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Sample records for flow modeling conceptual

  1. Assessing alternative conceptual models of fracture flow

    International Nuclear Information System (INIS)

    Ho, C.K.

    1995-01-01

    The numerical code TOUGH2 was used to assess alternative conceptual models of fracture flow. The models that were considered included the equivalent continuum model (ECM) and the dual permeability (DK) model. A one-dimensional, layered, unsaturated domain was studied with a saturated bottom boundary and a constant infiltration at the top boundary. Two different infiltration rates were used in the studies. In addition, the connection areas between the fracture and matrix elements in the dual permeability model were varied. Results showed that the two conceptual models of fracture flow produced different saturation and velocity profiles-even under steady-state conditions. The magnitudes of the discrepancies were sensitive to two parameters that affected the flux between the fractures and matrix in the dual permeability model: (1) the fracture-matrix connection areas and (2) the capillary pressure gradients between the fracture and matrix elements

  2. Conceptual and Numerical Models for UZ Flow and Transport

    International Nuclear Information System (INIS)

    Liu, H.

    2000-01-01

    The purpose of this Analysis/Model Report (AMR) is to document the conceptual and numerical models used for modeling of unsaturated zone (UZ) fluid (water and air) flow and solute transport processes. This is in accordance with ''AMR Development Plan for U0030 Conceptual and Numerical Models for Unsaturated Zone (UZ) Flow and Transport Processes, Rev 00''. The conceptual and numerical modeling approaches described in this AMR are used for models of UZ flow and transport in fractured, unsaturated rock under ambient and thermal conditions, which are documented in separate AMRs. This AMR supports the UZ Flow and Transport Process Model Report (PMR), the Near Field Environment PMR, and the following models: Calibrated Properties Model; UZ Flow Models and Submodels; Mountain-Scale Coupled Processes Model; Thermal-Hydrologic-Chemical (THC) Seepage Model; Drift Scale Test (DST) THC Model; Seepage Model for Performance Assessment (PA); and UZ Radionuclide Transport Models

  3. Comparison of two conceptual models of flow using the TSA

    International Nuclear Information System (INIS)

    Wilson, M.L.

    1992-01-01

    Several new capabilities have been added to the Total-System Analyzer (TSA), including a new model of unsaturated flow and transport, two new models of source releases, a different computational method for saturated transport, and gas-release capability. In this paper these new capabilities are described, and a comparison is made of results from the two different conceptual models of unsaturated flow that are now part of the TSA, a composite-porosity model and a simple fracture-flow model

  4. Geomorphic dam-break flows. Part I: conceptual model

    OpenAIRE

    Leal, JGAB; Ferreira, RML; Cardoso, AH

    2010-01-01

    Proceedings of the Institution of Civil Engineers - Water Management 163 Issue WM6 This paper presents a one-dimensional conceptual model for simulating geomorphic dam-break flows. The model is based on conservation laws drawn from continuum mixture theory that are integrated over the flow depth,assuming that the f10w is composed of two transport layers. Closure equations were derived from the review and reanalysis of previous studies on granular flow,debris f10w and sheet flow. The sedime...

  5. Comparison of two conceptual models of flow using the TSA

    International Nuclear Information System (INIS)

    Wilson, M.L.

    1992-01-01

    As part of the performance-assessment task for the potential repository site at Yucca Mountain, Nevada, Sandia National Laboratories is developing a set of programs called the Total-System Analyzer (TSA). The TSA is one of the tools being used in the current effort to provide a systematic preliminary estimate the total-system performance of the Yucca Mountain site. The purposes of this paper are twofold: (1) to describe capabilities that have been added to the TSA in the last year; and (2) to present a comparison of two conceptual models of unsaturated-zone flow and transport, in terms of the performance measure specified by the Environmental Protection Agency (EPA) in 40 CFR Part 191. The conceptual-model comparison is intended to demonstrate the new TSA capabilities and at the same time shed some light on the performance implications of fracture flow at Yucca Mountain. Unsaturated fracture flow is not yet well understood, and it is of great importance in determining the performance of Yucca Mountain

  6. Conceptual Model and Numerical Approaches for Unsaturated Zone Flow and Transport

    International Nuclear Information System (INIS)

    H.H. Liu

    2004-01-01

    The purpose of this model report is to document the conceptual and numerical models used for modeling unsaturated zone (UZ) fluid (water and air) flow and solute transport processes. This work was planned in ''Technical Work Plan for: Unsaturated Zone Flow Model and Analysis Report Integration'' (BSC 2004 [DIRS 169654], Sections 1.2.5, 2.1.1, 2.1.2 and 2.2.1). The conceptual and numerical modeling approaches described in this report are mainly used for models of UZ flow and transport in fractured, unsaturated rock under ambient conditions. Developments of these models are documented in the following model reports: (1) UZ Flow Model and Submodels; (2) Radionuclide Transport Models under Ambient Conditions. Conceptual models for flow and transport in unsaturated, fractured media are discussed in terms of their applicability to the UZ at Yucca Mountain. The rationale for selecting the conceptual models used for modeling of UZ flow and transport is documented. Numerical approaches for incorporating these conceptual models are evaluated in terms of their representation of the selected conceptual models and computational efficiency; and the rationales for selecting the numerical approaches used for modeling of UZ flow and transport are discussed. This report also documents activities to validate the active fracture model (AFM) based on experimental observations and theoretical developments. The AFM is a conceptual model that describes the fracture-matrix interaction in the UZ of Yucca Mountain. These validation activities are documented in Section 7 of this report regarding use of an independent line of evidence to provide additional confidence in the use of the AFM in the UZ models. The AFM has been used in UZ flow and transport models under both ambient and thermally disturbed conditions. Developments of these models are documented

  7. CAPTURING UNCERTAINTY IN UNSATURATED-ZONE FLOW USING DIFFERENT CONCEPTUAL MODELS OF FRACTURE-MATRIX INTERACTION

    International Nuclear Information System (INIS)

    SUSAN J. ALTMAN, MICHAEL L. WILSON, GUMUNDUR S. BODVARSSON

    1998-01-01

    Preliminary calculations show that the two different conceptual models of fracture-matrix interaction presented here yield different results pertinent to the performance of the potential repository at Yucca Mountain. Namely, each model produces different ranges of flow in the fractures, where radionuclide transport is thought to be most important. This method of using different flow models to capture both conceptual model and parameter uncertainty ensures that flow fields used in TSPA calculations will be reasonably calibrated to the available data while still capturing this uncertainty. This method also allows for the use of three-dimensional flow fields for the TSPA-VA calculations

  8. Research program to develop and validate conceptual models for flow and transport through unsaturated, fractured rock

    International Nuclear Information System (INIS)

    Glass, R.J.; Tidwell, V.C.

    1991-09-01

    As part of the Yucca Mountain Project, our research program to develop and validate conceptual models for flow and transport through unsaturated fractured rock integrates fundamental physical experimentation with conceptual model formulation and mathematical modeling. Our research is directed toward developing and validating macroscopic, continuum-based models and supporting effective property models because of their widespread utility within the context of this project. Success relative to the development and validation of effective property models is predicted on a firm understanding of the basic physics governing flow through fractured media, specifically in the areas of unsaturated flow and transport in a single fracture and fracture-matrix interaction

  9. Research program to develop and validate conceptual models for flow and transport through unsaturated, fractured rock

    International Nuclear Information System (INIS)

    Glass, R.J.; Tidwell, V.C.

    1991-01-01

    As part of the Yucca Mountain Project, our research program to develop and validate conceptual models for flow and transport through unsaturated fractured rock integrates fundamental physical experimentation with conceptual model formulation and mathematical modeling. Our research is directed toward developing and validating macroscopic, continuum-based models and supporting effective property models because of their widespread utility within the context of this project. Success relative to the development and validation of effective property models is predicated on a firm understanding of the basic physics governing flow through fractured media, specifically in the areas of unsaturated flow and transport in a single fracture and fracture-matrix interaction. 43 refs

  10. Research program to develop and validate conceptual models for flow and transport through unsaturated, fractured rock

    International Nuclear Information System (INIS)

    Glass, R.J.; Tidwell, V.C.

    1991-01-01

    As part of the Yucca Mountain Project, our research program to develop and validate conceptual models for flow and transport through unsaturated fractured rock integrates fundamental physical experimentation with conceptual model formulation and mathematical modeling. Our research is directed toward developing and validating macroscopic, continuum-based models and supporting effective property models because of their widespread utility within the context of this project. Success relative to the development and validation of effective property models is predicted on a firm understanding of the basic physics governing flow through fractured media, specifically in the areas of unsaturated flow and transport in a single fracture and fracture-matrix interaction

  11. Alternative conceptual models and codes for unsaturated flow in fractured tuff: Preliminary assessments for GWTT-95

    International Nuclear Information System (INIS)

    Ho, C.K.; Altman, S.J.; Arnold, B.W.

    1995-09-01

    Groundwater travel time (GWTT) calculations will play an important role in addressing site-suitability criteria for the potential high-level nuclear waste repository at Yucca Mountain,Nevada. In support of these calculations, Preliminary assessments of the candidate codes and models are presented in this report. A series of benchmark studies have been designed to address important aspects of modeling flow through fractured media representative of flow at Yucca Mountain. Three codes (DUAL, FEHMN, and TOUGH 2) are compared in these benchmark studies. DUAL is a single-phase, isothermal, two-dimensional flow simulator based on the dual mixed finite element method. FEHMN is a nonisothermal, multiphase, multidimensional simulator based primarily on the finite element method. TOUGH2 is anon isothermal, multiphase, multidimensional simulator based on the integral finite difference method. Alternative conceptual models of fracture flow consisting of the equivalent continuum model (ECM) and the dual permeability (DK) model are used in the different codes

  12. Integrated approach to model decomposed flow hydrograph using artificial neural network and conceptual techniques

    Science.gov (United States)

    Jain, Ashu; Srinivasulu, Sanaga

    2006-02-01

    This paper presents the findings of a study aimed at decomposing a flow hydrograph into different segments based on physical concepts in a catchment, and modelling different segments using different technique viz. conceptual and artificial neural networks (ANNs). An integrated modelling framework is proposed capable of modelling infiltration, base flow, evapotranspiration, soil moisture accounting, and certain segments of the decomposed flow hydrograph using conceptual techniques and the complex, non-linear, and dynamic rainfall-runoff process using ANN technique. Specifically, five different multi-layer perceptron (MLP) and two self-organizing map (SOM) models have been developed. The rainfall and streamflow data derived from the Kentucky River catchment were employed to test the proposed methodology and develop all the models. The performance of all the models was evaluated using seven different standard statistical measures. The results obtained in this study indicate that (a) the rainfall-runoff relationship in a large catchment consists of at least three or four different mappings corresponding to different dynamics of the underlying physical processes, (b) an integrated approach that models the different segments of the decomposed flow hydrograph using different techniques is better than a single ANN in modelling the complex, dynamic, non-linear, and fragmented rainfall runoff process, (c) a simple model based on the concept of flow recession is better than an ANN to model the falling limb of a flow hydrograph, and (d) decomposing a flow hydrograph into the different segments corresponding to the different dynamics based on the physical concepts is better than using the soft decomposition employed using SOM.

  13. DEVELOPING AND PROPOSING A CONCEPTUAL MODEL OF THE FLOW EXPERIENCE DURING ONLINE INFORMATION SEARCH

    Directory of Open Access Journals (Sweden)

    Lazoc Alina

    2012-07-01

    Full Text Available Information search is an essential part of the consumer`s decision making process. The online medium offers new opportunities and challenges for information search activities (in and outside the marketing context. We are interested in the way human information experiences and behaviors are affected by this. Very often online games and social web activities are perceived as challenging, engaging and enjoyable, while online information search is far below this evaluation. Our research proposal implies that using the online medium for information search may provoke enjoyable experiences through the flow state, which may in turn positively influence an individual`s exploratory information behavior and encourage his/her pro-active market behavior. The present study sets out to improve the understanding of the online medium`s impact on human`s exploratory behavior. We hypothesize that the inclusion of the online flow experience in our research model will better explain exploratory information search behaviors. A 11-component conceptual framework is proposed to explain the manifestations of flow, its personal and technological determinants and its behavioral consequence in the context of online information search. Our research has the primary purpose to present an integrated online flow model. Its secondary objective is to stimulate extended research in the area of informational behaviors in the digital age. The paper is organized in three sections. In the first section we briefly report the analysis results of the most relevant online flow theory literature and, drawing on it, we are trying to identify variables and relationships among these. In the second part we propose a research model and use prior flow models to specify a range of testable hypothesis. Drawing on the conceptual model developed, the last section of our study presents the final conclusions and proposes further steps in evaluating the model`s validity. Future research directions

  14. Conceptual hydrologic model of flow in the unsaturated zone, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Montazer, P.; Wilson, W.E.

    1984-01-01

    The purpose of this report is to propose a conceptual hydrologic model that reasonably describes the flow of fluids through the unsaturated zone at Yucca Mountain, for use as a basis for preliminary site-performance assessment and as a guide to further investigations. Scott and others (1983) presented an initial conceptual hydrogeologic model for the unsaturated zone at Yucca Mountain, based on detailed geologic, but very limited hydrologic, information. In this report, some of their concepts are examined and either supported or modified, and new concepts are developed. The model describes the manner in which flow probably occurs at Yucca Mountain and is based on: (1) current understanding of the hydrogeologic framework; (2) application of the principles of unsaturated flow; and (3) interpretation of some preliminary data from ongoing field and laboratory investigations. Included are extensive geologic information but relatively few hydrologic data that currently exist from the unsaturated zone in the Yucca Mountain area. Many uncertainties remain to be resolved concerning hydrologic conditions and processes. As a result, most of the concepts presented are intentionally descriptive and conjectural, with little quantitative basis provided. However, for the sake of directness and simplicity of expression, the model is presented as if it were a true expression of the facts. The authors recognize, and the reader should be aware, that the proposed model probably is not the only reasonable description that could be made at this point, and it certainly is subject to revision and quantification as more data become available. Although various alternative models probably could be developed, the one described in this report seems to fit current understanding of the unsaturated flow through a section of layered, fractured-rock formations with contrasting hydrologic properties, such as occurs at Yucca Mountain. 41 refs., 14 figs., 1 tab

  15. Flow structure through pool-riffle sequences and a conceptual model for their sustainability in gravel-bed rivers

    Science.gov (United States)

    D. Caamano; P. Goodwin; J. M. Buffington

    2010-01-01

    Detailed field measurements and simulations of three-dimensional flow structure were used to develop a conceptual model to explain the sustainability of self-formed pool-riffle sequences in gravel-bed rivers. The analysis was conducted at the Red River Wildlife Management Area in Idaho, USA, and enabled characterization of the flow structure through two consecutive...

  16. Conceptual and numerical models of groundwater flow and solute transport in fracture zones: Application to the Aspo Island (Sweden)

    International Nuclear Information System (INIS)

    Molinero, J.; Samper, J.

    2003-01-01

    Several countries around the world are considering the final disposal of high-level radioactive waste in deep repositories located in fractured granite formations. Evaluating the long term safety of such repositories requires sound conceptual and numerical models which must consider simultaneously groundwater flow, solute transport and chemical and radiological processes. These models are being developed from data and knowledge gained from in situ experiments carried out at deep underground laboratories such as that of Aspo, Sweden, constructed in fractured granite. The Redox Zone Experiment is one of such experiments performed at Aspo in order to evaluate the effects of the construction of the access tunnel on the hydrogeological and hydrochemical conditions of a fracture zone intersected by the tunnel. Previous authors interpreted hydrochemical and isotopic data of this experiment using a mass-balance approach based on a qualitative description of groundwater flow conditions. Such an interpretation, however, is subject to uncertainties related to an over-simplified conceptualization of groundwater flow. Here we present numerical models of groundwater flow and solute transport for this fracture zone. The first model is based on previously published conceptual model. It presents noticeable un consistencies and fails to match simultaneously observed draw downs and chloride breakthrough curves. To overcome its limitations, a revised flow and transport model is presented which relies directly on available hydrodynamic and transport parameters, is based on the identification of appropriate flow and transport boundary conditions and uses, when needed, solute data extrapolated from nearby fracture zones. A significant quantitative improvement is achieved with the revised model because its results match simultaneously drawdown and chloride data. Other improvements are qualitative and include: ensuring consistency of hydrodynamic and hydrochemical data and avoiding

  17. BUILDING CONCEPTUAL AND MATHEMATICAL MODEL FOR WATER FLOW AND SOLUTE TRANSPORT IN THE UNSATURATED ZONE AT KOSNICA SITE

    Directory of Open Access Journals (Sweden)

    Stanko Ružičić

    2012-12-01

    Full Text Available Conceptual model of flow and solute transport in unsaturated zone at Kosnica site, which is the basis for modeling pollution migration through the unsaturated zone to groundwater, is set up. The main characteristics of the unsaturated zone of the Kosnica site are described. Detailed description of investigated profile of unsaturated zone, with all necessary analytical results performed and used in building of conceptual models, is presented. Experiments that are in progress and processes which are modeled are stated. Monitoring of parameters necessary for calibration of models is presented. The ultimate goal of research is risk assessment of groundwater contamination at Kosnica site that has its source in or on unsaturated zone.

  18. Groundwater Flow and Thermal Modeling to Support a Preferred Conceptual Model for the Large Hydraulic Gradient North of Yucca Mountain

    International Nuclear Information System (INIS)

    McGraw, D.; Oberlander, P.

    2007-01-01

    The purpose of this study is to report on the results of a preliminary modeling framework to investigate the causes of the large hydraulic gradient north of Yucca Mountain. This study builds on the Saturated Zone Site-Scale Flow and Transport Model (referenced herein as the Site-scale model (Zyvoloski, 2004a)), which is a three-dimensional saturated zone model of the Yucca Mountain area. Groundwater flow was simulated under natural conditions. The model framework and grid design describe the geologic layering and the calibration parameters describe the hydrogeology. The Site-scale model is calibrated to hydraulic heads, fluid temperature, and groundwater flowpaths. One area of interest in the Site-scale model represents the large hydraulic gradient north of Yucca Mountain. Nearby water levels suggest over 200 meters of hydraulic head difference in less than 1,000 meters horizontal distance. Given the geologic conceptual models defined by various hydrogeologic reports (Faunt, 2000, 2001; Zyvoloski, 2004b), no definitive explanation has been found for the cause of the large hydraulic gradient. Luckey et al. (1996) presents several possible explanations for the large hydraulic gradient as provided below: The gradient is simply the result of flow through the upper volcanic confining unit, which is nearly 300 meters thick near the large gradient. The gradient represents a semi-perched system in which flow in the upper and lower aquifers is predominantly horizontal, whereas flow in the upper confining unit would be predominantly vertical. The gradient represents a drain down a buried fault from the volcanic aquifers to the lower Carbonate Aquifer. The gradient represents a spillway in which a fault marks the effective northern limit of the lower volcanic aquifer. The large gradient results from the presence at depth of the Eleana Formation, a part of the Paleozoic upper confining unit, which overlies the lower Carbonate Aquifer in much of the Death Valley region. The

  19. A conceptual model for groundwater flow and geochemical evolution in the southern Outaouais Region, Québec, Canada

    International Nuclear Information System (INIS)

    Montcoudiol, N.; Molson, J.; Lemieux, J.-M.; Cloutier, V.

    2015-01-01

    Highlights: • Geochemical and isotope data help constrain the 2D conceptual flow model. • Stable isotopes indicate recharge occurring under conditions similar to current climate. • Mixing was found between younger ( 3 H) and older ( 14 C and 4 He) groundwater. • Mixing occurred under natural flow conditions and/or was induced during sampling. • The new conceptual model shows dominant local and intermediate flow systems. - Abstract: A conceptual model was developed for a hydrogeological flow system in the southern Outaouais Region, Quebec, Canada, where the local population relies heavily on groundwater pumped from shallow overburden aquifers and from deeper fractured crystalline bedrock. The model is based on the interpretation of aqueous inorganic geochemical data from 14 wells along a cross-section following the general flow direction, of which 9 were also analysed for isotopes (δ 18 O, δ 2 H, 3 H, δ 13 C, 14 C) and 4 for noble gases (He, Ne, Ar, Xe, Kr). Three major water types were identified: (1) Ca–HCO 3 in the unconfined aquifer as a result of silicate (Ca-feldspar) weathering, (2) Na–Cl as a remnant of the post-glacial Champlain Sea in stagnant confined zones of the aquifer, and (3) Na–HCO 3 , resulting from freshening of the confined aquifer due to Ca–Na cation exchange. Chemical data also allowed the identification of significant mixing zones. Isotope and noble gas data confirm the hypothesis of remnant water from the Champlain Sea and also support the hypothesis of mixing processes between a young tritium-rich component with an older component containing high 4 He concentrations. It is still unclear if the mixing occurs under natural flow conditions or if it is induced by pumping during the sampling, most wells being open boreholes in the bedrock. It is clear, however, that the hydrogeochemical system is dynamic and still evolving from induced changes since the last glaciation. As a next step, the conceptual model will serve as a

  20. Geostatistical and adjoint sensitivity techniques applied to a conceptual model of ground-water flow in the Paradox Basin, Utah

    International Nuclear Information System (INIS)

    Metcalfe, D.E.; Campbell, J.E.; RamaRao, B.S.; Harper, W.V.; Battelle Project Management Div., Columbus, OH)

    1985-01-01

    Sensitivity and uncertainty analysis are important components of performance assessment activities for potential high-level radioactive waste repositories. The application of geostatistical and adjoint sensitivity techniques to aid in the calibration of an existing conceptual model of ground-water flow is demonstrated for the Leadville Limestone in Paradox Basin, Utah. The geostatistical method called kriging is used to statistically analyze the measured potentiometric data for the Leadville. This analysis consists of identifying anomalous data and data trends and characterizing the correlation structure between data points. Adjoint sensitivity analysis is then performed to aid in the calibration of a conceptual model of ground-water flow to the Leadville measured potentiometric data. Sensitivity derivatives of the fit between the modeled Leadville potentiometric surface and the measured potentiometric data to model parameters and boundary conditions are calculated by the adjoint method. These sensitivity derivatives are used to determine which model parameter and boundary condition values should be modified to most efficiently improve the fit of modeled to measured potentiometric conditions

  1. Challenging and improving conceptual models for isothermal flow in unsaturated, fractured rock through exploration of small-scale processes

    International Nuclear Information System (INIS)

    Glass, R.J.; Nicholl, M.J.; Tidwell, V.C.

    1996-01-01

    Over the past several years, the authors have performed experimental studies focused on understanding small-scale flow processes within discrete fractures and individual matrix blocks; much of the understanding gained in that time differs from that underlying the basic assumptions used in effective media representations. Here they synthesize the process level understanding gained from their laboratory studies to explore how such small-scale processes may influence the behavior of fluid flow in fracture networks and ensembles of matrix blocks at levels sufficient to impact the formulation of intermediate-scale effective media properties. They also explore, by means of a thought experiment, how these same small-scale processes could couple to produce a large-scale system response inconsistent with current conceptual models based on continuum representations of flow through unsaturated, fractured rock. Based on their findings, a number of modifications to existing dual permeability models are suggested that should allow them improved applicability; however, even with these modifications, it is likely that continuum representations of flow through unsaturated fractured rock will have limited validity and must therefore be applied with caution

  2. Conceptual models of information processing

    Science.gov (United States)

    Stewart, L. J.

    1983-01-01

    The conceptual information processing issues are examined. Human information processing is defined as an active cognitive process that is analogous to a system. It is the flow and transformation of information within a human. The human is viewed as an active information seeker who is constantly receiving, processing, and acting upon the surrounding environmental stimuli. Human information processing models are conceptual representations of cognitive behaviors. Models of information processing are useful in representing the different theoretical positions and in attempting to define the limits and capabilities of human memory. It is concluded that an understanding of conceptual human information processing models and their applications to systems design leads to a better human factors approach.

  3. Using a conceptual model to assess the role of flow regulation in the hydromorphological evolution of riparian corridors

    Science.gov (United States)

    Martínez-Fernández, Vanesa; Gonzalez del Tánago, Marta; García de Jalón, diego

    2017-04-01

    Riparian corridors result from active vegetation-fluvial interactions, which are highly dependent on flow regime conditions and sediment dynamics. Colonization, establishment and survival of species are constrained by fluvial processes which vary according to topographic and sedimentological complexity of the corridor. In order to manage these dynamic and complex riparian systems there is a need for practical tools based on conceptual models. The objective of this study was to apply the conceptual model of riparian corridors lateral zonation in response to the dominant fluvial processes established by Gurnell et al. (2015) and verify its usefulness as a tool for assessing the effect of flow regulation. Two gravel rivers have been selected for this purpose from the north of Spain, the Porma River regulated by Boñar large dam and the unregulated Curueño River. The historical series of flows and the aerial photographs of 1956 and 2011 on which the river corridor has been delimited have been analyzed and identified the permanent inundated zone (1) and four areas of riparian vegetation dominated respectively by fluvial disturbance with coarse sediment erosion and deposition (zone 2), fluvial disturbance with finer sediment deposition (zone 3), inundation (zone 4) and soil moisture regime (zone 5). Likewise, a two-dimensional hydraulic simulation was performed with avenues of different return periods and calculated the prevailing hydraulic conditions (depths, velocities and drag forces) to characterize each of the vegetation zones mentioned in both rivers. The results show that the most active zone 2 (fluvial disturbance dominated showing coarse sediment erosion and deposition) disappears due to the regulation of flows and vegetation encroachment, while the riparian corridor is dominated by the less active zone where the vegetation is maintained by the humidity of sporadic floods and underground runoff. Moreover, by means of the hydraulic simulation we have found a

  4. Conceptual IT model

    Science.gov (United States)

    Arnaoudova, Kristina; Stanchev, Peter

    2015-11-01

    The business processes are the key asset for every organization. The design of the business process models is the foremost concern and target among an organization's functions. Business processes and their proper management are intensely dependent on the performance of software applications and technology solutions. The paper is attempt for definition of new Conceptual model of IT service provider, it could be examined as IT focused Enterprise model, part of Enterprise Architecture (EA) school.

  5. Chaotic-Dynamical Conceptual Model to Describe Fluid Flow and Contaminant Transport in a Fractured Vadose Zone

    International Nuclear Information System (INIS)

    Faybishenko, Boris; Doughty, Christine; Geller, Jil T.

    1999-01-01

    DOE faces the remediation of numerous contaminated sites, such as those at Hanford, INEEL, LLNL, and LBNL, where organic and/or radioactive wastes were intentionally or accidentally released to the vadose zone from surface spills, underground tanks, cribs, shallow ponds, and deep wells. Migration of these contaminants through the vadose zone has led to the contamination of (or threatens to contaminate) underlying groundwater. A key issue in choosing a corrective action plan to clean up contaminated sites is the determination of the location, total mass, mobility and travel time to receptors for contaminants moving in the vadose zone. These problems are difficult to solve in a technically defensible and accurate manner because contaminants travel downward intermittently, through narrow pathways, driven by variations in environmental conditions. These preferential flow pathways can be difficult to find and predict. The primary objective of this project is to determine if and when dynamical chaos theory can be used to investigate infiltration of fluid and contaminant transport in heterogeneous soils and fractured rocks. The objective of this project is being achieved through the following activities: Development of multi scale conceptual models and mathematical and numerical algorithms for flow and transport, which incorporate both (a) the spatial variability of heterogeneous porous and fractured media and (b) the temporal dynamics of flow and transport; Development of appropriate experimental field and laboratory techniques needed to detect diagnostic parameters for chaotic behavior of flow; Evaluation of chaotic behavior of flow in laboratory and field experiments using methods from non-linear dynamics; Evaluation of the impact these dynamics may have on contaminant transport through heterogeneous fractured rocks and soils and remediation efforts. This approach is based on the consideration of multi scale spatial heterogeneity and flow phenomena that are affected by

  6. Conceptualization of preferential flow for hillslope stability assessment

    Science.gov (United States)

    Kukemilks, Karlis; Wagner, Jean-Frank; Saks, Tomas; Brunner, Philip

    2018-03-01

    This study uses two approaches to conceptualize preferential flow with the goal to investigate their influence on hillslope stability. Synthetic three-dimensional hydrogeological models using dual-permeability and discrete-fracture conceptualization were subsequently integrated into slope stability simulations. The slope stability simulations reveal significant differences in slope stability depending on the preferential flow conceptualization applied, despite similar small-scale hydrogeological responses of the system. This can be explained by a local-scale increase of pore-water pressures observed in the scenario with discrete fractures. The study illustrates the critical importance of correctly conceptualizing preferential flow for slope stability simulations. It further demonstrates that the combination of the latest generation of physically based hydrogeological models with slope stability simulations allows for improvement to current modeling approaches through more complex consideration of preferential flow paths.

  7. CADDIS Volume 2. Sources, Stressors and Responses: Flow Alteration - Detailed Conceptual Diagram

    Science.gov (United States)

    Introduction to the flow alteration module, when to list flow alteration as a candidate cause, ways to measure flow alteration, simple and detailed conceptual model diagrams for flow alteration, flow alteration module references and literature reviews.

  8. CADDIS Volume 2. Sources, Stressors and Responses: Flow Alteration - Simple Conceptual Diagram

    Science.gov (United States)

    Introduction to the flow alteration module, when to list flow alteration as a candidate cause, ways to measure flow alteration, simple and detailed conceptual model diagrams for flow alteration, flow alteration module references and literature reviews.

  9. High flows in the 21st Century: analysis with a simple conceptual hydrological models using the input of 3 GCMs (A2 scenario)

    NARCIS (Netherlands)

    Lanen, H.A.J.; Wanders, N.

    2011-01-01

    The study on high flows with a conceptual hydrological model leads to the following conclusions for about 1500 randomly selected land points across the world that have an intermediate soil water supply capacity and an intermediary responding groundwater system: · the probability distributions of

  10. Conceptualizing Group Flow: A Framework

    Science.gov (United States)

    Duncan, Jana; West, Richard E.

    2018-01-01

    This literature review discusses the similarities in main themes between Csikszentmihályi theory of individual flow and Sawyer theory of group flow, and compares Sawyer's theory with existing concepts in the literature on group work both in education and business. Because much creativity and innovation occurs within groups, understanding group…

  11. Laboratory research program to aid in developing and testing the validity of conceptual models for flow and transport through unsaturated porous media

    International Nuclear Information System (INIS)

    Glass, R.J.

    1991-01-01

    As part of the Yucca Mountain Project, a laboratory research program is being developed at Sandia National Laboratories that will integrate fundamental physical experimentation with conceptual model formulation and mathematical modeling and aid in subsequent model validation for unsaturated zone water and contaminant transport. Experimental systems are being developed to explore flow and transport processes and assumptions of fundamental importance to various conceptual models. Experimentation will run concurrently in two types of systems: fractured and nonfractured tuffaceous systems; and analogue systems having specific characteristics of the tuff systems but designed to maximize experimental control and resolution of data measurement. Areas in which experimentation currently is directed include infiltration flow instability, water and solute movement in unsaturated fractures, fracture-matrix interaction, and scaling laws to define effective large-scale properties for heterogeneous, fractured media. 16 refs

  12. A comparison of results from groundwater flow modelling for two conceptual hydrogeological models for the Konrad site

    International Nuclear Information System (INIS)

    Arens, G.; Fein, E.; Storck, R.

    1991-01-01

    Radioactive wastes with negligible heat production are planned to be disposed of into a deep iron ore formation at the Konrad site. This repository will be bedded in a low permeable formation called Oxfordian in a depth of 800 - 1300 m below the surface. The host formation is largely covered with clay of a few hundred meters thickness. The hydrogeological model area has an extension of 14 km in the west-east and 47 km in the north-south direction. The geological formations within the model area are disturbed by several fractured zones with a vertical extension of several hundred meters intersecting different horizontal layers. Due to this fact two hydrogeological models have been developed: The first one handles the fractured zones by globally increased permeabilities of the geological formations. The second handles the fractured zones by locally increased permeabilities, leaving the permeabilities of undisturbed areas unchanged. For both models, groundwater flow calculations have been carried out including parameter variations of permeability values. The results of the calculations are presented as flow paths which are compared for both models. Computer code used: SWIFT. 1 fig., 3 tabs., 3 refs

  13. Laboratory research program to aid in developing and testing the validity of conceptual models for flow and transport through unsaturated porous media

    International Nuclear Information System (INIS)

    Glass, R.J.

    1990-01-01

    As part of the Yucca Mountain Project, a laboratory research program is being developed at Sandia National Laboratories that will integrate fundamental physical experimentation with conceptual formulation and mathematical modeling and aid in subsequent model validation for unsaturated zone water and contaminant transport. Experimental systems are being developed to explore flow and transport processes and assumptions of fundamental importance to various conceptual models. Experimentation will run concurrently in two types of systems: fractured and nonfractured tuffaceous systems; and analogue systems having specific characteristics of the tuff systems but designed to maximize experimental control and resolution of data measurement. Questions to which experimentation currently is directed include infiltration flow instability, water and solute movement in unsaturated fractures, fracture-matrix interaction, and the definition of effective large-scale properties for heterogeneous, fractured media. 16 refs

  14. Conceptual model of fractured aquifer of Uranium Deposit in Caetité, Bahia: implications for groundwater flow

    International Nuclear Information System (INIS)

    Silva, Liliane Ferreira da

    2015-01-01

    The studied area is represented by the uraniferous district of Lagoa Real, located in the center-south of Bahia State, Brazil. The region is set in a semiarid climate context, with hot and dry weather parameters, with hydric deficit along all months of the year and high aridity index. Rural population is affected on drought periods since small agriculture and animal rearing are the main economic activities which are vulnerable in dry seasons. Groundwater represents the main supply source considering that most surface water sources are temporary and only exhibit flow in rainy periods. The main aquifer system present on the region is fractured, and the presence of groundwater flow occurs through the discontinuities of the rock considering that the rock mass corresponds to the set formed by the rock matrix and all its discontinuities (fractures, foliations, discordance, etc). In this sense, the main purpose of this Master Dissertation was to develop a conceptual model for the aquifer system, through the geotechnical characterization of discontinuities, once these structures allow the secondary porosity of the medium. Hydrochemical data hand out as complement for physical characterization for the behavioral interpretation of the aquifer. The aquifer system is unconfined, however, presents points of stagnation of flow forming compartments without communication with the surrounding areas. According to the International Society of Rock Mechanics ISRM method, which consist on qualitative and quantitative characterization of discontinuities of rock mass scanlines were constructed, systematically, describing, the following structure parameters: attitude, spacing, persistence, openness, infilling and roughness. From the results analysis it could be concluded that the aquifer system is composed of three discontinuities sets: one set which dips to NE, second set dipping to SW-W-NW and the last set sub-horizontal. The first and second sets are responsible for the aquifer

  15. Event-Based Conceptual Modeling

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    2009-01-01

    The purpose of the paper is to obtain insight into and provide practical advice for event-based conceptual modeling. We analyze a set of event concepts and use the results to formulate a conceptual event model that is used to identify guidelines for creation of dynamic process models and static...... information models. We characterize events as short-duration processes that have participants, consequences, and properties, and that may be modeled in terms of information structures. The conceptual event model is used to characterize a variety of event concepts and it is used to illustrate how events can...... be used to integrate dynamic modeling of processes and static modeling of information structures. The results are unique in the sense that no other general event concept has been used to unify a similar broad variety of seemingly incompatible event concepts. The general event concept can be used...

  16. Chance-constrained overland flow modeling for improving conceptual distributed hydrologic simulations based on scaling representation of sub-daily rainfall variability

    International Nuclear Information System (INIS)

    Han, Jing-Cheng; Huang, Guohe; Huang, Yuefei; Zhang, Hua; Li, Zhong; Chen, Qiuwen

    2015-01-01

    Lack of hydrologic process representation at the short time-scale would lead to inadequate simulations in distributed hydrological modeling. Especially for complex mountainous watersheds, surface runoff simulations are significantly affected by the overland flow generation, which is closely related to the rainfall characteristics at a sub-time step. In this paper, the sub-daily variability of rainfall intensity was considered using a probability distribution, and a chance-constrained overland flow modeling approach was proposed to capture the generation of overland flow within conceptual distributed hydrologic simulations. The integrated modeling procedures were further demonstrated through a watershed of China Three Gorges Reservoir area, leading to an improved SLURP-TGR hydrologic model based on SLURP. Combined with rainfall thresholds determined to distinguish various magnitudes of daily rainfall totals, three levels of significance were simultaneously employed to examine the hydrologic-response simulation. Results showed that SLURP-TGR could enhance the model performance, and the deviation of runoff simulations was effectively controlled. However, rainfall thresholds were so crucial for reflecting the scaling effect of rainfall intensity that optimal levels of significance and rainfall threshold were 0.05 and 10 mm, respectively. As for the Xiangxi River watershed, the main runoff contribution came from interflow of the fast store. Although slight differences of overland flow simulations between SLURP and SLURP-TGR were derived, SLURP-TGR was found to help improve the simulation of peak flows, and would improve the overall modeling efficiency through adjusting runoff component simulations. Consequently, the developed modeling approach favors efficient representation of hydrological processes and would be expected to have a potential for wide applications. - Highlights: • We develop an improved hydrologic model considering the scaling effect of rainfall. • A

  17. Chance-constrained overland flow modeling for improving conceptual distributed hydrologic simulations based on scaling representation of sub-daily rainfall variability

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jing-Cheng [State Key Laboratory of Hydroscience & Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084 (China); Huang, Guohe, E-mail: huang@iseis.org [Institute for Energy, Environment and Sustainable Communities, University of Regina, Regina, Saskatchewan S4S 0A2 (Canada); Huang, Yuefei [State Key Laboratory of Hydroscience & Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084 (China); Zhang, Hua [College of Science and Engineering, Texas A& M University — Corpus Christi, Corpus Christi, TX 78412-5797 (United States); Li, Zhong [Institute for Energy, Environment and Sustainable Communities, University of Regina, Regina, Saskatchewan S4S 0A2 (Canada); Chen, Qiuwen [Center for Eco-Environmental Research, Nanjing Hydraulics Research Institute, Nanjing 210029 (China)

    2015-08-15

    Lack of hydrologic process representation at the short time-scale would lead to inadequate simulations in distributed hydrological modeling. Especially for complex mountainous watersheds, surface runoff simulations are significantly affected by the overland flow generation, which is closely related to the rainfall characteristics at a sub-time step. In this paper, the sub-daily variability of rainfall intensity was considered using a probability distribution, and a chance-constrained overland flow modeling approach was proposed to capture the generation of overland flow within conceptual distributed hydrologic simulations. The integrated modeling procedures were further demonstrated through a watershed of China Three Gorges Reservoir area, leading to an improved SLURP-TGR hydrologic model based on SLURP. Combined with rainfall thresholds determined to distinguish various magnitudes of daily rainfall totals, three levels of significance were simultaneously employed to examine the hydrologic-response simulation. Results showed that SLURP-TGR could enhance the model performance, and the deviation of runoff simulations was effectively controlled. However, rainfall thresholds were so crucial for reflecting the scaling effect of rainfall intensity that optimal levels of significance and rainfall threshold were 0.05 and 10 mm, respectively. As for the Xiangxi River watershed, the main runoff contribution came from interflow of the fast store. Although slight differences of overland flow simulations between SLURP and SLURP-TGR were derived, SLURP-TGR was found to help improve the simulation of peak flows, and would improve the overall modeling efficiency through adjusting runoff component simulations. Consequently, the developed modeling approach favors efficient representation of hydrological processes and would be expected to have a potential for wide applications. - Highlights: • We develop an improved hydrologic model considering the scaling effect of rainfall. • A

  18. A conceptual hydrogeologic model for the hydrogeologic framework, geochemistry, and groundwater-flow system of the Edwards-Trinity and related aquifers in the Pecos County region, Texas

    Science.gov (United States)

    Thomas, Jonathan V.; Stanton, Gregory P.; Bumgarner, Johnathan R.; Pearson, Daniel K.; Teeple, Andrew; Houston, Natalie A.; Payne, Jason; Musgrove, MaryLynn

    2013-01-01

    The Edwards-Trinity aquifer is a vital groundwater resource for agricultural, industrial, and municipal uses in the Trans-Pecos region of west Texas. A conceptual model of the hydrogeologic framework, geochemistry, and groundwater-flow system in the 4,700 square-mile study area was developed by the U.S. Geological Survey (USGS) in cooperation with the Middle Pecos Groundwater Conservation District, Pecos County, City of Fort Stockton, Brewster County, and Pecos County Water Control and Improvement District No. 1. The model was developed to gain a better understanding of the groundwater system and to establish a scientific foundation for resource-management decisions. Data and information were collected or obtained from various sources to develop the model. Lithologic information obtained from well reports and geophysical data were used to describe the hydrostratigraphy and structural features of the groundwater system, and aquifer-test data were used to estimate aquifer hydraulic properties. Groundwater-quality data were used to evaluate groundwater-flow paths, water and rock interaction, aquifer interaction, and the mixing of water from different sources. Groundwater-level data also were used to evaluate aquifer interaction as well as to develop a potentiometric-surface map, delineate regional groundwater divides, and describe regional groundwater-flow paths.

  19. Process generalization in conceptual models

    NARCIS (Netherlands)

    Wieringa, Roelf J.

    In conceptual modeling, the universe of discourse (UoD) is divided into classes which have a taxonomic structure. The classes are usually defined in terms of attributes (all objects in a class share attribute names) and possibly of events. For enmple, the class of employees is the set of objects to

  20. A conceptual model of flow to the Waikoropupu Springs, NW Nelson, New Zealand, based on hydrometric and tracer (18O, Cl,3H and CFC evidence

    Directory of Open Access Journals (Sweden)

    J. T. Thomas

    2008-01-01

    Full Text Available The Waikoropupu Springs, a large karst resurgence 4 km from the coast, are supplied by the Arthur Marble Aquifer (AMA underlying the Takaka Valley, South Island, New Zealand. New evidence on the recharge sources in the catchment, combined with previous results, is used to establish a new recharge model for the AMA. Combined with the oxygen-18 mass balance, this yields a quantitative description of the inputs and outputs to the aquifer. It shows that the Main Spring is sourced mainly from the karst uplands (74%, with smaller contributions from the Upper Takaka River (18% and valley rainfall (8%, while Fish Creek Spring contains mostly Upper Takaka River water (50%. In addition, much of the Upper Takaka River contribution to the aquifer (58% bypasses the springs and is discharged offshore via submarine springs. The chemical concentrations of the Main Spring show input of 0.5% of sea water on average, which varies with flow and derives from the deep aquifer. Tritium measurements spanning 40 yr, and CFC-11 measurements, give a mean residence time of 8 yr for the Main Spring water using the preferred two-component model. Our conceptual flow model, based on the flow, chloride, oxygen-18 and age measurements, invokes two different flow systems with different recharge sources to explain the flow within the AMA. One system contains deeply penetrating old water with mean age 10.2 yr and water volume 3 km3, recharged from the karst uplands. The other, at shallow levels below the valley floor, has much younger water with mean age 1.2 yr and water volume 0.4 km3, recharged by Upper Takaka River and valley rainfall. The flow systems contribute in different proportions to the Main Spring, Fish Creek Springs and offshore springs. Their very different behaviours, despite being in the same aquifer, are attributed to the presence of a diorite intrusion below the surface of the lower valley, which diverts the deep flow towards the Waikoropupu Springs and allows

  1. Revised conceptualization of the North China Basin groundwater flow system: Groundwater age, heat and flow simulations

    Science.gov (United States)

    Cao, Guoliang; Han, Dongmei; Currell, Matthew J.; Zheng, Chunmiao

    2016-09-01

    Groundwater flow in deep sedimentary basins results from complex evolution processes on geological timescales. Groundwater flow systems conceptualized according to topography and/or groundwater table configuration generally assume a near-equilibrium state with the modern landscape. However, the time to reach such a steady state, and more generally the timescales of groundwater flow system evolution are key considerations for large sedimentary basins. This is true in the North China Basin (NCB), which has been studied for many years due to its importance as a groundwater supply. Despite many years of study, there remain contradictions between the generally accepted conceptual model of regional flow, and environmental tracer data. We seek to reconcile these contractions by conducting simulations of groundwater flow, age and heat transport in a three dimensional model, using an alternative conceptual model, based on geological, thermal, isotope and historical data. We infer flow patterns under modern hydraulic conditions using this new model and present the theoretical maximum groundwater ages under such a flow regime. The model results show that in contrast to previously accepted conceptualizations, most groundwater is discharged in the vicinity of the break-in-slope of topography at the boundary between the piedmont and central plain. Groundwater discharge to the ocean is in contrast small, and in general there are low rates of active flow in the eastern parts of the basin below the central and coastal plain. This conceptualization is more compatible with geochemical and geothermal data than the previous model. Simulated maximum groundwater ages of ∼1 Myrs below the central and coastal plain indicate that residual groundwater may be retained in the deep parts of the basin since being recharged during the last glacial period or earlier. The groundwater flow system has therefore probably not reached a new equilibrium state with modern-day hydraulic conditions. The

  2. Conceptual and numerical models of groundwater flow in the Ogallala aquifer in Gregory and Tripp Counties, South Dakota, water years 1985--2009

    Science.gov (United States)

    Davis, Kyle W.; Putnam, Larry D.

    2013-01-01

    The Ogallala aquifer is an important water resource for the Rosebud Sioux Tribe in Gregory and Tripp Counties in south-central South Dakota and is used for irrigation, public supply, domestic, and stock water supplies. To better understand groundwater flow in the Ogallala aquifer, conceptual and numerical models of groundwater flow were developed for the aquifer. A conceptual model of the Ogallala aquifer was used to analyze groundwater flow and develop a numerical model to simulate groundwater flow in the aquifer. The MODFLOW–NWT model was used to simulate transient groundwater conditions for water years 1985–2009. The model was calibrated using statistical parameter estimation techniques. Potential future scenarios were simulated using the input parameters from the calibrated model for simulations of potential future drought and future increased pumping. Transient simulations were completed with the numerical model. A 200-year transient initialization period was used to establish starting conditions for the subsequent 25-year simulation of water years 1985–2009. The 25-year simulation was discretized into three seasonal stress periods per year and used to simulate transient conditions. A single-layer model was used to simulate flow and mass balance in the Ogallala aquifer with a grid of 133 rows and 282 columns and a uniform spacing of 500 meters (1,640 feet). Regional inflow and outflow were simulated along the western and southern boundaries using specified-head cells. All other boundaries were simulated using no-flow cells. Recharge to the aquifer occurs through precipitation on the outcrop area. Model calibration was accomplished using the Parameter Estimation (PEST) program that adjusted individual model input parameters and assessed the difference between estimated and model-simulated values of hydraulic head and base flow. This program was designed to estimate parameter values that are statistically the most likely set of values to result in the

  3. ADOxx Modelling Method Conceptualization Environment

    Directory of Open Access Journals (Sweden)

    Nesat Efendioglu

    2017-04-01

    Full Text Available The importance of Modelling Methods Engineering is equally rising with the importance of domain specific languages (DSL and individual modelling approaches. In order to capture the relevant semantic primitives for a particular domain, it is necessary to involve both, (a domain experts, who identify relevant concepts as well as (b method engineers who compose a valid and applicable modelling approach. This process consists of a conceptual design of formal or semi-formal of modelling method as well as a reliable, migratable, maintainable and user friendly software development of the resulting modelling tool. Modelling Method Engineering cycle is often under-estimated as both the conceptual architecture requires formal verification and the tool implementation requires practical usability, hence we propose a guideline and corresponding tools to support actors with different background along this complex engineering process. Based on practical experience in business, more than twenty research projects within the EU frame programmes and a number of bilateral research initiatives, this paper introduces the phases, corresponding a toolbox and lessons learned with the aim to support the engineering of a modelling method. ”The proposed approach is illustrated and validated within use cases from three different EU-funded research projects in the fields of (1 Industry 4.0, (2 e-learning and (3 cloud computing. The paper discusses the approach, the evaluation results and derived outlooks.

  4. A conceptual model of political market orientation

    DEFF Research Database (Denmark)

    Ormrod, Robert P.

    2005-01-01

    . The remaining four constructs are attitudinal, designed to capture the awareness of members to the activities and importance of stakeholder groups in society, both internal and external to the organisation. The model not only allows the level of a party's political market orientation to be assessed, but also......This article proposes eight constructs of a conceptual model of political market orientation, taking inspiration from the business and political marketing literature. Four of the constructs are 'behavioural' in that they aim to describe the process of how information flows through the organisation...

  5. Chaotic-dynamical conceptual model to describe fluid flow and contaminant transport in a fractured vadose zone. 1998 annual progress report

    International Nuclear Information System (INIS)

    Doughty, C.; Dragila, M.I.; Faybishenko, B.; Podgorney, R.K.; Stoops, T.M.; Wheatcraft, S.W.; Wood, T.R.

    1998-01-01

    'DOE faces the remediation of numerous contaminated sites, such as those at Hanford, INEEL, LLNL, and LBNL, where organic and/or radioactive wastes were intentionally or accidentally released to the vadose zone from surface spills, underground tanks, cribs, shallow ponds, and deep wells. Migration of these contaminants through the vadose zone has lead to the contamination of or threatens to contaminate underlying groundwater. A key issue in choosing a corrective action plan to clean up contaminated sites is to determine the location, total mass, mobility and travel time to receptors for contaminants moving in the vadose zone. These problems are difficult to solve in a technically defensible and accurate manner because contaminants travel downward intermittently through narrow pathways driven by variations in environmental conditions. These preferential pathways can be difficult to find and predict. The primary objective of this project is to determine if and when dynamical chaos theory can be used to investigate infiltration of fluid and contaminant transport in heterogeneous soils and fractured rocks. The objective of this project is being achieved through the following Activities (1) Evaluation of chaotic behavior of flow in laboratory and field experiments using methods from non-linear dynamics; (2) Evaluation of the impact these dynamics may have on contaminant transport through heterogeneous fractured rocks and soils, and how it can be used to guide remediation efforts; (3) Development of a conceptual model and mathematical and numerical algorithms for flow and transport, which incorporate both: (a) the spatial variability of heterogeneous porous and fractured media, and (b) the description of the temporal dynamics of flow and transport, which may be chaotic; and (4) Development of appropriate experimental field and laboratory techniques needed to detect diagnostic parameters for chaotic behavior of flow. This approach is based on the assumption that spatial

  6. A conceptual model of the hydrogeologic framework, geochemistry, and groundwater-flow system of the Edwards-Trinity and related aquifers in the Pecos County region, Texas

    Science.gov (United States)

    Bumgarner, Johnathan R.; Stanton, Gregory P.; Teeple, Andrew; Thomas, Jonathan V.; Houston, Natalie A.; Payne, Jason; Musgrove, MaryLynn

    2012-01-01

    A conceptual model of the hydrogeologic framework, geochemistry, and groundwater-flow system of the Edwards-Trinity and related aquifers, which include the Pecos Valley, Igneous, Dockum, Rustler, and Capitan Reef aquifers, was developed as the second phase of a groundwater availability study in the Pecos County region in west Texas. The first phase of the study was to collect and compile groundwater, surface-water, water-quality, geophysical, and geologic data in the area. The third phase of the study involves a numerical groundwater-flow model of the Edwards-Trinity aquifer in order to simulate groundwater conditions based on various groundwater-withdrawal scenarios. Resource managers plan to use the results of the study to establish management strategies for the groundwater system. The hydrogeologic framework is composed of the hydrostratigraphy, structural features, and hydraulic properties of the groundwater system. Well and geophysical logs were interpreted to define the top and base surfaces of the Edwards-Trinity aquifer units. Elevations of the top and base of the Edwards-Trinity aquifer generally decrease from the southwestern part of the study area to the northeast. The thicknesses of the Edwards-Trinity aquifer units were calculated using the interpolated top and base surfaces of the hydrostratigraphic units. Some of the thinnest sections of the aquifer were in the eastern part of the study area and some of the thickest sections were in the Pecos, Monument Draw, and Belding-Coyanosa trough areas. Normal-fault zones, which formed as growth and collapse features as sediments were deposited along the margins of more resistant rocks and as overlying sediments collapsed into the voids created by the dissolution of Permian-age evaporite deposits, were delineated based on the interpretation of hydrostratigraphic cross sections. The lowest aquifer transmissivity values were measured in the eastern part of the study area; the highest transmissivity values were

  7. Conceptual and numerical models of groundwater flow and solute transport in fracture zones: Application to the Aspo Island (Sweden); Modelos conceptuales y numericos de flujo y transporte de solutos en zonas de fractura: aplicacion a la isla de Aspo (Suecia)

    Energy Technology Data Exchange (ETDEWEB)

    Molinero, J.; Samper, J.

    2003-07-01

    Several countries around the world are considering the final disposal of high-level radioactive waste in deep repositories located in fractured granite formations. Evaluating the long term safety of such repositories requires sound conceptual and numerical models which must consider simultaneously groundwater flow, solute transport and chemical and radiological processes. These models are being developed from data and knowledge gained from in situ experiments carried out at deep underground laboratories such as that of Aspo, Sweden, constructed in fractured granite. The Redox Zone Experiment is one of such experiments performed at Aspo in order to evaluate the effects of the construction of the access tunnel on the hydrogeological and hydrochemical conditions of a fracture zone intersected by the tunnel. Previous authors interpreted hydrochemical and isotopic data of this experiment using a mass-balance approach based on a qualitative description of groundwater flow conditions. Such an interpretation, however, is subject to uncertainties related to an over-simplified conceptualization of groundwater flow. Here we present numerical models of groundwater flow and solute transport for this fracture zone. The first model is based on previously published conceptual model. It presents noticeable un consistencies and fails to match simultaneously observed draw downs and chloride breakthrough curves. To overcome its limitations, a revised flow and transport model is presented which relies directly on available hydrodynamic and transport parameters, is based on the identification of appropriate flow and transport boundary conditions and uses, when needed, solute data extrapolated from nearby fracture zones. A significant quantitative improvement is achieved with the revised model because its results match simultaneously drawdown and chloride data. Other improvements are qualitative and include: ensuring consistency of hydrodynamic and hydrochemical data and avoiding

  8. Supra regional ground water modelling - in-depth analysis of the groundwater flow patterns in eastern Smaaland. Comparison with different conceptual descriptions; Storregional grundvattenmodellering - foerdjupad analys av floedesfoerhaallanden i oestra Smaaland. Jaemfoerelse av olika konceptuella beskrivningar

    Energy Technology Data Exchange (ETDEWEB)

    Ericsson, Lars O. [Lars O Ericsson Consulting AB, Stockholm (Sweden); Holmen, Johan [Golder Associates, Uppsala (Sweden); Rhen, Ingvar; Blomquist, Niklas [SWECO VIAK, Stockholm (Sweden)

    2006-05-15

    One of many geoscientific questions in connection with the siting of a final repository for spent nuclear fuel in Sweden has to do with understanding the large-scale flow patterns of the naturally circulating groundwater. The recharge and discharge of the groundwater is therefore a subject for both SKB's research activities and the interest of the regulatory authorities. This report aims at providing an in-depth scientific analysis of the groundwater flow pattern based on the criteria and suitability indicators which SKB has previously presented with respect to recharge and discharge aspects in a supra regional perspective. The analysis was conducted within the framework of a project whose goals were to: evaluate conceptual simplifications and model uncertainties in supra regional groundwater modelling, and to carry out an in-depth and comprehensive analysis of regional flow conditions in eastern Smaaland. Achieving these goals has required an approach based on the use of available geoscientific data on the Smaaland region combined with an analysis of different conceptual assumptions and system descriptions. The following general conclusions can be drawn from the study and the applied methodology: The factor of greatest importance for the regional flow pattern (from repository depth) is the topography. The discharge areas are mainly found in the low-lying parts of the topography, along valleys, and the recharge areas occur on the heights. The topographic undulation is of greater importance than the properties of the conductivity field. Different lithological units, regional deformation zones, local heterogeneity, Quaternary deposits etc are of less importance than the undulation of the topography. For areas described and analyzed with the most realistic assumptions, the groundwater flow pattern can be described as a primarily local flow process. The median flow path length in the study is on the order of 2 km, and the fraction of supra regional flow paths

  9. UZ Flow Models and Submodels

    International Nuclear Information System (INIS)

    Dixon, P.

    2004-01-01

    The purpose of this Model Report is to document the unsaturated zone (UZ) fluid flow and tracer transport models and submodels as well as the flow fields generated utilizing the UZ Flow and Transport Model of Yucca Mountain (UZ Model), Nevada. This work was planned in ''Technical Work Plan (TWP) for: Performance Assessment Unsaturated Zone'' (BSC 2002 [160819], Section 1.10, Work Package AUZM06). The UZ Model has revised, updated, and enhanced the previous UZ Flow Model REV 00 ICN 01 (BSC 2001 [158726]) by incorporation of the conceptual repository design with new grids, recalibration of property sets, and more comprehensive validation effort. The flow fields describe fracture-fracture, matrix-matrix, and fracture-matrix liquid flow rates and their spatial distributions as well as moisture conditions in the UZ system. These 3-D UZ flow fields are used directly by Performance Assessment (PA). The model and submodels evaluate important hydrogeologic processes in the UZ as well as geochemistry and geothermal conditions. These provide the necessary framework to test conceptual hypotheses of flow and transport at different scales and predict flow and transport behavior under a variety of climatic conditions. In addition, this Model Report supports several PA activities, including abstractions, particle-tracking transport simulations, and the UZ Radionuclide Transport Model

  10. UZ Flow Models and Submodels

    Energy Technology Data Exchange (ETDEWEB)

    P. Dixon

    2004-02-11

    The purpose of this Model Report is to document the unsaturated zone (UZ) fluid flow and tracer transport models and submodels as well as the flow fields generated utilizing the UZ Flow and Transport Model of Yucca Mountain (UZ Model), Nevada. This work was planned in ''Technical Work Plan (TWP) for: Performance Assessment Unsaturated Zone'' (BSC 2002 [160819], Section 1.10, Work Package AUZM06). The UZ Model has revised, updated, and enhanced the previous UZ Flow Model REV 00 ICN 01 (BSC 2001 [158726]) by incorporation of the conceptual repository design with new grids, recalibration of property sets, and more comprehensive validation effort. The flow fields describe fracture-fracture, matrix-matrix, and fracture-matrix liquid flow rates and their spatial distributions as well as moisture conditions in the UZ system. These 3-D UZ flow fields are used directly by Performance Assessment (PA). The model and submodels evaluate important hydrogeologic processes in the UZ as well as geochemistry and geothermal conditions. These provide the necessary framework to test conceptual hypotheses of flow and transport at different scales and predict flow and transport behavior under a variety of climatic conditions. In addition, this Model Report supports several PA activities, including abstractions, particle-tracking transport simulations, and the UZ Radionuclide Transport Model.

  11. Educational game models: conceptualization and evaluation ...

    African Journals Online (AJOL)

    Educational game models: conceptualization and evaluation. ... The Game Object Model (GOM), that marries educational theory and game design, forms the basis for the development of the Persona Outlining ... AJOL African Journals Online.

  12. Conceptual Models Core to Good Design

    CERN Document Server

    Johnson, Jeff

    2011-01-01

    People make use of software applications in their activities, applying them as tools in carrying out tasks. That this use should be good for people--easy, effective, efficient, and enjoyable--is a principal goal of design. In this book, we present the notion of Conceptual Models, and argue that Conceptual Models are core to achieving good design. From years of helping companies create software applications, we have come to believe that building applications without Conceptual Models is just asking for designs that will be confusing and difficult to learn, remember, and use. We show how Concept

  13. Template for Conceptual Model Construction: Model Review and Corps Applications

    National Research Council Canada - National Science Library

    Henderson, Jim E; O'Neil, L. J

    2007-01-01

    .... The template will expedite conceptual model construction by providing users with model parameters and potential model components, building on a study team's knowledge and experience, and promoting...

  14. A unifying conceptual model of entrepreneurial management

    DEFF Research Database (Denmark)

    Senderovitz, Martin

    This article offers a systematic analysis and synthesis of the area of entrepreneurial management. Through a presentation of two main perspectives on entrepreneurial management and a newly developed unifying conceptual entrepreneurial management model, the paper discusses a number of theoretical...

  15. Guide for developing conceptual models for ecological risk assessments

    International Nuclear Information System (INIS)

    Suter, G.W., II.

    1996-05-01

    Ecological conceptual models are the result of the problem formulation phase of an ecological risk assessment, which is an important component of the Remedial Investigation process. They present hypotheses of how the site contaminants might affect the site ecology. The contaminant sources, routes, media, routes, and endpoint receptors are presented in the form of a flow chart. This guide is for preparing the conceptual models; use of this guide will standardize the models so that they will be of high quality, useful to the assessment process, and sufficiently consistent so that connections between sources of exposure and receptors can be extended across operable units (OU). Generic conceptual models are presented for source, aquatic integrator, groundwater integrator, and terrestrial OUs

  16. OWL references in ORM conceptual modelling

    Science.gov (United States)

    Matula, Jiri; Belunek, Roman; Hunka, Frantisek

    2017-07-01

    Object Role Modelling methodology is the fact-based type of conceptual modelling. The aim of the paper is to emphasize a close connection to OWL documents and its possible mutual cooperation. The definition of entities or domain values is an indispensable part of the conceptual schema design procedure defined by the ORM methodology. Many of these entities are already defined in OWL documents. Therefore, it is not necessary to declare entities again, whereas it is possible to utilize references from OWL documents during modelling of information systems.

  17. 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.

  18. Analysis of Subjective Conceptualizations Towards Collective Conceptual Modelling

    DEFF Research Database (Denmark)

    Glückstad, Fumiko Kano; Herlau, Tue; Schmidt, Mikkel Nørgaard

    2013-01-01

    This work is conducted as a preliminary study for a project where individuals' conceptualizations of domain knowledge will thoroughly be analyzed across 150 subjects from 6 countries. The project aims at investigating how humans' conceptualizations differ according to different types of mother la...

  19. Conceptual modelling of human resource evaluation process

    Directory of Open Access Journals (Sweden)

    Negoiţă Doina Olivia

    2017-01-01

    Full Text Available Taking into account the highly diverse tasks which employees have to fulfil due to complex requirements of nowadays consumers, the human resource within an enterprise has become a strategic element for developing and exploiting products which meet the market expectations. Therefore, organizations encounter difficulties when approaching the human resource evaluation process. Hence, the aim of the current paper is to design a conceptual model of the aforementioned process, which allows the enterprises to develop a specific methodology. In order to design the conceptual model, Business Process Modelling instruments were employed - Adonis Community Edition Business Process Management Toolkit using the ADONIS BPMS Notation. The conceptual model was developed based on an in-depth secondary research regarding the human resource evaluation process. The proposed conceptual model represents a generic workflow (sequential and/ or simultaneously activities, which can be extended considering the enterprise’s needs regarding their requirements when conducting a human resource evaluation process. Enterprises can benefit from using software instruments for business process modelling as they enable process analysis and evaluation (predefined / specific queries and also model optimization (simulations.

  20. Event-Based Conceptual Modeling

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    The paper demonstrates that a wide variety of event-based modeling approaches are based on special cases of the same general event concept, and that the general event concept can be used to unify the otherwise unrelated fields of information modeling and process modeling. A set of event......-based modeling approaches are analyzed and the results are used to formulate a general event concept that can be used for unifying the seemingly unrelated event concepts. Events are characterized as short-duration processes that have participants, consequences, and properties, and that may be modeled in terms...... of information structures. The general event concept can be used to guide systems analysis and design and to improve modeling approaches....

  1. FRSAD conceptual modeling of aboutness

    CERN Document Server

    Zeng, Marcia; Žumer, Maja

    2012-01-01

    The first comprehensive exploration of the development and use of the International Federation of Library Associations and Institutions' (IFLA) newly released model for subject authority data, covering everything from the rationale for creating the model to practical steps for implementing it.

  2. Medieval Kingship: A Conceptual Model.

    Science.gov (United States)

    Renna, Thomas

    1982-01-01

    Presents a model which describes the theories of kingship in Germany, France, and England between 800-1380 A.D. The three royal functions were defense of the realm, defense of the church, and material and moral improvement of royal subjects. (AM)

  3. Logistics and Transport - a conceptual model

    DEFF Research Database (Denmark)

    Jespersen, Per Homann; Drewes, Lise

    2004-01-01

    This paper describes how the freight transport sector is influenced by logistical principles of production and distribution. It introduces new ways of understanding freight transport as an integrated part of the changing trends of mobility. By introducing a conceptual model for understanding...... the interaction between logistics and transport, it points at ways to over-come inherent methodological difficulties when studying this relation...

  4. The conceptualization model problem—surprise

    Science.gov (United States)

    Bredehoeft, John

    2005-03-01

    The foundation of model analysis is the conceptual model. Surprise is defined as new data that renders the prevailing conceptual model invalid; as defined here it represents a paradigm shift. Limited empirical data indicate that surprises occur in 20-30% of model analyses. These data suggest that groundwater analysts have difficulty selecting the appropriate conceptual model. There is no ready remedy to the conceptual model problem other than (1) to collect as much data as is feasible, using all applicable methods—a complementary data collection methodology can lead to new information that changes the prevailing conceptual model, and (2) for the analyst to remain open to the fact that the conceptual model can change dramatically as more information is collected. In the final analysis, the hydrogeologist makes a subjective decision on the appropriate conceptual model. The conceptualization problem does not render models unusable. The problem introduces an uncertainty that often is not widely recognized. Conceptual model uncertainty is exacerbated in making long-term predictions of system performance. C'est le modèle conceptuel qui se trouve à base d'une analyse sur un modèle. On considère comme une surprise lorsque le modèle est invalidé par des données nouvelles; dans les termes définis ici la surprise est équivalente à un change de paradigme. Des données empiriques limitées indiquent que les surprises apparaissent dans 20 à 30% des analyses effectuées sur les modèles. Ces données suggèrent que l'analyse des eaux souterraines présente des difficultés lorsqu'il s'agit de choisir le modèle conceptuel approprié. Il n'existe pas un autre remède au problème du modèle conceptuel que: (1) rassembler autant des données que possible en utilisant toutes les méthodes applicables—la méthode des données complémentaires peut conduire aux nouvelles informations qui vont changer le modèle conceptuel, et (2) l'analyste doit rester ouvert au fait

  5. Conceptual geohydrological model of the separations area

    International Nuclear Information System (INIS)

    Root, R.W.; Marine, I.W.

    1977-01-01

    Subsurface drilling in and around the Separations Areas (F-Area and H-Area of the Savannah River Plant) is providing detailed information for a conceptual model of the geology and hydrology underlying these areas. This conceptual model will provide the framework needed for a mathematical model of groundwater movement beneath these areas. Existing information substantiates the presence of two areally extensive clay layers and several discontinuous clay and sandy-clay layers. These layers occur in and between beds of clayey and silty sand that make up most of the subsurface material. Within these sand beds are geologic units of differing hydraulic conductivity. For the present scale of the model, the subsurface information is considered adequate in H-Area, but additional drilling is planned in F-Area

  6. A Conceptual Model of Military Recruitment

    Science.gov (United States)

    2009-10-01

    Hiring Expectancies – Expectancy (VIE) Theory ( Vroom , 1996) states individuals choose among a set of employment alternatives on the basis of the...A Conceptual Model of Military Recruitment Presented at NATO Technical Course HFM 180 – Strategies to Address Recruiting and Retention Issues in...the Military Fariya Syed October, 2009 Based on A Proposed Model Of Military Recruitment (Schreurs & Syed, 2007) Report Documentation Page

  7. Regional hydrogeological conceptual model of candidate Beishan area for high level radioactive waste disposal repository

    International Nuclear Information System (INIS)

    Wang Hailong; Guo Yonghai

    2014-01-01

    The numerical modeling of groundwater flow is an important aspect of hydrogeological assessment in siting of a high level radioactive waste disposal repository. Hydrogeological conceptual model is the basic and premise of numerical modeling of groundwater flow. Based on the hydrogeological analysis of candidate Beishan area, surface water system was created by using DEM data and the modeling area is determined. Three-dimensional hydrogeological structure model was created through GMS software. On the basis of analysis and description of boundary condition, flow field, groundwater budget and hydrogeological parameters, hydrogeological conceptual model was set up for the Beishan area. (authors)

  8. The conceptual model of organization social responsibility

    OpenAIRE

    LUO, Lan; WEI, Jingfu

    2014-01-01

    With the developing of the research of CSR, people more and more deeply noticethat the corporate should take responsibility. Whether other organizations besides corporatesshould not take responsibilities beyond their field? This paper puts forward theconcept of organization social responsibility on the basis of the concept of corporate socialresponsibility and other theories. And the conceptual models are built based on theconception, introducing the OSR from three angles: the types of organi...

  9. Conceptual models for cumulative risk assessment.

    Science.gov (United States)

    Linder, Stephen H; Sexton, Ken

    2011-12-01

    In the absence of scientific consensus on an appropriate theoretical framework, cumulative risk assessment and related research have relied on speculative conceptual models. We argue for the importance of theoretical backing for such models and discuss 3 relevant theoretical frameworks, each supporting a distinctive "family" of models. Social determinant models postulate that unequal health outcomes are caused by structural inequalities; health disparity models envision social and contextual factors acting through individual behaviors and biological mechanisms; and multiple stressor models incorporate environmental agents, emphasizing the intermediary role of these and other stressors. The conclusion is that more careful reliance on established frameworks will lead directly to improvements in characterizing cumulative risk burdens and accounting for disproportionate adverse health effects.

  10. Modelling framework for groundwater flow at Sellafield

    International Nuclear Information System (INIS)

    Hooper, A.J.; Billington, D.E.; Herbert, A.W.

    1995-01-01

    The principal objective of Nirex is to develop a single deep geological repository for the safe disposal of low- and intermediate-level radioactive waste. In safety assessment, use is made of a variety of conceptual models that form the basis for modelling of the pathways by which radionuclides might return to the environment. In this paper, the development of a conceptual model for groundwater flow and transport through fractured rock on the various scales of interest is discussed. The approach is illustrated by considering how some aspects of the conceptual model are developed in particular numerical models. These representations of the conceptual model use fracture network geometries based on realistic rock properties. (author). refs., figs., tabs

  11. Business Model Innovation: An Integrative Conceptual Framework

    Directory of Open Access Journals (Sweden)

    Bernd Wirtz

    2017-01-01

    Full Text Available Purpose: The point of departure of this exploratory study is the gap between the increasing importance of business model innovation (BMI in science and management and the limited conceptual assistance available. Therefore, the study identi es and explores scattered BMI insights and deduces them into an integrative framework to enhance our understanding about this phenomenon and to present a helpful guidance for researchers and practitioners. Design/Methodology/Approach: The study identi es BMI insights through a literature-based investigation and consolidates them into an integrative BMI framework that presents the key elements and dimensions of BMI as well as their presumed relationships. Findings: The study enhances our understanding about the key elements and dimensions of BMI, presents further conceptual insights into the BMI phenomenon, supplies implications for science and management, and may serve as a helpful guidance for future research. Practical Implications: The presented framework provides managers with a tool to identify critical BMI issues and can serve as a conceptual BMI guideline. Research limitations: Given the vast amount of academic journals, it is unlikely that every applicable scienti c publication is included in the analysis. The illustrative examples are descriptive in nature, and thus do not provide empirical validity. Several implications for future research are provided. Originality/Value: The study’s main contribution lies in the unifying approach of the dispersed BMI knowledge. Since our understanding of BMI is still limited, this study should provide the necessary insights and conceptual assistance to further develop the concept and guide its practical application.

  12. Conceptual Model of Dynamic Geographic Environment

    Directory of Open Access Journals (Sweden)

    Martínez-Rosales Miguel Alejandro

    2014-04-01

    Full Text Available In geographic environments, there are many and different types of geographic entities such as automobiles, trees, persons, buildings, storms, hurricanes, etc. These entities can be classified into two groups: geographic objects and geographic phenomena. By its nature, a geographic environment is dynamic, thus, it’s static modeling is not sufficient. Considering the dynamics of geographic environment, a new type of geographic entity called event is introduced. The primary target is a modeling of geographic environment as an event sequence, because in this case the semantic relations are much richer than in the case of static modeling. In this work, the conceptualization of this model is proposed. It is based on the idea to process each entity apart instead of processing the environment as a whole. After that, the so called history of each entity and its spatial relations to other entities are defined to describe the whole environment. The main goal is to model systems at a conceptual level that make use of spatial and temporal information, so that later it can serve as the semantic engine for such systems.

  13. Achievements and Problems of Conceptual Modelling

    Science.gov (United States)

    Thalheim, Bernhard

    Database and information systems technology has substantially changed. Nowadays, content management systems, (information-intensive) web services, collaborating systems, internet databases, OLAP databases etc. have become buzzwords. At the same time, object-relational technology has gained the maturity for being widely applied. Conceptual modelling has not (yet) covered all these novel topics. It has been concentrated for more than two decades around specification of structures. Meanwhile, functionality, interactivity and distribution must be included into conceptual modelling of information systems. Also, some of the open problems that have been already discussed in 1987 [15, 16] still remain to be open. At the same time, novel models such as object-relational models or XML-based models have been developed. They did not overcome all the problems but have been sharpening and extending the variety of open problems. The open problem presented are given for classical areas of database research, i.e., structuring and functionality. The entire are of distribution and interaction is currently an area of very intensive research.

  14. Conceptual Frameworks in the Doctoral Research Process: A Pedagogical Model

    Science.gov (United States)

    Berman, Jeanette; Smyth, Robyn

    2015-01-01

    This paper contributes to consideration of the role of conceptual frameworks in the doctoral research process. Through reflection on the two authors' own conceptual frameworks for their doctoral studies, a pedagogical model has been developed. The model posits the development of a conceptual framework as a core element of the doctoral…

  15. A Structural Equation Model of Conceptual Change in Physics

    Science.gov (United States)

    Taasoobshirazi, Gita; Sinatra, Gale M.

    2011-01-01

    A model of conceptual change in physics was tested on introductory-level, college physics students. Structural equation modeling was used to test hypothesized relationships among variables linked to conceptual change in physics including an approach goal orientation, need for cognition, motivation, and course grade. Conceptual change in physics…

  16. A conceptual model of referee efficacy

    Directory of Open Access Journals (Sweden)

    Félix eGuillén

    2011-02-01

    Full Text Available This paper presents a conceptual model of referee efficacy, defines the concept, proposes sources of referee specific efficacy information, and suggests consequences of having high or low referee efficacy. Referee efficacy is defined as the extent to which referees believe they have the capacity to perform successfully in their job. Referee efficacy beliefs are hypothesized to be influenced by mastery experiences, referee knowledge/education, support from significant others, physical/mental preparedness, environmental comfort, and perceived anxiety. In turn, referee efficacy beliefs are hypothesized to influence referee performance, referee stress, athlete rule violations, athlete satisfaction, and co-referee satisfaction.

  17. Sierra toolkit computational mesh conceptual model

    International Nuclear Information System (INIS)

    Baur, David G.; Edwards, Harold Carter; Cochran, William K.; Williams, Alan B.; Sjaardema, Gregory D.

    2010-01-01

    The Sierra Toolkit computational mesh is a software library intended to support massively parallel multi-physics computations on dynamically changing unstructured meshes. This domain of intended use is inherently complex due to distributed memory parallelism, parallel scalability, heterogeneity of physics, heterogeneous discretization of an unstructured mesh, and runtime adaptation of the mesh. Management of this inherent complexity begins with a conceptual analysis and modeling of this domain of intended use; i.e., development of a domain model. The Sierra Toolkit computational mesh software library is designed and implemented based upon this domain model. Software developers using, maintaining, or extending the Sierra Toolkit computational mesh library must be familiar with the concepts/domain model presented in this report.

  18. Summary of Vadose -- Zone Conceptual Models for Flow and Contaminant Transport and 1999 - 2003 Progress on Resolving Deficiencies in Understanding the Vadose Zone at the INEEL

    Energy Technology Data Exchange (ETDEWEB)

    Robert C. Starr; Dana L. Dettmers; Brennon R. Orr; Thomas R. Wood

    2003-12-01

    The thick vadose zone that underlies the Idaho National Engineering and Environmental Laboratory has been recognized both as an avenue through which contaminants disposed at or near the ground surface can migrate to groundwater in the underlying Eastern Snake River Plain aquifer, and as a barrier to the movement of contaminants into the aquifer. Flow and contaminant transport in the vadose zone at the INEEL is complicated by the highly heterogeneous nature of the geologic framework and by the variations in the behavior of different contaminants in the subsurface. The state of knowledge concerning flow and contaminant transport in the vadose zone at and near the INEEL IN 1999 was summarized in Deficiencies in Vadose Zone Understanding at the Idaho National Engineering and Environmental Laboratory (Wood et al., 2000). These authors identified deficiencies in knowledge of flow and contaminant transport processes in the vadose zone, and provided recommendations for additional work that should be conducted to address these deficiencies. In the period since (Wood et al., 2000) was prepared, research has been published that, to some degree, address these deficiencies. This document provides a bibliography of reports, journal articles, and conference proceedings published 1999 through mid-2003 that are relevant to the vadose zone at or near the INEEL and provides a brief description of each work. Publications that address specific deficiencies or recommendations are identified, and pertinent information from selected publications is presented.

  19. A Proposed Conceptual Model of Military Medical Readiness

    National Research Council Canada - National Science Library

    Van Hall, Brian M

    2007-01-01

    .... The basis for the proposed conceptual model builds on common and accepted latent variable and theoretical modeling techniques proposed by healthcare scholars, organizational theorists, mathematical...

  20. Testing an integral conceptual model of frailty.

    Science.gov (United States)

    Gobbens, Robbert J; van Assen, Marcel A; Luijkx, Katrien G; Schols, Jos M

    2012-09-01

    This paper is a report of a study conducted to test three hypotheses derived from an integral conceptual model of frailty.   The integral model of frailty describes the pathway from life-course determinants to frailty to adverse outcomes. The model assumes that life-course determinants and the three domains of frailty (physical, psychological, social) affect adverse outcomes, the effect of disease(s) on adverse outcomes is mediated by frailty, and the effect of frailty on adverse outcomes depends on the life-course determinants. In June 2008 a questionnaire was sent to a sample of community-dwelling people, aged 75 years and older (n = 213). Life-course determinants and frailty were assessed using the Tilburg frailty indicator. Adverse outcomes were measured using the Groningen activity restriction scale, the WHOQOL-BREF and questions regarding healthcare utilization. The effect of seven self-reported chronic diseases was examined. Life-course determinants, chronic disease(s), and frailty together explain a moderate to large part of the variance of the seven continuous adverse outcomes (26-57%). All these predictors together explained a significant part of each of the five dichotomous adverse outcomes. The effect of chronic disease(s) on all 12 adverse outcomes was mediated at least partly by frailty. The effect of frailty domains on adverse outcomes did not depend on life-course determinants. Our finding that the adverse outcomes are differently and uniquely affected by the three domains of frailty (physical, psychological, social), and life-course determinants and disease(s), emphasizes the importance of an integral conceptual model of frailty. © 2011 Blackwell Publishing Ltd.

  1. Conceptual models of microseismicity induced by fluid injection

    Science.gov (United States)

    Baro Urbea, J.; Lord-May, C.; Eaton, D. W. S.; Joern, D.

    2017-12-01

    Variations in the pore pressure due to fluid invasion are accountable for microseismic activity recorded in geothermal systems and during hydraulic fracturing operations. To capture this phenomenon on a conceptual level, invasion percolation models have been suggested to represent the flow network of fluids within a porous media and seismic activity is typically considered to be directly related to the expansion of the percolated area. Although such models reproduce scale-free frequency-magnitude distributions, the associated b-values of the Gutenberg-Richter relation do not align with observed data. Here, we propose an alternative conceptual invasion percolation model that decouples the fluid propagation from the microseismic events. Instead of a uniform pressure, the pressure is modeled to decay along the distance from the injection site. Wet fracture events are simulated with a stochastic spring block model exhibiting stick-slip dynamics as a result of the variations of the pore pressure. We show that the statistics of the stick-slip events are scale-free, but now the b-values depend on the level of heterogeneity in the local static friction coefficients. Thus, this model is able to reproduce the wide spectrum of b-values observed in field catalogs associated with fluid induced microseismicity. Moreover, the spatial distribution of microseismic events is also consistent with observations.

  2. A conceptual competitive intelligence quality assurance model

    Directory of Open Access Journals (Sweden)

    Tshilidzi Eric Nenzhelele

    2015-12-01

    Full Text Available Competitive Intelligence (CI improves the quality of product and service, decision-making and it improves quality of life. However, it has been established that decision makers are not happy about the quality of CI. This is because enterprises fail in quality assurance of CI. It has been concluded that most enterprises are clueless concerning CI quality assurance. Studies that previously attempted to resolve CI quality problem were limited in scope and focused too much on the quality of information than the overall CI quality. The purpose of this study is to propose a conceptual CI quality assurance model which will help in quality assurance of CI. The research was qualitative in nature and used content analysis.

  3. A conceptual holding model for veterinary applications

    Directory of Open Access Journals (Sweden)

    Nicola Ferrè

    2014-05-01

    Full Text Available Spatial references are required when geographical information systems (GIS are used for the collection, storage and management of data. In the veterinary domain, the spatial component of a holding (of animals is usually defined by coordinates, and no other relevant information needs to be interpreted or used for manipulation of the data in the GIS environment provided. Users trying to integrate or reuse spatial data organised in such a way, frequently face the problem of data incompatibility and inconsistency. The root of the problem lies in differences with respect to syntax as well as variations in the semantic, spatial and temporal representations of the geographic features. To overcome these problems and to facilitate the inter-operability of different GIS, spatial data must be defined according to a “schema” that includes the definition, acquisition, analysis, access, presentation and transfer of such data between different users and systems. We propose an application “schema” of holdings for GIS applications in the veterinary domain according to the European directive framework (directive 2007/2/EC - INSPIRE. The conceptual model put forward has been developed at two specific levels to produce the essential and the abstract model, respectively. The former establishes the conceptual linkage of the system design to the real world, while the latter describes how the system or software works. The result is an application “schema” that formalises and unifies the information-theoretic foundations of how to spatially represent a holding in order to ensure straightforward information-sharing within the veterinary community.

  4. Creating a Universe, a Conceptual Model

    Directory of Open Access Journals (Sweden)

    James R. Johnson

    2016-10-01

    Full Text Available Space is something. Space inherently contains laws of nature: universal rules (mathematics, space dimensions, types of forces, types of fields, and particle species, laws (relativity, quantum mechanics, thermodynamics, and electromagnetism and symmetries (Lorentz, Gauge, and symmetry breaking. We have significant knowledge about these laws of nature because all our scientific theories assume their presence. Their existence is critical for developing either a unique theory of our universe or more speculative multiverse theories. Scientists generally ignore the laws of nature because they “are what they are” and because visualizing different laws of nature challenges the imagination. This article defines a conceptual model separating space (laws of nature from the universe’s energy source (initial conditions and expansion (big bang. By considering the ramifications of changing the laws of nature, initial condition parameters, and two variables in the big bang theory, the model demonstrates that traditional fine tuning is not the whole story when creating a universe. Supporting the model, space and “nothing” are related to the laws of nature, mathematics and multiverse possibilities. Speculation on the beginning of time completes the model.

  5. A Conceptual Modeling Approach for OLAP Personalization

    Science.gov (United States)

    Garrigós, Irene; Pardillo, Jesús; Mazón, Jose-Norberto; Trujillo, Juan

    Data warehouses rely on multidimensional models in order to provide decision makers with appropriate structures to intuitively analyze data with OLAP technologies. However, data warehouses may be potentially large and multidimensional structures become increasingly complex to be understood at a glance. Even if a departmental data warehouse (also known as data mart) is used, these structures would be also too complex. As a consequence, acquiring the required information is more costly than expected and decision makers using OLAP tools may get frustrated. In this context, current approaches for data warehouse design are focused on deriving a unique OLAP schema for all analysts from their previously stated information requirements, which is not enough to lighten the complexity of the decision making process. To overcome this drawback, we argue for personalizing multidimensional models for OLAP technologies according to the continuously changing user characteristics, context, requirements and behaviour. In this paper, we present a novel approach to personalizing OLAP systems at the conceptual level based on the underlying multidimensional model of the data warehouse, a user model and a set of personalization rules. The great advantage of our approach is that a personalized OLAP schema is provided for each decision maker contributing to better satisfy their specific analysis needs. Finally, we show the applicability of our approach through a sample scenario based on our CASE tool for data warehouse development.

  6. Proglacial Hydrogeology of the Cordillera Blanca (Peru): Integrating Field Observations with Hydrogeophysical Inversions to Inform Groundwater Flow Simulations and Conceptual Models

    Science.gov (United States)

    Glas, R. L.; Lautz, L.; McKenzie, J. M.; Moucha, R.; Mark, B. G.

    2017-12-01

    Geological and depositional conditions of the glaciated Cordillera Blanca in Peru have given way to proglacial aquifer systems that contribute substantially to regional streams and rivers, particularly during the dry season. As glacial retreat accelerates, the dry season water budget will be increasingly dominated by groundwater inputs, although predictions of future groundwater quantities require estimations of groundwater storage capacity, aquifer extents, and groundwater residence time. We present a characterization of the sediment structure in a prototypical proglacial valley in the central portion of the range, the Quilcayhuanca Valley. Northern and Central valleys of the Cordillera Blanca feature ubiquitous talus deposits that line the steep granite walls, and have become partially buried beneath lacustrine sediments deposited in proglacial lake beds. The portion of the talus still exposed near the valley walls provides recharge to deeper portions of the valley aquifers that underlie lacustrine clay, resulting in a confined aquifer system that is connected to the surface via perennial springs. Seismic refraction surveys reveal an interface separating relatively slow ( 400-800 m/s) and fast ( 2500 m/s) p-wave velocities. The depth of this refractor coincides with the depth to buried talus observed in drilling records. Electrical resistivity tomography profiles of the same transect show depths near the buried talus to be relatively conductive (10-100 Ωm). At these depths, we hypothesize that electrical conductance is elevated by saturated clay particles in the sediment matrix of the talus deposit. The resistivity models all show a more resistive ( 700 Ω m) region at depth, likely corresponding to a more hydraulically conductive material. The resistive zone is interpreted to be a deeper portion of a buried talus deposit that did not accumulate clay in the matrix. Other possibilities include a thick deposit of gravelly glacial outwash, or a relatively clay

  7. COSMO: a conceptual framework for service modelling and refinement

    NARCIS (Netherlands)

    Quartel, Dick; Steen, Maarten W.A.; Pokraev, S.; van Sinderen, Marten J.

    This paper presents a conceptual framework for service modelling and refinement, called the COSMO (COnceptual Service MOdelling) framework. This framework provides concepts to model and reason about services, and to support operations, such as composition and discovery, which are performed on them

  8. A Conceptual Framework for the Indirect Method of Reporting Net Cash Flow from Operating Activities

    Science.gov (United States)

    Wang, Ting J.

    2010-01-01

    This paper describes the fundamental concept of the reconciliation behind the indirect method of the statement of cash flows. A conceptual framework is presented to demonstrate how accrual and cash-basis accounting methods relate to each other and to illustrate the concept of reconciling these two accounting methods. The conceptual framework…

  9. Conceptual plan: Two-Phase Flow Laboratory Program for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Howarth, S.M.

    1993-07-01

    The Salado Two-Phase Flow Laboratory Program was established to address concerns regarding two-phase flow properties and to provide WIPP-specific, geologically consistent experimental data to develop more appropriate correlations for Salado rock to replace those currently used in Performance Assessment models. Researchers in Sandia's Fluid Flow and Transport Department originally identified and emphasized the need for laboratory measurements of Salado threshold pressure and relative permeability. The program expanded to include the measurement of capillary pressure, rock compressibility, porosity, and intrinsic permeability and the assessment of core damage. Sensitivity analyses identified the anhydrite interbed layers as the most likely path for the dissipation of waste-generated gas from waste-storage rooms because of their relatively high permeability. Due to this the program will initially focus on the anhydrite interbed material. The program may expand to include similar rock and flow measurements on other WIPP materials including impure halite, pure halite, and backfill and seal materials. This conceptual plan presents the scope, objectives, and historical documentation of the development of the Salado Two-Phase Flow Program through January 1993. Potential laboratory techniques for assessing core damage and measuring porosity, rock compressibility, capillary and threshold pressure, permeability as a function of stress, and relative permeability are discussed. Details of actual test designs, test procedures, and data analysis are not included in this report, but will be included in the Salado Two-Phase Flow Laboratory Program Test Plan pending the results of experimental and other scoping activities in FY93

  10. Conceptual models in the field of library catalogues

    Directory of Open Access Journals (Sweden)

    Marija Petek

    2000-01-01

    Full Text Available The publishing world is changing quickly and so must also bibliographic control. It is tirne to re-examine cataloguing rules and MARC formats. This can be done by the method of conceptual modelling. Some conceptual models are presented; an IFLA study on the functional requirements for bibliographic records is described in detail.

  11. Modeling in transport phenomena a conceptual approach

    CERN Document Server

    Tosun, Ismail

    2007-01-01

    Modeling in Transport Phenomena, Second Edition presents and clearly explains with example problems the basic concepts and their applications to fluid flow, heat transfer, mass transfer, chemical reaction engineering and thermodynamics. A balanced approach is presented between analysis and synthesis, students will understand how to use the solution in engineering analysis. Systematic derivations of the equations and the physical significance of each term are given in detail, for students to easily understand and follow up the material. There is a strong incentive in science and engineering to

  12. Conceptualizing Telehealth in Nursing Practice: Advancing a Conceptual Model to Fill a Virtual Gap.

    Science.gov (United States)

    Nagel, Daniel A; Penner, Jamie L

    2016-03-01

    Increasingly nurses use various telehealth technologies to deliver health care services; however, there has been a lag in research and generation of empirical knowledge to support nursing practice in this expanding field. One challenge to generating knowledge is a gap in development of a comprehensive conceptual model or theoretical framework to illustrate relationships of concepts and phenomena inherent to adoption of a broad range of telehealth technologies to holistic nursing practice. A review of the literature revealed eight published conceptual models, theoretical frameworks, or similar entities applicable to nursing practice. Many of these models focus exclusively on use of telephones and four were generated from qualitative studies, but none comprehensively reflect complexities of bridging nursing process and elements of nursing practice into use of telehealth. The purpose of this article is to present a review of existing conceptual models and frameworks, discuss predominant themes and features of these models, and present a comprehensive conceptual model for telehealth nursing practice synthesized from this literature for consideration and further development. This conceptual model illustrates characteristics of, and relationships between, dimensions of telehealth practice to guide research and knowledge development in provision of holistic person-centered care delivery to individuals by nurses through telehealth technologies. © The Author(s) 2015.

  13. A CONCEPTUAL MODEL FOR IMPROVED PROJECT SELECTION AND PRIORITISATION

    Directory of Open Access Journals (Sweden)

    P. J. Viljoen

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Project portfolio management processes are often designed and operated as a series of stages (or project phases and gates. However, the flow of such a process is often slow, characterised by queues waiting for a gate decision and by repeated work from previous stages waiting for additional information or for re-processing. In this paper the authors propose a conceptual model that applies supply chain and constraint management principles to the project portfolio management process. An advantage of the proposed model is that it provides the ability to select and prioritise projects without undue changes to project schedules. This should result in faster flow through the system.

    AFRIKAANSE OPSOMMING: Prosesse om portefeuljes van projekte te bestuur word normaalweg ontwerp en bedryf as ’n reeks fases en hekke. Die vloei deur so ’n proses is dikwels stadig en word gekenmerk deur toue wat wag vir besluite by die hekke en ook deur herwerk van vorige fases wat wag vir verdere inligting of vir herprosessering. In hierdie artikel word ‘n konseptuele model voorgestel. Die model berus op die beginsels van voorsieningskettings sowel as van beperkingsbestuur, en bied die voordeel dat projekte geselekteer en geprioritiseer kan word sonder onnodige veranderinge aan projekskedules. Dit behoort te lei tot versnelde vloei deur die stelsel.

  14. Role of conceptual models in nuclear power plant operation

    International Nuclear Information System (INIS)

    Williams, M.D.; Moran, T.P.; Brown, J.S.

    1982-01-01

    A crucial objective in plant operation (and perhaps licensing) ought to be to explicitly train operators to develop, perhaps with computer aids, robust conceptual models of the plants they control. The question is whether we are actually able to develop robust conceptual models and validate their robustness. Cognitive science is just beginning to come to grips with this problem. This paper describes some of the evolving technology for building conceptual models of physical mechanisms and some of the implications of such models in the context of nuclear power plant operation

  15. National Identity: Conceptual models, discourses and political change

    DEFF Research Database (Denmark)

    Harder, Peter

    2014-01-01

    of conceptual models or discourses. This is especially important in cases that involve conflictive political issues such as national and ethnic identity. The article reports on a historical project with a linguistic dimension in my department (PI Stuart Ward, cf. Ward 2004), which aims to throw light......Cognitive Linguistics has demonstrated the applicability of a conceptual approach to the understanding of political issues, cf. Lakoff (2008) and many others. From a different perspective, critical discourse analysis has approached political concepts with a focus on issues involving potentially...... divisive features such as race, class, gender and ethnic identity. Although discourses are not identical to conceptual models, conceptual models are typically manifested in discourse, and discourses are typically reflections of conceptualizations, a theme explored e.g. in Hart and Lukes (2007). As argued...

  16. Toolkit for Conceptual Modeling (TCM): User's Guide and Reference

    NARCIS (Netherlands)

    Dehne, F.; Wieringa, Roelf J.

    1997-01-01

    The Toolkit for Conceptual Modeling (TCM) is a suite of graphical editors for a number of graphical notation systems that are used in software specification methods. The notations can be used to represent the conceptual structure of the software - hence the name of the suite. This manual describes

  17. A conceptual framework that links pollinator foraging behavior to gene flow

    Science.gov (United States)

    In insect-pollinated crops such as alfalfa, a better understanding of how pollinator foraging behavior affects gene flow could lead to the development of management strategies to reduce gene flow and facilitate the coexistence of distinct seed-production markets. Here, we introduce a conceptual fram...

  18. Shallow groundwater in the Matanuska-Susitna Valley, Alaska—Conceptualization and simulation of flow

    Science.gov (United States)

    Kikuchi, Colin P.

    2013-01-01

    The Matanuska-Susitna Valley is in the Upper Cook Inlet Basin and is currently undergoing rapid population growth outside of municipal water and sewer service areas. In response to concerns about the effects of increasing water use on future groundwater availability, a study was initiated between the Alaska Department of Natural Resources and the U.S. Geological Survey. The goals of the study were (1) to compile existing data and collect new data to support hydrogeologic conceptualization of the study area, and (2) to develop a groundwater flow model to simulate flow dynamics important at the regional scale. The purpose of the groundwater flow model is to provide a scientific framework for analysis of regional-scale groundwater availability. To address the first study goal, subsurface lithologic data were compiled into a database and were used to construct a regional hydrogeologic framework model describing the extent and thickness of hydrogeologic units in the Matanuska-Susitna Valley. The hydrogeologic framework model synthesizes existing maps of surficial geology and conceptual geochronologies developed in the study area with the distribution of lithologies encountered in hundreds of boreholes. The geologic modeling package Geological Surveying and Investigation in Three Dimensions (GSI3D) was used to construct the hydrogeologic framework model. In addition to characterizing the hydrogeologic framework, major groundwater-budget components were quantified using several different techniques. A land-surface model known as the Deep Percolation Model was used to estimate in-place groundwater recharge across the study area. This model incorporates data on topography, soils, vegetation, and climate. Model-simulated surface runoff was consistent with observed streamflow at U.S. Geological Survey streamgages. Groundwater withdrawals were estimated on the basis of records from major water suppliers during 2004-2010. Fluxes between groundwater and surface water were

  19. The treatment of conceptual model uncertainty in the Nagra programme: a few examples

    International Nuclear Information System (INIS)

    Zuidema, P.; Gautschi, A.; Smith, P.; Vomvoris, S.

    1995-01-01

    In this paper, a few examples are discussed which demonstrate how conceptual model uncertainty is treated within the Nagra programme. These examples cover geometric aspects, small-scale properties of the host rock and direction of the flow paths. Based on the examples, the pragmatic approach adopted in performance assessment is briefly discussed. (author). 3 refs., 7 figs

  20. Towards a Model of Technology Adoption: A Conceptual Model Proposition

    Science.gov (United States)

    Costello, Pat; Moreton, Rob

    A conceptual model for Information Communication Technology (ICT) adoption by Small Medium Enterprises (SMEs) is proposed. The research uses several ICT adoption models as its basis with theoretical underpinning provided by the Diffusion of Innovation theory and the Technology Acceptance Model (TAM). Taking an exploratory research approach the model was investigated amongst 200 SMEs whose core business is ICT. Evidence from this study demonstrates that these SMEs face the same issues as all other industry sectors. This work points out weaknesses in SMEs environments regarding ICT adoption and suggests what they may need to do to increase the success rate of any proposed adoption. The methodology for development of the framework is described and recommendations made for improved Government-led ICT adoption initiatives. Application of the general methodology has resulted in new opportunities to embed the ethos and culture surrounding the issues into the framework of new projects developed as a result of Government intervention. A conceptual model is proposed that may lead to a deeper understanding of the issues under consideration.

  1. A conceptual model for the development and management of the ...

    African Journals Online (AJOL)

    A conceptual model for the development and management of the Cape Flats ... rainfall; this rainfall pattern has implications for recharge and water management issues in ... Keywords: water resource management, Cape Town, water quality, ...

  2. Technologies for conceptual modelling and intelligent query formulation

    CSIR Research Space (South Africa)

    Alberts, R

    2008-11-01

    Full Text Available The aim of the project is to devise and evaluate algorithms, methodologies, techniques and interaction paradigms to build a tool for conceptual modelling and query management of complex data repositories based on a framework with solid formal...

  3. Extracting conceptual models from user stories with Visual Narrator

    NARCIS (Netherlands)

    Lucassen, Garm; Robeer, Marcel; Dalpiaz, Fabiano; van der Werf, Jan Martijn E. M.; Brinkkemper, Sjaak

    2017-01-01

    Extracting conceptual models from natural language requirements can help identify dependencies, redundancies, and conflicts between requirements via a holistic and easy-to-understand view that is generated from lengthy textual specifications. Unfortunately, existing approaches never gained traction

  4. Conceptual Model for Effective Sports Marketing in Nigeria | Akarah ...

    African Journals Online (AJOL)

    Conceptual Model for Effective Sports Marketing in Nigeria. ... that are influenced by the sports market mix and sports consumers that are influenced by psychological factors and notes that; ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  5. Southern marl prairies conceptual ecological model

    Science.gov (United States)

    Davis, S.M.; Loftus, W.F.; Gaiser, E.E.; Huffman, A.E.

    2005-01-01

    About 190,000 ha of higher-elevation marl prairies flank either side of Shark River Slough in the southern Everglades. Water levels typically drop below the ground surface each year in this landscape. Consequently, peat soil accretion is inhibited, and substrates consist either of calcitic marl produced by algal periphyton mats or exposed limestone bedrock. The southern marl prairies support complex mosaics of wet prairie, sawgrass sawgrass (Cladium jamaicense), tree islands, and tropical hammock communities and a high diversity of plant species. However, relatively short hydroperiods and annual dry downs provide stressful conditions for aquatic fauna, affecting survival in the dry season when surface water is absent. Here, we present a conceptual ecological model developed for this landscape through scientific concensus, use of empirical data, and modeling. The two major societal drivers affecting the southern marl prairies are water management practices and agricultural and urban development. These drivers lead to five groups of ecosystem stressors: loss of spatial extent and connectivity, shortened hydroperiod and increased drought severity, extended hydroperiod and drying pattern reversals, introduction and spread of non-native trees, and introduction and spread of non-native fishes. Major ecological attributes include periphyton mats, plant species diversity and community mosaic, Cape Sable seaside sparrow (Ammodramus maritimus mirabilis), marsh fishes and associated aquatic fauna prey base, American alligator (Alligator mississippiensis), and wading bird early dry season foraging. Water management and development are hypothesized to have a negative effect on the ecological attributes of the southern marl prairies in the following ways. Periphyton mats have decreased in cover in areas where hydroperiod has been significantly reduced and changed in community composition due to inverse responses to increased nutrient availability. Plant species diversity and

  6. Conceptual Models and Guidelines for Clinical Assessment of Financial Capacity.

    Science.gov (United States)

    Marson, Daniel

    2016-09-01

    The ability to manage financial affairs is a life skill of critical importance, and neuropsychologists are increasingly asked to assess financial capacity across a variety of settings. Sound clinical assessment of financial capacity requires knowledge and appreciation of applicable clinical conceptual models and principles. However, the literature has presented relatively little conceptual guidance for clinicians concerning financial capacity and its assessment. This article seeks to address this gap. The article presents six clinical models of financial capacity : (1) the early gerontological IADL model of Lawton, (2) the clinical skills model and (3) related cognitive psychological model developed by Marson and colleagues, (4) a financial decision-making model adapting earlier decisional capacity work of Appelbaum and Grisso, (5) a person-centered model of financial decision-making developed by Lichtenberg and colleagues, and (6) a recent model of financial capacity in the real world developed through the Institute of Medicine. Accompanying presentation of the models is discussion of conceptual and practical perspectives they represent for clinician assessment. Based on the models, the article concludes by presenting a series of conceptually oriented guidelines for clinical assessment of financial capacity. In summary, sound assessment of financial capacity requires knowledge and appreciation of clinical conceptual models and principles. Awareness of such models, principles and guidelines will strengthen and advance clinical assessment of financial capacity. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. A chaotic-dynamical conceptual model to describe fluid flow and contaminant transport in a fractured vadose zone. 1997 progress report and presentations at the annual meeting, Ernest Orlando Lawrence Berkeley National Laboratory, December 3-4, 1997

    International Nuclear Information System (INIS)

    Faybishenko, B.; Doughty, C.; Geller, J.

    1998-07-01

    Understanding subsurface flow and transport processes is critical for effective assessment, decision-making, and remediation activities for contaminated sites. However, for fluid flow and contaminant transport through fractured vadose zones, traditional hydrogeological approaches are often found to be inadequate. In this project, the authors examine flow and transport through a fractured vadose zone as a deterministic chaotic dynamical process, and develop a model of it in these terms. Initially, the authors examine separately the geometric model of fractured rock and the flow dynamics model needed to describe chaotic behavior. Ultimately they will put the geometry and flow dynamics together to develop a chaotic-dynamical model of flow and transport in a fractured vadose zone. They investigate water flow and contaminant transport on several scales, ranging from small-scale laboratory experiments in fracture replicas and fractured cores, to field experiments conducted in a single exposed fracture at a basalt outcrop, and finally to a ponded infiltration test using a pond of 7 by 8 m. In the field experiments, they measure the time-variation of water flux, moisture content, and hydraulic head at various locations, as well as the total inflow rate to the subsurface. Such variations reflect the changes in the geometry and physics of water flow that display chaotic behavior, which they try to reconstruct using the data obtained. In the analysis of experimental data, a chaotic model can be used to predict the long-term bounds on fluid flow and transport behavior, known as the attractor of the system, and to examine the limits of short-term predictability within these bounds. This approach is especially well suited to the need for short-term predictions to support remediation decisions and long-term bounding studies. View-graphs from ten presentations made at the annual meeting held December 3--4, 1997 are included in an appendix to this report

  8. Conceptual and numerical modeling approach of the Guarani Aquifer System

    Directory of Open Access Journals (Sweden)

    L. Rodríguez

    2013-01-01

    Full Text Available In large aquifers, relevant for their considerable size, regional groundwater modeling remains challenging given geologic complexity and data scarcity in space and time. Yet, it may be conjectured that regional scale groundwater flow models can help in understanding the flow system functioning and the relative magnitude of water budget components, which are important for aquifer management. The Guaraní Aquifer System is the largest transboundary aquifer in South America. It contains an enormous volume of water; however, it is not well known, being difficult to assess the impact of exploitation currently used to supply over 25 million inhabitants. This is a sensitive issue because the aquifer is shared by four countries. Moreover, an integrated groundwater model, and therefore a global water balance, were not available. In this work, a transient regional scale model for the entire aquifer based upon five simplified, equally plausible conceptual models represented by different hydraulic conductivity parametrizations is used to analyze the flow system and water balance components. Combining an increasing number of hydraulic conductivity zones and an appropriate set of boundary conditions, the hypothesis of a continuous sedimentary unit yielded errors within the calibration target in a regional sense. The magnitude of the water budget terms resulted very similar for all parametrizations. Recharge and stream/aquifer fluxes were the dominant components representing, on average, 84.2% of total inflows and 61.4% of total outflows, respectively. However, leakage was small compared to stream discharges of main rivers. For instance, the simulated average leakage for the Uruguay River was 8 m3 s−1 while the observed absolute minimum discharge was 382 m3 s−1. Streams located in heavily pumped regions switched from a gaining condition in early years to a losing condition over time. Water is discharged through

  9. Conceptual and numerical modeling approach of the Guarani Aquifer System

    Science.gov (United States)

    Rodríguez, L.; Vives, L.; Gomez, A.

    2013-01-01

    In large aquifers, relevant for their considerable size, regional groundwater modeling remains challenging given geologic complexity and data scarcity in space and time. Yet, it may be conjectured that regional scale groundwater flow models can help in understanding the flow system functioning and the relative magnitude of water budget components, which are important for aquifer management. The Guaraní Aquifer System is the largest transboundary aquifer in South America. It contains an enormous volume of water; however, it is not well known, being difficult to assess the impact of exploitation currently used to supply over 25 million inhabitants. This is a sensitive issue because the aquifer is shared by four countries. Moreover, an integrated groundwater model, and therefore a global water balance, were not available. In this work, a transient regional scale model for the entire aquifer based upon five simplified, equally plausible conceptual models represented by different hydraulic conductivity parametrizations is used to analyze the flow system and water balance components. Combining an increasing number of hydraulic conductivity zones and an appropriate set of boundary conditions, the hypothesis of a continuous sedimentary unit yielded errors within the calibration target in a regional sense. The magnitude of the water budget terms resulted very similar for all parametrizations. Recharge and stream/aquifer fluxes were the dominant components representing, on average, 84.2% of total inflows and 61.4% of total outflows, respectively. However, leakage was small compared to stream discharges of main rivers. For instance, the simulated average leakage for the Uruguay River was 8 m3 s-1 while the observed absolute minimum discharge was 382 m3 s-1. Streams located in heavily pumped regions switched from a gaining condition in early years to a losing condition over time. Water is discharged through the aquifer boundaries, except at the eastern boundary. On average

  10. A revised conceptual hydrogeologic model of a crystalline rock environment, Whiteshell research area, southeastern Manitoba, Canada

    International Nuclear Information System (INIS)

    Stevenson, D.R.; Brown, A.; Davison, C.C.; Gascoyne, M.; McGregor, R.G.; Ophori, D.U.; Scheier, N.W.; Stanchell, F.; Thorne, G.A.; Tomsons, D.K.

    1996-04-01

    A revised conceptual hydrogeologic model of regional groundwater flow in the crystalline rocks of the Whiteshell Research Area (WRA) has been developed by a team of AECL geoscientists. The revised model updates an earlier model developed in 1985, and has a much broader database. This database was compiled from Landsat and airborne radar images, geophysical surveys and surface mapping, and from analyses of fracture logs, hydraulic tests and water samples collected from a network of deep boreholes drilled across the WRA. The boundaries of the revised conceptual model were selected to coincide with the natural hydraulic boundaries assumed for the regional groundwater flow systems in the WRA. The upper and lower boundaries are the water table and a horizontal plane 4 km below ground surface. For modelling purposes the rocks below 4 km are considered to be impermeable. The rocks of the modelled region were divided on the basis of fracture characteristics into three categories: fractured zones (FZs); moderately fractured rock (MFR); and sparsely fractured rock (SFR). The FZs are regions of intensely fractured rock. Seventy-six FZs were selected to form the fault framework within the revised conceptual model. The physical rock/water properties of the FZs, MFR and SFR were selected by analysis of field data from hydraulic and tracer tests, laboratory test data and water quality data. These properties were used to define a mathematical groundwater flow model of the WRA using AECL's MOTIF finite element code (Ophori et al. 1995, 1996). (author). 29 refs., 4 tabs., 12 figs

  11. A conceptual model for determining career choice of CHROME alumna based on farmer's conceptual models

    Science.gov (United States)

    Moore, Lisa Simmons

    This qualitative program evaluation examines the career decision-making processes and career choices of nine, African American women who participated in the Cooperating Hampton Roads Organization for Minorities in Engineering (CHROME) and who graduated from urban, rural or suburban high schools in the year 2000. The CHROME program is a nonprofit, pre-college intervention program that encourages underrepresented minority and female students to enter science, technically related, engineering, and math (STEM) career fields. The study describes career choices and decisions made by each participant over a five-year period since high school graduation. Data was collected through an Annual Report, Post High School Questionnaires, Environmental Support Questionnaires, Career Choice Questionnaires, Senior Reports, and standardized open-ended interviews. Data was analyzed using a model based on Helen C. Farmer's Conceptual Models, John Ogbu's Caste Theory and Feminist Theory. The CHROME program, based on its stated goals and tenets, was also analyzed against study findings. Findings indicated that participants received very low levels of support from counselors and teachers to pursue STEM careers and high levels of support from parents and family, the CHROME program and financial backing. Findings of this study also indicated that the majority of CHROME alumna persisted in STEM careers. The most successful participants, in terms of undergraduate degree completion and occupational prestige, were the African American women who remained single, experienced no critical incidents, came from a middle class to upper middle class socioeconomic background, and did not have children.

  12. Three-dimensional conceptual model for the Hanford Site unconfined aquifer system, FY 1993 status report

    International Nuclear Information System (INIS)

    Thorne, P.D.; Chamness, M.A.; Spane, F.A. Jr.; Vermeul, V.R.; Webber, W.D.

    1993-12-01

    The ground water underlying parts of the Hanford Site (Figure 1.1) contains radioactive and chemical contaminants at concentrations exceeding regulatory standards (Dresel et al. 1993). The Hanford Site Ground-Water Surveillance Project, operated by Pacific Northwest Laboratory (PNL), is responsible for monitoring the movement of these contaminants to ensure that public health and the environment are protected. To support the monitoring effort, a sitewide three-dimensional ground-water flow model is being developed. This report provides an update on the status of the conceptual model that will form the basis for constructing a numerical three-dimensional flow model for, the site. Thorne and Chamness (1992) provide additional information on the initial development of the three-dimensional conceptual model

  13. Identifying students’ mental models of sound propagation: The role of conceptual blending in understanding conceptual change

    Directory of Open Access Journals (Sweden)

    Zdeslav Hrepic

    2010-09-01

    Full Text Available We investigated introductory physics students’ mental models of sound propagation. We used a phenomenographic method to analyze the data in the study. In addition to the scientifically accepted Wave model, students used the “Entity” model to describe the propagation of sound. In this latter model sound is a self-standing entity, different from the medium through which it propagates. All other observed alternative models contain elements of both Entity and Wave models, but at the same time are distinct from each of the constituent models. We called these models “hybrid” or “blend” models. We discuss how students use these models in various contexts before and after instruction and how our findings contribute to the understanding of conceptual change. Implications of our findings for teaching are summarized.

  14. 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

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

    International Nuclear Information System (INIS)

    Serne, R.J.

    1991-10-01

    Recently several articles have been published that question the appropriateness of the distribution coefficient, Rd, concept to quantify radionuclide migration. Several distinct issues are raised by various critics. In this paper I provide some perspective on 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

  16. Conceptual Modeling of Time-Varying Information

    DEFF Research Database (Denmark)

    Gregersen, Heidi; Jensen, Christian S.

    2004-01-01

    A wide range of database applications manage information that varies over time. Many of the underlying database schemas of these were designed using the Entity-Relationship (ER) model. In the research community as well as in industry, it is common knowledge that the temporal aspects of the mini......-world are important, but difficult to capture using the ER model. Several enhancements to the ER model have been proposed in an attempt to support the modeling of temporal aspects of information. Common to the existing temporally extended ER models, few or no specific requirements to the models were given...

  17. A Conceptual Framework of Business Model Emerging Resilience

    OpenAIRE

    Goumagias, Nik; Fernandes, Kiran; Cabras, Ignazio; Li, Feng; Shao, Jianhao; Devlin, Sam; Hodge, Victoria Jane; Cowling, Peter Ivan; Kudenko, Daniel

    2016-01-01

    In this paper we introduce an environmentally driven conceptual framework of Business Model change. Business models acquired substantial momentum in academic literature during the past decade. Several studies focused on what exactly constitutes a Business Model (role model, recipe, architecture etc.) triggering a theoretical debate about the Business Model’s components and their corresponding dynamics and relationships. In this paper, we argue that for Business Models as cognitive structures,...

  18. Conceptual language models for domain-specific retrieval

    NARCIS (Netherlands)

    Meij, E.; Trieschnigg, D.; de Rijke, M.; Kraaij, W.

    2010-01-01

    Over the years, various meta-languages have been used to manually enrich documents with conceptual knowledge of some kind. Examples include keyword assignment to citations or, more recently, tags to websites. In this paper we propose generative concept models as an extension to query modeling within

  19. River City High School Guidance Services: A Conceptual Model.

    Science.gov (United States)

    American Coll. Testing Program, Iowa City, IA.

    This model describes how the guidance staff at a hypothetical high school communicated the effectiveness of the guidance program to students, parents, teachers, and administrators. A description of the high school is presented, and guidance services and personnel are described. A conceptual model responding to student needs is outlined along with…

  20. Conceptual basis for developing of trainig models in complex ...

    African Journals Online (AJOL)

    This paper presents conceptual basis for developing of training models of interactive assembling system for automatic building of application software systems, ... software generation, such as: program module compatibility, formalization of computer interaction and choosing of formal model for human machine interface.

  1. Regionalising Parameters of a Conceptual Rainfall-Runoff Model for ...

    African Journals Online (AJOL)

    IHACRES, a lumped conceptual rainfall-runoff model, was calibrated to six catchments ranging in size from 49km2 to 600 km2 within the upper Tana River basin to obtain a set of model parameters that characterise the hydrological behaviour within the region. Physical catchment attributes indexing topography, soil and ...

  2. Conceptual Model of Artifacts for Design Science Research

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    2015-01-01

    We present a conceptual model of design science research artifacts. The model views an artifact at three levels. At the artifact level a selected artifact is viewed as a combination of material and immaterial aspects and a set of representations hereof. At the design level the selected artifact...

  3. Menthor Editor: An Ontology-Driven Conceptual Modeling Platform

    NARCIS (Netherlands)

    Moreira, João Luiz; Sales, Tiago Prince; Guerson, John; Braga, Bernardo F.B; Brasileiro, Freddy; Sobral, Vinicius

    2016-01-01

    The lack of well-founded constructs in ontology tools can lead to the construction of non-intended models. In this demonstration we present the Menthor Editor, an ontology-driven conceptual modelling platform which incorporates the theories of the Unified Foundational Ontology (UFO). We illustrate

  4. Virtual Business Collaboration Conceptual Knowledge Model (VBCKM)

    OpenAIRE

    Morcous Massoud Yassa; Fatama A Omara; Hesham A Hassan

    2012-01-01

    Within the context of virtual business collaboration modeling, many pervious works have been accepted to consider some essential virtual business collaborative models. A practical dynamic virtual organization may be a combination of those models and some other elemental features with some modifications to meet the business opportunity requirements. Therefore, some guidelines and rules are needed to help in constructing a practical collaboration model. This work aims to determine the essential...

  5. Comparison of a Conceptual Groundwater Model and Physically Based Groundwater Mode

    Science.gov (United States)

    Yang, J.; Zammit, C.; Griffiths, J.; Moore, C.; Woods, R. A.

    2017-12-01

    Groundwater is a vital resource for human activities including agricultural practice and urban water demand. Hydrologic modelling is an important way to study groundwater recharge, movement and discharge, and its response to both human activity and climate change. To understand the groundwater hydrologic processes nationally in New Zealand, we have developed a conceptually based groundwater flow model, which is fully integrated into a national surface-water model (TopNet), and able to simulate groundwater recharge, movement, and interaction with surface water. To demonstrate the capability of this groundwater model (TopNet-GW), we applied the model to an irrigated area with water shortage and pollution problems in the upper Ruamahanga catchment in Great Wellington Region, New Zealand, and compared its performance with a physically-based groundwater model (MODFLOW). The comparison includes river flow at flow gauging sites, and interaction between groundwater and river. Results showed that the TopNet-GW produced similar flow and groundwater interaction patterns as the MODFLOW model, but took less computation time. This shows the conceptually-based groundwater model has the potential to simulate national groundwater process, and could be used as a surrogate for the more physically based model.

  6. Motivation to Improve Work through Learning: A Conceptual Model

    Directory of Open Access Journals (Sweden)

    Kueh Hua Ng

    2014-12-01

    Full Text Available This study aims to enhance our current understanding of the transfer of training by proposing a conceptual model that supports the mediating role of motivation to improve work through learning about the relationship between social support and the transfer of training. The examination of motivation to improve work through motivation to improve work through a learning construct offers a holistic view pertaining to a learner's profile in a workplace setting, which emphasizes learning for the improvement of work performance. The proposed conceptual model is expected to benefit human resource development theory building, as well as field practitioners by emphasizing the motivational aspects crucial for successful transfer of training.

  7. Hydrogeological conceptual model development and numerical modelling using CONNECTFLOW, Forsmark modelling stage 2.3

    Energy Technology Data Exchange (ETDEWEB)

    Follin, Sven (SF GeoLogic AB, Taeby (Sweden)); Hartley, Lee; Jackson, Peter; Roberts, David (Serco TAP (United Kingdom)); Marsic, Niko (Kemakta Konsult AB, Stockholm (Sweden))

    2008-05-15

    of spatial variability of the hydraulic properties within soil layers and horizontal versus vertical anisotropy in the hydraulic conductivity of soils. For the deformation zones, the same prescription for assigning transmissivities was followed as for stage 2.2, but a new method for automating the local conditioning of the deformation zone transmissivity in the vicinity of a measurement interval was used. The numerical simulations carried out in stage 2.2 demonstrated that the three geological units: deformation zones, fracture domains and regolith, can be parameterised by means of single-hole hydraulic tests and satisfactorily transformed into heterogeneous hydraulic conductor domains (HCD), hydraulic rock mass domains (HRD) and hydraulic soil domains (HSD). This means that the conceptual model developed from the interpretation of Forsmark data in stage 2.2 can be used to predict a wide range of different types of data and processes such as 1) large-scale cross-hole test responses, 2) natural point-water heads in the bedrock and the regolith, and 3) hydrochemistry profiles along the many cored boreholes drilled in close proximity to the so called target area. It is noted that a primary idea of the confirmatory testing applied in stage 2.2 is that the same groundwater flow and solute transport model is used for each type of simulation to make it transparent that a single implementation of the conceptual model could be calibrated against all three types of field observations, although it may have been possible to improve the modelling of a particular data type by refining the model around a relevant observation borehole, for example. The conceptual modelling in stage 2.2 invoked a number of hypotheses, three of which that were addressed in stage 2.3 by means of complementary field investigations (hydraulic tests). The results from these investigations do not falsify (contradict) any of the three hypotheses, hence none of them should be rejected. In fact, the three

  8. A Conceptual Model for Leadership Transition

    Science.gov (United States)

    Manderscheid, Steven V.; Ardichvili, Alexandre

    2008-01-01

    The purpose of this study was to develop a model of leadership transition based on an integrative review of literature. The article establishes a compelling case for focusing on leadership transitions as an area for study and leadership development practitioner intervention. The proposed model in this study identifies important success factors…

  9. Balance between calibration objectives in a conceptual hydrological model

    NARCIS (Netherlands)

    Booij, Martijn J.; Krol, Martinus S.

    2010-01-01

    Three different measures to determine the optimum balance between calibration objectives are compared: the combined rank method, parameter identifiability and model validation. Four objectives (water balance, hydrograph shape, high flows, low flows) are included in each measure. The contributions of

  10. The ACTIVE conceptual framework as a structural equation model

    Science.gov (United States)

    Gross, Alden L.; Payne, Brennan R.; Casanova, Ramon; Davoudzadeh, Pega; Dzierzewski, Joseph M.; Farias, Sarah; Giovannetti, Tania; Ip, Edward H.; Marsiske, Michael; Rebok, George W.; Schaie, K. Warner; Thomas, Kelsey; Willis, Sherry; Jones, Richard N.

    2018-01-01

    Background/Study Context Conceptual frameworks are analytic models at a high level of abstraction. Their operationalization can inform randomized trial design and sample size considerations. Methods The Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) conceptual framework was empirically tested using structural equation modeling (N=2,802). ACTIVE was guided by a conceptual framework for cognitive training in which proximal cognitive abilities (memory, inductive reasoning, speed of processing) mediate treatment-related improvement in primary outcomes (everyday problem-solving, difficulty with activities of daily living, everyday speed, driving difficulty), which in turn lead to improved secondary outcomes (health-related quality of life, health service utilization, mobility). Measurement models for each proximal, primary, and secondary outcome were developed and tested using baseline data. Each construct was then combined in one model to evaluate fit (RMSEA, CFI, normalized residuals of each indicator). To expand the conceptual model and potentially inform future trials, evidence of modification of structural model parameters was evaluated by age, years of education, sex, race, and self-rated health status. Results Preconceived measurement models for memory, reasoning, speed of processing, everyday problem-solving, instrumental activities of daily living (IADL) difficulty, everyday speed, driving difficulty, and health-related quality of life each fit well to the data (all RMSEA .95). Fit of the full model was excellent (RMSEA = .038; CFI = .924). In contrast with previous findings from ACTIVE regarding who benefits from training, interaction testing revealed associations between proximal abilities and primary outcomes are stronger on average by nonwhite race, worse health, older age, and less education (p conceptual model. Findings suggest that the types of people who show intervention effects on cognitive performance potentially may be

  11. The ACTIVE conceptual framework as a structural equation model.

    Science.gov (United States)

    Gross, Alden L; Payne, Brennan R; Casanova, Ramon; Davoudzadeh, Pega; Dzierzewski, Joseph M; Farias, Sarah; Giovannetti, Tania; Ip, Edward H; Marsiske, Michael; Rebok, George W; Schaie, K Warner; Thomas, Kelsey; Willis, Sherry; Jones, Richard N

    2018-01-01

    Background/Study Context: Conceptual frameworks are analytic models at a high level of abstraction. Their operationalization can inform randomized trial design and sample size considerations. The Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) conceptual framework was empirically tested using structural equation modeling (N=2,802). ACTIVE was guided by a conceptual framework for cognitive training in which proximal cognitive abilities (memory, inductive reasoning, speed of processing) mediate treatment-related improvement in primary outcomes (everyday problem-solving, difficulty with activities of daily living, everyday speed, driving difficulty), which in turn lead to improved secondary outcomes (health-related quality of life, health service utilization, mobility). Measurement models for each proximal, primary, and secondary outcome were developed and tested using baseline data. Each construct was then combined in one model to evaluate fit (RMSEA, CFI, normalized residuals of each indicator). To expand the conceptual model and potentially inform future trials, evidence of modification of structural model parameters was evaluated by age, years of education, sex, race, and self-rated health status. Preconceived measurement models for memory, reasoning, speed of processing, everyday problem-solving, instrumental activities of daily living (IADL) difficulty, everyday speed, driving difficulty, and health-related quality of life each fit well to the data (all RMSEA .95). Fit of the full model was excellent (RMSEA = .038; CFI = .924). In contrast with previous findings from ACTIVE regarding who benefits from training, interaction testing revealed associations between proximal abilities and primary outcomes are stronger on average by nonwhite race, worse health, older age, and less education (p conceptual model. Findings suggest that the types of people who show intervention effects on cognitive performance potentially may be different from

  12. Conceptual design of the test facility for the two-phase critical flow with non-condensable gas

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Seok Kyu; Chung, Chang Hwan

    2000-12-01

    The two-phase critical flow test with non-condensible gas is for the simulation of the critical flow phenomena which can be occurred during SB-LOCA on SMART reactor. The requirements of the critical flow test are 7{approx}20mm pipe break dia., 7{approx}12MPa stagnation pressure, 0{approx}60 deg C subcooling degree and 0{approx}0.5kg/s N2 gas flow rate. For the satisfaction of these requirements on the test facility, critical flow rates were calculated with various models. With the selected reference pressure vessel(1.3m{sup 3}), the conceptual design of the test facility was performed. The important components of the test facility are the pressure vessel which has main circulation line, the test section attached to the bottom of the pressure vessel, suppression tank, the N2 gas supply tanks for maintaining the system pressure and N2 gas flow rate at test section and the auxiliary N2 gas converting system. For the measurements of the critical flow rate, flowmeter and level gauge is installed at the upstream of the test section and the pressure vessel, respectively. The realtime pressure control system is installed at the entrance of the pressure vessel for maintaining the system pressure and the N2 gas flow regulating system is also installed at the upstream of the test section. The design of the control and monitoring system for the operation of the test facility and the DAS for acquiring the test data were also performed. The conceptual operating process of the test facility was determined.

  13. Conceptual design of the test facility for the two-phase critical flow with non-condensable gas

    International Nuclear Information System (INIS)

    Chang, Seok Kyu; Chung, Chang Hwan

    2000-12-01

    The two-phase critical flow test with non-condensible gas is for the simulation of the critical flow phenomena which can be occurred during SB-LOCA on SMART reactor. The requirements of the critical flow test are 7∼20mm pipe break dia., 7∼12MPa stagnation pressure, 0∼60 deg C subcooling degree and 0∼0.5kg/s N2 gas flow rate. For the satisfaction of these requirements on the test facility, critical flow rates were calculated with various models. With the selected reference pressure vessel(1.3m 3 ), the conceptual design of the test facility was performed. The important components of the test facility are the pressure vessel which has main circulation line, the test section attached to the bottom of the pressure vessel, suppression tank, the N2 gas supply tanks for maintaining the system pressure and N2 gas flow rate at test section and the auxiliary N2 gas converting system. For the measurements of the critical flow rate, flowmeter and level gauge is installed at the upstream of the test section and the pressure vessel, respectively. The realtime pressure control system is installed at the entrance of the pressure vessel for maintaining the system pressure and the N2 gas flow regulating system is also installed at the upstream of the test section. The design of the control and monitoring system for the operation of the test facility and the DAS for acquiring the test data were also performed. The conceptual operating process of the test facility was determined

  14. Multilevel Models: Conceptual Framework and Applicability

    Directory of Open Access Journals (Sweden)

    Roxana-Otilia-Sonia Hrițcu

    2015-10-01

    Full Text Available Individuals and the social or organizational groups they belong to can be viewed as a hierarchical system situated on different levels. Individuals are situated on the first level of the hierarchy and they are nested together on the higher levels. Individuals interact with the social groups they belong to and are influenced by these groups. Traditional methods that study the relationships between data, like simple regression, do not take into account the hierarchical structure of the data and the effects of a group membership and, hence, results may be invalidated. Unlike standard regression modelling, the multilevel approach takes into account the individuals as well as the groups to which they belong. To take advantage of the multilevel analysis it is important that we recognize the multilevel characteristics of the data. In this article we introduce the outlines of multilevel data and we describe the models that work with such data. We introduce the basic multilevel model, the two-level model: students can be nested into classes, individuals into countries and the general two-level model can be extended very easily to several levels. Multilevel analysis has begun to be extensively used in many research areas. We present the most frequent study areas where multilevel models are used, such as sociological studies, education, psychological research, health studies, demography, epidemiology, biology, environmental studies and entrepreneurship. We support the idea that since hierarchies exist everywhere, multilevel data should be recognized and analyzed properly by using multilevel modelling.

  15. UZ Flow Models and Submodels

    International Nuclear Information System (INIS)

    Y. Wu

    2004-01-01

    The purpose of this report is to document the unsaturated zone (UZ) flow models and submodels, as well as the flow fields that have been generated using the UZ flow model(s) of Yucca Mountain, Nevada. In this report, the term ''UZ model'' refers to the UZ flow model and the several submodels, which include tracer transport, temperature or ambient geothermal, pneumatic or gas flow, and geochemistry (chloride, calcite, and strontium) submodels. The term UZ flow model refers to the three-dimensional models used for calibration and simulation of UZ flow fields. This work was planned in the ''Technical Work Plan (TWP) for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.7). The table of included Features, Events, and Processes (FEPs), Table 6.2-11, is different from the list of included FEPs assigned to this report in the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Table 2.1.5-1), as discussed in Section 6.2.6. The UZ model has revised, updated, and enhanced the previous UZ model (BSC 2001 [DIRS 158726]) by incorporating the repository design with new grids, recalibration of property sets, and more comprehensive validation effort. The flow fields describe fracture-fracture, matrix-matrix, and fracture-matrix liquid flow rates, and their spatial distributions as well as moisture conditions in the UZ system. These three-dimensional UZ flow fields are used directly by Total System Performance Assessment (TSPA). The model and submodels evaluate important hydrogeologic processes in the UZ as well as geochemistry and geothermal conditions. These provide the necessary framework to test hypotheses of flow and transport at different scales, and predict flow and transport behavior under a variety of climatic conditions. In addition, the limitations of the UZ model are discussed in Section 8.11

  16. Modelling students' knowledge organisation: Genealogical conceptual networks

    Science.gov (United States)

    Koponen, Ismo T.; Nousiainen, Maija

    2018-04-01

    Learning scientific knowledge is largely based on understanding what are its key concepts and how they are related. The relational structure of concepts also affects how concepts are introduced in teaching scientific knowledge. We model here how students organise their knowledge when they represent their understanding of how physics concepts are related. The model is based on assumptions that students use simple basic linking-motifs in introducing new concepts and mostly relate them to concepts that were introduced a few steps earlier, i.e. following a genealogical ordering. The resulting genealogical networks have relatively high local clustering coefficients of nodes but otherwise resemble networks obtained with an identical degree distribution of nodes but with random linking between them (i.e. the configuration-model). However, a few key nodes having a special structural role emerge and these nodes have a higher than average communicability betweenness centralities. These features agree with the empirically found properties of students' concept networks.

  17. A Conceptualized Investment Model of Crowdfunding

    DEFF Research Database (Denmark)

    Tomczak, A.; Brem, Alexander

    2013-01-01

    Crowdfunding is growing in popularity as a new form of both investment opportunity and source of venture capital. This article takes a view on whether crowdfunding is a replacement or an addition to traditional seed capital sources in the early stages of a new venture. With access to angel...... investment decreasing since the financial crisis of 2008, crowdfunding is of great importance to start-ups seeking starting capital. However, little effort has been made to define the investment model of crowdfunding with both crowdfunder and crowdfundee in mind. Drawing on an in-depth review of current...... literature on crowdfunding, this article creates an investment model of crowdfunding with various reward models available to investor and investee in mind. This article provides an extensive survey of the environment of crowdfunding based on current literature. It offers a jumping off point and a thorough...

  18. A Conceptual Model of Investor Behavior

    NARCIS (Netherlands)

    M. Lovric (Milan); U. Kaymak (Uzay); J. Spronk (Jaap)

    2008-01-01

    textabstractBased on a survey of behavioral finance literature, this paper presents a descriptive model of individual investor behavior in which investment decisions are seen as an iterative process of interactions between the investor and the investment environment. This investment process is

  19. A conceptual model of investor behavior

    NARCIS (Netherlands)

    Lovric, M.; Kaymak, U.; Spronk, J.; Nefti, S.; Gray, J.O.

    2010-01-01

    Behavioral finance is a subdiscipline of finance that uses insights from cogni tive and social psychology to enrich our knowledge of how investors make their financial decisions. Agent-based artificial financial markets are bottomup models of financial markets that start from the micro level of

  20. Learning strategies: a synthesis and conceptual model

    Science.gov (United States)

    Hattie, John A. C.; Donoghue, Gregory M.

    2016-08-01

    The purpose of this article is to explore a model of learning that proposes that various learning strategies are powerful at certain stages in the learning cycle. The model describes three inputs and outcomes (skill, will and thrill), success criteria, three phases of learning (surface, deep and transfer) and an acquiring and consolidation phase within each of the surface and deep phases. A synthesis of 228 meta-analyses led to the identification of the most effective strategies. The results indicate that there is a subset of strategies that are effective, but this effectiveness depends on the phase of the model in which they are implemented. Further, it is best not to run separate sessions on learning strategies but to embed the various strategies within the content of the subject, to be clearer about developing both surface and deep learning, and promoting their associated optimal strategies and to teach the skills of transfer of learning. The article concludes with a discussion of questions raised by the model that need further research.

  1. Developing rural palliative care: validating a conceptual model.

    Science.gov (United States)

    Kelley, Mary Lou; Williams, Allison; DeMiglio, Lily; Mettam, Hilary

    2011-01-01

    The purpose of this research was to validate a conceptual model for developing palliative care in rural communities. This model articulates how local rural healthcare providers develop palliative care services according to four sequential phases. The model has roots in concepts of community capacity development, evolves from collaborative, generalist rural practice, and utilizes existing health services infrastructure. It addresses how rural providers manage challenges, specifically those related to: lack of resources, minimal community understanding of palliative care, health professionals' resistance, the bureaucracy of the health system, and the obstacles of providing services in rural environments. Seven semi-structured focus groups were conducted with interdisciplinary health providers in 7 rural communities in two Canadian provinces. Using a constant comparative analysis approach, focus group data were analyzed by examining participants' statements in relation to the model and comparing emerging themes in the development of rural palliative care to the elements of the model. The data validated the conceptual model as the model was able to theoretically predict and explain the experiences of the 7 rural communities that participated in the study. New emerging themes from the data elaborated existing elements in the model and informed the requirement for minor revisions. The model was validated and slightly revised, as suggested by the data. The model was confirmed as being a useful theoretical tool for conceptualizing the development of rural palliative care that is applicable in diverse rural communities.

  2. A conceptual model specification language (CMSL Version 2)

    NARCIS (Netherlands)

    Wieringa, Roelf J.

    1992-01-01

    Version 2 of a language (CMSL) to specify conceptual models is defined. CMSL consists of two parts, the value specification language VSL and the object spercification language OSL. There is a formal semantics and an inference system for CMSL but research on this still continues. A method for

  3. Conceptual model for reinforced grass on inner dike slopes

    NARCIS (Netherlands)

    Verhagen, H.J.; ComCoast

    2005-01-01

    A desk study has been carried out in order to develop a conceptual model for the erosion of inner dike slopes with reinforced grass cover. Based on the results the following can be concluded: The presence of a geosynthetic in a grass slope can be taken into account in the EPM method by increasing

  4. LCM 3.0: A Language for describing Conceptual Models

    NARCIS (Netherlands)

    Feenstra, Remco; Wieringa, Roelf J.

    1993-01-01

    The syntax of the conceptual model specification language LCM is defined. LCM uses equational logic to specify data types and order-sorted dynamic logic to specify objects with identity and mutable state. LCM specifies database transactions as finite sets of atomic object transitions.

  5. A New Conceptual Model for Understanding International Students' College Needs

    Science.gov (United States)

    Alfattal, Eyad

    2016-01-01

    This study concerns the theory and practice of international marketing in higher education with the purpose of exploring a conceptual model for understanding international students' needs in the context of a four-year college in the United States. A transcendental phenomenological design was employed to investigate the essence of international…

  6. Designing Public Library Websites for Teens: A Conceptual Model

    Science.gov (United States)

    Naughton, Robin Amanda

    2012-01-01

    The main goal of this research study was to develop a conceptual model for the design of public library websites for teens (TLWs) that would enable designers and librarians to create library websites that better suit teens' information needs and practices. It bridges a gap in the research literature between user interface design in human-computer…

  7. A Conceptual Model of the World of Work.

    Science.gov (United States)

    VanRooy, William H.

    The conceptual model described in this paper resulted from the need to organize a body of knowledge related to the world of work which would enable curriculum developers to prepare accurate, realistic instructional materials. The world of work is described by applying Malinowski's scientific study of the structural components of culture. It is…

  8. Conceptual models for waste tank mechanistic analysis

    International Nuclear Information System (INIS)

    Allemann, R.T.; Antoniak, Z.I.; Eyler, L.L.; Liljegren, L.M.; Roberts, J.S.

    1992-02-01

    Pacific Northwest Laboratory (PNL) is conducting a study for Westinghouse Hanford Company (Westinghouse Hanford), a contractor for the US Department of Energy (DOE). The purpose of the work is to study possible mechanisms and fluid dynamics contributing to the periodic release of gases from double-shell waste storage tanks at the Hanford Site in Richland, Washington. This interim report emphasizing the modeling work follows two other interim reports, Mechanistic Analysis of Double-Shell Tank Gas Release Progress Report -- November 1990 and Collection and Analysis of Existing Data for Waste Tank Mechanistic Analysis Progress Report -- December 1990, that emphasized data correlation and mechanisms. The approach in this study has been to assemble and compile data that are pertinent to the mechanisms, analyze the data, evaluate physical properties and parameters, evaluate hypothetical mechanisms, and develop mathematical models of mechanisms

  9. A Conceptual Model of Investor Behavior

    OpenAIRE

    Lovric, M.; Kaymak, U.; Spronk, J.

    2008-01-01

    textabstractBased on a survey of behavioral finance literature, this paper presents a descriptive model of individual investor behavior in which investment decisions are seen as an iterative process of interactions between the investor and the investment environment. This investment process is influenced by a number of interdependent variables and driven by dual mental systems, the interplay of which contributes to boundedly rational behavior where investors use various heuristics and may exh...

  10. Conceptual model of integrated apiarian consultancy

    OpenAIRE

    Bodescu, Dan; Stefan, Gavril; Paveliuc Olariu, Codrin; Magdici, Maria

    2010-01-01

    The socio-economic field researches have indicated the necessity of realizing an integrated consultancy service for beekeepers that will supply technical-economic solutions with a practical character for ensuring the lucrativeness and viability of the apiaries. Consequently, an integrated apiarian consultancy model has been built holding the following features: it realizes the diagnosis of the meliferous resources and supplies solutions for its optimal administration; it realizes the technica...

  11. Conceptual model of water resources in the Kabul Basin, Afghanistan

    Science.gov (United States)

    Mack, Thomas J.; Akbari, M. Amin; Ashoor, M. Hanif; Chornack, Michael P.; Coplen, Tyler B.; Emerson, Douglas G.; Hubbard, Bernard E.; Litke, David W.; Michel, Robert L.; Plummer, Niel; Rezai, M. Taher; Senay, Gabriel B.; Verdin, James P.; Verstraeten, Ingrid M.

    2010-01-01

    The United States (U.S.) Geological Survey has been working with the Afghanistan Geological Survey and the Afghanistan Ministry of Energy and Water on water-resources investigations in the Kabul Basin under an agreement supported by the United States Agency for International Development. This collaborative investigation compiled, to the extent possible in a war-stricken country, a varied hydrogeologic data set and developed limited data-collection networks to assist with the management of water resources in the Kabul Basin. This report presents the results of a multidisciplinary water-resources assessment conducted between 2005 and 2007 to address questions of future water availability for a growing population and of the potential effects of climate change. Most hydrologic and climatic data-collection activities in Afghanistan were interrupted in the early 1980s as a consequence of war and civil strife and did not resume until 2003 or later. Because of the gap of more than 20 years in the record of hydrologic and climatic observations, this investigation has made considerable use of remotely sensed data and, where available, historical records to investigate the water resources of the Kabul Basin. Specifically, this investigation integrated recently acquired remotely sensed data and satellite imagery, including glacier and climatic data; recent climate-change analyses; recent geologic investigations; analysis of streamflow data; groundwater-level analysis; surface-water- and groundwater-quality data, including data on chemical and isotopic environmental tracers; and estimates of public-supply and agricultural water uses. The data and analyses were integrated by using a simplified groundwater-flow model to test the conceptual model of the hydrologic system and to assess current (2007) and future (2057) water availability. Recharge in the basin is spatially and temporally variable and generally occurs near streams and irrigated areas in the late winter and early

  12. Wound care clinical pathway: a conceptual model.

    Science.gov (United States)

    Barr, J E; Cuzzell, J

    1996-08-01

    A clinical pathway is a written sequence of clinical processes or events that guides a patient with a defined problem toward an expected outcome. Clinical pathways are tools to assist with the cost-effective management of clinical outcomes related to specific problems or disease processes. The primary obstacles to developing clinical pathways for wound care are the chronic natures of some wounds and the many variables that can delay healing. The pathway introduced in this article was modeled upon the three phases of tissue repair: inflammatory, proliferative, and maturation. This physiology-based model allows clinicians to identify and monitor outcomes based on observable and measurable clinical parameters. The pathway design, which also includes educational and behavioral outcomes, allows the clinician to individualize the expected timeframe for outcome achievement based on individual patient criteria and expert judgement. Integral to the pathway are the "4P's" which help standardize the clinical processes by wound type: Protocols, Policies, Procedures, and Patient education tools. Four categories into which variances are categorized based on the cause of the deviation from the norm are patient, process/system, practitioner, and planning/discharge. Additional research is warranted to support the value of this clinical pathway in the clinical arena.

  13. Conceptual design interpretations, mindset and models

    CERN Document Server

    Andreasen, Mogens Myrup; Cash, Philip

    2015-01-01

    Maximising reader insights into the theory, models, methods and fundamental reasoning of design, this book addresses design activities in industrial settings, as well as the actors involved. This approach offers readers a new understanding of design activities and related functions, properties and dispositions. Presenting a ‘design mindset’ that seeks to empower students, researchers, and practitioners alike, it features a strong focus on how designers create new concepts to be developed into products, and how they generate new business and satisfy human needs.   Employing a multi-faceted perspective, the book supplies the reader with a comprehensive worldview of design in the form of a proposed model that will empower their activities as student, researcher or practitioner. We draw the reader into the core role of design conceptualisation for society, for the development of industry, for users and buyers of products, and for citizens in relation to public systems. The book also features original con...

  14. Conceptual Models as Tools for Communication Across Disciplines

    Directory of Open Access Journals (Sweden)

    Marieke Heemskerk

    2003-12-01

    Full Text Available To better understand and manage complex social-ecological systems, social scientists and ecologists must collaborate. However, issues related to language and research approaches can make it hard for researchers in different fields to work together. This paper suggests that researchers can improve interdisciplinary science through the use of conceptual models as a communication tool. The authors share lessons from a workshop in which interdisciplinary teams of young scientists developed conceptual models of social-ecological systems using data sets and metadata from Long-Term Ecological Research sites across the United States. Both the process of model building and the models that were created are discussed. The exercise revealed that the presence of social scientists in a group influenced the place and role of people in the models. This finding suggests that the participation of both ecologists and social scientists in the early stages of project development may produce better questions and more accurate models of interactions between humans and ecosystems. Although the participants agreed that a better understanding of human intentions and behavior would advance ecosystem science, they felt that interdisciplinary research might gain more by training strong disciplinarians than by merging ecology and social sciences into a new field. It is concluded that conceptual models can provide an inspiring point of departure and a guiding principle for interdisciplinary group discussions. Jointly developing a model not only helped the participants to formulate questions, clarify system boundaries, and identify gaps in existing data, but also revealed the thoughts and assumptions of fellow scientists. Although the use of conceptual models will not serve all purposes, the process of model building can help scientists, policy makers, and resource managers discuss applied problems and theory among themselves and with those in other areas.

  15. Two-phase flow models

    International Nuclear Information System (INIS)

    Delaje, Dzh.

    1984-01-01

    General hypothesis used to simplify the equations, describing two-phase flows, are considered. Two-component and one-component models of two-phase flow, as well as Zuber and Findlay model for actual volumetric steam content, and Wallis model, describing the given phase rates, are presented. The conclusion is made, that the two-component model, in which values averaged in time are included, is applicable for the solving of three-dimensional tasks for unsteady two-phase flow. At the same time, using the two-component model, including values, averaged in space only one-dimensional tasks for unsteady two-phase flow can be solved

  16. Conceptual model innovation management: market orientation

    Directory of Open Access Journals (Sweden)

    L.Ya. Maljuta

    2015-06-01

    Full Text Available The article highlights issues that determine the beginning of the innovation process. Determined that until recently in Ukraine at all levels of innovation management (regional, sectoral, institutional dominated grocery orientation innovation that focus on production innovation and found that the transition to a market economy, the restructuring of production and complexity of social needs led to the strengthening of the consumer. It is proved that innovation itself – not the ultimate goal, but only a means of satisfying consumer needs. It proved that changing production conditions, complications of social needs and the need to improve the competitiveness of innovations require finding new forms of innovation. In this regard, proposed to allocate such basic scheme (model of innovation in small businesses, individual entrepreneurs, venture capital firms, eksplerents, patients, violents and commutants, spin-offs and spin-out company, network (or shell company and a network of small businesses.

  17. Collaborative Rural Healthcare Network: A Conceptual Model

    Directory of Open Access Journals (Sweden)

    U. Raja

    2011-07-01

    Full Text Available Healthcare is a critical issue in rural communities throughout the world. Provision of timely and cost effective health care in these communities is a challenge since it is coupled with a lack of adequate infrastructure and manpower support. Twenty percent of the United States of America‘s population resides in rural communities, i.e., 59 million people; however, only nine percent of the nation’s physicians practice in rural communities. Shortage of health care personnel and the lack of equipment and facilities often force rural residents to travel long distances to receive needed medical treatment. Researchers and practitioners are in search of solutions to address these unique challenges. In this research, we present a proposed collaborative model of a health information system for rural communities and the challenges and opportunities of this global issue.

  18. Conceptual model of male military sexual trauma.

    Science.gov (United States)

    Elder, William B; Domino, Jessica L; Rentz, Timothy O; Mata-Galán, Emma L

    2017-08-01

    Male sexual trauma is understudied, leaving much to be known about the unique mental health needs of male survivors. This study examined veteran men's perceptions of the effects of military sexual trauma. Military sexual trauma was defined as physically forced, verbally coerced, or substance-incapacitated acts experienced during military service. Interviews were conducted with 21 male veterans who reported experiencing military sexual trauma. Data were drawn together using a grounded theory methodology. Three categories emerged from data analysis, including (a) types of military sexual trauma (being touched in a sexual way against their will [N = 18]; sexual remarks directed at them [N = 15]; being physically forced to have sex [N = 13]); (b) negative life effects (difficulty trusting others [N = 18]; fear of abandonment [N = 17]; substance use [N = 13]; fear of interpersonal violence [N = 12]; conduct and vocational problems [N = 11]; irritability/aggression [N = 8]; insecurity about sexual performance [N = 8]; difficulty managing anger [N = 8]); and (c) posttraumatic growth (N = 15). Results from this study suggest sexual trauma in the military context may affect systems of self-organization, specifically problems in affective, self-concept, and relational domains, similar to symptoms of those who have experienced prolonged traumatic stressors. This model can be used by clinicians to select treatments that specifically target these symptoms and promote posttraumatic growth. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  19. Tumor heterogeneity and progression: conceptual foundations for modeling.

    Science.gov (United States)

    Greller, L D; Tobin, F L; Poste, G

    1996-01-01

    A conceptual foundation for modeling tumor progression, growth, and heterogeneity is presented. The purpose of such models is to aid understanding, test ideas, formulate experiments, and to model cancer 'in machina' to address the dynamic features of tumor cell heterogeneity, progression, and growth. The descriptive capabilities of such an approach provides a consistent language for qualitatively reasoning about tumor behavior. This approach provides a schema for building conceptual models that combine three key phenomenological driving elements: growth, progression, and genetic instability. The growth element encompasses processes contributing to changes in tumor bulk and is distinct from progression per se. The progression element subsumes a broad collection of processes underlying phenotypic progression. The genetics elements represents heritable changes which potentially affect tumor character and behavior. Models, conceptual and mathematical, can be built for different tumor situations by drawing upon the interaction of these three distinct driving elements. These models can be used as tools to explore a diversity of hypotheses concerning dynamic changes in cellular populations during tumor progression, including the generation of intratumor heterogeneity. Such models can also serve to guide experimentation and to gain insight into dynamic aspects of complex tumor behavior.

  20. BIM-enabled Conceptual Modelling and Representation of Building Circulation

    OpenAIRE

    Lee, Jin Kook; Kim, Mi Jeong

    2014-01-01

    This paper describes how a building information modelling (BIM)-based approach for building circulation enables us to change the process of building design in terms of its computational representation and processes, focusing on the conceptual modelling and representation of circulation within buildings. BIM has been designed for use by several BIM authoring tools, in particular with the widely known interoperable industry foundation classes (IFCs), which follow an object-oriented data modelli...

  1. Advertisement Effectiveness for Print Media: A Conceptual Model

    OpenAIRE

    Prateek Maheshwari; Nitin Seth; Anoop Kumar Gupta

    2015-01-01

    The objective of present research paper is to highlight the importance of measuring advertisement effectiveness in print media and to develop a conceptual model for advertisement effectiveness. The developed model is based on dimensions on which advertisement effectiveness depends and on the dimensions which are used to measure the effectiveness. An in-depth and extensive literature review is carried out to understand the concept of advertisement effectiveness and its var...

  2. A conceptual framework for measuring airline business model convergence

    OpenAIRE

    Daft, Jost; Albers, Sascha

    2012-01-01

    This paper develops a measurement framework that synthesizes the airline and strategy literature to identify relevant dimensions and elements of airline business models. The applicability of this framework for describing airline strategies and structures and, based on this conceptualization, for assessing the potential convergence of airline business models over time is then illustrated using a small sample of five German passenger airlines. For this sample, the perception of a rapprochement ...

  3. Conceptual model elaboration for the safety assessment of phosphogypsum use in sanitary landfills

    International Nuclear Information System (INIS)

    Cota, Stela D.; Braga, Leticia T.P.; Jacomino, Vanusa F.

    2009-01-01

    Phosphogypsum is a by-product of the phosphatic fertilizer production from the beneficiation of phosphate minerals (apatites). Produced in large quantities throughout the world and stored temporally in stacks, the final destination of this product is nowadays a subject of investigation. Due to the presence of radionuclides ( 226 Ra, 232 Th and 40 K, mainly), possible applications for the phosphogypsum must be verified for radiological safety. The goal of this paper was to elaborate a representative water flow conceptual model of a sanitary landfill for the safety assessment of the impact of using phosphogypsum as a cover material. For this, the ground water flow in variably saturated conditions and solute transport model HYDRUS-2D has been used for simulating the impact in the saturated zone of potential radionuclides leaching. The conceptual model was developed by collecting and analyzing the data from environmental license documentation of municipal sanitary landfills located on the State of Minas Gerais, Brazil. In order to fulfill the requirements of HDRUS-2D model in terms of the necessary parameters, the physical characteristics and typical configuration of the landfills, as well as the hydrogeological parameters of soils and aquifers related to the local of placement of the landfills, were taken in account for the formulation of the conceptual model. (author)

  4. Elements of a flexible approach for conceptual hydrological modeling : 1. Motivation and theoretical development

    NARCIS (Netherlands)

    Fenicia, F.; Kavetski, D.; Savenije, H.H.G.

    2011-01-01

    This paper introduces a flexible framework for conceptual hydrological modeling, with two related objectives: (1) generalize and systematize the currently fragmented field of conceptual models and (2) provide a robust platform for understanding and modeling hydrological systems. In contrast to

  5. Investigating conceptual models for physical property couplings in solid solution models of cement

    International Nuclear Information System (INIS)

    Benbow, Steven; Watson, Claire; Savage, David

    2005-11-01

    The long-term behaviour of cementitious engineered barriers is an important process to consider when modelling the migration of radionuclides from a geological repository for nuclear waste. The modelling of cement is complicated by the fact that the cement is dominated by the behaviour of calcium silicate hydrate (CSH) gel which is a complex solid exhibiting incongruent dissolution behaviour. In this report, we have demonstrated the implementation of a solid-solution CSH gel model within a geochemical transport modelling framework using the Raiden computer code to investigate cement/concrete-groundwater interactions. The modelling conducted here shows that it is possible to couple various conceptual models for the evolution of physical properties of concrete with a solid solution model for cement degradation in a fully coupled geochemical transport model to describe the interaction of cement/concrete engineered barriers with groundwater. The results show that changes to the conceptual models and flow rates can give rise to very different evolutions. Most simulations were carried out at a reduced 'experimental' scale rather than full repository scale. The work has shown the possibility to investigate also the changing physical properties of degrading cement. To further develop the model more emphasis is needed on kinetics and the detailed development of a nearly clogged pore space. Modelling of the full repository scale could be another way forward to understand the behaviour of degrading concrete. A general conclusion is that the combined effects of chemical evolution and physical degradation should be analysed in performance assessments of cementitious repositories. Moreover, the project results will be used as one basis in coming reviews of SKB's safety assessments of repositories for spent fuel and low-and intermediate level waste

  6. Investigating conceptual models for physical property couplings in solid solution models of cement

    Energy Technology Data Exchange (ETDEWEB)

    Benbow, Steven; Watson, Claire; Savage, David [Quintesssa Ltd., Henley-on-Thames (United Kingdom)

    2005-11-15

    The long-term behaviour of cementitious engineered barriers is an important process to consider when modelling the migration of radionuclides from a geological repository for nuclear waste. The modelling of cement is complicated by the fact that the cement is dominated by the behaviour of calcium silicate hydrate (CSH) gel which is a complex solid exhibiting incongruent dissolution behaviour. In this report, we have demonstrated the implementation of a solid-solution CSH gel model within a geochemical transport modelling framework using the Raiden computer code to investigate cement/concrete-groundwater interactions. The modelling conducted here shows that it is possible to couple various conceptual models for the evolution of physical properties of concrete with a solid solution model for cement degradation in a fully coupled geochemical transport model to describe the interaction of cement/concrete engineered barriers with groundwater. The results show that changes to the conceptual models and flow rates can give rise to very different evolutions. Most simulations were carried out at a reduced 'experimental' scale rather than full repository scale. The work has shown the possibility to investigate also the changing physical properties of degrading cement. To further develop the model more emphasis is needed on kinetics and the detailed development of a nearly clogged pore space. Modelling of the full repository scale could be another way forward to understand the behaviour of degrading concrete. A general conclusion is that the combined effects of chemical evolution and physical degradation should be analysed in performance assessments of cementitious repositories. Moreover, the project results will be used as one basis in coming reviews of SKB's safety assessments of repositories for spent fuel and low-and intermediate level waste.

  7. Conceptual Commitments of the LIDA Model of Cognition

    Science.gov (United States)

    Franklin, Stan; Strain, Steve; McCall, Ryan; Baars, Bernard

    2013-06-01

    Significant debate on fundamental issues remains in the subfields of cognitive science, including perception, memory, attention, action selection, learning, and others. Psychology, neuroscience, and artificial intelligence each contribute alternative and sometimes conflicting perspectives on the supervening problem of artificial general intelligence (AGI). Current efforts toward a broad-based, systems-level model of minds cannot await theoretical convergence in each of the relevant subfields. Such work therefore requires the formulation of tentative hypotheses, based on current knowledge, that serve to connect cognitive functions into a theoretical framework for the study of the mind. We term such hypotheses "conceptual commitments" and describe the hypotheses underlying one such model, the Learning Intelligent Distribution Agent (LIDA) Model. Our intention is to initiate a discussion among AGI researchers about which conceptual commitments are essential, or particularly useful, toward creating AGI agents.

  8. Modeling of Turbulent Swirling Flows

    Science.gov (United States)

    Shih, Tsan-Hsing; Zhu, Jiang; Liou, William; Chen, Kuo-Huey; Liu, Nan-Suey; Lumley, John L.

    1997-01-01

    Aircraft engine combustors generally involve turbulent swirling flows in order to enhance fuel-air mixing and flame stabilization. It has long been recognized that eddy viscosity turbulence models are unable to appropriately model swirling flows. Therefore, it has been suggested that, for the modeling of these flows, a second order closure scheme should be considered because of its ability in the modeling of rotational and curvature effects. However, this scheme will require solution of many complicated second moment transport equations (six Reynolds stresses plus other scalar fluxes and variances), which is a difficult task for any CFD implementations. Also, this scheme will require a large amount of computer resources for a general combustor swirling flow. This report is devoted to the development of a cubic Reynolds stress-strain model for turbulent swirling flows, and was inspired by the work of Launder's group at UMIST. Using this type of model, one only needs to solve two turbulence equations, one for the turbulent kinetic energy k and the other for the dissipation rate epsilon. The cubic model developed in this report is based on a general Reynolds stress-strain relationship. Two flows have been chosen for model evaluation. One is a fully developed rotating pipe flow, and the other is a more complex flow with swirl and recirculation.

  9. Identification of Chemistry Learning Problems Viewed From Conceptual Change Model

    OpenAIRE

    Redhana, I. W; Sudria, I. B. N; Hidayat, I; Merta, L. M

    2017-01-01

    This study aimed at describing and explaining chemistry learning problems viewed from conceptual change model and misconceptions of students. The study was qualitative research of case study type conducted in one class of SMAN 1 Singaraja. Subjects of the study were a chemistry teacher and students. Data were obtained through classroom observation, interviews, and conception tests. The chemistry learning problems were grouped based on aspects of necessity, intelligibility, plausibility, and f...

  10. UZ Flow Models and Submodels

    Energy Technology Data Exchange (ETDEWEB)

    Y. Wu

    2004-11-01

    The purpose of this report is to document the unsaturated zone (UZ) flow models and submodels, as well as the flow fields that have been generated using the UZ flow model(s) of Yucca Mountain, Nevada. In this report, the term ''UZ model'' refers to the UZ flow model and the several submodels, which include tracer transport, temperature or ambient geothermal, pneumatic or gas flow, and geochemistry (chloride, calcite, and strontium) submodels. The term UZ flow model refers to the three-dimensional models used for calibration and simulation of UZ flow fields. This work was planned in the ''Technical Work Plan (TWP) for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.7). The table of included Features, Events, and Processes (FEPs), Table 6.2-11, is different from the list of included FEPs assigned to this report in the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Table 2.1.5-1), as discussed in Section 6.2.6. The UZ model has revised, updated, and enhanced the previous UZ model (BSC 2001 [DIRS 158726]) by incorporating the repository design with new grids, recalibration of property sets, and more comprehensive validation effort. The flow fields describe fracture-fracture, matrix-matrix, and fracture-matrix liquid flow rates, and their spatial distributions as well as moisture conditions in the UZ system. These three-dimensional UZ flow fields are used directly by Total System Performance Assessment (TSPA). The model and submodels evaluate important hydrogeologic processes in the UZ as well as geochemistry and geothermal conditions. These provide the necessary framework to test hypotheses of flow and transport at different scales, and predict flow and transport behavior under a variety of climatic conditions. In addition, the limitations of the UZ model are discussed in Section 8.11.

  11. Using Annotated Conceptual Models to Derive Information System Implementations

    Directory of Open Access Journals (Sweden)

    Anthony Berglas

    1994-05-01

    Full Text Available Producing production quality information systems from conceptual descriptions is a time consuming process that employs many of the world's programmers. Although most of this programming is fairly routine, the process has not been amenable to simple automation because conceptual models do not provide sufficient parameters to make all the implementation decisions that are required, and numerous special cases arise in practice. Most commercial CASE tools address these problems by essentially implementing a waterfall model in which the development proceeds from analysis through design, layout and coding phases in a partially automated manner, but the analyst/programmer must heavily edit each intermediate stage. This paper demonstrates that by recognising the nature of information systems, it is possible to specify applications completely using a conceptual model that has een annotated with additional parameters that guide automated implementation. More importantly, it will be argued that a manageable number of annotations are sufficient to implement realistic applications, and techniques will be described that enabled the author's commercial CASE tool, the Intelligent Develope to automated implementation without requiring complex theorem proving technology.

  12. Conceptual Model of Climate Change Impacts at LANL

    Energy Technology Data Exchange (ETDEWEB)

    Dewart, Jean Marie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-17

    Goal 9 of the LANL FY15 Site Sustainability Plan (LANL 2014a) addresses Climate Change Adaptation. As part of Goal 9, the plan reviews many of the individual programs the Laboratory has initiated over the past 20 years to address climate change impacts to LANL (e.g. Wildland Fire Management Plan, Forest Management Plan, etc.). However, at that time, LANL did not yet have a comprehensive approach to climate change adaptation. To fill this gap, the FY15 Work Plan for the LANL Long Term Strategy for Environmental Stewardship and Sustainability (LANL 2015) included a goal of (1) establishing a comprehensive conceptual model of climate change impacts at LANL and (2) establishing specific climate change indices to measure climate change and impacts at Los Alamos. Establishing a conceptual model of climate change impacts will demonstrate that the Laboratory is addressing climate change impacts in a comprehensive manner. This paper fulfills the requirement of goal 1. The establishment of specific indices of climate change at Los Alamos (goal 2), will improve our ability to determine climate change vulnerabilities and assess risk. Future work will include prioritizing risks, evaluating options/technologies/costs, and where appropriate, taking actions. To develop a comprehensive conceptual model of climate change impacts, we selected the framework provided in the National Oceanic and Atmospheric Administration (NOAA) Climate Resilience Toolkit (http://toolkit.climate.gov/).

  13. Conceptual Model of IT Infrastructure Capability and Its Empirical Justification

    Institute of Scientific and Technical Information of China (English)

    QI Xianfeng; LAN Boxiong; GUO Zhenwei

    2008-01-01

    Increasing importance has been attached to the value of information technology (IT) infrastructure in today's organizations. The development of efficacious IT infrastructure capability enhances business performance and brings sustainable competitive advantage. This study analyzed the IT infrastructure capability in a holistic way and then presented a concept model of IT capability. IT infrastructure capability was categorized into sharing capability, service capability, and flexibility. This study then empirically tested the model using a set of survey data collected from 145 firms. Three factors emerge from the factor analysis as IT flexibility, IT service capability, and IT sharing capability, which agree with those in the conceptual model built in this study.

  14. The treatment of conceptual model uncertainty for Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Boak, J.M.; Flint, A.; Dockery, H.A.

    1995-01-01

    A reasonable risk assessment of radioactive waste disposals faces three main problems : 1) the ability of the conceptual model to account for the effective repository process ; 2) the boundary conditions ; 3) the parameters values that model the particular site. Yucca mountain Site Characterization Project deals with these problems through two major approaches that are described here : 1) the evolution of models for the recurrence rate of volcanism ; 2) the nominal hydrologic performance for the site. These two approaches are expected to lead to a reasonable demonstration of the suitability of the site. (D.L.). 13 refs., 2 figs

  15. Conceptual Model of Quantities, Units, Dimensions, and Values

    Science.gov (United States)

    Rouquette, Nicolas F.; DeKoenig, Hans-Peter; Burkhart, Roger; Espinoza, Huascar

    2011-01-01

    JPL collaborated with experts from industry and other organizations to develop a conceptual model of quantities, units, dimensions, and values based on the current work of the ISO 80000 committee revising the International System of Units & Quantities based on the International Vocabulary of Metrology (VIM). By providing support for ISO 80000 in SysML via the International Vocabulary of Metrology (VIM), this conceptual model provides, for the first time, a standard-based approach for addressing issues of unit coherence and dimensional analysis into the practice of systems engineering with SysML-based tools. This conceptual model provides support for two kinds of analyses specified in the International Vocabulary of Metrology (VIM): coherence of units as well as of systems of units, and dimension analysis of systems of quantities. To provide a solid and stable foundation, the model for defining quantities, units, dimensions, and values in SysML is explicitly based on the concepts defined in VIM. At the same time, the model library is designed in such a way that extensions to the ISQ (International System of Quantities) and SI Units (Systeme International d Unites) can be represented, as well as any alternative systems of quantities and units. The model library can be used to support SysML user models in various ways. A simple approach is to define and document libraries of reusable systems of units and quantities for reuse across multiple projects, and to link units and quantity kinds from these libraries to Unit and QuantityKind stereotypes defined in SysML user models.

  16. Conceptual design and quantification of phosphorus flows and balances at the country scale: The case of France

    Science.gov (United States)

    Senthilkumar, Kalimuthu; Nesme, Thomas; Mollier, Alain; Pellerin, Sylvain

    2012-06-01

    Global biogeochemical cycles have been deeply modified by human activities in recent decades. But detailed studies analyzing the influence of current economic and social organizations on global biogeochemical cycles within a system perspective are still required. Country level offers a relevant scale for assessing nutrient management and identifying key driving forces and possible leaks in the nutrient cycle. Conceptual modeling helps to quantify nutrient flows within the country and we developed such an approach for France. France is a typical Western European country with intensive agriculture, trade and an affluent diet, all of which may increase internal and external P flows. Phosphorus (P) was taken as a case study because phosphate rock is a non-renewable resource which future availability is becoming increasingly bleak. A conceptual model of major P flows at the country scale was designed. France was divided into agriculture, industry, domestic, import and export sectors, and each of these sectors was further divided into compartments. A total of 25 internal and eight external P flows were identified and quantified on a yearly basis for a period of 16 years (from 1990 to 2006) in order to understand long-term P flows. All the P flows were quantified using the substance flow analysis principle. The results showed that the industrial sector remained the largest contributor to P flows in France, followed by the agriculture and domestic sectors. Soil P balance was positive. However, a positive P balance of 18 kg P ha-1 in 1990 was reduced to 4 kg P ha-1 in 2006, mainly due to the reduced application of inorganic P fertilizer. The overall country scale P balance was positive, whereas half of this additional P was lost to the environment mainly through the landfilling of municipal and industrial waste, disposal of treated wastewater from which P was partially removed, and P losses from agricultural soils though erosion and leaching. Consequences for global P

  17. Conceptual Models in Health Informatics Research: A Literature Review and Suggestions for Development.

    Science.gov (United States)

    Gray, Kathleen; Sockolow, Paulina

    2016-02-24

    Contributing to health informatics research means using conceptual models that are integrative and explain the research in terms of the two broad domains of health science and information science. However, it can be hard for novice health informatics researchers to find exemplars and guidelines in working with integrative conceptual models. The aim of this paper is to support the use of integrative conceptual models in research on information and communication technologies in the health sector, and to encourage discussion of these conceptual models in scholarly forums. A two-part method was used to summarize and structure ideas about how to work effectively with conceptual models in health informatics research that included (1) a selective review and summary of the literature of conceptual models; and (2) the construction of a step-by-step approach to developing a conceptual model. The seven-step methodology for developing conceptual models in health informatics research explained in this paper involves (1) acknowledging the limitations of health science and information science conceptual models; (2) giving a rationale for one's choice of integrative conceptual model; (3) explicating a conceptual model verbally and graphically; (4) seeking feedback about the conceptual model from stakeholders in both the health science and information science domains; (5) aligning a conceptual model with an appropriate research plan; (6) adapting a conceptual model in response to new knowledge over time; and (7) disseminating conceptual models in scholarly and scientific forums. Making explicit the conceptual model that underpins a health informatics research project can contribute to increasing the number of well-formed and strongly grounded health informatics research projects. This explication has distinct benefits for researchers in training, research teams, and researchers and practitioners in information, health, and other disciplines.

  18. Centrifuge modelling of granular flows

    Science.gov (United States)

    Cabrera, Miguel Angel; Wu, Wei

    2015-04-01

    A common characteristic of mass flows like debris flows, rock avalanches and mudflows is that gravity is their main driving force. Gravity defines the intensity and duration of the main interactions between particles and their surrounding media (particle-particle, particle-fluid, fluid-fluid). At the same time, gravity delimits the occurrence of phase separation, inverse segregation, and mass consolidation, among other phenomena. Therefore, in the understanding of the flow physics it is important to account for the scaling of gravity in scaled models. In this research, a centrifuge model is developed to model free surface granular flows down an incline at controlled gravity conditions. Gravity is controlled by the action of an induced inertial acceleration field resulting from the rotation of the model in a geotechnical centrifuge. The characteristics of the induced inertial acceleration field during flow are discussed and validated via experimental data. Flow heights, velocity fields, basal pressure and impact forces are measured for a range of channel inclinations and gravity conditions. Preliminary results enlighten the flow characteristics at variable gravity conditions and open a discussion on the simulation of large scale processes at a laboratory scale. Further analysis on the flow physics brings valuable information for the validation of granular flows rheology.

  19. A conceptual and disease model framework for osteoporotic kyphosis.

    Science.gov (United States)

    Bayliss, M; Miltenburger, C; White, M; Alvares, L

    2013-09-01

    This paper presents a multi-method research project to develop a conceptual framework for measuring outcomes in studies of osteoporotic kyphosis. The research involved literature research and qualitative interviews among clinicians who treat patients with kyphosis and among patients with the condition. Kyphosis due to at least one vertebral compression fracture is prevalent among osteoporotic patients, resulting in well-documented symptoms and impact on functioning and well-being. A three-part study led to development of a conceptual measurement framework for comprehensive assessment of symptoms, impact, and treatment benefit for kyphosis. A literature-based disease model (DM) was developed and tested with physicians (n = 10) and patients (n = 10), and FDA guidelines were used to develop a final disease model and a conceptual framework. The DM included signs, symptoms, causes/triggers, exacerbations, and functional status associated with kyphosis. The DM was largely confirmed, but physicians and patients added several concepts related to impact on functioning, and some concepts were not confirmed and removed from the DM. This study confirms the need for more comprehensive assessment of health outcomes in kyphosis, as most current studies omit key concepts.

  20. Conceptual Modeling in the Time of the Revolution: Part II

    Science.gov (United States)

    Mylopoulos, John

    Conceptual Modeling was a marginal research topic at the very fringes of Computer Science in the 60s and 70s, when the discipline was dominated by topics focusing on programs, systems and hardware architectures. Over the years, however, the field has moved to centre stage and has come to claim a central role both in Computer Science research and practice in diverse areas, such as Software Engineering, Databases, Information Systems, the Semantic Web, Business Process Management, Service-Oriented Computing, Multi-Agent Systems, Knowledge Management, and more. The transformation was greatly aided by the adoption of standards in modeling languages (e.g., UML), and model-based methodologies (e.g., Model-Driven Architectures) by the Object Management Group (OMG) and other standards organizations. We briefly review the history of the field over the past 40 years, focusing on the evolution of key ideas. We then note some open challenges and report on-going research, covering topics such as the representation of variability in conceptual models, capturing model intentions, and models of laws.

  1. Operations and support cost modeling of conceptual space vehicles

    Science.gov (United States)

    Ebeling, Charles

    1994-01-01

    The University of Dayton is pleased to submit this annual report to the National Aeronautics and Space Administration (NASA) Langley Research Center which documents the development of an operations and support (O&S) cost model as part of a larger life cycle cost (LCC) structure. It is intended for use during the conceptual design of new launch vehicles and spacecraft. This research is being conducted under NASA Research Grant NAG-1-1327. This research effort changes the focus from that of the first two years in which a reliability and maintainability model was developed to the initial development of an operations and support life cycle cost model. Cost categories were initially patterned after NASA's three axis work breakdown structure consisting of a configuration axis (vehicle), a function axis, and a cost axis. A revised cost element structure (CES), which is currently under study by NASA, was used to established the basic cost elements used in the model. While the focus of the effort was on operations and maintenance costs and other recurring costs, the computerized model allowed for other cost categories such as RDT&E and production costs to be addressed. Secondary tasks performed concurrent with the development of the costing model included support and upgrades to the reliability and maintainability (R&M) model. The primary result of the current research has been a methodology and a computer implementation of the methodology to provide for timely operations and support cost analysis during the conceptual design activities.

  2. 300 kWt core conceptual model thermal/hydraulic characteristics

    International Nuclear Information System (INIS)

    Moody, E.

    1971-01-01

    The 300 kW(t), 199 element NASA-Lewis/AEC core conceptual model, has been analyzed to determine it's thermal-hydraulic characteristics using the GEOM-3 code. Stack-ups of tolerances and fuel rod asymmetry patterns were used to ascertain cross element Δ T's. Both zoned and uniform spacing were analyzed with a somewhat lower fuel temperature and cross element ΔT found for zoned spacing. With the models considered, the core design appears adequate to limit thermal gradients to approximately 32 0 F. Bypass flow should be controlled to prevent excessive edge element ΔT's. 11 references. (U.S.)

  3. A Conceptual Model of the Pasadena Housing System

    Science.gov (United States)

    Hirshberg, Alan S.; Barber, Thomas A.

    1971-01-01

    During the last 5 years, there have been several attempts at applying systems analysis to complex urban problems. This paper describes one such attempt by a multidisciplinary team of students, engineers, professors, and community representatives. The Project organization is discussed and the interaction of the different disciplines (the process) described. The two fundamental analysis questions posed by the Project were: "Why do houses deteriorate?" and "Why do people move?" The analysis of these questions led to the development of a conceptual system model of housing in Pasadena. The major elements of this model are described, and several conclusions drawn from it are presented.

  4. A Conceptual Model of eLearning Adoption

    Directory of Open Access Journals (Sweden)

    Muneer Abbad

    2011-05-01

    Full Text Available Internet-based learning systems are being used in many universities and firms but their adoption requires a solid understanding of the user acceptance processes. The technology acceptance model (TAM has been used to test the acceptance of various technologies and software within an e-learning context. This research aims to discuss the main factors of a successful e-learning adoption by students. A conceptual research framework of e-learning adoption is proposed based on the TAM model.

  5. A Conceptual Model for Multidimensional Analysis of Documents

    Science.gov (United States)

    Ravat, Franck; Teste, Olivier; Tournier, Ronan; Zurlfluh, Gilles

    Data warehousing and OLAP are mainly used for the analysis of transactional data. Nowadays, with the evolution of Internet, and the development of semi-structured data exchange format (such as XML), it is possible to consider entire fragments of data such as documents as analysis sources. As a consequence, an adapted multidimensional analysis framework needs to be provided. In this paper, we introduce an OLAP multidimensional conceptual model without facts. This model is based on the unique concept of dimensions and is adapted for multidimensional document analysis. We also provide a set of manipulation operations.

  6. Robust Bayesian Experimental Design for Conceptual Model Discrimination

    Science.gov (United States)

    Pham, H. V.; Tsai, F. T. C.

    2015-12-01

    A robust Bayesian optimal experimental design under uncertainty is presented to provide firm information for model discrimination, given the least number of pumping wells and observation wells. Firm information is the maximum information of a system can be guaranteed from an experimental design. The design is based on the Box-Hill expected entropy decrease (EED) before and after the experiment design and the Bayesian model averaging (BMA) framework. A max-min programming is introduced to choose the robust design that maximizes the minimal Box-Hill EED subject to that the highest expected posterior model probability satisfies a desired probability threshold. The EED is calculated by the Gauss-Hermite quadrature. The BMA method is used to predict future observations and to quantify future observation uncertainty arising from conceptual and parametric uncertainties in calculating EED. Monte Carlo approach is adopted to quantify the uncertainty in the posterior model probabilities. The optimal experimental design is tested by a synthetic 5-layer anisotropic confined aquifer. Nine conceptual groundwater models are constructed due to uncertain geological architecture and boundary condition. High-performance computing is used to enumerate all possible design solutions in order to identify the most plausible groundwater model. Results highlight the impacts of scedasticity in future observation data as well as uncertainty sources on potential pumping and observation locations.

  7. A Conceptual Culture Model for Design Science Research

    Directory of Open Access Journals (Sweden)

    Thomas Richter

    2016-03-01

    Full Text Available The aim of design science research (DSR in information systems is the user-centred creation of IT-artifacts with regard to specific social environments. For culture research in the field, which is necessary for a proper localization of IT-artifacts, models and research approaches from social sciences usually are adopted. Descriptive dimension-based culture models most commonly are applied for this purpose, which assume culture being a national phenomenon and tend to reduce it to basic values. Such models are useful for investigations in behavioural culture research because it aims to isolate, describe and explain culture-specific attitudes and characteristics within a selected society. In contrast, with the necessity to deduce concrete decisions for artifact-design, research results from DSR need to go beyond this aim. As hypothesis, this contribution generally questions the applicability of such generic culture dimensions’ models for DSR and focuses on their theoretical foundation, which goes back to Hofstede’s conceptual Onion Model of Culture. The herein applied literature-based analysis confirms the hypothesis. Consequently, an alternative conceptual culture model is being introduced and discussed as theoretical foundation for culture research in DSR.

  8. A simple conceptual model of abrupt glacial climate events

    Directory of Open Access Journals (Sweden)

    H. Braun

    2007-11-01

    Full Text Available Here we use a very simple conceptual model in an attempt to reduce essential parts of the complex nonlinearity of abrupt glacial climate changes (the so-called Dansgaard-Oeschger events to a few simple principles, namely (i the existence of two different climate states, (ii a threshold process and (iii an overshooting in the stability of the system at the start and the end of the events, which is followed by a millennial-scale relaxation. By comparison with a so-called Earth system model of intermediate complexity (CLIMBER-2, in which the events represent oscillations between two climate states corresponding to two fundamentally different modes of deep-water formation in the North Atlantic, we demonstrate that the conceptual model captures fundamental aspects of the nonlinearity of the events in that model. We use the conceptual model in order to reproduce and reanalyse nonlinear resonance mechanisms that were already suggested in order to explain the characteristic time scale of Dansgaard-Oeschger events. In doing so we identify a new form of stochastic resonance (i.e. an overshooting stochastic resonance and provide the first explicitly reported manifestation of ghost resonance in a geosystem, i.e. of a mechanism which could be relevant for other systems with thresholds and with multiple states of operation. Our work enables us to explicitly simulate realistic probability measures of Dansgaard-Oeschger events (e.g. waiting time distributions, which are a prerequisite for statistical analyses on the regularity of the events by means of Monte-Carlo simulations. We thus think that our study is an important advance in order to develop more adequate methods to test the statistical significance and the origin of the proposed glacial 1470-year climate cycle.

  9. Conceptual-level workflow modeling of scientific experiments using NMR as a case study

    Directory of Open Access Journals (Sweden)

    Gryk Michael R

    2007-01-01

    Full Text Available Abstract Background Scientific workflows improve the process of scientific experiments by making computations explicit, underscoring data flow, and emphasizing the participation of humans in the process when intuition and human reasoning are required. Workflows for experiments also highlight transitions among experimental phases, allowing intermediate results to be verified and supporting the proper handling of semantic mismatches and different file formats among the various tools used in the scientific process. Thus, scientific workflows are important for the modeling and subsequent capture of bioinformatics-related data. While much research has been conducted on the implementation of scientific workflows, the initial process of actually designing and generating the workflow at the conceptual level has received little consideration. Results We propose a structured process to capture scientific workflows at the conceptual level that allows workflows to be documented efficiently, results in concise models of the workflow and more-correct workflow implementations, and provides insight into the scientific process itself. The approach uses three modeling techniques to model the structural, data flow, and control flow aspects of the workflow. The domain of biomolecular structure determination using Nuclear Magnetic Resonance spectroscopy is used to demonstrate the process. Specifically, we show the application of the approach to capture the workflow for the process of conducting biomolecular analysis using Nuclear Magnetic Resonance (NMR spectroscopy. Conclusion Using the approach, we were able to accurately document, in a short amount of time, numerous steps in the process of conducting an experiment using NMR spectroscopy. The resulting models are correct and precise, as outside validation of the models identified only minor omissions in the models. In addition, the models provide an accurate visual description of the control flow for conducting

  10. Towards Smart and Resilient City: A Conceptual Model

    Science.gov (United States)

    Arafah, Y.; Winarso, H.; Suroso, D. S. A.

    2018-05-01

    This paper aims to compare five smart city models selected based on a number of specific criteria. Following the comparison and assessment performed, we draw conclusions and further linkages identifying the components and characters found in resilient cities. The purpose of this analysis is to produce a new approach and concept: the “smart and resilient city.” Through in-depth literature study, this paper analyzes five conceptual smart city models deemed to have a background, point of view, and benchmark towards software group, as they focus on welfare, inclusion, social equality, and competitiveness. Analyzing the strategies, methods, and techniques of five smart city models, this paper concludes that there has been no inclusion of resilience concepts in the assessment, especially in the context of natural disasters. Basically, the models are also interrelated and there are some things that overlap. As a recommendation, there is a model that tries to combine the components and character of smart city and resilient city into one entity that is embedded as a whole in a conceptual picture towards the new concept, the “smart and resilient city”. The concept of smart city and resilient city go hand in hand with each other and thus are interrelated. Therefore, it is imperative to study that concept deeper, in this case primarily in the context of disaster.

  11. Our evolving conceptual model of the coastal eutrophication problem

    Science.gov (United States)

    Cloern, James E.

    2001-01-01

    A primary focus of coastal science during the past 3 decades has been the question: How does anthropogenic nutrient enrichment cause change in the structure or function of nearshore coastal ecosystems? This theme of environmental science is recent, so our conceptual model of the coastal eutrophication problem continues to change rapidly. In this review, I suggest that the early (Phase I) conceptual model was strongly influenced by limnologists, who began intense study of lake eutrophication by the 1960s. The Phase I model emphasized changing nutrient input as a signal, and responses to that signal as increased phytoplankton biomass and primary production, decomposition of phytoplankton-derived organic matter, and enhanced depletion of oxygen from bottom waters. Coastal research in recent decades has identified key differences in the responses of lakes and coastal-estuarine ecosystems to nutrient enrichment. The contemporary (Phase II) conceptual model reflects those differences and includes explicit recognition of (1) system-specific attributes that act as a filter to modulate the responses to enrichment (leading to large differences among estuarine-coastal systems in their sensitivity to nutrient enrichment); and (2) a complex suite of direct and indirect responses including linked changes in: water transparency, distribution of vascular plants and biomass of macroalgae, sediment biogeochemistry and nutrient cycling, nutrient ratios and their regulation of phytoplankton community composition, frequency of toxic/harmful algal blooms, habitat quality for metazoans, reproduction/growth/survival of pelagic and benthic invertebrates, and subtle changes such as shifts in the seasonality of ecosystem functions. Each aspect of the Phase II model is illustrated here with examples from coastal ecosystems around the world. In the last section of this review I present one vision of the next (Phase III) stage in the evolution of our conceptual model, organized around 5

  12. Dense granular Flows: a conceptual design of high-power neutron source

    Directory of Open Access Journals (Sweden)

    Yang Lei

    2017-01-01

    Full Text Available A high-power neutron source system is very useful for multifunctional applications, such as material facilities for advanced nuclear power, space radiation studies, radiography and tomography. Here the idea of inclined dense granular flow is utilized and developed in a new conceptual design of a compact high-power target to produce a high-energy and high-flux neutron irradiation (the flux is up to 1015 n/cm2/s or even 1016. Comparing to the traditional solid and liquid heavy metal targets, this design has advantages in material choice, fluid stability, heat removal, etc. In this paper the natures of the granular flows in an inclined chute are investigated and preliminary experimental and numerical results are reported. Then the feasibility of this design is discussed.

  13. Models for tracer flow

    International Nuclear Information System (INIS)

    Zuber, A.

    1983-01-01

    A review and discussion is given of mathematical models used for interpretation of tracer experiments in hydrology. For dispersion model, different initial and boundary conditions are related to different injection and detection modes. Examples of applications of various models are described and commented. (author)

  14. A CONCEPTUAL MODEL FOR EFFECTIVE DISTANCE LEARNING IN HIGHER A CONCEPTUAL MODEL FOR EFFECTIVE DISTANCE LEARNING IN HIGHER A CONCEPTUAL MODEL FOR EFFECTIVE DISTANCE LEARNING IN HIGHER EDUCATION

    Directory of Open Access Journals (Sweden)

    Mehran FARAJOLLAHI

    2010-07-01

    Full Text Available The present research aims at presenting a conceptual model for effective distance learning in higher education. Findings of this research shows that an understanding of the technological capabilities and learning theories especially constructive theory and independent learning theory and communicative and interaction theory in Distance learning is an efficient factor in the planning of effective Distance learning in higher education. Considering the theoretical foundations of the present research, in the effective distance learning model, the learner is situated at the center of learning environment. For this purpose, the learner needs to be ready for successful learning and the teacher has to be ready to design the teaching- learning activities when they initially enter the environment. In the present model, group and individual active teaching-learning approach, timely feedback, using IT and eight types of interactions have been designed with respect to theoretical foundations and current university missions. From among the issues emphasized in this model, one can refer to the Initial, Formative and Summative evaluations. In an effective distance learning environment, evaluation should be part of the learning process and the feedback resulting from it should be used to improve learning. For validating the specified features, the opinions of Distance learning experts in Payame Noor, Shiraz, Science and Technology and Amirkabir Universities have been used which verified a high percentage of the statistical sample of the above mentioned features.

  15. Development and validation of a mass casualty conceptual model.

    Science.gov (United States)

    Culley, Joan M; Effken, Judith A

    2010-03-01

    To develop and validate a conceptual model that provides a framework for the development and evaluation of information systems for mass casualty events. The model was designed based on extant literature and existing theoretical models. A purposeful sample of 18 experts validated the model. Open-ended questions, as well as a 7-point Likert scale, were used to measure expert consensus on the importance of each construct and its relationship in the model and the usefulness of the model to future research. Computer-mediated applications were used to facilitate a modified Delphi technique through which a panel of experts provided validation for the conceptual model. Rounds of questions continued until consensus was reached, as measured by an interquartile range (no more than 1 scale point for each item); stability (change in the distribution of responses less than 15% between rounds); and percent agreement (70% or greater) for indicator questions. Two rounds of the Delphi process were needed to satisfy the criteria for consensus or stability related to the constructs, relationships, and indicators in the model. The panel reached consensus or sufficient stability to retain all 10 constructs, 9 relationships, and 39 of 44 indicators. Experts viewed the model as useful (mean of 5.3 on a 7-point scale). Validation of the model provides the first step in understanding the context in which mass casualty events take place and identifying variables that impact outcomes of care. This study provides a foundation for understanding the complexity of mass casualty care, the roles that nurses play in mass casualty events, and factors that must be considered in designing and evaluating information-communication systems to support effective triage under these conditions.

  16. Can Bayesian Belief Networks help tackling conceptual model uncertainties in contaminated site risk assessment?

    DEFF Research Database (Denmark)

    Troldborg, Mads; Thomsen, Nanna Isbak; McKnight, Ursula S.

    different conceptual models may describe the same contaminated site equally well. In many cases, conceptual model uncertainty has been shown to be one of the dominant sources for uncertainty and is therefore essential to account for when quantifying uncertainties in risk assessments. We present here......A key component in risk assessment of contaminated sites is the formulation of a conceptual site model. The conceptual model is a simplified representation of reality and forms the basis for the mathematical modelling of contaminant fate and transport at the site. A conceptual model should...... a Bayesian Belief Network (BBN) approach for evaluating the uncertainty in risk assessment of groundwater contamination from contaminated sites. The approach accounts for conceptual model uncertainty by considering multiple conceptual models, each of which represents an alternative interpretation of the site...

  17. A conceptual model of psychological contracts in construction projects

    Directory of Open Access Journals (Sweden)

    Yongjian Ke

    2016-09-01

    Full Text Available The strategic importance of relationship style contracting is recognised in the construction industry. Both public and private sector clients are stipulating more integrated and collaborative forms of procurement. Despite relationship and integrated contractual arrangement being available for some time, it is clear that construction firms have been slow to adopt them. Hence it is timely to examine how social exchanges, via unwritten agreement and behaviours, are being nurtured in construction projects. This paper adopted the concept of Psychological Contracts (PC to describe unwritten agreement and behaviours. A conceptual model of the PC is developed and validated using the results from a questionnaire survey administered to construction professionals in Australia. The results uncovered the relationships that existed amongst relational conditions and relational benefits, the PC and the partners’ satisfaction. The results show that all the hypotheses in the conceptual model of the PC are supported, suggesting the PC model is important and may have an effect on project performance and relationship quality among contracting parties. A validated model of the PC in construction was then developed based on the correlations among each component. The managerial implications are that past relationships and relationship characteristics should be taken into account in the selection of procurement partners and the promise of future resources, support and tangible relational outcomes are also vital. It is important for contracting parties to pay attention to unwritten agreements (the PC and behaviours when managing construction projects.

  18. Strategies to Move From Conceptual Models to Quantifying Resilience in FEW Systems

    Science.gov (United States)

    Padowski, J.; Adam, J. C.; Boll, J.; Barber, M. E.; Cosens, B.; Goldsby, M.; Fortenbery, R.; Fowler, A.; Givens, J.; Guzman, C. D.; Hampton, S. E.; Harrison, J.; Huang, M.; Katz, S. L.; Kraucunas, I.; Kruger, C. E.; Liu, M.; Luri, M.; Malek, K.; Mills, A.; McLarty, D.; Pickering, N. B.; Rajagopalan, K.; Stockle, C.; Richey, A.; Voisin, N.; Witinok-Huber, B.; Yoder, J.; Yorgey, G.; Zhao, M.

    2017-12-01

    Understanding interdependencies within Food-Energy-Water (FEW) systems is critical to maintain FEW security. This project examines how coordinated management of physical (e.g., reservoirs, aquifers, and batteries) and non-physical (e.g., water markets, social capital, and insurance markets) storage systems across the three sectors promotes resilience. Coordination increases effective storage within the overall system and enhances buffering against shocks at multiple scales. System-wide resilience can be increased with innovations in technology (e.g., smart systems and energy storage) and institutions (e.g., economic systems and water law). Using the Columbia River Basin as our geographical study region, we use an integrated approach that includes a continuum of science disciplines, moving from theory to practice. In order to understand FEW linkages, we started with detailed, connected conceptual models of the food, energy, water, and social systems to identify where key interdependencies (i.e., overlaps, stocks, and flows) exist within and between systems. These are used to identify stress and opportunity points, develop innovation solutions across FEW sectors, remove barriers to the adoption of solutions, and quantify increases in system-wide resilience to regional and global change. The conceptual models act as a foundation from which we can identify key drivers, parameters, time steps, and variables of importance to build and improve existing systems dynamic and biophysical models. Our process of developing conceptual models and moving to integrated modeling is critical and serves as a foundation for coupling quantitative components with economic and social domain components and analyses of how these interact through time and space. This poster provides a description of this process that pulls together conceptual maps and integrated modeling output to quantify resilience across all three of the FEW sectors (a.k.a. "The Resilience Calculator"). Companion posters

  19. Statistical and Conceptual Model Testing Geomorphic Principles through Quantification in the Middle Rio Grande River, NM.

    Science.gov (United States)

    Posner, A. J.

    2017-12-01

    The Middle Rio Grande River (MRG) traverses New Mexico from Cochiti to Elephant Butte reservoirs. Since the 1100s, cultivating and inhabiting the valley of this alluvial river has required various river training works. The mid-20th century saw a concerted effort to tame the river through channelization, Jetty Jacks, and dam construction. A challenge for river managers is to better understand the interactions between a river training works, dam construction, and the geomorphic adjustments of a desert river driven by spring snowmelt and summer thunderstorms carrying water and large sediment inputs from upstream and ephemeral tributaries. Due to its importance to the region, a vast wealth of data exists for conditions along the MRG. The investigation presented herein builds upon previous efforts by combining hydraulic model results, digitized planforms, and stream gage records in various statistical and conceptual models in order to test our understanding of this complex system. Spatially continuous variables were clipped by a set of river cross section data that is collected at decadal intervals since the early 1960s, creating a spatially homogenous database upon which various statistical testing was implemented. Conceptual models relate forcing variables and response variables to estimate river planform changes. The developed database, represents a unique opportunity to quantify and test geomorphic conceptual models in the unique characteristics of the MRG. The results of this investigation provides a spatially distributed characterization of planform variable changes, permitting managers to predict planform at a much higher resolution than previously available, and a better understanding of the relationship between flow regime and planform changes such as changes to longitudinal slope, sinuosity, and width. Lastly, data analysis and model interpretation led to the development of a new conceptual model for the impact of ephemeral tributaries in alluvial rivers.

  20. Turbulence models in supersonic flows

    International Nuclear Information System (INIS)

    Shirani, E.; Ahmadikia, H.; Talebi, S.

    2001-05-01

    The aim of this paper is to evaluate five different turbulence models when used in rather complicated two-dimensional and axisymmetric supersonic flows. They are Baldwin-Lomax, k-l, k-ε, k-ω and k-ζ turbulence models. The compressibility effects, axisymmetric correction terms and some modifications for transition region are used and tested in the models. Two computer codes based on the control volume approach and two flux-splitting methods. Roe and Van Leer, are developed. The codes are used to simulate supersonic mixing layers, flow behind axisymmetric body, under expanded jet, and flow over hollow cylinder flare. The results are compared with experimental data and behavior of the turbulence models is examined. It is shown that both k-l and k-ζ models produce very good results. It is also shown that the compressibility correction in the model is required to obtain more accurate results. (author)

  1. Homeland Security and Information Control: A Model of Asymmetric Information Flows.

    Science.gov (United States)

    Maxwell, Terrence A.

    2003-01-01

    Summarizes some of the activities the United States government has undertaken to control the dissemination of information since 2001. It also explores, through a conceptual model of information flows, potential impacts and discontinuities between policy purposes and outcomes. (AEF)

  2. MISCO: A Conceptual Model for MIS Implementation in SMEs

    Directory of Open Access Journals (Sweden)

    R.Bali

    1999-01-01

    Full Text Available Information Technology ('IT' has made a prolific impact, both in sociological and commercial terms. In the business world, the pursuit of new technology and working practices has often been at the expense of equal regard for the correct methods to manage the new technology. Contemporary IT techniques and methods include Management Information Systems ('MIS' which are normally implemented on a company-wide basis. However, MIS implementation has major cultural and organisational implications which will form the main focus of this paper. A conceptual model is proposed for successful MIS implementation which combines established research findings with ethnographically-informed data from a small, UK-based, business.

  3. Penetration Testing Professional Ethics: a conceptual model and taxonomy

    Directory of Open Access Journals (Sweden)

    Justin Pierce

    2006-05-01

    Full Text Available In an environment where commercial software is continually patched to correct security flaws, penetration testing can provide organisations with a realistic assessment of their security posture. Penetration testing uses the same principles as criminal hackers to penetrate corporate networks and thereby verify the presence of software vulnerabilities. Network administrators can use the results of a penetration test to correct flaws and improve overall security. The use of hacking techniques, however, raises several ethical questions that centre on the integrity of the tester to maintain professional distance and uphold the profession. This paper discusses the ethics of penetration testing and presents our conceptual model and revised taxonomy.

  4. Conceptual Development af a 3D Product Configuration Model

    DEFF Research Database (Denmark)

    Skauge, Jørn

    2006-01-01

    in the development of IT-systems that support the procedures in companies and in the building industry. In other words, it is a knowledge-based system that helps companies in their daily work. The aim of the project has been to develop and examine conceptual ideas about 3D modelling configurator used in the company......’s production of steel fire sliding doors. The development of the 3D digital model is based on practical rather than theoretical research. The result of the research is a prototype digital 3D model to be presented live.......Paper. This project deals with 3D product configuration of a digital building element which has been developed as a prototype in cooperation between a product manufacturer and a research institution in Denmark. The project falls within the concept of product modelling which is more and more used...

  5. Conceptual model for deriving the repository source term

    International Nuclear Information System (INIS)

    Alexander, D.H.; Apted, M.J.; Liebetrau, A.M.; Van Luik, A.E.; Williford, R.E.; Doctor, P.G.; Pacific Northwest Lab., Richland, WA; Roy F. Weston, Inc./Rogers and Assoc. Engineering Corp., Rockville, MD)

    1984-01-01

    Part of a strategy for evaluating the compliance of geologic repositories with Federal regulations is a modeling approach that would provide realistic release estimates for a particular configuration of the engineered-barrier system. The objective is to avoid worst-case bounding assumptions that are physically impossible or excessively conservative and to obtain probabilitistic estimates of (1) the penetration time for metal barriers and (2) radionuclide-release rates for individually simulated waste packages after penetration has occurred. The conceptual model described in this paper will assume that release rates are explicitly related to such time-dependent processes as mass transfer, dissolution and precipitation, radionuclide decay, and variations in the geochemical environment. The conceptual model will take into account the reduction in the rates of waste-form dissolution and metal corrosion due to a buildup of chemical reaction products. The sorptive properties of the metal-barrier corrosion products in proximity to the waste form surface will also be included. Cumulative released from the engineered-barrier system will be calculated by summing the releases from a probabilistically generated population of individual waste packages. 14 refs., 7 figs

  6. Conceptual model for deriving the repository source term

    International Nuclear Information System (INIS)

    Alexander, D.H.; Apted, M.J.; Liebetrau, A.M.; Doctor, P.G.; Williford, R.E.; Van Luik, A.E.

    1984-11-01

    Part of a strategy for evaluating the compliance of geologic repositories with federal regulations is a modeling approach that would provide realistic release estimates for a particular configuration of the engineered-barrier system. The objective is to avoid worst-case bounding assumptions that are physically impossible or excessively conservative and to obtain probabilistic estimates of (1) the penetration time for metal barriers and (2) radionuclide-release rates for individually simulated waste packages after penetration has occurred. The conceptual model described in this paper will assume that release rates are explicitly related to such time-dependent processes as mass transfer, dissolution and precipitation, radionuclide decay, and variations in the geochemical environment. The conceptual model will take into account the reduction in the rates of waste-form dissolution and metal corrosion due to a buildup of chemical reaction products. The sorptive properties of the metal-barrier corrosion products in proximity to the waste form surface will also be included. Cumulative releases from the engineered-barrier system will be calculated by summing the releases from a probabilistically generated population of individual waste packages. 14 refs., 7 figs

  7. A conceptual gamma shield design using the DRP model computation

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, E E [Reactor Department, Nuclear Research Center, Atomic Energy Authority, Cairo (Egypt); Rahman, F A [National Center of Nuclear Safety and Radiation Control, Atomic Energy Authority, Cairo (Egypt)

    1997-12-31

    The purpose of this investigation is to assess basic areas of concern in the development of reactor shielding conceptual design calculations. A spherical shield model composed of low carbon steel and lead have been constructed to surround a Co-60 gamma point source. two alternative configurations have been considered in the model computation. The numerical calculations have been performed using both the ANISN code and DRP model computation together with the DLC 75-Bugle 80 data library. A resume of results for deep penetration in different shield materials with different packing densities is presented and analysed. The results showed that the gamma fluxes attenuation is increased with increasing distribution the packing density of the shield material which reflects its importance of considering it as a safety parameter in shielding design. 3 figs.

  8. Conceptual models in man-machine design verification

    International Nuclear Information System (INIS)

    Rasmussen, J.

    1985-01-01

    The need for systematic methods for evaluation of design concepts for new man-machine systems has been rapidly increasing in consequence of the introduction of modern information technology. Direct empirical methods are difficult to apply when functions during rare conditions and support of operator decisions during emergencies are to be evaluated. In this paper, the problems of analytical evaluations based on conceptual models of the man-machine interaction are discussed, and the relations to system design and analytical risk assessment are considered. Finally, a conceptual framework for analytical evaluation is proposed, including several domains of description: 1. The problem space, in the form of a means-end hierarchy; 2. The structure of the decision process; 3. The mental strategies and heuristics used by operators; 4. The levels of cognitive control and the mechanisms related to human errors. Finally, the need for models representing operators' subjective criteria for choosing among available mental strategies and for accepting advice from intelligent interfaces is discussed

  9. A conceptual model for translating omic data into clinical action

    Directory of Open Access Journals (Sweden)

    Timothy M Herr

    2015-01-01

    Full Text Available Genomic, proteomic, epigenomic, and other "omic" data have the potential to enable precision medicine, also commonly referred to as personalized medicine. The volume and complexity of omic data are rapidly overwhelming human cognitive capacity, requiring innovative approaches to translate such data into patient care. Here, we outline a conceptual model for the application of omic data in the clinical context, called "the omic funnel." This model parallels the classic "Data, Information, Knowledge, Wisdom pyramid" and adds context for how to move between each successive layer. Its goal is to allow informaticians, researchers, and clinicians to approach the problem of translating omic data from bench to bedside, by using discrete steps with clearly defined needs. Such an approach can facilitate the development of modular and interoperable software that can bring precision medicine into widespread practice.

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

    International Nuclear Information System (INIS)

    Hammond, Glenn E.; Cygan, Randall Timothy

    2007-01-01

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

  11. [Active ageing and success: A brief history of conceptual models].

    Science.gov (United States)

    Petretto, Donatella Rita; Pili, Roberto; Gaviano, Luca; Matos López, Cristina; Zuddas, Carlo

    2016-01-01

    The aim of this paper is to analyse and describe different conceptual models of successful ageing, active and healthy ageing developed in Europe and in America in the 20° century, starting from Rowe and Kahn's original model (1987, 1997). A narrative review was conducted on the literature on successful ageing. Our review included definition of successful ageing from European and American scholars. Models were found that aimed to describe indexes of active and healthy ageing, models devoted to describe processes involved in successful ageing, and additional views that emphasise subjective and objective perception of successful ageing. A description is also given of critiques on previous models and remedies according to Martin et al. (2014) and strategies for successful ageing according to Jeste and Depp (2014). The need is discussed for the enhancement of Rowe and Kahn's model and other models with a more inclusive, universal description of ageing, incorporating scientific evidence regarding active ageing. Copyright © 2015 SEGG. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. Simulation modelling of fynbos ecosystems: Systems analysis and conceptual models

    CSIR Research Space (South Africa)

    Kruger, FJ

    1985-03-01

    Full Text Available -animal interactions. An additional two models, which expand aspects of the FYNBOS model, are described: a model for simulating canopy processes; and a Fire Recovery Simulator. The canopy process model will simulate ecophysiological processes in more detail than FYNBOS...

  13. Modeling of flow through fractured tuff at Fran Ridge

    International Nuclear Information System (INIS)

    Eaton, R.R.; Ho, C.K.; Glass, R.J.; Nicholl, M.J.; Arnold, B.W.

    1996-01-01

    Numerical studies have modeled an infiltration experiment at Fran Ridge, using the TOUGH2 code, to aid in the selection of computational models for waste repository performance assessment. This study investigates the capabilities of TOUGH2 to simulate transient flows through highly fractured tuff, and provides a possible means of calibrating hydrologic parameters such as effective fracture aperture and fracture-matrix connectivity. Two distinctly different conceptual models were used in the TOUGH2 code, the dual permeability model and the equivalent continuum model. The field experiments involved the infiltration of dyed ponded water in highly fractured tuff. The infiltration observed in the experiment was subsequently modeled using Fran Ridge fracture frequencies, obtained during post-experiment site excavation. Comparison of the TOUGH2 results obtained using the two conceptual models gives insight into their relative strengths and weaknesses

  14. Conceptual Models and Theory-Embedded Principles on Effective Schooling.

    Science.gov (United States)

    Scheerens, Jaap

    1997-01-01

    Reviews models and theories on effective schooling. Discusses four rationality-based organization theories and a fifth perspective, chaos theory, as applied to organizational functioning. Discusses theory-embedded principles flowing from these theories: proactive structuring, fit, market mechanisms, cybernetics, and self-organization. The…

  15. A conceptual model to improve performance in virtual teams

    Directory of Open Access Journals (Sweden)

    Shopee Dube

    2016-09-01

    Full Text Available Background: The vast improvement in communication technologies and sophisticated project management tools, methods and techniques has allowed geographically and culturally diverse groups to operate and function in a virtual environment. To succeed in this virtual environment where time and space are becoming increasingly irrelevant, organisations must define new ways of implementing initiatives. This virtual environment phenomenon has brought about the formation of virtual project teams that allow organisations to harness the skills and knowhow of the best resources, irrespective of their location. Objectives: The aim of this article was to investigate performance criteria and develop a conceptual model which can be applied to enhance the success of virtual project teams. There are no clear guidelines of the performance criteria in managing virtual project teams. Method: A qualitative research methodology was used in this article. The purpose of content analysis was to explore the literature to understand the concept of performance in virtual project teams and to summarise the findings of the literature reviewed. Results: The research identified a set of performance criteria for the virtual project teams as follows: leadership, trust, communication, team cooperation, reliability, motivation, comfort and social interaction. These were used to conceptualise the model. Conclusion: The conceptual model can be used in a holistic way to determine the overall performance of the virtual project team, but each factor can be analysed individually to determine the impact on the overall performance. The knowledge of performance criteria for virtual project teams could aid project managers in enhancing the success of these teams and taking a different approach to better manage and coordinate them.

  16. Evaluation of conceptual and numerical models for arsenic mobilization and attenuation during managed aquifer recharge.

    Science.gov (United States)

    Wallis, Ilka; Prommer, Henning; Simmons, Craig T; Post, Vincent; Stuyfzand, Pieter J

    2010-07-01

    Managed Aquifer Recharge (MAR) is promoted as an attractive technique to meet growing water demands. An impediment to MAR applications, where oxygenated water is recharged into anoxic aquifers, is the potential mobilization of trace metals (e.g., arsenic). While conceptual models for arsenic transport under such circumstances exist, they are generally not rigorously evaluated through numerical modeling, especially at field-scale. In this work, geochemical data from an injection experiment in The Netherlands, where the introduction of oxygenated water into an anoxic aquifer mobilized arsenic, was used to develop and evaluate conceptual and numerical models of arsenic release and attenuation under field-scale conditions. Initially, a groundwater flow and nonreactive transport model was developed. Subsequent reactive transport simulations focused on the description of the temporal and spatial evolution of the redox zonation. The calibrated model was then used to study and quantify the transport of arsenic. In the model that best reproduced field observations, the fate of arsenic was simulated by (i) release via codissolution of arsenopyrite, stoichiometrically linked to pyrite oxidation, (ii) kinetically controlled oxidation of dissolved As(III) to As(V), and (iii) As adsorption via surface complexation on neo-precipitated iron oxides.

  17. The structure of conceptual models with application to the Aespoe HRL project

    International Nuclear Information System (INIS)

    Olsson, Olle; Baeckblom, G.; Wikberg, P.; Gustafson, G.; Stanfors, R.

    1994-05-01

    In performance assessment a sequence of models is used to describe the function of the geological barrier. This report proposes a general structure and terminology for description of these models. A model description consists of the following components: A conceptual model which defines the geometric framework in which the problem is solved, the dimensions of the modelled volume, descriptions of the processes included in the model, and the boundary conditions; Data which are introduced into the conceptual model, and a mathematical or numerical tool used to produce output data. Contradictory to common practice in geohydrologic modelling it is proposed that the term conceptual model is restricted to define in what way the model is constructed, and that this is separated from any specific application of the conceptual model. Hence, the conceptual model should not include any specific data. 5 refs, 2 figs, 4 tabs

  18. Climate stability and sensitivity in some simple conceptual models

    Energy Technology Data Exchange (ETDEWEB)

    Bates, J. Ray [University College Dublin, Meteorology and Climate Centre, School of Mathematical Sciences, Dublin (Ireland)

    2012-02-15

    A theoretical investigation of climate stability and sensitivity is carried out using three simple linearized models based on the top-of-the-atmosphere energy budget. The simplest is the zero-dimensional model (ZDM) commonly used as a conceptual basis for climate sensitivity and feedback studies. The others are two-zone models with tropics and extratropics of equal area; in the first of these (Model A), the dynamical heat transport (DHT) between the zones is implicit, in the second (Model B) it is explicitly parameterized. It is found that the stability and sensitivity properties of the ZDM and Model A are very similar, both depending only on the global-mean radiative response coefficient and the global-mean forcing. The corresponding properties of Model B are more complex, depending asymmetrically on the separate tropical and extratropical values of these quantities, as well as on the DHT coefficient. Adopting Model B as a benchmark, conditions are found under which the validity of the ZDM and Model A as climate sensitivity models holds. It is shown that parameter ranges of physical interest exist for which such validity may not hold. The 2 x CO{sub 2} sensitivities of the simple models are studied and compared. Possible implications of the results for sensitivities derived from GCMs and palaeoclimate data are suggested. Sensitivities for more general scenarios that include negative forcing in the tropics (due to aerosols, inadvertent or geoengineered) are also studied. Some unexpected outcomes are found in this case. These include the possibility of a negative global-mean temperature response to a positive global-mean forcing, and vice versa. (orig.)

  19. CONCEPTUAL MODEL OF CONSUMERS TRUST TO ONLINE SHOPS

    Directory of Open Access Journals (Sweden)

    T. Dubovyk

    2014-06-01

    Full Text Available In the article the conceptual model of the major factors that influence consumers trust in online shop: reliability of online store, reliable information system for making purchases online, factors of ethic interactiveness (security, third-party certification, internet-marketing communications of online-shop and other factors – that is divided enterprises of trade and consumers (demographic variables, psychological perception of internet-marketing communications, experience of purchase of commodities are in the Internet. The degree of individual customer trust propensity which reflects the personality traits, culture and previous experience. An implement signs of consumer confidence due to site elements online shop – graphic design, structured design, design of content, design harmonized with perception of target audience.

  20. Conceptual Models of the Individual Public Service Provider

    DEFF Research Database (Denmark)

    Andersen, Lotte Bøgh; Pedersen, Lene Holm; Bhatti, Yosef

    are used to gain insight on the motivation of public service providers; namely principal-agent theory, self-determination theory and public service motivation theory. We situate the theoretical discussions in the context of public service providers being transferred to private organizations......Individual public service providers’ motivation can be conceptualized as either extrinsic, autonomous or prosocial, and the question is how we can best theoretically understand this complexity without losing too much coherence and parsimony. Drawing on Allison’s approach (1969), three perspectives...... theoretical – to develop a coherent model of individual public service providers – but the empirical illustration also contributes to our understanding of motivation in the context of public sector outsourcing....

  1. CONCEPTUAL MODEL OF INFORMATION SYSTEM OF THE AGRICULTURAL ENTERPRISES

    Directory of Open Access Journals (Sweden)

    Uladzimir Buts

    2017-02-01

    Full Text Available Abstract. Research subject represented by the theoretical and practical issues use of information resources in the agricultural business. Research aim is to formation of a conceptual model of information system of agricultural enterprises according to the requirements of sustainable development. Research methods. The work is prepared on basis of several scientific methods and approaches including monographic, analytical, computational and constructive methods of mathematical and structural logic simulation of information systems. Research results. Based on the assessment of the results of research information systems in agribusiness, as reflected in the theoretical review, the author designed principles of the information system for the agricultural enterprise for sustainable development of agribusiness. Sphere of application of the research results. State and regional authorities of economic regulation. Agricultural enterprises and farmers.

  2. A Framework for Conceptual Modeling of Geographic Data Quality

    DEFF Research Database (Denmark)

    Friis-Christensen, Anders; Christensen, J.V.; Jensen, Christian Søndergaard

    2004-01-01

    Sustained advances in wireless communications, geo-positioning, and consumer electronics pave the way to a kind of location-based service that relies on the tracking of the continuously changing positions of an entire population of service users. This type of service is characterized by large...... an object is moving. Empirical performance studies based on a real road network and GPS logs from cars areThe notion of data quality is of particular importance to geographic data. One reason is that such data is often inherently imprecise. Another is that the usability of the data is in large part...... determined by how "good" the data is, as different applications of geographic data require different qualities of the data are met. Such qualities concern the object level as well as the attribute level of the data. This paper presents a systematic and integrated approach to the conceptual modeling...

  3. Recruiting Transcultural Qualitative Research Participants: A Conceptual Model

    Directory of Open Access Journals (Sweden)

    Phyllis Eide

    2005-06-01

    Full Text Available Working with diverse populations poses many challenges to the qualitative researcher who is a member of the dominant culture. Traditional methods of recruitment and selection (such as flyers and advertisements are often unproductive, leading to missed contributions from potential participants who were not recruited and researcher frustration. In this article, the authors explore recruitment issues related to the concept of personal knowing based on experiences with Aboriginal Hawai'ian and Micronesian populations, wherein knowing and being known are crucial to successful recruitment of participants. They present a conceptual model that incorporates key concepts of knowing the other, cultural context, and trust to guide other qualitative transcultural researchers. They also describe challenges, implications, and concrete suggestions for recruitment of participants.

  4. Hydrochemical tracers in the middle Rio Grande Basin, USA: 1. Conceptualization of groundwater flow

    Science.gov (United States)

    Plummer, L. Niel; Bexfield, Laura M.; Anderholm, Scott K.; Sanford, Ward E.; Busenberg, Eurybiades

    Chemical and isotopic data for groundwater from throughout the Middle Rio Grande Basin, central New Mexico, USA, were used to identify and map groundwater flow from 12 sources of water to the basin, evaluate radiocarbon ages, and refine the conceptual model of the Santa Fe Group aquifer system. Hydrochemical zones, representing groundwater flow over thousands to tens of thousands of years, can be traced over large distances through the primarily siliciclastic aquifer system. The locations of the hydrochemical zones mostly reflect the ``modern'' predevelopment hydraulic-head distribution, but are inconsistent with a trough in predevelopment water levels in the west-central part of the basin, indicating that this trough is a transient rather than a long-term feature of the aquifer system. Radiocarbon ages adjusted for geochemical reactions, mixing, and evapotranspiration/dilution processes in the aquifer system were nearly identical to the unadjusted radiocarbon ages, and ranged from modern to more than 30 ka. Age gradients from piezometer nests ranged from 0.1 to 2 year cm-1 and indicate a recharge rate of about 3 cm year-1 for recharge along the eastern mountain front and infiltration from the Rio Grande near Albuquerque. There has been appreciably less recharge along the eastern mountain front north and south of Albuquerque. Des données sur les éléments chimiques et les isotopes présents dans l'eau souterraine prélevée à divers endroits dans le bassin moyen du Rio Grande, au centre du Nouveau-Mexique (É-U), ont permis de déterminer l'existence et l'étendue de douze sources d'eau régionales dans le bassin, d'évaluer les âges radiocarbones et de raffiner le modèle conceptuel du système aquifère du groupe de Santa Fe. Des zones hydro-chimiques qui représentent l'écoulement de l'eau souterraine depuis des dizaines de milliers d'années peuvent être suivies sur de longues distances à travers l'aquifère principalement siliclastique. La position des

  5. Fatigue in fibromyalgia: a conceptual model informed by patient interviews

    Directory of Open Access Journals (Sweden)

    Humphrey Louise

    2010-09-01

    Full Text Available Abstract Background Fatigue is increasingly recognized as an important symptom in fibromyalgia (FM. Unknown however is how fatigue is experienced by individuals in the context of FM. We conducted qualitative research in order to better understand aspects of fatigue that might be unique to FM as well as the impact it has on patients' lives. The data obtained informed the development of a conceptual model of fatigue in FM. Methods Open-ended interviews were conducted with 40 individuals with FM (US [n = 20], Germany [n = 10] and France [n = 10]. Transcripts were analyzed using qualitative methods based upon grounded theory to identify key themes and concepts. Results Participants were mostly female (70% with a mean age of 48.7 years (range: 25-79. Thirty-one individuals (i.e., 77.5% spontaneously described experiencing tiredness/lack of energy/fatigue due to FM. Participants discussed FM fatigue as being more severe, constant/persistent and unpredictable than normal tiredness. The conceptual model depicts the key elements of fatigue in FM from a patient perspective. This includes: an overwhelming feeling of tiredness (n = 17, 42.5%, not relieved by resting/sleeping (n = 15, 37.5%, not proportional to effort exerted (n = 25, 62.5%, associated with a feeling of weakness/heaviness (n = 20, 50%, interferes with motivation (n = 22, 55%, interferes with desired activities (n = 27, 67.5%, prolongs tasks (n = 15, 37.5%, and makes it difficult to concentrate (n = 21, 52.5%, think clearly (n = 12, 30% or remember things (n = 9, 22.5%. Conclusion The majority of individuals with FM who participated in this study experience fatigue and describe it as more severe than normal tiredness.

  6. Computational modeling of concrete flow

    DEFF Research Database (Denmark)

    Roussel, Nicolas; Geiker, Mette Rica; Dufour, Frederic

    2007-01-01

    particle flow, and numerical techniques allowing the modeling of particles suspended in a fluid. The general concept behind each family of techniques is described. Pros and cons for each technique are given along with examples and references to applications to fresh cementitious materials....

  7. Modeling groundwater flow on MPPs

    International Nuclear Information System (INIS)

    Ashby, S.F.; Falgout, R.D.; Smith, S.G.; Tompson, A.F.B.

    1993-10-01

    The numerical simulation of groundwater flow in three-dimensional heterogeneous porous media is examined. To enable detailed modeling of large contaminated sites, preconditioned iterative methods and massively parallel computing power are combined in a simulator called PARFLOW. After describing this portable and modular code, some numerical results are given, including one that demonstrates the code's scalability

  8. Impact of the calibration period on the conceptual rainfall-runoff model parameter estimates

    Science.gov (United States)

    Todorovic, Andrijana; Plavsic, Jasna

    2015-04-01

    A conceptual rainfall-runoff model is defined by its structure and parameters, which are commonly inferred through model calibration. Parameter estimates depend on objective function(s), optimisation method, and calibration period. Model calibration over different periods may result in dissimilar parameter estimates, while model efficiency decreases outside calibration period. Problem of model (parameter) transferability, which conditions reliability of hydrologic simulations, has been investigated for decades. In this paper, dependence of the parameter estimates and model performance on calibration period is analysed. The main question that is addressed is: are there any changes in optimised parameters and model efficiency that can be linked to the changes in hydrologic or meteorological variables (flow, precipitation and temperature)? Conceptual, semi-distributed HBV-light model is calibrated over five-year periods shifted by a year (sliding time windows). Length of the calibration periods is selected to enable identification of all parameters. One water year of model warm-up precedes every simulation, which starts with the beginning of a water year. The model is calibrated using the built-in GAP optimisation algorithm. The objective function used for calibration is composed of Nash-Sutcliffe coefficient for flows and logarithms of flows, and volumetric error, all of which participate in the composite objective function with approximately equal weights. Same prior parameter ranges are used in all simulations. The model is calibrated against flows observed at the Slovac stream gauge on the Kolubara River in Serbia (records from 1954 to 2013). There are no trends in precipitation nor in flows, however, there is a statistically significant increasing trend in temperatures at this catchment. Parameter variability across the calibration periods is quantified in terms of standard deviations of normalised parameters, enabling detection of the most variable parameters

  9. Assessment of private hospital portals: A conceptual model

    Directory of Open Access Journals (Sweden)

    Mehdi Alipour-Hafezi

    2016-01-01

    Full Text Available Introduction: Hospital portals, as the first virtual entry, play an important role in connecting people with hospital and also presenting hospital virtual services. The main purpose of this article was to suggest a conceptual model to improve Tehran private hospital portals. The suggested model can be used by all the health portals that are in the same circumstances and all the health portals which are in progress. Method: This is a practical research, using evaluative survey research method. Research population includes all the private hospital portals in Tehran, 34 portals, and ten top international hospital portals. Data gathering tool used in this research was a researcher-made checklist including 14 criteria and 77 sub-criteria with their weight score. In fact, objective observation with the mentioned checklist was used to gather information. Descriptive statistics were used to analyze the data and tables and graphs were used to present the organized data. Also, data were analyzed using independent t-test. Conceptual modeling technique was used to design the model and demonstration method was used to evaluate the proposed model. In this regard, SPSS statistical software was used to perform the tests. Results:The comparative study between the two groups of portals, TPH and WTH, in the 14 main criteria showed that the value of t-test in contact information criteria was 0.862, portal page specification was -1.378, page design criteria -1.527, updating pages -0.322, general information and access roads -3.161, public services -7.302, patient services -4.154, patient data -8.703, research and education -9.155, public relationship -3.009, page technical specifications -4.726, telemedicine -7.488, pharmaceutical services -6.183, and financial services -2.782. Finally, the findings demonstrated that Tehran private hospital portals in criterion of contact information were favorable; page design criteria were relatively favorable; page technical

  10. Modelling in Primary School: Constructing Conceptual Models and Making Sense of Fractions

    Science.gov (United States)

    Shahbari, Juhaina Awawdeh; Peled, Irit

    2017-01-01

    This article describes sixth-grade students' engagement in two model-eliciting activities offering students the opportunity to construct mathematical models. The findings show that students utilized their knowledge of fractions including conceptual and procedural knowledge in constructing mathematical models for the given situations. Some students…

  11. A conceptual model for the fuel oxidation of defective fuel

    International Nuclear Information System (INIS)

    Higgs, J.D.; Lewis, B.J.; Thompson, W.T.; He, Z.

    2007-01-01

    A mechanistic conceptual model has been developed to predict the fuel oxidation behaviour in operating defective fuel elements for water-cooled nuclear reactors. This theoretical work accounts for gas-phase transport and sheath reactions in the fuel-to-sheath gap to determine the local oxygen potential. An improved thermodynamic analysis has also been incorporated into the model to describe the equilibrium state of the oxidized fuel. The fuel oxidation kinetics treatment accounts for multi-phase transport including normal diffusion and thermodiffusion for interstitial oxygen migration in the solid, as well as gas-phase transport in the fuel pellet cracks. The fuel oxidation treatment is further coupled to a heat conduction equation. A numerical solution of the coupled transport equations is obtained by a finite-element technique with the FEMLAB 3.1 software package. The model is able to provide radial-axial profiles of the oxygen-to-uranium ratio and the fuel temperatures as a function of time in the defective element for a wide range of element powers and defect sizes. The model results are assessed against coulometric titration measurements of the oxygen-to-metal profile for pellet samples taken from ten spent defective elements discharged from the National Research Universal Reactor at the Chalk River Laboratories and commercial reactors

  12. Internal Models, Vestibular Cognition, and Mental Imagery: Conceptual Considerations.

    Science.gov (United States)

    Mast, Fred W; Ellis, Andrew W

    2015-01-01

    Vestibular cognition has recently gained attention. Despite numerous experimental and clinical demonstrations, it is not yet clear what vestibular cognition really is. For future research in vestibular cognition, adopting a computational approach will make it easier to explore the underlying mechanisms. Indeed, most modeling approaches in vestibular science include a top-down or a priori component. We review recent Bayesian optimal observer models, and discuss in detail the conceptual value of prior assumptions, likelihood and posterior estimates for research in vestibular cognition. We then consider forward models in vestibular processing, which are required in order to distinguish between sensory input that is induced by active self-motion, and sensory input that is due to passive self-motion. We suggest that forward models are used not only in the service of estimating sensory states but they can also be drawn upon in an offline mode (e.g., spatial perspective transformations), in which interaction with sensory input is not desired. A computational approach to vestibular cognition will help to discover connections across studies, and it will provide a more coherent framework for investigating vestibular cognition.

  13. BIM-Enabled Conceptual Modelling and Representation of Building Circulation

    Directory of Open Access Journals (Sweden)

    Jin Kook Lee

    2014-08-01

    Full Text Available This paper describes how a building information modelling (BIM-based approach for building circulation enables us to change the process of building design in terms of its computational representation and processes, focusing on the conceptual modelling and representation of circulation within buildings. BIM has been designed for use by several BIM authoring tools, in particular with the widely known interoperable industry foundation classes (IFCs, which follow an object-oriented data modelling methodology. Advances in BIM authoring tools, using space objects and their relations defined in an IFC's schema, have made it possible to model, visualize and analyse circulation within buildings prior to their construction. Agent-based circulation has long been an interdisciplinary topic of research across several areas, including design computing, computer science, architectural morphology, human behaviour and environmental psychology. Such conventional approaches to building circulation are centred on navigational knowledge about built environments, and represent specific circulation paths and regulations. This paper, however, places emphasis on the use of ‘space objects’ in BIM-enabled design processes rather than on circulation agents, the latter of which are not defined in the IFCs' schemas. By introducing and reviewing some associated research and projects, this paper also surveys how such a circulation representation is applicable to the analysis of building circulation-related rules.

  14. A CONCEPTUAL MODEL OF THE LIFE CYCLE OF THE PROGRAM

    Directory of Open Access Journals (Sweden)

    Марія Костянтинівна СУХОНОС

    2016-02-01

    Full Text Available A conceptual model of the life cycle of the program is proposed. This model is based on the value approach. As a resulting index, it uses a category of complex structural value. This model renders the process of the life cycle of the program in the context of time/result. It assumes the presence of four basic phases of the life cycle, namely, initiation, planning, executing and closing. Also, this model formalizes interconnection of management processes of integration of program and management of its community and subprocesses. Selection of a value approach for the forming of a resulting index of a program determines by a variety of results of the program. This is a result of its variety and complexity in the process of finding a criterion for evaluation. Worked out a mechanism for assessing the value of the program. It consists of four steps and involves using of conventional methods (decomposition and expert estimates. As a unit of measurement assumes to use points and rating scale with the maximum score a hundred points. A complex value, which is evaluated at one hundred points, is a result of the program. It is critically important in the process of current and final evaluation of the program.

  15. Numerical modeling of foam flows

    International Nuclear Information System (INIS)

    Cheddadi, Ibrahim

    2010-01-01

    Liquid foam flows are involved in numerous applications, e.g. food and cosmetics industries, oil extraction, nuclear decontamination. Moreover, their study leads to fundamental knowledge: as it is easier to manipulate and analyse, foam is used as a model material to understand the flow of emulsions, polymers, pastes, or cell aggregates, all of which display both solid and liquid behaviour. Systematic experiments performed by Francois Graner et al. provide precise data that emphasize the non Newtonian properties of the foam. Meanwhile, Pierre Saramito proposed a visco-elasto-plastic continuous tensorial model, akin to predict the behaviour of the foam. The goal of this thesis is to understand this complex behaviour, using these two elements. We have built and validated a resolution algorithm based on a bidimensional finite elements methods. The numerical solutions are in excellent agreement with the spatial distribution of all measured quantities, and confirm the predictive capabilities of the model. The dominant parameters have been identified and we evidenced the fact that the viscous, elastic, and plastic contributions to the flow have to be treated simultaneously in a tensorial formalism. We provide a substantial contribution to the understanding of foams and open the path to realistic simulations of complex VEP flows for industrial applications. (author)

  16. Hydrogeologic framework, hydrology, and refined conceptual model of groundwater flow for Coastal Plain aquifers at the Standard Chlorine of Delaware, Inc. Superfund Site, New Castle County, Delaware, 2005-12

    Science.gov (United States)

    Brayton, Michael J.; Cruz, Roberto M.; Myers, Luke; Degnan, James R.; Raffensperger, Jeff P.

    2015-01-01

    From 1966 to 2002, activities at the Standard Chlorine of Delaware chemical facility in New Castle County, Delaware resulted in the contamination of groundwater, soils, and wetland sediment. In 2005, the U.S. Geological Survey (USGS), in partnership with the U.S. Environmental Protection Agency, Region 3, and the Delaware Department of Natural Resources and Environmental Control began a multi-year investigation of the hydrogeologic framework and hydrology of the confined aquifer system. The goals of the ongoing study at the site (the Potomac Aquifer Study) are to determine the hydraulic connection between the Columbia and Potomac aquifers, determine the direction of groundwater flow in the Potomac aquifer, and identify factors affecting the fate of contaminated groundwater. This report describes progress made towards these goals based on available data collected through September 2012.

  17. Turbulence modelling for incompressible flows

    International Nuclear Information System (INIS)

    Rodi, W.

    1985-12-01

    EUROMECH colloquium 180 was held at Karlsruhe from 4-6 July, 1984, with the aim of bringing together specialists working in the area of turbulence modelling and of reviewing the state-of-the-art in this field. 44 scientists from 12 countries participated and 28 papers were presented. The meeting started with a review of the performance of two-equation turbulence models employing transport equations for both the velocity and the length scale of turbulence. These models are now generally well established, but it was found that their application to certain flow situations remains problematic. The modelling assumptions involved in Reynolds stress-equation models were reviewed next, and new assumptions were proposed. It was generally agreed that, as computing power increases, these more complex models will become more popular also for practical applications. The increase in computing power also allows more and more to resolve the viscous sublayer with low Reynolds numbers models, and the capabilities and problems of these models were discussed. In this connection, special aspects of boundary layer calculations were also discussed, namely those associated with 3D boundary layers, converging and diverging flow and slightly detached boundary layers. The complex physical phenomena prevalent in situations under the influence of buoyancy and rotation were reviewed, and several papers were presented on models for simulating these effects. (orig./HP) [de

  18. The influence of conceptual model uncertainty on management decisions for a groundwater-dependent ecosystem in karst

    DEFF Research Database (Denmark)

    Gondwe, Bibi Ruth Neuman; Merediz-Alonso, Gonzalo; Bauer-Gottwein, Peter

    2011-01-01

    abstractions and pollution threatens the fresh water resource, and consequently the ecosystem integrity of both Sian Ka’an and the adjacent coastal environment. Seven different catchment-scale conceptual models were implemented in a distributed hydrological modelling approach. Equivalent porous medium...... to preserve water resources and maintain ecosystem services. Multiple Model Simulation highlights the impact of model structure uncertainty on management decisions using several plausible conceptual models. Multiple Model Simulation was used for this purpose on the Yucatan Peninsula, which is one of the world......Groundwater management in karst is often based on limited hydrologic understanding of the aquifer. The geologic heterogeneities controlling the water flow are often insufficiently mapped. As karst aquifers are very vulnerable to pollution, groundwater protection and land use management are crucial...

  19. Description and evaluation of a mechanistically based conceptual model for spall

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, F.D.; Knowles, M.K.; Thompson, T.W. [and others

    1997-08-01

    A mechanistically based model for a possible spall event at the WIPP site is developed and evaluated in this report. Release of waste material to the surface during an inadvertent borehole intrusion is possible if future states of the repository include high gas pressure and waste material consisting of fine particulates having low mechanical strength. The conceptual model incorporates the physics of wellbore hydraulics coupled to transient gas flow to the intrusion borehole, and mechanical response of the waste. Degraded waste properties using of the model. The evaluations include both numerical and analytical implementations of the conceptual model. A tensile failure criterion is assumed appropriate for calculation of volumes of waste experiencing fragmentation. Calculations show that for repository gas pressures less than 12 MPa, no tensile failure occurs. Minimal volumes of material experience failure below gas pressure of 14 MPa. Repository conditions dictate that the probability of gas pressures exceeding 14 MPa is approximately 1%. For these conditions, a maximum failed volume of 0.25 m{sup 3} is calculated.

  20. Description and evaluation of a mechanistically based conceptual model for spall

    International Nuclear Information System (INIS)

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

    1997-08-01

    A mechanistically based model for a possible spall event at the WIPP site is developed and evaluated in this report. Release of waste material to the surface during an inadvertent borehole intrusion is possible if future states of the repository include high gas pressure and waste material consisting of fine particulates having low mechanical strength. The conceptual model incorporates the physics of wellbore hydraulics coupled to transient gas flow to the intrusion borehole, and mechanical response of the waste. Degraded waste properties using of the model. The evaluations include both numerical and analytical implementations of the conceptual model. A tensile failure criterion is assumed appropriate for calculation of volumes of waste experiencing fragmentation. Calculations show that for repository gas pressures less than 12 MPa, no tensile failure occurs. Minimal volumes of material experience failure below gas pressure of 14 MPa. Repository conditions dictate that the probability of gas pressures exceeding 14 MPa is approximately 1%. For these conditions, a maximum failed volume of 0.25 m 3 is calculated

  1. Conceptual model for transport processes in the Culebra Dolomite Member, Rustler Formation

    International Nuclear Information System (INIS)

    Holt, R.M.

    1997-08-01

    The Culebra Dolomite Member of the Rustler Formation represents a possible pathway for contaminants from the Waste Isolation Pilot Plant underground repository to the accessible environment. The geologic character of the Culebra is consistent with a double-porosity, multiple-rate model for transport in which the medium is conceptualized as consisting of advective porosity, where solutes are carried by the groundwater flow, and fracture-bounded zones of diffusive porosity, where solutes move through slow advection or diffusion. As the advective travel length or travel time increases, the nature of transport within a double-porosity medium changes. This behavior is important for chemical sorption, because the specific surface area per unit mass of the diffusive porosity is much greater than in the advective porosity. Culebra transport experiments conducted at two different length scales show behavior consistent with a multiple-rate, double-porosity conceptual model for Culebra transport. Tracer tests conducted on intact core samples from the Culebra show no evidence of significant diffusion, suggesting that at the core scale the Culebra can be modeled as a single-porosity medium where only the advective porosity participates in transport. Field tracer tests conducted in the Culebra show strong double-porosity behavior that is best explained using a multiple-rate model

  2. Aerodynamic Modeling of Transonic Aircraft Using Vortex Lattice Coupled with Transonic Small Disturbance for Conceptual Design

    Science.gov (United States)

    Chaparro, Daniel; Fujiwara, Gustavo E. C.; Ting, Eric; Nguyen, Nhan

    2016-01-01

    The need to rapidly scan large design spaces during conceptual design calls for computationally inexpensive tools such as the vortex lattice method (VLM). Although some VLM tools, such as Vorview have been extended to model fully-supersonic flow, VLM solutions are typically limited to inviscid, subcritical flow regimes. Many transport aircraft operate at transonic speeds, which limits the applicability of VLM for such applications. This paper presents a novel approach to correct three-dimensional VLM through coupling of two-dimensional transonic small disturbance (TSD) solutions along the span of an aircraft wing in order to accurately predict transonic aerodynamic loading and wave drag for transport aircraft. The approach is extended to predict flow separation and capture the attenuation of aerodynamic forces due to boundary layer viscosity by coupling the TSD solver with an integral boundary layer (IBL) model. The modeling framework is applied to the NASA General Transport Model (GTM) integrated with a novel control surface known as the Variable Camber Continuous Trailing Edge Flap (VCCTEF).

  3. First status report on regional ground-water flow modeling for Vacherie Dome, Louisiana

    International Nuclear Information System (INIS)

    1986-07-01

    Regional ground-water flow within the principal geohydrologic units in the vicinity of Vacherie Dome, Louisiana is evaluated by developing a conceptual model of the flow regime within these units and testing the model using a three-dimensional, finite-difference flow code (SWENT). Semiquantitative sensitivity analyses (a limited parametric study) are conducted to define the system responses to changes in the conceptual model, particularly in regard to the geohydrologic properties. All steps leading to the final results and conclusions are incorporated in this report. The available data utilized in this study are summarized. The conceptual model is defined in terms of the areal and vertical averaging of lithologic units, aquifer properties, and hydrologic boundary conditions. The simulated ground-water flow fields are described with potentiometric surfaces, areas of upward and downward flow across aquitards, tables summarizing the horizontal and vertical volumetric flows through the principal units, ground-water travel times and paths, and Darcy velocities within specified finite-difference blocks. The reported work is the first stage of an ongoing evaluation of Vacherie Dome as a potential repository for high-level radioactive wastes. The results and conclusions should thus be considered preliminary and subject to modification with the collection of additional data. However, the report does provide a useful basis for describing the sensitivity of the conceptualization of ground-water flow to parameterization and, to a lesser extent, the uncertainties in the present conceptualization. 34 refs., 57 figs., 19 tabs

  4. Testing a Conceptual Change Model Framework for Visual Data

    Science.gov (United States)

    Finson, Kevin D.; Pedersen, Jon E.

    2015-01-01

    An emergent data analysis technique was employed to test the veracity of a conceptual framework constructed around visual data use and instruction in science classrooms. The framework incorporated all five key components Vosniadou (2007a, 2007b) described as existing in a learner's schema: framework theory, presuppositions, conceptual domains,…

  5. A conceptual model of daily water balance following partial clearing from forest to pasture

    Directory of Open Access Journals (Sweden)

    M. A. Bari

    2006-01-01

    Full Text Available A simple conceptual water balance model representing the streamflow generation processes on a daily time step following land use change is presented. The model consists of five stores: (i Dry, Wet and Subsurface Stores for vertical and lateral water flow, (ii a transient Stream zone Store (iii a saturated Goundwater Store. The soil moisture balance in the top soil Dry and Wet Stores are the most important components of the model and characterize the dynamically varying saturated areas responsible for surface runoff, interflow and deep percolation. The Subsurface Store describes the unsaturated soil moisture balance, extraction of percolated water by vegetation and groundwater recharge. The Groundwater Store controls the baseflow to stream (if any and the groundwater contribution to the stream zone saturated areas. The daily model was developed following a downward approach by analysing data from Ernies (control and Lemon (53% cleared catchments in Western Australia and elaborating a monthly model. The daily model performed very well in simulating daily flow generation processes for both catchments. Most of the model parameters were incorporated a priori from catchment attributes such as surface slope, soil depth, porosity, stream length and initial groundwater depth, and some were calibrated by matching the observed and predicted hydrographs. The predicted groundwater depth, and streamflow volumes across all time steps from daily to monthly to annual were in close agreement with observations for both catchments.

  6. Defining the end-point of mastication: A conceptual model.

    Science.gov (United States)

    Gray-Stuart, Eli M; Jones, Jim R; Bronlund, John E

    2017-10-01

    The great risks of swallowing are choking and aspiration of food into the lungs. Both are rare in normal functioning humans, which is remarkable given the diversity of foods and the estimated 10 million swallows performed in a lifetime. Nevertheless, it remains a major challenge to define the food properties that are necessary to ensure a safe swallow. Here, the mouth is viewed as a well-controlled processor where mechanical sensory assessment occurs throughout the occlusion-circulation cycle of mastication. Swallowing is a subsequent action. It is proposed here that, during mastication, temporal maps of interfacial property data are generated, which the central nervous system compares against a series of criteria in order to be sure that the bolus is safe to swallow. To determine these criteria, an engineering hazard analysis tool, alongside an understanding of fluid and particle mechanics, is used to deduce the mechanisms by which food may deposit or become stranded during swallowing. These mechanisms define the food properties that must be avoided. By inverting the thinking, from hazards to ensuring safety, six criteria arise which are necessary for a safe-to-swallow bolus. A new conceptual model is proposed to define when food is safe to swallow during mastication. This significantly advances earlier mouth models. The conceptual model proposed in this work provides a framework of decision-making to define when food is safe to swallow. This will be of interest to designers of dietary foods, foods for dysphagia sufferers and will aid the further development of mastication robots for preparation of artificial boluses for digestion research. It enables food designers to influence the swallow-point properties of their products. For example, a product may be designed to satisfy five of the criteria for a safe-to-swallow bolus, which means the sixth criterion and its attendant food properties define the swallow-point. Alongside other organoleptic factors, these

  7. Towards methodical modelling: Differences between the structure and output dynamics of multiple conceptual models

    Science.gov (United States)

    Knoben, Wouter; Woods, Ross; Freer, Jim

    2016-04-01

    Conceptual hydrologic models consist of a certain arrangement of spatial and temporal dynamics consisting of stores, fluxes and transformation functions, depending on the modeller's choices and intended use. They have the advantages of being computationally efficient, being relatively easy model structures to reconfigure and having relatively low input data demands. This makes them well-suited for large-scale and large-sample hydrology, where appropriately representing the dominant hydrologic functions of a catchment is a main concern. Given these requirements, the number of parameters in the model cannot be too high, to avoid equifinality and identifiability issues. This limits the number and level of complexity of dominant hydrologic processes the model can represent. Specific purposes and places thus require a specific model and this has led to an abundance of conceptual hydrologic models. No structured overview of these models exists and there is no clear method to select appropriate model structures for different catchments. This study is a first step towards creating an overview of the elements that make up conceptual models, which may later assist a modeller in finding an appropriate model structure for a given catchment. To this end, this study brings together over 30 past and present conceptual models. The reviewed model structures are simply different configurations of three basic model elements (stores, fluxes and transformation functions), depending on the hydrologic processes the models are intended to represent. Differences also exist in the inner workings of the stores, fluxes and transformations, i.e. the mathematical formulations that describe each model element's intended behaviour. We investigate the hypothesis that different model structures can produce similar behavioural simulations. This can clarify the overview of model elements by grouping elements which are similar, which can improve model structure selection.

  8. Conceptual Modeling Framework for E-Area PA HELP Infiltration Model Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, J. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-11-30

    A conceptual modeling framework based on the proposed E-Area Low-Level Waste Facility (LLWF) closure cap design is presented for conducting Hydrologic Evaluation of Landfill Performance (HELP) model simulations of intact and subsided cap infiltration scenarios for the next E-Area Performance Assessment (PA).

  9. Hemispheric Asymmetry of Global Warming Explained by a Conceptual Model

    Science.gov (United States)

    Funke, C. S.; Alexeev, V. A.

    2017-12-01

    Polar Amplification, the process of amplified warming at high latitudes, manifests itself differently in the Arctic and Antarctic. Not only is the temperature increase in the Arctic more pronounced than in the Antarctic but the dramatic sea ice decline in the Arctic over the last few decades also contrasts sharply with trendless to weak positive trend of Antarctic sea ice throughout the same period. This asymmetric behavior is often partly attributed to the differences in configuration of continents in the Arctic and Antarctic: the Arctic Ocean is surrounded by land while the Southern Ocean has a continent in the middle. A simple conceptual energy balance model of Budyko-Sellers type, accounting for differences between the Northern and Southern hemispheres, is applied to study the mechanisms of climate sensitivity to a variety of forcings. Asymmetry in major modes of variability is explained using an eigenmode analysis of the linearized model. Negative forcings over Antarctica such as from ozone depletion were found to have an amplified effect on southern hemisphere climate and may be an important cause of the muted warming and slightly positive Antarctic sea ice trend.

  10. Developing a conceptual model for selecting and evaluating online markets

    Directory of Open Access Journals (Sweden)

    Sadegh Feizollahi

    2013-04-01

    Full Text Available There are many evidences, which emphasis on the benefits of using new technologies of information and communication in international business and many believe that E-Commerce can help satisfy customer explicit and implicit requirements. Internet shopping is a concept developed after the introduction of electronic commerce. Information technology (IT and its applications, specifically in the realm of the internet and e-mail promoted the development of e-commerce in terms of advertising, motivating and information. However, with the development of new technologies, credit and financial exchange on the internet websites were constructed so to facilitate e-commerce. The proposed study sends a total of 200 questionnaires to the target group (teachers - students - professionals - managers of commercial web sites and it manages to collect 130 questionnaires for final evaluation. Cronbach's alpha test is used for measuring reliability and to evaluate the validity of measurement instruments (questionnaires, and to assure construct validity, confirmatory factor analysis is employed. In addition, in order to analyze the research questions based on the path analysis method and to determine markets selection models, a regular technique is implemented. In the present study, after examining different aspects of e-commerce, we provide a conceptual model for selecting and evaluating online marketing in Iran. These findings provide a consistent, targeted and holistic framework for the development of the Internet market in the country.

  11. Cognitive balanced model: a conceptual scheme of diagnostic decision making.

    Science.gov (United States)

    Lucchiari, Claudio; Pravettoni, Gabriella

    2012-02-01

    Diagnostic reasoning is a critical aspect of clinical performance, having a high impact on quality and safety of care. Although diagnosis is fundamental in medicine, we still have a poor understanding of the factors that determine its course. According to traditional understanding, all information used in diagnostic reasoning is objective and logically driven. However, these conditions are not always met. Although we would be less likely to make an inaccurate diagnosis when following rational decision making, as described by normative models, the real diagnostic process works in a different way. Recent work has described the major cognitive biases in medicine as well as a number of strategies for reducing them, collectively called debiasing techniques. However, advances have encountered obstacles in achieving implementation into clinical practice. While traditional understanding of clinical reasoning has failed to consider contextual factors, most debiasing techniques seem to fail in raising sound and safer medical praxis. Technological solutions, being data driven, are fundamental in increasing care safety, but they need to consider human factors. Thus, balanced models, cognitive driven and technology based, are needed in day-to-day applications to actually improve the diagnostic process. The purpose of this article, then, is to provide insight into cognitive influences that have resulted in wrong, delayed or missed diagnosis. Using a cognitive approach, we describe the basis of medical error, with particular emphasis on diagnostic error. We then propose a conceptual scheme of the diagnostic process by the use of fuzzy cognitive maps. © 2011 Blackwell Publishing Ltd.

  12. Mass discharge estimation from contaminated sites: Multi-model solutions for assessment of conceptual uncertainty

    DEFF Research Database (Denmark)

    Thomsen, Nanna Isbak; Troldborg, Mads; McKnight, Ursula S.

    2012-01-01

    site. The different conceptual models consider different source characterizations and hydrogeological descriptions. The idea is to include a set of essentially different conceptual models where each model is believed to be realistic representation of the given site, based on the current level...... the appropriate management option. The uncertainty of mass discharge estimates depends greatly on the extent of the site characterization. A good approach for uncertainty estimation will be flexible with respect to the investigation level, and account for both parameter and conceptual model uncertainty. We...... propose a method for quantifying the uncertainty of dynamic mass discharge estimates from contaminant point sources on the local scale. The method considers both parameter and conceptual uncertainty through a multi-model approach. The multi-model approach evaluates multiple conceptual models for the same...

  13. Conceptual Model for Simulating the Adjustments of Bankfull Characteristics in the Lower Yellow River, China

    Directory of Open Access Journals (Sweden)

    Yuanjian Wang

    2014-01-01

    Full Text Available We present a conceptual model for simulating the temporal adjustments in the banks of the Lower Yellow River (LYR. Basic conservation equations for mass, friction, and sediment transport capacity and the Exner equation were adopted to simulate the hydrodynamics underlying fluvial processes. The relationship between changing rates in bankfull width and depth, derived from quasiuniversal hydraulic geometries, was used as a closure for the hydrodynamic equations. On inputting the daily flow discharge and sediment load, the conceptual model successfully simulated the 30-year adjustments in the bankfull geometries of typical reaches of the LYR. The square of the correlating coefficient reached 0.74 for Huayuankou Station in the multiple-thread reach and exceeded 0.90 for Lijin Station in the meandering reach. This proposed model allows multiple dependent variables and the input of daily hydrological data for long-term simulations. This links the hydrodynamic and geomorphic processes in a fluvial river and has potential applicability to fluvial rivers undergoing significant adjustments.

  14. Field studies at the Apache Leap Research Site in support of alternative conceptual models

    Energy Technology Data Exchange (ETDEWEB)

    Woodhouse, E.G.; Davidson, G.R.; Theis, C. [eds.] [and others

    1997-08-01

    This is a final technical report for a project of the U.S Nuclear Regulatory Commission (sponsored contract NRC-04-090-51) with the University of Arizona. The contract was an optional extension that was initiated on July 21, 1994 and that expired on May 31, 1995. The project manager was Thomas J. Nicholson, Office of Nuclear Regulatory Research. The objectives of this contract were to examine hypotheses and conceptual models concerning unsaturated flow and transport through fractured rock, and to design and execute confirmatory field and laboratory experiments to test these hypotheses and conceptual models at the Apache Leap Research Site near Superior, Arizona. The results discussed here are products of specific tasks that address a broad spectrum of issues related to flow and transport through fractures. Each chapter in this final report summarizes research related to a specific set of objectives and can be read and interpreted as a separate entity. The tasks include detection and characterization of historical rapid fluid flow through fractured rock and the relationship to perched water systems using environmental isotopic tracers of {sup 3}H and {sup 14}C, fluid- and rock-derived {sup 2343}U/{sup 238}U measurements, and geophysical data. The water balance in a small watershed at the ALRS demonstrates the methods of acounting for ET, and estimating the quantity of water available for infiltration through fracture networks. Grain density measurements were made for core-sized samples using a newly designed gas pycnometer. The distribution and magnitude of air permeability measurements have been measured in a three-dimensional setting; the subsequent geostatistical analysis is presented. Electronic versions of the data presented here are available from authors; more detailed discussions and analyses are available in technical publications referenced herein, or soon to appear in the professional literature.

  15. Field studies at the Apache Leap Research Site in support of alternative conceptual models

    International Nuclear Information System (INIS)

    Woodhouse, E.G.; Davidson, G.R.; Theis, C.

    1997-08-01

    This is a final technical report for a project of the U.S Nuclear Regulatory Commission (sponsored contract NRC-04-090-51) with the University of Arizona. The contract was an optional extension that was initiated on July 21, 1994 and that expired on May 31, 1995. The project manager was Thomas J. Nicholson, Office of Nuclear Regulatory Research. The objectives of this contract were to examine hypotheses and conceptual models concerning unsaturated flow and transport through fractured rock, and to design and execute confirmatory field and laboratory experiments to test these hypotheses and conceptual models at the Apache Leap Research Site near Superior, Arizona. The results discussed here are products of specific tasks that address a broad spectrum of issues related to flow and transport through fractures. Each chapter in this final report summarizes research related to a specific set of objectives and can be read and interpreted as a separate entity. The tasks include detection and characterization of historical rapid fluid flow through fractured rock and the relationship to perched water systems using environmental isotopic tracers of 3 H and 14 C, fluid- and rock-derived 2343 U/ 238 U measurements, and geophysical data. The water balance in a small watershed at the ALRS demonstrates the methods of acounting for ET, and estimating the quantity of water available for infiltration through fracture networks. Grain density measurements were made for core-sized samples using a newly designed gas pycnometer. The distribution and magnitude of air permeability measurements have been measured in a three-dimensional setting; the subsequent geostatistical analysis is presented. Electronic versions of the data presented here are available from authors; more detailed discussions and analyses are available in technical publications referenced herein, or soon to appear in the professional literature

  16. Dynamic knowledge representation using agent-based modeling: ontology instantiation and verification of conceptual models.

    Science.gov (United States)

    An, Gary

    2009-01-01

    The sheer volume of biomedical research threatens to overwhelm the capacity of individuals to effectively process this information. Adding to this challenge is the multiscale nature of both biological systems and the research community as a whole. Given this volume and rate of generation of biomedical information, the research community must develop methods for robust representation of knowledge in order for individuals, and the community as a whole, to "know what they know." Despite increasing emphasis on "data-driven" research, the fact remains that researchers guide their research using intuitively constructed conceptual models derived from knowledge extracted from publications, knowledge that is generally qualitatively expressed using natural language. Agent-based modeling (ABM) is a computational modeling method that is suited to translating the knowledge expressed in biomedical texts into dynamic representations of the conceptual models generated by researchers. The hierarchical object-class orientation of ABM maps well to biomedical ontological structures, facilitating the translation of ontologies into instantiated models. Furthermore, ABM is suited to producing the nonintuitive behaviors that often "break" conceptual models. Verification in this context is focused at determining the plausibility of a particular conceptual model, and qualitative knowledge representation is often sufficient for this goal. Thus, utilized in this fashion, ABM can provide a powerful adjunct to other computational methods within the research process, as well as providing a metamodeling framework to enhance the evolution of biomedical ontologies.

  17. Fast reactor flow induced vibration with particular reference to PFR and conceptual CDFR design

    Energy Technology Data Exchange (ETDEWEB)

    Collinson, A E [REML, UKAEA, RNPDE, Risley, Warrington (United Kingdom)

    1977-12-01

    This paper describes development work and basic design criteria as applied to vibration induced by fluid flow for the United Kingdom LMFBR programme. Possible harmful effects that could result from excessive vibration levels are highlighted with the associated excitation mechanisms. Instances of flow-induced vibration encountered in development models and in PFR are described. Basic design requirements and the overall philosophy are considered with respect to PFR and notional CDFRs. Ongoing research objectives are outlined giving some insight into the broad strategy involved. Finally, details are given concerning projects presently in progress along with more long term proposals. (author)

  18. Fast reactor flow induced vibration with particular reference to PFR and conceptual CDFR design

    International Nuclear Information System (INIS)

    Collinson, A.E.

    1977-01-01

    This paper describes development work and basic design criteria as applied to vibration induced by fluid flow for the United Kingdom LMFBR programme. Possible harmful effects that could result from excessive vibration levels are highlighted with the associated excitation mechanisms. Instances of flow-induced vibration encountered in development models and in PFR are described. Basic design requirements and the overall philosophy are considered with respect to PFR and notional CDFRs. Ongoing research objectives are outlined giving some insight into the broad strategy involved. Finally, details are given concerning projects presently in progress along with more long term proposals. (author)

  19. The Value of Conceptual Models in Coping with Complexity and Interdisciplinarity in Environmental Sciences Education

    Science.gov (United States)

    Fortuin, Karen P. J.; van Koppen, C. S. A.; Leemans, Rik

    2011-01-01

    Conceptual models are useful for facing the challenges of environmental sciences curriculum and course developers and students. These challenges are inherent to the interdisciplinary and problem-oriented character of environmental sciences curricula. In this article, we review the merits of conceptual models in facing these challenges. These…

  20. A conceptual and calculational model for gas formation from impure calcined plutonium oxides

    International Nuclear Information System (INIS)

    Lyman, John L.; Eller, P. Gary

    2000-01-01

    Safe transport and storage of pure and impure plutonium oxides requires an understanding of processes that may generate or consume gases in a confined storage vessel. We have formulated conceptual and calculational models for gas formation from calcined materials. The conceptual model for impure calcined plutonium oxides is based on the data collected to date

  1. Teacher Emotion Research: Introducing a Conceptual Model to Guide Future Research

    Science.gov (United States)

    Fried, Leanne; Mansfield, Caroline; Dobozy, Eva

    2015-01-01

    This article reports on the development of a conceptual model of teacher emotion through a review of teacher emotion research published between 2003 and 2013. By examining 82 publications regarding teacher emotion, the main aim of the review was to identify how teacher emotion was conceptualised in the literature and develop a conceptual model to…

  2. Non-monotonic reasoning in conceptual modeling and ontology design: A proposal

    CSIR Research Space (South Africa)

    Casini, G

    2013-06-01

    Full Text Available -1 2nd International Workshop on Ontologies and Conceptual Modeling (Onto.Com 2013), Valencia, Spain, 17-21 June 2013 Non-monotonic reasoning in conceptual modeling and ontology design: A proposal Giovanni Casini1 and Alessandro Mosca2 1...

  3. A note on the translation of conceptual data models into description logics: disjointness and covering assumptions

    CSIR Research Space (South Africa)

    Casini, G

    2012-10-01

    Full Text Available possibilities for conceptual data modeling. It also raises the question of how existing conceptual models using ER, UML or ORM could be translated into Description Logics (DLs), a family of logics that have proved to be particularly appropriate for formalizing...

  4. Second status report on regional ground-water flow modeling for the Palo Duro Basin, Texas

    International Nuclear Information System (INIS)

    1986-07-01

    Regional ground-water flow within the principal geohydrologic units of the Palo Duro Basin is evaluated by developing a conceptual model of the flow regime and testing the model using a three-dimensional, finite-difference flow code. Sensitivity analyses (a limited parametric study) are conducted to define the system responses to changes in the conceptual model. Of particular interest are the impacts of salt permeability and potential climatic changes on the system response. The conceptual model is described in terms of its areal and vertical discretization, aquifer properties, fluid properties and hydrologic boundary conditions. The simulated ground-water flow fields are described with potentiometric surfaces, tables summarizing the areal and vertical volumetric flows through the principal units, and Darcy velocities within specified finite-difference blocks. The reported work is the second stage of an ongoing evaluation of the Palo Duro Basin as a potential repository for high-level radioactive wastes. The results and conclusions should thus be considered preliminary and subject to modification with the collection of additional data. However, the report does provide a useful basis for describing the sensitivity of the present conceptualization of ground-water flow to particular parameters and, to a lesser extent, the uncertainties in the present conceptualization. 28 refs., 44 figs., 13 tabs

  5. Stochastic models for turbulent reacting flows

    Energy Technology Data Exchange (ETDEWEB)

    Kerstein, A. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    The goal of this program is to develop and apply stochastic models of various processes occurring within turbulent reacting flows in order to identify the fundamental mechanisms governing these flows, to support experimental studies of these flows, and to further the development of comprehensive turbulent reacting flow models.

  6. Theory analysis of the Dental Hygiene Human Needs Conceptual Model.

    Science.gov (United States)

    MacDonald, L; Bowen, D M

    2017-11-01

    Theories provide a structural knowing about concept relationships, practice intricacies, and intuitions and thus shape the distinct body of the profession. Capturing ways of knowing and being is essential to any professions' practice, education and research. This process defines the phenomenon of the profession - its existence or experience. Theory evaluation is a systematic criterion-based assessment of a specific theory. This study presents a theory analysis of the Dental Hygiene Human Needs Conceptual Model (DH HNCM). Using the Walker and Avant Theory Analysis, a seven-step process, the DH HNCM, was analysed and evaluated for its meaningfulness and contribution to dental hygiene. The steps include the following: (i) investigate the origins; (ii) examine relationships of the theory's concepts; (iii) assess the logic of the theory's structure; (iv) consider the usefulness to practice; (v) judge the generalizability; (vi) evaluate the parsimony; and (vii) appraise the testability of the theory. Human needs theory in nursing and Maslow's Hierarchy of Need Theory prompted this theory's development. The DH HNCM depicts four concepts based on the paradigm concepts of the profession: client, health/oral health, environment and dental hygiene actions, and includes validated eleven human needs that evolved overtime to eight. It is logical, simplistic, allows scientific predictions and testing, and provides a unique lens for the dental hygiene practitioner. With this model, dental hygienists have entered practice, knowing they enable clients to meet their human needs. For the DH HNCM, theory analysis affirmed that the model is reasonable and insightful and adds to the dental hygiene professions' epistemology and ontology. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Conceptual Model As The Tool For Managing Bank Services Quality

    Directory of Open Access Journals (Sweden)

    Kornelija Severović

    2009-07-01

    Full Text Available Quality has become basic factor of economic efficiency and basic principle of business activities of successful organizations. Its consequence is revolution on the area of quality that has comprised all kinds of products and services and so the bank services as well. To understand the present and future needs of clients and to know how to fulfill and try to exceed their expectations is the task of each efficient economy. Therefore, the banks in the developed economies try to re-orientate organizationally, technologically and informatically their business activities placing the client in the core of this business activity. Significant indicators of quality services that banks offer is measured by the waiting time of clients for the offer of the desirable service and the number of clients who give up to enter the bank due to the long waiting queues. Dissatisfied client is the worst work result and business activity of banks. Following the stated, the great effort is made to improve service qualities, which means professionalism and communication of personnel with whom the clients come in contact, and giving punctual and clear information and short waiting period of standing in the lines. The aim of this work is to present and describe the functioning of bank system under the conditions of establishing quality in offering services to clients and to recognize basic guidelines for quality increase in the work of sub branches. Since the banking is very dynamic and complex system, the conceptual model is carried out for the purpose of optimization of the stated quality parameters for the bank business activity; this model, in further research, will serve for the development of simulation model.

  8. Conceptualizing women's attitudes toward condom use with the tripartite model.

    Science.gov (United States)

    Hood, Kristina B; Shook, Natalie J

    2013-01-01

    The Centers for Disease Control and Prevention (2011) estimated that women represent 24% of HIV diagnoses in the United States, with most infections resulting from heterosexual contact. However, consistent condom use is highly effective in preventing the spread of HIV. The current study examined women's attitudes toward condom use and potential inconsistencies related to the conceptualization and measurement of attitudes. Data were collected from October 2009 through March 2010. Researchers included 556 female undergraduate students from the Southeast region of the United States. Exploratory and confirmatory factor analyses were used to determine whether women's condom use attitudes were composed of an affective and a cognitive component. Evidence for a two-factor model of condom use attitudes consisting of an affective and cognitive component was found, with participants reporting slightly negative feelings toward condom use but favorable beliefs about using condoms. Affect accounted for more variance (42%) than cognition (8%) in condom use attitudes. Notably, affect and cognition were differentially associated with past behavior and intentions to use condoms. Understanding the structure of women's attitudes toward using condoms can aid in the creation of appropriate HIV prevention and condom use messaging targeted toward promoting positive attitudes and normative change. Changing women's attitudes in this manner could enhance the effectiveness of condom use interventions.

  9. The Performative Gift: A Feminist Materialist Conceptual Model

    Directory of Open Access Journals (Sweden)

    Jörgen Skågeby

    2013-09-01

    Full Text Available Gifting (or gift-giving is a particularly interesting form of communication that envelops both material and social dimensions. Objects are transformed into gifts through particular socio-material practices. While these practices are, of course, interesting in themselves, this paper will take a step back and revisit attempts to define and theorize the gift as a concept. In a time when the gift economy is often called upon as a potential candidate for more “participatory alternatives to capitalist totality”, particularly in relation to theorizing of labour on and through the Internet, theories of gifting provide an important foundation for discussing the boundaries of alternative futures and economies. So far, little effort has been taken to advance gift theory into a new materialist or posthumanist thinking. In an attempt to take that first step, this paper provides two contributions. First, it highlights how feminist theorizing of the gift comprises interesting forerunners in a new materialist conception of the gift. Second, it explores the analytical traction that can be gained from interlocking theories of the gift, feminist materialism and digital media, the result being a conceptual model that addresses the gift as a form of virtual-digital-material communication.

  10. Facets of private practice nursing: a conceptual model.

    Science.gov (United States)

    Wilson, Anne; Averis, Andrea

    2002-04-01

    This paper critically examines the literature relating to private practice nursing. Particular attention is given to the reasons nurses choose private practice and the major issues involved. A conceptual model has been developed based on this information. Nurses' roles are expanding into different work domains. Private practice nursing is one of the advanced practice options available. It also requires the nurse to develop business knowledge and skills. A literature search was conducted of Pub-Med, Cinahl, Medline and InfoTrac databases using the terms 'private practice', 'nurse entrepreneur', 'nurses in business', Inurse practitioners', 'self-employed nurse', 'advanced practice' and 'clinical nurse specialist'. Further relevant articles were identified from the reference lists of papers detected by this literature search. In addition, conference proceedings were examined for any other material on this topic. A thorough search of the existing literature revealed one unpublished theoretically based study which examined limited aspects of private practice nursing in Victoria. A reasonable number of articles and publications that provided anecdotal and personal accounts of being a nurse in business were identified. This review highlights the need for further theoretically based research in this area of nursing, so as to expand nursing knowledge. Suggestions are given for further research in this topical area. Existing research into private practice nursing is limited and not sufficient to inform changes to policy and nurse education. More research is needed.

  11. Stakeholder Participation in System Change: A New Conceptual Model.

    Science.gov (United States)

    O'Rourke, Tammy; Higuchi, Kathryn S; Hogg, William

    2016-08-01

    A recent change in Canada's primary care system led to the introduction of Nurse Practitioner-Led clinics. The literature suggests that stakeholders can influence system change initiatives. However, very little is known about healthcare stakeholder motivations, particularly stakeholders who are seen as resistors to change. To examine stakeholder participation in the system change process that led to the introduction of the first Nurse Practitioner-Led clinic in Ontario. This single case study included two site visits, semistructured individual tape-recorded interviews, and the examination of relevant public documents. Qualitative content analysis was used to analyze the data. Sixteen individuals from different healthcare sectors and professions participated in the interviews and 20 documents were reviewed. Six key themes emerged from the data. Linking Evidence to Action The findings from the study present a new perspective on stakeholder participation that includes both those who supported the proposed change and those who advocated for a different change. The findings identify stakeholder activities used to shape, share, and protect their visions for system change. The conceptual model presented in this study adds to the understanding of challenges and complexities involved in healthcare system change. Understanding why and how stakeholders participate in change can help healthcare leaders in planning activities to enhance stakeholder involvement in healthcare system change. © 2016 Sigma Theta Tau International.

  12. Calibration of the Site-Scale Saturated Zone Flow Model

    International Nuclear Information System (INIS)

    Zyvoloski, G. A.

    2001-01-01

    The purpose of the flow calibration analysis work is to provide Performance Assessment (PA) with the calibrated site-scale saturated zone (SZ) flow model that will be used to make radionuclide transport calculations. As such, it is one of the most important models developed in the Yucca Mountain project. This model will be a culmination of much of our knowledge of the SZ flow system. The objective of this study is to provide a defensible site-scale SZ flow and transport model that can be used for assessing total system performance. A defensible model would include geologic and hydrologic data that are used to form the hydrogeologic framework model; also, it would include hydrochemical information to infer transport pathways, in-situ permeability measurements, and water level and head measurements. In addition, the model should include information on major model sensitivities. Especially important are those that affect calibration, the direction of transport pathways, and travel times. Finally, if warranted, alternative calibrations representing different conceptual models should be included. To obtain a defensible model, all available data should be used (or at least considered) to obtain a calibrated model. The site-scale SZ model was calibrated using measured and model-generated water levels and hydraulic head data, specific discharge calculations, and flux comparisons along several of the boundaries. Model validity was established by comparing model-generated permeabilities with the permeability data from field and laboratory tests; by comparing fluid pathlines obtained from the SZ flow model with those inferred from hydrochemical data; and by comparing the upward gradient generated with the model with that observed in the field. This analysis is governed by the Office of Civilian Radioactive Waste Management (OCRWM) Analysis and Modeling Report (AMR) Development Plan ''Calibration of the Site-Scale Saturated Zone Flow Model'' (CRWMS M and O 1999a)

  13. Online traffic flow model applying dynamic flow-density relation

    International Nuclear Information System (INIS)

    Kim, Y.

    2002-01-01

    This dissertation describes a new approach of the online traffic flow modelling based on the hydrodynamic traffic flow model and an online process to adapt the flow-density relation dynamically. The new modelling approach was tested based on the real traffic situations in various homogeneous motorway sections and a motorway section with ramps and gave encouraging simulation results. This work is composed of two parts: first the analysis of traffic flow characteristics and second the development of a new online traffic flow model applying these characteristics. For homogeneous motorway sections traffic flow is classified into six different traffic states with different characteristics. Delimitation criteria were developed to separate these states. The hysteresis phenomena were analysed during the transitions between these traffic states. The traffic states and the transitions are represented on a states diagram with the flow axis and the density axis. For motorway sections with ramps the complicated traffic flow is simplified and classified into three traffic states depending on the propagation of congestion. The traffic states are represented on a phase diagram with the upstream demand axis and the interaction strength axis which was defined in this research. The states diagram and the phase diagram provide a basis for the development of the dynamic flow-density relation. The first-order hydrodynamic traffic flow model was programmed according to the cell-transmission scheme extended by the modification of flow dependent sending/receiving functions, the classification of cells and the determination strategy for the flow-density relation in the cells. The unreasonable results of macroscopic traffic flow models, which may occur in the first and last cells in certain conditions are alleviated by applying buffer cells between the traffic data and the model. The sending/receiving functions of the cells are determined dynamically based on the classification of the

  14. Maintaining Sexual Desire in Long-Term Relationships: A Systematic Review and Conceptual Model.

    Science.gov (United States)

    Mark, Kristen P; Lasslo, Julie A

    The most universally experienced sexual response is sexual desire. Though research on this topic has increased in recent years, low and high desire are still problematized in clinical settings and the broader culture. However, despite knowledge that sexual desire ebbs and flows both within and between individuals, and that problems with sexual desire are strongly linked to problems with relationships, there is a critical gap in understanding the factors that contribute to maintaining sexual desire in the context of relationships. This article offers a systematic review of the literature to provide researchers, educators, clinicians, and the broader public with an overview and a conceptual model of nonclinical sexual desire in long-term relationships. First, we systematically identified peer-reviewed, English-language articles that focused on the maintenance of sexual desire in the context of nonclinical romantic relationships. Second, we reviewed a total of 64 articles that met inclusion criteria and synthesized them into factors using a socioecological framework categorized as individual, interpersonal, and societal in nature. These findings are used to build a conceptual model of maintaining sexual desire in long-term relationships. Finally, we discuss the limitations of the existing research and suggest clear directions for future research.

  15. Hydrogeochemical evidence supporting models for groundwater flow around Sellafield, U.K

    International Nuclear Information System (INIS)

    Metcalfe, R.; Milodowski, A.E.; Noy, D.J.

    1999-01-01

    Recently, United Kingdom Nirex Limited has investigated a site near Sellafield, north-west England to assess its suitability as the potential location for a deep underground repository for the disposal of intermediate- level, and some low-level, solid radioactive waste. Groundwater flow at the site was simulated using a variety of computer codes, based upon conceptual models of the hydrogeological system. Chemical data for groundwaters aided the development of these conceptual models, and also provided a check upon the computer models' validity. Mineralogical information can be accommodated within the conceptual and theoretical framework. The results of the investigation are presented. (author)

  16. Conceptual model for regional radionuclide transport from a basalt repository site. Final draft, technical memorandum

    Energy Technology Data Exchange (ETDEWEB)

    Walton, W.C.; Voorhees, M.L.; Prickett, T.A.

    1980-05-23

    This technical memorandum was prepared to: (1) describe a typical basalt radionuclide repository site, (2) describe geologic and hydrologic processes associated with regional radionuclide transport in basalts, (3) define the parameters required to model regional radionuclide transport from a basalt repository site, and (4) develop a ''conceptual model'' of radionuclide transport from a basalt repository site. In a general hydrological sense, basalts may be described as layered sequences of aquifers and aquitards. The Columbia River Basalt, centered near the semi-arid Pasco Basin, is considered by many to be typical basalt repository host rock. Detailed description of the flow system including flow velocities with high-low hydraulic conductivity sequences are not possible with existing data. However, according to theory, waste-transport routes are ultimately towards the Columbia River and the lengths of flow paths from the repository to the biosphere may be relatively short. There are many physical, chemical, thermal, and nuclear processes with associated parameters that together determine the possible pattern of radionuclide migration in basalts and surrounding formations. Brief process descriptions and associated parameter lists are provided. Emphasis has been placed on the use of the distribution coefficient in simulating ion exchange. The use of the distribution coefficient approach is limited because it takes into account only relatively fast mass transfer processes. In general, knowledge of hydrogeochemical processes is primitive.

  17. Conceptual model for regional radionuclide transport from a basalt repository site. Final draft, technical memorandum

    International Nuclear Information System (INIS)

    Walton, W.C.; Voorhees, M.L.; Prickett, T.A.

    1980-01-01

    This technical memorandum was prepared to: (1) describe a typical basalt radionuclide repository site, (2) describe geologic and hydrologic processes associated with regional radionuclide transport in basalts, (3) define the parameters required to model regional radionuclide transport from a basalt repository site, and (4) develop a ''conceptual model'' of radionuclide transport from a basalt repository site. In a general hydrological sense, basalts may be described as layered sequences of aquifers and aquitards. The Columbia River Basalt, centered near the semi-arid Pasco Basin, is considered by many to be typical basalt repository host rock. Detailed description of the flow system including flow velocities with high-low hydraulic conductivity sequences are not possible with existing data. However, according to theory, waste-transport routes are ultimately towards the Columbia River and the lengths of flow paths from the repository to the biosphere may be relatively short. There are many physical, chemical, thermal, and nuclear processes with associated parameters that together determine the possible pattern of radionuclide migration in basalts and surrounding formations. Brief process descriptions and associated parameter lists are provided. Emphasis has been placed on the use of the distribution coefficient in simulating ion exchange. The use of the distribution coefficient approach is limited because it takes into account only relatively fast mass transfer processes. In general, knowledge of hydrogeochemical processes is primitive

  18. Testing alternative conceptual models of seawater intrusion in a coastal aquifer using computer simulation, southern California, USA

    Science.gov (United States)

    Nishikawa, Tracy

    1997-01-01

    Two alternative conceptual models of the physical processes controlling seawater intrusion in a coastal basin in California, USA, were tested to identify a likely principal pathway for seawater intrusion. The conceptual models were tested by using a two-dimensional, finite-element groundwater flow and transport model. This pathway was identified by the conceptual model that best replicated the historical data. The numerical model was applied in cross section to a submarine canyon that is a main avenue for seawater to enter the aquifer system underlying the study area. Both models are characterized by a heterogeneous, layered, water-bearing aquifer. However, the first model is characterized by flat-lying aquifer layers and by a high value of hydraulic conductivity in the basal aquifer layer, which is thought to be a principal conduit for seawater intrusion. The second model is characterized by offshore folding, which was modeled as a very nearshore outcrop, thereby providing a shorter path for seawater to intrude. General conclusions are that: 1) the aquifer system is best modeled as a flat, heterogeneous, layered system; 2) relatively thin basal layers with relatively high values of hydraulic conductivity are the principal pathways for seawater intrusion; and 3) continuous clay layers of low hydraulic conductivity play an important role in controlling the movement of seawater.

  19. A conceptual model for the growth, persistence, and blooming behavior of the benthic mat-forming diatom Didymosphenia geminata (Invited)

    Science.gov (United States)

    Cullis, J. D.; Gillis, C.; Bothwell, M.; Kilroy, C.; Packman, A. I.; Hassan, M. A.

    2010-12-01

    The nuisance diatom Didymosphenia geminata (didymo) presents an ecological paradox. How can this benthic algae produce such large amounts of biomass in cold, fast flowing, low nutrient streams? The aim of this paper is to present a conceptual model for the growth, persistence, and blooming behavior of this benthic mat-forming diatom that may help to explain this paradox. The conceptual model highlights the importance of distinguishing between mat thickness and cell growth. It presents evidence gathered from a range of existing studies around the world to support the proposed relationship between growth and light, nutrients and temperature as well as the importance of flood events and bed disturbance in mat removal. It is anticipated that this conceptual model will not only help in identifying the key controlling variables and set a framework for future studies but also support the future management of this nuisance algae. Summary of the conceptual model for didymo growth showing the proposed relationships for the growth of cells and mats with nutrients, radiation and water temperature and the dependence of removal on bed shear stress and the potential for physical bed disturbance.

  20. Global scale groundwater flow model

    Science.gov (United States)

    Sutanudjaja, Edwin; de Graaf, Inge; van Beek, Ludovicus; Bierkens, Marc

    2013-04-01

    As the world's largest accessible source of freshwater, groundwater plays vital role in satisfying the basic needs of human society. It serves as a primary source of drinking water and supplies water for agricultural and industrial activities. During times of drought, groundwater sustains water flows in streams, rivers, lakes and wetlands, and thus supports ecosystem habitat and biodiversity, while its large natural storage provides a buffer against water shortages. Yet, the current generation of global scale hydrological models does not include a groundwater flow component that is a crucial part of the hydrological cycle and allows the simulation of groundwater head dynamics. In this study we present a steady-state MODFLOW (McDonald and Harbaugh, 1988) groundwater model on the global scale at 5 arc-minutes resolution. Aquifer schematization and properties of this groundwater model were developed from available global lithological model (e.g. Dürr et al., 2005; Gleeson et al., 2010; Hartmann and Moorsdorff, in press). We force the groundwtaer model with the output from the large-scale hydrological model PCR-GLOBWB (van Beek et al., 2011), specifically the long term net groundwater recharge and average surface water levels derived from routed channel discharge. We validated calculated groundwater heads and depths with available head observations, from different regions, including the North and South America and Western Europe. Our results show that it is feasible to build a relatively simple global scale groundwater model using existing information, and estimate water table depths within acceptable accuracy in many parts of the world.

  1. Particle hopping vs. fluid-dynamical models for traffic flow

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, K.

    1995-12-31

    Although particle hopping models have been introduced into traffic science in the 19509, their systematic use has only started recently. Two reasons for this are, that they are advantageous on modem computers, and that recent theoretical developments allow analytical understanding of their properties and therefore more confidence for their use. In principle, particle hopping models fit between microscopic models for driving and fluiddynamical models for traffic flow. In this sense, they also help closing the conceptual gap between these two. This paper shows connections between particle hopping models and traffic flow theory. It shows that the hydrodynamical limits of certain particle hopping models correspond to the Lighthill-Whitham theory for traffic flow, and that only slightly more complex particle hopping models produce already the correct traffic jam dynamics, consistent with recent fluid-dynamical models for traffic flow. By doing so, this paper establishes that, on the macroscopic level, particle hopping models are at least as good as fluid-dynamical models. Yet, particle hopping models have at least two advantages over fluid-dynamical models: they straightforwardly allow microscopic simulations, and they include stochasticity.

  2. A conceptual precipitation-runoff modeling suite: Model selection, calibration and predictive uncertainty assessment

    Science.gov (United States)

    Tyler Jon Smith

    2008-01-01

    In Montana and much of the Rocky Mountain West, the single most important parameter in forecasting the controls on regional water resources is snowpack. Despite the heightened importance of snowpack, few studies have considered the representation of uncertainty in coupled snowmelt/hydrologic conceptual models. Uncertainty estimation provides a direct interpretation of...

  3. ITE CHARACTERIZATION TO SUPPORT CONCEPTUAL MODEL DEVELOPMENT FOR SUBSURFACE RADIONUCLIDE TRANSPORT

    Science.gov (United States)

    Remediation of radionuclide contaminants in ground water often begins with the development of conceptual and analytical models that guide our understanding of the processes controlling radionuclide transport. The reliability of these models is often predicated on the collection o...

  4. Modeling flow and transport pathways to the potential repository horizon at Yucca Mountain

    International Nuclear Information System (INIS)

    Wolfsberg, A.V.; Roemer, G.J.C.; Fabryka-Martin, J.T.; Robinson, B.A.

    1998-01-01

    The isotopic ratios of 36 Cl/Cl are used in conjunction with geologic interpretation and numerical modeling to evaluate flow and transport pathways, processes, and model parameters in the unsaturated zone at Yucca Mountain. By synthesizing geochemical and geologic data, the numerical model results provide insight into the validity of alternative hydrologic parameter sets, flow and transport processes in and away from fault zones, and the applicability of 36 Cl/Cl ratios for evaluating alternative conceptual models

  5. Regional ground-water flow modeling for the Paradox Basin, Utah: Second status report

    International Nuclear Information System (INIS)

    1986-09-01

    Regional ground-water flow within the principal geohydrologic units of the Paradox Basin is evaluated by developing a conceptual model of the flow regime between the shallow aquifers, the Paradox salt and the deep-basin brine aquifers. This model is tested using a three-dimensional, finite-difference flow code. Sensitivity analyses (a limited parametric study) are conducted to define the system responses to changes in the conceptual model. The conceptual model is described in terms of its areal and vertical discretization, aquifer properties, fluid properties, and hydrologic boundary conditions. The simulated results are described with potentiometric surfaces, tables summarizing the areal and vertical volumetric flows through the principal units, and Darcy velocities at specified points. The reported work is the second stage of an ongoing evaluation of the Gisbon Dome area within the Paradox Basin as a potential repository for high-level radioactive wastes. The results and conclusions should thus be considered preliminary and subject to modification with the collection of additional data. However, the report does provide a useful basis for describing the sensitivity of the present conceptualization of ground-water flow to the hydrologic parameters and, to a lesser extent, the uncertainties of the present conceptualization. 20 refs., 17 figs., 9 tabs

  6. Predictions of hydraulic and transport behavior in a granite fracture via coupled mechano-chemo conceptual model

    International Nuclear Information System (INIS)

    Yasuhara, Hideaki; Kinoshita, Naoki; Lee, Dae Sung; Nakashima, Shinichiro; Kishida, Kiyoshi

    2009-01-01

    A conceptual model, accounting for pressure and free-face dissolutions, is presented to follow the evolution of fracture permeability in granite that was observed in a flow-through experiment. This model addresses the two dissolution processes at contacting asperities and free walls within fractures, and also describes the multi-mineral dissolution behavior, showing a capability that the evolution of fracture aperture (or related permeability) may be followed with time under an arbitrary temperature and pressure conditions. Predictions utilizing the model proposed in this study show a relatively good agreement with the experimental measurements, although the concentrations predicted underestimate the actual. (author)

  7. Conceptual model and evaluation of generated power and emissions in an IGCC plant

    International Nuclear Information System (INIS)

    Perez-Fortes, M.; Bojarski, A.D.; Velo, E.; Nougues, J.M.; Puigjaner, L.

    2009-01-01

    This work develops a design and operation support tool for an Integrated Gasification Combined Cycle (IGCC) power plant, which allows the efficiency and environmental issues of alternative process designs and feedstock to be assessed. The study is based on a conceptual model of an IGCC plant, validated with data from the ELCOGAS power plant in Spain. The layout of the model includes an Air Separation Unit (ASU), a Pressurized Entrained Flow (PRENFLO) gasifier, a series of purification gas units (venturi scrubber, sour water steam stripper, COS hydrolysis reactor, MDEA absorber columns and a sulphur recovery Claus plant), a Heat Recovery Steam Generator (HRSG) and a Combined Cycle (CC) system. It comprises steady state models. One of the purposes of this work is to analyze the feasibility of coal co-gasification using waste materials; specifically petcoke and olive pomace (orujillo) are considered here. The model has been developed in Aspen Hysys. It uses electrolyte models that have been implemented in Aspen Plus which are connected to Aspen Hysys by means of Artificial Neural Networks (ANNs) models. Results of the model's, gas composition and generated power, are in agreement with the industrial data.

  8. Conceptual model and evaluation of generated power and emissions in an IGCC plant

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Fortes, M.; Bojarski, A. D.; Velo, E.; Nougues, J. M. [Department of Chemical Engineering, Universitat Politecnica de Catalunya, ETSEIB, Avda. Diagonal, 647, E-08028 Barcelona (Spain); Puigjaner, L., E-mail: luis.puigjaner@upc.edu [Department of Chemical Engineering, Universitat Politecnica de Catalunya, ETSEIB, Avda. Diagonal, 647, E-08028 Barcelona (Spain)

    2009-10-15

    This work develops a design and operation support tool for an Integrated Gasification Combined Cycle (IGCC) power plant, which allows the efficiency and environmental issues of alternative process designs and feedstock to be assessed. The study is based on a conceptual model of an IGCC plant, validated with data from the ELCOGAS power plant in Spain. The layout of the model includes an Air Separation Unit (ASU), a Pressurized Entrained Flow (PRENFLO) gasifier, a series of purification gas units (venturi scrubber, sour water steam stripper, COS hydrolysis reactor, MDEA absorber columns and a sulphur recovery Claus plant), a Heat Recovery Steam Generator (HRSG) and a Combined Cycle (CC) system. It comprises steady state models. One of the purposes of this work is to analyze the feasibility of coal co-gasification using waste materials; specifically petcoke and olive pomace (orujillo) are considered here. The model has been developed in Aspen Hysys. It uses electrolyte models that have been implemented in Aspen Plus which are connected to Aspen Hysys by means of Artificial Neural Networks (ANNs) models. Results of the model's, gas composition and generated power, are in agreement with the industrial data.

  9. Conceptual model and evaluation of generated power and emissions in an IGCC plant

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Fortes, M; Bojarski, A D; Velo, E; Nougues, J M; Puigjaner, L [Department of Chemical Engineering, Universitat Politecnica de Catalunya, ETSEIB, Avda. Diagonal, 647, E-08028 Barcelona (Spain)

    2009-10-15

    This work develops a design and operation support tool for an Integrated Gasification Combined Cycle (IGCC) power plant, which allows the efficiency and environmental issues of alternative process designs and feedstock to be assessed. The study is based on a conceptual model of an IGCC plant, validated with data from the ELCOGAS power plant in Spain. The layout of the model includes an Air Separation Unit (ASU), a Pressurized Entrained Flow (PRENFLO) gasifier, a series of purification gas units (venturi scrubber, sour water steam stripper, COS hydrolysis reactor, MDEA absorber columns and a sulphur recovery Claus plant), a Heat Recovery Steam Generator (HRSG) and a Combined Cycle (CC) system. It comprises steady state models. One of the purposes of this work is to analyze the feasibility of coal co-gasification using waste materials; specifically petcoke and olive pomace (orujillo) are considered here. The model has been developed in Aspen Hysys. It uses electrolyte models that have been implemented in Aspen Plus which are connected to Aspen Hysys by means of Artificial Neural Networks (ANNs) models. Results of the model's, gas composition and generated power, are in agreement with the industrial data. (author)

  10. Conceptual model and evaluation of generated power and emissions in an IGCC plant

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Fortes, M.; Bojarski, A.D.; Velo, E.; Nougues, J.M.; Puigjaner, L. [Department of Chemical Engineering, Universitat Politecnica de Catalunya, ETSEIB, Avda. Diagonal, 647, E-08028 Barcelona (Spain)

    2009-10-15

    This work develops a design and operation support tool for an Integrated Gasification Combined Cycle (IGCC) power plant, which allows the efficiency and environmental issues of alternative process designs and feedstock to be assessed. The study is based on a conceptual model of an IGCC plant, validated with data from the ELCOGAS power plant in Spain. The layout of the model includes an Air Separation Unit (ASU), a Pressurized Entrained Flow (PRENFLO) gasifier, a series of purification gas units (venturi scrubber, sour water steam stripper, COS hydrolysis reactor, MDEA absorber columns and a sulphur recovery Claus plant), a Heat Recovery Steam Generator (HRSG) and a Combined Cycle (CC) system. It comprises steady state models. One of the purposes of this work is to analyze the feasibility of coal co-gasification using waste materials; specifically petcoke and olive pomace (orujillo) are considered here. The model has been developed in Aspen Hysys. It uses electrolyte models that have been implemented in Aspen Plus which are connected to Aspen Hysys by means of Artificial Neural Networks (ANNs) models. Results of the model's, gas composition and generated power, are in agreement with the industrial data. (author)

  11. A conceptual modeling framework for discrete event simulation using hierarchical control structures.

    Science.gov (United States)

    Furian, N; O'Sullivan, M; Walker, C; Vössner, S; Neubacher, D

    2015-08-01

    Conceptual Modeling (CM) is a fundamental step in a simulation project. Nevertheless, it is only recently that structured approaches towards the definition and formulation of conceptual models have gained importance in the Discrete Event Simulation (DES) community. As a consequence, frameworks and guidelines for applying CM to DES have emerged and discussion of CM for DES is increasing. However, both the organization of model-components and the identification of behavior and system control from standard CM approaches have shortcomings that limit CM's applicability to DES. Therefore, we discuss the different aspects of previous CM frameworks and identify their limitations. Further, we present the Hierarchical Control Conceptual Modeling framework that pays more attention to the identification of a models' system behavior, control policies and dispatching routines and their structured representation within a conceptual model. The framework guides the user step-by-step through the modeling process and is illustrated by a worked example.

  12. Assessing the relative importance of parameter and forcing uncertainty and their interactions in conceptual hydrological model simulations

    Science.gov (United States)

    Mockler, E. M.; Chun, K. P.; Sapriza-Azuri, G.; Bruen, M.; Wheater, H. S.

    2016-11-01

    Predictions of river flow dynamics provide vital information for many aspects of water management including water resource planning, climate adaptation, and flood and drought assessments. Many of the subjective choices that modellers make including model and criteria selection can have a significant impact on the magnitude and distribution of the output uncertainty. Hydrological modellers are tasked with understanding and minimising the uncertainty surrounding streamflow predictions before communicating the overall uncertainty to decision makers. Parameter uncertainty in conceptual rainfall-runoff models has been widely investigated, and model structural uncertainty and forcing data have been receiving increasing attention. This study aimed to assess uncertainties in streamflow predictions due to forcing data and the identification of behavioural parameter sets in 31 Irish catchments. By combining stochastic rainfall ensembles and multiple parameter sets for three conceptual rainfall-runoff models, an analysis of variance model was used to decompose the total uncertainty in streamflow simulations into contributions from (i) forcing data, (ii) identification of model parameters and (iii) interactions between the two. The analysis illustrates that, for our subjective choices, hydrological model selection had a greater contribution to overall uncertainty, while performance criteria selection influenced the relative intra-annual uncertainties in streamflow predictions. Uncertainties in streamflow predictions due to the method of determining parameters were relatively lower for wetter catchments, and more evenly distributed throughout the year when the Nash-Sutcliffe Efficiency of logarithmic values of flow (lnNSE) was the evaluation criterion.

  13. Development of numerical Grids for UZ Flow and Transport Modeling

    International Nuclear Information System (INIS)

    P. Dobson

    2004-01-01

    This report describes the methods used to develop numerical grids of the unsaturated hydrogeologic system beneath Yucca Mountain, Nevada. Numerical grid generation is an integral part of the development of the unsaturated zone (UZ) flow and transport model, a complex, three-dimensional (3-D) model of Yucca Mountain. This revision contains changes made to improve the clarity of the description of grid generation. The numerical grids, developed using current geologic, hydrogeologic, and mineralogic data, provide the necessary framework to: (1) develop calibrated hydrogeologic property sets and flow fields, (2) test conceptual hypotheses of flow and transport, and (3) predict flow and transport behavior under a variety of climatic and thermal-loading conditions. The technical scope, content, and management for the current revision of this report are described in the planning document ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 2). Grids generated and documented in this report supersede those documented in Revision 00 of this report, ''Development of Numerical Grids for UZ Flow and Transport Modeling'' (BSC 2001 [DIRS 159356]). The grids presented in this report are the same as those developed in Revision 01 (BSC 2003 [DIRS 160109]); however, the documentation of the development of the grids in Revision 02 has been updated to address technical inconsistencies and achieve greater transparency, readability, and traceability. The constraints, assumptions, and limitations associated with this report are discussed in the appropriate sections that follow

  14. Using Multilevel Modeling in Language Assessment Research: A Conceptual Introduction

    Science.gov (United States)

    Barkaoui, Khaled

    2013-01-01

    This article critiques traditional single-level statistical approaches (e.g., multiple regression analysis) to examining relationships between language test scores and variables in the assessment setting. It highlights the conceptual, methodological, and statistical problems associated with these techniques in dealing with multilevel or nested…

  15. Collective (Team) Learning Process Models: A Conceptual Review

    Science.gov (United States)

    Knapp, Randall

    2010-01-01

    Teams have become a key resource for learning and accomplishing work in organizations. The development of collective learning in specific contexts is not well understood, yet has become critical to organizational success. The purpose of this conceptual review is to inform human resource development (HRD) practice about specific team behaviors and…

  16. Mapping the Territory: A Conceptual Model of Scholastic Journalism.

    Science.gov (United States)

    Arnold, Mary

    Intended to provide a comprehensive conceptual framework to serve as a scaffold for past, present, and future research on "scholastic journalism" (journalism in the secondary school), a topical content analysis of the Association for Education in Journalism and Mass Communication (AEJMC) Secondary Education Division research, teaching,…

  17. A conceptual modeling framework for discrete event simulation using hierarchical control structures

    Science.gov (United States)

    Furian, N.; O’Sullivan, M.; Walker, C.; Vössner, S.; Neubacher, D.

    2015-01-01

    Conceptual Modeling (CM) is a fundamental step in a simulation project. Nevertheless, it is only recently that structured approaches towards the definition and formulation of conceptual models have gained importance in the Discrete Event Simulation (DES) community. As a consequence, frameworks and guidelines for applying CM to DES have emerged and discussion of CM for DES is increasing. However, both the organization of model-components and the identification of behavior and system control from standard CM approaches have shortcomings that limit CM’s applicability to DES. Therefore, we discuss the different aspects of previous CM frameworks and identify their limitations. Further, we present the Hierarchical Control Conceptual Modeling framework that pays more attention to the identification of a models’ system behavior, control policies and dispatching routines and their structured representation within a conceptual model. The framework guides the user step-by-step through the modeling process and is illustrated by a worked example. PMID:26778940

  18. New Conceptual Model for Soil Treatment Units: Formation of Multiple Hydraulic Zones during Unsaturated Wastewater Infiltration.

    Science.gov (United States)

    Geza, Mengistu; Lowe, Kathryn S; Huntzinger, Deborah N; McCray, John E

    2013-07-01

    Onsite wastewater treatment systems are commonly used in the United States to reclaim domestic wastewater. A distinct biomat forms at the infiltrative surface, causing resistance to flow and decreasing soil moisture below the biomat. To simulate these conditions, previous modeling studies have used a two-layer approach: a thin biomat layer (1-5 cm thick) and the native soil layer below the biomat. However, the effect of wastewater application extends below the biomat layer. We used numerical modeling supported by experimental data to justify a new conceptual model that includes an intermediate zone (IZ) below the biomat. The conceptual model was set up using Hydrus 2D and calibrated against soil moisture and water flux measurements. The estimated hydraulic conductivity value for the IZ was between biomat and the native soil. The IZ has important implications for wastewater treatment. When the IZ was not considered, a loading rate of 5 cm d resulted in an 8.5-cm ponding. With the IZ, the same loading rate resulted in a 9.5-cm ponding. Without the IZ, up to 3.1 cm d of wastewater could be applied without ponding; with the IZ, only up to 2.8 cm d could be applied without ponding. The IZ also plays a significant role in soil moisture distribution. Without the IZ, near-saturation conditions were observed only within the biomat, whereas near-saturation conditions extended below the biomat with the IZ. Accurate prediction of ponding is important to prevent surfacing of wastewater. The degree of water and air saturation influences pollutant treatment efficiency through residence time, volatility, and biochemical reactions. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  19. MARKET ENTRY STRATEGIES TO EMERGING MARKETS: A CONCEPTUAL MODEL OF TURNKEY PROJECT DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Bistra Vassileva

    2016-11-01

    Full Text Available The main purpose of the paper is to analyse the international market entry strategies in the light of globalisation processes and to propose a conceptual model of turnkey projects as market entry mode. The specific research objectives are as follows: 1. to develop an integrated framework of the turnkey marketing process as a conceptual model; 2. to analyse BRICS countries as potential host countries for turnkey projects implementation; 3. to assess potential implications of proposed conceptual model for global market entry decisions.

  20. A participative and facilitative conceptual modelling framework for discrete event simulation studies in healthcare

    OpenAIRE

    Kotiadis, Kathy; Tako, Antuela; Vasilakis, Christos

    2014-01-01

    Existing approaches to conceptual modelling (CM) in discrete-event simulation do not formally support the participation of a group of stakeholders. Simulation in healthcare can benefit from stakeholder participation as it makes possible to share multiple views and tacit knowledge from different parts of the system. We put forward a framework tailored to healthcare that supports the interaction of simulation modellers with a group of stakeholders to arrive at a common conceptual model. The fra...

  1. An Empirical Review of the Connection Between Model Viewer Characteristics and the Comprehension of Conceptual Process Models

    NARCIS (Netherlands)

    Mendling, Jan; Recker, Jan; Reijers, Hajo A.; Leopold, Henrik

    2018-01-01

    Understanding conceptual models of business domains is a key skill for practitioners tasked with systems analysis and design. Research in this field predominantly uses experiments with specific user proxy cohorts to examine factors that explain how well different types of conceptual models can be

  2. Preliminary conceptual model for mineral evolution in Yucca Mountain

    International Nuclear Information System (INIS)

    Duffy, C.J.

    1993-12-01

    A model is presented for mineral alteration in Yucca Mountain, Nevada, that suggests that the mineral transformations observed there are primarily controlled by the activity of aqueous silica. The rate of these reactions is related to the rate of evolution of the metastable silica polymorphs opal-CT and cristobalite assuming that a SiO 2(aq) is fixed at the equilibrium solubility of the most soluble silica polymorph present. The rate equations accurately predict the present depths of disappearance of opal-CT and cristobalite. The rate equations have also been used to predict the extent of future mineral alteration that may result from emplacement of a high-level nuclear waste repository in Yucca Mountain. Relatively small changes in mineralogy are predicted, but these predictions are based on the assumption that emplacement of a repository would not increase the pH of water in Yucca Mountain nor increase its carbonate content. Such changes may significantly increase mineral alteration. Some of the reactions currently occurring in Yucca Mountain consume H + and CO 3 2- . Combining reaction rate models for these reactions with water chemistry data may make it possible to estimate water flux through the basal vitrophyre of the Topopah Spring Member and to help confirm the direction and rate of flow of groundwater in Yucca Mountain

  3. empirical modeling of oxygen modeling of oxygen uptake of flow

    African Journals Online (AJOL)

    eobe

    structure. Keywords: stepped chute, skimming flow, aeration l. 1. INTRODUCTION ..... [3] Toombes, L. and Chanson, H., “Air-water flow and gas transfer at aeration ... of numerical model of the flow behaviour through smooth and stepped.

  4. 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

  5. Geology and Conceptual Model of the Domuyo Geothermal Area, Patagonia, Argentina

    Science.gov (United States)

    Fragoso, A. S.; Ferrari, L.; Norini, G.

    2017-12-01

    Cerro Domuyo is the highest mountain in Patagonia and its western slope is characterized by thermal springs with boiling fluids as well as silicic domes and pyroclastic deposits that suggest the existence of a geothermal reservoir. Early studies proposed that the thermal springs were fault-controlled and the reservoir was located in a graben bounded by E-W normal faults. A recent geochemical study estimated a temperature of 220ºC for the fluid reservoir and a thermal energy release of 1.1 GW, one of the world largest advective heat flux from a continental volcanic center. We carried out a geologic survey and U-Pb and U-Th geochronologic study to elaborate an updated conceptual model for the Domuyo geothermal area. Our study indicates that the Domuyo Volcanic Complex (DVC) is a dome complex overlying an older, Middle Miocene to Pliocene volcanic sequence widely exposed to the southwest and to the north, which in turn covers: 1) the Jurassice-Early Creteacoeus Neuquen marine sedimentary succession, 2) silicic ignimbrites dated at 186.7 Ma and, 3) the Paleozoic metamorphic basement intruded by 288 Ma granite bodies. These pre-Cenozoic successions are involved in dominantly N-S trending folds and thrust faults later displaced by E-W striking normal faults with a right lateral component of motion that underlie the DVC. The volcanic cycle forming the DVC is distinctly bimodal with the emplacement of massive silicic domes but also less voluminous olivine basalts on its southern slope. The central dome underwent a major collapse that produced 0.35 km3 of ash and block flow and associated pyroclastic flows that filled the valley to the southwest up to 30 km from the source. This was followed by a voluminous effusive activity that formed silicic domes dated between 254-322 Ky, which is inferred to overlain a partially molten silicic magma chamber. Integrating the geologic model with magnetotelluric and gravity surveys we developed a conceptual model of the geothermal system

  6. Validation of the Continuum of Care Conceptual Model for Athletic Therapy

    Directory of Open Access Journals (Sweden)

    Mark R. Lafave

    2015-01-01

    Full Text Available Utilization of conceptual models in field-based emergency care currently borrows from existing standards of medical and paramedical professions. The purpose of this study was to develop and validate a comprehensive conceptual model that could account for injuries ranging from nonurgent to catastrophic events including events that do not follow traditional medical or prehospital care protocols. The conceptual model should represent the continuum of care from the time of initial injury spanning to an athlete’s return to participation in their sport. Finally, the conceptual model should accommodate both novices and experts in the AT profession. This paper chronicles the content validation steps of the Continuum of Care Conceptual Model for Athletic Therapy (CCCM-AT. The stages of model development were domain and item generation, content expert validation using a three-stage modified Ebel procedure, and pilot testing. Only the final stage of the modified Ebel procedure reached a priori 80% consensus on three domains of interest: (1 heading descriptors; (2 the order of the model; (3 the conceptual model as a whole. Future research is required to test the use of the CCCM-AT in order to understand its efficacy in teaching and practice within the AT discipline.

  7. Concurrent sketching model for the industrial product conceptual design

    Directory of Open Access Journals (Sweden)

    Juan Carlos Briede-Westermeyer

    2014-01-01

    Full Text Available El diseño conceptual, en el diseño de nuevos productos, es la e tapa temprana donde se definen aspectos claves del producto fin al. El enfoque sistémico aborda dicha fase a través de un modelo de desagregac ión teórica de los atributos del producto y su asociación a geo metrías que las representen, sirviendo de base para realizar la exploración de la propuesta conceptual. La investigación en torno al orige n de las diversas tipologías de boceto demuestra que se nombran en función de su propósito más que en su instrumentalización técnica. El modelo de abocetado concurrente planteado busca ser un modelo ampliado de l modelo sistémico para el diseño conceptual (Hernandis&Briede, 2009, que asocia el uso de las tipologías de boceto a las diversas et apas del modelo para facilitar y apoyar visualmente los proceso s cognitivos y la toma de decisiones en etapas teóricas iniciales, poco defini das y muy abstractas.

  8. The 8 Learning Events Model: a Pedagogic Conceptual Tool Supporting Diversification of Learning Methods

    NARCIS (Netherlands)

    Verpoorten, Dominique; Poumay, M; Leclercq, D

    2006-01-01

    Please, cite this publication as: Verpoorten, D., Poumay, M., & Leclercq, D. (2006). The 8 Learning Events Model: a Pedagogic Conceptual Tool Supporting Diversification of Learning Methods. Proceedings of International Workshop in Learning Networks for Lifelong Competence Development, TENCompetence

  9. [Self-Determination in Medical Rehabilitation - Development of a Conceptual Model for Further Theoretical Discussion].

    Science.gov (United States)

    Senin, Tatjana; Meyer, Thorsten

    2018-01-22

    Aim was to gather theoretical knowledge about self-determination and to develop a conceptual model for medical rehabilitation- which serves as a basis for discussion. We performed a literature research in electronic databases. Various theories and research results were adopted and transferred to the context of medical rehabilitation and into a conceptual model. The conceptual model of self-determination reflects on a continuum which forms of self-determination may be present in situations of medical rehabilitation treatments. The location on the continuum depends theoretically on the manifestation of certain internal and external factors that may influence each other. The model provides a first conceptualization of self-determination focusing on medical rehabilitation which should be further refined and tested empirically. © Georg Thieme Verlag KG Stuttgart · New York.

  10. Benefits of using a Social-Ecological Systems Approach to Conceptualize and Model Wetlands Restoration

    Science.gov (United States)

    Using a social-ecological systems (SES) perspective to examine wetland restoration helps decision-makers recognize interdependencies and relations between ecological and social components of coupled systems. Conceptual models are an invaluable tool to capture, visualize, and orga...

  11. Environmental Cleanup Best Management Practices: Effective Use of the Project Life Cycle Conceptual Site Model

    Science.gov (United States)

    This fact sheet is the first in a series of documents that address conceptual site models (CSMs). This fact sheet summarizes how environmental practitioners can use CSMs to achieve, communicate, and maintain stakeholder consensus.

  12. A conceptual model of channel choice : measuring online and offline shopping value perceptions

    NARCIS (Netherlands)

    Broekhuizen, Thijs L.J.; Jager, Wander

    2004-01-01

    This study tries to understand how consumers evaluate channels for their purchasing. Specifically, it develops a conceptual model that addresses consumer value perceptions of using the Internet versus the traditional (physical) channel. Previous research showed that perceptions of price, product

  13. Triad Issue Paper: Using Geophysical Tools to Develop the Conceptual Site Model

    Science.gov (United States)

    This technology bulletin explains how hazardous-waste site professionals can use geophysical tools to provide information about subsurface conditions to create a more representative conceptual site model (CSM).

  14. Supporting conceptual modelling of dynamic systems: A knowledge engineering perspective on qualitative reasoning

    NARCIS (Netherlands)

    Liem, J.

    2013-01-01

    Research has shown that even students educated in science at prestigious universities have misconceptions about the systems underlying climate change, sustainability and government spending. Interactive conceptual modelling and simulation tools, which are based on Artificial Intelligence techniques,

  15. A conceptual framework to model long-run qualitative change in the energy system

    OpenAIRE

    Ebersberger, Bernd

    2004-01-01

    A conceptual framework to model long-run qualitative change in the energy system / A. Pyka, B. Ebersberger, H. Hanusch. - In: Evolution and economic complexity / ed. J. Stanley Metcalfe ... - Cheltenham [u.a.] : Elgar, 2004. - S. 191-213

  16. MARKET ENTRY STRATEGIES TO EMERGING MARKETS: A CONCEPTUAL MODEL OF TURNKEY PROJECT DEVELOPMENT

    OpenAIRE

    Bistra Vassileva; Miroslav Nikolov

    2016-01-01

    The main purpose of the paper is to analyse the international market entry strategies in the light of globalisation processes and to propose a conceptual model of turnkey projects as market entry mode. The specific research objectives are as follows: 1. to develop an integrated framework of the turnkey marketing process as a conceptual model; 2. to analyse BRICS countries as potential host countries for turnkey projects implementation; 3. to assess potential implications of proposed concep...

  17. Large regional groundwater modeling - a sensitivity study of some selected conceptual descriptions and simplifications

    International Nuclear Information System (INIS)

    Ericsson, Lars O.; Holmen, Johan

    2010-12-01

    The primary aim of this report is: - To present a supplementary, in-depth evaluation of certain conceptual simplifications, descriptions and model uncertainties in conjunction with regional groundwater simulation, which in the first instance refer to model depth, topography, groundwater table level and boundary conditions. Implementation was based on geo-scientifically available data compilations from the Smaaland region but different conceptual assumptions have been analysed

  18. Prevention through Design Adoption Readiness Model (PtD ARM): An integrated conceptual model.

    Science.gov (United States)

    Weidman, Justin; Dickerson, Deborah E; Koebel, Charles T

    2015-01-01

    Prevention through Design (PtD), eliminating hazards at the design-stage of tools and systems, is the optimal method of mitigating occupational health and safety risks. A recent National Institute of Safety and Health initiative has established a goal to increase adoption of PtD innovation in industry. The construction industry has traditionally lagged behind other sectors in the adoption of innovation, in general; and of safety and health prevention innovation, in particular. Therefore, as a first step toward improving adoption trends in this sector, a conceptual model was developed to describe the parameters and causal relationships that influence and predict construction stakeholder "adoption readiness" for PtD technology innovation. This model was built upon three well-established theoretical frameworks: the Health Belief Model, the Diffusion of Innovation Model, and the Technology Acceptance Model. Earp and Ennett's model development methodology was employed to build a depiction of the key constructs and directionality and magnitude of relationships among them. Key constructs were identified from the literature associated with the three theoretical frameworks, with special emphasis given to studies related to construction or OHS technology adoption. A conceptual model is presented. Recommendations for future research are described and include confirmatory structural equation modeling of model parameters and relationships, additional descriptive investigation of barriers to adoption in some trade sectors, and design and evaluation of an intervention strategy.

  19. Adaptive Parameter Optimization of a Grid-based Conceptual Hydrological Model

    Science.gov (United States)

    Samaniego, L.; Kumar, R.; Attinger, S.

    2007-12-01

    Any spatially explicit hydrological model at the mesoscale is a conceptual approximation of the hydrological cycle and its dominant process occurring at this scale. Manual-expert calibration of this type of models may become quite tedious---if not impossible---taking into account the enormous amount of data required by these kind of models and the intrinsic uncertainty of both the data (input-output) and the model structure. Additionally, the model should be able to reproduce well several process which are accounted by a number of predefined objectives. As a consequence, some degree of automatic calibration would be required to find "good" solutions, each one constituting a trade-off among all calibration criteria. In other words, it is very likely that a number of parameter sets fulfil the optimization criteria and thus can be considered a model solution. In this study, we dealt with two research questions: 1) How to assess the adequate level of model complexity so that model overparameterization is avoided? And, 2) How to find a good solution with a relatively low computational burden? In the present study, a grid-based conceptual hydrological model denoted as HBV-UFZ based on some of the original HBV concepts was employed. This model was driven by 12~h precipitation, temperature, and PET grids which are acquired either from satellite products or from data of meteorological stations. In the latter case, the data was interpolated with external drift Kriging. The first research question was addressed in this study with the implementation of nonlinear transfer functions that regionalize most model parameters as a function of other spatially distributed observables such as land cover (time dependent) and other time independent basin characteristics such as soil type, slope, aspect, geological formations among others. The second question was addressed with an adaptive constrained optimization algorithm based on a parallel implementation of simulated annealing (SA

  20. Development of a hydrogeological conceptual wetland model in the data-scarce north-eastern region of Kilombero Valley, Tanzania

    Science.gov (United States)

    Burghof, Sonja; Gabiri, Geofrey; Stumpp, Christine; Chesnaux, Romain; Reichert, Barbara

    2018-02-01

    Understanding groundwater/surface-water interactions in wetlands is crucial because wetlands provide not only a high potential for agricultural production, but also sensitive and valuable ecosystems. This is especially true for the Kilombero floodplain wetland in Tanzania, which represents a data-scarce region in terms of hydrological and hydrogeological data. A comprehensive approach combining hydrogeological with tracer-based assessments was conducted, in order to develop a conceptual hydrogeological wetland model of the area around the city of Ifakara in the north-eastern region of Kilombero catchment. Within the study site, a heterogeneous porous aquifer, with a range of hydraulic conductivities, is underlain by a fractured-rock aquifer. Groundwater chemistry is mainly influenced by silicate weathering and depends on groundwater residence times related to the hydraulic conductivities of the porous aquifer. Groundwater flows from the hillside to the river during most of the year. While floodwater close to the river is mainly derived from overbank flow of the river, floodwater at a greater distance from the river mainly originates from precipitation and groundwater discharge. Evaporation effects in floodwater increase with increasing distance from the river. In general, the contribution of flood and stream water to groundwater recharge is negligible. In terms of an intensification of agricultural activities in the wetland, several conclusions can be drawn from the conceptual model. Results of this study are valuable as a base for further research related to groundwater/surface-water interactions and the conceptual model can be used in the future to set up numerical flow and transport models.

  1. Hydrodynamics of burst swimming fish larvae; a conceptual model approach

    NARCIS (Netherlands)

    Verhagen, J.H.G.

    2004-01-01

    Burst swimming of fish larvae is analysed from a hydrodynamic point of view. A picture of the expected flow pattern is presented based on information in literature on unsteady-flow patterns around obstacles in the intermediate Reynolds number region. It is shown that the acceleration stage of burst

  2. Transient Inverse Calibration of Site-Wide Groundwater Model to Hanford Operational Impacts from 1943 to 1996-Alternative Conceptual Model Considering Interaction with Uppermost Basalt Confined Aquifer; FINAL

    International Nuclear Information System (INIS)

    Vermeul, Vince R; Cole, Charles R; Bergeron, Marcel P; Thorne, Paul D; Wurstner, Signe K

    2001-01-01

    The baseline three-dimensional transient inverse model for the estimation of site-wide scale flow parameters, including their uncertainties, using data on the transient behavior of the unconfined aquifer system over the entire historical period of Hanford operations, has been modified to account for the effects of basalt intercommunication between the Hanford unconfined aquifer and the underlying upper basalt confined aquifer. Both the baseline and alternative conceptual models (ACM-1) considered only the groundwater flow component and corresponding observational data in the 3-Dl transient inverse calibration efforts. Subsequent efforts will examine both groundwater flow and transport. Comparisons of goodness of fit measures and parameter estimation results for the ACM-1 transient inverse calibrated model with those from previous site-wide groundwater modeling efforts illustrate that the new 3-D transient inverse model approach will strengthen the technical defensibility of the final model(s) and provide the ability to incorporate uncertainty in predictions related to both conceptual model and parameter uncertainty

  3. Site-Scale Saturated Zone Flow Model

    International Nuclear Information System (INIS)

    G. Zyvoloski

    2003-01-01

    The purpose of this model report is to document the components of the site-scale saturated-zone flow model at Yucca Mountain, Nevada, in accordance with administrative procedure (AP)-SIII.lOQ, ''Models''. This report provides validation and confidence in the flow model that was developed for site recommendation (SR) and will be used to provide flow fields in support of the Total Systems Performance Assessment (TSPA) for the License Application. The output from this report provides the flow model used in the ''Site-Scale Saturated Zone Transport'', MDL-NBS-HS-000010 Rev 01 (BSC 2003 [162419]). The Site-Scale Saturated Zone Transport model then provides output to the SZ Transport Abstraction Model (BSC 2003 [164870]). In particular, the output from the SZ site-scale flow model is used to simulate the groundwater flow pathways and radionuclide transport to the accessible environment for use in the TSPA calculations. Since the development and calibration of the saturated-zone flow model, more data have been gathered for use in model validation and confidence building, including new water-level data from Nye County wells, single- and multiple-well hydraulic testing data, and new hydrochemistry data. In addition, a new hydrogeologic framework model (HFM), which incorporates Nye County wells lithology, also provides geologic data for corroboration and confidence in the flow model. The intended use of this work is to provide a flow model that generates flow fields to simulate radionuclide transport in saturated porous rock and alluvium under natural or forced gradient flow conditions. The flow model simulations are completed using the three-dimensional (3-D), finite-element, flow, heat, and transport computer code, FEHM Version (V) 2.20 (software tracking number (STN): 10086-2.20-00; LANL 2003 [161725]). Concurrently, process-level transport model and methodology for calculating radionuclide transport in the saturated zone at Yucca Mountain using FEHM V 2.20 are being

  4. A scalable approach to modeling groundwater flow on massively parallel computers

    International Nuclear Information System (INIS)

    Ashby, S.F.; Falgout, R.D.; Tompson, A.F.B.

    1995-12-01

    We describe a fully scalable approach to the simulation of groundwater flow on a hierarchy of computing platforms, ranging from workstations to massively parallel computers. Specifically, we advocate the use of scalable conceptual models in which the subsurface model is defined independently of the computational grid on which the simulation takes place. We also describe a scalable multigrid algorithm for computing the groundwater flow velocities. We axe thus able to leverage both the engineer's time spent developing the conceptual model and the computing resources used in the numerical simulation. We have successfully employed this approach at the LLNL site, where we have run simulations ranging in size from just a few thousand spatial zones (on workstations) to more than eight million spatial zones (on the CRAY T3D)-all using the same conceptual model

  5. Studying shocks in model astrophysical flows

    International Nuclear Information System (INIS)

    Chakrabarti, S.K.

    1989-01-01

    We briefly discuss some properties of the shocks in the existing models for quasi two-dimensional astrophysical flows. All of these models which allow the study of shock analytically have some unphysical characteristics due to inherent assumptions made. We propose a hybrid model for a thin flow which has fewer unpleasant features and is suitable for the study of shocks. (author). 5 refs

  6. Tolerance of uncertainty: Conceptual analysis, integrative model, and implications for healthcare.

    Science.gov (United States)

    Hillen, Marij A; Gutheil, Caitlin M; Strout, Tania D; Smets, Ellen M A; Han, Paul K J

    2017-05-01

    Uncertainty tolerance (UT) is an important, well-studied phenomenon in health care and many other important domains of life, yet its conceptualization and measurement by researchers in various disciplines have varied substantially and its essential nature remains unclear. The objectives of this study were to: 1) analyze the meaning and logical coherence of UT as conceptualized by developers of UT measures, and 2) develop an integrative conceptual model to guide future empirical research regarding the nature, causes, and effects of UT. A narrative review and conceptual analysis of 18 existing measures of Uncertainty and Ambiguity Tolerance was conducted, focusing on how measure developers in various fields have defined both the "uncertainty" and "tolerance" components of UT-both explicitly through their writings and implicitly through the items constituting their measures. Both explicit and implicit conceptual definitions of uncertainty and tolerance vary substantially and are often poorly and inconsistently specified. A logically coherent, unified understanding or theoretical model of UT is lacking. To address these gaps, we propose a new integrative definition and multidimensional conceptual model that construes UT as the set of negative and positive psychological responses-cognitive, emotional, and behavioral-provoked by the conscious awareness of ignorance about particular aspects of the world. This model synthesizes insights from various disciplines and provides an organizing framework for future research. We discuss how this model can facilitate further empirical and theoretical research to better measure and understand the nature, determinants, and outcomes of UT in health care and other domains of life. Uncertainty tolerance is an important and complex phenomenon requiring more precise and consistent definition. An integrative definition and conceptual model, intended as a tentative and flexible point of departure for future research, adds needed breadth

  7. Organizational intellectual capital and the role of the nurse manager: A proposed conceptual model.

    Science.gov (United States)

    Gilbert, Jason H; Von Ah, Diane; Broome, Marion E

    Nurse managers must leverage both the human capital and social capital of the teams they lead in order to produce quality outcomes. Little is known about the relationship between human capital and social capital and how these concepts may work together to produce organizational outcomes through leadership of nurses. The purpose of this article was to explore the concepts of human capital and social capital as they relate to nursing leadership in health care organizations. Specific aims included (a) to synthesize the literature related to human capital and social capital in leadership, (b) to refine the conceptual definitions of human capital and social capital with associated conceptual antecedents and consequences, and (c) to propose a synthesized conceptual model guiding further empirical research of social capital and human capital in nursing leadership. A systematic integrative review of leadership literature using criteria informed by Whittemore and Knafl (2005) was completed. CINAHL Plus with Full Text, Academic Search Premier, Business Source Premier, Health Business FullTEXT, MEDLINE, and PsychINFO databases were searched for the years 1995 to 2016 using terms "human capital," "social capital," and "management." Analysis of conceptual definitions, theoretical and conceptual models, antecedents and consequences, propositions or hypotheses, and empirical support for 37 articles fitting review criteria resulted in the synthesis of the proposed Gilbert Conceptual Model of Organizational Intellectual Capital. The Gilbert Conceptual Model of Organizational Intellectual Capital advances the propositions of human capital theory and social capital theory and is the first model to conceptualize the direct and moderating effects that nurse leaders have on the human capital and social capital of the teams they lead. This model provides a framework for further empirical study and may have implications for practice, organizational policy, and education related to nursing

  8. Measuring and Modeling Flow in Welded Fractured Tuffs

    International Nuclear Information System (INIS)

    R. Salve; C. Doughty; J.S. Wang

    2001-01-01

    We have carried out a series of in situ liquid-release experiments in conjunction with a numerical modeling study to examine the effect of the rock matrix on liquid flow and transport occurring primarily through the fracture network. Field experiments were conducted in the highly fractured Topopah Spring welded tuff at a site accessed from the Exploratory Studies Facility (ESFS), an underground laboratory in the unsaturated zone at Yucca Mountain, Nevada. During the experiment, wetting-front movement, flow-field evolution, and drainage of fracture flow paths were evaluated. Modeling was used to aid in experimental design, predict experimental results, and study the physical processes accompanying liquid flow through unsaturated fractured welded tuff. Field experiments and modeling suggest that it may not be sufficient to conceptualize the fractured tuff as consisting of a single network of high-permeability fractures embedded in a low-permeability matrix. The need to include a secondary fracture network is demonstrated by comparison to the liquid flow observed in the field

  9. A Conceptual Model for Analysing Management Development in the UK Hospitality Industry

    Science.gov (United States)

    Watson, Sandra

    2007-01-01

    This paper presents a conceptual, contingent model of management development. It explains the nature of the UK hospitality industry and its potential influence on MD practices, prior to exploring dimensions and relationships in the model. The embryonic model is presented as a model that can enhance our understanding of the complexities of the…

  10. Two-phase flow model with nonequilibrium and critical flow

    International Nuclear Information System (INIS)

    Sureau, H.; Houdayer, G.

    1976-01-01

    The model proposed includes the three conservation equations (mass, momentum, energy) applied to the two phase flows and a fourth partial derivative equation which takes into account the nonequilibriums and describes the mass transfer process. With this model, the two phase critical flow tests performed on the Moby-Dick loop (CENG) with several geometries, are interpreted by a unique law. Extrapolations to industrial dimension problems show that geometry and size effects are different from those obtained with earlier models (Zaloudek, Moody, Fauske) [fr

  11. CADDIS Volume 2. Sources, Stressors and Responses: Flow Alteration

    Science.gov (United States)

    Introduction to the flow alteration module, when to list flow alteration as a candidate cause, ways to measure flow alteration, simple and detailed conceptual model diagrams for flow alteration, flow alteration module references and literature reviews.

  12. Conceptual model for marketing solar based technology to developing countries

    International Nuclear Information System (INIS)

    Peter, Raj; Ramaseshan, B.; Nayar, C.V.

    2002-01-01

    Developing countries are faced with large shortfalls of electric-power generation, shortages of usable indigenous fuels, and transportation bottlenecks for those fuels. The loss of revenue that is forced upon the industry due to power cuts and frequent interruptions of power supply is substantial. Renewable sources of energy have an important role to play in providing much needed power in the context of growing global concern about sustainable energy supplies and protecting the environment from the adverse effects of fossil fuel utilization. The purpose of the study is to identify the factors that influence the adoption of solar-based technology. An examination of the literature in the area of diffusion of technology has led to the identification of different variables. The possible relationships that may exist between these variables is depicted in the conceptual framework. This paper attempts to clarify the relationships between the variables that have been identified and the decision to adopt. (Author)

  13. Second status report on regional and local ground-water flow modeling for Richton and Cypress Creek Domes, Mississippi

    International Nuclear Information System (INIS)

    1986-08-01

    Regional and local ground-water flow within the principal geohydrologic units in the Mississippi salt-dome basin is evaluated by developing conceptual models of the flow regime at a regional and a local scale and testing these models using a three-dimensional, finite-difference flow code. Semiquantitative sensitivity analyses (a limited parametric study) are conducted to define the system response to changes in the conceptual models. The conceptual models are described in terms of their areal and vertical discretizations, aquifer properties, fluid properties, and hydrologic boundary conditions. The simulated ground-water flow fields are described with potentiometric surfaces, areas of upward and downward flow across aquitards, tables summarizing the real and vertical volumetric flows through the principal units, and Darcy velocities with specified finite-difference blocks. Ground-water travel paths and times from both Richton Dome and Cypress Creek Dome are provided. The regional scale simulation results are discussed with regard to measured field data. The reported work is the second state of an ongoing evaluation of Richton and Cypress Creek Domes as potential repositories for high-level radioactive wastes. The results and conclusions should thus be considered preliminary and subject to modification with the collection of additional data. However, the report does provide a useful basis for describing the sensitivity of the present conceptualization of ground-water flow to parameterization and, to a lesser extent, the uncertainties in the present conceptualization. 19 refs., 33 figs., 25 tabs

  14. A beginner's guide to writing the nursing conceptual model-based theoretical rationale.

    Science.gov (United States)

    Gigliotti, Eileen; Manister, Nancy N

    2012-10-01

    Writing the theoretical rationale for a study can be a daunting prospect for novice researchers. Nursing's conceptual models provide excellent frameworks for placement of study variables, but moving from the very abstract concepts of the nursing model to the less abstract concepts of the study variables is difficult. Similar to the five-paragraph essay used by writing teachers to assist beginning writers to construct a logical thesis, the authors of this column present guidelines that beginners can follow to construct their theoretical rationale. This guide can be used with any nursing conceptual model but Neuman's model was chosen here as the exemplar.

  15. A Conceptual Model to Identify Intent to Use Chemical-Biological Weapons

    Directory of Open Access Journals (Sweden)

    Mary Zalesny

    2017-10-01

    Full Text Available This paper describes a conceptual model to identify and interrelate indicators of intent of non-state actors to use chemical or biological weapons. The model expands on earlier efforts to understand intent to use weapons of mass destruction by building upon well-researched theories of intent and behavior and focusing on a sub-set of weapons of mass destruction (WMD to account for the distinct challenges of employing different types of WMD in violent acts. The conceptual model is presented as a first, critical step in developing a computational model for assessing the potential for groups to use chemical or biological weapons.

  16. Volcanic aquifers of Hawai‘i—Hydrogeology, water budgets, and conceptual models

    Science.gov (United States)

    Izuka, Scot K.; Engott, John A.; Rotzoll, Kolja; Bassiouni, Maoya; Johnson, Adam G.; Miller, Lisa D.; Mair, Alan

    2016-06-13

    Hawai‘i’s aquifers have limited capacity to store fresh groundwater because each island is small and surrounded by saltwater. Saltwater also underlies much of the fresh groundwater. Fresh groundwater resources are, therefore, particularly vulnerable to human activity, short-term climate cycles, and long-term climate change. Availability of fresh groundwater for human use is constrained by the degree to which the impacts of withdrawal—such as lowering of the water table, saltwater intrusion, and reduction in the natural discharge to springs, streams, wetlands, and submarine seeps—are deemed acceptable. This report describes the hydrogeologic framework, groundwater budgets (inflows and outflows), conceptual models of groundwater occurrence and movement, and the factors limiting groundwater availability for the largest and most populated of the Hawaiian Islands—Kaua‘i, O‘ahu, Maui, and Hawai‘i Island.The bulk of each of Hawai‘i’s islands is built of many thin lava flows erupted from shield volcanoes; the great piles of lava flows form highly permeable aquifers. In some areas, low-permeability dikes cutting across the lava flows, or low-permeability ash and soil horizons interlayered with the lava flows, can substantially alter groundwater flow. On some islands, sedimentary rocks form thick semiconfining coastal-plain deposits, locally known as caprock, that impede natural groundwater discharge to the ocean. In some regions, thick lava flows that ponded in preexisting depressions form aquifers that are much less permeable than aquifers formed by thin lava flows.Fresh groundwater inflow to Hawai‘i’s aquifers comes from recharge. For predevelopment conditions (1870), estimates of groundwater recharge from this study are 871, 675, 1,279, and 5,291 million gallons per day (Mgal/d) for Kaua‘i, O‘ahu, Maui, and Hawai‘i Island, respectively. Estimates of recharge for recent conditions (2010 land cover and 1978–2007 rainfall for Kaua‘i, O

  17. Aeroacoustic modelling of low-speed flows

    Energy Technology Data Exchange (ETDEWEB)

    Wen Zhong Shen; Noerkaer Soerensen, Jens

    1998-08-01

    A new numerical algorithm for acoustic noise generation is developed. The approach involves two steps comprising an incompressible flow part and inviscid acoustic part. The acoustic part can be started at any time of the incompressible computation. The formulation can be applied both for isentropic flows and non-isentropic flows. The model is validated for the cases of an isentropic pulsating sphere and non-isentropic flows past a circular cylinder and a NACA 0015 airfoil. The computations show that the generated acoustic frequencies have the form 1/m of the basic frequency of incompressible flow. (au) 15 refs.

  18. Combining Different Conceptual Change Methods within 5E Model: A Sample Teaching Design of "Cell" Concept and its Organelles

    Science.gov (United States)

    Urey, Mustafa; Calik, Muammer

    2008-01-01

    Since students' misconceptions are not completely remedied by means of only one conceptual change method, the authors assume that using different conceptual methods embedded within the 5E model will not only be more effective in enhancing students' conceptual understanding, but also may eliminate all students' misconceptions. The aim of this study…

  19. A turbulent two-phase flow model for nebula flows

    International Nuclear Information System (INIS)

    Champney, J.M.; Cuzzi, J.N.

    1990-01-01

    A new and very efficient turbulent two-phase flow numericaly model is described to analyze the environment of a protoplanetary nebula at a stage prior to the formation of planets. Focus is on settling processes of dust particles in flattened gaseous nebulae. The model employs a perturbation technique to improve the accuracy of the numerical simulations of such flows where small variations of physical quantities occur over large distance ranges. The particles are allowed to be diffused by gas turbulence in addition to settling under gravity. Their diffusion coefficients is related to the gas turbulent viscosity by the non-dimensional Schmidt number. The gas turbulent viscosity is determined by the means of the eddy viscosity hypothesis that assumes the Reynolds stress tensor proportional to the mean strain rate tensor. Zero- and two-equation turbulence models are employed. Modeling assumptions are detailed and discussed. The numerical model is shown to reproduce an existing analytical solution for the settling process of particles in an inviscid nebula. Results of nebula flows are presented taking into account turbulence effects of nebula flows. Diffusion processes are found to control the settling of particles. 24 refs

  20. A Review on Macroscopic Pedestrian Flow Modelling

    Directory of Open Access Journals (Sweden)

    Anna Kormanová

    2013-12-01

    Full Text Available This paper reviews several various approaches to macroscopic pedestrian modelling. It describes hydrodynamic models based on similarity of pedestrian flow with fluids and gases; first-order flow models that use fundamental diagrams and conservation equation; and a model similar to LWR vehicular traffic model, which allows non-classical shocks. At the end of the paper there is stated a comparison of described models, intended to find appropriate macroscopic model to eventually be a part of a hybrid model. The future work of the author is outlined.

  1. A proposed strategy for the validation of ground-water flow and solute transport models

    International Nuclear Information System (INIS)

    Davis, P.A.; Goodrich, M.T.

    1991-01-01

    Ground-water flow and transport models can be thought of as a combination of conceptual and mathematical models and the data that characterize a given system. The judgment of the validity or invalidity of a model depends both on the adequacy of the data and the model structure (i.e., the conceptual and mathematical model). This report proposes a validation strategy for testing both components independently. The strategy is based on the philosophy that a model cannot be proven valid, only invalid or not invalid. In addition, the authors believe that a model should not be judged in absence of its intended purpose. Hence, a flow and transport model may be invalid for one purpose but not invalid for another. 9 refs

  2. Probabilistically modeling lava flows with MOLASSES

    Science.gov (United States)

    Richardson, J. A.; Connor, L.; Connor, C.; Gallant, E.

    2017-12-01

    Modeling lava flows through Cellular Automata methods enables a computationally inexpensive means to quickly forecast lava flow paths and ultimate areal extents. We have developed a lava flow simulator, MOLASSES, that forecasts lava flow inundation over an elevation model from a point source eruption. This modular code can be implemented in a deterministic fashion with given user inputs that will produce a single lava flow simulation. MOLASSES can also be implemented in a probabilistic fashion where given user inputs define parameter distributions that are randomly sampled to create many lava flow simulations. This probabilistic approach enables uncertainty in input data to be expressed in the model results and MOLASSES outputs a probability map of inundation instead of a determined lava flow extent. Since the code is comparatively fast, we use it probabilistically to investigate where potential vents are located that may impact specific sites and areas, as well as the unconditional probability of lava flow inundation of sites or areas from any vent. We have validated the MOLASSES code to community-defined benchmark tests and to the real world lava flows at Tolbachik (2012-2013) and Pico do Fogo (2014-2015). To determine the efficacy of the MOLASSES simulator at accurately and precisely mimicking the inundation area of real flows, we report goodness of fit using both model sensitivity and the Positive Predictive Value, the latter of which is a Bayesian posterior statistic. Model sensitivity is often used in evaluating lava flow simulators, as it describes how much of the lava flow was successfully modeled by the simulation. We argue that the positive predictive value is equally important in determining how good a simulator is, as it describes the percentage of the simulation space that was actually inundated by lava.

  3. Navigating Tensions Between Conceptual and Metaconceptual Goals in the Use of Models

    Science.gov (United States)

    Delgado, Cesar

    2015-04-01

    Science education involves learning about phenomena at three levels: concrete (facts and generalizations), conceptual (concepts and theories), and metaconceptual (epistemology) (Snir et al. in J Sci Educ Technol 2(2):373-388, 1993). Models are key components in science, can help build conceptual understanding, and may also build metaconceptual understanding. Technology can transform teaching and learning by turning models into interactive simulations that learners can investigate. This paper identifies four characteristics of models and simulations that support conceptual learning but misconstrue models and science at a metaconceptual level. Ahistorical models combine the characteristics of several historical models; they conveniently compile ideas but misrepresent the history of science (Gilbert in Int J Sci Math Educ 2(2):115-130, 2004). Teleological models explain behavior in terms of a final cause; they can lead to useful heuristics but imply purpose in processes driven by chance and probability (Talanquer in Int J Sci Educ 29(7):853-870, 2007). Epistemological overreach occurs when models or simulations imply greater certainty and knowledge about phenomena than warranted; conceptualizing nature as being well known (e.g., having a mathematical structure) poses the danger of conflating model and reality or data and theory. Finally, models are inevitably ontologically impoverished. Real-world deviations and many variables are left out of models, as models' role is to simplify. Models and simulations also lose much of the sensory data present in phenomena. Teachers, designers, and professional development designers and facilitators must thus navigate the tension between conceptual and metaconceptual learning when using models and simulations. For each characteristic, examples are provided, along with recommendations for instruction and design. Prompts for explicit reflective activities around models are provided for each characteristic

  4. Conceptual model of sediment processes in the upper Yuba River watershed, Sierra Nevada, CA

    Science.gov (United States)

    Curtis, J.A.; Flint, L.E.; Alpers, Charles N.; Yarnell, S.M.

    2005-01-01

    This study examines the development of a conceptual model of sediment processes in the upper Yuba River watershed; and we hypothesize how components of the conceptual model may be spatially distributed using a geographical information system (GIS). The conceptual model illustrates key processes controlling sediment dynamics in the upper Yuba River watershed and was tested and revised using field measurements, aerial photography, and low elevation videography. Field reconnaissance included mass wasting and channel storage inventories, assessment of annual channel change in upland tributaries, and evaluation of the relative importance of sediment sources and transport processes. Hillslope erosion rates throughout the study area are relatively low when compared to more rapidly eroding landscapes such as the Pacific Northwest and notable hillslope sediment sources include highly erodible andesitic mudflows, serpentinized ultramafics, and unvegetated hydraulic mine pits. Mass wasting dominates surface erosion on the hillslopes; however, erosion of stored channel sediment is the primary contributor to annual sediment yield. We used GIS to spatially distribute the components of the conceptual model and created hillslope erosion potential and channel storage models. The GIS models exemplify the conceptual model in that landscapes with low potential evapotranspiration, sparse vegetation, steep slopes, erodible geology and soils, and high road densities display the greatest hillslope erosion potential and channel storage increases with increasing stream order. In-channel storage in upland tributaries impacted by hydraulic mining is an exception. Reworking of stored hydraulic mining sediment in low-order tributaries continues to elevate upper Yuba River sediment yields. Finally, we propose that spatially distributing the components of a conceptual model in a GIS framework provides a guide for developing more detailed sediment budgets or numerical models making it an

  5. Mass discharge estimation from contaminated sites: Multi-model solutions for assessment of conceptual uncertainty

    Science.gov (United States)

    Thomsen, N. I.; Troldborg, M.; McKnight, U. S.; Binning, P. J.; Bjerg, P. L.

    2012-04-01

    Mass discharge estimates are increasingly being used in the management of contaminated sites. Such estimates have proven useful for supporting decisions related to the prioritization of contaminated sites in a groundwater catchment. Potential management options can be categorised as follows: (1) leave as is, (2) clean up, or (3) further investigation needed. However, mass discharge estimates are often very uncertain, which may hamper the management decisions. If option 1 is incorrectly chosen soil and water quality will decrease, threatening or destroying drinking water resources. The risk of choosing option 2 is to spend money on remediating a site that does not pose a problem. Choosing option 3 will often be safest, but may not be the optimal economic solution. Quantification of the uncertainty in mass discharge estimates can therefore greatly improve the foundation for selecting the appropriate management option. The uncertainty of mass discharge estimates depends greatly on the extent of the site characterization. A good approach for uncertainty estimation will be flexible with respect to the investigation level, and account for both parameter and conceptual model uncertainty. We propose a method for quantifying the uncertainty of dynamic mass discharge estimates from contaminant point sources on the local scale. The method considers both parameter and conceptual uncertainty through a multi-model approach. The multi-model approach evaluates multiple conceptual models for the same site. The different conceptual models consider different source characterizations and hydrogeological descriptions. The idea is to include a set of essentially different conceptual models where each model is believed to be realistic representation of the given site, based on the current level of information. Parameter uncertainty is quantified using Monte Carlo simulations. For each conceptual model we calculate a transient mass discharge estimate with uncertainty bounds resulting from

  6. Modeling and simulation of reactive flows

    CERN Document Server

    Bortoli, De AL; Pereira, Felipe

    2015-01-01

    Modelling and Simulation of Reactive Flows presents information on modeling and how to numerically solve reactive flows. The book offers a distinctive approach that combines diffusion flames and geochemical flow problems, providing users with a comprehensive resource that bridges the gap for scientists, engineers, and the industry. Specifically, the book looks at the basic concepts related to reaction rates, chemical kinetics, and the development of reduced kinetic mechanisms. It considers the most common methods used in practical situations, along with equations for reactive flows, and va

  7. Hydrogeological conceptual model for Guarani Aquifer System: A tool for management; Modelo hidrogeologico conceptual del Sistema Acuifero Guarani (SAG): una herramienta para la gestion

    Energy Technology Data Exchange (ETDEWEB)

    Gastmans, D.; Veroslavsky, G.; Kiang Cahng, H.; Caetano-Chang, M. R.; Nogueira Pressinotti, M. M.

    2012-11-01

    The Guarani aquifer system (GAS) extends beneath the territories of Argentina, Brazil, Paraguay and Uruguay and thus represents a typical example of a transboundary aquifer. The GAS is an important source of drinking water for the population living within its area. Because of differences in the legal norms concerning water resources in these four countries, an urgently required legal framework for the shared management of the groundwater is currently being drawn up. Within this context, the conceptual regional hydrogeological model should be used as an important tool to delineate shared actions, particularly in regions where the groundwater flow is transboundary. The GAS is considered to be a continuous aquifer made up of Mesozoic continental clastic sedimentary rocks that occur in the Parana and Chacoparanense sedimentary basins, and is bounded at its base by a Permo-Eotriassic regional unconformity and at the top by lower-Cretaceous basaltic lava. The groundwater flow shows a regional trend from N to S along the main axis of these basins. With regard to the major tectonic structures of these sedimentary basins, various main hydrodynamic domains can be distinguished, such as the Ponta Grossa arch and the Asuncion-Rio Grande dorsal. Regional recharge areas are primarily located in the eastern and northern outcrop areas, whilst the western end of the GAS, the Mato Grosso do Sul, contains zones of local recharge and regional discharge. Transboundary flow is observed in areas confined to the national borders of the four countries. Nevertheless, due to the groundwater residence times in the GAS special management actions are called for to prevent over-exploitation, particularly in the confined zones of the aquifer. (Author)

  8. Development of Numerical Grids for UZ Flow and Transport Modeling

    International Nuclear Information System (INIS)

    Hinds, J.

    2001-01-01

    This Analysis/Model Report (AMR) describes the methods used to develop numerical grids of the unsaturated hydrogeologic system beneath Yucca Mountain. Numerical grid generation is an integral part of the development of a complex, three-dimensional (3-D) model, such as the Unsaturated-Zone Flow and Transport Model (UZ Model) of Yucca Mountain. The resulting numerical grids, developed using current geologic, hydrogeologic, and mineralogic data, provide the necessary framework to: (1) develop calibrated hydrogeologic property sets and flow fields, (2) test conceptual hypotheses of flow and transport, and (3) predict flow and transport behavior under a variety of climatic and thermal loading conditions. Revision 00 of the work described herein follows the planning and work direction outlined in the ''Development of Numerical Grids for UZ Flow and Transport Modeling'' (CRWMS M and O 1999c). The technical scope, content, and management of ICN 01 of this AMR is currently controlled by the planning document, ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' (BSC 2001a). The scope for the TBV resolution actions in this ICN is described in the ''Technical Work Plan for: Integrated Management of Technical Product Input Department'' (BSC 2001 b, Addendum B, Section 4.1). The steps involved in numerical grid development include: (1) defining the location of important calibration features, (2) determining model grid layers and fault geometry based on the Geologic Framework Model (GFM), the Integrated Site Model (ISM), and definition of hydrogeologic units (HGUs), (3) analyzing and extracting GFM and ISM data pertaining to layer contacts and property distributions, (4) discretizing and refining the two-dimensional (2-D), plan-view numerical grid, (5) generating the 3-D grid with finer resolution at the repository horizon and within the Calico Hills nonwelded (CHn) hydrogeologic unit, and (6) formulating the dual-permeability mesh. The

  9. Hydrogeologic Framework Model for the Saturated Zone Site Scale flow and Transport Model

    Energy Technology Data Exchange (ETDEWEB)

    T. Miller

    2004-11-15

    The purpose of this report is to document the 19-unit, hydrogeologic framework model (19-layer version, output of this report) (HFM-19) with regard to input data, modeling methods, assumptions, uncertainties, limitations, and validation of the model results in accordance with AP-SIII.10Q, Models. The HFM-19 is developed as a conceptual model of the geometric extent of the hydrogeologic units at Yucca Mountain and is intended specifically for use in the development of the ''Saturated Zone Site-Scale Flow Model'' (BSC 2004 [DIRS 170037]). Primary inputs to this model report include the GFM 3.1 (DTN: MO9901MWDGFM31.000 [DIRS 103769]), borehole lithologic logs, geologic maps, geologic cross sections, water level data, topographic information, and geophysical data as discussed in Section 4.1. Figure 1-1 shows the information flow among all of the saturated zone (SZ) reports and the relationship of this conceptual model in that flow. The HFM-19 is a three-dimensional (3-D) representation of the hydrogeologic units surrounding the location of the Yucca Mountain geologic repository for spent nuclear fuel and high-level radioactive waste. The HFM-19 represents the hydrogeologic setting for the Yucca Mountain area that covers about 1,350 km2 and includes a saturated thickness of about 2.75 km. The boundaries of the conceptual model were primarily chosen to be coincident with grid cells in the Death Valley regional groundwater flow model (DTN: GS960808312144.003 [DIRS 105121]) such that the base of the site-scale SZ flow model is consistent with the base of the regional model (2,750 meters below a smoothed version of the potentiometric surface), encompasses the exploratory boreholes, and provides a framework over the area of interest for groundwater flow and radionuclide transport modeling. In depth, the model domain extends from land surface to the base of the regional groundwater flow model (D'Agnese et al. 1997 [DIRS 100131], p 2). For the site

  10. Hydrogeologic Framework Model for the Saturated Zone Site Scale flow and Transport Model

    International Nuclear Information System (INIS)

    Miller, T.

    2004-01-01

    The purpose of this report is to document the 19-unit, hydrogeologic framework model (19-layer version, output of this report) (HFM-19) with regard to input data, modeling methods, assumptions, uncertainties, limitations, and validation of the model results in accordance with AP-SIII.10Q, Models. The HFM-19 is developed as a conceptual model of the geometric extent of the hydrogeologic units at Yucca Mountain and is intended specifically for use in the development of the ''Saturated Zone Site-Scale Flow Model'' (BSC 2004 [DIRS 170037]). Primary inputs to this model report include the GFM 3.1 (DTN: MO9901MWDGFM31.000 [DIRS 103769]), borehole lithologic logs, geologic maps, geologic cross sections, water level data, topographic information, and geophysical data as discussed in Section 4.1. Figure 1-1 shows the information flow among all of the saturated zone (SZ) reports and the relationship of this conceptual model in that flow. The HFM-19 is a three-dimensional (3-D) representation of the hydrogeologic units surrounding the location of the Yucca Mountain geologic repository for spent nuclear fuel and high-level radioactive waste. The HFM-19 represents the hydrogeologic setting for the Yucca Mountain area that covers about 1,350 km2 and includes a saturated thickness of about 2.75 km. The boundaries of the conceptual model were primarily chosen to be coincident with grid cells in the Death Valley regional groundwater flow model (DTN: GS960808312144.003 [DIRS 105121]) such that the base of the site-scale SZ flow model is consistent with the base of the regional model (2,750 meters below a smoothed version of the potentiometric surface), encompasses the exploratory boreholes, and provides a framework over the area of interest for groundwater flow and radionuclide transport modeling. In depth, the model domain extends from land surface to the base of the regional groundwater flow model (D'Agnese et al. 1997 [DIRS 100131], p 2). For the site-scale SZ flow model, the HFM

  11. Conceptual geoinformation model of natural hazards risk assessment

    Science.gov (United States)

    Kulygin, Valerii

    2016-04-01

    Natural hazards are the major threat to safe interactions between nature and society. The assessment of the natural hazards impacts and their consequences is important in spatial planning and resource management. Today there is a challenge to advance our understanding of how socio-economical and climate changes will affect the frequency and magnitude of hydro-meteorological hazards and associated risks. However, the impacts from different types of natural hazards on various marine and coastal economic activities are not of the same type. In this study, the conceptual geomodel of risk assessment is presented to highlight the differentiation by the type of economic activities in extreme events risk assessment. The marine and coastal ecosystems are considered as the objects of management, on the one hand, and as the place of natural hazards' origin, on the other hand. One of the key elements in describing of such systems is the spatial characterization of their components. Assessment of ecosystem state is based on ecosystem indicators (indexes). They are used to identify the changes in time. The scenario approach is utilized to account for the spatio-temporal dynamics and uncertainty factors. Two types of scenarios are considered: scenarios of using ecosystem services by economic activities and scenarios of extreme events and related hazards. The reported study was funded by RFBR, according to the research project No. 16-35-60043 mol_a_dk.

  12. Conceptual Model of Offshore Wind Environmental Risk Evaluation System

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Richard M.; Copping, Andrea E.; Van Cleve, Frances B.; Unwin, Stephen D.; Hamilton, Erin L.

    2010-06-01

    In this report we describe the development of the Environmental Risk Evaluation System (ERES), a risk-informed analytical process for estimating the environmental risks associated with the construction and operation of offshore wind energy generation projects. The development of ERES for offshore wind is closely allied to a concurrent process undertaken to examine environmental effects of marine and hydrokinetic (MHK) energy generation, although specific risk-relevant attributes will differ between the MHK and offshore wind domains. During FY10, a conceptual design of ERES for offshore wind will be developed. The offshore wind ERES mockup described in this report will provide a preview of the functionality of a fully developed risk evaluation system that will use risk assessment techniques to determine priority stressors on aquatic organisms and environments from specific technology aspects, identify key uncertainties underlying high-risk issues, compile a wide-range of data types in an innovative and flexible data organizing scheme, and inform planning and decision processes with a transparent and technically robust decision-support tool. A fully functional version of ERES for offshore wind will be developed in a subsequent phase of the project.

  13. First status report on regional and local ground-water flow modeling for Richton Dome, Mississippi

    International Nuclear Information System (INIS)

    Andrews, R.W.; Metcalfe, D.E.

    1984-03-01

    Regional and local ground-water flow within the principal hydrogeologic units in the vicinity of Richton Dome is evaluated by developing conceptual models of the flow regime within these units at three different scales and testing these models using a three-dimensional, finite-difference flow code. Semiquantitative sensitivity analysis is conducted to define the system response to changes in the conceptual model, particularly the hydrologic properties. The effects of salinity on the flow field are evaluated at the refined and local scales. Adjoint sensitivity analysis is applied to the conceptualized flow regime in the Wilcox aquifer. All steps leading to the final results and conclusions are incorporated in this report. The available data utilized in this study is summarized. The specific conceptual models, defining the areal and vertical averaging of lithologic units, aquifer properties, fluid properties, and hydrologic boundary conditions, are described in detail. The results are delineated by the simulated potentiometric surfaces and tables summarizing areal and vertical boundary fluxes, Darcy velocities at specific points, and ground-water travel paths. These results are presented at regional, refined, and local (near-dome) scales. The reported work is the first stage of an ongoing evaluation of the Richton Dome as a potential repository for high-level radioactive wastes. The results and conclusions should thus be considered preliminary and subject to modification with the collection of additional data. However, this report does provide a useful basis for describing the sensitivity and, to a lesser extent, the uncertainty of the present conceptualization of ground-water flow in the vicinity of Richton Dome. 25 references, 69 figures, 15 tables

  14. Regression modeling of ground-water flow

    Science.gov (United States)

    Cooley, R.L.; Naff, R.L.

    1985-01-01

    Nonlinear multiple regression methods are developed to model and analyze groundwater flow systems. Complete descriptions of regression methodology as applied to groundwater flow models allow scientists and engineers engaged in flow modeling to apply the methods to a wide range of problems. Organization of the text proceeds from an introduction that discusses the general topic of groundwater flow modeling, to a review of basic statistics necessary to properly apply regression techniques, and then to the main topic: exposition and use of linear and nonlinear regression to model groundwater flow. Statistical procedures are given to analyze and use the regression models. A number of exercises and answers are included to exercise the student on nearly all the methods that are presented for modeling and statistical analysis. Three computer programs implement the more complex methods. These three are a general two-dimensional, steady-state regression model for flow in an anisotropic, heterogeneous porous medium, a program to calculate a measure of model nonlinearity with respect to the regression parameters, and a program to analyze model errors in computed dependent variables such as hydraulic head. (USGS)

  15. Modeling Submarine Lava Flow with ASPECT

    Science.gov (United States)

    Storvick, E. R.; Lu, H.; Choi, E.

    2017-12-01

    Submarine lava flow is not easily observed and experimented on due to limited accessibility and challenges posed by the fast solidification of lava and the associated drastic changes in rheology. However, recent advances in numerical modeling techniques might address some of these challenges and provide unprecedented insight into the mechanics of submarine lava flow and conditions determining its wide-ranging morphologies. In this study, we explore the applicability ASPECT, Advanced Solver for Problems in Earth's ConvecTion, to submarine lava flow. ASPECT is a parallel finite element code that solves problems of thermal convection in the Earth's mantle. We will assess ASPECT's capability to model submarine lava flow by observing models of lava flow morphology simulated with GALE, a long-term tectonics finite element analysis code, with models created using comparable settings and parameters in ASPECT. From these observations we will contrast the differing models in order to identify the benefits of each code. While doing so, we anticipate we will learn about the conditions required for end-members of lava flow morphology, for example, pillows and sheet flows. With ASPECT specifically we focus on 1) whether the lava rheology can be implemented; 2) how effective the AMR is in resolving morphologies of the solidified crust; 3) whether and under what conditions the end-members of the lava flow morphologies, pillows and sheets, can be reproduced.

  16. Groundwater flow modelling under ice sheet conditions. Scoping calculations

    Energy Technology Data Exchange (ETDEWEB)

    Jaquet, O.; Namar, R. (In2Earth Modelling Ltd (Switzerland)); Jansson, P. (Dept. of Physical Geography and Quaternary Geology, Stockholm Univ., Stockholm (Sweden))

    2010-10-15

    program DarcyTools in order to evaluate the current conceptual model for groundwater flow under ice sheet conditions, as well as to provide some guidance to the field investigations. For this first modelling phase, coupled processes are not considered for the modelling of the groundwater flow system under ice sheet conditions; e.g. density driven flow, thermal and geomechanical effects as well as coupling with a dynamical ice sheet model shall be investigated in the next phase

  17. Groundwater flow modelling under ice sheet conditions. Scoping calculations

    International Nuclear Information System (INIS)

    Jaquet, O.; Namar, R.; Jansson, P.

    2010-10-01

    program DarcyTools in order to evaluate the current conceptual model for groundwater flow under ice sheet conditions, as well as to provide some guidance to the field investigations. For this first modelling phase, coupled processes are not considered for the modelling of the groundwater flow system under ice sheet conditions; e.g. density driven flow, thermal and geomechanical effects as well as coupling with a dynamical ice sheet model shall be investigated in the next phase

  18. Using a lumped conceptual hydrological model for five different catchments in Sweden

    OpenAIRE

    Ekenberg, Madeleine

    2016-01-01

    Hydrological models offer powerful tools for understanding and predicting. In this thesis we havereviewed the advantages and disadvantages of physically based distributed hydrological models andconceptually lumped hydrological models. Based on that review, we went into depth and developed aMATLAB code to test if a simple conceptual lumped hydrological model, namely GR2M, wouldperform satisfactory for five different catchments in different parts of Sweden. The model had ratherunsatisfactory re...

  19. Conceptual design of an integrated technology model for carbon policy assessment.

    Energy Technology Data Exchange (ETDEWEB)

    Backus, George A.; Dimotakes, Paul E. (NASA Jet Propulsion Laboratory, Pasadena, CA)

    2011-01-01

    This report describes the conceptual design of a technology choice model for understanding strategies to reduce carbon intensity in the electricity sector. The report considers the major modeling issues affecting technology policy assessment and defines an implementable model construct. Further, the report delineates the basis causal structure of such a model and attempts to establish the technical/algorithmic viability of pursuing model development along with the associated analyses.

  20. The Prince Edward Island Conceptual Model for Nursing: a nursing perspective of primary health care.

    Science.gov (United States)

    Munro, M; Gallant, M; MacKinnon, M; Dell, G; Herbert, R; MacNutt, G; McCarthy, M J; Murnaghan, D; Robertson, K

    2000-06-01

    The philosophy of primary health care (PHC) recognizes that health is a product of individual, social, economic, and political factors and that people have a right and a duty, individually and collectively, to participate in the course of their own health. The majority of nursing models cast the client in a dependent role and do not conceptualize health in a social, economic, and political context. The Prince Edward Island Conceptual Model for Nursing is congruent with the international move towards PHC. It guides the nurse in practising in the social and political environment in which nursing and health care take place. This model features a nurse/client partnership, the goal being to encourage clients to act on their own behalf. The conceptualization of the environment as the collective influence of the determinants of health gives both nurse and client a prominent position in the sociopolitical arena of health and health care.

  1. Conceptual Model of Iodine Behavior in the Subsurface at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lee, Brady D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Christian D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Qafoku, Nikolla P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Last, George V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lee, Michelle H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kaplan, Daniel I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-09-01

    The fate and transport of 129I in the environment and potential remediation technologies are currently being studied as part of environmental remediation activities at the Hanford Site. A conceptual model describing the nature and extent of subsurface contamination, factors that control plume behavior, and factors relevant to potential remediation processes is needed to support environmental remedy decisions. Because 129I is an uncommon contaminant, relevant remediation experience and scientific literature are limited. Thus, the conceptual model also needs to both describe known contaminant and biogeochemical process information and to identify aspects about which additional information needed to effectively support remedy decisions. this document summarizes the conceptual model of iodine behavior relevant to iodine in the subsurface environment at the Hanford site.

  2. Examining the Etiology of Reading Disability as Conceptualized by the Hybrid Model

    Science.gov (United States)

    Erbeli, Florina; Hart, Sara A.; Wagner, Richard K.; Taylor, Jeanette

    2018-01-01

    A fairly recent definition of reading disability (RD) is that in the form of a hybrid model. The model views RD as a latent construct that is manifested through various observable unexpected impairments in reading-related skills and through inadequate response to intervention. The current report evaluated this new conceptualization of RD from an…

  3. Career and Technical Education (CTE) Student Success in Community Colleges: A Conceptual Model

    Science.gov (United States)

    Hirschy, Amy S.; Bremer, Christine D.; Castellano, Marisa

    2011-01-01

    Career and technical education (CTE) students pursuing occupational associate's degrees or certificates differ from students seeking academic majors at 2-year institutions in several ways. This article examines several theoretical models of student persistence and offers a conceptual model of student success focused on CTE students in community…

  4. Regime transitions in near-surface temperature inversions : a conceptual model

    NARCIS (Netherlands)

    van de Wiel, B.J.H.; Vignon, E.; Baas, P.; Bosveld, F.C.; de Roode, S.R.; Moene, A.F.; Genthon, C.; van der Linden, Steven J.A.; van Hooft, J. Antoon; van Hooijdonk, I.G.S.

    2017-01-01

    A conceptual model is used in combination with observational analysis to understand regime transitions of near-surface temperature inversions at night as well as in Arctic conditions. The model combines a surface energy budget with a bulk parameterization for turbulent heat transport. Energy fluxes

  5. University Library Strategy Development: A Conceptual Model of Researcher Performance to Inform Service Delivery

    Science.gov (United States)

    Maddox, Alexia; Zhao, Linlin

    2017-01-01

    This case study presents a conceptual model of researcher performance developed by Deakin University Library, Australia. The model aims to organize research performance data into meaningful researcher profiles, referred to as researcher typologies, which support the demonstration of research impact and value. Three dimensions shaping researcher…

  6. The Conceptualization of the Mathematical Modelling Process in Technology-Aided Environment

    Science.gov (United States)

    Hidiroglu, Çaglar Naci; Güzel, Esra Bukova

    2017-01-01

    The aim of the study is to conceptualize the technology-aided mathematical modelling process in the frame of cognitive modelling perspective. The grounded theory approach was adopted in the study. The research was conducted with seven groups consisting of nineteen prospective mathematics teachers. The data were collected from the video records of…

  7. Conceptual Resources in Self-Developed Explanatory Models: The Importance of Integrating Conscious and Intuitive Knowledge

    Science.gov (United States)

    Cheng, Meng-Fei; Brown, David E.

    2010-01-01

    This study explores the spontaneous explanatory models children construct, critique, and revise in the context of tasks in which children need to predict, observe, and explain phenomena involving magnetism. It further investigates what conceptual resources students use, and in what ways they use them, to construct explanatory models, and the…

  8. Conceptualization of an R&D Based Learning-to-Innovate Model for Science Education

    Science.gov (United States)

    Lai, Oiki Sylvia

    2013-01-01

    The purpose of this research was to conceptualize an R & D based learning-to-innovate (LTI) model. The problem to be addressed was the lack of a theoretical L TI model, which would inform science pedagogy. The absorptive capacity (ACAP) lens was adopted to untangle the R & D LTI phenomenon into four learning processes: problem-solving via…

  9. A model for information retrieval driven by conceptual spaces

    OpenAIRE

    Tanase, D.

    2015-01-01

    A retrieval model describes the transformation of a query into a set of documents. The question is: what drives this transformation? For semantic information retrieval type of models this transformation is driven by the content and structure of the semantic models. In this case, Knowledge Organization Systems (KOSs) are the semantic models that encode the meaning employed for monolingual and cross-language retrieval. The focus of this research is the relationship between these meanings’ repre...

  10. Conceptual Models, Choices, and Benchmarks for Building Quality Work Cultures.

    Science.gov (United States)

    Acker-Hocevar, Michele

    1996-01-01

    The two models in Florida's Educational Quality Benchmark System represent a new way of thinking about developing schools' work culture. The Quality Performance System Model identifies nine dimensions of work within a quality system. The Change Process Model provides a theoretical framework for changing existing beliefs, attitudes, and behaviors…

  11. Incorporating groundwater flow into the WEPP model

    Science.gov (United States)

    William Elliot; Erin Brooks; Tim Link; Sue Miller

    2010-01-01

    The water erosion prediction project (WEPP) model is a physically-based hydrology and erosion model. In recent years, the hydrology prediction within the model has been improved for forest watershed modeling by incorporating shallow lateral flow into watershed runoff prediction. This has greatly improved WEPP's hydrologic performance on small watersheds with...

  12. Mathematical modelling of two-phase flows

    International Nuclear Information System (INIS)

    Komen, E.M.J.; Stoop, P.M.

    1992-11-01

    A gradual shift from methods based on experimental correlations to methods based on mathematical models to study 2-phase flows can be observed. The latter can be used to predict dynamical behaviour of 2-phase flows. This report discusses various mathematical models for the description of 2-phase flows. An important application of these models can be found in thermal-hydraulic computer codes used for analysis of the thermal-hydraulic behaviour of water cooled nuclear power plants. (author). 17 refs., 7 figs., 6 tabs

  13. Computer-based Creativity Enhanced Conceptual Design Model for Non-routine Design of Mechanical Systems

    Institute of Scientific and Technical Information of China (English)

    LI Yutong; WANG Yuxin; DUFFY Alex H B

    2014-01-01

    Computer-based conceptual design for routine design has made great strides, yet non-routine design has not been given due attention, and it is still poorly automated. Considering that the function-behavior-structure(FBS) model is widely used for modeling the conceptual design process, a computer-based creativity enhanced conceptual design model(CECD) for non-routine design of mechanical systems is presented. In the model, the leaf functions in the FBS model are decomposed into and represented with fine-grain basic operation actions(BOA), and the corresponding BOA set in the function domain is then constructed. Choosing building blocks from the database, and expressing their multiple functions with BOAs, the BOA set in the structure domain is formed. Through rule-based dynamic partition of the BOA set in the function domain, many variants of regenerated functional schemes are generated. For enhancing the capability to introduce new design variables into the conceptual design process, and dig out more innovative physical structure schemes, the indirect function-structure matching strategy based on reconstructing the combined structure schemes is adopted. By adjusting the tightness of the partition rules and the granularity of the divided BOA subsets, and making full use of the main function and secondary functions of each basic structure in the process of reconstructing of the physical structures, new design variables and variants are introduced into the physical structure scheme reconstructing process, and a great number of simpler physical structure schemes to accomplish the overall function organically are figured out. The creativity enhanced conceptual design model presented has a dominant capability in introducing new deign variables in function domain and digging out simpler physical structures to accomplish the overall function, therefore it can be utilized to solve non-routine conceptual design problem.

  14. Computer-based creativity enhanced conceptual design model for non-routine design of mechanical systems

    Science.gov (United States)

    Li, Yutong; Wang, Yuxin; Duffy, Alex H. B.

    2014-11-01

    Computer-based conceptual design for routine design has made great strides, yet non-routine design has not been given due attention, and it is still poorly automated. Considering that the function-behavior-structure(FBS) model is widely used for modeling the conceptual design process, a computer-based creativity enhanced conceptual design model(CECD) for non-routine design of mechanical systems is presented. In the model, the leaf functions in the FBS model are decomposed into and represented with fine-grain basic operation actions(BOA), and the corresponding BOA set in the function domain is then constructed. Choosing building blocks from the database, and expressing their multiple functions with BOAs, the BOA set in the structure domain is formed. Through rule-based dynamic partition of the BOA set in the function domain, many variants of regenerated functional schemes are generated. For enhancing the capability to introduce new design variables into the conceptual design process, and dig out more innovative physical structure schemes, the indirect function-structure matching strategy based on reconstructing the combined structure schemes is adopted. By adjusting the tightness of the partition rules and the granularity of the divided BOA subsets, and making full use of the main function and secondary functions of each basic structure in the process of reconstructing of the physical structures, new design variables and variants are introduced into the physical structure scheme reconstructing process, and a great number of simpler physical structure schemes to accomplish the overall function organically are figured out. The creativity enhanced conceptual design model presented has a dominant capability in introducing new deign variables in function domain and digging out simpler physical structures to accomplish the overall function, therefore it can be utilized to solve non-routine conceptual design problem.

  15. A conceptual framework for the integration of flow theory and cognitive evaluation theory

    OpenAIRE

    Abuhamdeh, Sami

    2012-01-01

    Flow theory (Csikszentmihalyi, Beyond boredom and anxiety: Experiencing flow in work and play. Jossey-Bass, San Francisco, 1975) and cognitive evaluation theory (Deci and Ryan, Intrinsic motivation and self-determination in human behaviour. Plenum, New York, 1985) have each inspired a large body of research dedicated to understanding why we enjoy doing what we enjoy doing. Although both theories ostensibly address the same category of behavior—namely, intrinsically motivated behavior—there ha...

  16. Conceptual model of fractured aquifer of Uranium Deposit in Caetité, Bahia: implications for groundwater flow; Modelo conceitual do aquífero fraturado da área da jazida de urânio de Caetité, Bahia: implicações para o fluxo subterrâneo

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Liliane Ferreira da

    2015-07-01

    The studied area is represented by the uraniferous district of Lagoa Real, located in the center-south of Bahia State, Brazil. The region is set in a semiarid climate context, with hot and dry weather parameters, with hydric deficit along all months of the year and high aridity index. Rural population is affected on drought periods since small agriculture and animal rearing are the main economic activities which are vulnerable in dry seasons. Groundwater represents the main supply source considering that most surface water sources are temporary and only exhibit flow in rainy periods. The main aquifer system present on the region is fractured, and the presence of groundwater flow occurs through the discontinuities of the rock considering that the rock mass corresponds to the set formed by the rock matrix and all its discontinuities (fractures, foliations, discordance, etc). In this sense, the main purpose of this Master Dissertation was to develop a conceptual model for the aquifer system, through the geotechnical characterization of discontinuities, once these structures allow the secondary porosity of the medium. Hydrochemical data hand out as complement for physical characterization for the behavioral interpretation of the aquifer. The aquifer system is unconfined, however, presents points of stagnation of flow forming compartments without communication with the surrounding areas. According to the International Society of Rock Mechanics ISRM method, which consist on qualitative and quantitative characterization of discontinuities of rock mass scanlines were constructed, systematically, describing, the following structure parameters: attitude, spacing, persistence, openness, infilling and roughness. From the results analysis it could be concluded that the aquifer system is composed of three discontinuities sets: one set which dips to NE, second set dipping to SW-W-NW and the last set sub-horizontal. The first and second sets are responsible for the aquifer

  17. A conceptual data model and modelling language for fields and agents

    Science.gov (United States)

    de Bakker, Merijn; de Jong, Kor; Schmitz, Oliver; Karssenberg, Derek

    2016-04-01

    Modelling is essential in order to understand environmental systems. Environmental systems are heterogeneous because they consist of fields and agents. Fields have a value defined everywhere at all times, for example surface elevation and temperature. Agents are bounded in space and time and have a value only within their bounds, for example biomass of a tree crown or the speed of a car. Many phenomena have properties of both fields and agents. Although many systems contain both fields and agents and integration of these concepts would be required for modelling, existing modelling frameworks concentrate on either agent-based or field-based modelling and are often low-level programming frameworks. A concept is lacking that integrates fields and agents in a way that is easy to use for modelers who are not software engineers. To address this issue, we develop a conceptual data model that represents fields and agents uniformly. We then show how the data model can be used in a high-level modelling language. The data model represents fields and agents in space-time. Also relations and networks can be represented using the same concepts. Using the conceptual data model we can represent static and mobile agents that may have spatial and temporal variation within their extent. The concepts we use are phenomenon, property set, item, property, domain and value. The phenomenon is the thing that is modelled, which can be any real world thing, for example trees. A phenomenon usually consists of several items, e.g. single trees. The domain is the spatiotemporal location and/or extent for which the items in the phenomenon are defined. Multiple different domains can coexist for a given phenomenon. For example a domain describing the extent of the trees and a domain describing the stem locations. The same goes for the property, which is an attribute of the thing that is being modeled. A property has a value, which is possibly discretized, for example the biomass over the tree crown

  18. On the practical modeling of conceptual overlap among multiple facets in ontology domain concepts (Mini-thesis)

    OpenAIRE

    Rodriguez-Castro, Benedicto; Glaser, Hugh; Carr, Leslie

    2007-01-01

    This report presents a study on the practical modelling of the conceptual overlap that might exist among the multiple facets that define a particular ontology domain concept. The notions of conceptual overlap and facet are defined, together with their relation to scenarios of multiple inheritance in ontology models. Starting from the notion of a value partition, a terminology of ontology modelling constructs is introduced that allows the characterization of two types of conceptual overlap wit...

  19. A Conceptual Model for Engagement of the Online Learner

    OpenAIRE

    Lorraine M. Angelino; Deborah Natvig

    2009-01-01

    Engagement of the online learner is one approach to reduce attrition rates. Attrition rates for classes taught through distance education are 10 – 20% higher than classes taught in a face-to-face setting. This paper introduces a Model for Engagement and provides strategies to engage the online learner. The Model depicts various opportunities where student-instructor, student-student, student-content, and student-community engagement can occur. The Model is divided into four strategic areas: (...

  20. An independent verification and validation of the Future Theater Level Model conceptual model

    Energy Technology Data Exchange (ETDEWEB)

    Hartley, D.S. III; Kruse, K.L.; Martellaro, A.J.; Packard, S.L.; Thomas, B. Jr.; Turley, V.K.

    1994-08-01

    This report describes the methodology and results of independent verification and validation performed on a combat model in its design stage. The combat model is the Future Theater Level Model (FTLM), under development by The Joint Staff/J-8. J-8 has undertaken its development to provide an analysis tool that addresses the uncertainties of combat more directly than previous models and yields more rapid study results. The methodology adopted for this verification and validation consisted of document analyses. Included were detailed examination of the FTLM design documents (at all stages of development), the FTLM Mission Needs Statement, and selected documentation for other theater level combat models. These documents were compared to assess the FTLM as to its design stage, its purpose as an analytical combat model, and its capabilities as specified in the Mission Needs Statement. The conceptual design passed those tests. The recommendations included specific modifications as well as a recommendation for continued development. The methodology is significant because independent verification and validation have not been previously reported as being performed on a combat model in its design stage. The results are significant because The Joint Staff/J-8 will be using the recommendations from this study in determining whether to proceed with develop of the model.

  1. The service dominant business model : a service focused conceptualization

    NARCIS (Netherlands)

    Lüftenegger, E.R.; Comuzzi, M.; Grefen, P.W.P.J.; Weisleder, C.A.

    2013-01-01

    Existing approaches on business model tools are constrained by the goods dominant way of doing business. Nowadays, the shift from goods based approaches towards a service dominant strategy requires novel business model tools specially focused for service business. In this report we present the

  2. The Conceptual Framework of Factors Affecting Shared Mental Model

    Science.gov (United States)

    Lee, Miyoung; Johnson, Tristan; Lee, Youngmin; O'Connor, Debra; Khalil, Mohammed

    2004-01-01

    Many researchers have paid attention to the potentiality and possibility of the shared mental model because it enables teammates to perform their job better by sharing team knowledge, skills, attitudes, dynamics and environments. Even though theoretical and experimental evidences provide a close relationship between the shared mental model and…

  3. A Conceptual Model of Leisure-Time Choice Behavior.

    Science.gov (United States)

    Bergier, Michel J.

    1981-01-01

    Methods of studying the gap between predisposition and actual behavior of consumers of spectator sports is discussed. A model is drawn from the areas of behavioral sciences, consumer behavior, and leisure research. The model is constructed around the premise that choice is primarily a function of personal, product, and environmental factors. (JN)

  4. Integrated soft sensor model for flow control.

    Science.gov (United States)

    Aijälä, G; Lumley, D

    2006-01-01

    Tighter discharge permits often require wastewater treatment plants to maximize utilization of available facilities in order to cost-effectively reach these goals. Important aspects are minimizing internal disturbances and using available information in a smart way to improve plant performance. In this study, flow control throughout a large highly automated wastewater treatment plant (WWTP) was implemented in order to reduce internal disturbances and to provide a firm foundation for more advanced process control. A modular flow control system was constructed based on existing instrumentation and soft sensor flow models. Modules were constructed for every unit process in water treatment and integrated into a plant-wide model. The flow control system is used to automatically control recirculation flows and bypass flows at the plant. The system was also successful in making accurate flow estimations at points in the plant where it is not possible to have conventional flow meter instrumentation. The system provides fault detection for physical flow measuring devices. The module construction allows easy adaptation for new unit processes added to the treatment plant.

  5. 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.

  6. 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

  7. Modeling of two-phase slug flow

    International Nuclear Information System (INIS)

    Fabre, J.; Line, A.

    1992-01-01

    When gas and liquid flow in a pipe, over a range of flow rates, a flow pattern results in which sequences of long bubbles, almost filling the pipe cross section, are successively followed by liquid slugs that may contain small bubbles. This flow pattern, usually called slug flow, is encountered in numerous practical situations, such as in the production of hydrocarbons in wells and their transportation in pipelines; the production of steam and water in geothermal power plants; the boiling and condensation in liquid-vapor systems of thermal power plants; emergency core cooling of nuclear reactors; heat and mass transfer between gas and liquid in chemical reactors. This paper provides a review of two phase slug flow modeling

  8. Flow model study of 'Monju' reactor vessel

    International Nuclear Information System (INIS)

    Miyaguchi, Kimihide

    1980-01-01

    In the case of designing the structures in nuclear reactors, various problems to be considered regarding thermo-hydrodynamics exist, such as the distribution of flow quantity and the pressure loss in reactors and the thermal shock to inlet and outlet nozzles. In order to grasp the flow characteristics of coolant in reactors, the 1/2 scale model of the reactor structure of ''Monju'' was attached to the water flow testing facility in the Oarai Engineering Center, and the simulation experiment has been carried out. The flow characteristics in reactors clarified by experiment and analysis so far are the distribution of flow quantity between high and low pressure regions in reactors, the distribution of flow quantity among flow zones in respective regions of high and low pressure, the pressure loss in respective parts in reactors, the flow pattern and the mixing effect of coolant in upper and lower plenums, the effect of the twisting angle of inlet nozzles on the flow characteristics in lower plenums, the effect of internal cylinders on the flow characteristics in upper plenums and so on. On the basis of these test results, the improvement of the design of structures in reactors was made, and the confirmation test on the improved structures was carried out. The testing method, the calculation method, the test results and the reflection to the design of actual machines are described. (Kako, I.)

  9. Literature Review of Enterprise Systems Research Using Institutional Theory: Towards a Conceptual Model

    DEFF Research Database (Denmark)

    Svejvig, Per

    This paper sets out to examine the use of institutional theory as a conceptually rich lens to study social issues of enterprise systems (ES) research. More precisely, the purpose is to categorize current ES research using institutional theory to develop a conceptual model that advances ES research...... model which advocates for multi-level and multi-theory approaches, and applies newer institutional aspects such as institutional logics. The findings show that institutional theory in ES research is in its infancy and adopts mainly traditional institutional aspects like isomorphism....... Key institutional features are presented such as isomorphism, rationalized myths, bridging macro and micro structures, and institutional logics and their implications for ES research are discussed. Through a literature review of 180 articles, of which 18 papers are selected, we build a conceptual...

  10. NUMERICAL SIMULATION AND MODELING OF UNSTEADY FLOW ...

    African Journals Online (AJOL)

    2014-06-30

    Jun 30, 2014 ... objective of this study is to control the simulation of unsteady flows around structures. ... Aerospace, our results were in good agreement with experimental .... Two-Equation Eddy-Viscosity Turbulence Models for Engineering.

  11. Base Flow Model Validation, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The program focuses on turbulence modeling enhancements for predicting high-speed rocket base flows. A key component of the effort is the collection of high-fidelity...

  12. Numerical models of groundwater flow and transport

    International Nuclear Information System (INIS)

    Konikow, L.F.

    1996-01-01

    This chapter reviews the state-of-the-art in deterministic modeling of groundwater flow and transport processes, which can be used for interpretation of isotope data through groundwater flow analyses. Numerical models which are available for this purpose are described and their applications to complex field problems are discussed. The theoretical bases of deterministic modeling are summarized, and advantages and limitations of numerical models are described. The selection of models for specific applications and their calibration procedures are described, and results of a few illustrative case study type applications are provided. (author). 145 refs, 17 figs, 2 tabs

  13. Numerical models of groundwater flow and transport

    Energy Technology Data Exchange (ETDEWEB)

    Konikow, L F [Geological Survey, Reston, VA (United States)

    1996-10-01

    This chapter reviews the state-of-the-art in deterministic modeling of groundwater flow and transport processes, which can be used for interpretation of isotope data through groundwater flow analyses. Numerical models which are available for this purpose are described and their applications to complex field problems are discussed. The theoretical bases of deterministic modeling are summarized, and advantages and limitations of numerical models are described. The selection of models for specific applications and their calibration procedures are described, and results of a few illustrative case study type applications are provided. (author). 145 refs, 17 figs, 2 tabs.

  14. Improved choked flow model for MARS code

    International Nuclear Information System (INIS)

    Chung, Moon Sun; Lee, Won Jae; Ha, Kwi Seok; Hwang, Moon Kyu

    2002-01-01

    Choked flow calculation is improved by using a new sound speed criterion for bubbly flow that is derived by the characteristic analysis of hyperbolic two-fluid model. This model was based on the notion of surface tension for the interfacial pressure jump terms in the momentum equations. Real eigenvalues obtained as the closed-form solution of characteristic polynomial represent the sound speed in the bubbly flow regime that agrees well with the existing experimental data. The present sound speed shows more reasonable result in the extreme case than the Nguyens did. The present choked flow criterion derived by the present sound speed is employed in the MARS code and assessed by using the Marviken choked flow tests. The assessment results without any adjustment made by some discharge coefficients demonstrate more accurate predictions of choked flow rate in the bubbly flow regime than those of the earlier choked flow calculations. By calculating the Typical PWR (SBLOCA) problem, we make sure that the present model can reproduce the reasonable transients of integral reactor system

  15. Modeling groundwater flow and quality

    Science.gov (United States)

    Konikow, Leonard F.; Glynn, Pierre D.; Selinus, Olle

    2013-01-01

    In most areas, rocks in the subsurface are saturated with water at relatively shallow depths. The top of the saturated zone—the water table—typically occurs anywhere from just below land surface to hundreds of feet below the land surface. Groundwater generally fills all pore spaces below the water table and is part of a continuous dynamic flow system, in which the fluid is moving at velocities ranging from feet per millennia to feet per day (Fig. 33.1). While the water is in close contact with the surfaces of various minerals in the rock material, geochemical interactions between the water and the rock can affect the chemical quality of the water, including pH, dissolved solids composition, and trace-elements content. Thus, flowing groundwater is a major mechanism for the transport of chemicals from buried rocks to the accessible environment, as well as a major pathway from rocks to human exposure and consumption. Because the mineral composition of rocks is highly variable, as is the solubility of various minerals, the human-health effects of groundwater consumption will be highly variable.

  16. Penerapan Model Pembelajaran Conceptual Understanding Procedures (CUPS sebagai Upaya Mengatasi Miskonsepsi Matematis Siswa

    Directory of Open Access Journals (Sweden)

    Asri Gita

    2018-01-01

    Full Text Available Kesalahan dalam memahami konsep menjadi salah satu faktor yang menyebabkan miskonsepsi pada pelajaran matematika. Miskonsepsi pada materi bangun datar disebabkan oleh cara belajar siswa yang hanya menghafalkan bentuk dasar tanpa memahami hubungan antar bangun datar dan sifat-sifatnya. Upaya yang dilakukan dalam mengatasi miskonsepsi tersebut adalah dengan menerapkan pembelajaran konstruktivis. Salah satu model pembelajaran konstruktivis adalah Conceptual Understanding Procedures (CUPs. Tujuan dari penelitian ini adalah untuk mengetahui penerapan model pembelajaran Conceptual Understanding Procedures (CUPs sebagai upaya mengatasi miskonsepsi matematis siswa pada materi sifat-sifat bangun datar segiempat. Subjek penelitian adalah 12 orang siswa SMP yang mengalami miskonsepsi pada materi sifat-sifat bangun datar segiempat. Teknik pengumpulan data pada penelitian ini melalui tes, video, observasi, dan wawancara. Validitas dan reliabilitas data melalui credibility, dependability, transferability, dan confirmability. Hasil dari penelitian ini menunjukkan bahwa penerapan model pembelajaran Conceptual Understanding Procedures (CUPs yang terdiri dari fase individu, fase kelompok triplet, dan fase interpretasi seluruh kelas dapat mengatasi miskonsepsi siswa pada materi sifat-sifat bangun datar segiempat. Perubahan miskonsepsi siswa juga dapat dilihat dari nilai tes yang mengalami peningkatan nilai berdasarkan nilai tes awal dan tes akhir siswa. Kata Kunci: Conceptual Understanding Procedures (CUPs, miskonsepsi, segiempat.   ABSTRACT Mistakes in understanding the concept became one of the factors that led to misconceptions in mathematics. The misconceptions in plane shapes are caused by the way of learning of students who only memorize the basic form without understanding the relationship between the plane shapes and its properties. Efforts made in overcoming these misconceptions is to apply constructivist learning. One of the constructivist learning

  17. A Proposed Conceptual Model to Measure Unwarranted Practice Variation

    National Research Council Canada - National Science Library

    Barr, Andrew M

    2007-01-01

    .... Employing a unit of analysis of the U.S. Army healthcare system and utilizing research by Wennberg and the Institute of Medicine, a model describing healthcare quality in terms of unwarranted practice variation and healthcare outcomes...

  18. A Proposed Conceptual Model of Military Medical Readiness

    National Research Council Canada - National Science Library

    Van Hall, Brian M

    2007-01-01

    .... The purpose of this research is to consolidate existing literature on the latent variable of medical readiness, and to propose a composite theoretical model of medical readiness that may provide...

  19. Public–private partnership conceptual framework and models for the ...

    African Journals Online (AJOL)

    investment and inefficiencies within the public expenditure management systems are particularly detrimental, e.g., there .... a consolidation of different views, ideas, perceptions and ... contingency) exists between the PPP models key financial.

  20. Conceptual Modeling of Events as Information Objects and Change Agents

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    as a totality of an information object and a change agent. When an event is modeled as an information object it is comparable to an entity that exists only at a specific point in time. It has attributes and can be used for querying and specification of constraints. When an event is modeled as a change agent...... it is comparable to an executable transaction schema. Finally, we briefly compare our approach to object-oriented approaches based on encapsulated objects....

  1. Modelling of Emulsion Flow in Porous Media

    Energy Technology Data Exchange (ETDEWEB)

    Abou-Kassem, J.H. [UAE University (United Arab Emirates); Farouq Ali, S.M. [UAE University (United Arab Emirates)

    1995-06-01

    Oil recovery methods predominantly involve emulsion formation. Oil recovery simulation requires the incorporation of emulsion characteristics and flow in porous media, in order to optimize oil recovery from petroleum reservoirs. This paper explored the nature and rheology of emulsions, and evaluated several models of flow of Newtonian and non-Newtonian fluids in porous media. It also summarized in situ emulsion formation in porous media. A model for both Newtonian and non-Newtonian emulsion fluid flow was proposed, with special emphasis on pore size, and tortuosity in the porous media.

  2. Modelling and control of systems with flow

    NARCIS (Netherlands)

    van Mourik, S.

    2008-01-01

    In practice, feedback control design consists of three steps: modelling, model reduction and controller design for the reduced model. Systems with flow are often complicated, and there is yet no standard algorithm that integrates these steps. In this thesis we make a modest effort by considering two

  3. Conceptual model for quality of life among adults with congenital or early deafness.

    Science.gov (United States)

    Kushalnagar, Poorna; McKee, Michael; Smith, Scott R; Hopper, Melinda; Kavin, Denise; Atcherson, Samuel R

    2014-07-01

    A conceptual model of health-related quality of life (QoL) is needed to describe key themes that impact perceived QoL in adults with congenital or early deafness. To revise University of Washington Center for Disability Policy and Research's conceptual model of health promotion and QoL, with suggestions for applying the model to improving programs or services that target deaf adults with early deafness. Purposive and theoretical sampling of 35 adults who were born or became deaf early was planned in a 1-year study. In-depth semi-structured interviews probed deaf adult participants' perceptions about quality of life as a deaf individual. Data saturation was reached at the 17th interview with 2 additional interviews for validation, resulting in a total sample of 19 deaf adults. Coding and thematic analysis were conducted to develop the conceptual model. Our conceptual model delineates the relationships between health status (self-acceptance, coping with limitations), intrinsic (functional communication skills, navigating barriers/self-advocacy, resilience) and extrinsic (acceptance by others, access to information, educating others) factors in their influence on deaf adult quality of life outcomes at home, college, work, and in the community. Findings demonstrate the need for the programs and services to consider not only factors intrinsic to the deaf individual but also extrinsic factors in enhancing perceived quality of life outcomes among people with a range of functional hearing and language preferences, including American Sign Language. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Amendment to Validated dynamic flow model

    DEFF Research Database (Denmark)

    Knudsen, Torben

    2011-01-01

    The purpose of WP2 is to establish flow models relating the wind speed at turbines in a farm. Until now, active control of power reference has not been included in these models as only data with standard operation has been available. In this report the first data series with power reference excit...... turbine in undisturbed flow. For this data set both the multiplicative model and in particular the simple first order transfer function model can predict the down wind wind speed from upwind wind speed and loading.......The purpose of WP2 is to establish flow models relating the wind speed at turbines in a farm. Until now, active control of power reference has not been included in these models as only data with standard operation has been available. In this report the first data series with power reference...

  5. A rigorous test for a new conceptual model for collisions

    International Nuclear Information System (INIS)

    Peixoto, E.M.A.; Mu-Tao, L.

    1979-01-01

    A rigorous theoretical foundation for the previously proposed model is formulated and applied to electron scattering by H 2 in the gas phase. An rigorous treatment of the interaction potential between the incident electron and the Hydrogen molecule is carried out to calculate Differential Cross Sections for 1 KeV electrons, using Glauber's approximation Wang's molecular wave function for the ground electronic state of H 2 . Moreover, it is shown for the first time that, when adequately done, the omission of two center terms does not adversely influence the results of molecular calculations. It is shown that the new model is far superior to the Independent Atom Model (or Independent Particle Model). The accuracy and simplicity of the new model suggest that it may be fruitfully applied to the description of other collision phenomena (e.g., in molecular beam experiments and nuclear physics). A new techniques is presented for calculations involving two center integrals within the frame work of the Glauber's approximation for scattering. (Author) [pt

  6. Conceptual hierarchical modeling to describe wetland plant community organization

    Science.gov (United States)

    Little, A.M.; Guntenspergen, G.R.; Allen, T.F.H.

    2010-01-01

    Using multivariate analysis, we created a hierarchical modeling process that describes how differently-scaled environmental factors interact to affect wetland-scale plant community organization in a system of small, isolated wetlands on Mount Desert Island, Maine. We followed the procedure: 1) delineate wetland groups using cluster analysis, 2) identify differently scaled environmental gradients using non-metric multidimensional scaling, 3) order gradient hierarchical levels according to spatiotem-poral scale of fluctuation, and 4) assemble hierarchical model using group relationships with ordination axes and post-hoc tests of environmental differences. Using this process, we determined 1) large wetland size and poor surface water chemistry led to the development of shrub fen wetland vegetation, 2) Sphagnum and water chemistry differences affected fen vs. marsh / sedge meadows status within small wetlands, and 3) small-scale hydrologic differences explained transitions between forested vs. non-forested and marsh vs. sedge meadow vegetation. This hierarchical modeling process can help explain how upper level contextual processes constrain biotic community response to lower-level environmental changes. It creates models with more nuanced spatiotemporal complexity than classification and regression tree procedures. Using this process, wetland scientists will be able to generate more generalizable theories of plant community organization, and useful management models. ?? Society of Wetland Scientists 2009.

  7. Conceptualization of flow and transport in a limestone aquifer by multiple dedicated hydraulic and tracer tests

    DEFF Research Database (Denmark)

    Mosthaf, Klaus; Brauns, Bentje; Fjordbøge, Annika Sidelmann

    2018-01-01

    Limestone aquifers are of great interest as a drinking water resource in many countries. They often have a complex crushed and fractured geology, which makes the analysis and description of flow and transport processes in such aquifers a challenging task. In this study, the solute transport behav...

  8. A study on modeling customer preferences for conceptual design

    International Nuclear Information System (INIS)

    Han, Soon Young; Seo, Seok Hoon; Choi, Hae Jin

    2015-01-01

    In this paper, we propose a concept selection method to evaluate future market performances of concept candidates, and to choose the best concept among those. The main and interaction effects of product performance factors, economic factors, and time on a market performance are modeled using a Bayesian framework-based Artificial neural network (ANN). The Bayesian framework is employed to measure the potential risk of wrong selection in using a trained ANN model. Based on the measured uncertainty bounds in the predicted future market performance, the most promising and robust concept may be selected. To validate our concept-selection method, we employed an automobile concept selection problem in the U.S. market. Seventeen concepts were assumed to compete in 2013, and the future market share with error bounds was predicted using the trained model based on sale data

  9. A study on modeling customer preferences for conceptual design

    Energy Technology Data Exchange (ETDEWEB)

    Han, Soon Young; Seo, Seok Hoon; Choi, Hae Jin [Chung-Ang University, Seoul (Korea, Republic of)

    2015-11-15

    In this paper, we propose a concept selection method to evaluate future market performances of concept candidates, and to choose the best concept among those. The main and interaction effects of product performance factors, economic factors, and time on a market performance are modeled using a Bayesian framework-based Artificial neural network (ANN). The Bayesian framework is employed to measure the potential risk of wrong selection in using a trained ANN model. Based on the measured uncertainty bounds in the predicted future market performance, the most promising and robust concept may be selected. To validate our concept-selection method, we employed an automobile concept selection problem in the U.S. market. Seventeen concepts were assumed to compete in 2013, and the future market share with error bounds was predicted using the trained model based on sale data.

  10. A New Model to Facilitate Individualized Case Conceptualization and Treatment of Social Phobia: An Examination and Reaction to Moscovitch's Model

    Science.gov (United States)

    Heimberg, Richard G.

    2009-01-01

    Moscovitch's (2009) model of social phobia is put forth as an integration and extension of previous cognitive-behavioral models. The author asserts that his approach overcomes a number of shortcomings of previous models and will serve to better guide case conceptualization, treatment planning, and intervention implementation for clients with…

  11. Technology, Demographic Characteristics and E-Learning Acceptance: A Conceptual Model Based on Extended Technology Acceptance Model

    Science.gov (United States)

    Tarhini, Ali; Elyas, Tariq; Akour, Mohammad Ali; Al-Salti, Zahran

    2016-01-01

    The main aim of this paper is to develop an amalgamated conceptual model of technology acceptance that explains how individual, social, cultural and organizational factors affect the students' acceptance and usage behaviour of the Web-based learning systems. More specifically, the proposed model extends the Technology Acceptance Model (TAM) to…

  12. Structure of conceptual models in the senior operating staff of nuclear power plants

    Directory of Open Access Journals (Sweden)

    Oboznov A. A.

    2017-09-01

    Full Text Available Background. The relationships between conceptual model structures and an operator’s professional efficiency are of direct practical importance, particularly in the case of large-scale industrial complexes combining several human-machine systems. A typical example is the power unit of a nuclear power plant (NPP. Objective and methods. The purpose of this study was to explore the conceptual models of senior reactor operators (SROs of NPPs. The study involved 64 men working as SRO at five NPPs in Russia. The methods included: structured interviews, expert estimations, multidimensional scaling (ALSCAL, the K-means clustering algorithm, and frequency analysis. The procedure was as follows: 32 key characteristics of the power unit were defined, including shift operators’ jobs and duties, technical subsystems, types of equipment, and the crucial power unit parameters. The participants were offered a 32×32 matrix for pair-wise estimation of the strength of the links between these key characteristics on a seven-point scale (496 links in total. Results. A general scheme of key characteristics in the conceptual models was defined. is scheme was displayed in the operators regardless of their employment history. Within the scheme, however, two types of conceptual models were identified, which could be distinguished by the relative number of strong links between the key characteristics. With respect to intersystem links including key characteristics of the reactor and turbine NPP departments, this number was significantly higher in models of Type 1 than in those of Type 2. A positive correlation between the number of these links and the professional efficiency indicators was also established. Operators with Type 1 models were able to more predictably represent the power unit operation. Conclusion. The main role in creating predictable and efficient conceptual models was played by strong intersystem links in mental representations of workflow.

  13. Conceptual model to determine maximum activity of radioactive waste in near-surface disposal facilities

    International Nuclear Information System (INIS)

    Iarmosh, I.; Olkhovyk, Yu.

    2016-01-01

    For development of the management strategy for radioactive waste to be placed in near - surface disposal facilities (NSDF), it is necessary to justify long - term safety of such facilities. Use of mathematical modelling methods for long - term forecasts of radwaste radiation impact and assessment of radiation risks from radionuclides migration can help to resolve this issue. The purpose of the research was to develop the conceptual model for determining the maximum activity of radwaste to be safely disposed in the NSDF and to test it in the case of Lot 3 Vector NSDF (Chornobyl exclusion zone). This paper describes an approach to the development of such a model. The conceptual model of "9"0 Sr migration from Lot 3 through aeration zone and aquifer soils was developed. The results of modelling are shown. The proposals on further steps for the model improvement were developed

  14. Tracer technology modeling the flow of fluids

    CERN Document Server

    Levenspiel, Octave

    2012-01-01

    A vessel’s behavior as a heat exchanger, absorber, reactor, or other process unit is dependent upon how fluid flows through the vessel.  In early engineering, the designer would assume either plug flow or mixed flow of the fluid through the vessel.  However, these assumptions were oftentimes inaccurate, sometimes being off by a volume factor of 100 or more.  The result of this unreliable figure produced ineffective products in multiple reaction systems.   Written by a pioneering researcher in the field of chemical engineering, the tracer method was introduced to provide more accurate flow data.  First, the tracer method measured the actual flow of fluid through a vessel.  Second, it developed a suitable model to represent the flow in question.  Such models are used to follow the flow of fluid in chemical reactors and other process units, like in rivers and streams, or solid and porous structures.  In medicine, the tracer method is used to study the flow of chemicals—harmful  and harmless—in the...

  15. Hypervapotron flow testing with rapid prototype models

    International Nuclear Information System (INIS)

    Driemeyer, D.; Hellwig, T.; Kubik, D.; Langenderfer, E.; Mantz, H.; McSmith, M.; Jones, B.; Butler, J.

    1995-01-01

    A flow test model of the inlet section of a three channel hypervapotron plate that has been proposed as a heat sink in the ITER divertor was prepared using a rapid prototyping stereolithography process that is widely used for component development in US industry. An existing water flow loop at the University of Illinois is being used for isothermal flow tests to collect pressure drop data for comparison with proposed vapotron friction factor correlations. Differential pressure measurements are taken, across the test section inlet manifold, the vapotron channel (about a seven inch length), the outlet manifold and the inlet-to-outlet. The differential pressures are currently measured with manometers. Tests were conducted at flow velocities from 1--10 m/s to cover the full range of ITER interest. A tap was also added for a small hypodermic needle to inject dye into the flow channel at several positions to examine the nature of the developing flow field at the entrance to the vapotron section. Follow-on flow tests are planned using a model with adjustable flow channel dimensions to permit more extensive pressure drop data to be collected. This information will be used to update vapotron design correlations for ITER

  16. A Conceptual Model of Spirituality in Music Education

    Science.gov (United States)

    van der Merwe, Liesl; Habron, John

    2015-01-01

    This article aims to describe the phenomenon of spirituality in music education by means of a model derived from the academic literature on the topic. Given the centrality of lived experience within this literature, we adopted a hermeneutic phenomenological theoretical framework to describe the phenomenon. The NCT (noticing, collecting, and…

  17. Measuring the Impact of Communities of Practice: A Conceptual model

    NARCIS (Netherlands)

    dr. Donald Ropes

    2011-01-01

    Communities of practice (CoPs) impact different actors in different ways. Because using a singular approach would not do justice to the complexity that surrounds CoPs, a multi-disciplinary and pluralistic approach is used here to develop a model for measuring the impact CoPs may have on individuals,

  18. Iberian (South American) Model of Judicial Review: Toward Conceptual Framework

    Science.gov (United States)

    Klishas, Andrey A.

    2016-01-01

    The paper explores Latin American countries legislation with the view to identify specific features of South American model of judicial review. The research methodology rests on comparative approach to analyzing national constitutions' provisions and experts' interpretations thereof. The constitutional provisions of Brazil, Peru, Mexico, and…

  19. The Historical Evolution of Theories and Conceptual Models for Nursing.

    Science.gov (United States)

    Hawkins, Joellen W.

    The development of nursing models can be traced to the inception of nursing as a profession. Florence Nightingale laid the foundation for current nursing practice and differentiated nursing from medicine. The late 19th and early 20th centuries contributed a number of important nurse theorists, better known for other contributions to the neophyte…

  20. Public–private partnership conceptual framework and models for the ...

    African Journals Online (AJOL)

    Well-functioning and appropriately institutional investors (pension funds, insurance companies, etc.) would be natural sources of long-term financing for water services infrastructure because liabilities would better match the longer terms of water infrastructure projects. The 'hybrid model' is in the middle of the water services ...

  1. Reduced order model of draft tube flow

    International Nuclear Information System (INIS)

    Rudolf, P; Štefan, D

    2014-01-01

    Swirling flow with compact coherent structures is very good candidate for proper orthogonal decomposition (POD), i.e. for decomposition into eigenmodes, which are the cornerstones of the flow field. Present paper focuses on POD of steady flows, which correspond to different operating points of Francis turbine draft tube flow. Set of eigenmodes is built using a limited number of snapshots from computational simulations. Resulting reduced order model (ROM) describes whole operating range of the draft tube. ROM enables to interpolate in between the operating points exploiting the knowledge about significance of particular eigenmodes and thus reconstruct the velocity field in any operating point within the given range. Practical example, which employs axisymmetric simulations of the draft tube flow, illustrates accuracy of ROM in regions without vortex breakdown together with need for higher resolution of the snapshot database close to location of sudden flow changes (e.g. vortex breakdown). ROM based on POD interpolation is very suitable tool for insight into flow physics of the draft tube flows (especially energy transfers in between different operating points), for supply of data for subsequent stability analysis or as an initialization database for advanced flow simulations

  2. A picture is worth a thousand words: helping students visualize a conceptual model.

    Science.gov (United States)

    Johnson, S E

    1989-01-01

    Communicating the functional applicability of a conceptual framework to nursing students can be a challenge of considerable magnitude. Nurse educators are convinced that nursing practice and process should stem from theory. However, when attempting to teach this, many educators have struggled with the expressions of confused, skeptical students. To provide a better understanding of a nursing model, the author uses a visual representation of the Neuman Systems Model variables. The student can then visualize application of the Model to nursing practice.

  3. A conceptual model for ethical business decision-making under the influence of personal relationships

    OpenAIRE

    Davidrajuh, Reggie

    2008-01-01

    This paper proposes a conceptual model for ethical business decision-making. The purpose of this model is to explore the ethical implications of personal relationship in business exchanges. Firstly, this paper introduces personal relationship in business exchanges. Secondly, three normative theories of ethics that are relevant to the business environment are presented. Thirdly, a literature study on the existing models and frameworks for ethical business decision-making is pres...

  4. Scaled Experimental Modeling of VHTR Plenum Flows

    Energy Technology Data Exchange (ETDEWEB)

    ICONE 15

    2007-04-01

    Abstract The Very High Temperature Reactor (VHTR) is the leading candidate for the Next Generation Nuclear Power (NGNP) Project in the U.S. which has the goal of demonstrating the production of emissions free electricity and hydrogen by 2015. Various scaled heated gas and water flow facilities were investigated for modeling VHTR upper and lower plenum flows during the decay heat portion of a pressurized conduction-cooldown scenario and for modeling thermal mixing and stratification (“thermal striping”) in the lower plenum during normal operation. It was concluded, based on phenomena scaling and instrumentation and other practical considerations, that a heated water flow scale model facility is preferable to a heated gas flow facility and to unheated facilities which use fluids with ranges of density to simulate the density effect of heating. For a heated water flow lower plenum model, both the Richardson numbers and Reynolds numbers may be approximately matched for conduction-cooldown natural circulation conditions. Thermal mixing during normal operation may be simulated but at lower, but still fully turbulent, Reynolds numbers than in the prototype. Natural circulation flows in the upper plenum may also be simulated in a separate heated water flow facility that uses the same plumbing as the lower plenum model. However, Reynolds number scaling distortions will occur at matching Richardson numbers due primarily to the necessity of using a reduced number of channels connected to the plenum than in the prototype (which has approximately 11,000 core channels connected to the upper plenum) in an otherwise geometrically scaled model. Experiments conducted in either or both facilities will meet the objectives of providing benchmark data for the validation of codes proposed for NGNP designs and safety studies, as well as providing a better understanding of the complex flow phenomena in the plenums.

  5. A conceptual magnetic fabric development model for the Paks loess in Hungary

    DEFF Research Database (Denmark)

    Bradák, B.; Ujvari, Gabor; Seto, Y.

    2018-01-01

    We describe magnetic fabric and depositional environments of aeolian (loess) deposits from Paks, Hungary, and develop a novel, complex conceptual sedimentation model based on grain size and low-field magnetic susceptibility anisotropy data. A plot of shape factor (magnetic fabric parameter) and d...

  6. Purpose and Pedagogy: A Conceptual Model for an ePortfolio

    Science.gov (United States)

    Buyarski, Catherine A.; Aaron, Robert W.; Hansen, Michele J.; Hollingsworth, Cynthia D.; Johnson, Charles A.; Kahn, Susan; Landis, Cynthia M.; Pedersen, Joan S.; Powell, Amy A.

    2015-01-01

    This conceptual model emerged from the need to balance multiple purposes and perspectives associated with developing an ePortfolio designed to promote student development and success. A comprehensive review of literature from various disciplines, theoretical frameworks, and scholarship, including self-authorship, reflection, ePortfolio pedagogy,…

  7. The relationship between the key elements of Donabedian's conceptual model within the field of assistive technology

    DEFF Research Database (Denmark)

    Sund, Terje; Iwarsson, Susanne; Brandt, Åse

    2015-01-01

    Previous research has suggested that there is a relationship between the three key components of Donabedian's conceptual model for quality assessments: structure of care, process, and outcome of care. That is, structure predicted both process and outcome of care, and better processes predict better...

  8. Search for a New Conceptual Bookkeeping Model : Different Levels of Abstraction

    NARCIS (Netherlands)

    Sweere, A.M.J.; van Groenendaal, W.J.H.

    1999-01-01

    Nowadays, every bookkeeping system used in practice is automated. Most bookkeeping software and integrated information systems are based on databases. In this paper, we develop a new conceptual bookkeeping model which is not based on manual techniques, but which is applicable in a database

  9. From Conceptual Frameworks to Mental Models for Astronomy: Students' Perceptions

    Science.gov (United States)

    Pundak, David; Liberman, Ido; Shacham, Miri

    2017-01-01

    Considerable debate exists among discipline-based astronomy education researchers about how students change their perceptions in science and astronomy. The study questioned the development of astronomical models among students in institutions of higher education by examining how college students change their initial conceptual frameworks and…

  10. PIRPOSAL Model of Integrative STEM Education: Conceptual and Pedagogical Framework for Classroom Implementation

    Science.gov (United States)

    Wells, John G.

    2016-01-01

    The PIRPOSAL model is both a conceptual and pedagogical framework intended for use as a pragmatic guide to classroom implementation of Integrative STEM Education. Designerly questioning prompted by a "need to know" serves as the basis for transitioning student designers within and among multiple phases while they progress toward an…

  11. Dealing with unexpected events on the flight deck : A conceptual model of startle and surprise

    NARCIS (Netherlands)

    Landman, H.M.; Groen, E.L.; Paassen, M.M. van; Bronkhorst, A.W.; Mulder, M.

    2017-01-01

    Objective: A conceptual model is proposed in order to explain pilot performance in surprising and startling situations. Background: Today’s debate around loss of control following in-flight events and the implementation of upset prevention and recovery training has highlighted the importance of

  12. Conceptual model of management steadfast economic development production-economic systems

    OpenAIRE

    Prokhorova, V.

    2010-01-01

    The article is devoted developments of conceptual model of management proof economic development of the industrialeconomy systems. Features are certain, the algorithm of impulse is offered and intercommunication of contours of management proof economic development of the industrialeconomy systems is investigational

  13. The Interactions between Problem Solving and Conceptual Change: System Dynamic Modelling as a Platform for Learning

    Science.gov (United States)

    Lee, Chwee Beng

    2010-01-01

    This study examines the interactions between problem solving and conceptual change in an elementary science class where students build system dynamic models as a form of problem representations. Through mostly qualitative findings, we illustrate the interplay of three emerging intervening conditions (epistemological belief, structural knowledge…

  14. Pathways to Life Success: A Conceptual Model of Financial Well-Being for Young Adults

    Science.gov (United States)

    Shim, Soyeon; Xiao, Jing J.; Barber, Bonnie L.; Lyons, Angela C.

    2009-01-01

    The purpose of this study is to describe and test a conceptual model of the potential antecedents and consequences of financial well-being in young adulthood. Data (N = 781) were collected via an online survey conducted at a large state university in the southwestern United States. Our results suggest that self-actualizing personal values,…

  15. The Effect of 7E Model on Conceptual Success of Students in the Unit of Electromagnetism

    Science.gov (United States)

    Turgut, Umit; Colak, Alp; Salar, Riza

    2016-01-01

    The aim of this study was to investigate the impact of the course materials developed in accordance with 7E model in the unit of electromagnetism in high school physics class on students' conceptual success. The present study was conducted with a total of 52 11th grade students in two separate classrooms at a high school. The action research…

  16. Towards an Integrated Conceptual Model of International Student Adjustment and Adaptation

    Science.gov (United States)

    Schartner, Alina; Young, Tony Johnstone

    2016-01-01

    Despite a burgeoning body of empirical research on "the international student experience", the area remains under-theorized. The literature to date lacks a guiding conceptual model that captures the adjustment and adaptation trajectories of this unique, growing, and important sojourner group. In this paper, we therefore put forward a…

  17. On the foundation for roles in RM-ODP: contributions from conceptual modelling

    NARCIS (Netherlands)

    Guizzardi, G.; Andrade Almeida, João; Linington, P.F.; Vallecillo, A.; Wood, B.

    2007-01-01

    In this paper, we attempt to provide a semantic foundation for the role-related concepts in the RM-ODP. We believe that some theories of conceptual modelling may help us to provide a well-founded underpinning for these concepts, and to harmonize competing proposals for them. As a starting point of

  18. Testing a Conceptual Model of Working through Self-Defeating Patterns

    Science.gov (United States)

    Wei, Meifen; Ku, Tsun-Yao

    2007-01-01

    The present study developed and examined a conceptual model of working through self-defeating patterns. Participants were 390 college students at a large midwestern university. Results indicated that self-defeating patterns mediated the relations between attachment and distress. Also, self-esteem mediated the link between self-defeating patterns…

  19. A Conceptual Model for Teaching Critical Thinking in a Knowledge Economy

    Science.gov (United States)

    Chadwick, Clifton

    2011-01-01

    Critical thinking, viewed as rational and analytic thinking, is crucial for participation in a knowledge economy and society. This article provides a brief presentation of the importance of teaching critical thinking in a knowledge economy; suggests a conceptual model for teaching thinking; examines research on the historical role of teachers in…

  20. The ISO Edi Conceptual Model Activity and Its Relationship to OSI.

    Science.gov (United States)

    Fincher, Judith A.

    1990-01-01

    The edi conceptual model is being developed to define common structures, services, and processes that syntax-specific standards like X12 and EDIFACT could adopt. Open Systems Interconnection (OSI) is of interest to edi because of its potential to help enable global interoperability across Electronic Data Interchange (EDI) functional groups. A…

  1. Evaluation of Conceptual and Numerical Models for Arsenic Mobilization and Attenuation during Managed Aquifer Recharge

    NARCIS (Netherlands)

    Post, V.E.A.; Prommer, H.; Wallis, I.; Simmons, C.T.; Stuijfzand, P.J.

    2010-01-01

    Managed Aquifer Recharge (MAR) is promoted as an attractive technique to meet growing water demands. An impediment to MAR applications, where oxygenated water is recharged into anoxic aquifers, is the potential mobilization of trace metals (e.g., arsenic). While conceptual models for arsenic

  2. A Conceptual Model for Analysing Collaborative Work and Products in Groupware Systems

    Science.gov (United States)

    Duque, Rafael; Bravo, Crescencio; Ortega, Manuel

    Collaborative work using groupware systems is a dynamic process in which many tasks, in different application domains, are carried out. Currently, one of the biggest challenges in the field of CSCW (Computer-Supported Cooperative Work) research is to establish conceptual models which allow for the analysis of collaborative activities and their resulting products. In this article, we propose an ontology that conceptualizes the required elements which enable an analysis to infer a set of analysis indicators, thus evaluating both the individual and group work and the artefacts which are produced.

  3. Multiple Temperature Model for Near Continuum Flows

    International Nuclear Information System (INIS)

    XU, Kun; Liu, Hongwei; Jiang, Jianzheng

    2007-01-01

    In the near continuum flow regime, the flow may have different translational temperatures in different directions. It is well known that for increasingly rarefied flow fields, the predictions from continuum formulation, such as the Navier-Stokes equations, lose accuracy. These inaccuracies may be partially due to the single temperature assumption in the Navier-Stokes equations. Here, based on the gas-kinetic Bhatnagar-Gross-Krook (BGK) equation, a multitranslational temperature model is proposed and used in the flow calculations. In order to fix all three translational temperatures, two constraints are additionally proposed to model the energy exchange in different directions. Based on the multiple temperature assumption, the Navier-Stokes relation between the stress and strain is replaced by the temperature relaxation term, and the Navier-Stokes assumption is recovered only in the limiting case when the flow is close to the equilibrium with the same temperature in different directions. In order to validate the current model, both the Couette and Poiseuille flows are studied in the transition flow regime

  4. Conceptual design of a regional water quality screening model

    International Nuclear Information System (INIS)

    Davis, M.J.

    1981-01-01

    This water quality assessment methodology is intended to predict concentrations at future times and to estimate the impacts on water quality of energy-related activities (including industrial boilers). Estimates of impacts on water quality at future times are based on incremental changes in pollutant inputs to the body water. Important features of the model are: use of measured concentrations to account for existing conditions; consideration of incremental changes in pollutant loads; emphasis on the energy sector and industrial boilers; analysis restricted to streams only; no attempt to fully account for pollutant behavior; and flexible design, so that future improvements can be incorporated. The basic approach is very similar to the one used by Argonne's ARQUAL model but will allow more complex pollutant behavior and more flexibility in use

  5. A Conceptual Model Of E-Government Adoption in Indonesia

    OpenAIRE

    Darmawan Napitupulu

    2017-01-01

    This study aims to determine various factors are related with the process of e-Government adoption. Many researchers have traced the success factors of e-Government but are still partial. This research contributes not only in terms of technological factors but also the attitudes and behaviors of its users (personality traits) which is also influential in the process of technology adoption. In this research, will be developed an adoption model of technology in the context of e-Government. This...

  6. Flow field mapping in data rack model

    Directory of Open Access Journals (Sweden)

    Matěcha J.

    2013-04-01

    Full Text Available The main objective of this study was to map the flow field inside the data rack model, fitted with three 1U server models. The server model is based on the common four-processor 1U server. The main dimensions of the data rack model geometry are taken fully from the real geometry. Only the model was simplified with respect to the greatest possibility in the experimental measurements. The flow field mapping was carried out both experimentally and numerically. PIV (Particle Image Velocimetry method was used for the experimental flow field mapping, when the flow field has been mapped for defined regions within the 2D/3D data rack model. Ansys CFX and OpenFOAM software were used for the numerical solution. Boundary conditions for numerical model were based on data obtained from experimental measurement of velocity profile at the output of the server mockup. This velocity profile was used as the input boundary condition in the calculation. In order to achieve greater consistency of the numerical model with experimental data, the numerical model was modified with regard to the results of experimental measurements. Results from the experimental and numerical measurements were compared and the areas of disparateness were identified. In further steps the obtained proven numerical model will be utilized for the real geometry of data racks and data.

  7. Further Conceptualizing Ethnic and Racial Identity Research: The Social Identity Approach and Its Dynamic Model.

    Science.gov (United States)

    Verkuyten, Maykel

    2016-11-01

    This article proposes a further conceptualization of ethnic and racial identity (ERI) as a fundamental topic in developmental research. Adding to important recent efforts to conceptually integrate and synthesize this field, it is argued that ERI research will be enhanced by more fully considering the implications of the social identity approach. These implications include (a) the conceptualization of social identity, (b) the importance of identity motives, (c) systematic ways for theorizing and examining the critical role of situational and societal contexts, and (d) a dynamic model of the relation between ERI and context. These implications have not been fully considered in the developmental literature but offer important possibilities for moving the field forward in new directions. © 2016 The Author. Child Development © 2016 Society for Research in Child Development, Inc.

  8. Assessment of entrepreneurship pedagogy on entrepreneurship knowledge and entrepreneurial human capital asset: A conceptual model

    Directory of Open Access Journals (Sweden)

    Chidimma Odira Okeke

    2016-06-01

    Full Text Available This study is an effort to propose a conceptual model to measure the impact assessment of entrepreneurship pedagogic. It delineates entrepreneurship education pedagogic into four dimensions and opined specific level for each dimension. Reviewing the entrepreneurship education programme, assessment of entrepreneurship pedagogic evaluates the structure that influence growth mindset development through embedded heuristic strategies, thus, the impact on entrepreneurship knowledge and entrepreneurial capital asset context is proposed. Affirming Fayolle, Gailly, and Lassa-Clerc conceptual affinity that entrepreneurship education share with learning theories and entrepreneurship pedagogical content knowledge were conceptualized to suggest some practical realism guidelines of what insightful philosophy of teaching entrepreneurship need to achieve. With direct synthesis of relevant literature, propositions relating to entrepreneurship pedagogic structure along with the institutional connectedness and associated dimensions of entrepreneurship pedagogic assessment outcome were postulated. Also, the paper proposes the need for further assessment of specific forms of pedagogic impact on entrepreneurial human capital asset.

  9. Patient-reported outcomes in insomnia: development of a conceptual framework and endpoint model.

    Science.gov (United States)

    Kleinman, Leah; Buysse, Daniel J; Harding, Gale; Lichstein, Kenneth; Kalsekar, Anupama; Roth, Thomas

    2013-01-01

    This article describes qualitative research conducted with patients with clinical diagnoses of insomnia and focuses on the development of a conceptual framework and endpoint model that identifies a hierarchy and interrelationships of potential outcomes in insomnia research. Focus groups were convened to discuss how patients experience insomnia and to generate items for patient-reported questionnaires on insomnia and associated daytime consequences. Results for the focus group produced two conceptual frameworks: one for sleep and one for daytime impairment. Each conceptual framework consists of hypothesized domains and items in each domain based on patient language taken from the focus group. These item pools may ultimately serve as a basis to develop new questionnaires to assess insomnia.

  10. Lung Cancer Screening Participation: Developing a Conceptual Model to Guide Research.

    Science.gov (United States)

    Carter-Harris, Lisa; Davis, Lorie L; Rawl, Susan M

    2016-11-01

    To describe the development of a conceptual model to guide research focused on lung cancer screening participation from the perspective of the individual in the decision-making process. Based on a comprehensive review of empirical and theoretical literature, a conceptual model was developed linking key psychological variables (stigma, medical mistrust, fatalism, worry, and fear) to the health belief model and precaution adoption process model. Proposed model concepts have been examined in prior research of either lung or other cancer screening behavior. To date, a few studies have explored a limited number of variables that influence screening behavior in lung cancer specifically. Therefore, relationships among concepts in the model have been proposed and future research directions presented. This proposed model is an initial step to support theoretically based research. As lung cancer screening becomes more widely implemented, it is critical to theoretically guide research to understand variables that may be associated with lung cancer screening participation. Findings from future research guided by the proposed conceptual model can be used to refine the model and inform tailored intervention development.

  11. Conceptualizing a model: a report of the ISPOR-SMDM Modeling Good Research Practices Task Force--2.

    Science.gov (United States)

    Roberts, Mark; Russell, Louise B; Paltiel, A David; Chambers, Michael; McEwan, Phil; Krahn, Murray

    2012-01-01

    The appropriate development of a model begins with understanding the problem that is being represented. The aim of this article was to provide a series of consensus-based best practices regarding the process of model conceptualization. For the purpose of this series of articles, we consider the development of models whose purpose is to inform medical decisions and health-related resource allocation questions. We specifically divide the conceptualization process into two distinct components: the conceptualization of the problem, which converts knowledge of the health care process or decision into a representation of the problem, followed by the conceptualization of the model itself, which matches the attributes and characteristics of a particular modeling type with the needs of the problem being represented. Recommendations are made regarding the structure of the modeling team, agreement on the statement of the problem, the structure, perspective, and target population of the model, and the interventions and outcomes represented. Best practices relating to the specific characteristics of model structure and which characteristics of the problem might be most easily represented in a specific modeling method are presented. Each section contains a number of recommendations that were iterated among the authors, as well as among the wider modeling taskforce, jointly set up by the International Society for Pharmacoeconomics and Outcomes Research and the Society for Medical Decision Making. Copyright © 2012 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  12. Conceptualizing a model: a report of the ISPOR-SMDM Modeling Good Research Practices Task Force-2.

    Science.gov (United States)

    Roberts, Mark; Russell, Louise B; Paltiel, A David; Chambers, Michael; McEwan, Phil; Krahn, Murray

    2012-01-01

    The appropriate development of a model begins with understanding the problem that is being represented. The aim of this article is to provide a series of consensus-based best practices regarding the process of model conceptualization. For the purpose of this series of papers, the authors consider the development of models whose purpose is to inform medical decisions and health-related resource allocation questions. They specifically divide the conceptualization process into two distinct components: the conceptualization of the problem, which converts knowledge of the health care process or decision into a representation of the problem, followed by the conceptualization of the model itself, which matches the attributes and characteristics of a particular modeling type to the needs of the problem being represented. Recommendations are made regarding the structure of the modeling team, agreement on the statement of the problem, the structure, perspective and target population of the model, and the interventions and outcomes represented. Best practices relating to the specific characteristics of model structure, and which characteristics of the problem might be most easily represented in a specific modeling method, are presented. Each section contains a number of recommendations that were iterated among the authors, as well as the wider modeling taskforce, jointly set up by the International Society for Pharmacoeconomics and Outcomes Research and the Society for Medical Decision Making.

  13. Numerical modelling of flow pattern for high swirling flows

    Directory of Open Access Journals (Sweden)

    Parra Teresa

    2015-01-01

    Full Text Available This work focuses on the interaction of two coaxial swirling jets. High swirl burners are suitable for lean flames and produce low emissions. Computational Fluid Dynamics has been used to study the isothermal behaviour of two confined jets whose setup and operating conditions are those of the benchmark of Roback and Johnson. Numerical model is a Total Variation Diminishing and PISO is used to pressure velocity coupling. Transient analysis let identify the non-axisymmetric region of reverse flow. The center of instantaneous azimuthal velocities is not located in the axis of the chamber. The temporal sampling evidences this center spins around the axis of the device forming the precessing vortex core (PVC whose Strouhal numbers are more than two for Swirl numbers of one. Influence of swirl number evidences strong swirl numbers are precursor of large vortex breakdown. Influence of conical diffusers evidence the reduction of secondary flows associated to boundary layer separation.

  14. On conditions and parameters important to model sensitivity for unsaturated flow through layered, fractured tuff

    International Nuclear Information System (INIS)

    Prindle, R.W.; Hopkins, P.L.

    1990-10-01

    The Hydrologic Code Intercomparison Project (HYDROCOIN) was formed to evaluate hydrogeologic models and computer codes and their use in performance assessment for high-level radioactive-waste repositories. This report describes the results of a study for HYDROCOIN of model sensitivity for isothermal, unsaturated flow through layered, fractured tuffs. We investigated both the types of flow behavior that dominate the performance measures and the conditions and model parameters that control flow behavior. We also examined the effect of different conceptual models and modeling approaches on our understanding of system behavior. The analyses included single- and multiple-parameter variations about base cases in one-dimensional steady and transient flow and in two-dimensional steady flow. The flow behavior is complex even for the highly simplified and constrained system modeled here. The response of the performance measures is both nonlinear and nonmonotonic. System behavior is dominated by abrupt transitions from matrix to fracture flow and by lateral diversion of flow. The observed behaviors are strongly influenced by the imposed boundary conditions and model constraints. Applied flux plays a critical role in determining the flow type but interacts strongly with the composite-conductivity curves of individual hydrologic units and with the stratigraphy. One-dimensional modeling yields conservative estimates of distributions of groundwater travel time only under very limited conditions. This study demonstrates that it is wrong to equate the shortest possible water-travel path with the fastest path from the repository to the water table. 20 refs., 234 figs., 10 tabs

  15. INEEL Subregional Conceptual Model Report; Volume 1 - Summary of Existing Knowledge of Natural and Anthropogenic Influences Governing Subsurface Contaminant Transport in the INEEL Subregion of the Eastern Snake River Plain

    Energy Technology Data Exchange (ETDEWEB)

    Wichlacz, Paul Louis; Orr, Brennan

    2002-08-01

    The National Research Council has defined a conceptual model as ''an evolving hypothesis identifying the important features, processes, and events controlling fluid flow and contaminant transport of consequence at a specific field site in the context of a recognized problem''. Presently, several subregional conceptual models are under development at the Idaho National Engineering and Environmental Laboratory (INEEL). Additionally, facility-specific conceptual models have been described as part of INEEL environmental restoration activities. Compilation of these models is required to develop a comprehensive conceptual model that can be used to strategically plan for future groundwater research activities at the INEEL. Conceptual models of groundwater flow and contaminant transport at the INEEL include the description of the geologic framework, matrix hydraulic properties, and inflows and outflows. They also include definitions of the contaminant source term and contaminant transport mechanisms. The geologic framework of the INEEL subregion is described by the geometry of the system, stratigraphic units within the system, and structural features that affect groundwater flow and contaminant transport. These elements define geohydrologic units that make up the Snake River Plain Aquifer (SRPA). The United States Geological Survey (USGS) conceptual model encompasses approximately 1,920 mi2 of the eastern Snake River Plain. The Waste Area Group (WAG)-10 model includes the USGS area and additional areas to the northeast and southeast. Both conceptual models are bounded to the northwest by the Pioneer Mountains, Lost River Range, and Lemhi Mountains. They are bounded to the southeast by groundwater flow paths determined from aquifer water-level contours. The upgradient extent of the USGS model is a water-level contour that includes the northeastern boundary of the INEEL. The WAG-10 model includes more of the Mud Lake area to utilize previous estimates of

  16. Communication skills training: describing a new conceptual model.

    Science.gov (United States)

    Brown, Richard F; Bylund, Carma L

    2008-01-01

    Current research in communication in physician-patient consultations is multidisciplinary and multimethodological. As this research has progressed, a considerable body of evidence on the best practices in physician-patient communication has been amassed. This evidence provides a foundation for communication skills training (CST) at all levels of medical education. Although the CST literature has demonstrated that communication skills can be taught, one critique of this literature is that it is not always clear which skills are being taught and whether those skills are matched with those being assessed. The Memorial Sloan-Kettering Cancer Center Comskil Model for CST seeks to answer those critiques by explicitly defining the important components of a consultation, based on Goals, Plans, and Actions theories and sociolinguistic theory. Sequenced guidelines as a mechanism for teaching about particular communication challenges are adapted from these other methods. The authors propose that consultation communication can be guided by an overarching goal, which is achieved through the use of a set of predetermined strategies. Strategies are common in CST; however, strategies often contain embedded communication skills. These skills can exist across strategies, and the Comskil Model seeks to make them explicit in these contexts. Separate from the skills are process tasks and cognitive appraisals that need to be addressed in teaching. The authors also describe how assessment practices foster concordance between skills taught and those assessed through careful coding of trainees' communication encounters and direct feedback.

  17. Employee commitment and motivation: a conceptual analysis and integrative model.

    Science.gov (United States)

    Myer, John P; Becker, Thomas E; Vandenberghe, Christian

    2004-12-01

    Theorists and researchers interested in employee commitment and motivation have not made optimal use of each other's work. Commitment researchers seldom address the motivational processes through which commitment affects behavior, and motivation researchers have not recognized important distinctions in the forms, foci, and bases of commitment. To encourage greater cross-fertilization, the authors present an integrative framework in which commitment is presented as one of several energizing forces for motivated behavior. E. A. Locke's (1997) model of the work motivation process and J. P. Meyer and L. Herscovitch's (2001) model of workplace commitments serve as the foundation for the development of this new framework. To facilitate the merger, a new concept, goal regulation, is derived from self-determination theory (E. L. Deci & R. M. Ryan, 1985) and regulatory focus theory (E. I. Higgins, 1997). By including goal regulation, it is acknowledged that motivated behavior can be accompanied by different mindsets that have particularly important implications for the explanation and prediction of discretionary work behavior. 2004 APA, all rights reserved

  18. A conceptual model for the blooming behavior and persistence of the benthic mat-forming diatom Didymosphenia geminata in oligotrophic streams

    Science.gov (United States)

    Cullis, James D. S.; Gillis, Carole-Anne; Bothwell, Max L.; Kilroy, Cathy; Packman, Aaron; Hassan, Marwan

    2012-06-01

    The benthic, mat-forming diatomDidymosphenia geminata has the unique ability to produce large amounts of algal biomass under oligotrophic conditions in cold, fast flowing streams and rivers. This presents an ecological paradox that challenges our current understanding of stream ecosystem dynamics. Our understanding of the drivers of D. geminata ecology is still limited. Here we present a conceptual model for the blooming behavior and persistence of this species to advance scientific understanding of strategies for life in fast flowing oligotrophic waters and support the design of future research and mitigation measures for nuisance algal blooms. The conceptual model is based on a synthesis of data and ideas from a range of disciplines including hydrology, geomorphology, biogeochemistry, and ecology. The conceptual model highlights the role of water chemistry, river morphology, and flow thresholds in defining the habitat window for D. geminata. We propose that bed disturbance is a primary control on accumulation and persistence of D. geminataand that the removal threshold can be determined by synthesizing site-specific information on hydrology and geomorphology. Further, we propose that a key to understanding the didymo paradox is the separation of cellular reproduction and mat morphology with specific controls acting in respect of the different processes.

  19. The Adoption of New Technology: Conceptual Model and Application

    Directory of Open Access Journals (Sweden)

    Miriam Christi Nemoto

    2010-12-01

    Full Text Available The decision to adopt a new technology or not depends on the benefits to be gained by incorporating new technical, functional or esthetic solutions, in order to attain the company’s competitive positioning; this decision also depends on the costs and risks involved. In general terms, businesses lack the resources, whether financial, human, or structural, to innovate or even to adapt new technologies. The objectives of this study are to test an innovation adoption model on a real case and show the importance of international cooperation for new technology implementation processes, based on a decision-making case about whether or not to adopt a new technology that occurred in eletronic company in Brazil (called “A”. The new technology might help to solve certain challenges the company faced in its printer plant, by increasing efficiency and cutting costs.

  20. A conceptual model for barrier free facilities planning.

    Science.gov (United States)

    Bittencourt, R S; de M Guimarães, L B

    2012-01-01

    This paper presents the proposal of a model for planning a barrier free industrial facilities, considering the demands that inclusion requires, ranging from outside the factory (social environment), to the needs of the production system and the workstation. Along with literature review, the demands were identified in a shoe manufacturer that employs people with disabilities, and organized taxonomically in agreement with the structure for planning facilities. The results show that the problems are not primarily related to eliminating architectural barriers and factors aimed at preventing risks to people's health and safety but, rather, are related to the company's cultural environment, because the main hazards are managerial. In special cases, it is suggested there is a need to adjust those parts of tasks that the worker cannot do, or even to re-schedule work so as to make it possible for employees with disabilities to perform their tasks.

  1. CONCEPTUAL MODELLING AND ORGANIZATION OF SECURITY MECHANISMS IN DISTRIBUTED SYSTEMS

    Directory of Open Access Journals (Sweden)

    T. Galibus

    2016-01-01

    Full Text Available We analyze the existing DS from the point of security and construct a two-level hierarchy of models. Such approach allows us to separate the abstraction (architecture level and the concrete (component level of ISS. The core set of methods, i. e. authentication and key exchange protocols, corresponds to the abstraction level and is defined as security infrastructure (SI. The final security parameters optimization and additional mechanisms such as authorization, routing and data auditing of the protection mechanisms are configured on the component level of the DS. In addition, we outline the systematic step-by-step ISS configuration method.

  2. Modeling sediment concentration of rill flow

    Science.gov (United States)

    Yang, Daming; Gao, Peiling; Zhao, Yadong; Zhang, Yuhang; Liu, Xiaoyuan; Zhang, Qingwen

    2018-06-01

    Accurate estimation of sediment concentration is essential to establish physically-based erosion models. The objectives of this study were to evaluate the effects of flow discharge (Q), slope gradient (S), flow velocity (V), shear stress (τ), stream power (ω) and unit stream power (U) on sediment concentration. Laboratory experiments were conducted using a 10 × 0.1 m rill flume under four flow discharges (2, 4, 8 and 16 L min-1), and five slope gradients (5°, 10°, 15°, 20° and 25°). The results showed that the measured sediment concentration varied from 87.08 to 620.80 kg m-3 with a mean value of 343.13 kg m-3. Sediment concentration increased as a power function with flow discharge and slope gradient, with R2 = 0.975 and NSE = 0.945. The sediment concentration was more sensitive to slope gradient than to flow discharge. The sediment concentration was well predicted by unit stream power (R2 = 0.937, NSE = 0.865), whereas less satisfactorily by flow velocity (R2 = 0.470, NSE = 0.539) and stream power (R2 = 0.773, NSE = 0.732). In addition, using the equations to simulate the measured sediment concentration of other studies, the result further indicated that slope gradient, flow discharge and unit stream power were good predictors of sediment concentration. In general, slope gradient, flow discharge and unit stream power seem to be the preferred predictors for estimating sediment concentration.

  3. Multiphase flow models for hydraulic fracturing technology

    Science.gov (United States)

    Osiptsov, Andrei A.

    2017-10-01

    The technology of hydraulic fracturing of a hydrocarbon-bearing formation is based on pumping a fluid with particles into a well to create fractures in porous medium. After the end of pumping, the fractures filled with closely packed proppant particles create highly conductive channels for hydrocarbon flow from far-field reservoir to the well to surface. The design of the hydraulic fracturing treatment is carried out with a simulator. Those simulators are based on mathematical models, which need to be accurate and close to physical reality. The entire process of fracture placement and flowback/cleanup can be conventionally split into the following four stages: (i) quasi-steady state effectively single-phase suspension flow down the wellbore, (ii) particle transport in an open vertical fracture, (iii) displacement of fracturing fluid by hydrocarbons from the closed fracture filled with a random close pack of proppant particles, and, finally, (iv) highly transient gas-liquid flow in a well during cleanup. The stage (i) is relatively well described by the existing hydralics models, while the models for the other three stages of the process need revisiting and considerable improvement, which was the focus of the author’s research presented in this review paper. For stage (ii), we consider the derivation of a multi-fluid model for suspension flow in a narrow vertical hydraulic fracture at moderate Re on the scale of fracture height and length and also the migration of particles across the flow on the scale of fracture width. At the stage of fracture cleanaup (iii), a novel multi-continua model for suspension filtration is developed. To provide closure relationships for permeability of proppant packings to be used in this model, a 3D direct numerical simulation of single phase flow is carried out using the lattice-Boltzmann method. For wellbore cleanup (iv), we present a combined 1D model for highly-transient gas-liquid flow based on the combination of multi-fluid and

  4. The 2016 groundwater flow model for Dane County, Wisconsin

    Science.gov (United States)

    Parsen, Michael J.; Bradbury, Kenneth R.; Hunt, Randall J.; Feinstein, Daniel T.

    2016-01-01

    A new groundwater flow model for Dane County, Wisconsin, replaces an earlier model developed in the 1990s by the Wisconsin Geological and Natural History Survey (WGNHS) and the U.S. Geological Survey (USGS). This modeling study was conducted cooperatively by the WGNHS and the USGS with funding from the Capital Area Regional Planning Commission (CARPC). Although the overall conceptual model of the groundwater system remains largely unchanged, the incorporation of newly acquired high-quality datasets, recent research findings, and improved modeling and calibration techniques have led to the development of a more detailed and sophisticated model representation of the groundwater system. The new model is three-dimensional and transient, and conceptualizes the county’s hydrogeology as a 12-layer system including all major unlithified and bedrock hydrostratigraphic units and two high-conductivity horizontal fracture zones. Beginning from the surface down, the model represents the unlithified deposits as two distinct model layers (1 and 2). A single layer (3) simulates the Ordovician sandstone and dolomite of the Sinnipee, Ancell, and Prairie du Chien Groups. Sandstone of the Jordan Formation (layer 4) and silty dolostone of the St. Lawrence Formation (layer 5) each comprise separate model layers. The underlying glauconitic sandstone of the Tunnel City Group makes up three distinct layers: an upper aquifer (layer 6), a fracture feature (layer 7), and a lower aquifer (layer 8). The fracture layer represents a network of horizontal bedding-plane fractures that serve as a preferential pathway for groundwater flow. The model simulates the sandstone of the Wonewoc Formation as an upper aquifer (layer 9) with a bedding-plane fracture feature (layer 10) at its base. The Eau Claire aquitard (layer 11) includes shale beds within the upper portion of the Eau Claire Formation. This layer, along with overlying bedrock units, is mostly absent in the preglacially eroded valleys along

  5. Particle in the Brusselator Model with Flow

    DEFF Research Database (Denmark)

    Kuptsov, P.V.; Kuznetsov, S.P.; Mosekilde, Erik

    2002-01-01

    We consider the interaction of a small moving particle with a stationary space-periodic pattern in a chemical reaction-diffusion system with a flow. The pattern is produced by a one-dimensional Brusselator model that is perturbed by a constant displacement from the equilibrium state at the inlet....... By partially blocking the flow, the particle gives rise to a local increment of the flow rate. For certain parameter values a response with intermittent Hopf and Turing type structures is observed. In other regimes a wave of substitution of missing peaks runs across the pattern....

  6. Electromechanical Model of Blood Flow in Vessels

    OpenAIRE

    Ivo Cap; Barbora Czippelova

    2008-01-01

    The present paper deals with some theoretical derivations connected with very efficient method of solution of hydrodynamic problems of blood flow in human cardiovascular system. The electromechanical analogy of liquid flow in a tube and electromagnetic wave propagating along an electric transmission line is discussed. We have derived a detailed circuit-like model of an elementary section of the elastic tube with viscose Newtonian liquid. The analogy harmonic current electrical cir...

  7. Electromechanical Model of Blood Flow in Vessels

    Directory of Open Access Journals (Sweden)

    Ivo Cap

    2008-01-01

    Full Text Available The present paper deals with some theoretical derivations connected with very efficient method of solution of hydrodynamic problems of blood flow in human cardiovascular system. The electromechanical analogy of liquid flow in a tube and electromagnetic wave propagating along an electric transmission line is discussed. We have derived a detailed circuit-like model of an elementary section of the elastic tube with viscose Newtonian liquid. The analogy harmonic current electrical circuit has been designed

  8. A simple flow-concentration modelling method for integrating water ...

    African Journals Online (AJOL)

    A simple flow-concentration modelling method for integrating water quality and ... flow requirements are assessed for maintenance low flow, drought low flow ... the instream concentrations of chemical constituents that will arise from different ...

  9. Capacity, pressure, demand, and flow: A conceptual framework for analyzing ecosystem service provision and delivery

    Science.gov (United States)

    Villamagna, Amy M.; Angermeier, Paul L.; Bennett, Elena M.

    2013-01-01

    Ecosystem services provide an instinctive way to understand the trade-offs associated with natural resource management. However, despite their apparent usefulness, several hurdles have prevented ecosystem services from becoming deeply embedded in environmental decision-making. Ecosystem service studies vary widely in focal services, geographic extent, and in methods for defining and measuring services. Dissent among scientists on basic terminology and approaches to evaluating ecosystem services create difficulties for those trying to incorporate ecosystem services into decision-making. To facilitate clearer comparison among recent studies, we provide a synthesis of common terminology and explain a rationale and framework for distinguishing among the components of ecosystem service delivery, including: an ecosystem's capacity to produce services; ecological pressures that interfere with an ecosystem's ability to provide the service; societal demand for the service; and flow of the service to people. We discuss how interpretation and measurement of these four components can differ among provisioning, regulating, and cultural services. Our flexible framework treats service capacity, ecological pressure, demand, and flow as separate but interactive entities to improve our ability to evaluate the sustainability of service provision and to help guide management decisions. We consider ecosystem service provision to be sustainable when demand is met without decreasing capacity for future provision of that service or causing undesirable declines in other services. When ecosystem service demand exceeds ecosystem capacity to provide services, society can choose to enhance natural capacity, decrease demand and/or ecological pressure, or invest in a technological substitute. Because regulating services are frequently overlooked in environmental assessments, we provide a more detailed examination of regulating services and propose a novel method for quantifying the flow of

  10. Review and selection of unsaturated flow models

    Energy Technology Data Exchange (ETDEWEB)

    Reeves, M.; Baker, N.A.; Duguid, J.O. [INTERA, Inc., Las Vegas, NV (United States)

    1994-04-04

    Since the 1960`s, ground-water flow models have been used for analysis of water resources problems. In the 1970`s, emphasis began to shift to analysis of waste management problems. This shift in emphasis was largely brought about by site selection activities for geologic repositories for disposal of high-level radioactive wastes. Model development during the 1970`s and well into the 1980`s focused primarily on saturated ground-water flow because geologic repositories in salt, basalt, granite, shale, and tuff were envisioned to be below the water table. Selection of the unsaturated zone at Yucca Mountain, Nevada, for potential disposal of waste began to shift model development toward unsaturated flow models. Under the US Department of Energy (DOE), the Civilian Radioactive Waste Management System Management and Operating Contractor (CRWMS M&O) has the responsibility to review, evaluate, and document existing computer models; to conduct performance assessments; and to develop performance assessment models, where necessary. This document describes the CRWMS M&O approach to model review and evaluation (Chapter 2), and the requirements for unsaturated flow models which are the bases for selection from among the current models (Chapter 3). Chapter 4 identifies existing models, and their characteristics. Through a detailed examination of characteristics, Chapter 5 presents the selection of models for testing. Chapter 6 discusses the testing and verification of selected models. Chapters 7 and 8 give conclusions and make recommendations, respectively. Chapter 9 records the major references for each of the models reviewed. Appendix A, a collection of technical reviews for each model, contains a more complete list of references. Finally, Appendix B characterizes the problems used for model testing.

  11. Review and selection of unsaturated flow models

    International Nuclear Information System (INIS)

    Reeves, M.; Baker, N.A.; Duguid, J.O.

    1994-01-01

    Since the 1960's, ground-water flow models have been used for analysis of water resources problems. In the 1970's, emphasis began to shift to analysis of waste management problems. This shift in emphasis was largely brought about by site selection activities for geologic repositories for disposal of high-level radioactive wastes. Model development during the 1970's and well into the 1980's focused primarily on saturated ground-water flow because geologic repositories in salt, basalt, granite, shale, and tuff were envisioned to be below the water table. Selection of the unsaturated zone at Yucca Mountain, Nevada, for potential disposal of waste began to shift model development toward unsaturated flow models. Under the US Department of Energy (DOE), the Civilian Radioactive Waste Management System Management and Operating Contractor (CRWMS M ampersand O) has the responsibility to review, evaluate, and document existing computer models; to conduct performance assessments; and to develop performance assessment models, where necessary. This document describes the CRWMS M ampersand O approach to model review and evaluation (Chapter 2), and the requirements for unsaturated flow models which are the bases for selection from among the current models (Chapter 3). Chapter 4 identifies existing models, and their characteristics. Through a detailed examination of characteristics, Chapter 5 presents the selection of models for testing. Chapter 6 discusses the testing and verification of selected models. Chapters 7 and 8 give conclusions and make recommendations, respectively. Chapter 9 records the major references for each of the models reviewed. Appendix A, a collection of technical reviews for each model, contains a more complete list of references. Finally, Appendix B characterizes the problems used for model testing

  12. Developing two-phase flow modelling concepts for rock fractures

    Energy Technology Data Exchange (ETDEWEB)

    Keto, V. (Fortum Nuclear Services Oy, Espoo (Finland))

    2010-01-15

    The Finnish nuclear waste disposal company, Posiva Oy, is planning an underground repository for spent nuclear fuel to be constructed on the island of Olkiluoto on the south-west coast of Finland. One element of the site investigations conducted at Olkiluoto is the excavation of the underground rock characterisation facility (ONKALO) that will be extended to the final disposal depth (approximately -400 m). The bedrock around the excavated tunnel volume is fully saturated with groundwater, which water commonly contains a mixture of dissolved gases. These gases remain dissolved due to the high hydrostatic pressure. During tunnel excavation work the natural hydrostatic pressure field is disturbed and the water pressure will decrease close to the atmospheric pressure in the immediate vicinity of the tunnel. During this pressure drop two-phase flow conditions (combined flow of both water and gas) may develop in the vicinity of the underground opening, as the dissolved gas is exsoluted under the low pressure (the term exsolution refers here to release of the dissolved gas molecules from the water phase into a separate gas phase). This report steers towards concept development for numerical two-phase flow modeling for fractured rock. The focus is on the description of gas phase formation process under disturbed hydraulic conditions by exsolution of dissolved gases from groundwater, and on understanding the effects of a possibly formed gas phase on groundwater flow conditions in rock fractures. A mathematical model of three mutually coupled nonlinear partial differential equations for two-phase flow is presented and corresponding constitutional relationships are introduced and discussed. Illustrative numerical simulations are performed in a simplified setting using COMSOL Multiphysics 3.5a - software package. Shortcomings and conceptual problems are discussed. (orig.)

  13. Developing two-phase flow modelling concepts for rock fractures

    International Nuclear Information System (INIS)

    Keto, V.

    2010-01-01

    The Finnish nuclear waste disposal company, Posiva Oy, is planning an underground repository for spent nuclear fuel to be constructed on the island of Olkiluoto on the south-west coast of Finland. One element of the site investigations conducted at Olkiluoto is the excavation of the underground rock characterisation facility (ONKALO) that will be extended to the final disposal depth (approximately -400 m). The bedrock around the excavated tunnel volume is fully saturated with groundwater, which water commonly contains a mixture of dissolved gases. These gases remain dissolved due to the high hydrostatic pressure. During tunnel excavation work the natural hydrostatic pressure field is disturbed and the water pressure will decrease close to the atmospheric pressure in the immediate vicinity of the tunnel. During this pressure drop two-phase flow conditions (combined flow of both water and gas) may develop in the vicinity of the underground opening, as the dissolved gas is exsoluted under the low pressure (the term exsolution refers here to release of the dissolved gas molecules from the water phase into a separate gas phase). This report steers towards concept development for numerical two-phase flow modeling for fractured rock. The focus is on the description of gas phase formation process under disturbed hydraulic conditions by exsolution of dissolved gases from groundwater, and on understanding the effects of a possibly formed gas phase on groundwater flow conditions in rock fractures. A mathematical model of three mutually coupled nonlinear partial differential equations for two-phase flow is presented and corresponding constitutional relationships are introduced and discussed. Illustrative numerical simulations are performed in a simplified setting using COMSOL Multiphysics 3.5a - software package. Shortcomings and conceptual problems are discussed. (orig.)

  14. Managing the bank service encounter: A conceptual model

    Directory of Open Access Journals (Sweden)

    K. K. Govender

    1999-06-01

    Full Text Available In financial services marketing, especially among banks, there are a limited number of chances to impress the customer, since the services are becoming more automated. Since personal interactions with customers are becoming less numerous, customers are expecting higher quality contacts and more individual treatment. This paper proposes a service encounter management model which may impact on the customers service experience. By matching service employees with customers, the effects of certain human resources strategies may be ascertained through the customers perception of the employee service quality and the overall service quality. Opsomming Daar is 'n beperkte geleenthede om die finansiele dienste klient, veral die in banke, te beindruk, aangesien dienste al meer ge-outomatiseer raak. Seinde persoonlike kontak met kliente al minder word, verwag kliente hoer gehalte kontak en meer individuele behandeling. Hierdie artikel stel 'n bestuursmodel vir diensontmoetings voor wat 'n impak op kliente se dienservarings mag he. Deur dienswerknemers met kliente te verbind kan bepaalde menslike hulpbronstrategie-effekte vasgestel word, deur middel van kliente se persepsie van werknemer-diensgehalte en algemene diensgehalte.

  15. Unsaturated zone flow modeling for GWTT-95

    International Nuclear Information System (INIS)

    Ho, C.K.; Altman, S.J.; McKenna, S.A.; Arnold, B.W.

    1995-01-01

    In accordance with the Nuclear Regulatory Commission regulation regarding groundwater travel times at geologic repositories, various models of unsaturated flow in fractured tuff have been developed and implemented to assess groundwater travel times at the potential repository at Yucca Mountain, Nevada. Kaplan used one-dimensional models to describe the uncertainty and sensitivity of travel times to various processes at Yucca Mountain. Robey and Arnold et al. used a two-dimensional equivalent continuum model (ECM) with inter- and intra-unit heterogeneity in an attempt to assess fast-flow paths through the unsaturated, fractured tuff at Yucca Mountain (GWTT-94). However, significant flow through the fractures in previous models was not simulated due to the characteristics of the ECM, which requires the matrix to be nearly saturated before flow through the fractures is initiated. In the current study (GWTT-95), four two-dimensional cross-sections at Yucca Mountain are simulated using both the ECM and dual-permeability (DK) models. The properties of both the fracture and matrix domains are geostatistically simulated, yielding completely heterogeneous continua. Then, simulations of flow through the four cross-sections are performed using spatially nonuniform infiltration boundary conditions. Steady-state groundwater travel times from the potential repository to the water table are calculated

  16. Conceptual ecological models to guide integrated landscape monitoring of the Great Basin

    Science.gov (United States)

    Miller, D.M.; Finn, S.P.; Woodward, Andrea; Torregrosa, Alicia; Miller, M.E.; Bedford, D.R.; Brasher, A.M.

    2010-01-01

    The Great Basin Integrated Landscape Monitoring Pilot Project was developed in response to the need for a monitoring and predictive capability that addresses changes in broad landscapes and waterscapes. Human communities and needs are nested within landscapes formed by interactions among the hydrosphere, geosphere, and biosphere. Understanding the complex processes that shape landscapes and deriving ways to manage them sustainably while meeting human needs require sophisticated modeling and monitoring. This document summarizes current understanding of ecosystem structure and function for many of the ecosystems within the Great Basin using conceptual models. The conceptual ecosystem models identify key ecological components and processes, identify external drivers, develop a hierarchical set of models that address both site and landscape attributes, inform regional monitoring strategy, and identify critical gaps in our knowledge of ecosystem function. The report also illustrates an approach for temporal and spatial scaling from site-specific models to landscape models and for understanding cumulative effects. Eventually, conceptual models can provide a structure for designing monitoring programs, interpreting monitoring and other data, and assessing the accuracy of our understanding of ecosystem functions and processes.

  17. Some problems with social cognition models: a pragmatic and conceptual analysis.

    Science.gov (United States)

    Ogden, Jane

    2003-07-01

    Empirical articles published between 1997 and 2001 from 4 health psychology journals that tested or applied 1 or more social cognition models (theory of reasoned action, theory of planned behavior, health belief model, and protection motivation theory; N = 47) were scrutinized for their pragmatic and conceptual basis. In terms of their pragmatic basis, these 4 models were useful for guiding research. The analysis of their conceptual basis was less positive. First, these models do not enable the generation of hypotheses because their constructs are unspecific; they therefore cannot be tested. Second, they focus on analytic truths rather than synthetic ones, and the conclusions resulting from their application are often true by definition rather than by observation. Finally, they may create and change both cognitions and behavior rather than describe them.

  18. A Conceptual Model of Technology Transfer for Public Universities in Mexico

    Directory of Open Access Journals (Sweden)

    Hugo Necoechea

    2013-12-01

    Full Text Available Technology transfer from academic and scientific institutions has been transformed into a strategic variable for companies and nations who wish to cope with the challenges of a global economy. Since the early 1970s, many technology transfer models have tried to introduce key factors in the process. Previous studies have shown that technology transfer is influenced by various elements. This study is based on a review of two recent technology transfer models that we have used as basic concepts for developing our own conceptual model. Researcher–firm networks have been considered as key elements in the technology transfer process between public universities and firms. The conceptual model proposed could be useful to improve the efficiency of existing technology transfer mechanisms.

  19. Apparel shopping behaviour – Part 2: Conceptual theoretical model, market segments, profiles and implications

    Directory of Open Access Journals (Sweden)

    R. Du Preez

    2003-10-01

    Full Text Available This article is based on the conceptual theoretical model developed in Part 1 of this series of articles. The objective of this research is to identify female apparel consumer market segments on the basis of differentiating lifestyles, shopping orientation, cultural consciousness, store patronage and demographics. These profiles are discussed in full and the implications thereof for retailers, marketers and researchers are highlighted. A new conceptual model is proposed and recommendations are made for further research. Opsomming Hierdie artikel word gebaseer op die konseptuele teoretiese model wat reeds in Deel 1 van hierdie artikelreeks ontwikkel is. Die doel van hierdie navorsing is om marksegmente van vroue klere-kopers te identifiseer na aanleiding van hulle lewenstyle, kooporiëntasie, kulturele bewustheid, winkelvoorkeurgedrag en demografie. Hierdie profiele word volledig beskryf en die implikasies van die verskillende profiele vir kleinhandelaars, bemarkers en navorsers word uitgelig. ’n Nuwe konseptuele model word voorgestel en aanbevelings vir verdere navorsing word gemaak.

  20. A year 2003 conceptual model for the U.S. telecommunications infrastructure.

    Energy Technology Data Exchange (ETDEWEB)

    Cox, Roger Gary; Reinert, Rhonda K.

    2003-12-01

    To model the telecommunications infrastructure and its role and robustness to shocks, we must characterize the business and engineering of telecommunications systems in the year 2003 and beyond. By analogy to environmental systems modeling, we seek to develop a 'conceptual model' for telecommunications. Here, the conceptual model is a list of high-level assumptions consistent with the economic and engineering architectures of telecommunications suppliers and customers, both today and in the near future. We describe the present engineering architectures of the most popular service offerings, and describe the supplier markets in some detail. We also develop a characterization of the customer base for telecommunications services and project its likely response to disruptions in service, base-lining such conjectures against observed behaviors during 9/11.

  1. Groundwater Flow and Transport Model in Cecina Plain (Tuscany, Italy) using GIS processing

    OpenAIRE

    Riccardo Armellini; Elena Baldini; Dario Del Seppia; Fabrizio Franceschini; Natacha Gori; Stefano Menichetti; Stefano Tessitore

    2015-01-01

    This work provides a groundwater flow and transport model of trichlorethylene and tetrachlorethylene contamination in the Cecina’s coastal aquifer. The contamination analysis, with source located in the Poggio Gagliardo area (Montescudaio, Pisa), was necessary to optimize the groundwater monitoring and remediation design. The work was carried out in two phases: • design of a conceptual model of the aquifer using GIS analysis of many stratigraphic, chemical and hydrogeological data, collected ...

  2. Inferring tidal wetland stability from channel sediment fluxes: observations and a conceptual model

    Science.gov (United States)

    Ganju, Neil K.; Nidzieko, Nicholas J.; Kirwan, Matthew L.

    2013-01-01

    Anthropogenic and climatic forces have modified the geomorphology of tidal wetlands over a range of timescales. Changes in land use, sediment supply, river flow, storminess, and sea level alter the layout of tidal channels, intertidal flats, and marsh plains; these elements define wetland complexes. Diagnostically, measurements of net sediment fluxes through tidal channels are high-temporal resolution, spatially integrated quantities that indicate (1) whether a complex is stable over seasonal timescales and (2) what mechanisms are leading to that state. We estimated sediment fluxes through tidal channels draining wetland complexes on the Blackwater and Transquaking Rivers, Maryland, USA. While the Blackwater complex has experienced decades of degradation and been largely converted to open water, the Transquaking complex has persisted as an expansive, vegetated marsh. The measured net export at the Blackwater complex (1.0 kg/s or 0.56 kg/m2/yr over the landward marsh area) was caused by northwesterly winds, which exported water and sediment on the subtidal timescale; tidally forced net fluxes were weak and precluded landward transport of suspended sediment from potential seaward sources. Though wind forcing also exported sediment at the Transquaking complex, strong tidal forcing and proximity to a turbidity maximum led to an import of sediment (0.031 kg/s or 0.70 kg/m2/yr). This resulted in a spatially averaged accretion of 3.9 mm/yr, equaling the regional relative sea level rise. Our results suggest that in areas where seaward sediment supply is dominant, seaward wetlands may be more capable of withstanding sea level rise over the short term than landward wetlands. We propose a conceptual model to determine a complex's tendency toward stability or instability based on sediment source, wetland channel location, and transport mechanisms. Wetlands with a reliable portfolio of sources and transport mechanisms appear better suited to offset natural and

  3. Inferring tidal wetland stability from channel sediment fluxes: Observations and a conceptual model

    Science.gov (United States)

    Ganju, Neil K.; Nidzieko, Nicholas J.; Kirwan, Matthew L.

    2013-12-01

    and climatic forces have modified the geomorphology of tidal wetlands over a range of timescales. Changes in land use, sediment supply, river flow, storminess, and sea level alter the layout of tidal channels, intertidal flats, and marsh plains; these elements define wetland complexes. Diagnostically, measurements of net sediment fluxes through tidal channels are high-temporal resolution, spatially integrated quantities that indicate (1) whether a complex is stable over seasonal timescales and (2) what mechanisms are leading to that state. We estimated sediment fluxes through tidal channels draining wetland complexes on the Blackwater and Transquaking Rivers, Maryland, USA. While the Blackwater complex has experienced decades of degradation and been largely converted to open water, the Transquaking complex has persisted as an expansive, vegetated marsh. The measured net export at the Blackwater complex (1.0 kg/s or 0.56 kg/m2/yr over the landward marsh area) was caused by northwesterly winds, which exported water and sediment on the subtidal timescale; tidally forced net fluxes were weak and precluded landward transport of suspended sediment from potential seaward sources. Though wind forcing also exported sediment at the Transquaking complex, strong tidal forcing and proximity to a turbidity maximum led to an import of sediment (0.031 kg/s or 0.70 kg/m2/yr). This resulted in a spatially averaged accretion of 3.9 mm/yr, equaling the regional relative sea level rise. Our results suggest that in areas where seaward sediment supply is dominant, seaward wetlands may be more capable of withstanding sea level rise over the short term than landward wetlands. We propose a conceptual model to determine a complex's tendency toward stability or instability based on sediment source, wetland channel location, and transport mechanisms. Wetlands with a reliable portfolio of sources and transport mechanisms appear better suited to offset natural and anthropogenic loss.

  4. Conceptualization of Approaches and Thought Processes Emerging in Validating of Model in Mathematical Modeling in Technology Aided Environment

    Science.gov (United States)

    Hidiroglu, Çaglar Naci; Bukova Güzel, Esra

    2013-01-01

    The aim of the present study is to conceptualize the approaches displayed for validation of model and thought processes provided in mathematical modeling process performed in technology-aided learning environment. The participants of this grounded theory study were nineteen secondary school mathematics student teachers. The data gathered from the…

  5. MAPIT: A new software tool to assist in the transition from conceptual model to numerical simulation models

    International Nuclear Information System (INIS)

    Canales, T.W.; Grant, C.W.

    1996-01-01

    MapIt is a new software tool developed at Lawrence Livermore National Laboratory to assist ground water remediation professionals in generating numerical simulation models from a variety of physical and chemical data sources and the corresponding 1, 2, and 3 dimensional conceptual models that emerge from analysis of such data

  6. A Conceptual Model for Increasing Use of Electronic Medical Records by Primary Care Physicians Through End-User Support.

    Science.gov (United States)

    Randhawa, Gurprit K

    2017-01-01

    A conceptual model for exploring the relationship between end-user support (EUS) and electronic medical record (EMR) use by primary care physicians is presented. The model was developed following a review of conceptual and theoretical frameworks related to technology adoption/use and EUS. The model includes (a) one core construct (facilitating conditions), (b) four antecedents and one postcedent of facilitating conditions, and (c) four moderators. EMR use behaviour is the key outcome of the model. The proposed conceptual model should be tested. The model may be used to inform planning and decision-making for EMR implementations to increase EMR use for benefits realization.

  7. Facilitating Corporate Entrepreneurship in Public Sector Higher Education Institutions: A Conceptual Model

    Directory of Open Access Journals (Sweden)

    Javed Nayyar Malik

    2012-06-01

    Full Text Available This paper develops a conceptual model of public sector corporate entrepreneurship for the state government higher education institutions. The proposed model is intended to depict the main antecedents that relate to corporate entrepreneurship within the public sector higher education institution  and the impact of corporate entrepreneurship on public sector HEI’s performance, as well as factors influencing its continuous performance.

  8. Conceptual model for concessioning in the Water Supply and Sanitation sector in Bulgaria

    OpenAIRE

    Todor Raychev

    2018-01-01

    The purpose of this article is to create a new conceptual model for sustainable development of the water sector in Bulgaria on the basis of concessions by statistical regions according to the NUTS-2 classification of the European Union. The essence of the proposed model includes an approach for consolidating the existing 66 WSS operators in three WSS operators – concessionaires. The approach is applied to provide WSS services for drinking and household needs of the population. WSS services fo...

  9. Pesticide fate on catchment scale: conceptual modelling of stream CSIA data

    Science.gov (United States)

    Lutz, Stefanie R.; van der Velde, Ype; Elsayed, Omniea F.; Imfeld, Gwenaël; Lefrancq, Marie; Payraudeau, Sylvain; van Breukelen, Boris M.

    2017-10-01

    Compound-specific stable isotope analysis (CSIA) has proven beneficial in the characterization of contaminant degradation in groundwater, but it has never been used to assess pesticide transformation on catchment scale. This study presents concentration and carbon CSIA data of the herbicides S-metolachlor and acetochlor from three locations (plot, drain, and catchment outlets) in a 47 ha agricultural catchment (Bas-Rhin, France). Herbicide concentrations at the catchment outlet were highest (62 µg L-1) in response to an intense rainfall event following herbicide application. Increasing δ13C values of S-metolachlor and acetochlor by more than 2 ‰ during the study period indicated herbicide degradation. To assist the interpretation of these data, discharge, concentrations, and δ13C values of S-metolachlor were modelled with a conceptual mathematical model using the transport formulation by travel-time distributions. Testing of different model setups supported the assumption that degradation half-lives (DT50) increase with increasing soil depth, which can be straightforwardly implemented in conceptual models using travel-time distributions. Moreover, model calibration yielded an estimate of a field-integrated isotopic enrichment factor as opposed to laboratory-based assessments of enrichment factors in closed systems. Thirdly, the Rayleigh equation commonly applied in groundwater studies was tested by our model for its potential to quantify degradation on catchment scale. It provided conservative estimates on the extent of degradation as occurred in stream samples. However, largely exceeding the simulated degradation within the entire catchment, these estimates were not representative of overall degradation on catchment scale. The conceptual modelling approach thus enabled us to upscale sample-based CSIA information on degradation to the catchment scale. Overall, this study demonstrates the benefit of combining monitoring and conceptual modelling of concentration

  10. Therapists' Perspectives on Suicide: A Conceptual Model of Connectedness.

    Science.gov (United States)

    Aherne, Cian; Coughlan, Barry; Surgenor, Paul

    2017-08-03

    A sense of disconnection for people who are suicidal seems to be a key construct of previous literature. Therapists' ways of encountering and understanding people who are suicidal have not been previously researched in depth using qualitative methodologies. The current study aims to develop a theoretical framework for the role played by connectedness in relation to suicide based on the perspectives of psychotherapists working in the field of suicide intervention. Psychotherapists (N = 12) from a suicide intervention service in Ireland were interviewed in relation to connectedness and suicide. The interviews were analysed using Constructivist Grounded Theory. A tentative theoretical model for connectedness in relation to suicide was developed. Therapists view self-disconnect as at the core of suicidality and note that toxic relationships also play a critical role. Therapeutic connection can present as a life-saving paradox for people who are suicidal. Risk of death and therapeutic endeavour may present as challenging dynamics for working with people who are suicidal. Some discussion points include the worth of self-compassion development for people who are suicidal, the rephrasing of "psychotherapy" when trying to save someone's life and the emphasis on relationship skills for all healthcare professionals who encounter people who are suicidal. Clinical or methodological significance of this article: This article is one of the first in which therapists are interviewed about their understandings of suicide and the processes of suicide in the therapeutic space. It offers novel insights about how people who are suicidal present in therapy and what may be contributing to this presentation. The research also gives insights on the struggles for therapists working with people who are suicidal and who may be ambiguous about the prospect of therapy and connecting. The study also offers important direction for future studies in relation to what requires further discussion

  11. What Can Be Learned From a Laboratory Model of Conceptual Change? Descriptive Findings and Methodological Issues

    Science.gov (United States)

    Ohlsson, Stellan; Cosejo, David G.

    2014-07-01

    The problem of how people process novel and unexpected information— deep learning (Ohlsson in Deep learning: how the mind overrides experience. Cambridge University Press, New York, 2011)—is central to several fields of research, including creativity, belief revision, and conceptual change. Researchers have not converged on a single theory for conceptual change, nor has any one theory been decisively falsified. One contributing reason is the difficulty of collecting informative data in this field. We propose that the commonly used methodologies of historical analysis, classroom interventions, and developmental studies, although indispensible, can be supplemented with studies of laboratory models of conceptual change. We introduce re- categorization, an experimental paradigm in which learners transition from one definition of a categorical concept to another, incompatible definition of the same concept, a simple form of conceptual change. We describe a re-categorization experiment, report some descriptive findings pertaining to the effects of category complexity, the temporal unfolding of learning, and the nature of the learner's final knowledge state. We end with a brief discussion of ways in which the re-categorization model can be improved.

  12. A Conceptual Model of Future Volcanism at Medicine Lake Volcano, California - With an Emphasis on Understanding Local Volcanic Hazards

    Science.gov (United States)

    Molisee, D. D.; Germa, A.; Charbonnier, S. J.; Connor, C.

    2017-12-01

    Medicine Lake Volcano (MLV) is most voluminous of all the Cascade Volcanoes ( 600 km3), and has the highest eruption frequency after Mount St. Helens. Detailed mapping by USGS colleagues has shown that during the last 500,000 years MLV erupted >200 lava flows ranging from basalt to rhyolite, produced at least one ash-flow tuff, one caldera forming event, and at least 17 scoria cones. Underlying these units are 23 additional volcanic units that are considered to be pre-MLV in age. Despite the very high likelihood of future eruptions, fewer than 60 of 250 mapped volcanic units (MLV and pre-MLV) have been dated reliably. A robust set of eruptive ages is key to understanding the history of the MLV system and to forecasting the future behavior of the volcano. The goals of this study are to 1) obtain additional radiometric ages from stratigraphically strategic units; 2) recalculate recurrence rate of eruptions based on an augmented set of radiometric dates; and 3) use lava flow, PDC, ash fall-out, and lahar computational simulation models to assess the potential effects of discrete volcanic hazards locally and regionally. We identify undated target units (units in key stratigraphic positions to provide maximum chronological insight) and obtain field samples for radiometric dating (40Ar/39Ar and K/Ar) and petrology. Stratigraphic and radiometric data are then used together in the Volcano Event Age Model (VEAM) to identify changes in the rate and type of volcanic eruptions through time, with statistical uncertainty. These newly obtained datasets will be added to published data to build a conceptual model of volcanic hazards at MLV. Alternative conceptual models, for example, may be that the rate of MLV lava flow eruptions are nonstationary in time and/or space and/or volume. We explore the consequences of these alternative models on forecasting future eruptions. As different styles of activity have different impacts, we estimate these potential effects using simulation

  13. A subchannel based annular flow dryout model

    International Nuclear Information System (INIS)

    Hammouda, Najmeddine; Cheng, Zhong; Rao, Yanfei F.

    2016-01-01

    Highlights: • A modified annular flow dryout model for subchannel thermalhydraulic analysis. • Implementation of the model in Canadian subchannel code ASSERT-PV. • Assessment of the model against tube CHF experiments. • Assessment of the model against CANDU-bundle CHF experiments. - Abstract: This paper assesses a popular tube-based mechanistic critical heat flux model (Hewitt and Govan’s annular flow model (based on the model of Whalley et al.), and modifies and implements the model for bundle geometries. It describes the results of the ASSERT subchannel code predictions using the modified model, as applied to a single tube and the 28-element, 37-element and 43-element (CANFLEX) CANDU bundles. A quantitative comparison between the model predictions and experimental data indicates good agreement for a wide range of flow conditions. The comparison has resulted in an overall average error of −0.15% and an overall root-mean-square error of 5.46% with tube data representing annular film dryout type critical heat flux, and in an overall average error of −0.9% and an overall RMS error of 9.9% with Stern Laboratories’ CANDU-bundle data.

  14. On renormalization group flow in matrix model

    International Nuclear Information System (INIS)

    Gao, H.B.

    1992-10-01

    The renormalization group flow recently found by Brezin and Zinn-Justin by integrating out redundant entries of the (N+1)x(N+1) Hermitian random matrix is studied. By introducing explicitly the RG flow parameter, and adding suitable counter terms to the matrix potential of the one matrix model, we deduce some interesting properties of the RG trajectories. In particular, the string equation for the general massive model interpolating between the UV and IR fixed points turns out to be a consequence of RG flow. An ambiguity in the UV region of the RG trajectory is remarked to be related to the large order behaviour of the one matrix model. (author). 7 refs

  15. Multiphase reacting flows modelling and simulation

    CERN Document Server

    Marchisio, Daniele L

    2007-01-01

    The papers in this book describe the most widely applicable modeling approaches and are organized in six groups covering from fundamentals to relevant applications. In the first part, some fundamentals of multiphase turbulent reacting flows are covered. In particular the introduction focuses on basic notions of turbulence theory in single-phase and multi-phase systems as well as on the interaction between turbulence and chemistry. In the second part, models for the physical and chemical processes involved are discussed. Among other things, particular emphasis is given to turbulence modeling strategies for multiphase flows based on the kinetic theory for granular flows. Next, the different numerical methods based on Lagrangian and/or Eulerian schemes are presented. In particular the most popular numerical approaches of computational fluid dynamics codes are described (i.e., Direct Numerical Simulation, Large Eddy Simulation, and Reynolds-Averaged Navier-Stokes approach). The book will cover particle-based meth...

  16. A void distribution model-flashing flow

    International Nuclear Information System (INIS)

    Riznic, J.; Ishii, M.; Afgan, N.

    1987-01-01

    A new model for flashing flow based on wall nucleations is proposed here and the model predictions are compared with some experimental data. In order to calculate the bubble number density, the bubble number transport equation with a distributed source from the wall nucleation sites was used. Thus it was possible to avoid the usual assumption of a constant bubble number density. Comparisons of the model with the data shows that the model based on the nucleation site density correlation appears to be acceptable to describe the vapor generation in the flashing flow. For the limited data examined, the comparisons show rather satisfactory agreement without using a floating parameter to adjust the model. This result indicated that, at least for the experimental conditions considered here, the mechanistic predictions of the flashing phenomenon is possible on the present wall nucleation based model

  17. The EBM-DPSER conceptual model: integrating ecosystem services into the DPSIR framework.

    Directory of Open Access Journals (Sweden)

    Christopher R Kelble

    Full Text Available There is a pressing need to integrate biophysical and human dimensions science to better inform holistic ecosystem management supporting the transition from single species or single-sector management to multi-sector ecosystem-based management. Ecosystem-based management should focus upon ecosystem services, since they reflect societal goals, values, desires, and benefits. The inclusion of ecosystem services into holistic management strategies improves management by better capturing the diversity of positive and negative human-natural interactions and making explicit the benefits to society. To facilitate this inclusion, we propose a conceptual model that merges the broadly applied Driver, Pressure, State, Impact, and Response (DPSIR conceptual model with ecosystem services yielding a Driver, Pressure, State, Ecosystem service, and Response (EBM-DPSER conceptual model. The impact module in traditional DPSIR models focuses attention upon negative anthropomorphic impacts on the ecosystem; by replacing impacts with ecosystem services the EBM-DPSER model incorporates not only negative, but also positive changes in the ecosystem. Responses occur as a result of changes in ecosystem services and include inter alia management actions directed at proactively altering human population or individual behavior and infrastructure to meet societal goals. The EBM-DPSER conceptual model was applied to the Florida Keys and Dry Tortugas marine ecosystem as a case study to illustrate how it can inform management decisions. This case study captures our system-level understanding and results in a more holistic representation of ecosystem and human society interactions, thus improving our ability to identify trade-offs. The EBM-DPSER model should be a useful operational tool for implementing EBM, in that it fully integrates our knowledge of all ecosystem components while focusing management attention upon those aspects of the ecosystem most important to human society

  18. The EBM-DPSER Conceptual Model: Integrating Ecosystem Services into the DPSIR Framework

    Science.gov (United States)

    Kelble, Christopher R.; Loomis, Dave K.; Lovelace, Susan; Nuttle, William K.; Ortner, Peter B.; Fletcher, Pamela; Cook, Geoffrey S.; Lorenz, Jerry J.; Boyer, Joseph N.

    2013-01-01

    There is a pressing need to integrate biophysical and human dimensions science to better inform holistic ecosystem management supporting the transition from single species or single-sector management to multi-sector ecosystem-based management. Ecosystem-based management should focus upon ecosystem services, since they reflect societal goals, values, desires, and benefits. The inclusion of ecosystem services into holistic management strategies improves management by better capturing the diversity of positive and negative human-natural interactions and making explicit the benefits to society. To facilitate this inclusion, we propose a conceptual model that merges the broadly applied Driver, Pressure, State, Impact, and Response (DPSIR) conceptual model with ecosystem services yielding a Driver, Pressure, State, Ecosystem service, and Response (EBM-DPSER) conceptual model. The impact module in traditional DPSIR models focuses attention upon negative anthropomorphic impacts on the ecosystem; by replacing impacts with ecosystem services the EBM-DPSER model incorporates not only negative, but also positive changes in the ecosystem. Responses occur as a result of changes in ecosystem services and include inter alia management actions directed at proactively altering human population or individual behavior and infrastructure to meet societal goals. The EBM-DPSER conceptual model was applied to the Florida Keys and Dry Tortugas marine ecosystem as a case study to illustrate how it can inform management decisions. This case study captures our system-level understanding and results in a more holistic representation of ecosystem and human society interactions, thus improving our ability to identify trade-offs. The EBM-DPSER model should be a useful operational tool for implementing EBM, in that it fully integrates our knowledge of all ecosystem components while focusing management attention upon those aspects of the ecosystem most important to human society and does so within

  19. Geological investigations contributing to the hydrogeological conceptual model in the Meuse/Haute-Marne area, Eastern France

    International Nuclear Information System (INIS)

    Rocher, M.; De Hoyos, A.; Hibsch, C.; Viennot, P.

    2010-01-01

    Callovian-Oxfordian (COX) indurated clay formation is currently studied by Andra in the 'Meuse/Haute-Marne' (MHM) area for hosting a potential repository of high level, long-lived radioactive waste. IRSN is conducting studies in support of the safety evaluation of the geological disposal programme developed by Andra. IRSN, in collaboration with the Paris School of Mines, develops conceptual and numerical models of the underground water flows throughout the Paris sedimentary basin. The calibrated numerical model correctly represents the hydraulic heads and water salinities collected throughout the basin. At the MHM scale however, several flow patterns can still reproduce the measured heads, some of them assuming specific flow pathways along regional tectonic trends. Considering or not such tectonic trends in the model has however an impact on the estimated radionuclide transfer times to the outlets. Even though most ANDRA and IRSN geochemical analyses suggest a dominant diffusive transport across the COX between the underlying Dogger and overlying Oxfordian aquifers, few data point out the possible existence of local vertical connections across major tectonic structures. In order to select the most plausible options for the numerical modelling, IRSN compiled published studies and carried out fieldwork analysis to provide new data for its hydrogeological conceptual model. Relevant geological data can be considered both at the kilometre scale and at the metre scale. At the kilometre scale, the litho-stratigraphic scheme both for Dogger and Oxfordian series had previously been documented in the MHM area. Regional sedimentologic and diagenetic models are available for the Oxfordian aquifer and partially for the Dogger aquifer. Our fieldwork analysis complete these models thanks to new correlations pointed out during detailed iso-hyps mapping performed by G2R laboratory, southeast from the MHM area. Unlike the Kimmeridgian and COX sedimentary piles, which are

  20. Non-Volcanic release of CO2 in Italy: quantification, conceptual models and gas hazard

    Science.gov (United States)

    Chiodini, G.; Cardellini, C.; Caliro, S.; Avino, R.

    2011-12-01

    Central and South Italy are characterized by the presence of many reservoirs naturally recharged by CO2 of deep provenance. In the western sector, the reservoirs feed hundreds of gas emissions at the surface. Many studies in the last years were devoted to (i) elaborating a map of CO2 Earth degassing of the region; (ii) to asses the gas hazard; (iii) to develop methods suitable for the measurement of the gas fluxes from different types of emissions; (iv) to elaborate the conceptual model of Earth degassing and its relation with the seismic activity of the region and (v) to develop physical numerical models of CO2 air dispersion. The main results obtained are: 1) A general, regional map of CO2 Earth degassing in Central Italy has been elaborated. The total flux of CO2 in the area has been estimated in ~ 10 Mt/a which are released to the atmosphere trough numerous dangerous gas emissions or by degassing spring waters (~ 10 % of the CO2 globally estimated to be released by the Earth trough volcanic activity). 2) An on line, open access, georeferenced database of the main CO2 emissions (~ 250) was settled up (http://googas.ov.ingv.it). CO2 flux > 100 t/d characterise 14% of the degassing sites while CO2 fluxes from 100 t/d to 10 t/d have been estimated for about 35% of the gas emissions. 3) The sites of the gas emissions are not suitable for life: the gas causes many accidents to animals and people. In order to mitigate the gas hazard a specific model of CO2 air dispersion has been developed and applied to the main degassing sites. A relevant application regarded Mefite d'Ansanto, southern Apennines, which is the largest natural emission of low temperature CO2 rich gases, from non-volcanic environment, ever measured in the Earth (˜2000 t/d). Under low wind conditions, the gas flows along a narrow natural channel producing a persistent gas river which has killed over a period of time many people and animals. The application of the physical numerical model allowed us to