intangible variant, composed of five latent constructs: atmospheric emissions, liquid effluents, solid waste, natural resources employment and management and legal requirements and certification compliances. The first four have direct impact on the environment and the last is accepted as a priority and necessary condition for the others. The meaning of the constructs was appraised by indicators and assessed by questionnaires answered by managers from five operations: chicken egg production, mechanical manufacture, electrical goods manufacture, animal food manufacture and steel stamping. The

  20. Performance success from self-assessments

    International Nuclear Information System (INIS)

    Hughes, G.

    1996-01-01

    This paper provides information on and successes of self-assessments completed at the Callaway plant. It stresses the vital needs and substantial benefits from these continual self-improvement efforts. The Callaway plant staff use a variety of methods and techniques to do self-assessments with the focus on performance outcomes. Self-assessments help Callaway focus on the priority issues and direct resources properly. Callaway's success has been due to this learning culture. The Callaway plant is a Westinghouse four-loop plant in the state of Missouri and has been operational since 1984

  1. Integrated Environmental Assessment Modelling

    Energy Technology Data Exchange (ETDEWEB)

    Guardanz, R.; Gimeno, B. S.; Bermejo, V.; Elvira, S.; Martin, F.; Palacios, M.; Rodriguez, E.; Donaire, I. [Ciemat, Madrid (Spain)

    2000-07-01

    This report describes the results of the Spanish participation in the project Coupling CORINAIR data to cost-effect emission reduction strategies based on critical threshold. (EU/LIFE97/ENV/FIN/336). The subproject has focused on three tasks. Develop tools to improve knowledge on the spatial and temporal details of emissions of air pollutants in Spain. Exploit existing experimental information on plant response to air pollutants in temperate ecosystem and Integrate these findings in a modelling framework that can asses with more accuracy the impact of air pollutants to temperate ecosystems. The results obtained during the execution of this project have significantly improved the models of the impact of alternative emission control strategies on ecosystems and crops in the Iberian Peninsula. (Author) 375 refs.

  2. Assessing the performance of two models on calculating maize actual evapotranspiration in a semi-humid and drought-prone region of China

    Science.gov (United States)

    Wang, J.; Wang, J. L.; Zhao, C. X.; McGiffen, M. E.; Liu, J. B.; Wang, G. D.

    2018-02-01

    The two-step and one-step models for calculating evapotranspiration of maize were evaluated in a semi-humid and drought-prone region of northern China. Data were collected in the summers of 2013 and 2014 to determine relative model accuracy in calculating maize evaopotranspiration. The two-step model predicted daily evaoptranspiration with crop coefficients proposed by FAO and crop coefficient calibrated by local field data; the one-step model predicted daily evapotranspiration with coefficients derived by other researcher and coefficients calibrated by local field data. The predicted daily evapotranspiration in 2013 and 2014 growing seasons with the above two different models was both compared with the observed evapotranspiration with eddy covariance method. Furthermore, evapotranspiration in different growth stages of 2013 and 2014 maize growing seasons was predicted using the models with the local calibrated coefficients. The results indicated that calibration of models was necessary before using them to predict daily evapotranspiration. The model with the calibrated coefficients performed better with higher coefficient of determination and index of agreement and lower mean absolute error and root mean square error than before. And the two-step model better predicted daily evapotranspiration than the one-step model in our experimental field. Nevertheless, as to prediction ET of different growth stages, there still had some uncertainty when predicting evapotranspiration in different year. So the comparisons suggested that model prediction of crop evapotranspiration was practical, but requires calibration and validation with more data. Thus, considerable improvement is needed for these two models to be practical in predicting evapotranspiration for maize and other crops, more field data need to be measured, and an in-depth study still needs to be continued.

  3. Dehydration: physiology, assessment, and performance effects.

    Science.gov (United States)

    Cheuvront, Samuel N; Kenefick, Robert W

    2014-01-01

    This article provides a comprehensive review of dehydration assessment and presents a unique evaluation of the dehydration and performance literature. The importance of osmolality and volume are emphasized when discussing the physiology, assessment, and performance effects of dehydration. The underappreciated physiologic distinction between a loss of hypo-osmotic body water (intracellular dehydration) and an iso-osmotic loss of body water (extracellular dehydration) is presented and argued as the single most essential aspect of dehydration assessment. The importance of diagnostic and biological variation analyses to dehydration assessment methods is reviewed and their use in gauging the true potential of any dehydration assessment method highlighted. The necessity for establishing proper baselines is discussed, as is the magnitude of dehydration required to elicit reliable and detectable osmotic or volume-mediated compensatory physiologic responses. The discussion of physiologic responses further helps inform and explain our analysis of the literature suggesting a ≥ 2% dehydration threshold for impaired endurance exercise performance mediated by volume loss. In contrast, no clear threshold or plausible mechanism(s) support the marginal, but potentially important, impairment in strength, and power observed with dehydration. Similarly, the potential for dehydration to impair cognition appears small and related primarily to distraction or discomfort. The impact of dehydration on any particular sport skill or task is therefore likely dependent upon the makeup of the task itself (e.g., endurance, strength, cognitive, and motor skill). © 2014 American Physiological Society.

  4. Questioning the Technical Quality of Performance Assessment.

    Science.gov (United States)

    Baker, Eva L.

    1993-01-01

    Ongoing research finds that alternatives to formal tests carry hidden costs and require trade-offs. National Center for Research on Evaluation, Standards, and Student Testing (CRESST) is studying how performance assessments work so that they may be designed to help students reach their highest potential. This article raises priority questions,…

  5. Performance assessment of indigenously developed FBG strain ...

    Indian Academy of Sciences (India)

    Use of FBG sensors for real time health monitoring of various civil engineering structures is well-established in western world since last decade, whereas in the Indian context this technology is still in a nascent stage. In this paper, performance assessment of indigenously developed FBG sensors for the application of health ...

  6. The Visible Hand of Research Performance Assessment

    Science.gov (United States)

    Hamann, Julian

    2016-01-01

    Far from allowing a governance of universities by the invisible hand of market forces, research performance assessments do not just measure differences in research quality, but yield themselves visible symptoms in terms of a stratification and standardization of disciplines. The article illustrates this with a case study of UK history departments…

  7. Assessing the Performance of Business Unit Managers

    NARCIS (Netherlands)

    Bouwens, J.F.M.G.; van Lent, L.A.G.M.

    2006-01-01

    Using a sample of 140 managers, we investigate the use of various performance metrics in determining the periodic assessment, bonus decisions, and career paths of business unit managers.We show that the weight on accounting return measures is associated with the authority of these managers, and we

  8. An overview of performance assessment methodology

    International Nuclear Information System (INIS)

    Hongnian Jow

    2010-01-01

    The definition of performance assessment (PA) within the context of a geologic repository program is a post-closure safety assessment; a system analysis of hazards associated with the facility and the ability of the site and the design of the facility to provide for the safety functions. For the last few decades, PA methodology bas been developed and applied to different waste disposal programs around the world. PA has been used in the safety analyses for waste disposal repositories for low-level waste, intermediate level waste, and high-level waste including spent nuclear fuels. This paper provides an overview of the performance assessment methodology and gives examples of its applications for the Yucca Mountain Project. (authors)

  9. Total System Performance Assessment: Enhanced Design Alternative IV

    Energy Technology Data Exchange (ETDEWEB)

    P.D. Mattie

    1999-06-23

    The purpose of this calculation is to document total system performance assessment modeling of Enhanced Design Alternative (EDA) Feature IV. Total System Performance Assessment (TSPA) calculations for EDA IV are based on the TSPA-VA Base Case which has been modified with a quartz sand invert, quartz sand backfill, line loading and 21 PWR waste packages that have 2-cm thick titanium grade 7 corrosion resistant material (CRM) drip shields that are placed over a 30 cm thick carbon steel (A5 16) waste package with an integral filler material (CRWMS M&O 1999a & 1999b). This document details the changes and assumptions made to the VA reference Performance Assessment Model (CRWMS M&O 1998a) to incorporate the design changes detailed for EDA IV. The performance measure for this evaluation is the expected value dose-rate history at 20 km from the repository boundary.

  10. The effects of performance-based assessment criteria on student performance and self-assessment skills

    NARCIS (Netherlands)

    Fastré, Greet; Van der Klink, Marcel; Van Merriënboer, Jeroen

    2010-01-01

    Fastré, G. M. J., Van der Klink, M. R., & Van Merriënboer, J. J. G. (2010). The effects of performance-based assessment criteria on student performance and self-assessment skills. Advances in Health Science Education, 15(4), 517-532.

  11. Development of Integrated Assessment Technology of Risk and Performance

    International Nuclear Information System (INIS)

    Yang, Jun Eon; Kang, Dae Il; Kang, Hyun Gook

    2010-04-01

    The main idea and contents are summarized as below 1) Development of new risk/performance assessment system innovating old labor-intensive risk assessment structure - New consolidated risk assessment technology from various hazard(flood, fire, seismic in NPP) - BOP model development for performance monitoring - Consolidated risk/performance management system for consistency and efficiency of NPP 2) Resolution technology for pending issues in PSA - Base technology for PSA of digital I and C system - Base technology for seismic PSA reflecting domestic seismic characteristics and aging effect - Uncertainty reduction technology for level 2 PSA and best estimation of containment failure frequency 3) Next generation risk/performance assessment technology - Human-induced error reduction technology for efficient operation of a NPP

  12. The Grimsel radionuclide migration experiment - a contribution to raising confidence in the validity of solute transport models used in performance assessment

    International Nuclear Information System (INIS)

    Frick, U.

    1995-01-01

    The safety assessment of radioactive waste repositories is to provide confidence that the predictive models utilized are applicable for the specific repository systems. Nagra has carried out radionuclide migration experiments at the Grimsel underground test site (Switzerland) for testing of currently used methodologies, data bases, conceptual approaches and codes for modeling radionuclide transport through fractured host rocks. Specific objectives included: identification of the relevant transport processes, to test the extrapolation of laboratory sorption data to field conditions, and to demonstrate the applicability of currently used methodology for conceptualizing or building realistic transport models. Field tests and transport modeling work are complemented by an extensive laboratory program. The field experimental activities focused predominantly on establishing appropriate conditions for identifying relevant transport mechanisms on the scale of a few meters, aiming at full recovery of injected tracers, simple geometry and long-term stability of induced dipole flow fields. A relatively simple homogeneous, dual-porosity advection/diffusion model was built with input from a state of the art petrographic characterisation of the water conducting feature. It was possible to calibrate the model from conservative tracer breakthrough curves. (J.S.). 21 refs., 14 figs., 4 tabs

  13. Mixture-Amount Design and Response Surface Modeling to Assess the Effects of Flavonoids and Phenolic Acids on Developmental Performance of Anastrepha ludens

    OpenAIRE

    Pascacio-Villafán, Carlos; Lapointe, Stephen; Williams, Trevor; Sivinski, John; Niedz, Randall; Aluja, Martín

    2014-01-01

    Host plant resistance to insect attack and expansion of insect pests to novel hosts may to be modulated by phenolic compounds in host plants. Many studies have evaluated the role of phenolics in host plant resistance and the effect of phenolics on herbivore performance, but few studies have tested the joint effect of several compounds. Here, we used mixture-amount experimental design and response surface modeling to study the effects of a variety of phenolic compounds on the development and s...

  14. Ecosystem Model Skill Assessment. Yes We Can!

    Science.gov (United States)

    Olsen, Erik; Fay, Gavin; Gaichas, Sarah; Gamble, Robert; Lucey, Sean; Link, Jason S

    2016-01-01

    Accelerated changes to global ecosystems call for holistic and integrated analyses of past, present and future states under various pressures to adequately understand current and projected future system states. Ecosystem models can inform management of human activities in a complex and changing environment, but are these models reliable? Ensuring that models are reliable for addressing management questions requires evaluating their skill in representing real-world processes and dynamics. Skill has been evaluated for just a limited set of some biophysical models. A range of skill assessment methods have been reviewed but skill assessment of full marine ecosystem models has not yet been attempted. We assessed the skill of the Northeast U.S. (NEUS) Atlantis marine ecosystem model by comparing 10-year model forecasts with observed data. Model forecast performance was compared to that obtained from a 40-year hindcast. Multiple metrics (average absolute error, root mean squared error, modeling efficiency, and Spearman rank correlation), and a suite of time-series (species biomass, fisheries landings, and ecosystem indicators) were used to adequately measure model skill. Overall, the NEUS model performed above average and thus better than expected for the key species that had been the focus of the model tuning. Model forecast skill was comparable to the hindcast skill, showing that model performance does not degenerate in a 10-year forecast mode, an important characteristic for an end-to-end ecosystem model to be useful for strategic management purposes. We identify best-practice approaches for end-to-end ecosystem model skill assessment that would improve both operational use of other ecosystem models and future model development. We show that it is possible to not only assess the skill of a complicated marine ecosystem model, but that it is necessary do so to instill confidence in model results and encourage their use for strategic management. Our methods are applicable

  15. A user's guide to the GoldSim/BLT-MS integrated software package:a low-level radioactive waste disposal performance assessment model.

    Energy Technology Data Exchange (ETDEWEB)

    Knowlton, Robert G.; Arnold, Bill Walter; Mattie, Patrick D.

    2007-03-01

    Sandia National Laboratories (Sandia), a U.S. Department of Energy National Laboratory, has over 30 years experience in the assessment of radioactive waste disposal and at the time of this publication is providing assistance internationally in a number of areas relevant to the safety assessment of radioactive waste disposal systems. In countries with small radioactive waste programs, international technology transfer program efforts are often hampered by small budgets, schedule constraints, and a lack of experienced personnel. In an effort to surmount these difficulties, Sandia has developed a system that utilizes a combination of commercially available software codes and existing legacy codes for probabilistic safety assessment modeling that facilitates the technology transfer and maximizes limited available funding. Numerous codes developed and endorsed by the United States Nuclear Regulatory Commission (NRC) and codes developed and maintained by United States Department of Energy are generally available to foreign countries after addressing import/export control and copyright requirements. From a programmatic view, it is easier to utilize existing codes than to develop new codes. From an economic perspective, it is not possible for most countries with small radioactive waste disposal programs to maintain complex software, which meets the rigors of both domestic regulatory requirements and international peer review. Therefore, revitalization of deterministic legacy codes, as well as an adaptation of contemporary deterministic codes, provides a credible and solid computational platform for constructing probabilistic safety assessment models. This document is a reference users guide for the GoldSim/BLT-MS integrated modeling software package developed as part of a cooperative technology transfer project between Sandia National Laboratories and the Institute of Nuclear Energy Research (INER) in Taiwan for the preliminary assessment of several candidate low

  16. A user's guide to the GoldSim/BLT-MS integrated software package:a low-level radioactive waste disposal performance assessment model

    International Nuclear Information System (INIS)

    Knowlton, Robert G.; Arnold, Bill Walter; Mattie, Patrick D.

    2007-01-01

    Sandia National Laboratories (Sandia), a U.S. Department of Energy National Laboratory, has over 30 years experience in the assessment of radioactive waste disposal and at the time of this publication is providing assistance internationally in a number of areas relevant to the safety assessment of radioactive waste disposal systems. In countries with small radioactive waste programs, international technology transfer program efforts are often hampered by small budgets, schedule constraints, and a lack of experienced personnel. In an effort to surmount these difficulties, Sandia has developed a system that utilizes a combination of commercially available software codes and existing legacy codes for probabilistic safety assessment modeling that facilitates the technology transfer and maximizes limited available funding. Numerous codes developed and endorsed by the United States Nuclear Regulatory Commission (NRC) and codes developed and maintained by United States Department of Energy are generally available to foreign countries after addressing import/export control and copyright requirements. From a programmatic view, it is easier to utilize existing codes than to develop new codes. From an economic perspective, it is not possible for most countries with small radioactive waste disposal programs to maintain complex software, which meets the rigors of both domestic regulatory requirements and international peer review. Therefore, revitalization of deterministic legacy codes, as well as an adaptation of contemporary deterministic codes, provides a credible and solid computational platform for constructing probabilistic safety assessment models. This document is a reference users guide for the GoldSim/BLT-MS integrated modeling software package developed as part of a cooperative technology transfer project between Sandia National Laboratories and the Institute of Nuclear Energy Research (INER) in Taiwan for the preliminary assessment of several candidate low

  17. Treatment of uncertainty in low-level waste performance assessment

    International Nuclear Information System (INIS)

    Kozak, M.W.; Olague, N.E.; Gallegos, D.P.; Rao, R.R.

    1991-01-01

    Uncertainties arise from a number of different sources in low-level waste performance assessment. In this paper the types of uncertainty are reviewed, and existing methods for quantifying and reducing each type of uncertainty are discussed. These approaches are examined in the context of the current low-level radioactive waste regulatory performance objectives, which are deterministic. The types of uncertainty discussed in this paper are model uncertainty, uncertainty about future conditions, and parameter uncertainty. The advantages and disadvantages of available methods for addressing uncertainty in low-level waste performance assessment are presented. 25 refs

  18. [Teaching performance assessment in Public Health employing three different strategies].

    Science.gov (United States)

    Martínez-González, Adrián; Moreno-Altamirano, Laura; Ponce-Rosas, Efrén Raúl; Martínez-Franco, Adrián Israel; Urrutia-Aguilar, María Esther

    2011-01-01

    The educational system depends upon the quality and performance of their faculty and should therefore be process of continuous improvement. To assess the teaching performance of the Public Health professors, at the Faculty of Medicine, UNAM through three strategies. Justification study. The evaluation was conducted under a mediational model through three strategies: students' opinion assessment, self-assessment and students' academic achievement. We applied descriptive statistics, Student t test, ANOVA and Pearson correlation. Twenty professors were evaluated from the Public Health department, representing 57% of all them who teach the subject. The professor's performance was highly valued self-assessment compared with assessment of student opinion, was confirmed by statistical analysis the difference was significant. The difference amongst the three evaluation strategies became more evident between self-assessment and the scores obtained by students in their academic achievement. The integration of these three strategies offers a more complete view of the teacher's performance quality. Academic achievement appears to be a more objective strategy for teaching performance assessment than students' opinion and self-assessment.

  19. Assessing performance and validating finite element simulations using probabilistic knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Dolin, Ronald M.; Rodriguez, E. A. (Edward A.)

    2002-01-01

    Two probabilistic approaches for assessing performance are presented. The first approach assesses probability of failure by simultaneously modeling all likely events. The probability each event causes failure along with the event's likelihood of occurrence contribute to the overall probability of failure. The second assessment method is based on stochastic sampling using an influence diagram. Latin-hypercube sampling is used to stochastically assess events. The overall probability of failure is taken as the maximum probability of failure of all the events. The Likelihood of Occurrence simulation suggests failure does not occur while the Stochastic Sampling approach predicts failure. The Likelihood of Occurrence results are used to validate finite element predictions.

  20. The relationship between competence and performance: implications for assessing practice performance.

    Science.gov (United States)

    Rethans, J-J; Norcini, J J; Barón-Maldonado, M; Blackmore, D; Jolly, B C; LaDuca, T; Lew, S; Page, G G; Southgate, L H

    2002-10-01

    This paper aims to describe current views of the relationship between competence and performance and to delineate some of the implications of the distinctions between the two areas for the purpose of assessing doctors in practice. During a 2-day closed session, the authors, using their wide experiences in this domain, defined the problem and the context, discussed the content and set up a new model. This was developed further by e-mail correspondence over a 6-month period. Competency-based assessments were defined as measures of what doctors do in testing situations, while performance-based assessments were defined as measures of what doctors do in practice. The distinction between competency-based and performance-based methods leads to a three-stage model for assessing doctors in practice. The first component of the model proposed is a screening test that would identify doctors at risk. Practitioners who 'pass' the screen would move on to a continuous quality improvement process aimed at raising the general level of performance. Practitioners deemed to be at risk would undergo a more detailed assessment process focused on rigorous testing, with poor performers targeted for remediation or removal from practice. We propose a new model, designated the Cambridge Model, which extends and refines Miller's pyramid. It inverts his pyramid, focuses exclusively on the top two tiers, and identifies performance as a product of competence, the influences of the individual (e.g. health, relationships), and the influences of the system (e.g. facilities, practice time). The model provides a basis for understanding and designing assessments of practice performance.

  1. Risk assessment models in the tourism sector

    Directory of Open Access Journals (Sweden)

    Simanavicius Arturas

    2015-05-01

    Full Text Available One of the most prominent contemporary success stories is tourism. This industry began to significantly increase only in 1960, and during the last 50 years, tourism revenues and number of outgoing people have increased by a number of times. Therefore, the tourism sector is highly attractive to new business initiation and development of its dynamic growth, new activities, new trends and technologies, new markets and rapid changes. Purpose of the article - to analyze the prevailing risks in the tourism sector and to identify the business risk assessment models. Scientists pay big attention to risk analysis. A series of risk analysis theoretical, methodological and practical studies are made, but for the tourism risk scientistseconomists do not pay attention in practice. Tourism risk assessment models, analyzed in the article, showed their adaptability to tourism industry. Performed tourism economic risk assessment models showed that in the tourism risk classification it is appropriate to use a procedural approach, which is related to the tourism product identification stages. It would be logical to link the identification of risks to the tourism services in stages, as in each stage prevails certain risk groups The aim of the article - to analyze the tourism risk assessment models and on the basis of analysis to develop further tourism risk assessment model. Article originality is associated with the prepared tourism risk assessment model that is versatile and can be used in different countries in assessing the risks of tourism.

  2. Assessing the performance of dispersionless and dispersion-accounting methods: helium interaction with cluster models of the TiO2(110) surface.

    Science.gov (United States)

    de Lara-Castells, María Pilar; Stoll, Hermann; Mitrushchenkov, Alexander O

    2014-08-21

    As a prototypical dispersion-dominated physisorption problem, we analyze here the performance of dispersionless and dispersion-accounting methodologies on the helium interaction with cluster models of the TiO2(110) surface. A special focus has been given to the dispersionless density functional dlDF and the dlDF+Das construction for the total interaction energy (K. Pernal, R. Podeswa, K. Patkowski, and K. Szalewicz, Phys. Rev. Lett. 2009, 109, 263201), where Das is an effective interatomic pairwise functional form for the dispersion. Likewise, the performance of symmetry-adapted perturbation theory (SAPT) method is evaluated, where the interacting monomers are described by density functional theory (DFT) with the dlDF, PBE, and PBE0 functionals. Our benchmarks include CCSD(T)-F12b calculations and comparative analysis on the nuclear bound states supported by the He-cluster potentials. Moreover, intra- and intermonomer correlation contributions to the physisorption interaction are analyzed through the method of increments (H. Stoll, J. Chem. Phys. 1992, 97, 8449) at the CCSD(T) level of theory. This method is further applied in conjunction with a partitioning of the Hartree-Fock interaction energy to estimate individual interaction energy components, comparing them with those obtained using the different SAPT(DFT) approaches. The cluster size evolution of dispersionless and dispersion-accounting energy components is then discussed, revealing the reduced role of the dispersionless interaction and intramonomer correlation when the extended nature of the surface is better accounted for. On the contrary, both post-Hartree-Fock and SAPT(DFT) results clearly demonstrate the high-transferability character of the effective pairwise dispersion interaction whatever the cluster model is. Our contribution also illustrates how the method of increments can be used as a valuable tool not only to achieve the accuracy of CCSD(T) calculations using large cluster models but also to

  3. Empirical generalization assessment of neural network models

    DEFF Research Database (Denmark)

    Larsen, Jan; Hansen, Lars Kai

    1995-01-01

    competing models. Since all models are trained on the same data, a key issue is to take this dependency into account. The optimal split of the data set of size N into a cross-validation set of size Nγ and a training set of size N(1-γ) is discussed. Asymptotically (large data sees), γopt→1......This paper addresses the assessment of generalization performance of neural network models by use of empirical techniques. We suggest to use the cross-validation scheme combined with a resampling technique to obtain an estimate of the generalization performance distribution of a specific model....... This enables the formulation of a bulk of new generalization performance measures. Numerical results demonstrate the viability of the approach compared to the standard technique of using algebraic estimates like the FPE. Moreover, we consider the problem of comparing the generalization performance of different...

  4. White paper updating conclusions of 1998 ILAW performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    MANN, F.M.

    2000-05-11

    The purpose of this document is to provide a comparison of the estimated immobilized low-activity waste (LAW) disposal system performance against established performance objectives using the beat estimates for parameters and models to describe the system. The principal advances in knowledge since the last performance assessment (known as the 1998 ILAW PA [Mann 1998a]) have been in site specific information and data on the waste form performance for BNFL, Inc. relevant glass formulations. The white paper also estimates the maximum release rates for technetium and other key radionuclides and chemicals from the waste form. Finally, this white paper provides limited information on the impact of changes in waste form loading.

  5. White paper updating conclusions of 1998 ILAW performance assessment

    International Nuclear Information System (INIS)

    MANN, F.M.

    2000-01-01

    The purpose of this document is to provide a comparison of the estimated immobilized low-activity waste (LAW) disposal system performance against established performance objectives using the beat estimates for parameters and models to describe the system. The principal advances in knowledge since the last performance assessment (known as the 1998 ILAW PA [Mann 1998a]) have been in site specific information and data on the waste form performance for BNFL, Inc. relevant glass formulations. The white paper also estimates the maximum release rates for technetium and other key radionuclides and chemicals from the waste form. Finally, this white paper provides limited information on the impact of changes in waste form loading

  6. Energy performance assessment in urban planning competitions

    International Nuclear Information System (INIS)

    Eicker, Ursula; Monien, Dirk; Duminil, Éric; Nouvel, Romain

    2015-01-01

    Highlights: • Quantification of energy efficiency in urban planning. • Analysis based on 3D (city) model. • Impact evaluation of urban form on energy demand, supply and building costs. • Primary energy balance with and without inclusion of shadowing effects. - Abstract: Many cities today are committed to increase the energy efficiency of buildings and the fraction of renewables especially in new urban developments. However, quantitative data on building energy performance as a function of urban density, building compactness and orientation, building use and supply options are rarely available during the design of new cities or early scenario analysis for existing city quarters, making it difficult for cities to effectively evaluate which concepts work today and in the future. The paper proposes a methodology to assess the energy demand and supply options as a function of the availability of geometry, building standard and use data. An automated procedure was implemented to identify each building’s geometry and volume and transfer the information to a simulation tool, which then calculates heating demand and solar energy generation on roofs and facades. The simulation includes shading calculations for each segment of the façades and roofs and thus allows a very detailed quantification of the building energy demand. By applying the methodology to a case study city quarter designed in an urban competition in Munich, it could be shown how the urban design influences the energy demand of the quarter and which fractions of renewable energy can be integrated into the roofs. While the building insulation standard and use are the is most important criteria for building energy efficiency (with an impact of more than a factor 2), the exact geometrical form, compactness and urban shading effects influences the energy demand by 10–20%. On the other hand, the detailed roof geometry and orientation influences the possible solar coverage of electricity or thermal

  7. Guidance for performing preliminary assessments under CERCLA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-09-01

    EPA headquarters and a national site assessment workgroup produced this guidance for Regional, State, and contractor staff who manage or perform preliminary assessments (PAs). EPA has focused this guidance on the types of sites and site conditions most commonly encountered. The PA approach described in this guidance is generally applicable to a wide variety of sites. However, because of the variability among sites, the amount of information available, and the level of investigative effort required, it is not possible to provide guidance that is equally applicable to all sites. PA investigators should recognize this and be aware that variation from this guidance may be necessary for some sites, particularly for PAs performed at Federal facilities, PAs conducted under EPA`s Environmental Priorities Initiative (EPI), and PAs at sites that have previously been extensively investigated by EPA or others. The purpose of this guidance is to provide instructions for conducting a PA and reporting results. This guidance discusses the information required to evaluate a site and how to obtain it, how to score a site, and reporting requirements. This document also provides guidelines and instruction on PA evaluation, scoring, and the use of standard PA scoresheets. The overall goal of this guidance is to assist PA investigators in conducting high-quality assessments that result in correct site screening or further action recommendations on a nationally consistent basis.

  8. Statistical analysis in MSW collection performance assessment.

    Science.gov (United States)

    Teixeira, Carlos Afonso; Avelino, Catarina; Ferreira, Fátima; Bentes, Isabel

    2014-09-01

    The increase of Municipal Solid Waste (MSW) generated over the last years forces waste managers pursuing more effective collection schemes, technically viable, environmentally effective and economically sustainable. The assessment of MSW services using performance indicators plays a crucial role for improving service quality. In this work, we focus on the relevance of regular system monitoring as a service assessment tool. In particular, we select and test a core-set of MSW collection performance indicators (effective collection distance, effective collection time and effective fuel consumption) that highlights collection system strengths and weaknesses and supports pro-active management decision-making and strategic planning. A statistical analysis was conducted with data collected in mixed collection system of Oporto Municipality, Portugal, during one year, a week per month. This analysis provides collection circuits' operational assessment and supports effective short-term municipality collection strategies at the level of, e.g., collection frequency and timetables, and type of containers. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Maintenance personnel performance simulation (MAPPS): a model for predicting maintenance performance reliability in nuclear power plants

    International Nuclear Information System (INIS)

    Knee, H.E.; Krois, P.A.; Haas, P.M.; Siegel, A.I.; Ryan, T.G.

    1983-01-01

    The NRC has developed a structured, quantitative, predictive methodology in the form of a computerized simulation model for assessing maintainer task performance. Objective of the overall program is to develop, validate, and disseminate a practical, useful, and acceptable methodology for the quantitative assessment of NPP maintenance personnel reliability. The program was organized into four phases: (1) scoping study, (2) model development, (3) model evaluation, and (4) model dissemination. The program is currently nearing completion of Phase 2 - Model Development

  10. Performance model for a CCTV-MTI

    International Nuclear Information System (INIS)

    Dunn, D.R.; Dunbar, D.L.

    1978-01-01

    CCTV-MTI (closed circuit television--moving target indicator) monitors represent typical components of access control systems, as for example in a material control and accounting (MC and A) safeguards system. This report describes a performance model for a CCTV-MTI monitor. The performance of a human in an MTI role is a separate problem and is not addressed here. This work was done in conjunction with the NRC sponsored LLL assessment procedure for MC and A systems which is presently under development. We develop a noise model for a generic camera system and a model for the detection mechanism for a postulated MTI design. These models are then translated into an overall performance model. Measures of performance are probabilities of detection and false alarm as a function of intruder-induced grey level changes in the protected area. Sensor responsivity, lens F-number, source illumination and spectral response were treated as design parameters. Some specific results are illustrated for a postulated design employing a camera with a Si-target vidicon. Reflectance or light level changes in excess of 10% due to an intruder will be detected with a very high probability for the portion of the visible spectrum with wavelengths above 500 nm. The resulting false alarm rate was less than one per year. We did not address sources of nuisance alarms due to adverse environments, reliability, resistance to tampering, nor did we examine the effects of the spatial frequency response of the optics. All of these are important and will influence overall system detection performance

  11. Modelling and evaluation of surgical performance using hidden Markov models.

    Science.gov (United States)

    Megali, Giuseppe; Sinigaglia, Stefano; Tonet, Oliver; Dario, Paolo

    2006-10-01

    Minimally invasive surgery has become very widespread in the last ten years. Since surgeons experience difficulties in learning and mastering minimally invasive techniques, the development of training methods is of great importance. While the introduction of virtual reality-based simulators has introduced a new paradigm in surgical training, skill evaluation methods are far from being objective. This paper proposes a method for defining a model of surgical expertise and an objective metric to evaluate performance in laparoscopic surgery. Our approach is based on the processing of kinematic data describing movements of surgical instruments. We use hidden Markov model theory to define an expert model that describes expert surgical gesture. The model is trained on kinematic data related to exercises performed on a surgical simulator by experienced surgeons. Subsequently, we use this expert model as a reference model in the definition of an objective metric to evaluate performance of surgeons with different abilities. Preliminary results show that, using different topologies for the expert model, the method can be efficiently used both for the discrimination between experienced and novice surgeons, and for the quantitative assessment of surgical ability.

  12. Environmental performance assessment: a case study in the paper industry

    Directory of Open Access Journals (Sweden)

    Paula Antonov

    2011-09-01

    Full Text Available The inherent complexity of environmental performance measurement makes it difficult to be gauged, sending it forth to methodologies supported on assessments of the various factors that could influence the overall performance. In association with the environmental performance lies the need to create methods that allows the assessment over the time in order to facilitate comparisons amongst different organizations or operations of a same company. Measurement of environmental performance comes from several sources thus a dominant approach widely recognized and accepted by the academic community and organizations can not be singled out. The purpose of this review is to test a method for assessing environmental performance in a manufacturer organization, performing a case study in the paper industry. The results can be compared with other operations and can be used, cumulatively, in supply chains. The specific objectives are (i to model the environmental performance of the transaction, (ii to use the model to measure performance, and (iii to interpret the results and come to a conclusion. It begins with a review of the environmental performance measurement and then proceeds to the description of the research methodology and the results of its application. The method consists of five constructs, assessed by managers and processes experts according to their potential of environmental performance's improvement: solid waste, wastewater, gas emissions, deployment of natural resources, and legal compliance. The constructs are perceived by qualitative indicators categorically evaluated. The final result is an index of 76.69%, which represents the environmental performance of the operation.

  13. Modeling of Communication in a Computational Situation Assessment Model

    International Nuclear Information System (INIS)

    Lee, Hyun Chul; Seong, Poong Hyun

    2009-01-01

    Operators in nuclear power plants have to acquire information from human system interfaces (HSIs) and the environment in order to create, update, and confirm their understanding of a plant state, or situation awareness, because failures of situation assessment may result in wrong decisions for process control and finally errors of commission in nuclear power plants. Quantitative or prescriptive models to predict operator's situation assessment in a situation, the results of situation assessment, provide many benefits such as HSI design solutions, human performance data, and human reliability. Unfortunately, a few computational situation assessment models for NPP operators have been proposed and those insufficiently embed human cognitive characteristics. Thus we proposed a new computational situation assessment model of nuclear power plant operators. The proposed model incorporating significant cognitive factors uses a Bayesian belief network (BBN) as model architecture. It is believed that communication between nuclear power plant operators affects operators' situation assessment and its result, situation awareness. We tried to verify that the proposed model represent the effects of communication on situation assessment. As the result, the proposed model succeeded in representing the operators' behavior and this paper shows the details

  14. Beef Species Symposium: an assessment of the 1996 Beef NRC: metabolizable protein supply and demand and effectiveness of model performance prediction of beef females within extensive grazing systems.

    Science.gov (United States)

    Waterman, R C; Caton, J S; Löest, C A; Petersen, M K; Roberts, A J

    2014-07-01

    Interannual variation of forage quantity and quality driven by precipitation events influence beef livestock production systems within the Southern and Northern Plains and Pacific West, which combined represent 60% (approximately 17.5 million) of the total beef cows in the United States. The beef cattle requirements published by the NRC are an important tool and excellent resource for both professionals and producers to use when implementing feeding practices and nutritional programs within the various production systems. The objectives of this paper include evaluation of the 1996 Beef NRC model in terms of effectiveness in predicting extensive range beef cow performance within arid and semiarid environments using available data sets, identifying model inefficiencies that could be refined to improve the precision of predicting protein supply and demand for range beef cows, and last, providing recommendations for future areas of research. An important addition to the current Beef NRC model would be to allow users to provide region-specific forage characteristics and the ability to describe supplement composition, amount, and delivery frequency. Beef NRC models would then need to be modified to account for the N recycling that occurs throughout a supplementation interval and the impact that this would have on microbial efficiency and microbial protein supply. The Beef NRC should also consider the role of ruminal and postruminal supply and demand of specific limiting AA. Additional considerations should include the partitioning effects of nitrogenous compounds under different physiological production stages (e.g., lactation, pregnancy, and periods of BW loss). The intent of information provided is to aid revision of the Beef NRC by providing supporting material for changes and identifying gaps in existing scientific literature where future research is needed to enhance the predictive precision and application of the Beef NRC models.

  15. Scientific performance assessments through a gender lens

    DEFF Research Database (Denmark)

    Nielsen, Mathias Wullum

    2018-01-01

    The focus on excellence and quality assurance in the academy has spawned a signifi cant increase in the use of bibliometric measures in performance assessments of individual researchers. This article investigates the organizational consequences of this development through a gender lens. Based....... They adhere to the prevailing ethos of the academic meritocracy by standardizing the criteria for organizational advancement and ensuring transparency and accountability in the selection process. While bibliometric tools in this sense may lead to the recruitment of scientists with a strong CV and track record...

  16. The Assessment Cycle: A Model for Learning through Peer Assessment

    Science.gov (United States)

    Reinholz, Daniel

    2016-01-01

    This paper advances a model describing how peer assessment supports self-assessment. Although prior research demonstrates that peer assessment promotes self-assessment, the connection between these two activities is underspecified. This model, the assessment cycle, draws from theories of self-assessment to elaborate how learning takes place…

  17. Model uncertainty in safety assessment

    International Nuclear Information System (INIS)

    Pulkkinen, U.; Huovinen, T.

    1996-01-01

    The uncertainty analyses are an essential part of any risk assessment. Usually the uncertainties of reliability model parameter values are described by probability distributions and the uncertainty is propagated through the whole risk model. In addition to the parameter uncertainties, the assumptions behind the risk models may be based on insufficient experimental observations and the models themselves may not be exact descriptions of the phenomena under analysis. The description and quantification of this type of uncertainty, model uncertainty, is the topic of this report. The model uncertainty is characterized and some approaches to model and quantify it are discussed. The emphasis is on so called mixture models, which have been applied in PSAs. Some of the possible disadvantages of the mixture model are addressed. In addition to quantitative analyses, also qualitative analysis is discussed shortly. To illustrate the models, two simple case studies on failure intensity and human error modeling are described. In both examples, the analysis is based on simple mixture models, which are observed to apply in PSA analyses. (orig.) (36 refs., 6 figs., 2 tabs.)

  18. Environmental performance assessment of a company of aluminum surface treatment

    Directory of Open Access Journals (Sweden)

    Susan Catieri Ramalho

    2013-08-01

    Full Text Available The purpose of this article was to evaluate the environmental performance of a medium-sized company that provides services for surface treatment of aluminum. The treatment is known as anodizing. The research method was qualitative numerical modeling. The environmental performance of the company was organized into five constructs: atmosphere, wastewater, energy and natural resources, solid waste, and legislation and management. Nineteen indicators were chosen to explain the five constructs. Ten employees of the company prioritized the constructs and evaluated the situation of the indicators by means of a scale of assessment. By means of a mathematical model, the general performance of the environmental operation was calculated at 74.5% of the maximum possible. The indicators that most contributed to the performance not to reach 100% were consumption of electricity and water consumption. The construct of worse performance was natural and energy resources. These are the priorities for future environmental improvement actions that the company may promote.

  19. Performance assessment task team progress report

    International Nuclear Information System (INIS)

    Wood, D.E.; Curl, R.U.; Armstrong, D.R.; Cook, J.R.; Dolenc, M.R.; Kocher, D.C.; Owens, K.W.; Regnier, E.P.; Roles, G.W.; Seitz, R.R.

    1994-05-01

    The U.S. Department of Energy (DOE) Headquarters EM-35, established a Performance Assessment Task Team (referred to as the Team) to integrate the activities of the sites that are preparing performance assessments (PAs) for disposal of new low-level waste, as required by Chapter III of DOE Order 5820.2A, open-quotes Low-Level Waste Managementclose quotes. The intent of the Team is to achieve a degree of consistency among these PAs as the analyses proceed at the disposal sites. The Team's purpose is to recommend policy and guidance to the DOE on issues that impact the PAs, including release scenarios and parameters, so that the approaches are as consistent as possible across the DOE complex. The Team has identified issues requiring attention and developed discussion papers for those issues. Some issues have been completed, and the recommendations are provided in this document. Other issues are still being discussed, and the status summaries are provided in this document. A major initiative was to establish a subteam to develop a set of test scenarios and parameters for benchmarking codes in use at the various sites. The activities of the Team are reported here through December 1993

  20. Calibration of PMIS pavement performance prediction models.

    Science.gov (United States)

    2012-02-01

    Improve the accuracy of TxDOTs existing pavement performance prediction models through calibrating these models using actual field data obtained from the Pavement Management Information System (PMIS). : Ensure logical performance superiority patte...

  1. Mixture-amount design and response surface modeling to assess the effects of flavonoids and phenolic acids on developmental performance of Anastrepha ludens.

    Science.gov (United States)

    Pascacio-Villafán, Carlos; Lapointe, Stephen; Williams, Trevor; Sivinski, John; Niedz, Randall; Aluja, Martín

    2014-03-01

    Host plant resistance to insect attack and expansion of insect pests to novel hosts may to be modulated by phenolic compounds in host plants. Many studies have evaluated the role of phenolics in host plant resistance and the effect of phenolics on herbivore performance, but few studies have tested the joint effect of several compounds. Here, we used mixture-amount experimental design and response surface modeling to study the effects of a variety of phenolic compounds on the development and survival of Mexican fruit fly (Anastrepha ludens [Loew]), a notorious polyphagous pest of fruit crops that is likely to expand its distribution range under climate change scenarios. (+)- Catechin, phloridzin, rutin, chlorogenic acid, and p-coumaric acid were added individually or in mixtures at different concentrations to a laboratory diet used to rear individuals of A. ludens. No effect was observed with any mixture or concentration on percent pupation, pupal weight, adult emergence, or survival from neonate larvae to adults. Larval weight, larval and pupal developmental time, and the prevalence of adult deformities were affected by particular mixtures and concentrations of the compounds tested. We suggest that some combinations/concentrations of phenolic compounds could contribute to the management of A. ludens. We also highlight the importance of testing mixtures of plant secondary compounds when exploring their effects upon insect herbivore performance, and we show that mixture-amount design is a useful tool for this type of experiments.

  2. SKI SITE-94. Deep Repository Performance Assessment Project. Summary

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    The function of SITE-94 is to provide the Swedish Nuclear Power Inspectorate (SKI) with the capacity and supporting knowledge needed for reviewing the Swedish nuclear industry`s R and D programs and for reviewing license applications, as stipulated in Swedish legislation. The report is structured as a Performance Assessment exercise needed for input to decisions regarding repository safety, but the SITE-94 is neither a safety assessment nor a model for future assessments to be undertaken by the prospective licensee. The specific project objectives of SITE-94 comprise site evaluation, performance assessment methodology, canister integrity and radionuclide release and transport calculations. The main report (SKI-R--96-36) gives a detailed description of the many inter-related studies undertaken as part of the research project, while the present report presents a condensed summary of the main report. 46 refs.

  3. Performance Objective for Tank Farm Closure Risk Assessments

    International Nuclear Information System (INIS)

    MANN, F.M.; KNEPP, A.J.; BADDEN, J.

    2003-01-01

    To be meaningful, results from a numeric risk assessment of the consequences of an action must be compared against the standards for such an action. That is, before one disposes of waste or closes a facility with waste, one must show that the disposal or closure action protects the public health and safety and the environment. These standards are called performance objectives. Regulations requiring performing performance assessments, (whether federal ones like the Department of Energy [DOE] Order 435.1, Radioactive Waste Management and its implementing guides or Washington State ones like the regulations implementing the Washington Administrative Code [WAC] 173-340 ''Model Toxics Control Act - Cleanup''), usually require that the determination of performance objectives be one of the first steps performed. These performance objectives not only set comparison level for the numeric results, but also define the media, pathways, exposure scenarios (receptors), spatial locations, and times that the performance assessment must consider. Thus, a performance objective consists of a compliance level, place(s) of compliance, and time(s) of compliance. Performance objectives are not the levels that a regulatory agency will enforce in a permit or authorization. Those levels, often called enforcement levels, will be set in the permit or authorization. Rather, performance objectives are those levels against which the results of the numeric simulation will be compared to judge the success of the proposed cleanup or disposal actions. Additional comparison levels may be requested for information purposes, but are not officially part of the decision on the adequacy of the proposed action. To emphasize that the performance objectives discussed in this document are not regulatory performance objectives, the three components of the performance objective will be renamed in this document as assessment standard, point(s) of assessment, and time(s) of assessment. However, whenever

  4. Model description and evaluation of model performance: DOSDIM model

    International Nuclear Information System (INIS)

    Lewyckyj, N.; Zeevaert, T.

    1996-01-01

    DOSDIM was developed to assess the impact to man from routine and accidental atmospheric releases. It is a compartmental, deterministic, radiological model. For an accidental release, dynamic transfer are used in opposition to a routine release for which equilibrium transfer factors are used. Parameters values were chosen to be conservative. Transfer between compartments are described by first-order differential equations. 2 figs

  5. Performance assessment development for a LILW repository in Slovenia

    International Nuclear Information System (INIS)

    Zeleznik, N.; Mele, I.

    2001-01-01

    Simultaneously with the site selection process for a low and intermediate level radioactive waste (LILW) repository, the preliminary assessment of the influence of the specific disposal concept on the environment and on the population was developed. The performance assessment team, organized in 1997 by ARAO, prepared several basic studies in order to clarify the objectives of the performance and safety assessment (PA/SA) procedure. In 1999 also the first performance assessment of two safety cases (surface and underground) for generic site for a LILW repository was realized. In the year 2000 activities on PA/SA analyses continued. A systematic, generic list was prepared of all possible features, events and processes (FEP list) predictable for surface or underground LILW disposal in Slovenia. Recommended and selected were the most reliable scenarios with conceptual models for LILW disposal in normal and altered evolution conditions. New verification of the obtained results was done with more powerful and accurate models for the surface repository over an aquifer of lower water permeability and an underground repository in a plastic rock. The results for both generic cases under normal evolution scenarios showed that there is a negligible dose influence on members of the critical population due to the migration of radionuclides from the foreseen LILW repository. The results of the already performed work as well as plans for the future activities are presented in the paper.(author)

  6. Performing Probabilistic Risk Assessment Through RAVEN

    Energy Technology Data Exchange (ETDEWEB)

    A. Alfonsi; C. Rabiti; D. Mandelli; J. Cogliati; R. Kinoshita

    2013-06-01

    The Reactor Analysis and Virtual control ENviroment (RAVEN) code is a software tool that acts as the control logic driver and post-processing engine for the newly developed Thermal-Hydraulic code RELAP-7. RAVEN is now a multi-purpose Probabilistic Risk Assessment (PRA) software framework that allows dispatching different functionalities: Derive and actuate the control logic required to simulate the plant control system and operator actions (guided procedures), allowing on-line monitoring/controlling in the Phase Space Perform both Monte-Carlo sampling of random distributed events and Dynamic Event Tree based analysis Facilitate the input/output handling through a Graphical User Interface (GUI) and a post-processing data mining module

  7. Contribution to a quantitative assessment model for reliability-based metrics of electronic and programmable safety-related functions; Contribution a un modele d'evaluation quantitative des performances fiabilistes de fonctions electroniques et programmables dediees a la securite

    Energy Technology Data Exchange (ETDEWEB)

    Hamidi, K

    2005-10-15

    The use of fault-tolerant EP architectures has induced growing constraints, whose influence on reliability-based performance metrics is no more negligible. To face up the growing influence of simultaneous failure, this thesis proposes, for safety-related functions, a new-trend assessment method of reliability, based on a better taking into account of time-aspect. This report introduces the concept of information and uses it to interpret the failure modes of safety-related function as the direct result of the initiation and propagation of erroneous information until the actuator-level. The main idea is to distinguish the apparition and disappearance of erroneous states, which could be defined as intrinsically dependent of HW-characteristic and maintenance policies, and their possible activation, constrained through architectural choices, leading to the failure of safety-related function. This approach is based on a low level on deterministic SED models of the architecture and use non homogeneous Markov chains to depict the time-evolution of probabilities of errors. (author)

  8. Assessing organizational performance in intensive care units: a French experience.

    Science.gov (United States)

    Minvielle, Etienne; Aegerter, Philippe; Dervaux, Benoît; Boumendil, Ariane; Retbi, Aurélia; Jars-Guincestre, Marie Claude; Guidet, Bertrand

    2008-06-01

    The objective of the study was to assess and to explain variation of organizational performance in intensive care units (ICUs). This was a prospective multicenter study. The study involved 26 ICUs located in the Paris area, France, participating in a regional database. Data were collected through answers of 1000 ICU personnel to the Culture, Organization, and Management in Intensive Care questionnaire and from the database. Organizational performance was assessed through a composite score related to 5 dimensions: coordination and adaptation to uncertainty, communication, conflict management, organizational change, and organizational learning, Skills developed in relationship with patients and their families. Statistical comparisons between ICUs were performed by analysis of variance with a Scheffé pairwise procedure. A multilevel regression model was used to analyze both individual and structural variables explaining differences of ICU's organizational performance. The organizational performance score differed among ICUs. Some cultural values were negatively correlated with a high level of organizational performance, suggesting improvement potential. Several individual and structural factors were also related to the quality of ICU organization, including absence of burnout, older staff, satisfaction to work, and high workload (P managers to assess the organizational performance of their ICU based on a validated questionnaire. Differences are mainly explained by cultural values and individual well-being factors, introducing new requirements for managing human resources in ICUs.

  9. Assessing the performance of gas collection systems in select Chinese landfills according to the LandGEM model: drawbacks and potential direction.

    Science.gov (United States)

    Sun, Yue; Yue, Dongbei; Li, Rundong; Yang, Ting; Liu, Shiliang

    2015-01-01

    In China, municipal solid waste (MSW) is primarily treated by landfilling. Landfill gas (LFG) collection effectively reduces methane emission from MSW landfills. An accurate system of LFG collection is important in landfill planning, design, and operation. However, China has not developed such systems. In this study, the efficiency of methane collection is calculated in three Chinese landfills with different collection systems (A: vertical wells for MSW before 2010; combined horizontal trenches and under-membrane pipes for MSW from 2011 onwards; B: combined horizontal trenches and vertical wells; C: vertical wells only). This efficiency was computed by dividing the quantity of methane obtained from landfill operation records by the quantity estimated based on the LandGEM model. Results show that the collection efficiencies of landfills with vertical wells and/or horizontal pipes ranged from 8.3% to 27.9%, whereas those of a system equipped with geomembrane reached 65.3%. The poor performance of the landfills was attributed to the open burning of early-stage LFG, LFG release from cracks in high-density polyethylene covers, and high levels of leachate within a landfill site. Therefore, this study proposes an integrated LFG collection system that can remove leachate and collect gas from landfills that accept waste with high moisture content.

  10. Modelling the predictive performance of credit scoring

    Directory of Open Access Journals (Sweden)

    Shi-Wei Shen

    2013-07-01

    Research purpose: The purpose of this empirical paper was to examine the predictive performance of credit scoring systems in Taiwan. Motivation for the study: Corporate lending remains a major business line for financial institutions. However, in light of the recent global financial crises, it has become extremely important for financial institutions to implement rigorous means of assessing clients seeking access to credit facilities. Research design, approach and method: Using a data sample of 10 349 observations drawn between 1992 and 2010, logistic regression models were utilised to examine the predictive performance of credit scoring systems. Main findings: A test of Goodness of fit demonstrated that credit scoring models that incorporated the Taiwan Corporate Credit Risk Index (TCRI, micro- and also macroeconomic variables possessed greater predictive power. This suggests that macroeconomic variables do have explanatory power for default credit risk. Practical/managerial implications: The originality in the study was that three models were developed to predict corporate firms’ defaults based on different microeconomic and macroeconomic factors such as the TCRI, asset growth rates, stock index and gross domestic product. Contribution/value-add: The study utilises different goodness of fits and receiver operator characteristics during the examination of the robustness of the predictive power of these factors.

  11. Human Performance Models of Pilot Behavior

    Science.gov (United States)

    Foyle, David C.; Hooey, Becky L.; Byrne, Michael D.; Deutsch, Stephen; Lebiere, Christian; Leiden, Ken; Wickens, Christopher D.; Corker, Kevin M.

    2005-01-01

    Five modeling teams from industry and academia were chosen by the NASA Aviation Safety and Security Program to develop human performance models (HPM) of pilots performing taxi operations and runway instrument approaches with and without advanced displays. One representative from each team will serve as a panelist to discuss their team s model architecture, augmentations and advancements to HPMs, and aviation-safety related lessons learned. Panelists will discuss how modeling results are influenced by a model s architecture and structure, the role of the external environment, specific modeling advances and future directions and challenges for human performance modeling in aviation.

  12. Post-closure performance assessment treatment of the biosphere

    International Nuclear Information System (INIS)

    Broderick, M.A.; Egan, M.J.; Thorne, M.C.; Williams, J.A.

    1996-01-01

    The Nirex strategy for radioactive waste disposal is based on a system of engineered and natural barriers, providing long-term isolation of the waste from those parts of the environment that are in contact with or readily available for use by humans (i.e. the biosphere). Even so, there remains the possibility that, on a timescale of thousands to tens of thousands of years, small quantities of poorly-sorbed, long-lived radionuclides may be released from the engineered disposal system, ultimately to emerge into the biosphere. Biosphere models are used in post-closure performance assessments to quantify the competing effects of dilution and accumulation processes on radionuclide concentrations in the accessible environment. Understanding biosphere processes and their time dependence is necessary not only to determine the radiological impact of possible future releases, but also to characterise the dynamics of transport in groundwater and the location, duration and extent of any such releases. Nirex is developing a new biosphere model for use in post-closure radiological assessments for the proposed Sellafield repository. A compartment modelling approach has been adopted, as in studies performed previously, but the system will be dynamic, allowing changes with time in both the properties of compartments and the transfers between compartments. The transport model considers both mass transport within the biosphere and the migration of radionuclides, thereby ensuring that a self-consistent description of the biosphere, in a spatially-extensive domain is maintained. The above approach is designed to link the assessment models used by the Nirex assessment team more closely into the Nirex biosphere research programme than has hitherto been possible with time-invariant assessment models. (author)

  13. Modelling fuel cell performance using artificial intelligence

    Energy Technology Data Exchange (ETDEWEB)

    Ogaji, S.O.T.; Singh, R.; Pilidis, P.; Diacakis, M. [Power Propulsion and Aerospace Engineering Department, Centre for Diagnostics and Life Cycle Costs, Cranfield University (United Kingdom)

    2006-03-09

    Over the last few years, fuel cell technology has been increasing promisingly its share in the generation of stationary power. Numerous pilot projects are operating worldwide, continuously increasing the amount of operating hours either as stand-alone devices or as part of gas turbine combined cycles. An essential tool for the adequate and dynamic analysis of such systems is a software model that enables the user to assess a large number of alternative options in the least possible time. On the other hand, the sphere of application of artificial neural networks has widened covering such endeavours of life such as medicine, finance and unsurprisingly engineering (diagnostics of faults in machines). Artificial neural networks have been described as diagrammatic representation of a mathematical equation that receives values (inputs) and gives out results (outputs). Artificial neural networks systems have the capacity to recognise and associate patterns and because of their inherent design features, they can be applied to linear and non-linear problem domains. In this paper, the performance of the fuel cell is modelled using artificial neural networks. The inputs to the network are variables that are critical to the performance of the fuel cell while the outputs are the result of changes in any one or all of the fuel cell design variables, on its performance. Critical parameters for the cell include the geometrical configuration as well as the operating conditions. For the neural network, various network design parameters such as the network size, training algorithm, activation functions and their causes on the effectiveness of the performance modelling are discussed. Results from the analysis as well as the limitations of the approach are presented and discussed. (author)

  14. Modelling fuel cell performance using artificial intelligence

    Science.gov (United States)

    Ogaji, S. O. T.; Singh, R.; Pilidis, P.; Diacakis, M.

    Over the last few years, fuel cell technology has been increasing promisingly its share in the generation of stationary power. Numerous pilot projects are operating worldwide, continuously increasing the amount of operating hours either as stand-alone devices or as part of gas turbine combined cycles. An essential tool for the adequate and dynamic analysis of such systems is a software model that enables the user to assess a large number of alternative options in the least possible time. On the other hand, the sphere of application of artificial neural networks has widened covering such endeavours of life such as medicine, finance and unsurprisingly engineering (diagnostics of faults in machines). Artificial neural networks have been described as diagrammatic representation of a mathematical equation that receives values (inputs) and gives out results (outputs). Artificial neural networks systems have the capacity to recognise and associate patterns and because of their inherent design features, they can be applied to linear and non-linear problem domains. In this paper, the performance of the fuel cell is modelled using artificial neural networks. The inputs to the network are variables that are critical to the performance of the fuel cell while the outputs are the result of changes in any one or all of the fuel cell design variables, on its performance. Critical parameters for the cell include the geometrical configuration as well as the operating conditions. For the neural network, various network design parameters such as the network size, training algorithm, activation functions and their causes on the effectiveness of the performance modelling are discussed. Results from the analysis as well as the limitations of the approach are presented and discussed.

  15. Climate Modeling Computing Needs Assessment

    Science.gov (United States)

    Petraska, K. E.; McCabe, J. D.

    2011-12-01

    This paper discusses early findings of an assessment of computing needs for NASA science, engineering and flight communities. The purpose of this assessment is to document a comprehensive set of computing needs that will allow us to better evaluate whether our computing assets are adequately structured to meet evolving demand. The early results are interesting, already pointing out improvements we can make today to get more out of the computing capacity we have, as well as potential game changing innovations for the future in how we apply information technology to science computing. Our objective is to learn how to leverage our resources in the best way possible to do more science for less money. Our approach in this assessment is threefold: Development of use case studies for science workflows; Creating a taxonomy and structure for describing science computing requirements; and characterizing agency computing, analysis, and visualization resources. As projects evolve, science data sets increase in a number of ways: in size, scope, timelines, complexity, and fidelity. Generating, processing, moving, and analyzing these data sets places distinct and discernable requirements on underlying computing, analysis, storage, and visualization systems. The initial focus group for this assessment is the Earth Science modeling community within NASA's Science Mission Directorate (SMD). As the assessment evolves, this focus will expand to other science communities across the agency. We will discuss our use cases, our framework for requirements and our characterizations, as well as our interview process, what we learned and how we plan to improve our materials after using them in the first round of interviews in the Earth Science Modeling community. We will describe our plans for how to expand this assessment, first into the Earth Science data analysis and remote sensing communities, and then throughout the full community of science, engineering and flight at NASA.

  16. Total System Performance Assessment - License Application Methods and Approach

    International Nuclear Information System (INIS)

    McNeish, J.

    2003-01-01

    ''Total System Performance Assessment-License Application (TSPA-LA) Methods and Approach'' provides the top-level method and approach for conducting the TSPA-LA model development and analyses. The method and approach is responsive to the criteria set forth in Total System Performance Assessment Integration (TSPAI) Key Technical Issues (KTIs) identified in agreements with the U.S. Nuclear Regulatory Commission, the ''Yucca Mountain Review Plan'' (YMRP), ''Final Report'' (NRC 2003 [163274]), and the NRC final rule 10 CFR Part 63 (NRC 2002 [156605]). This introductory section provides an overview of the TSPA-LA, the projected TSPA-LA documentation structure, and the goals of the document. It also provides a brief discussion of the regulatory framework, the approach to risk management of the development and analysis of the model, and the overall organization of the document. The section closes with some important conventions that are used in this document

  17. Total System Performance Assessment-License Application Methods and Approach

    Energy Technology Data Exchange (ETDEWEB)

    J. McNeish

    2002-09-13

    ''Total System Performance Assessment-License Application (TSPA-LA) Methods and Approach'' provides the top-level method and approach for conducting the TSPA-LA model development and analyses. The method and approach is responsive to the criteria set forth in Total System Performance Assessment Integration (TSPAI) Key Technical Issue (KTI) agreements, the ''Yucca Mountain Review Plan'' (CNWRA 2002 [158449]), and 10 CFR Part 63. This introductory section provides an overview of the TSPA-LA, the projected TSPA-LA documentation structure, and the goals of the document. It also provides a brief discussion of the regulatory framework, the approach to risk management of the development and analysis of the model, and the overall organization of the document. The section closes with some important conventions that are utilized in this document.

  18. A Performance Assessment of NASA's Heliophysics Program

    Science.gov (United States)

    2009-01-01

    Recognizing the importance of distributed observations of all elements of the Sun-to-Earth system and the synergies between observation and theory and between basic and targeted research, the National Research Council's 2003 solar and space physics decadal survey laid out an integrated research strategy that sought to extend and augment what has now become the Heliophysics Great Observatory as well as to enhance NASA, NOAA, NSF, and DOD's other solar and space physics research activities. The Integrated Research Strategy provided a prioritized list of flight missions and theory and modeling programs that would advance the relevant physical theories, incorporate those theories in models that describe a system of interactions between the Sun and the space environment, obtain data on the system, and analyze and test the adequacy of the theories and models. As directed by Congress in the NASA Authorization Act of 2005, the purpose of this report is to assess the progress of NASA's Heliophysics Division at the 5-year mark against the NASA goals and priorities laid out in the decadal survey. In addition to the Integrated Research Strategy, the decadal survey also considered non-mission-specific initiatives to foster a robust solar and space physics program. The decadal survey set forth driving science challenges as well as recommendations devoted to the need for technology development, collaborations and cooperation with other disciplines, understanding the effects of the space environment on technology and society, education and public outreach, and steps that could strengthen and enhance the research enterprise. Unfortunately, very little of the recommended NASA program priorities from the decadal survey s Integrated Research Strategy will be realized during the period (2004-2013) covered by the survey. Mission cost growth, reordering of survey mission priorities, and unrealized budget assumptions have delayed or deferred nearly all of the NASA spacecraft missions

  19. SUPPLY CHAIN ANALYSIS AND PERFORMANCE ASSESSMENT OF SME FISHERIES CLUSTERS

    Directory of Open Access Journals (Sweden)

    Anton Agus Setyawan

    2017-12-01

    Full Text Available Study of SME in Indonesia related with business networks and performance in these business organizations. In many cases, regional administration in Indonesia develops SME business network in the form of clusters. This study analyzes SME fisheries clusters with supply chain analysis.  We also develop performance assessment of SME fisheries cluster by using multivariate model. This study involves 62 SMEs in Sragen, Central Java Indonesia. Those SMEs  includes in fisheries cluster in the area. Our findings show that SME fisheries cluster has in-efficient supply chain. This business clusters has problems in profit setting and delivery time which harm their performance. We measure business performance by using business selling, profit rate and asset growth. We found that cost structure, man power and physical production has positive effects to business performance.

  20. E-Area Performance Assessment Interim Measures Assessment FY2005

    International Nuclear Information System (INIS)

    Stallings, M

    2006-01-01

    After major changes to the limits for various disposal units of the E-Area Low Level Waste Facility (ELLWF) last year, no major changes have been made during FY2005. A Special Analysis was completed which removes the air pathway 14 C limit from the Intermediate Level Vault (ILV). This analysis will allow the disposal of reactor moderator deionizers which previously had no pathway to disposal. Several studies have also been completed providing groundwater transport input for future special analyses. During the past year, since Slit Trenches No.1 and No.2 were nearing volumetric capacity, they were operationally closed under a preliminary closure analysis. This analysis was performed using as-disposed conditions and data and showed that concrete rubble from the demolition of 232-F was acceptable for disposal in the STs even though the latest special analysis for the STs had reduced the tritium limits so that the inventory in the rubble exceeded limits. A number of special studies are planned during the next years; perhaps the largest of these will be revision of the Performance Assessment (PA) for the ELLWF. The revision will be accomplished by incorporating special analyses performed since the last PA revision as well as revising analyses to include new data. Projected impacts on disposal limits of more recent studies have been estimated. No interim measures will be applied during this year. However, it is being recommended that tritium disposals to the Components-in-Grout (CIG) Trenches be suspended until a limited Special Analysis (SA) currently in progress is completed. This SA will give recommendations for optimum placement of tritiated D-Area tower waste. Further recommendations for tritiated waste placement in the CIG Trenches will be given in the upcoming PA revision

  1. E-Area Performance Assessment Interim Measures Assessment FY2005

    Energy Technology Data Exchange (ETDEWEB)

    Stallings, M

    2006-01-31

    After major changes to the limits for various disposal units of the E-Area Low Level Waste Facility (ELLWF) last year, no major changes have been made during FY2005. A Special Analysis was completed which removes the air pathway {sup 14}C limit from the Intermediate Level Vault (ILV). This analysis will allow the disposal of reactor moderator deionizers which previously had no pathway to disposal. Several studies have also been completed providing groundwater transport input for future special analyses. During the past year, since Slit Trenches No.1 and No.2 were nearing volumetric capacity, they were operationally closed under a preliminary closure analysis. This analysis was performed using as-disposed conditions and data and showed that concrete rubble from the demolition of 232-F was acceptable for disposal in the STs even though the latest special analysis for the STs had reduced the tritium limits so that the inventory in the rubble exceeded limits. A number of special studies are planned during the next years; perhaps the largest of these will be revision of the Performance Assessment (PA) for the ELLWF. The revision will be accomplished by incorporating special analyses performed since the last PA revision as well as revising analyses to include new data. Projected impacts on disposal limits of more recent studies have been estimated. No interim measures will be applied during this year. However, it is being recommended that tritium disposals to the Components-in-Grout (CIG) Trenches be suspended until a limited Special Analysis (SA) currently in progress is completed. This SA will give recommendations for optimum placement of tritiated D-Area tower waste. Further recommendations for tritiated waste placement in the CIG Trenches will be given in the upcoming PA revision.

  2. Modelling and Motivating Academic Performance.

    Science.gov (United States)

    Brennan, Geoffrey; Pettit, Philip

    1991-01-01

    Three possible motivators for college teachers (individual economic interest, academic virtue, and academic honor) suggest mechanisms that can be used to improve performance. Policies need to address all three motivators; economic levers alone may undermine alternative ways of supporting good work. (MSE)

  3. Branch technical position for performance assessment of low-level radioactive waste disposal facilities

    International Nuclear Information System (INIS)

    Campbell, A.C.; Abramson, L.; Byrne, R.M.

    1994-01-01

    The U.S. Nuclear Regulatory Commission has developed a Draft Branch Technical Position on Performance Assessment of Low-Level Radioactive Waste Disposal Facilities. The draft technical position addresses important issues in performance assessment modeling and provides a framework and technical basis for conducting and evaluating performance assessments in a disposal facility license application. The technical position also addresses specific technical policy issues and augments existing NRC guidance pertaining to LLW performance assessment

  4. Cognitive performance modeling based on general systems performance theory.

    Science.gov (United States)

    Kondraske, George V

    2010-01-01

    General Systems Performance Theory (GSPT) was initially motivated by problems associated with quantifying different aspects of human performance. It has proved to be invaluable for measurement development and understanding quantitative relationships between human subsystem capacities and performance in complex tasks. It is now desired to bring focus to the application of GSPT to modeling of cognitive system performance. Previous studies involving two complex tasks (i.e., driving and performing laparoscopic surgery) and incorporating measures that are clearly related to cognitive performance (information processing speed and short-term memory capacity) were revisited. A GSPT-derived method of task analysis and performance prediction termed Nonlinear Causal Resource Analysis (NCRA) was employed to determine the demand on basic cognitive performance resources required to support different levels of complex task performance. This approach is presented as a means to determine a cognitive workload profile and the subsequent computation of a single number measure of cognitive workload (CW). Computation of CW may be a viable alternative to measuring it. Various possible "more basic" performance resources that contribute to cognitive system performance are discussed. It is concluded from this preliminary exploration that a GSPT-based approach can contribute to defining cognitive performance models that are useful for both individual subjects and specific groups (e.g., military pilots).

  5. A performance assessment methodology for low-level waste facilities

    International Nuclear Information System (INIS)

    Kozak, M.W.; Chu, M.S.Y.; Mattingly, P.A.

    1990-07-01

    A performance assessment methodology has been developed for use by the US Nuclear Regulatory Commission in evaluating license applications for low-level waste disposal facilities. This report provides a summary of background reports on the development of the methodology and an overview of the models and codes selected for the methodology. The overview includes discussions of the philosophy and structure of the methodology and a sequential procedure for applying the methodology. Discussions are provided of models and associated assumptions that are appropriate for each phase of the methodology, the goals of each phase, data required to implement the models, significant sources of uncertainty associated with each phase, and the computer codes used to implement the appropriate models. In addition, a sample demonstration of the methodology is presented for a simple conceptual model. 64 refs., 12 figs., 15 tabs

  6. Performance of joint modelling of time-to-event data with time-dependent predictors: an assessment based on transition to psychosis data

    Directory of Open Access Journals (Sweden)

    Hok Pan Yuen

    2016-10-01

    Full Text Available Joint modelling has emerged to be a potential tool to analyse data with a time-to-event outcome and longitudinal measurements collected over a series of time points. Joint modelling involves the simultaneous modelling of the two components, namely the time-to-event component and the longitudinal component. The main challenges of joint modelling are the mathematical and computational complexity. Recent advances in joint modelling have seen the emergence of several software packages which have implemented some of the computational requirements to run joint models. These packages have opened the door for more routine use of joint modelling. Through simulations and real data based on transition to psychosis research, we compared joint model analysis of time-to-event outcome with the conventional Cox regression analysis. We also compared a number of packages for fitting joint models. Our results suggest that joint modelling do have advantages over conventional analysis despite its potential complexity. Our results also suggest that the results of analyses may depend on how the methodology is implemented.

  7. An evaluation of selected in silico models for the assessment of skin sensitization potential – performance and practical utility considerations (QSAR conference)

    Science.gov (United States)

    Skin sensitization remains an important endpoint for consumers, manufacturers and regulators. Although the development of alternative approaches to assess skin sensitization potential has been extremely active over many years, the implication of regulations such as REACH and the ...

  8. Assembly line performance and modeling

    Science.gov (United States)

    Rane, Arun B.; Sunnapwar, Vivek K.

    2017-09-01

    Automobile sector forms the backbone of manufacturing sector. Vehicle assembly line is important section in automobile plant where repetitive tasks are performed one after another at different workstations. In this thesis, a methodology is proposed to reduce cycle time and time loss due to important factors like equipment failure, shortage of inventory, absenteeism, set-up, material handling, rejection and fatigue to improve output within given cost constraints. Various relationships between these factors, corresponding cost and output are established by scientific approach. This methodology is validated in three different vehicle assembly plants. Proposed methodology may help practitioners to optimize the assembly line using lean techniques.

  9. Generalization performance of regularized neural network models

    DEFF Research Database (Denmark)

    Larsen, Jan; Hansen, Lars Kai

    1994-01-01

    Architecture optimization is a fundamental problem of neural network modeling. The optimal architecture is defined as the one which minimizes the generalization error. This paper addresses estimation of the generalization performance of regularized, complete neural network models. Regularization...

  10. Sensitivity assessment of fuel performance codes for LOCA accident scenario

    International Nuclear Information System (INIS)

    Abe, Alfredo; Gomes, Daniel; Silva, Antonio Teixeira e; Muniz, Rafael O.R.; Giovedi, Claudia; Martins, Marcelo

    2017-01-01

    FRAPCON code predicts fuel rod performance in LWR (Light Water Reactor) by modeling fuel responses under normal operating conditions and anticipated operational occurrences; FRAPTRAN code is applied for fuel transient under fast transient and accident conditions. The codes are well known and applied for different purposes and one of the use is to address sensitivity analysis considering fuel design parameters associated to fabrication, moreover can address the effect of physical models bias. The objective of this work was to perform an assessment of fuel manufacturing parameters tolerances and fuel models bias using FRAPCON and FRAPTRAN codes for Loss of Coolant Accident (LOCA) scenario. The preliminary analysis considered direct approach taken into account most relevant manufacturing tolerances (lower and upper bounds) related to design parameters and physical models bias without considering their statistical distribution. The simulations were carried out using the data available in the open literature related to the series of LOCA experiment performed at the Halden reactor (specifically IFA-650.5). The manufacturing tolerances associated to design parameters considered in this paper were: enrichment, cladding thickness, pellet diameter, pellet density, and filling gas pressure. The physical models considered were: fuel thermal expansion, fission gas release, fuel swelling, irradiation creep, cladding thermal expansion, cladding corrosion, and cladding hydrogen pickup. The results obtained from sensitivity analysis addressed the impact of manufacturing tolerances and physical models in the fuel cladding burst time observed for the IFA-650.5 experiment. (author)

  11. Sensitivity assessment of fuel performance codes for LOCA accident scenario

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Alfredo; Gomes, Daniel; Silva, Antonio Teixeira e; Muniz, Rafael O.R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Giovedi, Claudia; Martins, Marcelo, E-mail: ayabe@ipen.br, E-mail: claudia.giovedi@labrisco.usp.br [Universidade de Sao Paulo (LABRISCO/USP), Sao Paulo, SP (Brazil). Lab. de Análise, Avaliação e Gerenciamento de Risco

    2017-07-01

    FRAPCON code predicts fuel rod performance in LWR (Light Water Reactor) by modeling fuel responses under normal operating conditions and anticipated operational occurrences; FRAPTRAN code is applied for fuel transient under fast transient and accident conditions. The codes are well known and applied for different purposes and one of the use is to address sensitivity analysis considering fuel design parameters associated to fabrication, moreover can address the effect of physical models bias. The objective of this work was to perform an assessment of fuel manufacturing parameters tolerances and fuel models bias using FRAPCON and FRAPTRAN codes for Loss of Coolant Accident (LOCA) scenario. The preliminary analysis considered direct approach taken into account most relevant manufacturing tolerances (lower and upper bounds) related to design parameters and physical models bias without considering their statistical distribution. The simulations were carried out using the data available in the open literature related to the series of LOCA experiment performed at the Halden reactor (specifically IFA-650.5). The manufacturing tolerances associated to design parameters considered in this paper were: enrichment, cladding thickness, pellet diameter, pellet density, and filling gas pressure. The physical models considered were: fuel thermal expansion, fission gas release, fuel swelling, irradiation creep, cladding thermal expansion, cladding corrosion, and cladding hydrogen pickup. The results obtained from sensitivity analysis addressed the impact of manufacturing tolerances and physical models in the fuel cladding burst time observed for the IFA-650.5 experiment. (author)

  12. Human performance assessment: methods and measures

    International Nuclear Information System (INIS)

    Andresen, Gisle; Droeivoldsmo, Asgeir

    2000-10-01

    The Human Error Analysis Project (HEAP) was initiated in 1994. The aim of the project was to acquire insights on how and why cognitive errors occur when operators are engaged in problem solving in advanced integrated control rooms. Since human error had not been studied in the HAlden Man-Machine LABoratory (HAMMLAB) before, it was also necessary to carry out research in methodology. In retrospect, it is clear that much of the methodological work is relevant to human-machine research in general, and not only to research on human error. The purpose of this report is, therefore, to give practitioners and researchers an overview of the methodological parts of HEAP. The scope of the report is limited to methods used throughout the data acquisition process, i.e., data-collection methods, data-refinement methods, and measurement methods. The data-collection methods include various types of verbal protocols, simulator logs, questionnaires, and interviews. Data-refinement methods involve different applications of the Eyecon system, a flexible data-refinement tool, and small computer programs used for rearranging, reformatting, and aggregating raw-data. Measurement methods involve assessment of diagnostic behaviour, erroneous actions, complexity, task/system performance, situation awareness, and workload. The report concludes that the data-collection methods are generally both reliable and efficient. The data-refinement methods, however, should be easier to use in order to facilitate explorative analyses. Although the series of experiments provided an opportunity for measurement validation, there are still uncertainties connected to several measures, due to their reliability still being unknown. (Author). 58 refs.,7 tabs

  13. Uncertainty analysis for low-level radioactive waste disposal performance assessment at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D.W.; Yambert, M.W.; Kocher, D.C.

    1994-12-31

    A performance assessment of the operating Solid Waste Storage Area 6 (SWSA 6) facility for the disposal of low-level radioactive waste at the Oak Ridge National Laboratory has been prepared to provide the technical basis for demonstrating compliance with the performance objectives of DOE Order 5820.2A, Chapter 111.2 An analysis of the uncertainty incorporated into the assessment was performed which addressed the quantitative uncertainty in the data used by the models, the subjective uncertainty associated with the models used for assessing performance of the disposal facility and site, and the uncertainty in the models used for estimating dose and human exposure. The results of the uncertainty analysis were used to interpret results and to formulate conclusions about the performance assessment. This paper discusses the approach taken in analyzing the uncertainty in the performance assessment and the role of uncertainty in performance assessment.

  14. Framework of integrated performance assessment in Kristallin-I

    International Nuclear Information System (INIS)

    Smith, P.A.

    1994-01-01

    Kristallin-I is an integrated analysis carried out by Nagra to investigate the option of disposal of vitrified high level waste in the crystalline basement of Northern Switzerland, which takes account of the findings in the Phase 1 geological investigation of this host rocks. Kristallin-I updates and complements Project Gewahr 1985 with extended data bases, improved calculational tools and models. Performance assessment aims at quantitatively assessing the long term, post-closure performance of the repository system in the expected geological environment, analyzing the sensitivity of prediction of parameter variation and identifying the key processes contributing to safety, assessing the relative importance of engineered and natural barriers, and identifying the requirement on site-specific geology. The Nagra concept of the disposal is described. In order to evaluate the radiological consequence of the repository, scenario uncertainty, conceptual model uncertainty and data uncertainty must be taken into account. The assessment method is explained. The reference scenario, the time history of annual individual dose, the effect on the radiological impact of varying groundwater flow rate and alternative scenarios are reported. The current repository design and the geological interpretation of the potential host rocks are shown to provide the condition for safe repositories. (K.I.)

  15. Performance Assessment Links in Science (PALS). ERIC/AE Digest.

    Science.gov (United States)

    Quellmalz, Edys; Schank, Patricia; Hinojosa, Thomas; Padilla, Christine

    To meet the need for innovative approaches for sharing exemplary assessment resources, to facilitate new assessments, and to increase understanding of how the use of standards-based performance assessment can advance educational reform, SRI International is developing Performance Assessment Links in Science (PALS), an on-line, standards-based,…

  16. Performance Assessment for the Workplace. Volume I.

    Science.gov (United States)

    Wigdor, Alexandra K., Ed.; Green, Bert F., Jr., Ed.

    This is the sixth and final report of the National Research Council's Committee on the Performance of Military Personnel on the Joint-Service Job Performance Measurement/Enlistment Standards (JPM) Project, a project designed to develop measures of performance for entry-level military jobs so that enlistment standards could be linked to performance…

  17. Problematizing the concept of the "borderline" group in performance assessments.

    Science.gov (United States)

    Homer, Matt; Pell, Godfrey; Fuller, Richard

    2017-05-01

    Many standard setting procedures focus on the performance of the "borderline" group, defined through expert judgments by assessors. In performance assessments such as Objective Structured Clinical Examinations (OSCEs), these judgments usually apply at the station level. Using largely descriptive approaches, we analyze the assessment profile of OSCE candidates at the end of a five year undergraduate medical degree program to investigate the consistency of the borderline group across stations. We look specifically at those candidates who are borderline in individual stations, and in the overall assessment. While the borderline group can be clearly defined at the individual station level, our key finding is that the membership of this group varies considerably across stations. These findings pose challenges for some standard setting methods, particularly the borderline group and objective borderline methods. They also suggest that institutions should ensure appropriate conjunctive rules to limit compensation in performance between stations to maximize "diagnostic accuracy". In addition, this work highlights a key benefit of sequential testing formats in OSCEs. In comparison with a traditional, single-test format, sequential models allow assessment of "borderline" candidates across a wider range of content areas with concomitant improvements in pass/fail decision-making.

  18. Performance assessment of the proposed Monitored Retrievable Storage Facility

    Energy Technology Data Exchange (ETDEWEB)

    Chockie, A.D.; Hostick, C.J.; Winter, C.

    1986-02-01

    Pacific Northwest laboratory (PNL) has completed a performance evaluation of the proposed monitored retrievable storage (MRS) facility. This study was undertaken as part of the Department of Energy MRS Program at PNL. The objective of the performance evaluation was to determine whether the conceptual MRS facility would be able to process spent fuel at the specified design rate of 3600 metric tons of uranium (MTU) per year. The performance of the proposed facility was assessed using the computer model COMPACT (Computer Optimization of Processing and Cask Transport) to simulate facility operations. The COMPACT model consisted of three application models each of which addressed a different aspect of the facility's operation: MRS/waste transportation interface; cask handling capability; and disassembly/consolidation (hot cell) operations. Our conclusions, based on the assessment of design criteria for the proposed facility, are as follows: Facilities and equipment throughout the facility have capability beyond the 3600 MTU/y design requirement. This added capability provides a reserve to compensate for unexpected perturbations in shipping or handling of the spent fuel. Calculations indicate that the facility's maximum maintainable processing capability is approximately 4800 MTU/y.

  19. Performance assessment of the proposed Monitored Retrievable Storage Facility

    International Nuclear Information System (INIS)

    Chockie, A.D.; Hostick, C.J.; Winter, C.

    1986-02-01

    Pacific Northwest laboratory (PNL) has completed a performance evaluation of the proposed monitored retrievable storage (MRS) facility. This study was undertaken as part of the Department of Energy MRS Program at PNL. The objective of the performance evaluation was to determine whether the conceptual MRS facility would be able to process spent fuel at the specified design rate of 3600 metric tons of uranium (MTU) per year. The performance of the proposed facility was assessed using the computer model COMPACT (Computer Optimization of Processing and Cask Transport) to simulate facility operations. The COMPACT model consisted of three application models each of which addressed a different aspect of the facility's operation: MRS/waste transportation interface; cask handling capability; and disassembly/consolidation (hot cell) operations. Our conclusions, based on the assessment of design criteria for the proposed facility, are as follows: Facilities and equipment throughout the facility have capability beyond the 3600 MTU/y design requirement. This added capability provides a reserve to compensate for unexpected perturbations in shipping or handling of the spent fuel. Calculations indicate that the facility's maximum maintainable processing capability is approximately 4800 MTU/y

  20. Model description and evaluation of model performance, scenario S. Multiple pathways assessment of the IAEA/CEC co-ordinated research programme on validation of environmental model predictions (VAMP)

    Energy Technology Data Exchange (ETDEWEB)

    Suolanen, V. [VTT Energy, Espoo (Finland). Nuclear Energy

    1996-12-01

    A modelling approach was used to predict doses from a large area deposition of {sup 137}Cs over southern and central Finland. The assumed deposition profile and quantity were both similar to those resulting from the Chernobyl accident. In the study, doses via terrestrial and aquatic environments have been analyzed. Additionally, the intermediate results of the study, such as concentrations in various foodstuffs and the resulting body burdents, were presented. The contributions of ingestion, inhalation and external doses to the total dose were estimated in the study. The considered deposition scenario formed a modelling exercise in the IAEA coordinated research programme on Validation of Environmental Model Predictions, the VAMP project. (21 refs.).

  1. Model description and evaluation of model performance, scenario S. Multiple pathways assessment of the IAEA/CEC co-ordinated research programme on validation of environmental model predictions (VAMP)

    International Nuclear Information System (INIS)

    Suolanen, V.

    1996-12-01

    A modelling approach was used to predict doses from a large area deposition of 137 Cs over southern and central Finland. The assumed deposition profile and quantity were both similar to those resulting from the Chernobyl accident. In the study, doses via terrestrial and aquatic environments have been analyzed. Additionally, the intermediate results of the study, such as concentrations in various foodstuffs and the resulting body burdents, were presented. The contributions of ingestion, inhalation and external doses to the total dose were estimated in the study. The considered deposition scenario formed a modelling exercise in the IAEA coordinated research programme on Validation of Environmental Model Predictions, the VAMP project. (21 refs.)

  2. Special Forces Interpersonal Performance Assessment System

    National Research Council Canada - National Science Library

    Carpenter, Tara D; Wisecarver, Michelle M; Deagle, Edwin A., III; Mendini, Kip G

    2005-01-01

    ... developmental training activities that could improve these skills. This report describes the development of a model that can serve as a foundation to develop these skills. An evaluation of the model and the application of the model to develop a training program are discussed.

  3. Assessment model validity document FARF31

    International Nuclear Information System (INIS)

    Elert, Mark; Gylling Bjoern; Lindgren, Maria

    2004-08-01

    The prime goal of model validation is to build confidence in the model concept and that the model is fit for its intended purpose. In other words: Does the model predict transport in fractured rock adequately to be used in repository performance assessments. Are the results reasonable for the type of modelling tasks the model is designed for. Commonly, in performance assessments a large number of realisations of flow and transport is made to cover the associated uncertainties. Thus, the flow and transport including radioactive chain decay are preferably calculated in the same model framework. A rather sophisticated concept is necessary to be able to model flow and radionuclide transport in the near field and far field of a deep repository, also including radioactive chain decay. In order to avoid excessively long computational times there is a need for well-based simplifications. For this reason, the far field code FARF31 is made relatively simple, and calculates transport by using averaged entities to represent the most important processes. FARF31 has been shown to be suitable for the performance assessments within the SKB studies, e.g. SR 97. Among the advantages are that it is a fast, simple and robust code, which enables handling of many realisations with wide spread in parameters in combination with chain decay of radionuclides. Being a component in the model chain PROPER, it is easy to assign statistical distributions to the input parameters. Due to the formulation of the advection-dispersion equation in FARF31 it is possible to perform the groundwater flow calculations separately.The basis for the modelling is a stream tube, i.e. a volume of rock including fractures with flowing water, with the walls of the imaginary stream tube defined by streamlines. The transport within the stream tube is described using a dual porosity continuum approach, where it is assumed that rock can be divided into two distinct domains with different types of porosity

  4. Assessment model validity document FARF31

    Energy Technology Data Exchange (ETDEWEB)

    Elert, Mark; Gylling Bjoern; Lindgren, Maria [Kemakta Konsult AB, Stockholm (Sweden)

    2004-08-01

    The prime goal of model validation is to build confidence in the model concept and that the model is fit for its intended purpose. In other words: Does the model predict transport in fractured rock adequately to be used in repository performance assessments. Are the results reasonable for the type of modelling tasks the model is designed for. Commonly, in performance assessments a large number of realisations of flow and transport is made to cover the associated uncertainties. Thus, the flow and transport including radioactive chain decay are preferably calculated in the same model framework. A rather sophisticated concept is necessary to be able to model flow and radionuclide transport in the near field and far field of a deep repository, also including radioactive chain decay. In order to avoid excessively long computational times there is a need for well-based simplifications. For this reason, the far field code FARF31 is made relatively simple, and calculates transport by using averaged entities to represent the most important processes. FARF31 has been shown to be suitable for the performance assessments within the SKB studies, e.g. SR 97. Among the advantages are that it is a fast, simple and robust code, which enables handling of many realisations with wide spread in parameters in combination with chain decay of radionuclides. Being a component in the model chain PROPER, it is easy to assign statistical distributions to the input parameters. Due to the formulation of the advection-dispersion equation in FARF31 it is possible to perform the groundwater flow calculations separately.The basis for the modelling is a stream tube, i.e. a volume of rock including fractures with flowing water, with the walls of the imaginary stream tube defined by streamlines. The transport within the stream tube is described using a dual porosity continuum approach, where it is assumed that rock can be divided into two distinct domains with different types of porosity

  5. Constrained bayesian inference of project performance models

    OpenAIRE

    Sunmola, Funlade

    2013-01-01

    Project performance models play an important role in the management of project success. When used for monitoring projects, they can offer predictive ability such as indications of possible delivery problems. Approaches for monitoring project performance relies on available project information including restrictions imposed on the project, particularly the constraints of cost, quality, scope and time. We study in this paper a Bayesian inference methodology for project performance modelling in ...

  6. ORGANIZATIONAL LEARNING AND PERFORMANCE. A CONCEPTUAL MODEL

    OpenAIRE

    Alexandra Luciana GUÞÃ

    2013-01-01

    Throught this paper, our main objective is to propose a conceptual model that links the notions of organizational learning (as capability and as a process) and organizational performance. Our contribution consists in analyzing the literature on organizational learning and organizational performance and in proposing an integrated model, that comprises: organizational learning capability, the process of organizational learning, organizational performance, human capital (the value and uniqueness...

  7. Empirical Assessment on Financial Regulations and Banking Sector Performance

    Directory of Open Access Journals (Sweden)

    Igbinosa S.

    2017-09-01

    Full Text Available This study examines financial regulation and banking sector performance in Nigeria. Specifically, the study determines the impact of reforms on banking sector performance and also assesses the nexus between capital adequacy and banking sector performance. Time series data for the period 1993 to 2014 was used. As an analytical tool, the study uses unit root test to determine the stationary state of the variables. We also employed the Johansson co-integration and error correction model (ECM statistical techniques to establish both short-run and long-run dynamic relationships between the endogenous and exogenous variables. The empirical findings indicate that financial regulation significantly impacts the banking sector performance while financial regulation has both short-run and long-run dynamic relationships with the banking sector performance in Nigeria. It was found that the four-period lag of capital adequacy negatively affects banking sector performance and is not statistically significant. The paper suggests that the Central Bank of Nigeria (CBN should continually make public the impacts that the various financial regulations and reforms have on the performance of Nigerian banks. Majority of the policies on financial regulation by the apex bank (CBN need to be long-run which can enable confidence of stakeholders, shareholders and the general public in the Nigerian banking industry when critically evaluated.

  8. Assessing a Theoretical Model on EFL College Students

    Science.gov (United States)

    Chang, Yu-Ping

    2011-01-01

    This study aimed to (1) integrate relevant language learning models and theories, (2) construct a theoretical model of college students' English learning performance, and (3) assess the model fit between empirically observed data and the theoretical model proposed by the researchers of this study. Subjects of this study were 1,129 Taiwanese EFL…

  9. PERFORMANCE ASSESSMENT AND GEOMETRIC CALIBRATION OF RESOURCESAT-2

    Directory of Open Access Journals (Sweden)

    P. V. Radhadevi

    2016-06-01

    Full Text Available Resourcesat-2 (RS-2 has successfully completed five years of operations in its orbit. This satellite has multi-resolution and multi-spectral capabilities in a single platform. A continuous and autonomous co-registration, geo-location and radiometric calibration of image data from different sensors with widely varying view angles and resolution was one of the challenges of RS-2 data processing. On-orbit geometric performance of RS-2 sensors has been widely assessed and calibrated during the initial phase operations. Since then, as an ongoing activity, various geometric performance data are being generated periodically. This is performed with sites of dense ground control points (GCPs. These parameters are correlated to the direct geo-location accuracy of the RS-2 sensors and are monitored and validated to maintain the performance. This paper brings out the geometric accuracy assessment, calibration and validation done for about 500 datasets of RS-2. The objectives of this study are to ensure the best absolute and relative location accuracy of different cameras, location performance with payload steering and co-registration of multiple bands. This is done using a viewing geometry model, given ephemeris and attitude data, precise camera geometry and datum transformation. In the model, the forward and reverse transformations between the coordinate systems associated with the focal plane, payload, body, orbit and ground are rigorously and explicitly defined. System level tests using comparisons to ground check points have validated the operational geo-location accuracy performance and the stability of the calibration parameters.

  10. Performance assessment of simple and modified cycle turboshaft gas turbines

    Directory of Open Access Journals (Sweden)

    Barinyima Nkoi

    2013-06-01

    Full Text Available This paper focuses on investigations encompassing comparative assessment of gas turbine cycle options. More specifically, investigation was carried out of technical performance of turboshaft engine cycles based on existing simple cycle (SC and its projected modified cycles for civil helicopter application. Technically, thermal efficiency, specific fuel consumption, and power output are of paramount importance to the overall performance of gas turbine engines. In course of carrying out this research, turbomatch software established at Cranfield University based on gas turbine theory was applied to conduct simulation of a simple cycle (baseline two-spool helicopter turboshaft engine model with free power turbine. Similarly, some modified gas turbine cycle configurations incorporating unconventional components, such as engine cycle with low pressure compressor (LPC zero-staged, recuperated engine cycle, and intercooled/recuperated (ICR engine cycle, were also simulated. In doing so, design point (DP and off-design point (OD performances of the engine models were established. The percentage changes in performance parameters of the modified cycle engines over the simple cycle were evaluated and it was found that to a large extent, the modified engine cycles with unconventional components exhibit better performances in terms of thermal efficiency and specific fuel consumption than the traditional simple cycle engine. This research made use of public domain open source references.

  11. Structure, conduct and performance paradigm in assessing travel agency performances

    Directory of Open Access Journals (Sweden)

    Stănciulescu Gabriela Cecilia

    2017-07-01

    Full Text Available The purpose of this paper is to present and exemplify traditional and neoclassical approaches to market structure and tourism firm performance analysis. The paper tackles some of the industrial economic thinking trends which were meant to fill the gaps left by the traditional approaches. Two approaches stand out from among the industrial economic trends: SCP paradigm and game theory. The results show that the strategy tourism operators prefer is to practise high prices; however there is no certainty that the competitors would adhere to such an idea at the beginning or during the season.

  12. Total System Performance Assessment: Enhanced Design Alternative V

    International Nuclear Information System (INIS)

    N. Erb; S. Miller; V. Vallikat

    1999-01-01

    This calculation documents the total system performance assessment modeling of Enhanced Design Analysis (EDA) V. EDA V is based on the TSPA-VA base design which has been modified with higher thermal loading, a quartz sand invert, and line loading with 21 PWR waste packages that have 2-cm thick titanium grade 7 corrosion resistance material (CRM) drip shields placed over dual-layer waste packages composed of 'inside out' VA reference material (CRWMS M and O 1999a). This document details the changes and assumptions made to the VA reference Performance Assessment Model (CRWMS M and O 1998a) to incorporate the design changes detailed for EDA V. The performance measure for this evaluation is expected value dose-rate history. Time histories of dose rate are presented for EDA V and a Defense in Depth (DID) analysis base on EDA V. Additional details concerning the Enhanced Design Alternative II are provided in the 'LADS 3-12 Requests' interoffice correspondence (CRWMS M and O 1999a)

  13. A survey for assessing university performance

    Directory of Open Access Journals (Sweden)

    Hosseinali Bahramzadeh

    2012-09-01

    Full Text Available One of the popular methods to increase the performance of educational services such as public or private universities is to make performance measurement. The people who work for an organization are normally considered as the best people to judge about the performance of a workplace since they know most existing weakness points in their workplace. The proposed study of this paper looks into a university performance in three inside, process and outside's perspectives. We design and distribute a questionnaire among 69 university professors and 295 students. In this survey, we ask them how they evaluate university in terms of different criteria such as educational and research facilities, etc. The results of our survey indicate that the university is not in good condition in terms of research activities but it has maintained good condition in terms of other perspectives such as educational, infrastructure, etc.

  14. FACSIM/MRS-1: Cask receiving and consolidation performance assessment

    International Nuclear Information System (INIS)

    Lotz, T.L.; Shay, M.R.

    1987-06-01

    A simulation analysis was completed to assess the performance of the shipping cask receiving and spent-fuel handling, consolidation and canistering operations of the Monitored Retrievable Storage (MRS) facility. One purpose of this evaluation was to estimate the limits of MRS operational capabilities and factors leading to those limitations. The model used to obtain the performance assessment, FACSIM/MRS-1, is one of two components of the FACSIM model developed by PNL's simulation effort for the nuclear waste-handling facility. FACSIM/MRS-1 provides the user with information about lag-storage requirements, machine use, cask queues, welder queues, and cask process and cask turnaround times. The model can help determine the effect that the following activities have on operating efficiency: (1) receiving multiple cask shipments, when rail-cask or truck-cask shipments arrive at the facility in groups of two or more, and (2) operating the facility five days per week, three shifts per day or seven days per week, three shifts per day for any conditions. In addition, sensitivity to equipment failure frequency and the time needed for equipment repair can be studied. Information on the above operating characteristics may be obtained for any spent-fuel rate, any split of shipments between truck and rail transport, or any split of boiling water reactor/pressurized water reactor fuel

  15. PERFORMANCE ASSESSMENT ASSISTANCE ACTIVITIES IN THE DOE COMPLEX

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, R.

    2012-01-23

    The United States Department of Energy Office of Environmental Management (DOE-EM) has established a Performance Assessment Community of Practice (PA CoP) to foster the sharing of information among performance assessment (PA) and risk assessment practitioners, regulators and oversight personnel. The general intent is to contribute to continuous improvement in the consistency, technical adequacy and quality of implementation of PAs and risk assessments around the DOE Complex. The PA CoP activities have involved commercial disposal facilities and international participants to provide a global perspective. The PA CoP has also sponsored annual technical exchanges as a means to foster improved communication and to share lessons learned from on-going modelling activities. The PA CoP encourages activities to provide programmatic and technical assistance in the form of sharing experience and lessons learned with practitioners during the development of PAs and risk assessments. This assistance complements DOE-EM reviews through the Low-Level Waste Disposal Facility Federal Review Group (LFRG) that are conducted after modelling efforts are completed. Such up-front assistance is providing additional value in terms of improving consistency and sharing of information. There has been a substantial increase in the amount of assistance being provided. The assistance has been well received by practitioners and regulators that have been involved. The paper highlights assistance and sharing of information that has been conducted in the last two years to support activities underway in support of proposed disposal facilities at Paducah, Portsmouth, and the Idaho National Laboratory and tank closure at Hanford.

  16. Energy performance assessment of collective housing buildings

    OpenAIRE

    Fumagalli, Benjamin

    2013-01-01

    This project has been carried out for the ALEC (Agence Locale de l'Energie et du Climat) of Grenoble urban area, a French energy and climate agency. It has been composed of several missions, all related to energy management in residential buildings. First, an annual energy use assessment have been conducted for two different building samples:  the eco-district of De Bonne in Grenoble and a sample of about 25 social housing buildings over the region. These two assessments showed that the avera...

  17. Utility of Social Modeling for Proliferation Assessment - Preliminary Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Coles, Garill A.; Gastelum, Zoe N.; Brothers, Alan J.; Thompson, Sandra E.

    2009-06-01

    This Preliminary Assessment draft report will present the results of a literature search and preliminary assessment of the body of research, analysis methods, models and data deemed to be relevant to the Utility of Social Modeling for Proliferation Assessment research. This report will provide: 1) a description of the problem space and the kinds of information pertinent to the problem space, 2) a discussion of key relevant or representative literature, 3) a discussion of models and modeling approaches judged to be potentially useful to the research, and 4) the next steps of this research that will be pursued based on this preliminary assessment. This draft report represents a technical deliverable for the NA-22 Simulations, Algorithms, and Modeling (SAM) program. Specifically this draft report is the Task 1 deliverable for project PL09-UtilSocial-PD06, Utility of Social Modeling for Proliferation Assessment. This project investigates non-traditional use of social and cultural information to improve nuclear proliferation assessment, including nonproliferation assessment, proliferation resistance assessments, safeguards assessments and other related studies. These assessments often use and create technical information about the State’s posture towards proliferation, the vulnerability of a nuclear energy system to an undesired event, and the effectiveness of safeguards. This project will find and fuse social and technical information by explicitly considering the role of cultural, social and behavioral factors relevant to proliferation. The aim of this research is to describe and demonstrate if and how social science modeling has utility in proliferation assessment.

  18. Performance Assessment of a Post-Closure Pyrophoric Event

    International Nuclear Information System (INIS)

    Duguid, J.O.; Senger, R.K.; Leem, J.

    2002-01-01

    This paper describes analyses of a potential post-closure pyrophoric event in a waste package containing uranium metal spent fuel. The analyses include temperature at adjacent waste packages caused by the event and the dose to humans due to the event. The thermal analyses show that the event would not be expected to damage the adjacent waste packages. The dose analyses show that the doses due to the event are small. These analyses provide support to screening arguments used to demonstrate that the pyrophoric event should not be considered in the total system performance assessment model

  19. Assessment of galactic cosmic ray models

    Science.gov (United States)

    Mrigakshi, Alankrita Isha; Matthiä, Daniel; Berger, Thomas; Reitz, Günther; Wimmer-Schweingruber, Robert F.

    2012-08-01

    Among several factors involved in the development of a manned space mission concept, the astronauts' health is a major concern that needs to be considered carefully. Galactic cosmic rays (GCRs), which mainly consist of high-energetic nuclei ranging from hydrogen to iron and beyond, pose a major radiation health risk in long-term space missions. It is therefore required to assess the radiation exposure of astronauts in order to estimate their radiation risks. This can be done either by performing direct measurements or by making computer based simulations from which the dose can be derived. A necessary prerequisite for an accurate estimation of the exposure using simulations is a reliable description of the GCR spectra. The aim of this work is to compare GCR models and to test their applicability for the exposure assessment of astronauts. To achieve this, commonly used models capable of describing both light and heavy GCR particle spectra were evaluated by investigating the model spectra for various particles over several decades. The updated Badhwar-O'Neill model published in the year 2010, CREME2009 which uses the International Standard model for GCR, CREME96 and the Burger-Usoskin model were examined. Hydrogen, helium, oxygen and iron nuclei spectra calculated by the different models are compared with measurements from various high-altitude balloon and space-borne experiments. During certain epochs in the last decade, there are large discrepancies between the GCR energy spectra described by the models and the measurements. All the models exhibit weaknesses in describing the increased GCR flux that was observed in 2009-2010.

  20. CORPORATE FORESIGHT AND PERFORMANCE: A CHAIN-OF-EFFECTS MODEL

    DEFF Research Database (Denmark)

    Jissink, Tymen; Huizingh, Eelko K.R.E.; Rohrbeck, René

    2015-01-01

    , formal organization, and culture. We investigate the relation of corporate foresight with three innovation performance dimensions – new product success, new product innovativeness, and financial performance. We use partial-least-squares structural equations modelling to assess our measurement mode ls......In this paper we develop and validate a measurement scale for corporate foresight and examine its impact on performance in a chain-of-effects model. We conceptualize corporate foresight as an organizational ability consisting of five distinct dimensions: information scope, method usage, people...... performance dimensions. Implications of our findings, and limitations and future research avenues are discussed....

  1. Technical Basis for Assessing Uranium Bioremediation Performance

    International Nuclear Information System (INIS)

    PE Long; SB Yabusaki; PD Meyer; CJ Murray; AL N'Guessan

    2008-01-01

    In situ bioremediation of uranium holds significant promise for effective stabilization of U(VI) from groundwater at reduced cost compared to conventional pump and treat. This promise is unlikely to be realized unless researchers and practitioners successfully predict and demonstrate the long-term effectiveness of uranium bioremediation protocols. Field research to date has focused on both proof of principle and a mechanistic level of understanding. Current practice typically involves an engineering approach using proprietary amendments that focuses mainly on monitoring U(VI) concentration for a limited time period. Given the complexity of uranium biogeochemistry and uranium secondary minerals, and the lack of documented case studies, a systematic monitoring approach using multiple performance indicators is needed. This document provides an overview of uranium bioremediation, summarizes design considerations, and identifies and prioritizes field performance indicators for the application of uranium bioremediation. The performance indicators provided as part of this document are based on current biogeochemical understanding of uranium and will enable practitioners to monitor the performance of their system and make a strong case to clients, regulators, and the public that the future performance of the system can be assured and changes in performance addressed as needed. The performance indicators established by this document and the information gained by using these indicators do add to the cost of uranium bioremediation. However, they are vital to the long-term success of the application of uranium bioremediation and provide a significant assurance that regulatory goals will be met. The document also emphasizes the need for systematic development of key information from bench scale tests and pilot scales tests prior to full-scale implementation

  2. Technical Basis for Assessing Uranium Bioremediation Performance

    Energy Technology Data Exchange (ETDEWEB)

    PE Long; SB Yabusaki; PD Meyer; CJ Murray; AL N’Guessan

    2008-04-01

    In situ bioremediation of uranium holds significant promise for effective stabilization of U(VI) from groundwater at reduced cost compared to conventional pump and treat. This promise is unlikely to be realized unless researchers and practitioners successfully predict and demonstrate the long-term effectiveness of uranium bioremediation protocols. Field research to date has focused on both proof of principle and a mechanistic level of understanding. Current practice typically involves an engineering approach using proprietary amendments that focuses mainly on monitoring U(VI) concentration for a limited time period. Given the complexity of uranium biogeochemistry and uranium secondary minerals, and the lack of documented case studies, a systematic monitoring approach using multiple performance indicators is needed. This document provides an overview of uranium bioremediation, summarizes design considerations, and identifies and prioritizes field performance indicators for the application of uranium bioremediation. The performance indicators provided as part of this document are based on current biogeochemical understanding of uranium and will enable practitioners to monitor the performance of their system and make a strong case to clients, regulators, and the public that the future performance of the system can be assured and changes in performance addressed as needed. The performance indicators established by this document and the information gained by using these indicators do add to the cost of uranium bioremediation. However, they are vital to the long-term success of the application of uranium bioremediation and provide a significant assurance that regulatory goals will be met. The document also emphasizes the need for systematic development of key information from bench scale tests and pilot scales tests prior to full-scale implementation.

  3. VISUAL ART TEACHERS AND PERFORMANCE ASSESSMENT ...

    African Journals Online (AJOL)

    Charles

    students' attention away from the creative process. But even if this were true, it would not prevent the teacher from using the product as evidence to draw inferences about students' creativity and learning in art. Using finished products as a measurement strategy should not lead to using them exclusively in the assessment of ...

  4. H4: A model system for assessing the performance of diffusion Monte Carlo calculations using a single Slater determinant trial function.

    Science.gov (United States)

    Gasperich, Kevin; Deible, Michael; Jordan, Kenneth D

    2017-08-21

    A model H 4 system is used to investigate the accuracy of diffusion Monte Carlo (DMC) calculations employing a single Slater determinant to fix the nodal surface. The lowest energy singlet state of square H 4 is a diradical which is poorly described by DMC calculations using a single determinant (SD) trial function. Here we consider distortions to rectangular structures, which decrease the amount of diradical character. The falloff of the error in the SD-DMC energy with increasing separation between the two H 2 molecules is found to be much more rapid for small distortions away from square than for large distortions. This behavior is shown to be correlated with the extent of mixing between the two configurations needed to properly describe the diradical character. The error in the SD-DMC energy is found to be sizeable (∼0.1 eV) even for separations at which the coefficient of the dominant configuration in a four-electron, four-orbital complete active space self-consistent-field wave function is as large as 0.9.

  5. OMPS Limb Profiler Instrument Performance Assessment

    Science.gov (United States)

    Jaross, Glen R.; Bhartia, Pawan K.; Chen, Grace; Kowitt, Mark; Haken, Michael; Chen, Zhong; Xu, Philippe; Warner, Jeremy; Kelly, Thomas

    2014-01-01

    Following the successful launch of the Ozone Mapping and Profiler Suite (OMPS) aboard the Suomi National Polar-orbiting Partnership (SNPP) spacecraft, the NASA OMPS Limb team began an evaluation of instrument and data product performance. The focus of this paper is the instrument performance in relation to the original design criteria. Performance that is closer to expectations increases the likelihood that limb scatter measurements by SNPP OMPS and successor instruments can form the basis for accurate long-term monitoring of ozone vertical profiles. The team finds that the Limb instrument operates mostly as designed and basic performance meets or exceeds the original design criteria. Internally scattered stray light and sensor pointing knowledge are two design challenges with the potential to seriously degrade performance. A thorough prelaunch characterization of stray light supports software corrections that are accurate to within 1% in radiances up to 60 km for the wavelengths used in deriving ozone. Residual stray light errors at 1000nm, which is useful in retrievals of stratospheric aerosols, currently exceed 10%. Height registration errors in the range of 1 km to 2 km have been observed that cannot be fully explained by known error sources. An unexpected thermal sensitivity of the sensor also causes wavelengths and pointing to shift each orbit in the northern hemisphere. Spectral shifts of as much as 0.5nm in the ultraviolet and 5 nm in the visible, and up to 0.3 km shifts in registered height, must be corrected in ground processing.

  6. Performance assessment of Point Lepreau Generating Station

    International Nuclear Information System (INIS)

    Alikhan, S.

    1991-01-01

    The Point Lepreau Generating Station, a 680 MWe CANDU unit, is located about 40 km southwest of the city of Saint John, New Brunswick, Canada. It was declared in-service on 1 February, 1983 and, since then, has demonstrated an average cross capacity factor of over 93% up to the end of 1990. This paper compared the performance of the station with other sister CANDU units and the Light Water Reactors world-wide using the following ten performance indicators, as applicable: - gross capacity factor; - fuel burn-up; - heavy water upkeep; - unplanned reactor trips while critical; - forced outage rate; - fuel handling performance; - derived emission of radioactive effluents to environment; - personnel radiation dose; - industrial safety; - low-level solid radioactive wastes. The paper examines various areas of station activities including management and organization, operations and maintenance, technical support, fuel handling and health physics in order to highlight some of the 'good practices' which are believed to have made a significant contribution towards achieving the demonstrated performance of Point Lepreau G.S. In addition, several areas of potential improvement are discussed in order to maintain and enhance, where practicable, the safety, reliability and economic performance of the station. In this context, a careful review of the operating experiences, both in-house and at other stations, and a judicious application of lessons learned plays a significant role. (author)

  7. PERFORMANCE ASSESSMENT IN OPERATING DRY PORTS

    Directory of Open Access Journals (Sweden)

    Ciortescu Cezar-Gabriel

    2010-12-01

    Full Text Available In this paper, an approach for recognizing and defining correct and operable performance will be presented with the purpose of evaluating the effectiveness and efficiency of processes in dry ports (inland intermodal hubs. The challenge in evaluating the possible improvements of the underlying processes lies in the special nature and the complex structure of dry ports. It is important to consider that all the processes are highly interconnected and that changes in parameters in one process also have an impact on parameters in other processes. Furthermore, the performance of dry ports, seen as the backbone of the system, has a significant impact on the overall performance of the whole transportation network.

  8. Iowa calibration of MEPDG performance prediction models.

    Science.gov (United States)

    2013-06-01

    This study aims to improve the accuracy of AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) pavement : performance predictions for Iowa pavement systems through local calibration of MEPDG prediction models. A total of 130 : representative p...

  9. A Short History of Performance Assessment: Lessons Learned.

    Science.gov (United States)

    Madaus, George F.; O'Dwyer, Laura M.

    1999-01-01

    Places performance assessment in the context of high-stakes uses, describes underlying technologies, and outlines the history of performance testing from 210 B.C.E. to the present. Historical issues of fairness, efficiency, cost, and infrastructure influence contemporary efforts to use performance assessments in large-scale, high-stakes testing…

  10. Assessing Port Governance, Devolution and Terminal Performance in Nigeria

    Directory of Open Access Journals (Sweden)

    D. E. Onwuegbuchunam

    2018-02-01

    Full Text Available Concerns about performance and efficiency in port terminals led many national governments to embark on port reforms. The Federal government of Nigeria, for example, adopted the Landlord port model which brought about concessioning of port terminals to private operators. Despite high investments in terminal facilities by the private terminal operators, there are still complaints about level of service offered to port users. This paper applied key performance indicator metrics and parameters of queuing model in assessing performance of Nigeria’s concessioned port terminals. Data for the study were obtained from terminal level records of cargo and ship handling activities for years 2000 to 2015. Major findings indicate that cargo and vessel throughputs improved after the reforms in the six ports examined. However, much variability was observed in trends in ships’ turnround times across all ports after the concession policy implementation. Additional results from the queuing model analysis suggest that the high ships turnround times observed in some ports are associated to delays in ship operation at the berths. The paper recommends that policy interventions be focused on ship operations at the berths as a step in improving service level in the port terminals.

  11. Irrigation performance assessment in Crimea, Ukraine

    NARCIS (Netherlands)

    Pavlov, S.S.; Roerink, G.J.; Hellegers, P.J.G.J.; Popovych, V.F.

    2006-01-01

    After the collapse of the Soviet Union the performance of irrigated agriculture decreased drastically in Ukraine, due to problems related to the transition from a centrally planned economy to a market economy. Before formulating recommendations on required actions to modify this problematic

  12. Using urbanization profiles to assess screening performance

    NARCIS (Netherlands)

    Boon, ME; Kok, LP

    The large Dutch data sets acquired as a result of population-based cervical smear screening programs can be further exploited to obtain an urbanization-weighted score to gain insight into the quality of the performance of the individual cytology laboratories. Based on the first four digits of the

  13. Organizational Assessment: A Framework for Improving Performance

    International Development Research Centre (IDRC) Digital Library (Canada)

    The inability of development agencies to understand and improve the performance of the organizations they support continues to impede progress in the developing world, even after a decade of reforms. Strengthening the institutions that receive those grants and loans — including government ministries and executing ...

  14. Assessing heat exchanger performance data using temperature ...

    African Journals Online (AJOL)

    In addition, any calculated performance acceptance criteria must also consider uncertainty and error in the experimental measurements of temperature and flow. However, most statistical methods are complex and not easily applied to heat exchangers such as those that serve the power plant industry where data are difficult ...

  15. Identifying the connective strength between model parameters and performance criteria

    Directory of Open Access Journals (Sweden)

    B. Guse

    2017-11-01

    Full Text Available In hydrological models, parameters are used to represent the time-invariant characteristics of catchments and to capture different aspects of hydrological response. Hence, model parameters need to be identified based on their role in controlling the hydrological behaviour. For the identification of meaningful parameter values, multiple and complementary performance criteria are used that compare modelled and measured discharge time series. The reliability of the identification of hydrologically meaningful model parameter values depends on how distinctly a model parameter can be assigned to one of the performance criteria. To investigate this, we introduce the new concept of connective strength between model parameters and performance criteria. The connective strength assesses the intensity in the interrelationship between model parameters and performance criteria in a bijective way. In our analysis of connective strength, model simulations are carried out based on a latin hypercube sampling. Ten performance criteria including Nash–Sutcliffe efficiency (NSE, Kling–Gupta efficiency (KGE and its three components (alpha, beta and r as well as RSR (the ratio of the root mean square error to the standard deviation for different segments of the flow duration curve (FDC are calculated. With a joint analysis of two regression tree (RT approaches, we derive how a model parameter is connected to different performance criteria. At first, RTs are constructed using each performance criterion as the target variable to detect the most relevant model parameters for each performance criterion. Secondly, RTs are constructed using each parameter as the target variable to detect which performance criteria are impacted by changes in the values of one distinct model parameter. Based on this, appropriate performance criteria are identified for each model parameter. In this study, a high bijective connective strength between model parameters and performance criteria

  16. Individualized Biomathematical Modeling of Fatigue and Performance

    Science.gov (United States)

    2008-05-29

    waking period are omitted in order to avoid confounds from sleep inertia. Gray bars indicate scheduled sleep periods . (b) Performance predictions...i.e., total sleep deprivation; black). Light gray areas indicate nocturnal sleep periods . In this illustration, the bifurcation point is set to...confounds from sleep inertia. Gray bars indicate scheduled sleep periods . (b) Corresponding performance predictions according to the new model

  17. Tajikistan - Public Expenditure and Financial Accountability Assessment : Performance Report

    OpenAIRE

    World Bank

    2007-01-01

    This assessment is based on work undertaken between October 2006 and May 2007. The summary assessment covers the following three areas: an integrated assessment of PFM performance based on the 28+3 PEFA indicators, an assessment of the impact of PFM weaknesses, and the prospects for reform planning and implementation. The main report consists of four sections: an introduction, the country ...

  18. Reliable and Valid Assessment of Clinical Bronchoscopy Performance

    DEFF Research Database (Denmark)

    Konge, Lars; Larsen, Klaus Richter; Clementsen, Paul

    2012-01-01

    Background: There have been several attempts to systematically assess performance in bronchoscopy. Earlier validation studies have used bronchoscopy simulators, not real-life performance in patients. Objectives: The aim of this study was to explore the reliability and validity of an assessment tool...... aspects of the assessment, but post hoc tests showed different discriminative abilities. Conclusions: This new tool for assessing clinical bronchoscopy performance has a high interrater reliability. One rater assessing performance of 3 bronchoscopies ensures sufficient reliability. The assessment tool......: The interrater reliability was high, with Cronbach's a = 0.86. Assessment of 3 bronchoscopies by a single rater had a generalizability coefficient of 0.84. The correlation between experience and performance was good (Pearson correlation = 0.76). There were significant differences between the groups for all...

  19. Performance objectives for the Hanford Immobilized Low-Activity Waste (ILAW) performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    MANN, F.M.

    1999-03-17

    Performance objectives for the disposal of low activity waste from Hanford Waste Tanks have been developed. These objectives have been based on DOE requirements, programmatic requirements, and public involvement. The DOE requirements include regulations that direct the performance assessment and are cited within the Radioactive Waste Management Order (DOE Order 435.1). Performance objectives for other DOE complex performance assessments have been included.

  20. WIPP performance assessment: impacts of human intrusion

    International Nuclear Information System (INIS)

    Anderson, D.R.; Hunter, R.L.; Bertram-Howery, S.G.; Lappin, A.R.

    1989-01-01

    The Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico is a research and development facility that may become the USA's first and only mined geologic repository for transuranic waste. Human intrusion into the WIPP repository after closure has been shown by preliminary sensitivity analyses and calculations of consequences to be an important, and perhaps the most important, factor in long-term repository performance

  1. Mass Casualty Triage Performance Assessment Tool

    Science.gov (United States)

    2015-02-01

    Jonathan J. Bryson Heidi Keller-Glaze ICF International Christopher L. Vowels U.S. Army Research Institute February 2015 United...Christopher L. Vowels 5c. PROJECT NUMBER A790 5d. TASK NUMBER 5e. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES...Contracting Officer’s Representative and Subject Matter POC: Dr. Christopher L. Vowels 14. ABSTRACT (Maximum 200 words): This report

  2. Ability Of Mathematical Reasoning in SMK 10th Grade with LAPS- Heuristic using Performance Assessment

    Directory of Open Access Journals (Sweden)

    Aulia Nur Arivina

    2017-11-01

    Full Text Available The purposes of this research are: (1 Test the learning with LAPS-Heuristic model using performance assessment on 10th grade of Trigonometry material is complete, (2 to test the difference of students' mathematical reasoning ability on 10th grade of Trigonometry material between the learning model of LAPS-Heuristic using performance assessment, LAPS-Heuristic learning model with Expository learning model, (3 test the ability of mathematical reasoning with learning model of LAPS-Heuristik on Trigonometry material of SMK on 10th grade using performance assessment is increase. This is a quantitative research. The population is students of 10th grade of SMK 10 Semarang academic year 2016/2017 and the subject of research is selected by clustering random sampling. The results show that (1 Learning by model LAPS-Heuristic using performance assessment on 10th grade of Trigonometry material is complete (2 there are differences in students' mathematical reasoning ability on 10th grade of Trigonometry materials between LAPS-Heuristic learning model using performance assessment, LAPS-Heuristic learning model, and Expository learning model, (3 The ability of mathematical reasoning with learning model of LAPS-Heuristic on Trigonometry material of SMK class X using performance assessment increased.

  3. Driver Performance Model: 1. Conceptual Framework

    National Research Council Canada - National Science Library

    Heimerl, Joseph

    2001-01-01

    ...'. At the present time, no such comprehensive model exists. This report discusses a conceptual framework designed to encompass the relationships, conditions, and constraints related to direct, indirect, and remote modes of driving and thus provides a guide or 'road map' for the construction and creation of a comprehensive driver performance model.

  4. Analysing the temporal dynamics of model performance for hydrological models

    NARCIS (Netherlands)

    Reusser, D.E.; Blume, T.; Schaefli, B.; Zehe, E.

    2009-01-01

    The temporal dynamics of hydrological model performance gives insights into errors that cannot be obtained from global performance measures assigning a single number to the fit of a simulated time series to an observed reference series. These errors can include errors in data, model parameters, or

  5. Dose assessment models. Annex A

    International Nuclear Information System (INIS)

    1982-01-01

    The models presented in this chapter have been separated into 2 general categories: environmental transport models which describe the movement of radioactive materials through all sectors of the environment after their release, and dosimetric models to calculate the absorbed dose following an intake of radioactive materials or exposure to external irradiation. Various sections of this chapter also deal with atmospheric transport models, terrestrial models, and aquatic models.

  6. Total System Performance Assessment - License Application Methods and Approach

    Energy Technology Data Exchange (ETDEWEB)

    J. McNeish

    2003-12-08

    ''Total System Performance Assessment-License Application (TSPA-LA) Methods and Approach'' provides the top-level method and approach for conducting the TSPA-LA model development and analyses. The method and approach is responsive to the criteria set forth in Total System Performance Assessment Integration (TSPAI) Key Technical Issues (KTIs) identified in agreements with the U.S. Nuclear Regulatory Commission, the ''Yucca Mountain Review Plan'' (YMRP), ''Final Report'' (NRC 2003 [163274]), and the NRC final rule 10 CFR Part 63 (NRC 2002 [156605]). This introductory section provides an overview of the TSPA-LA, the projected TSPA-LA documentation structure, and the goals of the document. It also provides a brief discussion of the regulatory framework, the approach to risk management of the development and analysis of the model, and the overall organization of the document. The section closes with some important conventions that are used in this document.

  7. Biofilm carrier migration model describes reactor performance.

    Science.gov (United States)

    Boltz, Joshua P; Johnson, Bruce R; Takács, Imre; Daigger, Glen T; Morgenroth, Eberhard; Brockmann, Doris; Kovács, Róbert; Calhoun, Jason M; Choubert, Jean-Marc; Derlon, Nicolas

    2017-06-01

    The accuracy of a biofilm reactor model depends on the extent to which physical system conditions (particularly bulk-liquid hydrodynamics and their influence on biofilm dynamics) deviate from the ideal conditions upon which the model is based. It follows that an improved capacity to model a biofilm reactor does not necessarily rely on an improved biofilm model, but does rely on an improved mathematical description of the biofilm reactor and its components. Existing biofilm reactor models typically include a one-dimensional biofilm model, a process (biokinetic and stoichiometric) model, and a continuous flow stirred tank reactor (CFSTR) mass balance that [when organizing CFSTRs in series] creates a pseudo two-dimensional (2-D) model of bulk-liquid hydrodynamics approaching plug flow. In such a biofilm reactor model, the user-defined biofilm area is specified for each CFSTR; thereby, X carrier does not exit the boundaries of the CFSTR to which they are assigned or exchange boundaries with other CFSTRs in the series. The error introduced by this pseudo 2-D biofilm reactor modeling approach may adversely affect model results and limit model-user capacity to accurately calibrate a model. This paper presents a new sub-model that describes the migration of X carrier and associated biofilms, and evaluates the impact that X carrier migration and axial dispersion has on simulated system performance. Relevance of the new biofilm reactor model to engineering situations is discussed by applying it to known biofilm reactor types and operational conditions.

  8. Application of the Biosphere Assessment Methodology to the ENRESA, 1997 Performance and Safety Assessment

    International Nuclear Information System (INIS)

    Pinedo, P.; Simon, I.; Aguero, A.

    1998-01-01

    For several years CIEMAT has been developing for ENRESA knowledge and tools to support the modelling of the migration and accumulation of radionuclides within the biosphere once those radionuclides are released or reach one or more parts of the biosphere (atmosphere, water bodies or soils). The model development also includes evaluation of radiological impacts arising from the resulting distribution of radionuclides in the biosphere. In 1996, a Methodology to analyse the biosphere in this context proposed to ENRESA. The level of development of the different aspects proposed within the Methodology was quite heterogeneous and, while aspects of radionuclide transport modelling were already well developed in theoretical and practical terms, other aspects like the procedure for conceptual model development and the description of biosphere system representatives of the long term needed further developments. At present, the International Atomic Energy Agency (IAEA) Programme on Biosphere Modelling and Assessment (BIOMASS) in collaboration with several national organizations, ENRESA and CIEMAT among them, is working to complete and augment the Reference Biosphere Methodology and to produce some practical descriptions of Reference Systems. The overall purpose of this document is to apply the Methodology, taking account of on-going developments in biosphere modelling, to the last performance assessment (PA) exercise made by ENRESA (ENRESA, 1997), using from it the general and particular information about the assessment context, radionuclide information, geosphere and geobiosphere interface data. There are three particular objectives to this work: (a) to determine the practicability of the Methodology in an application to a realistic assessment situation, (b) To compare and contrast previous biosphere modelling in HLW PA and, (c) to test software development related with data management and modelling. (Author) 42 refs

  9. The role of performance assessment in radioactive waste disposal

    International Nuclear Information System (INIS)

    Stenhouse, M.J.

    1998-01-01

    Performance assessment has many applications in the field of radioactive waste management, none more important than demonstrating the suitability of a particular repository system for waste disposal. The role of performance assessment in radioactive waste disposal is discussed with reference to assessments performed in civilian waste management programmes. The process is, however, relevant, and may be applied directly to the disposal of defence-related wastes. When used in an open and transparent manner, performance assessment is a powerful methodology not only for convincing the authorities of the safety of a disposal concept, but also for gaining the wider acceptance of the general public for repository siting. 26 refs

  10. Developing Performance-Based Assessments of Mariner Proficiency

    National Research Council Canada - National Science Library

    McCallum, Marvin

    2001-01-01

    The present study explored the requirements for developing and documenting performance-based assessments that would conform to the amended Seafarers' Training, Certification and Watchkeeping (STCW) Code...

  11. Performance modeling, loss networks, and statistical multiplexing

    CERN Document Server

    Mazumdar, Ravi

    2009-01-01

    This monograph presents a concise mathematical approach for modeling and analyzing the performance of communication networks with the aim of understanding the phenomenon of statistical multiplexing. The novelty of the monograph is the fresh approach and insights provided by a sample-path methodology for queueing models that highlights the important ideas of Palm distributions associated with traffic models and their role in performance measures. Also presented are recent ideas of large buffer, and many sources asymptotics that play an important role in understanding statistical multiplexing. I

  12. Predicting work Performance through selection interview ratings and Psychological assessment

    Directory of Open Access Journals (Sweden)

    Liziwe Nzama

    2008-11-01

    Full Text Available The aim of the study was to establish whether selection interviews used in conjunction with psychological assessments of personality traits and cognitive functioning contribute to predicting work performance. The sample consisted of 102 managers who were appointed recently in a retail organisation. The independent variables were selection interview ratings obtained on the basis of structured competency-based interview schedules by interviewing panels, fve broad dimensions of personality defned by the Five Factor Model as measured by the 15 Factor Questionnaire (15FQ+, and cognitive processing variables (current level of work, potential level of work, and 12 processing competencies measured by the Cognitive Process Profle (CPP. Work performance was measured through annual performance ratings that focused on measurable outputs of performance objectives. Only two predictor variables correlated statistically signifcantly with the criterion variable, namely interview ratings (r = 0.31 and CPP Verbal Abstraction (r = 0.34. Following multiple regression, only these variables contributed signifcantly to predicting work performance, but only 17.8% of the variance of the criterion was accounted for.

  13. Evaluation Model of Organizational Performance for Small and Medium Enterprises

    Directory of Open Access Journals (Sweden)

    Carlos Augusto Passos

    2014-12-01

    Full Text Available In the 1980’s, many tools for evaluating organizational performance were created. However, most of them are useful only to large companies and do not foster results in small and medium-sized enterprises (SMEs. In light of this fact, this article aims at proposing an Organizational Performance Assessment model (OPA which is flexible and adaptable to the reality of SMEs, based on the theoretical framework of various models, and comparisons on the basis of three major authors’ criteria to evaluate OPA models. The research has descriptive and exploratory character, with qualitative nature. The MADE-O model, according to the criteria described in the bibliography, is the one that best fits the needs of SMEs, used as a baseline for the model proposed in this study with adaptations pertaining to the BSC model. The model called the Overall Performance Indicator – Environment (IDG-E has as its main differential, in addition to the base of the models mentioned above, the assessment of the external and internal environment weighted in modules of OPA. As the SME is characterized by having few processes and people, the small amount of performance indicators is another positive aspect. Submitted to the evaluation of the criteria subscribed by the authors, the model proved to be quite feasible for use in SMEs.

  14. Advances in HTGR fuel performance models

    International Nuclear Information System (INIS)

    Stansfield, O.M.; Goodin, D.T.; Hanson, D.L.; Turner, R.F.

    1985-01-01

    Advances in HTGR fuel performance models have improved the agreement between observed and predicted performance and contributed to an enhanced position of the HTGR with regard to investment risk and passive safety. Heavy metal contamination is the source of about 55% of the circulating activity in the HTGR during normal operation, and the remainder comes primarily from particles which failed because of defective or missing buffer coatings. These failed particles make up about 5 x 10 -4 fraction of the total core inventory. In addition to prediction of fuel performance during normal operation, the models are used to determine fuel failure and fission product release during core heat-up accident conditions. The mechanistic nature of the models, which incorporate all important failure modes, permits the prediction of performance from the relatively modest accident temperatures of a passively safe HTGR to the much more severe accident conditions of the larger 2240-MW/t HTGR. (author)

  15. On the choice of performance assessment criteria and their impact on the overall system performance

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Green, Torben

    2010-01-01

    The aim of this paper is to illuminate the impact of the choice of a system’s performance criteria on the quality of the corresponding monitoring system’s assessment results. Special attention is given to the performance issues that are caused by or can be solved by control actions. The compressor...... capacity gap issue in the supermarket refrigeration systems is used as a case study to elaborate on the problem through employment of both real life field data as well as simulation data. A performance function that can capture the compressor capacity gap problem is presented in the paper and used...... to evaluate both data from the real supermarket system and the data generated by the simulation model....

  16. Performance Evaluation Model for Application Layer Firewalls.

    Directory of Open Access Journals (Sweden)

    Shichang Xuan

    Full Text Available 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.

  17. Performance Evaluation Model for Application Layer Firewalls.

    Science.gov (United States)

    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.

  18. Performance Assessment as a Diagnostic Tool for Science Teachers

    Science.gov (United States)

    Kruit, Patricia; Oostdam, Ron; van den Berg, Ed; Schuitema, Jaap

    2018-04-01

    Information on students' development of science skills is essential for teachers to evaluate and improve their own education, as well as to provide adequate support and feedback to the learning process of individual students. The present study explores and discusses the use of performance assessments as a diagnostic tool for formative assessment to inform teachers and guide instruction of science skills in primary education. Three performance assessments were administered to more than 400 students in grades 5 and 6 of primary education. Students performed small experiments using real materials while following the different steps of the empirical cycle. The mutual relationship between the three performance assessments is examined to provide evidence for the value of performance assessments as useful tools for formative evaluation. Differences in response patterns are discussed, and the diagnostic value of performance assessments is illustrated with examples of individual student performances. Findings show that the performance assessments were difficult for grades 5 and 6 students but that much individual variation exists regarding the different steps of the empirical cycle. Evaluation of scores as well as a more substantive analysis of students' responses provided insight into typical errors that students make. It is concluded that performance assessments can be used as a diagnostic tool for monitoring students' skill performance as well as to support teachers in evaluating and improving their science lessons.

  19. Total System Performance Assessment Code (TOSPAC)

    International Nuclear Information System (INIS)

    Gauthier, J.H.; Dudley, A.L.; Skinner, L.H.; Wilson, M.L.; Peters, R.R.

    1992-07-01

    TOSPAC is a computer program that calculates partially saturated groundwater flow with the transport of water-soluble contaminants. TOSPAC Version 1 is restricted to calculations involving one-dimensional, vertical columns of one or more media. TOSPAC was developed to help answer questions surrounding the burial of toxic wastes in arid regions. Burial of wastes in arid regions is attractive because of generally low population densities and little groundwater flow, in the unsaturated zone, to disturb the waste. TOSPAC helps to quantify groundwater flow and the spread of contamination, offering an idea of what could happen in the distant future. Figure 1.1 illustrates the problem TOSPAC was designed to investigate. For groundwater flow, TOSPAC can provide saturations, velocities, and and travel tunes for water in the rock matrix or the fractures in the unsaturated zone. TOSPAC can determine how hydrologic conditions vary when the rate of infiltration changes. For contaminant transport, TOSPAC can compute how much of a contaminant is dissolved in the water and how it is distributed. TOSPAC can determine how fast the solute is moving and the shape of the concentration front. And TOSPAC can be used to investigate how much of the contaminant remains in the inventory of a repository, how much is adsorbed onto the soil or rock matrix, and how much reaches the water table. Effective use of TOSPAC requires knowledge in a number of diverse disciplines, including real groundwater flow and transport, the mathematical models of groundwater flow and transport, real-world data required for the models, and the numerical solution of differential equations. Equally important is a realization of the limitations intrinsic to a computer model of complex physical phenomena. This User's Guide not only describes the mechanics of executing TOSPAC on a computer, but also examines these other topics

  20. Assessment of Ballistic Performance for Transparent Material

    Directory of Open Access Journals (Sweden)

    Basim M. Fadhil

    2014-05-01

    Full Text Available A finite element method was used to investigate the ballistic behavior of Polymethylmethacrylate (PMMA under impact loading by spherical steel projectile with different ranges of velocities. Three different target thicknesses were used in the experimental and the numerical works. A mathematical model has been used for the ballistic limit based on the experimental results. It has been found that projectile velocity and target thickness play an important role in the ballistic behavior of PMMA. A good agreement was found between the numerical, experimental, and the analytical result.

  1. Beginning science teachers' performances: Assessment in times of reform

    Science.gov (United States)

    Budzinsky, Fie K.

    2000-10-01

    The current reform in science education and the research on effective teaching and student learning have reinforced the importance of teacher competency. To better measure performances in the teaching of science, performance assessment has been added to Connecticut's licensure process for beginning science teachers. Teaching portfolios are used to document teaching and learning over time. Portfolios, however, are not without problems. One of the major concerns with the portfolio assessment process is its subjectivity. Assessors may not have opportunities to ask clarifying or follow-up questions to enhance the interpretation of a teacher's performance. In addition, portfolios often contain components based on self-documentation, which are subjective. Furthermore, the use of portfolios raises test equity issues. These concerns present challenges for persons in charge of establishing the validity of a portfolio-based licensure process. In high-stakes decision processes, such as teaching licensure, the validity of the assessment instruments must be studied. The primary purpose of this study was to explore the criterion-related validity of the Connecticut State Department of Education's Beginning Science Teaching Portfolio by comparing the interpretations of performances from science teaching portfolios to those derived from another assessment method, the Expert Science Teaching Educational and Evaluation Model, (ESTEEM). The analysis of correlations between the Beginning Science Teaching Portfolio and ESTEEM instrument scores was the primary method for establishing support for validity. The results indicated moderate correlations between all Beginning Science Teaching Portfolio and ESTEEM category and total variables. Multiple regression was used to examine whether differences existed in beginning science teachers' performances based on gender, poverty group, school level, and science discipline taught. None of these variables significantly contributed to the

  2. Assessing Bus Performance Rating in Kajang, Selangor

    Science.gov (United States)

    Norhisham, S.; Ismail, A.; Sidek, L. M.; Borhan, M. N.; Zaini, N.; Yen, A. T. G.

    2018-04-01

    The Transit Capacity and Quality of Service Manual (TCQSM) was chosen based on the review with four manuals and guidelines for the method will be applied. Six (6) attributes, namely Hours of Service, Passenger Load, Transit Auto Travel Time, Service Frequency, Punctuality Performance and Service Coverage were chosen for evaluation.[6][7][8]. A total of three (3) operators with seven (7) routes were identified in Kajang. Based on the final results, the Quality of Service (QOS) findings was rated as D, which was regarded as minimum or satisfactory. Most stakeholders’ recommendations were: for the operators to provide information on bus scheduling and have accurate information for the passengers. It was suggested that in future this study can be extended to all routes and could be repeated after the opening of the Mass Rapid Transit (MRT) stations in Kajang, so as to provide a comparison and better evaluation of the public buses in Kajang.

  3. Synchronous and Cogged Fan Belt Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, Dylan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dean, Jesse [National Renewable Energy Lab. (NREL), Golden, CO (United States); Acosta, Jason [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-02-01

    The GSA Regional GPG Team commissioned the National Renewable Energy Laboratory (NREL) to perform monitoring of cogged V-belts and synchronous belts on both a constant volume and a variable air volume fan at the Byron G. Rodgers Federal Building and U.S. Courthouse in Denver, Colorado. These motor/fan combinations were tested with their original, standard V-belts (appropriately tensioned by an operation and maintenance professional) to obtain a baseline for standard operation. They were then switched to the cogged V-belts, and finally to synchronous belts. The power consumption by the motor was normalized for both fan speed and air density changes. This was necessary to ensure that the power readings were not influenced by a change in rotational fan speed or by the power required to push denser air. Finally, energy savings and operation and maintenance savings were compiled into an economic life-cycle cost analysis of the different belt options.

  4. Evaluating the Performance of DFT Functionals in Assessing the Interaction Energy and Ground-State Charge Transfer of Donor/Acceptor Complexes: Tetrathiafulvalene−Tetracyanoquinodimethane (TTF−TCNQ) as a Model Case

    KAUST Repository

    Sini, Gjergji

    2011-03-08

    We have evaluated the performance of several density functional theory (DFT) functionals for the description of the ground-state electronic structure and charge transfer in donor/acceptor complexes. The tetrathiafulvalene- tetracyanoquinodimethane (TTF-TCNQ) complex has been considered as a model test case. Hybrid functionals have been chosen together with recently proposed long-range corrected functionals (ωB97X, ωB97X-D, LRC-ωPBEh, and LC-ωPBE) in order to assess the sensitivity of the results to the treatment and magnitude of exact exchange. The results show an approximately linear dependence of the ground-state charge transfer with the HOMO TTF-LUMOTCNQ energy gap, which in turn depends linearly on the percentage of exact exchange in the functional. The reliability of ground-state charge transfer values calculated in the framework of a monodeterminantal DFT approach was also examined. © 2011 American Chemical Society.

  5. Performance Assessment Assistance Activities in the DOE Complex - 12325

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, Roger R.; Phifer, Mark A. [Savannah River National Laboratory, Savannah River Site, Bldg 773-43A, Aiken, SC 29808 (United States); Letourneau, Martin J. [U.S. Department of Energy, EM-41 19901 Germantown Road, Germantown, MD 20874-1290 (United States)

    2012-07-01

    The United States Department of Energy Office of Environmental Management (DOE-EM) has established a Performance Assessment Community of Practice (PA CoP) to foster the sharing of information among performance assessment (PA) and risk assessment practitioners, regulators and oversight personnel. The general intent is to contribute to continuous improvement in the consistency, technical adequacy and quality of implementation of PAs and risk assessments around the DOE Complex. The PA CoP activities have involved commercial disposal facilities and international participants to provide a global perspective. The PA CoP has also sponsored annual technical exchanges as a means to foster improved communication and to share lessons learned from on-going modelling activities. The PA CoP encourages activities to provide programmatic and technical assistance in the form of sharing experience and lessons learned with practitioners during the development of PAs and risk assessments. This assistance complements DOE-EM reviews through the Low-Level Waste Disposal Facility Federal Review Group (LFRG) that are conducted after modelling efforts are completed. Such up-front assistance is providing additional value in terms of improving consistency and sharing of information. There has been a substantial increase in the amount of assistance being provided. The assistance has been well received by practitioners and regulators that have been involved. The paper highlights assistance and sharing of information that has been conducted in the last two years to support activities underway in support of proposed disposal facilities at Paducah, Portsmouth, and the Idaho National Laboratory and tank closure at Hanford. DOE-EM established the PA CoP to help improve the consistency and quality of implementation of modelling activities around the DOE Complex. The PA CoP has sponsored annual technical exchanges as a means to foster improved communication and to share lessons learned from ongoing

  6. Estuarine modeling: Does a higher grid resolution improve model performance?

    Science.gov (United States)

    Ecological models are useful tools to explore cause effect relationships, test hypothesis and perform management scenarios. A mathematical model, the Gulf of Mexico Dissolved Oxygen Model (GoMDOM), has been developed and applied to the Louisiana continental shelf of the northern ...

  7. Developing an Energy Performance Modeling Startup Kit

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2012-10-01

    In 2011, the NAHB Research Center began assessing the needs and motivations of residential remodelers regarding energy performance remodeling. This report outlines: the current remodeling industry and the role of energy efficiency; gaps and barriers to adding energy efficiency into remodeling; and support needs of professional remodelers to increase sales and projects involving improving home energy efficiency.

  8. Critical review of glass performance modeling

    International Nuclear Information System (INIS)

    Bourcier, W.L.

    1994-07-01

    Borosilicate glass is to be used for permanent disposal of high-level nuclear waste in a geologic repository. Mechanistic chemical models are used to predict the rate at which radionuclides will be released from the glass under repository conditions. The most successful and useful of these models link reaction path geochemical modeling programs with a glass dissolution rate law that is consistent with transition state theory. These models have been used to simulate several types of short-term laboratory tests of glass dissolution and to predict the long-term performance of the glass in a repository. Although mechanistically based, the current models are limited by a lack of unambiguous experimental support for some of their assumptions. The most severe problem of this type is the lack of an existing validated mechanism that controls long-term glass dissolution rates. Current models can be improved by performing carefully designed experiments and using the experimental results to validate the rate-controlling mechanisms implicit in the models. These models should be supported with long-term experiments to be used for model validation. The mechanistic basis of the models should be explored by using modern molecular simulations such as molecular orbital and molecular dynamics to investigate both the glass structure and its dissolution process

  9. Critical review of glass performance modeling

    Energy Technology Data Exchange (ETDEWEB)

    Bourcier, W.L. [Lawrence Livermore National Lab., CA (United States)

    1994-07-01

    Borosilicate glass is to be used for permanent disposal of high-level nuclear waste in a geologic repository. Mechanistic chemical models are used to predict the rate at which radionuclides will be released from the glass under repository conditions. The most successful and useful of these models link reaction path geochemical modeling programs with a glass dissolution rate law that is consistent with transition state theory. These models have been used to simulate several types of short-term laboratory tests of glass dissolution and to predict the long-term performance of the glass in a repository. Although mechanistically based, the current models are limited by a lack of unambiguous experimental support for some of their assumptions. The most severe problem of this type is the lack of an existing validated mechanism that controls long-term glass dissolution rates. Current models can be improved by performing carefully designed experiments and using the experimental results to validate the rate-controlling mechanisms implicit in the models. These models should be supported with long-term experiments to be used for model validation. The mechanistic basis of the models should be explored by using modern molecular simulations such as molecular orbital and molecular dynamics to investigate both the glass structure and its dissolution process.

  10. Performance modeling, stochastic networks, and statistical multiplexing

    CERN Document Server

    Mazumdar, Ravi R

    2013-01-01

    This monograph presents a concise mathematical approach for modeling and analyzing the performance of communication networks with the aim of introducing an appropriate mathematical framework for modeling and analysis as well as understanding the phenomenon of statistical multiplexing. The models, techniques, and results presented form the core of traffic engineering methods used to design, control and allocate resources in communication networks.The novelty of the monograph is the fresh approach and insights provided by a sample-path methodology for queueing models that highlights the importan

  11. Performance assessment and licensing issues for United States commercial near-surface low-level radioactive waste disposal facilities

    International Nuclear Information System (INIS)

    Birk, S. M.

    1997-01-01

    This paper covers the performance assessment and licensing issues, the performance the objectives, the performance assessment phases, the scenario selection, the mathematical modeling and computer programs, the final results of performance assessments submitted for license applications, the institutional control period, and the licensing issues. 38 refs

  12. Broadening Perspectives on Clinical Performance Assessment: Rethinking the Nature of In-Training Assessment

    Science.gov (United States)

    Govaerts, Marjan J. B.; van der Vleuten, Cees P. M.; Schuwirth, Lambert W. T.; Muijtjens, Arno M. M.

    2007-01-01

    Context: In-training assessment (ITA), defined as multiple assessments of performance in the setting of day-to-day practice, is an invaluable tool in assessment programmes which aim to assess professional competence in a comprehensive and valid way. Research on clinical performance ratings, however, consistently shows weaknesses concerning…

  13. Modeling for operational event risk assessment

    International Nuclear Information System (INIS)

    Sattison, M.B.

    1997-01-01

    The U.S. Nuclear Regulatory Commission has been using risk models to evaluate the risk significance of operational events in U.S. commercial nuclear power plants for more seventeen years. During that time, the models have evolved in response to the advances in risk assessment technology and insights gained with experience. Evaluation techniques fall into two categories, initiating event assessments and condition assessments. The models used for these analyses have become uniquely specialized for just this purpose

  14. Sensitivity Assessment of Ozone Models

    Energy Technology Data Exchange (ETDEWEB)

    Shorter, Jeffrey A.; Rabitz, Herschel A.; Armstrong, Russell A.

    2000-01-24

    The activities under this contract effort were aimed at developing sensitivity analysis techniques and fully equivalent operational models (FEOMs) for applications in the DOE Atmospheric Chemistry Program (ACP). MRC developed a new model representation algorithm that uses a hierarchical, correlated function expansion containing a finite number of terms. A full expansion of this type is an exact representation of the original model and each of the expansion functions is explicitly calculated using the original model. After calculating the expansion functions, they are assembled into a fully equivalent operational model (FEOM) that can directly replace the original mode.

  15. The Assessment of School Performance in Big City School Systems.

    Science.gov (United States)

    Roaden, Arliss L.

    Data and comment are presented on the methodologies of four recent studies which assessed school performance in cities experiencing unrest and conflict (Cincinnati, Columbus, Detroit, and Washington, D.C.). The topics of primary concern are (1) the school performance objectives that were assessed, (2) the methods and tools used by the…

  16. Analytical